Molecular mechanism of hypoxia-induced chondrogenesis and its application in in vivo cartilage tissue engineering.

Cartilage engineering is one of the most challenging issue in regenerative medicine, due to its limited self-ability to repair. Here, we assessed engineering of cartilage tissue starting from human bone marrow (hBM) stem cells under hypoxic environment and delineated the mechanism whereby chondrogenesis could be conducted without addition of exogenous growth factors. hBM stem cells were cultured in alginate beads and chondrogenesis was monitored by chondrocyte phenotypic markers.

Characterization of distinct mesenchymal-like cell populations from human skeletal muscle in situ and in vitro.

Human skeletal muscle is an essential source of various cellular progenitors with potential therapeutic perspectives. We first used extracellular markers to identify in situ the main cell types located in a satellite position or in the endomysium of the skeletal muscle. Immunohistology revealed labeling of cells by markers of mesenchymal (CD13, CD29, CD44, CD47, CD49, CD62, CD73, CD90, CD105, CD146, and CD15 in this study), myogenic (CD56), angiogenic (CD31, CD34, CD106, CD146), hematopoietic (CD10, CD15, CD34) lineages.

Interleukin-1 and transforming growth factor-beta 1 as crucial factors in osteoarthritic cartilage metabolism.

In osteoarthritis (OA), interleukin-1 (IL-1) stimulates the expression of metalloproteinases and aggrecanases, which induce cartilage degradation. IL-1 is also capable of reducing the production of cartilage-specific macromolecules, including type II collagen, through modulation of the transcription factors Sp1 and Sp3. Conversely, Transforming growth factor-beta (TGF-beta) counteracts with most of the IL-1 deleterious effects and contributes to cartilage homeostasis.

Differentiation potential of human muscle-derived cells towards chondrogenic phenotype in alginate beads culture.

Objective: The aim of this study was to evaluate the differentiation potential of two populations of muscle-derived cells (CD56- and CD56+) towards chondrogenic phenotype in alginate beads culture and to compare the effect of transforming growth factor beta 1 (TGFbeta1) on the differentiation process in these populations.

Methods: Muscle CD56- and CD56+ cells were cultured in alginate beads, in a chondrogenic medium, containing or not TGFbeta1 (10 ng/ml). Cultures were maintained for 3, 7, 14 or 21 days in a humidified culture incubator.

Hypoxia affects mesenchymal stromal cell osteogenic differentiation and angiogenic factor expression.

Mesenchymal stromal cells (MSCs) seeded onto biocompatible scaffolds have been proposed for repairing bone defects. When transplanted in vivo, MSCs (expanded in vitro in 21% O(2)) undergo temporary oxygen deprivation due to the lack of pre-existing blood vessels within these scaffolds. In the present study, the effects of temporary (48 h) exposure to hypoxia ( View Article and Find Full Text PDF