Technique of minimally invasive transverse aortic constriction in mice for induction of left ventricular hypertrophy

Transverse aortic constriction (TAC) in mice is one of the most commonly used surgical techniques for experimental investigation of pressure overload-induced left ventricular hypertrophy (LVH) and its progression to heart failure. In the majority of the reported investigations, this procedure is performed with intubation and ventilation of the animal which renders it demanding and time-consuming and adds to the surgical burden to the animal. The aim of this protocol is to describe a simplified technique of minimally invasive TAC without intubation and ventilation of mice. Critical steps of the technique are emphasized in order to achieve low mortality and high efficiency in inducing LVH. Male C57BL/6 mice (10-week-old, 25-30 g, n=60) were anesthetized with a single intraperitoneal injection of a mixture of ketamine and xylazine. In a spontaneously breathing animal following a 3-4 mm upper partial sternotomy, a segment of 6/0 silk suture threaded through the eye of a ligation aid was passed under the aortic arch and tied over a blunted 27-gauge needle. Sham-operated animals underwent the same surgical preparation but without aortic constriction. The efficacy of the procedure in inducing LVH is attested by a significant increase in the heart/body weight ratio. This ratio is obtained at days 3, 7, 14 and 28 after surgery (n = 6 - 10 in each group and each time point). Using our technique, LVH is observed in TAC compared to sham animals from day 7 through day 28. Operative and late (over 28 days) mortalities are both very low at 1.7%. In conclusion, our cost-effective technique of minimally invasive TAC in mice carries very low operative and post-operative mortalities and is highly efficient in inducing LVH. It simplifies the operative procedure and reduces the strain put on the animal. It can be easily performed by following the critical steps described in this protocol

Kinase MSK1 and obliterative bronchiolitis

La bronchiolite oblitérante (BO) est la principale cause de décès à long terme après transplantation pulmonaire. La BO se manifeste par une diminution des capacités respiratoires liée à l’obstruction des petites voies aériennes par un tissu inflammatoire et fibroprolifératif. Dans cette thèse nous avons étudié l’hypothèse de l’implication de la kinase nucléaire MSK1 dans la BO. Nous avons utilisé la transplantation hétérotopique de trachée comme modèle murin de BO. La pertinence du choix de ce modèle a été confirmée par l’étude de la re-vascularisation fonctionnelle de la greffe après transplantation. Dans ce modèle nous avons montré une augmentation de l’expression et de l’activité de MSK1 pendant le développement de la BO. Le traitement des souris transplantées avec des inhibiteurs pharmacologiques de MSK1 a permis d’inhiber l’inflammation et la fibroprolifération, montrant le rôle de MSK1 dans la BO. Nous avons également mis en place un essai de criblage utilisant la technologie HTRF pour rechercher de nouveaux inhibiteurs de MSK1. Les résultats décrits dans cette thèse, montrent que la kinase MSK1 est une potentielle cible thérapeutique pour combattre la BO.Obliterative bronchiolitis (OB) is the chronic rejection after lung transplantation and is the main cause for late death post-transplantation. OB is characterized by decrease of the pulmonary function caused by obstruction of the small airways by inflammatory and fibroproliferative tissue. We studied the hypothesis of the implication of the nuclear kinase MSK1 in the OB. The relevance of the model was demonstrated by showing the rapid functional re-vascularization of the graft. In this model the allograft, shows an increased MSK1 expression and activity. We therefore treated mice with pharmacological inhibitors of the MSK1 activity and we demonstrated an inhibition of the inflammation and the fibroproliferation during OB. We next set up an enzymatic assay using the heterogeneous time-resolved fluorescence, to proceed for a screening for new MSK1 inhibitors. In summary, this study proposed MSK1 as potential therapeutic target to combat OB

Kinase MSK1 and obliterative bronchiolitis

La bronchiolite oblitérante (BO) est la principale cause de décès à long terme après transplantation pulmonaire. La BO se manifeste par une diminution des capacités respiratoires liée à l’obstruction des petites voies aériennes par un tissu inflammatoire et fibroprolifératif. Dans cette thèse nous avons étudié l’hypothèse de l’implication de la kinase nucléaire MSK1 dans la BO. Nous avons utilisé la transplantation hétérotopique de trachée comme modèle murin de BO. La pertinence du choix de ce modèle a été confirmée par l’étude de la re-vascularisation fonctionnelle de la greffe après transplantation. Dans ce modèle nous avons montré une augmentation de l’expression et de l’activité de MSK1 pendant le développement de la BO. Le traitement des souris transplantées avec des inhibiteurs pharmacologiques de MSK1 a permis d’inhiber l’inflammation et la fibroprolifération, montrant le rôle de MSK1 dans la BO. Nous avons également mis en place un essai de criblage utilisant la technologie HTRF pour rechercher de nouveaux inhibiteurs de MSK1. Les résultats décrits dans cette thèse, montrent que la kinase MSK1 est une potentielle cible thérapeutique pour combattre la BO.Obliterative bronchiolitis (OB) is the chronic rejection after lung transplantation and is the main cause for late death post-transplantation. OB is characterized by decrease of the pulmonary function caused by obstruction of the small airways by inflammatory and fibroproliferative tissue. We studied the hypothesis of the implication of the nuclear kinase MSK1 in the OB. The relevance of the model was demonstrated by showing the rapid functional re-vascularization of the graft. In this model the allograft, shows an increased MSK1 expression and activity. We therefore treated mice with pharmacological inhibitors of the MSK1 activity and we demonstrated an inhibition of the inflammation and the fibroproliferation during OB. We next set up an enzymatic assay using the heterogeneous time-resolved fluorescence, to proceed for a screening for new MSK1 inhibitors. In summary, this study proposed MSK1 as potential therapeutic target to combat OB

