Selected Contribution: Hyperthermia-induced intestinal permeability and the role of oxidative and nitrosative stress

2002 ◽  
Vol 92 (4) ◽  
pp. 1750-1761 ◽  
Author(s):  
G. P. Lambert ◽  
C. V. Gisolfi ◽  
D. J. Berg ◽  
P. L. Moseley ◽  
L. W. Oberley ◽  
...  
Keyword(s):  
Heat Stress ◽  
Intestinal Permeability ◽  
Nitrosative Stress ◽  
Lipid Peroxidation Product ◽  
Intestinal Epithelial ◽  
Oxidative And Nitrosative Stress ◽  
Epithelial Damage

The purpose of this study was to characterize intestinal permeability changes over a range of physiologically relevant body temperatures in vivo and in vitro. Initially, FITC-dextran (4,000 Da), a large fluorescent molecule, was loaded into the small intestine of anesthetized rats. The rats were then maintained at ∼37°C or heated over 90 min to a core body temperature of ∼41, ∼41.5, or ∼42.5°C. Permeability was greater in the 42.5°C group compared with the 37, 41, or 41.5°C groups. Histological analysis revealed intestinal epithelial damage in heated groups. Everted intestinal sacs were then used to further characterize hyperthermia-induced intestinal permeability and to study the potential role of oxidative and nitrosative stress. Increased permeability to 4,000-Da FITC-dextran in both small intestinal and colonic sacs was observed at a temperature of 41.5–42°C compared with 37°C, along with widespread intestinal epithelial damage. Administration of antioxidant enzyme mimics or a nitric oxide synthase inhibitor did not reduce permeability due to heat stress, and tissue concentrations of a lipid peroxidation product were not altered by heat stress, suggesting that oxidative and nitrosative stress were not likely mediators of this phenomenon in vitro. In conclusion, hyperthermia produced increased permeability and marked intestinal epithelial damage both in vivo and in vitro, suggesting that thermal disruption of epithelial membranes contributes to the intestinal barrier dysfunction manifested with heat stress.

scholarly journals A Possible Novel Anti-Inflammatory Mechanism for the Pharmacological Prolyl Hydroxylase Inhibitor 3,4-Dihydroxybenzoate: Implications for Use as a Therapeutic for Parkinson’s Disease

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Shankar J. Chinta ◽  
Subramanian Rajagopalan ◽  
Abirami Ganesan ◽  
Julie K. Andersen
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Microglial Activation ◽  
Nitrosative Stress ◽  
Neurodegenerative Disorder ◽  
Oxidative And Nitrosative Stress ◽  
Prolyl Hydroxylases ◽  
Age Related

Parkinson’s disease (PD) is an age-related neurodegenerative disorder characterized in part by the preferential loss of nigrostriatal dopaminergic neurons. Although the precise etiology of PD is unknown, accumulating evidence suggests that PD involves microglial activation that exerts neurotoxic effects through production of proinflammatory cytokines and increased oxidative and nitrosative stress. Thus, controlling microglial activation has been suggested as a therapeutic target for combating PD. Previously we demonstrated that pharmacological inhibition of a class of enzymes known as prolyl hydroxylases via 3,4-dihydroxybenzoate administration protected against MPTP-induced neurotoxicity, however the exact mechanisms involved were not elucidated. Here we show that this may be due to DHB’s ability to inhibit microglial activation. DHB significantly attenuated LPS-mediated induction of nitric oxide synthase and pro-inflammatory cytokines in murine BV2 microglial cellsin vitroin conjunction with reduced ROS production and activation of NFκB and MAPK pathways possibly due to up-regulation of HO-1 levels. HO-1 inhibition partially abrogates LPS-mediated NFκB activity and subsequent NO induction.In vivo, DHB pre-treatment suppresses microglial activation elicited by MPTP treatment. Our results suggest that DHB’s neuroprotective properties could be due to its ability to dampen induction of microglial activation via induction of HO-1.

scholarly journals CCAAT/Enhancer-Binding Protein Homologous Protein (CHOP) Deficiency Attenuates Heatstroke-Induced Intestinal Injury

Inflammation ◽  
2021 ◽  
Author(s):  
Yan Cao ◽  
Maiying Fan ◽  
Yanfang Pei ◽  
Lei Su ◽  
Weiwei Xiao ◽  
...  
Keyword(s):  
Protein Expression ◽  
Er Stress ◽  
Intestinal Barrier ◽  
Intestinal Injury ◽  
Intestinal Epithelial ◽  
Barrier Dysfunction ◽  
Homologous Protein

