Cardiac-specific PFKFB3 overexpression prevents diabetic cardiomyopathy via enhancing OPA1 stabilization mediated by K6-linked ubiquitination.

Diabetic cardiomyopathy (DCM) is a prevalent complication of type 2 diabetes (T2D). 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) is a glycolysis regulator. However, the potential effects of PFKFB3 in the DCM remain unclear. In comparison to db/m mice, PFKFB3 levels decreased in the hearts of db/db mice. Cardiac-specific PFKFB3 overexpression inhibited myocardial oxidative stress and cardiomyocyte apoptosis, suppressed mitochondrial fragmentation, and partly restored mitochondrial function in db/db mice. Moreover, PFKFB3 overexpression stimulated glycolysis. Interestingly, based on the inhibition of glycolysis, PFKFB3 overexpression still suppressed oxidative stress and apoptosis of cardiomyocytes in vitro, which indicated that PFKFB3 overexpression could alleviate DCM independent of glycolysis. Using mass spectrometry combined with co-immunoprecipitation, we identified optic atrophy 1 (OPA1) interacting with PFKFB3. In db/db mice, the knockdown of OPA1 receded the effects of PFKFB3 overexpression in alleviating cardiac remodeling and dysfunction. Mechanistically, PFKFB3 stabilized OPA1 expression by promoting E3 ligase NEDD4L-mediated atypical K6-linked polyubiquitination and thus prevented the degradation of OPA1 by the proteasomal pathway. Our study indicates that PFKFB3/OPA1 could be potential therapeutic targets for DCM.

In Situ Quantitative Imaging of Plasma Membrane Stiffness in Live Cells Using a Genetically Encoded FRET Sensor.

Cell membrane stiffness is critical for cellular function, with cholesterol and sphingomyelin as pivot contributors. Current methods for measuring membrane stiffness are often invasive, ex situ, and slow in process, prompting the need for innovative techniques. Here, we present a fluorescence resonance energy transfer (FRET)-based protein sensor designed to address these challenges. The sensor consists of two fluorescent units targeting sphingomyelin and cholesterol, connected by a linker that responds to the proximity of these lipids. In rigid membranes, cholesterol and sphingomyelin are in close proximity, leading to an increased FRET signal. We utilized this sensor in combination with confocal microscopy to explore changes in plasma membrane stiffness under various conditions, including differences in osmotic pressure, the presence of reactive oxygen species (ROS) and variations in substrate stiffness. Furthermore, we explored the impact of SARS-CoV-2 on membrane stiffness and the distribution of ACE2 after attachment to the cell membrane. This tool offers substantial potential for future investigations in the field of mechanobiology.

11,12-EET suppressed LPS induced TF expression and thrombus formation by accelerating mRNA degradation rate via strengthening PI3K-Akt signaling pathway and inhibiting p38-TTP pathway.

Epoxyeicosatrienoic acids (EETs), which are synthesized from arachidonic acid by cytochrome P450 epoxygenases, function primarily as autocrine and paracrine effectors in the cardiovascular system. So far, most research has focused on the vasodilatory, anti-inflammatory, anti-apoptotic and mitogenic properties of EETs in the systemic circulation. However, whether EETs could suppress tissue factor (TF) expression and prevent thrombus formation remains unknown. Here we utilized in vivo and in vitro models to investigate the effects and underlying mechanisms of exogenously EETs on LPS induced TF expression and inferior vein cava ligation induced thrombosis. We observed that the thrombus formation rate and the size of the thrombus were greatly reduced in 11,12-EET treated mice，accompanied by decreased TF and inflammatory cytokines expression. Further in vitro studies showed that by enhancing p38 MAPK activation and subsequent tristetraprolin (TTP) phosphorylation, LPS strengthened the stability of TF mRNA and induced increased TF expression. However, by strengthening PI3K-dependent Akt phosphorylation, which acted as a negative regulator of p38-TTP signaling pathway，11,12-EET reduced LPS-induced TF expression in monocytes. In addition, 11,12-EET inhibited LPS-induced NF-κB nuclear translocation by activating the PI3K/Akt pathway. Further study indicated that the inhibitory effect of 11,12-EET on TF expression was mediated by antagonizing LPS-induced activation of thromboxane prostanoid receptor. In conclusion, our study demonstrated that 11,12-EET prevented thrombosis by reducing TF expression and targeting the CYP2J2 epoxygenase pathway may represent a novel approach to mitigate thrombosis related diseases.

