Human islet amyloid polypeptide-induced ß-cell cytotoxicity is linked to formation of α-sheet structure.

Type 2 diabetes (T2D) results from insulin secretory dysfunction arising in part from the loss of pancreatic islet ß-cells. Several factors contribute to ß-cell loss, including islet amyloid formation, which is observed in over 90% of individuals with T2D. The amyloid is comprised of human islet amyloid polypeptide (hIAPP). Here we provide evidence that early in aggregation, hIAPP forms toxic oligomers prior to formation of amyloid fibrils. The toxic oligomers contain α-sheet secondary structure, a nonstandard secondary structure associated with toxic oligomers in other amyloid diseases. De novo, synthetic α-sheet compounds designed to be nontoxic and complementary to the α-sheet structure in the toxic oligomers inhibit hIAPP aggregation and neutralize oligomer-mediated cytotoxicity in cell-based assays. In vivo administration of an α-sheet design to mice for 4 weeks revealed no evidence of toxicity nor did it elicit an immune response. Furthermore, the α-sheet designs reduced endogenous islet amyloid formation and mitigation of amyloid-associated ß-cell loss in cultured islets isolated from an hIAPP transgenic mouse model of islet amyloidosis. Characterization of the involvement of α-sheet in early aggregation of hIAPP and oligomer toxicity contributes to elucidation of the molecular mechanisms underlying amyloid-associated ß-cell loss.

Association between gut microbiota and NAFLD/NASH: a bidirectional two-sample Mendelian randomization study.

Background: Recent studies have suggested a relationship between gut microbiota and non-alcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH). However, the nature and direction of this potential causal relationship are still unclear. This study used two-sample Mendelian randomization (MR) to clarify the potential causal links. Methods: Summary-level Genome-Wide Association Studies (GWAS) statistical data for gut microbiota and NAFLD/NASH were obtained from MiBioGen and FinnGen respectively. The MR analyses were performed mainly using the inverse-variance weighted (IVW) method, with sensitivity analyses conducted to verify the robustness. Additionally, reverse MR analyses were performed to examine any potential reverse causal associations. Results: Our analysis, primarily based on the IVW method, strongly supports the existence of causal relationships between four microbial taxa and NAFLD, and four taxa with NASH. Specifically, associations were observed between Enterobacteriales (P =0.04), Enterobacteriaceae (P =0.04), Lachnospiraceae UCG-004 (P =0.02), and Prevotella9 (P =0.04) and increased risk of NAFLD. Dorea (P =0.03) and Veillonella (P =0.04) could increase the risks of NASH while Oscillospira (P =0.04) and Ruminococcaceae UCG-013 (P=0.005) could decrease them. We also identified that NAFLD was found to potentially cause an increased abundance in Holdemania (P =0.007) and Ruminococcus2 (P =0.002). However, we found no evidence of reverse causation in the microbial taxa associations with NASH. Conclusion: This study identified several specific gut microbiota that are causally related to NAFLD and NASH. Observations herein may provide promising theoretical groundwork for potential prevention and treatment strategies for NAFLD and its progression to NASH in future.

Clostridium perfringens Liver Abscess Disguised as Biliary Disease: A Report of Two Cases and a Review of the Literature.

Liver abscesses caused by Clostridium perfringens are rare but rapidly fatal. In only a few days, patients progress from liver abscess to sepsis, intravascular hemolysis, multiple organ failure, and even death. These abscesses often occur in patients after trauma or surgery or in those with immunodeficiency. Because patients only show non-specific symptoms such as fever and abdominal pain in the early stage, they can easily be misdiagnosed and miss the therapeutic window, resulting in a poor prognosis. The diagnosis of Clostridium perfringens liver abscess mainly depends on computed tomography (CT), needle aspiration, and/or blood culture. After diagnosis, treatments such as antibiotic therapy, surgical abscess drainage, blood transfusion as needed, and correction of metabolic disturbances must be immediately administered to prevent severe complications. Here, we present two cases of liver abscess due to Clostridium perfringens infection. Both patients initially presented only with fever, abdominal pain, and jaundice, symptoms that were easily confused with cholangitis caused by cholelithiasis. The patients then progressed rapidly and, despite receiving antimicrobial and multimodal sepsis treatment, both eventually died of multiple organ dysfunction syndrome. Clinicians should be on high alert for Clostridium perfringens liver abscesses disguised as biliary disease. Early diagnosis and treatment with the appropriate antibiotics and surgery are fundamental for the survival of the affected patients.

