<abstract>Ageing in man is associated with a decline in testosterone following changes in the hypothalamo-pituitary testicular axis. This may offset the physiologic equilibrium between oestrogen and androgen and...<abstract>Ageing in man is associated with a decline in testosterone following changes in the hypothalamo-pituitary testicular axis. This may offset the physiologic equilibrium between oestrogen and androgen and at some point when the ratio of free testosterone to oestradiol reaches a critical level, the oestrogenic gonadotropin suppressive effect predominates with decreased release of FSH and LH. Adding to this endocrinal complexity is the continued peripheral conversion to oestradiol through aromatisation. Although the androgen deficiency is not the sole cause for impotence in the elderly, there is a gradual decrease in nocturnal penile tumescence (NPT) and spontaneous morning erections with ageing. Despite the age related increase in oestrogen levels, the information on the pathophysiological role of the 'female hormone' in erectile dysfunction has been scanty. Together with our identification of oestrogen receptors within the penile cavernosum, we have delineated dysfunctional changes on male erection mediated by oestradiol. These findings parallel the recent concerns over environmental oestrogens on fertility declines in young men. Oestrogenic activity is also present in plants and thereby in human diet. These phytoestrogens are structurally and functionally similar to oestradiol and more potent than the environmental oestrogenic chemicals such as organochlorine and phenolic compounds. Thus in the light of growing concerns of possible compromising effects on sexuality by endogenous and environmental oestrogens, we are faced with the scientific need to delineate their role on the mechanism of male erectile pathway in health and disease for clinical correlates and prognostics.展开更多
The androgen receptor （AR） plays a critical role in prostate cancer development and progression. This study aimed to use a computerized docking approach to examine the interactions between the human AR and phytooest...The androgen receptor （AR） plays a critical role in prostate cancer development and progression. This study aimed to use a computerized docking approach to examine the interactions between the human AR and phytooestrogens （genistein, daidzein, and flavone） and xeno-oestrogens （bisphenol A, 4-nonylphenol, dichlorodiphenyl trichloroethane [DDT], diethylstilbestrol [DES]）. The predicted three-dimensional structure of AR and androgens was established using X-ray diffraction. The binding of four xeno-oestrogens and three phyto-oestrogens to AR was analysed. The steroids estradiol and dihydrotestosterone （DHT） were used as positive controls and thyroxine as negative control. All the ligands shared the same binding site except for thyroxine. The endogenous hormones DHT and 17β-oestradiol showed the strongest binding with the lowest affinity energy （〈 -10 kcal mol-1）. All three phyto- oestrogens and two xeno-oestrogens （bisphenol A and DES） showed strong binding to AR. The affinities offlavone, genistein, and daidzein were between -8.8 and -8.5 kcal mol 1, while that of bisphenol A was -8.1 kcal mol-l and DES -8.3 kcal mol-1. Another two xeno-oestrogens, 4-nonylphenol and DDT, although they fit within the binding domain of AR, showed weak affinity （-6.4 and -6.7 kcal mol 1, respectively）. The phyto-oestrogens genistein, daidzein and flavone, and the xeno-oestrogens bisphenol A and DES can be regarded as androgenic effectors. The xenooestrogens DDT and 4-nonylphenol bind only weakly to AR.展开更多
AIM To evaluate sex differences and the effects of oestrogen administration in rat gastric mucosal defence.METHODS Sex differences in gastric mucus thickness and accumulation rate, absolute gastric mucosal blood flow ...AIM To evaluate sex differences and the effects of oestrogen administration in rat gastric mucosal defence.METHODS Sex differences in gastric mucus thickness and accumulation rate, absolute gastric mucosal blood flow using microspheres, the integrity of the gastric mucosal epithelium in response to a chemical irritant and the effects of oestrogen administration on relative gastric mucosal blood flow in an acute setting was assessed