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Biomedical subjects

Li Li

Publications and source records attributed to Li Li.

At least 19 recordsLinked to original sources

BRD9 Degraders Unleash GBAF Chromatin Remodeling Activity in Synovial Sarcoma.

UNLABELLED: Synovial sarcoma incorporates the SS18::SSX fusion oncoprotein into GLTSCR1-containing BRG1/BRM and associated factors (GBAF) complexes, which confers a dependency on the GBAF subunit BRD9. However, synovial sarcoma clinical trials with multiple BRD9 degraders failed to achieve clinically impactful remissions. In this study, we identified a mechanistic framework to explain these results. BRD9 depletion served to blunt proliferation in synovial sarcoma harboring minimal genomic alterations, rare in trial participants. In cultured cells, xenografts, and recombinant-purified complexes, BRD9 loss did not affect GBAF assembly. Although BRD9 degradation in synovial sarcoma reduced GBAF enrichment at target loci, BRD9-less complexes maintained or increased chromatin accessibility and associated gene transcription. Biochemical assays with purified recombinant GBAF demonstrated increased nucleosome sliding in the absence of BRD9. Together, these findings show that BRD9 restrains GBAF activity, with BRD9 degradation increasing enzymatic remodeling and target gene expression by fusion oncoprotein-distributed GBAFs in synovial sarcoma. This subtle epigenetic disturbance creates a low hurdle for synovial sarcoma to surpass, limiting the therapeutic efficacy of BRD9 degraders. SIGNIFICANCE: BRD9 represses the GBAF chromatin remodeling complex, which causes enhanced rather than disrupted SS18::SSX complex activity following BRD9 degradation and explains the lack of efficacy of pharmacological BRD9 degraders in synovial sarcoma.

Sarcoma, Synovial

Biomarker Analysis from Patients with Metastatic PDAC Treated with TGFβ Antibody NIS793 plus Abraxane + Gemcitabine versus Abraxane + Gemcitabine Alone in a Phase II, Open-Label, Randomized Study.

PURPOSE: Transforming growth factor β (TGFβ) plays a dual role in cancer, acting as a tumor suppressor early in the disease but promoting progression and immune evasion when dysregulated. In pancreatic ductal adenocarcinoma (PDAC), TGFβ-driven desmoplasia fosters chemoresistance and immunosuppression, limiting therapeutic efficacy. NIS793, a fully human mAb targeting TGFβ, demonstrated antifibrotic and immunomodulatory activity in preclinical models and early-phase trials. PATIENTS AND METHODS: We conducted a randomized, open-label, phase II study in treatment-naïve patients with metastatic PDAC (mPDAC) to evaluate NIS793 ± spartalizumab (anti-PD-1) combined with nab-paclitaxel (or Abraxane)/gemcitabine (ABRA/GEM) versus ABRA/GEM alone. The primary endpoint was progression-free survival (PFS); secondary endpoints included overall survival (OS), safety, pharmacokinetics, and biomarker analyses. Exploratory assessments included paired tumor RNA sequencing, cell-free DNA profiling, and plasma proteomics. RESULTS: NIS793 demonstrated target engagement and suppression of TGFβ signaling, confirmed by transcriptomic and proteomic analyses. Stromal remodeling was evident, with significant downregulation of cancer-associated fibroblast markers (Acta2, Fap) and collagen-related signatures. Despite proof of mechanism, clinical efficacy was not observed: Median PFS and OS were comparable or numerically worse in the NIS793 arm versus control (HR for OS in NIS793 + ABRA/GEM vs. ABRA/GEM: 1.32; 95% confidence interval, 0.84-2.07). The safety profile was manageable, with no unexpected toxicities. Biomarker data revealed increased expression of neutrophil-related genes after treatment, suggesting potential induction of tumor-promoting inflammation. CONCLUSIONS: NIS793 effectively inhibited TGFβ signaling and led to stromal remodeling but failed to improve outcomes in mPDAC. These findings highlight the complexity of TGFβ biology and caution against its blockade in combination with chemotherapy for PDAC. Future strategies should consider context-dependent effects of TGFβ inhibition.

