Abnormal Bone Metabolism Research Articles

Clinical efficacy and outcomes of calcitriol combined with bisphosphonates in the treatment of postmenopausal osteoporosis: A quasi-experimental study.

A quasi-experimental study was conducted to investigate the clinical efficacy and outcomes of calcitriol combined with bisphosphonates in the treatment of postmenopausal osteoporosis (OP). A total of 152 patients with postmenopausal OP from March 2019 to June 2021 were enrolled. The patients who received calcitriol treatment were adopted as the control group, and the patients treated with calcitriol combined with bisphosphonates were considered as the intervention group. The treatment effects of patients were compared, and the pain degree of the joints of the patients was evaluated by Visual Analogue Scale/Score (VAS), the Barthel Index score was used to evaluate the daily living ability of patients, the hand and Oswestry Disability Index (ODI) were used to evaluate the dysfunction before and after treatment, and the bone metabolism indexes, immune cytokines and bone mineral density were detected before and after treatment, and the incidence of adverse reactions was calculated. Regarding the therapeutic effects, the intervention group indicated an effective rate of 96.05% while the effective rate was 84.21% in the control group. The total effective rate of treatment in the intervention group was higher than the control group. The VAS, ODI scores, and bone metabolism indexes of the intervention group were significantly lower than the control group at 1, 2, and 3 months after treatment. The Barthel Index scores and bone mineral density of the intervention group were higher than the control group at 1, 2, and 3 months after treatment. The improvement of immune cytokines in the intervention group was significantly better than the control group (P < .05). One patient in the intervention group developed dizziness and 1 patient developed chills, with an adverse reaction rate of 2.63%, while in the control group, 2 patients had fever, and 2 patients developed chills, with an adverse reaction rate of 5.26% (P > .05). Calcitriol combined with bisphosphonates has a significant clinical effect in the treatment of postmenopausal OP, which can significantly relieve bone pain in postmenopausal OP patients, enhance abnormal bone metabolism and immune function, and promote bone mineral density and daily living ability.

The Acetylated 2,3,5,4′-Tetrahydroxystilbene-2-O-β-d-Glucoside Improved Pharmacokinetics and Enhanced Anti-Osteoporosis Effects

Background: Osteoporosis has emerged as a significant global public health concern, predominantly affecting postmenopausal women. Its pathogenesis is intricate and the disease course is protracted, imposing substantial medical burden on both society and individuals. Objective: To investigate the effects of 2,3,5,4′-tetrahydroxystilbene-2-O-β-d-glucoside (TSG) and acetylated-TSG (Ac-TSG) on osteoblast viability, in vivo pharmacokinetics in rats and anti-osteoporotic effects in ovariectomized rat model. Methods: Ac-TSG was obtained by acetylation of TSG, and the purity and structure of Ac-TSG were determined by HPLC and 1H NMR. The effects of TSG and Ac-TSG on MC3T3-E1 cell viability, pharmacokinetics in rats, blood biochemical indexes of OVX model rats were detected. Hematoxylin–eosin (HE) staining was used to observe bone tissue morphology, tartrate-resistant acid phosphatase (TRAP) staining was used to observe osteoclast morphology, micro-CT was used to perform three-dimensional reconstruction of femur, and femur parameters were analyzed. Results: The structure of the compound is Ac-TSG and the purity is more than 98%. Both TSG and Ac-TSG could reduce the damage of oxidative stress to MC3T3-E1 cells and effectively improve the levels of Ca, P, ALP and BGP in serum of OVX rats. Compared with TSG, Ac-TSG has a longer action time in vivo and can improve the femoral structure, the number of trabecular bone and the number of osteoclasts in rats. Conclusion: Ac-TSG conferred protection to MC3T3-E1 cells against oxidative stress-induced damage and enhanced their bioavailability. Simultaneously, Ac-TSG ameliorated abnormal bone metabolism and mitigated bone microstructural changes in OVX rats, exhibiting a protective effect against osteoporosis.

