Lipid Droplets Are Beneficial for Rabies Virus Replication by Facilitating Viral Budding.

Rabies is an old zoonotic disease caused by rabies virus (RABV), but the pathogenic mechanism of RABV is still not completely understood. Lipid droplets (LDs) have been reported to play a role in pathogenesis of several viruses. However, their role in RABV infection remains unclear. Here, we initially found that RABV infection upregulated LD production in multiple cells and mouse brains. After treatment with atorvastatin, a specific inhibitor of LDs, RABV replication in N2a cells decreased. Then we found that RABV infection could upregulate N-myc downstream regulated gene-1 (NDRG1), which in turn enhanced the expression of diacylglycerol acyltransferase 1/2 (DGAT1/2). DGAT1/2 could elevate cellular triglyceride synthesis and ultimately promote intracellular LD formation. Furthermore, we found that RABV-M and RABV-G, which were mainly involved in the viral budding process, could colocalize with LDs, indicating that RABV might utilize LDs as a carrier to facilitate viral budding and eventually increase virus production. Taken together, our study reveals that lipid droplets are beneficial for RABV replication, and their biogenesis is regulated via the NDRG1-DGAT1/2 pathway, which provides novel potential targets for developing anti-RABV drugs. IMPORTANCE Lipid droplets have been proven to play an important role in viral infections, but their role in RABV infection has not yet been elaborated. Here, we find that RABV infection upregulates the generation of LDs by enhancing the expression of N-myc downstream regulated gene-1 (NDRG1). Then NDRG1 elevated cellular triglycerides synthesis by increasing the activity of diacylglycerol acyltransferase 1/2 (DGAT1/2), which promotes the biogenesis of LDs. RABV-M and RABV-G, which are the major proteins involved in viral budding, could utilize LDs as a carrier for transport to cell membrane, resulting in enhanced virus budding. Our findings will extend the knowledge of lipid metabolism in RABV infection and help to explore potential therapeutic targets for RABV.

Adaptive Mutation in the Main Protease Cleavage Site of Feline Coronavirus Renders the Virus More Resistant to Main Protease Inhibitors.

The rapid global emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused serious health problems, highlighting the urgent need for antiviral drugs. The viral main protease (Mpro) plays an important role in viral replication and thus remains the target of choice for the prevention or treatment of several viral diseases due to high sequence and structural conservation. Prolonged use of viral protease inhibitors can lead to the development of mutants resistant to those inhibitors and to many of the available antiviral drugs. Here, we used feline infectious peritonitis virus (FIPV) as a model to investigate its development of resistance under pressure from the Mpro inhibitor GC376. Passage of wild-type (WT) FIPV in the presence of GC376 selected for a mutation in the nsp12 region where Mpro cleaves the substrate between nsp12 and nsp13. This mutation confers up to 3-fold resistance to GC376 and nirmatrelvir, as determined by EC50 assay. In vitro biochemical and cellular experiments confirmed that FIPV adapts to the stress of GC376 by mutating the nsp12 and nsp13 hydrolysis site to facilitate cleavage by Mpro and release to mediate replication and transcription. Finally, we demonstrate that GC376 cannot treat FIP-resistant mutants that cause FIP in animals. Taken together, these results suggest that Mpro affects the replication of coronaviruses (CoVs) and the drug resistance to GC376 by regulating the amount of RdRp from a distant site. These findings provide further support for the use of an antiviral drug combination as a broad-spectrum therapy to protect against contemporary and emerging CoVs. IMPORTANCE CoVs cause serious human infections, and antiviral drugs are currently approved to treat these infections. The development of protease-targeting therapeutics for CoV infection is hindered by resistance mutations. Therefore, we should pay attention to its resistance to antiviral drugs. Here, we identified possible mutations that lead to relapse after clinical treatment of FIP. One amino acid substitution in the nsp12 polymerase at the Mpro cleavage site provided low-level resistance to GC376 after selection exposure to the GC376 parental nucleoside. Resistance mutations enhanced FIPV viral fitness in vitro and attenuated the therapeutic effect of GC376 in an animal model of FIPV infection. Our research explains the evolutionary characteristics of coronaviruses under antiviral drugs, which is helpful for a more comprehensive understanding of the molecular basis of virus resistance and provides important basic data for the effective prevention and control of CoVs.

