Genome-wide transcriptome analysis reveals that Bisphenol A activates immune responses in skeletal muscle.

Cumulative human exposure to the environmental toxin, bisphenol A (BPA), has raised important health concerns in recent decades. However, the direct genomic regulation of BPA in skeletal muscles and its clinical significance are poorly understood. Therefore, we conducted a genome-wide transcriptome analysis after daily oral administration of BPA at the lowest observed adverse-effect level (LOAEL, 50 mg/kg) in male mice for six weeks to explore the gene-expression regulations in skeletal muscle induced by BPA. The primary Gene Ontology terms linked to BPA-dependent, differentially expressed genes at LOAEL comprised adaptive-immune response, positive regulation of T cell activation, and immune system process. The gene-set enrichment analysis disclosed increased complement-associated genes [complement components 3 (C3) and 4B, complement factor D, complement receptor 2, and immunoglobulin lambda constant 2] in the group administered with BPA, with a false-discovery rate of <0.05. Subsequent validation analysis conducted in BPA-fed animal skeletal muscle tissue and in vitro experiments confirmed that BPA induced immune activation, as evidenced by increased levels of C3 and C4α proteins in mice, C2C12 myoblasts, and mouse skeletal muscle cells. In addition, BPA markedly upregulated the transcription of tumor necrosis factor-α (Tnfα) in C2C12 myoblasts and mouse skeletal muscle cells, which was substantially inhibited by 5z-7-oxozeanol and parthenolide, providing further evidence of BPA-induced inflammation in muscle cells. Our bioinformatics and subsequent animal and in vitro validations demonstrate that BPA can activate inflammation in skeletal muscle, which could be a risk factor underlying chronic muscle weakness and wastage.

Short-term storage of semen samples in acidic extender increases the proportion of females in pigs.

BACKGROUND: Sex preselection is a desired goal of the animal industry to improve production efficiency, depending on industry demand. In the porcine industry, there is a general preference for pork from female and surgically castrated male pigs. Therefore, the birth of more females than males in a litter leads to economic benefits and improved animal welfare in the pig production industry. Our previous study suggested that the porcine semen extender (BTS) adjusted to pH 6.2 maximises the differences in viability between X-chromosome-bearing (X) spermatozoa and Y-chromosome-bearing (Y) spermatozoa without affecting sperm's functional parameters. In this study we aimed to evaluate whether the pH 6.2 extender is applicable at the farm level for increasing the number of female piglets without a decline in spermatozoa fertility. Artificial insemination (AI) was carried out with spermatozoa stored at pH 6.2 and pH 7.2 (original BTS) at day 1 and day 2 of storage. Next, the functional parameters of the spermatozoa, litter size, farrowing rate, and female-to-male ratio of offspring were determined. RESULTS: Although sperm motility decreased significantly after 2 d of storage, the viability of spermatozoa was preserved at pH 6.2 for 3 d. There was no significant difference in the farrowing rate and average litter size between the group inseminated with the spermatozoa stored in (pH 7.2) and that inseminated with spermatozoa stored in acidic BTS. The percentage of female piglets was approximately 1.5-fold higher in sows inseminated on day 1 in the pH 6.2 than in the pH 7.2 group. Furthermore, although there was no significant difference in the female-to-male ratio, the percentage of female piglets born was slightly higher in the pH 6.2 group than in the pH 7.2 group on day 2. CONCLUSIONS: The method optimised in our study is simple, economical, and may enhance the number of female births without any decline in spermatozoa fertility.

Bisphenol A exposure increases epididymal susceptibility to infection in mice.

