scholarly journals Neurotoxicity of Unconjugated Bilirubin in Neonatal Hypoxic-Ischemic Brain Injury in vitro

2021 ◽  
Vol 9 ◽  
Author(s):  
Carlo Dani ◽  
Simone Pratesi ◽  
Guido Mannaioni ◽  
Elisabetta Gerace

Background: The pathophysiology of bilirubin neurotoxicity in course of hypoxic–ischemic encephalopathy (HIE) in term and preterm infants is still poorly understood. We hypothesized that oxidative stress may be a common mechanism that link hyperbilirubinemia and HIE.Objectives: The objective of the present study was to evaluate whether unconjugated bilirubin (UCB) may enhance the HI brain injury by increasing oxidative stress and to test pioglitazone and allopurinol as new antioxidant therapeutic drugs in vitro.Methods: The effects of UCB were tested on organotypic hippocampal slices subjected to 30 min oxygen-glucose deprivation (OGD), used as in vitro model of HIE. The experiments were performed on mature (14 days in culture) and immature (7 days in culture) slices, to mimic the brains of term and preterm infants, respectively. Mature and immature slices were exposed to UCB, human serum albumin (HSA), pioglitazone, and/or allopurinol for 24 h, immediately after 30 min OGD. Neuronal injury was assessed using propidium iodide (PI) fluorescence. ROS formation was quantified by using the 2′,7′-dichlorodihydrofluorescein diacetate (DCF-DA) method.Results: In mature slices, we found that the neurotoxicity, as well as oxidative stress, induced by OGD were enhanced by UCB. HSA significantly prevented UCB-increased neurotoxicity, but had a slight reduction on ROS production. Allopurinol, but not pioglitazone, significantly reduced UCB-increased neurotoxicity induced by OGD. In immature slices exposed to OGD, no increase of neuronal death was observed, whereas oxidative stress was detected after UCB exposure. HSA, pioglitazone and allopurinol have no protective effects on both OGD-induced neuronal death and on UCB-induced oxidative stress. For this reason, UCB, pioglitazone and allopurinol was also tested on ischemic preconditioning protocol. We found that UCB abolished the neuroprotection induced by preconditioning and increased oxidative stress. These effects were restored by allopurinol but not pioglitazone.Conclusions: UCB characterized a different path of neuronal damage and oxidative stress in mature and immature hippocampal slice model of HIE. Management of hyperbilirubinemia in a complex pathological condition, such as HIE and hyperbilirubinemia, should be very careful. Allopurinol could deserve attention as a novel pharmacological intervention for hyperbilirubinemia and HIE.

2021 ◽  
Vol 22 (4) ◽  
pp. 1514 ◽  
Author(s):  
Akihiro Yachie

Since Yachie et al. reported the first description of human heme oxygenase (HO)-1 deficiency more than 20 years ago, few additional human cases have been reported in the literature. A detailed analysis of the first human case of HO-1 deficiency revealed that HO-1 is involved in the protection of multiple tissues and organs from oxidative stress and excessive inflammatory reactions, through the release of multiple molecules with anti-oxidative stress and anti-inflammatory functions. HO-1 production is induced in vivo within selected cell types, including renal tubular epithelium, hepatic Kupffer cells, vascular endothelium, and monocytes/macrophages, suggesting that HO-1 plays critical roles in these cells. In vivo and in vitro studies have indicated that impaired HO-1 production results in progressive monocyte dysfunction, unregulated macrophage activation and endothelial cell dysfunction, leading to catastrophic systemic inflammatory response syndrome. Data from reported human cases of HO-1 deficiency and numerous studies using animal models suggest that HO-1 plays critical roles in various clinical settings involving excessive oxidative stress and inflammation. In this regard, therapy to induce HO-1 production by pharmacological intervention represents a promising novel strategy to control inflammatory diseases.


2015 ◽  
Vol 69 (3-4) ◽  
pp. 245-258
Author(s):  
Dijana Topalovic ◽  
Lada Zivkovic ◽  
Ninoslav Djelic ◽  
Vladan Bajic ◽  
Andrea Cabarkapa ◽  
...  

