Nipah virus (NiV) and related viruses form a distinct henipavirus genus within the Paramyxoviridae family. NiV continues to spillover into the humans causing deadly outbreaks with increasing human-bat interaction. NiV encodes the large protein (L) and phosphoprotein (P) to form the viral RNA polymerase machinery. Their sequences show limited homologies to those of non-henipavirus paramyxoviruses. We report two cryo-electron microscopy (cryo-EM) structures of the Nipah virus (NiV) polymerase L-P complex, expressed and purified in either its full-length or truncated form. The structures resolve the RNA-dependent RNA polymerase (RdRp) and polyribonucleotidyl transferase (PRNTase) domains of the L protein, as well as a tetrameric P protein bundle bound to the L-RdRp domain. L-protein C-terminal regions are unresolved, indicating flexibility. Two PRNTase domain zinc-binding sites, conserved in most Mononegavirales, are confirmed essential for NiV polymerase activity. The structures further reveal anchoring of the P protein bundle and P protein X domain (XD) linkers on L, via an interaction pattern distinct among Paramyxoviridae. These interactions facilitate binding of a P protein XD linker in the nucleotide entry channel and distinct positioning of other XD linkers. We show that the disruption of the L-P interactions reduces NiV polymerase activity. The reported structures should facilitate rational antiviral-drug discovery and provide a guide for the functional study of NiV polymerase.
Nipah Virus/chemistry* ; Cryoelectron Microscopy ; Viral Proteins/genetics* ; RNA-Dependent RNA Polymerase/genetics* ; Phosphoproteins/genetics* ; Humans ; Models, Molecular ; Protein Binding

In order to determine the causative agents responsible for the lethality of tumor disease in breeders,liver,spleen and other tissues of dead chickens were collected,and pathogen detection,se-quencing and genetic evolution analysis were carried out by PCR.The results showed that all three samples were negative for reticuloendotheliosis virus(REV),samples 1 and 2 wereavian leukosis virus subgroup J(ALV-J)positive,and sample 3 was positive for ALV-J and Marek's disease virus(MDV),which preliminarily determined that the breeder died of ALV-J infection or ALV-J and MDV mixed infection.Among them,the ALV-J gp85 gene had the highest nucleotide homology with the reference strain of ALV-J,ranging from 87.70％to 99.30％,and was in the same branch with the reference strain of subgroup J.Amino acid homology ranged from 78.00％to 96.20％,with some mutations.The nucleotide homology between the MDV meq gene and the vv+strain was the highest,which was 98.00％-99.00％,and they were in the same branch.The homology of amino acids was 95.90％-98.20％,and there were multiple mutation sites,among which the 176th amino acid destroyed the original Pro repeat of the virus MDV meq due to the mutation of Pro to Arg or Ala,which may lead to the enhancement of its virulence.This study will provide a reference for the prevention and control of neoplastic diseases in breeders in this region.

In order to determine the causative agents responsible for the lethality of tumor disease in breeders,liver,spleen and other tissues of dead chickens were collected,and pathogen detection,se-quencing and genetic evolution analysis were carried out by PCR.The results showed that all three samples were negative for reticuloendotheliosis virus(REV),samples 1 and 2 wereavian leukosis virus subgroup J(ALV-J)positive,and sample 3 was positive for ALV-J and Marek's disease virus(MDV),which preliminarily determined that the breeder died of ALV-J infection or ALV-J and MDV mixed infection.Among them,the ALV-J gp85 gene had the highest nucleotide homology with the reference strain of ALV-J,ranging from 87.70％to 99.30％,and was in the same branch with the reference strain of subgroup J.Amino acid homology ranged from 78.00％to 96.20％,with some mutations.The nucleotide homology between the MDV meq gene and the vv+strain was the highest,which was 98.00％-99.00％,and they were in the same branch.The homology of amino acids was 95.90％-98.20％,and there were multiple mutation sites,among which the 176th amino acid destroyed the original Pro repeat of the virus MDV meq due to the mutation of Pro to Arg or Ala,which may lead to the enhancement of its virulence.This study will provide a reference for the prevention and control of neoplastic diseases in breeders in this region.

