Tributyltin and high-refined carbohydrate diet lead to metabolic and reproductive abnormalities, exacerbating premature ovary failure features in the female rats

Subacute exposure to a mixture of tributyltin plus mercury impairs reproductive axis function, exacerbating premature ovarian insufficiency features and reducing fertility in female rats

Tributyltin (TBT) and mercury (Hg) are endocrine-disrupting chemicals that individually cause reproductive complications. However, the reproductive consequences of exposure to a mixture of TBT plus Hg are not well known. We hypothesized that exposure to a mixture of TBT plus Hg would alter hypothalamic-pituitary-gonadal (HPG) axis function. Female rats were exposed to this mixture daily for 15 days, after which chemical accumulation in the tissues, morphology, hormone levels, inflammation, fibrosis, and protein expression in the reproductive organs were assessed. Increases in tin (Sn) and Hg levels were detected in the serum, HPG axis, and uterus of TBT-Hg rats. TBT-Hg rats exhibited irregular estrous cycles. TBT-Hg rats showed an increase in gonadotropin-releasing hormone (GnRH) protein expression and follicle-stimulating hormone (FSH) levels and a reduction in luteinizing hormone (LH) levels. Reduced ovarian reserve, antral follicles, corpora lutea (CL) number, and estrogen levels and increased atretic and cystic follicles were found, suggesting that TBT-Hg exposure exacerbated premature ovarian insufficiency (POI) features. Furthermore, TBT-Hg rats exhibited increased ovarian mast cell numbers, expression of the inflammatory markers IL-6 and collagen deposition. Apoptosis and reduced gland number were observed in the uteri of TBT-Hg rats. A reduction in the number of pups/litter for 90 days was found in TBT-Hg rats, suggesting impaired fertility. Strong negative correlations were found between serum and ovarian Sn levels and ovarian Hg levels and ovarian reserve and CL number. Collectively, these data suggest that TBT plus Hg exposure leads to abnormalities in the HPG axis, exacerbating POI features and reducing fertility in female rats.

Subacute tributyltin exposure alters the development and morphology of mammary glands in association with CYP19A1 expression in female rats

Tributyltin (TBT) is an endocrine-disrupting chemical (EDC) related to reproductive dysfunctions. However, few studies have investigated the effects of TBT exposure on mammary gland development. Thus, we assessed whether subacute TBT exposure causes irregularities in mammary gland development. We administered TBT (100 and 1,000 ng/kg/day for 30 days) to female rats from postnatal day (PND) 25 to PND 55, and mammary gland development, morphology, inflammation, collagen deposition, and protein expression were evaluated. Abnormal mammary gland development was observed in both TBT groups. Specifically, TBT exposure reduced the number of terminal end buds (TEBs), type 1 (AB1) alveolar buds, and type 2 (AB2) alveolar buds. An increase in the lobule and differentiation (DF) 2 score was found in the mammary glands of TBT rats. TBT exposure increased mammary gland blood vessels, mast cell numbers, and collagen deposition. Additionally, both TBT rats exhibited intraductal hyperplasia and TEB-like structures. An increase in estrogen receptor alpha (ERα), progesterone receptor (PR), and cytochrome P450 family 19 subfamily A member 1 (CYP19A1) - positive cells was observed in the mammary glands of TBT rats. A strong negative correlation was observed between CYP19A1- positive cells and TEB number. In addition, CYP19A1 - positive cells were positively correlated with mammary gland TEB-like structure, ductal hyperplasia, inflammation, and collagen deposition. Thus, these data suggest that TBT exposure impairs mammary gland development through the modulation of CYP19A1 signaling pathways in female rats.

Single microcystin exposure impairs the hypothalamic-pituitary-gonadal axis at different levels in female rats

Microcystin (MC) is most common cyanobacterial toxin. Few studies have evaluated the MC effects on the hypothalamic-pituitary-gonadal (HPG) axis and metabolic function. In this study, we assessed whether MC exposure results in HPG axis and metabolic changes. Female rats were exposed to a single dose of MC at environmentally relevant levels (5, 20 and 40 μg/kg). After 24 h, we evaluated reproductive and metabolic parameters for 15 days. MC reduced the hypothalamic GnRH protein expression, increased the pituitary protein expression of GnRHr and IL-6. MC reduced LH levels and increased FSH levels. MC reduced the primary follicles, increased the corpora lutea, elevated levels of anti-Müllerian hormone (AMH) and progesterone, and decreased estrogen levels. MC increased ovarian VEGFr, LHr, AMH, ED1, IL-6 and Gp91-phox protein expression. MC increased uterine area and reduced endometrial gland number. A blunted estrogen-negative feedback was observed in MC rats after ovariectomy, with no changes in LH levels compared to intact MC rats. Therefore, these data suggest that a MC leads to abnormal HPG axis function in female rats.

