scholarly journals Different Molecular Mechanisms Underlie Ethanol-Induced Bone Loss in Cycling and Pregnant Rats

Endocrinology ◽  
2006 ◽  
Vol 147 (1) ◽  
pp. 166-178 ◽  
Author(s):  
Kartik Shankar ◽  
Mats Hidestrand ◽  
Rani Haley ◽  
Robert A. Skinner ◽  
William Hogue ◽  
...  

Chronic ethanol (EtOH) consumption can result in osteopenia. In the current study, we examined the modulation of EtOH-induced bone loss during pregnancy. Nonpregnant and pregnant dams were intragastrically infused either control or EtOH-containing diets throughout gestation (gestation d 5 through 20 or an equivalent period of 15 d) by total enteral nutrition. The effects of EtOH (8.5 to 14 g/kg/d) on tibial bone mineral density (BMD), mineral content (BMC), and bone mineral area were assessed at gestation d 20 via peripheral quantitative computerized tomography. EtOH caused a dose-dependent decrease in BMD and BMC without affecting bone mineral area. Trabecular BMD and BMC were significantly lower in EtOH-treated, nonpregnant dams, compared with pregnant cohorts at the same infused dose of EtOH and urinary ethanol concentrations. Static histomorphometric analysis of tibiae from pregnant rats after EtOH treatment showed decreased osteoblast and osteoid surface, indicating inhibited bone formation, whereas EtOH-treated cycling rats showed higher osteoclast and eroded surface, indicative of increased bone resorption. Circulating osteocalcin and 1,25-dihydroxyvitamin D3 were lower in both EtOH-fed nonpregnant and pregnant rats. Gene expression of osteoclast markers, 70 kDa v-ATPase, and tartrate-resistant acid phosphatase were increased selectively in nonpregnant EtOH-treated rats but not pregnant rats. Moreover, only nonpregnant EtOH-fed rats showed induction in bone marrow receptor activator of nuclear factor-κB ligand mRNA and decreased circulating 17β-estradiol levels. Our data suggest that EtOH-induced bone loss in pregnant rats is mainly due to inhibited bone formation, whereas in nonpregnant rats, the data are consistent with increased osteoclast activation and bone resorption concomitant with decreased estradiol levels.

2013 ◽  
Vol 110 (08) ◽  
pp. 257-263 ◽  
Author(s):  
Timoleon-Achilleas Vyzantiadis ◽  
Maria Charizopoulou ◽  
Fotini Adamidou ◽  
Spyridon Karras ◽  
Dimitrios Goulis ◽  
...  

SummaryHaemophilia A and B have been associated with increased prevalence of low bone mineral density (BMD). However, no study has so far evaluated the effects of anti-osteoporotic therapy on BMD in haemophilia. The primary endpoint of this prospective study was to estimate the effect of 12-month therapy of oral ibandronate 150 mg/ month on BMD in patients with haemophilia A and B. Secondary endpoint was its effect on turnover markers (BTM) of bone resorption [serum C-terminal telopeptide of type 1 collagen (sCTX), tartrate-resistant acid phosphatase band 5b] and bone formation (osteocalcin and bone-specific alkaline phosphatase. Ten adult patients with T-score < −2.5 SD or Z-score < −2 and/or increased risk of fracture according to FRAX model were included. All received 1,000 mg/day calcium carbonate with 800 IU/d cholecalciferol. Males with haemophilia A (n=7) or B (n=3) (mean age 43.5 ± 13.5 years) were studied. Ibandronate resulted in an increase in lumbar BMD (from 0.886 ± 0.169 to 0.927 ± 0.176 g/cm2, 4.7%, p=0.004). No change in BMD of total hip (from 0.717 ± 0.128 to 0.729 ± 0.153 g/cm2, p=0.963) or femoral neck (0.741 ± 0.135 to 0.761 ± 0.146 g/cm2, p=0.952) was noticed. Ibandronate led to a decrease in sCTX (from 0.520 ± 0.243 to 0.347 ± 0.230 ng/ml, −29.9%, p=0.042). No change was observed in other BTM. Ibandronate was generally well-tolerated. In conclusion, ibandronate significantly improved BMD in lumbar spine and reduced bone resorption in adults with haemophilia at increased risk of fracture. Its effect on hip BMD and bone formation markers was not significant.


