Mesenchymal Stem Cell-Extracellular Vesicle Therapy for Stroke: Scalable Production and Imaging Biomarker Studies.

A major clinical hurdle to translate MSC-derived extracellular vesicles (EVs) is the lack of a method to scale-up the production of EVs with customized therapeutic properties. In this study, we tested whether EV production by a scalable 3D-bioprocessing method is feasible and improves neuroplasticity in animal models of stroke using MRI study. MSCs were cultured in a 3D-spheroid using a micro-patterned well. The EVs were isolated with filter and tangential flow filtration and characterized using electron microscopy, nanoparticle tracking analysis, and small RNA sequencing. Compared to conventional 2D culture, the production-reproduction of EVs (the number/size of particles and EV purity) obtained from 3D platform were more consistent among different lots from the same donor and among different donors. Several microRNAs with molecular functions associated with neurogenesis were upregulated in EVs obtained from 3D platform. EVs induced both neurogenesis and neuritogenesis via microRNAs (especially, miR-27a-3p and miR-132-3p)-mediated actions. EV therapy improved functional recovery on behavioral tests and reduced infarct volume on MRI in stroke models. The dose of MSC-EVs of 1/30 cell dose had similar therapeutic effects. In addition, the EV group had better anatomical and functional connectivity on diffusion tensor imaging and resting-state functional MRI in a mouse stroke model. This study shows that clinical-scale MSC-EV therapeutics are feasible, cost-effective, and improve functional recovery following experimental stroke, with a likely contribution from enhanced neurogenesis and neuroplasticity.

Metformin acts as a dual glucose regulator in mouse brain.

Aims: Metformin improves glucose regulation through various mechanisms in the periphery. Our previous study revealed that oral intake of metformin activates several brain regions, including the hypothalamus, and directly activates hypothalamic S6 kinase in mice. In this study, we aimed to identify the direct effects of metformin on glucose regulation in the brain. Materials and methods: We investigated the role of metformin in peripheral glucose regulation by directly administering metformin intracerebroventricularly in mice. The effect of centrally administered metformin (central metformin) on peripheral glucose regulation was evaluated by oral or intraperitoneal glucose, insulin, and pyruvate tolerance tests. Hepatic gluconeogenesis and gastric emptying were assessed to elucidate the underlying mechanisms. Liver-specific and systemic sympathetic denervation were performed. Results: Central metformin improved the glycemic response to oral glucose load in mice compared to that in the control group, and worsened the response to intraperitoneal glucose load, indicating its dual role in peripheral glucose regulation. It lowered the ability of insulin to decrease serum glucose levels and worsened the glycemic response to pyruvate load relative to the control group. Furthermore, it increased the expression of hepatic G6pc and decreased the phosphorylation of STAT3, suggesting that central metformin increased hepatic glucose production. The effect was mediated by sympathetic nervous system activation. In contrast, it induced a significant delay in gastric emptying in mice, suggesting its potent role in suppressing intestinal glucose absorption. Conclusion: Central metformin improves glucose tolerance by delaying gastric emptying through the brain-gut axis, but at the same time worsens it by increasing hepatic glucose production via the brain-liver axis. However, with its ordinary intake, central metformin may effectively enhance its glucose-lowering effect through the brain-gut axis, which could surpass its effect on glucose regulation via the brain-liver axis.

Circulating Extracellular-Vesicle-Incorporated MicroRNAs as Potential Biomarkers for Ischemic Stroke in Patients With Cancer.

