Association between urinary concentrations of bisphenol A substitutes and diabetes in adults.

BACKGROUND: Due to new restrictions on the use of bisphenol A (BPA), industries are beginning to replace it with derived molecules such as bisphenol S and F (BPS and BPF). There is extensive evidence in the academic literature on the potential health effects of BPA, which is known to be a diabetogenic molecule. However, there are few publications related to new compounds derived from BPA. AIM: To perform an epidemiological study of urinary BPS and BPF in the American National Health and Nutrition Examination Survey (NHANES) cohort, and analyze their possible relationship with diabetes mellitus. METHODS: NHANES datasets from 2013 to 2016 were used due to the urinary BPF and BPS availability. Data from 3658 adults were analyzed to perform regression analysis exploring the possible relationship between BPA-derived compounds and diabetes. RESULTS: Descriptive statistics, linear regression modeling, and logistic regression analysis revealed a significant relationship between urinary BPS, but not BPF, and diabetes risk. Additionally, a relationship was observed between both compounds and hypertension and a slight relationship between BPF and dyslipidemia. CONCLUSION: In the present study, a strong relationship between urinary BPS, not BPF, and diabetes risk has been determined. BPA substitute molecules do not exempt the population from potential health risks.

Comparison of the renal effects of bisphenol A in mice with and without experimental diabetes. Role of sexual dimorphism.

Bisphenol-A (BPA), a chemical -xenoestrogen- used in the production of the plastic lining of food and beverage containers, is present in the urine of almost the entire population. Recent studies have shown that BPA exposure is associated with podocytopathy, increased urinary albumin excretion (UAE), and hypertension. Since these changes are characteristic of early diabetic nephropathy (DN), we explored the renal effects of BPA and diabetes including the potential role of sexual dimorphism. Male and female mice were included in the following animals' groups: control mice (C), mice treated with 21.2 mg/kg of BPA in the drinking water (BPA), diabetic mice induced by streptozotocin (D), and D mice treated with BPA (D + BPA). Male mice form the D + BPA group died by the tenth week of the study due probably to hydro-electrolytic disturbances. Although BPA treated mice did not show an increase in serum creatinine, as observed in D and D + BPA groups, they displayed similar alteration to those of the D group, including increased in kidney damage biomarkers NGAL and KIM-1, UAE, hypertension, podocytopenia, apoptosis, collapsed glomeruli, as well as TGF-ß, CHOP and PCNA upregulation. UAE, collapsed glomeruli, PCNA staining, TGF-ß, NGAL and animal survival, significantly impaired in D + BPA animals. Moreover, UAE, collapsed glomeruli and animal survival also displayed a sexual dimorphism pattern. In conclusion, oral administration of BPA is capable of promoting in the kidney alterations that resemble early DN. Further translational studies are needed to clarify the potential role of BPA in renal diseases, particularly in diabetic patients.

New Evidence of Renal and Cardiovascular Alterations Promoted by Bisphenol A.

Bisphenol A (BPA) is a phenolic compound that is widely used to synthesize plastics as a monomer or additive [...].

Bisphenol a Exposure and Kidney Diseases: Systematic Review, Meta-Analysis, and NHANES 03-16 Study.

Bisphenol A (BPA) is a compound that is especially widespread in most commonly used objects due to its multiple uses in the plastic industry. However, several data support the need to restrict its use. In recent years, new implications of BPA on the renal system have been discovered, which denotes the need to expand studies in patients. To this end, a systematic review and a meta-analysis was performed to explore existing literature that examines the BPA-kidney disease paradigm and to determine what and how future studies will need to be carried out. Our systematic review revealed that only few relevant publications have focused on the problem. However, the subsequent meta-analysis revealed that high blood concentrations of BPA could be a factor in developing kidney disease, at least in people with previous pathologies such as diabetes or hypertension. Furthermore, BPA could also represent a risk factor in healthy people whose urinary excretion is higher. Finally, the data analyzed from the NHANES 03-16 cohort provided new evidence on the possible involvement of BPA in kidney disease. Therefore, our results underline the need to carry out a thorough and methodologically homogeneous study, delving into the relationship between urinary and blood BPA, glomerular filtration rate, and urine albumin-to-creatinine ratio, preferably in population groups at risk, and subsequently in the general population, to solve this relevant conundrum with critical potential implications in Public Health.

