Extracellular Vesicles Released from Neprilysin Gene-Modified Human Umbilical Cord-Derived Mesenchymal Stem Cell Enhance Therapeutic Effects in an Alzheimer's Disease Animal Model.

Alzheimer's disease (AD) animal studies have reported that mesenchymal stem cells (MSCs) have therapeutic effects; however, clinical trial results are controversial. Neprilysin (NEP) is the main cleavage enzyme of ß-amyloid (Aß), which plays a major role in the pathology and etiology of AD. We evaluated whether transplantation of MSCs with NEP gene modification enhances the therapeutic effects in an AD animal model and then investigated these pathomechanisms. We manufactured NEP gene-enhanced human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) and intravenously transplanted them in Aß 1-42-injected AD animal models. We compared the differences in behavioral tests and immunohistochemical assays between four groups: normal, Aß 1-42 injection, naïve hUC-MSCs, and NEP-enhanced hUC-MSCs. Both naïve and NEP-enhanced hUC-MSC groups showed significant improvements in memory compared to the Aß 1-42 injection group. There was no significant difference between naïve and NEP-enhanced hUC-MSC groups. There was a significant decrease in Congo red, BACE-1, GFAP, and Iba-1 and a significant increase in BDNF, NeuN, and NEP in both hUC-MSC groups compared to the Aß 1-42 injection group. Among them, BDNF, NeuN, GFAP, Iba-1, and NEP showed more significant changes in the NEP-enhanced hUC-MSC group than in the naïve group. After stem cell injection, stem cells were not found. Extracellular vesicles (EVs) were equally observed in the hippocampus in the naïve and NEP-enhanced hUC-MSC groups. However, the EVs of NEP-enhanced hUC-MSCs contained higher amounts of NEP as compared to the EVs of naïve hUC-MSCs. Thus, hUC-MSCs affect AD animal models through stem cell-released EVs. Although there was no significant difference in cognitive function between the hUC-MSC groups, NEP-enhanced hUC-MSCs had superior neurogenesis and anti-inflammation properties compared to naïve hUC-MSCs due to increased NEP in the hippocampus by enriched NEP-possessing EVs. NEP gene-modified MSCs that release an increased amount of NEP within EVs may be a promising therapeutic option in AD treatment.

High Serum Levels of Resistin is Associated With Acute Cerebral Infarction.

BACKGROUND: The inflammatory process is involved in the pathogenesis of atherosclerosis and brain tissue injury following cerebral ischemia. Human resistin is a member of small cysteine-rich secreted proteins and has been implicated in inflammatory responses. This study investigated the association of serum resistin level with acute cerebral infarction (ACI). We also investigated its association with the short-term functional outcome. METHODS: This study included 106 patients with ACI and 106 age-matched and sex-matched healthy control subjects. Serum resistin level was assessed by using enzyme-linked immunosorbent sandwich assay. The association of serum resistin levels with ACI was analyzed by logistic regression analysis. RESULTS: The serum resistin level was significantly higher in patients with ACI than the control group [median (interquartile range), 35.7 ng/mL (13.0 to 70.5) ng/mL vs. 10.5 ng/ml (15.4 to 16.6), P<0.001]. Logistic regression analysis showed that serum resistin level was associated with an ACI (odds ratio=1.055, 95% confidence interval: 1.035-1.074, P<0.001). Among stroke subtypes, the serum resistin level was higher in the patients with large artery atherosclerosis than those with other subtypes (P=0.013). High resistin levels were also significantly associated with unfavorable functional outcome at discharge (odds ratio=1.043, 95% confidence interval: 1.024-1.063, P<0.001). CONCLUSIONS: This study suggests the potential association of resistin with stroke and cerebral atherosclerosis. Increased serum resistin levels were also associated with early unfavorable neurological outcome.

Effect of leukopenia induced by cyclophosphamide on the initial stage of arterial thrombosis in mice.

