Protein kinases: mechanisms and downstream targets in inflammation-mediated obesity and insulin resistance

DDIT4 participates in high glucose-induced fibroblast-like synoviocytes overactivation and cartilage injury by regulating glycolysis

Objective

More and more evidence show that diabetes is closely related to osteoarthritis (OA). However, the role and mechanism of DNA damage-inducible transcript 4 protein (DDIT4) in diabetic OA (DOA) have not been clarified.

Methods

We collected OA patients and non-OA subjects who underwent total knee replacement surgery, and analyzed the DDIT4 expression in synovial samples using RT-qPCR. The cell viability of fibroblast-like synoviocytes (FLSs) was measured by CCK-8 assay. Annexin V-FITC/PI double staining was used to detect the cell apoptosis. Scratch and Transwell assays were used to determine cell migration and invasion, respectively.

Results

The levels of cellular inflammatory factors (IL-1β, IL-6 and TNF-α), oxidative stress and glycolysis related indicators were detected by using kits. Western blot was used to determine the expression of DDIT4, Aggrecan, COL3A1, MMP3, MMP13, HK2, PFKP and PKM2 in FLSs or ATDC5 cells. The results showed that the expression level of DDIT4 was significantly reduced in the synovial samples of OA patients and primary FLSs. Functional studies showed that DDIT4 overexpression inhibited the overactivation, migration, and invasion of FLSs, as well as alleviated chondrocyte injury co-cultured with FLSs. Importantly, the expression of DDIT4 was down-regulated in patients with DOA and closely related to DOA. Further research found that high glucose (HG) promoted excessive activation, migration, and invasion of FLSs, and exacerbated the followed chondrocyte injury. Overexpression of DDIT4 alleviated HG-induced abnormal function of FLSs and injury to chondrocytes. Importantly, DDIT4 inhibited lactate synthesis, glucose uptake, LDH activity, extracellular acidification rate, oxygen consumption rate, and expression levels of glycolysis related protein (HK2, PFKP, PKM2) in HG-induced FLSs. And the glycolysis inhibitors (Cyto-B and 3BrPA) alleviated the injury of ATDC5 chondrocytes co-cultured with FLSs.

Conclusions

DDIT4 participates in HG-induced FLSs overactivation and inflammation response, as well as chondrocyte injury and OA progression by regulating glycolysis processes.

Protective Effects of Lotus Seedpod Extract on Hepatic Lipid and Glucose Metabolism via AMPK-Associated Mechanisms in a Mouse Model of Metabolic Syndrome and Oleic Acid-Induced HepG2 Cells

Metabolic syndrome (MetS) poses considerable toxicological risks due to its association with an increased likelihood of metabolic dysfunction-associated steatotic liver disease (MASLD), and is characterized by hypertension, hyperglycemia, dyslipidemia, and obesity. This study aimed to investigate the therapeutic potential of flavonoid-rich lotus seedpod extract (LSE) in alleviating MetS and MASLD-related hepatic disturbances. In vivo, mice subjected to a high-fat diet (HFD) and streptozotocin (STZ) injection were supplemented with LSE or simvastatin for 6 weeks. Obesity indicators included body weight and epididymal fat, while insulin resistance was measured by fasting serum glucose, serum insulin, homeostasis model assessment-insulin resistance index (HOMA-IR), and oral glucose tolerance (OGTT). Also, the levels of serum lipid profiles and blood pressure were evaluated. Adipokines, proinflammatory cytokines, liver fat droplets, and peri-portal fibrosis were analyzed to clarify the mechanism of MetS. LSE significantly reduced the HFD/STZ-induced MetS markers better than simvastatin, as demonstrated by hypoglycemic, hypolipidemic, antioxidant, and anti-inflammatory effects. In vitro, LSE improved oleic acid (OA)-triggered phenotypes of MASLD in hepatocyte HepG2 cells by reducing lipid accumulation and enhancing cell viability. This effect might be mediated through proteins involved in lipogenesis that are downregulated by adenosine monophosphate-activated protein kinase (AMPK). In addition, LSE reduced reactive oxygen species (ROS) generation and glycogen levels, as demonstrated by enhancing insulin signaling involving reducing insulin receptor substrate-1 (IRS-1) Ser307 phosphorylation and increasing glycogen synthase kinase 3 beta (GSK3β) and protein kinase B (PKB) expression. These benefits were dependent on AMPK activation, as confirmed by the AMPK inhibitor compound C. These results indicate that LSE exhibits protective effects against MetS-caused toxicological disturbances in hepatic carbohydrate and lipid metabolism, potentially contributing to its efficacy in preventing MASLD or MetS.

The role of ERK1/2 signaling in diabetes: pathogenic and therapeutic implications

ERK1/2 (extracellular signal-regulated kinase 1/2) is an important member of the MAPK (mitogen-activated protein kinase) family and is widely involved in many biological processes such as cell proliferation, differentiation, apoptosis and migration. After activation by phosphorylation, ERK1/2 can be transferred into the nucleus and directly or indirectly affect the activity of transcription factors, thereby regulating gene expression. More and more studies have shown that ERK1/2 plays an important role in diabetes and its complications, such as insulin secretion, islet β cell function, diabetic cardiomyopathy, diabetic nephropathy, renal fibrosis, lipogenesis, diabetic vasculopathy, etc. These effects reveal the complexity and diversity of the ERK1/2 signaling pathway in the pathogenesis of diabetes, and its activation and inhibition mechanisms in multiple physiological and pathological processes provide potential targets for diabetes treatment. The purpose of this mini-review is to explore the key role of ERK1/2 in diabetes and the progress of research on targeted inhibitors of ERK1/2, which provides new strategies for the treatment of diabetes.

Nutrition, Gut Microbiota, and Epigenetics in the Modulation of Immune Response and Metabolic Health

Immune system function is intricately shaped by nutritional status, dietary patterns, and gut microbiota composition. Micronutrients such as vitamins A, C, D, E, B-complex, zinc, selenium, iron, and magnesium are critical for maintaining physical barriers, supporting immune cell proliferation, and regulating inflammation. Macronutrients-including proteins, fats, and carbohydrates-also modulate immune responses through their impact on immune metabolism and the gut-immune axis. Epigenetic mechanisms, including DNA methylation, histone modifications, and microRNA expression, mediate the long-term effects of diet on immune function and tolerance. Diet-induced alterations in gut microbiota further influence immune homeostasis via microbial metabolites like short-chain fatty acids. Imbalanced diets, particularly the Western diet, contribute to immune dysregulation, chronic inflammation, and the development of metabolic disorders such as obesity and type 2 diabetes. While plant-based and Mediterranean dietary patterns have shown anti-inflammatory and immunoregulatory benefits, gaps remain in understanding the long-term epigenetic impacts of these diets. This review integrates current knowledge on how nutrition and the microbiome regulate immunity, highlighting future directions for personalized dietary strategies in preventing chronic immune-related conditions.

Peripheral Inflammation and Insulin Resistance: Their Impact on Blood-Brain Barrier Integrity and Glia Activation in Alzheimer's Disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline, memory impairment, and synaptic dysfunction. The accumulation of amyloid beta (Aβ) plaques and hyperphosphorylated tau protein leads to neuronal dysfunction, neuroinflammation, and glial cell activation. Emerging evidence suggests that peripheral insulin resistance and chronic inflammation, often associated with type 2 diabetes (T2D) and obesity, promote increased proinflammatory cytokines, oxidative stress, and immune cell infiltration. These conditions further damage the blood-brain barrier (BBB) integrity and promote neurotoxicity and chronic glial cell activation. This induces neuroinflammation and impaired neuronal insulin signaling, reducing glucose metabolism and exacerbating Aβ accumulation and tau hyperphosphorylation. Indeed, epidemiological studies have linked T2D and obesity with an increased risk of developing AD, reinforcing the connection between metabolic disorders and neurodegeneration. This review explores the relationships between peripheral insulin resistance, inflammation, and BBB dysfunction, highlighting their role in glial activation and the exacerbation of AD pathology.

Impact of Maternal Ultra-Processed Food Consumption and Preterm Birth on the Development of Metabolic Disorders in Offspring

This review examines the growing concern regarding the relationship between maternal ultra-processed food (UPF) consumption, preterm birth, and the subsequent development of metabolic disorders in offspring. Ultra-processed foods have become increasingly prevalent in global diets, coinciding with rising rates of metabolic diseases. Concurrently, preterm birth remains a significant public health concern affecting 5-18% of births worldwide. Here, we critically reviewed the current evidence regarding how maternal UPF consumption affects fetal development and how preterm birth disrupts metabolic programming. Furthermore, the information is presented on the potential synergistic effects when both factors are present. The mechanisms underlying these associations, including fetal malnutrition, inflammation, and hormonal dysregulation, are analyzed. Research suggests that maternal UPF consumption and preterm birth independently contribute to altered metabolic health in offspring, with potential compounding effects when both factors are present. This review highlights the public health implications of these findings and identifies areas requiring further research to better understand the complex interplay between maternal diet, preterm birth, and long-term metabolic health outcomes in offspring.

