Nutrition and microRNAs: Novel Insights to Fight Sarcopenia

Association between oxidative balance score and skeletal muscle mass and strength: NHANES from 2011 to 2018

Objective

Oxidative stress is a risk factor for sarcopenia. The Oxidative Balance Score (OBS) is a widely employed tool for evaluating the oxidative stress-related exposures from dietary and lifestyle factors. In this study, we aimed to conducted to explore the relationship between OBS and skeletal muscle mass and strength.

Methods

6,438 subjects from 2011 to 2018 and 5,414 from 2011 to 2014 from the National Health and Nutrition Examination Survey (NHANES) were selected for analysis. The correlations between OBS and skeletal muscle mass and handgrip strength were investigated using multivariate logistic regression and linear regression analysis.

Results

Compared with lowest OBS, participants with OBS in the highest quartile had lower risk of low skeletal muscle mass (OR = 0.173 (0.120 ~ 0.248), p < 0.0001) and low handgrip strength (β = 0.173 (0.120 ~ 0.248), p = 0.011). The negative association also were found between dietary/lifestyle OBS and skeletal muscle mass (OR = 0.268 (0.178 ~ 0.404), p < 0.0001; OR = 0.231 (0.130 ~ 0.410), p < 0.0001) and handgrip strength (β = 1.812 (0.555 ~ 3.071), p = 0.008; β = -2.255 (-3.430 ~ -1.079), p < 0.001) independently. The positive association remains significant, especially among men and those with higher education levels by subgroup analysis.

Conclusion

All of these results indicated a negative association between OBS and low skeletal muscle mass and handgrip strength. An antioxidant-rich diet and healthy lifestyle are crucial for enhancing skeletal muscle mass and strength.

Zebrafish as an Emerging Model for Sarcopenia: Considerations, Current Insights, and Future Directions

Sarcopenia poses a significant challenge to public health and can severely impact the quality of life of aging populations. Despite extensive efforts to study muscle degeneration using traditional animal models, there is still a lack of effective diagnostic tools, precise biomarkers, and treatments for sarcopenia. Zebrafish models have emerged as powerful tools in biomedical research, providing unique insights into age-related muscle disorders like sarcopenia. The advantages of using zebrafish models include their rapid growth outside of the embryo, optical transparency during early developmental stages, high reproductive potential, ease of husbandry, compact size, and genetic tractability. By deepening our understanding of the molecular processes underlying sarcopenia, we may develop novel diagnostic tools and effective treatments that can improve the lives of aging individuals affected by this condition. This review aims to explore the unique advantages of zebrafish as a model for sarcopenia research, highlight recent breakthroughs, outline potential avenues for future investigations, and emphasize the distinctive contributions that zebrafish models offer. Our research endeavors to contribute significantly to address the urgent need for practical solutions to reduce the impact of sarcopenia on aging populations, ultimately striving to enhance the quality of life for individuals affected by this condition.

The syndromic triad of COVID-19, type 2 diabetes, and malnutrition

The coronavirus disease 2019 (COVID-19) pandemic challenges our collective understanding of transmission, prevention, complications, and clinical management of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Risk factors for severe infection, morbidity, and mortality are associated with age, environment, socioeconomic status, comorbidities, and interventional timing. Clinical investigations report an intriguing association of COVID-19 with diabetes mellitus and malnutrition but incompletely describe the triphasic relationship, its mechanistic pathways, and potential therapeutic approaches to address each malady and their underlying metabolic disorders. This narrative review highlights common chronic disease states that interact epidemiologically and mechanistically with the COVID-19 to create a syndromic phenotype-the COVID-Related Cardiometabolic Syndrome-linking cardiometabolic-based chronic disease drivers with pre-, acute, and chronic/post-COVID-19 disease stages. Since the association of nutritional disorders with COVID-19 and cardiometabolic risk factors is well established, a syndromic triad of COVID-19, type 2 diabetes, and malnutrition is hypothesized that can direct, inform, and optimize care. In this review, each of the three edges of this network is uniquely summarized, nutritional therapies discussed, and a structure for early preventive care proposed. Concerted efforts to identify malnutrition in patients with COVID-19 and elevated metabolic risks are needed and can be followed by improved dietary management while simultaneously addressing dysglycemia-based chronic disease and malnutrition-based chronic disease.

