A single amino acid substitution in the AAA-type ATPase LRD6-6 activates immune responses but decreases grain quality in rice.

Plant spotted leaf (spl) mutants are useful to reveal the regulatory mechanisms of immune responses. Thus, in crop plants, their agronomic traits, especially the grain quality are usually ignored. Here, we characterized a rice spl mutant named spl-A (spotted leaf mutant from A814) that shows autoimmunity, broad-spectrum disease resistance and growth deterioration including decreased rice quality. A single nucleotide mutation of C1144T, which leads to change of the 382nd proline to serine, in the gene encoding the ATPases associated with diverse cellular activities (AAA)-type ATPase LRD6-6 is responsible for the phenotype of the spl-A mutant. Mechanistically, this mutation impairs LRD6-6 ATPase activity and disrupts its interaction with endosomal sorting complex required for transport (ESCRT)-III subunits OsSNF7.1/7.2/7.3. And thus, leading to compromise of multivesicular bodies (MVBs)-mediated vesicle trafficking and accumulation of ubiquitinated proteins in both leaves and seeds of spl-A. Therefore, the immune response of spl-A is activated, and the growth and grain quality are deteriorated. Our study identifies a new amino acid residue that important for LRD6-6 and provides new insight into our understanding of how MVBs-mediated vesicle trafficking regulates plant immunity and growth, including grain quality in rice.

Inhibition of hepatitis E virus replication by zinc-finger antiviral Protein synergizes with IFN-ß.

Hepatitis E virus (HEV) infection is the most common cause of acute viral hepatitis worldwide. However, host-HEV interactions have yet to be fully understood. Zinc-finger antiviral protein (ZAP) is a novel interferon (IFN)-stimulated gene product that inhibits a variety of viruses in synergy with IFN-ß. To evaluate the role of ZAP in HEV infection, its expressions in HEV-infected patients and in cell cultures were measured. We report a significant inhibition of ZAP expression in patients with HEV genotype four acute infection. The expression of ZAP in the HEV life cycle was monitored in cultures of HEV-infected cells. Results indicated that the ZAP level decreased significantly after HEV infection. ZAP over-expression inhibited HEV replication, whereas its knockdown by RNA interference significantly increased HEV RNA. These suggest that ZAP serves as an antiviral in HEV infection. Moreover, silencing ZAP decreased IFN regulatory factor 3 (IRF3) phosphorylation in HEV-infected cells treated with poly(I:C), indicating that ZAP synergizes with IFN-ß. In conclusion, ZAP is an important anti-HEV host factor and in synergy with IFN-ß, inhibits HEV replication.

Relation between blood glucose and the prognosis of severe coronavirus disease 2019. / 血糖与重型2019å† çŠ¶ç— æ¯’ç— é¢„åŽçš„å ³ç³».

OBJECTIVES: To describe the clinical characteristics and outcomes of severely ill patients with coronavirus disease 2019, and to investigate the relationship between plasma glucose level and the prognosis of severely ill patients with coronavirus disease 2019. METHODS: We enrolled 52 severely ill patients with coronavirus disease 2019. Among them, 12 cases progressed to critical illness. The clinical and biochemical characteristics of severely and critically ill patients were compared. RESULTS: Compared with the severely ill patients, critically ill patients had higher white blood cell and neutrophil counts, as well as higher levels of D-dimer, IL-6 and C-reactive protein (all P<0.05). Before treatment, the fasting plasma glucose (FPG) levels were significantly higher in the critically ill patient's group [(10.23±3.71) mmol/L] compared to those in the severely ill patients [(7.12±3.35) mmol/L, P<0.05]. After adjusting for age, gender, and course of the disease, fasting blood glucose at admission (OR=1.308, 95% CI 1.066 to 1.606, P=0.01) and hyperglycemia at admission (OR=29.198, 95% CI 2.903 to 293.639, P=0.004) were closely related to whether severely ill patients progressed to critical patients with coronavirus disease 2019. In our study, 15 (34.8%) of the severely ill and 10 (83.3%) critically ill patients received the steroid treatment. Compared with the severely ill patients, the FPG levels in critically ill patients were higher (P<0.05). CONCLUSIONS: Fasting hyperglycemia at admission is a significant predictor for the prognosis of severely ill patients with coronavirus disease 2019. Closely monitoring and the optimal management of hyperglycemia may improve the prognosis of patients with coronavirus disease 2019.

