RESUMO
Bisphenols such as bisphenol A (BPA), S (BPS), C (BPC), F (BPF), AF (BPAF), tetrabromobisphenol, nonylphenol, and octylphenol are plasticizers used worldwide to manufacture daily-use articles. Exposure to these compounds is related to many pathologies of public health importance, such as infertility. Using a protector compound against the reproductive toxicological effects of bisphenols is of scientific interest. Melatonin and vitamins have been tested, but the results are not conclusive. To this end, this systematic review and meta-analysis compared the response of reproductive variables to melatonin and vitamin administration as protectors against damage caused by bisphenols. We search for controlled studies of male rats exposed to bisphenols to induce alterations in reproduction, with at least one intervention group receiving melatonin or vitamins (B, C, or E). Also, molecular docking simulations were performed between the androgen (AR) and estrogen receptors (ER), melatonin, and vitamins. About 1234 records were initially found; finally, 13 studies were qualified for review and meta-analysis. Melatonin plus bisphenol improves sperm concentration and viability of sperm and increases testosterone serum levels compared with control groups; however, groups receiving vitamins plus bisphenols had lower sperm concentration, total testis weight, and testosterone serum levels than the control. In the docking analysis, vitamin E had the highest negative MolDock score, representing the best binding affinity with AR and ER, compared with other vitamins and melatonin in the docking. Our findings suggest that vitamins could act as an endocrine disruptor, and melatonin is most effective in protecting against the toxic effects of bisphenols.
Assuntos
Disruptores Endócrinos , Melatonina , Masculino , Ratos , Animais , Melatonina/farmacologia , Vitaminas , Simulação de Acoplamento Molecular , Sêmen/metabolismo , Compostos Benzidrílicos/toxicidade , Compostos Benzidrílicos/química , Reprodução , Receptores de Estrogênio , Vitamina A , Vitamina K , Testosterona/metabolismo , Disruptores Endócrinos/toxicidade , Disruptores Endócrinos/químicaRESUMO
This study investigated whether the coadministration of vitamin E (VitE) diminishes the harmful effects provoked by plasticizer bisphenol S (BPS) in the serum metabolites related to hepatic and renal metabolism, as well as the endocrine pancreatic function in diabetic male Wistar rats. Rats were divided into five groups (n = 5-6); the first group was healthy rats (Ctrl group). The other four groups were diabetic rats induced with 45 mg/kg bw of streptozotocin: Ctrl-D (diabetic control); VitE-D (100 mg/kg bw/d of VitE); BPS-D (100 mg/kg bw/d of BPS); The animals from the VitE + BPS-D group were administered 100 mg/kg bw/d of VitE + 100 mg/kg bw/d of BPS. All compounds were administered orally for 30 days. Body weight, biochemical assays, urinalysis, glucose tolerance test, pancreas histopathology, proximate chemical analysis in feces, and the activity of antioxidants in rat serum were assessed. The coadministration of VitE + BPS produced weight losses, increases in 14 serum analytes, and degeneration in the pancreas. Therefore, the VitE + BPS coadministration did not have a protective effect versus the harmful impact of BPS or the diabetic metabolic state; on the contrary, it partially aggravated the damage produced by the BPS. VitE is likely to have an additive effect on the toxicity of BPS.
RESUMO
Daily, people are exposed to chemicals and environmental compounds such as bisphenols (BPs). These substances are present in more than 80% of human fluids. Human exposure to BPs is associated with male reproductive health disorders. Some of the main targets of BPs are intercellular junction proteins of the blood-testis barrier (BTB) in Sertoli cells because BPs alter the expression or induce aberrant localization of these proteins. In this systematic review, we explore the effects of BP exposure on the expression of BTB junction proteins and the characteristics of in vivo studies to identify potential gaps and priorities for future research. To this end, we conducted a systematic review of articles. Thirteen studies met our inclusion criteria. In most studies, animals treated with bisphenol-A (BPA) showed decreased occludin expression at all tested doses. However, bisphenol-AF treatment did not alter occludin expression. Cx43, ZO-1, ß-catenin, nectin-3, cortactin, paladin, and claudin-11 expression also decreased in some tested doses of BP, while N-cadherin and FAK expression increased. BP treatment did not alter the expression of α and γ catenin, E-cadherin, JAM-A, and Arp 3. However, the expression of all these proteins was altered when BPA was administered to neonatal rodents in microgram doses. The results show significant heterogeneity between studies. Thus, it is necessary to perform more research to characterize the changes in BTB protein expression induced by BPs in animals to highlight future research directions that can inform the evaluation of risk of toxicity in humans.
