Endosulfan inhibiting the meiosis process via depressing expressions of regulatory factors and causing cell cycle arrest in spermatogenic cells

Microplastics at an environmentally relevant dose enhance mercury toxicity in a marine copepod under multigenerational exposure: Multi-omics perspective

Here, we subjected the marine copepod Tigriopus japonicus to environmentally-relevant concentrations of microplastics (MPs) and mercury (Hg) for three generations (F0-F2) to investigate their physiological and molecular responses. Hg accumulation and phenotypic traits were measured in each generation, with multi-omics analysis conducted in F2. The results showed that MPs insignificantly impacted the copepod's development and reproduction, however, which were significantly compromised by Hg exposure. Interestingly, MPs significantly increased Hg accumulation and consequently aggravated this metal toxicity in T. japonicus, demonstrating their carrier role. Multi-omics analysis indicated that Hg pollution produced numerous toxic events, e.g., induction of apoptosis, damage to cell/organ morphogenesis, and disordered energy metabolism, ultimately resulting in retarded development and decreased fecundity. Importantly, MPs enhanced Hg toxicity mainly via increased oxidative apoptosis, compromised cell/organ morphogenesis, and energy depletion. Additionally, phosphoproteomic analysis revealed extensive regulation of the above processes, and also impaired neuron activity under combined MPs and Hg exposure. These alterations adversely affected development and reproduction of T. japonicus. Overall, our findings should offer novel molecular insights into the response of T. japonicus to long-term exposure to MPs and Hg, with a particular emphasis on the carrier role of MPs on Hg toxicity.

Global phosphoproteomic analysis identified key kinases regulating male meiosis in mouse

Meiosis, a highly conserved process in organisms from fungi to mammals, is subjected to protein phosphorylation regulation. Due to the low abundance of phosphorylation, there is a lack of systemic characterization of phosphorylation regulation of meiosis in mammals. Using the phosphoproteomic approach, we profiled large-scale phosphoproteome of purified primary spermatocytes undergoing meiosis I, and identified 14,660 phosphorylation sites in 4419 phosphoproteins. Kinase-substrate phosphorylation network analysis followed by in vitro meiosis study showed that CDK9 was essential for meiosis progression to metaphase I and had enriched substrate phosphorylation sites in proteins involved in meiotic cell cycle. In addition, histones and epigenetic factors were found to be widely phosphorylated. Among those, HASPIN was found to be essential for male fertility. Haspin knockout led to misalignment of chromosomes, apoptosis of metaphase spermatocytes and a decreased number of sperm by deregulation of H3T3ph, chromosomal passenger complex (CPC) and spindle assembly checkpoint (SAC). The complicated protein phosphorylation and its important regulatory functions in meiosis indicated that in-depth studies of phosphorylation-mediated signaling could help us elucidate the mechanisms of meiosis.

Ephedra herb reduces adriamycin-induced testicular toxicity by upregulating the gonadotropin-releasing hormone signalling pathway

OBJECTIVE

We investigated the protective effects of ephedra herb (HEPH) on adriamycin-induced testicular toxicity in rats and explored the potential mechanisms underlying these effects.

METHODS

A rat model of adriamycin injury was established, and sperm motility-related indicator and oxidative stress levels in the testis were evaluated. Serum levels of sex hormones and levels of testicular cell apoptosis were detected by enzyme-linked immunosorbent assay and flow cytometry, respectively. Western blotting (WB), immunofluorescence analyses, and reverse transcription-polymerase chain reaction (RT-PCR) were performed to evaluate the gonadotropin-releasing hormone (GnRH) signalling pathway- and meiosis-related genes and proteins. In subsequent in vitro experiments, adriamycin was used to stimulate GC-1 cells, which were treated with HEPH, ephedrine, or pseudoephedrine. Cell viability was assessed using flow cytometry to detect apoptosis and reactive oxygen species, whereas the GnRH signalling pathway and levels of meiosis-related genes and proteins were evaluated by InCell WB, a high-content imaging system, and RT-PCR.

