Loss of ALDH2 aggravates mitochondrial biogenesis disorder in cardiac myocytes induced by TAC

A prognostic model of idiopathic pulmonary fibrosis constructed based on macrophage and mitochondria-related genes

BACKGROUND

Studies have shown that mitochondrial function and macrophages may play a role in the development of idiopathic pulmonary fibrosis (IPF). However, the understanding of the interactions and specific mechanisms between mitochondrial function and macrophages in pulmonary fibrosis is still very limited.

METHODS

To construct a prognostic model for IPF based on Macrophage- related genes (MaRGs) and Mitochondria-related genes (MitoRGs), differential analysis was performed to achieve differentially expressed genes (DEGs) between IPF and Control groups in the GSE28042 dataset. Then, MitoRGs, MaRGs and DEGs were overlapped to screen out the signature genes. The univariate Cox analysis and the least absolute shrinkage and selection operator (LASSO) algorithm were implemented to achieve key genes. Furthermore, the independent prognostic analysis was employed. The ingenuity pathway analysis (IPA) was employed to further understand the molecular mechanisms of key genes.Next, the immune infiltration analysis was implemented to identify differential immune cells between two risk subgroups.

RESULTS

There were 4791 DEGs between IPF and Control groups. Furthermore, 26 signature genes were achieved by the intersection processing. Three key genes including ALDH2, MCL1, and BCL2A1 were achieved, and the risk model based on the key genes was created. In addition, a nomogram for survival forecasting of IPF patients was created based on riskScore, Age, and Gender, and we found that key genes were associated with classical pathways including 'Apoptosis Signaling', 'PI3K/AKT Signaling', and so on. Next, two differential immune cells including Monocytes and CD8 T cells were identified between two risk subgroups. Moreover, we found that MIR29B2CHG and hsa-mir-1-3p could regulate the expression of ALDH2.

CONCLUSION

We achieved 3 key genes including ALDH2, MCL1,, and BCL2A1 associated with IPF, providing a new theoretical basis for clinical treatment of IPF.

Ginsenoside Rd attenuates myocardial ischemia injury through improving mitochondrial biogenesis via WNT5A/Ca2+ pathways

Ginsenoside Rd, one of the main active components in ginseng, exerts various biological activities. However, its effectiveness on myocardial ischemia injury and its potential mechanism need further clarification. The model of isoproterenol (ISO)-induced myocardial ischemia injury (MI) mice and cobalt chloride (CoCl2)-induced cardiomyocytes injury were performed. Ginsenoside Rd significantly alleviated MI injury, as evidenced by ameliorated cardiac pathological features and improved cardiac function. Simultaneously, ginsenoside Rd notably mitigated CoCl2-induced cell injury, decreased the lactate dehydrogenase (LDH) release and reactive oxygen species (ROS) generation in vitro. Additionally, ginsenoside Rd increased nicotinamide adenine dinucleotide (NADH) and mitochondrial membrane potential (MMP). Moreover, we found that ginsenoside Rd could increase the mitochondrial DNA (mtDNA) and promote the expression of Peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC1α), nuclear factor erythroid 2 related factor-1 (NRF1), nuclear factor erythroid 2 related factor-2 (NRF2) and activating mitochondrial transcription factor A (TFAM), which suggested that ginsenoside Rd might accelerate mitochondrial biogenesis function to ameliorate MI injury. Importantly, ginsenoside Rd treatment significantly inhibited the WNT5A/calcium (Ca2+) signaling pathway, decreased the expression of WNT5A, Frizzled2, phosphorylated calmodulin kinase II/calmodulin kinase II (p-CaMKII/CaMKII) and the calcium overload. Meanwhile, WNT5A siRNA was further conducted to elucidate the effect of ginsenoside Rd on CoCl2-induced cardiomyocyte injury. And we found that WNT5A siRNA partially weakened the protective effects of ginsenoside Rd on mitochondrial function and mitochondrial biogenesis, suggesting that ginsenoside Rd might suppress myocardial ischemia injury through WNT5A. Overall, this study demonstrated that ginsenoside Rd could alleviate myocardial ischemia injury through improving mitochondrial biogenesis via WNT5A/Ca2+ pathways, which provided a rationale for future clinical applications and potential drugs for the treatment of cardiovascular diseases.

Commentary: Aldehyde dehydrogenase, redox balance and exercise physiology: What is missing?

