Angiogenesis effect of udenafil in a caveolin-1 deficient moyamoya disease model: A pre-clinical animal study

Purpose Although pathogenic mechanisms of moyamoya disease (MMD) remain unknown, recent studies suggest that it is a caveolae disease. This study evaluated the effect of udenafil, a phosphodiesterase-5 inhibitor, on angiogenesis in in vitro and in vivo MMD models. Methods Angiogenesis and vessel maturation were assessed in in vitro models, caveolin- 1 (Cav-1) knockdown human umbilical vessel endothelial cells (HUVECs) and coronary artery smooth muscle cells (CASMCs), and in in vivo model of bilateral internal carotid artery occlusion (bICAo). Udenafil was administered (1,3,10, and 30 μM) in cell culture conditions, and functional studies (migration and tube formation assay) were performed and vessel maturation factors and cyclic guanosine monophosphate (cGMP) accumulation were measured. Results Udenafil (3 and 10 mg/kg) was orally administered once daily for 4 weeks in bICAo rat model, and histological analysis for angiogenesis and vessel maturation was performed. Udenafil increased vessel formation in both Cav-1 knockdown HUVEC and bICAo models without increased migration/proliferation of HUVECs and CASMCs. Udenafil increased CD31+ vessel density and NG2/Col4+ mural cell density in bICAo models. Cav-1 knockdown inhibited accumulation of cGMP, and udenafil treatment restored cGMP levels in Cav-1 knockdown HUVEC models. Vessel maturation factors (angiopoietin- 1 and platelet-derived growth factor receptor-β) and angiogenic factors (endothelial nitric oxide synthase) were increased after treatment with udenafil in vitro. Conclusion Our results indicate that udenafil reversed cellular levels of cGMP related to Cav-1 deficiency and induced angiogenesis and vessel maturation. Further studies are warranted to confirm the therapeutic effects of this strategy in MMD

Development of Anthropometry-Based Equations for the Estimation of the Total Body Water in Koreans

For developing race-specific anthropometry-based total body water (TBW) equations, we measured TBW using bioelectrical impedance analysis (TBWBIA) in 2,943 healthy Korean adults. Among them, 2,223 were used as a reference group. Two equations (TBWK1 and TBWK2) were developed based on age, sex, height, and body weight. The adjusted R2 was 0.908 for TBWK1 and 0.910 for TBWK2. The remaining 720 subjects were used for the validation of our results. Watson (TBWW) and Hume-Weyers (TBWH) formulas were also used. In men, TBWBIA showed the highest correlation with TBWH, followed by TBWK1, TBWK2 and TBWW. TBWK1 and TBWK2 showed the lower root mean square errors (RMSE) and mean prediction errors (ME) than TBWW and TBWH. On the Bland-Altman plot, the correlations between the differences and means were smaller for TBWK2 than for TBWK1. On the contrary, TBWBIA showed the highest correlation with TBWW, followed by TBWK2, TBWK1, and TBWH in females. RMSE was smallest in TBWW, followed by TBWK2, TBWK1 and TBWH. ME was closest to zero for TBWK2, followed by TBWK1, TBWW and TBWH. The correlation coefficients between the means and differences were highest in TBWW, and lowest in TBWK2. In conclusion, TBWK2 provides better accuracy with a smaller bias than the TBWW or TBWH in males. TBWK2 shows a similar accuracy, but with a smaller bias than TBWW in females

Protection of nigral dopaminergic neurons by AAV1 transduction with Rheb(S16H) against neurotoxic inflammation in vivo

