title: Di 2-ethyl hexyl phthalate affects differentiation and matrix mineralization of rat calvarial osteoblasts--in vitro.
abstract: Di-2-ethyl hexyl phthalate (DEHP), an industrial plasticizer and a ubiquitous environmental contaminant, is an established endocrine disruptor (ED). Increasing evidences indicate that some EDs interfere with osteoblast differentiation and function. In the present study, we investigated the effects of DEHP on the expression of cell cycle proteins, differentiation markers, Runx2 and its co-activator TAZ in osteoblasts derived from neonatal rat calvaria. A significant decrease in protein levels of cyclin D1 and CDK-2 was found at high dosage of DEHP (100 μM) after 24h treatment. DEHP treatment caused a significant decrease in ALP mRNA. While DEHP treatment significantly decreased the TAZ at mRNA and protein levels, it decreased only the Runx2protein levels. Histochemical localization of ALP, collagen and mineralized nodules studied from cells treated with DEHP (10 and 100 μM) for 21 days revealed a drastic decrease in collagen, ALP and mineralization. In conclusion, DEHP affected differentiation of neonatal rat calvarial osteoblasts and mineralization of matrix secreted by these cells.
authors.affiliation: Department of Endocrinology, Dr. ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Sekkizhar Campus, Taramani, Chennai 600113, India.
authors.forename: Firdous Ahmad
authors.initials: FA
authors.lastname: Bhat
authors.forename: G
authors.initials: G
authors.lastname: Ramajayam
authors.forename: S
authors.initials: S
authors.lastname: Parameswari
authors.forename: R C
authors.initials: RC
authors.lastname: Vignesh
authors.forename: S
authors.initials: S
authors.lastname: Karthikeyan
authors.forename: K
authors.initials: K
authors.lastname: Senthilkumar
authors.forename: G D
authors.initials: GD
authors.lastname: Karthikeyan
authors.forename: K
authors.initials: K
authors.lastname: Balasubramanian
authors.forename: J
authors.initials: J
authors.lastname: Arunakaran
authors.forename: N
authors.initials: N
authors.lastname: Srinivasan
mesh_terms: D000217:Acyltransferases; D000469:Alkaline Phosphatase / Q000235:genetics / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D002113:Calcification, Physiologic / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003094:Collagen / Q000378:metabolism; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics / Q000378:metabolism; D019938:Cyclin D1 / Q000378:metabolism; D051357:Cyclin-Dependent Kinase 2 / Q000378:metabolism; D004051:Diethylhexyl Phthalate / Q000633:toxicity*; D004785:Environmental Pollutants / Q000633:toxicity*; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010968:Plasticizers / Q000633:toxicity*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D012886:Skull / Q000166:cytology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: C530106:Ccnd1 protein, rat; D050659:Core Binding Factor Alpha 1 Subunit; D004785:Environmental Pollutants; D047908:Intracellular Signaling Peptides and Proteins; D010968:Plasticizers; D012333:RNA, Messenger; C493717:Runx2 protein, rat; D014157:Transcription Factors; D019938:Cyclin D1; D003094:Collagen; D004051:Diethylhexyl Phthalate; D000217:Acyltransferases; C544439:Tafazzin protein, rat; C495892:Cdk2 protein, rat; D051357:Cyclin-Dependent Kinase 2; D000469:Alkaline Phosphatase