ERβ expression in the endothelium ameliorates ischemia/reperfusion-mediated oxidative burst and vascular injury

Chronic CNT Fiber Interface With Median Nerve at Acupoint PC6 for Rat's Myocardial Ischemia Control

Myocardial ischemia is one of the most prevalent cardiovascular diseases, underscoring the need for safer and effective therapeutic approaches. Peripheral nerve stimulation, particularly vagus nerve stimulation has emerged as a promising non-pharmaceutical therapy for managing myocardial ischemia. However, vagus nerve stimulation carries risks, such as off-target effects and adverse cardiac events due to its extensive innervation and mixed afferent/efferent fiber composition. Therefore, it is crucial to explore a safer and more user-friendly peripheral nerve interface. In this work, we developed a novel chronic median nerve interface using carbon nanotube fibers as electrodes to stimulate the median nerve at the acupoint PC6 for myocardial ischemia control. Carbon nanotube fibers exhibited excellent biocompatibility, flexibility, conductivity, and charge storage capacity, making them ideal for reliable and prolonged median nerve stimulation. Our results demonstrated that median nerve stimulation at the acupoint PC6 achieved therapeutic effects comparable to electroacupuncture, including improvement in S-T segment values, LF/HF ratios, cardiac index and cardiac troponin T, while being safer and easier to operate than vagus nerve stimulation. Moreover, median nerve stimulation exhibited superior transient and residual effects compared to electroacupuncture, despite a slower response time. Additionally, histological and fluorescence analyses confirmed the safety of the CNTF-based interface over time. These findings suggested that median nerve stimulation at the acupoint PC6 combined the efficacy of nerve stimulation with the safety of acupuncture, offering a promising approach for myocardial ischemia control, particularly in chronic and repeated treatment scenarios. Further researches are warranted to optimize CNTF properties, elucidate the underlying mechanisms of median nerve stimulation, and explore its potential in clinical applications.

Perinatal hypoxia-mediated neurodevelopment abnormalities in congenital heart disease mouse model

BACKGROUND

Cyanotic congenital heart disease (CHD) in children has been associated with neurodevelopmental abnormalities, although the underlying mechanisms remain largely unknown. Multiple factors are likely involved in this process. This research aims to explore the potential effects of hypoxia and vascular system-derived factors in neurodevelopmental outcomes in offspring.

METHODS

Mouse aorta endothelial cells (MEC) and amygdala neurons were isolated to investigate the effects of hypoxia on pro-inflammatory cytokine release, gene expression, redox balance, mitochondrial function, and epigenetic modifications. A CHD mouse model was established to evaluate the impact of perinatal hypoxia on fetal brain development. Estrogen receptor β (ERβ) expression in endothelial cells was modulated using Tie2-driven lentivirus both in vitro and in vivo study to assess the vascular system's contribution to hypoxia-mediated neurodevelopmental abnormalities.

RESULTS

Hypoxia exposure, along with factors released from MEC, led to altered gene expression, oxidative stress, mitochondrial dysfunction, and epigenetic modifications in amygdala neurons. In the CHD mouse model, perinatal hypoxia resulted in compromised vascular function, altered gene expression, disrupted redox balance in brain tissues, and impaired behavioral outcomes in offspring. Prenatal expression of ERβ in endothelial cells partially ameliorated these neurodevelopmental abnormalities, while prenatal knockdown of ERβ mimicked the effects of perinatal hypoxia.

CONCLUSIONS

Hypoxia, combined with endothelial cell-derived factors, induces epigenetic changes in neurons. In the CHD mouse model, perinatal hypoxia causes vascular dysfunction, altered gene expression, and redox imbalance in brain tissues, leading to behavioral impairments in offspring. Prenatal expression of ERβ in endothelial cells mitigates these effects, suggesting that modulating gene expression in the vascular system during pregnancy could play a protective role against hypoxia-induced neurodevelopmental abnormalities in CHD.

