Effect of Atorvastatin on Angiogenesis-Related Genes VEGF-A, HGF and IGF-1 and the Modulation of PI3K/AKT/mTOR Transcripts in Bone-Marrow-Derived Mesenchymal Stem Cells

A novel miR-466l-3p/FGF23 axis promotes osteogenic differentiation of human bone marrow mesenchymal stem cells

BACKGROUND

MicroRNAs (miRNAs) regulate osteogenic differentiation processes and influence the development of osteoporosis (OP). This study aimed to investigate the potential role of miR-466 l-3p in OP.

METHODS

The expression levels of miR-466 l-3p and fibroblast growth factor 23 (FGF23) were quantified in the trabeculae of the femoral neck of 40 individuals with or without OP using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The impact of miR-466 l-3p or FGF23 expression on cell proliferation and the expression levels of runt-related transcription factor 2 (RUNX2), type I collagen (Col1), osteocalcin (OCN), osterix (OSX) and dentin matrix protein 1 (DMP1) was quantified in human bone marrow mesenchymal stem cells (hBMSCs) overexpressing miR-466 l-3p. Furthermore, alkaline phosphatase (ALP) staining and alizarin red staining were performed to measure ALP activity and the levels of calcium deposition, respectively. In addition, bioinformatics analysis, luciferase reporter assays, and RNA pull-down assays were conducted to explore the molecular mechanisms underlying the effects of miR-466 l-3p and FGF23 in osteogenic differentiation of hBMSCs.

RESULTS

The expression levels of miR-466 l-3p were significantly lower in femoral neck trabeculae of patients with OP than in the control cohort, whereas FGF23 levels exhibited the opposite trend. Furthermore, miR-466 l-3p levels were upregulated and FGF23 levels were downregulated in hBMSCs during osteogenic differentiation. Moreover, the high miR-466 l-3p expression enhanced the mRNA expression of RUNX2, Col1, OCN, OSX and DMP1, as well as cell proliferation, ALP activity, and calcium deposition in hBMSCs. FGF23 was found to be a direct target of miR-466 l-3p. FGF23 overexpression downregulated the expression of osteoblast markers and inhibited the osteogenic differentiation induced by miR-466 l-3p overexpression. qRT-PCR and Western blot assays showed that miR-466 l-3p overexpression decreased the expression levels of mRNAs and proteins associated with the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway, whereas FGF23 upregulation exhibited the opposite trend.

CONCLUSION

In conclusion, these findings suggest that miR-466 l-3p enhances the osteogenic differentiation of hBMSCs by suppressing FGF23 expression, ultimately preventing OP.

The Role of Stem Cells in the Treatment of Cardiovascular Diseases

Cardiovascular diseases (CVDs) are the leading cause of death and include several vascular and cardiac disorders, such as atherosclerosis, coronary artery disease, cardiomyopathies, and heart failure. Multiple treatment strategies exist for CVDs, but there is a need for regenerative treatment of damaged heart. Stem cells are a broad variety of cells with a great differentiation potential that have regenerative and immunomodulatory properties. Multiple studies have evaluated the efficacy of stem cells in CVDs, such as mesenchymal stem cells and induced pluripotent stem cell-derived cardiomyocytes. These studies have demonstrated that stem cells can improve the left ventricle ejection fraction, reduce fibrosis, and decrease infarct size. Other studies have investigated potential methods to improve the survival, engraftment, and functionality of stem cells in the treatment of CVDs. The aim of the present review is to summarize the current evidence on the role of stem cells in the treatment of CVDs, and how to improve their efficacy.

Stem cell-based therapy in cardiac repair after myocardial infarction: Promise, challenges, and future directions

Stem cells represent an attractive resource for cardiac regeneration. However, the survival and function of transplanted stem cells is poor and remains a major challenge for the development of effective therapies. As two main cell types currently under investigation in heart repair, mesenchymal stromal cells (MSCs) indirectly support endogenous regenerative capacities after transplantation, while induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) functionally integrate into the damaged myocardium and directly contribute to the restoration of its pump function. These two cell types are exposed to a common microenvironment with many stressors in ischemic heart tissue. This review summarizes the research progress on the mechanisms and challenges of MSCs and iPSC-CMs in post-MI heart repair, introduces several randomized clinical trials with 3D-mapping-guided cell therapy, and outlines recent findings related to the factors that affect the survival and function of stem cells. We also discuss the future directions for optimization such as biomaterial utilization, cell combinations, and intravenous injection of engineered nucleus-free MSCs.