Women’s Health

Hormone-Related and Drug-Induced Osteoporosis: A Cellular and Molecular Overview

Osteoporosis resulting from an imbalance of bone turnover between resorption and formation is a critical health issue worldwide. Estrogen deficiency following a nature aging process is the leading cause of hormone-related osteoporosis for postmenopausal women, while glucocorticoid-induced osteoporosis remains the most common in drug-induced osteoporosis. Other medications and medical conditions related to secondary osteoporosis include proton pump inhibitors, hypogonadism, selective serotonin receptor inhibitors, chemotherapies, and medroxyprogesterone acetate. This review is a summary of the cellular and molecular mechanisms of bone turnover, the pathophysiology of osteoporosis, and their treatment. Nuclear factor-κβ ligand (RANKL) appears to be the critical uncoupling factor that enhances osteoclastogenesis. In contrast, osteoprotegerin (OPG) is a RANKL antagonist secreted by osteoblast lineage cells. Estrogen promotes apoptosis of osteoclasts and inhibits osteoclastogenesis by stimulating the production of OPG and reducing osteoclast differentiation after suppression of IL-1 and TNF, and subsequent M-CSF, RANKL, and IL-6 release. It can also activate the Wnt signaling pathway to increase osteogenesis, and upregulate BMP signaling to promote mesenchymal stem cell differentiation from pre-osteoblasts to osteoblasts rather than adipocytes. Estrogen deficiency leads to the uncoupling of bone resorption and formation; therefore, resulting in greater bone loss. Excessive glucocorticoids increase PPAR-2 production, upregulate the expression of Dickkopf-1 (DKK1) in osteoblasts, and inhibit the Wnt signaling pathway, thus decreasing osteoblast differentiation. They promote osteoclast survival by enhancing RANKL expression and inhibiting OPG expression. Appropriate estrogen supplement and avoiding excessive glucocorticoid use are deemed the primary treatment for hormone-related and glucocorticoid-induced osteoporosis. Additionally, current pharmacological treatment includes bisphosphonates, teriparatide (PTH), and RANKL inhibitors (such as denosumab). However, many detailed cellular and molecular mechanisms underlying osteoporosis seem complicated and unexplored and warrant further investigation.

A Comprehensive Review on Nutraceuticals: Therapy Support and Formulation Challenges

Nutraceuticals are the nourishing components (hybrid of nutrition and pharmaceuticals) that are biologically active and possess capability for maintaining optimal health and benefits. These products play a significant role in human health care and its endurance, most importantly for the future therapeutic development. Nutraceuticals have received recognition due to their nutritional benefits along with therapeutic effects and safety profile. Nutraceuticals are globally growing in the field of services such as health care promotion, disease reduction, etc. Various drug nutraceutical interactions have also been elaborated with various examples in this review. Several patents on nutraceuticals in agricultural applications and in various diseases have been stated in the last section of review, which confirms the exponential growth of nutraceuticals' market value. Nutraceuticals have been used not only for nutrition but also as a support therapy for the prevention and treatment of various diseases, such as to reduce side effects of cancer chemotherapy and radiotherapy. Diverse novel nanoformulation approaches tend to overcome challenges involved in formulation development of nutraceuticals. Prior information on various interactions with drugs may help in preventing any deleterious effects of nutraceuticals products. Nanotechnology also leads to the generation of micronized dietary products and other nutraceutical supplements with improved health benefits. In this review article, the latest key findings (clinical studies) on nutraceuticals that show the therapeutic action of nutraceutical's bioactive molecules on various diseases have also been discussed.

Osteoporosis Due to Hormone Imbalance: An Overview of the Effects of Estrogen Deficiency and Glucocorticoid Overuse on Bone Turnover

