Impact of Obesity on Cardiac Autonomic System Functioning in Military Police Officers

INTRODUCTION

Cardiac autonomic system functioning may be altered by obesity leading to cardiovascular diseases and associated complications. Military police officers are exposed to traditional and occupational risk factors for the development of CVD, however data on the cardiovascular health in this population is still scarce.

AIM

In this cross-sectional study, we investigated the impact of obesity on cardiac autonomic modulation and the hemodynamic profile in male active-duty military police officers.

METHODS

The body composition of the volunteers was assessed by octapolar electrical bioimpedance. Participants were classified as non-obese or obese in accordance with their body fat, with further subgroups as physically active obese or insufficiently active obese using International Physical Activity Questionnaire (IPAQ). Cardiac autonomic modulation was assessed by heart rate variability and the automatic oscillometric method allowed us to assess hemodynamic features.

RESULTS

102 military police officers from the state of São Paulo participated in the study. Cardiac autonomic modulation revealed significant impairment in time and frequency domains and non-linear methods in the obese group compared to the non-obese (p < 0.05). A higher physical activity level did not alter these results in the obese group. However, no significant differences in the hemodynamic profile were observed between groups (p > 0.05).

CONCLUSION

These findings suggest a negative association between obesity and cardiac autonomic modulation in military police officers, unaffected by increased physical activity.

Changes in Skeletal Muscle Protein Metabolism Signaling Induced by Glutamine Supplementation and Exercise

AIM

To evaluate the effects of resistance exercise training (RET) and/or glutamine supplementation (GS) on signaling protein synthesis in adult rat skeletal muscles.

METHODS

The following groups were studied: (1) control, no exercise (C); (2) exercise, hypertrophy resistance exercise training protocol (T); (3) no exercise, supplemented with glutamine (G); and (4) exercise and supplemented with glutamine (GT). The rats performed hypertrophic training, climbing a vertical ladder with a height of 1.1 m at an 80° incline relative to the horizontal with extra weights tied to their tails. The RET was performed three days a week for five weeks. Each training session consisted of six ladder climbs. The extra weight load was progressively increased for each animal during each training session. The G groups received daily L-glutamine by gavage (one g per kilogram of body weight per day) for five weeks. The C group received the same volume of water during the same period. The rats were euthanized, and the extensor digitorum longus (EDL) muscles from both hind limbs were removed and immediately weighed. Glutamine and glutamate concentrations were measured, and histological, signaling protein contents, and mRNA expression analyses were performed.

RESULTS

Supplementation with free L-glutamine increased the glutamine concentration in the EDL muscle in the C group. The glutamate concentration was augmented in the EDL muscles from T rats. The EDL muscle mass did not change, but a significant rise was reported in the cross-sectional area (CSA) of the fibers in the three experimental groups. The levels of the phosphorylated proteins (pAkt/Akt, pp70S6K/p70S6K, p4E-BP1/4E-BP1, and pS6/S6 ratios) were significantly increased in EDL muscles of G rats, and the activation of p4E-BP1 was present in T rats. The fiber CSAs of the EDL muscles in T, G, and GT rats were increased compared to the C group. These changes were accompanied by a reduction in the 26 proteasome activity of EDL muscles from T rats.

CONCLUSION

Five weeks of GS and/or RET induced muscle hypertrophy, as indicated by the increased CSAs of the EDL muscle fibers. The increase in CSA was mediated via the upregulated phosphorylation of Akt, 4E-BP1, p70S6k, and S6 in G animals and 4E-BP1 in T animals. In the EDL muscles from T animals, a decrease in proteasome activity, favoring a further increase in the CSA of the muscle fibers, was reported.

Linseed oil attenuates fatty liver disease in mice fed a high-carbohydrate diet

The impact of linseed oil as a lipid source on liver disease induced by a high-carbohydrate diet (HCD) was evaluated. Adult male Swiss mice received an HCD containing carbohydrates (72.1%), proteins (14.2%), and lipids (4.0%). The Control HCD group (HCD-C) received an HCD containing lard (3.6%) and soybean oil (0.4%) as lipid sources. The L10 and L100 groups received an HCD with 10 and 100% linseed oil as lipid sources, respectively. A group of mice were euthanized before receiving the diets (day 0) and the remaining groups after 56 days of receiving the diets (HCD-C, L10, and L-100 groups). Morphological and histopathological analyses, as well as collagen deposition were evaluated. Perivenous hepatocytes (PVH) of the HCD-C group were larger (P<0.05) than periportal hepatocytes (PPH) in the median lobe (ML) and left lobe (LL). There was a greater (P<0.05) deposition of type I collagen in PPH (vs PVH) and in the ML (vs LL). The ML exhibited a higher proportion of apoptotic bodies, inflammatory infiltrate, and hepatocellular ballooning. All these alterations (hepatocyte size, deposition of type I collagen, apoptotic bodies, inflammatory infiltrate, and hepatocellular ballooning) induced by HCD were prevented or attenuated in L10 and L100 groups. Another indicator of the beneficial effects of linseed oil was the lower (P<0.05) number of binucleated hepatocytes (HCD-C vs L10 or L100 group). In general, the L100 group had greater effects than the L10 group. In conclusion, linseed oil impedes or reduces the liver injury progression induced by an HCD.

Autophagy signaling in hypertrophied muscles of diabetic and control rats

Autophagy plays a vital role in cell homeostasis by eliminating nonfunctional components and promoting cell survival. Here, we examined the levels of autophagy signaling proteins after 7 days of overload hypertrophy in the extensor digitorum longus (EDL) and soleus muscles of control and diabetic rats. We compared control and 3-day streptozotocin-induced diabetic rats, an experimental model for type 1 diabetes mellitus (T1DM). EDL muscles showed increased levels of basal autophagy signaling proteins. The diabetic state did not affect the extent of overload-induced hypertrophy or the levels of autophagy signaling proteins (p-ULK1, Beclin-1, Atg5, Atg12-5, Atg7, Atg3, LC3-I and II, and p62) in either muscle. The p-ULK-1, Beclin-1, and p62 protein expression levels were higher in the EDL muscle than in the soleus before the hypertrophic stimulus. On the contrary, the soleus muscle exhibited increased autophagic signaling after overload-induced hypertrophy, with increases in Beclin-1, Atg5, Atg12-5, Atg7, Atg3, and LC3-I expression in the control and diabetic groups, in addition to p-ULK-1 in the control groups. After hypertrophy, Beclin-1 and Atg5 levels increased in the EDL muscle of both groups, while p-ULK1 and LC3-I increased in the control group. In conclusion, the baseline EDL muscle exhibited higher autophagy than the soleus muscle. Although TDM1 promotes skeletal muscle mass loss and strength reduction, it did not significantly alter the extent of overload-induced hypertrophy and autophagy signaling proteins in EDL and soleus muscles, with the two groups exhibiting different patterns of autophagy activation.

Brain glucose hypometabolism and hippocampal inflammation in Goto-Kakizaki rats

Brain glucose hypometabolism and neuroinflammation are early pathogenic manifestations in neurological disorders. Neuroinflammation may also disrupt leptin signaling, an adipokine that centrally regulates appetite and energy balance by acting on the hypothalamus and exerting neuroprotection in the hippocampus. The Goto-Kakizaki (GK) rat is a non-obese type 2 diabetes mellitus (T2DM) animal model used to investigate diabetes-associated molecular mechanisms without obesity jeopardizing effects. Wistar and GK rats received the maintenance adult rodent diet. Also, an additional control group of Wistar rats received a high-fat and high-sugar diet (HFHS) provided by free consumption of condensed milk. All diets and water were provided ad libitum for eight weeks. Brain glucose uptake was evaluated by 2-deoxy-2-[fluorine-18] fluoro-D-glucose under basal (saline administration) or stimulated (CL316,243, a selective β3-AR agonist) conditions. The animals were fasted for 10-12 h, anesthetized, and euthanized. The brain was quickly dissected, and the hippocampal area was sectioned and stored at -80°C in different tubes for protein and RNA analyses on the same animal. GK rats exhibited attenuated brain glucose uptake compared to Wistar animals and the HFHS group under basal conditions. Also, the hippocampus of GK rats displayed upregulated leptin receptor, IL-1β, and IL-6 gene expression and IL-1β and the subunit of the transcription factor NF-κB (p-p65) protein expression. No significant alterations were detected in the hippocampus of HFHS rats. Our data indicated that a genetic predisposition to T2DM has significant brain deteriorating features, including brain glucose hypometabolism, neuroinflammation, and leptin signaling disruption in the hippocampal area.