Vinegar-processed Schisandra chinensis polysaccharide ameliorates type 2 diabetes via modulation serum metabolic profiles, gut microbiota, and fecal SCFAs

Numerous studies indicate that Schisandra chinensis (Turcz.) Baill (SC) has anti-type 2 diabetes mellitus (T2DM) effects, and its processed products are commonly used in clinical practice. However, limited reports exist on the mechanisms of polysaccharides from its vinegar products and their role in T2DM. We purified a novel polysaccharide from vinegar-processed Schisandra chinensis (VSC) and used intestinal microbiota 16S rRNA analysis and metabolomics to study changes in T2DM mice after vinegar-processed Schisandra chinensis polysaccharide (VSP) intervention, aiming to elucidate how VSP alleviates T2DM. VSP has shown significant therapeutic effects in T2DM mice, which can regulate the imbalance of glucose and lipid metabolism, alleviate pancreatic and liver damage, restore the integrity of the intestinal barrier, and inhibit the inflammatory response. Serum metabolomics and microbiological analysis showed that VSP could significantly regulate 104 endogenous metabolites and rectify gut microbiota disorders in T2DM mice. Additionally, VSP enhanced the levels of short-chain fatty acids (SCFAs) and the expression of GPR41/43 in the colon of T2DM mice. Correlation analysis revealed significant correlations among specific gut microbiota, serum metabolites, and fecal SCFAs. Overall, these findings will provide a basis for further VSP development.

Multi-omics architecture of childhood obesity and metabolic dysfunction uncovers biological pathways and prenatal determinants

Childhood obesity poses a significant public health challenge, yet the molecular intricacies underlying its pathobiology remain elusive. Leveraging extensive multi-omics profiling (methylome, miRNome, transcriptome, proteins and metabolites) and a rich phenotypic characterization across two parts of Europe within the population-based Human Early Life Exposome project, we unravel the molecular landscape of childhood obesity and associated metabolic dysfunction. Our integrative analysis uncovers three clusters of children defined by specific multi-omics profiles, one of which characterized not only by higher adiposity but also by a high degree of metabolic complications. This high-risk cluster exhibits a complex interplay across many biological pathways, predominantly underscored by inflammation-related cascades. Further, by incorporating comprehensive information from the environmental risk-scape of the critical pregnancy period, we identify pre-pregnancy body mass index and environmental pollutants like perfluorooctanoate and mercury as important determinants of the high-risk cluster. Overall, our work helps to identify potential risk factors for prevention and intervention strategies early in the life course aimed at mitigating obesity and its long-term health consequences.

The correlation between HOMA-IR and cardiometabolic risk index among different metabolic adults: a cross-sectional study

AIMS

This study aimed to explore the correlation between homeostasis model assessment of insulin resistance(HOMA-IR)and cardiometabolic risk index(CMRI) among different metabolic adults to evaluate the value of HOMA-IR in predicting cardiometabolic risk.

METHODS

This cross-sectional study was conducted over 18 months (from August 1, 2020 to February 18, 2022) and included 1550 participants divided into non-metabolic syndrome (non-MetS) group (n = 628) and metabolic syndrome (MetS) group (n = 922) in three centers of China. Logistic regression analysis was employed to investigate the correlation between HOMA-IR, body fat percentage, BMI (body mass index), visceral fat index, waist-to-hip ratio, vitamin D, and CMRI. Further analysis was conducted to evaluate the ability of HOMA-IR in diagnosing high CMRI within different metabolic, gender, and age groups to predict the risk of cardiovascular disease (CVD).

RESULTS

HOMA-IR was significantly higher in the MetS group compared with the non-MetS group (P < 0.05). CMRI was significantly higher in the MetS group compared to the non-MetS group (P < 0.05). According to ROC curve analysis, HOMA-IR can predict cardiovascular risk (CVR) in the general population, non-MetS individuals, and MetS people. Logistic regression analysis revealed that BMI, visceral fat index, waist-to-hip ratio, and HOMA-IR are independent risk indicators of high CVR, whereas vitamin D may exert a protective role.

CONCLUSIONS

HOMA-IR was an independent risk factor for increased CVR in MetS patients. Moreover, HOMA-IR elevates the risk of CVD regardless of MetS and thus can be used for screening the general population.

TRIAL REGISTRATION

The study was registered at the Chinese Clinical Trial Registry (Registration Number: ChiCTR2100054654).

Diabetes and its Silent Partner: A Critical Review of Hyperinsulinemia and its Complications

In this complex realm of diabetes, hyperinsulinemia is no longer regarded as just a compensatory response to insulin resistance but rather has evolved into an integral feature. This comprehensive review provides a synthesis of the current literature, including various aspects associated with hyperinsulinemia in diabetic complications. Hyperinsulinemia has been shown to be more than just a compensatory mechanism, and the key findings demonstrate how hyperinsulinism affects the development of cardiovascular events as well as microvascular complications. Additionally, recognizing hyperinsulinemia as a modifiable factor, the diabetes management paradigm shifts towards cognitive ones that consider the use of lifestyle modifications in combination with newer pharmacotherapies and precision medicine approaches. These findings have crucial implications for the clinical work, requiring a careful appreciation of hyperinsulinemia's changing aspects as well as incorporation in personalized treatment protocol. In addition, the review focuses on bigger issues related to public health, showing that prevention and early diagnosis will help reduce the burden of complications. Research implications favor longitudinal studies, biomarker discovery, and the study of emerging treatment modalities; clinical practice should adopt global evaluations, patient education, and precision medicine adaptation. Finally, this critical review provides an overview of the underlying processes of hyperinsulinemia in diabetes and its overall health effects.

Omega-3 Fatty Acid and Vitamin D Supplementations Partially Reversed Metabolic Disorders and Restored Gut Microbiota in Obese Wistar Rats

Obesity is a global public health issue linked to various comorbidities in both humans and animals. This study investigated the effects of vitamin D (VD) and omega-3 fatty acids (ω3FA) on obesity, gut dysbiosis, and metabolic alterations in Wistar rats. After 13 weeks on a standard (S) or High-Fat, High-Sugar (HFHS) diet, the rats received VD, ω3FA, a combination (VD/ω3), or a control (C) for another 13 weeks. The HFHS diet led to increased weight gain, abdominal circumference, glucose intolerance, insulin resistance, and gut dysbiosis. VD supplementation improved their fasting blood glucose and reduced liver damage, while ω3FA slowed BMI progression, reduced abdominal fat, liver damage, and intestinal permeability, and modulated the gut microbiota. The combination of VD/ω3 prevented weight gain, decreased abdominal circumference, improved glucose tolerance, and reduced triglycerides. This study demonstrates that VD and ω3FA, alone or combined, offer significant benefits in preventing obesity, gut dysbiosis, and metabolic alterations, with the VD/ω3 combination showing the most promise. Further research is needed to explore the mechanisms behind these effects and their long-term potential in both animal and human obesity management.

Hydrogen sulfide mitigates mitochondrial dysfunction and cellular senescence in diabetic patients: Potential therapeutic applications

Diabetes induces a pro-aging state characterized by an increased abundance of senescent cells in various tissues, heightened chronic inflammation, reduced substance and energy metabolism, and a significant increase in intracellular reactive oxygen species (ROS) levels. This condition leads to mitochondrial dysfunction, including elevated oxidative stress, the accumulation of mitochondrial DNA (mtDNA) damage, mitophagy defects, dysregulation of mitochondrial dynamics, and abnormal energy metabolism. These dysfunctions result in intracellular calcium ion (Ca2+) homeostasis disorders, telomere shortening, immune cell damage, and exacerbated inflammation, accelerating the aging of diabetic cells or tissues. Hydrogen sulfide (H2S), a novel gaseous signaling molecule, plays a crucial role in maintaining mitochondrial function and mitigating the aging process in diabetic cells. This article systematically explores the specific mechanisms by which H2S regulates diabetes-induced mitochondrial dysfunction to delay cellular senescence, offering a promising new strategy for improving diabetes and its complications.

Transcriptomics of Subcutaneous Tissue of Lipedema Identified Differentially Expressed Genes Involved in Adipogenesis, Inflammation, and Pain

Background

Lipedema is a disease typically affecting women with a symmetrical, painful fat distribution disorder, which is hypothesized to be caused by impaired adipogenesis, inflammation, and extracellular matrix remodeling, leading to fibrosis and the development of edema in lipedema subcutaneous adipose tissue. The pathogenesis and molecular processes leading to lipedema have not yet been clarified.

