Cytoprotective effect exerted by geraniin in HepG2 cells is through microRNA mediated regulation of BACH-1 and HO-1 |
Hoda Aayadi1, Smriti Mittal1, Anjali Deshpande2, Makarand Gore2, Saroj Ghaskadbi1,* |
1Department of Zoology, Savitribai Phule Pune University, 2AJ Organica Pvt. Ltd, AJ Organica Pvt. Ltd. |
Abstract
Geraniin, a hydrolysable tannin, used in traditional medicine in Southeast Asia, is known to exhibit various biological activities. As an antioxidant it is known to up-regulate phase II enzyme Heme oxygenase-1 (HO-1). However its mechanism is not clearly understood. Nuclear factor erythroid-derived 2 related factor 2 (Nrf-2) is transcriptionally up-regulated by Extracellular signal-regulated kinase (ERK) 1/2 and retained in nucleus due to inactivated Glycogen synthase kinase 3 beta (GSK-3モ). Geraniin additionally down-regulates expression of microRNA 217 and 377 (miR-217 and miR-377) which target HO-1 mRNA. Expression of BTB and CNC homolog 1 (BACH-1), another regulator of HO-1, is also down-regulated by up-regulating microRNA 98 (miR-98), a negative regulator of BACH-1. Thus, geraniin up-regulates HO-1 expression both through activating its positive regulator Nrf-2 and by down-regulating its negative regulator BACH-1. Up-regulation of HO-1 also confers protection to HepG2 cells from tertiary butyl hydroperoxide (TBH) induced cytotoxicity.
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Abstract, Accepted Manuscript(in press) [Submitted on April 10, 2017, Accepted on June 7, 2017] |
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