Blocking antibody to the β-subunit of FSH prevents bone loss by inhibiting bone resorption and stimulating bone synthesis

Low estrogen levels undoubtedly underlie menopausal bone thinning. However, rapid and profuse bone loss begins 3 y before the last menstrual period, when serum estrogen is relatively normal. We have shown that the pituitary hormone FSH, the levels of which are high during late perimenopause, directly stimulates bone resorption by osteoclasts. Here, we generated and characterized a polyclonal antibody to a 13-amino-acid-long peptide sequence within the receptor-binding domain of the FSH β-subunit. We show that the FSH antibody binds FSH specifically and blocks its action on osteoclast formation in vitro. When injected into ovariectomized mice, the FSH antibody attenuates bone loss significantly not only by inhibiting bone resorption, but also by stimulating bone formation, a yet uncharacterized action of FSH that we report herein. Mesenchymal cells isolated from mice treated with the FSH antibody show greater osteoblast precursor colony counts, similarly to mesenchymal cells isolated from FSH receptor (FSHR)(-/-) mice. This suggests that FSH negatively regulates osteoblast number. We confirm that this action is mediated by signaling-efficient FSHRs present on mesenchymal stem cells. Overall, the data prompt the future development of an FSH-blocking agent as a means of uncoupling bone formation and bone resorption to a therapeutic advantage in humans.     

Long-term influence of inhaled corticosteroids on bone metabolism and density. Are biological markers predictors of bone loss?

Long-term effects of high doses of inhaled corticosteroids (ICS) on bone density and metabolism are still uncertain. Fifty-one patients (37 male, 14 female) using beclomethasone or budesonide at a daily dose > 800 microgram/d (high-dose group [Group HD] mean: 983 microgram/d [prescribed dose x estimated compliance]) or no or < 500 microgram/d (control group [Group C] mean: 309 microgram/d) for more than 5 yr were enrolled in this study. Each had, 3 yr ago and at this last evaluation, a clinical evaluation and measurements of expiratory flows and of bone density and bone metabolism markers. Lumbar spine bone density (last visit) was similar in the two groups with respective values of 0.94 +/- 0.03 (HD) and 0.96 +/- 0.03 g/cm2 (C) (p > 0.05). T and Z scores were -1.21 +/- 0.19 and -0.70 +/- 0.18 (HD), -0.95 +/- 0.25 and -0.47 +/- 0.21 (C) respectively (p > 0.05). A correlation was found between the decrease in bone density and the mean daily dose of corticosteroid in Group HD although these changes were quite small, mean bone density being unchanged over the 3-yr period. Serum and urinary parameters were similar in the two groups. Furthermore, neither initial bone density nor any of the biological parameters could predict changes in bone density over a period of 3 yr. In conclusion, bone density was similar in both study groups and not significantly different over a 3-yr period. Neither initial bone density nor biological markers of bone metabolism helped to predict changes in bone mass.     

Active Paget’s disease of bone with normal biomarkers of bone metabolism: a case report and review of the literature

Paget’s disease of bone is a focal skeletal disorder characterized by the formation of structurally abnormal bone, skeletal deformities, and other complications leading to bone pain and significant disability. It can involve one or more areas in a single bone (monostotic) or multiple bones (polyostotic). Most of the time the disease is asymptomatic and the diagnosis is made incidentally by increased levels of bone metabolism markers, especially alkaline phosphatase and is confirmed by specific findings in radiographs and radionuclide bone scan. In this report, we describe the case of a 65-year-old female with clinical and radiological findings of active Paget’s disease of bone, but with absence of abnormal biochemical markers. The patient was given a dose of 5 mg zoledronic acid intravenously with significant clinical improvement within the next 6 months. The present case not only shows that Paget’s disease of bone can occur in the setting of normal markers of bone metabolism but also that, in such cases, the response to treatment can be monitored by improvement in the clinical picture or by correct evaluation of the imaging findings.     

Effects of 1-year anti-TNF-α therapies on bone mineral density and bone biomarkers in rheumatoid arthritis and ankylosing spondylitis

Clinical Rheumatology - Rheumatoid arthritis (RA) and ankylosing spondylitis (AS) have been associated with generalized and localized bone loss. We conducted a comprehensive study using imaging...     