Alpha-synuclein supports type 1 interferon signalling in neurons and brain tissue.

The protein alpha-synuclein is predominantly expressed in neurons and is associated with neurodegenerative diseases like Parkinson's disease and dementia with Lewy bodies. However, the normal function of alpha-synuclein in neurons is not clearly defined. We have previously shown that mice lacking alpha-synuclein expression exhibit markedly increased viral growth in the brain, increased mortality and increased neuronal cell death, implicating alpha-synuclein in the neuronal innate immune response. To investigate the mechanism of alpha-synuclein-induced immune responses to viral infections in the brain, we challenged alpha-synuclein knockout mice and human alpha-synuclein knockout dopaminergic neurons with RNA virus infection and discovered that alpha-synuclein is required for neuronal expression of interferon-stimulated genes. Furthermore, human alpha-synuclein knockout neurons treated with type 1 interferon failed to induce a broad range of interferon stimulated genes, implying that alpha-synuclein interacts with type 1 interferon signalling. We next found that alpha-synuclein accumulates in the nucleus of interferon-treated human neurons after interferon treatment and we demonstrated that interferon-mediated phosphorylation of STAT2 is dependent on alpha-synuclein expression in human neurons. Next, we found that activated STAT2 co-localizes with alpha-synuclein following type 1 interferon stimulation in neurons. Finally, we found that brain tissue from patients with viral encephalitis expresses increased levels of phospho-serine129 alpha-synuclein in neurons. Taken together, our results show that alpha-synuclein expression supports neuron-specific interferon responses by localizing to the nucleus, supporting STAT2 activation, co-localizing with phosphorylated STAT2 in neurons and supporting expression of interferon-stimulated genes. These data provide a novel mechanism that links interferon activation and alpha-synuclein function in neurons.

Exploring the determinants of food choice in Chinese immigrants living in Australia and Chinese people living in mainland China: A qualitative study.

BACKGROUND: The present study aimed to qualitatively explore the food choice determinants of both Chinese immigrants living in Australia and Chinese people living in mainland China. METHODS: Eight Chinese Australian participants (female, n = 5; male, n = 3) and ten mainland Chinese participants (female, n = 5; male, n = 5) were recruited from Australia (primarily in Melbourne, Victoria) and China (predominantly in Zhengzhou, Henan province) between June 2021 and March 2022. Participants were diverse in age, socio-economic background, occupation and health status. Semi-structured in-depth interviews were conducted in Mandarin either face-to-face or using online video/voice calls. Interviews were audio-recorded and transcribed verbatim. Investigator triangulation was used to enhance scientific rigour. RESULTS: Four themes were identified: (1) food choice determinants were shaped by traditional and modern nutrition perceptions and personal food philosophy; (2) physiological responses to food provide direct feedback that impacts future food choices; (3) consideration of convenience was a predominant influencer of food choice; and (4) the differences in food environments between China and Australia promoted distinctive food choice determinants for Chinese people. CONCLUSIONS: Chinese Australian and mainland Chinese participants' food choices are shaped by traditional Chinese nutrition philosophy, modern Western nutrition science and the contemporary food environment. There are clear cultural characteristics in their food choice determinants that should be considered by health educators, nutrition professionals and nutrition policymakers when developing culturally appropriate health interventions for Chinese people.

Establishment of Full-Length cDNA Clones and an Efficient Oral Infection Model for Feline Coronavirus in Cats.

