Endocrine disruptor vinclozolin induced epigenetic transgenerational adult-onset disease

Abstract

The fetal basis of adult disease is poorly understood on a molecular level and cannot be solely attributed to genetic mutations or a single etiology. Embryonic exposure to environmental compounds has been shown to promote various disease states or lesions in the first generation (F1). The current study used the endocrine disruptor vinclozolin (antiandrogenic compound) in a transient embryonic exposure at the time of gonadal sex determination in rats. Adult animals from the F1 generation and all subsequent generations examined (F1-F4) developed a number of disease states or tissue abnormalities including prostate disease, kidney disease, immune system abnormalities, testis abnormalities, and tumor development (e.g. breast). In addition, a number of blood abnormalities developed including hypercholesterolemia. The incidence or prevalence of these transgenerational disease states was high and consistent across all generations (F1-F4) and, based on data from a previous study, appears to be due in part to epigenetic alterations in the male germ line. The observations demonstrate that an environmental compound, endocrine disruptor, can induce transgenerational disease states or abnormalities, and this suggests a potential epigenetic etiology and molecular basis of adult onset disease.

Fig. 1

Disease states or abnormalities in vinclozolin and control generation (F1–F4) animals. A, Males from combined (F1–F4) generation animals. B, Males from individual (F1–F4) generation animals. C, Females from combined (F1–F4) generation animals. The percentage disease prevalence is presented for tumors, prostate disease, kidney disease, testis (i.e. spermatogenesis) abnormalities and immune abnormalities. The total number of animals for each generation (F1–F4) is listed in Materials and Methods. The absence of a control bar indicates zero in the control population of animals. All the comparative (A) vinclozolin generation animal disease and abnormality prevalence data provided were statistically different from controls with P < 0.05 using a Fisher’s exact test analysis as described in Materials and Methods.

Fig. 2

Histology of representative vinclozolin generation breast fibroadenoma. A representative ×400 magnification (A) and ×200 magnification (B) micrograph is presented from a minimum of five different animals with breast adenoma analyzed. A closed arrow indicates a neoplastic glandular epithelial cell population.

Fig. 3

Histology of representative control (A and C) and vincozolin (B and D) F2 or F3 generation tissues are presented, ventral prostate (A and B), and kidney (C and D). A representative ×200 magnification micrograph is presented from a minimum of five animals analyzed. Insets in A and B are ×1000 magnification. A closed arrow indicates a normal epithelial cell and a red arrowhead an abnormal epithelial cell, and a closed arrowhead an abnormal tubule and a half-arrow an increased width of Bowman’s capsule.

Fig. 4

Blood analysis for BUN (A) and creatinine (B) from control and vinclozolin (F1–F4) generation animals. Scatter plots are presented with a mean line indicated. Samples in the dashed boxes correlate with animals with diagnosed morphological kidney abnormalities and corresponding renal blood marker increases.

Fig. 5

Histology of representative control (A, C) and vincozolin (B and D) F2 or F3 generation tissues are presented for normal testis (A), abnormal testis (B), and liver (C and D). A representative ×200 (A and B) or ×400 (C and D) magnification micrograph is presented from a minimum of five animals analyzed. A closed arrow indicates a normal epithelial cell and tubule, where as a redarrow head an abnormal epithelial cell and tubule. No histologic abnormalities were observed in the liver.

Fig. 6

Blood analysis for combined F1–F4 control and vinclozolin generation animals. A, Cholesterol concentrations and liver serum markers of (B) alanine transferase and (C) alkaline phosphatase are presented (units/liter). Scatter plots are indicated for 3-month-old and 6- to 12-month-old animals with the bar representing the mean. *, Mean values are statistically different (P < 0.05) from control values for cholesterol. No statistical differences were detected in B or C means.

Fig. 7

Comparison of outcross disease states or abnormalities using F1–F4 control and vinclozolin generation-treated cross compared with VOC (F2 vinclozolin generation male and wild-type female) and a RVOC (F2 vinclozolin generation female and wild-type male). The percentage disease prevalence is presented for tumors, prostate disease, kidney disease, testis abnormalities, and immune abnormalities. The absence of a bar indicates zero in the population of animals. The total number of animals for VOC and RVOC were n = 19 and 6, respectively. The VOC was statistically different from control with P < 0.05.