Metallothioneins and Their Influence on Bone Metabolism in Patients with Down Syndrome: Application to Dental Implants and Periodontitis

Abstract

In this gene validation study, we intended to verify the results of our first gene expression analysis. Metallothionein’s (MTs) are the lower molecular weight (6-7 kDa) proteins that are found to be present in almost all organism types ranging from prokaryotes to eukaryotes species. MT are the metal detecting proteins that can mitigate the effect caused by the excess metal ions. The study was descriptive and observational, and the only invasive procedures performed on patients were the collection of a small amount of blood and a dental examination.  We performed retrotranscription (RT-qPCR) of 11 RNA-to-cDNA samples using the SuperScript™ VILO™ kit (50; reference 1176605) from Thermo Fisher. We conducted the study using the real-time PCR technique on the q-PCR ViiA 7 platform from Thermo Fisher. We chose the format of the Taqman Array Plate 16 Plus (reference 4413261) from Thermo Fisher, which accommodates 12 genes plus four controls (GAPDH, 18S, ACTB, and HPRT1). We conducted the analysis of the plates using the Thermo Fisher Cloud Web Software. The results of altered MT expression that were first published came from the comparison between Down’s Syndrome patients with periodontal disease and implant failure (PD+RI+) after two years of progression versus Down’s syndrome patients without periodontal disease and with a positive progression of their implants (PD-RI-). The results obtained through gene validation analysis show that in PD+RI+ patients, the genes encoding the isoforms MT1F (FD 0.3; p = 0.039), MT1X (FD 338; p = 0.0078), MT1E (FD 307; p = 0.0358), and MT2A (FD 252; p = 0.0428) continue to show downregulation, whereas MT1B (FD 2.75; p = 0.580), MT1H (FD 281; p = 0.152), MT1L (FD 354; p = 0.0965), and MT1G (FD 336; p = 0.0749) no longer show statistically significant results. According to our results, metallotein metabolism is related to bone metabolism disorders that influence the course of periodontitis and the failure of dental implants in patients with Down syndrome.