Feline infectious peritonitis virus (FIPV) is the etiologic agent of feline infectious peritonitis (FIP) and causes fatal disease in cats of almost all ages. Currently, there are no clinically approved drugs or effective vaccines for FIP. Furthermore, the pathogenesis of FIP is still not fully understood. There is an urgent need for an effective infection model of feline infectious peritonitis induced by FIPV. Here, we constructed a field type I FIPV full-length cDNA clone, pBAC-QS, corresponding to the isolated FIPV QS. By replacing the FIPV QS spike gene with the commercially available type II FIPV 79-1146 (79-1146_CA) spike gene, we established and rescued a recombinant virus, designated rQS-79. Moreover, we constructed 79-1146_CA infectious full-length cDNA pBAC-79-1146_CA, corresponding to recombinant feline coronavirus (FCoV) 79-1146_CA (r79-1146_CA). In animal experiments with 1- to 2-year-old adult cats orally infected with the recombinant virus, rQS-79 induced typical FIP signs and 100% mortality. In contrast to cats infected with rQS-79, cats infected with 79-1146_CA did not show obvious signs. Furthermore, by rechallenging rQS-79 in surviving cats previously infected with 79-1146_CA, we found that there was no protection against rQS-79 with different titers of neutralizing antibodies. However, high titers of neutralizing antibodies may help prolong the cat survival time. Overall, we report the first reverse genetics of virulent recombinant FCoV (causing 100% mortality in adult cats) and attenuated FCoV (causing no mortality in adult cats), which will be powerful tools to study pathogenesis, antiviral drugs, and vaccines for FCoV. IMPORTANCE Tissue- or cell culture-adapted feline infectious peritonitis virus (FIPV) usually loses pathogenicity. To develop a highly virulent FIPV, we constructed a field isolate type I FIPV full-length clone with the spike gene replaced by the 79-1146 spike gene, corresponding to a virus named rQS-79, which induces high mortality in adult cats. rQS-79 represents the first described reverse genetics system for highly pathogenic FCoV. By further constructing the cell culture-adapted FCoV 79-1146_CA, we obtained infectious clones of virulent and attenuated FCoV. By in vitro and in vivo experiments, we established a model that can serve to study the pathogenic mechanisms of FIPV. Importantly, the wild-type FIPV replicase skeleton of serotype I will greatly facilitate the screening of antiviral drugs, both in vivo and in vitro.

The structural basis of African swine fever virus core shell protein p15 binding to DNA.

African swine fever (ASF) is an acute, hemorrhagic, and highly contagious disease caused by African swine fever virus (ASFV). The mortality rate of acute infection up to 100% have posed an unprecedented challenge of the swine industry. Currently no commercial antiviral drug is available for the control and treatment of ASFV. The structural resolution of ASFV virions reveals the details of ASFV morphogenesis, providing a new perspective for the research and promotion of the development of ASFV vaccines. Although the architecture of ASFV have been solved via cryo-EM, the structural details of four of the five viral layers remain unclear (except the outer capsid). In this study, we resolved the crystal structure of the ASFV core shell protein p15. The secondary structural elements of a protomer include four α-helix structures and six antiparallel ß-strands. Further analysis revealed that ASFV p15 forms disulfide-linked trimers between the Cys9 from one protomer and Cys30 from other protomer. Additionally, the nucleic acid-binding property was characterized by electrophoretic mobility shift assay. Two critical amino acid Lys10 and Lys39 have been identified which is essential to the nucleic acid-binding affinity of ASFV p15. Together, these findings may provide new insight into antiviral drug development.

Chemodivergent Synthesis of Indeno[1,2-b]indoles and Isoindolo[2,1-a]indoles via Mn(III)-Mediated or Electrochemical Intramolecular Radical Cross-Dehydrogenative Coupling.

Chemodivergent synthesis of indeno[1,2-b]indoles and isoindolo[2,1-a]indoles from the same starting materials involving radical cross-dehydrogenative couplings have been developed. Mn(OAc)3·2H2O selectively promoted an intramolecular radical C-H/C-H dehydrogenative coupling reaction to provide indeno[1,2-b]indoles, while an intramolecular radical C-H/N-H dehydrogenative coupling reaction could proceed via electrochemistry to deliver isoindolo[2,1-a]indoles. Plausible mechanisms of the chemodivergent reactions were proposed.

Shape memory polymer composites (SMPCs) using interconnected nanowire network foams as reinforcements.

