Clinical issues regarding cardiovascular disease and selective estrogen receptor modulators in postmenopausal women

New potential selective estrogen receptor modulators in traditional Chinese medicine for treating menopausal syndrome

Women go through several predictable conditions and symptoms during menopause that are caused by age, changes in sex hormone levels, and other factors. Conventional menopause hormone therapy has raised serious concerns about the increased risks of cancers, blood clots, depression, etc. Selective estrogen receptor modulators (SERMs) that can be both agonists and antagonists of estrogen receptors in a tissue-specific manner are being developed to reduce the health concerns associated with menopause hormone therapy. Here, we have searched the Chinese national traditional Chinese medicine (TCM) patent database to identify potential SERM-like compounds with reduced health risks. TCM has been widely used for treating complex symptoms associated with menopause syndrome and thus can be a particularly rich source for pharmaceutical alternatives with SERM properties. After extensive literature review and molecular simulation, we conclude that protopanaxatriol, paeoniflorin, astragalin, catalpol, and hyperoside among others may be particularly promising as SERM-like compounds in treating the menopausal syndrome. Compounds in TCM hold promise in yielding comparable outcomes to hormone therapy but with reduced associated risks, thus presenting promising avenues for their clinical applications.

Cell membrane coated nanoparticles: cutting-edge drug delivery systems for osteoporosis therapy

Osteoporosis, characterized by a reduction in bone mineral density, represents a prevalent skeletal disorder with substantial global health implications. Conventional therapeutic strategies, exemplified by bisphosphonates and hormone replacement regimens, though effective, encounter inherent limitations and challenges. Recent years have witnessed the surge of cell-membrane-coated nanoparticles (CMNPs) as a promising intervention for osteoporosis, leveraging their distinct attributes including refined biocompatibility, heightened pharmaceutical payload capacity, as well as targeted drug release kinetics. However, a comprehensive review consolidating the application of CMNPs-based therapy for osteoporosis remains absent within the existing literature. In this review, we provide a concise overview of the distinctive pathogenesis associated with osteoporosis, alongside an in-depth exploration of the physicochemical attributes intrinsic to CMNPs derived from varied cellular sources. Subsequently, we explore the potential utility of CMNPs, elucidating emerging trends in their deployment for osteoporosis treatment through multifaceted therapeutic approaches. By linking the notable attributes of CMNPs with their roles in mitigating osteoporosis, this review serves as a catalyst for further advances in the design of advanced CMNPs tailored for osteoporosis management. Ultimately, such progress is promising for enhancing outcomes in anti-bone loss interventions, paving the way for clinical translation in the near future.

Ospemifene for the treatment of menopausal vaginal dryness, a symptom of the genitourinary syndrome of menopause

Introduction: Vulvovaginal atrophy (VVA), a component of the genitourinary syndrome of menopause, is a progressive condition due to decline in estrogen leading to vaginal and vulvar epithelial changes. Accompanying symptoms of dryness, irritation, burning, dysuria, and/or dyspareunia have a negative impact on quality of life. Ospemifene is a selective estrogen receptor modulator (SERM) approved by the FDA for moderate to severe dyspareunia and vaginal dryness due to postmenopausal VVA. Areas covered: PubMed was searched from inception to March 2019 with keywords ospemifene and vulvar vaginal atrophy to review preclinical and clinical data describing the safety and efficacy of ospemifene for vaginal dryness and dyspareunia due to VVA. Covered topics include efficacy of ospemifene on vaginal cell populations, vaginal pH, and most bothersome VVA symptoms; imaging studies of vulvar and vaginal tissues; effects on sexual function; and safety of ospemifene on endometrium, cardiovascular system, and breast. Expert opinion: Ospemifene is significantly more effective than placebo in all efficacy analyses studied, working through estrogen receptors and possibly androgen receptors. Safety as assessed by adverse events was generally comparable to that with placebo and to other SERMs, and/or adverse events were not clinically meaningful. No cases of endometrial or breast cancer were reported.

Can osteoporosis increase the incidence of heart failure in adults?

BACKGROUND

Recent studies have suggested shared comorbidities between heart failure and osteoporosis. In addition, patients with osteoporosis are associated with increased risks of developing cardiovascular disease.

METHODS

A retrospective cohort analysis was conducted to determine the association between osteoporosis and heart failure. Data was from the Longitudinal Health Insurance Database 2000 (LHID 2000), Taiwan. Patients with newly diagnosed osteoporosis were identified, and osteoporosis-free controls were randomly selected from the general population and frequency matched according to age, sex, and index year using the LHID 2000. We analyzed the risks of heart failure using Cox proportional-hazards regression models.

