Evaluation of packaging capacity at the genomic 2C/3A junction region in Porcine enterovirus G.

Porcine enterovirus G (EV-G) is endogenous to most pig farming countries worldwide. Reports that a papain-like protease (PLP) gene has been naturally inserted into the 2C/3A junction region of the EV-G genome, has increased the potential public health threats from this virus. We constructed a full-length infectious cDNA clone of EV-G, CH/17GXQZ/2017, in order to determine the packaging capacity at the 2C/3A insertion site. Subsequently, recombinants viruses containing the coding tags, GFP, iLOV and His at the 2C/3A junction region, were synthesized. The infectious virus was successfully rescued only with the insertion of the His-tag, which displayed similar virological and molecular properties to its parental strain. This study determined the packaging capacity of the 2C/3A insertion site, and it provides a practical tool for studying the functions and pathogenic mechanisms of EV-G in pigs.

Biological Characteristics and Pathogenicity Analysis of a Low Virulence G2a Porcine Epidemic Diarrhea Virus.

Since the outbreak caused by a porcine epidemic diarrhea virus (PEDV) variant in 2010, the current epidemic of PEDV genotype 2 (G2) has caused huge economic losses to the pig industry in China. In order to better understand the biological characteristics and pathogenicity of the current PEDV field strains, 12 PEDV isolates were collected and plaque purified during 2017 to 2018 in Guangxi, China. The neutralizing epitopes of the spike proteins and the ORF3 proteins were analyzed to evaluate genetic variations, and they were compared with the reported G2a and G2b strains. Phylogenetic analysis of the S protein showed that the 12 isolates were clustered into the G2 subgroup (with 5 and 7 strains in G2a and G2b, respectively) and that they shared 97.4 to 99.9% amino acid identities. Among them, one of the G2a strains, CH/GXNN-1/2018, which had a titer of 106.15 PFU/mL, was selected for pathogenicity analysis. Although piglets infected with the CH/GXNN-1/2018 strain exhibited severe clinical signs and the highest level of virus shedding within 24 h postinfection (hpi), recovery and decreased virus shedding were seen after 48 hpi, and no piglets died during the whole process. Thus, the CH/GXNN-1/2018 strain had low virulence in suckling piglets. Virus neutralizing antibody analysis showed that the CH/GXNN-1/2018 strain induced cross-protection against both homologous G2a and heterologous G2b PEDV strains as early as 72 hpi. These results are of great significance for understanding PEDV in Guangxi, China, and they provide a promising naturally occurring low-virulent vaccine candidate for further study. IMPORTANCE The current epidemic of porcine epidemic diarrhea virus (PEDV) G2 has caused huge economic losses to the pig industry. Evaluation for low virulence of the PEDV strains of subgroup G2a would be useful for the future development of effective vaccines. In this study, 12 field strains of PEDV were obtained successfully, and they were characterized from Guangxi, China. The neutralizing epitopes of the spike proteins and the ORF3 proteins were analyzed to evaluate antigenic variations. One of the G2a strains, CH/GXNN-1/2018, was selected for pathogenicity analysis, and it showed that the CH/GXNN-1/2018 strain had low virulence in suckling piglets. These results provide a promising naturally occurring low-virulent vaccine candidate for further study.

USP7 Deubiquitinates and Stabilizes SIRT1.

The NAD+ -dependent protein deacetylase silent information regulator 1 (SIRT1) targets multiple proteins for deacetylation, and it has been implicated in a variety of cellular pathways and human diseases. However, it remains unclear how the abundance of SIRT1 is regulated. Here, by mass spectrometry analysis of SIRT1-containing protein complexes, we revealed that SIRT1 is physically associated with the ubiquitin-specific protease USP7. Importantly, we found that USP7 cleaves K48-linked polyubiquitin chains of SIRT1 and promotes SIRT1 stabilization. Accordingly, we demonstrated that treatment of cells with an enzymatic inhibitor of USP7 led to a decreased level of SIRT1 expression and accumulation of SIRT1 polyubiquitination. Collectively, our findings indicate that USP7 is a critical regulator of SIRT1 and provide a new pathway for the maintenance of SIRT1 abundance in cells. Anat Rec, 303:1337-1345, 2020. © 2019 American Association for Anatomy.

