Cardioprotective and anti-inflammatory effects of G-protein coupled receptor 30 (GPR30) on postmenopausal type 2 diabetic rats

GPR30 selective agonist G-1 induced insulin resistance in ovariectomized mice on high fat diet and its mechanism

BACKGROUND

Previous in vivo and in vitro studies have demonstrated that estrogen receptor agonist G-1 regulates glucose and lipid metabolism. This study focused on the effects of G-1 on cardiometabolic syndrome and anti-obesity under a high fat diet (HFD).

METHODS

Bilateral ovariectomized female mice were fed an HFD for 6 weeks, and treated them with G-1. A cardiomyocyte insulin resistance model was used to simulate the in vivo environment. The main outcome measures were blood glucose, body weight, and serum insulin levels to assess insulin resistance, while cardiac function and degree of fibrosis were assessed by cardiac ultrasound and pathological observations. We also examined the expression of p-AMPK, p-AKT, and GLUT4 in mice hearts and in vitro models to explore the mechanism by which G-1 regulates insulin signaling.

RESULTS

G-1 reduced body weight in mice on an HFD, but simultaneously increased blood glucose and promoted insulin resistance, resulting in myocardial damage. This damage included disordered cardiomyocytes, massive accumulation of glycogen, extensive fibrosis of the heart, and thickening of the front and rear walls of the left ventricle. At the molecular level, G-1 enhances gluconeogenesis and promotes glucose production by increasing the activity of pyruvate carboxylase (PC) while inhibiting GLUT4 translocation via the AMPK/TBC1D1 pathway, thereby limiting glucose uptake.

CONCLUSION

Despite G-1's the potential efficacy in weight reduction, the concomitant induction of insulin resistance and cardiac impairment in conjunction with an HFD raises significant concerns. Therefore, comprehensive studies of its safety profile and effects under specific conditions are essential prior to clinical use.

Sex-specific epigenetics drive low GPER expression in gastrointestinal smooth muscles in type 2 diabetic mice

Type 2 diabetes mellitus (T2D) causes gastroparesis, delayed intestinal transit, and constipation, for unknown reasons. Complications are predominant in women than men (particularly pregnant and postmenopausal women), suggesting a female hormone-mediated mechanism. Low G-protein coupled estrogen receptor (GPER) expression from epigenetic modifications may explain it. We explored sexually differentiated GPER expression and gastrointestinal symptoms related to GPER alterations in wild-type (WT) and T2D mice (db/db). We also created smooth muscle-specific GPER knockout (GPER KO) mice to phenotypically explore the effect of GPER deficiency on gastrointestinal motility. GPER mRNA and protein expression, DNA methylation and histone modifications were measured from stomach and colon samples of db/db and WT mice. Changes in gut motility were also evaluated as daily fecal pellet production patterns. We found that WT female tissues have the highest GPER mRNA and protein expressions. The expression is lowest in all db/db. GPER downregulation is associated with promoter hypermethylation and reduced enrichment of H3K4me3 and H3K27ac marks around the GPER promoter. We also observed sex-specific disparities in fecal pellet production patterns of the GPER KO mice compared to WT. We thus, conclude that T2D impairs gut GPER expression, and epigenetic sex-specific mechanisms matter in the downregulation.

The nongenomic neuroprotective effects of estrogen, E2-BSA, and G1 following traumatic brain injury: PI3K/Akt and histopathological study

OBJECTIVES

Studies suggest that both genomic and nongenomic pathways are involved in mediating the salutary effects of steroids following traumatic brain injury (TBI). This study investigated the nongenomic effects of 17β-estradiol (E2) mediated by the PI3K/p-Akt pathway after TBI.

METHODS

Ovariectomized rats were apportioned to E2, E2-BSA (E2 conjugated to bovine serum albumin), G1 [G-protein-coupled estrogen receptor agonist (GPER)] or their vehicle was injected following TBI, whereas ICI (classical estrogen receptor antagonist), G15 (GPER antagonist), ICI + G15, and their vehicles were injected before the induction of TBI and injection of drugs. Diffuse TBI was induced by the Marmarou model. Evans blue (EBC, 5 h), brain water contents (BWC), histopathological changes, and brain PI3K and p-Akt protein expressions were measured 24 h after TBI. The veterinary comma scale (VCS) was assessed before and at different times after TBI.

RESULTS

The results showed a reduction in BWC and EBC and increased VCS in the E2, E2-BSA, and G1 groups. Also, E2, E2-BSA, and G1 reduced brain edema, inflammation, and apoptosis. The ICI and G15 inhibited the beneficial effects of E2, E2-BSA, and G1 on these parameters. All drugs, following TBI, prevented the reduction of brain PI3K/p-Akt expression. The individual or combined use of ICI and G15 eliminated the beneficial effects of E2, E2-BSA, and G1 on PI3K/p-Akt expressions.

CONCLUSIONS

These findings indicated that PI3K/p-Akt pathway plays a critical role in mediating the salutary effects of estradiol on histopathological changes and neurological outcomes following TBI, suggesting that GPER and classic ERs are involved in regulating the expression of PI3K/p-Akt.

Evaluating the neuroprotective effects of progesterone receptors on experimental traumatic brain injury: The PI3K/Akt pathway

BACKGROUND

Studies have confirmed the salutary effects of progesterone (P4) on traumatic brain injury (TBI). This study investigated the beneficial effects of P4 via its receptors on TBI, and also whether progesterone receptors (PRs) can modulate TBI through PI3K/Akt pathway.

MATERIAL AND METHODS

Marmarou method was utilized to induce diffuse TBI in ovariectomized rats. P4 (1.7 mg/kg) or the vehicle (oil) was administered 30 min after TBI induction. Moreover, RU486 (PR antagonist) and its vehicle (DMSO) were injected before TBI induction and P4 injection. Brain Evans blue content, brain water content (WC), various oxidative stress parameters, IL-1β levels, tumor necrosis factor-α (TNF-α), histopathological alterations, and also phosphorylated Akt (p-Akt) and PI3K expressions in the brain were assessed 24 h after TBI. The veterinary comma scale (VCS) was measured before and after TBI at different times.

