Essential roles of the cytokine oncostatin M in crosstalk between muscle fibers and immune cells in skeletal muscle after aerobic exercise

Suppression of renal crystal formation, inflammation, and fibrosis by blocking oncostatin M receptor β signaling

Oncostatin M (OSM) has pleiotropic effects on various inflammatory diseases, including kidney stone disease. The prevalence of kidney stones has increased worldwide, despite recent therapeutic advances, due to its high recurrence rate, suggesting the importance of prevention of repeated recurrence in the treatment of kidney stone disease. Using a mouse model of renal crystal formation, we investigated the preventive effects of blockade of OSM receptor β (OSMRβ) signaling on the development of kidney stone disease by treatment with a monoclonal anti-OSMRβ antibody that we generated. The anti-OSMRβ antibody abrogated OSM-induced phosphorylation of STAT3 and expression of crystal-binding molecules (Opn, Anxa1, Anxa2) and inflammation/fibrosis-associated molecules (Tnfa, Tgfb, Col1a2) in renal tubular epithelial cells and fibroblasts. In glyoxylate-injected mice, a mouse model of renal crystal formation, there was significant suppression of crystal deposits and expression of crystal-binding molecules (Opn, Anxa1, Anxa2), a tubular injury marker (Kim-1), and inflammation/fibrosis-associated molecules (Tnfa, Il1b, Mcp-1, Tgfb, Col1a2) in the kidneys of the anti-OSMRβ antibody-treated mice, compared with those in vehicle- or isotype control antibody-treated mice. In addition, treatment with the anti-OSMRβ antibody significantly decreased infiltrating macrophages and fibrosis in the kidneys. These findings suggest that anti-OSMRβ antibody-treatment may be effective in preventing kidney stone disease.

The Role of Chemokines in Obesity and Exercise-Induced Weight Loss

Obesity is a global health crisis that is closely interrelated to many chronic diseases, such as cardiovascular disease and diabetes. This review provides an in-depth analysis of specific chemokines involved in the development of obesity, including C-C motif chemokine ligand 2 (CCL2), CCL3, CCL5, CCL7, C-X-C motif chemokine ligand 8 (CXCL8), CXCL9, CXCL10, CXCL14, and XCL1 (lymphotactin). These chemokines exacerbate the symptoms of obesity by either promoting the inflammatory response or by influencing metabolic pathways and recruiting immune cells. Additionally, the research highlights the positive effect of exercise on modulating chemokine expression in the obese state. Notably, it explores the potential effects of both aerobic exercises and combined aerobic and resistance training in lowering levels of inflammatory mediators, reducing insulin resistance, and improving metabolic health. These findings suggest new strategies for obesity intervention through the modulation of chemokine levels by exercise, providing fresh perspectives and directions for the treatment of obesity and future research.

Effects of Exercise-Induced Changes in Myokine Expression on the Tumor Microenvironment

In this narrative review, we summarize the direct and indirect effects that myokines have on the tumor microenvironment. We took studies of various cancer types and species into account. Systematic reviews and meta-analyses that matched the search terms were also considered. We searched databases for six months. As a narrative approach was chosen, no data was analyzed or reanalyzed. The goal of this narrative review is to create an overview on the topic to identify research gaps and answer the questions as to whether myokine expression may be relevant in cancer research in regard to the tumor microenvironment. Six commonly known myokines were chosen. We found strong links between the influence exercise has on interleukin-6, oncostatin M, secreted protein acidic and rich in cysteine, and irisin in the context of tumor progression and inhibition via interactions with the tumor microenvironment. It became clear that the effects of myokines on the tumor microenvironment can vary and contribute to disease progression or regression. Interactions among myokines and immune cells must also be considered and require further investigation. To date, no study has shown a clear connection, while multiple studies suggest further investigation of the topic, similar to the effects of exercise on myokine expression.

Mechanisms Underlying the Rarity of Skeletal Muscle Cancers

Skeletal muscle (SKM), despite comprising ~40% of body mass, rarely manifests cancer. This review explores the mechanisms that help to explain this rarity, including unique SKM architecture and function, which prohibits the development of new cancer as well as negates potential metastasis to SKM. SKM also presents a unique immune environment that may magnify the anti-tumorigenic effect. Moreover, the SKM microenvironment manifests characteristics such as decreased extracellular matrix stiffness and altered lactic acid, pH, and oxygen levels that may interfere with tumor development. SKM also secretes anti-tumorigenic myokines and other molecules. Collectively, these mechanisms help account for the rarity of SKM cancer.

