FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2559379243> ?p ?o ?g. }

• W2559379243 endingPage "627" @default.
• W2559379243 startingPage "616" @default.
• W2559379243 abstract "Chronic kidney disease (CKD) is associated with increased risk and worse prognosis of cardiovascular disease, including peripheral artery disease. An impaired angiogenic response to ischemia may contribute to poor outcomes of peripheral artery disease in patients with CKD. Hypoxia inducible factors (HIF) are master regulators of angiogenesis and therefore represent a promising target for therapeutic intervention. To test this we induced hind-limb ischemia in rats with CKD caused by 5/6 nephrectomy and administered two different treatments known to stabilize HIF protein in vivo: carbon monoxide and a pharmacological inhibitor of prolyl hydroxylation 2-(1-chloro-4- hydroxyisoquinoline-3-carboxamido) acetate (ICA). Expression levels of pro-angiogenic HIF target genes (Vegf, Vegf-r1, Vegf-r2, Ho-1) were measured by qRT-PCR. Capillary density was measured by CD31 immunofluorescence staining and HIF expression was evaluated by immunohistochemistry. Capillary density in ischemic skeletal muscle was significantly lower in CKD animals compared to sham controls. Rats with CKD showed significantly lower expression of HIF and all measured pro-angiogenic HIF target genes, including VEGF. Both HIF stabilizing treatments rescued HIF target gene expression in animals with CKD and led to significantly higher ischemia-induced capillary sprouting compared to untreated controls. ICA was effective regardless of whether it was administered before or after induction of ischemia and led to a HIF expression in skeletal muscle. Thus, impaired ischemia-induced angiogenesis in rats with CKD can be improved by HIF stabilization, even if started after onset of ischemia. Chronic kidney disease (CKD) is associated with increased risk and worse prognosis of cardiovascular disease, including peripheral artery disease. An impaired angiogenic response to ischemia may contribute to poor outcomes of peripheral artery disease in patients with CKD. Hypoxia inducible factors (HIF) are master regulators of angiogenesis and therefore represent a promising target for therapeutic intervention. To test this we induced hind-limb ischemia in rats with CKD caused by 5/6 nephrectomy and administered two different treatments known to stabilize HIF protein in vivo: carbon monoxide and a pharmacological inhibitor of prolyl hydroxylation 2-(1-chloro-4- hydroxyisoquinoline-3-carboxamido) acetate (ICA). Expression levels of pro-angiogenic HIF target genes (Vegf, Vegf-r1, Vegf-r2, Ho-1) were measured by qRT-PCR. Capillary density was measured by CD31 immunofluorescence staining and HIF expression was evaluated by immunohistochemistry. Capillary density in ischemic skeletal muscle was significantly lower in CKD animals compared to sham controls. Rats with CKD showed significantly lower expression of HIF and all measured pro-angiogenic HIF target genes, including VEGF. Both HIF stabilizing treatments rescued HIF target gene expression in animals with CKD and led to significantly higher ischemia-induced capillary sprouting compared to untreated controls. ICA was effective regardless of whether it was administered before or after induction of ischemia and led to a HIF expression in skeletal muscle. Thus, impaired ischemia-induced angiogenesis in rats with CKD can be improved by HIF stabilization, even if started after onset of ischemia. Chronic kidney disease (CKD) is a growing health burden worldwide.1Coresh J. Selvin E. Stevens L.A. et al.Prevalence of chronic kidney disease in the United States.JAMA. 2007; 298: 2038-2047Crossref PubMed Scopus (3892) Google Scholar, 2Nagata M. Ninomiya T. Doi Y. et al.Trends in the prevalence of chronic kidney disease and its risk factors in a general Japanese population: the Hisayama Study.Nephrol Dial Transplant. 2010; 25: 2557-2564Crossref PubMed Scopus (96) Google Scholar, 3Eckardt K.U. Coresh J. Devuyst O. et al.Evolving importance of kidney disease: from subspecialty to global health burden.Lancet. 