Effect of human thymus adipose tissue-derived mesenchymal stem cells on myocardial infarction in rat model

Ghrelin promotes cardiomyocyte differentiation of adipose tissue‑derived mesenchymal stem cells by DDX17‑mediated regulation of the SFRP4/Wnt/β‑catenin axis

Adipose tissue‑derived mesenchymal stem cells (ADMSCs) differentiate into cardiomyocytes and may be an ideal cell source for myocardial regenerative medicine. Ghrelin is a gastric‑secreted peptide hormone involved in the multilineage differentiation of MSCs. To the best of our knowledge, however, the role and potential downstream regulatory mechanism of ghrelin in cardiomyocyte differentiation of ADMSCs is still unknown. The mRNA and protein levels were measured by reverse transcription‑quantitative PCR and western blotting. Immunofluorescence staining was used to show the expression and cellular localization of cardiomyocyte markers and β‑catenin. RNA sequencing was used to explore the differentially expressed genes (DEGs) that regulated by ghrelin. The present study found that ghrelin promoted cardiomyocyte differentiation of ADMSCs in a concentration‑dependent manner, as shown by increased levels of cardiomyocyte markers GATA binding protein 4, α‑myosin heavy chain (α‑MHC), ISL LIM homeobox 1, NK2 homeobox 5 and troponin T2, cardiac type. Ghrelin increased β‑catenin accumulation in nucleus and decreased the protein expression of secreted frizzled‑related protein 4 (SFRP4), an inhibitor of Wnt signaling. RNA sequencing was used to determine the DEGs regulated by ghrelin. Functional enrichment showed that DEGs were more enriched in cardiomyocyte differentiation‑associated terms and Wnt pathways. Dead‑box helicase 17 (DDX17), an upregulated DEG, showed enhanced mRNA and protein expression levels following ghrelin addition. Overexpression of DDX17 promoted protein expression of cardiac‑specific markers and β‑catenin and enhanced the fluorescence intensity of α‑MHC and β‑catenin. DDX17 upregulation inhibited protein expression of SFRP4. Rescue assay confirmed that the addition of SFRP4 partially reversed ghrelin‑enhanced protein levels of cardiac‑specific markers and the fluorescence intensity of α‑MHC. In conclusion, ghrelin promoted cardiomyocyte differentiation of ADMSCs by DDX17‑mediated regulation of the SFRP4/Wnt/β‑catenin axis.

Biomaterials-Based Cell Therapy for Myocardial Tissue Regeneration

Cardiovascular diseases (CVDs) have been the leading cause of death worldwide during the past several decades. Cell loss is the main problem that results in cardiac dysfunction and further mortality. Cell therapy aiming to replenish the lost cells is proposed to treat CVDs especially ischemic heart diseases which lead to a big portion of cell loss. Due to the direct injection's low cell retention and survival ratio, cell therapy using biomaterials as cell carriers has attracted more and more attention because of their promotion of cell delivery and maintenance at the aiming sites. In this review, the three main factors involved in cell therapy for myocardial tissue regeneration: cell sources (somatic cells, stem cells, and engineered cells), chemical components of cell carriers (natural materials, synthetic materials, and electroactive materials), and categories of cell delivery materials (patches, microspheres, injectable hydrogels, nanofiber and microneedles, etc.) are systematically summarized. An introduction of the methods including magnetic resonance/radionuclide/photoacoustic and fluorescence imaging for tracking the behavior of transplanted cells in vivo is also included. Current challenges of biomaterials-based cell therapy and their future directions are provided to give both beginners and professionals a clear view of the development and future trends in this area.

Human adipose-derived mesenchymal stem cells inhibit proliferation and induce apoptosis of human gastric cancer HGC-27 cells

The aim of this study was to explore the effects of human adipose-derived mesenchymal stem cells (ASCs) on the growth of gastric cancer cells in vivo and vitro and its mechanism. ASCs were isolated from abandoned adipose tissues, and the surface markers were identified by flow cytometry. In vitro experiments, HGC-27 cells cultured in ASCs-conditioned medium (CM) were assigned as the experimental group, while HGC-27 cells cultured in normal medium were as the control group. MTT and colony formation assays were performed to detect cell viability and colony formatting ability, respectively. Annexin-V/PI assay, Western blot, and caspase-3 enzyme activity assay were performed to detect cells apoptosis. The isolated ASCs could be differentiated into adipocytes and osteoblasts in vitro. Flow cytometry showed that CD73 and CD105 were positively expressed in HGC-27 cells. Compared with the mice injected HGC-27 cells only, the tumor formation in mice injected both ASCs and HGC-27 cells was significantly smaller (P < 0.05). The colony formation ability in experimental group was 40.09% smaller than control group (P < 0.05) and the cell apoptosis rate in experimental group was higher than the control group (P < 0.05). Furthermore, the expressions of cleaved PARP, cleaved caspase-3 proteins, and caspase-3 enzyme viability in experimental group were significantly higher than those of control group (P < 0.05). In conclusion, ASCs can effectively inhibit the growth of HGC-27 cells by inducing apoptosis.

Human mesenchymal stem cells encapsulated-coacervated photoluminescent nanodots layered bioactive chitosan/collagen hydrogel matrices to indorse cardiac healing after acute myocardial infarction

Acute Myocardial Infarction (MI) is one of the foremost causes of human death worldwide and it leads to mass death of cardiomyocytes, interchanges of unfavorable biological environment and affecting electrical communications by fibrosis scar formations, and specifically deficiency of blood supply to heart which leads to heart damage and heart failure. Recently, numerous appropriate strategies have been applied to base on solve these problems wound be provide prominent therapeutic potential to cardiac regeneration after acute MI. In the present study, a combined biopolymeric conductive hydrogel was fabricated with conductive ultra-small graphene quantum dots as a soft injectable hydrogel for cardiac regenerations. The resultant hydrogel was combined with human Mesenchymal stem cells (hMSCs) to improved angiogenesis in cardiovascular tissues and decreasing cardiomyocyte necrosis of hydrogel treated acute-infarcted region has been greatly associated with the development of cardiac functions in MI models. The prepared graphene quantum dots and hydrogel groups was physico-chemically analyzed and confirmed the suitability of the materials for cardiac regeneration applications. The in vitro analyzes of hydrogels with hMSCs have established that enhanced cell survival rate, increased expressions of pro-inflammatory factors, pro-angiogenic factors and early cardiogenic markers. The results of in vivo myocardial observations and electrocardiography data demonstrated a favorable outcome of ejection fraction, fibrosis area, vessel density with reduced infarction size, implying that significant development of heart regenerative function after MI. This novel strategy of injectable hydrogel with hMSCs could be appropriate for the effective treatment of cardiac therapies after acute MI.