Odontologia e osteoporose: uma revisão narrativa / Dentistry and osteoporosis: a narrative review

A osteoporose é caracterizada pela perda óssea e pelo comprometimento da resistência do osso. Essa patologia afeta, também, os ossos da face e consequentemente interfere na atuação dos profissionais da odontologia. Assim sendo, o presente trabalho revisou a literatura acerca da relação entre osteoporose e odontologia. O levantamento dos dados se deu por consulta a livros e nas bases de dados Biblioteca Virtual em Saúde (BVS), PubMed e Scientific Eletronic Library Online (SciELO) e como Descritores em Ciência da Saúde (Decs) foram adotados os termos: "Odontologia", "Osteoporose" e "Saúde bucal". A osteoporose diminui a massa e aumenta a porosidade óssea na maxila e na mandíbula, podendo provocar até quatro vezes mais perda dentária. Os bifosfonatos, principal classe medicamentosa utilizada para o tratamento de osteoporose, estão associados à ocorrência de osteonecrose dos maxilares e ao aumento de tempo de tratamento ortodôntico. Assim, pode-se concluir que é imprescindível o conhecimento do cirurgião-dentista acerca da osteoporose para uma segura abordagem e execução de tratamento.

Osteoporosis is characterized by bone loss and compromised bone strength. This pathology also affects the bones of the face and consequently interferes with the work of dentists. Therefore, the present study reviewed the literature about the relationship between osteoporosis and dentistry. Data collection was carried out by consulting books and the databases Biblioteca Virtual em Saúde (BVS), PubMed and Scientific Electronic Library Online (SciELO) and as Medical Subjects Headings (MeSH) the terms adopted were: "Dentistry", "Osteoporosis" and "Oral health". Osteoporosis reduces bone mass and increases bone porosity in the maxilla and jaw, which can cause up to four times more tooth loss. Bisphosphonates, the main class of medications used to treat osteoporosis, are associated with the occurrence of osteonecrosis of the jaw (ONJ) and increase the time of orthodontic treatment. Thus, it can be concluded that the dentist's knowledge of osteoporosis is necessary for a safe approach and execution of treatment.

Deciphering Osteosarcopenia through the hallmarks of aging.

Osteosarcopenia is a major driver of functional loss and a risk factor for falls, fractures, disability and mortality in older adults, urgently requiring the development of effective interventions to address it. The hallmarks of aging provide a theoretical and practical framework that allows for the structured organization of current knowledge and the planning of new development lines. This article comprehensively reviews the currently available literature on the role of the hallmarks of aging in the development of osteosarcopenia, thereby offering a panoramic view of the state of the art and knowledge gaps in this field.

Strontium-containing mineralized phospholipid coatings improve osseointegration in osteoporotic rats.

Surface treatments play an important role in enhancing the osseointegration of Titanium (Ti) and its alloys. This study introduces a method employing biomimetic hydroxyapatite (Hap) deposition guided by molecularly organized phospholipids, affixed to the metal implant surface. Using the Langmuir-Blodgett technique, phospholipids were deposited onto Ti-screws by using CaCl2 or CaCl2/SrCl2 aqueous solution in the subphase of a Langmuir trough in the target proportion (i.e. 10 and 90 mol% of Sr2+ in relation of Ca2+) followed by immersion in phosphate buffer and in supersaturated simulated body fluid. Coating composition and morphology were evaluated using infrared spectroscopy and scanning electron microscopy, respectively, while contact angle measurements assessed coating wettability and surface energy. Randomized screws were then implanted into the tibias of healthy and osteoporotic female rats (G1: Control-Machined, G2: Hap, G3: HapSr10, G4: HapSr90). Osseointegration, assessed 60 days post-implantation, included reverse torque, fluorochrome area, bone tissue-screw contact area, and linear extent of bone-screw contact. Results, grouped by surface treatment (Machined, Hap, HapSr10, HapSr90), revealed that the deposition of Hap, HapSr10, and HapSr90 resulted in thin and rough coatings composed of hydroxyapatite (Hap) on the screw surface with nanoscale pores. The coatings resulted in increased wettability and surface energy of Ti surfaces. The minerals are chemically similar to natural bone apatite as revealed by FTIR analysis. In vivo analyses indicated higher torque values for strontium-containing surfaces in the osteoporotic group (p = 0.02) and, in the control group superior torque for screw removal on the Hap surface (p = 0.023). Hydroxyapatite-treated surfaces enhance morphology, composition, and reactivity, promoting screw osseointegration in healthy and osteoporotic female rats. The incorporation of strontium into the mineral phase has been proposed to not only stimulate osteoblast activity but also reduce osteoclastic resorption, which may explain the improved outcomes observed here in experimental osteoporotic conditions.

