Therapeutic Treatments for Osteoporosis-Which Combination of Pills Is the Best among the Bad?

Wnt/β-catenin signaling pathway: proteins' roles in osteoporosis and cancer diseases and the regulatory effects of natural compounds on osteoporosis

Osteoblasts are mainly derived from mesenchymal stem cells in the bone marrow. These stem cells can differentiate into osteoblasts, which have the functions of secreting bone matrix, promoting bone formation, and participating in bone remodeling. The abnormality of osteoblasts can cause a variety of bone-related diseases, including osteoporosis, delayed fracture healing, and skeletal deformities. In recent years, with the side effects caused by the application of PTH drugs, biphosphonate drugs, and calmodulin drugs, people have carried out more in-depth research on the mechanism of osteoblast differentiation, and are actively looking for natural compounds for the treatment of osteoporosis. The Wnt/β-catenin signaling pathway is considered to be one of the important pathways of osteoblast differentiation, and has become an important target for the treatment of osteoporosis. The Wnt/β-catenin signaling pathway, whether its activation is enhanced or its expression is weakened, will cause a variety of diseases including tumors. This review will summarize the effect of Wnt/β-catenin signaling pathway on osteoblast differentiation and the correlation between the related proteins in the pathway and human diseases. At the same time, the latest research progress of natural compounds targeting Wnt/β-catenin signaling pathway against osteoporosis is summarized.

Mind Gaps and Bone Snaps: Exploring the Connection Between Alzheimer's Disease and Osteoporosis

PURPOSE OF REVIEW

This comprehensive review discusses the complex relationship between Alzheimer's disease (AD) and osteoporosis, two conditions that are prevalent in the aging population and result in adverse complications on quality of life. The purpose of this review is to succinctly elucidate the many commonalities between the two conditions, including shared pathways, inflammatory and oxidative mechanisms, and hormonal deficiencies.

RECENT FINDINGS

AD and osteoporosis share many aspects of their respective disease-defining pathophysiology. These commonalities include amyloid beta deposition, the Wnt/β-catenin signaling pathway, and estrogen deficiency. The shared mechanisms and risk factors associated with AD and osteoporosis result in a large percentage of patients that develop both diseases. Previous literature has established that the progression of AD increases the risk of sustaining a fracture. Recent findings demonstrate that the reverse may also be true, suggesting that a fracture early in the life course can predispose one to developing AD due to the activation of these shared mechanisms. The discovery of these commonalities further guides the development of novel therapeutics in which both conditions are targeted. This detailed review delves into the commonalities between AD and osteoporosis to uncover the shared players that bring these two seemingly unrelated conditions together. The discussion throughout this review ultimately posits that the occurrence of fractures and the mechanism behind fracture healing can predispose one to developing AD later on in life, similar to how AD patients are at an increased risk of developing fractures. By focusing on the shared mechanisms between AD and osteoporosis, one can better understand the conditions individually and as a unit, thus informing therapeutic approaches and further research. This review article is part of a series of multiple manuscripts designed to determine the utility of using artificial intelligence for writing scientific reviews.

Regulation of bone homeostasis by traditional Chinese medicine active scaffolds and enhancement for the osteoporosis bone regeneration

ETHNOPHARMACOLOGICAL RELEVANCE

The active ingredients of traditional Chinese medicine (TCM), such as naringin (NG), Eucommiol, isopsoralen, icariin, Astragalus polysaccharides, and chondroitin sulfate, contained in Drynariae Rhizoma, Eucommiae Cortex, Psoralea corylifolia, Herba Epimedii, Astragalus radix and deer antler, are considered promising candidates for enhancing the healing of osteoporotic defects due to their outstanding bone homeostasis regulating properties. They are commonly used to activate bone repair scaffolds.

AIM OF THE REVIEW

Bone repair scaffolds are inadequate to meet the demands of osteoporotic defect healing due to the lack of regulation of bone homeostasis. Therefore, selecting bone scaffolds activated with TCM to improve the therapeutic effect of repairing osteoporotic bone defects.

