Nephrotic syndrome (NS) is the second leading cause of chronic kidney disease (CKD) presenting under the age of 30. NS presents in children with edema and severe proteinuria, caused by the effacement of podocyte foot processes within the glomerular filtration barrier. Patients with steroid-resistant NS (SRNS) frequently develop end-stage renal disease (ESRD). Additionally, renal biopsies from these patients often reveal focal segmental glomerulosclerosis (FSGS).
Pathogenic mutations in known monogenic disease genes have been found in 11-45% children with FSGS/SRNS. Notably, most Mendelian etiologies exhibit recessive inheritance, while dominant vertical inheritance with incomplete penetrance is observed in the remainder. The role of de novo variants (DNVs) in NS necessitates further investigation.
Tripartite motif containing 8, TRIM8, is an E3 ubiquitin ligase. De novo TRIM8 variants were previously implicated in a syndromic disease consisting of neurodevelopmental delay, epilepsy, cerebral atrophy, and nephrotic syndrome.
In this study, we recapitulate the patient-specific mutations in inducible overexpression cell lines and in CRISPR/Cas9-generated mouse models. N-terminal MYC or GFP-tagged TRIM8 inducible cell lines were generated and characterized using the pInducer21 system. Western blot and immunofluorescence data show that MYC- and GFP-TRIM8 were induced by doxycycline in immortalized podocyte cell lines. Candidate interactors for TRIM8 from the literature and stratified using kidney single cell mRNA sequencing expression were cloned into mammalian expression vectors. Finally, a Trim8 knockout allele (c. 56_162del; p.H20Qfs*124 and c.367_463+304delins46) was generated and bred to yield an allelic series of wildtype, heterozygous and homozygous animals. These mice exhibited normal survival and did not demonstrate proteinuria through three to four months of life. Overall, further studies are ongoing with regards to the continued monitoring of proteinuria and kidney dysfunction, as well as the potential interactor cloning and cell line characterization. / 2025-02-06T00:00:00Z
| Identifer | oai:union.ndltd.org:bu.edu/oai:open.bu.edu:2144/45593 |
| Date | 07 February 2023 |
| Creators | Liang, Lorrin |
| Contributors | Symes, Karen, Majmundar, Amar |
| Source Sets | Boston University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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