Cytokines and Abnormal Glucose and Lipid Metabolism

Network Pharmacology Study to Interpret Signaling Pathways of Ilex cornuta Leaves against Obesity

Ilex cornuta Leaves (ICLs) are a representative and traditional prescription for controlling obesity. Nevertheless, the corresponding therapeutic compounds and related pharmacological mechanisms of such medication remain undocumented. The compounds from ICLs were identified by gas chromatography-mass spectrum (GC-MS), and SwissADME confirmed their physicochemical properties. Next, the target proteins related to compounds or obesity-associated proteins were retrieved from public databases. RPackage constructed the protein–protein interaction (PPI) network, a bubble chart, and signaling pathways–target proteins–compounds (STC) network. Lastly, a molecular docking test (MDT) was performed to evaluate the affinity between target proteins and ligands from ICLs. GC-MS detected a total of 51 compounds from ICLs. The public databases identified 219 target proteins associated with selective compounds, 3028 obesity-related target proteins, and 118 overlapping target proteins. Moreover, the STC network revealed 42 target proteins, 22 signaling pathways, and 39 compounds, which were viewed to be remedially significant. The NOD-like receptor (NLR) signaling pathway was considered a key signaling pathway from the bubble chart. In parallel, the MDT identified three target proteins (IL6, MAPK1, and CASP1) on the NLR signaling pathway and four compounds against obesity. Overall, four compounds from ICLs might show anti-obesity synergistic efficacy by inactivating the NLR signaling pathway.

Phytochemical profiling, in vitro and in vivo anti-inflammatory, analgesic and antipyretic potential of Sesuvium sesuvioides (Fenzl) Verdc. (Aizoaceae)

Sesuvium sesuvioides (Fenzl) Verdc is traditionally used in the treatment of inflammatory diseases such as arthritis and gout The aim of present study was to assess the possible anti-inflammatory, analgesic and antipyretic potential of the methanol extract of Sesuvium sesuvioides (SsCr) to prove scientifically its folklore use in the inflammatory diseases and to screen its total antioxidant capacity by multiple methods and phytocompounds by GC-MS. The preliminary phytochemical studies showed the presence of phenols, flavonoids, glycosides, coumarin, terpenoids, saponins, fats and carbohydrates in crude extract. The total phenolic contents (27.31 ± 0.28 mg GAE/g) and total flavonoids (3.58 ± 0.12 mgRE/g) values were observed. The antioxidant capacity of SsCr showed significant DPPH, ABTS, CUPRAC, FRAP, PBD and metal chelating results. GC-MS analysis displayed the phytoconstituents with anti-inflammatory potentials such as 2-methoxy-4-vinylphenol, vanillin, umbelliferone, methyl ferulate, palmitoleic acid, methyl palmitate and phytol. SsCr presented noteworthy HRBC membrane stability with maximum inhibition of cell hemolysis (47.79%). In carrageenan-induced hind paw edema assay result showed dose-dependent anti-inflammatory action. SsCr presented significant (p < 0.05) analgesic activity in hot-plate and tail flicking tests similarly it also showed the noteworthy inhibition in pain latency against formalin induced analgesia at 1st and 2nd phases. SsCr reduced the acetic acid-induced writhes at different doses (250, 500 and 750 mg). Results of antipyretic activity of SsCr extract were significant at 500 and 750 mg. The results of in vitro and in vivo experimental studies verified the anti-inflammatory, analgesic and antipyretic potential of Sesuvium sesuvioides and supported the folklore uses of this plant.

MH-76, a Novel Non-Quinazoline α1-Adrenoceptor Antagonist, but Not Prazosin Reduces Inflammation and Improves Insulin Signaling in Adipose Tissue of Fructose-Fed Rats

Background: Quinazoline α₁-adrenoceptors antagonists have been shown to exert moderately favorable effects on the metabolic profile in hypertensive patients. However, based on AntiHypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) results, they are no longer recommended as a first line therapy of hypertension. Recent studies have shown that quinazoline-based α₁-adrenoceptors antagonists (prazosin, doxazosin) induce the apoptosis and necrosis, which may be responsible for ALLHAT outcomes; however, these effects were proven to be independent of α₁-adrenoceptor blockade and were associated with the presence of quinazoline moiety. MH-76 (1-[3-(2,6-dimethylphenoxy)propyl]-4-(2-methoxyphenyl)piperazine hydrochloride)) is a non-quinazoline α₁-adrenoceptor antagonist which, in fructose-fed rats, exerted antihypertensive effect, and, contrary to prazosin, reduced insulin resistance and abdominal adiposity. In this study we aimed to further investigate and compare the effects of MH-76 and prazosin on inflammation in adipose tissue of fructose-fed rats. Methods: Abdominal adipose tissue was collected from four groups of fructose-fed rats (Control, Fructose, Fructose + MH-76 and Fructose + Prazosin) and subjected to biochemical, histopathological and immunohistochemical studies. Moreover, selected tissue distribution studies were performed. Results: Treatment with MH-76 but not with prazosin improved endothelial integrity, reduced adipose tissue inflammation and infiltration by immune cells, resulting in lowering leptin, MCP-1, IL-6, TNF-α and PAI-1 levels. In adipose tissue from Fructose + MH-76 animals, a higher amount of eosinophils accompanied with higher IL-4 concentration was observed. Treatment with MH-76 but not with prazosin markedly reduced phosphorylation of IRS-1 at Ser307. Conclusion: MH-76 may improve insulin signaling in adipose tissue by reducing the pro-inflammatory cytokine production and inhibiting the inflammatory cells recruitment. In contrast, in adipose tissue from animals treated with prazosin, the inflammatory effect was clearly enhanced.

