Glucocorticoid-induced Osteoporosis Research Articles

An integrated fecal metabolomic based on 1 H-NMR and UPLC-QTOF-MS revealed the preventive mechanism of Gushudan on glucocorticoid-induced osteoporotic rats.

Gushudan (GSD) has the effect of strengthening bones and nourishing kidneys. However, its specific intervention mechanism still remains unclear. In this study, to investigate the pathogenesis of glucocorticoid-induced osteoporosis (GIOP) and the preventive mechanism of GSD on GIOP, fecal metabolomics based on 1 H-NMR and ultra-high-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry method was established. The changes in endogenous metabolites and the relevant metabolic pathways in the control group, model group, and GSD treatment group were investigated via multivariate statistical analysis. As a result, a total of 39 differential metabolites were identified. Of these, 22 metabolites, such as L-methionine, guanine, and sphingosine, were newly discovered as differential metabolites of GIOP. Amino acid metabolism, energy metabolism, intestinal flora metabolism, and lipid metabolism were significantly changed in the fecal profiles of GIOP rats, and GSD could play an anti-osteoporosis role by regulating these metabolic pathways. Finally, compared with our previous study of the GSD to prevent kidney yang deficiency syndrome, this study suggested that there were some identical differential metabolites and metabolic pathways. It showed that there was some correlation among the metabolic profiles of the intestine, kidney, and bone in GIOP rats. Therefore, this study offered new insights into the in-depth understanding of the pathogenesis of GIOP and the intervention mechanism of GSD.

Risk and management of osteoporosis due to inhaled, epidural, intra-articular or topical glucocorticoids

Glucocorticoids (GCs) are widely used by several specialties for the treatment of a variety of diseases and conditions. The unfavorable effect of oral GCs on bone health is well-documented. The ensuing from their use glucocorticoid-induced osteoporosis (GIOP) is the most common cause of medication-induced osteoporosis and fractures. It is uncertain, however, if, and in what extent, GCs administered by other routes affect the skeleton. In the present review, we quote current evidence on the effect of inhaled GCs, epidural and intra-articular steroid injections, and topical GCs on bone outcomes. Although evidence is limited and weak, it seems that a small proportion of the administered GCs may be absorbed, enter the systemic circulation, and adversely affect the skeleton. Potent GCs, higher doses, and longer treatment duration seem to infer the greater risk for bone loss and fractures. There are scarce data, and only for inhaled GCs, regarding the efficacy of antiosteoporotic medications in patients receiving GCs through routes other than oral. Further studies are needed to clarify the relationship between GC administration through these routes and bone outcomes and to help establishing guidelines for the optimal management of such patients.

RNA-binding Protein QKI Inhibits Osteogenic Differentiation Via Suppressing Wnt Pathway

Dysregulation of MSCs differentiation is associated with many pathophysiological processes. Genetically modified MSCs transplantation helps restore bone loss efficiently. BMSCs-specific QKI overexpressing and knockdown mice were built to explore QKI's role in bone formation and fat accumulation. Primary BMSCs with QKI overexpression and knockout were subjected to osteogenic and adipogenic differentiation. ALP staining and oil red O staining were performed to evaluate the differences between the groups. RNA immunoprecipitation was performed to identify the QKI-related pathway. QKI deficient BMSCs were transplanted into mice with glucocorticoid-induced osteoporosis to evaluate its therapeutic potential. Mice harboring BMSC-specific transgenic QKI exhibited reduced bone mass, while BMSC-specific QKI-deficient mice showed an increase in bone mass. Osteogenic differentiation of QKI deficient BMSCs was promoted and adipogenic differentiation was inhibited, while QKI overexpression in BMSCs displayed the opposite effects. To define the underlying mechanisms, RIP sequencing was performed. Wnt pathway-related genes were the putative direct target mRNAs of QKI, Canonical Wnt pathway activation was involved in QKI's effects on osteogenic differentiation. RNA immunoprecipitation quantitative real-time Polymerase Chain Reaction (PCR) and RNA fluorescence in situ hybridization experiments further validated that QKI repressed the expressions of Wnt5b, Fzd7, Dvl3 and β-catenin via direct binding to their putative mRNA specific sites. Glucocorticoid-induced osteoporotic mice transplanted with QKI deficient BMSCs exhibited less bone loss compared with mice transplanted with control BMSCs. QKI suppressed BMSCs osteogenic differentiation by downregulating the expressions of Wnt5b, Fzd7, Dvl3 and β-catenin. Loss of QKI in BMSCs transplantation may provide a new strategy for the treatment of orthopedic diseases such as osteoporosis.