Humans

Genome-wide CRISPR screens map synthetic lethal interactions across recurrent cancer driver alterations.

Synthetic lethality (SL) provides a treatment paradigm for targeting cancer with alterations in driver genes that are not conventionally druggable, including tumor suppressor genes. We execute a series of genome-wide CRISPR screens using functionally validated isogenic cell lines and conduct a large-scale SL analysis using data from the cancer dependency map (DepMap). We chart SL interactions across 15 driver alterations: FBXW7, CCNE1, CDK12, ARID1A, KMT2D, DNMT3A, TET2, KEAP1, STK11, IDH1, SF3B1, SRSF2, U2AF1, chromosome 18q loss, and chromosome 13q loss. We show validation of several SL interactions, including ARID1A and the hexosamine biosynthetic pathway aminotransferase GFPT1, STK11 with CAMK protein kinase MARK2, FBXW7 and the CDK1 regulatory kinase PKMYT1, and CCNE1 amplification and the anaphase-promoting complex or cyclosome (APC/C). In summary, this study offers a rich resource of genetic interactions across cancer drivers enabling the discovery of biological insights and drug targets for future therapeutic development.

CP: cancer

Precision UV-B irradiation for flavonoid biofortification in indoor-cultivated Morus nigra: Integrated multi-omics and molecular docking insights.

Precision application of UV irradiation represents an effective strategy for improving the quality of functional food crops under controlled environmental conditions. Morus nigra serves as a significant functional food resource in Xinjiang, with its leaves being rich in diverse bioactive compounds with nutritional and health-promoting properties. In this study, a low-dose UV-B treatment regimen was developed to enhance flavonoids in indoor-cultivated M. nigra without growth penalty. Multi-omics revealed a hormone shift (suppressed auxin vs. activated JA signaling). This triggered transcriptional reprogramming of PAL/4CL and CHS/CYP75B1, redirecting carbon flux towards flavonoid biosynthesis. Transient overexpression of MYB, NAC, and TIFY variants validated this regulatory network. The UV-B-induced NAC upregulated key genes and flavonoids, while different TIFY members showed diverse regulatory effects. Molecular docking predicted that the induced flavonoids had hypoglycemic, antioxidant, and anti-browning potential. This study indicates targeted UV-B as a green biofortification strategy for high-value crops in controlled environments.

Flavonoid biosynthesis

Integrating single-cell transcriptomics to construct an oncogene-driven prognostic model and elucidate metabolic-immune crosstalk in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths, its progression and treatment heterogeneity are mainly influenced by driver gene and tumor micro-environment (TME) interactions. Nevertheless, the mechanisms of this process at the single-cell level remain unclear. This study integrated TCGA and multi-center single-cell transcriptome data to identify a 575 genes HCC-specific core set, developing a single-cell "oncogene scoring" system to quantify individual carcinogenic activity. This score is significantly elevated in malignant and proliferative T cells and is closely associated with metabolic reprogramming, aberrant cell‒cell communication, and immunosuppressive phenotypes. Based on these characteristics, we constructed a machine learning-based Random Survival Forest (RSF) prognostic model validated in multiple independent cohorts, which classifies patients into distinct risk subtypes. The high-risk group exhibits genomic instability, increased tumor stemness, and immune evasion, while the low-risk group was more sensitive to drugs such as sorafenib. This study highlights the potential pathways by which high oncogenic activity is associated with HCC progression, suggesting a profound link with single-cell metabolic‒immune crosstalk. The constructed RSF model offers a promising computational framework for risk stratification and provides hypothesis-generating insights that may inform future personalized treatment strategies for HCC patients.

Hepatocellular carcinoma

Waist-to-height ratio as a practical indicator for screening pediatric metabolic dysfunction-associated steatotic liver disease in diverse populations and genetic backgrounds.

