Management of age-related osteoporosis and prevention of associated fractures

Pamidronate-Encapsulated Electrospun Polycaprolactone-Based Composite Scaffolds for Osteoporotic Bone Defect Repair

Bone fractures associated with osteoporosis are a major concern all over the world especially among the elderly population and postmenopausal women. Bisphosphonates (BPs) are widely used clinically for both treatment and prevention of osteoporosis despite their poor oral bioavailability and undesired side effects. Local delivery of BPs from polymeric scaffolds can improve the efficacy and overcome the undesirable side effects associated with oral bisphosphonate therapy. The aim of the present study is to explore the effectiveness of pamidronate (PDS) encapsulated electrospun polycaprolactone/polycaprolactone-polyethyleneglycol-polycaprolactone/nanohydroxyapatite (PCH) scaffolds in healing critical-size calvarial defects in an osteoporotic rat animal model. Prior to implantation studies, the effect of PDS on the fiber architecture, mechanical properties, and in vitro degradation behavior was evaluated. The in vitro release of PDS from PCH scaffolds in phosphate buffer saline (PBS) at 37 °C was monitored for a period of 21 days. An osteoporotic animal model was successfully developed in Wistar rats by bilateral ovariectomy. Results of micro CT (computed tomography) and blood serum analysis confirmed the osteoporotic model induction in rats. Critical-size calvarial defects of 8 mm size were created in osteoporotic rats, and the in vivo osteogenic efficacy of PCH-PDS scaffolds was evaluated by micro CT, histology, and histomorphometry. Micro CT analysis showed improved osseous tissue integration with the use of PDS-loaded PCH scaffolds after 12 week post implantation. Histology, density measurement using micro CT, and histomorphometry further substantiate that PCH-PDS scaffolds have the potential to be used for the repair of osteoporotic bone defects. Our findings revealed that incorporation of PDS onto PCH scaffolds provides a promising biomaterial that could be used for regenerating osteoporosis-related fractures.

May zoledronic acid have negative effects on cognition and muscle performance?

BACKGROUND

We aimed to investigate the effects of zoledronic acid treatment on daily living activities, cognitive functions, depression, muscle strength, and performance.

METHODS

The study was conducted retrospectively. Bone mineral densitometry (BMD) values, Katz activities of daily living (ADL), Lawton-Brody instrumental activities of daily living (IADL), mini mental state examination (MMSE), geriatric depression scale (GDS), mini nutritional assessment (MNA), grip strength, and gait speed scores before and 6 months after zoledronic acid administration were compared.

RESULTS

A total of 115 patients were included in the study. There was a significant increase in lumbar total (p < .001), femoral neck (p = .002), and femur total (p = .001) BMD values after zoledronic acid treatment. Significant decrease was found in MMSE (p = .016) and gait speed scores (p = .008) after zoledronic acid treatment, but no significant difference was found in terms of Katz ADL, Lawton-Brody IADL, MNA, GDS, and grip strength (p > .05).

CONCLUSION

Our study indicated that zoledronic acid did not affect daily living activities, depression, and muscle strength. Although we have concluded that cognitive and muscle performance may be adversely affected by zoledronic acid treatment.

The effect of low-level estrogen in mandibular bone: An in vivo study

BACKGROUND

Low levels of estrogen can cause osteoporosis and usually occur during a woman's menopausal phase. Osteoporosis can lead to bone resorption, the absence of osseointegration, and implant failure. The aim of this study is to determine the expression of transforming growth factor-beta 1 (TGF-β1), runt-related transcription factor (RUNX2), and osteoblasts in mandibular rats with low levels of estrogen.

MATERIALS AND METHODS

This study is an in vivo experimental research. Female Wistar rats (n = 18) were divided into two groups: (1) Postsham surgery and (2) ovariectomy group. After 12 weeks, the rats were sacrificed to identify the level of estrogen, while histological analysis was conducted to determine the level of osteoblast and the expression of TGF-β1 and RUNX2. The data were analyzed using t-test (P < 0.05).

RESULTS

There were significant lower levels of estrogen and osteoblast among the ovariectomy group compared to the postsham group (P < 0.05). RUNX2 levels were found to be significantly higher in the ovariectomy group than that in the postsham group (P < 0.05). However, there were no significant differences between TGF-β1 levels within the ovariectomy and postsham groups (P > 0.05).

CONCLUSION

Ovariectomy can lead to decreased osteoblastogenesis in mandibular bone by the reduced level of osteoblast and the increased expression of TGF-β1 and RUNX2.

