|  |  |  | | | | | TE-RegenMed-StemCell feed | | | | | | | | | | | | | | | | | | The California stem cell agency today posted additional material for its directors meeting Thursday dealing with loan payback changes in its biotech loan program along with an update on its operational budget.
You can find a memo summarizing the loan changes here and the proposed regulations here. Obviously these come much too late – less than two days before the meeting – to expect | | | | | | | | | | | | | | | | | | | | | | | | Back in August, directors of the California stem cell agency authorized a $615,000 study of their $3 billion enterprise by the prestigious Institute of Medicine at the National Academies of Science.
As of last week, a contract for the work had not been signed, although the two-year study was originally scheduled to be completed by September 2012 -- in time for a ballot measure campaign for an | | | | | | | | | | | | | | | | | | | | | | | | | Animal models of cardiac disease and stem cell therapy. Open Cardiovasc Med J. 2010;4:231-9 Authors: Ou L, Li W, Liu Y, Zhang Y, Jie S, Kong D, Steinhoff G, Ma N Animal models that mimic cardiovascular diseases are indispensable tools for understanding the mechanisms underlying the diseases at the cellular and molecular level. This review focuses on various methods in preclinical research to create small animal models of cardiac diseases, such as myocardial infarction, dilated cardiomyopathy, heart failure, myocarditis and cardiac hypertrophy, and the related stem cell treatment for these diseases. PMID: 21258568 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Autologous bone marrow-derived mesenchymal stromal cells in the treatment of fistulising Crohn's disease. Gut. 2011 Jan 21; Authors: Ciccocioppo R, Bernardo ME, Sgarella A, Maccario R, Avanzini MA, Ubezio C, Minelli A, Alvisi C, Vanoli A, Calliada F, Dionigi P, Perotti C, Locatelli F, Corazza GR Objective External fistulas represent a disabling manifestation of Crohn's disease with a difficult curability and a high relapse rate despite a large therapeutic armamentarium. Stem cell therapy is a novel and promising approach for treatment of chronic inflammatory conditions. We therefore investigated the feasibility, safety and efficacy of serial intrafistular injections of autologous bone marrow-derived mesenchymal stromal cells (MSCs) in the treatment of fistulising Crohn's disease. Patients and methods We enrolled 12 consecutive outpatients (eight males, median age 32 years) refractory to or unsuitable for current available therapies. MSCs were isolated from bone marrow and expanded ex vivo to be used for both therapeutic and experimental purposes. Ten patients (two refused) received intrafistular MSC injections (median 4) scheduled every 4 weeks, and were monitored by surgical, MRI and endoscopic evaluation for 12 months afterwards. The feasibility of obtaining at least 50×10(6) MSCs from each patient, the appearance of adverse events, and the efficacy in terms of fistula healing and reduction of both Crohn's disease and perianal disease activity indexes were evaluated. In addition, the percentage of both mucosal and circulating regulatory T cells expressing FoxP3, and the ability of MSCs to influence mucosal T cell apoptosis were investigated. Results MSC expansion was successful in all cases; sustained complete closure (seven cases) or incomplete closure (three cases) of fistula tracks with a parallel reduction of Crohn's disease and perianal disease activity indexes (p<0.01 for both), and rectal mucosal healing were induced by treatment without any adverse effects. The percentage of mucosal and circulating regulatory T cells significantly increased during the treatment and remained stable until the end of follow up (p<0.0001 and p<0.01, respectively). Furthermore, MSCs have been proven to affect mucosal T cell apoptotic rate. Conclusions Locally injected MSCs represent a feasible, safe and beneficial therapy in refractory fistulising Crohn's disease. PMID: 21257987 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | In vivo effects of isolated implantation of salmon-derived crosslinked atelocollagen sponge into an osteochondral defect. J Mater Sci Mater Med. 2011 Jan 23; Authors: Kawaguchi Y, Kondo E, Kitamura N, Arakaki K, Tanaka Y, Munekata M, Nagai N, Yasuda K We have developed crosslinked salmon-derived atelocollagen (SC) sponge, which has a denaturation temperature of 47°C. Sixty-four knees of 32 mature rabbits were randomly divided into 4 groups after creating an osteochondral defect in the femoral trochlea. Defects in Groups I, II, and III were filled with the crosslinked SC sponge, the crosslinked porcine collagen (PC) sponge, and