Methods

A whole transcriptome analysis of subcutaneous tissue of lipedema stages I (n = 12), II (n = 9), and III (n = 8) compared with hypertrophied subcutaneous tissue (n = 4) was performed. Further data about hormonal substitution and body morphology were collected. The study is registered at ClinicalTrials.gov (NCT05861583).

Results

We identified several differentially expressed genes involved in mechanisms leading to the development of lipedema. Some genes, such as PRKG2, MEDAG, CSF1R, BICC1, ERBB4, and ACP5, are involved in adipogenesis, regulating the development of mature adipocytes from mesenchymal stem cells. Other genes, such as MAFB, C1Q, C2, CD68, CD209, CD163, CD84, BCAT1, and TREM2, are predicted to be involved in lipid accumulation, hypertrophy, and the inflammation process. Further genes such as SHTN1, SCN7A, and SCL12A2 are predicted to be involved in the regulation and transmission of pain.

Conclusions

In summary, the pathogenesis and development of lipedema might be caused by alterations in adipogenesis, inflammation, and extracellular matrix remodeling, leading to fibrosis and the formation of edema resulting in this painful disease. These processes differ from hypertrophied adipose tissue and may therefore play a main role in the formation of lipedema.

Investigating the Mechanism of Banxia Xiexin Decoction in Treating Gastritis and Diabetes Mellitus through Network Pharmacology and Molecular Docking Analysis

Background:

Banxia Xiexin decoration (BXD), a complex prescription in Traditional Chinese Medicine (TCM), clinically acts as a treatment for gastritis and diabetes while its mechanism of treatment remains unknown.

Objection:

This study aimed to explore the common mechanism of BXD in treating gastritis and diabetes based on network pharmacology and molecular docking technology.

Methods:

The seven Chinese herbal components and drug targets were collected from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) for gastritis and diabetes using GeneCards, DisGeNET, Comparative Toxicogenomics Database (CTD), and Online Mendelian Inheritance in Man (OMIM) databases. Common drug and disease targets were imported into the STRING data platform for protein-protein interaction (PPI) analysis, and Cytoscape 3.7.2 software for network topology analysis, and core targets were filtered.

Results:

There were 124 components, 249 targets, 449 targets for gastritis, and 4005 targets for diabetes. After mapping, 83 BXD targets for gastritis and diabetes were obtained, and the targets with high correlation were STAT 3, JUN, TNF, IL-6, etc. More relevant targets were involved in the cancer pathway, AGE-RAGE signaling pathway of diabetic complications, fluid shear stress, and atherosclerosis pathway.

Conclusion:

This study preliminarily reveals that BXD may play a role in the treatment of gastritis and diabetes mellitus through multi-components, multi-targets, and multi-pathways, and proposes some potential "component-target-pathway" hypotheses in light of previous reports.

The neuroprotective role of celastrol on hippocampus in diabetic rats by inflammation restraint, insulin signaling adjustment, Aβ reduction and synaptic plasticity alternation

Celastrol, the primary constituent of Tripterygium wilfordii, has demonstrated neuroprotective properties in rats with dementia by reducing inflammation. A high-fat diet and streptozotocin injection were utilized to establish a diabetic rat model, which was then employed to investigate the possible protective effect of celastrol against the development of diabetes-induced learning and memory deficits. Afterwards, the experimental animals received a dose of celastrol by gavage (4 mg/kg/d). An animal study showed that celastrol enhanced insulin sensitivity and glucose tolerance in diabetic rats. In the Morris water maze test, rats with diabetes performed poorly in terms of spatial learning and memory; treatment with celastrol improved these outcomes. Additionally, administration of celastrol downregulated the expression of inflammatory-related proteins (NF-κB, IKKα, TNF-α, IL-1β, and IL-6) and greatly reduced the generation of Aβ in the diabetic hippocampus tissue. Moreover, the insulin signaling pathway-related proteins PI3K, AKT, and GSK-3β were significantly upregulated in diabetic rats after celastrol was administered. Also, celastrol prevented damage to the brain structures and increased the synthesis of synaptic proteins like PSD-95 and SYT1. In conclusion, celastrol exerts a neuroprotective effect by modulating the insulin signaling system and reducing inflammatory responses, which helps to ameliorate the cognitive impairment associated with diabetes.

The burden of cancer in metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most prevalent chronic liver disease worldwide and has become a major public health problem. MASLD frequently progresses to cirrhosis and hepatocellular carcinoma, but recent studies also show a frequent association with extrahepatic cancers. One of the mechanisms involved in both locations is insulin resistance and hyperinsulinemia. The aim of this narrative review was to present the main etiopathogenic mechanisms involved in cancer development in patients with MASLD.

Endodontic Treatment of Chronic Apical Periodontitis Ameliorates Systemic Inflammation and Restores Impaired Cellular Responses to Insulin in an In Vitro Model

INTRODUCTION

A growing body of research supports an association between periapical inflammation and an increased risk of developing systemic diseases. There is currently no scientific evidence to support a causal effect of inflammation on the onset of insulin resistance (IR) in patients with apical periodontitis (AP). The aim of this in vitro study was to evaluate any association between AP and levels of serum inflammatory factors potentially associated with the onset of IR, and to investigate the effect of root canal treatment (RCT) on these systemic inflammation markers and on the response in vitro to insulin.

METHODS

A total of 27 control subjects and 27 patients with AP were enrolled. Patients with AP underwent RCT and were followed-up 6 and 12 months post-treatment. Enzyme-linked immunosorbent assays were used to evaluate serum levels of proinflammatory cytokines interleukin (IL)-1, IL-6, IL-8, and tumor necrosis factor (TNF)-α. The response in vitro to insulin was assessed by measuring glucose consumption in a human pancreatic epithelioid carcinoma cell line treated with sera from healthy and AP subjects.

RESULTS

At baseline AP was associated with significant higher levels of IL-1, IL-6, and IL-8 in the serum of untreated (AP) patients vs controls (P < .001). Glucose consumption decreased in pancreatic cells incubated with baseline serum from patients with AP, in a manner proportional to total cytokines amount. Notably, endodontic treatment was associated with reduced levels of cytokines (P < .001) and improved response to insulin in AP group (P < .001).

CONCLUSIONS

Our findings suggest that AP may promote inflammatory-driven IR in an in vitro model, and that RCT may ameliorate inflammatory mediators in vivo and the cellular response to insulin in vitro.

Deciphering the role of classical oestrogen receptor in insulin resistance and type 2 diabetes mellitus: From molecular mechanism to clinical evidence

The biological actions of oestrogen are mediated by the oestrogen receptor α or β (ERα or ERβ), which are members of a broad nuclear receptor superfamily. Numerous in vivo and in vitro studies have demonstrated that loss of circulating oestrogen modulated by classical ERα and ERβ led to rapid changes in pancreatic β-cell and islet function, GLUT4 expression, insulin sensitivity and glucose tolerance, dysfunctional lipid homeostasis, oxidative stress, and inflammatory cascades. Remarkably, 17β-oestradiol (E2) can completely reverse these effects. This review evaluates the current understanding of the protective role of classical ER in critical pathways and molecular mechanisms associated with insulin resistance and type 2 diabetes mellitus (T2DM). It also examines the effectiveness of menopausal hormone therapy (MHT) in reducing the risk of developing T2DM in menopausal women. Clinical trials have shown the protective effects of MHT on glucose metabolism, which may be useful to treat T2DM in perimenopausal women. However, there are concerns about E2's potential side effects of obesity and hyperlipidaemia in menopausal women. Further studies are warranted to gain understanding and find other oestrogen alternatives for treatment of insulin resistance and T2DM in postmenopausal women.

Activation and modulation of the AGEs-RAGE axis: Implications for inflammatory pathologies and therapeutic interventions - A review

Chronic inflammation is a common foundation for the development of many non-communicable diseases, particularly diabetes, atherosclerosis, and tumors. The activation of the axis involving Advanced Glycation End products (AGEs) and their receptor RAGE is a key promotive factor in the chronic inflammation process, influencing the pathological progression of these diseases. The accumulation of AGEs in the body results from an increase in glycation reactions and oxidative stress, especially pronounced in individuals with diabetes. By binding to RAGE, AGEs activate signaling pathways such as NF-κB, promoting the release of inflammatory factors, exacerbating cell damage and inflammation, and further advancing the formation of atherosclerotic plaques and tumor development. This review will delve into the molecular mechanisms by which the AGEs-RAGE axis activates chronic inflammation in the aforementioned diseases, as well as strategies to inhibit the AGEs-RAGE axis, aiming to slow or halt the progression of chronic inflammation and related diseases. This includes the development of AGEs inhibitors, RAGE antagonists, and interventions targeting upstream and downstream signaling pathways. Additionally, the early detection of AGEs levels and RAGE expression as biomarkers provides new avenues for the prevention and treatment of diabetes, atherosclerosis, and tumors.

