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Development and Characterization of Treprostinil Palmitil Inhalation Aerosol for the Investigational Treatment of Pulmonary Arterial Hypertension

by Adam J. Plaunt, Sadikul Islam, Tony Macaluso, Helena Gauani, Thomas Baker, Donald Chun, Veronica Viramontes, Christina Chang, Michel R. Corboz, Richard W. Chapman, Zhili Li, David C. Cipolla, Walter R. Perkins and Vladimir S. Malinin

Treprostinil palmitil (TP) is a prodrug of treprostinil (TRE), a pulmonary vasodilator that has been previously formulated for inhaled administration via a nebulizer. TP demonstrates a sustained presence in the lungs with reduced systemic exposure and prolonged inhibition of hypoxia-induced pulmonary vasoconstriction in vivo. Here, we report on re-formulation efforts to develop a more convenient solution-based metered-dose inhaler (MDI) formulation of TP, a treprostinil palmitil inhalation aerosol (TPIA) that matches the pharmacokinetic (PK) and efficacy profile of a nebulized TP formulation, treprostinil palmitil inhalation suspension (TPIS)…

Novel inhibitor ZED3197 as potential drug candidate in anticoagulation targeting coagulation FXIIIa (F13a)

by Ralf Pasternack, Christian Büchold, Robert Jähnig, Christiane Pelzer, Michael Sommer, Andreas Heil, Peter Florian, Götz Nowak, Uwe Gerlach, Martin Hils

Factor XIII (FXIII) is the final enzyme of the coagulation cascade. While the other enzymatic coagulation factors are proteases, FXIII belongs to the transglutaminase family. FXIIIa covalently crosslinks the fibrin clot and represents a promising target for drug development to facilitate fibrinolysis. However, no FXIII-inhibiting compound has entered clinical trials. Here, we introduce the features of a peptidomimetic inhibitor of FXIIIa (ZED3197) as a potential drug candidate.

The complex lipid, SPPCT-800, reduces lung damage, improves pulmonary function and decreases pro-inflammatory cytokines in the murine LPS-induced acute respiratory distress syndrome (ARDS) model

by Peter P. Sordillo, Andrea Allaire, Annie Bouchard, Dan Salvail & Sebastien M. Labbe

Acute respiratory distress syndrome (ARDS) is a highly fatal, inflammatory condition of lungs with multiple causes. There is no adequate treatment. SPPCT-800 was effective in reducing manifestations of ARDS. SPPCT-800 should be further investigated as therapy for ARDS, especially in longer duration or higher cumulative dose studies.

Comparison of the activity of TPIP, inhaled and intravenous TRE, and oral selexipag in a Sugen5416/hypoxia (Su/Hx) rat model of pulmonary arterial hypertension

by Michel R. Corboz, Adam J. Plaunt, Vladimir S. Malinin, Zhili Li, Helena Gauani, Donald Chun, David Cipolla, Walter R. Perkins, and Richard W. Chapman

ABSTRACT Treprostinil palmitil (TP), a long-acting inhaled pulmonary vasodilator prodrug of treprostinil (TRE), has beneficial effects in a Sugen5416/hypoxia (Su/Hx) rat model of pulmonary arterial hypertension (PAH) that compare favorably to the oral phosphodiesterase 5 inhibitor (PDE5 ) sildenafil. In this study in male Sprague-Dawley rats, a dry powder formulation of TP (TPIP) was compared with inhaled and intravenous TRE and oral selexipag to evaluate inhibition of hemodynamic and pathologic changes in the lungs and heart induced by Su/Hx challenge. Su (20 mg/kg) was injected subcutaneously followed by 3 weeks of Hx (10% O2/balance N2) and then initiation of test article administration over 5 weeks with room air breathing. Hemodynamics and histopathology were measured at the end of the study. Su/Hx challenge approximately doubled the mean pulmonary arterial blood pressure (mPAP) and the Fulton index, decreased cardiac output (CO), doubled the wall thickness and muscularization of the small (10–50 lm) and medium (51–100 lm) sized pulmonary arteries, and increased the percentage of obliterated pulmonary blood vessels. Even though inhaled TRE (65 lg/kg, 4× daily), intravenous TRE (810 ng/kg/min), and oral selexipag (30 mg/kg, twice daily) provided some beneficial effects against the Su/Hx challenge, the overall benefit was generally greater with TPIP at high dose (117 lg/kg, once daily). These results demonstrate that TPIP compares favorably to inhaled and intravenous TRE and oral selexipag with respect to inhibition of the pathophysiological changes induced by Su/Hx challenge in rats.

