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1.
Curr Osteoporos Rep ; 22(1): 115-121, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38227177

RESUMO

PURPOSE OF REVIEW: With the recent explosion in the use of artificial intelligence (AI) and specifically ChatGPT, we sought to determine whether ChatGPT could be used to assist in writing credible, peer-reviewed, scientific review articles. We also sought to assess, in a scientific study, the advantages and limitations of using ChatGPT for this purpose. To accomplish this, 3 topics of importance in musculoskeletal research were selected: (1) the intersection of Alzheimer's disease and bone; (2) the neural regulation of fracture healing; and (3) COVID-19 and musculoskeletal health. For each of these topics, 3 approaches to write manuscript drafts were undertaken: (1) human only; (2) ChatGPT only (AI-only); and (3) combination approach of #1 and #2 (AI-assisted). Articles were extensively fact checked and edited to ensure scientific quality, resulting in final manuscripts that were significantly different from the original drafts. Numerous parameters were measured throughout the process to quantitate advantages and disadvantages of approaches. RECENT FINDINGS: Overall, use of AI decreased the time spent to write the review article, but required more extensive fact checking. With the AI-only approach, up to 70% of the references cited were found to be inaccurate. Interestingly, the AI-assisted approach resulted in the highest similarity indices suggesting a higher likelihood of plagiarism. Finally, although the technology is rapidly changing, at the time of study, ChatGPT 4.0 had a cutoff date of September 2021 rendering identification of recent articles impossible. Therefore, all literature published past the cutoff date was manually provided to ChatGPT, rendering approaches #2 and #3 identical for contemporary citations. As a result, for the COVID-19 and musculoskeletal health topic, approach #2 was abandoned midstream due to the extensive overlap with approach #3. The main objective of this scientific study was to see whether AI could be used in a scientifically appropriate manner to improve the scientific writing process. Indeed, AI reduced the time for writing but had significant inaccuracies. The latter necessitates that AI cannot currently be used alone but could be used with careful oversight by humans to assist in writing scientific review articles.


Assuntos
Inteligência Artificial , COVID-19 , Humanos , Consolidação da Fratura , Redação
2.
Curr Osteoporos Rep ; 22(1): 177-181, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38225472

RESUMO

PURPOSE OF REVIEW: This Comment represents three review articles on the relationship between Alzheimer's disease, osteoporosis, and fracture in an exploration of the benefits that AI can provide in scientific writing. The first drafts of the articles were written (1) entirely by humans; (2) entirely by ChatGPT 4.0 (AI-only or AIO); and (3) by humans and ChatGPT 4.0 whereby humans selected literature references, but ChatGPT 4.0 completed the writing (AI-assisted or AIA). Importantly, each review article was edited and carefully checked for accuracy by all co-authors resulting in a final manuscript which was significantly different from the original draft. RECENT FINDINGS: The human-written article took the most time from start to finish, the AI-only article took the least time, and the AI-assisted article fell between the two. When comparing first drafts to final drafts, the AI-only and AI-assisted articles had higher percentages of different text than the human article. The AI-only paper had a higher percentage of incorrect references in the first draft than the AI-assisted paper. The first draft of the AI-assisted article had a higher similarity score than the other two articles when examined by plagiarism identification software. This writing experiment used time tracking, human editing, and comparison software to examine the benefits and risks of using AI to assist in scientific writing. It showed that while AI may reduce total writing time, hallucinations and plagiarism were prevalent issues with this method and human editing was still necessary to ensure accuracy.


Assuntos
Doença de Alzheimer , Fraturas Ósseas , Humanos , Idioma , Redação , Inteligência Artificial
3.
Curr Osteoporos Rep ; 22(1): 165-176, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38285083

RESUMO

PURPOSE OF REVIEW: This review examines the linked pathophysiology of Alzheimer's disease/related dementia (AD/ADRD) and bone disorders like osteoporosis. The emphasis is on "inflammaging"-a low-level inflammation common to both, and its implications in an aging population. RECENT FINDINGS: Aging intensifies both ADRD and bone deterioration. Notably, ADRD patients have a heightened fracture risk, impacting morbidity and mortality, though it is uncertain if fractures worsen ADRD. Therapeutically, agents targeting inflammation pathways, especially Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) and TNF-α, appear beneficial for both conditions. Additionally, treatments like Sirtuin 1 (SIRT-1), known for anti-inflammatory and neuroprotective properties, are gaining attention. The interconnectedness of AD/ADRD and bone health necessitates a unified treatment approach. By addressing shared mechanisms, we can potentially transform therapeutic strategies, enriching our understanding and refining care in our aging society. This review article is part of a series of multiple manuscripts designed to determine the utility of using artificial intelligence for writing scientific reviews.


