Effects and mechanisms of pyrethroids on male reproductive system.

Synthetic pyrethroids are used as insecticides in agriculture and a variety of household applications worldwide. Pyrethroids are widely distributed in all environmental compartments and the general populations are exposed to pyrethroids through various routes. Pyrethroids have been identified as endocrine-disrupting chemicals (EDCs) which are responsible for the male reproductive impairments. The data confirm pyrethroids cause male reproductive damages. The insecticides exert the toxic effects on male reproductive system through various complex mechanisms including antagonizing androgen receptor (AR), inhibiting steroid synthesis, affecting the hypothalamic-pituitary-gonadal (HPG) axis, acting as estrogen receptor (ER) modulators and inducing oxidative stress. The mechanisms of male reproductive toxicity of pyrethroids involve multiple targets and pathways. The review will provide further insight into pyrethroid-induced male reproductive toxicity and mechanisms, which is crucial to preserve male reproductive health.

Inhibitory Effects of Cypermethrin on Interactions of the Androgen Receptor with Coactivators ARA70 and ARA55.

OBJECTIVE: The purpose of this study was to investigate the anti-androgenic mechanism of cypermethrin involving coactivators. METHODS: Mammalian two-hybrid assays were performed to study the effects of cypermethrin on interactions of the androgen receptor (AR) with the coactivators androgen receptor-associated protein 70 (ARA70) and androgen receptor-associated protein 55 (ARA55). RESULTS: The results showed that AR-ARA70 and AR-ARA55 interactions were remarkably enhanced by dihydrotestosterone (DHT, P ≤ 0.05). Cypermethrin inhibited DHT-induced AR-ARA70 and AR-ARA55 interactions significantly ( P ≤ 0.05). CONCLUSION: The study indicates that cypermethrin exhibits inhibitory effects on AR transcription associated with repression of AR-ARA70 and AR-ARA55 interactions in a ligand-dependent manner. The data show novel anti-androgenic mechanisms of cypermethrin that contribute to male reproductive toxicology.

Investigation of candidate genes of non-syndromic cleft lip with or without cleft palate, using both case-control and family-based association studies.

OBJECTIVE: Non-syndromic cleft of the lip and/or palate (NSCL/P) is one of the most common polygenic diseases. In this study, both case-control and family-based association study were used to confirm whether the Single Nucleotide Polymorphisms (SNPs) were associated with NSCL/P. METHODS: A total of 37 nuclear families and 189 controls were recruited, whose blood DNA was extracted and subjected to genotyping of SNPs of 27 candidate genes by polymerase chain reaction-improved multiple ligase detection reaction technology (PCR-iMLDR). Case-control statistical analysis was performed using the SPSS 19.0. Haplotype Relative Risk (HRR), transmission disequilibrium test (TDT), and Family-Based Association Test (FBAT) were used to test for over-transmission of the target alleles in case-parent trios. The gene-gene interactions on NSCL/P were analyzed by Unphased-3.1.4. RESULTS: In case-control statistical analysis, only C14orf49 chr14_95932477 had statistically significant on genotype model (P = .03) and allele model (P = .03). Seven SNPs had statistically significant on TDT. None of 26 alleles has association with NSCL/P on FBAT. Some SNPs had haplotype-haplotype interactions and genotype-genotype interactions. CONCLUSION: C14orf49 chr14_95932477 was significantly different between cases and controls on genotype model and allele model by case-control design. Seven SNPs were significantly different on HRR. Four SNPs were significantly different on TDT.

The anti-androgenic effects of cypermethrin mediated by non-classical testosterone pathway activation of mitogen-activated protein kinase cascade in mouse Sertoli cells.

