Preserved Skeletal Muscle Mitochondrial Function, Redox State, Inflammation and Mass in Obese Mice with Chronic Heart Failure

The recent development, application, and future prospects of muscle atrophy animal models

Muscle atrophy, characterized by the loss of muscle mass and function, is a hallmark of sarcopenia and cachexia, frequently associated with aging, malignant tumors, chronic heart failure, and malnutrition. Moreover, it poses significant challenges to human health, leading to increased frailty, reduced quality of life, and heightened mortality risks. Despite extensive research on sarcopenia and cachexia, consensus in their assessment remains elusive, with inconsistent conclusions regarding their molecular mechanisms. Muscle atrophy models are crucial tools for advancing research in this field. Currently, animal models of muscle atrophy used for clinical and basic scientific studies are induced through various methods, including aging, genetic editing, nutritional modification, exercise, chronic wasting diseases, and drug administration. Muscle atrophy models also include in vitro and small organism models. Despite their value, each of these models has certain limitations. This review focuses on the limitations and diverse applications of muscle atrophy models to understand sarcopenia and cachexia, and encourage their rational use in future research, therefore deepening the understanding of underlying pathophysiological mechanisms, and ultimately advancing the exploration of therapeutic strategies for sarcopenia and cachexia.

Exercise and nutrition benefit skeletal muscle: From influence factor and intervention strategy to molecular mechanism

Sarcopenia is a progressive systemic skeletal muscle disease induced by various physiological and pathological factors, including aging, malnutrition, denervation, and cardiovascular diseases, manifesting as the decline of skeletal muscle mass and function. Both exercise and nutrition produce beneficial effects on skeletal muscle growth and are viewed as feasible strategies to prevent sarcopenia. Mechanisms involve regulating blood flow, oxidative stress, inflammation, apoptosis, protein synthesis and degradation, and satellite cell activation through exerkines and gut microbiomes. In this review, we summarized and discussed the latest progress and future development of the above mechanisms for providing a theoretical basis and ideas for the prevention and treatment of sarcopenia.

IGF-1 levels in the general population, heart failure patients, and individuals with acromegaly: differences and projections from meta-analyses-a dual perspective

Background

The complex relationship between insulin-like growth factor 1 (IGF-1) levels and heart failure (HF) is not fully understood, particularly across different populations and conditions. This meta-analysis aims to elucidate the dual perspectives of IGF-1 levels in the general population, HF patients, and individuals with treatment-naïve acromegaly, highlighting IGF-1 as a biomarker and potential therapeutic target in HF management.

Methods

Studies were searched across multiple electronic databases up to January 2024 and independently identified by reviewers. The outcomes were analyzed using RevMan 5.4 and STATA 15.

Results

A total of 25 articles were ultimately included in the analysis. Six studies compared IGF-1 levels between HF patients and non-HF controls, revealing significantly lower IGF-1 levels in HF patients (mean difference -20.93; 95% CI -37.88 to -3.97; p = 0.02). This reduction was consistent across various HF subtypes and severities. In addition, individuals with intermediate IGF-1 levels had a lower risk of developing HF [risk ratio (RR) 0.78; 95% CI 0.74-0.83; p < 0.01] and HF-related mortality (RR 0.98; 95% CI 0.97, 0.99; p < 0.01) compared to those with low IGF-1 levels, suggesting a protective role for maintaining adequate IGF-1 levels. Conversely, treatment-naïve acromegaly patients, characterized by excessively high IGF-1 levels, showed a significantly higher incidence of both diastolic HF [odds ratio (OR) 9.08; 95% CI 6.20-13.29; p < 0.01] and systolic HF (OR 13.1; 95% CI 6.64-25.84; p < 0.01), implicating supraphysiological IGF-1 levels in adverse cardiac outcomes.

Conclusions

Our meta-analysis highlights the complex interplay between IGF-1 levels and HF. We found that reduced IGF-1 levels are commonly observed in HF patients and are associated with an increased risk of HF and higher HF-related mortality. Conversely, excessively high levels, as observed in acromegaly, are linked to a higher incidence of HF. Based on these results, it is recommended that cardiac function be closely monitored in patients with reduced IGF-1 levels and in those with acromegaly. These findings suggest that IGF-1 could hold potential prognostic value for risk stratification in HF.