A bioactive fraction of Pterocarpus santalinus inhibits adipogenesis and inflammation in 3T3-L1 cells via modulation of PPAR-γ/SREBP-1c and TNF-α/IL-6

Pterocarpus santalinus has huge demand owing to its commercial and medicinal value. However, there are limited research studies on its therapeutic activity against obesity and obesity-induced inflammation and underlying mechanism of action. Therefore, in the present study, chloroform bioactive fraction of P. santalinus (CFP) was isolated and evaluated for its activity against adipogenesis and adipogenesis-induced inflammation in 3T3-L1 cell culture model. LC-MS/MS analysis of CFP was performed to identify the compounds present. CFP-treated 3T3-L1 cells (50, 100 and 200 μg/ml) have significantly (p < 0.01 or < 0.05) enhanced glycerol release and adiponectin level, but reduced lipid accumulation and leptin, and MTT assay demonstrated CFP was non-toxic till a dose of 300 µg/ml at 24 and 48 h. A considerable reduction in tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels was witnessed in lipopolysaccharide (LPS)-induced 3T3-L1 cells with CFP treatment in dose-dependent manner. Gene expression studies demonstrated down-regulation of mRNA expression of peroxisome proliferator-activated receptor-γ (PPAR-γ), sterol regulatory element-binding protein-1c (SREBP-1c), leptin, TNF-α and IL-6 but up-regulation of adiponectin and uncoupling protein-1 (UCP-1) and the same trend was observed in protein expression also. In conclusion, it is suggested that CFP could be beneficial to treat obesity and associated inflammation.

Deletion of mucin 2 induces colitis with concomitant metabolic abnormalities in mice

Patients with inflammatory bowel disease (IBD) are at increased risk of under-recognized metabolic comorbidities. Chronic intestinal inflammation in IBD along with changes to the gut microbiome leads to broader systemic effects. Despite the existence of multiple animal models to study colitis, limited studies have examined the metabolic abnormalities associated with these models. In this study, a spontaneous model of colitis (mucin 2 knock-out mouse, Muc2^-/-) was used to investigate the impact of intestinal disease on metabolic dysfunction. Before the onset of severe colitis, such as rectal prolapse, Muc2^-/- mice exhibited impaired glucose clearance. Defects were noted in the insulin signaling pathway corresponding with upregulated genes in lipid utilization pathways, increased mitochondrial number, and peroxisome proliferator-activated coactivator 1α (PGC-1α), a transcription factor central to energy metabolism regulation. Parallel to these metabolic alterations, Muc2^-/- mice exhibited systemic inflammation and bacteremia. We further characterized the dysbiotic microbiome's predicted functional categories given its contributing role to the colitic phenotype in the Muc2^-/- mice. In addition to less butyrate levels, we show an increased predisposition to lipid metabolism and lipid biosynthesis pathways in the microbiome associated with the host's altered metabolic state. This study establishes the Muc2^-/- mouse model that develops spontaneous colitis, as an ideal model for studying early comorbid metabolic dysfunction. Clarification of the underlying etiology of two phenotypes in this model could unravel important clues regarding the treatment of metabolic comorbidities during colitis.NEW & NOTEWORTHY This study discloses the impaired systemic energy metabolism in a classic colitis murine model (Muc2^-/- knock-out model). Investigating the interaction between colitis and metabolic disorders helps to extend our knowledge on deciphering inflammatory bowel disease-associated comorbidities and provides new insight into clinical treatment.

Interaction of Adiponectin Genotypes and Insulin Resistance on the Occurrence of Taiwanese Metabolic Syndrome

Backgrounds

Adiponectin (apM1) may affect insulin sensitivity, and tumor necrosis factor (TNF-α) can inhibit the binding of insulin and insulin receptors. However, whether apM1 and TNF-α genes influence the development of metabolic syndrome (MetS) preceded by insulin resistance is unclear. The current study examines the interactions between the apM1 +45 genotypes, TNF-α -308 genotypes, and insulin resistance on the occurrence of MetS.

Methods

A total of 329 community residents were recruited, and their personal characteristics were collected. Waist circumference and biochemical markers were examined for determining MetS. Genotypes were identified by the polymerase chain reaction.

