Anaphylatoxin C5a induces inflammation and reduces insulin sensitivity by activating TLR4/NF-kB/PI3K signaling pathway in 3T3-L1 adipocytes

Complement System and Adhesion Molecule Skirmishes in Fabry Disease: Insights into Pathogenesis and Disease Mechanisms

Fabry disease is a rare X-linked lysosomal storage disorder caused by mutations in the galactosidase alpha (GLA) gene, resulting in the accumulation of globotriaosylceramide (Gb3) and its deacetylated form, globotriaosylsphingosine (Lyso-Gb3) in various tissues and fluids throughout the body. This pathological accumulation triggers a cascade of processes involving immune dysregulation and complement system activation. Elevated levels of complement 3a (C3a), C5a, and their precursor C3 are observed in the plasma, serum, and tissues of patients with Fabry disease, correlating with significant endothelial cell abnormalities and vascular dysfunction. This review elucidates how the complement system, particularly through the activation of C3a and C5a, exacerbates disease pathology. The activation of these pathways leads to the upregulation of adhesion molecules, including vascular cell adhesion molecule 1 (VCAM1), intercellular adhesion molecule 1 (ICAM1), platelet and endothelial cell adhesion molecule 1 (PECAM1), and complement receptor 3 (CR3) on leukocytes and endothelial cells. This upregulation promotes the excessive recruitment of leukocytes, which in turn exacerbates disease pathology. Targeting complement components C3a, C5a, or their respective receptors, C3aR (C3a receptor) and C5aR1 (C5a receptor 1), could potentially reduce inflammation, mitigate tissue damage, and improve clinical outcomes for individuals with Fabry disease.

Proteomics and Microbiota Conjoint Analysis in the Nasal Mucus: Revelation of Differences in Immunological Function in Manis javanica and Manis pentadactyla

All eight pangolin species, especially captive Manis pentadactyla, are critically endangered and susceptible to various pathogenic microorganisms, causing mass mortality. They are involved in the complement system, iron transport system, and inflammatory factors. M. pentadactyla exhibited a higher abundance of opportunistic pathogens, Moraxella, which potentially evaded complement-mediated immune response by reducing C5 levels and counteracting detrimental effects through transferrin neutralization. In addition, we found that the major structure of C5a, an important inflammatory factor, was lacking in M. javanica. In brief, this study revealed the differences in immune factors and microbiome between M. javanica and M. pentadactyla, thus providing a theoretical basis for subsequent immunotherapy.

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.

The C5aR1 complement receptor: A novel immunomodulator of insulin action in skeletal muscle

The complement system constitutes an integral component of the innate immune system and plays a critical role in adaptive immunity. Activation of this system engenders the production of complement peptide fragments, including C5a, which engage G-protein coupled receptors predominantly expressed in immune-associated cells, such as neutrophils, initiating pro-inflammatory responses. Intriguingly, our investigation has unveiled the presence of C5a receptor 1 (C5aR1) expression within skeletal muscle, a key metabolic tissue and primary target of insulin. Herein, we demonstrate that C5aR1 activation by C5a in differentiated human skeletal muscle cells elicits acute suppression of insulin signalling. This suppression manifests as impaired insulin-dependent association between IRS1 and the p85 subunit of PI3-kinase, a 50% reduction in Akt phosphorylation, and a 60% decline in insulin-stimulated glucose uptake. This impairment in insulin signalling is associated with a three-fold elevation in intramyocellular diacylglycerol (DAG) levels and a two-fold increase in cytosolic calcium content, which promote PKC-mediated IRS1 inhibition via enhanced phosphorylation at IRS1 Ser1101. Significantly, our findings demonstrate that structurally diverse C5aR1 antagonists, along with genetic deletion or stable silencing of C5aR1 by 80% using short-hairpin RNA, effectively attenuate repression of insulin signalling by C5a in LHCN-M2 human skeletal myotubes. These results underscore the potential of heightened C5aR1 activation, characteristic of obesity and chronic inflammatory conditions, to detrimentally impact insulin function within skeletal muscle cells. Additionally, the study suggests that agents targeting the C5a-C5aR axis, originally devised for mitigating complement-dependent inflammatory conditions, may offer therapeutic avenues to ameliorate immune-driven insulin resistance in key peripheral metabolic tissues, including skeletal muscle.

The anaphylatoxin C5a: Structure, function, signaling, physiology, disease, and therapeutics

The complement system is one of the oldest known tightly regulated host defense systems evolved for efficiently functioning cell-based immune systems and antibodies. Essentially, the complement system acts as a pivot between the innate and adaptive arms of the immune system. The complement system collectively represents a cocktail of ∼50 cell-bound/soluble glycoproteins directly involved in controlling infection and inflammation. Activation of the complement cascade generates complement fragments like C3a, C4a, and C5a as anaphylatoxins. C5a is the most potent proinflammatory anaphylatoxin, which is involved in inflammatory signaling in a myriad of tissues. This review provides a comprehensive overview of human C5a in the context of its structure and signaling under several pathophysiological conditions, including the current and future therapeutic applications targeting C5a.

