scholarly journals Pathophysiological In Vitro Profile of Neuronal Differentiated Cells Derived from Niemann-Pick Disease Type C2 Patient-Specific iPSCs Carrying the NPC2 Mutations c.58G>T/c.140G>T

2021 ◽  
Vol 22 (8) ◽  
pp. 4009
Author(s):  
Maik Liedtke ◽  
Christin Völkner ◽  
Alexandra V. Jürs ◽  
Franziska Peter ◽  
Michael Rabenstein ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Transmembrane Protein ◽  
Hereditary Disease ◽  
Cholesterol Homeostasis ◽  
Patient Specific ◽  
Differentiated Cells ◽  
Npc1 Gene ◽  
Niemann Pick

Niemann-Pick type C2 (NP-C2) disease is a rare hereditary disease caused by mutations in the NPC2 gene. NPC2 is a small, soluble protein consisting of 151 amino acids, primarily expressed in late endosomes and lysosomes (LE/LY). Together with NPC1, a transmembrane protein found in these organelles, NPC2 accomplishes the exclusion of cholesterol; thus, both proteins are essential to maintain cellular cholesterol homeostasis. Consequently, mutations in the NPC2 or NPC1 gene result in pathophysiological accumulation of cholesterol and sphingolipids in LE/LY. The vast majority of Niemann-Pick type C disease patients, 95%, suffer from a mutation of NPC1, and only 5% display a mutation of NPC2. The biochemical phenotype of NP-C1 and NP-C2 appears to be indistinguishable, and both diseases share several commonalities in the clinical manifestation. Studies of the pathological mechanisms underlying NP-C2 are mostly based on NP-C2 animal models and NP-C2 patient-derived fibroblasts. Recently, we established induced pluripotent stem cells (iPSCs), derived from a donor carrying the NPC2 mutations c.58G>T/c.140G>T. Here, we present a profile of pathophysiological in vitro features, shared by NP-C1 and NP-C2, of neural differentiated cells obtained from the patient specific iPSCs. Profiling comprised a determination of the NPC2 protein level, detection of cholesterol accumulation by filipin staining, analysis of oxidative stress, and determination of autophagy. As expected, the NPC2-deficient cells displayed a significantly reduced amount of NPC2 protein, and, accordingly, we observed a significantly increased amount of cholesterol. Most notably, NPC2-deficient cells displayed only a slight increase of reactive oxygen species (ROS), suggesting that they do not suffer from oxidative stress and express catalase at a high level. As a site note, comparable NPC1-deficient cells suffer from a lack of catalase and display an increased level of ROS. In summary, this cell line provides a valuable tool to gain deeper understanding, not only of the pathogenic mechanism of NP-C2, but also of NP-C1.

scholarly journals Comparative Phytochemical, Antioxidant and Haemostatic Studies of Preparations from Selected Vegetables from Cucurbitaceae Family

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4326
Author(s):  
Agata Rolnik ◽  
Iwona Kowalska ◽  
Agata Soluch ◽  
Anna Stochmal ◽  
Beata Olas
Keyword(s):  
Oxidative Stress ◽  
Thrombin Time ◽  
Phytochemical Composition ◽  
Significant Interest ◽  
Phytochemical Compounds ◽  
Potential Use ◽  
Insight Into ◽  
Cucurbitaceae Family

The aim of this study was to provide detailed insight into the chemical composition and activity of five cucurbit vegetable preparations (pumpkin, zucchini, cucumber, white and yellow pattypan squash), each containing various phytochemical compounds with potential use against oxidative stress induced by the hydroxyl radical donors in human plasma in vitro. We studied the antiradical capacity of vegetable preparations using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method. As oxidative stress may induce changes in hemostasis, our aim included the determination of their effect on three selected hemostatic parameters of plasma, which are three coagulation times: PT (prothrombin time), APTT (activated partial thromboplastin time) and TT (thrombin time). However, none of used vegetable preparations changed APTT, PT or TT compared to the control. The phytochemical composition of the tested preparations was determined by UPLC-ESI-QTOF-MS. In our in vitro experiments, while all five tested preparations had antioxidant potential, the preparation from yellow pattypan squash showed the strongest potential. All cucurbit vegetable preparations inhibited lipid peroxidation. Only zucchini did not have an effect on protein carbonylation and only yellow pattypan squash inhibited thiol oxidation. The antioxidant activity of cucurbits appears to have triggered significant interest in multiple applications, including CVDs (cardiovascular diseases) associated with oxidative stress, which can be treated by supplementation based on these vegetables.

