Rat Model Of Postmenopausal Osteoporosis Research Articles

A Multifunctional Therapeutic Strategy Using P7C3 as A Countermeasure Against Bone Loss and Fragility in An Ovariectomized Rat Model of Postmenopausal Osteoporosis.

By 2060, an estimated one in four Americans will be elderly. Consequently, the prevalence of osteoporosis and fragility fractures will also increase. Presently, no available intervention definitively prevents or manages osteoporosis. This study explores whether Pool 7 Compound 3(P7C3) reduces progressive bone loss and fragility following the onset of ovariectomy (OVX)-induced osteoporosis. Results confirm OVX-induced weakened, osteoporotic bone together with a significant gain in adipogenic body weight. Treatment with P7C3 significantly reduced osteoclastic activity, bone marrow adiposity, whole-body weight gain, and preserved bone area, architecture, and mechanical strength. Analyses reveal significantly upregulated platelet derived growth factor-BB and leukemia inhibitory factor, with downregulation of interleukin-1 R6, and receptor activator of nuclear factor kappa-B (RANK). Together, proteomic data suggest the targeting of several key regulators of inflammation, bone, and adipose turnover, via transforming growth factor-beta/SMAD, and Wingless-related integration site/be-catenin signaling pathways. To the best of the knowledge, this is first evidence of an intervention that drives against bone loss via RANK. Metatranscriptomic analyses of the gut microbiota show P7C3 increased Porphyromonadaceae bacterium, Candidatus Melainabacteria, and Ruminococcaceae bacterium abundance, potentially contributing to the favorable inflammatory, and adipo-osteogenic metabolic regulation observed. The results reveal an undiscovered, and multifunctional therapeutic strategy to prevent the pathological progression of OVX-induced bone loss.

Eupatilin ameliorates postmenopausal osteoporosis via elevating microRNA-211-5p and repressing JAK2/STAT3 pathway.

Postmenopausal osteoporosis (PMOP) poses a significant threat to women's health worldwide. Eupatilin is a key bioactive component of the Chinese herbal medicine Artemisia asiatica Nakai. Recent research reports have proved the inhibitory function of Eupatilin in many diseases. MicroRNAs (miRNAs) are 21-23 nucleotide-long, single-stranded, noncoding RNA molecules generated endogenously, and many studies have indicated that miRNAs are involved in the development of osteoporosis. This study explored the role and potential mechanism of Eupatilin underlying PMOP. First, rats were given intragastric administration of Eupatilin every day and subcutaneous injections of oligonucleotides or plasmids that interfered with miR-211-5p or janus kinase 2 (JAK2) once a week. After 4 weeks, the PMOP rat model was established. Then, serum alkaline phosphatase, calcium, and phosphorus levels, as well as femur bone mineral density and biomechanical parameters, were detected. Hematoxylin-eosin staining and Masson staining were applied for detecting the pathological condition of femur, and immunohistochemical staining was for detecting osteocalcin. MC3T3-E1 cells were transfected with plasmid vectors interfering with miR-211-5p or JAK2; and cell viability, lactate dehydrogenase cytotoxicity, and cell mineralization were subsequently examined. The relationship between miR-211-5p and JAK2/signal transducer and activator of transcription 3 (STAT3) pathway was analyzed. The targeting relation between miR-211-5p and JAK2 was also verified. The experimental results revealed that Eupatilin improved the pathological conditions of PMOP rats by promoting the proliferation and mineralization of osteoblasts. MiR-211-5p was down-regulated and JAK2/STAT3 was upregulated in PMOP rats. Upregulation of miR-211-5p further improved the pathological conditions of PMOP rats based on Eupatilin treatment. MiR-211-5p inhibited the JAK2/STAT3 pathway. JAK2 offset the effects of elevated miR-211-5p on PMOP rats. Overall, Eupatilin attenuates PMOP through elevating miR-211-5p and repressing JAK2/STAT3 pathway, which suggests the utility of Eupatilin as a potential drug for POMP treatment.

Trehalose delays postmenopausal osteoporosis by enhancing AKT/TFEB pathway‑dependent autophagy flow in rats.