2013; 382: 158-169Abstract Full Text Full Text PDF PubMed Scopus (746) Google Scholar Premature cardiovascular disease accompanies even early stages of CKD and leads to increased mortality among CKD-patients.4Di Angelantonio E. Chowdhury R. Sarwar N. et al.Chronic kidney disease and risk of major cardiovascular disease and non-vascular mortality: prospective population based cohort study.BMJ. 2010; 341: c4986Crossref PubMed Scopus (212) Google Scholar Among these cardiovascular comorbidities in CKD, peripheral arterial disease (PAD) plays an important role.5Wattanakit K. Folsom A.R. Selvin E. et al.Kidney function and risk of peripheral arterial disease: results from the Atherosclerosis Risk in Communities (ARIC) Study.J Amer Soc Nephrol. 2007; 18: 629-636Crossref PubMed Scopus (180) Google Scholar Sprouting of new capillaries (angiogenesis) is an important compensatory mechanism when stenosis or occlusion of large arteries restricts blood supply (ischemia) and oxygen supply (hypoxia).6Semenza G.L. Vasculogenesis, angiogenesis, and arteriogenesis: mechanisms of blood vessel formation and remodeling.J Cell Biochem. 2007; 102: 840-847Crossref PubMed Scopus (230) Google Scholar This mechanism appears to be impaired in CKD.7Choi J.H. Kim K.L. Huh W. et al.Decreased number and impaired angiogenic function of endothelial progenitor cells in patients with chronic renal failure.Arterioscler Thromb Vasc Biol. 2004; 24: 1246-1252Crossref PubMed Scopus (297) Google Scholar, 8Di Marco G.S. Reuter S. Hillebrand U. et al.The soluble VEGF receptor sFlt1 contributes to endothelial dysfunction in CKD.J Amer Soc Nephrol. 2009; 20: 2235-2245Crossref PubMed Scopus (144) Google Scholar Stimulating hypoxia inducible factors (HIFs) represents a promising concept to improve angiogenesis because HIFs are master transcriptional regulators of a protective response to hypoxia.9Maxwell P.H. Ratcliffe P.J. Oxygen sensors and angiogenesis.Semin Cell Dev Biol. 2002; 13: 29-37Crossref PubMed Scopus (290) Google Scholar HIF target genes include VEGF and its receptors, as well as hemoxygenase-1 (HO-1)10Lee P.J. Jiang B.H. Chin B.Y. et al.Hypoxia-inducible factor-1 mediates transcriptional activation of the heme oxygenase-1 gene in response to hypoxia.J Biol Chem. 1997; 272: 5375-5381Crossref PubMed Scopus (651) Google Scholar, 11Tuder R.M. Flook B.E. Voelkel N.F. Increased gene expression for VEGF and the VEGF receptors KDR/Flk and Flt in lungs exposed to acute or to chronic hypoxia. Modulation of gene expression by nitric oxide.J Clin Invest. 1995; 95: 1798-1807Crossref PubMed Scopus (532) Google Scholar which are all crucial for vessel formation.12Dulak J. Loboda A. Zagorska A. et al.Complex role of heme oxygenase-1 in angiogenesis.Antioxid Redox Signal. 2004; 6: 858-866Crossref PubMed Scopus (77) Google Scholar There is some evidence that CKD may cause HIF downregulation and disturbed HIF dependent signaling.13Flisinski M. Brymora A. Bartlomiejczyk I. et al.Decreased hypoxia-inducible factor-1alpha in gastrocnemius muscle in rats with chronic kidney disease.Kidney Blood Press Res. 2012; 35: 608-618Crossref PubMed Scopus (18) Google Scholar, 14Chiang C.K. Tanaka T. Inagi R. et al.Indoxyl sulfate, a representative uremic toxin, suppresses erythropoietin production in a HIF-dependent manner.Lab Invest. 2011; 91: 1564-1571Crossref PubMed Scopus (119) Google Scholar, 15Asai H. Hirata J. Hirano A. et al.Activation of aryl hydrocarbon receptor mediates suppression of hypoxia inducible factor-dependent erythropoietin expression by indoxyl sulfate.Am J Physiol Cell Physiol. 2016; 310: C142-C150PubMed Google Scholar An in vivo model revealed that ischemia does not prompt upregulation of pro-angiogenetic genes in CKD animals.16Jacobi J. Porst M. Cordasic N. et al.Subtotal nephrectomy impairs ischemia-induced angiogenesis and hindlimb re-perfusion in rats.Kidney Int. 2006; 69: 2013-2021Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar Furthermore, CKD patients exhibit elevated plasma levels of anti-angiogenetic factors, such as endostatin.17Futrakul N. Butthep P. Laohareungpanya N. et al.A defective angiogenesis in chronic kidney disease.Ren Fail. 2008; 30: 215-217Crossref PubMed Scopus (45) Google Scholar Animal models confirmed that HIF upregulation via viral vectors or transgenic overexpression can promote angiogenesis without systemic VEGF-induced side effects.18Kido M. Du L. Sullivan C.C. et al.Hypoxia-inducible factor 1-alpha reduces infarction and attenuates progression of cardiac dysfunction after myocardial infarction in the mouse.J Am Coll Cardiol. 