Structural Modification and Optimisation of Hyperoside Oriented to Inhibit TGF-ß-Induced EMT Activity in Alveolar Epithelial Cells.

Pulmonary fibrosis (PF) is a disease characterised by diffuse nonspecific alveolar inflammation with interstitial fibrosis, which clinically manifests as dyspnoea and a significant decline in lung function. Many studies have shown that the epithelial-mesenchymal transition (EMT) plays a pivotal role in the pathogenesis of pulmonary fibrosis. Based on our previous findings, hypericin (Hyp) can effectively inhibit the process of the EMT to attenuate lung fibrosis. Therefore, a series of hyperoside derivatives were synthesised via modifying the structure of hyperoside, and subsequently evaluated for A549 cytotoxicity. Among these, the pre-screening of eight derivatives inhibits the EMT. In this study, we evaluated the efficacy of Z6, the most promising hyperoside derivative, in reversing TGF-ß1-induced EMTs and inhibiting the EMT-associated migration of A549 cells. After the treatment of A549 cells with Z6 for 48 h, RT-qPCR and Western blot results showed that Z6 inhibited TGF-ß1-induced EMTs in epithelial cells by supressing morphological changes in A549 cells, up-regulating E-cadherin (p < 0.01, p < 0.001), and down-regulating Vimentin (p < 0.01, p < 0.001). This treatment significantly reduced the mobility of transforming growth factor ß1 (TGF-ß1)-stimulated cells (p < 0.001) as assessed by wound closure, while increasing the adhesion rate of A549 cells (p < 0.001). In conclusion, our results suggest that hyperoside derivatives, especially compound Z6, are promising as potential lead compounds for treating pulmonary fibrosis, and therefore deserve further investigation.

Exosomes and exosomal miRNAs: A new avenue for the future treatment of rheumatoid arthritis.

Rheumatoid arthritis is a chronic systemic autoimmune disease that involves mainly synovitis and joint injury and is one of the main causes of disability. The pathogenesis of rheumatoid arthritis is complicated, and the treatment cycle is long. The traditional methods of inhibiting inflammation and immunosuppression are no longer sufficient for treatment of the disease, so there is an urgent need to seek new treatments. The exocrine microenvironment is a kind of microvesicle with a lipid bilayer membrane structure that can be secreted by most cells in the body. This structure contains cell-specific proteins, lipids and nucleic acids that can transmit this information from one cell to another. To achieve cell-to-cell communication. Exocrine microRNAs can be contained in exocrine cells and can be selectively transferred to target receptor cells via exocrine signaling, thus regulating the physiological function of target cells. This article focuses on the pathological changes that occur during the development of rheumatoid arthritis and the biological regulation of exocrine and exocrine microRNAs in rheumatoid joints. Research on the roles of exocrine and exocrine microRNAs in regulating the inflammatory response, cell proliferation/apoptosis, autophagy, effects on fibroblast-like synoviocytes and immune regulation in rheumatoid arthritis was reviewed. In addition, the challenges faced by this new treatment are discussed.

Phillyrin ameliorates influenza a virus-induced pulmonary inflammation by antagonizing CXCR2 and inhibiting NLRP3 inflammasome activation.

Influenza is an acute viral respiratory illness with high morbidity rates worldwide. Excessive pulmonary inflammation is the main characteristic of lethal influenza A virus (IAV) infections. Therapeutic options for managing influenza are limited to vaccines and some antiviral medications. Phillyrin is one of the major bioactive components of the Chinese herbal medicine Forsythia suspensa, which has the functions of sterilization, heat clearing and detoxification. In this work, the effect and mechanism of phillyrin on H1N1 influenza (PR8)-induced pneumonia were investigated. We reported that phillyrin (15 mg/kg) treatment after viral challenge significantly improved the weight loss, ameliorated pulmonary inflammation and inhibited the accumulation of multiple cytokines and chemokines in bronchoalveolar lavage fluid on 7 days post infection (dpi). In vitro, phillyrin suppressed influenza viral replication (Matrixprotein and nucleoprotein messenger RNA level) and reduced influenza virus-induced cytopathic effect (CPE). Furthermore,chemokine receptor CXCR2 was confirmed to be markedly inhibited by phillyrin. Surface plasmon resonance results reveal that phillyrin exhibits binding affinity to CXCR2, having a binding affinity constant (KD) value of 1.858e-5 M, suggesting that CXCR2 is a potential therapeutic target for phillyrin. Moreover, phillyrin inhibited the mRNA and protein expression levels of Caspase1, ASC and NLRP3 in the lungs of mice with H1N1-induced pneumonia.This study reveals that phillyrin ameliorates IAV-induced pulmonary inflammation by antagonizing CXCR2 and inhibiting NLRP3 inflammasome activation partly.

