scholarly journals Cortical cells are altered by factors including bone morphogenetic protein released from a placental barrier model under altered oxygenation

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Veronica H.L. Leinster ◽  
Thomas J. Phillips ◽  
Nicola Jones ◽  
Sharon Sanderson ◽  
Katja Simon ◽  
...  
Keyword(s):  
Bone Morphogenetic Proteins ◽  
Later Life ◽  
Placental Barrier ◽  
Cortical Cells ◽  
Foetal Development ◽  
Release Factors ◽  
Increased Risk ◽  
Vitro Model ◽  
Hypoxia Reoxygenation

Abstract Episodes of hypoxia and hypoxia/reoxygenation during foetal development have been associated with increased risk of neurodevelopmental conditions presenting in later life. The mechanism for this is not understood; however, several authors have suggested that the placenta plays an important role. Previously we found both placentas from a maternal hypoxia model and pre-eclamptic placentas from patients release factors lead to a loss of dendrite complexity in rodent neurons. Here to further explore the nature and origin of these secretions we exposed a simple in vitro model of the placental barrier, consisting of a barrier of human cytotrophoblasts, to hypoxia or hypoxia/reoxygenation. We then exposed cortical cultures from embryonic rat brains to the conditioned media (CM) from below these exposed barriers and examined changes in cell morphology, number, and receptor presentation. The barriers released factors that reduced dendrite and astrocyte process lengths, decreased GABAB1 staining, and increased astrocyte number. The changes in astrocytes required the presence of neurons and were prevented by inhibition of the SMAD pathway and by neutralising Bone Morphogenetic Proteins (BMPs) 2/4. Barriers exposed to hypoxia/reoxygenation also released factors that reduced dendrite lengths but increased GABAB1 staining. Both oxygen changes caused barriers to release factors that decreased GluN1, GABAAα1 staining and increased GluN3a staining. We find that hypoxia in particular will elicit the release of factors that increase astrocyte number and decrease process length as well as causing changes in the intensity of glutamate and GABA receptor staining. There is some evidence that BMPs are released and contribute to these changes.

scholarly journals Preeclamptic placentae release factors that damage neurons: implications for foetal programming of disease

2018 ◽  
Vol 2 (4) ◽  
Author(s):  
Hannah Scott ◽  
Tom J. Phillips ◽  
Greer C. Stuart ◽  
Mark F. Rogers ◽  
Bruno R. Steinkraus ◽  
...  
Keyword(s):  
Placental Tissue ◽  
Later Life ◽  
Prenatal Development ◽  
Autism Spectrum ◽  
Antioxidant Treatment ◽  
Cortical Cells ◽  
Release Factors ◽  
Foetal Programming ◽  
Signalling Molecules ◽  
Increased Risk

Prenatal development is a critical period for programming of neurological disease. Preeclampsia, a pregnancy complication involving oxidative stress in the placenta, has been associated with long-term health implications for the child, including an increased risk of developing schizophrenia and autism spectrum disorders in later life. To investigate if molecules released by the placenta may be important mediators in foetal programming of the brain, we analysed if placental tissue delivered from patients with preeclampsia secreted molecules that could affect cortical cells in culture. Application of culture medium conditioned by preeclamptic placentae to mixed cortical cultures caused changes in neurons and astrocytes that were related to key changes observed in brains of patients with schizophrenia and autism, including effects on dendrite lengths, astrocyte number as well as on levels of glutamate and γ-aminobutyric acid receptors. Treatment of the placental explants with an antioxidant prevented neuronal abnormalities. Furthermore, we identified that bidirectional communication between neurons and astrocytes, potentially via glutamate, is required to produce the effects of preeclamptic placenta medium on cortical cells. Analysis of possible signalling molecules in the placenta-conditioned medium showed that the secretion profile of extracellular microRNAs, small post-transcriptional regulators, was altered in preeclampsia and partially rescued by antioxidant treatment of the placental explants. Predicted targets of these differentially abundant microRNAs were linked to neurodevelopment and the placenta. The present study provides further evidence that the diseased placenta may release factors that damage cortical cells and suggests the possibility of targeted antioxidant treatment of the placenta to prevent neurodevelopmental disorders.

