Hyperglycemia aggravates acute liver injury by promoting liver-resident macrophage NLRP3 inflammasome activation via the inhibition of AMPK/mTOR-mediated autophagy induction

Synergistic Efficacy of Policosanol (Raydel®) and Banaba Leaf Extract to Treat Hyperglycemia and Dyslipidemia in Streptozotocin-Induced Diabetic and Hyperlipidemic Zebrafish (Danio rerio): Protection of Liver and Kidney with Enhanced Tissue Regeneration

Background: The efficacy of banaba leaf extract was tested against carboxymethyllysine (CML)-induced toxicity in embryos and adult zebrafish. Additionally, the individual and combined effects of banaba (BNB) and policosanol (PCO) were analyzed to alleviate dyslipidemia, hyperglycemia, and associated effects in streptozotocin (STZ)-induced hyperlipidemic diabetic zebrafish. Methodology: The high cholesterol diet (HCD, final 4%, w/w)-fed zebrafish were injected with STZ to develop diabetes and were subsequently fed with either HCD or HCD+BNB (final 0.1% w/w) or HCD+PCO (final 0.1% w/w) or HCD+BNB+PCO (each final 0.1%, w/w) each for 14 days. The zebrafish tail fin was amputated to assess tissue regeneration, while the organs and blood were collected for histological and biochemical analysis. Results: Severely compromised embryo survivability and developmental defects were noticed in the CML-injected group that significantly improved following BNB exposure. Similarly, CML-induced acute paralysis and mortality of adult zebrafish were effectively mitigated by the treatment with BNB. In the hyperlipidemic diabetic zebrafish, both BNB and PCO supplementation displayed the hypoglycemic effect; however, a remarkable reduction (p < 0.05) in blood glucose levels was observed in the BNB+PCO group, around 14% and 16% less than the BNB group and PCO group, respectively. Likewise, higher tail fin regeneration was noticed in response to BNB+PCO supplementation. Both BNB and PCO have a substantial counter-effect against HCD+STZ-induced dyslipidemia. However, the combined supplementation (BNB+PCO) displayed a significantly better effect than that of BNB and PCO alone to alleviate total cholesterol (TC), triglycerides (TGs), and low-density lipoprotein cholesterol (LDL-C). The most impressive impact of BNB+PCO was noticed in the elevation of high-density lipoprotein cholesterol (HDL-C), which was ~1.5 times higher than the HDL-C level in response to BNB and PCO. Also, BNB+PCO effectively reduced the malondialdehyde (MDA) and elevated the plasma sulfhydryl content, paraoxonase (PON), and ferric ion reduction (FRA) activity. Histological analyses revealed a significant effect of BNB+PCO in preventing inflammatory infiltration, fatty liver changes, and interleukin-6 production. Similarly, a notably better effect of BNB+PCO compared to their individual effect was noticed in preventing kidney damage and mitigation of ROS generation, apoptosis, and cellular senescence. Conclusions: The finding establishes the substantial effect of BNB and PCO in countering hyperglycemia, dyslipidemia, and associated disorders, which synergistically improved following the combined supplementation with BNB+PCO.

The probiotic Lacticaseibacillus rhamnosus SD11 alleviates the progression of liver and colon damage through modulation of inflammation and tight junction proteins in streptozotocin-induced diabetic mice

Lacticaseibacillus rhamnosus SD11 (SD11) has several health benefits for the host, including antidiabetic, anti-inflammatory, and antimicrobial effects. However, the antidiabetic mechanism of SD11 has not been clearly elucidated. The current study assessed the effects of SD11 and the associated underlying mechanisms on streptozotocin (STZ)-induced diabetic mice. Compared with the normal control, SD11 supplementation for 4 weeks significantly improved the metabolic profiles, including body weight (BW), fasting blood glucose (FBG), fasting insulin level (FIN), and liver index (LI), in conjunction with a lower NAS score. A notable reduction in the liver function parameters aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) and total cholesterol (TC), together with histopathology studies, supported diabetic recovery by SD11. A closer examination of two major markers for the insulin pathway, insulin receptor (INSR) and insulin substrate (IRS)-1, revealed that SD11 could exert its glucose control through the upregulation of these molecules, which were almost demolished in nontreated diabetic livers. Additionally, SD11-treated mice exhibited alleviation of oxidative stress enzymes; downregulation of proinflammatory cytokines, including interleukin (IL)-6, IL-1β, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ; and decreased infiltration of macrophages into liver tissue. These findings were concomitant with the preservation of the tight junction proteins occludin and zona occludin (ZO)-1, which in turn lowered the levels of the inflammatory cytokines IL-1β and TNF-α and prevented colon tissue injury to some extent. Notably, the results for the SD11 control mice were identical to those for the normal control mice. Overall, our findings that SD11 delays liver deterioration and reduces colon lesions in diabetic mice provide evidence for the use of SD11 as an effective strategy to improve diabetes-related symptoms.

Diagnosis of acute hyperglycemia based on data-driven prediction models

Acute hyperglycemia is a common endocrine and metabolic disorder that seriously threatens the health and life of patients. Exploring effective diagnostic methods and treatment strategies for acute hyperglycemia to improve treatment quality and patient satisfaction is currently one of the hotspots and difficulties in medical research. This article introduced a method for diagnosing acute hyperglycemia based on data-driven prediction models. In the experiment, clinical data from 1000 patients with acute hyperglycemia were collected. Through data cleaning and feature engineering, 10 features related to acute hyperglycemia were selected, including BMI (Body Mass Index), TG (triacylglycerol), HDL-C (High-density lipoprotein cholesterol), etc. The support vector machine (SVM) model was used for training and testing. The experimental results showed that the SVM model can effectively predict the occurrence of acute hyperglycemia, with an average accuracy of 96 %, a recall rate of 84 %, and an F1 value of 89 %. The diagnostic method for acute hyperglycemia based on data-driven prediction models has a certain reference value, which can be used as a clinical auxiliary diagnostic tool to improve the early diagnosis and treatment success rate of acute hyperglycemia patients.

Fatty acids promote M1 polarization of monocyte-derived macrophages in healthy or ketotic dairy cows and a bovine macrophage cell line by impairing mTOR-mediated autophagy

Excessive concentrations of free fatty acids (FFA) are the main factors causing immune dysfunction and inflammation in dairy cows with ketosis. Polarization of macrophages (the process of macrophages freely switching from one phenotype to another) into M1 or M2 phenotypes is an important event during inflammation induced by environmental stimuli. In nonruminants, mammalian target of rapamycin (mTOR)-mediated autophagy (a major waste degradation process) regulates macrophage polarization. Thus, our objective was to unravel the role of mTOR-mediated autophagy on macrophage polarization in ketotic dairy cows. We performed 4 experiments: (1) In vitro differentiated monocyte-derived macrophages from healthy dairy cows or dairy cows with clinical ketosis (CK) were treated for 24 h with 100 ng/mL LPS and 100 ng/mL IFN-γ or with 10 ng/mL IL4 and 10 ng/mL IL10; (2) Immortalized bovine macrophages were treated for 24 h with 0, 0.3, 0.6, or 1.2 mM FFA, LPS, and IFN-γ, or with IL4 and IL10; (3) Macrophages were pretreated with 2 μM 4,6-dimorpholino-N-(4-nitrophenyl)-1,3,5-triazin-2-amine (MHY1485) for 30 min before treatment with LPS and IFN-γ or IL4 and IL10; (4) Macrophages were pretreated with 100 nM rapamycin (RAPA) for 2 h before treatment with LPS and IFN-γ or IL4 and IL10. Compared with healthy cows, cows with CK had a greater mean fluorescence intensity (MFI) of CD86+, but lower MFI of CD206+ and lower number of autophagosomes and autolysosomes in macrophages. Exogenous FFA treatment upregulated protein abundance of inducible nitric oxide synthase (iNOS) and the MFI of CD86, whereas it downregulated the protein abundance of arginase 1 and the MFI of CD206. In addition, FFA increased the p-p65/p65 protein abundance and tumor necrosis factor α, IL1B, and IL6 mRNA abundance, but decreased LC3-phosphatidylethanolamine conjugate protein abundance and the number of autophagosomes and autolysosomes number. Pretreatment with MHY1485 promoted macrophage M1 polarization and inhibited macrophage M2 polarization via decreased mTOR-mediated autophagy. Activation of mTOR-mediated autophagy by pretreatment with RAPA attenuated the upregulation of inflammation in M1 macrophages that was induced by FFA. These data revealed that high concentrations of FFA promote macrophage M1 polarization in ketotic dairy cows by impairing mTOR-mediated autophagy.

