scholarly journals Oxidative Stress: An Essential Factor in the Pathogenesis of Gastrointestinal Mucosal Diseases

2014 ◽  
Vol 94 (2) ◽  
pp. 329-354 ◽  
Author(s):  
Asima Bhattacharyya ◽  
Ranajoy Chattopadhyay ◽  
Sankar Mitra ◽  
Sheila E. Crowe

Reactive oxygen species (ROS) are generated as by-products of normal cellular metabolic activities. Superoxide dismutase, glutathione peroxidase, and catalase are the enzymes involved in protecting cells from the damaging effects of ROS. ROS are produced in response to ultraviolet radiation, cigarette smoking, alcohol, nonsteroidal anti-inflammatory drugs, ischemia-reperfusion injury, chronic infections, and inflammatory disorders. Disruption of normal cellular homeostasis by redox signaling may result in cardiovascular, neurodegenerative diseases and cancer. ROS are produced within the gastrointestinal (GI) tract, but their roles in pathophysiology and disease pathogenesis have not been well studied. Despite the protective barrier provided by the mucosa, ingested materials and microbial pathogens can induce oxidative injury and GI inflammatory responses involving the epithelium and immune/inflammatory cells. The pathogenesis of various GI diseases including peptic ulcers, gastrointestinal cancers, and inflammatory bowel disease is in part due to oxidative stress. Unraveling the signaling events initiated at the cellular level by oxidative free radicals as well as the physiological responses to such stress is important to better understand disease pathogenesis and to develop new therapies to manage a variety of conditions for which current therapies are not always sufficient.

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Yong-Peng Yu ◽  
Xiang-Lin Chi ◽  
Li-Jun Liu

Gases such as nitric oxide (NO) and carbon monoxide (CO) play important roles both in normal physiology and in disease. Recent studies have shown that hydrogen sulfide (H2S) protects neurons against oxidative stress and ischemia-reperfusion injury and attenuates lipopolysaccharides (LPS) induced neuroinflammation in microglia, exhibiting anti-inflammatory and antiapoptotic activities. The gas H2S is emerging as a novel regulator of important physiologic functions such as arterial diameter, blood flow, and leukocyte adhesion. It has been known that multiple factors, including oxidative stress, free radicals, and neuronal nitric oxide synthesis as well as abnormal inflammatory responses, are involved in the mechanism underlying the brain injury after subarachnoid hemorrhage (SAH). Based on the multiple physiologic functions of H2S, we speculate that it might be a promising, effective, and specific therapy for brain injury after SAH.


2001 ◽  
Vol 280 (5) ◽  
pp. H2094-H2102 ◽  
Author(s):  
B. Chandrasekar ◽  
J. F. Nelson ◽  
J. T. Colston ◽  
G. L. Freeman

The life-prolonging effects of calorie restriction (CR) may be due to reduced damage from cumulative oxidative stress. Our goal was to determine the long-term effects of moderate dietary CR on the myocardial response to reperfusion after a single episode of sublethal ischemia. Male Fisher 344 rats were fed either an ad libitum (AL) or CR (40% less calories) diet. At age 12 mo the animals were anaesthetized and subjected to thoracotomy and a 15-min left-anterior descending coronary artery occlusion. The hearts were reperfused for various periods. GSH and GSSG levels, nuclear factor-κB (NF-κB) DNA binding activity, cytokine, and antioxidant enzyme expression were assessed in the ischemic zones. Sham-operated animals served as controls. Compared with the AL diet, chronic CR limited oxidative stress as seen by rapid recovery in GSH levels in previously ischemic myocardium. CR reduced DNA binding activity of NF-κB. The κB-responsive cytokines interleukin-1β and tumor necrosis factor-α were transiently expressed in the CR group but persisted longer in the AL group. Furthermore, expression of manganese superoxide dismutase, a key antioxidant enzyme, was significantly delayed in the AL group. Collectively these data indicate that CR significantly attenuates myocardial oxidative stress and the postischemic inflammatory response.


2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Ziying Wang ◽  
Zhuanli Zhou ◽  
Xinbing Wei ◽  
Mingwei Wang ◽  
Bi-Ou Wang ◽  
...  

