scholarly journals Calpain Mediates a von Hippel-Lindau Protein–independent Destruction of Hypoxia-inducible Factor-1α

2006 ◽  
Vol 17 (4) ◽  
pp. 1549-1558 ◽  
Author(s):  
Jie Zhou ◽  
Roman Köhl ◽  
Barbara Herr ◽  
Ronald Frank ◽  
Bernhard Brüne
Keyword(s):  
Renal Carcinoma ◽  
Hypoxia Inducible Factor ◽  
Active Role ◽  
Carcinoma Cells ◽  
No Donor ◽  
Human Embryonic Kidney Cells ◽  
Von Hippel Lindau ◽  
Hypoxia Inducible Factor 1 ◽  
Calpain Inhibitors

Hypoxia-inducible factor 1 (HIF-1) is controlled through stability regulation of its alpha subunit, which is expressed under hypoxia but degraded under normoxia. Degradation of HIF-1α requires association of the von Hippel Lindau protein (pVHL) to provoke ubiquitination followed by proteasomal digestion. Besides hypoxia, nitric oxide (NO) stabilizes HIF-1α under normoxia but destabilizes the protein under hypoxia. To understand the role of NO under hypoxia we made use of pVHL-deficient renal carcinoma cells (RCC4) that show a high steady state HIF-1α expression under normoxia. Exposing RCC4 cells to hypoxia in combination with the NO donor DETA-NO (2,2′-(hydroxynitrosohydrazono) bis-ethanimine), but not hypoxia or DETA-NO alone, decreased HIF-1α protein and attenuated HIF-1 transactivation. Mechanistically, we noticed a role of calpain because calpain inhibitors reversed HIF-1α degradation. Furthermore, chelating intracellular calcium attenuated HIF-1α destruction by hypoxia/DETA-NO, whereas a calcium increase was sufficient to lower the amount of HIF-1α even under normoxia. An active role of calpain in lowering HIF-1α amount was also evident in pVHL-containing human embryonic kidney cells when the calcium pump inhibitor thapsigargin reduced HIF-1α that was stabilized by the prolyl hydroxylase inhibitor dimethyloxalylglycine (DMOG). We conclude that calcium contributes to HIF-1α destruction involving the calpain system.

scholarly journals Stable expression of HIF-1α in tubular epithelial cells promotes interstitial fibrosis

2008 ◽  
Vol 295 (4) ◽  
pp. F1023-F1029 ◽  
Author(s):  
Kuniko Kimura ◽  
Masayuki Iwano ◽  
Debra F. Higgins ◽  
Yukinari Yamaguchi ◽  
Kimihiko Nakatani ◽  
...  
Keyword(s):  
Renal Fibrosis ◽  
Interstitial Fibrosis ◽  
Hypoxia Inducible Factor ◽  
Stable Expression ◽  
Von Hippel Lindau ◽  
Hypoxia Inducible Factor 1 ◽  
Novel Approach ◽  
Renal Ablation ◽  
Oxygen Sensitive

Chronic hypoxia accelerates renal fibrosis. The chief mediator of the hypoxic response is hypoxia-inducible factor 1 (HIF-1) and its oxygen-sensitive component HIF-1α. HIF-1 regulates a wide variety of genes, some of which are closely associated with tissue fibrosis. To determine the specific role of HIF-1 in renal fibrosis, we generated a knockout mouse in which tubular epithelial expression of von Hippel-Lindau tumor suppressor (VHL), which acts as a ubiquitin ligase to promote proteolysis of HIF-1α, was targeted. We investigated the effect of VHL deletion (i.e., stable expression of HIF-1α) histologically and used the anti-HIF-1α agent [3-(5′-hydroxymethyl-2′-furyl)-1-benzyl indazole] (YC-1) to test whether inhibition of HIF-1α could represent a novel approach to treating renal fibrosis. The area of renal fibrosis was significantly increased in a 5/6 renal ablation model of VHL−/−mice and in all VHL−/−mice at least 60 wk of age. Injection of YC-1 inhibited the progression of renal fibrosis in unilateral ureteral obstruction model mice. In conclusion, HIF-1α appears to be a critical contributor to the progression of renal fibrosis and could be a useful target for its treatment.

scholarly journals Tumor Necrosis Factor-α Causes Accumulation of a Ubiquitinated Form of Hypoxia Inducible Factor-1α through a Nuclear Factor-κB-Dependent Pathway

