Protein-centric omics analysis reveals circulating complements linked to non-viral liver diseases as potential therapeutic targets

Hepatocyte nuclear factor 4α is a critical factor for the production of complement components in the liver

The complement system plays an important role in biological defense as an effector to eliminate microorganisms that invade an organism and it is composed of more than 50 proteins, most of which are produced in the liver. Of these proteins, the mRNA expression of C3 and Cfb is known to be positively regulated by the nuclear receptor HNF4α. To investigate whether HNF4α regulates the complement system, we analyzed the hepatic expression of genes involved in the complement activation pathway and membrane attack complex (MAC) formation within the complement system using liver-specific Hnf4a-null mice (Hnf4aΔHep mice) and tamoxifen-induced liver-specific Hnf4a-null mice (Hnf4af/f;AlbERT2cre mice). We found that hepatic expression of many complement genes including C8a, C8b, C8g, and C9 that are involved in formation of the MAC was markedly decreased in Hnf4aΔHep mice and Hnf4af/f;AlbERT2cre mice. Furthermore, expression of C8A, C8B, and C8G was also decreased in human hepatoma cell lines in which the expression of HNF4α was suppressed, and expression of C8G and C9 was induced in a human immortalized hepatocyte cell line with forced expression of HNF4α. Transactivation of C8g and C9 was dependent on HNF4α expression of HNF4α binding sites, indicating that C8g and C9 are novel target genes of HNF4α. The results suggest that hepatic HNF4α plays an important role in regulation of the complement system, mainly MAC formation.

Constructing a disulfidptosis-related prognostic signature of hepatocellular carcinoma based on single-cell sequencing and weighted co-expression network analysis

Hepatocellular carcinoma (HCC) ranks as the second leading cause of cancer-related deaths globally. Disulfidptosis is a newly identified form of regulated cell death that is induced by glucose starvation. However, the clinical prognostic characteristics of disulfidptosis-associated genes in HCC remain poorly understood. We conducted an analysis of the single-cell datasets GSE149614 and performed weighted co-expression network analysis (WGCNA) on the Cancer Genome Atlas (TCGA) datasets to identify the genes related to disulfidptosis. A prognostic model was constructed using univariate COX and Lasso regression. Survival analysis, immune microenvironment analysis, and mutation analysis were performed. Additionally, a nomogram associated with disulfidptosis-related signature was constructed to identify the prognosis of HCC patients. Patients with HCC in the TCGA and GSE14520 datasets were categorized using a disulfidptosis-related model, revealing significant differences in survival times between the high- and low-disulfidptosis groups. High-disulfidptosis patients exhibited increased expression of immune checkpoint-related genes, implying that immunotherapy and certain chemotherapies may be beneficial for them. Meanwhile, the ROC and decision curves analysis (DCA) indicated that the nomogram has satisfying prognostic efficacy. Moreover, the experimental results of GATM in this prognostic model indicated that GATM is low expressed in HCC tissues, and GATM knockdown promotes the proliferation and migration of HCC cells. By analyzing single-cell and bulk multi-omics sequencing data, we developed a prognostic signature related to disulfidptosis and explored the relationship between high- and low-disulfidptosis groups in HCC. This study offers a novel reference for gaining a deeper understanding of the role of disulfidptosis in HCC.