Signaling pathways linking inflammation to insulin resistance

Transcriptomic regulatory analysis of skeletal muscle development in landrace pigs

The development of pig skeletal muscle is a complex dynamic regulation process, which mainly includes the formation of primary and secondary muscle fibers, the remodeling of muscle fibers, and the maturation of skeletal muscle; However, the regulatory mechanism of the entire developmental process remains unclear. This study analyzed the whole-transcriptome data of skeletal muscles at 27 developmental nodes (E33-D180) in Landrace pigs, and their key regulatory factors in the development process were identified using the bioinformatics method. Firstly, we constructed a transcriptome expression map of skeletal muscle development from embryo to adulthood in Landrace pig. Subsequently, due to drastic change in gene expression, the perinatal periods including E105, D0 and D9, were focused, and the genes related to the process of muscle fiber remodeling and volume expansion were revealed. Then, though conjoint analysis with miRNA and lncRNA transcripts, a ceRNA network were identified, which consist of 11 key regulatory genes (such as CHAC1, RTN4IP1 and SESN1), 7 miRNAs and 43 lncRNAs, and they potentially play an important role in the process of muscle fiber differentiation, muscle fiber remodeling and volume expansion, intramuscular fat deposition, and other skeletal muscle developmental events. In summary, we reveal candidate genes and underlying molecular regulatory networks associated with perinatal skeletal muscle fiber type remodeling and expansion. These data provide new insights into the molecular regulation of mammalian skeletal muscle development and diversity.

Attenuation of PI3K/AKT signaling pathway by Ocimum gratissimum leaf flavonoid-rich extracts in streptozotocin-induced diabetic male rats

Diabetes is a group of medical conditions characterized by the body's inability to effectively control blood glucose levels, due to either insufficient insulin synthesis in type 1 diabetes or inadequate insulin sensitivity in type 2 diabetes. According to this research, the PI3K/AKT pathway of Ocimum gratissimum leaf flavonoid-rich extracts in streptozotocin-induced diabetic rats was studied. We purchased and used a total of forty (40) male Wistar rats for the study. We divided the animals into five (5) different groups: normal control (Group A), diabetic control (Group B), low dose (150 mg/kg body weight) of Ocimum gratissimum flavonoid-rich leaf extract (LDOGFL) (Group C), high dose (300 mg/kg body weight) of Ocimum gratissimum flavonoid-rich leaf extract (HDOGFL) (Group D), and 200 mg/kg of metformin (MET) (Group E). Streptozotocin induced all groups except Group A, which serves as the normal control group. The experiment lasted for 21 days, following which we sacrificed the animals and harvested their brains for biochemical analysis on the 22nd day. We carried out an analysis that included reduced glutathione (GSH), glutathione transferases (GST), catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD), along with GLUT4, MDA, pro-inflammatory cytokines, NO, neurotransmitters, cholinergic enzyme activities, cardiolipin, and the gene expression of PI3K/AKT. The obtained result indicates that the flavonoid-rich extracts of O. gratissimum significantly enhanced the levels of GSH, GST, CAT, GPx, and SOD, as well as GLUT4 and cardiolipin. The levels of GSH, GST, CAT, GPx, and SOD, as well as GLUT4 and cardiolipin, were significantly increased by gratissimum. Moreover, the extracts decrease the levels of MDA, pro-inflammatory cytokines, NO, neurotransmitters, and cholinergic enzyme activities. Additionally, the flavonoid-rich extracts of O. gratissimum significantly improved the AKT and PI3K gene expressions in diabetic rats. gratissimum had their AKT and PI3K gene expressions significantly (p < 0.05) improved. The findings indicate that O. gratissimum leaf flavonoids have the potential to treat diabetes mellitus. gratissimum leaf flavonoids possess therapeutic potential in themselves and can be applied in the management of diabetes mellitus. Although further analysis can be carried out in terms of isolating, profiling, or purifying the active compounds present in the plant's extract.

TRPV4 in adipose tissue ameliorates diet-induced obesity by promoting white adipocyte browning

The induction of adipocyte browning to increase energy expenditure is a promising strategy to combat obesity. Transient receptor potential channel V4 (TRPV4) functions as a nonselective cation channel in various cells and plays physiological roles in osmotic and thermal sensations. However, the function of TRPV4 in energy metabolism remains controversial. This study revealed the role of TRPV4 in adipose tissue in the development of obesity. Adipose-specific TRPV4 overexpression protected mice against diet-induced obesity (DIO) and promoted white fat browning. TRPV4 overexpression was also associated with decreased adipose inflammation and improved insulin sensitivity. Mechanistically, TRPV4 could directly promote white adipocyte browning via the AKT pathway. Consistently, adipose-specific TRPV4 knockout exacerbated DIO with impaired thermogenesis and activated inflammation. Corroborating our findings in mice, TRPV4 expression was low in the white adipose tissue of obese people. Our results positioned TRPV4 as a potential regulator of obesity and energy expenditure in mice and humans.

Does gut brain axis has an impact on Parkinson's disease (PD)?

Parkinson's Disease (PD) is becoming a growing global concern by being the second most prevalent disease next to Alzheimer's Disease (AD). Henceforth new exploration is needed in search of new aspects towards the disease mechanism and origin. Evidence from recent studies has clearly stated the role of Gut Microbiota (GM) in the maintenance of the brain and as a root cause of various diseases and disorders including other neurological conditions. In the case of PD, with an unknown etiology, the GM is said to have a larger impact on the disease pathophysiology. Although GM and its metabolites are crucial for maintaining the normal physiology of the host, it is an undeniable fact that there is an influence of GM in the pathophysiology of PD. As such the Enteroendocrine Cells (EECs) in the epithelium of the intestine are one of the significant regulators of the gut-brain axis and act as a communication mediator between the gut and the brain. The communication is established via the molecules of neuroendocrine which are said to have a crucial part in neurological diseases such as AD, PD, and other psychiatry-related disorders. This review is focused on understanding the proper role of GM and EECs in PD. Here, we also focus on some of the metabolites and compounds that can interact with the PD genes causing various dysfunctions in the cell and facilitating the disease conditions using bioinformatical tools. Various mechanisms concerning EECs and PD, their identification, the latest studies, and available current therapies have also been discussed.

The impact of fish oil and/or probiotics on serum fatty acids and the interaction with low-grade inflammation in pregnant women with overweight and obesity: secondary analysis of a randomised controlled trial

N-3 long-chain PUFA (LC-PUFA) and probiotics are generally considered to induce health benefits. The objective was to investigate (1) the impact of fish oil and/or probiotics on serum fatty acids (sFA), (2) the interaction of sFA with low-grade inflammation and (3) the relation of sFA to the onset of gestational diabetes mellitus (GDM). Pregnant women with overweight/obesity were allocated into intervention groups with fish oil + placebo, probiotics + placebo, fish oil + probiotics or placebo + placebo in early pregnancy (fish oil: 1·9 g DHA and 0·22 g EPA, probiotics: Lacticaseibacillus rhamnosus HN001 and Bifidobacterium animalis ssp. lactis 420, 1010 CFU, each daily). Blood samples were collected in early (n 431) and late pregnancy (n 361) for analysis of fatty acids in serum phosphatidylcholine (PC), cholesteryl esters (CE), TAG and NEFA with GC and high-sensitivity C-reactive protein and GlycA by immunoassay and NMR spectroscopy, respectively. GDM was diagnosed according to 2 h 75 g oral glucose tolerance test. EPA in PC, CE and TAG and DHA in PC, CE, TAG and NEFA were higher in fish oil and fish oil + probiotics groups compared with placebo. EPA in serum NEFA was lower in women receiving probiotics compared with women not receiving. Low-grade inflammation was inversely associated with n-3 LC-PUFA, which were related to an increased risk of GDM. Fish oil and fish oil + probiotics consumption increase serum n-3 LC-PUFA in pregnant women with overweight/obesity. Although these fatty acids were inversely related to inflammatory markers, n-3 LC-PUFA were linked with an increased risk for GDM.

Specific gut microbiome and metabolome changes in patients with continuous ambulatory peritoneal dialysis and comparison between patients with different dialysis vintages

Background

In recent years, the role of gut microbiota and derived metabolites in renal disease has attracted more attention. It has been established that the gut microbiota is a potential target for medical interventions in renal disease including chronic kidney disease (CKD), acute kidney injury (AKI) and renal calculus. Emerging evidence has related dialysis treatment to the microbial composition and function of the intestines, and there are many reports related to HD, but few studies have been related to PD. Previous studies have found that PD patients have intestinal flora disturbances, so we speculate that intestinal flora and its metabolites may be the regulatory factors in long-term therapy of PD. And as far as we know, there have been no studies characterized the gut microbiota in PD patients of different dialysis vintages.

