Exosomes derived from mesenchymal stem cells in diabetes and diabetic complications.

Diabetes, a group of metabolic disorders, constitutes an important global health problem. Diabetes and its complications place a heavy financial strain on both patients and the global healthcare establishment. The lack of effective treatments contributes to this pessimistic situation and negative outlook. Exosomes released from mesenchymal stromal cells (MSCs) have emerged as the most likely new breakthrough and advancement in treating of diabetes and diabetes-associated complication due to its capacity of intercellular communication, modulating the local microenvironment, and regulating cellular processes. In the present review, we briefly outlined the properties of MSCs-derived exosomes, provided a thorough summary of their biological functions and potential uses in diabetes and its related complications.

Senescent immune cells release grancalcin to promote skeletal aging.

Skeletal aging is characterized by low bone turnover and marrow fat accumulation. However, the underlying mechanism for this imbalance is unclear. Here, we show that during aging in rats and mice proinflammatory and senescent subtypes of immune cells, including macrophages and neutrophils, accumulate in the bone marrow and secrete abundant grancalcin. The injection of recombinant grancalcin into young mice was sufficient to induce premature skeletal aging. In contrast, genetic deletion of Gca in neutrophils and macrophages delayed skeletal aging. Mechanistically, we found that grancalcin binds to the plexin-b2 receptor and partially inactivates its downstream signaling pathways, thus repressing osteogenesis and promoting adipogenesis of bone marrow mesenchymal stromal cells. Heterozygous genetic deletion of Plexnb2 in skeletal stem cells abrogated the improved bone phenotype of Gca-knockout mice. Finally, we developed a grancalcin-neutralizing antibody and showed that its treatment of older mice improved bone health. Together, our data suggest that grancalcin could be a potential target for the treatment of age-related osteoporosis.

Downregulation of rho-associated protein kinase 1 by miR-124 in colorectal cancer.

AIM: To investigate the roles and interactions of rho-associated protein kinase (ROCK)1 and miR-124 in human colorectal cancer (CRC). METHODS: Expression of ROCK1 protein was examined by Western blotting, and quantitative reverse transcriptase PCR was performed to measure expression of ROCK1 mRNA and miR-124. Two cancer cell lines were transfected with pre-miR-124 (mimic) and anti-miR-124 (inhibitor) and the effects on ROCK1 protein and mRNA expression were observed. In addition, cell proliferation was assessed via a 5-ethynyl-2' deoxyuridine assay. Soft agar formation assay, and cell migration and invasion assays were used to determine the effect of survivin on the transformation and invasion activity of CRC cells. RESULTS: miR-124 was significantly downregulated in CRC compared to normal specimens (0.603 ± 0.092 vs 1.147 ± 0.286, P = 0.016) and in metastatic compared to nonmetastatic CRC specimens (0.416 ± 0.047 vs 0.696 ± 0.089, P = 0.020). Expression of miR-124 was significantly associated with CRC metastasis, tumor T and N stages, and tumor grade (all P < 0.05). ROCK1 protein was significantly increased in CRC compared to normal tissues (1.896 ± 0.258 vs 0.866 ± 0.136, P = 0.026), whereas ROCK1 mRNA expression was unaltered (2.613 ± 0.251 vs 2.325 ± 0.246). miR-124 and ROCK1 were inversely expressed in CRC tissues and cell lines. ROCK1 mRNA was unaltered in cells transfected with miR-124 mimic and miR-124 inhibitor, compared to normal controls. There was a significant reduction in ROCK1 protein in cells transfected with miR-124 mimic and a significant increase in cells transfected with miR-124 inhibitor (Ps < 0.05). Transformation and invasion of cells transfected with miR-124 inhibitor were significantly increased compared to those in normal controls (P < 0.05). Cells transfected with miR-124 inhibitor showed increased cell proliferation. CONCLUSION: miR-124 promotes hyperplasia and contributes to invasion of CRC cells, but downregulates ROCK1. ROCK1 and miR-124 may play important roles in CRC.