Pathogenesis of glucocorticoid-induced osteoporosis and options for treatment

Simultaneous augmentation of muscle and bone by locomomimetism through calcium-PGC-1α signaling

Impaired locomotion has been extensively studied worldwide because those afflicted with it have a potential risk of becoming bedridden. Physical exercise at times can be an effective remedy for frailty, but exercise therapy cannot be applied in all clinical cases. Medication is safer than exercise, but there are no drugs that reinforce both muscle and bone when administered alone. Multiple medications increase the risk of adverse events; thus, there is a need for individual drugs targeting both tissues. To this end, we established a novel sequential drug screening system and identified an aminoindazole derivative, locamidazole (LAMZ), which promotes both myogenesis and osteoblastogenesis while suppressing osteoclastogenesis. Administration of this drug enhanced locomotor function, with muscle and bone significantly strengthened. Mechanistically, LAMZ induced Mef2c and PGC-1α in a calcium signaling-dependent manner. As this signaling is activated upon physical exercise, LAMZ mimics physical exercise. Thus, LAMZ is a promising therapeutic drug for locomotor diseases, including sarcopenia and osteoporosis.

Long-term outcomes of conventional and novel steroid replacement therapy on bone health in primary adrenal insufficiency

Steroids affect bone health causing osteoporosis and fractures. The study aims to compare dual-release hydrocortisone (DR-HC) and conventional steroids on bone metabolism in patients with primary adrenal insufficiency (PAI). Thirty-five patients with PAI on conventional steroids (group A) and 35 patients switched to DR-HC (group B), consecutively referred at our hospital, were evaluated at baseline and after 18, 36 and 60 months of treatment. After 60 months of follow-up, patients in group A had a significant increase in body mass index (p = 0.004) and waist circumference (WC) (p = 0.026) and a significant decrease in osteocalcin (p = 0.002), bone alkaline phosphatase (p = 0.029), lumbar spine bone mass density (BMD) T and Z scores (p < 0.001 and p = 0.001, respectively) and vertebral fractures rate (p = 0.021) than baseline. By contrast, patients in group B had a significant decrease in WC (p = 0.047) and increase in bone alkaline phosphatase (p = 0.019), lumbar spine BMD T score (p = 0.032), femoral neck BMD T and Z scores (p = 0.023 and p = 0.036, respectively) than baseline. Long-term conventional steroid replacement therapy is associated with a decrease in BMD, notably at lumbar spine, and increase in vertebral fractures rate. By contrast, DR-HC treatment is associated with improvement of BMD.

Long-Term Outcomes of Congenital Adrenal Hyperplasia

A plethora of negative long-term outcomes have been associated with congenital adrenal hyperplasia (CAH). The causes are multiple and involve supra-physiological gluco- and mineralocorticoid replacement, excess adrenal androgens both intrauterine and postnatal, elevated steroid precursor and adrenocorticotropic hormone levels, living with a congenital condition as well as the proximity of the cytochrome P450 family 21 subfamily A member 2 (CYP21A2) gene to other genes. This review aims to discuss the different long-term outcomes of CAH.

The Impacts of COVID-19 on Musculoskeletal Health

PURPOSE OF REVIEW

Although COVID-19 was originally characterized as a respiratory disease, recent findings have shown lingering side effects in those who have recovered, and much is still unknown about the long-term consequences of the illness. Thus, the potential of unearthing multi-system dysfunction is high, with current data revealing significant impacts on musculoskeletal health.

RECENT FINDINGS

Multiple animal models of COVID-19 infection have revealed significant post-infection bone loss at several different skeletal sites. While how this loss occurred is unknown, this current review discusses the primary bone loss studies, and examines the possible mechanisms of action including: direct infection of bone marrow macrophages or hematopoietic progenitors, a proinflammatory response as a result of the COVID-19 induced cytokine storm, and/or a result of hypoxia and oxidative stress. This review will further examine how therapeutics used to treat COVID-19 affect the skeletal system. Finally, this review will examine the possible consequence that delayed care and limited healthcare accessibility has on musculoskeletal-related patient outcomes. It is important to investigate the potential impact COVID-19 infection has on musculoskeletal health.

An antagonistic monoclonal anti-Plexin-B1 antibody exerts therapeutic effects in mouse models of postmenopausal osteoporosis and multiple sclerosis

Osteoporosis and multiple sclerosis are highly prevalent diseases with limited treatment options. In light of these unmet medical needs, novel therapeutic approaches are urgently sought. Previously, the activation of the transmembrane receptor Plexin-B1 by its ligand semaphorin 4D (Sema4D) has been shown to suppress bone formation and promote neuroinflammation in mice. However, it is unclear whether inhibition of this receptor–ligand interaction by an anti–Plexin-B1 antibody could represent a viable strategy against diseases related to these processes. Here, we raised and systematically characterized a monoclonal antibody directed against the extracellular domain of human Plexin-B1, which specifically blocks the binding of Sema4D to Plexin-B1. In vitro, we show that this antibody inhibits the suppressive effects of Sema4D on human osteoblast differentiation and mineralization. To test the therapeutic potential of the antibody in vivo, we generated a humanized mouse line, which expresses transgenic human Plexin-B1 instead of endogenous murine Plexin-B1. Employing these mice, we demonstrate that the anti–Plexin-B1 antibody exhibits beneficial effects in mouse models of postmenopausal osteoporosis and multiple sclerosis in vivo. In summary, our data identify an anti–Plexin-B1 antibody as a potential therapeutic agent for the treatment of osteoporosis and multiple sclerosis.

Delayed initiation of anti-osteoporosis medications increases subsequent hip and vertebral fractures in patients on long-term glucocorticoid therapy: A nationwide health insurance claims database study in Japan

PURPOSE

Early initiation of anti-osteoporosis medications (AOMs) is recommended for patients on long-term glucocorticoid (GC) therapy. This study aimed to examine whether physicians prescribe AOMs as soon as GC therapy is initiated, and whether a delay in AOM initiation affects hip and vertebral fracture incidence, using the nationwide health insurance claims database of Japan (NDBJ).

METHODS

Patients aged ≥50 years who were prescribed GC (≥5 mg/day prednisolone or equivalent) for ≥90 days and who were followed for AOM use and hip and vertebral fracture events for the subsequent 1080 days in 2012-2018 were selected from NDBJ. Delay in AOM initiation was defined as the number of days without AOMs following GC therapy initiation. Associations between delay in AOM initiation and hip and vertebral fracture risk were evaluated by Cox proportional hazards regression.

RESULTS

In total, 92,143 women and 94,772 men were included in the analysis, of which only 39.3% of women and 28.5% of men received AOMs within 90 days from GC therapy initiation. Approximately, 15% of hip fractures and 30% of vertebral fractures occurred before AOM initiation in patients with delayed AOM initiation. HRs of both fractures were significantly greater in patients with a longer delay in AOM initiation (p value for trend<0.001). After excluding patients who had fractures before AOM initiation, the magnitude of HRs significantly decreased, and HR trends for hip fracture became insignificant.

CONCLUSIONS

Delayed initiation of AOMs may result in increased fracture events, which may be reduced by early initiation of AOMs.

Effect of AZD4017, a Selective 11β-HSD1 Inhibitor, on Bone Turnover Markers in Postmenopausal Osteopenia

CONTEXT

The causative link between circulating glucocorticoid excess and osteoporosis is well-established. The enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), which increases local cortisol production, is expressed in human osteoblasts and its activity increases with age.

OBJECTIVE

We hypothesized that local 11β-HSD1 might mediate an age-related decrease in bone formation and that selective 11β-HSD1 inhibition may enhance bone formation.

METHODS

A dual-center, phase II, randomized, double-blind, placebo-controlled trial of 90 days' treatment with AZD4017 (a selective 11β-HSD1 inhibitor) was conducted in 55 postmenopausal women with osteopenia. Participants received 400 mg oral AZD4017 twice daily vs matched placebo over 90 days. The primary outcome measure was the impact on the bone formation marker osteocalcin. Secondary objectives included correlation with 11β-HSD1 activity.

RESULTS

At 90 days, osteocalcin levels did not differ between treatment groups: active (mean 22.3 [SD 8.6] ng/mL, n = 22) and placebo (21.7 [SD 9.2] ng/mL, n = 24), with a baseline-adjusted treatment effect of 0.95 (95% CI: -2.69, 4.60). The results from the urinary [THF + alloTHF]/THE ratio (index of 11β-HSD1 activity) and the urinary cortisol/cortisone ratio (index of 11β-HSD2 activity) confirmed a > 90% inhibition of 11β-HSD1 but no change in activity of 11β-HSD2.

CONCLUSION

This trial demonstrates that AZD4017 selectively inhibits 11β-HSD1 activity in vivo in a safe and reversible manner. Following 90 days of treatment, there is no effect on bone formation, indicating that the relative impairment of bone mineral density in postmenopausal women is not mediated by local intracellular production of cortisol under normal physiological concentrations.