Kinase MSK1 et bronchiolite oblitérante

La bronchiolite oblitérante (BO) est la principale cause de décès à long terme après transplantation pulmonaire. La BO se manifeste par une diminution des capacités respiratoires liée à l obstruction des petites voies aériennes par un tissu inflammatoire et fibroprolifératif. Dans cette thèse nous avons étudié l hypothèse de l implication de la kinase nucléaire MSK1 dans la BO. Nous avons utilisé la transplantation hétérotopique de trachée comme modèle murin de BO. La pertinence du choix de ce modèle a été confirmée par l étude de la re-vascularisation fonctionnelle de la greffe après transplantation. Dans ce modèle nous avons montré une augmentation de l expression et de l activité de MSK1 pendant le développement de la BO. Le traitement des souris transplantées avec des inhibiteurs pharmacologiques de MSK1 a permis d inhiber l inflammation et la fibroprolifération, montrant le rôle de MSK1 dans la BO. Nous avons également mis en place un essai de criblage utilisant la technologie HTRF pour rechercher de nouveaux inhibiteurs de MSK1. Les résultats décrits dans cette thèse, montrent que la kinase MSK1 est une potentielle cible thérapeutique pour combattre la BO.Obliterative bronchiolitis (OB) is the chronic rejection after lung transplantation and is the main cause for late death post-transplantation. OB is characterized by decrease of the pulmonary function caused by obstruction of the small airways by inflammatory and fibroproliferative tissue. We studied the hypothesis of the implication of the nuclear kinase MSK1 in the OB. The relevance of the model was demonstrated by showing the rapid functional re-vascularization of the graft. In this model the allograft, shows an increased MSK1 expression and activity. We therefore treated mice with pharmacological inhibitors of the MSK1 activity and we demonstrated an inhibition of the inflammation and the fibroproliferation during OB. We next set up an enzymatic assay using the heterogeneous time-resolved fluorescence, to proceed for a screening for new MSK1 inhibitors. In summary, this study proposed MSK1 as potential therapeutic target to combat OB.STRASBOURG-Bib.electronique 063 (674829902) / SudocSudocFranceF

Kinetic mRNA Profiling in a Rat Model of Left-Ventricular Hypertrophy Reveals Early Expression of Chemokines and Their Receptors

Left-ventricular hypertrophy (LVH), a risk factor for heart failure and death, is characterized by cardiomyocyte hypertrophy, interstitial cell proliferation, and leukocyte infiltration. Chemokines interacting with G protein-coupled chemokine receptors may play a role in LVH development by promoting recruitment of activated leukocytes or modulating left-ventricular remodeling. Using a pressure overload-induced kinetic model of LVH in rats, we examined during 14 days the expression over time of chemokine and chemokine receptor mRNAs in left ventricles from aortic-banded vs sham-operated animals. Two phases were clearly distinguished: an inflammatory phase (D3-D5) with overexpression of inflammatory genes such as il-1ß, tnfa, nlrp3, and the rela subunit of nf-kb, and a hypertrophic phase (D7-D14) where anp overexpression was accompanied by a heart weight/body weight ratio that increased by more than 20% at D14. No cardiac dysfunction was detectable by echocardiography at the latter time point. Of the 36 chemokines and 20 chemokine receptors analyzed by a Taqman Low Density Array panel, we identified at D3 (the early inflammatory phase) overexpression of mRNAs for the monocyte chemotactic proteins CCL2 (12-fold increase), CCL7 (7-fold increase), and CCL12 (3-fold increase), for the macrophage inflammatory proteins CCL3 (4-fold increase), CCL4 (2-fold increase), and CCL9 (2-fold increase), for their receptors CCR2 (4-fold increase), CCR1 (3-fold increase), and CCR5 (3-fold increase), and for CXCL1 (8-fold increase) and CXCL16 (2-fold increase). During the hypertrophic phase mRNA expression of chemokines and receptors returned to the baseline levels observed at D0. Hence, this first exhaustive study of chemokine and chemokine receptor mRNA expression kinetics reports early expression of monocyte/macrophage-related chemokines and their receptors during the development of LVH in rats, followed by regulation of inflammation as LVH progresses

The AGC kinase inhibitor H89 attenuates airway inflammation in mouse models of asthma.