Short and long-term effects of kidney donation on mineral and bone metabolism

BackgroundLiving kidney donors (LKD) experience an abrupt decline in glomerular filtration rate (GFR) resulting in abnormalities of mineral and bone metabolism (MBD), and this may have implications for skeletal health. We prospectively studied acute and long term MBD adaptation of LKD from two kidney transplant centers (São Paulo, Brazil and Miami, USA).MethodsRenal function and MBD parameters longitudinally after kidney donation (baseline – D0, day 1, 14, 180 and 360 post-operatively) were measured in 74 patients (40 y, 73% female, 54% Brazilian). A subset of 20 donors from Brazil were reassessed after 10 years of nephrectomy.ResultsAt baseline, Brazilian donors presented lower intact FGF23 (20.8 vs. 80.1 pg/mL, P < 0.01) and higher PTH (47.4 vs. 40.1, P = 0.04) than their US counterparts. GFR decreased to 63% of its baseline levels just after donation but improved 10% during the first year. PTH levels increased on D1, returning to baseline levels on D14, while FGF23 remained higher than baseline over the first year. LKD had a significant reduction of serum phosphate on D1, which returned to baseline levels on D180. A higher fractional excretion of phosphate (FEP) was noted since D14. After 10 years of donation, 20 LKD presented a sustained reduction in GFR (74.8 ± 14mL/min). There was a return to baseline in serum FGF23 [21.8 (18–30) pg/mL] and FEP, accompanied by an increase in serum calcium. PTH remained elevated (57.9 ± 18 pg/mL), whereas serum calcitriol and Klotho were lower than before the donation.ConclusionsThe abrupt decline in kidney mass is associated with an increase in PTH and FGF23 that is not explained by phosphate retention. In a long-term evaluation, LKD showed a sustained drop in GFR, with lower serum calcitriol and Klotho, and higher PTH. The effects of these changes should be investigated in further studies.

A Large Brown Tumor of Mandible as First Manifestation of Hyperparathyroidism

ABSTRACT Brown tumor is a lesion that develops in patients with hyperparathyroidism. It can be described as the terminal stage of bone remodeling process where abnormal bone metabolism takes place. Hyperplasia or adenoma of the parathyroid glands is the main etiology of primary hyperparathyroidism (HPT). Due to overproduction of parathyroid hormone in hyperparathyroidism bone resorption takes place, which appear as cyst-like lesions, commonly known as osteitis fibrosa cystica or brown tumor. Any skeletal bones, including jawbones can be affected in this disorder. Most of the time brown tumor is detected after confirmatory diagnosis of hyperparathyroidism. Presentation of brown tumor as the first manifestation of this disorder is rare. In this present report, a large proliferative growth in left jaw with multilocular radiolucency in 23 years aged female was described as an unusual first manifestation of hyperparathyroidism.

Adverse events associated with carbamazepine: a pharmacovigilance study using the FDA Adverse Event Reporting System

ABSTRACT Introduction Carbamazepine (CBZ) is a commonly used antiseizures medications (ASM), but its adverse drug reactions (ADRs) can impact the successful management of epilepsy. There are currently limited systematic studies on ADRs related to CBZ, necessitating further investigation. Areas covered Using the FDA Adverse Event Reporting System (FAERS) database , we extracted reports where CBZ was the primary suspect, conducting subgroup analyses stratified by sex and age. Four risk signal detection methods ROR, PRR, BCPNN, and EGBM were employed to systematically analyze the ADRs associated with CBZ. Expert opinion In the epilepsy population, ADRs related to CBZ often involve examinations, hereditary disorders, and infections. Subgroup analysis showed differences in ADR signals among male, female, elderly, and young patients. Human Herpesvirus 6 Infection and Dermatitis Exfoliative were consistent CBZ-induced ADRs, unaffected by age or sex. The study also identified previously overlooked ADRs such as bone metabolism abnormalities, ocular toxicity, and ototoxicity. Many ADRs linked to CBZ remain underreported. It is crucial to enhance monitoring and information dissemination about CBZ use in epileptic patients. Adjusting medication regimens for high-risk individuals, potentially incorporating acupuncture, traditional Chinese medicine, or alternative anti-seizure medications, should be considered when necessary.

Integrated transcriptomics and untargeted metabolomics reveal bone development and metabolism of newly weaned mice in response to dietary calcium and boron levels.

