Biomedical subjects

Giordano Stabellini

Publications and source records attributed to Giordano Stabellini.

At least 19 recordsLinked to original sources

PubMed2006

Desmoid and fibroma tumors differently respond to TGFbeta(1) stimulus and ECM macromolecule accumulation.

Desmoid and fibroma tumours are characterized by cell proliferation, glycosaminoglycan and collagen fibre accumulation, high levels of transforming growth factor beta(1) (TGFbeta(1)) and different patterns of tissue infiltration. TGFbeta(1) is related to extracellular matrix (ECM) composition which, in turn, regulates cell functions and cell migration. In this study we report changes in cell proliferation, glycosaminoglycan (GAG) and collagen synthesis, TGFbeta(1) mRNA expression and fibronectin levels in normal, desmoid and fibroma fibroblast cultures before and after TGFbeta(1) stimulation. Our data showed cell proliferation, GAG and collagen synthesis, transforming growth factor beta(1) mRNA expression and fibronectin levels were significantly higher in desmoid than in fibroma cultures. TGFbeta(1) treatment had no effect on cell proliferation, but increased TGFbeta(1) mRNA expression, GAG, fibronectin and collagen synthesis in desmoid and fibroma fibroblasts. Its effects were more marked in desmoid cells. Fibronectin favours cell migration, while changes in GAG composition alter cell behaviour and ECM organization. In conclusion our data suggest that the different patterns of infiltration in desmoid and fibroma tumours are due to changes in ECM components and cell-ECM interactions which can be ascribed to altered TGFbeta(1) mRNA expression and TGFbeta(1) activity.

Blotting, Northern↗

PubMed2005

Human desmoid fibroblasts: matrix metalloproteinases, their inhibitors and modulation by Toremifene.

BACKGROUND: Desmoid tumour is a benign, non metastasising neoplasm characterised by an elevated deposition of organic macromolecules in the extracellular matrix (ECM). The matrix metalloproteinases (MMPs) are a family of zinc-dependent proteinases involved in the degradation of ECM macromolecules. The MMPs and their natural inhibitors (TIMPs) have been implicated in tumour growth, invasion and metastasis. In this study we provide evidence that the in vitro cultured cell line from desmoid tumour accumulates more collagen fibres in the ECM than healthy fibroblasts. METHODS: We investigated collagen accumulation by 3H-thymidine incorporation, MMP expression by substrate gel zymography and TIMP expression by Western blot analysis. RESULTS: Desmoid fibroblasts showed a reduction in MMP activity and an increase of type I and III collagen and TIMPs compared to normal fibroblasts. CONCLUSION: The increase in collagen in desmoid fibroblasts was due to inhibited collagen degradation (reduction of MMP activity) rather than to increased collagen synthesis. Adding toremifene, an anti-estrogen triphenylethylene derivate, to desmoid fibroblasts reduced collagen accumulation by decreasing mRNA expression and increasing collagen degradation.

Antineoplastic Agents, Hormonal↗

PubMed2005

Effect of Vitamin C on pre-osteoblast gene expression.

Ascorbic acid (AA), also known as Vitamin C, is a cofactor required for the function of several hydroxylases. It is not synthesised in humans and has to be provided by diet. Its absence is responsible for scurvy, a condition related to the defective synthesis of collagen by the reduced function of prolylhydroxylase. AA is also a risk factor for periodontal disease. Recently, it has been shown that AA induces embryonic stem cells to differentiate into osteoblasts. The mechanism by which AA sustains pre-osteoblast proliferation and commitment is mediated through the synthesis of collagen type I, interaction with alpha2- and beta1-integrin, activation of the mitogen-activated protein kinase pathway, and phosphorylation of osteoblast-specific transcription factors. However, the multifunctional role of AA is not fully elucidated. MC3T3-E1 mouse calvaria-derived cell line is a well-defined in vitro model of pre-osteoblast differentiation, and AA is essential for the proliferation and differentiation of MC3T3-E1. By using DNA micro-arrays containing 15,000 genes, we identified several genes in MC3T3-E1 cultured with AA for 24h whose expression was significantly up or downregulated. The differentially expressed genes covered a broad range of functional activities: (1) cell growth; (2) metabolism; (3) morphogenesis; (4) cell death; (5) cell communication. The data reported are, to our knowledge, the first genetic portrait of early stage stimulation of pre-osteoblasts by AA, and may be relevant to better understand the molecular mechanism of pre-osteoblast proliferation and commitment. Elucidation of the molecular mechanism has important clinical implications because it may facilitate the correct use of AA to accelerate bone regeneration.