the non-crosslinked PC sponge, respectively. In Group IV, defects were left untreated as the control. At 12 weeks after implantation, the histological score showed that Group I was significantly greater than Groups III (P = 0.0196) and IV (P = 0.0021). In addition, gene expression of type-2 collagen, aggrecan, and SOX9 was the greatest in Group I at 12 weeks. The fundamental in vivo properties of the crosslinked SC sponge showed that this is a promising biomaterial, specifically as a scaffold for cartilage tissue engineering. PMID: 21259035 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Effect of blasting treatment and Fn coating on MG63 adhesion and differentiation on titanium: a gene expression study using real-time RT-PCR. J Mater Sci Mater Med. 2011 Jan 22; Authors: Pegueroles M, Aguirre A, Engel E, Pavon G, Gil FJ, Planell JA, Migonney V, Aparicio C Biomaterial surface properties, via alterations in the adsorbed protein layer, and the presence of specific functional groups can influence integrin binding specificity, thereby modulating cell adhesion and differentiation processes. The adsorption of fibronectin, a protein directly involved in osteoblast adhesion to the extracellular matrix, has been related to different physical and chemical properties of biomaterial surfaces. This study used blasting particles of different sizes and chemical compositions to evaluate the response of MG63 osteoblast-like cells on smooth and blasted titanium surfaces, with and without fibronectin coatings, by means of real-time reverse transcription-polymerase chain reaction (qRT-PCR) assays. This response included (a) expression of the α(5), α(v) and α(3) integrin subunits, which can bind to fibronectin through the RGD binding site, and (b) expression of alkaline phosphatase (ALP) and osteocalcin (OC) as cell-differentiation markers. ALP activity and synthesis of OC were also tested. Cells on SiC-blasted Ti surfaces expressed higher amounts of the α(5) mRNA gene than cells on Al(2)O(3)-blasted Ti surfaces. This may be related to the fact that SiC-blasted surfaces adsorbed higher amounts of fibronectin due to their higher surface free energy and therefore provided a higher number of specific cell-binding sites. Fn-coated Ti surfaces decreased α(5) mRNA gene expression, by favoring the formation of other integrins involved in adhesion over α(5)β(1). The changes in α(5) mRNA expression induced by the presence of fibronectin coatings may moreover influence the osteoblast differentiation pathway, as fibronectin coatings on Ti surfaces also decreased both ALP mRNA expression and ALP activity after 14 and 21 days of cell culture. PMID: 21258846 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Recapitulation of the embryonic cardiovascular progenitor cell niche. Biomaterials. 2011 Jan 21; Authors: Schenke-Layland K, Nsair A, Van Handel B, Angelis E, Gluck JM, Votteler M, Goldhaber JI, Mikkola HK, Kahn M, Maclellan WR Stem or progenitor cell populations are often established in unique niche microenvironments that regulate cell fate decisions. Although niches have been shown to be critical for the normal development of several tissues, their role in the cardiovascular system is poorly understood. In this study, we characterized the cardiovascular progenitor cell (CPC) niche in developing human and mouse hearts, identifying signaling pathways and extracellular matrix (ECM) proteins that are crucial for CPC maintenance and expansion. We demonstrate that collagen IV (ColIV) and β-catenin-dependent signaling are essential for maintaining and expanding undifferentiated CPCs. Since niches are three-dimensional (3D) structures, we investigated the impact of a 3D microenvironment that mimics the in vivo niche ECM. Employing electrospinning technologies, 3D in vitro niche substrates were bioengineered to serve as culture inserts. The three-dimensionality of these structures increased mouse embryonic stem cell differentiation into CPCs when compared to 2D control cultures, which was further enhanced by incorporation of ColIV into the substrates. Inhibiting p300-dependent β-catenin signals with the small molecule IQ1 facilitated further expansion of CPCs. Our study represents an innovative approach to bioengineer cardiac niches that can serve as unique 3D in vitro systems to facilitate CPC expansion and study CPC biology. PMID: 21257198 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | An In Vitro Study of Two GAG-like Marine Polysaccharides as Compounds of Injectable Hydrogel for Bone and Cartilage Tissue Engineering. Acta Biomater. 