Silver linings on the horizon: highlights from the 10th Cachexia Conference

Amelioration of cancer cachexia with preemptive administration of tumor necrosis factor-α blocker

Cancer cachexia is syndrome accompanying weight reduction, fat loss, muscle atrophy in patients with advanced cancer. Since tumor necrosis factor-α (TNF-α) played pivotal role in cancer cachexia, we hypothesized preemptive administration of TNF-α antibody might mitigate cancer cachexia. Detailed molecular mechanisms targeting muscle atrophy, cachexic inflammation, and catabolic catastrophe were explored whether TNF-α antibody can antagonize these cachexic mechanisms. Stimulated with preliminary finding human antibody, infliximab or adalimumab, significantly inhibited TNF-α as well as their signals relevant to cachexia in mice, preemptive administration of 1.5 mg/kg adalimumab was done in C-26-induced cancer cachexia. Adalimumab significantly mitigated cancer cachexia manifested with significantly lesser weight loss, leg muscle preservation, and higher survival compared to cachexia control (p<0.05). Significant ameliorating action of muscle atrophy were accompanied significant decreases of muscle-specific UPS like atrogin-1/MuRF-1, Pax-7, PCG-1α, and Mfn-2 after adalimumab (p<0.01) and significantly attenuated lipolysis with inhibition of ATGL HSL, and MMPs. Cachexic factors including IL-6 expression, serum IL-6, gp130, IL-6R, JAK2, and STAT3 were significantly inhibited with adalimumab (p<0.01). Genes implicated in cachexic inflammation like NF-κB, c-Jun/c-Fos, and MAPKs were significantly repressed, while mTOR/AKT was significantly increased adalimumab (p<0.05). Conclusively, preemptive administration of adalimumab can be tried in high risk to cancer cachexia.

Urolithin A suppresses glucolipotoxicity-induced ER stress and TXNIP/NLRP3/IL-1β inflammation signal in pancreatic β cells by regulating AMPK and autophagy

BACKGROUND

Pancreatic inflammation plays a key role in diabetes pathogenesis and progression. Urolithin A (UA), an intestinal flora metabolite of pomegranate, has anti-diabetic, anti-inflammatory and kidney protection effects among others. However, its effects on pancreatic inflammation and the potential mechanisms have not been clearly established.

PURPOSE

This study aimed at investigating the molecular mechanisms of UA anti-pancreatic inflammation under a diabetic environment.

METHODS

Diabetes induction in male C57BL/6 mice was achieved by a high fat diet and intraperitoneal streptozotocin injections. Then, diabetic mice were orally administered with UA for 8 weeks. In vitro, endoplasmic reticulum stress and MIN6 pancreatic β cell inflammation were induced using 25 mM glucose and 0.5 mM palmitic acid. The effects of UA were evaluated by immunohistochemistry, Western blot, and enzyme linked immunosorbent assays. Finally, the underlying mechanisms were elucidated using an autophagy inhibitor (chloroquine, CQ) and an AMPK inhibitor (dorsomorphin dihydrochloride).

RESULTS

UA significantly inhibited IL-1β secretion and TXNIP/NLRP3 expression in the pancreas of diabetic mice and in MIN6 pancreatic cells. UA downregulated the ER stress protein, p-PERK, and promoted AMPK phosphorylation. UA activated autophagy to inhibit TXNIP/NLRP3 IL-1β inflammatory signal, an effect that was reversed by CQ. Dorsomorphin 2HCL, reversed the autophagy-activation and anti-inflammatory effects of UA. Verapamil, clinically applied as an antiarrhythmic drug, is a TXNIP inhibitor for prevention of beta cell loss and diabetes development, but limited by its cardiac toxicity. In this study, verapamil (as positive control) inhibited NLRP3 /IL-1β signaling in MIN6 cells. Inhibitory effects of UA on TXNIP and IL-1β were weaker than those of verapamil (both at 50 μM, p < 0.05, p < 0.01). Conversely, inhibitory effects of UA on p62 were stronger, relative to those of verapamil (p < 0.05), and there were no differences in AMPK activation and LC3 enhancement effects between UA and verapamil.

CONCLUSION

UA is a potential anti-pancreatic inflammation agent that activates AMPK and autophagy to inhibit endoplasmic reticulum stress associated TXNIP/NLRP3/IL-1β signal pathway.

Cardiac cachexia: the mandate to increase clinician awareness

PURPOSE OF REVIEW

Heart failure is a frequent problem in an ageing population, associated with high rates of morbidity and mortality. Today, it is important to not only treat heart failure itself but also the related comorbidities. Among them, cardiac cachexia is one of the major challenges. It is a complex multifactorial disease with a negative impact on quality of life and prognosis. Therefore, prevention, early recognition and treatment of cardiac cachexia is essential.