RESULTS

The findings revealed that P4 caused an increase in VCS and a decrease in brain WC, oxidative stress, TNF-α and IL-1β levels. RU486 inhibited the beneficial effects of P4 on these indices. Moreover, RU486 prevented the reduction of brain edema, inflammation, and apoptosis caused by P4. Moreover, P4 following TBI increased the expression of PI3K/p-Akt protein in the brain. RU486 eliminated the effects of P4 on PI3K/p-Akt expression.

CONCLUSION

According to these findings, PRs are acting as critical mediators for the neuroprotective properties of P4 on oxidative stress, pro-inflammatory cytokine levels, and neurological outcomes. PRs also play an important role in regulating the PI3K/p-Akt expression and nongenomic function of P4.

The Role of Inhaled Estradiol and Myrtenol, Alone and in Combination, in Modulating Behavioral and Functional Outcomes Following Traumatic Experimental Brain Injury: Hemodynamic, Molecular, Histological and Behavioral Study

BACKGROUND

Traumatic brain injury (TBI) is an important and growing cause of disability worldwide, and its cognitive consequences may be particularly significant. This study assessed the neuroprotective impacts of estradiol (E2), myrtenol (Myr), and the combination of the two on the neurological outcome, hemodynamic parameters, learning and memory, brain-derived neurotrophic factor (BDNF) level, phosphoinositide 3-kinases (PI3K/AKT) signaling, and inflammatory and oxidative factors in the hippocampus after TBI.

METHODS

Eighty-four adult male Wistar rats were randomly divided into 12 groups with seven rats in each (six groups to measure intracranial pressure, cerebral perfusion pressure, brain water content, and veterinary coma scale, and six groups for behavioral and molecular studies): sham, TBI, TBI/vehicle, TBI/Myr, TBI/E2, and TBI/Myr + E2 (Myr 50 mg/kg and E2 33.3 μg/kg via inhalation for 30 min after TBI induction). Brain injury was induced by using Marmarou's method. Briefly, a 300-g weight was dropped down from a 2-m height through a free-falling tube onto the head of the anesthetized animals.

RESULTS

Veterinary coma scale, learning and memory, brain water content, intracranial pressure, and cerebral perfusion pressure were impaired following TBI, and inflammation and oxidative stress were raised in the hippocampus after TBI. The BDNF level and PI3K/AKT signaling were impaired due to TBI. Inhalation of Myr and E2 had protective effects against all negative consequences of TBI by decreasing brain edema and the hippocampal content of inflammatory and oxidant factors and also by improving BDNF and PI3K/AKT in the hippocampus. Based on these data, there were no differences between alone and combination administrations.

CONCLUSIONS

Our results propose that Myr and E2 have neuroprotective effects on cognition impairments due to TBI.

The G protein-coupled oestrogen receptor GPER in health and disease: an update

Oestrogens and their receptors contribute broadly to physiology and diseases. In premenopausal women, endogenous oestrogens protect against cardiovascular, metabolic and neurological diseases and are involved in hormone-sensitive cancers such as breast cancer. Oestrogens and oestrogen mimetics mediate their effects via the cytosolic and nuclear receptors oestrogen receptor-α (ERα) and oestrogen receptor-β (ERβ) and membrane subpopulations as well as the 7-transmembrane G protein-coupled oestrogen receptor (GPER). GPER, which dates back more than 450 million years in evolution, mediates both rapid signalling and transcriptional regulation. Oestrogen mimetics (such as phytooestrogens and xenooestrogens including endocrine disruptors) and licensed drugs such as selective oestrogen receptor modulators (SERMs) and downregulators (SERDs) also modulate oestrogen receptor activity in both health and disease. Following up on our previous Review of 2011, we herein summarize the progress made in the field of GPER research over the past decade. We will review molecular, cellular and pharmacological aspects of GPER signalling and function, its contribution to physiology, health and disease, and the potential of GPER to serve as a therapeutic target and prognostic indicator of numerous diseases. We also discuss the first clinical trial evaluating a GPER-selective drug and the opportunity of repurposing licensed drugs for the targeting of GPER in clinical medicine.

The effects of G protein-coupled receptor 30 (GPR30) on cardiac glucose metabolism in diabetic ovariectomized female rats

BACKGROUND

Diabetic cardiometabolic disorders are characterized by significant changes in cardiac metabolism and are increased in postmenopausal women, which emphasize the role of 17β-estradiol (E2). Despite this, there are few safe and effective pharmacological treatments for these disorders. The role of G protein-coupled estrogen receptor (GPR30), which mediates the non-genomic effects of E2, is mostly unexplored.

METHODS

In this study, we used ovariectomy (menopausal model) and type 2 diabetic (T2D) rats' models to evaluate the preclinical action of G-1 (GPR30 agonist) against cardiometabolic disorders. T2D was induced by a high-fat diet and a low dose of streptozotocin. G-1 was administrated for six weeks after the establishment of T2D.

RESULTS

We found that G-1 counteracts the effects of T2D and ovariectomy by increasing the body weight, reducing fasting blood sugar, heart weight, and heart weight to body weight ratio. Also, both ovariectomy and T2D led to decreases in the cardiac protein levels of hexokinase 2 (HK2) and GLUT4, while G-1-treated female rats reversed these changes and only increased HK2 protein level. In addition, T2D and ovariectomy increased glucose and glycogen content in the heart, but G-1 treatment significantly reduced them.

CONCLUSIONS

In conclusion, our work demonstrates that G-1 as a selective GPR30 agonist is a viable therapeutic approach against T2D and cardiometabolic diseases in multiple preclinical female models.

