|  |  |  | | | | | TE-RegenMed-StemCell feed | | | | | | | | | | | | | | | | | | | The "Nature Medicine" item on Jan. 14, 2011, incorrectly said that Alan Bernstein, according to Nature Medicine, was not necessarily off the table as a candidate for president of CIRM. The article should have said he was not off the table as a candidate for chairman of CIRM. | | | | | | | | | | | | | | | | | | | | | | | | | Culture and identification of human amniotic mesenchymal stem cells. Chin Med Sci J. 2010 Dec;25(4):211-4 Authors: Shuang-Zhi H, Ping S, Xi-Ning P Objective To establish the method of isolation, purification, and identification of human amniotic mesenchymal stem cells (hAMSCs). Methods hAMSCs were isolated from human amniotic membrane by trypsin-collagenase digestion, and cultured in Dulbecco’s modified Eagle’s medinm/F12 medium supplemented with 10% fetal bovine serum. Phenotypic characteristics of these cells were analyzed by means of immunocytochemistry and flow cytometry. Results The cells successfully isolated from human amniotic membrane expressed representative mesenchymal cell surface markers CD44, CD90, and vimentin, but not CD45. Conclusions This study establishes a potential method for isolation of hAMSCs from human amnion,in vitro culture, and identification. The isolated cells show phenotypic characteristics of mesenchymal stem cells. PMID: 21232180 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Transcriptional activation of the anchoring protein SAP97 by heat shock factor (HSF)-1 stabilizes K(v) 1.5 channels in HL-1 cells. Br J Pharmacol. 2011 Jan 14; Authors: Ting Y, Morikawa K, Kurata Y, Li P, Bahrudin U, Mizuta E, Kato M, Miake J, Yamamoto Y, Yoshida A, Murata M, Inoue T, Nakai A, Shiota G, Higaki K, Nanba E, Ninomiya H, Shirayoshi Y, Hisatome I BACKGROUND AND PURPOSE The expression of voltage-dependent K(+) channels (K(v) ) 1.5 is regulated by members of the heat shock protein (Hsp) family. We examined whether the heat shock transcription factor 1 (HSF-1) and its inducer geranylgeranylacetone (GGA) could affect the expression of K(v) 1.5 channels and its anchoring protein, synapse associated protein 97 (SAP97). EXPERIMENTAL APPROACH Transfected mouse atrial cardiomyocytes (HL-1 cells) and COS7 cells were subjected to luciferase reporter gene assay and whole-cell patch clamp. Protein and mRNA extracts were subjected to Western blot and quantitative real-time PCR. KEY RESULTS Heat shock of HL-1 cells induced expression of Hsp70, HSF-1, SAP97 and K(v) 1.5 proteins. These effects were reproduced by wild-type HSF-1. Both heat shock and expression of HSF-1, but not the R71G mutant, increased the SAP97 mRNA level. siRNA against SAP97 abolished HSF-1-induced increase of K(v) 1.5 and SAP97 proteins. A luciferase reporter gene assay revealed that the SAP97 promoter region (from -919 to -740) that contains heat shock elements (HSEs) was required for this induction. Suppression of SIRT1 function either by nicotinamide or siRNA decreased the level of SAP97 mRNA. SIRT1 activation by resveratrol had opposing effects. A treatment of the cells with GGA increased the level of SAP97 mRNA, K(v) 1.5 proteins and I(Kur) current which could be modified with either resveratrol or nicotinamide. CONCLUSIONS AND IMPLICATIONS HSF-1 induced transcription of SAP97 through SIRT1-dependent interaction with HSEs; the increase in SAP97 resulted in stabilization of K(v) 1.5 channels. These effects were mimicked by GGA. PMID: 21232033 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Bacterial flavohemoglobin: a molecular tool to probe mammalian nitric oxide biology. Biotechniques. 