scholarly journals Peroxisome Proliferator Activated Receptor-αAgonist Slows the Progression of Hypertension, Attenuates Plasma Interleukin-6 Levels and Renal Inflammatory Markers in Angiotensin II Infused Mice

PPAR Research ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Justin L. Wilson ◽  
Rong Duan ◽  
Ahmed El-Marakby ◽  
Abdulmohsin Alhashim ◽  
Dexter L. Lee

The anti-inflammatory properties of PPAR-αplays an important role in attenuating hypertension. The current study determines the anti-hypertensive and anti-inflammatory role of PPAR-αagonist during a slow-pressor dose of Ang II (400 ng/kg/min). Ten to twelve week old male PPAR-αKO mice and their WT controls were implanted with telemetry devices and infused with Ang II for 12 days. On day 12 of Ang II infusion, MAP was elevated in PPAR-αKO mice compared to WT (161±4 mmHg versus145±4 mmHg) and fenofibrate (145 mg/kg/day) reduced MAP in WT + Ang II mice (134±7 mmHg). Plasma IL-6 levels were higher in PPAR-αKO mice on day 12 of Ang II infusion (30±4versus8±2 pg/mL) and fenofibrate reduced plasma IL-6 in Ang II-treated WT mice (10±3 pg/mL). Fenofibrate increased renal expression of CYP4A, restored renal CYP2J expression, reduced the elevation in renal ICAM-1, MCP-1 and COX-2 in WT + Ang II mice. Our results demonstrate that activation of PPAR-αattenuates Ang II-induced hypertension through up-regulation of CYP4A and CYP2J and an attenuation of inflammatory markers such as plasma IL-6, renal MCP-1, renal expression of ICAM-1 and COX-2.

Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Dexter L Lee ◽  
Sheree M Johnson ◽  
Ian Stukes ◽  
Nia Williams ◽  
Ugoeze C Ananaba ◽  
...  

Decreases in circadian rhythms of cardiovascular parameters, such as day to night changes in mean arterial pressure (MAP), heart rate (HR), pulse pressure (PP), systolic (SP) and diastolic pressure (DP) are an index of cardiovascular disease. Peroxisome proliferator activated receptor - alpha (PPAR-α) has been shown to decrease inflammatory markers and hypertension a slow pressor dose of Angiotensin II (Ang II); however, the role of PPAR-α on cardiovascular parameters during the initial stages of Ang II infusion is unknown. We hypothesize that the absence of PPAR-α will cause a reduction in the day to night changes in MAP, HR, PP, SP and DP during the initial stages of a slow pressor dose of Ang II. Male (10 - 12 weeks old) PPAR-αknockout (KO) and wild-type (WT) mice were infused with Ang II (400 ng/kg/min) for three days. Radiotelemetry was used to measure the cardiovascular parameters. The baseline MAP values were: 100 + 10 mmHg (WT) and 108 + 9 mmHg for KO. The baseline HR values were: 530 + 10 bpm (WT) and 526 + 6 bpm (KO). The baseline PPs were 17 + 0.2 mmHg (WT) and 18 + 0.3 mmHg (KO). The baseline SBPs were 108 + 9 mmHg (WT) and 116 + 10 mmHg (KO). The baseline DBPs were 91 + 9 mmHg (WT) and 98 + 10 mmHg (KO). During the first three days of Ang II infusion, the change in day to night MAP was 20 ± 2 mmHg and 10 ± 2 mmHg in Ang II treated WT and KO mice, respectively. Changes in day to night HR were 25 ± 4 bpm and 46 ± 7 bpm for WT and KO mice, respectively. The day to night changes in PP were 8 ± 1 mmHg for WT and 2 ± 2 mmHg for KO mice. The day to night changes in SBPs were 20 ± 2 mmHg and 12 ± 3 mmHg for WT and KO mice, respectively. Changes in day to night DBPs were 18 ± 2 mmHg for WT and 9 ± 2 mmHg for KO mice. TBARS and Interleukin-17 were increased in heart homogenates of KO + Ang II (15 ± 2 μM) and (1.5 ± 0.3 ng/mL) vs WT + Ang II (11 ± 3 μM) and (1.0 ± 0.2 ng/mL). Nitrite/Nitrate was decreased in KO + Ang II (1.0 ± 0.1 nM) vs WT + Ang II (1.5 ± 0.5 nM). In summary, the absence of PPAR-α decreases the day to night changes in MAP, SBP, DBP and PP during the initial three days of a slow pressor dose of Ang II. In the absence of PPAR-α, increases in oxidative stress and inflammation are mechanisms that may contribute to the changes in the cardiovascular parameters and suggest the occurrence of cardiovascular diseases during a slow pressor dose of Ang II-infusion.


