Up-regulation of macrophage inwardly rectifying potassium channel Kir2.1 contributes to macrophage activation and cardiac inflammatory injury
10.3969/j.issn.1000-4718.2025.10.002
- VernacularTitle:上调巨噬细胞内向整流钾通道Kir2.1对巨噬细胞活化和心肌细胞炎性损伤的作用
- Author:
Shi GAO
1
;
Biyao QIAO
;
Jiaxin WANG
;
Fu LIU
;
Qinghua LIU
Author Information
1. 山西医科大学病理生理教研室,山西 太原 030001
- Publication Type:Journal Article
- Keywords:
inwardly rectifying potassium channels;
myocardial infarction;
macrophages;
inflammation;
JAK2/STAT3 signaling pathway
- From:
Chinese Journal of Pathophysiology
2025;41(10):1882-1891
- CountryChina
- Language:Chinese
-
Abstract:
AIM:To investigate the roles of up-regulated inwardly rectifier potassium channel 2.1(Kir2.1)in macrophage activation and cardiac inflammatory injury,in order to clarify the mechanism of Kir2.1 regulation in inflam-matory injury and cardiac repair.METHODS:The RAW264.7 macrophages were activated by lipopolysacharide(LPS)and treated with Kir2.1 agonist zacopride or lentivirus-Kir2.1 overexpression(Kir2.1-OE).Macrophages were randomly divided into control,LPS,LPS+zacopride(or LPS+Kir2.1-OE),and LPS+zacopride+BaCl2 groups.The effects of Kir2.1-OE and AG490[Janus kinase 2(JAK2)inhibitor]on the JAK2/signal transducer and activator of transcription 3(STAT3)signaling pathway in macrophages were also investigated.The expression of CD86,interleukin-6(IL-6)and Kir2.1 in M1 macrophages was detected by RT-qPCR or immunofluorescence staining.The expression of JAK2/STAT3 molecules was detected by Western blot.The RAW264.7 macrophages were incubated with LPS,LPS+zacopride or LPS+zacopride+BaCl2 for 12 h,and then co-cultured with H9C2(2-1)cardiomyocytes for 48 h.The expression of Kir2.1,IL-4,IL-6,IL-1β,B-cell lymphoma-2(Bcl-2),Bcl-2-associated X protein(Bax),caspase-3,cleaved caspase-3,calcium/calmodulin-dependent protein kinase II(CaMKII)and p-CaMKII in cardiomyocytes was detected by Western blot.We fur-ther compared the effects of zacopride and KN-93,a known CaMKII inhibitor,on cardiac CaMKII.After being incubated with LPS for 12 h and changed the medium,RAW264.7 macrophages were co-cultured with H9C2(2-1)cardiomyocytes which was pretreated with KN-93.The cardiomyocytes were divided into control,LPS,and LPS+KN-93 groups.The ex-pression of CaMKII and p-CaMKII were detected by Western blot.RESULTS:Zacopride inhibited LPS-induced M1-type polarization of macrophages in a Kir2.1-dependent manner as showed by a significant decrease in CD86(M1-type marker)and IL-6(P<0.05).Zacopride or Kir2.1-OE inhibited LPS-induced activation of JAK2/STAT3 inflammatory signaling pathway in macrophages,with effects similar to the JAK2 inhibitor AG490.The H9C2(2-1)cardiomyocytes were co-cul-tured with M1-polarized macrophages(P<0.05).Zacopride inhibited M1 macrophage-induced inflammatory injury in car-diomyocytes,which was manifested as decreased expression of IL-1β and IL-6,increased expression of IL-4,and de-creased apoptosis.Zacopride also inhibited activation of CaMKII in a Kir2.1-dependent manner in H9C2(2-1)cells co-cultured with macrophages(P<0.05).CONCLUSION:Up-regulation of Kir2.1 may inhibit LPS-induced M1-type polar-ization of macrophages via inhibiting JAK2/STAT3 signaling pathway.Up-regulation of macrophage Kir2.1 may play a pro-tective role in cardiac repair after myocardial infarction by negative regulation of CaMKII signaling.