BACKGROUND: Metabolic dysfunction-associated steatotic liver disease (MASLD) is the leading chronic liver disease in children and adolescents; this parallels the global obesity epidemic. The contribution of genetic susceptibility to pediatric MASLD, and its interaction with anthropometric and biochemical indices used for non-invasive screening remains poorly understood. We aimed to evaluate waist-to-height ratio (WHtR) as a simple, equitable, and scalable tool for early identification of pediatric MASLD and relate this to genetic risk. METHODS: We combined school-based data from 1010 Chinese children with analyses of the Global Burden of Disease, the 1000 Genomes Project, and the US National Health and Nutrition Examination Survey (NHANES). Thirteen MASLD-related single-nucleotide polymorphisms (SNPs) were genotyped to construct a genetic risk score (GRS). We examined global epidemiological patterns, quantified inter-population allele divergence, and assessed how GRS modifies cutoffs and performance of nine anthropometric and biochemical indices. RESULTS: Genetic analysis revealed minimal frequency divergence across most ancestries (mean Fixation index&#x2009;<&#x2009;0.05), except for the African ancestry where there was moderate divergence. Higher GRS were associated with lower cutoffs across indices. When GRS Z-score increased from -3 to 3, visceral adiposity index showed the sharpest changes (Z-score decreased from 1.5 to -1.8), while BFP (1.2&#xa0;to&#xa0;0.1) and WHtR (1.5&#xa0;to&#xa0;0.1) showed gradual change. Furthermore, incorporating GRS into the base anthropometric models yielded only marginal improvements in overall screening performance [area under the receiver operating characteristic curve (AUC) and Youden Index]. Validation in NHANES showed WHtR&#x2009;&#x2265;&#x2009;0.48 retained high discrimination (AUC&#x2009;>&#x2009;0.87) across most genetic variants. CONCLUSIONS: This study suggests that WHtR is a consistent and practical tool for screening pediatric patients with MASLD across diverse populations. While genetic variation may influence optimal thresholds, WHtR&#x2009;&#x2265;&#x2009;0.48 appears broadly applicable, supporting its potential use as a frontline screening metric in diverse settings.

Humans

Bergamottin, a bioactive component of bergamot: dual inhibition of Japanese encephalitis virus internalization and genome replication.

Japanese encephalitis virus (JEV) is associated with high mortality and severe neurological sequelae, and existing prevention and control strategies remain insufficient. Therefore, the development of novel antiviral agents is of critical public health importance. This study systematically evaluated the antiviral activity and underlying mechanism of bergamottin, a natural product. Bergamottin exhibited significant dose-dependent inhibitory effects against JEV in multiple cell lines, including BHK-21, HuH-7, and Vero cells, demonstrating potent antiviral efficacy. Mechanistic investigations revealed that bergamottin primarily targeted the internalization and replication stages of the JEV life cycle, thereby effectively suppressing viral proliferation. Additionally, adaptive mutation screening indicated that the D389G mutation in envelope protein E confers drug resistance by potentially changing E protein conformation or reducing endocytic efficiency. In vivo experiment, bergamottin significantly reduced viral loads in mouse brain tissue and effectively improved the survival rate of infected mice. Our findings indicated that bergamottin exerted antiviral activity by dual targeting of key steps in the viral life cycle, making it a highly promising candidate for anti-JEV therapy. Further exploration of the antiviral properties of bergamottin is expected to facilitate its clinical development as a treatment for JEV infection.

Animals

wbp-encoded LPS O-antigen architecture as a prognostic and therapeutic target in Pseudomonas aeruginosa keratitis.

