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Functional Local Renin-Angiotensin System in Human and Rat Periodontal Tissue.

Santos CF, Morandini AC, Dionísio TJ, Faria FA, Lima MC, Figueiredo CM, Colombini-Ishikiriama BL, Sipert CR, Maciel RP, Akashi AP, Souza GP, Garlet GP, Rodini CO, Amaral SL, Becari C, Salgado MC, Oliveira EB, Matus I, Didier DN, Greene AS - PLoS ONE (2015)

Bottom Line: However, in inflamed tissue the immunoreactivity was greater for the AT1R compared to AT2R in fibroblasts.Ang 1-7 formation was significantly greater when human gingiva homogenates were incubated with chymostatin alone compared to incubation without any inhibitor, only captopril, or captopril and chymostatin.Furthermore, blocking AT1R and renin can significantly prevent periodontal bone loss induced by EP in rats.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil.

ABSTRACT
The initiation or progression of periodontitis might involve a local renin-angiotensin system (RAS) in periodontal tissue. The aim of this study was to further characterize the local RAS in human and rat periodontal tissues between healthy and periodontally-affected tissue. Components of the RAS were investigated using in vitro, ex vivo and in vivo experiments involving both human and Wistar rat periodontium. Although not upregulated when challenged with P. gingivalis-lipopolysaccharide, human gingival and periodontal ligament fibroblasts expressed RAS components. Likewise, healthy and inflamed human gingiva expressed RAS components, some of which were shown to be functional, yet no differences in expression were found between healthy and diseased gingiva. However, in inflamed tissue the immunoreactivity was greater for the AT1R compared to AT2R in fibroblasts. When compared to healthy tissue, ACE activity was increased in human gingiva from volunteers with gingivitis. Human-gingiva homogenates generated Ang II, Ang 1-9 and Ang 1-7 when incubated with precursors. In gingiva homogenates, Ang II formation from Ang I was nearly abolished only when captopril and chymostatin were combined. Ang 1-7 formation was significantly greater when human gingiva homogenates were incubated with chymostatin alone compared to incubation without any inhibitor, only captopril, or captopril and chymostatin. In rat gingiva, RAS components were also found; their expression was not different between healthy and experimentally induced periodontitis (EP) groups. However, renin inhibition (aliskiren) and an AT1R antagonist (losartan) significantly blocked EP-alveolar-bone loss in rats. Collectively, these data are consistent with the hypothesis that a local RAS system is not only present but is also functional in both human and rat periodontal tissue. Furthermore, blocking AT1R and renin can significantly prevent periodontal bone loss induced by EP in rats.

No MeSH data available.


