EPA Science Inventory

NOVEL MOLECULAR TARGETS IMPLICATED IN TESTICULAR DYSGENESIS INDUCED BY GESTATIONAL EXPOSURE TO DIETHYLHEXYL PHTHALATE (DEHP)

Citation:

Klinefelter, G., J. Laskey, W. Winnik, A. Swank, J. Suarez, AND L. Strader. NOVEL MOLECULAR TARGETS IMPLICATED IN TESTICULAR DYSGENESIS INDUCED BY GESTATIONAL EXPOSURE TO DIETHYLHEXYL PHTHALATE (DEHP). Presented at 11th Annual World Congress HUPO, September 09 - 13, 2012.

Description:

Phthalate-induced Testicular Dysgenesis Syndrome describes reproductive alterations in human males such as: hypospadias, cryptorchism, low sperm counts, and testicular cancer. This work is the first comprehensive evaluation of the rat fetal testis proteome following phthalate exposure. The study objectives were to: 1) identify up/down-regulated proteins at 10 and 100 mg/kg DEHP exposures, 2) correlate them with alterations in the steroidogenic capacity and aggregation of the GD19 Leydig cell, and 3) select proteins predictive of these alterations. This study consisted of 16 litters/ treatment group (control, 10 and 100 mg/kg DEHP). Pregnant rats were dosed from GD13-DGD19. On GD19, the right testis from each male was fixed for immunohistochemistry. The left testis was incubated in media to determine testosterone production for 3 hours. Afterwards, the testes were pooled and frozen for subsequent protein extraction and quantitative 2D gel electrophoresis. 3B-HSD-immunohistochemistry data was correlated with testosterone production. A Fluoro Image Analyzer was used to scan Krypton™-stained gels. Progenesis Same Spots Software (2.0) was used for image processing and spot-area quantification. Relevant spots were punched using an Ettan spot picker. Proteins in the punches were digested with trypsin, desalted and identified using a 4800 MALDI TOF/TOF mass spectrometer and Protein Pilot 3.0 software. Relevant proteins were subjected to Ingenuity Pathway Analysis. Testosterone production by fetal Leydig cells was reduced at 100 mg/kg DEHP. At 10 mg/kg, these cells started to cluster and germ cells were noted in the interstitium. 26 Proteins were significantly down-(or up)-regulated at both exposures. Of these, 7 proteins were correlated with one or more of the following endpoints: treatment, testosterone production, small/large Leydig cell clusters. Of these, 3 proteins were actually endpoint-predictive. A novel network of pathways involving the 7 proteins is

Purpose/Objective:

The purpose of this abstract is to present a poster at the 11th Annual World Congress HUPO, Boston 2012, September 9-13, 2012

Record Details:

Record Type: DOCUMENT (PRESENTATION/ABSTRACT)
Record Last Revised: 11/02/2012
Record Created: 11/02/2012
Record Released: 11/02/2012
OMB Category: Other
Record ID: 247339

Organization:

U.S. ENVIRONMENTAL PROTECTION AGENCY

OFFICE OF RESEARCH AND DEVELOPMENT

NATIONAL HEALTH AND ENVIRONMENTAL EFFECTS RESEARCH LAB

ASSOCIATE DIRECTOR FOR HEALTH

RESEARCH CORES UNIT