Inhibition of soluble epoxide hydrolase alleviates insulin resistance and hypertension via downregulation of SGLT2 in the mouse kidney.

The epoxyeicosatrienoic acid (EET) exerts beneficial effects on insulin resistance and/or hypertension. EETs could be readily converted to less biological active diols by soluble epoxide hydrolase (sEH). However, whether sEH inhibition can ameliorate the comorbidities of insulin resistance and hypertension and the underlying mechanisms of this relationship are unclear. In this study, C57BL/6 mice were rendered hypertensive and insulin resistant through a high-fat and high-salt (HF-HS) diet. The sEH inhibitor, 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU), was used to treat mice (1 mg/kg/day) for 8 weeks, followed by analysis of metabolic parameters. The expression of sEH and the sodium-glucose cotransporter 2 (SGLT2) was markedly upregulated in the kidneys of mice fed an HF-HS diet. We found that TPPU administration increased kidney EET levels, improved insulin resistance, and reduced hypertension. Furthermore, TPPU treatment prevented upregulation of SGLT2 and the associated increased urine volume and the excretion of urine glucose and urine sodium. Importantly, TPPU alleviated renal inflammation. In vitro, human renal proximal tubule epithelial cells (HK-2 cells) were used to further investigate the underlying mechanism. We observed that 14,15-EET or sEH knockdown or inhibition prevented the upregulation of SGLT2 upon treatment with palmitic acid or NaCl by inhibiting the inhibitory kappa B kinase α/ß/NF-κB signaling pathway. In conclusion, sEH inhibition by TPPU alleviated insulin resistance and hypertension induced by an HF-HS diet in mice. The increased urine excretion of glucose and sodium was mediated by decreased renal SGLT2 expression because of inactivation of the inhibitory kappa B kinase α/ß/NF-κB-induced inflammatory response.

Inulin-type fructans change the gut microbiota and prevent the development of diabetic nephropathy.

Diabetic nephropathy (DN) is the most common cause of end-stage renal disease, and few treatment options that prevent the progressive loss of renal function are available. Studies have shown that dietary fiber intake improves kidney diseases and metabolism-related diseases, most likely through short-chain fatty acids (SCFAs). The present study aimed to examine the protective effects of inulin-type fructans (ITFs) on DN through 16 S rRNA gene sequencing, gas chromatographymass spectrometry (GCMS) analysis and fecal microbiota transplantation (FMT). The results showed that ITFs supplementation protected against kidney damage in db/db mice and regulated the composition of the gut microbiota. Antibiotic treatment and FMT experiments further demonstrated a key role of the gut microbiota in mediating the beneficial effects of ITFs. The ITFs treatment-induced changes in the gut microbiota led to an enrichment of SCFA-producing bacteria, especially the genera Akkermansia and Candidatus Saccharimonas, which increased the fecal and serum acetate concentrations. Subsequently, acetate supplementation improved glomerular damage and renal fibrosis by attenuating mitochondrial dysfunction and reducing toxic glucose metabolite levels. In conclusion, ITFs play a renoprotective role by modulating the gut microbiota and increasing acetate production. Furthermore, acetate mediates renal protection by regulating glucose metabolism, decreasing glycotoxic product levels and improving mitochondrial function.

Soluble epoxide hydrolase deletion attenuated nicotine-induced arterial stiffness via limiting the loss of SIRT1.

Arterial stiffness, a consequence of smoking, is an underlying risk factor of cardiovascular diseases. Epoxyeicosatrienoic acids (EETs), hydrolyzed by soluble epoxide hydrolase (sEH), have beneficial effects against vascular dysfunction. However, the role of sEH knockout in nicotine-induced arterial stiffness was not characterized. We hypothesized that sEH knockout could prevent nicotine-induced arterial stiffness. In the present study, Ephx2 (the gene encodes sEH enzyme) null (Ephx2-/-) mice and wild-type (WT) littermate mice were infused with or without nicotine and administered with or without nicotinamide [NAM, sirtuin-1 (SIRT1) inhibitor] simultaneously for 4 wk. Nicotine treatment increased sEH expression and activity in the aortas of WT mice. Nicotine infusion significantly induced vascular remodeling, arterial stiffness, and SIRT1 deactivation in WT mice, which was attenuated in Ephx2 knockout mice (Ephx2-/- mice) without NAM treatment. However, the arterial protective effects were gone in Ephx2-/- mice with NAM treatment. In vitro, 11,12-EET treatment attenuated nicotine-induced matrix metalloproteinase 2 (MMP2) upregulation via SIRT1-mediated yes-associated protein (YAP) deacetylation. In conclusion, sEH knockout attenuated nicotine-induced arterial stiffness and vascular remodeling via SIRT1-induced YAP deacetylation.NEW & NOTEWORTHY We presently show that sEH knockout repressed nicotine-induced arterial stiffness and extracellular matrix remodeling via SIRT1-induced YAP deacetylation, which highlights that sEH is a potential therapeutic target in smoking-induced arterial stiffness and vascular remodeling.

