Iron accumulation regulates osteoblast apoptosis through lncRNA XIST/miR-758-3p/caspase 3 axis leading to osteoporosis.

Postmenopausal osteoporosis (PMOP) is mainly caused by multiple factors. Recent studies have suggested that iron accumulation (IA) was closely related to PMOP. However, the detailed molecular mechanisms have not been well demonstrated. We constructed the IA mouse model by intraperitoneal injections of ferric ammonium citrate (FAC) and cell model by culturing with the medium containing FAC. Osteoporosis was confirmed in mouse bone tissues using H&E staining, and the level of serum ferritin, alkaline phosphatase (ALP), procollagen-1 N-terminal peptide (P1NP), and osteocalcin in mice was examined by ELISA. The expressions of XIST and miR-758-3p were detected by qRT-PCR. Cell proliferation and apoptosis were measured by CCK-8, TUNEL, and flow cytometry. The expression levels of apoptotic-related proteins were evaluated by western blot. Dual luciferase reporter assay was used to examine the molecular interaction. The expressions of ALP, P1NP, and osteocalcin, and the H&E staining of bone tissues in mice were analyzed to confirm the biological function of XIST and miR-758-3p in vivo. XIST was up-regulated while miR-758-3p was down-regulated in IA mouse and cell models. XIST knockdown significantly reduced FAC-induced osteoblast apoptosis, which was mimicked by transfection with miR-758-3p mimics. XIST acted as a sponge of miR-758-3p, which targeted caspase 3. IA led to the high expression of XIST and promoted osteoblast apoptosis through miR-758-3p/caspase 3. Transfection with shXIST or miR-758-3p mimics alleviated IA-induced mouse osteoporosis. IA regulated osteoblast apoptosis through XIST/miR-758-3p/caspase 3 axis, which might provide alternative targets for the treatment of osteoporosis.

Cnidium lactone prevents bone loss in an ovariectomized rat model through the estrogen-α/BMP-2/Smad signaling pathway.

BACKGROUND: The present study aimed to investigate the effect of cnidium lactone on ovariectomy (OVX)-induced bone loss and determine whether it exerts its effects by mediating the estrogen receptor-α (ERα)/bone morphogenetic protein-2 (BMP-2)/Smad signaling pathways. METHODS: Fifty-five female rats were randomly assigned to the following treatment groups: the OVX group, the sham-operated (sham) group, and groups treated with cnidium lactone at different doses (10 mg/kg/day, 20 mg/kg/day, 30 mg/kg/day). Treatments were administered for 60 days. Search Tool for Interacting Chemicals (STITCH; http://stitch.embl.de) was used to identify the interaction between cnidium lactone and target proteins. Bone mineral density (BMD), mechanical strength, serum osteoblastic and osteoclastic markers, and hematoxylin and eosin (HE) staining of the distal femur were evaluated. Moreover, western blot analyses were also performed to evaluate the effect of cnidium lactone on the ERα/BMP-2/Smad signaling pathway. RESULTS: Cnidium lactone treatment was associated with an increase in the BMD of the distal femur compared to that of the OVX group. Moreover, cnidium lactone significantly increased biomechanical properties in a dose-dependent manner compared to those of the OVX group (p < 0.05). Treatment with cnidium lactone significantly enhanced the BMP-2/Smad signaling pathway by up-regulating the expression of ERα, BMP-2, p-Smad1 and p-Smad4. Cnidium lactone treatment improved the microstructure of trabecular bone in the distal femurs of OVX rats, as shown by HE staining. CONCLUSIONS: Cnidium lactone exerts potent antiosteoporotic activity in ovariectomized mice, and the underlying molecular mechanism may be related to the ERα/BMP-2/Smad signaling pathways.

Arthroscopic repair of partial articular supraspinatus tendon avulsion lesions by conversion to full-thickness tears through a small incision.

