| |  | | | | | We just completed performing emergency maintenance on Feed My Inbox. All emails were delayed during this time. We appreciate your patience and are so sorry for any inconvenience this may have caused. | | | | | | | | | | | | |  | |  | | | | | TERMSC | | | | | | | | | | | | | | | | | | | Persistent high glucose concentrations alter the regenerative potential of mesenchymal stem cells. Stem Cells Dev. 2010 Dec;19(12):1875-84 Authors: Cramer C, Freisinger E, Jones RK, Slakey DP, Dupin CL, Newsome ER, Alt EU, Izadpanah R Type 2 diabetes is associated with numerous long-term complications. This study aims to investigate whether impaired function of tissue-resident multipotent cells play role in pathogenesis of allied complications. Adipose-tissue-derived mesenchymal stem cells (ASCs) derived from nondiabetic (nASCs) and diabetic (dASCs) donors were compared with regard to glucose metabolism, cell replication, apoptosis, and differentiation potential. The data evidenced that elevation of glucose reduces proliferative capacity of both dASCs and nASCs, but impacts dASCs more significantly. Incorporation of insulin enhanced cell replication especially in nASCs. dASCs show higher levels of cellular senescence and apoptosis than nASCs. Unlike nASCs, apoptosis is induced via intrinsic pathway in dASCs. Data also evidenced that high glucose concentrations cause prominent disparities in nASCs and dASCs in expression of genes involved in insulin resistance such as adiponectin and resistin. Some changes in gene expression were irreversible in dASCs when treated with insulin. Additionally, high glucose concentrations reduce osteogenic and chondrogenic potential of ASCs, but enhance adipogenic potential. These results indicate that in addition to involvement in insulin resistance, impaired function of mesenchymal stem cells that reside in adipose tissue as one of the major sources of adult stem cells might be responsible for complications related to diabetes type 2. PMID: 20380516 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | A multiscale mechanobiological modelling framework using agent-based models and finite element analysis: application to vascular tissue engineering. Biomech Model Mechanobiol. 2011 May 31; Authors: Zahedmanesh H, Lally C Computational models of mechanobiological systems have been widely used to provide insight into these systems and also to predict their behaviour. In this context, vascular tissue engineering benefits from further attention given the challenges involved in developing functional low calibre vascular grafts with long-term patency. In this study, a novel multiscale mechanobiological modelling framework is presented, which takes advantage of lattice-free agent-based models coupled with the finite element method to investigate the dynamics of VSMC growth in vascular tissue engineering scaffolds. The results illustrate the ability of the mechanobiological modelling approach to capture complex multiscale mechanobiological phenomena. Specifically, the framework enabled the study of the influence of scaffold compliance and loading regime in regulating the growth of VSMCs in vascular scaffolds and their role in development of intimal hyperplasia (IH). The model demonstrates that low scaffold compliance compared to host arteries leads to increased luminal ingrowth and IH development. In addition, culture of a tissue-engineered blood vessel under a pulsatile luminal pressure reduced luminal ingrowth and enhanced collagen synthesis within the scaffold compared to non-pulsatile culture. The mechanobiological framework presented provides a robust platform for testing hypotheses in vascular tissue engineering and lends itself to use as an optimisation design tool. PMID: 21626394 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Expanded polytetrafluoroethylene as a substrate for retinal pigment epithelial cell growth and transplantation in age-related macular degeneration. Br J Ophthalmol. 2011 Apr;95(4):569-73 Authors: Krishna Y, Sheridan C, Kent D, Kearns V, Grierson I, Williams R Retinal pigment epithelial (RPE) transplantation presents a potential treatment for age-related macular degeneration (AMD). A suitable transplant membrane that can support an intact functioning RPE monolayer is required. Expanded polytetrafluoroethylene (ePTFE) possesses the physical properties required for a transplanting device; however, cells do not attach and spread on ePTFE. This study investigated the ability of surface-modified ePTFE to optimise the growth and function of healthy RPE monolayers. PMID: 21317216 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Unravelling the twists and turns of the serpinopathies. FEBS J. 2011 May 30; Authors: Roussel BD, Irving JA, Ekeowa UI, Belorgey D, Haq I, Ordóñez A, Kruppa AJ, Duvoix A, Tamir Rashid S, Crowther DC, Marciniak SJ, Lomas DA Members of the serine protease inhibitor, or serpin, superfamily are found in all branches of life and play an important role in the regulation of enzymes involved in proteolytic cascades. Mutants of the serpins result in a delay in folding, with unstable intermediates being cleared by endoplasmic reticulum associated degradation (ERAD). The remaining protein is either fully folded and secreted or retained as ordered polymers within the endoplasmic reticulum of the cell of synthesis. This results in a group of diseases termed the serpinopathies that is typified by mutations of α(1) -antitrypsin and neuroserpin in association with cirrhosis and the dementia FENIB, respectively. Current evidence strongly suggests that polymers of mutants of α(1) -antitrypsin and neuroserpin are linked by the sequential insertion of the reactive loop of one molecule into β-sheet A of another. The ordered structure of the polymers within the endoplasmic reticulum stimulates NF-KB by a pathway that is independent of the unfolded protein response. This chronic activation of NF-KB may contribute to the cell toxicity associated with mutations of the serpins. We review here the pathobiology of the serpinopathies and the development of novel therapeutic strategies to treat the inclusions that cause disease. These include the use of small molecules to block polymerisation, stimulation of autophagy to clear inclusions and stem cell technology to correct the underlying molecular defect. PMID: 21624056 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Self-organizing optic-cup morphogenesis in three-dimensional culture. Nature. 2011 Apr 7;472(7341):51-6 Authors: Eiraku M, Takata N, Ishibashi H, Kawada M, Sakakura E, Okuda S, Sekiguchi K, Adachi T, Sasai Y Balanced organogenesis requires the orchestration of multiple cellular interactions to create the collective cell behaviours that progressively shape developing tissues. It is currently unclear how individual, localized parts are able to coordinate with each other to develop a whole organ shape. Here we report the dynamic, autonomous formation of the optic cup (retinal primordium) structure from a three-dimensional culture of mouse embryonic stem cell aggregates. Embryonic-stem-cell-derived retinal epithelium spontaneously formed hemispherical epithelial vesicles that became patterned along their proximal-distal axis. Whereas the proximal portion differentiated into mechanically rigid pigment epithelium, the flexible distal portion progressively folded inward to form a shape reminiscent of the embryonic optic cup, exhibited interkinetic nuclear migration and generated stratified neural retinal tissue, as seen in vivo. We demonstrate that optic-cup morphogenesis in this simple cell culture depends on an intrinsic self-organizing program involving stepwise and domain-specific regulation of local epithelial properties. PMID: 21475194 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Comparison of bacterial adhesion and cellular proliferation on newly developed three-dimensional scaffolds manufactured by