Targeting PI3K/AKT signaling pathway in obesity

Obesity is a disorder with an increasing prevalence, which impairs the life quality of patients and intensifies societal health care costs. The development of safe and innovative prevention strategies and therapeutic approaches is thus of great importance. The complex pathophysiology of obesity involves multiple signaling pathways that influence energy metabolism in different tissues. The phosphatidylinositol 3-kinases (PI3K)/protein kinase B (AKT) pathway is critical for the metabolic homeostasis and its function in insulin-sensitive tissues is described in the context of health, obesity and obesity-related complications. The PI3K family participates in the regulation of diverse physiological processes including but not limited to cell growth, survival, differentiation, autophagy, chemotaxis, and metabolism depending on the cellular context. AKT is downstream of PI3K in the insulin signaling pathway, and promotes multiple cellular processes by targeting a plethora of regulatory proteins that control glucose and lipid metabolism. Natural products are essential for prevention and treatment of many human diseases, including obesity. Anti-obesity natural compounds effect multiple pathophysiological mechanisms involved in obesity development. Numerous recent preclinical studies reveal the advances in using plant secondary metabolites to target the PI3K/AKT signaling pathway for obesity management. In this paper the druggability of PI3K as a target for compounds with anti-obesity potential is evaluated. Perspectives on the strategies and limitations for clinical implementation of obesity management using natural compounds modulating the PI3K/AKT pathway are suggested.

Bear bile powder ameliorates type 2 diabetes via modulation of metabolic profiles, gut microbiota, and metabolites

Introduction: Bear bile powder (BBP) is widely used in the clinic and has a hypoglycemic effect, but its mechanism is not clear. Methods: In this study, type 2 diabetes mellitus (T2DM) rats induced by a high-sugar and high-fat diet combined with streptozotocin were given BBP, and biochemical indexes, pathological sections, metabonomics, intestinal microbiota (IM) and short-chain fatty acids (SCFAs) were determined. Results: The results showed that BBP could reduce blood glucose, relieve inflammation, insulin resistance, and lipid metabolism disorder, and alleviate tissue damage of the liver, spleen, kidney, and pancreas in T2DM rats. It is worth noting that BBP can reverse the changes in blood and urine metabolites in T2DM rats, which are mainly related to tryptophan metabolism, pentose and glucuronate interconversions, starch and sucrose metabolism, and glycerophospholipid metabolism. In addition, BBP restored IM disorder in T2DM rats, decreased the abundance of Allobaculum, Blautia, Dubosiella, and Anaerostipes, enriched the abundance of Lactobacillus, Romboutsia, UCG-005, and norank_f__Eggerthellaceae, and increased the concentration of SCFAs in intestinal contents. Discussion: These findings suggest that BBP may improve T2DM by regulating multiple metabolic pathways, IM composition, and SCFAs levels.

Thymoquinone-Mediated Modulation of Toll-like Receptors and Pluripotency Factors in Gingival Mesenchymal Stem/Progenitor Cells

Thymoquinone (TQ), the key active component of Nigella sativa (NS), demonstrates very promising biomedical anti-inflammatory, antioxidant, antimicrobial and anticancer properties. Several investigations have inspected the modulative activities of TQ on different stem/progenitor cell types, but its possible role in the regulation of gingival mesenchymal stem/progenitor cells (G-MSCs) has not yet been characterized. For the first time, this study investigates the effects of TQ on G-MSCs’ stemness and Toll-like receptor expression profiles. G-MSCs (n = 5) were isolated, sorted via anti-STRO-1 antibodies and then disseminated on cell culture dishes to create colony-forming units (CFUs), and their stem/progenitor cell attributes were characterized. TQ stimulation of the G-MSCs was performed, followed by an examination of the expression of pluripotency-related factors using RT-PCR and the expression profiles of TLRs 1−10 using flowcytometry, and they were compared to a non-stimulated control group. The G-MSCs presented all the predefined stem/progenitor cells’ features. The TQ-activated G-MSCs displayed significantly higher expressions of TLR3 and NANOG with a significantly reduced expression of TLR1 (p < 0.05, Wilcoxon signed-rank test). TQ-mediated stimulation preserves G-MSCs’ pluripotency and facilitates a cellular shift into an immunocompetent-differentiating phenotype through increased TLR3 expression. This characteristic modulation might impact the potential therapeutic applications of G-MSCs.

Adipose tissue: a neglected organ in the response to severe trauma?

Despite the manifold recent efforts to improve patient outcomes, trauma still is a clinical and socioeconomical issue of major relevance especially in younger people. The systemic immune reaction after severe injury is characterized by a strong pro- and anti-inflammatory response. Besides its functions as energy storage depot and organ-protective cushion, adipose tissue regulates vital processes via its secretion products. However, there is little awareness of the important role of adipose tissue in regulating the posttraumatic inflammatory response. In this review, we delineate the local and systemic role of adipose tissue in trauma and outline different aspects of adipose tissue as an immunologically active modifier of inflammation and as an immune target of injured remote organs after severe trauma.

