scholarly journals Blood vessels guide Schwann cell migration in the adult demyelinated CNS through Eph/ephrin signaling

2018 ◽  
Author(s):  
Beatriz Garcia-Diaz ◽  
Corinne Bachelin ◽  
Fanny Coulpier ◽  
Gaspard Gerschenfeld ◽  
Cyrille Deboux ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Blood Vessel ◽  
Ex Vivo ◽  
Migration Route ◽  
Eph Receptors ◽  
The Central Nervous System ◽  
Vessel Network ◽  
First Time

ABSTRACTSchwann cells (SC) enter the central nervous system (CNS) in pathophysiological conditions. However, how SC invade the CNS to remyelinate central axons remains undetermined. We studied SC migratory behaviorex vivoandin vivoafter exogenous transplantation in the demyelinated spinal cord. Data highlight for the first time that SC migrate preferentially along blood vessel in perivascular ECM, avoiding CNS myelin. We demonstratein vitroandin vivothat this migration route occurs by virtue of a dual mode of action of Eph/ephrin receptor. Indeed, EphrinB3, enriched in myelin, interacts with SC Eph receptors, to drive SC away from CNS myelin, and triggers their preferential adhesion to ECM components, such as fibronectin via integrinβ1 interactions. This complex interplay enhances SC migration along the blood vessel network and together with lesion-induced vascular remodeling facilitates their timely invasion of the lesion site. These novel findings elucidate the mechanism by which SC invade and contribute to spinal cord repair.

Abstract P283: Parkin Mediates Mitophagy in Cardioprotection

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Allen M Andres ◽  
Chengqun Huang ◽  
Eric P Ratliff ◽  
Genaro Hernandez ◽  
Pamela Lee ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Wild Type ◽  
Simulated Ischemia ◽  
Selective Targeting ◽  
Cardioprotective Effects ◽  
Mitochondrial Turnover ◽  
First Time

Autophagy-dependent mitochondrial turnover in response to cellular stress is necessary for maintaining cellular homeostasis. However, the mechanisms that govern the selective targeting of damaged mitochondria are poorly understood. Parkin, an E3 ubiquitin ligase, has been shown to be essential for the selective clearance of damaged mitochondria. Parkin is expressed in the heart, yet its function has not been investigated in the context of cardioprotection. We previously reported that autophagy is required for cardioprotection by ischemic preconditioning (IPC). In the present study, we used simulated ischemia in vitro and IPC in hearts (in vivo and ex vivo) to investigate the role of Parkin in mediating cardioprotection. In HL-1 cells, simulated ischemia induced Parkin translocation to mitochondria and mitochondrial elimination. Mitochondrial loss was blunted in Atg5-deficient cells, revealing the requirement for autophagy in mitochondrial elimination. Consistent with previous reports implicating p62/SQSTM1 in mitophagy, we found that downregulation of p62 attenuated mitophagy and exacerbated cell death in HL-1 cardiomyocytes subjected to simulated ischemia. While wild type mice showed p62 translocation to mitochondria after IPC, Parkin knockout mice exhibited attenuated translocation of p62 to mitochondria. Importantly, ablation of Parkin in mice abolished the cardioprotective effects of IPC. These results reveal for the first time the crucial role of Parkin and mitophagy in cardioprotection.

scholarly journals Biomaterial Approaches to Modulate Reactive Astroglial Response

2018 ◽  
Vol 205 (5-6) ◽  
pp. 372-395 ◽  
Author(s):  
Jonathan M. Zuidema ◽  
Ryan J. Gilbert ◽  
Manoj K. Gottipati
Keyword(s):  
Spinal Cord ◽  
Glial Scar ◽  
Secondary Injury ◽  
Injury Site ◽  
Beneficial Effects ◽  
Cord Injury ◽  
The Central Nervous System ◽  
Preclinical Animal Models

Over several decades, biomaterial scientists have developed materials to spur axonal regeneration and limit secondary injury and tested these materials within preclinical animal models. Rarely, though, are astrocytes examined comprehensively when biomaterials are placed into the injury site. Astrocytes support neuronal function in the central nervous system. Following an injury, astrocytes undergo reactive gliosis and create a glial scar. The astrocytic glial scar forms a dense barrier which restricts the extension of regenerating axons through the injury site. However, there are several beneficial effects of the glial scar, including helping to reform the blood-brain barrier, limiting the extent of secondary injury, and supporting the health of regenerating axons near the injury site. This review provides a brief introduction to the role of astrocytes in the spinal cord, discusses astrocyte phenotypic changes that occur following injury, and highlights studies that explored astrocyte changes in response to biomaterials tested within in vitro or in vivo environments. Overall, we suggest that in order to improve biomaterial designs for spinal cord injury applications, investigators should more thoroughly consider the astrocyte response to such designs.