MATERIALS AND METHODS

To gather information on bone scaffold activated by traditional Chinese medicine, we conducted a thorough search of several scientific databases, including Google Scholar, Web of Science, Scifinder, Baidu Scholar, PubMed, and China National Knowledge Infrastructure (CNKI).

RESULTS

This review discusses the mechanism of TCM active ingredients in regulating bone homeostasis, including stimulating bone formation and inhibiting bone resorption process and the healing mechanism of traditional bone repair scaffolds activated by them for osteoporotic defect healing.

CONCLUSION

In general, the introduction of TCM active ingredients provides a novel therapeutic approach for modulating bone homeostasis and facilitating osteoporotic defect healing, and also offers a new strategy for design of other unconventional bone defect healing materials.

Exosomes: A New Hope for Angiogenesis-Mediated Bone Regeneration

Bone is a metabolically dynamic structure that is generally remodeled throughout the lifetime of an individual but often causes problems with increasing age. A key player for bone development and homeostasis, but also under pathological conditions, is the bone vasculature. This complex system of arteries, veins, and capillaries forms distinct structures where each subset of endothelial cells has important functions. Starting with the basic process of angiogenesis and bone-specific blood vessel formation, coupled with initial bone formation, the importance of different vascular structures is highlighted with respect to how these structures are maintained or changed during homeostasis, aging, and pathological conditions. After exemplifying the current knowledge on bone vasculature, this review will move on to exosomes, a novel hotspot of scientific research. Exosomes will be introduced starting from their discovery via current isolation procedures and state-of-the-art characterization to their role in bone vascular development, homeostasis, and bone regeneration and repair while summarizing the underlying signal transduction pathways. With respect to their role in these processes, especially mesenchymal stem cell-derived extracellular vesicles are of interest, which leads to a discussion on patented applications and an update on ongoing clinical trials. Taken together, this review provides an overview of bone vasculature and bone regeneration, with a major focus on how exosomes influence this intricate system, as they might be useful for therapeutic purposes in the near future.

From the Mind to the Spine: The Intersecting World of Alzheimer's and Osteoporosis

PURPOSE OF REVIEW

This comprehensive review delves into the intricate interplay between Alzheimer's disease (AD) and osteoporosis, two prevalent conditions with significant implications for individuals' quality of life. The purpose is to explore their bidirectional association, underpinned by common pathological processes such as aging, genetic factors, inflammation, and estrogen deficiency.

RECENT FINDINGS

Recent advances have shown promise in treating both Alzheimer's disease (AD) and osteoporosis by targeting disease-specific proteins and bone metabolism regulators. Monoclonal antibodies against beta-amyloid and tau for AD, as well as RANKL and sclerostin for osteoporosis, have displayed therapeutic potential. Additionally, ongoing research has identified neuroinflammatory genes shared between AD and osteoporosis, offering insight into the interconnected inflammatory mechanisms. This knowledge opens avenues for innovative dual-purpose therapies that could address both conditions, potentially revolutionizing treatment approaches for AD and osteoporosis simultaneously. This review underscores the potential for groundbreaking advancements in early diagnosis and treatment by unraveling the intricate connection between AD and bone health. It advocates for a holistic, patient-centered approach to medical care that considers both cognitive and bone health, ultimately aiming to enhance the overall well-being of individuals affected by these conditions. This review article is part of a series of multiple manuscripts designed to determine the utility of using artificial intelligence for writing scientific reviews.