Hormones are cellular products involved in the regulation of a large number of processes in living systems, and which by their actions affect the growth, function and metabolism of cells. Considering that hormones are compounds normally present in the organism, it is important to determine if they can, under certain circumstances, lead to genetic changes in the hereditary material. Numerous experimental studies in vitro and in vivo in different systems, from bacteria to mammals, dealt with the mutagenic and genotoxic effects of hormones. This work presents an overview of the research on genotoxic effects of non?steroidal hormones, although possible changes of genetic material under their influence have not still been known enough, and moreover, investigations on their genotoxic influence have given conflicting results. The study results show that mechanisms of genotoxic effect of nonsteroidal hormones are manifested through the increase of oxidative stress by arising reactive oxygen species. A common mechanism of ROS occurence in thyroid hormones and catecholamines is through metabolic oxidation of their phenolic groups. Manifestation of insulin genotoxic effect is based on production of ROS by activation of NADPH isophorms, while testing oxytocin showed absence of genotoxic effect. Considering that the investigations on genotoxicity of nonsteroidal hormones demonstrated both positive and negative results, the explanation of this discordance involve limitations of test systems themselves, different cell types or biological species used in the experiments, different level of reactivity in vitro and in vivo, as well as possible variations in a tissue-specific expression. Integrated, the provided data contribute to better understanding of genotoxic effect of nonsteroidal hormones and point out to the role and mode of action of these hormones in the process of occurring of effects caused by oxidative stress.


2011 ◽  
Vol 4 (1) ◽  
pp. 20-26 ◽  
Author(s):  
Ružena Sotníková ◽  
Jana Nedelčevová ◽  
Jana Navarová ◽  
Viera Nosáľová ◽  
Katarína Drábiková ◽  
...  

Protection of the vascular endothelium in experimental situationsOne of the factors proposed as mediators of vascular dysfunction observed in diabetes is the increased generation of reactive oxygen species (ROS). This provides support for the use of antioxidants as early and appropriate pharmacological intervention in the development of late diabetic complications. In streptozotocin (STZ)-induced diabetes in rats we observed endothelial dysfuction manifested by reduced endothelium-dependent response to acetylcholine of the superior mesenteric artery (SMA) and aorta, as well as by increased endothelaemia. Changes in endothelium-dependent relaxation of SMA were induced by injury of the nitric oxide radical (·NO)-signalling pathway since the endothelium-derived hyperpolarising factor (EDHF)-component of relaxation was not impaired by diabetes. The endothelial dysfunction was accompanied by decreased ·NO bioavailabity as a consequence of reduced activity of eNOS rather than its reduced expression. The results obtained using the chemiluminiscence method (CL) argue for increased oxidative stress and increased ROS production. The enzyme NAD(P)H-oxidase problably participates in ROS production in the later phases of diabetes. Oxidative stress was also connected with decreased levels of reduced glutathione (GSH) in the early phase of diabetes. After 10 weeks of diabetes, adaptational mechanisms probably took place because GSH levels were not changed compared to controls. Antioxidant properties of SMe1EC2 foundin vitrowere partly confirmedin vivo.Administration of SMe1EC2 protected endothelial function. It significantly decreased endothelaemia of diabetic rats and improved endothelium-dependent relaxation of arteries, slightly decreased ROS-production and increased bioavailability of ·NO in the aorta. Further studies with higher doses of SMe1EC2 may clarify the mechanism of its endothelium-protective effectin vivo.


2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yongpan Huang ◽  
Xinliang Li ◽  
Xi Zhang ◽  
Jiayu Tang