Assuntos
Barreira Hematotesticular , Células de Sertoli , Animais , Recém-Nascido , Masculino , Humanos , Barreira Hematotesticular/metabolismo , Ocludina/metabolismo , Ocludina/farmacologia , Células de Sertoli/metabolismo , Junções IntercelularesRESUMO
Bisphenol S (BPS) has been introduced into the industry as a safer alternative to bisphenol A (BPA). However, the recent studies have reported a possible association between BPS and disturbed glucose homeostasis, indicating that it may be a risk factor for type 1 and type 2 diabetes mellitus, obesity, and gestational diabetes mellitus. Nevertheless, the role of BPS in glucose metabolism remains controversial. In this study, we investigated the glucose metabolism of male Wistar rats born from dams that were BPS-exposed (groups: BPS-L (0.05 mg/kg/day), BPS-H (20 mg/kg/day)) during pregnancy and lactation. We observed that both BPS treated groups of animals presented a significant decrease in anogenital distance/weight1/3 , as compared to control animals, although no alterations in testosterone levels were observed. Furthermore, the BPS-L group presented a significant decrease in body weight from postnatal day (PND) 21 to adult stage. In addition, a significant increase in glucose tolerance, pancreatic ß-cell proliferation, the frequency of small islets, and the average ß-cell size at PND 36 was observed in this group. However, no changes in insulin serum levels and percentage of ß-cells were recorded. Furthermore, these changes were not preserved at the adult stage (PND 120). The results suggest that the administration of low doses of BPS during the perinatal period induced an estrogenic like effect, with males apparently becoming more female-like in their responses to a glucose challenge.
Assuntos
Diabetes Mellitus Tipo 2 , Efeitos Tardios da Exposição Pré-Natal , Animais , Compostos Benzidrílicos/toxicidade , Feminino , Glucose/metabolismo , Homeostase , Humanos , Masculino , Exposição Materna/efeitos adversos , Gravidez , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Ratos , Ratos WistarRESUMO
Bisphenols are a group of environmental endocrine-disrupting chemicals that produce alterations in the expression of intercellular junction proteins of the Blood-Testis Barrier (BTB) involved in spermatogenesis. The association between bisphenol exposure and BTB protein expression is controversial. Therefore, we performed this systematic review and meta-analysis to clarify bisphenol effects on Sertoli cell BTB protein expression in vitro. The Standardized Mean Difference (SMD) with a 95 % confidence interval (95 % CI) was used to evaluate the association between alterations in the BTB protein expression and bisphenol exposure in vitro. Six articles were included in the meta-analysis. Bisphenol-A (BPA) exposure at 200⯵M was associated with significant decrease in BTB protein expression (SMDâ¯=â¯-2.70, 95 %CI: -3.59, -1.80, p hetâ¯=â¯0.46, pâ¯=â¯<0.00001). In the moderate (40-50⯵M) and low dose (<25⯵M), no significant associations were obtained. We also found a non-monotonic dose-response curve of bisphenol effect in ZO-1 protein expression; low and high doses presented a significant decrease compared to control, while moderate dose presented no change. The current temporary Tolerable Daily Intake (tTDI) of BPA is 4⯵g/kg bw/day. The 5-25⯵M doses of BPA are equivalent to â¼1-5â¯mg/kg bw, respectively. Although the low dose group (<25⯵M) assessed doses below the previous NOAEL value, these doses are above the current tTDI. Thus, it is necessary to conduct more studies with lower bisphenol concentrations to avoid underestimating the potential adverse effects of bisphenols at doses below tTDI.
Assuntos
Compostos Benzidrílicos/toxicidade , Barreira Hematotesticular/efeitos dos fármacos , Fenóis/toxicidade , Disruptores Endócrinos/metabolismo , Disruptores Endócrinos/toxicidade , Humanos , Junções Intercelulares/efeitos dos fármacos , Masculino , Ocludina/metabolismo , Proteínas/metabolismo , Células de Sertoli/efeitos dos fármacos , Espermatogênese , Testículo/efeitos dos fármacos , Proteína da Zônula de Oclusão-1/metabolismoRESUMO
The aim was to evaluate the effect of perinatal BPA exposure of one or both parents on the implantation index and expression of talin, occludin and E-cadherin in the uterine epithelial cells (UEC) of the offspring. Pregnant Wistar dams (F0) received BPA or vehicle from gestational day (GD) 6 to lactation day 21. F1 animals were mated forming four groups: Control dam-Control sire (Câ-Câ), BPA dam -Control sire (Bâ-Câ), Control dam -BPA sire (Câ-Bâ), BPA dam -BPA sire (Bâ-Bâ). F1 dams were sacrificed at GD 6. Significantly decreased number of implantation sites was observed in the Bâ-Bâ group as compared to the Câ-Câ group, which correlated with decreased talin apical/basal expression ratio, occludin apical expression, and E-cadherin apical/lateral expression ratio in the UEC. Furthermore, decreased E-cadherin expression in the blastocyst was observed. Our data suggest that reduced protein expressions in F1 BPA offspring could result from decreased progesterone serum levels.
