Arachidonic acid inhibition of the NLRP3 inflammasome is a mechanism to explain the anti-inflammatory effects of fasting.

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Canakinumab in patients with COVID-19 and type 2 diabetes - A multicentre, randomised, double-blind, placebo-controlled trial

BACKGROUND: Patients with type 2 diabetes and obesity have chronic activation of the innate immune system possibly contributing to the higher risk of hyperinflammatory response to SARS-CoV2 and severe COVID-19 observed in this population. We tested whether interleukin-1β (IL-1β) blockade using canakinumab improves clinical outcome. METHODS: CanCovDia was a multicenter, randomised, double-blind, placebo-controlled trial to assess the efficacy of canakinumab plus standard-of-care compared with placebo plus standard-of-care in patients with type 2 diabetes and a BMI > 25 kg/m$^{2}$ hospitalised with SARS-CoV2 infection in seven tertiary-hospitals in Switzerland. Patients were randomly assigned 1:1 to a single intravenous dose of canakinumab (body weight adapted dose of 450-750 mg) or placebo. Canakinumab and placebo were compared based on an unmatched win-ratio approach based on length of survival, ventilation, ICU stay and hospitalization at day 29. This study is registered with ClinicalTrials.gov, NCT04510493. FINDINGS: Between October 17, 2020, and May 12, 2021, 116 patients were randomly assigned with 58 in each group. One participant dropped out in each group for the primary analysis. At the time of randomization, 85 patients (74·6 %) were treated with dexamethasone. The win-ratio of canakinumab vs placebo was 1·08 (95 % CI 0·69-1·69; p = 0·72). During four weeks, in the canakinumab vs placebo group 4 (7·0%) vs 7 (12·3%) participants died, 11 (20·0 %) vs 16 (28·1%) patients were on ICU, 12 (23·5 %) vs 11 (21·6%) were hospitalised for more than 3 weeks, respectively. Median ventilation time at four weeks in the canakinumab vs placebo group was 10 [IQR 6.0, 16.5] and 16 days [IQR 14.0, 23.0], respectively. There was no statistically significant difference in HbA1c after four weeks despite a lower number of anti-diabetes drug administered in patients treated with canakinumab. Finally, high-sensitive CRP and IL-6 was lowered by canakinumab. Serious adverse events were reported in 13 patients (11·4%) in each group. INTERPRETATION: In patients with type 2 diabetes who were hospitalised with COVID-19, treatment with canakinumab in addition to standard-of-care did not result in a statistically significant improvement of the primary composite outcome. Patients treated with canakinumab required significantly less anti-diabetes drugs to achieve similar glycaemic control. Canakinumab was associated with a prolonged reduction of systemic inflammation. FUNDING: Swiss National Science Foundation grant #198415 and University of Basel. Novartis supplied study medication

Arachidonic acid inhibition of the NLRP3 inflammasome is a mechanism to explain the anti-inflammatory effects of fasting

Summary: Elevated interleukin (IL)-1β levels, NLRP3 inflammasome activity, and systemic inflammation are hallmarks of chronic metabolic inflammatory syndromes, but the mechanistic basis for this is unclear. Here, we show that levels of plasma IL-1β are lower in fasting compared to fed subjects, while the lipid arachidonic acid (AA) is elevated. Lipid profiling of NLRP3-stimulated mouse macrophages shows enhanced AA production and an NLRP3-dependent eicosanoid signature. Inhibition of cyclooxygenase by nonsteroidal anti-inflammatory drugs decreases eicosanoid, but not AA, production. It also reduces both IL-1β and IL-18 production in response to NLRP3 activation. AA inhibits NLRP3 inflammasome activity in human and mouse macrophages. Mechanistically, AA inhibits phospholipase C activity to reduce JNK1 stimulation and hence NLRP3 activity. These data show that AA is an important physiological regulator of the NLRP3 inflammasome and explains why fasting reduces systemic inflammation and also suggests a mechanism to explain how nonsteroidal anti-inflammatory drugs work

High-fat diet reprograms the epigenome of rat spermatozoa and transgenerationally affects metabolism of the offspring

