RESUMO
Background: Exercise has been shown to promote a healthier and longer life and linked to a reduced risk of developing neurodegenerative diseases including retinal degenerations. However, the molecular pathways underpinning exercise-induced cellular protection are not well understood. In this work we aim to profile the molecular changes underlying exercise-induced retinal protection and investigate how exercise-induced inflammatory pathway modulation may slow the progression of retinal degenerations. Methods: Female C57Bl/6J mice at 6 weeks old were given free access to open voluntary running wheels for a period of 28 days and then subjected to 5 days of photo-oxidative damage (PD)-induced retinal degeneration. Following, retinal function (electroretinography; ERG), morphology (optical coherence tomography; OCT) and measures of cell death (TUNEL) and inflammation (IBA1) were analysed and compared to sedentary controls. To decipher global gene expression changes as a result of voluntary exercise, RNA sequencing and pathway and modular gene co-expression analyses were performed on retinal lysates of exercised and sedentary mice that were subjected to PD, as well as healthy dim-reared controls. Results: Following 5 days of PD, exercised mice had significantly preserved retinal function, integrity and reduced levels of retinal cell death and inflammation, compared to sedentary controls. In response to voluntary exercise, inflammatory and extracellular matrix integrity pathways were significantly modulated, with the gene expression profile of exercised mice more closely trending towards that of a healthy dim-reared retina. Conclusion: We suggest that voluntary exercise may mediate retinal protection by influencing key pathways involved in regulating retinal health and shifting the transcriptomic profile to a healthy phenotype.
RESUMO
BACKGROUND: Saliva plays a critical role in maintaining oral homeostasis; it modulates the ecosystem through lubrication of the alimentary bolus, protection against microorganisms, buffer and repair of the oral mucosa, and helps in dental re-mineralization. Various local and systemic factors such as medications, radiation therapy, systemic conditions, etc. can lead to reduction in salivary flow. A decrease in salivary function, known as Xerostomia, increases a patient's risk for caries and other oral infections. Palliative management of Xerostomia includes wetting agents such as ice chips, drugs and saliva substitutes. Systemic agents stimulate salivary flow but often have unfavorable side effects. Newer modalities like transcutaneous electrical nerve stimulation (TENS), which has fewer side effects, have been used to stimulate salivary flow. The aim of the present study was to assess and evaluate the effect of TENS on whole salivary flow rates in healthy adult subjects. STUDY DESIGN: A total of 80 healthy adult subjects were enrolled in the study. Unstimulated and stimulated saliva (using TENS) was collected for 5 minutes and the mean salivary flow rates were calculated. Data obtained was analyzed using the SPSS (Statistical package for social sciences) version 15. Students 't' test was employed for comparative analysis. RESULTS: Sixty-five of the 80 subjects demonstrated an increase in the salivary flow rate on application of TENS. Twelve subjects demonstrated a mild reduction in the salivary flow rates. Seven subjects experienced transient mild twitching of facial musculature as side effects. CONCLUSION: Significant increase in salivary flow rates was observed on application of TENS with minimal or no side effects. Key words:Stimulated saliva, whole salivary flow, TENS.