2011 Jan 20; Authors: Rederstorff E, Weiss P, Sourice S, Pilet P, Xie F, Sinquin C, Colliec-Jouault S, Guicheux J, Laïb S Natural polysaccharides are attractive compounds to build scaffolds for bone and cartilage tissue engineering. Here we tested two non standard ones, HE800 and GY785, for the 2D and 3D culture of osteoblasts (MC3T3-E1) and chondrocytes (C28/I2). These two GAG-like marine exopolysaccharides were incorporated into an injectable silylated hydroxypropylmethylcellulose-based hydrogel (Si-HPMC) that has already shown its suitability for bone and cartilage tissue engineering. Results showed that similarly to hyaluronic acid (the control) HE800 and GY785 significantly improved the mechanical properties of the Si-HPMC hydrogel and induced the attachment of MC3T3-E1 and C28/I2 cells when these were cultured on the top of the scaffolds. Si-HPMC hydrogel containing 0.67% of HE800 exhibited the highest compressive modulus (11kPa) and allowed the best cell dispersion, especially with MC3T3-E1. However these cells did not survive when cultured in 3D within hydrogels containing HE800, in contrary to C28/I2 cells. The latter proliferated in the microenvironment or concentrically depending on the nature of the hydrogel. Among all the constructs tested, the Si-HPMC hydrogels containing 0.34% of HE800 or 0.67% of GY785 or 0.67% of Hyaluronic acid (HA) presented the most interesting features for cartilage tissue engineering applications since they offered the highest compressive modulus (9.5-11kPa) while supporting the proliferation of chondrocytes. PMID: 21256989 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Sensing scaffolds to monitor cellular activity using impedance measurements. Biosens Bioelectron. 2011 Jan 8; Authors: Whulanza Y, Ucciferri N, Domenici C, Vozzi G, Ahluwalia A Scaffolds are cell adhesive matrices for the realisation of tissue constructs. Here we describe how scaffolds for tissue engineering can also be used as sensors for monitoring cellular activity such as adhesion and spreading. Carbon nanotube polymer composites were fabricated into membranes and scaffolds with electro-conductive properties. Impedance techniques were used to measure the effects of media and cell cultures on composite membranes and the results were analysed using lumped parameter models. We show that protein adhesion can be distinguished from cell adhesion as the impedance changes are much smaller for the latter (5%). In the presence of cells, impedance changes are of the order of 40% and can be correlated with adhesion, spreading and changes in cell density. PMID: 21256732 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Cell patterning technologies for organotypic tissue fabrication. Trends Biotechnol. 2011 Jan 20; Authors: Guillotin B, Guillemot F Bottom-up tissue engineering technologies address two of the main limitations of top-down tissue engineering approaches: the control of mass transfer and the fabrication of a controlled and functional histoarchitecture. These emerging technologies encompass mesoscale (e.g. cell sheets, cell-laden hydrogels and 3D printing) and microscale technologies (e.g. inkjet printing and laser-assisted bioprinting), which are used to manipulate and assemble cell-laden building blocks whose thicknesses correspond to the diffusion limit of metabolites, and present the capacity for cell patterning with microscale precision, respectively. Here, we review recent technological advances and further discuss how these technologies are complementary, and could therefore be combined for the biofabrication of organotypic tissues either in vitro, thus serving as realistic tissue models, or within a clinic setting. PMID: 21256609 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Use of an autologous bioengineered composite skin in extensive burns: Clinical and functional outcomes. A multicentric study. Burns. 2011 Jan 19; Authors: Gómez C, Galán JM, Torrero V, Ferreiro I, Pérez D, Palao R, Martínez E, Llames S, Meana A, Holguín P OBJECTIVE: We report clinical and functional outcomes obtained after application of an autologous bioengineered composite skin (ABCS) produced in a single Spanish tissue-engineering unit. MATERIALS/METHODS: Twenty-five burned patients treated with ABCS from 1999 to 2007 in five burn centres were included in the study. Mean age was 29 years (SD 11), with mean total body surface area (TBSA) burned being 74% (SD 17) and mean full-thickness injury of 61% (SD 19) of TBSA. RESULTS: The mean area initially engrafted with ABCS was 24% (SD 13) of TBSA, with a final take of 49% (SD 30, range 0-100%). ABCS achieved permanent coverage of a mean of 11% (SD 8) of TBSA. In subset analyses, lack of pre- and post-application wound bed infection and lack of serious acute systemic complications at the time of engraftment were significantly associated with better ABCS take. CONCLUSIONS: Final take obtained with ABCS could be improved with the use of non-cytotoxic topical antibiotics following engraftment. The use of plasma to prepare ABCS reduces production costs: cost-effectiveness ratio is not a limitation for its use. In terms of patient satisfaction, cosmetic/functional outcomes (general appearance, texture, flexibility, sensitivity and colour) of ABCS and split-thickness autografts are not different statistically. PMID: 21255936 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Fabrication of gelatin-hyaluronic acid hybrid scaffolds with tunable porous structures for soft tissue engineering. Int J Biol Macromol. 