Effects of Agents Used in the Pharmacotherapy of Cerebrovascular Disease on the Oxygen Consumption of Isolated Cerebral Mitochondria

A number of drugs used in the pharmacotherapy of cerebral metabolic and vascular disease have been studied for their effects on the respiration of mitochondria isolated from the rat brain. Some of these agents increased the respiratory control ratio by more than 5% from base-line values (at p < 0.05), namely, aminophylline, dihydroergotoxine, ifenprodil, nicergoline, raubasine, and vincamine. The ability of these agents to increase the efficiency of mitochondrial respiration could be correlated with two other attributes peculiar to these five drugs: their ability to contract cerebrovascular smooth muscle when studied in vitro and their ability to decrease the volume of infarcted brain tissue following experimental occlusion of the middle cerebral artery in the cat. Papaverine and its derivatives (naftidrofuryl, viquidil, YC-93) decreased respiratory control, an effect that might correlate with their capacity to effect a vasodilatation of the cerebral vessels and their inefficacy in models of acute cerebral infarction. There is a considerable body of evidence suggesting that one of the earliest and most fundamental perturbations of cerebral ischaemia is a loss of respiratory control. Ifenprodil, vincamine, and some related “anti-ischaemic” compounds are capable of increasing respiratory control in normal cerebral mitochondria, and this capacity might well help to explain their therapeutic potential in cerebrovascular disorders in which energy supply to the brain is limited.

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Computational Insight into the Effect of Natural Compounds on the Destabilization of Preformed Amyloid-β(1-40) Fibrils

10.20944/preprints201805.0380.v1 ◽

2018 ◽

Author(s):

Francesco Tavanti ◽

Alfonso Pedone ◽

Maria Cristina Menziani

Keyword(s):

Therapeutic Strategy ◽

Therapeutic Potential ◽

Structure Stability ◽

Insoluble Form ◽

The Brain ◽

Identification And Characterization ◽

Insight Into

One of the principal hallmarks of Alzheimer’s disease (AD) is related to the aggregation of amyloid-β fibrils in an insoluble form in the brain, also known as amyloidosis. Therefore, a prominent therapeutic strategy against AD consists either in blocking the amyloid aggregation and/or destroying the already formed aggregates. Natural products have shown significant therapeutic potential as amyloid inhibitors from in vitro studies as well as in vivo animal tests. In this study, the interaction of five natural biophenols (curcumin, dopamine, (-)-Epigallocatechin-3-gallate, Quercetin, and Rosmarinic acid) with the amyloid-β(1-40) fibrils has been studied through computational simulations. The results allowed the identification and characterization of the different binding modalities of each compounds and their consequences on fibril dynamics and aggregation. It emerges that the lateral aggregation of the fibrils is strongly influenced by the intercalation of the ligands, which modulate the double-layered structure stability.

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A comparison of AAV-vector production methods for gene therapy and preclinical assessment

Scientific Reports ◽

10.1038/s41598-020-78521-w ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Marcus Davidsson ◽

Matilde Negrini ◽

Swantje Hauser ◽

Alexander Svanbergsson ◽

Marcus Lockowandt ◽

...

Keyword(s):

Gene Therapy ◽

Therapeutic Potential ◽

High Titer ◽

Cell Loss ◽

Repeated Administration ◽

Transduction Efficiency ◽

Aav Vector ◽

The Brain

AbstractAdeno Associated Virus (AAV)-mediated gene expression in the brain is widely applied in the preclinical setting to investigate the therapeutic potential of specific molecular targets, characterize various cellular functions, and model central nervous system (CNS) diseases. In therapeutic applications in the clinical setting, gene therapy offers several advantages over traditional pharmacological based therapies, including the ability to directly manipulate disease mechanisms, selectively target disease-afflicted regions, and achieve long-term therapeutic protein expression in the absence of repeated administration of pharmacological agents. Next to the gold-standard iodixanol-based AAV vector production, we recently published a protocol for AAV production based on chloroform-precipitation, which allows for fast in-house production of small quantities of AAV vector without the need for specialized equipment. To validate our recent protocol, we present here a direct side-by-side comparison between vectors produced with either method in a series of in vitro and in vivo assays with a focus on transgene expression, cell loss, and neuroinflammatory responses in the brain. We do not find differences in transduction efficiency nor in any other parameter in our in vivo and in vitro panel of assessment. These results suggest that our novel protocol enables most standardly equipped laboratories to produce small batches of high quality and high titer AAV vectors for their experimental needs.