Assuntos
Doença de Alzheimer , Demência , Humanos , Idoso , Doença de Alzheimer/epidemiologia , Doença de Alzheimer/terapia , Demência/epidemiologia , Demência/terapia , Inteligência Artificial , Densidade Óssea , Inflamação
4.
Curr Osteoporos Rep ; 22(1): 152-164, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38334917

RESUMO

PURPOSE OF REVIEW: This comprehensive review delves into the intricate interplay between Alzheimer's disease (AD) and osteoporosis, two prevalent conditions with significant implications for individuals' quality of life. The purpose is to explore their bidirectional association, underpinned by common pathological processes such as aging, genetic factors, inflammation, and estrogen deficiency. RECENT FINDINGS: Recent advances have shown promise in treating both Alzheimer's disease (AD) and osteoporosis by targeting disease-specific proteins and bone metabolism regulators. Monoclonal antibodies against beta-amyloid and tau for AD, as well as RANKL and sclerostin for osteoporosis, have displayed therapeutic potential. Additionally, ongoing research has identified neuroinflammatory genes shared between AD and osteoporosis, offering insight into the interconnected inflammatory mechanisms. This knowledge opens avenues for innovative dual-purpose therapies that could address both conditions, potentially revolutionizing treatment approaches for AD and osteoporosis simultaneously. This review underscores the potential for groundbreaking advancements in early diagnosis and treatment by unraveling the intricate connection between AD and bone health. It advocates for a holistic, patient-centered approach to medical care that considers both cognitive and bone health, ultimately aiming to enhance the overall well-being of individuals affected by these conditions. This review article is part of a series of multiple manuscripts designed to determine the utility of using artificial intelligence for writing scientific reviews.


Assuntos
Doença de Alzheimer , Osteoporose , Humanos , Doença de Alzheimer/terapia , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Inteligência Artificial , Qualidade de Vida , Peptídeos beta-Amiloides , Osteoporose/terapia
5.
Curr Osteoporos Rep ; 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38236512

RESUMO

PURPOSE OF REVIEW: This comprehensive review discusses the complex relationship between Alzheimer's disease (AD) and osteoporosis, two conditions that are prevalent in the aging population and result in adverse complications on quality of life. The purpose of this review is to succinctly elucidate the many commonalities between the two conditions, including shared pathways, inflammatory and oxidative mechanisms, and hormonal deficiencies. RECENT FINDINGS: AD and osteoporosis share many aspects of their respective disease-defining pathophysiology. These commonalities include amyloid beta deposition, the Wnt/ß-catenin signaling pathway, and estrogen deficiency. The shared mechanisms and risk factors associated with AD and osteoporosis result in a large percentage of patients that develop both diseases. Previous literature has established that the progression of AD increases the risk of sustaining a fracture. Recent findings demonstrate that the reverse may also be true, suggesting that a fracture early in the life course can predispose one to developing AD due to the activation of these shared mechanisms. The discovery of these commonalities further guides the development of novel therapeutics in which both conditions are targeted. This detailed review delves into the commonalities between AD and osteoporosis to uncover the shared players that bring these two seemingly unrelated conditions together. The discussion throughout this review ultimately posits that the occurrence of fractures and the mechanism behind fracture healing can predispose one to developing AD later on in life, similar to how AD patients are at an increased risk of developing fractures. By focusing on the shared mechanisms between AD and osteoporosis, one can better understand the conditions individually and as a unit, thus informing therapeutic approaches and further research. This review article is part of a series of multiple manuscripts designed to determine the utility of using artificial intelligence for writing scientific reviews.