2005; 46: 2116-2124Abstract Full Text Full Text PDF PubMed Scopus (266) Google Scholar, 19Patel T.H. Kimura H. Weiss C.R. et al.Constitutively active HIF-1alpha improves perfusion and arterial remodeling in an endovascular model of limb ischemia.Cardiovasc Res. 2005; 68: 144-154Crossref PubMed Scopus (125) Google Scholar, 20Pajusola K. Kunnapuu J. Vuorikoski S. et al.Stabilized HIF-1alpha is superior to VEGF for angiogenesis in skeletal muscle via adeno-associated virus gene transfer.FASEB J. 2005; 19: 1365-1367PubMed Google Scholar Prolyl hydroxylase inhibitors provide a pharmacological approach to stabilize HIF. Such compounds are in clinical trials for the treatment of renal anemia.21Holdstock L. Meadowcroft A.M. Maier R. et al.Four-week studies of oral hypoxia-inducible factor-prolyl hydroxylase inhibitor GSK1278863 for treatment of anemia.J Am Soc Nephrol. 2016; 27: 1234-1244Crossref PubMed Scopus (146) Google Scholar, 22Besarab A. Chernyavskaya E. Motylev I. et al.Roxadustat (FG-4592): correction of anemia in incident dialysis patients.J Am Soc Nephrol. 2016; 27: 1225-1233Crossref PubMed Scopus (187) Google Scholar, 23Bernhardt W.M. Wiesener M.S. Scigalla P. et al.Inhibition of prolyl hydroxylases increases erythropoietin production in ESRD.J Am Soc Nephrol. 2010; 21: 2151-2156Crossref PubMed Scopus (270) Google Scholar, 24Maxwell P.H. Eckardt K.U. HIF prolyl hydroxylase inhibitors for the treatment of renal anaemia and beyond.Na Rev Nephrol. 2016; 12: 157-168Crossref PubMed Scopus (182) Google Scholar In animal models, deficiency or pharmacological inhibition of PHD improved angiogenesis, especially in the setting of acute ischemia.25Nangaku M. Izuhara Y. Takizawa S. et al.A novel class of prolyl hydroxylase inhibitors induces angiogenesis and exerts organ protection against ischemia.Arterioscler Thromb Vasc Biol. 2007; 27: 2548-2554Crossref PubMed Scopus (103) Google Scholar, 26Warnecke C. Griethe W. Weidemann A. et al.Activation of the hypoxia-inducible factor-pathway and stimulation of angiogenesis by application of prolyl hydroxylase inhibitors.FASEB J. 2003; 17: 1186-1188Crossref PubMed Scopus (185) Google Scholar, 27Vogler M. Zieseniss A. Hesse A.R. et al.Pre- and post-conditional inhibition of prolyl-4-hydroxylase domain enzymes protects the heart from an ischemic insult.Pflugers Arch. 2015; 467: 2141-2149Crossref PubMed Scopus (31) Google Scholar, 28Aragones J. Schneider M. Van Geyte K. et al.Deficiency or inhibition of oxygen sensor Phd1 induces hypoxia tolerance by reprogramming basal metabolism.Nat Genet. 2008; 40: 170-180Crossref PubMed Scopus (390) Google Scholar However, the effects of PHD inhibitors on angiogenesis in the presence of CKD remain unknown. We therefore tested the hypothesis that HIF stabilization in CKD animals before or after the onset of hind-limb ischemia would improve ischemia-induced angiogenesis. Two different methods of HIF stabilization were used: carbon monoxide (CO) administration, which induces the hypoxia-response by blocking oxygen transport capacity, and a recently described pharmacological inhibitor of HIF degradation, 2-(1-chloro-4-hydroxyisoquinoline-3-carboxamido) acetate (ICA).29Schley G. Klanke B. Schodel J. et al.Selective stabilization of HIF-1alpha in renal tubular cells by 2-oxoglutarate analogues.Amer J Pathol. 2012; 181: 1595-1606Abstract Full Text Full Text PDF PubMed Scopus (34) Google Scholar We hypothesized that a short, transient HIF stabilization at the time of ischemia induction could exert a lasting beneficial effect on capillary supply because the most important angiogenesis-related genes peak very early after hind-limb ischemia.30Paoni N.F. Peale F. Wang F. et al.Time course of skeletal muscle repair and gene expression following acute hind limb ischemia in mice.Physiol Genomics. 2002; 11: 263-272Crossref PubMed Scopus (93) Google Scholar, 31Lee C.W. Stabile E. Kinnaird T. et al.Temporal patterns of gene expression after acute hindlimb ischemia in mice: insights into the genomic program for collateral vessel development.J Amer Coll Cardiol. 