Lytic Necrosis Research Articles

The hepatoprotective potential of nigella sativa oil against cypermethrin-induced hepatotoxicity in rats: A histomorphological investigation.

Objective: To determine the hepatotoxic effects induced by cypermethrin. The study also attempts to evaluate the hepatoprotective efficacy of Nigella sativa oil against hepatotoxicity produced by cypermethrin. Study Design: Experimental study. Setting: Department of Anatomy, Pharmacology, and Pathology of Peshawar Medical College and Animal house of PCSIR Laboratories Complex, Peshawar. Period: May 2023 to Dec 2023. Methods: Animals were divided into two groups: Control (Group A) and Experimental (Group B). The Experimental group (Group B) is divided into two subgroups Group B-I and Group B-II. Forty-two male Sprague Dawley rats were randomly assigned to three groups of fourteen rats each in order to conduct an experimental investigation. Group A served as a control group. Cypermethrin (5.5mg/kg‾¹ body weight) per day dissolved in corn oil was administered orally to Group B-I. Cypermethrin (5.5 mg/kg‾¹ body weight) per day orally and (1ml/kg‾¹ body weight) per day of Nigella sativa oil were given to group B-II. Liver obtained from these groups were fixed for histological studies under light microscopy. Liver tissues of the cypermethrin-treated animals showed leucocytic infiltration, hydropic alterations such as ballooning degeneration and focal lytic (spotty) liver necrosis. Results: After four weeks of treatment with cypermethrin demonstrated significant liver damage in group B-I animals. In group B-II Nigella sativa oil significantly reduced hepatotoxicity and induced regenerative changes. Nigella sativa oil demonstrated protection against the cypermethrin and preserved the normal histological architecture of the liver. Conclusion: Cypermethrin had a hepatotoxic potential and caused hepatotoxicity in liver, as evidenced by the histological changes in the liver tissue. However, the study also found that Nigella sativa oil showed a better hepatoprotective effect, as it was able to effectively reverse the liver damage caused by both cypermethrin.

Naturally occurring psittacid alphaherpesvirus 3 and probable adenovirus coinfection in an Indian ringneck parakeet in the United States.

Psittacid alphaherpesvirus 3 (PsAHV-3) is a rarely reported virus that has been associated with pneumonia in psittacine birds. A 5-mo-old Indian ringneck parakeet (syn. rose-ringed parakeet; Psittacula krameri) was euthanized after developing torticollis and lethargy. Postmortem examination of the parakeet revealed severe pneumonia with syncytial cells containing eosinophilic intranuclear inclusion bodies (INIBs) in the respiratory epithelium. Gene sequencing of total DNA extraction detected PsAHV-3 in the frozen lung. The pancreas had severe lytic necrosis, with the remaining parenchymal cells expanded by large basophilic INIBs. Electron microscopy of the pancreas revealed intranuclear paracrystalline arrays of viral particles morphologically resembling adenovirus. Although we found 3 PsAHV-3 cases in birds in a literature search, we found no cases with adenoviral coinfection.

Experimental Yellow Fever in Squirrel Monkey: Characterization of Liver In Situ Immune Response.

Non-human primates contribute to the spread of yellow fever virus (YFV) and the establishment of transmission cycles in endemic areas, such as Brazil. This study aims to investigate virological, histopathological and immunohistochemical findings in livers of squirrel monkeys (Saimiri spp.) infected with the YFV. Viremia occurred 1-30 days post infection (dpi) and the virus showed a predilection for the middle zone (Z2). The livers were jaundiced with subcapsular and hemorrhagic multifocal petechiae. Apoptosis, lytic and coagulative necrosis, steatosis and cellular edema were also observed. The immune response was characterized by the expression of S100, CD11b, CD57, CD4 and CD20; endothelial markers; stress and cell death; pro and anti-inflammatory cytokines, as well as Treg (IL-35) and IL-17 throughout the experimental period. Lesions during the severe phase of the disease were associated with excessive production of apoptotic pro-inflammatory cytokines, such as IFN-γ and TNF-α, released by inflammatory response cells (CD4+ and CD8+ T lymphocytes) and associated with high expression of molecules of adhesion in the inflammatory foci observed in Z2. Immunostaining of the local endothelium in vascular cells and the bile duct was intense, suggesting a fundamental role in liver damage and in the pathogenesis of the disease.