BACKGROUND: Pseudomonas aeruginosa (P. aeruginosa) keratitis can progress rapidly to vision-threatening disease, even with intensive therapy. Virulence-associated genes are key determinants of ocular-surface pathogenesis. We therefore sought to develop a composite wbp-exo genotyping framework for risk stratification and to guide wbp-dependent, LPS-directed, levofloxacin-polymyxin B (LVX-POL) combination therapy for high-risk corneal infections. METHODS: A well-characterised clinical P. aeruginosa keratitis cohort was integrated with whole-genome sequencing. Based on comprehensive virulence-gene identification and annotation, the relationship between strain-level genetic features and clinical prognosis was analysed. The differences between WBP1 strains and WBP2 strains in adhesion, invasion, and biofilm formation in corneal epithelial cells were further evaluated. To establish biological plausibility, wbp genotypes were correlated with LPS O-antigen electrophoretic profiles and in vivo corneal inflammatory phenotypes in murine infection, including the observation of leucocyte recruitment and cytokine responses. To further confirm the key role of wbp gene status and LPS O-antigen in pathogenicity, wbpL knockout and reconstitution strains were constructed. Their appearances in vitro and in vivo were evaluated. Finally, a mechanistic rationale for an LPS-directed LVX-POL regimen was tested in a high-risk WBP1 P. aeruginosa murine keratitis. FINDINGS: Whole-genome sequencing was performed on 46 clinical P. aeruginosa isolates and identified an average of 332 virulence- and fitness-associated genes per strain. The exo and wbp gene families were significantly associated with patient prognosis. A fusion model (AUC = 0.86) outperformed single-gene-family models (EXO: 0.66; WBP: 0.72) for predicting clinical outcomes. Intact wbp cassettes were enriched in poor-outcome isolates, and electrophoretic LPS profiles indicated that WBP1 strains produce highly polymerised O-antigen associated with sustained neutrophil recruitment and cytokine production. Murine experiments further implicated wbp genes in clinical pathogenesis, showing stronger immune responses and higher expression of TLR4, MyD88, TRAF6, p65, p-p65, IL-6, TNF-&#x3b1;, and IL-1&#x3b2; throughout the inflammatory course. After knocking out wbpL gene, the WBP1 strain got stronger in biofilm formation and adhesion but weaker in inflammation and ocular surface survival. In the high-risk WBP1 P. aeruginosa keratitis model, LVX-POL combinations achieved complete ulcer resolution and markedly improved stromal infiltration and hypopyon, outperforming LVX monotherapy. INTERPRETATION: The wbp gene family was identified as a key genetic factor that contributes to the LPS O-antigen structure, inflammatory intensity, bacterial ocular surface survival and poor prognosis in P. aeruginosa keratitis. A WBP1-targeted, LPS-directed LVX-POL regimen was proposed as a mechanistically informed option for high-risk strains. FUNDING: This research was supported by Beijing Public Health High-level Talent Training Program (Phase III-03-14), Prevention and Control of Emerging and Major Infectious Diseases-National Science and Technology Major Project (2026ZD01909300) and Beijing Natural Science Foundation "QiYan" Undergraduate Research Fund (QY26496).

Pseudomonas aeruginosa

Multi-omics analysis reveals stage-associated differences in gut immunity and microbiota between juvenile and adult common carp (Cyprinus carpio).

In vertebrates, the development of intestinal immunity is closely associated with dynamic changes in the gut microbiota. However, stage-associated differences in intestinal immunity and gut microbial communities remain poorly characterized in teleost fish. In this study, transcriptomic analysis combined with 16S rRNA gene sequencing was employed to characterize intestinal immunity and gut microbial communities in juvenile and adult common carp (Cyprinus carpio). Transcriptomic profiling revealed marked developmental differences in intestinal immune function. Juvenile carp exhibited a predominantly innate immune phenotype, characterized by elevated expression of pro-inflammatory cytokines, antimicrobial peptides, and lysozyme-related genes. This immune profile was accompanied by enhanced mucosal barrier function and a relatively pro-inflammatory intestinal environment. In contrast, adult carp displayed increased expression of genes associated with adaptive immunity, suggesting that adult common carp exhibit relatively stronger adaptive immune characteristics than juvenile fish. Gut microbiota analysis demonstrated significant stage-dependent differences in microbial diversity and community composition. Juvenile fish were enriched with bacterial taxa potentially associated with innate immune activation, whereas adult fish harbored distinct microbial communities linked to intestinal homeostasis and barrier maintenance. Furthermore, correlation analyses identified significant associations between specific microbial taxa and innate immune-related gene expression, suggesting a close association between gut microbiota composition and intestinal immune characteristics in juvenile and adult common carp. Collectively, these findings reveal stage-associated differences in intestinal immunity and gut microbial communities between juvenile and adult common carp, thereby providing insights into intestinal immune characteristics at different developmental stages in teleost fish.