Osteoporosis is a systemic bone metabolic disorder that plagues the health and quality of life of the elderly. Autophagy plays an important role in bone formation while maintaining the homeostasis of the body. Trehalose is a mTOR-independent autophagy inducer, but to the best of our knowledge, there is no rat model of postmenopausal osteoporosis. The present study found that trehalose can delay postmenopausal osteoporosis in rats, which may be achieved by inducing and enhancing AKT/transcription factor EB pathway-dependent autophagy flow. The specific mechanism of its occurrence needs to be further studied. Trehalose-containing drugs are promising for delaying postmenopausal osteoporosis. Hematoxylin and eosin (H&E) staining, western blotting, micro computerized tomography (CT) scanning and Transmission electron microscopy were used to investigate the role of trehalose in postmenopausal osteoporosis rat model at protein, cell and histology aspects. According to the H&E staining results, the bone trabecular histological structure of the trehalose group was superior to that of the model group. The Micro CT scanning indicated the imaging structure of bone trabeculae in the trehalose group was superior to than that in the model group. Western blotting indicated the activation of autophagic flow in trehalose group, the autophagy degree of the trehalose group is greater than that of the model group; Transmission electron microscopy indicated the autophagy degree of the Trehalose group was greater than that of the model group under electron microscopy. Trehalose can delay postmenopausal osteoporosis in rats, which may be achieved by inducing and enhancing Akt/TFEB pathway-dependent autophagy flow.

Role of 17-β Estradiol and Ramipril in OPG/RANKL Pathway in a Rat Model of Post-Menopausal Osteoporosis

Role of 17-β Estradiol and Ramipril in OPG/RANKL Pathway in a Rat Model of Post-Menopausal Osteoporosis

Overall adjustment acupuncture improves osteoporosis and exerts an endocrine-modulating effect in ovariectomized rats.

Acupuncture is a widely practiced, convenient, and safe treatment modality within complementary and integrative medicine. Increasing studies have revealed the efficacy of acupuncture for the treatment of osteoporosis in both human and non-human subjects. The aim of the present study was to assess the improvement of osteoporosis after overall adjustment acupuncture (OA) as well as its endocrine-modulating effect in an ovariectomized rat model. In total, 32 female Sprague-Dawley (SD) rats were randomly divided into the sham, model, ovariectomy+estrogen (OVX+E), and OVX+OA (OVX+A) groups with eight rats in each group. The postmenopausal osteoporosis (PMOP) rat model was induced by bilateral ovariectomy. At 12 weeks after surgery, rats in the OVX+E group received estradiol (0.2 mg/kg/i.g./qod) for 12 weeks, and rats in the OVX+A group were treated with acupuncture at Zusanli (ST36), Shenshu (BL23), and Dazhu (BL11) points (qod) for 12 weeks. At the end of the treatment, all rats were sacrificed, and the body weight, uterus index, bone mineral density (BMD), bone mineral content (BMC), bone trabeculae structural parameters, femoral biomechanical properties, femoral histomorphology, and several hormone levels were examined. In OVX rats, OA abrogated the body weight gain and improved osteoporosis in terms of BMD, BMC, bone trabeculae structural parameters, bone strength, and bone tissue histomorphology. Moreover, OA modulated the serum levels of estradiol, corticotropin releasing hormone (CRH), adrenocorticotropic hormone (ACTH), and corticosterone (CORT). OA improves osteoporosis and exerts an endocrine-modulating effect in ovariectomized rats.

4D label-free quantitative proteomics analysis to screen potential drug targets of Jiangu Granules treatment for postmenopausal osteoporotic rats.

