Myofibroblasts and increased angiogenesis contribute to periapical cystic injury containment and repair

Abstract

Background Myofibroblasts (MF) and angiogenesis are important factors in the development and expansion of cystic lesions, where these cells secrete growth factors and proteases, stimulating angiogenesis, matrix deposition and cell migration, affecting the growth of these periapicopathies. The present study aimed to evaluate the immunohistochemical expression of CD34 and α-SMA in radicular cysts (RC) and residual radicular cysts (RRC), with the purpose of contributing to a better understanding of the expansion and progression of these periapical lesions. Material and Methods The present study os a descriptive, quantitative and comparative analysis of positive CD34 and α-SMA immunohistochemical expressions in 30 RC and 30 RRC specimens. α-SMA expression was evaluated in the fibrous capsule of the lesions, at 100x magnification below the epithelial lining. A total of 10 higher immunostaining fields were selected and subsequently, positive cells were quantified at 400x magnification, averaged per field. Regarding the angiogenic index, immuno-labeled microvessel counts for the anti-CD34 antibody were performed in 10 fields at 200x magnification. Results Statistically significant differences regarding α-SMA immunostaining were observed ( p = 0.035), as well as a correlation between α-SMA versus CD34 ( p = 0.004) in RRC. However, the angiogenic index obtained by immunostaining for CD34 indicated no statistical difference between lesions. Intense inflammatory infiltrates were predominant in RC, while mild and moderate degrees were more commonly observed in RRC ( p <0.001). Intense inflammatory infiltrates were also more often noted in larger RRC ( p = 0.041). Inflammatory infiltrates showed no significant correlation with α-SMA and CD34 immunostaining. Conclusions The results indicate that the significant correlation found between the presence of MF and the angiogenic index are related to the repair process in RRC. Key words: Myofibroblasts, angiogenesis, inflammatory odontogenic cysts.

Release of Matrix Metalloproteinases by Macrophages in Radicular Cysts and Residual Radicular Cysts

“…The transforming growth factor-β is responsible for the deposition of collagen fibers in the cystic capsule, studies show that RRCs are more collagenous because of a greater amount of myofibroblasts and therefore have larger sizes with greater cystic expansion. 23 In the present study, M1 macrophages together with cytokine TNF-α were associated with RCs and smaller lesions, while M2 macrophages are associated with periapical granulomas and larger lesions, as noted in a study previously published by our research group in 2019. 24 CD68+ cells were more frequent in RCs, mainly in the subepithelial region, which are responsible for the release of inflammatory cytokines that stimulate the increase in epithelial thickness, as well as phagocytosis of antigens 22,24 and showed a moderate and significant correlation with TNF-α, suggesting a larger number of M1 cells in these lesions and Th1 polarization.…”

“…In contrast, M2 macrophages release growth factors such as transforming growth factor-β and immunosuppressive cytokines (IL-10 and IL-13), activating Th2 responses that participate in immunomodulatory states. The transforming growth factor-β is responsible for the deposition of collagen fibers in the cystic capsule, studies show that RRCs are more collagenous because of a greater amount of myofibroblasts and therefore have larger sizes with greater cystic expansion 23…”

Impact of CD34-dependent Micro Vessel Density on Periapical Odontogenic Cysts

“…In the current study, we estimated MVD levels in a fast and accurate way using a digitized algorithm based on CD34 IHC expression levels. Our previous studies on oral malignancies are concordant with similar experimental studies (29)(30)(31)(32)(33)(34)(35). All of them suggest and enhance this practice because it provides a systematic screening and mapping of immunostained slides.…”

Immunohistochemical expression of beta‐catenin, BMP4 and TGF‐beta in odontomas

“…In each sample, antibody expression was obtained as the percentage of positive cells using the following formula: percentage of stained cells = (number of immunopositive cells/total number of cells counted) × 100, according to a method adapted from Freitas et al. (2020).…”

“…The magnification was then increased to 400× according to the program specifications and 10 representative and consecutive fields of each case were photographed. In each sample, antibody expression was obtained as the percentage of positive cells using the following formula: percentage of stained cells = (number of immunopositive cells/total number of cells counted) × 100, according to a method adapted from Freitas et al (2020).…”