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β-hydroxybutyrate Impedes the Progression of Alzheimer’s Disease and Atherosclerosis in ApoE-Deficient Mice

Nutrients ◽

10.3390/nu12020471 ◽

2020 ◽

Vol 12 (2) ◽

pp. 471 ◽

Cited By ~ 3

Author(s):

Manigandan Krishnan ◽

Jong Su Hwang ◽

Mikyung Kim ◽

Yun Jin Kim ◽

Ji Hae Seo ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Therapeutic Potential ◽

Density Lipoprotein ◽

In Vitro Study ◽

Substantia Nigra Pars Compacta ◽

Apo E ◽

The Brain ◽

Deficient Mice

β-hydroxybutyrate (β-OHB) has been shown to exert an anti-inflammatory activity. Apolipoprotein-E (ApoE) is strongly associated with atherosclerosis and Alzheimer’s disease (AD). This study aimed to explore the therapeutic effect of β-OHB in the brain and the aorta of high-fat diet (HFD)-fed ApoE-deficient mice. We found in Apo-E deficient mice that β-OHB attenuated lipid deposition in the choroid plexus (ChP) and decreased amyloid plaque in the substantia nigra pars compacta. We also found decreased CD68-positive macroglia infiltration of the ChP in β-OHB-treated ApoE-deficient mice. β-OHB treatment ameliorated IgG extravasation into the hippocampal region of the brain. In vitro study using ChP mice cell line revealed that β-OHB attenuated oxidized low-density lipoprotein-induced ApoE-specific differentially expressed inflammatory ChP genes. Treatment with β-OHB reduced aortic plaque formation without affecting blood lipid profiles and decreased serum production of resistin, a well-established risk factor for both AD and atherosclerosis. Thus, the current study suggests and describes the therapeutic potential of β-OHB for the treatment of AD and atherosclerosis.

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Effects of 6-hydroxydopamine on oxidative phosphorylation of mitochondria from rat striatum, cortex, and liver

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y88-063 ◽

1988 ◽

Vol 66 (3) ◽

pp. 376-379 ◽

Cited By ~ 9

Author(s):

J. H. Thakar ◽

M. N. Hassan

Keyword(s):

Oxidative Phosphorylation ◽

Incubation Medium ◽

Respiratory Control ◽

Rat Striatum ◽

Respiratory Control Ratio ◽

Chemical Sympathectomy ◽

Mitochondrial Oxidative Phosphorylation ◽

Consumption Ratio ◽

6 Hydroxydopamine

The catecholamine neurotoxin 6-hydroxydopamine (6-OHDA) has been used to produce cardiac chemical sympathectomy as well as a model of parkinsonism. Several mechanisms have been proposed to explain its cytotoxicity, including the productions of quinones, hydrogen peroxide, and free radicals by autooxidation and the uncoupling of mitochondrial oxidative phosphorylation. We have observed that 6-OHDA at a concentration of 0.05 mM rapidly consumes oxygen from the mitochondrial incubation medium but does not affect oxidative phosphorylation in the mitochondria from rat striatum, cortex, and liver. At the higher concentration of 0.5 mM, 6-OHDA consumes all of the available oxygen from the incubation medium. Mitochondria exposed to this concentration of 6-OHDA show decreases in the respiratory control ratio and adenosine triphosphate synthesis as measured by the consumption ratio of ADP to oxygen. Thus, only the higher (0.5 mM) concentration of 6-OHDA, which produces anoxia in vitro, also causes mitochondrial damage.

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Carnosine Protects Macrophages against the Toxicity of Aβ1-42 Oligomers by Decreasing Oxidative Stress

Biomedicines ◽

10.3390/biomedicines9050477 ◽

2021 ◽

Vol 9 (5) ◽

pp. 477

Author(s):

Giuseppe Caruso ◽

Cristina Benatti ◽

Nicolò Musso ◽

Claudia G. Fresta ◽

Annamaria Fidilio ◽

...