The role of TRPV1 in RA pathogenesis: worthy of attention.

Transient receptor potential cation channel subfamily V member 1 (TRPV1) is a Ca2+permeable, non-selective cation channel that is found primarily in sensory nerve fibres. Previous studies focused on pain transmission. However, recent studies have found that the TRPV1 channel, in addition to being associated with pain, also plays a role in immune regulation and their dysregulation frequently affects the development of rheumatoid arthritis (RA). A thorough understanding of the mechanism will facilitate the design of new TRPV1-targeted drugs and improve the clinical efficacy of RA. Here, we provide an updated and comprehensive overview of how the TRPV1 channel intrinsically regulates neuronal and immune cells, and how alterations in the TRPV1 channel in synoviocytes or chondrocytes extrinsically affect angiogenesis and bone destruction. Rapid progress has been made in research targeting TRPV1 for the treatment of inflammatory arthritis, but there is still much-uncharted territory regarding the therapeutic role of RA. We present a strategy for targeting the TRPV1 channel in RA therapy, summarising the difficulties and promising advances in current research, with the aim of better understanding the role of the TRPV1 channel in RA pathology, which could accelerate the development of TRPV1-targeted modulators for the design and development of more effective RA therapies.

To explore the effect of kaempferol on non-small cell lung cancer based on network pharmacology and molecular docking.

Non-small cell lung cancer (NSCLC) is a common pathological type of lung cancer, which has a serious impact on human life, health, psychology and life. At present, chemotherapy, targeted therapy and other methods commonly used in clinic are prone to drug resistance and toxic side effects. Natural extracts of traditional Chinese medicine (TCM) have attracted wide attention in cancer treatment because of their small toxic and side effects. Kaempferol is a flavonoid from natural plants, which has been proved to have anticancer properties in many cancers such as lung cancer, but the exact molecular mechanism is still unclear. Therefore, on the basis of in vitro experiments, we used network pharmacology and molecular docking methods to study the potential mechanism of kaempferol in the treatment of non-small cell lung cancer. The target of kaempferol was obtained from the public database (PharmMapper, Swiss target prediction), and the target of non-small cell lung cancer was obtained from the disease database (Genecards and TTD). At the same time, we collected gene chips GSE32863 and GSE75037 in conjunction with GEO database to obtain differential genes. By drawing Venn diagram, we get the intersection target of kaempferol and NSCLC. Through enrichment analysis, PI3K/AKT is identified as the possible key signal pathway. PIK3R1, AKT1, EGFR and IGF1R were selected as key targets by topological analysis and molecular docking, and the four key genes were further verified by analyzing the gene and protein expression of key targets. These findings provide a direction for further research of kaempferol in the treatment of NSCLC.

The NLRP3 inflammasome is involved in resident intruder paradigm-induced aggressive behaviors in mice.

Background: Aggressive behaviors are one of the most important negative behaviors that seriously endangers human health. Also, the central para-inflammation of microglia triggered by stress can affect neurological function, plasticity, and behavior. NLRP3 integrates stress-related signals and is a key driver of this neural para-inflammation. However, it is unclear whether the NLRP3 inflammasome is implicated in the development of aggressive behaviors. Methods: First, aggressive behavior model mice were established using the resident intruder paradigm. Then, aggressive behaviors were determined with open-field tests (OFT), elevated plus-maze (EPM), and aggressive behavior tests (AT). Moreover, the expression of P2X7R and NLRP3 inflammasome complexes were assessed by immunofluorescence and Western blot. The levels of NLRP3 and inflammatory cytokines were evaluated using enzyme-linked immunosorbent assay (ELISA) kits. Finally, nerve plasticity damage was observed by immunofluorescence, transmission electron microscope, and BrdU staining. Results: Overall, the resident intruder paradigm induced aggressive behaviors, activated the hippocampal P2X7R and NLRP3 inflammasome, and promoted the release of proinflammatory cytokines IL-1ß in mice. Moreover, NLRP3 knockdown, administration of P2X7R antagonist (A804598), and IL-1ß blocker (IL-1Ra) prevented NLRP3 inflammasome-driven inflammatory responses and ameliorated resident intruder paradigm-induced aggressive behaviors. Also, the resident intruder paradigm promoted the activation of mouse microglia, damaging synapses in the hippocampus, and suppressing hippocampal regeneration in mice. Besides, NLRP3 knockdown, administration of A804598, and IL-1Ra inhibited the activation of microglia, improved synaptic damage, and restored hippocampal regeneration. Conclusion: The NLRP3 inflammasome-driven inflammatory response contributed to resident intruder paradigm-induced aggressive behavior, which might be related to neuroplasticity. Therefore, the NLRP3 inflammasome can be a potential target to treat aggressive behavior-related mental illnesses.