BALB/c Mouse Is a Potential Animal Model System for Studying Acute and Chronic Genotype 4 Hepatitis E Virus Infection.

Hepatitis E virus (HEV) is the main pathogen of hepatitis worldwide. However, its infection biology and pathogenesis remain largely unknown. Suitable small-animal models are required to advance the study of HEV infection. Although an efficient model of genotype 1 (gt1) and gt3 HEV infection has been established in human liver chimeric mice, the infectivity of gt4 HEV infection in mice has not been comprehensively characterized. In this study, immunocompromised BALB/c nude, immunocompetent BALB/c, and C57BL/6 mice were inoculated with either gt3 or gt4 HEV (19 HEV strains, including human, swine, macaque-adapted, and cow HEV strains). Infectivity was identified by viral RNA and antigen detection, inflammation, and histopathological analysis. Then, HEV-infected BALB/c mice were treated with antiviral drugs. Acute HEV infection was established in BALB/c mice inoculated with eight gt4 HEV strains. However, gt3 HEV strains failed to achieve active HEV infection. HEV infection was established in BALB/c nude and regular mice inoculated with gt4 HEV but not in C57BL/6 mice. Gt4 HEV infection resulted in rapid viremia and high titers in feces, sera, and replication sites. HEV infection in mice showed no gender preference. Furthermore, chronic gt4 HEV infection was well imitated in BALB/c mice for 32 weeks and caused liver fibrosis. CONCLUSION: BALB/c mice have a great potential for reproducing the process of gt4 HEV infection. The successful establishment of a gt4 HEV small-animal model provides an opportunity to further understand HEV infection biology and zoonotic transmission and develop anti-HEV vaccine.

Hepatitis E viral infection causes testicular damage in mice.

Hepatitis E virus (HEV) is the main pathogen of hepatitis E infections with multiple extrahepatic replication sites. The presence of HEV RNA in the semen of infertile males suggests HEV replicates in the male genital tract. However, the mechanism is largely remained elusive. A BALB/c-based animal model was used to evaluate the effects of HEV infection on the testicular damage. HEV RNA was detected in feces, blood and livers from 7 to 28 days post-inoculation (dpi), while was positive in male genital tract from 7 to 70 dpi. Positive signals of HEV antigens were observed in testes, epididymides and seminal vesicles (SVs). Impaired sperm quality, destroyed the blood-testis barrier (BTB) and drastically decreased spermatogonia suggested that HEV infection causes testicular damage. Antiviral immune response was barely found in the testes. Results demonstrated that HEV replicates in male genital tract, causes testicular damage, and consequently results in flawed fertility.

Successful Establishment of Hepatitis E Virus Infection in Pregnant BALB/c Mice.

Worldwide, the Hepatitis E virus (HEV) is the main pathogen of acute viral hepatitis, with an extremely high mortality in pregnant women. However, the pathogenesis of HEV infection in pregnant women remains largely unknown. We established an HEV-infected pregnant mice animal model to explore the adverse pregnancy outcomes of HEV infection. Mice were infected with HEV in their early, middle and late stages of pregnancy. HEV RNA was detected in the tissues (liver, spleen, kidney, colon, uterus and placenta) of pregnant mice. HEV antigens were also detected in these tissues of HEV-infected pregnant mice. Miscarriages (7/8, 87.5%) occurred in pregnant mice infected with HEV in the middle of pregnancy. Th1-biased immune status was found in these aborted mice. Vertical transmission was confirmed by HEV replication in the uterus and placenta, as well as in the positive HEV RNA and HEV antigen positive in fetal livers. The successful establishment of HEV infection in pregnant mice is beneficial for further study of HEV pathogenesis, especially the adverse pregnancy outcomes caused by HEV infection.