Protective effects of 17-β-estradiol on liver injury: The role of TLR4 signaling pathway and inflammatory response

Liver injury, a major global health issue, stems from various causes such as alcohol consumption, nonalcoholic steatohepatitis, obesity, diabetes, metabolic syndrome, hepatitis, and certain medications. The liver's unique susceptibility to ischemia and hypoxia, coupled with the critical role of the gut-liver axis in inflammation, underscores the need for effective therapeutic interventions. The study highlights E2's interaction with estrogen receptors (ERs) and its modulation of the Toll-like receptor 4 (TLR4) signaling pathway as key mechanisms in mitigating liver injury. Activation of TLR4 leads to the release of pro-inflammatory cytokines and chemokines, exacerbating liver inflammation and injury. E2 down-regulates TLR4 expression, reduces oxidative stress, and inhibits pro-inflammatory cytokines, thereby protecting the liver. Both classic (ERα and ERβ) and non-classic [G protein-coupled estrogen receptor (GPER)] receptors are influenced by E2. ERα is particularly crucial for liver regeneration, preventing liver failure by promoting hepatocyte proliferation. Furthermore, E2 exerts anti-inflammatory, antioxidant, and anti-apoptotic effects by inhibiting cytokines such as IL-6, IL-1β, TNF-α, and IL-17, and by reducing lipid peroxidation and free radical damage. The article calls for further clinical research to validate these findings and to develop estrogen-based treatments for liver injuries. Overall, the research emphasizes the significant potential of E2 as a therapeutic agent for liver injuries. It advocates for extensive clinical studies to validate E2 hepatoprotective properties and develop effective estrogen-based treatments.

Evodiamine suppresses endometriosis development induced by early EBV exposure through inhibition of ERβ

Introduction: Endometriosis (EMS) is characterized as a prevalent gynecological inflammatory disorder marked by the existence of endometrial tissues situated beyond the uterus. This condition leads to persistent pelvic pain and may contribute to infertility. In this investigation, we explored the potential mechanism underlying the development of endometriosis (EMS) triggered by transient exposure to either latent membrane protein 1 (LMP1) or Epstein-Barr virus (EBV) in a mouse model. Additionally, we examined the potential inhibitory effect of evodiamine (EDM) on EMS. Methods: Immortalized human endometrial stromal cells (HESC) or epithelial cells (HEEC) were transiently exposed to either EBV or LMP1. The presence of evodiamine (EDM) was assessed for its impact on estrogen receptor β (ERβ) expression, as well as on cell metabolism parameters such as redox balance, mitochondrial function, inflammation, and proliferation. Additionally, a mixture of LMP1-treated HESC and HEEC was administered intraperitoneally to generate an EMS mouse model. Different dosages of EDM were employed for treatment to evaluate its potential suppressive effect on EMS development. Results: Transient exposure to either EBV or LMP1 triggers persistent ERβ expression through epigenetic modifications, subsequently modulating related cell metabolism for EMS development. Furthermore, 4.0 µM of EDM can efficiently reverse this effect in in vitro cell culture studies. Additionally, 20 mg/kg body weight of EDM treatment can partly suppress EMS development in the in vivo EMS mouse model. Conclusion: Transient EBV/LMP1 exposure triggers permanent ERβ expression, favoring later EMS development, EDM inhibits EMS development through ERβ suppression. This presents a novel mechanism for the development of endometriosis (EMS) in adulthood stemming from early Epstein-Barr virus (EBV) exposure during childhood. Moreover, evodiamine (EDM) stands out as a prospective candidate for treating EMS.

Age and sex mediated effects of estrogen and Β3-adrenergic receptor on cardiovascular pathophysiology

Sex differences are consistently identified in determining the prevalence, manifestation, and response to therapies in several systemic disorders, including those affecting the cardiovascular (CV), skeletal muscle, and nervous system. Interestingly, such differences are often more noticeable as we age. For example, premenopausal women experience a lower risk of CV disease than men of the same age. While at an advanced age, with menopause, the risk of cardiovascular diseases and adverse outcomes increases exponentially in women, exceeding that of men. However, this effect appears to be reversed in diseases such as pulmonary hypertension, where women are up to seven times more likely than men to develop an idiopathic form of the disease with symptoms developing ten years earlier than their male counterparts. Explaining this is a complex question. However, several factors and mechanisms have been identified in recent decades, including a role for sex hormones, particularly estrogens and their related receptors. Furthermore, an emerging role in these sex differences has also been suggested for β-adrenergic receptors (βARs), which are essential regulators of mammalian physiology. It has in fact been shown that βARs interact with estrogen receptors (ER), providing further demonstration of their involvement in determining sexual differences. Based on these premises, this review article focused on the β3AR subtype, which shows important activities in adipose tissue but with new and interesting roles in regulating the function of cardiomyocytes and vascular cells. In detail, we examined how β3AR and ER signaling are intertwined and whether there would be sex- and age-dependent specific effects of these receptor systems.