INTRODUCTION: Leukocytes are found in organizing thrombi and are associated with thrombus growth. However, their role in the initial stage of thrombus formation is not well known. We investigated the role of leukocytes in the early stage of arterial thrombosis by inducing leukopenia. METHODS: In this double-blind, randomized, placebo-controlled study, 72 Institute of Cancer Research mice were randomly treated with intraperitoneal 100 mg/kg cyclophosphamide or normal saline. The primary outcome was time to occlusion after FeCl3 treatment. We also compared thrombus size, histological composition, and association with peripheral blood cell counts between cyclophosphamide and control groups. RESULTS: Cyclophosphamide treatment significantly decreased leukocyte counts by 82.8% compared to placebo (P < 0.001). The time to occlusion was significantly longer in the cyclophosphamide group (3.31 ± 1.59 min) than in the control group (2.30 ± 1.14 min; P = 0.003). The immunoreactivity for Ly6G-positive cells, intracellular histone H3, and released histone H3 in thrombi was significantly reduced in the cyclophosphamide group by 92.8%, 50.2%, and 34.3%, respectively. Time to occlusion had a moderate negative correlation with leukocyte count in peripheral blood (r = -0.326, P = 0.022) in the entire group. CONCLUSIONS: Cyclophosphamide-induced leukopenia attenuated thrombus formation during the early stage of arterial thrombosis. Our findings suggest the potential role of leukocytes in the initial stage of arterial thrombosis.

Clinical impact of estradiol/testosterone ratio in patients with acute ischemic stroke.

BACKGROUND: Sex hormones may be associated with a higher incidence of ischemic stroke or stroke-related events. In observational studies, lower testosterone concentrations are associated with infirmity, vascular disease, and adverse cardiovascular risk factors. Currently, female sexual hormones are considered neuroprotective agents. The purpose of this study was to assess the role of sex hormones and the ratio of estradiol/testosterone (E/T) in patients with acute ischemic stroke (AIS). METHODS: Between January 2011 and December 2016, 146 male patients with AIS and 152 age- and sex-matched control subjects were included in this study. Sex hormones, including estradiol, progesterone, and testosterone, were evaluated in the AIS patient and control groups. We analyzed the clinical and physiological levels of sex hormones and hormone ratios in these patients. RESULTS: The E/T ratio was significantly elevated among patients in the stroke group compared to those in the control group (P = 0.001). Categorization of data into tertiles revealed that patients with the highest E/T ratio were more likely to have AIS [odds ratio (OR) 3.084; 95% Confidence interval (CI): 1.616-5.886; P < 0.001) compared with those in the first tertile. The E/T ratio was also an independent unfavorable outcome predictor with an adjusted OR of 1.167 (95% CI: 1.053-1.294; P = 0.003). CONCLUSIONS: These findings support the hypothesis that increased estradiol and reduced testosterone levels are associated with AIS in men.

Enhancing the Therapeutic Potential of CCL2-Overexpressing Mesenchymal Stem Cells in Acute Stroke.

Although intravenous administration of mesenchymal stem cells (MSCs) is effective for experimental stroke, low engraftment and the limited functional capacity of transplanted cells are critical hurdles for clinical applications. C-C motif chemokine ligand 2 (CCL2) is associated with neurological repair after stroke and delivery of various cells into the brain via CCL2/CCR2 (CCL2 receptor) interaction. In this study, after CCL2-overexpressing human umbilical cord-derived MSCs (hUC-MSCs) were intravenously transplanted with mannitol in rats with middle cerebral arterial occlusion, we compared the differences between four different treatment groups: mannitol + CCL2-overexpressing hUC-MSCs (CCL2-MSC), mannitol + naïve hUC-MSCs (M-MSC), mannitol only, and control. At four-weeks post-transplantation, the CCL2-MSC group showed significantly better functional recovery and smaller stroke volume relative to the other groups. Additionally, we observed upregulated levels of CCR2 in acute ischemic brain and the increase of migrated stem cells into these areas in the CCL2-MSC group relative to the M-MSC. Moreover, the CCL2-MSC group displayed increased angiogenesis and endogenous neurogenesis, decreased neuro-inflammation but with increased healing-process inflammatory cells relative to other groups. These findings indicated that CCL2-overexpressing hUC-MSCs showed better functional recovery relative to naïve hUC-MSCs according to the increased migration of these cells into brain areas of higher CCR2 expression, thereby promoting subsequent endogenous brain repair.

Factors associated with ischemic stroke on therapeutic anticoagulation in patients with nonvalvular atrial fibrillation.