Mitochondrial disorders as a mechanism for the development of obese Sarcopenia

Obese sarcopenia is a severe and prevalent disease in an aging society. Compared to sarcopenia alone, the development and advanced stage of obesity sarcopenia is faster and more severe. Diagnosis of the cause of adipocyte accumulation is also more complicated; however, no effective pharmacological treatment is available. Chronic inflammation is one of the causes of sarcopenia, and obese patients, who are more likely to develop chronic inflammation, may simultaneously suffer from obesity and sarcopenia. Mitochondrial metabolic disorders have been more easily observed in the tissue cells of patients with obesity and sarcopenia. Mitochondrial metabolic disorders include abnormal mtDNA release, mitochondrial autophagy, and dynamic mitochondrial disorders. Therefore, this review will reveal the mechanism of development of obesity myasthenia gravis from the perspective of mitochondria and discuss the currently existing small-molecule drugs.

n-3 PUFA-Enriched Diet Preserves Skeletal Muscle Mitochondrial Function and Redox State and Prevents Muscle Mass Loss in Mice with Chronic Heart Failure

Rationale and Methods: Skeletal muscle derangements, potentially including mitochondrial dysfunction with altered mitochondrial dynamics and high reactive oxygen species (ROS) generation, may lead to protein catabolism and muscle wasting, resulting in low exercise capacity and reduced survival in chronic heart failure (CHF). We hypothesized that 8-week n-3-PUFA isocaloric partial dietary replacement (Fat = 5.5% total cal; EPA + DHA = 27% total fat) normalizes gastrocnemius muscle (GM) mitochondrial dynamics regulators, mitochondrial and tissue pro-oxidative changes, and catabolic derangements, resulting in preserved GM mass in rodent CHF [Myocardial infarction (MI)-induced CHF by coronary artery ligation, left-ventricular ejection fraction <50%]. Results: Compared to control animals (Sham), CHF had a higher GM mitochondrial fission-fusion protein ratio, with low ATP and high ROS production, pro-inflammatory changes, and low insulin signalling. n-3-PUFA normalized all mitochondrial derangements and the pro-oxidative state (oxidized to total glutathione ratio), associated with normalized GM cytokine profile, and enhanced muscle-anabolic insulin signalling and prevention of CHF-induced GM weight loss (all p < 0.05 vs. CHF and p = NS vs. S). Conclusions:n-3-PUFA isocaloric partial dietary replacement for 8 weeks normalizes CHF-induced derangements of muscle mitochondrial dynamics regulators, ROS production and function. n-3-PUFA mitochondrial effects result in preserved skeletal muscle mass, with potential to improve major patient outcomes in clinical settings.

Database mining and animal experiment-based validation of the efficacy and mechanism of Radix Astragali (Huangqi) and Rhizoma Atractylodis Macrocephalae (Baizhu) as core drugs of Traditional Chinese medicine in cancer-related fatigue

ETHNOPHARMACOLOGICAL RELEVANCE

In China, Traditional Chinese medicine (TCM) is often used as the main therapy for cancer-related fatigue (CRF). However, there is limited evidence to prove its therapeutic effect and mechanism.

AIM OF THE STUDY

We aimed to provide a basis for the therapeutic effect of TCM for CRF.

MATERIALS AND METHODS

We performed a meta-analysis to investigate the efficacy of TCM treatment for CRF. Through frequency statistics and association rule mining, we screened the core Chinese medicine components, Astragalus mongholicus Bunge., root (Radix astragali, Huangqi) and Atractylodes macrocephala Koidz., rhizome (Rhizoma atractylodis macrocephalae, Baizhu). We then used animal experiments to verify the effectiveness of these two TCMs and changes in related indicators in mice. Relevant molecular mechanisms were explored through network pharmacological analysis.

