scholarly journals Carbon Monoxide Protects against Liver Failure through Nitric Oxide–induced Heme Oxygenase 1

2003 ◽  
Vol 198 (11) ◽  
pp. 1707-1716 ◽  
Author(s):  
Brian S. Zuckerbraun ◽  
Timothy R. Billiar ◽  
Sherrie L. Otterbein ◽  
Peter K.M. Kim ◽  
Fang Liu ◽  
...  

Carbon monoxide (CO) and nitric oxide (NO) each have mechanistically unique roles in various inflammatory disorders. Although it is known that CO can induce production of NO and that NO can induce expression of the cytoprotective enzyme heme oxygenase 1 (HO-1), there is no information whether the protective effect of CO ever requires NO production or whether either gas must induce expression of HO-1 to exert its functional effects. Using in vitro and in vivo models of tumor necrosis factor α–induced hepatocyte cell death in mice, we find that activation of nuclear factor κB and increased expression of inducible NO are required for the protective effects of CO, whereas the protective effects of NO require up-regulation of HO-1 expression. When protection from cell death is initiated by CO, NO production and HO-1 activity are each required for the protective effect showing for the first time an essential synergy between these two molecules in tandem providing potent cytoprotection.

Biomedicines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 438
Author(s):  
Yu-An Lu ◽  
Jun-Geon Je ◽  
Jin Hwang ◽  
You-Jin Jeon ◽  
BoMi Ryu

Nitric oxide (NO), an endothelial-derived relaxing factor synthesized by endothelial nitric oxide synthase (eNOS) in endothelial cells, enhances vasodilation by modulating vascular tone. The calcium concentration critically influences eNOS activation in endothelial cells. Thus, modulation of calcium-dependent signaling pathways may be a potential therapeutic strategy to enhance vasodilation. Marine algae reportedly possess protective effects against cardiovascular disorders, including hypertension and vascular dysfunction; however, the underlying molecular signaling pathways remain elusive. In the present study, we extracted and isolated dieckol from Ecklonia cava and investigated calcium transit-enhanced vasodilation. Calcium modulation via the well-known M3 muscarinic acetylcholine receptor (AchM3R), which is linked to NO formation, was investigated and the vasodilatory effect of dieckol was verified. Our results indicated that dieckol effectively promoted NO generation via the PI3K/Akt/eNOS axis and calcium transients influenced by AchM3R. We also treated Tg(flk: EGFP) transgenic zebrafish with dieckol to assess its vasodilatory effect. Dieckol promoted vasodilation by enlarging the dorsal aorta diameter, thus regulating blood flow velocity. In conclusion, our findings suggest that dieckol modulates calcium transit through AchM3R, increases endothelial-dependent NO production, and efficiently enhances vasodilation. Thus, E. cava and its derivative, dieckol, can be considered as potential natural vasodilators.


2005 ◽  
Vol 289 (3) ◽  
pp. G607-G613 ◽  
Author(s):  
Brian S. Zuckerbraun ◽  
Leo E. Otterbein ◽  
Patricia Boyle ◽  
Ronald Jaffe ◽  
Jeffrey Upperman ◽  
...  

Necrotizing enterocolitis (NEC) is a disease of neonates that is increasing in incidence and often results in significant morbidity and mortality. Carbon monoxide (CO), a byproduct of the catabolism of heme, is known to have anti-inflammatory and antiapoptotic properties. In this study, we aimed to demonstrate that inhaled CO protects against the development of intestinal inflammation in a model of experimental NEC as well as decreases enterocyte cell death in vitro. Additionally, we also aimed to demonstrate that CO decreases enterocyte production of inducible nitric oxide synthase (iNOS) and nitric oxide (NO). Neonatal rats were exposed to intermittent hypoxia exposure and formula feeding to induce experimental NEC. Animals randomized to CO treatment were put in an environment containing 0.025% CO for 1 h/day on days 1–3 of life. All animals were killed on day 4 of life. In vitro experiments were performed with IEC-6 cells, a rat enterocyte cell line. Cells were examined for viability, iNOS production, and elaboration of NO. We found that CO diminished levels of serum inflammatory cytokines and nitrites, protected against intestinal inflammation, and decreased ileal iNOS production and protein nitration in a model of experimental NEC. In vitro, CO decreased cytokine- or hypoxia/endotoxin-induced iNOS and NO production. CO also abrogated TNF-α- and actinomycin D-induced apoptosis or hypoxia/endotoxin-induced cell death. In conclusion, 1 h of daily low-dose inhaled CO protected against the development of intestinal inflammation in a model of experimental NEC. iNOS and NO production were decreased by CO both in vivo and in vitro. CO may prove to be a useful clinical adjunct in the treatment of NEC.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Xiu E. Feng ◽  
Tai Gang Liang ◽  
Jie Gao ◽  
De Peng Kong ◽  
Rui Ge ◽  
...  