Essential metabolism required for T and B lymphocyte functions: an update

Lymphocytes act as regulatory and effector cells in inflammation and infection situations. A metabolic switch towards glycolytic metabolism predominance occurs during T lymphocyte differentiation to inflammatory phenotypes (Th1 and Th17 cells). Maturation of T regulatory cells, however, may require activation of oxidative pathways. Metabolic transitions also occur in different maturation stages and activation of B lymphocytes. Under activation, B lymphocytes undergo cell growth and proliferation, associated with increased macromolecule synthesis. The B lymphocyte response to an antigen challenge requires an increased adenosine triphosphate (ATP) supply derived mainly through glycolytic metabolism. After stimulation, B lymphocytes increase glucose uptake, but they do not accumulate glycolytic intermediates, probably due to an increase in various metabolic pathway 'end product' formation. Activated B lymphocytes are associated with increased utilization of pyrimidines and purines for RNA synthesis and fatty acid oxidation. The generation of plasmablasts and plasma cells from B lymphocytes is crucial for antibody production. Antibody production and secretion require increased glucose consumption since 90% of consumed glucose is needed for antibody glycosylation. This review describes critical aspects of lymphocyte metabolism and functional interplay during activation. We discuss the primary fuels for the metabolism of lymphocytes and the particularities of T and B cell metabolism, including the differentiation of lymphocytes, stages of development of B cells, and the production of antibodies.

Identification of pathogenic variants in the Brazilian cohort with Familial Hypercholesterolemia using exon-targeted gene sequencing

Familial hypercholesterolemia (FH) is a monogenic disease characterized by high plasma low-density lipoprotein cholesterol (LDL-c) levels and increased risk of premature atherosclerotic cardiovascular disease. Mutations in FH-related genes account for 40% of FH cases worldwide. In this study, we aimed to assess the pathogenic variants in FH-related genes in the Brazilian FH cohort FHBGEP using exon-targeted gene sequencing (ETGS) strategy. FH patients (n=210) were enrolled at five clinical sites and peripheral blood samples were obtained for laboratory testing and genomic DNA extraction. ETGS was performed using MiSeq platform (Illumina). To identify deleterious variants in LDLR, APOB, PCSK9, and LDLRAP1, the long-reads were subjected to Burrows-Wheeler Aligner (BWA) for alignment and mapping, followed by variant calling using Genome Analysis Toolkit (GATK) and ANNOVAR for variant annotation. The variants were further filtered using in-house custom scripts and classified according to the American College Medical Genetics and Genomics (ACMG) guidelines. A total of 174 variants were identified including 85 missense, 3 stop-gain, 9 splice-site, 6 InDel, and 71 in regulatory regions (3'UTR and 5'UTR). Fifty-two patients (24.7%) had 30 known pathogenic or likely pathogenic variants in FH-related genes according to the American College Medical and Genetics and Genomics guidelines. Fifty-three known variants were classified as benign, or likely benign and 87 known variants have shown uncertain significance. Four novel variants were discovered and classified as such due to their absence in existing databases. In conclusion, ETGS and in silico prediction studies are useful tools for screening deleterious variants and identification of novel variants in FH-related genes, they also contribute to the molecular diagnosis in the FHBGEP cohort.

Virulence Profiles of Wild-Type, P.1 and Delta SARS-CoV-2 Variants in K18-hACE2 Transgenic Mice

Since December 2019, the world has been experiencing the COVID-19 pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and we now face the emergence of several variants. We aimed to assess the differences between the wild-type (Wt) (Wuhan) strain and the P.1 (Gamma) and Delta variants using infected K18-hACE2 mice. The clinical manifestations, behavior, virus load, pulmonary capacity, and histopathological alterations were analyzed. The P.1-infected mice showed weight loss and more severe clinical manifestations of COVID-19 than the Wt and Delta-infected mice. The respiratory capacity was reduced in the P.1-infected mice compared to the other groups. Pulmonary histological findings demonstrated that a more aggressive disease was generated by the P.1 and Delta variants compared to the Wt strain of the virus. The quantification of the SARS-CoV-2 viral copies varied greatly among the infected mice although it was higher in P.1-infected mice on the day of death. Our data revealed that K18-hACE2 mice infected with the P.1 variant develop a more severe infectious disease than those infected with the other variants, despite the significant heterogeneity among the mice.

Fish Oil Supplementation Improves the Repeated-Bout Effect and Redox Balance in 20-30-Year-Old Men Submitted to Strength Training

Herein, we investigated the effect of fish oil supplementation combined with a strength-training protocol, for 6 weeks, on muscle damage induced by a single bout of strength exercise in untrained young men. Sixteen men were divided into two groups, supplemented or not with fish oil, and they were evaluated at the pre-training period and post-training period. We investigated changes before and 0, 24, and 48 h after a single hypertrophic exercise session. Creatine kinase (CK) and lactate dehydrogenase (LDH) activities, plasma interleukin-6 (IL-6) and C-reactive protein (CRP) levels, and the redox imbalance were increased in response to the single-bout session of hypertrophic exercises at baseline (pre-training period) and decreased during the post-training period in the control group due to the repeated-bout effect (RBE). The fish oil supplementation exacerbated this reduction and improved the redox state. In summary, our findings demonstrate that, in untrained young men submitted to a strength-training protocol, fish oil supplementation is ideal for alleviating the muscle injury, inflammation, and redox imbalance induced by a single session of intense strength exercises, highlighting this supplementation as a beneficial strategy for young men that intend to engage in strength-training programs.

Formyl peptide receptors are involved in CTX-induced impairment of lymphocyte functions

Crotoxin (CTX) is a neurotoxin that is isolated from the venom of Crotalus durissus terrificus, which displays immunomodulatory, anti-inflammatory, and anti-tumoral effects. Previous research has demonstrated that CTX promotes the adherence of leukocytes to the endothelial cells in blood microcirculation and the high endothelial venules of lymph nodes, which reduces the number of blood cells and lymphocytes. Studies have also shown that these effects are mediated by lipoxygenase-derived mediators. However, the exact lipoxygenase-derived eicosanoid involved in the CTX effect on lymphocytes is yet to be characterized. As CTX stimulates lipoxin-derived mediators from macrophages and lymphocyte effector functions could be modulated by activating formyl peptide receptors, we aimed to investigate whether these receptors were involved in CTX-induced redistribution and functions of lymphocytes in rats. We used male Wistar rats treated with CTX to demonstrate that Boc2 (butoxycarbonyl-Phe-Leu-Phe-Leu-Phe), an antagonist of formyl peptide receptors, prevented CTX-induced decrease in the number of circulating lymphocytes and increased the expression of the lymphocyte adhesion molecule LFA1. CTX reduced the T and B lymphocyte functions, such as lymphocyte proliferation in response to the mitogen Concanavalin A and antibody production in response to BSA immunization, respectively, which was prevented by the administration of Boc2. Importantly, mesenteric lymph node lymphocytes from CTX-treated rats showed an increased release of 15-epi-LXA₄. These results indicate that formyl peptide receptors mediate CTX-induced redistribution of lymphocytes and that 15-epi-LXA₄ is a key mediator of the immunosuppressive effects of CTX.

Hydrolyzed whey protein enriched with glutamine dipeptide attenuates skeletal muscle damage and improves physical exhaustion test performance in triathletes

Purpose

To investigate the effects of hydrolyzed whey protein enriched with glutamine dipeptide on the percentage of oxygen consumption, second ventilatory threshold, duration and total distance covered, and skeletal muscle damage during an exhaustion test in elite triathletes.

Methods

The study was a randomized, double-blinded, placebo-controlled, crossover trial. Nine male triathletes performed a progressive incremental test on a treadmill ergometer (1.4 km h^-1·3 min^-1) 30 min after ingesting either 50 g of maltodextrin plus four tablets of 700 mg hydrolyzed whey protein enriched with 175 mg of glutamine dipeptide diluted in 250 ml of water (MGln) or four tablets of 700 mg maltodextrin plus 50 g maltodextrin diluted in 250 ml of water (M). Each athlete was submitted to the two dietary treatments and two corresponding exhaustive physical tests with an interval of one week between the interventions. The effects of the two treatments were then compared within the same athlete. Maximal oxygen consumption, percentage of maximal oxygen consumption, second ventilatory threshold, and duration and total distance covered were measured during the exhaustion test. Blood was collected before and immediately after the test for the determination of plasma lactate dehydrogenase (LDH) and creatine kinase (CK) activities and lactate concentration (also measured 6, 10, and 15 min after the test). Plasma cytokines (IL-6, IL-1β, TNF-α, IL-8, IL-10, and IL-1ra) and C-reactive protein levels were also measured.