Abstract The intestine is one of the main target organs involved in the pathological process of heatstroke. CCAAT/enhancer-binding protein homologous protein (CHOP) is involved in endoplasmic reticulum (ER) stress-induced apoptosis. This study aimed to explore the role of CHOP in heatstroke-induced intestinal injury and potential therapy. An in vitro heat stress (HS) model using Caco-2 cells was employed. We observed the role of CHOP in apoptosis-mediated intestinal epithelial cell injury secondary to HS by evaluating cell viability, lactate dehydrogenase release, apoptosis levels, and GRP78, PERK, ATF4, CHOP, Bcl-2, and BAX mRNA and protein expression. To further study the role of CHOP in HS-induced intestinal barrier dysfunction, we assessed transepithelial electrical resistance, paracellular tracer flux, ultrastructure of tight junctions, and protein expression of ZO-1 and occludin. Male wild-type mice and CHOP knockout mice were used for in vivo experiments. We evaluated serum d-lactate and diamine oxidase levels, histopathological changes, intestinal ultrastructure, and ZO-1 and occludin protein expression. HS activated the PERK-CHOP pathway and promoted apoptosis by upregulating BAX and downregulating Bcl-2; these effects were prevented by CHOP silencing. Intestinal epithelial barrier function was disrupted by HS in vitro and in vivo. CHOP silencing prevented intestinal barrier dysfunction in Caco-2 cells, whereas CHOP knockout mice exhibited decreased intestinal mucosal injury. The ER stress inhibitor 4-phenylbutyrate (4-PBA) prevented HS-induced intestinal injury in vitro and in vivo. This study indicated that CHOP deficiency attenuates heatstroke-induced intestinal injury and may contribute to the identification of a novel therapy against heatstroke associated with the ER stress pathway.

scholarly journals All-trans Retinoic Acid Counteracts Diarrhea and Inhibition of Downregulated in Adenoma Expression in Gut Inflammation

2019 ◽  
Vol 26 (4) ◽  
pp. 534-545 ◽  
Author(s):  
Shubha Priyamvada ◽  
Arivarasu N Anbazhagan ◽  
Anoop Kumar ◽  
Ishita Chatterjee ◽  
Alip Borthakur ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Intestinal Epithelial ◽  
Gut Inflammation ◽  
Trans Retinoic Acid ◽  
All Trans Retinoic Acid ◽  
Function Expression ◽  
Ifn Γ

Abstract Background Intestinal epithelial apical membrane Cl-/HCO3- exchanger DRA (downregulated in adenoma, SLC26A3) has emerged as an important therapeutic target for diarrhea, emphasizing the potential therapeutic role of agents that upregulate DRA. All-trans retinoic acid (ATRA), a key vitamin A metabolite, was earlier shown by us to stimulate DRA expression in intestinal epithelial cells. However, its role in modulating DRA in gut inflammation has not been investigated. Aims Our aim was to analyze the efficacy of ATRA in counteracting inflammation-induced decrease in DRA in vitro and in vivo. Methods Interferon-γ (IFN-γ)-treated Caco-2 cells and dextran sulfate sodium (DSS)-treated C57BL/6J mice served as in vitro and in vivo models of gut inflammation, respectively. The effect of ATRA on IFN-γ-mediated inhibition of DRA function, expression, and promoter activity were elucidated. In the DSS colitis model, diarrheal phenotype, cytokine response, in vivo imaging, myeloperoxidase activity, and DRA expression were measured in the distal colon. Results All-trans retinoic acid (10 μM, 24 h) abrogated IFN-γ (30 ng/mL, 24 h)-induced decrease in DRA function, expression, and promoter activity in Caco-2 cells. All-trans retinoic acid altered IFN-γ signaling via blocking IFN-γ-induced tyrosine phosphorylation of STAT-1. All-trans retinoic acid cotreatment (1 mg/kg BW, i.p. daily) of DSS-treated mice (3% in drinking water for 7 days) alleviated colitis-associated weight loss, diarrheal phenotype, and induction of IL-1β and CXCL1 and a decrease in DRA mRNA and protein levels in the colon. Conclusion Our data showing upregulation of DRA under normal and inflammatory conditions by ATRA demonstrate a novel role of this micronutrient in alleviating IBD-associated diarrhea.

scholarly journals Occludin regulates macromolecule flux across the intestinal epithelial tight junction barrier

2011 ◽  
Vol 300 (6) ◽  
pp. G1054-G1064 ◽  
Author(s):  
Rana Al-Sadi ◽  
Khaldun Khatib ◽  
Shuhong Guo ◽  
Dongmei Ye ◽  
Moustafa Youssef ◽  
...  
Keyword(s):  
Tight Junction ◽  
Intestinal Permeability ◽  
Transepithelial Resistance ◽  
Intestinal Epithelial ◽  
Knock Down ◽  
Large Channel ◽  
Epithelial Tight Junction ◽  
Mouse Intestine

