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Direct Renin Inhibition with Aliskiren Improves Ischemia-Induced Neovasculogenesis in Diabetic Animals via the SDF-1 Related Mechanism.

Chang TT, Wu TC, Huang PH, Lin CP, Chen JS, Lin LY, Lin SJ, Chen JW - PLoS ONE (2015)

Bottom Line: Given that angiogenesis is impaired in the presence of diabetes mellitus, we would like to investigate whether and how aliskiren enhances endothelial progenitor cells (EPCs) and improves ischemic-induced neovasculogenesis by an effect independent of blood pressure reduction in diabetic animals.Laser Doppler imaging and flow cytometry were used to evaluate the degree of neovasculogenesis and the circulating levels of EPCs, respectively.Intraperitoneal administration of anti-SDF-1 neutralizing monoclonal antibodies abolished the effects of aliskiren.

View Article: PubMed Central - PubMed

Affiliation: Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan, R.O.C.

ABSTRACT

Objective: Aliskiren is a direct renin inhibitor which is suggested to modify proangiogenic cells in addition to lower blood pressure. Given that angiogenesis is impaired in the presence of diabetes mellitus, we would like to investigate whether and how aliskiren enhances endothelial progenitor cells (EPCs) and improves ischemic-induced neovasculogenesis by an effect independent of blood pressure reduction in diabetic animals.

Methods: Streptozotocin-induced diabetic mice were administered with either aliskiren (5 or 25 mg/kg/day) using an osmotic pump or hydralazine (2 or 10 mg/kg/day) given in drinking water for two weeks prior to a hind-limb ischemia surgery. Laser Doppler imaging and flow cytometry were used to evaluate the degree of neovasculogenesis and the circulating levels of EPCs, respectively.

Results: In streptozotocin-induced diabetic mice, aliskiren enhanced the recovery of limb perfusion and capillary density, increased the number of circulating Sca-1+/Flk-1+ EPC-like cells, and elevated the levels of the plasma vascular endothelial growth factor (VEGF) and stromal cell-derived factor (SDF)-1α in a dose-dependent manner, whereas there were no such effects in hydralazine-treated mice. Intraperitoneal administration of anti-SDF-1 neutralizing monoclonal antibodies abolished the effects of aliskiren.

Conclusions: Independent of the reduction of blood pressure, aliskiren enhanced ischemia-induced neovasculogenesis in a dose-dependent manner via VEGF/SDF-1α related mechanisms in diabetic mice.

No MeSH data available.


Related in: MedlinePlus

Differential effects of aliskiren and hydralazine on protein and mRNA expressions in index thigh muscles in diabetic mice with hindlimb ischemia.Western blots of HIF-1, VEGF, SDF-1α, and actin (n = 6; A). The individual expression of HIF-1, VEGF and SDF-1α was increased in aliskiren (5 or 25 mg/kg/day) treated group (n = 6; B, C, D). (P)RR expressions were also enhanced in aliskiren-treated groups (n = 6; E). However, the expression of p-eNOS was not changed by aliskiren (n = 6; F). Quantitative RT-PCR for the effects of aliskiren on mRNA expressions in thigh muscles in diabetic mice with hindlimb ischemia (n = 6; G). N represents thigh muscles from n different individuals, and thigh muscles from each individual were experimented for 3 independent experiments. C represents untreated diabetic mice (vehicle (PBS)-treated mice); AL represents aliskiren in low dose (5 mg/kg/day); AH represents aliskiren in high dose (25 mg/kg/day); HL represents hydralazine in low dose (2 mg/kg/day); HH represents hydralazine in high dose (10 mg/kg/day). Statistical analysis was done by unpaired Student’s t test or analysis of variance, followed by Scheffe’s multiple-comparison post hoc test. A p value of <0.05 was considered statistically significant. *p < 0.05, **p < 0.01 compared with untreated diabetic mice (vehicle (PBS)-treated mice).
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pone.0136627.g003: Differential effects of aliskiren and hydralazine on protein and mRNA expressions in index thigh muscles in diabetic mice with hindlimb ischemia.Western blots of HIF-1, VEGF, SDF-1α, and actin (n = 6; A). The individual expression of HIF-1, VEGF and SDF-1α was increased in aliskiren (5 or 25 mg/kg/day) treated group (n = 6; B, C, D). (P)RR expressions were also enhanced in aliskiren-treated groups (n = 6; E). However, the expression of p-eNOS was not changed by aliskiren (n = 6; F). Quantitative RT-PCR for the effects of aliskiren on mRNA expressions in thigh muscles in diabetic mice with hindlimb ischemia (n = 6; G). N represents thigh muscles from n different individuals, and thigh muscles from each individual were experimented for 3 independent experiments. C represents untreated diabetic mice (vehicle (PBS)-treated mice); AL represents aliskiren in low dose (5 mg/kg/day); AH represents aliskiren in high dose (25 mg/kg/day); HL represents hydralazine in low dose (2 mg/kg/day); HH represents hydralazine in high dose (10 mg/kg/day). Statistical analysis was done by unpaired Student’s t test or analysis of variance, followed by Scheffe’s multiple-comparison post hoc test. A p value of <0.05 was considered statistically significant. *p < 0.05, **p < 0.01 compared with untreated diabetic mice (vehicle (PBS)-treated mice).

