bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 84: Angiotensin II Type 1a Receptor in the Subfornical Organ is Essential for Blood Pressure Regulation and Hydromineral Effects in Mouse Models of Elevated Brain Renin-Angiotensin System Activity.
Authors: Hilzendeger Aline , Davis Deborah R , Cassell Martin D , Mark Allyn L , Grobe Justin L , Sigmund Curt D
Published: July 2021

Elevated brain renin-angiotensin system (RAS) activity is necessary to increase blood pressure in many animal models of hypertension. We tested the hypothesis that AT1A receptors (AT1AR) within the subfornical organ (SFO) are required for the phenotypes that result from an increased brain RAS. We examined the effect of SFO-targeted Cre-recombinase mediated ablation of AT1A in mice treated with DOCA-salt (deoxycorticosterone acetate, 50 mg s.c. + ad lib 0.15 M NaCl). Mice homozygous for a conditional allele of the endogenous AT1A gene (AT1ARflox) were administered an adenovirus encoding Cre-recombinase and eGFP (AdCre), or eGFP alone (AdGFP) into the lateral cerebral ventricle, then treated for 3 weeks with DOCA-salt. AdCre reduced DOCA-salt hypertension (AdGFP baseline: 108±3 mmHg; AdGFP pre-DOCA: 104±3; AdGFP post-DOCA: 136±6 vs AdCre baseline: 116±2; Adcre pre-DOCA: 109±3, Adre post-DOCA: 118±5; P≤0.01), polydipsia (AdGFP+DOCA: 20.6±2.1 mL/day; AdCre+DOCA: 11.6±1.1, P<0.05), and sodium intake (AdGFP+DOCA: 2.6±0.3 mEq/day; AdCre+DOCA: 1.8±0.2, P<0.05). AdCre reduced AT1AR mRNA in the SFO (0.4±0.3 fold of AdGFP), without significant effect in the paraventricular or arcuate nuclei, or cortex; this was paralleled by SFO-specific AT1AR genomic DNA recombination. AdCre also caused SFO-specific recombination in ROSA-TdTomato reporter mice. Complementing the DOCA-salt model, we also examined the effect of AT1AR ablation in the SFO of double-transgenic sRA mice. sRA mice exhibit life-long brain-specific angiotensin overproduction via expression of human angiotensinogen via its own promoter and neuron-specific expression of human renin via the synapsin promoter. In sRA mice bred onto the AT1A conditional genetic background, AdCre significantly attenuated the polydipsia (AdGFP: -0.2±2; AdCre: -9.7±2.6 mL/day) and sodium intake (AdGFP: +0.2±0.7; AdCre: -1.3±0.4 mEq/day). Blood pressure measures are in progress. Together, these data highlight the involvement of SFO AT1A receptors in blood pressure in DOCA-salt model and additionally in hydromineral balance in two different models of increased brain RAS activity.
Abstract 85: Pre-Hypertension is a Disease Associated with Significant Structural and Functional Cardiovascular Abnormalities. It is Time to Lower the Bar.
Authors: El Shahawy Mahfouz , Entcheva Miglena , Padalia Arjun
Published: July 2021

Purpose:
To examine whether pre-HTN is a risk factor for CV structural and functional abnormalities.

METHODS:
We screened 2233 asymptomatic subjects, age 23-80, for CVD risk using Early CVD Risk Score (ECVDRS). ECVDRS consists of 10 tests: large (C1) and small (C2) artery stiffness, BP at rest and post mild exercise (PME), Carotid Intima Media Thickness (CIMT), abdominal aorta and left ventricle ultrasound, retinal photography, microalbuminuria, ECG, and pro-BNP. Pre-HTN and normotension (NT) was defined according to the JNC VII criteria.

Results:
Among the subjects screened, 38% (855 of 2233) were NT; 70% (596 of 855) were not taking CV medication. 42% (942 of 2233) of subjects were pre-HTN; 55% (521 of 942) were not taking CV medication. The untreated, NT group was split into Group A 82% (491 of 596) with norm. BP rise PME and Group B 18% (105 of 596) with abn. BP rise PME. The untreated, pre-HTN group was split into Group C 61% (318 of 521) with norm. BP rise PME and Group D 39% (203 of 521) with abn. BP rise PME. The presence of structural abnormalities in the groups is shown on Table 1.

Conclusions:
Based on our data, pre-HTN is a prevalent disease (42%), exceeding NT (38%) in the subjects screened. Pre-HTN is associated with greater functional and structural abnormalities than the NT group. The structural abnormalities, particularly CIMT (statistically significant p value of <0.0016), may be accounted for by the greater abn. BP rise PME in the pre-HTN group (39%). Based on our data, pre-HTN justifies ECVDRS screening for appropriate risk stratification and treatment. These findings may warrant lowering the bar for the definitions of HTN and pre-HTN in future guidelines.
Abstract 93: Hypertension and Renal Injury Induced by Nitric Oxide Depletion are Ameliorated by Concomitant Depletion of Hydrogen Sulfide
Authors: Wesseling Sebastiaan , Fledderus Joost O , Dijk Johanna A , Tilburgs Chantal , Verhaar Marianne C , Joles Jaap A
Published: July 2021