RESULTS

Per in vivo experiments, HEPH restored testicular weight and function, sperm characteristics, serum and tissue hormonal levels, and antioxidant defences and significantly activated the GnRH signalling pathway- and meiosis-related protein levels. All protective effects of HEPH against adriamycin-induced injury were antagonised by the GnRH antagonist cetrorelix. In vitro, HEPH, ephedrine, and pseudoephedrine significantly reduced adriamycin-induced GC-1 cell apoptosis and reactive oxygen species levels and increased the expression of GnRH signalling pathway- and meiosis-related proteins. The effect of pseudoephedrine was greater than that of ephedrine, and these findings may be an important basis for understanding the effects of HEPH.

Curcin C inhibit osteosarcoma cell line U2OS proliferation by ROS induced apoptosis, autophagy and cell cycle arrest through activating JNK signal pathway

Osteosarcoma is a kind of primary bone malignant tumors. Its cure rate has been stagnant in the past decade years. Curcin C belongs to type I ribosome inactivating proteins, extracted from the cotyledons of post-germinated Jatropha curcas seeds. It can inhibit the proliferation of several tumor lines including U2OS cells with extraordinary efficiency. The treated U2OS cells were arrested in both S and G2/M phase, showed typical apoptosis morphological characteristic, formed autophagosomes and increase the ratio of LC3II to LC3I. Meanwhile, the level of ROS in the treated cells was found increasing significantly, with the change of mitochondrial membrane potential and decreased antioxidant enzyme activities. The application of ROS scavenger NAC not only significantly inhibited the toxicity of Curcin C but also prevented the happen of apoptosis and autophagy to some extent. These results suggested that Curcin C may function through ROS pathway. In addition, the Curcin C treatment could activate JNK and inhibit ERK signal pathway. Sp600125, an inhibitor of JNK signaling pathway, can prevent subsequent apoptosis and autophagy events, suggesting that JNK pathway was at least one of the pathways of Curcin C action. Moreover, the relevant including antagonistic among autophagy, apoptosis and cell cycle arresting induced by Curcin C also was found. In summary, it can be speculated that Curcin C may induce S, G2/M phase arrest, apoptosis and autophagy of human osteosarcoma U2OS cells through activating JNK signal pathway and blocking ERK signal pathway by promoting ROS accumulation in cell, thus finally reflected in the effect of inhibiting tumor cell proliferation.

Reactive oxygen species-evoked genotoxic stress mediates arsenic-induced suppression of male germ cell proliferation and decline in sperm quality

This study aimed to investigate whether genotoxic stress mediates arsenic (As)-induced decline in sperm quality. Mice drank ultrapure water containing NaAsO₂ (15 mg/L) for 70 days. The mature seminiferous tubules and epididymal sperm count were reduced in As-exposed mice. Cell proliferation, determined by immunostaining with Ki67, was suppressed in As-exposed seminiferous tubules and GC-1 cells. PCNA, a proliferation marker, was reduced in As-exposed mouse testes. Cell growth index was decreased in As-exposed GC-1 cells. Flow analysis showed that As-exposed GC-1 cells were retarded at G2/M phase. CDK1 and cyclin B1 were reduced in As-exposed GC-1 cells and mouse testes. Additional experiment revealed that p-ATR, a marker of genotoxic stress, was elevated in As-exposed mouse testes and GC-1 cells. Accordingly, p-p53 and p21, two downstream molecules of ATR, were increased in As-exposed GC-1 cells. Excess reactive oxygen species (ROS), measured by immunofluorescence, and DNA-strand break, determined by Comet assay, were observed in As-exposed GC-1 cells. γH2AX, a marker of DNA-strand break, was elevated in As-exposed seminiferous tubules and GC-1 cells. NAC alleviated As-evoked DNA damage, genotoxic stress, cell proliferation inhibition and sperm count reduction. In conclusion, ROS-evoked genotoxic stress mediates As-induced germ cell proliferation inhibition and decline in sperm quality.

