Immortalized Human Kidney Fibroblasts-SV40

Bulk Transcriptome Analysis of Conditionally Immortalized Human Kidney CD10⁺ PTECs and PDGFRΒ⁺ Fibroblasts

Cellular senescence is a major contributor to the pathogenesis of chronic kidney disease (CKD) especially in proximal tubule epithelial cells (PTECs) and fibroblasts. Current cellular models are often confounded by age and comorbidities and human kidney cell lines often poorly represent in vivo physiology due to cancer-like changes. The researchers aimed to establish a controllable conditionally immortalized human kidney cell model (doxycycline inducible SV40LT) for the purpose of accurately mimicking in vivo cellular behavior, mechanistic exploration of senescence-specific processes, and verifying clinical relevance of senescence in CKD progression through ex vivo and in vivo correlations.

They performed bulk RNAseq to characterize transcriptional changes upon doxycycline withdrawal that induces cellular senescence. Principal component analysis (PCA) showed separation by cell identity (epithelial vs mesenchymal) and senescence status (Fig. 1C). Validation with single-cell data from Kidney Precision Medicine Project (KPMP) supported our CD10⁺ PTECs and PDGFRβ⁺ The fibroblasts were very much like the in vivo cells, proximal tubule cells and interstitial fibroblasts respectively (Fig. 1D-G).

Senescent cells exhibited hallmark features such as increased NF-κB, inflammatory response and p53 signaling, while pathways of cell proliferation were decreased (Fig. 1H, I). Key markers of senescence (CDKN1A, LMNB1) and genes involved in inflammation, fibrosis and chemotaxis were concordantly changed in both cell lines (Fig. 1J, K). KEGG analysis further confirmed this common senescence signature by showing activated TNF-α/p53 signaling pathway and inhibited cell cycle pathways (Fig. 1L-N).