Analysis of gpr19 (g protein-coupled receptor 19), CSYT1 (sn cystatin) and NFE2l2 (NFE2-like bzip transcription factor 2) genes as biomarker candidates for age determination in human saliva samples by molecular methods

Biological aging is defined as a process in which the body loses its vitality, cannot continue its metabolism and inevitably results in death, which is regulated by genetic programs and occurs under the influence of environmental factors. The explanation of the mechanisms related to aging has been tried in many previous studies and many parameters that cause, delay or accelerate aging have been obtained. In this study, we aimed to make the process a little more understandable and contribute to routine use with 3 genes present in salivary fluid in order to estimate the ages of people. We collected saliva samples from groups of people with different ages and genders and performed a total RNA isolation study from saliva and performed cDNA synthesis. We calculated and statistically analyzed the data we obtained. According to the 2^ΔΔCt value of the CST1 gene obtained as a result of our study, we detected 1.73-fold upregulation in all female samples in the 14-19 age group and 2.2-fold downregulation in all females in the 24-29 age group. For the GPR19 gene, we detected 3.47-fold upregulation in all 14-19 age group female samples according to 2^ΔΔCt value. We detected 2.88-fold upregulation of this gene in all 30< age group males. For the NFE2L2 gene, we observed 2.7-fold upregulation in 14-19 age group females and 2.88-fold upregulation in 30< age group males. We also detected high downregulation in the youngest members of 4-9 age groups (both females and males) for all three genes. We recorded that the average 2^ΔΔCt value for all 3 genes was 31.8-fold downregulation in 4-year-old females and 4.6-fold downregulation in 6.5-year-old males. We believe that CST1, NFE2L2 and GPR19 genes can be used in age estimation, but we believe that more comprehensive studies should be conducted with larger sample groups.