G Protein-Coupled Estrogen Receptor GPER: Molecular Pharmacology and Therapeutic Applications

The actions of estrogens and related estrogenic molecules are complex and multifaceted in both sexes. A wide array of natural, synthetic, and therapeutic molecules target pathways that produce and respond to estrogens. Multiple receptors promulgate these responses, including the classical estrogen receptors of the nuclear hormone receptor family (estrogen receptors α and β), which function largely as ligand-activated transcription factors, and the 7-transmembrane G protein-coupled estrogen receptor, GPER, which activates a diverse array of signaling pathways. The pharmacology and functional roles of GPER in physiology and disease reveal important roles in responses to both natural and synthetic estrogenic compounds in numerous physiological systems. These functions have implications in the treatment of myriad disease states, including cancer, cardiovascular diseases, and metabolic disorders. This review focuses on the complex pharmacology of GPER and summarizes major physiological functions of GPER and the therapeutic implications and ongoing applications of GPER-targeted compounds.

Protective effects of calorie restriction and 17-β estradiol on cardiac hypertrophy in ovariectomized obese rats

Obesity and menopause lead to cardiovascular diseases. Calorie restriction (CR) can modulate estrogen deficiency and obesity-related cardiovascular diseases. The protective effects of CR and estradiol on cardiac hypertrophy in ovariectomized obese rats were explored in this study. The adult female Wistar rats were divided into sham and ovariectomized (OVX) groups that received a high-fat diet (60% HFD) or standard diet (SD) or 30% CR for 16 weeks, and then, 1mg/kg E2 (17-β estradiol) was injected intraperitoneally every 4 days for four weeks in OVX-rats. Hemodynamic parameters were evaluated before and after each diet. Heart tissues were collected for biochemical, histological, and molecular analysis. HFD consumption led to weight gain in sham and OVX rats. In contrast, CR and E2 led to body weight loss in these animals. Also, heart weight (HW), heart weight/body weight (HW/BW) ratio, and left ventricular weight (LVW) were enhanced in OVX rats that received SD and HFD. E2 reduced these indexes in both diet conditions but reduction effects of CR were seen only in HFD groups. HFD and SD feeding increased hemodynamic parameters, ANP (atrial natriuretic peptide) mRNA expression, and TGF-β1(transforming growth factor-beta 1) protein level in the OVX animals, while CR and E2 reduced these factors. Cardiomyocyte diameter and hydroxyproline content were increased in the OVX-HFD groups. Nevertheless, CR and E2 decreased these indicators. The results showed that CR and E2 treatment reduced obesity-induced-cardiac hypertrophy in ovariectomized groups (20% and 24% respectively). CR appears to have almost as reducing effects as estrogen therapy on cardiac hypertrophy. The findings suggest that CR can be considered a therapeutic candidate for postmenopausal cardiovascular disease.

The G-Protein-Coupled Estrogen Receptor Agonist Prevents Cardiac Lipid Accumulation by Stimulating Cardiac Peroxisome Proliferator-Activated Receptor α: A Preclinical Study in Ovariectomized-Diabetic Rat Model

BACKGROUND

Type 2 diabetes mellitus (T2DM) is associated with cardiometabolic changes, and menopause exacerbates these conditions, leading to a greater risk of cardiovascular diseases (CVDs). The G protein-coupled estrogen receptor (GPER), which mediates the rapid effects of estrogen, has beneficial cardiac effects in both T2DM and menopause, but its mechanism of action is not well understood.

OBJECTIVES

This study aimed to determine whether G1 as a selective GPER-agonist has beneficial effects on cardiac lipid metabolism in ovariectomized rats with T2DM.

METHODS

Female Wistar rats were divided into 5 groups (n = 7 in each group): Sham-control (Sh-Ctl), T2DM, ovariectomized-T2DM (OVX-T2DM), OVX-T2DM-G1 (GPER-agonist), and OVX-T2DM-vehicle (OVX-T2DM-Veh). After stabilization of T2DM, G1 (200 μg/Kg) was administrated for 6 weeks. Then, the levels of free fatty acids (FFAs), CD36, peroxisome proliferator-activated receptor α (PPARα), and lipid accumulation in the cardiac tissue were determined.

RESULTS

Compared with the Sh-Ctl group, cardiac FFAs (P < 0.001), CD36 (P < 0.05), and lipid accumulation (P < 0.001) increased, and cardiac PPARα (P < 0.01) decreased in T2DM animals; ovariectomy intensified these changes. Also, cardiac FFAs, PPARα, and lipid accumulation (P < 0.05) significantly decreased in the OVX-T2DM-G1 group compared to the OVX-T2DM-Veh group. However, cardiac CD36 levels did not change.

CONCLUSIONS

G1 as a selective GPER-agonist affects lipid metabolism in T2DM animals. It also plays a vital role in improving cardiac metabolism during postmenopausal diabetic conditions.

Protective effects of combining SERMs with estrogen on metabolic parameters in postmenopausal diabetic cardiovascular dysfunction: The role of cytokines and angiotensin II

INTRODUCTION

The beneficial effects of the administration of selective estrogen receptor modulators (SERMs) and estrogen (E2), alone or in combination with each other, have been reported in postmenopausal diabetic cardiovascular dysfunction. In the present study, we determined the mechanism of action of SERMs and E2 on inflammatory balance, angiotensin II (Ang II) serum levels, and glycemic profile in a postmenopausal diabetic rat model.

METHODS

Ovariectomized rats with type 2 diabetes received daily SERMs (tamoxifen and raloxifene) and E2 for one month. After treatment, cardiovascular risk indices, glycemic profile, and serum Ang II, TNF-α and IL-10 levels were measured.

RESULTS

Type 2 diabetes caused an abnormal glycemic profile, which was exacerbated by ovariectomy. All treatments inhibited the effects of diabetes and ovariectomy on the glycemic profile, with combined treatments (SERMs + E2) showing stronger effects. Cardiovascular risk indices that became abnormal by diabetes and worsened by ovariectomy were improved in all treatment modalities. Also, combined treatment reduced serum Ang II, TNF-α, and the ratio of TNF-α to IL-10, indicating an improvement in inflammatory balance.