Although studies have seen dramatic advances in the understanding of the pathogenesis of stroke such as oxidative stress, inflammation, excitotoxicity, calcium overload and apoptosis, the delivery of stroke therapies is still a great challenge. In this study, we designed and synthesized a series of novel twin compounds containing tetramethylpyrazine and carnitine substructures and explored their therapeutic potential and mechanism in stroke-related neuronal injury. We first screened the neuroprotective effects of candidate compounds and found that among the tested compounds, LR134 and LR143 exhibited significant neuroprotection as evidenced by reducing cerebral infarct and edema, improving neurological function as well as blood-brain barrier integrity in rats after cerebral ischemia/reperfusion injury. We further demonstrated that the neuroprotective effects of compounds LR134 and LR143 were associated with the reduced inflammatory responses and NADPH oxidase- (NOX2-) mediated oxidative stress and the protection of mitochondria accompanied by the improvement of energy supply. In summary, this study provides direct evidence showing that the novel twin compounds containing tetramethylpyrazine and carnitine substructures have neuroprotective effects with multiple therapeutic targets, suggesting that modulation of these chemical structures may be an innovative therapeutic strategy for treating patients with stroke.


2021 ◽  
Author(s):  
Tingting Li ◽  
Qingsong Chen ◽  
Jiangwen Dai ◽  
Zuotian Huang ◽  
Yunhai Luo ◽  
...  

Abstract Hepatic ischemia reperfusion injury (IRI) is a major factor affecting the prognosis of liver transplantation through a series of severe cell death and inflammatory responses. MicroRNA-141-3p (miR-141-3p) has been reported to be associated with hepatic steatosis and other liver diseases. However, the potential role of miR-141-3p in hepatic IRI is currently unknown. In the present study, we found that miR-141-3p levels were negatively correlated with alanine aminotransferase (ALT)/aspartate aminotransferase (AST) in liver transplantation patients. The results demonstrated that miR-141-3p was decreased in mouse liver tissue after hepatic IRI in mice and in hepatocytes after hypoxia/reoxygenation (H/R). Overexpression of miR-141-3p directly decreased Kelch-like ECH-associated protein 1 (Keap1) levels and attenuated cell apoptosis in vivo and in vitro, while inhibition of miR-141-3p facilitated apoptosis. Further experiments revealed that overexpression of miR-141-3p also attenuated oxidative stress-induced damage in hepatocytes under H/R conditions. Taken together, our results indicate that miR-141-3p plays a major role in hepatic IRI through the Keap1 signaling pathway, and the present study suggests that miR-141-3p might have a protective effect on hepatic IRI to some extent.


2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Ying Li ◽  
Jiliang Jiang ◽  
Liangcheng Tong ◽  
Tingting Gao ◽  
Lei Bai ◽  
...  

Abstract Background Clinically, skeletal muscle ischemia/reperfusion injury is a life-threatening syndrome that is often caused by skeletal muscle damage and is characterized by oxidative stress and inflammatory responses. Bilobalide has been found to have antioxidative and anti-inflammatory effects. However, it is unclear whether bilobalide can protect skeletal muscle from ischemia/reperfusion injury. Methods The effects of bilobalide on ischemia/reperfusion-injured skeletal muscle were investigated by performing hematoxylin and eosin staining and assessing the wet weight/dry weight ratio of muscle tissue. Then, we measured lipid peroxidation, antioxidant activity and inflammatory cytokine levels. Moreover, Western blotting was conducted to examine the protein levels of MAPK/NF-κB pathway members. Results Bilobalide treatment could protected hind limb skeletal muscle from ischemia/reperfusion injury by alleviating oxidative stress and inflammatory responses via the MAPK/NF-κB pathways. Conclusions Bilobalide may be a promising drug for I/R-injured muscle tissue. However, the specific mechanisms for the protective effects still need further study.


2009 ◽  
Vol 2 (3) ◽  
pp. 172-175 ◽  
Author(s):  
Angana Gupta Rajapakse ◽  
Xiu-Fen Ming ◽  
João M. Carvas ◽  
Zhihong Yang

Elevated cellular levels of proteinO-linked β-N-acetylglucosamine (O-GlcNAc) through hexosamine biosynthesis pathway (HBP) are suggested to contribute to cardiovascular adverse effects under chronic hyperglycemic condition associated with oxidative stress and inflammation. Conversely, enhancingO-GlcNAc levels have also been demonstrated being protective against myocardial ischemia/reperfusion injury. We recently demonstrated that hyperglycemia increases oxidative stress and HBP flux in endothelial cells and enhances endothelial expression of vascular adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) in response to tumor necrosis factor-α (TNFα) through oxidative stress rather than HBP pathway. Here we present further complementary data showing that enhancingO-GlcNAc levels by glucosamine does not mimic hyperglycemia's effect on TNFα-induced endothelial VCAM-1 and ICAM-1 expression. Glucosamine however inhibits ICAM-1 (not VCAM-1) expression and induces superoxide generation in the cells. The results further suggest that increasedO-GlcNAc levels do not mediate the enhancing effect of hyperglycemia on the endothelial inflammatory responses to TNFα. In contrast, it exerts certain anti-inflammatory effects accompanied by pro-oxidative properties. Further work should delineate the exact role of HPB pathway in different aspects of cardiovascular functions, especially those of diabetic cardiovascular complications.


