RNA sequencing analysis reveals the GnRH induced citrullinome
presentationposted on 14.06.2017, 00:00 by Michelle A. Londe
Peptidylarginine deiminases (PADs) are a family of Ca2+ dependent enzymes that post-translationally convert positively charged arginine into neutral citrulline on histone tales to decondense chromatin and change gene expression. Our past work has established that gonadotropin releasing hormone (GnRH) stimulates PAD catalyzed citrullination of histones in gonadotropes, yet the physiological consequence of this on reproductive function are unknown. To address this, we sought to identity of the full cohort of genes regulated by citrullintation in gonadotrope cells. First, the gonadotrope derived LβT2 cell line was were pre-treated with either vehicle or the PAD inhibitor biphenyl-benzimidazole-Cl-amidine (BB-ClA) followed by treatment with vehicle or GnRH for 180 minutes. Utilizing this paradigm, we significantly blunted GnRH induced histone citrullination, validating the efficacy of our PAD inhibitor. Following the same approach, RNA was then purified and subjected to NextGen RNA sequencing. Two different methods to analyze the data were used: exploring ratio of the means and means of the ratio. From the original data sets, meaningful subsets of key gene networks were identified that are critical in maintaining gonadotrope function. Collectively, our RNA-seq data demonstrates that GnRH citrullination of histones regulates the expression of luteinizing hormone (LH) β, endoplasmic reticulum (ER) processing and golgi vesicle trafficking gene networks.