RECENT FINDINGS

Cardiac cachexia frequently presents with skeletal as well as heart muscle depletion. Imaging-based diagnostic techniques can help to identify patients with cardiac cachexia and muscle wasting. Several blood biomarkers are available to detect metabolic changes in cardiac cachexia.

SUMMARY

Several studies are currently ongoing to better comprehend the underlying pathophysiological mechanisms of cardiac cachexia and to find new treatments. It is essential to diagnose it as early as possible to initiate therapy.

The Emerging Role of MicroRNAs and Other Non-Coding RNAs in Cancer Cachexia

Cancer cachexia or wasting is a paraneoplastic syndrome characterized by systemic inflammation and an involuntary loss of body mass that cannot be reversed by normal nutritional support. This syndrome affects 50%–80% of cancer patients, depending on the tumor type and patient characteristics, and it is responsible for up to 20% of cancer deaths. MicroRNAs are a class of non-coding RNAs (ncRNAs) with 19 to 24 nucleotides in length of which the function is to regulate gene expression. In the last years, microRNAs and other ncRNAs have been demonstrated to have a crucial role in the pathogenesis of several diseases and clinical potential. Recently, ncRNAs have begun to be associated with cancer cachexia by modulating essential functions like the turnover of skeletal muscle and adipose tissue. Additionally, circulating microRNAs have been suggested as potential biomarkers for patients at risk of developing cancer cachexia. In this review article, we present recent data concerning the role of microRNAs and other ncRNAs in cancer cachexia pathogenesis and their possible clinical relevance.

Urolithin A exerts antiobesity effects through enhancing adipose tissue thermogenesis in mice

Obesity leads to multiple health problems, including diabetes, fatty liver, and even cancer. Here, we report that urolithin A (UA), a gut-microflora-derived metabolite of pomegranate ellagitannins (ETs), prevents diet-induced obesity and metabolic dysfunctions in mice without causing adverse effects. UA treatment increases energy expenditure (EE) by enhancing thermogenesis in brown adipose tissue (BAT) and inducing browning of white adipose tissue (WAT). Mechanistically, UA-mediated increased thermogenesis is caused by an elevation of triiodothyronine (T3) levels in BAT and inguinal fat depots. This is also confirmed in UA-treated white and brown adipocytes. Consistent with this mechanism, UA loses its beneficial effects on activation of BAT, browning of white fat, body weight control, and glucose homeostasis when thyroid hormone (TH) production is blocked by its inhibitor, propylthiouracil (PTU). Conversely, administration of exogenous tetraiodothyronine (T4) to PTU-treated mice restores UA-induced activation of BAT and browning of white fat and its preventive role on high-fat diet (HFD)-induced weight gain. Together, these results suggest that UA is a potent antiobesity agent with potential for human clinical applications.

Dietary intake of probiotic kimchi ameliorated IL-6-driven cancer cachexia

Cancer cachexia is a syndrome accompanying weight loss, skeletal muscle atrophy, and loss of adipose tissue in patients with advanced cancer. Since interleukin-6 (IL-6) is one of core mediators causing cancer cachexia and kimchi can modulate IL-6 response, we hypothesized dietary intake of kimchi can ameliorate cancer cachexia. In this study, we studied preemptive administration of kimchi can ameliorate mouse colon carcinoma cells colon (C26) adenocarcinoma-induced cancer cachexia and explored anti-cachexic mechanisms of kimchi focused on the changes of muscle atrophy, cachexic inflammation, and catabolic catastrophe. As results, dietary intake of kimchi significantly attenuated the development of cancer cachexia, presented with lesser weight loss, higher muscle preservation as well as higher survival from cancer cachexia in mice. Starting from significant inhibition of IL-6 and its signaling, kimchi afforded significant inhibition of muscle specific ubiquitin-proteasome system including inhibition of atrogin-1 and muscle ring finger protein-1 (MuRF-1) with other muscle related genes including mitofusin-2 (Mfn-2) and PGC-1α. Significant inhibition of lipolysis gene such as adipose triglyceride lipase (ATGL) and hormone-sensitive ligase (HSL) accompanied with significant induction of fatty acid synthase (FAS) and sterol response element binding protein 1 (SREBP1) was achieved with kimchi. As gene regulation, IL-6 and their receptor as well as Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) were significantly attenuated with kimchi. In conclusion, dietary intake of cancer preventive kimchi can be an anticipating option to ameliorate cancer cachexia via suppressive action of IL-6 accompanied with decreased muscle atrophy and lipolysis.