Osteoporosis and Fragility Fractures in Mexico: A Call to Action.

Osteoporosis (OP) is a chronic disease that affects older adults' quality of life, with fragility fractures (FF) being its most significant consequence due to their impact on healthcare systems in terms of morbidity, and economic and caregiving burden. FF are defined as fractures resulting from low-energy trauma, defined as falls from a standing height or less, and are usually considered osteoporotic (1). World demographic projections warn of a significant increase in adults aged 65 and older by 2050. These demographic changes mean that OP and FF will soon become an even greater challenge for healthcare systems, where prevention programs should be a priority. In Mexico, FF is also a public health challenge, with an initial reported incidence of nearly 2,000 cases per 100,000 population, and a projected seven-fold increase by 2050. Given this scenario, there is an urgent need for policy- and decision-makers to change their approach and formulate health policies that guarantee that people aged 65 and older are screened for fractures and have access to appropriate care. These policies should be part of a strategy to minimize FF and ensure active and healthy aging according to the WHO's Decade of Healthy Ageing. In this context, a group of Mexican experts representing different health organizations interested in the burden of OP and FF met to discuss possible strategies to reduce their burden for the next decade and summarize them in this Call to Action to promote public policies that prioritize an evidence-based approach to the prevention and treatment of OP and FF.

Effects of Cannabidiol on Bone Quality in Ovariectomized Rats.

The incidence of osteoporosis and related fractures increases significantly with age, impacting public health and associated costs. Postmenopausal osteoporosis results from increased bone resorption due to decreased estrogen levels. The endocannabinoid system, especially cannabidiol (CBD), has shown therapeutic potential in modulating bone formation. This study investigated the effects of administration of CBD in rats after the onset of with ovariectomy-induced osteopenia (OVX). Forty-eight female Sprague‒Dawley rats were divided into four groups (n = 12): OVX + CBD, SHAM + CBD, OVX + vehicle, and SHAM + vehicle. CBD was administered intraperitoneally for 3 weeks. After euthanasia, the bone quality, mechanical properties, and bone microarchitecture of the femurs and lumbar vertebrae were assessed by microcomputed tomography (micro-CT), bone densitometry, mechanical tests, and histological and immunohistochemical analyses. CBD treatment improved the bone mineral density (BMD) of the lumbar vertebrae and increased the BV/TV% and Tb.N in the femoral neck. There were also improvements in the mechanical properties, such as the maximum force and stiffness of the femurs and vertebrae. CBD significantly increased the bone matrix in osteopenic femurs and vertebrae, Although did not significantly influence the expression of RANKL and OPG, in ovariectomized animals, there was an increase in osteoblasts and a decrease in osteoclasts. Determining the optimal timing for CBD use in relation to postovariectomy bone loss remains a crucial issue. Understanding when and how CBD can be most effective in preventing or treating bone loss is essential to emphasize the importance of early diagnosis and treatment of osteoporosis. However, further studies are needed to explore in more detail the efficacy and safety of CBD in the treatment of postmenopausal osteoporosis.

Prevalence of fractures in adults over 50 years of age with osteoporosis in Colombia.