in an in vivo rat experimental model. Subsequently, sex differences in the distribution of oestrogen receptors and calcitonin gene related peptide in the gastric mucosa of animals exposed to oestrogen in the above experiments was evaluated using immunohistochemistry.RESULTS The absolute blood flow in the GI-tract was generally higher in males, but only significantly different in the corpus part of the stomach (1.12 ± 0.12 m L/min·g in males and 0.51 ± 0.03 m L/min·g in females) (P = 0.002). After removal of the loosely adherent mucus layer the thickness of the firmly adherent mucus layer in males and females was 79 ± 1 μm and 80 ± 3 μm respectively. After 60 min the mucus thickness increased to 113 ± 3 μm in males and 121 ± 3 μm in females with no statistically significant difference seen between the sexes. Following oestrogen administration(0.1 followed by 1 μg/kg·min), mean blood flow in the gastric mucosa decreased by 31% [68 ± 13 perfusion units (PFU)] in males which was significantly different compared to baseline(P = 0.02). In females however, mean blood flow remained largely unchanged with a 4% (5 ± 33 PFU) reduction. The permeability of the gastric mucosa increased to a higher level in females than in males (P = 0.01) after taurocholate challenge. However, the calculated mean clearance increase did not significantly differ between the sexes [0.1 ± 0.04 to 1.1 ± 0.1 m L/min·100 g in males and 0.4 ± 0.3 to 2.1 ± 0.3 m L/min·100 g in females(P = 0.065)]. There were no significant differences between 17β-Estradiol treated males (mean ratio of positive staining ± SEM)(0.06 ± 0.07) and females(0.11 ± 0.11) in the staining of ERα (P = 0.24). Also, there were no significant differences between 17β-Estradiol treated males (0.18 ± 0.21) and females (0.06 ± 0.12) in the staining of ERβ (P = 0.11). Finally, there were no significant differences between 17β-Estradiol treated males (0.04 ± 0.05) and females (0.11 ± 0.10) in the staining of CGRP(P = 0.14).CONCLUSION Gastric mucosal blood flow is higher in male than in female rats and is reduced in male rats by oestrogen administration.展开更多
Background Recent studies have suggested that estrogens are involved in normal and abnormal prostate growth, though their exact role is still controversial. Oestrogens exert inhibitory and stimulatory effects on prost...Background Recent studies have suggested that estrogens are involved in normal and abnormal prostate growth, though their exact role is still controversial. Oestrogens exert inhibitory and stimulatory effects on prostate gland, but the expression of oestrogen receptor-α （ERα） and oestrogen receptor-β （ERβ） in malignant prostate tissue remains unresolved. We determined ERa and ERβ in prostate cancer and investigated the relationship between expression of ER and pathological features of prostate carcinoma. Methods Thirty-two cases of prostate cancer, 12 cases of normal prostate tissue and 32 cases of benign prostate hyperplasia were analyzed for the expression of ERa and ERβ using semiquantitative, reverse transcription polymerase chain reaction （RT-PCR） and the products sequenced. Results Comparisons of the normal, hyperplastic and tumour prostate tissues indicated an overexpression of ERa in tumour specimens （P〈0.01）. However, the expression of ERβ significantly reduced in tumour tissues compared with normal and hyperplastic specimens （P〈0.01）, suggesting that severe pathological features of prostate cancer were associated with lower ERβ expression. Spearman analysis showed negative correlation between ERβ expression and tumour stage, grade （-0.67, -0.43, respectively, both P〈0.05）, and a positive correlation between ERα expression and tumour stage, grade （0.51, 0.57, respectively, both P〈0.01）. Our analysis also showed that hormone refractory, prostate cancer, compared with hormone dependent, prostate cancer, displayed a decreased expression of ERβ （P〈0.01） and an increased expression of ERa. Conclusions ERα and ERβ may play important roles in the development of prostate cancer. The decrease in ERβ expression is associated with higher Gleason grade tumours and prostate cancer with higher metastatic potential. The loss of ERβ could be one of the key processes leading to uncontrolled growth of prostate epithelial cells.展开更多