Previous studies have demonstrated that the anti-androgenic effects of cypermethrin (CYP) are associated with testosterone (T) - related signaling pathway. This study was to investigate the effects of CYP on mouse Sertoli cells (TM4) and clarify whether the mechanisms were mediated by non-classical T signaling pathway activating mitogen-activated protein kinase (MAPK) cascade. The Cell Counting Kit 8 (CCK8) and Real-Time Cell Analysis iCELLigence (RTCA-iCELLigence) system were performed to detect the effects of 10 µM, 20 µM, 40 µM and 80 µM CYP on the viability and proliferation of TM4. The mammalian two hybrid assay, quantitative Real-Time PCR (qRT-PCR) and western blot were conducted to analyze the key genes and proteins involved in T-mediated MAPK signaling pathway. CYP was found to inhibit the viability and proliferation of TM4. Additionally, CYP disturbed the functions of Sertoli cells by inhibiting inhibin B (INH B) expression and facilitating androgen binding protein (ABP) and transferrin (TF) expression. Moreover, CYP suppressed the interaction of AR and Src kinase and inhibited androgen-mediated phosphorylation of Src, epidermal growth factor receptor (EGFR), extracellular-regulated kinase1/2 (ERK1/2) and transcription factor cAMP response element binding protein (CREB). Furthermore, the androgen-induced mRNA and protein expression of CREB-regulated gene early growth response factor (Egr1) decreased after treated with CYP. It is indicated that CYP inhibits the viability and proliferation of Sertoli cells and non-classical T signaling pathway activation of MAPK cascade is involved in anti-androgenic effect of CYP. This study provides a novel insight into the CYP-induced reproductive toxicity.

Targeting YOD1 by RNA Interference Inhibits Proliferation and Migration of Human Oral Keratinocytes through Transforming Growth Factor-ß3 Signaling Pathway.

OBJECTIVE: We have identified a gene YOD1 encoding deubiquitinating enzyme (DUB) responsible for nonsyndromic cleft lip with or without cleft palate (NSCL/P). We aimed to determine the effects of YOD1 RNA interference (RNAi) on cell proliferation and migration, playing an important role in lip and palate formation, and to clarify whether the mechanisms involved TGF-ß3 signaling associated with NSCL/P. METHODS: RNAi was applied to construct vectors expressing YOD1 small interference RNAs (siRNAs). The vectors were transfected into the human oral keratinocytes (HOK) cells. The cell proliferation and migration were evaluated by the cell counting kit-8 (CCK-8) assay and wound healing assay, respectively. The mRNA levels were detected by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). The protein levels were investigated by western blotting. RESULTS: The proliferation of YOD1 siRNA-transfected HOK cells was remarkably inhibited. The migration rate was significantly decreased in the YOD1 siRNA-transfected HOK cells. The TGF-ß3 mRNA and protein levels were decreased significantly by siRNA-mediated knockdown of YOD1. YOD1 RNAi reduced the phosphor-Smad2/3 levels significantly. CONCLUSIONS: YOD1 RNAi may inhibit cell proliferation and migration associated with the pathogenesis of NSCL/P through TGF-ß3 signaling. The study indicates a novel role of YOD1 in regulating TGF-ß3 signaling to affect cell proliferation and migration resulting in NSCL/P.

Identification of key genes in cleft lip with or without cleft palate regulated by miR-199a-5p.

BACKGROUND: Cleft lip with or without cleft palate (CL/P) is one of the most common congenital defects, which etiology involves both genetic and environmental factors. Previous studies have shown that miR-199a-5p may mediate the occurrence of CL/P. However, the key target genes regulated by miR-199a-5p are not clear. In this study, we employed a systematic bioinformatics analysis of target genes regulated by miR-199a-5p which may be involved in CL/P. METHODS: The miRBase, Human miRNA tissue atlas, miRecords, miRpathDB, miRWalk, miRTarBase, DIANA-TarBase (v7.0), Literature search, DAVID software, Cytoscape plugin ClueGO + Cluepedia app, MalaCards, TargetScanhuman7.1, Venny 2.1, STRING and GEO databases were comprehensive employed to identify the key genes regulated by miR-199a-5p associated with CL/P. RESULTS: Total 429 experimentally validated target genes were obtained from five miRNAs related databases. Expressions of miR-199a-5p and its experimentally validated target genes were elevated in bone, brain and skin. KEGG pathway analysis revealed that the target genes were enriched in focal adhesion, microRNAs in cancer and hippo signaling pathway. Biological process categorization revealed that significant portions of the target genes were grouped as transcription, DNA-templated. Total eight intersection genes were identified by using MalaCards and TargetScanhuman7.1. The target gene transforming growth factor alpha (TGFA) of miR-199a-5p involved in CL/P is screened and verified. CONCLUSION: MiR-199a-5p may mediate CL/P by regulating key target gene TGFA. The study may contribute to a better understanding of the etiology of CL/P.