HFD enhances HCC progression and modulates the immune response in the liver microenvironment. HFD induced changes in macrophage polarization with increased numbers of TNFa-positive macrophages in the liver. HFD reduces T cell infiltration to liver area in NASHassociated HCC larvae. Ablation of macrophages reduces disease progression in NASH-associated HCC larvae, but not in HCC alone. Metformin specifically affects the progression induced by diet in NASH-associated HCC in zebrafish.

Tissue damage induces rapid recruitment of leukocytes and changes in the transcriptional landscape that influence wound healing. However, the cell-type specific transcriptional changes that influence leukocyte function and tissue repair have not been well characterized. Here, we employed translating ribosome affinity purification (TRAP) and RNA sequencing, TRAP-seq, in larval zebrafish to identify genes differentially expressed in neutrophils, macrophages, and epithelial cells in response to wounding. We identified the complement pathway and c3a.1, homologous to the C3 component of human complement, as significantly increased in neutrophils in response to wounds. c3a.1−/− zebrafish larvae have impaired neutrophil directed migration to tail wounds with an initial lag in recruitment early after wounding. Moreover, c3a.1−/− zebrafish larvae have impaired recruitment to localized bacterial infections and reduced survival that is, at least in part, neutrophil mediated. Together, our findings support the power of TRAP-seq to identify cell type specific changes in gene expression that influence neutrophil behavior in response to tissue damage.

Neutrophil recruitment to tissue damage is essential for host defense but can also impede tissue repair. The cues that differentially regulate neutrophil responses to tissue damage and infection remain unclear. Here, we report that the paracrine factor myeloid-derived growth factor (MYDGF) is induced by tissue damage and regulates neutrophil motility to damaged, but not infected, tissues in zebrafish larvae. Depletion of MYDGF impairs wound healing, and this phenotype is rescued by depleting neutrophils. Live imaging and photoconversion reveal impaired neutrophil reverse migration and inflammation resolution in mydgf mutants. We found that persistent neutrophil inflammation in tissues of mydgf mutants was dependent on the HIF-1α pathway. Taken together, our data suggest that MYDGF is a damage signal that regulates neutrophil interstitial motility and inflammation through a HIF-1α pathway in response to tissue damage.

Fibrolamellar Carcinoma (FLC) is a rare liver cancer that affects adolescents and young adults. Genomic analysis in FLC has revealed a 400 kB deletion in chromosome 19 that leads to a fusion protein, DNAJB1-PRKACA (DnaJ-PKAc) comprised of the first exon of the heat shock protein 40 (DNAJB1) and exons 2–10 of the catalytic subunit of protein kinase A (PRKACA). Here, we report a new zebrafish model of FLC induced by ectopic expression of zebrafish DnaJa-Pkaca (zfDnaJ-Pkaca) in hepatocytes that is amenable to live imaging of early innate immune inflammation. Expression of zfDnaJ-Pkaca in hepatocytes induces hepatomegaly and increased hepatocyte size. In addition, FLC larvae exhibit early innate immune inflammation characterized by early infiltration of neutrophils and macrophages into the liver microenvironment. Increased caspase-a activity was also found in the liver of FLC larvae, and pharmacological inhibition of TNFα and caspase-a decreased liver size and inflammation. Overall, these findings show that innate immune inflammation is an early feature in a zebrafish model of FLC and that that pharmacological inhibition of TNFα or caspase-1 activity might be targets to treat inflammation and progression in FLC.

An 11-year-old neutered male Alaskan Malamute mixed-breed dog was presented with a complaint of polyuria/polydipsia (PU/PD), weight loss, tachypnea, regurgitation, and a previous history of nontreated osteosarcoma of the right distal radius, diagnosed 21 months prior. On physical examination, an abdominal mass was palpated. The abdominal mass was aspirated and cytologically diagnosed as a neuroendocrine tumor, suspected to be a pheochromocytoma. Laboratory examination revealed a mild anemia and thrombocytopenia, markedly elevated ATP and ALP activities, and moderate hypercalcemia. A low-dose dexamethasone suppression test and endogenous adrenocorticotropic hormone (ACTH) concentration were compatible with pituitary hyperadrenocorticism. On urinalysis, proteinuria was noted as well as a high urine metanephrine/creatinine ratio, consistent with a diagnosis of pheochromocytoma. The dog was treated with supportive care and euthanized 6 months later due to decreasing quality of life. On necropsy, an extra-adrenal pheochromocytoma (paraganglioma) was diagnosed in the caudal abdomen, and a pituitary adenoma and an osteosarcoma of the right distal radius were confirmed.

Abbreviations used in this paper: NAFLD, Nonalcoholic fatty liver disease; NASH, nonalcoholic steatohepatitis; HCC, hepatocellular carcinoma; HCD, high-cholesterol diet; TME, tumor microenvironment; TNF, tumor necrosis factor; dpf, days post-fertilization; ND, normal diet; MTZ, metronidazole; NTR, nitroreductase. AbstractDiabetes and obesity have been associated with nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH) and increased incidence of hepatocellular carcinoma (HCC). Here we use optically transparent zebrafish to visualize liver inflammation and disease progression in a NAFLD/NASH-HCC model. We combined a high-cholesterol diet (HCD) with a transgenic zebrafish HCC model induced by hepatocyte-specific activated βcatenin and found that diet induced an increase in liver size and enhanced angiogenesis and neutrophil infiltration in the liver. Although macrophage number was not affected by diet, HCD induced changes in macrophage morphology and polarization with an increase in liver associated TNFα-positive macrophages. Treatment with metformin altered macrophage polarization and reduced liver size in NAFLD/NASH-associated HCC larvae. Moreover, ablation of macrophages limited progression in NAFLD/NASH-associated HCC larvae but not in HCC alone. These findings suggest that HCD alters macrophage polarization and exacerbates the liver inflammatory microenvironment and cancer progression in a zebrafish model of NAFLD/NASH-associated HCC.

Urinalysis results for clinically normal chinchillas were provided. For chinchilla urine samples, measurement of USG by refractometry prior to centrifugation is acceptable and protein concentration should be determined by quantitative protein analysis rather than dipstick analysis or the SSA test.

Biomarker responses and histopathological lesions have been documented in laboratory mammals exposed to elevated concentrations of lead and cadmium. The exposure of white-footed mice (Peromyscus leucopus) to these metals and the potential associated toxic effects were examined at three contaminated sites in the Southeast Missouri Lead Mining District and at a reference site in MO, USA. Mice from the contaminated sites showed evidence of oxidative stress and reduced activity of red blood cell δ-aminolevulinic acid dehydratase (ALAD). Histological examinations of the liver and kidney, cytologic examination of blood smears, and biomarkers of lipid peroxidation and DNA damage failed to show indications of toxic effects from lead. The biomagnification factor of cadmium (hepatic concentration/soil concentration) at a site with a strongly acid soil was 44 times the average of the biomagnification factors at two sites with slightly alkaline soils. The elevated concentrations of cadmium in the mice did not cause observable toxicity, but were associated with about a 50% decrease in expected tissue lead concentrations and greater ALAD activity compared to the activity at the reference site. Lead was associated with a decrease in concentrations of hepatic glutathione and thiols, whereas cadmium was associated with an increase. In addition, to support risk assessment efforts, we developed linear regression models relating both tissue lead dosages (based on a previously published a laboratory study) and tissue lead concentrations in Peromyscus to soil lead concentrations.