Paget’s disease of bone: Diagnosis and treatment update

Paget's disease is a metabolic bone disease characterized by excessive bone resorption and formation due to activated osteoclasts. Although Paget's disease is a high bone turnover state, the excess bone that is formed lacks the structural stability of normal bone. Complications from Paget's disease include deformity, fracture, and pain. Although still unclear, both prevalence and severity of Paget's disease seem to be declining. Recent progress has focused on the environmental as well as genetic etiologies for this disease. Many studies indicate a role for viral infectious agents, whereas others point to a recently identified candidate gene on chromosome 18q. Therapy with bisphosphonate drugs is the treatment of choice. With newer and more powerful agents from this family now available, the majority of patients affected by Paget's disease can achieve sustained remission and avoid complications.     

Why do dialysis patients develop a heart of stone and bone of china?

Vascular calcification is a common complication of end-stage renal disease (ESRD). The mechanisms responsible are complex and have so far been considered to be mainly the result of a passive mechanism due to elevated PO(4) levels and high Ca x PO(4) ion product resulting in saturated plasma. However, recent results suggest that also other features, commonly observed in the uremic milieu, such as chronic inflammation, hyperleptinemia and a dysregulation of various mineral-regulating proteins might also contribute to an enhanced calcification process. Moreover, as an inverse relationship between vascular calcification and bone density has been documented in ESRD, it could be speculated that pathologically low bone remodelling (adynamic bone disease) associated with active vitamin D treatment and low parathyroid hormone (PTH) levels may predispose to ectopic calcification of vessels, valves and heart. As patients with vascular calcification have a higher intake of calcium-containing PO(4) binders, novel, non-calcium containing PO(4) binders may diminish the risk of progressive vascular calcification in this patient group. Further studies are needed to elucidate the respective role of chronic inflammation, hyperleptinemia and PTH-lowering therapies in this fatal complication of ESRD.     

What are the roles of metalloproteinases in cartilage and bone damage?

A role for metalloproteinases in the pathological destruction in diseases such as rheumatoid arthritis and osteoarthritis, and the irreversible nature of the ensuing cartilage and bone damage, have been the focus of much investigation for several decades. This has led to the development of broad spectrum metalloproteinase inhibitors as potential therapeutics. More recently it has been appreciated that several families of zinc dependent proteinases play significant and varied roles in the biology of the resident cells in these tissues, orchestrating development, remodelling, and subsequent pathological processes. They also play key roles in the activity of inflammatory cells. The task of elucidating the precise role of individual metalloproteinases is therefore a burgeoning necessity for the final design of metalloproteinase inhibitors if they are to be employed as therapeutic agents.     

Important roles of PI3Kγ in osteoclastogenesis and bone homeostasis

G protein-coupled receptor-regulated PI3Kγ is abundantly expressed in myeloid cells and has been implicated as a promising drug target to treat various inflammatory diseases. However, its role in bone homeostasis has not been investigated, despite the fact that osteoclasts are derived from myeloid lineage. We therefore carried out thorough bone phenotypic characterization of a PI3Kγ-deficient mouse line and found that PI3Kγ-deficient mice had high bone mass. Our analyses further revealed that PI3Kγ deficiency did not affect bone formation because no significant changes in osteoblast number and bone formation rate were observed. Instead, the lack of PI3Kγ was associated with decreased bone resorption, as evidenced by decreased osteoclast number in vivo and impaired osteoclast formation in vitro. The decreased osteoclast formation was accompanied by down-regulated expression of osteoclastogenic genes, compromised chemokine receptor signaling, and an increase in apoptosis during osteoclast differentiation. Together, these data suggest that PI3Kγ regulates bone homeostasis by modulating osteoclastogenesis. Our study also suggests that inhibition of PI3Kγ, which is being considered as a potential therapeutic strategy for treating chronic inflammatory disorders, may result in an increase in bone mass.     

Is HIV sequestered in bone? Possible implications of virological and immunological findings in some HIV-infected patients with bone disease

To determine the prevalence of CD4 lymphocyte levels less than 350 cells/mm3 accompanying viral loads (VL) less than 500 copies/ml (discordant CD4 lymphocyte levels/VL) in HIV-infected men with bone pathologies, we conducted a review of the records of 3512 men. We found discordant CD4 lymphocyte levels/VL in 26 (36.1%) out of 72 with bone pathologies, and in 704 (20.5%) out of 3440 without bone pathologies (P < 0.01), and concluded that HIV sequestered in bone was a possible explanation.     