Epidemiological and animal studies have indicated that calcium and boron are essential for bone development and metabolism. However, limited information is available regarding the effects of boron supplementation on bone development and metabolism in newly weaned infants with either calcium deficiency or calcium sufficiency. This study assessed the effects of dietary boron supplementation (0 and 3 mg kg-1) on bone development and metabolism, in a newly weaned mouse model, under both calcium deficiency and sufficiency feeding conditions. The results show that mice fed a calcium sufficient diet exhibited lower fat percentage and final body weight than those fed a calcium deficient diet. Boron supplementation reduced the serum high-density lipoprotein cholesterol level and up-regulated the mRNA levels of FABP3, PPAR-γ, and CaMK in the intestinal mucosa. Importantly, boron supplementation increased the tibial weight in mice on a calcium-sufficient diet and enhanced the tibial volume in those on a calcium-deficient diet. Metabolomic analysis highlighted calcium and boron's impact on metabolites like carboxylic acids and derivatives, fatty acyls, steroids and steroid derivatives, benzene and substituted derivatives, organonitrogen compounds, organooxygen compounds, and phenols, and were related to lipid metabolism and the neural signaling pathway. Transcriptomic analysis corroborated the role of calcium and boron in modulating bone metabolism via the JAK-STAT, calcium signaling, lipid metabolism, and inflammatory pathways. Multi-omics analysis indicated a strong correlation between calcium signaling pathways, lipid metabolism signaling, and dietary calcium and boron contents. This research provides insights into these complex mechanisms, potentially paving the way for novel interventions against calcium and boron deficiencies and bone metabolism abnormalities in clinical settings.

Evaluation of Functional Components of Lactobacillus plantarum AR495 on Ovariectomy-Induced Osteoporosis in Mice And RAW264.7 Cells

Osteoporosis is a disease characterized by abnormal bone metabolism, where bone resorption outpaces bone formation. In this study, we investigated the key functional components of Lactobacillus plantarum AR495 in mitigating ovariectomy (OVX)-induced osteoporosis in mice. The results indicated that both Lactobacillus plantarum AR495 and its fermentation broth significantly reduced urinary calcium and deoxypyridinoline (DPD) levels in the mice. These interventions inhibited bone resorption and improved trabecular bone architecture by modulating the nuclear factor κB (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) signaling pathway. Additionally, the L. plantarum AR495 and fermentation broth groups inhibited the RANKL/TRAF-6 and TLR4/MYD88 pathways, leading to enhanced bone metabolism, improved intestinal barrier function, and reduced intestinal inflammation. In vitro experiments revealed that AR495 fermentation supernatant fractions larger than 100 kDa and those between 50–100 kDa significantly decreased the activity of the osteoclast marker TRAP, regulated the expression of the TLR4/MYD88 pathway, and inhibited osteoclast formation, thereby alleviating the OVX-induced osteoporosis phenotype. These findings suggest that these components may be primary functional elements of L. plantarum AR495 in the treatment of osteoporosis.

Etelcalcetide ameliorates bone loss in chronic kidney disease-mineral and bone disorder by activation of IRF7 and necroptosis pathways

Chronic kidney disease-mineral and bone disorder (CKD-MBD) is a multifaceted clinical syndrome characterized by mineral imbalances, abnormalities in bone metabolism, chronic inflammation and vascular calcification. Etelcalcetide, a second-generation intravenous calcimimetic agent, has been approved for treating high-turnover renal osteodystrophy, effectively targeting the pathophysiological mechanisms underlying this condition. We investigate the impacts of etelcalcetide on osteoclast (OC) differentiation and functionality in CKD-MBD via three critical mechanisms: inflammation initiated by interferon regulatory factor 7 (IRF7), receptor-interacting protein (RIP)-mediated necroptosis and apoptosis-induced cell death. The low-dose (CKD + L) or high-dose (CKD + H) of etelcalcetide groups significantly improved biochemical markers compared to the CKD control mice. Additionally, etelcalcetide-treated CKD mice significantly improved cortical and trabecular bone parameters. In an in vitro study, etelcalcetide was observed to bolster the IRF7-mediated IFNβ response in OC differentiation. Furthermore, it stimulated RIP-mediated necroptosis via RIP and MLKL activation, inhibiting bone resorption. Moreover, the drug increased levels of caspases 3 and 9, inducing cell death in OCs. These findings suggest that etelcalcetide regulates bone metabolism and reduces skeletal issues in CKD-MBD. Etelcalcetide likely enhances bone parameters in CKD-MBD mice by regulating IRF7 pathways and inhibiting OC differentiation. It also improves bone health and promotes RIP-mediated necroptosis and apoptosis pathways within OCs.

