scholarly journals AAV-mediated inhibition of ULK1 promotes axonal regeneration in the central nervous system in vitro and in vivo

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Vinicius Toledo Ribas ◽  
Björn Friedhelm Vahsen ◽  
Lars Tatenhorst ◽  
Veronica Estrada ◽  
Vivian Dambeck ◽  
...  

AbstractAxonal damage is an early step in traumatic and neurodegenerative disorders of the central nervous system (CNS). Damaged axons are not able to regenerate sufficiently in the adult mammalian CNS, leading to permanent neurological deficits. Recently, we showed that inhibition of the autophagic protein ULK1 promotes neuroprotection in different models of neurodegeneration. Moreover, we demonstrated previously that axonal protection improves regeneration of lesioned axons. However, whether axonal protection mediated by ULK1 inhibition could also improve axonal regeneration is unknown. Here, we used an adeno-associated viral (AAV) vector to express a dominant-negative form of ULK1 (AAV.ULK1.DN) and investigated its effects on axonal regeneration in the CNS. We show that AAV.ULK1.DN fosters axonal regeneration and enhances neurite outgrowth in vitro. In addition, AAV.ULK1.DN increases neuronal survival and enhances axonal regeneration after optic nerve lesion, and promotes long-term axonal protection after spinal cord injury (SCI) in vivo. Interestingly, AAV.ULK1.DN also increases serotonergic and dopaminergic axon sprouting after SCI. Mechanistically, AAV.ULK1.DN leads to increased ERK1 activation and reduced expression of RhoA and ROCK2. Our findings outline ULK1 as a key regulator of axonal degeneration and regeneration, and define ULK1 as a promising target to promote neuroprotection and regeneration in the CNS.

2016 ◽  
Author(s):  
◽  
Christopher M. Owens

Injuries to nerves vary in their consequences, from weakened sensation and motor function to partial or complete paralysis. In the latter case, affecting about twenty thousand Americans yearly, the injury is debilitating and results in a significant decrease in quality of life. Currently there is no effective treatment for damage to the central nervous system, in particular the spinal cord. Compared to the injuries to the central nervous system, damage in the peripheral nerves, is more common, with about sixty thousand occurrences annually. The cost of associated surgical procedures and due to loss of function is in the billions. In this thesis we present work towards the construction and testing of a fully cellular, patented nerve graft, one amongst the first of its kind. For the fabrication of the graft we are the first to employ bioprinting (either implemented through a special purpose 3D bioprinter or manually), a novel tissue engineering method rapidly gaining acceptance and utility. We first review the status of bioprinting. We then detail the fabrication process. Next we report on the testing of the graft in an in vivo animal model through electrophysiology and histology. This is followed by the introduction of a novel in vitro model, aimed at providing a fast, inexpensive and reliable method to test engineered nerve grafts. We describe our work on the optimization of the in vitro assay and then the testing of the graft using the optimized assay. We conclude with a summary of our accomplishments and make suggestions for some exciting future applications of our approach.


RSC Advances ◽  
2020 ◽  
Vol 10 (32) ◽  
pp. 18677-18686
Author(s):  
Jia Liu ◽  
Kai Li ◽  
Ke Huang ◽  
Chengliang Yang ◽  
Zhipeng Huang ◽  
...  

Spinal cord injury (SCI) is a traumatic injury to the central nervous system (CNS) with a high rate of disability and a low capability of self-recovery.


1975 ◽  
Vol 228 (5) ◽  
pp. 1510-1518 ◽  
Author(s):  
R Spector ◽  
AV Lorenzo

Free myo-inositol (inositol) transport into the cerebrospinal fluid (CSF), brain, and choroid plexus and out of the cerebrospinal fluid was measured in rabbits. In vivo, inositol transport from blood into choroid plexus, CSF, and brain was saturable with an apparent affinity constant (K-t) of approximately 0.1 mM. The relative turnover of free inositol in choroid plexus (16 percent/h) was higher than in CSF 4percent/h) and brain (0.3percent/h) when meausred by tissue penetration of tracer [3-H]-labeled inositol injected into blood. However, the passage of tracer inositol was not greater than the passage of mannitol into brain when measured 15 s after a rapid injection of inositol and mannitol into the left common carotid artery. From the CSF, the clearance of inositol relative to inulin was saturable after the intraventricular injection of various concentrations of inositol and inulin. Moreover, a portion of the inositol cleared from the CSF entered brain by a saturable mechanism. In vitro, choroid plexuses, isolated from rabbits and incubated in artificial CSF, accumulated [3-H-labeled myo-inositol against a concentration gradient by a specific, active, saturable process with a K-t of 0.2 mM inositol. These results were interpreted as showing that the entry of inositol into the central nervous system from blood is regulated by a saturable transport system, and that the locus of this system may be, in part, in the choroid plexus.


2020 ◽  
Vol 17 (3) ◽  
pp. 1142-1152 ◽  
Author(s):  
Karl E. Carlström ◽  
Praveen K. Chinthakindi ◽  
Belén Espinosa ◽  
Faiez Al Nimer ◽  
Elias S. J. Arnér ◽  
...  