Chronic nitric oxide (NO) depletion induces hypertension and renal damage. Chronic kidney disease is associated with decreased NO availability and less renal H
2
S production. We hypothesized that combined depletion of NO and H
2
S aggravates hypertension and renal injury. Male 8-wk old Sprague Dawley rats were treated with vehicle, NO synthase inhibitor L-NG-nitroarginine (LNNA; 125 mg/L in drinking water), cystathionine-γ-lyase (CSE) inhibitor propargylglycine (PAG; 37.5 mg/kg BW ip daily) or LNNA
+
PAG for 1 and 4 weeks (6 rats/group). LNNA after 4w increased systolic blood pressure (SBP; 223±10
vs
. 137±3 mmHg in controls; P<0.01), proteinuria (144±35
vs.
17±2 mg/d; P<0.01), uremia (16.6±4.2
vs
. 7.0±0.4 mmol/L; P<0.05) and tubulo-interstitial injury (P<0.01). LNNA reduced urinary NO metabolite (NOx) excretion by ∼85% after 1w and 4w. PAG alone had no effect on SBP, renal function or injury, but did reduce urinary NOx excretion. Co-treatment with PAG ameliorated LNNA-induced hypertension (182±10 mmHg; P<0.01) and prevented proteinuria (27±3 mg/d), uremia (8.3±0.4 mmol/L) and tubulo-interstitial injury, but did not further reduce urinary NOx excretion. Renal H
2
S production was almost absent in all PAG groups after 1w and 4w (P<0.01) and was reduced in LNNA-treated rats after 4w (4.6±1.4
vs
. 9.2±0.5 μmol/hr/mg; P<0.01). Renal HO-1 gene expression was strongly induced in all PAG-treated groups after 1w and 4w (4 to 19-fold; P<0.01) whereas LNNA only increased HO-1 gene expression at 4w (P<0.01). Immunohistochemistry showed that renal HO-1 protein was primarily interstitial in all PAG-treated groups at 1w and 4w. In contrast, LNNA only showed HO-1 in tubular epithelium in conjunction with protein casts. Depleting NO caused hypertension and renal damage followed by reduced renal H
2
S production and increased renal HO-1 expression. Surprisingly, concomitant inhibition of CSE ameliorated hypertension and prevented renal injury. PAG almost completely blocked renal H
2
S production and caused strong induction of renal HO-1, independently of injury, suggesting that H
2
S suppresses renal HO-1 expression. In conclusion, concomitant upregulation of HO-1 expression by inhibition of H
2
S production, prevents LNNA-induced hypertension and renal injury.
Abstract 1: Deletion of the Mapk-p38 From Vascular Smooth Muscle Cells and Cardiomyocytes Causes Hypotension and Dilated Cardiomyopathy in Angiotensin II Dependent Hypertension
Authors: Mende Susanne , Bottermann Katharina , Stamer Stefanie , Thieme Manuel , Gödecke Axel , Park Joon-Keun , Rump Lars Christian , Stegbauer Johannes
Published: July 2021

The heart and the vasculature are key targets of angiotensin (Ang) II. In this regard, Ang II acting via Ang II type 1 (AT1)-receptors induces hypertension, cardiac hypertrophy and vascular injury. Since AT1-receptor stimulation have been shown to activate the mitogen activated protein kinase (MAPK) p38 leading to hypertrophy, migration and remodelling in cardiomocytes and vascular smooth muscle cells (VSMC)s in vitro, the MAPK p38 is considered as a major contributor in Ang II mediated cardiac and vascular injury. In order to investigate its role in Ang II dependent hypertension, we generated mice lacking p38alpha only in VSMC and cardiomyocytes (p38KO) using Cre-Loxp technology with a KISM22-cre transgene on a Bl6/C57 background. The specificity of p38alpha deletion was verified by western blot analysis. While cardiac function did not differ between both groups, blood pressures (BPs) were significantly lower under baseline conditions in p38KO mice compared to controls (106.4±5.2 vs. 123.6±5.4 mmHg; p<0.05). To test whether p38KO mice were protected from hypertensive heart failure and vascular injury, we infused Ang II (1000ng/kg/min) for 2 weeks. Ang II infusion caused a significantly attenuated increase in BPs in p38KOs than in controls (117.9±9.7 vs. 148.0±18.8mmHg; p<0.001). This effect could not be explained by an attenuated vascular response to Ang II in p38KOs, as acute pressor responses to Ang II in vivo and in the isolated perfused kidney as well as changes in renal blood flow were not attenuated in p38KO compared to controls. Surprisingly, in p38KOs, chronic Ang II infusion caused exaggerated cardiac fibrosis and severe dilated cardiomyopathy which was already apparent on day two after Ang II infusion (ejection fraction: 26.6±8.5 (p38KO)
vs.
60.8±9.6% (control);
p
<0.001, diastolic volume: 116.9±8.6 vs. 60.2±7.6μl,
p
<0.001; systolic volume: 88.9±10.3 vs. 24.6±6.7μl,
p
<0.001). In summary, these results suggest a divergent role of p38 in regulating blood pressure and in the pathogenesis of heart failure as Ang II induces blood pressure independent dilated cardiomyopathy in p38KO mice. However, more studies are necessary to reveal the underlying mechanism.
Abstract 13: Central Sympathoinhibition Abrogates Skeletal Muscle Fibrosis, Oxidative Stress and Autonomic Dysregulation in a Mouse Model of Muscular Dystrophy
Authors: Sabharwal Rasna , Chapleau Mark W
Published: July 2021

Sarcoglycan mutations cause muscular dystrophy in humans. We recently demonstrated that sarcoglycan delta deficient (Sgcd-/-) mice with muscular dystrophy exhibit autonomic dysregulation
[Hypertension 2010].
We hypothesized that excessive sympathetic activity contributes to skeletal muscle pathology, decreased locomotor activity and autonomic dysregulation in young (10-12 wks) Sgcd-/- mice. The centrally-acting sympathoinhibitory drug rilmenidine (RIL) was infused into the brain of control C57BL6 and Sgcd-/- mice by osmotic pump for 7-9 wks beginning at 3 wks of age (42 ng/g/hr, ICV). Separate groups of mice were infused with saline vehicle (VEH). Blood pressure (BP), heart rate (HR) and locomotor activity were measured by telemetry. Cardiac (HR responses to propranolol) and vasomotor (BP response to ganglionic blockade) sympathetic tone were increased in VEH-treated Sgcd-/- mice, and normalized by RIL (Table). The RIL-induced sympathoinhibition in Sgcd-/- mice was accompanied by increases in baroreflex sensitivity (BRS, sequence technique), cardiovagal tone (HR response to atropine) and activity, with no change in BP (Table). RIL also decreased oxidative stress (superoxide) by 56% and fibrosis in Sgcd-/- skeletal muscle. RIL did not affect measured variables in control mice (Table). In summary, RIL-induced sympathoinhibition decreased skeletal muscle pathology, increased locomotor activity and improved autonomic regulation in young Sgcd-/- mice. The results implicate increased sympathetic activity in the pathogenesis of muscular dystrophy, and suggest that targeting the brain to inhibit sympathetic activity may provide a novel therapeutic approach.
Abstract 14: Central Nervous System Deletion of the Bbs1 Gene Causes Obesity and Hypertension in Mice
Authors: Guo Deng-Fu , Morgan Donald A , Searby Charles C , Nishmura Darryl Y , Sheffield Val C , Rahmouni Kamal
Published: July 2021