Oral squamous cell carcinoma(OSCC)is the predominant type of oral cancer,while some patients may develop oral multiple primary cancers(MPCs)with unclear etiology.This study aimed to investigate the clinicopathological characteristics and genomic alterations of oral MPCs.Clinicopathological data from patients with oral single primary carcinoma(SPC,n=202)and oral MPCs(n=34)were collected and compared.Copy number alteration(CNA)analysis was conducted to identify chromosomal-instability differences among oral MPCs,recurrent OSCC cases,and OSCC patients with lymph node metastasis.Whole-exome sequencing was employed to identify potential unique gene mutations in oral MPCs patients.Additionally,CNA and phylogenetic tree analyses were used to gain preliminary insights into the molecular characteristics of different primary tumors within individual patients.Our findings revealed that,in contrast to oral SPC,females predominated the oral MPCs(70.59%),while smoking and alcohol use were not frequent in MPCs.Moreover,long-term survival outcomes were poorer in oral MPCs.From a CNA perspective,no significant differences were observed between oral MPCs patients and those with recurrence and lymph node metastasis.In addition to commonly mutated genes such as CASP8,TP53 and MUC16,in oral MPCs we also detected relatively rare mutations,such as HS3ST6 and RFPL4A.Furthermore,this study also demonstrated that most MPCs patients exhibited similarities in certain genomic regions within individuals,and distinct differences of the similarity degree were observed between synchronous and metachronous oral MPCs.

Odontogenic keratocyst(OKC)is a common jaw cyst with a high recurrence rate.OKC combined with basal cell carcinoma as well as skeletal and other developmental abnormalities is thought to be associated with Gorlin syndrome.Moreover,OKC needs to be differentiated from orthokeratinized odontogenic cyst and other jaw cysts.Because of the different prognosis,differential diagnosis of several cysts can contribute to clinical management.We collected 519 cases,comprising a total of 2157 hematoxylin and eosin-stained images,to develop digital pathology-based artificial intelligence(AI)models for the diagnosis and prognosis of OKC.The Inception_v3 neural network was utilized to train and test models developed from patch-level images.Finally,whole slide image-level AI models were developed by integrating deep learning-generated pathology features with several machine learning algorithms.The AI models showed great performance in the diagnosis(AUC=0.935,95%CI:0.898-0.973)and prognosis(AUC=0.840,95%CI:0.751-0.930)of OKC.The advantages of multiple slides model for integrating of histopathological information are demonstrated through a comparison with the single slide model.Furthermore,the study investigates the correlation between AI features generated by deep learning and pathological findings,highlighting the interpretative potential of AI models in the pathology.Here,we have developed the robust diagnostic and prognostic models for OKC.The AI model that is based on digital pathology shows promise potential for applications in odontogenic diseases of the jaw.

Objective:To investigate the hemodynamic characteristics of transverse sinus with sigmoid sinus wall dehiscence (SSWD) of pulsatile tinnitus (PT) based on 4D flow MRI.Methods:Retrospective analysis was performed on all patients admitted to Beijing Friendship Hospital, Capital Medical University from January 2019 to January 2021 for dehiscent sigmoid plate pulsatile tinnitus. A total of 26 patients (sides) who met the criteria and underwent 4D flow MRI were included. A total of 26 subjects (46 sides), matched 1∶1 according to gender and age, were included in the normal healthy control group. Nonparametric rank sum test, Student′s t test, and ANOVA were performed by SPSS 19.0 software. Binary Logistic regression was applied to the data with statistical significance. Results:There were more patients with dominant drainage on the affected side in PT group than in control group (73.1% vs. 42.3%). The incidence of transverse with a focal intraluminal filling defect and tapered stenosis was higher than that in control group (21.7% vs. 69.2%; 17.4% vs. 42.3%). Average through-plane velocity and maximum through-plane velocity in PT group were higher than those in control group [(33.75±13.88) cm/s vs. (15.84±7.21) cm/s; (93.19±33.55) cm/s vs. (40.40±14.40) cm/s]. The middle part and proximal end of Flow avg (ml/s) in PT group were larger than those in control group [4.69 (2.87; 5.62) ml/s vs. 2.76 (1.67; 4.99) ml/s; 3.41 (2.16; 5.47) ml/s vs. 2.67 (1.68; 4.41) ml/s]. In control group, the velocity of transverse sinus changed relatively gently, while in PT group, the velocity of proximal sinus increased significantly. Binary Logistic regression showed that SSWD PT was independently correlated with proximal maximum flow velocity [ OR=1.086(1.029-1.146), P=0.003]. Conclusion:4D flow MRI showed that the dominant drainage and higher velocity at the proximal end of the transverse sinus might be an important hemodynamic characteristics of dehiscent sigmoid plate pulsatile tinnitus.