Methods

It is a cross-sectional study based on clinical data and biological samples of 72 patients with CAPD, 13 patients with ESRD and 13 healthy volunteers. The intestinal microecological characteristics of CAPD patients were comprehensively evaluated by combining the intestinal microflora structure, enterotoxin and receptor (serum LPS and LBP), intestinal barrier function index (serum D-Lactate), intestinal uremic toxin (serum IS, PCS, TMAO), fecal SCFAs and other multi-dimensional and multi-omics studies. Furthermore, the changes of intestinal microecology in CAPD patients of different dialysis vintages (≥ 3 and < 12 months, ≥ 12 and < 24 months, ≥ 24 and < 60 months, ≥ 60 months) were further explored, and the correlations between intestinal microecology indicators and some clinical indicators were analyzed. Fecal and serum samples were collected from PD patients (PD group, n = 72), ESRD patients (ESRD group, n = 13) and healthy volunteers (Normal group, n = 13). Fecal samples were subjected to microbiome (16S rDNA) and SCFA (GC-MS) analyses. Serum samples were subjected to LPS, LBP, D-lactate, IS, PCS, and TMAO (ELISA) analyses.

Results

The diversity and richness of intestinal flora in CAPD patients were lower than those in healthy people and ESRD patients, and the microflora structure was different. Anaerobes of Blautia and facultative anaerobes and aerobic bacteria with Bacilli and Lactobacillales those in Firmicutes are the main intestinal flora in CAPD patients. The abundance of Bacteroidaceae, Bacteroides, Faecalibacterium and other dominant bacteria in the intestinal tract of CAPD patients decreased. Proteobacteria, Enterobacteriaceae and Escherichia-Shigella increased their colonization (LDA > 4). In CAPD patients of different dialysis vintages, there was no significant change in the diversity and richness of microflora, and the microflora structure of PDC group was significantly different from that of PDD, which the abnormal expansion of enterobacter group was more prominent in PDC and the abundance of Bacteroides group was relatively higher in PDD. Intestinal barrier damage, intestinal uremic toxin accumulation and short-chain fatty acid reduction were observed in CAPD patients, such as the serum level of D-Lactate, PCS and TMAO were significantly higher than that in the Normal group (P < 0.05),and the fecal levels of BA and CA were significantly lower (P < 0.05). The intestinal microecological disorder of PDC group, while that of PDD group showed a better trend. Such as the PDC group had a significantly higher serum level of LPS, D-Lactate and TMAO (P < 0.01), and significantly lower serum level of LBP (P < 0.01), and lower fecal levels of AA and BA (P > 0.05) than the PDD group.

Conclusion

The intestinal microecology and metabolic system of CAPD patients had changes compared with healthy people and ESRD non-dialysis patients, and there were differences in CAPD patients with different dialysis vintages. PD patients on dialysis for more than 60 months showed a better trend in the intestinal microecology than patients with 24∼36 months, which suggested that the intestinal microecology of PD patients had a certain ability of self-regulation and remodeling under the management of standardized system and it is necessary to strengthen the monitoring of the intestinal status and the occurrence of related complications in PD patients on dialysis of 24∼36 months of dialysis vintage. It is initially considered that the mechanism of intestinal microecology is a potential target for intervention in the diagnosis and treatment of CAPD and incorporating intestinal microecosystem monitoring into the long-term management of CAPD patients is a new strategy.

Pathological roles of bone marrow adipocyte-derived monocyte chemotactic protein-1 in type 2 diabetic mice

Type 2 diabetes mellitus (T2DM) has become a prevalent public health concern, with beta-cell dysfunction involved in its pathogenesis. Bone marrow adipose tissue (BMAT) increases in both the quantity and area in individuals with T2DM along with heightened monocyte chemotactic protein-1 (MCP-1) secretion. This study aims to investigate the influence and underlying mechanisms of MCP-1 originating from bone marrow adipocytes (BMAs) on systemic glucose homeostasis in T2DM. Initially, a substantial decrease in the proliferation and glucose-stimulated insulin secretion (GSIS) of islet cells was observed. Moreover, a comparative analysis between the control (Ctrl) group and db/db mice revealed significant alterations in the gene expression profiles of whole bone marrow cells, with a noteworthy upregulation of Mcp-1. And the primary enriched pathways included chemokine signaling pathway and AGE-RAGE signaling pathway in diabetic complications. In addition, the level of MCP-1 was distinctly elevated in BMA-derived conditional media (CM), leading to a substantial inhibition of proliferation, GSIS and the protein level of phosphorylated Akt (p-Akt) in Min6 cells. After blocking MCP-1 pathway, we observed a restoration of p-Akt and the proliferation of islet cells, resulting in a marked improvement in disordered glucose homeostasis. In summary, there is an accumulation of BMAs in T2DM, which secrete excessive MCP-1, exacerbating the abnormal accumulation of BMAs in the bone marrow cavity through paracrine signaling. The upregulated MCP-1, in turn, worsens glucose metabolism disorder by inhibiting the proliferation and insulin secretion of islet cells through an endocrine pathway. Inhibiting MCP-1 signaling can partially restore the proliferation and insulin secretion of islet cells, ultimately ameliorating glucose metabolism disorder. It's worth noting that to delve deeper into the impact of MCP-1 derived from BMAs on islet cells and its potential mechanisms, it is imperative to develop genetically engineered mice with conditional Mcp-1 knockout from BMAs.

Association of triglyceride-glucose index and neutrophil-to-lymphocyte ratio with coronary artery disease

OBJECTIVE

The present study aimed to investigate the association of triglyceride-glucose (TyG) index and neutrophil-to-lymphocyte ratio (NLR) with coronary artery disease (CAD), and evaluate the cumulative value of TyG index and NLR in identifying CAD, as well as the severity of CAD.

METHODS

This retrospective study enrolled 2867 patients who underwent coronary angiography (CAG) for the first time between January 2013 and June 2022 in Zhongnan Hospital of Wuhan University. There were 2109 patients with CAD and 758 patients without CAD. The CAD patients were divided into two groups based on the median of Gensini score (mild stenosis CAD group: Gensini score < 26 points; severe stenosis CAD group: Gensini score ≥ 26 points). To further evaluate the cumulative value of TyG index and NLR in identifying CAD and CAD severity, all patients were classified into four groups based on median of TyG index and NLR: (1) the control group: patients with low-TyG and low-NLR; (2) isolated high-NLR group: patients with low-TyG and high- NLR; (3) isolated high- TyG group: patients with high-TyG and low- NLR; (4) high-TyG combined with high-NLR group: patients with high-TyG and high- NLR.

RESULTS

Multivariate logistic regression analysis showed that both the TyG index and NLR were independent risk factors for CAD, and they were also independent risk factors for severe stenosis in CAD (P < 0.05). Compared with the low-TyG and low- NLR group, patients in high-TyG and high- NLR group had a 1.418 times higher odds ratio (OR) of having CAD and a 1.692 times higher OR of having severe stenosis in CAD in the multivariable logistic regression model. It is worth noting that the OR values of the high-TyG and high- NLR group were higher than those of the isolated high-NLR group and the isolated high- TyG group. The ROC analysis showed that the combination of the TyG index and NLR was superior to TyG index or NLR in predicting CAD and CAD severity.

CONCLUSION

Compared to TyG index or NLR, the combination of the TyG index and NLR is beneficial to improve the diagnostic accuracy of CAD and CAD severity.

Site-Specifically Launched Microneedles for the Combined Treatment of Psoriasis-Diabetic Comorbidity

Psoriasis and diabetes are both common comorbidities for each other, where inflammation and insulin resistance act in a vicious cycle, driving the progression of disease through the activation of the NF-κB signaling pathway. Therefore, disrupting the linkage between inflammation and insulin resistance by inhibiting the NF-κB pathway presents a promising therapeutic strategy for addressing psoriasis-diabetic comorbidity. Herein, an open-loop therapy was developed by integrating microneedle-mediated short- and long-range missiles to target psoriasis and diabetes, respectively. The short-range missile (curcumin nanoparticle) could be stationed in the psoriatic skin for topical and prolonged antipsoriasis therapy, while the long-range missile (metformin) is capable of penetrating transdermal barriers to induce a systemic hypoglycemic effect. More attractively, the short- and long-range missiles could join hands to inhibit the NF-κB signaling pathway and diminish inflammation, effectively disrupting the crosstalk between inflammation and insulin resistance. Pharmacodynamic studies showed that this microneedle-mediated combination, possessing dual anti-inflammatory and antihyperglycemic properties, proves to be highly efficacious in alleviating typical symptoms and inflammatory response in both nondiabetic and diabetic mice with imiquimod (IMQ)-induced psoriasis models. Hence, the microneedle-mediated open-loop therapy shows great potential in the management of psoriasis-diabetes comorbidity.

Effects of omega-3 supplementation on glucose and lipid metabolism in patients with gestational diabetes: A meta-analysis of randomized controlled trials

AIM

We assessed whether omega-3 supplementation could improve glucose and lipid metabolism, insulin resistance, and inflammatory factors in individuals with gestational diabetes mellitus (GDM).

