Seok-Jae Kang

Parkinson’s disease (PD) is the most common neurodegenerative movement disorder, characterized by olfactory dysfunction in the early stages. α-Synuclein pathologies in the olfactory organs are shown to spread to the brain through the nose-brain axis. We first developed a nasal epithelial PD cellular model by treating RPMI-2650 cells with α-synuclein preformed fibrils (PFF). Upon uptake of PFF, RPMI-2650 cells showed mitochondrial proteome alteration and downregulation of parkin, which has previously been identified as a nasal biomarker of PD. Functional cluster analysis of differentially expressed genes in RPMI-2650 cells revealed various pathways affected by α-synuclein pathology, including the detection of chemical stimulus involved in sensory perception, olfactory receptor activity, and sensory perception of smell. Among genes that were most affected, we validated, by real-time quantitative PCR, the downregulation of MAP3K8, OR10A4, GRM2, OR51B6, and OR9A2, as well as upregulation of IFIT1B, EPN1, OR1D5, LCN, and OTOL1 in PFF-treated RPMI-2650 cells. Subsequent analyses of clinical samples showed a downregulation of OR10A4 and OR9A2 transcripts and an upregulation of IFIT1B in cells isolated from the nasal fluid of PD patients, as compared to those from the controls (cutoff value = 0.5689 for OR9A2, with 72.4% sensitivity and 75% specificity, and 1.4658 for IFIT1B, with 81.8% sensitivity and 77.8% specificity). Expression levels of these nasal PD markers were not altered in nasal fluid cells from SWEDD (scans without evidence of dopaminergic deficits) patients with PD-like motor symptoms. These nasal markers were significantly altered in patients of PD with hyposmia compared to the control hyposmic subjects. Our results validated the α-synuclein-treated nasal epithelial cell model to identify novel biomarkers for PD and suggest the utility of olfactory transcripts, along with olfactory dysfunction, in the diagnosis of PD.

Patients with Parkinson’s disease (PD) oftentimes develop olfactory dysfunction in their early stages, converting the nasal environment into a useful source of potential biomarkers. Here we determined the possible application of nasal fluid cells for PD biomarker identification. Thirty PD patients and 13 age-matched healthy controls were enrolled in this study. Messenger RNA levels of selected PD-related genes were monitored through real-time quantitative PCR. Target gene transcripts can be efficiently amplified from the cDNA library from human nasal fluid cell pellets. And subsequent analysis showed both a marked downregulation of parkin transcripts and an upregulation of AIMP2 in PD patients when compared to controls (cutoff value = 1.753 for with 84.2% sensitivity and 84.6% specificity; 0.359 for parkin with 76.7% sensitivity and 76.9 specificity). Moreover, alteration pattern of parkin and AIMP2 in PD was distinct from another neurodegenerative disease, multiple system atrophy. Analysis in both the early and late stages of PD cases reported that parkin levels inversely correlated with PD stages. Our results validate the practical value of easily accessible nasal fluid cells and the utility of both AIMP2 and parkin as potential biomarkers for PD diagnosis.

Background: Patients diagnosed with Parkinson’s disease (PD) on clinics who subsequently turn out to have normal dopamine transporter images have been referred to as scans without evidence of dopaminergic deficits (SWEDDs) patients. Cardiovascular autonomic dysfunction has frequently been reported in PD. In this study, we determined the similarities and differences in cardiac autonomic dysfunction between SWEDDs and PD patients. This study investigated whether 24-hour ambulatory blood pressure monitoring (24-hour ABPM) can help identify possible cases with SWEDDs. Methods: We enrolled 28 SWEDDs patients, 46 patients with PD, and 30 healthy controls. To evaluate cardiac autonomic function, 24-hour ABPM was performed on all subjects. Cardiac metaiodobenzylguanidine (MIBG) scintigraphy was performed on the SWEDDs and PD subjects. Results: The percentage nocturnal decline in blood pressure differed significantly among SWEDDs patients, PD patients, and controls (pConclusions: Pathologic nocturnal blood pressure regulation and nocturnal hypertension, known characteristics of PD, are also present in SWEDDs. Moreover, cardiac sympathetic denervation should not be attributed to cardiac autonomic dysfunction in SWEDDs patients. As with PD patients, the SWEDDs patients studied here tended to have cardiac autonomic dysfunction.

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare complication of Crohn's disease (CD), and it is uncertain whether it is associated with CD itself or with its treatment. We describe a case of CIDP-like neuropathy as an initial symptom of CD. The neurologic symptoms of the patient which responded partially to intravenous immunoglobulin (IVIG) recovered after resection of the appendiceal CD. A 17-year-old male had experienced three separate attacks of motor weakness and paresthesia of all four extremities over a period of 7 months. The electrophysiologic findings revealed a demyelinating sensory-motor polyneuropathy which was compatible with CIDP. However, repeated intravenous IVIG (2 g/kg) treatment gave only a partial response. Four days after the last discharge, he was diagnosed as appendiceal CD after surgical resection of a periappendiceal abscess. His neurologic symptoms and electrophysiologic findings recovered without any maintenance therapy. CIDP-like neuropathy can be an initial presentation of CD, and recovery of the CIDP symptoms may result from resection of the CD. Clinicians should be aware of the possibility of CD in patients with intractable CIDP symptoms.