2003 ◽  
Vol 14 (6) ◽  
pp. 2216-2225 ◽  
Author(s):  
Jie Zhou ◽  
Tobias Schmid ◽  
Bernhard Brüne
Keyword(s):  
Hypoxia Inducible Factor ◽  
Nuclear Factor Κb ◽  
Metabolic Adaptation ◽  
Adaptation To Hypoxia ◽  
Nuclear Factor ◽  
Human Embryonic Kidney Cells ◽  
Von Hippel Lindau ◽  
Hypoxia Inducible Factor 1 ◽  
Tnf Α ◽  
Factor Α

Hypoxia-inducible factor-1 (HIF-1) is a regulator of metabolic adaptation to hypoxia. It is now appreciated that HIF-1α accumulation is achieved under normoxic conditions by various factors, such as TNF-α. Here, it was our intention to gain insight into the signaling mechanisms used by TNF-α to stimulate HIF-1α. In tubular LLC-PK1or human embryonic kidney cells, TNF-α induced accumulation of HIF-1α protein but not HIF-1α mRNA. Blocking nuclear factor (NF)-κB with sulfasalazine or expression of an IκB superrepressor attenuated HIF-1α accumulation, whereas transfection of active p50/p65-NF-κB subunits mimicked a TNF-α response. Experiments with actinomycin D and cycloheximide also pointed to a transcriptional and translational process in facilitating the TNF-α response. Interestingly, and in contrast to established hypoxic signaling concepts, TNF-α elicited HIF-1α accumulation in a ubiquitinated form that still bound the von Hippel-Lindau (pVHL) protein. These data indicate that HIF-1α accumulation by TNF-α demands the NF-κB pathway, preserves ubiquitination of HIF-1α, and allows the HIF-1α-pVHL interaction.

scholarly journals Cooperative Blockade of CK2 and ATM Kinases Drives Apoptosis in VHL-Deficient Renal Carcinoma Cells through ROS Overproduction

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 576
Author(s):  
Sofia Giacosa ◽  
Catherine Pillet ◽  
Irinka Séraudie ◽  
Laurent Guyon ◽  
Yann Wallez ◽  
...  
Keyword(s):  
High Throughput Screening ◽  
Renal Carcinoma ◽  
Kinase Inhibitors ◽  
Ex Vivo ◽  
Cancer Therapeutics ◽  
Carcinoma Cells ◽  
Wild Type ◽  
Cell Renal Cell Carcinoma ◽  
Von Hippel Lindau ◽  
Renal Carcinoma Cells

Kinase-targeted agents demonstrate antitumor activity in advanced metastatic clear cell renal cell carcinoma (ccRCC), which remains largely incurable. Integration of genomic approaches through small-molecules and genetically based high-throughput screening holds the promise of improved discovery of candidate targets for cancer therapy. The 786-O cell line represents a model for most ccRCC that have a loss of functional pVHL (von Hippel-Lindau). A multiplexed assay was used to study the cellular fitness of a panel of engineered ccRCC isogenic 786-O VHL− cell lines in response to a collection of targeted cancer therapeutics including kinase inhibitors, allowing the interrogation of over 2880 drug–gene pairs. Among diverse patterns of drug sensitivities, investigation of the mechanistic effect of one selected drug combination on tumor spheroids and ex vivo renal tumor slice cultures showed that VHL-defective ccRCC cells were more vulnerable to the combined inhibition of the CK2 and ATM kinases than wild-type VHL cells. Importantly, we found that HIF-2α acts as a key mediator that potentiates the response to combined CK2/ATM inhibition by triggering ROS-dependent apoptosis. Importantly, our findings reveal a selective killing of VHL-deficient renal carcinoma cells and provide a rationale for a mechanism-based use of combined CK2/ATM inhibitors for improved patient care in metastatic VHL-ccRCC.

scholarly journals The Role of Hypoxia-Inducible Factor 1 in Mild Cognitive Impairment

2016 ◽  
Vol 37 (6) ◽  
pp. 969-977 ◽  
Author(s):  
Osigbemhe Iyalomhe ◽  
Sabina Swierczek ◽  
Ngozi Enwerem ◽  
Yuanxiu Chen ◽  
Monica O. Adedeji ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Hypoxia Inducible Factor ◽  
Hypoxia Inducible Factor 1

scholarly journals Suppression of Hypoxia-Inducible Factor 2α Restores p53 Activity via Hdm2 and Reverses Chemoresistance of Renal Carcinoma Cells