2011 Jan;50(1):41-5 Authors: Forrester M, Eyler C, Rich J A wide range of mammalian signaling and stress pathways are mediated by nitric oxide (NO), which is synthesized in vivo by the nitric oxide synthase (NOS) family of enzymes. Experimental manipulations of NO are frequently achieved by either inhibition or activation of endogenous NOS or via providing exogenous NO sources. On the contrary, many microbes consume NO via flavohemoglobin (FlavoHb), a highly efficient NO-dioxygenase that protects from nitrosative stress. Here we report a novel resource for studying NO in mammalian cells by heterologously expressing Escherichia coli FlavoHb within a lentiviral delivery system. This technique boosts endogenous cellular consumption of NO, thus providing a simple and efficacious approach to studying mammalian NO biology that can be employed as both a primary experimental and confirmatory tool. Address correspondence to Michael T. Forrester, Department of Biochemistry, Medical Scientist Training Program, Box 102005, Duke University Medical Center, Durham, NC, 27710, USA. e-mail: , or Jeremy N. Rich, Department of Stem Cell Biology and Regenerative Medicine, Mail Code NE30, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA. e-mail: PMID: 21231921 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Manganese superoxide dismutase expression in endothelial progenitor cells accelerates wound healing in diabetic mice. J Clin Invest. 2010 Dec 1;120(12):4207-19 Authors: Marrotte EJ, Chen DD, Hakim JS, Chen AF Amputation as a result of impaired wound healing is a serious complication of diabetes. Inadequate angiogenesis contributes to poor wound healing in diabetic patients. Endothelial progenitor cells (EPCs) normally augment angiogenesis and wound repair but are functionally impaired in diabetics. Here we report that decreased expression of manganese superoxide dismutase (MnSOD) in EPCs contributes to impaired would healing in a mouse model of type 2 diabetes. A decreased frequency of circulating EPCs was detected in type 2 diabetic (db/db) mice, and when isolated, these cells exhibited decreased expression and activity of MnSOD. Wound healing and angiogenesis were markedly delayed in diabetic mice compared with normal controls. For cell therapy, topical transplantation of EPCs onto excisional wounds in diabetic mice demonstrated that diabetic EPCs were less effective than normal EPCs at accelerating wound closure. Transplantation of diabetic EPCs after MnSOD gene therapy restored their ability to mediate angiogenesis and wound repair. Conversely, siRNA-mediated knockdown of MnSOD in normal EPCs reduced their activity in diabetic wound healing assays. Increasing the number of transplanted diabetic EPCs also improved the rate of wound closure. Our findings demonstrate that cell therapy using diabetic EPCs after ex vivo MnSOD gene transfer accelerates their ability to heal wounds in a mouse model of type 2 diabetes. PMID: 21060152 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Nano-Fibrous Tissue Engineering Scaffolds Capable of Growth Factor Delivery. Pharm Res. 2011 Jan 14; Authors: Hu J, Ma PX Tissue engineering aims at constructing biological substitutes to repair damaged tissues. Three-dimensional (3D) porous scaffolds are commonly utilized to define the 3D geometry of tissue engineering constructs and provide adequate pore space and surface to support cell attachment, migration, proliferation, differentiation and neo tissue genesis. Biomimetic 3D scaffolds provide synthetic microenvironments that mimic the natural regeneration microenvironments and promote tissue regeneration process. While nano-fibrous (NF) scaffolds are constructed to mimic the architecture of NF extracellular matrix, controlled-release growth factors are incorporated to modulate the regeneration process. The present article summarizes current advances in methods to fabricate NF polymer scaffolds and the technologies to incorporate controlled growth factor delivery systems into 3D scaffolds, followed by examples of accelerated regeneration when the scaffolds with growth factor releasing capacity are applied in animal models. PMID: 21234657 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Regeneration of scull bones in adult rabbits after implantation of commercial osteoinductive materials and transplantation of a tissue-engineering construct. Bull Exp Biol Med. 2010 Apr;149(4):505-10 Authors: Volkov AV, Alekseeva IS, Kulakov AA, Gol'dshtein DV, Shustrov SA, Shuraev AI, Arutyunyan IV, Bukharova TB, Rzhaninova AA, Bol'shakova GB, Grigor'yan AS We performed a comparative study of reparative osteogenesis in rabbits with experimental critical defects of the parietal bones after implantation of commercial