MiR-24-3p regulates the differentiation of adipose-derived stem cells toward pericytes and promotes fat grafting vascularization

MicroRNAs in adipose tissue fibrosis: Mechanisms and therapeutic potential

Adipose tissue fibrosis, characterized by abnormal extracellular matrix deposition within adipose tissue, signifies a crucial indicator of adipose tissue malfunction, potentially leading to organ tissue dysfunction. Various factors, including a high-fat diet, non-alcoholic fatty liver disease, and insulin resistance, coincide with adipose tissue fibrosis. MicroRNAs (miRNAs) represent a class of small non-coding RNAs with significant influence on tissue fibrosis through diverse signaling pathways. For instance, in response to a high-fat diet, miRNAs can modulate signaling pathways such as TGF-β/Smad, PI3K/AKT, and PPAR-γ to impact adipose tissue fibrosis. Furthermore, miRNAs play roles in inhibiting fibrosis in different contexts: suppressing corneal fibrosis via the TGF-β/Smad pathway, mitigating cardiac fibrosis through the VEGF signaling pathway, reducing wound fibrosis via regulation of the MAPK signaling pathway, and diminishing fibrosis post-fat transplantation via involvement in the PDGFR-β signaling pathway. Notably, the secretome released by miRNA-transfected adipose-derived stem cells facilitates targeted delivery of miRNAs to evade host immune rejection, enhancing their anti-fibrotic efficacy. Hence, this study endeavors to elucidate the role and mechanism of miRNAs in adipose tissue fibrosis and explore the mechanisms and advantages of the secretome released by miRNA-transfected adipose-derived stem cells in combating fibrotic diseases.

Dexmedetomidine regulates the anti-oxidation and autophagy of adipose-derived stromal cells under H2O2-induced oxidative stress through Nrf2/p62 pathway and improves the retention rate of autologous fat transplantation

To investigate the protective mechanism of dexmedetomidine (DEX) on adipose-derived stromal cells (ADSCs) under oxidative stress model and its promotion effect on the retention rate of adipose granule transplantation by in vitro and in vivo experiments. The experiment was divided into control group, model group (ADSCs + H2O2+normal serum), DEX group (ADSCs + H202+DEX drug-containing serum), autophagy agonist group (ADSCs + H2O2+rapamycin (RAP)+normal serum), RAP + DEX group (ADSCs + H2O2+normal serum), RAP + DEX drug-containing serum), autophagy inhibitor group (ADSCs + H2O2+chloroquine (CQ)+normal serum), CQ + DEX group (ADSCs + H2O2+CQ + DEX drug-containing serum). HO-1, GSH-PX, SOD and CAT in ADSCs under oxidative stress model were measured. ROS fluorescence intensity and apoptosis ratio were detected. Expression of Nrf2, LC3-II/LC3-I and p62 were detected. In vivo, fat mixed with ADSCs or DEX -pretreated ADSCs was implanted subcutaneously in the lower back region of nude mice. Fat grafts were collected and analyzed at 2-, 4-, 6-, and 8-weeks post-transplantation. DEX pretreatment could reduce the expression of p62 to enhance the autophagy level of ADSCs under oxidative stress model. Additionally, cotransplantation of DEX-pretreated ADSCs with fat improved the long-term texture of fat grafts. DEX increased the fat graft survival and angiogenesis.

The Evolving Function of Vasculature and Pro-angiogenic Therapy in Fat Grafting

Autologous fat grating is a widely-accepted method to correct soft tissue deficiency. Although fat transplantation shows excellent biocompatibility and simple applicability, the relatively low retention rate caused by fat necrosis is still a challenge. The vasculature is integral after fat grafting, serving multiple crucial functions. Rapid and effective angiogenesis within grafts is essential for supplying oxygen necessary for adipocytes' survival. It facilitates the influx of inflammatory cells to remove necrotic adipocytes and aids in the delivery of regenerative cells for adipose tissue regeneration in fat grafts. The vasculature also provides a niche for interaction between adipose progenitor cells and vascular progenitor cells, enhancing angiogenesis and adipogenesis in grafts. Various methods, such as enriching grafts with diverse pro-angiogenic cells or utilizing cell-free approaches, have been employed to enhance angiogenesis. Beige and dedifferentiated adipocytes in grafts could increase vessel density. This review aims to outline the function of vasculature in fat grafting and discuss different cell or cell-free approaches that can enhance angiogenesis following fat grafting.

Aging and Metabolic Reprogramming of Adipose-Derived Stem Cells Affect Molecular Mechanisms Related to Cardiovascular Diseases

We performed a systematic search of the PubMed database for English-language articles related to the function of adipose-derived stem cells in the pathogenesis of cardiovascular diseases. In preclinical models, adipose-derived stem cells protected arteries and the heart from oxidative stress and inflammation and preserved angiogenesis. However, clinical trials did not reiterate successful treatments with these cells in preclinical models. The low success in patients may be due to aging and metabolic reprogramming associated with the loss of proliferation capacity and increased senescence of stem cells, loss of mitochondrial function, increased oxidative stress and inflammation, and adipogenesis with increased lipid deposition associated with the low potential to induce endothelial cell function and angiogenesis, cardiomyocyte survival, and restore heart function. Then, we identify noncoding RNAs that may be mechanistically related to these dysfunctions of human adipose-derived stem cells. In particular, a decrease in let-7, miR-17-92, miR-21, miR-145, and miR-221 led to the loss of their function with obesity, type 2 diabetes, oxidative stress, and inflammation. An increase in miR-34a, miR-486-5p, and mir-24-3p contributed to the loss of function, with a noteworthy increase in miR-34a with age. In contrast, miR-146a and miR-210 may protect stem cells. However, a systematic analysis of other noncoding RNAs in human adipose-derived stem cells is warranted. Overall, this review gives insight into modes to improve the functionality of human adipose-derived stem cells.