METHODS

In this meta-study, we used a random-effects or fixed-effects meta-analysis model to analyze the mean differences (MD) and corresponding 95 % confidence intervals (CI) before and after omega-3 and placebo supplementation, thus evaluating the effects of omega-3 on glucose and lipid metabolism, insulin resistance, and inflammatory factors.

RESULTS

Six randomized controlled trials (331 participants) were included in the meta-analysis. The levels of fasting plasma glucose (FPG) (WMD = -0.25 mmol/L; 95 % CI: -0.38, -0.12), fasting insulin (WMD = -17.13 pmol/L; 95 % CI: -27.95, -6.30), and homeostasis model of assessment-insulin resistance (WMD = -0.51; 95 % CI: -0.89, -0.12) were lower in the omega-3 group compared to their levels in the placebo group. The results of the analysis of lipid metabolism showed that triglycerides (WMD = -0.18 mmol/L; 95 % CI: -0.29, -0.08) and very low-density lipoprotein cholesterol (WMD = -0.1 mmol/L; 95 % CI: -0.16, -0.03) decreased in the omega-3 group, while high-density lipoproteins (WMD = 0.06 mmol/L; 95 % CI: 0.02, 0.10) increased. Compared to the placebo group, inflammatory factor serum C-reactive protein (SMD = -0.68 mmol/L; 95 % CI: -0.96, -0.39) decreased in the omega-3 group.

CONCLUSION

Omega-3 supplementation can decrease the levels of FPG and inflammatory factors, enhance blood lipid metabolism, and reduce insulin resistance in patients with GDM.

7,8-Dihydroxyflavone Attenuates Inflammatory Response and Insulin Resistance Induced by the Paracrine Interaction between Adipocytes and Macrophages

Obesity-induced inflammation and insulin resistance are mediated by macrophage infiltration into adipose tissue. We investigated the effects of 7,8-dihydroxyflavone (7,8-DHF), a flavone found in plants, on the inflammatory response and insulin resistance induced by the interaction between adipocytes and macrophages. Hypertrophied 3T3-L1 adipocytes were cocultured with RAW 264.7 macrophages and treated with 7,8-DHF (3.12, 12.5, and 50 μM). The inflammatory cytokines and free fatty acid (FFA) release were evaluated by assay kits, and signaling pathways were determined by immunoblotting. Coculture of adipocytes and macrophages increased inflammatory mediators, such as nitric oxide (NO), monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) and FFA secretion but suppressed the production of anti-inflammatory adiponectin. 7,8-DHF counteracted the coculture-induced changes (p < 0.001). 7,8-DHF also inhibited c-Jun N-terminal kinase (JNK) activation and blocked nuclear factor kappa B (NF-κB) nuclear translocation in the coculture system (p < 0.01). In addition, adipocytes cocultured with macrophages did not increase glucose uptake and Akt phosphorylation in response to insulin. However, 7,8-DHF treatment recovered the impaired responsiveness to insulin (p < 0.01). These findings show that 7,8-DHF alleviates inflammation and adipocyte dysfunction in the coculture of hypertrophied 3T3-L1 adipocytes and RAW 264.7 macrophages, indicating its potential as a therapeutic agent for obesity-induced insulin resistance.

Kitul, a food plant with antidiabetic-like effects: Reduction of intracellular reactive species in glucose-stimulated RIN-5F pancreatic β-cells and mitigation of pro-inflammatory mediators in activated RAW 264.7 macrophages

Kitul (Caryota urens L.) inflorescences are broadly used for sweet sap production in Asian countries and Kitul food products are known as being suitable for diabetic patients. Considering the strong ability to inhibit α-glucosidase, we hypothesize that kitul antidiabetic properties might also involve the modulation of inflammatory pathways and hyperglycaemia-induced oxidative damage. Hence, the effects of an inflorescence's methanol extract were investigated in glucose-stimulated pancreatic cells (RIN-5F) and LPS-stimulated RAW 264.7 macrophages. The extract reduced the overproduction of intracellular reactive species in pancreatic cells and also NO, L-citrulline and IL-6 levels in LPS-stimulated RAW 264.7 macrophages. Inhibition of 5-lipoxygenase (IC₅₀ = 166.1 µg/mL) through an uncompetitive manner was also recorded upon treatment with C. urens inflorescences extract. The phenolic profile of the inflorescences was characterized by HPLC-DAD, six hydroxycinnamic acids being identified and quantified. Overall, our data provide additional evidence on the pleiotropic mechanisms of Kitul inflorescences as an antidiabetic agent.

The crucial role and mechanism of insulin resistance in metabolic disease

Insulin resistance (IR) plays a crucial role in the development and progression of metabolism-related diseases such as diabetes, hypertension, tumors, and nonalcoholic fatty liver disease, and provides the basis for a common understanding of these chronic diseases. In this study, we provide a systematic review of the causes, mechanisms, and treatments of IR. The pathogenesis of IR depends on genetics, obesity, age, disease, and drug effects. Mechanistically, any factor leading to abnormalities in the insulin signaling pathway leads to the development of IR in the host, including insulin receptor abnormalities, disturbances in the internal environment (regarding inflammation, hypoxia, lipotoxicity, and immunity), metabolic function of the liver and organelles, and other abnormalities. The available therapeutic strategies for IR are mainly exercise and dietary habit improvement, and chemotherapy based on biguanides and glucagon-like peptide-1, and traditional Chinese medicine treatments (e.g., herbs and acupuncture) can also be helpful. Based on the current understanding of IR mechanisms, there are still some vacancies to follow up and consider, and there is also a need to define more precise biomarkers for different chronic diseases and lifestyle interventions, and to explore natural or synthetic drugs targeting IR treatment. This could enable the treatment of patients with multiple combined metabolic diseases, with the aim of treating the disease holistically to reduce healthcare expenditures and to improve the quality of life of patients to some extent.

Identification of Key Genes and Biological Pathways Associated with Skeletal Muscle Maturation and Hypertrophy in Bos taurus, Ovis aries, and Sus scrofa

The aim of the current study was to identify the major genes and pathways involved in the process of hypertrophy and skeletal muscle maturation that is common for Bos taurus, Ovis aries, and Sus scrofa species. Gene expression profiles related to Bos taurus, Ovis aries, and Sus scrofa muscle, with accession numbers GSE44030, GSE23563, and GSE38518, respectively, were downloaded from the GEO database. Differentially expressed genes (DEGs) were screened out using the Limma package of R software. Genes with Fold Change > 2 and an adjusted p-value < 0.05 were identified as significantly different between two treatments in each species. Subsequently, gene ontology and pathway enrichment analyses were performed. Moreover, hub genes were detected by creating a protein−protein interaction network (PPI). The results of the analysis in Bos taurus showed that in the period of 280 dpc−3-months old, a total of 1839 genes showed a significant difference. In Ovis aries, however, during the period of 135dpc−2-months old, a total of 486 genes were significantly different. Additionally, in the 91 dpc−adult period, a total of 2949 genes were significantly different in Sus scrofa. The results of the KEGG pathway enrichment analysis and GO function annotation in each species separately revealed that in Bos taurus, DEGs were mainly enriched through skeletal muscle fiber development and skeletal muscle contraction, and the positive regulation of fibroblast proliferation, positive regulation of skeletal muscle fiber development, PPAR signaling pathway, and HIF-1 signaling pathway. In Ovis aries, DEGs were mainly enriched through regulating cell growth, skeletal muscle fiber development, the positive regulation of fibroblast proliferation, skeletal muscle cell differentiation, and the PI3K-Akt signaling, HIF-1 signaling, and Rap1 signaling pathways. In Sus scrofa, DEGs were mainly enriched through regulating striated muscle tissue development, the negative regulation of fibroblast proliferation and myoblast differentiation, and the HIF-1 signaling, AMPK signaling, and PI3K-Akt signaling pathways. Using a Venn diagram, 36 common DEGs were identified between Bos taurus, Ovis aries, and Sus scrofa. A biological pathways analysis of 36 common DEGs in Bos taurus, Ovis aries, and Sus scrofa allowed for the identification of common pathways/biological processes, such as myoblast differentiation, the regulation of muscle cell differentiation, and positive regulation of skeletal muscle fiber development, that orchestrated the development and maturation of skeletal muscle. As a result, hub genes were identified, including PPARGC1A, MYOD1, EPAS1, IGF2, CXCR4, and APOA1, in all examined species. This study provided a better understanding of the relationships between genes and their biological pathways in the skeletal muscle maturation process.

Obsessive-compulsive disorder, insulin signaling and diabetes - A novel form of physical health comorbidity: The sweet compulsive brain

BACKGROUND

While a growing body of research highlights a bi-directional link between diabetes and mood disorders, little is known about the relationship between diabetes and obsessive-compulsive disorder (OCD). The aim of the present review is to investigate current evidence linking OCD, insulin-signaling and diabetes.

