Bax inhibitor-1 protects from nonalcoholic steatohepatitis by limiting inositol-requiring enzyme 1 alpha signaling in mice.

Endoplasmic reticulum (ER) stress is activated in nonalcoholic fatty liver disease (NAFLD), raising the possibility that ER stress-dependent metabolic dysfunction, inflammation, and cell death underlie the transition from steatosis to steatohepatitis (nonalcoholic steatohepatitis; NASH). B-cell lymphoma 2 (BCL2)-associated X protein (Bax) inhibitor-1 (BI-1), a negative regulator of the ER stress sensor, inositol-requiring enzyme 1 alpha (IRE1α), has yet to be explored in NAFLD as a hepatoprotective agent. We hypothesized that the genetic ablation of BI-1 would render the liver vulnerable to NASH because of unrestrained IRE1α signaling. ER stress was induced in wild-type and BI-1-/- mice acutely by tunicamycin (TM) injection (1 mg/kg) or chronically by high-fat diet (HFD) feeding to determine NAFLD phenotype. Livers of TM-treated BI-1-/- mice showed IRE1α-dependent NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation, hepatocyte death, fibrosis, and dysregulated lipid homeostasis that led to liver failure within a week. The analysis of human NAFLD liver biopsies revealed BI-1 down-regulation parallel to the up-regulation of IRE1α endoribonuclease (RNase) signaling. In HFD-fed BI-1-/- mice that presented NASH and type 2 diabetes, exaggerated hepatic IRE1α, X-box binding protein 1 (XBP1), and C/EBP homologous protein (CHOP) expression was linked to activated NLRP3 inflammasome and caspase-1/-11. Rises in interleukin (IL)-1ß, IL-6, monocyte chemoattractant protein 1 (MCP1), chemokine (C-X-C motif) ligand 1 (CXCL1), and alanine transaminase (ALT)/aspartate transaminase (AST) levels revealed significant inflammation and injury, respectively. Pharmacological inhibition of IRE1α RNase activity with the small molecules, STF-083010 or 4µ8c, was evaluated in HFD-induced NAFLD. In BI-1-/- mice, either treatment effectively counteracted IRE1α RNase activity, improving glucose tolerance and rescuing from NASH. The hepatocyte-specific role of IRE1α RNase activity in mediating NLRP3 inflammasome activation and cell death was confirmed in primary mouse hepatocytes by IRE1α axis knockdown or its inhibition with STF-083010 or 4µ8c. CONCLUSION: Targeting IRE1α-dependent NLRP3 inflammasome signaling with pharmacological agents or by BI-1 may represent a tangible therapeutic strategy for NASH. (Hepatology 2018).

First Description of Infection of Caprine Herpesvirus 1 (CpHV-1) in Goats in Mainland France.

The purpose of this study was to investigate the epidemiological situation of the caprine herpesvirus 1 (CpHV-1) infection in nine districts in mainland France, mostly in the south, near Italy or Spain, where high seroprevalence has been observed. Two more central areas were also included in the study. The serosurvey was carried out in 9564 goats (275 herds) using bovine herpesvirus 1 (BoHV-1) glycoprotein B and E ELISAs. To confirm the presence of specific CpHV-1 antibodies, some of the samples were tested in neutralization assay. Results demonstrate, for the first time, CpHV-1 infection in goat herds on the French mainland. The analysis found cases of alphaherpesviruses infection in each district studied, with different levels of seroprevalence observed within each district (ranging from 0.2% to 31.56% at an individual level and from 9% to 46.2% for herd seroprevalence). Moreover, in the Alpes-Maritimes district, the seroprevalence seemed to be higher in older goats (79.45% of animals 6 years old or more) than in younger animals (40.99% of one-year-olds). This result suggests frequent virus re-excretion and circulation in herds. Results analysis also shows that the seroprevalence was higher when the herd size increased. In addition, the first French CpHV-1 strain was isolated from nasal swabs taken on an infected goat. The data reported herein demonstrate that CpHV-1 circulates in mainland France, which should henceforth be taken into consideration in cases of unexplained abortion in goats.

Pestiviruses infections at the wild and domestic ruminants interface in the French Southern Alps.

In alpine pasture, interspecies transmission has recently been incriminated in the epidemiology of pestivirus infection. The aim of this study was to investigate pestivirus infections in wild and domestic ruminants sharing pastures in the French Southern Alps. Animal sera were screened for pestivirus antibodies against the pestivirus NS3 protein by a commercial blocking enzyme linked immunosorbent assay (ELISA). All 38 domestic herds tested were positive for pestivirus-specific antibodies. Individual sero-prevalence reached 76.5% (95% confidence interval [95% CI]: [74.2-78.8%]) of the 1383 sheep tested. For wild ruminants, 38.7% (95% CI: [33.8-43.9%]) of the 369 chamois tested, 28.7% (95% CI: [17.4-38.1%]) of the 72 roe deer, and 22.2% (95% CI: [6.5-37.9%]) of the 27 mouflons were seropositive. Virus screening was carried out on spleen samples from hunted wild animals (n=160) and from 15 domestic ruminants (clinically suspected to be persistently infected animals), by a conventional reverse transcription-polymerase chain reaction (RT-PCR). Three pestivirus strains were isolated from the sheep samples positive by RT-PCR. The viruses were classified in the BDV-3, BDV-Tunisian and BDV-6 genotypes. For the first time, one strain (RUPI-05 strain) was isolated from an alpine chamois and clustered in the BDV-6 genotype, showing in the 5'-UTR region 92% of identity with the ovine isolate from the same area. Thus, an active circulation of pestiviruses was demonstrated in both wild and domestic ungulates from the French Southern Alps. The results suggest that interspecies transmission between sheep and chamois probably occur.

Whole genome PCR scanning (WGPS) of Coxiella burnetii strains from ruminants.

Coxiella burnetii is the causative agent of Q fever, a zoonosis that spreads from ruminants to humans via the inhalation of aerosols contaminated by livestock's birth products. This study aimed to compare the genomes of strains isolated from ruminants by "Whole Genome PCR Scanning (WGPS)" in order to identify genomic differences. C. burnetii isolated from different ruminant hosts were compared to the Nine Mile reference strain using WGPS. The identified genomic regions of differences (RDs) were confirmed by sequencing. A set of 219 primers for amplification of 10 kbp segments covering the entire genome was obtained. The analyses revealed the presence of: i) conserved genomic regions, ii) genomic polymorphism including insertions and deletions and iii) amplification failures in some cases as well. WGPS, a descriptive approach, allowed the identification and localization of divergent genetic loci from various strains of C. burnetii which consisted of deletions, insertions and maybe genomic rearrangements. It also substantiates the role played by the IS1111 element in the genomic plasticity of C. burnetii. We believe that this approach could be combined with new sequencing technologies, as a selective/directed sequencing approach, particularly when repeated sequences are present in the analysed genomes.

Draft Genome Sequences of Six Ruminant Coxiella burnetii Isolates of European Origin.

Coxiella burnetii is responsible for Q fever, a worldwide zoonosis attributed to the inhalation of aerosols contaminated by livestock birth products. Six draft genome sequences of European C. burnetii isolates from ruminants are presented here. The availability of these genomes will help in understanding the potential host specificity and pathogenicity and in identifying pertinent markers for surveillance and tracing.