查看更多>>摘要：Polychlorinated biphenyls (PCBs) are persistent and serious organic pollutants and can theoretically form 209 congeners. PCBs can be divided into two categories: dioxin-like (DL) and non-DL (NDL). NDL-PCBs, which lack aryl hydrocarbon receptor affinity, have been shown to perturb the functions of Jurkat T cells, cerebellar granule cells, and uterine cells. Kv1.3 and Kv1.5 channels are important in immune and heart functions, respectively. We investigated the acute effects of 2,2',6-trichlorinated biphenyl (PCB19), an NDL-PCB, on the currents of human Kv1.3 and Kv1.5 channels. PCB19 acutely blocked the Kv1.3 peak currents concentration-dependently with an IC50 of similar to 2 mu M, without changing the steady-state current. The PCB19-induced inhibition of the Kv1.3 peak current occurred rapidly and voltage-independently, and the effect was irreversible, excluding the possibility of genomic regulation. PCB19 increased the time constants of both activation and inactivation of Kv1.3 channels, resulting in the slowing down of both ultra-rapid activation and intrinsic inactivation. However, PCB19 failed to alter the steady-state curves of activation and inactivation. Regarding the Kv1.5 channel, PCB19 affected neither the peak current nor the steady-state current at the same concentrations tested in the Kv1.3 experiments, showing selective inhibition of PCB19 on the Kv1.3 than the Kv1.5. The presented data indicate that PCB19 could acutely affect the human Kv1.3 channel through a non-genomic mechanism, possibly causing toxic effects on various human physiological functions related to the Kv1.3 channel, such as immune and neural systems.
Augustine-Rauch, KarenLiaw, Jiin-JiaGraziano, Michael
7页
查看更多>>摘要：Pexacerfont is a corticotrophin-releasing factor subtype 1 receptor (CRF-1) antagonist developed for potential treatment of anxiety and stress-related disorders. In male rats, pexacerfont caused hepatic enzyme induction leading to increased thyroxine (T4) clearance. When administered to pregnant rats on gestation day 6 to 15, pexacerfont at 300 mg/kg/day (30x mean AUC in humans at 100 mg/day) produced similar effects on thyroid homeostasis with serum T4 and thyroid-stimulating hormone levels that were 0.3-0.5x and 3.3-3.7 x of controls, respectively. At this dose, fetuses of pexacerfont-treated dams presented findings associated with maternal hypothyroidism including growth retardation and increased skeletal alterations. Additionally, there were unexpected great vessel malformations that were mostly derived from the 4th pharyngeal arch artery in 5 (4.3%) fetuses from 3 (15.8%) litters. The etiology was unclear whether the vascular malformations were related to insufficient thyroid hormones or another mechanism. To better understand this relationship, pregnant rats were implanted with a subcutaneous L-thyroxine pellet designed to provide a sustained release of T4 throughout organogenesis in rat embryos (GD 6 to 15; the dosing period of pexacerfont). T4 supplementation produced a near euthyroid state in pexacerfont-treated dams and completely prevented the fetal vascular malformations. These results suggest maternal T4 levels during organogenesis may have a role in great vessel morphogenesis associated with patterning and/or regression of pharyngeal arch arteries. Although previous clinical reports have speculated a potential relationship between thyroid hormone homeostasis and early cardiovascular development, this is the first report to experimentally demonstrate this relationship in great vessel morphogenesis.
查看更多>>摘要：Benign prostatic hyperplasia (BPH) is an age-related disease in men. Mesenchymal /stromal and epithelial cells interactions are essential to prostate functions. In this study, human nonmalignant prostate epithelial RWPE-1 cells were cocultured with testosterone (TE) -exposed prostate stromal fibroblasts WPMY-1 cells (TE-WPMY-1). The survival rate, epithelial-mesenchymal transition (EMT) and collagen deposition of RWPE-1 were observed. The expression profiles of circRNAs, lncRNAs and mRNAs in WPMY-1-derived exosome-like vesicles (WPMY-1-exo) were explored by high-throughput RNA sequencing. Firstly, both TE-WPMY-1 and TE-WPMY-1-exo significantly promoted RWPE-1 cells proliferation. Secondly, 41 circRNAs, 132 lncRNAs and 1057 mRNAs were differentially expressed (DE) between TE-WPMY-1-exo and the control. Functional enrichment analyses, coexpression analyses and quantitative real-time PCR verification showed that the DE RNAs played important roles in cell proliferation, structure, phenotype and fibrosis. Lastly, blocking WPMY-1-exo biogenesis/release by GW4869 can attenuate TE-WPMY-1-stimulated RWPE-1 cells EMT and collagen deposition. Taken together, our results indicated that WPMY-1-exo modulated the phenotypes changes and collagen deposition of prostate epithelial cells. It provided a novel basis for understanding the underlying mechanisms of RWPE-1 cells EMT and fibrosis induced by WPMY-1 in BPH.