RESULTS

During the mean follow-up of 7.1 ± 3.5 years, the cumulative incidence of heart failure was 2.24% higher in the osteoporosis cohort than in the comparison cohort (p < .001). The overall incidence of heart failure was 10.3 versus 7.62 per 1000 person-years in osteoporosis patients and controls, respectively, with an adjusted HR of 1.13 (95% CI = 1.06-1.21).

CONCLUSION

We observed a higher incidence of developing heart failure in Taiwanese adults with osteoporosis, especially in those with chronic comorbidities. There might be linking pathophysiology and mechanisms from osteoporosis to heart failure.

The Tissue-Selective Estrogen Complex: A Review of Current Evidence

The tissue-selective estrogen complex (TSEC) has recently entered the market for the treatment of postmenopausal osteoporosis, and is particularly targeted to women with significant vasomotor symptoms. This review appraises the evidence behind the only approved TSEC to-date, a combination of bazedoxifene and conjugated estrogens, with regards to its efficacy and relevant safety concerns. The majority of evidence that has led to its approval is derived from the SMART study. This large phase III trial with several substudies was aimed at discerning the effects of the TSEC on various estrogen-responsive tissues in comparison to raloxifene and placebo. Overall, the evidence thus far suggests a superior improvement in lumbar bone mineral density of 1.01% ± 0.28% as well as decrease in the frequency of hot flushes. Regarding safety concerns, endometrial thickness did not change over the treatment course, and investigators also identified a modest reduction in breast density. While there was no difference in rates of venous thromboembolism between treatment and placebo groups in a 2-year follow-up period, the effects of the drug on coagulation profiles are similar to those seen with hormone replacement therapy. Thus, the drug's effects on venous thromboembolism risk over a longer treatment course remain unclear. In conclusion, the actual efficacy of the TSEC for postmenopausal osteoporosis remains as yet undefined, given the lack of fracture prevention data. The evidence thus far does seem to suggest a beneficial effect on vasomotor symptoms and a generally favorable side effect profile. However, it should be noted that only one study has addressed this question thus far, and so the repeatability of the findings is still in question.

Use of SERMs for treatment in postmenopausal women

Selective estrogen receptor modulators (SERMs) are synthetic non-steroidal agents which have varying estrogen agonist and antagonist activities in different tissues, most likely due to the receptor conformation changes associated with that SERM's binding and the subsequent effect on transcription. Clinical trials aim to differentiate amongst SERMs on selected target tissues for use in postmenopausal women including effects on breast, bone, cardiovascular venous thrombosis risk, endometrium, vagina, vasomotor symptoms, and brain. This paper describes differences in clinical effects on selected target tissues of SERMs that are approved, discontinued or in development. FDA approved SERMs include tamoxifen and toremifene used for prevention and treatment of breast cancer, raloxifene approved for prevention and treatment of osteoporosis and prevention of invasive breast cancer, and ospemifene approved for treatment of dyspareunia from menopausal vaginal atrophy. The FDA approved first tissue selective estrogen complex (TSEC) a pairing of conjugated equine estrogens with the SERM, bazedoxifene. This pairing reduces the risk of endometrial hyperplasia that can occur with the estrogenic component of the TSEC without the need for a progestogen in women with a uterus. It also allows for the estrogenic benefits on relief of hot flashes and prevention of bone loss without stimulating the breast or the endometrium. In clinical practice, the tissue-selective actions of SERMs, alone or paired with estrogens, allow for individualization in meeting the treatment needs of postmenopausal women by providing targeted tissue effects. This article is part of a Special Issue entitled 'Menopause'.