Male fertility is linked with several well-orchestrated events including spermatogenesis, epididymal maturation, capacitation, the acrosome reaction, fertilization, and beyond. However, the detrimental effects of bisphenol A (BPA) on sperm maturation compared to spermatogenesis and sperm cells remain unclear. Therefore, this study was to investigate whether pubertal exposure to BPA induces male infertility via interruption of the immune response in the epididymis. CD-1 male mice (5 weeks old) were treated daily with vehicle (corn oil) and 50 mg BPA/kg-BW for 6 weeks by oral gavage. Following BPA exposure, we observed decreased intraepithelial projection of basal cells, indicative of changes to the luminal environment. We also observed decreased projection of macrophages and protrusion of apoptotic cells into the lumen induced by incomplete phagocytosis of apoptotic cells in the caput epididymis. Exposure to BPA also reduced the anti- and pro-inflammatory cytokines IL-10, IL-6, IFN-γ, and IL-7 in the epididymis, while the chemotaxis-associated cytokines CCL12, CCL17, CXCL16, and MCP-1 increased. This study suggests two possible mechanisms for BPA induction of male infertility. First, exposure to BPA may induce an imbalance of immune homeostasis by disrupting the ability of basal cells to perceive environmental changes. Second, exposure to BPA may lead to collapse of macrophage phagocytosis via downregulation of intraepithelial projection and inflammatory-related cytokines. In conclusion, the observed potential pathways can lead to autoimmune disorders such epididymitis and orchitis.

Endocrine-Disrupting Chemicals and Infectious Diseases: From Endocrine Disruption to Immunosuppression.

Endocrine-disrupting chemicals (EDCs) are hormonally active compounds in the environment that interfere with the body's endocrine system and consequently produce adverse health effects. Despite persistent public health concerns, EDCs remain important components of common consumer products, thus representing ubiquitous contaminants to humans. While scientific evidence confirmed their contribution to the severity of Influenza A virus (H1N1) in the animal model, their roles in susceptibility and clinical outcome of the coronavirus disease (COVID-19) cannot be underestimated. Since its emergence in late 2019, clinical reports on COVID-19 have confirmed that severe disease and death occur in persons aged ≥65 years and those with underlying comorbidities. Major comorbidities of COVID-19 include diabetes, obesity, cardiovascular disease, hypertension, cancer, and kidney and liver diseases. Meanwhile, long-term exposure to EDCs contributes significantly to the onset and progression of these comorbid diseases. Besides, EDCs play vital roles in the disruption of the body's immune system. Here, we review the recent literature on the roles of EDCs in comorbidities contributing to COVID-19 mortality, impacts of EDCs on the immune system, and recent articles linking EDCs to COVID-19 risks. We also recommend methodologies that could be adopted to comprehensively study the role of EDCs in COVID-19 risk.

Role of Insulin in Health and Disease: An Update.

Insulin is a polypeptide hormone mainly secreted by ß cells in the islets of Langerhans of the pancreas. The hormone potentially coordinates with glucagon to modulate blood glucose levels; insulin acts via an anabolic pathway, while glucagon performs catabolic functions. Insulin regulates glucose levels in the bloodstream and induces glucose storage in the liver, muscles, and adipose tissue, resulting in overall weight gain. The modulation of a wide range of physiological processes by insulin makes its synthesis and levels critical in the onset and progression of several chronic diseases. Although clinical and basic research has made significant progress in understanding the role of insulin in several pathophysiological processes, many aspects of these functions have yet to be elucidated. This review provides an update on insulin secretion and regulation, and its physiological roles and functions in different organs and cells, and implications to overall health. We cast light on recent advances in insulin-signaling targeted therapies, the protective effects of insulin signaling activators against disease, and recommendations and directions for future research.

Multigenerational and transgenerational impact of paternal bisphenol A exposure on male fertility in a mouse model.