Paget’s disease of bone resembling bone metastasis from gastric cancer

A 74-year-old man had an endoscopic type 0′-IIc tumor in the upper gastric body on the greater curvature and biopsy showed the tumor to be a well-differentiated adenocarcinoma (Group 5). He was referred to us for endoscopic submucosal dissection (ESD). Endoscopy revealed fold convergency, fold swelling, and fusion of the fold, indicating tumor invasion into the submucosa, which was outside the indications for ESD. In addition, there was an increase of serum bone-type alkaline phosphatase (ALP-III and ALP-IV) and urinary cross-linked N-terminal telopeptide of type I collagen (a bone metabolism marker), while ¹⁸F-fluorodeoxyglucose positron emission tomography showed increased uptake in the left pelvis and Th10, suggesting bone metastases. We first diagnosed gastric cancer with bone metastases; however, the symptoms suggested pathological bone fracture and no bone pain. Therefore, a computed tomography-guided aspiration bone biopsy was performed to exclude the possibility of Paget’s disease of bone. Biopsy specimens revealed no tumor and a mosaic pattern. No increased uptake of ¹⁸F-FAMT (L-[3-¹⁸F] α-methyltyrosine) supported a diagnosis of no bone metastases from gastric cancer. We finally diagnosed gastric cancer accompanied by Paget’s disease of bone and performed a laparoscopy-assisted proximal gastrectomy. The pathological diagnosis was U less 0-IIb, and U post 0-IIc ypT1a (M) N0H0P0M0 yp stage IA. In gastric cancer patients with suspected bone metastasis, we also need to consider Paget’s disease of bone.     

Patterns of pain in Paget’s disease of bone and their outcomes on treatment with pamidronate

Two-thirds of patients with Pagets disease seeking medical attention present with pain. We studied patterns of pagetic pain in relation to physical activity, and the effect of coexistent osteoarthritis (OA)/pagetic arthropathy on pain and physical activity before and after treatment with pamidronate. Patients with lower-segment Pagets disease (lumbar spine, pelvis or lower limbs), raised alkaline phosphatase (ALP), and pain as a symptom were included. Two subgroups were identified based on the absence (P group), or presence (POA group) of radiological OA in the lower segment. They received 2–4 fortnightly infusions of pamidronate 30–60 mg and were followed up at 6 weeks, 3 months and 6 months. Outcome measures were visual analog scales for pain at rest, on standing, on walking and at night; standing time, walking distance, 50-yard walking time, and ALP. Twenty-five patients (12 men, 13 women, mean age 70.1±1.9 years), received a mean of 142±9.7 mg of pamidronate. The P group had higher mean ALP (p=0.003) and higher scores for pain (not significant) at baseline than the POA group. Compared to baseline, P group had significant improvements (p<0.01) at 6 months in rest pain, standing pain and walking pain. The POA group had non-significant changes in pain at 6 months. ALP improved significantly at 6 months in both subgroups (p<0.01). The whole group also improved at 6 months in standing time (55.7%, not significant), walking distance (33.9%, not significant), and 50-yard walking time (24.2%, p<0.05). Pagets patients with coexistent joint disease had less severe pain and bone disease at baseline than those without coexistent joint disease, and responded less well to pamidronate, although they did have significant improvement in ALP levels. Radiographic assessment for coexisting joint disease prior to treatment might improve prognostication from the patients point of view, and improve treatment compliance.Abbreviations ALP alkaline phosphatase - OA Osteoarthritis     

Dietary α-ketoglutarate reduces gastrectomy-evoked loss of calvaria and trabecular bone in female rats