Human kallikrein overexpression alleviates cardiac aging by alternatively regulating macrophage polarization in aged rats.

Cardiac aging is characterized by myocardial hypertrophy, fibrosis, and diastolic dysfunction. Human kallikrein (hKLK1) protects against fibrosis in various pathogenic states. However, the effects of hKLK1 overexpression on cardiac aging-related fibrosis and the underlying mechanisms remain unknown. Moreover, the role of hKLK1 in regulating macrophage function leading to cardiac fibrosis has not been investigated. Thus, in this study, we determined the effects of hKLK1 on cardiac aging and explored the mechanisms through which hKLK1 regulated aging-related fibrosis. Echocardiographic measurements showed that aging caused significant alternations in cardiac morphology, hypertrophy, and fibrosis in rats, and hKLK1 overexpression protected against aging-induced cardiac dysfunction. Compared with wild-type hearts, the hKLK1 transgene decreased the expression of monocyte chemoattractant protein 1 and suppressed mitochondrial dysfunction and excess oxidative stress, leading to decreased recruitment and retention of alternatively activated (M2) macrophages and reduced secretion of profibrotic cytokines mediated by the TGF-ß1-Smad3 signaling pathway in hearts of aging rats. Furthermore, these cardioprotective effects of hKLK1 overexpression were associated with the Janus kinase-signal transducer and activator of transcription 3 signaling pathway. H2O2-induced senescence promoted the differentiation of RAW264.7 cells into M2-type cells induced by IL-4 treatment. Bradykinin treatment relieved the migratory capacity of macrophages induced by H2O2. Thus, hKLK1 overexpression reduced cardiac fibrosis and improved aging-related cardiac dysfunction through reduced shift of macrophages to M2 macrophages, indicating that hKLK1 may alleviate aging-related cardiac dysfunction.-Hu, D., Dong, R., Yang, Y., Chen, Z., Tang, Y., Fu, M., Wang, D. W., Xu, X., Tu, L. Human kallikrein overexpression alleviates cardiac aging by alternatively regulating macrophage polarization in aged rats.

Liver Kinase B1/AMP-Activated Protein Kinase Pathway Activation Attenuated the Progression of Endotoxemia in the Diabetic Mice.

BACKGROUND/AIMS: Sepsis is a common disease that continues to increase in prevalence worldwide, and diabetes mellitus may make the situation worse. This study was designed to determine the role of Liver Kinase B1 (LKB1)/adenosine monophosphate-activated protein kinase (AMPK) signaling pathway in diabetic mice complicated with systemic endotoxemia. METHODS: The effects of LKB1/AMPK signaling pathway activation on endotoxemia were investigated in streptozotocin induced diabetic mice (STZ-mice) and db/db diabetic mice. Primary peritoneal macrophages and human umbilical vein endothelial cells (HUVECs) monolayers were simultaneously stimulated by both high glucose and LPS and used as a model to investigate the potential molecular mechanisms in vitro. RESULTS: After treatment with LPS, high glucose or both LPS and high glucose, phosphor-AMPK expression was decreased, and moreover, AMPK activation by metformin treatment alleviated the decrease in phosphor-AMPK expression in HUVECs and macrophages as well as in lung tissue. Furthermore, both LPS and high glucose co-treatment decreased LKB1 and phosphor-AMPK expression via enhanced oxidative stress response, and importantly, LKB1 overexpression mediated by adenovirus inhibited the decrease in phosphor-AMPK expression in macrophages and HUVECs. AMPK activation by metformin administration improved the survival of STZ-induced diabetic mice and db/db diabetic mice, which was associated with reduced lung endothelial hyperpermeability and systemic inflammatory response. Furthermore, the permeability of HUVECs monolayers induced by both high glucose and LPS stimulation was also alleviated by AMPK activation, which was partly via suppression of VE-cadherin phosphorylation. CONCLUSION: These data demonstrated that LKB1/AMPK signaling pathway activation improved the survival of diabetic mice complicated with endotoxemia. Thus, LKB1/AMPK signaling pathway may serve as a potentially useful therapeutic target for severe infection in diabetic patients.

