Expression Profiles of MicroRNAs in Stem Cells Differentiation

MiR-539-3p inhibited chondrogenic differentiation in human adipose stem cells by targeting Sox9

Background

Mesenchymal stem cells (MSCs) have emerged as the attractive candidates for cell therapy for cartilage repair in clinical therapy of osteoarthritis (OA). MiR-539-3p was reported to differentially express during chondrogenic differentiation of adipose stem cells (ASCs) by miRNA microarrays. The aim of the study was to investigate the effects and underlying mechanisms of miR-539-3p on chondrogenic differentiation of ASCs.

Methods

Human ASCs (hASCs) were obtained from liposuction and transfected with miR-539-3p mimic or inhibitor. Then, the cells were cultured in chondrogenic differentiation medium including transforming growth factor-β1 (TGF-β1).

Results

Our results found that miR-539-3p was gradually down-regulated during chondrogenic differentiation of hASCs. MiR-539-3p overexpression inhibited TGF-β1-induced chondrogenic differentiation of hASCs, as supported by reducing the gene and protein expression of chondrogenic differentiation markers type II collagen alpha 1 (COL2A1), aggrecan (ACAN), and type II collagen. In contrast, miR-539-3p inhibitor significantly promoted the chondrogenic differentiation of hASCs. Dual luciferase reporter assay demonstrated that Sox9 was a direct target gene of miR-539-3p. The expression of SRY-box transcription factor 9 (Sox9) was up-regulated progressively over time during chondrogenic differentiation of hASCs. Additionally, Sox9 overexpression notably reversed chondrogenic differentiation of hASCs inhibited by miR-539-3p mimic, as demonstrated by the decreased expression of COL2A1, ACAN, and type II collagen.

Conclusions

Altogether, miR-539-3p inhibited chondrogenic differentiation of hASCs by targeting Sox9. MiR-539-3p may have significant clinical applications for use as a targeted therapy of OA.

Dynamic MicroRNA Expression Profiles During Embryonic Development Provide Novel Insights Into Cardiac Sinus Venosus/Inflow Tract Differentiation

MicroRNAs have been explored in different organisms and are involved as molecular switches modulating cellular specification and differentiation during the embryonic development, including the cardiovascular system. In this study, we analyze the expression profiles of different microRNAs during early cardiac development. By using whole mount in situ hybridization in developing chick embryos, with microRNA-specific LNA probes, we carried out a detailed study of miR-23b, miR-130a, miR-106a, and miR-100 expression during early stages of embryogenesis (HH3 to HH17). We also correlated those findings with putative microRNA target genes by means of mirWalk and TargetScan analyses. Our results demonstrate a dynamic expression pattern in cardiac precursor cells from the primitive streak to the cardiac looping stages for miR-23b, miR-130a, and miR-106a. Additionally, miR-100 is later detectable during cardiac looping stages (HH15-17). Interestingly, the sinus venosus/inflow tract was shown to be the most representative cardiac area for the convergent expression of the four microRNAs. Through in silico analysis we revealed that distinct Hox family members are predicted to be targeted by the above microRNAs. We also identified expression of several Hox genes in the sinus venosus at stages HH11 and HH15. In addition, by means of gain-of-function experiments both in cardiomyoblasts and sinus venosus explants, we demonstrated the modulation of the different Hox clusters, Hoxa, Hoxb, Hoxc, and Hoxd genes, by these microRNAs. Furthermore, we correlated the negative modulation of several Hox genes, such as Hoxa3, Hoxa4, Hoxa5, Hoxc6, or Hoxd4. Finally, we demonstrated through a dual luciferase assay that Hoxa1 is targeted by miR-130a and Hoxa4 is targeted by both miR-23b and miR-106a, supporting a possible role of these microRNAs in Hox gene modulation during differentiation and compartmentalization of the posterior structures of the developing venous pole of the heart.

Activated Human Umbilical Cord Blood Platelet-Rich Plasma Enhances the Beneficial Effects of Human Umbilical Cord Mesenchymal Stem Cells in Chemotherapy-Induced POF Rats

Saving the ovarian function of premature ovarian failure (POF) patients undergoing chemotherapy is an important problem in the field of reproductive medicine. At present, human umbilical cord mesenchymal stem cells (HucMSCs) have been used in the treatment of POF, but the effect is still not optimal. The purpose of this study was to determine whether human umbilical cord blood platelet-rich plasma (ucPRP) enhances the beneficial effects of HucMSCs in the treatment of POF. First, we observed the effects of changes in the biological activity of ucPRP on HucMSCs in vitro. Subsequently, we tracked the distribution and function of the HucMSCs in POF rats, and the rats' estrus cycle and serum sex hormones, follicular development, ovarian angiogenesis, ovarian granulosa cell proliferation, and apoptosis were assessed. The results of the study showed that the addition of ucPRP in vitro accelerates proliferation and reduces apoptosis of the HucMSCs while upregulating the stemness gene of the HucMSCs. The combined transplantation of HucMSCs and ucPRP resulted in more stem cells being retained in the ovaries of POF rats, the estrus cycle of the POF rats being restored, the levels of serum E2, AMH, and FSH improving, and damaged follicles beginning to grow. Finally, we confirmed that the potential mechanism of the combination of HucMSCs and ucPRP to rescue the ovarian function of POF rats is to promote ovarian angiogenesis and to promote the proliferation and reduce the apoptosis of ovarian granulosa cells. The upregulation of AMH and FHSR expression and the downregulation of caspase-3 expression in granulosa cells are potential mechanisms for the recovery of ovarian function. Our research results suggest that the combined application of HucMSCs and ucPRP is a safe and efficient transplantation program for the treatment of POF, thus providing a reliable experimental basis for the clinical application of stem cell therapy in POF.