Defective intestinal epithelial tight junction (TJ) barrier has been shown to be an important pathogenic factor contributing to the development of intestinal inflammation. The expression of occludin is markedly decreased in intestinal permeability disorders, including in Crohn's disease, ulcerative colitis, and celiac disease, suggesting that the decrease in occludin expression may play a role in the increase in intestinal permeability. The purpose of this study was to delineate the involvement of occludin in intestinal epithelial TJ barrier by selective knock down of occludin in in vitro (filter-grown Caco-2 monolayers) and in vivo (recycling perfusion of mouse intestine) intestinal epithelial models. Our results indicated that occludin small-interfering RNA (siRNA) transfection causes an increase in transepithelial flux of various-sized probes, including urea, mannitol, inulin, and dextran, across the Caco-2 monolayers, without affecting the transepithelial resistance. The increase in relative flux rate was progressively greater for larger-sized probes, indicating that occludin depletion has the greatest effect on the flux of large macromolecules. siRNA-induced knock down of occludin in mouse intestine in vivo also caused an increase in intestinal permeability to dextran but did not affect intestinal tissue transepithelial resistance. In conclusion, these results show for the first time that occludin depletion in intestinal epithelial cells in vitro and in vivo leads to a selective or preferential increase in macromolecule flux, suggesting that occludin plays a crucial role in the maintenance of TJ barrier through the large-channel TJ pathway, the pathway responsible for the macromolecule flux.

scholarly journals MMP-9-induced increase in intestinal epithelial tight permeability is mediated by p38 kinase signaling pathway activation of MLCK gene

2019 ◽  
Vol 316 (2) ◽  
pp. G278-G290 ◽  
Author(s):  
Rana Al-Sadi ◽  
Moustafa Youssef ◽  
Manmeet Rawat ◽  
Shuhong Guo ◽  
Karol Dokladny ◽  
...  
Keyword(s):  
Protein Expression ◽  
Intestinal Permeability ◽  
Barrier Function ◽  
Intestinal Inflammation ◽  
Gene Activity ◽  
Intestinal Epithelial ◽  
P38 Kinase ◽  
Kinase Signaling Pathway

Matrix metalloproteinase-9 (MMP-9) has been implicated as being an important pathogenic factor in inflammatory bowel disease (IBD). MMP-9 is markedly elevated in intestinal tissue of patients with IBD, and IBD patients have a defective intestinal tight-junction (TJ) barrier manifested by an increase in intestinal permeability. The loss of intestinal epithelial barrier function is an important contributing factor in the development and prolongation of intestinal inflammation; however, the role of MMP-9 in intestinal barrier function remains unclear. The purpose of this study was to investigate the effect of MMP-9 on the intestinal epithelial TJ barrier and to delineate the intracellular mechanisms involved by using in vitro (filter-grown Caco-2 monolayers) and in vivo (mouse small intestine recycling perfusion) systems. MMP-9 caused a time- and dose-dependent increase in Caco-2 TJ permeability. MMP-9 also caused an increase in myosin light-chain kinase (MLCK) gene activity, protein expression, and enzymatic activity. The pharmacological MLCK inhibition and siRNA-induced knockdown of MLCK inhibited the MMP-9-induced increase in Caco-2 TJ permeability. MMP-9 caused a rapid activation of the p38 kinase signaling pathway and inhibition of p38 kinase activity prevented the MMP-9-induced increase in MLCK gene activity and the increase in Caco-2 TJ permeability. MMP-9 also caused an increase in mouse intestinal permeability in vivo, which was accompanied by an increase in MLCK expression. The MMP-9-induced increase in mouse intestinal permeability was inhibited in MLCK-deficient mice. These data show for the first time that the MMP-9-induced increase in intestinal TJ permeability in vitro and in vivo was mediated by the p38 kinase signal transduction pathway upregulation of MLCK gene activity and that therapeutic targeting of these pathways can prevent the MMP-9-induced increase in intestinal TJ permeability. NEW & NOTEWORTHY MMP-9 is highly elevated in patients with IBD. IBD patients have compromised intestinal TJ barrier function manifested by an increase in intestinal permeability and intestinal inflammation. This study shows that MMP-9, at clinically achievable concentrations, causes an increase in intestinal TJ permeability in vitro and in vivo. In addition, a MMP-9-induced increase in intestinal TJ permeability was mediated by an increase in MLCK gene and protein expression via the p38 kinase pathway.

scholarly journals Inflammation-induced, 3′UTR-dependent translational inhibition of Hsp70 mRNA impairs intestinal homeostasis