6.
JBMR Plus ; 8(6): ziae054, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38784723

RESUMO

Low levels of microRNA (miR) 21 may explain the higher osteocyte apoptosis with Cx43-deficient and aged female mice. However, miR21 exerts a sex-divergent role in osteocytes, regulating bone mass and architecture through non-cell autonomous effects on osteoblasts and osteoclasts, via sex-specific regulation of osteocyte cytokine production. miR21 deficiency improves bone strength in females, and, to a higher extent, in male miR21-deficient mice. To understand the molecular basis for the effects of miR21 deletion, mRNA was isolated from miR21fl/fl (controls) or miR21-deficient (by deletion in cells expressing Cre recombinase under the control of the 8 kb fragment of the DMP1 promoter: miR21ΔOt mice). miR21 was 50% lower in miR21ΔOt whole calvaria bone compared to control mice of the corresponding sex. RNAseq was performed in 4 samples/sex and genotype. There were 152 genes with <.05 P-value and >1 absolute log2 fold change in the male data analysis, and expression of most genes was higher in the miR21fl/fl group. Two of the genes, Actn3 and Myh4, had a false discovery rate < 0.1. Gene enrichment analysis of significant genes on both KEGG pathways and gene ontology (GO) gene sets shows that the significant genes were enriched in muscle contraction. Some muscle-related genes like Actn3 were included in multiple significant pathways. For females, only 65 genes had P-value <.05 and >1 absolute log2 fold change. Yet, no significant KEGG or GO pathways, including ≥5 significant genes, were seen, and no overlap of significant genes was found between male and female samples. Therefore, deletion of miR21 has a stronger effect on male transcriptome in calvaria, compared to females. Further, no enrichment of any pathway was detected in female samples. Thus, either there are no differences between 2 groups in female or the effect size is small, and a larger sample size is needed to uncover miR21-dependent differences.

7.
J Bone Metab ; 31(2): 101-113, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38886968

RESUMO

BACKGROUND: Yerba mate (YM, Ilex paraguariensis) consumption beneficially affects the bones. However, whether YM components exert their effect on bone cells directly remains elusive. METHODS: We evaluated how main YM components affect osteoblastic (MC3T3-E1) and osteocytic (MLO-Y4) cells in vitro when administered separately or in an aqueous extract. MC3T3-E1 and MLO-Y4 cells were exposed to three different experimental conditions: (1) Caffeine, chlorogenic acid, and their combinations; (2) Caffeine, rutin, and their combinations; (3) Aqueous YM extract. RESULTS: All polyphenol and caffeine concentrations as well as that of their tested combinations significantly increased MC3T3-E1 cell viability from 16.6% to 34.8% compared to the control. In MLO-Y4 cells, the lowest rutin and the two highest caffeine concentrations significantly increased cell viability by 11.9, 14.9, and 13.7%, respectively. While rutin and caffeine combinations tended to increase MLO-Y4 cell viability, different chlorogenic acid and caffeine combinations did not affect it. Finally, the aqueous YM extract significantly increased MLO-Y4, MC3T3-E1, and differentiated MC3T3-E1 cell viability compared to the control without treatment. CONCLUSIONS: YM components (rutin, chlorogenic acid, and caffeine) positively affected bone cells, mainly pre-osteoblast cells. Moreover, the aqueous YM extract significantly increased MLO-Y4, MC3T3-E1, and differentiated MC3T3-E1 cell viabilities indicating an additional relevant nutritional property of YM infusion. Further studies would be required to elucidate the underlying effector mechanism of YM on the bones and its relationship with previously described in vivo positive effects.

8.
J Bone Miner Res ; 39(3): 298-314, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38477790

RESUMO

Osteocytes sense and respond to mechanical force by controlling the activity of other bone cells. However, the mechanisms by which osteocytes sense mechanical input and transmit biological signals remain unclear. Voltage-sensitive calcium channels (VSCCs) regulate calcium (Ca2+) influx in response to external stimuli. Inhibition or deletion of VSCCs impairs osteogenesis and skeletal responses to mechanical loading. VSCC activity is influenced by its auxiliary subunits, which bind the channel's α1 pore-forming subunit to alter intracellular Ca2+ concentrations. The α2δ1 auxiliary subunit associates with the pore-forming subunit via a glycosylphosphatidylinositol anchor and regulates the channel's calcium-gating kinetics. Knockdown of α2δ1 in osteocytes impairs responses to membrane stretch, and global deletion of α2δ1 in mice results in osteopenia and impaired skeletal responses to loading in vivo. Therefore, we hypothesized that the α2δ1 subunit functions as a mechanotransducer, and its deletion in osteocytes would impair skeletal development and load-induced bone formation. Mice (C57BL/6) with LoxP sequences flanking Cacna2d1, the gene encoding α2δ1, were crossed with mice expressing Cre under the control of the Dmp1 promoter (10 kb). Deletion of α2δ1 in osteocytes and late-stage osteoblasts decreased femoral bone quantity (P < .05) by DXA, reduced relative osteoid surface (P < .05), and altered osteoblast and osteocyte regulatory gene expression (P < .01). Cacna2d1f/f, Cre + male mice displayed decreased femoral strength and lower 10-wk cancellous bone in vivo micro-computed tomography measurements at the proximal tibia (P < .01) compared to controls, whereas Cacna2d1f/f, Cre + female mice showed impaired 20-wk cancellous and cortical bone ex vivo micro-computed tomography measurements (P < .05) vs controls. Deletion of α2δ1 in osteocytes and late-stage osteoblasts suppressed load-induced calcium signaling in vivo and decreased anabolic responses to mechanical loading in male mice, demonstrating decreased mechanosensitivity. Collectively, the α2δ1 auxiliary subunit is essential for the regulation of osteoid-formation, femur strength, and load-induced bone formation in male mice.