Bardet-Biedl syndrome (BBS) is a pleiotropic autosomal recessive disorder with several features including obesity and hypertension. Systemic knock-out mouse models lacking expression of Bbs2, Bbs4 and Bbs6 genes, and Bbs1
M390R
knock-in recapitulated many of the BBS phenotypes including obesity. However, the role and contribution of different tissues to the various phenotypes associated with BBS including obesity and hypertension remains unclear. To address this, we generated a new conditional knockout mouse where exon 3 of the Bbs1 gene is floxed. Cre-mediated recombination causes a frame shift resulting in a premature stop. We assessed whether deletion of the Bbs1 gene in the central nervous system (CNS) affects body weight and arterial pressure. Breeding Bbs1
flox
with nestin
Cre
mice created mice deficient in Bbs1 gene only in the CNS as indicated by the loss of Bbs1 gene expression (by RT-PCR) in the hypothalamus, hippocampus, cortex and brainstem, but not in peripheral tissues such as adipose tissue, liver, kidney and skeletal muscle. Importantly, Bbs1
flox
/nestin
Cre
mice display an obesity phenotype as indicated by the increased (P<0.05) body weight (40±1 g vs. 31±1 g in controls) and fat mass measured by MRI (23±2 g vs. 9±1 g in controls) in 25 weeks old mice. We found that the obesity phenotype in Bbs1
flox
/nestin
Cre
mice is due to both an increase (P<0.05) in food intake (4.0±0.2 g vs. 3.1±0.3 g in controls) and reduction in energy expenditure as indicated by the decreased (P<0.05) O
2
consumption (2.8±0.3 mL/100g/min vs. 3.2±0.2 mL/100g/min in controls) and heat production (8.3±0.8 kcal/kg/h vs. 9.4±0.7 kcal/kg/h in controls). These results indicate that hyperphagia and low metabolic rate explain the development of obesity in Bbs1
flox
/nestin
Cre
mice. Finally, we assessed by radiotelemetry the consequence on arterial pressure of ablating the Bbs1 gene throughout the CNS. Interestingly, CNS deletion of the Bbs1 gene recapitulates the hypertension phenotype of BBS as indicated by the elevated mean arterial pressure in Bbs1
flox
/nestin
Cre
(123±3 mmHg) relative to littermate controls (112±4 mmHg, P=0.02). These findings demonstrate that Bbs genes in the CNS are critical for energy homeostasis and arterial pressure regulation.
Abstract 151: Mineralocorticoid Receptor Antagonism Prevents Vascular Remodeling in Mesenteric Arteries of Mice with type 2 Diabetes
Authors: Silva Marcondes A , Cau Stêfany B , Manzato Carla P , Touyz Rhian M , Tostes Rita C
Published: July 2021

Diabetes induces important structural alterations in large and small arteries. Aldosterone, whose plasma levels are elevated in experimental and human diabetes may actively contribute to this process. We tested the hypothesis that mineralocorticoid receptor antagonism prevents diabetes-associated arterial structural changes. Male, 12-14 weeks old db/db mice, a model of type 2 diabetes, and their non-diabetic counterpart controls were treated with spironolactone (50mg/kg/day) or vehicle (1% ethanol) by gavage for 6 weeks. Structural and mechanical parameters were determined in mesenteric arteries with a pressurized myograph (Danish Myo Tech, Aarhus, Denmark). Spironolactone treatment did not affect blood pressure or fasting glucose levels [(mg/dL) 256.5 ± 31, db/db vs. 104 ± 2.3, control, p<0.05]. Arteries of vehicle-treated db/db mice (dbV) had a smaller internal diameter vs. spironolactone-treated db/db (dbS) and control mice (Con) [(μm) 253.9 ± 24.9 vs. 312.9 ± 10.4 dbS, 338.1 ± 32.6 Con; 120mmHg, p<0.05]. Spironolactone treatment prevented the increase of the thickness of the arterial wall [(μm) 23.2 ± 1.0 dbS vs. 30.4 ± 2.0 dbV, 19.4 ± 1.1 Con, 60 mmHg, p<0.05], of the wall:lumen ratio [0.089 ± 0.003 dbS vs. 0.136 ± 0.013 dbV, 0.069 ± 0.006 Con, 60 mmHg, p<0.05] and of the cross-sectional area [(μm2) 21302.7 ± 1791.7 dbS vs. 30189.1 ± 2314.8 dbV, 19144.4 ± 2331.2 Con, 40 mmHg, p<0.05]. The treatment with spironolactone also improved arterial distensibility in db/db mice [(% mmHg-1) 1.4 ± 0.03 dbS vs. 1.1 ± 0.1 dbV, 1.4 ± 0.02 Con, 40mmHg, p<0.05] and shifted the stress-strain curve to the right, indicating a decrease in vascular stiffness. Picrosirius red staining showed a lower collagen content in arteries from mice dbS [(arbitrary units) 4.1 ± 0.9 dbS vs. 6.9 ± 0.6 dbV, 2.8 ± 0.3 Con; p<0.05]. Preliminary data show that spironolactone treatment prevents augmented vascular c-Src and p38MAPK activation in db/db mice. Our data show that spironolactone treatment prevents inward hypertrophic remodeling in db/db mice, indicating that aldosterone importantly contributes to vascular damage associated with this disease.
Abstract 155: Group IV Cytosolic Phospholipase A
2
a Disruption Protects Against Angiotensin II-Induced Hypertension and End Organ Damage
Authors: Khan Nayaab S , Song Chi Young , Bonventre Joseph V , Malik Kafait U
Published: July 2021

Previously we have shown that Group IV cytosolic phospholipase A
2
α (cPLA
2
α) is critical for the development of angiotensin (Ang) II-induced hypertension, cardiovascular dysfunction and fibrosis. This study was conducted to determine the role of cPLA
2
α in renal dysfunction and end organ damage associated with Ang II-induced hypertension. Eight weeks old male wild type (cPLA
2
α
+/+
) and cPLA
2
α knockout (cPLA
2
α
-/-
)

