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Biomedical subjects

Dan Liu

Publications and source records attributed to Dan Liu.

7 recordsLinked to original sources

Intratumoral PD-1+LAG-3+CD8+ T cells are associated with improved prognosis in gastric cancer.

PURPOSE: PD-1 and LAG-3 are frequently used as markers of T cell exhaustion, yet the prognostic relevance and phenotypic characteristics of PD-1+LAG-3+CD8+ T cells in gastric cancer (GC) remain poorly defined. This study aimed to investigate their association with clinical outcomes and characterize their immune characteristics across independent GC cohorts. METHODS: Four independent GC cohorts were analyzed: the Zhongshan Hospital cohort (ZSGC, n = 298), The Cancer Genome Atlas cohort (TCGA, n = 371), an Immune Checkpoint Blockade cohort (ICB, n = 45), and the Yonsei cohort (n = 433). Intratumoral PD-1+LAG-3+CD8+ T cell infiltration was quantified by immunofluorescence staining and transcriptomic gene signature scoring. Survival analysis was performed using Kaplan-Meier estimation and multivariate Cox regression. Functional characterization was performed by flow cytometry on resected GC tissue. The immune microenvironment composition was evaluated using computational analyses. RESULTS: PD-1+LAG-3+CD8+ T cells were enriched within tumors compared to adjacent normal mucosa, and their infiltration correlated with advanced tumor stage, poor differentiation, microsatellite instability, and Epstein-Barr virus (EBV)-positive molecular subtypes. High intratumoral infiltration was significantly associated with improved overall survival in both the ZSGC and TCGA cohorts, whereas single-positive PD-1+CD8+ or LAG-3+CD8+ T cells showed no such association. In the ICB cohort, higher infiltration was associated with a higher response rate to pembrolizumab. Intratumoral PD-1+LAG-3+CD8+ T cells exhibit an activated phenotype characterized by increased expression of CD137, IFN-γ, perforin, and CXCL13, along with elevated TCF7 and lower PD-1 levels, suggesting a tumor-reactive, pre-exhausted state. High infiltration was further associated with an immune-active tumor microenvironment. CONCLUSIONS: High intratumoral infiltration of PD-1+LAG-3+CD8+ T cells is associated with favorable prognosis and an immune-active microenvironment in GC. These cells display phenotypic features consistent with a pre-exhausted state and may serve as independent prognostic biomarkers and candidate predictive biomarkers for immunotherapy stratification.

Humans

Population structure and antibiotic resistance of Salmonella isolates from diseased poultry in Jiangxi Province, China.

Salmonella poses a significant threat to human and animal health. However, the relationship among population diversity, antibiotic resistance, and infection risk remains largely unexplored. In this study, 69 Salmonella strains were isolated from diseased poultry in Jiangxi Province from 2021 to 2024. Using whole-genome sequencing, serotype prediction, MLST, virulence and resistance gene analysis, antibiotic susceptibility testing, and mobile genetic element annotation, we characterized the diversity, resistance profiles, and transmission mechanisms of these strains. The results showed high diversity, with Salmonella enterica subsp. enterica serovar Typhimurium (>60%) and ST19 (62.31%) as the dominant serovar and sequence type, respectively. Several avian isolates were genomically similar to human isolates, indicating potential zoonotic risk. All strains harbored conserved core virulence modules, whereas accessory modules (e.g., cdtB, astA, pefA) varied and may affect pathogenicity. The multidrug resistance rate was 97.1%, with 100% resistance to erythromycin, tilmicosin and tiamulin, and resistance rates of 91.3%, 84.1%, and 71.0% to sulfonamides, enrofloxacin, and ceftiofur, respectively. Sixty-eight resistance genes were identified. Highly conserved antimicrobial resistance gene (ARG) modules (e.g., sul2-aph(3″)-Ib-aph(6')-Id-tet(A)) were shared between chromosomes and plasmids and were flanked by mobile elements such as Tn3 and IS3. Genomic islands (GIs) and plasmids in some strains carried resistance gene clusters highly homologous to those in pathogens from humans, pigs, and chickens, suggesting active horizontal transfer of resistance genes across hosts. This study revealed high diversity, prevalent multidrug resistance, and active horizontal transfer of resistance genes in avian-derived Salmonella from Jiangxi Province, emphasizing the need for cross-host resistance monitoring and antibiotic management within the 'One Health' framework.