We recently reported that adeno-associated virus serotype 1 (AAV1) transduction of murine nigral dopaminergic (DA) neurons with constitutively active ras homolog enriched in brain with a mutation of serine to histidine at position 16 [Rheb(S16H)] induced the production of neurotrophic factors, resulting in neuroprotective effects on the nigrostriatal DA system in animal models of Parkinson's disease (PD). To further investigate whether AAV1-Rheb(S16H) transduction has neuroprotective potential against neurotoxic inflammation, which is known to be a potential event related to PD pathogenesis, we examined the effects of Rheb(S16H) expression in nigral DA neurons under a neurotoxic inflammatory environment induced by the endogenous microglial activator prothrombin kringle-2 (pKr-2). Our observations showed that Rheb(S16H) transduction played a role in the neuroprotection of the nigrostriatal DA system against pKr-2-induced neurotoxic inflammation, even though there were similar levels of pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-alpha) and interleukin-1-beta (IL-1 beta), in the AAV1-Rheb(S16H)-treated substantia nigra (SN) compared to the SN treated with pKr-2 alone; the neuroprotective effects may be mediated by the activation of neurotrophic signaling pathways following Rheb(S16H) transduction of nigral DA neurons. We conclude that AAV1-Rheb(S16H) transduction of neuronal populations to activate the production of neurotrophic factors and intracellular neurotrophic signaling pathways may offer promise for protecting adult neurons from extracellular neurotoxic inflammation.1

Neurotrophic interactions between neurons and astrocytes following AAV1-Rheb(S16H) transduction in the hippocampus in vivo

Background and Purpose: We recently reported that AAV1-Rheb(S16H) transduction could protect hippocampal neurons through the induction of brain-derived neurotrophic factor (BDNF) in the rat hippocampus in vivo. It is still unclear how neuronal BDNF produced by AAV1-Rheb(S16H) transduction induces neuroprotective effects in the hippocampus and whether its up-regulation contributes to the enhance of a neuroprotective system in the adult brain. Experimental Approach: To determine the presence of a neuroprotective system in the hippocampus of patients with Alzheimer's disease (AD), we examined the levels of glial fibrillary acidic protein, BDNF and ciliary neurotrophic factor (CNTF) and their receptors, tropomyocin receptor kinase B (TrkB) and CNTF receptor α(CNTFRα), in the hippocampus of AD patients. We also determined whether AAV1-Rheb(S16H) transduction stimulates astroglial activation and whether reactive astrocytes contribute to neuroprotection in models of hippocampal neurotoxicity in vivo and in vitro. Key Results: AD patients may have a potential neuroprotective system, demonstrated by increased levels of full-length TrkB and CNTFRα in the hippocampus. Further AAV1-Rheb(S16H) transduction induced sustained increases in the levels of full-length TrkB and CNTFRα in reactive astrocytes and hippocampal neurons. Moreover, neuronal BDNF produced by Rheb(S16H) transduction of hippocampal neurons induced reactive astrocytes, resulting in CNTF production through the activation of astrocytic TrkB and the up-regulation of neuronal BDNF and astrocytic CNTF which had synergistic effects on the survival of hippocampal neurons in vivo. Conclusions and Implications: The results demonstrated that Rheb(S16H) transduction of hippocampal neurons could strengthen the neuroprotective system and this intensified system may have a therapeutic value against neurodegeneration in the adult brain. © 2019 The Authors. British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society1

Stroke awareness decreases prehospital delay after acute ischemic stroke in korea

BACKGROUND: Delayed arrival at hospital is one of the major obstacles in enhancing the rate of thrombolysis therapy in patients with acute ischemic stroke. Our study aimed to investigate factors associated with prehospital delay after acute ischemic stroke in Korea. METHODS: A prospective, multicenter study was conducted at 14 tertiary hospitals in Korea from March 2009 to July 2009. We interviewed 500 consecutive patients with acute ischemic stroke who arrived within 48 hours. Univariate and multivariate analyses were performed to evaluate factors influencing prehospital delay. RESULTS: Among the 500 patients (median 67 years, 62% men), the median time interval from symptom onset to arrival was 474 minutes (interquartile range, 170-1313). Early arrival within 3 hours of symptom onset was significantly associated with the following factors: high National Institutes of Health Stroke Scale (NIHSS) score, previous stroke, atrial fibrillation, use of ambulance, knowledge about thrombolysis and awareness of the patient/bystander that the initial symptom was a stroke. Multivariable logistic regression analysis indicated that awareness of the patient/bystander that the initial symptom was a stroke (OR 4.438, 95% CI 2.669-7.381), knowledge about thrombolysis (OR 2.002, 95% CI 1.104-3.633) and use of ambulance (OR 1.961, 95% CI 1.176-3.270) were significantly associated with early arrival. CONCLUSIONS: In Korea, stroke awareness not only on the part of patients, but also of bystanders, had a great impact on early arrival at hospital. To increase the rate of thrombolysis therapy and the incidence of favorable outcomes, extensive general public education including how to recognize stroke symptoms would be important.ope