Inhaled hexadecyl-treprostinil provides pulmonary vasodilator activity at significantly lower plasma concentrations than infused treprostinil

by Richard W Chapman 1 , Zhili Li 2 , Michel R Corboz 2 , Helena Gauani 2 , Adam J Plaunt 2 , Donna M Konicek 2 , Franziska G Leifer 2 , Charles E Laurent 3 , Han Yin 3 , Dany Salvail 3 , Chad Dziak 4 , Walter R Perkins 2 , Vladimir Malinin 2

Abstract INS1009 is a long acting pulmonary vasodilator prodrug of treprostinil (TRE) that is formulated in a lipid nanoparticle for inhaled delivery by nebulization. This study examined the ability of INS1009 to inhibit vasoconstriction in the pulmonary vasculature of rats and dogs and the extent to which local activity within the lung contributes to its activity. Rats received a single dose of INS1009 by nose-only inhalation or were given a continuous intravenous (i.v.) infusion of TRE, followed by an i.v. challenge of the thromboxane mimetic pulmonary vasoconstrictor U46619 and the increase in pulmonary arterial pressure (PAP) was measured. In beagle dogs, INS1009 was given by inhalation via face mask and TRE was given by continuous i.v. infusion; vasoconstriction was then induced by inhaled hypoxia with reduction of FIO2 to 0.10. Changes in the dog’s right ventricular pulse pressure (RVPP) were measured using implanted telemetry probes. Blood samples were collected in rats and dogs immediately after the challenge to measure the plasma TRE concentration. Exposure of rats to inhaled INS1009 (0.5, 3.0 and 20.9 μg/kg) inhibited the U46619-induced increase in PAP at all doses up to 6 h with statistically significant inhibition up to 24 h with the pooled dose-response data. The concentration of TRE in the plasma at which PAP was reduced by 50% was approximately 60-fold lower for INS1009 (EC50 = 0.08 ng/mL) as compared to i.v. TRE (EC50 = 4.9 ng/mL). In dogs, INS1009 (2.7-80.9 μg/kg) inhibited the hypoxia-induced increase in RVPP at all doses up to 6 h with activity once again observed with the pooled dose-response of 10 μg/kg and higher at 24 h. The concentration of TRE in the plasma at which RVPP was reduced by 50% was approximately 550-fold lower for INS1009 (EC50 = 0.0075 ng/mL) as compared to i.v. TRE (EC50 = 4.1 ng/mL). These studies, in two species and by two different pulmonary vasoconstrictor challenges, demonstrate that inhaled INS1009 not only has long-acting vasodilatory effects but also that the local activity within the lung contributes to this response. Therefore, INS1009 may offer the opportunity to effect pulmonary vasodilation for long periods but with substantially lower systemic exposure than infused TRE. Keywords: Dogs; Hexadecyl-treprostinil prodrug; Local lung effect; Pulmonary vasodilation; Rats; Treprostinil.

A Systematic Exploration of Macrocyclization in Apelin-13: Impact on Binding, Signaling, Stability, and Cardiovascular Effects

by Kien Trân 1 2 , Alexandre Murza 1 2 , Xavier Sainsily 1 2 , David Coquerel 3 2 , Jérôme Côté 1 2 , Karine Belleville 1 2 , Lounès Haroune 1 2 , Jean-Michel Longpré 1 2 , Robert Dumaine 1 2 , Dany Salvail 4 , Olivier Lesur 3 2 , Mannix Auger-Messier 3 , Philippe Sarret 1 2 , Éric Marsault 1

Abstract The apelin receptor generates increasing interest as a potential target across several cardiovascular indications. However, the short half-life of its cognate ligands, the apelin peptides, is a limiting factor for pharmacological use. In this study, we systematically explored each position of apelin-13 to find the best position to cyclize the peptide, with the goal to improve its stability while optimizing its binding affinity and signaling profile. Macrocyclic analogues showed a remarkably higher stability in rat plasma (half-life >3 h versus 24 min for Pyr-apelin-13), accompanied by improved affinity (analogue 15, Ki 0.15 nM and t1/2 6.8 h). Several compounds displayed higher inotropic effects ex vivo in the Langendorff isolated heart model in rats (analogues 13 and 15, maximum response at 0.003 nM versus 0.03 nM of apelin-13). In conclusion, this study provides stable and active compounds to better characterize the pharmacology of the apelinergic system.