What are the fractures associated with osteoporosis in Colombian persons over 50 years of age? Through the analysis of the Ministry of Health databases, Colombians over 50 years of age with osteoporosis fracture the forearm the most, followed by the thoracolumbar vertebrae and then the hip. We describe the differences between men and women. PURPOSE: The aim of this study was to determine the frequency of all bone fractures among adults aged 50 and above, both with and without osteoporosis, using data from SISPRO (Integrated Information System for Social Protection), the administrative database of the Colombian Ministry of Health. METHODS: Information was collected for the years 2017 to 2021 for all bone fractures (except cranial or face fractures), and how many of them occurred in patients who had the diagnosis of osteoporosis. Prevalence ratios (PR) were estimated separately for males and females by dividing the prevalence in those with by the prevalence of those without osteoporosis. RESULTS: For the period from 2017 to 2021, 303,037 adults over 50 years of age (females 279,057, 92.1%) were diagnosed with osteoporosis in Colombia, for a prevalence of 39.4 per thousand women and 4.14 in men; 40,823 of these women (14.6%) presented a fracture in the period, as well as 4020 of men (16.7%). Osteoporosis was present in 7.5% of the 596.618 (females 369.795; 62.0%) who suffered any fracture (1.8% of males and 11.0% of females). Overall PR was 3.4 (males 4.3; females 3.3). In men with osteoporosis, the most frequent fractures were hip (902), followed by lumbar vertebrae (842), ribs (648), and forearm (538), while in women, forearm (11,001), followed by hip (6885), lumbar vertebra (4813), and thoracic vertebra (2701) were the most common. PR in men was 21.9 for dorsal vertebrae fracture, 21.3 for lumbar vertebrae, 11.8 for ribs, and 7.7 for hip fracture. In women, PR was 15.7 for thoracic vertebrae, 13.3 for lumbar vertebrae, 3.3 for hip fracture, and 2.2 for forearm fracture. CONCLUSION: Osteoporosis is a highly prevalent disease in Colombia where women are more affected. Although fractures were more common in women, men with osteoporosis have a higher PR of associated fractures.

In Vivo Effects of Biosilica and Spongin-Like Collagen Scaffolds on the Healing Process in Osteoporotic Rats.

Due to bioactive properties, introducing spongin-like collagen (SPG) into the biosilica (BS) extracted from marine sponges would present an enhanced biological material for improving osteoporotic fracture healing by increasing bone formation rate. Our aim was to characterize the morphology of the BS/SPG scaffolds by scanning electron microscopy (SEM), the chemical bonds of the material by Fourier transform infrared spectroscopy (FTIR), and evaluating the orthotopic in vivo response of BS/SPG scaffolds in tibial defects of osteoporotic fractures in rats (histology, histomorphometry, and immunohistochemistry) in two experimental periods (15 and 30 days). SEM showed that scaffolds were porous, showing the spicules of BS and fibrous aspect of SPG. FTIR showed characteristic peaks of BS and SPG. For the in vivo studies, after 30 days, BS and BS/SPG showed a higher amount of newly formed bone compared to the first experimental period, observed both in the periphery and in the central region of the bone defect. For histomorphometry, BS/SPG presented higher %BV/TV compared to the other experimental groups. After 15 days, BS presented higher volumes of collagen type I. After 30 days, all groups demonstrated higher volumes of collagen type III compared to volumes at 15 days. After 30 days, BS/SPG presented higher immunostaining of osteoprotegerin compared to the other experimental groups at the same experimental period. The results showed that BS and BS/SPG scaffolds were able to improve bone healing. Future research should focus on the effects of BS/SPG on longer periods in vivo studies.

Effects of Selective and Nonselective Beta Blockers on Bone Mineral Density in Mexican Patients with Breast Cancer.