The active ingredient (DSH-20) of Salvia miltiorrhiza flower reduces oxidative damage and apoptosis in cardiomyocytes by regulating miR-1

BACKGROUND

DSH-20, the active ingredient of Salvia miltiorrhiza flower extract, is used to treat cardiovascular diseases. However, its mechanism of action remains unclear. Herein, we investigated the intervention of DSH-20 in H₂O₂-induced oxidative damage and apoptosis in cardiomyocytes. METHODS AND RESULTS: H₂O₂ was used to induce oxidative damage and apoptosis in H9c2 cardiomyocytes. Based on concentration gradient studies, we found that 62.5 µg/mL DSH-20 significantly reduced reactive oxygen species and lactate dehydrogenase levels and increased superoxide dismutase levels. DSH-20 also alleviated the apoptosis rate, the changes in mRNA of apoptosis-related genes (Bcl-2, BAX, and Caspase-3) and miR-1 expression. Moreover, transfection of miR-1 mimics aggravated oxidative damage and apoptosis, whereas DSH-20 alleviated these effects.

CONCLUSIONS

DSH-20 reduced H₂O₂-induced oxidative damage and apoptosis in H9c2 cardiomyocytes likely by downregulating miR-1 expression.

Maternal diabetes-mediated RORA suppression contributes to gastrointestinal symptoms in autism-like mouse offspring

BACKGROUND

Retinoic acid-related orphan receptor alpha (RORA) has been reported to be suppressed in autistic patients and is associated with autism spectrum disorders (ASD), although the potential role and mechanism of RORA on gastrointestinal (GI) symptoms in ASD patients is still not reported. In this study, we aim to investigate the contribution of RORA to GI symptoms through a maternal diabetes-mediated autism-like mouse model.

RESULTS

Male offspring of diabetic dams were treated with either superoxide dismutase (SOD) mimetic MnTBAP or RORA agonist SR1078, or were crossbred with intestine epithelial cells (IEC)-specific RORA knockout (RORA-/-) mouse. Gene expression, oxidative stress and inflammation were measured in brain tissues, peripheral blood mononuclear cells (PBMC) and IEC, and GI symptoms were evaluated. Our results showed that SOD mimetic MnTBAP completely, while RORA agonist SR1078 partly, reversed maternal diabetes-mediated oxidative stress and inflammation in the brain, PBMC and IEC, as well as GI symptoms, including intestine permeability and altered gut microbiota compositions. IEC-specific RORA deficiency either mimicked or worsened maternal diabetes-mediated GI symptoms as well as oxidative stress and inflammation in IEC, while there was little effect on maternal diabetes-mediated autism-like behaviors.

CONCLUSIONS

We conclude that RORA suppression contributes to maternal diabetes-mediated GI symptoms in autism-like mouse offspring, this study provides a potential therapeutical target for maternal diabetes-mediated GI symptoms in offspring through RORA activation.

Xenoestrogens impact brain estrogen receptor signaling during the female lifespan: A precursor to neurological disease?

Xenoestrogens, foreign synthetic chemicals mimicking estrogens, are lurking in our surroundings. Climate change may alter their toxicity and bioavailability. Since xenoestrogens have extremely high lipid solubility and are structurally similar to natural endogenous estrogens, they can bind to estrogen receptors (ERs) -alpha (ER-α) and -beta (ER-β). Scientific evidence accumulated over the past decades have suggested that natural 17β-estradiol (E2; a potent estrogen), via activation of its receptors, plays a pivotal role in regulation of brain development, differentiation, metabolism, synaptic plasticity, neuroprotection, cognition, anxiety, body temperature, feeding and sexual behavior. In the brain, ER-β is predominantly expressed in the various regions, including cerebral cortex and hippocampus, that have been shown to play a key role in cognition. Therefore, disturbances in function of ER-β mediated E2 signaling by xenoestrogens can lead to deleterious effects that potentiate a variety of neurological diseases starting from prenatal to post-menopause in women. The goal of this review is to identify the possible neurological effects of xenoestrogens that can alter estrogen receptor-mediated signaling in the brain during different stages of the female lifespan.