Skeletal muscle oxidative stress and inflammation in aging: Focus on antioxidant and anti-inflammatory therapy

With aging, the progressive loss of skeletal muscle will have negative effect on multiple physiological parameters, such as exercise, respiration, thermoregulation, and metabolic homeostasis. Accumulating evidence reveals that oxidative stress and inflammation are the main pathological characteristics of skeletal muscle during aging. Here, we focus on aging-related sarcopenia, summarize the relationship between aging and sarcopenia, and elaborate on aging-mediated oxidative stress and oxidative damage in skeletal muscle and its critical role in the occurrence and development of sarcopenia. In addition, we discuss the production of excessive reactive oxygen species in aging skeletal muscle, which reduces the ability of skeletal muscle satellite cells to participate in muscle regeneration, and analyze the potential molecular mechanism of ROS-mediated mitochondrial dysfunction in aging skeletal muscle. Furthermore, we have also paid extensive attention to the possibility and potential regulatory pathways of skeletal muscle aging and oxidative stress mediate inflammation. Finally, in response to the abnormal activity of oxidative stress and inflammation during aging, we summarize several potential antioxidant and anti-inflammatory strategies for the treatment of sarcopenia, which may provide beneficial help for improving sarcopenia during aging.

Metabolic Pathways and Ion Channels Involved in Skeletal Muscle Atrophy: A Starting Point for Potential Therapeutic Strategies

Skeletal muscle tissue has the important function of supporting and defending the organism. It is the largest apparatus in the human body, and its function is important for contraction and movements. In addition, it is involved in the regulation of protein synthesis and degradation. In fact, inhibition of protein synthesis and/or activation of catabolism determines a pathological condition called muscle atrophy. Muscle atrophy is a reduction in muscle mass resulting in a partial or complete loss of function. It has been established that many physiopathological conditions can cause a reduction in muscle mass. Nevertheless, it is not well known that the molecular mechanisms and signaling processes caused this dramatic event. There are multiple concomitant processes involved in muscle atrophy. In fact, the gene transcription of some factors, oxidative stress mechanisms, and the alteration of ion transport through specific ion channels may contribute to muscle function impairment. In this review, we focused on the molecular mechanisms responsible for muscle damage and potential drugs to be used to alleviate this disabling condition.

The Whole-transcriptome Landscape of Diabetes-related Sarcopenia Reveals the Specific Function of Novel lncRNA Gm20743

While the exact mechanism remains unclear, type 2 diabetes mellitus increases the risk of sarcopenia which is characterized by decreased muscle mass, strength, and function. Whole-transcriptome RNA sequencing and informatics were performed on the diabetes-induced sarcopenia model of db/db mice. To determine the specific function of lncRNA Gm20743, the detection of Mito-Sox, reactive oxygen species, Ethynyl-2′-deoxyuridine, and myosin heavy chain was performed in overexpressed and knockdown-Gm20743 C2C12 cells. RNA-seq data and informatics revealed the key lncRNA-mRNA interactions and indicated a potential regulatory role of lncRNAs. We characterized three core candidate lncRNAs Gm20743, Gm35438, 1700047G03Rik, and their potential function. Furthermore, the results suggested lncRNA Gm20743 may be involved in regulating mitochondrial function, oxidative stress, cell proliferation, and myotube differentiation in skeletal muscle cells. These findings significantly improve our understanding of lncRNAs that may mediate muscle mass, strength, and function in diabetes and represent potential therapeutic targets for diabetes-induced sarcopenia.