NTP42, a novel antagonist of the thromboxane receptor, attenuates experimentally induced pulmonary arterial hypertension

by Eamon P Mulvaney 1 , Helen M Reid 1 2 , Lucia Bialesova 1 , Annie Bouchard 3 , Dany Salvail 3 , B Therese Kinsella 4 5

Abstract Background: NTP42 is a novel antagonist of the thromboxane prostanoid receptor (TP), currently in development for the treatment of pulmonary arterial hypertension (PAH). PAH is a devastating disease with multiple pathophysiological hallmarks including excessive pulmonary vasoconstriction, vascular remodelling, inflammation, fibrosis, in situ thrombosis and right ventricular hypertrophy. Signalling through the TP, thromboxane (TX) A2 is a potent vasoconstrictor and mediator of platelet aggregation. It is also a pro-mitogenic, pro-inflammatory and pro-fibrotic agent. Moreover, the TP also mediates the adverse actions of the isoprostane 8-iso-prostaglandin F2α, a free-radical-derived product of arachidonic acid produced in abundance during oxidative injury. Mechanistically, TP antagonists should treat most of the hallmarks of PAH, including inhibiting the excessive vasoconstriction and pulmonary artery remodelling, in situ thrombosis, inflammation and fibrosis. This study aimed to investigate the efficacy of NTP42 in the monocrotaline (MCT)-induced PAH rat model, alongside current standard-of-care drugs. Methods: PAH was induced by subcutaneous injection of 60 mg/kg MCT in male Wistar-Kyoto rats. Animals were assigned into groups: 1. ‘No MCT’; 2. ‘MCT Only’; 3. MCT + NTP42 (0.25 mg/kg BID); 4. MCT + Sildenafil (50 mg/kg BID), and 5. MCT + Selexipag (1 mg/kg BID), where 28-day drug treatment was initiated within 24 h post-MCT. Results: From haemodynamic assessments, NTP42 reduced the MCT-induced PAH, including mean pulmonary arterial pressure (mPAP) and right systolic ventricular pressure (RSVP), being at least comparable to the standard-of-care drugs Sildenafil or Selexipag in bringing about these effects. Moreover, NTP42 was superior to Sildenafil and Selexipag in significantly reducing pulmonary vascular remodelling, inflammatory mast cell infiltration and fibrosis in MCT-treated animals. Conclusions: These findings suggest that NTP42 and antagonism of the TP signalling pathway have a relevant role in alleviating the pathophysiology of PAH, representing a novel therapeutic target with marked benefits over existing standard-of-care therapies. Keywords: Monocrotaline; NTP42; PAH; Prostanoid; Pulmonary arterial hypertension; Thromboxane; Thromboxane receptor antagonist.

Prostanoid receptor subtypes involved in treprostinil-mediated vasodilation of rat pulmonary arteries and in treprostinil-mediated inhibition of collagen gene expression of human lung fibroblasts

by Michel R Corboz 1 , William Salvail 2 , Sandra Gagnon 3 , Daniel LaSala 4 , Charles E Laurent 5 , Dany Salvail 6 , Kuan-Ju Chen 7 , David Cipolla 8 , Walter R Perkins 9 , Richard W Chapman 10