High prevalence of hepatitis E virus infection in goats.

Hepatitis E virus (HEV) is a major cause of acute hepatitis worldwide, primarily transmitted by fecal-oral route. Zoonotic transmission of HEV from HEV-infected pigs (pork) or cows (milk) to human or non-human primate has been confirmed, but the risk of HEV in goat is still rarely assessed. In the present study, stool, blood, tissues, and milk of goat were collected for HEV infection investigation from Dali City of Yunnan Province in China, where raw mutton and goat milk are traditionally consumed. Surprisingly, a high prevalence of HEV infection in goat was found. Phylogenetic analysis revealed that all HEV isolates from goat belong to genotype 4 and subtype 4h, and shared a high similarity homology (>99.6%) with HEV isolated from human, swine, and cows in the same area. Results suggested that goats are a previously unrecognized HEV host.

Excretion of infectious hepatitis E virus into milk in cows imposes high risks of zoonosis.

UNLABELLED: Hepatitis E virus (HEV) represents the main cause of acute hepatitis worldwide. HEV infection in immunocompromised patients involves a high risk for the development of chronic hepatitis. Because HEV is recognized as a zoonotic pathogen, it is currently believed that swine is the primary reservoir. However, this is not sufficient to justify the strikingly high seroprevalence of HEV in both developing and Western countries. Thus, this study aimed to identify new zoonotic sources that bear a high risk of transmission to humans. We collected fecal, blood, and milk samples of cows in a typical rural region of Yunnan Province in southwest China, where mixed farming of domestic animals is a common practice. HEV RNA was quantified by quantitative real-time polymerase chain reaction, and the whole genome was sequenced. HEV infectivity was assessed in rhesus macaques. We found a high prevalence of active HEV infection in cows as determined by viral RNA positivity in fecal samples. Surprisingly, we discovered that HEV is excreted into milk that is produced by infected cows. Phylogenetic analysis revealed that all HEV isolates from cow/milk belong to genotype 4 and subtype 4h. Gavage with HEV-contaminated raw and even pasteurized milk resulted in active infection in rhesus macaques. Importantly, a short period of boiling, but not pasteurization, could completely inactivate HEV. CONCLUSION: Infectious HEV-contaminated cow milk is recognized as a new zoonotic source that bears a high risk of transmission to humans; these results call attention to understanding and establishing proper measurement and control of HEV zoonotic transmission, particularly in the setting of mixed farming of domestic animals. (Hepatology 2016;64:350-359).

Characterization of hepatitis E virus infection in tree shrew (Tupaia belangeri chinensis).

BACKGROUND: Hepatitis E virus (HEV) is a major cause of hepatitis in developing countries and poses a threat to public health worldwide. Tree shrew (Tupaia belangeri chinensis) is a useful animal model in studies on hepatitis viruses, such as hepatitis B and C viruses. However, the use of this animal model for HEV research is yet to be developed. METHODS: Tree shrews were intravenously (IV) injected with swine genotype 4 HEV or infected by contact-exposure to IV infected tree shrews. RT-nPCR was performed to detect HEV RNA in the feces, tissues, and blood. HEV capsid protein in the different tissues was detected by Western blot and estimated by quantitative RT-PCR. Anti-HEV antibodies were determined by ELISA. Liver damages were evaluated by histopathologic examination and analysis of liver-specific enzymes activities. RESULTS: Both negative and positive strands of HEV RNA were detected in the feces of the HEV-infected or contact-exposed tree shrews 3-4 days post-inoculation. HEV RNA was detectable in the liver, spleen, kidneys, and bile. Virusemia developed in all the HEV-infected tree shrews. HEV capsid protein was expressed in the liver, spleen, and kidneys. The histological examination and analysis of liver-specific enzymes activities showed that HEV caused acute liver lesions in the tree shrews. Meanwhile, the infected tree shrews showed positive IgG and IgM antibodies. CONCLUSIONS: Tree shrews are susceptible to HEV and may be useful animal models for HEV experimental infection studies on pathogenesis or preclinical drug development.

