Biologia Molecular

Cytokine 42 (2008) 330–335

Contents lists available at ScienceDirect

Cytokine
journal homepage: www.elsevier.com/locate/issn/10434666

Differential expression of osteoblast and osteoclast chemmoatractants in
compression and tension sides during orthodontic movement
Thiago Pompermaier Garlet a, Ulisses Coelho b, Carlos Eduardo Repeke c, João Santana Silva d,
Fernando de Queiroz Cunhaa, Gustavo Pompermaier Garlet c,*
a

Department of Pharmacology, School of Medicine of Ribeirão Preto, São Paulo University—FMRP/USP, Brazil
Department of Dentistry, Ponta Grossa State University, UEPG, Brazil
c
Department of Biological Sciences, Bauru School of Dentistry, São Paulo University—FOB/USP, Al. Octávio Pinheiro Brisola, 9-75, CEP 17012-901 Bauru, SP, Brazil
d
Department ofBiochemistry and Immunology, School of Medicine of Ribeirão Preto, São Paulo University—FMRP/USP, Brazil
b

article

info

Article history:
Received 3 December 2007
Received in revised form 31 January 2008
Accepted 5 March 2008

Keywords:
Chemokines
Orthodontic tooth movement
Bone resorption
Bone formation

abstract
Orthodontic tooth movement is achieved by the remodeling of alveolarbone in response to mechanical
loading, and is supposed to be mediated by several host mediators, such as chemokines. In this study
we investigated the pattern of mRNAs expression encoding for osteoblast and osteoclast related chemokines, and further correlated them with the profile of bone remodeling markers in palatal and buccal
sides of tooth under orthodontic force, where tensile (T) andcompressive (C) forces, respectively, predominate. Real-time PCR was performed with periodontal ligament mRNA from samples of T and C
sides of human teeth submitted to rapid maxillary expansion, while periodontal ligament of normal
teeth were used as controls. Results showed that both T and C sides exhibited significant higher expression of all targets when compared to controls. Comparing C and Tsides, C side exhibited higher expression of MCP-1/CCL2, MIP-1a/CCL3 and RANKL, while T side presented higher expression of OCN. The
expression of RANTES/CCL5 and SDF-1/CXCL12 was similar in C and T sides. Our data demonstrate a
differential expression of chemokines in compressed and stretched PDL during orthodontic tooth movement, suggesting that chemokines pattern may contribute to thedifferential bone remodeling in
response to orthodontic force through the establishment of distinct microenvironments in compression
and tension sides.
Ó 2008 Elsevier Ltd. All rights reserved.

1. Introduction
Orthodontic tooth movement is achieved by the remodeling of
periodontal ligament (PDL) and alveolar bone in response to
mechanical loading [1–3]. The mechanical loading patterns are
quitecomplex due to the intricate anatomy and tissue structure,
as shown by Finite Element analysis [4]. However, Finite Element
studies are only able to determine pure mechanical force, but are
not capable of predicting the biological tissue response, impairing
the exact identification of the PDL areas submitted to tensile or
stretching forces throughout the tooth displacement process
in vivo.However, although being a simplification, based on the predominant forces and in the overall tissue response two opposing
distinct sides can be named tension (where the displacement of
the dental root creates a strain force in the PDL fibers) and compression (where a compression force is created by the root against
* Corresponding author. Fax: +55 14 3235 8274.
E-mail address: garletgp@usp.br(G.P. Garlet).
1043-4666/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved.
doi:10.1016/j.cyto.2008.03.003

the bone, and the fibers are unloaded) sides [1,2,4]. Albeit simplified, the assumption that the transduction of tensile and compressive forces triggers different patterns of tissue remodeling
(characterized by selective bone resorption and deposition in compression and tension...