PECTIN MODULATES HEMATO-BIOCHEMICAL PARAMETER, HISTOPATHOLOGY, OXIDATIVE STRESS BIOMARKERS, CYTOKINES AND EXPRESSION OF HEPCIDN GENE IN LEAD INTOXICATED RATS

Publications concerning the protective effect of pectin against lead induced toxicity in rats are not available. In order to study such effect, 40 male rats were divided into 3 groups. The first group was contained 10 rats that kept as control group. The second group was contained 10 rats that received pectin at dose of 100 mg/kg BW during experimental period (8 weeks). The third group was contained 20 rats that received 400mg/kg BW of lead acetate daily for 4 weeks then divided into two subgroups (3A and 3B). Subgroup 3A contained 10 rats that still receive lead acetate in the same dosage whereas, subgroup B co-treated with lead acetate and pectin daily for another 4 weeks. Blood samples were collected after 2, 4 and 8 weeks from the start of the experiment. Liver, kidney and bone marrows were collected only at the end of the experiment. Lead acetate induced anemia only after 4 weeks of administration as reflected on decreased values of Hb, PCV, MCV, MCH and MCHC. These indices remained at lower levels in lead acetate treated groups until the end of the experiment. Concentrations of serum ferritin, iron, total antioxidant capacity (TAC) and reduced glutathione (GSH) and the expression of hepatic hepcidin gene were decreased significantly in lead acetate intoxicated rats compared to control. Activities of ALT and AST and concentrations of urea, creatinine, Nitric oxide (NO), TNF-α, IL-6, total iron binding capacity (TIBC) and lead were increased significantly in lead acetate intoxicated group compared to control. Hepatic degeneration and hemorrhage, renal lytic necrosis and apoptosis of myeloid cells were most prominent changes in lead intoxicated rats. Lead acetated related changes were improved by co-treatment with pectin however; normal control values have not been achieved. Conclusively, pectin is recommended to protect against lead acetate toxicity in rats. Key words: lead acetate; toxicity; pectin; hepcidin; oxidative stress biomarkers; histopathology

Abstract A030: Investigating the feasibility of in-vivo histotripsy ablation for osteosarcoma using an orthotopic murine model and a canine model of spontaneous disease

Abstract Osteosarcoma (OS) is the most commonly occurring primary bone tumor in pediatric cancer patients and dogs, with estimated incidences of 3-4 cases per 1 million and 14 cases per 100,000, respectively. The biological similarities shared between human and canine OS and increased OS prevalence in dogs allows the dog to serve as an effective comparative oncology research model. Current standard of care treatment results in a 70% median 5-year survival for humans and a 10-12-month median survival for dogs, and these survival expectations have not improved in 30 years. There is a critical need for novel treatment options to improve the prognosis for OS patients. The objective of this study was to investigate the ablative (murine, canine) and immunological (canine) effects of histotripsy, a novel focused ultrasound tissue ablation technique, for OS. We utilized orthotopic xenograft murine models with induced canine (D17) or human (143B) OS tumors. Ablative outcomes were assessed grossly and microscopically via histopathological evaluation, and treatment effects on limb functionality were evaluated by monitoring lameness, grip capacity, nesting behavior, and body weight for the duration of the study. Fifteen client-owned dogs with suspected OS were enrolled into a clinical trial and underwent histotripsy treatment 24 hours prior to standard of care limb amputation surgery. Ablative outcomes were assessed grossly and microscopically via histopathological evaluation after surgical excision of treated tumors. Immunological outcomes were evaluated by peripheral blood samples collected pretreatment, 24 hours, and 2 weeks post treatment for immune cell phenotyping via flow cytometry to evaluate the systemic immune response. Locally, changes in the tumor immune microenvironment were assessed at both the cellular and molecular levels. Targeted ablation of the tumor tissue was achieved in both the murine models and the canine patients. Ablation was evident by gross and microscopic evaluation where loss of cellular architecture, lytic and coagulative necrosis and delineation of treated and untreated tumor regions were observed. In the mice, decreased limb function due to inflammation after histotripsy ablation resolved within 5-7 days post treatment. The dogs did not exhibit any increase in lameness after histotripsy ablation. The only clinical adverse event experienced by canine patients was mild transient dermal erythema at the treatment site. Our results suggest systemic immunomodulation evident by increases in CD4+ and CD8+ T lymphocyte populations post treatment and changes in monocyte expression of CD62L and CD80. Locally, we observed an upregulation in genes related to chemotaxis, regulation of inflammation, and immunogenic cell death in treated tumor samples compared to untreated samples. In conclusion our preliminary results suggest that histotripsy treatment has both immunotherapeutic and ablative potential and support the development of histotripsy as a tumor ablation technique and immunotherapeutic for OS. Citation Format: Alayna N. Hay, Lauren Ruger, Haleigh Hixson, Jessica Gannon, Alex Simon, Hannah Sheppard, Sheryl Coutermarsh-Ott, Elaina Davis, Katharine Kierski, Brittany Ciepluch, Nathan Neufeld, Eli Vlaisavljevich, Joanne Tuohy. Investigating the feasibility of in-vivo histotripsy ablation for osteosarcoma using an orthotopic murine model and a canine model of spontaneous disease [abstract]. In: Proceedings of the AACR Special Conference: Sarcomas; 2022 May 9-12; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(18_Suppl):Abstract nr A030.