METHODS

A PubMed search was conducted to review all the available studies assessing diabetes, glucose metabolism and insulin-signaling in OCD patients and vice versa.

RESULTS

Some clinical and epidemiological studies show a higher prevalence of diabetes in OCD and vice versa compared to the general population. Animal and genetic studies suggest a possible role of insulin-signaling in the pathophysiology of OCD. Deep brain stimulation (DBS) studies suggest that abnormal dopaminergic transmission in the striatum may contribute to impaired insulin sensitivity in OCD. While DBS seems to increase insulin sensitivity, a possible protective role of serotonin reuptake-inhibitors on diabetic risk needs further studies.

CONCLUSION

Despite their preliminary nature, these data highlight the importance of further investigations aimed at assessing metabolic features in OCD patients and OCD symptoms in diabetes patients to understand the impact of each condition on the pathophysiology and course of the other. Understanding the role of insulin in the obsessive-compulsive brain could open new treatment pathways for OCD.

Age-Related Hearing Loss: The Link between Inflammaging, Immunosenescence, and Gut Dysbiosis

This article provides a theoretical overview of the association between age-related hearing loss (ARHL), immune system ageing (immunosenescence), and chronic inflammation. ARHL, or presbyacusis, is the most common sensory disability that significantly reduces the quality of life and has a high economic impact. This disorder is linked to genetic risk factors but is also influenced by a lifelong cumulative effect of environmental stressors, such as noise, otological diseases, or ototoxic drugs. Age-related hearing loss and other age-related disorders share common mechanisms which often converge on low-grade chronic inflammation known as “inflammaging”. Various stimuli can sustain inflammaging, including pathogens, cell debris, nutrients, and gut microbiota. As a result of ageing, the immune system can become defective, leading to the accumulation of unresolved inflammatory processes in the body. Gut microbiota plays a central role in inflammaging because it can release inflammatory mediators and crosstalk with other organ systems. A proinflammatory gut environment associated with ageing could result in a leaky gut and the translocation of bacterial metabolites and inflammatory mediators to distant organs via the systemic circulation. Here, we postulate that inflammaging, as a result of immunosenescence and gut dysbiosis, accelerates age-related cochlear degeneration, contributing to the development of ARHL. Age-dependent gut dysbiosis was included as a hypothetical link that should receive more attention in future studies.

A Potential Interplay between HDLs and Adiponectin in Promoting Endothelial Dysfunction in Obesity

Obesity is an epidemic public health problem that has progressively worsened in recent decades and is associated with low-grade chronic inflammation (LGCI) in metabolic tissues and an increased risk of several diseases. In particular, LGCI alters metabolism and increases cardiovascular risk by impairing endothelial function and altering the functions of adiponectin and high-density lipoproteins (HDLs). Adiponectin is an adipokine involved in regulating energy metabolism and body composition. Serum adiponectin levels are reduced in obese individuals and negatively correlate with chronic sub-clinical inflammatory markers. HDLs are a heterogeneous and complex class of lipoproteins that can be dysfunctional in obesity. Adiponectin and HDLs are strictly interdependent, and the maintenance of their interplay is essential for vascular function. Since such a complex network of interactions is still overlooked in clinical settings, this review aims to highlight the mechanisms involved in the impairment of the HDLs/adiponectin axis in obese patients to predict the risk of cardiovascular diseases and activate preventive countermeasures. Here, we provide a narrative review of the role of LGCI in altering HDLs, adiponectin and endothelial functions in obesity to encourage new studies about their synergic effects on cardiovascular health and disease.

Metabolites of Gut Microbiota and Possible Implication in Development of Diabetes Mellitus

Diabetes mellitus is characterized by having a disorder of glucose metabolism. The types of diabetes mellitus include type 1 diabetes mellitus, type 2 diabetes mellitus, gestational diabetes mellitus, and other specific types of diabetes mellitus. Many risk factors contribute to diabetes mellitus mainly including genetics, environment, obesity, and diet. In the recent years, gut microbiota has been shown to be linked to the development of diabetes. It has been reported that the gut microbiota composition of diabetic patients is different from that of healthy people. Although the mechanism behind the abnormality remains to be explored, most hypotheses focus on the inflammation response and leaky gut in relation to the changes in production of endotoxins and metabolites derived from the intestinal flora. Consequently, the above-mentioned abnormalities trigger a series of metabolic changes, gradually leading to development of hyperglycemia, insulin resistance, and diabetes. This review is (i) to summarize the differences in gut microbiota between diabetic patients and healthy people, (ii) to discuss the underlying mechanism(s) by which how lipopolysaccharide, diet, and metabolites of the gut microbiota affect diabetes, and (iii) to provide a new insight in the prevention and treatment of diabetes.

Early metabolic impairment as a contributor to neurodegenerative disease: Mechanisms and potential pharmacological intervention

The metabolic syndrome comprises a family of clinical and laboratory findings, including insulin resistance, hyperglycemia, hypertriglyceridemia, low high-density lipoprotein cholesterol levels, and hypertension, in addition to central obesity. The syndrome confers a high risk of cardiovascular mortality. Indeed, metabolic dysfunction has been shown to cause a direct insult to smooth muscle and endothelial components of the vasculature, which leads to vascular dysfunction and hyperreactivity. This, in turn, causes cerebral vasoconstriction and hypoperfusion, eventually contributing to cognitive deficits. Moreover, the metabolic syndrome disrupts key homeostatic processes in the brain, including apoptosis, autophagy, and neurogenesis. Impairment of such processes in the context of metabolic dysfunction has been implicated in the pathogenesis of neurodegenerative diseases, including Alzheimer, Parkinson, and Huntington diseases. The aim of this review is to elucidate the role that the metabolic syndrome plays in the pathogenesis of the latter disorders, with a focus on the role of perivascular adipose inflammation in the peripheral-to-central transduction of the inflammatory insult. This review delineates common signaling pathways that contribute to these pathologies. Moreover, the role of therapeutic agents aimed at treating the metabolic syndrome, as well as their risk factors that interfere with the aforementioned pathways, are discussed as potential interventions for neurodegenerative diseases.

The roles of catechins in regulation of systemic inflammation

Catechins are a phytochemical present in plants such as tea leaves, beans, black grapes, cherries, and cacao, and have various physiological activities. It is reported that catechins have a health improvement effect and ameliorating effect against various diseases. In addition, antioxidant activity, liver damage prevention, cholesterol lowering effect, and anti-obesity activity were confirmed through in vivo animal and clinical studies. Although most diseases are reported as ones mediating various inflammations, the mechanism for improving inflammation remains unclear. Therefore, the current review article evaluates the physiological activity and various pharmacological actions of catechins and conclude by confirming an improvement effect on the inflammatory response.

Lean insulin-resistant young adults display increased cardiometabolic risk: A retrospective cross-sectional study

AIM

We investigated whether lean insulin-resistant individuals manifest increased cardiometabolic risk.

METHODS

2,341 (51.8% females) healthy 16-23-year-old subjects were categorized as lean or overweight/obese; and insulin-sensitive or insulin-resistant, and compared.

RESULTS

In both sexes, lean insulin-sensitive and insulin-resistant subjects displayed similar measures of obesity (e.g., males, waist-to-height ratio: lean insulin-sensitive: 0.42 ± 0.03, lean insulin-resistant: 0.43 ± 0.03, overweight/obese insulin-sensitive: 0.49 ± 0.05, overweight/obese insulin-resistant: 0.53 ± 0.06). Lean insulin-sensitive individuals were more insulin-sensitive compared with their overweight/obese peers; insulin-resistant groups presented similar insulin-sensitivity (males, the Quantitative insulin-sensitivity check index (QUICKI): lean insulin-sensitive: 0.354 ± 0.022, lean insulin-resistant: 0.304 ± 0.013, overweight/obese insulin-sensitive: 0.343 ± 0.019, overweight/obese insulin-resistant: 0.299 ± 0.015). The two-factor analysis of variance indicated an independent effect of insulin sensitivity, overweight/obesity, and their interaction on the continuous metabolic syndrome score (p < 0.001, all; males, lean insulin-sensitive: 1.87 ± 0.35, lean insulin-resistant: 2.14 ± 0.42, overweight/obese insulin-sensitive: 2.15 ± 0.40, overweight/obese insulin-resistant: 2.75 ± 0.69). C-reactive protein, leukocyte count, and glomerular filtration rate in both sexes; uric acid, asymmetric dimethyl-arginine, and soluble vascular adhesion protein-1 in males; and soluble receptor for advanced glycation end-products in females were independently associated with insulin resistance. Among phenotypes associated with low QUICKI, the distribution of insulin-resistant individuals was random.

CONCLUSION

Later clinical consequences of insulin resistance in lean subjects remain to be elucidated in longitudinal studies.

