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1.
Mol Hum Reprod ; 27(10)2021 09 29.
Article in English | MEDLINE | ID: mdl-34463756

ABSTRACT

The epithelial to mesenchymal transition (EMT) has been implicated in the development of adenomyosis, along with dysregulated immune responses. Inflammation potentially induces Notch signaling, which could promote this EMT. The objective of this study was to investigate the involvement of immune cells and Notch1-mediated EMT in the development of adenomyosis. Adenomyosis was induced in 18 CD-1 mice by neonatal oral administration of tamoxifen (TAM group), while 18 neonates received vehicle only (Control group). Their uteri were sampled at 30, 60 or 90 days of age. Immune cell markers (Cd45, Ly6c1, Cd86, Arginine1, Cd19, Cd4, Cd8), Notch1 and its target genes (Hey1, Hey2, Hes1, Hes5) and biomarkers of EMT (E-Cadherin, Vimentin, Tgfb, Snail1, Slug, Snail3) were analyzed by quantitative RT-PCR and immunohistochemistry. Activated-Notch1 protein was measured by western blot. Aberrant expression of immune cell markers was observed in the uteri of mice as they developed adenomyosis. The expression of inflammatory cell markers, notably M1 macrophages and natural killer cells, was increased from Day 30 in the TAM group compared to controls, followed by an increase in the Cd4 marker (T cells) at Day 60. Conversely, expression of the Cd19 marker (B cells) was significantly reduced at all of the stages studied. Notch1 signaling was also highly activated compared to controls at Day 30 and Day 60. Concomitantly, the levels of several markers for EMT were also higher. Therefore, the activation of Notch1 coincides with aberrant expression of immune and EMT markers in the early development of adenomyosis.


Subject(s)
Adenomyosis/metabolism , Epithelial Cells/metabolism , Epithelial-Mesenchymal Transition , Receptor, Notch1/metabolism , Uterus/metabolism , Adenomyosis/chemically induced , Adenomyosis/immunology , Adenomyosis/pathology , Animals , Animals, Newborn , Disease Models, Animal , Epithelial Cells/immunology , Epithelial Cells/pathology , Female , Gene Expression Regulation, Developmental , Mice , Signal Transduction , Tamoxifen , Time Factors , Uterus/immunology , Uterus/pathology
2.
Sci Rep ; 9(1): 18916, 2019 12 12.
Article in English | MEDLINE | ID: mdl-31831785

ABSTRACT

Pancreatic ductal adenocarcinoma (PDAC) is supported by a complex microenvironment whose physical contribution to chemoresistance could be overcome by ultrasound (US) therapy. This study aims to investigate the ability of US-induced inertial cavitation in association with chemotherapy to alter tumor cell viability via microenvironment disruption. For this purpose, we used a 3D-coculture PDAC model partially mimicking the tumor and its microenvironment. Coculture spheroids combining DT66066 cells isolated from KPC-transgenic mice and murine embryonic fibroblasts (iMEF) were obtained by using a magnetic nanoshuttle method. Spheroids were exposed to US with incremental inertial cavitation indexes. Conditions studied included control, gemcitabine, US-cavitation and US-cavitation + gemcitabine. Spheroid viability was assessed by the reduction of resazurin and flow cytometry. The 3D-coculture spheroid model incorporated activated fibroblasts and produced type 1-collagen, thus providing a partial miniature representation of tumors with their microenvironment. Main findings were: (a) Gemcitabine (5 µM) was significantly less cytotoxic in the presence of KPC/iMEFs spheroids compared with KPC (fibroblast-free) spheroids; (b) US-induced inertial cavitation combined with Gemcitabine significantly decreased spheroid viability compared to Gemcitabine alone; (c) both cavitation and chemotherapy affected KPC cell viability but not that of fibroblasts, confirming the protective role of the latter vis-à-vis tumor cells. Gemcitabine toxicity is enhanced when cocultured spheroids of KPC and iMEF are exposed to US-cavitation. Although the model used is only a partial representation of PDAC, this experience supports the hypothesis that US-inertial cavitation can enhance drug penetration and cytotoxicity by disrupting PDAC microenvironment.


