Impaired redox environment modulates cardiogenic and ion-channel gene expression in cardiac-resident and non-resident mesenchymal stem cells

Cardiac Mesenchymal Stem Cell-like Cells Derived from a Young Patient with Bicuspid Aortic Valve Disease Have a Prematurely Aged Phenotype

There is significant interest in the role of stem cells in cardiac regeneration, and yet little is known about how cardiac disease progression affects native cardiac stem cells in the human heart. In this brief report, cardiac mesenchymal stem cell-like cells (CMSCLC) from the right atria of a 21-year-old female patient with a bicuspid aortic valve and aortic stenosis (referred to as biscuspid aortic valve disease BAVD-CMSCLC), were compared with those of a 78-year-old female patient undergoing coronary artery bypass surgery (referred to as coronary artery disease CAD-CMSCLC). Cells were analyzed for expression of MSC markers, ability to form CFU-Fs, metabolic activity, cell cycle kinetics, expression of NANOG and p16, and telomere length. The cardiac-derived cells expressed MSC markers and were able to form CFU-Fs, with higher rate of formation in CAD-CMSCLCs. BAVD-CMSCLCs did not display normal MSC morphology, had a much lower cell doubling rate, and were less metabolically active than CAD-CMSCLCs. Cell cycle analysis revealed a population of BAVD-CMSCLC in G2/M phase, whereas the bulk of CAD-CMSCLC were in the G0/G1 phase. BAVD-CMSCLC had lower expression of NANOG and shorter telomere lengths, but higher expression of p16 compared with the CAD-CMSCLC. In conclusion, BAVD-CMSCLC have a prematurely aged phenotype compared with CAD-CMSCLC, despite originating from a younger patient.

The application of umbilical cord-derived MSCs in cardiovascular diseases

Transplantation of stem cells is a promising, emerging treatment for cardiovascular diseases in the modern era. Mesenchymal stem cells (MSCs) derived from the umbilical cord are one of the most promising cell sources because of their capacity for differentiation into cardiomyocytes, endothelial cells and vascular smooth muscle cells in vitro/in vivo. In addition, umbilical cord‐derived MSCs (UC‐MSCs) secrete many effective molecules regulating apoptosis, fibrosis and neovascularization. Another important and specific characteristic of UC‐MSCs is their low immunogenicity and immunomodulatory properties. However, the application of UC‐MSCs still faces some challenges, such as low survivability and tissue retention in a harmful disease environment. Gene engineering and pharmacological studies have been implemented to overcome these difficulties. In this review, we summarize the differentiation ability, secretion function, immunoregulatory properties and preclinical/clinical studies of UC‐MSCs, highlighting the advantages of UC‐MSCs for the treatment of cardiovascular diseases.

Dissecting molecular mechanisms underlying H2O2-induced apoptosis of mouse bone marrow mesenchymal stem cell: role of Mst1 inhibition

BACKGROUND

Bone marrow mesenchymal stem cell (BM-MSC) has been shown to treat pulmonary arterial hypertension (PAH). However, excessive reactive oxygen species (ROS) increases the apoptosis of BM-MSCs, leading to poor survival and engraft efficiency. Thus, improving the ability of BM-MSCs to scavenge ROS may considerably enhance the effectiveness of transplantation therapy. Mammalian Ste20-like kinase 1 (Mst1) is a pro-apoptotic molecule which increases ROS production. The aim of this study is to uncover the underlying mechanisms the effect of Mst1 inhibition on the tolerance of BM-MSCs under H₂O₂ condition.

METHODS

Mst1 expression in BM-MSCs was inhibited via transfection with adenoviruses expressing a short hairpin (sh) RNA directed against Mst1 (Ad-sh-Mst1) and exposure to H₂O₂. Cell viability was detected by Cell Counting Kit 8 (CCK-8) assay, and cell apoptosis was analyzed by Annexin V-FITC/PI, Caspase 3 Activity Assay kits, and pro caspase 3 expression. ROS level was evaluated by the ROS probe DCFH-DA, mitochondrial membrane potential (ΔΨm) assay, SOD1/2, CAT, and GPx expression. Autophagy was assessed using transmission electron microscopy, stubRFP-sensGFP-LC3 lentivirus, and autophagy-related protein expression. The autophagy/Keap1/Nrf2 signal in H₂O₂-treated BM-MSC/sh-Mst1 was also measured.

RESULTS

Mst1 inhibition reduced ROS production; increased antioxidant enzyme SOD1/2, CAT, and GPx expression; maintained ΔΨm; and alleviated cell apoptosis in H₂O₂-treated BM-MSCs. In addition, this phenomenon was closely correlated with the autophagy/Keap1/Nrf2 signal pathway. Moreover, the antioxidant pathway Keap1/Nrf2 was also blocked when autophagy was inhibited by the autophagy inhibitor 3-MA. However, Keap1 or Nrf2 knockout via siRNA had no effect on autophagy activation or suppression.

CONCLUSION

Mst1 inhibition mediated the cytoprotective action of mBM-MSCs against H₂O₂-induced oxidative stress injury. The underlying mechanisms involve autophagy activation and the Keap1/Nrf2 signal pathway.

Effect of Stem Cells, Ascorbic Acid and SERCA1a Gene Transfected Stem Cells in Experimentally Induced Type I Diabetic Myopathy

Background and Objectives

Sarco/endoplasmic reticulum Ca^2＋-ATPase (SERCA) inhibition was proved in streptozotocin (STZ)-diabetic rats. The present study aimed at investigating and comparing the therapeutic effect of bone marrow mesenchymal stem cells (BMMSCs), BMMSCs combined with ascorbic acid (AA) and SERCA1a gene transfected BMMSCs in induced type I diabetic myopathy of male albino rat.

