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Biomedical subjects

Yan Li

Publications and source records attributed to Yan Li.

At least 37 records · Page 2Linked to original sources

Mitochondrial dysfunction in the pathogenesis of intervertebral disc herniation: a mitochondrial related genome-wide Mendelian randomization analysis.

BACKGROUND: As a degenerative disease, the pathophysiology of intervertebral disc herniation (IDH) closely related to mitochondrial dysfunction. However, the specific molecular mechanisms involved have yet to be precisely established. METHODS: Here, we employed a two-sample, two-step Mendelian Randomization (MR) approach, along with summary-Data-Based MR, genetic colocalization, full phenomenon association analysis, and GO and KEGG enrichment analysis to investigate the genetical effects of mitochondrial dysfunction on IDH. RESULTS: From the intercross between mitochondrial-related genes and eQTLGen genes, we obtained seven genes (DMPK, EHHADH, SLC25A16, ME3, METTL17, TUFM, NDUFA13) with strong causal association with disc herniation. By SMR and genetic colocalization analysis, we further identify five key genes (EHHADH, METTL17, TUFM, NDUFA13, DMPK) as the direct causal tartgeted genes with no heterogeneity and pleiotropy in the SNPs of the genes. Full phenomenon Mendelian randomization was performed to determine possible side effects of the 5 targeting genes. Finally, we validated the expressions of key genes in the degenerative intervertebral discs tissues by qRT-PCR and double-immunofluorescence examinations, and the results were consistent with the MR analysis. CONCLUSIONS: Our study provided genetic support for the relationship between mitochondrial related genes and IDH, implicating potential therapeutic targets for future development. However, more basic experiments need to be finished to validate the role of key genes in the development of IDH.

Intervertebral Disc Displacement

Clinical Application of Long-Read Sequencing for FMR1 Gene Mutation Detection in Populations From Shandong, China.

BACKGROUND: Fragile X syndrome (FXS) is a common inherited intellectual disability. In this study, long-read sequencing was used for the FMR1 gene detection. METHODS: Men with familial inherited intellectual disability and women with indications for FXS screening were defined as high-risk populations and were included in this study along with non-high-risk reproductive-aged women. PCR-capillary electrophoresis was used for preliminary screening of non-high-risk reproductive-aged women, and long-read sequencing was performed on abnormal samples and samples from high-risk populations. Prenatal diagnosis using long-read sequencing was performed for pregnant women in need. RESULTS: The prevalence of mutation in high-risk females was 3.10% (7/226). 3 mutations were detected in male samples, with a mutation ratio of approximately 8.3% (3/36). The three most common CGG repeats were 29, 30, and 36, respectively. Analysis of AGG interruption pattern in 242 samples identified 908 AGG interruptions, involving 67 different patterns. The most frequent AGG interruption pattern was (CGG)9AGG(CGG)9AGG(CGG)9. Furthermore, long-read sequencing was successfully applied for prenatal diagnosis in two pregnant women, and dynamic mutation of CGG repeat was detected within one family. CONCLUSION: Long-read sequencing-based assay cannot only accurately detect CGG repeat and AGG interruption, but also simultaneously identify other abnormalities of the FMR1 gene. Long-read sequencing offers a broader detection scope and better characterization of FXS-related genetic features.

Humans

Identification and prognosis of low office and ambulatory blood pressure in patients with heart failure.