Glucocorticoid-induced expansion of classical monocytes contributes to bone loss

Classical monocytes are commonly involved in the innate inflammatory response and are the progenitors of osteoclasts. Excess endogenous glucocorticoids (GCs) can increase the levels of classical monocytes in blood and bone marrow. The role of this cell population in high-dose exogenous GC-induced osteoporosis (GIOP) remains to be elucidated. In this study, GIOP was established in rats and mice by daily methylprednisolone injection, and monocyte subsets were analyzed by flow cytometry. We demonstrated that classical monocytes accumulate in bone marrow during GIOP. Similarly, the monocyte proportion among bone marrow nucleated cells was also increased in patients with steroid treatment history. We sorted classical monocytes and analyzed their transcriptional profile in response to GCs by RNA sequencing. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed that classical monocytes isolated from GC-treated rats exhibited osteoclast differentiation potential. Deletion of classical monocytes by clodronate liposome treatment prevented GIOP via inhibition of osteoclastogenesis and restoration of CD31^Hiendomucin^Hi vessels. Regarding the molecular mechanism, classical monocytes express high levels of glucocorticoid receptors. In vitro treatment with GCs increased both the percentage and absolute number of monocytes and promoted their proliferation. In summary, classical monocytes mediated GC-induced bone loss and are a potential target for therapeutic intervention in GIOP treatment.

Bone mass and microarchitecture in T2DM patients and corticosteroids therapy: the Bushehr Elderly Health program

Purpose

Our study examined whether T2DM and glucocorticoids treatment affect bone quality and quantity that are measured by Bone Mineral Density (BMD) and Trabecular Bone Score (TBS).

Materials & methods

Participants in this study were 2294 women and men aged over 60 years who participated in stage II of the Bushehr Elderly Health (BEH) program. Patients with T2DM and those who received glucocorticoids were included. BMD was detected using the DXA method and the TBS of L1-L4 was evaluated by TBS iNsight® software. To evaluate the correlation between TBS and BMD levels with diabetes and taking corticosteroids sex-specific multivariable linear regression models were appplied.

Results

TBS and BMD were not significantly different in those who had received glucocorticoids versus those who did not.T2DM revealed a significant association with both BMD and TBS in men (beta = 0.12, p < 0.001 and beta = 0.063, p = 0.03, respectively). BMD values were significantly higher in diabetic women (beta = 0.073, p < 0.01). BMI had a significant association with both TBS and BMD but in an opposite direction, in women and men (BMD: beta = -0.22, -0.24, and regarding TBS: beta = 0.37, 0.25, all p-values < 0.001).

Conclusion

Our findings showed that T2DM had major effects on BMD in both men and women. However, T2DM only affects TBS in men. Furthermore, neither BMD nor TBS were affected by GC intake in men or women.Based on the variable importance of covariates, BMI was the most influential factor on both BMD and TBS, although in opposite directions, in both sexes.

Intra-articular injection of triamcinolone acetonide sustains macrophage levels and aggravates osteophytosis during degenerative joint disease in mice

BACKGROUND AND PURPOSE

Corticosteroids such as triamcinolone acetonide (TAA) are potent drugs administered intra-articularly as an anti-inflammatory therapy to relieve pain associated with osteoarthritis (OA). However, the ability of early TAA intervention to mitigate OA progression and modulate immune cell subsets remains unclear. Here, we sought to understand the effect of early intra-articular injection of TAA on OA progression, local macrophages, and peripheral blood monocytes.

EXPERIMENTAL APPROACH

Degenerative joint disease was induced by intra-articular injection of collagenase into the knee joint of male C57BL/6 mice. After 1 week, TAA or saline was injected intra-articularly. Blood was taken throughout the study to analyse monocyte subsets. Mice were killed at days 14 and 56 post-induction of collagenase-induced OA (CiOA) to examine synovial macrophages and structural OA features.

KEY RESULTS

The percentage of macrophages relative to total live cells present within knee joints was increased in collagenase- compared with saline-injected knees at day 14 and was not altered by TAA treatment. However, at day 56, post-induction of CiOA, TAA-treated knees had increased levels of macrophages compared with the knees of untreated CiOA-mice. The distribution of monocyte subsets present in peripheral blood was not altered by TAA treatment during the development of CiOA. Osteophyte maturation was increased in TAA-injected knees at day 56.

CONCLUSION AND IMPLICATIONS

Intra-articular injection of TAA increases long-term synovial macrophage numbers and osteophytosis. Our findings suggest that TAA accentuates the progression of osteoarthritis-associated features when applied to an acutely inflamed knee.

Zuo-Gui-Wan Aqueous Extract Ameliorates Glucocorticoid-Induced Spinal Osteoporosis of Rats by Regulating let-7f and Autophagy

OBJECTIVE

This study proposes to explore the protective effect of Zuo-Gui-Wan (ZGW) aqueous extract on spinal glucocorticoid-induced osteoporosis (GIOP) in vivo and in vitro, and the underlying mechanisms of ZGW in GIOP and osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) were conducted.

METHODS

In vivo, SD rats were randomly divided into three groups: control group (CON), dexamethasone (DEXM) group, and ZGW group, which were given vehicle, DEXM injection, and ZGW intragastric administration at the same time. Vertebral bone microarchitecture, biomechanics, histomorphology, serum AKP activity, and the autophagosome of osteoblasts were examined. The mRNA expressions of let-7f, autophagy-associated genes (mTORC1, Beclin-1, ATG12, ATG5, and LC3), Runx2, and CTSK were examined. In vitro, the let-7f overexpression/silencing vector was constructed and transfected to evaluate the osteogenic differentiation of BMSCs. Western blot was employed to detect the expression of autophagy-associated proteins (ULK2, ATG5, ATG12, Beclin-1, LC3).

RESULTS

In vivo, ZGW promoted the bone quantity, quality, and strength; alleviated histological damage; increased the serum AKP activity; and reduced the autophagosome number in osteoblasts. Moreover, ZGW increased the let-7f, mTORC1, and Runx2 mRNA expressions and reduced the Beclin-1, ATG12, ATG5, LC3, and CTSK mRNA expressions. In vitro, bioinformatics prediction and dual luciferase reporter gene assay verified that let-7f targeted the binding to ULK2 and negatively regulated the ULK2 expression. Furthermore, by let-7f overexpression/silencing, ZGW may promote osteoblast differentiation of BMSCs by regulating let-7f and autophagy as evidenced by Western blot (ULK2, ATG5, ATG12, Beclin-1, LC3).

CONCLUSIONS

ZGW may ameliorate GC-induced spinal osteoporosis by promoting osteoblast differentiation of BMSCs by activation of let-7f and suppression of autophagy.

Guideline adherence by physicians for management of glucocorticoid-induced osteoporosis in Japan: a nationwide health insurance claims database study

Risk of fracture due to glucocorticoid-induced osteoporosis (GIO) can be reduced by anti-osteoporosis (OP) medications. The proportion of patients on long-term glucocorticoid therapy who received anti-OP medications according to the GIO management guidelines has increased in recent years, but is still suboptimal.

INTRODUCTION

Adherence of physicians to guidelines for glucocorticoid (GC)-induced osteoporosis (GIO) management is currently unclear. This study aimed to clarify the state of guideline adherence by physicians in Japan and identify factors associated with guideline adherence using a nationwide health insurance claims database (NDBJ).

METHODS

Patients aged ≥ 50 years who were prescribed GC for ≥ 90 days after 180 days without a GC prescription and who were followed up for osteoporosis (OP) management for the subsequent 360 days during the period spanning 2012-2018 were selected from the NDBJ. Guideline adherence was evaluated with the proportion of patients who received OP management as recommended by the Japanese guidelines. Information on previous vertebral and hip fractures, dementia, and polypharmacy was obtained. Factors associated with OP management were evaluated by logistic regression analysis.

RESULTS

A total of 512,296 patients were considered to be at high risk of fracture according to the guidelines. Proportions of patients receiving OP management (BMD testing or anti-OP medications) have increased in recent years. In 2017, 33.7% of men and 55.3% of women received OP management in the initial 90 days of GC therapy. Female sex, previous anti-OP medications, polypharmacy, and higher GC dose were significantly associated with receiving OP management, while dementia showed an inverse association. A prior history of hip fracture, a strong risk factor for future fracture, was not significantly associated with receiving OP management.

CONCLUSIONS

Although guideline adherence by physicians has increased in recent years, it remains suboptimal. Further efforts to improve guideline adherence are necessary.

TRIAL REGISTRATION NUMBER

The present study is not registered.

Early-Onset Osteoporosis

Osteoporosis is a skeletal disorder with enhanced bone fragility, usually affecting the elderly. It is very rare in children and young adults and the definition is not only based on a low BMD (a Z-score < - 2.0 in growing children and a Z-score ≤ - 2.0 or a T-score ≤ - 2.5 in young adults) but also on the occurrence of fragility fractures and/or the existence of underlying chronic diseases or secondary factors such as use of glucocorticoids. In the absence of a known chronic disease, fragility fractures and low BMD should prompt extensive screening for secondary causes, which can be found in up to 90% of cases. When fragility fractures occur in childhood or young adulthood without an evident secondary cause, investigations should explore the possibility of an underlying monogenetic bone disease, where bone fragility is caused by a single variant in a gene that has a major role in the skeleton. Several monogenic forms relate to type I collagen, but other forms also exist. Loss-of-function variants in LRP5 and WNT1 may lead to early-onset osteoporosis. The X-chromosomal osteoporosis caused by PLS3 gene mutations affects especially males. Another recently discovered form relates to disturbed sphingolipid metabolism due to SGMS2 mutations, underscoring the complexity of molecular pathology in monogenic early-onset osteoporosis. Management of young patients consists of treatment of secondary factors, optimizing lifestyle factors including calcium and vitamin D and physical exercise. Treatment with bone-active medication should be discussed on a personalized basis, considering the severity of osteoporosis and underlying disease versus the absence of evidence on anti-fracture efficacy and potential harmful effects in pregnancy.