The ability of bone to sense and respond to forces generated during daily physical activities is essential to skeletal health. Although several bone cell types contribute to the maintenance of bone health, osteocytes are thought to be the primary mechanosensitive cells; however, the mechanisms through which these cells perceive mechanical stimuli remains unclear. Previous work has shown that voltage sensitive calcium channels are necessary for bone to sense mechanical force; yet the means by which those channels translate the physical signal into a biochemical signal is unclear. Data within this manuscript demonstrate that the extracellular α2δ1 subunit of voltage sensitive calcium channels is necessary for load-induced bone formation as well as to enable calcium influx within osteocytes. As this subunit enables physical interactions of the channel pore with the extracellular matrix, our data demonstrate the need for the α2δ1 subunit for mechanically induced bone adaptation, thus serving as a physical conduit through which mechanical signals from the bone matrix are transduced into biochemical signals by enabling calcium influx into osteocytes.


Assuntos
Osteócitos , Osteogênese , Camundongos , Masculino , Feminino , Animais , Osteócitos/metabolismo , Osteogênese/genética , Cálcio/metabolismo , Microtomografia por Raio-X , Camundongos Endogâmicos C57BL , Osteoblastos/metabolismo , Fêmur/diagnóstico por imagem , Fêmur/metabolismo , Canais de Cálcio/genética , Canais de Cálcio/metabolismo
9.
JBMR Plus ; 8(2): ziad008, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38505532

RESUMO

Voltage-sensitive calcium channels (VSCCs) influence bone structure and function, including anabolic responses to mechanical loading. While the pore-forming (α1) subunit of VSCCs allows Ca2+ influx, auxiliary subunits regulate the biophysical properties of the pore. The α2δ1 subunit influences gating kinetics of the α1 pore and enables mechanically induced signaling in osteocytes; however, the skeletal function of α2δ1 in vivo remains unknown. In this work, we examined the skeletal consequences of deleting Cacna2d1, the gene encoding α2δ1. Dual-energy X-ray absorptiometry and microcomputed tomography imaging demonstrated that deletion of α2δ1 diminished bone mineral content and density in both male and female C57BL/6 mice. Structural differences manifested in both trabecular and cortical bone for males, while the absence of α2δ1 affected only cortical bone in female mice. Deletion of α2δ1 impaired skeletal mechanical properties in both sexes, as measured by three-point bending to failure. While no changes in osteoblast number or activity were found for either sex, male mice displayed a significant increase in osteoclast number, accompanied by increased eroded bone surface and upregulation of genes that regulate osteoclast differentiation. Deletion of α2δ1 also rendered the skeleton insensitive to exogenous mechanical loading in males. While previous work demonstrates that VSCCs are essential for anabolic responses to mechanical loading, the mechanism by which these channels sense and respond to force remained unclear. Our data demonstrate that the α2δ1 auxiliary VSCC subunit functions to maintain baseline bone mass and strength through regulation of osteoclast activity and also provides skeletal mechanotransduction in male mice. These data reveal a molecular player in our understanding of the mechanisms by which VSCCs influence skeletal adaptation.

10.
Actual. osteol ; 13(3): 207-213, Sept - DIc. 2017. ilus, graf
Artigo em Inglês | LILACS | ID: biblio-1117111

RESUMO

Osteocytes are the most abundant bone cell and are formed when osteoblasts become embedded in the bone matrix. Through changes in gene expression and paracrine effects, osteocytes regulate the number of osteoblasts, bone forming cells, and osteoclasts, bone resorbing cells, which are needed to maintain bone mass. MLO-Y4 is the better characterized osteocytic cell line; however, lacks expression of sclerostin, the product of the SOST gene, which is fundamental for osteocyte function and blocks bone formation. With the objective to isolate MLO-Y4 clones with different gene expression profiles, we performed cultures at very low density of MLO-Y4 cells stably transfected with nuclear green fluorescent protein (MLOnGFP). Cell morphology was visualized under a fluorescence microscope. Once the cells reached 80% confluency, RNA was extracted and quantitative real time PCR was performed. Clones exhibit different sizes and morphology, with some cells showing a spindle-like shape and others with abundant projections and a star-like shape. Gene expression also differed among clones. However, none of the clones examined expressed SOST. We conclude that the MLO-nGFP clones constitute a useful tool to study osteocyte differentiation and the role of osteocytes in the control of bone formation and resorption in vitro. (AU)