Breast cancer (BCa) is related to chronic stress and can reduce the bone mineral density (BMD) through neurochemicals related to beta-adrenergic receptor (ADRB) 1 and 2. Selective beta blockers (sBBs) and nonselective beta blockers (nsBBs) are used to treat systemic arterial hypertension (SAH) and may have osteoprotective effects, as they inhibit ADRBs. To evaluate the effects of sBBs and nsBBs on the BMD of Mexican patients with BCa. A retrospective study was conducted. We included 191 Mexican women with BCa without SAH and with SAH treated with nsBBs, sBBs, and diuretics. BMD was evaluated using a bone density scan (DEX scan). A greater average BMD (p < 0.05) was observed in patients with prior treatment with both nsBBs and sBBs (0.54 ± 0.94 and -0.44 ± 1.22, respectively) compared to patients treated with diuretics or without SAH (-1.73 ± 0.83 and -1.22 ± 0.98, respectively). Regarding the diagnosis of osteoporosis/osteopenia, no cases were observed in patients treated with nsBBs, whereas 5.6% of the patients treated with sBBs presented osteopenia. A total of 23.1% and 10.6% patients managed with diuretics or without treatment presented with osteoporosis and 61.5% and 48% patients managed with loop diuretics and without treatment presented with osteopenia, respectively (p < 0.05). Treatment with nsBBs is a promising option for the prevention and management of osteoporosis/osteopenia in Mexican patients with BCa; however, further prospective studies are needed.

Smart Delivery of Biomolecules Interfering with Peri-Implant Repair in Osteoporotic Rats.

Bisphosphonates are widely used for the treatment of postmenopausal osteoporosis; however, they cause several long-term side effects, necessitating the investigation of local ways to improve osseointegration in compromised bone tissue. The purpose of this study was to evaluate peri-implant bone repair using implants functionalized with zoledronic acid alone (OVX ZOL group, n = 11), zoledronic acid + teriparatide (OVX ZOL + TERI group, n = 11), and zoledronic acid + ruterpy (OVX ZOL + TERPY group, n = 11) compared to the control group (OVX CONV, n = 11). Analyses included computer-assisted microtomography, qualitative histologic analysis, and real-time PCR analysis. Histologically, all functionalized surfaces improved peri-implant repair, with the OVX ZOL + TERI group standing out. Similar results were found in computerized microtomography analysis. In real-time PCR analysis, however, the OVX ZOL and OVX ZOL + TERPY groups showed better results for bone formation, with the OVX ZOL + TERPY group standing out, while there were no statistical differences between the OVX CONV and OVX ZOL + TERI groups for the genes studied at 28 postoperative days. Nevertheless, all functionalized groups showed a reduced rate of bone resorption. In short, all surface functionalization groups outperformed the control group, with overall better results for the OVX ZOL + TERI group.

MicroRNAs and their Modulatory Effect on the Hallmarks of Osteosarcopenia.

PURPOSE OF THE REVIEW: Osteosarcopenia is a geriatric syndrome associated with disability and mortality. This review summarizes the key microRNAs that regulate the hallmarks of sarcopenia and osteoporosis. Our objective was to identify components similarly regulated in the pathology and have therapeutic potential by influencing crucial cellular processes in both bone and skeletal muscle. RECENT FINDINGS: The simultaneous decline in bone and muscle in osteosarcopenia involves a complex crosstalk between these tissues. Recent studies have uncovered several key mechanisms underlying this condition, including the disruption of cellular signaling pathways that regulate bone remodeling and muscle function and regeneration. Accordingly, emerging evidence reveals that dysregulation of microRNAs plays a significant role in the development of each of these hallmarks of osteosarcopenia. Although the recent recognition of osteosarcopenia as a single diagnosis of bone and muscle deterioration has provided new insights into the mechanisms of these underlying age-related diseases, several knowledge gaps have emerged, and a deeper understanding of the role of common microRNAs is still required. In this study, we summarize current evidence on the roles of microRNAs in the pathogenesis of osteosarcopenia and identify potential microRNA targets for treating this condition. Among these, microRNAs-29b and -128 are upregulated in the disease and exert adverse effects by inhibiting IGF-1 and SIRT1, making them potential targets for developing inhibitors of their activity. MicroRNA-21 is closely associated with the occurrence of muscle and bone loss. Conversely, microRNA-199b is downregulated in the disease, and its reduced activity may be related to increased myostatin and GSK3ß activity, presenting it as a target for developing analogues that restore its function. Finally, microRNA-672 stands out for its ability to protect skeletal muscle and bone when expressed in the disease, highlighting its potential as a possible therapy for osteosarcopenia.