Galangin mitigates glucocorticoid-induced osteoporosis by activating autophagy of BMSCs via triggering the PKA/CREB signaling pathway.

Glucocorticoid-induced osteoporosis (GIOP), one of the most common and serious adverse effects associated with glucocorticoid administration, manifests as decreased bone formation and increased bone resorption, eventually culminating in bone loss. Galangin (GAL) is a flavonoid extracted from the medicinal herbal galangal that possesses a variety of pharmacological activities and can inhibit osteoclastogenesis. However, the effects of GAL on GIOP remain unclear. Our study aims to explore the effects of GAL on GIOP in mice and the underlying mechanism. Our results show that GAL markedly mitigates the severity of dexamethasone (Dex)-induced osteoporosis in mice and potentiates osteogenic differentiation in mouse bone marrow-derived mesenchymal stem cells (BMSCs). Furthermore, GAL also significantly counteracts Dex-mediated suppression of osteogenic differentiation and autophagy in human BMSCs. GAL augments PKA/CREB-mediated autophagic flux in BMSCs and the bones of osteoporotic mice. GAL-mediated osteogenic differentiation in Dex-treated BMSCs is significantly decreased by the PKA inhibitor H89 and autophagy inhibitor 3-methyladenine. Collectively, our data indicate that GAL can ameliorate GIOP, partly by augmenting the mineralization of BMSCs by potentiating PKA/CREB-mediated autophagic flux, highlighting its potential therapeutic use in treating glucocorticoid-related osteoporosis.

Clinical efficacy of denosumab, teriparatide, and oral bisphosphonates in the prevention of glucocorticoid-induced osteoporosis: a systematic review and meta-analysis

BackgroundContinuous use of glucocorticoids (GCs) has become the primary cause of secondary osteoporosis. Bisphosphonate drugs were given priority over denosumab and teriparatide in the 2017 American College of Rheumatology (ACR) guidelines but have a series of shortcomings. This study aims to explore the efficacy and safety of teriparatide and denosumab compared with those of oral bisphosphonate drugs.MethodsWe systematically searched studies included in the PubMed, Web of Science, Embase, and Cochrane library databases and included randomized controlled trials that compared denosumab or teriparatide with oral bisphosphonates. Risk estimates were pooled using both fixed and random effects models.ResultsWe included 10 studies involving 2923 patients who received GCs for meta-analysis, including two drug base analyses and four sensitivity analyses. Teriparatide and denosumab were superior to bisphosphonates in increasing the bone mineral density (BMD) of the lumbar vertebrae [teriparatide: mean difference [MD] 3.98%, 95% confidence interval [CI] 3.61–4.175%, P = 0.00001; denosumab: MD 2.07%, 95% CI 0.97–3.17%, P = 0.0002]. Teriparatide was superior to bisphosphonates in preventing vertebral fractures and increasing hip BMD [MD 2.39%, 95% CI 1.47–3.32, P < 0.00001]. There was no statistically significant difference between serious adverse events, adverse events, and nonvertebral fracture prevention drugs.ConclusionsTeriparatide and denosumab exhibited similar or even superior characteristics to bisphosphonates in our study, and we believe that they have the potential to become first-line GC-induced osteoporosis treatments, especially for patients who have previously received other anti-osteoporotic drugs with poor efficacy.

