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As an intracellular pattern recognition receptor (PRR), laboratory of genetics and physiology 2 (LGP2) plays a pivotal role in detecting nucleic acids of invading pathogens and simultaneously modulating signaling by retinoic acid-inducible gene-I (RIG-I) and melanoma differentiation-associated gene 5 (MDA5) in type I interferon (IFN–I) pathway. Nevertheless, the underlying antiviral transcription mechanism of LGP2 remains obscure. The present study attempted to reveal the methylation levels of CiLGP2 ( Ctenopharyngodon idella LGP2 ) in muscle and spleen of grass carp and their association with the resistance against grass carp reovirus (GCRV). By prediction, the CpG island was 133 bp in length in 5′-flanking region, containing six candidate CpG loci, whose methylation statuses were investigated by virtue of the bisulfite sequencing PCR (BSP) among muscle and spleen tissues in 120 individuals that were divided into resistant/susceptible groups after a challenge experiment, and the association analysis was performed with Chi-square test. Quantitative real-time RT-PCR (qRT-PCR) was employed to ascertain the interrelation between methylation status and transcription of CiLGP2 . The CpG sites at −1394, −1366, −1331 and −1314 nt were identified as hypermethylated, inversely unmethylated at −1350 CpG site. The −1411 CpG site presented six methylation patterns as well as one mentionable type of mutation triggered by spontaneous deamination. Although there was no statistically significant difference on DNA methylation with resistance against GCRV at −1411 CpG site, the methylation levels were significantly lower in spleen than those in muscle, accompanied by higher mRNA expression of CiLGP2 in spleen. Notably, DNA methylation may be conceivably serve as an essential regulatory factor for CiLGP2 antiviral transcription in spleen. This research first demonstrated the relationship between DNA methylation and LGP2 gene expression, preliminary revealed the underlying transcription mechanism of CiLGP2 against GCRV as well as provided potential references and laid a theoretical foundation for viral recognition and regulation research of LGP2 in vertebrates. [ABSTRACT FROM AUTHOR]

Accumulating evidence suggests that vitamin D (VD) has a therapeutic effect on non-alcoholic fatty liver disease (NAFLD). Pyroptosis and gut microbiota have been recognized as critical factors of the progression of NAFLD. However, the effect of VD on the pyroptosis and gut microbiota in NAFLD remains inconclusive. Herein, rats were fed high fat diet (HFD) for 12 weeks and concurrently treated with 5 μ g/kg 1,25(OH) 2 D 3 twice a week. BRL-3A cells were stimulated with 0.4 mmol/L palmitic acid (PA) and 1 μ g/ml lipopolysaccharide (LPS) for 16 h and treated with 10−6 mol/L 1,25(OH) 2 D 3. Effect of VD on the hepatic injury, lipid accumulation, activation of NLRP3 inflammasome and pyroptosis was determined in vivo and in vitro. Next, gasdermin D N -terminal (GSDMD-N) fragment was overexpressed in BRL-3A cells to investigate the role of pyroptosis in the therapeutic effect of VD on NAFLD. In addition, gut microbiota in NAFLD rats was also analyzed. Results showed that VD attenuated HFD-induced hepatic injury in vivo and PA-LPS-induced impairment of cell viability in vitro , and inhibited lipid accumulation, activation of NLRP3 inflammasome and pyroptosis in vivo and in vitro. GSDMD-N fragment overexpression suppressed the protective effect of VD on PA-LPS-induced activation of NLRP3 inflammasome, impairment of cell viability and lipid accumulation, indicating that VD might attenuate NAFLD through inhibiting pyroptosis. Additionally, VD also restored HFD-induced gut microbiota dysbiosis by increasing the relative abundance of Lactobacillus and reducing that of Acetatifactor , Oscillibacter and Flavonifractor. This study provides a novel mechanism underlying VD therapy against NAFLD. • Vitamin D inhibited activation of NLRP3 inflammasome and pyroptosis in NAFLD rat. • Vitamin D might attenuate HFD-induced NAFLD by inhibiting pyroptosis in NAFLD rat. • Vitamin D restored HFD-induced gut microbiota dysbiosis in NAFLD rat. [ABSTRACT FROM AUTHOR]

Toll-like receptor 8 (TLR8), a prototypical intracellular member of TLR family, is generally linked closely to antiviral innate immune through recognizing viral nucleic acid. In this study, 5′-flanking region of Ctenopharyngodon idella TLR8 ( CiTLR8 ), 671 bp in length, was amplified and eight SNPs containing one SNP in the intron, three SNPs in the coding region (CDS) and four SNPs in the 3′-untranslated region (UTR) were identified and characterized. Of which 4062 A/T was significantly associated with the susceptibility/resistance to GCRV both in genotype and allele ( P < 0.05), while 4168 C/T was extremely significantly associated with that ( P < 0.01) according to the case (susceptibility)–control (resistance) analysis. Following the verification experiment, further analyses of mRNA expression, linkage disequilibrium (LD), haplotype and microRNA (miRNA) target site indicated that 4062 A/T and 4168 C/T in 3′-UTR might affect the miRNA regulation, while the exertion of antiviral effects of 4062 A/T might rely on its interaction with other SNPs. Additionally, the high-density of SNPs in 3′-UTR might reflect the specific biological functions of 3′-UTR. And also, the mutation of 747 A/G in intron changing the potential transcriptional factor-binding sites (TFBS) nearby might affect the expression of CiTLR8 transcriptionally or post-transcriptionally. Moreover, as predicted, the A/G transition of the only non-synonymous SNP (3846 A/G) in CDS causing threonine/alanine variation, could shorten the length of the α-helix and ultimately affect the integrity of the Toll-IL-1 receptor (TIR) domain. The functional mechanism of 3846 A/G might also involve a threonine phosphorylation signaling. This study may broaden the knowledge of TLR polymorphisms, lay the foundation for further functional research of CiTLR8 and provide potential markers as well as theoretical basis for resistance molecular breeding of grass carp against GCRV. [ABSTRACT FROM AUTHOR]

The dendritic processes of nociceptive neurons transduce external signals into neurochemical cues that alert the organism to potentially damaging stimuli. The receptive field for each sensory neuron is defined by its dendritic arbor, but the mechanisms that shape dendritic architecture are incompletely understood. Using the model nociceptor, the PVD neuron in C. elegans, we determined that two types of PVD lateral branches project along the dorsal/ventral axis to generate the PVD dendritic arbor: (1) Pioneer dendrites that adhere to the epidermis, and (2) Commissural dendrites that fasciculate with circumferential motor neuron processes. Previous reports have shown that the LIM homeodomain transcription factor MEC-3 is required for all higher order PVD branching and that one of its targets, the claudin-like membrane protein HPO-30, preferentially promotes outgrowth of pioneer branches. Here, we show that another MEC-3 target, the conserved TFIIA-like zinc finger transcription factor EGL-46, adopts the alternative role of specifying commissural dendrites. The known EGL-46 binding partner, the TEAD transcription factor EGL-44, is also required for PVD commissural branch outgrowth. Double mutants of hpo-30 and egl-44 show strong enhancement of the lateral branching defect with decreased numbers of both pioneer and commissural dendrites. Thus, HPO-30/Claudin and EGL-46/EGL-44 function downstream of MEC-3 and in parallel acting pathways to direct outgrowth of two distinct classes of PVD dendritic branches. [ABSTRACT FROM AUTHOR]