Relationship between symptom severity and treatment resistance with TGF-β levels and target microrna expression in obsessive compulsive disorder patients

INTRODUCTION AND AIM: Our research investigated the regulation of miRNA-132-3p on TGF-β levels by determining TGF-β levels, miRNA-132-3p levels, which are thought to have an important role in TGF-β signaling, and the relationship between them, in healthy volunteers and patients diagnosed with obsessive-compulsive disorder. It aimed to understand and reveal its relationship with disease severity in people diagnosed with OCD. Our hypothesis is that miRNA-132-3p and TGF-β play important roles in the etiology and clinical severity of OCD, thus, TGF-β and miRNA-132-3p levels will differ in patients compared to healthy controls in correlation with disease severity. METHODS AND TOOLS: The study included 48 patients who applied to Balıkesir University Health Practice and Research Hospital Psychiatry Polyclinic, underwent SCID-5-CV and were diagnosed with Obsessive Compulsive Disorder according to DSM-V criteria, and 48 sociodemographically similar healthy volunteers. Blood samples were taken and miRNA-132-3p and TGF- β levels were measured in Genetics and Biochemistry laboratories using RT-PCR and Elisa methods. YBOCS and symptom list, HAMA, HAMD, Informed Consent Form, Sociodemographic and Clinical Information Form were applied to all participants. RESULTS: Our study is the first study to analyze TGF-β levels in adult OCD patients, as far as we can find in the literature. It was found that OCD patients were associated with lower TGF-β levels than healthy volunteers and there was a statistically significant difference between the two groups (P = 0.008). At the same time, a statistically significant negative relationship was observed between TGF-β levels and YBOCS compulsion, total scores, and disease duration, respectively (rs=-0.247, P=0.023; rs=-0.220, P=0.045; rs=-0.473, P=0.002). When the diagnostic performance of TGF-β was evaluated with the ROC curve, it was found to have 71,4% sensitivity and 59,5% specificity below 10,44 ng/mL. In our study, it has been observed that miRNA-132-3p levels are 1.92(1,92k) fold higher in patients with obsessive-compulsive disorder (OCD) compared to healthy controls, and a statistically significant difference has been detected between them(P=0.003). A statistically significant correlation was detected between Y-BOCS compulsion and total scores and miRNA-132-3p, respectively (rs=0.235, P=0.023; rs=0.208, P=0.045). When the diagnostic performance ROC curve of miRNA-132-3p was evaluated, it was determined that it had 61,7% sensitivity and 67,4% specificity above the 0.39 ratio. There was no statistically significant correlation between TGF-β values and miRNA-132-3p expression rates of all participants (rs = - 0.091, P = 0.414). CONCLUSION: Considering the results of our research, it is thought that changes in TGF-β and miRNA-132-3p levels, in line with our hypothesis, may be related to the etiology and symptomatology of OCD by affecting BDNF regulation, inflammatory responses such as Th1/Th2 and Th17/Treg balance, and various genes related to synaptic plasticity, in the light of previous studies. In addition, it is thought that our study may be important in shedding light on further studies with larger sample numbers to evaluate TGF-β and miRNA-132-3p as a potential diagnostic tool and therapeutic intervention target in OCD. Keywords: Obsessive compulsive disorder, MiRNA, TGF-ß