Microarray Analysis of Differential Gene Expression Between Traumatic Temporomandibular Joint Fibrous and Bony Ankylosis in a Sheep Model

Abstract

Background The type of traumatic temporomandibular joint (TMJ) ankylosis depends on the degree of severity of TMJ trauma. Here, we performed comprehensive differential molecular profiling between TMJ fibrous and bony ankylosis. Material/Methods Six sheep were used and a bilateral different degree of TMJ trauma was performed to induce fibrous ankylosis in one side and bony ankylosis in the other side. The ankylosed calluses were harvested at days 14 and 28 postoperatively and analyzed by Affymetrix OviGene-1_0-ST microarrays. DAVID was used to perform the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis for the different expression genes (DEGs). The DEGs were also typed into protein–protein interaction (PPI) networks to get the interaction data. Ten DEGs, including 7 hub genes from PPI analysis, were confirmed by real-time PCR. Results We found 90 and 323 DEGs at least 2-fold at days 14 and 28, respectively. At day 14, bony ankylosis showed upregulated DEGs, such as TLR8, SYK, NFKBIA, PTPRC, CD86, ITGAM, and ITGAL, indicating a stronger immune and inflammatory response and cell adhesion, while genes associated with anti-adhesion (PRG4) and inhibition of osteoblast differentiation (SFRP1) had higher expression in fibrous ankylosis. At day 28, bony ankylosis showed increased biological process related to new bone formation, while fibrous ankylosis was characterized by a prolonged immune and inflammatory reaction. Conclusions This study provides a differential gene expression profile between TMJ fibrous and bony ankylosis. Further study of these key genes may provide new ideas for future treatment of TMJ bony ankylosis.

Absorbance or organization into ankylosis: a microarray analysis of haemarthrosis in a sheep model of temporomandibular joint trauma

“…The animal model was established according to the protocol outlined in our previous publication [ 7 ]. The method of anesthesia, analgesia and euthanasia used for sheep was the same as described previously [ 12 ]. All animals received bilateral TMJ surgery.…”

“…Therefore the experimental haemarthrosis with or without removal of articular fibrous layers is an established and suitable model for gene expression profiling studies regarding the onset of TMJ ankylosis. Our group has previously used a condylar fracture model to analyze the differential gene expression profiles between traumatic TMJ fibrous and bony ankylosis [ 12 ]. Recently, Zhang et al [ 13 ] also explored the role of lateral pterygoid muscle in the traumatic TMJ ankylosis by gene chip.…”

Temporal gene expression profiling during early-stage traumatic temporomandibular joint bony ankylosis in a sheep model

“…1 ). The animals were euthanized in the same manner as in our previous study [ 6 ], that is, euthanized with a lethal dose of pentobarbital sodium (120 mg/kg) through the external jugular vein, and animal death was confirmed by observing respiratory and heartbeat arrest and loss of pupillary light and nerve reflexes. The haematoma or newly generated ankylosed callus in the joint spaces was harvested as described in a previous study [ 17 ].…”

“…The RNA preparation and microarray assay were performed by the CNKINGBIO Corporation (Beijing, China), as described in previous studies [ 6 , 17 ]: TRIzol reagent (Invitrogen Life Technologies, Carlsbad, USA) was used to extract total RNA, and a RNEasy small kit (Qiagen, Valencia, USA) was used to purify the extracted total RNA. Gene expression was analysed using the Affymetrix Ovine Gene 1.0 ST Array (Affymetrix, Santa Clara, CA, United States), which comprised over 22,047 known transcripts and expressed sequence tags.…”

“…The development of traumatic TMJ ankylosis is essentially a variation of bone healing, especially similar to delayed bone healing or hypertrophic nonunion [ 5 ]. The course from TMJ trauma to ankylosed joint is a highly sophisticated regenerative process, in which the early-stage inflammatory response and cell adhesion [ 6 ], the committed differentiation of mesenchymal stem cells [ 7 ], the changed mechanical stress [ 1 , 8 ], the complex biological pathways and signaling molecules [ 1 , 8 – 10 ], and the presumed genetic predisposition [ 1 ] could interact with each other.…”