Enhancement of glycolysis in cardiomyocytes elevates endothelin-1 expression through the transcriptional factor hypoxia-inducible factor-1 α

2002 ◽  
Vol 103 (s2002) ◽  
pp. 210S-214S ◽  
Author(s):  
Yoshihiko KAKINUMA ◽  
Takashi MIYAUCHI ◽  
Takahiko SUZUKI ◽  
Koichi YUKI ◽  
Nobuyuki MURAKOSHI ◽  
...  

We investigated whether the type of energy metabolism directly affects cardiac gene expression. During development, the heart switches from glycolysis to fatty acid β-oxidation in vivo, as demonstrated by the developmental switching of the major isoform of myosin heavy chain (MHC) from β to α. However, the β-MHC isoform predominates in monocrotaline-induced pulmonary hypertension, a model of right ventricular hypertrophy in vivo. Cultured cardiomyocytes showed a predominance of β-MHC expression over that of α-MHC, the same pattern as in the hypertrophied heart, suggesting that the in vitro condition itself causes the energy metabolism of cardiomyocytes to be switched to glycolysis. Electrical stimulation of cultured cardiomyocytes decreased the expression of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and hypoxia-inducible factor-1α (HIF-1α), but not that of peroxisome-proliferator-activated receptor-γ co-activator, suggesting that electrical stimulation suppresses the glycolytic system. Furthermore, a higher oxygen content (50%) decreased drastically the expression of GAPDH, HIF-1α and endothelin-1 (ET-1), and increased [3H]palmitate uptake. These findings indicate that the intrinsic energy metabolic system in cultured cardiomyocytes in vitro is predominantly glycolysis, and that the gene expression of cardiac ET-1 parallels the state of the glycolytic system. An antisense oligonucleotide against HIF-1α greatly decreased the gene expression of ET-1 and GAPDH, suggesting that cardiac ET-1 gene expression is regulated by cardiac energy metabolism through HIF-1α. In conclusion, it is suggested that the pattern of gene expression of ET-1 reflects the level of the glycolytic system in cardiomyocytes, and that enhanced glycolysis regulates the cardiac gene expression of ET-1 via HIF-1α.

1995 ◽  
Vol 752 (1 Cardiac Growt) ◽  
pp. 370-386 ◽  
Author(s):  
J. L. SAMUEL ◽  
I. DUBUS ◽  
F. FARHADIAN ◽  
F. MAROTTE ◽  
P. OLIVIERO ◽  
...  

1999 ◽  
Vol 276 (5) ◽  
pp. R1525-R1533 ◽  
Author(s):  
Xianzhong Meng ◽  
Brian D. Shames ◽  
Edward J. Pulido ◽  
Daniel R. Meldrum ◽  
Lihua Ao ◽  
...  

This study tested the hypothesis that in vivo norepinephrine (NE) treatment induces bimodal cardiac functional protection against ischemia and examined the roles of α1-adrenoceptors, protein kinase C (PKC), and cardiac gene expression in cardiac protection. Rats were treated with NE (25 μg/kg iv). Cardiac functional resistance to ischemia-reperfusion (25/40 min) injury was examined 30 min and 1, 4, and 24 h after NE treatment with the Langendorff technique, and effects of α1-adrenoceptor antagonism and PKC inhibition on the protection were determined. Northern analysis was performed to examine cardiac expression of mRNAs encoding α-actin and myosin heavy chain (MHC) isoforms. Immunofluorescent staining was performed to localize PKC-βI in the ventricular myocardium. NE treatment improved postischemic functional recovery at 30 min, 4 h, and 24 h but not at 1 h. Pretreatment with prazosin or chelerythrine abolished both the early adaptive response at 30 min and the delayed adaptive response at 24 h. NE treatment induced intranuclear translocation of PKC-βI in cardiac myocytes at 10 min and increased skeletal α-actin and β-MHC mRNAs in the myocardium at 4–24 h. These results demonstrate that in vivo NE treatment induces bimodal myocardial functional adaptation to ischemia in a rat model. α1-Adrenoceptors and PKC appear to be involved in signal transduction for inducing both the early and delayed adaptive responses. The delayed adaptive response is associated with the expression of cardiac genes encoding fetal contractile proteins, and PKC-βI may transduce the signal for reprogramming of cardiac gene expression.


2001 ◽  
Vol 280 (5) ◽  
pp. H2046-H2052 ◽  
Author(s):  
Markus Meyer ◽  
Susanne U. Trost ◽  
Wolfgang F. Bluhm ◽  
Harm J. Knot ◽  
Eric Swanson ◽  
...  