osteoinductive materials "Biomatrix", "Osteomatrix", "BioOss" in combination with platelet-rich plasma and transplantation of a tissue-engineering construct on the basis of autogenic multipotent stromal cells from the adipose tissue predifferentiated in osteogenic direction. It was found that experimental reparative osteogenesis is insufficiently stimulated by implantation materials and full-thickness trepanation holes were not completely closed. After transplantation of the studied tissue-engineering construct, the defect was filled with full-length bone regenerate (in the center of the regenerate and from the maternal bone) in contrast to control and reference groups, where the bone tissue was formed only on the side of the maternal bone. On day 120 after transplantation of the tissue-engineering construct, the percent of newly-formed bone tissue in the regenerate was 24% (the total percent of bone tissue in the regenerate was 39%), which attested to active incomplete regenerative process in contrast to control and reference groups. Thus, the study demonstrated effective regeneration of the critical defects of the parietal bones in rabbits 120 days after transplantation of the tissue-engineering construct in contrast to commercial osteoplastic materials for directed bone regeneration. PMID: 21234453 [PubMed - in process] | | | | | | | | | | | | | | | | | | | | | | | | | Resorbable Elastomeric Networks Prepared by Photocrosslinking of High Molecular Weight Poly(trimethylene carbonate) with Photoinitiators and Poly(trimethylene carbonate) Macromers as Crosslinking Aids. Acta Biomater. 2011 Jan 10; Authors: Bat E, Kooten TG, Feijen J, Grijpma DW Resorbable and elastomeric poly(trimethylene carbonate) (PTMC) networks were efficiently prepared by photoinitiated crosslinking of linear high molecular weight PTMC. To crosslink PTMC films, low molecular weight PTMC macromers with methacrylate endgroups were synthesized and used as crosslinking aids. By exposing PTMC films containing only photoinitiator (Irgacure® 2959) or both photoinitiator and PTMC macromers to ultraviolet light, PTMC networks with high gel contents (87-95%) could be obtained. The crosslink density could readily be varied by adjusting the irradiation time or the amount of crosslinking aid used. The formed networks were flexible with low elastic modulus values ranging from 7.1 to 7.5 MPa, and also showed excellent resistance to creep in cyclic tests. In vitro experiments showed that the photocrosslinked PTMC networks could be eroded by macrophages, and upon incubation in aqueous cholesterol esterase enzyme- or potassium dioxide solutions. The rate of surface erosion of photocrosslinked PTMC networks was significantly lower than that observed for films prepared from linear PTMC. These resorbable PTMC elastomeric networks are compatible with cells and may find application in tissue engineering and controlled release. PMID: 21232640 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | Gradient biomaterials for soft-to-hard interface tissue engineering. Acta Biomater. 2011 Jan 10; Authors: Seidi A, Ramalingam M, Elloumi-Hannachi I, Ostrovidov S, Khademhosseini A Interface tissue engineering (ITE) is a rapidly developing field that aims to fabricate biological tissue alternates with the goal of repairing or regenerating the functions of diseased or damaged zones at the interface of different tissue types (also called "interface tissues"). Notable examples of the interface tissues in the human body include ligament-to-bone, tendon-to-bone, and cartilage-to-bone. Engineering interface tissues is a complex process, which requires a combination of specialized biomaterials with spatially organized material composition, cell types, and signaling molecules. Therefore, the use of conventional biomaterials (monophasic or composites) for ITE has certain limitations to help stimulate the tissue integration, or re-creating the structural organization at the junction of different tissue types. The advancement of micro- and nanotechnologies enable us to develop biomaterial systems with gradient in material composition and properties that encourage the differentiation of multiple cell phenotypes