Effects of ionizing radiation on bone neoformation: histometric study in Wistar rats tibiae

Lucatto, Susette Cavicchioli; Guilherme, Arnaldo; Dib, Luciano Lauria; Segreto, Helena Regina Cômodo; Alves, Maria Tereza de Seixas; Gumieiro, Emne Hammoud; Jahn, Ricardo Schmitutz; Leite, Ronaldo Antonio

doi:10.1590/s0102-86502011000600012

Cited by 9 publications

(3 citation statements)

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“…In the present study, histomorphometric analyses showed lower bone matrix levels in C30 compared with IR30. Some studies have reported that irradiation changed the bone turnover, significantly reduced vessel diameter [18] and could decrease remodeling process, which showed more bone matrix formation [24]. Thus, the higher matrix values shown in IR30 probably reflected changes and delay in the bone remodeling process.…”

Section: Discussionmentioning

confidence: 99%

Ionizing radiation and bone quality: time-dependent effects

et al. 2019

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BackgroundThe aim of this study was to evaluate the ionizing radiation (IR) effects on rat bone 30 and 60 days after irradiation.MethodsWistar rats were submitted to IR (30 Gy) on the left leg and were euthanized after 30 and 60 days. The legs were divided into four groups according to the treatment and euthanization time: C30 and C60 (right leg–without IR), IR30 and IR60 (left leg-with IR).ResultsCT analysis showed more radiodensity in C60 compared with other groups, and IR60 showed more radiodensity than IR30. In histomorphometric analysis, C30 showed lower bone matrix values compared with IR30 and C60. Lacunarity analyses showed more homogeneous bone channel distribution in C30 than IR30. ATR-FTIR showed decrease in ratio of mature and immature crosslinks in IR30 compared with C30. Crystallinity Index was decrease in IR60 compared with C60. The Amide III + Collagen/HA ratio was increased in C60 compared with C30; however this ratio decreased in IR60 compared with IR30. Biomechanical analysis showed lower values in IR groups in both time.ConclusionsIR damaged bone quality and decreased stiffness. Moreover, the results suggested that the deleterious effects of IR increased in the late time points.

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Section: Discussionmentioning

confidence: 99%

Ionizing radiation and bone quality: time-dependent effects

et al. 2019

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“…As demonstrated for high doses in rodent models, damage to bone-forming cells, vasculature, or an impaired hormone balance can be responsible for the loss of bone mass. This is caused by inflammation, a restricted nutrient supply and a reduced bone neoformation ( 14 , 18 ). For lower doses, no such harmful effects have been anticipated ( 19 ).…”

Section: Introductionmentioning

confidence: 99%

Modulation of Differentiation and Bone Resorbing Activity of Human (Pre-) Osteoclasts After X-Ray Exposure

et al. 2022

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Low-dose radiotherapy (LD-RT) is a local treatment option for patients with chronic degenerative and inflammatory diseases, in particular musculoskeletal diseases. Despite reported analgesic and anti-inflammatory effects, cellular and molecular mechanisms related to osteoimmunological effects are still elusive. Here we test the hypothesis that X-irradiation inhibits the differentiation of precursor osteoclasts into mature osteoclasts (mOC) and their bone resorbing activity. Circulating monocytes from healthy donors were isolated and irradiated after attachment with single or fractionated X-ray doses, comparable to an LD-RT treatment scheme. Then monocytes underwent ex vivo differentiation into OC during cultivation up to 21 days, under conditions mimicking the physiological microenvironment of OC on bone. After irradiation, apoptotic frequencies were low, but the total number of OC precursors and mOC decreased up to the end of the cultivation period. On top, we observed an impairment of terminal differentiation, i.e. a smaller fraction of mOC, reduced resorbing activity on bone, and release of collagen fragments. We further analyzed the effect of X-irradiation on multinucleation, resulting from the fusion of precursor OC, which occurs late during OC differentiation. At 21 days after exposure, the observation of smaller cellular areas and a reduced number of nuclei per mOC suggest an impaired fusion of OC precursors to form mOC. Before, at 14 days, the nuclear translocation of Nuclear Factor Of Activated T Cells 1 (NFATc1), a master regulator of osteoclast differentiation and fusion, was decreased. In first results, obtained in the frame of a longitudinal LD-RT study, we previously reported a pain-relieving effect in patients. However, in a subgroup of patients suffering from Calcaneodynia or Achillodynia, we did not observe a consistent decrease of established blood markers for resorption and formation of bone, or modified T cell subtypes involved in regulating these processes. To assess the relevance of changes in bone metabolism for other diseases treated with LD-RT will be subject of further studies. Taken together, we observed that in vitro X-irradiation of monocytes results in an inhibition of the differentiation into bone-resorbing OC and a concomitant reduction of resorbing activity. The detected reduced NFATc1 signaling could be one underlying mechanism.

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“…A radiação ionizante utilizada em diagnósticos e tratamentos é um dos elementos que influenciam no processo de reparo ósseo . As alterações a nível celular e vascular provocadas por altas doses de radiação no tecido ósseo resultam na neoformação de um tecido desorganizado e rico em tecido fibrótico (Barth et al, 2011;Lucatto et al, 2011;Bartlow et al, 2018). Após a exposição à radiação ionizante, ocorrem alterações vasculares que se iniciam com o aumento da permeabilidade das células endoteliais, resultando em disfunção endotelial (Baselet et al, 2018).…”

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Efeitos da radiação ionizante no osso imaturo: influência na rede de osteócitos, padrão de colágeno e microarquitetura

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Aos meus pais, irmãos, sobrinhas, "A família é a demonstração perfeita do amor incondicional."Esteja eu onde estiver, meu coração estará sempre com vocês.Obrigado pelo amor e apoio inesgotáveis. Ao meu companheiro Luciano,"O maior amor está no companheirismo, no confiante e recíproco afeto, na conversa, no carinho constante."Agradeço a benção de poder compartilhar a vida com você. Obrigado pelo pelas palavras doces de incentivo, por todo carinho e atenção com que me acolhe.À minha orientadora Priscilla Barbosa Ferreira Soares, "O êxito da vida não se mede pelo caminho que você conquistou, mas sim pelas dificuldades que superou pelo caminho."Obrigado pelo apoio, ensinamentos e pela confiança depositados em mim. Obrigado pelo carinho com que me recebeu, pela amizade e oportunidade.Você sempre será um exemplo para mim.À minha amiga-irmã Luciana Guarda Marques, "A amizade promove a paz nos corações e fortalece os laços que a distância separa".Obrigado pelo seu carinho e de sua família, me acolhendo sempre com amor. VIII AGRADECIMENTOSAos professores da banca de qualificação, Prof a . Dr a . Camilla

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Effects of ionizing radiation on bone neoformation: histometric study in Wistar rats tibiae

Cited by 9 publications

References 14 publications

Ionizing radiation and bone quality: time-dependent effects

Ionizing radiation and bone quality: time-dependent effects

Modulation of Differentiation and Bone Resorbing Activity of Human (Pre-) Osteoclasts After X-Ray Exposure

Efeitos da radiação ionizante no osso imaturo: influência na rede de osteócitos, padrão de colágeno e microarquitetura

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