rapid prototyping technology. J Biomed Mater Res A. 2011 May 27; Authors: Al-Ahmad A, Schubert C, Carvalho C, Thoman Y, Wittmer A, Metzger M, Hellwig E, Swieszkowski W, Wiedmann-Al-Ahmad M Scaffolds used in the field of tissue engineering should facilitate the adherence, spreading, and ingrowth of cells as well as prevent microbial adherence. For the first time, this study simultaneously deals with microbial and tissue cell adhesion to rapid prototyping-produced 3D-scaffolds. The cell growth of human osteosarcoma cells (CAL-72) over a time period of 3-11 days were examined on three scaffolds (PLGA, PLLA, PLLA-TCP) and compared to the adhesion of salivary microorganisms and representative germs of the oral flora (Porphyromonas gingivalis, Prevotella nigrescens, Candida albicans, Enterococcus faecalis, Streptococcus mutans, and Streptococcus sanguinis). Scanning electron microscopy (SEM), cell proliferation measurements, and determination of the colony forming units (CFU) were performed. The cell proliferation rates on PLLA and PLLA-TCP after 3, 7, and 11 days of cultivation were higher than on PLGA. On day 3 the proliferation rates on PLLA and PLLA-TCP, and on day 5 on PLLA-TCP, proved to be significantly higher compared to that of the control (culture plate). The strain which showed the most CFUs on all of the investigated scaffolds was P. gingivalis, followed by E. faecalis. No significant CFU differences were determined examining P. gingivalis among the biomaterials. In contrast, E. faecalis was significantly more adherent to PLGA and PLLA compared to PLLA-TCP. The lowest CFU values were seen with C. albicans and P. nigrescens. Salivary born aerobic and anaerobic microorganisms adhered significantly more to PLGA compared to PLLA-TCP. These results supported by SEM point out the high potential of PLLA-TCP in the field of tissue engineering. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 2011. PMID: 21626662 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Tendon tissue engineering: Progress, challenges, and translation to the clinic. J Musculoskelet Neuronal Interact. 2011 Jun;11(2):163-73 Authors: Shearn JT, Kinneberg KR, Dyment NA, Galloway MT, Kenter K, Wylie C, Butler DL The tissue engineering field has made great strides in understanding how different aspects of tissue engineered constructs (TECs) and the culture process affect final tendon repair. However, there remain significant challenges in developing strategies that will lead to a clinically effective and commercially successful product. In an effort to increase repair quality, a better understanding of normal development, and how it differs from adult tendon healing, may provide strategies to improve tissue engineering. As tendon tissue engineering continues to improve, the field needs to employ more clinically relevant models of tendon injury such as degenerative tendons. We need to translate successes to larger animal models to begin exploring the clinical implications of our treatments. By advancing the models used to validate our TECs, we can help convince our toughest customer, the surgeon, that our products will be clinically efficacious. As we address these challenges in musculoskeletal tissue engineering, the field still needs to address the commercialization of products developed in the laboratory. TEC commercialization faces numerous challenges because each injury and patient is unique. This review aims to provide tissue engineers with a summary of important issues related to engineering tendon repairs and potential strategies for producing clinically successful products. PMID: 21625053 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Significance of Thymosin β4 and Implication of PINCH-1-ILK-α-Parvin (PIP) Complex in Human Dilated Cardiomyopathy. PLoS One. 2011;6(5):e20184 Authors: Sopko N, Qin Y, Finan A, Dadabayev A, Chigurupati S, Qin J, Penn MS, Gupta S Myocardial remodeling is a major contributor in the development of heart failure (HF) after myocardial infarction (MI). Integrin-linked kinase (ILK), LIM-only adaptor PINCH-1, and α-parvin are essential components of focal adhesions (FAs), which are highly expressed in the heart. ILK binds tightly to PINCH-1 and α-parvin, which regulates FA assembly and promotes cell survival via the activation of the kinase Akt. Mice lacking ILK, PINCH or α-parvin have been shown to develop severe defects in the heart, suggesting that these proteins play a critical role in heart function. Utilizing failing human heart tissues (dilated cardiomyopathy, DCM), we found a 2.27-fold (p<0.001) enhanced expression of PINCH, 4 fold for α-parvin, and 10.5 fold (p<0.001) for ILK as compared to non-failing (NF) counterparts. No significant enhancements were found for the PINCH isoform PINCH-2 and parvin isoform β-parvin. Using a co-immunoprecipitation method, we also found that the PINCH-1-ILK-α-parvin (PIP) complex and Akt activation were significantly up-regulated. These observations were further corroborated with the mouse myocardial infarction (MI) and transaortic constriction (TAC) model. Thymosin beta4 (Tβ4), an effective cell penetrating peptide for treating MI, was found to further enhance the level of PIP components and Akt activation, while substantially suppressing NF-κB activation and collagen expression-the hallmarks of cardiac fibrosis. In the presence of an Akt inhibitor, wortmannin, we show that Tβ4 had a decreased effect in protecting the heart from MI. These data suggest that the PIP complex and activation of Akt play critical roles in HF development. Tβ4 treatment likely improves cardiac function by enhancing PIP mediated Akt activation and suppressing NF-κB activation and collagen-mediated fibrosis. These data provide significant insight into the role of the PIP-Akt pathway and its regulation by Tβ4 treatment in post-MI. PMID: 21625516 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Prolonged sinus pauses with hydromorphone in the absence of cardiac conduction disease. South Med J. 2011 Mar;104(3):239-40 Authors: Snarr BS, Rowley CP, Phan SV, Achanti A, Hendrix GH A 49-year-old male had open sigmoid colectomy with colorectal anastomosis for sigmoid diverticulitis. The patient was given patient-controlled analgesia (PCA) hydromorphone and subsequently developed bradycardia with prolonged sinus pauses up to 7.1 seconds. The pauses resolved shortly after the hydromorphone was discontinued. This is the first case report to our knowledge of reversible prolonged sinus pauses associated with the use of hydromorphone. Animal studies support a role for opioid signaling at the sinoatrial (SA) node. Hydromorphone is a potential cause of prolonged sinus pauses and should be taken into consideration when monitoring a patient on hydromorphone for pain control. PMID: 21297541 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Assessment of growth factor treatment on fibrochondrocyte and chondrocyte co-cultures for TMJ fibrocartilage engineering. Acta Biomater. 