Hepatitis E virus infection activates signal regulator protein α to down-regulate type I interferon.

Hepatitis E virus (HEV) is a major cause of enterically transmitted acute hepatitis worldwide. However, the mechanism of HEV replication is unclear. Type I interferon is the first defense line of host against viral infection. Signal regulator protein α (SIRP-α) plays an important role in negative regulation of innate immunity. In the present study, HEV infection significantly activated the expression of SIRP-α and down-regulated phosphorylation of IRF3, consequently resulted in suppression of type I interferon (IFN-ß). In conclusion, HEV exploited SIRP-α to negative regulated IFN-ß of the host innate immune system to promote viral infection. It suggested that interfering with the functions of SIRP-α should be considered as a potential therapeutic approach to the prevention and treatment of HEV infection.

[Construction of Recombinant Full-length Hepatitis E Virus Fused with EGFP and Assessment of Infectivity].

The purpose of this study was to construct recombinant full-length hepatitis E virus(HEV)fused with enhanced green fluorescent protein(EGFP),and assess its infectivity in A549 cells. Two fragments from the full-length HEV genome and the EGFP gene were amplified by PCR. The EGFP gene was inserted downstream of the HEV ORF2 and then cloned into the pGEM® -7Zf(+)vector containing the T7 and SP6RNA polymerase promoters, producing pGEM-HEV-EGFP. The construction of the pGEM-HEV-EGFP recombinant plasmid was confirmed by restriction enzyme digest and sequencing. The pGEM-HEV-EGFP recombinant plasmid was transfected into A549 cells to assess infectivity using Lipofectamine. EGFP expression was observed at 24hpost-transfection,and expression of the HEV ORF2 was detected by immunofluorescence, confirming the presence of the HEV ORF2 and EGFP fusion protein. Cytopathic effects were observed at day seven post-transfection. The infectivity of pGEM-HEV-EGFP was confirmed by the presence of fluorescence after three continuous passages. The recombinant pGEM-HEV-EGFP vector was successfully constructed and effectively infected A549 cells, which will facilitate future studies on the mechanisms of HEV infection and pathogenesis.

Effect of group counseling on depression, compliance and blood sugar level in diabetic patients.

OBJECTIVE: To establish an interference mode of group counseling for diabetic patients with depression and to evaluate the effectiveness of this mode on depression, treatment compliance and blood sugar level in the patients.
 METHODS: One hundred diabetic patients with depression were randomly divided into a counseling group and a control group (n=50 per group). Self-Rating Depression Scale (SDS) was applied to all the patients. The interference mode of group counseling was established through literature review, expert consultation or interview. The counseling group received counseling for 8 times within 2 months.
 RESULTS: There was a significant difference in the SDS scores at 0, 3, 6 or 12 months after the intervention between the 2 groups (P<0.001). For the counseling group, there was a significant difference in the SDS scores between pre-intervention and 3, 6 or 12 months after intervention (P<0.001). However, there was no significant difference in the SDS scores between any two time points after the intervention (P>0.05). There was a significant difference in the compliance between any two time points after the intervention (P<0.05). Fasting blood glucose (FBG), 2 h postprandial blood glucose (2hPG) or glycosylated hemoglobin (HbA1c) was significantly different at any two time points after the intervention (P<0.05).
 CONCLUSION: Group counseling can improve depression, compliance and blood sugar control in the diabetic patients.