Shape memory polymers (SMPs), although offer a suite of advantages such as ease of processability and lower density, lag behind their shape memory alloy counterparts, in terms of mechanical properties such as recovery stress and cyclability. Reinforcing SMPs with inorganic nanowires and carbon nanotubes (CNTs) is a sought-after pathway for tailoring their mechanical properties. Here, inorganic nanowires also offer the added advantage of covalently binding the fillers to the surrounding polymer matrices via organic molecules. The SMP composites (SMPCs) thus obtained have well-engineered nanowire-polymer interfaces, which could be used to tune their mechanical properties. A well-known method of fabricating SMPCs involving casting dispersions of nanowires (or CNTs) in mixtures of monomers and crosslinkers typically results in marginal improvements in the mechanical properties of the fabricated SMPCs. This is owed to the constraints imposed by the rule-of-mixture principles. To circumvent this limitation, a new method for SMPC fabrication is designed and presented. This involves infiltrating polymers into pre-fabricated nanowire foams. The pre-fabricated foams were fabricated by consolidating measured quantities of nanowires and a sacrificial material, such as (NH4)2CO3, followed by heating the consolidated mixtures for subliming the sacrificial material. Similar to the case of traditional composites, use of silanes to functionalize the nanowire surfaces allowed for the formation of bonds between both the nanowire-nanowire and the nanowire-polymer interfaces. SMPCs fabricated using TiO2nanowires and SMP composed of neopentyl glycol diglycidyl ether and poly(propylene glycol) bis(2-aminopropyl ether) (Jeffamine D230) in a 2:1 molar ratio exhibited a 300% improvement in the elastic modulus relative to that of the SMP. This increase was significantly higher than SMPC made using the traditional fabrication route. Well-known powder metallurgy techniques employed for the fabrication of these SMPCs make this strategy applicable for obtaining other SMPCs of any desired shape and chemical composition.

Comparative Transcriptome Analysis Reveals That WSSV IE1 Protein Plays a Crucial Role in DNA Replication Control.

For DNA viruses, the immediate-early (IE) proteins are generally essential regulators that manipulate the host machinery to support viral replication. Recently, IE1, an IE protein encoded by white spot syndrome virus (WSSV), has been demonstrated to function as a transcription factor. However, the target genes of IE1 during viral infection remain poorly understood. Here, we explored the host target genes of IE1 using RNAi coupled with transcriptome sequencing analysis. A total of 429 differentially expressed genes (DEGs) were identified from penaeid shrimp, of which 284 genes were upregulated and 145 genes were downregulated after IE1 knockdown. GO and KEGG pathway enrichment analysis revealed the identified DEGs are significantly enriched in the minichromosome maintenance (MCM) complex and DNA replication, indicating that IE1 plays a critical role in DNA replication control. In addition, it was found that Penaeus vannamei MCM complex genes were remarkably upregulated after WSSV infection, while RNAi-mediated knockdown of PvMCM2 reduced the expression of viral genes and viral loads at the early infection stage. Finally, we demonstrated that overexpression of IE1 promoted the expression of MCM complex genes as well as cellular DNA synthesis in insect High-Five cells. Collectively, our current data suggest that the WSSV IE1 protein is a viral effector that modulates the host DNA replication machinery for viral replication.

Abrogation of Lupus Nephritis in Somatic Hypermutation-Deficient MRL/lpr Mice.

Systemic lupus erythematosus (SLE) is an autoimmune disease posing threats to multiple organs in the human body. As a typical manifestation of SLE, lupus nephritis is characterized by a series of pathological changes in glomerulus as well as accumulation of pathogenic autoreactive IgG with complement in the kidney that dramatically disrupts renal functions. Activation-induced deaminase (AID), which governs both somatic hypermutation (SHM) and class-switch recombination (CSR), has been shown to be essential for the regulation of SLE. However, the relative contributions of SHM and CSR to SLE pathology have not been determined. Based on the available AIDG23S mice, we successfully established an AIDG23S MRL/lpr mouse model, in which SHM is specifically abolished, although CSR is largely unaffected. We found that the abrogation of SHM effectively alleviated SLE-associated histopathological alterations, such as expansion of the mesangial matrix and thickening of the basement membrane of Bowman's capsule as well as infiltration of inflammatory cells. Compared with SLE mice, AIDG23S MRL/lpr mice exhibited decreased proteinuria, blood urea nitrogen, and creatinine, indicating that the loss of SHM contributed to the recovery of renal functions. As a consequence, the life span of those SHM-deficient MRL/lpr mice was extended. Together, we provide direct evidence pinpointing a vital role of SHM in the control of SLE development.