Results

After adjusting for the confounding effects, compared to apM1 +45 GG and GT genotypes carriers with HOMR-IR less than 2.0, those carriers with HOMA-IR greater than 2.0 had an increased MetS risk (OR = 4.35, 95% CI 2.14-8.85). Further, apM1 +45 TT carriers with HOMA-IR greater than 2.0 experienced a higher MetS risk (OR = 5.91, 95% CI 2.78-12.54). A significant interaction of the apM1 +45 genotype and insulin resistance on the MetS development was observed (P = 0.04).

Conclusion

Our data suggested that apM1 +45 genotypes might modify the effect of insulin resistance on the development of Taiwanese MetS.

Ceramide kinase regulates TNF-α-induced immune responses in human monocytic cells

Ceramide kinase (CERK) phosphorylates ceramide to produce ceramide-1-phosphate (C1P), which is involved in the development of metabolic inflammation. TNF-α modulates inflammatory responses in monocytes associated with various inflammatory disorders; however, the underlying mechanisms remain not fully understood. Here, we investigated the role of CERK in TNF-α-induced inflammatory responses in monocytes. Our results show that disruption of CERK activity in monocytes, either by chemical inhibitor NVP-231 or by small interfering RNA (siRNA), results in the defective expression of inflammatory markers including CD11c, CD11b and HLA-DR in response to TNF-α. Our data show that TNF-α upregulates ceramide phosphorylation. Inhibition of CERK in monocytes significantly reduced the secretion of IL-1β and MCP-1. Similar results were observed in CERK-downregulated cells. TNF-α-induced phosphorylation of JNK, p38 and NF-κB was reduced by inhibition of CERK. Additionally, NF-κB/AP-1 activity was suppressed by the inhibition of CERK. Clinically, obese individuals had higher levels of CERK expression in PBMCs compared to lean individuals, which correlated with their TNF-α levels. Taken together, these results suggest that CERK plays a key role in regulating inflammatory responses in human monocytes during TNF-α stimulation. CERK may be a relevant target for developing novel therapies for chronic inflammatory diseases.

Lactobacillus paracasei DTA81, a cholesterol-lowering strain having immunomodulatory activity, reveals gut microbiota regulation capability in BALB/c mice receiving high-fat diet

Aims

In‐vitro/In‐vivo evaluation of cholesterol‐lowering probiotic strain Lactobacillus paracasei DTA81 and the possible connection with the gut microbiota modulation.

Methods and Results

In the present study, strain DTA81 has been evaluated for the possible influence on blood lipid and glucose concentrations, modulation of the immune system, gastrointestinal survivability and modulation of gut microbiota in BALB/c mice receiving a high‐fat diet. After 6 weeks of treatment, a significant reduction of total cholesterol and fasting blood sugar (FBS) among animals treated with L. paracasei DTA81 has been recorded. Comparison of colon tissue levels of different cytokines revealed a significant reduction of the inflammatory cytokine interleukin‐6. The comparison of gut microbiota using the 16S rRNA approach indicated that the treatment with L. paracasei DTA81 significantly increased the taxa Bacteroidetes and Coprococcus. Moreover, the genome of DTA81 was sequenced for the in‐silico assessment, and the analysis indicated the presence of cholesterol assimilation‐related genes as well as the absence of negative traits such as transmissible antibiotic resistance genes, plasmids and prophage regions.

Conclusion

The outcome of this study revealed the in‐vitro and in‐vivo properties of L. paracasei DTA81 and the possible mechanism between consumption of this strain, the abundance of Bacteriodetes/Coprococcus taxa, immunomodulatory activity and the subsequent reduction of cholesterol/FBS in BALB/c mice.

Significance and Impact of the Study

Lactobacillus paracasei DTA81 as a non‐pharmacological potential probiotic supplement can influence metabolic homeostasis in individuals, particularly those adopting high‐fat diets, and it can contribute to reduce coronary heart disease.

Adipokines, Myokines, and Hepatokines: Crosstalk and Metabolic Repercussions

Adipose, skeletal, and hepatic muscle tissues are the main endocrine organs that produce adipokines, myokines, and hepatokines. These biomarkers can be harmful or beneficial to an organism and still perform crosstalk, acting through the endocrine, paracrine, and autocrine pathways. This study aims to review the crosstalk between adipokines, myokines, and hepatokines. Far beyond understanding the actions of each biomarker alone, it is important to underline that these cytokines act together in the body, resulting in a complex network of actions in different tissues, which may have beneficial or non-beneficial effects on the genesis of various physiological disorders and their respective outcomes, such as type 2 diabetes mellitus (DM2), obesity, metabolic syndrome, and cardiovascular diseases (CVD). Overweight individuals secrete more pro-inflammatory adipokines than those of a healthy weight, leading to an impaired immune response and greater susceptibility to inflammatory and infectious diseases. Myostatin is elevated in pro-inflammatory environments, sharing space with pro-inflammatory organokines, such as tumor necrosis factor-alpha (TNF-α), interleukin-1 (IL-1), resistin, and chemerin. Fibroblast growth factor FGF21 acts as a beta-oxidation regulator and decreases lipogenesis in the liver. The crosstalk mentioned above can interfere with homeostatic disorders and can play a role as a potential therapeutic target that can assist in the methods of diagnosing metabolic syndrome and CVD.