Nutrients ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2765
Author(s):  
Francine M. Almeida ◽  
Angela S. Battochio ◽  
João P. Napoli ◽  
Katiusa A. Alves ◽  
Grace S. Balbin ◽  
...  

Ischemia-reperfusion injury (IRI) is one of the factors limiting the success of lung transplantation (LTx). IRI increases death risk after transplantation through innate immune system activation and inflammation induction. Some studies have shown that creatine (Cr) protects tissues from ischemic damage by its antioxidant action. We evaluated the effects of Cr supplementation on IRI after unilateral LTx in rats. Sixty-four rats were divided into four groups: water + 90 min of ischemia; Cr + 90 min of ischemia; water + 180 min of ischemia; and Cr + 180 min of ischemia. Donor animals received oral Cr supplementation (0.5 g/kg/day) or vehicle (water) for five days prior to LTx. The left lung was exposed to cold ischemia for 90 or 180 min, followed by reperfusion for 2 h. We evaluated the ventilatory mechanics and inflammatory responses of the graft. Cr-treated animals showed a significant decrease in exhaled nitric oxide levels and inflammatory cells in blood, bronchoalveolar lavage fluid and lung tissue. Moreover, edema, cell proliferation and apoptosis in lung parenchyma were reduced in Cr groups. Finally, TLR-4, IL-6 and CINC-1 levels were lower in Cr-treated animals. We concluded that Cr caused a significant decrease in the majority of inflammation parameters evaluated and had a protective effect on the IRI after LTx in rats.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yong-Peng Yu ◽  
Xiang-Lin Chi ◽  
Li-Jun Liu

Gases such as nitric oxide (NO) and carbon monoxide (CO) play important roles both in normal physiology and in disease. Recent studies have shown that hydrogen sulfide (H2S) protects neurons against oxidative stress and ischemia-reperfusion injury and attenuates lipopolysaccharides (LPS) induced neuroinflammation in microglia, exhibiting anti-inflammatory and antiapoptotic activities. The gas H2S is emerging as a novel regulator of important physiologic functions such as arterial diameter, blood flow, and leukocyte adhesion. It has been known that multiple factors, including oxidative stress, free radicals, and neuronal nitric oxide synthesis as well as abnormal inflammatory responses, are involved in the mechanism underlying the brain injury after subarachnoid hemorrhage (SAH). Based on the multiple physiologic functions of H2S, we speculate that it might be a promising, effective, and specific therapy for brain injury after SAH.


2019 ◽  
Vol 24 (6) ◽  
pp. 509-520 ◽  
Author(s):  
Eduardo Fuentes ◽  
Rodrigo Moore-Carrasco ◽  
Antonio Marcus de Andrade Paes ◽  
Andres Trostchansky

Myocardial infarction, commonly known as heart attack, evolves from the rupture of unstable atherosclerotic plaques to coronary thrombosis and myocardial ischemia–reperfusion injury. A body of evidence supports a close relationship between the alterations following an ischemia–reperfusion injury-induced oxidative stress and platelet activity. Through their critical role in thrombogenesis and inflammatory responses, platelets are fully (totally) implicated from atherothrombotic plaque formation to myocardial infarction onset and expansion. However, mere platelet aggregation prevention does not offer full protection, suggesting that other antiplatelet therapy mechanisms may also be involved. Thus, the present review discusses the integrative role of platelets, oxidative stress, and antiplatelet therapy in triggering myocardial infarction pathophysiology.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yi Yu ◽  
Yuan Yan ◽  
Fanglin Niu ◽  
Yajun Wang ◽  
Xueyi Chen ◽  
...  

AbstractFerroptosis, a recently identified and iron-dependent cell death, differs from other cell death such as apoptosis, necroptosis, pyroptosis, and autophagy-dependent cell death. This form of cell death does not exhibit typical morphological and biochemical characteristics, including cell shrinkage, mitochondrial fragmentation, nuclear condensation. The dysfunction of lipid peroxide clearance, the presence of redox-active iron as well as oxidation of polyunsaturated fatty acid (PUFA)-containing phospholipids are three essential features of ferroptosis. Iron metabolism and lipid peroxidation signaling are increasingly recognized as central mediators of ferroptosis. Ferroptosis plays an important role in the regulation of oxidative stress and inflammatory responses. Accumulating evidence suggests that ferroptosis is implicated in a variety of cardiovascular diseases such as atherosclerosis, stroke, ischemia-reperfusion injury, and heart failure, indicating that targeting ferroptosis will present a novel therapeutic approach against cardiovascular diseases. Here, we provide an overview of the features, process, function, and mechanisms of ferroptosis, and its increasingly connected relevance to oxidative stress, inflammation, and cardiovascular diseases.


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