ABSTRACT
A father's lifetime experience is a major risk factor for a range of diseases in an individual, and the consequences of the exposure can also be transmitted to his offspring. Our previous work has demonstrated that damage to testicular structures and decline in sperm quality in male mice can be caused by microcystin-leucine arginine (MC-LR), but the overall effects of the scope and extent of paternal exposure on health and disease in the offspring remain underexplored. Here, we report that MC-LR-paternal-exposed offspring mice showed reduced litter size and body weight accompanied by increased abnormalities in the lung. Analyses of the small noncoding RNAs (sncRNAs) in the sperm from MC-LR-exposed males demonstrated the downregulation of a wide range of piRNAs enriched for those target genes involved in the regulation of the embryo implantation pathways. Gene and protein expression analyses, as well as biochemical and functional studies, revealed suppressed expression of Hsp90α in testicular tissues from MC-LR-exposed males. Decreased Hsp90α in testicular tissues impaired the development of the offspring. In this study, we revealed that MC-LR alters the expression of Hsp90α in testicular tissues to cause changes in the expression profiles of sperm piRNAs produced by paternal mice. These changes lead to aberrant activation of the Wnt/ß-catenin signaling pathway in pulmonary tissues of offspring mice, causing lung tissue damage and abnormal development. We hereby confirmed that MC-LR-induced alterations in epigenetic inheritance are capable of contributing to intergenerational developmental defects in paternal-exposed offspring mice.
Subject(s)
Arginine , Microcystins , Animals , Fathers , Humans , Leucine , Male , Mice , Mice, Inbred BALB CABSTRACT
BACKGROUND: Microcystin-leucine arginine (MC-LR) could disrupt prostate development and cause prostate hyperplasia. But whether and how maternal and before-weaning MC-LR exposure causes prostate hyperplasia in male offspring by changing expression profile of P-element-induced wimpy (PIWI)-interacting RNAs (piRNAs) have not yet been reported. METHODS: From the 12th day in the embryonic period to the 21st day after offspring birth, three groups of pregnant mice that were randomly assigned were exposed to 0, 10, and 50 µg/L of MC-LR through drinking water followed by the analyses of their male offspring. Abortion rate and litter size of maternal mice were recorded. The prostate histopathology was observed. Differential expressed piRNAs of prostate were screened by piRNA microarray analysis. Murine prostate cancer cell line (RM-1) was used for further mechanism study. Luciferase report assay was used to determine the relationship between piRNA-DQ722010 and polypeptide 3 (Pik3r3). RESULTS: The downregulated expression of piRNA-DQ722010 was the most significant in piRNA microarray analysis in 10 µg/L MC-LR treated group, while Pik3r3 was significantly upregulated, consistent with the results that a distinct prostatic epithelial hyperplasia was observed and phosphoinositide-3-kinase (PI3K)/protien kinase B (AKT) signaling pathway was activated. Pik3r3 was verified as the target gene of piRNA-DQ722010. In addition, we found MC-LR decreased the expression of PIWI-like RNA-mediated gene silencing 2 (Piwil2) and 4 (Piwil4) both in vivo and in vitro, and both Piwil4 and Piwil2 could regulate the expression of DQ722010. CONCLUSION: MC-LR caused downregulation of piRNA-DQ722010 and PIWI proteins, while piRNA-DQ722010 downregulation promoted activation of PI3K/AKT signaling pathway inducing prostate hyperplasia by upregulating the expression of Pik3r3. In contrast, piRNA-DQ722010 downregulation may be attributed to PIWI proteins downregulation.
