Human umbilical cord is easy to obtain because it is discarded after birth, so that ethical issues can be avoided. Chondrogenesis studies using MSCs from bone marrow, cord blood, and adipose have indicated that TGFβ3 and BMP6 stimulate chondrogenesis. Therefore, we investigated chondrogenesis of hUC-MSCs on TGFβ3, BMP6, and combination of the two growth factors. We initiated chondrogenesis of cells by application of physical forces to form 3D cell clusters. After initiation, we designated four experimental groups for differentiation of cells, as follows: control, 10 ng/mL TGFβ3, 100 ng/mL BMP6, and the combination of 5 ng/mL TGFβ3 and 50 ng/mL BMP6. For analysis of chondrogenesis, GAG contents, mRNA expression, histological analysis and immunohistochemistry (IHC) were performed. For analysis of GAG contents, GAG assay was performed and RT-PCR was performed for determination of chondrogenic markers. Histological analysis was performed through safranin O, alcian blue, and IHC was performed using collagen type I and II. GAG contents were increased 184% by TGFβ3, 147% by BMP6, and 189% by the combination of TGFβ3 and BMP6, compared to control. The growth factors improved collagen II and aggrecan expression; in particular, TGFβ3 and BMP6 showed a synergistic effect, compared to only TGFβ3 or BMP6 treated. The results of histological and IHC analysis indicated that chondrogenic differentiation in TGFβ3 and the combination of TGFβ3 and BMP6 showed more cartilage deposition. In conclusion, TGFβ3 and BMP6 differentiated hUC-MSCs into chondrogenic clusters of the combination treatment of the two growth factors showed more efficient chondrogenic ability.

Transforming growth factor-β (TGF-β) has been shown to have a positive effect on in vitro fertilization (IVF) and has been reported to stimulate meiosis at follicular level in variety of species. The study was designed to determine the expression patterns of TGF-β1, TGF-β receptors type Ⅰ, Ⅱ and Smads gene in bovine oocytes and embryos. TGF-β1 and their receptors were observed in the unfertilized oocytes. TGF-β1 and type Ⅱ receptor were not expressed at the blastocyst stage, however, only type I receptor was exclusively observed at the same stage. The blastocyst stage, in particular, showed high levels of mRNA expression patterns containing a TGF-β type Ⅰ receptor. The mRNA expression pattern of Smad 2 at all stages of embryonic development was similar in all respect with TGF-β1 type I receptor. On the contrary, Smad 3 and 4 were expressed with high and low level mRNA at the blastocyst stage. In conclusion, it is suggested that TGF-β signaling may be regarded as an important entity during the preimplantation embryo development.

Transforming growth factor (TGF) family is well known to induce the chondrogenic differentiation of mesenchymal stem cells (MSC). However, the precise signal transduction pathways and underlying factors are not well known. Thus the present study aims to evaluate the possible role of C2 domain in the chondrogenic differentiation of human mesenchymal stem cells. To this end, 145 C2 domains in the adenovirus were individually transfected to hMSC, and morphological changes were examined. Among 145 C2 domains, C2 domain of protein kinase C eta (PKCη) was selected as a possible chondrogenic differentiation factor for hMSC. To confirm this possibility, we treated TGFβ3, a well known chondrogenic differentiation factor of hMSC, and examined the increased-expression of glycosaminoglycan (GAG), collagen type II (COL II) as well as PKCη using PT-PCR, immunocytochemistry and Western blot analysis. To further evaluation of C2 domain of PKCη, we examined morphological changes, expressions of GAG and COL II after transfection of PKCη -C2 domain in hMSC. Overexpression of PKCη-C2 domain induced morphological change and increased GAG and COL II expressions. The present results demonstrate that PKCη involves in the TGF-β3-induced chondrogenic differentiation of hMSC, and C2 domain of PKCη has important role in this process.