METHODS AND RESULTS: Histopathology revealed increased collagen deposition and altered fiber arrangement in the NP and isoproterenol hydrochloride (ISO) groups compared with the blank group. Systolic and diastolic functions were impaired. Western blotting and qRT-PCR demonstrated that the expression of central myofibrosis-related proteins (collagens Ι and ΙΙΙ, MMP2, MMP9, TGF-β1, α-SMA, IL-1β, and TGF-β1) and genes (Collagen Ι, Collagen ΙΙΙ, TGF-β1, and α-SMA mRNA) was upregulated in the NP and ISO groups compared with the blank group. The mRNA-seq analysis indicated differential expression of TGF-β1 signaling pathway-associated genes and proteins. Fibrosis-related protein and gene expression increased in the CFs stimulated with the recombinant human TGF-β1 and NP, which was consistent with the results of animal experiments. According to the immunofluorescence analysis and western blotting, NP exposure activated the TGF-β1/LIMK1 signaling pathway whose action mechanism in NP-induced CFs was further validated using the LIMK1 inhibitor (BMS-5). The inhibitor modulated the TGF-β1/LIMK1 signaling pathway and suppressed the NP-induced increase in fibrosis-related protein expression in the CFs. Thus, the aforementioned pathway is involved in NP-induced fibrosis.
CONCLUSION: We here provide the first evidence that perinatal NP exposure causes myocardial fibrosis in growing male rat pups and reveal the molecular mechanism and functional role of the TGF-β1/LIMK1 signaling pathway in this process.
METHODS: The harvested stem cells from adipose tissues were isolated, cultured, and then starved. The centrifugation of cell cultures medium yielded the human adipose-derived stem cells conditional medium (HADSCs-CM). Collagen secretion and fibroblast viability of human fibroblasts (Hs68) were measured in the presence of HADSCs-CM. The dermal layer, vascular endothelial growth factor (VEGF), and collagen levels were evaluated on the mice animal models between the treatments with and without HADSCs-CM.
RESULTS: Western blotting, transmission electron microscopy (TEM), and dynamic light scattering (DLS) confirmed that the functional particles in HADSCs-CM were exosomes. When Hs68 fibroblasts were treated with HADSCs-CM, both cell viability and collagen secretion increased in a dose-dependent manner. Following the post-ultraviolet A (post-UVA) exposure, the mice exposed to the HADSCs-CM have decreased dermal thickness and VEGF expression and increased collagen volume compared to the non-HADSCs-CM exposed mice (control group).
CONCLUSION: HADSCs-CM significantly alleviated signs of skin senescence, including reduced dermal thickness, decreased VEGF expression, and enhanced collagen production. Exosomes, identified in the HADSCs-CM, are the functional component of these regenerative effects. This study highlights that the exosomal nanomedicine found in HADSCs-CM could regenerate skin, boost collagen production, improve fibroblast cell viability, and contain functional exosomes.
MATERIALS AND METHODS: Human adipose-derived stem cells at passage 4 were evaluated by flow cytometry to examine the expression of surface markers. These adipose-derived stem cells were tested for adipogenic and osteogenic differentiation capacity. Ribonucleic acid was extracted from the cells for quantitative polymerase chain reaction analysis to determine the expression levels of chondrogenic genes after chondrogenic induction.
RESULTS: Human adipose-derived stem cells were strongly positive for the mesenchymal markers CD90, CD73, CD44, CD9, and histocompatibility antigen and successfully differentiated into adipogenic and osteogenic lineages. The human adipose-derived stem cells aggregated and formed a dense matrix after chondrogenic induction. The expression of chondrogenic genes (collagen type II, aggrecan core protein, collagen type XI, COMP, and ELASTIN) was significantly higher after the first week of induction. However, a significantly elevated expression of collagen type X was observed after three weeks of chondrogenic induction.
CONCLUSION: Human adipose-derived stem cells retain stem cell characteristics after expansion in culture to passage 4 and serve as a feasible source of cells for cartilage regeneration. Chondrogenesis in human adipose-derived stem cells was most prominent after one week of chondrogenic induction.