Sf-PHB2, a new transcription factor, drives WSSV Ie1 gene expression via a 12-bp DNA element

CgPHB2 involved in the haemocyte mitophagy in response to Vibrio splendidus stimulation in Pacific oyster Crassostrea gigas

Prohibitin2 (PHB2) is recently identified as a novel inner membrane mitophagy receptor to mediate mitophagy. In the present study, the function of CgPHB2 in mediating mitophagy in response to Vibrio splendidus stimulation was investigated in Crassostrea gigas. CgPHB2 protein was mainly distributed in the cytoplasm of three subpopulations of haemocytes. After V. splendidus stimulation, the expressions of CgPHB2 mRNA in haemocytes were up-regulated significantly at 6, 12 and 24 h, and the abundance of CgPHB2 protein was also enhanced at 12-24 h compared to control group. Furthermore, the green signals of CgPHB2 were colocalized respectively with the red signals of mitochondria and CgLC3 in the haemocytes at 12 h after V. splendidus stimulation, and the co-localization value of CgPHB2 and mtphagy Dye was significantly increased. The direct interaction between CgPHB2 and CgLC3 was simulated by molecular docking. In PHB2-inhibitor Fluorizoline-treated oysters, the mRNA expressions of mitophagy-related genes and the ratio of mitophagy were significantly decreased in haemocytes of oysters after V. splendidus stimulation. All the results collectively suggested that CgPHB2 participated in mediating the haemocyte mitophagy in the antibacterial immune response of oysters.

Prohibitins: A Key Link between Mitochondria and Nervous System Diseases

Prohibitins (PHBs) are conserved proteins in eukaryotic cells, which are mainly located in the inner mitochondrial membrane (IMM), cell nucleus, and cell membrane. PHBs play crucial roles in various cellular functions, including the cell cycle regulation, tumor suppression, immunoglobulin M receptor binding, and aging. In addition, recent in vitro and in vivo studies have revealed that PHBs are important in nervous system diseases. PHBs can prevent apoptosis, inflammation, mitochondrial dysfunction, and autophagy in neurological disorders through different molecules and pathways, such as OPA-1, PINK1/Parkin, IL6/STAT3, Tau, NO, LC3, and TDP43. Therefore, PHBs show great promise in the protection of neurological disorders. This review summarizes the relevant studies on the relationship between PHBs and neurological disorders and provides an update on the molecular mechanisms of PHBs in nervous system diseases.

LvYY1 Activates WSSV ie1 Promoter for Enhanced Vaccine Production and Efficacy

The baculovirus expression vector system (BEVS) has been used as a preferred platform for the production of recombinant protein complexes and efficacious vaccines. However, limited protein yield hinders the application of BEVS. It is well accepted that transcription enhancers are capable of increasing translational efficiency of mRNAs, thereby achieving better protein production. In this study, the ability of LvYY1 as a transcription enhancer was assessed. LvYY1 could interact with the WSSV ie1 promoter via binding to special DNA sites in BEVS. The effects of LvYY1 on protein expression mediated by WSSV ie1 promoter of BEVS was investigated using eGFP as a reporter gene. Enhanced eGFP expression was observed in Sf-9 cells with LvYY1. On this basis, a modified vector combining ie1 promoter and LvYY1 was developed to express either secreting CSFV E2 or baculovirus surface displayed H5 HA of AIVs. Compared to control groups without LvYY1, E2 protein yield increases to 1.6-fold, while H5 production improves as revealed by an upregulated hemagglutination titer of 8-fold at least. Moreover, with LvYY1, H5 displaying baculovirus driven by WSSV ie1 promoter (BV-LvYY1-ie1-HA) sustains the transduction activity in CEF cells. In chicken, BV-LvYY1-ie1-HA elicits a robust immune response against H5 AIVs in the absence of adjuvant, as indicated by specific antibody and cytokine responses. The findings suggest its potential function as both a vectored and subunit vaccine. These results demonstrate that the coexpression with LvYY1 serves as a promising strategy to extensively improve the efficiency of BEVS for efficacious vaccine production.

