DHODH Alleviates Heart Failure via the Modulation of CoQ-Related Ferroptotic Inhibition.

BACKGROUND: Heart failure (HF) is a clinical syndrome that seriously endangers human health and quality of life as the terminal stage of cardiovascular diseases. Ferroptosis as a new iron-dependent programmed cell death mode that is closely related to the occurrence and development of cardiovascular diseases. Dihydroorotate dehydrogenase (DHODH) has been found to play a crucial role in inhibiting ferroptosis and improving mitochondrial function, and its expression can be upregulated by estradiol (E2). Recent studies have found that DHODH can inhibit ferroptosis by reducing coenzyme Q (CoQ) to CoQH2. Therefore, this study aims to explore the effect of up-regulation of DHODH on the pathological hypertrophy and fibrosis of heart failure and its mechanisms. METHODS: The mouse heart failure model was established by transverse aortic constriction (TAC), surgery in mice. Two days after the operation, a subcutaneous injection of E2 or the same volume of sesame oil was given for 8 weeks. Then, the left ventricular systolic function related indicators of mice were measured by echocardiography, and the degree of myocardial fibrosis of mice was detected by histological analysis; the expression levels of heart failure markers were detected by quantitative polymerase chain reaction (q-PCR) and western blot (WB) analysis; the morphological changes of mitochondria in cardiac cells of mice were observed by transmission electron microscopy. Cell model were established by stimulating with phenylephrine for 96 hours. Ferroptosis markers were detected by kits and WB analysis. Mitochondrial function was verified by a JC-1 fluorescent probe, and 2',7'-Dichlorodihydrofluorescein diacetate (DCFH-DA) staining. The knockdown results were detected by WB analysis after transfection of small interfering RNA (siRNA) of CoQ. Fer-1 was added as a positive control to verify the ferroptosis-related changes of myocardial cells. RESULTS: In the animal model, we found that E2 treatment alleviates TAC-induced cardiac hypertrophy and fibrosis and suppresses cardiomyocyte ferroptosis by promotes DHODH upregulation in murine cardiomyocytes. In the cell model, DHODH upregulation protects against phenylephrine-induced cardiomyocytes with failure. However, the effect on up-regulating DHODH was inhibited by transfection to down-regulate CoQ expression. CONCLUSIONS: The up-regulation of DHODH could effectively ameliorate the manifestations of heart failure such as myocardial hypertrophy and fibrosis in mice after TAC surgery, inhibit ferroptosis of cardiac myocytes, and ameliorate mitochondrial function. The mechanism involves CoQ-related biological processes.

Establishment of Ferroptosis-Associated Molecular Subtypes and Hub Genes Related to the Immune Microenvironment of Heart Failure.

BACKGROUND: Ferroptosis is a form of iron-dependent regulated cell death, and prior work has highlighted the potential utility of ferroptosis-inducing agents as tools to treat heart failure (HF). To date, however, no detailed examinations of the prognostic utility of ferroptosis-related genes (FRGs) in HF have been conducted. METHODS: We used established genomic identification of FRGs for total samples in the gene expression omnibus (GEO) database, screened for differentially expressed FRGs, performed protein-protein interaction analysis and functional analysis of HF immune microenvironment subtypes. Subsequently, we applied tools to calculate immune cell infiltration, compare immune cell, immune response genomic and HLA gene differences between subtypes, and perform candidate drug identification. Finally, preliminary in vivo validation of the screened central genes was performed in animal models. RESULTS: FRGs were compared between samples from HF and healthy control donors, revealing 62 of these genes to be differentially expressed as a function of HF status. HF patient-derived tissues exhibited significant changes in the expression of HLA genes, increase immune cell infiltration, and higher levels of other immune-related genes within the associated immune microenvironment. These FRGs were then leveraged to establish two different immune-related subtypes of HF based on clustering analysis results, after which these subtypes were characterized in further detail. Functional enrichment analyses revealed the identified differentially expressed genes to be enriched in key immune-related pathways including the primary immunodeficiency, natural killer cell-mediated cytotoxicity, FcϵRI signaling, and antigen processing and presentation pathways. The impact of the immune microenvironment was also explored through functional analyses, core gene analyses, and efforts to identify potential drug candidates for HF patients. Moreover, four key hub genes were identified as promising targets for therapeutic intervention in HF, including HDAC1, LNPEP, PSMA1, and PSMA6. Subsequent preclinical work in a mouse model system supported a potential role for HDAC1 as an important biomarker associated with the incidence of HF. CONCLUSIONS: To sum up, these results emphasize the importance of ferroptosis as a regulator of the HF-related immune microenvironment, highlighting viable avenues for the further study of molecular targets amenable to pharmacological intervention with the aim of treating this debilitating disease.