Role of Interleukin-22 in ulcerative colitis.

Ulcerative Colitis (UC) is a chronic disease, in the progression of which an immune overreaction may play an important role. IL-22 is a member of the IL-10 superfamily of cytokines and is pleiotropic in immune regulation and inflammatory responses. IL-22 can produce protective effects, promote wound healing and tissue regeneration, while it can also induce inflammatory reactions when it is chronically overexpressed. Extensive literatures reported that IL-22 played an essential role in the pathogenic development of UC. IL-22 participates in the whole disease process of UC involving signaling pathways, gene expression regulation, and intestinal flora imbalance, making IL-22 a possible candidate for the treatment of UC. In this paper, the latest knowledge to further elucidate the role of IL-22 in UC was summarized and analyzed.

Anxiolytic effect of YangshenDingzhi granules: Integrated network pharmacology and hippocampal metabolomics.

Anxiety disorder is one of the most common mental diseases. It is mainly characterized by a sudden, recurring but indescribable panic, fear, tension and/or anxiety. Yangshendingzhi granules (YSDZ) are widely used in the treatment of anxiety disorders, but its active ingredients and underlying mechanisms are not yet clear. This study integrates network pharmacology and metabolomics to investigate the potential mechanism of action of YSDZ in a rat model of anxiety. First, potential active ingredients and targets were screened by network pharmacology. Then, predictions were verified by molecular docking, molecular dynamics and western blotting. Metabolomics was used to identify differential metabolites and metabolic pathways. All results were integrated for a comprehensive analysis. Network pharmacology analysis found that Carotene, ß-sitosterol, quercetin, Stigmasterol, and kaempferol in YSDZ exert anxiolytic effects mainly by acting on IL1ß, GABRA1, PTGS1, ESR1, and TNF targets. Molecular docking results showed that all the affinities were lower than -5 kcal/mol, and the average affinities were -7.7764 kcal/mol. Molecular dynamics simulation results showed that RMSD was lower than 2.5 A, and the overall conformational changes of proteins were small, indicating that the small molecules formed stable complexes with proteins. The results of animal experiments showed that YSDZ exerts anxiolytic effects by regulating GABRA1 and TNF-α, ameliorating pathological damage in hippocampal CA1, and regulating metabolic pathways such as thiamine, cysteine and methionine metabolism, lysine biosynthesis and degradation. Altogether, we reveal multiple mechanisms through which YSDZ exerts its anti-anxiety effects, which may provide a reference for its clinical application and drug development.

Potential hepatoprotective effects of Cistanche deserticola Y.C. Ma: Integrated phytochemical analysis using UPLC-Q-TOF-MS/MS, target network analysis, and experimental assessment.

Cistanche deserticola Y.C. Ma (CD) possesses hepatoprotective activity, while the active ingredients and involved mechanisms have not been fully explored. The objective of this study was to investigate the chemical composition and hepatoprotective mechanisms of CD. We primarily used ultra-performance liquid chromatography with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) to identify the phenylethanoid glycoside (PhG) components of CD. Then, network analysis was used to correlate and predict the pharmacology of the identified active components of PhGs with hepatoprotection. Next, the mechanisms of the core components and targets of action were explored by cellular assays and toll-like receptor 4 (TLR4) target competition assays. Finally, its hepatoprotective effects were further validated in in vivo experiments. The results showed that a total of 34 PhGs were identified based on the UPLC-Q-TOF-MS/MS method. Echinacoside (ECH) was identified as the key ingredient, and TLR4 and nuclear factor-kappa B (NF-κB) were speculated as the core targets of the hepatoprotective effect of CD via network analysis. The cellular assays confirmed that PhGs had significant anti-inflammatory activity. In addition, the real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot indicated that ECH notably reduced the levels of interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α), as well as the mRNA expression of TLR4, TNF-α, and IL-6, and decreased the high expression of the TLR4 protein, which in turn downregulated the myeloid differentiation factor 88 (MyD88), p-P65 and TNF-α proteins in the inflammatory model. The target competition experiments suggested that ECH and LPS could competitively bind to the TLR4 receptor, thereby reducing the expression of TLR4 downstream proteins. The results of in vivo studies showed that ECH significantly ameliorated LPS-induced hepatic inflammatory infiltration and liver tissue damage and reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels in mice. Moreover, ECH remarkably inhibited the release of inflammatory factors such as TNF-α, IL-6, IL-1ß, and MCP-1 in the serum of mice, exerting the hepatoprotective effect by the TLR4/NF-κB signaling pathway. More importantly, ECH could act as a potential inhibitor of TLR4 and deserves further in-depth study. Our results could provide a basis for exploring the hepatoprotective properties of CD.