PURPOSE: To assess the clinical efficacy of converting partial articular supraspinatus tendon avulsion (PASTA) lesions to full-thickness tears through a small local incision of the bursal-side supraspinatus tendon followed by repair. METHODS: We retrospectively analyzed 41 patients with Ellman grade 3 PASTA lesions and an average age of (54.7 ± 11.4) years from March 2013 to July 2017. Patients without regular conservative treatment and concomitant with other shoulder pathologies or previous shoulder surgery were excluded from the study. The tears were confirmed via arthroscopy, and a polydioxanone suture was placed to indicate the position of each tear. A small incision of approximately 6 mm was made using a plasma scalpel on the bursal-side supraspinatus tendon around the positioned suture to convert the partial tear into a full-thickness tear. The torn rotator cuff was sutured through the full thickness using a suture passer after inserting a 4.5-mm double-loaded suture anchor. Data were analyzed using a paired Student's t-test with statistical significance defined as p <0.05. RESULTS: At the final follow-up of 2 years, the pain-free shoulder joint range of motion and visual analog scale score were significantly improved compared to those before surgery (p < 0.001). The postoperative American Shoulder and Elbow Surgeons shoulder score was (90.6 ± 6.2), which was significantly higher than the preoperative score of (47.9 ± 8.3) (p < 0.001). The University of California at Los Angeles shoulder rating scale score increased from (14.7 ± 4.1) prior to surgery to (32.6 ± 3.4) points after surgery (p < 0.001). No patient had joint stiffness. CONCLUSION: This modified tear completion repair, by conversion to full-thickness tears through a small incision, has less damage to the supraspinatus tendon on the side of the bursa compared to traditional tear completion repair in the treatment of PASTA lesions. This surgical method is a simple and effective treatment that can effectively alleviate pain and improve shoulder joint function.

Hepcidin inhibition on the effect of osteogenesis in zebrafish.

Iron overload, as a risk factor for osteoporosis, can result in the up-regulation of Hepcidin, and Hepcidin knockout mice display defects in their bone microarchitecture. However, the molecular and genetic mechanisms underlying Hepcidin deficiency-derived bone loss remain unclear. Here, we show that hepcidin knockdown in zebrafish using morpholinos leads to iron overload. Furthermore, a mineralization delay is observed in osteoblast cells in hepcidin morphants, and these defects could be partially restored with microinjection of hepcidin mRNA. Quantitative real-time PCR analyses revealed the osteoblast-specific genes alp, runx2a, runx2b, and sp7 in morphants are down-regulated. Furthermore, we confirmed qRT-PCR results by in situ hybridization and found down-regulated genes related to osteoblast function in hepcidin morphants. Most importantly, we revealed that hepcidin was capable of removing whole-body iron which facilitated larval recovery from the reductions in bone formation and osteogenesis induced by iron overload.

Therapeutic effect of deferoxamine on iron overload-induced inhibition of osteogenesis in a zebrafish model.

Osteoporosis results from an imbalance in bone remodeling, in which osteoclastic bone resorption exceeds osteoblastic bone formation. Iron has recently been recognized as an independent risk factor for osteoporosis. Reportedly, excess iron could promote osteoclast differentiation and bone resorption through the production of reactive oxygen species (ROS). We evaluated the effect of iron on osteoblast differentiation and bone formation in zebrafish and further investigated the potential benefits of deferoxamine (DFO), a powerful iron chelator, in iron-overloaded zebrafish. The zebrafish model of iron overload described in this study demonstrated an apparent inhibition of bone formation, accompanied by decreased expression of osteoblast-specific genes (runx2a, runx2b, osteocalcin, osteopontin, ALP, and collagen type I). The negative effect of iron on osteoblastic activity and bone formation could be attributed to increased ROS generation and oxidative stress. Most importantly, we revealed that DFO was capable of removing whole-body iron and attenuating oxidative stress in iron-overloaded larval zebrafish, which facilitated larval recovery from the reductions in bone formation and osteogenesis induced by iron overload.

Hepcidin1 knockout mice display defects in bone microarchitecture and changes of bone formation markers.

Iron accumulation is a risk factor of osteoporosis; mechanisms leading to iron-related bone loss are not fully determined. We sought to better understand the effect of chronic iron accumulation on bone over the life span in a mouse model. Hepcidin1 knockout (Hepc1(-/-)) male mice and their littermate control wild type (WT) mice at 7 months old were used in this study. Serum iron and ferritin as well as iron contents in liver and femur were significantly increased in Hepc1(-/-) mice compared to WT mice. We found that Hepc1(-/-) mice had a phenotype of low bone mass and alteration of the bone microarchitecture, most likely caused by a decreased osteoblastic activity. Cell culture studies indicated that chronic iron accumulation decreased bone formation, probably by affecting bone morphogenetic protein signaling.