Exogenous Bradykinin Inhibits Tissue Factor Induction and Deep Vein Thrombosis via Activating the eNOS/Phosphoinositide 3-Kinase/Akt Signaling Pathway.

BACKGROUND/AIMS: Bradykinin has been shown to exert a variety of protective effects against vascular injury, and to reduce the levels of several factors involved in the coagulation cascade. A key determinant of thrombin generation is tissue factor (TF). However, whether bradykinin can regulate TF expression remains to be investigated. METHODS: To study the effect of bradykinin on TF expression, we used Lipopolysaccharides (LPS) to induce TF expression in human umbilical vein endothelial cells and monocytes. Transcript levels were determined by RT-PCR, protein abundance by Western blotting. In the in vivo study, bradykinin and equal saline were intraperitoneally injected into mice for three days ahead of inferior cava vein ligation that we took to induce thrombus formation, after which bradykinin and saline were injected for another two days. Eventually, the mice were sacrificed and tissues were harvested for tests. RESULTS: Exogenous bradykinin markedly inhibited TF expression in mRNA and protein level induced by LPS in a dose-dependent manner. Moreover, the NO synthase antagonist L-NAME and PI3K inhibitor LY294002 dramatically abolished the inhibitory effects of bradykinin on tissue factor expression. PI3K/Akt signaling pathway activation induced by bradykinin administration reduced the activity of GSK-3ß and MAPK, and reduced NF-x03BA;B level in the nucleus, thereby inhibiting TF expression. Consistent with this, intraperitoneal injection of C57/BL6 mice with bradykinin also inhibited the thrombus formation induced by ligation of inferior vena cava. CONCLUSION: Bradykinin suppressed TF protein expression in human umbilical vein endothelial cells and monocytes in vitro; in line with this, it inhibits thrombus formation induced by ligation of inferior vena cava in vivo.

Cardiomyocyte specific expression of Acyl-coA thioesterase 1 attenuates sepsis induced cardiac dysfunction and mortality.

Compromised cardiac fatty acid oxidation (FAO) induced energy deprivation is a critical cause of cardiac dysfunction in sepsis. Acyl-CoA thioesterase 1 (ACOT1) is involved in regulating cardiac energy production via altering substrate metabolism. This study aims to clarify whether ACOT1 has a potency to ameliorate septic myocardial dysfunction via enhancing cardiac FAO. Transgenic mice with cardiomyocyte specific expression of ACOT1 (αMHC-ACOT1) and their wild type (WT) littermates were challenged with Escherichia coli lipopolysaccharide (LPS; 5 mg/kg i.p.) and myocardial function was assessed 6 h later using echocardiography and hemodynamics. Deteriorated cardiac function evidenced by reduction of the percentage of left ventricular ejection fraction and fractional shortening after LPS administration was significantly attenuated by cardiomyocyte specific expression of ACOT1. αMHC-ACOT1 mice exhibited a markedly increase in glucose utilization and cardiac FAO compared with LPS-treated WT mice. Suppression of cardiac peroxisome proliferator activated receptor alpha (PPARa) and PPARγ-coactivator-1α (PGC1a) signaling observed in LPS-challenged WT mice was activated by the presence of ACOT1. These results suggest that ACOT1 has potential therapeutic values to protect heart from sepsis mediated dysfunction, possibly through activating PPARa/PGC1a signaling.

Traditional herbal pair Portulacae Herba and Granati Pericarpium alleviates DSS-induced colitis in mice through IL-6/STAT3/SOCS3 pathway.

