Tsc Gene Locus Disruption and Differences in Renal Epithelial Extracellular Vesicles

Area of Science:

• Cell Biology
• Genetics
• Biochemistry

Background:

• Tuberous sclerosis complex (TSC) is a genetic disorder.
• Tsc2 mutations are linked to more severe TSC manifestations than Tsc1 mutations.
• The role of extracellular vesicles (EVs) in TSC pathogenesis is understudied.

Purpose of the Study:

• To comparatively analyze EVs from isogenic renal cells with different Tsc1 or Tsc2 gene statuses.
• To investigate if EVs modulate signaling pathways differently despite similar physical characteristics, contributing to TSC heterogeneity.

Main Methods:

• CRISPR/CAS9 was used to disrupt Tsc1 or Tsc2 genes in mouse inner medullary collecting duct (mIMCD3) cells.
• EVs were isolated and characterized using size-exclusion chromatography, tunable resistive pulse sensing, and dynamic light scattering.
• EVs were analyzed for protein content via immunoblotting and miRNA expression via quantitative PCR.

Main Results:

• EVs from Tsc1-mutant cells exhibited reduced production and release rates compared to Tsc2-mutant cells.
• EVs from Tsc1 and Tsc2 mutant cells differentially altered mTORC1, autophagy, and β-catenin signaling pathways.
• Downregulation of miR-212a-3p and miR-99a-5p was observed in EVs from Tsc2-mutated cells compared to Tsc1-mutant cells.

Conclusions:

• EVs from Tsc1 and Tsc2 mutant cells have distinct molecular profiles and signaling impacts.
• EV-derived miR-212-3p and miR-99a-5p may represent potential therapeutic targets or biomarkers for TSC.
• This study highlights the heterogeneity in TSC pathogenesis driven by differential EV function.