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Background: There is increasing interest in developing FPR2 agonists (compound 43, ACT‐389949 and BMS‐986235) as potential pro‐resolving therapeutics, with ACT‐389949 and BMS‐986235 having entered phase I clinical development. FPR2 activation leads to diverse downstream outputs. ACT‐389949 was observed to cause rapid tachyphylaxis, while BMS‐986235 and compound 43 induced cardioprotective effects in preclinical models. We aim to characterise the differences in ligand‐receptor engagement and downstream signalling and trafficking bias profile. Experimental Approach: Concentration‐response curves to G protein dissociation, β‐arrestin recruitment, receptor trafficking and second messenger signalling were generated using FPR2 ligands (BMS‐986235, ACT‐389949, compound 43 and WKYMVm), in HEK293A cells. Log(τ/KA) was obtained from the operational model for bias analysis using WKYMVm as a reference ligand. Docking of FPR2 ligands into the active FPR2 cryoEM structure (PDBID: 7T6S) was performed using ICM pro software. Key Results: Bias analysis revealed that WKYMVm and ACT‐389949 shared a very similar bias profile. In comparison, BMS‐986235 and compound 43 displayed approximately 5‐ to 50‐fold bias away from β‐arrestin recruitment and trafficking pathways, while being 35‐ to 60‐fold biased towards cAMP inhibition and pERK1/2. Molecular docking predicted key amino acid interactions at the FPR2 shared between WKYMVm and ACT‐389949, but not with BMS‐986235 and compound 43. Conclusion and Implications: In vitro characterisation demonstrated that WKYMVm and ACT‐389949 differ from BMS‐986235 and compound 43 in their signalling and protein coupling profile. This observation may be explained by differences in the ligand‐receptor interactions. In vitro characterisation provided significant insights into identifying the desired bias profile for FPR2‐based pharmacotherapy. [ABSTRACT FROM AUTHOR]

Aims Formylpeptide receptors (FPRs) play a critical role in the regulation of inflammation, an important driver of hypertension-induced end-organ damage. We have previously reported that the biased FPR small-molecule agonist, compound17b (Cmpd17b), is cardioprotective against acute, severe inflammatory insults. Here, we reveal the first compelling evidence of the therapeutic potential of this novel FPR agonist against a longer-term, sustained inflammatory insult, i.e. hypertension-induced end-organ damage. The parallels between the murine and human hypertensive proteome were also investigated. Methods and results The hypertensive response to angiotensin II (Ang II, 0.7 mg/kg/day, s.c.) was attenuated by Cmpd17b (50 mg/kg/day, i.p.). Impairments in cardiac and vascular function assessed via echocardiography were improved by Cmpd17b in hypertensive mice. This functional improvement was accompanied by reduced cardiac and aortic fibrosis and vascular calcification. Cmpd17b also attenuated Ang II-induced increased cardiac mitochondrial complex 2 respiration. Proteomic profiling of cardiac and aortic tissues and cells, using label-free nano-liquid chromatography with high-sensitivity mass spectrometry, detected and quantified ∼6000 proteins. We report hypertension-impacted protein clusters associated with dysregulation of inflammatory, mitochondrial, and calcium responses, as well as modified networks associated with cardiovascular remodelling, contractility, and structural/cytoskeletal organization. Cmpd17b attenuated hypertension-induced dysregulation of multiple proteins in mice, and of these, ∼110 proteins were identified as similarly dysregulated in humans suffering from adverse aortic remodelling and cardiac hypertrophy. Conclusion We have demonstrated, for the first time, that the FPR agonist Cmpd17b powerfully limits hypertension-induced end-organ damage, consistent with proteome networks, supporting development of pro-resolution FPR-based therapeutics for treatment of systemic hypertension complications. [ABSTRACT FROM AUTHOR]