Keyword(s):

Oxidative Stress ◽

Therapeutic Potential ◽

Radical Scavenging ◽

Antioxidant Systems ◽

Trypan Blue Exclusion ◽

New Findings ◽

Pre Treatment ◽

The Brain

Carnosine (β-alanyl-L-histidine) is a naturally occurring endogenous peptide widely distributed in excitable tissues such as the brain. This dipeptide has well-known antioxidant, anti-inflammatory, and anti-aggregation activities, and it may be useful for treatment of neurodegenerative disorders such as Alzheimer’s disease (AD). In this disease, peripheral infiltrating macrophages play a substantial role in the clearance of amyloid beta (Aβ) peptides from the brain. Correspondingly, in patients suffering from AD, defects in the capacity of peripheral macrophages to engulf Aβ have been reported. The effects of carnosine on macrophages and oxidative stress associated with AD are consequently of substantial interest for drug discovery in this field. In the present work, a model of stress induced by Aβ1-42 oligomers was investigated using a combination of methods including trypan blue exclusion, microchip electrophoresis with laser-induced fluorescence, flow cytometry, fluorescence microscopy, and high-throughput quantitative real-time PCR. These assays were used to assess the ability of carnosine to protect macrophage cells, modulate oxidative stress, and profile the expression of genes related to inflammation and pro- and antioxidant systems. We found that pre-treatment of RAW 264.7 macrophages with carnosine counteracted cell death and apoptosis induced by Aβ1-42 oligomers by decreasing oxidative stress as measured by levels of intracellular nitric oxide (NO)/reactive oxygen species (ROS) and production of peroxynitrite. This protective activity of carnosine was not mediated by modulation of the canonical inflammatory pathway but instead can be explained by the well-known antioxidant and free-radical scavenging activities of carnosine, enhanced macrophage phagocytic activity, and the rescue of fractalkine receptor CX3CR1. These new findings obtained with macrophages challenged with Aβ1-42 oligomers, along with the well-known multimodal mechanism of action of carnosine in vitro and in vivo, substantiate the therapeutic potential of this dipeptide in the context of AD pathology.

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GAPDH controls extracellular vesicle biogenesis and enhances therapeutic potential of EVs in silencing the Huntingtin gene in mice via siRNA delivery

10.1101/2020.01.09.899880 ◽

2020 ◽

Author(s):

Ghulam Hassan Dar ◽

Cláudia C. Mendes ◽

Wei-Li Kuan ◽

Mariana Conceição ◽

Samir El-Andaloussi ◽

...

Keyword(s):

Drug Delivery ◽

Therapeutic Potential ◽

Sirna Delivery ◽

Extracellular Vesicle ◽

Glycolytic Enzyme ◽

Target Cells ◽

Binding Motif ◽

Systemic Injection ◽

The Brain

AbstractExtracellular vesicles (EVs) are biological nanoparticles with important roles in intercellular communication and pathophysiology. Their capacity to transfer biomolecules between cells has sparked efforts to bioengineer EVs as drug delivery vehicles. However, a better understanding of EV biogenesis mechanisms and function is required to unleash their considerable therapeutic potential. Here we demonstrate a novel role for GAPDH, a glycolytic enzyme, in EV assembly and secretion, and we exploit these findings to develop a GAPDH-based methodology to load therapeutic siRNAs onto EVs for targeted drug delivery to the brain. In a series of experiments, we observe high levels of GAPDH binding to the outer surface of EVs via a phosphatidylserine binding motif, designated as G58, and discover that the tetrameric nature of GAPDH promotes extensive EV aggregation. Studies in a Drosophila EV biogenesis model demonstrate that GAPDH is absolutely required for normal generation of intraluminal vesicles in endosomal compartments and promotes vesicle clustering both inside and outside the cell. Fusing a GAPDH-derived G58 peptide to dsRNA-binding motifs permits highly efficient loading of RNA-based drugs such as siRNA onto the surface of EVs. Such vesicles efficiently deliver siRNA to target cells in vitro and into the brain of a Huntington’s disease mouse model after systemic injection, resulting in silencing of the huntingtin gene in multiple anatomical regions of the brain and modulation of phenotypic features of disease. Taken together, our study demonstrates a novel role for GAPDH in EV biogenesis, and that the presence of free GAPDH binding sites on EVs can be effectively exploited to substantially enhance the therapeutic potential of EV-mediated drug delivery to the brain.