The role of lncRNA Gm20743 in the development of diabetic sarcopenia is explored using a mouse model.

MiR-320-3p Regulates the Proliferation and Differentiation of Myogenic Progenitor Cells by Modulating Actin Remodeling

Skeletal myogenesis is essential for the maintenance of muscle quality and quantity, and impaired myogenesis is intimately associated with muscle wasting diseases. Although microRNA (miRNA) plays a crucial role in myogenesis and relates to muscle wasting in obesity, the molecular targets and roles of miRNAs modulated by saturated fatty acids (SFA) are largely unknown. In the present study, we investigated the role of miR-320-3p on the differentiation of myogenic progenitor cells. Palmitic acid (PA), the most abundant dietary SFA, suppressed myogenic factors expression and impaired differentiation in C2C12 myoblasts, and these effects were accompanied by CFL2 downregulation and miR-320-3p upregulation. In particular, miR-320-3p appeared to target CFL2 mRNA directly and suppress the expression of CFL2, an essential factor for filamentous actin (F-actin) depolymerization. Transfection of myoblasts with miR-320-3p mimic increased F-actin formation and nuclear translocation of Yes-associated protein 1 (YAP1), a key component of mechanotransduction. Furthermore, miR-320-3p mimic increased myoblast proliferation and markedly impeded the expression of MyoD and MyoG, consequently inhibiting myoblast differentiation. In conclusion, our current study highlights the role of miR-320-3p on CFL2 expression, YAP1 activation, and myoblast differentiation and suggests that PA-inducible miR-320-3p is a significant mediator of muscle wasting in obesity.

A review on the Role of Oral Nutritional Supplements in Chronic Obstructive Pulmonary Disease

Due to the high smoking rate in developing countries and the rising aging population in high-income countries, the global prevalence of chronic obstructive pulmonary disease (COPD), estimated to be 11.7%, is increasing and is the third-leading cause of mortality. COPD is likely to be present in elderly individuals with impaired gastro-enteric functions. Gastrointestinal congestion, dyspnea, and anxiety are pathophysiological characteristics of COPD, contributing to poor appetite, reduced dietary intake, and high-energy expenditure. These factors are implicated in the progression of malnutrition in COPD patients. Malnutrition is detrimental to lung functions and is associated with an increased risk of infection, exacerbation and mortality, and a longer duration of hospitalization. Therefore, nutritional support to treat malnutrition in COPD patients is very vital. Oral nutritional supplements (ONS) may hold the key to COPD treatment. To clarify this statement, we review current evidence for ONS in COPD patients to benefit from clinical outcomes.

Sarcopenia: Etiology, Nutritional Approaches, and miRNAs

Sarcopenia, an age-related decline in skeletal muscle mass and function, dramatically affects the quality of life. Although there is a consensus that sarcopenia is a multifactorial syndrome, the etiology and underlying mechanisms are not yet delineated. Moreover, research about nutritional interventions to prevent the development of sarcopenia is mainly focused on the amount and quality of protein intake. The impact of several nutrition strategies that consider timing of food intake, anti-inflammatory nutrients, metabolic control, and the role of mitochondrial function on the progression of sarcopenia is not fully understood. This narrative review summarizes the metabolic background of this phenomenon and proposes an integral nutritional approach (including dietary supplements such as creatine monohydrate) to target potential molecular pathways that may affect reduce or ameliorate the adverse effects of sarcopenia. Lastly, miRNAs, in particular those produced by skeletal muscle (MyomiR), might represent a valid tool to evaluate sarcopenia progression as a potential rapid and early biomarker for diagnosis and characterization.

A Potential miRNA-mRNA Network for Dementia and Hernia Crosstalk

Background

It has been reported that there may be a potential link between hernia and dementia. However, the exact mechanisms of their association have not been established. This study is aimed at constructing miRNA-mRNA networks to elucidate on the potential link between dementia and hernia.