BACKGROUND: Low blood pressure (BP) limits the up-titration of guideline-directed medical therapies (GDMTs) and predicts poor outcomes in heart failure (HF). We assessed the value of ambulatory BP&#xa0;monitoring (ABPM) in detecting&#xa0;low BP and its impact on GDMTs optimization and prognosis in HF. METHODS: In&#xa0;491 HF patients initiating GDMTs from the Risk Evaluation and Management in Heart Failure (REM-HF) study since April 2018 to December 2022, ABPM was measured&#xa0;in addition to office BP. Participants were classified as sustained low systolic BP (SBP) (24-hour and office SBP < 120&#x2009;mmHg), masked low SBP (24-hour SBP < 120&#x2009;mmHg, office SBP &#x2265; 120&#x2009;mmHg), and no low SBP. The primary outcome was a composite of all-cause mortality and HF rehospitalization. GDMTs target dose achievement was assessed at 3 months. Logistic regression and&#xa0;Cox regression models were used to assess GDMTs optimization and outcomes across SBP groups. RESULTS: Sustained, masked, and no low SBP were observed in 25.3%, 30.8%, and 44.0% of patients, respectively. Both sustained (OR 2.36, 95%CI 1.25-4.47) and masked low SBP (OR 2.32, 95%CI 1.11-4.87) groups were associated with lower likelihood of achieving GDMTs target doses. Over a median 21-month follow-up, all-cause mortality and HF rehospitalization rates were higher in sustained (HR 2.45, 95% CI 1.56-3.86) and masked low SBP (HR 1.68, 95% CI 1.08-2.62) groups. No difference was found in the target dose achievement and outcomes between the two low SBP groups. CONCLUSION: Sustained and masked low SBP were common in HF and both associated with GDMTs intolerance and adverse outcomes.

Humans

Morning-to-evening change in home blood pressure as a predictor of fatal and nonfatal cardiovascular events.

OBJECTIVE: We investigated the morning-to-evening changes in home blood pressure (BP) in relation to the risk of fatal and nonfatal cardiovascular events. METHOD: The study participants (&#x2265;18&#x200a;years of age) were outpatients enrolled in the China Nationwide Ambulatory and Home Blood Pressure Registry. Home BP was measured at baseline for 7 consecutive days in the morning and evening five times consecutively, of which the first three readings were averaged for analysis. The morning-to-evening changes in home BP were calculated by subtracting the BP values in the morning from that in the evening. RESULT: During a mean (&#xb1;SD) follow-up of 4.9 (&#xb1;2.6) years, 184 cardiovascular events occurred among the 5057 study participants. The mean morning-to-evening change in home SBP/DBP&#xa0;was -2.2&#x200a;&#xb1;&#x200a;8.1/-2.5&#x200a;&#xb1;&#x200a;4.5&#x200a;mmHg. The age and sex-standardized incident rate was highest in quartile 1 of the changes in both SBP and DBP for fatal and nonfatal cardiovascular events, stroke (log-rank test, P &#x200a;<&#x200a;0.001). After adjustment for confounding factors, including the mean of morning and evening BP, the hazard ratios for patients in quartile 1 of the morning-to-evening change relative to the overall study participants reached statistical significance for SBP [1.39, 95% confidence interval (95% CI) 1.03-1.88] and DBP (1.59, 95% CI: 1.17-2.15) in relation to fatal and nonfatal stroke, and for diastolic BP in relation to fatal and nonfatal cardiovascular events (1.42, 95% CI: 1.13-1.77). CONCLUSION: In outpatients, a mild to moderate BP drop from morning to evening was associated with a significantly higher risk of all cardiovascular events, especially stroke.

Humans

Dissemination of antimicrobial resistance in Klebsiella spp. from urban aquatic environments: a multi-country genomic perspective.

INTRODUCTION: Antibiotic resistance, particularly carbapenem-resistant Klebsiella pneumoniae (CRKP), poses significant clinical and environmental threats, especially in urban aquatic ecosystems and hospital wastewaters. OBJECTIVES: This study aims to analyze the epidemiological and genomic features of CRKP isolates in urban aquatic environments and evaluate their public health and environmental impacts. METHODS AND RESULTS: Water samples were collected from 113 rivers and 3 hospitals in China, Sri Lanka, and Nepal to isolate carbapenem-resistant Klebsiella spp. isolates. Antimicrobial susceptibility testing, whole-genome sequencing, and bioinformatics analyses were performed to characterize resistance phenotypes, antibiotic resistance genes (ARGs), and evolutionary trends. Big data analysis further elucidated the genomic characteristics of CRKP in global water sources, and Galleria mellonella larvae were used to assess virulence. Statistical analysis validated the findings. A total of 192 carbapenem-resistant Klebsiella spp. isolates were identified from urban aquatic ecosystems in China (n&#xa0;=&#xa0;60) and Nepal (n&#xa0;=&#xa0;132), with CRKP (n&#xa0;=&#xa0;161) being the predominant species. All CRKP isolates exhibited a multidrug-resistant phenotype, yet significant differences in resistance profiles and associated ARGs were observed between isolates from the two countries. Nine carbapenem resistance genes (CRGs) were detected, with blaNDM-1 being the most prevalent (57.8&#xa0;%). Correlation analysis revealed a strong association between these CRGs and multiple Inc-type plasmids. Global genomic analysis of CRKP from water sources across eight countries identified ten distinct CRGs across 45 serotypes, with KL64 being the most predominant. Notably, carbapenem-resistant hypervirulent Klebsiella pneumoniae was detected in water samples from Nepal. CONCLUSION: Our findings highlight significant regional disparities in CRKP prevalence and ARG dissemination across urban aquatic environments, with Nepal showing the highest prevalence, particularly in untreated rivers. China exhibited lower prevalence but distinct resistance gene profiles, while no CRKP was detected in Sri Lanka, underscoring the impact of environmental management and healthcare infrastructure on ARG spread.

