Comparison of the Cardiomyogenic Potency of Human Amniotic Fluid and Bone Marrow Mesenchymal Stem Cells

Different Sources of Bone Marrow Mesenchymal Stem Cells: A Comparison of Subchondral, Mandibular, and Tibia Bone-derived Mesenchymal Stem Cells

BACKGROUND

Stem cell properties vary considerably based on the source and tissue site of mesenchymal stem cells (MSCs). The mandibular condyle is a unique kind of craniofacial bone with a special structure and a relatively high remodeling rate. MSCs here may also be unique to address specific physical needs.

OBJECTIVE

The aim of this study was to compare the proliferation and multidirectional differentiation potential among MSCs derived from the tibia (TMSCs), mandibular ramus marrow (MMSCs), and condylar subchondral bone (SMSCs) of rats in vitro.

METHODS

Cell proliferation and migration were assessed by CCK-8, laser confocal, and cell scratch assays. Histochemical staining and real-time PCR were used to evaluate the multidirectional differentiation potential and DNA methylation and histone deacetylation levels.

RESULTS

The proliferation rate and self-renewal capacity of SMSCs were significantly higher than those of MMSCs and TMSCs. Moreover, SMSCs possessed significantly higher mineralization and osteogenic differentiation potential. Dnmt2, Dnmt3b, Hdac6, Hdac7, Hdac9, and Hdac10 may be instrumental in the osteogenesis of SMSCs. In addition, SMSCs are distinct from MMSCs and TMSCs with lower adipogenic differentiation and chondrogenic differentiation potential. The multidirectional differentiation capacities of TMSCs were exactly the opposite of those of SMSCs, and the results of MMSCs were intermediate.

CONCLUSION

This research offers a new paradigm in which SMSCs could be a useful source of stem cells for further application in stem cell-based medical therapies due to their strong cell renewal and osteogenic capacity.

Amniotic Fluid Mesenchymal Stromal Cells Derived from Fetuses with Isolated Cardiac Defects Exhibit Decreased Proliferation and Cardiomyogenic Potential

Amniotic fluid mesenchymal stromal cells (AF-MSCs) represent an autologous cell source to ameliorate congenital heart defects (CHDs) in children. The AF-MSCs, having cardiomyogenic potential and being of fetal origin, may reflect the physiological and pathological changes in the fetal heart during embryogenesis. Hence, the study of defects in the functional properties of these stem cells during fetal heart development will help obtain a better understanding of the cause of neonatal CHDs. Therefore, in the present study, we compared the proliferative and cardiomyogenic potential of AF-MSCs derived from ICHD fetuses (ICHD AF-MSCs) with AF-MSCs from structurally normal fetuses (normal AF-MSCs). Compared to normal AF-MSCs, the ICHD AF-MSCs showed comparable immunophenotypic MSC marker expression and adipogenic and chondrogenic differentiation potential, with decreased proliferation, higher senescence, increased expression of DNA-damaged genes, and osteogenic differentiation potential. Furthermore, the expression of cardiac progenitor markers (PDGFR-α, VEGFR-2, and SSEA-1), cardiac transcription factors (GATA-4, NKx 2-5, ISL-1, TBX-5, TBX-18, and MeF-2C), and cardiovascular markers (cTNT, CD31, and α-SMA) were significantly reduced in ICHD AF-MSCs. Overall, these results suggest that the AF-MSCs of ICHD fetuses have proliferation defects with significantly decreased cardiomyogenic differentiation potential. Thus, these defects in ICHD AF-MSCs highlight that the impaired heart development in ICHD fetuses may be due to defects in the stem cells associated with heart development during embryogenesis.

Histone demethylase KDM5B catalyzed H3K4me3 demethylation to promote differentiation of bone marrow mesenchymal stem cells into cardiomyocytes

Background

Studies have shown that histone H3 methylation is involved in regulating the differentiation of Bone Marrow Mesenchymal Stem Cells (BMSCs). KDM5B can specifically reduce the level of histone 3 lysine 4 trimethylation (H3K4me3), thereby activating the expression of related genes and participating in biological processes such as cell differentiation, embryonic development and tumor formation. Whether KDM5B is involved in the regulation of BMSCs differentiation into cardiomyocytes through the above manner has not been reported.