Estrogen alleviates hepatocyte necroptosis depending on GPER in hepatic ischemia reperfusion injury

Hepatic ischemia reperfusion injury (IRI) occurs in liver transplantation, complex liver resection, and hemorrhagic shock, which causes donor organ shortage and hepatic damage. The burst of reactive oxygen species (ROS) during reperfusion leads to cell apoptosis and necroptosis. It has been reported that estrogen could attenuate hepatic IRI. G protein estrogen receptor (GPER) mediates estrogen effects via nonclassic receptor systems. Here, we investigate whether estrogen protecting liver from hepatic IRI depends on GPER and the influence of GPER activation on hepatocyte necroptosis. We proved that estrogen had a protective effect on both hepatocyte hypoxia re-oxygen (H/R) challenge and mouse hepatic ischemia reperfusion model. However, the application of GPER specific antagonist G15 before estrogen inhibited this beneficial effect. The results of mitochondria functional measurement revealed that estrogen improved hepatocyte mitochondria function by activating GPER, which might benefit from the increased expression of connexin 43 (Cx43) in mitochondria. To investigate the relationship between GPER activation and necroptosis, we used caspase-3/7 inhibitor benzyloxycarbonyl-Asp(OMe)-Glu(OMe)-Val-Asp(OMe)-chloromethylketone (Z-DEVD-FMK) to eliminate the interference of apoptosis. Estrogen showed a protective effect on hepatic IRI after using Z-DEVD-FMK, which could be suppressed by G15. GPER activation decreased the level of receptor interacting protein kinase (RIPK) 3, phosphorylated (p-) RIPK1, and p-mixed lineage kinase domain-like (MLKL). The co-immunoprecipitation result indicated that GPER could bind with RIPK3. GPER is indispensable in estrogen protecting liver from IRI. GPER activation attenuates hepatocyte necroptosis by decreasing the level of RIPK3, p-RIPK1, and p-MLKL.

Pterostilbene accelerates wound healing by modulating diabetes-induced estrogen receptor β suppression in hematopoietic stem cells

Background

Delayed wound healing is one of the major complications of diabetes mellitus and is characterized by prolonged inflammation, delayed re-epithelialization and consistent oxidative stress, although the detailed mechanism remains unknown. In this study, we aimed to investigate the potential role and effect of pterostilbene (PTE) and hematopoietic stem cells (HSCs) on diabetic wound healing.

Methods

Diabetic rats were used to measure the epigenetic changes in both HSCs and peripheral blood mononuclear cells (PBMCs). A cutaneous burn injury was induced in the rats and PTE-treated diabetic HSCs were transplanted for evaluation of wound healing. In addition, several biomedical parameters, including gene expression, oxidative stress, mitochondrial function and inflammation in macrophages, were also measured.

Results

Our data showed that PTE had a much stronger effect than resveratrol on accelerating diabetic wound healing, likely because PTE can ameliorate diabetes-induced epigenetic changes to estrogen receptor β promoter in HSCs, while resveratrol cannot. Further investigation showed that bone marrow transplantation of PTE-treated diabetic HSCs restores diabetes-induced suppression of estrogen receptor β and its target genes, including nuclear respiratory factor-1 and superoxide dismutase 2, and protects against diabetes-induced oxidative stress, mitochondrial dysfunction and elevated pro-inflammatory cytokines in both PBMCs and macrophages, subsequently accelerating cutaneous wound healing.

Conclusions

HSC may play an important role in wound healing through transferring epigenetic modifications to subsequent PBMCs and macrophages by differentiation, while PTE accelerates diabetic wound healing by modulating diabetes-induced epigenetic changes in HSCs. Thus, PTE may be a novel therapeutic strategy for diabetic wound healing.

Estrogen Receptors: Therapeutic Perspectives for the Treatment of Cardiac Dysfunction after Myocardial Infarction

Estrogen receptors (ER) mediate functions beyond their endocrine roles, as modulation of cardiovascular, renal, and immune systems through anti-inflammatory and anti-apoptotic effects, preventing necrosis of cardiomyocytes and endothelial cells, and attenuating cardiac hypertrophy. Estradiol (E2) prevents cardiac dysfunction, increases nitric oxide synthesis, and reduces the proliferation of vascular cells, yielding protective effects, regardless of gender. Such actions are mediated by ER (ER-alpha (ERα), ER-beta (ERβ), or G protein-coupled ER (GPER)) through genomic or non-genomic pathways, which regulate cardiovascular function and prevent tissue remodeling. Despite the extensive knowledge on the cardioprotective effects of estrogen, clinical studies conducted on myocardial infarction (MI) and cardiovascular diseases still include favorable and unfavorable profiles. The purpose of this review is to provide up-to-date information regarding molecular, preclinical, and clinical aspects of cardiovascular E2 effects and ER modulation as a potential therapeutic target for the treatment of MI-induced cardiac dysfunction.