Oxymatrine (OMT) is the major quinolizidine alkaloid extracted from the root of Sophora flavescens Ait and has been shown to exhibit a diverse range of pharmacological properties. The aim of the present study was to investigate the role of OMT in diabetic brain injury in vivo and in vitro. Diabetic rats were induced by intraperitoneal injection of a single dose of 65 mg/kg streptozotocin (STZ) and fed a high-fat and high-cholesterol diet. Memory function was assessed using a Morris water maze test. A SH-SY5Y cell injury model was induced by incubation with glucose (30 mM/l) to simulate damage in vitro. The serum fasting blood glucose, insulin, serum S100B, malondialdehyde (MDA), and superoxide dismutase (SOD) levels were analyzed using commercial kits. Morphological changes were observed using Nissl staining and electron microscopy. Cell apoptosis was assessed using Hoechst staining and TUNEL staining. NADPH oxidase (NOX) and caspase-3 activities were determined. The effects of NOX2 and NOX4 knockdown were assessed using small interfering RNA. The expression levels of NOX1, NOX2, and NOX4 were detected using reverse transcription-quantitative PCR and western blotting, and the levels of caspase-3 were detected using western blotting. The diabetic rats exhibited significantly increased plasma glucose, insulin, reactive oxygen species (ROS), S-100B, and MDA levels and decreased SOD levels. Memory function was determined by assessing the percentage of time spent in the target quadrant, the number of times the platform was crossed, escape latency, and mean path length and was found to be significantly reduced in the diabetic rats. Hyperglycemia resulted in notable brain injury, including histological changes and apoptosis in the cortex and hippocampus. The expression levels of NOX2 and NOX4 were significantly upregulated at the protein and mRNA levels, and NOX1 expression was not altered in the diabetic rats. NOX and caspase-3 activities were increased, and caspase-3 expression was upregulated in the brain tissue of diabetic rats. OMT treatment dose-dependently reversed behavioral, biochemical, and molecular changes in the diabetic rats. In vitro, high glucose resulted in increases in reactive oxygen species (ROS), MDA levels, apoptosis, and the expressions of NOX2, NOX4, and caspase-3. siRNA-mediated knockdown of NOX2 and NOX4 decreased NOX2 and NOX4 expression levels, respectively, and reduced ROS levels and apoptosis. The results of the present study suggest that OMT alleviates diabetes-associated cognitive decline, oxidative stress, and apoptosis via NOX2 and NOX4 inhibition.


2020 ◽  
Vol 72 (6) ◽  
pp. 1579-1592
Author(s):  
Agata Ciechanowska ◽  
Katarzyna Popiolek-Barczyk ◽  
Katarzyna Ciapała ◽  
Katarzyna Pawlik ◽  
Marco Oggioni ◽  
...  

Abstract Background Every year, millions of people suffer from various forms of traumatic brain injury (TBI), and new approaches with therapeutic potential are required. Although chemokines are known to be involved in brain injury, the importance of X-C motif chemokine ligand 1 (XCL1) and its receptors, X-C motif chemokine receptor 1 (XCR1) and alpha-9 integrin (ITGA9), in the progression of TBI remain unknown. Methods Using RT-qPCR/Western blot/ELISA techniques, changes in the mRNA/protein levels of XCL1 and its two receptors, in brain areas at different time points were measured in a mouse model of TBI. Moreover, their cellular origin and possible changes in expression were evaluated in primary glial cell cultures. Results Studies revealed the spatiotemporal upregulation of the mRNA expression of XCL1, XCR1 and ITGA9 in all the examined brain areas (cortex, thalamus, and hippocampus) and at most of the evaluated stages after brain injury (24 h; 4, 7 days; 2, 5 weeks), except for ITGA9 in the thalamus. Moreover, changes in XCL1 protein levels occurred in all the studied brain structures; the strongest upregulation was observed 24 h after trauma. Our in vitro experiments proved that primary murine microglial and astroglial cells expressed XCR1 and ITGA9, however they seemed not to be a main source of XCL1. Conclusions These findings indicate that the XCL1/XCR1 and XCL1/ITGA9 axes may participate in the development of TBI. The XCL1 can be considered as one of the triggers of secondary injury, therefore XCR1 and ITGA9 may be important targets for pharmacological intervention after traumatic brain injury. Graphic abstract


2019 ◽  
Vol 8 (5) ◽  
pp. 641-653 ◽  
Author(s):  
Jinbao Gao ◽  
Yunjun Li ◽  
Wende Li ◽  
Haijiang Wang