3T3 Cells↗

PubMed2005

Changes in polyamines, c-myc and c-fos gene expression in osteoblast-like cells exposed to pulsed electromagnetic fields.

Pulsed electromagnetic field (PEMF) stimulation promotes the healing of fractures in humans, though its effect is little known. The processes of tissue repair include protein synthesis and cell differentiation. The polyamines (PA) are compounds playing a relevant role in both protein synthesis processes and cell differentiation through c-myc and c-fos gene activation. Since several studies have demonstrated that PEMF acts on embryonic bone cells, human osteoblast-like cells and osteosarcoma TE-85 cell line, in this study we analyzed the effect on cell PAs, proliferation, and c-myc and c-fos gene expression of MG-63 human osteoblast-like cell cultures exposed to a clinically useful PEMF. The cells were grown in medium with 0.5 or 10% fetal calf serum (FCS). c-myc and c-fos gene expressions were determined by RT-PCR. Putrescine (PUT), spermidine (SPD), or spermine (SPM) levels were evaluated by HPLC. [(3)H]-thymidine was added to cultures for DNA analysis. The PEMF increased [(3)H]-thymidine incorporation (P < or = .01), while PUT decreased after treatment (P < or = .01); SPM and SPD were not significantly affected. c-myc was activated after 1 h and downregulated thereafter, while c-fos mRNA levels increased after 0.5 h and then decreased. PUT, SPD, SPM trends, and [(3)H]-thymidine incorporation were significantly related to PEMF treatment. These results indicate that exposure to PEMF exerts biological effects on the intracellular PUT of MG-63 cells and DNA synthesis, influencing the genes encoding c-myc and c-fos gene expression. These observations provide evidence that in vitro PEMF affects the mechanisms involved in cell proliferation and differentiation.

Cell Differentiation↗

PubMed2005

Differential effect of Cyclosporin A and FK506 on SPARC mRNA expression by human gingival fibroblasts.

BACKGROUND: Secreted protein acidic and rich in cysteine (SPARC) is a glycoprotein that mediates cell-matrix interactions. In adults, its expression is mostly limited to tissue undergoing remodeling. During the development of Cyclosporin A (CsA)-induced gingival overgrowth (GO) a remodeling of the connective compartment occurs. By contrast, clinical trials showed that FK506 is not related to GO. SPARC expression and its involvement in GO is unknown. Our aim was, therefore, to analyze the effect of CsA and FK506 on SPARC gene expression. METHODS: Cultured human gingival fibroblasts were incubated with CsA, FK506 or with their vehicle (VH) for 24, 48 and 72 h. SPARC gene expression was determined by RT-PCR. RESULTS: SPARC mRNA levels tended to increase 72 h after CsA treatment, whilst they are undetectable in FK506-treated fibroblasts, compared to VH. CONCLUSION: This gene expression profile is consistent with the involvement of SPARC in the mechanisms leading to the development of CsA-induced GO. By contrast, the undetectable SPARC mRNA levels in FK506-treated fibroblasts suggest that FK506 may be associated with a role of ECM stabilization, that does not induce GO.

Adult↗

PubMed2005

Genetic portrait of mild and severe lingual dysplasia.

Squamous cell carcinoma is the most frequent malignant tumor of the oral cavity and often arises from premalignant lesions. Traditional methods used by the pathologist are subjective and lack the sensitivity to predict accurately which precancers may progress with time. Therefore, it is important to search for markers that may identify progression of premalignant lesions. Microarray technology can be use with this aim. Here, we define the genetic expression profile of lingual dysplasia (DS) progression. By using cDNA microarray containing 19.2K clones and a baseline of 11 normal tissues, we compared 5 mild and 4 severe DS. We identified 270 genes differentially expressed in normal tissue vs. mild DS (i.e. 161 up- and 109 down-regulated) and 181 genes differentially expressed in mild vs. severe DS (i.e. 63 up- and 118 down-regulated). The described genes cover a broad range of functional activities: (a) anti-oxidative, (b) DNA-repair, (c) inflammatory response, (d) cell-adhesion/mobility, (e) extracellular matrix depolymerization, and (f) cell-cycle regulation. The data reported better define DS progression and can help in classifying premalignant lesions.

Adult↗

PubMed2005

An in vitro model for dissecting distraction osteogenesis.

