Effects of Brucine on the OPG/RANKL/RANK Signaling Pathway in MDA-MB-231 and MC3T3-E1 Cell Coculture System

Bencaosome [16:0 Lyso PA+XLGB28-sRNA] improves osteoporosis by simultaneously promoting osteogenesis and inhibiting osteoclastogenesis in mice

Osteoporosis (OP) is a systemic metabolic bone disease resulting in reduced bone strength and increased susceptibility to fractures, making it a significant public health and economic problem worldwide. The clinical use of anti-osteoporosis agents is limited because of their serious side effects or the high cost of long-term use. The Xianlinggubao (XLGB) formula is an effective traditional Chinese herbal medicine commonly used in orthopedics to treat osteoporosis; however, its mechanism of action remains unclear. In this study, we screened 40 small RNAs derived from XLGB capsules and found that XLGB28-sRNA targeting TNFSF11 exerted a significant anti-osteoporosis effect in vitro and in vivo by simultaneously promoting osteogenesis and inhibiting osteoclastogenesis. Oral administration of bencaosome [16:0 Lyso PA+XLGB28-sRNA] effectively improved bone mineral density and reduced the damage to the bone microstructure in mice. These results suggest that XLGB28-sRNA may be a novel oligonucleotide drug that promotes osteogenesis and inhibits osteoclastogenesis in mice.

Review on effects and mechanisms of plant-derived natural products against breast cancer bone metastasis

Bone metastasis is the prevalent form of metastasis in breast cancer, resulting in severe pain, pathological fractures, nerve compression, hypercalcemia, and other complications that significantly impair patients' quality of life. The infiltration and colonization of breast cancer (BC) cells in bone tissue disrupt the delicate balance between osteoblasts and osteoclasts within the bone microenvironment, initiating a vicious cycle of bone metastasis. Once bone metastasis occurs, conventional medical therapy with bone-modifying agents is commonly used to alleviate bone-related complications and improve patients' quality of life. However, the utilization of bone-modifying agents may cause severe drug-related adverse effects. Plant-derived natural products such as terpenoids, alkaloids, coumarins, and phenols have anti-tumor, anti-inflammatory, and anti-angiogenic pharmacological properties with minimal side effects. Certain natural products that exhibit both anti-breast cancer and anti-bone metastasis effects are potential therapeutic agents for breast cancer bone metastasis (BCBM). This article reviewed the effects of plant-derived natural products against BCBM and their mechanisms to provide a reference for the research and development of drugs related to BCBM.

Regulation of bone and fat balance by Fructus Ligustri Lucidi in ovariectomized mice

CONTEXT

Fructus Ligustri Lucidi (FLL), a commonly used herb of traditional Chinese medicine (TCM), is the fruit of Ligustrum lucidum Ait. (Oleaceae). The ethanol extract of FLL is a potential candidate for preventing and treating postmenopausal osteoporosis (PMOP) by nourishing the liver and kidneys.

OBJECTIVE

This study determines whether an ethanol extract of FLL has anti-osteoporotic effects in ovariectomized (OVX) mice and explores the underlying mechanism.

MATERIALS AND METHODS

The OVX model of eight-week-old C57BL/6J female mice was taken, and ovariectomy was used as PMOP. Mice were divided into five groups: sham-operated group (n = 10), OVX group (n = 10), OVX + E₂ group (n = 10; 0.039 mg/kg), OVX + FLL group (n = 10; 2 g/kg) and OVX + FLL group (n = 10; 4 g/kg). Mice were treated by gavage with FLL or CMCNa once daily for 8 weeks. We harvested uteri, femur, and tibias from mice; bone mineral density (BMD) and bone microstructure were obtained by X-ray absorptiometry and micro-CT. Furthermore, the effect of FLL on the balance of osteoblast and adipocyte differentiation was investigated using bone marrow mesenchymal stem cells (BMMSCs).

RESULTS

The results indicated that FLL did not affect OVX-induced estradiol reduction. Compared with OVX mice, FLL significantly increased BMD (63.54 vs. 61.96), Conn. D (86.46 vs. 57.00), and left tibial strength (13.91 vs. 11.27), decreased Tb. Sp (0.38 vs. 0.44) and body fat content (4.19% vs. 11.24%). FLL decreased osteoclast activity and enhanced RUNX2 expression; inhibited perilipin peroxisome proliferator-activated receptor gamma (PPARγ) expression and adipocyte differentiation from BMMSCs.

CONCLUSIONS

FLL prevented additional bone loss and improved bone microstructure in OVX mice by modulating bone and fat balance, suggesting that FLL might be a therapeutic agent for PMOP.

The optimized drug delivery systems of treating cancer bone metastatic osteolysis with nanomaterials

Some cancers such as human breast cancer, prostate cancer, and lung cancer easily metastasize to bone, leading to osteolysis and bone destruction accompanied by a complicated microenvironment. Systemic administration of bisphosphonates (BP) or denosumab is the routine therapy for osteolysis but with non-negligible side effects such as mandibular osteonecrosis and hypocalcemia. Thus, it is imperative to exploit optimized drug delivery systems, and some novel nanotechnology and nanomaterials have opened new horizons for scientists. Targeted and local drug delivery systems can optimize biodistribution depending on nanoparticles (NPs) or microspheres (MS) and implantable biomaterials with the controllable property. Drug delivery kinetics can be optimized by smart and sustained/local drug delivery systems for responsive delivery and sustained delivery. These delicately fabricated drug delivery systems with special matrix, structure, morphology, and modification can minimize unexpected toxicity caused by systemic delivery and achieve desired effects through integrating multiple drugs or multiple functions. This review summarized recent studies about optimized drug delivery systems for the treatment of cancer metastatic osteolysis, aimed at giving some inspiration in designing efficient multifunctional drug delivery systems.

