scholarly journals Hyperoxia, reactive oxygen species, and hyperventilation: oxygen sensitivity of brain stem neurons

2004 ◽  
Vol 96 (2) ◽  
pp. 784-791 ◽  
Author(s):  
Jay B. Dean ◽  
Daniel K. Mulkey ◽  
Richard A. Henderson ◽  
Stephanie J. Potter ◽  
Robert W. Putnam
Keyword(s):  
Oxidative Stress ◽  
Brain Stem ◽  
Brain Slices ◽  
Respiratory Control ◽  
In Vivo Studies ◽  
Future Research ◽  
Direct Effects ◽  
Underlying Assumption

Hyperoxia is a popular model of oxidative stress. However, hyperoxic gas mixtures are routinely used for chemical denervation of peripheral O2 receptors in in vivo studies of respiratory control. The underlying assumption whenever using hyperoxia is that there are no direct effects of molecular O2 and reactive O2 species (ROS) on brain stem function. In addition, control superfusates used routinely for in vitro studies of neurons in brain slices are, in fact, hyperoxic. Again, the assumption is that there are no direct effects of O2 and ROS on neuronal activity. Research contradicts this assumption by demonstrating that O2 has central effects on the brain stem respiratory centers and several effects on neurons in respiratory control areas; these need to be considered whenever hyperoxia is used. This mini-review summarizes the long-recognized, but seldom acknowledged, paradox of respiratory control known as hyperoxic hyperventilation. Several proposed mechanisms are discussed, including the recent hypothesis that hyperoxic hyperventilation is initiated by increased production of ROS during hyperoxia, which directly stimulates central CO2 chemoreceptors in the solitary complex. Hyperoxic hyperventilation may provide clues into the fundamental role of redox signaling and ROS in central control of breathing; moreover, oxidative stress may play a role in respiratory control dysfunction. The practical implications of brain stem O2 and ROS sensitivity are also considered relative to the present uses of hyperoxia in respiratory control research in humans, animals, and brain stem tissues. Recommendations for future research are also proposed.

Food Derived Bioactive Peptides for Health Enhancement and Management of Some Chronic Diseases

2019 ◽  
pp. 1-11
Author(s):  
A. F. Ogori ◽  
A. T. Girgih ◽  
J. O. Abu ◽  
M. O. Eke
Keyword(s):  
Oxidative Stress ◽  
Chronic Diseases ◽  
Molecular Mechanisms ◽  
Bioactive Peptides ◽  
Food Sources ◽  
In Vivo Studies ◽  
Future Research ◽  
Target Cells

The bioactive peptides produced by enzymatic hydrolysis, acid hydrolysis and fermentation approach have been identified and used widely in research. These methods are important in enhancement or prevention and management of chronic diseases that are ravaging the world such as type -2-diabetes, hypertension, oxidative stress, cancer, and obesity. Sources of bioactive peptides have been established ranging from plant to animal and marine foods that have pharmacological effects; however these effects are dependent on target cells and peptides structure and conformations.  Plants such as hemp and animal source such as milk among others validate the findings of In vitro and In-vivo studies and the efficiency of these bioactive peptides in the management of certain chronic diseases. This article reviews the literature on bioactive peptides with concern on food sources, production and bioactive peptides application in enhancement of health and management of hypertension, diabetes and oxidative stress.  Future research efforts on bioactive peptides should be directed towards elucidating specific sequenced bioactive peptides and their molecular mechanisms, through In-vivo and In-vitro studies for specific health condition in human using nutrigenomics and peptideomic approaches.

Dopamine Modulates Excitability of Basolateral Amygdala Neurons In Vitro

2005 ◽  
Vol 93 (3) ◽  
pp. 1598-1610 ◽  
Author(s):  
Sven Kröner ◽  
J. Amiel Rosenkranz ◽  
Anthony A. Grace ◽  
German Barrionuevo
Keyword(s):  
Basolateral Amygdala ◽  
Neuronal Response ◽  
Brain Slices ◽  
Receptor Activation ◽  
D1 Receptor ◽  
In Vivo Studies ◽  
Projection Neurons ◽  
Direct Effects