Distraction osteogenesis (DO) is a mechanotransduction process capable of generating viable osseous tissue by the gradual separation of osteotomized bone edges. Several variables are implicated in DO: magnitude of mechanical strain, distraction rate, and type of distracted bone. The combination of these factors acts on different types of cells inducing apoptosis, cell proliferation, and differentiation. The elucidation of the molecular mechanisms has important clinical implications because it may facilitate the use of recombinant proteins or gene therapy to accelerate bone regeneration. Previous reports have analyzed several molecules such as extracellular matrix proteins, cytokines, bone morphogenetic proteins, hormones, and angiogenic factors. Moreover, a single protein can have multifunctional roles. With such a huge number of mechanical, histologic, cellular, and molecular variables, there is the need to have a cell culture model that enables the selection of the effect of a specific strength to a single cell type at different time points and with or without cytokines. The analysis of the genetic profiling of a cell line cultured on an equibiaxial stretch device has such characteristic. Because there is a recruitment and commitment of preosteoblastic cells during bone lengthening and no previous report has focus on them, the authors used a preosteoblast MC3T3-E1 cell line to detect the early molecular effects of distraction on mesenchymal cells. By using DNA microarrays containing 15,000 clones, the authors identified several genes the expression of which was significantly up- or down-regulated. The differentially expressed genes cover a broad range of biological processes: cell growth, metabolism, morphogenesis, cell communication, response to stress, and cell death. The data reported are the first genetic portrait of stretched preosteoblasts. They can be relevant in the better understanding of the molecular mechanism of DO and as a model for comparing the effect of distraction on different cell lines and primary cultures, rate and strength of distraction, and with or without cytokines.

3T3 Cells↗

PubMed2005

Immunosuppression and gingival overgrowth: gene and protein expression profiles of collagen turnover in FK506-treated human gingival fibroblasts.

AIM: FK506 is an immunosuppressive agent that, unlike cyclosporin A (CsA), does not induce gingival overgrowth (GO). CsA-induced GO is caused by quantitative modifications of the extracellular matrix components, particularly collagen (COL). Up to now, clinical trials have only investigated FK506 in relation with GO, so we aimed at analysing the effect of FK506 on COL turnover using a molecular approach, to evaluate the expression of genes and proteins related to this process. MATERIALS AND METHODS: Human gingival fibroblasts were incubated with FK506 or its vehicle (VH) for 24, 48 and 72 h. COL type I (COL-I), matrix metalloproteinases (MMP)-1 and 2, tissue inhibitor of MMP (TIMP)-1 and transforming growth factor (TGF)-beta1 mRNA were assayed by Reverse transcriptase polymerase chain reaction; COL-I protein levels were determined by dot blot, MMP-1 and MMP-2 activity by zymography. RESULTS: Fibroblast proliferation decreased 48 and 72 h after treatment. COL-I gene and protein expression, TGF-beta1 and TIMP-1 mRNA levels were not significantly affected, whereas MMP-1 gene and protein expression and MMP-2 mRNA levels rose significantly in treated fibroblasts compared with VH. CONCLUSIONS: These findings suggest that increased MMP-1 gene and protein expression may be important for regulating COL-I homeostasis in the gingival connective compartment of FK506-immunosuppressed subjects.

Adult↗

PubMed2005

Morphological and molecular analysis of idiopathic gingival fibromatosis: a case report.

AIM: We analyse a case of idiopathic gingival overgrowth using morphological and molecular methods. As this overgrowth involves collagen accumulation in the gingival connective tissue, we measured the collagen turnover to clarify the pathogenic mechanisms potentially involved. MATERIALS AND METHODS: The patient was a 29-year-old Italian woman with enlargement of the gingivae throughout the entire mandible and maxilla. Morphological analyses were carried out on haematoxylin-eosin and Sirius red-stained paraffin-embedded gingival sections. mRNA levels of collagen type I and III, matrix metalloproteinase (MMP)-1, transforming growth factor-beta1 and lysyl hydroxylase (LH)2b were determined by RT-PCR on cultured gingival fibroblasts and compared with healthy control fibroblasts. Interstitial collagen and MMP-1 content in the supernatants were assessed, respectively, by dot blot and SDS zymography. RESULTS AND CONCLUSIONS: In Sirius red-stained sections of the patient's overgrown gingivae, interstitial collagen content was 29% higher than controls. Her gingival fibroblasts had higher collagen type I, MMP-1 and LH2b gene expression and unmodified interstitial collagen, type I protein levels in the supernatants. These findings would seem to suggest that in this case collagen accumulation in the gingival connective tissue was not associated with increased synthesis and decreased degradation.