Humans

Proteomic signature of dementia risk in type 2 diabetes.

INTRODUCTION: Type 2 diabetes (T2D) significantly increases dementia risk, yet the molecular mechanisms underlying this association remain unclear. OBJECTIVES: This study aimed to identify protein signatures that distinguish dementia risk in T2D patients, develop a proteomic prediction model, and elucidate biological pathways connecting T2D and dementia. METHODS: We analyzed 2,920 plasma proteins from 52,958 participants (including 3,292 with T2D) in the UK Biobank Pharma Proteomics Project with a median follow-up of 14.6&#xa0;years. Cox regression models with interaction terms identified T2D-specific protein associations with dementia risk. Machine learning models were developed to predict dementia in T2D patients. Pathway analysis and weighted gene co-expression network analysis identified biological mechanisms linking T2D and dementia. RESULTS: We identified 471 proteins with significant interaction effects between T2D and dementia risk. In non-T2D individuals, elevated levels of neuronal pentraxin receptor (NPTXR, HR&#xa0;=&#xa0;0.74, 95&#xa0;%CI:0.66-0.83) and carbonic anhydrase 14 (CA14, HR&#xa0;=&#xa0;0.67, 95&#xa0;%CI:0.60-0.75) were exclusively associated with decreased dementia risk. Conversely, in T2D patients, elevated rho guanine nucleotide exchange factor 12 (ARHGEF12, HR&#xa0;=&#xa0;1.45, 95&#xa0;%CI:1.10-1.91) was specifically associated with increased dementia risk. A 51-protein model accurately predicted 15-year dementia risk in T2D patients (AUC&#xa0;=&#xa0;0.835, C-index&#xa0;=&#xa0;0.829), outperforming conventional clinical risk scores and maintaining high accuracy for Alzheimer's disease and vascular dementia. Pathway analysis revealed enrichment of IL6-JAK-STAT3 signaling in T2D-related dementia, while dysregulation of fatty acid metabolism was specific to T2D-associated Alzheimer's disease. CONCLUSIONS: This large-scale proteomic analysis identifies specific molecular signatures that differentiate dementia risk in diabetic and non-diabetic populations, with potential applications for early risk stratification and targeted interventions. The identified pathways provide novel insights into the pathophysiological processes connecting T2D and dementia and suggest potential therapeutic targets.

Humans

Genomic and Transcriptomic Landscape of Epstein-Barr Virus-Positive Inflammatory Follicular Dendritic Cell Sarcoma: A Multicenter Study.

