Tumor Necrosis Factor-α Inhibits Transforming Growth Factor-β–Stimulated Myofibroblastic Differentiation and Extracellular Matrix Production in Human Gingival Fibroblasts

TNF-α promotes expression of inflammatory factors by upregulating nicotinamide adenine dinucleotide phosphate oxidase-2 expression in human gingival fibroblasts

Background/purpose

Periodontitis is a chronic infectious disease. The oxidative stress environment can cause or exacerbate the inflammation in periodontitis. Nicotinamide adenine dinucleotide phosphate oxidase (NOX) may be the most important source of reactive oxygen species (ROS) in periodontal tissues. The pathological mechanism of periodontitis may be related to the increased ROS caused by enhanced NOX activity. The purpose was to investigate the effect of tumor necrosis factor (TNF-α) on inflammatory cytokines and ROS, and the role of NOX-2 in human gingival fibroblasts (HGFs).

Materials and methods

HGFs were cultured and divided into the normal control group (NC group) and the inflammatory model group (TNF-α group) induced by 10 ng/ml TNF-α. Thereafter, NOX-2 siRNA was used to knock down NOX-2 gene expression. Quantitative real-time PCR was applied to detect IL-6, MCP-1, and NOX-2 mRNA levels. The levels of IL-6 and MCP-1 protein were examined by ELISA. The level of NOX-2 was evaluated by Western blot. ROS expression was measured by the fluorescence microplate.

Results

The mRNA and protein expression levels of IL-6, MCP-1, and NOX-2 were significantly increased, and the expression of ROS was significantly elevated in response to 10 ng/ml TNF-α. Compared with the si-NC group, the mRNA and protein expression levels of IL-6 and MCP-1 were significantly down-regulated and ROS expression was significantly decreased in the si-NOX2 group stimulated by 10 ng/ml TNF-α.

Conclusion

TNF-α promotes the expression of NOX-2 in human gingival fibroblasts and enhances the expression of inflammatory factors and ROS in human gingival fibroblasts through the upregulation of NOX-2 partly.

Fibroblast activation in response to TGFβ1 is modulated by co-culture with endothelial cells in a vascular organ-on-chip platform

Background: Tissue fibrosis is a major healthcare burden that affects various organs in the body for which no effective treatments exist. An underlying, emerging theme across organs and tissue types at early stages of fibrosis is the activation of pericytes and/or fibroblasts in the perivascular space. In hepatic tissue, it is well known that liver sinusoidal endothelial cells (EC) help maintain the quiescence of stellate cells, but whether this phenomenon holds true for other endothelial and perivascular cell types is not well studied. Methods: The goal of this work was to develop an organ-on-chip microvascular model to study the effect of EC co-culture on the activation of perivascular cells perturbed by the pro-fibrotic factor TGFβ1. A high-throughput microfluidic platform, PREDICT96, that was capable of imparting physiologically relevant fluid shear stress on the cultured endothelium was utilized. Results: We first studied the activation response of several perivascular cell types and selected a cell source, human dermal fibroblasts, that exhibited medium-level activation in response to TGFβ1. We also demonstrated that the PREDICT96 high flow pump triggered changes in select shear-responsive factors in human EC. We then found that the activation response of fibroblasts was significantly blunted in co-culture with EC compared to fibroblast mono-cultures. Subsequent studies with conditioned media demonstrated that EC-secreted factors play at least a partial role in suppressing the activation response. A Luminex panel and single cell RNA-sequencing study provided additional insight into potential EC-derived factors that could influence fibroblast activation. Conclusion: Overall, our findings showed that EC can reduce myofibroblast activation of perivascular cells in response to TGFβ1. Further exploration of EC-derived factors as potential therapeutic targets in fibrosis is warranted.