Estrogen-Mediated Gaseous Signaling Molecules in Cardiovascular Disease

Gender difference is well recognized as a key risk factor for cardiovascular disease (CVD). Estrogen, the primary female sex hormone, improves cardiovascular functions through receptor (ERα, ERβ, or G protein-coupled estrogen receptor)-initiated genomic or non-genomic mechanisms. Gaseous signaling molecules, including nitric oxide (NO), hydrogen sulfide (H₂S), and carbon monoxide (CO), are important regulators of cardiovascular function. Recent studies have demonstrated that estrogen regulates the production of these signaling molecules in cardiovascular cells to exert its cardiovascular protective effects. We discuss current understanding of gaseous signaling molecules in cardiovascular disease (CVD), the underlying mechanisms through which estrogen exerts cardiovascular protective effects by regulating these molecules, and how these findings can be translated to improve the health of postmenopausal women.

Betulinic Acid Inhibits Endometriosis Through Suppression of Estrogen Receptor β Signaling Pathway

Endometriosis is an inflammatory gynecological disorder characterized by endometrial tissue growth located outside of the uterine cavity in addition to chronic pelvic pain and infertility. In this study, we aim to develop a potential therapeutic treatment based on the pathogenesis and mechanism of Endometriosis. Our preliminary data showed that the expression of estrogen receptor β (ERβ) was significantly increased, while ERα was significantly decreased, in endometriotic cells compared to normal endometrial cells. Further investigation showed that betulinic acid (BA) treatment suppressed ERβ expression through epigenetic modification on the ERβ promoter, while had no effect on ERα expression. In addition, BA treatment suppresses ERβ target genes, including superoxide dismutase 2 (SOD2), nuclear respiratory factor-1 (NRF1), cyclooxygenase 2 (COX2), and matrix metalloproteinase-1 (MMP1), subsequently increasing oxidative stress, triggering mitochondrial dysfunction, decreasing elevated proinflammatory cytokines, and eventually suppressing endometriotic cell proliferation, mimicking the effect of ERβ knockdown. On the other hand, gain of ERβ by lentivirus infection in normal endometrial cells resulted in increased cell proliferation and proinflammatory cytokine release, while BA treatment diminished this effect through ERβ suppression with subsequent oxidative stress and apoptosis. Our results indicate that ERβ may be a major driving force for the development of endometriosis, while BA inhibits Endometriosis through specific suppression of the ERβ signaling pathway. This study provides a novel therapeutic strategy for endometriosis treatment through BA-mediated ERβ suppression.

Estrogen-mediated protection against coronary heart disease: The role of the Notch pathway

Estrogen regulates a plethora of biological processes, under physiological and pathological conditions, by affecting key pathways involved in the regulation of cell proliferation, fate, survival and metabolism. The Notch receptors are mediators of communication between adjacent cells and are key determinants of cell fate during development and in postnatal life. Crosstalk between estrogen and the Notch pathway intervenes in many processes underlying the development and maintenance of the cardiovascular system. The identification of molecular mechanisms underlying the interaction between these types of endocrine and juxtacrine signaling are leading to a deeper understanding of physiological conditions regulated by these steroid hormones and, potentially, to novel therapeutic approaches to prevent pathologies linked to reduced levels of estrogen, such as coronary heart disease, and cardiotoxicity caused by hormone therapy for estrogen-receptor-positive breast cancer.

ERβ Accelerates Diabetic Wound Healing by Ameliorating Hyperglycemia-Induced Persistent Oxidative Stress