Animals

Reduced expression of Brain Expressed X-linked genes in Alzheimer's disease.

BackgroundAltered expression of Brain Expressed X-linked (BEX) genes has been implicated in Alzheimer's disease (AD) with inconsistencies and a lack of experimental confirmation.ObjectiveThis study aims to characterize BEX expression patterns, examine the association of their expression with AD pathology, and investigate cellular changes induced by altered BEX expression.MethodsWe integrated bulk and single-cell transcriptomics datasets to characterize cortical BEX expression changes in 5xFAD mice and AD patients, which were validated by RT-qPCR in postmortem AD cortical tissue. We manipulated the expression of BEX genes in SH-SY5Y cells and examined changes in oxidative stress.ResultsCortical expression of BEX genes was reduced in AD. With the dysregulation being more pronounced at a later stage of the disease, the reduction was closely related to the impairment of synaptic transmission and oxidative phosphorylation in excitatory neurons. Consistent with these, BEX3 knockdown increased oxidative stress.ConclusionsOur findings suggest that reduced BEX expression in neurons appears to be a contributing factor to AD pathogenesis and BEX depletion may increase oxidative stress.

Alzheimer Disease

Histopathological evaluation of RPL5 expression in triple-negative breast cancer: an integrated immunohistochemical and transcriptomic study.

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer characterized by high invasiveness, limited therapeutic options, and unfavorable clinical outcomes. Ribosomal protein L5 (RPL5), a component of the large ribosomal subunit, has been implicated in ribosome biogenesis, translational regulation, and p53-associated cellular processes. This study investigated the immunohistochemical expression pattern of RPL5 in TNBC tissues and explored its potential biological significance through integrated transcriptomic analyses. Tumor tissues from 37 patients with TNBC and 7 adjacent non-tumorous breast tissues were collected from the Affiliated Tumor Hospital of Xinjiang Medical University between December 2017 and December 2023. RPL5 protein expression was evaluated by immunohistochemistry, and its association with clinicopathological characteristics was analyzed. Public transcriptomic datasets from TCGA-BRCA and GEO were further used to validate RPL5 expression patterns in TNBC. Co-expression analysis and Gene Ontology (GO)/Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed to investigate potential biological functions and signaling pathways associated with RPL5. Immunohistochemical analysis demonstrated significantly lower RPL5 protein expression in TNBC tissues compared with adjacent normal breast tissues (p=0.001). In contrast, transcriptomic analyses revealed significantly higher RPL5 expression in TNBC compared with non-TNBC breast cancer subtypes (p<0.001). No significant associations were observed between RPL5 expression and clinicopathological parameters, including age, tumor size, menopausal status, TNM stage, histological grade, or lymph node metastasis (all p>0.05). Survival analysis showed no significant difference in overall survival between patients with high and low RPL5 expression. Functional enrichment analyses indicated that RPL5-related genes were predominantly involved in ribosome biogenesis, translational regulation, and p53-related signaling pathways. These findings suggest that abnormal RPL5 expression may be associated with TNBC biology through ribosome-related programs, although causal roles require functional validation. RPL5 may represent a potential histopathological and molecular indicator associated with TNBC biology, although its precise functional role requires further experimental validation.

Humans

Identifying the regulatory network of the key lipid metabolism transcription factor peroxisome proliferator-activated receptor in oysters.