Assuntos
Compostos Benzidrílicos/toxicidade , Caderinas/metabolismo , Implantação do Embrião/efeitos dos fármacos , Troca Materno-Fetal , Ocludina/metabolismo , Fenóis/toxicidade , Talina/metabolismo , Animais , Estradiol/sangue , Feminino , Masculino , Gravidez , Progesterona/sangue , Ratos Wistar , Útero/efeitos dos fármacos , Útero/metabolismoRESUMO
We studied the effect of bisphenol-A (BPA) administration to rats, during the perinatal period, on the fertility of F1 generation and on the expression of tight junction (TJ) proteins in the uterus during early pregnancy. Pregnant Wistar dams (F0) received: BPA-L (0.05mg/kg/day), BPA-H (20mg/kg/day) or vehicle, from gestational day (GD) 6 to lactation day 21. F1 female pups were mated at 3 months of age and sacrificed at GD 1, 3, 6, and 7. Serum hormonal levels, ovulation rate, number of implantation sites and expression of TJ proteins in the uterus of F1 females were evaluated. BPA treatment induced no change in ovulation rate, but induced alterations in progesterone (P4) and estradiol (E2) serum levels, and in implantation rate. With regards to TJ proteins, BPA-H increased claudin-1 during all GDs; eliminated the peaks of claudins -3 and -4 at GD 3 and 6, respectively; and decreased claudin-7 at GD 6, ZO-1 from GD 1-6, and claudin-3 at GD 7 in stromal cells. BPA-L instead, eliminated claudin-3 peak at GD 3, increased claudin-4 and decreased claudin-7 from GD 1-6, decreased claudin-1 at GD 3 and 7 and claudin-4 at GD 7 in stromal cells. BPA-L also decreased ZO-1 at GDs 1 and 3 and increased ZO-1 at GD 6. Thus, BPA treatment during perinatal period perturbed, when the animals reached adulthood and became pregnant, the particular expression of TJ proteins in the uterine epithelium and reduced in consequence the number of implantation sites.
Assuntos
Compostos Benzidrílicos/toxicidade , Disruptores Endócrinos/toxicidade , Fenóis/toxicidade , Proteínas de Junções Íntimas/metabolismo , Útero/efeitos dos fármacos , Animais , Implantação do Embrião/efeitos dos fármacos , Estradiol/sangue , Feminino , Lactação , Masculino , Gravidez , Progesterona/sangue , Ratos Wistar , Útero/metabolismoRESUMO
The mechanism of reproduction in mammals is very complex and in some cases is quite particular. For example in some bat species, the male presents a reproductive mechanism characterized by an annual testicular cycle that goes from recrudescence to regression (spermatogenesis to inactivity period, respectively). After recrudescence, the spermatozoa arrive at epididymis and wait to be expelled at the time of ejaculation during the mating period, which occurs some months later. Because serotonin (5-HT) has gained reproductive importance in the last years, the aim of the present study was to analyze the expression of this indolamine and both tryptophan hydroxylase and monoamine oxidase isoform A-enzymes involved in its metabolism-in Myotis velifer testes, a seasonal reproductive bat species that shows temporal asynchrony in its sexual cycle, across the principal periods of their reproductive cycle. By using both Falck-Hillarp histochemistry and immunofluorescence techniques, we found serotonin in vesicles of Leydig cells and probably Sertoli cells too; interestingly, both intracellular localization and concentration was variable across the different stages of the reproductive cycle, being lower during spermatogenesis phase and increasing during the mating phase. These results suggest that 5-HT is present in bat testes and it could play an important role in testicular function during their reproductive cycle.