Sarcoplasmic reticulum (SR)-mediated Ca2+ sequestration and release are important determinants of cardiac contractility. In end-stage heart failure SR dysfunction has been proposed to contribute to the impaired cardiac performance. In this study we tested the hypothesis that a targeted interference with SR function can be a primary cause of contractile impairment that in turn might alter cardiac gene expression and induce cardiac hypertrophy. To study this we developed a novel animal model in which ryanodine, a substance that alters SR Ca2+ release, was added to the drinking water of mice. After 1 wk of treatment, in vivo hemodynamic measurements showed a 28% reduction in the maximum speed of contraction (+dP/d t max) and a 24% reduction in the maximum speed of relaxation (−dP/d t max). The slowing of cardiac relaxation was confirmed in isolated papillary muscles. The late phase of relaxation expressed as the time from 50% to 90% relaxation was prolonged by 22%. After 4 wk of ryanodine administration the animals had developed a significant cardiac hypertrophy that was most prominent in both atria (right artrium +115%, left atrium +100%, right ventricle +23%, and left ventricle +13%). This was accompanied by molecular changes including a threefold increase in atrial natriuretic factor mRNA and a sixfold increase in β-myosin heavy chain mRNA. Sarcoplasmic endoplasmic reticulum Ca2+ mRNA was reduced by 18%. These data suggest that selective impairment of SR function in vivo can induce changes in cardiac gene expression and promote cardiac growth.


2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Liang Ji ◽  
Xiaoyu Guo ◽  
Jiachen Lv ◽  
Fan Xiao ◽  
Wangjun Zhang ◽  
...  

The present study was conducted to investigate the effect and potential mechanism of hypoxia-inducible factor-1α (HIF-1α) genetic inhibition plus glutamine (Gln) supplementation on necrosis-apoptosis imbalance during acute pancreatitis (AP), with a specific focus on the regulations of intracellular energy metabolism status. Wistar rats and AR42J cells were used to establish AP models. When indicated, a HIF-1α knockdown with or without a Gln supplementation was administered. In vivo, local and systemic inflammatory injuries were assessed by serum cytokine measurement, H&E staining, and transmission electron microscope (TEM) observation of pancreatic tissue. In vitro, intracellular energy metabolism status was evaluated by measuring the intracellular adenosine triphosphate (ATP), lactic acid, and Ca2+ concentrations and the mitochondrial potential. In addition, changes in the apoptotic activity were analyzed using TUNEL staining in vivo and an apoptosis assay in vitro. HIF-1α knockdown alleviated AP-related inflammatory injury as indicated by the measurements of serum cytokines and examinations of TEM and H&E staining of pancreatic tissues. HIF-1α knockdown played an antioxidative role against AP-related injuries by preventing the increase in the intracellular Ca2+ concentration and the decrease in the mitochondrial membrane potential and subsequently by suppressing the glycolysis pathway and increasing energy anabolism in AR42J cells after AP induction. Apoptosis was significantly upregulated when HIF-1α was knocked down before AP induction due to an attenuation of the translocation of nuclear factor-kappa B to the nuclei. Furthermore, these merits of HIF-1α knockdown in the relief of the metabolic stress and upregulation of apoptosis were more significant when Gln was administered concomitantly. In conclusion, Gln-supplemented HIF-1α knockdown might be promising for the future management of AP by relieving the intracellular energy stress, thereby attenuating the predominance of necrosis over apoptosis.


2006 ◽  
Vol 291 (2) ◽  
pp. H600-H611 ◽  
Author(s):  
Anthony Azakie ◽  
Jeffrey R. Fineman ◽  
Youping He

Combinatorial interactions between cis elements and trans-acting factors are required for regulation of cardiac gene expression during normal cardiac development and pathological cardiac hypertrophy. Sp factors bind GC boxes and are implicated in recruitment and assembly of the basal transcriptional complex. In this study, we show that the cardiac troponin T (cTnT) promoter contains a GC box that is necessary for basal and cAMP-mediated activity of cTnT promoter constructs transfected in embryonic cardiomyocytes. Cardiac nuclear proteins bind the cTnT GC box in a sequence-specific fashion and consist of Sp1, Sp2, and Sp3 protein factors. By chromatin immunoprecipitation, Sp1 binds the cTnT promoter “in vivo.” Cotransfected Sp1 trans-activates the cTnT promoter in cardiomyocytes in culture. Sp3 represses Sp1-mediated transcriptional activation of the cTnT gene in embryonic cardiomyocytes. Sp3 repression of Sp1-mediated cTnT promoter activation is dose dependent, inferring a mechanism of competitive binding/inhibition. To evaluate the role of Sp factors in cardiac gene expression in vivo, we have established a clinically relevant animal model of pathological cardiac hypertrophy where the fetal cardiac program is activated. In this animal model, cardiac hypertrophy results from increased left-right shunting, volume loading of the left ventricle, and pressure loading of the right ventricle. Sp1 expression is increased in all four hypertrophied cardiac chambers, whereas Sp3 expression is diminished. This observation is consistent with the in vitro activating function of Sp1 and inhibitory effects of Sp3 on activity of cTnT promoter constructs. Sp factor levels are modulated during the hypertrophic cardiac program in vivo.