Black Truffle Extract Exerts Antidiabetic Effects through Inhibition of Inflammation and Lipid Metabolism Regulation

Black truffle, a culinary and medical fungus, is highly valued worldwide for its nutritional and therapeutic importance. To enhance the existing knowledge about the beneficial properties, this study investigates the antioxidant, antihyperlipidemic, and anti-inflammatory effects of black truffle extract in in vitro biochemical assays and animal study. Briefly, black truffle extract was administered orally to treat streptozotocin- (STZ-) induced diabetic Wistar rats for 45 days. At the end of the experimental duration, rats were sacrificed to perform biochemical and gene expression analyses related to lipid regulatory and inflammatory pathways. Our results indicated that total cholesterol, triglycerides, free fatty acids, phospholipids, and low-density lipoprotein in different tissues and circulation were significantly increased in diabetic rats. Furthermore, the β-hydroxy β-methylglutaryl-CoA enzyme was also significantly increased; lipoprotein lipase and lecithin-cholesterol acyltransferase enzymes were significantly decreased in diabetic rats. However, the above conditions were reversed upon black truffle extract feeding. Furthermore, black truffle extract was also found to downregulate the expression of proinflammatory cytokines (tumor necrosis factor-α and interleukin-6) and lipid regulatory genes (serum regulatory element-binding protein-1 and fatty acid synthase). The truffle extract-treated effects were comparable to glibenclamide and medication commonly used to treat diabetes mellitus. Overall, our results suggested that black truffle possesses strong antihyperlipidemic and anti-inflammatory effects on diabetic rats. These findings will enhance the current knowledge about the therapeutic importance of black truffles. They might be exploited as a possible food supplement or even as a natural source of pharmaceutical agents for diabetes prevention and treatment.

Clinical investigation of lipopolysaccharide in the persistence of metabolic syndrome (MS) through the activation of GRP78-IRE1α-ASK1 signaling pathway

OBJECTIVE

Endoplasmic reticulum stress (ERS) might play a pivotal role in the persistence of metabolic syndrome (MS). Lipopolysaccharide (LPS) derived from various gram-negative bacteria could result in the ERS. Therefore, we aimed to investigate the association between LPS and ERS in MS.

METHOD

We enrolled 86 patients with MS and 42 healthy people aged 35-65 years. Body weight, waist circumference, blood pressure were measured. LPS, LBP and inflammation factors, fasting plasma glucose (FPG), insulin, total cholesterol (TC), triglyceride, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), free fatty acid (FFA) were analyzed in blood plasma of patient's cohort. Body mass index (BMI) and HOMA-IR were calculated. The mRNA and protein expression of ERS GRP78, IRE1α, ASK1 and IKKβ, JNK1 were measured in blood plasma of patient's cohort by RT-PCR and Elisa. MS was defined by the updated National Cholesterol Education Program Adult Treatment Panel III criterion for Asian Americans.

RESULTS

BMI, waist circumference, blood pressure, FPG, insulin, HOMA-IR, TC, triglyceride, HDL-C, LDL-C, FFA and LPS, LBP, TNF-α, CRP, IL-1, IL-6, MCP-1 were significantly higher in patients with MS than healthy people (P < 0.001). The correlation analysis suggested that LPS were associated with TNF-α, IL-1, IL-6, MCP-1, LBP, FFA, HOMA-IR potently (P < 0.05). The marker gene and protein expressions of ERS (GRP78, IRE1α, ASK1, IKKβ and JNK) were significantly overexpressed in patients with MS and were positive correlation with LPS (P < 0.05).

CONCLUSION

LPS may play an important role in mediating chronic low-grade inflammation by activating the ERS GRP78-IRE1α-ASK1 signaling pathway, contributing to the persistence of MS.

Comparative Phosphoproteomics of Neuro-2a Cells under Insulin Resistance Reveals New Molecular Signatures of Alzheimer's Disease

Insulin in the brain is a well-known critical factor in neuro-development and regulation of adult neurogenesis in the hippocampus. The abnormality of brain insulin signaling is associated with the aging process and altered brain plasticity, and could promote neurodegeneration in the late stage of Alzheimer’s disease (AD). The precise molecular mechanism of the relationship between insulin resistance and AD remains unclear. The development of phosphoproteomics has advanced our knowledge of phosphorylation-mediated signaling networks and could elucidate the molecular mechanisms of certain pathological conditions. Here, we applied a reliable phosphoproteomic approach to Neuro2a (N2a) cells to identify their molecular features under two different insulin-resistant conditions with clinical relevance: inflammation and dyslipidemia. Despite significant difference in overall phosphoproteome profiles, we found molecular signatures and biological pathways in common between two insulin-resistant conditions. These include the integrin and adenosine monophosphate-activated protein kinase pathways, and we further verified these molecular targets by subsequent biochemical analysis. Among them, the phosphorylation levels of acetyl-CoA carboxylase and Src were reduced in the brain from rodent AD model 5xFAD mice. This study provides new molecular signatures for insulin resistance in N2a cells and possible links between the molecular features of insulin resistance and AD.

Insight into Shenqi Jiangtang Granule on the improved insulin sensitivity by integrating in silico and in vivo approaches

ETHNOPHARMACOLOGICAL RELEVANCE

Presently, insulin resistance has been a growing concern that urgently needs to be addressed, because it not only places patients at risk of developing type 2 diabetes mellitus but also results in metabolic syndrome and different aspects of cardiovascular diseases. Shenqi Jiangtang Granule (SJG) is a classic traditional Chinese medicine (TCM) prescription that is widely used to treat diabetes mellitus and its complications in clinical practice. While studies have revealed that SJG with multi-ingredients and multi-targets characteristics possesses potential anti-insulin resistance pharmacological properties, its mechanisms of action and molecular targets for the treatment of insulin resistance are still obscure, which prompt us to conduct an in-depth research.

AIM OF THE STUDY

This study was purposed to uncover the pharmacological mechanism of SJG against insulin resistance through integrating network pharmacology and experimental validation.

MATERIALS AND METHODS

The putative ingredients of SJG and its related targets were discerned from the TCMSP database. Subsequently, insulin resistance-associated targets were retrieved from GeneCard, OMIM, and GEO database. Compound-target, protein-protein interaction (PPI), and compound-target-pathway networks were established using Cytoscape software. GO and KEGG pathway analyses were performed to identify possible enrichment of genes with specific biological themes. Molecular docking was used to verify the correlation between the main active ingredients and hub targets. Optimal docking conformation was further analyzed by molecular dynamics (MD) simulation. Finally, the potential molecular mechanisms of SJG acting on insulin resistance, as predicted by the network pharmacology analyses, were validated experimentally in insulin-resistant rat model.

RESULTS

136 active compounds, 211 corresponding targets in addition to 1463 disease-related targets were collected, of which 94 intersection targets were obtained. 29 key targets including AKT1, VEGFA, IL-6, CASP3, and PTGS2 were identified through PPI network analysis. Hub module of PPI network was closely associated with inflammation. GO and KEGG analyses also revealed that inflammation-related pathways may be a central factor for SJG to modulate insulin resistance. Molecular docking test showed a good binding potency between primary active ingredients and core targets, and the binding mode of optimal docking conformation was stable in MD simulation. A rat model of insulin resistance was successfully induced by chronic high-fat diet (HFD) consumption. Through a series of in vivo studies, including HEC, ITT, and HOMA-IR measurement, it was revealed that SJG exhibited a beneficial effect on ameliorating insulin resistance, as demonstrated by a significant increase of GIR and a significant decrease of AUCITT and HOMA-IR index value. Further molecular biological analysis showed that SJG can decrease the mRNA expression level and serum concentration of inflammatory cytokines (TNF-α, IL-6, and IL-1β), along with suppressing the p-NFκB protein overexpression, indicating its anti-inflammatory activity. Also, it can contribute to the reversal of the impaired hepatic insulin signaling pathway, as evidenced by up-regulated protein expression of p-Akt and GLUT2.

CONCLUSIONS

Through in silico and in vivo approaches, the present study not only provides a unique insight into the possible mechanism of SJG in insulin resistance after successfully filtering out associated key target genes and signaling pathways, but also suggests a novel promising therapeutic strategy for curing insulin resistance.

Exercise training modulates adipokines dysregulations in metabolic syndrome

Metabolic syndrome (MetS) is a cluster of risk factors for various metabolic diseases, and it is characterized by central obesity, dyslipidemia, hypertension, and insulin resistance. The core component for MetS is adipose tissue, which releases adipokines and influences physical health. Adipokines consist of pro and anti-inflammatory cytokines and contribute to various physiological functions. Generally, a sedentary lifestyle promotes fat accumulation and secretion of pro-inflammatory adipokines. However, regular exercise has been known to exert various beneficial effects on metabolic and cognitive disorders. Although the mechanisms underlying exercise beneficial effects in MetS are not fully understood, changes in energy expenditure, fat accumulation, circulatory level of myokines, and adipokines might be involved. This review article focuses on some of the selected adipokines in MetS, and their responses to exercise training considering possible mechanisms.

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Adipokines are a potential link between visceral fats and complications of MetS.

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Physical inactivity increases pro-inflammatory adipokines.