Abstract Neuronal death caused by inflammatory cytokine-mediated neuroinflammation is being extensively explored. Thioredoxin reductase (TrxR) 2 is a novel mediator of inflammation response. In the current study, we focus on the mechanisms of TrxR2 overexpression in inflammation-mediated neuronal death. LPS was used to induce neuroinflammation in N2a cells in vitro. Adenovirus-loaded TrxR2 was transfected into N2a cells to up-regulate TrxR2 expression. Then, cell viability was determined via MTT assay and TUNEL assay. Apoptosis was measured via western blotting and ELISA. Oxidative stress was detected via ELISA and flow cytometry. A pathway inhibitor was used to verify the role of the Akt–Parkin pathway in the LPS-mediated N2a cell death in the presence of TrxR2 overexpression. With the help of immunofluorescence assay and western blotting, we found that TrxR2 expression was significantly reduced in response to LPS treatment, and this effect was associated with N2a cell death via apoptosis. At the molecular level, TrxR2 overexpression elevated the activity of the Akt–Parkin pathway, as evidenced by the increased expression of p-Akt and Parkin. Interestingly, inhibition of the Akt–Parkin pathway abolished the regulatory effect of TrxR2 on LPS-treated N2a cells, as evidenced by the decreased cell viability and increased apoptotic ratio. Besides, TrxR2 overexpression also reduced oxidative stress, inflammation factor transcription and mitochondrial apoptosis. However, inhibition of Akt–Parkin axis abrogated the protective effects of TrxR2 on redox balance, mitochondrial performance and cell survival. LPS-mediated neuronal death was linked to a drop in TrxR2 overexpression and the inactivation of the Akt–Parkin pathway. Overexpression of TrxR2 sustained mitochondrial function, inhibited oxidative stress, repressed inflammation response, and blocked mitochondrial apoptosis, finally sending a pro-survival signal for the N2a cells in the setting of LPS-mediated inflammation environment.


2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Kazuyuki Miyamoto ◽  
Hirokazu Ohtaki ◽  
Kenji Dohi ◽  
Tomomi Tsumuraya ◽  
Dandan Song ◽  
...  

Traumatic brain injury (TBI) is a major cause of death and disability in young people. No effective therapy is available to ameliorate its damaging effects. Our aim was to investigate the optimal therapeutic time window of edaravone, a free radical scavenger which is currently used in Japan. We also determined the temporal profile of reactive oxygen species (ROS) production, oxidative stress, and neuronal death. Male C57Bl/6 mice were subjected to a controlled cortical impact (CCI). Edaravone (3.0 mg/kg), or vehicle, was administered intravenously at 0, 3, or 6 hours following CCI. The production of superoxide radicals (O2∙-) as a marker of ROS, of nitrotyrosine (NT) as an indicator of oxidative stress, and neuronal death were measured for 24 hours following CCI. Superoxide radical production was clearly evident 3 hours after CCI, with oxidative stress and neuronal cell death becoming apparent after 6 hours. Edaravone administration after CCI resulted in a significant reduction in the injury volume and oxidative stress, particularly at the 3-hour time point. Moreover, the greatest decrease inO2∙-levels was observed when edaravone was administered 3 hours following CCI. These findings suggest that edaravone could prove clinically useful to ameliorate the devastating effects of TBI.


Stroke ◽  
2011 ◽  
Vol 42 (12) ◽  
pp. 3587-3593 ◽  
Author(s):  
Fan Zhao ◽  
Ya Hua ◽  
Yangdong He ◽  
Richard F. Keep ◽  
Guohua Xi

Background and Purpose— Brain iron overload plays a detrimental role in brain injury after intracerebral hemorrhage (ICH). A recent study found that minocycline acts as an iron chelator and reduces iron-induced neuronal death in vitro. The present study investigated if minocycline reduces iron overload after ICH and iron-induced brain injury in vivo. Methods— This study was divided into 4 parts: (1) rats with different sizes of ICH were euthanized 3 days later for serum total iron and brain edema determination; (2) rats had an ICH treated with minocycline or vehicle. Serum iron, brain iron, and brain iron handling proteins were measured; (3) rats had an intracaudate injection of saline, iron, iron+minocycline, or iron+macrophage/microglia inhibitory factor and were used for brain edema and neuronal death measurements; and (4) rats had an intracaudate injection of iron and were treated with minocycline. The brains were used for edema measurement. Results— After ICH, serum total iron and brain nonheme iron increased and these changes were reduced by minocycline treatment. Minocycline also reduced ICH-induced upregulation of brain iron handling proteins and neuronal death. Intracaudate injection of iron caused brain edema, blood–brain barrier leakage, and brain cell death, all of which were significantly reduced by coinjection with minocycline. Conclusions— The current study found that minocycline reduces iron overload after ICH and iron-induced brain injury. It is also well known minocycline is an inhibitor of microglial activation. Minocycline may be very useful for patients with ICH because both iron accumulation and microglia activation contribute to brain damage after ICH.