H89 is a potent inhibitor of Protein Kinase A (PKA) and Mitogen- and Stress-Activated protein Kinase 1 (MSK1) with some inhibitory activity on other members of the AGC kinase family. H89 has been extensively used in vitro but its anti-inflammatory potential in vivo has not been reported to date. To assess the anti-inflammatory properties of H89 in mouse models of asthma.Mice were sensitized intraperitoneally (i.p.) to ovalbumin (OVA) with or without alum, and challenged intranasally with OVA. H89 (10 mg/kg) or vehicle was given i.p. two hours before each OVA challenge. Airway hyperresponsiveness (AHR) was assessed by whole-body barometric plethysmography. Inflammation was assessed by the total and differential cell counts and IL-4 and IL-5 levels in bronchoalveolar lavage (BAL) fluid. Lung inflammation, mucus production and mast cell numbers were analyzed after histochemistry. We show that treatment with H89 reduces AHR, lung inflammation, mast cell numbers and mucus production. H89 also inhibits IL-4 and IL-5 production and infiltration of eosinophils, neutrophils and lymphocytes in BAL fluid.Taken together, our findings implicate that blockade of AGC kinases may have therapeutic potential for the treatment of allergic airway inflammation

Antagonizing the CX3CR1 Receptor Markedly Reduces Development of Cardiac Hypertrophy After Transverse Aortic Constriction in Mice

Left-ventricular hypertrophy, characterized by cardiomyocyte hypertrophy, interstitial cell proliferation, and immune cell infiltration, is a high risk factor for heart failure and death. Chemokines interacting with G protein-coupled chemokine receptors probably play a role in left-ventricular hypertrophy development by promoting recruitment of activated leukocytes and modulating left-ventricular remodeling. Using the minimally invasive model of transverse aortic constriction in mice, we demonstrated that a variety of chemokine and chemokine receptor messenger Ribonucleic Acid are overexpressed in the early and late phase of hypertrophy progression. Among the chemokine receptors, Cx3cr1 and Ccr2 were most strongly overexpressed and were significantly upregulated at 3, 7, and 14 days after transverse aortic constriction. Ligands of CX3CR1 (Cx3cl1) and CCR2 (Ccl2, Ccl7, Ccl12) were significantly overexpressed in the left ventricle at the early stages after mechanical pressure overload. Pharmacological inhibition of CX3CR1 signaling using the antagonist AZD8797 led to a significant reduction of hypertrophy, whereas inhibition of CCR2 with the RS504393 antagonist did not show any effect. Furthermore, AZD8797 treatment reduced the expression of the hypertrophic marker genes Nppa and Nppb as well as the profibrotic genes Tgfb1 and Col1a1 at 14 days after transverse aortic constriction. These findings strongly suggest the involvement of the CX3CR1/CX3CL1 pathway in the pathogenesis of left-ventricular hypertrophy

Effect of H89 on mucus cell hyperplasia in the lung. A.

<p>Periodic acid Schiff (PAS)-stained lung sections demonstrating hyperplasia of mucus-producing goblet cells 24 hours after the last OVA challenge (magnification × 200). (<b>B–C</b>) Mucus score in lung sections from control (Ctr) and OVA sensitized/challenged (OVA) mice treated with vehicle (black blocks) or H89 (grey blocks) in the acute (<b>B</b>) and moderate (<b>C</b>) asthma models. Data represent mean values ± SEM (bars) from <i>n</i> = 6 mice per group. **<i>P</i><0.01 and ***<i>P</i><0.001 <i>vs</i> corresponding controls; ^##<i>P</i><0.01 and ^###<i>P</i><0.001 <i>vs</i> group indicated.</p

Effect of H89 on Th2 cytokine levels in BAL fluid.

<p>BAL fluid was collected 24 hours after the last OVA challenge. The levels of IL-4 (<b>A–B</b>) and IL-5 (<b>C–D</b>) were determined using ELISA in the acute (<b>A & C</b>) and moderate (<b>B & D</b>) asthma models in control (Ctr) and OVA-sensitized/challenged (OVA) mice treated with vehicle (black blocks) or H89 (grey blocks). Data represent mean values ± SEM (bars) from <i>n</i> = 6−8 mice per group. *<i>P</i><0.05, **<i>P</i><0.01 and ***<i>P</i><0.001 <i>vs</i> corresponding controls; ^#<i>P</i><0.05 and ^##<i>P</i><0.01 <i>vs</i> group indicated.</p

Effect of H89 on the development of airway hyperreactivity in the acute asthma model. A–B.

<p>Penh responses to aerosolized methacholine in control mice (square) and OVA-sensitized/challenged mice (circle) treated with vehicle (black) or H89 (10 mg/kg) (grey) in the acute (<b>A</b>) and moderate (<b>B</b>) asthma models. (B = baseline). Data represent mean values ± SEM (bars) from <i>n</i> = 6−9 mice for control groups and <i>n</i> = 12 mice for OVA sensitized/challenged groups (OVA). *<i>P</i><0.05 and ***<i>P</i><0.001 <i>vs</i> corresponding controls; ^###<i>P</i><0.001 <i>vs</i> group indicated; NS: not significant.</p