Oxidative Stress and 4-hydroxy-2-nonenal (4-HNE): Implications in the Pathogenesis and Treatment of Aging-related Diseases.

Oxidative stress plays an important role in the development of aging-related diseases by accelerating the lipid peroxidation of polyunsaturated fatty acids in the cell membrane, resulting in the production of aldehydes, such as malondialdehyde and 4-hydroxy-2-nonenal (4-HNE) and other toxic substances. The compound 4-HNE forms adducts with DNA or proteins, disrupting many cell signaling pathways including the regulation of apoptosis signal transduction pathways. The binding of proteins to 4-HNE (4-HNE-protein) acts as an important marker of lipid peroxidation, and its increasing concentration in brain tissues and fluids because of aging, ultimately gives rise to some hallmark disorders, such as neurodegenerative diseases (Alzheimer's and Parkinson's diseases), ophthalmic diseases (dry eye, macular degeneration), hearing loss, and cancer. This review aims to describe the physiological origin of 4-HNE, elucidate its toxicity in aging-related diseases, and discuss the detoxifying effect of aldehyde dehydrogenase and glutathione in 4-HNE-driven aging-related diseases.

Research progress of natural products for the treatment of ischemic stroke.

Stroke is a leading cause of death and disability world-widely. The incidence rate of stroke has been increasing due to the aging population and lifestyle changes. At present, the only drug approved by the US Food and Drug Administration (FDA) for the treatment of ischemic stroke is tissue plasminogen activator (t-PA), but its clinical application is greatly limited because of its narrow time window and bleeding risk. Natural products have a long history of being used in traditional medicine with good safety, making them an important resource for the development of new drugs. Indeed, some natural products can target a variety of pathophysiological processes related to stroke, including oxidative stress, inflammation and neuronal apoptosis. Therefore, the development of high-efficiency, low-toxicity, safe and cheap active substances from natural products is of great significance for improving the treatment alternatives of patients with stroke. This article reviews the neuroprotective effects of 33 natural compounds by searching recent related literature. Among them, puerarin, pinocembrin, quercetin, epigallocatechin-3-gallate (EGCG), and resveratrol have great potential in the clinical treatment of ischemic stroke. This review will provide a powerful reference for screening natural compounds with potential clinical application value in ischemic stroke or synthesizing new neuroprotective agents with natural compounds as lead compounds.

Targeting NLRP3 Inflammasome in Translational Treatment of Nervous System Diseases: An Update.

Neuroinflammatory response is the immune response mechanism of the innate immune system of the central nervous system. Both primary and secondary injury can activate neuroinflammatory response. Among them, the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome plays a key role in the inflammatory response of the central system. Inflammasome is a type of pattern recognition receptor, a cytoplasmic polyprotein complex composed of members of the Nod-like receptor (NLR) family and members of the pyrin and HIN domain (PYHIN) family, which can be affected by a variety of pathogen-related molecular patterns or damage-related molecular patterns are activated. As one of the research hotspots in the field of medical research in recent years, there are increasing researches on immune function abnormalities in the onset of neurological diseases such as depression, AD, ischemic brain injury and cerebral infarction, the NLRP3 inflammasome causes the activated caspase-1 to cleave pre-interleukin-1ß and pre-interleukin-18 into mature interleukin-1ß and interleukin-18, in turn, a large number of inflammatory factors are produced, which participate in the occurrence and development of the above-mentioned diseases. Targeted inhibition of the activation of inflammasomes can reduce the inflammatory response, promote the survival of nerve cells, and achieve neuroprotective effects. This article reviews NLRP3 inflammasome's role in neurological diseases and related regulatory mechanisms, which providing references for future research in this field.

CXCL8 chemokine in ulcerative colitis.