Polarization of Macrophages in Insects: Opening Gates for Immuno-Metabolic Research

Insulin resistance and cachexia represent severe metabolic syndromes accompanying a variety of human pathological states, from life-threatening cancer and sepsis to chronic inflammatory states, such as obesity and autoimmune disorders. Although the origin of these metabolic syndromes has not been fully comprehended yet, a growing body of evidence indicates their possible interconnection with the acute and chronic activation of an innate immune response. Current progress in insect immuno-metabolic research reveals that the induction of insulin resistance might represent an adaptive mechanism during the acute phase of bacterial infection. In Drosophila, insulin resistance is induced by signaling factors released by bactericidal macrophages as a reflection of their metabolic polarization toward aerobic glycolysis. Such metabolic adaptation enables them to combat the invading pathogens efficiently but also makes them highly nutritionally demanding. Therefore, systemic metabolism has to be adjusted upon macrophage activation to provide them with nutrients and thus support the immune function. That anticipates the involvement of macrophage-derived systemic factors mediating the inter-organ signaling between macrophages and central energy-storing organs. Although it is crucial to coordinate the macrophage cellular metabolism with systemic metabolic changes during the acute phase of bacterial infection, the action of macrophage-derived factors may become maladaptive if chronic or in case of infection by an intracellular pathogen. We hypothesize that insulin resistance evoked by macrophage-derived signaling factors represents an adaptive mechanism for the mobilization of sources and their preferential delivery toward the activated immune system. We consider here the validity of the presented model for mammals and human medicine. The adoption of aerobic glycolysis by bactericidal macrophages as well as the induction of insulin resistance by macrophage-derived factors are conserved between insects and mammals. Chronic insulin resistance is at the base of many human metabolically conditioned diseases such as non-alcoholic steatohepatitis, atherosclerosis, diabetes, and cachexia. Therefore, revealing the original biological relevance of cytokine-induced insulin resistance may help to develop a suitable strategy for treating these frequent diseases.

Glyphosate-induced lipid metabolism disorder contributes to hepatotoxicity in juvenile common carp

Residues of glyphosate (GLY) are widely detected in aquatic systems, raising potential environmental threats and public health concerns, but the mechanism underlying GLY-induced hepatotoxicity in fish has not been fully elucidated yet. This study was designed to explore the hepatotoxic mechanism using juvenile common carp exposed to GLY for 45 d, and plasma and liver samples were collected at 15 d, 30 d, and 45 d to analyze the assays. First, GLY-induced hepatic damage was confirmed by serum liver damage biomarker and hepatic histopathological analysis. Next, changes in oxidative stress biomarkers, gene expression levels of pro- and anti-inflammatory cytokines, and lipid metabolism-related parameters in collected samples were analyzed to clarify their roles in GLY-induced hepatic damage. Data showed that oxidative stress was an early event during GLY exposure, followed by hepatic inflammatory response. Lipid metabolism disorder was a late event during GLY exposure, as evidenced by overproduced hepatic free fatty acids, enhanced lipogenesis-related gene expression levels, reduced lipolysis-related gene expression levels, and resultant hepatic lipid accumulation. Collectively, these findings demonstrate that GLY induces hepatotoxicity in fish through involvement of oxidative stress, inflammatory response, and lipid metabolism disorder, which are intimately interrelated with each other during GLY exposure.

The Involvement of Selenium in Type 2 Diabetes Development Related to Obesity and Low Grade Inflammation

BACKGROUND

Effects of the micronutrient selenium have been proposed in obesity and type 2 diabetes mellitus (T2DM) that involve impairments in glucose metabolic pathways and the insulin signaling cascade, mediated through oxidative stress and inflammation. However, the evidence collected to date through animal and epidemiologic studies has been inconclusive. Therefore, in the present study, we aimed to evaluate the relationships of selenium status and inflammation with T2DM and obesity.

METHODS

Participants in the re-survey of the Electricity Generating Authority of Thailand (EGAT)2 study conducted in 2013 (N=655, age 45-60 years) were allocated to three groups based on their body mass index (World Health Organization Asia-Pacific Classification), and their serum selenium and high-sensitivity C-reactive protein (hs-CRP) concentrations and other clinical parameters were compared.

RESULTS

Significant differences in serum selenium and hs-CRP among the groups were associated with differences in fasting blood glucose and glycated hemoglobin, as well as differences in the prevalence of prediabetes or T2DM. The adjusted odds ratios (ORs) (95% confidence intervals) for prediabetes or diabetes were 1.991 (1.318-3.009) and 3.786 (2.087-6.896) for the lowest and highest tertiles of serum selenium concentration in the entire sample and obese participants, respectively. Furthermore, the rising extent of hs-CRP increased the significantly associated with prediabetes or diabetes (adjusted ORs; 2.268 for the entire sample, 4.043 for the overweight and 1.910 for the obesity).