Background: Postmenopausal osteoporosis (PMOP) is a disease with a high prevalence in postmenopausal women and is characterized by an imbalance in bone metabolism, reduced bone mass, and increased risk of fracture due to estrogen deficiency. Jiangu granules (JG) is a compound prescription used in traditional Chinese medicine to treat PMOP. However, its definitive mechanism in PMOP is unclear. This study used a 4D label-free quantitative proteomics method to explore the potential therapeutic mechanism of JG in an ovariectomy (OVX) rats' model. Materials and methods: A rat model of PMOP was established by removing the ovaries bilaterally. Nine 3-month-old specific-pathogen-free female SD rats. The nine rats were randomly divided into 3 groups (n = 3 in each group): the sham-operated group (J), the ovariectomy group (NC), and the JG treatment (ZY) group. Proteins extracted from the bone tissue of the lumbar spine (L3, L4) of three groups of rats were analyzed by 4D label-free quantitative proteomics, and proteins differentially expressed after JG treatment and proteins differentially expressed after de-ovulation were intersected to identify proteins associated with the mechanism of PMOP by JG treatment. Result: There were 104 up-regulated and 153 down-regulated differentially expressed proteins (DEPs) in the J group vs. NC group, 107 up-regulated and 113 down-regulated DEPs in the J group vs. ZY group, and 15 up-regulated and 32 down-regulated DEPs in the NC group vs. ZY group. Six potential target proteins for JG regulation of osteoblast differentiation in OVX rats were identified by taking intersections of differential proteins in the J group vs. NC group and NC group vs. ZY group. Conclusion: JG may exert therapeutic effects by modulating the expression levels of target proteins associated with osteoblast differentiation to enhance osteoblast differentiation in OVX rats. These results further uncovered the target proteins and specific mechanisms of JG in treating PMOP, providing an experimental basis for the clinical application of JG in treating PMOP.

Zhuanggu Zhitong Capsule alleviates postmenopausal osteoporosis in ovariectomized rats by regulating autophagy through AMPK/mTOR signaling pathway.

BackgroundPostmenopausal osteoporosis (PMOP) is the most common primary osteoporosis, which is prone to fractures and affect the health and quality of life of the elderly and even shorten their lifetime. Traditional Chinese medicine can not only effectively improve osteoporosis and reduce fracture rate, but also have tonifying and analgesic effects. The purpose of this study was to investigate the effects of Zhuanggu Zhitong (ZGZT) Capsule on autophagy related genes and proteins in PMOP rats, so as to elucidate the molecular mechanism of tonifying deficiency and regulating stasis in the treatment of osteoporosis and analgesia.MethodsThe PMOP rat model was established by bilateral oophorectomy, and then the rats were randomly divided into control group, PMOP group, PMOP + ZGZT group and PMOP + E2 group. The changes of mechanical pain threshold of rats were detected by von Frey filaments, and the changes of mechanical pain threshold of rats in each group were compared. Computed tomography (CT) and dual-energy X-ray were used to measure the bone mineral density of lumbar bone tissue. Enzyme-linked immunosorbent assay (ELISA) and tartrate-resistant acid phosphatase (TRAP) staining were used to detect inflammatory factors and bone metabolism related indicators. Hematoxylin-eosin (HE) staining was used to observe the tissue morphology of lumbar vertebra tissue. Western blot (WB) and quantitative polymerase chain reaction (qPCR) were used to detect AMPK/mTOR pathway- and autophagy-related factor expression.ResultsZGZT can effectively restore the bone mineral density (BMD) of PMOP rats, improve the microstructure of lumbar vertebra of PMOP rats, restore the balance of bone metabolism, promote the expression of AMPK and autophagy related factors, inhibit the expression of mTOR and the release of inflammatory factors, and increase the mechanical pain threshold of PMOP rats, so as to effectively improve osteoporosis and relieving osteoporosis pain in PMOP rats.ConclusionsZGZT affects autophagy by regulating AMPK/mTOR pathway, restores the homeostasis of bone metabolism and inhibits the release of inflammatory factors. Moreover, the regulation of feedback pathways between bone metabolism and inflammatory factors finally plays the role of “bone strengthening” and “pain relieving”. ZGZT may be a new treatment for PMOP and relieving osteoporotic pain.

Combined Therapy of Yishen Zhuanggu Decoction and Caltrate D600 Alleviates Postmenopausal Osteoporosis by Targeting FoxO3a and Activating the Wnt/β-Catenin Pathway