STUDY QUESTION: How does paternal exposure to bisphenol A (BPA) affect the fertility of male offspring in mice in future generations? SUMMARY ANSWER: Paternal exposure to BPA adversely affects spermatogenesis, several important sperm functions and DNA methylation patterns in spermatozoa, which have both multigenerational (in F0 and F1) and partial transgenerational (mainly noticed in F2, but F3) impacts on the fertility of the offspring. WHAT IS KNOWN ALREADY: BPA, a synthetic endocrine disruptor, is used extensively to manufacture polycarbonate plastics and epoxy resins. Growing evidence suggests that exposure to BPA during the developmental stages results in atypical reproductive phenotypes that could persist for generations to come. STUDY DESIGN, SIZE, DURATION: CD-1 male mice (F0) were treated with BPA (5 or 50 mg/kg body weight per day (bw/day)) or ethinylestradiol (EE) (0.4 µg/kg bw/day) for 6 weeks. Control mice were treated with vehicle (corn oil) only. The treated male mice were bred with untreated female mice to produce first filial generation (F1 offspring). The F2 and F3 offspring were produced similarly, without further exposure to BPA. PARTICIPANTS/MATERIALS, SETTING, METHODS: Histological changes in the testis along with functional, biochemical and epigenetic (DNA methylation) properties of spermatozoa were investigated. Subsequently, each parameter of the F0-F3 generations was compared between BPA-treated mice and control mice. MAIN RESULTS AND THE ROLE OF CHANCE: Paternal BPA exposure disrupted spermatogenesis by decreasing the size and number of testicular seminiferous epithelial cells, which eventually led to a decline in the total sperm count of F0-F2 offspring (P < 0.05). We further showed that a high BPA dose decreased sperm motility in F0-F2 males by mediating the overproduction of reactive oxygen species (F0-F1) and decreasing intracellular ATP (F0-F2) in spermatozoa (P < 0.05). These changes in spermatozoa were associated with altered global DNA methylation patterns in the spermatozoa of F0-F3 males (P < 0.05). Furthermore, we noticed that BPA compromised sperm fertility in mice from the F0-F2 (in the both dose groups) and F3 generations (in the high-dose group only). The overall reproductive toxicity of BPA was equivalent to or higher (high dose) than that of the tested dose of EE. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: Further research is required to determine the variables (e.g. lowest BPA dose) that are capable of producing changes in sperm function and fertility in future generations. WIDER IMPLICATIONS OF THE FINDINGS: These results may shed light on how occupational exposure to BPA can affect offspring fertility in humans. STUDY FUNDING/COMPETING INTEREST(S): This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (Grant No. NRF-2018R1A6A1A03025159). M.S.R. was supported by Korea Research Fellowship Program through the NRF funded by the Ministry of Science and ICT (Grant No. 2017H1D3A1A02013844). There are no competing interests.

Attenuation of Acute Intracerebral Hemorrhage-Induced Microglial Activation and Neuronal Death Mediated by the Blockade of Metabotropic Glutamate Receptor 5 In Vivo.

The activation of microglia in response to intracerebral hemorrhagic stroke is one of the principal components of the progression of this disease. It results in the formation of pro-inflammatory cytokines that lead to neuronal death, a structural deterioration that, in turn interferes with functional recovery. Metabotropic glutamate receptor 5 (mGluR5) is highly expressed in reactive microglia and is involved in the pathological processes of brain disorders, but its role in intracerebral hemorrhage (ICH) remains unknown. We hypothesized that mGluR5 regulates microglial activation and ICH maintenance. In this study, collagenase-induced ICH mice received a single intraperitoneal injection of the mGluR5 antagonist-, MTEP, or vehicle 2 h after injury. We found that acute ICH upregulated mGluR5 and microglial activation. mGluR5 was highly localized in reactive microglia in the peri-hematomal cortex and striatum on days 3 and 7 post-ICH. The MTEP-mediated pharmacological inhibition of mGluR5 in vivo resulted in the substantial attenuation of acute microglial activation and IL-6, and TNF-α release. We also showed that the blockade of mGluR5 markedly reduced cell apoptosis, and neurodegeneration and markedly elevated neuroprotection. Furthermore, the MTEP-mediated inhibition of mGluR5 significantly reduced the lesion volume and improved functional recovery. Taken together, our results demonstrate that ICH injury enhances mGluR5 expression in the acute and subacute stages and that mGluR5 is highly localized in reactive microglia. The blockade of mGluR5 reduces ICH-induced acute microglial activation, provides neuroprotection and promotes neurofunctional recovery after ICH. The inhibition of mGluR5 may be a relevant therapeutic target for intracerebral hemorrhagic stroke.

Bisphenol A affects the maturation and fertilization competence of spermatozoa.