scholarly journals Determination of activity of antioxidants in human subjects

1999 ◽  
Vol 58 (4) ◽  
pp. 1015-1024 ◽  
Author(s):  
Garry G. Duthie
Keyword(s):  
Oxidative Stress ◽  
Human Subjects ◽  
Control Schemes ◽  
Total Antioxidant ◽  
Plasma Measurements ◽  
Determination Of Activity ◽  
Nutritional Antioxidants

Evidence from biochemical and animal models suggests that nutritional antioxidants should inhibit the development of diseases such as CHD and certain cancers. This evidence is not clearly corroborated by intervention studies in human subjects, due, in part, to inadequacies in current analytical methodologies. Althoughin vitroassays can give useful information on the attributes required by a compound to act as an antioxidant, results may have little nutritional relevance due to limited bioavailability. The determination of antioxidants in blood is often used as a measure of antioxidant statusin vivo, but may not necessarily reflect concentrations in target tissues where oxidative stress is greatest. In addition, the accumulation of antioxidants in selective tissues may not be apparent from plasma measurements. Participation in quality-control schemes for antioxidant determination by HPLC allows inter-laboratory comparison of results. Moderation of indices of oxidative damage to lipids, proteins and DNA can provide information on the effectiveness of compounds as nutritional antioxidants. However, most current methods of assessing oxidative stress are subject to confounding factors of non-oxidative origin. Assays for total antioxidant capacity in plasma differ in their type of oxidation source, target and measurement used to detect the oxidized product. They give different results, should never be used in isolation, and results should be interpreted with caution. Until more is known about the activity and metabolic fate of antioxidants, caution should be exercised in the consumption of large amounts of commercially-available antioxidant preparations.

DMT1-Mutant Erythrocytes Have Shortened Life Span, Accelerated Glycolysis and Increased Oxidative Stress

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 957-957
Author(s):  
Zuzana Zidova ◽  
Pavla Pospisilova ◽  
Renata Mojzikova ◽  
Katarina Kapralova ◽  
Dalibor Dolezal ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Life Span ◽  
Conflicts Of Interest ◽  
Transmembrane Protein ◽  
Erythroid Differentiation ◽  
Compound Heterozygous ◽  
Divalent Metal Transporter 1 ◽  
Divalent Metal Transporter