2011 Apr;7(4):1710-8 Authors: Kalpakci KN, Kim EJ, Athanasiou KA Treatments for patients suffering from severe temporomandibular joint (TMJ) dysfunction are limited, motivating the development of strategies for tissue regeneration. In this study, co-cultures of fibrochondrocytes (FCs) and articular chondrocytes (ACs) were seeded in agarose wells, and supplemented with growth factors, to engineer tissue with biomechanical properties and extracellular matrix composition similar to native TMJ fibrocartilage. In the first phase, growth factors were applied alone and in combination, in the presence or absence of serum, while in the second phase, the best overall treatment was applied at intermittent dosing. Continuous treatment of AC/FC co-cultures with TGF-β1 in serum-free medium resulted in constructs with glycosaminoglycan/wet weight ratios (12.2%), instantaneous compressive moduli (790 kPa), relaxed compressive moduli (120 kPa) and Young's moduli (1.87 MPa) that overlap with native TMJ disc values. Among co-culture groups, TGF-β1 treatment increased collagen deposition ∼20%, compressive stiffness ∼130% and Young's modulus ∼170% relative to controls without growth factor. Serum supplementation, though generally detrimental to functional properties, was identified as a powerful mediator of FC construct morphology. Finally, both intermittent and continuous TGF-β1 treatment showed positive effects, though continuous treatment resulted in greater enhancement of construct functional properties. This work proposes a strategy for regeneration of TMJ fibrocartilage and its future application will be realized through translation of these findings to clinically viable cell sources. PMID: 21185408 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Isolation and characterization of porcine amniotic fluid-derived multipotent stem cells. PLoS One. 2011;6(5):e19964 Authors: Chen J, Lu Z, Cheng D, Peng S, Wang H The aim of this study was to isolate and characterize porcine amniotic fluid-derived multipotent stem cells (pAF-MSC). The porcine amniotic fluid (AF) from the amniotic cavity of pregnant gilts in the early stages of gestation (at E35) was collected and centrifuged for 5-10 min at 400 g to pellet cells. The primary culture of AF showed the multiple cell types, including the epithelial-like cells and fibroblast-like cells. By culturing in AMM medium for 6 to 8 days, the epithelial-like cells disappeared and the remaining cells presented the fibroblastoid morphology. The doubling time of pAF-MSCs was about 34.6 h, and the cells had been continually cultured over 60 passages in vitro. The flow cytometry results showed that pAF-MSCs were positive for CD44, CD117 and CD166, but negative for CD34, CD45 and CD54. Meanwhile, pAF-MSCs expressed ES cell markers, such as Oct4, Nanog, SSEA4, Tra-1-60 and Tra-1-81. The ratio of CD117(+) CD44(+) cells accounted for 98% of pAF-MSCs population. Three germ layer markers, including FGF5 (ectodermal marker), AFP (endodermal marker) and Bra (mesodermal marker), were detected in embryoid bodies derived from pAF-MSCs. Under the different induction conditions, the pAF-MSCs were capable of differentiating into neurocytes, adipocytes and beating cardiomyocytes. Furthermore, the pAF-MSCs didn't form teratoma when injected into immunodeficiency mice. These optimal features of pAF-MSCs provide an excellent alternative stem cell resource for potential cell therapy in regenerative medicine and transgenic animals. PMID: 21625520 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Compositional control of poly(ethylene glycol) hydrogel modulus independent of mesh size. J Biomed Mater Res A. 2011 May 27; Authors: Browning MB, Wilems T, Hahn M, Cosgriff-Hernandez E Poly(ethylene glycol) (PEG) hydrogels are of great interest in tissue engineering because of their established biocompatibility, high permeability, and tunable material properties. However, rational design of PEG hydrogel scaffold properties has been inhibited by the interdependence of key material properties such as modulus and mesh size. This study examined the effect of an acrylated 4-arm PEG cross-linker on gel modulus and mesh size as a means of inducing local increases in cross-link density to decouple these two parameters. It was determined that adding the 4-arm PEG cross-linker to PEG hydrogels resulted in statistically significant increases in both tensile and compressive modulus while having minimal effects on overall gel mesh size. The incorporation of the 4-arm PEG cross-linker also broadened the range of achievable mechanical properties. This study provides the methodology to independently tune PEG hydrogel modulus and mesh size, which may be utilized in future investigations of the individual and combined effects of PEG hydrogel modulus and mesh size on cell behavior and viability. It also presents a more finely tunable hydrogel scaffold with utility in a broad range of tissue engineering applications. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 2011. PMID: 21626658 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Acute kidney injury and its management. Contrib Nephrol. 2011;171:218-25 Authors: Chuasuwan A, Kellum JA Acute kidney injury (AKI) is a life-threatening disorder, but one which is potentially reversible. This syndrome is a frequent and serious complication of hospitalized patients. When severe enough to require renal replacement therapy, hospital mortality approaches 60% and recovery among survivors may be as poor as 50%. Moreover, recent evidence using uniform definitions and classifications have revealed that even less severe forms of AKI are associated with reduced survival and other long-term adverse consequences, including progression of chronic kidney disease. Promising new biomarkers are becoming available and new strategies for prevention of AKI in specific situations are being developed. Advanced treatment options, including adsorptive therapy, the renal tubular assist device and stem cell therapy, are also on the horizon. Increasing knowledge in this field is beginning to fill in the missing jigsaw puzzle pieces and a more coherent picture is emerging. Challenges in management of AKI to reduce mortality are sill daunting, however, and more research is urgently needed. The combination of education, risk stratification, prevention, early detection, prompt therapeutic intervention, quality of supportive care, and innovative therapies offer the promise of improving outcomes in patients afflicted with this serious condition. PMID: 21625115 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Small RNAs Loom Large During Reprogramming. Cell Stem Cell. 2011 Jun 3;8(6):599-601 Authors: Sridharan R, Plath K In two independent Cell Stem Cell reports, the Morrisey and Mori groups show that human and mouse somatic cells can be reprogrammed to produce induced pluripotent stem cells by expressing microRNAs, completely eliminating the need for ectopic protein expression (Anokye-Danso et al., 2011; Miyoshi et al., 2011). PMID: 21624799 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Immunohistochemical evaluation of the heat shock response to nonablative fractional resurfacing. J Biomed Opt. 2010 Nov-Dec;15(6):068002 Authors: Hantash BM, Bedi VP, Struck SK, Chan KF Despite the emergence of nonablative fractional resurfacing (NFR) as a new therapeutic modality for skin photoaging, little is known about the molecular events that underlie the heat shock response to different treatment parameters. Human subjects are treated with a scanned 1550-nm fractional laser at pulse energies spanning 6 to 40 mJ and a 140-μm spot size. The heat shock response is assessed immunohistochemically immediately through 7 days posttreatment. At the immediately posttreatment time point, we observe subepidermal clefting in most sections. The basal epidermis and dermal zones of sparing are both found to express HSP47, but not HSP72. By day 1, expression of HSP72 is detected throughout the epidermis, while that of HSP47 remains restricted to the basal layer. Both proteins are detected surrounding the dermal portion of the microscopic treatment zone (MTZ). This pattern of expression persists through day 7 post-NFR, although neither protein is found within the MTZ. Immediately posttreatment, the mean collagen denaturation zone width is 50 μm at 6 mJ, increasing to 202 μm at 40 mJ. The zone of cell death exceeds the denaturation zone by 19 to 55% over this pulse energy range. The two zones converge by day 7 posttreatment. PMID: 21198215 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Limitations of the db/db mouse in translational wound healing research: Is the NONcNZO10 polygenic mouse model superior? Wound Repair Regen. 