mice were infused with Ang II (700 ng/kg/min) or its vehicle for 2 weeks and systolic blood pressure (SBP) was measured weekly by the tail cuff method. Ang II increased SBP (mmHg) in cPLA
2
α
+/+
mice to a greater degree than in cPLA
2
α
-/-
mice (125 ± 2 to 186 ± 7 vs. 125 ± 2 to 132 ± 2 respectively, P< 0.05). Ang II caused renal fibrosis as indicated by accumulation of α-smooth muscle actin, transforming growth factor-β-positive cells and collagen deposition in the kidneys of cPLA
2
α
+/+
but not cPLA
2
α
-/-
mice. Ang II infusion increased reactive oxygen species production in the kidney measured by 2-hydroxyethidium fluorescence (AU), in cPLA
2
α
+/+
mice (16.14 ± 0.61 vehicle vs. 24.08 ± 0.61 Ang II P < 0.05) but not in cPLA
2
α
-/-
mice (16.93 ± 0.58 vehicle vs. 17.19 ± 0.93 Ang II). Mice were placed in metabolic cages to monitor their water intake and urine output. After 13 days of Ang II infusion, 24 hr water intake was increased (4.33 ± 0.14 ml to 8.17 ± 0.27 ml P < 0.05) in cPLA
2
α
+/+
mice but not in cPLA
2
α
-/-
mice (4.87 ± 0.22 ml to 4.8 ± 0.27 ml). Twenty-four hr urine output (μl) was increased to a greater extent in cPLA
2
α
+/+
mice (423.33 ± 67.26 to 2030.94 ± 191.58 P < 0.05) vs. cPLA
2
α
-/-
mice (374.37 ± 66.89 to 787.37 ± 126.50). Urine osmolality (mOsm/kg) was decreased (3778.33 ± 240.21 to 1620 ± 129.23 P < 0.05) in cPLA
2
α
+/+
but not in cPLA
2
α
-/-
mice (4042 ± 306.07 to 3372.5 ± 43.27), and proteinuria (mg/24hr) increased to a greater extent in cPLA
2
α
+/+
mice (2.07 ± 0.11 to 6.99 ± 0.34 P < 0.05) vs. cPLA
2
α
-/-
mice (1.95 ± 0.07 to 3.03 ± 0.20 in cPLA
2
α
-/-
). These data suggest that cPLA
2
α contributes to Ang II-induced hypertension, associated renal dysfunction and end organ damage, most likely due to release of arachidonic acid, activation of NADPH oxidase and generation of ROS. Thus, cPLA
2
α could serve as a potential therapeutic target in the treatment of hypertension and end organ damage.
Abstract 163: Prorenin-induced Pro-inflammatory Effect In Hypothalamic Astrocytes From Spontaneously Hypertensive Rats
Authors: Rodríguez Vermalí , de Kloet Annette , Llerena Valerie , Kitchen-Pareja Maria C , Sumners Colin
Published: July 2021

Over-activation of the renin-angiotensin system (RAS) at the paraventricular nucleus of the hypothalamus (PVN) enhances the central immune response contributing to the development and maintenance of neurogenic hypertension. Astrocytes contribute to the production and secretion of pro-inflammatory cytokines (PICs) and are a vital component of the innate immune response in the brain. The contribution of astrocyte activation during hypertension has not been investigated and the actions of prorenin (PRO) on this cell type are undefined. Astrocytes cultured from the hypothalamus of normotensive rats (Sprague Dawley; SD) or spontaneously hypertensive rats (SHR; a model of neurogenic hypertension), contain (pro)renin receptor mRNA. When compared with non-treated cells (SD: 1.0 ± 0.04; SHR: 1.0 ± 0.05), treatment of SD cultures with PRO (60 nM; 3 h) increased the mRNA levels (normalized to GAPDH) of the PICs interleukin-6 (IL-6; 2.5 ± 0.3), interleukin-1β (IL-1β; 46.7 ± 12.1) and tumor necrosis factor-α (TNF-α; 13.8 ± 2.9) (n=6; p<0.05). In SHR cells, the PIC levels after PRO treatment were 5.0 ± 0.9 (IL-6), 133.6 ± 34.9 (IL-1β) and 59.9 ± 30.8 (TNF-α) (n=5). PIC production by PRO was significantly (p < 0.05) enhanced in SHR cultures. Treatment of astrocytes with angiotensin II (Ang II; 100 nM) or angiotensin III (Ang III; 100 nM & 1 μM) failed to increase PIC mRNA levels. PRO treatment also increased the levels of lipocalin-2 (LCN-2; p < 0.05), an early marker of astrogliosis, in astrocytes from both strains and this effect was enhanced in SHR cells (3.1 ± 0.6 vs. 6.7 ± 2.4). Evidence of astrogliosis (p < 0.05) was apparent in the PVN of adult SHR brain at different stages of hypertension development (9, 12 and 16 weeks of age; 10.6 ± 0.5, 9.9 ± 0.7 and 8.9 ± 0.7 [astroglial fractional area in PVN; AfaPVN], n=4 per age group), based on glial fibrillary acidic protein (GFAP) immunostaining and quantification using Image J. Age-matched SD or Wistar Kyoto rats exhibited lower GFAP-positive staining in the PVN (6.2 ± 0.6; 4.7 ± 1.3; 5.2 ± 1.2, AfaPVN, n=4 per age group). Our findings indicate that PRO, not Ang II or III, activates hypothalamic astrocytes inducing a pro-inflammatory response, possibly contributing to the astrogliosis observed in the PVN of adult SHR.
Abstract 170: Role of Central GSK-3ß in Mediating Exercise-induced Improvement in Inflammatory Cytokines and Reduction in Blood Pressure in Hypertensive Rats
Authors: Agarwal Deepmala , Dange Rahul B , Francis Joseph
Published: July 2021

Although exercise has been recommended for the treatment of hypertension (HTN), the precise mechanisms of effects of exercise training (ExT) in HTN remain largely unexplored. Based on our recent unpublished results, here we tested the hypothesis that central increase in GSK-3β activity would cause reversal of effects of ExT in HTN. To increase GSK-3β activity in the brain, we chronically injected Triciribine (TCN) by intracerebroventricular (ICV) route. 90 Sprague-Dawley rats were randomized into six groups (n=15/group): 1) Sal+Ex+Veh; 2) Sal+Ex+TCN; 3) AngII+Sed+Veh; 4) AngII+Sed+TCN; 5) AngII+Ex+Veh; 6) AngII+Ex+TCN (Sal, saline; Ex, exercise; Veh, vehicle; Sed, sedentary). Rats were given AngII (hypertensive) or Veh (Normotensive) via osmotic minipumps. Groups 1, 2, 5, and 6 received moderate-intensity ExT for 42 days; groups 3 and 4 were sedentary. MAP was measured by radio-telemetry and cardiac function by echocardiography. The PVN tissues were examined for TNF, IL-1β, IL-10, and oxidative stress markers (iNOS, NOX2) levels. ExT delayed the progression of HTN, and improved cardiac hypertrophy and function in hypertensive rats. Chronic ICV infusion of TCN prevented these beneficial changes (Table). TCN prevented exercise-induced improvement in balance between pro- and anti-inflamamtory cytokines as well as exercise-induced reduction in oxidative stress within the PVN of hypertensive rats. These findings provide direct evidence that the beneficial effects of regular moderate-intensity ExT in HTN are mediated, at least in part, by reduced activation of central GSK-3β and potentially via improvement in inflammatory cytokines and oxidative stress within the PVN.
Abstract 171: Glycogen Synthase Kinase-3 beta Inhibition in the PVN Attenuate Hypertensive Response: Role of inflammation
Authors: Agarwal Deepmala , Cardinale Jeffrey , Sriramula Srinivas , Dange Rahul , R. Nair Anand , Francis Joseph
Published: July 2021