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Queuine, a bacterial derived hypermodified nucleobase, shows protection in in vitro models of neurodegeneration

10.1101/2021.01.20.427538 ◽

2021 ◽

Author(s):

Patricia Richard ◽

Xavier Manière ◽

Lucie Kozlowski ◽

Hélène Guillorit ◽

Patrice Garnier ◽

...

Keyword(s):

Neurodegenerative Disorders ◽

Therapeutic Potential ◽

Mrna Translation ◽

Alpha Synuclein ◽

In Vitro Models ◽

Wobble Position ◽

Mitochondrial Defects ◽

Alpha Synuclein Aggregation ◽

The Brain

AbstractGrowing evidence suggests that human gut bacteria, comprising the microbiome that communicates with the brain through the so-called ‘gut-brain-axis’, are linked to neurodegenerative disorders. Imbalances in the microbiome of Parkinson’s disease (PD) and Alzheimer’s disease (AD) patients have been detected in several studies. Queuine is a hypermodified nucleobase enriched in the brain and exclusively produced by bacteria and salvaged by humans through their gut epithelium. Queuine replaces guanine at the wobble position of tRNAs with GUN anticodons and promotes efficient cytoplasmic and mitochondrial mRNA translation.To elucidate whether queuine could facilitate protein folding and prevent aggregation and mitochondrial defects, hallmarks of neurodegenerative disorders, we tested the effect of chemically synthesized queuine, STL-101, in several in vitro models of neurodegeneration. Treatment with STL-101 led to increased neuronal survival as well as a significant decrease in hyper-phosphorylated alpha-synuclein, a marker of alpha-synuclein aggregation in a PD model and a decrease in tau hyperphosphorylation in an AD model. Our work has identified a new role for queuine in neuroprotection uncovering a therapeutic potential for STL-101 in neurological disorders.

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Parkinson’s disease recovery by GM1 oligosaccharide treatment in the B4galnt1+/− mouse model

Scientific Reports ◽

10.1038/s41598-019-55885-2 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 10

Author(s):

Elena Chiricozzi ◽

Laura Mauri ◽

Giulia Lunghi ◽

Erika Di Biase ◽

Maria Fazzari ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Therapeutic Potential ◽

Physical Symptoms ◽

Wild Type ◽

Ganglioside Content ◽

Sporadic Parkinson’S Disease ◽

Specific Membrane ◽

The Brain

AbstractGiven the recent in vitro discovery that the free soluble oligosaccharide of GM1 is the bioactive portion of GM1 for neurotrophic functions, we investigated its therapeutic potential in the B4galnt1+/− mice, a model of sporadic Parkinson’s disease. We found that the GM1 oligosaccharide, systemically administered, reaches the brain and completely rescues the physical symptoms, reduces the abnormal nigral α-synuclein content, restores nigral tyrosine hydroxylase expression and striatal neurotransmitter levels, overlapping the wild-type condition. Thus, this study supports the idea that the Parkinson’s phenotype expressed by the B4galnt1+/− mice is due to a reduced level of neuronal ganglioside content and lack of interactions between the oligosaccharide portion of GM1 with specific membrane proteins. It also points to the therapeutic potential of the GM1 oligosaccharide for treatment of sporadic Parkinson’s disease.

