Mesenchymal stem cells (MSCs) derived exosomes have been shown to have protective effects on the kidney in ischemia/reperfusion-induced renal injury. However, the key components in the exosomes and their potential mechanisms for the kidney protective effects are not well understood. In our current study, we focused on the abundant proteins in exosomes derived from MSCs (MSC-exo) and found that the C-C motif chemokine receptor-2 (CCR2) was expressed on MSC-exo with a high ability to bind to its ligand CCL2. We also proved that CCR2 high-expressed MSC-exo could reduce the concentration of free CCL2 and suppress its functions to recruit or activate macrophage. Further, knockdown of CCR2 expression on the MSC-exo greatly abolished these effects. Finally, we also found that CCR2 knockdown impaired the protective effects of MSC-exo for the renal ischemia/reperfusion injury in mouse. The results indicate that CCR2 expressed on MSC-exo may play a key role in inflammation regulation and renal injury repair by acting as a decoy to suppress CCL2 activity. Our study may cast new light on understanding the functions of the MSC-exo and these receptor proteins expressed on exosomes.

This randomized controlled trial investigated the safety and efficacy of MF4637, a high concentrate omega-3 fatty acid preparation, in correcting the omega-3 fatty acid nutritional deficiency in non-alcoholic fatty liver disease (NAFLD). The primary end point of the study was set as the change of red blood cell (RBC) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) by MF4637. Whether the omega-3 concentrate could lower liver fat was evaluated in a subset of patients. Furthermore, 176 subjects with NAFLD were randomized to receive the omega-3 concentrate (n = 87) or placebo (n = 89) for 24 weeks, in addition to following standard-of-care dietary guidelines. The omega-3 index, omega-6: omega-3 fatty acid ratio and quantitative measurements of RBC EPA and DHA were determined at baseline and study completion. Magnetic resonance imaging of liver fat was conducted in a subset of patients. Administration of high concentrate omega-3 for 24 weeks significantly increased the omega-3 index and absolute values of RBC EPA and DHA, and decreased the RBC omega-6: omega-3 fatty acid ratio (p < 0.0001). A significant reduction in liver fat content was reported in both groups.

Other investigators have demonstrated by transfer of medium from irradiated cells and by irradiation with low-fluence alpha particles or microbeams that cells do not have to be directly exposed to ionizing radiation to be detrimentally affected, i.e. bystander effects. In this study, we demonstrate by transfer of medium from X-irradiated human CGL1 hybrid cells that the killing of bystander cells reduces the plating efficiency of the nonirradiated CGL1 cells by 33 +/- 6%. In addition, we show that the amount of cell death induced by bystander effects is not dependent on X-ray dose, and that the induction of apoptosis does not appear to be responsible for the cell death. Furthermore, we found that the reduction in plating efficiency in bystander cells is evident for over 18 days, or 22 cell population doublings, after medium transfer, despite repeated refeeding of the cell cultures. Finally, we report the novel observation that bystander effects induced by the transfer of medium from irradiated cells can induce neoplastic transformation. Exposing unirradiated CGL1 cells to medium from cells irradiated with 5 or 7 Gy increased the frequency of neoplastic transformation significantly from 6.3 x 10(-6) in unirradiated controls to 2.3 x 10(-5) (a factor of nearly four). We conclude that the bystander effect induces persistent, long-term, transmissible changes in the progeny of CGL1 cells that result in delayed death and neoplastic transformation. The data suggest that neoplastic transformation in bystander cells may play a significant role in radiation-induced neoplastic transformation at lower doses of X rays.

Decline in successful conception decreases more rapidly after 38 years of age owing to follicular depletion and decreased oocyte quality. However, limited information is available regarding the underlying mechanism and the useful treatment. This study aimed to evaluate the effects of growth hormone supplementation on oocyte maturation in vivo in aged and young mice and to determine its effect on mitochondrial function. The influence of three different doses of recombinant human growth hormone (rhGH) (0.4, 0.8 and 1.6 mg/kg/day) for 8 weeks before ovarian stimulation was analyzed. Superovulated oocytes were released from the oviduct of 12-week-old and 40-week-old female C57BL/6J mice 14–16 h after administration of human chorionic gonadotropin. Ovarian follicle and morphological analysis and oocyte maturation parameters were then evaluated. This study is the first, to our knowledge, to report that medium- and high-dose rhGH significantly increases antral follicles in aged mice but anti-Müllerian hormone (AMH) levels. Furthermore, derived oocytes, MII-stage oocyte rate, ATP levels, mitochondrial membrane potential and frequencies of homogeneous mitochondrial distribution increased. In contrast, in both aged and young mice, the mtDNA copy numbers per oocyte were similar before rhGH administration, and upon saline administration, they did not differ significantly. We conclude that medium-dose rhGH supplementation before standard ovarian stimulation regimens improves oocyte quality in aged mice, probably by enhancing mitochondrial functionality.

Aim: To test the hypothesis that genistein stimulates the osteoblastic differentiation through the p38 mitogen activated protein kinase (MAPK)-core-binding factor 1 (Cbfa1) pathway. Methods: The activation of p38 MAPK was detected by Western blotting. Alkaline phosphatase (ALP) activity and calcium deposition were assessed for osteoblastic differentiation of bone marrow-derived mesenchymal stem cell (BMSC) cultures. The expression of Cbfa1 was analyzed at both the mRNA and protein levels. The activity of Cbfa1 was detected by electrophoretic mobility shift assay. Bone sialoprotein (BSP), ALP, osteocalcin (OC), and osteopontin (OPN) gene transcription were also evaluated by either RT-PCR or Northern blotting. Results: Genistein (0.01-1 µmol/L) dose dependently led to the rapid and sustained activation of the p38 MAPK pathway in mouse BMSC cultures. Treatment with genistein (1 µmol/L) resulted in increased ALP activity and calcium deposition of BMSC cultures as a function of time. Genistein also enhanced Cbfa1 DNA binding activity and promoted the expressions of Cbfa1 itself as well as several Cbfa1-regulated genes, including ALP, BSP, OC, and OPN. Concurrent treatment with p38 MAPK inhibitor (SB203580) diminished the genistein-induced osteoblastic maturation and p38 MAPK-Cbfa1 activation in mouse BMSC cultures. Conclusion: These results indicated that genistein could stimulate the osteoblastic differentiation of BMSC cultures through the p38 MAPK-Cbfa1 pathway.