SREBP2 promotes the viability, proliferation, and migration and inhibits apoptosis in TGF-β1-induced airway smooth muscle cells by regulating TLR2/NF-κB/NFATc1/ABCA1 regulatory network

Asthma is a respiratory disease with complex pathogenesis. Sterol-responsive element-binding proteins 2 (SREBP2) was found to bind to promoter sequences of ABCA1 to suppress ABCA1 promoter activity. This study aimed to explore the expression level of SREBP2 and ATP-binding cassette transporter A1 (ABCA1), and their effects on the development of airway smooth muscle cells (ASMCs) in asthma. ASMCs were treated with different concentrations of TGF-β1 (0, 0.5, 1, 5 and 10 ng/mL). Short hairpin SREBP2 (shSREBP2), SREBP2, shABCA1 or ABCA1 were transfected into ASMCs. Cell viability, proliferation, apoptosis, migration, and the expression of SREBP2, ABCA1 and related pathway proteins were detected by MTT assay, Brdu staining, flow cytometer, Transwell assay, qRT-PCR, and Western blotting, respectively. The results showed that TGF-β1 increased the viability, proliferation, migration and inhibited apoptosis in ASMCs. Moreover, TGF-β1 also decreased the expression of ABCA1, cleaved caspase-3, cleaved PARP, E-cadherin, and increased the expression of vimentin, TLR2, p-p65 and NFATc1. SREBP2 knockdown alleviated these TGF-β1-induced changes. SREBP2 overexpression inhibited ABCA1 expression and apoptosis, and promoted cell migration and the expression of TLR2, p-p65, NFATc1 in ASMCs. ABCA1 overexpression alleviated these SREBP2-induced promoting and inhibition effects. In conclusion, SREBP2 activates TLR2/NF-κB/NFATc1 regulatory network and promotes TGF-β1-induced cell movement through inhibiting ABCA1 expression.

Thrombospondin 2 Promotes IL-6 Production in Osteoarthritis Synovial Fibroblasts via the PI3K/AKT/NF-κB Pathway

Background

It is known that osteoarthritis (OA) pathogenesis involves inflammation that drives pathologic changes and that the matricellular protein, thrombospondin-2 (TSP2), is involved in angiogenesis, carcinogenesis, and inflammation. However, how TSP2 contributes to OA inflammatory processes is unclear.

Objective

The aim of current study was to elucidate whether TSP2 could promote interleukin-6 (IL-6), a pro-inflammatory cytokine, expression in osteoarthritis synovial fibroblasts (OASFs).

Methods

The synovial fibroblasts isolated from osteoarthritis and healthy donors were incubated with recombinant TSP2 to evaluate its effect in OA pathogenesis. The SFs were incubated with recombinant TSP2, followed by determining the IL-6 expression by qPCR and Western blot. After SFs were incubated with TSP2 for different time interval, the Western blot was performed to investigate the activation of signal pathway. The different strategies including neutralizing antibodies, siRNAs, and chemical inhibitors were used to discover the signal transduction in response to TSP2 incubation in OASFs. To evaluate the therapeutic potential of TSP2 in osteoarthritis, the anterior cruciate ligament transection (ACLT) in SD rats was performed in the presence or absence of TSP neutralizing antibody treatment.

Results

Our investigations have revealed that TSP2 promoted IL-6 expression in OASFs in a dose-dependent manner, especially in 30 and 100 ng/mL concentration (p < 0.05). Using different strategies including neutralizing antibodies, siRNAs, and chemical inhibitors, all of which attenuated signal pathway components in OASFs, we found evidence for the involvement of integrin α_vβ₃, PI3K, Akt, and NF-κB in TSP2-mediated upregulation of IL-6 (p < 0.05). Finally, in the result of rat ACLT surgical model, we found that TSP2 neutralizing antibody had protective effects in cartilage destruction during OA progression.

Conclusion

Thrombospondin-2 palys an important role in osteoarthritis pathogenesis and provides an opportunity to deal with osteoarthritis.

C5aR1 Mediates the Progression of Inflammatory Responses in the Brain of Rats in the Early Stage after Ischemia and Reperfusion