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Moderate aerobic exercise increases anti-inflammatory adipokines partly via reducing adipose tissue mass.

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Physical exercise-induced myokines might mediate beneficial effects via a cross-talk with adipose tissues.

Pharmacological Actions, Molecular Mechanisms, Pharmacokinetic Progressions, and Clinical Applications of Hydroxysafflor Yellow A in Antidiabetic Research

Hydroxysafflor yellow A (HSYA), a nutraceutical compound derived from safflower (Carthamus tinctorius), has been shown as an effective therapeutic agent in cardiovascular diseases, cancer, and diabetes. Our previous study showed that the effect of HSYA on high-glucose-induced podocyte injury is related to its anti-inflammatory activities via macrophage polarization. Based on the information provided on PubMed, Scopus and Wanfang database, we currently aim to provide an updated overview of the role of HSYA in antidiabetic research from the following points: pharmacological actions, molecular mechanisms, pharmacokinetic progressions, and clinical applications. The pharmacokinetic research of HSYA has laid foundations for the clinical applications of HSYA injection in diabetic nephropathy, diabetic retinopathy, and diabetic neuropathy. The application of HSYA as an antidiabetic oral medicament has been investigated based on its recent oral delivery system research. In vivo and in vitro pharmacological research indicated that the antidiabetic activities of HSYA were based mainly on its antioxidant and anti-inflammatory mechanisms via JNK/c-jun pathway, NOX4 pathway, and macrophage differentiation. Further anti-inflammatory exploration related to NF-κB signaling, MAPK pathway, and PI3K/Akt/mTOR pathway might deserve attention in the future. The anti-inflammatory activities of HSYA related to diabetes and diabetic complications will be a highlight in our following research.

Diabetes mellitus contribution to the remodeling of the tumor microenvironment in gastric cancer

Compelling pieces of evidence derived from both clinical and experimental research has demonstrated the crucial contribution of diabetes mellitus (DM) as a risk factor associated with increased cancer incidence and mortality in many human neoplasms, including gastric cancer (GC). DM is considered a systemic inflammatory disease and therefore, this inflammatory status may have profound effects on the tumor microenvironment (TME), particularly by driving many molecular mechanisms to generate a more aggressive TME. DM is an active driver in the modification of the behavior of many cell components of the TME as well as altering the mechanical properties of the extracellular matrix (ECM), leading to an increased ECM stiffening. Additionally, DM can alter many cellular signaling mechanisms and thus favoring tumor growth, invasion, and metastatic potential, as well as key elements in regulating cellular functions and cross-talks, such as the microRNAs network, the production, and cargo of exosomes, the metabolism of cell stroma and resistance to hypoxia. In the present review, we intend to highlight the mechanistic contributions of DM to the remodeling of TME in GC.

Morus alba L. (Sangzhi) alkaloids (SZ-A) exert anti-inflammatory effects via regulation of MAPK signaling in macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Morus alba L. (Sangzhi) alkaloids (SZ-A) tablets have been approved by the China National Medical Products Administration for T2DM treatment. Our previous study (Liu et al., 2021) revealed that SZ-A protected against diabetes and inflammation in KKAy mice. However, the mechanism and components in SZ-A exerting anti-inflammatory effects are unclear.

AIM OF THE STUDY

Investigate the effects and molecular mechanisms of SZ-A on inflammation, and identify anti-inflammatory active components in SZ-A.

MATERIALS AND METHODS

The major ingredients in SZ-A were analyzed by HPLC and sulfuric acid - anthrone spectrophotometry. The inhibitory activities of SZ-A on lipopolysaccharide (LPS)-stimulated inflammation were determined in bone marrow-derived macrophage (BMDM) and RAW264.7 cells. The cytokine levels of IL-6 and TNF-α in cell culture supernatant were measured by enzyme-linked immunosorbent assay (ELISA). Gene expression levels of IL-6 and TNF-α were detected by qRT-PCR. The levels of protein phosphorylation of p38 MAPK, ERK, and JNK were analyzed by Western blot.

RESULTS

The main components in SZ-A were found to be 1-deoxynojirimycin (DNJ), 1,4-dideoxy-1,4-imino-D-arabinitol (DAB), fagomine (FAG), polysaccharide (APS), and arginine (ARG). SZ-A reduced the levels of IL-6 and TNF-α secreted by LPS-induced RAW264.7 and BMDM cells. Simultaneously, the mRNA expression levels of IL-6 and TNF-α were all significantly suppressed by SZ-A in a concentration-dependent manner. Furthermore, SZ-A inhibited the phosphorylation of p38 MAPK, ERK, and JNK in BMDM and the activation of ERK and JNK signaling in RAW264.7 cells. We also observed that DNJ, DAB, FAG, and ARG markedly downregulated IL-6 and TNF-α cytokine levels, while APS did not have an obvious effect.

CONCLUSIONS

SZ-A attenuates inflammation at least partly by blocking the activation of p38 MAPK, ERK, and JNK signaling pathways. DNJ, FAG, DAB, and ARG are the main constituents in SZ-A that exert anti-inflammatory effects.

JNK downregulation improves olanzapine-induced insulin resistance by suppressing IRS1Ser307 phosphorylation and reducing inflammation

AIMS

c-jun N-terminal kinase (JNK) plays pivotal roles in many physiological processes, including inflammation and glucose metabolism. However, the effects of JNK on olanzapine-induced insulin resistance and the underlying mechanisms have not been fully elucidated. The aim of our study was to explore the role of JNK in olanzapine-induced insulin resistance and the underlying mechanisms.

METHODS

We studied glucose metabolism in olanzapine-treated female C57B/J mice and mice with adeno-associated virus (AAV)-mediated downregulation of JNK1 in epididymal white adipose tissue (eWAT). 3T3-L1 adipocytes were used to investigate the mechanism of JNK1 regulating insulin signaling after olanzapine treatment.

RESULTS

JNK was activated in eWAT after olanzapine treatment. JNK1 downregulation in eWAT ameliorated the insulin resistance and adipose tissue inflammation in olanzapine-treated mice. Furthermore, overexpression of JNK1 in adipocytes exacerbated the glucose disorder while JNK1 knockdown alleviated the impaired insulin signaling on olanzapine challenge, which was likely mediated by the reduced inflammation and insulin receptor substrate 1 (IRS1) phosphorylation. Moreover, the effect of JNK1 was attenuated by downregulation of IRS1 in adipocytes. Finally, the JNK1-IRS1 interaction and IRS1^S307 phosphorylation were required for JNK1-regulated olanzapine-induced insulin resistance in adipocytes.

CONCLUSIONS

Our results demonstrated that JNK1 activation by olanzapine induced insulin resistance by promoting IRS1^Ser307 phosphorylation and inflammation in eWAT. These results highlighted the importance of JNK1 in eWAT as a promising drug target for olanzapine-induced insulin resistance.

Evaluation of the Dose-Dependent Effects of Fermented Mixed Grain Enzyme Food on Adiposity and Its Metabolic Disorders in High-Fat Diet-Induced Obese Mice

Ancient traditions showed that fermented enzyme foods have beneficial health effects on the body. However, only a few studies have reported on its impact on weight loss and metabolic syndrome. Therefore, it is necessary to verify whether diet supplementation with fermented enzyme foods can have a beneficial functional impact on the body. We examined the antiobesity properties of fermented mixed grain (FMG) with digestive enzymes (FMG) in diet-induced obese mice. Sixty C57BL/6J mice were randomly assigned to six dietary groups: (1) normal diet (ND), (2) high-fat diet (HFD), (3) Bacilus Coagulans, (4) steamed grain, (5) low-dose FMG (L-FMG), and (6) high-dose FMG (H-FMG) supplement for 12 weeks. The results showed that H-FMG supplement dramatically decreased body weight and fat mass with simultaneous decreases in plasma lipid contents. Furthermore, H-FMG significantly lowered fasting blood glucose concentrations and improved glucose tolerance compared with the HFD group. Also, the concentrations of inflammatory cytokines secreted from adipocytes in H-FMG-supplemented mice decreased dramatically. Taken together, our findings indicated that H-FMG can ameliorate HFD-induced obesity and its associated complications and could be used as a potential preventive intervention for obesity.

Insulin Signal Transduction Perturbations in Insulin Resistance

Type 2 diabetes mellitus is a widespread medical condition, characterized by high blood glucose and inadequate insulin action, which leads to insulin resistance. Insulin resistance in insulin-responsive tissues precedes the onset of pancreatic β-cell dysfunction. Multiple molecular and pathophysiological mechanisms are involved in insulin resistance. Insulin resistance is a consequence of a complex combination of metabolic disorders, lipotoxicity, glucotoxicity, and inflammation. There is ample evidence linking different mechanistic approaches as the cause of insulin resistance, but no central mechanism is yet described as an underlying reason behind this condition. This review combines and interlinks the defects in the insulin signal transduction pathway of the insulin resistance state with special emphasis on the AGE-RAGE-NF-κB axis. Here, we describe important factors that play a crucial role in the pathogenesis of insulin resistance to provide directionality for the events. The interplay of inflammation and oxidative stress that leads to β-cell decline through the IAPP-RAGE induced β-cell toxicity is also addressed. Overall, by generating a comprehensive overview of the plethora of mechanisms involved in insulin resistance, we focus on the establishment of unifying mechanisms to provide new insights for the future interventions of type 2 diabetes mellitus.