BACKGROUND AND PURPOSE: This study aimed to evaluate whether extracellular-vesicle-incorporated microRNAs (miRNAs) are potential biomarkers for cancer-related stroke. METHODS: This cohort study compared patients with active cancer who had embolic stroke of unknown sources (cancer-stroke group) with patients with only cancer, patients with only stroke, and healthy individuals (control groups). The expression profiles of miRNAs encapsulated in plasma exosomes and microvesicles were evaluated using microarray and validated using quantitative real-time polymerase chain reaction. The XENO-QTM miRNA assay technology was used to determine the absolute copy numbers of individual miRNAs in an external validation cohort. RESULTS: This study recruited 220 patients, of which 45 had cancer-stroke, 76 were healthy controls, 39 were cancer controls, and 60 were stroke controls. Three miRNAs (miR-205-5p, miR-645, and miR-646) were specifically incorporated into microvesicles in patients with cancer-related stroke, cancer controls, and stroke controls. The area under the receiver operating characteristic curves of these three miRNAs were 0.7692-0.8510 for the differentiation of patients with cancer-stroke from cancer-controls and 0.8077-0.8846 for the differentiation of patients with cancer-stroke from stroke controls. The levels of several miRNAs were elevated in the plasma exosomes of patients with cancer, but were lower than those in plasma microvesicles. An in vivo study showed that systemic injection of miR-205-5p promoted the development of arterial thrombosis and elevation of D-dimer levels. CONCLUSION: Stroke due to cancer-related coagulopathy was associated with deregulated expression of miRNAs, particularly microvesicle-incorporated miR-205-5p, miR-645, and miR-646. Further prospective studies of extracellular-vesicle-incorporated miRNAs are required to confirm the diagnostic role of miRNAs in patients with stroke and to screen the roles of miRNAs in patients with cancer.

Circulating Extracellular Vesicles in Stroke Patients Treated With Mesenchymal Stem Cells: A Biomarker Analysis of a Randomized Trial.

BACKGROUND: Mesenchymal stem cells (MSCs) secrete trophic factors and extracellular vesicles (EVs). However, the level and role of EVs after MSC therapy in patients with stroke are unknown. We investigated whether circulating EVs and trophic factors are increased after MSCs and are related to the therapeutic benefits in the STARTING-2 trial (Stem Cell Application Researches and Trials in Neurology-2) participants. METHODS: In this prospective randomized controlled trial, patients with chronic major stroke were assigned, in a 2:1 ratio, to receive autologous MSC intravenous injection (MSC group, n=39) or standard treatment (control group, n=15) and followed for 3 months. Detailed clinical assessment and neuroplasticity on diffusion tensor image and resting-state functional magnetic resonance imaging were evaluated. Serial samples were collected, before/after MSCs therapy. The primary outcome measure was circulating factors that are associated with the clinical improvement in the Fugl-Meyer Assessment (secondary end point of the trial) and neuroplasticity on diffusion tensor image and resting-state functional magnetic resonance imaging. Additional outcome measures were microRNAs and trophic factors enriched in the plasma EVs, obtained using quantitative polymerase chain reaction and ELISA, respectively. RESULTS: Circulating EV levels were increased ≈5-fold (mean±SD, from 2.7×109±2.2×109 to 1.3×1010±1.7×1010 EVs/mL) within 24 hours after injection of MSCs (P=0.001). After adjustment of age, sex, baseline stroke severity, and the time interval from stroke onset to treatment, only the EV number was independently associated with improvement in motor function (odds ratio, 5.718 for EV numberLog [95% CI, 1.144-28.589]; P=0.034). Diffusion tensor image and resting-state functional magnetic resonance imaging showed that integrity of the ipsilesional corticospinal tract and intrahemispheric motor network were significantly correlated with circulating EV levels, respectively (P<0.05). MicroRNAs related to neurogenesis/neuroplasticity (eg, microRNA-18a-5p) were significantly increased in circulating EVs after MSC therapy (P=0.0479). In contrast, trophic factor levels were not changed after MSC therapy. CONCLUSIONS: This trial is the first to show that treatment of ischemic stroke patients with MSCs significantly increases circulating EVs, which were significantly correlated with improvement in motor function and magnetic resonance imaging indices of plasticity. REGISTRATION: URL: https://www. CLINICAL TRIALS: gov; Unique identifier: NCT01716481.

Circulating DNAs, a Marker of Neutrophil Extracellular Traposis and Cancer-Related Stroke: The OASIS-Cancer Study.