Mentions: Compared with PBS treatment, aliskiren (5 or 25 mg/kg/day) but not hydralazine (2 or 10 mg/kg/day) dose-dependently increased the expression of HIF-1α (Fig 3B) VEGF (Fig 3C), or SDF-1α (Fig 3D). The co-immunoprecipitation analysis also showed that SDF-1 did complex with CXCR4 (S2 Fig). Aliskiren also enhanced (P)RR expression in ischemic limbs compared with untreated diabetic mice (Fig 3E). Neither aliskiren nor hydralazine altered the expression of phosphorylated eNOS (p-eNOS) (Fig 3F). The plasma concentration of nitrite/nitrate was not changed after aliskiren or hydralazine treatments (S3 Fig). We also used L-NAME, an NO inhibitor, to teste whether NO was involved in the aliskiren related mechanism by co-treatment with aliskiren and L-NAME. The results showed that co-treatment with L-NAME do not abolish the beneficial effects of aliskiren on decreased blood pressures and on angiogenesis (S4 Fig). The effects of aliskiren on mRNA expressions in thigh muscles in diabetic mice with hindlimb ischemia were also confirmed by quantitative RT-PCR. Aiskiren dose-dependently increased the mRNA expression of HIF-1α, VEGF, and SDF-1α while GAPDH was used as the housekeeping gene (Fig 3G). The similar results were also shown with beta actin as the other housekeeping gene (S5 Fig).


Direct Renin Inhibition with Aliskiren Improves Ischemia-Induced Neovasculogenesis in Diabetic Animals via the SDF-1 Related Mechanism.

Chang TT, Wu TC, Huang PH, Lin CP, Chen JS, Lin LY, Lin SJ, Chen JW - PLoS ONE (2015)

Differential effects of aliskiren and hydralazine on protein and mRNA expressions in index thigh muscles in diabetic mice with hindlimb ischemia.Western blots of HIF-1, VEGF, SDF-1α, and actin (n = 6; A). The individual expression of HIF-1, VEGF and SDF-1α was increased in aliskiren (5 or 25 mg/kg/day) treated group (n = 6; B, C, D). (P)RR expressions were also enhanced in aliskiren-treated groups (n = 6; E). However, the expression of p-eNOS was not changed by aliskiren (n = 6; F). Quantitative RT-PCR for the effects of aliskiren on mRNA expressions in thigh muscles in diabetic mice with hindlimb ischemia (n = 6; G). N represents thigh muscles from n different individuals, and thigh muscles from each individual were experimented for 3 independent experiments. C represents untreated diabetic mice (vehicle (PBS)-treated mice); AL represents aliskiren in low dose (5 mg/kg/day); AH represents aliskiren in high dose (25 mg/kg/day); HL represents hydralazine in low dose (2 mg/kg/day); HH represents hydralazine in high dose (10 mg/kg/day). Statistical analysis was done by unpaired Student’s t test or analysis of variance, followed by Scheffe’s multiple-comparison post hoc test. A p value of <0.05 was considered statistically significant. *p < 0.05, **p < 0.01 compared with untreated diabetic mice (vehicle (PBS)-treated mice).
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4549314&req=5

