Gyeong Joon Moon

Circulating Mesenchymal Stem Cells Microparticles in Patients with Cerebrovascular Disease

Preclinical and clinical studies have shown that the application of CD105+ mesenchymal stem cells (MSCs) is feasible and may lead to recovery after stroke. In addition, circulating microparticles are reportedly functional in various disease conditions. We tested the levels of circulating CD105+ microparticles in patients with acute ischemic stroke. The expression of CD105 (a surface marker of MSCs) and CXCR4 (a CXC chemokine receptor for MSC homing) on circulating microparticles was evaluated by flow cytometry of samples from 111 patients and 50 healthy subjects. The percentage of apoptotic CD105 microparticles was determined based on annexin V (AV) expression. The relationship between serum levels of CD105+/AV− microparticles, stromal cells derived factor-1α (SDF-1α), and the extensiveness of cerebral infarcts was also evaluated. CD105+/AV− microparticles were higher in stroke patients than control subjects. Correlation analysis showed that the levels of CD105+/AV− microparticles increased as the baseline stroke severity increased. Multivariate testing showed that the initial severity of stroke was independently associated with circulating CD105+/AV− microparticles (OR, 1.103 for 1 point increase in the NIHSS score on admission; 95% CI, 1.032–1.178) after adjusting for other variables. The levels of CD105+/CXCR4+/AV− microparticles were also increased in patients with severe disability (r = 0.192, p = 0.046 for NIHSS score on admission), but were decreased with time after stroke onset (r = −0.204, p = 0.036). Risk factor profiles were not associated with the levels of circulating microparticles or SDF-1α. In conclusion, our data showed that stroke triggers the mobilization of MSC-derived microparticles, especially in patients with extensive ischemic stroke.

Albumin therapy in acute stroke patients

AbstractPreclinical studies have recently shown that albumin has neuroprotective effects for stroke in animal models. Thus, we sought to evaluate the effects of albumin therapy in patients with acute cerebral infarcts. We prospectively studied 49 patients with moderate-to-severe cerebral infarcts within the middle cerebral arterial territory into one of two groups: the control group (N = 18) received saline, whereas the albumin group (N = 31) received either 40 g or 80 g of albumin within 24 h from symptom onset. The modified National Institutes of Health Stroke Scale (mNIHSS) and diffusionweighted imaging (DWI) were serially checked. There was no adverse effect related to albumin therapy. Although there was no significant difference in both baseline mNIHSS score and DWI lesion volume on admission, the mNIHSS scores at the 14th day after treatment and the increase in DWI lesion volume 72–96 h after treatment were significantly reduced in patients of the albumin group (p = 0.001 and 0.012, respectively); these effects were dose- and timerelated. The outcome on the 90th day after stroke onset was more favorable in the albumin group than in the control group. Within the albumin group, patients who had patent or recanalized vessels showed more significant improvement than patient without recanalization (p = 0.046). Our results indicate that albumin therapy is a safe and effective modality in patients with acute cerebral infarction. This study also suggests that the effects of albumin therapy may vary depending on vessel status of the patient.

Effects of collagen-induced rheumatoid arthritis on amyloidosis and microvascular pathology in APP/PS1 mice

BackgroundEvidence suggests that rheumatoid arthritis (RA) may enhance or reduce the progression of Alzheimers disease (AD). The present study was performed to directly explore the effects of collagen-induced rheumatoid arthritis (CIA) on amyloid plaque formation, microglial activation, and microvascular pathology in the cortex and hippocampus of the double transgenic APP/PS1 mouse model for AD. Wild-type or APP/PS1 mice that received type II collagen (CII) in complete Freunds adjuvant (CFA) at 2 months of age revealed characteristics of RA, such as joint swelling, synovitis, and cartilage and bone degradation 4 months later. Joint pathology was accompanied by sustained induction of IL-1β and TNF-α in plasma over 4 weeks after administration of CII in CFA.ResultsCIA reduced levels of soluble and insoluble amyloid beta (Aβ) peptides and amyloid plaque formation in the cortex and hippocampus of APP/PS1 mice, which correlated with increased blood brain barrier disruption, Iba-1-positive microglia, and CD45-positive microglia/macrophages. In contrast, CIA reduced vessel density and length with features of microvascular pathology, including vascular segments, thinner vessels, and atrophic string vessels.ConclusionsThe present findings suggest that RA may exert beneficial effects against Aβ burden and harmful effects on microvascular pathology in AD.