Bisphenol A impaired cell adhesion by altering the expression of adhesion and cytoskeleton proteins on human podocytes.

Bisphenol A (BPA), a chemical -xenoestrogen- used in food containers is present in the urine of almost the entire population. Recently, several extensive population studies have proven a significant association between urinary excretion of BPA and albuminuria. The alteration of glomerular podocytes or "podocytopathy" is a common event in chronic albuminuric conditions. Since many podocytes recovered from patients' urine are viable, we hypothesized that BPA could impair podocyte adhesion capabilities. Using an in vitro adhesion assay, we observed that BPA impaired podocyte adhesion, an effect that was abrogated by Tamoxifen (an estrogen receptor blocker). Genomic and proteomic analyses revealed that BPA affected the expression of several podocyte cytoskeleton and adhesion proteins. Western blot and immunocytochemistry confirmed the alteration in the protein expression of tubulin, vimentin, podocin, cofilin-1, vinculin, E-cadherin, nephrin, VCAM-1, tenascin-C, and ß-catenin. Moreover, we also found that BPA, while decreased podocyte nitric oxide production, it lead to overproduction of ion superoxide. In conclusion, our data show that BPA induced a novel type of podocytopathy characterizes by an impairment of podocyte adhesion, by altering the expression of adhesion and cytoskeleton proteins. Moreover, BPA diminished production of podocyte nitric oxide and induced the overproduction of oxygen-free metabolites. These data provide a mechanism by which BPA could participate in the pathogenesis and progression of renal diseases.

Expression of retinoic acid receptors and retinoid X receptors in normal and vitamin A deficient adult rat brain.

The importance of retinoic acid and retinoid X receptors (RARs and RXRs) in the metabolism and functioning of the nervous tissue is well documented, but few data are available about the differences on their distribution in males and females, as well as about the possible changes in a vitamin A deficient state (VAD). Therefore, the aim of this study has been to use immunohistochemistry to determine the cellular localization of RARs (α, ß, γ) and RXR (α, ß, γ) in brain areas in the normal and vitamin A deficient rat, in both males and females. RARα and ß isotypes were detected in practically all the male brain areas whereas immunostaining was weak or absent in the female brain except RARα. RXRγ was absent in the female brain, while it was observed in some regions in the male. RXRß and γ were the most abundant receptors in both sexes, but RXRα were hardly detected in female brain, but were detected more frequently in male. With a vitamin A-free diet, RARs expression was increased in males, but not in females. In the male brain of VAD rats, RXRα expression was increased in some zones and diminished in others. RXRß and γ expression was decreased in the male brain, but increased or was not modified in those areas of the female brain in which it was observed. These findings indicate that the brain management of retinoic acid differs between males and females, also leading to differences in their response to VAD diet in terms of receptor expression.

Effect of liver growth factor on both testicular regeneration and recovery of spermatogenesis in busulfan-treated mice.

BACKGROUND: Some adult stem cells persist in adult tissue; however, we do not know how to stimulate stem cells in adults to heal injuries. Liver growth factor (LGF) is a biliprotein with hepatic mitogen activity. Its concentration increases markedly in the presence of any type of liver injury, and it shows in vivo therapeutic biological activity at extrahepatic sites. METHODS: We have analyzed the effect of LGF on the replenishment of germinal cells in the testes of mice injected with busulfan, a common cancer drug that also specifically affects germ line stem cells and spermatogonia. We determined the testicular and epididymal weight, spermatozoal concentration in the epididymis and sperm motility, and performed a histological analysis. RESULTS: Intraperitoneal administration of LGF was able to partially restore spermatogenesis, as well as sperm production and motility, in mice sterilized with busulfan. LGF treatment in busulfan-treated animals that have suffered a disruption of spermatogenesis can accelerate the reactivation of this process in most of the tubules, as shown in the histological analysis. CONCLUSIONS: Our results suggest a potential use of LGF in the mobilization of testicular stem cells and in the restoration of spermatogenesis after busulfan-induced damage to the testicular germinal epithelium.