Horizontal gene transfer

Angiotensin II regulates anxiety and social-affective top-down and bottom-up attention control in a sex-dependent manner.

BACKGROUND: The renin-angiotensin system (RAS) has been increasingly recognized as potent modulator of cognitive and affective functions, with angiotensin II type 1 receptor (AT1R) antagonists emerging as repurposing candidate for anxiety and stress-related disorders. However, it remains unclear whether transient AT1R blockade modulates emotional attentional control and whether these effects are sex-dependent. METHODS: We conducted a preregistered, randomized, double-blind, placebo-controlled pharmacological eye-tracking study in 79 healthy adults (males and females) and determined effects of transient AT1R blockade via losartan (50 mg) on emotional attention control using a validated anti-saccade paradigm with social (emotional faces) and non-social stimuli. Treatment effects on state anxiety and oculomotor responses were characterized using traditional metrics and a novel trial-history informed dynamic control framework. RESULTS: Losartan reduced state anxiety irrespective of sex but induced sexually dimorphic effects on attentional control. In females, losartan enhanced performance by reducing endpoint error without altering latency. Conversely, in males, losartan increased endpoint error and prolonged latency of the first correct saccade. Trial-history analyses revealed losartan reduced error probabilities following errors and repeat trials in both sexes. Yet, following correct trials, females receiving losartan maintained lower error probabilities, while males exhibited higher errors, potentially reflecting failure to disengage from effortful control. CONCLUSIONS: The RAS modulates anxiety and attentional control, the latter sex-dependently. AT1R blockade reconfigures attentional processing and adaptive control, suggesting sex-specific therapeutic potential in disorders characterized by excessive anxiety and attentional dysregulation. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov; https://clinicaltrials.gov/;NCT06329050.

Humans

Near Full-Length Genome Characterization of a Novel Second-Generation HIV-1 CRF01_AE/CRF07_BC Recombinant Identified in an MSM Individual in Guizhou, China.

The cocirculation of CRF01_AE and CRF07_BC among men who have sex with men (MSM) in China may facilitate the emergence of genetically complex HIV-1 recombinants. Here, we identified and characterized a novel second-generation HIV-1 CRF01_AE/CRF07_BC recombinant, designated GY0192, from a 25-year-old MSM individual in Guiyang, Guizhou Province, southwest China, using near full-length genome (NFLG) analysis. Recombination analyses identified four breakpoints at HXB2 positions 3,125, 5,687, 6,375, and 9,176, generating a distinct five-segment mosaic genome. Subregion phylogenetic analyses showed that the two CRF01_AE-derived fragments clustered with the CRF01_AE cluster 5 lineage, while all three CRF07_BC-derived fragments grouped with CRF07_BC lineages frequently circulating among MSM in China, indicating that both parental components of GY0192 were phylogenetically related to lineages frequently reported among MSM populations in China. The virus was also predicted to be CCR5-tropic, adding epidemiological relevance because CCR5-tropic viruses are commonly involved in transmission and early infection. Together, these findings identify GY0192 as a distinct CRF01_AE/CRF07_BC mosaic and suggest that cocirculating MSM-associated HIV-1 lineages may provide opportunities for interlineage recombination. This case expands the known spectrum of CRF01_AE/CRF07_BC recombinants in Guizhou and underscores the value of NFLG-based surveillance for detecting underrecognized HIV-1 genetic complexity in southwest China.

Humans

Mov10 mitigates hematopoietic stem cell exhaustion under stress by modulating the Camp-mediated inflammatory pathway.