Effect of Tumor Necrosis Factor Alpha (TNF-α) -308 and -1031 Gene Polymorphisms on Periodontitis among Saudi Subjects

Objectives

Materials and methods

Results

Conclusion

Follicular dendritic cell differentiation is associated with distinct synovial pathotype signatures in rheumatoid arthritis

Follicular dendritic cells (FDCs) fundamentally contribute to the formation of synovial ectopic lymphoid-like structures in rheumatoid arthritis (RA) which is associated with poor clinical prognosis. Despite this critical role, regulation of FDC development in the RA synovium and its correlation with synovial pathotype differentiation remained largely unknown. Here, we demonstrate that CNA.42⁺ FDCs distinctively express the pericyte/fibroblast-associated markers PDGFR-β, NG2, and Thy-1 in the synovial perivascular space but not in established follicles. In addition, synovial RNA-Seq analysis revealed that expression of the perivascular FDC markers was strongly correlated with PDGF-BB and fibroid synovitis, whereas TNF-α/LT-β was significantly associated with lymphoid synovitis and expression of CR1, CR2, and FcγRIIB characteristic of mature FDCs in lymphoid follicles. Moreover, PDGF-BB induced CNA.42⁺ FDC differentiation and CXCL13 secretion from NG2⁺ synovial pericytes, and together with TNF-α/LT-β conversely regulated early and late FDC differentiation genes in unsorted RA synovial fibroblasts (RASF) and this was confirmed in flow sorted stromal cell subsets. Furthermore, RASF TNF-αR expression was upregulated by TNF-α/LT-β and PDGF-BB; and TNF-α/LT-β-activated RASF retained ICs and induced B cell activation in in vitro germinal center reactions typical of FDCs. Additionally, FDCs trapped peptidyl citrulline, and strongly correlated with IL-6 expression, and plasma cell, B cell, and T cell infiltration of the RA synovium. Moreover, synovial FDCs were significantly associated with RA disease activity and radiographic features of tissue damage. To the best of our knowledge, this is the first report describing the reciprocal interaction between PDGF-BB and TNF-α/LT-β in synovial FDC development and evolution of RA histological pathotypes. Selective targeting of this interplay could inhibit FDC differentiation and potentially ameliorate RA in clinically severe and drug-resistant patients.

Transcript levels of cytokine coding genes in peripheral blood and tissues of patients with periodontitis

Periodontal diseases are common conditions in almost all age groups and a public health problem. Numerous risk factors have been demonstrated for this condition. The main mechanism of tissue destruction in the periodontitis is the functional interactions between microbial pathogens and host immune responses, thus cytokines have crucial roles in the pathogenesis periodontitis. Our previous study has demonstrated the susceptibility role of HLA-DRB1*04 allele in development of this disease. So, the individuals who were positive for HLA-DRB1*04 allele were excluded. We aimed to appraise the function of cytokines in the pathogenesis of periodontitis via assessment of tissue and blood levels of a number of cytokine coding genes, namely IL-1B, CXCL8, IL-17, IFNG, TGFB and TNFA1. Expressions of IFNG, IL-17, TGFB and TNFA1 were significantly higher in the peripheral blood of individuals with periodontitis compared with unaffected persons (Posterior beta = 1.91, P value = 0.043; Posterior beta = 1.84, P value = 0.033; Posterior beta = 0.713, P value = 0.009 and Posterior beta = 2.85, P value = 0.001, respectively). Moreover, expression of IL-17 was higher in females compared with males (Posterior beta = 1.47, P value = 0.036). As the interaction effect between gender and group was remarkable for IL-17 expression, we further conducted subgroup analysis within gender group. Expression of IL-17 was higher in male patients compared with unaffected males (Posterior beta = 1.9, P value = 0.048). We did not detect any significant difference in the expression of these cytokines in tissues obtained from affected individuals and unaffected controls. Therefore, our results imply dysregulation of cytokine coding genes in patients with periodontitis and warrant further mechanistical studies.

The cytokine network involved in the host immune response to periodontitis

Periodontitis is an inflammatory disease involving the destruction of both soft and hard tissue in the periodontal region. Although dysbiosis of the local microbial community initiates local inflammation, over-activation of the host immune response directly activates osteoclastic activity and alveolar bone loss. Many studies have reported on the cytokine network involved in periodontitis and its crucial and pleiotropic effect on the recruitment of specific immunocytes, control of pathobionts and induction or suppression of osteoclastic activity. Nonetheless, particularities in the stimulation of pathogens in the oral cavity that lead to the specific and complex periodontal cytokine network are far from clarified. Thus, in this review, we begin with an up-to-date aetiological hypothesis of periodontal disease and summarize the roles of cytokines in the host immune response. In addition, we also summarize the latest cytokine-related therapeutic measures for periodontal disease.