Non-hepatotropic viral hepatitis and its causative pathogens: The ongoing need for monitoring in children with severe acute hepatitis of unknown etiology.

Non-hepatotropic viral hepatitis and its causative pathogens: The ongoing need for monitoring in children with severe acute hepatitis of unknown etiology.

Role of Th17 Cytokines in the Liver's Immune Response during Fatal Yellow Fever: Triggering Cell Damage Mechanisms.

Yellow fever (YF) is an infectious and acute viral haemorrhagic disease that triggers a cascade of host immune responses. We investigated the Th17 cytokine profile in the liver tissue of patients with fatal YF. Liver tissue samples were collected from 26 deceased patients, including 21 YF-positive and 5 flavivirus-negative patients, with preserved hepatic parenchyma architecture, who died of other causes. Histopathological and immunohistochemical analysis were performed on the liver samples to evaluate the Th17 profiles (ROR-γ, STAT3, IL-6, TGF-β, IL-17A, and IL-23). Substantial differences were found in the expression levels of these markers between the patients with fatal YF and controls. A predominant expression of Th17 cytokine markers was observed in the midzonal region of the YF cases, the most affected area in the liver acinus, compared with the controls. Histopathological changes in the hepatic parenchyma revealed cellular damage characterised mainly by the presence of inflammatory cell infiltrates, Councilman bodies (apoptotic cells), micro/macrovesicular steatosis, and lytic and coagulative necrosis. Hence, Th17 cytokines play a pivotal role in the immunopathogenesis of YF and contribute markedly to triggering cell damage in patients with fatal disease outcomes.

Abstract 822: Oncogene addiction to GNAS in GNASR201 mutant tumors

Abstract Background: The GNASR201 mutation is the single most frequent cancer-causing mutation across all heterotrimeric G proteins. This gain of function mutation in GNAS drives oncogenesis in appendiceal, colorectal, and gastric adenocarcinoma, as well as Intraductal Papillary Mucinous Neoplasms (IPMN) and Small Cell Lung Cancer (SCLC). In this study, we investigated the role of GNAS in tumor growth using peritoneal models of colorectal cancer (CRC). Methods: GNAS was knocked out in multiple GNASR201C/H mutant colon cell lines (KM12, SNU175, and SKCO1) and overexpressed in GNASWT LS174T cells. Isogenic pairs of KM12 and LS174T cells were injected into the peritoneum of NSG mice to study the role of GNAS in cell line derived xenograft (CDX) models of peritoneal metastasis. Cell lines and CDX were profiled with RNAseq, reverse phase protein assay (RPPA), and immunohistochemistry (IHC) to identify potential pathways regulated by mutant GNAS. Identified mediators of GNAS signaling were then validated using chemical inhibitors of PKA (H-89) and β-catenin (LF3). Results: GNAS knockout significantly decreased 2D colony formation by KM12 (68%), SNU175 (76%), and SKCO1 (85%) cells (all p < 0.0001), and decreased 3D organoid area of KM12 cells by 62% (p = 0.043). There was significant increase in colony formation by LS174T cells overexpressing GNASR201C (193%, p = 0.016) and GNASR201H (170%, p =0.0037). Mice injected with KM12 GNAS-knockout tumors exhibited a significant 68% reduction in tumor growth (n = 6, p = 0.016) and were more likely to survive at 7 weeks (0% vs. 100%, p = 0.0007) relative to those with parent KM12-GNASR201H tumors. Likewise, mice injected with GNASR201H LS174T cells showed significant increase in tumor growth (934% vs. 100%, n = 3, p = 0.042). Histology of GNAS-knockout tumors showed a marked decrease in mucinous stroma and increased lytic necrosis, suggesting an interaction between oncogenic GNAS signaling and the peritoneal environment. GNAS is known to stimulate adenylate cyclase and GNAS knockout decreased levels of cyclic AMP in KM12 cells, confirming an on-target effect. RPPA and RNAseq profiling of KM12 and LS174T PDX tumors identified phosphorylation of β-catenin and activation of Wnt/β-catenin targets (NES = 1.25, 1.24) as critical downstream effects of mutant GNAS signaling, confirmed by a 4.9-fold (p = 0.001) increase in nuclear β-catenin intensity in LS174T GNASR201H tumors (19% vs. 99% nuclei stained positive, p = 0.0002). Chemical inhibition of both PKA and β-catenin reduced growth of GNAS mutant organoids by 79% (p = 0.004) and 67% (p = 0.007) respectively, supporting the involvement of the cAMP/PKA and β-catenin pathways in mutant GNAS signaling. Conclusions: Our findings demonstrate oncogene addiction to GNAS in peritoneal models of GNASR201C/H tumors, which signal through the cAMP/PKA and Wnt/β-catenin pathways. Thus, GNAS and its downstream mediators are promising therapeutic targets for GNAS mutant tumors. Citation Format: Aditya More, Valsala Haridas, Ichiaki Ito, Saikat Chowdhury, Yue Gu, Natalie W. Fowlkes, John P. Shen. Oncogene addiction to GNAS in GNASR201 mutant tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 822.

