Regulation of epithelium-specific Ets-like factors ESE-1 and ESE-3 in airway epithelial cells： potential roles in airway inflammation

Airway inflammation is the hallmark of many respiratory disorders, such as asthma and cystic fibrosis. Changes in airway gene expression triggered by inflammation play a key role in the pathogenesis of these diseases. Genetic linkage studies suggest that ESE-2 and ESE-3, which encode epithelium-specific Ets-domain-containing transcription factors, are candidate asthma susceptibility genes. We report here that the expression of another member of the Ets family transcription factors ESE-1, as well as ESE-3, is upregulated by the inflammatory cytokines interleukin-1β （IL-1β） and tumor necrosis factor-α （TNF-α） in bronchial epithelial cell lines. Treatment of these cells with IL-1β and TNF-α resulted in a dramatic increase in mRNA expression for both ESE-1 and ESE-3. We demonstrate that the induced expression is mediated by activation of the transcription factor NF-κB. We have characterized the ESE-1 and ESE-3 promoters and have identified the NF-κB binding sequences that are required for the cytokine-induced expression. In addition, we also demonstrate that ESE-1 upregulates ESE-3 expression and downregulates its own induction by cytokines. Finally, we have shown that in E/f3 （homologous to human ESE-1） knockout mice, the expression of the inflammatory cytokine interleukin-6 （IL-6） is downregulated. Our findings suggest that ESE-1 and ESE-3 play an important role in airway inflammation.

Hepatitis B and C virus-induced hepatitis: Apoptosis, autophagy, and unfolded protein response

AIM: To investigate the co-incidence of apoptosis, autophagy, and unfolded protein response(UPR) in hepatitis B(HBV) and C(HCV) infected hepatocytes.METHODS: We performed immunofluorescence confocal microscopy on 10 liver biopsies from HBV and HCV patients and tissue microarrays of HBV positive liver samples. We used specific antibodies for LC3β, cleaved caspase-3, BIP(GRP78), and XBP1 to detect autophagy, apoptosis and UPR, respectively. AntiHCV NS3 and anti-HBs antibodies were also used to confirm infection. We performed triple blind counting of events to determine the co-incidence of autophagy(LC3β punctuate), apoptosis(cleaved caspase-3), and unfolded protein response(GRP78) with HBV and HCV infection in hepatocytes. All statistical analyses were performed using SPSS software for Windows(Version 16 SPSS Inc, Chicago, IL, United States). P-values < 0.05 were considered statistically significant. Statistical analyses were performed with Mann-Whitney test to compare incidence rates for autophagy, apoptosis, and UPR in HBV- and HCV-infected cells and adjacent noninfected cells.RESULTS: Our results showed that infection of hepatocytes with either HBV and HCV induces significant increase(P < 0.001) in apoptosis(cleavage of caspase-3), autophagy(LC3β punctate), and UPR(increase in GRP78 expression) in the HCV- and HBVinfected cells, as compared to non-infected cells of the same biopsy sections. Our tissue microarray immunohistochemical expression analysis of LC3β in HBV^(Neg) and HBV^(Pos) revealed that majority of HBVinfected hepatocytes display strong positive stainingfor LC3β. Interestingly, although XBP splicing in HBVinfected cells was significantly higher(P < 0.05), our analyses show a slight increase of XBP splicing was in HCV-infected cells(P > 0.05). Furthermore, our evaluation of patients with HBV and HCV infection based on stage and grade of the liver diseases revealed no correlation between these pathological findings and induction of apoptosis, autophagy, and UPR.CONCLUSION: The results of this study indicate that HCV and HBV infection activates apoptosis, autophagy and UPR, but slightly differently by each virus. Further studies are warranted to elucidate the interconnections between these pathways in relation to pathology of HCV and HBV in the liver tissue.