Associação entre obesidade e adipocinas na saliva e fluido gengival crevicular: uma revisão sistemática e meta-análise / Association between obesity and adipokines´ levels in saliva and gingival crevicular fluid: a systematic review

A obesidade vem aumentando sua prevalência na população mundial e brasileira nos últimos anos, atingindo todas as faixas etárias. As adipocinas são um grupo de citocinas inflamatórias produzidas ou expressas no tecido adiposo, que desempenham diversas funções no organismo. Classicamente essas moléculas são avaliadas no soro ou tecido adiposo. Estudos recentes, entretanto, têm avaliado a presença destas moléculas na saliva e no fluido gengival crevicular (FGC) e sua associação com a obesidade. Dessa forma, o objetivo desse trabalho foi avaliar a associação entre obesidade e a concentração de adipocinas na saliva e FGC. A busca eletrônica foi realizada em quatro bases de dados. Buscas manuais e no Google Acadêmico também foram realizadas. Dois autores calibrados (Kappa=0.82) realizaram a seleção dos artigos, a extração de dados e avaliaram o risco de viés por meio da análise de qualidade metodológica dos artigos incluídos. Trinta e quatro artigos foram incluídos. As meta-análises demonstraram que a concentração aumentada de TNF-α na saliva de indivíduos com obesidade quando comparado aos não obesos. Em contrapartida, concentrações de resistina, adiponectina, leptina, grelina e IL-6 na saliva e de resistina, adiponectina, leptina, IL-6, IL-8, TNF-α e PAI-1 no FGC foram estatisticamente similares em indivíduos com e sem obesidade. Em geral, a evidência científica a respeito de níveis alterados de adipocinas específicas na saliva e/ou no FGC em quadros de obesidade é fraca, exceto para o TNF-α na saliva. A disponibilidade limitada e a heterogeneidade dos dados não permitem afirmar se as alterações nos níveis de adipocinas na saliva e no FGC estão associadas à obesidade ou a outras causas.(AU)

Association between obesity and adipokines´ levels in saliva and gingival crevicular fluid: a systematic review. Obesity is an increasing disease characterized by accumulation of fat in different organs and tissues. Currently, adipose tissue has been described as an endocrine organ, once it secrets a lot of metabolic active molecules, inflammatory cytokines and adipokines. Several molecules are classified as adipokines and they are classically evaluated in blood or adipose tissue. Recent studies have been evaluating adipokines in gingival crevicular fluid (GCF) and saliva and its relation to obesity. The objective of this systematic review was to evaluate the association between obesity and the concentration of adipokines in gingival crevicular fluid (GCF) and saliva. The search was conducted in four databases. Manual and Google Scholar searches were also conducted. Two calibrated authors performed study selection, data extraction and quality assessment of included articles. Thirty four articles were included. Metaanalysis demonstrated that TNF-α concentration in saliva was statistically increased in individuals with obesity compared with individuals without obesity. In contrast, concentrations of resistin, adiponectin, leptin, ghrelin and IL-6 in saliva and of resistin, adiponectin, leptin, IL-6, IL-8, TNF-α, IL-8 and PAI-1 in GCF, were statistically similar in individuals with and without obesity. Overall, the scientific evidence regarding altered levels of specific adipokines in saliva and or GCF among persons with obesity is weak, except for salivary TNF-α. The limited availability and heterogeneity of data do not allow us to state whether changes of adipokines in GCF and saliva are associated with obesity or otherwise.(AU)

Contribution of atypical chemokine receptor 2/ackr2 in bone remodeling.

INTRODUCTION: Bone remodeling is a tightly regulated process influenced by chemokines. ACKR2 is a decoy receptor for CC chemokines functioning as regulator of inflammatory response. In this study we investigated whether the absence of ACKR2 would affect bone phenotype and remodeling induced by mechanical loading. METHODS: An orthodontic appliance was placed between incisors and first molar of ACKR2 deficient (ACKR2-/-) and C57BL6/J (wild-type/WT) mice. Microtomography, histology and qPCR were performed to evaluate bone parameters, orthodontic tooth movement (OTM), bone cells counts and the expression of ACKR2, bone remodeling markers, CC chemokines and chemokines receptors. Bone marrow cells (BMC) from WT and ACKR2-/- mice were differentiated in osteoclasts and osteoblasts for analysis of activity and expression of specific markers. RESULTS: Mechanical stimulus induced ACKR2 production in periodontium. The expression of ACKR2 in vitro was mostly detected in mature osteoclasts and early-differentiated osteoblasts. Although ACKR2-/- mice exhibited regular phenotype in maxillary bone, the amount of OTM, osteoclasts counts and the expression of pro-resorptive markers were increased in this group. In contrast, the number of osteoblasts and related markers were decreased. OTM resulted in augmented expression of CC chemokines and receptors CCR5 and CCR1 in periodontium, which was higher in ACKR2-/- than WT mice. In vitro experiments demonstrated an augmented formation of osteoclasts and diminished differentiation of osteoblasts in ACKR2-/- mice. CONCLUSIONS: These data suggests that ACKR2 functions as a regulator of mechanically-induced bone remodeling by affecting the differentiation and activity of bone cells and the availability of CC chemokines at periodontal microenvironment. Therapeutic strategies based on increase of ACKR2 might be useful to hinder bone loss in inflammatory conditions.