Abstract: FR-PO916
Disruption of APOL1-mIR193a Axis (AMA) Facilitates the Development of Collapsing Phenotype in HIV-Associated Nephropathy
Session Information
- Glomerular Diseases: Podocyte Biology - II
November 08, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1204 Podocyte Biology
Authors
- Kumar, Vinod, Zucker School of Medicine at Hofstra-Northwell, Great Neck, New York, United States
- Vashistha, Himanshu, Ochsner Health System, New Orleans, Louisiana, United States
- Ayasolla, Kamesh R., Feinstein Institute for Medical Research, Manhasset, New York, United States
- Lan, Xiqian, Feinstein Institute for Medical Research, Manhasset, New York, United States
- Chinnapaka, Sushma, Northwell health , Hicksville, New York, United States
- Qayyum, Maleeha, Northwell health , Hicksville, New York, United States
- Malhotra, Ashwani, Feinstein Institute Medical Research and NSLIJ, Manhasset, New York, United States
- Singhal, Pravin C., Zucker School of Medicine at Hofstra-Northwell, Great Neck, New York, United States
Background
A recent discovery of APOL1-mIR193a axis (AMA) highlighted the role of parietal epithelial cells (PECs) in podocytes' (PDs) renewal both under normal physiological and pathological states. APOL1 and miR193a inversely regulate the expression of each other. PECs do not express APOL1. However, APOL1's induction stimulates PECs transition to podocyte molecular phenotype. We hypothesize that disruption of AMA in HIV-induced proliferating PECs expressing either APOL1G1/G2 or lacking APOL1G0 compromises PECs transition result in their accumulation in the Bowman's space (collapsing phenotype). We have validated this hypothesis in HIV transgenic mice experssing APOL1G0/G1/G2.
Methods
To aim transition (differentiation) to PDs, immortalized human PECs were incubated in special media for 14 days. PECs- transduced with either vector or HIV (NL4-3) were assayed for APOL1 expression. Differentiated PECs were transduced with vector, APOL1G0, APOL1G1, or APOL1G2 lentivirus. After 48 hours, cellular lysates were probed for PEC (PAX2 and Claudin 1) and PD (CD2AP, WT1, and podocalyxin) markers. Cellular lysates of above-mentioned transduced cells were assayed for miR193a expression and PEC, and PD markers. PECs' accumulation in Bowman's space was scored in renal cortical sections of 4-week and 8-week old HIV transgenic mice (Tg26) expressing APOL1G0, APOL1G1, and APOL1G2. Three-week old TG26 mice expressing APOL1G0 were administered Adriamycin (10 mg/Kg, IV) to induce APOL1G0 deficit.
Results
HIV induced APOL1 and PD markers, however downregulated miR193a expression in PECs. Differentiated- PECs and PDs expressing APOL1G1 and APOL1G2 displayed an attenuated expression of PD markers (protein as well as mRNA) but enhanced levels of miR193a expression. Renal cortical sections of Tg26 mice expressing APOL1G1 and G2 showed higher miR193a levels and abundance of PECs in Bowman's space. Tg26 mice expressing APOL1G0 displayed attenuated miR193a levels as well as minimal PECs accumulation in Bowman's space; in contrast, Adriamycin-treated Tg26 mice expressing APOL1G0 showed attenuated APOL1, increased miR193a expression, and abundance of PECs in Bowman's space.
Conclusion
Loss of APOL1's potential modulates miR193a expression and induces the collapsing phenotype in HIVAN.
Funding
- NIDDK Support