2004; 43: 474-482Abstract Full Text Full Text PDF PubMed Scopus (116) Google Scholar Male rats were used to explore angiogenesis (capillary sprouting) in a model of CKD. CKD was induced by removing 5/6 of total kidney mass (5/6 nephrectomy model / ablation model). Eight weeks later, unilateral hind-limb ischemia was induced by femoral artery ligation and the effects on angiogenesis were studied. In the nonischemic limbs we could not find differences of capillary density as determined by CD31 staining (Figure 1a and b) between sham-operated rats with normal kidney function (SHAM) and subtotally nephrectomized rats with impaired kidney function (SNX), suggesting that CKD in this setting had no effect on vascularization at baseline. In the affected ischemic limbs, capillary density significantly increased (by ∼53%) in SHAM animals but not in SNX animals. In fact, in SNX there was no difference between the ischemic limb and the contralateral site, indicating that the angiogenic response was completely blunted (Figure 1b). We next hypothesized that insufficient capillary sprouting after ischemia in rats with renal impairment might be related to impaired HIF-dependent signaling. Thus, we performed immunohistochemical stainings for HIF1a in skeletal muscle of SHAM and SNX rats. HIF1a expression was significantly upregulated in ischemic versus nonischemic skeletal muscles in SHAM operated rats. In contrast, HIF expression was not different between ischemic and nonischemic limbs in SNX animals (Figure 2). To test whether impaired HIF expression in ischemic limbs of SNX rats might be susceptible to HIF inducing treatment, we first verified the HIF inducing properties of our pharmacological treatment regime by comparing HIF protein expression in endothelial cells (ECs32Heffelfinger S.C. Hawkins H.H. Barrish J. et al.SK HEP-1: a human cell line of endothelial origin.In Vitro Cell Dev Biol. 1992; 28A: 136-142Crossref PubMed Scopus (131) Google Scholar) incubated with ICA to ECs that were grown under control (ctrl) or hypoxic (hyp) conditions or incubated with the hypoxia mimetic 2,2-Dipyridyl (DP),33Martens L.K. Kirschner K.M. Warnecke C. et al.Hypoxia-inducible factor-1 (HIF-1) is a transcriptional activator of the TrkB neurotrophin receptor gene.J Biol Chem. 2007; 282: 14379-14388Crossref PubMed Scopus (68) Google Scholar an iron chelator and PHD-inhibitor,34Li S. Crooks P.A. Wei X. et al.Toxicity of dipyridyl compounds and related compounds.Crit Rev Toxicol. 2004; 34: 447-460Crossref PubMed Scopus (34) Google Scholar that served as a positive control (Figure 3). Immunoblot analyses revealed a high abundance of both HIF-1α and HIF-2α after 6 and 24 hours (h) of exposure to ICA, hypoxia, or DP (Figure 3). We next tested effects of CO and ICA as a preventive approach in SNX rats. Animals were either housed in special cages for 6 hours and ventilated with room air supplemented with 0.1% CO or received 2 injections of ICA (12.5 mg/kg body weight, dissolved in 10% DMSO in 0.5M TRIS, pH = 9,) 24 hours before induction of hind-limb ischemia (pre-ischemic treatment). At 24 hours after induction of ischemia, mRNA expression levels of the pro-angiogenic HIF target genes Vegf, Vegf-r1, Vegfr-r2, and Ho-1 were measured via qRT-PCR. Gene expression levels were significantly lower in ischemic muscle of rats with renal impairment (Figure 4a–d). Treatment with either CO or ICA rescued HIF target gene expression to levels similar as in sham-operated control animals (Figure 4a–d). We did not detect any differences in mRNA expression levels of HIF target genes in nonischemic limbs (data not shown). In order to investigate whether the upregulation of pro-angiogenic HIF target genes via preventive HIF-stabilizing treatment in subtotally nephrectomized rats translates into an increase in angiogenesis, we measured capillary density 2 weeks after femoral artery ligation in skeletal muscle. Capillary density in ischemic muscle almost doubled in both treatment groups (CO, ICA-pre) compared to untreated animals with renal impairment while the capillary density in nonischemic limbs did not differ between the groups (Figure 5). As a next step, we investigated a post-ischemic—as opposed to a pre-ischemic—approach of HIF stabilization. To this end, rats received 2 ICA injections 2 and 6 hours after induction of hind-limb ischemia. HIF target-genes were measured via qRT-PCR. Vegf, Vegf-r1 and Vegf-r2 mRNA expression rose significantly in rats with renal impairment after