C5a receptor 1 (C5aR1) can induce a strong inflammatory response to an injury. Targeting C5aR1 has emerged as a novel anti-inflammatory therapeutic method. However, the role of C5aR1 in cerebral ischemia and reperfusion (I/R) injury and the definitive mechanism have not been elucidated clearly. Here, we determined whether C5aR1 signaling was essential to the post-ischemic inflammation and brain injury and whether it is a valid target for therapeutic blockade by using soluble receptor antagonist PMX53 in the early stage after I/R injury. In an in vitro model (oxygen and glucose deprivation and reperfusion, OGD/R) and in vivo model (middle cerebral artery occlusion and reperfusion, MCAO/R) of I/R, the neuronal cells of rats showed significantly up-regulated gene expression of C5aR1, and a notable inflammatory response was demonstrated with elevated tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6. Inhibition of C5aR1 by PMX53 treatment significantly reduced cell injury and inflammation and promoted brain function recovery. Further mechanism studies showed that inhibiting C5aR1 by PMX53 protected the rats from MCAO/R injury, decreased cell inflammation, and apoptosis via inhibiting the TLR4 and NF-κB signaling pathway and reducing the production of TNF-α, IL-1β, and IL-6 in MCAO/R rats. In addition, manipulation of the C5aR1 gene expression in vitro displayed that the inflammatory cascade signals including TLR4, TNF-α, IL-1β, and IL-6 were coincidently regulated with the regulation of C5aR1 expression levels. Thus, our results demonstrated a pathogenic role for C5aR1 in the progression of brain injury and inflammation response following I/R injury. Our study clearly demonstrated that C5aR1 inhibition might be an effective treatment strategy for ischemic stroke.

New targets of morphine postconditioning protection of the myocardium in ischemia/reperfusion injury: Involvement of HSP90/Akt and C5a/NF-κB

Background

Activation of the complement component 5a (C5a) and nuclear factor κB (NF-κB) signaling is an important feature of myocardial ischemia/reperfusion (I/R) injury and recent studies show that morphine postconditioning (MP) attenuates the myocardial injury. However, the mediating cardioprotective mechanisms remain unclear. The present study explores the role and interaction of heat shock protein 90 (HSP90), Akt, C5a, and NF-κB in MP-induced cardioprotection.

Methods

Male Sprague Dawley rats (n = 160) were randomized into eight groups (n = 20 per group). Rats in the sham group underwent thoracotomy, passing the ligature through the heart but without tying it (150 min), and the other seven groups were subjected to 30 min of anterior descending coronary artery occlusion followed by 2 h of reperfusion and the following treatments: I/R (30 min of ischemia and followed by 2 h of reperfusion); ischemic postconditioning (IPostC, 30 s of ischemia altered with 30 s of reperfusion, repeated for three cycles, and followed by reperfusion for 2 h); MP (0.3 mg/kg morphine administration 10 min before reperfusion); MP combined with the HSP90 inhibitor geldanamycin (GA, 1 mg/kg); MP combined with the Akt inhibitor GSK-690693 (GSK, 20 mg/kg); and MP combined with the C5a inhibitor PMX205 (PMX, 1 mg/kg/day, administration via drinking water for 28 days) and MP combined with the NF-κB inhibitor EVP4593 (QNZ, 1 mg/kg). All inhibitors were administered 10 min before morphine and followed by 2 h reperfusion.

Results

MP significantly reduced the I/R-induced infarct size, the apoptosis, and the release of cardiac troponin I, lactate dehydrogenase (LDH), and creatine kinase-MB. These beneficial effects were accompanied by increased expression of HSP90 and p-Akt, and decreased expression of C5a, NF-κB, tumor necrosis factor α, interleukin-1β, and intercellular cell adhesion molecule 1. However, HSP90 inhibitor GA or Akt inhibitor GSK increased the expression of C5a and NF-κB and prevented MP-induced cardioprotection. Furthermore, GA inhibited the MP-induced upregulation of p-Akt, while GSK did not affect HSP90, indicating that p-Akt acts downstream of HSP90 in MP-induced cardioprotection. In addition, C5a inhibitor PMX enhanced the MP-induced downregulation of NF-κB, while NF-κB inhibitor QNZ had no effect on C5a, indicating that the C5a/NF-κB signaling pathway is involved in MP-induced cardioprotection.

Conclusion

HSP90 is critical for MP-mediated cardioprotection possibly by promoting the phosphorylation of Akt and inhibiting the activation of C5a and NF-κB signaling and the subsequent myocardial inflammation, ultimately attenuating the infarct size and cardiomyocyte apoptosis.

HSP90-Mediates Liraglutide Preconditioning-Induced Cardioprotection by Inhibiting C5a and NF-κB

OBJECTIVE

We previously showed that HSP90 is involved in postconditioning cardioprotection by inhibiting complement C5a. Here, we investigated whether HSP90-mediated C5a/NF-κB inhibition is responsible for the cardioprotection conferred by liraglutide.

METHODS

Rat hearts underwent a 30 min occlusion of the anterior descending coronary artery, after which reperfusion was performed for 2 h. A total of 100 rats were randomly assigned to the following groups: ischemia/reperfusion (I/R), sham, liraglutide preconditioning (LP, liraglutide, 0.18 mg/kg, intravenously, 12 h before ischemia), HSP90 inhibitor geldanamycin (GA, 1 mg/kg, intraperitoneally, 30 min before ischemia) plus LP, and C5a receptor antagonist PMX53 (1 mg/kg, intravenously, 30 min before ischemia) plus LP. Cardiac injury, C5a/NF-κB activation, and inflammation were investigated.

