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1.
Nature ; 612(7941): 748-757, 2022 12.
Article in English | MEDLINE | ID: mdl-36477529

ABSTRACT

Middle East respiratory syndrome coronavirus (MERS-CoV) and several bat coronaviruses use dipeptidyl peptidase-4 (DPP4) as an entry receptor1-4. However, the receptor for NeoCoV-the closest known MERS-CoV relative found in bats-remains unclear5. Here, using a pseudotype virus entry assay, we found that NeoCoV and its close relative, PDF-2180, can efficiently bind to and use specific bat angiotensin-converting enzyme 2 (ACE2) orthologues and, less favourably, human ACE2 as entry receptors through their receptor-binding domains (RBDs) on the spike (S) proteins. Cryo-electron microscopy analysis revealed an RBD-ACE2 binding interface involving protein-glycan interactions, distinct from those of other known ACE2-using coronaviruses. We identified residues 337-342 of human ACE2 as a molecular determinant restricting NeoCoV entry, whereas a NeoCoV S pseudotyped virus containing a T510F RBD mutation efficiently entered cells expressing human ACE2. Although polyclonal SARS-CoV-2 antibodies or MERS-CoV RBD-specific nanobodies did not cross-neutralize NeoCoV or PDF-2180, an ACE2-specific antibody and two broadly neutralizing betacoronavirus antibodies efficiently inhibited these two pseudotyped viruses. We describe MERS-CoV-related viruses that use ACE2 as an entry receptor, underscoring a promiscuity of receptor use and a potential zoonotic threat.


Subject(s)
Angiotensin-Converting Enzyme 2 , Chiroptera , Middle East Respiratory Syndrome Coronavirus , Receptors, Virus , Virus Internalization , Animals , Humans , Angiotensin-Converting Enzyme 2/metabolism , Chiroptera/metabolism , Chiroptera/virology , Cryoelectron Microscopy , Middle East Respiratory Syndrome Coronavirus/classification , Middle East Respiratory Syndrome Coronavirus/isolation & purification , Middle East Respiratory Syndrome Coronavirus/metabolism , Protein Binding , Receptors, Virus/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Dipeptidyl Peptidase 4/metabolism , Viral Zoonoses
2.
EMBO J ; 41(6): e108544, 2022 03 15.
Article in English | MEDLINE | ID: mdl-34850409

ABSTRACT

Since numerous RNAs and RBPs prevalently localize to active chromatin regions, many RNA-binding proteins (RBPs) may be potential transcriptional regulators. RBPs are generally thought to regulate transcription via noncoding RNAs. Here, we describe a distinct, dual mechanism of transcriptional regulation by the previously uncharacterized tRNA-modifying enzyme, hTrmt13. On one hand, hTrmt13 acts in the cytoplasm to catalyze 2'-O-methylation of tRNAs, thus regulating translation in a manner depending on its tRNA-modification activity. On the other hand, nucleus-localized hTrmt13 directly binds DNA as a transcriptional co-activator of key epithelial-mesenchymal transition factors, thereby promoting cell migration independent of tRNA-modification activity. These dual functions of hTrmt13 are mutually exclusive, as it can bind either DNA or tRNA through its CHHC zinc finger domain. Finally, we find that hTrmt13 expression is tightly associated with poor prognosis and survival in diverse cancer patients. Our discovery of the noncatalytic roles of an RNA-modifying enzyme provides a new perspective for understanding epitranscriptomic regulation.


Subject(s)
RNA, Transfer , tRNA Methyltransferases , Humans , Methylation , RNA/metabolism , RNA Processing, Post-Transcriptional , RNA, Transfer/metabolism , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , tRNA Methyltransferases/genetics , tRNA Methyltransferases/metabolism
3.
Proc Natl Acad Sci U S A ; 119(39): e2204355119, 2022 09 27.
Article in English | MEDLINE | ID: mdl-36122201

ABSTRACT

Winter annual life history is conferred by the requirement for vernalization to promote the floral transition and control the timing of flowering. Here we show using winter oilseed rape that flowering time is controlled by inflorescence bud dormancy in addition to vernalization. Winter warming treatments given to plants in the laboratory and field increase flower bud abscisic acid levels and delay flowering in spring. We show that the promotive effect of chilling reproductive tissues on flowering time is associated with the activity of two FLC genes specifically silenced in response to winter temperatures in developing inflorescences, coupled with activation of a BRANCHED1-dependent bud dormancy transcriptional module. We show that adequate winter chilling is required for normal inflorescence development and high yields in addition to the control of flowering time. Because warming during winter flower development is associated with yield losses at the landscape scale, our work suggests that bud dormancy activation may be important for effects of climate change on winter arable crop yields.