pone.0136627.g003: Differential effects of aliskiren and hydralazine on protein and mRNA expressions in index thigh muscles in diabetic mice with hindlimb ischemia.Western blots of HIF-1, VEGF, SDF-1α, and actin (n = 6; A). The individual expression of HIF-1, VEGF and SDF-1α was increased in aliskiren (5 or 25 mg/kg/day) treated group (n = 6; B, C, D). (P)RR expressions were also enhanced in aliskiren-treated groups (n = 6; E). However, the expression of p-eNOS was not changed by aliskiren (n = 6; F). Quantitative RT-PCR for the effects of aliskiren on mRNA expressions in thigh muscles in diabetic mice with hindlimb ischemia (n = 6; G). N represents thigh muscles from n different individuals, and thigh muscles from each individual were experimented for 3 independent experiments. C represents untreated diabetic mice (vehicle (PBS)-treated mice); AL represents aliskiren in low dose (5 mg/kg/day); AH represents aliskiren in high dose (25 mg/kg/day); HL represents hydralazine in low dose (2 mg/kg/day); HH represents hydralazine in high dose (10 mg/kg/day). Statistical analysis was done by unpaired Student’s t test or analysis of variance, followed by Scheffe’s multiple-comparison post hoc test. A p value of <0.05 was considered statistically significant. *p < 0.05, **p < 0.01 compared with untreated diabetic mice (vehicle (PBS)-treated mice).
Mentions: Compared with PBS treatment, aliskiren (5 or 25 mg/kg/day) but not hydralazine (2 or 10 mg/kg/day) dose-dependently increased the expression of HIF-1α (Fig 3B) VEGF (Fig 3C), or SDF-1α (Fig 3D). The co-immunoprecipitation analysis also showed that SDF-1 did complex with CXCR4 (S2 Fig). Aliskiren also enhanced (P)RR expression in ischemic limbs compared with untreated diabetic mice (Fig 3E). Neither aliskiren nor hydralazine altered the expression of phosphorylated eNOS (p-eNOS) (Fig 3F). The plasma concentration of nitrite/nitrate was not changed after aliskiren or hydralazine treatments (S3 Fig). We also used L-NAME, an NO inhibitor, to teste whether NO was involved in the aliskiren related mechanism by co-treatment with aliskiren and L-NAME. The results showed that co-treatment with L-NAME do not abolish the beneficial effects of aliskiren on decreased blood pressures and on angiogenesis (S4 Fig). The effects of aliskiren on mRNA expressions in thigh muscles in diabetic mice with hindlimb ischemia were also confirmed by quantitative RT-PCR. Aiskiren dose-dependently increased the mRNA expression of HIF-1α, VEGF, and SDF-1α while GAPDH was used as the housekeeping gene (Fig 3G). The similar results were also shown with beta actin as the other housekeeping gene (S5 Fig).

Bottom Line: Given that angiogenesis is impaired in the presence of diabetes mellitus, we would like to investigate whether and how aliskiren enhances endothelial progenitor cells (EPCs) and improves ischemic-induced neovasculogenesis by an effect independent of blood pressure reduction in diabetic animals.Laser Doppler imaging and flow cytometry were used to evaluate the degree of neovasculogenesis and the circulating levels of EPCs, respectively.Intraperitoneal administration of anti-SDF-1 neutralizing monoclonal antibodies abolished the effects of aliskiren.

View Article: PubMed Central - PubMed

Affiliation: Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan, R.O.C.

ABSTRACT

Objective: Aliskiren is a direct renin inhibitor which is suggested to modify proangiogenic cells in addition to lower blood pressure. Given that angiogenesis is impaired in the presence of diabetes mellitus, we would like to investigate whether and how aliskiren enhances endothelial progenitor cells (EPCs) and improves ischemic-induced neovasculogenesis by an effect independent of blood pressure reduction in diabetic animals.

Methods: Streptozotocin-induced diabetic mice were administered with either aliskiren (5 or 25 mg/kg/day) using an osmotic pump or hydralazine (2 or 10 mg/kg/day) given in drinking water for two weeks prior to a hind-limb ischemia surgery. Laser Doppler imaging and flow cytometry were used to evaluate the degree of neovasculogenesis and the circulating levels of EPCs, respectively.

Results: In streptozotocin-induced diabetic mice, aliskiren enhanced the recovery of limb perfusion and capillary density, increased the number of circulating Sca-1+/Flk-1+ EPC-like cells, and elevated the levels of the plasma vascular endothelial growth factor (VEGF) and stromal cell-derived factor (SDF)-1α in a dose-dependent manner, whereas there were no such effects in hydralazine-treated mice. Intraperitoneal administration of anti-SDF-1 neutralizing monoclonal antibodies abolished the effects of aliskiren.

Conclusions: Independent of the reduction of blood pressure, aliskiren enhanced ischemia-induced neovasculogenesis in a dose-dependent manner via VEGF/SDF-1α related mechanisms in diabetic mice.

No MeSH data available.


Related in: MedlinePlus