post-ischemic ICA treatment (ICA-post, Figure 6a–d). Similar to what we observed in the pre-ischemic approach, the rise in mRNA expression levels of pro-angiogenic genes was associated with a significant increase of capillary density in ischemic limbs of ICA treated animals with renal impairment compared with untreated animals with renal impairment, while the capillary density in nonischemic limbs did not differ between the groups, and the rise in capillary density in sham-treated animals was also unaffected (Figure 7). In order to illustrate the mechanisms behind the pro-angiogenic effects of ICA treatment we used immunohistochemistry to evaluate HIF expression in the skeletal muscle of SHAM, SNX, and SNX with post-ischemic ICA treatment. We were able to show compensatory HIF upregulation 24 hours after ischemia induction in ischemic limbs of SHAM operated animals, while this compensatory mechanism was abolished under SNX conditions. After applying ICA treatment, compensatory HIF upregulation could be restored in ischemic limbs of SNX animals (Figure 8). In a next step we sought to investigate the pro-angiogenic mechanisms of ICA treatment. Therefore, we employed an in vitro tube formation assay using human umbilical vein endothelial cells (HUVECs). Tube formation increased after ICA incubation. However, this effect was significantly decreased when VEGF was blocked via a neutralizing antibody (Figure 9). To further explore the potential role of inflammation in our experimental setup, qRT-PCR analysis of inflammatory genes such as Mcp1, Cxcr4, Il6, and Il1b were performed 24 hours after induction of hind-limb ischemia (Figure 10a–e). The measured genes were significantly upregulated in ischemic limbs of all groups (SHAM, SNX, SNX-ICA-post) compared to the respective nonischemic limbs (Figure 10a–d). Furthermore, Mcp1 and Cxcr4 were significantly increased in ischemic limbs of ICA-treated SNX animals compared to untreated SNX animals (Figure 10e). We also analyzed body and organ weight, urinary parameters, and blood parameters of all animals 2 weeks after hind-limb ischemia (Table 1). Body weight and EPO levels did not differ between the groups. Heart weight per body weight ratio increased significantly in SNX animals compared to SHAM. Additionally, as expected, urinary albumin/creatinine ratio, plasma creatinine, as well as plasma urea rose significantly in SNX animals compared to SHAM. CO and ICA treatment of SNX animals did not lower heart weight per body weight ratio, urinary albumin per creatinine ratio, plasma creatinine, or plasma urea. Furthermore, plasma VEGF levels were significantly higher in SNX animals compared with SHAM controls. However, CO and ICA treatment did not significantly alter plasma VEGF levels in SNX animals. Furthermore, hematocrit was significantly lower in rats with kidney impairment than those with normal kidney function and did not show a persistent rise following temporary treatment with ICA (SHAM = 43%, n = 6; SNX = 39%, n = 5; ICA-post = 39%, n = 5).Table 1Body weight, organ weight, renal function parameters 2 weeks after hind-limb ischemiaCharacteristic 2 weeksSHAM (n = 15)SNX (n = 15)SNX + CO (n = 6)SNX + ICA-pre (n = 7)SNX + ICA-post (n = 5)Body weight (g)552 ± 10 (n.s.)565 ± 20513 ± 10 (n.s.)543 ± 10 (n.s.)542 ± 14 (n.s.)Kidney weight/body weight *10003.11 ± 0.11∗2.02 ± 0.091.52 ± 0.08 (n.s.)1.90 ± 0.12 (n.s.)1.95 ± 0.13 (n.s.)Heart weight/body weight *10002.55 ± 0.06∗2.91 ± 0.122.70 ± 0.07 (n.s.)2.91 ± 0.15 (n.s.)2.86 ± 0.25 (n.s.)Urinary Albumin/creatinine0.08 ± 0.02∗9.26 ± 2.086.13 ± 2.78 (n.s.)7.56 ± 3.80 (n.s.)6.47 ± 2.35 (n.s.)Plasma creatinine (mg/dl)0.26 ± 0.02∗0.52 ± 0.040.50 ± 0.02 (n.s.)0.62 ± 0.05 (n.s.)0.53 ± 0.05 (n.s.)Plasma urea (mg/dl)31.2 ± 2.5∗62.6 ± 4.064.0 ± 3.9 (n.s.)75.6 ± 5.6 (n.s.)57.4 ± 6.0 (n.s.)Plasma VEGF (pg/ml)57.2 ± 3.8∗87.7 ± 8.995.1 ± 4.0 (n.s.)108.8 ± 4.8 (n.s.)96.6 ± 8.6 (n.s.)Plasma EPO (pg/ml)18.9 ± 2.2 (n.s.)25.6 ± 4.0--28.6 ± 4.1 (n.s.)Sham-operated animals (SHAM), subtotally nephrectomized animals (SNX), and subtotally nephrectomized animals treated with either CO or the pharmaceutical HIF stabilizer ICA. Values are means ± SEM. One-way ANOVA *P < 0.05 versus SNX. n.s. = not significant versus SNX. Open table in a new tab Sham-operated animals (SHAM), subtotally nephrectomized