Abstract Divalent metal transporter 1 (DMT1, also known as NRAMP2 and SLC11A2) is a transmembrane protein important for intestinal iron (Fe2+) absorption and erythroid iron utilization. Homozygous or compound heterozygous mutations in DMT1 are associated with moderate to severe hypochromic microcytic anemia in human patients and a mouse model - mk/mk mice. We have previously reported that DMT1 deficiency leads to an impaired erythroid differentiation hallmarked by accumulation of immature forms of erythroblast which also showed increased rate of apoptosis. For human samples we observed suppression of colony-forming capacity of erythroid progenitors that can be corrected by the addition of iron saturated chelate Fe-SIH. Later we proved this result also for mk/mk progenitors and showed reduced number of mk/mk CFU-E (164±25 vs. 283±50) and BFU-E (9±4 vs. 22±5) colonies in comparison to the colonies of wild-type (wt) mice and improvement of the colony growth with Fe-SIH. In our following studies we focused on mature erythrocytes, the last stage of erythroid differentiation that has not been analyzed yet. We first determined the in vivo half-life of red blood cells (RBC). Isolated RBCs from mk/mk mice and wt controls were in vitro labeled with CFSE fluorescent dye and injected into the wt mice. The intensity of RBCs fluorescence was measured on the 1st, 7th, 10th, 14th, 19th, 26th and 30th day following the injection. We observed an accelerated clearance of CFSE-labeled mk/mk RBCs from circulating blood when compared to wt RBCs, which indicates increased destruction of DMT1-mutant erythrocytes in vivo. It is known, that mature RBCs retain the ability to undergo stress-induced death (eryptosis), characterized by their shrinkage, membrane blebbing and phosphatidylserine surface exposure. This process may be triggered by iron deficiency. To determine the involvement of eryptosis in mk/mk RBCs clearance, RBCs were exposed to different stress conditions in vitro. A significantly increased number of Annexin V-positive RBCs was detected for mk/mk RBCs when compared to wt RBCs after 5 and 7 hour exposure to hyperosmotic shock (400mM sucrose) and glucose depletion, respectively. These results indicate shortened life span of DMT1-mutant erythrocytes and their reduced ability to cope with stress. To unravel the possible underlying mechanisms we focus on two processes important for RBC survival; anti-oxidative defense and anaerobic glycolysis. We observed 1.5 to 2-fold higher activity of glutathione peroxidase, catalase and methemoglobin reductase and elevated levels of methemoglobin in mk/mk RBCs in comparison to wt RBCs, indicating increased oxidative stress in mk/mk RBCs. Increased activity of hexokinase (2.5 times) and pyruvatkinase (2.4 times) together with reduced ratio of ATP/ADP in mk/mk mice compared with wt mice (from 2.89±0.56 μmol/L to 1.71±0.49 μmol/L) shows enhanced demand for glycolytically derived ATP to maintain the stability of RBC membrane in mk/mk mice. Our analyzes suggest that DMT1 deficiency negatively affects metabolism and life span of mature erythrocytes; two other aspects of defective erythropoiesis contributing to the pathophysiology of the disease. Grant support Czech Grant Agency, grant No. P305/11/1745; Ministry of Health Czech Republic Grant No. NT11208 and Internal Grant of Palacky University Olomouc (LF_2013_010). Disclosures: No relevant conflicts of interest to declare.

scholarly journals Determination of the Interaction and Pharmacological Modulation of MCHR1 Signaling by C Terminus of MRAP2 Protein

2021 ◽  
Author(s):  
Meng Wang ◽  
Yue Zhai ◽  
Xiaowei Lei ◽  
Jing Xu ◽  
Bopei Jiang ◽  
...  
Keyword(s):  
Energy Homeostasis ◽  
Transmembrane Protein ◽  
Melanocortin Receptor ◽  
Pharmacological Modulation ◽  
C Terminus ◽  
Melanin Concentrating Hormone ◽  
The Central Nervous System

Abstract Background: Melanin concentrating hormone (MCH), an orexigenic neuropeptide, is primarily secreted by the hypothalamus and acts at its receptor, the melanin-concentrating hormone receptor 1 (MCHR1), to regulate energy homeostasis and body weight. The Melanocortin Receptor Accessory Protein 2 (MRAP2), a small single transmembrane protein broadly expressed in multiple tissues, has been defined as a vital endocrine pivot of five melanocortin receptors (MC1R-MC5R) and several other GPCRs in the regulation of central neuronal appetite and peripheral energy homeostasis. However, the regulatory and relationship between MCHR1 and MRAP2 is unknown.Results: In this study, we show that MRAP2 interacts with MCHR1 and suppresses MCHR1 signaling in vitro. We also identified the C-terminal domains of MRAP2 protein required for pharmacological modulation of intracellular Ca2+ cascades and membrane transport.Conclusions: These findings elucidated the broad regulatory profile of MRAP2 protein in the central nervous system and may provide implications for the modulation of central MCHR1 function in vivo.

scholarly journals Determination of in Vitro Antioxidant Enzyme Capacity and Oxidative Stress Levels in Mazı Meşesi (Quercus infectoria)

2021 ◽  
Vol 9 (4) ◽  
pp. 814-817
Author(s):  
İlter Demirhan ◽  
Büşra Çitil ◽  
Mehmet Özyurt ◽  
Meltem Güngör ◽  
Erkan Öner ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Superoxide Dismutase ◽  
Antioxidant Capacity ◽  
Antioxidant Enzyme ◽  
Antioxidant Enzyme Activities ◽  
Spectrophotometric Methods ◽  
Significant Difference ◽  
Quercus Infectoria

