Identification of coronaviruses in farmed wild animals reveals their evolutionary origins in Guangdong, southern China.

Coronavirus infections cause diseases that range from mild to severe in mammals and birds. In this study, we detected coronavirus infections in 748 farmed wild animals of 23 species in Guangdong, southern China, by RT-PCR and metagenomic analysis. We identified four coronaviruses in these wild animals and analysed their evolutionary origins. Coronaviruses detected in Rhizomys sinensis were genetically grouped into canine and rodent coronaviruses, which were likely recombinants of canine and rodent coronaviruses. The coronavirus found in Phasianus colchicus was a recombinant pheasant coronavirus of turkey coronavirus and infectious bronchitis virus. The coronavirus in Paguma larvata had a high nucleotide identity (94.6-98.5 per cent) with a coronavirus of bottlenose dolphin (Tursiops truncates). These findings suggested that the wildlife coronaviruses may have experienced homologous recombination and/or crossed the species barrier, likely resulting in the emergence of new coronaviruses. It is necessary to reduce human-animal interactions by prohibiting the eating and raising of wild animals, which may contribute to preventing the emergence of the next coronavirus pandemic.

Expressions of inducible nitric oxide synthase and matrix metalloproteinase-9 and their effects on angiogenesis and progression of hepatocellular carcinoma.

AIM: To determine the expressions of inducible nitric oxide synthase (iNOS) and matrix metalloproteinase-9 (MMP-9) in hepatocellular carcinoma (HCC) and to investigate the relationship between iNOS and MMP-9 expression and their effects on angiogenesis and progression of HCC. METHODS: In this study, we examined iNOS, MMP-9, and CD34 expression in specimens surgically removed from 32 HCC patients and 7 normal liver tissues by immunohistochemical staining. Meanwhile, microvessel density (MVD) was determined as a marker of angiogenesis by counting CD34-positive cells. RESULTS: The positive rates of iNOS and MMP-9 expression were 71.88% (23/32) and 78.13% (25/32) in HCC. MMP-9 expression was significantly correlated with tumor size, capsule status, TNM stage, and risk of HCC recurrence (P = 0.032, P = 0.033, P = 0.007, and P = 0.001, respectively). There was also a significant relationship between iNOS expression and capsule status and risk of HCC recurrence (P = 0.049 and P = 0.004, respectively), but no correlation between iNOS expression and tumor size and TNM stage. There was a positive association between MVD and TNM stage and risk of HCC recurrence (P = 0.037 and P = 0.000, respectively). The count of MVD was significantly different in different iNOS and MMP-9 immunoreactivity groups (F = 17.713 and 17.097, P = 0.000 and P = 0.000, respectively). The examination of Spearman's rank correlation coefficient showed that there was a significant positive correlation between MVD and iNOS, MMP-9 immunoreactivity (r = 0.754 and 0.751, P = 0.000 and P=0.000, respectively). There was also a significant association between MMP-9 and iNOS expression in HCC (P = 0.010). CONCLUSION: Nitric oxide (NO) produced by iNOS could modulate MMP-9 production and therefore contribute to tumor cell angiogenesis and invasion and metastasis in HCC. The strong expression of iNOS and MMP-9 in HCC may be helpful in evaluating the recurrence of HCC, predicting poor prognosis. For patients with strong expression of MMP-9 and iNOS, the optimal treatment scheme needs to be selected.