Emerging evidence indicate that the balance between proinflammatory cytokines (PIC) and anti-inflammatory cytokines (AIC) is an important determinant in the outcomes of cardiovascular disease. Recent evidence suggests that GSK3β has unique immunomodulatory properties to regulate both the PIC and AIC arms of the immune system. Therefore we hypothesized that chronic ANGII infusion causes phosphorylation of GSK3β in PVN neurons and alters the balance between PIC and AIC and contributes to increased sympathetic activity and high blood pressure. To test our hypothesis we used a GSK3 inhibitor given bilaterally into the PVN which inhibits the phosphorylation of GSK3β in the PVN. Rats were implanted with radiotelemetry probes and bilateral PVN cannulae and allowed to recover. Subsequently rats were implanted with osmotic minipumps for the continuous infusion of ANGII or its vehicle; simultaneously rats were also infused with GSK3β inhibitor at a dose of 100ng/kg/min given into the PVN or vehicle, for 28 days. ANGII infusion resulted in a significant increase in blood pressure by day 7(136±3.6) which remained elevated throughout the study (154±4.1; DAY 28 values) and this was accompanied by a significant increase in norepinephrine and PIC in the circulation and PVN. In contrast, treatment with the GSK3 inhibitor+ ANGII resulted in a significant decrease in blood pressure (123±1.8; day 28 values), plasma NE and PIC in the circulation and PVN neurons. These findings suggest there is a continuous, PVN-specific phosphorylation GSK3β after ANGII infusion and this modulates PIC and AIC in the PVN and contribute to high circulating levels of NE and blood pressure response.
Abstract 176: Role of Endoplasmic Reticulum Stress in the SFO in Fluid Balance and Metabolic Effects of Brain Renin-Angiotensin System Activation
Authors: Jo Fusakazu , Jo Hiromi , Hilzendeger Aline M , Cassell Martin D , Rutkowski D. T , Davisson Robin L , Grobe Justin L , Sigmund Curt D
Published: July 2021

Endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) have been identified as important contributors to neurological diseases and have been implicated in mediating hypothalamic inflammation and the hypertensive response to angiotensin II. We examined the role of ER stress and the UPR in the metabolic and fluid balance effects of brain angiotensin in two mouse models: 1) “sRA” transgenic mice (expressing human renin in neurons via the synapsin promoter crossed with human angiotensinogen via its own promoter), and 2) DOCA-salt treated C57BL/6J mice. Both DOCA-salt and sRA mice exhibit hyperactivity of the brain RAS, suppression of circulating RAS, hypertension, polydipsia, and an elevated resting metabolic rate. We examined the accumulation of UPR biomarker CCAAT-enhancer-binding protein homologous protein (CHOP) by immunocytochemistry in the brain of both models. CHOP is considered a marker of chronic ER stress. Increased CHOP immunoreactivity was evident in the subfornical organ (SFO) of sRA mice but was absent in non-transgenic (NT) and CHOP-/- mice. There was also increased CHOP immunoreactivity in the SFO of DOCA-salt mice compared with untreated controls. Next, we infused the ER stress-reducing chemical chaperone tauroursodeoxycholic acid (TUDCA, 5.28 ug/day, or aCSF vehicle) to assess if ER stress is mechanistically related to the hypertension, polydipsia, and elevated resting metabolic rate observed in both models. ICV TUDCA (3-5 day pretreatment then continuously for 3 wks) significantly attenuated the polydipsia (aCSF 20.7±0.9 vs TUDCA 10.8±1.0 mL/day, P<0.05) and metabolic rate (aCSF, 3.38±0.07 vs TUDCA 3.16±0.06 mL O2/100g/min, P<0.05) in the DOCA-salt model. ICV TUDCA (3 wks) had similar effects on the polydipsia in the sRA model (51±10% of aCSF control, P<0.05). DOCA-salt caused (P<0.05) increases in 24 hr mean arterial pressure (MAP) that were unaffected by ICV TUDCA (aCSF baseline 114±3 to 128±4 mmHg with DOCA-salt; TUDCA 117±7 to 129±4). Heart rate responses to DOCA-salt were attenuated (P<0.05) with ICV TUDCA (aCSF baseline 528±10 to 448±15 BPM with DOCA-salt; TUDCA 529±6 to 486±11). Together these data mechanistically implicate ER stress in the fluid and metabolic responses to increased brain RAS activity.
Abstract 188: Loss of Renal Prolyl Carboxypeptidase in Mice With Chronic Kidney Disease
Authors: Leiva Orly , Elased Khalid M , Morris Mariana , Grobe Nadja
Published: July 2021