Spontaneous outbreak of Yersinia enterocolitica infection and co-infection with Escherichia coli in black-tufted marmosets (Callithrix penicillata)

Yersiniosis is a zoonotic bacterial disease that affects humans and animals, including primates. The aim of the study was to report one case of fatal Yersinia enterocolitica infection and two cases of co-infection with Escherichia coli in captive black tufted marmosets (Callithrix penicillata) in Apucarana, Paraná, south Brazil. The affected animals presented severe diarrhea and progressed to death. Gross examination showed multifocal to coalescing necrosis in the liver, mild diffuse hepatomegaly, mild diffuse necrotizing enteritis, moderate splenomegaly and focally extensive hyperemia of the leptomeninges. Microscopically, the liver lesions comprised multifocal areas of lytic necrosis with intralesional colonies of gram-negative coccobacilli, characterizing a severe, random, multifocal to coalescing necrotizing hepatitis. A moderate multifocal lymphocytic cholangiohepatitis, severe focally extensive mucosal necrosis in the small intestine, and mild multifocal lymphoplasmacytic leptomeningitis in the brain were observed. Two cases of co-infection by Y. enterocolitica and E. coli, and one case by Y. enterocolitica were confirmed through bacterial culture, biochemical characteristics and 16S rRNA. To the best of the author’s knowledge, it is the first report of an infection of Y. enterocolitica and co-infection with E. coli in black-tufted marmosets resulting in diarrhea, septicemia and death.

Naegleria fowleri Induces Jurkat T Cell Death via O-deGlcNAcylation.

The pathogenic free-living amoeba Naegleria fowleri causes primary amoebic meningoencephalitis, a fatal infection, by penetrating the nasal mucosa and migrating to the brain via the olfactory nerves. N. fowleri can induce host cell death via lytic necrosis. Similar to phosphorylation, O-linked β-N-acetylglucosamine (O-GlcNAc) glycosylation (O-GlcNAcylation) is involved in various cell-signaling processes, including apoptosis and proliferation, with O-GlcNAc addition and removal regulated by O-GlcNAc transferase and O-GlcNAcase (OGA), respectively. However, the detailed mechanism of host cell death induced by N. fowleri is unknown. In this study, we investigated whether N. fowleri can induce the modulation of O-GlcNAcylated proteins during cell death in Jurkat T cells. Co-incubation with live N. fowleri trophozoites increased DNA fragmentation. In addition, incubation with N. fowleri induced a dramatic reduction in O-GlcNAcylated protein levels in 30 min. Moreover, pretreatment of Jurkat T cells with the OGA inhibitor PUGNAc prevented N. fowleri–induced O-deGlcNAcylation and DNA fragmentation. These results suggest that O-deGlcNAcylation is an important signaling process that occurs during Jurkat T cell death induced by N. fowleri.