Exercise-induced crosstalk between immune cells and adipocytes in humans: Role of oncostatin-M

The discovery of exercise-regulated circulatory factors has fueled interest in organ crosstalk, especially between skeletal muscle and adipose tissue, and the role in mediating beneficial effects of exercise. We studied the adipose tissue transcriptome in men and women with normal glucose tolerance or type 2 diabetes following an acute exercise bout, revealing substantial exercise- and time-dependent changes, with sustained increase in inflammatory genes in type 2 diabetes. We identify oncostatin-M as one of the most upregulated adipose-tissue-secreted factors post-exercise. In cultured human adipocytes, oncostatin-M enhances MAPK signaling and regulates lipolysis. Oncostatin-M expression arises predominantly from adipose tissue immune cell fractions, while the corresponding receptors are expressed in adipocytes. Oncostatin-M expression increases in cultured human Thp1 macrophages following exercise-like stimuli. Our results suggest that immune cells, via secreted factors such as oncostatin-M, mediate a crosstalk between skeletal muscle and adipose tissue during exercise to regulate adipocyte metabolism and adaptation.

Blockade of OSMRβ signaling ameliorates skin lesions in a mouse model of human atopic dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by severe pruritus and eczematous skin lesions. Although IL-31, a type 2 helper T (Th2)-derived cytokine, is important to the development of pruritus and skin lesions in AD, the blockade of IL-31 signaling does not improve the skin lesions in AD. Oncostatin M (OSM), a member of IL-6 family of cytokines, plays important roles in the regulation of various inflammatory responses through OSM receptor β subunit (OSMRβ), a common receptor subunit for OSM and IL-31. However, the effects of OSM on the pathogenesis of AD remain to be elucidated. When AD model mice were treated with OSM, skin lesions were exacerbated and IL-4 production was increased in the lymph nodes. Next, we investigated the effects of the monoclonal antibody (mAb) against OSMRβ on the pathogenesis of AD. Treatment with the anti-OSMRβ mAb (7D2) reduced skin severity score in AD model mice. In addition to skin lesions, scratching behavior was decreased by 7D2 mAb with the reduction in the number of OSMRβ-positive neurons in the dorsal root ganglia of AD model mice. 7D2 mAb also reduced the serum concentration of IL-4, IL-13, and IgE as well as the gene expressions of IL-4 and IL-13 in the lymph nodes of AD model mice. Blockade of both IL-31 and OSM signaling is suggested to suppress both pruritus and Th2 responses, resulting in the improvement of skin lesions in AD. The anti-OSMRβ mAb may be a new therapeutic candidate for the treatment of AD.

Oncostatin M mediates cardioprotection via angiogenesis in ischemic heart disease

Objective

Oncostatin M (OSM) is an inflammatory cytokine belonging to the interleukin-6 family member, which plays an important role in various cardiovascular diseases. We recently reported increased serum OSM levels in patients with coronary artery disease. However, the specific role in HF with ischemic heart disease (IHD) remains unclear.

Methods and results

A total of 120 patients with HF and 48 control subjects were enrolled in this study. Serum OSM levels were measured using a sandwich technique immunoassay during the compensated state. The results revealed significantly higher serum OSM levels in HF patients compared to controls. Importantly, HF patients with IHD had higher OSM levels, and those with collateral flow showed the even higher levels, indicating a potential involvement in angiogenesis. Furthermore, a positive correlation was found between serum OSM levels and levels of vascular endothelial growth factor (VEGF). In vitro experiments demonstrated that recombinant OSM upregulated VEGF production in cultured human coronary artery endothelial cells. We additionally observed that endogenous OSM levels were enhanced through exercise. Lastly, we identified the potential of SGLT2 inhibitors to enhance OSM production.

Conclusions

Serum OSM levels were elevated in HF patients, particularly in those with IHD Our data indicated that endogenous OSM induces VEGF production in the heart, suggesting the activation of angiogenesis, which can be further enhanced by exercise or SGLT2 inhibitors.

Walking 200 min per day keeps the bariatric surgeon away

Exercise and increased physical activity are vital components of the standard treatment guidelines for many chronic diseases such as diabetes, obesity and cardiovascular disease. Although strenuous exercise cannot be recommended to people with numerous chronic conditions, walking is something most people can perform. In comparison to high-intensity training, the metabolic consequences of low-intensity walking have been less well studied. We present here a feasibility study of a subject who performed an exercise intervention of low-intensity, non-fatiguing walking on a deskmill/treadmill for 200 min daily, approximately the average time a German spends watching television per day. This low-impact physical activity has the advantages that it can be done while performing other tasks such as reading or watching TV, and it can be recommended to obese patients or patients with heart disease. We find that this intervention led to substantial weight loss, comparable to that of bariatric surgery. To study the metabolic changes caused by this intervention, we performed an in-depth metabolomic profiling of the blood both directly after walking to assess the acute changes, as well as 1.5 days after physical activity to identify the long-term effects that persist. We find changes in acylcarnitine levels suggesting that walking activates fatty acid beta oxidation, and that this mitochondrial reprogramming is still visible 1.5 days post-walking. We also find that walking mildly increases gut permeability, leading to increased exposure of the blood to metabolites from the gut microbiome. Overall, these data provide a starting point for designing future intervention studies with larger cohorts.