Adult↗

PubMed2005

Depletion of polyamines and increase of transforming growth factor-beta1, c-myc, collagen-type I, matrix metalloproteinase-1, and metalloproteinase-2 mRNA in primary human gingival fibroblasts.

BACKGROUND: The polyamines spermidine, spermine, and putrescine are known to be deeply linked with growth processes, gene expression, and extracellular matrix synthesis. Their cellular content depends primarily on the activity of the enzyme ornithine decarboxylase. High levels of ornithine decarboxylase and polyamines have been found in proliferative, inflammatory, and neoplastic pathologies of the oral cavity and in gingival fluid. Difluoromethylornithine (DFMO) selectively inhibits ornithine decarboxylase, thus depleting polyamine content and preventing cell proliferation and synthesis activity. The aim of this study was to investigate whether DFMO treatment could modify the genes involved in cell proliferation and extracellular matrix turnover. METHODS: Fibroblasts derived from non-inflamed gingiva were maintained in Dulbecco's modified Eagle's medium (DMEM) plus alpha-difluoromethylornithine for 4 days. At 0, 24, 48, 72, and 96 hours cell number was assessed, polyamine levels were quantified with high performance liquid chromatography (HPLC) method, and transforming growth factor-beta1 (TGF-beta1), c-myc, matrix metalloproteinases (MMP)-1 and 2, collagen type I (COL-I) and tissue inhibitor of matrix metalloproteinases (TIMP)-1 were evaluated by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Fibroblasts treated with DFMO significantly decreased cell proliferation, ornithine decarboxylase activity, and putrescine levels at all treatment times, spermidine after 72 and 96 hours, and spermine after 96 hours of culture. Total polyamines decreased (P < or =0.01) at 96 hours after DFMO treatment, while c-myc, TGF-beta1, MMP-1 and 2, COL-I mRNA significantly increased. Conversely, TIMP-1 did not show any significant change. The polyamines trend was not correlated to c-myc, TGF-beta1, MMP-1 and -2, and TIMP-1 mRNA levels. Transforming growth factor-beta1 and c-myc mRNA expression were related and correlated to MMP-1 and 2, COL-I and TIMP-1 mRNA trend after DFMO treatment. CONCLUSIONS: Our data show that as the polyamine content decreases, TGF-beta1, c-myc, MMP-1 and -2, and COL-I mRNA levels increase, therefore a negative regulatory role of the polyamines on the mRNA expression could be suggested.

Adult↗

PubMed2004

Survivin as prognostic factor in squamous cell carcinoma of the oral cavity.

A series of 78 cases of oral squamous cell carcinoma was analysed by immunohistochemistry for expression of survivin, a recent apoptosis inhibitor. All cases were positive for survivin expression and were divided into two groups using a system of scores. Disease-specific survival curves were calculated according to Kaplan-Meier algorithm, and log rank test was used to compare survival curves. Then, Cox regression analysis was applied to determine the single contribution of covariates on survival rate. So, Cox analysis allowed us to detect the variables most associated to survival. Among the studied variables, such as grade of differentiation, tumor size, stage, recurrence of disease, lymph node presence, only stage and recurrence of disease were predictors of outcome; however, when we analyzed the survival without considering recurrence (that was the stronger predictor of death), a stepwise Cox analysis showed that Survivin, stage and grade of differentiation are significantly associated to survival, with a higher value for Survivin. These data suggest that survivin expression may identify cases of oral squamous cell carcinoma with more aggressive and invasive phenotype and, therefore, could influence the decision for the therapy at the time of diagnosis.

Adolescent↗

PubMed2004

Calcium sulfate: analysis of MG63 osteoblast-like cell response by means of a microarray technology.

Calcium sulfate (CaS) is an highly biocompatible material that has the characteristic of being one of the simplest as well as one of the synthetic bone-like graft with the longest clinical history, spanning more than 100 years. Solidified or crystallized CaS is very osteogenic in vivo. As the surface CaS dissolves in body fluid, the calcium ions form calcium phosphate that reprecipitates on the surface forming an osteoblast "friendly" environment. How this "friendly" environment alters osteoblast activity to promote bone formation is poorly understood. We therefore attempted to address this question by using microarray techniques to identified genes that are differently regulated in osteoblasts exposed to CaS. By using DNA microarrays containing 19,200 genes, we identified in osteoblast-like cells line (MG-63) cultured with CaS (Surgiplaster, Classimplant, Roma, Italy) several genes that expression was significantly upregulated. The differentially expressed genes cover a broad range of functional activities: (a) immunity, (b) lysosomal enzymes production, (c) cell cycle regulation, (d) and signaling transduction. It was also possible to detect some genes whose function is unknown. The data reported are, to our knowledge, the first genetic portrait of CaS effects. They can be relevant to better understand the molecular mechanism of bone regeneration and as a model for comparing other materials with similar clinical effects.