Effect of long-term treatment with a mixture of pyrethroids on the expression of genes that govern male germ cell production in rats

Humans are exposed to pyrethroid-based pesticides through agricultural produce. In this study, male Wistar rats were orally treated for 9 to 12 months with a mixture of pyrethroids that is equivalent to one-fifth (high dose; HD) or one-twenty fifth (low dose; LD) of the amount of pyrethroids present in the cereals and rice consumed by an average Indian. In rats treated for 9 months, the spermatogenesis-associated genes Abp, Ar, Cd9, Dax1, Dazap1, Ddx3y, Gdnf, Gfra1, Grth, Inhb, Ovol1, P1, Plzf, Pygo2, Scf, Tgfb1, Tp1, Tp2, and Vim1 were downregulated in both LD and HD groups. In rats treated for 12 months Gdnf, Hsf2, Inhb, Tgfb1, Thy1, and Ybx2 expression was downregulated in both LD and HD groups. Steroidogenesis-associated genes 17-β-Hsd, Gata4, Hmgcr, Hmgcs1, Pde4b, and Tspo gene expression were reduced in both LD- and HD-treated groups treated for 9 months. In 12-month-treated rats, Creb1 expression decreased in both LD and HD groups. The epigenetic reprogramming-associated genes, Dnmt1, Dnmt3a, Dnmt3b, Hdac10, Hp1bp3, Kat3a Kat3b, Mch2ta, Ncoa7, and Sirt1 were downregulated in both HD and LD groups of 9-months-treated rats. In rats treated for 12 months, Hdac10, Mch2ta, Ncoa7, and Sirt1 messenger RNA levels decreased in both the HD and LD groups. Thus, we demonstrate that long-term exposure to a mixture of pyrethroids caused aberrations in the transcriptome of factors involved in sperm production and development.

Endosulfan induces cardiotoxicity through apoptosis via unbalance of pro-survival and mitochondrial-mediated apoptotic pathways

Although the associations between endosulfan and adverse cardiovascular health have been reported, the toxic effects and underlying mechanism of endosulfan on the heart are not well understood. In this study, we examined the cardiotoxicity induced by endosulfan using Wistar rats and human cardiomyocytes (AC16) cells. Wistar rats were divided into control group (received corn oil alone) and three concentrations of endosulfan groups (1, 5 and 10 mg/kg·bw) by gavage. The AC16 cells were treated with three various concentrations (0, 1.25, 5, and 20 μg/mL) of endosulfan. The results showed that endosulfan induced cytotoxicity through damaging myocardial structure, decreasing the viability of cardiomyocytes, and elevating the serum levels of cardiac troponin I, heart fatty acid binding protein, aspartate aminotransferase, and reactive oxygen species (p < 0.05). Moreover, measurement of mitochondrial function showed that endosulfan could significantly decrease adenosine triphosphate levels and cytochrome c oxidase IV expression in AC16 cells (p < 0.05). In addition, endosulfan obviously inhibited Bcl-2 expression, activated the expressions of cytochrome c/Caspase-9/Caspase-3 signaling pathway, and induced the apoptosis of AC16 cells (p < 0.05). Furthermore, endosulfan significantly increased the expression of Bim, and inhibited the expressions of PI3K/Akt/FoxO3a signaling pathways in cardiomyocytes (p < 0.05). These results suggest that endosulfan may induce cardiotoxicity by inducing myocardial apoptosis resulting from activation of mitochondria-mediated apoptosis pathway and inhibition of pro-survival signaling pathways, which might be helpful in elucidating the mechanism of cardiac dysfunction induced by endosulfan.

Emerging Roles of MicroRNAs and Long Noncoding RNAs in Cadmium Toxicity

Metal cadmium (Cd) and its compounds are ubiquitous industrial and environmental pollutants and they have been believed to exert severe damage to multiple organs and tissues. MicroRNAs (miRNAs) and long noncoding RNAs (lncRNAs) are the two most common noncoding RNAs and have pivotal roles in various cellular and physiological processes. Since the importance of miRNAs and lncRNAs in Cd toxicity has been widely recognized, we focus our interests on the current researches of miRNAs and lncRNAs as well as their regulation roles in Cd toxicity. In this paper, the keywords "cadmium" in combination with "miRNA" or "LncRNA" or "noncoding RNA" was used to retrieve relevant articles in PubMed, EMbase, CNKI, Wan Fang, and CBM databases. The literatures which contained the above keywords and carried out in animals (in vivo and in vitro) have been collected, collated, analyzed, and summarized. Our summary results showed that hundreds of miRNAs and lncRNAs are involved in the Cd toxicity, which have been demonstrated as multiple organ injury, reproductive toxicity, malignant transformation, and abnormal repair of DNA damage. In this paper, we also discussed the blank in present research field of Cd toxicity as well as suggested some ideas for future study in Cd toxicity.

