Isoproterenol modulates matrix metalloproteinase-2 (MMP-2) and its tissue inhibitor-2 (TIMP-2) in rat parotid gland

Extracellular matrix turnover in salivary gland disorders and regenerative therapies: Obstacles and opportunities

Salivary gland (SG) extracellular matrix (ECM) has a major influence on tissue development, homeostasis, and tissue regeneration after injury. During aging, disease, and physical insult, normal remodeling of the SG microenvironment (i.e. ECM) becomes dysregulated, leading to alterations in matrix composition which disrupt tissue architecture/structure, alter cell activity, and negatively impact gland function. Matrix metalloproteinases (MMPs) are a large and diverse family of metalloendopeptidases which play a major role in matrix degradation and are intimately involved in regulating development and cell function; dysregulation of these enzymes leads to the production of a fibrotic matrix. In the SG this altered fibrotic ECM (or cell microenvironment) negatively impacts normal cell function and the effectiveness of gene and stem cell therapies which serve as a foundation for many SG regenerative therapies. For this reason, prospective regenerative strategies should prioritize the maintenance and/or restoration of a healthy SG ECM. Mesenchymal stem cells (MSCs) have great potential for mitigating damage to the SG microenvironment by ameliorating inflammation, reducing fibrosis, and repairing the damaged milieu of extracellular regulatory cues, including the matrix. This review addresses our current understanding of the impact of aging and disease on the SG microenvironment and suggests critical deficiencies and opportunities in ECM-targeted therapeutic interventions.

Salivary glands of fetuses are adversely affected by artificial food colorings in rats

OBJECTIVE

Artificial food colorings, as types of food additives, are widely used at present in daily life. We aimed to investigate the effects of exposure to artificial food colorings during the intrauterine period on the salivary glands in adulthood.

METHODS

A total of 30 Wistar albino female pregnant rats were included in this study. The treatment group was given a mixture of nine artificial food colorings at no observed adverse-effect-level doses. Neither mothers nor offspring were fed with food colorings after delivery. When the offspring became adults, they were sacrificed, and the possible histopathological and immunohistochemical effects of artificial food colorings on the salivary glands were investigated. In these glands, anti-matrix metallopeptidase 2 (anti-MMP2), anti-MMP9, anti-tissue inhibitor of metalloproteinases (TIMP) metallopeptidase inhibitor 1 (anti-TIMP1), anti-TIMP2, and anti-TIMP3 were examined.

RESULTS

The expressions of anti-MMP2, anti-TIMP1, anti-TIMP2, and anti-TIMP3 parameters were found to be higher in treatment groups (p<0.05).

CONCLUSION

It was suggested that intrauterine exposure of synthetic food colorings may lead to deterioration of the tissue structure of the salivary glands in adulthood, thereby increasing susceptibility to chronic illnesses including malignancy and chronic inflammation. Therefore, pregnant women should give importance to their nutrition in terms of foods containing synthetic colorings.