BACKGROUND: Portulacae Herba and Granati Pericarpium pair (PGP) is a traditional Chinese herbal medicine treatment for colitis, clinically demonstrating a relatively favorable effect on relieving diarrhea and abnormal stools. However, the underlying mechanism remain uncertain. PURPOSE: The present study intends to evaluate the efficacy of PGP in treating colitis in mice and investigate its underlying mechanism. METHODS: The protective effect of PGP against colitis was determined by monitoring body weight, colon length, colon weight, and survival rate in mice. Colonic inflammation was assessed by serum cytokine levels, colonic H&E staining, and local neutrophil infiltration. The reversal of intestinal epithelial barrier damage by PGP was subsequently analyzed with Western blot and histological staining. Furthermore, RNA-seq analysis and molecular docking were performed to identify potential pathways recruited by PGP. Following the hints of the transcriptomic results, the role of PGP through the IL-6/STAT3/SOCS3 pathway in DSS-induced colitis mice was verified by Western blot. RESULTS: DSS-induced colitis in mice was significantly curbed by PGP treatment. PGP treatment significantly mitigated DSS-induced colitis in mice, as evidenced by improvements in body weight, DAI severity, survival rate, and inflammatory cytokines levels in serum and colon. Moreover, PGP treatment up-regulated the level of Slc26a3, thereby increasing the expressions of the tight junction/adherens junction proteins ZO-1, occludin and E-cadherin in the colon. RNA-seq analysis revealed that PGP inhibits the IL-6/STAT3/SOCS3 pathway at the transcriptional level. Molecular docking indicated that the major components of PGP could bind tightly to the proteins of IL-6 and SOCS3. Meanwhile, the result of Western blot revealed that the IL-6/STAT3/SOCS3 pathway was inhibited at the protein level after PGP administration. CONCLUSION: PGP could alleviate colonic inflammation and reverse damage to the intestinal epithelial barrier in DSS-induced colitis mice. The underlying mechanism involves the inhibition of the IL-6/STAT3/SOCS3 pathway.

Review on melanosis coli and anthraquinone-containing traditional Chinese herbs that cause melanosis coli.

Backgrounds: The incidence of melanosis coli (MC) has gradually increased annually, attracting significant attention and efforts into this field. A potential risk for MC is the long-term use of anthraquinone laxatives in patients with constipation. Most traditional cathartic drugs are made from herbs containing anthraquinone compounds. This review aims to provide guidance for the application of traditional Chinese herbs containing anthraquinones for physicians and researchers. Materials and methods: We reviewed risk factors and pathogenesis of MC, and natural anthraquinones isolated from TCM herbs. We searched Pubmed and CNKI databases for literature related to MC with keywords such as"traditional Chinese medicine", "Chinese herbs", "anthraquinones", and "melanosis coli". The literature is current to January 2023 when the searches were last completed. After the literature retrieval, the TCM herbs containing anthraquinones (including component identification and anthraquinone content determination) applied in clinical were selected. According to the collected evidence, we provide a list of herbs containing anthraquinones that could cause MC. Results: We identified 20 herbs belonging to 7 families represented by Polygonaceae, Fabaceae, Rhamnaceae, and Rubiaceae, which may play a role in the pathogenesis of MC. Among these, the herbs most commonly used include Dahuang (Rhei Radix et Rhizome), Heshouwu (Radix Polygoni Multiflori), Huzhang (Rhizoma Polygoni Cuspidati), Juemingzi (Semen Cassiae), Luhui (Aloe) and Qiancao (Rubiae Radix et Rhizoma). Conclusion: Due to a lack of awareness of the chemical composition of TCM herbs, many patients with constipation and even some TCM physicians take cathartic herbal remedies containing abundant anthraquinones to relieve defecation disturbances, resulting in long-term dependence on these herbs, which is potentially associated with most cases of MC. When such treatments are prescribed, TCM physicians should avoid long-term use in large doses to reduce their harm on colonic health. Individuals who take healthcare products containing these herbs should also be under the supervision of a doctor.

Network Pharmacology Research Indicates that Wu-Mei-Wan Treats Obesity by Inhibiting Th17 Cell Differentiation and Alleviating Metabolic Inflammation.