Background Postmenopausal osteoporosis (PMO) is the most prevalent metabolic bone disease in women. Yishen Zhuanggu (YSZG) decoction and Caltrate D600 reportedly affects bone formation. This study aimed to investigate the efficacy and mechanism of YSZG decoction combined with Caltrate D600 in PMO treatment. Methods Ovariectomy-induced PMO rat model was treated with YSZG or/and Caltrate D600 for 12 weeks. Femur bone mineral density (BMD), osteoporosis-related protein expression, and serum parameters were measured. Pathological features of femur bone tissues were observed using hematoxylin and eosin staining. Serum levels of oxidative stress parameters were measured using corresponding commercial kits. The mRNA and protein expression of FoxO3a, Wnt, and β-catenin was detected using qRT-PCR and western blotting. Results The BMD and ultimate load of PMO rats were increased after treatment with YSZG. YSZG treatment promoted the bone trabeculae formation of PMO rats. YSZG treatment also induced bone differentiation and suppress oxidative stress in PMO rats, evidenced by the increased BALP, Runx2, OPG, SOD, and CAT levels, as well as the decreased TRACP 5b, RANKL, ROS, and MDA levels. Additionally, YSZG treatment downregulated the FoxO3a expression and upregulated the levels of Wnt and β-catenin in PMO rats. Caltrate D600 addition showed an auxiliary effect for YSZG. Conclusion YSZG decoction exerts the antiosteoporotic effect on PMO by restraining the FoxO3a expression and activating the Wnt/β-catenin pathway, which has an impressive synergistic effect with Caltrate D600.

Osteoprotective Effects in Postmenopausal Osteoporosis Rat Model: Oral Tocotrienol vs. Intraosseous Injection of Tocotrienol-Poly Lactic-Co-Glycolic Acid Combination.

Osteoporosis, the most common bone disease, is associated with compromised bone strength and increased risk of fracture. Previous studies have shown that oxidative stress contributes to the progression of osteoporosis. Specifically, for postmenopausal osteoporosis, the reduction in estrogen levels leads to increased oxidative stress in bone remodeling. Tocotrienol, a member of vitamin E that exhibits antioxidant activities, has shown potential as an agent for the treatment of osteoporosis. Most studies on the osteoprotective effects of tocotrienols had used the oral form of tocotrienols, despite their low bioavailability due the lack of transfer proteins and high metabolism in the liver. Several bone studies have utilized tocotrienol combined with a nanocarrier to produce a controlled release of tocotrienol particles into the system. However, the potential of delivering tocotrienol–nanocarrier combination through the intraosseous route has never been explored. In this study, tocotrienol was combined with a nanocarrier, poly lactic-co-glycolic acid (PLGA), and injected intraosseously into the bones of ovariectomized rats to produce targeted and controlled delivery of tocotrienol into the bone microenvironment. This new form of tocotrienol delivery was compared with the conventional oral delivery in terms of their effects on bone parameters. Forty Sprague–Dawley rats were divided into five groups. The first group was sham operated, while other groups were ovariectomized (OVX). Following 2 months, the right tibiae of all the rats were drilled at the metaphysis region to provide access for intraosseous injection. The estrogen group (OVX + ESTO) and tocotrienol group (OVX + TTO) were given daily oral gavages of Premarin (64.5 mg/kg) and annatto-tocotrienol (60 mg/kg), respectively. The locally administered tocotrienol group (OVX + TTL) was given a single intraosseous injection of tocotrienol–PLGA combination. After 8 weeks of treatment, both OVX + TTO and OVX + TTL groups have significantly lower bone markers and higher bone mineral content than the OVX group. In terms of bone microarchitecture, both groups demonstrated significantly higher trabecular separation and connectivity density than the OVX group (p < 0.05). Both groups also showed improvement in bone strength by the significantly higher stress, strain, stiffness, and Young’s modulus parameters. In conclusion, daily oral tocotrienol and one-time intraosseous injection of tocotrienol–PLGA combination were equally effective in offering protection against ovariectomy-induced bone changes.

The cross-talk between matrix metalloproteinase-9, RANKL/OPG system and cardiovascular risk factors in ovariectomized rat model of postmenopausal osteoporosis.

Epidemiology and pathogenesis of cardiovascular diseases (CVD) and osteoporosis are strikingly overlapping. This study presents matrix metalloproteinase-9 (MMP-9), as a simple molecular link more consistently associated with the pathophysiology of both osteoporosis and CVD risk factors. 40 adult female rats were randomly distributed into 4 groups [control sham-operated, untreated osteoporosis, carvedilol-treated osteoporosis and alendronate-treated osteoporosis]. After 8 weeks, blood samples were collected to estimate Lipid profile (Total cholesterol, HDL, Triglycerides), inflammatory markers (IL-6, TNF alpha, CRP and NO), and Bone turnover markers (BTM) (Alkaline phosphatase, osteocalcin and pyridinoline). The tibias were dissected to estimate MMP-9 and NF-kB gene expression, OPG, RANKL levels and for histological examination. Induction of osteoporosis resulted in a significant elevation in BTM, inflammatory markers and dyslipidemia. MMP-9 was significantly elevated and positively correlated with BTM, inflammation and dyslipidemia markers. Carvedilol and alendronate exerted a bone preservative role and attenuated dyslipidaemia and inflammation in accordance with their respective effect on MMP-9.