Methods and Results

54 rats were divided into donor group of 6 rats for isolation, propagation and characterization of BMMSCs and SERCA1a transfected BMMSCs, groups I∼V 48 rats. Group I of 8 control rats, group II (Diabetic) of 10 rats given STZ 50 mg/kg intraperitoneal, group III (BMMSCs) of 10 rats given STZ and BMMSCs intravenous (IV), group IV (BMMSCs and AA) of 10 rats given STZ, BMMSCs IV and AA 500 mg/kg and group V (SERCA 1a transfected BMMSCs) of 10 rats given STZ and SERCA1a transfected BMMSCs IV. The rats were sacrificed after 8 weeks. Gastrocnemius specimens were subjected to biochemical, histological, morphometric and statistical studies. Diabetic rats revealed inflammatory and degenerative muscle changes, a significant increase in blood glucose level, mean DNA fragmentation and mean MDA values and a significant decrease in mean GSH and catalase values, area of pale nuclei, area% of CD105 and CD34 ＋ve cells, SERCA1a protein and gene values. The morphological changes regressed by therapy. In group III significant decrease in DNA fragmentation and MDA, significant increase in GSH and catalase, significant increase in the mean area of pale nuclei, area % of CD105 and CD34 ＋ve cells versus diabetic group. In group IV, same findings as group III versus diabetic and BMMSCs groups. In group V, same findings as group IV versus diabetic and treated groups. Western blot and PCR proved a mean value of SERCA1a protein and gene comparable to the control group. Mean calcium concentration values revealed a significant increase in the diabetic group, in BMMSCs and AA group versus control and SERCA1a group.

Conclusions

SERCA1a transfected BMMSCs proved a definite therapeutic effect, more remarkable than BMMSCs combined with AA. This effect was evidenced histologically and confirmed by significant changes in the biochemical tests indicating oxidative stress, muscle calcium concentration, morphometric parameters and PCR values of SERCA1a.

Anti-oxidant effect of bergamot polyphenolic fraction counteracts doxorubicin-induced cardiomyopathy: Role of autophagy and c-kitposCD45negCD31neg cardiac stem cell activation

Doxorubicin (DOXO) is one of the most widely used antineoplastic drugs. Despite its highly beneficial effects against several malignancies, the clinical use of DOXO is often associated to cardiomyopathy that leads to congestive heart failure. Here we investigated the antioxidant and cardioprotective effects of a polyphenol-rich fraction of citrus bergamot (BPF), in DOXO-induced cardiac damage in rats. Moreover, we evaluated the effect of BPF on cardiomyocyte survival and resident endogenous cardiac stem/progenitor cell (eCSC) activation. Adult male Wistar rats were i.p. injected with saline (serving as controls, CTRL, n = 10), BPF (20 mg/kg daily for 14 consecutive days, n = 10), DOXO (6 doses of 2,5 mg/Kg from day 1 to day 14, n = 10), and DOXO + BPF (n = 10). Animals were then sacrificed 7 days later (i.e., at 21 days). DOXO administration reduced cardiac function at 21 days, an adverse effect significantly attenuated in animals receiving DOXO + BPF. No changes were detected in rats receiving just saline or BPF alone. The cardioprotective effect of BPF on DOXO acute toxicity was also associated with a significant antioxidant effect coupled with protective autophagy restoration, and attenuation of cardiomyocyte apoptosis and reactive hypertrophy. Finally, treatment of rats with BPF prevented eCSCs attrition by DOXO which was followed by a limited but significant increase of newly-formed BrdU⁺ cardiomyocytes. In conclusion, BPF reduces DOXO-induced cardiotoxicity by counteracting reactive oxygen species (ROS) overproduction, thereby restoring protective autophagy and attenuating cardiomyocyte apoptosis and pathologic remodeling. This beneficial effects on the early toxicity of DOXO is associated with enhanced CSCs survival and regenerative potential. Overall these data point to a potential clinical role by diet supplementation with polyphenol-rich fraction of citrus bergamot in counteracting antracycline-induced cardiomyopathy.

Skeletal Muscle Pathophysiology: The Emerging Role of Spermine Oxidase and Spermidine

Skeletal muscle comprises approximately 40% of the total body mass. Preserving muscle health and function is essential for the entire body in order to counteract chronic diseases such as type II diabetes, cardiovascular diseases, and cancer. Prolonged physical inactivity, particularly among the elderly, causes muscle atrophy, a pathological state with adverse outcomes such as poor quality of life, physical disability, and high mortality. In murine skeletal muscle C2C12 cells, increased expression of the spermine oxidase (SMOX) enzyme has been found during cell differentiation. Notably, SMOX overexpression increases muscle fiber size, while SMOX reduction was enough to induce muscle atrophy in multiple murine models. Of note, the SMOX reaction product spermidine appears to be involved in skeletal muscle atrophy/hypertrophy. It is effective in reactivating autophagy, ameliorating the myopathic defects of collagen VI-null mice. Moreover, spermidine treatment, if combined with exercise, can affect D-gal-induced aging-related skeletal muscle atrophy. This review hypothesizes a role for SMOX during skeletal muscle differentiation and outlines its role and that of spermidine in muscle atrophy. The identification of new molecular pathways involved in the maintenance of skeletal muscle health could be beneficial in developing novel therapeutic lead compounds to treat muscle atrophy.