Author(s):  
Rana A. Alaaeddine ◽  
Perihan A. Elzahhar ◽  
Ibrahim AlZaim ◽  
Wassim Abou-Kheir ◽  
Ahmed S.F. Belal ◽  
...  

: Emerging evidence supports an intertwining framework for the involvement of different inflammatory pathways in a common pathological background for a number of disorders. Of importance are pathways involving arachidonic acid metabolism by cyclooxygenase-2 (COX-2) and 15-lipoxygenase (15-LOX). Both enzyme activities and their products are implicated in a range of pathophysiological processes encompassing metabolic impairment leading to adipose inflammation and the subsequent vascular and neurological disorders, in addition to various pro-and anti-tumorigenic effects. A further layer of complexity is encountered by the disparate, and often reciprocal, modulatory effect COX-2 and 15-LOX activities and metabolites exert on each other or on other cellular targets, the most prominent of which is peroxisome proliferator-activated receptor gamma (PPARγ). Thus, effective therapeutic intervention with such multifaceted disorders requires the simultaneous modulation of more than one target. Here, we describe the role of COX-2, 15-LOX, and PPARγ in cancer and complications of metabolic disorders, highlight the value of designing multi-target directed ligands (MTDLs) modifying their activity, and summarize the available literature regarding the rationale and feasibility of design and synthesis of these ligands together with their known biological effects. We speculate on the potential impact of MTDLs in these disorders as well as emphasize the need for structured future effort to translate these early results facilitating the adoption of these, and similar, molecules in clinical research.


2019 ◽  
Vol 51 (4) ◽  
pp. 97-108 ◽  
Author(s):  
Xiao C. Li ◽  
Xiaowen Zheng ◽  
Xu Chen ◽  
Chunling Zhao ◽  
Dongmin Zhu ◽  
...  

The sodium (Na+)/hydrogen (H+) exchanger 3 (NHE3) and sodium-potassium adenosine triphosphatase (Na+/K+-ATPase) are two of the most important Na+ transporters in the proximal tubules of the kidney. On the apical membrane side, NHE3 primarily mediates the entry of Na+ into and the exit of H+ from the proximal tubules, directly and indirectly being responsible for reabsorbing ~50% of filtered Na+ in the proximal tubules of the kidney. On the basolateral membrane side, Na+/K+-ATPase serves as a powerful engine driving Na+ out of, while pumping K+ into the proximal tubules against their concentration gradients. While the roles of NHE3 and Na+/K+-ATPase in proximal tubular Na+ transport under in vitro conditions are well recognized, their respective contributions to the basal blood pressure regulation and angiotensin II (ANG II)-induced hypertension remain poorly understood. Recently, we have been fortunate to be able to use genetically modified mouse models with global, kidney- or proximal tubule-specific deletion of NHE3 to directly determine the cause and effect relationship between NHE3, basal blood pressure homeostasis, and ANG II-induced hypertension at the whole body, kidney and/or proximal tubule levels. The purpose of this article is to review the genetic and genomic evidence for an important role of NHE3 with a focus in the regulation of basal blood pressure and ANG II-induced hypertension, as we learned from studies using global, kidney- or proximal tubule-specific NHE3 knockout mice. We hypothesize that NHE3 in the proximal tubules is necessary for maintaining basal blood pressure homeostasis and the development of ANG II-induced hypertension.


2010 ◽  
Vol 298 (2) ◽  
pp. F381-F390 ◽  
Author(s):  
Ilaria Miceli ◽  
Davina Burt ◽  
Elena Tarabra ◽  
Giovanni Camussi ◽  
Paolo Cavallo Perin ◽  
...  

