Defining the role of TFEB and evaluating its pharmacological manipulation in kidney remodeling and disease progression in TSC.

Tuberous sclerosis complex (TSC) is a genetic disorder that can cause kidney cysts and tumors and is a major cause of illness in adults with TSC. Current treatments do not fully prevent kidney disease progression, and we still do not understand all the mechanisms that drive tissue remodeling in the kidney. In our previous work we created human “mini-kidneys” (kidney organoids) carrying loss of the TSC2 gene and found disease-like changes, including cyst formation, increased mTOR signaling, and strong activation of TFEB/TFE3, factors that regulate cellular recycling pathways. We also observed that mutant organoids release signals that can increase blood-vessel features in healthy organoids, suggesting that diseased cells can influence neighboring cells through intercellular communication. This project will address three connected questions. First, we will identify the proteins and extracellular vesicle signals released by TSC2-mutant organoids that drive kidney remodeling in surrounding cells. We will use proteomics to compare the total protein content of organoids with what they release into the medium and into extracellular vesicles, and we will test the biological effects of these signals in transfer and co-culture assays. Second, we will test whether activating TFEB specifically in tubular cells of healthy organoids is sufficient to reproduce key TSC-like remodeling features and generate similar secreted signals. Third, we will evaluate how eltrombopag, a drug that inhibits TFEB transcriptional activity, modifies TFEB-dependent programs and remodeling phenotypes in organoids, defining treatment timing, durability, and compartment-level effects. The expected outcome is a clearer understanding of how kidney disease progresses in TSC and a set of biomarkers and mechanistic targets to guide future therapeutic strategies.