Circadian rhythm modulation and immune landscape heterogeneity in hypertensive nephropathy: A comprehensive molecular...

The objective of this study was to unveil the interplay between circadian rhythms (CR) and hypertensive nephropathy (HTN) by investigating genes, pathways, and molecular functions and the correlation between CR and HTN's immune landscape through bioinformatic approaches. Key genes associated with CR in HTN were screened through an integrated analysis of GEO data, employing consensus clustering and machine learning approaches (Generalized Linear Models (GLM), Random Forest (RF), and Support Vector Machine (SVM)). CIBERSORT, ESTIMATE and ssGSEA algorithm were used to assess the infiltration of immune cells between HTN and control groups and in three distinct CR phenotypes of HTN. Functional analyses including GO and KEGG were conducted to elucidate the underlying mechanisms. The DGIdb website is utilized for predicting potential effective therapeutic drugs targeting CR genes closely linked to HTN. We obtained 45 differentially expressed CR-related genes and these genes are mainly involving signaling pathways such as rhythmic process, circadian rhythm and TGF-beta signaling pathway. Three CR related genes (CCL5, ATF3 and NR4A1) were identified to construct a diagnostic model and have a good performance in diagnosis of HTN and patients with HTN were clustered into three subgroups by consensus clustering according to these genes. Analysis of immune infiltration revealed immune heterogeneity between HTN patients and controls and between the three key CR-related gene clusters of patients with HTN. Furthermore, three CR related genes clusters revealing distinct ESTIMATE Score, Immune Score, Stromal Score heterogeneity with p value < 0.05. Meanwhile, spearman analysis showed CCL5 has a strong correlation different immune cells infiltration, especially NK activated cells (p < 0.001), ATF3 has a correlation with NK resting cells (p = 0.029) and NR4A1 has the most significant correlation with activated T CD4 memory cells infiltration (p = 0.020). The potential therapeutic drug predictions for three CR genes indicate that ATF3 and NR4A1 may harbor potential effective treatment options. Our findings suggest an association between circadian rhythm disruption and altered immune landscape in HTN, highlighting the potential role of CR-related genes in disease heterogeneity. The genes CCL5, ATF3, and NR4A1-which are implicated in circadian regulatory networks - may serve as candidate biomarkers and provide new directions for diagnostic and therapeutic strategies in HTN. Further experimental validation is required to confirm their functional roles and clinical significance .