Impact of chitosan administration on titanium dioxide nanoparticles induced testicular dysfunction.

The potential reproductive toxic effects of oral TiO2 NPs in adult male rats as well as the possible alleviation of chitosan administration was investigated. Animals were allocated to four groups; the first group received deionized water and was assigned as a control group. In the second group, rats received chitosan at a dose of 5 mg/kg BW/day. The third group was designed for administration of TiO2 NPs at a dose of 150 mg/kg BW/day (1/80 LD50). Rats in the fourth group received both TiO2 NPs and chitosan. After 14 days, TiO2 NPs induced testicular lipid peroxidation as well as oxidative stress. Nano-titanium significantly upregulated genes that encode apoptosis and inflammation in testicular tissue. Moreover, it induced histological alteration in the testicular structure with impairment in spermatogenesis via reduction of PCNA immune-staining. Chitosan administration significantly improved the activities of testicular GPx, SOD, and CAT enzymes. In addition, it significantly down-regulated the relative expressions of pro-apoptotic and pro-inflammatory testicular genes. Chitosan was able to improve the testicular architecture as well as spermatogenesis. The current study revealed the capability of chitosan to ameliorate nano-titanium induced testicular toxicity. Thus, attention should be given to the extensive consumption of nano-titanium particles.

Effects of Bisphenol A on expression of genes related to amino acid transporters, insulin- like growth factor, aquaporin and amino acid release by porcine trophectoderm cells.

The peri-implantation period of pregnancy is critical for conceptus development, implantation, and signaling for establishment of pregnancy. This study evaluated the effects of bisphenol A (BPA) on proliferation, adhesion, and migration of porcine trophectoderm (pTr2) cells, expression of transporters of arginine and synthesis of amino acids. All concentrations of BPA decreased proliferation and adhesion of pTr2 cells after 96 h compared to the control group. Lower concentrations of BPA (1 × 10-9, 1 × 10-8, 10-7M) increased (P < 0.05), but higher concentrations of BPA (1 × 10-5, 1 × 10-4 M) decreased migration of pTr2 cells. BPA increased expression of SLC7A1 mRNA at lower concentrations (1 × 10-9 to 1 × 10-6M) and SL7A6, another cationic acid transporter, at higher concentrations (1 × 10-5, 1 × 10-4 M). BPA also down-regulated the expression of IGF1 and IGF1 receptor at concentrations of 1 × 10-7 to 1 × 10-4 M compared to the control group. The expression of mRNAs for aquaporins (AQP) 3 and 4 were reduced at all concentrations of BPA, but at lower concentrations of BPA, (1 × 10-9 to 1 × 10-8M) expression of AQP9 mRNA increased and the expression of AQP11 was not affected by BPA (P > 0.05). There was an inhibitory effect of BPA on the release of synthesis of asparagine, threonine, taurine, tryptophan, and ornithine into the culture medium by pTr2 cells. Collectively, BPA adversely affected the expression of transporters for cationic amino acids like arginine, as well as AQPs, IGF1, and IGF1R associated with proliferation, migration, and adhesion of pTr2 cells. Those adverse effects would likely increase pregnancy losses during the peri-implantation period of pregnancy.

Molecular, physiological and behavioral characterization of the heterozygous Df[h15q13]/+ mouse model associated with the human 15q13.3 microdeletion syndrome.

The human 15q13.3 microdeletion syndrome (DS) is caused by a heterozygous microdeletion (MD) affecting six genes: FAN1; MTMR10; TRPM1; KLF13; OTUD7A; and CHRNA7. Carriers are at risk for intellectual disability, epilepsy, autism spectrum disorder, and schizophrenia. Here we used the Df[h15q13]/+ mouse model with an orthologous deletion to further characterize molecular, neurophysiological, and behavioral parameters that are relevant to the 15q13.3 DS. First, we verified the expression and distribution of the α7 nicotinic acetylcholine receptor (nAChR), a gene product of the CHRNA7, in cortical and subcortical areas. Results revealed similar mRNA distribution pattern in wildtype (WT) and heterozygous (Het) mice, with about half the number of α7 nAChR binding sites in mutants. Hippocampal recordings showed similar input/output responses of field excitatory post-synaptic potentials and theta-burst induced long-term potentiation in WT and Het mice. Het males exhibited impaired spatial learning acquisition in the Barnes Maze. Indicative of increased seizure susceptibility, Het mice developed secondary seizures after 6-Hz corneal stimulation, and had significantly increased sensitivity to the chemoconvulsant pentylenetetrazol resulting in increased spiking in hippocampal EEG recordings. Basal mRNA expression of brain derived neurotrophic factor and activity regulated immediate early genes (c-fos, Arc, Erg-1 and Npas4) during adolescence, a critical period of brain maturation, was unaffected by genotype. Thus, the MD did not show gross neuroanatomical, molecular, and neurophysiological abnormalities despite deficits in spatial learning and increased susceptibility to seizures. Altogether, our results verify the phenotypic profile of the heterozygous Df[h15q13]/+ mouse model and underscore its translational relevance for human 15q13.3 DS.

Central and peripheral immune responses to low-dose lipopolysaccharide in a mouse model of the 15q13.3 microdeletion.