Effects of stepwise administration of osteoprotegerin and parathyroid hormone-related peptide DNA vectors on bone formation in ovariectomized rat model

Osteoporosis is a metabolic bone disease that impairs bone mineral density, microarchitecture, and strength. It requires continuous management, and further research into new treatment options is necessary. Osteoprotegerin (OPG) inhibits bone resorption and osteoclast activity. The objective of this study was to investigate the effects of stepwise administration of OPG-encoded minicircles (mcOPG) and a bone formation regulator, parathyroid hormone-related peptide (PTHrP)-encoded minicircles (mcPTHrP) in osteoporosis. The combined treatment with mcOPG and mcPTHrP significantly increased osteogenic marker expression in osteoblast differentiation compared with the single treatment groups. A model of postmenopausal osteoporosis was established in 12-week-old female rats through ovariectomy (OVX). After 8 weeks of OVX, mcOPG (80 µg/kg) was administered via intravenous injection. After 16 weeks of OVX, mcPTHrP (80 µg/kg) was injected once a week for 3 weeks. The bone microstructure in the femur was evaluated 24 weeks after OVX using micro-CT. In a proof-of-concept study, stepwise treatment with mcOPG and mcPTHrP on an OVX rat model significantly improved bone microstructure compared to treatment with mcOPG or mcPTHrP alone. These results suggest that stepwise treatment with mcOPG and mcPTHrP may be a potential treatment for osteoporosis.

Novel Osteoporosis Therapeutic Targets Derived from Medical Biotechnology

The Article Abstract is not available.

17β-Estradiol-Loaded Exosomes for Targeted Drug Delivery in Osteoporosis: A Comparative Study of Two Loading Methods

Purpose

Exosomes are natural nanoparticles that participate in intercellular communication through molecular transport. Recently, due to their membrane vesicular structure and surface proteins, exosomes have been used extensively in the research field of drug delivery. Osteoporosis is an inflammation in which the cellular balance of bone tissue is disturbed that reduces bone density and making bone prone to abnormal fractures with small amount of force. Utilizing estrogen is one of the main therapeutic strategies for osteoporosis. Despite the positive effects of estrogen on bone tissue, changes in the natural estrogen levels of the body can cause a number of diseases such as different types of cancer. Therefore, designing a therapeutic system which controls more accurate tissue targeting of estrogen seems to be a rational and promising practical approach.

Methods

In this study, bone marrow mesenchymal stem cells (BMMSCs)-derived exosomes were loaded by estradiol using two different methods of drug loading, namely incubation and sonication methods and then the survival effects of the drug loaded exosomes on BMMSCs was investigated.

Results

Examination of size, shape, and surface factors of exosomes in different states (pure exosomes and drug-loaded exosomes) showed that the round morphology of exosomes was preserved in all conditions. However, the particles size increased significantly when loaded by sonication method. The increased survival of BMMSCs was noted with estradiol-loaded exosomes when compared to the control group.

Conclusion

The results suggest that estradiol-loaded exosomes have potential to be used as nano-drug carriers in the treatment of osteoporosis.

The beneficial effects of simultaneous supplementation of Lactobacillus reuteri and calcium fluoride nanoparticles on ovariectomy-induced osteoporosis

BACKGROUND

The development of new strategies to inhibit and/or treat osteoporosis as a chronic systemic disease is one of the most crucial topics. The present study aimed to investigate the simultaneous effects of calcium fluoride nanoparticles (CaF2 NPs) and lactobacillus reuteri ATCC PTA 6475 (L. reuteri) against osteoporosis in an ovariectomized rat model (OVX).

METHODS

In this study, 18 matured Wistar female rats were randomly assigned into 6 groups, including control, OVX, sham, OVX + L. reuteri, OVX + CaF2 NPs, and OVX + L. reuteri + CaF2 NPs. We used OVX rats to simulate post-menopausal osteoporosis, and the treatments were begun two weeks before OVX and continued for four weeks. All groups' blood samples were collected, and serum biomarkers (estrogen, calcium, vitamin D3, and alkaline phosphatase (ALP)) were measured. The tibia and Femur lengths of all groups were measured. Histopathological slides of tibia, kidney, and liver tissues were analyzed using the Hematoxylin and Eosin staining method.