Methods

Gene expression profiles for dementia, herniation, and skeletal muscle were downloaded from the GEO database after which differentially expressed mRNAs and miRNAs were obtained. In addition, fascia tissue samples were obtained during surgery. A total of 41 patients were recruited in this study, and expression levels of candidate genes were examined using quantitative RT-PCR. Luciferase reporter gene assays were used to identify potential miRNA-mRNA regulatory pathways.

Results

Differentially expressed mRNAs and miRNAs were screened. A potential miRNA-mRNA network revealing the crosstalk mechanism between herniation and dementia was identified. Single cell analysis revealed that PI16 was highly enriched in adipose tissues, skeletal muscles, and in the skin. GSEA enrichment analysis showed that PI16 is involved in adipose metabolism, muscle functions, and energy metabolism. In clinical samples, PI16 was found to be upregulated in hernia, while miR-4451 was found to be downregulated. The luciferase reporter gene assay revealed that downregulation of circulating miR-4451 may be responsible for the upregulated PI16 expression in hernia sacs.

Conclusions

We constructed an miRNA-mRNA network that shows the potential association between dementia and hernia. We also found that miR-4451 regulates the PI16 expression, which may be a key target and biomarker for hernia pathogenesis and dementia crosstalk.

Age-Related Alterations at Neuromuscular Junction: Role of Oxidative Stress and Epigenetic Modifications

With advancing aging, a decline in physical abilities occurs, leading to reduced mobility and loss of independence. Although many factors contribute to the physio-pathological effects of aging, an important event seems to be related to the compromised integrity of the neuromuscular system, which connects the brain and skeletal muscles via motoneurons and the neuromuscular junctions (NMJs). NMJs undergo severe functional, morphological, and molecular alterations during aging and ultimately degenerate. The effect of this decline is an inexorable decrease in skeletal muscle mass and strength, a condition generally known as sarcopenia. Moreover, several studies have highlighted how the age-related alteration of reactive oxygen species (ROS) homeostasis can contribute to changes in the neuromuscular junction morphology and stability, leading to the reduction in fiber number and innervation. Increasing evidence supports the involvement of epigenetic modifications in age-dependent alterations of the NMJ. In particular, DNA methylation, histone modifications, and miRNA-dependent gene expression represent the major epigenetic mechanisms that play a crucial role in NMJ remodeling. It is established that environmental and lifestyle factors, such as physical exercise and nutrition that are susceptible to change during aging, can modulate epigenetic phenomena and attenuate the age-related NMJs changes. This review aims to highlight the recent epigenetic findings related to the NMJ dysregulation during aging and the role of physical activity and nutrition as possible interventions to attenuate or delay the age-related decline in the neuromuscular system.

To Synthesize Hydroxyapatite by Modified Low Temperature Method Loaded with Bletilla striata Polysaccharide as Antioxidant for the Prevention of Sarcopenia by Intramuscular Administration

Oxidative stress has been suggested as an important factor in the progress of sarcopenia. The current treatments for sarcopenia have the disadvantages of insufficient effect or daily administration. Therefore, an alternative for effective, safety and long-term treatment may be a solution for unmet needs. Bletilla striata polysaccharide has been reported to have anti-oxidative and anti-inflammatory properties. In this study, we used Bletilla striata polysaccharide (BSP) combined with hydroxyapatite, a carrier. We hypothesized that the resulting combination (BSP-HAP) is a good formula for the controlled release of BSP via intramuscular (IM) administration, so as to prevent the worsening of presarcopenia or even recover from the early stage of the illness. In this research, BSP-HAP was synthesized by a modified low temperature co-precipitation process that would be beneficial for BSP loading. By conducting DCFDA, WST-1 and the Live/Dead assay, BSP-HAP is shown to be a biocompatible material which may release BSP by cells through the endocytosis pathway. Animal studies revealed that the rats treated with BSP-HAP could effectively recover muscle endurance, grip strength or fat/lean mass ratio from lipopolysaccharide (LPS)-induced sarcopenia. This study shows BSP delivered by BSP-HAP system has potential for application in the treatment and prevention of sarcopenia in the future.