RESULTS

LP significantly attenuated I/R-induced cardiomyocyte apoptosis, infarct size, and secretion of creatine kinase-MB, lactate dehydrogenase and cardiac troponin I. These effects were complemented by decreased C5a levels, nuclear factor (NF)-κB signaling, inflammatory cytokine expression, and increased HSP90 levels. GA, an HSP90 inhibitor, promotes C5a activation, NF-κB signaling, and inflammation and suppresses cardioprotection by LP. By contrast, PMX53, a C5a inhibitor, suppressed C5a activation, NF-κB signaling, and inflammation, and enhanced cardioprotection by LP.

CONCLUSION

HSP90 markedly contributes to LP cardioprotection by inhibiting inflammatory responsesand C5a/NF-κB signaling , ultimately attenuating I/R-induced cardiomyocyte apoptosis by suppressing the proapoptotic factor Bax, and inducing the anti-apoptotic factor Bcl2.

Chemerin causes lipid metabolic imbalance and induces passive lipid accumulation in human hepatoma cell line via the receptor GPR1

AIMS

Chemerin is abundant in patients with high body mass index and metabolic syndrome possibly due to its activation in adipogenesis and glucose intolerance. It has reported that sera chemerin is positively associated with fatty liver with little known underlying mechanisms. Our aim is to study the role of chemerin in hepatic lipid metabolism.

MAIN METHODS

Oil Red O staining and TG quantitative assay were used to detect intracellular lipid accumulation. PCR, QPCR and western blot were applied to measure lipid metabolism-related genes, CMKLR1, GPR1 and inflammation marker genes. Luciferase reporter assay was employed to uncover the down-regulation of proximate promoter activities of CMKLR1 and GPR1 by SREBP1c. Antibody neutralization assay was used to address the effects of chemerin on hepatic lipid synthesis.

KEY FINDINGS

Over-expression of chemerin led to passive lipid accumulation, in human hepatoma cell line HepG2. The disable form of chemerin (chemerin 21-158) and active chemerin (chemerin 21-157) performed strongly effects on lipid metabolism in HepG2 cells. Heterologous expression of CMKLR1 or G-protein coupled receptor1 (GPR1) played similar roles in hepatocyte lipid metabolism as chemerin. Chemerin exerted its effects on lipid metabolism via GPR1 in HepG2 cells. Furthermore, free fatty acids and high concentration insulin inhibited chemerin expression. Consistently, the key lipogenic transcription factor Sterol regulatory element binding protein 1c suppressed chemerin mRNA expression and proximate promoter activities of CMKLR1 and GPR1.

SIGNIFICANCE

It implied the existence of negative feed-back regulation and further confirmed the involvement of chemerin in hepatic lipid metabolism.

Chinese herbal medicine mixture 919 syrup alleviates nonalcoholic fatty liver disease in rats by inhibiting the NF-κB pathway

BACKGROUND

In many countries, nonalcoholic fatty liver disease (NAFLD) has risen to be the leading cause of liver disease, seriously threatening public health, while effective medical treatments are currently limited. 919 syrup (919 T J) is a Chinese herbal medicine, and both clinical and experimental studies have revealed that it can improve liver function.

OBJECTIVE

To study whether 919 T J shows a protective effect in a NAFLD rat model and explore its underlying mechanism, with a focus on the NF-κB pathway.

METHODS

Rats were randomly divided into three groups, including a control group, NAFLD group, and 919 T J group (n = 10 each). The control group received a standard diet, and the other two groups were fed a high-fat diet to establish the NAFLD model. From week 10, rats in the 919 T J group were intragastrically administered 919 T J for 4 weeks, and the NAFLD group was administered the same amount of saline. All rats were anesthetized at the beginning of week 14 to collect blood and liver specimens. Serum lipid levels, serum biochemical markers of liver function, and the gene expression levels of IL-1β, TNF-α, CXCL6, CXCR1, SREBP-1c, PPARγ, and NF-κB in the liver were measured. Oil Red O and hematoxylin and eosin staining of the liver was performed to observe pathological changes in the liver.

RESULTS

Significant abnormalities in serum lipid levels and serum biochemical markers of liver function were found in the NAFLD group relative to those in the control group. In addition, serious abnormalities were noted in the expression levels of liver inflammatory factors and lipid metabolism-related genes. Treatment of NAFLD rats with 919 T J reduced body weight and food intake and ameliorated the abnormal blood lipid levels and liver function markers. By regulating the NF-κB pathway, 919 T J downregulated the NF-κB-related proinflammatory signals, ameliorating the expression of inflammatory (IL-1β, TNF-α, CXCL6, and CXCR1) and lipid metabolism-related (SREBP-1c) factors in the liver and improving the NAFLD-induced pathological changes in the liver.