BONE TISSUE BEHAVIOR OF RATS WITH EXPERIMENTAL PERIODONTITIS SUBJECTED TO PHYSICAL EXERCISE

ABSTRACT Introduction: It is possible that physical activity protects the periodontium by mitigating excessive inflammatory response of the individual. There is some evidence from longitudinal studies and a prospective study demonstrating that physically active adults have experienced a decrease in the risk of periodontitis. To date no study has jointly explored the relationship of physical activity and periodontitis using inflammatory biomarkers. Objective: In this regard, the objective was to assess the bone tissue behavior of rats with experimental periodontitis subjected to aquatic exercise. Methods: Twenty-four male Wistar rats were divided into four groups: 1) without periodontitis and without exercise (CS); 2) without periodontitis and with exercise (CE); 3) with periodontitis and without exercise (DPS); 4) with periodontitis and with exercise (DPE). The animals from groups CE and DPE had swimming sessions for four weeks and the DPS and DPE groups were subjected to ligature-induced periodontitis. After 30 days the animals were sacrificed, and had their right and left hemimandibles removed for radiographic and histological analysis. The data obtained were analyzed and evaluated through ANOVA and Tukey tests. Results: Bone loss in the animals from the DPE group was found to be significantly lower (61.7 ± 2.2; p <0.05) than in those from the DPS group (84.5 ± 1.2; p <0.05), while in terms of the number of osteoblasts (DPS=11.0 ± 1.4; DPE=10.7 ± 5.2) and osteocytes (DPS=17.3 ± 3.1; DPE=19.0 ± 4.4), there was no significant decrease (p <0.05) in the groups subjected to experimental periodontitis, regardless of physical exercise. Conclusion: Physical exercise was found to have a protective effect in relation to bone height and did not influence bone density. Level of evidence II; Therapeutic studies - investigation of treatment results.

Role of myofibroblasts in normal and pathological periodontal wound healing

Myofibroblasts represent specific subpopulations of cells with important roles in tissue remodeling in both health and disease. They are not usually found in resting healthy tissues. However, they increase in number during the proliferative phase of wound healing. In these conditions, myofibroblasts secrete and organize different molecular components of the extracellular matrix that with time will reconstitute and hopefully regenerate the damaged tissue. Importantly, these cell populations must be eliminated after wound healing has been completed. However, deficiencies in their differentiation or the persistence of this cell population has been associated with the development of delayed wound healing and fibrosis, respectively. In the present review, we analyze the involvement of myofibroblasts in periodontal wound healing and their potential contribution to tissue homeostasis and disease.

Periostin: A Matricellular Protein With Multiple Functions in Cancer Development and Progression

Tumor microenvironment is considered nowadays as one of the main players in cancer development and progression. Tumor microenvironment is highly complex and consists of non-tumor cells (i.e., cancer-associated fibroblast, endothelial cells, or infiltrating leukocytes) and a large list of extracellular matrix proteins and soluble factors. The way that microenvironment components interact among them and with the tumor cells is very complex and only partially understood. However, it is now clear that these interactions govern and modulate many of the cancer hallmarks such as cell proliferation, the resistance to death, the differentiation state of tumor cells, their ability to migrate and metastasize, and the immune response against tumor cells. One of the microenvironment components that have emerged in the last years with strength is a heterogeneous group of multifaceted proteins grouped under the name of matricellular proteins. Matricellular proteins are a family of non-structural matrix proteins that regulate a variety of biological processes in normal and pathological situations. Many components of this family such as periostin (POSTN), osteopontin (SPP1), or the CNN family of proteins have been shown to regulate key aspect of tumor biology, including proliferation, invasion, matrix remodeling, and dissemination to pre-metastatic niches in distant organs. Matricellular proteins can be produced by tumor cells themselves or by tumor-associated cells, and their synthesis can be affected by intrinsic and/or extrinsic tumor cell factors. In this review, we will focus on the role of POSTN in the development and progression of cancer. We will describe their functions in normal tissues and the mechanisms involved in their regulation. We will analyze the tumors in which their expression is altered and their usefulness as a biomarker of tumor progression. Finally, we will speculate about future directions for research and therapeutic approaches targeting POSTN.

Finasteride accelerates prostate wound healing after thulium laser resection through DHT and AR signalling

OBJECTIVES

Urinary tract infection, urinary frequency, urgency, urodynia and haemorrhage are common post-operative complications of thulium laser resection of the prostate (TmLRP). Our study mainly focuses on the role of finasteride in prostate wound healing through AR signalling.