CONCLUSION

Selenium status may be linked to both obesity and T2DM through its effects on signaling pathways. Further nutrigenomic studies are required to clarify the relationship between selenium and metabolic diseases.

Amelioration of high-fat diet-induced obesity and its associated complications by a myricetin derivative-rich fraction from Syzygium malaccense in C57BL/6J mice

Obesity is a driving factor in the onset of metabolic disorders. This study aims to investigate the effects of the myricetin derivative-rich fraction (MD) from Syzygium malaccense leaf extract on high-fat diet (HFD)-induced obesity and its associated complications and its influence on uncoupling protein-1 (UCP-1) and gut microbiota in C57BL/6J mice. Mice were randomly assigned into four groups (n = 6) and given a normal diet (ND) or high-fat diet (HFD) for 10 weeks to induce obesity. The HFD groups (continued with HFD) were administered 50 mg kg-1 MD (treatment), 50 mg kg-1 metformin (positive control) and normal saline (HFD and ND controls) daily for four weeks via oral gavage. The ten-week HFD-feeding resulted in hyperglycemia and elevated urinary oxidative indices. The subsequent MD administration caused significant weight reduction without appetite suppression and amelioration of insulin resistance, steatosis and dyslipidemia. Besides, MD significantly reduced lipid hydroperoxides and protein carbonyls in tissue homogenates and urine and elevated Trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP) and reduced glutathione (GSH) and thus, alleviated oxidative stress. The weight reduction was correlated with downregulation of inflammatory markers and the increased UCP-1 level, suggesting weight loss plausibly through thermogenesis. The Akkermansia genus (reflects improved metabolic status) in the HFD50 group was more abundant than that in the HFD group while the non-enzymatic antioxidant markers were strongly associated with UCP-1. In conclusion, MD ameliorates obesity and its related complications possibly via the upregulation of UCP-1 and increased abundance of Akkermansia genus and is promising as a therapeutic agent in the treatment of obesity and its associated metabolic disorders.

The controversial role of glucose in the diabetic kidney

The kidneys play an important role in maintaining glucose homeostasis being the main mechanisms, the gluconeogenesis, renal glucose consumption and glucose reabsorption in the proximal tubules. In this review, we present the main research into the role of glycogen-the stored form of glucose, and how it accumulates in the cells, providing new information on the link between diabetes and diabetic kidney disease. In the last 10 years, research under the scope of renal insulin handling, glucose transport in the proximal tubules, renal gluconeogenesis and renal insulin resistance, made possible to relate the roles of glucose and glycogen in the kidney with other several organs, like the liver. On the one hand, insulin positively regulates kidney uptake and degradation, and there is probably a specific action and resistance to insulin at the renal site. Moreover, insulin regulates the bioavailability of the sodium-glucose co-transporters-SGLT2 inhibitor, and inhibits renal gluconeogenesis. Only the liver and kidneys can supply glucose to the circulation through the process of gluconeogenesis, which involves the synthesis of glucose again from non-glycemic substrates; and the decomposition of stored glycogen. In the mind of nephrologists, diabetologists and scientists, glucose metabolism in the kidney is the focus, with the relevant success of inhibitors in reducing kidney and cardiovascular diseases in individuals with diabetes. However, these new data led to the intriguing paradigm that many of the beneficial effects on the renal and cardiovascular system appear to be independent of the systemic glucose-lowering actions of these agents. The goal of this work puts in context a highly relevant research area for renal glucose metabolism, of glycogen accumulation and metabolism in the diabetic kidney.

Non-hematopoietic IL-4Rα expression contributes to fructose-driven obesity and metabolic sequelae

OBJECTIVE

The risks of excess sugar intake in addition to high-fat diet consumption on immunopathogenesis of obesity-associated metabolic diseases are poorly defined. Interleukin-4 (IL-4) and IL-13 signaling via IL-4Rα regulates adipose tissue lipolysis, insulin sensitivity, and liver fibrosis in obesity. However, the contribution of IL-4Rα to sugar rich diet-driven obesity and metabolic sequelae remains unknown.

METHODS

WT, IL-4Rα-deficient (IL-4Rα^-/-) and STAT6-deficient mice (STAT6^-/-) male mice were fed low-fat chow, high fat (HF) or HF plus high carbohydrate (HC/fructose) diet (HF + HC). Analysis included quantification of: (i) body weight, adiposity, energy expenditure, fructose metabolism, fatty acid oxidation/synthesis, glucose dysmetabolism and hepatocellular damage; (ii) the contribution of the hematopoietic or non-hematopoietic IL-4Rα expression; and (iii) the relevance of IL-4Rα downstream canonical STAT6 signaling pathway in this setting.