2018 ◽  
Vol 238 (1) ◽  
pp. 13-23 ◽  
Author(s):  
Thomas Funck-Brentano ◽  
Karin H Nilsson ◽  
Robert Brommage ◽  
Petra Henning ◽  
Ulf H Lerner ◽  
...  

WNT signaling is involved in the tumorigenesis of various cancers and regulates bone homeostasis. Palmitoleoylation of WNTs by Porcupine is required for WNT activity. Porcupine inhibitors are under development for cancer therapy. As the possible side effects of Porcupine inhibitors on bone health are unknown, we determined their effects on bone mass and strength. Twelve-week-old C57BL/6N female mice were treated by the Porcupine inhibitors LGK974 (low dose = 3 mg/kg/day; high dose = 6 mg/kg/day) or Wnt-C59 (10 mg/kg/day) or vehicle for 3 weeks. Bone parameters were assessed by serum biomarkers, dual-energy X-ray absorptiometry, µCT and histomorphometry. Bone strength was measured by the 3-point bending test. The Porcupine inhibitors were well tolerated demonstrated by normal body weight. Both doses of LGK974 and Wnt-C59 reduced total body bone mineral density compared with vehicle treatment (P < 0.001). Cortical thickness of the femur shaft (P < 0.001) and trabecular bone volume fraction in the vertebral body (P < 0.001) were reduced by treatment with LGK974 or Wnt-C59. Porcupine inhibition reduced bone strength in the tibia (P < 0.05). The cortical bone loss was the result of impaired periosteal bone formation and increased endocortical bone resorption and the trabecular bone loss was caused by reduced trabecular bone formation and increased bone resorption. Porcupine inhibitors exert deleterious effects on bone mass and strength caused by a combination of reduced bone formation and increased bone resorption. We suggest that cancer targeted therapies using Porcupine inhibitors may increase the risk of fractures.


Author(s):  
Abin Joy ◽  
Chaitra N ◽  
Ashok M ◽  
Handral M

ABSTRACTObjectives: This study was designed to investigate the antiosteoporotic activity of isolated anthraquinones from Morinda citrifolia fruit extract inovariectomy (OVX) induced osteoporotic rats.Methods: All the rats were divided into 4 groups (n=6 each). Group I (sham control) received vehicle, p.o., Group II OVX control (vehicle, p.o.),Group III was OVX+standard raloxifene (5.4 mg/kg, p.o.), and Group IV was OVX+Physcion (100 mg/kg, p.o.) for 90 days.Results: The daily oral administration of isolated compound physcion (100 mg/kg) for 12 weeks to the rats prevented OVX-induced osteoporosis.This was examined by serum biomarkers such as alkaline phosphatase, calcium, and tartrate resistant acid phosphatase and showed significanteffects (p<0.0001). The femur bone strength assessed by three-point bending test showed improved bone strength in physcion treated rats, andthis was supported by enhanced bone mineral density (p<0.05). The ash parameters of femur bone studied from physcion treated rats exhibited asignificant (p<0.0001) value of ash weight followed by ash calcium content. Further, femur bone histological examination revealed the protectiveeffect of the compound physcion (100 mg/kg) against OVX-induced bone loss in rats, where it showed mineralization of trabecular spaces, improvedbone compactness thereby intact bone architecture.Conclusion: This study concludes that the isolated anthraquinone physcion had a preventive effect against OVX-induced bone loss in rats.Keywords: Morinda citrifolia, Physcion, Osteoporosis, Bone mineral density, Ash mineral content.