Osteoblastic differentiation potential of human amniotic fluid-derived mesenchymal stem cells in different culture conditions

Osteoporosis is a bone degenerative disease characterized by a decrease in bone strength and an alteration in the osseous micro-architecture causing an increase in the risk of fractures. These diseases usually happen in post-menopausal women and elderly men. The most common treatment involves anti-resorptive agent drugs. However, the inhibition of bone resorption alone is not adequate for recovery in patients at the severe stage of osteoporosis who already have a fracture. Therefore, the combination of utilizing osteoblast micro mimetic scaffold in cultivation with the stimulation of osteoblastic differentiations to regain bone formation is a treatment strategy of considerable interest. The aims of this current study are to investigate the osteoblastic differentiation potential of mesenchymal stem cells derived from human amniotic fluid and to compare the monolayer culture and scaffold culture conditions. The results showed the morphology of cells in human amniotic fluid as f-type, which is a typical cell shape of mesenchymal stem cells. In addition, the proliferation rate of cells in human amniotic fluid reached the highest peak after 14 days of culturing. After which time, the growth rate slowly decreased. Moreover, the positive expression of specific mesenchymal cell surface markers including CD44, CD73, CD90, and also HLA-ABC (MHC class I) were recorded. On the other hand, the negative expressions of the endothelial stem cells markers (CD31), the hematopoietic stem cells markers (CD34, 45), the amniotic stem cells markers (CD117), and also the HLA-DR (MHC class II) were also recorded. The expressions of osteoblastogenic related genes including OCN, COL1A1, and ALP were higher in the osteogenic-induced group when compared to the control group. Interestingly, the osteoblastogenic related gene expressions that occurred under scaffold culture conditions were superior to the monolayer culture conditions. Additionally, higher ALP activity and greater calcium deposition were recorded in the extracellular matrix in the osteogenic-induced group than in the culture in the scaffold group. In summary, the mesenchymal stem cells derived from human amniotic fluid can be induced to be differentiated into osteoblastic-like cells and can promote osteoblastic differentiation using the applied scaffold.

A network meta-analysis on the short-term efficacy and adverse events of different anti-osteoporosis drugs for the treatment of postmenopausal osteoporosis

A network meta-analysis was conducted to compare the short-term efficacy and adverse events of different drugs for the treatment of postmenopausal osteoporosis (PMO), providing a more effective treatment for PMO. We initially searched through various databases like PubMed, Cochrane Library, and EMBASE from inception till October 2016. All randomized controlled trials (RCTs) of drugs for the treatment of PMO were included for direct and indirect comparison. A combination of direct and indirect evidence of different inhibitors of anti-diabetic drugs for treatment of PMO were considered for calculating the weighted mean difference (WMD) value or odd ratio (OR) value and to draw surface under the cumulative ranking (SUCRA) curves. Twenty-seven RCTs were ultimately incorporated into this network meta-analysis comprising of 48 200 patients suffering from PMO. The network meta-analysis revealed that compared with placebo, alendronate had better efficacy on improving bone mineral density (BMD) at lumbar spine, femoral neck, and total hip. Risedronate and raloxifene had relatively lower incidence of new vertebral fractures. The SUCRA analysis showed that alendronate had better efficacy on improving BMD, risedronate could significantly decrease the incidence of fresh fracture and bazedoxifene was relatively safe. The available evidence suggested that alendronate and risedronate might be the superior choices for the treatment of PMO, while bazedoxifene was a comparatively safer option for patients.

Promoting Effect of Pinostrobin on the Proliferation, Differentiation, and Mineralization of Murine Pre-osteoblastic MC3T3-E1 Cells

Pinostrobin (PI), a natural flavonoid found in a variety of plants, is well known for its rich pharmacological activities. However, its osteogenic function remains unclear. The aim of this study is to evaluate the effect of PI on the proliferation, differentiation, and mineralization of murine pre-osteoblastic MC3T3-E1 cells in vitro using MTT, alkaline phosphatase (ALP) activity, the synthesis of collagen I (Col I) assay, and Von-Kossa staining, respectively. The expression of osteocalcin (OCN) mRNA in cells was detected by real-time PCR. The effect of PI on the differentiation of dexamethasone (DEX)-suppressed cells was also investigated. The results showed that PI greatly promoted the proliferation of MC3T3-E1 cells at 5–80 μg/mL (p < 0.05 or p < 0.01), and caused a significant elevation of ALP activity, Col I content, and mineralization of osteoblasts at 10–40 μg/mL (p < 0.05 or p < 0.01), and the expression levels of OCN gene were greatly upregulated after PI treatment (p < 0.01). Furthermore, PI could rescue the inhibition effect of cell differentiation induced by DEX. Taken together, these results indicated that PI could directly promote proliferation, differentiation, and mineralization of MC3T3-E1 cells and has potential for use as a natural treatment for osteoporosis.