Role of Kupffer cells in tolerance induction after liver transplantation.

Currently, liver transplantation has reached a level of maturity where it is considered an effective treatment for end-stage liver disease and can significantly prolong the survival time of patients. However, acute and chronic rejection remain major obstacles to its efficacy. Although long-term use of immunosuppressants can prevent rejection, it is associated with serious side effects and significant economic burden for patients. Therefore, the investigation of induced immune tolerance holds crucial theoretical significance and socio-economic value. In fact, the establishment of immune tolerance in liver transplantation is intricately linked to the unique innate immune system of the liver. Kupffer cells, as a crucial component of this system, play a pivotal role in maintaining the delicate balance between inflammatory response and immune tolerance following liver transplantation. The important roles of different functions of Kupffer cells, such as phagocytosis, cell polarization, antigen presentation and cell membrane proteins, in the establishment of immune tolerance after transplantation is comprehensively summarized in this paper. Providing theoretical basis for further study and clinical application of Kupffer cells in liver transplantation.

Designed α-sheet peptides disrupt uropathogenic E. coli biofilms rendering bacteria susceptible to antibiotics and immune cells.

Uropathogenic Escherichia coli account for the largest proportion of nosocomial infections in the United States. Nosocomial infections are a major source of increased costs and treatment complications. Many infections are biofilm associated, rendering antibiotic treatments ineffective or cause additional complications (e.g., microbiome depletion). This work presents a potentially complementary non-antibiotic strategy to fight nosocomial infections by inhibiting the formation of amyloid fibrils, a proteinaceous structural reinforcement known as curli in E. coli biofilms. Despite extensive characterization of the fibrils themselves and their associated secretion system, mechanistic details of curli assembly in vivo remain unclear. We hypothesized that, like other amyloid fibrils, curli polymerization involves a unique secondary structure termed "α-sheet". Biophysical studies herein confirmed the presence of α-sheet structure in prefibrillar species of CsgA, the major component of curli, as it aggregated. Binding of synthetic α-sheet peptides to the soluble α-sheet prefibrillar species inhibited CsgA aggregation in vitro and suppressed amyloid fibril formation in biofilms. Application of synthetic α-sheet peptides also enhanced antibiotic susceptibility and dispersed biofilm-resident bacteria for improved uptake by phagocytic cells. The ability of synthetic α-sheet peptides to reduce biofilm formation, improve antibiotic susceptibility, and enhance clearance by macrophages has broad implications for combating biofilm-associated infections.

Comprehensive multimodal management of borderline resectable pancreatic cancer: Current status and progress.

Borderline resectable pancreatic cancer (BRPC) is a complex clinical entity with specific biological features. Criteria for resectability need to be assessed in combination with tumor anatomy and oncology. Neoadjuvant therapy (NAT) for BRPC patients is associated with additional survival benefits. Research is currently focused on exploring the optimal NAT regimen and more reliable ways of assessing response to NAT. More attention to management standards during NAT, including biliary drainage and nutritional support, is needed. Surgery remains the cornerstone of BRPC treatment and multidisciplinary teams can help to evaluate whether patients are suitable for surgery and provide individualized management during the perioperative period, including NAT responsiveness and the selection of surgical timing.

Research trends and hotspots of neoadjuvant therapy in pancreatic cancer: a bibliometric analysis based on the Web of Science Core Collection.

