Liver Proinflammatory Cytokines Research Articles

Succinic Acid Ameliorates Concanavalin A-Induced Hepatitis by Altering the Inflammatory Microenvironment and Expression of BCL-2 Family Proteins.

Autoimmune hepatitis (AIH) is a severe immune-mediated inflammatory liver disease that currently lacks feasible drug treatment methods. Our study aimed to evaluate the protective effect of succinic acid against AIH and provide a reliable method for the clinical treatment of AIH. We performed an in vivo study of the effects of succinic acid on concanavalin A (ConA)-induced liver injury in mice. We examined liver transaminase levels, performed hematoxylin and eosin (HE) staining, and observed apoptotic phenotypes in mice. We performed flow cytometry to detect changes in the number of neutrophils and monocytes, and used liposomes to eliminate the liver Kupffer cells and evaluate their role. We performed bioinformatics analysis, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and western blotting to detect mitochondrial apoptosis-induced changes in proteins from the B-cell lymphoma 2(Bcl-2) family. Succinic acid ameliorated ConA-induced AIH in a concentration-dependent manner, as reflected in the survival curve. HE and TUNEL staining and terminal deoxynucleotidyl transferase dUTP nick end labeling revealed decreased alanine transaminase and aspartate aminotransferase levels, and reduced liver inflammation and apoptosis. RT-qPCR and enzyme-linked immunosorbent assay revealed that succinic acid significantly reduced liver pro-inflammatory cytokine levels. Flow cytometry revealed significantly decreased levels of liver neutrophils. Moreover, the protective effect of succinic acid disappeared after the Kupffer cells were eliminated, confirming their important role in the effect. Bioinformatics analysis, RT-qPCR, and western blotting showed that succinic acid-induced changes in proteins from the Bcl-2 family involved mitochondrial apoptosis, indicating the molecular mechanism underlying the protective effect of succinic acid. Succinic acid ameliorated ConA-induced liver injury by regulating immune balance, inhibiting pro-inflammatory factors, and promoting anti-apoptotic proteins in the liver. This study provides novel insights into the biological functions and therapeutic potential of succinic acid in the treatment of autoimmune liver injury.

Hesperidin alleviates inflammation in the metabolic syndrome model

In metabolic syndrome, activated inflammatory signaling pathways trigger the release of proinflammatory cytokines. Nowadays, the use of natural bioactive compounds is trending as an alternative method for the treatment and management of metabolic syndrome. This study aimed to assess the potential effects of hesperidin in the metabolic syndrome model by analyzing the proinflammatory and anti-inflammatory cytokines in serum and liver. Rats were divided into 4 groups: Control (Rats were fed a standard chow diet and water ad libitum), hesperidin [Rats were fed hesperidin supplemented standard chow diet (1%, 10 g/kg feed) and water ad libitum] metabolic syndrome (Rats were fed standard chow diet with 10% fructose-added-drinking-water), and metabolic syndrome + hesperidin (Rats were fed a hesperidin-added standard chow diet (1%, 10 g/kg) with 10% fructose-added-drinking-water). Rats were sacrificed under ketamine/xylazine anesthesia, blood was obtained and liver tissues were removed. Tumor necrosis factor-alpha, interleukin-1 beta, interleukin-6, interleukin-10, and transforming growth factor-beta in the serum and liver were measured by enzyme-linked immunosorbent assay. In the metabolic syndrome group, higher tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6, but lower serum and liver interleukin-10 and transforming growth factor-beta were found in the serum and liver compared to the control group. In addition, in the metabolic syndrome + hesperidin group lower interleukin-1 beta and interleukin-6 but higher serum interleukin-10 and transforming growth factor-beta were found in the serum and liver compared to the metabolic syndrome groups. Consequently, hesperidin suppressed the serum and liver proinflammatory cytokine response and stimulated the anti-inflammatory cytokine response in the metabolic syndrome rat model.

Novel Lauric Acid-Butyric Structural Lipid Inhibits Inflammation: Small Intestinal Microbes May Be Important Mediators.