Epstein-Barr virus (EBV)-positive inflammatory follicular dendritic cell sarcoma (EBV+ IFDCS) is a rare indolent malignant neoplasm, which occurs almost exclusively in the liver or spleen and may arise from a common EBV-infected mesenchymal cell that differentiates along the follicular or fibroblastic dendritic cell pathway. Despite its rarity, it presents a pressing need for an improved understanding of its genetic underpinnings and potential treatment strategies for recurrent or disseminated cases. To address this, we conducted comprehensive whole-exome sequencing and transcriptome sequencing (mRNA-seq) analyses on 31 and 6 cases of EBV+ IFDCS, respectively, collected from multiple centers in China. We also compared the genetic features of EBV+ IFDCS with those of other EBV-associated malignancies. Our analyses revealed a relatively high somatic mutation rate and widespread copy number variations affecting the major histocompatibility complex-I/II in EBV+ IFDCS. Integrated mutational profiling identified key signaling pathways involved in epigenetic regulation, NF-&#x3ba;B signaling, RTK/RAS/PI(3)K, and the Hippo pathway. Furthermore, we identified several frequently altered genes that could serve as potential therapeutic targets in EBV+ IFDCS. Transcriptomic analysis unveiled significant upregulation of pathways related to virus infection, immune responses, and multiple immune checkpoint genes in EBV+ IFDCS. Comparative analysis demonstrated clear genetic distinctions between EBV+ IFDCS and other EBV-associated tumors. In conclusion, our study provides comprehensive insights into the unique genomic and transcriptomic landscape of EBV+ IFDCS. We have identified multiple genetic alterations that likely contribute to the development and progression of this malignancy. Our results suggest that targeted therapy and immune checkpoint inhibitors may hold promise as potential therapeutic approaches for patients with recurrent or disseminated EBV+ IFDCS.

Humans

Ventricular-arterial coupling is preserved in prematurely born 11-year-old children but calls for life-long prevention of hemodynamic deterioration.

BACKGROUND: Premature birth disrupts the intra-uterine structural and functional maturation of the left ventricle (LV) and arteries. The study investigated the impact of premature birth on ventricular-arterial coupling (VAC), a potential precursor of cardiovascular disease in adulthood. METHODS: This case-control study in Northern Belgium (2011-2016) included 93 extremely-low-birth-weight (ELBW) cases and 87 sex and age-matched term-born controls. Main outcomes included SBP and DBP, central arterial properties, echocardiographic structure and function, and VAC. RESULTS: Compared with controls, cases were shorter by 4.1&#x200a;cm [95% confidence interval (95% CI): 1.3-7.0] and lighter by 4.1&#x200a;kg (95% CI: 1.3-6.9). Cases had higher central SBP/DBP (+7.3/3.0&#x200a;mmHg; 95% CI: 4.7-9.9/1.1-4.8), lower left ventricular end-diastolic and end-systolic dimensions, and 9.2&#x200a;g (95% CI: 3.7-14.6) lower left ventricular mass. Left ventricular volumes and mass correlated with body size without significant between-group differences ( P &#x200a;&#x2265;&#x200a;0.12). Cardiac output was 0.38&#x200a;l/min lower in cases, who also had higher arterial resistance (29.5 vs. 24.4&#x200a;mmHg&#x200a;&#xd7;&#x200a;min/l) and augmentation ratio (1.10 vs. 1.05). The tension-time index was 231&#x200a;mmHg &#xd7; ms (95% CI: 128-335) higher in cases. Ea and Ees were higher in cases (0.40 and 0.65&#x200a;mmHg/ml, respectively), but VAC did not differ between groups ( P &#x200a;=&#x200a;0.48). CONCLUSION: Compensatory mechanisms maintain the anatomical and functional integrity of the cardiovascular system in ELBW youth, but mask their vulnerability to cardiovascular disease in adulthood and necessitate careful follow-up during adolescence.

Humans

Cholesterol Metabolism-related Characteristics Predict Therapeutic Response and Survival in Esophageal Cancer.