Ulcerative colitis (UC) is a major type of inflammatory bowel disease (IBD), which is characterized by diffuse inflammation of the mucosa of the colon and rectum. Abdominal pain, diarrhea, and hematochezia are UC's main clinical manifestations. Pathogenesis of UC has not yet been clearly elucidated, but it is considered to result from dysregulated expressions of molecules engaged in proinflammatory and anti-inflammatory processes. CXCL8 is one of the most important proinflammatory factors which play a vital role in many inflammatory diseases including UC. The CXCL8-CXCR1/2 axis participates in the pathogenesis of UC through multiple signaling pathways, including PI3k/Akt, MAPKs and NF-κB signaling pathways. Meanwhile, more and more studies in recent years have shown that UC patients have specific non-coding RNA (ncRNA) expression profiles, which may be involved in the occurrence and development of inflammation. In this article, we analyzed the CXCL8-CXCR1/2 axis related signaling pathways and ncRNAs in UC, as well as recent advances in our understanding of the CXCL8-CXCR1/2 axis inhibition as a therapeutic strategy against UC.

Levodopa affects spike and local field synchronisation in the pedunculopontine nucleus of a rat model of Parkinson's disease.

The pedunculopontine nucleus (PPN) undergoes significant anatomic and electrophysiological alterations in Parkinson's disease (PD), severely impacting locomotion. However, the effect of 6-hydroxydopamine (6-OHDA) lesion and levodopa (L-DOPA) therapy on the relationships between spike activities and local field potential (LFP) within the PPN is not well-understood. Synchronisation between the spike activity of individual neurones and LFP of neuronal ensembles is a crucial problem in the pathogenesis of PD. In this study, LFP signals and spikes in the PPN of rats in control, lesioned, and L-DOPA groups were recorded synchronously with a multi-unit electrical signal acquisition system and analysed for their coherence value, spike-field coherence, and phase-lock relationship. The spike-LFP relationship in the PPN was markedly increased in specific frequency bands because of the 6-OHDA lesion but differed depending on the animal locomotion state and neuronal type. L-DOPA had a limited therapeutic effect on the 6-OHDA-induced increase in the coherence value. Our study demonstrates that the PPN spike-LFP relationship is involved in the pathogenesis of PD and is critical for the effects of L-DOPA, providing a basis for the clinical treatment of refractory PD symptoms.

The Interaction of EphA4 With PDGFRß Regulates Proliferation and Neuronal Differentiation of Neural Progenitor Cells in vitro and Promotes Neurogenesis in vivo.

Neural progenitor cells (NPCs) have great potentials in cell replacement therapy for neurodegenerative diseases, such as Alzheimer's disease (AD), by promoting neurogenesis associated with hippocampal memory improvement. Ephrin receptors and angiogenic growth factor receptors have a marked impact on the proliferation and differentiation of NPCs. Although ephrin receptor A4 (EphA4) was shown to directly interact with platelet-derived growth factor receptor ß (PDGFRß), the functional effects of this interaction on neurogenesis in cultured NPCs and adult hippocampus have not yet been studied. Immunoprecipitation demonstrated that EphA4 directly interacted with PDGFRß in NPCs under ligand stimulation. Ephrin-A1 and PDGF-platelet-derived growth factor BB (BB) significantly increased proliferation and neuronal differentiation of NPCs, which was further augmented by combined treatment of Ephrin-A1 and PDGF-BB. We also found that ligand-dependent proliferation and neuronal differentiation were inhibited by the dominant-negative EphA4 mutant or a PDGFR inhibitor. Most importantly, injection of ephrin-A1 and/or PDGF-BB promoted hippocampal NPC proliferation in the APP/PS1 mouse model of AD, indicating that direct interaction of EphA4 with PDGFRß plays a functional role on neurogenesis in vivo. Finally, studies in NPCs showed that the EphA4/PDGFRß/FGFR1/FRS2α complex formed by ligand stimulation is involved in neurogenesis via ERK signaling. The present findings provided a novel insight into the functional role of direct interaction of EphA4 and PDGFRß in neurogenesis, implicating its potential use for treating neurodegenerative diseases.

Characterization of spontaneous hydrocephalus development in the young atherosclerosis-prone mice.