Role of therapeutic fasting in women's health: An overview

Fasting is a therapeutic tool practiced since millennia by different cultures and medical systems heterogeneously. PubMed and Google Scholar search engines were searched using the keywords "fasting," "intermittent fasting," "calorie restriction," "women's health," "women's disorders," "fasting and aging," and "fasting and health." All the animal and human studies which address women's health and disorders were included in the review. Fasting has shown to improve the reproductive and mental health. It also prevents as well as ameliorates cancers and musculoskeletal disorders which are common in middle-aged and elderly women. The present studies available have limitations such as majority of the studies are preclinical studies and human studies are with lesser sample size. Future studies should address this gap by designing medically supervised fasting techniques to extract better evidence. Nevertheless, fasting can be prescribed as a safe medical intervention as well as a lifestyle regimen which can improve women's health in many folds.

Effect of SI-591, a new class of cathepsin K inhibitor with peptidomimetic structure, on bone metabolism in vitro and in vivo

SI-591[N-[1-[[[(1S)-3-[[(3S)-hexahydro-2-oxo-1H-azepin-3-yl]amino]-1-(1-methylethyl)-2,3-dioxopropyl]amino]carbonyl]cyclohexyl]-2-furancarboxamide] is an orally bioavailable compound that was synthesized as one of several unique peptidomimetic compounds without a basic group. This compound was found to have the ability to inhibit cathepsin K, a lysosomal cysteine protease. Cathepsin K is known to be expressed in osteoclasts and involved in bone loss processes. In this study, SI-591 was shown to inhibit the activity of various purified cathepsin molecules at nanomolar concentrations but had high selectivity for cathepsin K over other subtypes including B and L. SI-591 also decreased the level of CTX-I, a bone resorption marker, which was released from osteoclasts in vitro in a dose-dependent manner. The mobilization of calcium from the bones to the blood stream is known to increase in rats fed with a low calcium diet; SI-591 inhibited this increase in serum calcium level at an oral dose of 3mg/kg. Furthermore, SI-591 significantly decreased the level of CTX-I and DPD, bone resorption markers, at oral doses of 10mg/kg or less in ovariectomized rats, while it did not affect the level of BGP, a bone formation marker. In addition, SI-591 prevented bone mineral density loss in the lumber vertebrae and femurs in ovariectomized rats. These results suggest that SI-591 inhibits bone resorption without affecting osteoblast maturation. Therefore, SI-591, a novel cathepsin K inhibitor, could be a promising agent for the treatment of postmenopausal osteoporosis.

Osteogenic potential of punica granatum through matrix mineralization, cell cycle progression and runx2 gene expression in primary rat osteoblasts

Background

Osteoporosis is one of the prevalent diseases in ageing populations. Due to side effects of many chemotherapeutic agents, there is always a need to search for herbal products to treat the disorder. Punica granatum (PG) represent a potent fruit-bearing medicinal herb which exerted valuable anti-osteoporotic activities. The present study was carried out to validate the in vitro osteogenic effects of the PG seed extract in primary calvarial osteoblast cultures harvested from neonatal rats.

Methods

The ethanolic extract of PG was subjected to evaluate cell proliferation, regeneration, mineralization and formation of collagen matrix using MTT, alkaline phosphatase, Alizarin Red-S staining and Sirius Red dye, respectively. Cell cycle progression and osteogenic gene Runx2 expression were carried out by flow cytometry and real time PCR, respectively.

Results

Exposure of different concentrations (10–100 μg/ml) of the extract on osteoblastic cells showed characteristic morphological changes and increment in cell number. A significant growth in cell proliferation, ALP activity, collagen contents and matrix mineralization of osteoblasts in a dose dependent manner (p < 0.05), suggested that PG has a stimulatory effect on osteoblastic bone formation or potential activity against osteoporosis. In addition, PG extract also enhanced DNA content in S phase of cell cycle and Runx2 gene expression level in osteoblasts.

Conclusion

The data clearly indicated that PG promoting bone cell proliferation and differentiation in primary osteoblasts might be due to elevating the osteogenic gene Runx2 expression. The present study provides an evidence for PG could be a promising herbal medicinal candidate that able to develop drugs for osteoporosis.