Assuntos
Serotonina/biossíntese , Espermatogênese , Espermatozoides/crescimento & desenvolvimento , Testículo/crescimento & desenvolvimento , Animais , Epididimo/metabolismo , Células Intersticiais do Testículo/metabolismo , Masculino , Mamíferos/crescimento & desenvolvimento , Mamíferos/metabolismo , Monoaminoxidase/metabolismo , Reprodução , Estações do Ano , Células de Sertoli/metabolismo , Testículo/enzimologia , Testículo/metabolismo , Triptofano Hidroxilase/metabolismoRESUMO
We examined the ability of ICI 182,780 (ICI) to block uterine cell proliferation via protein kinase b/AKT pathway in the uterus of the rat during the estrous cycle. Intact rats, with regular estrous cycles, received a subcutaneous (s.c.) injection of either vehicle or ICI at 08:00 h on the day of proestrus or at 00:00 h on the day of estrus and sacrificed at 13:00 h of metaestrus. Estradiol (E2) and progesterone (P4) plasma levels were measured by radioimmunoassay. Both ICI treatments, induced a significant decrease (p<0.01) in uterine estrogen receptor alpha (ERα) content, had no effect on uterine progesterone receptor (PR) protein expression and caused marked nuclear localization of cyclin D1, in both luminal and glandular uterine epithelium, as compared to vehicle-treated animals. Furthermore, we detected that ICI treatment induced glycogen synthase kinase (Gsk3-ß) Ser 9 phosphorylation, which correlates with cyclin D1 nuclear localization. However, some differences were observed between the two different time schedules of administration. We observed that the administration of ICI at 08:00 h on proestrus day produced a 15% inhibition of luminal epithelial cell proliferation, reduced uterine wet weight by 21% and caused reduction of Akt phosphorylation at Ser 473 as compared to vehicle-treated animals, whereas ICI treatment at 00:00 h on estrus day had no effect on these parameters. The overall results indicate that ICI may exert agonistic and antagonistic effects on uterine cell proliferation through differential activation of the Akt pathway depending on the administration period during the estrous cycle, and indicates that the mechanism of cell proliferation during the physiological conditions of the estrous cycle, is under a different and more complex regulation than in the ovariectomized + E2 animal model.
Assuntos
Estradiol/análogos & derivados , Ciclo Estral/efeitos dos fármacos , Ciclo Estral/metabolismo , Quinase 3 da Glicogênio Sintase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Útero/metabolismo , Animais , Western Blotting , Proliferação de Células/efeitos dos fármacos , Estradiol/farmacologia , Feminino , Fulvestranto , Quinase 3 da Glicogênio Sintase/genética , Glicogênio Sintase Quinase 3 beta , Imuno-Histoquímica , Proteínas Proto-Oncogênicas c-akt/genética , Radioimunoensaio , Ratos , Útero/efeitos dos fármacosRESUMO
BACKGROUND: D3CLP (9-[(3-chloro)phenylamine]-2-[3-(diethylamine)propylamine]thiazolo[5,4-b]quinoline) is a potent cytotoxic thiazolo[5,4-b]quinoline synthetic derivative that induces apoptosis of leukemia cells, while it displays low toxicity towards non-tumoral cells. The aim of this study was to determine if D3CLP can enhance the cytotoxicity of other antineoplastic drugs. MATERIALS AND METHODS: Leukemia, breast and cervical cancer cell lines were exposed to D3CLP-alone or in combination with imatinib, tamoxifen or cisplatin, respectively. Cell viability after treatment was evaluated by the MTT assay, and cell death by the TUNEL assay. The effects of combined treatments were analyzed by combination index and isobolographic analysis. RESULTS: Antiproliferative activity results indicate that D3CLP in combination with antineoplastic drugs induced a synergistic effect, at 3:1 and 1:1 ratios for D3CLP plus imatinib in K-562 leukemia cells, and at a 3:1 ratio for D3CLP with cisplatin in HeLa cells, as determined by their combination index. Furthermore, isobolographic analysis demonstrated a significant synergism for a 3:1 combination ratio of D3CLP with cisplatin in HeLa cells. In addition, TUNEL assay suggests cell death by apoptosis of HeLa cells after treatment with D3CLP and its combination with cisplatin at a 3:1 ratio. CONCLUSION: Overall the results indicate that D3CLP, in combined preparation with antineoplastic drugs, is a good candidate for pre-clinical studies in the treatment of different carcinoma cell types.