Elevations of N-Terminal Mid-Fragment of Osteocalcin and Cystatin C Levels are Associated with Disorders of Glycolipid Metabolism and Abnormal Bone Metabolism in Patients with Type 2 Diabetes Mellitus Complicated with Osteoporosis

Abstract Type 2 diabetes mellitus (T2DM) patients always develop osteoporosis (OP). We examined correlations of N-terminal mid-fragment of osteocalcin (N-MID) and cystatin C (Cys C) levels with glycolipid metabolism, bone metabolism markers, and bone mineral density (BMD) in elderly T2DM-OP patients. Grouping was performed as per whether T2DM patients developed OP (OP group) or not (N-OP group). N-MID and Cys C were measured using enzyme-linked immunosorbent assay, with correlations with glycolipid metabolism, bone metabolism indicators, and BMD analyzed using Pearson’s correlation coefficient. Elderly T2DM-OP patients showed elevated disease duration, age, body mass index, glycated hemoglobin (HbA1c), Homer’s insulin resistance (HOMA-IR), total cholesterol (TC), beta-carboxy-terminal crosslinked telopeptide of type 1 collagen (β-CTX), tartrate-resistant acid phosphatase 5b (TRACP-5b), N-MID and Cys C levels, and reduced high-density lipoprotein cholesterol (HDL-C), bone alkaline phosphatase (B-ALP), aminoterminal propeptide of type I procollagen (PINP), carboxyterminal propeptide of type I procollagen (PICP), BMD, and calcium supplementation. N-MID and Cys C were positively correlated with HbA1c, HOMA-IR, TC, β-CTX, and TRACP-5b and negatively with HDL-C, B-ALP, PINP, PICP, and BMD in elderly T2DM-OP patients. Conclusively, the abnormal elevations of serum N-MID and Cys C were associated with glycolipid metabolism disorder, abnormal bone metabolism, and decreased BMD in elderly T2DM-OP patients.

Radiological Appearance of Brown Tumors of the Maxilla Indicative of Primary Hyperparathyroidism: A Case Report

Brown tumors are a rare complication of hyperparathyroidism resulting from abnormalities in bone metabolism. Advances in biological exploration techniques enable early diagnosis before the onset of bone manifestations. While mandibular involvement is the most common in the maxillofacial region, maxillary involvement is extremely rare. We report a case of a patient with primary hyperparathyroidism revealed by a maxillary tumor. The pathological result concluded a benign giant cell tumor of the maxilla and fibrous dysplasia. The diagnosis of a brown tumor was considered based on the association of radiological data (osteolytic image and parathyroid adenoma), histological findings (giant cell tumor), and biological markers (hypercalcemia, hypophosphatemia, and elevated Parathyroid Hormone (PTH). This case highlights the difficulty in establishing a correct diagnosis in patients with an osteolytic maxillary process and the need to investigate hyperparathyroidism in the presence of a giant cell lesion.

RANK-RANKL-OPG Axis in MASLD: Current Evidence Linking Bone and Liver Diseases and Future Perspectives.

Metabolic dysfunction-associated steatotic liver disease (MASLD)-and its worse form, metabolic-associated steatohepatitis (MASH), characterised by inflammation and liver damage-corresponds to the liver's involvement in metabolic syndrome, which constitutes an economic burden for healthcare systems. However, the biomolecular pathways that contribute to steatotic liver disease are not completely clear. Abnormalities of bone metabolism are frequent in people affected by metabolic liver disease, with reduced bone density and an increased risk of fracture. Receptor activator of NF-κB (RANK), receptor activator of NF-κB ligand (RANKL), and osteoprotegerin(OPG) are critical regulators of bone metabolism, performing pleiotropic effects, and may have potential involvement in metabolic disorders like MASLD, resulting in a topic of great interest and intrigue. This narrative review aims to investigate this potential role and its implications in MASLD development and progression and in hepatocellular carcinoma, which represents its worst complication.

Heraclenin promotes the osteogenic differentiation of bone marrow stromal cells by activating the RhoA/ROCK pathway.