Effect of Cytokeratin-18, C-peptide, MHR, and MACK-3 Biomarkers in Metabolic Dysfunction-Associated Fatty Liver Disease After Laparoscopic Sleeve Gastrectomy

Background

Laparoscopic sleeve gastrectomy (LSG) has emerged as a valuable treatment for various metabolic disorders, including metabolic dysfunction-associated fatty liver disease (MAFLD) in patients with obesity. Consequently, there is a pressing need to develop noninvasive biomarkers for diagnosing and monitoring disease progression.

Objectives

This study aimed to evaluate specific biomarkers, including Cytokeratin-18 (CK-18), C-peptide, monocyte to HDL cholesterol ratio (MHR), and MACK-3, in patients with obesity with MAFLD undergoing LSG.

Design

A prospective cohort study on patients with obesity before and 6 months after the LSG procedure.

Methods

70 patients with obesity with confirmed MAFLD, determined by Transient Elastography (TE), were pre- and 6 months postoperatively tested. Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), lipid profile, ghrelin, leptin, peptide YY, GLP-1, and liver fibrosis scores, including AST/ALT ratio (AAR), Fibrosis-4 index (FIB-4), and BARD Score were tested.

Results

BMI significantly decreased in all participants, with a % excess weight loss of 62.0% ± 15.4%. TE measurements revealed a significant postoperative reduction from 100% to 87.1% (P = .006). All selected biomarkers showed significant postoperative improvement-a significant association of CK-18 with MAFLD markers, including AAR, FIB-4, and BARD score, were found. MACK-3 had positive associations with FIB-4. C-peptide and MHR showed no association with MAFLD markers. Furthermore, there was a positive correlation between CK-18 and MACK-3 tests and between C-peptide and CK-18 and MACK-3. Additionally, a receiver operating characteristic (ROC) curve was constructed, with CK-18 performing the best, with an estimated area under the curve of 0.863.

Conclusion

Serum CK-18 outperformed other selected biomarkers in predicting and monitoring MAFLD in patients with obesity, suggesting its prospective utility in clinical practice. Further studies are needed to validate the accuracy of the MACK-3 test.

Frontiers in sarcopenia: Advancements in diagnostics, molecular mechanisms, and therapeutic strategies

The onset of sarcopenia is intimately linked with aging, posing significant implications not only for individual patient quality of life but also for the broader societal healthcare framework. Early and accurate identification of sarcopenia and a comprehensive understanding of its mechanistic underpinnings and therapeutic targets paramount to addressing this condition effectively. This review endeavors to present a cohesive overview of recent advancements in sarcopenia research and diagnosis. We initially delve into the contemporary diagnostic criteria, specifically referencing the European Working Group on Sarcopenia in Older People (EWGSOP) 2 and Asian Working Group on Sarcopenia (AWGS) 2019 benchmarks. Additionally, we elucidate comprehensive assessment techniques for muscle strength, quantity, and physical performance, highlighting tools such as grip strength, chair stand test, dual-energy X-ray Absorptiometry (DEXA), bioelectrical impedance analysis (BIA), gait speed, and short physical performance battery (SPPB), while also discussing their inherent advantages and limitations. Such diagnostic advancements pave the way for early identification and unequivocal diagnosis of sarcopenia. Proceeding further, we provide a deep-dive into sarcopenia's pathogenesis, offering a thorough examination of associated signaling pathways like the Myostatin, AMP-activated protein kinase (AMPK), insulin/IGF-1 Signaling (IIS), and the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways. Each pathway's role in sarcopenia mediation is detailed, underscoring potential therapeutic target avenues. From a mechanistic perspective, the review also underscores the pivotal role of mitochondrial dysfunction in sarcopenia, emphasizing elements such as mitochondrial oxidative overload, mitochondrial biogenesis, and mitophagy, and highlighting their therapeutic significance. At last, we capture recent strides made in sarcopenia treatment, ranging from nutritional and exercise interventions to potential pharmacological and supplementation strategies. In sum, this review meticulously synthesizes the latest scientific developments in sarcopenia, aiming to enhance diagnostic precision in clinical practice and provide comprehensive insights into refined mechanistic targets and innovative therapeutic interventions, ultimately contributing to optimized patient care and advancements in the field.

Schisandrin A Alleviates Spatial Learning and Memory Impairment in Diabetic Rats by Inhibiting Inflammatory Response and Through Modulation of the PI3K/AKT Pathway

Clinical and epidemiological research shows that people with diabetes mellitus frequently experience diabetic cognitive impairment. Schisandrin A (SchA), one of the lignans found in the dried fruit of Schisandra chinensis, has a variety of pharmacological effects on immune system control, apoptosis suppression, anti-oxidation and anti-inflammation. The goal of the current investigation was to clarify the probable neuro-protective effects of SchA against streptozotocin-induced diabetes deficiencies of the spatial learning and memory in rats. The outcomes show that SchA therapy effectively improved impaired glucose tolerance, fasting blood glucose level and serum insulin level in diabetic rats. Additionally, in the Morris water maze test, diabetic rats showed deficits in spatial learning and memory that were ameliorated by SchA treatment. Moreover, giving diabetic rats SchA reduced damage to the hippocampus structure and increased the production of synaptic proteins. Further research revealed that SchA therapy reduced diabetic-induced hippocampus neuron damage and the generation of Aβ, as demonstrated by the upregulated phosphorylation levels of insulin signaling pathway connected proteins and by the decreased expression levels of inflammatory-related factors. Collectively, these results suggested that SchA could improve diabetes-related impairments in spatial learning and memory, presumably by reducing inflammatory responses and regulating the insulin signaling system.

Low concentrations of α-lipoic acid reduce palmitic acid-induced alterations in murine hypertrophic adipocytes

Obesity is a metabolic disorder with excessive body fat accumulation, increasing incidence of chronic metabolic diseases. Hypertrophic obesity is associated with local oxidative stress and inflammation. Herein, we evaluated the in vitro activity of micromolar concentrations of α-lipoic acid (ALA) on palmitic acid (PA)-exposed murine hypertrophic 3T3-L1 adipocytes, focussing on the main molecular pathways involved in adipogenesis, inflammation, and insulin resistance. ALA, starting from 1 µM, decreased adipocytes hypertrophy, reducing PA-triggered intracellular lipid accumulation, PPAR-γ levels, and FABP4 gene expression, and counteracted PA-induced intracellular ROS levels and NF-κB activation. ALA reverted PA-induced insulin resistance, restoring PI3K/Akt axis and inducing GLUT-1 and glucose uptake, showing insulin sensitizing properties since it increased their basal levels. In conclusion, this study supports the potential effects of low micromolar ALA against hypertrophy, inflammation, and insulin resistance in adipose tissue, suggesting its important role as pharmacological supplement in the prevention of conditions linked to obesity and metabolic syndrome.

Ferroptosis and metabolic syndrome and complications: association, mechanism, and translational applications

Metabolic syndrome is a medical condition characterized by several metabolic disorders in the body. Long-term metabolic disorders raise the risk of cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM). Therefore, it is essential to actively explore the aetiology of metabolic syndrome (MetS) and its comorbidities to provide effective treatment options. Ferroptosis is a new form of cell death that is characterized by iron overload, lipid peroxide accumulation, and decreased glutathione peroxidase 4(GPX4) activity, and it involves the pathological processes of a variety of diseases. Lipid deposition caused by lipid diseases and iron overload is significant in metabolic syndrome, providing the theoretical conditions for developing ferroptosis. Recent studies have found that the major molecules of ferroptosis are linked to common metabolic syndrome consequences, such as T2DM and atherosclerosis. In this review, we first discussed the mechanics of ferroptosis, the regulatory function of inducers and inhibitors of ferroptosis, and the significance of iron loading in MetS. Next, we summarized the role of ferroptosis in the pathogenesis of MetS, such as obesity, type 2 diabetes, and atherosclerosis. Finally, we discussed relevant ferroptosis-targeted therapies and raised some crucial issues of concern to provide directions for future Mets-related treatments and research.

The Role of cGAS-STING Signalling in Metabolic Diseases: from Signalling Networks to Targeted Intervention

The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) is a crucial innate defence mechanism against viral infection in the innate immune system, as it principally induces the production of type I interferons. Immune responses and metabolic control are inextricably linked, and chronic low-grade inflammation promotes the development of metabolic diseases. The cGAS-STING pathway activated by double-stranded DNA (dsDNA), cyclic dinucleotides (CDNs), endoplasmic reticulum stress (ER stress), mitochondrial stress, and energy imbalance in metabolic cells and immune cells triggers proinflammatory responses and metabolic disorders. Abnormal overactivation of the pathway is closely associated with metabolic diseases such as obesity, nonalcoholic fatty liver disease (NAFLD), insulin resistance and cardiovascular diseases (CVDs). The interaction of cGAS-STING with other pathways, such as the nuclear factor-kappa B (NF-κB), Jun N-terminal kinase (JNK), AMP-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), autophagy, pyroptosis and insulin signalling pathways, is considered an important mechanism by which cGAS-STING regulates inflammation and metabolism. This review focuses on the link between immune responses related to the cGAS-STING pathway and metabolic diseases and cGAS-STING interaction with other pathways for mediating signal input and affecting output. Moreover, potential inhibitors of the cGAS-STING pathway and therapeutic prospects against metabolic diseases are discussed. This review provides a comprehensive perspective on the involvement of STING in immune-related metabolic diseases.