Assuntos
Aminoquinolinas/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Cisplatino/farmacologia , Tiazóis/farmacologia , Neoplasias do Colo do Útero/tratamento farmacológico , Aminoquinolinas/administração & dosagem , Benzamidas , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/administração & dosagem , Fragmentação do DNA/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Sinergismo Farmacológico , Feminino , Células HeLa , Humanos , Mesilato de Imatinib , Células K562 , Células MCF-7 , Piperazinas/administração & dosagem , Piperazinas/farmacologia , Pirimidinas/administração & dosagem , Pirimidinas/farmacologia , Tamoxifeno/administração & dosagem , Tamoxifeno/farmacologia , Tiazóis/administração & dosagem , Neoplasias do Colo do Útero/patologiaRESUMO
Serotonin (5-hydroxytryptamine; C(10)H(12)N(2)O (5-HT)) is produced in the CNS and in some cells of peripheral tissues. In the mammalian male reproductive system, both 5-HT and tryptophan hydroxylase (TPH) have been described in Leydig cells of the testis and in principal cells of the caput epididymis. In capacitated hamster sperm, it has been shown that 5-HT promotes the acrosomal reaction. The aim of this work was to explore the existence of components of the serotoninergic system and their relevance in human sperm physiology. We used both immunocytochemistry and western blot to detect serotoninergic markers such as 5-HT, TPH1, MAO(A), 5-HT(1B), 5-HT(3), and 5HT(T); HPLC for TPH enzymatic activity; Computer Assisted Semen Analysis assays to measure sperm motility parameters and pharmacological approaches to show the effect of 5-HT in sperm motility and tyrosine phosphorylation was assessed by western blot. We found the presence of serotoninergic markers (5-HT, TPH1, MAO(A), 5-HT(1B), 5-HT(2A), 5-HT(3), 5-HT(T), and TPH enzymatic activity) in human sperm. In addition, we observed a significant increase in tyrosine phosphorylation and changes in sperm motility after 5-HT treatment. In conclusion, our data demonstrate the existence of components of a serotoninergic system in human sperm and support the notion for a functional role of 5-HT in mammalian sperm physiology, which can be modulated pharmacologically.
Assuntos
Proteínas Tirosina Quinases/metabolismo , Receptores de Serotonina/metabolismo , Serotonina/metabolismo , Espermatozoides/metabolismo , Biomarcadores/metabolismo , Humanos , Masculino , Fosforilação , Motilidade dos EspermatozoidesRESUMO
Post-burn hypertrophic scars are characterized by increased collagen synthesis and hyperplasia, and may be associated with erythema, pain, dysesthesia, pruritus, and skin border elevation. Although the etiopathogenesis of hypertrophic scarring remains unclear, proinflammatory and profibrogenic cytokines are known to play an important role in general skin dysfunction. This study assessed mRNA expression, proteins, and type I receptors of tumor necrosis factor-alpha (TNF-α) and interleukin 1-beta (IL-1ß) in normal skin, normotrophic and post-burn hypertrophic scars. Skin biopsies were obtained from 10 hypertrophic and 9 normotrophic scars, and 4 normal skin sites. Only post-burn scars covering more than 10% of the body were included. Ex vivo histopathological analysis evaluated scar maturity, in situ hybridization assessed mRNA expression, and cytokine protein and cytokine/cell colocalization were performed using single- and double-label immunohistochemistry, respectively. IL-1ß is overexpressed in hypertrophic scars at the post-transcriptional level, associated primarily with keratinocytes and CD1a(+) cells. Type I receptors for TNF-α are overexpressed in blood vessels of hypertrophic scars. The coordinated overexpression of IL-1ß and TNF-α type I receptor may maintain the fibrogenic phenotypes of hypertrophic scars, even those in "remission".