Anthocyanins from the fruits of Lycium ruthenicum Murray improve high-fat diet-induced insulin resistance by ameliorating inflammation and oxidative stress in mice

A high-fat diet (HFD) promotes tissue inflammation, oxidative stress and insulin resistance (IR), thereby contributing to the development of obesity and diabetes. Anthocyanins from Lycium ruthenicum (AC) have demonstrated anti-obesity effects and modulated IR. To investigate the mechanism by which AC attenuates the adverse effects of consuming a HFD, C57BL/6J mice were fed a HFD supplemented with AC or a control diet without AC for 12 weeks. AC supplementation decreased the amount of weight gain, hepatic lipid, and sequentially improved dyslipidemia, inflammation, oxidative stress, and IR in HFD-fed mice. Molecular data revealed that AC inhibited hepatic inflammation by reducing TLR4/NF-κB/JNK in the liver tissues and ameliorated oxidative stress by activating the Nrf2/HO-1/NQO1 pathway. Thus, AC might activate IRS-1/AKT and prevent HFD-induced gluconeogenesis and IR by ameliorating inflammation and oxidative stress. Modulation of inflammation and oxidative stress with AC may represent a promising target for the treatment of IR and provide insight into the mechanism by which AC protects against obesity.

The effects of flaxseed supplementation on metabolic syndrome parameters, insulin resistance and inflammation in ulcerative colitis patients: An open-labeled randomized controlled trial

The present study aimed to evaluate the efficacy of flaxseed supplementation in the management of metabolic syndrome (MetS)-related parameters among the patients with mild-to-moderate ulcerative colitis (UC). A randomized controlled clinical trial was conducted on 70 patients with UC. Participants were randomized in the intervention group, which received 30 g/day ground flaxseed powder or control group. Anthropometric and biochemical variables were assessed at the beginning and end of 12 weeks of intervention. Of the 70 patients enrolled in this study, 64 subjects were included in the final analysis. From baseline to 12 weeks' intervention, flaxseed supplementation resulted in a significant reduction in the serum concentration of insulin (p < .001), HOMA-IR (p < .001), triglyceride (p = .001), total cholesterol (p < .001), and significant increase in the serum levels of HDL (p = .008). Also, we found a significant improvement in the SCCAI score (p < .001), TNF-α (p = .03), and CRP (p < .001) following the flaxseed supplementation. However, we not observed any significant differences between two groups regarding the body weight, BMI, waist circumferences, systolic, and diastolic blood pressure (p > .05). Overall, 12 weeks of flaxseed supplementation resulted in greater improvement in the some MetS-related parameters.

Structural characterization and anti-inflammatory activity of a polysaccharide from the lignified okra

The polysaccharide (AP1-b) of molecular weight 6.59 × 10⁵ Da was isolated from lignified okra (Abelmoschus esculentus (L.) Moench) by hot-water extraction, 40 % ethanol precipitation and purified by DEAE Cellulose chromatography, respectively. The structure and anti-inflammatory activity of AP1-b were investigated. AP1-b was composed of galactose, rhamnose, gluctose, arabinose and galacturonic acid in a molar ratio of 1.98:1.00:0.15:0.32:0.29. The structural features showed that the AP1-b consisted of →2)-α-d-Rhap-(1→, →4)-β-d-Galp-(1→, →4)-α-d-GalpA-(1→, →6)-β-d-Galp-(1→, β-d-Glcp-(1→ and α-l-Araf-(1→. AP1-b could observably improve the inflammatory injury of LPS-induced RAW 264.7 cells by inhibiting the secretion of NO and decreasing the levels of pro-inflammatory factors (IL-1β, iNOS and TNF-α). AP1-b also inhibited the phosphorylation levels of IκB and p65 proteins, manifesting the anti-inflammatory activity of AP1-b may associated with inhibition of NF-κB signaling pathway. Therefore, AP1-b had potential value in treating inflammatory injury.

Celastrol in metabolic diseases: Progress and application prospects

Metabolic diseases are becoming increasingly common in modern society. Therefore, it is essential to develop effective drugs or new treatments for metabolic diseases. As an active ingredient derived from plants, celastrol has shown great potential in the treatment of a wide variety of metabolic diseases and received considerable attention in recent years. In reported studies, the anti-obesity effect of celastrol resulted from regulating leptin sensitivity, energy metabolism, inflammation, lipid metabolism and even gut microbiota. Celastrol reversed insulin resistance via multiple routes to protect against type 2 diabetes. Celastrol also showed effects on atherosclerosis, cholestasis and osteoporosis. Celastrol in treating metabolic diseases seem to be versatile and the targets or pathways were diverse. Here, we systematically review the mechanism of action, and the therapeutic properties of celastrol in various metabolic diseases and complications. Based on this review, potential research strategies might contribute to the celastrol's clinical application in the future.

The Incidence of Erosive Esophagitis as a Complication of Pediatric Diabetic Ketoacidosis

Introduction

Gastrointestinal (GI) symptoms commonly occur during diabetic ketoacidosis (DKA) and typically resolve with treatment. However, GI complications can persist after DKA resolves. The incidence of upper GI bleeding during DKA in adults has been described, with erosive esophagitis one of the most common lesions. The incidence of GI bleeding or erosive esophagitis in children with DKA has not been previously reported. We performed a retrospective chart review of DKA admissions in children 0 to <18 years with type 1 diabetes mellitus (T1DM) at a pediatric hospital between January 2009 and July 2016. Among 395 episodes of DKA over 7.5 years, erosive esophagitis occurred during two DKA admissions (0.5%) and there were no episodes of GI bleeding. Case presentations. Both episodes of erosive esophagitis occurred in adolescent males with known T1DM who presented with severe DKA. Both developed odynophagia after resolution of DKA and were readmitted for DKA recurrence. Upper endoscopy for both patients showed erosive esophagitis. Biopsies were negative for infection, though candida was found during one patient's endoscopy. Both had resolution of their esophagitis symptoms with medication management; neither has had recurrence.

Conclusion

Erosive esophagitis, a rare complication of pediatric DKA, can manifest with odynophagia or substernal chest pain. This complication can lead to DKA recurrence, likely due to increased insulin resistance from inflammation and pain and from reduced oral intake and insulin administration. Patients with odynophagia associated with DKA should be monitored closely to allow timely evaluation and treatment of esophagitis.

NLRP3 inflammasome: a new therapeutic target for high-risk reproductive disorders?

ABSTRACT

The NOD-like receptor protein 3 (NLRP3) inflammasome is a key regulator of the host's immune response, and many immune and metabolic disorders are linked to its activation. This review aimed to investigate and clarify the relationship between this inflammasome and high-risk reproductive disorders. Papers cited here were retrieved from PubMed up to August 2020 using the keywords "NLRP3" or "NALP3", "caspase-1", "endometriosis", "gestational diabetes", "interleukin (IL)-18", "IL-1β", "pre-eclampsia (PE)", "preterm birth", "polycystic ovarian syndrome (PCOS)", "recurrent spontaneous abortion (RSA)", and combinations of these terms. The results show that NLRP3 inflammasome is associated with various high-risk reproductive disorders and many inflammatory factors are secreted during its activation, such as IL-1β induced during the development of endometriosis. PCOS is also associated with activation of the NLRP3 inflammasome, especially in overweight patients. It also participates in the pathogenesis of RSA and is activated in fetal membranes before preterm birth. The placentas of pregnant women with PE show higher expression of the NLRP3 inflammasome, and gestational diabetes mellitus occurs simultaneously with its activation. Current evidence suggest that the NLRP3 inflammasome plays an important role in female reproductive disorders. New treatment and management methods targeting it might help reduce the incidence of such disorders and improve neonatal outcomes.

Interaction of Adipocyte Metabolic and Immune Functions Through TBK1

Adipocytes and adipose tissue play critical roles in the regulation of metabolic homeostasis. In obesity and obesity-associated metabolic diseases, immune cells infiltrate into adipose tissues. Interaction between adipocytes and immune cells re-shapes both metabolic and immune properties of adipose tissue and dramatically changes metabolic set points. Both the expression and activity of the non-canonical IKK family member TBK1 are induced in adipose tissues during diet-induced obesity. TBK1 plays important roles in the regulation of both metabolism and inflammation in adipose tissue and thus affects glucose and energy metabolism. Here we review the regulation and functions of TBK1 and the molecular mechanisms by which TBK1 regulates both metabolism and inflammation in adipose tissue. Finally, we discuss the potential of a TBK1/IKKε inhibitor as a new therapy for metabolic diseases.

