A novel complement C3 inhibitor CP40-KK protects against experimental pulmonary arterial hypertension via an inflammasome NLRP3 associated pathway

• Published in: Journal of translational medicine Vol. 22; no. 1; pp. 164 - 13
• Main Authors: Dai, Lei, Chen, Yu, Wu, Jinhua, He, Zhen, Zhang, Yueqi, Zhang, Wenjun, Xie, Yang, Zeng, Hesong, Zhong, Xiaodan
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 16.02.2024; BioMed Central; BMC
• Subjects: Affinity; Analysis; Animals; Care and treatment; Cell activation; Cell proliferation; Complement activation; Complement C3; Complement C3 - metabolism; Complement component C3; Complement Inactivating Agents - adverse effects; Complement Inactivating Agents - metabolism; CP40-KK; Cytokines; Cytokines - metabolism; Diagnosis; Disease; Disease Models, Animal; Enzyme-linked immunosorbent assay; Growth factors; Heart; Hemodynamics; Humans; Hypertension; Hypertension, Pulmonary; Hypertrophy; Hypoxia; IL-1β; Immunofluorescence; Immunohistochemistry; Infiltration; Inflammasomes; Inflammasomes - metabolism; Inflammation; Interleukin 18; Interleukin-18 - metabolism; Laboratory animals; Macrophages; Medical research; Monocrotaline; NLR Family, Pyrin Domain-Containing 3 Protein - metabolism; NLRP3; Peptides; Proinflammatory cytokine; Pulmonary arterial hypertension; Pulmonary Arterial Hypertension - drug therapy; Pulmonary arteries; Pulmonary Artery - metabolism; Pulmonary hypertension; Rats; Smooth muscle; Surface plasmon resonance; Veins & arteries; Western blotting; China; Australia; NLRP3; Pulmonary arterial hypertension; CP40-KK; Complement C3; Proinflammatory cytokine
• ISSN: 1479-5876; 1479-5876
• DOI: 10.1186/s12967-023-04741-z

Pulmonary arterial hypertension (PAH) is a severe cardiopulmonary disease characterized by complement dependent and proinflammatory activation of macrophages. However, effective treatment for complement activation in PAH is lacking. We aimed to explore the effect and mechanism of CP40-KK (a newly identified analog of selective complement C3 inhibitor CP40) in the PAH model. We used western blotting, immunohistochemistry, and immunofluorescence staining of lung tissues from the monocrotaline (MCT)-induced rat PAH model to study macrophage infiltration, NLPR3 inflammasome activation, and proinflammatory cytokines (IL-1β and IL-18) release. Surface plasmon resonance (SPR), ELISA, and CH50 assays were used to test the affinity between CP40-KK and rat/human complement C3. CP40-KK group rats only received CP40-KK (2 mg/kg) by subcutaneous injection at day 15 to day 28 continuously. C3a was significantly upregulated in the plasma of MCT-treated rats. SPR, ELISA, and CH50 assays revealed that CP40-KK displayed similar affinity binding to human and rat complement C3. Pharmacological inhibition of complement C3 cleavage (CP40-KK) could ameliorate MCT-induced NLRP3 inflammasome activity, pulmonary vascular remodeling, and right ventricular hypertrophy. Mechanistically, increased proliferation of pulmonary arterial smooth muscle cells is closely associated with macrophage infiltration, NLPR3 inflammasome activation, and proinflammatory cytokines (IL-1β and IL-18) release. Besides, C3a enhanced IL-1β activity in macrophages and promoted pulmonary arterial smooth muscle cell proliferation in vitro. Our findings suggest that CP40-KK treatment was protective in the MCT-induced rat PAH model, which might serve as a therapeutic option for PAH.