animals (SNX), and subtotally nephrectomized animals treated with either CO or the pharmaceutical HIF stabilizer ICA. Values are means ± SEM. One-way ANOVA *P < 0.05 versus SNX. n.s. = not significant versus SNX. This study confirms that angiogenesis after limb ischemia is severely reduced in the presence of impaired kidney function, and shows for the first time that this impairment can be overcome by stimulating the HIF system. Importantly, HIF stabilization was not only effective when induced prior to ischemia (pre-conditioning), but also when temporarily induced after the ischemic insult, with sustained effects on capillary density. It is controversial whether capillary rarefaction generally occurs in the presence of CKD.16Jacobi J. Porst M. Cordasic N. et al.Subtotal nephrectomy impairs ischemia-induced angiogenesis and hindlimb re-perfusion in rats.Kidney Int. 2006; 69: 2013-2021Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar, 35Amann K. Neimeier K.A. Schwarz U. et al.Rats with moderate renal failure show capillary deficit in heart but not skeletal muscle.Am J Kidney Dis. 1997; 30: 382-388Abstract Full Text PDF PubMed Scopus (46) Google Scholar, 36Flisinski M. Brymora A. Elminowska-Wenda G. et al.Influence of different stages of experimental chronic kidney disease on rats locomotor and postural skeletal muscles microcirculation.Ren Fail. 2008; 30: 443-451Crossref PubMed Scopus (20) Google Scholar Differences in strain, surgical procedure, and protocol might be responsible for contrasting findings in animal experiments.37Fleck C. Appenroth D. Jonas P. et al.Suitability of 5/6 nephrectomy (5/6NX) for the induction of interstitial renal fibrosis in rats–influence of sex, strain, and surgical procedure.Exp Toxicol Pathol. 2006; 57: 195-205Crossref PubMed Scopus (50) Google Scholar Another major reason might be that capillary density has been evaluated in different organs using different methods.35Amann K. Neimeier K.A. Schwarz U. et al.Rats with moderate renal failure show capillary deficit in heart but not skeletal muscle.Am J Kidney Dis. 1997; 30: 382-388Abstract Full Text PDF PubMed Scopus (46) Google Scholar In our setup, we did not detect differences in capillary density in nonischemic limbs between sham and 5/6 nephrectomized (SNX) rats (Figure 1b). As in previous studies, we did however find a marked reduction in capillary sprouting in ischemic limbs. These findings would suggest that even though there is no general capillary rarefaction in skeletal muscles, the adaptation to ischemia is impaired in CKD, which might also apply to ventricular hypertrophy of the heart.35Amann K. Neimeier K.A. Schwarz U. et al.Rats with moderate renal failure show capillary deficit in heart but not skeletal muscle.Am J Kidney Dis. 1997; 30: 382-388Abstract Full Text PDF PubMed Scopus (46) Google Scholar In our specific model, we observe higher capillary densities in muscles from SHAM animals following induction of hind-limb ischemia. This (compensatory) regulation seems defective under SNX conditions. However, SNX animals do not display decreased capillary density following ischemia induction that would be indicative of capillary rarefication or loss. As such, increased capillary densities following PHD inhibition—exceeding the capillary density under basal nonischemic conditions—may be a result of restored compensatory vascular sprouting as opposed to mere capillary preservation. In line with these findings, other groups have shown that HIF stabilization leads to increased capillary sprouting.26Warnecke C. Griethe W. Weidemann A. et al.Activation of the hypoxia-inducible factor-pathway and stimulation of angiogenesis by application of prolyl hydroxylase inhibitors.FASEB J. 2003; 17: 1186-1188Crossref PubMed Scopus (185) Google Scholar, 38Milkiewicz M. Pugh C.W. Egginton S. Inhibition of endogenous HIF inactivation induces angiogenesis in ischaemic skeletal muscles of mice.J Physiol. 2004; 560: 21-26Crossref PubMed Scopus (122) Google Scholar, 39Shyu K.G. Wang M.T. Wang B.W. et al.Intramyocardial injection of naked DNA encoding HIF-1alpha/VP16 hybrid to enhance angiogenesis in an acute myocardial infarction model in the rat.Cardiovasc Res. 2002; 54: 576-583Crossref PubMed Scopus (168) Google Scholar, 40Vincent K.A. Shyu K.G. Luo Y. et al.Angiogenesis is induced in a rabbit model of hindlimb ischemia by naked DNA encoding an HIF-1alpha/VP16 hybrid transcription factor.Circulation. 