Osteoporosis is a devastating skeletal disease, the pathogenesis of which is related to abnormal bone metabolism, featured by the imbalance between osteoblastic bone formation and osteoclastic bone resorption. Stem cell-based therapies have been demonstrated to improve osteoporosis treatment. Previously, the linear furanocoumarin heraclenin was reported to enhance osteoblast differentiation and mineralization in mouse mesenchymal stem cells (MSCs), suggesting its potential for osteogenic differentiation and bone regeneration. Our study was designed to confirm the promotive role of heraclenin on osteogenic differentiation of human bone MSCs (BMSCs) and explore the underlying mechanisms. Human BMSCs were treated for 24, 48, and 72h with heraclenin (5, 10, 20, 40, and 80 μM), and cell viability was determined by Cell Counting Kit-8 (CCK-8) assay. To further evaluate the cytotoxicity of heraclenin, cell suspension obtained from BMSCs treated with heraclenin (5, 10, and 20 μM) for 72h was subjected to a MUSE™ cell analyzer for cell viability and count assay. BMSCs were incubated in osteogenic induction medium for 7 days. Then, osteogenic differentiation and mineralization of BMSCs were assessed through alkaline phosphatase (ALP) and Alizarin Red S staining. The expression of osteogenesis markers including ALP, osteocalcin (OCN), osterix (OSX), and runt-related transcription factor 2 (RUNX2) was detected via reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blotting. The effects of heraclenin on the RhoA/ROCK pathway were estimated through western blotting. Y-27632, the ROCK inhibitor, was used to confirm the role of the RhoA/ROCK pathway in heraclenin-mediated osteogenic differentiation of BMSCs. Heraclenin (5-80 μM) was non-toxic on human BMSCs. Heraclenin treatment (5-20 μM) dose-dependently enhanced ALP activity and calcium deposition. Furthermore, heraclenin promoted ALP, OCN, OSX, and RUNX2 mRNA and protein expression. Mechanically, heraclenin treatment increased RhoA and ROCK1 mRNA expression, stimulated the translocation of ROCK from the cytosolic to the membrane fraction, and elevated the protein levels of phosphorylated cofilin (p-cofilin) and active RhoA. Additionally, treatment with Y-27632 overturned the promotion of heraclenin on ALP activity, calcium deposition, the expression of osteogenesis markers, and the RhoA/ROCK signaling pathway. Heraclenin facilitates the osteogenic differentiation of human BMSCs through the activation of the RhoA/ROCK pathway.

Suspected silent pituitary somatotroph neuroendocrine tumor associated with acromegaly-like bone disorders: a case report

BackgroundGrowth hormone (GH) positive pituitary neuroendocrine tumors do not always cause acromegaly. Approximately one-third of GH-positive pituitary tumors are classified as non-functioning pituitary tumors in clinical practice. They typically have GH and serum insulin-like growth factor 1 (IGF-1) levels in the reference range and no acromegaly-like symptoms. However, normal hormone levels might not exclude the underlying hypersecretion of GH. This is a rare and paradoxical case of pituitary tumor causing acromegaly-associated symptoms despite normal GH and IGF-1 levels.Case presentationWe report a case of a 35-year-old woman with suspicious acromegaly-associated presentations, including facial changes, headache, oligomenorrhea, and new-onset diabetes mellitus and dyslipidemia. Imaging found a 19 × 12 × 8 mm pituitary tumor, but her serum IGF-1 was within the reference, and nadir GH was 0.7ng/ml after glucose load at diagnosis. A thickened skull base, increased uptake in cranial bones in bone scan, and elevated bone turnover markers indicated abnormal bone metabolism. We considered the pituitary tumor, possibly a rare subtype in subtle or clinically silent GH pituitary tumor, likely contributed to her discomforts. After the transsphenoidal surgery, the IGF-1 and nadir GH decreased immediately. A GH and prolactin-positive pituitary neuroendocrine tumor was confirmed in the histopathologic study. No tumor remnant was observed three months after the operation, and her discomforts, glucose, and bone metabolism were partially relieved.ConclusionsGH-positive pituitary neuroendocrine tumors with hormonal tests that do not meet the diagnostic criteria for acromegaly may also cause GH hypersecretion presentations. Patients with pituitary tumors and suspicious acromegaly symptoms may require more proactive treatment than non-functioning tumors of similar size and invasiveness.