BACKGROUND: Wu-Mei-Wan (WMW), a traditional Chinese medicine (TCM) formula, has a good effect on the treatment of obesity and has been proven helpful to promote the metabolism of adipose tissue. However, its underlying mechanism remains to be studied. This study aims to explore the potential pharmacological mechanism of WMW in the treatment of obesity. METHODS: Network pharmacology was used to sort out the relationship between WMW putative targets and obesity-related drug targets or disease targets, which indicated the mechanism of WMW in treating obesity from two aspects of clinical drugs approved by the Food and Drug Administration (FDA) and obesity-related diseases. Databases such as Traditional Chinese Medicine Systems Pharmacology (TCMSP), PubChem, DrugBank, DisGeNET, and Genecards were used to collect information about targets. String platform was used to convert the data into gene symbol of "homo sapiens", and perform gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. With the Human Protein Reference Database (HPRD) as background data, Cytoscape 3.6.0 software was used to construct a new protein-protein interaction (PPI) network. Mechanism diagrams of key pathways were obtained from the KEGG database. AutoDock Vina software was used to conduct molecular docking verification. RESULTS: The number of targets in the overlap between WMW putative targets and obesity-related drug targets accounted for more than 50% of the latter, and HTR3A, SLC6A4, and CYP3A4 were core targets. In obesity-related disease targets-WMW putative targets PPI network, the Th17 cell differentiation pathway, and the IL-17 signaling pathway were key pathways, and the 1st module and the 7th module were central function modules that were highly associated with immunity and inflammation. Molecular docking verified that STAT3, TGFB1, MMP9, AHR, IL1B, and CCL2 were core targets in the treatment of WMW on obesity. CONCLUSION: WMW has similar effects on lipid and drug metabolism as the current obesity-related drugs, and is likely to treat obesity by inhibiting Th17 cell differentiation and alleviating metabolic inflammation.

6-gingerol ameliorates metabolic disorders by inhibiting hypertrophy and hyperplasia of adipocytes in high-fat-diet induced obese mice.

OBJECTIVES: Accumulating studies revealed that 6-gingerol, a compound extracted mainly from ginger, treats obesity by preventing hyperlipidemia in vivo induced by high-fat-diet (HFD). The present study intends to further evaluate the efficacy of 6-gingerol in the treatment of obesity and investigate its potential mechanism. METHODS: Obese mice were established by HFD induction. Bioinformatic analysis was used to predict the possible pathways enrolled by the application of 6-gingerol. Body weight and the levels of blood glucose and lipids were examined and analyzed for the evaluation of the therapeutic effect of 6-gingerol. The size and amounts as well as the status of adipocytes were determined by histological staining. The expression levels of related proteins in adipose tissue were assessed by immunohistochemical staining, immunofluorescent staining, and Western blot analysis. In addition, the expression levels of related mRNA were assessed by RT-qPCR. RESULTS: HFD induced obesity was significantly curbed by 6-gingerol treatment. Here inhibition mechanism of 6-gingerol is demonstrated on excessive hypertrophy and hyperplasia of adipocytes in white adipose tissue (WAT), which may be related to the regulation of adipocytokines, such as PPARγ, C/EBPα, FABP4 and adiponectin, and the TLR3/IL-6/JAK1/STAT3 axis. Moreover, 6-gingerol treatment suppressed the expressions of IL-1ß and CD68 in the liver and AKT/INSR/IRS-1 in epididymal WAT. CONCLUSION: The results suggested that 6-gingerol could alleviate metabolic inflammation in the liver and insulin resistance to treat obesity. The mechanism is mainly involved in the inhibition of excessive hypertrophy and hyperplasia of adipocytes.

HuanglianGanjiang Tang alleviates DSS-induced colitis in mice by inhibiting necroptosis through vitamin D receptor.

