scholarly journals Heme oxygenase-2 (HO-2) binds and buffers labile heme, which is largely oxidized, in human embryonic kidney cells

2021 ◽  
Author(s):  
David A Hanna ◽  
Courtney M Moore ◽  
Liu Liu ◽  
Xiaojing Yuan ◽  
Angela S Fleischhacker ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Physiological Function ◽  
Hek293 Cells ◽  
Kidney Cells ◽  
Human Embryonic Kidney ◽  
Human Embryonic Kidney Cells ◽  
Heme Oxygenases ◽  
Heme Trafficking ◽  
Ferrous Heme

Heme oxygenases (HO) detoxify heme by oxidatively degrading it into carbon monoxide, iron, and biliverdin, which is reduced to bilirubin and excreted. Humans express two isoforms: inducible HO-1, which is up-regulated in response to various stressors, including excess heme, and constitutive HO-2. While much is known about the regulation and physiological function of HO-1, comparatively little is known about the role of HO-2 in regulating heme homeostasis. The biochemical necessity for expressing constitutive HO-2 is largely dependent on whether heme is sufficiently abundant and accessible as a substrate under conditions in which HO-1 is not induced. By measuring labile heme, total heme, and bilirubin in human embryonic kidney HEK293 cells with silenced or over-expressed HO-2, and various HO-2 mutant alleles, we found that endogenous heme is too limiting to support HO-2 catalyzed heme degradation. Rather, we discovered that a novel role for HO-2 is to bind and buffer labile heme. Taken together, in the absence of excess heme, we propose that HO-2 regulates heme homeostasis by acting as a heme buffering factor in control of heme bioavailability. When heme is in excess, HO-1 is induced and both HO-2 and HO-1 can provide protection from heme toxicity by enzymatically degrading it. Our results explain why catalytically inactive mutants of HO-2 are cytoprotective against oxidative stress. Moreover, the change in bioavailable heme due to HO-2 overexpression, which selectively binds ferric over ferrous heme, is consistent with the labile heme pool being oxidized, thereby providing new insights into heme trafficking and signaling.

scholarly journals Transcriptomic and Proteomic Analysis Reveals Mechanisms of Patulin-Induced Cell Toxicity in Human Embryonic Kidney Cells

Toxins ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 681
Author(s):  
Nianfa Han ◽  
Ruilin Luo ◽  
Jiayu Liu ◽  
Tianmin Guo ◽  
Jiayu Feng ◽  
...  
Keyword(s):  
Caspase 3 ◽  
Digital Gene Expression ◽  
Hek293 Cells ◽  
Kidney Cells ◽  
Oxygen Species ◽  
Human Embryonic Kidney ◽  
Absolute Quantitation ◽  
Human Embryonic Kidney Cells ◽  
Isobaric Tags ◽  
Induced Apoptosis

Patulin (PAT) is a natural mycotoxin that commonly contaminates fruits and fruit-based products. Previous work indicated that PAT-induced apoptosis in which reactive oxygen species (ROS) are involved in human embryonic kidney (HEK293) cells. To uncover novel aspects of the possible mechanism of PAT nephrotoxicity, the transcriptome and proteome profiles were investigated using the digital gene expression (DGE) and isobaric tags for relative and absolute quantitation (iTRAQ) proteomic approaches. A total of 127 genes and 85 proteins were found to express differentially in response to 5 μM PAT for 10 h in HEK293 cells. The most dramatic changes of expression were noticed with genes or proteins related to apoptosis, oxidative phosphorylation ribosome and cell cycle. Especially, the activation of caspase 3, UQCR11, active transport form and endocytosis appeared to be crucial in PAT kidney cytotoxicity. PAT also seemed to be associated with cancer and neuropathic disease as pathways associated with carcinogenesis, Alzheimer’s disease and Parkinson’s disease were induced. Overall, this study served to uncover overall insights associated with signaling pathway that modulated the PAT toxicity mechanism.

scholarly journals Induction of CMV-1 promoter by 4-hydroxy-2-nonenal in human embryonic kidney cells.