15-Deoxy-Delta(12,14)-prostaglandin-J(2) reveals a new pVHL-independent, lysosomal-dependent mechanism of HIF-1alpha degradation.

Hypoxia-inducible factor-1alpha (HIF-1alpha) protein is degraded under normoxia by its association to von Hippel-Lindau protein (pVHL) and further proteasomal digestion. However, human renal cells HK-2 treated with 15-deoxy-Delta(12,14)-prostaglandin-J(2) (15d-PGJ(2)) accumulate HIF-1alpha in normoxic conditions. Thus, we aimed to investigate the mechanism involved in this accumulation. We found that 15d-PGJ(2) induced an over-accumulation of HIF-1alpha in RCC4 cells, which lack pVHL and in HK-2 cells treated with inhibitors of the pVHL-proteasome pathway. These results indicated that pVHL-proteasome-independent mechanisms are involved, and therefore we aimed to ascertain them. We have identified a new lysosomal-dependent mechanism of HIF-1alpha degradation as a target for 15d-PGJ(2) based on: (1) HIF-1alpha colocalized with the specific lysosomal marker Lamp-2a, (2) 15d-PGJ(2) inhibited the activity of cathepsin B, a lysosomal protease, and (3) inhibition of lysosomal activity did not result in over-accumulation of HIF-1alpha in 15d-PGJ(2)-treated cells. Therefore, expression of HIF-1alpha is also modulated by lysosomal degradation.

Human pregnane X receptor is expressed in breast carcinomas, potential heterodimers formation between hPXR and RXR-alpha.

BACKGROUND: The human pregnane X receptor (hPXR) is an orphan nuclear receptor that induces transcription of response elements present in steroid-inducible cytochrome P-450 gene promoters. This activation requires the participation of retinoid X receptors (RXRs), needed partners of hPXR to form heterodimers. We have investigated the expression of hPXR and RXRs in normal, premalignant, and malignant breast tissues, in order to determine whether their expression profile in localized infiltrative breast cancer is associated with an increased risk of recurrent disease. METHODS: Breast samples from 99 patients including benign breast diseases, in situ and infiltrative carcinomas were processed for immunohistochemistry and Western-blot analysis. RESULTS: Cancer cells from patients that developed recurrent disease showed a high cytoplasmic location of both hPXR isoforms. Only the infiltrative carcinomas that relapsed before 48 months showed nuclear location of hPXR isoform 2. This location was associated with the nuclear immunoexpression of RXR-alpha. CONCLUSION: Breast cancer cells can express both variants 1 and 2 of hPXR. Infiltrative carcinomas that recurred showed a nuclear location of both hPXR and RXR-alpha; therefore, the overexpression and the subcellular location changes of hPXR could be considered as a potential new prognostic indicator.

Glucocorticoid receptor changes its cellular location with breast cancer development.

Glucocorticoids play a major role in attenuation of the inflammatory response and they are useful in the primary combination chemotherapy of breast cancer, since in vitro studies have demonstrated an antiproliferative effect in human breast cancer cells. In contrast, it was recently shown that glucocorticoids protect against apoptotic signals evoked by cytokines, cAMP, tumour suppressors, and death genes in mammary gland epithelia. Their actions are mediated by intracellular receptor (GR) that functions as a hormone-dependent transcription factor; however, no previous studies have been focused on GR expression in different pathologies of the human breast, and the possible relationship with that of mineralocorticoid receptor (MR) and COX-2. Also, the role of these proteins on tumoral breast epithelial cells remains unclear. Therefore, we examined GR, MR and COX-2 expression by immunohistochemistry and Western blot techniques in 142 samples of human breast obtained by total or partial mastectomy. We found that the percentage of positive patients presenting nuclear immunoreaction to GR decreased with tumor development, while all samples analyzed showed cytoplasmic immunoreactions to MR. All positive samples to COX-2 antibody showed cytoplasmic location, a higher immunoreaction being observed in benign breast diseases than in carcinomatous lesions. Thus, breast cancer progression is associated with the accumulation of GR in the cytoplasm of tumoral cells and the decrease of COX-2 expression.

