ABSTRACT: We used microarrays to detect the differences in gene-expression of the periontal ligament between patients with healthy periodontal ligament and patients with periodontitis RNA was extracted directly from the middle third of the human periodontal ligament
Project description:Periodontitis can impair the osteogenic differentiation of human periodontal mesenchymal stem cells, but the underlying molecular mechanisms are still poorly understood. Long noncoding RNAs (lncRNAs) have been demonstrated to play significant roles under both physiologic and pathological conditions. We performed comprehensive lncRNAs profiling by lncRNA microarray to identify differentially expressed long noncoding RNA expression between Periodontal ligament stem cells from healthy Periodontal tissue and periodontal ligament stem cells from inflammatory periodontal tissue. Our analysis identified 233 lncRNAs and 423 mRNAs that were differently expressed (fold change >2.0, p-value < 0.05) between the two groups of cells. The GO analysis revealed that the significantly down-regulated biological processes included multicellular organismal process, developmental process and multicellular organismal development and the significantly up-regulated biological processes included cellular process, biological regulation and response to stimulus in periodontal ligament stem cells from inflammatory periodontal tissue. The Pathway analysis revealed that the differentially expressed mRNAs may involved in Focal adhesion, ECM-receptor interaction, Bacterial invasion of epithelial cells, Long-term depression, Circadian entrainment and HIF-1 signaling pathway. Two-condition experiment, periodontal ligament stem cells from healthy periodontal tissue (hPDLSCs) vs. periodontal ligament stem cells from inflammatory periodontal tissue (pPDLSCs), Biological replicates: 3 control replicates (hPDLSCs), 3 testing replicates (pPDLSCs).
Project description:The periodontium are the tissues supporting and investing the tooth and consists of the periodontal ligament, the gingiva, the root cementum, and the alveolar bone. The functions of the cell populations in health and disease regarding the host-mediated tissue destruction are not well understood. To get a first idea, of which genes might play a distinct role in chronic periodontal disease in vivo, we compared the genom-wide gene expressions of chronic inflamed and healthy periodontal ligament cells by microarray analysis and validated the data by real-time RT-PCR. The expression rates of 14.239 genes were investigated and 3.018 of them were found differentially expressed by at least two-fold, the expression rates of 1.451 genes were significantly up-regulated and the expression rates of 1.567 genes were significantly down-regulated in inflamed PDL cells. We focused on mainly structural components, for example, laminins and integrins, as well as degrading enzymes, for example, MMPs and cathepsins. The molecular composition of the laminin network varies in chronic inflamed compared to healthy PDL cells in vivo. Furthermore, integrin alpha6beta4, together with laminin-332, might be involved in chronic periodontal inflammation. Findings that diverse keratins were upregulated in chronic disease indicate that the epithelial cell rests of Malassez might also be involved in chronic periodontal inflammation. Also cathepsin B and cathepsin C might participate in the connective tissue destruction. The microarray analysis has identified a profile of genes potentially involved in chronic periodontal inflammation in vivo. Further studies are needed to entirely understand cellular activities during chronic periodontal inflammation in vivo. Experiment Overall Design: Periodontal tissue was collected from 32 patients at the Dental Medical School of the University of Goettingen (12 men, 20 women, aged between 18 and 72 years) from March 2005 to Dezember 2005. The tissue probes were taken from teeth, either extracted for orthodontic reasons (healthy periodontium) or because of chronic periodontal lesions. The differentiation between both collectives was performed using clinical and radiological parameters (clinical attachment loss, increase in probing depth, and radiographic bone loss). A detailed anamnesis of each patient was explored. All patients were without a medical history and were not on medication. In addition, the tissue samples used in our study were only taken from non-smokers. The extracted teeth were immediately frozen and stored at -80°C. All patients who participated in the study were informed about the nature and aim of this project and gave their written informed consent. The study was approved according to the regulations of the Ethics Committee of the Medical Faculty of the University of Goettingen.