CONCLUSION

Our study showed the administration of SERMs and E2, alone or in combination, could be an effective alternative in the treatment of menopausal diabetes, and generally, the beneficial effects of combined treatments were more effective than the effects of E2 or SERMs alone. It appears that E2 or SERMs benefit the cardiovascular system by improving inflammatory balance and reducing Ang II levels.

DIFFERENTIAL CONTRIBUTION OF ESTROGEN RECEPTORS TO THE INTESTINAL THERAPEUTIC EFFECTS OF 17β-ESTRADIOL IN A MURINE MODEL OF PARKINSON'S DISEASE

Beneficial effects of estrogens have been reported in Parkinson's disease (PD) for many years. We previously reported their neuroprotective and anti-inflammatory potentials in the enteric nervous system of the intestine, a region possibly affected during the early stages of the disease according to Braak's hypothesis. Three different estrogen receptors have been characterized to date: the estrogen receptor alpha (ERα), the estrogen receptor beta (ERβ) and the G protein coupled estrogen receptor 1 (GPER1). The aim of the present study was to decipher the individual contribution of each estrogen receptor to the therapeutic properties of 17β-estradiol (E2) in the myenteric plexus of the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. Different agonists, 4,4',4''-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol (PPT; ERα), 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN; ERβ), G1 (GPER1), and antagonists, ICI 182,780 (ERα and ERβ), G15 (GPER1), were used to analyze the involvement of each receptor. We confirmed that G1 protects dopamine (DA) neurons to a similar extent as E2. An anti-inflammatory effect on proinflammatory macrophages and cultured human monocytes was also demonstrated with E2 and G1. The effects of PPT and DPN were less potent than G1 with only a partial neuroprotection of DA neurons by PPT and a partial reduction of interleukin (IL)-1β production in monocytes by PPT and DPN. Overall, the present results indicate that the positive outcomes of estrogens are mainly through activation of GPER1. Therefore, this suggests that targeting GPER1 could be a promising approach for future estrogen-based hormone therapies during early PD.

Comparative effects of estrogen and silibinin on cardiovascular risk biomarkers in ovariectomized rats

BACKGROUND

Silibinin is a polyphenolic compound that could modulate estrogen receptor activation. Vascular dysfunction is considered a key initiator in atherosclerosis and may occur in the postmenopausal period. This manuscript compares estrogen and silibinin's impacts on factors that change endothelial function in ovariectomized (OVX) rats.

METHODS

32 female Wistar rats were subdivided into control; OVX; OVX + estrogen (1 mg/kg/day); and OVX + silibinin (50 mg/kg/day) groups. After the experimental period, lipid profile, atherogenic indices, and histopathology of endothelium were monitored. The vascular oxidative stress, adhesion molecules, inflammatory cytokine levels, nitric oxide (NO), angiotensin-II (Ang-II), and endothelin-1 (ET-1) were also analyzed.

RESULTS

Silibinin treatment, similar to estrogen, significantly normalized the adverse changes of OVX on vascular function, including improved lipid profile and oxidative stress, increased endothelial nitric oxide synthase (eNOS) expression, diminished inflammatory status, and reduced adhesion molecule levels, ET-1 and Ang-II substances. Our findings also revealed that the administration with estrogen or silibinin resulted in a normal endothelium layer in the aorta tissues of OVX rats.

CONCLUSION

Estrogen and silibinin have similar effects in improving vascular function. These treatments' protective impacts on vasculature indicate their potential benefits on the cardiovascular system in the postmenopausal period.

Swimming training modulates lung injury induced by ovariectomy in diabetic rats: involvement of inflammatory and fibrotic biomarkers

CONTEXT

Previous studies have noted that the incidence of inflammatory and fibrotic diseases is higher in diabetic menopausal women.

OBJECTIVE

In the present study, we evaluated effects of swimming training on inflammatory and fibrotic biomarkers in the lung of ovariectomized diabetic rats.

MATERIALS AND METHODS

Forty female rats were assigned into four groups: sham; rats underwent surgery without ovariectomies, OVX: rats that underwent ovariectomies, OVX.Dia: ovariectomized rats with high-fat diet, OVX.Dia. Exe: ovariectomized diabetic rats with 8 weeks of swimming training. At the end of experiment, protein expressions were assessed with western blot. Lung sections were subjected to immunohistochemical and haematoxylin eosin staining.

RESULTS

There was a significant difference in the protein expressions between exercise and ovariectomized diabetic groups (p < .05).

CONCLUSION

The present study showed strong potential of swimming training on oestrogen deficient diabetic lung. These data encourage further investigation into the inclusive effects of exercise in menopausal diabetic women.

The different role of G-protein-coupled receptor 30 (GPR30) in the interaction effects of marijuana and estradiol on spatial learning and memory at different ages

Some studies suggest that the effect of cannabis on behavior performance depends on the presence of ovarian hormones and the age of use initiation. Estradiol is the main ovarian hormone that can interact with cannabinoids. It has been suggested that cannabinoids exert some of their effects directly through estrogen receptors (ERs). A novel G-protein-coupled receptor (GPR30) was described as mediating estrogen signaling in various cell lines. Since there are few studies on the interaction of cannabis and ovarian hormones on cognitive behaviors, so, this study evaluated the role of GPR30 in the effects of marijuana (M) and estrogen, alone and in combination, on spatial learning and memory of young (non-ovarian(OVX)) and old female rats. Young (5-7 months) and old (22-24 months) female rats received an intraperitoneal injection (i.p) of 17β-estradiol (E2), G1 (GPR30 agonist), and G15 (GPR30 antagonist) every four days, and M (every day), either alone or in combination, for 28 days. One hour after the last injection, the Morris water maze (MWM) test was conducted to evaluate of spatial learning and memory. Moreover, hippocampal BDNF level was assessed by the ELISA method. The results showed a positive effect of M on spatial learning in both young and old rats, however, E2 showed beneficial effects on the memory of young, but not old rats. Our results showed that GPR30 does not have any role in the interaction effects of M and E2 in young rats. Although both E2 and M alone showed positive effects on spatial learning and memory in old rats, however, our results showed a negative interaction between marijuana and E2 combined effects on spatial learning and memory in old female rats which is mediated by GPR30. Our results showed that the effects of GPR30 on spatial learning and memory is age dependent. Furthermore, this study showed that hippocampal BDNF does not have any role in the interaction effects of M and E2 on spatial learning and memory in young and old rats.