Physical frailty and long-term mortality in older people with chronic heart failure with preserved and reduced ejection fraction: a retrospective longitudinal study

BACKGROUND

Frailty, a syndrome characterized by a decline in function reserve, is common in older patients with heart failure (HF) and is associated with prognosis. This study aimed to evaluate the impact of frailty on outcomes in older patients with preserved and reduced cardiac function.

METHODS

In total, 811 adults aged ≥65 years were consecutively enrolled from 2009 to 2018. HF was diagnosed according to the ICD9 code and a 2D echocardiogram was categorized by reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF). The index date was registered at the time of HF. All patients received a comprehensive geriatric assessment, and clinical outcomes were examined with adjustment of the other prognostic variables.

RESULTS

Mean age was 80.5 ± 7.1 years. The prevalence of HF, HFpEF, HFrEF, Fried, and Rockwood frailty indicators was 28.5, 10.4, 9.7, 52.5, and 74.9%, respectively. At baseline, scores in the Timed Up and Go test was closely associated with the severity of HF, either with HFpEF or HFrEF. After a mean follow-up of 3.2 ± 2.0 years, we found that HF patients with low handgrip strength (HGS) had the poorest survival, followed by non-HF patients with decreased HGS, and HF with fair HGS in comparison with non-HF with fair HGS (p = 0.008) if participants were arbitrarily divided into two HGS groups. In all patients, a high Rockwood frailty index was independently associated with increased mortality (adjusted hazard ratio [aHR] = 1.05; 95% confidence interval [CI]: 1.0004 to 1.10). In addition, the adjusted mortality HR was 3.42 with decreased HGS (95% CI: 1.03 to 11.40), 7.65 with use of mineralocorticoid receptor antagonist (95% CI: 2.22 to 26.32), and 1.26 with associated multi-comorbidities assessed by Charlson comorbidity index (95% CI: 1.05 to 1.51).

CONCLUSIONS

Our study results indicate that frailty and decreased physical functions were associated with HF. Besides, frailty and HGS predicted prognosis in the patients, and there was a combined effect of HF and low HGS on survival.

Taurine Attenuates Catabolic Processes Related to the Onset of Sarcopenia

Sarcopenia that occurs with advancing age is characterized by a gradual loss of muscle protein component due to the activation of catabolic pathways, increased level of inflammation, and mitochondrial dysfunction. Experimental evidence demonstrates that several physio-pathological processes involved in the onset of sarcopenia may be counteracted by the intake of specific amino acids or antioxidant molecules, suggesting that diet may represent an effective strategy for improving the anabolic response of muscle during aging. The non-essential amino acid taurine is highly expressed in several mammalian tissues, including skeletal muscle where it is involved in the ion channel regulation, in the modulation of intracellular calcium concentration, and where it plays an important role as an antioxidant and anti-inflammatory factor. Here, with the purpose to reproduce the chronic low-grade inflammation characteristics of senescent muscle in an in vitro system, we exploited the role of Tumor Necrosis Factor α (TNF) and we analyzed the effect of taurine in the modulation of different signaling pathways known to be dysregulated in sarcopenia. We demonstrated that the administration of high levels of taurine in myogenic L6 cells stimulates the differentiation process by downregulating the expression of molecules involved in inflammatory pathways and modulating processes such as autophagy and apoptosis. Although further studies are currently ongoing in our laboratory to better elucidate the molecular mechanisms responsible for the positive effect of taurine on myogenic differentiation, this study suggests that taurine supplementation may represent a strategy to delay the loss of mass and functionality characteristic of senescent muscles.