title: A transient disruption of fibroblastic transcriptional regulatory network facilitates trans-differentiation.
abstract: Transcriptional Regulatory Networks (TRNs) coordinate multiple transcription factors (TFs) in concert to maintain tissue homeostasis and cellular function. The re-establishment of target cell TRNs has been previously implicated in direct trans-differentiation studies where the newly introduced TFs switch on a set of key regulatory factors to induce de novo expression and function. However, the extent to which TRNs in starting cell types, such as dermal fibroblasts, protect cells from undergoing cellular reprogramming remains largely unexplored. In order to identify TFs specific to maintaining the fibroblast state, we performed systematic knockdown of 18 fibroblast-enriched TFs and analyzed differential mRNA expression against the same 18 genes, building a Matrix-RNAi. The resulting expression matrix revealed seven highly interconnected TFs. Interestingly, suppressing four out of seven TFs generated lipid droplets and induced PPARG and CEBPA expression in the presence of adipocyte-inducing medium only, while negative control knockdown cells maintained fibroblastic character in the same induction regime. Global gene expression analyses further revealed that the knockdown-induced adipocytes expressed genes associated with lipid metabolism and significantly suppressed fibroblast genes. Overall, this study reveals the critical role of the TRN in protecting cells against aberrant reprogramming, and demonstrates the vulnerability of donor cell's TRNs, offering a novel strategy to induce transgene-free trans-differentiations.
authors.affiliation: RIKEN Omics Science Center, 1-7-22 Suehiro-cho, Tsurumi-Ku, Yokohama 230-0045, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tomaru
authors.affiliation: RIKEN Center for Life Science Technologies, Division of Genomic Technologies, 1-7-22 Suehiro-cho, Tsurumi-Ku, Yokohama 230-0045, Japan Division of Genomic Information Resources, International Graduate School of Arts and Sciences, Yokohama City University, Yokohama 230-0045, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Hasegawa
authors.affiliation: RIKEN Omics Science Center, 1-7-22 Suehiro-cho, Tsurumi-Ku, Yokohama 230-0045, Japan RIKEN Center for Life Science Technologies, Division of Genomic Technologies, 1-7-22 Suehiro-cho, Tsurumi-Ku, Yokohama 230-0045, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Discovery Pharmacology Department 1, Research Division, Chugai Pharmaceutical Co., Ltd, 1-135 Komakado, Gotemba, Shizuoka 412-8513, Japan.
authors.forename: Taiji
authors.initials: T
authors.lastname: Sato
authors.affiliation: RIKEN Omics Science Center, 1-7-22 Suehiro-cho, Tsurumi-Ku, Yokohama 230-0045, Japan.
authors.forename: Atsutaka
authors.initials: A
authors.lastname: Kubosaki
authors.affiliation: RIKEN Omics Science Center, 1-7-22 Suehiro-cho, Tsurumi-Ku, Yokohama 230-0045, Japan Division of Genomic Information Resources, International Graduate School of Arts and Sciences, Yokohama City University, Yokohama 230-0045, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: RIKEN Omics Science Center, 1-7-22 Suehiro-cho, Tsurumi-Ku, Yokohama 230-0045, Japan RIKEN Center for Life Science Technologies, Division of Genomic Technologies, 1-7-22 Suehiro-cho, Tsurumi-Ku, Yokohama 230-0045, Japan RIKEN Preventive Medicine and Diagnosis Innovative Program, Wako, Saitama 351-0198, Japan.
authors.forename: Hideya
authors.initials: H
authors.lastname: Kawaji
authors.affiliation: RIKEN Omics Science Center, 1-7-22 Suehiro-cho, Tsurumi-Ku, Yokohama 230-0045, Japan RIKEN Center for Life Science Technologies, Division of Genomic Technologies, 1-7-22 Suehiro-cho, Tsurumi-Ku, Yokohama 230-0045, Japan.
authors.forename: Alistair R R
authors.initials: AR
authors.lastname: Forrest
authors.affiliation: RIKEN Omics Science Center, 1-7-22 Suehiro-cho, Tsurumi-Ku, Yokohama 230-0045, Japan RIKEN Preventive Medicine and Diagnosis Innovative Program, Wako, Saitama 351-0198, Japan.
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Hayashizaki
authors.affiliation: RIKEN Omics Science Center, 1-7-22 Suehiro-cho, Tsurumi-Ku, Yokohama 230-0045, Japan RIKEN Center for Life Science Technologies, Division of Genomic Technologies, 1-7-22 Suehiro-cho, Tsurumi-Ku, Yokohama 230-0045, Japan jay.shin@riken.jp.
authors.forename: Jay W
authors.initials: JW
authors.lastname: Shin
authors.affiliation: RIKEN Omics Science Center, 1-7-22 Suehiro-cho, Tsurumi-Ku, Yokohama 230-0045, Japan RIKEN Center for Life Science Technologies, Division of Genomic Technologies, 1-7-22 Suehiro-cho, Tsurumi-Ku, Yokohama 230-0045, Japan jay.shin@riken.jp.
authors.forename: Harukazu
authors.initials: H
authors.lastname: Suzuki
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000378:metabolism; D000328:Adult; D054338:Cell Transdifferentiation / Q000235:genetics*; D002478:Cells, Cultured; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism*; D053263:Gene Regulatory Networks; D006801:Humans; D007231:Infant, Newborn; D034622:RNA Interference; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000378:metabolism*; D059467:Transcriptome
chemical_list: D014157:Transcription Factors