Delayed wound healing in diabetic patients is a serious diabetic complication, resulting in major health problems as well as high mortality and disability. The detailed mechanism still needs to be fully understood. In this study, we aim to investigate potential mechanisms and explore an efficient strategy for clinical treatment of diabetic wound healing. Human umbilical endothelial cells were exposed to hyperglycemia for 4 days, then switched to normoglycemia for an additional 4 days. The cells were harvested for the analysis of reactive oxygen species (ROS) generation, gene expression and VEGF signaling pathway. Furthermore, the diabetic wound model was established in rats for the evaluation of wound healing rates under the treatment of either ERβ agonist/antagonist or SOD mimetic MnTBAP. Our results show that transient hyperglycemia exposure results in persistent ROS overgeneration after the switch to normoglycemia, along with suppressed expression of ERβ, SOD2, and the VEGF signaling pathway. Either ERβ expression or activation diminishes ROS generation. In vivo experiments with diabetic rats show that ERβ activation or SOD mimetic MnTBAP diminishes ROS generation in tissues and accelerates diabetic wound healing. Transient hyperglycemia exposure induces ROS generation and suppresses ERβ expression, subsequently resulting in SOD2 suppression with additional elevated ROS generation. This forms a positive-feed forward loop for ROS generation with persistent oxidative stress. ERβ expression or activation breaks this loop and ameliorates this effect, thereby accelerating diabetic wound healing. We conclude that ERβ accelerates diabetic wound healing by ameliorating hyperglycemia-induced persistent oxidative stress. This provides a new strategy for clinical treatment of diabetic wound healing based on ERβ activation.

Resveratrol ameliorates prenatal progestin exposure-induced autism-like behavior through ERβ activation

Background

Recent literatures indicate that maternal hormone exposure is a risk factor for autism spectrum disorder (ASD). We hypothesize that prenatal progestin exposure may counteract the neuroprotective effect of estrogen and contribute to ASD development, and we aim to develop a method to ameliorate prenatal progestin exposure-induced autism-like behavior.

Methods

Experiment 1: Prenatal progestin exposure-induced offspring are treated with resveratrol (RSV) through either prenatal or postnatal exposure and then used for autism-like behavior testing and other biomedical analyses. Experiment 2: Prenatal norethindrone (NET) exposure-induced offspring are treated with ERβ knockdown lentivirus together with RSV for further testing. Experiment 3: Pregnant dams are treated with prenatal NET exposure together with RSV, and the offspring are used for further testing.

Results

Eight kinds of clinically relevant progestins were used for prenatal exposure in pregnant dams, and the offspring showed decreased ERβ expression in the amygdala with autism-like behavior. Oral administration of either postnatal or prenatal RSV treatment significantly reversed this effect with ERβ activation and ameliorated autism-like behavior. Further investigation showed that RSV activates ERβ and its target genes by demethylation of DNA and histone on the ERβ promoter, and then minimizes progestin-induced oxidative stress as well as the dysfunction of mitochondria and lipid metabolism in the brain, subsequently ameliorating autism-like behavior.

Conclusions

We conclude that resveratrol ameliorates prenatal progestin exposure-induced autism-like behavior through ERβ activation. Our data suggest that prenatal progestin exposure is a strong risk factor for autism-like behavior. Many potential clinical progestin applications, including oral contraceptive pills, preterm birth drugs, and progestin-contaminated drinking water or seafood, may be risk factors for ASD. In addition, RSV may be a good candidate for clinically rescuing or preventing ASD symptoms in humans, while high doses of resveratrol used in the animals may be a potential limitation for human application.

Estrogen-dependent efficacy of limb ischemic preconditioning in female rats

Our aim was to examine the effects of ischemic preconditioning (IPC) on the local periosteal and systemic inflammatory consequences of hindlimb ischemia-reperfusion (IR) in Sprague-Dawley rats with chronic estrogen deficiency (13 weeks after ovariectomy, OVX) in the presence and absence of chronic 17beta-estradiol supplementation (E2, 20 µg kg^-1 , 5 days/week for 5 weeks); sham-operated (non-OVX) animals served as controls. As assessed by intravital fluorescence microscopy, rolling and the firm adhesion of polymorphonuclear neutrophil leukocytes (PMNs) gave similar results in the Sham + IR and OVX + IR groups in the tibial periosteal microcirculation during the 3-h reperfusion period after a 60-min tourniquet ischemia. Postischemic increases in periosteal PMN adhesion and PMN-derived adhesion molecule CD11b expressions, however, were significantly reduced by IPC (two cycles of 10'/10') in Sham animals, but not in OVX animals; neither plasma free radical levels (as measured by chemiluminescence), nor TNF-alpha release was affected by IPC. E2 supplementation in OVX animals restored the IPC-related microcirculatory integrity and PMN-derived CD11b levels, and TNF-alpha and free radical levels were reduced by IPC only with E2. An enhanced estrogen receptor beta expression could also be demonstrated after E2 in the periosteum. Overall, the beneficial periosteal microcirculatory effects of limb IPC are lost in chronic estrogen deficiency, but they can be restored by E2 supplementation. This suggests that the presence of endogenous estrogen is a necessary facilitating factor of the anti-inflammatory protection provided by limb IPC in females. The IPC-independent effects of E2 on inflammatory reactions should also be taken into account in this model. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:97-105, 2018.