Development and validation of a novel screening tool for osteoporosis in older US adults: The NHANES cross-sectional study

PURPOSE

Osteoporosis (OP) is a common disease among adults aged >50 years. At present, the main approach to screen or to diagnosis OP is mainly via bone mineral density (BMD) testing, which might not be optimal for OP screening. This study aimed to develop and validate a convenient and effective prediction model for screening OP based on the demographic information, medical history, and lifestyle habits in the elderly in the United States.

METHODS

All data were collected from the National Health and Nutrition Survey database. Participants aged ≥50 years with complete BMD data were included in this study. Twelve candidate predictors were initially selected to develop the prediction model. Final predictors screening and model development were based on multivariate logistic regression. Model discrimination (C statistic) and calibration (Brier scores) were calculated to evaluate the performance of the model. Internal validation was performed using the bootstrap resampling technique, and external validation was based on the validation cohort.

RESULTS

The screening tool was developed with individual patient data from 1941 patients and validated with data from 1947 patients after the development of the model. Seven predictors (patient age, sex, race, body mass index, physical activity, sleep duration, and history of fracture) were included in the final prediction model, and the final model had a C statistic of 0.849 [95% confidence interval (CI): 0.820-0.878] and Brier scores of 0.062 [95% CI: 0.054-0.070] on the development cohort. For the validation of the developed model, the results showed a C statistic >0.800 and Brier scores <0.070, irrespective of internal validation or external validation.

CONCLUSIONS

A novel screening tool for OP in the elderly, which has excellent discrimination and useful calibration, has been developed and externally validated. Considering its simplicity, generalizability, and accuracy, this tool has the potential to become a practical mean for the elderly to screen OP.

Targeting Sirt1, AMPK, Nrf2, CK2, and Soluble Guanylate Cyclase with Nutraceuticals: A Practical Strategy for Preserving Bone Mass

There is a vast pre-clinical literature suggesting that certain nutraceuticals have the potential to aid the preservation of bone mass in the context of estrogen withdrawal, glucocorticoid treatment, chronic inflammation, or aging. In an effort to bring some logical clarity to these findings, the signaling pathways regulating osteoblast, osteocyte, and osteoclast induction, activity, and survival are briefly reviewed in the present study. The focus is placed on the following factors: the mechanisms that induce and activate the RUNX2 transcription factor, a key driver of osteoblast differentiation and function; the promotion of autophagy and prevention of apoptosis in osteoblasts/osteoclasts; and the induction and activation of NFATc1, which promotes the expression of many proteins required for osteoclast-mediated osteolysis. This analysis suggests that the activation of sirtuin 1 (Sirt1), AMP-activated protein kinase (AMPK), the Nrf2 transcription factor, and soluble guanylate cyclase (sGC) can be expected to aid the maintenance of bone mass, whereas the inhibition of the serine kinase CK2 should also be protective in this regard. Fortuitously, nutraceuticals are available to address each of these targets. Sirt1 activation can be promoted with ferulic acid, N1-methylnicotinamide, melatonin, nicotinamide riboside, glucosamine, and thymoquinone. Berberine, such as the drug metformin, is a clinically useful activator of AMPK. Many agents, including lipoic acid, melatonin, thymoquinone, astaxanthin, and crucifera-derived sulforaphane, can promote Nrf2 activity. Pharmacological doses of biotin can directly stimulate sGC. Additionally, certain flavonols, notably quercetin, can inhibit CK2 in high nanomolar concentrations that may be clinically relevant. Many, though not all, of these agents have shown favorable effects on bone density and structure in rodent models of bone loss. Complex nutraceutical regimens providing a selection of these nutraceuticals in clinically meaningful doses may have an important potential for preserving bone health. Concurrent supplementation with taurine, N-acetylcysteine, vitamins D and K2, and minerals, including magnesium, zinc, and manganese, plus a diet naturally high in potassium, may also be helpful in this regard.

Nutritional recommendations for patients undergoing prolonged glucocorticoid therapy

Glucocorticoid (GC) therapy is a common treatment used in rheumatic and autoimmune diseases, owing to its anti-inflammatory and immunosuppressive effects. However, GC therapy can also induce a number of adverse effects, including muscle and bone loss, hypertension, metabolic perturbations and increased visceral adiposity. We review available evidence in this area and provide nutritional recommendations that might ameliorate these adverse effects. Briefly, optimizing calcium, vitamin D, sodium and protein intake and increasing consumption of unprocessed and minimally processed foods, while decreasing the consumption of ultra-processed foods, might counteract some of the specific challenges faced by these patients. Importantly, we identify a dearth of empirical data on how nutritional intervention might impact health-related outcomes in this population. Further research is required to investigate the clinical and therapeutic efficacy of these theory-based recommendations.

Pathological changes in the osteoarticular system during COVID-19 drug therapy (review of literature)

The recommended drugs for the treatment of COVID-19 are, on the one hand, experimental in nature, but at the same time, they have many side effects that cause long-term complications in organs and systems, including osteoarticular. Based on the analysis of modern domestic and foreign literature, to determine the effect of not only the new coronavirus infection COVID-19, but also the drugs used to treat it, on the human osteoarticular system. In the course of the study, a scientific search was made for publications in the electronic databases PubMed, MedLine and e-Library for the period from January 2000 to October 2021 for the main keywords. Due to successive “waves” of the COVID-19 pandemic, the number of patients receiving non-specific therapy, including corticosteroids, will increase in the coming years. Preliminary data on COVID-19 and similar trends during the Sars-COV-1 epidemic of 2003 show that the pathogenesis of Sars- Cov-2 and its treatment with high doses of corticosteroids may increase the risk of osteonercosis in patients, which will inevitably lead to an increase in orthopedic diseases in patients not only the middle age group, but also young patients in the near future. Currently, studies are required aimed at risk stratification, studying the pathogenesis of damage to the musculoskeletal system after COVID-19 and the effectiveness of preventive and therapeutic measures in such patients.

Risk Factors for and Effects of Persistent and Severe Hypophosphatemia Following Ferric Carboxymaltose

CONTEXT

Hypophosphatemia, osteomalacia, and fractures are complications of certain intravenous iron formulations.

OBJECTIVE

This study investigated risk factors for incident, severe, and persistent hypophosphatemia, and associated alterations in bone and mineral biomarkers following intravenous iron treatment.

METHODS

We analyzed data from the PHOSPHARE-IDA randomized clinical trials, comprising 245 patients aged 18 years or older with iron deficiency anemia at 30 outpatient clinics in the United States who received intravenous ferric carboxymaltose (FCM) or ferric derisomaltose (FDI). Outcome measures included serum phosphate, intact fibroblast growth factor-23 (iFGF23), 1,25-dihydroxyvitamin D (1,25(OH)2D), ionized calcium, parathyroid hormone (PTH), and alkaline phosphatase.

RESULTS

FCM was the only consistent risk factor for incident hypophosphatemia (< 2.0 mg/dL; odds ratio vs FDI: 38.37; 95% CI: 16.62, 88.56; P < 0.001). Only FCM-treated patients developed severe hypophosphatemia (< 1.0 mg/dL; 11.3%; 13/115) or persistent hypophosphatemia (< 2.0 mg/dL at study end; 40.0%; 46/115). More severe hypophosphatemia associated with significantly greater increases in iFGF23, PTH, and alkaline phosphatase, and more severe decreases in 1,25(OH)2D and ionized calcium (all P < 0.05). Patients with persistent vs resolved hypophosphatemia demonstrated significantly greater changes in iFGF23, PTH, 1,25(OH)2D, and N-terminal procollagen-1 peptide levels (all P < 0.01), but alkaline phosphatase increased similarly in both groups.

CONCLUSION

Treatment with FCM was the only consistent risk factor for hypophosphatemia. Patients who developed severe or persistent hypophosphatemia after FCM treatment manifested more severe derangements in bone and mineral metabolism. Changes in bone biomarkers continued beyond resolution of hypophosphatemia, suggesting ongoing effects on bone that may help explain the association of FCM with osteomalacia and fractures.

Association of androgen excess and bone mineral density in women with classical congenital adrenal hyperplasia with 21-hydroxylase deficiency

The relationship between androgen excess and bone health in patients with congenital adrenal hyperplasia (CAH) with 21-hydroxylase (21-OH) deficiency is not fully understood. This study demonstrated positive correlations between androgen hormones and bone mineral density (BMD) in CAH women with 21-OH deficiency.

PURPOSE

This study aims to assess BMD and its association with androgen excess in women with CAH.

METHODS

We enrolled 92 women with CAH with 21-OH deficiency and retrospectively reviewed their clinical features, hormone concentrations, body composition, glucocorticoid (GC) dose, and BMD.