Osteoporosis is a serious health issue among aging postmenopausal women. The majority of postmenopausal women with osteoporosis have bone loss related to estrogen deficiency. The rapid bone loss results from an increase in bone turnover with an imbalance between bone resorption and bone formation. Osteoporosis can also result from excessive glucocorticoid usage, which induces bone demineralization with significant changes of spatial heterogeneities of bone at microscale, indicating potential risk of fracture. This review is a summary of current literature about the molecular mechanisms of actions, the risk factors, and treatment of estrogen deficiency related osteoporosis (EDOP) and glucocorticoid induced osteoporosis (GIOP). Estrogen binds with estrogen receptor to promote the expression of osteoprotegerin (OPG), and to suppress the action of nuclear factor-κβ ligand (RANKL), thus inhibiting osteoclast formation and bone resorptive activity. It can also activate Wnt/β-catenin signaling to increase osteogenesis, and upregulate BMP signaling to promote mesenchymal stem cell differentiation from pre-osteoblasts to osteoblasts, rather than adipocytes. The lack of estrogen will alter the expression of estrogen target genes, increasing the secretion of IL-1, IL-6, and tumor necrosis factor (TNF). On the other hand, excessive glucocorticoids interfere the canonical BMP pathway and inhibit Wnt protein production, causing mesenchymal progenitor cells to differentiate toward adipocytes rather than osteoblasts. It can also increase RANKL/OPG ratio to promote bone resorption by enhancing the maturation and activation of osteoclast. Moreover, excess glucocorticoids are associated with osteoblast and osteocyte apoptosis, resulting in declined bone formation. The main focuses of treatment for EDOP and GIOP are somewhat different. Avoiding excessive glucocorticoid use is mandatory in patients with GIOP. In contrast, appropriate estrogen supplement is deemed the primary treatment for females with EDOP of various causes. Other pharmacological treatments include bisphosphonate, teriparatide, and RANKL inhibitors. Nevertheless, more detailed actions of EDOP and GIOP along with the safety and effectiveness of medications for treating osteoporosis warrant further investigation.

Isoquercitrin promotes the osteogenic differentiation of osteoblasts and BMSCs via the RUNX2 or BMP pathway

AIM

Isoquercitrin is widely present in fruits, vegetables and medicinal herbs. As a natural phytoestrogen, isoquercitrin has been considered a possible osteoporosis prevention option to avoid the risk of hormone therapy.

MATERIALS AND METHODS

The cell proliferation of osteoblasts and bone mesenchymal stem cells (BMSCs) was examined by cell counting kit-8 (CCK-8). The osteogenic differentiation was evaluated by real-time qPCR, ALP staining and Alizarin Red S staining. Small interfering RNA (siRNA) was used to knockdown the expression of runt-related transcription factor 2 (RUNX2).

RESULTS

The cell proliferation of osteoblasts and BMSCs was promoted by isoquercitrin at low concentrations. High concentrations of isoquercitrin promoted the osteogenic differentiation via RUNX2 expression in osteoblasts and via the bone morphogenetic protein (BMP) pathway in BMSCs. Inhibition of RUNX2 expression in osteoblasts by siRNA or addition of noggin to the culture medium of BMSCs reduced the effects of osteogenic differentiation induced by isoquercitrin.

CONCLUSIONS

These data suggest that isoquercitrin is a natural potential osteoinductive compound and might be valuable for the prevention/treatment of bone disorders.

Differential analysis of quantitative proteome and acetyl-proteome profiling between premenopausal and postmenopausal ovarian tissues

BACKGROUND

Natural menopause is always accompanied by specific signs and symptoms, suggesting physiological changes in this peoriod. However, no systematic study has assessed the changes at molecular level in the ovaries during the menopausal transition so far. This study integrated quantitative proteome and acetyl-proteome to comprehensively uncover the changes of ovarian protein and protein-acetylation profiles in this transitional period. The findings would provide novel insights into the biology of menopause and help relieve and treat the associated signs and symptoms, further improving the women's health care.

METHODS

Freshly thawed ovarian tissue samples obtained from premenopausal and postmenopausal women were assessed with Tandem Mass Tags for the quantitative analysis of the global profile and acetyl-proteomes by 2-dimensional separation and LC-MS/MS.

RESULTS

Comprehensively, 4210 types of protein, with 3551 types quantifiable were detected. 3047 acetylated sites in 1583 types of protein with 2256 quantifiable in 1248 proteins were detected. By comparing the global and acetylated proteome profiles for postmenopausal women and premenopausal women, 151 types of proteins were found upregulated and 65 were downregulated, along with 23 acetylated sites upregulated and 220 sites downregulated. For Immune response, the complement and coagulation cascades plus the citrate cycle and cellular detoxification were found to be significantly enhanced, while the extracellular structure and matrix organization, ECM-receptor interactions plus the infections were markedly suppressed. In addition, the amino acids around the acetylated sites were enriched by motif analysis, which can help us uncover amino acid sequence and search for the specific target in the subsequent study.

CONCLUSION

Global and acetylated proteome Profiles in ovary differ between the premenopausal and postmenopausal groups. These proteomic-level changes may offer some potential biological markers to identify the pathological changes in ovary and help relieve and treat the associated signs and symptoms, and ultimately improve women's health care.