Research progress on drugs for diabetes based on insulin receptor/insulin receptor substrate

The number of people with diabetes worldwide is increasing annually, resulting in a serious economic burden. Insulin resistance is a major pathology in the early onset of diabetes mellitus, and therefore, related drug studies have attracted research attention. The insulin receptor/insulin receptor substrate (INSR/IRS) serves as the primary conduit in the insulin signal transduction cascade, and dysregulation of this pathway can lead to insulin resistance. Currently, there exist a plethora of hypoglycemic drugs in the market; however, drugs that specifically target INSR/IRS are comparatively limited. The literature was collected by direct access to the PubMed database, and was searched using the terms "diabetes mellitus; insulin resistance; insulin receptor; insulin receptor substrate; diabetes drug" as the main keywords for literature over the last decade. This article provides a comprehensive analysis of the structure and function of INSR and IRS proteins, as well as the drugs used for the treatment of diabetes. Additionally, it serves as a valuable reference for the advancement of novel therapeutic agents for diabetes management.

Binding mechanism and biological effects of flavone DYRK1A inhibitors for the design of new antidiabetics

The selective inhibition of kinases from the diabetic kinome is known to promote the regeneration of beta cells and provide an opportunity for the curative treatment of diabetes. The effect can be achieved by carefully tailoring the selectivity of inhibitor toward a particular kinase, especially DYRK1A, previously associated with Down syndrome and Alzheimer's disease. Recently DYRK1A inhibition has been shown to promote both insulin secretion and beta cells proliferation. Here, we show that commonly available flavones are effective inhibitors of DYRK1A. The observed biochemical activity of flavone compounds is confirmed by crystal structures solved at 2.06 Å and 2.32 Å resolution, deciphering the way inhibitors bind in the ATP-binding pocket of the kinase, which is driven by the arrangement of hydroxyl moieties. We also demonstrate antidiabetic properties of these biomolecules and prove that they could be further improved by therapy combined with TGF-β inhibitors. Our data will allow future structure-based optimization of the presented scaffolds toward potent, bioavailable and selective anti-diabetic drugs.

Hepatoprotective Effect of Morin Hydrate in Type 2 Diabetic Wistar Rats Exposed to Diesel Exhaust Particles

Studies have shown that exposure to air pollutants such as diesel exhaust particles (DEP) exacerbate diabetes complications. Morin hydrate (MH), a plant bioflavonoid, provides hepatoprotection due to its diverse pharmacological properties. This study examines the hepatoprotective effects of MH in Wistar rats with type 2 diabetes exposed to diesel exhaust (DE). Procured male Wistar rats (n = 60) were separated into 12 groups of five rat each. Type 2 diabetes was induced following oral therapy with fructose solution and one-time injection of 45 mg/kg of streptozotocin (STZ). The DEP extract was administered by nasal instillation, whereas MH was administered via oral gavage. Biochemical assays were used to determine the effect of MH on diabetic rats and DEP-exposed diabetic rats with respect to liver function indices (AST and ALT), liver antioxidants (SOD, CAT, Gpx, and GSH), lipid profile, and oxidative stress marker (conjugated diene and lipid peroxidation). The mRNA expression of PI3K/AKT/GLUT4 and AMPK/GLUT4 signaling pathways were quantified using RT-PCR. The results show that normal rats, diabetic rats, and diabetic rats exposed to DEP exhibited a substantial decrease in oxidative stress indicators, serum lipid profile, and levels of AST and ALP, as well as an increase in liver natural antioxidants following oral administration of MH. The gene expression study demonstrated that MH promotes the activation of the insulin signaling pathways which facilitates the uptake of glucose from the blood. This study suggests that MH offered hepatoprotection in type 2 diabetic rats and DEP exposed diabetic rats.

Ghrelin as a Biomarker of "Immunometabolic Depression" and Its Connection with Dysbiosis

Ghrelin, a gastrointestinal peptide, is an endogenous ligand of growth hormone secretagogue receptor 1a (GHSR1a), which is mainly produced by X/A-like cells in the intestinal mucosa. Beyond its initial description as a growth hormone (GH) secretagogue stimulator of appetite, ghrelin has been revealed to have a wide range of physiological effects, for example, the modulation of inflammation; the improvement of cardiac performance; the modulation of stress, anxiety, taste sensation, and reward-seeking behavior; and the regulation of glucose metabolism and thermogenesis. Ghrelin secretion is altered in depressive disorders and metabolic syndrome, which frequently co-occur, but it is still unknown how these modifications relate to the physiopathology of these disorders. This review highlights the increasing amount of research establishing the close relationship between ghrelin, nutrition, microbiota, and disorders such as depression and metabolic syndrome, and it evaluates the ghrelinergic system as a potential target for the development of effective pharmacotherapies.

Tirzepatide ameliorates spatial learning and memory impairment through modulation of aberrant insulin resistance and inflammation response in diabetic rats

Background: One of the typical symptoms of diabetes mellitus patients was memory impairment, which was followed by gradual cognitive deterioration and for which there is no efficient treatment. The anti-diabetic incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) were demonstrated to have highly neuroprotective benefits in animal models of AD. We wanted to find out how the GLP-1/GIP dual agonist tirzepatide affected diabetes's impairment of spatial learning memory. Methods: High fat diet and streptozotocin injection-induced diabetic rats were injected intraperitoneally with Tirzepatide (1.35 mg/kg) once a week. The protective effects were assessed using the Morris water maze test, immunofluorescence, and Western blot analysis. Golgi staining was adopted for quantified dendritic spines. Results: Tirzepatide significantly improved impaired glucose tolerance, fasting blood glucose level, and insulin level in diabetic rats. Then, tirzepatide dramatically alleviated spatial learning and memory impairment, inhibited Aβ accumulation, prevented structural damage, boosted the synthesis of synaptic proteins and increased dendritic spines formation in diabetic hippocampus. Furthermore, some aberrant changes in signal molecules concerning inflammation signaling pathways were normalized after tirzepatide treatment in diabetic rats. Finally, PI3K/Akt/GSK3β signaling pathway was restored by tirzepatide. Conclusion: Tirzepatide obviously exerts a protective effect against spatial learning and memory impairment, potentially through regulating abnormal insulin resistance and inflammatory responses.

β-Caryophyllene, a Dietary Phytocannabinoid, Alleviates Diabetic Cardiomyopathy in Mice by Inhibiting Oxidative Stress and Inflammation Activating Cannabinoid Type-2 Receptors

Diabetes mellitus (DM) and its associated complications are considered one of the major health risks globally. Among numerous complications, diabetic cardiomyopathy (DCM) is characterized by increased accumulation of lipids and reduced glucose utilization following abnormal lipid metabolism in the myocardium along with oxidative stress, myocardial fibrosis, and inflammation that eventually result in cardiac dysfunction. The abnormal metabolism of lipids plays a fundamental role in cardiac lipotoxicity following the occurrence and development of DCM. Recently, it has been revealed that cannabinoid type-2 (CB2) receptors, an essential component of the endocannabinoid system, play a crucial role in the pathogenesis of obesity, hyperlipidemia, and DM. Provided the role of CB2R in regulating the glucolipid metabolic dysfunction and its antioxidant as well as anti-inflammatory activities, we carried out the current study to investigate the protective effects of a selective CB2R agonist, β-caryophyllene (BCP), a natural dietary cannabinoid in the murine model of DCM and elucidated the underlying pharmacological and molecular mechanisms. Mice were fed a high-fat diet for 4 weeks followed by a single intraperitoneal injection of streptozotocin (100 mg/kg) to induce the model of DCM. BCP (50 mg/kg body weight) was given orally for 12 weeks. AM630, a CB2R antagonist, was given 30 min before BCP treatment to demonstrate the CB2R-dependent mechanism of BCP. DCM mice exhibited hyperglycemia, increased serum lactate dehydrogenase, impaired cardiac function, and hypertrophy. In addition, DCM mice showed alternations in serum lipids and increased oxidative stress concomitant to reduced antioxidant defenses and enhanced cardiac lipid accumulation in the diabetic heart. DCM mice also exhibited activation of TLR4/NF-κB/MAPK signaling and triggered the production of inflammatory cytokines and inflammatory enzyme mediators. However, treatment with BCP exerted remarkable protective effects by favorable modulation of the biochemical and molecular parameters, which were altered in DCM mice. Interestingly, pretreatment with AM630 abrogated the protective effects of BCP in DCM mice. Taken together, the findings of the present study demonstrate that BCP possesses the capability to mitigate the progression of DCM by inhibition of lipotoxicity-mediated cardiac oxidative stress and inflammation and favorable modulation of TLR4/NF-κB/MAPK signaling pathways mediating the CB2R-dependent mechanism.