The amygdala plays a role in affective behaviors, which are modulated by the dopamine (DA) innervation of the basolateral amygdala complex (BLA). Although in vivo studies indicate that activation of DA receptors alters BLA neuronal activity, it is unclear whether DA exerts direct effects on BLA neurons or whether it acts via indirect effects on BLA afferents. Using whole cell patch-clamp recordings in rat brain slices, we investigated the site and mechanisms through which DA regulates the excitability of BLA neurons. Dopamine enhanced the excitability of BLA projection neurons in response to somatic current injections via a postsynaptic effect. Dopamine D1 receptor activation increased excitability and evoked firing, whereas D2 receptor activation increased input resistance. Current- and voltage-clamp experiments in projection neurons showed that D1 receptor activation enhanced excitability by modulating a 4-aminopyridine- and α-dendrotoxin-sensitive, slowly inactivating K+ current. Furthermore, DA and D1 receptor activation increased evoked firing in fast-spiking BLA interneurons. Consistent with a postsynaptic modulation of interneuron excitability, DA also increased the frequency of spontaneous inhibitory postsynaptic currents recorded in projection neurons without changing release of GABA. These data demonstrate that DA exerts direct effects on BLA projection neurons and indirect actions via modulation of interneurons that may work in concert to enhance the neuronal response to large, suprathreshold inputs, while suppressing weaker inputs.

scholarly journals Food Derived Bioactive Peptides for Health Enhancement and Management of Some Chronic Diseases

2019 ◽  
pp. 1-11
Author(s):  
A. F. Ogori ◽  
A. T. Girgih ◽  
J. O. Abu ◽  
M. O. Eke
Keyword(s):  
Oxidative Stress ◽  
Chronic Diseases ◽  
Molecular Mechanisms ◽  
Bioactive Peptides ◽  
Food Sources ◽  
In Vivo Studies ◽  
Future Research ◽  
Target Cells

The bioactive peptides produced by enzymatic hydrolysis, acid hydrolysis and fermentation approach have been identified and used widely in research. These methods are important in enhancement or prevention and management of chronic diseases that are ravaging the world such as type -2-diabetes, hypertension, oxidative stress, cancer, and obesity. Sources of bioactive peptides have been established ranging from plant to animal and marine foods that have pharmacological effects; however these effects are dependent on target cells and peptides structure and conformations.  Plants such as hemp and animal source such as milk among others validate the findings of In vitro and In-vivo studies and the efficiency of these bioactive peptides in the management of certain chronic diseases. This article reviews the literature on bioactive peptides with concern on food sources, production and bioactive peptides application in enhancement of health and management of hypertension, diabetes and oxidative stress.  Future research efforts on bioactive peptides should be directed towards elucidating specific sequenced bioactive peptides and their molecular mechanisms, through In-vivo and In-vitro studies for specific health condition in human using nutrigenomics and peptideomic approaches.

scholarly journals Alcohol-and-HIV-Induced Lysosomal Dysfunction Regulates Extracellular Vesicles Secretion in Vitro and in Liver-Humanized Mice

Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 29
Author(s):  
Raghubendra Singh Dagur ◽  
Moses New-Aaron ◽  
Murali Ganesan ◽  
Weimin Wang ◽  
Svetlana Romanova ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Extracellular Vesicles ◽  
Treated Group ◽  
Human Hepatocytes ◽  
In Vivo Studies ◽  
People Living With Hiv ◽  
Humanized Mouse Model ◽  
And Function