There are 26 million adults with chronic kidney disease (CKD) in the U.S. and the incidence continues to increase. It is well documented that the activation of the renin angiotensin system and the elevated formation of angiotensin (Ang) II both contribute to renal pathophysiology in CKD. Emerging evidence suggests that the Ang II degrading protease prolyl carboxypeptidase (PCP) is renoprotective. Thus, we investigated protein expression and activity of renal PCP using immunofluorescence, western blot and mass spectrometry in a mouse model of CKD. Renal injury in male C57Bl6 mice was caused by constriction of the left renal artery using silver clips (2K1C-method). Blood pressure measurements by radiotelemetry revealed a significant increase of 36.1 ± 3.9 mm Hg in 2K1C animals compared with control animals 1 week after clip placement (p<0.0001). Using immunofluorescence and confocal microscopy, PCP was localized in the Bowman’s capsule of the glomerulus and in proximal and distal renal tubules. Western blot analysis showed PCP was significantly reduced in clipped 2K1C kidneys compared to unclipped kidneys of the 2K1C mice or compared to control mice (clipped 0.04 ± 0.02 vs unclipped 0.58 ± 0.16 vs control 0.65 ± 0.18, p < 0.05). In addition, renal PCP enzyme activity was found to be markedly reduced in 2K1C kidneys as assessed by mass spectrometric based enzyme assays (clipped 37.1 ± 4.3 pmol Ang-(1-7)/h/μg vs unclipped 77.3 ± 12.3 pmol Ang-(1-7)/h/μg vs control 120.7 ± 14.7 pmol Ang-(1-7)/h/μg, p < 0.01). In contrast, protein expression of prolyl endopeptidase, another enzyme capable of converting Ang II into Ang-(1-7), was not affected. Notably, renal pathologies were exacerbated in the 2K1C model as revealed by a significant increase in mesangial expansion (clipped 34.6 ± 3.1 vs unclipped 52.1 ± 4.0 vs control 1.2 ± 2.1, p < 0.0001) and renal fibrosis (clipped 57.5 ± 0.9 vs unclipped 33.0 ± 0.7 vs control 3.3 ± 0.2, p < 0.0001). Results suggest that PCP is suppressed in chronic kidney injury and that this downregulation may attenuate renoprotective effects via impaired Ang II degradation by PCP. Therefore, Ang II processing by PCP may have clinical implications in patients with renal pathologies.
Abstract 19: Blood Pressure Correlates Directly with the Expression Level of High Ouabain Affinity a2 Na+ Pumps in Arterial Smooth Muscle
Authors: Chen Ling , Song Hong , Kotlikoff Michael I , Lee Jane , Pritchard Tracy J , Paul Richard J , Li Meng , Blaustein Mordecai P
Published: July 2021

High ouabain affinity α2 Na
+
pumps are expressed in arterial smooth muscle (ASM). They help regulate blood pressure (BP) in several forms of hypertension, but their influence on basal BP is controversial. We determined basal BP (telemetry), and the effects of subcutaneous (sc) angiotensin II (Ang II) and dietary salt on BP in: 1) α2
SM/Tg
mice, which express an α2 transgene controlled by an α-actin smooth muscle (SM) promoter; 2) α2
SM/DN
mice, which express a truncated α2 gene, dominant negative for native α2 Na
+
pumps, controlled by the SM myosin heavy chain promoter. Expression (immunoblots) of α2 was significantly up- and down-regulated in SM from α2
SM/Tg
and α2
SM/DN
mice, respectively.

Basal 24 hr mean BP (MBP) was reduced in α2
SM/Tg
mice: 103±1 (
n
=15) vs 110±2 mm Hg (
n
=9) in WT controls;
P
<0.01. Ang II, 400 ng/kg/min sc x 2 wks, increased MBP in both WT and transgenic mice (
n
=5 each;
P
<0.01), but the increase (Δ) was smaller in α2
SM/Tg
, Δ=20.3±3.3, than in WT mice, Δ=30.9±6.4 mm Hg . Also, a high (2% x 2 wks) NaCl diet, along with a sc 300 ng/kg/min (low dose) Ang II infusion, elevated systolic BP (SBP) in the WT mice (Δ=12.6±1.8 mm Hg;
n
=4;
P
<0.05), but not in the α2
SM/Tg
mice (Δ=7.2±2.0 mm Hg;
n
=9; NS=not significant).

In contrast, in α2
SM/DN
mice, basal SBP was elevated: 128±4 mm Hg (
n
=11) vs 109±4 mm Hg (
n
=10) in WT;
P
<0.01. Furthermore, both high NaCl (HS, 6% x 10 days), and low dose sc Ang II infusion (240 ng/kg/min x 8 days), individually induced significantly greater increases in MBP in α2
SM/DN
than in WT mice. In α2
SM/DN
mice, the HS diet raised MBP by Δ=6.8±0.7 mm Hg (
n
=5;
P
<0.01); Ang II elevated MBP by Δ=17.1±3.7 mm Hg (
n
=5;
P
<0.05). In WT mice, however, HS did not elevate MBP (Δ=2.6±1.4;
n
=5; NS), and Ang II elevated MBP by only Δ=6.9±4.0 mm Hg;
n
=5;
P
<0.05).

Conclusion:
ASM α2 Na
+
pumps help regulate basal BP and vascular reactivity. Reduced α2 expression raises basal BP and augments arterial responses to salt and Ang II; increased ASM α2 expression has the opposite effects. The α2 Na
+
pumps co-localize with Na/Ca exchangers in plasma membrane (PM) microdomains at MP-sarcoplasmic reticulum junctions; they are a crucial link between circulating endogenous ouabain and the control of ASM Ca
2+
homeostasis, arterial contraction and tone.
Abstract 201: Mice Lacking the Gene for Toll-like Receptor 4 (TLR4) Had an Attenuated ER Stress in the Heart in Response to Ang II Infusion
Authors: Dange Rahul , R. Nair Anand , Vila Jorge , Ebenezer Philip J , Francis Joseph
Published: July 2021

Inflammatory molecule plays an important role in the pathophysiology of hypertension. Recently we showed that TLR4 inhibition in the brain attenuates hypertension. In this study we demonstrate that ANGII induced ER stress in the heart is attenuated in mice lacking the gene for TLR4. In addition, we show that ANGII induced cardiac hypertrophy is blocked by ER stress inhibitor.

Method:
TLR4 knock-out (KO) mice and wild type (WT) controls were implanted with telemetry probes for mean arterial pressure (MAP) measurements. After collecting baseline MAP and left ventricular function using echocardiography, osmotic minipump containing ANGII (200ng/kg/min) or vehicle (saline) was implanted for 14 days. In another group, C57BL6 mice were injected with ER stress inhibitor 4-PBA (150mg/kg bw) given intraperitoneally with and without ANGII. At the end of the study, mice were sacrificed the LV tissue removed and analyzed for gene of interest using RT-PCR and Western blotting.

Results are tabulated.
The real-time PCR values are shown as αCT values (18S - the gene of interest).

