Neurosciences
Abstract
Glioblastoma is amongst the deadliest human cancers and is highly vascularized. Angiogenesis is very dynamic during brain development, almost quiescent in the adult brain but reactivated in vascular-dependent CNS pathologies including brain tumors. The onco-fetal axis describes the reactivation of fetal programs in tumors, but its relevance in endothelial- and perivascular cells of the human brain vasculature in glial brain tumors is unexplored. Nucleolin is a regulator of cell proliferation and angiogenesis, but its roles in the brain vasculature remain unknown. Here, we studied the expression of Nucleolin in the neurovascular unit in human fetal brains, adult brains and human gliomas in vivo and its effects on sprouting angiogenesis and endothelial metabolism in vitro. Nucleolin is highly expressed in endothelial- and perivascular cells during brain development, downregulated in the adult brain, and upregulated in glioma. Moreover, Nucleolin expression correlated with glioma malignancy in vivo. In culture, siRNA-mediated Nucleolin knock-down reduced human brain endothelial cell (HCMEC) and human umbilical vein endothelial cell (HUVEC) sprouting angiogenesis, proliferation, filopodia extension, and glucose metabolism. Furthermore, inhibition of Nucleolin with the aptamer AS1411 decreased brain endothelial cell proliferation in vitro. Mechanistically, Nucleolin knock-down in HCMECs and HUVECs uncovered regulation of angiogenesis involving VEGFR2 and of endothelial glycolysis. These findings identify Nucleolin as a neurodevelopmental factor reactivated in glioma that promotes sprouting angiogenesis and endothelial metabolism, characterizing Nucleolin as an onco-fetal protein. Our findings have potential implications in the therapeutic targeting of glioma.
Authors
Marc Schwab, Ignazio de Trizio, Moheb Ghobrial, Jau-Ye Shiu, Oguzkan Sürücü, Francesco Girolamo, Mariella Errede, Murat Yilmaz, Johannes Haybaeck, Alessandro Moiraghi, Philippe P. Monnier, Sean E. Lawler, Jeffrey P. Greenfield, Ivan Radovanovic, Karl Frei, Ralph Schlapbach, Viola Vogel, Daniela Virgintino, Katrien De Bock, Thomas Wälchli
Abstract
The need for new advances in the management/treatment options for ischemic stroke patients requires that upcoming preclinical research uses animals with more human-like brain characteristics. The porcine brain is considered appropriate although the presence of the rete mirabile (RM) prevents direct catheterization of the intracranial arteries to produce focal cerebral ischemia. To develop a reproducible minimally invasive porcine stroke model, a catheter+guide was introduced through the femoral artery until reaching the left RM. Using the pressure cooker technique (PCT), Squid-12 embolization material was deposited to fill, overflow and occlude the left RM, the left internal carotid artery (ICA) and left circle of Willis (CW) wing up to the origins of the middle cerebral arteries’ (MCAs), thus mimicking the occlusion produced in the filament model in rodents. Longitudinal multimodal cerebral MR imaging was conducted to assess the brain damage and cerebral blood supply. The technique we describe here occluded up to the origins of the MCAs in 7 out of 8 swine, inducing early damage 90 min post-occlusion that later evolved to a large cerebral infarction, and producing no mortality during the intervention. This novel minimally invasive ischemic stroke model in swine produced reproducible infarcts and shows translational features common to human stroke.
Authors
Carlos Castaño, Marc Melià-Sorolla, Alexia García-Serran, Núria DeGregorio-Rocasolano, Maria Rosa García-Sort, María Hernandez-Pérez, Adrián Valls Carbó, Osvaldo A. Pino, Jordi Grifols, Alba Iruela-Sánchez, Alicia Palomar-García, Josep Puig, Octavi Martí-Sistac, Antoni Davalos, Teresa Gasull
Abstract
The inability of mature retinal ganglion cells (RGCs) to regenerate axons after optic nerve injury can be partially reversed by manipulating cell-autonomous and/or -non-autonomous factors. Although manipulations of cell-non-autonomous factors could have higher translational potential than genetic manipulations of RGCs, they have generally produced lower levels of optic nerve regeneration. Here we report that preconditioning resulting from mild lens injury (conditioning LI, cLI) prior to optic nerve damage induces far greater regeneration than LI after nerve injury or the pro-inflammatory agent zymosan given either before or after nerve damage. Unlike zymosan-induced regeneration, cLI is unaltered by depleting mature neutrophils or T cells or blocking receptors for known inflammation-derived growth factors (Oncomodulin, SDF1, CCL5), and is only partly diminished by suppressing CCR2+ monocyte recruitment. Repeated episodes of LI lead to full-length optic nerve regeneration, and pharmacological removal of local resident macrophages with the colony stimulating factor 1 receptor (CSF1R) inhibitor PLX5622 enables some axons to re-innervate the brain in just 6 weeks, comparable to the results obtained with the most effective genetic manipulations of RGCs. Thus, cell-non-autonomous interventions can induce high levels of optic nerve regeneration, paving the way to uncover potent, translatable therapeutic targets for CNS repair.
