Dynamic role of myofibroblasts in oral lesions

Evaluation of stromal myofibroblasts in oral submucous fibrosis and its malignant transformation: An immunohistochemical study

BACKGROUND

Oral submucous fibrosis (OSF) is a precancerous lesion, with oral squamous cell carcinoma (OSCC) being the most prevalent malignancy affecting the oral mucosa. The malignant transformation of OSF into OSCC is estimated to occur in 7-13% of cases. Myofibroblasts (MFs) play pivotal roles in both physiological and pathological processes, such as wound healing and tumorigenesis, respectively. This study aimed to explore the involvement of MFs in the progression of OSF and its malignant transformation.

MATERIALS AND METHODS

In total, 94 formalin-fixed paraffin-embedded tissue blocks were collected, including normal oral mucosa (NOM; n = 10), early-moderate OSF (EMOSF; n = 29), advanced OSF (AOSF; n = 29), paracancerous OSF (POSF; n = 21), and OSCC (n = 5) samples. Alpha-smooth muscle actin was used for the immunohistochemical identification of MFs.

RESULTS

NOM exhibited infrequent expression of MFs. A higher staining index of MFs was found in AOSF, followed by EMOSF and NOM. Additionally, a significant increase in the staining index of MFs was found from EMOSF to POSF and OSCC. The staining index of MFs in NOM, EMOSF, AOSF, POSF, and OSCC was 0.14 ± 0.2, 1.69 ± 1.4, 2.47 ± 1.2, 3.57 ± 2.6, and 8.86 ± 1.4, respectively. All results were statistically significant (P < 0.05).

CONCLUSIONS

The expression of MFs exhibited a gradual increase as the disease progressed from mild to malignant transformation, indicating the contributory role of MFs in the fibrogenesis and potential tumorigenesis associated with OSF.

Correlation of density of microvessels and myofibroblasts with the aggressiveness of central giant cell granulomas of jaws: A preliminary study

Objectives

Central giant cell granuloma (CGCG) is a fairly common lesion involving the jaw bones. CGCG can show relatively innocuous biological behaviour or it may show clinicoradiological features suggestive of aggressive biological behaviour. To date, there are no histological parameters which can be used to predict the behaviour of these lesions. This study was conducted to assess the utility of parameters of angiogenesis, i.e., total vascular area (TVA), mean vascular area (MVA) and microvessel density (MVD), and density of myofibroblasts in aggressive and non-aggressive CGCGs.

Materials and Methods

The study was undertaken as a retrospective study. A total of 20 previously diagnosed cases (10 non-aggressive and 10 aggressive) of CGCGs were included in the study. The sections were subjected to immunohistochemistry using the markers CD34 and α-SMA. For the assessment of vascular parameters, image J software was used. The density of myofibroblasts was determined in each case ranging from score-1 to 4, using the criteria given by Sridhara et al. The correlation between mean values of vascular parameters and density of myofibroblasts with aggressiveness of CGCG was assessed using Mann-Whitney U test.

Results

The result of Mann-Whitney U test suggested that the differences between the values of TVA (P < 0.001), MVA (P < 0.003) and density of myofibroblasts, i.e., SMA mean (P < 0.001) and SMA score (P < 0.001), in two groups are statistically significant. The formula for the assessment of aggressiveness was obtained using discriminant analysis.

Conclusions

Angiogenesis and density of myofibroblasts significantly differ in aggressive and non-aggressive cases of CGCGs. The aggressiveness of CGCG case can be predicted using the obtained formula by entering the values of vascular parameters and myofibroblasts.

Expression of anti-fungal peptide, β-defensin 118 in oral fibroblasts induced by C. albicans β-glucan-containing particles

Objective:

Methodology:

Results:

Conclusion:

Photobiomodulation Enhances the Healing of Postextraction Alveolar Sockets: A Randomized Clinical Trial With Histomorphometric Analysis and Immunohistochemistry

PURPOSE

Wound healing of postextraction sockets is a complex process that permits to reach the bone reformation in about 3 months, and that could be characterized by the presence of some complications, mainly dependent on the duration of the surgery. The aim of this study is to evaluate the impact of photobiomodulation (PBMT) on the healing processes of mucosa overlying postextraction alveolus and on related complications.

METHODS

Twenty systemically healthy patients who needed to extract both lower third molars were selected in a private clinic and included in this prospective split-mouth randomized clinical trial. Inclusion criteria were no smokers subjects with the necessity to extract both lower third molars with surgeries overlapping for duration and difficulty. A computer-based randomization procedure was permitted to choose the side, subject to PBMT, by means of a neodymium-doped YAG (Nd: YAG) laser (test) and controls. Both surgeries were performed by the same operator with a gap of 40 days. Twenty-two days after each surgery, a biopsy in correspondence to the alveolar mucosa of the socket was obtained from both sites and observed with an optical microscope and analyzed with histomorphometric analysis and immunohistochemistry.

RESULTS

Each of the 20 participants included in this study (11 women and 9 men, nonsmokers, mean age 16 years in the range of 15 to 17 years) were subjected to the extraction of both lower third molars, and a side was treated as control, the other, as the test. The histomorphometric analysis and immunohistochemistry showed that the tested sites, contrary to controls, were characterized by a lower presence of inflammatory cells, a more mature epithelium and myofibroblasts incorporated in a network of fibers parallel to the basal membrane, with little positivity to alpha-SMA antibodies and anti-myosin but positivity to anti-desmin.

CONCLUSIONS

In conclusion, PBMT accelerates the healing process of postextraction alveolus after third molar extraction.