ETHNOPHARMACOLOGICAL RELEVANCE: HuanglianGanjiang Tang (HGT) is a classic prescription of traditional Chinese medicine (TCM) recorded in Dan Xi Xin Fa, which was used to alleviate manifestations like diarrhea, abdominal pain and hemafecia. In current clinical practices, HGT is adopted for the treatment of ulcerative colitis (UC) and affords good curative effect. However, the underlying mechanism deserves further elucidation. AIM OF THE STUDY: UC is a hard-to-curable and easy-to-recurrent inflammatory disease. This study is to evaluate the potential therapeutics and explore the molecular mechanism of HGT on UC in the mouse model. MATERIALS AND METHODS: The components of HGT extracts were identified by HPLC. The colitis of mice was induced by 3% (w./v.) dextran sulfate sodium (DSS). The HGT decoction was prepared through boiling and centrifuging. The mice were given HGT decoction via oral gavage (0.34 g/ml & 0.68 g/ml; 5 ml/kg b.w.). The protective role of HGT on colitis mice was evaluated by body weight change, colon length, disease activity index (DAI) and histological scores. The expressions of necroptosis-related and vitamin D receptor (VDR)-related proteins were measured by Western blot, RT-qPCR and immunofluorescence. RESULTS: HGT could significantly reduce the loss of body weight and colon length in colitis mice, and alleviated the DAI and histological scores. Mechanically, HGT also promoted the expression of E-cadherin, Occludin, ZO-1 and VDR, and reduced the level of intestinal inflammatory cytokines, such as, IL-6, IL-1ß and TNF-α. Besides, HGT downregulated the protein level of p-RIPK3, p-RIPK1 and p-MLKL while upregulated the protein level of Caspase-8 in colon tissue compared to the model group. CONCLUSION: Our study addressed that HGT can alleviate DSS-induced colitis of mice through inhibiting colonic necroptosis by upregulating the level of VDR.

Berberine in the treatment of ulcerative colitis: A possible pathway through Tuft cells.

Ulcerative colitis (UC) is an inflammatory bowel disease with complex pathogenesis, which is affected by genetic factors, intestinal immune status and intestinal microbial homeostasis. Intestinal epithelial barrier defect is crucial to the development of UC. Berberine, extracted from Chinese medicine, can identify bitter taste receptor on intestinal Tuft cells and activate IL-25-ILC2-IL-13 immune pathway to impair damaged intestinal tract by promoting differentiation of intestinal stem cells, which might be a potential approach for the treatment of UC.

Epoxyeicosatrienoic acids improve glucose homeostasis by preventing NF-κB-mediated transcription of SGLT2 in renal tubular epithelial cells.

Studies have shown that epoxyeicosatrienoic acids (EETs) can regulate glucose homeostasis, but the specific mechanisms need further exploration. The sodium-glucose co-transporter 2 (SGLT2) is highly expressed in diabetic kidneys, which further promotes renal reabsorption of glucose to respond to the hyperglycemic state of diabetes. Herein, whether EETs can be a latent inhibitor of SGLT2 to regulate glucose homeostasis in diabetic state needs to be elucidated. Our study demonstrated that EETs attenuated the glucose reabsorption via renal tubular epithelial cells in diabetic mice, which partly accounted for the beneficial effects of EETs on glucose homeostasis. Moreover, 14,15-EET suppressed SGLT2 expression in both diabetic kidney and renal tubular epithelial cells. Further, inhibition of NF-κB with BAY 11-7082 decreased insulin-induced SGLT2 expression while NF-κB overexpression reversed the above effects. In addition, 14,15-EET attenuated SGLT2 expression via inactivating NF-κB. Mechanistically, 14,15-EET attenuated NF-κB mediated SGLT2 transcription at the -1821/-1812 P65-binding site. These results showed that EETs ameliorated glucose homeostasis via preventing NF-κB-mediated transcription of SGLT2 in renal tubular epithelial cells, providing a unique therapeutic strategy for insulin resistance and diabetes.

Ameliorative Effects of Osthole on Experimental Renal Fibrosis in vivo and in vitro by Inhibiting IL-11/ERK1/2 Signaling.