Increased glomerular permeability to proteins is a characteristic feature of diabetic nephropathy (DN). The slit diaphragm is the major restriction site to protein filtration, and the loss of nephrin, a key component of the slit diaphragm, has been demonstrated in both human and experimental DN. Both systemic and glomerular hypertension are believed to be important in the pathogenesis of DN. Human immortalized podocytes were subjected to repeated stretch-relaxation cycles by mechanical deformation with the use of a stress unit (10% elongation, 60 cycles/min) in the presence or absence of candesartan (1 μM), PD-123319 (1 μM), and rosiglitazone (0.1 μM). Nephrin mRNA and protein expression were assessed using quantitative real-time PCR, immunoblotting, and immunofluorescence, and the protein expression of AT1 receptor and angiotensin II secretion were evaluated. Exposure to stretch induced a significant ∼50% decrease in both nephrin mRNA and protein expression. This effect was mediated by an angiotensin II-AT1 mechanism. Indeed, podocyte stretching induced both angiotensin II secretion and AT1 receptor overexpression, podocyte exposure to angiotensin II reduced nephrin protein expression, and both the AT-1 receptor antagonist candesartan and a specific anti-angiotensin II antibody completely abolished stretch-induced nephrin downregulation. Similar to candesartan, the peroxisome proliferator-activated receptor (PPAR)-γ agonist, rosiglitazone, also inhibited stretch-induced nephrin downregulation, suggesting interference with stretch-induced activation of the angiotensin II-AT1 receptor system. Accordingly, rosiglitazone did not alter stretch-induced angiotensin II secretion, but it prevented AT1 upregulation in response to stretch. These results suggest a role for hemodynamic stress in loss of nephrin expression and allude to a role of PPAR-γ agonists in the prevention of this loss.


2014 ◽  
Vol 307 (1) ◽  
pp. F25-F32 ◽  
Author(s):  
Fei Wang ◽  
Xiaohan Lu ◽  
Kexin Peng ◽  
Li Zhou ◽  
Chunling Li ◽  
...  

(Pro)renin receptor (PRR) is predominantly expressed in the distal nephron where it is activated by angiotensin II (ANG II), resulting in increased renin activity in the renal medulla thereby amplifying the de novo generation and action of local ANG II. The goal of the present study was to test the role of cycloxygenase-2 (COX-2) in meditating ANG II-induced PRR expression in the renal medulla in vitro and in vivo. Exposure of primary rat inner medullary collecting duct cells to ANG II induced sequential increases in COX-2 and PRR protein expression. When the cells were pretreated with a COX-2 inhibitor NS-398, ANG II-induced upregulation of PRR protein expression was almost completely abolished, in parallel with the changes in medium active renin content. The inhibitory effect of NS-398 on the PRR expression was reversed by adding exogenous PGE2. A 14-day ANG II infusion elevated renal medullary PRR expression and active and total renin content in parallel with increased urinary renin, all of which were remarkably suppressed by the COX-2 inhibitor celecoxib. In contrast, plasma and renal cortical active and total renin content were suppressed by ANG II treatment, an effect that was unaffected by COX-2 inhibition. Systolic blood pressure was elevated with ANG II infusion, which was attenuated by the COX-2 inhibition. Overall, the results obtained from in vitro and in vivo studies established a crucial role of COX-2 in mediating upregulation of renal medullary PRR expression and renin content during ANG II hypertension.


PPAR Research ◽  
2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
Raquel Grau ◽  
Manuel D. Díaz-Muñoz ◽  
Cristina Cacheiro-Llaguno ◽  
Manuel Fresno ◽  
Miguel A. Iñiguez

A growing body of evidence indicates that PPAR (peroxisome proliferator-activated receptor)αagonists might have therapeutic usefulness in antitumoral therapy by decreasing abnormal cell growth, and reducing tumoral angiogenesis. Most of the anti-inflammatory and antineoplastic properties of PPAR ligands are due to their inhibitory effects on transcription of a variety of genes involved in inflammation, cell growth and angiogenesis. Cyclooxygenase (COX)-2 and vascular endothelial growth factor (VEGF) are crucial agents in inflammatory and angiogenic processes. They also have been significantly associated to cell proliferation, tumor growth, and metastasis, promoting tumor-associated angiogenesis. Aberrant expression of VEGF and COX-2 has been observed in a variety of tumors, pointing to these proteins as important therapeutic targets in the treatment of pathological angiogenesis and tumor growth. This review summarizes the current understanding of the role of PPARαand its ligands in the regulation of COX-2 and VEGF gene expression in the context of tumor progression.


PPAR Research ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Aravind T. Reddy ◽  
Sowmya P. Lakshmi ◽  
Raju C. Reddy

Peroxisome proliferator-activated receptorγ(PPARγ) is now recognized as an important modulator of leukocyte inflammatory responses and function. Its immunoregulatory function has been studied in a variety of contexts, including bacterial infections of the lungs and central nervous system, sepsis, and conditions such as chronic granulomatous disease. Although it is generally believed that PPARγactivation is beneficial for the host during bacterial infections via its anti-inflammatory and antibacterial properties, PPARγagonists have also been shown to dampen the host immune response and in some cases exacerbate infection by promoting leukocyte apoptosis and interfering with leukocyte migration and infiltration. In this review we discuss the role of PPARγand its activation during bacterial infections, with focus on the potential of PPARγagonists and perhaps antagonists as novel therapeutic modalities. We conclude that adjustment in the dosage and timing of PPARγagonist administration, based on the competence of host antimicrobial defenses and the extent of inflammatory response and tissue injury, is critical for achieving the essential balance between pro- and anti-inflammatory effects on the immune system.


Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Germán E González ◽  
Nour-Eddine Rhaleb ◽  
Xiao- P Yang ◽  
Oscar A Carretero

We previously described that chronic infusion with Angiotensin II (Ang II) increases cardiac Galectin-3 (Gal-3) expression, a carbohydrate-binding lectin present on macrophages. Also, Gal-3 was proposed to be a powerful predictor for mortality in patients with heart failure. Nevertheless, the role of Gal-3 in the pathogenesis of end organ damage (EOD) in hypertension is unknown. Here, we hypothesized that in Ang II-induced hypertension, genetic deletion of Gal-3 prevents innate immunity, EOD, and left ventricular (LV) dysfunction. Male C57 and Gal-3 KO mice were infused with vehicle (V) or Ang II (90 ng/min; s.c.) for 8 weeks and divided into: 1) C57 + V; 2) Gal-3 KO + V; 3) C57 + Ang II and 4) Gal-3 KO + Ang II. Systolic blood pressure (SBP) was measured by plestimography weekly. At 8 week, we evaluated 1) LV ejection fraction (EF) by echocardiography; 2) cardiac hypertrophy by LV weight/tibia length; 3) cardiac fibrosis by picrosirius red staining; 4) infiltrated macrophages by CD68+ staining; 5) ICAM-1 protein expression by Western blot; and 6) serum interleukin (IL)-6 by ELISA. We found that despite a similar increase in SBP and LV hypertrophy in both strains on Ang II, Gal-3 KO mice had better reserved EF and decreased inflammatory and fibrotic responses (see Table). Results: (MEAN ± SEM at 8 w) *p<0.05 C57+Ang II and Gal-3 KO+Ang II vs C57+V; ‡ p<0.05 Gal-3 KO+Ang II vs C57+Ang II. Conclusion: In Ang II-induced hypertension, deletion of Gal-3 prevents EOD and LV systolic dysfunction without altering blood pressure and LV hypertrophy. This study indicates that the deleterious effects of Ang II could be in part mediated by Gal-3, which enhanced inflammation and fibrosis.


Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1223
Author(s):  
Jung Seok Hwang ◽  
Jinwoo Hur ◽  
Won Jin Lee ◽  
Jun Pil Won ◽  
Hyuk Gyoon Lee ◽  
...  

Hypertrophy of myocytes has been implicated in cardiac dysfunctions affecting wall stress and patterns of gene expression. However, molecular targets potentially preventing cardiac hypertrophy have not been fully elucidated. In the present study, we demonstrate that upregulation of catalase by peroxisome proliferator-activated receptor δ (PPARδ) is involved in the anti-hypertrophic activity of PPARδ in angiotensin II (Ang II)-treated H9c2 cardiomyocytes. Activation of PPARδ by a specific ligand GW501516 significantly inhibited Ang II-induced hypertrophy and the generation of reactive oxygen species (ROS) in H9c2 cardiomyocytes. These effects of GW501516 were almost completely abolished in cells stably expressing small hairpin (sh)RNA targeting PPARδ, indicating that PPARδ mediates these effects. Significant concentration and time-dependent increases in catalase at both mRNA and protein levels were observed in GW501516-treated H9c2 cardiomyocytes. In addition, GW501516-activated PPARδ significantly enhanced catalase promoter activity and protein expression, even in the presence of Ang II. GW501516-activated PPARδ also inhibited the expression of atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP), which are both marker proteins for hypertrophy. The effects of GW501516 on the expression of ANP and BNP were reversed by 3-amino-1,2,4-triazole (3-AT), a catalase inhibitor. Inhibition or downregulation of catalase by 3-AT or small interfering (si)RNA, respectively, abrogated the effects of PPARδ on Ang II-induced hypertrophy and ROS generation, indicating that these effects of PPARδ are mediated through catalase induction. Furthermore, GW501516-activated PPARδ exerted catalase-dependent inhibitory effects on Ang II-induced hypertrophy by blocking p38 mitogen-activated protein kinase. Taken together, these results indicate that the anti-hypertrophic activity of PPARδ may be achieved, at least in part, by sequestering ROS through fine-tuning the expression of catalase in cardiomyocytes.


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