RESULTS

Twenty-four randomised control trials (RCTs) involving 1865 patients were included in the meta-analysis. TCM produced more positive effects on CRF than standard therapy alone. Radix astragali and Rhizoma atractylodis macrocephalae, as the core drug pair for the treatment of CRF, enhanced the physical fitness of mice; reduced abdominal circumference, level of inflammatory factors, and tumour weight; and increased body weight and blood sugar. Network pharmacology analysis showed that the mechanism of action of Radix astragali and Rhizoma atractylodis macrocephalae on CRF mainly involved compounds, such as quercetin, kaempferol and luteolin, acting through multiple targets, such as Protein kinase B α (AKT1), Tumour necrosis factor (TNF), and Interleukin-6 (IL-6). These molecules regulate cytokines, cancer signalling, and metabolic pathways and confer an anti-CRF effect.

CONCLUSIONS

TCM may be a promising therapy to relieve CRF in cancer patients. Our research may provide a reference for the clinical application of TCM for treating CRF.

PUFA Supplementation and Heart Failure: Effects on Fibrosis and Cardiac Remodeling

Heart failure (HF) characterized by cardiac remodeling is a condition in which inflammation and fibrosis play a key role. Dietary supplementation with n-3 polyunsaturated fatty acids (PUFAs) seems to produce good results. In fact, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have anti-inflammatory and antioxidant properties and different cardioprotective mechanisms. In particular, following their interaction with the nuclear factor erythropoietin 2 related factor 2 (NRF2), the free fatty acid receptor 4 (Ffar4) receptor, or the G-protein coupled receptor 120 (GPR120) fibroblast receptors, they inhibit cardiac fibrosis and protect the heart from HF onset. Furthermore, n-3 PUFAs increase the left ventricular ejection fraction (LVEF), reduce global longitudinal deformation, E/e ratio (early ventricular filling and early mitral annulus velocity), soluble interleukin-1 receptor-like 1 (sST2) and high-sensitive C Reactive protein (hsCRP) levels, and increase flow-mediated dilation. Moreover, lower levels of brain natriuretic peptide (BNP) and serum norepinephrine (sNE) are reported and have a positive effect on cardiac hemodynamics. In addition, they reduce cardiac remodeling and inflammation by protecting patients from HF onset after myocardial infarction (MI). The positive effects of PUFA supplementation are associated with treatment duration and a daily dosage of 1–2 g. Therefore, both the European Society of Cardiology (ESC) and the American College of Cardiology/American Heart Association (ACC/AHA) define dietary supplementation with n-3 PUFAs as an effective therapy for reducing the risk of hospitalization and death in HF patients. In this review, we seek to highlight the most recent studies related to the effect of PUFA supplementation in HF. For that purpose, a PubMed literature survey was conducted with a focus on various in vitro and in vivo studies and clinical trials from 2015 to 2021.

Network Pharmacology/Metabolomics-Based Validation of AMPK and PI3K/AKT Signaling Pathway as a Central Role of Shengqi Fuzheng Injection Regulation of Mitochondrial Dysfunction in Cancer-Related Fatigue

Chinese herbal medicines have multiple targets and properties, and their use in multidisciplinary cancer therapies has consequently received increasing attention. Here, we have investigated the possible active ingredients associated with cancer-related fatigue (CRF) in the Shengqi Fuzheng Injection (SFI). In vitro cell models were used to measure the regulation effects of SFI on CRF. Metabolomic analysis was used to identify the potential genes and pathways in C2C12 mouse myoblasts treated with SFI, and the interaction of compounds and CRF targets was predicted using network pharmacology and molecular docking analyses. The putative pathways were further verified using immuno-blotting assays. The results showed that SFI significantly inhibited muscle cell apoptosis and increased the mitochondrial membrane potential of muscle cells. The network pharmacology analysis results identified 36 candidate compounds, and 244 potential targets were yielded by SFI, and they shared 10 key targets associated with cancer-related fatigue. According to the enrichment analysis and experimental validation, SFI might ameliorate muscle cell mitochondrial function by activating AMPK and inhibiting the PI3K/Akt signaling pathways, and the expression changes of mitochondrial metabolic enzymes MnSOD and apoptosis-associated proteins Bax and Bcl-2 were also triggered. The functions and mechanisms of SFI in anticancer-related fatigue were found here to be at least partly due to the targeting of the AMPK and PI3K/Akt signaling pathways, and this has highlighted new potential applications for network pharmacology when researching Chinese Medicines.