Subject(s)
Carcinoma, Pancreatic Ductal , Deoxycytidine/analogs & derivatives , Neoplasms, Experimental , Pancreatic Neoplasms , Tumor Microenvironment/drug effects , Ultrasonic Therapy , Animals , Carcinoma, Pancreatic Ductal/metabolism , Carcinoma, Pancreatic Ductal/pathology , Carcinoma, Pancreatic Ductal/therapy , Cell Line, Tumor , Deoxycytidine/pharmacology , Mice , Mice, Transgenic , Neoplasms, Experimental/metabolism , Neoplasms, Experimental/pathology , Neoplasms, Experimental/therapy , Pancreatic Neoplasms/metabolism , Pancreatic Neoplasms/pathology , Pancreatic Neoplasms/therapy , Spheroids, Cellular/metabolism , Spheroids, Cellular/pathology , Gemcitabine , Pancreatic Neoplasms
3.
Hum Reprod ; 34(7): 1225-1234, 2019 07 08.
Article in English | MEDLINE | ID: mdl-31247078

ABSTRACT

STUDY QUESTION: What are the effects of B lymphocyte inactivation or depletion on the progression of endometriosis? SUMMARY ANSWER: Skewing activated B cells toward regulatory B cells (Bregs) by Bruton's tyrosine kinase (Btk) inhibition using Ibrutinib prevents endometriosis progression in mice while B cell depletion using an anti-CD20 antibody has no effect. WHAT IS KNOWN ALREADY: A polyclonal activation of B cells and the presence of anti-endometrial autoantibodies have been described in a large proportion of women with endometriosis though their exact role in the disease mechanisms remains unclear. STUDY DESIGN, SIZE, DURATION: This study included comparison of endometriosis progression for 21 days in control mice versus animals treated with the anti-CD20 depleting antibody or with the Btk inhibitor Ibrutinib that prevents B cell activation. PARTICIPANTS/MATERIALS, SETTING, METHODS: After syngeneic endometrial transplantation, murine endometriotic lesions were compared between treated and control mice using volume, weight, ultrasonography, histology and target genes expression in lesions. Phenotyping of activated and regulatory B cells, T lymphocytes and macrophages was performed by flow cytometry on isolated spleen and peritoneal cells. Cytokines were assayed by ELISA. MAIN RESULTS AND THE ROLE OF CHANCE: Btk inhibitor Ibrutinib prevented lesion growth, reduced mRNA expression of cyclooxygenase-2, alpha smooth muscle actin and type I collagen in the lesions and skewed activated B cells toward Bregs in the spleen and peritoneal cavity of mice with endometriosis. In addition, the number of M2 macrophages decreased in the peritoneal cavity of Ibrutinib-treated mice compared to anti-CD20 and control mice. Depletion of B cells using an anti-CD20 antibody had no effect on activity and growth of endometriotic lesions and neither on the macrophages, compared to control mice. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: It is still unclear whether B cell depletion by the anti-CD20 or inactivation by Ibrutinib can prevent establishment and/or progression of endometriosis in humans. WIDER IMPLICATIONS OF THE FINDINGS: Further investigation may contribute to clarifying the role of B cell subsets in human endometriosis. STUDY FUNDING/COMPETING INTEREST(S): This research was supported by a grant of Institut National de la Santé et de la Recherche Médicale and Paris Descartes University. None of the authors has any conflict of interest to disclose.