Advanced glycosylation end products promote the progression of CKD-MBD in rats, and its natural inhibitor, quercetin, mitigates disease progression.

Chronic kidney disease-mineral and bone metabolism disorder (CKD-MBD) is a common chronic kidney disease (CKD)-associated complication that increases the risk of metabolic bone diseases, fractures, osteoblastic trans-differentiation of vascular smooth muscle cells, and cardiovascular events. SD rats were randomised into five groups with six rats per group: sham, CKD, CKD + advanced glycosylation end products (AGEs), CKD + Quercetin, and CKD + AGEs + Quercetin. The protective effects of AGEs and quercetin on SD rats were assessed by renal function, renal pathology, bone metabolism, osteoblastic trans-differentiation of vascular smooth muscle cells, and the receptor for AGE (RAGE) expression. Compared with the control group, rats in the CKD and CKD + AGEs groups had significantly lower body weight, higher serum AGEs levels, impaired renal function, increased levels of oxidative stress in the kidney and bone marrow tissues, lower femoral bone mineral density (BMD), callus mineralised volume fraction (mineralised bone volume/total volume), abnormal serum bone metabolism levels, and increased renal tissue, bone tissue, and abdominal aorta RAGE expression levels, and the RAGE downstream NF-κB signalling pathway was upregulated. Quercetin significantly improved renal dysfunction, attenuated serum AGE levels, reduced oxidative stress levels in the kidney and bone marrow tissues, and downregulated RAGE expression in the kidney, bone, and abdominal aorta and the RAGE downstream NF-κB signalling pathway in rats with CKD. AGEs are involved in the pathogenesis of CKD-MBD by promoting osteoblastic trans-differentiation of vascular smooth muscle cells and abnormal bone metabolism. Quercetin plays a role in the prevention and treatment of CKD-MBD by reducing the production of AGEs.

Exploring the impact of osteoprotegerin on osteoclast and precursor fusion: Mechanisms and modulation by ATP

Osteoclast (OC) differentiation, vital for bone resorption, depends on osteoclast and precursor fusion. Osteoprotegerin (OPG) inhibits osteoclast differentiation. OPG's influence on fusion and mechanisms is unclear. Osteoclasts and precursors were treated with OPG alone or with ATP. OPG significantly reduced OC number, area and motility and ATP mitigated OPG's inhibition. However, OPG hardly affected the motility of precusors. OPG downregulated fusion-related molecules (CD44, CD47, DC-STAMP, ATP6V0D2) in osteoclasts, reducing only CD47 in precursors. OPG reduced Connexin43 phosphorylated forms (P1 and P2) in osteoclasts, affecting only P2 in precursors. OPG disrupted subcellular localization of CD44, CD47, DC-STAMP, ATP6V0D2, and Connexin43 in both cell types. Findings underscore OPG's multifaceted impact, inhibiting multinucleated osteoclast and mononuclear precursor fusion through distinct molecular mechanisms. Notably, ATP mitigates OPG's inhibitory effect, suggesting a potential regulatory role for the ATP signaling pathway. This study enhances understanding of intricate processes in osteoclast differentiation and fusion, offering insights into potential therapeutic targets for abnormal bone metabolism.

#2034 CKD-MBD management: results from a national survey on bone turnover biomarkers practice and therapeutic strategies among Italian nephrologists