Background and Purpose- The role of circulating neutrophil extracellular traps (NETs) in cancer-related stroke is unknown. Methods- We conducted a prospective cohort study to test whether NETs are increased in cancer-related stroke and whether elevated NETs levels are associated with coagulopathy, assessed using D-dimer levels (≥2 µg/mL). Plasma DNA and nucleosome were assessed as NET-specific biomarkers. Results- In total, 138 patients were recruited; 38 patients had cancer-related stroke (active cancer and acute cryptogenic embolic stroke), 33 patients were healthy-controls, 27 patients were cancer-controls (active cancer but no stroke), and 40 patients were stroke-controls (acute ischemic stroke but no cancer). Plasma DNA and nucleosome levels were significantly elevated in cancer-related stroke patients than in healthy-controls (P<0.05). These levels were correlated with the D-dimer levels (P<0.01). In multiple regression analyses, increased plasma DNA levels were associated with cancer-related stroke (odds ratio=11.65 for highest quartile; 95% CI, 3.199-42.46) and D-dimer levels of ≥2 µg/mL (odds ratio=19.09 for highest quartile; 95% CI, 4.143-87.95) after adjusting for possible confounders. Conclusions- Increased circulating DNA levels were associated with cancer-related stroke, suggesting that NETosis is one of the molecular mechanisms of cancer-related stroke. Further long-term follow-up studies in large cohorts are needed to confirm the role of NET-specific biomarkers.

Cav-1 (Caveolin-1) and Arterial Remodeling in Adult Moyamoya Disease.

Background and Purpose- Moyamoya disease (MMD) is a unique cerebrovascular occlusive disease characterized by progressive stenosis and negative remodeling of the distal internal carotid artery (ICA). We hypothesized that cav-1 (caveolin-1)-a protein that controls the regulation of endothelial vesicular trafficking and signal transduction-is associated with negative remodeling in MMD. Methods- We prospectively recruited 77 consecutive patients with MMD diagnosed via conventional angiography. Seventeen patients with intracranial atherosclerotic stroke and no RNF213 mutation served as controls. The outer distal ICA diameters were examined using high-resolution magnetic resonance imaging. We evaluated whether the degree of negative remodeling in the patients with MMD was associated with RNF213 polymorphism, cav-1 levels, or various clinical and vascular risk factors. We also investigated whether the derived factor was associated with negative remodeling at the cellular level using the tube formation and apoptosis assays. Results- The serum cav-1 level was lower in the patients with MMD than in the controls (0.47±0.29 versus 0.86±0.68 ng/mL; P=0.034). The mean ICA diameter was 2.48±0.98 mm for the 126 affected distal ICAs in patients with MMD and 3.84±0.42 mm for the asymptomatic ICAs in the controls ( P<0.001). After adjusting for confounders, cav-1 levels (coefficient, 1.018; P<0.001) were independently associated with the distal ICA diameter in patients with MMD. In vitro analysis showed that cav-1 downregulation suppressed angiogenesis in the endothelial cells and induced apoptosis in the smooth muscle cells. Conclusions- Our findings suggest that cav-1 may play a major role in negative arterial remodeling in MMD.

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.

The effect of Korean Red Ginseng extract on rosiglitazone-induced improvement of glucose regulation in diet-induced obese mice.

BACKGROUND: Korean Red Ginseng extract (KRG, Panax ginseng Meyer) and its constituents have been used for treating diabetes. However, in diet-induced obese mice, it is unclear whether KRG can enhance the glucose-lowering action of rosiglitazone (ROSI), a peroxisome proliferator-activated receptor gamma synthetic activator. METHODS: Oral glucose tolerance tests (oGTTs) were performed after 4 days of treatment with a vehicle (CON), KRG [500 mg/kg body weight (b.w.)], ROSI (3.75 mg/kg b.w, 7.5 mg/kg b.w, and 15 mg/kg b.w.), or ROSI and KRG (RK) in obese mice on a high-fat diet. Adipose tissue morphology, crown-like structures (CLSs), and inflammation were compared by hematoxylin-eosin staining or quantitative reverse transcription polymerase chain reaction. RESULTS: The area under the glucose curve (AUC) was significantly lower in the RK group (15 mg/kg b.w. and 500 mg/kg b.w. for ROSI and KRG, respectively) than in the CON group. There was no significant difference in the AUC between the CON and the other groups. Furthermore, the AUC was significantly lower in the RK group than in the ROSI group. The expression of the Ccl2 gene and the number of CLSs were significantly reduced in the RK group than in the CON group. CONCLUSION: Our results show a potential enhancement of ROSI-induced improvement of glucose regulation by the combined treatment with KRG.