2011 Jan 18; Authors: Zhang F, He C, Cao L, Feng W, Wang H, Mo X, Wang J The development of three-dimensional (3-D) scaffolds with highly open porous structure is one of the most important issues in tissue engineering. In this study, 3-D macroporous gelatin/hyaluronic acid (GE/HA) hybrid scaffolds with varying porous morphology were prepared by freeze-drying their blending solutions and subsequent chemical crosslinking by using 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). The resulting scaffolds were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Their swelling, in vitro degradation properties and compressive strength were also investigated. To evaluate in vitro cytocompatibility of scaffolds, mouse L929 fibroblasts were seeded onto the scaffolds for cell morphology and cell viability studies. It was found that the porous structure of scaffolds can be tailored by varying the ratios of gelatin to HA, both the swelling ratios and degradation rate increased with the increase of HA content in hybrid scaffolds, and crosslinking the scaffolds with EDC improved the degradation resistance of the scaffold in culture media and increased the mechanical strength of scaffolds. The in vitro results revealed that the prepared scaffolds do not induce cytotoxic effects and suitable for cell growth, especially in the case of scaffolds with higher gelatin content. The combined results of the physicochemical and biological studies suggested that the developed GE/HA hybrid scaffolds exhibit good potential and biocompatibility for soft tissue engineering applications. PMID: 21255605 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Homogeneous Chitosan/Poly(L-Lactide) Composite Scaffolds Prepared by Emulsion Freeze-Drying. J Biomater Sci Polym Ed. 2011 Jan 21; Authors: Niu X, Li X, Liu H, Zhou G, Feng Q, Cui F, Fan Y The combination between chitosan (CS)-based hydrophilic extracellular matrix polysaccharide and polylactide (PLA)-based hydrophobic biodegradable aliphatic polyester is a challenge in the biomaterials field. This study investigated the formation of homogeneous chitosan/poly(L-lactide) (CS/PLLA) porous composite scaffold using a novel emulsion freeze-drying technique. An oil-in-water (O/W) emulsification system was used in the presence of surfactant Tween-80, in which CS solution was used as the water phase and PLLA solution was used as the oil phase. The composite scaffolds showed well interconnected pore structures and homogenous distribution of CS and PLLA when the PLLA volume fraction was not higher than 50%. Once the PLLA content increased to 75%, SEM micrographs demonstrated that the two components present phase separation region. FT-IR analysis revealed that there are strong hydrogen bond interactions between CS and PLLA components. The porosity of the CS/PLLA composites was in the range of 85-90% and showed a slight decrease with increasing PLLA dose. The mechanical properties of the composites lay between that of the pure CS and the PLLA scaffold. The compressive strength increased from 0.17 to 0.21 MPa, while the compressive modulus increased from 2.37 to 3.38 MPa as the PLLA contents increased from 25 to 75%. In vitro cytotoxicity was evaluated by MTT assay. The results indicated that MC3T3-E1 cell viability and proliferation in the CS/PLLA scaffold were comparable to that in the CS scaffold, and much higher than that in the PLLA scaffold. The successful hydrophilic polysaccharide and hydrophobic polyester system offers a new delivery method of growth factors and a novel scaffold design for tissue engineering. PMID: 21255484 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Glutathione S-transferases as molecular markers of tumour progression and prognosis in renal cell carcinoma. Histopathology. 