RESULTS

BMD was not different according to the subtypes of CAH. BMD at the lumbar spine was lower in women with CAH with regular menstruation than those with irregular menstruation (1.081 vs. 1.165 g/cm², P < 0.05). BMD was lower in women with CAH with 17-hydroxyprogesterone (17-OHP) < 10 ng/mL than in those with ≥ 10 ng/mL (lumbar spine, 1.019 vs. 1.150 g/cm²; femur neck, 0.806 vs. 0.899 g/cm²; total hip, 0.795 vs. 0.943 g/cm²; all P < 0.05). After adjusting for age and BMI in correlation analyses, testosterone concentrations were positively correlated with lumbar spine, femur neck, and total hip BMD (r = 0.46, r = 0.38, and r = 0.35, respectively; all P < 0.05), while 17-OHP was positively correlated with lumbar spine BMD (r = 0.38, P < 0.01). In subgroup analysis, 17-OHP was positively correlated with BMD (lumbar spine, r = 0.22; femur neck, r = 0.22; total hip, r = 0.24; all P < 0.05) only in the group with a total cumulative dose of GC ≥ 156.0 g/m².

CONCLUSION

Androgen excess may have a protective effect on BMD in women with classic CAH and high cumulative doses of GC.

Inflammation and Bone Metabolism in Rheumatoid Arthritis: Molecular Mechanisms of Joint Destruction and Pharmacological Treatments

Rheumatoid arthritis (RA) is an inflammatory disease characterized by a variety of symptoms and pathologies often presenting with polyarthritis. The primary symptom in the initial stage is joint swelling due to synovitis. With disease progression, cartilage and bone are affected to cause joint deformities. Advanced osteoarticular destruction and deformation can cause irreversible physical disabilities. Physical disabilities not only deteriorate patients' quality of life but also have substantial medical economic effects on society. Therefore, prevention of the progression of osteoarticular destruction and deformation is an important task. Recent studies have progressively improved our understanding of the molecular mechanism by which synovitis caused by immune disorders results in activation of osteoclasts; activated osteoclasts in turn cause bone destruction and para-articular osteoporosis. In this paper, we review the mechanisms of bone metabolism under physiological and RA conditions, and we describe the effects of therapeutic intervention against RA on bone.

Phoenix dactilyfera L. Pits Extract Restored Bone Homeostasis in Glucocorticoid-Induced Osteoporotic Animal Model through the Antioxidant Effect and Wnt5a Non-Canonical Signaling

Oxidative stress associated with long-term glucocorticoids administration is a route through which secondary osteoporosis can be developed. The therapeutic potential of Phoenix dactilyfera L. pits is offered by their balanced, valuable and diverse phytochemical composition providing protective potential against oxidative reactions, making it a good candidate to treat glucocorticoid-induced osteoporosis (GIO). This study evaluates the possible anti-osteoporotic effect of date pit extract (DPE) against dexamethasone (DEXA)-induced osteoporosis. Male rats were allocated into three control groups, which received saline, low and high doses of DPE (150 and 300 mg/kg/day), respectively. Osteoporosis-induced groups that received DEXA (1 mg/kg/day) were divided into DEXA only, DPE (2 doses) + DEXA, and ipriflavone + DEXA. Femoral bone minerals density and bone mineral content, bone oxidative stress markers, Wnt signaling, osteoblast and osteoclast differentiation markers, and femur histopathology were evaluated. DPE defeated the oxidative stress, resulting in ameliorative changes in Wnt signaling. DPE significantly reduced the adipogenicity and abolished the osteoclastogenic markers (RANKL/OPG ratio, ACP, TRAP) while enhancing the osteogenic differentiation markers (Runx2, Osx, COL1A1, OCN). In Conclusion DPE restored the balanced proliferation and differentiation of osteoclasts and osteoblasts precursors. DPE can be considered a promising remedy for GIO, especially at a low dose that had more potency.

The Role of Symptom Duration and Serologic Factors in the Relapse of IgG4-Related Ophthalmic Disease following Surgery: A Retrospective Cohort Study

IgG4-related disease (IgG4-RD) affects multiple organs and is characterized by immune-mediated inflammation and fibrosis; IgG-RD affecting orbital tissue is known as IgG4-related ophthalmic disease (IgG4-ROD). This research is aimed at exploring whether symptom duration and common serologic factors, such as IgG, IgE, and eosinophils, are potential risk factors for IgG4-ROD patient relapse after surgery and identifying possible causes of the positive correlation between symptom duration and relapse. This retrospective cohort study included 40 IgG4-ROD patients after surgery. Auxiliary inspection results were obtained before surgery and during follow-up, and relapse risk factors were identified based on previous studies. We used the Spearman rank correlation test to reveal the relationship between symptom duration and relapse time and identified the optimal cutoff value for symptom duration by X-tile. Then, we divided the patients into the long-duration and short-duration groups. Kaplan-Meier survival analyses and log-rank tests were performed to identify the relationship between symptom duration and relapse using X-tile software. Finally, we studied the relationship between previously studied relapse risk factors and symptom duration. The survival curves of the long-duration and short-duration groups were obviously different, and the baseline serum IgG, IgE, and eosinophil levels and asthma concomitant rate were significantly different between the long-duration and short-duration groups. Furthermore, the baseline serum IgG (r = 0.485, P = 0.002), IgE (r = 0.350, P = 0.037), and eosinophil (r = 0.6535, P < 0.0001) levels were positively correlated with symptom duration. Our study shows that IgG4-ROD symptom duration is significantly positively correlated with relapse rate and negatively correlated with relapse time. Symptom duration was positively correlated with serum baseline IgG4, IgE, and eosinophil levels and asthma history, which were potential risk factors for disease relapse. We recommended that IgG4-ROD patients with symptom durations greater than 96 months continue to receive maintenance steroid therapy longer than 1 year postsurgery to reduce the relapse rate.

Activation of dopamine receptor D1 promotes osteogenic differentiation and reduces glucocorticoid-induced bone loss by upregulating the ERK1/2 signaling pathway

Background

The inhibition of osteogenic differentiation is a major factor in glucocorticoid-induced bone loss, but there is currently no effective treatment. Dopamine, a major neurotransmitter, transmits signals via five different seven-transmembrane G protein-coupled receptors termed D1 to D5. Although the relevance of the neuroendocrine system in bone metabolism has emerged, the precise effects of dopamine receptor signaling on osteoblastogenesis remain unknown.

Methods

In vitro, western blotting and immunofluorescence staining were used to observe the expression of dopamine receptors in MC3T3-E1 and BMSCs cells treated with dexamethasone (Dex). In addition, Alizarin red S (ARS) and alkaline phosphatase (ALP) staining and western blotting were used to evaluate the effect of D1R activation on osteogenic differentiation in Dex-induced MC3T3-E1 cells via the ERK1/2 signaling pathway. In vivo, micro-CT and hematoxylin and eosin (H&E), toluidine blue and immunohistochemical staining were used to determine the effect of D1R activation on Dex-induced bone loss.

Results

We demonstrated that the trend in D1R but not D2-5R was consistent with that of osteogenic markers in the presence of Dex. We also demonstrated that the activation of D1R promoted Dex-induced osteogenic differentiation by activating the ERK1/2 pathway in vitro. We further demonstrated that a D1R agonist could reduce Dex-induced bone loss, while pretreatment with a D1R inhibitor blocked the effect of a D1R agonist in vivo.

Conclusions

Activation of D1R promotes osteogenic differentiation and reduces Dex-induced bone loss by activating the ERK1/2 pathway. Hence, D1R could serve as a potential therapeutic target for glucocorticoid-induced osteoporosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-022-00453-0.

Eucommia, Cuscuta, and Drynaria Extracts Ameliorate Glucocorticoid-Induced Osteoporosis by Inhibiting Osteoclastogenesis Through PI3K/Akt Pathway

Osteoporosis is one of the most common diseases in the world which resulted in heavy socioeconomic burden and a public health threat. Glucocorticoid-induced osteoporosis (GIO) is the most common secondary reason of osteoporosis. Therapeutic strategies using traditional Chinese medicine are under investigation for osteoporosis, with efforts to improve efficacy and clarify the mechanism. The combination of Eucommia, Cuscuta, and Drynaria is widely used in traditional Chinese decoction for osteoporosis treatment, but the experimental efficacy and mechanism are still unclear. Administration of E.C.D. extracts (Eucommia, Cuscuta, and Drynaria) in experimental GIO rats resulted in decreased urinal calcium, phosphorus loss, and decreased expression of RANKL, CTX in serum, increased serum calcium, phosphorus, and OPG level. E.C.D. extracts also improved bone density, structural integrity, and biomechanical function in experimental GIO rats. These finding were associated with E.C.D. extracts’ treatment efficacy to GIO in vivo. The balance between osteoclast and osteoblast activity is essential for bone remodeling and bone related disease. The E.C.D. extracts inhibited Raw 264.7 cell differentiation to osteoclast in vitro. On the other hand, it promoted OPG expression of bone marrow mesenchymal stromal cells (MSCs) which can suppress the osteoclast genesis. E.C.D. extracts also increased the Wnt1 and Runx2 expression which are related to osteoblast formation. It also regulated the paracrine effect of MSC to inhibit osteoclast differentiation. The analysis of HPLC and comprehensive pharmacology identified the constituents of E.C.D. extracts and the potential osteoporosis-related targets mediated by E.C.D. extracts. The KEGG enrichment analysis suggested that PI3K/Akt pathway may be involved in the regulation osteoclast genesis by E.C.D. extracts and the result of Western blot of vitro assays proved it. Collectively, these data demonstrate E.C.D. extracts can inhibit osteoclast differentiation to foster experimental osteoporosis both in vivo and in vitro and it may exert the function of inhibiting osteoclast differentiation through PI3K/Akt pathway.

