Regulating Polyamine Metabolism by miRNAs in Diabetic Cardiomyopathy

The Associations of Dietary Polyamines with Incident Type 2 Diabetes Mellitus: A Large Prospective Cohort Study

OBJECTIVES

This study aimed to analyze the associations between dietary polyamine intake and incident T2DM.

METHODS

This prospective analysis included 168,137 participants from the UK Biobank who did not have T2DM at baseline. Dietary polyamines were calculated based on portion sizes of food items and a nutrient database. Incident T2DM was defined by hospital admissions with ICD10 codes E11-E14. Cox proportional hazard regression models and restricted cubic splines were used to examine the associations between dietary polyamine intake and incident T2DM.

RESULTS

During a median follow-up of 11.2 years (IQR, 11.8-13.2), 4422 (2.6%) participants developed T2DM. The average (SD) daily dietary intake was 10.5 (11.8) mg/day for spermidine, 4.3 (2.1) mg/day for spermine, and 12.7 (6.9) mg/day for putrescine. Compared to quintile 1, the multivariable-adjusted hazard ratios (95% CI) for quintiles 2-5 of dietary spermidine were 0.87 (0.79 to 0.96), 0.87 (0.79 to 0.96), 0.91 (0.82 to 0.99), and 0.96 (0.88 to 1.06); for dietary spermine, they were 1.01 (0.91 to 1.11), 1.03 (0.93 to 1.13), 1.07 (0.97 to 1.18), and 1.11 (1.01 to 1.23); and for dietary putrescine, they were 0.84 (0.76 to 0.92), 0.83 (0.79 to 0.91), 0.82 (0.74 to 0.90), and 0.87 (0.80 to 0.96).

CONCLUSIONS

Higher dietary spermidine and putrescine were associated with a lower risk of T2DM, while higher dietary spermine appeared to be associated with a higher risk of T2DM. These findings suggest optimal levels of dietary polyamine intake and indicate that polyamines may be promising targets for nutritional interventions in the prevention and management of T2DM.

Recent advances associated with cardiometabolic remodeling in diabetes-induced heart failure

Diabetes mellitus (DM) is characterized by chronic hyperglycemia, and despite intensive glycemic control, the risk of heart failure in patients with diabetes remains high. Diabetes-induced heart failure (DHF) presents a unique metabolic challenge, driven by significant alterations in cardiac substrate metabolism, including increased reliance on fatty acid oxidation, reduced glucose utilization, and impaired mitochondrial function. These metabolic alterations lead to oxidative stress, lipotoxicity, and energy deficits, contributing to the progression of heart failure. Emerging research has identified novel mechanisms involved in the metabolic remodeling of diabetic hearts, such as autophagy dysregulation, epigenetic modifications, polyamine regulation, and branched-chain amino acid (BCAA) metabolism. These processes exacerbate mitochondrial dysfunction and metabolic inflexibility, further impairing cardiac function. Therapeutic interventions targeting these pathways-such as enhancing glucose oxidation, modulating fatty acid metabolism, and optimizing ketone body utilization-show promise in restoring metabolic homeostasis and improving cardiac outcomes. This review explores the key molecular mechanisms driving metabolic remodeling in diabetic hearts, highlights advanced methodologies, and presents the latest therapeutic strategies for mitigating the progression of DHF. Understanding these emerging pathways offers new opportunities to develop targeted therapies that address the root metabolic causes of heart failure in diabetes.

MMP9 drives ferroptosis by regulating GPX4 and iron signaling

Ferroptosis, defined by the suppression of glutathione peroxidase-4 (GPX4) and iron overload, is a distinctive form of regulated cell death. Our in-depth research identifies matrix metalloproteinase-9 (MMP9) as a critical modulator of ferroptosis through its influence on GPX4 and iron homeostasis. Employing an innovative MMP9 construct without collagenase activity, we reveal that active MMP9 interacts with GPX4 and glutathione reductase, reducing GPX4 expression and activity. Furthermore, MMP9 suppresses key transcription factors (SP1, CREB1, NRF2, FOXO3, and ATF4), alongside GPX1 and ferroptosis suppressor protein-1 (FSP1), thereby disrupting the cellular redox balance. MMP9 regulates iron metabolism by modulating iron import, storage, and export via a network of protein interactions. LC-MS/MS has identified 83 proteins that interact with MMP9 at subcellular levels, implicating them in ferroptosis regulation. Integrated pathway analysis (IPA) highlights MMP9's extensive influence on ferroptosis pathways, underscoring its potential as a therapeutic target in conditions with altered redox homeostasis and iron metabolism.