Caveolin-1, Ring finger protein 213, and endothelial function in Moyamoya disease.

BACKGROUND: Moyamoya disease is a unique cerebrovascular occlusive disease of unknown etiology. Ring finger protein 213 (RNF213) was identified as a susceptibility gene for Moyamoya disease in East Asian countries. However, the pathogenesis of Moyamoya disease remains unclear. METHODS: We prospectively analyzed clinical data for 139 patients with Moyamoya disease (108 bilateral Moyamoya disease, 31 unilateral Moyamoya disease), 61 patients with intracranial atherosclerotic stroke, and 68 healthy subjects. We compared the genetic (RNF213 variant) and protein biomarkers for caveolae (caveolin-1), angiogenesis (vascular endothelial growth factor (VEGF) and receptor (VEGFR2), and antagonizing cytokine (endostatin)) and endothelial dysfunction (asymmetric dimethylarginine (ADMA), and nitric oxide and its metabolites (nitrite and nitrate)) between patients with Moyamoya disease and intracranial atherosclerotic stroke. We then performed path analysis to evaluate whether a certain protein biomarker mediates the association between genes and Moyamoya disease. RESULTS: Caveolin-1 level was decreased in patients with Moyamoya disease and markedly decreased in RNF213 variant carriers. Circulating factors such as VEGF and VEGFR2 did not differ among the groups. Markers for endothelial dysfunction were significantly higher in patients with intracranial atherosclerotic stroke but normal in those with Moyamoya disease. Path analysis showed that the presence of the RNF213 variant was associated with caveolin-1 levels that could lead to Moyamoya disease. The level of combined marker of Moyamoya disease (caveolin-1) and intracranial atherosclerotic stroke (ADMA, an endothelial dysfunction marker) predicted Moyamoya disease with good sensitivity and specificity. CONCLUSION: Our results suggest that Moyamoya disease is a caveolae disorder but is not related to endothelial dysfunction or dysregulation of circulating cytokines.

The effect of metformin on neuronal activity in the appetite-regulating brain regions of mice fed a high-fat diet during an anorectic period.

Metformin reduces body weight by decreasing food intake in humans and animals. However, the brain regions involved in metformin-induced anorexia remain unclear. Therefore, we investigated c-Fos expression (FOS), a marker of neuronal activity, in the appetite-regulating brain regions after oral administration of metformin (PO, 300mg/kg daily for 1 or 3days) or vehicle. The body weight and food intake decreased in mice treated with metformin for 3days (RM group) and mice that had the same amount of food as the RM group (Pair-fed group; PF) compared to the control group. FOS expression levels increased in the paraventricular nucleus, area postrema, and central amygdala of mice administered an acute single dose of metformin (SM group) compared to the control mice. In the nucleus tractus solitarius, the FOS expression levels increased in both the SM and RM groups compared to the control group. The FOS expression levels also increased in the nucleus accumbens of the RM group compared to other groups. The FOS expression levels decreased in the ventromedial hypothalamic nucleus in the PF group, but not the RM group, compared to the control group, suggesting a potential hypothalamic area involvement for metformin-induced anorexia. These results suggest that both the hypothalamic and extra-hypothalamic regions are associated with metformin-induced anorexia, which is dependent on metformin treatment duration.

Nitric oxide overcomes Cd and Cu toxicity in in vitro-grown tobacco plants through increasing contents and activities of rubisco and rubisco activase.