Contemporary kidney transplantation has a limited impact on bone microarchitecture

Bone microarchitecture is an important component of bone quality and disturbances may reduce bone strength and resistance to trauma. Kidney transplant recipients have an excess risk of fractures, and bone loss affecting both trabecular and cortical bone compartments have been demonstrated after kidney transplantation. The primary aim of this study was to investigate the impact of kidney transplantation on trabecular and cortical bone microarchitecture, assessed by histomorphometry and micro computed tomography (μCT). Iliac crest bone biopsies, analyzed by bone histomorphometry and μCT, were performed at time of kidney transplantation and 12 months post-transplantation in an unselected cohort of 30 patients. Biochemical markers of mineral metabolism and bone turnover were measured at both time-points. At 12 months post-transplantation, bone turnover was low in 5 (17%) and normal in 25 (83%) patients. By histomorphometry, bone remodeling normalized, with decreases in eroded perimeters (4.0 to 2.1%, p = 0.02) and number of patients with marrow fibrosis (41 to 0%, p < 0.001). By μCT, trabecular thickness (134 to 125 μM, p = 0.003) decreased slightly. Other parameters of bone volume and microarchitecture, including cortical thickness (729 to 713 μm, p = 0.73) and porosity (10.2 to 9.5%, p = 0.15), remained stable. We conclude that kidney transplantation with current immunosuppressive protocols has a limited impact on bone microarchitecture.

•

Bone structure after kidney transplantation was explored using biopsy, μCT, and DXA.

•

Modest trabecular bone loss was detected in the first post-transplant year.

•

Cortical thickness and porosity were overall stable post-transplant.

•

Contemporary kidney transplantation has minimal impact on bone microarchitecture.

miR-29cb2 promotes angiogenesis and osteogenesis by inhibiting HIF-3α in bone

Coordination between osteogenesis and angiogenesis is required for bone homeostasis. Here, we show that miR-29cb2 is a bone-specific miRNA and plays critical roles on angiogenesis-osteogenesis coupling during bone remodeling. Mice with deletion of miR-29cb2 exhibit osteopenic phenotypes and osteoblast impairment, accompanied by pronounced decreases in specific H vessels. The decrease in bone miR-29cb2 was associated with pathological ovariectomy stimuli. Mechanistically, hypoxia-inducible factor (HIF)-3α, as a target for miR-29cb2, inhibits HIF-1α activity by competitively bonding with HIF-1β. Notably, miR-29cb2 in peripheral blood (PB) nearly is undetectable in sham and significantly increases in ovariectomy mice. Further evaluation from osteoporosis patients demonstrates similar signatures. ROC analysis shows miR-29cb2 in PB has higher sensitivity and specificity for diagnosing osteoporosis when compared with four clinical biomarkers. Collectively, these findings reveal that miR-29cb2 is essential for bone remodeling by inhibiting HIF-3α and elevated bone-specific miR-29cb2 in PB, which may be a promising biomarker for bone loss.

A randomised trial of alendronate as prophylaxis against loss in bone mineral density following lymphoma treatment

Oral alendronate is a safe and effective primary prophylaxis against loss in bone mineral density in lymphoma patients.

Lymphoma patients often receive high glucocorticoid doses as part of standard therapy. Observational studies have shown a substantial risk of glucocorticoid-induced osteoporosis (GIO) with associated fractures. The aim of the SIESTA trial was to determine if oral alendronate (ALN) is a safe and effective prophylaxis against GIO in lymphoma. SIESTA was a single-center, randomized, double-blinded, phase 2 study of lymphoma patients planned for glucocorticoid-containing chemotherapy. After randomization, patients received weekly ALN 70 mg or placebo for a total of 52 weeks. Bone mineral density (BMD) was assessed at baseline, after completion of chemotherapy (end of treatment [EOT]) (4 to 6 months), and at the end of the study (EOS) (12 months). Vertebral fracture and biomarkers were assessed at baseline and EOS. Patients with baseline BMD assessment and at least 1 follow-up BMD assessment were analyzed for efficacy. The primary endpoint was a change in lumbar spine T-score from baseline to EOS. Of the 59 patients enrolled, 23 of 30 in the ALN arm and 24 of 29 in the placebo arm were analyzed for efficacy. The mean change in T-score from baseline to 12 months at the lumbar spine was +0.15 for ALN and -0.12 for placebo (P = .023). The difference in ΔT_EOS between the ALN and placebo groups was larger among females (ALN 0.28; placebo -0.28; P = .01). Biomarker analyses confirmed reduced bone resorption in ALN-treated patients. In conclusion, ALN is a safe and effective primary prophylaxis against loss in BMD following glucocorticoid-containing chemotherapy. Despite reduced BMD loss in the ALN arm, the treatment did not influence fracture risk in this small cohort of patients.

Increased Prevalence of Fractures in Congenital Adrenal Hyperplasia: A Swedish Population-based National Cohort Study

CONTEXT

Low bone mineral density has been reported in individuals with congenital adrenal hyperplasia (CAH), but the prevalence of fractures is unclear.

OBJECTIVE

To study the prevalence of fractures in CAH.

DESIGN, SETTING, AND PARTICIPANTS

Patients with CAH (n = 714, all 21-hydroxylase deficiency) were compared with controls matched for sex and year and place of birth (n = 71 400). Data were derived by linking National Population-Based Registers.

MAIN OUTCOME MEASURES

Number and type of fractures.

RESULTS

Mean age was 29.8 ± 18.4 years. Individuals with CAH had more fractures compared to controls [23.5% vs 16.1%, odds ratio (OR) 1.61, 95% CI 1.35-1.91], and this was found in both sexes (females: 19.6% vs 13.3%, OR 1.57, 95% CI 1.23-2.02; males: 28.7% vs 19.6%, OR 1.65, 95% CI 1.29-2.12). Fractures were significantly increased in patients born before the introduction of neonatal screening but not in those born afterwards. Any major fracture associated with osteoporosis (spine, forearm, hip, or shoulder) was increased in all individuals with CAH (9.8% vs 7.5%, OR 1.34, 95% CI 1.05-1.72). The highest prevalence of fractures was seen in SV phenotype and I172N genotype while nonclassic phenotype and I2 splice genotype did not show increased prevalence. A transport accident as a car occupant and fall on the same level were more common in patients with CAH, both sexes, than in controls.

CONCLUSIONS

Patients with CAH had an increased prevalence of both any fracture and fractures associated with osteoporosis (both sexes) but not for patients neonatally screened. We conclude that fracture risk assessment and glucocorticoid optimization should be performed regularly.

Congenital Adrenal Hyperplasia-Current Insights in Pathophysiology, Diagnostics, and Management

Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders affecting cortisol biosynthesis. Reduced activity of an enzyme required for cortisol production leads to chronic overstimulation of the adrenal cortex and accumulation of precursors proximal to the blocked enzymatic step. The most common form of CAH is caused by steroid 21-hydroxylase deficiency due to mutations in CYP21A2. Since the last publication summarizing CAH in Endocrine Reviews in 2000, there have been numerous new developments. These include more detailed understanding of steroidogenic pathways, refinements in neonatal screening, improved diagnostic measurements utilizing chromatography and mass spectrometry coupled with steroid profiling, and improved genotyping methods. Clinical trials of alternative medications and modes of delivery have been recently completed or are under way. Genetic and cell-based treatments are being explored. A large body of data concerning long-term outcomes in patients affected by CAH, including psychosexual well-being, has been enhanced by the establishment of disease registries. This review provides the reader with current insights in CAH with special attention to these new developments.

Pathophysiology of Mild Hypercortisolism: From the Bench to the Bedside

Mild hypercortisolism is defined as biochemical evidence of abnormal cortisol secretion without the classical detectable manifestations of overt Cushing’s syndrome and, above all, lacking catabolic characteristics such as central muscle weakness, adipose tissue redistribution, skin fragility and unusual infections. Mild hypercortisolism is frequently discovered in patients with adrenal incidentalomas, with a prevalence ranging between 5 and 50%. This high variability is mainly due to the different criteria used for defining this condition. This subtle cortisol excess has also been described in patients with incidentally discovered pituitary tumors with an estimated prevalence of 5%. To date, the mechanisms responsible for the pathogenesis of mild hypercortisolism of pituitary origin are still not well clarified. At variance, recent advances have been made in understanding the genetic background of bilateral and unilateral adrenal adenomas causing mild hypercortisolism. Some recent data suggest that the clinical effects of glucocorticoid (GC) exposure on peripheral tissues are determined not only by the amount of the adrenal GC production but also by the peripheral GC metabolism and by the GC sensitivity. Indeed, in subjects with normal cortisol secretion, the combined estimate of cortisol secretion, cortisone-to-cortisol peripheral activation by the 11 beta-hydroxysteroid dehydrogenase enzyme and GC receptor sensitizing variants have been suggested to be associated with the presence of hypertension, diabetes and bone fragility, which are three well-known consequences of hypercortisolism. This review focuses on the pathophysiologic mechanism underlying both the different sources of mild hypercortisolism and their clinical consequences (bone fragility, arterial hypertension, subclinical atherosclerosis, cardiovascular remodeling, dyslipidemia, glucose metabolism impairment, visceral adiposity, infections, muscle damage, mood disorders and coagulation).