Molecular Mechanisms of White Spot Syndrome Virus Infection and Perspectives on Treatments

Since its emergence in the 1990s, White Spot Disease (WSD) has had major economic and societal impact in the crustacean aquaculture sector. Over the years shrimp farming alone has experienced billion dollar losses through WSD. The disease is caused by the White Spot Syndrome Virus (WSSV), a large dsDNA virus and the only member of the Nimaviridae family. Susceptibility to WSSV in a wide range of crustacean hosts makes it a major risk factor in the translocation of live animals and in commodity products. Currently there are no effective treatments for this disease. Understanding the molecular basis of disease processes has contributed significantly to the treatment of many human and animal pathogens, and with a similar aim considerable efforts have been directed towards understanding host-pathogen molecular interactions for WSD. Work on the molecular mechanisms of pathogenesis in aquatic crustaceans has been restricted by a lack of sequenced and annotated genomes for host species. Nevertheless, some of the key host-pathogen interactions have been established: between viral envelope proteins and host cell receptors at initiation of infection, involvement of various immune system pathways in response to WSSV, and the roles of various host and virus miRNAs in mitigation or progression of disease. Despite these advances, many fundamental knowledge gaps remain; for example, the roles of the majority of WSSV proteins are still unknown. In this review we assess current knowledge of how WSSV infects and replicates in its host, and critique strategies for WSD treatment.

The promoter of the white spot syndrome virus immediate-early gene WSSV108 is activated by the cellular KLF transcription factor

A series of deletion and mutation assays of the white spot syndrome virus (WSSV) immediate-early gene WSSV108 promoter showed that a Krüppel-like factor (KLF) binding site located from -504 to -495 (relative to the transcription start site) is important for the overall level of WSSV108 promoter activity. Electrophoretic mobility shift assays further showed that overexpressed recombinant Penaeus monodon KLF (rPmKLF) formed a specific protein-DNA complex with the (32)P-labeled KLF binding site of the WSSV108 promoter, and that higher levels of Litopenaeus vannamei KLF (LvKLF) were expressed in WSSV-infected shrimp. A transactivation assay indicated that the WSSV108 promoter was strongly activated by rPmKLF in a dose-dependent manner. Lastly, we found that specific silencing of LvKLF expression in vivo by dsRNA injection dramatically reduced both WSSV108 expression and WSSV replication. We conclude that shrimp KLF is important for WSSV genome replication and gene expression, and that it binds to the WSSV108 promoter to enhance the expression of this immediate-early gene.

Association study of sepiapterin reductase gene promoter polymorphisms with schizophrenia in a Han Chinese population

Sepiapterin reductase participates in the biosynthesis of tetrahydrobiopterin, which plays very important roles in the pathogenesis of schizophrenia via dysregulation of neurotransmitter systems. Here, two single nucleotide polymorphisms (rs1876487 and rs2421095) in the promoter region of SPR were genotyped in 941 schizophrenic patients and 944 controls in a Han Chinese population using the SNaPshot technique. No significant differences were found in the distribution of alleles or genotypes of the two single nucleotide polymorphisms (SNPs) between schizophrenic patients and controls (all P>0.05). Likewise, no haplotype was found to be associated with schizophrenia. However, sex-stratified analysis revealed that the frequencies of the A allele of rs1876487 and the A-A (rs2421095-rs1876487) haplotype were all significantly different between schizophrenia and controls in females (P=0.040 and P=0.033, respectively), but not in males. Additionally, luciferase reporter gene assays revealed that the A-A haplotype had significantly higher SPR transcriptional activity compared with the A-C haplotype in SH-SY5Y cells. Our data indicate that the two SNPs do not influence the risk of schizophrenia when using the total sample, but the A allele of rs1876487 and the A-A haplotype may contribute to protective roles for schizophrenia in females.