Diabetic cardiomyopathy: Importance of direct evidence to support the roles of NOD-like receptor protein 3 inflammasome and pyroptosis

Recently, the roles of pyroptosis, a form of cell death induced by activated NOD-like receptor protein 3 (NLRP3) inflammasome, in the pathogenesis of diabetic cardiomyopathy (DCM) have been extensively investigated. However, most studies have focused mainly on whether diabetes increases the NLRP3 inflammasome and associated pyroptosis in the heart of type 1 or type 2 diabetic rodent models, and whether various medications and natural products prevent the development of DCM, associated with decreased levels of cardiac NLRP3 inflammasome and pyroptosis. The direct link of NLRP3 inflammasome and associated pyroptosis to the pathogenesis of DCM remains unclear based on the limited evidence derived from the available studies, with the approaches of NLRP3 gene silencing or pharmaceutical application of NLRP3 specific inhibitors. We thus emphasize the requirement for more systematic studies that are designed to provide direct evidence to support the link, given that several studies have provided both direct and indirect evidence under specific conditions. This editorial emphasizes that the current investigation should be circumspect in its conclusion, i.e., not overemphasizing its role in the pathogenesis of DCM with the fact of only significantly increased expression or activation of NLRP3 inflammasome and pyroptosis in the heart of diabetic rodent models. Only clear-cut evidence-based causative roles of NLRP3 inflammasome and pyroptosis in the pathogenesis of DCM can help to develop effective and safe medications for the clinical management of DCM, targeting these biomarkers.

Role of Olive Leaf Extract, Mesenchymal Stem Cells or Low Radiation Dose in Alleviating Hepatic Injury in Rats

Objectives

This study was conducted to determine the efficacy of mesenchymal stem cells (MSCs) or low-dose gamma radiation (LDR) on liver injury compared to the effect of olive leaf extract as a hepatoprotective agent.

Methods

Rats were allocated into six groups; group I served as the negative control. Group II received 5% dextran sodium sulfate (DSS) in its drinking water for 1 week. Group III was injected with a single dose of 1 × 106 bone marrow-derived mesenchymal stem cells (BM-MSCs) intravenously. Group IV was treated as in group III after 5% DSS treatment. Group V was given 5% DSS, followed by olive leaf extract (OLE) (1000 mg/ kg, oral). Group VI: 5% DSS for 1 week, then was exposed to low-dose gamma radiation (LDR) (0.05 Gy).

Results

Rats treated with OLE, BM-MSCs, or exposed to LDR exerted significant alleviation in all hepatic biomarkers, significant enhancements in oxidative stress parameters, and improvements in inflammatory biomarkers Interleukin-1 beta (IL-1β) and Interferon gamma (INF-γ) hepatic contents compared with those of the DSS group. Histological pictures emphasized the biochemical findings.

Conclusions

BM-MSCs might be a valuable therapeutic approach to overcome hepatic injury. Exposure to LDR provided protective mechanisms that allow the body to survive better.

NIR-I emissive cyanine derived molecular probe for selective monitoring of hepatic albumin levels during hyperglycemia

In this study, we report a small molecule optical marker BI-CyG derived from the structural engineering of a cyanine scaffold. The developed probe offers suitable advantages over existing cyanine-based albumin specific probes in terms of its excitation and emission wavelengths, which are 760 and 830-832 nm, respectively. Structural tuning of the cyanine architecture leading to extended π-conjugation and resulting in a suitable bathochromic shift in the emission wavelength of the probe is represented in this study. The probe besides emitting in the NIR region, also possesses the desirable characteristics of being a potential target selective optical marker, as established from various biophysical studies. Molecular modelling and simulation studies provided critical insights into the binding of the probe in the protein microenvironment, which was further supported by experimental studies. The probe displayed intracellular albumin selectivity and was utilized for demonstrating alteration in albumin levels in pathological states such as hyperglycemia in hepatic cells. The present study also sheds some light on using BI-CyG as an imaging probe and on the role of metformin as a suitable drug for balancing hyperglycemia-induced reduced intra-hepatic albumin levels. The study, thus, attempts to highlight the structural derivatization of cyanine to afford a potential probe for serum albumin and its deployment to image altering albumin levels in an induced pathological condition, hyperglycemia.

FoxG1 as a Potential Therapeutic Target for Alzheimer's Disease: Modulating NLRP3 Inflammasome via AMPK/mTOR Autophagy Pathway

An increasing body of research suggests that promoting microglial autophagy hinders the neuroinflammation initiated though the NLRP3 inflammasome activation in Alzheimer's disease (AD). The function of FoxG1, a crucial transcription factor involved in cell survival by regulating mitochondrial function, remains unknown during the AD process and neuroinflammation occurs. In the present study, we firstly found that Aβ peptides induced AD-like neuroinflammation upregulation and downregulated the level of autophagy. Following low-dose Aβ25-35 stimulation, FoxG1 expression and autophagy exhibited a gradual increase. Nevertheless, with high-concentration Aβ25-35 treatment, progressive decrease in FoxG1 expression and autophagy levels as the concentration of Aβ25-35 escalated. In addition, FoxG1 has a positive effect on cell viability and autophagy in the nervous system. In parallel with the Aβ25-35 stimulation, we employed siRNA to decrease the expression of FoxG1 in N2A cells. A substantial reduction in autophagy level (Beclin1, LC3II, SQSTM1/P62) and a notable growth in inflammatory response (NLRP3, TNF-α, and IL-6) were observed. In addition, we found FoxG1 overexpression owned the effect on the activation of AMPK/mTOR autophagy pathway and siRNA-FoxG1 successfully abolished this effect. Lastly, FoxG1 suppressed the NLRP3 inflammasome and enhanced the cognitive function in AD-like mouse model induced by Aβ25-35. Confirmed by cellular and animal experiments, FoxG1 suppressed NLRP3-mediated neuroinflammation, which was strongly linked to autophagy regulated by AMPK/mTOR. Taken together, FoxG1 may be a critical node in the pathologic progression of AD and has the potential to serve as therapeutic target.

LanGui tea, an herbal medicine formula, protects against binge alcohol-induced acute liver injury by activating AMPK-NLRP3 signaling

BACKGROUND

LanGui tea, a traditional Chinese medicine formulation comprising of Gynostemma pentaphyllum (Thunb.) Makino, Cinnamomum cassia (L.) J. Presl, and Ampelopsis grossedentata (Hand-Mazz) W.T. Wang, has yet to have its potential contributions to alcoholic liver disease (ALD) fully elucidated. Consequently, the objective of this research is to investigate the protective properties of LanGui tea against binge alcohol-induced ALD and the mechanisms underlying its effects.

METHODS

An experimental model of acute alcohol-induced liver disease was performed to assess the protective effects of extract of LanGui tea (ELG) at both 50 and 100 mg.kg-1 dosages on male C57BL/6 mice. Various parameters, including hepatic histological changes, inflammation, lipids content, as well as liver enzymes and interleukin 1β (IL-1β) in the serum were measured. The pharmacological mechanisms of ELG, specifically its effects on adenosine monophosphate-(AMP)-activated protein kinase (AMPK) and NLR family pyrin domain containing 3 (NLRP3) signaling, were investigated through Western blotting, qRT-PCR, ELISA, immunohistochemistry, immunofluorescence analyses, and by blocking the AMPK activity.

RESULTS

ELG demonstrated a mitigating effect on fatty liver, inflammation, and hepatic dysfunction within the mouse model. This effect was achieved by activating AMPK signaling and inhibitingNLRP3 signaling in the liver, causing a reduction in IL-1β generation. In vitro studies further confirmed that ELG inhibited cell damage and IL-1β production in ethanol-induced hepatocytes by enhancing AMPK-NLRP3 signaling. Conversely, the pharmacological inhibition of AMPK activity nearly abrogated such alteration.