South East Anatolia Region has a large genetic plant diversity due to its physical and different climatic charesteristics. These plants are potential sources of antioxidants that prevent oxidative stress caused by oxygen and photons. In recent years, it has become important to study the antioxidant capacity of many molecules found naturally in foods and biological systems. The reason for this is that it is believed that when the consumption of food rich in antioxidants is increased, the risk of developing different degenerative diseases will be reduced. In this study, it was aimed to measure the antoxidant capacity of Quercus infectoria, G.olivier gal seeds grown in Southeastern Anatolia. Q. infectoria gal seeds from Sanlıurfa province were used in our study. Q. infectoria gal seeds were extracted with water, ethanol and methanol and then antioxidant enzyme activities (catalase and superoxide dismutase) and malondialdehyde levels, which are indicators of oxidative stress were determined by spectrophotometric methods. It was found that the antioxidant capacity (catalase and superoxide dismutase activities) of extracts obtained from ethanol and methanol were higher and their malondialdehyde levels were statistically lower than those obtained from water. However, it was determined that there was no statistically significant difference between the antioxidant capacity and malondialdehyde levels of the extracts obtained from methanol compared to the extracts obtained from ethanol. It has been concluded that Q. infectoria gal seed has a effective antioxidant effect. In addition, it was observed that extracts obtained from ethanol and methanol have higher antioxidant capacity than extracts obtained from water.

scholarly journals Individualized management of genetic diversity in Niemann-Pick C1 through modulation of the Hsp70 chaperone system

2019 ◽  
Vol 29 (1) ◽  
pp. 1-19 ◽  
Author(s):  
Chao Wang ◽  
Samantha M Scott ◽  
Shuhong Sun ◽  
Pei Zhao ◽  
Darren M Hutt ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Transmembrane Protein ◽  
Genetic Disorder ◽  
Cholesterol Homeostasis ◽  
Spatial Covariance ◽  
Spatial Profiling ◽  
Hsp70 Chaperone ◽  
Niemann Pick ◽  
Chaperone Complex

Abstract Genetic diversity provides a rich repository for understanding the role of proteostasis in the management of the protein fold in human biology. Failure in proteostasis can trigger multiple disease states, affecting both human health and lifespan. Niemann-Pick C1 (NPC1) disease is a rare genetic disorder triggered by mutations in NPC1, a multi-spanning transmembrane protein that is trafficked through the exocytic pathway to late endosomes (LE) and lysosomes (Ly) (LE/Ly) to globally manage cholesterol homeostasis. Defects triggered by >300 NPC1 variants found in the human population inhibit export of NPC1 protein from the endoplasmic reticulum (ER) and/or function in downstream LE/Ly, leading to cholesterol accumulation and onset of neurodegeneration in childhood. We now show that the allosteric inhibitor JG98, that targets the cytosolic Hsp70 chaperone/co-chaperone complex, can significantly improve the trafficking and post-ER protein level of diverse NPC1 variants. Using a new approach to model genetic diversity in human disease, referred to as variation spatial profiling, we show quantitatively how JG98 alters the Hsp70 chaperone/co-chaperone system to adjust the spatial covariance (SCV) tolerance and set-points on an amino acid residue-by-residue basis in NPC1 to differentially regulate variant trafficking, stability, and cholesterol homeostasis, results consistent with the role of BCL2-associated athanogene family co-chaperones in managing the folding status of NPC1 variants. We propose that targeting the cytosolic Hsp70 system by allosteric regulation of its chaperone/co-chaperone based client relationships can be used to adjust the SCV tolerance of proteostasis buffering capacity to provide an approach to mitigate systemic and neurological disease in the NPC1 population.

scholarly journals Determination of the Interaction and Pharmacological Modulation of MCHR1 Signaling by C Terminus of MRAP2 Protein

2021 ◽  
Author(s):  
Meng Wang ◽  
Yue Zhai ◽  
Xiaowei Lei ◽  
Jing Xu ◽  
Bopei Jiang ◽  
...  
Keyword(s):  
Energy Homeostasis ◽  
Transmembrane Protein ◽  
Melanocortin Receptor ◽  
Pharmacological Modulation ◽  
C Terminus ◽  
Melanin Concentrating Hormone ◽  
The Central Nervous System

