Reduced pannexin 1-IL-33 axis function in donor livers increases risk of MRSA infection in liver transplant recipients

Liver transplantation patients are at increased risk for methicillin-resistant Staphylococcus aureus (MRSA) infection, but the molecular mechanism remains unclear. We found that genetic predisposition to low pannexin 1 (PANX1) expression in donor livers was associated with MRSA infection in human liver transplantation recipients. Using Panx1 and Il-33-knockout mice for liver transplantation models with MRSA tail vein injection, we demonstrated that Panx1 deficiency increased MRSA-induced liver injury and animal death. We found that decreased PANX1 expression in the liver led to reduced release of adenosine triphosphate (ATP) from hepatocytes, which further reduced the activation of P2X2, an ATP-activating P2X receptor. Reduced P2X2 function further decreased the NLRP3-mediated release of interleukin-33 (IL-33), reducing hepatic recruitment of macrophages and neutrophils. Administration of mouse IL-33 to Panx1^-/- mice significantly (P = 0.011) ameliorated MRSA infection and animal death. Reduced human hepatic IL-33 protein abundance also associated with increased predisposition to MRSA infection. Our findings reveal that genetic predisposition to reduced PANX1 function increases risk for MRSA infection after liver transplantation by decreasing hepatic host innate immune defense, which can be attenuated by IL-33 treatment.

Ferulic acid prevents aflatoxin B1-induced liver injury in rats via inhibiting cytochrome P450 enzyme, activating Nrf2/GST pathway and regulating mitochondrial pathway

Aflatoxin B1 (AFB1) causes oxidative stress and hepatocyte apoptosis through its epoxidized metabolite AFBO, which is catalyzed by CYP450 enzymes. Ferulic acid (FA) is a phenolic acid commonly found in plants and is known for its antioxidant capacity. However, the role of FA in AFB1-induced liver injury is still elusive. In this study, rats were exposed to AFB1 and simultaneously treated with FA for 30 days. The results showed that I) FA alleviated the histopathological changes induced by AFB1, inhibited the elevation of serological indexes induced by AFB1, and reduced the production of AFBO in liver. II) AFB1-induced increase in CYP450 expression was significantly reduced by FA. The molecular docking results of FA and CYP2A6 showed high fitness score and interaction. III) FA obviously inhibited the production of MDA, and significantly activated the Nrf2/GST pathway and antioxidant enzymes (SOD and GST). IV) AFB1-induced hepatocyte apoptosis, the high expression of p53, bax, cyt-c, caspase-9, caspase-3, and the low expression of bcl-2 were all restored by FA. It has been suggested from these results that FA proved effective against AFB1-induced liver damage in rats via inhibiting CYP450 enzyme, promoting antioxidant pathway Nrf2/GST, activating antioxidant enzymes (SOD and GST), and regulating the mitochondrial pathway.

Research progress on the protection and detoxification of phytochemicals against aflatoxin B1-Induced liver toxicity

Aflatoxin B₁ (AFB₁) is a potent hepatotoxic toxin, which can cause hepatitis, cirrhosis, and liver immunological damage. It has been involved in the etiology of human hepatocellular carcinoma. AFB₁ can cause oxidative stress in the body's metabolism process, and then cause cytotoxicity, such as apoptosis and DNA damage. Scientific research has discovered that phytochemicals can induce the detoxification pathway of AFB₁ through its biotransformation, thereby reducing the damage of AFB₁ to the human body. In clinical treatment, certain phytochemicals have been effectively used in the treatment of liver injury due to the advantages of multiple targets, multiple pathways, low toxicity and side effects. Therefore, the article summarizes the toxic mechanism of AFB₁-induced hepatoxicity, and the related research progress of phytochemicals for preventing and treating its cytotoxicity and genotoxicity. We also look forward to the existing problems and application prospects of phytochemicals in the pharmaceutical industry, in order to provide theoretical reference for the prevention and treatment of AFB₁ poisoning in future research work.

