Potential neurotoxicity of a novel aminoacridine analogue

1995 ◽  
Vol 14 (6) ◽  
pp. 469-474 ◽  
Author(s):  
TM Walker ◽  
B. Starr ◽  
BB Dewhurst ◽  
C. Atterwill

1 A class of compounds, 9-aminoacridines, have long been known to be reversible inhibitors of acetyl cholinesterase (AChE - EC 3.1.1.7), the most familiar of which is 9-amino-1,2,3,4-tetrahydroacridine (Tacrine). 2 A novel aminoacridine was synthesised: - 2-tertiary butyl-9-amino-1,2,3,4-tetrahydroacridine (2tBuTHA). 3 In vitro comparisons of the acetylcholinesterase inhibitory potential and neurotoxicity compared to Tacrine were performed using a chemically differentiated neuroblastoma cell line (Neuro 2A). 2tBuTHA, but not Tacrine, was cytotoxic to the neural cell following 20 h exposure, despite being the least potent AChE inhibitor (IC80 AChE 12.53 μM +/- 1.14 s.e.m., Neutral Red Uptake IC50 9.53 μM +/- 0.98 s.e.m., MTT Reduction IC80 14.6 μM +/- 1.43 s.e.m.). 4 In vivo studies used a novel application of a five arm radial maze to assess neuropharmacological effects on working memory in control and Scopolamine (1 mg kg-1 i.p.) treated mice. There was an impairment of short term cognitive function with 2tBuTHA (15 mg kg -1 i.p.), but not Tacrine (10 mg kg-1 i.p.) which improved the Scopolamine deficit as expected. 5 This combined in vitro and in vivo data infers a neuro toxic property for the novel compound 2tBuTHA, a close structural analogue of Tacrine.

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3495
Author(s):  
Adriana Trapani ◽  
Filomena Corbo ◽  
Gennaro Agrimi ◽  
Nicoletta Ditaranto ◽  
Nicola Cioffi ◽  
...  

Background: The blood–brain barrier (BBB) bypass of dopamine (DA) is still a challenge for supplying it to the neurons of Substantia Nigra mainly affected by Parkinson disease. DA prodrugs have been studied to cross the BBB, overcoming the limitations of DA hydrophilicity. Therefore, the aim of this work is the synthesis and preliminary characterization of an oxidized alginate-dopamine (AlgOX-DA) conjugate conceived for DA nose-to-brain delivery. Methods: A Schiff base was designed to connect oxidized polymeric backbone to DA and both AlgOX and AlgOX-DA were characterized in terms of Raman, XPS, FT-IR, and 1H- NMR spectroscopies, as well as in vitro mucoadhesive and release tests. Results: Data demonstrated that AlgOX-DA was the most mucoadhesive material among the tested ones and it released the neurotransmitter in simulated nasal fluid and in low amounts in phosphate buffer saline. Results also demonstrated the capability of scanning near-field optical microscopy to study the structural and fluorescence properties of AlgOX, fluorescently labeled with fluorescein isothiocyanate microstructures. Interestingly, in SH-SY5Y neuroblastoma cell line up to 100 μg/mL, no toxic effect was derived from AlgOX and AlgOX-DA in 24 h. Conclusions: Overall, the in vitro performances of AlgOX and AlgOX-DA conjugates seem to encourage further ex vivo and in vivo studies in view of nose-to-brain administration.


2005 ◽  
Vol 3 (3) ◽  
pp. 514-521 ◽  
Author(s):  
E. PERZBORN ◽  
J. STRASSBURGER ◽  
A. WILMEN ◽  
J. POHLMANN ◽  
S. ROEHRIG ◽  
...  

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258420
Author(s):  
Ryohei Tanaka-Kanegae ◽  
Koichiro Hamada

Background Cholinergic neurons utilize choline (Ch) to synthetize acetylcholine (ACh) and contain a high-affinity Ch transporter, Ch acetyltransferase (ChAT), ACh receptors, and acetylcholinesterase (AChE). As the depletion or malfunction of each component of the cholinergic system has been reported in patients with dementia, many studies have sought to evaluate whether treatment candidates affect each of the cholinergic components. The associated changes in the cholinergic components may be reflected by intra- or extra-cellular ACh levels, with an increase in extracellular ACh levels occurring following AChE inhibition. We hypothesized that increases in intracellular ACh levels can be more sensitively detected than those in extracellular ACh levels, thereby capturing subtle effects in the cholinergic components other than AChE. The objective of this study was to test this hypothesis. Methods We developed an in vitro model to measure both extracellular and intracellular ACh levels using the human cholinergic neuroblastoma cell line, LA-N-2, which have been reported to express Ch transporter, ChAT, muscarinic ACh receptor (mAChR), and AChE. With this model, we evaluated several drug compounds and food constituents reported to improve cholinergic function through various mechanisms. In addition, we conducted western blotting to identify the subtype of mAChR that is expressed on the cell line. Results Our cell-based assay system was capable of detecting increases in extracellular ACh levels induced by an AChE inhibitor at relatively high doses, as well as increases in intracellular ACh levels following the administration of lower AChE-inhibitor doses and an mAChR agonist. Moreover, increases in intracellular ACh levels were observed even after treatment with food constituents that have different mechanisms of action, such as Ch provision and ChAT activation. In addition, we revealed that LA-N-2 cells expressed mAChR M2. Conclusion The findings support our hypothesis and indicate that the developed assay model can broadly screen compounds from drugs to food ingredients, with varying strengths and mechanisms of action, to develop treatments for ACh-relevant phenomena, including dementia and aging-related cognitive decline.