RESULTS

We show that IL-4Rα regulated HF + HC diet-driven weight gain, whole body adiposity, adipose tissue inflammatory gene expression, energy expenditure, locomotor activity, glucose metabolism, hepatic steatosis, hepatic inflammatory gene expression and hepatocellular damage. These effects were potentially, and in part, dependent on non-hematopoietic IL-4Rα expression but were independent of direct STAT6 activation. Mechanistically, hepatic ketohexokinase-A and C expression was dependent on IL-4Rα, as it was reduced in IL-4Rα-deficient mice. KHK activity was also affected by HF + HC dietary challenge. Further, reduced expression/activity of KHK in IL-4Rα mice had a significant effect on fatty acid oxidation and fatty acid synthesis pathways.

CONCLUSION

Our findings highlight potential contribution of non-hematopoietic IL-4Rα activation of a non-canonical signaling pathway that regulates the HF + HC diet-driven induction of obesity and severity of obesity-associated sequelae.

The effects of physical activity on adipokines in individuals with overweight/obesity across the lifespan: A narrative review

This narrative review summarizes current knowledge on the effects of physical activity (PA) on adipokine levels in individuals with overweight and obesity. Approximately 90 investigations including randomized control, cross-sectional and longitudinal studies that reported on the effects of a single session of PA (acute) or long-term PA (chronic) on adipokine levels in individuals with overweight/obesity were reviewed. The findings support the notion that there is consensus on the benefits of chronic exercise training-regardless of the mode (resistance vs. aerobic), intensity and cohort (healthy vs. diabetes)-on adipokine levels (such as tumour necrosis factor-alpha, interleukin-6, adiponectin, visfatin, omentin-1 and leptin). However, several confounding factors (frequency, intensity, time and type of exercise) can alter the magnitude of the effects of an acute exercise session. Available evidence suggests that PA, as a part of routine lifestyle behaviour, improves obesity complications by modulating adipokine levels. However, additional research is needed to help identify the most effective interventions to elicit the most beneficial changes in adipokine levels in individuals with overweight/obesity.

Interplay between Thyroid Hormones and Stearoyl-CoA Desaturase 1 in the Regulation of Lipid Metabolism in the Heart

Stearoyl-CoA desaturase 1 (SCD1), an enzyme that is involved in the biosynthesis of monounsaturated fatty acids, induces the reprogramming of cardiomyocyte metabolism. Thyroid hormones (THs) activate both lipolysis and lipogenesis. Many genes that are involved in lipid metabolism, including Scd1, are regulated by THs. The present study used SCD1 knockout (SCD1^−/−) mice to test the hypothesis that THs are important factors that mediate the anti-steatotic effect of SCD1 downregulation in the heart. SCD1 deficiency decreased plasma levels of thyroid-stimulating hormone and thyroxine and the expression of genes that regulate intracellular TH levels (i.e., Slc16a2 and Dio1-3) in cardiomyocytes. Both hypothyroidism and SCD1 deficiency affected genomic and non-genomic TH pathways in the heart. SCD1 deficiency is known to protect mice from genetic- or diet-induced obesity and decrease lipid content in the heart. Interestingly, hypothyroidism increased body adiposity and triglyceride and diacylglycerol levels in the heart in SCD1^−/− mice. The accumulation of triglycerides in cardiomyocytes in SCD1^−/− hypothyroid mice was caused by the activation of lipogenesis, which likely exceeded the upregulation of lipolysis and fatty acid oxidation. Lipid accumulation was also observed in the heart in wildtype hypothyroid mice compared with wildtype control mice, but this process was related to a reduction of triglyceride lipolysis and fatty acid oxidation. We also found that simultaneous SCD1 and deiodinase inhibition increased triglyceride content in HL-1 cardiomyocytes, and this process was related to the downregulation of lipolysis. Altogether, the present results suggest that THs are an important part of the mechanism of SCD1 in cardiac lipid utilization and may be involved in the upregulation of energetic metabolism that is associated with SCD1 deficiency.

Role of Adiponectin and Tumor Necrosis Factor-Alpha in the Pathogenesis and Evolution of Type 1 Diabetes Mellitus in Children and Adolescents

Type 1 diabetes mellitus (T1DM) is a complex condition caused by the destruction of pancreatic beta cells by autoimmune mechanisms. As a result, insulin deficiency and subsequent hyperglycemia occur. The aim of the present study is to investigate the role of adiponectin and tumor necrosis factor alpha (TNF-α) in the development of T1DM. The study is designed as an observational case-control study, involving 52 diabetic patients and 66 controls. Z scores for Body Mass Index (BMI), weight, height, and adiponectin and TNF-α serum levels were assessed in both groups. The T1DM group had significantly higher TNF-α levels and a significantly higher proportion of high-risk patients for inflammation based on TNF-α values as compared to the control group, while both groups had statistically similar adiponectin levels and a similar proportion of high/medium-risk patients based on adiponectin values. TNF-α plays a significant role in the pathogenesis and evolution of T1DM and it may represent an additional marker of disease progression, as well as a potential target of immunotherapeutic strategies. In the present study, no statistically significant differences were recorded in adiponectin levels neither in diabetic patients and controls, nor in high/medium severity risk diabetic patients.