Neoadjuvant therapy (NAT) for pancreatic cancer (PC) has achieved certain results. This article was aimed to analyze the trends in NAT in PC over the past 20 years using bibliometric analysis and visualization tools to guide researchers in exploring future research hotspots. Articles related to NAT for PC were retrieved from the Web of Science Core Collection for the period 2002-2021. The information was analyzed and visualized using VOSviewer, Citespace, Microsoft Excel and R software. The number of articles per year has continued to increase over the past 20 years. Of the 1,598 eligible articles, the highest number was from the United States (760), and an analysis of institutions indicated that the University of Texas System (150) had the highest number of articles. Matthew H. G. Katz had the highest number of citations and the highest H-index. "Pancreatic cancer" (981), "Resection" (623), "Cancer" (553), "Neoadjuvant therapy" (509) and "Survival" (484) were the top five ranked keywords. Combined with the keywords-cluster analysis and citation burst analysis, current research hotspots were the optimal NAT regimen, NAT response assessment, NAT for resectable PC and management of complications. NAT has received increasing attention in the field of PC over the past 20 years, but greater collaboration between countries and additional multicenter randomized clinical trials are needed. Overall, we have revealed current research hotspots and provided valuable information for the choice of future research directions.

Impact of Surgery on Non-Functional Pancreatic Neuroendocrine Tumors ≤2†cm: Analyses With Propensity Score-Based Inverse Probability of Treatment Weighting.

Purpose: The impact of surgery on non-functional pancreatic neuroendocrine tumors (NF-PNETs) ≤2 cm is controversial. This study sought to demonstrate the impact of surgery on the prognosis of NF-PNETs ≤2 cm with different biological behaviors. Methods: Patients with NF-PNETs ≤2 cm from 2004 to 2015 in the Surveillance, Epidemiology, and End Results database were included in this study. An inverse probability of treatment weighting (IPTW) method was used to reduce the selection bias. Kaplan-Meier survival analysis and Cox proportional hazards regression were used to evaluate the effect of surgery on the prognosis. Results: In the IPTW-adjusted Cox proportional hazards regression analysis, surgery improved the cancer-specific survival (CSS) in the overall cohort (hazard ratio [HR], 0.187; 95% confidence interval [CI], 0.102-0.343; p < 0.001), patients with poorly differentiated or undifferentiated tumor grades (HR, 0.238; 95% CI, 0.105-0.64; p < 0.001), patients with distant metastasis (HR, 0.102; 95% CI, 0.021-0.496; p = 0.005), and patients with local invasion (HR, 0.059; 95% CI, 0.005-0.683; p = 0.002). Surgery did not improve the CSS in patients with lymph node metastasis only (HR, 0.26; 95% CI, 0.0462-1.461; p = 0.126) or patients with well or moderate differentiation while without distant and lymph node metastasis (HR, 0.387; 95% CI, 0.146-1.028; p = 0.057). Conclusions: Among patients with NF-PNETs ≤2 cm, different biological behaviors correlate with different prognostic impacts of surgery. As long as distant metastasis does not occur and the grade is well-moderately differentiated, these patients will not benefit from surgery no matter whether lymph node metastasis occurs or not. However, when local invasion appears in this group of patients, surgery should be performed. Moreover, patients with a tumor grade of poorly differentiated or undifferentiated or those with distant metastases may benefit from surgery.

Kupffer cells depletion alters cytokine expression and delays liver regeneration after Radio-frequency-assisted Liver Partition with Portal Vein Ligation.

Radio-frequency-assisted Liver Partition with Portal Vein Ligation (RALPP) induces comparable hypertrophy of the liver remnant compared to Associating Liver Partition and Portal vein ligation for Staged hepatectomy (ALPPS) in humans. However, whether it is significantly improved compared to ALPPS is unclear, and the underlying mechanisms of liver regeneration after RALPP need to further investigate. The present study was to develop an animal model mimicking RALPP and explore mechanisms of liver regeneration. The mice in RALPP group received liver radiofrequency ablation and 90% portal vein ligation (PVL), followed by resection of the targeted liver within two days after the first surgery. The mice in ALPPS group underwent 90% PVL combined with parenchyma transection. Controls received liver radiofrequency ablation (RAF group) or PVL (PVL group) or small left lateral lobe (LLL group) resection alone. Liver regeneration was assessed by liver weight and proliferation-associated molecules. The role of Kupffer cells (KCs) in liver regeneration was investigated after RALPP. The results showed that RALPP induced comparable liver regeneration compared to ALPPS, but with less liver injury and mortality in mice. RALPP led to over-expression of TNF-α and IL-6 in the circulating plasma compared with PVL. KCs infiltrating in liver tissues was a characteristic of mice in the RALPP group. KCs depletion markedly depressed cytokine expression and delayed liver regeneration after RALPP. These results suggested that RALPP in mice induced accelerated liver regeneration similar to ALPPS, but safer than ALPPS. KCs depletion altered cytokine expression and delayed liver regeneration after RALPP.