LKB1 and CRMP1 cooperatively promote the repair of the sciatic nerve injury.

After peripheral nervous system injury, Schwann cells (SCs) can repair axons by providing a growth-promoting microenvironment. The aim of this study is to explore the effects and mechanisms of LKB1 and CRMP1 on the repair of sciatic nerve injury (SNI). The expressions of LKB1 and CRMP1 were changed in rats with SNI from 12 h to 4 weeks by hematoxylin-eosin staining, RT-PCR assay, immunohistochemical staining, and western blotting. Immunofluorescence results show that LKB1 and CRMP1 are co-localized in the regenerated axons of the sciatic nerve tissue of SNI rats. Co-immunoprecipitation indicates that LKB1 interacts with CRMP1. LKB1 interference suppresses the phosphorylation level of CRMP1. Overexpression of LKB1 and CRMP1 promotes the invasion and migration of SCs, and nerve cell protuberance extends. The structure of the myelin sheath in the sciatic nerve of the model group was found to be loose and disordered. Rats in the model group had higher pain thresholds and heat sensitivity response times than those in the control group. Nerve conduction velocity, the latency of action potential, and the peak value of compound muscle action potential in the SNI group were significantly lower than those in the control group, and the muscle atrophy was severe. Overexpression of LKB1 may significantly improve the above conditions. However, the function of LKB1 to improve SNI is abolished by the interference of CRMP1. In summary, the interaction between LKB1 and CRMP promotes the migration and differentiation of SCs and the extension of neurons, thereby improving the repair of nerve injury.

The paradox of bone mineral density and fracture risk in type 2 diabetes.

Fracture risk in type 2 diabetes (T2D) patients is paradoxically increased despite no decrease in areal bone mineraldensity (BMD). This phenomenon, known as the "diabetic bone paradox", has been attributed to various factorsincluding alterations in bone microarchitecture and composition, hyperinsulinemia and hyperglycemia, advancedglycation end products (AGEs), and comorbidities associated with T2D. Zhao et al. recently investigated therelationship between T2D and fracture risk using both genetic and phenotypic datasets. Their findings suggest thatgenetically predicted T2D is associated with higher BMD and lower fracture risk, indicating that the bone paradox isnot observed when confounding factors are controlled using Mendelian randomization (MR) analysis. However, inprospective phenotypic analysis, T2D remained associated with higher BMD and higher fracture risk, even afteradjusting for confounding factors. Stratified analysis revealed that the bone paradox may disappear when T2Drelatedrisk factors are eliminated. The study also highlighted the role of obesity in the relationship between T2Dand fracture risk, with BMI mediating a significant portion of the protective effect. Overall, managing T2D-relatedrisk factors may be crucial in preventing fracture risk in T2D patients.

Vertebral HU value and the pectoral muscle index based on chest CT can be used to opportunistically screen for osteoporosis.

BACKGROUND: Existing studies have shown that computed tomography (CT) attenuation and skeletal muscle tissue are strongly associated with osteoporosis; however, few studies have examined whether vertebral HU values and the pectoral muscle index (PMI) measured at the level of the 4th thoracic vertebra (T4) are strongly associated with bone mineral density (BMD). In this study, we demonstrate that vertebral HU values and the PMI based on chest CT can be used to opportunistically screen for osteoporosis and reduce fracture risk through prompt treatment. METHODS: We retrospectively evaluated 1000 patients who underwent chest CT and DXA scans from August 2020-2022. The T4 HU value and PMI were obtained using manual chest CT measurements. The participants were classified into normal, osteopenia, and osteoporosis groups based on the results of dual-energy X-ray (DXA) absorptiometry. We compared the clinical baseline data, T4 HU value, and PMI between the three groups of patients and analyzed the correlation between the T4 HU value, PMI, and BMD to further evaluate the diagnostic efficacy of the T4 HU value and PMI for patients with low BMD and osteoporosis. RESULTS: The study ultimately enrolled 469 participants. The T4 HU value and PMI had a high screening capacity for both low BMD and osteoporosis. The combined diagnostic model-incorporating sex, age, BMI, T4 HU value, and PMI-demonstrated the best diagnostic efficacy, with areas under the receiver operating characteristic curve (AUC) of 0.887 and 0.892 for identifying low BMD and osteoporosis, respectively. CONCLUSIONS: The measurement of T4 HU value and PMI on chest CT can be used as an opportunistic screening tool for osteoporosis with excellent diagnostic efficacy. This approach allows the early prevention of osteoporotic fractures via the timely screening of individuals at high risk of osteoporosis without requiring additional radiation.