Author(s):  
Jining Jia ◽  
Qin Li ◽  
Qianyi Sun ◽  
Nan Yang ◽  
Kangni Chen ◽  
...  

ABSTRACTBackground and PurposeRepetitive epileptic seizures trigger massive neuronal death. Therefore, neuroprotection plays a role in preventing neuronal death and inversely suppresses seizure generation. Additionally, some studies have shown ferroptosis, featured by lipid peroxidation (a dominant form of oxidative stress in the brain), is of paramount importance in epileptic seizures. Lapatinib can play a first-line anti-tumor role by targeting oxidative stress and a recent work illustrates the improvement of encephalomyelitis in rodent models after lapatinib treatment. We hypothesize whether lapatinib can protect against ferroptosis in epileptic seizures via regulating lipid peroxidation.Experimental ApproachThe epileptic behavior of the mice was recorded after intracranial injection of KA. Western blot and RT-qPCR were used to detect the protein expression of 4-hydroxynonenal (4-HNE) and glutathione peroxidase 4 (GPX4) and the mRNA expression of prostaglandin endoperoxide synthase 2 (PTGS2) in vivo and in vitro. The level of lipid reactive oxygen species (lipid ROS) in cells pretreated with lapatinib was analyzed by flow cytometry.Key ResultsLapatinib remarkably prevented KA-induced epileptic seizures in mice and ferroptosis was involved in the neuroprotection of lapatinib. Compared with the model group, western blot showed that lapatinib significantly upregulated the levels of GPX4. In the ferroptotic cell death model, lapatinib exerted neuroprotection via up-regulating GPX4. Treatment with Ras-selective lethal small molecule 3 (RSL3), a selective GPX4 inhibitor abrogated its anti-ferroptotic potential.Conclusions and ImplicationsThese results illustrated that lapatinib has neuroprotective potential against KA-triggered epileptic seizures via suppressing GPX4-dependent ferroptosis.What is already knownActivation of ferroptosis occurs in epileptic seizures.What this study addsLapatinib protects brain against epileptic seizures via blocking ferroptosis.GPX4-dependent ferroptosis is involved in the neuroprotection of lapatinib.What is the clinical significanceInhibition of ferroptosis by lapatinib represents a potential neuroprotective strategy for epileptic patients.


Cells ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1383 ◽  
Author(s):  
John Papaconstantinou

The ASK1-signalosome→p38 MAPK and SAPK/JNK signaling networks promote senescence (in vitro) and aging (in vivo, animal models and human cohorts) in response to oxidative stress and inflammation. These networks contribute to the promotion of age-associated cardiovascular diseases of oxidative stress and inflammation. Furthermore, their inhibition delays the onset of these cardiovascular diseases as well as senescence and aging. In this review we focus on whether the (a) ASK1-signalosome, a major center of distribution of reactive oxygen species (ROS)-mediated stress signals, plays a role in the promotion of cardiovascular diseases of oxidative stress and inflammation; (b) The ASK1-signalosome links ROS signals generated by dysfunctional mitochondrial electron transport chain complexes to the p38 MAPK stress response pathway; (c) the pathway contributes to the sensitivity and vulnerability of aged tissues to diseases of oxidative stress; and (d) the importance of inhibitors of these pathways to the development of cardioprotection and pharmaceutical interventions. We propose that the ASK1-signalosome regulates the progression of cardiovascular diseases. The resultant attenuation of the physiological characteristics of cardiomyopathies and aging by inhibition of the ASK1-signalosome network lends support to this conclusion. Importantly the ROS-mediated activation of the ASK1-signalosome p38 MAPK pathway suggests it is a major center of dissemination of the ROS signals that promote senescence, aging and cardiovascular diseases. Pharmacological intervention is, therefore, feasible through the continued identification of potent, non-toxic small molecule inhibitors of either ASK1 or p38 MAPK activity. This is a fruitful future approach to the attenuation of physiological aspects of mammalian cardiomyopathies and aging.


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