Results

A single dose of MGln increased the percentage of maximal oxygen consumption, second ventilatory threshold duration, and total distance covered during the exhaustion test and augmented plasma lactate levels 6 and 15 min after the test. MGln also decreased plasma LDH and CK activities indicating muscle damage protection. Plasma cytokine and C-reactive protein levels did not change across the study periods.

Conclusion

Conditions including overnight fasting and a single dose of MGln supplementation resulted in exercising at a higher percentage of maximal oxygen consumption, a higher second ventilatory threshold, blood lactate levels, and reductions in plasma markers of muscle damage during an exhaustion test in elite triathletes. These findings support oral glutamine supplementation's efficacy in triathletes, but further studies require.

Linseed Oil Attenuates Liver Inflammation, Fatty Acid Accumulation, and Lipid Distribution in Periportal and Perivenous Hepatocytes Induced by a High-Carbohydrate Diet in Mice

We evaluated whether linseed oil (LO) modulates the effects of a high-carbohydrate diet (HCD) on liver inflammation, fatty acid (FA) accumulation, and lipid distribution in periportal and perivenous hepatocytes. The control group (control high-carbohydrate diet [HCD-C]) received an HCD with lard and soybean oil as the lipid source. The L10 and L100 groups received the HCD with 10% and 100% of LO as the lipid source, respectively. The animals were killed by decapitation before (day 0) and after receiving the diets. Liver FA composition, inflammation, and fibrogenesis gene expression were evaluated. Also, the percentage of lipid-occupied area in periportal end perivenous hepatocytes were measured. The L100 group exhibited a higher (P < .05) liver amount of omega-3 polyunsaturated FA (n-3 PUFA) and lower (P < .05) amounts of saturated FA (SFA), monounsaturated FA (MUFA), and omega-6 polyunsaturated FA (n-6 PUFA) compared with L10 or HCD-C mice. On day 56, interleukin 10 and type IV collagen gene expression were significantly upregulated and downregulated, respectively in L100. Also, the L100 group showed lower (P < .05) FA accumulation (i.e., total FA, SFA, MUFA, and n-6 PUFA). Also, L10 and L100 presented lower (P < .05) percentage of high lipid-containing portion in periportal and perivenous hepatocytes. We concluded that LO attenuation of liver inflammation promoted by an HCD is associated with increased liver n-3 PUFA levels, so modulating FA composition, deposition, and distribution in periportal and perivenous hepatocytes.

Molecular and cellular mechanisms involved in tissue-specific metabolic modulation by SARS-CoV-2

Coronavirus disease 2019 (COVID-19) is triggered by the SARS-CoV-2, which is able to infect and cause dysfunction not only in lungs, but also in multiple organs, including central nervous system, skeletal muscle, kidneys, heart, liver, and intestine. Several metabolic disturbances are associated with cell damage or tissue injury, but the mechanisms involved are not yet fully elucidated. Some potential mechanisms involved in the COVID-19-induced tissue dysfunction are proposed, such as: (a) High expression and levels of proinflammatory cytokines, including TNF-α IL-6, IL-1β, INF-α and INF-β, increasing the systemic and tissue inflammatory state; (b) Induction of oxidative stress due to redox imbalance, resulting in cell injury or death induced by elevated production of reactive oxygen species; and (c) Deregulation of the renin-angiotensin-aldosterone system, exacerbating the inflammatory and oxidative stress responses. In this review, we discuss the main metabolic disturbances observed in different target tissues of SARS-CoV-2 and the potential mechanisms involved in these changes associated with the tissue dysfunction.

Leukocyte metabolism in obese type 2 diabetic individuals associated with COVID-19 severity

Recent studies show that the metabolic characteristics of different leukocytes, such as, lymphocytes, neutrophils, and macrophages, undergo changes both in the face of infection with SARS-CoV-2 and in obesity and type 2 diabetes mellitus (DM2) condition. Thus, the objective of this review is to establish a correlation between the metabolic changes caused in leukocytes in DM2 and obesity that may favor a worse prognosis during SARS-Cov-2 infection. Chronic inflammation and hyperglycemia, specific and usual characteristics of obesity and DM2, contributes for the SARS-CoV-2 replication and metabolic disturbances in different leukocytes, favoring the proinflammatory response of these cells. Thus, obesity and DM2 are important risk factors for pro-inflammatory response and metabolic dysregulation that can favor the occurrence of the cytokine storm, implicated in the severity and high mortality risk of the COVID-19 in these patients.

Maternal low-protein diet reduces skeletal muscle protein synthesis and mass via Akt-mTOR pathway in adult rats

Several studies have demonstrated that a maternal low-protein diet induces long-term metabolic disorders, but the involved mechanisms are unclear. This study investigated the molecular effects of a low-protein diet during pregnancy and lactation on glucose and protein metabolism in soleus muscle isolated from adult male rats. Female rats were fed either a normal protein diet or low-protein diet during gestation and lactation. After weaning, all pups were fed a normal protein diet until the 210th day postpartum. In the 7th month of life, mass, contractile function, protein and glucose metabolism, and the Akt-mTOR pathway were measured in the soleus muscles of male pups. Dry weight and contractile function of soleus muscle in the low-protein diet group rats were found to be lower compared to the control group. Lipid synthesis was evaluated by measuring palmitate incorporation in white adipose tissue. Palmitate incorporation was higher in the white adipose tissue of the low-protein diet group. When incubated soleus muscles were stimulated with insulin, protein synthesis, total amino acid incorporation and free amino acid content, glucose incorporation and uptake, and glycogen synthesis were found to be reduced in low-protein diet group rats. Fasting glycemia was higher in the low-protein diet group. These metabolic changes were associated with a decrease in Akt and GSK-3β signaling responses to insulin and a reduction in RPS6 in the absence of the hormone. There was also notably lower expression of Akt in the isolated soleus muscle of low-protein diet group rats. This study is the first to demonstrate how maternal diet restriction can reduce skeletal muscle protein and mass by downregulating the Akt-mTOR pathway in adulthood.

A short review on the features of the non-obese diabetic Goto-Kakizaki rat intestine

The Goto-Kakizaki (GK) rat is a non-obese experimental model of type 2 diabetes mellitus (T2DM) that allows researchers to monitor diabetes-induced changes without jeopardizing the effects of obesity. This rat strain exhibits notable gastrointestinal features associated with T2DM, such as marked alterations in intestinal morphology, reduced intestinal motility, slow transit, and modified microbiota compared to Wistar rats. The primary treatments for diabetic patients include administration of hypoglycemic agents and insulin, and lifestyle changes. Emerging procedures, including alternative therapies, metabolic surgeries, and modulation of the intestinal microbiota composition, have been shown to improve the diabetic state of GK rats. This review describes the morpho-physiological diabetic-associated features of the gastrointestinal tract (GIT) of GK rats. We also describe promising strategies, e.g., metabolic surgery and modulation of gut microbiota composition, used to target the GIT of this animal model to improve the diabetic state.

Crotoxin modulates metabolism and secretory activity of peritoneal macrophages from Walker 256 tumor-bearing rats

Crotoxin (CTX), the major toxin of Crotalus durissus terrificus snake venom, induces an inhibitory effect on tumor development and modulates the functions of macrophages (MØs), which play a key role as a defense mechanism against tumor growth. In early tumor progression stage, MØs are avidly phagocytic (inflammatory cell), releasing reactive nitrogen intermediates-RNI/ROI and cytokines TNF-α, IL-1β, and IL-6. However, when the tumor has been developed, tumor-associated MØ (angiogenic cell) presents a decrease in the mentioned activities. We reported that CTX stimulates H₂O₂ release, NO production and secretion of cytokines by peritoneal MØs obtained from non-tumor-bearing rats. Considering that the mentioned mediators control tumor growth, it is mandatory to investigate whether CTX stimulates the production of these mediators by MØs obtained from tumor-bearing animals. The aim of this work was then to evaluate the CTX effect on metabolism and functions of peritoneal MØs obtained from Walker 256 tumor-bearing rats. For this purpose, male Wistar rats were subcutaneously inoculated in the right flank with 1 mL sterile suspension of 2 × 10⁷ Walker 256 tumor cells. CTX (18 μg per animal) was subcutaneously administered in two protocols: a) on the 1st day of tumor cell injection and b) on the 4th day of tumor cell inoculation. In both protocols, MØs were obtaining on the 14th day of tumor cell inoculation to evaluate the release of H₂O_2, NO, and pro-inflammatory cytokines (IL-1β, TNFα, and IL-6); maximal activity of hexokinase, glucose-6-phosphate dehydrogenase, citrate synthase, and ¹⁴CO₂ production from [U-¹⁴C]-glucose and [U-¹⁴C]-glutamine. The treatment with CTX stimulated the release of NO, H₂O₂, and cytokines, and glucose and glutamine metabolism. Metabolic and functional changes induced by CTX were accompanied by a decrease of tumor growth as indicated by tumor fresh weight and diameter. These results indicate CTX not only as a scientific tool to investigate changes in metabolism and functions of peritoneal MØs but also for a better understanding of the mechanisms involved in tumor growth.