Subject(s)
Agammaglobulinaemia Tyrosine Kinase/antagonists & inhibitors , B-Lymphocytes/drug effects , Endometriosis/drug therapy , Pyrazoles/therapeutic use , Pyrimidines/therapeutic use , Adenine/analogs & derivatives , Animals , Cytokines/blood , Disease Progression , Drug Evaluation, Preclinical , Endometriosis/blood , Endometriosis/immunology , Female , Mice, Inbred BALB C , Piperidines , Pyrazoles/pharmacology , Pyrimidines/pharmacology , T-Lymphocytes/drug effects
4.
Free Radic Biol Med ; 110: 1-10, 2017 09.
Article in English | MEDLINE | ID: mdl-28457937

ABSTRACT

The redox-sensitive nuclear factor erythroid-derived 2-like 2 (NRF2) controls endogenous antioxidant enzymes' transcription and protects against oxidative damage which is triggered by inflammation and known to favor progression of endometriosis. Glutamate Cysteine Ligase (GCL), a target gene of NRF2, is the first enzyme in the synthesis cascade of glutathione, an important endogenous antioxidant. Sixty-one patients, with thorough surgical examination of the abdominopelvic cavity, were recruited for the study: 31 with histologically-proven endometriosis and 30 disease-free women taken as controls. Expressions of NRF2 and GCL were investigated by quantitative RT-PCR and immunohistochemistry in eutopic and ectopic endometria from endometriosis-affected women and in endometrium of disease-free women. Ex vivo stromal and epithelial cells were extracted and purified from endometrial and endometriotic biopsies to explore expression of NRF2 and GCL in both stromal and epithelial compartments by western blot. Finally, in order to strengthen the role of NRF2 in endometriosis pathogenesis, we evaluated the drop of NRF2 expression in a mouse model of endometriosis using NRF2 knockout (NRF2-/-) mice. The mRNA levels of NRF2 and GCL were significantly lower in ectopic endometria of endometriosis-affected women compared to eutopic endometria of disease-free women. The immunohistochemical analysis confirmed the decreased expression of both NRF2 and GCL in ectopic endometriotic tissues compared to eutopic endometria of endometriosis-affected and disease-free women. Immunoblotting revealed a significant decreased of NRF2 and GCL expression in epithelial and stroma cells from ectopic lesions of endometriosis-affected women compared to eutopic endometria from controls. Using a murine model of endometriosis, NRF2-/- implants were more fibrotic compared to wild-type with an increased weight and volume. These findings indicate that expression of the transcription factor NRF2 and its effector GCL are both profoundly deregulated in endometriotic lesions towards increased growth and fibrogenetic processes.


Subject(s)
Choristoma/genetics , Endometriosis/genetics , Endometrium/metabolism , Glutamate-Cysteine Ligase/genetics , NF-E2-Related Factor 2/genetics , Adult , Animals , Case-Control Studies , Choristoma/metabolism , Choristoma/pathology , Disease Models, Animal , Endometriosis/metabolism , Endometriosis/pathology , Endometrium/pathology , Epithelial Cells/metabolism , Epithelial Cells/pathology , Female , Fibrosis , Gene Expression Regulation , Glutamate-Cysteine Ligase/metabolism , Humans , Mice , Mice, Inbred C57BL , Mice, Knockout , NF-E2-Related Factor 2/deficiency , NF-E2-Related Factor 2/metabolism , Oxidative Stress , Primary Cell Culture , Prospective Studies , Stromal Cells/metabolism , Stromal Cells/pathology , Tertiary Care Centers
5.
Dis Esophagus ; 29(6): 520-7, 2016 Aug.
Article in English | MEDLINE | ID: mdl-26043904