2010 Nov-Dec;18(6):605-13 Authors: Fang RC, Kryger ZB, Buck DW, De la Garza M, Galiano RD, Mustoe TA Murine models have provided valuable insights into the pathogenesis of both diabetes and chronic wounds. However, only a few published reports to date have investigated wound healing differences among the differing diabetic mouse models. The goal of the present study was to further define the wound healing deficiency phenotypes of streptozotocin-induced (STZ-induced), Akita, and db/db diabetic mice in comparison with a promising new polygenic strain of Type 2 diabetes (NONcNZO10) by using three specific wound models that targeted different critical processes in the pathogenesis of chronic wounds. Incisional, excisional, and ischemia/reperfusion wound models were established on mice of each strain. Wound healing parameters including tensile strength, epithelial gap, and wound necrosis were evaluated. In contrast to the other diabetic mice, the NONcNZO10 strain was found to have significant wound healing impairments in all wound healing models. Not only do the NONcNZO10 mice appear to better model human Type 2 diabetes, these provocative findings suggest that the mice may show more clinically relevant wound healing deficiencies than previous diabetic mouse models. PMID: 20955341 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Transcription factor-induced lineage selection of stem-cell-derived neural progenitor cells. Cell Stem Cell. 2011 Jun 3;8(6):663-75 Authors: Panman L, Andersson E, Alekseenko Z, Hedlund E, Kee N, Mong J, Uhde CW, Deng Q, Sandberg R, Stanton LW, Ericson J, Perlmann T The generation of specific types of neurons from stem cells offers important opportunities in regenerative medicine. However, future applications and proper verification of cell identities will require stringent ways to generate homogeneous neuronal cultures. Here we show that transcription factors like Lmx1a, Phox2b, Nkx2.2, and Olig2 can induce desired neuronal lineages from most expressing neural progenitor cells by a mechanism resembling developmental binary cell-fate switching. Such efficient selection of cell fate resulted in remarkable cellular enrichment that enabled global gene-expression validation of generated neurons and identification of previously unrecognized features in the studied cell lineages. Several sources of stem cells have a limited competence to differentiate into specific neuronal cell types; e.g., dopamine neurons. However, we show that the combination of factors that normally promote either regional or dedicated neuronal specification can overcome limitations in cellular competence and also promote efficient reprogramming in more remote neural contexts, including human neural progenitor cells. PMID: 21624811 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Effect of flow perfusion conditions in the chondrogenic differentiation of bone marrow stromal cells cultured onto starch based biodegradable scaffolds. Acta Biomater. 2011 Apr;7(4):1644-52 Authors: Gonçalves A, Costa P, Rodrigues MT, Dias IR, Reis RL, Gomes ME Cartilage tissue engineering (TE) typically involves the combination of a 3-D biodegradable polymeric support material, with primary chondrocytes or other cell types able to differentiate into chondrocytes. The culture environment in which cell-material constructs are created and stored is an important factor. Various bioreactors have been introduced in TE approaches to provide specific culturing environments that might promote and accelerate cells' potential for chondrogenic differentiation and enhance the production of cartilage extracellular matrix. The aim of the present study was to investigate the chondrogenic differentiation of goat bone marrow cells (GBMCs) under flow perfusion culture conditions. For that purpose, GBMCs were seeded into starch-polycaprolactone fiber mesh scaffolds and cultured in a flow perfusion bioreactor for up to 28 days using culture medium supplemented with transforming growth factor-β1. The tissue-engineered constructs were characterized after several end points (7, 14, 21 and 28 days) by histological staining and immunocytochemistry analysis, as well as by glycosaminoglycan and alkaline phosphatase quantification assays. In addition, the expression of typical chondrogenic markers was assessed by real-time reverse-transcription polymerase chain reaction analysis. In general, the results obtained suggest that a flow perfusion microenvironment favors the chondrogenic potential of GBMCs. PMID: 21130906 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | A nervous origin for fish stripes. PLoS Genet. 2011 May;7(5):e1002081 Authors: Kelsh RN, Barsh GS PMID: 21625563 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | [Biomechanical study on decellularized laryngeal scaffold in dogs.] Zhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi. 2011 Apr;46(4):331-335 Authors: Xu L, Cui PC, Chen ZF, Ma RN OBJECTIVE: To evaluate the biomechanical characteristics of the decellularized laryngeal scaffold. METHODS: Ten Chinese adult dogs were randomly divided into two groups: perfusion group (n = 5) and control group (n = 5). The acellular larynx scaffold was obtained from dogs through cranial thyroid arteries perfusion with detergents. Comparative examinations were performed by the macroscopic view, histological view (hematoxylin and eosin stain, Alcian blue stain and Masson stain), scanning electron microscope (SEM) and biomechanical properties between perfusion group and control group. RESULTS: Macroscopic view showed that the decellularized laryngeal scaffold appeared pale asphyxia. HE stain indicated that there were little acellular traces of muscle and mucosa. Alcian blue stain, Masson stain and scanning electron microscope (SEM) suggested that there were no obvious changes about lycosaminoglycan and collagen. The compressive modulus of thyroid cartilage was (1.06 ± 0.07) MPa (x(-) ± s) in experimental groups and (1.15 ± 0.11) MPa in control group, showing no significant difference (t = 1.424, P > 0.05), neither in compressive modulus of annular cartilage (1.68 ± 0.11) MPa in experimental groups and (1.67 ± 0.09) MPa in control group (t = 0.185, P > 0.05). The tensile strength of thyroid cartilage between experimental (5.74 ± 0.88) MPa and control groups (6.18 ± 1.33) MPa did not have the statistical significance (t = 0.627, P > 0.05). CONCLUSION: These results indicate that perfusion method can construct a perfect biomechanical acellular larynx scaffold which could be a better selection for laryngeal reconstruction with tissue engineering method. PMID: 21624255 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | A Novel Insight to the Functional Role of Stathmin 1 in IgE-Mediated Activation of RBL-2H3 Cells. Iran J Allergy Asthma Immunol. 2011 Jun;10(2):73-80 Authors: Sadroddiny E, J G Moir A, A Helm B IgE-mediated cell signaling, induced by cross-linking of high affinity receptor for IgE (FcεRI) in the presence of antigen (Ag), is a well known mechanism described for mast cell activation in allergy and hypersensitivity reactions, which induces a spectrum of cellular responses such as secretion and up-regulation of cell surface FcεRI. Although for several years IgE binding to FcεRI was considered to be a passive sensitization process, the outcomes of several recent studies have revealed a variety of different cellular responses to IgE binding compared to IgE plus Antigen binding. The present study applied a functional proteomics-based approach to investigate mast cell signaling events and provided new insights to FcεRI-mediated cell signaling in RBL-2H3.1 cells, and may point to the activation of alternative signaling pathways in response to IgE or IgE plus Ag. Comparative analysis by 2-D PAGE of RBL cells activated with IgE plus Ag for three and four hours compared to non-activated cells was followed by mass spectrometric protein identification and provided evidence for the induction of Stathmin 1 (STMN1) gene expression in response to IgE plus Ag activation.Complementary SDS-PAGE analysis showed a distinct up-regulation of STMN1 induction in response to challenge with IgE plus Ag compared to sensitization with IgE only. Phosphoproteomics analysis gave evidence for significant increase at phosphorylation of STMN1 on ser16 after 1min, though a slight rise at 5 min, and on ser38 after 1 and 5min sensitization with IgE and a similar result was observed for 1min IgE plus Ag-activation. IgE plus Ag-activation was also found to induce the phosphorylation of ser38 to a greater extent than sensitization with IgE. In contrast, IgE alone was more effective than IgE plus Ag at inducing phosphorylation of ser16. Collectively this study provides further insights into the role of stathmin 1 in FcRI-mediated activation of cells of mast cell lineage and might shed light on the diverse response of these cells to IgE or IgE plus Ag. PMID: 21625015 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | The tumor necrosis factor type 2 receptor plays a protective role in tumor necrosis factor-α-induced bone resorption lacunae on mouse calvariae. J Bone Miner Metab. 