RESULTS

Our results revealed that dietary supplementation of L. reuteri and CaF2 NPs in low doses for 6 weeks did not show adverse effects in kidney and liver tissues. The tibial and femoral lengths of OVX rats as well as the population of osteoblasts and osteocytes and newly generated osteoid in the tibia remarkably increased in the combination therapy group. Moreover, there was a significant increase in serum estrogen levels and a significant decrease in serum calcium and alkaline phosphatase levels in combination treatment groups compared to the OVX groups not receiving the diet.

CONCLUSIONS

Our results suggest the favorable effects of the simultaneous supplementation of L. reuteri and CaF2 NP to reduce post-menopausal bone loss.

Curculigo orchioides polysaccharide COP70-1 stimulates osteogenic differentiation of MC3T3-E1 cells by activating the BMP and Wnt signaling pathways

The crude polysaccharide CO70 isolated from Curculigo orchioides could alleviate ovariectomy-induced osteoporosis in rats. To clarify the bioactive components, a new heteropolysaccharide (COP70-1) was purified from CO70 in this study, which was consisted of β-D-Manp-(1→, →4)-α-D-Glcp-(1→, →4)-β-D-Manp-(1→, →3,4)-β-D-Manp-(1→, →4,6)-β-D-Manp-(1→, and →4,6)-α-D-Galp-(1→. COP70-1 significantly promoted the osteoblastic differentiation of MC3T3-E1 cells through improving alkaline phosphatase activity, the deposition of calcium as well as up-regulating the expression of osteogenic markers (RUNX2, OSX, BSP, OCN, and OPN). Furthermore, COP70-1 stimulated the expression of critical transcription factors of the BMP and Wnt pathways, including BMP2, p-SMAD1, active-β-catenin, p-GSK-3β, and LEF-1. In addition, LDN (BMP pathway inhibitor) and DKK-1 (Wnt pathway inhibitor) suppressed the COP70-1-induced osteogenic differentiation of MC3T3-E1 cells. Therefore, COP70-1 was one of the bioactive constituents of C. orchioides for targeting osteoblasts to treat osteoporosis by triggering BMP/Smad and Wnt/β-catenin pathways.

INSULIN RESISTANCE AND PATHOGENESIS OF POSTMENOPAUSAL OSTEOPOROSIS

Osteoporosis (OP) is a disease predisposing postmenopausal women to fractures, and often accompanied by insulin resistance (IR) and metabolic syndrome (MetS). Previous studies provided contradictory results concerning prevalence of MetS in postmenopausal OP. To better understand the pathogenesis of IR, we reviewed cellular and molecular aspects and systematically reviewed studies providing homeostasis model assessment (HOMA) index. Bone is an active endocrine organ maintaining its integrity by orchestrated balance between bone formation and resorption. Both osteoblasts and osteoclasts contain receptors for insulin and insulin-like growth factor-1 (IGF-1) operating in skeletal development and in the adult life. Defects in this system generate systemic IR and bone-specific IR, which in turn regulates glucose homeostasis and energy metabolism through osteocalcin. Examination of genetic syndromes of extreme IR revealed intriguing features namely high bone mineral density (BMD) or accelerated growth. Studies of moderate forms of IR in postmenopausal women reveal positive correlations between HOMA index and BMD while correlations with osteocalcin were rather negative. The relation with obesity remains complex involving regulatory factors such as leptin and adiponectin to which the contribution of potential genetic factors and in particular, the correlation with the degree of obesity or body composition should be added.

Advances in materials-based therapeutic strategies against osteoporosis

Osteoporosis is caused by the disruption in homeostasis between bone formation and bone resorption. Conventional management of osteoporosis involves systematic drug administration and hormonal therapy. These treatment strategies have limited curative efficacy and multiple adverse effects. Biomaterials-based therapeutic strategies have recently emerged as promising alternatives for the treatment of osteoporosis. The present review summarizes the current status of biomaterials designed for managing osteoporosis. The advantages of biomaterials-based strategies over conventional systematic drug treatment are presented. Different anti-osteoporotic delivery systems are concisely addressed. These materials include injectable hydrogels and nanoparticles, as well as anti-osteoporotic bone tissue engineering materials. Fabrication techniques such as 3D printing, electrostatic spinning and artificial intelligence are appraised in the context of how the use of these adjunctive techniques may improve treatment efficacy. The limitations of existing biomaterials are critically analyzed, together with deliberation of the future directions in biomaterials-based therapies. The latter include discussion on the use of combination strategies to enhance therapeutic efficacy in the osteoporosis niche.