ABSTRACT

The development of techniques for endoscopic resection has provided new strategies for radical conservative treatment of superficial esophageal neoplasms, even those that are circumferential, such as Barrett's neoplasia. However, it is necessary to prevent the formation of scar tissue that can be responsible for esophageal strictures following circumferential resection. Preliminary data have suggested the possible efficacy of a hemostatic powder in the promotion of wound healing. The study aims to assess the effectiveness of Hemospray (Cook Medical) in a swine model of post-endoscopic esophageal stricture. Our prospective controlled study included 21 pigs. A 6-cm circumferential submucosal dissection of the esophagus (CESD) was performed in each pig. Group 1 (n = 11) only underwent CESD and Group 2 (n = 10) had repeated Hemospray applications after CESD. Clinical, endoscopic, and radiological monitoring were performed, blood levels of four inflammatory or pro-fibrotic cytokines were assessed, and histological analysis was performed. Median esophageal diameter was greater in the group treated with Hemospray (2 mm [1-3] vs. 3 mm [2-4], P = 0.01), and the rate of symptomatic esophageal stricture was 100% and 60% in Groups 1 and 2, respectively (P = 0.09). The thicknesses of esophageal fibrosis and inflammatory cell infiltrate were significantly lower in Group 2 than in Group 1 (P = 0.002 and 0.0003, respectively). The length of the neoepithelium was greater in Group 2 than in Group 1 (P = 0.0004). Transforming growth factor-ß levels were significantly lower in Group 2 than in Group 1 (P = 0.01). The application of Hemospray after esophageal CESD reduces scar tissue formation and promotes reepithelialization, and therefore is a promising therapeutic approach in the prevention of post-endoscopic esophageal stricture.


Subject(s)
Endoscopic Mucosal Resection , Esophageal Mucosa/drug effects , Esophageal Stenosis/prevention & control , Esophagoscopy , Hemostatics/pharmacology , Minerals/pharmacology , Postoperative Complications/prevention & control , Re-Epithelialization/drug effects , Animals , Barrett Esophagus/surgery , Cicatrix/prevention & control , Esophageal Mucosa/surgery , Esophagus/drug effects , Esophagus/surgery , Prospective Studies , Swine
6.
J Reprod Immunol ; 103: 45-52, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24534089

ABSTRACT

Immunological and angiogenetic factors enhance the implantation of endometrial cells in the peritoneal cavity. The aim of this work was to determine the role of the CXCL12-CXCR4 axis in the attraction and the peritoneal implantation of endometriotic stromal cells in deep infiltrating endometriosis (DIE). Biopsies of DIE nodules were obtained from 14 patients undergoing surgical treatment for DIE with low rectal involvement and from 12 patients without macroscopic endometriosis undergoing laparoscopy. CXCR4 expression was evaluated by Western blot analysis and flow cytometry in eutopic endometrial cells and DIE stromal cells in primary cultures derived from the biopsies. CXCL12-induced migration of DIE eutopic endometrial stromal cells was evaluated by transwell migration. CXCL12 was assayed in peritoneal fluids by ELISA. CXCR4 expression was higher in eutopic endometrial stromal cells than in control endometrial cells (p<0.05) and in DIE stromal cells (p<0.05). Eutopic endometrial stromal cells were more attracted by CXCL12 than control cells (p<0.01). CXCL12 was higher in DIE peritoneal fluids than in controls (p<0.05). CXCR4 was down-regulated in deep infiltrating endometriotic stromal cells. The CXCL12-CXCR4 axis plays a role in the attraction of eutopic endometrial cells into the peritoneal cavity, and the down-regulation of CXCR4 in resident endometriotic cells could cause their arrest in situ.


Subject(s)
Chemokine CXCL12/immunology , Endometriosis/pathology , Endometrium/cytology , Receptors, CXCR4/immunology , Ascitic Fluid/cytology , Cell Movement , Cells, Cultured , Chemokine CXCL12/biosynthesis , Endometriosis/immunology , Endometrium/physiology , Female , Humans , Inflammation/immunology , RNA, Messenger/biosynthesis , Receptors, CXCR4/biosynthesis , Receptors, CXCR4/genetics , Signal Transduction/genetics
7.
Cell Death Dis ; 2: e191, 2011 Aug 11.
Article in English | MEDLINE | ID: mdl-21833029