S3674 Drug-Induced Autoimmune Liver Disease (DIAILD)

Introduction: Idiosyncratic drug-induced liver injury (DILI) affects an estimated 19 per 100,000 persons yearly and is a major cause of acute liver failure. Drug-induced autoimmune liver disease (DIAILD) is a poorly defined and under-reported liver disorder, and probably an underestimated liver disease. A small number of drug-induced liver injury (DILI) cases exhibit features typical of autoimmune hepatitis (AIH). To differentiate between true AIH triggered by drugs (DI-AIH) and immune mediated DILI still remains a challenge. Case Description/Methods: We present a 71-year-old ICU nurse with past medical history of hyperlipidemia, hypothyroidism and GERD presenting for nausea, epigastric pain, and chills. Of note, 5 days prior to onset of symptoms she received her vaccine for COVID-19. Medications that she takes at home are cimetidine, Protonix, Lipitor, Synthroid, Zofran, Vitamin A, and D supplementation. Review of systems were pertinent for mild itching, nausea, and chills. Physical exam is unremarkable except for low grade fevers, scleral icterus, and jaundice. Labs are significant for T.bili 13.5, AST 1673, ALT 2372, ALP 246, INR 1.59, ANA 1:160, AFP 169, CT abdomen/pelvis with and without contrast was unremarkable except for mild constipation. Liver biopsy was obtained that revealed submassive hepatic multilobular necrosis with confluent lytic necrosis and cholestasis involving 60-70% of the cores. Portal triads showed surrounding lymphocytic infiltrate without bile duct involvement and active interface hepatitis. active interface hepatitis, . Per pathology report the histological findings were nonspecific and a diagnosis of drug toxicity is the most compatible with given history. She was started on prednisone 40 mg daily and her liver enzymes started to improve. Discussion: In our patient we attributed the acute liver injury secondary to cimetidine from immune mediated DILI. Initially we speculated that covid 19 vaccine could have attributed to her acute hepatitis. However, at the time there were no other cases reported of Covid 19 related acute liver injury;and it could have coincidentally occurred at the same time. It will be interesting to see in the future if Covid 19 vaccine presents similar to this case. Although it is a clinical challenge to differentiate AIH and DI-AIH;it is important to keep both conditions in your differential.

Measuring Stony Coral Tissue Loss Disease Induction and Lesion Progression Within Two Intermediately Susceptible Species, Montastraea cavernosa and Orbicella faveolata

During the last several decades, Florida’s Coral Reef (FCR) has been impacted by both global and local stressors that have devastated much of its living coral cover. Additionally, since 2014 FCR has experienced a lethal disease outbreak termed stony coral tissue loss disease (SCTLD). Here, we examined SCTLD spreading dynamics within and among fragmented coral colonies and quantified lesion progression rate of two intermediately susceptible species—Montastraea cavernosaandOrbicella faveolata—through induction experiments conducted in laboratory aquaria.M. cavernosacolonies showing subacute tissue loss were sequentially fragmented parallel to the lesion edge to determine whether isolated tissue that showed no tissue-loss signs, referred to as isolated apparently healthy (AH) donor fragments, would subsequently exhibit tissue loss. Additionally, AHM. cavernosaandO. faveolatafragments, referred to as recipient fragments, were placed in direct contact with theM. cavernosadonor fragments to assess incidence of new tissue-loss lesions. Finally, AHM. cavernosadonor fragments were placed in direct contact with recipientM. cavernosaandO. faveolatafragments to account for aggression from direct contact. Samples were collected for histopathology of the corals through time. Many isolated AH donor fragments developed tissue-loss lesions during the 60-day study, suggesting SCTLD may be systemic within small-sized colonies. Our results confirmed that physical contact between recipient fragments and subacute SCTLD-lesioned tissue often led to tissue loss in recipient fragments. None of the control recipient or donor fragments experienced tissue loss. Grossly, multifocal lesions started on or adjacent to the septal and costal basal body walls with tissue loss progressing across the polyp septa and coenenchyme, respectively, in both species. Histologically, initial tissue-loss lesions in both species exhibited characteristic lytic necrosis (LN) at the basal body wall of the gastrodermis.O. faveolataexhibited higher rates of lesion appearance and subsequent mortality compared toM. cavernosa, but once a lesion appeared,M. cavernosalost tissue faster thanO. faveolata.This work contributes to the growing knowledge of SCTLD dynamics and highlights the differences in lesion progression within susceptible species.