Are PARKIN patients ideal candidates for dopaminergic cell replacement therapies?

Parkinson's is a heterogeneous, complex condition. Stratification of Parkinson's subtypes will be essential to identify those that will benefit most from a cell replacement therapy. Foetal mesencephalic grafts can alleviate motor symptoms in some Parkinson's patients. However, on-going synucleinopathy results in the grafts eventually developing Lewy bodies, and they begin to fail. We propose that Parkinson's patients with PARKIN mutations may benefit most from a cell replacement therapy because (a) they often lack synucleinopathy, and (b) their neurodegeneration is often confined to the nigrostriatal pathway. While patients with PARKIN mutations exhibit clinical signs of Parkinson's, post-mortem studies to date indicate the majority lack Lewy bodies suggesting the nigral dopaminergic neurons are lost in a cell autonomous manner independent of α-synuclein mechanisms. Furthermore, these patients are usually younger, slow progressing and typically do not suffer from complex non-nigral symptoms that are unlikely to be ameliorated by a cell replacement therapy. Transplantation of dopaminergic cells into the putamen of these patients will provide neurons with wild-type PARKIN expression to re-innervate the striatum. The focal nature of PARKIN-mediated neurodegeneration and lack of active synucleinopathy in most young-onset cases makes these patients ideal candidates for a dopaminergic cell replacement therapy. Strategies to improve the outcome of cell replacement therapies for sporadic Parkinson's include the use of adjunct therapeutics that target α-synuclein spreading and the use of genetically engineered grafts that are resistant to synucleinopathy.

Engineering synucleinopathy-resistant human dopaminergic neurons by CRISPR-mediated deletion of the SNCA gene.

An emerging treatment for Parkinson's disease (PD) is cell replacement therapy. Authentic midbrain dopaminergic (mDA) neuronal precursors can be differentiated from human embryonic stem cells (hESCs) and human induced pluripotent stem cells (iPSCs). These laboratory-generated mDA cells have been demonstrated to mature into functional dopaminergic neurons upon transplantation into preclinical models of PD. However, clinical trials with human fetal mesenchephalic cells have shown that cell replacement grafts in PD are susceptible to Lewy body formation suggesting host-to-graft transfer of α-synuclein pathology. Here, we have used CRISPR/Cas9n technology to delete the endogenous SNCA gene, encoding for α-synuclein, in a clinical-grade hESC line to generate SNCA+/- and SNCA-/- cell lines. These hESC lines were first differentiated into mDA neurons, and then challenged with recombinant α-synuclein preformed fibrils (PFFs) to seed the formation for Lewy-like pathology as measured by phosphorylation of serine-129 of α-synuclein (pS129-αSyn). Wild-type neurons were fully susceptible to the formation of protein aggregates positive for pS129-αSyn, while SNCA+/- and SNCA-/- neurons exhibited significant resistance to the formation of this pathological mark. This work demonstrates that reducing or completely removing SNCA alleles by CRISPR/Cas9n-mediated gene editing confers a measure of resistance to Lewy pathology.

A recombinant canine distemper virus expressing interleukin-7 enhances humoral immunity.

Canine distemper (CD) causes gastrointestinal and respiratory and/or neurological signs and results in high morbidity and mortality, remaining a threat to carnivores around the world. Live-attenuated vaccines have been widely used to reduce the number of CD outbreaks, but efforts are still needed to improve immune efficiency. Interleukin-7 (IL-7) has been reported to boost host immunity by recruiting follicle helper T (TFH) or germinal center (GC) B cells. Here, we constructed a recombinant canine distemper virus (rCDV) by reverse genetics and evaluated the properties of six intergenic sites for insertion of a foreign gene. We found that the P/M intergenic region was the optimal site to insert a foreign gene into the CDV genome. The effect of overexpressing IL-7 on rCDV immunogenicity was then evaluated in a mouse model. We found that mice immunized with rCDV-IL7 could not significantly enhance the maturation of dendritic cells (DCs) but significantly facilitated the generation of TFH cells, GC B cells and plasma cells (PCs), as well as the formation of GCs, consequently enhancing the production of CDV-specific neutralizing antibodies and total IgG. Together, these results suggested that the overexpression of IL-7 by rCDV could enhance humoral responses by activating the TFH-GC B-PC axis, which will help to improve vaccines for CD.

