Mitochondrial Creatine Kinase is Decreased in the Serum of Idiopathic Parkinson's Disease Patients.

Dongmei Wang,Guanghui Liu,Jianjun Lu,Jinghui Xu,Mengqiu Pan,Qing Wang,Qiong Chen,Qun Wang,Suyue Pan,Xiao Zhou,Xiaodi Fu,Xiaomei Zhang,Xiaoxian Huang,Yafang Hu,Yan Liu,Yanhui Li,Yunqi Xu,Zhaoyu Chen

doi:10.14336/ad.2018.0615

Abstract

Mitochondrial creatine kinase (MtCK) is vital in the process of mitochondrial energy metabolism, and mitochondrial dysfunction has been implicated in the pathogenesis of Parkinson’s disease (PD). Therefore, we speculated that MtCK activity could be altered in the serum of PD patients. However, no studies to date have investigated this specific topic, so we sought to investigate the serum MtCK activities among a cohort of PD patients. 50 patients with PD and 30 age-matched controls were recruited for this study. Serum ubiquitous MtCK (uMtCK) and sarcomeric MtCK (sMtCK) activities were assayed using an immunoinhibition method. Correlations between serum uMtCK/sMtCK activities and clinical features/parameters were explored in the PD group. Our study revealed a significant decrease in the uMtCK activity in the PD group when compared with the control group. No significant difference was found in the serum sMtCK activity between the PD and control groups. There was a significant correlation between serum uMtCK activities and the disease progression rate, duration, and age at onset in PD patients. While no significant relationship was found between the serum uMtCK activities and the Hoehn & Yahr stage or main non-motor symptoms scale. There was a significant decrease in the uMtCK activity in the serum of PD patients, which was associated with the rate of disease progression, duration, and age at onset of disease. Therefore, uMtCK activity in serum offers a useful clue for identification of PD biomarkers.

Highlights

Despite the efforts of past research, definitive evidence regarding the etiology of idiopathic Parkinson's disease (PD) is still lacking
We found no significant difference in different clinical dominant types of PD patients, the cases for the tremor dominant group were relatively small (Table 2)
We found a statistically significant, positive correlation between serum ubiquitous MtCK (uMtCK) activity and the rate of disease progression and age of onset

Summary

Introduction

Despite the efforts of past research, definitive evidence regarding the etiology of idiopathic Parkinson's disease (PD) is still lacking. Decreased Serum Activity of MtCK in Patients with PD disease outcome in patients. This is a challenging task because there are currently no known effective biomarkers that are obtained from the clinical population. Because the nervous system is an organ with a high level of energy consumption, the function of MtCK in neurons is important. One study found that uMtCK activity is approximately 63% lower in HD human brain samples as compared to non-diseased controls [12]. This decrease in MtCK activity could result in a great reduction in the efficiency of energy transfer, and lead to neuronal dysfunction. We have yet to find a study that explicitly focuses on the study of MtCK in clinical PD patients, and only several studies have investigated the serum CK levels of PD patients [14] and the CK-B activity of PD, idiopathic epilepsy, multiple sclerosis patients, etc.[15]

Methods

Results

Conclusion