2011 Jan 24; Authors: Searchfield L, Price SA, Betton G, Jasani B, Riccardi D, Griffiths DF Searchfield L, Price S A, Betton G, Jasani B, Riccardi D & Griffiths D F R (2011) Histopathology Glutathione S-transferases as molecular markers of tumour progression and prognosis in renal cell carcinoma Aims: Renal cell carcinoma (RCC) often recurs as distant metastasis; there is thus a need for new indicators to identify high-risk patients. Glutathione S-transferases (GST)-α and -π are involved in the renal bioactivation of toxic metabolites. The aim was to investigate whether their expression is of diagnostic and prognostic value. Methods and results: Western blotting of microdissected normal kidney and immunostaining of histological RCC microarrays shows expression of GST-α in proximal tubular cells, while GST-π was found in the distal nephron. Of the primary 174 RCC cases examined, GST-α immunoreactivity was restricted to conventional RCC (n = 76, 68% positive) and was not seen in any other RCC subtypes. The cross-tabulation of the GST-α scores with other prognostic indices demonstrated that GST-α immunostaining was significantly more frequent in low-grade tumours (χ(2) : P < 0.004), and that conventional GST-α-positive RCC patients had a mean disease-free survival of 6.0 years (95% confidence interval 5.33-6.63), compared with 4.7 years (3.54-5.90) in GST-α-negative tumours (Kaplan-Meier survival analysis, P = 0.011, log-rank test). Conclusions: GST-α is a highly specific diagnostic marker for primary conventional RCC, where it is a prognostic marker if grade is omitted from the multivariate analysis. PMID: 21255063 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | A model for tissue engineering applications - femoral critical size defect in immunodeficient mice. Tissue Eng Part C Methods. 2011 Jan 21; Authors: Srouji S, Ben-David D, Müller R, Kohler T, Zussman E, Livne E Animal models for preclinical functionality assays lie midway between in vitro systems such as cell culture and actual clinical trials. We have developed a novel external fixation device for femoral critical size defect (CSD) in the femurs of immunodeficient mice as an experimental model for studying bone regeneration and bone tissue engineering. The external fixation device comprises four pointed rods and dental acrylic paste. A segmental bone defect (2 mm) was created in the midshaft of the mouse femur. The CSD in the femur of the mice were either left untreated or treated with a bone allograft, a cell-scaffold construct or a scaffold only construct. The repair and healing processes of the CSD were monitored by digital x-ray radiography, micro-computed tomography (μCT), and histology. Repair of the femoral CSD was achieved with the bone allografts, and partial repair of the femoral CSD was achieved with the cell-scaffold and with the scaffold only constructs. No repair of the non-grafted femoral CSD was observed. Our results establish the feasibility of this new mouse femoral model for critical size defect repair of segmental bone using a simple stabilized external fixation device. The model should prove especially useful for in vivo preclinical proof-of-concept studies that involve cell therapy-based technologies for bone tissue engineering applications in humans. PMID: 21254818 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Invasive three-dimensional organotypic neoplasia from multiple normal human epithelia. Nat Med. 2010 Dec;16(12):1450-5 Authors: Ridky TW, Chow JM, Wong DJ, Khavari PA Refined cancer models are required if researchers are to assess the burgeoning number of potential targets for cancer therapeutics in a clinically relevant context that allows a fast turnaround. Here we use tumor-associated genetic pathways to transform primary human epithelial cells from the epidermis, oropharynx, esophagus and cervix into genetically defined tumors in a human three-dimensional (3D) tissue environment that incorporates cell-populated stroma and intact basement membrane. These engineered organotypic tissues recapitulated natural features of tumor progression, including epithelial invasion through basement membrane, a complex process that is necessary for biological malignancy in 90% of human cancers. Invasion was rapid and was potentiated by stromal cells. Oncogenic signals in 3D tissue, but not 2D culture, resembled gene expression profiles from spontaneous human cancers. We screened 3D organotypic neoplasia with well-characterized signaling pathway inhibitors to distill a clinically faithful cancer gene signature. Multitissue 3D human tissue cancer models may provide an efficient and relevant complement to current approaches to characterizing cancer progression. PMID: 21102459 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Osteoinduction: translating preclinical promise into clinical reality. Br J Oral Maxillofac Surg. 2010 Oct;48(7):536-9 Authors: Ferretti C, Ripamonti U, Tsiridis E, Kerawala