Tae-Beom Ahn

α-Synuclein induces apoptosis by altered expression in human peripheral lymphocyte in Parkinson’s disease

Though the etiology of Parkinson’s disease (PD) remains unclear, α‐synuclein (α‐SN) is regarded as a major causative agent of PD. Several lines of evidence indicate that immunological abnormalities are associated with PD for unknown reasons. The present study was performed to assess whether peripheral blood mononuclear cells (PBMCs) show altered α‐SN expression in PD patients and to identify its functions, which may be related to peripheral immune abnormalities in PD. α‐SN was found to be expressed more in 151 idiopathic PD (IPD) patients than in 101 healthy controls, who nevertheless showed as age‐dependent increases. By in vitro transfection, α‐SN expression was shown to be correlated with glucocorticoid sensitive apoptosis, possibly caused by the enhanced expression of glucocorticoid receptor (GR), caspase activations (caspase‐8, caspase‐9), CD95 up‐regulation, and reactive oxygen species (ROS) production. An understanding of the correlation between α‐SN levels and apoptosis in the presence of the coordinated involvement of multiple processes would provide an insight into the molecular basis of the disease. The present study provides a clue that the α‐SN may be one of the primary causes of the immune abnormalities observed in PD and offers new targets for pharmacotherapeutic intervention.

Plaque Rupture is a Determinant of Vascular Events in Carotid Artery Atherosclerotic Disease: Involvement of Matrix Metalloproteinases 2 and 9

Background and Purpose Unstable carotid atherosclerotic plaques are characterized by cap rupture, leading to thromboembolism and stroke. Matrix metalloproteinases (MMPs) have been implicated in the progression of atherosclerosis and plaque rupture. The aim of this study was to assess the relationship between the expressions of MMP-2 and MMP-9 and carotid plaque instability. Methods Eighty atherosclerotic plaques were collected from 74 patients undergoing carotid endarterectomy. Clinical information was obtained from each patient, and plaque morphology was examined at the macroscopic and microscopic levels. The immunohistochemical expressions of MMPs were graded using semiquantitative scales. Results Macroscopic ulceration (84.6% versus 63.4%, p=0.042) and microscopic cap rupture (79.5% versus 51.2%, p=0.010) were more common in symptomatic than in asymptomatic patients. Immunoreactivities of MMP-2 and MMP-9 were increased in 40 and 36 atheromatous plaques, respectively. Macroscopic ulceration was strongly correlated with the expressions of MMP-2 (p<0.001) and MMP-9 (p=0.001). There were significant correlations between increased MMP-2 expression and cap rupture (p=0.002), intraplaque hemorrhage (p=0.039), and a thin fibrous cap (p=0.002), and between increased MMP-9 expression and cap rupture (p=0.010) and a large lipid core (p=0.013). Conclusions Plaque rupture was significantly associated with the development of vascular events in carotid atherosclerotic disease. MMP-2 and MMP-9 are strongly correlated with plaque instability.

Hemichorea as an initial manifestation of moyamoya disease: Reversible striatal hypoperfusion demonstrated on single photon emission computed tomography

We describe a case with unilateral moyamoya disease that showed progressive hemichorea as an initial manifestation. Single photon emission computed tomography showed perfusion defect in the contralateral basal ganglia although magnetic resonance imaging was unremarkable. Hemichorea improved along with normalization of perfusion after bypass surgery, suggestive of striatal hypoperfusion as the cause of hemichorea.

Protective role of heat shock and heat shock protein 70 in lactacystin-induced cell death both in the rat substantia nigra and PC12 cells

Proteasomal dysfunction plays an important role in the pathogenesis of Parkinson disease (PD). Although clinical and experimental evidence continues to accumulate indicating heat shock protein 70 (HSP70) is significant in the pathogenesis of PD, few studies have been made to investigate the role of HSP70 under the condition of proteasome dysfunction. In in vivo study, we infused lactacystin into the unilateral substantia nigra (SN) of Sprague-Dawley rats with or without preceding whole body hyperthermia (WBH). Immunohistochemical studies showed the death of dopaminergic neurons and activated microglia in the SN. Lactacystin with prior WBH increased the expression of HSP70 more than did lactacystin alone and decreased lactacystin-induced dopaminergic neuronal death in the SN. In PC12 cells, heat shock pretreatment decreased lactacystin-induced cell death. Although additional treatment of nocodazole, ammonium chloride, and 3-methyladenine augmented cell death by lactacystin, heat shock pretreated to these drugs offsets their additional toxicity. These results indicate that heat shock proteins, especially HSP70, could play an important role under the condition of proteasome dysfunction in part by fostering aggresome formation and lysosome-mediated autophagy.

The G2019S LRRK2 mutation is rare in Korean patients with Parkinson's disease.