Methyltransferase-like 3 modulates osteogenic differentiation of adipose-derived stem cells in osteoporotic rats

BACKGROUND

Osteoporosis (OP) is a metabolic bone disease involving reduced bone mass. Adipose-derived stem cells (ASCs) play an important role in bone regeneration. Emerging evidence suggests that methyltransferase-like 3 (METTL3) plays a significant role in bone development and metabolism. Therefore, this study investigates changes to METTL3 in the osteogenic differentiation of adipose stem cells in osteoporotic rats (OP-ASCs) and explores ways to enhance their osteogenic ability.

METHODS

An animal model of osteoporosis was established by removing both ovaries in rats. Real-time PCR and western blotting were performed to detect the expression of METTL3 and bone-related molecules, including runt-related transcription factor 2 (Runx2) and osteopontin (Opn). Furthermore, alkaline phosphatase staining was used to confirm the osteogenic potential of stem cells. Mettl3 small interfering RNA and Mettl3 overexpression lentivirus were used to assess the role of METTL3 in osteogenic differentiation of ASCs and OP-ASCs.

RESULTS

The osteogenic differentiation capacity and Mettl3 expression significantly decreased in OP-ASCs. Moreover, Mettl3 silencing down-regulated the osteogenic ability of ASCs, and overexpression of Mettl3 recovered the impaired osteogenic capacity in OP-ASCs in vitro.

CONCLUSION

The Mettl3 expression levels and osteogenic potential of OP-ASCs decreased. However, overexpression of METTL3 rescued the osteogenic ability of OP-ASCs, providing a new target for treatment of osteoporotic bone defects.

Pulsed electromagnetic field attenuates bone fragility in estrogen-deficient osteoporosis in rats

BACKGROUND

The pulsed electromagnetic fields (PEMFs) seem effective in increasing bone mineral density and promoting osteogenesis and bone healing.

OBJECTIVE

To examine the effect of two different modalities of PEMFs therapy in comparison with the recommended pharmacological treatment on experimental osteoporosis in rats.

METHODS

The experimental model of estrogen-deficient osteoporosis induced by ovariectomy was used in this study. The animals were exposed to PEMFs of various frequencies (40 Hz and 25 Hzk), intensities (10 mT and 36.4 μT), lengths of exposure, and the effects were compared with the standard treatment with pamidronate, vitamin D, and calcium supplementation.

RESULTS

The application of PEMF40Hz, significantly reduced the osteoporotic bone loss in female rats that were confirmed with biochemical, biomechanical, and histological analyses. These effects were more pronounced than in osteoporotic animals treated with pamidronate, vitamin D, and calcium supplementation. On the contrary, the exposure to PEMF25Hz did not show restorative effects but led to further progression of osteoporosis.

CONCLUSION

The exposure to PEMF40Hz, significantly restored osteoporosis and attenuated bone fragility in comparison to the rats exposed to PEMF25Hz or those treated with pamidronate, vitamin D, and calcium supplementation.