Positive effect of compound amino acid chelated calcium from the shell and skirt of scallop in an ovariectomized rat model of postmenopausal osteoporosis.

Osteoporosis has become an important public health issue with the increase of aging population, and afflicts millions of people worldwide, particularly elderly or postmenopausal women. In the present study, we prepared compound amino acid chelated calcium (CAA-Ca) from processing by-products of Chlamys farreri, and evaluated its effect on postmenopausal osteoporosis with an ovariectomized (OVX) rat model. A 60-day treatment of OVX rats with CAA-Ca significantly enhanced the bone mineral density (BMD) and the bone calcium content. Meanwhile, some bone morphometric parameters, trabecular bone number (Tb.N), trabecular bone volume fraction (BV/TV), trabecular bone thickness (Tb.Th) and cortical bone wall thickness (Ct.Th), were also increased by 8.20%, 118.18%, 32.99% and 19.10%, respectively. In addition, the alkaline phosphatase (ALP) levels in serum were significantly reduced after CAA-Ca treatment, while the blood calcium levels were increased. Mechanistically, CAA-Ca down-regulated the levels of receptor activator of nuclear factor-κB (RANK) and receptor activator of nuclear factor-κB ligand (RANKL), and up-regulated osteoprotegerin (OPG) levels in osteoclasts, inhibiting bone resorption and bone loss. Meanwhile, CAA-Ca treatment raised β-catenin levels and lowered Dickkopf1 (DKK1) levels in the Wnt signaling pathway of osteoblasts, which can promote calcium absorption and bone formation. The results suggested that CAA-Ca promoted bone formation, inhibited bone resorption and improved bone microstructure. Therefore, this study contributes to the potential application of CAA-Ca as a functional food resource in the treatment of postmenopausal osteoporosis. © 2021 Society of Chemical Industry.

Calcium-Enriched Pumpkin Affects Serum Leptin Levels and Fat Content in a Rat Model of Postmenopausal Osteoporosis.

Because the world’s population is deficient in dietary calcium, it is important to search for new sources of this essential mineral for the bones and the entire body. One of the innovative foods that could act as such a source is pumpkin enriched with calcium lactate by means of osmotic dehydration. Providing the body with easily absorbable calcium may have beneficial effects on the reconstruction of bone tissue. Postmenopausal osteoporosis is associated with body weight and fat mass gain, and the aim of the present study was to evaluate the effect of consuming enriched pumpkin on the levels of adipokines and cytokines produced by the adipose tissue. This study was conducted on 12-month-old female Wistar rats that received nutritional intervention for 12 weeks. After termination of the rats, the levels of leptin, adiponectin, interleukin 31 and interleukin 33 in serum and adipose tissue were determined, and the femurs were examined histopathologically. It was demonstrated that calcium-enriched pumpkin reduced bone marrow femoral adipocytes and also markedly decreased serum leptin levels in groups of rats after ovariectomy, which was associated with a decrease of fat content. Additionally, it seems that calcium-enriched pumpkin may reduce body weight gain often observed after menopause.

MicroRNA-182 inhibits osteogenic differentiation of bone marrow mesenchymal stem cells by targeting Smad1.