We cloned the three androgen response elements（AREs, including AREI, AREII, and AREIII ） with a core transactivation TATA element of the prostate-specific antigen（PSA） promoter into pGL2 basic vector to create an ...We cloned the three androgen response elements（AREs, including AREI, AREII, and AREIII ） with a core transactivation TATA element of the prostate-specific antigen（PSA） promoter into pGL2 basic vector to create an artificial pGL2/AREs-TATA reporter system, which was applied to evaluating the effects of different xeno- oestrogens[bisphenol A（BPA）, 4-nonylphenol（4-NP）, dichlorodiphenyl trichloroethane（DDT） or diethylstilbestrol （DES）] on androgen receptor（AR） abnormal activation to regulate PSA expression and cell proliferation. In all the three AREs, AREIII-TATA displayed as a major element responsive to AR-mediated DHT stimulation of PSA promoter. Therefore, pGL2/AREIII-TATA reporter was adopted to analyze the activation capacity of AR activated by four different xeno-oestrogens. The activation of pGL2/AREIII-TATA reporter by each xeno-oestrogen was analyzed in two different cell lines, one was HEK293T（Human Embryonic Kidney 293T） cell line, and the other was AR stably expressed DU145 cell line, which was produced by infecting AR with pLenti-puro-AR into the prostate cancer DU145 cells and that were scanned with puromycin and tested by AR antibody. In both the two cell lines, BPA or DES significantly induced AR-mediated transcriptional activity of AREIII-TATA reporter, whereas DDT or 4-nonylphenol did not. Moreover, AR-mediated cell proliferation in response to each of four xeno-oestrogens was measured in MTT assays in both HEK293T cell or AR stably expressed DUI45 cell lines. BPA or DES, as an AR inducer, exhibited an enhanced effect in cell proliferation, rather than the effect of DDT or 4-NP, in both cell lines. Finally, we demonstrated that BPA or DES stimulated PSA expression and enhanced the recruitment of AR onto the PSA promoter, resulting in stronger binding to AREIII sites. Taken together, four xeno-oestrogens were identified to have different activities on AR. BPA and DES are demonstrated to be androgenic effectors in the regulation of PSA activation or cell proliferation.展开更多
文摘<abstract>Ageing in man is associated with a decline in testosterone following changes in the hypothalamo-pituitary testicular axis. This may offset the physiologic equilibrium between oestrogen and androgen and at some point when the ratio of free testosterone to oestradiol reaches a critical level, the oestrogenic gonadotropin suppressive effect predominates with decreased release of FSH and LH. Adding to this endocrinal complexity is the continued peripheral conversion to oestradiol through aromatisation. Although the androgen deficiency is not the sole cause for impotence in the elderly, there is a gradual decrease in nocturnal penile tumescence (NPT) and spontaneous morning erections with ageing. Despite the age related increase in oestrogen levels, the information on the pathophysiological role of the 'female hormone' in erectile dysfunction has been scanty. Together with our identification of oestrogen receptors within the penile cavernosum, we have delineated dysfunctional changes on male erection mediated by oestradiol. These findings parallel the recent concerns over environmental oestrogens on fertility declines in young men. Oestrogenic activity is also present in plants and thereby in human diet. These phytoestrogens are structurally and functionally similar to oestradiol and more potent than the environmental oestrogenic chemicals such as organochlorine and phenolic compounds. Thus in the light of growing concerns of possible compromising effects on sexuality by endogenous and environmental oestrogens, we are faced with the scientific need to delineate their role on the mechanism of male erectile pathway in health and disease for clinical correlates and prognostics.
基金This study was supported by Ministry of Science and Technology （No. 2010DFA31430）, the National Natural Science Foundation of China （No. 30871301, 30700827）, Ministry of Education of China （No. 108047）, Jilin Provincial Science ＆ Technology Department （No. 20070719, 20080731, 200905116）. We thank Mr Michael Hoyt, who critically read and revised our manuscript.