Objective

To investigate the effect of KDM5B on the induction and differentiation of swine BMSCs into myocardial cells in vitro.

Methods

Swine bone marrow BMSCs were isolated and cultured, and the overexpression, interference expression and blank vector of KMD5B were constructed and transfected by lentivirus. BMSCs was induced to differentiate into cardiomyocytes by 5-azacytidine (5-AZA) in vitro, and the differentiation efficiency was compared by immunofluorescence, RT-PCR, Western Blot and whole-cell patch clamp detection.

Result

Compared with the control group, the expression levels of histone H3K4me3 and pluripotency gene Nanog in KDM5B overexpression group were significantly decreased, while the expression level of key myocardial gene HCN4 and myocardial marker gene α-Actin and cTNT were significantly increased, and the Na⁺ current density on the surface of differentiated myocardial cell membrane was significantly increased. Meanwhile, the corresponding results of the KDM5B silent expression group were just opposite.

Conclusions

It indicated that enhanced KDM5B expression could promote the differentiation of BMSCs into cardiomyocytes and improve the differentiation efficiency by controlling H3K4 methylation levels.

A systematic review on the role of MSC-derived exosomal miRNAs in the treatment of heart failure

BACKGROUND

This systematic review summarizes results of studies that evaluated the expression of microRNAs (miRs) in pre-diabetes or type 2 diabetes.

METHODS

The information was obtained in PubMed, EMBL-EBI, Wanfang, Trip Database, Lilacs, CINAHL and Google. A qualitative synthesis of the results was performed and miRs frequency was graphically. From 1880 we identified studies, only 53 fulfilled the inclusion criteria. The 53 studies analyzed miRs in T2D; and of them, thirteen also described data in pre-diabetes.

RESULTS

In diabetics, 122 miRs were reported and 35 miRs for pre-diabetics. However, we identified that 5 miRs (-122-5p, 144-3p, 210, 375, -126b) were reported more often in diabetics, and 4 (144-3p, -192, 29a and -30d) in pre-diabetics.

CONCLUSIONS

Circulating miRs could be used as biomarkers of type 2 diabetes. However, it is necessary to validate these microRNAs in prospective and multi-center studies, where different population subgroups, considering the age, gender, and risk factors.

H3K9me2 regulates early transcription factors to promote mesenchymal stem‑cell differentiation into cardiomyocytes

Studies have shown that histone H3 at lysine 9 (H3K9me2) is an important epigenetic modifier of embryonic development, cell reprogramming and cell differentiation, but its specific role in cardiomyocyte formation remains to be elucidated. The present study established a model of 5‑Azacytidine‑induced differentiation of rat bone mesenchymal stem cells (MSCs) into cardiomyocytes and, on this basis, investigated the dimethylation of H3K9me2 and its effect on cardiomyocyte formation by knockdown of H3K9me2 methylase, euchromatic histone‑lysine N‑methyltransferase 2 (G9a) and H3K9me2 lysine demethylase 3A (KDM3A). The results demonstrated that, in comparison with the normal induction process, the knockdown of G9a could significantly reduce the H3K9me2 level of the MSCs in the induced model. Reverse transcription‑quantitative (RT‑q) PCR demonstrated that the expression of cardiac troponin T(cTnT) was significantly increased. In addition, flow cytometry demonstrated that the proportion of cTnT‑positive cells was significantly increased on day 21. With the knockdown of KDM3A, the opposite occurred. In order to explore the specific way of H3K9me2 regulating cardiomyocyte formation, western blotting and RT‑qPCR were used to detect the expression of key transcription factors including GATA binding protein 4 (GATA‑4), NK2 Homeobox 5 (Nkx2.5) and myocyte enhancer factor 2c (MEF2c) during cardiomyocyte formation. The decrease of H3K9me2 increased the expression of transcription factors GATA‑4, Nkx2.5 and MEF2c in the early stage of myocardial development while the increase of H3K9me2 inhibited the expression of those transcription factors. Accordingly, it was concluded that H3K9me2 is a negative regulator of cardiomyocyte formation and can participate in cardiomyocyte formation by activating or inhibiting key transcription factors of cardiomyocytes, which will lay the foundation for the optimized induction efficiency of cardiomyocytes in in vitro and clinical applications.

