Epidermal growth factor attenuates lingual papillae lesions in a rat model of sialoadenectomy

Cell type-specific transforming growth factor-β (TGF-β) signaling in the regulation of salivary gland fibrosis and regeneration

Salivary gland damage and hypofunction result from various disorders, including autoimmune Sjögren's disease (SjD) and IgG4-related disease (IgG4-RD), as well as a side effect of radiotherapy for treating head and neck cancers. There are no therapeutic strategies to prevent the loss of salivary gland function in these disorders nor facilitate functional salivary gland regeneration. However, ongoing aquaporin-1 gene therapy trials to restore saliva flow show promise. To identify and develop novel therapeutic targets, we must better understand the cell-specific signaling processes involved in salivary gland regeneration. Transforming growth factor-β (TGF-β) signaling is essential to tissue fibrosis, a major endpoint in salivary gland degeneration, which develops in the salivary glands of patients with SjD, IgG4-RD, and radiation-induced damage. Though the deposition and remodeling of extracellular matrix proteins are essential to repair salivary gland damage, pathological fibrosis results in tissue hardening and chronic salivary gland dysfunction orchestrated by multiple cell types, including fibroblasts, myofibroblasts, endothelial cells, stromal cells, and lymphocytes, macrophages, and other immune cell populations. This review is focused on the role of TGF-β signaling in the development of salivary gland fibrosis and the potential for targeting TGF-β as a novel therapeutic approach to regenerate functional salivary glands. The studies presented highlight the divergent roles of TGF-β signaling in salivary gland development and dysfunction and illuminate specific cell populations in damaged or diseased salivary glands that mediate the effects of TGF-β. Overall, these studies strongly support the premise that blocking TGF-β signaling holds promise for the regeneration of functional salivary glands.

Study of the Possible Alleviated Role of Atorvastatin on Irinotecan-Induced Lingual Mucosal Damage: Histological and Molecular Study

BACKGROUND

Oral mucositis is the most debilitating and troublesome adverse effect of irinotecan (CPT-11) treatment. It adversely affects the patient quality of life. The aim of this work was to study the histological, immunohistochemical, and molecular changes in the oral mucosa by CPT-11 and the possible alleviated role of atorvastatin.

METHODS

Rats were randomly divided into control, CPT-11-treated group, and CPT-11+ atorvastatin-treated group. At the end of the experiment, the anterior two-thirds of the tongue was dissected out and divided into two parts: one part for light microscopic examination and the second for molecular study.

RESULTS

CPT-11-treated group revealed loss of normal mucosal organization, areas of ulceration and inflammation, and loss of architecture of lingual papillae. A significant decrease in immunohistochemical and molecular gene expression of Ki-67 and antiapoptotic Bcl-2 levels was observed. A significant increase in NF-κB immunohistochemical and mRNA gene expression level and a nonsignificant increase in Nrf2 gene expression were detected. Coadministration of atorvastatin showed remarkable improvement in the histopathological picture with a significant increase in Ki-67 and Bcl-2, a significant decrease in NF-κB protein and gene expression, and a significant increase in Nrf2 gene expression.

CONCLUSION

Atorvastatin substantially attenuates CPT-11-induced oral mucositis through the initiation of the antiapoptotic gene, modulation of the inflammatory, and antioxidant gene expression.

Mesna ameliorates acute lung injury induced by intestinal ischemia-reperfusion in rats

The lung is severely affected by intestinal ischemia-reperfusion (I-R) injury. Mesna, a thiol compound, possess anti-inflammatory and antioxidant properties. We aimed in the present work to explore the potential beneficial effects of Mesna on the acute lung damage mediated by intestinal I-R in a rat model. Forty male adult albino rats were randomly separated into; control, intestinal I-R, Mesna I and Mesna II groups. Mesna was administered by intraperitoneal injection at a dose of 100 mg/kg, 60 min before ischemia (Mesna I) and after reperfusion (Mesna II). Arterial blood gases and total proteins in bronchoalveolar lavage (BAL) were measured. Lung tissue homogenates were utilized for biochemical assays of proinflammatory cytokines and oxidative stress markers. Lung specimens were managed for examination by light and electron microscopy. Our results revealed that Mesna attenuated the histopathological changes and apoptosis of the lung following intestinal I-R. Mesna also recovered systemic oxygenation. Mesna suppressed neutrophil infiltration (as endorsed by the reduction in MPO level), reduced ICAM-1 mRNA expression, inhibited NF-κB pathway and reduced the proinflammatory cytokines (TNF-α, IL-1β and IL-6) in the lung tissues. Mesna maintained the antioxidant profile as evidenced by the elevation of the tissue GPx and SOD and down-regulation of HSP70 immune-expressions. Accordingly, Mesna treatment can be a promising way to counteract remote injury of the lung resulted from intestinal I-R.