Subject(s)
Brassica napus , Crops, Agricultural , Flowers , Seasons , Abscisic Acid/metabolism , Brassica napus/growth & development , Crops, Agricultural/growth & development , Flowers/physiology , Gene Expression Regulation, Plant
4.
PLoS Genet ; 18(9): e1010373, 2022 09.
Article in English | MEDLINE | ID: mdl-36095024

ABSTRACT

Prostate cancer is the most inheritable cancer with approximately 42% of disease risk attributed to inherited factors by studies of twins, indicating the importance of additional genetic screening to identify predisposition variants. However, only DNA damage repair (DDR) genes have been investigated thoroughly in prostate cancer. To determine the comprehensive germline mutation landscape in Chinese prostate cancer patients, we performed whole exome sequencing in 100 Han Chinese patients with prostate cancer in Hong Kong and identified deleterious germline mutations. A total of 36 deleterious germline variants in 25 genes were identified in 29% patients. Variants were found in eight pathways, including DNA methylation, DDR, and tyrosine-protein kinase. These findings were validated in an independent Chinese cohort of 167 patients with prostate cancer in Shanghai. Seven common deleterious-variant-containing genes were found in discovery cohort (7/25, 28%) and validation cohort (7/28, 25%) with three genes not described before (LDLR, MYH7 and SUGCT) and four genes previously reported (FANCI, ITGA6, PABPC1 and RAD54B). When comparing with that of a cohort of East Asian healthy individuals, 12 non-DDR novel potential predisposition genes (ADGRG1, CHD4, DNMT3A, ERBB3, GRHL1, HMBS, LDLR, MYH7, MYO6, NT5C2, NUP98 and SUGCT) were identified using the discovery and validation cohorts, which have not been previously reported in prostate cancer patients in all ethnic groups. Taken together, this study reveals a comprehensive germline mutation landscape in Chinese prostate cancer patients and discovers 12 novel non-DDR predisposition genes to lay the groundwork for the optimization of genetic screening.


Subject(s)
Germ-Line Mutation , Prostatic Neoplasms , China , Genetic Predisposition to Disease , Humans , Male , Prostatic Neoplasms/genetics , Protein Kinases/genetics , Tyrosine/genetics , Exome Sequencing
5.
Plant Biotechnol J ; 2024 May 30.
Article in English | MEDLINE | ID: mdl-38816933

ABSTRACT

Multiple distinct specialized regions shape the architecture of maize leaves. Among them, the fringe-like and wedge-shaped auricles alter the angle between the leaf and stalk, which is a key trait in crop plant architecture. As planting density increased, a small leaf angle (LA) was typically selected to promote crop light capture efficiency and yield. In the present study, we characterized two paralogous INDETERMINATE DOMAIN (IDD) genes, ZmIDD14 and ZmIDD15, which contain the Cys2-His2 zinc finger domain and function redundantly to regulate auricle development and LA in maize. Loss-of-function mutants showed decreased LA by reducing adaxial sclerenchyma thickness and increasing the colourless cell layers. In addition, the idd14;idd15 double mutant exhibited asymmetrically smaller auricles, which might cause by a failed maintenance of symmetric expression of the key auricle size controlling gene, LIGULELESS(LG1). The transcripts of ZmIDD14 and ZmIDD15 enriched in the ligular region, where LG1 was highly expressed, and both proteins physically interacted with ZmILI1 to promote LG1 transcription. Notably, the idd14;idd15 enhanced the grain yield of hybrids under high planting densities by shaping the plant architecture with a smaller LA. These findings demonstrate the functions of ZmIDD14 and ZmIDD15 in controlling the abaxial/adaxial development of sclerenchyma in the midrib and polar development along the medial-lateral axes of auricles and provide an available tool for high-density and high-yield breeding in maize.

6.
Liver Int ; 2024 May 22.
Article in English | MEDLINE | ID: mdl-38775078

ABSTRACT

BACKGROUND AND AIMS: The International AIH Pathology Group (IAIH-PG) put forward the new histological criteria of autoimmune hepatitis (AIH) in 2022, which have not undergone adequate verification. In this study, we verified the applicability of the new histological criteria in the population of Chinese patients with chronic liver disease, comparing it with the simplified criteria. METHODS: The gold standard for diagnosis in all patients was based on histological findings, combined with clinical manifestations and laboratory tests and determined after a follow-up period of at least 3 years. A total of 640 patients with various chronic liver diseases from multiple centres underwent scoring using the new histological criteria and the simplified criteria, comparing their diagnostic performance. RESULTS: In this study, the new histological criteria showed a sensitivity of 73.6% and 100% for likely and possible AIH, with specificities of 100% and 69.0% respectively. The coincidence rates of possible AIH for the new histological criteria, simplified histological criteria and simplified score were 81.7%, 72.8% and 69.7% respectively. For likely AIH, the rates were 89.2%, 75.9% and 65.6% respectively. Based on the new histological criteria, all patients with AIH were correctly diagnosed. Specifically, 73.6% were diagnosed with likely AIH and 26.4% were possible AIH. Additionally, the simplified histological criteria achieved a diagnosis rate of 98.6% for AIH, while the simplified score could only diagnose 53.8% of AIH. CONCLUSIONS: Compared with the simplified score and simplified histological criteria, the sensitivity and specificity of the new histological criteria for AIH were significantly improved. The results indicate that the new histological criteria exhibit high sensitivity and specificity for diagnosing AIH in China.