Toxic heavy metals such as cadmium (Cd) and copper (Cu) are global problems that are a growing threat to the environment. Despite some heavy metals are required for plant growth and development, others are considered toxic elements and do not play any known physiological role in plant cells. Elevated doses of Cd or Cu cause toxicity in plants and generate damages due to the stress condition and eventually cause a significant reduction in quantity and quality of crop plants. The nitric oxide (NO) donor sodium nitroprusside (SNP) is reported to alleviate the toxicity of some heavy metals like Cd and Cu. In the current study, the role of NO in alleviating stresses of Cd and Cu was investigated in in vitro-grown tobacco (Nicotiana tabacum) Based on plant growth, total chlorophyll contents, contents and activities of rubisco and rubisco activase. According to the results of this study, the growth and total chlorophyll contents of Cd/Cu stressed plants were hugely decreased in the absence of SNP, while the supplementation of SNP resulted in a significant increase of both fresh weight and total chlorophyll contents. Remarkable reductions of Rubisco and rubisco activase contents and activities were observed in Cd and Cu-induced plants. SNP supplementation showed the highest contents and activities of rubisco and rubisco activase compared to the control and Cu/Cd-stressed plants. Taken together, our findings suggest that SNP could play a protective role in regulation of plant responses to abiotic stresses such as Cd and Cu by enhancing Rubisco and Rubisco activase.

Central administration of metformin into the third ventricle of C57BL/6 mice decreases meal size and number and activates hypothalamic S6 kinase.

Administration of metformin is known to reduce both body weight and food intake. Although the hypothalamus is recognized as a critical regulator of energy balance and body weight, there is currently no evidence for an effect of metformin in the hypothalamus. Therefore, we sought to determine the central action of metformin on energy balance and body weight, as well as its potential involvement with key hypothalamic energy sensors, including adenosine monophosphate-activated protein kinase (AMPK) and S6 kinase (S6K). We used meal pattern analysis and a conditioned taste aversion (CTA) test and measured energy expenditure in C56BL/6 mice administered metformin (0, 7.5, 15, or 30 µg) into the third ventricle (I3V). Furthermore, we I3V-administered either control or metformin (30 µg) and compared the phosphorylation of AMPK and S6K in the mouse mediobasal hypothalamus. Compared with the control, I3V administration of metformin decreased body weight and food intake in a dose-dependent manner and did not result in CTA. Furthermore, the reduction in food intake induced by I3V administration of metformin was accomplished by decreases in both nocturnal meal size and number. Compared with the control, I3V administration of metformin significantly increased phosphorylation of S6K at Thr(389) and AMPK at Ser(485/491) in the mediobasal hypothalamus, while AMPK phosphorylation at Thr(172) was not significantly altered. Moreover, I3V rapamycin pretreatment restored the metformin-induced anorexia and weight loss. These results suggest that the reduction in food intake induced by the central administration of metformin in the mice may be mediated by activation of S6K pathway.

Assessment of pharmacoeconomic evaluations submitted for reimbursement in Korea.

OBJECTIVE: To assess the quality of pharmacoeconomic evaluations (PEs) submitted with new drug applications for reimbursement and to investigate the role of PEs for coverage decisions in Korea. METHODS: Forty-seven PEs that were submitted by pharmaceutical companies for coverage decisions between June 2005 and December 2009 were included in this study. To assess their appropriateness with regard to the PE guidelines, we used the Health Insurance Review and Assessment services (HIRA) checklist consisting of 20 items based on the PE guidelines. We also evaluated the results for coverage decisions, as "recommended," "recommended with restricted use," or "not recommended," based on the incremental cost-effectiveness ratio and the range of uncertainty. RESULTS: On average, 14 of the 20 items on the HIRA checklist were fulfilled (70.9%, range 35.0%-100%). The compliance rate for the following items was above 70%: presentation of perspectives and evaluation methods, a sufficient time horizon, and appropriateness of comparators and health outcomes. The compliance rate for the following items was below 70%: omission of objectives for the study, inappropriate target population, unclear selection process for effectiveness and cost, inappropriate cost estimation, insufficient justification of generalizability, and description of study limitations. The range of incremental cost-effectiveness ratios per quality-adjusted life-years of PEs from a societal perspective varied from dominant to 59K USD (n = 13): it consisted of dominant to 28K USD for "recommended" submissions (n = 6), 8K to 20K USD for "recommended with restricted use" submissions (n = 4), and 13K to 59K for "not recommended" ones (n = 3). CONCLUSIONS: Our study showed that most PEs in this study have reached an adequate level for coverage decisions. Overall barriers associated with a lack of relevant evidence could account for the low compliance rate with specific items in the PE guidelines. PEs with good quality submitted for coverage decisions have played an important role for selecting cost-effective drugs.