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Biomedical subjects

Sijia Liu

Publications and source records attributed to Sijia Liu.

3 recordsLinked to original sources

Integrated Multi-Omics Analysis Reveals the Genetic Basis of Phenotypic Variation in Tibetan Sheep.

Body size is a key economic trait influencing the profitability of farmed animals. This study used genome-wide association studies (GWAS) to identify five single nucleotide polymorphisms (SNPs) significantly associated with body size in the Tibetan sheep population, advancing molecular breeding and providing a basis for genomic selection. These SNPs are located within five candidate genes. SNaPshot validated GWAS results, demonstrating significant correlations between candidate SNPs and body size traits in Tibetan sheep. Concurrently, hematoxylin and eosin staining, alongside muscle fiber analysis, confirmed pronounced morphological differences in muscle tissue between sheep of varying conformation. Therefore, transcriptome and proteomics were performed on the longest dorsi muscle from large and small Tibetan sheep of both sexes. The transcriptome, together with weighted gene co-expression network analysis (WGCNA), identified VEPH1 and PRKG1 as core genes regulating body characteristics in Tibetan sheep through their involvement in the PI3K-Akt signaling pathway and pathways related to fat deposition. The integrative analyses demonstrated significantly different expression of CARNS1 and CRYAB at both transcriptional and protein levels between the muscles of large- and small-sized Tibetan sheep of both sexes, suggesting their importance in body size traits by influencing muscle morphology. This study provides valuable genomic resources that advance sheep genetics research.

GWAS

GCH1, identified by a ferroptosis-related prognostic model, contributes to progression and drug resistance of esophageal cancer.

OBJECTIVE: Esophageal cancer has a poor prognosis and limited treatment options. Ferroptosis, an iron-dependent cell death pathway, is a promising therapeutic target; however, its significance in esophageal cancer remains largely unexplored. Here, we investigated the prognostic significance of ferroptosis-related genes in esophageal cancer and identified a key functional regulator that may serve as a therapeutic target. METHODS: We analyzed ferroptosis-related gene expression profiles with The Cancer Genome Atlas-Esophageal Carcinoma (TCGA-ESCA) cohort and constructed a prognostic risk model using LASSO Cox regression analysis. Among the genes in this model, GTP cyclohydrolase 1 (GCH1) was selected for functional investigation, based on its established role in antioxidant defense. Subsequently, in vitro experiments were performed to assess the effects of GCH1 knockdown on cell proliferation, migration, clonogenicity, and ferroptosis-related biochemical indicators. The role of GCH1 in antitumor immunity was evaluated through co-culture of esophageal cancer cells with activated T cells, and drug sensitivity was assessed using cytotoxicity assays. RESULTS: A prognostic model consisting of nine ferroptosis-related genes (STC2, TRIB3, HMGB3, CXCL8, GCH1, PARP10, APOE, MTIM, and GPER1) with reliable risk stratification was constructed. The prognostic model could reflect the differences in drug responses and immune cell infiltration. GCH1 knockdown suppressed esophageal cancer cell proliferation, migration, and clonogenicity. Furthermore, GCH1 knockdown increased the intracellular levels of reactive oxygen species, lipid peroxidation, and ferrous iron (Fe2+). Co-culture assays demonstrated that GCH1 knockdown in tumor cells increased the production of granzyme B and interferon-γ by CD8+ T cells. Moreover, GCH1 silencing sensitized esophageal cancer cells to both sorafenib and cisplatin. CONCLUSIONS: This study established a ferroptosis-related prognostic model for esophageal cancer and identified GCH1 as a critical regulator that contributes to esophageal cancer progression and drug resistance. These findings suggest that targeting GCH1 may be a promising strategy to improve drug sensitivity and clinical outcomes in esophageal cancer.

Esophageal cancer

ATF4-histone 2-hydroxyisobutyrylation feedback loop drives sepsis-induced inflammation.

BACKGROUND AND PURPOSE: The role and mechanisms of lysine 2-hydroxyisobutyrylation (Khib) in the acute inflammatory phase of sepsis remain unclear. We investigated the function and underlying mechanisms of histone H4 lysine 5 2-hydroxyisobutyrylation (H4K5-hib) in sepsis-induced inflammation in vivo and in vitro. EXPERIMENTAL APPROACH: Acute sepsis was induced by caecal ligation and puncture (CLP) in mice, and inflammatory responses were modelled in lipopolysaccharide (LPS)-stimulated macrophages. CUT&Tag-seq was used to identify genomic targets associated with H4K5-hib and activating transcription factor 4 (ATF4). Immunofluorescence, Western blotting, qPCR, dual-luciferase assays, and ELISA were performed to investigate the underlying mechanisms. KEY RESULTS: H4K5-hib levels were increased in macrophages during the acute inflammatory phase of sepsis. LPS stimulation enhanced H4K5-hib enrichment at the ATF4 promoter, thereby promoting ATF4 transcription. Inhibition of EP300-mediated 2-hydroxyisobutyrylation or mutation of H4K5 abolished ATF4 activation. Increased H4K5-hib activated the ATF4/NLRP3 signalling axis, promoting inflammasome assembly and amplifying inflammatory responses. ATF4 directly bound to the EP300 promoter and enhanced its transcription, forming a positive feedback loop that further increased H4K5-hib levels. In CLP-induced sepsis, pharmacological inhibition of EP300 or ATF4 reduced H4K5-hib levels and suppressed NLRP3 inflammasome activation. CONCLUSION AND IMPLICATIONS: These findings reveal a previously unrecognized epigenetic mechanism underlying sepsis-induced inflammation and identify the EP300/ATF4/H4K5-hib positive feedback loop as a potential therapeutic target for sepsis.

Animals