Monoclonal antibodies in patients with osteoporosis and renal insufficiency: An updated systematic review and meta-analysis.

Objectives: There are challenges for the treatment of osteoporosis in patients with kidney failure and monoclonal antibodies (MAb) might be a suitable therapy. However, the efficacy and safety of MAb among patients with osteoporosis and renal insufficiency remains unclear. Methods: We systematically searched PubMed, Embase, and Cochrane Central for studies evaluating the efficacy and safety of the use of MAb in patients with osteoporosis and renal insufficiency. We pooled risk ratios (RR) and 95% confidence intervals (CI) for binary outcomes. Mean difference (MD) was used for continuous outcomes. Results: We included 5 studies with 33,550 patients. MAb therapy decreased the risk of vertebral fractures (RR 0.32; 95% CI 0.26-0.40; P < 0.01) when compared to placebo and no statistical difference was found when comparing to bisphosphonate (RR 0.71; 95% CI 0.49-1.03; P = 0.07). MAb therapy also decreased the risk of nonvertebral fractures (RR 0.79; 95% CI 0.69-0.91; P = 0.0009). Lumbar spine bone mineral density (BMD) was higher in the MAb therapy when compared to both placebo (MD 10.90; 95% CI 8.00-13.80; P < 0.01) and bisphosphonate (MD 7.66; 95% CI 6.19-9.14; P < 0.01). There was no statistically significant difference in the change of estimated glomerular filtration rate and in the incidence of hypocalcemia and serious adverse events between groups. Conclusions: There were reductions in both vertebral and nonvertebral fracture risks, alongside improvements in BMD among patients with renal insufficiency treated with MAb.

Performance of the Brazilian Fracture Assessment Risk Tool (FRAX) model and the age-dependent intervention thresholds according to National Osteoporosis Guideline Group (NOGG) guidelines on fracture prediction in community-dwelling older adults: the São Paulo Ageing and Health (SPAH) Study.

The SPAH study is a population-based prospective cohort of Brazilian community-dwelling elderlies with higher fracture risk than observed in the studies used to construct the Brazilian FRAX model. In this study, the FRAX tool was a good fracture predictor within this high-risk elderly cohort, especially when calculated without bone density. PURPOSE: To determine the performances of FRAX and age-dependent intervention thresholds according to National Osteoporosis Guideline Group (NOGG) guidelines with and without bone mineral density (BMD) regarding fracture prediction in community-dwelling elderly Brazilians. METHODS: Seven hundred and five older adults (447 women; 258 men) were followed for 4.3 ± 0.8 years. FRAX risk for hip and major osteoporotic fractures with and without BMD was calculated at baseline. The bivariate analysis investigated the associations between the absolute probability of fracture (FRAX), as well as the age-dependent intervention thresholds (NOGG), and the incidence of vertebral fracture (VF), non-vertebral fracture (NVF), and major osteoporotic fractures (MOF), segregated by sex. Age-adjusted Poisson's multiple regression and ROC curves were constructed to determine FRAX and NOGG's accuracies as fracture predictors. RESULTS: Fractures occurred in 22% of women and 15% of men. FRAX with and without BMD was higher in women with all types of fractures (p < 0.001). Only NOGG risk classification without BMD was associated with NVF (p = 0.047) and MOF (p = 0.024). FRAX was associated with NVF in the multiple regression, regardless of BMD. ROC curves of FRAX with and without BMD had AUCs of 0.74, 0.64, and 0.61 for NVF, VF, and MOF, respectively. The most accurate risk cutoffs for FRAX were 8% for MOF and 3% for hip fractures. No statistically significant associations were found in men. CONCLUSION: FRAX predicted NVF more accurately than VF or MOF in elderlies, regardless of BMD. These results reiterate that FRAX may be used without BMD, even considering that Brazilian elderlies have known higher fracture risk.

Accuracy of an artificial intelligence algorithm for detecting moderate-to-severe vertebral compression fractures on abdominal and thoracic computed tomography scans.