Silica nanoparticles exacerbates reproductive toxicity development in high-fat diet-treated Wistar rats

To demonstrate the combined adverse effect and the mechanism of silica nanoparticles (SiNPs) with 57.66 ± 7.30 nm average diameter and high-fat diet (HFD) on Wistar rats, 60 male Wistar rats were randomly divided into six groups (n = 10): Control group, SiNPs group, HFD group, 2 mg kg^-1 SiNPs + HFD group, 5 mg kg^-1 SiNPs + HFD group and 10 mg kg^-1 SiNPs + HFD group. HFD was administrated for 2 weeks for the rats in advance and SiNPs were supplied every 3 d for 48 d subsequently. The present study illustrated that both HFD and SiNPs could decrease sperm concentration, mobility rates, increase abnormality rates, damage testicular structure, reduce spermatogonium numbers and spermatoblast numbers, reduce ATP levels, and affect expression of regulatory factors for meiosis in testis. HFD and SiNPs further damaged the sperm and lowered the ATP level and expression of factors associated with meiotic signaling pathway compared with the HFD without SiNPs in testicular tissue of Wistar rats. These results suggested that SiNPs significantly promoted reproductive toxicity induced by HFD in Wistar rats, which provides novel experimental evidence and an explanation for magnified reproductive toxicity triggered by SiNPs in HFD rats.

In vitro effects of endosulfan-based insecticides on mammalian sperm

Endosulfan is an organochloride insecticide extensively used in several countries to protect crops from pests. As several studies indicate that endosulfan can affect human and animal development, the aim of this study was to analyse whether sperm parameters and the process of chromatin decondensation could be altered by endosulfan in mice sperm. Spermatozoa from cauda epididymis were obtained from mature male mice and incubated in the presence of two commercial formulations (CFs) of endosulfan (Master® and Zebra Ciagro®) or the active ingredient (AI) alone. A significant decrease in the percentage motility and viability of spermatozoa with respect to controls was found. In vitro decondensation was performed in the presence of glutathione and heparin. Spermatozoa incubated with the AI, endosulfan Master® and endosulfan Zebra Ciagro® showed an increase in chromatin decondensation. In addition, the TUNEL assay showed that DNA fragmentation was significantly higher when sperm were incubated with either one of the CFs when compared to the AI or controls. The ultrastructure analysis of sperm cells showed evident changes in the structure of the plasma and acrosome membranes of sperm incubated with endosulfan AI or the CFs. These results suggest that endosulfan can affect sperm integrity and in vitro chromatin decondensation as well as DNA fragmentation.

A combined NMR- and HPLC-MS/MS-based metabolomics to evaluate the metabolic perturbations and subacute toxic effects of endosulfan on mice

Endosulfan is the newly persistent organic pollutants (POPs) added to the Stockholm Convention as its widespread use, persistence, bioaccumulation, long-range transport, endocrine disruption, and toxicity related to various adverse effects. In the present study, male mice were administrated endosulfan at 0, 0.5, and 3.5 mg/kg by gavage for 2 weeks. ¹H-NMR-based urinary metabolomics, HPLC-MS/MS-based targeted serum metabolomics, clinical analysis, and histopathology techniques were employed to evaluate the metabolic perturbations of subacute endosulfan exposure. Endosulfan exposures resulted in weight loss, liver inflammation and necrosis, and alterations in serum amino acids and urine metabolomics. Based on altered metabolites, several significantly perturbed pathways were identified including glycine, serine, and threonine metabolism; TCA cycle; pyruvate metabolism; glycolysis or gluconeogenesis; glycerophospholipid metabolism; and glyoxylate and dicarboxylate metabolism. Such pathways were highly related to amino acid metabolism, energy metabolism, and lipid metabolism. In addition, metabolomic results also demonstrated that gut microbiota was remarkably altered after endosulfan exposure. These observations may provide novel insight into revealing the potential toxic mechanism and evaluating the health risk of endosulfan exposure at metabolomic level.