Evidence for a neuromuscular circuit involving hypothalamic interleukin-6 in the control of skeletal muscle metabolism

Hypothalamic interleukin-6 (IL6) exerts a broad metabolic control. Here, we demonstrated that IL6 activates the ERK1/2 pathway in the ventromedial hypothalamus (VMH), stimulating AMPK/ACC signaling and fatty acid oxidation in mouse skeletal muscle. Bioinformatics analysis revealed that the hypothalamic IL6/ERK1/2 axis is closely associated with fatty acid oxidation- and mitochondrial-related genes in the skeletal muscle of isogenic BXD mouse strains and humans. We showed that the hypothalamic IL6/ERK1/2 pathway requires the α2-adrenergic pathway to modify fatty acid skeletal muscle metabolism. To address the physiological relevance of these findings, we demonstrated that this neuromuscular circuit is required to underpin AMPK/ACC signaling activation and fatty acid oxidation after exercise. Last, the selective down-regulation of IL6 receptor in VMH abolished the effects of exercise to sustain AMPK and ACC phosphorylation and fatty acid oxidation in the muscle after exercise. Together, these data demonstrated that the IL6/ERK axis in VMH controls fatty acid metabolism in the skeletal muscle.

Equine Anti-SARS-CoV-2 Serum (ECIG) Binds to Mutated RBDs and N Proteins of Variants of Concern and Inhibits the Binding of RBDs to ACE-2 Receptor

The COVID-19 pandemic caused by the severe acute syndrome virus 2 (SARS-CoV-2) has been around since November 2019. As of early June 2022, more than 527 million cases were diagnosed, with more than 6.0 million deaths due to this disease. Coronaviruses accumulate mutations and generate greater diversity through recombination when variants with different mutations infect the same host. Consequently, this virus is predisposed to constant and diverse mutations. The SARS-CoV-2 variants of concern/interest (VOCs/VOIs) such as Alpha (B.1.1.7), Beta (B.1.351), Gamma (B.1.1.28/P.1), Delta (B.1.617.2), and Omicron (B.1.1.529) have quickly spread across the world. These VOCs and VOIs have accumulated mutations within the spike protein receptor-binding domain (RBD) which interacts with the angiotensin-2 converting enzyme (ACE-2) receptor, increasing cell entry and infection. The RBD region is the main target for neutralizing antibodies; however, other notable mutations have been reported to enhance COVID-19 infectivity and lethality. Considering the urgent need for alternative therapies against this virus, an anti-SARS-CoV-2 equine immunoglobulin F(ab’)2, called ECIG, was developed by the Butantan Institute using the whole gamma-irradiated SARS-CoV-2 virus. Surface plasmon resonance experiments revealed that ECIG binds to wild-type and mutated RBD, S1+S2 domains, and nucleocapsid proteins of known VOCs, including Alpha, Gamma, Beta, Delta, Delta Plus, and Omicron. Additionally, it was observed that ECIG attenuates the binding of RBD (wild-type, Beta, and Omicron) to human ACE-2, suggesting that it could prevent viral entry into the host cell. Furthermore, the ability to concomitantly bind to the wild-type and mutated nucleocapsid protein likely enhances its neutralizing activity of SARS-CoV-2. We postulate that ECIG benefits COVID-19 patients by reducing the infectivity of the original virus and existing variants and may be effective against future ones. Impacting the course of the disease, mainly in the more vulnerable, reduces infection time and limits the appearance of new variants by new recombination.

Hypertonic Solution in Severe COVID-19 Patient: A Potential Adjuvant Therapy

Coronavirus disease 2019 (COVID-19) features hyper-inflammation, cytokine storm, neutrophil function changes, and sodium chloride (NaCl) homeostasis disruption, while the treatment with NaCl hypertonic solutions (HS) controls electrolytic body homeostasis and cell functions. HS treatment is a simple, popular, economic, and feasible therapy to regulate leukocyte function with a robust anti-inflammatory effect in many inflammatory diseases. The purpose of this narrative review is to highlight the knowledge on the use of HS approaches against viral infection over the past years and to describe the mechanisms involved in the release of neutrophil extracellular traps (NETs) and production of cytokine in severe lung diseases, such as COVID-19. We reported the consequences of hyponatremia in COVID-19 patients, and the immunomodulatory effects of HS, either in vitro or in vivo. We also described the relationship between electrolyte disturbances and COVID-19 infection. Although there is still a lack of clinical trials, hypertonic NaCl solutions have marked effects on neutrophil function and NETs formation, emerging as a promising adjuvant therapy in COVID-19.

Detection of SARS-CoV-2 virus via dynamic light scattering using antibody-gold nanoparticle bioconjugates against viral spike protein

Mass testing for the diagnosis of COVID-19 has been hampered in many countries owing to the high cost of genetic material detection. This study reports on a low-cost immunoassay for detecting SARS-CoV-2 within 30 min using dynamic light scattering (DLS). The immunosensor comprises 50-nm gold nanoparticles (AuNPs) functionalized with antibodies against SARS-CoV-2 spike glycoprotein, whose bioconjugation was confirmed using transmission electron microscopy (TEM), UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), and surface-enhanced Raman scattering spectroscopy (SERS). The specific binding of the bioconjugates to the spike protein led to an increase in bioconjugate size, with a limit of detection (LOD) 5.29 × 10³ TCID₅₀/mL (Tissue Culture Infectious Dose). The immunosensor was also proven to be selective upon interaction with influenza viruses once no increase in size was observed after DLS measurement. The strategy proposed here aimed to use antibodies conjugated to AuNPs as a generic platform that can be extended to other detection principles, enabling technologies for low-cost mass testing for COVID-19.

Strenuous swimming raises blood non-enzymatic antioxidant capacity in rats

The non-enzymatic antioxidant system protects blood components from oxidative damage and/or injury. Herein, plasma non-enzymatic antioxidant capacity after acute strenuous swimming exercise (Exe) and exercise until exhaustion (Exh) was measured in rats. The experiments were carried out in never exposed (Nex) and pre-exposed (Pex) groups. The Nex group did not undergo any previous training before the acute strenuous swimming test and the Pex group was submitted to daily swimming for 10 min in the first week and 15 min per day in the second week before testing. Plasma glucose, lactate, and pyruvate were measured and plasma total protein sulfhydryl groups (thiol), trolox equivalent antioxidant capacity (TEAC), ferric reducing ability of plasma (FRAP), and total radical-trapping antioxidant parameter (TRAP) levels were evaluated. There were marked increases in plasma lactate concentrations (Nex-Control 1.31±0.20 vs NexExe 4.16±0.39 vs NexExh 7.19±0.67) and in thiol (Nex-Control 271.9±5.6 vs NexExh 314.7±5.7), TEAC (Nex-Control 786.4±60.2 vs NexExh 1027.7±58.2), FRAP (Nex-Control 309.2±17.7 vs NexExh 413.4±24.3), and TRAP (Nex-Control 0.50±0.15 vs NexExh 2.6±0.32) levels after acute swimming and/or exhaustion. Also, there were increased plasma lactate concentrations (Pex-Control 1.39±0.15 vs PexExe 5.22±0.91 vs PexExh 10.07±0.49), thiol (Pex-Control 252.9±8.2 vs PexExh 284.6±6.7), FRAP (Pex-Control 296.5±15.4 vs PexExh 445.7±45.6), and TRAP (Pex-Control 1.8±0.1 vs PexExh 4.6±0.2) levels after acute swimming and/or exhaustion. Lactate showed the highest percent of elevation in the Nex and Pex groups. In conclusion, plasma lactate may contribute to plasma antioxidant defenses, and the TRAP assay is the most sensitive assay for assessing plasma non-antioxidant capacity after strenuous exercise.