2009 ◽  
Vol 296 (5) ◽  
pp. G1003-G1011 ◽  
Author(s):  
Shien Hu ◽  
Xiaorong Zhu ◽  
Joseph R. Triggs ◽  
Yun Tao ◽  
Yunwei Wang ◽  
...  
Keyword(s):  
Mucosal Inflammation ◽  
Luciferase Reporter ◽  
Hsp70 Expression ◽  
Intestinal Epithelial ◽  
Intestinal Homeostasis ◽  
Hsp70 Mrna ◽  
Translational Inhibition

Although the inducible heat shock protein 70 (Hsp70) is essential for maintaining intestinal homeostasis in colitis, it is translationally downregulated in inflamed colonic mucosa, paradoxically rendering the gut more susceptible to injury. We examined the basis for this process by analyzing the role of untranslated regions (UTR) of Hsp70 mRNA in inflammation-associated downregulation in vitro and in vivo. Using luciferase-reporter assays in young adult mouse intestinal epithelial cells, we determined that cytokine-induced translational inhibition of Hsp70 mRNA was mediated by the 3′UTR, but not 5′UTR. In vivo, dextran sodium sulfate (DSS) colitis was induced in wild-type (WT) and villin-promoter regulated “UTR-less” Hsp70 transgenic (TG) mice, the latter exhibiting intestinal epithelial-specific transgene expression. Progressive downregulation of colonic Hsp70 protein expression was observed in WT, but not in TG, mice with increasing severity of mucosal inflammation, confirming the essential role of the 3′UTR in mediating inflammation-associated downregulation of Hsp70. Hsp70 TG mice demonstrated significantly lower endoscopic and histological inflammation scores in DSS-induced colitis than WT. In conclusion, downregulation of Hsp70 expression in inflamed mucosa is mediated by translational inhibition requiring the 3′UTR, resulting in increased mucosal injury. By forcing intestinal epithelial-specific Hsp70 expression in vivo, the severity of experimentally induced colitis was significantly reduced.

scholarly journals S-allylmercaptocysteine scavenges hydroxyl radical and singlet oxygen in vitro and attenuates gentamicin-induced oxidative and nitrosative stress and renal damage in vivo

2004 ◽  
Vol 4 (1) ◽  
Author(s):  
José Pedraza-Chaverrí ◽  
Diana Barrera ◽  
Perla D Maldonado ◽  
Yolanda I Chirino ◽  
Norma A Macías-Ruvalcaba ◽  
...  
Keyword(s):  
Hydroxyl Radical ◽  
Singlet Oxygen ◽  
Renal Damage ◽  
Nitrosative Stress ◽  
Oxidative And Nitrosative Stress

scholarly journals Mechanisms of Herbal Nephroprotection in diabetes mellitus

2020 ◽  
Vol 2020 ◽  
pp. 1-31
Author(s):  
Dorin Dragoș ◽  
Maria Mirabela Manea ◽  
Delia Timofte ◽  
Dorin Ionescu
Keyword(s):  
Nitrosative Stress ◽  
Protective Action ◽  
Protective Mechanisms ◽  
Oxidative And Nitrosative Stress ◽  
Promising Alternative ◽  
Drug Classes ◽  
Mediators Of Inflammation ◽  
The Many

Diabetic nephropathy (DN) is a leading cause of kidney morbidity. Despite the multilayered complexity of the mechanisms involved in the pathogenesis of DN, the conventional treatment is limited to just a few drug classes fraught with the risk of adverse events, including the progression of renal dysfunction. Phytoceuticals offer a promising alternative as they act on the many-sidedness of DN pathophysiology, multitargeting its intricacies. This paper offers a review of the mechanisms underlying the protective action of these phytoagents, including boosting the antioxidant capabilities, suppression of inflammation, averting the proliferative and sclerosing/fibrosing events. The pathogenesis of DN is viewed as a continuum going from the original offense, high glucose, through the noxious products it generates (advanced glycation end-products, products of oxidative and nitrosative stress) and the signaling chains consequently brought into action, to the harmful mediators of inflammation, sclerosis, and proliferation that eventually lead to DN, despite the countervailing attempts of the protective mechanisms. Special attention was given to the various pathways involved, pointing out the ability of the phytoagents to hinder the deleterious ones (especially those leading to, driven by, or associated with TGF-β activation, SREBP, Smad, MAPK, PKC, NF-κB, NLRP3 inflammasome, and caspase), to promote the protective ones (PPAR-α, PPAR-γ, EP4/Gs/AC/cAMP, Nrf2, AMPK, and SIRT1), and to favorably modulate those with potentially dual effect (PI3K/Akt). Many phytomedicines have emerged as potentially useful out of in vitro and in vivo studies, but the scarcity of human trials seriously undermines their usage in the current clinical practice—an issue that stringently needs to be addressed.

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