Objective. Surgical removal of the stomach (gastrectomy, Gx) leads to osteopenia in animals and in humans. In the rat, Gx adversely affects calvaria and trabecular bone. α-Ketoglutarate (AKG) is a precursor of hydroxyproline – the most abundant amino acid in bone collagen. The purpose of this study was to investigate the effects of dietary AKG on Gx-induced osteopenia. Material and methods. Twenty female Sprague-Dawley rats were subjected to Gx and divided between two groups: Gx+AKG in the drinking water and Gx+Vehicle (i.e. drinking water without AKG). Another 20 rats were sham-operated and divided between two groups: Sham+AKG and Sham+Vehicle. The daily dose of AKG was 0.43 g per 100 g rat. All the rats were killed 8 weeks later and the calvariae, femora and tibiae were collected. The integrity of the calvariae was analysed planimetrically, following transillumination and photography. The bone mineral content (BMC) and bone mineral density (BMD) were measured in the right femorae and tibiae (bone densitometry), leaving the left femorae and tibiae to be analysed histomorphometrically (measurement of trabecular bone volume and trabecular fractal dimension). Results. Gx caused calvarial bone degradation, reduced trabecular bone (femur and tibia) and impaired trabecular architecture. In addition, Gx lowered the femoral/tibial BMC and BMD (mainly cortical bone). Dietary AKG counteracted the Gx-evoked impairment of calvaria and trabecular bone but failed to affect the BMC and the BMD in either sham- operated or Gx rats. Conclusions. Gx resulted in loss of calvarial, trabecular and cortical bone in the rat. AKG counteracted the effect of Gx on calvaria and trabecular bone but not on cortical bone.     

Prospective study of histomorphometry,biochemical bone markers and bone densitometric response to pamidronate in β-thalassaemia presenting with osteopenia-osteoporosis syndrome

This study aimed to evaluate bone remodelling disorders in thalassaemia by using pamidronate (PD) infusion with or without hormone replacement therapy (HRT) as a diagnostic-therapeutic tool. In this prospective study, 24 adult thalassaemia major (TM) and 10 thalassaemia intermedia (TI) patients received either PD and HRT or HRT only (controls) for 3 years. Eugonadal patients with TI had PD only. Bone remodelling was assessed by dual energy X ray absorptiometry (DXA scan), type 1-collagen biochemical bone markers (BBM) and histomorphometry of iliac crest biopsy before and after PD. As a group, thalassaemics had a significant improvement in spinal and femoral bone mineral density Z scores following PD (P < 0·01) compared to the controls. Although BBM were comparable pre-therapy, they were significantly lower in the PD cohort (P < 0·001) compared to the control group. All patients had osteopenia, diminished osteoid formation and bone volume on histomorphometry pre-therapy with high turnover bone disease (HTO) in TM and low-turnover disease (LTO) in TI. In TM, bone volume improved significantly, whereas TI patients showed little or no response to PD. In conclusion, histomorphometry data suggest that TM patients have a distinct pathology of high turnover bone disease compared to TI patients, who have low-turnover disease.     

Perinatal maternal dietary supplementation of ω3-fatty acids transiently affects bone marrow microenvironment, osteoblast and osteoclast formation, and bone mass in male offspring

It is increasingly evident that micronutrient environment experienced before birth and in infancy is important for achieving optimal bone mass by adolescence and maintaining bone health. This study determined whether maternal supplementation with ω3-polyunsaturated fatty acids (n3FA) improved offspring bone growth and adult bone mass. Female rats were fed a diet containing 0.1% (control, n = 10) or 1% (n3FA, n = 11) docosahexanoic acid (DHA) during pregnancy and lactation. Offspring were weaned onto a control rat chow diet. Tibial growth plate and metaphysis structure, osteoblast/osteoclast density and differentiation, and gene expression were assessed in offspring at 3 wk (weaning), 6 wk (adolescent), and 3 months (adult). Maternal n3FA supplementation elevated offspring plasma n3FA levels at 3 and 6 wk. Although total growth plate heights were unaffected at any age, the resting zone thickness was increased in both male and female offspring at 3 wk. In n3FA males, but not females, bone trabecular number and thickness were increased at 3 wk but not other ages. The wk 3 n3FA males also exhibited an increased bone volume, an increased osteoblast but decreased osteoclast density, and lower expression of osteoclastogenic cytokines receptor activator of nuclear factor-κB ligand, TNF-α, and IL-6. No effects were seen at 6 wk or 3 months in either sex. Thus, perinatal n3FA supplementation is associated with increased bone formation, decreased resorption, and a higher bone mass in males, but not in females, at weaning; these effects do not persist into adolescence and adulthood and are unlikely to produce lasting improvements in bone health.     