BACKGROUNDnA number of causative mutations such as alpha-synuclein, parkin, UCHL1, Pink-1, DJ-1 have been identified in Parkinsons disease (PD). They are usually found in the familial cases. One mutation of great interest is the G2019S mutation in the LRRK2 gene, which has been reported in both familial and sporadic PD. Its prevalence has been reported to vary markedly among different races. We examined the prevalence of the G2019S mutation in the Korean PD population for genetic study planning.nnnMETHODSnWe conducted a genetic analysis of the G2019S mutation by standard PCR and restriction digestion method. 453 PD patients were studied, 34% of whom had an age at onset of < 50 years and 3.8% had a positive family history.nnnRESULTSnNone of the 453 study subjects carried the G2019S mutation.nnnCONCLUSIONSnOur result confirms previous reports that the G2019S mutation is rare among PD patients in the Asian population. This result supports the notion that the prevalence of this LRRK2 mutation is population specific, and that there may be a founder effect within western populations.

BV-2 stimulation by lactacystin results in a strong inflammatory reaction and apoptotic neuronal death in SH-SY5Y cells.

Neuroinflammation plays a role in the pathomechanism of many neurodegenerative diseases, including Parkinson disease (PD). Proteasome inhibition has also been known to be involved in the pathology of PD. Recent studies have reported that microglial activation and dopaminergic cell death were observed in in vivo lactacystin-induced models of PD. In the present study, we investigated whether proteasome inhibition had a direct effect on the inflammatory reaction. Lactacystin treatment increased the amount of nitric oxide and tumor necrosis factor alpha (TNF-alpha) in culture media containing murine microglia (BV-2). Neuronal cell death was more pronounced when the culture media containing BV-2 cells (BV-2 conditioned media; BV-2 CM) were harvested and treated with human dopaminergic neurons (SH-SY5Y) than when treated with lactacystin alone. Apoptosis was markedly increased by treatment with BV-2 CM, which could be mitigated by pretreatment with minocycline and N(omega)-nitro-l-arginine methyl ester (L-NAME). These results suggest that proteasome inhibition can directly trigger neuroinflammation, which leads to neuronal death.

Amnesic syndrome in a mammillothalamic tract infarction.

It is controversial whether isolated lesions of mammillothalamic tract (MTT) produce significant amnesia. Since the MTT is small and adjacent to several important structures for memory, amnesia associated with isolated MTT infarction has been rarely reported. We report a patient who developed amnesia following an infarction of the left MTT that spared adjacent memory-related structures including the anterior thalamic nucleus. The patients memory deficit was characterized by a severe anterograde encoding deficit and retrograde amnesia with a temporal gradient. In contrast, he did not show either frontal executive dysfunction or personality change that is frequently recognized in the anterior or medial thalamic lesion. We postulate that an amnesic syndrome can develop following discrete lesions of the MTT.

A case of adult onset tic disorder following carbon monoxide intoxication.

BACKGROUNDnAdult onset tic disorders are usually secondary in origin. We report a case of adult onset tic disorder following carbon monoxide (CO) intoxication with typical magnetic resonance imaging features.nnnCASE REPORTnA 36-year-old woman developed temporarily suppressible patterned movements on her face, neck, and shoulder associated with sensory discomfort after CO poisoning. Magnetic resonance images showed bilateral symmetric cavitary changes in the globus pallidus. Clonazepam relieved much of her symptoms.nnnCONCLUSIONnOur patient developed a monosymptomatic tic disorder following CO intoxication. This further supports that altered outflow signals from the basal ganglia, especially the globus pallidus, may contribute to the development of tic disorders.

Overnight switch from ropinirole to transdermal rotigotine patch in patients with Parkinson disease

BackgroundA recent trial involving predominantly Caucasian subjects with Parkinson Disease (PD) showed switching overnight from an oral dopaminergic agonist to the rotigotine patch was well tolerated without loss of efficacy. However, no such data have been generated for Korean patients.MethodsThis open-label multicenter trial investigated PD patients whose symptoms were not satisfactorily controlled by ropinirole, at a total daily dose of 3 mg to 12 mg, taken as monotherapy or as an adjunct to levodopa. Switching treatment from oral ropinirole to transdermal rotigotine was carried out overnight, with a dosage ratio of 1.5:1. After a 28-day treatment period, the safety and tolerability of switching was evaluated. Due to the exploratory nature of this trial, the effects of rotigotine on motor and nonmotor symptoms of PD were analyzed in a descriptive manner.ResultsOf the 116 subjects who received at least one treatment, 99 (85%) completed the 28-day trial period. Dose adjustments were required for 11 subjects who completed the treatment period. A total of 76 treatment-emergent adverse events (AEs) occurred in 45 subjects. No subject experienced a serious AE. Thirteen subjects discontinued rotigotine prematurely due to AEs. Efficacy results suggested improvements in both motor and nonmotor symptoms and quality of life after switching. Fifty-two subjects (46%) agreed that they preferred using the patch over oral medications, while 31 (28%) disagreed.ConclusionsSwitching treatment overnight from oral ropinirole to transdermal rotigotine patch, using a dosage ratio of 1.5:1, was well tolerated in Korean patients with no loss of efficacy.Trial registrationThis trial is registered with the ClincalTrails.gov Registry (NCT00593606).

Post-stroke restless leg syndrome and periodic limb movements in sleep.

Primary restless leg syndrome (RLS) and periodic limb movements in sleep (PLMS) frequently co‐exist, obscuring the boundaries between the two conditions. In such instances, a study of secondary cases with focal lesions such as post‐stroke RLS and PLMS (psRLS and psPLMS, respectively) can be helpful in identifying characteristics of the individual conditions.