The Role of microRNAs in Metabolic Syndrome-Related Oxidative Stress

Oxidative stress (OxS) is the cause and the consequence of metabolic syndrome (MetS), the incidence and economic burden of which is increasing each year. OxS triggers the dysregulation of signaling pathways associated with metabolism and epigenetics, including microRNAs, which are biomarkers of metabolic disorders. In this review, we aimed to summarize the current knowledge regarding the interplay between microRNAs and OxS in MetS and its components. We searched PubMed and Google Scholar to summarize the most relevant studies. Collected data suggested that different sources of OxS (e.g., hyperglycemia, insulin resistance (IR), hyperlipidemia, obesity, proinflammatory cytokines) change the expression of numerous microRNAs in organs involved in the regulation of glucose and lipid metabolism and endothelium. Dysregulated microRNAs either directly or indirectly affect the expression and/or activity of molecules of antioxidative signaling pathways (SIRT1, FOXOs, Keap1/Nrf2) along with effector enzymes (e.g., GPx-1, SOD1/2, HO-1), ROS producers (e.g., NOX4/5), as well as genes of numerous signaling pathways connected with inflammation, insulin sensitivity, and lipid metabolism, thus promoting the progression of metabolic imbalance. MicroRNAs appear to be important epigenetic modifiers in managing the delicate redox balance, mediating either pro- or antioxidant biological impacts. Summarizing, microRNAs may be promising therapeutic targets in ameliorating the repercussions of OxS in MetS.

Interleukin-1β in hypothalamic paraventricular nucleus mediates excitatory renal reflex

Chemical stimulation of kidney causes sympathetic activation and pressor responses in rats. The excitatory renal reflex (ERR) is mediated by angiotensin type 1 receptor (AT₁R) and superoxide anions in hypothalamic paraventricular nucleus (PVN). The aim of this study is to determine whether interleukin-1β (IL-1β) in the PVN mediates the ERR, and whether the IL-1β production in the PVN is dependent on the AT₁R-superoxide anion signaling. Experiments were performed in adult rats under anesthesia. The ERR was induced by renal infusion of capsaicin, and evaluated by the responses of the contralateral renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP). Inhibition of IL-1β production with MCC950 in the PVN dose-dependently inhibited the capsaicin-induced ERR and sympathetic activation. The PVN microinjection of IL-1 receptor antagonist IL-1Ra or specific IL-1β antibody abolished the capsaicin-induced ERR, while IL-1β enhanced the ERR. Renal infusion of capsaicin promoted p65-NFκB phosphorylation and IL-1β production in the PVN, which were prevented by PVN microinjection of NADPH oxidase inhibitor apocynin or the superoxide anion scavenger tempol. The PVN microinjection of NFκB inhibitor BMS-345541 abolished the capsaicin induced-ERR and IL-1β production, but not the NADPH oxidase activation and superoxide anion production. Furthermore, capsaicin-induced p65-NFκB phosphorylation and IL-1β production in the PVN were prevented by AT₁R antagonist losartan, or angiotensin converting enzyme inhibitor captopril. These results indicate that capsaicin-induced ERR and sympathetic activation are mediated by IL-1β in the PVN. The IL-1β production in the PVN is dependent on the AT₁R-mediated superoxide anion generation and NFκB activation.

Impact of Intragastric Balloon Treatment on Adipokines, Cytokines, and Metabolic Profile in Obese Individuals

BACKGROUND

Obesity is accompanied by adipose tissue remodeling characterized by increased production of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, leptin and resistin and reduced secretion of adiponectin, which favors inflammation, metabolic disorders, and cardiovascular diseases. Although intragastric balloon (IGB) can be considered safe and effective for weight loss, its effect on serum levels of these biomarkers has been evaluated only in a few studies, while no previous study evaluated its effect on circulating levels of resistin, TNF-α, and IL-6. The aim of this study was to evaluate the changes in serum levels of metabolic and inflammatory biomarkers in obese patients submitted to IGB treatment.

METHODS

A prospective observational study involving 42 patients with obesity using IGB for 6 months. The patients were evaluated, on the day of insertion and withdrawal or adjustment of IGB, for the following: anthropometric measures and serum levels of adiponectin, leptin, resistin, TNF-α, IL-6, high-sensitivity C-reactive protein (hs-CRP), glucose, insulin, uric acid, triglycerides, and total cholesterol and fractions.

RESULTS

The body mass index decreased from 35.15 ± 0.41 to 29.50 ± 0.54 kg/m². There was a reduction (p < 0.05) in leptin, hs-CRP, glucose, insulin, HOMA-IR, and triglycerides, while the adiponectin/leptin ratio increased (p < 0.05). Moreover, weight loss presented (1) a positive association with the decrease in leptin, hs-CRP, glucose, insulin, HOMA-IR, uric acid, and total cholesterol and (2) a negative association with the reduction in adiponectin/leptin ratio.

CONCLUSIONS

The present study suggests that 6 months of IGB treatment in obese individuals reduce serum leptin and hs-CRP and improves insulin resistance and lipid profile which may decrease cardiovascular risk.

PFKFB3, a key glucose metabolic enzyme regulated by pathogen recognition receptor TLR4 in liver cells

AIMS

Toll-like receptor 4 (TLR4) and 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase (PFKFB3) are involved in the progress of inflammation and glucose metabolism. Here, we aimed to assess the relationship between TLR4 and PFKFB3 in liver cells.

METHODS

We detected the expression of TLR4 and PFKFB3 in both normal liver cell lines and liver cancer cell lines. Then, a small interfering RNA (siRNA) was used to knock down the expression of TLR4 and analyze the expression of PFKFB3 in the HL-7702 cell line. Further, following stimulation of the HL-7702 cell line with free fatty acids (FFA) or insulin, we observed the expression of TLR4 and PFKFB3, respectively.

RESULTS

Knocking down siRNA-mediated TLR4 significantly reduced PFKFB3 expression at the mRNA and protein level. Furthermore, activating TLR4 with FFA dramatically increased PFKFB3 expression. Insulin increased the expression of TLR4 and PFKFB3, which could be inhibited by TLR siRNA.

CONCLUSION

These findings suggest that PFKFB3 expression is regulated via the TLR4-PFKFB3 axis, which might be a bridge linking fat and glucose metabolism.

Contribution of Oxidative Stress and Impaired Biogenesis of Pancreatic β-Cells to Type 2 Diabetes

Significance: Type 2 diabetes development involves multiple changes in β-cells, related to the oxidative stress and impaired redox signaling, beginning frequently by sustained overfeeding due to the resulting lipotoxicity and glucotoxicity. Uncovering relationships among the dysregulated metabolism, impaired β-cell "well-being," biogenesis, or cross talk with peripheral insulin resistance is required for elucidation of type 2 diabetes etiology. Recent Advances: It has been recognized that the oxidative stress, lipotoxicity, and glucotoxicity cannot be separated from numerous other cell pathology events, such as the attempted compensation of β-cell for the increased insulin demand and dynamics of β-cell biogenesis and its "reversal" at dedifferentiation, that is, from the concomitantly decreasing islet β-cell mass (also due to transdifferentiation) and low-grade islet or systemic inflammation. Critical Issues: At prediabetes, the compensation responses of β-cells, attempting to delay the pathology progression-when exaggerated-set a new state, in which a self-checking redox signaling related to the expression of Ins gene expression is impaired. The resulting altered redox signaling, diminished insulin secretion responses to various secretagogues including glucose, may lead to excretion of cytokines or chemokines by β-cells or excretion of endosomes. They could substantiate putative stress signals to the periphery. Subsequent changes and lasting glucolipotoxicity promote islet inflammatory responses and further pathology spiral. Future Directions: Should bring an understanding of the β-cell self-checking and related redox signaling, including the putative stress signal to periphery. Strategies to cure or prevent type 2 diabetes could be based on the substitution of the "wrong" signal by the "correct" self-checking signal.

Dendrimer Based Nanoarchitectures in Diabetes Management: An Overview

Diabetes has turned out to be one of the biggest worldwide health and economic burdens, with its expanded predominance and high complexity proportion. The quantity of diabetic patients is expanding enormously around the world. Several reports have demonstrated the sharp increment in the sufferers. Stable and acceptable blood glucose control is fundamental to diminish diabetes-related complications. Consequently, ceaseless endeavors have been made in antidiabetic drugs, treatment strategies, and nanotechnology based products to accomplish better diabetes control. The nanocarriers pertaining hypoglycaemics provide improved diabetes management with minimum risk of associated side effects. Dendrimers have caught an incredible attention in the field of drug delivery and personalized medicines. Dendrimers are three-dimensional well-defined homogenous nanosized structures consisting tree-like branches. The present review highlights the different aspects of dendrimers including fabrication, surface engineering, toxicological profile as well as delivery of antidiabetic drugs for the effective cure of diabetes.