7.
BMC Med Imaging ; 24(1): 39, 2024 Feb 09.
Article in English | MEDLINE | ID: mdl-38336622

ABSTRACT

BACKGROUND: Coronary computed tomography angiography stenosis score (CCTA-SS) is a proposed diagnosis score that considers the plaque characteristics, myocardial function, and the diameter reduction rate of the lesions. This study aimed to evaluate the diagnostic performance of the CCTA-SS in seeking coronary artery disease (CAD). METHODS: The 228 patients with suspected CAD who underwent CCTA and invasive coronary angiography (ICA) procedures were under examination. The diagnostic performance was evaluated with the receiver operating curve (ROC) for CCTA-SS in detecting CAD (defined as a diameter reduction of ≥ 50%) and severe CAD (defined as a diameter reduction of ≥ 70%). RESULTS: The area under ROC (AUC) of CCTA-SS was 0.909 (95% CI: 0.864-0.943), which was significantly higher than that of CCTA (AUC: 0.826; 95% CI: 0.771-0.873; P = 0.0352) in diagnosing of CAD with a threshold of 50%. The optimal cutoff point of CCTA-SS was 51% with a sensitivity of 90.66%, specificity of 95.65%, positive predictive value of 98.80%, negative predictive value of 72.13%, and accuracy of 91.67%, whereas the optimal cutoff point of CCTA was 55%, and the corresponding values were 87.36%, 93.48%, 98.15%, 65.15%, and 88.60%, respectively. With a threshold of 70%, the performance of CCTA-SS with an AUC of 0.927 (95% CI: 0.885-0.957) was significantly higher than that of CCTA with an AUC of 0.521 (95% CI: 0.454-0.587) (P < 0.0001). CONCLUSIONS: CCTA-SS significantly improved the diagnostic accuracy of coronary stenosis, including CAD and severe CAD, compared with CCTA.


Subject(s)
Coronary Artery Disease , Coronary Stenosis , Humans , Computed Tomography Angiography/methods , Constriction, Pathologic , Coronary Stenosis/diagnostic imaging , Tomography, X-Ray Computed/methods , Coronary Angiography/methods , Predictive Value of Tests
8.
Article in English | MEDLINE | ID: mdl-38710642

ABSTRACT

BACKGROUND: Asian carps, a popular freshwater fish globally, are valued for their flavor and serve as a crucial protein source, especially for infants. However, grass carp parvalbumin is highly allergenic, surpassing the allergenicity of fish like salmon and cod. The allergenic potential of parvalbumin in other Asian carps remains unknown, underscoring the need for allergen identification to improve the precision of fish allergy diagnosis and treatment. OBJECTIVE: To identify all parvalbumin homologs in Asian carps and investigate the role of gene divergence in allergenic homolog formation. METHODS: Three annotated genomes of Asian carp, including grass carp, black carp and bighead carp, were constructed using a hybrid assembly approach. Through sequence homology at the genomic level, all the homologs of major fish allergens were identified. Bioinformatics tools were then employed to reveal the gene structures, expression levels, and protein conformations of parvalbumin. RESULTS: Grass carp genome analysis showed nine parvalbumin homologs, with Cid_PV2 most similar to Cten i 1. Bighead and black carp genomes had ten homologs, including potentially allergenic Mpi_PV7 and Hno_PV7. Tissue-specific expression patterns revealed alternative usage of parvalbumin homologs. Gene duplication events expanded parvalbumin copies in bony fish, with two gene clusters identified in Asian carp genomes. CONCLUSION: All the homologs of Asian carps' parvalbumin were accurately identified and gene divergence contributed to the formation of allergenic homologs. Together with a comprehensive gene sequence profile of carps' parvalbumin, those could be applied to achieve a more precise clinical diagnostic test.

9.
Mol Biol Evol ; 39(5)2022 05 03.
Article in English | MEDLINE | ID: mdl-35535514

ABSTRACT

Highly diversified astigmatic mites comprise many medically important human household pests such as house dust mites causing ∼1-2% of all allergic diseases globally; however, their evolutionary origin and diverse lifestyles including reversible parasitism have not been illustrated at the genomic level, which hampers allergy prevention and our exploration of these household pests. Using six high-quality assembled and annotated genomes, this study not only refuted the monophyly of mites and ticks, but also thoroughly explored the divergence of Acariformes and the diversification of astigmatic mites. In monophyletic Acariformes, Prostigmata known as notorious plant pests first evolved, and then rapidly evolving Astigmata diverged from soil oribatid mites. Within astigmatic mites, a wide range of gene families rapidly expanded via tandem gene duplications, including ionotropic glutamate receptors, triacylglycerol lipases, serine proteases and UDP glucuronosyltransferases. Gene diversification after tandem duplications provides many genetic resources for adaptation to sensing environmental signals, digestion, and detoxification in rapidly changing household environments. Many gene decay events only occurred in the skin-burrowing parasitic mite Sarcoptes scabiei. Throughout the evolution of Acariformes, massive horizontal gene transfer events occurred in gene families such as UDP glucuronosyltransferases and several important fungal cell wall lytic enzymes, which enable detoxification and digestive functions and provide perfect drug targets for pest control. This comparative study sheds light on the divergent evolution and quick adaptation to human household environments of astigmatic mites and provides insights into the genetic adaptations and even control of human household pests.


