Role of angiogenesis in oral submucous fibrosis using vascular endothelial growth factor and CD34: An immunohistochemical study

Correlation between Vascularity and Advancing Histological Grades of Oral Submucous Fibrosis with a Plausible Role in Malignisation: Systematic review of a persisting matter of conflict

Objectives

This study aimed to quantify the vascularity in histological grades of oral submucous fibrosis (OSMF) and to determine if there is any connection between vasculogenesis and malignisation. Recent studies show no significant change in vascularity as the stage advances as opposed to the conventional concept.

Methods

A comprehensive database search until December 2022 was conducted for published articles on vascularity in OSMF following preferred reporting items for systematic reviews and meta-analyses guidelines.

Results

A total of 98 articles were screened of which 13 were included for systematic evaluation. The study included 607 cases, with a definite predilection for the male gender. Of the 13 studies, 11 evaluated mean vascular density. In more than half of the studies, the vascularity decreased as the stage advanced. Similar results were obtained for endothelial cells/μm2, mean vascular area percentage and mean vascular area.

Conclusion

The present review supports the prevailing concept that vascularity decreases with the advancement of the OSMF stage. This denies the systemic absorption of carcinogens into the circulation with resultant longer exposure of compromised epithelium and malignisation.

Knockdown of Notch Suppresses Epithelial-mesenchymal Transition and Induces Angiogenesis in Oral Submucous Fibrosis by Regulating TGF-β1

Oral submucous fibrosis (OSF) is a chronic disorder with a high malignant transformation rate. Epithelial-mesenchymal transition (EMT) and angiogenesis are key events in OSF. The Notch signaling plays an essential role in the pathogenesis of various fibrotic diseases, including OSF. Our study aimed to explore the effects of Notch on the EMT and angiogenesis processes during the development of OSF. The expression of Notch in OSF tissues versus normal buccal mucosa samples was compared. Arecoline was used to induce myofibroblast transdifferentiation of buccal mucosal fibroblasts (BMFs). Short hairpin RNA technique was used to knockdown Notch in BMFs. Pirfenidone and SRI-011381 were used to inhibit and activate the TGF-β1 signaling pathway in BMFs, respectively. The expression of Notch was markedly upregulated in OSF tissues and fibrotic BMFs. Knockdown of Notch significantly decreased the viability and promoted apoptosis in BMFs subjected to arecoline stimulation. Downregulation of Notch also significantly suppressed the EMT process, as shown by the reduction of N-cadherin and vimentin with concomitant upregulation of E-cadherin. In addition, knockdown of Notch upregulated VEGF and enhanced the angiogenic activity of fBMFs. Moreover, inhibition of TGF-β1 suppressed viability and EMT, promoted apoptosis, and induced angiogenesis of fBMFs, while activation of TGF-β1 significantly diminished the effects of Notch knockdown on fBMFs. Knockdown of Notch suppressed EMT and induced angiogenesis in OSF by regulating TGF-β1, suggesting that the Notch-TGF-β1 pathway may serve as a therapeutic intervention target for OSF.

Fibrotic Matrix Induces Mesenchymal Transformation of Epithelial Cells in Oral Submucous Fibrosis

Oral submucous fibrosis (OSF) is a potentially malignant disorder of the oral mucosa; however, whether and how the fibrotic matrix of OSF is involved in the malignant transformation of epithelial cells remains unknown. Herein, oral mucosa tissue from patients with OSF, OSF rat models, and their controls were used to observe the extracellular matrix changes and epithelial-mesenchymal transformation (EMT) in fibrotic lesions. Compared with controls, oral mucous tissues from patients with OSF showed an increased number of myofibroblasts, a decreased number of blood vessels, and increased type I and type III collagen levels. In addition, the oral mucous tissues from humans and OSF rats showed increased stiffness, accompanied by increased EMT activities of epithelial cells. The EMT activities of stiff construct-cultured epithelial cells were increased significantly by exogenous piezo-type mechanosensitive ion channel component 1 (Piezo1) activation, and decreased by yes-associated protein (YAP) inhibition. During ex vivo implantation, oral mucosal epithelial cells of the stiff group showed increased EMT activities and increased levels of Piezo1 and YAP compared with those in the sham and soft groups. These results indicate that increased stiffness of the fibrotic matrix in OSF led to increased proliferation and EMT of mucosal epithelial cells, in which the Piezo1-YAP signal transduction is important.