Spotty liver disease in Jordan: An emerging disease

Spotty liver disease is an acute bacterial disease that affects the poultry industry throughout the world. In this report, we discuss the first documented outbreak of the recently emerging disease, spotty liver disease, in a poultry flock in Jordan. The clinical history, pathological and molecular findings are described. The outbreak was characterised by recurrent mortalities that subsided with antibiotic treatments. Grossly, there were multiple pinpoint white foci distributed throughout the enlarged liver and less frequently throughout the spleen too. Histologically, the white foci represented areas of acute hepatocellular lytic necrosis and degeneration that were consistent with those of spotty liver disease. An end point polymerase chain reaction (PCR) assay targeting the glycerol kinase gene, coupled with sequencing, confirmed the pathological diagnosis. Continuous surveillance is needed to estimate the prevalence of this disease in Jordanian poultry flocks.

Stony Coral Tissue Loss Disease in Florida Is Associated With Disruption of Host–Zooxanthellae Physiology

Samples from eight species of corals (Colpophyllia natans, Dendrogyra cylindrus, Diploria labyrinthiformis, Meandrina meandrites, Montastraea cavernosa, Orbicella faveolata, Pseudodiploria strigosa, and Siderastrea siderea) that exhibited gross clinical signs of acute, subacute, or chronic tissue loss attributed to stony coral tissue loss disease (SCTLD) were collected from the Florida Reef Tract during 2016–2018 and examined histopathologically. The hallmark microscopic lesion seen in all eight species was focal to multifocal lytic necrosis (LN) originating in the gastrodermis of the basal body wall (BBW) and extending to the calicodermis, with more advanced lesions involving the surface body wall. This was accompanied by other degenerative changes in host cells such as mucocyte hypertrophy, degradation and fragmentation of gastrodermal architecture, and disintegration of the mesoglea. Zooxanthellae manifested various changes including necrosis (cytoplasmic hypereosinophilia, pyknosis); peripheral nuclear chromatin condensation; cytoplasmic vacuolation accompanied by deformation, swelling, or atrophy; swollen accumulation bodies; prominent pyrenoids; and degraded chloroplasts. Polyhedral intracytoplasmic eosinophilic periodic acid–Schiff-positive crystalline inclusion bodies (∼1–10 μm in length) were seen only in M. cavernosa and P. strigosa BBW gastrodermis in or adjacent to active lesions and some unaffected areas (without surface lesions) of diseased colonies. Coccoidlike or coccobacilloidlike structures (Gram-neutral) reminiscent of microorganisms were occasionally associated with LN lesions or seen in apparently healthy tissue of diseased colonies along with various parasites and other bacteria all considered likely secondary colonizers. Of the 82 samples showing gross lesions of SCTLD, 71 (87%) were confirmed histologically to have LN. Collectively, pathology indicates that SCTLD is the result of a disruption of host–symbiont physiology with lesions originating in the BBW leading to detachment and sloughing of tissues from the skeleton. Future investigations could focus on identifying the cause and pathogenesis of this process.

Tripartite-motif family protein 35-28 regulates microglia development by preventing necrotic death of microglial precursors in zebrafish

Microglia are tissue-resident macrophages in the central nervous system (CNS) that play essential roles in the regulation of CNS development and homeostasis. Yet, the genetic networks governing microglia development remain incompletely defined. Here, we report the identification and characterization of a microglia-defective zebrafish mutant wulonghkz12 (wulhkz12 ) isolated from an ethylnitrosourea (ENU)-based genetic screen. We show that wulhkz12 mutants harbors a missense point mutation in the gene region encoding the PRY/SPRY domain of the tripartite-motif family protein 35-28 (trim35-28) gene. Time-lapse imaging revealed that the loss of Trim35-28 function causes lytic necrosis of microglial precursors/peripheral macrophages, as indicated by cytoplasmic swelling and membrane rupture of these precursors and accompanied by neutrophil infiltration and systemic inflammation. Intriguingly, the lytic necrosis of microglial precursors in trim35-28-deficient mutants appeared to depend neither on the canonical pyroptotic nor necroptotic pathways, as inhibition of the key component in each pathway could not rescue the microglia phenotype in trim35-28-deficient mutants. Finally, results from tissue-specific rescue experiments suggested that Trim35-28 acts cell-autonomously in the survival of microglial precursors. Taken together, the findings of our study reveal Trim35-28 as a regulatory protein essential for microglia development.