Related in: MedlinePlus

Renin-Angiotensin System Components in the Gingiva Tissue of Rats with Experimentally Induced Periodontitis.A) Results of qPCR analysis for mRNA of various RAS components extracted from the rat gingiva of either sham surgery (sham) or experimentally induced periodontitis (EP) for 14 days; tested RAS components included the following: angiotensinogen (AGT), angiotensin converting enzyme (ACE), angiotensin converting enzyme 2 (ACE-2), angiotensin II receptor type 1A (AT1AR), angiotensin II receptor type 1B (AT1BR), angiotensin II receptor type 2 (AT2R), and Mas receptor (MasR). Graph displays expression levels of the target mRNA relative to β-actin mRNA from 5 rats in duplicate (n = 5). Solid bars represent the means with SD of sham group; whereas, open bars represent animals with EP. A one-way ANOVA and Tukey’s test with statistical significance set at p-value < 0.05 was used. B) All images are at 10x magnification and scale bars indicate a distance of 100 μm. Immunoreactivity (IR) for renin (panels a to d), ACE (panels e to h), AT1R (panels i to l) or AT2R (panels m to p) in rat gingiva and bone tissue. Brown staining indicates positive IR. Black arrows indicate some of the positive IR in the positive controls. Negative (panel a) and positive (panel b) control for renin in rat kidney. Panel c) negative control for renin in mandible of rat with 14 d of EP treated with water. Panel d) immunoreactivity for renin in mandible of rat with 14 d of EP treated with water. Negative (panel e) and positive (panel f) control for ACE in a rat kidney. Panel g) negative control for ACE in mandible of rat with 14 d of EP treated with water. Panel h) immunoreactivity for ACE in mandible of rat with 14 d of EP treated with water. Negative (panel i) and positive (panel j) control for AT1Rs in a rat adrenal gland. Panel k) negative control for AT1Rs in mandible of rat with 14 d of EP treated with water. Panel l) Immunoreactivity for AT1Rs in mandible of rat with 14 d of EP treated with water. Negative (panel m) and positive (panel n) control for AT2Rs in a rat adrenal gland. Panel o) negative control for AT2Rs in mandible of rat with 14 d of EP treated with water. Panel p) immunoreactivity for AT2Rs in mandible of rat with 14 d of EP treated with water. C) Table indicating location of immunoreactivity observed in 2 sections of 5 rats with 14 d of EP treated with water for renin, ACE, AT1Rs and AT2Rs in different mandibular regions: (-) indicates negative immunoreactivity, (+) indicates positive immunoreactivity and (++) indicates abundant immunoreactivity.
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pone.0134601.g005: Renin-Angiotensin System Components in the Gingiva Tissue of Rats with Experimentally Induced Periodontitis.A) Results of qPCR analysis for mRNA of various RAS components extracted from the rat gingiva of either sham surgery (sham) or experimentally induced periodontitis (EP) for 14 days; tested RAS components included the following: angiotensinogen (AGT), angiotensin converting enzyme (ACE), angiotensin converting enzyme 2 (ACE-2), angiotensin II receptor type 1A (AT1AR), angiotensin II receptor type 1B (AT1BR), angiotensin II receptor type 2 (AT2R), and Mas receptor (MasR). Graph displays expression levels of the target mRNA relative to β-actin mRNA from 5 rats in duplicate (n = 5). Solid bars represent the means with SD of sham group; whereas, open bars represent animals with EP. A one-way ANOVA and Tukey’s test with statistical significance set at p-value < 0.05 was used. B) All images are at 10x magnification and scale bars indicate a distance of 100 μm. Immunoreactivity (IR) for renin (panels a to d), ACE (panels e to h), AT1R (panels i to l) or AT2R (panels m to p) in rat gingiva and bone tissue. Brown staining indicates positive IR. Black arrows indicate some of the positive IR in the positive controls. Negative (panel a) and positive (panel b) control for renin in rat kidney. Panel c) negative control for renin in mandible of rat with 14 d of EP treated with water. Panel d) immunoreactivity for renin in mandible of rat with 14 d of EP treated with water. Negative (panel e) and positive (panel f) control for ACE in a rat kidney. Panel g) negative control for ACE in mandible of rat with 14 d of EP treated with water. Panel h) immunoreactivity for ACE in mandible of rat with 14 d of EP treated with water. Negative (panel i) and positive (panel j) control for AT1Rs in a rat adrenal gland. Panel k) negative control for AT1Rs in mandible of rat with 14 d of EP treated with water. Panel l) Immunoreactivity for AT1Rs in mandible of rat with 14 d of EP treated with water. Negative (panel m) and positive (panel n) control for AT2Rs in a rat adrenal gland. Panel o) negative control for AT2Rs in mandible of rat with 14 d of EP treated with water. Panel p) immunoreactivity for AT2Rs in mandible of rat with 14 d of EP treated with water. C) Table indicating location of immunoreactivity observed in 2 sections of 5 rats with 14 d of EP treated with water for renin, ACE, AT1Rs and AT2Rs in different mandibular regions: (-) indicates negative immunoreactivity, (+) indicates positive immunoreactivity and (++) indicates abundant immunoreactivity.

Mentions: An animal model was used with pharmacological manipulation of the RAS. Analysis using qPCR indicated that mRNA expression levels of the RAS components tested (AGT, ACE, ACE-2, AT1AR, AT1BR, AT2R and the MasR) were present but not significantly different between rats with and without EP after 14d (Fig 5A). Additionally, renin mRNA expression levels were undetectable by qPCR in either group of rats. Ancillary experiments indicated that enalapril (10 mg/Kg) and losartan (50 mg/Kg) doses used were physiologically effective, since blood pressure remained steady after injections of Ang I or Ang II (S1B and S1C Fig, respectively). Additionally, the dose used for aliskiren (30 mg/Kg) was shown to be physiologically effective since these treated rats had decreased basal arterial blood pressure when compared to rats not treated with aliskiren (S1 Fig).