2000; 102: 2255-2261Crossref PubMed Scopus (291) Google Scholar Furthermore, our data suggest that CKD impairs HIF signaling. In an established rat model of CKD, progression of disease was previously found to cause reduction of HIF and HIF target genes.13Flisinski M. Brymora A. Bartlomiejczyk I. et al.Decreased hypoxia-inducible factor-1alpha in gastrocnemius muscle in rats with chronic kidney disease.Kidney Blood Press Res. 2012; 35: 608-618Crossref PubMed Scopus (18) Google Scholar, 16Jacobi J. Porst M. Cordasic N. et al.Subtotal nephrectomy impairs ischemia-induced angiogenesis and hindlimb re-perfusion in rats.Kidney Int. 2006; 69: 2013-2021Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar In accordance with these studies, we also found that ischemic HIF upregulation in skeletal muscles is impaired in SNX rats (Figure 2). Furthermore, a significantly reduced expression of pro-angiogenic HIF target genes in CKD rats after induction of limb ischemia compared to rats without kidney disease was found (Figure 4a–d). Non-CKD animals and PAD patients without CKD show a rise in HIF and its target genes after ischemia,16Jacobi J. Porst M. Cordasic N. et al.Subtotal nephrectomy impairs ischemia-induced angiogenesis and hindlimb re-perfusion in rats.Kidney Int. 2006; 69: 2013-2021Abstract Full Text Full Text PDF PubMed Scopus (52) Google Scholar, 41Tuomisto T.T. Rissanen T.T. Vajanto I. et al.HIF-VEGF-VEGFR-2, TNF-alpha and IGF pathways are upregulated in critical human skeletal muscle ischemia as studied with DNA array.Atherosclerosis. 2004; 174: 111-120Abstract Full Text Full Text PDF PubMed Scopus (89) Google Scholar, 42Jurgensen J.S. Rosenberger C. Wiesener M.S. et al.Persistent induction of HIF-1alpha and -2alpha in cardiomyocytes and stromal cells of ischemic myocardium.FASEB J. 2004; 18: 1415-1417PubMed Google Scholar and this rise appears to be impaired in the presence of CKD. The main finding of our study is that both pre-ischemic and post-ischemic HIF stabilizing treatments increase HIF protein expression and almost completely rescued defective HIF target gene expression in ischemic limbs of CKD rats (Figure 4). In accordance with these effects on gene expression, treatment with either CO or ICA to stabilize HIF was able to rescue deficient capillary sprouting in CKD animals (Figure 5). Our findings are in line with previous reports showing pro-angiogenic properties of HIF stabilization in other ischemic disease models (e.g., myocardial infarction) with healthy renal function.25Nangaku M. Izuhara Y. Takizawa S. et al.A novel class of prolyl hydroxylase inhibitors induces angiogenesis and exerts organ protection against ischemia.Arterioscler Thromb Vasc Biol. 2007; 27: 2548-2554Crossref PubMed Scopus (103) Google Scholar, 43Philipp S. Jurgensen J.S. Fielitz J. et al.Stabilization of hypoxia inducible factor rather than modulation of collagen metabolism improves cardiac function after acute myocardial infarction in rats.Eur J Heart Fail. 2006; 8: 347-354Crossref PubMed Scopus (54) Google Scholar, 44Lijkwan M.A. Hellingman A.A. Bos E.J. et al.Short hairpin RNA gene silencing of prolyl hydroxylase-2 with a minicircle vector improves neovascularization of hindlimb ischemia.Hum Gene Ther. 2014; 25: 41-49Crossref PubMed Scopus (28) Google Scholar We deliberately employed transient, short-term HIF stabilization because the most important molecular events leading to angiogenesis occur very early after the induction of ischemia. This assumption, which underlies the design of our study, is based on several published systematic investigations of the time course of pro-angiogenic gene expression after hind-limb ischemia.30Paoni N.F. Peale F. Wang F. et al.Time course of skeletal muscle repair and gene expression following acute hind limb ischemia in mice.Physiol Genomics. 2002; 11: 263-272Crossref PubMed Scopus (93) Google Scholar, 31Lee C.W. Stabile E. Kinnaird T. et" @default.
• W2559379243 created "2016-12-08" @default.
• W2559379243 creator A5001850213 @default.
• W2559379243 creator A5006335687 @default.
• W2559379243 creator A5008155631 @default.
• W2559379243 creator A5010255326 @default.
• W2559379243 creator A5017960173 @default.
