title: Prenatal exposure to chromium induces early reproductive senescence by increasing germ cell apoptosis and advancing germ cell cyst breakdown in the F1 offspring.
abstract: Hexavalent chromium (CrVI), one of the more toxic heavy metals, is widely used in more than 50 industries such as chrome plating, welding, wood processing and tanneries. As one of the world's leading producers of chromium compounds, the U.S. is facing growing challenges in protecting human health against multiple adverse effects of CrVI. CrVI is rapidly converted to CrIII intracellularly, and can induce apoptosis through different mechanisms. Our previous studies demonstrated postnatal exposure to CrVI results in a delay or arrest in follicle development and puberty. Pregnant rats were treated with 25 ppm potassium dichromate (CrVI) from gestational day (GD) 9.5 to 14.5 through drinking water, placentae were removed on GD 20, and total Cr was estimated in the placentae; ovaries were removed from the F1 offspring on postnatal day (PND)-1 and various analyses were performed. Our results show that gestational exposure to CrVI resulted in (i) increased Cr concentration in the placenta, (ii) increased germ cell apoptosis by up-regulating p53/p27-Bax-caspase-3 proteins and by increasing p53-SOD-2 co-localization; (iii) accelerated germ cell cyst (GCC) breakdown; (iv) advanced primordial follicle assembly and primary follicle transition and (v) down regulation of p-AKT, p-ERK and XIAP. As a result of the above events, CrVI induced early reproductive senescence and decrease in litter size in F1 female progeny.
authors: Department of Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, TAMU-4458, Texas A&M University, College Station, TX 77843, USA.
authors: Kirthiram K
authors: KK
authors: Sivakumar
authors: Department of Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, TAMU-4458, Texas A&M University, College Station, TX 77843, USA.
authors: Jone A
authors: JA
authors: Stanley
authors: Department of Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, TAMU-4458, Texas A&M University, College Station, TX 77843, USA.
authors: Joe A
authors: JA
authors: Arosh
authors: Department of Biology, Syracuse University, 114 Life Sciences Complex, 107 College Place, Syracuse, NY 13244, USA.
authors: Melissa E
authors: ME
authors: Pepling
authors: Department of Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, TAMU-4458, Texas A&M University, College Station, TX 77843, USA.
authors: Robert C
authors: RC
authors: Burghardt
authors: Department of Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, TAMU-4458, Texas A&M University, College Station, TX 77843, USA. Electronic address: skbanu@cvm.tamu.edu.
authors: Sakhila K
authors: SK
authors: Banu
mesh_terms: D000818:Animals; D017209:Apoptosis; D002857:Chromium / Q000633:toxicity*; D003560:Cysts / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D005854:Germ Cells / Q000187:drug effects* / Q000473:pathology*; D007150:Immunohistochemistry; D018811:Maternal Exposure / Q000009:adverse effects*; D008856:Microscopy, Fluorescence; D006080:Ovarian Follicle / Q000187:drug effects; D010053:Ovary / Q000187:drug effects; D010920:Placenta / Q000187:drug effects; D011192:Potassium Dichromate / Q000737:chemistry; D011247:Pregnancy; D011270:Pregnancy, Animal; D051381:Rats; D012098:Reproduction / Q000187:drug effects*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D016159:Tumor Suppressor Protein p53; D002857:Chromium; C074702:chromium hexavalent ion; D011192:Potassium Dichromate
keywords: Chromium; Follicle atresia; Germ cell cyst breakdown; Ovary; Primordial follicle