Search results for "heme oxygenase"

Anti-inflammatory actions of the heme oxygenase-1 pathway.

2003

Heme oxygenase 1 (HO-1) is induced by oxidative or nitrosative stress, cytokines and other mediators produced during inflammatory processes, likely as part of a defence system in cells exposed to stress to provide a negative feedback for cell activation and the production of mediators, which could modulate the inflammatory response. HO-1 activity results in the inhibition of oxidative damage and apoptosis, with significant reductions in inflammatory events including edema, leukocyte adhesion and migration, and production of inflammatory cytokines. HO-1 is induced by nitric oxide (NO) in different biological systems and can control the increased production of this mediator observed in many i…

Heme oxygenase-1 inhibits apoptosis in Caco-2 cells via activation of Akt pathway

2005

Heme oxygenase-1 can play a protective role against cellular stress. In colon cancer cells, these effects would be relevant to oncogenesis and resistance to chemotherapy. The aim of the study was to examine the effects of heme oxygenase-1 induction on cell survival in a human colon cancer cell line, Caco-2. Serum deprivation induced apoptosis, reduced Akt and p38 phosphorylation, and increased p21(Cip/WAF1) levels. Heme oxygenase-1 induction by treatment with cobalt protoporphyrin IX resulted in resistance to apoptosis, activation of Akt, reduction in p21(Cip/WAF1) levels and modification of bcl2/bax ratio towards survival. Indomethacin reduced apoptosis but in contrast to heme oxygenase-1,…

Living with stress: regulation of antioxidant defense genes in the subterranean, hypoxia-tolerant mole rat, Spalax.

2011

Lack of oxygen is life threatening for most mammals. It is therefore of biomedical interest to investigate the adaptive mechanisms which enable mammalian species to tolerate extremely hypoxic conditions. The subterranean mole rat Spalax survives substantially longer periods of hypoxia than the laboratory rat. We hypothesized that genes of the antioxidant defense, detoxifying harmful reactive oxygen species generated during hypoxia and hyperoxia, are involved in Spalax underground adaptation. Using quantitative RT-PCR, we analyzed the mRNA expression levels of seven antioxidant defense genes (catalase, glutathione peroxidase 1, glutathione-S-transferase Pi1, heme oxygenase 1, superoxide dism…

Prenatal low-level exposure to CO alters postnatal development of hippocampal nitric oxide synthase and haem-oxygenase activities in rats.

2001

The effects of prenatal CO exposure (150 ppm from days 0 to 20 of pregnancy) on the postnatal development of hippocampal neuronal NO synthase (nNOS) and haem-oxygenase (HO-2) isoform activities in 15-, 30- and 90-d-old rats were investigated. Unlike HO-2, hippocampal nNOS activity increased from postnatal days 15-90 in controls. Prenatal CO produced a long-lasting decrease in either nNOS or HO-2. The results suggest that the altered developmental profile of hippocampal nNOS and HO-2 activities could be involved in cognitive deficits and long-term potentiation dysfunction exhibited by rats prenatally exposed to CO levels resulting in carboxyhaemoglobin (HbCO) levels equivalent to those obser…

Redox regulation of genome stability by effects on gene expression, epigenetic pathways and DNA damage/repair

2015

Reactive oxygen and nitrogen species (e.g. H2O2, nitric oxide) confer redox regulation of essential cellular signaling pathways such as cell differentiation, proliferation, migration and apoptosis. In addition, classical regulation of gene expression or activity, including gene transcription to RNA followed by translation to the protein level, by transcription factors (e.g. NF-κB, HIF-1α) and mRNA binding proteins (e.g. GAPDH, HuR) is subject to redox regulation. This review will give an update of recent discoveries in this field, and specifically highlight the impact of reactive oxygen and nitrogen species on DNA repair systems that contribute to genomic stability. Emphasis will be placed …

Noise‐induced vascular dysfunction, oxidative stress and inflammationare improved by pharmacological heme oxygenase‐1 induction

2020

Role of heme oxygenase-1 (HSP32) and HSP90 in glioblastoma

2017

Glioblastoma (GBM) is the most common and malignant primary brain tumor in adults. The current treatment regimes for glioblastoma demonstrated a low efficiency and offer a poor prognosis. Advancements in conventional treatment strategies have only yielded modest improvements in overall survival. The heat shockproteins, heme oxygenase-1 (HO-1) and Hsp90, serve these pivotal roles in tumor cells and have been identified as effective targets for developing therapeutics. This topic review summarizes the current preclinical and clinical evidences and rationale to define the potential of HO-1 and Hsp90 in GBM progression and chemoresistance.

2018

PGC1α Regulates the Endothelial Response to Fluid Shear Stress via Telomerase Reverse Transcriptase Control of Heme Oxygenase-1

2021

AbstractFluid shear stress (FSS) is known to mediate multiple phenotypic changes in the endothelium. Laminar FSS (undisturbed flow) is known to promote endothelial alignment to flow that is key to stabilizing the endothelium and rendering it resistant to atherosclerosis and thrombosis. The molecular pathways responsible for endothelial responses to FSS are only partially understood. Here we have identified peroxisome proliferator gamma coactivator-1α (PGC-1α) as a flow-responsive gene required for endothelial flow alignment in vitro and in vivo. Compared to oscillatory FSS (disturbed flow) or static conditions, laminar FSS (undisturbed flow) increased PGC-1α expression and its transcription…

Optogenetic Control of Bacterial Expression by Red Light

2022

In optogenetics, as in nature, sensory photoreceptors serve to control cellular processes by light. Bacteriophytochrome (BphP) photoreceptors sense red and far-red light via a biliverdin chromophore and, in response, cycle between the spectroscopically, structurally, and functionally distinct Pr and Pfr states. BphPs commonly belong to two-component systems that control the phosphorylation of cognate response regulators and downstream gene expression through histidine kinase modules. We recently demonstrated that the paradigm BphP from Deinococcus radiodurans exclusively acts as a phosphatase but that its photosensory module can control the histidine kinase activity of homologous receptors.…