SCARF1 promotes M2 polarization of Kupffer cells via calcium-dependent PI3K-AKT-STAT3 signalling to improve liver transplantation.

OBJECTIVES: This study aimed to investigate the protective effect of SCARF1 on acute rejection (AR), phagocytic clearance of Kupffer cells (KCs), M2 polarization and the exact mechanism underlying these processes. METHODS: AAV was transfected into the portal vein of rats, and AR and immune tolerance (IT) models of liver transplantation were established. Liver tissue and blood samples were collected. The level of SCARF1 was detected via WB and immunohistochemical staining. Pathological changes in liver tissue were detected using HE staining. Apoptotic cells were detected using TUNEL staining. KC polarization was assessed via immunohistochemical staining. Primary KCs were isolated and co-cultured with apoptotic T lymphocytes. Phagocytosis of apoptotic cells and polarization of KCs were both detected using immunofluorescence. Calcium concentration was determined using immunofluorescence and a fluorescence microplate reader. The levels of PI3K, p-AKT and P-STAT3 were assessed via WB and immunofluorescence. RESULTS: Compared to the IT group, the level of SCARF1 was significantly decreased in the AR group. Overexpression of SCARF1 in KCs improved AR and liver function markers. Enhanced phagocytosis mediated by SCARF1 is beneficial for improving the apoptotic clearance of AR and promoting M2 polarization of KCs. SCARF1-mediated enhancement of phagocytosis promotes increased calcium concentration in KCs, thus further activating the PI3K-AKT-STAT3 signalling pathway. CONCLUSIONS: SCARF1 promotes the M2 polarization of KCs by promoting phagocytosis through the calcium-dependent PI3K-AKT-STAT3 signalling pathway.

Left-sided portal hypertension caused by peripancreatic lymph node tuberculosis misdiagnosed as pancreatic cancer: a case report and literature review.

BACKGROUND: Left-sided portal hypertension (LSPH) is an extremely rare clinical syndrome, and it is the only form of curable portal hypertension. It is primarily caused by pancreatic disease, and is associated with complications that cause spleen vein compression. Specific symptoms are often lacking, rendering it difficult to diagnose. Splenectomy is the main treatment for cases complicated by variceal bleeding, and the effects of treatment primarily depend on the condition of the primary disease. CASE PRESENTATION: The patient was a 29-year-old woman who was admitted to the hospital for repeated hematemesis and black stool. She had been misdiagnosed with pancreatic cancer 7 years prior. Combined imaging and endoscopic examination indicated varicose gastric fundus veins, a pancreatic mass, and enlarged peripancreatic lymph nodes. Laboratory investigations revealed reduced erythrocyte, platelet, and leukocyte counts, the interferon gamma release assay was positive, and liver function was normal. Abdominal exploration, splenectomy, varicose vein dissection, and lesion resection were performed via laparotomy. Postoperative biopsy analysis confirmed the diagnosis of lymph node tuberculosis. Based on the above-described factors, LSPH caused by peripancreatic lymph node tuberculosis was a diagnosed. CONCLUSIONS: Herein we describe the first reported case of LSPH caused by peripancreatic lymph node tuberculosis. When left portal hypertension occurs simultaneously, peripancreatic lymph node tuberculosis is often misdiagnosed as pancreatic cancer. Further studies are necessary to develop a more favorable diagnostic method for pancreas masses and more advantageous therapy for LSPH, especially in cases caused by mechanical compression.