Assuntos
Queimaduras/complicações , Cicatriz Hipertrófica/metabolismo , Interleucina-1beta/metabolismo , RNA Mensageiro/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Análise de Variância , Cicatriz Hipertrófica/etiologia , Humanos , Imuno-Histoquímica , Hibridização In Situ , Interleucina-1beta/genéticaRESUMO
BACKGROUND: Although the etiology of preeclampsia is still unclear, recent work suggests that changes in circulating angiogenic factors play a key role in its pathogenesis. In the trophoblast of women with preeclampsia, hypoxia-inducible factor 1 alpha (HIF-1α) is over-expressed, and induces the expression of non-angiogenic factors and inhibitors of trophoblast differentiation. This observation prompted the study of HIF-1α and its relation to preeclampsia. It has been described that the C1772T (P582S) and G1790A (A588T) polymorphisms of the HIF1A gene have significantly greater transcriptional activity, correlated with an increased expression of their proteins, than the wild-type sequence. In this work, we studied whether either or both HIF1A variants contribute to preeclampsia susceptibility. RESULTS: Genomic DNA was isolated from 150 preeclamptic and 105 healthy pregnant women. Exon 12 of the HIF1A gene was amplified by PCR, and the genotypes of HIF1A were determined by DNA sequencing.In preeclamptic women and controls, the frequencies of the T allele for C1772T were 4.3 vs. 4.8%, and the frequencies of the A allele for G1790A were 0.0 vs. 0.5%, respectively. No significant differences were found between groups. CONCLUSION: The frequency of the C1772T and G1790A polymorphisms of the HIF1A gene is very low, and neither polymorphism is associated with the development of preeclampsia in the Mexican population.
RESUMO
Bisphenol A (BPA) is an estrogenic agonist compound that induces changes in diverse reproductive parameters in rats. The aim of the present study was to determine the effects of BPA given in drinking water containing 10mg/L (approximate dose 1.2mg/kg BW/day), administered chronically to rats during pregnancy and lactation, on reproductive tract parameters of the offspring. 79.2% of the female offspring from BPA-treated mothers presented irregular estrous cycles. As compared to the control group, a significant increase in the thickness of the uterine epithelia and stroma was observed in the BPA group. Additionally, 60% of the female offspring from BPA mothers did not undergo abundant uterine epithelial apoptosis during the estrus phase of the cycle while control animals did. In addition, a down regulation of ERα expression was observed in epithelial cells on estrus day. The results indicate that BPA, when administered chronically in water beverages to dams, modifies the reproductive cycle of the offspring during young adulthood.
Assuntos
Estrogênios não Esteroides/toxicidade , Fenóis/toxicidade , Efeitos Tardios da Exposição Pré-Natal , Reprodução/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Compostos Benzidrílicos , Epitélio/anatomia & histologia , Epitélio/química , Epitélio/efeitos dos fármacos , Receptor alfa de Estrogênio/análise , Estrogênios não Esteroides/administração & dosagem , Ciclo Estral/efeitos dos fármacos , Feminino , Lactação , Fenóis/administração & dosagem , Gravidez , Ratos , Ratos Wistar , Reprodução/fisiologia , Útero/anatomia & histologia , Útero/química , Útero/efeitos dos fármacos , ÁguaRESUMO
We characterized the expression pattern of estrogen receptor alpha (ERalpha) gene in two regions of the oviduct, ampullae and isthmus, of the rabbit (Oryctolagus cuniculus) during early pregnancy (1-4 days) by RT-PCR and immunohistochemistry. In both regions of the oviduct, ERalpha mRNA was increased (P<0.01) in pregnant rabbits as compared with non-pregnant animals (NG). In the ampullae, the greatest amount of ERalpha mRNA was detected on the third day of pregnancy (1.01+/-0.02 relative amount), followed by a decrease on Day 4. In the isthmus, an increase in ERalpha mRNA was observed during the first 4 days of pregnancy, with the greatest amount on Day 3 (1.49+/-0.3 relative amount). A marked ERalpha immunostaining was detected in epithelial, stromal and smooth muscle cells of the ampullae on the second and third days of pregnancy as compared with the NG group. In contrast, a significant increase in ERalpha immunostaining was observed on the first and second days of pregnancy with a reduction on the third and fourth days in the epithelial, stromal and smooth muscle cells of the isthmus. The overall results suggest there is differential expression pattern for the ERalpha gene in the ampullae and isthmus during early pregnancy of the rabbit, and that these variations are related to specific functions of ERalpha in the reproductive tract during early pregnancy.