2011 Jun 1; Authors: Nagano K, Alles N, Mian AH, Shimoda A, Morimoto N, Tamura Y, Shimokawa H, Akiyoshi K, Ohya K, Aoki K Tumor necrosis factor (TNF)-α exerts its biological function via TNF type 1 and type 2 receptors (TNFR1 and TNFR2). We have previously reported that bone resorption induced by lipopolysaccharide (LPS) in TNFR2-deficient mice is accelerated compared to that in wild-type (WT) mice. Although these results suggested that TNFR2 might have a protective role in bone resorption, we could not exclude the possibility that TNFR2 has no role in bone resorption. To clarify the role of TNFR2, we developed a TNF-α-induced bone resorption model using cholesterol-bearing pullulan nanogel as a TNF-α carrier to minimize the influence of inflammatory cytokines other than TNF-α. Injections of human TNF-α (hTNF), an agonist of mouse TNFR1, stimulated bone resorption lacunae on the calvariae in WT mice, but mouse TNF-α (mTNF), an agonist of both mouse TNFR1 and TNFR2, could not. To eliminate the possibility that the TNFR1 agonistic effects of hTNF were stronger than those of mTNF, we used the same model in TNFR2-deficient mice. Injection of mTNF resulted in clear bone resorption lacunae to the same extent observed after using hTNF in the TNFR2-deficient mice. Histomorphometric analysis of osteoclast number supported the observed changes in bone resorption lacunae. These data suggest that TNFR2 has a protective role in TNF-α-induced bone resorption. PMID: 21626455 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | The potential of amniotic fluid stem cells for cellular therapy and tissue engineering. Expert Opin Biol Ther. 2011 May 31; Authors: Klemmt PA, Vafaizadeh V, Groner B Introduction: Foetal cells present in amniotic fluid (AF) have been used for many years to perform prenatal genetic screening. Recent reports suggested that these cells might have additional benefits. AF contains, in addition to committed and differentiated cells, a subpopulation with stem cell characteristics. AF-derived stem cells (AFS) have functions found in mesenchymal stem cells, but in addition, exhibit a potent expansion capacity and plasticity. AFS are able to undergo multi-lineage differentiation and produce progeny indicative of all three germ layers. Areas covered: The experimental approaches available to isolate AFS and their potential for tissue engineering, the repair of organs through cell replacement and tissue regeneration. Expert opinion: The deployment of AFS for tissue regeneration offers advantages over the use of embryonic or adult stem cells: i) AF represents a convenient and non-contested source for obtaining stem cells; ii) their derivation is relatively simple and rapid; iii) no feeder layers are required for their cultivation; iv) they display no spontaneous differentiation in culture; and v) their stem cell phenotype is not affected by long-term storage. The application of AFS for tissue replacement therapies in vivo is at a very early stage, but existing studies indicate great potential for clinical use. PMID: 21623704 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | [Cardiac stem cells]. Kardiol Pol. 2010 Oct;68(10):1163-7 Authors: Jadczyk T, Wojakowski W PMID: 20967718 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Toward a strategic plan for pulp healing: from repair to regeneration. Clin Oral Investig. 2011 Feb;15(1):1-2 Authors: Goldberg M, Schmalz G PMID: 21234623 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Epidermal growth factor, basic fibroblast growth factor and platelet-derived growth factor-bb can substitute for fetal bovine serum and compete with human platelet-rich plasma in the ex vivo expansion of mesenchymal stromal cells derived from adipose tissue. Cytotherapy. 2011 May 30; Authors: Chieregato K, Castegnaro S, Madeo D, Astori G, Pegoraro M, Rodeghiero F Abstract Background aims. Human mesenchymal stromal cells (MSC) are multipotent cells possessing self-renewal capacity, long-term viability and multilineage potential. We analyzed the effect of four different medium supplements on the expansion and differentiation of adipose tissue-derived MSC (ADSC) in order to avoid the use of xenogeneic serum. Methods. We compared fetal bovine serum (FBS) with 10% human platelet-rich plasma (hPRP), 3% human platelet-poor plasma (hPPP) and with a cytokine cocktail composed of epidermal growth factor (EGF), basic fibroblast growth factor (bFGF) and platelet-derived growth factor-bb (PDGFbb) added to 3% hPPP. This mixture was developed testing EGF, bFGF, granulocyte-colony-stimulating factor (G-CSF), hepatocyte growth factor (HGF), insulin-like growth factor (IGF-I), PDGFbb and transforming growth factor (TGF)-β1 added alone or in combination with hPPP. Results. Our data demonstrate that the addition of EGF, bFGF and PDGFbb, in a medium supplemented with hPPP, obtainable from 150-200 mL whole autologous blood, supports ADSC expansion better than FBS, as confirmed by cumulative population doublings (cPD; 15.0 ± 0.5 versus 9.4 ± 2.8). The addition of human platelet-rich plasma (hPRP) further improved ADSC proliferation (cPD 20.0 ± 1.2), but the achievement of hPRP presented a major drawback, requiring 1000-1200 mL autologous or donor whole blood. The medium supplements did not influence ADSC phenotype: they expressed CD105, CD90 and CD44 lacking hematopoietic antigens. The exposure to the proposed cocktail or to hPRP increased adipogenic and osteogenic differentiation. Conclusions. The addition of EGF, bFGF and PDGFbb to hPPP could ensure a sufficient number of ADSC for clinical applications, avoiding the use of animal serum and representing a novel approach in regenerative medicine. PMID: 21623669 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Effect of Boron on Osteogenic Differentiation of Human Bone Marrow Stromal Cells. Biol Trace Elem Res. 2011 May 31; Authors: Ying X, Cheng S, Wang W, Lin Z, Chen Q, Zhang W, Kou D, Shen Y, Cheng X, Rompis FA, Peng L, Zhu Lu C Bone marrow stromal cells (BMSCs) have been well established as an ideal source of cell-based therapy for bone tissue engineering applications. Boron (B) is a notable trace element in humans; so far, the effects of boron on the osteogenic differentiation of BMSCs have not been reported. The aim of this study was to evaluate the effects of boron (0, 1, 10,100, and 1,000 ng/ml) on osteogenic differentiation of human BMSCs. In this study, BMSCs proliferation was analyzed by cell counting kit-8 (CCK8) assay, and cell osteogenic differentiation was evaluated by alkaline phosphatase (ALP) activity assay, Von Kossa staining, and real-time PCR. The results indicated that the proliferation of BMSCs was no different from the control group when added with B at the concentration of 1, 10, and 100 ng/ml respectively (P > 0.05); in contrast, 1,000 ng/ml B inhibited the proliferation of BMSCs at days 4, 7, and 14 (P < 0.05). By ALP staining, we discovered that BMSCs treated with 10 and 100 ng/ml B presented a higher ALP activity compared with control (P < 0.05). By real-time PCR, we detected the messenger RNA expression of ALP, osteocalcin, collagen type I, and bone morphogenetic proteins 7 were also increased in 10 and 100 ng/ml B treatment groups (P < 0.05). The calcium depositions were increased in 1 and 10 ng/ml B treatment groups (P < 0.05). Taken all together, it was the first time to report that B could increase osteogenic effect by stimulating osteogenic differentiation-related marker gene synthesis during the proliferation and differentiation phase in human BMSCs and could be a promising approach for enhancing osteogenic capacity of cell-based construction in bone tissue engineering. PMID: 21625915 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Impact of acute kidney injury on chronic kidney disease and its progression. Contrib Nephrol. 