Objective: To describe the accuracy of HealthVCF, a software product that uses artificial intelligence, in the detection of incidental moderate-to-severe vertebral compression fractures (VCFs) on chest and abdominal computed tomography scans. Materials and Methods: We included a consecutive sample of 899 chest and abdominal computed tomography scans of patients 51-99 years of age. Scans were retrospectively evaluated by the software and by two specialists in musculoskeletal imaging for the presence of VCFs with vertebral body height loss > 25%. We compared the software analysis with that of a general radiologist, using the evaluation of the two specialists as the reference. Results: The software showed a diagnostic accuracy of 89.6% (95% CI: 87.4-91.5%) for moderate-to-severe VCFs, with a sensitivity of 73.8%, a specificity of 92.7%, and a negative predictive value of 94.8%. Among the 145 positive scans detected by the software, the general radiologist failed to report the fractures in 62 (42.8%), and the algorithm detected additional fractures in 38 of those scans. Conclusion: The software has good accuracy for the detection of moderate-to-severe VCFs, with high specificity, and can increase the opportunistic detection rate of VCFs by radiologists who do not specialize in musculoskeletal imaging.

Objetivo: Descrever a acurácia do software HealthVCF na detecção incidental de fraturas compressivas de corpos vertebrais moderadas a graves em exames de tomografia computadorizada do tórax e abdome. Materiais e Métodos: Foram incluídos 899 exames consecutivos de pacientes com idades entre 51 e 99 anos. As imagens foram retrospectivamente avaliadas pelo software e por dois radiologistas especializados em musculoesquelético que investigaram fraturas compressivas de corpos vertebrais com perda da altura somática > 25%. A análise comparativa foi realizada entre o software e um radiologista geral, usando a avaliação do especialista como referência. Resultados: O software apresentou uma acurácia de 89,6% (IC 95%: 87,4­91,5%) para fraturas compressivas moderadas a graves, com sensibilidade de 73,8%, especificidade de 92,7% e valor preditivo negativo de 94,8%. Entre as 145 tomografias positivas detectadas pelo software, o radiologista geral deixou de relatar as fraturas em 62 (42,8%) e o algoritmo detectou fraturas adicionais em 38 dessas tomografias. Conclusão: O software possui boa acurácia na detecção de fraturas compressivas moderadas a graves, com alta especificidade, podendo aumentar a taxa de detecção oportunística dessas fraturas por radiologistas não especializados em musculoesquelético.

The multiple actions of dipeptidyl peptidase 4 (DPP-4) and its pharmacological inhibition on bone metabolism: a review.

BACKGROUND: Dipeptidyl peptidase 4 (DPP-4) plays a crucial role in breaking down various substrates. It also has effects on the insulin signaling pathway, contributing to insulin resistance, and involvement in inflammatory processes like obesity and type 2 diabetes mellitus. Emerging effects of DPP-4 on bone metabolism include an inverse relationship between DPP-4 activity levels and bone mineral density, along with an increased risk of fractures. MAIN BODY: The influence of DPP-4 on bone metabolism occurs through two axes. The entero-endocrine-osseous axis involves gastrointestinal substrates for DPP-4, including glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptides 1 (GLP-1) and 2 (GLP-2). Studies suggest that supraphysiological doses of exogenous GLP-2 has a significant inhibitory effect on bone resorption, however the specific mechanism by which GLP-2 influences bone metabolism remains unknown. Of these, GIP stands out for its role in bone formation. Other gastrointestinal DPP-4 substrates are pancreatic peptide YY and neuropeptide Y-both bind to the same receptors and appear to increase bone resorption and decrease bone formation. Adipokines (e.g., leptin and adiponectin) are regulated by DPP-4 and may influence bone remodeling and energy metabolism in a paracrine manner. The pancreatic-endocrine-osseous axis involves a potential link between DPP-4, bone, and energy metabolism through the receptor activator of nuclear factor kappa B ligand (RANKL), which induces DPP-4 expression in osteoclasts, leading to decreased GLP-1 levels and increased blood glucose levels. Inhibitors of DPP-4 participate in the pancreatic-endocrine-osseous axis by increasing endogenous GLP-1. In addition to their glycemic effects, DPP-4 inhibitors have the potential to decrease bone resorption, increase bone formation, and reduce the incidence of osteoporosis and fractures. Still, many questions on the interactions between DPP-4 and bone remain unanswered, particularly regarding the effects of DPP-4 inhibition on the skeleton of older individuals. CONCLUSION: The elucidation of the intricate interactions and impact of DPP-4 on bone is paramount for a proper understanding of the body's mechanisms in regulating bone homeostasis and responses to internal stimuli. This understanding bears significant implications in the investigation of conditions like osteoporosis, in which disruptions to these signaling pathways occur. Further research is essential to uncover the full extent of DPP-4's effects on bone metabolism and energy regulation, paving the way for novel therapeutic interventions targeting these pathways, particularly in older individuals.