Rising seawater temperatures driven by global warming have led to summer mass mortality events that pose significant challenges for the oyster industry. Peroxisome proliferator-activated receptor (PPAR) serves as a key transcriptional regulator of lipid metabolism and plays an essential role in thermal adaptation. However, the upstream regulatory mechanisms of PPAR remain poorly understood in marine organisms. In this study, we identified two PPAR subtypes (PPAR&#x3b1; and PPAR&#x3b2;/&#x3b4;) in oysters and compared transcriptomic data in different tissues and under various environmental stressors, with PPAR&#x3b1; exhibiting higher expression levels and responsiveness to environmental stresses. We observed significantly higher PPAR&#x3b1; gene expression levels and promoter activity in the relatively cold-tolerant Crassostrea gigas compared to C. angulata. The low expression of the inhibitory transcription factor CTNNB1 in C. gigas may contribute to higher gene expression of PPAR&#x3b1;. Additionally, the expression genome-wide association study (eGWAS) identified 9 significant SNPs and 124 candidate regulatory genes associated with PPAR&#x3b1; expression, including ubiquitination, phosphorylation, signaling pathways, lipid metabolism, and glucose metabolism. We provided the first experimental validation of the PPAR&#x3b1; ubiquitination-degradation pathway in marine organisms via Co-IP, which was mediated by the E3 ligase RFWD3. The protein kinase SNF1 and signaling-related proteins PIKA and KCNK2 indirectly modulated PPAR&#x3b1; downstream pathway activation to varying degrees. This study presents the first systematic investigation of PPAR&#x3b1; expression regulation in marine organisms. It identifies key molecular regulators and provides novel insights into lipid metabolic regulation and molecular targets for genetic improvement of heat tolerance in oysters under global warming.

Animals

Source- and Solubility-specific Choline, Gut Microbiota, and Dyslipidemia Risk: Trimethylamine N-oxide-associated and Non-trimethylamine N-oxide-Associated Patterns in a Prospective Cohort Study.

BACKGROUND: Dietary choline, a major precursor of the gut microbial metabolite trimethylamine N-oxide (TMAO), is implicated in dyslipidemia risk; however, source- and form-specific associations and interactions with gut microbiota remain unclear. OBJECTIVES: The aim of this study was to examine longitudinal associations of source- and form-specific dietary choline with plasma TMAO and dyslipidemia and to identify gut microbiota interactions. METHODS: Using data from the China Health and Nutrition Survey (2018-2023), dietary intake was assessed via 3 consecutive 24-h recalls in this prospective cohort study. Two-level generalized linear mixed-effects models were applied in 4828 adults (mean age: 55.9 &#xb1; 12.6 y, 56.6% females) to assess choline-dyslipidemia associations. Choline-TMAO and TMAO-dyslipidemia analyses were conducted in 1091 participants free of dyslipidemia at baseline. Among 7169 adults with gut microbiome data, Least Absolute Selection and Shrinkage Operator and logistic regression identified lipid-associated gut genera; TMAO relationships were examined in a subset of 693 participants. RESULTS: Higher intakes of total [Q4 compared with Q1: odds ratio (OR) = 1.261; 95% confidence interval (CI): 1.007, 1.580], red meat-derived (OR: 1.753; 95% CI: 1.196, 2.568), and lipid-soluble choline (OR: 1.304; 95% CI: 1.047, 1.624) were associated with higher risk of elevated low-density lipoprotein cholesterol (LDL cholesterol), whereas vegetable-derived choline was inversely associated. Egg-derived and lipid-soluble choline were positively associated with plasma TMAO, which was prospectively associated with 5-y incident dyslipidemia (Q4 compared with Q1-OR: 1.620; 95% CI: 1.047, 2.509), elevated LDL cholesterol (Q3 compared with Q1-OR: 2.478; 95% CI: 1.187, 5.174), and hypertriglyceridemia (Q4 compared with Q1-OR: 1.829; 95% CI: 1.028, 3.225). Three TMAO-associated genera were identified: Lachnospiraceae and Phascolarctobacterium as pro-risk taxa and Turicibacter as protective. The adverse LDLcholesterol association of egg-derived choline was observed exclusively in Phascolarctobacterium-enriched individuals. CONCLUSIONS: Dietary choline source and solubility differentially associated with dyslipidemia risk through TMAO-associated and non-TMAO-associated patterns, with gut microbiota as key modulators.