Prenatal Progestin Exposure Is Associated With Autism Spectrum Disorders

We have previously reported that prenatal progestin exposure induces autism-like behavior in offspring through ERβ (estrogen receptor β) suppression in the brain, indicating that progestin may induce autism spectrum disorders (ASD). In this study, we aim to investigate whether prenatal progestin exposure is associated with ASD. A population-based case-control epidemiology study was conducted in Hainan province of China. The ASD children were first screened with the Autism Behavior Checklist (ABC) questionnaire, and then diagnosed by clinical professionals using the ASD diagnosis criteria found in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V). Eventually, 235 cases were identified as ASD from 37863 children aged 0-6 years old, and 682 matched control subjects with typically developing children were selected for the analysis of potential impact factors on ASD prevalence using multivariate logistic regression. Our data show that the ASD prevalence rate in Hainan was 0.62% with a boy:girl ratio of 5.4:1. Interestingly, we found that the following factors were strongly associated with ASD prevalence: use of progestin to prevent threatened abortion, use of progestin contraceptives at the time of conception, and prenatal consumption of progestin-contaminated seafood during the first trimester of pregnancy. All the above factors were directly or indirectly involved with prenatal progestin exposure. Additionally, we conducted in vivo experiments in rats to further confirm our findings. Either endogenous (progesterone) or synthetic progestin (norethindrone)-treated seafood zebrafish were used to feed pregnant dams, and the subsequent offspring showed autism-like behavior, which further demonstrated that prenatal progestin exposure may induce ASD. We conclude that prenatal progestin exposure may be associated with ASD development.

Prenatal levonorgestrel exposure induces autism-like behavior in offspring through ERβ suppression in the amygdala

BACKGROUND

Autism spectrum disorder (ASD) is characterized by impairments in social communication and restricted or repetitive behaviors or interests. ASD is now diagnosed in more than one out of 100 children and is biased towards males by a ratio of at least 4:1. Many possible explanations and potential causative factors have been reported, such as genetics, sex, and environmental factors, although the detailed mechanisms of ASD remain unclear.

METHODS

The dams were exposed through oral contraceptives to either vehicle control (VEH) alone, levonorgestrel (LNG) alone, ethinyl estradiol (EE) alone, or a combination of LNG/EE for 21 days during their pregnancy. The subsequent 10-week-old offspring were used for autism-like behavior testing, and the limbic tissues were isolated for analysis. In another experimental group, 8-week-old male offspring were treated by infusion of ERβ overexpression/knockdown lentivirus in the amygdala, and the offspring were analyzed after 2 weeks.

RESULTS

We show that prenatal exposure of either LNG alone or a LNG/EE combination, but not EE alone, results in suppression of ERβ (estrogen receptor β) and its target genes in the amygdala with autism-like behavior in male offspring, while there is a much smaller effect on female offspring. However, we find that there is no effect on the hippocampus and hypothalamus. Further investigation shows that ERβ suppression is due to LNG-mediated altered methylation on the ERβ promoter and results in tissue damage with oxidative stress and the dysfunction of mitochondria and fatty acid metabolism, which subsequently triggers autism-like behavior. Overexpression of ERβ in the amygdala completely restores LNG-induced ERβ suppression and autism-like behaviors in offspring, while ERβ knockdown mimics this effect, indicating that ERβ expression in the amygdala plays an important role in autism-like behavior development.

CONCLUSIONS

We conclude that prenatal levonorgestrel exposure induces autism-like behavior in offspring through ERβ suppression in the amygdala. To our knowledge, this is the first time the potential effect of oral contraceptives on the contribution of autism-like behavior in offspring has been discovered.