Authors
Qian Feng, Kimberly A. Wong, Larry I. Benowitz
Abstract
BACKGROUND Chronic kidney disease (CKD) is characterized by chronic overactivation of the sympathetic nervous system (SNS), which increases the risk of cardiovascular (CV) disease and mortality. SNS overactivity increases CV risk by multiple mechanisms, including vascular stiffness. We tested the hypothesis that aerobic exercise training would reduce resting SNS activity and vascular stiffness in patients with CKD.METHODS In this randomized controlled trial, sedentary older adults with CKD underwent 12 weeks of exercise (cycling, n = 32) or stretching (an active control group, n = 26). Exercise and stretching interventions were performed 20–45 minutes/session at 3 days/week and were matched for duration. Primary endpoints include resting muscle sympathetic nerve activity (MSNA) via microneurography, arterial stiffness by central pulse wave velocity (PWV), and aortic wave reflection by augmentation index (AIx).RESULTS There was a significant group × time interaction in MSNA and AIx with no change in the exercise group but with an increase in the stretching group after 12 weeks. The magnitude of change in MSNA was inversely associated with baseline MSNA in the exercise group. There was no change in PWV in either group over the study period.CONCLUSION Our data demonstrate that 12 weeks of cycling exercise has beneficial neurovascular effects in patients with CKD. Specifically, exercise training safely and effectively ameliorated the increase in MSNA and AIx observed over time in the control group. This sympathoinhibitory effect of exercise training showed greater magnitude in patients with CKD with higher resting MSNA.TRIAL REGISTRATION ClinicalTrials.gov, NCT02947750.FUNDING NIH R01HL135183; NIH R61AT10457; NIH NCATS KL2TR002381; and NIH T32 DK00756; NIH F32HL147547; and VA Merit I01CX001065.
Authors
Jinhee Jeong, Justin D. Sprick, Dana R. DaCosta, Kevin Mammino, Joe R. Nocera, Jeanie Park
Abstract
Coagulopathy contributes to the majority of deaths and disabilities associated with traumatic brain injury (TBI). Whether neutrophil extracellular traps (NETs) contribute to an abnormal coagulation state in the acute process of TBI remains unknown. Our objectives were to demonstrate the definitive role of NETs in coagulopathy in TBI. We detected NET markers in 128 TBI patients and 34 healthy subjects. Neutrophil-platelet (PLT) aggregates were detected in blood samples from TBI patients and healthy subjects using flow cytometry and staining with CD41 and CD66b. Endothelial cells (ECs) were incubated with isolate NETs and detected the expression of vascular endothelial (VE)-cadherin, syncanden-1, thrombomodulin, von Willebrand factor (VWF), phosphatidylserine (PS) and and tissue factor (TF). In addition, we established a TBI mouse model to detect the potential role of NETs in TBI associated coagulopathy. NETs generation was mediated by High Mobility Group Box 1(HMGB1) from activated platelets and contribute to procoagulant activity in TBI. Furthermore, coculture experiments indicated that NETs damaged the endothelial barrier and caused these cells to assume a procoagulant phenotype. Moreover, the administration of DNase I before or after brain trauma markedly reduced coagulopathy and improved the survival and clinical outcome of mice with TBI.