Cancer Cell-Derived Extracellular Vesicles Are Associated with Coagulopathy Causing Ischemic Stroke via Tissue Factor-Independent Way: The OASIS-CANCER Study

Background Cancer and stroke, which are known to be associated with one another, are the most common causes of death in the elderly. However, the pathomechanisms that lead to stroke in cancer patients are not well known. Circulating extracellular vesicles (EVs) play a role in cancer-associated thrombosis and tumor progression. Therefore, we hypothesized that cancer cell-derived EVs cause cancer-related coagulopathy resulting in ischemic stroke. Methods Serum levels of D-dimer and EVs expressing markers for cancer cells (epithelial cell adhesion molecule [CD326]), tissue factor (TF [CD142]), endothelial cells (CD31+CD42b-), and platelets (CD62P) were measured using flow cytometry in (a) 155 patients with ischemic stroke and active cancer (116 − cancer-related, 39 − conventional stroke mechanisms), (b) 25 patients with ischemic stroke without cancer, (c) 32 cancer patients without stroke, and (d) 101 healthy subjects. Results The levels of cancer cell-derived EVs correlated with the levels of D-dimer and TF+ EVs. The levels of cancer cell-derived EVs (CD326+ and CD326+CD142+) were higher in cancer-related stroke than in other groups (P<0.05 in all the cases). Path analysis showed that cancer cell-derived EVs are related to stroke via coagulopathy as measured by D-dimer levels. Poor correlation was observed between TF+ EV and D-dimer, and path analysis demonstrated that cancer cell-derived EVs may cause cancer-related coagulopathy independent of the levels of TF+ EVs. Conclusions Our findings suggest that cancer cell-derived EVs mediate coagulopathy resulting in ischemic stroke via TF-independent mechanisms.

Efficient scalable production of therapeutic microvesicles derived from human mesenchymal stem cells

Microvesicles (MVs) released by cells are involved in a multitude of physiological events as important mediators of intercellular communication. MVs derived from mesenchymal stem cells (MSCs) contain various paracrine factors from the cells that primarily contribute to their therapeutic efficacy observed in numerous clinical trials. As nano-sized and bi-lipid layered vesicles retaining therapeutic potency equivalent to that of MSCs, MSC-derived MVs have been in focus as ideal medicinal candidates for regenerative medicine, and are preferred over MSC infusion therapy with their improved safety profiles. However, technical challenges in obtaining sufficient amounts of MVs have limited further progress in studies and clinical application. Of the multiple efforts to reinforce the therapeutic capacity of MSCs, few studies have reportedly examined the scale-up of MSC-derived MV production. In this study, we successfully amplified MV secretion from MSCs compared to the conventional culture method using a simple and efficient 3D-bioprocessing method. The MSC-derived MVs produced in our dynamic 3D-culture contained numerous therapeutic factors such as cytokines and micro-RNAs, and showed their therapeutic potency in in vitro efficacy evaluation. Our results may facilitate diverse applications of MSC-derived MVs from the bench to the bedside, which requires the large-scale production of MVs.

Brain microangiopathy and macroangiopathy share common risk factors and biomarkers.