Nestin, a neuroectodermal stem cell marker molecule, is expressed in Leydig cells of the human testis and in some specific cell types from human testicular tumours.

The intermediate filament protein nestin is predominantly expressed in some stem/progenitor cells and appears to be a useful molecular tool to characterise tumours originating from precursor cells of neuroectodermal and mesenchymal lineages. Leydig cells originate in the adult testis by differentiation from stem cells and express a variety of neural and neuroendocrine markers. The possible expression of the neural stem cell marker nestin in Leydig cells and testicular tumour cells was determined by analysing the patterns of nestin expression in normal and pathological human testes by Western blot and immunohistochemical methods. In normal testis, nestin was found in some vascular endothelial cells, a subset of peritubular spindle-shaped cells and some Leydig cells; spermatogenic and Sertoli cells were unstained. In normal Leydig cells, nestin was distributed in the perinuclear cytoplasm and accumulated in the crystalloids of Reinke with ageing. In non-tumour pathologies (cryptorchidism, impaired spermatogenesis), the seminiferous tubules were immunonegative, whereas hyperplastic Leydig cells showed cytoplasmic immunolabelling. In testicular malignancies, nestin was localised in the Sertoli cells of the seminiferous tubules affected with intratubular germ cell neoplasia, in the hyperplastic Leydig cells associated with these tumours and in some components (mesenchymal and neuroepithelial cells) of teratomas; spermatocytic and non-spermatocytic seminomas were unstained. Some vascular endothelial cells were immunolabelled in all tumour samples. Thus, nestin is expressed in a population of normal and hyperplastic Leydig cells and in Sertoli cells in the presence of intratubular germ-cell neoplasia. Nestin may be a good marker for identifying components of testicular teratomas.

DAX-1 expression in human breast cancer: comparison with estrogen receptors ER-alpha, ER-beta and androgen receptor status.

BACKGROUND: So far there have been no reports on the expression pattern of DAX-1 (dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1) in human breast cells and its relationship to the estrogen receptors, ER-alpha and ER-beta, and the androgen receptor (AR). METHODS: In this study we evaluated, by immunohistochemistry and Western blot analysis, the presence and distribution of DAX-1 in benign breast disease (BBD), in situ carcinoma (CIS), and ductal and lobular breast carcinomas. RESULTS: In BBD and breast carcinomas, DAX-1 was present in both the nuclei and the cytoplasm of epithelial cells, although in infiltrative carcinomas the percentage of nuclear immunoreaction was higher than in CIS. An important relation was observed between DAX-1 and AR expression and between this orphan receptor and nodal status. CONCLUSION: DAX-1 might modify the AR and ER-beta intracellular location, and because a direct positive relation between the expression of these three receptors was found it could be assumed that the presence of DAX-1 in neoplastic cells might indicate a possible failure of endocrine therapies.

Normal and pathological human testes express hormone-sensitive lipase and the lipid receptors CLA-1/SR-BI and CD36.