[Comparison of differences between hip and lumbar bone mineral density in dual energy X-ray absorptiometric data].

OBJECTIVE: To explore the changes and regulations in T-scores of hip and lumbar vertebrae in different aged people through retrospective data analyses of dual energy X-ray absorptiometry (DXA) and improve their reference values. METHODS: With the aid of DXA, the bone densities of hip (femoral neck) and lumbar (L1-L4) bones were measured in 3662 males and females over 45 years old. There were 9 female and 9 males groups based upon the stratifications of gender and 5-year age intervals (> 85-year-olds combined as one group). After ruling out the "single-part test" data, the T-score averages were calculated and their differences analyzed by t-test. RESULTS: In females, T-scores of hip and lumbar bone mineral density were basically the same before 50 years old. Significant differences existed between 51 and 75 years old females. The lumbar T-scores were lower than their hip counterparts. In some age groups, T-scores of lumbar vertebrae showed decreased bone mass while those of hip remained normal. However, T-scores of lumbar vertebrae might be diagnosed by osteoporosis but decreased bone mass of hip was absent in the other age groups. After 75 years, no obvious differences existed between hip and lumbar bone T-scores; in all male groups, hip T-scores were lower than lumbar counterparts. There were small changes in T-scores of lumbar vertebrae with aging while the hip ones decreased gradually; each group had a single measurement rate of skeletal site. In females, the minimal and maximal values of single site measurement rate were 12.50% and 63.98% versus 16.68% and 44.50% in males. CONCLUSION: Differences of lumbar and hip T-scores exist in some age groups. Thus some normal T-scores of one skeletal site may be abnormal at another site. While evaluating one particular site, one should consider these differences to avoid an incorrect diagnosis.

[Relationship of iron overload to bone mass density and bone turnover in postmenopausal women with fragility fractures of the hip].

OBJECTIVE: To study relationships between serum ferritin and bone metabolism in patients with hip fragility fractures. METHODS: This cross-sectional study included 76 postmenopausal women with hip fracture from Feburary 2011 to June 2012. The mean age of the women was (73 ± 10) years (range, 55-93 years) and the mean duration of menstruation was (22 ± 10)years (range, 5-50 years). Serum concentrations of ferritin, transferrin, alkaline phosphatase (ALP), amino-terminal extension peptide of type I collagen (P1NP), C-terminal telopeptides of type I collagen (ß-CTX)and femoral and lumbar bone mineral density by dual-energy X-ray absorptiometry were measured. Bone metabolism was compared between normal and elevated ferritin groups with t-test, Pearson linear, partial correlation and multiple regression analysis examined associations between iron- and bone-related markers. RESULTS: Serum ferritin concentration raised to (230 ± 146)µg/L, transferrin concentration reduced to (1.89 ± 0.33)g/L. P1NP concentration raised to (61 ± 32) ng/L when the concentration of serum ALP and ß-CTX were in the normal range. T-scores for bone mineral density in the femoral neck (-2.0 ± 1.1) and lumbar (-2.1 ± 1.2) were below the normal ranges(-1.0-1.0). The subjects were divided into two groups according to serum ferritin concentration, normal group(serum ferritin concentration ≤ 150 µg/L, n = 25) and elevated group(serum ferritin concentration > 150 µg/L, n = 51). Patients of elevated group had lower bone mineral density in femoral neck and lumbar than normal group(t = 3.13,2.89, P < 0.01), and higher P1NP, ß-CTX concentration (t = -2.38, -3.59, P < 0.05) . In partial correlation analysis adjusted for confounders, serum ferritin concentration was correlated negatively with bone mineral density in both femoral neck and lumbar (r = -0.335,-0.295, P < 0.05), and positively with P1NP and ß-CTX (r = 0.467,0.414, P < 0.05), but not correlated with ALP (r = 0.188, P > 0.05). Transferrin concentration tended to be correlated positively with bone mineral density in both femoral neck and lumbar (r = 0.444, 0.262, P < 0.05) and negatively with ALP, P1NP and ß-CTX(r = -0.326,-0.285,-0.278, P < 0.05). CONCLUSIONS: Iron overload has a high prevalence in postmenopausal women with fragility fracture. Increased iron stores, which might lead to bone loss and lower bone mineral density by enhancing the activity of bone turnover, could be an independent factor to take effects on bone metabolism on postmenopausal women.