Butyric acid (C4) and lauric acid (C12) are recognized as functional fatty acids, while the health benefits of the structural lipids they constitute remain unclear. In this study, lauric acid-butyric structural lipid (SLBL ) is synthesized through ultrasound-assisted enzyme-catalyzed acidolysis and its health benefits are evaluated in a high-fat diet-induced obesity mouse model. SLBL and its physical mixture (MLBL ) do not significantly inhibit obesity in mice. However, SLBL treatment increases the ratio of n3/n6 fatty acids in the liver and improves obesity-induced hepatic lipid metabolism disorders. Furthermore, the expression of liver pro-inflammatory cytokines (interleukin [IL]-6, IL-1β, TNF-α) are significantly suppressed by SLBL , while the expression of anti-inflammatory cytokine (IL-10) is increased. Moreover, SLBL ameliorates the dysbiosis of small intestinal microbes induced by high-fat diet and regulates microbial community structure to be close to the control group. Especially, SLBL significantly alleviates the high-fat diet-induced decrease in Dubosiella and Bifidobacterium abundance. Correlation analysis reveals that SLBL treatment increases the abundance of microorganisms with potential anti-inflammatory function and decreases the abundance of potentially pathogenic bacteria. In all, small intestinal microbes may be a significant bridge for the positive anti-inflammatory effects of SLBL , while the exact mechanism remains to be clarified.

Veronica persica ameliorates acetaminophen-induced murine hepatotoxicity via attenuating oxidative stress and inflammation

Excess acetaminophen (APAP) commonly causes severe acute liver injury (ALI), characterized by oxidative stress, pro-inflammatory responses, and hepatocyte damage. Veronica persica (VP) is a traditional medicine with antioxidant and anti-inflammatory properties. There is a paucity of information on its medicinal value, especially its potential mechanisms for alleviating ALI. This study aimed to clarify the ameliorative effects and intracellular mechanisms of VP on APAP-induced ALI via attenuating oxidative stress and inflammation. Mice were given VP for 7 days before exposure to APAP (300 mg/kg). The HPLC and radical scavenging assay found that VP contains 12 phenolic acids and 6 flavonoids, as well as show robust antioxidant capacity. In the APAP-induced ALI model, pre-treatment with VP significantly reduces APAP-induced hepatotoxicity by observing improved hepatocyte pathological injury and further confirmed by serum biochemical indicator. Also, the reduction of TUNEL-positive regions and the regulation of Bcl-2-associated X protein indicated that VP attenuates hepatocytotoxicity. Moreover, VP pre-intervention inhibits the formation of liver pro-inflammatory cytokines, the expression of inflammatory response genes, and increases in myeloperoxidase (MPO) in APAP-exposed mice. The elevated reduced glutathione (GSH) levels and decreased oxidative stress markers indicate that VP reduces APAP-promoted oxidative stress. Further study revealed that VP inhibited the phosphorylation of NF-κB/STAT3 cascade, blocked ERK and JNK phosphorylation, and activated AMP-activated protein kinase (AMPK). To sum up, this study demonstrated that VP exists hepatoprotective abilities on APAP-induced ALI, primarily by suppressing the phosphorylation of NF-κB/STAT3 cascade and ERK-JNK and inducing AMPK activation to alleviate oxidative stress and inflammation.

Hepatoprotective effects of Nigella Sativa oil against acrylamide-induced liver injury in rats

Acrylamide (AA) is a heat-induced carcinogen founds in some foods due to cooking or other thermal processes. This study was designed to investigate the possible protective efficacy of Nigella sativa essential oil against acrylamide-induced liver toxicity. Four groups of 32 male Wistar albino rats were formed. The control group was fed ad libitum. Acrylamide was administered to the rats in Group AA at a daily dose of 40 mg/kg by gavage. Nigella sativa essential oil was administered intraperitoneally at a dose of 10mg/kg to the rats in Group NS. In Group AA+NS, daily applications of acrylamide and Nigella sativa essential oil were applied simultaneously as mentioned above. The trial period lasted 15 days. While acrylamide statistically increased MDA levels in liver tissue (P<0.05), (146.13 %) and decreased GSH and SOD activity statistically (P<0.05), (55.28% and 40.46%). In addition, liver proinflammatory cytokine levels increased due to acrylamide administration (P<0.05), [TNF-α (78.17%), IL-6 (76.08%)], anti-inflammatory cytokine levels (P<0.05), [IL-10 (61.16%)] decreased. Co-administration of Nigella sativa essential oil with acrylamide significantly reduced oxidative stress and pro-inflammatory cytokine levels in liver tissues (P<0.05). In conclusion, our findings highlighted the potential therapeutic role of Nigella sativa essential oil in preventing acrylamide-induced hepatotoxicity.