The Involvement of microRNAs in Bone Remodeling Signaling Pathways and Their Role in the Development of Osteoporosis.

Bone remodeling, crucial for maintaining the balance between bone resorption and formation, relies on the coordinated activity of osteoclasts and osteoblasts. During osteoclastogenesis, hematopoietic stem cells (HSCs) differentiate into the osteoclast lineage through the signaling pathways OPG/RANK/RANKL. On the other hand, during osteoblastogenesis, mesenchymal stem cells (MSCs) differentiate into the osteoblast lineage through activation of the signaling pathways TGF-ß/BMP/Wnt. Recent studies have shown that bone remodeling is regulated by post-transcriptional mechanisms including microRNAs (miRNAs). miRNAs are small, single-stranded, noncoding RNAs approximately 22 nucleotides in length. miRNAs can regulate virtually all cellular processes through binding to miRNA-response elements (MRE) at the 3' untranslated region (3'UTR) of the target mRNA. miRNAs are involved in controlling gene expression during osteogenic differentiation through the regulation of key signaling cascades during bone formation and resorption. Alterations of miRNA expression could favor the development of bone disorders, including osteoporosis. This review provides a general description of the miRNAs involved in bone remodeling and their significance in osteoporosis development.

Jaboticaba Peel Extract Attenuates Ovariectomy-Induced Bone Loss by Preserving Osteoblast Activity.

Therapies to prevent osteoporosis are relevant since it is one of the most common non-communicable human diseases in the world and the most prevalent bone disorder in adults. Since jaboticaba peel extract (JPE) added to the culture medium enhanced the osteogenic potential of mesenchymal stem cells (MSCs) derived from osteoporotic rats, we hypothesized that JPE prevents the development of ovariectomy-induced osteoporosis. Ovariectomized rats were treated with either JPE (30 mg/kg of body weight) or its vehicle for 90 days, starting 7 days after the ovariectomy. Then, the femurs were subjected to microcomputed tomography and histological analyses, and the osteoblast and adipocyte differentiation of MSCs was evaluated. JPE attenuated ovariectomy-induced bone loss, as evidenced by higher bone volume/total volume and trabecular number, along with lower trabecular separation and bone marrow adiposity. These protective effects of JPE on bone tissue are due to its ability to prevent the imbalance between osteoblast and adipocyte differentiation of MSCs, since, compared with MSCs derived from ovariectomized rats treated with vehicle, MSCs treated with JPE exhibited higher gene and protein expression of osteogenic markers and extracellular matrix mineralization, as well as lower gene expression of adipogenic markers. These data highlight the potential therapeutic use of JPE to prevent osteoporosis.

Atypical Metatarsal Fractures: Report of Five Clinical Cases.

Atypical fractures are well elucidated when they occur in the femur and are related to the use of bisphosphonates. Prolonged therapy with this drug leads to excessive suppression of bone remodeling, which makes the bone more brittle. In general, they are caused by minimal trauma or are atraumatic. This type of fracture is also reported in other bony sites, such as the metatarsus. Some reports and studies on atypical metatarsal fractures have been published, but further investigations are required to better understand this type of fracture and establish the proper diagnosis, treatment and conduct. The present study is a report of five cases of patients who presented metatarsal fractures during therapy with bisphosphonates. All patients were female, had osteoporosis as a preexisting disease, were taking bisphosphonates, presented fractures that were either atraumatic or caused by minimal trauma, and the imaging examination showed a transverse meta-diaphyseal fracture of the fifth metatarsal shaft with thickening of the lateral cortex, image characteristics similar to the criteria used by the American Society for Bone and Mineral Research (ASMBR) to define atypical femur fractures.