MATERIALS AND METHODS

TmLRP beagles were randomly distributed into different treatment groups. Serum and intra-prostatic testosterone and DHT level were determined. Histological analysis was conducted to study the re-epithelialization and inflammatory response of the prostatic urethra in each group. We investigated the role of androgen in proliferation and inflammatory response in prostate. In addition, the effects of TNF-α on prostate epithelium and stromal cells were also investigated.

RESULTS

Testosterone and DHT level increased in testosterone group and DHT decreased in finasteride group. Accelerated wound healing of prostatic urethra was observed in the finasteride group. DHT suppressed proliferation of prostate epithelium and enhanced inflammatory response in prostate. We confirmed that DHT enhanced macrophages TNF-α secretion through AR signalling. TNF-α suppressed proliferation of prostate epithelial cells and retarded cell migration. TNF-α also played a pivotal role in suppressing fibroblasts activation and contraction.

CONCLUSION

Testosterone treatment repressed re-epithelialization and wound healing of prostatic urethra. Finasteride treatment may be an effective way to promote prostate re-epithelialization.

Aged blood factors decrease cellular responses associated with delayed gingival wound repair

Aging is a gradual biological process characterized by a decrease in cell and organism functions. Gingival wound healing is one of the impaired processes found in old rats. Here, we studied the in vivo wound healing process using a gingival repair rat model and an in vitro model using human gingival fibroblast for cellular responses associated to wound healing. To do that, we evaluated cell proliferation of both epithelial and connective tissue cells in gingival wounds and found decreased of Ki67 nuclear staining in old rats when compared to their young counterparts. We next evaluated cellular responses of primary gingival fibroblast obtained from young subjects in the presence human blood serum of individuals of different ages. Eighteen to sixty five years old masculine donors were classified into 3 groups: “young” from 18 to 22 years old, “middle-aged” from 30 to 48 years old and “aged” over 50 years old. Cell proliferation, measured through immunofluorescence for Ki67 and flow cytometry for DNA content, was decreased when middle-aged and aged serum was added to gingival fibroblast compared to young serum. Myofibroblastic differentiation, measured through alpha-smooth muscle actin (α-SMA), was stimulated with young but not middle-aged or aged serum both the protein levels and incorporation of α-SMA into actin stress fibers. High levels of PDGF, VEGF, IL-6R were detected in blood serum from young subjects when compared to middle-aged and aged donors. In addition, the pro-inflammatory cytokines MCP-1 and TNF were increased in the serum of aged donors. In old rat wound there is an increased of staining for TNF compared to young wound. Moreover, healthy gingiva (non injury) shows less staining compared to a wound site, suggesting a role in wound healing. Moreover, serum from middle-aged and aged donors was able to stimulate cellular senescence in young cells as determined by the expression of senescence associated beta-galactosidase and histone H2A.X phosphorylated at Ser139. Moreover, we detected an increased frequency of γ-H2A.X-positive cells in aged rat gingival tissues. The present study suggests that serum factors present in middle-aged and aged individuals may be responsible, at least in part, for the altered responses observed during wound healing in aging.

Successful treatment of infliximab in a patient with scleroderma: a case report

RATIONALE

Systemic Scleroderma (SSc) is a rare connective tissue disease clinically characterized by cutaneous sclerosis and variable systemic involvement. No drug is currently available to effectively reverse the fibrotic process in SSc. Previous reports have suggested that the tumor necrosis factor (TNF) antagonists could be useful for the treatment of fibrotic disorders. However, TNFα has long been considered as an antifibrotic cytokine. Whether TNF antagonist is effective for SSc patients needs to be tested.

PATIENT CONCERNS-DIAGNOSIS

Here we report a case with a 2-year history of SSc who was effectively treated with infliximab in our clinic.

INTERVENTIONS

The patient manifested skin thickening, chest tightness and arthralgia. Before admitted to our clinic, he was treated with methylprednisolone, prostacyclin, D-penicillamine and calcium antagonists but without significant improvement of his signs and symptoms. In our clinic, the patient was treated with infliximab.

OUTCOMES

His signs and symptoms were continued improving during the course of treatment. His skin biopsy showed significant reduction in fibroplasia finally.

LESSONS

TNF antagonist is an effective treatment for SSc.