Los osteocitos son las células más abundantes del hueso y se forman cuando los osteoblastos se encuentran rodeados de matriz ósea. A través de cambios en la expresión génica y efectos paracrinos, los osteocitos controlan el número de osteoblastos que forman el hueso, y osteoclastos que resorben el hueso, células necesarias para mantener la masa ósea. Las células MLO-Y4 son la línea celular osteocítica más investigada; sin embargo, no expresan esclerostina, el pro esclerostina, el producto del gen SOST que bloquea la formación ósea y es indispensable para la función de los osteocitos. Con el objetivo de aislar clones de las células MLO-Y4 con diferentes perfiles de expresión génica, realizamos cultivos a muy baja densidad de las células transfectadas en forma estable con proteína verde fluorescente nuclear (MLO-nGFP). La morfología celular fue evaluada utilizando un microscopio de fluorescencia. Una vez que las células alcanzaron el 80% de confluencia, el ARN fue extraído y analizado por PCR cuantitativa en tiempo real. Las células de los diferentes clones tienen diferentes tamaños y morfología, algunas células son fusiformes y otras con proyecciones citoplasmáticas abundantes y en forma de estrella. La expresión de los genes también varió en los distintos clones. Sin embargo, ninguno de ellos expresó SOST. En conclusión, los clones de las células MLO-nGFP constituyen una herramienta útil para estudiar la diferenciación de los osteocitos y el rol de estas células en el control de la formación y resorción ósea in vitro. (AU)


Assuntos
Humanos , Masculino , Feminino , Osteoblastos/citologia , Osteoclastos/citologia , Osteócitos/citologia , Linhagem Celular , Células Clonais/citologia , Osteoblastos/metabolismo , Osteoclastos/metabolismo , Osteócitos/metabolismo , Osteogênese/genética , Reabsorção Óssea/genética , Técnicas In Vitro , RNA/análise , Expressão Gênica , Reação em Cadeia da Polimerase , Colágeno/genética , Fosfatase Alcalina/metabolismo , Fluorescência , Antibacterianos/administração & dosagem
11.
Actual. osteol ; 12(1): 11-20, 2016. ilus
Artigo em Inglês | LILACS, UNISALUD, BINACIS | ID: biblio-1379682

RESUMO

Bisphosphonates (BPs) anti-fracture efficacy may be due in part to inhibition of osteocyte apoptosis. This effect requires opening of connexin (Cx) 43 hemichannels and phosphorylation of the extracellular signal regulated kinases (ERKs). However, unlike ERK activation by other stimuli, the Cx43/ERK pathway activated by BPs does not result in nuclear ERK accumulation. Instead, the anti-apoptotic effect of BPs depends on phosphorylation of cytoplasmic ERK targets and is abolished by forced nuclear retention of ERKs. We now report that ERKs and the scaffolding protein ß-arrestin co-immuno-precipitate with Cx43 in MLO-Y4 osteocytic cells and that the BP alendronate increases this association. Moreover, ERK2 fused to red fluorescent protein (ERK2-RFP) co-localizes with Cx43 fused to green fluorescent protein outside the nucleus in cells untreated or treated with alendronate. Alendronate does not induce ERK nuclear accumulation in cells transfected with wild type ß-arrestin (wtARR) or vector control, whereas it does in cells expressing a dominant negative ß-arrestin mutant (dnARR) consisting of the ß-arrestin-clathrin binding domain that competes with endogenous ß-arrestin for binding to clathrin. Alendronate activates ERKs in dnARRtransfected cells as effectively as in cells transfected with wtARR, demonstrating that dnARR only interferes with subcellular localization but not with activation of ERKs by BPs. Further, whereas alendronate inhibits apoptosis in cells expressing wtARR or vector control, it is ineffective in cells expressing dnARR. Thus, BPs induce the formation of a complex comprising Cx43, ß-arrestin, and clathrin, which directs ERKs outside the nucleus and is indispensable for osteocyte survival induced by BPs. (AU)


