Acute and temporal expression of tumor necrosis factor (TNF)-α-stimulated gene 6 product, TSG6, in mesenchymal stem cells creates microenvironments required for their successful transplantation into muscle tissue.

Previously, we demonstrated that when mesenchymal stem cells (MSCs) from mouse ES cells were transplanted into skeletal muscle, more than 60% of them differentiated into muscles in the crush-injured tibialis anterior muscle in vivo, although MSCs neither differentiated nor settled in the intact muscle. Microenvironments, including the extracellular matrix between the injured and intact muscle, were quite different. In the injured muscle, hyaluronan (HA), heavy chains of inter-α-inhibitor (IαI), CD44, and TNF-α-stimulated gene 6 product (TSG-6) increased 24-48 h after injury, although basement membrane components of differentiated muscle such as perlecan, laminin, and type IV collagen increased gradually 4 days after the crush. We then investigated the microenvironments crucial for cell transplantation, using the lysate of C2C12 myotubules for mimicking injured circumstances in vivo. MSCs settled in the intact muscle when they were transplanted together with the C2C12 lysate or TSG6. MSCs produced and released TSG6 when they were cultured with C2C12 lysates in vitro. MSCs pretreated with the lysate also settled in the intact muscle. Furthermore, MSCs whose TSG6 was knocked down by shRNA, even if transplanted or pretreated with the lysate, could not settle in the muscle. Immunofluorescent staining showed that HA and IαI always co-localized or were distributed closely, suggesting formation of covalent complexes, i.e. the SHAP-HA complex in the presence of TSG6. Thus, TSG6, HA, and IαI were crucial factors for the settlement and probably the subsequent differentiation of MSCs.

Sesamin Attenuates VEGFA-Induced Angiogenesis via Inhibition of Src and FAK Signaling in Chick Chorioallantoic Membrane Model and Human Endothelial EA.hy926 Cells.

Sesamin, a major phytochemical in sesame seeds and oil, has been reported to have effects on physiological and pathological angiogenesis in several studies. Nevertheless, the underlying mechanisms of sesamin's effect on angiogenesis are not understood well enough. This study aimed to investigate its effect on both physiological and pathological angiogenesis using the in vivo chick chorioallantoic membrane (CAM) model and the in vitro human endothelial cell line, EA.hy926, model. Sesamin inhibited the VEGFA-induced pathological angiogenesis significantly, although no effect was seen on angiogenesis without induction. It reduced the formation of vascular branches in the VEGFA-treated CAMs and also the proliferation and migration of EA.hy926 endothelial cells induced by VEGFA. Sesamin impeded the VEGF-mediated activation of Src and FAK signaling proteins, which may be responsible for sesamin-mediated reduction of pathological angiogenesis. Moreover, the effect of sesamin on the expressions of angiogenesis-related genes was then investigated and it was found that both mRNA and protein expressions of Notch1, the key pathway in vascular development, induced by VEGFA, were significantly reduced by sesamin. Our results altogether suggested that sesamin, by inhibiting pathological angiogenesis, has the potential to be employed in the prevention or treatment of diseases with over-angiogenesis, such as cancers.

Sesamin stimulates osteoblast differentiation through p38 and ERK1/2 MAPK signaling pathways.