Hypoxia inducible factor-1α regulates autophagy via the p27-E2F1 signaling pathway.

Autophagy is a highly conserved process by which the cell contents are delivered to lysosomes for degradation, or are used to provide macromolecules for energy generation under conditions of nutritional starvation. It has previously been demonstrated that cancer cells in hypoxic regions, with an oxygen concentration below the normal physiological level, express hypoxia inducible factor (HIF)­1α, in order to adapt and survive. HIF­1α is important in the regulation of oxygen homeostasis and the transcription of hundreds of genes in response to conditions of hypoxia, hence maintaining energy and redox homeostasis. To determine if HIF­1α modulates autophagy and the underlying molecular mechanisms regulating this process, the human esophageal cancer EC109 and IMR90 human diploid fibroblast cell lines were exposed to normoxic or hypoxic conditions and the expression levels of various proteins subsequently examined. Small interfering RNA was used to silence p27, in order to investigate its role in the process of HIF­1α regulated autophagy. Hypoxia induced autophagy in IMR90 cells and it was revealed that immature IMR90 cells demonstrated an increased rate of autophagy compared with mature cells. HIF­1α promoted EC109 cell autophagy via positively modulating p27, whereas silencing of p27 abolished the autophagy induced by hypoxia. The present study identified the primary components of the p27­E2F1 signaling pathway by which HIF­1α regulates autophagy. A previously unidentified mechanism is here presented, via which cancer cells may generate energy, or obtain macromolecules for survival.

Evaluation of Moderate Alcohol Use With QT Interval and Heart Rate Using Mendelian Randomization Analysis Among Older Southern Chinese Men in the Guangzhou Biobank Cohort Study.

Western observational studies show that moderate alcohol use is associated with lower cardiovascular disease (CVD) risk, but these associations may be confounded by the healthier attributes of moderate users in these settings. Mendelian randomization analysis may help to ascertain the causal effect of moderate alcohol use on specific factors related to CVD and thereby clarify the role of alcohol. We used Mendelian randomization analysis with the aldehyde dehydrogenase 2 gene (ALDH2) as an instrumental variable to examine the association of alcohol units (10 g of ethanol) per day with heart rate-corrected QT interval and heart rate assessed from electrocardiogram among 4,588 older southern Chinese men in the Guangzhou Biobank Cohort Study (2003-2008). The F statistic was 77 for ALDH2 on alcohol use, suggesting little weak-instrument bias. Instrumental variable analysis showed that alcohol units were not associated with the corrected QT interval, with ß = 1.04 (95% confidence interval: -0.61, 2.70) milliseconds, but they were associated with increased heart rate, with ß = 0.98 (95% confidence interval: 0.04, 1.92) beat per minute. This study suggests that moderate alcohol use in men is not beneficial for heart function via QT interval or heart rate but could be detrimental. Future studies using specific cardiovascular outcomes may elucidate how alcohol affects different aspects of the cardiovascular system and, hence, the overall effects of alcohol on CVD can be estimated.

[Correlation between mitral regurgitation grading and left ventricular ejection fraction in elderly patients: a follow-up study].