Abstract Background: Melanin concentrating hormone (MCH), an orexigenic neuropeptide, is primarily secreted by the hypothalamus and acts at its receptor, the melanin-concentrating hormone receptor 1 (MCHR1), to regulate energy homeostasis and body weight. The Melanocortin Receptor Accessory Protein 2 (MRAP2), a small single transmembrane protein broadly expressed in multiple tissues, has been defined as a vital endocrine pivot of five melanocortin receptors (MC1R-MC5R) and several other GPCRs in the regulation of central neuronal appetite and peripheral energy homeostasis. However, the regulatory and relationship between MCHR1 and MRAP2 is unknown.Results: In this study, we show that MRAP2 interacts with MCHR1 and suppresses MCHR1 signaling in vitro. We also identified the C-terminal domains of MRAP2 protein required for pharmacological modulation of intracellular Ca2+ cascades and membrane transport. Conclusions: These findings elucidated the broad regulatory profile of MRAP2 protein in the central nervous system and may provide implications for the modulation of central MCHR1 function in vivo.

scholarly journals Study on the Influence of Free Radicals and Oxidative Stress on Peptic Ulcers

2019 ◽  
Vol 70 (9) ◽  
pp. 3254-3257
Author(s):  
Germaine Savoiu Balint ◽  
Emeric Toth ◽  
Mihaiela Andoni ◽  
Ioan Demeter ◽  
Claudia Borza ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gastric Ulcer ◽  
Gastric Carcinoma ◽  
Organ Bath ◽  
Vascular Endothelial ◽  
Peptic Ulcers ◽  
Antioxidant Treatment ◽  
And Oxidative Stress

It can be observed that oxidative stress initiates and aggravates many diseases, including peptic ulcers and gastric carcinoma. An increase in rat mucosal glandular lipid peroxidation (LPO) and superoxide dismutase (SOD) and a decrease in catalase (CAT) levels in gastric ulceration induced by cold retention stress were observed, whereas in patients with ulcerated clinical peptic and gastric carcinoma LPO serum is associated with a decrease in SOD and CAT. It was intended to determine the parameters of oxidative stress in the blood and brain in rats after induction of gastric ulcer, the effect of antioxidant treatment on these parameters and on the appearance of gastric ulcer, determination of correlation between oxidative stress and severity of gastric ulcer in rats and also evaluation of vascular endothelial function by in vitro studies in the organ bath, from rat aortic rings with gastric ulcer vs. normal and others under treatment vs. untreated.

scholarly journals Achieving the Balance between ROS and Antioxidants: When to Use the Synthetic Antioxidants

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Borut Poljsak ◽  
Dušan Šuput ◽  
Irina Milisav
Keyword(s):  
Oxidative Stress ◽  
Cell Damage ◽  
Accurate Determination ◽  
Cellular Aging ◽  
Free Radical Damage ◽  
Ros Formation ◽  
Antioxidative Stress ◽  
Antioxidant Supplements

Free radical damage is linked to formation of many degenerative diseases, including cancer, cardiovascular disease, cataracts, and aging. Excessive reactive oxygen species (ROS) formation can induce oxidative stress, leading to cell damage that can culminate in cell death. Therefore, cells have antioxidant networks to scavenge excessively produced ROS. The balance between the production and scavenging of ROS leads to homeostasis in general; however, the balance is somehow shifted towards the formation of free radicals, which results in accumulated cell damage in time. Antioxidants can attenuate the damaging effects of ROSin vitroand delay many events that contribute to cellular aging. The use of multivitamin/mineral supplements (MVMs) has grown rapidly over the past decades. Some recent studies demonstrated no effect of antioxidant therapy; sometimes the intake of antioxidants even increased mortality. Oxidative stress is damaging and beneficial for the organism, as some ROS are signaling molecules in cellular signaling pathways. Lowering the levels of oxidative stress by antioxidant supplements is not beneficial in such cases. The balance between ROS and antioxidants is optimal, as both extremes, oxidative and antioxidative stress, are damaging. Therefore, there is a need for accurate determination of individual's oxidative stress levels before prescribing the supplement antioxidants.

Sign in / Sign up

Export Citation Format

Share Document