Impact of exercise-induced irisin on bones of osteoporotic male rat model

This study aimed to evaluate the impact of exercise-induced irisin on bone mineral density (BMD), bone turnover and bone microarchitecture in normal and glucocorticoid-induced osteoporotic rats. Four groups of rats (10 rats each) were included in the study; group1 (control group), group 2 (normal exercised) which its rats underwent an exercise protocol, group 3 (osteoporotic rats) where Methylprednisolone was administered intravenously to the rats in order to induce osteoporosis. And group 4 (osteoporotic exercised rats), its rats underwent the same exercise protocol as group 2 after induction of osteoporosis by methylprednisolone. At the end of the study, BMD was measured then the rats were sacrificed and their serum levels of irisin, alkaline phosphatase (ALP), total calcium, serum C-terminal telopeptide of type I collagen (CTX1) were measured, Osteocalcin (OCN) and Osterix (OSX) mRNA in bone tissues were also assessed. Bone microarchitecture was also histologically examined. The study results revealed that exercise improved BMD, increased the levels of serum irisin, ALP, total calcium, (OCN) and (OSX) mRNA levels with decreased serum CTX1 levels. Furthermore there was significant difference in microarchitecture of bone in normal exercised and osteoporotic exercised rats as compared to control and osteoporotic rats, respectively. Moreover, significant positive correlations were found between serum irisin levels and each of BMD, OCN and OSX mRNA and osteocytes and osteoblasts numbers. Conversely, a negative correlation was found between serum irisin level and CTX1.In conclusion, this study highlighted irisin as a new target for preservation of bone in glucocorticoid-induced osteoporosis.

Vitamin D(3) and methylenebisphosphonic acid in the correction of mineral metabolism disorders and bone remodeling associated with glucocorticoid-induced osteoporosis

The study was aimed at evaluating therapeutic efficacy of vitamin D3 (VD3, 1000 IU/kg of b.w., 30 days) and sodium salt of methylenebisphosphonic acid (MBPA, 17 mg/kg of b.w., 30 days) monotherapies as well as their effect in combination in preventing mineral metabolism and bone remodeling disturbances associated with glucocorticoid(GC)-induced osteoporosis. Osteoporosis in rats was induced by long-term (30 days) administration of the synthetic glucocorticoid prednisolone (5 mg/kg of b.w.). Calcium and inorganic phosphate levels, activity of alkaline phosphatase (ALP) in serum, bone tissue and bone marrow were determined spectrophotometrically. The protein levels of VD3 receptor (VDR), receptor activator of nuclear factor kappa-B (RANK), its ligand (RANKL), and osteoprotegerin (OPG) in bone tissue were determined by Western blotting. Serum 25-hydroxyvitamin D3 (25OHD3) content was assayed by ELISA. It was shown that prednisolone caused the development of hypocalcemia and hypophosphatemia, increased the alkaline phosphatase activity in the blood serum, while downregulating its activity in bone tissue and bone marrow. GC-induced osteoporosis was accompanied by a profound deficiency of VD3 and a decrease in the content of VDR. Evaluation of the NF-κB-associated cytokine axis RANK/RANKL/OPG, which regulates the balance of osteoblasts/osteoclasts, showed a simultaneous decrease in the RANK content and OPG/RANKL ratio. Vitamin D3 restored mineral metabolism and 25OHD3 level that led to the normalization of VDR-mediated signaling­ and RANK/RANKL/OPG functions in bone tissue. It has been shown that the administration of MBPA had a corrective effect on the content of mineral components in the blood serum and bone tissue, as well as on the activity­ of alkaline phosphatase only in combination with vitamin D3, indicating a low efficiency of bisphosphonate monotherapy in GC-induced vitamin D3 deficiency and osteoporosis. Keywords: bone remode­ling, glucocorticoid-induced osteoporosis, methylenebisphosphonic acid, RANK/RANKL/OPG axis, vitamin D3

Metabolomics analysis of the potential mechanism of Yi-Guan-Jian decoction to reverse bone loss in glucocorticoid-induced osteoporosis