CONCLUSIONS

Thus, LanGui tea emerges as a promising herbal therapy for ALD management involving AMPK-NLRP3 signaling.

Targeting toll-like receptor 4 (TLR4) and the NLRP3 inflammasome: Novel and emerging therapeutic targets for hyperuricaemia nephropathy

The clinical manifestation of hyperuricaemia, known as hyperuricaemia nephropathy, is relatively common. Its pathophysiology is largely based on chronic inflammation in circulatory and renal tissues. Toll-like receptor 4 (TLR4), a subclass of innate immune receptors, detects both pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs), initiating inflammatory and immune responses that lead to the release of pro-inflammatory cytokines interleukin 1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α). These cytokines are pivotal in renal inflammation, especially in conditions like hyperuricaemia, acute renal injury, ischemia-reperfusion injury, and acute renal failure. The nucleotide-binding oligomerization domain (NOD)-like receptor pyrin domain-containing 3 (NLRP3) inflammasome, an essential component of the innate immune signaling complex, plays a central role in inflammation. It finely regulates the activation of caspase-1 and the production and secretion of the pro-inflammatory cytokine IL-1β, mediating and amplifying the inflammatory cascade response. Activation of TLR4 indirectly promotes the assembly of the NLRP3 inflammasome by regulating the nuclear factor kappa B (NF-κB) signaling pathway, thereby amplifying the inflammatory process and playing a significant pro-inflammatory role in hyperuricaemia nephropathy. TLR4 and NLRP3 inflammasome are anticipated to be novel markers and therapeutic targets for assessing treatment efficacy and prognosis in hyperuricaemia nephropathy. This paper provides a comprehensive overview of the structural composition and biological functions of TLR4 and NLRP3 inflammasome and systematically reviews their relevance in the pathogenesis of hyperuricaemia nephropathy.

Protective role of Dodonaea viscosa extract against streptozotocin-induced hepatotoxicity and nephrotoxicity in rats

Previous investigations have shown that D. viscosa herbal extract is often used to treat a variety of diseases. Therefore, the purpose of this study was to investigate any additional potential impacts on rat liver and kidney damage induced by diabetes. Streptozotocin (STZ) (60 mg/kg/day) was given as a single dosage to cause type 1 diabetes. After then, diabetic rats received oral doses of D. viscosa for four weeks at 150 and 300 mg/kg/day. Blood, liver, and kidney tissues were collected at the end of the treatment and examined. Analysis was made of the serum lipid profile, liver, and kidney functions, as well as blood biochemistry. Moreover, the levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1 beta (IL-1β), prostaglandin E-2 (PGE-2), and nitric oxide (NO) were estimated in serum. In liver and kidney samples, thiobarbituric acid reactive substances (TBARs) and reduced glutathione (GSH), as well as the pro-inflammatory cytokines and enzymatic activities of glutathione peroxidase (GPx), glutathione reeducates (GR), glutathione-S-transferase (GST), catalase (CAT), and superoxide dismutase (SOD) were analyzed. Histological changes in liver and kidney cross-sections were also observed. Our findings demonstrated that D. viscosa dramatically decreased pro-inflammatory indicators in blood, kidney, and liver tissues as well as blood glucose, and restored insulin levels, and lipid profiles. Additionally, it significantly raises the antioxidant enzyme activity SOD, CAT, GPx, and GST, while significantly lowering TBARs levels. The above-mentioned biochemical changes that took place in tissues were further supported by histological alterations. These findings imply that D. viscosa protects against STZ-induced hyperglycemia, aberrant lipid synthesis, and oxidative stress and that these benefits may be mediated by interacting with various targets to increase the levels of antioxidant enzymes in the liver and kidneys. Its mode of action and safety for use as medicine against various metabolic problems caused by diabetes require more research.

Syringin alleviates hepatic fibrosis by enhancing autophagic flux and attenuating ER stress-TRIB3/SMAD3 in diabetic mice

Type 2 diabetes mellitus (T2DM) is a key risk factor for the developing of metabolic liver injury and easily evolving to advanced fibrosis. Syringin (SYR), isolated from Acanthopanax senticosus, has anti-inflammatory, anti-oxidant, and anti-apoptotic properties. However, its hepatoprotective effects and mechanisms in T2DM-induced liver fibrosis remain unclear. Here, we investigated whether syringin (SYR) could serve as a therapeutic agent for liver fibrosis and its mechanism in high-fat diet (HFD)/streptozotocin (STZ)-induced type 2 diabetic mice. C57BL/6 mice were induced with T2DM via HFD and STZ injection and treated with different doses of SYR. Serum lipid parameters and liver function indicators were measured, and hepatic histology and fibrosis were examined. The mechanism of SYR was explored through molecular analyses Results demonstrated SYR improved oral glucose tolerance, decreased the levels of ALT, AST, and AKP, and reduced hepatic lipid deposition in diabetic mice. Moreover, SYR ameliorated epithelial-to-mesenchymal transition to reverse hepatic fibrosis via suppressing TRIB3-SMAD3 interaction to restrain nuclear localization of SMAD3. Strikingly, SYR reversed hyperglycemia-induced deficiency in autophagic flux by regulation of Raptor/mTORC1, triggering nuclear translocation of TFEB to improve autophagosome-lysosomal fusion. In brief, SYR potentially ameliorates hepatic injury and fibrosis by enhancing autophagic flux and inhibing TRIB3 activation in diabetic mice.

Autophagy in hepatic macrophages can be regulator and potential therapeutic target of liver diseases: A review

Hepatic macrophages are a complex population of cells that play an important role in the normal functioning of the liver and in liver diseases. Autophagy, as a maintainer of cellular homeostasis, is closely connected to many liver diseases. And its roles are not always beneficial, but manifesting as a double-edged sword. The polarization of macrophages and the activation of inflammasomes are mediated by intracellular and extracellular signals, respectively, and are important ways for macrophages to take part in a variety of liver diseases. More attention should be paid to autophagy of hepatic macrophages in liver diseases. In this review, we focus on the regulatory role of hepatic macrophages' autophagy in a variety of liver diseases; especially on the upstream regulator of polarization and inflammasomes activation of the hepatic macrophages. We believe that the autophagy of hepatic macrophages can become a potential therapeutic target for management of liver diseases.

Role of emodin in atherosclerosis and other cardiovascular diseases: Pharmacological effects, mechanisms, and potential therapeutic target as a phytochemical

The morbidity and mortality of cardiovascular diseases (CVDs) are increasing in recent years, and atherosclerosis (AS), a major CVD, becomes a disorder that afflicts human beings severely, especially the elders. AS is recognized as the primary cause and pathological basis of some other CVDs. The active constituents of Chinese herbal medicines have garnered increasing interest in recent researches owing to their influence on AS and other CVDs. Emodin (1,3,8-trihydroxy-6-methylanthraquinone) is a naturally occurring anthraquinone derivative found in some Chinese herbal medicines such as Rhei radix et rhizome, Polygoni cuspidati rhizoma et radix and Polygoni multiflori root. In this paper, we first review the latest researches about emodin's pharmacology, metabolism and toxicity. Meanwhile, it has been shown to be effective in treating CVDs caused by AS in dozens of previous studies. Therefore, we systematically reviewed the mechanisms by which emodin treats AS. In summary, these mechanisms include anti-inflammatory activity, lipid metabolism regulation, anti-oxidative stress, anti-apoptosis and vascular protection. The mechanisms of emodin in other CVDs are also discussed, such as vasodilation, inhibition of myocardial fibrosis, inhibition of cardiac valve calcification and antiviral properties. We have further summarized the potential clinical applications of emodin. Through this review, we hope to provide guidance for clinical and preclinical drug development.

MALAT1-mediated EZH2 Recruitment to the GFER Promoter Region Curbs Normal Hepatocyte Proliferation in Acute Liver Injury

BACKGROUND AND AIMS

The goal of this study was to investigate the mechanism by which the long noncoding RNA MALAT1 inhibited hepatocyte proliferation in acute liver injury (ALI).