Characteristics and osteogenic mechanism of glycosylated peptides-calcium chelate

Finding effective practical components to promote bone mineralization from the diet has become an effective method to regulate bone mass. In this study, peptides-calcium chelate derived from Crimson Snapper scales protein hydrolysates (CSPHs), and xylooligosaccharide (XOS)-peptides-calcium chelate prepared by transglutaminase (TGase) pathway, named CSPHs-Ca and XOS-CSPHs-Ca-TG, were used to explore the effects of glycosylation on their structural properties and osteogenic activity in vitro. Results showed that XOS-CSPHs-Ca-TG had better calcium phosphate crystallization inhibition activity with more unified structures than CSPHs-Ca, and could effectively maintain a stable calcium content in the gastrointestinal tract. Meanwhile, the glycosylated peptide-calcium chelate could accelerate the calcium transport efficiency in the Caco-2 cell monolayer, up to 3.54 folds of the control group. Moreover, XOS-CSPHs-Ca-TG exhibited prominent osteogenic effects by promoting the proliferation of MC3T3-E1 cells, increasing the secretion of osteogenic related factors, and accelerating the formation of intracellular mineralized nodules. RT-qPCR results further confirmed that this beneficial effect of XOS-CSPHs-Ca-TG was achieved by activating the Wnt/β-catenin signaling pathway. These results suggested that glycosylation might be a promising method for optimizing structural properties and osteogenic activity of peptide-calcium chelate.

Dual Targeting Anti-Osteoporotic Therapy through Potential Nanotherapeutic Approaches

Osteoporosis is characterised by a major public health burden, particularly taking into account the ageing global population. Therapeutic modalities for osteoporosis are categorised on the basis of their effect on bone remodeling: antiresorptive agents and anabolic agents. Anabolic drugs are favoured as they promote the formation of new bone, whereas antiresorptive drugs terminate the further deterioration of bone. Non-specific delivery of anabolic agents results in prolonged kidney exposure causing malignant hypercalcemia, whereas antiresorptive agents and bisphosphonates may produce osteonecrosis of the jaw. Several clinical trials have been reported for combinational therapy of anabolic agents and antiresorptive agents for osteoporosis. However, none of them have proven their cumulative effectiveness in the treatment of disease. The present work emphasizes on dual-targeting drug delivery approach comprising of bone anabolic and antiresorptive agents that would deliver the therapeutic agents to both the zones of bone simultaneously. The anticipated pioneering delivery approach will intensify the explicit interaction between the therapeutic agent and bone surfaces separately without developing severe adverse effects and improve the osteoporotic therapy effectively compared to non-targeted drug delivery.

Effect of hydrogen sulphide containing mineral water on experimental osteoporosis in rats

Background/Aim: Sulphur mineral water is widely used in the treatment of musculoskeletal diseases. Hydrogen sulphide is an important regulator of bone metabolism and its application in the treatment of osteoporosis is intensively researched. The aim of this study was to analyse biochemical and histological effects of H2S containing mineral water of "Mlječanica" spring on ovariectomy-induced experimental osteoporosis in rats. Methods: In this experiment a 14-week-old Wistar female rats were used. The animals undergone bilateral ovariectomy (OVX groups) as an experimental model for oestrogen-deficient osteoporosis. After six weeks, animals were divided into control and the experimental group. Rats from the experimental group treated with H2S (SW group) containing mineral water ad libitum during five weeks. Biochemical parameters for monitoring sulphur water effects were concentration in serum of osteocalcin, alkaline phosphatase, calcium and phosphorus. Histological analyses of the left tibia coloured with haematoxylin-eosin were carried out. Results: Regarding the biochemical parameters, a statistically significant increase was observed in the OVX group for osteocalcin, alkaline phosphatase calcium and phosphorus compared to the sham-operated (CNT) group (p < 0.01). In SW + OVX, alkaline phosphatase was statistically significantly decreased (p < 0.01) and serum osteocalcin and phosphorus increased (p < 0.01). Calcium values were increased without significance. In the OVX + SW group, histological analyses showed numerous osteoblasts along the trabecular endosteum and the growth of young chondrocytes in the central bone zone and their migration to the peripheral parts. Conclusion: Drinking the H2S containing "Mlječanica" mineral water has led to decreased alkaline phosphatase, increased osteocalcin and phosphorus concentration in serum and stimulated the bone reparation in osteoporotic rats.