Gingival Crevicular Fluid and Salivary Periostin Levels in Non-Smoker Subjects With Chronic and Aggressive Periodontitis : Periostin Levels in Chronic and Aggressive Periodontitis

Periostin, an extracellular matrix protein functioning as an important structural mediator and adhesion molecule, has been shown to be an important regulator of connective tissue integrity. This study aimed to evaluate the levels of periostin in chronic periodontitis (CP) and aggressive periodontitis (AgP) compared to non-periodontitis (NP). Individuals were submitted to gingival crevicular fluid (GCF) and saliva sampling. Periodontal examination consisted of plaque index (PI), gingival index (GI), probing depth (PD), bleeding on probing (BOP), and clinical attachment level (CAL) measurements. Assays for periostin were performed by an enzyme-linked immunosorbent assay. Periodontitis patients presented more severe clinical indices compared to the NP group (p < 0.001). The mean GCF level of periostin was lowest in the AgP group as compared to the other groups and was lower in the CP group as compared to the NP group (p < 0.001). Increased levels of periostin were observed in the saliva of patients with AgP as compared to the CP and NP groups (p < 0.05). There was a negative relationship between GCF periostin levels and clinical parameters (p < 0.01), whereas a positive correlation was observed between salivary periostin levels and full-mouth GI and CAL scores (p < 0.01). To our knowledge, this is the first report investigating periostin levels in GCF and saliva in aggressive periodontitis. The results suggest that subjects with CP and AgP exhibit a different periostin profile. Periostin in GCF may have a protective role against periodontal disease. Furthermore, salivary periostin concentrations may have a promising diagnostic potential for the aggressive forms of periodontal disease.

Periostin is critical for improving the therapeutic properties of adipocyte-derived stem cells

Periostin is a matricellular protein that is reactivated during tissue damage and repair and has been shown to be a critical regulator of multiple biological pathways involved in the repair of tissue after myocardial infarction, peripheral vascular disease, and skin wounds. The tissue repair properties attributed to periostin make it an ideal candidate to enhance the therapeutic properties of donor cells such as mesenchymal stem cells from adipocyte tissue. In a recent article in Stem Cell Research & Therapy, Qin et al. demonstrated enhanced therapeutic properties of adipocyte-derived stem cells by genetically engineering them to express periostin.

Nifedipine and phenytoin induce matrix synthesis, but not proliferation, in intact human gingival connective tissue ex vivo

Drug-induced gingival enlargement (DIGE) is a fibrotic condition that can be caused by the antihypertensive drug nifedipine and the anti-seizure drug phenytoin, but the molecular etiology of this type of fibrosis is not well understood and the role of confounding factors such as inflammation remains to be fully investigated. The aim of this study was to develop an ex vivo gingival explant system to allow investigation of the effects of nifedipine and phenytoin alone on human gingival tissue. Comparisons were made to the histology of human DIGE tissue retrieved from individuals with DIGE. Increased collagen, fibronectin, and proliferating fibroblasts were evident, but myofibroblasts were not detected in DIGE samples caused by nifedipine and phenytoin. In healthy gingiva cultured in nifedipine or phenytoin-containing media, the number of cells positive for p-SMAD2/3 increased, concomitant with increased CCN2 and periostin immunoreactivity compared to untreated explants. Collagen content assessed through hydroxyproline assays was significantly higher in tissues cultured with either drug compared to control tissues, which was confirmed histologically. Matrix fibronectin levels were also qualitatively greater in tissues treated with either drug. No significant differences in proliferating cells were observed between any of the conditions. Our study demonstrates that nifedipine and phenytoin activate canonical transforming growth factor-beta signaling, CCN2 and periostin expression, as well as increase collagen density, but do not influence cell proliferation or induce myofibroblast differentiation. We conclude that in the absence of confounding variables, nifedipine and phenytoin alter matrix homeostasis in gingival tissue explants ex vivo, and drug administration is a significant factor influencing ECM accumulation in gingival enlargement.

Gingival wound healing: an essential response disturbed by aging?