INTRODUCTION: Cholesterol homeostasis has been identified as an essential downstream pathway of mutations in TP53. Esophageal cancer is one of the most prevalent malignancies exhibiting the mutation. OBJECTIVES: To explore the significance of cholesterol metabolism-related characteristics in tumor phenotype and treatment outcomes of esophageal cancer. METHODS: We established a cholesterol metabolism-related gene set (CMGs) and performed Lasso-Cox analysis to identify prognostic signatures. Nomogram-based risk scores and clinical stages afterwards were constructed and evaluated. We simultaneously identified two metabolic subtypes based on the distinct features of the CMGs. We annotated the functional and pathway characteristics of differentially expressed genes between the clusters and compared the differences in clinical and immune characteristics. Finally, we assessed the prognostic value of signatures in the GSE53625 and two clinical cohorts using whole-exon sequencing and multiplex immunofluorescence. RESULTS: Our study identified five cholesterol prognosis-related genes (CRGs) that demonstrated superior prognostic efficacy in the training set compared to clinical staging, validated in independent public databases and two clinical cohorts. According to the different expression patterns of the signatures, patients were divided into two subtypes. The C1 group demonstrated poorer overall survival, response to immunotherapy, and downregulation of the p53 pathway. In the immune correlation analysis, we found that the risk score based on 5-signature model was significantly positively correlated with the abundance of suppressive immune cells and the immune checkpoints. Finally, we explored the impact of expression and genomic polymorphism of the signatures on the prognosis at the pan-cancer level. CONCLUSIONS: Our findings underscore the distinct expression patterns of CRGs in esophageal cancer. These signatures are efficient to serve as prognostic indicators and assess the effectiveness of immunotherapy. They may also represent promising targets in other TP53 mutant malignancies.

Humans

Gain-of-function PPM1D mutations attenuate ischemic stroke.

Identification of genetic aberrations in stroke, the second leading cause of death worldwide, is of paramount importance for understanding the disease pathogenesis and generating new therapies. Whole-genome sequencing from 10,241 ischemic stroke patients identified eight patients carrying gain-of-function mutations on coding variants in the protein phosphatase magnesium-dependent 1 &#x3b4; (PPM1D) gene. Patients carrying PPM1D mutations exhibit better stroke-related clinical phenotypes, including improvements in peripheral inflammation, fibrinogen, low-density lipoprotein, cholesterol&#xa0;and plateletcrit level. Experimental brain ischemia in Ppm1d-deficient (Ppm1d-/-) mice resulted in enlarged lesions and pronounced neurological impairments. Spatial transcriptomics revealed a distinct Ppm1d-associated gene expression pattern, indicating disrupted endothelial homeostasis during ischemic brain injury. Proteomic analysis demonstrated that differentially expressed proteins in primary brain endothelial cells from Ppm1d-/- mice were significantly enriched in the peroxisome proliferator-activated receptors (PPARs)-mediated metabolic signaling. Mechanistically, Ppm1d deficiency promoted aberrant fatty acid &#x3b2;-oxidation and increased oxidative stress, which impaired endothelial cell function through the PPAR&#x3b1; pathway. A small molecule, T2755, was identified to engage Trp427 and stabilize PPM1D, thereby mitigating ischemic brain injury in mice. Collectively, we find that PPM1D protects against ischemic brain injury and validates its pharmacological stabilizer T2755 as a promising therapy for ischemic stroke. Gain-of-function PPM1D mutations attenuate ischemic cerebral injury. Whole-genome sequencing data of 10,241 ischemic stroke patients from the Third Chinese National Stroke Registry (CNSR-III) identified eight patients with gain-of-function mutations in the protein phosphatase magnesium-dependent 1 &#x3b4; (PPM1D) gene (17q23.2). These mutation carriers displayed improved peripheral inflammation,&#xa0;decreased&#xa0;fibrinogen, low-density lipoprotein, cholesterol&#xa0;and plateletcrit level. Ppm1d-deficient (Ppm1d-/-) mice exhibited exacerbated stroke outcomes, characterized by enlarged infarct volumes, disrupted cerebrovascular architecture, and enhanced neuro-inflammation. Mechanistically, Ppm1d deficiency induced the disturbance of endothelial fatty acid metabolism involving the PPAR&#x3b1; pathway. Through integrated computational modeling, virtual screening, and in vitro validation, T2755 was identified as a small molecule PPM1D stabilizer. Pharmacological PPM1D stabilization with T2755 significantly attenuated ischemic brain injury in murine models.