Authors
Jiaqi Jin, Fang Wang, Jiawei Tian, Xinyi Zhao, Jiawei Dong, Nan Wang, Zhihui Liu, Hontao Zhao, Wenqiang Li, Ge Mang, Shaoshan Hu
Abstract
BACKGROUND. Major depressive disorder (MDD) can benefit from novel interventions and personalization. Deep transcranial magnetic stimulation (Deep TMS) targeting the lateral prefrontal cortex (LPFC) using the H1 Coil, was FDA-cleared for treatment of MDD, however recent preliminary data indicate that targeting medial prefrontal cortex (MPFC) using the H7 Coil might induce as good or even better outcomes. Here we explored whether Deep TMS targeting the MPFC is non-inferior to targeting LPFC, and whether electrophysiological or clinical markers for patient selection can be identified. METHODS. The present prospective multicenter randomized study enrolled 169 MDD patients who failed antidepressant treatments in the current episode. Patients were randomized to receive 24 Deep TMS sessions over 6 weeks, using either the H1 Coil or the H7 Coil. The primary efficacy endpoint was the change from baseline to week 6 in the Hamilton-Depression-Rating-Scores. RESULTS. Clinical efficacy and safety profiles were similar and not significantly different between groups, with response rates of 60.9% for the H1 Coil and 64.2% for the H7 Coil. Moreover, brain activity measured by EEG during the first treatment session correlated with clinical outcomes in a coil-specific manner, and a cluster of baseline clinical symptoms was found to potentially distinguish between patients who can benefit from each Deep TMS target. CONCLUSION. This study provides a new treatment option for MDD, using the H7 Coil, and initial guidance to differentiate between patients likely to respond to LPFC versus MPFC stimulation targets, which require further validation studies. TRIAL REGISTRATION. ClinicalTrials.gov NCT03012724. FUNDING. Brainsway Ltd.
Authors
Abraham Zangen, Samuel Zibman, Aron Tendler, Noam Barnea-Ygael, Uri Alyagon, Daniel M. Blumberger, Geoffrey Grammer, Hadar Shalev, Tatiana Gulevsky, Tanya Vapnik, Alexander Bystritsky, Igor Filipčić, David Feifel, Ahava Stein, Frederic Deutsch, Yiftach Roth, Mark S. George
Abstract
Neuromyelitis optica spectrum disorders (NMOSD) are inflammatory autoimmune disorders of the CNS. Immunoglobulin G autoantibodies targeting the aquaporin-4 water channel (AQP4-IgG) are the pathogenic effector of NMOSD. Dysregulated T follicular helper (Tfh) cells have been implicated in the loss of B-cell tolerance in autoimmune diseases. The contribution of Tfh cells to disease activity and the therapeutic potential of targeting these cells in NMOSD remain unclear. Here, we established an autoimmune model of NMOSD by immunizing mice against AQP4 via in vivo electroporation. After AQP4 immunization, mice displayed AQP4 autoantibodies in the blood circulation, blood-brain barrier disruption, and IgG infiltration in the spinal cord parenchyma. Moreover, AQP4 immunization induced motor impairments and NMOSD-like pathologies including astrocytopathy, demyelination, axonal loss, and microglia activation. These were associated with increased splenic Tfh, T helper 1 (Th1) and T helper 17 (Th17) cells, memory B cells and plasma cell. AQP4-deficient mice did not displayed motor impairments and NMOSD-like pathologies after AQP4 immunization. Importantly, abrogating inducible costimulator (ICOS)/inducible costimulator ligand (ICOS-L) signalling using anti-ICOS-L antibody depleted Tfh cells and suppressed the response of Th1 and Th17 cells, memory B cells, and plasma cells in AQP4-immunized mice. These findings were associated with ameliorated motor impairments and spinal cord pathologies. This study suggests a role of Tfh cells in the pathophysiology of NMOSD in a novel mouse model with AQP4 autoimmunity. It also provides an animal model for further investigating the immunological mechanisms underlying AQP4 autoimmunity, and for developing novel therapeutic interventions targeting the autoimmune reactions in NMOSD.
Authors
Leung-Wah Yick, Oscar Ka-Fai Ma, Ethel Yin-Ying Chan, Krystal Xiwing Yau, Jason Shing-Cheong Kwan, Koon-Ho Chan
Abstract
The molecular mediators of cell death and inflammation in Alzheimer’s disease (AD) have yet to be fully elucidated. Caspase-8 is a critical regulator of several cell death and inflammatory pathways; however, its role in AD pathogenesis has not yet been examined in detail. In the absence of Caspase-8, mice are embryonic lethal due to excessive RIPK3-dependent necroptosis. Compound RIPK3 and Caspase-8 mutants rescue embryonic lethality, which we leveraged to examine the roles of these pathways in an amyloid beta (Aβ)-mediated mouse model of AD. We find that combined deletion of Caspase-8 and RIPK3, but not RIPK3 alone, leads to diminished Aβ deposition and microgliosis in the 5xFAD mouse model of AD. Despite its well-known role in cell death, Caspase-8 does not appear to impact cell loss in the 5xFAD model. In contrast, we found that Caspase-8 is a critical regulator of Aβ-driven inflammasome gene expression and IL-1β release. Interestingly, loss of RIPK3 had only a modest effect on disease progression suggesting that inhibition of necroptosis or RIPK3-mediated cytokine pathways are not critical during mid stages of Aβ amyloidosis. These findings suggest that therapeutics targeting Caspase-8 may represent a novel strategy to limit Aꞵ amyloidosis and neuroinflammation in AD.