OBJECTIVE: To analyze the correlation between mitral regurgitation grading and left ventricular ejection fraction in elderly patients (>60 years of age) in a 2-year follow-up. METHODS: A total of 455 patients with the diagnosis of at least mild mitral regurgitation by echocardiography were divided into ischemic mitral regurgitation (IMR) group and non-ischemic regurgitation (NIMR) group. The patients were followed up with echocardiography every 6 months and the data were analyzed at the end of 24 months. RESULTS: Mitral regurgitation grade was inversely correlated with left ventricular ejection fraction (LVEF). Patients with moderate and severe IMR had a lower LVEF than those with NIMR (P<0.05). After adjustment for age, sex, body mass index, high blood pressure, diabetes, atrial fibrillation and cardiomyopathy, the mean LVEF at 2 years was lowered by 2.7% (1.4%-4.1%), 2.7% (1.3%-4.0%), and 5.2% (3.5%-6.9%) in mild, moderate and severe IMR patients, respectively (P<0.04), and by 3.2% (1.6%-4.8%), and 3.0% (1.4%-4.5%), and 1.7%(-0.5%-3.9%) in mild, moderate and severe NIMR patients (P=0.30). CONCLUSION: The mean LVEF in IMR patients is significantly lowered compared to that in NIMR patients. The grade of mitral regurgitation is inversely correlated with the regurgitation area in IMR patients. Stratified management might help improve LVEF in severe IMR patients.

Effectiveness of 3 surgical decompression strategies for treatment of multilevel cervical myelopathy in 3 spinal centers in China: a retrospective study.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVE: To compare clinical outcomes and surgical-related adverse events in patients with multilevel cervical myelopathy (MCM) undergoing simple anterior, simple posterior, or 1-stage posterior-anterior surgical decompression strategies. SUMMARY OF BACKGROUND DATA: Simple anterior, simple posterior, and 1-stage posterior-anterior surgical decompression strategies have been advocated for MCM treatment in both Western and Chinese populations. However, there is limited evidence on whether 1-stage posterior-anterior strategy may offer equal or more advantages than the other 2 strategies for patients with MCM. METHODS: A retrospective review of medical records was conducted for 255 patients with MCM who had undergone surgical decompression in 3 Chinese spinal centers from 1999 to 2010. Neurological status, perioperative variables, and surgical complications were assessed. Multiple linear regression was used to evaluate factors associated with the outcomes of each strategy. RESULTS: Analyses were conducted on a total of 229 patients with MCM undergoing surgical decompression via 1-stage posterior-anterior (68 patients), simple anterior (102 patients), and simple posterior approaches (59 patients). One-stage posterior-anterior approach had the highest Japanese Orthopaedic Association recovery rate after adjusted for age and sex (adjusted mean ± SD: 50.0 ± 3.2, P < 0.001) and additionally adjusted for smoking, duration from onset of symptoms to surgery, comorbidities, preoperative Japanese Orthopaedic Association score, Ishihara's curvature index and Pavlov ratio, operative blood loss, operating time, anterior operated disc levels, and posterior operated levels (adjusted mean ± SD: 51.6 ± 11.6, P < 0.01). Anterior approach had the largest difference between the pre- and postoperative Ishihara's curvature indexes after adjusted for age and sex (adjusted mean ± SD: 5.3 ± 1.0, P < 0.01) and after multivariable adjustment (adjusted mean ± SD: 6.5 ± 2.8, P = 0.003). CONCLUSION: One-stage posterior-anterior strategy can be a reliable and effective treatment strategy for MCM in a subgroup of patients with anterior and posterior compression on spinal cord simultaneously.

MicroRNA-10a targets CHL1 and promotes cell growth, migration and invasion in human cervical cancer cells.

MicroRNAs (miRNAs) play an important role in cancer initiation, progression and metastasis by regulating their target genes. Here, we found microRNA-10a (miR-10a) is upregulated in human cervical cancer and promotes the colony formation activity, migration and invasion of HeLa and C33A cells. Subsequently, CHL1 is confirmed as a target of miR-10a and is negatively regulated by miR-10a at mRNA and protein levels. Furthermore, knockdown of CHL1 expression results in increased colony formation activity, migration and invasion. Finally, overexpression of CHL1 lacked the 3'UTR abolished the effects of miR-10a. Our results may provide a strategy for blocking tumor metastasis.