CONCLUSION

919 T J reduces the liver injury, steatosis, and inflammation caused by NAFLD, thus reversing the disease process.

Methane-Rich Saline Counteracts Cholestasis-Induced Liver Damage via Regulating the TLR4/NF-κB/NLRP3 Inflammasome Pathway

Cholestatic liver injury, due to obstruction of the biliary tract or genetic defects, is often accompanied by progressive inflammation and liver fibrosis. Methane-rich saline (MRS) has anti-inflammatory properties. However, whether MRS can provide protective effect in cholestatic liver injury is still unclear. In this study, Sprague-Dawley rats received bile duct ligation (BDL) to generate a cholestatic model followed by MRS treatment (10 mL/kg, ip treatment) every 12 h after the operation to explore the potential protective mechanism of MRS in cholestatic liver injury. We found that MRS effectively improved liver function, alleviated liver pathological damage, and localized infiltration of inflammatory cells. MRS treatment decreased the expression of hepatic fibrosis-associated proteins to alleviate liver fibrosis. Furthermore, MRS treatment suppressed the TLR4/NF-κB pathway and further reduced the levels of proinflammatory factors. Downregulation of NF-κB subsequently reduced the NLRP3 expression to inhibit pyroptosis. Our data indicated that methane treatment prevented cholestatic liver injury via anti-inflammatory properties that involved the TLR4/NF-κB/NLRP3 signaling pathway.

Impaired insulin signaling in the B10.D2-Hc0 H2d H2-T18c/oSnJ mouse model of complement factor 5 deficiency

Given the chemoattractant potential of complement factor 5 (C5) and its increased expression in adipose tissue (AT) of obese mice, we determined whether this protein of the innate immune system impacts insulin action. C5 control (C5cont) and spontaneously C5-deficient (C5def, B10.D2-Hc0 H2d H2-T18c/oSnJ) mice were placed on low- and high-fat diets to investigate their inflammatory and metabolic phenotypes. Adenoviral delivery was used to evaluate the effects of exogenous C5 on systemic metabolism. C5def mice gained less weight than controls while fed a high-fat diet, accompanied by reduced AT inflammation, liver mass, and liver triglyceride content. Despite these beneficial metabolic effects, C5def mice demonstrated severe glucose intolerance and systemic insulin resistance, as well as impaired insulin signaling in liver and AT. C5def mice also exhibited decreased expression of insulin receptor (INSR) gene and protein, as well as improper processing of pro-INSR. These changes were not due to the C5 deficiency alone as other C5-deficient models did not recapitulate the INSR processing defect; rather, in addition to the mutation in the C5 gene, whole genome sequencing revealed an intronic 31-bp deletion in the Insr gene in the B10.D2-Hc0 H2d H2-T18c/oSnJ model. Irrespective of the genetic defect, adenoviral delivery of C5 improved insulin sensitivity in both C5cont and C5def mice, indicating an insulin-sensitizing function of C5.

TLR4 gene in the regulation of periodontitis and its molecular mechanism

Regulatory effect of Toll-like receptor 4 (TLR4) gene on periodontitis in mice was investigated to explore its possible mechanism. Thirty C57/BL6 mice were randomly divided into the blank control group (N group, n=10), the periodontitis group (P group, n=10) and the periodontitis + TAK-242 group (PT group, n=10). The mice in P and PT group were ligatured with silk threads dipped with porphyromonas gingivalis (P. gingivalis) in the logarithmic phase to induce experimental periodontitis, and TAK-242 was intraperitoneally injected on the day when the periodontitis model was established. After fasting for 8 h, the expression levels of high-sensitivity C-reactive protein and inflammatory cytokines were measured in each group of mice. Their alveolar bones were isolated and changes were detected. Quantitative polymerase chain reaction was used to detect the expression levels of TLR4. After the mice were given TAK-242, the levels of hs-CPR, MCP-1, IL-6 and IL-1β in the PT group evidently increased (P<0.01) compared with those in the N group. After the mice were administered TAK-242, the alveolar bone density, the percentage of bone volume and the number of bone trabeculae in PT group were significantly reduced, and the bone trabecular space and structural model index were evidently decreased (P<0.01). In addition, the expression levels of and T-bet/GATA3 messenger ribonucleic acids (mRNAs) in peria of mice in the P group were significantly higher than those in the N group (P<0.01), whereas the expression level of Foxp3 mRNA was notably decreased (P<0.01). The involvement of TLR4 gene in the inflammatory response of periodontitis results in periodontitis, and its mechanism may be that it activates TLR4, so as to affect the expression of T-bet, GATA3 and Foxp3.