Treprostinil (TRE) is a potent pulmonary vasodilator with effects on other pathological aspects of pulmonary arterial hypertension. In this study, the prostanoid receptors involved in TRE-induced relaxation of isolated rat pulmonary arteries and TRE-induced inhibition of increased gene expression in collagen synthesis and contractility of human lung fibroblasts were determined. TRE (0.01-100 μM) relaxed prostaglandin F2α-precontracted rat pulmonary arteries which was attenuated by denudation of the vascular endothelium. TRE-induced relaxation was predominantly blocked by the IP receptor antagonist RO3244194 (1 μM), with slightly greater inhibition in endothelium-denuded tissue. At higher TRE concentrations (> 1 μM), the DP1 receptor antagonist BW A868C (1 μM) also inhibited relaxation reaching significance above 10 μM. In contrast, the EP3 receptor antagonist L798106 (1 μM) accentuated TRE-induced relaxation of pulmonary arteries with intact endothelium. In human lung fibroblasts, the EP2 receptor antagonist PF-04418948 (1 μM) blocked transforming growth factor β1 (TGF-β1)-increased expression of collagen synthesis (COL1A1 and COL1A2) and fibroblast contractility (ACTG2) genes in presence of TRE (0.1 μM). In conclusion, the IP receptor located on rat pulmonary vascular smooth muscle and endothelium is the primary receptor mediating vasorelaxation, while the DP1 receptor present on the rat endothelium is involved only at higher TRE concentrations. In human lung fibroblasts, the EP2 receptor is the dominant receptor subtype involved in suppression of increased collagen synthesis and fibroblast contractility gene expression induced by TGF-β1 in the presence of TRE. Keywords: Lung fibroblasts; Prostanoid receptors; Pulmonary arteries; Pulmonary hypertension; Treprostinil.

Inhaled Treprostinil-Prodrug Lipid Nanoparticle Formulations Provide Long-Acting Pulmonary Vasodilation

by Franziska G Leifer 1 1 2 , Donna M Konicek 1 1 2 , Kuan-Ju Chen 1 , Adam J Plaunt 1 , Dany Salvail 2 , Charles E Laurent 2 , Michel R Corboz 1 , Zhili Li 1 , Richard W Chapman 1 , Walter R Perkins 1 , Vladimir S Malinin 1

Treprostinil (TRE), a prostanoid analogue approved in the USA for the treatment of pulmonary arterial hypertension, requires continuous infusion or multiple dosing sessions per day for inhaled and oral routes of administration due to its short half-life. The inhaled drug is known to induce adverse systemic and local effects including headache, nausea, cough, and throat irritation which may be due at least in part to transiently high drug concentrations in the lungs and plasma immediately following administration [1]. To ameliorate these side effects and reduce dosing frequency we designed an inhaled slow-release TRE formulation. TRE was chemically modified to be an alkyl prodrug (TPD) which was then packaged into a lipid nanoparticle (LNP) carrier. Preclinical screening in a rat model of hypoxia-induced pulmonary vasoconstriction led to selection of a 16-carbon alkyl ester derivative of TRE. The TPD-LNP demonstrated approximately 10-fold lower TRE plasma Cmax compared to inhaled TRE solution while maintaining an extended vasodilatory effect. The favorable PK profile is attributed to gradual dissociation of TPD from the LNP and subsequent conversion to TRE. Together, this sustained presentation of TRE to the lungs and plasma is consistent with a once- or twice-daily dosing schedule in the absence of high Cmax-associated adverse events which could provide patients with an improved treprostinil therapy.

Gαi-biased apelin analog protects against isoproterenol-induced myocardial dysfunction in rats

by David Coquerel 1 , Eugénie Delile 1 , Lauralyne Dumont 1 , Frédéric Chagnon 1 , Alexandre Murza 2 , Xavier Sainsily 1 2 , Dany Salvail 3 , Philippe Sarret 2 , Eric Marsault 2 , Mannix Auger-Messier 1 , Olivier Lesur 1