BACKGROUND: Osteoporosis is a worldwide health problem predominantly affecting post-menopausal women. Therapies aimed at increasing bone mass in osteoporetic patients lag behind comparable investigation of therapeutic strategies focusing on the bone resorption process. Sesamin, a major lignan compound found in Sesamun indicum Linn., has a variety of pharmacological effects, though its activity on bone cell function is unclear. Herein we examine the effect of this lignan on osteoblast differentiation and function. METHOD: Cell cytotoxicity and proliferative in hFOB1.19 were examined by MTT and alamar blue assay up to 96 h of treatment. Gene expression of COL1, ALP, BMP-2, Runx2, OC, RANKL and OPG were detected after 24 h of sesamin treatment. ALP activity was measured at day 7, 14 and 21 of cultured. For mineralized assay, ADSCs were cultured in the presence of osteogenic media supplement with or without sesamin for 21 days and then stained with Alizarin Red S. MAPK signaling pathway activation was observed by using western blotting. RESULTS: Sesamin promoted the gene expression of COL1, ALP, OCN, BMP-2 and Runx2 in hFOB1.19. On the other hand, sesamin was able to up-regulate OPG and down-regulate RANKL gene expression. ALP activity also significantly increased after sesamin treatment. Interestingly, sesamin induced formation of mineralized nodules in adipose derived stem cells (ADSCs) as observed by Alizarin Red S staining; this implies that sesamin has anabolic effects both on progenitor and committed cell stages of osteoblasts. Western blotting data showed that sesamin activated phosphorylation of p38 and ERK1/2 in hFOB1.19. CONCLUSIONS: The data suggest that sesamin has the ability to trigger osteoblast differentiation by activation of the p38 and ERK MAPK signaling pathway and possibly indirectly regulate osteoclast development via the expression of OPG and RANKL in osteoblasts. Therefore, sesamin may be a promising phytochemical that could be developed for supplementation of osteoporotic therapy.

Fish Collagen Hydrolysates Modulate Cartilage Metabolism.

Osteoarthritis is a degenerative joint disease in which interleukin-1ß plays a major role in the inflammatory process. Administration of collagen hydrolysate was an optional treatment of osteoarthritis. Fish has become an interesting source of collagen hydrolysate because of religious reason and there is no risk from mad cow disease. However, the effects of different sizes of fish collagen hydrolysate on cartilage and chondrocyte metabolism have not been well studied yet. This study examined the effect of different sizes of fish collagen hydrolysate on cartilage metabolism. Three different sizes of fish collagen hydrolysate were prepared by size exclusion using centrifugation, which composed of small fraction (<3 kDa), medium fraction (3-10 kDa) and large fraction (>10 kDa). Using porcine cartilage explant, in physiological condition, all the three fractions had no effect on cartilage metabolism, but they could induce pro-MMP3 and pro-MMP13 secretions through activation of p-ERK and p-p38. In pathological condition induced by interleukin-1ß and oncostatin-M, small and medium fractions showed additive effect with interleukin-1ß and oncostatin-M on cartilage degradation, whereas large size had no effect. In addition, the effect of small size occurred through further activation of p-p65, which resulted in further induction of active-MMP13, while medium size had a different mechanism. In conclusion, all three fractions fish collagen hydrolysate had no effect on cartilage metabolism in physiological condition, but small and medium fractions had adverse effect on cartilage in pathological condition. Taken together, various sizes of fish collagen hydrolysate showed different effects on cartilage metabolism. Therefore, different sizes of fish collagen hydrolysates play different roles on cartilage metabolism, especially in the pathological condition.

Inhibitory effects of sesamin on human osteoclastogenesis.

The promotional nature of sesamin on human osteoblast differentiation has been proven. Here, the effect of sesamin on human osteoclasts was investigated in terms of differentiation and function in M-CSF and RANKL induced human PBMCs. Sesamin treatment significantly decreased the number of differentiated osteoclasts observed by TRAP staining; however, sesamin inhibition did not result from the alteration of precursor cell proliferation. Sesamin did not decrease NFATc1 gene expression, which opposed the decreasing trend of CathK and TRAP expression. DC-STAMP, but not Atp6v0d2, also significantly decreased in the presence of 14 µM sesamin. Expressions of CCR2b and CCR4 as chemokine receptors were significantly down-regulated. Sesamin might mediate the inhibition of human osteoclast differentiation, the recruitment of precursor cells and F-actin formation. Decrease in the area of the resorption pits and the collagen released from the bone slices under sesamin treatment emphasized the inhibitory effects on both the differentiation and function of osteoclasts. Sesamin is a promising phytochemical agent inhibiting osteoclast differentiation and function.