Involvement of the skeletal renin-angiotensin system in age-related osteoporosis of ageing mice

The local tissue-specific renin-angiotensin system (RAS) was identified. The aim of this study was to investigate the role of local bone RAS in the osteoporosis of aging mice. Twelve-month-old and two-month-old male mice were respectively assigned to the ageing and young groups. The tibias and femurs were collected for an analysis of histomorphology, bone mass, and gene and protein expression. H&E staining and micro-CT measurement showed a loss of the trabecular bone network and decrease of bone mineral density in the proximal tibial metaphysis of the aged mice. The PCR results indicated the significant up-regulation of renin and angiotensinogen (AGT) mRNA expression in both the tibia and femur of the ageing mice. Western blotting data showed that the tibial angiotensin II protein expression was significantly increased in the ageing group. The enhancement of renin and AGT expression in the bone tissue resulted in the increased production of angiotensin II which plays an important role in the pathology of age-related osteoporosis.

Increased fracture rate in women with breast cancer: a review of the hidden risk

Background

Women with breast cancer, particularly individuals diagnosed at a relatively early age, have an increased incidence of fractures. Fractures can have serious clinical consequences including the need for major surgery, increased morbidity and mortality, increased cost of disease management, and reduced quality of life for patients. The primary cause of the increased fracture risk appears to be an accelerated decrease in bone mineral density (BMD) resulting from the loss of estrogenic signaling that occurs with most treatments for breast cancer, including aromatase inhibitors. However, factors other than BMD levels alone may influence treatment decisions to reduce fracture risk in this setting. Our purpose is to review current evidence for BMD loss and fracture risk during treatment for breast cancer and discuss pharmacologic means to reduce this risk.

Results

Fracture risk during treatment for breast cancer may be influenced by the rate of BMD loss and the consequent rapid alterations in bone microarchitecture, in addition to the established fracture risk factors in postmenopausal osteoporosis. The rapid decrease in BMD during adjuvant chemoendocrine therapy for breast cancer may necessitate more aggressive pharmacotherapy than is indicated for healthy postmenopausal women who develop osteoporosis. Over the last few years, clinical trials have established the effectiveness of bisphosphonates and other antiresorptive agents to preserve BMD during adjuvant therapy for early breast cancer. In addition, some bisphosphonates (eg, zoledronic acid) may also delay disease recurrence in women with hormone-responsive tumors, thereby providing an adjuvant benefit in addition to preserving BMD and potentially preventing fractures.

Conclusions

It is likely that a combined fracture risk assessment (eg, as in the WHO FRAX algorithm) will more accurately identify both women with postmenopausal osteoporosis and women with breast cancer who require bone-protective therapy.

Osteoporosis and venous thromboembolism: a retrospective cohort study in the UK General Practice Research Database

In a retrospective cohort study using the General Practice Research Database (GPRD), there was a greater association of venous thromboembolism (VTE) in osteoporotic than in non-osteoporotic female patients. No greater association was shown in treated patients with strontium ranelate or alendronate compared to untreated osteoporotic female patients.

INTRODUCTION

We explored the risk of VTE in usual practice in osteoporotic and non-osteoporotic women with and without anti-osteoporotic treatment.

METHODS

A retrospective study was conducted using the GPRD in the UK. The cohorts consisted of untreated osteoporotic women (N = 11,546), osteoporotic women treated with alendronate (N = 20,084), or strontium ranelate (N = 2,408), and a sample of non-osteoporotic women (N = 115,009). Cohorts were compared using a Cox proportional hazards regression model.

RESULTS

There was a significantly increased relative risk for VTE in untreated osteoporotic women versus non-osteoporotic women (annual incidence 5.6 and 3.2 per 1,000 patient-years, respectively; relative risk 1.75 [95% confidence interval (CI), 1.09-1.84]). Results were confirmed using adjusted models. The annual incidences of VTE in osteoporotic patients treated with strontium ranelate and alendronate were 7.0 and 7.2 per 1,000 patient-years, respectively, with no significant difference between untreated and treated patients whatever the treatment. Adjusted hazard ratios for treated versus untreated osteoporotic women were 1.09 (95% CI, 0.60-2.01) for strontium ranelate and 0.92 (95% CI, 0.63-1.33) for alendronate.

CONCLUSION

This study shows a greater association of VTE in osteoporotic compared to non-osteoporotic patients, but does not show any greater association in treated patients with strontium ranelate or alendronate compared to untreated osteoporotic patients.