ANXA1 is identified as a key gene associated with high risk and T cell infiltration in primary sclerosing cholangitis

EEF1A2 identified as a hub gene associated with the severity of metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a prevalent chronic liver disease that ranges from metabolic dysfunction-associated steatotic liver (MASL) to metabolic dysfunction-associated steatohepatitis (MASH), and may eventually progress to cirrhosis and hepatocellular carcinoma (HCC). The underlying mechanism of MASLD remains incompletely understood. This study aimed to identify key gene implicated in MASLD pathogenesis and validate its correlation with disease severity through an integration of bioinformatics and experimental approaches. Liver transcriptome data from MASLD patients were obtained from the Gene Expression Omnibus (GEO) database. A diet-induced MASLD mouse model was developed, and liver RNA-sequencing was performed. Liver specimens and clinical data from patients were collected for further analysis. A total of 120 differentially expressed genes (DEGs) were shared between datasets GSE89632 and GSE213621, with functional enrichment in inflammatory, metabolic, and cell cycle-related pathways. Protein-protein interaction (PPI) network analysis identified three modules associated with MASLD, with the cell cycle-related module being the most notable. EEF1A2 was identified as a novel hub gene and revealed to be elevated with MASLD progression through dataset analysis. EEF1A2 was confirmed to be highly expressed in the livers of both MASLD mouse models and patients. Moreover, the increased expression of EEF1A2 in MASH was positively correlated with higher serum alanine aminotransferase (ALT), alanine aminotransferase (AST), total cholesterol (TC), and body mass index (BMI). In conclusion, EEF1A2 is a novel hub gene significantly associated with MASLD severity and is a promising biomarker and therapeutic target for MASLD.

Causality of immune cells on primary sclerosing cholangitis: a bidirectional two-sample Mendelian randomization study

Background

Observational studies have indicated that immune dysregulation in primary sclerosing cholangitis (PSC) primarily involves intestinal-derived immune cells. However, the causal relationship between peripheral blood immune cells and PSC remains insufficiently understood.

Methods

A bidirectional two-sample Mendelian randomization (MR) analysis was implemented to determine the causal effect between PBC and 731 immune cells. All datasets were extracted from a publicly available genetic database. The standard inverse variance weighted (IVW) method was selected as the main method for the causality analysis. Cochran's Q statistics and MR-Egger intercept were performed to evaluate heterogeneity and pleiotropy.

Results

In forward MR analysis, the expression ratios of CD11c on CD62L+ myeloid DC (OR = 1.136, 95% CI = 1.032-1.250, p = 0.009) and CD62L-myeloid DC AC (OR = 1.267, 95% CI = 1.086-1.477, p = 0.003) were correlated with a higher risk of PSC. Each one standard deviation increase of CD28 on resting regulatory T cells (Treg) (OR = 0.724, 95% CI = 0.630-0.833, p < 0.001) and CD3 on secreting Treg (OR = 0.893, 95% CI = 0.823-0.969, p = 0.007) negatively associated with the risk of PSC. In reverse MR analysis, PSC was identified with a genetic causal effect on EM CD8+ T cell AC, CD8+ T cell AC, CD28- CD127- CD25++ CD8+ T cell AC, CD28- CD25++ CD8+ T cell AC, CD28- CD8+ T cell/CD8+ T cell, CD28- CD8+ T cell AC, and CD45 RA- CD28- CD8+ T cell AC.

Conclusion

Our study indicated the evidence of causal effects between PSC and immune cells, which may provide a potential foundation for future diagnosis and treatment of PSC.

The pro-resolving mediator, annexin A1 regulates blood pressure, and age-associated changes in cardiovascular function and remodeling

Aging is associated with chronic, low-level inflammation which may contribute to cardiovascular pathologies such as hypertension and atherosclerosis. This chronic inflammation may be opposed by endogenous mechanisms to limit inflammation, for example, by the actions of annexin A1 (ANXA1), an endogenous glucocorticoid-regulated protein that has anti-inflammatory and pro-resolving activity. We hypothesized the pro-resolving mediator ANXA1 protects against age-induced changes in blood pressure (BP), cardiovascular structure and function, and cardiac senescence. BP was measured monthly in conscious mature (4-month) and middle-aged (12-month) ANXA1-deficient (ANXA1-/- ) and wild-type C57BL/6 mice. Body composition was measured using EchoMRI, and both cardiac and vascular function using ultrasound imaging. Cardiac hypertrophy, fibrosis and senescence, vascular fibrosis, elastin, and calcification were assessed histologically. Gene expression relevant to structural remodeling, inflammation, and cardiomyocyte senescence were also quantified. In C57BL/6 mice, progression from 4 to 12 months of age did not affect the majority of cardiovascular parameters measured, with the exception of mild cardiac hypertrophy, vascular calcium, and collagen deposition. Interestingly, ANXA1-/- mice exhibited higher BP, regardless of age. Additionally, age progression had a marked impact in ANXA1-/- mice, with markedly augmented vascular remodeling, impaired vascular distensibility, and body composition. Consistent with vascular dysfunction, cardiac dysfunction, and hypertrophy were also evident, together with markers of senescence and inflammation. These findings suggest that endogenous ANXA1 plays a critical role in regulating BP, cardiovascular function, and remodeling and delays cardiac senescence. Our findings support the development of novel ANXA1-based therapies to prevent age-related cardiovascular pathologies.