Aldehyde dehydrogenase 2 (ALDH2) is a mitochondrial enzyme involved in reactive aldehyde detoxification. Approximately 560 million people (about 8% of the world's population) carry a point mutation in the aldehyde dehydrogenase 2 gene (ALDH2), identified as ALDH2*2, which leads to decreased ALDH2 catalytic activity. ALDH2*2 variant is associated with an accumulation of toxic reactive aldehydes and consequent disruption of cellular metabolism, which contributes to the establishment and progression of several degenerative diseases. Consequences of aldehyde accumulation include impaired mitochondrial functional, hindered anabolic signaling in the skeletal muscle, impaired cardiovascular and pulmonary function, and reduced osteoblastogenesis. Considering that aldehydes are endogenously produced through redox processes, it is expected that conditions that have a high energy demand, such as exercise, might be affected by impaired aldehyde clearance in ALDH2*2 individuals. Despite the large body of evidence supporting the importance of ALDH2 to ethanol metabolism, redox homeostasis and overall health, specific research investigating the impact of ALDH2*2 on phenotypes relevant to exercise performance are notoriously scarce. In this commentary, we highlight the consolidated knowledge on the impact of ALDH2*2 on physiological processes that are relevant to exercise.

Cellular and molecular biology of sirtuins in cardiovascular disease

Sirtuins (SIRTs) are a nicotinic adenine dinucleotide (+) -dependent histone deacetylase that regulates critical signaling pathways in prokaryotes and eukaryotes. Studies have identified seven mammalian homologs of the yeast SIRT silencing message regulator 2, namely, SIRT1-SIRT7. Recent in vivo and in vitro studies have successfully demonstrated the involvement of SIRTs in key pathways for cell biological function in physiological and pathological processes of the cardiovascular system, including processes including cellular senescence, oxidative stress, apoptosis, DNA damage, and cellular metabolism. Emerging evidence has stimulated a significant evolution in preventing and treating cardiovascular disease (CVD). Here, we review the important roles of SIRTs for the regulatory pathways involved in the pathogenesis of cardiovascular diseases and their molecular targets, including novel protein post-translational modifications of succinylation. In addition, we summarize the agonists and inhibitors currently identified to target novel specific small molecules of SIRTs. A better understanding of the role of SIRTs in the biology of CVD opens new avenues for therapeutic intervention with great potential for preventing and treating CVD.

Integrating strategies of metabolomics, network pharmacology, and experiment validation to investigate the processing mechanism of Epimedium fried with suet oil to warm kidney and enhance yang

Introduction: Epimedium, a traditional Chinese medicine (TCM) commonly used in ancient and modern China, is one of the traditional Chinese medicines clinically used to treat kidney yang deficiency syndrome (KYDS). There are differences in the efficacy of Epimedium before and after processing, and the effect of warming the kidney and enhancing yang is significantly enhanced after heating with suet oil. However, the active compounds, corresponding targets, metabolic pathways, and synergistic mechanism of frying Epimedium in suet oil to promote yang, remain unclear. Methods: Herein, a strategy based on comprehensive GC-TOF/MS metabolomics and network pharmacology analysis was used to construct an "active compounds-targets-metabolic pathways" network to identify the active compounds, targets and metabolic pathways involved. Subsequently, the targets in kidney tissue were further validated by real-time quantitative polymerase chain reaction (RT-qPCR). Histopathological analysis with physical and biochemical parameters were performed. Results: Fifteen biomarkers from urine and plasma, involving five known metabolic pathways related to kidney yang deficiency were screened. The network pharmacology results showed 37 active compounds (13 from Epimedium and 24 from suet oil), 159 targets, and 267 pathways with significant correlation. Importantly, integrated metabolomics and network pharmacologic analysis revealed 13 active compounds (nine from Epimedium and four from suet oil), 7 corresponding targets (ALDH2, ARG2, GSTA3, GSTM1, GSTM2, HPGDS, and NOS2), two metabolic pathways (glutathione metabolism, arginine and proline metabolism), and two biomarkers (Ornithine and 5-Oxoproline) associated with improved kidney yang deficiency by Epimedium fried with suet oil. Discussion: These finds may elucidate the underlying mechanism of yang enhancement via kidney warming effects. Our study indicated that the mechanism of action mainly involved oxidative stress and amino acid metabolism. Here, we demonstrated the novel strategies of integrating metabolomics and network pharmacology in exploring of the mechanisms of traditional Chinese medicines.