Parabacteroides distasonis uses dietary inulin to suppress NASH via its metabolite pentadecanoic acid

Non-alcoholic steatohepatitis (NASH) is the severe form of non-alcoholic fatty liver disease, and is characterized by liver inflammation and fat accumulation. Dietary interventions, such as fibre, have been shown to alleviate this metabolic disorder in mice via the gut microbiota. Here, we investigated the mechanistic role of the gut microbiota in ameliorating NASH via dietary fibre in mice. Soluble fibre inulin was found to be more effective than insoluble fibre cellulose to suppress NASH progression in mice, as shown by reduced hepatic steatosis, necro-inflammation, ballooning and fibrosis. We employed stable isotope probing to trace the incorporation of 13C-inulin into gut bacterial genomes and metabolites during NASH progression. Shotgun metagenome sequencing revealed that the commensal Parabacteroides distasonis was enriched by 13C-inulin. Integration of 13C-inulin metagenomes and metabolomes suggested that P. distasonis used inulin to produce pentadecanoic acid, an odd-chain fatty acid, which was confirmed in vitro and in germ-free mice. P. distasonis or pentadecanoic acid was protective against NASH in mice. Mechanistically, inulin, P. distasonis or pentadecanoic acid restored gut barrier function in NASH models, which reduced serum lipopolysaccharide and liver pro-inflammatory cytokine expression. Overall this shows that gut microbiota members can use dietary fibre to generate beneficial metabolites to suppress metabolic disease.

Alternative pathway of bile acid biosynthesis contributes to ameliorate NASH after induction of NAMPT/NAD+/SIRT1 axis

Non-alcoholic steatohepatitis (NASH) is emerging as a serious liver disorder characterized by hepatic steatosis and liver inflammation. Nicotinamide adenine dinucleotide (NAD+) and NAD+-dependent deacetylase, SIRT1, play important roles in lipid metabolism in non-alcoholic fatty liver disease (NAFLD). However, their effects on liver inflammation and homeostasis of bile acids (BAs), the extensively proved pathophysiological actors in NASH, have not been fully understood. NASH animal model was induced by a methionine-choline-deficient (MCD) diet in C57BL/6J mice and intraperitoneally injected with NAD+ precursor, an agonist of upstream rate-limiting enzyme NAMPT or downstream SIRT1, or their vehicle solvents. Free fatty acid (FFA) was applied to HepG2 cells to construct the cell model. Induction of NAMPT/NAD+/SIRT1 axis could remarkably alleviate the aggravated inflammation in the liver of NASH mice, accompanied by decreased levels of total BAs throughout the enterohepatic system and a switch of BA synthesis from the classic pathway to the alternative pathway, resulting in less production of pro-inflammatory 12-OH BAs. The expressions of key enzymes including cyp7a1, cyp8b1, cyp27a1 and cyp7b1 in BA synthesis were significantly modulated after NAMPT/NAD+/SIRT1 axis induction in both animal and cell models. The levels of pro-inflammatory cytokines in liver were significantly negatively correlated with the intermediates in NAD+ metabolism, which may also be related to their regulation on BA homeostasis. Our results indicated that induction of NAMPT/NAD+/SIRT1 axis may be a potential therapeutic strategy for NASH or its complications related with BAs.

Evaluation of a Functional Craft Wheat Beer Fermented with Saccharomyces cerevisiae UFMG A-905 to treat Salmonella Typhimurium infection in mice.

Functional foods containing probiotics are generally administered as dairy products. Non-dairy beverages are another possibility, but probiotic functionality must be confirmed in such vehicles. In the present study, a craft wheat beer brewed with the probiotic yeast Saccharomyces cerevisiae UFMG A-905 (905) was evaluated in a murine model of Salmonella Typhimurium infection. Unfiltered or filtered beer brewed with 905, a commercial wheat beer used as a negative control, or saline were administered orally to mice before and during oral S. Typhimurium challenge. High fecal levels of yeast were only counted in mice treated with the unfiltered 905 beer, which also had reduced mortality and body weight loss due to S. Typhimurium infection. Increased levels of intestinal IgA, translocation to liver and spleen, liver and intestinal lesions, pro-inflammatory cytokines in liver and ileum, and hepatic and intestinal myeloperoxidase and eosinophilic peroxidase activities were observed in animals infected with S. Typhimurium. All these parameters were reduced by the treatment with unfiltered 905 beer. In conclusion, the results show that a craft wheat beer brewed with S. cerevisiae UFMG A-905 maintained the probiotic properties of this yeast when administered orally to mice challenged with S. Typhimurium.