Project description:This study investigated which genes regarding root resorption are upregulated by cryopreservation and whether cryopreservation affects the expression of Macrophage –colony stimulating factor. We manufactured the customized template which was made of genes selected regarding root resorption including osteoprotegerin (OPG), receptor activator of nuclear factor-kappa B ligand (RANKL), RANKL’s cognate receptor (RANK), macrophage colony-stimulating factor (M-CSF), interleukin-1β (IL-1β), and tumor necrosis factor-alpha (TNF-α), and bone morphogenetic proteins (BMP) and analyzed gene expression. cultured human periodontal ligament cells (control) VS cryopreserved and cultured periodontal ligament cells(cryopreserved group): 3 control replicates, 3 cryopreserved replicates
Project description:Human periodontal ligament (HPDL) is continuously exposed to mechanical stress in vivo. In this study, in utilizing DNA chips, we analyzed the influences of mechanical stress on the gene expression profile of HPDL cells in vitro. HPDL cells were obtained from extracted first premolars of individuals undergoing tooth extraction for orthodontic treatment. Then, HPDL cells were applied to a stretch apparatus. They were constantly stretched and relaxed at 0.5 Hz for 48hr with 110ï¼ force elongation. After the application of the cyclic tension force, total RNA was extracted. Then, in utilizing the DNA chips (Human Oligo 30K DNA Chip containing almost all human genes in the genome). We analyzed the differences of gene expression between the stretched and the non-stretched control HPDL cells The DNA chip analysis identified 17 up-regulated genes that showed at least 2-fold difference in their relative intensities between the stretched and the control. This result included the genes for the glutamate receptor binding protein: HOMER1, for the growth factor receptor: CNTFR, for the ECM remodeling protein: MMP15, for the protein interacting with calcineurin A: DSCR1, for the cytoskeletal protein: LRRFIP1, for the glutamate receptor: GRIN3A and some novel genes. On the basis of these data, we suggest that mechanical stress, in other words in vivo occlusal force, may affect the functions of HPDL cells Gene expression profiles were constructed using Human Oligo DNA Chip 30K (Hitachi software engineering) in human periodontal ligament cells (The 48-h stretched and the 48-h non-stretched, control).
Project description:This study aimed to investigate the microRNA expression profile of mechnically strained human periodontal ligament-derived stem cells, and SurePrint G3 Human v16 miRNA Array (Agilent) was employed as a screening platform. We discovered 39 differentially expressed microRNAs between the stretched and the static control group. Human periodontal ligament-derived stem cells were cultured on elastic silicone membranes and either subjected to a dynamic mechanical strain protocol (2hr, 5% elongation, 0.5Hz) or left undisturbed. Total RNA was collected and extracted by TRIzol. RNA samples with 28S/18S ratios in the range of 1.4 to 1.8 were used for microRNA microarray analysis using the Agilent SurePrint G3 Human v16 miRNA Array Kit. The samples in each group were triplicated.
Project description:Previous research has reported that FDC-SP had similar molecular properties to statherin, a protein exists in saliva which plays important roles in preventing Ca precipitation. Further biomolecular study has suggested that the expression of FDC-SP may be associated with periodontal ligament (PDL) phenotype expression. Therefore, we hypothesized that FDC-SP may play specific roles in the inhibition of calcium precipitation during periodontal regeneration, as well as affect phenotype expression of periodontal ligament cells (PDLCs) during the differentiation process. To investigate this, we applied microarray technology to identify gene expression changes in hPDLCs transfected with FDC-SP and then clustered them according to their biological functions. We firstly established a recombinant lentiviral vector containing FDC-SP and obtained safe and efficient FDC-SP overexpression in human periodontal ligament cells (hPDLCs). After that, we applied Agilent Whole Human Genome Oligo Microarray (4×44K) to identify differentially expressed genes between empty vector-transfected hPDLCs and FDC-SP -transfected ones and then clustered them according to their biological functions. 3 independent experiments were performed and the empty vector-transfected hPDLCs were used as control.