The present study aimed to screen abnormally expressed microRNAs (miRs/miRNAs) in patients with postmenopausal osteoporosis (POP) and explore their mechanisms via functional verification. Bone marrow mesenchymal stem cells (BMSCs) were extracted from healthy controls and patients with POP. Differences in osteogenic differentiation and proliferation of human BMSCs were compared between the two groups using Cell Counting Kit-8 (CCK-8) assay and alizarin red staining. A rat model of POP was established. Compared with patients with POP, human BMSCs in healthy controls had significantly enhanced viability at 24, 36, 48 and 72 h. The results of alizarin red staining revealed that the deposition of calcium minerals in human BMSCs were significantly lower in patients with POP. Based on miRNA microarray and reverse transcription-quantitative polymerase chain reaction (PCR) results, the expression levels of miR-7010 and miR-467c decreased, while miR-132 and miR-182 expression increased in the human BMSCs of patients with POP. Alizarin red staining showed that miR-182 markedly suppressed the osteogenic differentiation of primary rat BMSCs in rats. Western blotting and immunofluorescence assay revealed that miR-182 inhibited the expression of osteogenesis markers runt-related transcription factor 2, osterix and actinin-associated LIM protein. The results of the luciferase reporter assay showed that Smad1 is the direct target of miR-182. In rat primary BMSCs, Smad1 overexpression abolished the inhibitory effect of miR-182 on osteogenesis, indicating that miR-182 inhibits osteogenic differentiation of primary rat BMSCs in rats by targeting Smad1. Finally, in vivo experimental results showed that the biomechanical characteristics of bone tissues in POP rats were significantly enhanced by miR-182 inhibition, while they were significantly weakened by miR-182 overexpression. MiR-182 inhibits osteogenic differentiation of rat BMSCs, thus aggravating POP in rats.

Extracellular vesicles from GPNMB-modified bone marrow mesenchymal stem cells attenuate bone loss in an ovariectomized rat model

AimsThe efficacy of anti-osteoporotic treatments is still limited. Our study aimed to investigate the effect of extracellular vesicles (EVs) derived from bone marrow-derived MSCs (BMSCs) overexpressing glycoprotein non-melanoma clone B (GPNMB) on osteoporosis (OP). Main methodsLentiviral vector for GPNMB overexpression or its negative control was generated and transfected into BMSCs. EVs enriched with GPNMB (GPNMB-EVs) were extracted from GPNMB-modified BMSC-conditioned medium and then identified. Cellular uptake and proliferation were analyzed using the Dil-labeled assay and CCK-8 assay, respectively. Cytochemical staining, western blot, and RT-qPCR analysis were performed to assess the effect of GPNMB-EVs on osteogenic differentiation of BMSCs in vitro. Dickkopf-1 (DKK1) as the inhibitor was applied to explore the Wnt/β-catenin signaling pathway involved in the GPNMB-EV-induced osteogenic differentiation. In vivo experiments were conducted using an ovariectomized (OVX) rat model of postmenopausal osteoporosis, and then assessed the effect of GPNMB-EVs by micro-CT, and histological and immunohistochemical assays. Key findingsGPNMB-EVs were taken up by BMSCs, and they noticeably promoted the proliferation of BMSCs. Additionally, GPNMB-EVs activated the Wnt/β-catenin signaling to stimulate osteogenesis in BMSCs. In vivo examination showed that GPNMB-EVs remarkably improved trabecular bone regeneration and alleviated the osteoporotic phenotype in the OVX-induced rat model of OP. SignificanceEVs derived from GPNMB-modified BMSCs significantly stimulated the proliferation and osteogenic differentiation of BMSCs via the activation of Wnt/β-catenin signaling and attenuated the bone loss in the OVX-induced rat model of OP. Our findings suggest the promising potential of GPNMB-EVs as cell-free therapy for the treatment of OP.

Shockwave Therapy Modulates the Expression of BMP2 for Prevention of Bone and Cartilage Loss in the Lower Limbs of Postmenopausal Osteoporosis Rat Model

Osteoporosis (OP) causes bone loss and weakness, increasing the risk of bone fracture. In this study, rats were divided into Sham, OP, SW(F) (0.25 mJ/mm2 with 1600 impulses to the left medial femur), and SW(T) (0.25 mJ/mm2 with 1600 impulses to the left medial tibia). The bone strength results following SW(T) were better than SW(F) in the modulus, extension at peak load, handleability, and strain at break. SW(T) had the best prevention for bone loss in both lower limbs of ovariectomized (OVX) rats. The cartilage cellular matrixes of both knees were improved in SW(T) and SW(F) compared to that of OP. Serum bone morphogenetic protein 2 (BMP2) in rats undergoing SW(T) or SW(F) was significantly improved compared to that in Sham and OP. The expressions of BMP2, BMP4, and SMAD family member 4 (Smad4) in addition to the Wnt family member 3A (Wnt3a) and Cyclin D1 signaling key factors were significantly induced in the cartilage of both knees by shockwave (SW). SW(T) presented the best efficacy to induce serum BMP2 to prevent bone loss from both lower limbs. Here, we display the protective effects of SW therapy to induce BMP2, BMP4, Smad4, Wnt3a, and Cyclin D1 signaling factors for cartilage loss in both knees of OVX rats.