Endotoxic hepatotoxicity in rats is exacerbated by tacrolimus and diminished by cyclosporine or sirolimus: modulation by androgenic hormones

Liver toxicity contributes to poor prognosis and increased mortality rate in septic and endotoxic patients. Given the discrepant hepatic influences of immunosuppressant therapies, biochemical and histopathological studies were performed to determine whether endotoxic hepatotoxicity is variably altered by calcineurin‐dependent (cyclosporine and tacrolimus) and independent immunosuppressant (sirolimus) in rats. The data showed that 6‐hr treatment of rats with lipopolysaccharide (LPS, 3 mg/kg i.p.) significantly increased serum levels of serum glutamic pyruvic transaminase (sGPT) and glutamic oxaloacetic transaminase (sGOT). Morphologically, livers of endotoxic rats showed evidence of portal tract inflammation, neutrophil infiltration, central vein congestion, and focal lytic necrosis. Except for mild portal inflammation and congestion, these hepatic anomalies were largely compromised in endotoxic rats pretreated 2 hr earlier with cyclosporine (10 mg/kg i.p.) or sirolimus (1 mg/kg i.p.). By contrast, the prior exposure to tacrolimus (2 mg/kg i.p.) accentuated hepatotoxic manifestations of endotoxemia as indicated by the significant elevations in serum sGPT and sGOT beyond endotoxic levels and loss of regular cord arrangement of hepatocytes, apparent bile secretion within bile canaliculi, hemorrhagic areas, cytoplasmic vacuolization, and marked congestion. We also show that functional androgenic pathways seem necessary for the demonstration of hepatotoxic manifestations caused by LPS or its combination with tacrolimus because such effects were remarkably attenuated in rats with surgical (castration) or pharmacologic (flutamide, androgen receptor blocker) testosterone depletion. Our data indicate that immunosuppressants exhibit diverse, calcineurin‐independent, testosterone‐mediated effects on endotoxic hepatotoxicity in male rats.

Molecular Mechanism for Protection Against Liver Failure in Human Yellow Fever Infection.

Yellow fever (YF) is a viral hemorrhagic fever that typically involves the liver. Brazil recently experienced its largest recorded YF outbreak, and the disease was fatal in more than a third of affected individuals, mostly because of acute liver failure. Affected individuals are generally treated only supportively, but during the recent Brazilian outbreak, selected patients were treated with liver transplant. We took advantage of this clinical experience to better characterize the clinical and pathological features of YF‐induced liver failure and to examine the mechanism of hepatocellular injury in YF, to identify targets that would be amenable to therapeutic intervention in preventing progression to liver failure and death. Patients with YF liver failure rapidly developed massive transaminase elevations, with jaundice, coagulopathy, thrombocytopenia, and usually hepatic encephalopathy, along with pathological findings that included microvesicular steatosis and lytic necrosis. Hepatocytes began to express the type 3 isoform of the inositol trisphosphate receptor (ITPR3), an intracellular calcium (Ca2+) channel that is not normally expressed in hepatocytes. Experiments in an animal model, isolated hepatocytes, and liver‐derived cell lines showed that this new expression of ITPR3 was associated with increased nuclear Ca2+ signaling and hepatocyte proliferation, and reduced steatosis and cell death induced by the YF virus. Conclusion: Yellow fever often induces liver failure characterized by massive hepatocellular damage plus steatosis. New expression of ITPR3 also occurs in YF‐infected hepatocytes, which may represent an endogenous protective mechanism that could suggest approaches to treat affected individuals before they progress to liver failure, thereby decreasing the mortality of this disease in a way that does not rely on the costly and limited resource of liver transplantation.

Experimental yellow fever virus infection in the squirrel monkey (Saimiri spp.) I: gross anatomical and histopathological findings in organs at necropsy.