Advanced glycation end product signaling and metabolic complications: Dietary approach

Advanced glycation end products (AGEs) are a heterogeneous collection of compounds formed during industrial processing and home cooking through a sequence of nonenzymatic glycation reactions. The modern western diet is full of heat-treated foods that contribute to AGE intake. Foods high in AGEs in the contemporary diet include processed cereal products. Due to industrialization and marketing strategies, restaurant meals are modified rather than being traditionally or conventionally cooked. Fried, grilled, baked, and boiled foods have the greatest AGE levels. Higher AGE-content foods include dry nuts, roasted walnuts, sunflower seeds, fried chicken, bacon, and beef. Animal proteins and processed plant foods contain furosine, acrylamide, heterocyclic amines, and 5-hydroxymethylfurfural. Furosine (2-furoil-methyl-lysine) is an amino acid found in cooked meat products and other processed foods. High concentrations of carboxymethyl-lysine, carboxyethyl-lysine, and methylglyoxal-O are found in heat-treated nonvegetarian foods, peanut butter, and cereal items. Increased plasma levels of AGEs, which are harmful chemicals that lead to age-related diseases and physiological aging, diabetes, and autoimmune/inflammatory rheumatic diseases such as systemic lupus erythematosus and rheumatoid arthritis. AGEs in the pathophysiology of metabolic diseases have been linked to individuals with diabetes mellitus who have peripheral nerves with high amounts of AGEs and diabetes has been linked to increased myelin glycation. Insulin resistance and hyperglycemia can impact numerous human tissues and organs, leading to long-term difficulties in a number of systems and organs, including the cardiovascular system. Plasma AGE levels are linked to all-cause mortality in individuals with diabetes who have fatal or nonfatal coronary artery disease, such as ventricular dysfunction. High levels of tissue AGEs are independently associated with cardiac systolic dysfunction in diabetic patients with heart failure compared with diabetic patients without heart failure. It is widely recognized that AGEs and oxidative stress play a key role in the cardiovascular complications of diabetes because they both influence and are impacted by oxidative stress. All chronic illnesses involve protein, lipid, or nucleic acid modifications including crosslinked and nondegradable aggregates known as AGEs. Endogenous AGE formation or dietary AGE uptake can result in additional protein modifications and stimulation of several inflammatory signaling pathways. Many of these systems, however, require additional explanation because they are not entirely obvious. This review summarizes the current evidence regarding dietary sources of AGEs and metabolism-related complications associated with AGEs.

A-80426 suppresses CFA-induced inflammatory pain by suppressing TRPV1 activity via NFκB and PI3K pathways in mice

OBJECTIVES

Pain is associated with many circumstances, including inflammatory reactions, which arise from modification of the features of signaling pathways. α2-adrenergic receptor antagonists are widely utilized in narcosis. Here, the authors focused on the narcotic effect of A-80426 (A8) on Complete Freund's Adjuvant (CFA) injections-triggered chronic inflammation pain in WT and TRPV1-/- mice and explored whether its antinociceptive impact was modulated via Transient Receptor Potential Vanilloid 1 (TRPV1).

METHOD

CFA with or without A8 was co-administered to the mice, which were categorized randomly into four groups: CFA, A8, control, and vehicle. Pain behaviors underwent evaluation through mechanical withdrawal threshold, abdominal withdrawal reflex, and thermal withdrawal latency of WT animals.

RESULTS

Quantitative polymerase chain reaction revealed that inflammation-promoting cytokines (IL-1β, IL-6, and TNF-α) were upregulated in Dorsal Root Ganglion (DRG) and Spinal Cord Dorsal Horn (SCDH) tissues of WT animals. A8 administration reduced the pain behaviors and production of pro-inflammatory cytokines; however, this effect was significantly reduced in TRPV1-/- mice. Further analysis showed that CFA treatment reduced the TRPV1 expression in WT mice and A8 administration increased its expression and activity. The co-administration of SB-705498, a TRPV1 blocker, did not influence the pain behaviors and inflammation cytokines in CFA WT mice; however, SB-705498 the effect of A8 in WT mice. In addition, the TRPV1 block decreased the NFκB and PI3K activation in the Dorsal Root Ganglia (DRG) and Spinal Cord Dorsal Horn (SCDH) tissues of WT mice.

CONCLUSIONS

Together, A8 exerted a narcotic impact on CFA-supplemented mice via the TRPV1-modulated NFκB and PI3K pathway.

Biochemical and functional characterization of skeletal muscle cells differentiated from tonsil-derived mesenchymal stem cells

INTRODUCTION/AIMS

Human tonsils are a readily accessible source of stem cells for the potential treatment of skeletal muscle disorders. We reported previously that tonsil-derived mesenchymal stem cells (TMSCs) can differentiate into skeletal muscle cells (SKMCs), which renders TMSCs promising candidates for cell therapy for skeletal muscle disorders. However, the functional properties of the myocytes differentiated from mesenchymal stem cells have not been clearly evaluated. In this study we investigated whether myocytes differentiated from TMSCs (skeletal muscle cells derived from tonsil mesenchymal stem cells [TMSC-SKMCs]) exhibit the functional characteristics of SKMCs.

METHODS

To test the insulin reactivity of TMSC-SKMCs, the expression of glucose transporter 4 (GLUT4) and phosphatidylinositol 3-kinase/Akt was analyzed after the cells were treated for 30 minutes with 100 nmol/L insulin in normal or high-glucose medium. We also examined whether these cells formed a neuromuscular junction (NMJ) when cocultured with motor neurons, and whether they were stimulated by electrical signals using whole-cell patch clamping.

RESULTS

Skeletal muscle cells derived from tonsil mesenchymal stem cells expressed SKMC markers, such as MYOD, MYH3, MYH8, TNNI1, and TTN, at high levels, and exhibited a multinucleated cell morphology and a myotube-like shape. The expression of the acetylcholine receptor and GLUT4 was confirmed in TMSC-SKMCs. In addition, these cells exhibited insulin-mediated glucose uptake, NMJ formation, and transient changes in cell membrane action potential, all of which are representative functions of human SKMCs.

DISCUSSION

Tonsil-derived mesenchymal stem cells can be functionally differentiated into SKMCs and may have potential for clinical application for the treatment of skeletal muscle disorders.

Molecular Mechanisms of the Anti-Inflammatory Effects of Epigallocatechin 3-Gallate (EGCG) in LPS-Activated BV-2 Microglia Cells

Chronic neuroinflammation is associated with many neurodegenerative diseases, such as Alzheimer's. Microglia are the brain's primary immune cells, and when activated, they release various proinflammatory cytokines. Several natural compounds with anti-inflammatory and antioxidant properties, such as epigallocatechin 3-gallate (EGCG), may provide a promising strategy for inflammation-related neurodegenerative diseases involving activated microglia cells. The objective of the current study was to examine the molecular targets underlying the anti-inflammatory effects of EGCG in activated microglia cells. BV-2 microglia cells were grown, stimulated, and treated with EGCG. Cytotoxicity and nitric oxide (NO) production were evaluated. Immunoassay, PCR array, and WES™ Technology were utilized to evaluate inflammatory, neuroprotective modulators as well as signaling pathways involved in the mechanistic action of neuroinflammation. Our findings showed that EGCG significantly inhibited proinflammatory mediator NO production in LPS-stimulated BV-2 microglia cells. In addition, ELISA analysis revealed that EGCG significantly decreases the release of proinflammatory cytokine IL-6 while it increases the release of TNF-α. PCR array analysis showed that EGCG downregulated MIF, CCL-2, and CSF2. It also upregulated IL-3, IL-11, and TNFS10. Furthermore, the analysis of inflammatory signaling pathways showed that EGCG significantly downregulated mRNA expression of mTOR, NF-κB2, STAT1, Akt3, CCL5, and SMAD3 while significantly upregulating the expression of mRNA of Ins2, Pld2, A20/TNFAIP3, and GAB1. Additionally, EGCG reduced the relative protein expression of NF-κB2, mTOR, and Akt3. These findings suggest that EGCG may be used for its anti-inflammatory effects to prevent neurodegenerative diseases.

