Kidney Week

Abstract: TH-OR133

Human Kidney Organoids Model Tubular Injury and Maladaptive Repair with Interstitial Fibrosis In Vitro

Session Information

• Translational Research Innovations in Kidney Organoid and Bioengineered Model Systems
  October 25, 2018 | Location: 4, San Diego Convention Center
  Abstract Time: 04:54 PM - 05:06 PM

Category: Development, Stem Cells, and Regenerative Medicine

• 501 Development, Stem Cells, and Regenerative Medicine: Basic

Authors

• Gupta, Navin R., Brigham and Women's Hospital/Harvard Medical School, Boston, Massachusetts, United States

Navin R. Gupta, MD

• Garcia, Edgar, Brigham and Women's Hospital/Harvard Medical School, Boston, Massachusetts, United States

Edgar Garcia,

• Miyoshi, Tomoya, Brigham and Women's Hospital/Harvard Medical School, Boston, Massachusetts, United States

Tomoya Miyoshi,

• Galichon, Pierre, Brigham and Women's Hospital/Harvard Medical School, Boston, Massachusetts, United States

Pierre Galichon,

• Susa, Koichiro, Brigham and Women's Hospital/Harvard Medical School, Boston, Massachusetts, United States

Koichiro Susa,

• Walter, Lauren D., The Broad Institute, Cambridge, Massachusetts, United States

Lauren D. Walter,

• Epstein, Charles B., The Broad Institute, Cambridge, Massachusetts, United States

Charles B. Epstein,

• Bonventre, Joseph V., Brigham and Women's Hospital/Harvard Medical School, Boston, Massachusetts, United States

Joseph V. Bonventre,

• Morizane, Ryuji, Brigham and Women's Hospital/Harvard Medical School, Boston, Massachusetts, United States

Ryuji Morizane,

Background

Kidney fibrosis is a unifying feature of diseases that cause progressive loss of kidney function. Upon severe or repeated tubular injury, the adaptive repair response transitions to being maladaptive and pro-fibrotic. Determining the mechanisms involved in maladaptive tubular repair is vital to developing anti-fibrotic therapies. Here we propose kidney organoids as a model for tubular adaptive and maladaptive repair with interstitial fibrosis in human tissue in vitro.

Methods

Kidney organoids were generated from hPSCs by our previously established protocol. Organoid maturation was determined by downregulation of developmental genes and upregulation of adult markers using immunostaining, qPCR, flow cytometry, and histone ChIP-seq for epigenetic analysis of chromatin remodeling overtime. Organoids with mature profiles were treated with repetitive cisplatin at 5μM. Cell proliferation, dedifferentiation, partial epithelial-to-mesenchymal transition (pEMT), G2/M cell cycle arrest, pro-inflammatory cytokine expression, myofibroblast activation and interstitial fibrosis were evaluated using a combination of Masson Trichrome, immunostaining, qPCR, and flow cytometry after each treatment.

Results

Organoids exhibited mature gene expression profiles by day 49 of differentiation. LTL⁺ tubules exhibited adaptive repair responses following the initial cisplatin treatment, including proliferation (Ki67⁺), dedifferentiation (PAX2⁺ and SOX9⁺), and pEMT (VIM⁺ and SNAIL1⁺). Upon repeated cisplatin injury, LTL⁺ cells adopt a pro-fibrotic phenotype characterized by maladaptive repair processes, including further loss of an epithelial phenotype, cell cycle arrest in the G2/M phase, and upregulated pro-inflammatory cytokine expression, followed by tubular atrophy, the transdifferentiation of peritubular fibroblasts (PDGFR-β⁺NG2^-DESM^-) and pericytes (PDGFR-β⁺NG2⁺DESM⁺) into αSMA⁺ myofibroblasts, and the advent of interstitial fibrosis (FN and COL1A1).

Conclusion

Human kidney organoids model the transition from adaptive to maladaptive repair in tubular epithelial cells with repeated injury. Human kidney organoids enable the study of tubular repair, along the continuum from acute injury to fibrosis, and the screening of anti-fibrotic therapeutics in human kidney tissue.

Funding

• NIDDK Support