Abstract: FR-PO615
LSD1 Nuclear Condensation Promotes Cyst Growth in Polycystic Kidney Disease
Session Information
- Cystic Kidney Diseases: Mechanisms and Models
October 25, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Genetic Diseases of the Kidneys
- 1201 Genetic Diseases of the Kidneys: Cystic
Authors
- Li, Xiaoyan, Mayo Clinic Department of Internal Medicine, Rochester, Minnesota, United States
- Zhou, Xia, Mayo Clinic Department of Internal Medicine, Rochester, Minnesota, United States
- Cheng, Shasha, Mayo Clinic Department of Internal Medicine, Rochester, Minnesota, United States
- Li, Xiaogang, Mayo Clinic Department of Internal Medicine, Rochester, Minnesota, United States
Background
Epigenetic regulation has been a focus of scientific investigation in ADPKD. We have investigated the role of lysine demethylase LSD1 in ADPKD and show that LSD1 is upregulated in Pkd1 mutant cells and tissues, and inhibition of LSD1 with its inhibitor delays cyst growth in Pkd1 mutant mice. LSD1 contains two intrinsic disordered regions (IDRs), which are frequently found in phase-separated components, suggesting that LSD1 may form liquid-liquid phase separation (LLPS) to promote target gene transcription in Pkd1 mutant cells and kidneys.
Methods
We confirm the formation of LSD1-LLPS by 1) immunofluorescence (IF) staining in Pkd1 mutant cells and kidneys, and 2) by generating LSD1 truncated constructs with one or two IDRs. We identify 1) co-factors of LSD1 in LLPS by immunoprecipitation and mass spectrometry (MS) analysis, and 2) LSD1 target genes by ChIP-seq and RNA-Seq analysis.
Results
We found that upregulated LSD1 formed LLPS droplets in Pkd1 mutant kidneys, which was rare in Pkd1 wild type kidneys. GFP-tagged LSD1 with IDR1 or both IDR1 and IDR2 formed LLPS in HEK293T cells, similar as did by full length LSD1. The DNA binding domain (DBD) was necessary for its formation, supporting by that the LSD1-IDR1-DBD (IDR1 and SWIRM) but not LSD1-IDR1 alone formed nuclear puncta in cells. LSD1 target genes identified in ChIP-seq analysis are associated with immune response, DNA, lipid and amino acid metabolic signaling pathways. We identified that CREB might be a potential co-factor of LSD1 in LLPS and CREB also bound to the promoter of LSD1 to regulate its transcription. Treatment with PKA activator FSK increased the nuclear level of LSD1 and its formation of LLPS, whereas treatment with PKA inhibitor H89 decreased the expression of LSD1 and the formation of LLPS in cells. In addition, treatment with FSK and 1,6-hexanediol (1,6-HD, a molecule known to disrupt phase separation), increased the nuclear levels of LSD1, but suppressed the formation of LSD1-CREB contained LLPS, decreased LSD1 mediated demethylation of H3K4 and H3K9, suggesting that LSD1 might promote cyst progression through LSD1-CREB LLPS mediated regulation of gene transcription.
Conclusion
In this study, we identify that LSD1 forms LLPS and CREB is co-factor in this process and confirm that the formation of LSD1-CREB mediated phase separation regulates LSD1 target gene transcription to promote cyst growth in ADPKD.
Funding
- NIDDK Support