Conclusions:
1) ANGII infusion induces cardiac hypertrophy and ER stress. 2) Mice lacking the gene for TLR4 had attenuated cardiac hypertrophy and ER stress in response to ANGII. 3) ER stress inhibitor protect against ANGII induces cardiac hypertrophy. 4) TLR4 at least in part contributes to ANG II induced cardiac hypertrophy and ER stress.
Abstract 209: NAD(P)H Oxidase-Derived Superoxide Contributes to Impaired Cutaneous Microvascular Function in Chronic Kidney Disease
Authors: DuPont Jennifer J , Ramick Meghan G , Farquhar William B , Townsend Raymond R , Edwards David G
Published: July 2021

Endothelial dysfunction occurs in chronic kidney disease (CKD) and cardiovascular disease is the most common cause of death in these patients. Oxidative stress has been shown to be a mechanism of vascular dysfunction in CKD. We utilized the cutaneous circulation to test the hypothesis that superoxide derived from NAD(P)H oxidase and xanthine oxidase impair nitric oxide (NO)-dependent cutaneous vasodilation patients with CKD. Twenty subjects, 10 stage 3 and 4 CKD patients (61±4 years; 5 male/5 female; eGFR: 39 ± 4 ml·min
-1
·1.73m
-2
) and 10 healthy controls (HC) (55±2 years; 4 male/6 female; eGFR: >60 ml·min
-1
·1.73m
-2
) were instrumented with 4 intradermal microdialysis fibers in the forearm for the local delivery of 1) Ringers solution (Control), 2) 10 μM Tempol to scavenge superoxide, 3) 100 μM apocynin to inhibit NAD(P)H oxidase, and 4) 10 μM allopurinol to inhibit xanthine oxidase. Red blood cell (RBC) flux was measured via laser Doppler flowmetry during standardized local heating (42°C). After the local heating response was established, 10 mM L-NAME was infused into all four sites to quantify the NO-dependent portion of the response. Cutaneous vascular conductance (CVC) was calculated as RBC flux/mean arterial pressure and all data are presented as a percentage of maximum CVC achieved during 28mM sodium nitroprusside infusion at 43°C. The plateau in cutaneous vasodilation was attenuated in CKD at the control site (CKD: 77±3 vs. HC: 88±3 %, p<0.05). Tempol and apocynin augmented the plateau in cutaneous vasodilation in CKD patients (Tempol: 88±2, apocynin: 91±2 %, p<0.05 vs. CKD control site) but had no effect in the healthy control group. The NO-dependent portion of the response was reduced in CKD at the control site (CKD: 41±4 vs. HC: 58±2 %, p<0.05). Tempol and apocynin augmented NO-dependent portion of the response in CKD patients (Tempol: 58±3, apocynin: 58±4 %, p<0.05 vs. CKD control site) but had no effect in the healthy control group. Inhibition of xanthine oxidase did not alter the plateau in cutaneous vasodilation in either group (p>0.05). These data suggest that NAD(P)H oxidase is a source of superoxide and contributes to microvascular dysfunction in CKD.
Abstract 214: Exercise Training Attenuates ER Stress in the Kidney Cortex and Improves Renal Function in the Angiotension II-induced Hypertensive Rats
Authors: R. Nair Anand , Masson Gustavo S , Ebenezer Philip J , Francis Joseph
Published: July 2021

Exercise training (ExT) is recommended as an adjuvant to many hypertensive therapies. Recently, we demonstrated that ExT preserves renal structure and function in spontaneously hypertensive rats. However, the mechanism for these beneficial effects of exercise on renal function is not known. In this study, we examined whether ANGII induced ER stress and renal dysfunction in the kidney is attenuated by ExT.

Methods:
Rats were randomized into sedentary or exercise training (ExT) group. Hypertension was induced by implanting osmotic minipumps containing saline or ANGII 200ng/kg/min for 28 days. At the end of the study animals underwent acute renal clearance study and blood pressure measurements using direct recording. At the conclusion of the study, kidney cortex was examined for ER stress, oxidative stress and renal injury markers using RT-PCR and Western blotting.

Results:
are tabulated. Protein expression for Grp78 and CHOP were consistent with the RT-PCR data. Studies are underway to determine whether blocking ER stress by itself improves renal function in ANGII infused rats.

Conclusions:
1. ANGII induces ER stress and TLR4 in the renal cortex and impairs renal function. 2. ExT attenuates ER stress, inflammation and improves renal function in ANGII induced rats. 3. Disruption of ER function by increased oxidative stress is prevented by ExT a novel pathway for improved renal hemodynamics.
Abstract 219: Adipose Angiotensin AT
2
Receptors Inhibit Resting Metabolism
Authors: Littlejohn Nicole K , Weidemann Benjamin J , Morgan Donald A , Rahmouni Kamal , Sigmund Curt D , Grobe Justin L
Published: July 2021

The brain renin-angiotensin system (RAS) modulates blood pressure and resting metabolic rate (RMR). Double-transgenic “sRA” mice exhibit brain-specific elevations in RAS activity, as a human renin transgene is expressed via the neuron-specific synapsin promoter and a human angiotensinogen transgene is expressed via its own promoter. sRA mice have a significantly lower body weight due primarily to increased RMR, which is sustained through chronically increased sympathetic nerve activity (SNA) and a hypertension-mediated suppression of the circulating RAS. Here we identified the anatomical site of increased thermogenesis, and the components of the adipose/circulating RAS that suppress RMR in the sRA model. Expression of uncoupling protein 1 (UCP1) was elevated specifically within the inguinal fat of sRA mice, with no changes in UCP1 in interscapular or epididymal fat or skeletal muscle, and no change in UCP3 in skeletal muscle or any fat pad. UCP1 mRNA in differentiated 3T3L1 adipocytes was increased following treatment with the AT
2
R antagonist PD-123,319 and suppressed with the AT
2
R agonist CGP-42112a (CGP), but was unaffected by the AT
1
R antagonist losartan. Infusion of CGP (50 ng/kg/min, 8 wk, sc) into adult sRA mice normalized body mass (control n=5, 25.0±1.8; sRA n=5, 17.7±0.6*; sRA+CGP n=7, 22.7±2.0** g), epididymal fat (control 317±100, sRA 127±16*, sRA+CGP 247±45** mg/g), and RMR (control 2.8±0.2, sRA 3.6±0.2*, sRA+CGP 3.1±0.2** mL O
2
/100g/min). Food intake was unchanged across groups (control 10.5±0.5, sRA 9.8±0.6, sRA+CGP 11.2±0.9 kcal/d). CGP treatment did not suppress SNA to inguinal fat in sRA mice (control 9.7±1.0, sRA 14.7±1.3*, sRA+CGP 18.9±3.3* spikes/sec). sRA mice exhibit generally normal glucose tolerance but grossly increased insulin sensitivity (0.5 U/kg; control nadir 72±8, sRA nadir 27±5 mg/dL), and ongoing studies are designed to determine whether adipose insulin signaling is modulated by AT
2
R activation. (Throughout, * P<0.05 vs control, ** P<0.05 vs sRA.) We conclude that hyperactivity of the brain RAS stimulates RMR (and possibly insulin sensitivity) specifically within the subcutaneous inguinal fat pad, and identifies AT
2
R signaling as an important regulator of thermogenic activity of adipose tissue.
Abstract 22: Histone Deacetylase (HDAC) 4 Controls Neointimal Hyperplasia via Stimulating Proliferation and Migration of Vascular Smooth Muscle Cells
Authors: Usui Tatsuya , Okada Muneyoshi , Yamawaki Hideyuki
Published: July 2021