ACVIM consensus statement on the diagnosis and treatment of chronic hepatitis in dogs

This consensus statement on chronic hepatitis (CH) in dogs is based on the expert opinion of 7 specialists with extensive experience in diagnosing, treating, and conducting clinical research in hepatology in dogs. It was generated from expert opinion and information gathered from searching of PubMed for manuscripts on CH, the Veterinary Information Network for abstracts and conference proceeding from annual meetings of the American College of Veterinary Medicine and the European College of Veterinary Medicine, and selected manuscripts from the human literature on CH. The panel recognizes that the diagnosis and treatment of CH in the dog is a complex process that requires integration of clinical presentation with clinical pathology, diagnostic imaging, and hepatic biopsy. Essential to this process is an index of suspicion for CH, knowledge of how to best collect tissue samples, access to a pathologist with experience in assessing hepatic histopathology, knowledge of reasonable medical interventions, and a strategy for monitoring treatment response and complications.

Water-soluble substances of wheat: a potential preventer of aflatoxin B1-induced liver damage in broilers

Aflatoxin B1 (AFB1) is very harmful for broiler production and public health. The water-soluble castoff in gluten production, i.e., the water-soluble substances of wheat (WSW) that contains 14% pentosan has positive effect on animal nutrient absorption, immunity, and antioxidation. Our study aims to investigate the preventive effects of WSW against AFB1-induced broiler liver injury. One day-old Arbor Acres broilers were randomly separated to 4 groups and were, respectively, fed with control diet, diet with 5 mg/kg AFB1 standard, diet with 5 mg/kg AFB1 standard and 214 ml/kg WSW, and diet with 214 ml/kg WSW continuously for 28 d. The histopathological, ultra-structural, and serological changes were tested to evaluate liver damage. The hallmarks of hepatocellular autophagy, apoptosis, and inflammation were measured by Western Blot and real-time polymerase chain reaction. The content of AFB1 in chicken liver was detected with an ultra-high performance liquid chromatography linked with the fluorescence detection method. The results showed that (i) WSW restored AFB1-induced changes in serum biochemical parameters, and ameliorated histomorphological changes in hepatocytes, (ii) WSW reduced the content of AFB1 in chicken liver, (iii) WSW alleviated AFB1-induced autophagy inhibition by up-regulating hepatic LC3, beclin-1, and down-regulating hepatic mTOR and cytoplasmic P53 expressions, (iv) WSW alleviated AFB1-induced hepatocellular apoptosis via inhibiting pro-apoptotic gene expression (nuclear P53, Caspase3, Bax), and promoting anti-apoptotic gene expression (bcl-2), (v) WSW feeding ameliorated AFB1-induced liver inflammation via impeding TLR4/NF-${{\bf \kappa }}$B and IL-1/NF-${{\bf \kappa }}$B signaling pathways, down-regulating pro-inflammatory cytokines (IL-1${{\bf \beta }}$, IL-6, and IL-8), and markedly up-regulating anti-inflammatory genes (IL-10 and HO-1). Conclusively, WSW is a potential preventer of AFB1-induced broiler liver damage by reducing the AFB1 content in liver, accelerating hepatocellular autophagy and inhibiting hepatocytes apoptosis and liver inflammation.

Clinicopathological Correlation and Prevalence of Increased Copper in Canine Hepatic Cytology

Special staining and grading of canine liver cytology samples aids in detection of increased copper content. The prevalence of copper in routine diagnostic liver cytology samples, clinical findings associated with high cytologic copper (cCu) grade, and the correlation between cCu grade and histologic findings, including histologic copper (hCu) grade, are unknown. This data may be helpful in ascertaining when to determine a cCu grade and when interpreting cCu grade. Clinical data and available archived hepatic histologic and cytologic samples from 198 dogs were collected, evaluated, rhodanine stained, and graded for copper. Prevalence of increased cCu >5 in a randomly collected group of 163 individuals, and the correlation between cCu and clinical data (n = 198), hCu grade (n = 37), or findings on hematoxylin and eosin-stained hepatic sections (n = 32) were evaluated. The observed prevalence was 1.23%. Dogs with elevated alanine transaminase >180 IU/L or aspartate transaminase >90 IU/L and patients who subsequently had hepatic copper quantification were statistically more likely to have pathologic levels of copper detected by cytology. There was significant and modest correlation between cCu and hCu, interface hepatitis, portal inflammation, and fibrosis. Evidence of hepatocellular leakage may be indications for determination of cCu.

