bioRxiv preprint first posted online Aug. 2, 2018; doi: http://dx.doi.org/10.1101/378919. The copyright holder for this preprint (which was not peer-reviewed) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. All rights reserved. No reuse allowed without permission.
Curcumin inhibits cystogenesis in autosomal dominant polycystic kidney disease cells via altering JAK2/STAT3 activity. Foteini Patera1 †, Alex Cudzich-Mardy1†, Zhi Huang1†, & Maria Fragiadaki1* 1. Academic Nephrology Unit, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, S10 2RX, United Kingdom. * Correspondence to: Dr Maria Fragiadaki, Academic Nephrology Unit, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Beech Hill Road, S10 2RX. Tel: +44 (0) 114 215 9527 Email: m.fragiadaki@sheffield.ac.uk † These authors contributed equally.
ABSTRACT
The Janus Kinase and Signal Transducers and Activators of Transcription (JAK-STAT) is a major pathway controlling proliferation, differentiation and immunity. Its mis-regulation contributes to the development of numerous diseases including the common genetic disorder Autosomal Dominant Polycystic Kidney Disease. Curcumin is a potent anti-inflammatory phytochemical that limits cystic disease, yet the underlying mechanisms are largely unknown. We have studied the effects of curcumin on the formation of cysts in organotypic threedimensional assays. Curcumin, potently inhibits the growth of cysts in a dose- and time-dependent manner. Mechanistically, curcumin reduces the levels of tyrosine-phosphorylated STAT3 without affecting total STAT3 protein levels. JAK2, is a major tyrosine kinase known to cause various diseases, is inactivated in the presence of curcumin. Inactivation of JAK2 is mediated by its translocation into intracellular aggresomes. The role of JAK2 in ADPKD was investigating immunohistochemically using anti-JAK2 antibodies in a murine model of ADPKD (Pkd1nl/nl). In the normal kidney, JAK2 staining is restricted to tubular epithelial cells and vascular cells with lesser staining in bowman’s capsule. By contrast, mesenchymal cells and fibroblasts showed no staining. In the diseased kidney, JAK2 is strongly localised in cyst-lining epithelial and vascular cells while exhibiting some interstitial localisation. These results suggest that curcumin is a potent inhibitor of the major kinase JAK2, thus limiting cystic growth and protecting the renal epithelium from cystic development. Interestingly, JAK2 expression, monitored at the protein level by immunohistochemistry, appears higher in cystic epithelia, indicating that JAK2 may be a key contributor to disease.
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