2010 ◽  
Vol 299 (3) ◽  
pp. E426-E436 ◽  
Author(s):  
Panan Suntornsaratoon ◽  
Kannikar Wongdee ◽  
Suchandra Goswami ◽  
Nateetip Krishnamra ◽  
Narattaphol Charoenphandhu

The lactogenic hormone prolactin (PRL) directly regulates osteoblast functions in vitro and modulates bone remodeling in nulliparous rats, but its osteoregulatory roles in pregnant and lactating rats with physiological hyperprolactinemia remained unclear. Herein, bone changes were investigated in rats treated with bromocriptine (Bromo), an inhibitor of pituitary PRL release, or Bromo+PRL at different reproductive phases, from mid-pregnancy to late lactation. PRL receptors were strongly expressed in osteoblasts lining bone trabeculae, indicating bone as a target of PRL actions. By using dual energy X-ray absorptiometry, we found a significant increase in bone mineral density in the femora and vertebrae of pregnant rats. Such pregnancy-induced bone gain was, however, PRL independent and may have resulted from the increased cortical thickness. Bone trabeculae were modestly changed during pregnancy as evaluated by bone histomorphometry. On the other hand, lactating rats, especially in late lactation, showed massive bone loss in bone trabeculae but not in cortical shells. Further study in Bromo- and Bromo+PRL-treated rats suggested that PRL contributed to decreases in trabecular bone volume and number and increases in trabecular separation and eroded surface, as well as a paradoxical increase in bone formation rate in late lactation. Uncoupling of trabecular bone formation and resorption was evident in lactating rats, with the latter being predominant. In conclusion, pregnancy mainly induced cortical bone gain, whereas lactation led to trabecular bone loss in both long bones and vertebrae. Although PRL was not responsible for the pregnancy-induced bone gain, it was an important regulator of bone modeling during lactation.


2013 ◽  
Vol 98 (2) ◽  
pp. 571-580 ◽  
Author(s):  
Kim Brixen ◽  
Roland Chapurlat ◽  
Angela M. Cheung ◽  
Tony M. Keaveny ◽  
Thomas Fuerst ◽  
...  

Abstract Context: Odanacatib, a cathepsin K inhibitor, increases spine and hip areal bone mineral density (BMD) in postmenopausal women with low BMD and cortical thickness in ovariectomized monkeys. Objective: The objective of the study was to examine the impact of odanacatib on the trabecular and cortical bone compartments and estimated strength at the hip and spine. Design: This was a randomized, double-blind, 2-year trial. Setting: The study was conducted at a private or institutional practice. Participants: Participants included 214 postmenopausal women with low areal BMD. Intervention: The intervention included odanacatib 50 mg or placebo weekly. Main Outcome Measures: Changes in areal BMD by dual-energy x-ray absorptiometry (primary end point, 1 year areal BMD change at lumbar spine), bone turnover markers, volumetric BMD by quantitative computed tomography (QCT), and bone strength estimated by finite element analysis were measured. Results: Year 1 lumbar spine areal BMD percent change from baseline was 3.5% greater with odanacatib than placebo (P &lt; .001). Bone-resorption marker C-telopeptide of type 1 collagen was significantly lower with odanacatib vs placebo at 6 months and 2 years (P &lt; .001). Bone-formation marker procollagen I N-terminal peptide initially decreased with odanacatib but by 2 years did not differ from placebo. After 6 months, odanacatib-treated women had greater increases in trabecular volumetric BMD and estimated compressive strength at the spine and integral and trabecular volumetric BMD and estimated strength at the hip (P &lt; .001). At the cortical envelope of the femoral neck, bone mineral content, thickness, volume, and cross-sectional area also increased from baseline with odanacatib vs placebo (P &lt; .001 at 24 months). Adverse experiences were similar between groups. Conclusions: Over 2 years, odanacatib decreased bone resorption, maintained bone formation, increased areal and volumetric BMD, and increased estimated bone strength at both the hip and spine.


2021 ◽  
Vol 23 (1) ◽  
pp. 55
Author(s):  
Zamzam Awida ◽  
Almog Bachar ◽  
Hussam Saed ◽  
Anton Gorodov ◽  
Nathalie Ben-Califa ◽  
...  