FTZ Ameliorates Diabetic Cardiomyopathy by Inhibiting Inflammation and Cardiac Fibrosis in the Streptozotocin-Induced Model

Background

The pathogenesis and clinical features of diabetic cardiomyopathy (DCM) have been well studied in the past decade; however, effective approaches to prevent and treat this disease are limited. Fufang Zhenzhu Tiaozhi (FTZ) formula, a traditional Chinese prescription, is habitually used to treat dyslipidemia and diabetes. Recently, several studies have reported the therapeutic effects of FTZ on cardiovascular diseases. However, the effects of FTZ on DCM have not yet been fully elucidated. This study investigated the effects of FTZ on DCM and determined the mechanisms underlying its efficacy.

Methods

Diabetes was induced in mice by intraperitoneal injection of streptozotocin; the mice were randomly divided into a control group (Con), diabetes group (DCM), and diabetes-treated with FTZ (DCM + FTZ). Myocardial structural alterations, fibrosis biomarkers, and inflammation were observed. Besides, the potential targets and their related signaling pathways were analyzed using network pharmacology and further verified by Western blot.

Results

Diabetic mice showed significant body weight loss, hyperglycemia, and excessive collagen content in the cardiac tissue, while serum and myocardial inflammatory factors significantly increased. Nerveless, treatment with FTZ for 1 month significantly improved body weight, attenuated hyperglycemia, and alleviated diabetes-associated myocardial structure and function abnormalities. Furthermore, the serum levels of interleukin 12 (IL-12) and chemokine (C–C motif) ligand 2 (CCL2) as well as the mRNA levels of cardiac IL-12, IL-6, and C–C motif chemokine receptor 2 (Ccr2) reduced after FTZ treatment. Additionally, a total of 67 active compounds and 76 potential targets related to DCM were analyzed. Pathway and functional enrichment analyses showed that FTZ mainly regulates inflammation-related pathways, including MAPK and PI3K-AKT signaling pathways. Further investigation revealed that the activities of STAT3, AKT, and ERK were augmented in diabetic hearts but decreased in FTZ-treated cardiac tissues.

Conclusion

Our results suggest that FTZ exhibits therapeutic properties against DCM by ameliorating hyperglycemia-induced inflammation and fibrosis via at least partial inhibition of AKT, ERK, and STAT3 signaling pathways.

Progesterone eliminates 17β-estradiol-Mediated cardioprotection against diabetic cardiovascular dysfunction in ovariectomized rats

Background

Type2 Diabetes (T2D) remains one of the most important causes of cardiovascular diseases (CVD). Menopause leads to an increase in CVD and metabolic syndrome, which indicates the role of sex steroids as a protective factor. In the present study, we surveyed the effects of 17β-estradiol (E2) alone and in combination with progesterone (P4) on cardiovascular dysfunction in T2D.

Methods

Female ovariectomized (OVX) diabetic rats were divided into eight groups: Sham-Control, Diabetes (Dia), OVX + Dia, OVX + Dia + Vehicle, OVX + Dia + E2, OVX + Dia + P4, OVX + Dia + E2+P4, and OVX + Dia + E2+Vehicle. T2D was induced by a high-fat diet and streptozotocin. E2 and P4 were administrated every four days for four weeks. The heart cytokines and angiotensin II, lipid profile, insulin, water, and food intake and cardiovascular indices were measured.

Results

Results showed that single treatment with E2 decreased fasting blood glucose, water, and food intake, atherogenic and cardiac risk indices, and blood pressure. Also, P4 led to a decrease in atherogenic and cardiac risk indices. TNFα and IL-6 levels were increased and IL-10 was decreased in the Dia group, while E2 alone was able to inhibit these changes. The combined use of E2 and P4 eliminated the beneficial effects of E2 on these indices. Although diabetes results in an increment of cholesterol, LDL and triglyceride, hormone therapy with E2 was associated with improved dyslipidemia.

Conclusion

The use of E2 alone, and not the individual use of P4, and its combination with E2 improved cardiovascular function in OVX diabetic animals, possibly by reducing the amount of inflammatory cytokines and improving metabolic parameters.

G protein-coupled estrogen receptor 1: a novel target to treat cardiovascular disease in a sex-specific manner?

As an agonist of the classical nuclear receptors, estrogen receptor-α and -β (NR3A1/2), estrogen has been assumed to inhibit the development of cardiovascular disease in premenopausal women. Indeed, reduced levels of estrogen after menopause are believed to contribute to accelerated morbidity and mortality rates in women. However, estrogen replacement therapy has variable effects on cardiovascular risk in postmenopausal women, including increased serious adverse events. Interestingly, preclinical studies have shown that selective activation of the novel membrane-associated G protein-coupled estrogen receptor, GPER, can promote cardiovascular protection. These benefits are more evident in ovariectomised than intact females or in males. It is therefore possible that selective targeting of the GPER in postmenopausal women could provide cardiovascular protection with fewer adverse effects that are caused by conventional 'receptor non-specific' estrogen replacement therapy. This review describes new data regarding the merits of targeting GPER to treat cardiovascular disease with a focus on sex differences.