Common variants of genes encoding TLR4 and TLR4 pathway members TIRAP and IRAK1 are effective on MCP1, IL6, IL1β, and TNFα levels in type 2 diabetes and insulin resistance

OBJECTIVE AND DESIGN

Type 2 diabetes is a pandemic disease characterized by hyperglycemia, ineffective insulin use, and insulin resistance and affecting 1 in 11 people worldwide. Inflammation-related insulin resistance is thought to play an important role in the etiology of the disease. TLR4 is the central receptor of the natural immune system and has an important role as a trigger of the inflammatory response. The IRAK1 and TIRAP are members of the TLR4 pathway and involved in the TLR4-mediated inflammatory response. Genetic variants in the TLR4 gene or in the IRAK1 and TIRAP genes may have an important role in the development of insulin resistance and type 2 diabetes by disrupting the inflammatory response. In this direction, we aimed to investigate the relationship among TLR4 and IRAK1, TIRAP gene variants, and type 2 diabetes and insulin resistance, and investigate how these variants affect inflammatory factors (TNF-α, IL-6, MCP-1, and IL-1β).

SUBJECTS AND METHODS

In our study, a total of seven variations on the genes of TLR4 (rs4986790, rs4986791), IRAK1 (rs1059703, rs3027898, rs7061789), and TIRAP (rs8177374, rs8177400) were genotyped by the MassARRAY^® Iplex GOLD SNP genotyping in 100 type 2 diabetic patients and 100 non-diabetic individual. The TLR4 rs4986790 and rs4986791 variation was confirmed by PCR-RFLP method also. The serum IL1-β, IL6, MCP-1, and TNF-α levels were measured using enzyme-linked immunosorbent assay kits.

RESULTS AND CONCLUSION

As a result of our study, no correlation was found among TLR4, IRAK1, and TIRAP gene variants and the risk of type 2 diabetes and insulin resistance. However, TNF-α, IL-6, MCP-1, and IL-1β levels were also associated with diabetes and insulin resistance (p > 0.05). Although the gene variants were not significant in type 2 diabetes and insulin resistance groups, IRAK1, TLR4, and TIRAP gene variants were found to be associated with TNF-α, IL-6, MCP-1, and IL-1β levels.

Regulating glycolysis, the TLR4 signal pathway and expression of RBM3 in mouse liver in response to acute cold exposure

At low temperatures, the liver increases glucose utilization and expresses RNA-binding motif 3 (RBM3) to cope with cold exposure. In this study, the expression of heat shock protein 70 (HSP70), Toll-like receptor 4 (TLR4), bone marrow differentiation factor 88 (MYD88), and phosphorylated nuclear factor-κB (NF-κB) was consistent with fluctuations in insulin in fasted cold-exposed mice. We also found up-regulation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) in acute cold exposure with a decrease in core body temperature. RBM3 transcription and translation were activated 2 h after cold exposure. The anti-apoptotic factor Bcl-2/Bax ratio also increased, while expression of apoptosis factors: cleaved caspase-3, cleaved poly(ADP-ribose)polymerase 1 (PARP-1) and cytochrome-c (Cyt-c) was unchanged. Liver glycogen was depleted after 2 h of cold exposure, and blood glucose decreased after 4 h. Glycogen synthase kinase 3β (GSK3β) phosphorylation continued to increase to promote hepatic glycogen synthesis. We found a high level of protein kinase B (AKT) phosphorylation after 6 h of cold exposure. In addition, we demonstrated that after cold exposure for 2 h, in the liver, continued phosphorylation of fructose-2,6-diphosphate (PFKFB2) and decreased accumulation of glycogen intermediates fructose-1,6-diphosphate (FDP) and pyruvic acid (PA). In summary, the liver responds to cold exposure through a number of different pathways, including activation of HSP70/TLR4 signaling pathways, up-regulation of RBM3 expression, and increased glycolysis and glycogen synthesis. We propose a possible signaling pathway in which regulation of RBM3 expression by the liver affects the AKT metabolic signaling pathway. Lay summary In response to changes in ambient temperature, mice regulate global metabolism and gene expression through hormones. This study focused on the effects of environmental hypothermia on molecular pathways of glucose metabolism in the liver, which is the important metabolic organ in mice. This provides a basis for further study of mice against cold exposure damage.

TMT Based Proteomic Analysis of Human Follicular Fluid From Overweight/Obese and Normal-Weight Patients With Polycystic Ovary Syndrome