Role of Iron Accumulation in Osteoporosis and the Underlying Mechanisms.

Osteoporosis is prevalent in postmenopausal women. The underlying reason is mainly estrogen deficiency, but recent studies have indicated that osteoporosis is also associated with iron accumulation after menopause. It has been confirmed that some methods of decreasing iron accumulation can improve the abnormal bone metabolism associated with postmenopausal osteoporosis. However, the mechanism of iron accumulation-induced osteoporosis is still unclear. Iron accumulation may inhibit the canonical Wnt/ß-catenin pathway via oxidative stress, leading to osteoporosis by decreasing bone formation and increasing bone resorption via the osteoprotegerin (OPG)/receptor activator of nuclear factor kappa-B ligand (RANKL)/receptor activator of nuclear factor kappa-B (RANK) system. In addition to oxidative stress, iron accumulation also has been reported to inhibit either osteoblastogenesis or osteoblastic function as well as to stimulate either osteoclastogenesis or osteoclastic function directly. Furthermore, serum ferritin has been widely used for the prediction of bone status, and nontraumatic measurement of iron content by magnetic resonance imaging may be a promising early indicator of postmenopausal osteoporosis.

Effect of hepcidin on intracellular calcium in human osteoblasts.

Hepcidin is known to increase intracellular iron through binding to and degrading ferroportin, which is a transmembrane protein that transports iron from the intracellular to the outside. However, it is not clear whether hepcidin has a similar effect on intracellular calcium. Here, we investigated the influence of hepcidin on intracellular calcium in human osteoblasts, with or without high environmental iron concentrations. Our data showed that hepcidin (<100 nmol/L) could increase intracellular calcium, and this effect was more significant when cells were exposed to high environmental iron concentrations. To further explore its underlying mechanisms, we pretreated human osteoblasts with Nimodipine, a L-type calcium channel blocker, and Dantrolene, a ryanodine receptor antagonist to inhibit abnormal calcium release from the sarco-endoplasmic reticulum. These treatments had not resulted in any alteration of intracellular calcium in human osteoblasts. Thus, these findings indicate that the increase of intracellular calcium induced by hepcidin is probably due to calcium release from endoplasmic reticulum, which is triggered by calcium influx.

[The effect of ferric ion on the differentiation of osteoclast and bone resorption].

OBJECTIVE: To explore the effects of ferric ion on the differentiation from both RAW264.7 and bone marrow macrophages to osteoclast in vitro and bone resorption in vivo. METHODS: In the presence of 50 ng/ml receptor activator of nuclear factor kappa-B ligand (RANKL), RAW264.7 was treated with ferric ammonium citrate (FAC). The formation of osteoclast was observed by staining of tartrate-resistant acid phosphatase (TRAP) and the TRAP positive cell counted. The expression levels of TRAP, cathepsin-K, nuclear factor of activated T cells c1 (NFATc1) and (receptor activator of NF-κB) RANK were measured by reverse transcription-polymerase chain reaction (RT-PCR).The control and iron overload groups were established by the intraperitoneal injection of normal saline and FAC. In vivo imaging system was employed to determine the bone density of femoral midportion and the fourth lumbar vertebra. After that, the bone marrow cells of femurs were used for osteoclast culture. The serum levels of ferritin, TRAP-5b, RANKL, osteoprotegerin (OPG) and C-terminal cross-linking telopeptide (CTX) were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: Ferric ion could stimulate the formation of TRAP positive cells in a dose-dependent manner. The expression levels of TRAP, cathepsin-K and NFATc1 in the FAC treated group were significantly higher those of the control group (P < 0.05) while the expression of RANK showed no statistical difference among these groups (P = 0.967). The bone marrow density of femoral midportion and the fourth lumbar vertebra of the iron-overload group decreased significantly versus the control group. The concentrations of ferritin, TRAP-5b, RANKL and CTX of the iron overload group were markedly higher than those of the control group (P < 0.05). Moreover, the concentration of ferritin showed a positive correlation with TRAP-5b and CTX respectively in the iron-overload group (r = 0.65, r = 0.76, P < 0.05). But no significant differences existed in the concentration of OPG for two groups (P > 0.05). CONCLUSION: Ferric ion may enhance the differentiation of osteoclast in vitro as well as bone resorption in vivo.