Osteoporosis and Alzheimer´s disease (or Alzheimer´s disease and Osteoporosis).

Alzheimer's disease (AD) and osteoporosis are two diseases that mainly affect elderly people, with increases in the occurrence of cases due to a longer life expectancy. Several epidemiological studies have shown a reciprocal association between both diseases, finding an increase in incidence of osteoporosis in patients with AD, and a higher burden of AD in osteoporotic patients. This epidemiological relationship has motivated the search for molecules, genes, signaling pathways and mechanisms that are related to both pathologies. The mechanisms found in these studies can serve to improve treatments and establish better patient care protocols.

Thyroid dysgenesis associated with dwarfism, osteoporosis and spontaneous fractures in a goat.

An 11-month-old female Saanen goat, weighing 12.7 kg, was taken to the Veterinary Hospital of the Federal University of Minas Gerais because of sternal recumbency. On clinical examination, the animal was much smaller than expected and had hair similar to that of puppies and areas of hyperpigmentation on the head and dorsocervical and dorsothoracic cranial regions. Radiographic examination revealed fractures in both femurs and severe generalized osteoporosis. Given the unfavourable prognosis, the animal was euthanized. Necropsy revealed generalized pallor, muscular atrophy of the pelvic limbs and little reserve of subcutaneous adipose tissue. Both femurs had complete and closed diaphyseal fractures. The second lumbar vertebra was severely reduced in length as a result of a fracture, with dorsal displacement of the vertebral body towards the vertebral canal and compression of the spinal cord. Long bones and vertebrae had severe cortical thinning, enlargement of the medullary canal and reduced resistance. The thyroid gland was not in its normal anatomical location. A pale red nodule (1.0 × 0.4 cm) in the serosa of the middle third of the trachea, close to the thoracic entrance, was confirmed as ectopic thyroid tissue. Microscopically, the bones had evidence of growth arrest and severe osteoporosis. The ectopic thyroid nodule was hyperplastic with severe hypertrophy of follicular cells. The spinal cord was compressed by vertebral fractures and had focally extensive and severe myelomalacia. Based on the pathological features, the case was diagnosed as thyroid dysgenesis characterized by eutopic thyroid agenesis and ectopic thyroid tissue, associated with interruption of bone growth with dwarfism, osteoporosis and spontaneous secondary fractures with compression of the lumbar spinal cord.

In vitro effects and mechanisms of Humulus lupulus extract on bone marrow progenitor cells and endothelial cells.

Osteoporosis is the most common metabolic bone disorder and is associated with a high incidence of fractures. Angiogenesis and adequate blood flow are important during bone repair and maintenance. Estrogens play a key role in bone formation, in the prevention of bone resorption and vasculature maintenance. Hormone replacement therapy (HRT) has been used with great benefits for bone fracture prevention but has been linked to the development of serious important side effects, including cancer and stroke. Phytoestrogens are an attractive alternative to HRT because their chemical structure is similar to estradiol but, they could behave as selective modulators: acting as antagonists of estrogen receptors in the breast and endometrium and as agonists in the vascular endothelium and bone. Hops contain a wide variety of phytoestrogens that have individually been shown to possess estrogenic activity by either blocking or mimicking. In this study we have to evaluate the in vitro effects and mechanisms of action of hops extracts on the osteogenic and adipogenic capacity of bone marrow progenitor cells (BMPCs), and the angiogenic potential of EA.hy926 endothelial cells. We show that hops extracts increase the proliferative capacity of BMPCs and promote their osteogenic differentiation while decreasing their pro-osteoclastogenic capacity; and that these effects are mediated by the MAPK pathway. Additionally, hops extracts prevent the adipogenic differentiation of BMPCs and promote endothelial cell activity, by mechanisms also partially mediated by MAPK.