2011;171:213-7 Authors: Sanoff S, Okusa MD Acute kidney injury (AKI) is a devastating clinical problem that affects a growing number of patients, especially elderly ones, and is associated with high morbidity and mortality. It was previously thought that patients who survive an episode of AKI recover renal function without further sequelae; however, recent population- based studies suggest that this may not be the case. New clinical studies suggest that a strikingly large percentage of patients who have AKI do not fully recover renal function or require permanent renal replacement therapy, and that this population has an important impact on the epidemiology of chronic kidney disease (CKD) and end-stage renal disease. These clinical studies verify animal studies that have established a link between AKI and CKD progression. Future clinical studies are underway to prospectively characterize the natural history of AKI and CKD progression and to identify predictive biomarkers. PMID: 21625114 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Fibrillar films obtained from sodium soap fibers and polyelectrolyte multilayers. J Biomed Mater Res A. 2011 May 27; Authors: Zawko SA, Schmidt CE An objective of tissue engineering is to create synthetic polymer scaffolds with a fibrillar microstructure similar to the extracellular matrix. Here, we present a novel method for creating polymer fibers using the layer-by-layer method and sacrificial templates composed of sodium soap fibers. Soap fibers were prepared from neutralized fatty acids using a sodium chloride crystal dissolution method. Polyelectrolyte multilayers (PEMs) of polystyrene sulfonate and polyallylamine hydrochloride were deposited onto the soap fibers, crosslinked with glutaraldehyde, and then the soap fibers were leached with warm water and ethanol. The morphology of the resulting PEM structures was a dense network of fibers surrounded by a nonfibrillar matrix. Microscopy revealed that the PEM fibers were solid structures, presumably composed of polyelectrolytes complexed with residual fatty acids. These fibrillar PEM films were found to support the attachment of human dermal fibroblasts. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 2011. PMID: 21626660 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Melt-derived bioactive glass scaffolds produced by a gel-cast foaming technique. Acta Biomater. 2011 Apr;7(4):1807-16 Authors: Wu ZY, Hill RG, Yue S, Nightingale D, Lee PD, Jones JR Porous melt-derived bioactive glass scaffolds with interconnected pore networks suitable for bone regeneration were produced without the glass crystallizing. ICIE 16 (49.46% SiO(2), 36.27% CaO, 6.6% Na(2)O, 1.07% P(2)O(5) and 6.6% K(2)O, in mol.%) was used as it is a composition designed not to crystallize during sintering. Glass powder was made into porous scaffolds by using the gel-cast foaming technique. All variables in the process were investigated systematically to devise an optimal process. Interconnect size was quantified using mercury porosimetry and X-ray microtomography (μCT). The reagents, their relative quantities and thermal processing protocols were all critical to obtain a successful scaffold. Particularly important were particle size (a modal size of 8 μm was optimal); water and catalyst content; initiator vitality and content; as well as the thermal processing protocol. Once an optimal process was chosen, the scaffolds were tested in simulated body fluid (SBF) solution. Amorphous calcium phosphate formed in 8h and crystallized hydroxycarbonate apatite (HCA) formed in 3 days. The compressive strength was approximately 2 MPa for a mean interconnect size of 140 μm between the pores with a mean diameter of 379 μm, which is thought to be a suitable porous network for vascularized bone regeneration. This material has the potential to bond to bone more rapidly and stimulate more bone growth than current porous artificial bone grafts. PMID: 21130188 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Pulp tissue from primary teeth: new source of stem cells. J Appl Oral Sci. 2011 Jun;19(3):189-94 Authors: Telles PD, Machado MA, Sakai VT, Nör JE SHED (stem cells from human exfoliated deciduous teeth) represent a population of postnatal stem cells capable of extensive proliferation and multipotential differentiation. Primary teeth may be an ideal source of postnatal stem cells to regenerate tooth structures and bone, and possibly to treat neural tissue injury or degenerative diseases. SHED are highly proliferative cells derived from an accessible tissue source, and therefore hold potential for providing enough cells for clinical applications. In this review, we describe the current knowledge about dental pulp stem cells and discuss tissue engineering approaches that use SHED to replace irreversibly inflamed or necrotic pulps with a healthy and functionally competent tissue that is capable of forming new dentin. PMID: 21625731 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Modulation of immunological properties of allogeneic mesenchymal stem cells by collagen scaffolds in cartilage tissue engineering. J Biomed Mater Res A. 2011 May 27; Authors: Yuan T, Li K, Guo L, Fan H, Zhang X Influence of the structures of some collagen scaffolds on immunological properties of the seeded allogeneic mesenchymal stem cells (MSCs) was studied in this article. Hydrogels, sponge, and membrane were prepared from type-I collagen. These scaffolds were seeded with neonatal rabbit MSCs and cultured for different periods. Changes of the immunological properties associated with different scaffolds were analyzed and compared. It was found that the expression of major histocompatibility complex (MHC) class I and II molecules on MSCs increased gradually in all scaffolds, but the least increment was recorded in hydrogels. Mixed lymphocyte reactions (MLR) showed that the MSC-hydrogel constructs invoked considerably low allogeneic lymphocytes proliferation. Even in presence of interferon-γ (IFN-γ), the hydrogels with higher concentration gave comparatively lower increment of MHC-II expression and allogeneic lymphocytes proliferation. These results suggest that different scaffold structures may provide different microenvironments and extents of isolation from the host immune system for the seed cells, thereby affecting their immunological properties. Therefore, scaffold structures may modulate the immunological properties of tissue-engineered cartilage with allogeneic cells. Hydrogels, especially which were prepared from higher collagen concentrations, were found to be a promising scaffold structure, from the perspective of avoiding severe immune rejection. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 2011. PMID: 21626664 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Platelet endothelial cell adhesion molecule-1, stage-specific embryonic antigen-1, and Flk-1 mark distinct populations of mouse embryonic stem cells during differentiation toward hematopoietic/endothelial cells. Stem Cells Dev. 2010 Dec;19(12):1937-48 Authors: Yue W, Pi QM, Zhang WJ, Zhou GD, Cui L, Liu W, Cao Y Vascular endothelial cells (ECs) and most hematopoietic cells express platelet endothelial cell adhesion molecule-1 (PECAM-1), which is the cell surface protein also expressed in mouse embryonic stem (ES) cells. To better understand how PECAM-1(+) ES cells differentiate into PECAM-1(+) hematopoietic cells/ECs, 3 cell surface markers, PECAM-1, stage-specific embryonic antigen-1 (SSEA-1), and Flk-1, were utilized to dissect the developmental process during ES cell differentiation in vitro. Undifferentiated ES cells expressed PECAM-1, with a majority of them coexpressing SSEA-1. During ES cell differentiation, expression of PECAM-1 decreased to give rise to PECAM-1⁻/SSEA-1(+) cells, which represented epiblast stem cells. Subsequently, Flk-1-expressing cells developed from PECAM-1⁻/SSEA-1(+) cells, becoming SSEA-1⁻/Flk-1(+) through the downregulation of SSEA-1 expression. Following this, a second wave of PECAM-1 expression, which represented the mature hematopoietic cells/ECs, developed from Flk-1(+) cells. Also, a small portion of PECAM-1(+)/SSEA-1(+) cells, which represented the residual undifferentiated ES cells, were consistently observed in long-term differentiated embryoid bodies. This work revealed a sequential change in PECAM-1, SSEA-1, and Flk-1 expression during ES cell differentiation; therefore, they could be valuable cell surface markers for isolating cells at distinct developmental stages in ES cell differentiation. PMID: 20491542 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Hierarchical organization and early hematopoietic specification of the developing HSC lineage in the AGM region. J Exp Med. 2011 May 30; Authors: Rybtsov S, Sobiesiak M, Taoudi S, Souilhol C, Senserrich J, Liakhovitskaia A, Ivanovs A, Frampton J, Zhao S, Medvinsky A The aorta-gonad-mesonephros region plays an important role in hematopoietic stem cell (HSC) development during mouse embryogenesis. The vascular endothelial cadherin(+) CD45(+) (VE-cad(+)CD45(+)) population contains the major type of immature pre-HSCs capable of developing into long-term repopulating definitive HSCs. In this study, we developed a new coaggregation culture system, which supports maturation of a novel population of CD45-negative (VE-cad(+)CD45(-)CD41(+)) pre-HSCs into definitive HSCs. The appearance of these pre-HSCs precedes development of the VE-cad(+)CD45(+) pre-HSCs (termed here type I and type II pre-HSCs, respectively), thus establishing a hierarchical directionality in the developing HSC lineage. By labeling the luminal surface of the dorsal aorta, we show that both type I and type II pre-HSCs are distributed broadly within the endothelial and subendothelial aortic layers, in contrast to mature definitive HSCs which localize to the aortic endothelial layer. In agreement with expression of CD41 in pre-HSCs, in vivo CD41-Cre-mediated genetic tagging occurs in embryonic pre-HSCs and persists in all lymphomyeloid lineages of the adult animal. PMID: 21624936 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Hedgehog/Wnt feedback supports regenerative proliferation of epithelial stem cells in bladder. Nature. 2011 Apr 7;472(7341):110-4 Authors: Shin K, Lee J, Guo N, Kim J, Lim A, Qu L, Mysorekar IU, Beachy PA Epithelial integrity in metazoan organs is maintained through the regulated proliferation and differentiation of organ-specific stem and progenitor cells. Although the epithelia of organs such as the intestine regenerate constantly and thus remain continuously proliferative, other organs, such as the mammalian urinary bladder, shift from near-quiescence to a highly proliferative state in response to epithelial injury. The cellular and molecular mechanisms underlying this injury-induced mode of regenerative response are poorly defined. Here we show in mice that the proliferative response to bacterial infection or chemical injury within the bladder is regulated by signal feedback between basal cells of the urothelium and the stromal cells that underlie them. We demonstrate that these basal cells include stem cells capable of regenerating all cell types within the urothelium, and are marked by expression of the secreted protein signal Sonic hedgehog (Shh). On injury, Shh expression in these basal cells increases and elicits increased stromal expression of Wnt protein signals, which in turn stimulate the proliferation of both urothelial and stromal cells. The heightened activity of this signal feedback circuit and the associated increase in cell proliferation appear to be required for restoration of urothelial function and, in the case of bacterial injury, may help clear and prevent further spread of infection. Our findings provide a conceptual framework for injury-induced epithelial regeneration in endodermal organs, and may provide a basis for understanding the roles of signalling pathways in cancer growth and metastasis. PMID: 21389986 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Two novel recessive mutations in KRT14 identified in a cohort of 21 Spanish families with epidermolysis bullosa simplex. Br J Dermatol. 2011 May 28; Authors: García M, Santiago JL, Terrón A, Hernández-Martín A, Vicente A, Fortuny C, De Lucas R, López JC, Cuadrado-Corrales N, Holguín A, Illera N, Duarte B, Sánchez-Jimeno C, Llames S, García E, Ayuso C, Martínez-Santamaría L, Castiglia D, De Luca N, Torrelo A, Mechan D, Baty D, Zambruno G, Escámez MJ, Del Río M Background: Basal epidermolysis bullosa simplex (EBS) is a group of blistering genodermatoses mostly caused by mutations in the keratin genes, KRT5 and KRT14. Recessive mutations represent about 5% of all EBS mutations, being common and specific in populations with high consanguinity, where affected patients show severe phenotypes. Objective: Accomplish the first mutational analysis in EBS patients of Spanish origin and delineate a comprehensive genotype-phenotype correlation. Patients/Methods: 21 EBS families were analyzed. Immunofluorescence mapping at dermo-epidermal junction level was performed on patient skin biopsies. Mutation screening of the entire coding sequences of KRT5 and KRT14 in genomic DNA was assessed by PCR and direct sequencing. Results: KRT5 or KRT14 causative mutations were identified in 18 of the 21 EBS families. 14 different mutations were disclosed, of which 12 were dominant missense mutations and two truncating recessive mutations. Five of the 14 mutations were novel including three dominant in KRT5 (p.V186E, p.T321P and p.A428T) and two recessive in KRT14 (p.K116X and p.K250RfsX8). The two EBS patients carrying homozygous recessive mutations were affected by severe phenotypes and belong to consanguineous families. All 5 families with EBS Dowling-Meara subtype (EBS-DM), carried recurrent mutations affecting the highly conserved ends of the alpha-helical rod domain of K5 and K14. The seven mutations associated to localized EBS subtype (EBS-loc) were widely distributed along KRT5 and KRT14 genes. Two families with mottled pigmentation (EBS-MP) carried the P25L mutation in KRT5, commonly associated with this subtype. Conclusions: This study further confirms the genotype-phenotype correlation established for EBS in other ethnic groups, being the first in a Mediterranean country (excluding Israel). This study adds two novel recessive mutations to the world record so far including a total of 14 mutations. As in previous reports, recessive mutations resulted in lack of keratin K14, giving rise to a generalized and severe presentation. PMID: 21623745 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | A novel strontium-doped calcium polyphosphate/erythromycin/poly(vinyl alcohol) composite for bone tissue engineering. J Biomed Mater Res A. 2011 May 27; Authors: Song W, Ren W, Wan C, Esquivel AO, Shi T, Blasier R, Markel DC It is our goal to develop bactericidal