BACKGROUND Non-human primates contribute to the spread of the yellow fever virus (YFV) and the establishment of transmission cycles in endemic areas.OBJECTIVE To describe the severe histopathological aspects of YFV infection, 10 squirrel monkeys were infected with YFV and blood, brain, liver, kidney, spleen, heart, lung, lymph node and stomach were collected at 1-7, 10, 20 and 30 days post-infection (dpi). METHODS Histopathological analysis and detection of the genome and viral antigens and neutralising antibodies were performed by RT-PCR, immunohistochemistry and neutralisation test, respectively. FINDINGS Only one animal died from the experimental infection. The genome and viral antigens were detected in all investigated organs (1-30 dpi) and the neutralising antibodies from seven to 30 dpi. The brain contained perivascular haemorrhage (6 dpi); in the liver, midzonal haemorrhage and lytic necrosis (6 dpi) were observed. The kidney had bleeding in the Bowman’s capsule and tubular necrosis (6 dpi). Pyknotic lymphocytes were observed in the spleen (1-20 dpi), the lung had haemorrhage (2-6 dpi), in the endocardium it contained nuclear pyknosis and necrosis (2-3 dpi) and the stomach contained blood in the lumen (6 dpi). MAIN FINDINGS Squirrel monkeys reliably reproduced the responses observed in human cases of yellow fever and, therefore, constitute an excellent experimental model for studies on the pathophysiology of the disease.

Isolation, identification, and histopathological analysis of Vibrio tubiashii from lined seahorse Hippocampus erectus.

The lined seahorse Hippocampus erectus is an economically important aquaculture species; however, the low survival rate of juvenile seahorses severely restricts their large-scale cultivation. According to previous research, dead juvenile seahorses (4-6 cm) showed symptoms of suspected enteritis, including abdominal depression, raised cloaca, partial hepatic congestion, and yellow sticky liquid filling the intestine. Here, we isolated a Gram-negative bacterium from diseased juvenile seahorses and tentatively named the strain HEL-5. Healthy juvenile seahorses were then challenged with the strain through intraperitoneal injection, with results confirming that HEL-5 was pathogenic for seahorses at a median lethal dose of 5.81 × 105 CFU g-1 fish weight. Based on morphological observations, biochemical characteristics, and sequence analysis of 16S rRNA and housekeeping genes (gyrB, ftsZ, and gapA), we identified HEL-5 as Vibrio tubiashii. Histopathological observations revealed that V. tubiashii was capable of causing lytic necrosis of hepatocytes and forming obvious necrotic foci, and renal pathology was characterized by tubular collapse and tubular epithelial-cell shedding into the lumen accompanied by a large number of inflammatory cells infiltrating the tissues of the intestines and kidneys. Antimicrobial-susceptibility testing showed that the strain was highly sensitive to macrolides, chloramphenicol, sulfonamides, aminoglycosides, and cephalosporins. These findings represent the first report of isolation of V. tubiashii from diseased juvenile seahorses and provide a foundation for the prevention and treatment of vibrio disease in seahorse aquaculture.

Stable gastric pentadecapeptide BPC 157 in the therapy of the rats with bile duct ligation

Recently, stable gastric pentadecapeptide BPC 157 reversed the high MDA- and NO-tissue values to the healthy levels. Thereby, BPC 157 therapy cured rats with bile duct ligation (BDL) (sacrifice at 2, 4, 6, 8 week). BPC 157-medication (10 μg/kg, 10 ng/kg) was continuously in drinking water (0.16 μg/ml, 0.16 ng/ml, 12 ml/rat/day) since awakening from surgery, or since week 4. Intraperitoneal administration was first at 30 min post-ligation, last at 24 h before sacrifice. Local bath BPC 157 (10 µg/kg) with assessed immediate normalization of portal hypertension was given immediately after establishing portal hypertension values at 4, 6, 8 week. BPC 157 therapy markedly abated jaundice, snout, ears, paws, and yellow abdominal tegmentum in controls since 4th week, ascites, nodular, steatotic liver with large dilatation of main bile duct, increased liver and/or cyst weight, decreased body weight. BPC 157 counteracts the piecemeal necrosis, focal lytic necrosis, apoptosis and focal inflammation, disturbed cell proliferation (Ki-67-staining), cytoskeletal structure in the hepatic stellate cell (α-SMA staining), collagen presentation (Mallory staining). Likewise, counteraction includes increased AST, ALT, GGT, ALP, total bilirubin, direct and indirect and decreased albumin serum levels. As the end-result appear normalized MDA- and NO-tissue values, next to Western blot of NOS2 and NOS3 in the liver tissue, and decreased IL-6, TNF-α, IL-1β levels in liver tissue. Finally, although portal hypertension is sustained in BDL-rats, with BPC 157 therapy, portal hypertension in BDL-rats is either not even developed or rapidly abated, depending on the given BPC 157's regimen. Thus, BPC 157 may counteract liver fibrosis and portal hypertension.