Background: Polycystic ovary syndrome (PCOS) is a major endocrine and metabolic disorder with heterogeneous manifestations and complex etiology. As a leading cause of anovulatory infertility, the molecular diversity of the follicular microenvironment has not been fully elucidated. The aim of the present study was to investigate the follicular fluid proteomic profiles of overweight/obese and normal-weight women with PCOS, to identify novel molecular mechanisms underlying PCOS and to determine the effect of obesity on the follicular fluid protein profiles. Methods: Follicular fluid samples were collected from 3 different groups: overweight/obese PCOS patients (n = 29), normal-weight PCOS patients (n = 29), and normo-ovulatory controls (n = 29). We used a quantitative approach with tandem mass tag labeling and liquid chromatography tandem mass spectrometry to identify the differentially expressed proteins. Differential abundance of four selected proteins was confirmed by ELISA. Gene Set Enrichment Analysis was also conducted to further explore our findings. Furthermore, we compared the clinical, hormonal, and biochemical characteristics of overweight/obese and normal-weight patients with PCOS to determine the effects of obesity. Results: A total of 1,153 proteins were identified, of which 41 and 19 proteins were differentially expressed in the overweight/obese PCOS group vs. the control group, and in the normal-weight PCOS group vs. the control group, respectively. Bioinformatics analyses showed that the inflammatory, immunological, and metabolic-related biological processes were co-enriched in both subgroups of PCOS. Apolipoprotein A-II, complement C5, fetuin-B, and stromal cell-derived factor 1 were found to be involved in various processes and were validated using the ELISA analysis. From clinical features and proteomic data, obesity was found to worsen follicular development disturbances in PCOS. Conclusion: In this proteomic study, a panel of proteins were found differentially expressed in the follicular fluid of PCOS. Inflammatory, immunological, and metabolic abnormalities were identified inside the intra-follicular environment, which could be aggravated by obesity. The identified proteins were correlated with follicular growth and may be considered as candidate biomarkers as well as therapeutic targets of PCOS.

Anaphylatoxin Receptors C3aR and C5aR1 Are Important Factors That Influence the Impact of Ethanol on the Adipose Secretome

Background and aims: Chronic ethanol exposure results in inflammation in adipose tissue; this response is associated with activation of complement as well as the development of alcohol-related liver disease (ALD). Adipose communicates with other organs, including liver, via the release of soluble mediators, such as adipokines and cytokines, characterized as the "adipose secretome." Here we investigated the role of the anaphaylatoxin receptors C3aR and C5aR1 in the development of adipose tissue inflammation and regulation of the adipose secretome in murine ALD (mALD). Methods: Wild-type C57BL/6 (WT), C3aR ^-/-, and C5aR1 ^-/- mice were fed Lieber-DeCarli ethanol diet for 25 days (6% v/v, 32% kcal) or isocaloric control diets; indicators of inflammation and injury were assessed in gonadal adipose tissue. The adipose secretome was characterized in isolated adipocytes and stromal vascular cells. Results: Ethanol feeding increased the expression of adipokines, chemokines and leukocyte markers in gonadal adipose tissue from WT mice; C3aR ^-/- were partially protected while C5aR1 ^-/- mice were completely protected. In contrast, induction of CYP2E1 and accumulation of TUNEL-positive cells in adipose in response to ethanol feeding was independent of genotype. Bone marrow chimeras, generated with WT and C5aR1 ^-/- mice, revealed C5aR1 expression on non-myeloid cells, likely to be adipocytes, contributed to ethanol-induced adipose inflammation. Chronic ethanol feeding regulated both the quantity and distribution of adipokines secreted from adipocytes in a C5aR1-dependent mechanism. In WT mice, chronic ethanol feeding induced a predominant release of pro-inflammatory adipokines from adipocytes, while the adipose secretome from C5aR1 ^-/- mice was characterized by an anti-inflammatory/protective profile. Further, the cargo of adipocyte-derived extracellular vesicles (EVs) was distinct from the soluble secretome; in WT EVs, ethanol increased the abundance of pro-inflammatory mediators while EV cargo from C5aR1 ^-/- adipocytes contained a greater diversity and more robust expression of adipokines. Conclusions: C3aR and C5aR1 are potent regulators of ethanol-induced adipose inflammation in mALD. C5aR1 modulated the impact of chronic ethanol on the content of the adipose secretome, as well as influencing the cargo of an extensive array of adipokines from adipocyte-derived EVs. Taken together, our data demonstrate that C5aR1 contributes to ethanol-mediated changes in the adipose secretome, likely contributing to intra-organ injury in ALD.

Gypenosides reverses depressive behavior via inhibiting hippocampal neuroinflammation

Gypenosides, a saponins extract isolated from the Gynostemma pentaphyllum plant, produces neuroprotective effects in the brain. Our previous studies have shown that hippocampal glucocorticoid receptor (GR)-brain-derived neurotrophic factor (BDNF)-TrkB signaling was involved in the antidepressant-like effects of gypenosides. It remains unknown whether gypenosides could alleviate neuroinflammation in depressive-like animals. The aim of the present study was to address this issue in chronic unpredictable mild stress (CUMS). Gypenosides was administrated for four weeks, followed by sucrose preference test and tail suspension test, which were performed to evaluate the effects of gypenosides. The results showed that gypenosides reversed both the decreased sucrose preference and increased immobility time in CUMS mice. In addition, gypenosides also attenuated the increase of pro-inflammatory cytokine levels in the hippocampus of CUMS animals. Furthermore, the activation of NF-κB, as well as its upstream mediators IKKα and IKKβ were inhibited by gypenosides. Last but not the least, CUMS promoted the activation of microglia, while gypenosides suppressed it according to the reduced number of iba1 positive cells. In conclusion, this study demonstrates that gypenosides exhibits the antidepressant-like effects in mice, which may be mediated by the inhibition of microglia and NF-κB signaling in the hippocampus.