17β-Estradiol alleviates cardiac aging induced by d-galactose by downregulating the methylation of autophagy-related genes

Intrinsic cardiac aging increases cardiovascular mortality and morbidity in the elderly. Estrogen helps reduce the risk of cardiovascular disease in women, with 17β-estradiol (17β-E₂) activating the autophagy pathway and inhibiting vascular aging, mainly through estrogen receptor alpha (ER α) to prevent atherosclerosis. Abnormal methylation of autophagy-related genes can impact autophagic regulation. We hypothesized that 17β-E₂, specifically 17β-E₂ α, downregulates the methylation of autophagy factors and delays cardiac aging. Here, we used d-galactose, 17β-E₂, and ER α receptor antagonist methyl-piperidino-pyrazole (MPP) to establish different aging models in mice divided into four groups, namely negative control, D.gal, D.gal + 17β-E₂, and D.gal + 17β-E₂ + MPP groups. Echocardiography showed that compared with the D.gal group group, the D.gal + 17β-E₂ showed substantially increased cardiac function. The level of cardiac aging markers in mice in the D.gal + 17β-E₂ group was lower than that in mice in the D.gal group. Beclin1, LC3, and Atg5 mRNA and protein expression levels in mice in the D.gal + 17β-E₂ group were significantly increased compared with those in the D.gal group. Additionally, Beclin1, LC3, and Atg5 methylation levels were significantly decreased in the D.gal + 17β-E₂ group. All the above values of the D.gal + 17β-E₂ + MPP group were between those of the D.gal and D.gal + 17β-E₂ groups. The expression of Dnmt1, Dnmt2, and Dnmt3A genes was the highest in the D.gal group. In summary, our results suggest that 17β-E₂, specifically 17β-E₂ α, promotes autophagy by downregulating the methylation of autophagy factors, thereby inhibiting galactose-induced cardiac aging in mice. 17β-E₂ may be a potential therapeutic target to mitigate the effects of cardiac aging.

Activation of GPR30 with G1 inhibits oscillatory shear stress-induced adhesion of THP-1 monocytes to HAECs by increasing KLF2

Atherosclerosis is a chronic inflammatory disease known to be mediated by numerous factors, among which endothelial dysfunction plays a critical role. Oscillatory shear stress induces endothelial cells to lose their anti-atherosclerotic properties and downregulates the expression of the innate protective transcription factor, Krüppel-like factor 2 (KLF2), which is typically upregulated in vascular endothelial cells in response to harmful stimuli. Oxidative stress and inflammation impair endothelial function and damage their survival. Oscillatory shear stress also promotes generation of reactive oxygen species and production of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), thereby further promoting endothelial dysfunction and formation of atherosclerotic plaque. A major event in the development of atherosclerotic plaque is rolling and adhesion of monocytes to endothelial cells, which is mediated by adhesion molecules including vascular cellular adhesion molecule 1 and endothelial-selectin. Expression of these molecules is also upregulated by oscillatory shear stress. Estrogen has long been recognized as a protective agent against atherosclerosis, but the mechanisms through which estrogen receptors prevent atherogenesis remain unclear. In the present study, we investigated the role of the G-coupled protein estrogen receptor (GPR30) in oscillatory shear stress- induced endothelial dysfunction. We show that agonism of GPR30 by its specific agonist G1 prevented oscillatory shear stress -induced oxidative stress markers and production of inflammatory cytokines and adhesion molecules. As a result, GPR30 activation suppresses monocytes adhesion to endothelial cells. Furthermore, we demonstrate that GPR30 prevents oscillatory shear stress- induced downregulation of KLF2 via ERK5 pathway. These findings suggest that endothelial GPR30 is potential target to suppress oscillatory shear stress mediated atherogenesis.

Polyherbal mixture ameliorates hyperglycemia, hyperlipidemia and histopathological changes of pancreas, kidney and liver in a rat model of type 1 diabetes

ETHNOPHARMACOLOGICAL RELEVANCE

One of the commonly prescribed 'anti-diabetic' polyherbal mixtures by European herbalists is made of Rubus fruticosus and Vaccinium myrtillus leaves, Potentilla erecta roots, Geum urbanum aerial parts and Phaseolus vulgaris pods.

AIM OF THE STUDY

This study aimed to evaluate the phytochemical composition, antioxidant capacity, potential toxicity, hypoglycemic, hypolipidemic, nephroprotective and hepatoprotective activities of this polyherbal mixture decoction.

MATERIALS AND METHODS

The phytochemical composition was evaluated using HPLC-UV. The antioxidant activity was assessed using the DPPH test. Potential toxicity was evaluated using the acute and sub-chronic oral toxicity method. Diabetes was induced in Wistar female rats with a single intraperitoneal injection of alloxan monohydrate (150 mg/kg). The animals whose blood glucose was >20 mmol/L for 14 consecutive days were considered diabetic. For the next 14 days, D-10 and D-20 groups were treated with the polyherbal mixture (10 and 20 g of dry plant material/kg, respectively). I and M were control groups treated with insulin glargine (13 IU/kg) and metformin (150 mg/kg), respectively. Healthy control (HC) and diabetic control (DC) groups were treated with water. The blood glucose level was measured on days 14, 21 and 28. Lipid profile analysis was done on day 28. Pancreas, kidney and liver histopathology was evaluated using the H&E and Masson's trichrome staining. The liver tissue was additionally tested for PAS-positive cells.

RESULTS

The HPLC-UV analysis revealed the presence of quinic, gallic and caftaric acid, arbutin, rutin, trifolin, astragalin, hyperoside, isoquercetin and quercitrin. The antioxidant activity of the extract was higher than the reference's one (p < 0.01). Treatment with the polyherbal mixture (10 and 20 g/kg) has shown no toxic effects. No major decline in blood sugar was recorded in I and M groups compared to the DC one (22.86 ± 2.58, 28.5 ± 0.42 and 27.82 ± 0.9 mmol/L, respectively). The polyherbal mixture lowered the blood glucose level to the normal value (8.64 ± 4.09, 5.26 ± 1.3 and 6.76 ± 1.54 mmol/L in D-10, D-20 and HC groups, respectively). Furthermore, it decreased the levels of total cholesterol, triglycerides, VLDL, LDL, atherogenic and cardiovascular risk indices (p < 0.001) compared to the DC group. In addition, the extract restored histopathological changes of the pancreas, kidneys and liver to the healthy animal level.