Comparison of expression of myofibroblasts in normal oral mucosa, oral epithelial dysplasia, and oral squamous cell carcinoma using α-SMA and vimentin: An immunohistochemical study

Background:

Myofibroblasts are thought to play critical roles in inflammation, growth, repair, premalignancy, and malignancy. This study was done to evaluate, compare and co- relate the progressive increase in the immunohistochemical expression of myofibroblasts in normal oral mucosa, epithelial dysplasia, and oral squamous cell carcinoma (OSCC). To compare and co-relate the expression of myofibroblasts in normal oral mucosa, epithelial dysplasia, and oral squamous cell carcinoma. To co-relate the progressive increase in myofibroblasts expression in normal oral mucosa, epithelial dysplasia, and oral squamous cell carcinoma.

Materials and Method:

Forty-nine paraffin-embedded tissue blocks with 7 cases of normal oral mucosa, 21 cases of epithelial dysplasia, and 21 diagnosed cases of OSCCs were studied. The samples were subjected to heat-induced antigen retrieval methods followed by staining using primary mouse monoclonal antibodies against α-smooth muscle actin (SMA) and vimentin. Staining index of all the sections was calculated. Statistical analysis was performed using the Kruskal–Wallis test, Mann–Whitney U test, and Chi-square test. Values of P less than or equal to 0.05 (P ≤ 0.05) were considered statistically significant.

Results:

Statistically significant staining index was obtained by α-SMA and vimentin between normal oral mucosa, epithelial dysplasia, and OSCC.

Conclusion:

Myofibroblast may play a role only during initial tumorigenesis that is the conversion of severe dysplasia into OSCC.

Immunohistochemical Expression of Myofibroblasts Using Alpha-smooth Muscle Actin (SMA) to Assess the Aggressive Potential of Various Clinical Subtypes of Ameloblastoma

Objective:

Ameloblastoma is a rare odontogenic neoplasm with high recurrence rates if improperly treated. If left untreated (or is treated inadequately), it can cause substantial morbidity, disfigurement, and even death. Hence, there is a need to explore the stromal cells too, which might play an important role in assessing its aggressive behavior and may help to predict the recurrence of different clinical variants of ameloblastoma. Myofibroblasts (MFs) are such cells which have been studied in various lesions.

Materials and Methods:

This retrospective study involved archival tissues of ameloblastoma. Among a total of 40 cases, 12 cases of SMA (solid multicystic ameloblastoma), 10 cases of unicystic ameloblastoma (UA), 8 cases of desmoplastic ameloblastoma, and 10 cases of oral squamous cell carcinoma were selected as control. Immunohistochemical staining with anti-alpha-smooth muscle actin antibody was done. Interpretation of ten examined fields was counted by three observers.

Results:

Significant difference in the number of MFs in SMA and UA and desmoplastic ameloblastoma and UA (P < 0.05) was found. However, there was no statistically significant difference in MFs of SMA and desmoplastic ameloblastomas (P > 0.05). In addition, there was no statistically significant difference in the staining intensity between the three variants (P > 0.05).

Conclusion:

A significant correlation was obtained between the number of MF in all the three clinical variants, i.e., SMA, UA, and desmoplastic ameloblastoma (P = 0.02), which is the unique feature of the study.

Oral lichen-planus-associated fibroblasts acquire myofibroblast characteristics and secrete pro-inflammatory cytokines in response to Porphyromonas gingivalis lipopolysaccharide stimulation

Background

Oral lichen planus (OLP) is a chronic inflammatory oral mucosal disease in which comprehensive inflammation-related cytokines are involved. These cytokines are commonly produced by immune cells and specific nonimmune cells including keratinocytes, endothelial cells and fibroblasts. This raises the question of whether fibroblasts in OLP lesions contribute to the inflammatory process upon inflammatory simulation.

Methods

Primary cultured Oral lichen-planus-associated fibroblasts (OLP AFs, n = 5) and normal buccal mucosal fibroblasts (NFs, n = 5) were examined by immunohistochemistry, Western blotting and reverse transcription-polymerase chain reactions (RT-PCR). Various inflammatory mediators were evaluated with a multiplex assay. Differences among groups were assessed using a Student’s test or repeated measures one-way ANOVA, as appropriate.

Results

OLP AFs express significantly higher levels of α-smooth muscle actin (α-SMA) than NFs, indicating the presence of myofibroblasts. Myofibroblasts secrete Interleukin (IL)-6, IL-8, and tumor necrosis factor-α (TNF-α) in response to Porphyromonas gingivalis lipopolysaccharide (pg. LPS).

Conclusion

OLP AFs demonstrated α-SMA expression and secreted pro-inflammatory cytokines in response to pg. LPS stimulation.

Electronic supplementary material

The online version of this article (10.1186/s12903-018-0656-6) contains supplementary material, which is available to authorized users.

The Effects of Rifampin, Povidone-Iodine and Hydrogen Peroxide on the Formation of Epidural Fibrosis in the Experimental Epidural Fibrosis Model

The aim of the study was to determine the effect of direct application of rifampin, povidone-iodine, and hydrogen peroxide on the formation of epidural fibrosis in rats. Forty-eight adult male Wistar albino rats were equally and randomly divided into four groups (laminectomy, topical rifampin, topical povidone-iodine, and topical hydrogen peroxide). Laminectomy was performed at the T12 level in all rats. Four weeks later, the extent of epidural fibrosis was assessed both macroscopically and histopathologically. ANOVA test was used for the evaluation of dural thickness. Kruskal-Wallis test was used for the pathology and macroscopic evaluation. Chi-square test was used for evaluation of the arachnoid involvement. p value <0.05 was accepted as statistically significant. Our data revealed that topical application of both povidone-iodine and hydrogen peroxide were effective in reducing epidural fibrosis formation. The results of our study provide the experimental evidence of the preventive effects of topical application of povidone-iodine and hydrogen peroxide over epidural fibrosis.