Increasing contamination of the environment by toxic compounds such as endocrine disrupting chemicals (EDCs) is one of the major causes of reproductive defects in both sexes. Estrogen/androgen pathways are of utmost importance in gonadal development, determination of secondary sex characteristics and gametogenesis. Most of the EDCs mediate their action through respective receptors and/or downstream signaling. The purpose of this review is to highlight the mechanism by which EDCs can trigger antagonistic or agonistic response, acting through estrogen/androgen receptors causing reproductive defects that lead to infertility. In vitro, in vivo and in silico studies focusing on the impact of EDCs on estrogen/androgen pathways and related proteins published in the last decade were considered for the review. PUBMED and PUBCHEM were used for literature search. EDCs can bind to estrogen receptors (ERα and ERβ) and androgen receptors or activate alternative receptors such as G protein-coupled receptors (GPCR), GPR30, estrogen-related receptor (ERRγ) to activate estrogen signaling via downstream kinases. Bisphenol A, dichlorodiphenyltrichloroethane, dichlorodiphenyldichloroethylene, polychlorinated biphenyls and phthalates are major toxicants that interfere with the normal estrogen/androgen pathways leading to infertility in both sexes through many ways, including DNA damage in spermatozoids, altered methylation pattern, histone modifications and miRNA expression.
(1) Background: Organophosphorus pesticides (OPPs) are major chemicals used in agriculture for eradication of insecticides/pesticides. Unfortunately, the longtime exposure of human beings to OPPs could lead to metabolic disorder such as high blood pressure, hyperglycemia, overweight or dyslipidemia. The aim of this research is to evaluate the possible metabolic dysregulations as a consequence of chronic OPPs exposure to individuals in Cameroon and Pakistan. (2) Methods: Blood samples were collected from 300 participants in each country, into ethylenediaminetetraacetic acid (EDTA) tubes. The samples were extracted with solid phase extraction (methanol/water) for analysis of OPPs with gas chromatography mass spectrometry. The spectrophotometry and Enzyme Linked ImmunoSorbent Assay (ELISA) were used to measure the hepatic, renal, pancreatic and cardiovascular functions. The atherogenic index (AI) was also determined in OPPs exposed and nonexposed cohorts. (3) Results: The results showed the presence of malathion, parathion and chlorpyrifos OPPs residues in Cameroonians, and malathion and chlorpyrifos in Pakistani samples, respectively. Elevated Body Mass Index (BMI), insulin, blood glucose, dyslipidemia and hypertension were noted in OPPs chronic exposed groups. In addition, dysregulated liver and kidney function profiles were observed in all participants regardless of gender and age groups. (4) Conclusions: The study concludes that both the study cohorts showed several metabolic dysregulations attributable to chronic exposure to a mixture of OPPs which may provide precursors for establishment of metabolic syndrome and other chronic diseases. Further different extended population-based studies are suggested to understand the differential metabolic dysfunctions caused by structurally different OPPs mixtures exposure.
8 January 2018 in Cell Communication and Signaling
Dysregulation of hedgehog pathway is observed in numerous cancers. Relevance of hedgehog pathway genes in cancer cohort and inhibition of its downstream effector (GLI1) towards metastasis in cell lines are explored in the study. One hundred fifty fresh tumours of breast cancer patients were collected for the study. Based on differential expression, panel of 6 key regulators of the pathway (SHH, DHH, IHH, PTCH1, SMO and GLI1) in microarray datasets were identified. Expressional profiles of aforementioned genes were later correlated with clinico-pathological parameters in Pakistani breast cancer cohort at transcript and protein levels. In addition, GLI1 over expressing breast cancer cell lines (MDA-MB-231 and MCF-7) were treated with GANT61 to explore its probable effects on metastasis. SHH, DHH, PTCH1 and GLI1 were significantly over-expressed in tumours as compared with respective normal mammary tissues. A significant correlation of SHH, DHH and GLI1 expression with advanced tumour size, stages, grades, nodal involvement and distant metastasis was observed (p < 0.05). Over-expression of SHH, DHH and GLI1 was significantly related with patients having early onset and pre-menopausal status. Of note, hedgehog pathway was frequently up regulated in luminal B and triple negative breast cancer affected women. In addition, positive correlations were observed among aforementioned members of pathway and Ki67 (r-value: 0.63–0.78) emphasizing their role towards disease progression. Exposure of GANT61 (inhibitor for GLI1) significantly restricted cell proliferation, reduced cell motility and invasion. Role of activated hedgehog pathway in breast cancer metastasis provides a novel target for cancer therapy against aggressive cancer subtypes.
Adenosine (A) to inosine (I) RNA editing is a hydrolytic deamination reaction catalyzed by the adenosine deaminase (ADAR) enzyme acting on double-stranded RNA. This posttranscriptional process diversifies a plethora of transcripts, including coding and noncoding RNAs. Interestingly, few studies have been carried out to determine the role of RNA editing in vascular disease. The aim of this study was to determine the potential role of ADARs in congenital heart disease. Strong downregulation of ADAR2 and increase in ADAR1 expression was observed in blood samples from congenital heart disease (CHD) patients. The decrease in expression of ADAR2 was in line with its downregulation in ventricular tissues of dilated cardiomyopathy patients. To further decipher the plausible regulatory pathway of ADAR2 with respect to heart physiology, miRNA profiling of ADAR2 was performed on tissues from ADAR2-/- mouse hearts. Downregulation of miRNAs (miR-29b, miR-405, and miR-19) associated with cardiomyopathy and cardiac fibrosis was observed. Moreover, the upregulation of miR-29b targets COL1A2 and IGF1, indicated that ADAR2 might be involved in cardiac myopathy. The ADAR2 target vascular development associated protein-coding gene filamin B (FLNB) was selected. The editing levels of FLNB were dramatically reduced in ADAR2-/- mice; however, no observable changes in FLNB expression were noted in ADAR2-/- mice compared to wild-type mice. This study proposes that sufficient ADAR2 enzyme activity might play a vital role in preventing cardiovascular defects.