Synergistic effects of miR-708-5p and miR-708-3p accelerate the progression of osteoporosis.

BackgroundBone homeostasis is a tightly orchestrated process maintained by osteoblasts and osteoclasts, and a disruption of their steady-state equilibrium can lead to the occurrence of osteoporosis (OP).MethodsWe investigated the differential expression of micro (mi)RNAs in the bone tissues of a postmenopausal osteoporosis rat model induced by ovariectomy (OVX). Real-time PCR was used to verify the differentially expressed miRNAs in bone samples from OP patients and controls. The specific targets of two differentially expressed miRNAs in osteogenic or osteoclast differentiation were determined by bioinformatic prediction, and mRNA and protein detection.ResultsmiR-708-5p and miR-708-3p were highly expressed in the bone tissue of OVX rats and OP patients. miR-708-5p negatively regulated osteoblast differentiation in bone marrow mesenchymal stem cells by targeting SMAD specific E3 ubiquitin protein ligase 2, while miR-708-3p positively regulated osteoclast differentiation in bone marrow monocytes by targeting cerebellar degeneration associated protein 1 antisense RNA. miR-708-5p and miR-708-3p were shown to originate from the same precursor miRNA and to have a synergistic effect on the development of osteoporosis with different temporal and spatial patterns.ConclusionOur findings provide a referential theoretical basis and targets for the prevention and treatment of osteoporosis.

Lactobacillus-fermented milk products attenuate bone loss in an experimental rat model of ovariectomy-induced post-menopausal primary osteoporosis.

In this study, we investigated the anti-osteoporotic effect of two fermented milk products (FMPs) fermented by Lactobacillus plantarum A41 and Lactobacillus fermentum SRK414 on a rat model of ovariectomy-induced post-menopausal primary osteoporosis. The two Lactobacillus FMPs increased the bone volume and bone mineral density (BMD) in ovariectomized (OVX) rats, and normalized the bone biomarkers in the serum. Additionally, they altered the gene expression levels of bone-metabolism-related markers. Furthermore, the two Lactobacillus FMPs downregulated bone-apoptosis-related genes stimulated by ovariectomy. Interestingly, the Lactobacillus FMPs decreased the levels of inflammation markers in the serum, bone, ileum and colon of the rats. Gut bacterial populations were also affected upon FMP treatment due to increase in the abundance of the genus Lactobacillus and Faecalibacterium prausnitzii. Milk products fermented by L. plantarum A41 and L. fermentum SRK414 can exhibit anti-osteoporotic effects on post-menopausal osteoporosis via regulating the expression of bone-metabolism-related markers. The two Lactobacillus FMPs used in the study can be an ideal method that has its potential of treating post-menopausal osteoporosis instead of drug treatments.

A Novel Vitamin D Receptor Agonist, VS-105, Improves Bone Mineral Density without Affecting Serum Calcium in a Postmenopausal Osteoporosis Rat Model.

Background and objectives:VS-105, a novel vitamin D receptor agonist with significantly less hypercalcemic side effects than calcitriol, is a useful tool to investigate whether or not a vitamin D receptor agonist at non-hypercalcemic doses could improve bone mineral density (BMD).Methods:VS-105 and calcitriol were evaluated in an ovariectomized (OVX) osteoporosis rat model and in calvariae bone organ culture.Results:Treatment of OVX rats by VS-105 (0.1, 0.2 or 0.5 μg/kg, intraperitoneal, 3×/week, for 90 days) significantly improved BMD in the L3 lumbar vertebra in a dose-dependent manner (sham vs. OVX/vehicle: 324 ± 14 vs. 279 ± 10 mg/cm2; VS-105 at 0.1, 0.2 and 0.5 μg/kg: 306 ± 9, 329 ± 12, and 327 ± 10 mg/cm2, respectively) without affecting serum calcium (Ca). Calcitriol at 0.1 μg/kg significantly increased BMD but it also increased serum Ca. VS-105 and calcitriol at the test doses significantly suppressed serum parathyroid hormone and promoted tibia bone growth. With respect to biomarkers of bone remodeling, calcitriol and VS-105 both significantly elevated serum osteocalcin. In the calvariae bone organ culture, net Ca release was significantly less in VS-105-treated groups (vs. calcitriol).Conclusions:VS-105 is efficacious in improving BMD in a dose range that does not affect serum Ca in OVX rats; the improvement in BMD by VS-105 is attributable to increased osteoblastic activity and reduced osteoclastic bone resorption.