A biomaterial-based therapy using a sodium hyaluronate/bioglass composite hydrogel for the treatment of oral submucous fibrosis

Oral submucous fibrosis (OSF) is a chronic, inflammatory and potentially malignant oral disorder. Its pathophysiology is extremely complex, including excessive collagen deposition, massive inflammatory infiltration, and capillary atrophy. However, the existing clinical treatment methods do not fully take into account all the pathophysiological processes of OSF, so they are generally low effective and have many side effects. In the present study, we developed an injectable sodium hyaluronate/45S5 bioglass composite hydrogel (BG/HA), which significantly relieved mucosal pallor and restricted mouth opening in OSF rats without any obvious side effects. The core mechanism of BG/HA in the treatment of OSF is the release of biologically active silicate ions, which inhibit collagen deposition and inflammation, and promote angiogenesis and epithelial regeneration. Most interestingly, silicate ions can overall regulate the physiological environment of OSF by down-regulating α-smooth muscle actin (α-SMA) and CD68 and up-regulating CD31 expression, as well as regulating the expression of pro-fibrotic factors [transforming growth factor-β1 (TGF-β1), interleukin-10 (IL-10), tumor necrosis factor-α (TNF-α) and tissue inhibitors of metalloproteinase-1 (TIMP-1)] and anti-fibrotic factors [interleukin-1β (IL-1β)] in macrophage. In conclusion, our study shows that BG/HA has great potential in the clinical treatment of OSF, which provides an important theoretical basis for the subsequent development of new anti-fibrotic clinical preparations. STATEMENT OF SIGNIFICANCE: : Oral submucous fibrosis (OSF) is a chronic, inflammatory and potentially malignant mucosal disease with significant impact on the quality of patients' life. However, the existing clinical treatments have limited efficacy and many side effects. There is an urgent need for development of specific drugs for OSF treatment. In the present study, bioglass (BG) composited with sodium hyaluronate solution (HA) was used to treat OSF in an arecoline-induced rat model. BG/HA can significantly inhibit collagen deposition, regulate inflammatory response, promote angiogenesis and repair damaged mucosal epithelial cells, and thereby mitigate the development of fibrosis in vivo.

VEGF gene transfection restores the angiogenesis of oral submucous fibrosis in mice

Background

To explore the effectiveness of adenovirus-enhanced green fluorescent protein-vascular endothelial growth factor165 (AD-EGFP-VEGF165) transfection on fibroblasts from mice, and we assessed whether VEGF165 restores the angiogenesis of oral submucous fibrosis (OSF) in mice.

Methods

AD-EGFP-VEGF165 and AD-EGFP were transfected into fibroblasts from mouse buccal tissues in vitro. The expression of VEGF before and after transfection was detected by RT-qPCR and ELISA in each group of fibroblasts. Fifteen OSF mice (pre-experimental construction) were randomly divided into 3 groups, and equal amounts of AD-EGFP-VEGF165 virus, AD-EGFP virus, and saline were injected into the buccal submucosal tissue of OSF mice. The expression of VEGF and local tissue angiogenesis were observed and measured in each group of animals.

Results

The Ad-EGFP-VEGF165-transfected fibroblasts increased human and mouse VEGF expression compared to the Ad-EGFP group and control group (P<0.05). The buccal submucosal tissue of mice was injected with Ad-EGFP-VEGF165 after the 6th day, and the expression of VEGF was effectively expressed in AD-EGFP-VEGF165 group (P<0.05), while no positive expression observed in other groups. and the number of microvessels in the AD-EGFP-VEGF165 group increased significantly compared to the other groups (P<0.05).