The integrity of hematopoietic stem cell (HSC) function is crucial for robust hematopoietic regeneration following stress. Inflammatory responses are pivotal drivers of HSC stress response, yet the precise modulation of inflammatory pathways remains incompletely defined. In this study, we identify the RNA helicase Mov10 as a negative regulator of stress-induced inflammatory pathways in HSC. Our study indicates that Mov10, which is critically required for HSC maintenance, is highly expressed in HSC, and its loss adversely affects HSC fitness and survival during hematopoietic stress induced by bone marrow transplantation and irradiation (IR). Mechanistically, Mov10 mitigates excessive inflammatory activation to sustain HSC functional integrity during hematopoietic stress, primarily by enhancing the translation of CAMP, which inhibits the interaction between TNF-α and its receptor TNFR1 and suppresses NF-κB activation. Overall, our results imply that Mov10 plays a critical role in averting functional failure of hematopoiesis under stress, presenting viable paths for the therapeutic intervention of relevant diseases.

Camp

UHRF1 deficiency exacerbates intestinal inflammation by epigenetic modulation of NPY1R gene methylation.

Epigenetic modifications play a crucial role in the pathogenesis of inflammatory bowel disease (IBD) by mediating gene-environment interactions. We previously showed that UHRF1, a central regulator of DNA methylation, contributes to cancer progression; however, its function in IBD remains poorly understood. Here, we revealed that UHRF1 was frequently reduced in inflamed tissues of patients with IBD and that its deficiency exacerbated intestinal epithelial cell (IEC) damage. Through a multilevel approach incorporating human cell models and an intestinal epithelial-specific Uhrf1-KO mouse model, we established UHRF1 as a key mitigator of IBD progression. Mechanistically, UHRF1 bound to the NPY1R promoter, promoted its methylation, and led to transcriptional suppression. The NPY1R upregulation resulting from UHRF1 deficiency attenuated cAMP/PKA/CREB signaling in IECs, thereby enhancing NF-κB activation and subsequent proinflammatory responses, which compromised intestinal epithelial barrier integrity. Furthermore, we identified miR-141 as a negative regulator of NPY1R, highlighting its potential as a therapeutic agent. Collectively, our results identified the UHRF1/NPY1R regulatory axis as a critical epigenetic mechanism in intestinal inflammation and underscored its dual promise for IBD diagnostics and therapy.

Animals

Association analysis between an epigenetic alcohol risk score and blood pressure.

BACKGROUND: Epigenome-wide association studies have identified multiple DNA methylation sites (CpGs) associated with alcohol consumption, an important lifestyle risk factor for cardiovascular diseases. This study aimed to test the hypothesis that an alcohol consumption epigenetic risk score (ERS) is associated with blood pressure (BP) traits. RESULTS: We implemented an ERS based on a previously reported epigenetic signature of 144 alcohol-associated CpGs in meta-analysis of participants of European ancestry. We found a one-unit increment of ERS was associated with eleven drinks of alcohol consumed per day, on average, across several cohorts (p&#x2009;<&#x2009;0.0001). We examined the association of the ERS with systolic blood pressure (SBP), diastolic blood pressure (DBP), and hypertension (HTN) in 3,898 Framingham Heart Study (FHS) participants. Cross-sectional analyses in FHS revealed that a one-unit increment of the ERS was associated with 1.93&#xa0;mm Hg higher SBP (p&#x2009;=&#x2009;4.64E-07), 0.68&#xa0;mm Hg higher DBP (p&#x2009;=&#x2009;0.006), and an odds ratio of 1.78 for HTN (p&#x2009;<&#x2009;2E-16). Meta-analysis of the cross-sectional association of the ERS with BP traits in eight independent external cohorts (n&#x2009;=&#x2009;11,544) showed similar relationships with BP levels, i.e., a one-unit increase in ERS was associated with 0.74&#xa0;mm Hg (p&#x2009;=&#x2009;0.002) higher SBP and 0.50&#xa0;mm Hg (p&#x2009;=&#x2009;0.0006) higher DBP, but not with HTN. Longitudinal analyses in FHS (n&#x2009;=&#x2009;3260) and five independent external cohorts (n&#x2009;=&#x2009;4021) showed that the baseline ERS was not associated with a change in BP over time or with incident HTN. CONCLUSIONS: Our findings demonstrate that the ERS has potential clinical utility in assessing lifestyle factors related to cardiovascular risk, especially when self-reported behavioral data (e.g., alcohol consumption) are unreliable or unavailable.

Humans