A novel method of manual positioning based on anatomical mark (shoulder-to-shoulder) to prevent postoperative leg-length discrepancy for femoral neck fractures in hip arthroplasty.

Objective: To determine whether the two lower extremities are of equal length after hip arthroplasty for femoral neck fractures, we developed a novel method of manual positioning based on anatomical mark (shoulder-to-shoulder) in hip arthroplasty. Methods: Patients with femoral neck fractures requiring hip arthroplasty from July 2020 to March 2022 in the orthopedic department of Jinjiang Municipal Hospital, Fujian Province, China were recruited. Hip arthroplasty was performed using the proposed "shoulder-to-shoulder" method of manual positioning based on anatomical mark in 52 patients with femoral neck fractures who met the inclusion criteria. "Shoulder-to-shoulder" was achieved by alignment of the marked femoral "shoulder" and the "shoulder" of prosthesis stem. There were 16 male and 36 female patients, with 27 undergoing total hip arthroplasty (THA) and 25 undergoing hip hemiarthroplasty (HA). The fractures were categorized according to the Garden classification: type II, type III, and type IV in 5, 11, and 36 patients, respectively. The vertical distance from the apex of the medial margin of the femoral trochanter to the tear drop line on both sides which was regarded as the length of both limbs were compared via postoperative imaging, and the apex-shoulder distance on the ipsilateral side measured via postoperative imaging was compared with those measured intraoperatively. Results: All patients completed the surgery successfully. The measurement results for the lower extremities after THA were as follows: contralateral group, 43.87 ± 5.59 mm; ipsilateral group, 44.64 ± 5.43 mm. The measurement results for the lower extremities after HA were as follows: contralateral group, 45.18 ± 7.82 mm; ipsilateral group, 45.16 ± 6.43 mm. The measurement results for the lower extremities after all arthroplasties were as follows: contralateral group, 44.50 ± 6.72 mm; ipsilateral group, 44.89 ± 5.90 mm. The results for the apex-shoulder distance were as follows: postoperative imaging, 19.44 ± 3.54 mm; intraoperative apex-shoulder distance, 27.28 ± 2.84 mm. Statistical analysis results indicated no statistically significant difference in the postoperative bilateral lower extremity length after hip arthroplasty (P = 0.75), while a statistically significant difference was found between the intraoperative and postoperative imaging measurements of the apex-shoulder distance (P < 0.01). Conclusion: The novel method of manual positioning based on anatomical mark (shoulder-to-shoulder) for femoral neck fractures in hip arthroplasty is simple and accurate, making it effective for preventing postoperative bilateral leg length discrepancy.

Efficacy of Yigu® versus Aclasta® in Chinese postmenopausal women with osteoporosis: a multicenter prospective study.

