Adiponectin inhibits D‑gal‑induced cardiomyocyte senescence via AdipoR1/APPL1

METTL14-mediated N6-methyladenosine modification induces the ferroptosis of hypoxia/reoxygenation-induced cardiomyocytes

BACKGROUND

Hypoxia/reoxygenation (H/R) induces cardiomyocyte ferroptosis, a core remodeling event in myocardial ischemia/reperfusion injury. Methyltransferase-like 14 (METTL14) emerges as a writer of N6-methyladenosine (m6A) modification. This study was conducted to decipher the role of METTL14 in H/R-induced cardiomyocyte ferroptosis.

METHODS

Mouse cardiomyocytes HL-1 were cultured and underwent H/R treatment. The degree of ferroptosis after H/R treatment was appraised by the cell counting kit-8 assay, assay kits (ROS/GSH/Fe2+), and Western blotting (GPX4/ACSL4). The intracellular expressions of METTL14, pri-miR-146a-5p, miR-146a-5p, or adaptor protein phosphotyrosine interacting with PH domain and leucine zipper 1 (APPL1) were examined by real-time quantitative polymerase chain reaction or Western blotting, with m6A quantification analysis and RNA immunoprecipitation to determine the total m6A level and the expression of pri-miR-146a-5p bound to DiGeorge critical region 8 (DGCR8) and m6A-modified pri-miR-146a-5p. The binding of miR-146a-5p to APPL1 was testified by the dual-luciferase assay.

RESULTS

H/R treatment induced cardiomyocyte ferroptosis (increased ROS, Fe2+, and ACSL4 and decreased GSH and GPX4) and upregulated METTL14 expression. METTL14 knockdown attenuated H/R-induced cardiomyocyte ferroptosis. METTL14 induced the recognition of pri-miR-146a-5p by DGCR8 by increasing m6A modification on pri-miR-146a-5p, which promoted the conversion of pri-miR-146a-5p into miR-146a-5p and further repressed APPL1 transcription. miR-146a-5p upregulation or APPL1 downregulation limited the inhibitory effect of METTL14 downregulation on H/R-induced cardiomyocyte ferroptosis.

CONCLUSION

METTL14 promoted miR-146a-5p expression through the recognition and processing of pri-miR-146a-5p by DGCR8, which repressed APPL1 transcription and triggered H/R-induced cardiomyocyte ferroptosis.

Resistance training up-regulates Smyd1 expression and inhibits oxidative stress and endoplasmic reticulum stress in the heart of middle-aged mice

Persistent oxidative stress and endoplasmic reticulum (ER) stress are the primary mechanisms of age-related cardiovascular diseases. Although exercise training is viewed as an effective anti-aging approach, further exploration is needed to identify the mechanisms and functional targets. In this study, the impact of resistance training (RT) on the expression of Smyd1, the levels of reactive oxygen species (ROS) and the expression of ER stress-related protein in the hearts of mice of different ages were assessed. In addition, the role of Smyd1 in the aging-induced oxidative stress and ER stress were evaluated in d-galactose (D-gal)-treated H9C2 cells. We demonstrated that RT in middle age increased the expression of Smyd1 and restricted heart aging-induced ER stress. Overexpression of Smyd1 restrained oxidative stress and ER stress in D-gal-treated H9C2 cells, while the inhibition of Nrf2 and Smyd1 escalated ER stress. These findings demonstrate that Smyd1 has significant impact in regulating age-related ER stress. RT in middle age can up-regulates Smyd1 expression and inhibits oxidative stress and ER stress in the heart.

Traffic Density Exposure, Oxidative Stress Biomarkers and Plasma Metabolomics in a Population-Based Sample: The Hortega Study

Exposure to traffic-related air pollution (TRAP) generates oxidative stress, with downstream effects at the metabolic level. Human studies of traffic density and metabolomic markers, however, are rare. The main objective of this study was to evaluate the cross-sectional association between traffic density in the street of residence with oxidative stress and metabolomic profiles measured in a population-based sample from Spain. We also explored in silico the potential biological implications of the findings. Secondarily, we assessed the contribution of oxidative stress to the association between exposure to traffic density and variation in plasma metabolite levels. Traffic density was defined as the average daily traffic volume over an entire year within a buffer of 50 m around the participants' residence. Plasma metabolomic profiles and urine oxidative stress biomarkers were measured in samples from 1181 Hortega Study participants by nuclear magnetic resonance spectroscopy and high-performance liquid chromatography, respectively. Traffic density was associated with 7 (out of 49) plasma metabolites, including amino acids, fatty acids, products of bacterial and energy metabolism and fluid balance metabolites. Regarding urine oxidative stress biomarkers, traffic associations were positive for GSSG/GSH% and negative for MDA. A total of 12 KEGG pathways were linked to traffic-related metabolites. In a protein network from genes included in over-represented pathways and 63 redox-related candidate genes, we observed relevant proteins from the glutathione cycle. GSSG/GSH% and MDA accounted for 14.6% and 12.2% of changes in isobutyrate and the CH2CH2CO fatty acid moiety, respectively, which is attributable to traffic exposure. At the population level, exposure to traffic density was associated with specific urine oxidative stress and plasma metabolites. Although our results support a role of oxidative stress as a biological intermediary of traffic-related metabolic alterations, with potential implications for the co-bacterial and lipid metabolism, additional mechanistic and prospective studies are needed to confirm our findings.