Gingival wound healing comprises a series of sequential responses that allow the closure of breaches in the masticatory mucosa. This process is of critical importance to prevent the invasion of microbes or other agents into tissues, avoiding the establishment of a chronic infection. Wound healing may also play an important role during cell and tissue reaction to long-term injury, as it may occur during inflammatory responses and cancer. Recent experimental data have shown that gingival wound healing is severely affected by the aging process. These defects may alter distinct phases of the wound-healing process, including epithelial migration, granulation tissue formation, and tissue remodeling. The cellular and molecular defects that may explain these deficiencies include several biological responses such as an increased inflammatory response, altered integrin signaling, reduced growth factor activity, decreased cell proliferation, diminished angiogenesis, reduced collagen synthesis, augmented collagen remodeling, and deterioration of the proliferative and differentiation potential of stem cells. In this review, we explore the cellular and molecular basis of these defects and their possible clinical implications.

Full-Thickness Thermal Injury Delays Wound Closure in a Murine Model

Objective: The contemporary treatment of a full-thickness burn consists of early eschar excision followed by immediate closure of the open wound using autologous skin. However, most animal models study burn wound healing with the persistence of the burn eschar. Our goal is to characterize a murine model of burn eschar excision to study wound closure kinetics. Approach: C57BL/6 male mice were divided into three groups: contact burn, scald burn, or unburned control. Mice were burned at 80°C for 5, 10, or 20 s. After 2 days, the eschar was excised and wound closure was documented until postexcision day 13. Biopsies were examined for structural morphology and α-smooth muscle actin. In a subsequent interval-excision experiment (80°C scald for 10 s), the burn eschar was excised after 5 or 10 days postburn to determine the effect of a prolonged inflammatory focus. Results: Histology of both contact and scald burns revealed characteristics of a full-thickness injury marked by collagen coagulation and tissue necrosis. Excision at 2 days after a 20-s burn from either scald or contact showed significant delay in wound closure. Interval excision of the eschar, 5 or 10 days postburn, also showed significant delay in wound closure. Both interval-excision groups showed prolonged inflammation and increased myofibroblasts. Innovation and Conclusions: We have described the kinetics of wound closure in a murine model of a full-thickness burn excision. Both contact and scald full-thickness burn resulted in significantly delayed wound closure. In addition, prolonged interval-excision of the eschar appeared to increase and prolong inflammation.

Assessment of periostin levels in serum and gingival crevicular fluid of patients with periodontal disease

BACKGROUND AND OBJECTIVE

Periostin, a secreted adhesion molecule essential for periodontal tissue integrity, is highly expressed in the periodontal ligament and plays a critical role in tooth and bone development. The purpose of this study was to investigate periostin levels in the gingival crevicular fluid and serum of patients with periodontal disease and compare them with those of healthy individuals.

MATERIAL AND METHODS

Eighty individuals (41 males and 39 females; age range: 25-48 years) were enrolled in the study. Individuals were divided into three groups following clinical and radiographic examinations: the periodontal-healthy group (n = 20), gingivitis group (n = 30) and chronic periodontitis group (n = 30). Gingival crevicular fluid and serum samples were collected and periostin levels were determined using the enzyme-linked immunosorbent assay.

RESULTS

The total amount and concentration of periostin decreased in gingival crevicular fluid with the progression and severity of the disease from healthy controls to gingivitis and to chronic periodontitis groups and differed significantly (p < 0.05). However, there was no significant difference in serum periostin concentration within all groups (p > 0.05). Periostin in gingival crevicular fluid negatively correlated with the gingival index in the periodontal disease groups, whereas it is inversely correlated with the clinical attachment level only in the periodontitis group (p < 0.05). When all the clinical groups were examined together, the periostin concentration negatively correlated with clinical attachment level and gingival index; moreover, total periostin positively correlated with periostin concentration and clinical attachment level (p < 0.05).

CONCLUSIONS

The periostin levels in gingival crevicular fluid decreased proportionally with the progression and severity of periodontal disease, and negatively correlated with the clinical parameters. Within the limits of the study, the periostin level in gingival crevicular fluid can be considered a reliable marker in the evaluation of periodontal disease susceptibility and activity.

Palatal mucosa derived fibroblasts present an adaptive behavior regarding cytokine secretion when grafted onto the gingival margin

Background

Considering that grafted gingival tissue might have to be adapted to the receptor area and that fibroblasts have the ability to respond to bacterial stimuli through the release of various cytokines, this study investigated whether fibroblasts from the palatal mucosa behave differently when grafted onto the gingival margin regarding cytokine secretion.