Subject(s)
Bacterial Toxins/adverse effects , Epithelial Cells/metabolism , Marine Toxins/adverse effects , Maternal Exposure/adverse effects , Microcystins/adverse effects , Prostate/pathology , Prostatic Neoplasms/metabolism , RNA, Small Interfering/biosynthesis , Animals , Arginine/adverse effects , Argonaute Proteins/genetics , Argonaute Proteins/metabolism , Bacterial Toxins/metabolism , Cell Line, Tumor , Cyanobacteria Toxins , Disease Models, Animal , Drinking Water/microbiology , Epithelial Cells/drug effects , Epithelial Cells/pathology , Female , Fresh Water/microbiology , Hyperplasia , Leucine/adverse effects , Male , Marine Toxins/metabolism , Mice , Mice, Inbred BALB C , Microarray Analysis , Microcystins/metabolism , Phosphatidylinositol 3-Kinases/biosynthesis , Phosphatidylinositol 3-Kinases/genetics , Phosphatidylinositol 3-Kinases/metabolism , Pregnancy , Prostate/drug effects , Prostate/metabolism , Prostatic Neoplasms/etiology , Prostatic Neoplasms/pathology , Protein Isoforms , Proto-Oncogene Proteins c-akt/metabolism , RNA, Small Interfering/metabolism , Signal Transduction , Water Pollution/adverse effectsABSTRACT
To investigate the possible molecular mechanism of low concentration plasticizer mono-n-butyl phthalate (MBP) -induced juvenile Sertoli cells (SCs) proliferation, we evaluated global alterations of miRNA and mRNA expression in rat SCs treated with 0.1mM MBP. Microarray analysis revealed that miR-3584-5p and miR-301b-3p were up-regulated and their common target gene Dexamethasone-induced Ras-related protein 1 (Rasd1) was down-regulated. Further work suggested that SCs proliferation induced by low concentration MBP in vitro might be mediated by Rasd1 regulating ERK1/2 signaling pathway. The present study is first to investigate the effect of low-dose MBP on SCs proliferation and may enhance our understanding on the modes of action of low concentration MBP on male reproductive system. We hope the results will contribute to explain the causes of precocious puberty and testicular tumors induced by exogenous chemicals.
Subject(s)
Endocrine Disruptors/toxicity , Gene Expression Regulation, Developmental/drug effects , MicroRNAs/agonists , Phthalic Acids/toxicity , Plasticizers/toxicity , Sertoli Cells/drug effects , ras Proteins/antagonists & inhibitors , Animals , Cell Proliferation/drug effects , Cell Survival/drug effects , Cells, Cultured , Computational Biology , Databases, Genetic , Gene Expression Profiling , Gene Regulatory Networks/drug effects , Genes, Reporter/drug effects , Male , MicroRNAs/metabolism , Osmolar Concentration , Rats, Sprague-Dawley , Sertoli Cells/cytology , Sertoli Cells/metabolism , Testis/cytology , Testis/drug effects , Testis/growth & development , Testis/metabolism , ras Proteins/genetics , ras Proteins/metabolismABSTRACT
Humans are inevitably exposed to ubiquitous phthalate esters (PAEs). In utero exposure to di-n-butyl phthalate (DBP) induces abnormal development of the testis and reproductive tract in male offspring, which correspond closely with the human condition of testicular dysgenesis syndrome (TDS)-like syndrome. However, the underlying mechanisms have not been elucidated in detail. In this study, pregnant rats were orally exposed to either corn oil (controls) or DBP at three different doses by gavage during Gestational Days 12.5-21.5. Pathological examinations were performed for toxicity evaluation. Proliferation and apoptosis related proteins (ras related dexamethasone induced 1 (Rasd1), mitogen-activated protein kinase kinases1/2 (MEK1/2), Bcl-2, and Bax) were measured for mechanisms exploration. The results showed that different doses of DBP caused male developmental and reproductive toxicity in rats, including the decrease of anogenital distance (AGD), the histological damage of testis, and apoptosis of seminiferous tubule cells. Our data suggested that DBP played chronic and continuous toxic roles on male reproductive system by disrupting expression of Rasd1 and MEK1/2 as well as Bcl-2/Bax ratio. Further research is warranted.