SARS-COV-2 Variants: Differences and Potential of Immune Evasion

The structural spike (S) glycoprotein of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) plays an essential role in infection and is an important target for neutralizing antibody recognition. Mutations in the S gene can generate variants of concern (VOCs), which improve “viral fitness” through selective or survival advantages, such as increased ACE-2 receptor affinity, infectivity, viral replication, higher transmissibility, resistance to neutralizing antibodies and immune escape, increasing disease severity and reinfection risk. Five VOCs have been recognized and include B.1.1.7 (U.K.), B.1.351 (South Africa), P.1 (Brazil), B.1.617.2 (India), and B.1.1.529 (multiple countries). In this review, we addressed the following critical points concerning VOCs: a) characteristics of the SARS-CoV-2 VOCs with mutations in the S gene; b) possible evasion of variants from neutralizing antibodies generated through vaccination, previous infection, or immune therapies; c) potential risk of new pandemic waves induced by the variants worldwide; and d) perspectives for further studies and actions aimed at preventing or reducing the impact of new variants during the current COVID-19 pandemic.

Reviewing physical exercise in non-obese diabetic Goto-Kakizaki rats

There is a high incidence of non-obese type 2 diabetes mellitus (non-obese-T2DM) cases, particularly in Asian countries, for which the pathogenesis remains mainly unclear. Interestingly, Goto-Kakizaki (GK) rats spontaneously develop insulin resistance (IR) and non-obese-T2DM, making them a lean diabetes model. Physical exercise is a non-pharmacological therapeutic approach to reduce adipose tissue mass, improving peripheral IR, glycemic control, and quality of life in obese animals or humans with T2DM. In this narrative review, we selected and analyzed the published literature on the effects of physical exercise on the metabolic features associated with non-obese-T2DM. Only randomized controlled trials with regular physical exercise training, freely executed physical activity, or skeletal muscle stimulation protocols in GK rats published after 2008 were included. The results indicated that exercise reduces plasma insulin levels, increases skeletal muscle glycogen content, improves exercise tolerance, protects renal and myocardial function, and enhances blood oxygen flow in GK rats.

Poor prognosis indicators of type-2 diabetic COVID-19 patients

Diabetes is associated with a worse prognosis and a high risk of morbidity and mortality in COVID-19 patients. We aimed to evaluate the main factors involved in the poor prognosis in diabetic patients. A total of 984 patients diagnosed with COVID-19 admitted to the hospital were included in this study. Patients were first divided into type-2 diabetic (DM+) and non-diabetic (DM–) groups. The participants were analyzed based on the National Early Warning Score (NEWS) and on the Quick-Sequential Organ Failure Assessment (qSOFA) to find the best prognostic risk score for our study. The DM+ and DM– groups were divided into non-severe and severe groups. Comparative and correlative analyses were used to identify the physiological parameters that could be employed for creating a potential risk indicator for DM+ COVID-19 patients. We found a poorer prognosis for the DM+ COVID-19 patients with a higher ICU admission rate, mechanical ventilation rate, vasopressor use, dialysis, and longer treatment times compared with the DM– group. DM+ COVID-19 patients had increased plasma glucose, lactate, age, urea, NEWS, and D-dimer levels, herein referred to as the GLAUND set, and worse prognosis and outcomes when compared with infected DM– patients. The NEWS score was a better indicator for assessing COVID-19 severity in diabetic patients than the q-SOFA score. In conclusion, diabetic COVID-19 patients should be assessed with the NEWS score and GLAUND set for determining their prognosis COVID-19 prognosis.

The Myristic Acid:Docosahexaenoic Acid Ratio Versus the n-6 Polyunsaturated Fatty Acid:n-3 Polyunsaturated Fatty Acid Ratio as Nonalcoholic Fatty Liver Disease Biomarkers

It is well established that diets containing an increased omega-6 polyunsaturated fatty acid (n-6 PUFA) to omega-3 polyunsaturated fatty acid (n-3 PUFA) ratios are linked to inflammation and chronic diseases such as nonalcoholic fatty liver disease (NAFLD). However, the influence of an elevated n-6 PUFA:n-3 PUFA ratio in the tissues requires clarification. Herein, we identified primary experimental and clinical studies where it is possible to compare the performance of the myristic acid (Myr):docosahexaenoic acid (DHA) and n-6 PUFA:n-3 PUFA ratios in the liver and/or serum as potential NAFLD biomarkers. Articles were included if quantitative values of n-6 PUFA, n-3 PUFA, Myr, DHA, and information about liver inflammation or liver disease progression parameters were provided. Overall, most experimental (91.6%) and clinical studies (87.5%) reported higher Myr:DHA ratios associated with inflammation and/or NAFLD progression than the n-6 PUFA:n-3 PUFA ratio. We conclude that the Myr:DHA ratio represents a better biomarker of NAFLD than the n-6 PUFA:n-3 PUFA ratio. Future studies are necessary for verifying this observation.

Antimicrobial resistance of Listeria monocytogenes human strains and correlation to genomic data

Background

Studies checking antimicrobial resistance (AMR) of Listeria monocytogenes (Lm) are ongoing, coupled with disease surveillance. Lm resistant strains are reported and are increasing. The aim of the work was to investigate AMR of clinical strains of Lm collected from nine regions (mostly in Lombardy and Marche regions) from 2008 to 2020.

Methods

The dataset consisted of 233 Lm human strains collected from nine regions during the period 2008-2020. All the strains were tested using Sensititre™ Haemophilus Plate (Thermo Scientific, Milano, Italy). Results were expressed according to EUCAST breakpoints for Lm, S. pneumoniae and E. faecalis. Resistant strains were sequenced using Illumina platform, ABRicate was used to predict antimicrobial resistance genes and plasmids.

Results

Most of the strains were detected in Lombardy and Marche. The MIC results showed that 11 out of 233 strains were resistant, one to ampicillin, four to tetracycline and six to clarithromycin. Analysing the sequences, all the resistant strains showed to have a common antimicrobial resistant pattern (mprF, norB, FosX, (MLS)lin, lin and lmo0919). Genomic determinants for ampicillin and clarithromycin resistance were not detected. Indeed, only in 3 out of 4 resistant strains tetM was found. Meanwhile, plasmids were detected in 7 strains.

Conclusions

The distribution of the strains considered in this work did not reflect the real epidemiological situation in Italy, because their origin was mostly from two regions. The emergence of AMR also for Lm needs to be considered. Moreover, official breakpoints for Lm are not defined and to date limited to five antimicrobials excluding clarithromycin and tetracycline, where the pathogen showed resistance. Finally, the incongruence between phenotypic and genomic data suggests that the mechanisms involved in the resistance is not fully known especially for ampicillin. Further investigations are needed to improve the knowledge on Lm AMR.

Key messages

Monitoring AMR of Listeria monocytogenes is crucial, only effective drug in clinical cases should be used. Further investigations are needed to explore the mechanisms involved in antimicrobial resistance of Listeria monocytogenes.

Prefrontal Cortex and Hippocampus Inflammation in Mice Fed High-Carbohydrate or High-Fat Diets

We previously reported that a high-carbohydrate diet (HCD) induced systemic inflammation and higher gene expression of proinflammatory mediators in the liver, skeletal muscle, and brain than a high-fat diet (HFD). However, the differences between the groups were less pronounced in the brain. In this study, we extended the evaluation of inflammation to specific areas of the brain. In this study, we evaluated the gene expression of caspase 2, caspase 3, caspase 9, cyclooxygenase-2 (Cox 2), inducible nitric oxide synthase (iNOS), interleukin (IL), IL-6, IL-1β, IL-10, IL-4, tumor necrosis factor-alpha (TNF-α), integrin subunit alpha m (Itgam), S100 protein (S100), allograft inflammatory factor 1 (Aif1), and glial fibrillary acidic protein (Gfap) in the prefrontal cortex and hippocampus of male Swiss mice that were fed with HCD or HFD for 8 weeks. The HCD group exhibited higher IL-1β expression, whereas the HFD group showed higher TNF-α expression in the prefrontal cortex. In the hippocampus, TNF-α expression was higher in the HFD group. IL-1β and TNF-α are proinflammatory cytokines that have been associated with impaired brain function and numerous brain disorders. Our results indicate that both HCD and HFD promote prefrontal cortex inflammation; however, the hippocampus seems more sensitive to a HFD than HCD.