Although there are numerous studies on bisphenol A (BPA) on the testis and spermatozoa, the effect of BPA on the physiological link between the testis and maturation of spermatozoa has not been studied. To provide an optimal environment (acidic pH) for sperm maturation in the epididymis, clear cells secrete protons and principal cells reabsorb bicarbonate and the secreted proton. Because of its crucial role in sperm maturation and fertility, functional changes in the epididymis following BPA exposure must be considered to fully understand the mechanisms of BPA on male fertility. Here, we identified the adverse effects of BPA exposure during puberty in male mice. CD-1 male mice were gavaged daily with vehicle (corn oil) and 50 mg BPA/kg-BW for 6 weeks. We determined the changes in epididymis, functional sperm parameters including motility, capacitation status, tyrosine phosphorylation, and fertility-related protein expression and in vitro and in vivo fertility rate following BPA exposure. Expression of vacuolar-type H + -ATPase is necessary for the secretion of protons by clear cells of the caput epididymis and was directly down-regulated following BPA exposure, while there were no changes in the other epithelial cell types in the epididymis. Also, pERK 1/2 signaling pathway was increased significantly in the caput epididymis following BPA exposure. Consequently, the luminal pH slightly increased, resulting in premature capacitation of spermatozoa. Moreover, there was a significant loss of the acrosomal membrane following an increase of protein tyrosine phosphorylation, while PKA activity decreased during sperm capacitation. Fertility-related proteins also showed aberrant expression upon BPA exposure. These modifications resulted in decreased male fertility in vitro and in vivo.

Paternal Exposure to Bisphenol-A Transgenerationally Impairs Testis Morphology, Germ Cell Associations, and Stemness Properties of Mouse Spermatogonial Stem Cells.

Bisphenol-A (BPA) exposure in an adult male can affect the reproductive system, which may also adversely affect the next generation. However, there is a lack of comprehensive data on the BPA-induced disruption of the association and functional characteristics of the testicular germ cells, which the present study sought to investigate. Adult male mice were administered BPA doses by gavage for six consecutive weeks and allowed to breed, producing generations F1-F4. Testis samples from each generation were evaluated for several parameters, including abnormal structure, alterations in germ cell proportions, apoptosis, and loss of functional properties of spermatogonial stem cells (SSCs). We observed that at the lowest-observed-adverse-effect level (LOAEL) dose, the testicular abnormalities and alterations in seminiferous epithelium staging persisted in F0-F2 generations, although a reduced total spermatogonia count was found only in F0. However, abnormalities in the proportions of germ cells were observed until F2. Exposure of the male mice (F0) to BPA alters the morphology of the testis along with the association of germ cells and stemness properties of SSCs, with the effects persisting up to F2. Therefore, we conclude that BPA induces physiological and functional disruption in male germ cells, which may lead to reproductive health issues in the next generation.

Neural stem cell-derived factors inhibit the growth and invasion of U87 stem-like cells in vitro.

Glioma is one of the most common and aggressive tumors in the brain. Significant attention has been paid to the potential use of neural stem/progenitor cells (NSCs/NPCs) as delivery vehicles to cure gliomas. However, whether the NSCs/NPCs or the factors they produced could make a contribution still remains to be seen. In this study, we focused on the inhibitory effects of the factors produced by NSCs/NPCs on the biological behavior of the glioma stem-like cell in vitro. The human glioma cell line U87 was selected and the U87 stem-like cells were addressed. After being cultured in the NSC condition medium (NSC-CM), the viability and proliferation of U87 stem-like cells were significantly reduced. The invasion of U87 stem-like cells and the migration of U87 cells were also significantly decreased. However, no significant change was observed in regard to the astrocytic differentiation of U87 stem-like cells. These indicated that NSCs/NPCs produced some factors and had an inhibitory effect on the growth and invasion but not the terminal differentiation of U87 stem-like cells. It is worth paying attention to NSCs/NPCs as a high-potential candidate for glioma treatment.

Research update and opportunity of non-hormonal male contraception: Histone demethylase KDM5B-based targeting.

With the continued increase in global human population, diverse contraception approaches have become increasingly essential, including non-hormonal male contraception. Non-hormonal approaches to contraception are very convenient; however, such options are limited because data regarding the identification and characterization of tissue/cell-specific targets and appropriate small molecule candidate contraceptives are lacking. Based on in-silico studies of genomics, transcriptomics, and proteomics, performed by mining datasets in PubMed, we first reviewed testis-, epididymis-, and germline cell-specific genes/proteins, with the aim of presenting evidence that many of these could become 'druggable' targets for the development of non-hormonal male contraceptives in the future. Although many hurdles remain before the successful therapeutic use of non-hormonal contraceptive, to facilitate this approach, we describe here the changing perspectives on several potential non-hormonal contraceptives (e.g. small molecules, plant extracts, etc.) that are under development; continued effort may yield marketable products. Further, we highlight specific enzymes within the histone lysine demethylase subfamily that play a central role in germ line regulation. In particular, we focused on several prospective candidate small-molecules suggested to interact with the catalytic domain of histone lysine demethylase KDM5B, which is ubiquitously expressed in the testis/spermatozoa of both mice and human.

