Role of interleukin-6 in inhibiting hepatic autophagy markers in exercised mice

Acute exercise modulates Trim63 and Bmal1 in the skeletal muscle of IL-10 knockout mice

The anti-inflammatory role of physical exercise is mediated by interleukin 10 (IL-10), and their release is possibly upregulated in response to IL-6. Previous studies demonstrated that mice lacking IL-6 (IL-6 KO mice) exhibited diminished exercise tolerance, and reduced strength. Rev-erbα, a transcriptional suppressor involved in circadian rhythm, has been discovered to inhibit the expression of genes linked to bodily functions, encompassing inflammation and metabolism. It also plays a significant role in skeletal muscle and exercise performance capacity. Given the potential association between Rev-erbα and the immune system and the fact that both pathways are modulated following acute aerobic exercise, we examined the physical performance of IL-10 KO mice and analyzed the modulation of the atrophy and Rev-erbα pathways in the muscle of wild type (WT) and IL-10 KO mice following one session of acute exercise. For each phenotype, WT and IL-10 KO were divided into two subgroups (Control and Exercise). The acute exercise session started at 6 m/min, followed by 3 m/min increments every 3 min until animal exhaustion. Two hours after the end of the exercise protocol, the gastrocnemius muscle was removed and prepared for the reverse transcription-quantitative polymerase chain reaction (RT-q-PCR) and immunoblotting technique. In summary, compared to WT, the IL-10 KO animals showed lower body weight and grip strength in the baseline. The IL-10 control group presented a lower protein content of BMAL1. After the exercise protocol, the IL-10 KO group had higher mRNA levels of Trim63 (atrophy signaling pathway) and lower mRNA levels of Clock and Bmal1 (Rev-erbα signaling pathway). This is the first study showing the relationship between Rev-erbα and atrophy in IL-10 KO mice. Also, we accessed a public database that analyzed the gastrocnemius of MuRF KO mice submitted to two processes of muscle atrophy, a denervation surgery and dexamethasone (Dexa) injections. Independently of knockout, the denervation demonstrated lower Nr1d1 levels. In conclusion, IL-10 seems to be a determinant in the Rev-erbα pathway and atrophy after acute exercise, with no modulation in the baseline state.

Ailanthone induces autophagy and ferroptosis in non‑small cell lung cancer Lewis cells

Ailanthone (AIL), a monomer derived from ailanthus in Chinese medicine, has been demonstrated to have antitumor effects, albeit the underlying mechanism is unknown. Autophagy and ferroptosis are two modes of cell death that have been championed as potential mechanisms implicated in the antitumor effects of various drugs. The present study demonstrated that AIL effectively suppresses the Lewis cell proliferation in non-small cell lung cancer using MTT and colony formation assays. Autophagy and ferroptosis were verified using western blotting, immunofluorescence and ferroptosis detection. Additionally, the findings revealed that regulating the AMPK/mTOR/p70S6k signaling pathway may be the underlying mechanism for the antitumor effect of AIL. The present study established a theoretical foundation for further research into the utilization of AIL as a novel antitumor approach.

Exercise-activated hepatic autophagy via the FN1-α5β1 integrin pathway drives metabolic benefits of exercise

How exercise elicits systemic metabolic benefits in both muscles and non-contractile tissues is unclear. Autophagy is a stress-induced lysosomal degradation pathway that mediates protein and organelle turnover and metabolic adaptation. Exercise activates autophagy in not only contracting muscles but also non-contractile tissues including the liver. However, the role and mechanism of exercise-activated autophagy in non-contractile tissues remain mysterious. Here, we show that hepatic autophagy activation is essential for exercise-induced metabolic benefits. Plasma or serum from exercised mice is sufficient to activate autophagy in cells. By proteomic studies, we identify fibronectin (FN1), which was previously considered as an extracellular matrix protein, as an exercise-induced, muscle-secreted, autophagy-inducing circulating factor. Muscle-secreted FN1 mediates exercise-induced hepatic autophagy and systemic insulin sensitization via the hepatic receptor α5β1 integrin and the downstream IKKα/β-JNK1-BECN1 pathway. Thus, we demonstrate that hepatic autophagy activation drives exercise-induced metabolic benefits against diabetes via muscle-secreted soluble FN1 and hepatic α5β1 integrin signaling.