Subject(s)
Adaptation, Physiological , Genomics , Adaptation, Physiological/genetics , Genome , Humans , Uridine Diphosphate
10.
BMC Med ; 21(1): 461, 2023 11 23.
Article in English | MEDLINE | ID: mdl-37996906

ABSTRACT

BACKGROUND: High-power short-duration (HPSD) ablation strategy has emerged as a popular approach for treating atrial fibrillation (AF), with shorter ablation time. The utilized Smart Touch Surround Flow (STSF) catheter, with 56 holes around the electrode, lowers electrode-tissue temperature and thrombus risk. Thus, we conducted this prospective, randomized study to investigate if the HPSD strategy with STSF catheter in AF ablation procedures reduces the silent cerebral embolism (SCE) risk compared to the conventional approach with the Smart Touch (ST) catheter. METHODS: From June 2020 to September 2021, 100 AF patients were randomized 1:1 to the HPSD group using the STSF catheter (power set at 50 W) or the conventional group using the ST catheter (power set at 30 to 35 W). Pulmonary vein isolation was performed in all patients, with additional lesions at operator's discretion. High-resolution cerebral diffusion-weighted magnetic resonance imaging (hDWI) with slice thickness of 1 mm was performed before and 24-72 h after ablation. The incidence of new periprocedural SCE was defined as the primary outcome. Cognitive performance was assessed using the Montreal Cognitive Assessment (MoCA) test. RESULTS: All enrolled AF patients (median age 63, 60% male, 59% paroxysmal AF) underwent successful ablation. Post-procedural hDWI identified 106 lesions in 42 enrolled patients (42%), with 55 lesions in 22 patients (44%) in the HPSD group and 51 lesions in 20 patients (40%) in the conventional group (p = 0.685). No significant differences were observed between two groups regarding the average number of lesions (p = 0.751), maximum lesion diameter (p = 0.405), and total lesion volume per patient (p = 0.669). Persistent AF and CHA2DS2-VASc score were identified as SCE determinants during AF ablation procedure by multivariable regression analysis. No significant differences in MoCA scores were observed between patients with SCE and those without, both immediately post-procedure (p = 0.572) and at the 3-month follow-up (p = 0.743). CONCLUSIONS: Involving a small sample size of 100 AF patients, this study reveals a similar incidence of SCE in AF ablation procedures, comparing the HPSD strategy using the STSF catheter to the conventional approach with the ST catheter. TRIAL REGISTRATION: Clinicaltrials.gov: NCT04408716. AF = Atrial fibrillation, DWI = Diffusion-weighted magnetic resonance imaging, HPSD = High-power short-duration, ST = Smart Touch, STSF = Smart Touch Surround Flow.


Subject(s)
Ablation Techniques , Atrial Fibrillation , Catheter Ablation , Intracranial Embolism , Humans , Male , Middle Aged , Female , Atrial Fibrillation/epidemiology , Atrial Fibrillation/surgery , Atrial Fibrillation/complications , Prospective Studies , Intracranial Embolism/diagnostic imaging , Intracranial Embolism/epidemiology , Intracranial Embolism/prevention & control , Incidence , Ablation Techniques/adverse effects , Treatment Outcome , Catheter Ablation/adverse effects , Catheter Ablation/methods , Recurrence
11.
PLoS Pathog ; 17(7): e1009752, 2021 07.
Article in English | MEDLINE | ID: mdl-34288976

ABSTRACT

Highly immunogenic exotoxins are used as carrier proteins because they efficiently improve the immunogenicity of polysaccharides. However, their efficiency with protein antigens remains unclear. In the current study, the candidate antigen PA0833 from Pseudomonas aeruginosa was fused to the α-hemolysin mutant HlaH35A from Staphylococcus aureus to form a HlaH35A-PA0833 fusion protein (HPF). Immunization with HPF resulted in increased PA0833-specific antibody titers, higher protective efficacy, and decreased bacterial burden and pro-inflammatory cytokine secretion compared with PA0833 immunization alone. Using fluorescently labeled antigens to track antigen uptake and delivery, we found that HlaH35A fusion significantly improved antigen uptake in injected muscles and antigen delivery to draining lymph nodes. Both in vivo and in vitro studies demonstrated that the increased antigen uptake after immunization with HPF was mainly due to monocyte- and macrophage-dependent macropinocytosis, which was probably the result of HPF binding to ADAM10, the Hla host receptor. Furthermore, a transcriptome analysis showed that several immune signaling pathways were activated by HPF, shedding light on the mechanism whereby HlaH35A fusion improves immunogenicity. Finally, the improvement in immunogenicity by HlaH35A fusion was also confirmed with two other antigens, GlnH from Klebsiella pneumoniae and the model antigen OVA, indicating that HlaH35A could serve as a universal carrier protein to improve the immunogenicity of protein antigens.