Subcritical water extraction of Gracilaria chorda abbreviates lipid accumulation and obesity-induced inflammation

Obesity-induced inflammation is crucial in the pathogenesis of insulin resistance and type 2 diabetes. In this study, we investigated the effects of the Gracilaria chorda (GC) on lipid accumulation and obesity-induced inflammatory changes or glucose homeostasis in cell models (3T3-L1 adipocytes and RAW 264.7 macrophages). Samples of GC were extracted using solvents (water, methanol, and ethanol) and subcritical water (SW) at different temperatures (90, 150, and 210°C). The total phenolic content of GCSW extract at 210°C (GCSW210) showed the highest content compared to others, and GCSW210 highly inhibited lipid accumulation and significantly reduced gene expressions of peroxisome proliferatoractivated receptor-γ, CCAAT/enhancer-binding protein-α, sterol regulatory element-binding protein-1c, and fatty acid synthase in 3T3-L1 adipocytes. In addition, GCSW210 effectively downregulated the pro-inflammatory cytokine regulator pathways in RAW 264.7 macrophages, including mitogen-activated protein kinase, signal transducers and activators of transcription and nuclear factor-κB. In co-culture of 3T3-L1 adipocytes and RAW 264.7 macrophages, GCSW210 significantly reduced nitric oxide production and interleukin-6 levels, and improved glucose uptake with dose-dependent manner. These findings suggest that GCSW210 improves glucose metabolism by attenuating obesity-induced inflammation in adipocytes, which may be used as a possible treatment option for managing obesity and associated metabolic disorders.

The impact of the soluble epoxide hydrolase cascade on periodontal tissues

Periodontitis is a chronic inflammatory disease with complex pathogenesis. Uncontrolled inflammation is driven by the immune system in response to accumulation of oral biofilm that leads to alveolar bone loss, bleeding, increased periodontal probing depth with loss of attachment of the connective tissues to the tooth, and ultimately, tooth loss. Soluble epoxide hydrolase (sEH) is an enzyme that converts epoxy fatty acids (EpFAs) produced by cytochrome P450 (CYP450) to an inactive diol. It has been shown that EpFAs display important features to counteract an exaggerated inflammatory process. Based upon this observation, inhibitors of sEH have been developed and are being proposed as a strategy to regulate proinflammatory lipid mediator production and the chronicity of inflammation. This mini review focuses on the impact of sEH inhibition on periodontal tissues focusing on the mechanisms involved. The interaction between Specialized Pro-Resolving Mediators and sEH inhibition emerges as a significant mechanism of action of sEH inhibitors that was not formerly appreciated and provides new insights into the role SPMs may play in prevention and treatment of periodontitis.

Kinase Inhibitors Involved in the Regulation of Autophagy: Molecular Concepts and Clinical Implications

All cells and intracellular components are remodeled and recycled in order to replace the old and damaged cells. Autophagy is a process by which damaged, and unwanted cells are degraded in the lysosomes. There are three different types of autophagy: macroautophagy, microautophagy, and chaperone-mediated autophagy. Autophagy has an effect on adaptive and innate immunity, suppression of any tumour, and the elimination of various microbial pathogens. The process of autophagy has both positive and negative effects, and this pertains to any specific disease or its stage of progression. Autophagy involves various processes which are controlled by various signaling pathways, such as Jun N-terminal kinase, GSK3, ERK1, Leucine-rich repeat kinase 2, and PTEN-induced putative kinase 1 and parkin RBR E3. Protein kinases are also important for the regulation of autophagy as they regulate the process of autophagy either by activation or inhibition. The present review discusses the kinase catalyzed phosphorylated reactions, the kinase inhibitors, types of protein kinase inhibitors and their binding properties to protein kinase domains, the structures of active and inactive kinases, and the hydrophobic spine structures in active and inactive protein kinase domains. The intervention of autophagy by targeting specific kinases may form the mainstay of treatment of many diseases and lead the road to future drug discovery.

Incretin and insulin signaling as novel therapeutic targets for Alzheimer's and Parkinson's disease

Despite an ever-growing prevalence and increasing economic burden of Alzheimer's disease (AD) and Parkinson's disease (PD), recent advances in drug development have only resulted in minimally effective treatment. In AD, along with amyloid and tau phosphorylation, there is an associated increase in inflammation/glial activation, a decrease in synaptic function, an increase in astrocyte activation, and a state of insulin resistance. In PD, along with α-synuclein accumulation, there is associated inflammation, synaptic dysfunction, dopaminergic neuronal loss, and some data to suggest insulin resistance. Therapeutic strategies for neurodegenerative disorders have commonly targeted individual pathological processes. An effective treatment might require either utilization of multiple drugs which target the individual pathological processes which underlie the neurodegenerative disease or the use of a single agent which could influence multiple pathological processes. Insulin and incretins are compounds with multiple effects on neurodegenerative processes. Preclinical studies have demonstrated that GLP-1 receptor agonists reduce neuroinflammation, reduce tau phosphorylation, reduce amyloid deposition, increase synaptic function, and improve memory formation. Incretin mimetics may act through the restoration of insulin signaling pathways, inducing further neuroprotective effects. Currently, phase 2 and phase 3 trials are underway in AD and PD populations. Here, we provide a comprehensive review of the therapeutic potential of incretin mimetics and insulin in AD and PD.

Apolipoprotein A-IV reduced metabolic inflammation in white adipose tissue by inhibiting IKK and JNK signaling in adipocytes

Apolipoprotein A-IV (ApoA-IV) plays a role in satiation and serum lipid transport. In diet-induced obesity (DIO) C57BL/6J mice, ApoA-IV deficiency induced in ApoA-IV-/-knock-out (KO mice) resulted in increased bodyweight, insulin resistance (IR) and plasma free fatty acid (FFA), which was partially reversed by stable ApoA-IV-green fluorescent protein (KO-A4-GFP) transfection in KO mice. DIO KO mice exhibited increased M1 macrophages in epididymal white adipose tissue (eWAT) as well as in the blood. Based on RNA-sequencing analyses, cytokine-cytokine receptor interactions, T cell and B cell receptors, and especially IL-17 and TNF-α, were up-regulated in eWAT of DIO ApoA-IV KO compared with WT mice. Supplemented ApoA-IV suppressed lipopolysaccharide (LPS)-induced IKK and JNK phosphorylation in Raw264.7 macrophage cell culture assays. When the culture medium was supplemented to 3T3-L1 adipocytes they exhibited an increased sensitivity to insulin. ApoA-IV protects against obesity-associated metabolic inflammation mainly through suppression in M1 macrophages of eWAT, IL17-IKK and IL17-JNK activity.

Ginger Could Improve Gestational Diabetes by Targeting Genes Involved in Nutrient Metabolism, Oxidative Stress, Inflammation, and the WNT/β-Catenin/GSK3β Signaling Pathway

This study aimed to evaluate the effect in female rats of 6 weeks of ginger consumption on gestational diabetes by assessing glucose and lipid metabolism, oxidative damage, inflammation, and the WNT/β-catenin/glycogen synthase kinase-3 beta (GSK3β) signaling pathway. In this study, 40 adult female rats were divided into 4 equal groups as follows: pregnant rats, pregnant rats with diabetes, pregnant rats consuming ginger, and pregnant rats with diabetes consuming ginger. Induction of diabetes on day 0 of pregnancy was induced by streptozotocin (STZ) injection. Insulin, glucose, and lipid profiles as metabolic factors were measured along with the hepatic expression of glucose transporter type 4 (GLUT4), mechanistic target of rapamycin complex 1 (mTORc1), sterol regulatory element-binding protein-1c (SREBP-1c), peroxisome proliferator-activated receptor α (PPAR-α), β-catenin, GSK3β, PPAR-g, nuclear factor-κB (NF-kB), and nuclear factor erythroid 2-related factor 2 (Nrf2). The levels of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and oxidative parameters were measured in the liver. The level of metabolic factors was significantly impaired in diabetic pregnant rats compared to the control group. However, ginger improved these parameters in the diabetic pregnant—ginger group compared to the diabetic pregnant group. The hepatic expression of genes involved in metabolism, oxidative stress, inflammation, and the wingless and int-1 (WNT) signaling pathway was significantly impaired in diabetic pregnant rats, while ginger improved them in the hepatic tissue of diabetic pregnant rats. It can be concluded that ginger could improve gestational diabetes by genes involved in metabolism, the WNT signaling pathway, oxidative stress, and inflammation. These results suggest that ginger can be an adjunct drug during pregnancy as a metabolic modulator.

Annona muricata L. peel extract inhibits carbohydrate metabolizing enzymes and reduces pancreatic β-cells, inflammation, and apoptosis via upregulation of PI3K/AKT genes

BACKGROUND AND OBJECTIVE

Annona muricata L. peel has been recognized for many ethnobotanical uses, including diabetes management. However, limited detailed scientific information about its mechanism of antidiabetic activity exists. The objective of this study was to evaluate the anti-diabetic properties of an aqueous extract of A. muricata peel (AEAMP) and its mechanism of action on alloxan-induced diabetic rats.