Impaired brown adipose tissue is differentially modulated in insulin-resistant obese wistar and type 2 diabetic Goto-Kakizaki rats

Brown adipose tissue (BAT) is a potential target to treat obesity and diabetes, dissipating energy as heat. Type 2 diabetes (T2D) has been associated with obesogenic diets; however, T2D was also reported in lean individuals to be associated with genetic factors. We aimed to investigate the differences between obese and lean models of insulin resistance (IR) and elucidate the mechanism associated with BAT metabolism and dysfunction in different IR animal models: a genetic model (lean GK rats) and obese models (diet-induced obese Wistar rats) at 8 weeks of age fed a high-carbohydrate (HC), high-fat (HF) diet, or high-fat and high-sugar (HFHS) diet for 8 weeks. At 15 weeks of age, BAT glucose uptake was evaluated by 18F-FDG PET under basal (saline administration) or stimulated condition (CL316,243, a selective β3-AR agonist). After CL316, 243 administrations, GK animals showed decreased glucose uptake compared to HC animals. At 16 weeks of age, the animals were euthanized, and the interscapular BAT was dissected for analysis. Histological analyses showed lower cell density in GK rats and higher adipocyte area compared to all groups, followed by HFHS and HF compared to HC. HFHS showed a decreased batokine FGF21 protein level compared to all groups. However, GK animals showed increased expression of genes involved in fatty acid oxidation (CPT1 and CPT2), BAT metabolism (Sirt1 and Pgc1-α), and obesogenic genes (leptin and PAI-1) but decreased gene expression of glucose transporter 1 (GLUT-1) compared to other groups. Our data suggest impaired BAT function in obese Wistar and GK rats, with evidence of a whitening process in these animals.

A simple mathematical model for the evaluation of the long first wave of the COVID-19 pandemic in Brazil

We propose herein a mathematical model to predict the COVID-19 evolution and evaluate the impact of governmental decisions on this evolution, attempting to explain the long duration of the pandemic in the 26 Brazilian states and their capitals well as in the Federative Unit. The prediction was performed based on the growth rate of new cases in a stable period, and the graphics plotted with the significant governmental decisions to evaluate the impact on the epidemic curve in each Brazilian state and city. Analysis of the predicted new cases was correlated with the total number of hospitalizations and deaths related to COVID-19. Because Brazil is a vast country, with high heterogeneity and complexity of the regional/local characteristics and governmental authorities among Brazilian states and cities, we individually predicted the epidemic curve based on a specific stable period with reduced or minimal interference on the growth rate of new cases. We found good accuracy, mainly in a short period (weeks). The most critical governmental decisions had a significant temporal impact on pandemic curve growth. A good relationship was found between the predicted number of new cases and the total number of inpatients and deaths related to COVID-19. In summary, we demonstrated that interventional and preventive measures directly and significantly impact the COVID-19 pandemic using a simple mathematical model. This model can easily be applied, helping, and directing health and governmental authorities to make further decisions to combat the pandemic.

The Immunometabolic Roles of Various Fatty Acids in Macrophages and Lymphocytes

Macrophages and lymphocytes demonstrate metabolic plasticity, which is dependent partly on their state of activation and partly on the availability of various energy yielding and biosynthetic substrates (fatty acids, glucose, and amino acids). These substrates are essential to fuel-based metabolic reprogramming that supports optimal immune function, including the inflammatory response. In this review, we will focus on metabolism in macrophages and lymphocytes and discuss the role of fatty acids in governing the phenotype, activation, and functional status of these important cells. We summarize the current understanding of the pathways of fatty acid metabolism and related mechanisms of action and also explore possible new perspectives in this exciting area of research.

Physical exercise increases global and gene-specific (interleukin-17 and interferon-γ) DNA methylation in lymphocytes from aged women

NEW FINDINGS

What is the central question of this study? Is lymphocyte DNA methylation differentially modulated by resistance training and aerobic exercise in older women? What is the main finding and its importance? The practice of resistance training led to an increased global DNA methylation in lymphocytes. The exercise-induced increase of inflammatory genes methylation may be associated with immune function impairment during ageing.

ABSTRACT

Ageing-induced increase in inflammatory gene expression through a reduction in DNA methylation might contribute to chronic diseases. Regular physical exercise practices, in turn, are associated with a decrease in the incidence of inflammatory diseases. We herein evaluated the effects of three exercise modalities on lymphocyte global and gene-specific (interferon γ (IFN-γ) and interleukin 17A (IL-17A) DNA methylation in aged women (68 ± 7.5 years). This cross-sectional study included 86 women, divided into four groups according to the physical exercise practice: 20 were practicing resistance training (RT); 24 were practicing water aerobics exercise (W); 22 were practicing water aerobics and resistance exercise (RWT), and 20 did not practice any physical exercise (CON). We evaluated volunteer functional capability using the Timed Up and Go (TUG) test, global lymphocyte DNA methylation by enzyme-linked immunosorbent assay, IFN-γ and IL-17A methylation by qPCR and CD4⁺ IFN-γ⁺ and CD4⁺ IL-17⁺ cell percentage by flow cytometry. The three physically exercised groups performed functional capability tests in a shorter period and showed a higher global lymphocyte DNA methylation and methylated CpGs of IL-17A and IFN-γ promoter regions than the control group. The practice of resistance training (RT and RWT groups) lead to high global DNA methylation. The combination of resistance training and aerobic exercise led to the increase of lymphocyte IL-17A and IFN-γ gene methylation induced by each separately. However, the percentage of IFN-γ⁺ and IL-17⁺ cells was lower only in the RT group. The exercise-induced increase of inflammatory-gene methylation may be associated with gene expression changes and immune function impairment during ageing.

Endoplasmic Reticulum Stress and Autophagy Markers in Soleus Muscle Disuse-Induced Atrophy of Rats Treated with Fish Oil

Endoplasmic reticulum stress (ERS) and autophagy pathways are implicated in disuse muscle atrophy. The effects of high eicosapentaenoic (EPA) or high docosahexaenoic (DHA) fish oils on soleus muscle ERS and autophagy markers were investigated in a rat hindlimb suspension (HS) atrophy model. Adult Wistar male rats received daily by gavage supplementation (0.3 mL per 100 g b.w.) of mineral oil or high EPA or high DHA fish oils (FOs) for two weeks. Afterward, the rats were subjected to HS and the respective treatments concomitantly for an additional two-week period. After four weeks, we evaluated ERS and autophagy markers in the soleus muscle. Results were analyzed using two-way analysis of variance (ANOVA) and Bonferroni post hoc test. Gastrocnemius muscle ω-6/ω-3 fatty acids (FAs) ratio was decreased by both FOs indicating the tissue incorporation of omega-3 fatty acids. HS altered (p < 0.05) the protein content (decreasing total p38 and BiP and increasing p-JNK2/total JNK2 ratio, and caspase 3) and gene expressions (decreasing BiP and increasing IRE1 and PERK) of ERS and autophagy (decreasing Beclin and increasing LC3 and ATG14) markers in soleus. Both FOs attenuated (p < 0.05) the increase in PERK and ATG14 expressions induced by HS. Thus, both FOs could potentially attenuate ERS and autophagy in skeletal muscles undergoing atrophy.

Features of Neutrophils From Atopic and Non-Atopic Elite Endurance Runners

We collected peripheral blood from thirty-nine elite male endurance runners at rest (24 hours after the last exercise session) and used the Allergy Questionnaire for Athletes score and plasma specific IgE level to separate them into atopic and non-atopic athletes. Neutrophils obtained from atopic and non-atopic athletes were subsequently stimulated in vitro with fMLP (N-formyl-methionyl-leucyl-phenylalanine), LPS (lipopolysaccharide), or PMA (phorbol 12-myristate 13-acetate). Neutrophils from non-atopic runners responded appropriately to LPS, as evidenced by the production of pro (IL-8, TNF-α, and IL-6) and anti-inflammatory (IL-10) cytokines. Neutrophils from atopic elite runners exhibited lower responses to LPS stimulus as indicated by no increase in IL-1β, TNF-α, and IL-6 production. Neutrophils from non-atopic and atopic runners responded similarly to fMLP stimulation, indicating that migration function remained unaltered. Both groups were unresponsive to PMA induced reactive oxygen species (ROS) production. Training hours and training volume were not associated with neutrophil IgE receptor gene expression or any evaluated neutrophil function. Since non-atopic runners normally responded to LPS stimulation, the reduced neutrophil response to the stimuli was most likely due to the atopic state and not exercise training. The findings reported are of clinical relevance because atopic runners exhibit a constant decline in competition performance and are more susceptible to invading microorganisms.