Assuntos
Receptor alfa de Estrogênio/genética , Tubas Uterinas/metabolismo , Expressão Gênica , Coelhos/metabolismo , Animais , Tubas Uterinas/anatomia & histologia , Feminino , Idade Gestacional , Imuno-Histoquímica , Gravidez , RNA Mensageiro , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Progesterone receptor (PR) plays an important role in mammals pregnancy which is characterized by greater progesterone plasma concentrations. We assessed PR protein distribution in the rabbit uterus by immunohistochemistry in two progestational conditions: pseudopregnancy (intact adult animals treated with hCG) and after application of a synthetic progestin, medroxyprogesterone acetate (MPA), to ovariectomized animals (OVX). PR immunoreactivity in uterine epithelium of pseudopregnant rabbits was increased in relation to non-pseudopregnant (NP) rabbits. Amounts were similar on Days 1, 3, and 5 of treatment, and was greater on Day 7 (P<0.001). In contrast, a significant diminution in PR immunoreactivity was observed in stroma cells from Days 1 to 7 (P<0.001). In OVX rabbits treated with MPA, an increase in PR immunoreactivity was observed in the uterine epithelium on Days 1 to 5 of treatment, reaching a maximum on Day 3 (P<0.001). In contrast, in stromal cells a diminution in PR immunoreactivity was observed when compared to the OVX group on Days 1, 3 and 7 of MPA treatment (P<0.001), and there was a slight increase on Day 5. Results suggest a differential time course and tissue specific immunoreactivity for PR in the uterus of the rabbit in two progestational conditions. The present study indicated synthetic progestins have different mechanisms of receptor regulation than those of natural hormones and it should be taken into account in reproductive applications.
Assuntos
Acetato de Medroxiprogesterona/farmacologia , Pseudogravidez/metabolismo , Receptores de Progesterona/metabolismo , Útero/efeitos dos fármacos , Útero/metabolismo , Animais , Gonadotropina Coriônica/farmacologia , Anticoncepcionais/farmacologia , Avaliação Pré-Clínica de Medicamentos , Feminino , Imuno-Histoquímica , Ovariectomia , Progesterona/sangue , Pseudogravidez/sangue , Pseudogravidez/patologia , Coelhos , Fatores de Tempo , Útero/patologiaRESUMO
Recent evidence suggests that hormonal effects on mitochondria could be mediated by mitochondrial estrogen receptors (mtERs). These receptors are new candidates for the beneficial estrogenic effects on mitochondria in different physiological conditions. The aim of this investigation was to study mtER expression during brain aging. We analyzed mtERalpha and mtERbeta expression in cortical, hippocampal and hypothalamic mitochondria of young adult (3months) and aged (18 months) female Wistar rats by Western blot. In addition, we explored the interaction of mtERbeta with respiratory complex V by using coimmunoprecipitation assays. The results show that mtERalpha and mtERbeta are present in young and aged brain mitochondria. We also demonstrate that mtERs are expressed as variants and have a brain region specific distribution. The predominant mtER variants detected were of 61 and 55KDa for mtERalpha and of 63 and 52KDa for mtERbeta. However, we did not observe differences in the mtERalpha or beta content between the two age groups studied. Additionally, we show that mtERbeta interacts with complex V. The overall results demonstrate that there is a differential expression of mtERalpha and mtERbeta variants in different brain areas, indicating that they may participate in different functions in the brain during aging.
Assuntos
Envelhecimento/metabolismo , Encéfalo/metabolismo , Complexo de Proteínas da Cadeia de Transporte de Elétrons/metabolismo , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/metabolismo , Mitocôndrias/metabolismo , Envelhecimento/genética , Animais , Córtex Cerebral/metabolismo , Receptor alfa de Estrogênio/genética , Receptor beta de Estrogênio/genética , Feminino , Variação Genética , Hipocampo/metabolismo , Hipotálamo/metabolismo , Ratos , Ratos Wistar , Distribuição TecidualRESUMO
Estrogen receptor (ER)-mediated neuroprotection has been demonstrated in both in vitro and in vivo model systems. Two types of estrogen receptors, ERalpha and ERbeta, are the major mediators of the biological functions of estrogens. In the hippocampus, ERbeta is prevalent over ERalpha. Recently, we reported that during the final phase of lactation there is a neuroprotective mechanism in the hippocampus of the adult female rat against neuronal damage induced by systemic kainic acid administration vs. virgin (metestrus) rats. In this study, we assessed differential ER expression and localization in CA1, CA3 and dentate gyrus regions of dorsal hippocampus of metestrus and lactating adult rats at day 19 of lactation, during basal conditions (metestrus and L19, respectively) and 24h after systemic kainate administration. ERs were assessed by western blot and immunohistochemistry. We found a significant increase in the expression of ERs in the hippocampus during lactation as compared with metestrus. ERbeta was significantly increased in the CA1 and CA3 of lactating rats after the kainic acid insult. In addition, we observed a relocalization of ERbeta from the cytoplasm to the nucleus of neuronal cells. Our results suggest that there is a strong correlation between expression of ERs, especially ERbeta, in lactating CA1 and CA3 hippocampus regions in response to kainate administration, and neuroprotection observed during this reproductive period. This may be one of the mechanisms involved in the protection of the maternal brain to ensure offspring survival.