scholarly journals The use of an in-vitro batch fermentation (human colon) model for investigating mechanisms of TMA production from choline, l-carnitine and related precursors by the human gut microbiota

2021 ◽  
Author(s):  
Priscilla Day-Walsh ◽  
Emad Shehata ◽  
Shikha Saha ◽  
George M. Savva ◽  
Barbora Nemeckova ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Metabolic Diseases ◽  
Human Colon ◽  
Human Studies ◽  
Bacterial Strains ◽  
Increased Risk ◽  
Carnitine Metabolism ◽  
Registration Number ◽  
Vitro Model

Abstract Purpose Plasma trimethylamine-N-oxide (TMAO) levels have been shown to correlate with increased risk of metabolic diseases including cardiovascular diseases. TMAO exposure predominantly occurs as a consequence of gut microbiota-dependent trimethylamine (TMA) production from dietary substrates including choline, carnitine and betaine, which is then converted to TMAO in the liver. Reducing microbial TMA production is likely to be the most effective and sustainable approach to overcoming TMAO burden in humans. Current models for studying microbial TMA production have numerous weaknesses including the cost and length of human studies, differences in TMA(O) metabolism in animal models and the risk of failing to replicate multi-enzyme/multi-strain pathways when using isolated bacterial strains. The purpose of this research was to investigate TMA production from dietary precursors in an in-vitro model of the human colon. Methods TMA production from choline, l-carnitine, betaine and γ-butyrobetaine was studied over 24–48 h using an in-vitro human colon model with metabolite quantification performed using LC–MS. Results Choline was metabolised via the direct choline TMA-lyase route but not the indirect choline–betaine-TMA route, conversion of l-carnitine to TMA was slower than that of choline and involves the formation of the intermediate γ-BB, whereas the Rieske-type monooxygenase/reductase pathway for l-carnitine metabolism to TMA was negligible. The rate of TMA production from precursors was choline > carnitine > betaine > γ-BB. 3,3-Dimethyl-1-butanol (DMB) had no effect on the conversion of choline to TMA. Conclusion The metabolic routes for microbial TMA production in the colon model are consistent with observations from human studies. Thus, this model is suitable for studying gut microbiota metabolism of TMA and for screening potential therapeutic targets that aim to attenuate TMA production by the gut microbiota. Trial registration number NCT02653001 (http://www.clinicaltrials.gov), registered 12 Jan 2016.

An in vitro model of warm hypoxia–reoxygenation injury in human liver endothelial cells

2012 ◽  
Vol 178 (1) ◽  
pp. e35-e41 ◽  
Author(s):  
Neal R. Banga ◽  
K. Raj Prasad ◽  
J. Lance Burn ◽  
Shervanthi Homer-Vanniasinkam ◽  
Anne Graham
Keyword(s):  
Endothelial Cells ◽  
Human Liver ◽  
In Vitro Model ◽  
Reoxygenation Injury ◽  
Liver Endothelial Cells ◽  
Vitro Model ◽  
Hypoxia Reoxygenation

Xanthine oxidase produces O2-. in posthypoxic injury of renal epithelial cells

1992 ◽  
Vol 263 (2) ◽  
pp. F251-F255 ◽  
Author(s):  
E. L. Greene ◽  
M. S. Paller
Keyword(s):  
Epithelial Cells ◽  
Xanthine Oxidase ◽  
Superoxide Radical ◽  
Total Activity ◽  
Oxygen Free Radical ◽  
Radical Production ◽  
Ldh Release ◽  
Vitro Model ◽  
Hypoxia Reoxygenation