bone scaffolds with osteointegration potential. In this study, poly(vinyl alcohol) (PVA) coating (7%) was applied to an erythromycin (EM)-impregnated strontium-doped calcium polyphosphate (SCPP) scaffold using a simple slurry dipping method. MicroCT analysis showed that PVA coating reduced the average pore size and the percentage of pore interconnectivity to some extent. Compressive strength tests confirmed that the PVA coating significantly increased material elasticity and slightly enhanced the scaffold mechanical strength. It was also confirmed that the PVA coatings allowed a sustained EM release that is controlled by diffusion through the intact PVA hydrogel layer, irrespective of the drug solubility. PVA coating did not inhibit the EM bioactivity when the scaffolds were immersed in simulated body fluid for up to 4 weeks. EM released from SCPP-EM-PVA composite scaffolds maintained its capability of bacterial growth (S. aureus) inhibition. PVA coating is biocompatible and nontoxic to MC3T3 preosteoblast cells. Furthermore, we found that SCPP-EM-PVA composite scaffolds and their eluants remarkably inhibited RANKL-induced osteoclastogenesis in a murine RAW 264.7 macrophage cell line. Thus, this unique multifunctional bioactive composite scaffold has the potential to provide controlled delivery of relevant drugs for bone tissue engineering. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 2011. PMID: 21626667 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Novel soybean/gelatine-based bioactive and injectable hydroxyapatite foam: material properties and cell response. Acta Biomater. 2011 Apr;7(4):1780-7 Authors: Perut F, Montufar EB, Ciapetti G, Santin M, Salvage J, Traykova T, Planell JA, Ginebra MP, Baldini N Despite their known osteoconductivity, clinical use of calcium phosphate cements is limited both by their relatively slow rate of resorption and by rheological properties incompatible with injectability. Bone in-growth and material resorption have been improved by the development of porous calcium phosphate cements. However, injectable formulations have so far only been obtained through the addition of relatively toxic surfactants. The present work describes the response of osteoblasts to a novel injectable foamed bone cement based on a composite formulation including the bioactive foaming agents soybean and gelatine. The foaming properties of both defatted soybean and gelatine gels were exploited to develop a self-hardening soy/gelatine/hydroxyapatite composite foam able to retain porosity upon injection. After setting, the foamed paste produced a calcium-deficient hydroxyapatite scaffold, showing good injectability and cohesion as well as interconnected porosity after injection. The intrinsic bioactivity of soybean and gelatine was shown to favour osteoblast adhesion and growth. These findings suggest that injectable, porous and bioactive calcium phosphate cements can be produced for bone regeneration through minimally invasive surgery. PMID: 21163370 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Local expression of indoleamine 2,3-dioxygenase suppresses T-cell-mediated rejection of an engineered bilayer skin substitute. Wound Repair Regen. 2010 Nov-Dec;18(6):614-23 Authors: Forouzandeh F, Jalili RB, Hartwell RV, Allan SE, Boyce S, Supp D, Ghahary A Engineered skin substitutes (ESSs) comprising both keratinocytes and fibroblasts can afford many advantages over the use of autologous keratinocyte grafts for the treatment of full-thickness and partial-thickness burns. In this study, we investigated the efficacy of a novel ESS containing both genetically altered fibroblasts that express the immunosuppressive factor indoleamine 2,3-dioxygenase (IDO) and primary keratinocytes from a nonautologous source to confer immune protection of xenogeneic cells cultured in a bilayer ESS. The results show that engraftment of IDO expressing skin substitutes on the back of rats significantly improves healing progression over 7 days compared with both nontreated and non-IDO-expressing skin substitutes (p<0.001). Immuno-staining of CD3 and CD31 suggests that IDO-expressing skin substitutes significantly suppress T cell infiltration (p<0.001) and improve neovascularization by four-fold (12.6±1.2 vs. 3.0±1.0 vessel-like structure/high power field), respectively. In conclusion, we found that IDO expression can improve the efficacy of nonautologous ESS for the purpose of wound healing by mitigating T-cell infiltration as well as promoting vascularization of the graft. PMID: 20955343 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | miR-371-3 Expression Predicts Neural Differentiation Propensity in Human Pluripotent Stem Cells. Cell Stem Cell. 2011 Jun 3;8(6):695-706 Authors: Kim H, Lee G, Ganat Y, Papapetrou EP, Lipchina I, Socci ND, Sadelain M, Studer L The use of pluripotent stem cells in regenerative medicine and disease modeling is complicated by the variation in differentiation properties between lines. In this study, we characterized 13 human embryonic stem cell (hESC) and 26 human induced pluripotent stem cell (hiPSC) lines to identify markers that predict neural differentiation behavior. At a general level, markers previously known to distinguish mouse ESCs from epiblast stem cells (EPI-SCs) correlated with neural differentiation behavior. More specifically, quantitative analysis of miR-371-3 expression prospectively identified hESC and hiPSC lines with differential neurogenic differentiation propensity and in vivo dopamine neuron engraftment potential. Transient KLF4 transduction increased miR-371-3 expression and altered neurogenic behavior and pluripotency marker expression. Conversely, suppression of miR-371-3 expression in KLF4-transduced cells rescued neural differentiation propensity. miR-371-3 expression level therefore appears to have both a predictive and a functional role in determining human pluripotent stem cell neurogenic differentiation behavior. PMID: 21624813 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Endogenous tissue engineering: PTH therapy for skeletal repair. Cell Tissue Res. 2011 May 31; Authors: Takahata M, Awad HA, O'Keefe RJ, Bukata SV, Schwarz EM Based on its proven anabolic effects on bone in osteoporosis patients, recombinant parathyroid hormone (PTH(1-34)) has been evaluated as a potential therapy for skeletal repair. In animals, the effect of PTH(1-34) has been investigated in various skeletal repair models such as fractures, allografting, spinal arthrodesis and distraction osteogenesis. These studies have demonstrated that intermittent PTH(1-34) treatment enhances and accelerates the skeletal repair process via a number of mechanisms, which include effects on mesenchymal stem cells, angiogenesis, chondrogenesis, bone formation and resorption. Furthermore, PTH(1-34) has been shown to enhance bone repair in challenged animal models of aging, inflammatory arthritis and glucocorticoid-induced bone loss. This pre-clinical success has led to off-label clinical use and a number of case reports documenting PTH(1-34) treatment of delayed-unions and non-unions have been published. Although a recently completed phase 2 clinical trial of PTH(1-34) treatment of patients with radius fracture has failed to achieve its primary outcome, largely because of effective healing in the placebo group, several secondary outcomes are statistically significant, highlighting important issues concerning the appropriate patient population for PTH(1-34) therapy in skeletal repair. Here, we review our current knowledge of the effects of PTH(1-34) therapy for bone healing, enumerate several critical unresolved issues (e.g., appropriate dosing regimen and indications) and discuss the long-term potential of this drug as an adjuvant for endogenous tissue engineering. PMID: 21626290 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |  | |  | |  |
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