ABSTRACT

Organotellurides are newly described redox-catalyst molecules with original pro-oxidative properties. We have investigated the in vitro and in vivo antitumoral effects of the organotelluride catalyst LAB027 in a mouse model of colon cancer and determined its profile of toxicity in vivo. LAB027 induced an overproduction of H(2)O(2) by both human HT29 and murine CT26 colon cancer cell lines in vitro. This oxidative stress was associated with a decrease in proliferation and survival rates of the two cell lines. LAB027 triggered a caspase-independent, ROS-mediated cell death by necrosis associated with mitochondrial damages and autophagy. LAB027 also synergized with the cytotoxic drug oxaliplatin to augment its cytostatic and cytotoxic effects on colon cancer cell lines but not on normal fibroblasts. The opposite effects of LAB027 on tumor and on non-transformed cells were linked to differences in the modulation of reduced glutathione metabolism between the two types of cells. In mice grafted with CT26 tumor cells, LAB027 alone decreased tumor growth compared with untreated mice, and synergized with oxaliplatin to further decrease tumor development compared with mice treated with oxaliplatin alone. LAB027 an organotelluride catalyst compound synergized with oxaliplatin to prevent both in vitro and in vivo colon cancer cell proliferation while decreasing the in vivo toxicity of oxaliplatin. No in vivo adverse effect of LAB027 was observed in this model.


Subject(s)
Antineoplastic Agents/therapeutic use , Colonic Neoplasms/drug therapy , Naphthoquinones/therapeutic use , Organometallic Compounds/therapeutic use , Animals , Antineoplastic Agents/toxicity , Apoptosis , Caspases/metabolism , Catalysis , Cell Line, Tumor , Cell Proliferation/drug effects , Colonic Neoplasms/metabolism , Disease Models, Animal , Glutathione/metabolism , Humans , Hydrogen Peroxide/metabolism , Mice , Naphthoquinones/toxicity , Organometallic Compounds/toxicity , Organoplatinum Compounds/toxicity , Oxaliplatin , Oxidation-Reduction , Oxidative Stress , Tellurium/chemistry , Transplantation, Heterologous
8.
Int J Cancer ; 129(4): 791-8, 2011 Aug 15.
Article in English | MEDLINE | ID: mdl-21064090

ABSTRACT

Oxidative stress plays a role in the regulation of cancer cell metastasis which involves cell invasion and adhesion that could be supported by ADAM proteins through the activities of their metalloprotease and disintegrin domains. We hypothesized that oxidative stress could act through the induction of ADAM9 protein in some cancer cells. Indeed, Western blot analysis for ADAM9 performed on A549 cells exposed to H(2) O(2) reveals a dose-dependent induction of two proteins (80 and 68 kDa) correlated with a sharp increase of the ADAM protease activity measured in supernatant while the activity measured on the cell layer was slightly affected. The 80kDa protein corresponds to the mature form of ADAM9. Immunoprecipitation analysis performed on concentrated supernatants revealed that the 68 kDa protein is a secreted form of ADAM9. When exposed to H(2) O(2) , A549 cells cocultured with confluent endothelial vascular cells resulted in a 5.5 fold (p < 0.001) increase in the number of adherent cells. Similarly, matrigel assay revealed a 3.25 fold (p < 0.01) increase in the number of invasive cells. The suppression of ADAM9 expression by specific small interfering RNA reduced oxidative stress-induced invasiveness and adhesiveness. These functions could be mediated by an interaction between ADAM9 and ß1 integrin because each of them were inhibited when the experiment is performed in presence of mAbs targeting ADAM9 ectodomain or ß1-integrin. These results emphasize the importance of oxidative stress in the regulation of cancer cell metastasis and suggest that ADAM9 and its secreted isoform can be important determinants in the ability of cancer cells to disseminate.