Authors
Sushanth Kumar, Sakar Budhathoki, Christopher B. Oliveira, August D. Kahle, O. Yipkin Calhan, John R. Lukens, Christopher D. Deppmann
Abstract
Pathogenic SOX2 variants typically cause severe ocular defects within a SOX2-disorder spectrum that includes hypogonadotropic hypogonadism (HH). We examined exome sequencing data from a large, well-phenotyped cohort of patients (n=1453) with Idiopathic Hypogonadotropic Hypogonadism (IHH) for pathogenic SOX2 variants to investigate the underlying pathogenic SOX2 spectrum and its associated phenotypes. We identified eight IHH individuals harboring heterozygous pathogenic SOX2 variants with variable ocular phenotypes. These variant proteins were tested in vitro to determine whether a causal relationship between IHH and SOX2 exists. We found that Sox2 is highly expressed in the hypothalamus of adult mice and colocalizes with KISS1 expression in the anteroventral periventricular nucleus of adult female mice. In vitro, shRNA suppression of mouse SOX2 protein in Kiss-expressing cell lines increases the levels of human kisspeptin luciferase transcription (hKISS-luc), while SOX2 overexpression represses hKiss-luc transcription. Further, four of the identified SOX2 variants prevented this SOX2-mediated repression of hKiss-luc. Together these data suggest that pathogenic SOX2 variants contribute to both anosmic and normosmic forms of IHH attesting to hypothalamic defects in the SOX2-disorder spectrum. Our study describes novel mechanisms contributing to SOX2-related disease and highlights the necessity of SOX2 screening in IHH genetic evaluation irrespective of associated ocular defects.
Authors
Jessica Cassin, Maria I. Stamou, Kimberly W. Keefe, Kaitlin Sung, Celine Bojo, Karen J. Tonsfeldt, Rebecca A. Rojas, Vanessa Ferreira Lopes, Lacey Plummer, Kathryn B. Salnikov, David L. Keefe Jr., Metin Ozata, Myron Genel, Neoklis A. Georgopoulos, Janet E. Hall, William F. Crowley Jr., Stephanie B. Seminara, Pamela L. Mellon, Ravikumar Balasubramanian
Abstract
It is suggested that activation of receptor for advanced glycation end products (RAGE) induces proinflammatory response in diabetic nerve tissues. Macrophage infiltration is invoked in the pathogenesis of diabetic polyneuropathy (DPN), while the association between macrophage and RAGE activation and the downstream effects of macrophages remain to be fully clarified in DPN. This study explored the role of RAGE in the pathogenesis of DPN through the modified macrophages. Infiltrating proinflammatory macrophages impaired insulin sensitivity, atrophied the neurons in dorsal root ganglion, and slowed retrograde axonal transport (RAT) in the sciatic nerve of type 1 diabetic mice. RAGE-null mice showed an increase in the population of antiinflammatory macrophages, accompanied by intact insulin sensitivity, normalized ganglion cells, and RAT. BM transplantation from RAGE-null mice to diabetic mice protected the peripheral nerve deficits, suggesting that RAGE is a major determinant for the polarity of macrophages in DPN. In vitro coculture analyses revealed proinflammatory macrophage–elicited insulin resistance in the primary neuronal cells isolated from dorsal root ganglia. Applying time-lapse recording disclosed a direct impact of proinflammatory macrophage and insulin resistance on the RAT deficits in primary neuronal cultures. These results provide a potentially novel insight into the development of RAGE-related DPN.
Authors
Sho Osonoi, Hiroki Mizukami, Yuki Takeuchi, Hikari Sugawa, Saori Ogasawara, Shizuka Takaku, Takanori Sasaki, Kazuhiro Kudoh, Koichi Ito, Kazunori Sango, Ryoji Nagai, Yasuhiko Yamamoto, Makoto Daimon, Hiroshi Yamamoto, Soroku Yagihashi
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