IL-4 Alleviates Ischaemia-Reperfusion Injury by Inducing Kupffer Cells M2 Polarization via STAT6-JMJD3 Pathway after Rat Liver Transplantation.

BACKGROUND: Liver ischaemia-reperfusion injury (IRI) remains a problem in liver transplantation. Interleukin-4 (IL-4) has been found to reduce liver IRI, but the exact mechanism remains unclear. METHODS: Donor livers were infused with recombinant IL-4 or normal saline during cold storage, and the hepatocellular apoptosis and the inflammatory response were detected. The effect of IL-4 treatment on Kupffer cells (KCs) polarization and expression of the STAT6-JMJD3 pathway was evaluated in vivo and in vitro. KCs in donor livers were depleted by clodronate liposome treatment or JMJD3 was inhibited by GSK-J4 before liver transplantation to determine whether the protective effect of IL-4 treatment was dependent on KCs. RESULTS: IL-4 treatment decreased sALT and sAST levels and alleviated hepatocellular apoptosis and inflammation at 6 h after liver transplantation. IL-4 treatment induced KCs alternatively activated (M2) polarization in vitro. KCs in donor livers were depleted by clodronate liposome treatment or JMJD3 was inhibited by GSK-J4 before liver transplantation to determine whether the protective effect of IL-4 treatment was dependent on KCs. in vivo and in vitro. KCs in donor livers were depleted by clodronate liposome treatment or JMJD3 was inhibited by GSK-J4 before liver transplantation to determine whether the protective effect of IL-4 treatment was dependent on KCs. CONCLUSIONS: IL-4 treatment-induced KCs M2 polarization was dependent on the STAT6-JMJD3 pathway and protected liver grafts from IRI after liver transplantation.

Acetyl-3-Aminoethyl Salicylate Ameliorates Hepatic Ischemia/Reperfusion Injury and Liver Graft Survival Through a High-Mobility Group Box 1/Toll-Like Receptor 4-Dependent Mechanism.

In liver transplant cases, severe hepatic ischemia/reperfusion injury (HIRI) is a strong predictor of adverse liver graft and overall outcomes. During HIRI, high-mobility group box 1 (HMGB1) promotes hepatocellular death and proinflammatory cytokine secretion by toll-like receptor 4 (TLR4). Because salicylates inhibit HMGB1/TLR4 interaction, we hypothesized that salicylates may ameliorate HIRI-induced liver damage by inhibiting HMGB1/TLR4 axis activation. Using a murine model of HIRI, we found that the salicylate acetyl-3-aminoethyl salicylic acid (ac3AESA) reduced serum alanine aminotransferase and aspartate aminotransferase as well as Suzuki scores and apoptotic cell counts after HIRI. Ac3AESA also down-regulated hepatocellular HMGB1 and TLR4 expression, phosphorylated inhibitor of κBα, extracellular signal-regulated kinase 1/2, c-Jun N-terminal kinase, p38 mitogen-activated protein kinase, cleaved caspase 3, and cleaved caspase 1 levels after HIRI. Ac3AESA reduced liver Kupffer cell transcription of proinflammatory mediators tumor necrosis factor α (TNF-α), interleukin (IL) 6, IL1ß, chemokine (C-X-C motif) ligand (CXCL) 1, CXCL2, and CXCL8 after HIRI. Ac3AESA also dose-dependently reduced in vitro release of Kupffer cell TNF-α. Employing a murine orthotopic liver transplantation model, we found daily ac3AESA administration up to day 10 after transplant improved liver graft survival, suppressed allograft damage, and down-regulated HMGB1/TLR4 signaling. These benefits to survival and allograft health were maintained for cold ischemia times of 12 and 18 hours. Notably, TLR4 knockout eliminated all foregoing ac3AESA-induced effects. In conclusion, ac3AESA partially rescues the negative effects of HIRI and prolongs liver graft survival in a TLR4-dependent manner.

α-ketoglutarate attenuates ischemia-reperfusion injury of liver graft in rats.