Subject(s)
Antigens, Bacterial/immunology , Hemolysin Proteins/immunology , Vaccines/immunology , A549 Cells , Animals , Exotoxins/immunology , Female , Humans , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , RAW 264.7 Cells , Recombinant Fusion Proteins/immunology
12.
Allergy ; 78(4): 1088-1103, 2023 04.
Article in English | MEDLINE | ID: mdl-36153808

ABSTRACT

BACKGROUND: One of the most common cockroach types in urban areas, the American cockroach (Periplaneta americana), has been reported to impose an increased risk of allergies and asthma. Limited groups of allergens (Per a 1-13) have been identified in this species due to the lack of genome-related information. METHODS: To expand the allergen profile of P. americana, genomic, transcriptomic, and proteomic approaches were applied. With the support of a high-quality genome assembled using nanopore, Illumina, and Hi-C sequencing techniques, potential allergens were identified based on protein homology. Then, using enzyme-linked immunosorbent assay, selected allergens were tested in Thai patients allergic to P. americana. RESULTS: A chromosomal-level genome of P. americana (3.06 Gb) has been assembled with 94.6% BUSCO completeness, and its contiguity has been significantly improved (N50 = 151 Mb). A comprehensive allergen profile has been characterized, with seven novel groups of allergens, including enolase (Per a 14), cytochrome C (Per a 15), cofilin (Per a 16), alpha-tubulin (Per a 17), cyclophilin (Per a 18), porin3 (Per a 19), and peroxiredoxin-6 (Per a 20), showing IgE sensitivity in enzyme-linked immunosorbent assay. A new isoallergen of tropomyosin (Per a 7.02) and multiple potential isoallergens of Per a 5 were revealed using bioinformatics and proteomic approaches. Additionally, comparative analysis of P. americana with the closely related Blattodea species revealed the possibility of cross-reaction. CONCLUSION: The high-quality genome and proteome of P. americana are beneficial in studying cockroach allergens at the molecular level. Seven novel allergen groups and one isoallergen in Per a 7 were identified.


Subject(s)
Cockroaches , Hypersensitivity , Periplaneta , Animals , Humans , Proteomics , Allergens/genetics , Hypersensitivity/genetics
13.
BMC Gastroenterol ; 23(1): 282, 2023 Aug 14.
Article in English | MEDLINE | ID: mdl-37580680

ABSTRACT

BACKGROUND: Complications and diagnostic efficiency for liver biopsy are main concerns for clinicians. This study aimed to assess the safety and efficacy of transjugular liver biopsy (TJLB) compared with percutaneous liver biopsy (PLB) when patients had equal level of liver function and number of passes, using propensity score matching (PSM). METHODS: The clinical and pathological data of patients who received TJLB or PLB between January 2012 and October 2022 were collected. Matching factors included age, gender, cirrhosis, portal hypertension, liver function, creatinine, number of passes, hemodialysis, history of anti-coagulation and anti-platelet, and comorbidities. Coagulation indexes were not considered as matching factors due to different indications of the two techniques. RESULTS: 2711 PLBs and 30 TJLBs were evaluated. By PSM, 75 patients (50 PLBs, 25 TJLBs) were matched. The complication rates for TJLB and PLB were 4.0% (1/25) and 10.0% (5/50) (P > 0.05). Two PLBs had hepatic hemorrhage, one of which required only close monitoring (Grade 1) and the other needed hemostasis and rehydration therapy (Grade 2). The other 3 cases presented with mild abdominal pain (Grade 1). And only one TJLB presented with mild pain. The median number of complete portal tracts were 6.0 and 10.0 for TJLBs and PLBs (P < 0.05). Moreover, the median length of sample for TJLBs and PLBs were 10.0 and 16.5 mm (P < 0.05). The diagnostic efficiency of hepatopathy of unknown etiology of TJLB versus PLB groups before and after matching were 96.4% vs. 94.1% and 95.7% vs. 93.2%, respectively (P > 0.05). CONCLUSION: TJLB is an effective invasive diagnostic procedure that expands indications for liver biopsy with reliable diagnostic quality.


Subject(s)
Hypertension, Portal , Liver Diseases , Humans , Jugular Veins/pathology , Liver/pathology , Biopsy/adverse effects , Biopsy/methods , Liver Diseases/pathology , Hypertension, Portal/etiology , Hypertension, Portal/pathology , Abdominal Pain/etiology
14.
Nucleic Acids Res ; 49(22): 13045-13061, 2021 12 16.
Article in English | MEDLINE | ID: mdl-34871455