Abstract Background and Aims Advanced stages of chronic kidney disease (CKD) are constantly characterized by a mineral and bone disorders (MBD) syndrome concerning a complex systemic condition that includes laboratory abnormalities of bone and mineral metabolism involving calcium, phosphorus, parathyroid hormone (PTH), or vitamin D; abnormalities in bone turnover, mineralization, volume, or strength; extra-skeletal calcifications, such as vascular or other soft tissue. CKD-MBD syndrome determines relevant consequences in terms of fragility fractures, cardiovascular events and higher mortality. The nephrologist's awareness of CKD-MBD diagnostic and management tools and therapeutic strategies is key to improving CKD patients’ prognosis and outcomes. Method A new national survey (composed of 17 online questions) was conducted among Italian nephrologists to investigate the reference laboratory availability of bone turnover markers (BTMs), the clinical attitude on secondary hyperparathyroidism (sHPT) management, and the CKD-MBD therapeutic approach in different stages of CKD and dialysis patients. Results 89 Italian nephrologists participated in the survey. The reference laboratories largely fulfill the biomarkers request of ionized calcium (97.7%), phosphorus (100%), PTH (100%), alkaline phosphatase (ALP) (100%), magnesium (100%), 25-OH and 1,25-OH vitamin D levels (92.1%; 53.9%); while most of the hospital laboratories do not regularly support the availability of specific BTMs, both for diagnosis and monitoring the bone resorption and formation (Fig. 1)—such as bone ALP (75.3%), calcifediol (37.1%), calcitriol (40.5%), fibroblast growth factor-23 (FGF-23) (intact 9% and c-terminal 4.5%), vitamin K (33.7%), Klotho (6.75%, soluble 4.5%), osteocalcin (38.2%), matrix gla protein (10.1%), tartrate-resistant acid phosphatase 5b (TRAP-5b) (6.75%), cross-linked collagen type I peptide (CTX) (32.6%) and procollagen type 1 n-terminal propeptide (P1NP) (10.1%). The nephrologist's attitude to start management and treatment of sHPT is revealed to be mainly led by KDOQI (n = 42, 47%) and KDIGO (n = 39, 44%) guidelines considering their PTH cut-off values; in 53.9% of clinicians the measure of PTH levels is then performed every 3 months according to KDOQI guidelines. In relation to the definition of high turnover metabolic bone disease by BTMs, this metabolic pattern is identified in &amp;gt; 50% and 30-40% of patients with CKD 4-5D by 31.5% and 21.4% of nephrologists, respectively. 65% of clinicians currently considered ALP of equal importance as alterations of PTH as a predictor of fracture events. Other biomarkers, such as FGF-23, P1NP or TRAP-5b, emerge to not be still used in regular clinical practice. In patients diagnosed with CKD-MBD and skeletal fragility, 76.4% of nephrologists consider the AIFA (Italian Medicines Agency) note 79 to support osteoporosis treatment. The therapeutic strategies of CKD-MBD include the administration of vitamin D (e.g. cholecalciferol 27-37.1%, calcifediol 9-12.4%, calcitriol 42.7-55.1%) and its analogues (e.g. paricalcitol 23.6-52.8%) and the use of antiresorptive agents (e.g. alendronate 3.4%-23.6%, denosumab 22.5%-30.3%) with variable frequencies among different advanced CKD stages and for those patients on peritoneal or hemodialysis (Fig. 2). Conclusion Results present a suboptimal use of BTMs and a current heterogeneous therapeutic management of CKD-MBD syndrome and renal osteodystrophy in Italian clinical practice. The survey represents a starting point of work to further implement awareness of diagnostic and therapeutic issues of CKD-MBD.

An adaptive biodegradable zinc alloy with bidirectional regulation of bone homeostasis for treating fractures and aged bone defects

Healing of fractures or bone defects is significantly hindered by overactivated osteoclasts and inhibited osteogenesis in patients with abnormal bone metabolism. Current clinical approaches using titanium alloys or stainless steel provide mechanical support but have no biological effects on bone regeneration. Therefore, designing and fabricating degradable metal materials with sufficient mechanical strength and bidirectional regulation of both osteoblasts and osteoclasts is a substantial challenge. Here, this study first reported an adaptive biodegradable Zn-0.8 Mg alloy with bidirectional regulation of bone homeostasis, which promotes osteogenic differentiation by activating the Pi3k/Akt pathway and inhibits osteoclast differentiation by inhibiting the GRB2/ERK pathway. The anti-osteolytic ability of the Zn-0.8 Mg alloy was verified in a mouse calvarial osteolysis model and its suitability for internal fracture fixation with high-strength screws was confirmed in the rabbit femoral condyle fracture model. Furthermore, in an aged postmenopausal rat femoral condyle defect model, 3D printed Zn-0.8 Mg scaffolds promoted excellent bone regeneration through adaptive structures with good mechanical properties and bidirectionally regulated bone metabolism, enabling personalized bone defect repair. These findings demonstrate the substantial potential of the Zn-0.8 Mg alloy for treating fractures or bone defects in patients with aberrant bone metabolism.