METHODS

Lipopolysaccharide (LPS) was used to induce an ALI cellular model in HL7702 cells, in which lentivirus vectors containing MALAT1/EZH2/GFER overexpression or knockdown were introduced. A series of experiments were performed to determine their roles in liver injury, oxidative stress injury, and cell biological processes. The interaction of MALAT1 with EZH2 and enrichment of EZH2 and H3K27me3 in the GFER promoter region were identified. Rats were treated with MALAT1 knockdown or GFER overexpression before LPS induction to verify the results derived from the in vitro assay.

RESULTS

MALAT1 levels were elevated and GFER levels were reduced in ALI patients and the LPS-induced cell model. MALAT1 knockdown or GFER overexpression suppressed cell apoptosis and oxidative stress injury induced cell proliferation, and reduced ALI. Functionally, MALAT1 interacted directly with EZH2 and increased the enrichment of EZH2 and H3K27me3 in the GFER promoter region to reduce GFER expression. Moreover, MALAT1/EZH2/GFER was activated the AMPK/mTOR signaling pathway.

CONCLUSION

Our study highlighted the inhibitory role of reduced MALAT1 in ALI through the modulation of EZH2-mediated GFER.

Programmed cell death and lipid metabolism of macrophages in NAFLD

Non-alcoholic fatty liver disease (NAFLD) has now become the leading chronic liver disease worldwide with lifestyle changes. This may lead to NAFLD becoming the leading cause of end-stage liver disease in the future. To date, there are still no effective therapeutic drugs for NAFLD. An in-depth exploration of the pathogenesis of NAFLD can help to provide a basis for new therapeutic agents or strategies. As the most important immune cells of the liver, macrophages play an important role in the occurrence and development of liver inflammation and are expected to become effective targets for NAFLD treatment. Programmed cell death (PCD) of macrophages plays a regulatory role in phenotypic transformation, and there is also a certain connection between different types of PCD. However, how PCD regulates macrophage polarization has still not been systematically elucidated. Based on the role of lipid metabolic reprogramming in macrophage polarization, PCD may alter the phenotype by regulating lipid metabolism. We reviewed the effects of macrophages on inflammation in NAFLD and changes in their lipid metabolism, as well as the relationship between different types of PCD and lipid metabolism in macrophages. Furthermore, interactions between different types of PCD and potential therapeutic agents targeting of macrophages PCD are also explored.

Bone marrow-derived mesenchymal stem cell-conditioned medium ameliorates diabetic foot ulcers in rats

OBJECTIVES

This study aimed to explore the effects of bone marrow-derived Mesenchymal Stem Cell-Conditioned Medium (MSC-CM) treating diabetic foot ulcers in rats.

METHODS

Models of T2DM rats were induced by a high-fat diet and intraperitoneal injection of STZ in SD rats. Models of Diabetic Foot Ulcers (DFUs) were made by operation on hind limbs in diabetic rats. Rats were divided into four groups (n = 6 for each group), i.e., Normal Control group (NC), Diabetes Control group (DM-C), MSC-CM group and Mesenchymal Stem Cells group (MSCs). MSC-CM group was treated with an injection of conditioned medium derived from preconditioned rats' bone marrow MSCs around ulcers. MSCs group were treated with an injection of rats' bone marrow MSCs. The other two groups were treated with an injection of PBS. After the treatment, wound closure, re-epithelialization (thickness of the stratum granulosums of the skin, by H&E staining), cell proliferation (Ki67, by IHC), angiogenesis (CD31, by IFC), autophagy (LC3B, by IFC and WB; autolysosome, by EM) and pyroptosis (IL-1β, NLRP3, Caspase-1, GSDMD and GSDMD-N, by WB) in ulcers were evaluated.

RESULTS

After the treatment wound area rate, IL-1β by ELISA, and IL-1β, Caspase-1, GSDMD and GSDMD-N by WB of MSC-CM group were less than those of DM group. The thickness of the stratum granulosums of the skin, proliferation index of Ki67, mean optic density of CD31 and LC3B by IFC, and LC3B by WB of MSC-CM group were more than those of DM group. The present analysis demonstrated that the injection of MSC-CM into rats with DFUs enhanced the wound-healing process by accelerating wound closure, promoting cell proliferation and angiogenesis, enhancing cell autophagy, and reducing cell pyroptosis in ulcers.

CONCLUSIONS

Studies conducted indicate that MSC-CM administration could be a novel cell-free therapeutic approach to treat DFUs accelerating the wound healing process and avoiding the risk of living cells therapy.

Effects of Rice-Husk Silica Liquid in Streptozotocin-Induced Diabetic Mice

Type 2 diabetes mellitus is a complex multifactorial disease characterized by poor glucose tolerance and insulin resistance. Rice-husk silica liquid (RHSL) derived from rice husk has the ability to improve the dysfunction of pancreatic β-cells. This study aimed to confirm the potential protective effects of RHSL in streptozotocin (STZ)-induced diabetic mice. Diabetes was induced in male C57BL/6J mice by intraperitoneal administration of STZ (200 mg/kg BW). RHSL, food-grade silica liquid (FDSL), and rosiglitazone (RSG) were administered to diabetic mice for 12 weeks after successful induction of diabetes. During the experiment, fasting blood glucose, serum insulin, and organ weights were measured. The histopathology of liver tissue was evaluated by H&E staining. Western blotting was performed to assess protein expression levels. The results showed that RHSL significantly reversed the serum insulin levels and improved oral glucose tolerance test (OGTT) results (p < 0.05). In addition, liver sections of STZ-induced diabetic mice after RHSL treatment showed neatly arranged and intact hepatocytes. Furthermore, RHSL was more effective than FDSL in increasing the expression of SIRT1 and decreasing the expression of the PPAR-γ and p-NF-κB proteins. Taken together, this study demonstrated that RHSL ameliorated STZ-induced insulin resistance and liver tissue damage in C57BL/6J mice.

The regulatory role and mechanism of autophagy in energy metabolism-related hepatic fibrosis

Hepatic fibrosis is a key pathological process of chronic liver diseases, caused by alcohol, toxic and aberrant energy metabolism. It progresses to cirrhosis or even hepatic carcinoma without effective treatment. Studies have shown that autophagy has important regulatory effects on hepatic stellate cells (HSCs) energy metabolism, and then affect the activation state of HSCs. Autophagy maintains hepatic energy homeostasis, and the dysregulation of autophagy can lead to the activation of HSCs and the occurrence and development of hepatic fibrosis. It is necessary to explore the mechanism of autophagy in energy metabolism-related hepatic fibrosis. Herein, the current study summarizes the regulating mechanisms of autophagy through different targets and signal pathways in energy metabolism-related hepatic fibrosis, and discusses the regulatory effect of autophagy by natural plant-derived, endogenous and synthetic compounds for the treatment of hepatic fibrosis. A better comprehension of autophagy in hepatic stellate cells energy metabolism-related hepatic fibrosis may provide effective intervention of hepatic fibrosis, explore the potential clinical strategies and promote the drug treatment of hepatic fibrosis.

Design and synthesis of an N-benzyl 5-(4-sulfamoylbenzylidene-2-thioxothiazolidin-4-one scaffold as a novel NLRP3 inflammasome inhibitor

A series of N-benzyl 5-(4-sulfamoylbenzylidene-2-thioxothiazolidin-4-one analogs, designed as hybrids of CY09 and JC121, were investigated as inhibitors of NLRP3 inflammasome activation. Among them, compounds 34 and 36 were identified as promising NLRP3 inhibitors by measuring the amount of active caspase-1 p20 and IL-1β produced by NLRP3 inflammasome activation. Further studies indicated that both compounds inhibited NLRP3 inflammasome assembly by reducing the formation of NLRP3 and ASC oligomer specks and selectively inhibited only NLRP3 inflammasome activation and not other inflammasomes such as NLRC4 and AIM2.