CJ, Mantalaris A, Heliotis M This review, the second in a series of three editorials, focuses on the problems of translating basic scientific research on induction of bone into reliable clinical applications. PMID: 20430492 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Generation of novel reporter stem cells and their application for molecular imaging of cardiac-differentiated stem cells in vivo. Stem Cells Dev. 2010 Sep;19(9):1437-48 Authors: Kammili RK, Taylor DG, Xia J, Osuala K, Thompson K, Menick DR, Ebert SN Stem cell therapies offer the potential for repair and regeneration of cardiac tissue. To facilitate evaluation of stem cell activity in vivo, we created novel dual-reporter mouse embryonic stem (mES) cell lines that express the firefly luciferase (LUC) reporter gene under the control of the cardiac sodium-calcium exchanger-1 (Ncx-1) promoter in the background of the 7AC5-EYFP mES cell line that constitutively expresses the enhanced yellow fluorescent protein (EYFP). We compared the ability of recombinant clonal cell lines to express LUC before and after induction of cardiac differentiation in vitro. In particular, one of the clonal cell lines (Ncx-1-43LUC mES cells) showed markedly enhanced LUC expression (45-fold increase) upon induction of cardiac differentiation in vitro. Further, cardiac differentiation in these cells was perpetuated over a period of 2-4 weeks after transplantation in a neonatal mouse heart model, as monitored by noninvasive bioluminescence imaging (BLI) and confirmed via postmortem immunofluorescence and histological assessments. In contrast, transplantation of undifferentiated pluripotent Ncx-1-43LUC mES cells in neonatal hearts did not result in detectable levels of cardiac differentiation in these cells in vivo. These results suggest that prior induction of cardiac differentiation in vitro enhances development and maintenance of a cardiomyocyte-like phenotype for mES cells following transplantation into neonatal mouse hearts in vivo. We conclude that the Ncx-1-43LUC mES cell line is a novel tool for monitoring early cardiac differentiation in vivo using noninvasive BLI. PMID: 20109065 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Chondrogenesis in a hyaluronic acid scaffold: comparison between chondrocytes and MSC from bone marrow and adipose tissue. Knee Surg Sports Traumatol Arthrosc. 2010 Oct;18(10):1407-16 Authors: Jakobsen RB, Shahdadfar A, Reinholt FP, Brinchmann JE Treatment of focal lesions of the articular cartilage of the knee using chondrocytes in a hyaluronic acid (HA) scaffold is already being investigated in clinical trials. An alternative may be to use mesenchymal stem cells (MSC). We have compared articular chondrocytes with MSC from human bone marrow (BM) and adipose tissue (AT), all cultured in HA scaffolds, for their ability to express genes and synthesize proteins associated with chondrogenesis. The cells were expanded in monolayer cultures. After seeding into the scaffold, the chondrocytes were maintained in medium, while the two MSC populations were given a chondrogenic differentiation medium. Chondrogenesis was assessed by real-time RT-PCR for chondrocyte-associated genes, by immunohistochemistry and by ELISA for collagens in the supernatant. Redifferentiation of the dedifferentiated chondrocytes in the HA scaffold was shown by a modest increase in type II collagen mRNA (COL2A1) and reduction in COL1A1. BM-MSC expressed 600-fold higher levels of COL2A1 than chondrocytes after 3 weeks in the scaffold. The levels of aggrecan (AGC1) and COL1A1 were similar for chondrocyte and BM-MSC scaffold cultures, while COL10A1 was higher in the BM-MSC. AT-MSC expressed levels of COL2A1 and COL1A1 similar to chondrocytes, but less AGC1 and COL10A1. Surprisingly, little collagen II protein was observed in the scaffold. Instead, collagen II was found in the culture medium. Chondrogenesis in HA scaffolds was more efficient using BM-MSC than AT-MSC or chondrocytes. Some of the secreted collagen II escaped entrapment in the extracellular space and was detected in the culture medium. PMID: 20020100 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Deubiquitylase HAUSP stabilizes REST and promotes maintenance of neural progenitor cells. Nat Cell Biol. 2011 Jan 23; Authors: Huang Z, Wu Q, Guryanova OA, Cheng L, Shou W, Rich JN, Bao S The repressor element 1-silencing transcription factor (REST) functions as a master regulator to maintain neural stem/progenitor cells (NPCs). REST undergoes proteasomal degradation through β-TrCP-mediated ubiquitylation during neuronal differentiation. However, reciprocal mechanisms that stabilize REST in NPCs are undefined. Here we show that the deubiquitylase