Humans

Carboxyl group number and acidity of organic acids regulate structural reorganization and low glycemic index in cassava pyrodextrins via molecular interactions.

Transforming high-glycemic cassava starch into functional dietary fiber via pyrodextrinization is a promising way to valorize tuber crops, yet the molecular mechanisms catalyzed by organic acids with different carboxyl numbers and acidity remain unclear. This study investigates how carboxyl number and acidity of acetic acid (AA), tartaric acid (TA), and citric acid (CA) affect structural reorganization and low glycemic properties of cassava pyrodextrins. Compared with AA, TA, and CA with stronger acidity and more carboxyl groups promoted more extensive hydrolysis, transglycosylation, repolymerization, and esterification. These changes increased indigestible glycosidic linkages and the branching degree, while reducing molecular weight. Molecular docking confirmed stronger hydrogen-bonding interactions between TA/CA and starch chains. Furthermore, TA- and CA-catalyzed pyrodextrins exhibited superior anti-digestive properties with resistant starch up to 54.26% and an estimated glycemic index as low as 42.46, highlighting the critical role of carboxyl numbers and acidities in modulating the functionality of pyrodextrins.

Manihot

Amino-acids-mTORC1-driven DDA1 phosphorylation promotes DNA repair and glioblastoma progression.

BACKGROUND: DDA1 is a protein involved in protein degradation, cell cycle regulation, and DNA damage repair. Although its expression varies across tumor types, the precise role of DDA1 in gliomagenesis remains unclear. METHODS: We investigated the function of DDA1 in multiple glioblastoma cell models using biochemical assays, phosphorylation analysis, subcellular localization studies, and integrated genomic and transcriptomic profiling to determine its signaling interactions and downstream effects. RESULTS: We identified a physical association between cytoplasmic DDA1 and Raptor, a core component of lysosome-associated mTORC1. Amino acid stimulation triggered phosphorylation of DDA1 at serine 33 promoting its nuclear translocation and involvement in DNA damage repair. Integrated transcriptomic analyses revealed that the mTORC1-DDA1S33-DNA repair axis regulates the expression of a subset of metabolic genes, including ENO2, CA12, and NMRK1. Functional assays further suggested that these genes contribute to the survival capacity of glioblastoma cells, particularly under DDA1-deficient conditions. Consistently, DDA1 deficiency markedly impaired glioblastoma growth and induced compensatory upregulation of metabolic activity. CONCLUSION: Our findings identify DDA1 as a previously unrecognized phosphorylation target downstream of mTORC1 and a critical mediator of the mTORC1 driven DNA damage response. Through its involvement in DNA repair and metabolic gene regulation, DDA1 appears to support glioblastoma progression, providing mechanistic insight into mTORC1 related gliomagenesis and suggesting potential therapeutic relevance.

Glioblastoma

Frataxin deficiency drives cardiac dysfunction and transcriptional dysregulation in Friedreich ataxia iPSC model.

Friedreich ataxia (FRDA) is a progressive neuromuscular degenerative disorder caused by GAA repeat expansions in the FXN gene, leading to frataxin deficiency and multisystem pathology. Cardiomyopathy is the leading cause of mortality in individuals with FRDA. To investigate the cellular and molecular mechanisms underlying FRDA-associated cardiac dysfunction, we employed induced pluripotent stem cell (iPSC) lines derived from three individuals with FRDA, each paired with an isogenic control line generated through CRISPR/Cas9-mediated excision of the pathogenic GAA repeat expansion. Correction of the mutation restored FXN expression to levels comparable to healthy donor iPSCs, and all lines differentiated efficiently into cardiomyocytes. Functional analysis revealed significant contractile abnormalities in FRDA cardiomyocytes and multicellular cardiac microtissues, including prolonged contraction and relaxation times and faster beating rates, consistent with clinical observations of cardiac contractile dysfunction. FRDA cardiomyocytes also exhibited pathological features such as increased cell size, irregular calcium transients, elevated mitochondrial reactive oxygen species levels, increased mitochondrial fission and increased cell death. These phenotypes were exacerbated by pathological levels of iron supplementation in culture media, highlighting the heightened sensitivity of frataxin-deficient cardiomyocytes to iron-induced metabolic stress. RNA sequencing revealed a distinct transcriptional profile associated with frataxin deficiency. MEG3 and PCDHGA10 were consistently dysregulated across all three FRDA-iPSC lines and may represent early molecular markers of FRDA cardiomyopathy. Functional interrogation of these candidates demonstrated that targeted silencing of MEG3 or PCDHGA10 in FRDA cardiomyocytes significantly reduced disease&#x2011;associated cell death without affecting FXN expression. Notably, PCDHGA10 silencing also normalized elevated mitochondrial reactive oxygen species, whereas MEG3 silencing did not, highlighting gene&#x2011;specific contributions to FRDA cardiomyocyte survival. Collectively, these findings identify MEG3 and PCDHGA10 as functionally relevant regulators of FRDA cardiomyocyte pathology.