Subacute cadmium exposure changes different metabolic functions, leading to type 1 and 2 diabetes mellitus features in female rats

Cadmium (Cd) is a heavy metal that acts as endocrine disrupting chemical (EDC). Few studies have investigated the effects of Cd exposure on metabolic dysfunctions, such as type 1 and 2 diabetes mellitus (T1DM and T2DM). Thus, we assessed whether subacute Cd exposure at occupational levels causes abnormalities in white adipose tissue (WAT), liver, pancreas, and skeletal muscle. We administered cadmium chloride (CdCl2) (100 ppm in drinking water for 30 days) to female rats and evaluated Cd levels in serum and metabolic organs, morphophysiology, inflammation, oxidative stress, fibrosis, and gene expression. High Cd levels were found in serum, WAT, liver, pancreas, and skeletal muscle. Cd-exposed rats showed low adiposity, dyslipidemia, insulin resistance, systemic inflammation, and oxidative stress compared to controls. Cd exposure reduced adipocyte size, hyperleptinemia, increased cholesterol levels, inflammation, apoptosis and fibrosis in WAT. Cd-exposed rats had increased liver cholesterol levels, insulin receptor beta (IRβ) and peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC1α) expression, karyomegaly, inflammation, and fibrosis. Cd exposure reduced insulin levels and pancreatic islet size and increased inflammation and fibrosis. Cd exposure reduced skeletal muscle fiber diameter and increased IR expression and inflammation. Finally, strong positive correlations were observed between serum, tissue Cd levels, abnormal morphology, tissue inflammation and fibrosis. Thus, these data suggest that subacute Cd exposure impairs WAT, liver, pancreas and skeletal muscle function, leading to T1DM and T2DM features and other complications in female rats.

Zishen Yutai pills restore fertility in premature ovarian failure through regulating arachidonic acid metabolism and the ATK pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The Zishen Yutai pills (ZYP), a Chinese medicinal formulation derived from the Qing Dynasty prescription "Shou Tai pills", have been documented to exhibit beneficial effects in clinical observations treating premature ovarian failure (POF). However, the anti-POF effects and its comprehensive systemic mechanism have not yet been clarified.

AIM OF THE REVIEW

Therapeutic effects and systemic mechanism of ZYP in POF were evaluated.

MATERIALS AND METHODS

After pulverization, sieving, and stirring, ZYP was administered intragastrically to cisplatin-induced POF mice at a dose of 1.95 mg/kg/d for 14 days. The anti-POF effects of ZYP were investigated by assessing the number of ovarian follicles at different developmental stages, as well as measuring serum estradiol (E2) levels and ovarian-expressed anti-Müllerian hormone (AMH). Reproductive performance and offspring health were evaluated to predict fertility restoration. Furthermore, a combination of proteomic and metabolomic profiling was employed to elucidate the underlying molecular mechanism of ZYP in treating POF. Western blot (WB) analyses and real-time quantitative polymerase chain reaction (RT-qPCR) were conducted to explore the mechanisms through which ZYP exerted its anti-POF effects.

RESULTS

We have demonstrated that oral administration of ZYP reversed the reduction in follicles at different developmental stages and stimulated the expressions of serum E2 and ovarian-expressed AMH in a cisplatin-induced POF model. Additionally, ZYP ameliorated follicle apoptosis in ovaries affected by cisplatin-induced POF. Furthermore, treatment with ZYP restored the quantity and quality of oocytes, as well as enhanced fertility. Our results revealed 62 differentially expressed proteins (DEPs) through proteomic analyses and identified 26 differentially expressed metabolites (DEMs) through metabolomic analyses. Both DEPs and DEMs were highly enriched in the arachidonic acid (AA) metabolism pathway. ZYP treatment effectively upregulated the protein and mRNA expression of critical targets in AA metabolism and the AKT pathway, including CYP17α1, HSD3β1, LHR, STAR, and AKT, in cisplatin-induced POF mice.