Blood ◽  
2005 ◽  
Vol 105 (8) ◽  
pp. 3133-3140 ◽  
Author(s):  
Marzia Scortegagna ◽  
Kan Ding ◽  
Quiyang Zhang ◽  
Yavuz Oktay ◽  
Michael J. Bennett ◽  
...  

AbstractErythropoiesis in the adult mammal depends critically on erythropoietin, an inducible cytokine with pluripotent effects. Erythropoietin gene expression increases under conditions associated with lowered oxygen content such as anemia and hypoxia. HIF-1α, the founding member of the hypoxia-inducible factor (HIF) alpha class, was identified by its ability to bind and activate the hypoxia-responsive enhancer in the erythropoietin regulatory region in vitro. The existence of multiple HIF alpha members raises the question of which HIF alpha member or members regulates erythropoietin expression in vivo. We previously reported that mice lacking wild-type HIF-2α, encoded by the EPAS1 gene, exhibit pancytopenia. In this study, we have characterized the etiology of this hematopoietic phenotype. Molecular studies of EPAS1-null kidneys reveal dramatically decreased erythropoietin gene expression. EPAS1-null as well as heterozygous mice have impaired renal erythropoietin induction in response to hypoxia. Treatment of EPAS1-null mice with exogenous erythropoietin reverses the hematopoietic and other defects. We propose that HIF-2α is an essential regulator of murine erythropoietin production. Impairments in HIF signaling, involving either HIF-1α or HIF-2α, may play a prominent role in conditions involving altered hematopoietic or erythropoietin homeostasis.


2010 ◽  
Vol 298 (3) ◽  
pp. R661-R671 ◽  
Author(s):  
Tomoharu Tanaka ◽  
Takuhiko Wakamatsu ◽  
Hiroki Daijo ◽  
Seiko Oda ◽  
Shinichi Kai ◽  
...  

The transcription factor hypoxia-inducible factor-1 (HIF-1) plays an essential role in regulating gene expression in response to hypoxia-ischemia. Ischemia causes the tissue not only to be hypoxic but also to be hypothermic because of the hypoperfusion under certain circumstances. On the other hand, the induced hypothermia is one of the most common therapeutic modalities to extend tolerance to hypoxia. Although hypoxia elicits a variety of cellular and systemic responses at different organizational levels in the body, little is known about how hypoxia-induced responses are affected by low temperature. We examined the influence of mild hypothermic conditions (28–32°C) on HIF-1 in both in vitro and in vivo settings. In vitro experiments adopting cultured cells elucidated that hypoxia-induced HIF-1 activation was resistant to 4-h exposure to the low temperature. In contrast, exposure to the low temperature as long as 24 h suppressed HIF-1 activation and the subsequent upregulation of HIF-1 target genes such as VEGF or GLUT-1. HIF-1α protein stability in the cell was not affected by hypothermic treatment. Furthermore, intracellular ATP content was reduced under 1% O2 conditions but was not largely affected by hypothermic treatment. The evidence indicates that reduction of oxygen consumption is not largely involved in suppression of HIF-1. In addition, we demonstrated that HIF-1 DNA-binding activity and HIF-1-dependent gene expressions induced under 10% O2 atmosphere in mouse brain were not influenced by treatment under 3-h hypothermic temperature but were inhibited under 5-h treatment. On the other hand, we indicated that warming ischemic legs of mice for 24 h preserved HIF-1 activity. In this report we describe for the first time that persisting low temperature significantly reduced HIF-1α neosynthesis under hypoxic conditions, leading to a decrease in gene expression for adaptation to hypoxia in both in vitro and in vivo settings.


2021 ◽  
Author(s):  
Wentong Fang ◽  
Chengheng Liao ◽  
Rachel Shi ◽  
Jeremy Simon ◽  
Travis Ptacek ◽  
...  

Triple-negative breast cancer (TNBC) is an aggressive and highly lethal disease, which warrants the critical need to identify new therapeutic targets. We show that Zinc Fingers And Homeoboxes 2 (ZHX2) is amplified or overexpressed in TNBC cell lines and patients. Functionally, depletion of ZHX2 inhibited TNBC cell growth and invasion in vitro, orthotopic tumor growth and spontaneous lung metastasis in vivo. Mechanistically, ZHX2 bound with hypoxia inducible factor (HIF) family members and positively regulated HIF1α activity in TNBC. Integrated ChIP-Seq and gene expression profiling demonstrated that ZHX2 co-occupied with HIF1α on transcriptionally active promoters marked by H3K4me3 and H3K27ac, thereby promoting gene expression. Furthermore, multiple residues (R491, R581 and R674) on ZHX2 are important in regulating its phenotype, which correspond with their roles on controlling HIF1α activity in TNBC cells. These studies establish that ZHX2 activates oncogenic HIF1α signaling, therefore serving as a potential therapeutic target for TNBC.


Sign in / Sign up

Export Citation Format

Share Document