OBJECTIVE: The α-ketoglutarate (αKG), a metabolite of glutaminolysis, is reported to orchestrate macrophages activation. This study aims to clarify whether the αKG / glutaminolysis metabolism can suppress Kupffer cells (KCs) activation during liver transplantation and attenuate hepatic ischemia-reperfusion injury (IRI). METHODS: Donor livers were perfused with DM-αKG (a cell-permeable analog of αKG) or BPTES (an inhibitor of glutaminase 1) via portal vein during cold preservation, and controls were perfused with UW solution. Then, a rat model of liver transplantation was performed. Serum levels of alanine transaminase (ALT), total bilirubin (TBIL) and inflammatory cytokines, as well as histology, were analyzed after 24 h. KCs were isolated from grafts. RT-PCR and immunofluorescence were used to evaluate polarization-specific marker genes. Western bolt was employed to assess the expression of phosphorylation of glycogen synthase kinase 3ß (p-GSK3ß) and suppressor of cytokine signaling 1 (SOCS1). EMSA was utilized to quantify the NF-κB transcriptional activity. RESULTS: Compared with controls, DM-αKG perfusion decreased ALT and TBIL levels, alleviated liver damage, and reduced apoptosis, while BPTES group showed higher ALT and TBIL levels, severe damage and more apoptosis. Furthermore, DM-αKG perfusion suppressed NF-κB activity, up-regulated the expression of p-GSK3ß and SOCS1 in KCs, and shifted the M1/M2 balance toward an anti-inflammatory profile. Besides, DM-αKG suppressed serum pro-inflammatory cytokines secretion and increased IL-10. CONCLUSIONS: αKG produced by glutaminolysis protects liver graft from IRI by regulating the inflammatory response and modifying the polarization of KCs.

VEGF-C attenuates ischemia reperfusion injury of liver graft in rats.

BACKGROUND: Vascular endothelial growth factor receptor-3 (VEGFR-3) / vascular endothelial growth factor -c (VEGF-C) signaling is reported to negatively regulate TLR4-triggered inflammation of macrophages. This study aims to clarify whether the VEGFR-3/VEGF-C signaling can suppress Kupffer cells (KCs) activation and attenuate hepatic ischemia-reperfusion injury (IRI) after liver transplantation. METHODS: A rat model of liver transplantation was performed. Donor livers were perfused with VEGF-C injection via portal vein during cold preservation, and controls were perfused with UW solution. Serum levels of alanine transaminase (ALT), total bilirubin (TBIL) and inflammatory cytokines, as well as histology were analyzed after 24 h. KCs were isolated from grafts, RT-PCR and immunofluorescence were used to evaluate polarization-specific marker genes, western bolt was employed to assess the expression of suppressor of cytokine signaling 1(SOCS1) and phosphorylated glycogen synthase kinase 3ß (p-GSK3ß), and EMSA was utilized to quantify the NF-κB transcriptional activity. RESULTS: Compared with controls, VEGF-C perfusion reduced ALT and TBIL levels and alleviated liver damage. Furthermore, VEGF-C perfusion suppressed serum proinflammatory cytokines secretion and increased IL-10.In addition, the VEGFR-3 mRNA of KCs was increased after reperfusion. VEGF-C perfusion suppressed NF-κB activity and up-regulated the expression of SOCS1 and p-GSK3ß in KCs, and shifted the M1/M2 balance toward an anti-inflammatory profile. CONCLUSION: Exogenous VEGF-C protects liver graft from IRI by regulating the inflammatory response and modifying polarization of KCs.

Liver X Receptors Activation Attenuates Ischemia Reperfusion Injury of Liver Graft in Rats.