Histone deacetylases (HDACs) are transcriptional co-regulators. We have recently demonstrated that a class IIa HDAC, HDAC4 promotes reactive oxygen species (ROS)-dependent vascular smooth muscle inflammation and mediates the development of hypertension in spontaneously hypertensive rats. Pathogenesis of hypertension is in part modulated by vascular structural remodeling via proliferation and migration of vascular smooth muscle cells (SMCs). We thus examined whether HDAC4 controls SMCs proliferation and migration. In rat mesenteric arterial SMCs, small interfering RNA (siRNA) against HDAC4 inhibited platelet-derived growth factor (PDGF)-BB-induced SMCs proliferation as determined by a cell counting (51% inhibition, n=7) or bromodeoxyuridine incorporation assay (95% inhibition, n=6) and migration as determined by Boyden chamber assay (71% inhibition, n=3). Expression and activity of HDAC4 were increased by PDGF-BB (30% increase, n=5 and 170% increase, n=4, respectively). HDAC4 siRNA inhibited phosphorylation of p38 (69% inhibition, n=5) and heat shock protein (HSP) 27 (91% inhibition, n=5) and expression of cyclin D1 (58% inhibition, n=5) as measured by Western blotting. HDAC4 siRNA also inhibited PDGF-BB-induce ROS production as measured fluorometrically using 2’ 7’-dichlorofluorescein diacetate (77% inhibition, n=4) and nicotinamide adenine dinucleotide phosphate oxidase activity as measured by lucigenin assay (61% inhibition, n=4). A Ca
2+
/calmodulin (CaM)-dependent protein kinase (CaMK) II inhibitor, KN93 inhibited PDGF-BB-induced SMCs proliferation (58% inhibition, n=4) and migration (75% inhibition, n=3) as well as phosphorylation of HDAC4 (84% inhibition, n=4). In vivo, a class IIa HDACs inhibitor, MC1568 prevented neointimal hyperplasia in mice carotid ligation model (54% inhibition, n=6). MC1568 also inhibited increased activity of HDAC4 in the neointimal lesions. The present results for the first time demonstrate that HDAC4 controls PDGF-BB-induced SMCs proliferation and migration through activation of p38/HSP27 signals via ROS generation in a CaMKII-dependent manner, which may lead to the neointima hyperplasia in vivo.
Abstract 224: Obesity Paradox in Coronary Artery Disease in Patients With Acute Chest Pain
Authors: Chaikriangkrai Kongkiat , Kassi Mahwash , Khaleel bala Sayf , Chang Su Min
Published: July 2021

Introduction
Obesity has been inconsistently linked with coronary artery calcium score (CACS) as a surrogate of coronary artery disease (CAD) in asymptomatic subjects. Our aim was to examine whether there is relationship between obesity defined by BMI≥30kg/m
2
and presence and severity of CAD defined by CACS in patients with acute chest pain.

Methods
In this cross-sectional study, 1030 consecutive patients without reported history of coronary artery disease who presented with acute chest pain were included. CACS by non-contrast CT scan and BMI were collected. Patients were categorized by CACS classifications and BMI.

Results
The population with mean age of 54±13 years, 33% (338 of 1030) of patients being overweight and 46% (477 of 1030) being obese consisted of 60.6% (624 of 1030) patients with zero CACS, 21.7% (223 of 1030) with mild calcification (0<CACS<100) and 17.8% (183 of 1030) with moderate-to-severe calcification (CACS≥100). Compared to non-overweight/non-obese group, obese group had less patients with moderate-to-severe calcification (69 of 477; 14.5% VS 50 of 215; 22.6% p-value=0.016) despite more patients with hypertension (311 of 477; 65.2% VS 98 of 215; 45.6% p-value<0.001), diabetes (98 of 477; 20.5% VS 11 of 215; 5.1% p-value<0.001) and hyperlipidemia(174 of 477; 36.5% VS 57 of 215; 26.5% p-value=0.010). Obesity is INVERSELY associated with presence of CACS and moderate-to-severe calcification in multivariable logistic regression analysis (table 1).

Conclusion
Obesity defined by body mass index ≥ 30kg/m
2
is INVERSELY associated with presence and severity of coronary artery disease defined by coronary artery calcium score in patients with acute chest pain.
Abstract 23: Foxd1+ Stromal Cells, the Required Progenitors for Kidney Vascular Development
Authors: Lin Eugene E , Gomez Roberto A , Sequeira-Lopez Maria-Luisa S
Published: July 2021

The mechanisms underlying the establishment, assembly and maintenance of the renal blood vessels are poorly understood. We have previously suggested using detailed lineage tracing that renal stromal cells, characterized by their early and transient expression of the transcription factor
Foxd1
, give rise to the entirety of the mural cell layer of the renal arterial tree and mesangial cells. Mural cells as defined here exclude endothelial cells, which we identified as having a separate precursor, the renal hemangioblast. To define whether Foxd1 cells are the required essential progenitor or whether their role as such could be assumed by other cell types, we used the cre-lox system to generate mice expressing diphtheria toxin subunit A in Foxd1+ cells (
Foxd1-DTA mice
) which resulted in animals with selective ablation of Foxd1+ cells. Kidneys from
Foxd1-DTA
embryos had a significantly reduced complement of arterial mural cells, lacking smooth muscle cells, perivascular fibroblasts, renin cells and mesangial cells. Interestingly, the few vessels that remained were also abnormal: they originated underneath the kidney capsule and elongated towards the center of the kidney rather than radiating outward from the center of the kidney. In addition, ablation of Foxd1 cells resulted in significantly delayed nephrogenesis and reduction in glomerular number. In conjunction with our previous data showing a similar phenotype upon global deletion of the
Foxd1
,gene, this illustrates the central role of
Foxd1
and the cells that express it during early development. We conclude that Foxd1 stromal cells are the required progenitors for the establishment of the mural cells of the kidney arterioles and (via
Foxd1
expression) for the proper origin and orientation of the kidney vessels.