BackgroundGlucocorticoid-induced osteoporosis (GIOP) is a disease in which long-term use of glucocorticoid causes bone loss, deterioration of bone microstructure and fracture. Currently, clinical drugs targeting this disease have certain side effects. There is still a need to find effective drugs with fewer side effects. The theory of traditional Chinese medicine suggests that YGJ has therapeutic effect on GIOP, but it has not been explained. Therefore, this study aims to explore the protective effect of YGJ on GIOP mouse models and elucidate the underlying mechanism through LC–MS-based metabolomics analysis.MethodsThe general condition of 8 week age male C57BL/6J mice was recorded after 8 weeks of treatment with dexamethasone (DEX) and YGJ. Bone-related parameters and bone morphology were determined by Micro-CT. HE staining was used to observe the pathological changes of bone tissue. Serum levels of bone metabolism markers were detected by ELISA. Liver metabolomics analysis was conducted to search for the significant markers of anti-GIOP of YGJ and the metabolic pathway affecting it.ResultsAfter treatment, YGJ significantly reversed the weight loss caused by DEX; increase the number of bone trabecular in ROI region, significantly improve the bone-related parameters of GIOP mice, and increase the levels of alkaline phosphatase and osteocalcin. In the study of metabolic mechanism, YGJ reversed 24 potential markers in GIOP mice. These included cortisol, 3-hydroxybutyric acid, taurine, esculin and uric acid, which are closely associated with osteoporosis. Topological analysis results showed that YGJ had the most significant effect on taurine and hypotaurine metabolism, with − log10 (P) > 2.0 and Impact > 0.4.ConclusionsYi-Guan-Jian decoction can increase bone density and improve bone microstructure by regulating the levels of alkaline phosphatase and osteocalcin and reverse bone loss in GIOP mouse model. The underlying metabolic mechanism may be related to taurine and hypotaurine metabolic pathway.

Guidelines for diagnosis and treatment of glucocorticoid-induced osteoporosis

Glucocorticoid-induced osteoporosis (GIOP) is a skeletal disease characterized by decreased bone strength and increased fracture risk associated with long-term glucocorticoid use. GIOP is the most common secondary osteoporosis that critically affects the quality of life of patients. Currently, the incidence of GIOP in China remains high, with insufficient awareness and lack of prevention and treatment norms. Therefore, the Chinese Rheumatology Association has established this standard based on domestic and international experience, with the aim of raising awareness of prevention and treatment among clinicians, guiding the standardized diagnosis and treatment of this disease, and improving the overall prognosis of patients with GIOP.

Andrographolide protects BMSCs from dexamethasone-induced cellular dysfunction and promotes bone formation via the PI3K/AKT pathway

Osteoporosis is a common metabolic disease with high morbidity and mortality in the elderly, bringing a heavy socioeconomic burden. Excess use of glucocorticoid is the main cause of secondary Osteoporosis, and there are limited therapies for glucocorticoid-induced osteoporosis (GIOP) treatment. In this study, we explored the protective effect of andrographolide (AGP) on dexamethasone (DEX)-induced dysfunction and osteogenic inhibition in vitro and in vivo. The results showed that AGP could alleviate DEX-induced cytotoxicity, apoptosis and senescence in BMSCs. AGP also increased the level of calcium nodules, RUNX2, COL1A1, OCN and ALP in DEX-treated BMSCs, suggesting that AGP promoted osteogenic differentiation. We found that AGP activated PI3K/AKT signaling pathways and the PI3K inhibitor LY294002 reversed the protective effects of AGP. Additionally, in the GIOP mice model, AGP alleviated bone loss in vivo. In conclusion, these results demonstrated that AGP has a protective effect and promoted bone formation against GIOP through PI3K/AKT pathway.

PartII: Interactive case:Drug‐inducedendocrine disorders

Part<scp>II</scp>: Interactive case:<scp>Drug‐induced</scp>endocrine disorders

Cmpk2 regulates mitochondrial function in glucocorticoid-induced osteoblast senescence and affects glucocorticoid-inhibited osteoblast differentiation

Mitochondrial dysfunction plays a crucial role in the development of glucocorticoid-induced osteoporosis (GIO). Cytidine monophosphate kinase 2 (Cmpk2), an essential mitochondria-associated gene, promotes the production of free mitochondrial DNA, which leads to the formation of inflammasome-mediated inflammatory factors. However, the specific role of Cmpk2 in GIO remains unclear. In this study, we report that glucocorticoids induce cellular senescence within the bone, particularly in bone marrow mesenchymal stem cells and preosteoblasts. We discovered that glucocorticoids cause mitochondrial dysfunction in preosteoblasts, increasing cellular senescence. Moreover, we observed elevated expression of Cmpk2 in preosteoblasts following glucocorticoid exposure. Inhibiting Cmpk2 expression alleviates glucocorticoid-induced cellular senescence and promotes osteogenic differentiation by improving mitochondrial function. Our study uncovers new mechanisms underlying glucocorticoid-induced senescence in stem cells and preosteoblasts, highlighting the potential of inhibiting the mitochondrial gene Cmpk2 to reduce senescence and enhance osteogenic differentiation. This finding offers a potential therapeutic approach for the treatment of GIO.