METHODS

In vitro antidiabetic assays, such as α-amylase and α-glucosidase were analyzed on AEAMP. Alloxan monohydrate (150 mg/kg b.w) was used to induce diabetes in the rats. 150 mg/kg b.w positive control group doses of 6.67, 13.53, and 27.06 mg/kg were administered to 3 groups for twenty-one days. The positive control group was administered 30 mg/kg of metformin. The negative and normal control groups were administered distilled water. The fasting blood glucose, serum insulin, lipid profile, inflammatory cytokines, antioxidant markers, carbohydrate metabolizing enzymes, and liver glycogen were analyzed as well as PI3K/AKT and apoptotic markers PCNA and Bcl2 by RT-PCR.

RESULTS

AEAMP inhibited α-amylase and α-glucosidase enzymes more effectively than acarbose. AEAMP reduced FBG levels, HOMA-IR, G6P, F-1,6-BP, MDA, TG, TC, AI, CRI, IL-6, TNF-α, and NF-κB in diabetic rats. Furthermore, in diabetic rats, AEAMP improved serum insulin levels, HOMA-β, hexokinase, CAT, GST, and HDL-c. Liver PI3K, liver PCNA and pancreas PCNA were not significantly different in untreated diabetic rats when compared to normal rats suggesting alloxan induction of diabetes did not downregulate the mRNA expression of these genes. AEAMP significantly up-regulated expression of AKT and Bcl2 in the liver and pancreatic tissue. It is interesting that luteolin and resorcinol were among the constituents of AEAMP.

CONCLUSIONS

AEAMP can improve β-cell dysfunction by upregulating liver AKT and pancreatic PI3K and AKT genes, inhibiting carbohydrate metabolizing enzymes and preventing apoptosis by upregulating liver and pancreatic Bcl2. However, the potential limitation of this study is the unavailability of equipment and techniques for collecting more data for the study.

Skin Microhemodynamics and Mechanisms of Its Regulation in Type 2 Diabetes Mellitus

The review presents modern ideas about peripheral microhemodynamics, approaches to the ana-lysis of skin blood flow oscillations and their diagnostic significance. Disorders of skin microhemodynamics in type 2 diabetes mellitus (DM) and the possibility of their interpretation from the standpoint of external and internal interactions between systems of skin blood flow regulation, based on a comparison of couplings in normal and pathological conditions, including models of pathologies on animals, are considered. The factors and mechanisms of vasomotor regulation, among them receptors and signaling events in endothelial and smooth muscle cells considered as models of microvessels are discussed. Attention was drawn to the disturbance of Ca2+-dependent regulation of coupling between vascular cells and NO-dependent regulation of vasodilation in diabetes mellitus. The main mechanisms of insulin resistance in type 2 DM are considered to be a defect in the number of insulin receptors and impaired signal transduction from the receptor to phosphatidylinositol-3-kinase and downstream targets. Reactive oxygen species plays an important role in vascular dysfunction in hyperglycemia. It is assumed that the considered molecular and cellular mechanisms of microhemodynamics regulation are involved in the formation of skin blood flow oscillations. Parameters of skin blood microcirculation can be used as diagnostic and prognostic markers for assessing the state of the body.

Effect of Carica papaya on IRS-1/Akt Signaling Mechanisms in High-Fat-Diet-Streptozotocin-Induced Type 2 Diabetic Experimental Rats: A Mechanistic Approach

Despite rigorous endeavors, existing attempts to handle type 2 diabetes (T2DM) are still a long way off, as a substantial number of patients do not meet therapeutic targets. Insulin resistance in skeletal muscle is discerned as a forerunner in the pathogenesis of T2DM and can be detected years before its progress. Studies have revealed the antidiabetic properties of Carica papaya (C. papaya), but its molecular mechanism on insulin receptor substrate-1 (IRS-1)/Akt signaling mechanisms is not yet known. The present study aimed to evaluate the role of C. papaya on IRS1 and Akt in high-fat-diet-streptozotocin-induced type 2 diabetic rats and also to analyze the bioactive compounds of C. papaya against IRS-1 and Akt via in silico analysis. Ethanolic extract of the leaves of C. papaya (600 mg/kg of body weight) was given daily for 45 days postinduction of T2DM up to the end of the study. Gluconeogenic enzymes, glycolytic enzymes, gene expression, and immunohistochemical analysis of IRS-1 and Akt in skeletal muscle were evaluated. C. papaya treatment regulated the levels of gluconeogenic and glycolytic enzymes and the levels of IRS-1 and Akt in skeletal muscle of type 2 diabetic animals. In silico studies showed that trans-ferulic acid had the greatest hit rate against the protein targets IRS-1 and Akt. C. papaya restored the normoglycemic effect in diabetic skeletal muscle by accelerating the expression of IRS-1 and Akt.

A bioactive component of Portulaca Oleracea L., HM-chromanone, improves palmitate-induced insulin resistance by inhibiting mTOR/S6K1 through activation of the AMPK pathway in L6 skeletal muscle cells

Increased free fatty acid levels in the blood are common in obesity and cause insulin resistance associated with type 2 diabetes in the muscles. Previous studies have confirmed the antidiabetic and anti-obesity potential of (E)-5-hydroxy-7-methoxy-3-(2-hydroxybenzyl)-4-chromanone (HM-chromanone). However, it is unknown how HM-chromanone alleviates obesity-related insulin resistance in L6 skeletal muscle cells. Palmitate induced insulin resistance and reduced glucose uptake, whereas HM-chromanone significantly increased glucose uptake. In palmitate-treated L6 skeletal muscle cells, HM-chromanone stimulated liver kinase B1 (LKB1) and 5'-adenosine monophosphate-activated protein kinase (AMPK) phosphorylation. The AMPK inhibitor compound C, and the LKB1 inhibitor radicicol blocked the effects of HM-chromanone. Furthermore, HM-chromanone significantly inhibited mammalian target of rapamycin (mTOR) and ribosomal protein S6 kinase 1 (S6K1) activation, but there was no change in protein kinase C θ (PKC θ) expression. When pAMPK was inhibited with compound C, the effect of HM-chromanone on the inhibition of mTOR and S6K1 was significantly diminished. This indicates that HM-chromanone inhibits mTOR and S6K1 activation through pAMPK activation. Inhibition of mTOR and S6K1 by HM-chromanone significantly reduced IRS-1Ser307 and IRS-1Ser632 phosphorylation, leading to insulin resistance. This resulted in an increase in PM-GLUT4 (glucose transporter 4) expression, thereby stimulating glucose uptake in insulin-resistant muscle cells. HM-chromanone can improve palmitate-induced insulin resistance by inhibiting mTOR and S6K1 through activation of the AMPK pathway in L6 skeletal muscle cells. These results show the therapeutic potential of HM-chromanone for improving insulin resistance in type 2 diabetes.

Epigenetic Regulation of Obesity-Associated Type 2 Diabetes

Obesity is becoming more widespread, and epidemics of this condition are now considered present in all developed countries, leading to public health concerns. The dramatic increases in obesity, type 2 diabetes mellitus (T2DM), and related vascular difficulties are causing a public health crisis. Thus, it is imperative that these trends are curbed. Understanding the molecular underpinnings of these diseases is crucial to aiding in their detection or even management. Thus, understanding the mechanisms underlying the interactions between environment, lifestyle, and genetics is important for developing effective strategies for the management of obesity. The focus is on finding the vital role of epigenetic changes in the etiology of obesity. Genome and epigenome-wide approaches have revealed associations with T2DM. The epigenome indicates that there is a systematic link between genetic variants and environmental factors that put people at risk of obesity. The present review focuses on the epigenetic mechanism linked with obesity-associated T2DM. Although the utilization of epigenetic treatments has been discussed with reference to certain cancers, several challenges remain to be addressed for T2DM.

Drosophila as a Model Organism to Study Basic Mechanisms of Longevity

The spatio-temporal regulation of gene expression determines the fate and function of various cells and tissues and, as a consequence, the correct development and functioning of complex organisms. Certain mechanisms of gene activity regulation provide adequate cell responses to changes in environmental factors. Aside from gene expression disorders that lead to various pathologies, alterations of expression of particular genes were shown to significantly decrease or increase the lifespan in a wide range of organisms from yeast to human. Drosophila fruit fly is an ideal model system to explore mechanisms of longevity and aging due to low cost, easy handling and maintenance, large number of progeny per adult, short life cycle and lifespan, relatively low number of paralogous genes, high evolutionary conservation of epigenetic mechanisms and signalling pathways, and availability of a wide range of tools to modulate gene expression in vivo. Here, we focus on the organization of the evolutionarily conserved signaling pathways whose components significantly influence the aging process and on the interconnections of these pathways with gene expression regulation.