Morphometric Effects of Whole-Body Vibration on the Bone in a Rat Model of Postmenopausal Osteoporosis

ObjectiveThe purpose of this study was to analyze the morphometric effects of mechanical vibration with a duration of 4 or 8 weeks on the femur of oophorectomized Wistar rats. MethodsSixty-four female rats were submitted to oophorectomy or a sham operation, and each of those 2 groups were randomized into 4 groups: untreated and euthanized at week 12, untreated and euthanized at week 16, treated for 4 weeks and euthanized at week 12, and treated for 8 weeks and euthanized at week 16. The vibration treatment was performed for 10 min/d, with a frequency of 60 Hz, 3 d/wk. The rats were then euthanized and the right femur dissected. Subsequently, histomorphometric analysis was performed on the proximal epiphysis and diaphysis of the spongy and cortical bone, respectively. ResultsAs expected, the oophorectomy groups presented reduction of spongy and cortical bone tissue. Further, the vibration therapy of 4 and 8 weeks’ duration in the oophorectomized groups led to increased bone mass, observed as an increased percentage of spongy tissue, and increased thickness and percentage of cortical tissue. However, the variables of femoral neck diameter, mean area of the shaft, and number of osteocytes were not altered by oophorectomy and vibration. ConclusionThe mechanical vibration was effective in increasing the bone mass of the femur of oophorectomized Wistar rats, observed by increasing the percentage of spongy bone and increasing the percentage and thickness of cortical bone.

Estrogen Deficiency Influences Hematological Parameters Following Bone Fracture in OVX Rats

Abstract Objectives Estrogen deficiency in postmenopausal women contributes to the development of osteoporosis. Furthermore, estrogen deficiency is associated with significant changes in hematological parameters including inflammatory markers. Since inflammation contributes to the pathophysiology of osteoporosis, the relationship between bone fracture, estrogen deficiency, and hematological parameters warrant investigation. Using an ovariectomized (OVX) rat model of postmenopausal osteoporosis, the objective of this research was to investigate the extent to which bone fracture in conditions of low estrogen affects hematological parameters compared to bone fracture in estrogen sufficient conditions. Methods 12-month old Sprague Dawley rats were randomized into one of four groups (1. OVX + Fracture, 2. OVX + no fracture, 3. Sham + fracture, 4. Sham + no fracture). Rats randomized into the OVX + fracture and sham + fracture groups underwent fracture of the right fibula. After sacrificing the animals, blood was collected for analysis of hematological parameters. Results All data are presented as mean ± S.E. As expected, OVX induced significant changes in hematological parameters compared to Sham. OVX compared to sham increased WBC (5.78 ± 0.93 vs. 1.73 ± 0.93 P &amp;lt; 0.01) and EOS (2.75 ± 0.39 vs. 1.50 ± 0.39 P &amp;lt; 0.05) and decreased PLT (357 ± 61 vs. 627 ± 61 P &amp;lt; 0.01). No changes were observed in hematological parameters of sham + fracture compared to sham. However, OVX + fracture increased MPV (6.33 ± 0.07 vs. 6.03 ± 0.09 P &amp;lt; 0.5) and tended to increase WBC (4.80 ± 0.66 vs. 2.73 ± 0.86 P = 0.06) and EOS (1.73 ± 0.28 vs. 0.81 ± 0.36 P = 0.55). Conclusions These results are in accordance with previous reports indicating that OVX causes changes in hematological parameters. We also demonstrated that under conditions of bone fracture, OVX causes further changes in hematological parameters compared to sham. However, the implications in these changes for bone healing in conditions of low estrogen such as postmenopausal osteoporosis still need further investigation. Funding Sources USDA.