Immunomodulatory effects of mesenchymal stem cells for the treatment of cardiac allograft rejection

A Novel Construct of Coral Granules-Poly-L-Lactic Acid Nanomembrane Sandwich Double Stem Cell Sheet Transplantation as Regenerative Therapy of Bone Defect Model

OBJECTIVES

We examined the use of a new approach in nanotechnology and stem cell research as regenerative therapy for bone tissue defects.

MATERIALS AND METHODS

We compared in vitro osteogenic potential of human Wharton jelly mesenchymal stem cells using coral granules and poly-L-lactic acid nanofiber according to proliferation (by cck-8 kit) and osteogenes (runt-related transcription factor 2, alkaline phosphatase, osteonectin) by quantitative reverse transcription-polymerase chain reaction, alkaline phosphatase assay, calcium measurement, and assessment of mineralization by Alizarin red and von Kossa staining. To overcome the limitations of natural coral, we made a modification by packaging the coral granules-human Wharton jelly mesenchymal stem cells by nanomembrane-human Wharton jelly mesenchymal stem cells to form sandwich double cell sheets and compared this hole with other holes (one was filled by human Wharton jelly mesenchymal stem cell suspension, and the other was filled by coral granules saturated with preinduced mesenchymal stem cells) by radiological and histopathological studies for repairing the bone gap.

RESULTS

Collagen-coated poly-L-lactic acid showed higher mRNA levels for all osteogenes (P < .001), higher alkaline phosphatase and calcium content (P < .001), and greater stainability. Our in vivo experiment showed that the holes implanted with sandwich double cell sheet-poly-L-lactic acid coral were completely filled mature compact bone. The holes implanted with human Wharton jelly mesenchymal stem cells alone were filled with immature compact bone. Holes implanted with coral granules-human Wharton jelly mesenchymal stem cells were filled with condensed connective tissue.

CONCLUSIONS

Poly-L-lactic acid nanofiber has greater osteogenic differentiating effect than the coral granules. The new approach of sDCS-PLLA-coral construct proved success for bone regeneration and repairing the bone gap and this may improve the design of tissue constructs for bone tissue regenerative therapy.

Potential applications of mesenchymal stem cells and their derived exosomes in regenerative medicine

INTRODUCTION

Regenerative medicine involves the replacement of damaged cells, tissues, or organs to restore normal function. Mesenchymal stem cells (MSCs) and exosomes secreted by MSCs have unique advantages that make them a suitable candidate in the field of regenerative medicine.

AREAS COVERED

This article provides a comprehensive overview of regenerative medicine, focusing on the use of MSCs and their exosomes as potential therapies for replacing damaged cells, tissues, or organs. This article discusses the distinct advantages of both MSCs and their secreted exosomes, including their immunomodulatory effects, lack of immunogenicity, and recruitment to damaged areas. While both MSCs and exosomes have these advantages, MSCs also have the unique ability to self-renew and differentiate. This article also assesses the current challenges associated with the application of MSCs and their secreted exosomes in therapy. We have reviewed proposed solutions for improving MSC or exosome therapy, including ex-vivo preconditioning strategies, genetic modification, and encapsulation. Literature search was conducted using Google Scholar and PubMed databases.

EXPERT OPINION

Providing insight into the future development of MSC and exosome-based therapies and to encourage the scientific community to focus on the identified gaps, develop appropriate guidelines, and enhance the clinical application of these therapies.

Transcriptomic analysis and biological evaluation reveals that LMO3 regulates the osteogenic differentiation of human adipose derived stem cells via PI3K/Akt signaling pathway

Autologous bone transplantation which is a common treatment method for bone defects needs a large quantity of bone cells. In order to develop new treatments to regenerating bone tissues, this research aimed at identifying the key genes and finding their mechanism in human adipose-derived stem cells (hADSCs) osteogenesis. GSE63754, GSE89330 and GSE72429 were downloaded to perform GO functional and KEGG pathway analyses, construct a competing endogenous RNA (ceRNA) network, construct a PPI network and identify hub genes. The expression level of LMO3 during the osteogenesis of hADSCs was examined by quantitative reverse transcription polymerase chain reaction and western blot. Lentivirus transfection was used to knock down or overexpress LMO3, which enabled us to investigate the effect of LMO3 on osteogenic differentiation of hADSCs. Wortmannin were used to identify the mechanism of the LMO3/PI3K/Akt axis in regulating osteogenic differentiation of hADSCs. Moreover, ectopic bone formation in nude mice was used to investigate the effect of LMO3 on osteogenesis in vivo. In this study, we found the expression of LMO3 was significantly upregulated during the osteogenic differentiation of hADSCs. LMO3 knockdown remarkably suppressed osteogenic differentiation of hADSCs, while LMO3 overexpression promoted osteogenic differentiation of hADSCs both in vitro and in vivo. Moreover, we discovered that the enhancing effect of LMO3 overexpression on osteogenic differentiation was related to the activation of PI3K/Akt signaling pathway. Inhibition of PI3K/Akt signaling pathway with wortmannin effectively blocked the stimulation of osteogenic differentiation induced by LMO3 overexpression. In conclusion, based on transcriptomic analysis, we identified key genes involved in regulating the osteogenic differentiation of hADSCs. In addition, we found that LMO3 might act as a positive modulator of hADSC osteogenic differentiation by mediating PI3K/Akt signaling pathway. Manipulating the expression of LMO3 and its associated pathways might contribute to advances in bone regeneration and tissue engineering.