Functional and Proteomic Alterations of F1 Capacitated Spermatozoa of Adult Mice Following Gestational Exposure to Bisphenol A.

Studies regarding bisphenol A (BPA) exposure and male (in)fertility have conventionally focused on modifications in ejaculated spermatozoa function from exposed individuals. However, mammalian spermatozoa are incapable of fertilization prior to achieving capacitation, the penultimate step in maturation. Therefore, it is necessary to investigate BPA-induced changes in capacitated spermatozoa and assess the consequences on subsequent fertilization. Here, we demonstrate the effect of gestational BPA exposure (50 µg/kg bw/day, 5 mg/kg bw/day, and 50 mg/kg bw/day) on the functions, biochemical properties, and proteomic profiles of F1 capacitated spermatozoa from adult mice. The data showed that high concentrations of BPA inhibited motility, motion kinematics, and capacitation of spermatozoa, perhaps because of increased lipid peroxidation and protein tyrosine nitration, and decreased intracellular ATP levels and protein kinase-A activity in spermatozoa. We also found that BPA compromised the rates of fertilization and early embryonic development. Differentially expressed proteins identified between BPA-exposed and control groups play a critical role in energy metabolism, stress responses, and fertility. Protein function abnormalities were responsible for the development of several diseases according to bioinformatics analysis. On the basis of these results, gestational exposure to BPA may alter capacitated spermatozoa function and the proteomic profile, ultimately affecting their fertility potential.

Applications of capacitation status for litter size enhancement in various pig breeds.

OBJECTIVE: Several studies have reported the development of new molecular methods for the prognosis and diagnosis of male fertility based on biomarkers aimed at overcoming the limitations of conventional male fertility analysis tools. However, further studies are needed for the field application of these methods. Therefore, alternative methods based on existing semen analysis methods are required to improve production efficiency in the animal industry. METHODS: we examined the possibility of improving litter size in various pig breeds using combined Hoechst 33258/chlortetracycline fluorescence (H33258/CTC) staining. The correlation between field fertility and capacitation status by combined H33258/CTC staining in different ejaculates spermatozoa (n = 3) from an individual boar (20 Landrace, 20 Yorkshire, and 20 Duroc) was evaluated as well as overall accuracy. RESULTS: The acrosome reacted (AR) pattern after capacitation (%) was positively correlated with the litter size of Landrace, Yorkshire, and Duroc pigs and the overall accuracy was 75%, 75%, and 70% in Landrace, Yorkshire, and Duroc pigs, respectively. The difference (Δ) in AR pattern before and after capacitation was positively correlated with the litter size of Landrace, Yorkshire, and Duroc pigs and the overall accuracy was 80%, 65%, and 55% in Landrace, Yorkshire, and Duroc pigs, respectively. However, the difference (Δ) in capacitated (B) pattern before and after capacitation was negatively correlated with the litter size of Landrace pigs and the overall accuracy was 75%. Moreover, average litter size was significantly altered according to different combined H33258/CTC staining parameters. CONCLUSION: These results show that combined H33258/CTC staining may be used to predict male fertility in various breeds. However, the selection of specific efficiency combined H33258/CTC staining parameters requires further consideration. Taken together, these findings suggest that combined H33258/CTC staining may constitute an alternative method for predicting male fertility until such time as fertility-related biomarkers are further validated.

Prediction of male fertility using capacitation-associated proteins in spermatozoa.