La efectividad de los bisfosfonatos (BPs) en la prevención de fracturas puede deberse en parte a la inhibición de la apoptosis de osteocitos. Este efecto depende de la apertura de hemicanales de conexina (Cx) 43 y la fosforilación de quinasas reguladas por señales extracelulares (ERKs). Sin embargo, a diferencia de la activación de ERKs debida a otros estímulos, la vía de señalización Cx43/ERK activada por BPs no conlleva la acumulación de ERKs en el núcleo. El efecto anti-apoptótico de los BPs depende de la fosforilación de blancos citoplasmáticos de ERKs y es inhibido cuando las quinasas son retenidas en el núcleo. En este estudio hemos demostrado que ERKs y la proteína "scaffolding" ß-arrestina co-inmunoprecipitan con Cx43 en células osteocíticas MLO-Y4 y que alendronato aumenta esta asociación. Más aún, ERK2 fusionada a la proteína roja fluorescente (ERK2-RFP) co-localiza con Cx43 fusionada con la proteína verde fluorescente fuera del núcleo en células tratadas con vehículo o alendronato. Alendronato no indujo la acumulación nuclear de ERK en células transfectadas con ß-arrestina nativa (wtARR) o con un vector control, pero si lo hizo en células que expresan una forma dominante negativa de ß-arrestina (dnARR), consistente en el dominio de interacción entre ß-arrestina y clatrina, y que compite con ß-arrestina endógena por la unión a clatrina. Alendronato activa ERKs con la misma eficiencia en células transfectadas con dnARR o wtARR, demostrando que dnARR sólo interfiere con la localización subcelular de ERKs, pero no con su activación inducida por los BPs. Más aún, mientras alendronato inhibe apoptosis en células que expresan wtARR o vector control, es inefectivo en células que expresan dnARR. En conclusión, los BPs inducen la formación de un complejo que incluye Cx43, ß-arrestina y clatrina, el cual retiene ERKs fuera del núcleo y es indispensable para la sobrevida de los osteocitos inducida por estas drogas. (AU)


Assuntos
Osteócitos/citologia , Núcleo Celular/enzimologia , Apoptose/efeitos dos fármacos , Conexina 43/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Difosfonatos/farmacologia , beta-Arrestinas/metabolismo , Osteócitos/efeitos dos fármacos , Osteócitos/metabolismo , Osso e Ossos/citologia , Sobrevivência Celular/efeitos dos fármacos
13.
Actual. osteol ; 6(1): 16-23, ene.-abr. 2010. graf, ilus
Artigo em Espanhol | LILACS | ID: lil-614304

RESUMO

Los bifosfonatos son drogas ampliamente utilizadas para el tratamiento de patologías en las que hay un aumento en la fragilidad ósea. Estos agentes detienen la pérdida de hueso al inhibir la actividad de los osteoclastos, las células que resorben el hueso. Sin embargo, el modesto efecto de los bifosfonatos en el aumento en la masa ósea no explica completamente la disminución en la incidencia de fracturas observada en individuos tratados con estos agentes. Basados en la falta de correlación entre el aumento de la densidad mineral y la disminución en la incidencia de fracturas, hemos explorado la posibilidad de que parte del efecto beneficioso de los bifosfonatos se debe a la inhibición de la apoptosis de los osteocitos. Los osteocitos, osteoblastos diferenciados que se rodean de matriz ósea, constituyen la mayoría de las células que forman el hueso, y, a través de sus prolongaciones, forman una red que recorre el hueso. Debido a su posición en el hueso, los osteocitos constituyen las células ideales para percibir cambios mecánicos u hormonales e iniciar señales que llevan a la reparación del tejido, previniendo el deterioro del hueso y la posibilidad de fracturas. Los osteocitos se comunican entre sí y con las células en la superficie del hueso a través de canales de conexinas (Cx), especialmente Cx43. Nuestro grupo ha demostrado que los bifosfonatos, aún los que carecen de actividad anti-catabólica, previenen la apoptosis de osteocitos in vitro e in vivo. La protección de la viabilidad celular requiere la apertura de hemicanales de Cx43, pero es independiente de la activación de las uniones gap. La apertura de los hemicanales es seguida por la activación de la quinasas Src y ERKs.


Assuntos
Humanos , Apoptose , Densidade Óssea , Difosfonatos/farmacologia , Difosfonatos/uso terapêutico , Osteócitos , Osteogênese Imperfeita/tratamento farmacológico , Reabsorção Óssea/tratamento farmacológico , Tratamento Farmacológico
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