A probiotic has differential effects on allergic airway inflammation in A/J and C57BL/6 mice and is correlated with the gut microbiome

The phenotypes of allergic airway diseases are influenced by the interplay between host genetics and the gut microbiota, which may be modulated by probiotics. We investigated the probiotic effects on allergic inflammation in A/J and C57BL/6 mice. C57BL/6 mice had increased gut microbiota diversity compared to A/J mice at baseline. Acetate producer probiotics differentially modulated and altered the genus abundance of specific bacteria, such as Akkermansia and Allistipes, in mouse strains. We induced airway inflammation followed by probiotic treatment and found that only A/J mice exhibited decreased inflammation, and the beneficial effects of probiotics in A/J mice were partially due to acetate production. To understand the relevance of microbial composition colonization in the development of allergic diseases, we implanted female C57BL/6 mice with A/J embryos to naturally modulate the microbial composition of A/J mice, which increased gut microbiota diversity and reduced eosinophilic inflammation in A/J. These data demonstrate the central importance of microbiota to allergic phenotype severity. Video Abstract.

Updating futsal physiology, immune system, and performance

Futsal promotes stress by handling the ball, physical contact, and exhaustive muscle contractions, elevating the risks for injury, oxidative stress, and inflammation after a training session or a match. In this review, we critically evaluate the more recent advances in the performance and health of futsal players. We searched the effects of futsal on performance, physiological parameters, muscle injury, inflammation, and oxidative stress. Although the stressful factors apply to all futsal players, goalkeepers require special attention during the competition and the recovery phase. We also show that the FIFA injury prevention programme, called The 11+, is effective in improving athletic performance and avoiding injury in futsal players. Research with different training durations and intensities and a wider range of studies involving oxidative stress, inflammation, and physiological mechanisms are of interest to design a more precise map of the biochemical regulation of training load and competition season in futsal.

Fatty acid oxidation participates in resistance to nutrient-depleted environments in the insect stages of Trypanosoma cruzi

Trypanosoma cruzi, the parasite causing Chagas disease, is a digenetic flagellated protist that infects mammals (including humans) and reduviid insect vectors. Therefore, T. cruzi must colonize different niches in order to complete its life cycle in both hosts. This fact determines the need of adaptations to face challenging environmental cues. The primary environmental challenge, particularly in the insect stages, is poor nutrient availability. In this regard, it is well known that T. cruzi has a flexible metabolism able to rapidly switch from carbohydrates (mainly glucose) to amino acids (mostly proline) consumption. Also established has been the capability of T. cruzi to use glucose and amino acids to support the differentiation process occurring in the insect, from replicative non-infective epimastigotes to non-replicative infective metacyclic trypomastigotes. However, little is known about the possibilities of using externally available and internally stored fatty acids as resources to survive in nutrient-poor environments, and to sustain metacyclogenesis. In this study, we revisit the metabolic fate of fatty acid breakdown in T. cruzi. Herein, we show that during parasite proliferation, the glucose concentration in the medium can regulate the fatty acid metabolism. At the stationary phase, the parasites fully oxidize fatty acids. [U-14C]-palmitate can be taken up from the medium, leading to CO2 production. Additionally, we show that electrons are fed directly to oxidative phosphorylation, and acetyl-CoA is supplied to the tricarboxylic acid (TCA) cycle, which can be used to feed anabolic pathways such as the de novo biosynthesis of fatty acids. Finally, we show as well that the inhibition of fatty acids mobilization into the mitochondrion diminishes the survival to severe starvation, and impairs metacyclogenesis.

High serum miR-421 is associated with metabolic dysregulation and inflammation in patients with metabolic syndrome

Aim: To explore the association of circulating miRNAs with adiposity, metabolic status and inflammatory biomarkers in patients with metabolic syndrome (MetS). Methods: Serum levels of 372 miRNAs were measured in patients with (n = 6) and without MetS (n = 6) by quantitative PCR array, and dysregulated miRNAs were validated in a larger cohort (MetS, n = 89; non-MetS, n = 144). Results: In the screening study, seven miRNAs were dysregulated in patients with MetS, and miR-421 remained increased in the validation study. miR-421 was associated with a high risk of MetS and insulin resistance and hypertension and correlated with glycated hemoglobin, triacylglycerols, high-sensitivity CRP, IL-6, resistin and adiponectin (p < 0.05). Conclusion: Circulating miR-421 is a potential biomarker for insulin resistance, metabolic dysregulation and inflammatory status in patients with MetS.

4-Aminoquinoline compounds from the Spanish flu to COVID-19

In 1918, quinine was used as one of the unscientifically based treatments against the H1N1 virus during the Spanish flu pandemic. Originally, quinine was extracted from the bark of Chinchona trees by South American natives of the Amazon forest, and it has been used to treat fever since the seventeenth century. The recent COVID-19 pandemic caused by Sars-Cov-2 infection has forced researchers to search for ways to prevent and treat this disease. Based on the antiviral potential of two 4-aminoquinoline compounds derived from quinine, known as chloroquine (CQ) and hydroxychloroquine (HCQ), clinical investigations for treating COVID-19 are being conducted worldwide. However, there are some discrepancies among the clinical trial outcomes.Thus, even after one hundred years of quinine use during the Spanish flu pandemic, the antiviral properties promoted by 4-aminoquinoline compounds remain unclear. The underlying molecular mechanisms by which CQ and HCQ inhibit viral replication open up the possibility of developing novel analogs of these drugs to combat COVID-19 and other viruses.

Why Septic Patients Remain Sick After Hospital Discharge?

Sepsis is well known to cause a high patient death rate (up to 50%) during the intensive care unit (ICU) stay. In addition, sepsis survival patients also exhibit a very high death rate after hospital discharge compared to patients with any other disease. The addressed question is then: why septic patients remain ill after hospital discharge? The cellular and molecular mechanisms involved in the high rate of septic patient deaths are still unknown. We described herein the studies that investigated the percentage of septic patients that died after hospital discharge ranging from 90 days up to 5 years. We also reported the symptoms of septic patients after hospital discharge and the development of the recently called post-sepsis syndrome (PSS). The most common symptoms of the PSS are cognitive disabilities, physical functioning decline, difficulties in performing routine daily activities, and poor life quality. The PSS also associates with quite often reinfection and re-hospitalization. This condition is the cause of the high rate of death mentioned above. We reported the proportion of patients dying after hospital discharge up to 5 years of followed up and the PSS symptoms associated. The authors also discuss the possible cellular and metabolic reprogramming mechanisms related with the low survival of septic patients and the occurrence of PSS.

A High-Fat Diet Induces Lower Systemic Inflammation than a High-Carbohydrate Diet in Mice

Background: We previously established that male Swiss mice (Mus musculus) receiving a high-fat diet (HFD) during 8 weeks exhibit similar caloric ingestion and body weight (grams) compared with mice fed a high-carbohydrate diet (HCD). HFD mice exhibit a lower inflammatory state than an HCD in the liver, skeletal muscle, and brain. In addition, we demonstrated that HFD and HCD modulated fatty acids (FA) composition in these tissues. In this study, our objective was to compare HFD mice and HCD mice in terms of systemic inflammation. Methods: Saturated FA (SFA), monounsaturated FA, omega-6 polyunsaturated FA (n-6 PUFA), and n-3 PUFA were evaluated at the time points 0, 1, 7, 14, 28, and 56 days after starting the administration of the diets. We investigated n-6 PUFA:n-3 PUFA, SFA:n-3 PUFA, palmitic acid:α-linolenic acid (ALA), and myristic acid:docosahexaenoic acid (DHA) ratios as potential serum biomarkers of systemic inflammation. We also measured the serum levels of basic fibroblast growth factor, granulocyte-macrophage colony-stimulating factor (GM-CSF), inducible protein 10 (IP-10), interferon gamma (IFN-γ), interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-13, IL-17, macrophage inflammatory protein-1α (MIP-1-α), monocyte chemotactic protein 1 (MCP-1), monokine induced by IFN-γ (MIG), and tumor necrosis factor α (TNF-α). Results: The HFD group had lower (P < 0.05) n-6 PUFA:n-3 PUFA, palmitic acid:ALA, myristic acid:DHA ratios, and lower plasma levels of proinflammatory cytokines (IFN-γ, MIG, GM-CSF, and IL-6). Conclusion: The HFD mice showed lower systemic inflammation compared with a caloric ingestion-body weight-matched control HCD mice.

