- Jackson, Kristy, Gueguen, Cindy, Lim, Kyungjoon, Eikelis, Nina, Stevenson, Emily, Charchar, Fadi, Lambert, Gavin, Burke, Sandra, Paterson, Madeleine, Marques, Francine, Head, Geoffrey
- Authors: Jackson, Kristy , Gueguen, Cindy , Lim, Kyungjoon , Eikelis, Nina , Stevenson, Emily , Charchar, Fadi , Lambert, Gavin , Burke, Sandra , Paterson, Madeleine , Marques, Francine , Head, Geoffrey
- Date: 2020
- Type: Text , Journal article
- Relation: Hypertension Research Vol. 43, no. 11 (2020), p. 1152-1164
- Full Text: false
- Reviewed:
- Description: BPH/2J mice are a genetic model of hypertension with overactivity of the sympathetic nervous system (SNS) and renin–angiotensin system (RAS). BPH/2J display higher renal renin mRNA and low levels of its negative regulator microRNA-181a (miR-181a). We hypothesise that high renal SNS activity may reduce miR-181a expression, which contributes to elevated RAS activity and hypertension in BPH/2J. Our aim was to determine whether in vivo administration of a renal-specific miR-181a mimic or whether renal denervation could increase renal miR-181a abundance to reduce renal renin mRNA, RAS activity and hypertension in BPH/2J mice. Blood pressure (BP) in BPH/2J and normotensive BPN/3J mice was measured via radiotelemetry probes. Mice were administered miR-181a mimic or a negative control (1–25 nmol, i.v., n = 6–10) with BP measured for 48 h after each dose or they underwent renal denervation or sham surgery (n = 7–9). Injection of 5–25 nmol miR-181a mimic reduced BP in BPH/2J mice after 36–48 h (−5.3 ± 1.8, −6.1 ± 1.9 mmHg, respectively, P < 0.016). Treatment resulted in lower renal renin and inflammatory marker (TLR4) mRNA levels in BPH/2J. The mimic abolished the hypotensive effect of blocking the RAS with enalaprilat (P < 0.01). No differences between mimic or vehicle were observed in BPN/3J mice except for a higher level of renal angiotensinogen in the mimic-treated mice. Renal miR-181a levels that were lower in sham BPH/2J mice were greater following renal denervation and were thus similar to those of BPN/3J. Our findings suggest that the reduced renal miR-181a may partially contribute to the elevated BP in BPH/2J mice, through an interaction between the renal sympathetic nerves and miR-181a regulation of the RAS. © 2020, The Japanese Society of Hypertension.
- Description: This work was supported by a grant from the National Health & Medical Research Council of Australia (NHMRC, Project grant 1065714) and in part by the Victorian Government’s OIS Program. Investigators were supported by NHMRC/National Heart Foundation (NHF) Postdoctoral Fellowships (NHMRC APP1091688 to KLJ, NHMRC APP1052659 and NHF PF12M6785 and 101185 to FZM) and NHMRC Research Fellowships (APP1042492 to GWL and APP1002186 to GAH).
Renal nerves contribute to hypertension in Schlager BPH/2J mice
- Gueguen, Cindy, Jackson, Kristy, Marques, Francine, Eikelis, Nina, Phillips, Sarah, Stevenson, Emily, Charchar, Fadi, Lambert, Gavin, Davern, Pamela, Head, Geoffrey
- Authors: Gueguen, Cindy , Jackson, Kristy , Marques, Francine , Eikelis, Nina , Phillips, Sarah , Stevenson, Emily , Charchar, Fadi , Lambert, Gavin , Davern, Pamela , Head, Geoffrey
- Date: 2019
- Type: Text , Journal article
- Relation: Hypertension Research Vol. 42, no. 3 (2019), p. 306-318
- Full Text:
- Reviewed:
- Description: Schlager mice (BPH/2J) are hypertensive due to a greater contribution of the sympathetic nervous system (SNS) and renin-angiotensin system (RAS). The kidneys of BPH/2J are hyper-innervated suggesting renal nerves may contribute to the hypertension. We therefore determined the effect of bilateral renal denervation (RD) on hypertension in BPH/2J. Mean arterial pressure (MAP) was measured by radiotelemetry before and for 3 weeks after RD in BPH/2J and BPN/3J. The effects of pentolinium and enalaprilat were examined to determine the contribution of the SNS and RAS, respectively. After 3 weeks, MAP was −10.9 ± 2.1 mmHg lower in RD BPH/2J compared to baseline and −2.1 ± 2.2 mmHg in sham BPH/2J (P < 0.001, n = 8–10). RD had no effect in BPN/3J (P > 0.1). The depressor response to pentolinium was greater in BPH/2J than BPN/3J, but in both cases the response in RD mice was similar to sham. Enalaprilat decreased MAP more in RD BPH/2J compared to sham (−12 vs −3 mmHg, P < 0.001) but had no effect in BPN/3J. RD reduced renal noradrenaline in both strains but more so in BPH/2J. RD reduced renin mRNA and protein, but not plasma renin in BPH/2J to levels comparable with BPN/3J mice. We conclude that renal nerves contribute to hypertension in BPH mice as RD induced a sustained fall in MAP, which was associated with a reduction of intrarenal renin expression. The lack of inhibition of the depressor effects of pentolinium and enalaprilat by RD suggests that vasoconstrictor effects of the SNS or RAS are not involved.
- Authors: Gueguen, Cindy , Jackson, Kristy , Marques, Francine , Eikelis, Nina , Phillips, Sarah , Stevenson, Emily , Charchar, Fadi , Lambert, Gavin , Davern, Pamela , Head, Geoffrey
- Date: 2019
- Type: Text , Journal article
- Relation: Hypertension Research Vol. 42, no. 3 (2019), p. 306-318
- Full Text:
- Reviewed:
- Description: Schlager mice (BPH/2J) are hypertensive due to a greater contribution of the sympathetic nervous system (SNS) and renin-angiotensin system (RAS). The kidneys of BPH/2J are hyper-innervated suggesting renal nerves may contribute to the hypertension. We therefore determined the effect of bilateral renal denervation (RD) on hypertension in BPH/2J. Mean arterial pressure (MAP) was measured by radiotelemetry before and for 3 weeks after RD in BPH/2J and BPN/3J. The effects of pentolinium and enalaprilat were examined to determine the contribution of the SNS and RAS, respectively. After 3 weeks, MAP was −10.9 ± 2.1 mmHg lower in RD BPH/2J compared to baseline and −2.1 ± 2.2 mmHg in sham BPH/2J (P < 0.001, n = 8–10). RD had no effect in BPN/3J (P > 0.1). The depressor response to pentolinium was greater in BPH/2J than BPN/3J, but in both cases the response in RD mice was similar to sham. Enalaprilat decreased MAP more in RD BPH/2J compared to sham (−12 vs −3 mmHg, P < 0.001) but had no effect in BPN/3J. RD reduced renal noradrenaline in both strains but more so in BPH/2J. RD reduced renin mRNA and protein, but not plasma renin in BPH/2J to levels comparable with BPN/3J mice. We conclude that renal nerves contribute to hypertension in BPH mice as RD induced a sustained fall in MAP, which was associated with a reduction of intrarenal renin expression. The lack of inhibition of the depressor effects of pentolinium and enalaprilat by RD suggests that vasoconstrictor effects of the SNS or RAS are not involved.
- «
- ‹
- 1
- ›
- »