Pinocembrin inhibited cardiomyocyte pyroptosis against doxorubicin-induced cardiac dysfunction via regulating Nrf2/Sirt3 signaling pathway

Abstract Background: Diabetic cardiomyopathy (DCM) severely impairs the health of diabetic patients. Previous studies have shown that the expression of inwardly rectifying potassium channel 6.1 (Kir6.1) in heart mitochondria is significantly reduced in type 1 diabetes. However, whether its expression and function are changed and what role it plays in type 2 DCM have not been reported. This study investigated the role and mechanism of Kir6.1 in DCM.Methods: The cardiac function in mice was analyzed by echocardiography, ELISA, hematoxylin and eosin staining, TUNEL and transmission electron microscopy. The mitochondrial function in cardiomyocytes was measured by the oxygen consumption rate and the mitochondrial membrane potential (ΔΨm). Kir6.1 expression at the mRNA and protein levels was analyzed by quantitative real-time PCR and western blotting (WB), respectively. The protein expression of t-AKT, p-AKT, t-Foxo1, and p-Foxo1 was analyzed by WB.Results: We found that the cardiac function and the Kir6.1 expression in DCM mice were decreased. Kir6.1 overexpression improved cardiac dysfunction and upregulated the phosphorylation of AKT and Foxo1 in the DCM mouse model. Furthermore, Kir6.1 overexpression also improved cardiomyocyte dysfunction and upregulated the phosphorylation of AKT and Foxo1 in cardiomyocytes with insulin resistance. In contrast, cardiac-specific Kir6.1 knockout aggravated the cardiac dysfunction and downregulated the phosphorylation of AKT and Foxo1 in DCM mice. Furthermore, Foxo1 activation downregulated the expression of Kir6.1 and decreased the ΔΨm in cardiomyocytes. In contrast, Foxo1 inactivation upregulated the expression of Kir6.1 and increased the ΔΨm in cardiomyocytes. Chromatin immunoprecipitation assay demonstrated that the Kir6.1 promoter region contains a functional Foxo1-binding site .Conclusions: Kir6.1 improves cardiac dysfunction in DCM, probably through the AKT-Foxo1 signaling pathway. Moreover, the crosstalk between Kir6.1 and the AKT-Foxo1 signaling pathway may provide new strategies for reversing the defective signaling in DCM.

Download Full-text

Stem Cell-Derived Exosomes Prevent Aging-Induced Cardiac Dysfunction through a Novel Exosome/lncRNA MALAT1/NF-κB/TNF-α Signaling Pathway

Oxidative Medicine and Cellular Longevity ◽

10.1155/2019/9739258 ◽

2019 ◽

Vol 2019 ◽

pp. 1-14 ◽

Cited By ~ 15

Author(s):

Bao Zhu ◽

Lulu Zhang ◽

Chun Liang ◽

Bin Liu ◽

Xiangbin Pan ◽

...

Keyword(s):

Stem Cell ◽

Signaling Pathway ◽

Cardiac Dysfunction ◽

Human Umbilical Cord ◽

Beneficial Effects ◽

Age Related ◽

Lncrna Malat1 ◽

Tnf Α ◽

Heart Functions

Aging is a risk factor for cardiovascular disease, and there is no effective therapeutic approach to alleviate this condition. NF-κB and TNF-α have been implicated in the activation of the aging process, but the signaling molecules responsible for the inactivation of NF-κB and TNF-α remain unknown. Exosomes have been reported to improve heart functions by releasing miRNA. Recent studies suggest that lncRNAs are more tissue-specific and developmental stage-specific compared to miRNA. However, the role of lncRNA in exosome-mediated cardiac repair has not been explored. In the present study, we focused on metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), which is an lncRNA associated with cell senescence. We discovered that human umbilical cord mesenchymal stem cell- (UMSC-) derived exosomes prevent aging-induced cardiac dysfunction. Silencer RNA against lncRNA MALAT1 blocked the beneficial effects of exosomes. In summary, we discovered that UMSC-derived exosomes prevent aging-induced cardiac dysfunction by releasing novel lncRNA MALAT1, which in turn inhibits the NF-κB/TNF-α signaling pathway. These findings will lead to the development of therapies that delay aging and progression of age-related diseases.

Download Full-text