CONCLUSIONS

These results indicated that ZYP exerted protective effects against POF and restored fertility from cisplatin-induced apoptosis. ZYP could be a satisfying alternative treating POF.

Subacute high-refined carbohydrate diet leads to abnormal reproductive control of the hypothalamic-pituitary axis in female rats

We previously reported that female rats placed on a diet containing refined carbohydrates (HCD) resulted in obesity and reproductive abnormalities, such as high serum LH concentration and abnormal ovarian function. However, the impacts at the hypothalamic-pituitary (HP) function, specifically regarding pathways linked to reproductive axis modulation are unknown. In this study, we assessed whether subacute feeding with HCD results in abnormal reproductive control in the HP axis. Female rats were fed with HCD for 15 days and reproductive HP axis morphophysiology was assessed. HCD reduced hypothalamic mRNA expression (Kiss1, Lepr, and Amhr2) and increased pituitary LHβ+ cells. These changes likely contribute to the increase in serum LH concentration observed in HCD. Blunted estrogen negative feedback was observed in HCD, with increased kisspeptin protein expression in the arcuate nucleus of the hypothalamus (ARH), lower LHβ+ cells and LH concentration in ovariectomized (OVX)+HCD rats. Thus, these data suggest that HCD feeding led to female abnormal reproductive control of HP axis.

Chronic exposure to a mixture of phthalates shifts the white and brown adipose tissue phenotypes in female mice

Phthalates are endocrine-disrupting chemicals used in consumer products. Although phthalates are obesogens and affect metabolic function, it is unknown if chronic exposure for 6 months to a phthalate mixture alters adipose tissue phenotype in female mice. After vehicle or mixture exposure, white adipose tissue and brown adipose tissue (WAT and BAT) were analyzed for expression of adipogenesis, proliferation, angiogenesis, apoptosis, oxidative stress, inflammation, and collagen deposition markers. The mixture altered WAT morphology, leading to an increase in hyperplasia, blood vessel number, and expression of BAT markers (Adipoq and Fgf2) in WAT. The mixture increased the expression of the inflammatory markers, Il1β, Ccl2, and Ccl5, in WAT. The mixture also increased expression of the proapoptotic (Bax and Bcl2) and antiapoptotic (Bcl2l10) factors in WAT. The mixture increased expression of the antioxidant Gpx1 in WAT. The mixture changed BAT morphology by increasing adipocyte diameter, whitening area, and blood vessel number and decreased expression of the thermogenic markers Ucp1, Pgargc1a, and Adrb3. Furthermore, the mixture increased the expression of adipogenic markers Plin1 and Cebpa, increased mast cell number, and increased Il1β expression in BAT. The mixture also increased expression of the antioxidant markers Gpx and Nrf2 and the apoptotic marker Casp2 in BAT. Collectively, these data indicate that chronic exposure to a phthalate mixture alters WAT and BAT lipid metabolism phenotypes in female mice, leading to an apparent shift in their normal morphology. Following long-term exposure to a phthalate mixture, WAT presented BAT-like features and BAT presented WAT-like features.

Biochemical mechanisms of tributyltin chloride-induced cell toxicity in Sertoli cells

Tributyltin chloride (TBTCL) is a widely used fungicide and heat stabilizer in compositions of PVC. TBTCL has been detected in human bodies and potentially causes harmful effects on humans' thyroid, cardiovascular and other organs. As one of the first examples of endocrine disruptors, the toxicity effects of TBTCL on the male reproduction system have aroused concerns. However, the potential cellular mechanisms are not fully explored. In the current study, by using Sertoli cells, a critical regulator of spermatogenesis as a cell model, we showed that with 200 nM exposure for 24 h, TBTCL causes apoptosis and cell cycle arrest. RNA sequencing analyses suggested that TBTCL probably activates endoplasmic reticulum (ER) stress, and disrupts autophagy. Biochemical analysis showed that TBTCL indeed induces ER stress and the dysregulation of autophagy. Interestingly, activation of ER stress and inhibition of autophagy is responsible for TBTCL-induced apoptosis and cell cycle arrest. Our results thus uncovered a novel insight into the cellular mechanisms for TBTCL-induced toxicology in Sertoli cells.