The hypothesis that posthypoxic renal injury is mediated by xanthine oxidase-derived oxygen free radical production was tested in an in vitro model of rat proximal tubule epithelial cells in primary culture subjected to 60 min of hypoxia and 30 min of reoxygenation. Hypoxia-reoxygenation-induced injury, measured as lactate dehydrogenase (LDH) release, was 54.0 +/- 7.1%. Inhibition of xanthine oxidase by 10(-4) M allopurinol attenuated injury (LDH release = 35.5 +/- 3.7%; P less than 0.01). Oxypurinol was similarly effective. Alternatively, cells were treated with 50 or 100 microM tungsten to inactivate xanthine oxidase. Tungsten prevented hypoxia-reoxygenation-induced superoxide radical production (basal = 97 +/- 8, hypoxia-reoxygenation = 172 +/- 12, and plus tungsten = 73 +/- 8 nmol/micrograms protein) and attenuated hypoxia-reoxygenation-induced injury (LDH release: basal = 18.8 +/- 3.0%, hypoxia-reoxygenation = 62.0 +/- 4.8%, plus 50 microM tungsten = 24.8 +/- 5.0%, and plus 100 microM tungsten = 6.0 +/- 0.7%). In addition, hypoxia and reoxygenation increased the ratio of xanthine oxidase to total activity (xanthine oxidase + xanthine dehydrogenase) from 73 to 100%. Therefore xanthine oxidase was responsible for hypoxia-reoxygenation-induced superoxide radical formation and hypoxia-reoxygenation-induced injury. Xanthine oxidase is likely to be the major source of oxygen free radicals during renal ischemia and reperfusion.

scholarly journals Octreotide ameliorates hypoxia/reoxygenation-induced cerebral infarction by inhibiting oxidative stress, inflammation and apoptosis, and via inhibition of TLR4/MyD88/NF-κB signaling pathway

2021 ◽  
Vol 20 (11) ◽  
pp. 2261-2266
Author(s):  
Yanbin Hou ◽  
Zhongze Lou ◽  
Yunxin Ji ◽  
Liemin Ruan ◽  
He Gao
Keyword(s):  
Oxidative Stress ◽  
Cerebral Infarction ◽  
Signaling Pathway ◽  
Control Group ◽  
N2a Cells ◽  
Tnf Α ◽  
Octreotide Treatment ◽  
Vitro Model ◽  
Hypoxia Reoxygenation

Purpose: To explore the effects of octreotide (OCT) on oxidative stress, inflammation and apoptosis in hypoxia/reoxygenation (H/R)-induced cerebral infarction.Methods: The in vitro model of cerebral infarction was established by treating N2A cells with hypoxia for 4 h and reoxygenation for 24 h. The viability of N2A cells was determined by CCK-8 assay. The cells were divided into 3 groups: control group, H/R group, and H/R+OCT group. The cells in H/R+OCT group were pretreated with OCT (60 ng/mL) before H/R treatment. The oxidative stress of N2A cells were assessed by determining the levels of superoxide dismutase (SOD), glutathione peroxidase (GSHPx), catalase (CAT), reactive oxygen species (ROS) and malondialdehyde (MDA). Inflammation of N2A cells was evaluated by evaluating the levels of TNF-α, IL-1β, IL-6, and IL-8, while the apoptosis of N2A cells was assessed by flow cytometry. Western blot analysis was used to determine the expression of Bcl-2, Bax, TLR4, MyD88, and NF-κB.Results: Octreotide treatment significantly reduced the level of oxidative stress. The inflammation of N2A cells caused by hypoxia/reoxygenation was inhibited by treatment with octreotide. Apoptosis of N2A cells was also inhibited by octreotide treatment. Hypoxia/reoxygenation activated TLR4/MyD88/NF-κB signaling pathway, while octreotide inhibits the activation of this pathway.Conclusion: The results reveal that octreotide inhibits hypoxia/reoxygenation-induced oxidative stress,as well as the inflammation, and apoptosis of N2A cells by inhibiting TLR4/MyD88/NF-κB signaling pathway. Thus, these findings may provide new insights into the treatment of cerebral infarction.

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