Aged

Association among blood pressure, antihypertensive drugs, and amyotrophic lateral sclerosis.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a fatal and incurable neurodegenerative disease. The impacts of antihypertensive drugs and blood pressure (BP) on ALS are currently debatable. OBJECTIVE: To evaluate the causal relationship involving antihypertensive drugs, BP, and ALS through a Mendelian randomization (MR) analysis. METHODS: The causal relationship between BP and ALS was evaluated by a bidirectional two-sample MR analysis. Then, a sensitivity analysis was performed using a secondary BP genome-wide association study. The drug-target MR was employed to evaluate the impact of antihypertensive drugs on ALS. Furthermore, we used cis-expression quantitative trait loci (cis-eQTLs) data from brain tissue and blood to validate the positive results by a summary-based MR method. RESULTS: We found that an increment in systolic BP (SBP) could elevate the risk of ALS (inverse-variance weighted [IVW] odds ratio [OR]&#x2009;=&#x2009;1.003; 95% confidence interval [95%CI]: 1.001-1.006; per 10-mmHg increment) and ALS might be protected by angiotensin-converting enzyme inhibitors (ACEIs; OR&#x2009;=&#x2009;0.970; 95%CI: 0.956-0.984; p&#x2009;=&#x2009;1.96&#x2009;&#xd7;&#x2009;10-5; per 10-mmHg decrement). A causal relationship was not observed between diastolic BP and other antihypertensive drugs in ALS. CONCLUSION: In the present study, genetic support for elevated SBP serves as a risk factor for ALS. Besides, ACEIs hold promise as a candidate for ALS.

Humans

EPIPDLF: a pretrained deep learning framework for predicting enhancer-promoter interactions.

MOTIVATION: Enhancers and promoters, as regulatory DNA elements, play pivotal roles in gene expression, homeostasis, and disease development across various biological processes. With advancing research, it has been uncovered that distal enhancers may engage with nearby promoters to modulate the expression of target genes. This discovery holds significant implications for deepening our comprehension of various biological mechanisms. In recent years, numerous high-throughput wet-lab techniques have been created to detect possible interactions between enhancers and promoters. However, these experimental methods are often time-intensive and costly. RESULTS: To tackle this issue, we have created an innovative deep learning approach, EPIPDLF, which utilizes advanced deep learning techniques to predict EPIs based solely on genomic sequences in an interpretable manner. Comparative evaluations across six benchmark datasets demonstrate that EPIPDLF consistently exhibits superior performance in EPI prediction. Additionally, by incorporating interpretable analysis mechanisms, our model enables the elucidation of learned features, aiding in the identification and biological analysis of important sequences. AVAILABILITY AND IMPLEMENTATION: The source code and data are available at: https://github.com/xzc196/EPIPDLF.

Deep Learning

The super-enhancer regulatory gene SH2D1A promotes the progression of T cell acute lymphoblastic leukemia by activating CHI3L2.

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive leukemia subtype and a prevalent malignancy in children, with poor prognosis, high relapse rates, and drug resistance. Recent research has shown that super-enhancer-regulated genes play crucial roles in T-ALL progression. In this study, we identified SH2 domain containing 1&#xa0;A (SH2D1A) as a gene regulated by super-enhancers, and is overexpressed, which correlates with unfavorable clinical outcomes in T-ALL. To investigate its role, we silenced SH2D1A expression in T-ALL cell models using RNA interference. This led to a significant reduction in cell proliferation, colony formation, and promoted apoptosis, as demonstrated by CCK-8 assays, soft agar colony formation, and flow cytometry analysis. In vivo, knockdown of SH2D1A significantly inhibited tumor growth and prolonged survival in mice bearing T-ALL. Mechanistically, we found that SH2D1A contributes to T-ALL progression by upregulating CHI3L2, a downstream effector that promotes cell proliferation and inhibits apoptosis. Using ChIP-Seq and RNA-seq technologies, we confirmed that SH2D1A regulates CHI3L2 expression through super-enhancer-mediated regulation in T-ALL cells. Our findings suggest that SH2D1A and CHI3L2 act as oncogenes in T-ALL, and may represent novel therapeutic targets. This research offers new insights into the molecular mechanisms of T-ALL and highlights potential avenues for therapeutic intervention.

Precursor T-Cell Lymphoblastic Leukemia-Lymphoma

A genomic and phenotypic investigation of pigeon-adaptive Salmonella.

