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Updated: Jul 28, 2026
Phenotypic Characterization of Macrophages from Rat Kidney by Flow Cytometry
Published on: October 18, 2016
Interferon Regulatory Factor-5 in Resident Macrophage Promotes Polycystic Kidney Disease
Kurt A Zimmerman1, Jifeng Huang2, Lan He2
1Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama.
Background:
Autosomal dominant polycystic kidney disease is caused by genetic mutations in PKD1 or PKD2. Macrophages and their associated inflammatory cytokines promote cyst progression; however, transcription factors within macrophages that control cytokine production and cystic disease are unknown.
Methods:
In these studies, we used conditional Pkd1 mice to test the hypothesis that macrophage-localized interferon regulatory factor-5 (IRF5), a transcription factor associated with production of cyst-promoting cytokines (TNFα, IL-6), is required for accelerated cyst progression in a unilateral nephrectomy (1K) model. Analyses of quantitative real-time PCR (qRT-PCR) and flow-cytometry data 3 weeks post nephrectomy, a time point before the onset of severe cystogenesis, indicate an accumulation of inflammatory infiltrating and resident macrophages in 1K Pkd1 mice compared with controls. qRT-PCR data from FACS cells at this time demonstrate that macrophages from 1K Pkd1 mice have increased expression of Irf5 compared with controls. To determine the importance of macrophage-localized Irf5 in cyst progression, we injected scrambled or IRF5 antisense oligonucleotide (ASO) in 1K Pkd1 mice and analyzed the effect on macrophage numbers, cytokine production, and renal cystogenesis 6 weeks post nephrectomy.
Results:
Analyses of qRT-PCR and IRF5 ASO treatment significantly reduced macrophage numbers, Irf5 expression in resident-but not infiltrating-macrophages, and the severity of cystic disease. In addition, IRF5 ASO treatment in 1K Pkd1 mice reduced Il6 expression in resident macrophages, which was correlated with reduced STAT3 phosphorylation and downstream p-STAT3 target gene expression.
Conclusions:
These data suggest that Irf5 promotes inflammatory cytokine production in resident macrophages resulting in accelerated cystogenesis.
Insights
Interferon regulatory factor-5 (IRF5) in macrophages drives cyst growth in polycystic kidney disease by promoting inflammatory cytokines. Inhibiting IRF5 in resident macrophages reduces cyst progression.
Area of Science:
- Nephrology
- Immunology
- Genetics
Background:
- Autosomal dominant polycystic kidney disease (ADPKD) stems from mutations in PKD1 or PKD2.
- Macrophages and inflammatory cytokines exacerbate cyst development in ADPKD.
- Key transcription factors in macrophages regulating cytokine production and ADPKD progression remain unidentified.
Purpose of the Study:
- To investigate the role of macrophage-localized interferon regulatory factor-5 (IRF5) in ADPKD progression.
- To test if IRF5 drives cyst-promoting cytokine production and accelerates disease in a mouse model.
Main Methods:
- Utilized a conditional Pkd1 mouse model of ADPKD undergoing unilateral nephrectomy (1K).
- Assessed macrophage accumulation and Irf5 expression in kidneys post-nephrectomy using qRT-PCR and flow cytometry.
- Administered IRF5 antisense oligonucleotide (ASO) to evaluate its impact on macrophage activity and cystogenesis.
Main Results:
- 1K Pkd1 mice showed increased resident and infiltrating macrophages and elevated Irf5 expression in resident macrophages.
- IRF5 ASO treatment reduced macrophage infiltration, Irf5 expression in resident macrophages, and overall cyst severity.
- IRF5 inhibition decreased Il6 expression in resident macrophages, correlating with reduced STAT3 phosphorylation.
Conclusions:
- IRF5 in resident macrophages is a key driver of inflammatory cytokine production.
- IRF5-mediated inflammation accelerates cystogenesis in ADPKD.
- Targeting IRF5 in macrophages presents a potential therapeutic strategy for ADPKD.