文摘The androgen receptor （AR） plays a critical role in prostate cancer development and progression. This study aimed to use a computerized docking approach to examine the interactions between the human AR and phytooestrogens （genistein, daidzein, and flavone） and xeno-oestrogens （bisphenol A, 4-nonylphenol, dichlorodiphenyl trichloroethane [DDT], diethylstilbestrol [DES]）. The predicted three-dimensional structure of AR and androgens was established using X-ray diffraction. The binding of four xeno-oestrogens and three phyto-oestrogens to AR was analysed. The steroids estradiol and dihydrotestosterone （DHT） were used as positive controls and thyroxine as negative control. All the ligands shared the same binding site except for thyroxine. The endogenous hormones DHT and 17β-oestradiol showed the strongest binding with the lowest affinity energy （〈 -10 kcal mol-1）. All three phyto- oestrogens and two xeno-oestrogens （bisphenol A and DES） showed strong binding to AR. The affinities offlavone, genistein, and daidzein were between -8.8 and -8.5 kcal mol 1, while that of bisphenol A was -8.1 kcal mol-l and DES -8.3 kcal mol-1. Another two xeno-oestrogens, 4-nonylphenol and DDT, although they fit within the binding domain of AR, showed weak affinity （-6.4 and -6.7 kcal mol 1, respectively）. The phyto-oestrogens genistein, daidzein and flavone, and the xeno-oestrogens bisphenol A and DES can be regarded as androgenic effectors. The xenooestrogens DDT and 4-nonylphenol bind only weakly to AR.
文摘AIM To evaluate sex differences and the effects of oestrogen administration in rat gastric mucosal defence.METHODS Sex differences in gastric mucus thickness and accumulation rate, absolute gastric mucosal blood flow using microspheres, the integrity of the gastric mucosal epithelium in response to a chemical irritant and the effects of oestrogen administration on relative gastric mucosal blood flow in an acute setting was assessed in an in vivo rat experimental model. Subsequently, sex differences in the distribution of oestrogen receptors and calcitonin gene related peptide in the gastric mucosa of animals exposed to oestrogen in the above experiments was evaluated using immunohistochemistry.RESULTS The absolute blood flow in the GI-tract was generally higher in males, but only significantly different in the corpus part of the stomach (1.12 ± 0.12 m L/min·g in males and 0.51 ± 0.03 m L/min·g in females) (P = 0.002). After removal of the loosely adherent mucus layer the thickness of the firmly adherent mucus layer in males and females was 79 ± 1 μm and 80 ± 3 μm respectively. After 60 min the mucus thickness increased to 113 ± 3 μm in males and 121 ± 3 μm in females with no statistically significant difference seen between the sexes. Following oestrogen administration(0.1 followed by 1 μg/kg·min), mean blood flow in the gastric mucosa decreased by 31% [68 ± 13 perfusion units (PFU)] in males which was significantly different compared to baseline(P = 0.02). In females however, mean blood flow remained largely unchanged with a 4% (5 ± 33 PFU) reduction. The permeability of the gastric mucosa increased to a higher level in females than in males (P = 0.01) after taurocholate challenge. However, the calculated mean clearance increase did not significantly differ between the sexes [0.1 ± 0.04 to 1.1 ± 0.1 m L/min·100 g in males and 0.4 ± 0.3 to 2.1 ± 0.3 m L/min·100 g in females(P = 0.065)]. There were no significant differences between 17β-Estradiol treated males (mean ratio of positive staining ± SEM)(0.06 ± 0.07) and females(0.11 ± 0.11) in the staining of ERα (P = 0.24). Also, there were no significant differences between 17β-Estradiol treated males (0.18 ± 0.21) and females (0.06 ± 0.12) in the staining of ERβ (P = 0.11). Finally, there were no significant differences between 17β-Estradiol treated males (0.04 ± 0.05) and females (0.11 ± 0.10) in the staining of CGRP(P = 0.14).CONCLUSION Gastric mucosal blood flow is higher in male than in female rats and is reduced in male rats by oestrogen administration.