PURPOSE: In this study, we investigated the stroke mechanism and the factors associated with ischemic stroke in patients with nonvalvular atrial fibrillation (NVAF) who were on optimal oral anticoagulation with warfarin. MATERIALS AND METHODS: This was a multicenter case-control study. The cases were consecutive patients with NVAF who developed cerebral infarction or transient ischemic attack (TIA) while on warfarin therapy with an international normalized ratio (INR) ≥2 between January 2007 and December 2011. The controls were patients with NVAF without ischemic stroke who were on warfarin therapy for more than 1 year with a mean INR ≥2 during the same time period. We also determined etiologic mechanisms of stroke in cases. RESULTS: Among 3569 consecutive patients with cerebral infarction or TIA who had NVAF, 55 (1.5%) patients had INR ≥2 at admission. The most common stroke mechanism was cardioembolism (76.0%). Multivariate analysis demonstrated that smoking and history of previous ischemic stroke were independently associated with cases. High CHADS2 score (≥3) or CHA2DS2-VASc score (≥5), in particular, with previous ischemic stroke along with ≥1 point of other components of CHADS2 score or ≥3 points of other components of CHA2DS2-VASc score was a significant predictor for development of ischemic stroke. CONCLUSION: NVAF patients with high CHADS2/CHA2DS2-VASc scores and a previous ischemic stroke or smoking history are at high risk of stroke despite optimal warfarin treatment. Some other measures to reduce the risk of stroke would be necessary in those specific groups of patients.

Cryptococcal meningitis in a patient with chronic hepatitis C treated with pegylated-interferon and ribavirin.

Various adverse events have been reported during combination therapy with pegylated (PEG)-interferon-α and ribavirin, although opportunistic infections, especially cryptococcal meningitis, are very rare. A 61-year-old woman complained of headaches and a fever during treatment of a chronic hepatitis C virus (HCV) infection. She had been treated for 7 months. Her headaches were refractory to analgesics, and she developed subtle nuchal rigidity. The cerebral spinal fluid (CSF) revealed a white blood cell count of 205/mm(3), 51 mg/dL protein, 35 mg/dL glucose, and negative Cryptococcus antigen. The CSF culture resulted in no growth. Five days later, the CSF was positive for Cryptococcus antigen. We administered amphotericin B and flucytosine, followed by fluconazole. Approximately 2 months later, she was discharged. For the first time, we report a case of cryptococcal meningitis during the treatment of chronic HCV with PEG-interferon-α and ribavirin.

Pattern of voiding dysfunction after acute brainstem infarction.

BACKGROUND: The purpose of this study is to compare the patterns of voiding dysfunction according to the locations of brainstem lesions. METHODS: Between November 2008 and December 2011, a total of 30 patients participated in this study. All 30 subjects, consisting of 16 men and 14 women, aged between 41 and 82 years (mean age, 63.0±11.0 years) underwent a urodynamic study within 7 days after the onset of a stroke. RESULTS: Twenty-one (70%) patients had a pontine lesion and 9 (30%) had a medullary lesion. Fourteen of these patients (46.7%) had bladder storage disorder, 7 patients (23.3%) had bladder emptying disorder, and 9 patients (30%) had a normal report. Five of the patients who had a medullary lesion (55.6%) had bladder emptying disorder, whereas only 2 patients who had a pontine lesion (9.5%) had bladder emptying disorder. Thirteen patients who had a pontine lesion (61.9%) showed bladder storage disorder. DISCUSSION: The descending pathway from the midbrain tegmentum is inhibitory, and the pathway from the pontine tegmentum is stimulatory. Because of their location pontine lesions could disrupt the descending fibers of the midbrain tegmentum and medullary lesions could disrupt the descending fibers of the pontine tegmentum.

Clinical, immunohistochemical, Western blot, and genetic analysis in dystrophinopathy.