HAUSP counterbalances REST ubiquitylation and prevents NPC differentiation. HAUSP expression declines concordantly with REST on neuronal differentiation and reciprocally with β-TrCP levels. HAUSP knockdown in NPCs decreases REST and induces differentiation. In contrast, HAUSP overexpression upregulates REST by overriding β-TrCP-mediated ubiquitylation. A consensus site (310-PYSS-313) in human REST is required for HAUSP-mediated REST deubiquitylation. Furthermore, REST overexpression in NPCs rescues the differentiation phenotype induced by HAUSP knockdown. These data demonstrate that HAUSP stabilizes REST through deubiquitylation and antagonizes β-TrCP in regulating REST at the post-translational level. Thus, HAUSP-mediated deubiquitylation represents a critical regulatory mechanism involved in the maintenance of NPCs. PMID: 21258371 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Review: Genetic manipulation of the rodent placenta. Placenta. 2011 Jan 21; Authors: Renaud SJ, Karim Rumi MA, Soares MJ The principal role of the placenta is the maintenance of pregnancy and promotion of fetal growth and viability. The use of transgenic rodents has greatly enhanced our understanding of placental development and function. However, embryonic lethality is often a confounding variable in determining whether a genetic modification adversely affected placental development. In these cases, it is beneficial to specifically manipulate the placental genome. The purpose of this review is to summarize available methodologies for specific genetic modification of the rodent placenta. By restricting genetic alterations to the trophoblast lineage, it is possible to gain a deeper understanding of placental development that perhaps will lead to gene-targeted therapies to rescue irregular placentation in transgenic animals or in women at high-risk for placenta-associated pregnancy complications. PMID: 21256588 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Simultaneous hybrid revascularization versus off-pump coronary artery bypass for multivessel coronary artery disease. Ann Thorac Surg. 2011 Feb;91(2):432-8 Authors: Hu S, Li Q, Gao P, Xiong H, Zheng Z, Li L, Xu B, Gao R This study sought to compare early and midterm clinical outcomes of a simultaneous hybrid coronary revascularization procedure with those in a propensity-matched subset of patients undergoing conventional off-pump coronary artery bypass grafting. PMID: 21256284 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Building bone from blood vessels. Nat Med. 2010 Dec;16(12):1373-4 Authors: Horwitz EM PMID: 21135844 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Conversion of vascular endothelial cells into multipotent stem-like cells. Nat Med. 2010 Dec;16(12):1400-6 Authors: Medici D, Shore EM, Lounev VY, Kaplan FS, Kalluri R, Olsen BR Mesenchymal stem cells can give rise to several cell types, but varying results depending on isolation methods and tissue source have led to controversies about their usefulness in clinical medicine. Here we show that vascular endothelial cells can transform into multipotent stem-like cells by an activin-like kinase-2 (ALK2) receptor-dependent mechanism. In lesions from individuals with fibrodysplasia ossificans progressiva (FOP), a disease in which heterotopic ossification occurs as a result of activating ALK2 mutations, or from transgenic mice expressing constitutively active ALK2, chondrocytes and osteoblasts expressed endothelial markers. Lineage tracing of heterotopic ossification in mice using a Tie2-Cre construct also suggested an endothelial origin of these cell types. Expression of constitutively active ALK2 in endothelial cells caused endothelial-to-mesenchymal transition and acquisition of a stem cell-like phenotype. Similar results were obtained by treatment of untransfected endothelial cells with the ligands transforming growth factor-β2 (TGF-β2) or bone morphogenetic protein-4 (BMP4) in an ALK2-dependent manner. These stem-like cells could be triggered to differentiate into osteoblasts, chondrocytes or adipocytes. We suggest that conversion of endothelial cells to stem-like cells may provide a new approach to tissue engineering. PMID: 21102460 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | The emergence of cellular therapy: impact on transfusion medicine. Transfusion. 