ALM Induces Cellular Quiescence in the Surgical Margin 3Days Following Liver Resection, Hemorrhage, and Shock.

The liver has a remarkable capacity to regenerate but not the resected lobe. Our aim was to examine the expression of a number of key genes of metabolism, proliferation, survival, and reprogramming 5mm inside the resected margin following resuscitation with adenosine, lidocaine, and Mg2+ (ALM) therapy. Anesthetized adult male Sprague-Dawley rats randomly assigned to ALM treatment (n=10) or Saline controls (n=10) underwent liver resection (60% left lateral lobe) and uncontrolled bleeding. After 15min, 3% NaCl±ALM bolus was administered, and after 60min, a 4h 0.9% NaCl±ALM stabilization 'drip' was commenced. After 72h monitoring (or high moribund score), histopathology, inflammatory mediators, and relative expression of key genes of tissue repair were measured in the remaining left lateral liver. ALM animals survived 72h compared to 23h for Saline controls (P=0.002). In the surgical margin, ALM therapy showed preservation of cellular architecture, whereas controls had increased inflammation and diffuse necrosis. Liver proinflammatory cytokines were also 2- to 4-fold higher in Saline controls. ALM therapy dramatically suppressed (∼70%) gene expression of four adenosine receptors, metabolic signaling, autophagy, apoptosis, and cell proliferation compared to controls, including suppression of the Yamanaka factors by up to 85%. We conclude ALM therapy preserved hepatocyte architecture with less inflammation and necrosis 3days after resection, hemorrhage, and shock. In addition, ALM induced cellular quiescence in the surgical margin, which may be a strategy for improved barrier protection and healing. Further studies are required to address this question.

Puerarin Prevents Acute Liver Injury via Inhibiting Inflammatory Responses and ZEB2 Expression.

Puerarin, an isoflavone component extracted from herb radix puerariae, is widely used in China in the treatment of immune diseases and inflammation. Previous studies have demonstrated that puerarin prevented acute lung injury by regulating inflammatory responses. However, the effect of puerarin on acute liver injury (ALI) was unclear. The purpose of this study was to explore the beneficial effects of puerarin when applied to ALI. We found that puerarin inhibited liver injury and inflammatory cell infiltration in lipopolysaccharide (LPS)/D-galactose (D-Gal)-induced acute liver failure and the liver pro-inflammatory cytokines interleukin (IL)-1β, IL-6, and tumor necrosis factor-alpha (TNF-α) in liver tissues with ALI and LPS-induced L-02 cells but upregulated the expression level of zinc finger E-box-binding homeobox 2 (ZEB2). Significantly, the results of this study showed that the inhibition of liver pro-inflammatory cytokine (IL-1β, IL-6, and TNF-α) production in LPS-induced L-02 cells was caused by ZEB2 overexpression. However, knocking down ZEB2 promoted LPS-mediated secretion of liver pro-inflammatory cytokines in L-02 cells. Additional experiments showed that puerarin inhibited the activation of the NF-κB signaling pathway by elevating ZEB2 expression in L-02 cells. In summary, puerarin most likely prevented activation of the pro-inflammatory factors and reduced LPS/D-Gal-induced liver injury by enhancing the ZEB2 expression level and, consequently, blocking activation of the NF-κB signaling pathway in the liver.