Unveiling the hidden players: noncoding RNAs orchestrating polyamine metabolism in disease

Polyamines (PA) are polycations with pleiotropic functions in cellular physiology and pathology. In particular, PA have been involved in the regulation of cell homeostasis and proliferation participating in the control of fundamental processes like DNA transcription, RNA translation, protein hypusination, autophagy and modulation of ion channels. Indeed, their dysregulation has been associated to inflammation, oxidative stress, neurodegeneration and cancer progression. Accordingly, PA intracellular levels, derived from the balance between uptake, biosynthesis, and catabolism, need to be tightly regulated. Among the mechanisms that fine-tune PA metabolic enzymes, emerging findings highlight the importance of noncoding RNAs (ncRNAs). Among the ncRNAs, microRNA, long noncoding RNA and circRNA are the most studied as regulators of gene expression and mRNA metabolism and their alteration have been frequently reported in pathological conditions, such as cancer progression and brain diseases. In this review, we will discuss the role of ncRNAs in the regulation of PA genes, with a particular emphasis on the changes of this modulation observed in health disorders.

Transglutaminase 2 in diabetes mellitus: Unraveling its multifaceted role and therapeutic implications for vascular complications

Diabetes, a severe metabolic disease characterized by chronic hypoglycemia, poses debilitating and life-threatening risks of microvascular and macrovascular complications, including blindness, kidney failure, heart attacks, and limb amputation. Addressing these complications is paramount, urging the development of interventions targeting diabetes-associated vascular dysfunctions. To effectively combat diabetes, a comprehensive understanding of the pathological mechanisms underlying complications and identification of precise therapeutic targets are imperative. Transglutaminase 2 (TGase2) is a multifunctional enzyme implicated in the pathogenesis of diverse diseases such as neurodegenerative disorders, fibrosis, and inflammatory conditions. TGase2 has recently emerged as a key player in both the pathogenesis and therapeutic intervention of diabetic complications. This review highlights TGase2 as a therapeutic target for diabetic complications and explores TGase2 inhibition as a promising therapeutic approach in their treatment.

Cardiac Metabolism and MiRNA Interference

The aberrant increase in cardio-metabolic diseases over the past couple of decades has drawn researchers' attention to explore and unveil the novel mechanisms implicated in cardiometabolic diseases. Recent evidence disclosed that the derangement of cardiac energy substrate metabolism plays a predominant role in the development and progression of chronic cardiometabolic diseases. Hence, in-depth comprehension of the novel molecular mechanisms behind impaired cardiac metabolism-mediated diseases is crucial to expand treatment strategies. The complex and dynamic pathways of cardiac metabolism are systematically controlled by the novel executor, microRNAs (miRNAs). miRNAs regulate target gene expression by either mRNA degradation or translational repression through base pairing between miRNA and the target transcript, precisely at the 3' seed sequence and conserved heptametrical sequence in the 5' end, respectively. Multiple miRNAs are involved throughout every cardiac energy substrate metabolism and play a differential role based on the variety of target transcripts. Novel theoretical strategies have even entered the clinical phase for treating cardiometabolic diseases, but experimental evidence remains inadequate. In this review, we identify the potent miRNAs, their direct target transcripts, and discuss the remodeling of cardiac metabolism to cast light on further clinical studies and further the expansion of novel therapeutic strategies. This review is categorized into four sections which encompass (i) a review of the fundamental mechanism of cardiac metabolism, (ii) a divulgence of the regulatory role of specific miRNAs on cardiac metabolic pathways, (iii) an understanding of the association between miRNA and impaired cardiac metabolism, and (iv) summary of available miRNA targeting therapeutic approaches.