Calcium Sulfate↗

PubMed2004

Effect of cyclosporin A on human gingival fibroblast collagen turnover in relation to the development of gingival overgrowth: an in vitro study.

In a significant number of cases (25-81%) immunosuppressant treatment with cyclosporin A (CsA) is associated with gingival overgrowth, seriously interfering with the functions of mastication and speech. In CsA-induced gingival enlargement, quantitative modifications of the extracellular matrix components occur, and collagen (COL) metabolism and matrix metalloproteinases (MMPs) have been suggested as being the main targets. Since the mechanisms at the basis of CsA-induced gingival overgrowth are not yet completely understood, our aim was to analyze the effect of CsA on COL turnover in cultured human gingival fibroblasts. Cultured human gingival fibroblasts from four healthy volunteers were incubated with CsA (800 ng/ml) or with its vehicle (VH) for variable intervals of time (24, 48, 72 h). Fibroblast morphology was studied by light and electron microscope. Collagen type I (COL-I), MMP-1, MMP-2, TIMP-1 and TGF-beta1 mRNA were determined by RT-PCR; COL-I and MMP-1 by dot blot, and MMP-2 by zymography. Our results evidenced an up-regulation of COL-I and TGF-beta1 gene expression 72 h after CsA treatment. MMP-1, MMP-2 and TIMP-1 mRNA levels are affected but not significantly. Protein analysis revealed COL-I increase at all the considered times and, 72 h after CsA treatment, reduced collagenolytic levels. Our data suggest that COL accumulation during CsA-induced gingival overgrowth may be mainly sustained by an altered COL-I degradation due to decreased MMP-1 activity. However, interindividual differences of collagenase levels after CsA treatment suggest that a genetic predisposition to develop gingival overgrowth may be relevant.

Cells, Cultured↗

PubMed2004

Ultrastructural changes in Langerhans cells in gingival overgrowth in cyclosporin A-treated renal transplant patients.

AIM: Our research was focused on the ultrastructural features of gingival epithelium in kidney transplant patients and, in particular, on Langerhans cells, with the aim of verifying whether ultrastructural modifications might explain gingival overgrowth. METHODS: Using electron microscopy and immunohistochemical S100 staining at optical microscopy, we examined gingival samples obtained from 18 kidney transplant patients who presented with gingival overgrowth following cyclosporin A treatment. RESULTS: The hyperkeratosis shown by the epithelium, and especially the absence of Birbeck granules in the Langerhans cells observed in serial sections, lead us to correlate these data to an immunodeficiency which affects the epithelium in the complex mechanism determining overgrowth. CONCLUSIONS: In our previous studies we attributed the responsibility of overgrowth to the connective tissue alone. However, in the light of the present results, we cannot exclude a contribution of the epithelium to gingival overgrowth.

Adult↗

PubMed2004

Genetic profiling of granular cell myoblastoma.

Granular cell tumor (GCT), or granular cell myoblastoma, is a relatively uncommon lesion of the soft tissues. It can occur in any organ, and the tongue is more often affected. GCT has unknown etiology, uncertain histogenesis, and a not always benign nature. Benign myoblastomas are the great majority, but rare malignant lesions have been reported. To have more information regarding the genetic events involved in GCT, the authors decided to perform an expression profile. A sample was derived from a surgically resected GCT of the tongue. RNA extracted from normal tongue (mucosa plus muscle) was used as control. By using DNA microarrays containing 19,200 genes, the authors identified several genes for which expression was significantly up- or down-regulated. The differentially expressed genes cover a broad range of functional activities: (1) signal transduction, (2) cell cycle regulation, and (3) cytoskeleton organization. It was also possible to detect some genes whose function is unknown. The data reported are, to the authors' knowledge, the first genetic portrait of GCT. Mutations in some of the described genes are related to neural alterations and mental diseases, and this fact supports the idea of a neural origin of myoblastoma. Several markers have been identified that will help in identifying the biological behavior (when malignant lesions will be described), as well as the gene whose products could be potentially disease-specific targets for therapy.