AIMS Besides carotid or cardiac embolism, stroke can occur via microangiopathy (small arterial disease [SAD]) and macroangiopathy (intracranial atherosclerotic stroke [ICAS]) of the intracranial vasculature. There have been efforts to identify risk factors specific to microangiopathy and macroangiopathy, including vascular risk factors, and protein and genetic biomarkers. We hypothesized that despite the anatomic and pathophysiological differences between microvessels and macrovessels, microangiopathy and macroangiopathy share common risk factors during disease progression. METHODS Among 714 patients with acute infarctions within middle cerebral artery territory, 126 with SAD and 116 with ICAS were included in this study. Subclinical microangiopathy (degree of leukoaraiosis) and macroangiopathy (number of tandem stenosis) was graded in each patient. Inflammatory biomarkers (C-reactive protein, E-selectin, and LpPLA2), endothelial dysfunction (asymmetric dimethylarginine, urinary albumin-to-creatinine ratio, endostatin, and homocysteine), atherogenesis (lipoprotein(a), adiponectin, and resistin), and renal function (creatinine clearance and estimated glomerular filtration rate) were assessed. RESULTS Compared with the patients with isolated SAD, those with isolated ICAS were younger, were current smokers, and showed higher apoB levels (p < 0.05 in all cases). However, with the progression of subclinical microangiopathy, asymptomatic macroangiopathy worsened and vice versa. No significant differences in risk factors were observed between advanced SAD and ICAS. Decreased renal function was independently associated with progression of microangiopathy and macroangiopathy. Markers of endothelial dysfunction, but not the other markers, were significantly related to creatinine clearance level. CONCLUSIONS Mild to moderate loss of renal function is strongly associated with both intracranial microangiopathy and macroangiopathy. Endothelial dysfunction may be associated with this relationship.

Role of High-Resolution Magnetic Resonance Imaging in the Diagnosis of Primary Angiitis of the Central Nervous System

BACKGROUND Primary angiitis of the central nervous system (PACNS) is a rare disorder and is often difficult to diagnose due to the lack of a confirmatory test. PACNS can generally be diagnosed based on typical angiographic findings. We describe herein a patient diagnosed with PACNS despite the presence of normal findings on conventional angiography. CASE REPORT A 44-year-old man with a recent history of ischemic stroke in the right posterior cerebral artery territory developed acute-onset vertigo. Diffusion-weighted imaging revealed an acute infarction within the left posterior inferior cerebellar artery. His medical history was unremarkable except for hyperlipidemia; the initial examination revealed mild gait imbalance. During the 10 days of hospital admission, the patient experienced four recurrent ischemic strokes within the posterior circulation territory (occipital lobe, pons, and cerebellum). He was diagnosed with recurrent cerebral infarctions due to PACNS. The basilar artery exhibited no demonstrable luminal stenosis, but there were direct imaging signs of central nervous system angiitis including wall thickening and contrast enhancement. High-dose intravenous steroid therapy followed by oral prednisolone was administered. There was no further stroke recurrence and follow-up imaging of the arterial walls showed normalization of their characteristics. CONCLUSIONS The present case emphasizes the importance of wall imaging in the diagnosis and treatment of PACNS.

Distinct Roles of Endothelial Dysfunction and Inflammation in Intracranial Atherosclerotic Stroke

Background/Aims: The aim of the study was to evaluate the differential roles of endothelial dysfunction and inflammation in intracranial atherosclerotic stroke (ICAS). Methods: We prospectively recruited 262 patients with acute cerebral infarcts caused by ICAS and 75 individuals with no history of stroke as controls. Markers of endothelial dysfunction (asymmetric dimethylarginine, ADMA) and inflammation (lipoprotein-associated phospholipase A2, Lp-PLA2) were measured. Acute ischemic lesions were measured in terms of their size, composition, and patterns. Subclinical microangiopathy (degree of leukoaraiosis) and macroangiopathy (presence/number of asymptomatic stenoses) were graded in each patient. Results: Compared to normal controls, serum levels of ADMA (0.69 ± 0.14 vs. 0.47 ± 0.10, p < 0.001) and Lp-PLA2 (138.1 ± 116.8 vs. 19.0 ± 58.0, p < 0.001) were elevated in patients with ICAS. A high ADMA serum level was associated with greater prevalence of preclinical microangiopathy and macroangiopathy. Contrastingly, an elevated serum Lp-PLA2 level was associated with larger ischemic lesions, a greater number of lesions, and a larger cortical pattern. Conclusions: Endothelial dysfunction and inflammation have distinct effects in ICAS patents; endothelial dysfunction is associated with the underlying micro- and macro-atherosclerotic burden, whereas inflammation is associated with acute infarct volume and pattern.