Metabolic Profile and Neurogenic Potential of Human Amniotic Fluid Stem Cells From Normal vs. Fetus-Affected Gestations

Human amniotic fluid stem cells (hAFSCs) possess some characteristics with mesenchymal stem cells (MSCs) and embryonic stem cells and have a broader differentiation potential compared to MSCs derived from other sources. Although hAFSCs are widely researched, their analysis mainly involves stem cells (SCs) obtained from normal, fetus-unaffected gestations. However, in clinical settings, knowledge about hAFSCs from normal gestations could be poorly translational, as hAFSCs from healthy and fetus-diseased gestations may differ in their differentiation and metabolic potential. Therefore, a more thorough investigation of hAFSCs derived from pathological gestations would provide researchers with the knowledge about the general characteristics of these cells that could be valuable for further scientific investigations and possible future clinical applicability. The goal of this study was to look into the neurogenic and metabolic potential of hAFSCs derived from diseased fetuses, when gestations were concomitant with polyhydramnios and compare them to hAFSCs derived from normal fetuses. Results demonstrated that these cells are similar in gene expression levels of stemness markers (SOX2, NANOG, LIN28A, etc.). However, they differ in expression of CD13, CD73, CD90, and CD105, as flow cytometry analysis revealed higher expression in hAFSCs from unaffected gestations. Furthermore, hAFSCs from “Normal” and “Pathology” groups were different in oxidative phosphorylation rate, as well as level of ATP and reactive oxygen species production. Although the secretion of neurotrophic factors BDNF and VEGF was of comparable degree, as evaluated with enzyme-linked immunosorbent assay (ELISA) test, hAFSCs from normal gestations were found to be more prone to neurogenic differentiation, compared to hAFSCs from polyhydramnios. Furthermore, hAFSCs from polyhydramnios were distinguished by higher secretion of pro-inflammatory cytokine TNFα, which was significantly downregulated in differentiated cells. Overall, these observations show that hAFSCs from pathological gestations with polyhydramnios differ in metabolic and inflammatory status and also possess lower neurogenic potential compared to hAFSCs from normal gestations. Therefore, further in vitro and in vivo studies are necessary to dissect the potential of hAFSCs from polyhydramnios in stem cell-based therapies. Future studies should also search for strategies that could improve the characteristics of hAFSCs derived from diseased fetuses in order for those cells to be successfully applied for regenerative medicine purposes.

Bone marrow-derived mesenchymal stem cells attenuate myocardial ischemia-reperfusion injury via upregulation of splenic regulatory T cells

BACKGROUND

Myocardial ischemia-reperfusion injury (MIRI) is the main pathological manifestation of cardiovascular diseases such as myocardial infarction. The potential therapeutic effects of bone marrow-derived mesenchymal stem cells (BM-MSCs) and the participation of regulatory T cells (Tregs) in MIRI remains to be defined.

METHODS

We used the experimental acute MIRI that was induced in mice by left ascending coronary ischemia, which were subsequently randomized to receive immunoglobulin G (IgG) or anti-CD25 antibody PC61 with or without intravenously injected BM-MSCs. The splenectomized mice underwent prior to experimental MIRI followed by intravenous administration of BM-MSCs. At 72 h post-MIRI, the hearts and spleens were harvested and subjected to cytometric and histologic analyses.

RESULTS

CD25+Foxp3+ regulatory T cells were significantly elevated after MIRI in the hearts and spleens of mice receiving IgG + BM-MSCs and PC61 + BM-MSCs compared to the respective control mice (all p < 0.01). This was accompanied by upregulation of interleukin 10 and transforming growth factor β1 and downregulation of creatinine kinase and lactate dehydrogenase in the serum. The post-MIRI mice receiving BM-MSCs showed attenuated inflammation and cellular apoptosis in the heart. Meanwhile, splenectomy compromised all therapeutic effects of BM-MSCs.

CONCLUSION

Administration of BM-MSCs effectively alleviates MIRI in mice through inducing Treg activation, particularly in the spleen.