Apelin receptor (APJ) activation by apelin-13 (APLN-13) engages both Gαi proteins and β-arrestins, stimulating distinct intracellular pathways and triggering physiological responses like enhanced cardiac contractility. Substituting the C-terminal phenylalanine of APLN-13 with α-methyl-l-phenylalanine [(l-α-Me)Phe] or p-benzoyl-l-phenylalanine (Bpa) generates biased analogs inducing APJ functional selectivity toward Gαi proteins. Using these original analogs, we proposed to investigate how the canonical Gαi signaling of APJ regulates the cardiac function and to assess their therapeutic impact in a rat model of isoproterenol-induced myocardial dysfunction. In vivo and ex vivo infusions of either Bpa or (l-α-Me)Phe analogs failed to enhance rats’ left ventricular (LV) contractility compared with APLN-13. Inhibition of Gαi with pertussis toxin injection optimized the cardiotropic effect of APLN-13 and revealed the inotropic impact of Bpa. Moreover, both APLN-13 and Bpa efficiently limited the forskolin-induced and PKA-dependent phosphorylation of phospholamban at the Ser16 in neonatal rat ventricular myocytes. However, only Bpa significantly reduced the inotropic effect of forskolin infusion in isolated-perfused heart, highlighting its efficient bias toward Gαi. Compared with APLN-13, Bpa also markedly improved isoproterenol-induced myocardial systolic and diastolic dysfunctions. Bpa prevented cardiac weight increase, normalized both ANP and BNP mRNA expressions, and decreased LV fibrosis in isoproterenol-treated rats. Our results show that APJ-driven Gαi/adenylyl cyclase signaling is functional in cardiomyocytes and acts as negative feedback of the APLN-APJ-dependent inotropic response. Biased APJ signaling toward Gαi over the β-arrestin pathway offers a promising strategy in the treatment of cardiovascular diseases related to myocardial hypertrophy and high catecholamine levels.NEW & NOTEWORTHY By using more potent Gαi-biased APJ agonists that strongly inhibit cAMP production, these data point to the negative inotropic effect of APJ-mediated Gαi signaling in the heart and highlight the potential protective impact of APJ-dependent Gαi signaling in cardiovascular diseases associated with left ventricular hypertrophy. Keywords: APJ receptor; apelin; biased ligands; cardioprotection; isoproterenol.

Preclinical Pharmacology and Pharmacokinetics of Inhaled Hexadecyl-Treprostinil (C16TR), a Pulmonary Vasodilator Prodrug

by Michel R Corboz 1 , Zhili Li 2 , Vladimir Malinin 2 , Adam J Plaunt 2 , Donna M Konicek 2 , Franziska G Leifer 2 , Kuan-Ju Chen 2 , Charles E Laurent 2 , Han Yin 2 , Marzena C Biernat 2 , Dany Salvail 2 , Jianguo Zhuang 2 , Fadi Xu 2 , Aidan Curran 2 , Walter R Perkins 2 , Richard W Chapman 2

This article describes the preclinical pharmacology and pharmacokinetics (PK) of hexadecyl-treprostinil (C16TR), a prodrug of treprostinil (TRE), formulated in a lipid nanoparticle (LNP) for inhalation as a pulmonary vasodilator. C16TR showed no activity (>10 µM) in receptor binding and enzyme inhibition assays, including binding to prostaglandin E2 receptor 2, prostaglandin D2 receptor 1, prostaglandin I2 receptor, and prostaglandin E2 receptor 4; TRE potently bound to each of these prostanoid receptors. C16TR had no effect (up to 200 nM) on platelet aggregation induced by ADP in rat blood. In hypoxia-challenged rats, inhaled C16TR-LNP produced dose-dependent (0.06-6 µg/kg), sustained pulmonary vasodilation over 3 hours; inhaled TRE (6 µg/kg) was active at earlier times but lost its effect by 3 hours. Single- and multiple-dose PK studies of inhaled C16TR-LNP in rats showed proportionate dose-dependent increases in TRE Cmax and area under the curve (AUC) for both plasma and lung; similar results were observed for dog plasma levels in single-dose PK studies. In both species, inhaled C16TR-LNP yielded prolonged plasma TRE levels and a lower plasma TRE Cmax compared with inhaled TRE. Inhaled C16TR-LNP was well tolerated in rats and dogs; TRE-related side effects included cough, respiratory tract irritation, and emesis and were seen only after high inhaled doses of C16TR-LNP in dogs. In guinea pigs, inhaled TRE (30 µg/ml) consistently produced cough, but C16TR-LNP (30 µg/ml) elicited no effect. These results demonstrate that C16TR-LNP provides long-acting pulmonary vasodilation, is well tolerated in animal studies, and may necessitate less frequent dosing than inhaled TRE with possibly fewer side effects.