Infertility and subfertility account for huge economic losses in the animal industry; indeed, 50% of animal breeding failure is associated with male infertility. Approximately 70% of cattle and 90% of pig livestock are currently produced by artificial insemination. Therefore, breeding-male selection is extremely important for the genetic benefits of progeny. Although conventional semen analysis provides an initial measure of male fertility, its clinical value is questionable. Proteomics approaches recently identified candidate protein markers in spermatozoa for evaluating male fertility. Fertility-related proteins in capacitated boar spermatozoa were shown to predict boar fertility more precisely then those detected in ejaculated spermatozoa, which motivated the development of more accurate and sensitive tools for the assessment of male fertility in relation to sperm function and fertilization. Although protein markers in spermatozoa are capable of discriminating fertile and infertile males, clinical trials are required to validate their predictive utility. This review outlines recent findings regarding the capacitation-related proteome of spermatozoa, and discusses how these proteins may be utilized to better understand the fertility of domestic animals.

Systematic review and meta-analysis of the efficacy of different exercise programs in pilocarpine induced status epilepticus models.

PURPOSE: To conduct a systematic review and meta-analysis of studies testing exercise in animal models of pilocarpine induced status epilepticus (SE) and to compare the efficacy of different training strategies used in those studies. METHODS: We searched 2 online databases (Pubmed and Web of Science) for studies analyzing the efficacy of different trainings in pilocarpine-induced SE models. Training was categorized into forced physical training (PT), voluntary PT and resistance PT. Two reviewers independently extracted data on study quality, behavioral seizures, and histological, chemical and cognitive outcomes. Data were pooled by means of a meta-analysis. RESULTS: Among 17 selected studies; 174 animals from 8 studies with 10 comparison groups showed that exercise intervention after induction of SE significantly decreased spontaneous recurrent seizures with [mean difference (MD)=-1.80, 95% confidence interval (CI): -3.22, -0.37, p=0.02] and 60 animals showed statistically significant decrease in latency in Morris water maze (standardized mean difference (SMD)=-2.57, 95% CI: -4.06, -1.08, p=0.0007). Although not statistically significant, still a remarkable increase in number of CA1 neurons and hippocampal BDNF level (MD=2.27, [95% CI: -1.20, 5.73], p=0.19, SMD=1.07, [95% CI: -0.36, 2.51], p=0.14 respectively) and a decrease in mossy fibers sprouting (SMD=-1.03, [95% CI: -3.06, 1.00], p=0.32) were observed. PT interventions in 72 animals before induction of SE showed favorable increase in latency to develop SE (MD=8.34, [95% CI: -3.10, 19.78], p=0.15) but no remarkable improvements in latency for the first motor sign and motor signs intensity. CONCLUSIONS: PT after SE reduces the recurrent seizures and improves the morphological, biochemical and cognitive profiles of pilocarpine epileptic models. Resistance PT was identified as particularly effective in reducing behavioral seizures. The efficacy of training was also dependent upon duration.

Discovery of predictive biomarkers for litter size in boar spermatozoa.

Conventional semen analysis has been used for prognosis and diagnosis of male fertility. Although this tool is essential for providing initial quantitative information about semen, it remains a subject of debate. Therefore, development of new methods for the prognosis and diagnosis of male fertility should be seriously considered for animal species of economic importance as well as for humans. In the present study, we applied a comprehensive proteomic approach to identify global protein biomarkers in boar spermatozoa in order to increase the precision of male fertility prognoses and diagnoses. We determined that l-amino acid oxidase, mitochondrial malate dehydrogenase 2, NAD (MDH2), cytosolic 5'-nucleotidase 1B, lysozyme-like protein 4, and calmodulin (CALM) were significantly and abundantly expressed in high-litter size spermatozoa. We also found that equatorin, spermadhesin AWN, triosephosphate isomerase (TPI), Ras-related protein Rab-2A (RAB2A), spermadhesin AQN-3, and NADH dehydrogenase [ubiquinone] iron-sulfur protein 2 (NDUFS2) were significantly and abundantly expressed in low-litter size spermatozoa (>3-fold). Moreover, RAB2A, TPI, and NDUFS2 were negatively correlated with litter size, whereas CALM and MDH2 were positively correlated. This study provides novel biomarkers for the prediction of male fertility. To the best of our knowledge, this is the first work that shows significantly increased litter size using male fertility biomarkers in a field trial. Moreover, these protein markers may provide new developmental tools for the selection of superior sires as well as for the prognosis and diagnosis of male fertility.