scholarly journals Candida albicans forms biofilms on the vaginal mucosa

Microbiology ◽  
2010 ◽  
Vol 156 (12) ◽  
pp. 3635-3644 ◽  
Author(s):  
M. M. Harriott ◽  
E. A. Lilly ◽  
T. E. Rodriguez ◽  
P. L. Fidel ◽  
M. C. Noverr
Keyword(s):  
Biofilm Formation ◽  
Ex Vivo ◽  
Microscopic Analysis ◽  
Vaginal Mucosa ◽  
First Time ◽  
Established Role ◽  
Type Strains

Current understanding of resistance and susceptibility to vulvovaginal candidiasis challenges existing paradigms of host defence against fungal infection. While abiotic biofilm formation has a clearly established role during systemic Candida infections, it is not known whether C. albicans forms biofilms on the vaginal mucosa and the possible role of biofilms in disease. In vivo and ex vivo murine vaginitis models were employed to examine biofilm formation by scanning electron and confocal microscopy. C. albicans strains included 3153A (lab strain), DAY185 (parental control strain), and mutants defective in morphogenesis and/or biofilm formation in vitro (efg1/efg1 and bcr1/bcr1). Both 3153A and DAY815 formed biofilms on the vaginal mucosa in vivo and ex vivo as indicated by high fungal burden and microscopic analysis demonstrating typical biofilm architecture and presence of extracellular matrix (ECM) co-localized with the presence of fungi. In contrast, efg1/efg1 and bcr1/bcr1 mutant strains exhibited weak or no biofilm formation/ECM production in both models compared to wild-type strains and complemented mutants despite comparable colonization levels. These data show for the first time that C. albicans forms biofilms in vivo on vaginal epithelium, and that in vivo biotic biofilm formation requires regulators of biofilm formation (BCR1) and morphogenesis (EFG1).

scholarly journals Image-based modelling of skeletal muscle oxygenation

2017 ◽  
Vol 14 (127) ◽  
pp. 20160992 ◽  
Author(s):  
B. Zeller-Plumhoff ◽  
T. Roose ◽  
G. F. Clough ◽  
P. Schneider
Keyword(s):  
Skeletal Muscle ◽  
Blood Vessel ◽  
Ex Vivo ◽  
Imaging Techniques ◽  
Muscle Oxygenation ◽  
Skeletal Muscle Oxygenation ◽  
Health And Disease ◽  
Vessel Networks

The supply of oxygen in sufficient quantity is vital for the correct functioning of all organs in the human body, in particular for skeletal muscle during exercise. Disease is often associated with both an inhibition of the microvascular supply capability and is thought to relate to changes in the structure of blood vessel networks. Different methods exist to investigate the influence of the microvascular structure on tissue oxygenation, varying over a range of application areas, i.e. biological in vivo and in vitro experiments, imaging and mathematical modelling. Ideally, all of these methods should be combined within the same framework in order to fully understand the processes involved. This review discusses the mathematical models of skeletal muscle oxygenation currently available that are based upon images taken of the muscle microvasculature in vivo and ex vivo . Imaging systems suitable for capturing the blood vessel networks are discussed and respective contrasting methods presented. The review further informs the association between anatomical characteristics in health and disease. With this review we give the reader a tool to understand and establish the workflow of developing an image-based model of skeletal muscle oxygenation. Finally, we give an outlook for improvements needed for measurements and imaging techniques to adequately investigate the microvascular capability for oxygen exchange.

scholarly journals Dynamic CCN3 expression in the murine CNS does not confer essential roles in myelination or remyelination

2020 ◽  
Vol 117 (30) ◽  
pp. 18018-18028
Author(s):  
Nira de la Vega Gallardo ◽  
Rosana Penalva ◽  
Marie Dittmer ◽  
Michelle Naughton ◽  
John Falconer ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Ex Vivo ◽  
Matricellular Protein ◽  
Suprachiasmatic Nuclei ◽  
Dynamic Expression ◽  
Ccn3 Expression ◽  
Cns Myelination

CCN3 is a matricellular protein that promotes oligodendrocyte progenitor cell differentiation and myelination in vitro and ex vivo. CCN3 is therefore a candidate of interest in central nervous system (CNS) myelination and remyelination, and we sought to investigate the expression and role of CCN3 during these processes. We found CCN3 to be expressed predominantly by neurons in distinct areas of the CNS, primarily the cerebral cortex, hippocampus, amygdala, suprachiasmatic nuclei, anterior olfactory nuclei, and spinal cord gray matter. CCN3 was transiently up-regulated following demyelination in the brain of cuprizone-fed mice and spinal cord lesions of mice injected with lysolecithin. However, CCN3−/−mice did not exhibit significantly different numbers of oligodendroglia or differentiated oligodendrocytes in the healthy or remyelinating CNS, compared to WT controls. These results suggest that despite robust and dynamic expression in the CNS, CCN3 is not required for efficient myelination or remyelination in the murine CNS in vivo.