RP5063, a novel, multimodal, serotonin receptor modulator, prevents monocrotaline-induced pulmonary arterial hypertension in rats

by Laxminarayan Bhat 1 , Jon Hawkinson 2 , Marc Cantillon 3 , Dasharatha G Reddy 3 , Seema R Bhat 3 , Charles E Laurent 4 , Annie Bouchard 4 , Marzena Biernat 4 , Dany Salvail 4

Abstract Pulmonary arterial hypertension (PAH), a condition characterized by pulmonary vasculature constriction and remodeling, involves dysregulation of the serotonin (5-HT) receptors 5-HT2A and 5-HT2B. A rat model of monocrotaline (MCT)-induced PAH was used to examine the potential beneficial effects of RP5063, a 5-HT receptor modulator. After a single 60mg/kg dose of MCT, rats were gavaged twice-daily (b.i.d.) with vehicle, RP5063 (1, 3, or 10mg/kg), or sildenafil (50mg/kg) for 28 days. RP5063 at a dose as low as 1mg/kg, b.i.d. reduced pulmonary resistance and increased systemic blood oxygen saturation. The highest dose of RP5063 (10mg/kg, b.i.d.) reduced diastolic, systolic, and mean pulmonary pressure, right systolic ventricular pressure, ventilatory pressure, and Fulton’s index (ratio of right to left ventricular weight). Doses as low as 3mg/kg RP5063, b.i.d. also increased weight gain and body temperature, suggesting an improvement in overall health of MCT-treated animals. Similar reductions in pulmonary, right ventricular, and ventilatory pressure, pulmonary resistance, and Fulton’s index as well as increased systemic blood oxygen saturation were observed in animals treated with the reference agent sildenafil at a higher dose (50mg/kg, b.i.d.). Histological examination revealed that RP5063 produced dose-dependent reductions in pulmonary blood vessel wall thickness and proportion of muscular vessels, similar to sildenafil. RP5063 completely blocked MCT-induced increases in the plasma cytokines TNFα, IL-1β, and IL-6 at all doses. In summary, RP5063 improved pulmonary vascular pathology and hemodynamics, right ventricular pressure and hypertrophy, systemic oxygen saturation, and overall health of rats treated with MCT. Keywords: 5-hydroxytryptamine 2B receptor; Anti-proliferative; Pulmonary arterial hypertension; RP5063; Rat monocrotaline model; Vascular remodeling.

12 Hour Hypothermic Oxygenated Machine Perfusion Preserves the Quality of Donor Hearts: A Biomarker Analysis

by Michel, Madariaga, Labbé, Dupré, Anderson, Shanmugarajah

Hypothermic oxygenated machine perfusion has been shown to be beneficial in clinical kidney and liver transplantation, but has not yet been used routinely in clinical heart transplantation….

Dual antiplatelet and anticoagulant APAC prevents experimental ischemia–reperfusion-induced acute kidney injury

by Tuuminen, Jouppila, Salvail, Laurent, Benoit, Syrjälä, Helin, Lemström, Lassila

Renal ischemia–reperfusion predisposes to acute kidney injury (AKI) and mortality. APAC, mast cell heparin proteoglycan mimetic is a potent dual antiplatelet and anticoagulant inhibiting thrombosis in several vascular models…

Preclinical Pharmacology and Pharmacokinetics of Inhaled Hexadecyl-Treprostinil (C16TR), a Pulmonary Vasodilator Prodrug

by Michel R Corboz, Zhili Li, Vladimir Malinin, Adam J Plaunt, Donna M Konicek, Franziska G Leifer, Kuan-Ju Chen, Charles E Laurent, Han Yin, Marzena C Biernat, Dany Salvail, Jianguo Zhuang, Fadi Xu, Aidan Curran, Walter R Perkins and Richard W Chapman

This article describes the preclinical pharmacology and pharmacokinetics (PK) of hexadecyl-treprostinil (C16TR), a prodrug of treprostinil (TRE), formulated in a lipid nanoparticle (LNP) for inhalation as a pulmonary vasodilator…

NTP42, a novel antagonist of the thromboxane receptor, attenuates experimentally induced pulmonary arterial hypertension

by Mulvaney EP, Reid HM, Bialesova L, Bouchard A, Salvail D, Kinsella BT.