CONCLUSION

Treatment with the polyherbal mixture extract was more effective than the standard drugs (insulin and metformin) in the amelioration of hyperglycemia, hyperlipidemia, and histopathological changes of the pancreas, kidney and liver tissue.

Estrogen receptors in human bladder cells regulate innate cytokine responses to differentially modulate uropathogenic E. coli colonization

The bladder epithelial cells elicit robust innate immune responses against urinary tract infections (UTIs) for preventing the bacterial colonization. Physiological fluctuations in circulating estrogen levels in women increase the susceptibility to UTI pathogenesis, often resulting in adverse health outcomes. Dr adhesin bearing Escherichia coli (Dr E. coli) cause recurrent UTIs in menopausal women and acute pyelonephritis in pregnant women. Dr E. coli bind to epithelial cells via host innate immune receptor CD55, under hormonal influence. The role of estrogens or estrogen receptors (ERs) in regulating the innate immune responses in the bladder are poorly understood. In the current study, we investigated the role of ERα, ERβ and GPR30 in modulating the innate immune responses against Dr E. coli induced UTI using human bladder epithelial carcinoma 5637 cells (HBEC). Both ERα and ERβ agonist treatment in bladder cells induced a protection against Dr E. coli invasion via upregulation of TNFα and downregulation of CD55 and IL10, and these effects were reversed by action of ERα and ERβ antagoinsts. In contrast, the agonist-mediated activation of GPR30 led to an increased bacterial colonization due to suppression of innate immune factors in the bladder cells, and these effects were reversed by the antagonist-mediated suppression of GPR30. Further, siRNA-mediated ERα knockdown in the bladder cells reversed the protection against bacterial invasion observed in the ERα positive bladder cells, by modulating the gene expression of TNFα, CD55 and IL10, thus confirming the protective role of ERα. We demonstrate for the first time a protective role of nuclear ERs, ERα and ERβ but not of membrane ER, GPR30 against Dr E. coli invasion in HBEC 5637 cells. These findings have many clinical implications and suggest that ERs may serve as potential drug targets towards developing novel therapeutics for regulating local innate immunity and treating UTIs.

MiR-155-Mediated Deregulation of GPER1 Plays an Important Role in the Gender Differences Related to Inflammatory Bowel Disease

Aim

The incidence and clinical manifestations of inflammatory bowel disease (IBD) are thought to have gender differences, which suggests that the estrogen signaling pathway and intestinal flora may play key roles in the pathogenesis of IBD. In IBD, microRNA-155 (miR-155) is upregulated and regulates G protein coupled estrogen receptor (GPER1), which affects the intestinal flora. The objective of this study was to investigate the role of the estrogen receptors and miR-155 in the pathogenesis of IBD.

Methods

From July 2018 to July 2019, in the Department of Gastroenterology at Daping Hospital, Army Military Medical University, a total of 50 patients with IBD were included in this study, and 24 healthy examinees were randomly selected as the control group. Colonoscopies were performed, and clinical characteristics and blood samples were collected from all of the subjects. The serum cytokine levels in the patients with IBD and the health donors were detected by ELISA, and the estrogen receptor level measurements for all of the participants were assessed by immunohistochemistry (IHC) and quantitative real-time PCR (qPCR). The miR-155 levels were detected by qPCR in all of the participants, and miR-155^−/− mice were used to investigate the mechanism of miR-155 in the pathogenesis of IBD.

Results

The clinical characteristics and medications were different for the IBD patients when gender was considered. The male patients produced more proinflammatory cytokines, and while GPER1 expression was downregulated, miR-155 was upregulated in the patients with IBD. MiR-155 showed proinflammatory activity, while GPER1 showed an anti-inflammatory response during the pathogenesis of IBD. The miR-155^−/− mice showed improvements in weight loss, survival, rectal bleeding, colon length, and histopathological changes compared with the wild-type mice. Furthermore, the male miR-155^−/− mice showed increased inflammation compared to the female miR-155^−/− mice in the above aspects.

Conclusion

This study presents evidence indicating that miR-155 plays a key role in the pathogenesis of IBD for the different genders. MiR-155 was upregulated and showed proinflammatory activity, whereas GPER1 showed an anti-inflammatory response during the pathogenesis of IBD. The results demonstrated that more proinflammatory cytokines and reduced GPER1 levels were observed in the male IBD patients. Thus, miR-155 was involved in the regulation of GPER1 and induced gender differences in IBD patients. MiR-155 may be a potential marker for IBD-targeted therapy.

Evolution of TLR4 role in mediating the hepatoprotective effects of estradiol after traumatic brain injury in male rats

Several studies have shown that 17β-estradiol (E2) exerted beneficial effects on liver disease, and it has a protective impact on brain damage after traumatic brain injury (TBI). TBI-induced liver injury is associated with the activation of TLR4. However, it remains unknown whether E2 can modulate TBI-induced liver injury through TLR4. The objective of this study was to determine the role of TLR4 in hepatoprotective mechanisms of E2 after TBI. Diffuse TBI induced by the Marmarou model in male rats. TAK-242 as a selective antagonist of TLR4 (3 mg/kg) and E2 (33.3 μg/kg) were injected (i.p) respectively 30 min before and 30 min after TBI. The results showed that E2 and TAK-242 markedly inhibited TBI-induced liver injury, which was characterized by decreased aminotransferase activities, inhibition of the oxidative stress, and reduced levels of pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and IL-17 in the liver. We also found that TBI induced significant upregulation of TLR4 in the liver, with peak expression occurring 24 h after TBI, and that treatment with E2 significantly inhibited the upregulation of TLR4. Also, both classic [Estrogen receptors alpha (ERα) and beta (ERβ)] and non-classic (G protein-coupled estrogen receptor GPER) E2 receptors are involved in modulating the expression of TLR4. These results suggested that the hepatoprotective effects of estradiol after TBI may be mediated via the downregulation expression of TLR4.