Little has been reported on whether abnormal lipid metabolism affects hydrocephalus, although congenital malformations and infectious diseases are major causal factors for hydrocephalus development. In a study on the pathogenesis of atherogenesis in mice, we unexpectedly discovered that hydrocephalus occurred in partial apolipoptotein E (apoE) and low-density lipoprotein receptor (LDLR) double-knockout (apoE/LDLR) mice fed either chow or a high-fat and high-cholesterol diet between the ages of 4 and 12 weeks. In the 12-week-old high-fat and high-cholesterol group, the incidence rate was as high as 15%. Transcription levels of transforming growth factor-ß1 (TGF-ß1), Smad3, Smad4, and Smad7 in the cortex of the hydrocephalic cerebrum were significant downregulated in 4-week-old mice, but were increased in the 8 and 12-week-old groups compared with that of age-matched nonhydrocephalic mice. The mRNA level of tissue inhibitor of metalloproteinases 1 was significantly increased, whereas matrix metalloproteinase-9 was lower in hydrocephalic mice of all ages. The translation level of TGF-ß1 increased in the hydrocephalic brains of 8 and 12-week-old mice. This study provides primary evidence for the connection between lipid metabolic disorder and hydrocephalus development. This may suggest that both hyperglyceridemia and hypercholesterolemia are harmful factors in hydrocephalus development because of adverse effects on TGF-ß1/Smad signaling in the brain.

Ascorbic acid promotes 3T3-L1 cells adipogenesis by attenuating ERK signaling to upregulate the collagen VI.

BACKGROUND: Type VI collagen is supposed to be a regulation factor in adipogenesis. This study aimed to assess the promoting effect of vitamin C (VC) on adipogenic differentiation of preadipocytes as well as its mechanism. METHODS: Five sets of different combinations of chemicals were used to inhibit synthesis of type I to VI collagens, blocking ERK1/2 phosphorylation during adipogenesis of 3T3-L1 preadipocytes. Furthermore, to explore whether collagen VI plays a critical role during adipogenesis, specific knockdown of collagen VI was performed by using RNA interference. The morphology and expression patterns of several target factors involved in adipogenesis were assessed at various time points. RESULTS: A reduction in ERK1/2 phosphorylation and an increase in collagen VI and adipogenic-specific factors, such as C/EBPß, PPARγ and C/EBPα, were observed after treating adipogenic 3T3-L1 cells with AA2P, a stable derivative of VC. Inhibition of collagen synthesis by ethyl-3, 4-dihydroxybenzoate (EDHB) or by specific knockdown of collagen VI by RNAi could promote ERK1/2 phosphorylation. The ERK1/2 phosphorylation in both cases could be attenuated by AA2P treatment. In addition, the inhibition of ERK1/2 phosphorylation by U0126, a highly selective inhibitor of both MEK1 and MEK2 and a type of MAPK/ERK kinase, up-regulated the expression of collagen VI, while it down-regulated the adipogenic-specific factors. CONCLUSION: AA2P could up-regulate the expression of collagen VI by attenuating ERK1/2 phosphorylation, further up-regulating adipocyte-specific factors, thus finally promoting the adipogenesis of 3T3-L1 preadipocytes.

Loss of the TNFα function inhibits Wnt/ß-catenin signaling, exacerbates obesity development in adolescent spontaneous obese mice.

Tumor necrosis factor alpha (TNFα) is an adipokine involved in the regulation of cell differentiation and lipid metabolism, but its specific role has not been clearly understood. We validated a hypothesis that loss of TNFα function would inhibit Wnt/ß-catenin signaling and accelerate adipogenesis in adolescent genetic obese mice. Epididymal white adipose tissues (eWAT) from TNFα deficient (TNFα(-/-)), leptin receptor deficient (db/db) and double gene mutant (db/db/TNFα(-/-), DT) male mice were used for comparative analysis of key molecules in Wnt/ß-catenin signaling and adipogenic markers by qRT-PCR and western blot techniques. Compared with TNFα(-/-) and WT mice of 28 days old, an obese trait was observed in both db/db and DT mice, while the latter showed more significant body weight gain and eWAT hypertrophy. The mRNA level of key molecules in Wnt/ß-catenin pathway was reduced in both obese groups, while the DT group was the lowest. Expression of adipocyte-specific genes was up-regulated during obese development in the two obese groups, while the DT group revealed more correlation than that of db/db group. At the protein level, a down regulation of Wnt10b and ß-catenin in obese eWAT showed similar tendency with that of mRNA level. Compared with the lean groups, the levels of adiponectin and PPARγ2 for the obese groups were down-regulated at 21-day-old age, while they were elevated at older age. Our results suggested that deficiency in TNFα inhibited Wnt/ß-catenin signaling of the obese eWAT and up-regulated expression of adipokines, and accelerated adipogenesis in genetic obese mice on a chow diet.