Background: NTP42 is a novel antagonist of the thromboxane prostanoid receptor (TP), currently in development for the treatment of pulmonary arterial hypertension (PAH)…

Investigating ARDS at IPST

To investigate the molecular mechanisms of acute lung injury (ALI) or acute respiratory distress symdrome (ARDS), various experimental models have been used. The most common is the sterile inflammation model (endotoxin LPS). In experimental ARDS, the lung parenchyma is damaged by the generation and release of different mediators produced by activated lung macrophages and transmigrated neutrophils in the interstitial and alveolar compartments. The end results are microvascular injury and diffuse alveolar damage with intrapulmonary hemorrhage, edema and fibrin deposition which are also features in patients with ARDS. Effect of LPS on Body Weight and Lung Weight: LPS is well known to induce an acute and severe inflammatory response within the first few hours following the intillation with a peak around 6-8 hours following the injury. This pulmonary inflammation is associated with an important airway congestion (edema, accumulation of fluid). LPS induces a significant body weight loss associated with the inflammation and a lethargic state. Inversely, lung weight significantly increases. This increase is associated with a severe edema as indicated by an important increase of the W/D ratio. Bronchoalveolar lavage fluid (BALF): The celluar content measured from the bronchoalveolar lavage fluid (BALF) represents a reliable indicator in the diagnosis of specific interstitial lung diseases. BALF is commonly used to determine the protein and cellular composition of the materials released in the pulmonary airways during lung injury. Significant increases in total cell count, especially neutrophils, can be observed following LPS intillation. For more information: This study investigates the consequences of the onset of LPS-induced acute respiratory distress syndrome (ARDS). This LPS model is suitable to screen compounds for efficacy against acute lung injury including inflammation and the different pulmonary complications associated with ARDS. In such a study design, the dataset can confirm efficacy and potential mechanisms of action of the test article.

ELABELA Improves Cardio-Renal Outcome in Fatal Experimental Septic Shock

by David Coquerel 1 , Frédéric Chagnon, Xavier Sainsily, Lauralyne Dumont, Alexandre Murza, Jérôme Côté, Robert Dumaine, Philippe Sarret, Éric Marsault, Dany Salvail, Mannix Auger-Messier, Olivier Lesur

Abstract Objectives: Apelin-13 was recently proposed as an alternative to the recommended β-adrenergic drugs for supporting endotoxin-induced myocardial dysfunction. Since Apelin-13 signals through its receptor (Apelin peptide jejunum) to exert singular inotropic/vasotropic actions and to optimize body fluid balance, this candidate pathway might benefit septic shock management. Whether the newly discovered ELABELA (ELA), a second endogenous ligand of the Apelin peptide jejunum receptor highly expressed in the kidney, further improves cardio-renal impairment remains unknown. Design, setting, and subjects: Interventional study in a rat model of septic shock (128 adult males) to assess the effects of ELA and Apelin-13 on vascular and cardio-renal function. Experiments were performed in a tertiary care University-based research institute. Interventions: Polymicrobial sepsis-induced cardiac dysfunction was produced by cecal ligation puncture to assess hemodynamic efficacy, cardioprotection, and biomechanics under acute or continuous infusions of the apelinergic agonists ELA or Apelin-13 (39 and 15 µg/kg/hr, respectively) versus normal saline. Measurements and main results: Apelinergic agonists improved 72-hour survival after sepsis induction, with ELA providing the best clinical outcome after 24 hours. Apelinergic agonist infusion counteracted cecal ligation puncture-induced myocardial dysfunction by improving left ventricular pressure-volume relationship. ELA-treated cecal ligation puncture rats were the only group to 1) display a significant improvement in left ventricular filling as shown by increased E-wave velocity and left ventricular end-diastolic volume, 2) exhibit a higher plasma volume, and 3) limit kidney injury and free-water clearance. These beneficial renal effects were superior to Apelin-13, likely because full-length ELA enabled a distinctive regulation of pituitary vasopressin release. Conclusions: Activation of the apelinergic system by exogenous ELA or Apelin-13 infusion improves cardiovascular function and survival after cecal ligation puncture-induced sepsis. However, ELA proved better than Apelin-13 by improving fluid homeostasis, cardiovascular hemodynamics recovery, and limiting kidney dysfunction in a vasopressinergic-dependent manner.