DNAJA3 regulates B cell development and immune function

Analysis of the TID-I and TID-L Splice Variants' Expression Profile under In Vitro Differentiation of Human Mesenchymal Bone Marrow Cells into Osteoblasts

Bone formation is a complex process regulated by a variety of pathways that are not yet fully understood. One of the proteins involved in multiple osteogenic pathways is TID (DNAJA3). The aim of this work was to study the association of TID with osteogenesis. Therefore, the expression profiles of the TID splice variants (TID-L, TID-I) and their protein products were analyzed during the proliferation and differentiation of bone marrow mesenchymal stromal cells (B-MSCs) into osteoblasts. As the reference, the hFOB1.19 cell line was used. The phenotype of B-MSCs was confirmed by the presence of CD73, CD90, and CD105 surface antigens on ~97% of cells. The osteoblast phenotype was confirmed by increased alkaline phosphatase activity, calcium deposition, and expression of ALPL and SPP1. The effect of silencing the TID gene on the expression of ALPL and SPP1 was also investigated. The TID proteins and the expression of TID splice variants were detected. After differentiation, the expression of TID-L and TID-I increased 5-fold and 3.7-fold, respectively, while their silencing resulted in increased expression of SPP1. Three days after transfection, the expression of SPP1 increased 7.6-fold and 5.6-fold in B-MSCs and differentiating cells, respectively. Our preliminary study demonstrated that the expression of TID-L and TID-I changes under differentiation of B-MSCs into osteoblasts and may influence the expression of SPP1. However, for better understanding the functional association of these results with the relevant osteogenic pathways, further studies are needed.

Construction of a 12-gene prognostic model for colorectal cancer based on heat shock protein-related genes

Some heat shock proteins (HSPs) have been shown to influence tumor prognosis, but their prognostic significance in colorectal cancer (CRC) remains unclear. This study explored the prognostic significance of HSP-related genes in CRC. Transcriptional data and clinical information of CRC patients were obtained from The Cancer Genome Atlas (TCGA) database, and a literature search was conducted to identify HSP-related genes. Using Least Absolute Selection and Shrinkage Operator (LASSO) regression and univariate/multivariate Cox regression analyses, 12 HSP-related genes demonstrating significant associations with CRC survival were successfully identified and employed to formulate a predictive risk score model. The efficacy and precision of this model were validated utilizing TCGA and Gene Expression Omnibus (GEO) datasets, demonstrating its reliability in CRC prognosis prediction. gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed significant disparities between high- and low-risk groups in chromatin remodeling biological functions and neutrophil extracellular trap formation pathways. Single sample gene set enrichment analysis (ssGSEA) further revealed differences in immune cell types and immune functional status between the two risk groups. Differential analysis showed higher expression of immune checkpoints within the low-risk group, while the high-risk group exhibited notably higher Tumor Immune Dysfunction and Exclusion (TIDE) scores. Additionally, we predicted the sensitivity of different prognosis risk patients to various drugs, providing potential drug choices for tailored treatment. Combined, our study successfully crafted a novel CRC prognostic model that can effectively predict patient survival, immune landscape, and treatment response, providing important support and guidance for CRC patient prognosis.

A genetic basis of mitochondrial DNAJA3 in nonalcoholic steatohepatitis-related hepatocellular carcinoma

BACKGROUND AND AIMS

NAFLD is the most common form of liver disease worldwide, but only a subset of individuals with NAFLD may progress to NASH. While NASH is an important etiology of HCC, the underlying mechanisms responsible for the conversion of NAFLD to NASH and then to HCC are poorly understood. We aimed to identify genetic risk genes that drive NASH and NASH-related HCC.

APPROACH AND RESULTS

We searched genetic alleles among the 24 most significant alleles associated with body fat distribution from a genome-wide association study of 344,369 individuals and validated the top allele in 3 independent cohorts of American and European patients (N=1380) with NAFLD/NASH/HCC. We identified an rs3747579-TT variant significantly associated with NASH-related HCC and demonstrated that rs3747579 is expression quantitative trait loci of a mitochondrial DnaJ Heat Shock Protein Family (Hsp40) Member A3 ( DNAJA3 ). We also found that rs3747579-TT and a previously identified PNPLA3 as a functional variant of NAFLD to have significant additional interactions with NASH/HCC risk. Patients with HCC with rs3747579-TT had a reduced expression of DNAJA3 and had an unfavorable prognosis. Furthermore, mice with hepatocyte-specific Dnaja3 depletion developed NASH-dependent HCC either spontaneously under a normal diet or enhanced by diethylnitrosamine. Dnaja3 -deficient mice developed NASH/HCC characterized by significant mitochondrial dysfunction, which was accompanied by excessive lipid accumulation and inflammatory responses. The molecular features of NASH/HCC in the Dnaja3 -deficient mice were closely associated with human NASH/HCC.

CONCLUSIONS

We uncovered a genetic basis of DNAJA3 as a key player of NASH-related HCC.