A network pharmacology approach to explore and validate the potential targets of ginsenoside on osteoporosis

Background: Osteoporosis (OP) is determined as a chronic systemic bone disorder to increase the susceptibility to fracture. Ginsenosides have been found the anti-osteoporotic activity of in vivo and in vitro. However, its mechanism remains unknown.Methods: The potential mechanism of ginsenosides in anti-osteoporotic activity was identified by using network phamacology analysis. The active compounds of ginsenosides and their targets associated to OP were retrieved from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform, Drug Bank, Pharmmapper, and Cytoscape. The Gene ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis target genes were performed in String, Phenopedia, DisGeNET database, and Metascape software. The protein to protein interaction were created by String database and Cytoscape software. The molecular docking was used to investigate the interactions between active coumpounds and potential targets by utilizing SwissDock tool, UCSF Chimera, and Pymol software. Results: A total of eight important active ingredients and 17 potential targets related to OP treatment were subjected to analyze. GO analysis showed the anti-osteoporosis targets of ginsenoside mainly play a role in the response to steroid hormone. KEGG enrichment analysis indicated that ginsenoside treats OP by osteoblast differentiation signal pathway. Lastly, the molecular docking outcomes indicated that ginsenoside rh2 had a good binding ability with four target proteins IL1B, TNF, IFNG, and NFKBIA. Conclusion: IL1B, TNF, IFNG, and NFKBIA are the most important targets and osteoblast differentiation is the most valuable signaling pathways in ginsenoside for the treatment of OP, which might be beneficial to elucidate the mechanism concerned to the action of ginsenoside and might supply a better understanding of its anti-OP effects.

Prevalence and risk factors of osteoporosis in saudi end-stage renal disease patients on hemodialysis

Background:

Objective:

Methods:

Results:

Conclusion:

Total Flavonoids of Drynariae Rhizoma Improve Glucocorticoid-Induced Osteoporosis of Rats: UHPLC-MS-Based Qualitative Analysis, Network Pharmacology Strategy and Pharmacodynamic Validation

BACKGROUND

Glucocorticoid-induced osteoporosis (GIOP) is a common form of secondary osteoporosis caused by the protracted or a large dosage of glucocorticoids (GCs). Total flavonoids of Drynariae rhizoma (TFDR) have been widely used in treating postmenopausal osteoporosis (POP). However, their therapeutic effects and potential mechanism against GIOP have not been fully elucidated.

METHODS

Ultra-high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC-ESIQ-TOF-MS) experiments were performed for qualitative analysis. We performed hematoxylin-eosin (HE) staining and microcomputed tomography (micro-CT) analysis to detect the changes in bone microstructure. The changes in biochemical parameters in the serum samples were determined by performing an enzyme-linked immunosorbent assay (ELISA). The prediction results of network pharmacology were verified via quantitative real-time polymerase chain reaction (qRT-PCR) to elucidate the potential mechanism of TFDR against GIOP.

RESULTS

A total of 191 ingredients were identified in vitro and 48 ingredients in vivo. In the in-vivo experiment, the levels of the serum total cholesterol (TC), the serum triglyceride (TG), Leptin (LEP), osteocalcin (OC), osteoprotegerin (OPG), bone morphogenetic protein-2 (BMP-2), propeptide of type I procollagen (PINP), tartrate-resistant acid phosphatase (TRACP) and type-I collagen carboxy-terminal peptide (CTX-1) in the TFDR group significantly changed compared with those in the GIOP group. Moreover, the TFDR group showed an improvement in bone mineral density and bone microstructure. Based on the results of network pharmacology analysis, 67 core targets were selected to construct the network and perform PPI analysis as well as biological enrichment analysis. Five of the targets with high "degree value" had differential gene expression between groups using qRT-PCR.

CONCLUSION

TFDR, which may play a crucial role between adipose metabolism and bone metabolism, may be a novel remedy for the prevention and clinical treatment of GIOP.

Modified Qing' e Pills exerts anti-osteoporosis effects and prevents bone loss by enhancing type H blood vessel formation

OBJECTIVE

To explore whether the modified Qing' e Pills (MQEP) exerts anti-osteoporotic effects and prevents bone loss by enhancing angiogenesis.

METHODS

Network pharmacology was used to assess whether MQEP has a pro-angiogenic capacity and to predict its potential targets. Human umbilical vein endothelial cells were treated with glucocorticoids and MQEP to assess cell viability. The expression of angiotensin II type 1 receptor, angiotensin II type 2 receptor, and angiotensin converting enzyme, which are associated with the activation of the renin-angiotensin-aldosterone system, and the expression of vascular endothelial growth factor and hypoxia-inducible factor 1 alpha, which are associated with the formation of type H blood vessels, were examined by western blot and RT-qPCR. Thereafter, the glucocorticoid-induced osteoporosis model was established and intervened with MQEP. Femur scanning was performed with micro-computed tomography; trabecular spacing, trabecular thickness, and trabecular number were observed and calculated; the expression of nuclear factor-kappa B ligand and osteoprotegerin was detected by ELISA, and the ratio was calculated to evaluate the degree of bone resorption. Finally, type H blood vessels that were highly coupled to osteogenic cells were identified by immunohistochemistry staining and flow cytometry.

RESULTS

This is the first study to reveal and confirm that MQEP could prevent bone loss in glucocorticoid-induced osteoporosis by promoting the expression of hypoxia-inducible factor 1 alpha and vascular endothelial growth factor, which are highly associated with type H blood vessel formation. In vitro experiments confirmed that MQEP could effectively promote the proliferation of vascular endothelial cells and alleviate glucocorticoids-induced activation of the renin-angiotensin-aldosterone system, thereby reducing vascular injury.

CONCLUSION

MQEP exerts anti-osteoporosis effects and prevents bone loss by alleviating vascular injury caused by renin-angiotensin-aldosterone system activation and promoting type H blood vessel formation.

Focusing on OB-OC-MΦ Axis and miR-23a to Explore the Pathogenesis and Treatment Strategy of Osteoporosis

Osteoporosis is a bone metabolic disorder characterized by decreased bone density and deteriorated microstructure, which increases the risk of fractures. The imbalance between bone formation and bone resorption results in the occurrence and progression of osteoporosis. Osteoblast-mediated bone formation, osteoclast-mediated bone resorption and macrophage-regulated inflammatory response play a central role in the process of bone remodeling, which together maintain the balance of the osteoblast-osteoclast-macrophage (OB-OC-MΦ) axis under physiological conditions. Bone formation and bone resorption disorders caused by the imbalance of OB-OC-MΦ axis contribute to osteoporosis. Many microRNAs are involved in the regulation of OB-OC-MΦ axis homeostasis, with microRNA-23a (miR-23a) being particularly crucial. MiR-23a is highly expressed in the pathological process of osteoporosis, which eventually leads to the occurrence and further progression of osteoporosis by inhibiting osteogenesis, promoting bone resorption and inflammatory polarization of macrophages. This review focuses on the role and mechanism of miR-23a in regulating the OB-OC-MΦ axis to provide new clinical strategies for the prevention and treatment of osteoporosis.

Case report: Clinical characteristics and treatment of secondary osteoporosis induced by X-linked congenital adrenal dysplasia

OBJECTIVE

To summarize the clinical features and bone complications in a patient from a large family with X-linked congenital adrenocortical hypoplasia (AHC) and evaluate the efficacy of different treatment regimens on the prognosis of secondary osteoporosis caused by AHC at a 5-year follow-up.

METHODS

A large family with AHC was recruited, and the causative gene mutation was identified by Sanger sequencing in the proband. Clinical features as well as radiological examinations and laboratory indices of osteoporosis secondary to AHC were analyzed in this study. Meanwhile, the proband was treated with classical antiresorptive drugs (bisphosphonates) for 2 years and switched to a vitamin K₂ analogue for another 3 years, during which the efficacy of the drugs was evaluated.

RESULTS

The proband was identified as carrying a homozygous insertion mutation (p. Thr193GlyfsX13) in the NR0B1 (nuclear receptor subfamily 0, group B, member 1) gene, resulting in a premature stop codon due to a frameshift mutation. During treatment and follow-up, the proband did not respond well to bisphosphonate and developed atypical femoral fractures. Vitamin K₂ improved clinical symptoms. In terms of bone mineral density (BMD), there is no evidence of any effect of vitamin K₂ on the neck of femur, though some minor effects on spinal BMD cannot be excluded.

CONCLUSIONS

Secondary osteoporosis induced by AHC deserves clinical attention. Unlike in primary osteoporosis, the curative effect of bisphosphonates was unsatisfactory and was more likely to cause atypical femoral fractures in long-term treatment. It is suggested that bone anabolic drugs may be better alternatives.