Bisphosphonate use for glucocorticoid-induced osteoporosis in older patients with immune thrombocytopenia: a clinical perspective.

Prednisolone, used as a standard initial treatment for immune thrombocytopenia (ITP), is an important risk factor for osteoporosis. Recently, we found that prescription of bisphosphonate during initial loading of prednisolone may prevent reduction in bone mineral density and development of glucocorticoid-induced osteoporosis (GIO) in older patients with ITP receiving prolonged steroid therapy. In this review, I describe the treatment options for older patients with ITP, and present the best practices for screening, evaluating, and diagnosing ITP. I also summarize the literature from 2017 to 2022 on the treatment options for ITP, including discussions on the contraindications and side effects, with an emphasis on GIO, and the relative merits of bisphosphonates as a co-treatment for prevention of GIO. Finally, I present a perspective and an expert recommendation on how older patients with ITP would best be served in the future.

Effects of genistein aglycone in glucocorticoid induced osteoporosis: A randomized clinical trial in comparison with alendronate

Glucocorticoid-induced osteoporosis (GIO) complicates the clinical management of patients subjected to long-term glucocorticoid use. This study explored the effects of genistein on bone loss in a randomized double-blind alendronate-controlled trial in postmenopausal women with GIO. 200 postmenopausal women (taking at least 5 mg of prednisone equivalents) since 3 months, or more, and expected to continue for at least other 12 months, were randomized to receive genistein (54 mg/day daily) or alendronate (70 mg once a week) for 24 months. Both groups received also Calcium and Vitamin D3 supplementation. Median bone mineral density (BMD) at the antero-posterior lumbar spine significantly increased from 0.75 g/cm2 at baseline to 0.77 g/cm2 at 1 year and 0.79 g/cm2 at 2 years in alendronate-treated patients and from 0.77 g/cm2 at baseline to 0.79 g/cm2 at 12 months and to 0.80 g/cm2 at 24 months in genistein recipients. No difference was observed between the two treatments. Median BMD at the femoral neck increased from 0.67 g/cm2 at baseline to 0.68 g/cm2 at 1 year and 0.69 g/cm2 at 2 years in alendronate-treated patients and from 0.68 g/cm2 at baseline to 0.70 g/cm2 at 12 months and to 0.71 g/cm2 at 24 months in genistein recipients. No difference was observed between alendronate and genistein groups in BMD. Regarding bone markers genistein and alendronate statistically decreased c-terminal telopeptide, while osteocalcin, bone-ALP, and sclerostin showed greater changes in genistein treated patients. This randomized clinical trial suggests that genistein aglycone represents an additional therapeutic option for patients with GIO.

Administration of necrostatin-1 ameliorates glucocorticoid-induced osteonecrosis of the femoral head in rats.

Glucocorticoid (GC)-induced osteonecrosis of the femoral head (ONFH) is a serious complication of glucocorticoid treatment and is characterized by dysfunctional bone reconstruction at necrotic sites. Our previous study confirmed the protective potential of necrostatin-1, a selective blocker of necroptosis, in glucocorticoid-induced osteoporosis. In this study, rat models of GC-induced ONFH were established to evaluate the effects of necrostatin-1 on osteonecrotic changes and repair processes. Osteonecrosis was verified by histopathological staining. An analysis of trabecular bone architecture was performed to evaluate osteogenesis in the osteonecrotic zone. Then, necroptotic signaling molecules such as RIP1 and RIP3 were examined by immunohistochemistry. Histopathological observations indicated that necrostatin-1 administration reduced the incidence of osteonecrosis and the osteogenic response in subchondral areas. Additionally, bone histomorphometry demonstrated that necrostatin-1 intervention could restore bone reconstruction in the necrotic zone. The protective mechanism of necrostatin-1 was related to the inhibition of RIP1 and RIP3. Necrostatin-1 administration alleviated GC-induced ONFH in rats by attenuating the formation of necrotic lesions, recovering the function of osteogenesis, and suppressing glucocorticoid-induced osteocytic necroptosis by inhibiting the expression of RIP1 and RIP3.