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Development in rats of the brain-pituitary-adrenal response to hypoglycemia in vivo and in vitro

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1989.257.5.e757 ◽

1989 ◽

Vol 257 (5) ◽

pp. E757-E763 ◽

Cited By ~ 4

Author(s):

E. P. Widmaier

Keyword(s):

Base Line ◽

Adult Rats ◽

Glucose Levels ◽

Altered Glucose ◽

Dose Dependent Fashion ◽

Adrenal Response ◽

Old Rats ◽

The Brain

To clarify the nature of the stress hyporesponsive period that occurs in neonatal rats, the development of the response of the brain-pituitary-adrenal axis to hypoglycemia stress in rats was assessed in vivo and in vitro. Hypothalami were removed from the brains of neonatal (9-35 days postnatal) or adult rats and incubated in vitro for sequential 30-min periods in Krebs buffer for determination of corticotropin-releasing factor (CRF) secretion under conditions of altered glucose concentrations. As expected from previous studies, CRF secretion from adult hypothalami was significantly increased in severely hypoglycemic conditions (0.55 mM glucose) by approximately 50% above base-line values (in 5.5 mM glucose). However, lowering glucose did not elicit an increase in CRF release from hypothalami of rats less than 35 days of age. Hypothalami obtained from rats less than or equal to 24 days old also failed to show consistent secretory responses to potassium depolarization. At 35 days postnatal the response to hypoglycemia was significant and similar to the adult response. To determine if the lack of hypothalamic response to hypoglycemia in vitro could be correlated with the in vivo responses to hypoglycemia, rats aged 4 days to adult were injected intraperitoneally with porcine insulin and killed at different times after injection. Insulin injections lowered plasma glucose levels in fasted 4-day-old rats in a dose-dependent fashion, but a nadir in glucose (approximately 40 mg/dl) was not reached until 90 min; the same treatment produced a nadir in glucose within 30 min in fasted rats 10 days old and older, suggesting that the 4-day-old rats are relatively insulin insensitive.(ABSTRACT TRUNCATED AT 250 WORDS)

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Queuine, a bacterial-derived hypermodified nucleobase, shows protection in in vitro models of neurodegeneration

PLoS ONE ◽

10.1371/journal.pone.0253216 ◽

2021 ◽

Vol 16 (8) ◽

pp. e0253216

Author(s):

Patricia Richard ◽

Lucie Kozlowski ◽

Hélène Guillorit ◽

Patrice Garnier ◽

Nicole C. McKnight ◽

...

Keyword(s):

Protein Misfolding ◽

Therapeutic Potential ◽

Mrna Translation ◽

Alpha Synuclein ◽

In Vitro Models ◽

Unfolded Protein ◽

Healthy Humans ◽

Wobble Position ◽

The Brain

Growing evidence suggests that human gut bacteria, which comprise the microbiome, are linked to several neurodegenerative disorders. An imbalance in the bacterial population in the gut of Parkinson’s disease (PD) and Alzheimer’s disease (AD) patients has been detected in several studies. This dysbiosis very likely decreases or increases microbiome-derived molecules that are protective or detrimental, respectively, to the human body and those changes are communicated to the brain through the so-called ‘gut-brain-axis’. The microbiome-derived molecule queuine is a hypermodified nucleobase enriched in the brain and is exclusively produced by bacteria and salvaged by humans through their gut epithelium. Queuine replaces guanine at the wobble position (position 34) of tRNAs with GUN anticodons and promotes efficient cytoplasmic and mitochondrial mRNA translation. Queuine depletion leads to protein misfolding and activation of the endoplasmic reticulum stress and unfolded protein response pathways in mice and human cells. Protein aggregation and mitochondrial impairment are often associated with neural dysfunction and neurodegeneration. To elucidate whether queuine could facilitate protein folding and prevent aggregation and mitochondrial defects that lead to proteinopathy, we tested the effect of chemically synthesized queuine, STL-101, in several in vitro models of neurodegeneration. After neurons were pretreated with STL-101 we observed a significant decrease in hyperphosphorylated alpha-synuclein, a marker of alpha-synuclein aggregation in a PD model of synucleinopathy, as well as a decrease in tau hyperphosphorylation in an acute and a chronic model of AD. Additionally, an associated increase in neuronal survival was found in cells pretreated with STL-101 in both AD models as well as in a neurotoxic model of PD. Measurement of queuine in the plasma of 180 neurologically healthy individuals suggests that healthy humans maintain protective levels of queuine. Our work has identified a new role for queuine in neuroprotection uncovering a therapeutic potential for STL-101 in neurological disorders.

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