ABSTRACT

Dnmt2, a member of the DNA methyltransferase superfamily, catalyzes the formation of 5-methylcytosine at position 38 in the anticodon loop of tRNAs. Dnmt2 regulates many cellular biological processes, especially the production of tRNA-derived fragments and intergenerational transmission of paternal metabolic disorders to offspring. Moreover, Dnmt2 is closely related to human cancers. The tRNA substrates of mammalian Dnmt2s are mainly detected using bisulfite sequencing; however, we lack supporting biochemical data concerning their substrate specificity or recognition mechanism. Here, we deciphered the tRNA substrates of human DNMT2 (hDNMT2) as tRNAAsp(GUC), tRNAGly(GCC) and tRNAVal(AAC). Intriguingly, for tRNAAsp(GUC) and tRNAGly(GCC), G34 is the discriminator element; whereas for tRNAVal(AAC), the inosine modification at position 34 (I34), which is formed by the ADAT2/3 complex, is the prerequisite for hDNMT2 recognition. We showed that the C32U33(G/I)34N35 (C/U)36A37C38 motif in the anticodon loop, U11:A24 in the D stem, and the correct size of the variable loop are required for Dnmt2 recognition of substrate tRNAs. Furthermore, mammalian Dnmt2s possess a conserved tRNA recognition mechanism.


Subject(s)
5-Methylcytosine/metabolism , Anticodon/metabolism , DNA (Cytosine-5-)-Methyltransferases/metabolism , RNA, Transfer/metabolism , Adenosine Deaminase/genetics , Adenosine Deaminase/metabolism , Animals , Anticodon/genetics , Base Sequence , DNA (Cytosine-5-)-Methyltransferases/chemistry , DNA (Cytosine-5-)-Methyltransferases/genetics , HEK293 Cells , HeLa Cells , Humans , Inosine/metabolism , Mice , Models, Molecular , NIH 3T3 Cells , Nucleic Acid Conformation , Protein Binding , RNA, Transfer/chemistry , RNA, Transfer/genetics , RNA, Transfer, Asp/chemistry , RNA, Transfer, Asp/genetics , RNA, Transfer, Asp/metabolism , RNA, Transfer, Gly/chemistry , RNA, Transfer, Gly/genetics , RNA, Transfer, Gly/metabolism , RNA, Transfer, Val/chemistry , RNA, Transfer, Val/genetics , RNA, Transfer, Val/metabolism , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , Substrate Specificity
15.
Nucleic Acids Res ; 49(20): 11900-11919, 2021 11 18.
Article in English | MEDLINE | ID: mdl-34669960

ABSTRACT

Post-transcriptional modifications affect tRNA biology and are closely associated with human diseases. However, progress on the functional analysis of tRNA modifications in metazoans has been slow because of the difficulty in identifying modifying enzymes. For example, the biogenesis and function of the prevalent N2-methylguanosine (m2G) at the sixth position of tRNAs in eukaryotes has long remained enigmatic. Herein, using a reverse genetics approach coupled with RNA-mass spectrometry, we identified that THUMP domain-containing protein 3 (THUMPD3) is responsible for tRNA: m2G6 formation in human cells. However, THUMPD3 alone could not modify tRNAs. Instead, multifunctional methyltransferase subunit TRM112-like protein (TRMT112) interacts with THUMPD3 to activate its methyltransferase activity. In the in vitro enzymatic assay system, THUMPD3-TRMT112 could methylate all the 26 tested G6-containing human cytoplasmic tRNAs by recognizing the characteristic 3'-CCA of mature tRNAs. We also showed that m2G7 of tRNATrp was introduced by THUMPD3-TRMT112. Furthermore, THUMPD3 is widely expressed in mouse tissues, with an extremely high level in the testis. THUMPD3-knockout cells exhibited impaired global protein synthesis and reduced growth. Our data highlight the significance of the tRNA: m2G6/7 modification and pave a way for further studies of the role of m2G in sperm tRNA derived fragments.


Subject(s)
Methyltransferases/metabolism , RNA, Transfer/metabolism , RNA-Binding Proteins/metabolism , tRNA Methyltransferases/metabolism , HEK293 Cells , HeLa Cells , Humans , Methylation , Methyltransferases/genetics , RNA Processing, Post-Transcriptional , RNA-Binding Proteins/genetics , Substrate Specificity , tRNA Methyltransferases/genetics
16.
Int Orthop ; 47(3): 763-771, 2023 03.
Article in English | MEDLINE | ID: mdl-36646902