Abstract The Nrf2 transcription factor is a key regulator of redox reactions and considered the main target for the multiple sclerosis (MS) drug dimethyl fumarate (DMF). However, exploration of additional Nrf2-activating compounds is motivated, since DMF displays significant off-target effects and has a relatively poor penetrance to the central nervous system (CNS). We de novo synthesized eight vinyl sulfone and sulfoximine compounds (CH-1–CH-8) and evaluated their capacity to activate the transcription factors Nrf2, NFκB, and HIF1 in comparison with DMF using the pTRAF platform. The novel sulfoximine CH-3 was the most promising candidate and selected for further comparison in vivo and later an experimental model for traumatic brain injury (TBI). CH-3 and DMF displayed comparable capacity to activate Nrf2 and downstream transcripts in vitro, but with less off-target effects on HIF1 from CH-3. This was verified in cultured microglia and oligodendrocytes (OLs) and subsequently in vivo in rats. Following TBI, DMF lowered the number of leukocytes in blood and also decreased axonal degeneration. CH-3 preserved or increased the number of pre-myelinating OL. While both CH-3 and DMF activated Nrf2, CH-3 showed less off-target effects and displayed more selective OL associated effects. Further studies with Nrf2-acting compounds are promising candidates to explore potential myelin protective or regenerative effects in demyelinating disorders.


2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Ilse Bollaerts ◽  
Jessie Van houcke ◽  
Lien Andries ◽  
Lies De Groef ◽  
Lieve Moons

Damage to the central nervous system (CNS) is one of the leading causes of morbidity and mortality in elderly, as repair after lesions or neurodegenerative disease usually fails because of the limited capacity of CNS regeneration. The causes underlying this limited regenerative potential are multifactorial, but one critical aspect is neuroinflammation. Although classically considered as harmful, it is now becoming increasingly clear that inflammation can also promote regeneration, if the appropriate context is provided. Here, we review the current knowledge on how acute inflammation is intertwined with axonal regeneration, an important component of CNS repair. After optic nerve or spinal cord injury, inflammatory stimulation and/or modification greatly improve the regenerative outcome in rodents. Moreover, the hypothesis of a beneficial role of inflammation is further supported by evidence from adult zebrafish, which possess the remarkable capability to repair CNS lesions and even restore functionality. Lastly, we shed light on the impact of aging processes on the regenerative capacity in the CNS of mammals and zebrafish. As aging not only affects the CNS, but also the immune system, the regeneration potential is expected to further decline in aged individuals, an element that should definitely be considered in the search for novel therapeutic strategies.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1542
Author(s):  
Felix Neumaier ◽  
Boris D. Zlatopolskiy ◽  
Bernd Neumaier

Delivery of most drugs into the central nervous system (CNS) is restricted by the blood–brain barrier (BBB), which remains a significant bottleneck for development of novel CNS-targeted therapeutics or molecular tracers for neuroimaging. Consistent failure to reliably predict drug efficiency based on single measures for the rate or extent of brain penetration has led to the emergence of a more holistic framework that integrates data from various in vivo, in situ and in vitro assays to obtain a comprehensive description of drug delivery to and distribution within the brain. Coupled with ongoing development of suitable in vitro BBB models, this integrated approach promises to reduce the incidence of costly late-stage failures in CNS drug development, and could help to overcome some of the technical, economic and ethical issues associated with in vivo studies in animal models. Here, we provide an overview of BBB structure and function in vivo, and a summary of the pharmacokinetic parameters that can be used to determine and predict the rate and extent of drug penetration into the brain. We also review different in vitro models with regard to their inherent shortcomings and potential usefulness for development of fast-acting drugs or neurotracers labeled with short-lived radionuclides. In this regard, a special focus has been set on those systems that are sufficiently well established to be used in laboratories without significant bioengineering expertise.


2018 ◽  
Vol 47 (2) ◽  
pp. 842-850 ◽  
Author(s):  
Bo Hu ◽  
Guangtao Xu ◽  
Xiaomin Zhang ◽  
Long Xu ◽  
Hong Zhou ◽  
...  

Background/Aims: Paeoniflorin (PF) is known to have anti-inflammatory and paregoric effects, but the mechanism underlying its analgesic effect remains unclear. The aim of this study was to clarify the effect of PF on Freund’s complete adjuvant (CFA)-induced inflammatory pain and explore the underlying molecular mechanism. Methods: An inflammatory pain model was established by intraplantar injection of CFA in C57BL/6J mice. After intrathecal injection of PF daily for 8 consecutive days, thermal and mechanical withdrawal thresholds, the levels of inflammatory factors TNF-α, IL-1β and IL-6, microglial activity, and the expression of Akt-NF-κB signaling pathway in the spinal cord tissue were detected by animal ethological test, cell culture, enzyme-linked immunosorbent assay, immunofluorescence histochemistry, and western blot. Results: PF inhibited the spinal microglial activation in the CFA-induced pain model. The production of proinflammatory cytokines was decreased in the central nervous system after PF treatment both in vivo and in vitro. PF further displayed a remarkable effect on inhibiting the activation of Akt-NF-κB signaling pathway in vivo and in vitro. Conclusion: These results suggest that PF is a potential therapeutic agent for inflammatory pain and merits further investigation.


1983 ◽  
Vol 244 (4) ◽  
pp. R487-R491
Author(s):  
B. R. Walker

Both in vitro and in vivo experiments suggest that prostaglandins may affect antidiuretic hormone (ADH) release centrally. In addition, other studies show that prostaglandins administered peripherally may cause ADH release. However, these latter studies have been flawed by hemodynamic alterations and the use of anesthetics, which make interpretation difficult. The present study was designed to test for involvement of prostaglandins produced outside the central nervous system in ADH release in conscious dogs. Administration of meclofenamate (2 mg/kg and 2 mg X kg-1 X h 1, iv) resulted in a consistent fall in plasma ADH levels in five dogs. This diminution of ADH release occurred with no change in systemic hemodynamics, arterial blood gases, or plasma osmolality, suggesting that prostaglandins are important mediators of basal ADH release in the conscious dog. Because meclofenamate does not cross the blood-brain barrier, prostaglandins produced outside the central nervous system appear to be involved in this process. The specific prostaglandin involved or the site of action of prostaglandins on ADH release is not clear at this time.


Sign in / Sign up

Export Citation Format

Share Document