2009 ◽  
Vol 69 (23) ◽  
pp. 9056-9064 ◽  
Author(s):  
Andrew M. Roberts ◽  
Ian R. Watson ◽  
Andrew J. Evans ◽  
David A. Foster ◽  
Meredith S. Irwin ◽  
...  
Keyword(s):  
Renal Carcinoma ◽  
Hypoxia Inducible Factor ◽  
Carcinoma Cells ◽  
Renal Carcinoma Cells

Involvement of oxygen-sensing pathways in physiologic and pathologic erythropoiesis

Blood ◽  
2009 ◽  
Vol 114 (10) ◽  
pp. 2015-2019 ◽  
Author(s):  
Gregg L. Semenza
Keyword(s):  
Blood Cells ◽  
Tissue Oxygenation ◽  
Hypoxia Inducible Factor ◽  
Α Subunit ◽  
Vhl Gene ◽  
Von Hippel Lindau ◽  
Hypoxia Inducible Factor 1 ◽  
Oxygen Homeostasis ◽  
Genes Encoding ◽  
Asparaginyl Hydroxylase

Abstract Red blood cells deliver O2 from the lungs to every cell in the human body. Reduced tissue oxygenation triggers increased production of erythropoietin by hypoxia-inducible factor 1 (HIF-1), which is a transcriptional activator composed of an O2-regulated α subunit and a constitutively expressed β subunit. Hydroxylation of HIF-1α or HIF-2α by the asparaginyl hydroxylase FIH-1 blocks coactivator binding and transactivation. Hydroxylation of HIF-1α or HIF-2α by the prolyl hydroxylase PHD2 is required for binding of the von Hippel-Lindau protein (VHL), leading to ubiquitination and proteasomal degradation. Mutations in the genes encoding VHL, PHD2, and HIF-2α have been identified in patients with familial erythrocytosis. Patients with Chuvash polycythemia, who are homozygous for a missense mutation in the VHL gene, have multisystem pathology attributable to dysregulated oxygen homeostasis. Intense efforts are under way to identify small molecule hydroxylase inhibitors that can be administered chronically to selectively induce erythropoiesis without undesirable side effects.

scholarly journals Emetine Promotes von Hippel-Lindau-Independent Degradation of Hypoxia-Inducible Factor-2α in Clear Cell Renal Carcinoma

2010 ◽  
Vol 78 (6) ◽  
pp. 1072-1078 ◽  
Author(s):  
Hye-Sik Kong ◽  
Sunmin Lee ◽  
Kristin Beebe ◽  
Bradley Scroggins ◽  
Gopal Gupta ◽  
...  
Keyword(s):  
Renal Carcinoma ◽  
Clear Cell ◽  
Hypoxia Inducible Factor ◽  
Clear Cell Renal Carcinoma ◽  
Von Hippel Lindau ◽  
Cell Renal Carcinoma

scholarly journals Hypoxia-inducible factor–1 and associated upstream and downstream proteins in the pathophysiology and management of glioblastoma

2014 ◽  
Vol 37 (6) ◽  
pp. E8 ◽  
Author(s):  
Matthew Womeldorff ◽  
David Gillespie ◽  
Randy L. Jensen
Keyword(s):  
Cellular Response ◽  
Treatment Options ◽  
Hypoxia Inducible Factor ◽  
Hypoxia Inducible Factor 1 ◽  
Poor Patient ◽  
Growth Development ◽  
The Relationship ◽  
Insight Into ◽  
Upstream Regulators

Glioblastoma multiforme (GBM) is a highly aggressive brain tumor with an exceptionally poor patient outcome despite aggressive therapy including surgery, radiation, and chemotherapy. This aggressive phenotype may be associated with intratumoral hypoxia, which probably plays a key role in GBM tumor growth, development, and angiogenesis. A key regulator of cellular response to hypoxia is the protein hypoxia-inducible factor–1 (HIF-1). An examination of upstream hypoxic and nonhypoxic regulation of HIF-1 as well as a review of the downstream HIF-1–regulated proteins may provide further insight into the role of this transcription factor in GBM pathophysiology. Recent insights into upstream regulators that intimately interact with HIF-1 could provide potential therapeutic targets for treatment of this tumor. The same is potentially true for HIF-1–mediated pathways of glycolysis-, angiogenesis-, and invasion-promoting proteins. Thus, an understanding of the relationship between HIF-1, its upstream protein regulators, and its downstream transcribed genes in GBM pathogenesis could provide future treatment options for the care of patients with these tumors.

Sign in / Sign up

Export Citation Format

Share Document