ABSTRACT

PURPOSES: Temporary hemiepiphysiodesis (TH) using eight-plates is one of the most frequently performed surgeries for correcting angular deformities of the lower extremities in adolescents. Rarely have studies examined children with X-linked hypophosphataemic rickets (X-LHPR) treated with TH using eight-plates. This study was conducted to investigate the efficacy, the endpoint, and the complications of TH using eight-plates to correct angular deformities of the lower extremities in skeletally immature children. METHODS: We reviewed a total of 26 children (86 physes, 52 knees) with X-LHPR (mean age of 6.2 years, range from 2 to 13 years) who underwent TH using eight-plate to correct angular deformities of the lower extremities. Radiographs and clinical records of these patients were evaluated for demographic data and related clinical factors. RESULTS: The average correction of the mechanical lateral distal femoral angle (mLDFA) was 11.7 ± 8.7° (range from 1.0 to 29.7°), and the average correction of the mechanical medial proximal tibial angle (mMPTA) was 8.4 ± 5.0° (range from 0.3 to 16.7°). The mean deformity correction time was 22.7 months (range from 7 to 60 months), and the mean follow-up after eight-plate removal was 43.9 months (range from 24 to 101 months). Overall, 76.9% (20/26 patients) of the angular deformities of the knee were completely corrected and 15.4% (4/26) of the patients received osteotomy surgery. The femoral correction velocity (0.9° per month) was significantly higher than the proximal tibial (0.6° per month) (p = 0.02). The correction velocity of the mLDFA and mMPTA with the TH procedure was faster than that in the absence of intervention (0.9° vs. 0.2°, 0.7° vs. 0.4° per month, p < 0.05). The correction velocity of the mLDFA (1.2° vs. 0.5° per month, [Formula: see text]) and mMPTA (0.7° vs. 0.5° per month, p = 0.04) of patients whose age ≤ five years old was faster than that of patients whose age > five years old. A total of 69.2% (18/26) patients experienced one TH procedure using eight-plates only. Two patients had screw loosening (2/26, 7.7%). One patient (1/26, 3.8%) had a rebound phenomenon after the removal of eight-plate and had the TH procedure again. There was no breakage, infection, physis preclosure, or limited range of movement found in the follow-up. CONCLUSION: TH using eight-plates is a safe and effective procedure with a relatively low incidence of complication and rebound, and it could be used as part of a streamlined treatment for younger X-LHPR patients with resistant or progressive lower limb deformity despite optimal medical treatment. Early intervention can achieve better results.


Subject(s)
Familial Hypophosphatemic Rickets , Adolescent , Humans , Child , Child, Preschool , Familial Hypophosphatemic Rickets/surgery , Lower Extremity/surgery , Tibia/surgery , Knee Joint/diagnostic imaging , Knee Joint/surgery , Knee Joint/abnormalities , Growth Plate/surgery , Bone Plates , Retrospective Studies
17.
BMC Gastroenterol ; 22(1): 443, 2022 Nov 02.
Article in English | MEDLINE | ID: mdl-36324070

ABSTRACT

BACKGROUND: Aberrant cytokeratin 7 expression by hepatocytes (CK7+Hs) is the hallmark characteristic of cholestasis diseases, especially in ductopenia diseases such as primary biliary cholangitis (PBC). This study attempted to evaluate the differences and relationships between the clinical and histological features of aberrant cytokeratin 7 (CK7) expression by hepatocytes in PBC patients. METHODS: The clinicopathological data of patients diagnosed with PBC at the Second Hospital of Nanjing between January 2016 and September 2018 were analysed with SPSS 20.0. RESULTS: Eighty-nine PBC patients who underwent liver biopsy were enrolled in this study, and 15, 29 and 45 patients had aberrant CK7 expression by hepatocytes (CK7+Hs (2 +), CK7+Hs (1 +), and CK7-Hs, respectively). There were significant differences in TB, DB, ALP, TA, IgM, interface activity, and ductopenia grade between patients with CK7-Hs and CK7+Hs (2 +) (P < 0.05). The ductopenia grade was also significantly different between patients with CK7+Hs (2 +) and CK7+Hs (1 +) according to sex (P < 0.05). Upon merging the data of CK7+Hs (2 +) and CK7+Hs (1 +) into CK7+Hs, we found significant differences in AMA, AMA-M2, anti-gp210, TB, DB, ALP, TA, IgM, fibrosis, and ductopenia grade between CK7+Hs and CK7-Hs (P < 0.05). The odds ratios (ORs) (and 95% confidence intervals (CIs)) of CK7+Hs according to anti-gp210, ductopenia grade, and interface activity were 6.413 (95% CI 1.363-30.162), 4.145 (95% CI 1.898-9.052) and 3.247 (95% CI 1.556-6.775), respectively (P < 0.05). Spearman's rank correlation according to interface activity and ductopenia grade in patients with CK7+Hs (2 + , 1 + , 0) was r = 0.359 (P = 0.001) and r = 0.396 (P < 0.001), respectively. CONCLUSION: CK7+Hs serves as a cholestasis index of PBC and are associated with the ductopenia grade and interface activity. Aberrant cytokeratin 7 expression by hepatocytes can predict the ductopenia grade in primary biliary cholangitis.


Subject(s)
Cholangitis , Cholestasis , Liver Cirrhosis, Biliary , Humans , Keratin-7/metabolism , Liver Cirrhosis, Biliary/diagnosis , Hepatocytes/metabolism , Cholestasis/pathology , Immunoglobulin M , Cholangitis/pathology
18.
Acta Pharmacol Sin ; 43(10): 2596-2608, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35241769