文摘Background Recent studies have suggested that estrogens are involved in normal and abnormal prostate growth, though their exact role is still controversial. Oestrogens exert inhibitory and stimulatory effects on prostate gland, but the expression of oestrogen receptor-α （ERα） and oestrogen receptor-β （ERβ） in malignant prostate tissue remains unresolved. We determined ERa and ERβ in prostate cancer and investigated the relationship between expression of ER and pathological features of prostate carcinoma. Methods Thirty-two cases of prostate cancer, 12 cases of normal prostate tissue and 32 cases of benign prostate hyperplasia were analyzed for the expression of ERa and ERβ using semiquantitative, reverse transcription polymerase chain reaction （RT-PCR） and the products sequenced. Results Comparisons of the normal, hyperplastic and tumour prostate tissues indicated an overexpression of ERa in tumour specimens （P〈0.01）. However, the expression of ERβ significantly reduced in tumour tissues compared with normal and hyperplastic specimens （P〈0.01）, suggesting that severe pathological features of prostate cancer were associated with lower ERβ expression. Spearman analysis showed negative correlation between ERβ expression and tumour stage, grade （-0.67, -0.43, respectively, both P〈0.05）, and a positive correlation between ERα expression and tumour stage, grade （0.51, 0.57, respectively, both P〈0.01）. Our analysis also showed that hormone refractory, prostate cancer, compared with hormone dependent, prostate cancer, displayed a decreased expression of ERβ （P〈0.01） and an increased expression of ERa. Conclusions ERα and ERβ may play important roles in the development of prostate cancer. The decrease in ERβ expression is associated with higher Gleason grade tumours and prostate cancer with higher metastatic potential. The loss of ERβ could be one of the key processes leading to uncontrolled growth of prostate epithelial cells.
文摘We cloned the three androgen response elements（AREs, including AREI, AREII, and AREIII ） with a core transactivation TATA element of the prostate-specific antigen（PSA） promoter into pGL2 basic vector to create an artificial pGL2/AREs-TATA reporter system, which was applied to evaluating the effects of different xeno- oestrogens[bisphenol A（BPA）, 4-nonylphenol（4-NP）, dichlorodiphenyl trichloroethane（DDT） or diethylstilbestrol （DES）] on androgen receptor（AR） abnormal activation to regulate PSA expression and cell proliferation. In all the three AREs, AREIII-TATA displayed as a major element responsive to AR-mediated DHT stimulation of PSA promoter. Therefore, pGL2/AREIII-TATA reporter was adopted to analyze the activation capacity of AR activated by four different xeno-oestrogens. The activation of pGL2/AREIII-TATA reporter by each xeno-oestrogen was analyzed in two different cell lines, one was HEK293T（Human Embryonic Kidney 293T） cell line, and the other was AR stably expressed DU145 cell line, which was produced by infecting AR with pLenti-puro-AR into the prostate cancer DU145 cells and that were scanned with puromycin and tested by AR antibody. In both the two cell lines, BPA or DES significantly induced AR-mediated transcriptional activity of AREIII-TATA reporter, whereas DDT or 4-nonylphenol did not. Moreover, AR-mediated cell proliferation in response to each of four xeno-oestrogens was measured in MTT assays in both HEK293T cell or AR stably expressed DUI45 cell lines. BPA or DES, as an AR inducer, exhibited an enhanced effect in cell proliferation, rather than the effect of DDT or 4-NP, in both cell lines. Finally, we demonstrated that BPA or DES stimulated PSA expression and enhanced the recruitment of AR onto the PSA promoter, resulting in stronger binding to AREIII sites. Taken together, four xeno-oestrogens were identified to have different activities on AR. BPA and DES are demonstrated to be androgenic effectors in the regulation of PSA activation or cell proliferation.