Effects of Resveratrol on Muscle Inflammation, Energy Utilisation, and Exercise Performance in an Eccentric Contraction Exercise Mouse Model

Eccentric contraction can easily cause muscle damage and an inflammatory response, which reduces the efficiency of muscle contraction. Resveratrol causes anti-inflammatory effects in muscles, accelerates muscle repair, and promotes exercise performance after contusion recovery. However, whether resveratrol provides the same benefits for sports injuries caused by eccentric contraction is unknown. Thus, we explored the effects of resveratrol on inflammation and energy metabolism. In this study, mice were divided into four groups: a control group, an exercise group (EX), an exercise with low-dose resveratrol group (EX + RES25), and an exercise with high-dose resveratrol group (EX + RES150). The results of an exhaustion test showed that the time before exhaustion of the EX + RES150 group was greater than that of the EX group. Tumour necrosis factor-α (Tnfα) mRNA expression was lower in the EX + RES150 group than in the EX group. The energy utilisation of the EX + RES150 group was greater than that of the EX + RES25 group in different muscles. High-dose resveratrol intervention decreased Tnfα mRNA expression and enhanced the mRNA expressions of sirtuin 1, glucose transporter 4, AMP-activated protein kinase α1, and AMP-activated protein kinase α2 in muscles. These results revealed that high-dose resveratrol supplementation can reduce inflammation and oxidation and improve energy utilisation during short-duration high-intensity exercise.

Physical Exercise and Liver Autophagy: Potential Roles of IL-6 and Irisin

Autophagic dysregulation contributes to liver diseases. Although some investigations have examined the effects of endurance and resistance exercise on autophagy activation, potential myokines responsible for skeletal muscle-liver crosstalk are still unknown. Based on experimental studies and bioinformatics, we hypothesized that interleukin 6 (IL-6) and irisin might be key players in the contraction-induced release of molecules that regulate liver autophagic responses.

Impact of Different Physical Exercises on the Expression of Autophagy Markers in Mice

Although physical exercise-induced autophagy activation has been considered a therapeutic target to enhance tissue health and extend lifespan, the effects of different exercise models on autophagy in specific metabolic tissues are not completely understood. This descriptive investigation compared the acute effects of endurance (END), exhaustive (ET), strength (ST), and concurrent (CC) physical exercise protocols on markers of autophagy, genes, and proteins in the gastrocnemius muscle, heart, and liver of mice. The animals were euthanized immediately (0 h) and six hours (6 h) after the acute exercise for the measurement of glycogen levels, mRNA expression of Prkaa1, Ppargc1a, Mtor, Ulk1, Becn1, Atg5, Map1lc3b, Sqstm1, and protein levels of Beclin 1 and ATG5. The markers of autophagy were measured by quantifying the protein levels of LC3II and Sqstm1/p62 in response to three consecutive days of intraperitoneal injections of colchicine. In summary, for gastrocnemius muscle samples, the main alterations in mRNA expressions were observed after 6 h and for the ST group, and the markers of autophagy for the CC group were increased (i.e., LC3II and Sqstm1/p62). In the heart, the Beclin 1 and ATG5 levels were downregulated for the ET group. Regarding the markers of autophagy, the Sqstm1/p62 in the heart tissue was upregulated for the END and ST groups, highlighting the beneficial effects of these exercise models. The liver protein levels of ATG5 were downregulated for the ET group. After the colchicine treatment, the liver protein levels of Sqstm1/p62 were decreased for the END and ET groups compared to the CT, ST, and CC groups. These results could be related to diabetes and obesity development or liver dysfunction improvement, demanding further investigations.

Autophagy Modulation in Lymphocytes From COVID-19 Patients: New Therapeutic Target in SARS-COV-2 Infection

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the novel coronavirus, causing coronavirus disease 2019 (COVID-19). During virus infection, several pro-inflammatory cytokines are produced, leading to the "cytokine storm." Among these, interleukin (IL)-6, tumor necrosis factor-α (TNF-α), and IL-1β seem to have a central role in the progression and exacerbation of the disease, leading to the recruitment of immune cells to infection sites. Autophagy is an evolutionarily conserved lysosomal degradation pathway involved in different aspects of lymphocytes functionality. The involvement of IL-6, TNF-α, and IL-1β in autophagy modulation has recently been demonstrated. Moreover, preliminary studies showed that SARS-CoV-2 could infect lymphocytes, playing a role in the modulation of autophagy. Several anti-rheumatic drugs, now proposed for the treatment of COVID-19, could modulate autophagy in lymphocytes, highlighting the therapeutic potential of targeting autophagy in SARS-CoV-2 infection.