Objectives: Natural product, osthole, has been proven to have a protective effect on organ fibrosis, including renal fibrosis. All of these studies are mainly focused on the regulation of TGF-ß/Smad signaling pathway. However, due to the pleiotropic roles of TGF-ß/Smad signaling, direct TGF-ß-targeted treatments are unlikely to be therapeutically feasible in clinic. Recently, the downstream IL-11/ERK1/2 signaling of TGF-ß has become an attractive therapeutic target without upstream disadvantages. Based on that, this study was designed to identify the potential effects of osthole on IL-11/ERK1/2 signaling pathway in renal fibrosis. Methods: The renal fibrosis model was established in vivo and in vitro, we investigated the effects of osthole on unilateral ureteral obstruction (UUO)-induced renal fibrosis and TGF-ß-induced HK-2 cells. After preliminarily confirming the antifibrogenic effects of osthole and the link between its antifibrogenic effects and the inhibition of IL-11/ERK1/2 signaling, we applied a direct IL-11-induced HK-2 cells fibrosis model to further explore the inhibitory effects of osthole on IL-11/ERK1/2 signaling pathway. Results: Our results confirmed that osthole can decrease the secretion of fibrosis proteins, such as α-smooth muscle actin (α-SMA), collagen I, and fibronectin, ameliorate experimental renal fibrosis in vivo and in vitro, and the effect was associated with suppressing TGF-ß1/Smad signaling. More importantly, we found that IL-11/ERK1/2 signaling in UUO-induced renal fibrosis and TGF-ß-induced HK-2 cell model was obviously upregulated, and osthole treatment also significantly inhibited the abnormal IL-11/ERK1/2 signaling activation. Given the direct link between TGF-ß/Smad signaling and IL-11/ERK1/2 signaling pathway, we have verified that osthole has a direct inhibitory effect on IL-11/ERK1/2 signaling independent of TGF-ß signaling by using an IL-11-induced HK-2 cells fibrosis model. Osthole treatment decreased the protein expression of α-SMA, collagen I and fibronectin without changing their mRNA levels in IL-11-induced HK-2 cells. Moreover, it was observed that the IL-11/ERK1/2 inhibitor, U0126, partly blocked the antifibrogenic effects of osthole. Conclusion: In this study, we found that osthole has a previously unrecognized role in inhibiting IL-11/ERK1/2 signaling pathway. Our work demonstrated that the antifibrogenic effect of osthole is not only mediated by TGF-ß/Smad2/3 signaling, but also directly mediated by IL-11/ERK1/2 signaling pathway independent of TGF-ß1 signaling.

Traditional herbal formula Wu-Mei-Wan alleviates TNBS-induced colitis in mice by inhibiting necroptosis through increasing RIPK3 O-GlcNAcylation.

BACKGROUND: Accumulating evidence indicated that necroptosis plays an essential role in the pathogenesis of inflammatory bowel disease (IBD). The O-linked ß-N-acetylglucosaminylation (O-GlcNAcylation) of necroptotic signal molecule receptor-interacting serine-threonine kinase 3 (RIPK3) was reported to exert a protective effect in gut inflammation. Our recent study suggested traditional Chinese herbal formula Wu-Mei-Wan (WMW) as an effective prescription in mouse colitis. However, the potential mechanisms are not fully understood. Considering the crucial role of necroptosis in the pathogenesis of IBD, therefore, this study was designed to explain whether the anti-colitis effect of WMW is mediated by modulating necroptosis and its related mechanisms. METHODS: The protective effects of WMW on colitis have been determined by detecting colitis mice body weight, disease activity index (DAI), survival rate and colon length. Colonic inflammation was examined by inflammatory cells infiltration and local cytokines levels. After then, we measured the levels of necroptosis and O-GlcNAcylation. C O-immunoprecipitation experiments were used to address whether elevated O-GlcNAcylation can inhibit necroptotic signal transduction in the treatment of WMW. Finally, the key enzymes in O-GlcNAcylation: O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA) were examined and molecular docking analysis was used to determine effective natural compounds in the regulation on OGT and OGA activities. RESULTS: Our results showed that WMW significantly improved mice body weight, survival rate and colon length, decreased DAI in TNBS-induced colitis. WMW obviously alleviated colonic inflammatory responses with reduced macrophages, neutrophils infiltration and local IL-1ß, IL-6, TNF-α and IFN-γ levels. It was found that WMW increased colonic O-GlcNAcylation level and inhibited the activation of RIPK1, RIPK3 and MLKL. Then, further experiments revealed that WMW enhanced OGT activity and suppressed OGA activity, thereby increasing RIPK3 O-GlcNAcylation and inhibiting the binding of RIPK3 and MLKL, which led to the inhibition of necroptosis. Additionally, docking analysis demonstrated that hesperidin, coptisine and ginsenoside Rb1 may exert a major role in the regulation on OGT and OGA activities by WMW. CONCLUSION: Our work demonstrated that WMW can alleviate TNBS-induced colitis in mice by inhibiting necroptosis through increasing RIPK3 O-GlcNAcylation.

Proximity-induced exponential amplification reaction triggered by proteins and small molecules.

We proposed a method to regulate nucleic acid polymerization by proximity and designed an ultrasensitive biosensor based on proximity-induced exponential amplification reaction for proximity assay of proteins (streptavidin) and small molecules (adenosine triphosphate), which allows us to detect a variety of interesting targets by simply changing the binding sites of DNA.