Conclusions

Ad-EGFP-VEGF165 can be successfully transfected into fibroblasts from mice, and restored the angiogenesis of OSF in mice.

Agnuside Alleviates Synovitis and Fibrosis in Knee Osteoarthritis through the Inhibition of HIF-1α and NLRP3 Inflammasome

Increasing evidence has shown that NLRP3 inflammasome activation participates in chronic aseptic inflammation and is related to tissue fibrosis. Our last study also revealed the vital role of NLRP3 inflammasome, highly associated with tissue hypoxia, in the onset and development of knee osteoarthritis (KOA). In this study, we tried to find a possible benign intervention for that pathological process. Agnuside (AGN), a nontoxic, natural small molecule isolated from the extract of Vitex negundo L. (Verbenaceae), has been demonstrated to have antioxidation, anti-inflammatory, analgesia, and many other properties as an iridoid glycoside, although its specific target is still unclear. Therefore, we established MIA-induced KOA model rats and investigated the effects of AGN oral gavage on oxygen-containing state, NLRP3 inflammasome, synovitis, and fibrosis in KOA. Pimonidazole staining and HIF-1α immunohistochemical assay both showed that AGN at the oral dose of 6.25 mg/kg can effectively relieve local hypoxia in synovial tissue. Besides, we observed a decrease of HIF-1α, caspase-1, ASC, and NLRP3 after AGN intervention, both in the mRNA and protein levels. In addition, rats treated with the AGN showed less inflammatory reaction and fibrosis, not only in the expression of NLRP3, inflammasome downstream factors IL-1β and IL-18, and fibrosis markers TGF-β, TIMP1, and VEGF but also in the observation of HE staining, anatomical characteristics, Sirius Red staining, and type I collagen immunohistochemistry. Subsequently, we established LPS-induced models of fibroblast-like synoviocytes (FLSs) mimicking the inflammatory environment of KOA and activating NLRP3 inflammasome. FLSs treated with AGN (3 μM) resulted in a downregulation of HIF-1α and the components required for NLRP3 inflammasome activation. Meanwhile, the content of proinflammatory factors IL-1β and IL-18 in FLS supernatant was also reduced by AGN. In addition, both mRNA and protein levels of the fibrotic markers were significantly decreased after AGN management. To conclude, this study demonstrates that AGN alleviates synovitis and fibrosis in experimental KOA through the inhibition of HIF-1α accumulation and NLRP3 inflammasome activation. Additionally, not only does it reveal some novel targets for anti-inflammatory and antioxidant effects of AGN but also announces its potential value in treating KOA in humans.

The Role of Increased Connective Tissue Growth Factor in the Pathogenesis of Oral Submucous Fibrosis and its Malignant Transformation-An Immunohistochemical Study

Connective tissue growth factor (CTGF), a matricellular protein of the CCN family of extracellular matrix-associated heparin-binding proteins, is highly expressed in various organ fibrosis and several malignant tumors. Although a few studies have been conducted using CTGF in oral submucous fibrosis (OSF) and oral squamous cell carcinoma, no study has demonstrated its relation with various stages of OSF and its malignant transformation. The present study investigated the possible role of CTGF in the pathogenesis of OSF and its malignant transformation by using immunohistochemistry. Ten formalin-fixed paraffin-embedded tissue blocks, each of Stage 1 OSF, Stage 2 OSF, Stage 3 OSF, Stage 4 OSF, well- differentiated squamous cell carcinoma (WDSCC) with OSF and WDSCC without OSF were stained for CTGF by immunohistochemistry. Ten cases of healthy buccal mucosa (NOM) were included as controls. The present study demonstrated a statistically significant expression of CTGF in the epithelium and connective tissue of OSF and WDSCC with and without OSF cases against its complete absence in NOM. We observed an upregulation of CTGF expression from NOM to various stages of OSF to WDSCC with or without OSF. A gradual upregulation of the CTGF expression in various stages of OSF to WDSCC (with and without OSF) against its complete absence in NOM suggests that CTGF plays an important role in the pathogenesis of OSF and its malignant transformation.