NLRP3 and pyroptosis blockers for treating inflammatory diseases

The nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing protein 3 (NLRP3) inflammasome has emerged as a key mediator of pathological inflammation in many diseases and is an exciting drug target. Here, we review the molecular basis of NLRP3 inhibition by drug-like small molecules under development as novel therapeutics. We also summarize recent strategies to block pyroptosis as a novel approach to suppress chronic inflammation. Major recent developments in this area include the elucidation of mechanisms of action (MoAs) by which small molecules block NLRP3 inflammasome assembly and gasdermin D (GSDMD)-induced pyroptosis. We also discuss the status of clinical trials using agents that block specific components of the NLRP3 pathway, including their potential clinical applications for the treatment of many diseases.

Inhibition of Notch activity suppresses hyperglycemia-augmented polarization of macrophages to the M1 phenotype and alleviates acute pancreatitis

Acute pancreatitis (AP) is an acute inflammatory disorder characterized by acinar cell death and inflammation. Multiple factors cause hyperglycemia after AP. Macrophage polarization is involved in tissue injury and repair, and is regulated by Notch signaling during certain inflammatory diseases. The present study explores the relationship among hyperglycemia, macrophage polarization, and Notch signaling during AP and the related mechanisms. A cerulein-induced AP model was established in FVB/N mice, and AP with hyperglycemia was initiated by injection of 50% concentration glucose. Tissue damage, Notch activity, and macrophage polarization were assessed in pancreatic tissues. The role of Notch signaling in macrophage polarization during AP was also assessed in vitro by co-culturing primary macrophages and pancreatic acinar cells, and establishing a lipopolysaccharide (LPS)-induced inflammatory model in RAW264.7 cells. Pancreatic acinar cells were damaged and proinflammatory factor levels were increased in pancreatic tissues during AP. The hyperglycemic conditions aggravated pancreatic injury, increased macrophage infiltration, promoted macrophage polarization towards an M1 phenotype, and led to excessive up-regulation of Notch activity. Inhibition of Notch signaling by DAPT or Notch1 knockdown decreased the proportion of M1 macrophages and reduced the production of proinflammatory factors, thus mitigating pancreatic injury. These findings suggest that hyperglycemia induces excessive Notch signaling after AP and further aggravates AP by promoting pancreatic macrophage polarization towards the M1 phenotype. The Notch signaling pathway is a potential target for the prevention and treatment of AP.

Milk Fat Globule Membrane Alleviates Short Bowel Syndrome-Associated Liver Injury in Rats Through Inhibiting Autophagy and NLRP3 Inflammasome Activation

Background

The milk fat globule membrane (MFGM), a tri-layer membrane structure surrounding the milk fat globule, has been shown to have immune-modulating properties. This study aimed to investigate the effects of MFGM supplementation in a rat model of short bowel syndrome (SBS) associated liver disease and its possible mechanisms.

Materials and Methods

Twenty one male Sprague-Dawley rats were randomly divided into three groups: Sham, SBS (underwent massive small bowel resection), and SBS+MFGM (SBS rats supplemented with 1.5 g/kg/d MFGM). Liver pathology, myeloperoxidase (MPO) staining, serum levels of aspartate aminotransferase (AST)/alanine aminotransferase (ALT), endotoxin concentration, protein expression of autophagy and nucleotide binding oligomerization domain, leucine-rich repeat and pyrin domain-containing protein 3 (NLRP3) pathway in the liver tissue were measured.

Results

Both SBS and SBS + MFGM groups had higher serum levels of ALT and liver endotoxin levels than the Sham group (P < 0.05), with no difference detected between each other. Compared with the SBS group, the SBS+MFGM group showed lower liver pathology scores of steatosis and inflammation, less MPO positive cells and reduced expressions of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), Caspase-1, interleukin (IL)-1β(P < 0.05) in the liver. Additionally, the expression of Beclin-1 and microtubule-associated protein1 light chain 3(LC3) B, the fluorescence intensity of NLRP3 and LC3B in the SBS + MFGM group were lower than the SBS group (P < 0.05). The LC3B expression was positively correlated with the NLRP3 level.

Conclusion

Enteral supplementation of MFGM help to alleviate liver injury in SBS rats, which might be related to inhibition of aberrant activation of autophagy and NLRP3 inflammasome pathways.

Kakonein restores hyperglycemia‐induced macrophage digestion dysfunction through regulation of cathepsin B‐dependent NLRP3 inflammasome activation

In hyperglycemia‐induced complications, macrophages play important roles in disease progression, and altered digestion is a key feature that dictates macrophage function. Recent evidence indicates that kakonein (Ka) possesses anti‐inflammatory activities for hyperglycemia‐induced complication. In this study, we established a mouse model of Nlrp3^+/+ and Nlrp3^−/− hyperglycemia and administering Ka, primary culture macrophages were tested by engulfing and digesting microbes. The role of macrophages in the cathepsin B–NLRP3 pathway involved in the mechanism of Ka in restoring macrophage digestion function was investigated using biochemical analyses, molecular biotechnology, and microbiology. Ka restored the function of macrophage digestion, which were same characterized by Nlrp3^−/− mice. Meanwhile, kakonein could decrease NLRP3 inflammasome products expression and NLRP3/ASC or NLRP3/Casp1 colocalization in macrophage. Interestingly, Ka suppressed inflammasome response not by reducing NLRP3 and ASC expression but by reducing cathepsin B release and activation. And Ka restored macrophage digestion and inhibited NLRP3 inflammasome activation consistent with cathepsin B inhibitor. It is concluded that Ka reduced the release of lysosomal cathepsin B and consequently inhibited NLRP3 inflammasome activation to prevent macrophage digestion. Hence, Ka may contribute to new targets for treatment of hyperglycemia‐associated dysfunction of macrophage digestion and development of innovative drugs.

Induction of osteoclast formation by LOX mutant (LOXG473A) through regulation of autophagy

Background

Lysyl oxidase (LOX) has been identified to modulate osteoclast activity, so we explored the role of LOX_G473A, the highest frequency single nucleotide polymorphism in LOX, in osteoclast formation and its potential relationship to autophagy.

Methods

The ability of the LOX mutant, LOX_G473A, to promote autophagy and osteoclast formation was evaluated in the pre-osteoclast cell line RAW264.7. Furthermore, autophagy-related protein expression and autophagosomes were detected by western blot and electron microscopy, respectively. Simultaneously, osteoclast formation and resorption ability were also detected using TRAP staining assay and bone resorption assay. In addition, the osteoclast-related proteins and mRNAs, as well as p-AMPKα and p-mTOR proteins, were further evaluated by western blot and qPCR assays.

Results

Autophagy inhibitor 3-MA suppressed the Beclin-1 and ATG5 protein levels and the ratio of LC3-II to LC3-I, as well as autophagosome formation in RAW264.7 transfected with the MUT plasmid and enhanced p62 protein expression. Simultaneously, 3-MA also reduced osteoclast formation and resorption, as well as the F-actin ring level of osteoclasts. In addition, 3-MA inhibited osteoclast-related protein and mRNA expression, including NFATC1, ACP5, CTSK. And the autophagy-related pathway protein p-AMPKα was increased and p-mTOR was reduced by 3-MA treatment. However, autophagy agonist RAPA reversed the effect of 3-MA on RAW264.7 with LOX_G473A mutation, indicating that promoting autophagy could enhance the ability of LOX_G473A to induce osteoclast formation.

Conclusions

LOX mutant (LOX_G473A) might promote osteoclast formation for RAW264.7 by enhancing autophagy via the AMPK/mTOR pathway, which is a new direction for bone disease research.