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

Therapeutic Potential of AAV1-Rheb(S16H) Transduction against Neurodegenerative Diseases

Neurotrophic factors (NTFs) are essential for cell growth, survival, synaptic plasticity, and maintenance of specific neuronal population in the central nervous system. Multiple studies have demonstrated that alterations in the levels and activities of NTFs are related to the pathology and symptoms of neurodegenerative disorders, such as Parkinson’s disease (PD), Alzheimer’s disease (AD), and Huntington’s disease. Hence, the key molecule that can regulate the expression of NTFs is an important target for gene therapy coupling adeno-associated virus vector (AAV) gene. We have previously reported that the Ras homolog protein enriched in brain (Rheb)–mammalian target of rapamycin complex 1 (mTORC1) axis plays a vital role in preventing neuronal death in the brain of AD and PD patients. AAV transduction using a constitutively active form of Rheb exerts a neuroprotective effect through the upregulation of NTFs, thereby promoting the neurotrophic interaction between astrocytes and neurons in AD conditions. These findings suggest the role of Rheb as an important regulator of the regulatory system of NTFs to treat neurodegenerative diseases. In this review, we present an overview of the role of Rheb in neurodegenerative diseases and summarize the therapeutic potential of AAV serotype 1 (AAV1)-Rheb(S16H) transduction in the treatment of neurodegenerative disorders, focusing on diseases, such as AD and PD

Upregulation of Neuronal Rheb(S16H) for Hippocampal Protection in the Adult Brain

Ras homolog protein enriched in brain (Rheb) is a key activator of mammalian target of rapamycin complex 1 (mTORC1). The activation of mTORC1 by Rheb is associated with various processes such as protein synthesis, neuronal growth, differentiation, axonal regeneration, energy homeostasis, autophagy, and amino acid uptake. In addition, Rheb–mTORC1 signaling plays a crucial role in preventing the neurodegeneration of hippocampal neurons in the adult brain. Increasing evidence suggests that the constitutive activation of Rheb has beneficial effects against neurodegenerative diseases such as Alzheimer’s disease (AD) and Parkinson’s disease (PD). Our recent studies revealed that adeno-associated virus serotype 1 (AAV1) transduction with Rheb(S16H), a constitutively active form of Rheb, exhibits neuroprotective properties through the induction of various neurotrophic factors, promoting neurotrophic interactions between neurons and astrocytes in the hippocampus of the adult brain. This review provides compelling evidence for the therapeutic potential of AAV1–Rheb(S16H) transduction in the hippocampus of the adult brain by exploring its neuroprotective effects and mechanisms

Coronary Computed Tomography Angiography in Combination with Coronary Artery Calcium Scoring for the Preoperative Cardiac Evaluation of Liver Transplant Recipients

Liver transplantation is the best treatment option for early-stage hepatocellular carcinoma, liver cirrhosis, fulminant liver failure, and end-stage liver diseases. Even though advances in surgical techniques and perioperative care have improved postoperative outcomes, perioperative cardiovascular complications are a leading cause of postoperative morbidity and mortality following liver transplantation. Ischemic coronary artery disease (CAD) and cardiomyopathy are the most common cardiovascular diseases and could be negative predictors of postoperative outcomes in liver transplant recipients. Therefore, comprehensive cardiovascular evaluations are required to assess perioperative risks and prevent concomitant cardiovascular complications that would preclude good outcomes in liver transplant recipients. The two major types of cardiac computed tomography are the coronary artery calcium score (CACS) and coronary computed tomography angiography (CCTA). CCTA in combination with the CACS is a validated noninvasive alternative to coronary angiography for diagnosing and grading the severity of CAD. A CACS > 400 is associated with significant CAD and a known important predictor of posttransplant cardiovascular complications in liver transplant recipients. In this review article, we discuss the usefulness, advantages, and disadvantages of CCTA combined with CACS as a noninvasive diagnostic tool for preoperative cardiac evaluation and for maximizing the perioperative outcomes of liver transplant recipients