Silencing MR-1 attenuates atherosclerosis in ApoE-/- mice induced by angiotensin II through FAK-Akt-mTOR-NF-kappaB signaling pathway.

Myofibrillogenesis regulator-1 (MR-1) is a novel protein involved in cellular proliferation, migration, inflammatory reaction and signal transduction. However, little information is available on the relationship between MR-1 expression and the progression of atherosclerosis. Here we report atheroprotective effects of silencing MR-1 in a model of Ang II-accelerated atherosclerosis, characterized by suppression focal adhesion kinase (FAK) and nuclear factor kappaB (NF-κB) signaling pathway, and atherosclerotic lesion macrophage content. In this model, administration of the siRNA-MR-1 substantially attenuated Ang II-accelerated atherosclerosis with stabilization of atherosclerotic plaques and inhibited FAK, Akt, mammalian target of rapamycin (mTOR) and NF-kB activation, which was associated with suppression of inflammatory factor and atherogenic gene expression in the artery. In vitro studies demonstrated similar changes in Ang II-treated vascular smooth muscle cells (VSMCs) and macrophages: siRNA-MR-1 inhibited the expression levels of proinflammatory factor. These studies uncover crucial proinflammatory mechanisms of Ang II and highlight actions of silencing MR-1 to inhibit Ang II signaling, which is atheroprotective.

Nanowire-based thermoelectrics.

Research on thermoelectrics has seen a huge resurgence since the early 1990s. The ability of tuning a material's electrical and thermal transport behavior upon nanostructuring has led to this revival. Nevertheless, thermoelectric performances of nanowires and related materials lag far behind those achieved with thin-film superlattices and quantum dot-based materials. This is despite the fact that nanowires offer many distinct advantages in enhancing the thermoelectric performances of materials. The simplicity of the strategy is the first and foremost advantage. For example, control of the nanowire diameters and their surface roughnesses will aid in enhancing their thermoelectric performances. Another major advantage is the possibility of obtaining high thermoelectric performances using simpler nanowire chemistries (e.g., elemental and binary compound semiconductors), paving the way for the fabrication of thermoelectric modules inexpensively from non-toxic elements. In this context, the topical review provides an overview of the current state of nanowire-based thermoelectrics. It concludes with a discussion of the future vision of nanowire-based thermoelectrics, including the need for developing strategies aimed at the mass production of nanowires and their interface-engineered assembly into devices. This eliminates the need for trial-and-error strategies and complex chemistries for enhancing the thermoelectric performances of materials.

Single-nucleus chromatin landscape dataset of mouse brain development and aging.

The development and aging of the brain constitute a lifelong dynamic process, marked by structural and functional changes that entail highly coordinated cellular differentiation and epigenetic regulatory mechanisms. Chromatin accessibility serves as the foundational basis for genetic activity. However, the holistic and dynamic chromatin landscape that spans various brain regions throughout development and ageing remains predominantly unexplored. In this study, we employed single-nucleus ATAC-seq to generate comprehensive chromatin accessibility maps, incorporating data from 69,178 cells obtained from four distinct brain regions - namely, the olfactory bulb (OB), cerebellum (CB), prefrontal cortex (PFC), and hippocampus (HP) - across key developmental time points at 7 P, 3 M, 12 M, and 18 M. We delineated the distribution of cell types across different age stages and brain regions, providing insight into chromatin accessible regions and key transcription factors specific to different cell types. Our data contribute to understanding the epigenetic basis of the formation of different brain regions, providing a dynamic landscape and comprehensive resource for revealing gene regulatory programs during brain development and aging.

Progress of Mitochondrial Function Regulation in Cardiac Regeneration.