Physiopathology of Lifestyle Interventions in Non-Alcoholic Fatty Liver Disease (NAFLD)

Non-alcoholic fatty liver disease (NAFLD) is a major health problem, and its prevalence has increased in recent years. Diet and exercise interventions are the first-line treatment options, with weight loss via a hypocaloric diet being the most important therapeutic target in NAFLD. However, most NAFLD patients are not able to achieve such weight loss. Therefore, the requisite is the investigation of other effective therapeutic approaches. This review summarizes research on understanding complex pathophysiology underlying dietary approaches and exercise interventions with the potential to prevent and treat NAFLD.

Irisin and Autophagy: First Update

Aging and sedentary life style are considered independent risk factors for many disorders. Under these conditions, accumulation of dysfunctional and damaged cellular proteins and organelles occurs, resulting in a cellular degeneration and cell death. Autophagy is a conserved recycling pathway responsible for the degradation, then turnover of cellular proteins and organelles. This process is a part of the molecular underpinnings by which exercise promotes healthy aging and mitigate age-related pathologies. Irisin is a myokine released during physical activity and acts as a link between muscles and other tissues and organs. Its main beneficial function is the change of subcutaneous and visceral adipose tissue into brown adipose tissue, with a consequential increase in thermogenesis. Irisin modulates metabolic processes, acting on glucose homeostasis, reduces systemic inflammation, maintains the balance between resorption and bone formation, and regulates the functioning of the nervous system. Recently, some of its pleiotropic and favorable properties have been attributed to autophagy induction, posing irisin as an important regulator of autophagy by exercise. This review article proposes to bring together for the first time the "state of the art" knowledge regarding the effects of irisin and autophagy. Furthermore, treatments on relation between exercise/myokines and autophagy have been also achieved.

Milk‑derived hexapeptide PGPIPN prevents and attenuates acute alcoholic liver injury in mice by reducing endoplasmic reticulum stress

Bioactive peptides are an emerging area of biomedical research in the study of numerous human diseases, including acute alcoholic liver injury (AALI). To study the role and mechanism of the milk-derived hexapeptide Pro-Gly-Pro-Ile-Pro-Asn (PGPIPN) in preventing and reducing AALI, the present study established a mouse model of AALI. PGPIPN was used as a therapeutic drug, and glutathione (GSH) was used as a positive control. The body and liver weights of mice were measured, and the liver indexes were calculated to observe mice health. The pathological morphology of liver tissues stained with hematoxylin and eosin were examined to analyze hepatic injury, and hepatocyte apoptosis was measured with a TUNEL assay. The concentrations or activities of alanine aminotransferase (ALT), aspartate aminotransferase, tumor necrosis factor-α, interleukin (IL)-1β, IL-6, triglyceride, total cholesterol, malondialdehyde, superoxide dismutase and GSH peroxidase (GSH-PX) were detected in serum and/or liver homogenates. The 78 kDa glucose-regulated protein (GRP78), protein kinase R-like (PKR) endoplasmic reticulum kinase (PERK), phosphorylated (p)-PERK, eukaryotic initiation factor 2α (eIF-2α), p-eIF-2α, inositol-requiring enzyme 1α (IRE-1α), spliced X-box binding protein 1 (XBP-1s), C/EBP homologous protein (CHOP), caspase-3 and cleaved caspase-3 proteins associated with endoplasmic reticulum stress in hepatocytes were assessed by western blotting, and RNA levels of XBP-1s, CHOP and caspase-3 genes were assessed by reverse transcription-quantitative PCR. The results suggested that PGPIPN attenuated alcoholic hepatocyte damage in animal models and reduced hepatocyte oxidative stress in a dose-dependent manner. Moreover, PGPIPN reduced endoplasmic reticulum stress by regulating the expression levels of p-PERK, p-eIF-2α, XBP-1s, CHOP, caspase-3 and cleaved caspase-3. Collectively, the present results indicated that PGPIPN, as a potential therapeutic drug for AALI, exerted a protective effect on the liver and could reduce liver damage.