Paget's disease of bone or osteopetrosis?

We report a previously undescribed case of diffuse, scan-negative, and low active form of bone disease carrying clinical, x-ray, and biochemistry signs of Paget's disease of bone, which is analyzed in comparison with different forms of osteopetrosis.     

Hepatic differentiation capability of rat bone marrow-derived mesenchymal stem cells and hematopoietic stem cells

AIM:To investigate the different effects of mesenchymalstem cells(MSCs)and hematopoietic stem cells(HSCs)onhepatic differentiation.METHODS:MSCs from rat bone marrow were isolated andcultured by standard methods.HSCs from rat bone marrowwere isolated and purified by magnetic activated cell sorting.Both cell subsets were induced.Morphology,RT-PCR andimmunocytochemistry were used to identify the hepaticdifferentiation grade.RESULTS:MSCs exhibited round in shape after differentiation,instead of fibroblast-like morphology before differentiation.Albumin mRNA and protein were expressed positively in MSCs,without detection of alpha-fetoprotein(AFP).HSCs werepolygonal in shape after differentiation.The expression ofalbumin signal decreased and AFP signal increased.Theexpression of CK18 was continuous in MSCs and HSCs bothbefore and after induction.CONCLUSION:Both MSCs and HSCs have hepatic differentiationcapabilities.However,their capabilities are not the same.MSCs can differentiate into mature hepatocyte-like cells,never expressing early hepatic specific genes,while Thy-1.1~ cells are inclined to differentiate into hepatic stem cell-likecells,with an increasing AFP expression and a decreasingalbumin signal.CK18 mRNA is positive in Thy-1.1~ cellsand MSCs,negative in Thy-1.1 cells.It seems that CK18has some relationship with Thy-1.1 antigen,and CK18 maybe a predictive marker of hepatic differentiation capability.     

Proliferation and bone marrow engraftment of AML blasts is dependent on β-catenin signalling

B-catenin is the central effector molecule of the canonical Wnt signalling pathway, which controls self-renewal of haematopoietic stem cells. Deregulation of this pathway occurs in various malignancies including myeloid leukaemias. The present study examined the functional outcome of stable β-catenin down-regulation through lentivirus-mediated expression of short hairpin RNA (shRNA). Reduction of the β-catenin levels in acute myeloid leukaemia (AML) cell lines and patient samples decelerated their in vitro proliferation ability without affecting cell viability. Transplantation of leukaemic cells with control or reduced levels of β-catenin in non-obese diabetic severe combined immunodeficient animals indicated that, while the immediate homing of the cells was unaffected, the bone marrow engraftment was directly dependent on β-catenin levels. Subsequent examination of bone sections revealed that β-catenin was implicated in the localization of AML to the endosteum. Examination of adhesion molecule expression before and after transplantation, revealed down-regulation of CD44 expression, accompanied by reduced in vitro adhesion. Gene expression analysis disclosed the presence of an autocrine compensatory mechanism, which responds to the reduced β-catenin levels by altering the expression of positive and negative pathway regulators. In conclusion, our study showed that β-catenin comprises an integral part of AML cell proliferation, cell cycle progression, and adhesion, and influences disease establishment in vivo.     

Incidence,etiology and bone marrow characteristics of non‐chemotherapy‐induced agranulocytosis

Abstract

Objective: Agranulocytosis is a rare but fatal condition. The majority of cases are associated with drugs. However, in‐patient incidences and the relationship between clinical outcomes and bone marrow characteristics have not been established.

Methods: We conducted a retrospective study in a university hospital. A total of 38 in‐patients diagnosed with agranulocytosis were analyzed.

Results: The average incidence of agranulocytosis in Songklanagarind Hospital between 1993 and 2007 was 0·98 cases per 10?000 admissions per year. Antimicrobial agents were the most common etiology (63% of patients) and antithyroid agents were the second most common (13·6%). Two patterns of bone marrow were noted: type I was characterized by a left‐shifted granulopoiesis and type II was recognized as having hypocellular bone marrow with markedly reduced granulocyte precursors. A significantly higher mortality was associated with type II.

Conclusion: Antimicrobial agents are the most common cause and the rare granulocyte precursors in bone marrow are associated with higher mortality rates.