Numerous studies have demonstrated the important role of cholesterol and cholesteryl esters in tumor cell proliferation and progression of cancer. However, few studies have focused on the role of lipid transporters and lipases in cancer development and progression. The present study examined the expression of hormone-sensitive lipase (HSL) and the scavenger receptors CLA-1/SR-BI and CD36 in normal human testis and in nontumor and tumor testicular disorders by immunohistochemistry and Western blotting analysis. In normal young testes, immunoreaction to CLA-1/SR-BI was found in the spermatid acrosomic vesicle and on the surface of Sertoli and Leydig cells. HSL was detected in spermatogonia, the Golgi region of spermatocytes, the nucleus of spermatids, and the cytoplasm of both Sertoli and Leydig cells. Elderly testes and testes with hypospermatogenesis showed a similar staining pattern to that of normal young testes except for CD36, which was expressed in Sertoli cells. Cryptorchid testes demonstrated intense labeling to HSL and weak labeling to SR-BI in Sertoli cells (nucleus and cytoplasm) and Leydig cells (cytoplasm). Seminiferous tubules with intratubular germ cell neoplasia exhibited intense immunolabeling to the 3 lipid receptors in the surface of neoplastic cells and to HSL in the nucleus. In seminoma and spermatocytic seminoma, neoplastic cells labeled to HSL but failed to stain with antilipid receptors; in the seminiferous tubules at the periphery of the tumour, Charcot-Böttcher crystalloids of Sertoli cells were strongly positive to CLA-1. Testes with mature teratoma showed a weak reaction to CD36 and SR-BI in some cells of enteric-type glands, and immature teratoma were exclusively immunolabeled with HSL. Western blotting analysis revealed that multiple bands were immunolabeled, with differences seen between normal and pathological testes. The results of this study indicate that the presence of lipid receptors (CLA-1/SR-BI) and hormone-sensitive lipase in Leydig cells suggests a role of these proteins in steroidogenesis. Also, these proteins seem to be involved in spermiogenesis, as their labeling in spermatids suggests. In nonmalignant and malignant pathologies, cholesterol metabolism is probably altered, and HSL labeling in neoplastic germ cell nuclei suggests a still-unknown function of this enzyme, probably related to cell cycle regulation.

Immunohistochemical detection of the retinoid X receptors alpha, beta, and gamma in human prostate.

The aim of this study was to evaluate the presence and distribution of retinoid X receptors (RXRs) alpha, beta, and gamma in normal, hyperplastic (nodular, basal cell, and atrophic hyperplasia), and carcinomatous human prostates in order to elucidate the relationship among these receptors and the onset and development of prostatic adenocarcinoma. RXRalpha and RXRgamma were immunodetected in all samples of normal, nodular, and basal cell hyperplasia, as well as carcinomatous prostates. In atrophic glands, the expression of both receptors was found in 22.5% of samples. Positive immunostaining for RXRbeta was observed in 53.3% of normal prostates, 100% of samples showed basal cell hyperplasia, and were negative in nodular and atrophic hyperplasia. In prostatic adenocarcinoma, only 3 of 25 samples (the 3 diagnosed as well-differentiated) were positive for RXRbeta. Results suggest that diminished RXRbeta expression might be related to prostate cancer progression and because the responsiveness to retinoic acid treatments depends on the expression of different receptors, it is important to study their expression before therapy.

Ultrastructural staining with sodium metaperiodate and sodium borohydride.

This article describes new ultrastructural staining methods for osmicated tissues based on the incubation of sections with sodium metaperiodate and sodium borohydride solutions before uranyl/lead staining. Sections incubated with sodium metaperiodate and sodium borohydride, treated with Triton X-100, and stained with ethanolic uranyl acetate/lead citrate showed a good contrast for the nucleolus and the interchromatin region, whereas the chromatin masses were bleached. Chromatin bleaching depended on the incubation with these oxidizing (metaperiodate) and reducing (borohydride) agents. Other factors that influenced the staining of the chromatin masses were the en bloc staining with uranyl acetate, the incubation of sections with Triton X-100, and the staining with aqueous or ethanolic uranyl acetate. The combination of these factors on sections treated with metaperiodate/borohydride provided a different appearance to the chromatin, from bleached to highly contrasted. Most cytoplasmic organelles showed a similar appearance with these procedures than with conventional uranyl/lead staining. However, when sections were incubated with metaperiodate/borohydride and Triton X-100 before uranyl/lead staining, the collagen fibers, and the glycocalix and zymogen granules of pancreatic acinar cells, appeared bleached. The possible combination of these methods with the immunolocalization of the amino acid taurine was also analyzed. (J Histochem Cytochem 50:11-19, 2002)