• W2559379243 creator A5019699199 @default.
• W2559379243 creator A5026584082 @default.
• W2559379243 creator A5032990574 @default.
• W2559379243 creator A5041377528 @default.
• W2559379243 creator A5043558247 @default.
• W2559379243 creator A5043869211 @default.
• W2559379243 creator A5051985691 @default.
• W2559379243 creator A5056517510 @default.
• W2559379243 creator A5058198453 @default.
• W2559379243 creator A5066841350 @default.
• W2559379243 creator A5067586270 @default.
• W2559379243 creator A5076491304 @default.
• W2559379243 date "2017-03-01" @default.
• W2559379243 modified "2023-10-17" @default.
• W2559379243 title "Hypoxia inducible factor stabilization improves defective ischemia-induced angiogenesis in a rodent model of chronic kidney disease" @default.
• W2559379243 cites W1545303483 @default.
• W2559379243 cites W1619977460 @default.
• W2559379243 cites W173795208 @default.
• W2559379243 cites W1966968804 @default.
• W2559379243 cites W1971279082 @default.
• W2559379243 cites W1973002697 @default.
• W2559379243 cites W1975519320 @default.
• W2559379243 cites W1975569148 @default.
• W2559379243 cites W1980813714 @default.
• W2559379243 cites W1985703337 @default.
• W2559379243 cites W1991201872 @default.
• W2559379243 cites W1996356693 @default.
• W2559379243 cites W1998522030 @default.
• W2559379243 cites W1998992316 @default.
• W2559379243 cites W2005297392 @default.
• W2559379243 cites W2006226224 @default.
• W2559379243 cites W2009589470 @default.
• W2559379243 cites W2017902734 @default.
• W2559379243 cites W2019497445 @default.
• W2559379243 cites W2020044628 @default.
• W2559379243 cites W2024740314 @default.
• W2559379243 cites W2025174279 @default.
• W2559379243 cites W2032244429 @default.
• W2559379243 cites W2041492515 @default.
• W2559379243 cites W2045516356 @default.
• W2559379243 cites W2066274999 @default.
• W2559379243 cites W2076396596 @default.
• W2559379243 cites W2079844104 @default.
• W2559379243 cites W2081635255 @default.
• W2559379243 cites W2086100170 @default.
• W2559379243 cites W2089583284 @default.
• W2559379243 cites W2093162072 @default.
• W2559379243 cites W2093469848 @default.
• W2559379243 cites W2097960717 @default.
• W2559379243 cites W2100190333 @default.
• W2559379243 cites W2105176807 @default.
• W2559379243 cites W2105230781 @default.
• W2559379243 cites W2111911306 @default.
• W2559379243 cites W2114594794 @default.
• W2559379243 cites W2115038437 @default.
• W2559379243 cites W2117574147 @default.
• W2559379243 cites W2127285490 @default.
• W2559379243 cites W2130925274 @default.
• W2559379243 cites W2135010444 @default.
• W2559379243 cites W2136226581 @default.
• W2559379243 cites W2136732413 @default.
• W2559379243 cites W2143236053 @default.
• W2559379243 cites W2144770608 @default.
• W2559379243 cites W2145613112 @default.
• W2559379243 cites W2145921809 @default.
• W2559379243 cites W2149655433 @default.
• W2559379243 cites W2158821085 @default.
• W2559379243 cites W2166180650 @default.
• W2559379243 cites W2170646136 @default.
• W2559379243 cites W2172177220 @default.
• W2559379243 cites W2178101235 @default.
• W2559379243 cites W2191103386 @default.
• W2559379243 cites W2196686071 @default.
• W2559379243 cites W2206481924 @default.
• W2559379243 cites W2497059924 @default.
• W2559379243 cites W4206582578 @default.
• W2559379243 doi "https://doi.org/10.1016/j.kint.2016.09.028" @default.
• W2559379243 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/27927598" @default.
• W2559379243 hasPublicationYear "2017" @default.
• W2559379243 type Work @default.
• W2559379243 sameAs 2559379243 @default.
• W2559379243 citedByCount "27" @default.
• W2559379243 countsByYear W25593792432017 @default.
• W2559379243 countsByYear W25593792432018 @default.
• W2559379243 countsByYear W25593792432019 @default.
• W2559379243 countsByYear W25593792432020 @default.
• W2559379243 countsByYear W25593792432021 @default.
• W2559379243 countsByYear W25593792432022 @default.
• W2559379243 countsByYear W25593792432023 @default.
• W2559379243 crossrefType "journal-article" @default.
• W2559379243 hasAuthorship W2559379243A5001850213 @default.

• next