The two erythropoietin (EPO) receptor forms mediate different cellular responses to erythropoietin. While hematopoiesis is mediated via the homodimeric EPO receptor (EPOR), tissue protection is conferred via a heteromer composed of EPOR and CD131. In the skeletal system, EPO stimulates osteoclast precursors and induces bone loss. However, the underlying molecular mechanisms are still elusive. Here, we evaluated the role of the heteromeric complex in bone metabolism in vivo and in vitro by using Cibinetide (CIB), a non-erythropoietic EPO analogue that exclusively binds the heteromeric receptor. CIB is administered either alone or in combination with EPO. One month of CIB treatment significantly increased the cortical (~5.8%) and trabecular (~5.2%) bone mineral density in C57BL/6J WT female mice. Similarly, administration of CIB for five consecutive days to female mice that concurrently received EPO on days one and four, reduced the number of osteoclast progenitors, defined by flow cytometry as Lin−CD11b−Ly6Chi CD115+, by 42.8% compared to treatment with EPO alone. In addition, CIB alone or in combination with EPO inhibited osteoclastogenesis in vitro. Our findings introduce CIB either as a stand-alone treatment, or in combination with EPO, as an appealing candidate for the treatment of the bone loss that accompanies EPO treatment.


2019 ◽  
Vol 10 (9) ◽  
Author(s):  
Wenxiang Chen ◽  
Ziang Xie ◽  
Pan Tang ◽  
Yongli Wang ◽  
Zhiwei Jie ◽  
...  

Abstract Osteoporosis is caused by an imbalance between bone formation and bone resorption. Receptor activator of nuclear factor-κB ligand (RANKL) promotes the activity and differentiation of osteoclasts via activating the nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. IMD 0354 is a selective molecular inhibitor of inhibitor of NF-κB kinase subunit beta (IKKβ) and effective for treatment of acute and subacute inflammatory diseases through the suppression of NF-κB activation. However, the effect of IMD 0354 on bone homeostasis is unknown. In this study, we demonstrated that IMD 0354 significantly attenuated ovariectomy-induced bone loss and inhibited osteoclastogenesis in mice, whereas bone formation was not affected. Additionally, IMD 0354 dramatically inhibited osteoclast differentiation and function induced by RANKL and macrophage colony-stimulating factor in bone marrow monocytes as verified by tartrate-resistant acid phosphatase (TRAP) staining as well as bone resorption assay in vitro. Subsequently, we found that activation of NF-κB signaling and the ERK/c-Fos axis were blunted during osteoclast formation induced by RANKL. Transcription factors nuclear factor of activated T cells c1 (NFATc1) and c-Fos were suppressed with the decreased expression of osteoclast-related genes by IMD 0354. Our findings suggest that IMD 0354 could be a potential preventive and therapeutic drug for osteoporosis.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Tae-Ho Kim ◽  
Eui Kyun Park ◽  
Man-Il Huh ◽  
Hong Kyun Kim ◽  
Shin-Yoon Kim ◽  
...  

Inhibition of osteoclast differentiation and bone resorption is a therapeutic strategy for the management of postmenopausal bone loss. This study investigated the effects ofRhus javanica(R. javanica) extracts on bone marrow cultures to develop agents from natural sources that may prevent osteoclastogenesis. Extracts ofR. javanica(eGr) cocoons spun byRhus javanica(Bell.) Baker inhibited the osteoclast differentiation and bone resorption. The effects of aqueous extract (aeGr) or 100% ethanolic extract (eeGr) on ovariectomy- (OVX-) induced bone loss were investigated by various biochemical assays. Furthermore, microcomputed tomography (µCT) was performed to study bone remodeling. Oral administration of eGr (30 mg or 100 mg/kg/day for 6 weeks) augmented the inhibition of femoral bone mineral density (BMD), bone mineral content (BMC), and other factors involved in bone remodeling when compared to OVX controls. Additionally, eGr slightly decreased bone turnover markers that were increased by OVX. Therefore, it may be suggested that the protective effects of eGr could have originated from the suppression of OVX-induced increase in bone turnover. Collectively, the findings of this study indicate that eGr has potential to activate bone remodeling by inhibiting osteoclast differentiation and bone loss.


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