In light of the lack of reliable molecular markers for odontogenic myxoma (OM), the detection of copy number variation (CNV) may present a more objective method for assessing ambiguous cases. In this study, we employed multiregional microdissection sequencing to integrate morphological features with genomic profiling. This allowed us to reveal the CNV profiles of OM and compare them with dental papilla (DP), dental follicle (DF), and odontogenic fibroma (OF) tissues. We identified a distinct and robustly consistent CNV pattern in 93.75% (30/32) of OM cases, characterized by CNV gain events in chromosomes 4, 5, 8, 10, 12, 16, 17, 20, and 21. This pattern significantly differed from the CNV patterns observed in DP, DF, and OF. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated potential links between this CNV patterns and the calcium signaling pathway and salivary secretion, while Gene Ontology (GO) term analysis implicated CNV patterns in tumor adhesion, tooth development, and cell proliferation. Comprehensive CNV analysis accurately identified a case that was initially disputable between OF and OM as OM. Our findings provide a reliable diagnostic clue and fresh insights into the molecular biological mechanism underlying OM.
Humans ; DNA Copy Number Variations ; Odontogenic Tumors/diagnosis* ; Myxoma/genetics* ; Female ; Male ; Adult ; Adolescent ; Middle Aged ; Dental Papilla ; Young Adult ; Fibroma/genetics* ; Dental Sac ; Child

Oral leukoplakia is a common precursor lesion of oral squamous cell carcinoma, which indicates a high potential of malignancy. The malignant transformation of oral leukoplakia seriously affects patient survival and quality of life; however, it is difficult to identify oral leukoplakia patients who will develop carcinoma because no biomarker exists to predict malignant transformation for effective clinical management. As a major problem in the field of head and neck pathologies, it is imperative to identify biomarkers of malignant transformation in oral leukoplakia. In this review, we discuss the potential biomarkers of malignant transformation reported in the literature and explore the translational probabilities from bench to bedside. Although no single biomarker has yet been applied in the clinical setting, profiling for genomic instability might be a promising adjunct.

Odontogenic keratocysts (OKCs) are common cystic lesions of odontogenic epithelial origin that can occur sporadically or in association with naevoid basal cell carcinoma syndrome (NBCCS). OKCs are locally aggressive, cause marked destruction of the jaw bones and have a propensity to recur. PTCH1 mutations (at ∼80%) are frequently detected in the epithelia of both NBCCS-related and sporadic OKCs, suggesting that PTCH1 inactivation might constitutively activate sonic hedgehog (SHH) signalling and play a major role in disease pathogenesis. Thus, small molecule inhibitors of SHH signalling might represent a new treatment strategy for OKCs. However, studies on the molecular mechanisms associated with OKCs have been hampered by limited epithelial cell yields during OKC explant culture. Here, we constructed an isogenic PTCH1 cellular model of PTCH1 inactivation by introducing a heterozygous mutation, namely, c.403C>T (p.R135X), which has been identified in OKC patients, into a human embryonic stem cell line using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9) system. This was followed by the induction of epithelial differentiation. Using this in vitro isogenic cellular model, we verified that the PTCH1 heterozygous mutation causes ligand-independent activation of SHH signalling due to PTCH1 haploinsufficiency. This activation was found to be downregulated in a dose-dependent manner by the SHH pathway inhibitor GDC-0449. In addition, through inhibition of activated SHH signalling, the enhanced proliferation observed in these induced cells was suppressed, suggesting that GDC-0449 might represent an effective inhibitor of the SHH pathway for use during OKC treatment.
Anilides ; pharmacology ; Basal Cell Nevus Syndrome ; Hedgehog Proteins ; genetics ; pharmacology ; Humans ; Molecular Targeted Therapy ; Odontogenic Cysts ; genetics ; physiopathology ; therapy ; Odontogenic Tumors ; genetics ; physiopathology ; therapy ; Pyridines ; pharmacology

Odontogenic keratocysts (OKCs) are common cystic lesions of odontogenic epithelial origin that can occur sporadically or in association with naevoid basal cell carcinoma syndrome (NBCCS).OKCs are locally aggressive,cause marked destruction of the jaw bones and have a propensity to recur.PTCH1 mutations (at ～80％) are frequently detected in the epithelia of both NBCCS-related and sporadic OKCs,suggesting that PTCH1 inactivation might constitutively activate sonic hedgehog (SHH) signalling and play a major role in disease pathogenesis.Thus,small molecule inhibitors of SHH signalling might represent a new treatment strategy for OKCs.However,studies on the molecular mechanisms associated with OKCs have been hampered by limited epithelial cell yields during OKC explant culture.Here,we constructed an isogenic PTCH1R135X/+ cellular model of PTCH1 inactivation by introducing a heterozygous mutation,namely,c.403C＞T (p.R135X),which has been identified in OKC patients,into a human embryonic stem cell line using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Casg) system.This was followed by the induction of epithelial differentiation.Using this in vitro isogenic cellular model,we verified that the PTCH1R135X/+ heterozygous mutation causes ligand-independent activation of SHH signalling due to PTCH1 haploinsufficiency.This activation was found to be downregulated in a dose-dependent manner by the SHH pathway inhibitor GDC-0449.In addition,through inhibition of activated SHH signalling,the enhanced proliferation observed in these induced cells was suppressed,suggesting that GDC-0449 might represent an effective inhibitor of the SHH pathway for use during OKC treatment.