Membrane progesterone receptors on the cell membrane: A review highlighting potential export motifs in mPRα regulating its trafficking to the cell surface

Substantial progress has been made in our understanding of the nongenomic actions, ligand binding, intracellular signaling pathways, and functions of membrane progesterone receptors (mPRs) in reproductive and nonreproductive tissues since their discovery 20 years ago. The five mPRs are members of the progestin adipoQ receptor (PAQR) family which also includes adiponectin receptors (AdipoRs). However, unlike AdipoRs, the 3-D structures of mPRs are unknown, and their structural characteristics remain poorly understood. The mechanisms regulating mPR functions and their trafficking to the cell surface have received little attention and have not been systematically reviewed. This paper summarizes some structural aspects of mPRs, including the ligand binding pocket of mPRα recently derived from homology modeling with AdipoRs, and the proposed topology of mPRs from the preponderance of positively charged amino acid residues in their intracellular domains. The mechanisms of trafficking membrane receptors to the cell surface are discussed, including the amino acid motifs involved with their export to the cell surface, the roles of adaptor proteins, and post-translational glycosylation and palmitoylation modifications that promote cell surface expression and retention. Evidence for similar mechanisms regulating the expression and functions of mPRs on the cell surface is discussed, including the identification of potential export motifs on mPRα required for its trafficking to the cell membrane. Collectively, these results have identified several potential mechanisms regulating the expression and functions of mPRs on the cell membrane for further investigation.

Shared signaling pathways and targeted therapy by natural bioactive compounds for obesity and type 2 diabetes

Epidemiological evidence showed that patients suffering from obesity and T2DM are significantly at higher risk for chronic low-grade inflammation, oxidative stress, nonalcoholic fatty liver (NAFLD) and intestinal flora imbalance. Increasing evidence of pathological characteristics illustrates that some common signaling pathways participate in the occurrence, progression, treatment, and prevention of obesity and T2DM. These signaling pathways contain the pivotal players in glucose and lipid metabolism, e.g., AMPK, PI3K/AKT, FGF21, Hedgehog, Notch, and WNT; the inflammation response, for instance, Nrf2, MAPK, NF- kB, and JAK/STAT. Bioactive compounds from plants have emerged as key food components related to healthy status and disease prevention. They can act as signaling molecules to initiate or mediate signaling transduction that regulates cell function and homeostasis to repair and re-functionalize the damaged tissues and organs. Therefore, it is crucial to continuously investigate bioactive compounds as sources of new pharmaceuticals for obesity and T2DM. This review provides comprehensive information of the commonly shared signaling pathways between obesity and T2DM, and we also summarize the therapeutic bioactive compounds that may serve as anti-obesity and/or anti-diabetes therapeutics by regulating these associated pathways, which contribute to improving glucose and lipid metabolism, attenuating inflammation.

ER stress in cardiac aging, a current view on the D-galactose model

Longitudinal studies are mandatory to study aging, however, they have certain drawbacks, for example, they require strict maintenance that is expensive given the breeding time (approximately 2 years) and with a low survival rate, having some animals to study very limitedly. In vitro studies provide useful and invaluable information on the cellular and molecular mechanisms that help understand the aging process to overcome these aspects. In particular, the model of premature aging induced by chronic exposure to D-galactose (D-Gal) offers a very similar picture to that which occurs in natural aging. This model mimics most of the old animals' cellular processes, such as oxidative stress, mitochondrial dysfunction, increased advanced glycation end products (AGEs), inflammation, and senescence-associated secretory phenotype (SASP). However, the information related to the endoplasmic reticulum (ER) stress and, subsequently, the unfolded protein response (UPR) is not fully elucidated. Therefore, this review brings together the most current information on this response in the D-Gal-induced aging model and its effect on cardiac structure and function.

D-galactose-induced cardiac ageing: A review of model establishment and potential interventions

Cardiovascular disease (CVD) is highly prevalent in an ageing society. The increased incidence and mortality rates of CVD are global issues endangering human health. There is an urgent requirement for understanding the aetiology and pathogenesis of CVD and developing possible interventions for preventing CVD in ageing hearts. It is necessary to select appropriate models and treatment methods. The D‐galactose‐induced cardiac ageing model possesses the advantages of low mortality, short time and low cost and has been increasingly used in the study of cardiovascular diseases in recent years. Therefore, understanding the latest progress in D‐galactose‐induced cardiac ageing is valuable. This review highlights the recent progress and potential therapeutic interventions used in D‐galactose‐induced cardiac ageing in recent years by providing a comprehensive summary of D‐galactose‐induced cardiac ageing in vivo and in vitro. This review may serve as reference literature for future research on age‐related heart diseases.