查看更多>>摘要：Cannabidiol (CBD) is suggested to possess cardioprotective properties. We examined the influence of chronic (10 mg/kg once daily for 2 weeks) CBD administration on heart structure (e.g. cardiomyocyte width) and function (e. g. stimulatory and inhibitory responses induced by beta-adrenoceptor (isoprenaline) and muscarinic receptor (carbachol) activation, respectively). Experiments were performed on hearts and/or left atria isolated from spontaneously (SHR) and deoxycorticosterone (DOCA-salt) hypertensive rats; Wistar-Kyoto (WKY) and shamoperated rats (SHAM) served as the respective normotensive controls. CBD diminished the width of cardiomyocytes in left ventricle and reduced the carbachol-induced vasoconstriction of coronary arteries both in DOCA-salt and SHR. However, it failed to affect left ventricular hypertrophy and even aggravated the impaired positive and negative lusitropic effects elicited by isoprenaline and carbachol, respectively. In normotensive hearts CBD led to untoward structural and functional effects, which occurred only in WKY or SHAM or, like the decrease in beta(1)-adrenoceptor density, in either control strain. In conclusion, due to its modest beneficial effect in hypertension and its adverse effects in normotensive hearts, caution should be taken when using CBD as a drug in therapy.
查看更多>>摘要：Polycystic ovarian syndrome (PCOS), is a multifactorial endocrine disorder in women of reproductive age. It usually associates with metabolic disorders (MDs), which aggravates the risk of infertility, cardiometabolic events and associated comorbidities in women with PCOS. Adiponectin, a circulating protein produced by adipocytes, which has been suggested to inversely correlate with MDs. Spironolactone, a non-selective mineralocorticoid receptor (MR) antagonist, has been in wide clinical use for several decades. Herein, we investigated the effects of low dose spironolactone (LDS) and the role of adiponectin in endocrine-metabolic disturbances in experimentally-induced PCOS rats. Eighteen female Wistar rats (160-180 g) were randomly allotted into 3 groups and treated with vehicle (p.o.), letrozole (LET; 1 mg/kg) and LET + LDS (0.25 mg/kg), once daily for 21 days, respectively. The results showed that LET-treated animals had features of PCOS, characterized by elevated plasma testosterone and prolactin, increased body weight gain and ovarian weight as well as disrupted ovarian cytoarchitecture and degenerated follicles. Additionally, elevated fasting blood glucose, 1 h-postload glucose and plasma insulin, impaired glucose tolerance, insulin resistance, reduced insulin sensitivity, increased plasma and ovarian lipid profile, plasma lipid peroxidation, TNF-alpha, IL-6 and decreased plasma glutathione peroxidase and glutathione content were observed. These alterations were associated with decreased circulating adiponectin and were reversed when treated with LDS. The present results suggest that LDS ameliorates endocrine-metabolic disturbances and inflammation-related comorbidities associated with LET-induced PCOS by modulating circulating androgen-adiponectin status.
查看更多>>摘要：Background: Inorganic arsenic (iAs) is a worldwide environmental pollutant which exerts complicated and various toxic effects in organisms. Increasingly epidemic studies have revealed the association between iAs exposure and adult male reproductive impairment. Consistent with the proposal for toxicity testing in the 21st century (TT21C), the adverse outcome pathway (AOP) framework may help unravel the iAs-caused molecular and functional changes leading to male reproductive impairment.
Scholpa, Natalie E.Simmons, Epiphani C.Crossman, Josh D.Schnellmann, Rick G....
7页
查看更多>>摘要：Mitochondrial dysfunction is a well-characterized consequence of spinal cord injury (SCI). We previously reported that treatment with the FDA-approved beta(2)-adrenergic receptor agonist formoterol beginning 8 h post-SCI induces mitochondrial biogenesis (MB) and improves body composition and locomotor recovery in female mice. To determine the time-to-treatment window of formoterol, female mice were subjected to 80 kdyn contusion SCI and daily administration of vehicle or formoterol (0.3 mg/kg) beginning 24 h after injury. This delayed treatment paradigm improved body composition in female mice by 21 DPI, returning body weight to pre-surgery weight and restoring gastrocnemius mass to sham levels; however, there was no effect on locomotor recovery, as measured by the Basso-Mouse Scale (BMS), or lesion volume. To assess the cross-sex potential of formoterol, injured male mice were treated with vehicle or formoterol (0.3 or 1.0 mg/kg) beginning 8 h after SCI. Formoterol also improved body composition post-SCI in male mice, restoring body weight and muscle mass regardless of dose. Interestingly, however, improved BMS scores and decreased lesion volume was observed only in male mice treated with 0.3 mg/kg. Additionally, 0.3 mg/kg formoterol induced MB in the gastrocnemius and injured spinal cord, as evidenced by increased MB protein expression and mitochondrial number. These data indicate that formoterol treatment improves recovery post-SCI in both male and female mice in a dose- and initiation time-dependent manner. Furthermore, formoterol-induced functional recovery post-SCI is not directly associated with peripheral effects, such as muscle mass and body weight.