Prevalence of glucocorticoid-induced osteoporosis among rheumatology patients in Africa: a systematic review and meta-analysis.

The prevalence of glucocorticosteroid-induced osteoporosis (GIOP) is well established in developed countries, but little is known about GIOP in African adult patients with inflammatory rheumatic musculoskeletal diseases (RMDs). This study aimed to determine the prevalence of GIOP and osteoporotic fracture risk in African patients with inflammatory RMDs according to radiographic and bone mineral density (BMD) findings. PubMed, Google Scholar, Scopus, and African Index Medicus were searched up to 31 December 2020. Heterogeneity was assessed using I2 statistic across the included studies. A random-effects model was applied to estimate the pooled effect size across studies. All statistical analyses were performed using STATA™ version 14 software. The study was registered with PROSPERO, number CRD42021256252. In this meta-analysis, a total of 7 studies with 780 participants, stratified by geographical region were included. The pooled prevalence of GIOP based on BMD data was 47.7% (95% CI 32.9-62.8) with 52.2% (95% CI 36.5-67.6) in North African countries and 15.4% (95% 1.9-45.4%) in South Africa with a high heterogeneity (I2 = 93.3%, p = 0.018). There was no data from the rest of African countries. We were unable to complete the meta-analysis of osteoporotic fractures due to the lack of available data. This study revealed that the prevalence of GIOP varies significantly in Africa. There is no information, however, for most of Africa, and further prospective studies are needed to develop context-specific GIOP preventive strategies in patients with RMDs.

Threshold based on bone mineral density for therapeutic decision-making in postmenopausal women and men over 50 years old under glucocorticoid therapy

Introduction and aimT-score bone mineral density (BMD) thresholds may influence guidance for treatment in patients under glucocorticoid (GC) therapy. Different BMD thresholds have been described but there is no international consensus. The aim of this study was to find a threshold to help in treatment decision-making in the population under GC therapy. MethodsA working group representing three scientific societies from Argentina was convened. The first team was formed by specialists with expertise in glucocorticoid-induced osteoporosis (GIO) who voted according to summary of evidence. The second team was constituted by a methodology group who coordinated and supervised each stage. We conducted two systematic reviews to synthesize the evidence. The first included trials of drugs used in GIO to analyze the BMD cut-off used as inclusion criteria. In the second, we analyzed the evidence regarding the densitometric thresholds to discriminate between fractured and non-fractured patients under GC treatment. ResultsIn the first review, 31 articles were included for qualitative synthesis and more than 90% of the trials included patients regardless of their densitometric T-score or range of osteopenia. In the second review, 4 articles were included and more than 80% of the T-scores were in the range −1.6 to −2.0. The summary of findings was analyzed and put to a vote. ConclusionsWith more than 80% agreement of the voting expert panel, a T-score≤−1.7 was considered the most appropriate for treatment in postmenopausal women and men over 50 years of age under GC therapy. This study could help in treatment decision-making in patients under GC therapy without fractures but other fracture risk factors should certainly be considered.

GVHD in its sclerodermiform form revealing type 1 diabetes: A case report

Sclerodermiform syndrome is Common in diabetic, it encompasses a set of manifestations that preferentially affect the hands and back, but the association of type 1 diabetes with systemic sclerosis is a rare entity. We report the case of 18-year-old patient from a consanguineous marriage, with a history of acute myeloid leukemia which he was treated by an allograft in France associated with chemotherapy 9 session and immunosuppressants currently in complete remission, diabetic type 1 for 4 years, hypothyroidism under levothyrox 50ug / d. At the interrogation the patient reported the consequences of the graft were marked by stage I cutaneous GVHD confirmed by skin biopsy of which he received corticosteroid therapy at a dose of 10mg / day in addition to neoral or slightly atrophic hyperpigmented macules not sclerotic at the level of the back and the lateral surface of the left foot. The patient also had corticosteroid-induced complications, including diabetes and osteoporosis. On physical examination tendon retraction, elbows and finger, Amyotrophy of the hands, palpable thyroid not increased volume allowed for glycemic imbalance. At TSH biology = 6uui / ml, HBA1C = 8%, anti-GAD antibody negative to cervical ultrasound: thyroid hypotrophy with thyroid nodules classified EUTIRADS 2. The patient is referred for follow-up in dermatology. The association of sweet diabetes and sclerodermiform lesions is frequently linked to the glycemic imbalance responsible for an accumulation of extracellar matrix and excessive glycation of collagen. The search for signs of scleroderma should be evoked in front of a diabetic hand syndrome to Watch for and treat associated pathologies.