Purpose: Suppression of the Toll like receptor 4 (TLR4)-nuclear factor-κB (NF-κB) signaling was critical in protection against liver IRI. Previous studies revealed that Liver X receptors (LXRs) activation could antagonize TLR4-NF-κB signaling. The purpose of this study is to determine whether LXRs agonist GW3965 can suppress the TLR4-NF-κB signaling during liver transplantation and protect ischemia-reperfusion injury (IRI). Materials and Methods: Sprague Dawley (SD) rats were used to perform orthotropic liver transplantation. Donors were pretreatment with GW3965 (0.3 mg/kg) through caudal vein injection 30 min before the surgery. The followings were analyzed after transplantation: alanine aminotransferase (ALT), interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) level in serum, ATP binding cassette transporter A1 (Abca1) expression, NF-κB transcriptional activity, apoptosis and histological injury. Results: GW3965 pretreatment significantly ameliorated the degree of IRI associated with the effects of upregulating Abca1 expression, inhibiting NF-κB transcriptional activity, and downregulating TNF-α and IL-6 level. Conclusion: LXRs activation attenuated hepatic IRI by preventing TLR4-NF-κB signaling.

Tauroursodeoxycholic acid alleviates hepatic ischemia reperfusion injury by suppressing the function of Kupffer cells in mice.

The aim of this study is to investigate the protective effect and the mechanism of tauroursodeoxycholic acid (TUDCA) against hepatic ischemia reperfusion (IR) injury. Male Balb/c mice were intraperitoneally injected with tauroursodeoxycholic acid (400 mg/kg) or saline solution, once per day for 3 days before surgery, and then the model of hepatic I/R injury was established. Blood and liver samples were collected from each group at 3, 6, and 24 h after surgery. Liver pathological changes, liver function, hepatocyte apoptosis and proinflammatory factors were detected. KCs were extracted, cultured and treated with TUDCA or phosphate-buffered saline (PBS) for 24 h, and then viability and phagocytosis were examined. Additionally, IRE1α/TRAF2/NF-κB pathway activity and AML cell apoptosis were detected. The results showed that TUDCA alleviated hepatic I/R injury, the level of liver function markers, and hepatocyte apoptosis in vivo. Furthermore, the proinflammatory effects of KCs were suppressed by down-regulating IRE1α/TRAF2/NF-κB pathway activity in vivo. TUDCA dose-dependently suppressed the expression of inflammatory factors and IRE1α/TRAF2/NF-κB pathway activity in vitro, consistent with the in vivo results. Therefore, TUDCA can effectively alleviate hepatic IR injury by down-regulating the activity of the IRE1α/TRAF2/NF-κB pathway to suppress the function of KCs.

TIM­4 blockade of KCs combined with exogenous TGF­ß injection helps to reverse acute rejection and prolong the survival rate of mice receiving liver allografts.

An acute reaction response (AR) following liver transplantation (LT) is caused by immune responses that are primarily mediated by T lymphocytes. Kupffer cells (KCs) are the largest antigen presenting cell (APC) group in vivo and are the primary modulators of the inflammatory or tolerogenic immune response in liver tissues. T cell immunoglobulin­domain and mucin­domain-4 (TIM­4), the only TIM protein not expressed on T cells, is expressed on APCs; suggesting that it mediates the various immune responses. However, to the best of our knowledge, the role of TIM­4 expressed by KCs in LT injury remains unknown. The present study aimed to explore whether and how TIM­4 expressed by KCs is involved in the AR of liver allografts. Orthotopic liver transplantation (OLT) was performed in mice to establish a model of AR and results demonstrated that LT may lead to the augmented expression of TIM­4 in activated KCs. It was also revealed that TIM­4 blockade markedly attenuated AR injury in vivo via the nuclear factor­κB (NF­κB) and p38 mitogen­activated protein kinase (p38 MAPK) signaling pathways. In addition, levels of transforming growth factor­ß (TGF­ß) were increased following TIM­4 blockade. Furthermore, in a KC/cluster of differentiation (CD)4+ T cell co­culture system, blocking TIM­4 inhibited T helper 2 (Th2) differentiation, stimulated the conversion of naive (CD)4+ T cells into CD4+CD25+Forkhead box protein p3+ T regulatory cells and suppressed interleukin­4/signal transducer and activator of transcription 6/transcription factor gata3 signaling. These effects were enhanced following the addition of TGF­ß. It was also demonstrated that LT mouse models treated with TIM­4 blockade in combination with exogenous TGF­ß injections, increased the survival times of mice and enhanced the amelioration of AR in LT. These results indicate that blocking the expression of TIM­4 by KCs via exogenous TGF­ß injection may be an effective therapeutic strategy to inhibit the AR of liver allografts.

