INVESTIGATION OF THE EFFECTS OF CX3CL1 ON IMMUNOPATHOGENESIS AND COGNITIVE FUNCTIONS IN RELAPSING REMITTINGAND SECONDARY PROGRESSIVE MULTIPLE SCLEROSIS PATIENTS IN TERMS OF THE POSSIBILITY OF A BIOMARKER

Abstract

Objectives. CX3CL1 is a unique chemokine with direct relationship with its receptor to reduce expression of proinflammatory genes inactivated microglia.It is constitutively expressed by healty neurons and defined as neuroimmune regulatory protein.CX3CL1/CX3CR1signaling has been linked to human neurodegeneration. Under physiological conditions, disruption of this signaling leads to impairments inmotor learning, cognitive function, and synaptic plasticity. CX3CR1 also plays a role in the regulation of hippocampal-dependent memoryformation.Our aim in this study is to evaluate the role of CX3CL1 on immunopathogenesis and cognitive functions in Relapsing Remitting (RRMS) and Secondary Progressive Multiple Sclerosis (SPMS) patients in terms of biomarker possibility. Methods. Eight RRMS, 24 SPMS and 30 healty controls have been participated in this study. RRMS and SPMS were diagnosed according toMc Donald 2017 criteria. The degree of neurological deficits were assessed by EDSS.Serum levels of CX3CL1 were measured by ELISAmethod.The severity of cognitive impairment in patients were evaluate with MoCA test.Statistical analysis were performed using the IBMSPSS21. Results. When the RRMS, SPMS and control groups were compared,it was observed that the serum CX3CL1 levels in the SPMS groupwere decreased statistically significant.In addition,there was a positive correlation between MoCA score and serum CX3CL1 level in thepatients with RRMS and SPMS. Conclusion. Cytokines and chemokines play an important role in the immunopathogenesis of multiple sclerosis.Amongchemokines, serum levels of CX3CL1 was reported to be elevated in RRMS patients. However, it has not been observed in patients SPMS. CX3CL1 is an intrinsic neuroprotective chemokine and inhibitor against neurotoxicity. According to the results of our study, thedecrease in serum CX3CL1 levels serum CX3CL1 supports the development of neurodegeneration related neuroinflammation. In addition, thepositive correlation of MoCA test with CX3CL1 levels suggests that it has an important role in cognition. As a result, our study shows that CX3CL1 can be used as an early biomarker associated with disease progression and cognition, additionally it will be promising newtherapeutic target.