Toll-like receptor 4 mediates the development of fatigue in the murine Lewis Lung Carcinoma model independently of activation of macrophages and microglia

Cancer-related fatigue at the time of tumor diagnosis is commonly attributed to inflammation associated with the disease process. However, we have previously demonstrated that running wheel deficits occur well before increased expression of proinflammatory cytokines in the liver and brain in a murine model of human papilloma virus-related head and neck cancer (mEER). Further, we have demonstrated that genetic deletion of type I interleukin-1 receptor and MyD88 has no effect. In the current investigation we sought to test the generality of this finding by assessing whether there is a role for toll-like receptor (TLR) 4-dependent inflammation in the fatigue-like behavior observed in mice with Lewis Lung Carcinoma (LLC) or mEER tumors. Genetic deletion of TLR4 attenuated tumor-induced elevations in liver pro-inflammatory cytokine expression in both models. However, it only abrogated wheel running deficits in LLC tumor bearing mice. To determine whether TLR4 signaling in the LLC model involves innate immune cells, mice were treated with the colony stimulating factor (CSF)-1 receptor antagonist PLX-5622 before and throughout tumor development to deplete microglia and peripheral macrophages. Administration of PLX-5622 had no protective effect on wheel running deficits in either mEER or LLC tumor models despite effective depletion of microglia and a down regulation of peripheral proinflammatory cytokine expression. These results indicate that the TLR4 signaling that mediates fatigue-like behavior in LLC mice is not dependent upon microglial or peripheral macrophage activation. Based on the literature and our data demonstrating attenuation of ubiquitin proteasome pathway activation in the gastrocnemius muscle of Tlr4−/− mice implanted with LLC cells, we interpret our current findings as indication that skeletal muscle TLR4 signaling may be involved. These results are important in that they add to the evidence that tumor-induced fatigue develops independently from classical neuroinflammation.

RETRACTED ARTICLE: Heme oxygenase-1-modified bone marrow mesenchymal stem cells combined with normothermic machine perfusion to protect donation after circulatory death liver grafts

BackgroundDonation after circulatory death (DCD) liver grafts have a poor prognosis after transplantation. We investigated whether the outcome of DCD donor organs can be improved by heme oxygenase 1 (HO-1)-modified bone marrow-derived mesenchymal stem cells (BMMSCs) combined with normothermic machine perfusion (NMP), and explored its underlying mechanisms.MethodsBMMSCs were isolated, cultured, and transduced with the HO-1 gene. An NMP system was established. DCD rat livers were obtained, preserved by different methods, and the recipients were divided into 5 groups: sham operation, static cold storage (SCS), NMP, BMMSCs combined with NMP, and HO-1/BMMSCs combined with NMP (HBP) groups. Rats were sacrificed at 1, 7, and 14 days after surgery; their blood and liver tissue samples were collected; and liver enzyme and cytokine levels, liver histology, high-mobility group box 1 (HMGB1) levels in monocytes and liver tissues, and expression of Toll-like receptor 4 (TLR4) pathway-related molecules were evaluated.ResultsAfter liver transplantation, the SCS group showed significantly increased transaminase levels, liver tissue damage, and shorter survival time. The HBP group showed lower transaminase levels, intact liver morphology, prolonged survival time, and decreased serum and liver proinflammatory cytokine levels. In the NMP and SCS groups, HMGB1 expression in the serum, monocytes, and liver tissues and TLR4 pathway-related molecule expression were significantly decreased.ConclusionsHO-1/BMMSCs combined with NMP exerted protective effects on DCD donor liver and significantly improved recipient prognosis. The effect of HO-1/BMMSCs was greater than that of BMMSCs and was mediated via HMGB1 expression and TLR4 pathway inhibition.

Curcumin and Selenium Prevent Lipopolysaccharide/Diclofenac-Induced Liver Injury by Suppressing Inflammation and Oxidative Stress.

Diclofenac (DCL), an anti-inflammatory drug used to reduce pain and inflammation, ranks in the top causes of drug-induced liver injury. The inflammatory stress induced by inflammagens is implicated in DCL-induced liver injury. Curcumin (CUR) and selenium (Se) possess anti-inflammatory effects; therefore, this study evaluated their protective potential against lipopolysaccharide (LPS)/DCL-induced liver injury. Rats received CUR and/or Se for 7 days followed by a single intravenous administration of LPS 2 h before a single injection of DCL and two other doses of CUR and/or Se 2 and 8 h after DCL. Administration of nontoxic doses of LPS and DCL resulted in liver damage evidenced by the significantly elevated liver function markers in serum. LPS/DCL-induced liver injury was confirmed by histological alterations, increased lipid peroxidation and nitric oxide, and diminished glutathione and superoxide dismutase. CUR and/or Se prevented liver injury, histological alterations, and oxidative stress and boosted antioxidant defenses in LPS/DCL-induced rats. In addition, CUR and/or Se reduced serum C-reactive protein, liver pro-inflammatory cytokines, and the expression of TLR4, NF-κB, JNK, and p38, and upregulated heme oxygenase-1 (HO-1). In conclusion, CUR and/or Se mitigated LPS/DCL-induced liver injury in rats by suppressing TLR4 signaling, inflammation, and oxidative stress and boosting HO-1 and other antioxidants. Therefore, CUR and Se can hinder the progression and severity of liver injury during acute inflammatory episodes.