Heart failure and myocardial infarction, global health concerns, stem from limited cardiac regeneration post-injury. Myocardial infarction, typically caused by coronary artery blockage, leads to cardiac muscle cell damage, progressing to heart failure. Addressing the adult heart's minimal self-repair capability is crucial, highlighting cardiac regeneration research's importance. Studies reveal a metabolic shift from anaerobic glycolysis to oxidative phosphorylation in neonates as a key factor in impaired cardiac regeneration, with mitochondria being central. The heart's high energy demands rely on a robust mitochondrial network, essential for cellular energy, cardiac health, and regenerative capacity. Mitochondria's influence extends to redox balance regulation, signaling molecule interactions, and apoptosis. Changes in mitochondrial morphology and quantity also impact cardiac cell regeneration. This article reviews mitochondria's multifaceted role in cardiac regeneration, particularly in myocardial infarction and heart failure models. Understanding mitochondrial function in cardiac regeneration aims to enhance myocardial infarction and heart failure treatment methods and insights.

Targeted next-generation sequencing reveals the genetic mechanism of Chinese Marfan syndrome cohort with ocular manifestation.

BACKGROUND: Marfan syndrome (MFS) is a hereditary connective tissue disorder involving multiple systems, including ophthalmologic abnormalities. Most cases are due to heterozygous mutations in the fibrillin-1 gene (FBN1). Other associated genes include LTBP2, MYH11, MYLK, and SLC2A10. There is significant clinical overlap between MFS and other Marfan-like disorders. PURPOSE: To expand the mutation spectrum of FBN1 gene and validate the pathogenicity of Marfan-related genes in patients with MFS and ocular manifestations. METHODS: We recruited 318 participants (195 cases, 123 controls), including 59 sporadic cases and 88 families. All patients had comprehensive ophthalmic examinations showing ocular features of MFS and met Ghent criteria. Additionally, 754 cases with other eye diseases were recruited. Panel-based next-generation sequencing (NGS) screened mutations in 792 genes related to inherited eye diseases. RESULTS: We detected 181 mutations with an 84.7% detection rate in sporadic cases and 87.5% in familial cases. The overall detection rate was 86.4%, with FBN1 accounting for 74.8%. In cases without FBN1 mutations, 23 mutations from seven Marfan-related genes were identified, including four pathogenic or likely pathogenic mutations in LTBP2. The 181 mutations included 165 missenses, 10 splicings, three frameshifts, and three nonsenses. FBN1 accounted for 53.0% of mutations. The most prevalent pathogenic mutation was FBN1 c.4096G>A. Additionally, 94 novel mutations were detected, with 13 de novo mutations in 14 families. CONCLUSION: We expanded the mutation spectrum of the FBN1 gene and provided evidence for the pathogenicity of other Marfan-related genes. Variants in LTBP2 may contribute to the ocular manifestations in MFS, underscoring its role in phenotypic diversity.

Feline infectious peritonitis virus ORF7a is a virulence factor involved in inflammatory pathology in cats.

A hyperinflammatory response is a prominent feature of feline infectious peritonitis (FIP), but the mechanisms behind the feline infectious peritonitis virus (FIPV)-induced cytokine storm in the host have not been clarified. Studies have shown that coronaviruses encode accessory proteins that are involved in viral replication and associated with viral virulence, the inflammatory response and immune regulation. Here, we found that FIPV ORF7a gene plays a key role in viral infection and host proinflammatory responses. The recombinant FIPV strains lacking ORF7a (rQS-79Δ7a) exhibit low replication rates in macrophages and do not induce dramatic upregulation of inflammatory factors. Furthermore, through animal experiments, we found that the rQS-79Δ7a strain is nonpathogenic and do not cause symptoms of FIP in cats. Unexpectedly, after three vaccinations with rQS-79Δ7a strain, humoral and cellular immunity was increased and provided protection against virulent strains in cats, and the protection rate reaches 40%. Importantly, our results demonstrated that ORF7a is a key virulence factor that exacerbates FIPV infection and inflammatory responses. Besides, our findings will provide novel implications for future development of live attenuated FIPV vaccines.