Project description:We used microarrays to detect the differences in gene-expression of the periontal ligament between patients with healthy periodontal ligament and patients with periodontitis Overall design: RNA was extracted directly from the middle third of the human periodontal ligament
Project description: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) revealed markedly high expression of chemokine (CXC motif) ligand 12 (CXCL12) in the HPDLFs, which plays an important role in the migration of mesenchymal stem cells (MSCs). The function of CXCL12 in the periodontal ligament was investigated in HPDLFs. CXCL12 in HPDLFs and HDFs was examined by microarray, RT-PCR, qRT-PCR and ELISA. It was also immunohistochemically examined in the PDL in vivo. Chemotactic ability of CXCL12 was evaluated both in PDLFs and HDFs with migration assay of MSCs. The expression of CXCL12 in the HPDLFs was much higher than that in HDFs in vitro. CXCL12 was localized in fibroblasts and extracellular matrix in the PDL in rats. 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. The results suggested that PDLFs are able to synthesize and secrete CXCL12 protein, and that CXCL12 induces migration of MSCs in the PDL in order to maintain rapid turnover of the PDL. The objective of this study was to investigate the function of CXCL12 in the PDL with rapid turnover.Microarray analysis was performed using a Whole Human Genome 8x60K (Agilent Technologies, Tokyo, Japan) containing approximately 44,000 transcripts. According to the manufacturer’s protocol, total RNAs from HPDLFs and HDFs were labeled with Cy3 and hybridized on the microarray. The hybridization data for HPDLFs were compared with data for HDFs.
Project description:The pre-occlusal eruption brings the rat molars into functional occlusion, which implicates tensional strains during mastication. We hypothesized that upon establishment of occlusion, the periodontal ligament undergoes cell and extracellular matrix maturation to adopt to this mechanical function. We thus aimed to characterize the protein content and changes in expression levels of tensionally relevant extracellular matrix components in the periodontal ligament between the eruption and newly established occlusion in rat molars. Twelve Wistar male rats were divided into 3 groups based on eruption and occlusal stages: covering the pre-occlusal stages at time of eruption, the first day of occlusion and 1 week after occlusion. We employed laser capture microdissection to obtain samples of the periodontal ligament at three regions, cervical, apical and subapical. The proteome was screened with Tandem Mass Tag 10-plexTM mass spectrometry and the expression of key proteins were confirmed by immunofluorescence. Differential expression of matrisome proteins was seen in the cervical and the apical region. Downregulation of pro-metabolic proteins, such as apolipoproteins implicated in lipid transport was observed. Alpha-fetoprotein, a stem cell marker, was also downregulated indicating cell differentiation and PDL maturation. Upregulated proteins were components of the extracellular matrix, involving several proteoglycans and glycoproteins and the matrisome was thus further analyzed. Periostin appeared around collagen α-1 (III) fibers and its expression was particularly strong on Sharpey’s fibers. This co-localization coincided with organization of collagen fibers in direction of the occlusal forces. Establishment of occlusion coincides with cellular differentiation and the maturation of the extracellular matrix of the periodontal ligament, as seen by downregulation of the stem cell marker Alpha-fetoprotein and apolipoproteins, and the progressive accumulation of collagen type III fibers, proteoglycans, glycoproteins. The increase in collagen fiber associates periostin may reflect a physiological response to enforce cell-ECM contacts during PDL maturation.
Project description:This study describes the discovery of the gene responsible for differentiation of stem cells into ligament tissue. This important finding may lead to the development of treatments for gonarthrosis, rupture of the cruciate ligament and periodontal ligament, and ossification of the posterior longitudinal ligament. This study describes the discovery of the gene (A) responsible for differentiation of stem cells into ligament tissue. The transfection of this gene into mouse mesenchymal stem cells resulted in the formation of ligament-like connective tissue composed of parallel fibres. We performed microarray analysis of four samples: stem cells (sample1), ligament-like tissue from stem cells transfected with A (sample 4), ligament tissue from A-transgenic mice (sample 2) , and ligament tissue from wild type mice (sample 3).