Functional Local Renin-Angiotensin System in Human and Rat Periodontal Tissue.

Santos CF, Morandini AC, Dionísio TJ, Faria FA, Lima MC, Figueiredo CM, Colombini-Ishikiriama BL, Sipert CR, Maciel RP, Akashi AP, Souza GP, Garlet GP, Rodini CO, Amaral SL, Becari C, Salgado MC, Oliveira EB, Matus I, Didier DN, Greene AS - PLoS ONE (2015)

Renin-Angiotensin System Components in the Gingiva Tissue of Rats with Experimentally Induced Periodontitis.A) Results of qPCR analysis for mRNA of various RAS components extracted from the rat gingiva of either sham surgery (sham) or experimentally induced periodontitis (EP) for 14 days; tested RAS components included the following: angiotensinogen (AGT), angiotensin converting enzyme (ACE), angiotensin converting enzyme 2 (ACE-2), angiotensin II receptor type 1A (AT1AR), angiotensin II receptor type 1B (AT1BR), angiotensin II receptor type 2 (AT2R), and Mas receptor (MasR). Graph displays expression levels of the target mRNA relative to β-actin mRNA from 5 rats in duplicate (n = 5). Solid bars represent the means with SD of sham group; whereas, open bars represent animals with EP. A one-way ANOVA and Tukey’s test with statistical significance set at p-value < 0.05 was used. B) All images are at 10x magnification and scale bars indicate a distance of 100 μm. Immunoreactivity (IR) for renin (panels a to d), ACE (panels e to h), AT1R (panels i to l) or AT2R (panels m to p) in rat gingiva and bone tissue. Brown staining indicates positive IR. Black arrows indicate some of the positive IR in the positive controls. Negative (panel a) and positive (panel b) control for renin in rat kidney. Panel c) negative control for renin in mandible of rat with 14 d of EP treated with water. Panel d) immunoreactivity for renin in mandible of rat with 14 d of EP treated with water. Negative (panel e) and positive (panel f) control for ACE in a rat kidney. Panel g) negative control for ACE in mandible of rat with 14 d of EP treated with water. Panel h) immunoreactivity for ACE in mandible of rat with 14 d of EP treated with water. Negative (panel i) and positive (panel j) control for AT1Rs in a rat adrenal gland. Panel k) negative control for AT1Rs in mandible of rat with 14 d of EP treated with water. Panel l) Immunoreactivity for AT1Rs in mandible of rat with 14 d of EP treated with water. Negative (panel m) and positive (panel n) control for AT2Rs in a rat adrenal gland. Panel o) negative control for AT2Rs in mandible of rat with 14 d of EP treated with water. Panel p) immunoreactivity for AT2Rs in mandible of rat with 14 d of EP treated with water. C) Table indicating location of immunoreactivity observed in 2 sections of 5 rats with 14 d of EP treated with water for renin, ACE, AT1Rs and AT2Rs in different mandibular regions: (-) indicates negative immunoreactivity, (+) indicates positive immunoreactivity and (++) indicates abundant immunoreactivity.
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Related In: Results  -  Collection