2020 ◽  
Author(s):  
Ramona Meanti ◽  
Laura Rizzi ◽  
Elena Bresciani ◽  
Laura Molteni ◽  
Vittorio Locatelli ◽  
...  

AbstractHexarelin, a synthetic hexapeptide, protects cardiac and skeletal muscles by inhibiting apoptosis, both in vitro and in vivo. Moreover, evidence suggests that hexarelin could have important neuroprotective bioactivity.Oxidative stress and the generation of free radicals has been implicated in the etiologies of several neurodegenerative diseases, including amyotrophic lateral sclerosis, Parkinson’s disease, Alzheimer’s disease, Huntington’s disease and multiple sclerosis. In addition to direct oxidative stress, exogenous hydrogen peroxide (H2O2) can penetrate biological membranes and enhance the formation of other reactive oxygen species.The aim of this study was to examine the inhibitory influence of hexarelin on H2O2-induced apoptosis in Neuro-2A cells, a mouse neuroblastoma cell line. Our results indicate that H2O2 reduced the viability of Neuro-2A cells in a dose-related fashion. Furthermore, H2O2 induced significant changes in the morphology of Neuro-2A cells, reflected in the formation of apoptotic cell bodies, and an increase of nitric oxide (NO) production. Hexarelin effectively antagonized H2O2 oxidative damage to Neuro-2A cells as indicated by improved cell viability, normal morphology and reduced nitrite (NO2−) release. Hexarelin treatment of Neuro-2A cells also reduced mRNA levels of caspases−3 and −7 and those of the pro-apoptotic molecule Bax; by contrast, hexarelin treatment increased anti-apoptotic Bcl-2 mRNA levels. Hexarelin also reduced MAPKs phosphorylation induced by H2O2 and concurrently increased p-Akt protein expression.In conclusion, our results identify several neuroprotective and anti-apoptotic effects of hexarelin. These properties suggest that further investigation of hexarelin as a neuroprotective agent in an investigational and therapeutic context are merited.


2003 ◽  
Vol 284 (1) ◽  
pp. H385-H392 ◽  
Author(s):  
John C. Teeters ◽  
Cauveh Erami ◽  
Hua Zhang ◽  
James E. Faber

Previous in vitro and in vivo studies have shown that norepinephrine, acting through α1A-adrenoceptors, stimulates hypertrophy, proliferation, and migration of vascular smooth muscle cells and adventitial fibroblasts and may contribute to neointimal growth, lumen loss, and inward remodeling caused by iatrogenic wall injury and vascular disease. Our present aim was to determine whether intravenous administration of the α1A-adrenoceptor antagonist KMD-3213, at dosages without systemic hemodynamic effects, inhibits wall growth after injury. Inhibition of α1A-adrenoceptors with 12.8 and 32 μg/kg KMD-3213 had no effect on arterial pressure or renal and hindquarter resistances in anesthetized rats. A second group then received carotid balloon injury and continuous intravenous KMD-3213 at 4 and 10 μg · kg−1 · h−1for 2 wk. Mean, systolic, and diastolic arterial pressures and heart rate of conscious unrestrained rats were unaffected. KMD-3213 reduced neointima growth by ∼30 and 46% at the two doses ( P< 0.01). These data support the novel hypothesis that a direct α1A-adrenoceptor-dependent trophic action of catecholamines is augmented by injury and may contribute significantly to hypertrophic vascular disease.


2013 ◽  
Vol 29 (5) ◽  
pp. 1714-1720 ◽  
Author(s):  
M. WAHEED ROOMI ◽  
TATIANA KALINOVSKY ◽  
NUSRATH W. ROOMI ◽  
ALEKSANDRA NIEDZWIECKI ◽  
MATTHIAS RATH

2021 ◽  
Vol 12 ◽  
Author(s):  
Dewei He ◽  
Shoupeng Fu ◽  
Ang Zhou ◽  
Yingchun Su ◽  
Xiyu Gao ◽  
...  