Background: Alcohol abuse is common in people living with HIV-1 and dramaticallyenhances the severity of HIV-induced liver damage by inducing oxidative stress and lysosomaldysfunction in the liver cells. We hypothesize that the increased release of extracellular vesicles(EVs) in hepatocytes and liver humanized mouse model is linked to lysosome dysfunction. Methods:The study was performed on primary human hepatocytes and human hepatoma RLWXP-GFP (Huh7.5 cells stably transfected with CYP2E1 and XPack-GFP) cells and validated on ethanol-fed liverhumanizedfumarylacetoacetate hydrolase (Fah)-/-, Rag2-/-, common cytokine receptor gamma chainknockout (FRG-KO) mice. Cells and mice were infected with HIV-1ADA virus. Results: We observedan increase in the secretion of EVs associated with a decrease in lysosomal activity and expressionof lysosomal-associated membrane protein 1. Next-generation RNA sequencing of primary humanhepatocytes revealed 63 differentially expressed genes, with 13 downregulated and 50 upregulatedgenes in the alcohol–HIV-treated group. Upstream regulator analysis of differentially expressedgenes through Ingenuity Pathway Analysis identified transcriptional regulators affecting downstreamgenes associated with increased oxidative stress, lysosomal associated disease, and function andEVs biogenesis. Our in vitro findings were corroborated by in vivo studies on human hepatocytetransplantedhumanized mice, indicating that intensive EVs’ generation by human hepatocytes andtheir secretion to serum was associated with increased oxidative stress and reduction in lysosomalactivities triggered by HIV infection and ethanol diet. Conclusion: HIV-and-ethanol-metabolisminducedEVs release is tightly controlled by lysosome status in hepatocytes and participates in thedevelopment of double-insult-induced liver injury.

scholarly journals Contribution to the biological interest of Valeriana officinalis: an update

2021 ◽  
Vol 42 ◽  
pp. e67649
Author(s):  
Marta Sánchez ◽  
Elena González-Burgos ◽  
Irene Iglesias ◽  
M. Pilar Gómez-Serranillos Cuadrado
Keyword(s):  
Clinical Trials ◽  
Nervous System ◽  
Biological Activities ◽  
In Vivo Studies ◽  
Neuroprotective Activity ◽  
Future Research ◽  
Valeriana Officinalis ◽  
Valerenic Acid

Valeriana officinalis L. (Caprifoliaceae family) has been traditionally used to treat mild nervous tension and sleep problems. The basis of these activities are mainly attributed to valerenic acid through the modulation of the GABA receptor. Moreover, V. officinalis is claimed to have other biological activities such as cardiovascular benefits, anticancer, antimicrobial and spasmolytic.  The current review aims to update the biological and pharmacological studies (in vitro, in vivo and clinical trials) of V. officinalis and its major secondary metabolites in order to guide future research. Databases PubMed, Science Direct and Scopus were used for literature search including original papers written in English and published between 2014 and 2020. There have been identified 33 articles which met inclusion criteria. Most of these works were performed with V. officinalis extracts and only a few papers (in vitro and in vivo studies) evaluated the activity of isolated compounds (valerenic acid and volvalerenal acid K). In vitro studies focused on studying antioxidant and neuroprotective activity. In vivo studies and clinical trials mainly investigated activities on the nervous system (anticonvulsant activity, antidepressant, cognitive problems, anxiety and sleep disorders). Just few studies were focused on other different activities, highlight effects on symptoms of premenstrual and postmenopausal syndromes. Valeriana officinalis continues to be one of the medicinal plants most used by today's society for its therapeutic properties and whose biological and pharmacological activities continue to arouse great scientific interest as evidenced in recent publications. This review shows scientific evidence on traditional uses of V. officinalis on nervous system.

scholarly journals The Emerging Role and Promise of Circular RNAs in Obesity and Related Metabolic Disorders

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1473
Author(s):  
Mohamed Zaiou
Keyword(s):  
Rna Binding ◽  
Metabolic Diseases ◽  
Rna Binding Proteins ◽  
In Vivo Studies ◽  
Future Research ◽  
Circular Rnas ◽  
Exciting Field ◽  
Rna Molecules

Circular RNAs (circRNAs) are genome transcripts that are produced from back-splicing of specific regions of pre-mRNA. These single-stranded RNA molecules are widely expressed across diverse phyla and many of them are stable and evolutionary conserved between species. Growing evidence suggests that many circRNAs function as master regulators of gene expression by influencing both transcription and translation processes. Mechanistically, circRNAs are predicted to act as endogenous microRNA (miRNA) sponges, interact with functional RNA-binding proteins (RBPs), and associate with elements of the transcriptional machinery in the nucleus. Evidence is mounting that dysregulation of circRNAs is closely related to the occurrence of a range of diseases including cancer and metabolic diseases. Indeed, there are several reports implicating circRNAs in cardiovascular diseases (CVD), diabetes, hypertension, and atherosclerosis. However, there is very little research addressing the potential role of these RNA transcripts in the occurrence and development of obesity. Emerging data from in vitro and in vivo studies suggest that circRNAs are novel players in adipogenesis, white adipose browning, obesity, obesity-induced inflammation, and insulin resistance. This study explores the current state of knowledge on circRNAs regulating molecular processes associated with adipogenesis and obesity, highlights some of the challenges encountered while studying circRNAs and suggests some perspectives for future research directions in this exciting field of study.