Friedreich Ataxia

Comparative analysis of genomic variations among different Cdo1 paralogs for salinity-adaptation in oysters.

Under rapid climate change and anthropogenic activities, oysters, a global aquaculture species, are subjected to exacerbated culturing environments, especially for those living in in-shore estuarine species, such as Suminoe oysters Crassostrea ariakensis. This study aims to investigate the molecular mechanisms of salinity adaptation of C. ariakensis. We performed an expression genome-wide association study (eGWAS) to compare genetic regulation among 5 paralogous copies of a key salinity-related gene, cysteine dioxygenase 1 (Cdo1). A total of 40 significant eSNPs with 82 adjacent eGenes were identified in 2 copies (Cdo1_26639 and Cdo1_1666). We identified only trans-eSNPs for Cdo1_26639 and more cis-eSNPs for Cdo1_1666, and different eGenes for these 2 Cdo1 copies, which indicated that the expressional regulation of these paralogs may undergo distinct pathways. We identified 3 eGenes that exhibited identical expression patterns with Cdo1_26639 and Cdo1_1666, including 6-Pgdh, Trapp and tandem copy of Cdo1_27337. The expression correlation between Cdo1 copies and eGenes was enhanced under salinity stresses, suggesting the crucial role of eGenes in regulating Cdo1's expression in response to salinity changes. Our results provide comprehensive identification and comparison of eSNPs across different paralogous copies of one gene, along with insights into the molecular mechanisms underlying salinity tolerance, and genetic markers for breeding salinity-resistant oysters.

Animals

Whole-genome sequencing and analysis of the endophytic fungus Alternaria alternata Y-2 from Leymus chinensis.

To explore the genetic basis and functional potential of beneficial symbiosis between the endophytic fungus Alternaria alternata Y-2 and its host Leymus chinensis, we performed Illumina-based draft whole-genome sequencing and systematic bioinformatic analysis. Although this assembly does not reach telomere-to-telomere completeness, it provides high-quality gene-level information for gene prediction, functional annotation, carbohydrate-active enzyme (CAZyme) identification, and secondary metabolite biosynthetic gene cluster analysis. The final genome size of A. alternata Y-2 was 34,383,676&#xa0;bp with a GC content of 51.0%, containing 12,724 predicted protein-coding genes, 90 tRNAs, and 12 rRNAs. BUSCO assessment showed 98.9% completeness, supporting the high quality of this draft genome. A total of 12,627 genes were successfully annotated in the NCBI NR database, and 17,183 genes were functionally categorized using GO terms. In total, 448 CAZyme genes and 21 secondary metabolite biosynthetic gene clusters were identified, which are potentially involved in lignocellulose degradation, cellular redox homeostasis and biosynthesis of bioactive metabolites. Based on ITS sequence alignment, NR annotation, and phylogenetic analysis of single-copy orthologous genes, the strain was confidently identified as A. alternata. This study firstly reports the draft genome of an endophytic A. alternata strain derived from L. chinensis and provides valuable genetic resources for exploring the endophytic lifestyle, stress tolerance, and bioactive metabolite potential of this fungus.

Alternaria