查看更多>>摘要：This study aims to investigate whether Escin (ES) can protect against Cyclophosphamide (CPM)-induced cardiac damage. The experimental rats were categorized as Control, CPM (200 mg/kg), ES (10 mg/kg), and CPM + ES Groups, each having 6 members. Their heart tissues were stained with Hematoxylin and Eosin and the structural changes were investigated under the light microscope. The biochemical markers of ischemia modified albumin (IMA), creatine kinase (CK-MB), antioxidant activity indicators Catalase (CAT), and superoxide dismutase (SOD) activities were measured using blood samples. Besides, the effects of CPM, ES, and CPM + ES upon CAT and SOD activities were shown via molecular docking studies. In the Single-Dose CPM group, CK-MB and IMA levels significantly increased while SOD and CAT levels significantly decreased. However, the heart tissues were damaged. CK-MB and IMA levels significantly decreased in CP+ ES Group. On the other hand, SOD, and CAT levels significantly increased and reduced the damage remarkably. Our findings showed that ES treatment successfully reduced the toxic effects upon the rats. The conclusion is that ES treatment can help protect the heart tissue against CPM-induced toxicity. Both in-vivo results and molecular modeling studies showed that the negative effects of CPM upon SOD activity were bigger than that of CAT.
查看更多>>摘要：Due to structural similarity to bisphenol A and lack of safety data, the National Toxicology Program (NTP) is evaluating the potential toxicity of bisphenol AF (BPAF) in rodent models. The current investigation reports the internal exposure data for free (unconjugated BPAF) and total (free and conjugated forms) BPAF during critical stages of development following perinatal dietary exposure in Hsd:Sprague Dawley (R) SD (R) rats to 0 (vehicle control), 338, 1125, and 3750 ppm BPAF from gestation day (GD) 6 to postnatal day (PND) 28. Free and total BPAF concentrations in maternal plasma at GD 18, PND 4, and PND 28 increased with the exposure concentration; free BPAF concentrations were <= 1.61% those of total BPAF demonstrating extensive first pass metabolism of BPAF following dietary exposure in adults. Free and total BPAF were quantified in GD 18 fetuses and PND 4 pups with free concentrations 11.7-53.4% that of corresponding total concentrations. In addition, free concentrations were higher (130-571%) and total concentrations were lower (1.71-7.23%) than corresponding concentrations in dams, demonstrating either preferential transfer of free BPAF and/or inability of fetuses and pups to conjugate BPAF. Free and total concentrations in PND 28 pups were similar to maternal concentrations demonstrating direct exposure of pups via feed and that conjugating enzymes are developed in PND 28 pups. In conclusion, these data demonstrate considerable gestational and lactational transfer of parent aglycone from the mother to offspring. Since the ontogeny of conjugating enzymes in humans is similar to that of rodents, the data from rodent BPAF studies may be useful in predicting human risk from exposure to BPAF.
查看更多>>摘要：Arsenic exposure is well established to impair the function of zinc finger proteins, including PARP-1. Previous studies from our lab show that early developing T cells in the thymus are very sensitive to arsenite (As+3)-induced genotoxicity mediated through PARP-1 inhibition. Additionally, it has been shown that uranium (in the form of uranyl acetate, UA) also suppresses PARP-1 activity in HEK cells. However, very little is known about whether the As+3 metabolite, monomethylarsonous acid (MMA(+3)), also inhibits PARP-1 activity and if this is modified by combined exposures with other metals, such as uranium. In the present study, we found that MMA(+3) significantly suppressed PARP-1 function, whereas UA at high concentrations significantly increased PARP-1 activity. To evaluate whether the effects on PARP-1 activity were mediated through oxidative stress, we measured the induction of hemoxygenase-1 (Hmox-1) expression by qPCR. MMA(+3), but not UA, significantly induced oxidative stress; however, the inhibition of PARP-1 produced by MMA(+3) was not reversed by the addition of the antioxidant, Tempol. Further evaluation revealed minimal interactive effects of MMA(+3) and UA on PARP-1 function. Collectively, our results show that contrary to As+3, the suppressive effects of MMA(+3) on PARP-1 were not substantially driven by oxidative stress' in mouse thymus cells. Results for this study provide important insights into the effects of MMA(+3) and uranium exposures on PARP-1 function, which is essential for future studies focused on understanding the effects of complex environmentally relevant metal mixtures.
NSTL
Elsevier