miRNAs involved in neuropathic pain can be reliably measured in saliva

Abstract

Background: miRNAs have been shown to be dysregulated in Neuropathic pain conditions such as diabetic painful neuropathy (DPN). While invasive techniques such as blood samples are routinely used to collect and analyse miRNAs, the use of non-invasive techniques such as salivary samples for analysing miRNAs involved in neuropathic pain has been minimal. Therefore, the objective of this study was to determine if miRNAs involved in neuropathic pain can be measured reliably in salivary samples comprising of healthy European and Pacific population. Methods: Participants were recruited via advertisements on notice boards, social media, word of mouth, and pamphlets. Saliva samples were collected from healthy European and Pacifica Participants. Samples were stored in -80ºC until analysis. Total RNA was extracted using miRNEasy kit (Qiagen) following manufacturer’s protocol and the concentration was measured using Nanodrop (Thermofisher). Results: A total of 37 healthy participants (19 European and 18 Pacifica; age range: 22-57 years) were included in the study. Results showed that four different miRNAs (miR-16, miR-124, miR-132 and miR-134) that have been demonstrated to be associated with DPN were expressed and reliably measured in all the salivary samples. Conclusion: all the miRNAs identified in our study have been shown to be involved in neuropathic pain and inflammation. Hence, further research is required in this area to investigate the feasibility of extracting and analysing these miRNAs in people with neuropathic pain.