Sensing soluble uric acid by Naip1-Nlrp3 platform

Uric acid (UA), a product of purine nucleotide degradation able to initiate an immune response, represents a breakpoint in the evolutionary history of humans, when uricase, the enzyme required for UA cleavage, was lost. Despite being inert in human cells, UA in its soluble form (sUA) can increase the level of interleukin-1β (IL-1β) in murine macrophages. We, therefore, hypothesized that the recognition of sUA is achieved by the Naip1-Nlrp3 inflammasome platform. Through structural modelling predictions and transcriptome and functional analyses, we found that murine Naip1 expression in human macrophages induces IL-1β expression, fatty acid production and an inflammation-related response upon sUA stimulation, a process reversed by the pharmacological and genetic inhibition of Nlrp3. Moreover, molecular interaction experiments showed that Naip1 directly recognizes sUA. Accordingly, Naip may be the sUA receptor lost through the human evolutionary process, and a better understanding of its recognition may lead to novel anti-hyperuricaemia therapies.

Profiling plasma-extracellular vesicle proteins and microRNAs in diabetes onset in middle-aged male participants in the ELSA-Brasil study

We measured plasma-derived extracellular vesicle (EV) proteins and their microRNA (miRNA) cargos in normoglycemic (NG), glucose intolerant (GI), and newly diagnosed diabetes mellitus (DM) in middle-aged male participants of the Brazilian Longitudinal Study of Adult Health (ELSA-Brazil). Mass spectrometry revealed decreased IGHG-1 and increased ITIH2 protein levels in the GI group compared with that in the NG group and higher serotransferrin in EVs in the DM group than in those in the NG and GI groups. The GI group also showed increased serum ferritin levels, as evaluated by biochemical analysis, compared with those in both groups. Seventeen miRNAs were differentially expressed (DEMiRs) in the plasma EVs of the three groups. DM patients showed upregulation of miR-141-3p and downregulation of miR-324-5p and -376c-3p compared with the NG and GI groups. The DM and GI groups showed increased miR-26b-5p expression compared with that in the NG group. The DM group showed decreased miR-374b-5p levels compared with those in the GI group and higher concentrations than those in the NG group. Thus, three EV proteins and five DEMiR cargos have potential prognostic importance for diabetic complications mainly associated with the immune function and iron status of GI and DM patients.

Small intestine remodeling in male Goto-Kakizaki rats

BACKGROUND

Obesity is associated with the development of insulin resistance (IR) and type-2 diabetes mellitus (T2DM); however, not all patients with T2DM are obese. The Goto-Kakizaki (GK) rat is an experimental model of spontaneous and non-obese T2DM. There is evidence that the intestine contributes to IR development in GK animals. This information prompted us to investigate small intestine remodeling in this animal model.

METHODS

Four-month-old male Wistar (control) and GK rats were utilized for the present study. After removing the small intestine, the duodenum, proximal jejunum, and distal ileum were separated. We then measured villi and muscular and mucosa layer histomorphometry, goblet cells abundance, total myenteric and submucosal neuron populations, and inflammatory marker expression in the small intestinal segments and intestinal transit of both groups of animals.

KEY RESULTS

We found that the GK rats exhibited decreased intestinal area (p < 0.0001), decreased crypt depth in the duodenum (p = 0.01) and ileum (p < 0.0001), increased crypt depth in the jejunum (p < 0.0001), longer villi in the jejunum and ileum (p < 0.0001), thicker villi in the duodenum (p < 0.01) and ileum (p < 0.0001), thicker muscular layers in the duodenum, jejunum, and ileum (p < 0.0001), increased IL-1β concentrations in the duodenum and jejunum (p < 0.05), and increased concentrations of NF-κB p65 in the duodenum (p < 0.01), jejunum and ileum (p < 0.05). We observed high IL-1β reactivity in the muscle layer, myenteric neurons, and glial cells of the experimental group. GK rats also exhibited a significant reduction in submucosal neuron density in the jejunum and ileum, ganglionic hypertrophy in all intestinal segments studied (p < 0.0001), and a slower intestinal transit (about 25%) compared to controls.

CONCLUSIONS

The development of IR and T2DM in GK rats is associated with small intestine remodeling that includes marked alterations in small intestine morphology, local inflammation, and reduced intestinal transit.

Macrophage inflammatory state in Type 1 diabetes: triggered by NLRP3/iNOS pathway and attenuated by docosahexaenoic acid

Type 1 diabetes mellitus (T1D) is a chronic autoimmune disease characterized by insulin-producing pancreatic β-cell destruction and hyperglycemia. While monocytes and NOD-like receptor family-pyrin domain containing 3 (NLRP3) are associated with T1D onset and development, the specific receptors and factors involved in NLRP3 inflammasome activation remain unknown. Herein, we evaluated the inflammatory state of resident peritoneal macrophages (PMs) from genetically modified non-obese diabetic (NOD), NLRP3-KO, wild-type (WT) mice and in peripheral blood mononuclear cells (PBMCs) from human T1D patients. We also assessed the effect of docosahexaenoic acid (DHA) on the inflammatory status. Macrophages from STZ-induced T1D mice exhibited increased inflammatory cytokine/chemokine levels, nitric oxide (NO) secretion, NLRP3 and iNOS protein levels, and augmented glycolytic activity compared to control animals. In PMs from NOD and STZ-induced T1D mice, DHA reduced NO production and attenuated the inflammatory state. Furthermore, iNOS and IL-1β protein expression levels and NO production were lower in the PMs from diabetic NLRP3-KO mice than from WT mice. We also observed increased IL-1β secretion in PBMCs from T1D patients and immortalized murine macrophages treated with advanced glycation end products and palmitic acid. The present study demonstrated that the resident PMs are in a proinflammatory state characterized by increased NLRP3/iNOS pathway-mediated NO production, up-regulated proinflammatory cytokine/chemokine receptor expression and altered glycolytic activity. Notably, ex vivo treatment with DHA reverted the diabetes-induced changes and attenuated the macrophage inflammatory state. It is plausible that DHA supplementation could be employed as adjuvant therapy for treating individuals with T1D.

The Critical Role of Cell Metabolism for Essential Neutrophil Functions

Neutrophils were traditionally considered as short-lived cells with abundant secretory and protein synthetic activity. Recent studies, however, indicate neutrophils are in reality a heterogeneous population of cells. Neutrophils differentiate from pluripotent stem cells in the bone marrow, and can further mature in the blood stream and can have different phenotypes in health and disease conditions. Neutrophils undergo primary functions such as phagocytosis, production of reactive oxygen species (ROS), release of lipid mediators and inflammatory proteins (mainly cytokines), and apoptosis. Neutrophils stimulate other neutrophils and trigger a cascade of immune and inflammatory responses. The underpinning intracellular metabolisms that support these neutrophil functions are herein reported. It has been known for many decades that neutrophils utilize glucose as a primary fuel and produce lactate as an end product of glycolysis. Neutrophils metabolize glucose through glycolysis and the pentose- phosphate pathway (PPP). Mitochondrial glucose oxidation is very low. The PPP provides the reduced nicotinamide adenine dinucleotide phosphate (NADPH) for the NADPH-oxidase (NOX) complex activity to produce superoxide from oxygen. These cells also utilize glutamine and fatty acids to produce the required adenosine triphosphate (ATP) and precursors for the synthesis of molecules that trigger functional outcomes. Neutrophils obtained from rat intraperitoneal cavity and incubate for 1 hour at 37°C metabolize glutamine at higher rate than that of glucose. Glutamine delays neutrophil apoptosis and maintains optimal NOX activity for superoxide production. Under limited glucose provision, neutrophils move to fatty acid oxidation (FAO) to obtain the required energy for the cell function. FAO is mainly associated with neutrophil differentiation and maturation. Hypoxia, hormonal dysfunction, and physical exercise markedly change neutrophil metabolism. It is now become clear that neutrophil metabolism underlies the heterogeneity of neutrophil phenotypes and should be intense focus of investigation.