Protective role of 3-oxypyridine derivatives in rats’ steroid-induced osteoporosis associated with reduced oxidative stress and recovery of nitric oxide formation

From the point of view of the mechanisms for the implementation of pathogenetic links in the development of steroid-induced osteoporosis considered in the paper, the increased risk of the oxidative stress in osteoblasts, as well as the development of the vessels endothelial dysfunction of the microcirculatory bloodstream in the bone tissue, are of particular interest. They lead to the impaired bone tissue trophism and progression of osteoporosis.The aim of the study was research of the osteoprotective effects of a 3-hydroxypyridine derivatives composition on the model of steroid-induced osteoporosis.Materials and methods. To model osteoporosis pathology, the animals (male Wistar rats) were injected with methylprednisolone (MP) at the dose of 5 mg/kg (intraperitoneally) every 5th day for 5 weeks. Аs a non-selective blocker of NO synthase, L-NAME was used at the dose of 25 mg/kg (intraperitoneally). Derivatives of 3-hydroxypyridine (hereinafter referred to as composition No. 1) were administrated at the dose of 50 mg/kg (per os) In all experimental groups, the level of microcirculation and the bone mineral density, as well as the analysis of histomorphological and biochemical samples, were assessed.Results. The study results showed that composition No. 1 (50 mg/kg) has an osteoprotective activity, effectively prevents a decrease in the level of the regional bone tissue microcirculation and in the development of an endothelial dysfunction. That makes it possible to increase the bone mineral density and to slow down the thinning of bone trabeculae. In addition, composition No. 1 (50 mg/kg) reduces the production of reactive oxygen species and increases the NO bioavailability.Conclusion. The data obtained indicate that the studied composition of 3-hydroxypyridine derivatives is considered a promising compound for the prevention and treatment of steroid-induced osteoporosis.

Pathogenesis of glucocorticoid-induced osteoporosis based on label-free mass proteomics

To explore pathogenesis of glucocortocoid-induced osteoporosis(GIOP) based on label-free mass proteomics. Twevle female Sprague-Dawley(SD) rats were randomly divided into two groups, named as sham group and GIOP group. After one-week adaptive feeding, the rats of GIOP group were administered with dexamethasone via intramuscular injection according to 2.5 mg/kg weighting, while the rats of sham group were administered with the same amount of saline, twice a week. The tibias of each group were collected after 8-week modeling and made pathological sections to confirm the success of modeling. Three samples of each group were picked up to perform label-free mass proteomics. After quality control, differentially expressed proteins were identified according to qualitative and quantitative analyses. Then gene ontology(GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis, cluster analysis as well as protein-protein interaction analysis were performed using bioinformatics analysis. Compared with sham group, the structure of bone trabecular in GIOP group showed abnormal arrangement, uneven distribution and obvious fragmentation, which could demonstrate successful modeling. A total of 47 differentially expressed proteins (DEPs) were identified including 20 up-regulated and 27 down-regulated proteins. The expression of protein nucleophosmin 1(NPM1), adipocyte plasma membrane associated protein (APMAP), cytochromec oxidase subunit 6A1 (COX6A1) and tartrate-resistant acid phosphatase (ACP5) showed a significant difference between two groups. KEGG results showed DEPs were enriched on metabolism-related pathways, immune-related pathways and AMP-activated kinase (AMPK) signaling pathway. Protein NPM1, APMAP, COX6A1 and ACP5 showed a close relationship with pathogenesis of GIOP, which could serve as potential biomarkers of GIOP. AMPK signaling pathway played an important role in the occurrence and development of GIOP, which could be regarded as potential signaling pathway to treatment GIOP.