Determination of Highly Sensitive Biological Cell Model Systems to Screen BPA-Related Health Hazards Using Pathway Studio.

Bisphenol-A (BPA) is a ubiquitous endocrine-disrupting chemical. Recently, many issues have arisen surrounding the disease pathogenesis of BPA. Therefore, several studies have been conducted to investigate the proteomic biomarkers of BPA that are associated with disease processes. However, studies on identifying highly sensitive biological cell model systems in determining BPA health risk are lacking. Here, we determined suitable cell model systems and potential biomarkers for predicting BPA-mediated disease using the bioinformatics tool Pathway Studio. We compiled known BPA-mediated diseases in humans, which were categorized into five major types. Subsequently, we investigated the differentially expressed proteins following BPA exposure in several cell types, and analyzed the efficacy of altered proteins to investigate their associations with BPA-mediated diseases. Our results demonstrated that colon cancer cells (SW480), mammary gland, and Sertoli cells were highly sensitive biological model systems, because of the efficacy of predicting the majority of BPA-mediated diseases. We selected glucose-6-phosphate dehydrogenase (G6PD), cytochrome b-c1 complex subunit 1 (UQCRC1), and voltage-dependent anion-selective channel protein 2 (VDAC2) as highly sensitive biomarkers to predict BPA-mediated diseases. Furthermore, we summarized proteomic studies in spermatozoa following BPA exposure, which have recently been considered as another suitable cell type for predicting BPA-mediated diseases.

A novel approach to assessing bisphenol-A hazards using an in vitro model system.

BACKGROUND: Although the toxicological impacts of the xenoestrogen bisphenol-A (BPA) have been studied extensively, but the mechanism of action is poorly understood. Eventually, no standard method exists for evaluating the possible health hazards of BPA exposure. Considering mice spermatozoa as a potential in vitro model, we investigated the effects of BPA exposure (0.0001, 0.01, 1, and 100 µM for 6 h) on spermatozoa and the related mechanisms of action. The same doses were also employed to evaluate protein profiles of spermatozoa as a means to monitor their functional affiliation to diseases. RESULTS: Our results demonstrated that high concentrations of BPA negatively affect sperm motility, viability, mitochondrial functions, and intracellular ATP levels by activating the mitogen-activated protein kinase, phosphatidylinositol 3-kinase, and protein kinase-A pathways. Moreover, short-term exposure of spermatozoa to high concentrations of BPA induced differential expressions of 24 proteins. These effects appeared to be caused by protein degradation and phosphorylation in spermatozoa. Proteins differentially expressed in spermatozoa from BPA treatment groups are putatively involved in the pathogenesis of several diseases, mainly cancer, carcinoma, neoplasm, and infertility. CONCLUSIONS: Based on these results, we propose that BPA adversely affects sperm function by the activation of several kinase pathways in spermatozoa. In addition, BPA-induced changes in the sperm proteome might be partly responsible for the observed effects in spermatozoa, subsequently involve in the pathogenesis of many diseases. Therefore, we anticipated that current strategy might broadly consider for the health hazards assessment of other toxicological agents.

Diagnosis and prognosis of male infertility in mammal: the focusing of tyrosine phosphorylation and phosphotyrosine proteins.

Male infertility refers to the inability of a man to achieve a pregnancy in a fertile female. In more than one-third of cases, infertility arises due to the male factor. Therefore, developing strategies for the diagnosis and prognosis of male infertility is critical. Simultaneously, a satisfactory model for the cellular mechanisms that regulate normal sperm function must be established. In this regard, tyrosine phosphorylation is one of the most common mechanisms through which several signal transduction pathways are adjusted in spermatozoa. It regulates the various aspects of sperm function, for example, motility, hyperactivation, capacitation, the acrosome reaction, fertilization, and beyond. Several recent large-scale studies have identified the proteins that are phosphorylated in spermatozoa to acquire fertilization competence. However, most of these studies are basal and have not presented an overall mechanism through which tyrosine phosphorylation regulates male infertility. In this review, we focus of this mechanism, discussing most of the tyrosine-phosphorylated proteins in spermatozoa that have been identified to date. We categorized tyrosine-phosphorylated proteins in spermatozoa that regulate male infertility using MedScan Reader (v5.0) and Pathway Studio (v9.0).