Assessment of the efficacy of a grape seed waste in counteracting the changes induced by aflatoxin B1 contaminated diet on performance, plasma, liver and intestinal tissues of pigs after weaning

The aim of this study was to investigate the potential of a grape seed byproduct to mitigate the harmful damage produced by aflatoxin B1 (AFB1) at systemic level in plasma and liver as well as at local level in the gastrointestinal tract in weaned piglets. Twenty four crossbred pigs (TOPIG) were randomly assigned to one of four experimental diets: 1)- control diet (normal compound feed for starter piglets without mycotoxin), 2)- AFB1 diet (compound feed contaminated with 320 ppb pure AFB1), 3)- GS diet (compound feed including 8% of grape seed meal), 4)- AFB1+GS diet (compound feed containing 8% of grape seed meal contaminated with 320 ppb AFB1) for 30 days. The results showed that pigs fed AFB1 diet had altered performance (−25.1%), increased the thiobarbituric substances (TBARS) concentration wile reduced total antioxidant capacity and activity of antioxidant enzymes (CAT, SOD and GPx) in plasma and organs. AFB1 produced a dual effect on inflammatory response by increasing the level of pro-inflammatory cytokines in liver and colon and decreasing these cytokines in duodenum. The inclusion of grape seed in the diet of AFB1 intoxicated pigs enhanced the antioxidant enzymes activity, decreased the pro-inflammatory cytokines and TBARS level and ameliorated the growth performance of AFB1-treated animals. These findings suggest that grape waste is a promising feed source in counteracting the harmful effect of aflatoxin B1.

Dietary choline supplementation attenuated high-fat diet-induced inflammation through regulation of lipid metabolism and suppression of NFκB activation in juvenile black seabream (Acanthopagrus schlegelii).

The present study aimed to investigate whether dietary choline can regulate lipid metabolism and suppress NFκB activation and, consequently, attenuate inflammation induced by a high-fat diet in black sea bream (Acanthopagrus schlegelii). An 8-week feeding trial was conducted on fish with an initial weight of 8·16 ± 0·01 g. Five diets were formulated: control, low-fat diet (11 %); HFD, high-fat diet (17 %); and HFD supplemented with graded levels of choline (3, 6 or 12 g/kg) termed HFD + C1, HFD + C2 and HFD + C3, respectively. Dietary choline decreased lipid content in whole body and tissues. Highest TAG and cholesterol concentrations in serum and liver were recorded in fish fed the HFD. Similarly, compared with fish fed the HFD, dietary choline reduced vacuolar fat drops and ameliorated HFD-induced pathological changes in liver. Expression of genes of lipolysis pathways were up-regulated, and genes of lipogenesis down-regulated, by dietary choline compared with fish fed the HFD. Expression of nfκb and pro-inflammatory cytokines in liver and intestine was suppressed by choline supplementation, whereas expression of anti-inflammatory cytokines was promoted in fish fed choline-supplemented diets. In fish that received lipopolysaccharide to stimulate inflammatory responses, the expression of nfκb and pro-inflammatory cytokines in liver, intestine and kidney were all down-regulated by dietary choline compared with the HFD. Overall, the present study indicated that dietary choline had a lipid-lowering effect, which could protect the liver by regulating intrahepatic lipid metabolism, reducing lipid droplet accumulation and suppressing NFκB activation, consequently attenuating HFD-induced inflammation in A. schlegelii.