Salmonella, a significant threat to public safety, inflicts substantial economic losses on the poultry industry. The unique "parental feeding" breeding model of pigeon farms, against the "all-in & all-out" biosecurity strategy, makes them susceptible to Salmonella infections and subsequent outbreaks of pigeon paratyphoid. This study initially studied three pigeon paratyphoid outbreak incidents in Henan, China, in which 53 strains of pigeon-origin Salmonella Typhimurium (STM) were identified. Whole-genome sequencing (WGS) and antimicrobial-resistant profile analysis revealed that the three outbreaks were caused by distinct STM clones (ST128-DT2, ST19-DT99). Global phylogenetic analysis suggested that the United States is a possible origin, indicating a risk of intercontinental transmission via pigeon eggs. Further bacterial virulence and invasion assays, including in vitro and in vivo assays, revealed that pigeon-host-adaptive STM, compared to broad-host-range STM, carried fewer resistance genes, exhibited higher invasion indices and pseudogene levels, displayed a non-rdar (red dry and rough) phenotype, and had strong biofilm formation capability. Additionally, they showed reduced virulence and invasiveness in mice but a pigeon-adaptive feature in cogent models. The collective results support the host adaptation for pigeons among DT2 and DT99 phage-type isolates.

Animals

Structural variants linked to Alzheimer's disease and other common age-related clinical and neuropathologic traits.

BACKGROUND: Alzheimer's disease (AD) is a complex neurodegenerative disorder with substantial genetic influence. While genome-wide association studies (GWAS) have identified numerous risk loci for late-onset AD (LOAD), the functional mechanisms underlying most of these associations remain unresolved. Large genomic rearrangements, known as structural variants (SVs), represent a promising avenue for elucidating such mechanisms within some of these loci. METHODS: By leveraging data from two ongoing cohort studies of aging and dementia, the Religious Orders Study and Rush Memory and Aging Project (ROS/MAP), we performed genome-wide association analysis testing 20,205 common SVs from 1088 participants with whole genome sequencing (WGS) data. A range of Alzheimer's disease and other common age-related clinical and neuropathologic traits were examined. RESULTS: First, we mapped SVs across 81 AD risk loci and discovered 22 SVs in linkage disequilibrium (LD) with GWAS lead variants and directly associated with the phenotypes tested. The strongest association was a deletion of an Alu element in the 3'UTR of the TMEM106B gene, in high LD with the respective AD GWAS locus and associated with multiple AD and AD-related disorders (ADRD) phenotypes, including tangles density, TDP-43, and cognitive resilience. The deletion of this element was also linked to lower TMEM106B protein abundance. We also found a 22-kb deletion associated with depression in ROS/MAP and bearing similar association patterns as GWAS SNPs at the IQCK locus. In addition, we leveraged our catalog of SV-GWAS to replicate and characterize independent findings in SV-based GWAS for AD and five other neurodegenerative diseases. Among these findings, we highlight the replication of genome-wide significant SVs for progressive supranuclear palsy (PSP), including markers for the 17q21.31 MAPT locus inversion and a 1483-bp deletion at the CYP2A13 locus, along with other suggestive associations, such as a 994-bp duplication in the LMNTD1 locus, suggestively linked to AD and a 3958-bp deletion at the DOCK5 locus linked to Lewy body disease (LBD) (P&#x2009;=&#x2009;3.36&#x2009;&#xd7;&#x2009;10-4). CONCLUSIONS: While still limited in sample size, this study highlights the utility of including analysis of SVs for elucidating mechanisms underlying GWAS loci and provides a valuable resource for the characterization of the effects of SVs in neurodegenerative disease pathogenesis.

Humans

Rice transcription factor bHLH25 confers resistance to multiple diseases by sensing H2O2.