Regulatory cellular and molecular networks in the bone microenvironment during aging

Abstract Age-induced abnormalities in bone metabolism disrupt the equilibrium between bone resorption and formation. This largely stems from disturbances in bone homeostasis, in which signaling pathways exert a significant regulatory influence. Aging compromises the functionality of the bone marrow mesenchymal stem cells (BMSCs), ultimately resulting in tissue dysfunction and pathological aging. Age-related bone degradation primarily manifests as reduced bone formation and the increased accumulation of bone marrow fat. Cellular senescence diminishes bone cell vitality, thereby disrupting the balance of bone remodeling. Intensive osteoclast differentiation leads to the generation of more osteoclasts and increased bone resorption. This review provides insight into the impact of aging on bone, encompassing bone cell states during the aging process and bone signaling pathway transformations. It primarily delves into aging-related signaling pathways, such as the bone morphogenetic protein/Smad, Wnt/β-catenin, osteoprotegerin/receptor activator of NF-κB ligand/receptor activator of NF-κB, connexin43/miR21, and nuclear factor erythroid 2-related factor 2/antioxidant response element pathways, seeking to enhance our comprehension of crucial bone cells and their secretory phenotypes during aging. Furthermore, the precise molecular regulatory mechanisms underlying the interactions between bone signaling pathways and aging are investigated.

Correlation of serum matrix metalloproteinase 3 with osteoporosis in patients of postmenopausal rheumatoid arthritis

Osteoporosis (OP) is a common complication of postmenopausal women with rheumatoid arthritis (RA). Herein, the objective of our study was to explore the correlation between serum matrix metalloproteinase 3 (MMP3) and OP among postmenopausal women with RA to foster better diagnosis and treatment. A total of 208 elderly postmenopausal women with RA were included in this study, with 83 patients diagnosed with OP after RA diagnosis and 125 patients without OP. Serum MMP3 levels and bone mineral density (BMD) were measured and compared. The predictive value of serum MMP3 for OP in this population was also analyzed using receiver operating curve (ROC) analysis. Postmenopausal women with RA and OP diagnosis had markedly higher serum MMP3 levels, compared to those without OP. ROC analysis showed that serum MMP3 had predictive value for OP. Additionally, a negative correlation was observed between serum MMP3 levels and BMD. High serum MMP3 levels were also found to be associated with high abnormal bone metabolism. We found that serum MMP3 levels are strongly correlated with OP in postmenopausal women with RA and that elevated levels of serum MMP3 are linked to low BMD and high abnormal bone metabolism. Serum MMP3 may be a useful biomarker for predicting OP in this population, and could potentially aid in the development of targeted prevention and treatment strategies.

Endocrine features of Prader-Willi syndrome: a narrative review focusing on genotype-phenotype correlation.

Prader-Willi syndrome (PWS) is a complex genetic disorder caused by three different types of molecular genetic abnormalities. The most common defect is a deletion on the paternal 15q11-q13 chromosome, which is seen in about 60% of individuals. The next most common abnormality is maternal disomy 15, found in around 35% of cases, and a defect in the imprinting center that controls the activity of certain genes on chromosome 15, seen in 1-3% of cases. Individuals with PWS typically experience issues with the hypothalamic-pituitary axis, leading to excessive hunger (hyperphagia), severe obesity, various endocrine disorders, and intellectual disability. Differences in physical and behavioral characteristics between patients with PWS due to deletion versus those with maternal disomy are discussed in literature. Patients with maternal disomy tend to have more frequent neurodevelopmental problems, such as autistic traits and behavioral issues, and generally have higher IQ levels compared to those with deletion of the critical PWS region. This has led us to review the pertinent literature to investigate the possibility of establishing connections between the genetic abnormalities and the endocrine disorders experienced by PWS patients, in order to develop more targeted diagnostic and treatment protocols. In this review, we will review the current state of clinical studies focusing on endocrine disorders in individuals with PWS patients, with a specific focus on the various genetic causes. We will look at topics such as neonatal anthropometry, thyroid issues, adrenal problems, hypogonadism, bone metabolism abnormalities, metabolic syndrome resulting from severe obesity caused by hyperphagia, deficiencies in the GH/IGF-1 axis, and the corresponding responses to treatment.