Background and Purpose: Pulmonary arterial hypertension (PAH), a rare fatal disorder characterised by inflammation, vascular remodelling and vasoconstriction. Current vasodilator therapies reduce pulmonary arterial pressure but not mortality. The G‐protein coupled formyl peptide receptors (FPRs) mediates vasodilatation and resolution of inflammation, actions possibly beneficial in PAH. We investigated dilator and anti‐inflammatory effects of the FPR biased agonist compound 17b in pulmonary vasculature using mouse precision‐cut lung slices (PCLS). Experimental Approach: PCLS from 8‐week‐old male and female C57BL/6 mice, intrapulmonary arteries were pre‐contracted with 5‐HT for concentration–response curves to compound 17b and 43, and standard‐of‐care drugs, sildenafil, iloprost and riociguat. Compound 17b‐mediated relaxation was assessed with FPR antagonists or inhibitors and in PCLS treated with TNF‐α or LPS. Cytokine release from TNF‐α‐ or LPS‐treated PCLS ± compound 17b was measured. Key Results: Compound 17b elicited concentration‐dependent vasodilation, with potencies of iloprost > compound 17b = riociguat > compound 43 = sildenafil. Compound 17b was inhibited by the FPR1 antagonist cyclosporin H but not by soluble guanylate cyclase, nitric oxide synthase or cyclooxygenase inhibitors. Under inflammatory conditions, the efficacy and potency of compound 17b were maintained, while iloprost and sildenafil were less effective. Additionally, compound 17b inhibited secretion of PAH‐relevant cytokines via FPR2. Conclusions and Implications: Vasodilation to compound 17b but not standard‐of‐care vasodilators, is maintained under inflammatory conditions, with additional inhibition of PAH‐relevant cytokine release. This provides the first evidence that targeting FPR, with biased agonist, simultaneously targets vascular function and inflammation, supporting the development of FPR‐based pharmacotherapy to treat PAH. LINKED ARTICLES: This article is part of a themed issue Therapeutic Targeting of G Protein‐Coupled Receptors: hot topics from the Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists 2021 Virtual Annual Scientific Meeting. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.14/issuetoc [ABSTRACT FROM AUTHOR]

Left ventricular (LV) dysfunction is an early, clinically detectable sign of cardiomyopathy in type 2 diabetes mellitus (T2DM) that precedes the development of symptomatic heart failure. Preclinical models of diabetic cardiomyopathy are essential to develop therapies that may prevent or delay the progression of heart failure. This study examined the molecular, structural, and functional cardiac phenotype of two rat models of T2DM induced by a high-fat diet (HFD) with a moderate- or high-sucrose content (containing 88.9 or 346 g/kg sucrose, respectively), plus administration of low-dose streptozotocin (STZ). At 8 wk of age, male Sprague-Dawley rats commenced a moderate- or high-sucrose HFD. Two weeks later, rats received low-dose STZ (35 mg/kg ip for 2 days) and remained on their respective diets. LV function was assessed by echocardiography 1 wk before end point. At 22 wk of age, blood and tissues were collected postmortem. Relative to chow-fed sham rats, diabetic rats on a moderate- or high-sucrose HFD displayed cardiac reactive oxygen species dysregulation, perivascular fibrosis, and impaired LV diastolic function. The diabetes-induced impact on LV adverse remodeling and diastolic dysfunction was more apparent when a high-sucrose HFD was superimposed on STZ. In conclusion, a high-sucrose HFD in combination with low-dose STZ produced a cardiac phenotype that more closely resembled T2DM-induced cardiomyopathy than STZ diabetic rats subjected to a moderate-sucrose HFD. NEW & NOTEWORTHY Left ventricular dysfunction and adverse remodeling were more pronounced in diabetic rats that received low-dose streptozotocin (STZ) and a high-sucrose high-fat diet (HFD) compared with those on a moderate-sucrose HFD in combination with STZ. Our findings highlight the importance of sucrose content in diet composition, particularly in preclinical studies of diabetic cardiomyopathy, and demonstrate that low-dose STZ combined with a high-sucrose HFD is an appropriate rodent model of cardiomyopathy in type 2 diabetes.