(-)-Epicatechin and the colonic metabolite 2,3-dihydroxybenzoic acid protect against high glucose and lipopolysaccharide-induced inflammation in renal proximal tubular cells through NOX-4/p38 signalling

Chronic hyperglycaemia and inflammation are present in diabetes and both processes have been related to the pathogenesis of diabetic kidney disease. Epicatechin (EC) and main colonic phenolic acids derived from flavonoid intake, such as 2,3-dihydroxybenzoic acid (DHBA), 3,4-dihydroxyphenylacetic acid (DHPAA) and 3-hydroxyphenylpropionic acid (HPPA), have been suggested to exert beneficial effects in diabetes. This study was aimed at investigating whether the mentioned compounds could prevent inflammation in renal proximal tubular NRK-52E cells induced by high glucose and lipopolysaccharide (LPS). Pre-treatment of cells with EC and DHBA (5 μM) reverted the enhanced levels of pro-inflammatory cytokines, such as tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6) and monocyte chemoattractant protein 1 (MCP-1), activated by high glucose and LPS. Additionally, EC and DHBA pre-incubation reduced the increased values of adhesion molecules, namely, intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), as well as those of mitogen-activated protein kinases (MAPKs) [extracellular signal-regulated kinase (ERK), -c-jun N-terminal kinase (JNK) and -p38 protein kinase (p38)] activated by the high glucose and LPS challenge. Thus, in EC and DHBA pre-treated cells ICAM-1, p-ERK and p-JNK were returned to control values, and VCAM-1 and p-p38 levels were reduced by ∼20 and 25%, respectively, when compared to high glucose plus LPS-stimulated cells. Likewise, pre-treatment with EC and DHBA protected against high glucose plus LPS-triggered oxidative stress by preventing increased ROS and NADPH oxidase 4 (NOX-4) levels (∼25 and 45% reduction, respectively). By using specific inhibitors of p38 and NOX-4, the participation of both proteins in EC- and DHBA-mediated protection against inflammation and associated oxidative stress was shown. Taken together, EC and DHBA exert beneficial effects in renal proximal tubular cells, as they contribute to preventing the inflammatory-induced milieu and the accompanying redox imbalance, playing NOX-4/p38 a crucial role.

Angiotensin-converting enzyme 2, the complement system, the kallikrein-kinin system, type-2 diabetes, interleukin-6, and their interactions regarding the complex COVID-19 pathophysiological crossroads

Because of the current COVID-19-pandemic, the world is currently being held hostage in various lockdowns. ACE2 facilitates SARS-CoV-2 cell-entry, and is at the very center of several pathophysiological pathways regarding the RAAS, CS, KKS, T2DM, and IL-6. Their interactions with severe COVID-19 complications (e.g. ARDS and thrombosis), and potential therapeutic targets for pharmacological intervention, will be reviewed.

Glucose Levels as a Mediator of the Detrimental Effect of Abdominal Obesity on Relative Handgrip Strength in Older Adults

Excess central adiposity accelerates the decline of muscle strength in older people. Additionally, hyperglycemia, independent of associated comorbidities, is related to the loss of muscle mass and strength, and contributes to functional impairment in older adults. We studied the mediation effect of glucose levels, in the relationship between abdominal obesity and relative handgrip strength (HGS). A total of 1571 participants (60.0% women, mean age 69.1 ± 7.0 years) from 86 municipalities were selected following a multistage area probability sampling design. Measurements included demographic and anthropometric/adiposity markers (weight, height, body mass index, and waist circumference). HGS was measured using a digital dynamometer for three sets and the mean value was recorded. The values were normalized to body weight (relative HGS). Fasting glucose was analyzed by enzymatic colorimetric methods. Mediation analyses were performed to identify associations between the independent variable (abdominal obesity) and outcomes (relative HGS), as well as to determine whether fasting glucose levels mediated the relationship between excess adiposity and relative HGS. A total of 1239 (78.8%) had abdominal obesity. Abdominal obesity had a negative effect on fasting glucose (β = 9.04, 95%CI = 5.87 to 12.21); while fasting glucose to relative HGS was inversely related (β = −0.003, 95%CI = −0.005 to −0.001), p < 0.001. The direct effect of abdominal obesity on relative HGS was statistically significant (β = −0.069, 95%CI = −0.082 to −0.057), p < 0.001. Lastly, fasting glucose levels mediates the detrimental effect of abdominal obesity on relative HGS (indirect effect β = −0.002, 95%CI = −0.004 to −0.001), p < 0.001. Our results suggest that the glucose level could worsen the association between abdominal obesity status and lower HGS. Thus, it is plausible to consider fasting glucose levels when assessing older adults with excess adiposity and/or suspected loss of muscle mass.