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Show All Figures
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pone.0134601.g005: Renin-Angiotensin System Components in the Gingiva Tissue of Rats with Experimentally Induced Periodontitis.A) Results of qPCR analysis for mRNA of various RAS components extracted from the rat gingiva of either sham surgery (sham) or experimentally induced periodontitis (EP) for 14 days; tested RAS components included the following: angiotensinogen (AGT), angiotensin converting enzyme (ACE), angiotensin converting enzyme 2 (ACE-2), angiotensin II receptor type 1A (AT1AR), angiotensin II receptor type 1B (AT1BR), angiotensin II receptor type 2 (AT2R), and Mas receptor (MasR). Graph displays expression levels of the target mRNA relative to β-actin mRNA from 5 rats in duplicate (n = 5). Solid bars represent the means with SD of sham group; whereas, open bars represent animals with EP. A one-way ANOVA and Tukey’s test with statistical significance set at p-value < 0.05 was used. B) All images are at 10x magnification and scale bars indicate a distance of 100 μm. Immunoreactivity (IR) for renin (panels a to d), ACE (panels e to h), AT1R (panels i to l) or AT2R (panels m to p) in rat gingiva and bone tissue. Brown staining indicates positive IR. Black arrows indicate some of the positive IR in the positive controls. Negative (panel a) and positive (panel b) control for renin in rat kidney. Panel c) negative control for renin in mandible of rat with 14 d of EP treated with water. Panel d) immunoreactivity for renin in mandible of rat with 14 d of EP treated with water. Negative (panel e) and positive (panel f) control for ACE in a rat kidney. Panel g) negative control for ACE in mandible of rat with 14 d of EP treated with water. Panel h) immunoreactivity for ACE in mandible of rat with 14 d of EP treated with water. Negative (panel i) and positive (panel j) control for AT1Rs in a rat adrenal gland. Panel k) negative control for AT1Rs in mandible of rat with 14 d of EP treated with water. Panel l) Immunoreactivity for AT1Rs in mandible of rat with 14 d of EP treated with water. Negative (panel m) and positive (panel n) control for AT2Rs in a rat adrenal gland. Panel o) negative control for AT2Rs in mandible of rat with 14 d of EP treated with water. Panel p) immunoreactivity for AT2Rs in mandible of rat with 14 d of EP treated with water. C) Table indicating location of immunoreactivity observed in 2 sections of 5 rats with 14 d of EP treated with water for renin, ACE, AT1Rs and AT2Rs in different mandibular regions: (-) indicates negative immunoreactivity, (+) indicates positive immunoreactivity and (++) indicates abundant immunoreactivity.
Mentions: An animal model was used with pharmacological manipulation of the RAS. Analysis using qPCR indicated that mRNA expression levels of the RAS components tested (AGT, ACE, ACE-2, AT1AR, AT1BR, AT2R and the MasR) were present but not significantly different between rats with and without EP after 14d (Fig 5A). Additionally, renin mRNA expression levels were undetectable by qPCR in either group of rats. Ancillary experiments indicated that enalapril (10 mg/Kg) and losartan (50 mg/Kg) doses used were physiologically effective, since blood pressure remained steady after injections of Ang I or Ang II (S1B and S1C Fig, respectively). Additionally, the dose used for aliskiren (30 mg/Kg) was shown to be physiologically effective since these treated rats had decreased basal arterial blood pressure when compared to rats not treated with aliskiren (S1 Fig).

Bottom Line: However, in inflamed tissue the immunoreactivity was greater for the AT1R compared to AT2R in fibroblasts.Ang 1-7 formation was significantly greater when human gingiva homogenates were incubated with chymostatin alone compared to incubation without any inhibitor, only captopril, or captopril and chymostatin.Furthermore, blocking AT1R and renin can significantly prevent periodontal bone loss induced by EP in rats.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil.

ABSTRACT
The initiation or progression of periodontitis might involve a local renin-angiotensin system (RAS) in periodontal tissue. The aim of this study was to further characterize the local RAS in human and rat periodontal tissues between healthy and periodontally-affected tissue. Components of the RAS were investigated using in vitro, ex vivo and in vivo experiments involving both human and Wistar rat periodontium. Although not upregulated when challenged with P. gingivalis-lipopolysaccharide, human gingival and periodontal ligament fibroblasts expressed RAS components. Likewise, healthy and inflamed human gingiva expressed RAS components, some of which were shown to be functional, yet no differences in expression were found between healthy and diseased gingiva. However, in inflamed tissue the immunoreactivity was greater for the AT1R compared to AT2R in fibroblasts. When compared to healthy tissue, ACE activity was increased in human gingiva from volunteers with gingivitis. Human-gingiva homogenates generated Ang II, Ang 1-9 and Ang 1-7 when incubated with precursors. In gingiva homogenates, Ang II formation from Ang I was nearly abolished only when captopril and chymostatin were combined. Ang 1-7 formation was significantly greater when human gingiva homogenates were incubated with chymostatin alone compared to incubation without any inhibitor, only captopril, or captopril and chymostatin. In rat gingiva, RAS components were also found; their expression was not different between healthy and experimentally induced periodontitis (EP) groups. However, renin inhibition (aliskiren) and an AT1R antagonist (losartan) significantly blocked EP-alveolar-bone loss in rats. Collectively, these data are consistent with the hypothesis that a local RAS system is not only present but is also functional in both human and rat periodontal tissue. Furthermore, blocking AT1R and renin can significantly prevent periodontal bone loss induced by EP in rats.

No MeSH data available.


Related in: MedlinePlus