Omarigliptin ameliorated high glucose-induced nucleotide oligomerization domain-like receptor protein 3 (NLRP3) inflammasome activation through activating adenosine monophosphate-activated protein kinase α (AMPKα) in renal glomerular endothelial cells

Diabetic nephropathy (DN) is a complication of diabetes that induces the development of end-stage renal disease (ESRD). The pathogenesis of DN is reported to be closely related to the activation of the NOD-like receptor 3 (NLRP3) inflammasome in renal glomerular endothelial cells. Omarigliptin is a novel dipeptidyl peptidase-4 (DPP-4) inhibitor developed for the management of type II diabetes, it has been recently reported to possess a significant anti-inflammatory property. This study aims to explore the potential therapeutic effects of Omarigliptin on DN. We established an in vitro injury model in human renal glomerular endothelial cells (HrGECs) using high glucose (HG). The severe cytotoxicity and increased oxidative stress in HrGECs induced by HG were pronouncedly reversed by the introduction of Omarigliptin. Furthermore, the activated NLRP3 inflammasome and the excessive production of interleukin 18 (IL-18) and interleukin 1β (IL-1β) in HrGECs induced by incubation with HG were pronouncedly reversed by the introduction of Omarigliptin, accompanied by the activation of the AMPK/mTOR signaling pathway. After the co-administration of the adenosine monophosphate-activated protein kinase α (AMPKα) inhibitor, compound C, the protective effects of Omarigliptin against HG-induced NLRP3 inflammasome activation and production of pro-inflammatory factors were dramatically abolished. Taken together, our data revealed that Omarigliptin ameliorated HG-induced inflammation in renal glomerular endothelial cells through suppressing NLRP3 inflammasome activation mediated by AMPKα.

Fisetin mitigates hepatic ischemia-reperfusion injury by regulating GSK3β/AMPK/NLRP3 inflammasome pathway

BACKGROUND

Hepatic ischemia-reperfusion (I/R) injury (IRI) represents a crucial challenge in liver transplantation. Fisetin has anti-inflammatory, anti-aging and anti-oxidative properties. This study aimed to examine whether fisetin mitigates hepatic IRI and examine its underlying mechanisms.

METHODS

Sham or warm hepatic I/R operated mice were pretreated with fisetin (5, 10 or 20 mg/kg). Hepatic histological assessments, TUNEL assays and serum aminotransferase measurements were performed. An in vitro hypoxia/reoxygenation (H/R) model using RAW264.7 macrophages pretreated with fisetin (2.5, 5 or 10 µmol/L) was also used. Serum and cell supernatant concentrations of interleukin-1β (IL-1β), IL-18 and tumor necrosis factor-α (TNF-α) were determined by enzyme-linked immunosorbent assay (ELISA). Protein levels of p-GSK3β, p-AMPK and NLR family pyrin domain-containing 3 (NLRP3)-associated proteins were detected by Western blotting.

RESULTS

Compared with the I/R group, fisetin pretreatment reduced pathological liver damage, serum aminotransferase levels, serum concentrations of IL-1β, IL-18 and TNF-α in the murine IRI model. Fisetin also reduced the expression of NLRP3 inflammasome-associated proteins (NLRP3, cleaved caspase-1, IL-1β and IL-18) in I/R-operated liver. The experiments in vitro showed that fisetin decreased the release of IL-1β, IL-18 and TNF-α, and reduced the expression of NLRP3 inflammasome-associated proteins in H/R-treated RAW264.7 cells. Moreover, fisetin increased the expressions of p-GSK3β and p-AMPK in both models, indicating that its anti-inflammatory effects were dependent on GSK3β/AMPK signaling. The anti-inflammatory effects of fisetin were partially inhibited by the AMPK specific inhibitor compound C.

CONCLUSIONS

Fisetin showed protective effects against hepatic IRI, countering inflammatory responses through mediating the GSK3β/AMPK/NLRP3 inflammasome pathway.

Inflammasomes and Fibrosis

Fibrosis is the final common pathway of inflammatory diseases in various organs. The inflammasomes play an important role in the progression of fibrosis as innate immune receptors. There are four main members of the inflammasomes, such as NOD-like receptor protein 1 (NLRP1), NOD-like receptor protein 3 (NLRP3), NOD-like receptor C4 (NLRC4), and absent in melanoma 2 (AIM2), among which NLRP3 inflammasome is the most studied. NLRP3 inflammasome is typically composed of NLRP3, ASC and pro-caspase-1. The activation of inflammasome involves both "classical" and "non-classical" pathways and the former pathway is better understood. The "classical" activation pathway of inflammasome is that the backbone protein is activated by endogenous/exogenous stimulation, leading to inflammasome assembly. After the formation of "classic" inflammasome, pro-caspase-1 could self-activate. Caspase-1 cleaves cytokine precursors into mature cytokines, which are secreted extracellularly. At present, the "non-classical" activation pathway of inflammasome has not formed a unified model for activation process. This article reviews the role of NLRP1, NLRP3, NLRC4, AIM2 inflammasome, Caspase-1, IL-1β, IL-18 and IL-33 in the fibrogenesis.

New Insights Into the Role of Autophagy in Liver Surgery in the Setting of Metabolic Syndrome and Related Diseases

Visceral obesity is an important component of metabolic syndrome, a cluster of diseases that also includes diabetes and insulin resistance. A combination of these metabolic disorders damages liver function, which manifests as non-alcoholic fatty liver disease (NAFLD). NAFLD is a common cause of abnormal liver function, and numerous studies have established the enormously deleterious role of hepatic steatosis in ischemia-reperfusion (I/R) injury that inevitably occurs in both liver resection and transplantation. Thus, steatotic livers exhibit a higher frequency of post-surgical complications after hepatectomy, and using liver grafts from donors with NAFLD is associated with an increased risk of post-surgical morbidity and mortality in the recipient. Diabetes, another MetS-related metabolic disorder, also worsens hepatic I/R injury, and similar to NAFLD, diabetes is associated with a poor prognosis after liver surgery. Due to the large increase in the prevalence of MetS, NAFLD, and diabetes, their association is frequent in the population and therefore, in patients requiring liver resection and in potential liver graft donors. This scenario requires advancement in therapies to improve postoperative results in patients suffering from metabolic diseases and undergoing liver surgery; and in this sense, the bases for designing therapeutic strategies are in-depth knowledge about the molecular signaling pathways underlying the effects of MetS-related diseases and I/R injury on liver tissue. A common denominator in all these diseases is autophagy. In fact, in the context of obesity, autophagy is profoundly diminished in hepatocytes and alters mitochondrial functions in the liver. In insulin resistance conditions, there is a suppression of autophagy in the liver, which is associated with the accumulation of lipids, being this is a risk factor for NAFLD. Also, oxidative stress occurring in hepatic I/R injury promotes autophagy. The present review aims to shed some light on the role of autophagy in livers undergoing surgery and also suffering from metabolic diseases, which may lead to the discovery of effective therapeutic targets that could be translated from laboratory to clinical practice, to improve postoperative results of liver surgeries when performed in the presence of one or more metabolic diseases.

Doxepin Exacerbates Renal Damage, Glucose Intolerance, Nonalcoholic Fatty Liver Disease, and Urinary Chromium Loss in Obese Mice

Doxepin is commonly prescribed for depression and anxiety treatment. Doxepin-related disruptions to metabolism and renal/hepatic adverse effects remain unclear; thus, the underlying mechanism of action warrants further research. Here, we investigated how doxepin affects lipid change, glucose homeostasis, chromium (Cr) distribution, renal impairment, liver damage, and fatty liver scores in C57BL6/J mice subjected to a high-fat diet and 5 mg/kg/day doxepin treatment for eight weeks. We noted that the treated mice had higher body, kidney, liver, retroperitoneal, and epididymal white adipose tissue weights; serum and liver triglyceride, alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, and creatinine levels; daily food efficiency; and liver lipid regulation marker expression. They also demonstrated exacerbated insulin resistance and glucose intolerance with lower Akt phosphorylation, GLUT4 expression, and renal damage as well as higher reactive oxygen species and interleukin 1 and lower catalase, superoxide dismutase, and glutathione peroxidase levels. The treated mice had a net-negative Cr balance due to increased urinary excretion, leading to Cr mobilization, delaying hyperglycemia recovery. Furthermore, they had considerably increased fatty liver scores, paralleling increases in adiponectin, FASN, PNPLA3, FABP4 mRNA, and SREBP1 mRNA levels. In conclusion, doxepin administration potentially worsens renal injury, nonalcoholic fatty liver disease, and diabetes.