Differential metabonomic profiles of primary hepatocellular carcinoma tumors from alcoholic liver disease, HBV-infected, and HCV-infected cirrhotic patients.

Our objective was to comparatively profile the metabolite composition of primary hepatocellular carcinoma (HCC) tumors from alcoholic liver disease (ALD), hepatitis B virus (HBV)-infected, and hepatitis C virus (HCV)-infected cirrhotic patients. Primary HCC tumors were collected from ALD, HBV-infected, and HCV-infected cirrhotic patients (n=20 each). High-resolution magic-angle spinning proton nuclear magnetic resonance spectroscopy and metabonomic data analysis were performed to compare HCC tumors from the three groups. Sensitivity analyses were performed to determine the effects of diabetes, high body mass index, and smoking status. Metabonomic pathway analyses were conducted to identify dysregulated pathways. Three metabolites were significantly differentiated between ALD and HBV-infected patients, which were distinguishable by changes in ketone body, glycerolipid, and phenylalanine metabolism. Five metabolites were significantly differentiated between ALD and HCV-infected patients, which were distinguishable by changes in ketone body, alanine/aspartate/glutamate, and phenylalanine metabolism. Six metabolites were significantly differentiated between HBV-infected and HCV-infected patients, which were distinguishable by changes in ketone body, tyrosine, and alanine/aspartate/glutamate metabolism. In conclusion, this is the first study to demonstrate that the metabolic phenotypes of primary HCC tumors vary significantly across ALD, HBV-infected, and HCV-infected cirrhotic patients.

NLRP3 Deletion Inhibits the Non-alcoholic Steatohepatitis Development and Inflammation in Kupffer Cells Induced by Palmitic Acid.

The cleavage and secretion of pro-inflammatory cytokines IL-1ß and IL-18 is regulated by NLRP3 (NACHT, LRR, and PYD domain-containing protein 3) inflammasome activation. Kupffer cells (KCs) are implicated in the pathogenesis of various liver diseases, such as non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease, and liver fibrosis. However, the role of NLRP3 played in the non-alcoholic steatohepatitis (NASH) has yet to be evaluated. In the present study, methionine-choline-deficient (MCD) diet was used to establish the mice NASH model. The expression levels of F4/80 and NLRP3 in liver tissues were evaluated, and the IL-1ß and IL-18 in serum were also evaluated. KCs were isolated from wild-type (WT) mice and NLRP3 knockout (NLRP3-/-) mice and then randomly divided into two groups: the control and palmitic acid (PA) groups. The expression levels of NLRP3, ASC, and caspase-1 in KCs were determined by RT-PCR, western blotting, and immunofluorescence. The levels of IL-1ß and IL-18 in the supernatant (SN) of KCs were evaluated by enzyme-linked immunosorbent assay (ELISA). We found that KCs and NLRP3 play pro-inflammatory roles in the progression of NASH, probably through secretions of IL-1ß and IL-18 by KCs induced by PA. PA could act as a kind of damage-associated molecular patterns to elevate the messenger RNA and protein expression levels of NLRP3, ASC, and caspase-1 in KCs from WT mice. In the contrast, NLRP3 deletion could inhibit the NLRP3 inflammasome upregulation and activation in KCs induced by PA. Furthermore, the levels of pro-inflammatory cytokines IL-1ß and IL-18 in the SN of KCs from WT mice were all elevated with the stimulation of PA, and the increase of these cytokines in the SN was blocked by NLRP3 deletion. In conclusion, our novel findings demonstrate that NLRP3 plays a pivotal role in NASH development and pro-inflammatory cytokines IL-1ß and IL-18 secretion induced by PA stimulation, and NLRP3 might be an effective potential target for the treatment of liver inflammatory diseases associated with NLRP3 inflammasome activation.