Comprehensive analysis of the m6A-related molecular patterns and diagnostic biomarkers in osteoporosis

BACKGROUND

N6-methyladenosine (m6A) modification is a critical epigenetic modification in eukaryotes and involves several biological processes and occurrences of diseases. However, the roles and regulatory mechanisms of m6A regulators in osteoporosis (OP) remain unclear. Thus, the purpose of this study is to explore the roles and mechanisms of m6A regulators in OP.

METHODS

The mRNA and microRNA (miRNA) expression profiles were respectively obtained from GSE56815, GSE7158, and GSE93883 datasets in Gene Expression Omnibus (GEO). The differential expression of 21 m6A regulators between high-bone mineral density (BMD) and low-BMD women was identified. Then, a consensus clustering of low-BMD women was performed based on differentially expressed (DE)-m6A regulators. The m6A-related differentially expressed genes (DEGs), the differentially expressed miRNAs (DE-miRNAs), and biological functions were investigated. Moreover, a weighted gene co-expression network analysis (WGCNA) was constructed to identify the OP-related hub modules, hub genes, and the functional pathways. Then, an m6A regulator-target-pathway network and the competing endogenous RNA (ceRNA) network in key modules were constructed. A least absolute shrinkage and selection operation (LASSO) Cox regression model and a Support Vector Machine-Recursive Feature Elimination (SVM-RFE) model were constructed to identify the candidate genes for OP prediction. The receiver operator characteristic (ROC) curves were used to validate the performances of predictive models and candidate genes.

RESULTS

A total of 10,520 DEGs, 13 DE-m6A regulators, and 506 DE-miRNAs between high-BMD and low-BMD women were identified. Two m6A-related subclusters with 13 DE-m6A regulators were classified for OP. There were 5,260 m6A-related DEGs identified between two m6A-related subclusters, the PI3K-Akt, MAPK, and immune-related pathways, and bone metabolism was mainly enriched in cluster 2. Cell cycle-related pathways, RNA methylation, and cell death-related pathways were significantly involved in cluster 1. Five modules were identified as key modules based on WGCNA, and an m6A regulator-target gene-pathway network and the ceRNA network were constructed in module brown. Moreover, three m6A regulators (FTO, YTHDF2, and CBLL1) were selected as the candidate genes for OP.

CONCLUSION

M6A regulators play an important role in the occurrences and diagnosis of OP.

Bushen huoxue decoction inhibits RANKL-stimulated osteoclastogenesis and glucocorticoid-induced bone loss by modulating the NF-κB, ERK, and JNK signaling pathways

Glucocorticoid-induced osteoporosis (GIOP) is the most common form of secondary osteoporosis, which is caused by a disorder in bone metabolism due to excessive activation of osteoclasts. Bushen Huoxue decoction (BHD) is an herbal formula with multiple pharmacological effects, including anti-inflammatory, antioxidant activity and stem cell migration promotion. However, the effect of BHD on osteoclastogenesis has not been reported. In this study, we aimed to elucidate the effect of BHD on RANKL-stimulated osteoclastogenesis and explored its underlying mechanisms of action in vitro. Our results show that BHD had no effect on BMMs and RAW264.7 cells viability, but inhibited RANKL-induced osteoclast formation in vitro. Furthermore, BHD attenuated RANKL-induced NF-κB, ERK, and JNK signaling. The attenuation of NF-κB, ERK, and JNK activation were enough to impede downstream expression of c-fos and NFATc1 and related specific genes. Meanwhile, we investigated the therapeutic effect of BHD on glucocorticoid-induced osteoporosis (GIOP) mice. The result indicated that BHD prevents glucocorticoid-induced osteoporosis and preserves bone volume by repressing osteoclast activity. Collectively, BHD shows significant osteoclast inhibition and holds great promise in the treatment of osteoporosis.

The risk factors for developing clustered vertebral compression fractures: a single center study

OBJECTIVE

Vertebral compression fractures (VCFs) are common among elderly individuals, but clustered VCFs (C-VCFs) are rare and more severe. The risk factors for C-VCFs remain unclear. Thus, we investigated the clinical characteristics of C-VCFs to identify the imminent fracture risk and to improve the treatment for such patients.

METHODS

We reviewed records of VCF patients at a single medical center between January 2011 and September 2020. Patients who had four or more VCFs within one year were categorized into the C-VCF group, and the remaining patients were paired into the control group at a ratio of 2:1. We collected demographic, clinical, laboratory, and radiological information regarding these patients. Univariate analyses, stratified analyses, and multivariate logistic regression were performed to identify the risk factors for C-VCFs.

RESULTS

A total of 156 patients were enrolled, of whom 52 were C-VCF patients. C-VCF patients had more severe fractures and pain, with fractures occurring at uncommon sites of the spine. The independent risk factors for C-VCFs included glucocorticoid treatment (P<0.001, HR: 12.7), recent fracture history (P=0.021, HR: 5.5), and lower trabecular bone score (TBS, P=0.044, HR: 1.6). TBS and bone mineral density had greater predictive values in patients without glucocorticoid treatment (P<0.001). Sex, age, and bone turnover biomarkers were not independent risk factors for C-VCFs.

CONCLUSION

C-VCFs are rare adverse consequences of severe osteoporosis, for which glucocorticoid treatment, recent fracture history, and lower TBS are unique risk factors that are valuable for the early identification and prevention of C-VCFs.

Endocrinology of bone mineralization: an update

Throughout the world, millions of people suffer from fragilizing osteopathies such as osteomalacia and osteoporosis.Osteomalacia is a rare disorder, corresponding to mineralization abnormalities in adult bone, as opposed to rickets in children. Renal phosphate loss and hypophosphatasia are the main causes of vitamin-resistant osteomalacia. Diagnosis is based on clinical history, phosphocalcic metabolism assessment and, if necessary, molecular characterization, and must be rapid in order to initiate the most appropriate treatment and consider new treatments such as burosumab if necessary.Osteoporosis is characterized by reduced bone mass and strength, which increases the risk of fragility fracture. Fracture-related burden is expected to increase over the coming decades linked to the aging of population and a treatment gap. In order to reduce this treatment gap, it is important to develop two strategies: improvement of screening and of treatment. Systematic screening using the FRAX® fracture risk assessment tool could be useful to increase anti-osteoporosis medical treatment and reduce fracture rates. The question of treatment sequencing in osteoporosis is another challenge, notably after denosumab cessation, complicated by a decrease in bone mineral density and increased risk of fracture. New treatments are also available, including romosozumab, a humanized monoclonal antibody which promotes bone formation and inhibits bone resorption by inhibiting sclerostin. Romosozumab is approved in several countries, including France, for treating severe osteoporosis in postmenopausal women at high risk of fracture and free of cardiovascular comorbidity.Endocrinologists need to be aware of these fragilizing osteopathies in order to improve both diagnosis and treatment.

A novel biomimetic nanomedicine system with anti-inflammatory and anti-osteoporosis effects improves the therapy efficacy of steroid-resistant nephrotic syndrome

Clinically, steroid-resistant nephrotic syndrome (SRNS) is always prolonged and difficult to treat and easily develops into end-stage renal disease, resulting in a low survival rate. Strategies to reverse steroid resistance and reduce the long-term use of high doses of steroid medicines are urgently needed. In this study, a novel nanoparticle drug system (Pm-GCH) with a core–shell structure was designed. Metal–organic frameworks, synthesized by glycyrrhizic acid (G) and calcium ions (Ca²⁺) loaded with hydrocortisone (H) were the core of the nanoparticles. Platelet membrane vesicles were the shells. The natural platelet membrane endows Pm-GCH with good biocompatibility and the ability to promote immune escape. In addition, under the chemotaxis of inflammatory factors, platelet membranes assist Pm-GCH in nonspecific targeting of the inflammatory sites of the kidney. Under an inflammatory acid environment, GCH slowly degrades and releases glycyrrhizic acid and hydrocortisone. Glycyrrhizic acid inhibits the inactivation of hydrocortisone, jointly inhibits the activity of phospholipase A2 (PLA2) and the classic activation pathway of complement C2, blocks the production of inflammatory factors, plays an anti-inflammatory role, and enhances the efficacy of hydrocortisone in the treatment of SRNS. Moreover, glycyrrhizic acid alleviates osteoporosis induced by long-term use of glucocorticoids. These results indicate that Pm-GCH is a promising treatment strategy for SRNS.

DANCR Mediates the Rescuing Effects of Sesamin on Postmenopausal Osteoporosis Treatment via Orchestrating Osteogenesis and Osteoclastogenesis

As one of the leading causes of bone fracture in postmenopausal women and in older men, osteoporosis worldwide is attracting more attention in recent decades. Osteoporosis is a common disease mainly resulting from an imbalance of bone formation and bone resorption. Pharmaceutically active compounds that both activate osteogenesis, while repressing osteoclastogenesis hold the potential of being therapeutic medications for osteoporosis treatment. In the present study, sesamin, a bioactive ingredient derived from the seed of Sesamum Indicum, was screened out from a bioactive compound library and shown to exhibit dual-regulating functions on these two processes. Sesamin was demonstrated to promote osteogenesis by upregulating Wnt/β-catenin, while repressing osteoclastogenesis via downregulating NF-κB signaling . Furthermore, DANCR was found to be the key regulator in sesamin-mediated bone formation and resorption . In an ovariectomy (OVX)-induced osteoporotic mouse model, sesamin could rescue OVX-induced bone loss and impairment. The increased serum level of DANCR caused by OVX was also downregulated upon sesamin treatment. In conclusion, our results demonstrate that sesamin plays a dual-functional role in both osteogenesis activation and osteoclastogenesis de-activation in a DANCR-dependent manner, suggesting that it may be a possible medication candidate for osteoporotic patients with elevated DNACR expression levels.