Zoledronic acid (ZOL) is a therapy inhibiting bone resorption. In this study, generic ZOL (Yigu®) showed its clinical efficacy consistency with original ZOL (Aclasta®) in Chinese postmenopausal women with osteoporosis. This study provides a practical basis for the application of Yigu® in Chinese population. INTRODUCTION: Yigu® has been approved its bioequivalence to Aclasta®. However, the clinical efficacy and safety of Yigu® have not been evaluated yet. Here, we compared the effectiveness and safety between Yigu® and Aclasta® in Chinese postmenopausal women with osteoporosis and assessed the efficacy of intravenous infusion of ZOL. METHODS: This was a randomized open-label, active-controlled study in postmenopausal women with osteoporosis of 14 clinical centers in China. Postmenopausal women with osteoporosis were recruited and randomized to receive a single infusion of 5 mg Yigu® or Aclasta®. The primary endpoint was the percentage change in bone mineral density (BMD) at lumbar spine after 12 months of treatment and was assessed for equivalence. The secondary endpoint was the percentage change in BMD at proximal femur after 12 months. Additional secondary endpoints were percentage changes in BMD at the above sites after 6 months of treatment and changes in bone turnover biomarkers during ZOL treatment. Safety was also evaluated and compared between two groups. RESULTS: A total of 458 postmenopausal women with osteoporosis were enrolled (n = 227, Yigu®; n = 231, Aclasta®). The mean percentage change in the BMD had no statistical difference at the lumbar spine (5.32% vs 5.18%), total hip (2.72% vs 2.83%), and femoral neck (2.37% vs 2.81%) between Yigu® and Aclasta® groups after 12 months of treatment. The mean difference of BMD change at the lumbar spine after 12 months between two groups was 0.15% (95% CI: - 0.71 to 1.00, equivalence margin: - 1.5%, 1.5%), demonstrating the treatments were equivalent. Meanwhile, the decreases in the P1NP and ß-CTX showed no difference between two groups after 14 days and 6 and 12 months of treatment. As regards the whole sample, BMD significantly increased after 12 months of treatment. Also, serum C-terminal telopeptide of type 1 collagen (ß-CTX) and procollagen 1 N-terminal peptide (P1NP) significantly decreased at each visit period. The overall adverse events were comparable and quite well between two groups. CONCLUSION: Intravenous infusion of zoledronic acid achieved the potent anti-resorptive effects which led to significant increase in BMD of Chinese postmenopausal women with osteoporosis. Yigu® was equivalent to Aclasta® with respect to efficacy and safety.

Iron accumulation deteriorated bone loss in estrogen-deficient rats.

BACKGROUND: Postmenopausal osteoporosis is characterized by an imbalance of bone resorption exceeding bone formation, resulting in a net loss of bone mass. Whether a menopause-related excess of iron contributes to the development of postmenopausal osteoporosis has remained unresolved due to a lack of an appropriate animal model. This study aimed to explore the effects of iron accumulation in bone mass in estrogen-deficient rats. METHODS: In the present study, ovariectomy (OVX) was performed in female rats and the changes of iron metabolism and some related modulated genes were detected. Ferric ammonium citrate (FAC) was used as a donor of iron for OVX rats. Moreover, micro-CT was performed to assess the bone microarchitecture in sham group, OVX, and FAC groups. Histological detection of iron in liver was assessed by Perl's staining. The expressions of ß-CTX and osteocalcin were assessed by ELISA. RESULTS: It was found that serum iron decreased after OVX. It was found that the expressions of Hepcidin in liver and Fpn, DMT-1 in duodenum significantly decreased at transcriptional level in OVX group than sham group. However, no difference existed in the expression of DMT-1. Then, ferric ammonium citrate (FAC) was used as a donor of iron for OVX rats. The FAC group manifested significant iron accumulation by increased serum iron and hepatic iron content. In addition, FAC treatment accelerated bone loss and decreased BMD and biomechanics in OVX rats. Moreover, bone biomarker ß-CTX rather than osteocalcin increased significantly in FAC groups than OVX group. CONCLUSIONS: In conclusion, no iron accumulation occurred in OVX rats. Furthermore, iron accumulation could further deteriorate osteopenia through enhanced bone resorption.

miRNA-296-5p functions as a potential tumor suppressor in human osteosarcoma by targeting SND1.