ABSTRACT

Platelet hyperactivity is essential for thrombus formation in coronary artery diseases (CAD). Dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) in patients with cystic fibrosis elevates intracellular Cl- levels ([Cl-]i) and enhanced platelet hyperactivity. In this study, we explored whether alteration of [Cl-]i has a pathological role in regulating platelet hyperactivity and arterial thrombosis formation. CFTR expression was significantly decreased, while [Cl-]i was increased in platelets from CAD patients. In a FeCl3-induced mouse mesenteric arteriole thrombosis model, platelet-specific Cftr-knockout and/or pre-administration of ion channel inhibitor CFTRinh-172 increased platelet [Cl-]i, which accelerated thrombus formation, enhanced platelet aggregation and ATP release, and increased P2Y12 and PAR4 expression in platelets. Conversely, Cftr-overexpressing platelets resulted in subnormal [Cl-]i, thereby decreasing thrombosis formation. Our results showed that clamping [Cl-]i at high levels or Cftr deficiency-induced [Cl-]i increasement dramatically augmented phosphorylation (Ser422) of serum and glucocorticoid-regulated kinase (SGK1), subsequently upregulated P2Y12 and PAR4 expression via NF-κB signaling. Constitutively active mutant S422D SGK1 markedly increased P2Y12 and PAR4 expression. The specific SGK1 inhibitor GSK-650394 decreased platelet aggregation in wildtype and platelet-specific Cftr knockout mice, and platelet SGK1 phosphorylation was observed in line with increased [Cl-]i and decreased CFTR expression in CAD patients. Co-transfection of S422D SGK1 and adenovirus-induced CFTR overexpression in MEG-01 cells restored platelet activation signaling cascade. Our results suggest that [Cl-]i is a novel positive regulator of platelet activation and arterial thrombus formation via the activation of a [Cl-]i-sensitive SGK1 signaling pathway. Therefore, [Cl-]i in platelets is a novel potential biomarker for platelet hyperactivity, and CFTR may be a potential therapeutic target for platelet activation in CAD.


Subject(s)
Cystic Fibrosis Transmembrane Conductance Regulator , Immediate-Early Proteins , Thrombosis , Adenosine Triphosphate/metabolism , Animals , Blood Platelets/metabolism , Chlorides/metabolism , Cystic Fibrosis Transmembrane Conductance Regulator/antagonists & inhibitors , Cystic Fibrosis Transmembrane Conductance Regulator/metabolism , Immediate-Early Proteins/metabolism , Mice , Mice, Knockout , NF-kappa B/metabolism , Protein Serine-Threonine Kinases/metabolism , Signal Transduction , Thrombosis/metabolism
19.
Eur Respir J ; 57(1)2021 01.
Article in English | MEDLINE | ID: mdl-32817257

ABSTRACT

BACKGROUND AND AIMS: Neutrophilic inflammation is a hallmark of some specific asthma phenotypes; its aetiology is not yet fully understood. House dust mite (HDM) is the most common factor in the pathogenesis of airway inflammation. This study aims to elucidate the role of cross-antibodies against HDM-derived factors in the development of neutrophilic inflammation in the airway. METHODS: Blood samples were collected from asthma patients with chronic neutrophilic asthma for analysis of HDM-specific cross-reactive antibodies. The role of an antibody against HDM-derived enolase (EnoAb) in the impairment of airway epithelial barrier function and induction of airway inflammation was assessed in a cell culture model and an animal model. RESULTS: High similarity (72%) of the enolase gene sequences was identified between HDM and human. Serum EnoAb was detected in patients with chronic neutrophilic asthma. The EnoAb bound to airway epithelial cells to form complexes with enolase, which activated complement, impaired airway epithelial barrier functions and induced neutrophilic inflammation in the airway tissues. CONCLUSIONS: HDM-derived enolase can induce specific cross-antibodies in humans, which induce neutrophilic inflammation in the airway.


Subject(s)
Asthma , Phosphopyruvate Hydratase , Animals , Antibodies , Cross Reactions , Disease Models, Animal , Dust , Humans , Inflammation , Neutrophils , Pyroglyphidae
20.
New Phytol ; 231(4): 1644-1657, 2021 08.
Article in English | MEDLINE | ID: mdl-33914919

ABSTRACT

Understanding the mechanisms of iron trafficking in plants is key to enhancing the nutritional quality of crops. Because it is difficult to image iron in transit, we currently have an incomplete picture of the route(s) of iron translocation in developing seeds and how the tissue-specific distribution is established. We have used a novel approach, combining iron-57 (57 Fe) isotope labelling and nanoscale secondary ion mass spectrometry (NanoSIMS), to visualize iron translocation between tissues and within cells in immature wheat grain, Triticum aestivum. This enabled us to track the main route of iron transport from maternal tissues to the embryo through the different cell types. Further evidence for this route was provided by genetically diverting iron into storage vacuoles, with confirmation provided by histological staining and transmission electron microscopy energy dispersive X-ray spectroscopy (TEM-EDS). Almost all iron in both control and transgenic grains was found in intracellular bodies, indicating symplastic rather than apoplastic transport. Furthermore, a new type of iron body, highly enriched in 57 Fe, was observed in aleurone cells and may represent iron being delivered to phytate globoids. Correlation of the 57 Fe enrichment profiles obtained by NanoSIMS with tissue-specific gene expression provides an updated model of iron homeostasis in cereal grains with relevance for future biofortification strategies.


Subject(s)
Iron , Triticum , Edible Grain , Phytic Acid , Seeds
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