and subsequent tissue development. In this review we discuss recent developments in the fabrication of gradient biomaterials for controlling cellular behavior such as migration, differentiation, and heterotypic interactions. Moreover, we give an overview of potential uses of gradient materials in engineering interface tissues such as soft tissues (e.g. cartilage) to hard tissues (e.g. bone), with illustrated experimental examples. We finally also address fundamentals of interface tissue organization, various gradient biomaterials used in ITE, micro- and nanotechnologies employed for the fabrication of those gradients, and certain challenges that must be met in order for ITE to reach its full potential. PMID: 21232635 [PubMed - as supplied by publisher] | | | | | | | | | | | | | | | | | | | | | | | | | [Personalized medicine and individual healthcare : Medical and information technology aspects]. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz. 2010 Aug;53(8):776-82 Authors: Niederlag W, Lemke HU, Rienhoff O The individualization of medicine and healthcare appears to be following a general societal trend. The terms "personalized medicine" and "personal health" are used to describe this process. Here it must be emphasized that personalized medicine is not limited to pharmacogenomics, but that the spectrum of personalized medicine is much broader. Applications range from individualized diagnostics, patient-specific pharmacological therapy, therapy with individual prostheses and implants to therapy approaches using autologous cells, and from patient model-based therapy in the operating room, electronic patient records through to the individual care of patients in their home environment with the use of technical systems and services. Although in some areas practical solutions have already been found, most applications will not be fully developed for many years to come. Medical and information technology are essential to personalized medicine and personal health, each driving the other forward. PMID: 20700776 [PubMed - indexed for MEDLINE] | | | | | | | | | | | | | | | | | | | | | | | | | Viscoelastic characteristics of contracted collagen gels populated with rat fibroblasts or cardiomyocytes. J Artif Organs. 2010 Sep;13(3):139-44 Authors: Feng Z, Seya D, Kitajima T, Kosawada T, Nakamura T, Umezu M The viscoelastic characteristics of contracted collagen gels populated with rat fibroblasts or cardiomyocytes were investigated by uniaxial tensile testing. Rat type I collagen-Dulbecco's modified Eagle's medium solution (each 2 ml in volume, 0.5 mg/ml collagen concentration) containing 2.0 million rat fibroblasts or cardiomyocytes were cast in a circular shape. After gelation and culture for 10 days the contracted gels were first stretched to a tensile strain of approximately 0.20 at 4.6 × 10(-3)/s strain rate, and then the strain was kept unchanged for 3 min. The tensile stress in the gels was recorded. The results were regressed against the equations of the Kelvin viscoelastic model. It was found that the two elastic coefficients in the model were 6.5 ± 1.7 and 10.2 ± 3.2 kPa, respectively, for gels with cardiomyocytes and 5.1 ± 1.6 and 4.5 ± 0.9 kPa for those with fibroblasts; the values for gels with cardiomyocytes were significantly higher than those for gels with fibroblasts. The viscous coefficient was 169.6 ± 60.7 kPa s for the cardiomyocytes and 143.6 ± 44.7 kPa s for the fibroblasts. The relaxation time constant for gels with cardiomyocytes was 19.6 ± 10.6 s, significantly smaller than for gels with fibroblasts (36.4 ± 13.3 s). This study is the first to obtain viscoelastic data for living cell-contracted collagen gels. These data show that the viscous effect has a vital effect on the mechanical behavior of the gels and cannot be neglected in the culture and function of artificial substitutes based on contracted collagen gels. Furthermore, the data may imply that viscous coefficient of the gels might be closely related to collagen density rather than to cross linking among collagen fibrils. PMID: 20614226 [PubMed - indexed for MEDLINE] | | | | | | | | | |  | |  | |  |
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