Mechanisms of diabetic cardiomyopathy: Focus on inflammation

Interaction between mitochondrial oxidative stress and myocardial fibrosis in the context of diabetes

Diabetes represents a global chronic health issue and has emerged as a crucial risk factor for cardiovascular diseases (CVD). Myocardial fibrosis (MF), which often accompanies diabetes, plays a pivotal role in the progression of cardiac dysfunction and heart failure (HF). Recent research has highlighted mitochondrial oxidative stress (OS) as a fundamental mechanism driving MF in diabetic conditions. Elevated blood glucose levels and metabolic imbalances lead to mitochondrial impairments, which in turn cause an excessive buildup of reactive oxygen species (ROS), culminating in OS. This OS not only inflicts direct damage on myocardial cells but also facilitates the proliferation of myocardial fibroblasts and collagen accumulation through the activation of specific signaling pathways, thus intensifying MF. Furthermore, MF itself intensifies mitochondrial OS, creating a vicious cycle that ultimately impairs myocardial structure and function. Thus, a thorough understanding of the interaction between mitochondrial OS and MF in diabetes is crucial for identifying effective therapeutic targets and enhancing the early diagnosis and intervention strategies for diabetic cardiomyopathy.

Ranolazine as a therapeutic agent for diabetic cardiomyopathy: reducing endoplasmic reticulum stress and inflammation in type 2 diabetic rat model

BACKGROUND

Diabetic cardiomyopathy (DCM) is a significant cardiovascular complication of diabetes, characterized by structural and functional heart muscle dysfunction. Oxidative stress, endoplasmic reticulum (ER) stress, and inflammation are pivotal in the pathogenesis of DCM. Ranolazine, primarily used for angina, has demonstrated potential cardioprotective effects. This study investigates the effects of ranolazine on oxidative stress, ER stress, and inflammation in the heart tissue of type 2 diabetic rats.

METHODS

Diabetes was induced in male Wistar rats using Nicotinamide (110 mg/kg) and Streptozotocin (60 mg/kg). The rats were then divided into control and diabetic groups, with further subdivision into ranolazine-treated and untreated subgroups. Ranolazine was administered via gavage for eight weeks. Various parameters, including body weight, heart weight, serum glucose, troponin-I levels, oxidative stress markers, ER stress markers, and inflammatory markers, were assessed.

RESULTS

Diabetic rats showed increased heart weight and decreased body weight over eight weeks. Ranolazine treatment improved body weight but didn't affect serum glucose levels. The treatment significantly lowered serum troponin-I and oxidative stress markers, increased superoxide dismutase (SOD) and glutathione (GSH) levels, and decreased malondialdehyde (MDA) concentrations. Additionally, ranolazine reduced the expression of stress-related genes (GRP78, XBP1, and NLRP3) and lowered serum IL1β levels.

CONCLUSIONS

The results indicate that ranolazine protects against DCM by attenuating oxidative stress, ER stress, and inflammation. Its potential as a therapeutic agent for DCM warrants further investigation.

Heart failure, inflammation and exercise

Heart failure (HF) is a condition characterized by high morbidity, mortality, and a substantial healthcare burden, in which inflammation plays a pivotal role. This review provides a comprehensive overview of inflammation in HF progression, highlighting the dynamic alterations in immune cell populations-such as monocytes/macrophages and neutrophils-and regulatory mechanisms of key signaling pathways, including JAK and NLRP3. Furthermore, the clinical relevance of inflammatory biomarkers in predicting disease prognosis is also discussed. Emerging evidence indicates that exercise intervention can enhance cardiac function by promoting the expression of anti-inflammatory cytokines (e.g., IL-10) and mitigating myocardial fibrosis, oxidative stress, and apoptosis. Future studies should investigate how exercise modulates critical inflammatory pathways-such as TLR/MyD88/NF-κB and the NLRP3 inflammasome-and aim to establish personalized exercise protocols tailored to patients' inflammatory profiles and disease stages. Such insights may pave the way for innovative therapeutic strategies in HF management.