BACKGROUND: The pathogenesis of osteosarcoma (OS) is still unclear, and it is still necessary to find new targets and drugs for anti-OS. This study aimed to investigate the role and mechanism of the anti-OS effects of miR-296-5p. METHODS: We measured the expression of miR-296-5p in human OS cell lines and tissues. The effect of miR-296-5p and its target gene staphylococcal nuclease and tudor domain containing 1 on proliferation, migration, and invasion of human OS lines was examined. The Student's t test was used for statistical analysis. RESULTS: We found that microRNA (miR)-296-5p was significantly downregulated in OS cell lines and tissues (control vs. OS, 1.802 ±â€Š0.313 vs. 0.618 ±â€Š0.235, t = 6.402, P < 0.01). Overexpression of miR-296-5p suppressed proliferation, migration, and invasion of OA cells. SND1 was identified as a target of miR-296-5p by bioinformatic analysis and dual-luciferase reporter assay. Overexpression of SND1 abrogated the effects induced by miR-296-5p upregulation (miRNA-296-5p vs. miRNA-296-5p + SND1, 0.294 ±â€Š0.159 vs. 2.300 ±â€Š0.277, t = 12.68, P = 0.003). CONCLUSION: Our study indicates that miR-296-5p may function as a tumor suppressor by targeting SND1 in OS.

Ginsenoside Rg1 promotes proliferation and neurotrophin expression of olfactory ensheathing cells.

Transplantation of olfactory ensheathing cells (OECs) is currently considered to be one of the most promising repair strategies for human spinal cord injury. However, the factors that regulate OECs are still poorly understood. Ginsenoside Rg1 (Rg1), the phytosterol from Panax ginseng, is a potent neuroprotective agent that promotes axonal regeneration. The aim of this study is to determine whether Rg1 would influence the biological activity of OECs. Primary cultured OECs from the olfactory bulb of neonatal rats were treated with Rg1 of various concentrations and durations. Using MTT and bromodeoxyuridine assays, we found that Rg1 significantly promoted cell proliferation, with an optimal concentration of 40 mug/ml of Rg1 at 72 h. In addition, RT-PCR and ELISA assays showed that Rg1 could upregulate the mRNA expression and secretion of glial cell-derived neurotrophic factor, brain-derived neurotrophic factor, and nerve growth factor. These results suggest that Rg1 may have a great potential in OEC therapy.

[Study on changes of coagulation state, microthrombus and vascular density in the model of iron accumulation osteoporosis].

OBJECTIVE: To understand changes of coagulation state, microthrombus, microvascular bed and bone density in the osteoporosis model of iron accumulation, and explore the influence of iron accumulation in aspects of osteoporosis on coagulation function and blood vessels. METHODS: Tewnty-four male SPF SD rats aged 6 months were selected, which with the average body weight (250±20) g, which were divided into control group and iron accumulation group according to random number table, 12 rats in each group. Iron accumulation group was intervened by intraperitoneal injection of ferric ammonium citrate 90 mg / kg, and control group was intraperitoneally injected with equal volume of normal saline, twice a week for 9 weeks. After intervention, serum ferritin, coagulation function, microthrombus, vascular density, and three-dimensional morphological reconstruction and spatial structure parameters of the distal femur trabeculae were measured and statistically analyzed. RESULTS: Serum ferritin of iron accumulation group (136.36±35.41) µg / L was higher than control group (68.44±16.86) µg / L(P<0.05). Bone mineral density (BMD) of iron accumulation group (0.167±0.024) g / cm3 was lower than control group(0.400±0.030)g / cm3. Fibrinogen of iron accumulation group (2.03±0.13) g / L was increased than that of control group (1.78±0.46) g / L, D-dimer contents of iron accumulation group (534.95±31.81) ng /ml was increased than that of control group (329.02±84.99) ng /ml, while thrombin time (39.64±2.18) s and prothrombin time(8.70±0.39) s of iron accumulation group were shorter than that of control group (44.92±2.98) s, (9.44±0.49) s (P<0.05). After ink staining, microvessel density in iron accumulation group (17.46±2.07)% was significantly reducedcompared with that of control group(23.81±2.98)%(P<0.05). HE and MSB staining which showed microthrombus in bone marrow of iron accumulation rats, as well as microthrombus in myocardium. CONCLUSION: In the osteoporosis model with the influence of iron accumulation, iron accumulation had a significant influence on the coagulation function, and the blood was relatively hypercoagulable. The bone vascular bed uas reduced, and there were microthrombus in the bone marrow. Hypercoagulable state of blood and formation of microthrombi may be important factors influencing the occurrence of iron accumulation osteoporosis.