Microglia, the main immune cells in the brain, participate in the innate immune response in the central nervous system (CNS). Studies have shown that microglia can be polarized into pro-inflammatory M1 and anti-inflammatory M2 phenotypes. Accumulated evidence suggests that over-activated M1 microglia release pro-inflammatory mediators that damage neurons and lead to Parkinson’s disease (PD). In contrast, M2 microglia release neuroprotective factors and exert the effects of neuroprotection. Camptothecin (CPT), an extract of the plant Camptotheca acuminate, has been reported to have anti-inflammation and antitumor effects. However, the effect of CPT on microglia polarization and microglia-mediated inflammation responses has not been reported. In our study we found that CPT improved motor performance of mice and reduced the loss of neurons in the substantia nigra (SN) of the midbrain in LPS-injected mice. In the mechanism study, we found that CPT inhibited M1 polarization of microglia and promotes M2 polarization via the AKT/Nrf2/HO-1 and NF-κB signals. Furthermore, CPT protected the neuroblastoma cell line SH-SY5Y and dopaminergic neuron cell line MN9D from damage mediated by microglia activation. In conclusion, our results demonstrate that CPT regulates the microglia polarization phenotype via activating AKT/Nrf2/HO-1 and inhibiting NF-κB pathways, inhibits neuro-inflammatory responses, and exerts neuroprotective effects in vivo and in vitro.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Yan Yang ◽  
Lili Ding ◽  
Qi Zhou ◽  
Li Fen ◽  
Yuhua Cao ◽  
...  

Abstract Background Aurora kinase A (AURKA) has been implicated in the regulation of cell cycle progression, mitosis and a key number of oncogenic signaling pathways in various malignancies including neuroblastoma. Small molecule inhibitors of AURKA have shown potential, but still not as good as expected effects in clinical trials. Little is known about this underlying mechanism. Here, we evaluated the inhibitory effects of AURKA inhibitor MLN8237 on neuroblastoma cells to understand the potential mechanisms responsible for tumor therapy. Methods MLN8237 treatment on neuroblastoma cell line IMR32 was done and in vivo inhibitory effects were investigated using tumor xenograft model. Cellular senescence was evaluated by senescence-associated β-gal Staining assay. Flow cytometry was used to tested cell cycle arrest and cell apoptosis. Senescence-associated signal pathways were detected by western blot. CD133 microbeads and microsphere formation were used to separate and enrich CD133+ cells. AURKA small interfering RNA transfection was carried to downregulate AURKA level. Finally, the combination of MLN8237 treatment with AURKA small interfering RNA transfection were adopted to evaluate the inhibitory effect on neuroblastoma cells. Results We demonstrate that MLN8237, an inhibitor of AURKA, induces the neuroblastoma cell line IMR32 into cellular senescence and G2/M cell phase arrest. Inactivation of AURKA results in MYCN destabilization and inhibits cell growth in vitro and in a mouse model. Although MLN8237 inhibits AURKA kinase activity, it has almost no inhibitory effect on the AURKA protein level. By contrast, MLN8237 treatment leads to abnormal high expression of AURKA in vitro and in vivo. Knockdown of AURKA reduces cell survival. The combination of MLN8237 with AURKA small interfering RNA results in more profound inhibitory effects on neuroblastoma cell growth. Moreover, MLN8237 treatment followed by AURKA siRNA forces senescent cells into apoptosis via suppression of the Akt/Stat3 pathway. Conclusions The effect of AURKA-targeted inhibition of tumor growth plays roles in both the inactivation of AURKA activity and the decrease in the AURKA protein expression level.


Perfusion ◽  
2002 ◽  
Vol 17 (2) ◽  
pp. 153-156 ◽  
Author(s):  
Anja Gerdes ◽  
Thorsten Hanke ◽  
Hans-H Sievers

Background: Prevention of intraoperative plaque dislodgement in patients with atherosclerotic ascending aorta by development of innovative aortic cannula designs gains growing interest in cardiac surgery. To increase knowledge about the hydrodynamics of the innovative Embol-X™ cannula, which includes an intra-aortic filter device targeting at atheromatous emboli capture, was the aim of the present study. Methods: Pressure gradients and back pressures of the Embol-X™ cannula were measured at varying flow rates in a mock circulation and compared with two commonly used single-stream cannulae. Results: At a flow rate of 5.5 l/min, pressure gradients across the Argyle™ and the RMI cannulae were 48% and 62% and back pressures 25% and 47% lower than the corresponding values across the Embol-X™ cannula. Conclusions: The novel concept of integrating a filter device may provide clinical advantages concerning neurologic outcome. Further in vivo studies seem to be desirable to obtain more information concerning the clinical effects of the Embol-X™ cannula hydrodynamics.


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