2010 Nov;50(11):2301-9 Authors: Snyder E, Choate J PMID: 20819189 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Blood sphingolipidomics in healthy humans: impact of sample collection methodology. J Lipid Res. 2010 Oct;51(10):3074-87 Authors: Hammad SM, Pierce JS, Soodavar F, Smith KJ, Al Gadban MM, Rembiesa B, Klein RL, Hannun YA, Bielawski J, Bielawska A We used a HPLC-MS/MS methodology for determination of a basic metabolomic profile (18:1,18:0 sphingoid backbone, C(14)-C(26) N-acyl part) of "normal" sphingolipid levels in human serum and plasma. Blood was collected from healthy males and nonpregnant females under fasting and nonfasting conditions with and without anticoagulants. Sphingolipids analyzed included sphingoid bases, sphingosine and dihydrosphingosine, their 1-phosphates (S1P and dhS1P), molecular species (C(n)-) of ceramide (Cer), sphingomyelin (SM), hexosylceramide (HexCer), lactosylceramide (LacCer), and Cer 1-phosphate (Cer1P). SM, LacCer, HexCer, Cer, and Cer1P constituted 87.7, 5.8, 3.4, 2.8, and 0.15% of total sphingolipids, respectively. The abundant circulating SM was C(16)-SM (64.0 µM), and it increased with fasting (100 µM). The abundant LacCer was C(16)-LacCer (10.0 µM) and the abundant HexCer was C(24)-HexCer (2.5 µM). The abundant Cer, C(24)-Cer (4.0 µM), was not influenced by fasting; however, levels of C(16)-C(20) Cers were decreased in response to fasting. S1P levels were higher in serum than plasma (0.68 µM vs. 0.32 µM). We also determined levels of sphingoid bases and SM species in isolated lipoprotein classes. HDL(3) was the major carrier of S1P, dhS1P, and Sph, and LDL was the major carrier of Cer and dhSph. Per particle, VLDL contained the highest levels of SM, Cer, and S1P. HPLC-MS/MS should provide a tool for clinical testing of circulating bioactive sphingolipids in human blood. PMID: 20660127 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Ca2+ and cAMP signaling in human embryonic stem cell-derived dopamine neurons. Stem Cells Dev. 2010 Sep;19(9):1355-64 Authors: Malmersjö S, Liste I, Dyachok O, Tengholm A, Arenas E, Uhlén P Human embryonic stem (hES) cell differentiation into dopamine neurons is considered a promising strategy for cell replacement therapy in Parkinson's disease, yet the functional properties of hES cell-derived dopamine neurons remain poorly defined. The objective of this study was to characterize intracellular calcium (Ca(2+)) and sub-plasma membrane cyclic AMP-signaling properties in hES cell-derived dopamine neurons. We found that hES cell-derived dopamine neurons and neural progenitors raised Ca(2+) from intra- and extracellular compartments in response to depolarization, glutamate, ATP, and dopamine D(2) receptor activation, while undifferentiated hES cells only mobilized Ca(2+) from intracellular stores in response to ATP and D(2) receptor-induced activation. Interestingly, we also found that hES cell-derived dopamine neurons in addition to primary ventral midbrain dopamine neurons were more prone to release Ca(2+) from intracellular stores than non-dopamine neurons following treatment with the neuropeptide neurotensin. Furthermore, hES cell-derived dopamine neurons showed cAMP elevations in response to forskolin and 3-isobutyl-methylxanthine, similar to primary dopamine neurons. Taken together, these results unravel the temporal sequence by which hES cells acquire Ca(2+) and cAMP signaling competence during dopamine differentiation. PMID: 20043754 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Association between serum high-molecular-weight adiponectin level and the severity of chronic graft-versus-host disease in allogeneic stem cell transplantation recipients. Blood. 2011 Jan 21; Authors: Nakasone H, Binh PN, Yamazaki R, Tanaka Y, Sakamoto K, Ashizawa M, Sato M, Terasako K, Kimura SI, Kikuchi M, Kako S, Okuda S, Oshima K, Tanihara A, Nishida J, Abe Y, Kanda Y Recently, a growing body of evidence has suggested that adiponectin, which is secreted by adipose tissues, plays a critical role in obesity-related and autoimmune diseases. We compared the concentrations of adiponectin among 26 normal subjects and 34 allogeneic stem cell transplantation recipients. The concentrations of adiponectin were significantly higher in recipients with cGVHD than those in subjects without cGVHD (21.7±11.0 vs 9.1±6.1 µg/ml in females (P<0.001), and 10.1±6.8 vs 4.3±2.9 µg/ml in males (P=0.003)). Multivariate analysis revealed that a higher concentration of adiponectin was associated with female gender (β-coefficient 8.2, P<0.0001) and the severity of cGVHD (β-coefficient 6.6, 12.7, and 15.6, P <0.01, each for mild, moderate, and severe cGVHD, respectively). In addition, adiponectin levels increased as cGVHD progressed, decreased as cGVHD improved, and did not change with stable cGVHD. In conclusion, adiponectin was associated with the severity of cGVHD, and might play a role in the pathophysiology of cGVHD. PMID: 21258011 [PubMed - as supplied by publisher] | | | | | | | | | |  | |  | |  |
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