Increasing evidence has demonstrated that heme oxygenase-1 (HO-1) is a key enzyme triggered by cellular stress, exhibiting cytoprotective, antioxidant, and anti-inflammatory abilities. Previously, we prepared a series of novel active halophenols possessing strong antioxidant activities in vitro and in vivo. In the present study, we demonstrated that these halophenols exhibited significant protective effects against H2O2-induced injury in EA.hy926 cells by inhibition of apoptosis and ROS and TNF-αproduction, as well as induction of the upregulation of HO-1, the magnitude of which correlated with their cytoprotective actions. Further experiments which aimed to determine the mechanistic basis of these actions indicated that the halophenols induced the activation of Nrf2, Erk1/2, and PI3K/Akt without obvious effects on the phosphorylation of p38, JNK, or the expression of PKC-δ. This was validated with the use of PD98059 and Wortmannin, specific inhibitors of Erk1/2 and PI3K, respectively. Overall, our study is the first to demonstrate that the cytoprotective actions of halophenols involve their antiapoptotic, antioxidant, and anti-inflammatory abilities, which are mediated by the upregulation of Nrf2-dependent HO-1 expression and reductions in ROS and TNF-αgeneration via the activation of Erk1/2 and PI3K/Akt in EA.hy926 cells. HO-1 may thus be an important potential target for further research into the cytoprotective actions of halophenols.


2001 ◽  
Vol 280 (5) ◽  
pp. C1242-C1254 ◽  
Author(s):  
Ragnar Henningsson ◽  
Per Alm ◽  
Ingmar Lundquist

We investigated, by a combined in vivo and in vitro approach, the temporal changes of islet nitric oxide synthase (NOS)-derived nitric oxide (NO) and heme oxygenase (HO)-derived carbon monoxide (CO) production in relation to insulin and glucagon secretion during acute endotoxemia induced by lipopolysaccharide (LPS) in mice. Basal plasma glucagon, islet cAMP and cGMP content after in vitro incubation, the insulin response to glucose in vivo and in vitro, and the insulin and glucagon responses to the adenylate cyclase activator forskolin were greatly increased after LPS. Immunoblots demonstrated expression of inducible NOS (iNOS), inducible HO (HO-1), and an increased expression of constitutive HO (HO-2) in islet tissue. Immunocytochemistry revealed a marked expression of iNOS in many β-cells, but only in single α-cells after LPS. Moreover, biochemical analysis showed a time dependent and markedly increased production of NO and CO in these islets. Addition of a NOS inhibitor to such islets evoked a marked potentiation of glucose-stimulated insulin release. Finally, after incubation in vitro, a marked suppression of NO production by both exogenous CO and glucagon was observed in control islets. This effect occurred independently of a concomitant inhibition of guanylyl cyclase. We suggest that the impairing effect of increased production of islet NO on insulin secretion during acute endotoxemia is antagonized by increased activities of the islet cAMP and HO-CO systems, constituting important compensatory mechanisms against the noxious and diabetogenic actions of NO in endocrine pancreas.


2012 ◽  
Vol 2012 ◽  
pp. 1-19 ◽  
Author(s):  
Myrna Constantin ◽  
Alexander J. S. Choi ◽  
Suzanne M. Cloonan ◽  
Stefan W. Ryter

Heme oxygenase (HO), a catabolic enzyme, provides the rate-limiting step in the oxidative breakdown of heme, to generate carbon monoxide (CO), iron, and biliverdin-IXα. Induction of the inducible form, HO-1, in tissues is generally regarded as a protective mechanism. Over the last decade, considerable progress has been made in defining the therapeutic potential of HO-1 in a number of preclinical models of lung tissue injury and disease. Likewise, tissue-protective effects of CO, when applied at low concentration, have been observed in many of these models. Recent studies have expanded this concept to include chemical CO-releasing molecules (CORMs). Collectively, salutary effects of the HO-1/CO system have been demonstrated in lung inflammation/acute lung injury, lung and vascular transplantation, sepsis, and pulmonary hypertension models. The beneficial effects of HO-1/CO are conveyed in part through the inhibition or modulation of inflammatory, apoptotic, and proliferative processes. Recent advances, however, suggest that the regulation of autophagy and the preservation of mitochondrial homeostasis may serve as additional candidate mechanisms. Further preclinical and clinical trials are needed to ascertain the therapeutic potential of HO-1/CO in human clinical disease.


2016 ◽  
Vol 59 (2) ◽  
pp. 756-762 ◽  
Author(s):  
Aniket Nikam ◽  
Anthony Ollivier ◽  
Michael Rivard ◽  
Jayne Louise Wilson ◽  
Kevin Mebarki ◽  
...  

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