Targeting the NLRP3 inflammasome as new therapeutic avenue for inflammatory bowel disease

The incidence and prevalence of inflammatory bowel disease (IBD) are increasing worldwide. Current approved medication for IBD treatment in the clinic mainly includes corticosteroids and neutralization antibodies to pro-inflammatory cytokines. However, drug resistance and severe side effect hinder long-term efficacy of these agents. The NOD-like receptor family pyrin domain containing protein 3 (NLRP3) is exclusively expressed in several inflammatory and autoimmune diseases. Excessive expression, aberrant activation, polymorphism, and gain-of-function mutation of the NLRP3 inflammasome contribute to IBD pathogenesis. In this article, we summarize the regulatory factors to NLRP3, and review recently developed NLRP3 inhibitors and their preclinical and clinical applications in treating inflammatory and autoimmune diseases. We present our views on the therapeutic potential of NLRP3 inhibitors as emerging therapeutic avenue for IBD.

Specific NLRP3 inflammasome inhibitors: promising therapeutic agents for inflammatory diseases

Innate immunity serves as a first line of defence against danger signals, invading pathogens and microbes. The inflammasomes, as pattern recognition receptors, sense these danger signals to initiate pro-inflammatory cascades. The nucleotide-binding domain leucine-rich repeat and pyrin domain containing receptor 3 (NLRP3) inflammasome is the most well characterised inflammasome, and its aberrant activation is implicated in many inflammatory diseases. In the past decade, targeting the NLRP3 inflammasome has become an emerging strategy for inflammatory diseases. To avoid off-target immunosuppressive effects, specific NLRP3 inhibitors have been developed and show promising therapeutic effects. This review discusses the therapeutic effects and clinical perspectives of specific NLRP3 inhibitors, as well as recent progress in the development of these inhibitors for the treatment of inflammatory diseases.

Eva1a inhibits NLRP3 activation to reduce liver ischemia-reperfusion injury via inducing autophagy in kupffer cells

Ischemia-reperfusion(IR) injury is one of the main complications of liver transplantation and partial hepatectomy. Innate immunity mediated by kupffer cells plays an important role in it. In this study, we focused on evaluating the intrinsic relationship between the autophagy induction of kupffer cells and the activation of NLRP3 inflammasomes caused by liver ischemia-reperfusion. Pre-depletion of kupffer cells can aggravate inflammation and tissue damage within 24 h after IR.Enhancing the autophagy of kupffer cells can inhibit the activation of NLRP3 caused by IR, and inhibiting autophagy can induce the secretion of IL1β dependent on NLRP3 activation.Eva1a is up-regulated by the inflammatory cascade activated by IR.Knockdown of Eva1a in vivo on the one hand will aggravate IR inflammation, increase the production of TNF-α, IL-1β and inhibit the secretion of IL-10.On the other hand, it will aggravate the liver histological damage. Knockout of Eva1a induces ASC activation and cleavage of caspase1 and IL1β in an NLRP3-dependent manner, which is closely related to the function of blocking Eva1a to promote autophagosome formation.We further found that knockdown of ATG16L1 will reverse the more formation of autophagosomes induced by overexpression of Eva1a, whereas knockdown of ATG16L1 did not further reduce the formation of autophagosomes inhibited by siEva1a. We also found that the addition of siATG7, siATG5 and siATG12 would reverse the IR autophagy of liver induced by overexpression of Eva1a, but inhibition of the Beclin1-Vps34 pathway did not significantly reverse the effect of overexpression of Eva1a.These prove that Eva1a and ATG16L1 may work together in the liver IR model to actively induce the formation of autophagosomes and be independent from the beclin1-vps34-induced autophagy pathway to limit the excessive activation of IR inflammation. Our study provides brand new insights into the mechanism of liver macrophages in the progression of inflammation in the context of liver ischemia-reperfusion injury.

Skimmin protects diabetic cardiomyopathy in streptozotocin-induced diabetic rats

Skimmin, a natural coumarin derivate, has been showed to be protective against experimental diabetic nephropathy; however, its protective effect on diabetic cardiomyopathy (DCM) is not clarified. By using in vitro and in vivo models, we investigated skimmin's protective effect on impaired heart tissues in DCM. DCM was induced by streptozotocin (STZ, 60 mg/kg) using Sprague Dawley rats, and diabetic rats were treated with either skimmin (15 or 30 mg/kg) or the vehicle for 16 weeks, and normal rats were used as a control. Hematoxylin and eosin and Masson's trichrome staining were performed to evaluate the cardiac histopathology, and the oxidative stress and proinflammation cytokines in heart tissues were measured. The protein levels of key mediators in fibrosis, pyroptosis, and autophagy in heart tissues were investigated using western blotting. In vitro, primary neonatal cardiomyocytes were treated with skimmin (2 and 10 μM) under stimulation by high glucose (30 mM) and low glucose (5 mM) respectively, and the molecular mechanisms on pyroptosis and autophagy were studied. Compared to the vehicle-treated DCM group, skimmin treatment significantly improved the ejection fraction and fractional shortening of the left ventricle and reduced the oxidative stress by increasing the glutathione level and activity of superoxide dismutase and catalase. Skimmin also reduced cardiac fibrosis, and decreased proinflammation cytokines in cardiac tissues. Mechanism studies showed skimmin may enhance the autophagy and ameliorate NLRP3 inflammasome activation to play a protective role in DCM. This study, for the first time, indicates that skimmin might be a promising lead compound for DCM.

Autophagy in liver diseases

Autophagy is the liver cell energy recycling system regulating a variety of homeostatic mechanisms. Damaged organelles, lipids and proteins are degraded in the lysosomes and their elements are re-used by the cell. Investigations on autophagy have led to the award of two Nobel Prizes and a health of important reports. In this review we describe the fundamental functions of autophagy in the liver including new data on the regulation of autophagy. Moreover we emphasize the fact that autophagy acts like a two edge sword in many occasions with the most prominent paradigm being its involvement in the initiation and progress of hepatocellular carcinoma. We also focused to the implication of autophagy and its specialized forms of lipophagy and mitophagy in the pathogenesis of various liver diseases. We analyzed autophagy not only in well studied diseases, like alcoholic and nonalcoholic fatty liver and liver fibrosis but also in viral hepatitis, biliary diseases, autoimmune hepatitis and rare diseases including inherited metabolic diseases and also acetaminophene hepatotoxicity. We also stressed the different consequences that activation or impairment of autophagy may have in hepatocytes as opposed to Kupffer cells, sinusoidal endothelial cells or hepatic stellate cells. Finally, we analyzed the limited clinical data compared to the extensive experimental evidence and the possible future therapeutic interventions based on autophagy manipulation.

NLRP3 inflammasome inhibitor CY-09 reduces hepatic steatosis in experimental NAFLD mice

AIMS

Non-alcoholic fatty liver disease (NAFLD) has become one of the most common chronic liver diseases. The NOD-like receptor protein 3 (NLRP3) inflammasome was suggested to be involved in the pathogenesis of NAFLD. A small-molecule named CY-09 is a new selective and direct inhibitor of the NLRP3 inflammasome. We aimed to investigate whether CY-09 is effective for the treatment of NAFLD in a high-fat diet (HFD)-induced mouse model.

METHODS

Twenty mice were fed by HFD for 14 weeks, and then were randomly assigned into two groups: (1) control group receiving dimethylsulfoxide (DMSO) solution; (2) CY-09 group receiving CY-09 injection. In an 8-week follow-up, oral glucose tolerance test (OGTT) and homeostasis model assessment of insulin resistance (HOMA-IR) were used to measure glucose metabolism. Liver steatosis was evaluated by the NAFLD activity score (NAS) and deemed as the primary outcome.

RESULTS

The body weight in CY-09 group was significantly lower than the DMSO control group on 27 weeks (41.0 ± 3.5 g vs. 49.7 ± 5.2 g, P = 0.014). The area under the curve (AUC) of OGTT was less in CY-09 group than that in DMSO group (35.81 ± 6.79 vs. 22.91 ± 2.58 mmol/L·hr, P = 0.004), as well as HOMA-IR (14.36 ± 3.89 vs. 8.82 ± 2.04 mmol.mIU.L-2, P = 0.023). Microscopically, liver lipid droplets dramatically improved and significantly lower NAS was observed in CY-09 group (8.25 ± 1.26 vs. 3.20 ± 0.45, P < 0.001).