Vascular effects of estrogenic menopausal hormone therapy

Cardiovascular disease (CVD) is more common in men and postmenopausal women (Post-MW) than premenopausal women (Pre-MW). Despite recent advances in preventive measures, the incidence of CVD in women has shown a rise that matched the increase in the Post-MW population. The increased incidence of CVD in Post-MW has been related to the decline in estrogen levels, and hence suggested vascular benefits of endogenous estrogen. Experimental studies have identified estrogen receptor ERα, ERβ and a novel estrogen binding membrane protein GPR30 (GPER) in blood vessels of humans and experimental animals. The interaction of estrogen with vascular ERs mediates both genomic and non-genomic effects. Estrogen promotes endothelium-dependent relaxation by increasing nitric oxide, prostacyclin, and hyperpolarizing factor. Estrogen also inhibits the mechanisms of vascular smooth muscle (VSM) contraction including [Ca2+]i, protein kinase C and Rho-kinase. Additional effects of estrogen on the vascular cytoskeleton, extracellular matrix, lipid profile and the vascular inflammatory response have been reported. In addition to the experimental evidence in animal models and vascular cells, initial observational studies in women using menopausal hormonal therapy (MHT) have suggested that estrogen may protect against CVD. However, randomized clinical trials (RCTs) such as the Heart and Estrogen/ progestin Replacement Study (HERS) and the Women's Health Initiative (WHI), which examined the effects of conjugated equine estrogens (CEE) in older women with established CVD (HERS) or without overt CVD (WHI), failed to demonstrate protective vascular effects of estrogen treatment. Despite the initial set-back from the results of MHT RCTs, growing evidence now supports the 'timing hypothesis', which suggests that MHT could increase the risk of CVD if started late after menopause, but may produce beneficial cardiovascular effects in younger women during the perimenopausal period. The choice of an appropriate MHT dose, route of administration, and estrogen/progestin combination could maximize the vascular benefits of MHT and minimize other adverse effects, especially if given within a reasonably short time after menopause to women that seek MHT for the relief of menopausal symptoms.

Antibody-mediated "universal" osteoclast targeting platform using calcitonin as a model drug

Purpose

To generate and characterize a specific monoclonal antibody (mAb) against recombinant human RANK receptor and to develop an antiresorptive strategy using this mAb as an osteoclast-targeting platform that selectively targets osteoclast cells whilst delivering an attached (i.e. chemically conjugated) active drug cargo.

Methods

Using hybridoma technology, we generated a specific monoclonal antibody (mAb) against recombinant human RANK receptor and characterized by SDS PAGE, ELISA, Western Blot and immunocytochemistry, then synthesized osteoclast-targeting bioconjugates of salmon calcitonin (sCT) using this antibody by generating thiol groups on mAb using 2-Iminothiolane and subsequently reacting them with sCT-PEG-MAL synthesised from sCT and NHS-PEG-MAL. To test the efficacy of the conjugate in vitro, osteoclasts were generated from precursor RAW 264.7 cells by dosing with the cytokines macrophage-colony-stimulating factor (M-CSF), and RANK Ligand (RANKL) and TRAP activity assay, Resorption Pit Assay, TRAP staining were performed. Cytotoxicity of the mAb-sCT conjugate was also evaluated in RAW 264.7 cells; sCT bioactivity and CTR binding potential were evaluated by in vitro intracellular cAMP stimulation assay in human T47D breast cancer cells.

Results

Generation of antibody against human RANK receptor was confirmed by SDS PAGE, ELISA and Western Blot. Immunocytochemistry confirmed the osteoclast targeting potential of the antibody. Successful conjugation of the antibody with sCT was confirmed by SDS PAGE and ELISA.Multinucleated osteoclast formation was confirmed by staining for tartrate-resistant acid phosphatase (TRAP). Conjugate functionality was confirmed by TRAP activity and Resorption Pit assay, showing the inhibitory effect on osteoclast differentiation. cAMP assay confirmed the retention of calcitonin bioactivity after conjugation.

Conclusions

Our strategy offers the potential for a “universal” osteoclast-targeting platform—one that targets the RANK receptor on osteoclast cells by simply altering the conjugated cargo in order to affect the specific regulation of osteoclast cells.

New selective estrogen receptor modulators (SERMs) in development

Selective estrogen receptor modulators (SERMs) or estrogen agonists/antagonists have shown promise in osteoporosis in that they have the potential to reduce the risk of fracture, and also reduce the risk of breast cancer. SERMs maybe classified according to their core structure, which is typically a variation of the 17 beta-estradiol template and subclassified according to the side chain at the helix 12 affector region. The best known are the triphenylethylenes such as tamoxifen, used in the management of breast cancer. However, the clinical application of this class of SERMs has been limited due to endometrial stimulation. A second class is the benzothiophenes such as raloxifene and arzoxifene, which have skeletal benefit with little, if any, uterine stimulation. Indole-based SERMs such as bazedoxifene have a 2-phenyl ring system that serves as a core binding unit. Other classes include benzopyrans and naphthalenes (eg, lasofoxifene). In this review article, I will discuss raloxifene and three new SERMs--arzoxifene, bazedoxifene, and lasofoxifene--that have been recently studied. I will discuss their effect on bone, breast, and the cardiovascular system, as well as on safety.