Dystrophin-deficient muscular dystrophies (dystrophinopathies) are the most common form of muscular dystrophy, with variable clinical phenotypes ranging from the severe Duchenne (DMD) to the milder Becker (BMD) forms. In this study, we investigated the relationship between clinical characteristics, findings at immunohistochemistry (IHC) and Western blot, and the pattern of exon deletions in 24 male patients with dystrophinopathies. We retrospectively reviewed findings from clinical and laboratory examinations, IHC for dystrophin of muscle biopsy tissue, Western blot analysis, and multiplex polymerase chain reaction (PCR) examination of genomic DNA. All tests were performed in every patient. PCR examination revealed exon deletions in 13 patients (54.2%). At Western blot analysis, 15 patients (62.5%) were negative at all three dystrophin domains. Most of these patients had a clinical presentation consistent with the DMD phenotype. Nine (37.5%) others were weakly positive at one or more domains. Most of these patients presented clinically as BMD phenotype. One patient whose clinical presentation was consistent with BMD phenotype had normal findings at IHC and was weakly positive at all three domains on Western blot analysis; however, with the exception of this patient, the findings at IHC and Western blot were consistent for individual patients. Based on these findings, we conclude that Western blot analysis appears useful for confirmation of dystrophinopathy in BMD patients with normal staining on IHC. Exon deletion analysis by multiplex PCR using peripheral blood is also a simple and useful test for the diagnosis of dystrophinopathy, although it has limited sensitivity.

Elevated serum level of interleukin-32α in the patients with myasthenia gravis.

A new cytokine, interleukin-32 (IL-32), has been implicated in the pro-inflammatory immune responses in several autoimmune disorders, such as rheumatoid arthritis and inflammatory bowel diseases. Myasthenia gravis (MG) is a well-characterized autoimmune disease directed at the postsynaptic acetylcholine receptor (AChR) or end plate of the neuromuscular junction. IL-32 is a cytokine that induces tumor necrosis factor (TNF)-α, IL-6, IL-1ß, and chemokine. IL-6, TNF-α, and IL-2 are related to the pathogenesis and immunoregulation of MG. The gene expression of IL-32 is increased in human natural killer (NK) cells and T lymphocytes when stimulated by IL-2 or mitogen. NK cells influence the development of experimental autoimmune MG (EAMG) and possibly MG. The aim of this study was to examine whether IL-32α levels are increased in patients with MG and to investigate the relationship between IL-32α levels and disease activity in human MG. Serum IL-32α levels were significantly higher in the MG patients (p = 0.03): 460.07 ± 192.30 pg/mL in MG patients and 248.45 ± 188.42 pg/mL in the healthy control group. Although there was no significant statistical difference, serum IL-32α levels of patients with both anti-AChR binding and blocking antibodies trended to be higher than those without either antibodies (521.56 ± 212.92 pg/mL vs. 339.52 ± 182.78 pg/mL, p = 0.16). IL-32α serum levels tended to decrease with clinical improvement in generalized MG. This study suggests the possibility that IL-32 might contribute to MG pathogenesis or immunoregulation.

Eosinophilic vasculitis of the spinal cord associated with Churg-Strauss syndrome.

Eosinophilic vasculitis has been described as part of Churg-Strauss syndrome (CSS), but it also affects the central nervous system in <10% of cases. However, spinal cord involvement in CSS has not been reported. We report a patient with myelopathic symptoms, with a two-year history of asthma. Laboratory tests revealed leukocytosis, with 31.7% eosinophils. A chest computed tomographic scan and radiography showed patchy bilateral areas of consolidation, predominantly involving the peripheral regions of the lower lobes. Spinal cord magnetic resonance imaging (MRI) revealed high-signal-intensity lesions at the C3-C5 and T1-T4 spinal levels on T2-weighted images. A microscopic evaluation revealed an eosinophil-rich inflammatory infiltrate with fibroid necrosis of a vessel wall, and granuloma formation in the small veins was not clearly visible. To the best of our knowledge, this is the first case of eosinophilic vasculitis of the spinal cord associated with CSS, and the patient responded well to steroids.

A case of cerebral erdheim-chester disease with progressive cerebellar syndrome.

Erdheim-Chester disease (ECD) is a rare non-Langerhans form of histiocytosis. Cerebellar involvement is rare in this syndrome. We report a 37-year-old woman with slowly progressive cerebellar ataxia, dysmetria of limbs, nystagmus, and dysarthria, bilateral painful axillary masses, and generalized arthralgia. Brain MRI revealed cerebellar atrophy with focal lesions in the pons, middle cerebellar peduncle, and the cerebellum. She underwent incisional biopsy of her axillary masses which showed findings consistent with ECD. An MRI of her lower extremities revealed lesions in the diaphyses, metaphyses, and epiphyses of the proximal tibia and distal femur bilaterally. This is a rare case of cerebral ECD with progressive cerebellar syndrome associated with cerebellar atrophy.