Bioinformatics-based analysis of the roles of basement membrane-related gene AGRN in systemic lupus erythematosus and pan-cancer development.

Introduction: Systemic lupus erythematosus (SLE) is an autoimmune disease involving many systems and organs, and individuals with SLE exhibit unique cancer risk characteristics. The significance of the basement membrane (BM) in the occurrence and progression of human autoimmune diseases and tumors has been established through research. However, the roles of BM-related genes and their protein expression mechanisms in the pathogenesis of SLE and pan-cancer development has not been elucidated. Methods: In this study, we applied bioinformatics methods to perform differential expression analysis of BM-related genes in datasets from SLE patients. We utilized LASSO logistic regression, SVM-RFE, and RandomForest to screen for feature genes and construct a diagnosis model for SLE. In order to attain a comprehensive comprehension of the biological functionalities of the feature genes, we conducted GSEA analysis, ROC analysis, and computed levels of immune cell infiltration. Finally, we sourced pan-cancer expression profiles from the TCGA and GTEx databases and performed pan-cancer analysis. Results: We screened six feature genes (AGRN, PHF13, SPOCK2, TGFBI, COL4A3, and COLQ) to construct an SLE diagnostic model. Immune infiltration analysis showed a significant correlation between AGRN and immune cell functions such as parainflammation and type I IFN response. After further gene expression validation, we finally selected AGRN for pan-cancer analysis. The results showed that AGRN's expression level varied according to distinct tumor types and was closely correlated with some tumor patients' prognosis, immune cell infiltration, and other indicators. Discussion: In conclusion, BM-related genes play a pivotal role in the pathogenesis of SLE, and AGRN shows immense promise as a target in SLE and the progression of multiple tumors.

Probucol decreases homocysteine-stimulated CRP production in rat aortic smooth muscle cells via regulating HO-1/NADPH oxidase/ROS/p38 pathway.

The elevated homocysteine level is an independent risk factor for atherosclerosis, which is characterized as a chronic inflammatory disease associated with oxidative stress. We have confirmed that homocysteine can stimulate the production of C-reactive protein (CRP) in rat aortic smooth muscle cells (RASMCs). In the present study, we investigated the role of probucol in homocysteine-induced CRP expression in cultured RASMCs and high-methionine-diet-induced hyperhomocysteinemic rats. The results showed that probucol decreased homocysteine-induced CRP mRNA and protein expression in RASMCs in a concentration-dependent manner. In addition, the animal experiment showed that probucol not only inhibited CRP expression in the vessel wall but also reduced the circulating CRP level in hyperhomocysteinemic rats. Further investigations revealed that probucol markedly increased heme oxygenase-1 activity, suppressed nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity, diminished superoxide anion generation, and decreased p38 phosphorylation in RASMCs and hyperhomocysteinemic rat aorta. These data demonstrate that probucol can inhibit homocysteine-induced CRP generation by interfering with the NADPH oxidase/p38 signal pathway in RASMCs, which will provide new evidence for the anti-inflammatory and anti-atherosclerotic effects of probucol.

Simvastatin inhibits homocysteine-induced CRP generation via interfering with the ROS-p38/ERK1/2 signal pathway in rat vascular smooth muscle cells.

Inflammation plays a pivotal role throughout the formation and progression of atherosclerosis. As the most representative inflammatory marker, C-reactive protein (CRP) directly participates in the initiation and development of atherosclerosis. The elevated homocysteine (Hcy) level in plasma is an independent risk factor for atherosclerosis. We previously reported that Hcy produces a pro-inflammatory effect by stimulating CRP expression in vascular smooth muscle cells (VSMCs). The present study observed the effect of simvastatin on Hcy-induced CRP expression in VSMCs and the molecular mechanisms. The in vitro experiments revealed that pretreatment of VSMCs with simvastatin decreased Hcy-induced mRNA and protein expression of CRP in a concentration-dependent fashion. The in vivo results showed that simvastatin not only inhibited CRP expression in the vessel walls in mRNA and protein levels, but also reduced the circulating CRP level in hyperhomocysteinemic rats. Further experiments displayed that simvastatin reduced Hcy-induced reactive oxygen species (ROS) generation, ameliorated Hcy-activated phosphorylations of ERK1/2 and p38, and antagonized Hcy-downregulated peroxisome proliferator-activated receptor gamma expression in VSMCs. These data demonstrate that simvastatin is able to inhibit Hcy-induced CRP generation in VSMCs so to relieve the vascular inflammatory response via interfering with the ROS-MAPK signal pathway. The present results provide new evidence for understanding of the potential anti-inflammatory and anti-atherosclerotic effects of simvastatin. As the high level of Hcy in plasma is related to atherosclerosis formation and mediates cardiovascular risk, our findings emphasize the importance and necessity of therapy with statins for hyperhomocysteinemia in atherosclerosis.