Inhibition of the hepatic Nlrp3 protects dopaminergic neurons via attenuating systemic inflammation in a MPTP/p mouse model of Parkinson\u2019s disease

BackgroundParkinson’s disease (PD) is a neurodegenerative disorder with progressive loss of dopaminergic (DA) neurons. Systemic inflammation is shown to initiate and exacerbate DA neuronal degeneration in the substantia nigra. The infiltration and transformation of immune cells from the peripheral tissues are detected in and around the affected brain regions of PD patients. Our previous studies demonstrated the crucial role that microglial Nod-like receptor protein (NLRP) 3 inflammasome plays in the pathogenesis of PD. Nevertheless, the direct linkage between peripheral inflammation and DA neuron death remains obscure.MethodsIn the present study, we detected the NLRP3 expressions in the midbrain, liver, and bone marrow-derived macrophages in response to 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) acute and chronic challenge. We then used a tail vein injection of Nlrp3-siRNA wrapped with lentivirus to explore the potential influence of hepatic NLRP3 inflammasome-mediated inflammation on neuronal injury in a mouse model of PD via immunohistochemistry, ELISA, and Western blotting analysis.ResultsWe showed that siNlrp3 downregulated the NLRP3 protein expression and inhibited the activation of NLRP3 inflammasomes in mice livers. The tail vein injection of LV3-siNlrp3 reduced the liver pro-inflammatory cytokine production, which subsequently alleviated MPTP-triggered microglial activation and DA neuron loss in the midbrain. These findings indicated that inhibition of hepatic NLRP3 inflammasome weakens inflammatory cytokines spreading into the brain and delays the progress of neuroinflammation and DA neuronal degeneration.ConclusionThis study gives us an insight into the direct linkage between liver inflammation and DA neuron damage in the pathogenesis of PD and provides the potential target of NLRP3 for developing novel drugs for PD therapy.

Titanium dioxide nanoparticle stimulating pro-inflammatory responses in vitro and in vivo for inhibited cancer metastasis

The interaction of engineered nanoparticles (NPs) with the immune system and the possibility of inflammation induction are of particularly interest. Titanium dioxide nanoparticles (TiO2 NPs) are one of the most popular manufactured nanomaterials. In this study, we focused on the immune-modulatory effect of commercial P-25 TiO2 NPs in vivo and in vitro and their crucial role in cancer metastasis. The female C57BL/6 mice were injected into abdominal cavity with PBS or P-25 TiO2 to investigate the immune-modulatory function of P-25. And breast cancer cells were intravenously (i.v.) injected into mouse to establish the liver and lung cancer metastasis model. Peritoneal macrophage was used to investigate the macrophage polarization in vitro. Results showed us that peritoneal macrophage exposed to P-25 TiO2 NPs displayed activated M1 macrophage response, as evidenced by the increased mRNA expression of interleukin-1β (IL1β), IL6, TNFα, CCR7 and inducible nitric oxide synthase (iNOS). After exposure of TiO2 NPs in vivo for 21 days, the body weights of mice decreased significantly, which were accompanied by an infiltration of immune cells in liver and spleen in 20 mg/kg BW treated group. Importantly, the production of pro-inflammatory cytokines in liver, spleen and the serum were amplified, which indicated the tissue and systemic inflammation induced by TiO2 NPs. In addition, the activation of immune response induced by P-25 TiO2 NPs was correlated with their ability to inhibit cancer metastasis. Our results delineated the stimulating pro-inflammatory response induced by P-25 TiO2 NPs and their outcome in vivo for cancer metastasis.

Dihydromyricetin from Vine Tea ( <i>Ampelopsis grossedentata</i>) Prevents Diet-Induced Obesity by Modulating the Gut Microbiota Composition

Background: Gut microbiota plays a decisive role in the pathogenesis of obesity. Targeting the gut microbiota are potential therapies for obesity. Dihydromyricetin (DMY), a flavanonol compound isolated from vine tea (Ampelopsis grossedentata) in the traditional Chinese medicine, improves glucose and lipid metabolism despite of low bioavailability. Methods: Mice were fed with a normal chow diet (NCD) or high-fat diet (HFD), and HFD-fed mice was supplemented with DMY once daily by intragastric gavage for 13 weeks. Serum lipopolysaccharide (LPS) was measured by ELISA, and expressions of tight junction proteins in colon and pro-inflammatory cytokines in liver and epididymal adipose tissues were determined by quantitative PCR. The gut microbiota was analyzed by 16S rDNA sequencing. Using the method combined gut microbiota depletion and repopulation in HFD-fed mice, the causation that DMY reduces obesity by targeting the gut microbiota was explored. Results: DMY reduced body weight gain, fat accumulation and hepatic steatosis, and improved glucose homeostasis and insulin sensitivity in HFD-fed mice. The metabolic endotoxemia, chronic low-grade inflammation and leaky gut were alleviated. DMY reverses the gut microbiota of HFD-fed mice to the composition similar with that of NCD-fed mice. Moreover, the beneficial effects of DMY on HFD-induced obesity were eliminated by gut microbiota depletion, and were subsequently restored together with the modulation of gut microbiota composition after microbiota repopulation. Conclusions: Supplementation of DMY from vine tea represents an effective and implementable strategy that modulates the potentially beneficial gut commensal bacteria to prevent obesity, non-alcoholic fatty liver disease and type 2 diabetes. Funding Statement: This study was financially supported by the National Natural Science Foundation of China (No. 81503013) and Natural Science Foundation of Hubei Province (No. 2017CFB481). Declaration of Interests: The authors declare no conflict of interest. Ethics Approval Statement: The animal experiment was approved by the Institutional Animal Care and Use Committee at Tongji Medical College, Huazhong University of Science and Technology (IACUC No. S769).