Carriers of the human 15q13.3 microdeletion (MD) present with a variable spectrum of neuropathological phenotypes that range from asymptomatic to severe clinical outcomes, suggesting an interplay of genetic and non-genetic factors. The most common 2 MB 15q13.3 MD encompasses six genes (MTMR10, FAN1, TRPM1, KLF13, OTUD7A, and CHRNA7), which are expressed in neuronal and non-neuronal tissues. The nicotinic acetylcholine receptor (nAChR) α7, encoded by CHRNA7, is a key player in the cholinergic anti-inflammatory pathway, and the transcription factor KLF13 is also involved in immune responses. Using a mouse model with a heterozygous deletion of the orthologous region of the human 15q13.3 (Df[h15q13]/+), the present study examined peripheral and central innate immune responses to an acute intraperitoneal (i.p.) injection of the bacteriomimetic, lipopolysaccharide (LPS) (100 µg/kg) in adult heterozygous (Het) and wildtype (WT) mice. Serum levels of inflammatory markers were measured 2 h post injection using a Multiplex assay. In control saline injected animals, all measured cytokines were at or below detection limits, whereas LPS significantly increased serum levels of interleukin 1beta (IL-1ß), tumor necrosis factor alpha (TNF-α), IL-6 and IL-10, but not interferon-γ. There was no effect of genotype but a sexual dimorphic response for TNF-α, with females exhibiting greater LPS-induced TNF-α serum levels than males. In situ hybridization revealed similar increases in LPS-induced c-fos mRNA expression in the dorsal vagal complex in all groups. The hippocampal expression of the pro-inflammatory cytokines was evaluated by real-time quantitative PCR. LPS-treatment resulted in significantly increased mRNA expression for IL-1ß, IL-6, and TNF-α compared to saline controls, with no effect of genotype, but a significant sex-effect was detected for IL-1ß. The present study provided no evidence for interactive effects between the heterozygous 15q13.3 MD and a low-dose LPS immune challenge in innate peripheral or central immune responses, although, sex-differential effects in males and females were detected.

Effects of BPA on expression of apoptotic genes and migration of ovine trophectoderm (oTr1) cells during the peri-implantation period of pregnancy.

Bisphenol A (BPA) is an endocrine-disrupting chemical used in the manufacture of many products used daily. In the present study, the effects of BPA (1 × 10-4 to 1 × 10-9 M) on migration and on the expression of some apoptotic genes were examined in vitro using ovine trophectoderm (oTr1) primary cell line. The results revealed that BPA at 1 × 10-9, 1 × 10-8 and 1 × 10-7M increased migration of oTr1 cells, while 1 × 10-6, 1 × 10-5 and 1 × 10-4 M BPA decreased cell migration. Regarding apoptosis, expression of the anti-apoptotic gene Bcl-2 mRNA was greater at 1 × 10-8 and 1 × 10-9 M BPA and was down-regulated at 1 × 10-4 to 1 × 10-7 M BPA; however, expression of pro-apoptotic genes (Bax, cathepsin B, caspase-3 and c-myc) was reduced at the higher concentrations of BPA. Results of this study suggest that BPA may impair implantation by decreasing migration of oTr1 cells and inhibiting apoptosis.

Effects of Bisphenol-A on proliferation and expression of genes related to synthesis of polyamines, interferon tau and insulin-like growth factor 2 by ovine trophectoderm cells.

This study evaluated the effects of bisphenol A (BPA) on proliferation of ovine trophectoderm (oTr1) cells, as well as expression of genes for transport of arginine and synthesis of polyamines. BPA reduced proliferation of oTr1 cells at concentrations of 1 × 10-6, 1 × 10-5, 1 × 10-4 M compared to concentrations of 0, 1 × 10-9, and 1 × 10-8 M at 24 and 96 h of culture. Lower concentrations of BPA significantly increased expression of mRNAs for agmatinase (AGMAT), arginine decarboxylase (ADC), ornithine decarboxylase (ODC1) and solute carrier family 7 member 1 (SLC7A1). Similarly, synthesis of polyamines by oTr1 cells was greatest at lower concentrations of BPA and decreased as the dose of BPA increased. Expression of mRNAs for interferon tau (IFNT) and insulin-like growth factor 2 (IGF2) by oTr1 cells was greater than for controls at 1 × 10-9 M BPA. Overall, the effects of BPA on proliferation and gene expression by oTr1 cells were highly dose-dependent.

Activation of immediate early genes by nicotine after chronic neonatal nicotine exposure in brain areas involved in stress and anxiety responses.

Maternal smoking has negative long-term consequences on affective behaviors, and in rodents, chronic neonatal nicotine exposure (CNN) results in increased anxiety. In rat pups, acute nicotine stimulation activates brain regions associated with stress and anxiety, but chronic nicotine exposure could desensitize of nicotinic acetylcholine receptors, the molecular target of nicotine. Here, we determined whether CNN affected neuronal activation by an acute nicotine challenge. Using in situ hybridization, we analyzed mRNA expression of the immediate-early genes (IEGs) c-Fos, Arc, Egr-1 and Npas4, which are markers for neuronal activation and implicated in synaptic plasticity. Following CNN (6 mg/kg/day) or control treatment from postnatal day (P)1 to P7, an acute i.p. nicotine (0.7 mg/kg) or saline injection (control) was administered on P8, and brains collected after 30 min. In drug-naive pups, acute nicotine stimulated IEGs expression specifically in brain areas associated with innate anxiety including the paraventricular hypothalamic nucleus, central nucleus of the amygdala (CeA), and locus coeruleus (LC). Following CNN, acute nicotine stimulated IEG expression in all three areas, but activation was significantly reduced in the LC (c-Fos, Egr-1, Npas4), and CeA (c-Fos). Notably, nicotine-induced Npas4 expression was greatly diminished in the LC, which may affect inhibitory synapse formation in noradrenergic neurons. Thus, after CNN, neurons located in areas associated with anxiety brain circuitry maintained responsiveness to nicotine, but tolerance differentially developed to nicotine. In the developing brain, repeated activation by nicotine of areas related to limbic pathways could alter circuit connectivity and increase responsiveness to stress and anxiety later in life.