Perinatal testosterone exposure potentiates vascular dysfunction by ERβ suppression in endothelial progenitor cells

Recent clinical cohort study shows that testosterone therapy increases cardiovascular diseases in men with low testosterone levels, excessive circulating androgen levels may play a detrimental role in the vascular system, while the potential mechanism and effect of testosterone exposure on the vascular function in offspring is still unknown. Our preliminary results showed that perinatal testosterone exposure in mice induces estrogen receptor β (ERβ) suppression in endothelial progenitor cells (EPCs) in offspring but not mothers, while estradiol (E2) had no effect. Further investigation showed that ERβ suppression is due to perinatal testosterone exposure-induced epigenetic changes with altered DNA methylation on the ERβ promoter. During aging, EPCs with ERβ suppression mobilize to the vascular wall, differentiate into ERβ-suppressed mouse endothelial cells (MECs) with downregulated expression of SOD2 (mitochondrial superoxide dismutase) and ERRα (estrogen-related receptor α). This results in reactive oxygen species (ROS) generation and DNA damage, and the dysfunction of mitochondria and fatty acid metabolism, subsequently potentiating vascular dysfunction. Bone marrow transplantation of EPCs that overexpressed with either ERβ or a SIRT1 single mutant SIRT1-C152(D) that could modulate SIRT1 phosphorylation significantly ameliorated vascular dysfunction, while ERβ knockdown worsened the problem. We conclude that perinatal testosterone exposure potentiates vascular dysfunction through ERβ suppression in EPCs.

Non-nuclear estrogen receptor alpha activation in endothelium reduces cardiac ischemia-reperfusion injury in mice

Steroid hormone receptors including estrogen receptors (ER) classically function as ligand-regulated transcription factors. However, estrogens also elicit cellular effects through binding to extra-nuclear ER (ERα, ERβ, and G protein-coupled ER or GPER) that are coupled to kinases. How extra-nuclear ER actions impact cardiac ischemia-reperfusion (I/R) injury is unknown. We treated ovariectomized wild-type female mice with estradiol or an estrogen-dendrimer conjugate (EDC), which selectively activates extra-nuclear ER, or vehicle interventions for two weeks. I/R injury was then evaluated in isolated Langendorff perfused hearts. Two weeks of treatment with estradiol significantly decreased infarct size and improved post-ischemic contractile function. Similarly, EDC treatment significantly decreased infarct size and increased post-ischemic functional recovery compared to vehicle-treated hearts. EDC also caused an increase in myocardial protein S-nitrosylation, consistent with previous studies showing a role for this post-translational modification in cardioprotection. In further support of a role for S-nitrosylation, inhibition of nitric oxide synthase, but not soluble guanylyl cyclase blocked the EDC mediated protection. The administration of ICI182,780, which is an agonist of G-protein coupled estrogen receptor (GPER) and an antagonist of ERα and ERβ, did not result in protection; however, ICI182,780 significantly blocked EDC-mediated cardioprotection, indicating participation of ERα and/or ERβ. In studies determining the specific ER subtype and cellular target involved, EDC decreased infarct size and improved functional recovery in mice lacking ERα in cardiomyocytes. In contrast, protection was lost in mice deficient in endothelial cell ERα. Thus, extra-nuclear ERα activation in endothelium reduces cardiac I/R injury in mice, and this likely entails increased protein S-nitrosylation. Since EDC does not stimulate uterine growth, in the clinical setting EDC-like compounds may provide myocardial protection without undesired uterotrophic and cancer-promoting effects.

SIRT1-mediated ERβ suppression in the endothelium contributes to vascular aging

SIRT1 has many important molecular functions in aging, and the estrogen receptors (ERs) have a vasculoprotective effect, although the detailed mechanism for the roles of SIRT1 and ERs in vascular aging remains unclear. We found that ERβ expression in the endothelium was reduced in aging mice, and the expression of ERα and SIRT1 did not change, while SIRT1 activity declined. Further investigation showed that the ERβ expression was regulated by SIRT1 through complexes of SIRT1‐PPARγ/RXR‐p300 that bind to a PPRE (PPAR response element) site on the ERβ promoter, and the declined SIRT1 function in aging mice was due to compromised phosphorylation at S154. A single‐mutant SIRT1‐C152(D) restored the reduced ERβ expression in the endothelium with minimized reactive oxygen species generation and DNA damage and increased mitochondrial function and fatty acid metabolism. In high‐fat diet aging mice, the endothelium‐specific delivery of ERβ or SIRT1‐C152(D) on the vascular wall reduced the circulating lipids with ameliorated vascular damage, including the restored vessel tension and blood pressure. We conclude that SIRT1‐mediated ERβ suppression in the endothelium contributes to vascular aging, and the modulation of SIRT1 phosphorylation through a single‐mutant SIRT1‐C152(D) restores this effect.