Inherited Epigenetic Hallmarks of Childhood Obesity Derived from Prenatal Exposure to Obesogens

Childhood obesity has reached epidemic levels in developed countries and is becoming a major cause for concern in the developing world. The causes of childhood obesity are complex and multifactorial, involving the interaction between individual genetics and environmental and developmental factors. Among the environmental factors, there is a growing interest in understanding the possible relationship between the so-called environmental obesogens and the development of obesity in children. Exposure to these obesogens such as phthalates, bisphenol A, or parabens, has been identified as a promoter of obesity through different mechanisms such as the alteration of adipocyte development from mesenchymal progenitors, the interference with hormone receptors, and induced inflammation. However, less attention has been paid to the inheritance of epigenetic modifications due to maternal exposure to these compounds during pregnancy. Thus, the aim of this review is to summarize the current knowledge of epigenetic modifications due to maternal exposure to those obesogens during pregnancy as well as their potential implication on long-term obesity development in the offspring and transgenerational inheritance of epiphenotypes.

Crosstalk between COVID-19 Infection and Kidney Diseases: A Review on the Metabolomic Approaches

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19, a respiratory disorder. Various organ injuries have been reported in response to this virus, including kidney injury and, in particular, kidney tubular injury. It has been discovered that infection with the virus does not only cause new kidney disease but also increases treatment difficulty and mortality rates in people with kidney diseases. In individuals hospitalized with COVID-19, urinary metabolites from several metabolic pathways are used to distinguish between patients with acute kidney injury (AKI) and those without. This review summarizes the pathogenesis, pathophysiology, treatment strategies, and role of metabolomics in relation to AKI in COVID-19 patients. Metabolomics is likely to play a greater role in predicting outcomes for patients with kidney disease and COVID-19 with varying levels of severity in the near future as data on metabolic profiles expand rapidly. Here, we also discuss the correlation between COVID-19 and kidney diseases and the available metabolomics approaches.

High-refined carbohydrate diet alters different metabolic functions in female rats

A diet containing refined carbohydrate (HCD) caused obesity and white adipose tissue (WAT) abnormalities, but it is unclear if HCD is linked with other metabolic dysfunctions in female models. Thus, we assessed whether HCD results in WAT, pancreas, liver, skeletal muscle (SM) and thyroid (TH) abnormalities in female rats. Female rats were fed with HCD for 15 days and metabolic morphophysiology, inflammation, oxidative stress (OS), and fibrosis markers were assessed. HCD rats presented large adipocytes, hyperleptinemia, and WAT OS. HCD caused irregular glucose metabolism, low insulin levels, and large pancreatic isle. Granulomas, reduced glycogen, and OS were observed in HCD livers. HCD caused hypertrophy and increased in glycogen in SM. HCD caused irregular TH morphophysiology, reduced colloid area and high T3 levels. In all selected tissues, inflammation and fibrosis were observed in HCD rats. Collectively, these data suggest that the HCD impairs metabolic function linked with irregularities in WAT, pancreas, liver, SM and TH in female rats.

The Adipose Tissue at the Crosstalk Between EDCs and Cancer Development

Obesity is a major public health concern at the origin of many pathologies, including cancers. Among them, the incidence of gastro-intestinal tract cancers is significantly increased, as well as the one of hormone-dependent cancers. The metabolic changes caused by overweight mainly with the development of adipose tissue (AT), insulin resistance and chronic inflammation induce hormonal and/or growth factor imbalances, which impact cell proliferation and differentiation. AT is now considered as the main internal source of endocrine disrupting chemicals (EDCs) representing a low level systemic chronic exposure. Some EDCs are non-metabolizable and can accumulate in AT for a long time. We are chronically exposed to low doses of EDCs able to interfere with the endocrine metabolism of the body. Importantly, several EDCs have been involved in the genesis of obesity affecting profoundly the physiology of AT. In parallel, EDCs have been implicated in the development of cancers, in particular hormone-dependent cancers (prostate, testis, breast, endometrium, thyroid). While it is now well established that AT secretes adipocytokines that promote tumor progression, it is less clear whether they can initiate cancer. Therefore, it is important to better understand the effects of EDCs, and to investigate the buffering effect of AT in the context of progression but also initiation of cancer cells using adequate models recommended to uncover and validate these mechanisms for humans. We will review and argument here the potential role of AT as a crosstalk between EDCs and hormone-dependent cancer development, and how to assess it.