Phosvitin phosphopeptides produced by pressurized hea-trypsin hydrolysis promote the differentiation and mineralization of MC3T3-E1 cells via the OPG/RANKL signaling pathways

Phosvitin (PV) from egg yolk is an excellent substrate for the production of phosphopeptides, which have a strong calcium chelating capacity and promoting calcium absorption and bone mineralization. This study investigated the effect of PV hydrolysates produced using a effective preparation method (high temperature (121°C) and mild pressure (0.1 MPa), HTMP) or HTMP pretreatment and trypsin hydrolysis combination (HTMP-PV18) on the physiology of an osteoblast MC3T3-E1 cells line. The proliferation, apoptosis, and differentiation of MC3T3-E1 cells were analyzed using the CCK-8, flow cytometry, and RT-PCR reactions, respectively. Both the HTMP-PV and HTMP-PV18 increased the proliferation, and inhibited the apoptosis of MC3T3-E1 cells significantly. The HTMP-PV increased the proliferation of MC3T3-E1 cells by 147.12 ± 2.11% and the HTMP-PV18 by 136.43 ± 4.51%. In addition, the HTMP-PV and HTMP-PV18 effectively promoted the expression of genes related to the OPG/RANKL signaling channel during cell differentiation. This indicated that both the HTMP-PV and HTMP-PV18 have the potential to promote bone mineralization by improving the proliferation and differentiation of osteoblastic cells.

Can injection of adipose stem cells to non-union zone increase bone union? Experimental rat study

Objectives

This study aims to evaluate the effects of local adipose stem cell injection on non-union and diabetic non-union of rat femurs.

Materials and methods

Forty-eight female Wistar albino rats (weighing mean 200 g and aged 8 weeks) were used in this study. The rats were divided into six groups. Group 1 was chosen as a reference for receptor activator of nuclear factor-kappa (k) B (RANK), receptor activator of nuclear factor-k B ligand (RANKL) and osteoprotegerin (OPG) genes and no femur osteotomy was performed in this group. Group 2 underwent femur osteotomy, the osteotomy was fixed with a 1.5 mm K-wire as retrograde from the knee joint, and no gap was left in the osteotomy line. In order to induce non-union, femurs underwent osteotomy fixed with K-wires in groups 3, 4, 5 and 6. In addition, the osteotomy line was measured as 1.8 mm gap with electronic calipers and the gap was fixed with U staple. Before osteotomy, streptozocin was injected intraperitoneally at a dose of 60 mg/kg in 0.1 mol/L citrate buffer solution (Ph 4.4) in groups 4 and 6, in order to induce diabetes mellitus. Left femur anteroposterior and lateral X-rays were taken 10 weeks after the operation and the union in group 2 and non-union in groups 3, 4, 5, and 6 were confirmed. To see if injection of adipose stem cells into the non-union site increases bone union, 2 mL 0.9% sodium chloride (NaCl) in groups 3 and 4 and 2×106 adipose stem cell in groups 5 and 6 were locally injected into the non-union area with fluoroscopy. Femur X-rays were taken eight weeks after the injection and all rats were sacrificed. Femurs of rats were removed for histopathological and gene expression evaluation.

Results

There were significant differences between the groups injected 0.9% NaCI and adipose stem cells in terms of bone healing according to radiological and histopathological evaluations (p<0.05). No statistically significant difference was observed between the groups in terms of gene expression levels.

Conclusion

According to the results of our study, local adipose stem cell injection has positive radiological and histopathological effects in diabetic and non-diabetic femoral non-unions, independently of RANK, RANKL, or OPG gene expression pathways.

Effect of Steroidal Hormone Pregnenolone on Proliferation and Differentiation of MC3T3-E1 Osteoblast like Cells

Background:

Bone remodeling is a complex process that includes continuous resorption by osteoclast cells and bone formation by osteoblast cells. Bone fragility is a common health issue of the elderly population, particularly in postmenopausal women. It has been established that steroidal hormones have an important role in bone homeostasis. Therefore hormone replacement therapy could have beneficial effects on bone health as compared to other treatments.

Objectives:

An imbalance between the rate of bone formation and bone resorption leads to the fragility of bones. During the current study, we aimed to explore the ability of pregnenolone (1) (PRE), on proliferation and differentiation of MC3T3-E1 cells. We further aimed to investigate the underlying mechanism of action for the anabolic effect of PRE (1).

Methods:

The effects of pregnenolone (1) on proliferation, differentiation, and mineralization of MC3T3 osteoblast-like cells were determined. Cell viability was analyzed using MTT assay and flow cytometry. ALP activity and alizarin staining were employed to evaluate the effect of pregnenolone on osteoblast differentiation. Moreover, western blot for analysis of certain important proteins, crucial for the regulation of bone homeostasis, such as BMP2 and RANKL, was also performed.

Results:

Our results showed that pregnenolone (1) at a concentration of 5 μM caused a significant (p< 0.05) rise in the growth of MC3T3-E1 cells, whereas a comparable effect was observed in osteoblast differentiating assays. A significant decrease in RANKL expression was observed at (0.04 – 1 .M). Our results, therefore, indicated the possible role of pregnenolone (1) in positive regulation of bone homeostasis by suppressing RANKL expression.

Conclusion:

Taken together, our results indicate that pregnenolone (1) has the potential to enhance osteoblast proliferation, as inferred from the increased number of cells. These results demonstrated that pregnenolone (1) could be a potential anabolic agent for the treatment of fragility related disorders.