Which Factors, Smoking, Drinking Alcohol, Betel Quid Chewing, or Underlying Diseases, Are More Likely to Influence the Severity of COVID-19?

The global outbreak of the coronavirus disease 2019 (COVID-19) pandemic occurred in late 2019 and early 2020. The factors that influence disease severity should be of clinical concern. Existing findings on the effects of smoking on COVID-19 are also controversial and need to be confirmed by further research. In addition, the effects of alcohol consumption and betel quid (BQ) chewing on COVID-19 are unclear. The aim of this study was to examine the demographic characteristics of COVID-19 patients and the effects of smoking, drinking, BQ chewing, and underlying diseases on the severity of COVID-19. A retrospective study was conducted on 91 patients with confirmed cases of COVID-19 hospitalized in Yueyang, Hunan Province, China from 21 January to 8 March, 2020. Patient demographic data, and information on smoking, drinking and BQ chewing, and underlying diseases were extracted from the patient electronic medical records (EMR) and telephone interviews. The chi-square test was used to conduct a univariate analysis of the factors influencing the severity of COVID-19, and ordinal logistic regression analysis was used to identify the factors related to the severity of COVID-19. The results showed that the rates of smoking, drinking and BQ chewing were 15.4, 26.4, and 7.1%, respectively, there was no significant relationship between these lifestyle factors and the severity of COVID-19 (P > 0.05). However, underlying diseases such as diabetes [odds ratio (OR) = 7.740, 95% confidence interval (CI):1.000-60.740, P = 0.050], source of infection (OR = 0.180, 95% CI: 0.030-0.980, P = 0.049), and employment status (retired/unemployed vs. employed: OR = 29.430, 95% CI, 1.050 - 822.330, P = 0.047) were significant independent predictors of severe COVID-19 infection. These individuals should be informed of methods to increase personal protection, and doctors should prevent these individuals from developing serious diseases. It is important to pay attention to the source of infection and timely medical treatment. This study showed that the clinical classification of COVID-19 was associated with patients with diabetes, source of infection, and retired/unemployed. Therefore in the clinical practice of COVID-19 should be more concern these factors. Although no statistical significance was found in smoking, drinking alcohol, BQ chewing, and severity of COVID-19 patients, more studies have confirmed that are harmful and risk factors for underlying diseases in the population. Health authorities should formulate policies to publicize the harmful effects of smoking, drinking, and betel nut chewing and promote a healthy lifestyle.

Effects of Botulinum Toxin Type A on Microvessels in Hypertrophic Scar Models on Rabbit Ears

Background

Although Botulinum Toxin Type A (BTXA) has been applied to scar prevention and treatment, the mechanisms still require further exploration.

Objective

To investigate the effects of BTXA on microvessels in the hypertrophic scar models on rabbit ears.

Methods

Eight big-eared New Zealand rabbits (males or females) were selected to establish scar models. One ear of each rabbit (4 models in each ear) was selected randomly to be injected with BTXA immediately after modeling and included in the treated group, while the opposite ear was untreated and included in the control group. The growth of scars in each group was observed and recorded, and 4 rabbits were sacrificed on days 30 and 45 after modeling. Then, scar height was measured by hematoxylin-eosin (HE) staining, vascular endothelial growth factor (VEGF) expression was detected by immunohistochemical (IHC) testing, and microvessel density (MVD) was calculated based on CD34 (human hematopoietic progenitor cell antigen).

Results

The wounds in each group were well healed and free from infection or necrosis. On days 30 and 45, the scar height, MVD value, and VEGF expression in the treated group were lower than those in the control group (P < 0.05). For the treated group, the above indicators on day 45 were lower than on day 30 (P > 0.05). Besides, there was a positive correlation between the MVD value and the VEGF expression in the treated group (P < 0.05).

Conclusion

The injection of BTXA immediately after modeling inhibits VEGF expression and reduces angiogenesis, thereby inhibiting hypertrophic scar formation.