Cell Cycle Proteins↗

PubMed2003

Biocompatibility of collagen membranes crosslinked with glutaraldehyde or diphenylphosphoryl azide: an in vitro study.

Crosslinking of collagen biomaterials increases their resistance to degradation in vivo. Glutaraldehyde (GA) is normally used to crosslink collagen biomaterial, but is often cytotoxic. Diphenylphosphoryl azide (DPPA) has recently been proposed as reagent, but little is known about its effects on cell behavior. In this study, we determined which collagen membrane was the most biocompatible: Paroguide which is crosslinked with DPPA and contains chondroitin sulfate; Opocrin which is crosslinked with DPPA; Biomed Extend which is crosslinked with GA; and Bio-Gide which is left untreated. Cell proliferation and extracellular matrix macromolecule deposition were evaluated in human fibroblasts cultured on the membranes. The GA-crosslinked Biomed Extend membrane and the not-crosslinked Bio-Gide membrane reduced cell growth and collagen secretion compared with DPPA-crosslinked biomembranes. When Paroguide and Opocrin were compared, better results were obtained with Paroguide. The greatest amount of transforming growth factor beta1, a growth factor involved in extracellular matrix macromolecule accumulation and in tissue regeneration, was produced by cells cultured on Paroguide, with Opocrin second. Our data suggest that the DPPA method is more biocompatible than the GA for crosslinking collagen biomaterials and that membranes made of collagen plus chondroitin sulfate are better than membranes made of pure collagen.

Azides↗

PubMed2003

Effects of interleukin-1beta on chondroblast viability and extracellular matrix changes in bovine articular cartilage explants.

Osteoarthritis is a degenerative disease of joint cartilage, characterized by the progressive and permanent degeneration of cartilage due to an imbalance in normal extracellular matrix turnover. Interleukin-1 beta is a proinflammatory agent, which is present in an elevated amount in osteoarthritic cartilage, and is thought to play a decisive role in osteoarthritis. Interleukin-1 beta acts as an important mediator of extracellular matrix changes where its activity is regulated by glycosaminoglycan composition. The aim of this study was to investigate the extracellular matrix changes in bovine cartilage explants following interleukin-1 beta treatment by morphological, histochemical and biochemical methods. Interleukin-1 beta stimulated the release of matrix sulfated proteoglycans in the culture medium, and significantly inhibited sulfated proteoglycan synthesis. These events were associated to a strong stimulation of nitric oxide production. Interleukin-1 beta-treated cartilage showed evident collagen fibers around the chondrocytes, together with diminished glycosaminoglycan sulfate content in the extracellular matrix of the explants. Moreover, the ultrastructure and viability of cells did not change in treated cartilage. Our data show that interleukin-1 beta modifies the ECM turnover without toxic effect on chondrocytes.

Animals↗

PubMed2003

Cross-talk between interleukin-6 and transforming growth factor-beta3 regulates extracellular matrix production by human fibroblasts from subjects with non-syndromic cleft lip and palate.

BACKGROUND: Transforming growth factor-beta (TGF-beta) interference with interleukin 6 (IL-6) activity and the role of the latter in early human embryonic development prompted us to examine the effects IL-6 on matrix synthesis and the effects of TGF-beta3 on IL-6 expression human cleft lip and palate (CLP) fibroblasts. METHODS: Collagen and glycosaminoglycan (GAG) synthesis were determined by radiolabeled precursors and biglycan expression by Northern blotting before and after adding IL-6. The effects of TGF-beta3 on IL-6 production were assayed by evaluating IL-6 transcript by Northern blotting and IL-6 protein secretion by enzyme-linked immunosorbent assay. RESULTS: The results showed that IL-6 elicited an inhibitory effect on collagen and GAG levels in CLP fibroblasts by lowering hyaluronan and dermatan sulfate secretion. IL-6 up-regulated biglycan expression, but less strongly than TGF-beta3. TGF-beta3 significantly down-regulated IL-6 transcript and secretion in CLP fibroblasts. CONCLUSIONS: These data suggest the increase in matrix components that characterize the CLP fibroblast phenotype might be due to a concerted TGF-beta3-IL-6 action. We hypothesize changes in cross-talk between TGF-beta3 and IL-6 signal transduction pathways are involved in the induction of cleft palate.

Analysis of Variance↗