Subject(s)
ADAM Proteins/metabolism , Cell Membrane/metabolism , Lung Neoplasms/pathology , Membrane Proteins/metabolism , Oxidants/pharmacology , Oxidative Stress , ADAM Proteins/antagonists & inhibitors , ADAM Proteins/genetics , ADAM10 Protein , ADAM17 Protein , Amyloid Precursor Protein Secretases/genetics , Amyloid Precursor Protein Secretases/metabolism , Biocompatible Materials , Blotting, Western , Cells, Cultured , Collagen/metabolism , Drug Combinations , Endothelium, Vascular/cytology , Endothelium, Vascular/metabolism , Humans , Hydrogen Peroxide/pharmacology , Integrin beta1/genetics , Integrin beta1/metabolism , Laminin/metabolism , Lung Neoplasms/metabolism , Membrane Proteins/antagonists & inhibitors , Membrane Proteins/genetics , Metalloproteases/metabolism , Protein Isoforms , Proteoglycans/metabolism , RNA, Small Interfering/genetics
9.
Ann Rheum Dis ; 66(9): 1202-9, 2007 Sep.
Article in English | MEDLINE | ID: mdl-17363403

ABSTRACT

OBJECTIVES: To investigate the role of reactive oxygen species (ROS) in the development of the various patterns of systemic sclerosis (SSc) and the mechanisms of ROS production by endothelial cells and fibroblasts. METHODS: Production of hydrogen peroxide (H(2)O(2)), nitric oxide (NO) and cellular proliferation were determined following incubation of endothelial cells and fibroblasts with 56 SSc and 30 healthy sera. Correlations were established between those markers, the type and the severity of the clinical involvements, and the response to treatment. The factors leading to ROS production were determined. RESULTS: H(2)O(2) production by endothelial cells and fibroblasts was higher after incubation with SSc sera than with normal sera (p<0.001) and with sera from SSc patients with severe complications than sera from other patients (p<0.05). Sera from patients with lung fibrosis triggered the proliferation of fibroblasts more than other SSc sera (p<0.001), whereas sera from patients with vascular complications exerted no proliferative effect on fibroblasts, but inhibited endothelial cell growth (p<0.05) and induced NO overproduction (p<0.05). Bosentan reduced NO release by 32%, whereas N-acetylcystein potentiated 5-fluorouracil (5FU) to inhibit fibroblast proliferation by 78%. Those serum-mediated effects did not involve antibodies but advanced oxidation protein products that selectively triggered cells to produce H(2)O(2) or NO. CONCLUSIONS: SSc sera induce the production of different types of ROS that selectively activate endothelial cells or fibroblasts, leading to vascular or fibrotic complications. Assaying serum-induced ROS production allows clinical activity of the disease to be followed and appropriate treatments to be selected.


Subject(s)
Reactive Oxygen Species/metabolism , Scleroderma, Systemic/metabolism , Skin/metabolism , Adult , Aged , Autoantibodies/blood , Biomarkers/blood , Cell Line , Cell Proliferation , Cells, Cultured , Endothelial Cells/immunology , Endothelial Cells/metabolism , Endothelial Cells/pathology , Female , Fibroblasts/immunology , Fibroblasts/metabolism , Fibroblasts/pathology , Humans , Hydrogen Peroxide/blood , Immunosuppressive Agents/therapeutic use , Longitudinal Studies , Male , Middle Aged , Nitric Oxide/blood , Prognosis , Scleroderma, Systemic/drug therapy , Scleroderma, Systemic/pathology , Skin/pathology
10.
Hypertension ; 38(5): 1143-9, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11711512

