Regulation of M2-type Pyruvate Kinase Mediated by the High-affinity IgE Receptors is Required for Mast Cell Degranulation
Overview
Affiliations
Background And Purpose: M2-type pyruvate kinase (M2PK) was found to interact directly with the 'ITAM' region of the gamma chain of the high-affinity IgE receptor (FcvarepsilonRI). Our hypothesis was that mast cell degranulation might require the FcvarepsilonRI-mediated inhibition of M2PK activity.
Experimental Approach: In rat basophilic leukaemia (RBL-2H3) cells, the effects of directly inhibiting M2PK or preventing the FcvarepsilonRI-mediated inhibition of M2PK (disinhibition) on degranulation was measured by hexosaminidase release. Effects of blocking the FcvarepsilonRI-mediated inhibition of M2PK was also assessed in vivo in a mouse model of allergen-induced airway hyper-responsiveness.
Key Results: Activation of FcvarepsilonRI in RBL-2H3 cells caused the rapid phosphorylation of tyrosine residues in M2PK, associated with a decrease in M2PK enzymatic activity. There was an inverse correlation between M2PK activity and mast cell degranulation. FcvarepsilonRI-mediated inhibition of M2PK involved Src kinase, phosphatidylinositol 3-kinase, PKC and calcium. Direct inhibition of M2PK potentiated FcvarepsilonRI-mediated degranulation and prevention of the FcvarepsilonRI-mediated inhibition of M2PK attenuated mast cell degranulation. Transfection of RBL-2H3 cells with M1PK which prevents FcvarepsilonRI-induced inhibition of M2PK, markedly reduced their degranulation and exogenous M1PK (i.p.) inhibited ovalbumin-induced airway hyper-responsiveness in vivo.
Conclusions And Implications: We have identified a new control point and a novel biochemical pathway in the process of mast cell degranulation. Our study suggests that the FcvarepsilonRI-mediated inhibition of M2PK is a crucial step in responses to allergens. Moreover, the manipulation of glycolytic processes and intermediates could provide novel strategies for the treatment of allergic diseases.
Mast Cells in Upper and Lower Airway Diseases: Sentinels in the Front Line.
Costanzo G, Costanzo G, Del Moro L, Nappi E, Pelaia C, Puggioni F Int J Mol Sci. 2023; 24(11).
PMID: 37298721 PMC: 10253288. DOI: 10.3390/ijms24119771.
Research progress on the role of PKM2 in the immune response.
Liu C, Liu C, Fu R Front Immunol. 2022; 13:936967.
PMID: 35967360 PMC: 9365960. DOI: 10.3389/fimmu.2022.936967.
Goretzki A, Zimmermann J, Lin Y, Schulke S Front Allergy. 2022; 3:825931.
PMID: 35386646 PMC: 8974690. DOI: 10.3389/falgy.2022.825931.
Pyruvate Kinase, Inflammation and Periodontal Disease.
Grant M Pathogens. 2021; 10(7).
PMID: 34206267 PMC: 8308603. DOI: 10.3390/pathogens10070784.
Cellular Energetics of Mast Cell Development and Activation.
Mendoza R, Fudge D, Brown J Cells. 2021; 10(3).
PMID: 33801300 PMC: 7999080. DOI: 10.3390/cells10030524.