17β-Estradiol improves insulin signalling and insulin resistance in the aged female hearts: Role of inflammatory and anti-inflammatory cytokines

Aging effects in energy balance in all tissues and organs, including the cardiovascular. The risk of cardiovascular disease is drastically higher in postmenopausal women than in premenopausal women. Estrogen plays an important role in the cardiac function and body's metabolism. The aim of this study was to determine whether 17β-estradiol (E2) has beneficial effects on insulin resistance and some key stages of the insulin signalling pathway in the aged hearts. Young and aged female Wistar rats were ovariectomized and were randomly divided into three groups: young (YS) and aged (AS) sham, young (YV) and aged (AV) vehicle, and young (YE2) and aged (AE2) E2 treatment groups. E2 (1 mg/kg) was administrated every four days for four weeks. Results showed that ovariectomy increased fasting blood glucose, insulin, and HOMAIR in young, while none of these parameters was affected in aged animals. On the other hand, aging itself increased these variables. Furthermore, E2 therapy alleviated these changes in both young and aged animals. Moreover, aging also decreased the p-IRS1, p-Akt level, and translocation of GLUT4 to the plasma membrane. E2 reduced the negative impact of menopause and aging on insulin sensitivity by favoring increase in the level of IL-10 and decrease in the levels of TNF-α and IL-1β. Our results indicated that the heart response to E2 depended on age, and E2 increased insulin sensitivity in the heart of both young and aged animals by altering inflammatory conditions. Determining the exact mechanism of this action is suggested in future studies.

Aging is associated with loss of beneficial effects of estrogen on leptin responsiveness in mice fed high fat diet: Role of estrogen receptor α and cytokines

Aging causes changes in body composition and energy balance. Estrogen plays an important role in body's metabolism. The aim of this study was to determine whether estrogen has beneficial effects on leptin responsiveness in aged mice. Young 4 months and aged 19-21 female mice fed High Fat Diet (HFD) or Standard Diet (SD) for 12 weeks and following received estrogen for 4 weeks. Responsiveness to leptin was compared by measuring energy balance parameters. Results showed that HFD caused weight gain compared to SD in young, but had no effect on aged animals. Estrogen reduced body weight, energy intake and visceral fat in young, while none of these parameters was affected in aged animals. Although there was leptin sensitivity in aged compared to ovariectomized animals, estrogen only improved the sensitivity of young to leptin. Estrogen prevented increase in TNF-α and a decrease in IL-10 in HFD young and aged animals. Response to estrogen depended on age, and estrogen increased leptin sensitivity only in young animals. Determining the exact mechanism of this action is suggested in future studies.

Antidiabetic and hypolipidemic efficacy of skin and seed extracts of Momordica cymbalaria on alloxan induced diabetic model in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Momordica cymbalaria, a wild vegetable belongs to the Cucurbitaceae family, has long been used as a food and a remedy for diabetes mellitus in the Asian native medicinal system.

AIM OF THE STUDY

This study aims to evaluate the efficacy of ethanolic extract of skin (EESK) and methanolic extract of seed (MESE) of M. cymbalaria (MC), for their hypoglycemic and hypolipidemic effects in alloxan induced diabetic rats.

MATERIALS AND METHODS

The diabetes induced rats were given skin and seed extracts at doses 250 and 500 mg/kg b.w. p.o. for 28 days. Alloxan monohydrate (120 mg/kg) was used to induce diabetes mellitus. Daily food and water intake were assessed. Blood glucose levels and body weights were measured every 7 days throughout the experiment. Antioxidant assays, different biochemical and glycemic parameters were evaluated. Histopathological studies on pancreas, liver and kidney were also studied.

RESULTS

Treatment of EESK and MESE showed dose significant decrease in fasting blood glucose level (FBG) in experimental diabetic animals with significant reduction in food and water intake and increase in body weight. Findings confirmed the hypoglycemic and hypolipidemic effects of EESK and MESE in the experimental groups. The impaired glucose tolerance and altered activities of the hepatic enzymes such as AST, ALT and ALP levels of diabetic rats were significantly improved by the administration of EESK and MESE. Oral treatment with MC extract for 28 days demonstrated significant protective effects on the lipid profile, biochemical parameters and antioxidant levels. Besides, biochemical findings were supported by histopathological investigations.

CONCLUSION

These results suggest that the treatment with EESK and MESE of MC at a dose of 500 mg/kg b.w. have better protective effects against hyperglycemia, hyperlipidemia and oxidative stress generated during diabetes justifying the use of the plant in traditional systems of medicine.

Female Heart Health: Is GPER the Missing Link?

The G Protein-Coupled Estrogen Receptor (GPER) is a novel membrane-bound receptor that mediates non-genomic actions of the primary female sex hormone 17β-estradiol. Studies over the past two decades have elucidated the beneficial actions of this receptor in a number of cardiometabolic diseases. This review will focus specifically on the cardiac actions of GPER, since this receptor is expressed in cardiomyocytes as well as other cells within the heart and most likely contributes to estrogen-induced cardioprotection. Studies outlining the impact of GPER on diastolic function, mitochondrial function, left ventricular stiffness, calcium dynamics, cardiac inflammation, and aortic distensibility are discussed. In addition, recent data using genetic mouse models with global or cardiomyocyte-specific GPER gene deletion are highlighted. Since estrogen loss due to menopause in combination with chronological aging contributes to unique aspects of cardiac dysfunction in women, this receptor may provide novel therapeutic effects. While clinical studies are still required to fully understand the potential for pharmacological targeting of this receptor in postmenopausal women, this review will summarize the evidence gathered thus far on its likely beneficial effects.