ABSTRACT

Vasopressin is known to acutely stimulate sodium transport in the renal collecting duct. We investigated the long-term regulation by vasopressin of the epithelial sodium channel (ENaC) in the rat kidney. Five-day infusion of dDAVP (a V(2) receptor agonist) to Brattleboro rats lacking vasopressin induced a marked increase in beta- and gamma-subunit ENaC mRNA levels in the renal cortex (beta, 85%; gamma, 100%), with no change in alpha-ENaC mRNA. Expression of beta- and gamma-ENaC mRNAs was also enhanced in lung (beta, 49%; gamma, 33%) but not in distal colon (an organ devoid of V(2) receptors). Similar results were obtained in Sprague Dawley rats after either partial water restriction or dDAVP infusion for 5 days. Transepithelial voltage and transepithelial sodium and water net fluxes were measured in isolated perfused cortical collecting ducts of Brattleboro rats. Acute addition of 2x10(-10) mol/L dDAVP to the bath increased sodium and water fluxes in the same proportion, and to a far greater extent in dDAVP-infused than in control Brattleboro rats (change in Na(+) net flux, 337+/-30 versus 49+/-11 pmol. min(-1). mm(-1), respectively; P<0.001). These effects were abolished by amiloride. Extrarenal water losses, partly originating from the lung, were reduced by high plasma vasopressin level. This study shows that vasopressin increases sodium transport in the renal collecting duct and probably in the lung, through a differential transcriptional regulation of ENaC subunits. This effect is followed by isoosmotic water reabsorption and likely contributes to the process of water conservation. It could lead to less efficient sodium excretion, however, and thus participate in some forms of salt-sensitive hypertension.


Subject(s)
Deamino Arginine Vasopressin/pharmacology , Kidney Tubules, Collecting/metabolism , Lung/metabolism , Renal Agents/pharmacology , Sodium Channels/biosynthesis , Sodium/metabolism , Animals , Deamino Arginine Vasopressin/administration & dosage , Epithelial Sodium Channels , Ion Transport/drug effects , Male , RNA, Messenger/biosynthesis , Rats , Rats, Brattleboro , Rats, Sprague-Dawley , Renal Agents/administration & dosage , Sodium Channels/genetics , Transcriptional Activation , Up-Regulation , Water-Electrolyte Balance
11.
J Hypertens ; 18(8): 1097-105, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10954002

ABSTRACT

OBJECTIVE: To study the relationship between the sensitivity to sodium content of the diet in terms of development of hypertension and the regulation of the expression of type 1 angiotensin II receptor subtypes by such a diet. METHODS: The expression of angiotensin II receptor subtype (AT1A and AT1B) mRNAs was studied by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) in the four zones of the kidneys of Sabra rats, sensitive or resistant to DOCA salt-induced hypertension (SBH/y and SBN/y, respectively). Rats were fed a high (8%) or normal (0.4%) NaCl diet. As vasopressin is known to be elevated in SBH/y rats and to be involved in DOCA-salt hypertension, we studied an additional group of SBH/y rats, fed a high sodium diet, enriched in water. RESULTS: With the absence of DOCA, SBH/y rats did not develop hypertension. The high sodium diet induced a greater fall in the plasma renin activity in the SBH/y (-95%) than in the SBN/y (-63%). In the cortex (C) and inner stripe (IS), the high sodium diet decreased AT1A and AT1B mRNAs in SBH/y and SBN/y, with a higher magnitude for SBH/y, than for SBN/y (C, -28 versus -20%; IS, -42 versus -20%). The addition of water to the high sodium diet lessened the effect of sodium in the C and IS, although the plasma renin activity (PRA) was not altered. CONCLUSION: A high sodium diet significantly decreases both AT1A and AT1B gene expression in two specific zones of the rat kidney containing the target cells of angiotensin II (C and IS). This down-regulation is organ-specific since it was observed in the kidney and adrenals, but not in the liver. Finally, SBH/y and SBN/y rats differ in the basal level of AT1 mRNA expression in the IS, and in the ability to modulate AT1 mRNA level under sodium intake.


Subject(s)
Kidney/metabolism , RNA, Messenger/biosynthesis , Receptors, Angiotensin/biosynthesis , Sodium/pharmacology , Aldosterone/blood , Animals , Blood Pressure/drug effects , Body Weight/drug effects , Diet , Hematocrit , Kidney/drug effects , Male , Organ Size/drug effects , Rats , Receptor, Angiotensin, Type 1 , Receptor, Angiotensin, Type 2 , Renal Circulation/drug effects , Renin/blood , Sodium/blood , Urodynamics/drug effects
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