Transcriptome analysis revealed gene expression feminization of testis after exogenous tetrodotoxin administration in pufferfish Takifugu flavidus.

Tetrodotoxin (TTX) is a deadly neurotoxin and usually accumulates in large amounts in the ovaries but is non-toxic or low toxic in the testis of pufferfish. The molecular mechanism underlying sexual dimorphism accumulation of TTX in ovary and testis, and the relationship between TTX accumulation with sex related genes expression remain largely unknown. The present study investigated the effects of exogenous TTX treatment on Takifugu flavidus. The results demonstrated that exogenous TTX administration significantly incresed level of TTX concentration in kidney, cholecyst, skin, liver, heart, muscle, ovary and testis of the treatment group (TG) than that of the control group (CG). Transcriptome sequencing and analysis were performed to study differential expression profiles of mRNA and piRNA after TTX administration of the ovary and testis. The results showed that compared with female control group (FCG) and male control group (MCG), TTX administration resulted in 80 and 23 piRNAs, 126 and 223 genes up and down regulated expression in female TTX-treated group (FTG), meanwhile, 286 and 223 piRNAs, 2 and 443 genes up and down regulated expression in male TTX-treated group (MTG). The female dominant genes cyp19a1, gdf9 and foxl2 were found to be up-regulated in MTG. The cyp19a1, whose corresponding target piRNA uniq_554482 was identified as down-regulated in the MTG, indicating the gene expression feminization in testis after exogenous TTX administration. The KEGG enrichment analysis revealed that differentially expressed genes (DEGs) and piRNAs (DEpiRNAs) in MTG vs MCG group were more enriched in metabolism pathways, indicating that the testis produced more metabolic pathways in response to exogenous TTX, which might be a reason for the sexual dimorphism of TTX distribution in gonads. In addition, TdT-mediated dUTP-biotin nick end labeling staining showed that significant apoptosis was detected in the MTG testis, and the role of the cell apoptotic pathways was further confirmed. Overall, our research revealed that the response of the ovary and testis to TTX administration was largely different, the ovary is more tolerant whereas the testis is more sensitive to TTX. These data will deepen our understanding on the accumulation of TTX sexual dimorphism in Takifugu.

Association between PNPLA3 rs738409 polymorphisms and risk of hepatocellular carcinoma and its development in patients with cirrhosis: a meta-analysis.

Genetic variants of PNPLA3 have been implicated in hepatocellular carcinoma (HCC) susceptibility; however, published findings have been both conflicting and inconclusive. To obtain a more precise estimate of the association of the PNPLA3 rs738409 (C > G) polymorphism with the overall risk of HCC and in patients with cirrhosis, we performed a meta-analysis of nine eligible studies identified through an online search of Ovid, PubMed, EBSCO, the Cochrane Library, the Web of Science, the China National Knowledge Infrastructure, Wanfang, and Chinese Biomedicine databases. The studies comprised 1175 patients with HCC, 876 with cirrhosis, and 3026 healthy controls. Pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were calculated to assess associations, using fixed-effects models. Etiology subgroup and sensitivity analyses were also performed. Our results showed that rs738409 was associated with overall HCC risk and in patients with cirrhosis in the genetic contrast modes: G vs. C, GG + CG vs. CC, GG vs. CG + GG, and GG vs. CC. Stratification by etiology did not reveal any significant association between this polymorphism and hepatitis C virus (HCV)-related HCC in patients with HCV-related cirrhosis (P > 0.05). However, healthy individuals harboring two copies of the rs738409 G variant had a higher risk of HCC (GG vs. CC: OR = 4.40, 95% CI: 3.28-5.91) than those carrying a single G allele (CG vs. CC: OR = 1.62, 95% CI: 1.34-1.59); these significant association were also present in each subgroup. Furthermore, the association was more pronounced in alcohol vs. HCV-related HCC. The present meta-analysis suggests that the PNPLA3 rs738409 G allele is a risk factor for HCC except in patients with HCV-related cirrhosis, and that two copies of the rs738409 G variant conferred a higher risk for HCC in controls, especially for alcohol-related HCC. Further studies with a larger sample size are needed to ascertain the association in different ethnicities.

Associations between Cox-2 rs20417 and rs5275 polymorphisms and the risk of hepatocellular carcinoma: a meta analysis.

Genetic polymorphisms of cyclooxygenase-2 (Cox-2) gene have been implicated in the susceptibility to hepatocellular carcinoma (HCC), but the findings from published studies are conflicting and inconclusive. To obtain a more precise estimate of the association of Cox-2 polymorphisms with HCC risk, we performed a meta-analysis of eight eligible case-control studies identified through an extensive online database search of PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wanfang and Chinese Biomedicine Database; after exclusion, 2324 cases and 2604 controls were included. The pooled odds ratios with corresponding 95% confidence intervals were calculated to assess associations, using fixed- or random-effect models. In addition, subgroup analysis by ethnicity and sensitivity analysis were performed. Our results showed that the Cox-2 rs20417 (-765 G/C) polymorphism was not associated with HCC risk in the studied genetic contrast modes (C vs. G, GC vs. GG, and CC + GC vs. GG). No significant association was found with ethnic groups examined (P > 0.05). Similarly, no significant association of the Cox-2 rs5275 (+ 8473 T/C) polymorphism and HCC risk was found under any of the studied contrasts (C vs. T, TC vs. TT, CC vs. TT, CC + TC vs. TT, CC vs. TC + TT). The present meta-analysis, combining all currently available data, suggests no significant associations of either Cox-2 polymorphism with HCC risk. Further studies with a larger sample size are needed to determine the association in different ethnicities.