2010 ◽  
Vol 57 (2) ◽  
Author(s):  
Morana Jaganjac ◽  
Tanja Matijevic ◽  
Marina Cindric ◽  
Ana Cipak ◽  
Lidija Mrakovcic ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Lipid Peroxidation ◽  
Free Radicals ◽  
Yellow Fluorescent Protein ◽  
Viral Reactivation ◽  
Kidney Cells ◽  
Human Embryonic Kidney ◽  
Human Embryonic Kidney Cells ◽  
Reactive Aldehydes

Oxidative stress, i.e., excessive production of oxygen free radicals and reactive oxygen species, leads to lipid peroxidation and to formation of reactive aldehydes which act as second messengers of free radicals. It has previously been shown that oxidative stress may be involved in the transcriptional regulation of cytomegalovirus (CMV) immediate early promoter, involved in viral reactivation from latency. In the current study we used a plasmid containing the yellow fluorescent protein (YFP) gene under the control of CMV-1 promoter to monitor the influence of hydrogen peroxide and reactive aldehydes, 4-hydroxy-2-nonenal (HNE) and acrolein, on CMV-1 promoter activation in human embryonic kidney cells (HEK293). While acrolein was ineffective, hydrogen peroxide slightly (50 %) stimulated the CMV promoter. In contrast, HNE had a strong, up to 3-fold, enhancing effect on the CMV-1 promoter within four as well as after 24h of treatment. The most effective was the treatment with 24 microM HNE. This effect of HNE suggests that stressful conditions associated with lipid peroxidation could lead to CMV activation.

Oxidative stress contributes to silica nanoparticle-induced cytotoxicity in human embryonic kidney cells

2009 ◽  
Vol 23 (5) ◽  
pp. 808-815 ◽  
Author(s):  
Fen Wang ◽  
Feng Gao ◽  
Minbo Lan ◽  
Huihui Yuan ◽  
Yongping Huang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Silica Nanoparticle ◽  
Kidney Cells ◽  
Human Embryonic Kidney ◽  
Human Embryonic Kidney Cells

scholarly journals TMEM16F Regulates Baseline Phosphatidylserine Exposure and Cell Viability in Human Embryonic Kidney Cells

2016 ◽  
Vol 38 (6) ◽  
pp. 2452-2463 ◽  
Author(s):  
Laura K. Schenk ◽  
Ulf Schulze ◽  
Sebastian Henke ◽  
Thomas Weide ◽  
Hermann Pavenstädt
Keyword(s):  
Signaling Pathways ◽  
Transmembrane Protein ◽  
Cell Cycle Control ◽  
Akt Signaling ◽  
Hek293 Cells ◽  
Kidney Cells ◽  
Human Embryonic Kidney ◽  
Human Embryonic Kidney Cells ◽  
Phospholipid Scramblase ◽  
Phosphatidylserine Exposure

Background / Aims: TMEM16F is a transmembrane protein from a conserved family of Ca2+-activated proteins, which is highly expressed in several tissues. TMEM16F confers phospholipid scramblase activity and Ca2+-activated electrolyte channel activity. Potentially thereby, TMEM16F is involved in cell cycle control and apoptotic signaling. The present study evaluated the role of TMEM16F on cell proliferation and viability in Human Embryonic Kidney cells. Methods: An inducible knockdown of TMEM16F was generated and markers of apoptosis and proliferation were assessed via flow cytometry, western blotting and MTT uptake assay under different conditions. Results: TMEM16F knockdown resulted in attenuated growth of HEK293 cells. This observation correlated with an increased phosphatidylserine exposure and a decreased fraction of viable cells. Interestingly, the cells were not sensitized to Staurosporine- induced cell death. Western blot analyses displayed a parallel activation of pro- and antiapoptotic signaling pathways: Caspase 3 cleavage and Cyclin D1 abundance were simultaneously increased. Furthermore, knockdown of TMEM16F led to activation of AKT signaling. Conclusion: TMEM16F modifies viability of Human Embryonic Kidney cells via its function as a phospholipid scramblase and activation of AKT signaling pathways.

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