Challenges and Opportunities for Osteoporosis Care During the COVID-19 Pandemic

PURPOSE

The coronavirus disease 2019 (COVID-19) has both directly and indirectly affected osteoporosis diagnosis and treatment throughout the world.

METHODS

This mini-review summarizes the available evidence regarding the effects of COVID-19, its treatment, and the consequences of the pandemic itself on bone health. Additionally, we review evidence and expert recommendations regarding putative effects of osteoporosis medications on COVID-19 outcomes and vaccine efficacy and summarize recommendations for continuation of osteoporosis treatment during the pandemic.

RESULTS

The use of standard screening procedures to assess for osteoporosis and fracture risk declined dramatically early in the pandemic, while rates of fragility fractures were largely unchanged. COVID-19, its treatments, and public health measures to prevent viral spread are each likely to negatively affect bone health. Osteoporosis treatments are not known to increase risk of adverse events from COVID-19, and preclinical data suggest possible beneficial effects of some therapies. Vitamin D deficiency is clearly associated with adverse outcomes from COVID-19, but it remains unclear whether vitamin D supplementation may improve outcomes. Osteoporosis treatment should be continued whenever possible, and recommendations for substituting therapies, if required, are available.

CONCLUSION

The COVID-19 pandemic has decreased screening and disrupted treatment for osteoporosis. Osteoporosis medications are safe and effective during the pandemic and should be continued whenever possible. Further studies are needed to fully understand the impact of the COVID-19 pandemic on long-term bone health.

Naringin Improves Osteoblast Mineralization and Bone Healing and Strength through Regulating Estrogen Receptor Alpha-Dependent Alkaline Phosphatase Gene Expression

Phytoestrogens are strongly recommended for treating osteoporosis. Our previous study showed that naringin, a citrus flavonoid, can enhance the bone mass in ovariectomized rats. In this study, we further elucidated the mechanisms of naringin-induced osteoblast maturation and bone healing. Treatment of human osteoblasts with naringin increased cell viability and proliferation. In parallel, exposure to naringin enhanced translocation of estrogen receptor alpha (ERα) to nuclei and its transactivation activity. Sequentially, naringin induced alkaline phosphatase (ALP) mRNA and protein expression and its enzyme activity. Pretreatment with methylpiperidinopyrazole (MPP), a specific inhibitor of ERα, attenuated naringin-induced augmentations in ERα transactivation activity, ALP gene expression, and cell mineralization. The beneficial effects of naringin were also confirmed in mouse MC3T3-E1 cells. Moreover, administration of mice with a bone defect with naringin increased levels of ERα and ALP in damaged sites and simultaneously enhanced the healing rate and bone strength. Nevertheless, treatment with MPP weakened naringin-triggered expression of ERα and ALP and improved bone healing and mass. Therefore, naringin could improve osteoblast mineralization and bone healing via regulating ERα-dependent ALP gene expression. Naringin can be clinically applied for treatment of osteoporosis-related bone diseases.

Epidemiology of glucocorticoid-induced osteoporosis and management of associated fracture risk in Japan

INTRODUCTION

Glucocorticoid-induced osteoporosis (GIOP) is associated with a high fracture risk. Practice guidelines by the Japanese Society for Bone and Mineral Research in 2014 recommend bone densitometry and appropriate treatment to reduce this risk. The study objectives were to describe characteristics of GIOP patients in Japan and to evaluate their management in a subgroup of patients without comorbid cancer.

MATERIALS AND METHODS

This retrospective cohort study was performed using the Medical Data Vision (MDV) database from Japan. Adult patients initiating oral glucocorticoid treatment with a total GIOP risk score ≥ 3, based on the 2014 practice guideline, identified between 2009 and 2019 were eligible. A subgroup of patients without any cancer diagnosis was also identified. Data were extracted on demographics, concurrent medical conditions, use of bone densitometry, and osteoporosis treatment.

RESULTS

25,569 patients were eligible, of whom 12,227 had a confirmed cancer diagnosis. Mean age was 68.5 years and 12,356 patients (48.3%) were women. Concurrent medical conditions of interest were documented in 14,887 patients, most frequently rheumatoid arthritis (n = 4185) and asthma (n = 3085). Yearly bone densitometry was performed in 6.5% (n = 865) of the cancer-free subgroup; 51.8% (n = 6905) were prescribed an osteoporosis treatment, most frequently bisphosphonates (n = 5132; 74.3%). Between 2011 and 2018, rates of densitometry were stable, whereas prescription rates increased from 40.0 to 51.8%.

CONCLUSION

In spite of publication of guidelines for GIOP management, there is an important treatment gap in their application in everyday practice. For this reason, public health measures to increase physician awareness of GIOP are needed.

Effect of Intermittent Fasting on Glucose Homeostasis and Bone Remodeling in Glucocorticoid-Induced Osteoporosis Rat Model

BACKGROUND

The present study examined the effect of intermittent fasting (IF) on bone mineral content (BMC) and bone mineral density (BMD) and the markers of bone remodeling in a glucocorticoid-induced osteoporosis (GIO) rat model.

METHODS

Forty male rats were allocated to 4 groups (N=10 per group): control group of normal rats; control+IF group (normal rats subjected to IF for 16-18 hr daily for 90 days); dexamethasone (DEX) group: (DEX [0.5 mg i.p.] for 90 days); and DEX+IF group (DEX and IF for 90 days). By the end of the experiment, BMD and BMC in the right tibia were measured. Serum levels of the following were measured: glucose; insulin; triglycerides (TGs); total cholesterol; parathyroid hormone (PTH); osteoprotegerin (OPG); receptor activator of nuclear factor-κB (RANK); bone-resorbing cytokines, including bone deoxypyridinoline (DPD), N-terminal telopeptide of collagen type I (NTX-1), and tartrate-resistant acid phosphatase 5b (TRAP-5b); and bone-forming cytokines, including alkaline phosphatase (ALP) and osteocalcin (OC).

RESULTS

DEX administration for 90 days resulted in significantly increased serum levels of glucose, insulin, TGs, cholesterol, PTH, OPG, DPD, NTX-1, and TRAP-5b and significantly decreased BMD, BMC, and serum levels of RANK, OC, and ALP (all P<0.05). IF for 90 days significantly improved all these parameters (all P<0.05).

CONCLUSIONS

IF corrected GIO in rats by inhibiting osteoclastogenesis and PTH secretion and stimulating osteoblast activity.

Acacetin inhibits RANKL-induced osteoclastogenesis and LPS-induced bone loss by modulating NFATc1 transcription

Osteolytic disorders are characterized by impaired bone volume and trabecular structure that leads to severe fragility fractures. Studies have shown that excessive osteoclast activity causes impaired bone microstructure, a sign of osteolytic diseases such as osteoporosis. Approaches of inhibiting osteoclastogenesis and bone resorption specifically could prevent osteoporosis and other osteolytic disorders. Acacetin is a potent molecule extracted from plants with anti-cancer and anti-inflammatory bioactivities. Here, we demonstrated, for the first time, that acacetin repressed osteoclastogenesis, formation of F-actin rings, bone resorption activity, and osteoclast-related gene expression in vitro through modulating ERK, P38, and NF-κB signaling pathways and preventing expression of NFATc1. Micro-CT and H & E staining results indicated that acacetin alleviated LPS-induced osteolysis in vivo. Overall, our findings suggested that acacetin could help to prevent osteoporosis and other osteoclast-related osteolytic disorders.

Up-regulation of SIRT1 induced by 17beta-estradiol promotes autophagy and inhibits apoptosis in osteoblasts

Osteoporosis is a common systemic skeletal metabolism disorder resulting in bone fragility and increased fracture risk. Silent information regulator factor 2 homolog 1 (SIRT1) is crucial in the regulation of several biological processes, including bone metabolism, autophagy, apoptosis, and aging. This study aimed to assess whether the up-regulation of SIRT1 induced by 17beta-estradiol (17β-E2) could promote autophagy and inhibit apoptosis in osteoblasts via the AMPK-mTOR and FOXO3a pathways, respectively. The study found that 17β-E2 (10^-6 M) administration induced the up-regulation of SIRT1 in osteoblasts. Up-regulation of SIRT1 induced by 17β-E2 increased the expression level of LC3, Beclin-1, Bcl-2, p-AMPK, FOXO3a but decreased caspase-3 and p-mTOR expression, and then promoted autophagy and inhibited apoptosis. More autophagosomes were observed under a transmission electron microscope (TEM) in 17β-E2 and SRT1720 (a selective SIRT1 activator) co-treated group. When Ex527 (a SIRT1-specific inhibitor) was pretreated, the reversed changes were observed. Taken together, our findings demonstrated that the up-regulation of SIRT1 induced by 17β-E2 could promote autophagy via the AMPK-mTOR pathway and inhibit apoptosis via the FOXO3a activation in osteoblasts, and SIRT1 might become a more significant target in osteoporosis treatment.