Therapeutic effect of adipose-derived stem cells injected into pericardial cavity in rat heart failure.

AIMS: There are few studies on the treatment of heart failure by injecting stem cells into the pericardial cavity. Can the cells injected into the pericardial cavity migrate through the epicardium to the myocardial tissue? Whether there is therapeutic effect and the mechanism of therapeutic effect are still unclear. This study investigated the therapeutic efficacy and evidence of cell migration of adipose-derived stem cells (ADSCs) injected into the pericardial cavity in rat heart failure. The aim of this study is to demonstrate the effectiveness and mechanism of treating heart failure by injecting stem cells into the pericardial cavity, laying an experimental foundation for a new approach to stem cell therapy for heart disease in clinical practice. METHODS AND RESULTS: The inguinal adipose tissue of male SD rats aged 4-6 weeks was taken, ADSCs were isolated and cultured, and their stem cell surface markers were identified. Forty rats aged 6-8 weeks were divided into sham operation group, heart failure group, and treatment group; there were 15 rats in the heart failure group and 15 rats in the treatment group. The heart failure model was established by intraperitoneal injection of adriamycin hydrochloride. The heart function of the three groups was detected by small animal ultrasound. The model was successful if the left ventricular ejection fraction < 50%. The identified ADSCs were injected into the pericardial cavity of rats in the treatment group. The retention of transplanted cells in pericardial cavity was detected by small animal in vivo imaging instrument, and the migration of transplanted cells into myocardial tissue was observed by tissue section and immunofluorescence. Western blotting and immunohistochemical staining were used to detect brain natriuretic peptide (BNP), α-smooth muscle actin (α-SMA), and C-reactive protein (CRP). ADSCs express CD29, CD44, and CD73. On the fourth day after injection of ADSCs into pericardial cavity, they migrated to myocardial tissue through epicardium and gradually diffused to deep myocardium. The cell density in the pericardial cavity remains at a high level for 10 days after injection and gradually decreases after 10 days. Compared with the heart failure group, the expression of BNP and α-SMA decreased (P < 0.05 and P < 0.001, respectively), and the expression of CRP in the treatment group was higher than that in the heart failure group (P < 0.0001). A small amount of BNP, α-SMA, and CRP was expressed in the myocardium of the sham operation group. After injection of ADSCs, interleukin-6 in myocardial tissue was significantly lower than that in heart failure myocardium (P < 0.01). After treatment, vascular endothelial growth factor A was significantly higher than that of heart failure (P < 0.01). CONCLUSIONS: Pericardial cavity injected ADSCs can penetrate the epicardium, migrate into the myocardium, and have a therapeutic effect on heart failure. Their mechanism of action is to exert therapeutic effects through anti-inflammatory, anti-fibrosis, and increased angiogenesis.

Drug-induced lactate confers ferroptosis resistance via p38-SGK1-NEDD4L-dependent upregulation of GPX4 in NSCLC cells.

Ferroptosis is a newly defined non-apoptotic programmed cell death resulting from the accumulation of lipid peroxides. Whether ferroptosis plays any role in chemotherapy remains to be established. Here, we reported that ferroptosis represents a part of the chemotherapeutic drug etoposide-induced cell death response in Small Cell Lung Cancer (SCLC) cells and adaptive signaling molecule lactate protects Non-Small Cell Lung Cancer (NSCLC) from etoposide-induced ferroptosis. Lactate derived from metabolic reprogramming increases the expression of glutathione peroxidase 4 (GPX4) to promote ferroptosis resistance in NSCLC. Furthermore, we identified E3-ubiquitin ligase NEDD4L as a major regulator of GPX4 stability. Mechanistically, Lactate increases mitochondrial ROS generation and drives activation of the p38-SGK1 pathway, which attenuates the interaction of NEDD4L with GPX4 and subsequent ubiquitination and degradation of GPX4. Our data implicated the role of ferroptosis in chemotherapeutic resistance and identified a novel post-translational regulatory mechanism for the key Ferroptosis mediator GPX4.

Urolithin A Inhibits Epithelial-Mesenchymal Transition in Lung Cancer Cells via P53-Mdm2-Snail Pathway.

PURPOSE: The epithelial-to-mesenchymal transition (EMT) is a fundamental process in tumor progression that endows cancer cells with migratory and invasive potential. Snail, a zinc finger transcriptional repressor, plays an important role in the induction of EMT by directly repressing the key epithelial marker E-cadherin. Here, we assessed the effect of urolithin A, a major metabolite from pomegranate ellagitannins, on Snail expression and EMT process. METHODS: The role of Snail in urolithin A-induced EMT inhibition in lung cancer cells was explored by wound healing assay and cell invasion assay. The qRT-PCR and CHX assay were performed to investigate how urolithin A regulates Snail expression. Immunoprecipitation assays were established to determine the effects of urolithin A in mdm2-Snail interaction. In addition, the expression of p53 was manipulated to explore its effect on the expression of mdm2 and Snail. RESULTS: The urolithin A dose-dependently upregulated epithelial marker and decreased mesenchymal markers in lung cancer cells. In addition, exposure to urolithin A decreased cell migratory and invasive capacity. We have further demonstrated that urolithin A inhibits lung cancer cell EMT by decreasing Snail protein expression and activity. Mechanistically, urolithin A disrupts the interaction of p53 and mdm2 which leads Snail ubiquitination and degradation. CONCLUSION: We conclude that urolithin A could inhibit EMT process by controlling mainly Snail expression. These results highlighted the role of pomegranate in regulation of EMT program in lung cancer.