Methods

Biopsies from the palatal mucosa were collected at the time of free gingival graft surgery, and after four months re-collection was performed upon surgery for root coverage. Fibroblasts were isolated by the explant technique, cultured and stimulated with Porphyromonas gingivalis (Pg) and Escherichia coli (Ec) LPS for 24 or 48 h for comparative evaluation of the secretion of cytokines and chemokines, such as IL-6, IL-8/CXCL8, MIP-1α/CCL3, TGF-β, VEGF and CXCL16. Unstimulated cells were used as the control group. Cells were tested for viability through MTT assay, and secretion of cytokines and chemokines was evaluated in the cell supernatants by Enzyme-Linked Immunosorbent Assay (ELISA).

Results

Fibroblasts from the palatal mucosa maintained the same secretion pattern of IL-6 when grafted onto the gingival margin. On the contrary, fibroblasts from the marginal gingival graft showed increased secretion of IL-8/CXCL8 even in the absence of stimulation. Interestingly, MIP-1α/CCL3 secretion by fibroblasts from the marginal gingival graft was significantly increased after 48 hours of stimulation with Pg LPS and after 24 h with Ec LPS. Only fibroblasts from the marginal gingival graft showed secretion of TGF-β. VEGF and CXCL16 secretion were not detected by both subsets of fibroblasts.

Conclusion

Fibroblasts from the palatal mucosa seem to be adapted to local conditions of the site microenvironment when grafted onto the gingival marginal area. This evidence supports the effective participation of fibroblasts in the homeostasis of the marginal periodontium through secretion modulation of important inflammatory mediators.

Myofibroblasts and transforming growth factor-beta1 in reactive gingival overgrowths

Objectives

The purpose of this study was to evaluate the oral health-related quality of life of patients treated with implant-supported mandibular overdentures and to compare the attachment systems used.

Material and Methods

The presence of myofibroblasts as well as transforming growth factor-beta1 was examined in twenty cases of fibrous epulis and 22 ossifying fibrous epulis, using immunohistochemistry.

Results

Myofibroblasts positive for alpha smooth muscle actin and vimentin but negative to desmin were found in 20% and 45% in fibrous epulis and ossifying fibrous epulis, respectively. Myofibroblasts were distributed in areas with and without inflammatory infiltration and their presence in inflammatory areas was not related with the degree of inflammatory infiltration. A percentage of 21 - 60% of fibroblasts and chronic inflammatory cells expressed transforming growth factor-beta1 in all cases.

Conclusions

These data suggest that transforming growth factor-beta1 and myofibroblasts contribute to the formation of collagenous connective tissue in fibrous epulis and ossifying fibrous epulis. Myofibroblasts are mainly presented in ossifying fibrous epulis than in fibrous epulis. It seems to be no relationship between the presence of myofibroblasts and the degree of inflammatory infiltration of the lesions.

Breast tumor and stromal cell responses to TGF-β and hypoxia in matrix deposition

The components that comprise the extracellular matrix (ECM) are integral to normal tissue homeostasis as well as the development and progression of breast tumors. The secretion, construction, and remodeling of the ECM are each regulated by a complex interplay between tumor cells, fibroblasts and macrophages. Transforming growth factor-β (TGF-β) is an essential molecule in regulating the cellular production of ECM molecules and the adhesive interactions of cells with the ECM. Additionally, hypoxic cell signals, initiated by oxygen deprivation, additional metabolic factors or receptor activation, are associated with ECM formation and the progression of breast cancer. Both TGF-β and hypoxic cell signals are implicated in the functional and morphological changes of cancer-associated-fibroblasts and tumor-associated-macrophages. Moreover, the enhanced recruitment of tumor and stromal cells in response to hypoxia-induced chemokines leads to increased ECM deposition and remodeling, increased blood vessel formation, and enhanced tumor migration. Thus, elucidation of the collaborative networks between tumor and stromal cells in response to the combined signals of TGF-β and hypoxia may yield insight into treatment parameters that target both tumor and stromal cells.

[Electrocardiographic findings during colonoscopy]

Impaired diabetic wound healing constitutes a major health problem. The impaired healing is caused by complex factors such as abnormal keratinocyte and fibroblast migration, proliferation, differentiation, and apoptosis, abnormal macrophage polarization, impaired recruitment of mesenchymal stem cells (MSCs) and endothelial progenitor cells (EPCs), and decreased vascularization. Diabetes-enhanced and prolonged expression of TNF-α also contributes to impaired healing. In this paper, we discuss the abnormal cell responses in diabetic wound healing and the contribution of TNF-α.