Isopropyl Caffeate: A Caffeic Acid Derivative-Antioxidant Potential and Toxicity

Phenolic compounds, among them isopropyl caffeate, possess antioxidant potential, but not without toxicity and/or adverse effects. The present study aimed to evaluate the antioxidant activity and toxicity of isopropyl caffeate through in silico, in vitro and in vivo testing. The results showed that isopropyl caffeate presents no significant theoretical risk of toxicity, with likely moderate bioactivity: GPCR binding, ion channel modulation, nuclear receptor binding, and enzyme inhibition. Isopropyl caffeate induced hemolysis only at the concentrations of 500 and 1000 μg/ml. We observed types A and O erythrocyte protection from osmotic stress, no oxidation of erythrocytes, and even sequestrator and antioxidant behavior. However, moderate toxicity, according to the classification of GHS, was demonstrated through depressant effects on the central nervous system, though there was no influence on water and food consumption or on weight gain, and it did present possible hepatoprotection. We conclude that the effects induced by isopropyl caffeate are due to its antioxidant activity, capable of preventing production of free radicals and oxidative stress, a promising molecule with pharmacological potential.

Diagnostic accuracy of Wright-Giemsa and rhodanine stain protocols for detection and semi-quantitative grading of copper in canine liver aspirates

BACKGROUND

Canine hepatic copper content has been increasing. Recognition of canine copper-associated hepatopathies is becoming more common.

OBJECTIVES

The purpose of the study was to assess the diagnostic performance of Wright-Giemsa (WG) and rhodanine staining for detection of increased canine hepatic copper following a proposed cytologic protocol for semi-quantitative evaluation of liver aspirates and the effect of previous WG staining.

METHODS

Retrospectively, 40 canine hepatic WG-stained cytology cases were rhodanine stained. Diagnostic performance of WG staining for increased hepatic copper was evaluated. A rhodanine-stained cytologic copper grading system was developed. Prospectively, 67 canine liver samples with quantitative copper measurement, a WG-then rhodanine-stained slide, and a non-WG rhodanine-stained slide were used to assess the performance of the grading system and the effect of previous WG staining.

RESULTS

Copper was not described in 40 retrospective cases on initial cytologic evaluation; 8/40 cases had increased copper content after rhodanine staining or quantitative copper assessment. Prior WG staining and destaining significantly affected the cytologic copper grade but not the diagnostic performance as measured by receiver-operating characteristic curve analysis. Quantitative copper concentration and previously WG-stained copper grade were moderately correlated (n = 67, ρ = .79 [.68-.87]). For detection of ≥ 600 ppm, dry weight (dw) copper, sensitivity was .75 and specificity was .97. For detection of ≥ 1500 ppm, dw copper, sensitivity was 1.0 and specificity was .97.

CONCLUSIONS

Wright-Giemsa staining alone does not reliably detect hepatic copper. Grading of rhodanine-stained canine hepatic cytologic samples demonstrates acceptable diagnostic performance for detection of copper content.

Tamoxifen induces hepatotoxicity and changes to hepatocyte morphology at the early stage of endocrinotherapy in mice

Clinically, hepatotoxicity is an inevitable side effect during long-term endocrinotherapy in breast cancer patients. Various studies have reported the specific mechanism and protective methods for this long-term hepatotoxicity, however, the short-term influences of tamoxifen (TAM) on hepatocytes remain to be elucidated. The previous study investigated TAM-induced liver injury at the early stage of endocrine treatment. Mice were assigned into 2 groups: The experiment group was administrated with intraperitoneal (i.p.) injection of 6 mg/kg/day TAM for 2 weeks, and the control group was administrated with i.p. injection of physiological saline of the same dose. Body weights in each group were detected every day, and alanine aminotransferase and aspartate aminotransferase levels were measured every 3 days. Small pieces of the liver tissues were obtained and processed for protein extraction, biochemical detection and histopathological analysis 2 weeks later. The results indicated that TAM decreased the mice body weights. Morphologically, with the treatment of TAM for only 2 weeks, at the microscopic and ultrastructural levels the structure of hepatic cords became blurred in sections of the regions, although the lobules of the liver remained visible. Partially, hepatic cells were swelled in spherical shapes. Nuclei appeared to be pyknotic and exhibited uneven chromatin distribution. In addition, it was observed in the transmission electron microscopy analysis that nuclei became pyknotic and unevenly distributed. The majority of the nuclei were endowed with distinct heterochromatin and thick nucleoli. The mitochondrial cristae became vague and disorganized. Finally, western blotting was used and detected a significant increase of the caspase-3 level in the liver tissues. In conclusion, the experiments elucidated that TAM (6 mg/kg/day) would cause hepatotoxicity at the early stage of endocrine treatment in mice, and the underlying mechanism was involved with hepatocyte apoptosis.