The essential function of IL-33 in metabolic regulation

Interleukin-33 (IL-33) is produced by various types of cells under physical or pathological conditions. As a multifunctional partner in health and disease, current evidence reveals that IL-33 also participates in several metabolic processes. IL-33 has been proven to contribute to regulating the activity of ST2+ group 2 innate lymphoid cells and regulatory T cells in adipose, which leads to the shift of insulin sensitivity and glucose clearance in glucose metabolism, thermogenesis, and adipocyte beiging in adipose metabolism. In this review, we briefly summarize the biological characteristics of Il-33 and discuss its regulatory function in glucose and adipose metabolism. By clarifying the underlying mechanism of IL-33, we highlight the crosstalk between immune response and metabolic processes mediated by IL-33.

Circulating Pro- and Anti-Inflammatory Metabolites and Its Potential Role in Rheumatoid Arthritis Pathogenesis

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease that affects synovial joints, leading to inflammation, joint destruction, loss of function, and disability. Although recent pharmaceutical advances have improved the treatment of RA, patients often inquire about dietary interventions to improve RA symptoms, as they perceive pain and/or swelling after the consumption or avoidance of certain foods. There is evidence that some foods have pro- or anti-inflammatory effects mediated by diet-related metabolites. In addition, recent literature has shown a link between diet-related metabolites and microbiome changes, since the gut microbiome is involved in the metabolism of some dietary ingredients. But diet and the gut microbiome are not the only factors linked to circulating pro- and anti-inflammatory metabolites. Other factors including smoking, associated comorbidities, and therapeutic drugs might also modify the circulating metabolomic profile and play a role in RA pathogenesis. This article summarizes what is known about circulating pro- and anti-inflammatory metabolites in RA. It also emphasizes factors that might be involved in their circulating concentrations and diet-related metabolites with a beneficial effect in RA.

Modulation of immune function in the bovine uterus peripartum

There is a high risk of clinical or subclinical reproductive tract disease in the postpartum period in dairy cows. An integrated process of adaptive events should occur synchronously, including a robust but well-regulated immune response in the uterus. Failure of this process may result in reproductive tract inflammatory disease. Up to half of postpartum dairy cows are affected by metritis, purulent vaginal discharge (PVD), or subclinical endometritis. After parturition there is damage to the birth canal, the superficial layer of the endometrium is naturally wounded, and essentially all dairy cows have bacterial contamination in the uterus. Neutrophils are the most abundant type of inflammatory cell and the main line of defence against infection in the uterus. A prompt influx of neutrophils is associated with uterine health. Avoidance of clinical disease (metritis and PVD) depends in large part on how effective the immune response is at limiting the burden and effects of bacterial pathogens, while the occurrence of subclinical endometritis is more a function of avoiding excessive or persistent inflammation. Glucose supply, hypocalcemia, lipid mobilization from body fat, ketosis, and the flux of pro-inflammatory cytokines influence immune response and change rapidly and variably among individual cows. Effective but well-regulated inflammatory response will be favoured by best management practices for transition cows, but specific interventions to modulate immune response to prevent uterine disease remain developmental.

Serum concentration of asprosin in new-onset type 2 diabetes

BACKGROUND

Asprosin, a newly identified adipokine, is pathologically increased in individuals with insulin resistance. However, the available evidence on the association of asprosin and type 2 diabetes mellitus (T2DM) status is still scarce. Therefore, this study aimed to determine the relationship between serum concentrations of asprosin and T2DM status.

METHODS

This observational study was performed based on 194 adults (97 newly diagnosed T2DM and 97 healthy individuals). Anthropometric and biochemical variables were determined in all participants. Serum concentrations of asprosin were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

In patients with T2DM, the serum concentrations of asprosin were significantly higher than the healthy controls (4.18 [IQR: 4.4] vs. 3.5 [IQR: 1.85], P < 0.001). The concentrations of asprosin were significantly correlated with body mass index (BMI) and fasting blood glucose (FBG) in healthy subjects and with BMI, FBG, hemoglobin A1c (HbA1c), homeostatic model assessment of insulin resistance (HOMA-IR), and quantitative insulin check index (QUICKI), triacylglycerol (TAG) and total cholesterol/high-density lipoprotein cholesterol (TC/HDL-C) ratio in the T2DM group. In fully adjusted model, the odds ratio (OR) of T2DM with serum concentrations of asprosin was approximately 1.547 (95% CI 1.293-1.850, P < 0.001) compared to the control group. Multiple stepwise regression analysis indicated that FBG and HOMA-IR were independently associated with asprosin in T2DM.

CONCLUSION

Our findings indicated that serum concentrations of asprosin are increased in patients with T2DM. Also, asprosin is correlated with insulin resistance and TC/HDL-C ratio (atherosclerotic risk factor of cardiovascular diseases) in patients with T2DM.