Robot-assisted endoscopic exploration of the spinal cord

2010 ◽  
Vol 224 (7) ◽  
pp. 1515-1529 ◽  
Author(s):  
L Ascari ◽  
C Stefanini ◽  
U Bertocchi ◽  
P Dario
Keyword(s):  
Spinal Cord ◽  
Subarachnoid Space ◽  
Ex Vivo ◽  
Hierarchical Control ◽  
Three Dimensional ◽  
Robot Assisted ◽  
Actuation System ◽  
Spinal Subarachnoid Space

This work presents the design and development of an integrated image-guided robot-assisted endoscopic system for the safe navigation within the spinal subarachnoid space, providing the surgeon with the direct vision of the structures (i.e. spinal cord, roots, vessels) and the possibility of performing some particularly useful operations, like local electrostimulation of nerve roots. The modelling, micro-fabrication, fluidic sustentation, and cable-based actuation system of a steerable tip for a multilumen flexible catheter is described; the hierarchical control system shared between the surgeon and the computer, and based on machine vision techniques and a simple but effective three-dimensional reconstruction is detailed. The Blind Expected Perception sensory-motor scheme is proposed in robot-assited endoscopy. Results from in vitro, ex vivo, and in vivo experiments show that the described model can accurately predict the shape of the catheter given the tension distribution on the cables, that the proposed actuation system can assure smooth and precise control of the catheter tip, that the fluidic sustentation of the catheter is essential in in vivo navigation, and that the proposed rear view mirror interface to show non-visible obstacles is appropriate; in conclusion, the results proved the validity of the proposed solution to develop an intrinsically safe robotic system for navigation and intervention in a narrow and challenging environment such as the spinal subarachnoid space.

scholarly journals Astrovirus-Induced Synthesis of Nitric Oxide Contributes to Virus Control during Infection

2004 ◽  
Vol 78 (3) ◽  
pp. 1564-1574 ◽  
Author(s):  
Matthew D. Koci ◽  
Laura A. Kelley ◽  
Diane Larsen ◽  
Stacey Schultz-Cherry
Keyword(s):  
Nitric Oxide ◽  
Ex Vivo ◽  
Small Animal ◽  
Innate Immune Responses ◽  
Vitro Analysis ◽  
Oxide Synthase ◽  
First Time

ABSTRACT Astrovirus is one of the major causes of infant and childhood diarrhea worldwide. Our understanding of astrovirus pathogenesis trails behind our knowledge of its molecular and epidemiologic properties. Using a recently developed small-animal model, we investigated the mechanisms by which astrovirus induces diarrhea and the role of both the adaptive and innate immune responses to turkey astrovirus type-2 (TAstV-2) infection. Astrovirus-infected animals were analyzed for changes in total lymphocyte populations, alterations in CD4+/CD8+ ratios, production of virus-specific antibodies (Abs), and macrophage activation. There were no changes in the numbers of circulating or splenic lymphocytes or in CD4+/CD8+ ratios compared to controls. Additionally, there was only a modest production of virus-specific Abs. However, adherent spleen cells from infected animals produced more nitric oxide (NO) in response to ex vivo stimulation with lipopolysaccharide. In vitro analysis demonstrated that TAstV-2 induced macrophage production of inducible nitric oxide synthase. Studies using NO donors and inhibitors in vivo demonstrated, for the first time, that NO inhibited astrovirus replication. These studies suggest that NO is important in limiting astrovirus replication and are the first, to our knowledge, to describe the potential role of innate immunity in astrovirus infection.

