Efeitos da ativação do PPAR gama no reparo ósseo e na ósseointegração de implantes dentários
Carregando...
Data
2020-10-26
Autores
Junger, Bruna [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Os receptores ativados por proliferadores de peroxissoma de isoforma gama (PPAR-gama) são fatores de transcrição que se encontram no entrelaçamento de várias vias metabólicas e determinam a gênese da obesidade e doenças associadas. Estudos recentes têm relatado o potencial dos medicamentos agonistas PPARs, usados no tratamento de doenças cardiovasculares e diabetes tipo 2, de afetar a função das células ósseas e o risco de fratura. O objetivo deste estudo foi avaliar os efeitos da ativação do PPAR-gama no processo de reparo ósseo e osseointegração de implantes dentários. Foram utilizados 42 ratos Wistar alimentados com ração sólida padrão para roedores e água “ad Libitum”. A administração do agonista PPAR-gama(durante 4 semanas) foi realizada incorporada à dieta perfazendo dois grupos experimentais: Grupo Controle (SC) e Grupo PPAR-gama (SC-gama). Os animais, em seguida, foram submetidos a procedimento cirúrgico para instalação de implantes dentários e confecção de defeitos ósseos nas tíbias direita e esquerda, respectivamente. Após períodos de 7, 15 e 45 dias os animais foram eutanasiados e as tíbias removidas seguiram para processamento e posterior análise histológica descritiva e histomorfometria. Em relação aos defeitos, no aspecto histológico descritivo, em todos os períodos analisados, há atraso no reparo ósseo do grupo SC-gama em relação ao SC. A histomorfometria apresenta diferença comparando os grupos teste e controle nos parâmetros ossoneoformado (ON) em 7 dias (P=0,0374) e 15 dias (P=0,0134) e osso maduro (OM) em 15 dias (P=0,0009). Em 45 dias, os valores tanto de OM quanto de ON não apresentam significância. Já as tíbias onde o implante foi instalado, nas áreas de roscas os dois grupos apresentam-se muito semelhantes tanto aos eventos celulares quanto à maturação óssea exceto no período de 15 dias onde o grupo teste apresentou atraso no reparo peri-implantar. Conclui-se que, em relação ao reparo ósseo o processo de diferenciação e remodelação é lento no grupo tratado; e em relação ao reparo peri-implantar o comportamento biológico demonstra atraso do grupo tratado apenas no período intermediário.
The peroxisome proliferator-activated receptor-gamma isoform (PPAR–gamma) are transcription factors found in the interlacing of several metabolic pathways that determine the genesis of obesity and associated diseases. Recent studies have reported the potential of PPAR agonist drugs, used to treat cardiovascular disease and type 2 diabetes, to affect bone cell function and fracture risk. This study aimed to evaluate the effects of PPAR-gamma activation on the process of bone repair and osseointegration of dental implants. Thirty-six Wistar rats received standard rodent solid chow and "ad Libitum" water. The administration of the PPAR-gamma agonist (during four weeks) was performed incorporated into the diet, making two experimental groups: Control Group (SC) and PPAR gamma Group (SC-gama). The animals were then submitted to a surgical procedure to install dental implants and make bone defects in the right and left tibias, respectively. After periods of 7, 15, and 45 days the animals were euthanized, the tibiae were removed for histological protocols and subsequent descriptive histological analysis and histomorphometry. Concerning the defects, the descriptive histological aspect revealed a slight delay in bone repair in the SC-gamma group in comparison with the SC for all parameters. Conversely, the histomorphometry showed difference between the groups regarding neoformed bone (NB) in 7 days (P = 0.0374) and 15 days (P = 0.0134) and mature bone (MB) in 15 days (P = 0.0009). At 45 days, there were no differences between the groups regarding MB and NB. As for tibiae, where the implant was placed, the two groups were similar to both cellular events and bone maturation in the areas of threads, except at 15 days where the test group showed delay in peri-implant repair. In conclusion, regarding the bone defect, the process of differentiation and remodeling is slow in the treated group. Regarding the implant, a descriptive histological analysis showed biological behavior delay in the treated group only in the intermediate period.
The peroxisome proliferator-activated receptor-gamma isoform (PPAR–gamma) are transcription factors found in the interlacing of several metabolic pathways that determine the genesis of obesity and associated diseases. Recent studies have reported the potential of PPAR agonist drugs, used to treat cardiovascular disease and type 2 diabetes, to affect bone cell function and fracture risk. This study aimed to evaluate the effects of PPAR-gamma activation on the process of bone repair and osseointegration of dental implants. Thirty-six Wistar rats received standard rodent solid chow and "ad Libitum" water. The administration of the PPAR-gamma agonist (during four weeks) was performed incorporated into the diet, making two experimental groups: Control Group (SC) and PPAR gamma Group (SC-gama). The animals were then submitted to a surgical procedure to install dental implants and make bone defects in the right and left tibias, respectively. After periods of 7, 15, and 45 days the animals were euthanized, the tibiae were removed for histological protocols and subsequent descriptive histological analysis and histomorphometry. Concerning the defects, the descriptive histological aspect revealed a slight delay in bone repair in the SC-gamma group in comparison with the SC for all parameters. Conversely, the histomorphometry showed difference between the groups regarding neoformed bone (NB) in 7 days (P = 0.0374) and 15 days (P = 0.0134) and mature bone (MB) in 15 days (P = 0.0009). At 45 days, there were no differences between the groups regarding MB and NB. As for tibiae, where the implant was placed, the two groups were similar to both cellular events and bone maturation in the areas of threads, except at 15 days where the test group showed delay in peri-implant repair. In conclusion, regarding the bone defect, the process of differentiation and remodeling is slow in the treated group. Regarding the implant, a descriptive histological analysis showed biological behavior delay in the treated group only in the intermediate period.
Descrição
Palavras-chave
Osso e ossos, Metabolismo, PPAR gama, Implantes dentários, Dental implants