Hydrogen peroxide (H2O2) is a ubiquitous signal regulating many biological processes, including innate immunity, in all eukaryotes. However, it remains largely unknown that how transcription factors directly sense H2O2 in eukaryotes. Here, we report that rice basic/helix-loop-helix transcription factor bHLH25 directly senses H2O2 to confer resistance to multiple diseases caused by fungi or bacteria. Upon pathogen attack, rice plants increase the production of H2O2, which directly oxidizes bHLH25 at methionine 256 in the nucleus. Oxidized bHLH25 represses miR397b expression to activate lignin biosynthesis for plant cell wall reinforcement, preventing pathogens from penetrating plant cells. Lignin biosynthesis consumes H2O2 causing accumulation of non-oxidized bHLH25. Non-oxidized bHLH25 switches to promote the expression of Copalyl Diphosphate Synthase 2 (CPS2), which increases phytoalexin biosynthesis to inhibit expansion of pathogens that escape into plants. This oxidization/non-oxidation status change of bHLH25 allows plants to maintain H2O2, lignin and phytoalexin at optimized levels to effectively fight against pathogens and prevents these three molecules from over-accumulation that harms plants. Thus, our discovery reveals a novel mechanism by which a single protein promotes two independent defense pathways against pathogens. Importantly, the bHLH25 orthologues from available plant genomes all contain a conserved M256-like methionine suggesting the broad existence of this mechanism in the plant kingdom. Moreover, this Met-oxidation mechanism may also be employed by other eukaryotic transcription factors to sense H2O2 to change functions.

Hydrogen Peroxide

Constructing epigenetic regulatory landscapes of plant lncRNAs-an exploration utilizing the novel specialized platform PERlncDB.

Long non-coding RNAs (lncRNAs), once overlooked as transcriptional byproducts, are now recognized for their crucial roles in plant growth, development, and stress responses, with increasing focus on their epigenetic regulation. However, studies investigating epigenomic signals to explore the functions of lncRNAs in plants remain relatively limited. This study collected a comprehensive dataset of over 160&#x2009;000 high-quality lncRNAs from 19 representative plant species and integrated 6715 ChIP-seq, BS-seq, and RNA-seq datasets to analyze epigenomic patterns at lncRNA loci. Results showed elevated DNA methylation in lncRNA regions. The highest levels occurred in transposable element-associated lncRNAs. Additionally, activating histone modifications at lncRNA loci showed tissue specificity, with epigenetic preferences differed from those at protein-coding gene (PCG) loci. Differential site analysis in epigenetic mutants further highlighted the selective regulation of lncRNA loci by specific epigenetic factors. To facilitate research, we developed PERlncDB, a platform that provides species-specific lncRNA browsing, epigenetic annotation, cross-species conservation analysis, and visualization of epigenomic landscapes. Case studies on MARS and LINC-AP2 emphasized the platform's utility. Conserved epigenetic mechanisms regulating lncRNAs across species, exemplified by a syntenic conserved MET1-regulated lncRNA pair in Arabidopsis and tomato, suggested the stability of regulatory mechanisms underlying lncRNA functions. This work provides critical insights and resources for understanding plant lncRNA epigenetic regulation.

RNA, Long Noncoding

An increased copy number of glycine decarboxylase (GLDC) associated with psychosis reduces extracellular glycine and impairs NMDA receptor function.

Glycine is an obligatory co-agonist at excitatory NMDA receptors in the brain, especially in the dentate gyrus, which has been postulated to be crucial for the development of psychotic associations and memories with psychotic content. Drugs modulating glycine levels are in clinical development for improving cognition in schizophrenia. However, the functional relevance of the regulation of glycine metabolism by endogenous enzymes is unclear. Using a chromosome-engineered allelic series in mice, we report that a triplication of the gene encoding the glycine-catabolizing enzyme glycine decarboxylase (GLDC) - as found on a small supernumerary marker chromosome in patients with psychosis - reduces extracellular glycine levels as determined by optical fluorescence resonance energy transfer (FRET) in dentate gyrus (DG) and suppresses long-term potentiation (LTP) in mPP-DG synapses but not in CA3-CA1 synapses, reduces the activity of biochemical pathways implicated in schizophrenia and mitochondrial bioenergetics, and displays deficits in schizophrenia-like behaviors which are in part known to be dependent on the activity of the dentate gyrus, e.g., prepulse inhibition, startle habituation, latent inhibition, working memory, sociability and social preference. Our results demonstrate that Gldc negatively regulates long-term synaptic plasticity in the dentate gyrus in mice, suggesting that an increase in GLDC copy number possibly contributes to the development of psychosis in humans.

Animals