“Open-top” microfluidic device for in vitro three-dimensional capillary beds

Lab on a Chip ◽  
2017 ◽  
Vol 17 (20) ◽  
pp. 3405-3414 ◽  
Author(s):  
Soojung Oh ◽  
Hyunryul Ryu ◽  
Dongha Tahk ◽  
Jihoon Ko ◽  
Yoojin Chung ◽  
...  
Keyword(s):  
Blood Vessel ◽  
Microfluidic Device ◽  
Three Dimensional ◽  
Vessel Network ◽  
Blood Vessel Network

We introduce a novel microfluidic device to co-culture a blood vessel network and cell tissues in an in vivo-like niche.

scholarly journals BASHY Dye Platform Enables the Fluorescence Bioimaging of Myelin Debris Phagocytosis by Microglia during Demyelination

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3163
Author(s):  
Maria V. Pinto ◽  
Fábio M. F. Santos ◽  
Catarina Barros ◽  
Ana Rita Ribeiro ◽  
Uwe Pischel ◽  
...  
Keyword(s):  
Demyelinating Disease ◽  
Ex Vivo ◽  
Nonpolar Lipid ◽  
Myelin Lipid ◽  
Myelin Debris ◽  
The Central Nervous System ◽  
Fluorescence Bioimaging ◽  
Lipid Aggregates

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system that is characterized by the presence of demyelinated regions with accumulated myelin lipid debris. Importantly, to allow effective remyelination, such debris must be cleared by microglia. Therefore, the study of microglial activity with sensitive tools is of great interest to better monitor the MS clinical course. Using a boronic acid-based (BASHY) fluorophore, specific for nonpolar lipid aggregates, we aimed to address BASHY’s ability to label nonpolar myelin debris and image myelin clearance in the context of demyelination. Demyelinated ex vivo organotypic cultures (OCSCs) and primary microglia cells were immunostained to evaluate BASHY’s co-localization with myelin debris and also to evaluate BASHY’s specificity for phagocytosing cells. Additionally, mice induced with experimental autoimmune encephalomyelitis (EAE) were injected with BASHY and posteriorly analyzed to evaluate BASHY+ microglia within demyelinated lesions. Indeed, in our in vitro and ex vivo studies, we showed a significant increase in BASHY labeling in demyelinated OCSCs, mostly co-localized with Iba1-expressing amoeboid/phagocytic microglia. Most importantly, BASHY’s presence was also found within demyelinated areas of EAE mice, essentially co-localizing with lesion-associated Iba1+ cells, evidencing BASHY’s potential for the in vivo bioimaging of myelin clearance and myelin-carrying microglia in regions of active demyelination.

scholarly journals Carnosine quenches the reactive carbonyl acrolein in the central nervous system and attenuates autoimmune neuroinflammation

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Jan Spaas ◽  
Wouter M. A. Franssen ◽  
Charly Keytsman ◽  
Laura Blancquaert ◽  
Tim Vanmierlo ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Therapeutic Effect ◽  
Inflammatory Activity ◽  
Inflammatory Lesions ◽  
The Central Nervous System ◽  
Reactive Carbonyl

Abstract Background Multiple sclerosis (MS) is a chronic autoimmune disease driven by sustained inflammation in the central nervous system. One of the pathological hallmarks of MS is extensive free radical production. However, the subsequent generation, potential pathological role, and detoxification of different lipid peroxidation-derived reactive carbonyl species during neuroinflammation are unclear, as are the therapeutic benefits of carbonyl quenchers. Here, we investigated the reactive carbonyl acrolein and (the therapeutic effect of) acrolein quenching by carnosine during neuroinflammation. Methods The abundance and localization of acrolein was investigated in inflammatory lesions of MS patients and experimental autoimmune encephalomyelitis (EAE) mice. In addition, we analysed carnosine levels and acrolein quenching by endogenous and exogenous carnosine in EAE. Finally, the therapeutic effect of exogenous carnosine was assessed in vivo (EAE) and in vitro (primary mouse microglia, macrophages, astrocytes). Results Acrolein was substantially increased in inflammatory lesions of MS patients and EAE mice. Levels of the dipeptide carnosine (β-alanyl-l-histidine), an endogenous carbonyl quencher particularly reactive towards acrolein, and the carnosine-acrolein adduct (carnosine-propanal) were ~ twofold lower within EAE spinal cord tissue. Oral carnosine treatment augmented spinal cord carnosine levels (up to > tenfold), increased carnosine-acrolein quenching, reduced acrolein-protein adduct formation, suppressed inflammatory activity, and alleviated clinical disease severity in EAE. In vivo and in vitro studies indicate that pro-inflammatory microglia/macrophages generate acrolein, which can be efficiently quenched by increasing carnosine availability, resulting in suppressed inflammatory activity. Other properties of carnosine (antioxidant, nitric oxide scavenging) may also contribute to the therapeutic effects. Conclusions Our results identify carbonyl (particularly acrolein) quenching by carnosine as a therapeutic strategy to counter inflammation and macromolecular damage in MS.

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