RESUMO
The periodontal ligament (PDL) is one of the connective tissues located between the tooth and bone. It is characterized by rapid turnover. Periodontal ligament fibroblasts (PDLFs) play major roles in the rapid turnover of the PDL. Microarray analysis of human PDLFs (HPDLFs) and human dermal fibroblasts (HDFs) demonstrated markedly high expression of chemokine (CXC motif) ligand 12 (CXCL12) in the HPDLFs. CXCL12 plays an important role in the migration of mesenchymal stem cells (MSCs). The function of CXCL12 in the periodontal ligament was investigated in HPDLFs. Expression of CXCL12 in HPDLFs and HDFs was examined by RT-PCR, qRT-PCR and ELISA. Chemotactic ability of CXCL12 was evaluated in both PDLFs and HDFs by migration assay of MSCs. CXCL12 was also immunohistochemically examined in the PDL in vivo. Expression of CXCL12 in the HPDLFs was much higher than that in HDFs in vitro. Migration assay demonstrated that the number of migrated MSCs by HPDLFs was significantly higher than that by HDFs. In addition, the migrated MSCs also expressed CXCL12 and several genes that are familiar to fibroblasts. CXCL12 was immunohistochemically localized in the fibroblasts in the PDL of rat molars. The results suggest that PDLFs synthesize and secrete CXCL12 protein and that CXCL12 induces migration of MSCs in the PDL in order to maintain rapid turnover of the PDL.
Assuntos
Movimento Celular/fisiologia , Quimiocina CXCL12/metabolismo , Fibroblastos/metabolismo , Ligamento Periodontal/citologia , Adolescente , Adulto , Células Cultivadas , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imuno-Histoquímica , Masculino , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Adulto JovemRESUMO
Among the various kinds of fibroblasts existing in the human body, the periodontal ligament (PDL) fibroblasts have been suggested as multipotent cells. Periodontal ligament fibroblasts are characterized by rapid turnover, a high remodeling capacity and remarkable capacity for renewal and repair. They also differentiate into osteoblasts and cementoblasts. We established iPS cells from human PDL fibroblasts by introducing the ES cell markers Oct3/4, Sox2, Nanog, Klf4 and Lin28 by retrovirus transduction, even without the oncogene c-Myc. The iPS cells established in this study expressed the ES cell markers and formed teratomas in SCID mice. The c-Myc expression level in the PDL fibroblasts was higher than that in the iPS cells by quantitative RT-PCR. Therefore, we have concluded that PDL fibroblasts could be an optimal cell source for iPS cells.
Assuntos
Fibroblastos/citologia , Células-Tronco Pluripotentes Induzidas/citologia , Ligamento Periodontal/metabolismo , Adolescente , Animais , Diferenciação Celular , Células Cultivadas , Fibroblastos/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Fator 4 Semelhante a Kruppel , Masculino , Camundongos , Camundongos SCIDRESUMO
Heat shock proteins (HSPs) are molecular chaperones that maintain intracellular protein homeostasis and ensure survival of cells. Continuous orthodontic force on the tooth is considered to be a type of physical stress loaded to the periodontal ligament (PDL). However, little is known about the role of HSPs during tooth movement. This study was performed to examine the expression of HSPs in the PDL during tooth movement using laser microdissection, microarray analysis, real-time RT-PCR and immunohistochemistry. Gene expression of HSPA1A in the pressure zone of the PDL was higher during 6 h of tooth movement than in the control group. Expression of HSPA1A decreased with time. HSPA1A was also detected in the pressure zone of the PDL at the protein level 24 h after the initial tissue change. These results strongly suggest that expression of HSPA1A in the PDL during early stages of tooth movement is a critical factor for tissue reaction.