Cytokine gene expression and pathology in experimental Pasteurella multocida infection in mice

The study was conducted to know the pathology and cytokine gene expression studies in experimental infection with Pasteurella multocida in mice. Swiss albino mice (20) were inoculated with P. multocida (200 μl of 1 × 108 cfu/ml) and control mice with sterile PBS intraperitoneally and sacrificed 4 mice at 6, 12, 18 and 24 h. Mice showed dullness, lethargy and unable to move at 18 and 24 h after inoculation. Histopathology revealed changes in liver, kidney, spleen, lung and no observable changes in heart and abdominal muscles. Liver showed septicemia condition and acute bronchopneumonia of lung at 24 h. TNF-α gene showed 20-fold increase in liver and spleen and 5-folds in kidney. There was upregulation of pro-inflammatory cytokines in liver, kidney, spleen and IL–10 gene at later periods of infection which is a new finding, needs further study. Thus, the present study indicated that increase in tissue cytokine gene expression concurred with histopathological changes were attributed to the pathogenesis of Pasteurellosis in mice.

Celastrol ameliorates liver metabolic damage caused by a high-fat diet through Sirt1

ObjectiveCelastrol was recently identified as a potential novel treatment for obesity. However, the effect of Celastrol on nonalcoholic fatty liver disease (NAFLD) remains elusive. The aim of this study is to evaluate the role of Celastrol in NAFLD. MethodsFunctional studies were performed using wild-type C57BL/6J (WT) mice and liver specific Sirt1-deficient (LKO) mice. The molecular mechanism was explored in primary mouse liver and primary hepatocytes. ResultsWhen WT mice receiving a high-fat diet (HFD) were treated with Celastrol, reductions in body weight, subcutaneous and visceral fat content, and liver lipid droplet formation were observed, along with reduced hepatic intracellular triglyceride and serum triglyceride, free fatty acid, and ALT concentrations. Furthermore, Celastrol decreased hepatic sterol regulatory element binding protein 1c (Srebp-1c) expression, enhanced the phosphorylation of hepatic AMP-activated protein kinase α (AMPKα), and increased the expression of hepatic serine–threonine liver kinase B1 (LKB1). Additionally, Celastrol treatment improved glucose tolerance and insulin sensitivity in WT mice fed the HFD. Celastrol administration also improved the anti-inflammatory and anti-oxidative status by inhibiting nuclear factor kappa B (NFκB) activity and the mRNA levels of proinflammatory cytokines and increasing mitochondrial DNA copy number and anti-oxidative stress genes expression in WT mice liver, in vivo and in vitro. Moreover, Celastrol induced hepatic Sirt1 expression in WT mice, in vivo and in vitro. These Celastrol-mediated protective effects in WT mice fed a HFD were abolished in LKO mice fed a HFD. It was more interesting that Celastrol aggravated HFD-induced liver damage in LKO mice fed a HFD by inhibiting the phosphorylation of AMPKα and boosting the translocation of NFκB into the nucleus, thereby resulting in the increase of Srebp-1c expression and the mRNA levels of liver proinflammatory cytokines. ConclusionsCelastrol ameliorates NAFLD by decreasing lipid synthesis and improving the anti-oxidative and anti-inflammatory status. And Sirt1 has an important role in Celastrol-ameliorating liver metabolic damage caused by HFD.