Assuntos
Hipocampo/metabolismo , Lactação/metabolismo , Neurônios/metabolismo , Receptores de Estrogênio/metabolismo , Animais , Animais Lactentes , Citoproteção , Receptor alfa de Estrogênio/análise , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/análise , Receptor beta de Estrogênio/metabolismo , Feminino , Hipocampo/efeitos dos fármacos , Ácido Caínico/toxicidade , Neurônios/efeitos dos fármacos , Ratos , Ratos WistarRESUMO
The rodent uterus is a widely studied target tissue for sexual steroid hormone action. The aim of the present study was to assess the molecular mechanism that participates in the initiation of cell proliferation of the rat uterine epithelial cells during the estrus (E)-metestrus (M) transition. Cell proliferation, ERalpha, c-fos, cyclin D1 and D3, cdk4, and cdk6 proteins were assessed in these animals by immunohistochemistry. Estradiol (E(2)) and progesterone (P(4)) plasma levels were assessed by RIA. The results indicate that the glandular epithelium starts to proliferate at 21:00 h on estrus day, and initiates at least 3h before the luminal epithelium does. Fos expression was markedly increased during the afternoon of estrus day, and its increase was in parallel to ERalpha expression. Interestingly, both, cyclin D1 and D3 were abundantly expressed in the luminal and glandular epithelia, and nuclear immunolabelling of cyclin D1 and D3 precedes BrdU incorporation in the cell. cdk4 and cdk6 were localized in the nuclei in both epithelia throughout the studied time course. In addition, cdk4 was more abundant throughout estrus and metestrus days than cdk6. The overall results indicate that ERalpha, Fos and cyclins D1 and D3, cdk4 and cdk6 are expressed in both glandular and luminal epithelia of the rat uterus during the E-M transition. In conclusion, there is a good correlation between sequential expression of these proteins and cell cycle progression in the rat uterine epithelial cells during the estrous cycle. However, the differences observed in the cellular localization, time course of expression and the cellular types that express both cyclins between physiological and pharmacological conditions, demonstrated different mechanisms of regulation and should be due to the complex hormonal milieu during the estrous cycle.
Assuntos
Proliferação de Células , Células Epiteliais/fisiologia , Ciclo Estral/fisiologia , Útero/citologia , Animais , Ciclo Celular/fisiologia , Ciclina D1/genética , Ciclina D1/metabolismo , Ciclina D3 , Quinase 4 Dependente de Ciclina/genética , Quinase 4 Dependente de Ciclina/metabolismo , Quinase 6 Dependente de Ciclina/genética , Quinase 6 Dependente de Ciclina/metabolismo , Ciclinas/genética , Ciclinas/metabolismo , Células Epiteliais/citologia , Estradiol/sangue , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Feminino , Proteínas Oncogênicas v-fos/genética , Proteínas Oncogênicas v-fos/metabolismo , Progesterona/sangue , Ratos , Ratos Wistar , Útero/fisiologiaRESUMO
Estrous cycle in mammals includes marked epithelial changes in reproductive tract, regulated by sex steroid hormones. In the present work we studied the activation of caspases and apoptotic pattern in uterine epithelial cells during proestrus and estrus, and the effect of mating in this process. In addition, we investigated the role of seminal vesicle secretions on apoptosis of uterine epithelia. Apoptotic index was evaluated by TUNEL assay, caspases-8, -9, and -3 activation was detected by Western blot and active caspase-3 expression was detected by immunohistochemistry. Our results show that mating during proestrus and estrus transition induced changes in the apoptotic pattern of uterine luminal epithelium during estrus, characterized by a delay in the onset of apoptosis as compared with that observed in nonmated rats. No differences in the apoptotic pattern in the glandular epithelium between mated and nonmated rats were observed. Seminal vesicle secretions inhibited luminal epithelium apoptosis, while no changes in glandular epithelium apoptosis were observed. We also demonstrate that activation of caspases-8, -9, and -3 occurred in both mated and nonmated rats. Active caspase-3 was detected in the luminal and glandular epithelium in both nonmated and mated rats. The overall results indicate that mating delays but does not prevent the cellular death of the rat uterine luminal epithelium and seminal vesicle secretions are involved in this delay. Finally, the activation of both the mitochondrial and the membrane receptor pathways of cell death are implicated in the molecular mechanism of uterine apoptosis.