Recently, a study titled "iPSC-derived mesenchymal stromal cells stimulate neovascularization less than their primary counterparts" was published in Life Sci, focusing on induced pluripotent stem cells (iMSCs) derived from mesenchymal stromal cells (iPSCs) reprogrammed from bone marrow mesenchymal stromal cells (BM-MSCs), and comparing their effects on angiogenesis with bone marrow mesenchymal stromal cells (BM-MSCs).

Studies have found that iMSCs are not as effective as BM-MSCs in promoting angiogenesis, which are more effective in stimulating endothelial cells to form interconnected vascular structures. RNA sequencing showed that the expression of vascularization-related genes in the iMSCs co-culture system was significantly lower than that in the BM-MSCs co-culture system.

In this study, bone marrow mesenchymal stromal cells (BM-MSCs) were taken from the femoral head of patients, obtained through puncture, and cultured, passaged and cryopreserved in specific culture medium. Human umbilical vein endothelial cells (HUVECs) were extracted from the umbilical cord, subjected to collagenase digestion and other treatments, and cultured in gel-coated culture flasks. This culture method helps maintain the endothelial cell characteristics of HUVECs and can be used for subsequent angiogenesis experiments.

Induced pluripotent stem cells (iPSCs) were obtained from BM-MSCs through reprogramming technology and cultured under appropriate conditions to verify their pluripotency. After confirming the pluripotency of iPSCs, the cells were passaged for further experiments. Subsequently, iPSCs were induced to differentiate into mesenchymal stromal cells (iMSCs). During the differentiation process, differentiation is induced by switching the medium at specific stages, and regular operations are performed during the culture period to ensure the quality and function of the cells.

In terms of experimental methods, the study analyzed surface markers such as CD29 and CD73 through flow cytometry to determine the phenotypic characteristics of cells. During the gel preparation process, human plasma fibrinogen was carefully processed, mixed with cells and injected into a microfluidic chip, followed by incubation and replenishment of culture medium to maintain the growth environment of the cells. Immunofluorescence visualization and analysis are completed by fixing and staining chip gel, imaging using confocal microscopy, and then quantitative analysis of vessel structure is performed with the help of professional software. Transmission electron microscopy performed complex processing of gel samples to observe the ultrastructure of cells.

From the perspective of gene expression, RNA sequencing results showed that the expression level of vascularization-related genes in BM-MSCs was much higher than that in iMSCs. For example, the expression of key pro-angiogenic genes such as angiopoietin 2 in BM-MSCs is significantly higher than in iMSCs. Further Gene Ontology (GO) analysis and Gene Set Enrichment Analysis (GSEA) showed that in the co-culture system of iMSCs, genes related to metabolism and cell differentiation were significantly upregulated, while in the co-culture system of BM-MSCs, the expression of genes related to mitosis, inflammation and angiogenesis was significantly increased.

To sum up, despite the genetic and epigenetic differences between iMSCs and BM-MSCs, iMSCs still have great potential in immune regulation and tissue regeneration, and their low pro-angiogenic properties are useful in osteoarthritis, ocular degenerative diseases and other diseases. Treatment is more valuable. In addition, since their preparation is unlike BM-MSCs with limited sources and donor age limitations, iMSCs can be produced on a large scale through reprogramming. These characteristics make iMSCs a promising alternative cell source that can overcome the limitations of primary MSCs in cell acquisition, expansion and clinical applications. By optimizing the preparation and application strategy of iMSCs, it is expected to promote the development of cell therapy in a precise direction and bring more hope for cure to patients.