CONCLUSION

CY-09 reduces hepatic steatosis in experimental NAFLD mice and CY-09 may be a potential therapeutic drug of NAFLD in clinical practice.

Liver Fibrosis in Non-alcoholic Fatty Liver Disease: From Liver Biopsy to Non-invasive Biomarkers in Diagnosis and Treatment

An increasing percentage of people have or are at risk to develop non-alcoholic fatty liver disease (NAFLD) worldwide. NAFLD comprises different stadia going from isolated steatosis to non-alcoholic steatohepatitis (NASH). NASH is a chronic state of liver inflammation that leads to the transformation of hepatic stellate cells to myofibroblasts. These cells produce extra-cellular matrix that results in liver fibrosis. In a normal situation, fibrogenesis is a wound healing process that preserves tissue integrity. However, sustained and progressive fibrosis can become pathogenic. This process takes many years and is often asymptomatic. Therefore, patients usually present themselves with end-stage liver disease e.g., liver cirrhosis, decompensated liver disease or even hepatocellular carcinoma. Fibrosis has also been identified as the most important predictor of prognosis in patients with NAFLD. Currently, only a minority of patients with liver fibrosis are identified to be at risk and hence referred for treatment. This is not only because the disease is largely asymptomatic, but also due to the fact that currently liver biopsy is still the golden standard for accurate detection of liver fibrosis. However, performing a liver biopsy harbors some risks and requires resources and expertise, hence is not applicable in every clinical setting and is unsuitable for screening. Consequently, different non-invasive diagnostic tools, mainly based on analysis of blood or other specimens or based on imaging have been developed or are in development. In this review, we will first give an overview of the pathogenic mechanisms of the evolution from isolated steatosis to fibrosis. This serves as the basis for the subsequent discussion of the current and future diagnostic biomarkers and anti-fibrotic drugs.

Protective Role of Loranthus regularis against Liver Dysfunction, Inflammation, and Oxidative Stress in Streptozotocin Diabetic Rat Model

Earlier studies revealed the potential therapeutic values of Loranthus regularis (L. regularis). This study evaluated Loranthus regularis (L. regularis) extract systemic antidiabetic effects and benefits against diabetic hepatocellular injuries through antioxidant and anti-inflammatory pathways using the streptozotocin (STZ) model in Wistar albino rats. After diabetes induction, animals were orally treated with L. regularis extract for 4 weeks. Serum levels of glucose, insulin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol (TC), total triglycerides (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) were estimated. Furthermore, tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), caspase-3, nitric oxide (NO), and prostaglandin E-2 (PGE-2) were estimated in serum. In liver, thiobarbituric acid reactive substances (TBARSs) and reduced glutathione (GSH) as well as the proinflammatory cytokines and enzymatic activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reeducates (GR), and glutathione-S-transferase (GST) were assayed. Finally, the degree of hepatic tissue damage was evaluated histologically. Treatment of the diabetic rats with L. regularis extract markedly reduced the elevated serum levels of glucose, ALT, AST, TC, TG, LDL, TNF-α, IL-1β, IL-6, caspase-3, NO, and PGE-2. L. regularis extract also improved serum levels of insulin and HDL. The elevated TBARS, TNF-α, IL-1β, and IL-6 levels in hepatic tissue of diabetic animals were reduced by L. regularis. Moreover, L. regularis extract significantly restored the diminished hepatic GSH level and enzymatic activities of SOD, CAT, GPx, GR, and GST in diabetic animals. The biochemical protective effects of L. regularis were associated with improved histological hepatocellular integrity and architecture. Taken together, L. regularis has therapeutic effects against diabetic-induced hepatic complications. The restored liver functions and cellular damage might be mediated through free radicals scavenging and proinflammatory cytokine inhibition.

Lychee seed polyphenol inhibits Aβ-induced activation of NLRP3 inflammasome via the LRP1/AMPK mediated autophagy induction

Emerging evidence indicates that the enhancement of microglial autophagy inhibits the NLRP3 inflammasome mediated neuroinflammation in Alzheimer's disease (AD). Meanwhile, low density lipoprotein receptor-related protein 1 (LRP1) highly expressed in microglia is able to negatively regulate neuroinflammation and positively regulate autophagy. In addition, we have previously reported that an active lychee seed fraction enriching polyphenol (LSP) exhibits anti-neuroinflammation in Aβ-induced BV-2 cells. However, its molecular mechanism of action is still unclear. In this study, we aim to investigate whether LSP inhibits the NLRP3 inflammasome mediated neuroinflammation and clarify its molecular mechanism in Aβ-induced BV-2 cells and APP/PS1 mice. The results showed that LSP dose- and time-dependently activated autophagy by increasing the expression of Beclin 1 and LC3II in BV-2 cells, which was regulated by the upregulation of LRP1 and its mediated AMPK signaling pathway. In addition, both the Western blotting and fluorescence microscopic results demonstrated that LSP could significantly suppress the activation of NLRP3 inflammasome by inhibiting the expression of NLRP3, ASC, the cleavage of caspase-1, and the release of IL-1β in Aβ(1-42)-induced BV-2 cells. In addition, the siRNA LRP1 successfully abolished the effect of LSP on the activation of AMPK and its mediated autophagy, as well as the inhibition of NLRP3 inflammasome. Furthermore, LSP rescued PC-12 cells which were induced by the conditioned medium from Aβ(1-42)-treated BV-2 cells. Moreover, LSP improved the cognitive function and inhibited the NLRP3 inflammasome in APP/PS1 mice. Taken together, LSP inhibited the NLRP3 inflammasome-mediated neuroinflammation in the in vitro and in vivo models of AD, which was closely associated with the LRP1/AMPK-mediated autophagy. Thus, the findings from this study further provide evidences for LSP serving as a potential drug for the treatment of AD in the future.

Diabetes induces hepatocyte pyroptosis by promoting oxidative stress-mediated NLRP3 inflammasome activation during liver ischaemia and reperfusion injury

Background

Although diabetes mellitus has been reported to aggravate liver ischaemia and reperfusion (IR) injury, the basic mechanism remains largely unknown. The object of the present study was to determine the role of oxidative stress and hepatocellular pyroptosis in liver IR injury in diabetic mice.

Methods

Db/db and C57BL/6 mice at 8 weeks of age were subjected to liver IR injury. Liver injury and hepatocyte cell death were analyzed. A NOD-like receptor family pyrin domain-containing 3 protein (NLRP3) inflammasome antagonist (CY09) and a reactive oxygen species (ROS) antagonist (N-Acetyl-L-cysteine, NAC) were used to determine the role of ROS-mediated hepatocellular pyroptosis in diabetic mice post-IR.

Results

Aggravated liver IR injury was found in db/db mice compared to C57BL/6 control mice, as demonstrated by increased serum alanine aminotransaminase (ALT) and aspartate aminotransaminase (AST) levels, liver architecture damage and Suzuki scores. Interestingly, IR induces the pyroptosis of hepatocytes in db/db mice, as evidenced by enhanced NLRP3 inflammasome activation, increased numbers of terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL)-positive hepatocytes and increased gene expression of interleukin-1β (IL-1β) and IL-18 in livers post-IR. The inhibitory effect of CY09, an NLRP3 antagonist, efficiently abrogated the exacerbation effects of diabetes on liver IR injury in db/db mice. Furthermore, increased ROS expression was detected in db/db mice compared to control mice after IR. ROS scavenging by NAC pretreatment markedly inhibited hepatocellular NLRP3 inflammasome activation and pyroptosis in the db/db mice post-IR, indicating that ROS play an essential role in mediating hepatocyte pyroptosis in the setting of diabetes mellitus.

Conclusions

Our results demonstrate that diabetes induces hepatocyte pyroptosis by promoting oxidative stress-mediated NLRP3 inflammasome activation during liver IR injury. Strategies targeting ROS and NLRP3 inflammasome activation would be beneficial for preventing liver IR injury in diabetic patients.