Objectives: Chronic and high consumption of fat constitutes an environmental stress that leads to metabolic diseases. We hypothesized that high-fat diet (HFD) transgenerationally remodels the epigenome of spermatozoa and metabolism of the offspring. Methods: F0-male rats fed either HFD or chow diet for 12 weeks were mated with chow-fed dams to generate F1 and F2 offspring. Motile spermatozoa were isolated from F0 and F1 breeders to determine DNA methylation and small non-coding RNA (sncRNA) expression pattern by deep sequencing. Results: Newborn offspring of HFD-fed fathers had reduced body weight and pancreatic beta-cell mass. Adult female, but not male, offspring of HFD-fed fathers were glucose intolerant and resistant to HFD-induced weight gain. This phenotype was perpetuated in the F2 progeny, indicating transgenerational epigenetic inheritance. The epigenome of spermatozoa from HFD-fed F0 and their F1 male offspring showed common DNA methylation and small non-coding RNA expression signatures. Altered expression of sperm miRNA let-7c was passed down to metabolic tissues of the offspring, inducing a transcriptomic shift of the let-7c predicted targets. Conclusion: Our results provide insight into mechanisms by which HFD transgenerationally reprograms the epigenome of sperm cells, thereby affecting metabolic tissues of offspring throughout two generations. Keywords: Epigenetics, Obesity, Spermatozoa, DNA methylation, microRN

Exercise in vivo marks human myotubes in vitro: Training-induced increase in lipid metabolism.

BACKGROUND AND AIMS:Physical activity has preventive as well as therapeutic benefits for overweight subjects. In this study we aimed to examine effects of in vivo exercise on in vitro metabolic adaptations by studying energy metabolism in cultured myotubes isolated from biopsies taken before and after 12 weeks of extensive endurance and strength training, from healthy sedentary normal weight and overweight men. METHODS:Healthy sedentary men, aged 40-62 years, with normal weight (body mass index (BMI) < 25 kg/m2) or overweight (BMI ≥ 25 kg/m2) were included. Fatty acid and glucose metabolism were studied in myotubes using [14C]oleic acid and [14C]glucose, respectively. Gene and protein expressions, as well as DNA methylation were measured for selected genes. RESULTS:The 12-week training intervention improved endurance, strength and insulin sensitivity in vivo, and reduced the participants' body weight. Biopsy-derived cultured human myotubes after exercise showed increased total cellular oleic acid uptake (30%), oxidation (46%) and lipid accumulation (34%), as well as increased fractional glucose oxidation (14%) compared to cultures established prior to exercise. Most of these exercise-induced increases were significant in the overweight group, whereas the normal weight group showed no change in oleic acid or glucose metabolism. CONCLUSIONS:12 weeks of combined endurance and strength training promoted increased lipid and glucose metabolism in biopsy-derived cultured human myotubes, showing that training in vivo are able to induce changes in human myotubes that are discernible in vitro

Effects of 12 weeks of exercise on myotube expression of lipid metabolism associated genes.

<p>Satellite cells isolated from biopsies from <i>m</i>. <i>vastus lateralis</i> before and after 12 weeks of exercise were cultured and differentiated to myotubes. mRNA was isolated and expression assessed by qPCR. <b>(A)</b> mRNA expression after exercise relative to before exercise for all participants combined. All values were corrected for the housekeeping control <i>GAPDH</i>, and presented as means ± SEM (n = 18). <b>(B)</b> mRNA expression after exercise relative to before exercise for study group when separated by BMI. All values were corrected for the housekeeping control <i>GAPDH</i>, and presented as means ± SEM (n = 7 in the normal weight group and n = 11 in the overweight group).</p

List of materials and respective producers.

<p>List of materials and respective producers.</p

Effects of 12 weeks of exercise on myotube AMPKα phosphorylation.

<p>Satellite cells isolated from biopsies from <i>m</i>. <i>vastus lateralis</i> before and after 12 weeks of exercise were cultured and differentiated to myotubes. <b>(A-C)</b> AMPKα phosphorylation by immunoblotting. Protein was isolated and total AMPKα and pAMPKα expressions assessed by immunoblotting. A, one representative immunoblot. Bands selected from one membrane have been spliced together to show only relevant samples, as indicated by lines separating the spliced blots. B, quantified immunoblots for participants combined (n = 9) relative to before exercise. C, quantified immunoblots for study group when separated by BMI relative to normal weight before exercise (n = 5 in the normal weight group and n = 4 in the overweight group). Values are presented as means ± SEM. All samples were derived at the same time and processed in parallel.</p