scholarly journals Fighting Liver Fibrosis with Naturally Occurring Antioxidants

Planta Medica ◽  
2018 ◽  
Vol 84 (18) ◽  
pp. 1318-1333 ◽  
Author(s):  
Ligen Lin ◽  
Fayang Zhou ◽  
Shengnan Shen ◽  
Tian Zhang
Keyword(s):  
Oxidative Stress ◽  
Liver Fibrosis ◽  
Normal Liver ◽  
Natural Antioxidants ◽  
In Vivo Studies ◽  
Lead Compounds ◽  
Naturally Occurring ◽  
Wound Healing Response

AbstractLiver fibrosis is a wound-healing response characterized by the accumulation of extracellular matrix following various liver injuries, which results in the deformation of the normal liver architecture and the development of liver cirrhosis and even hepatocellular carcinoma. Numerous in vitro and in vivo studies indicated that oxidative stress mediates the initiation and progression of liver fibrosis. Overaccumulation of reactive oxygen species disrupts macromolecules, induces necrosis and apoptosis of hepatocytes, stimulates the production of pro-fibrogenic mediators, and directly activates hepatic stellate cells, thereby resulting in liver damage and initiating liver fibrosis. Ameliorating oxidative stress is a potential therapeutic strategy for the treatment of liver fibrosis. Natural antioxidants have attracted increasing attention in treating liver fibrosis due to their safety and efficacy. In this review, the pathogenesis of liver fibrosis and the role of oxidative stress in liver fibrosis were discussed. Naturally occurring antioxidants that can treat and prevent liver fibrosis were summarized. Advances in clinical trials were also presented. The main purpose of this review is to provide a comprehensive and up-to-date knowledge from the biological importance of oxidative stress in liver fibrosis to representative antioxidants for treating liver fibrosis. Naturally occurring antioxidants show a potential for further investigations as lead compounds in fighting liver fibrosis.

scholarly journals Dextromethorphan Reduces Oxidative Stress and Inhibits Uremic Artery Calcification

2021 ◽  
Vol 22 (22) ◽  
pp. 12277
Author(s):  
En-Shao Liu ◽  
Nai-Ching Chen ◽  
Tzu-Ming Jao ◽  
Chien-Liang Chen
Keyword(s):  
Oxidative Stress ◽  
Nadph Oxidase ◽  
Vascular Calcification ◽  
Wistar Rats ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Oxidase Inhibitor ◽  
In Vivo Studies ◽  
Ros Production

Medial vascular calcification has emerged as a key factor contributing to cardiovascular mortality in patients with chronic kidney disease (CKD). Vascular smooth muscle cells (VSMCs) with osteogenic transdifferentiation play a role in vascular calcification. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitors reduce reactive oxygen species (ROS) production and calcified-medium–induced calcification of VSMCs. This study investigates the effects of dextromethorphan (DXM), an NADPH oxidase inhibitor, on vascular calcification. We used in vitro and in vivo studies to evaluate the effect of DXM on artery changes in the presence of hyperphosphatemia. The anti-vascular calcification effect of DXM was tested in adenine-fed Wistar rats. High-phosphate medium induced ROS production and calcification of VSMCs. DXM significantly attenuated the increase in ROS production, the decrease in ATP, and mitochondria membrane potential during the calcified-medium–induced VSMC calcification process (p < 0.05). The protective effect of DXM in calcified-medium–induced VSMC calcification was not further increased by NADPH oxidase inhibitors, indicating that NADPH oxidase mediates the effect of DXM. Furthermore, DXM decreased aortic calcification in Wistar rats with CKD. Our results suggest that treatment with DXM can attenuate vascular oxidative stress and ameliorate vascular calcification.

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