Protein Kinase C Isoforms in Neutrophil Adhesion and Activation

Abstract

Neutrophils are the first line of defense against bacterial and mycotic pathogens. In order to reach the pathogens, neutrophils need to transmigrate through the vascular endothelium and migrate to the site of infection. Defense strategies against pathogens include phagocytosis, production and release of oxygen radicals through the oxidative burst, and degranulation of antimicrobial and inflammatory molecules. Protein kinase C (PKC)-δ is required for full assembly of NADPH oxidase and activation of the respiratory burst. Neutrophils also express PKC-α and -β, which may be involved in adhesion, degranulation and phagocytosis, but the evidence is not conclusive yet. This review focuses on the potential impact of protein kinase C isoforms on neutrophil adhesion and activation.

Molecular Mechanisms of N-Formyl-Methionyl-Leucyl-Phenylalanine-Induced Superoxide Generation and Degranulation in Mouse Neutrophils: Phospholipase D Is Dispensable

“…Data are means Ϯ SEM from three independent experiments. tion and degranulation in neutrophils (58,59). The results shown above, taken together with these reports, indicate that cPKC or nPKC rather than PLD is a key molecule regulating these neutrophil functions.…”

Protein Kinase C-θ Is Required for Murine Neutrophil Recruitment and Adhesion Strengthening under Flow

“…Using pseudosubstrate inhibition, the atypical isoform protein kinase C (PKC)-z has been implicated in outside-in signaling downstream of the b 2 integrin Mac-1 (13), but Mac-1 has no known role in neutrophil adhesion under flow. The functional role of PKC has not yet been investigated in the context of neutrophil adhesion to the vascular endothelium (14).…”

“…Using knockout strategies, PKC isoforms have been implicated in a multitude of diseases and organ dysfunctions, including inflammatory processes (20). In this study, we investigate the role of PKC-u, a novel PKC isoform (14), which is calcium-insensitive, but activated by 1,2-diacylglycerol or phorbol esters, in neutrophil adhesion. The main PKC isoforms expressed in neutrophils are thought to be PKC-a, PKC-b, PKC-d, and PKC-z (21,22).…”

May the variable magnetic field and pulse red light induce synergy effects in respiratory burst of neutrophils in vitro?

“…The neutrophil oxidative burst can be activated by a number of different soluble and particulate stimuli, including chemoattractants, certain cytokines, phorbol esters, calcium ionophores, different lectins, and opsonized as well as various unopsonized microorganisms [1,3]. The NADPH oxidase enzymatic complex assembles on the plasma (or phagosome) membrane of granulocytes, macrophages and B cells upon stimulation [4,5]. The neutrophil NADPH oxidase consists of the catalytic subunit gp91 phox , which is located at the phagosome membrane together with p22 phox .…”

“…phox and small GTP-ase Rac2 results in rapid production of superoxide [1,4,6,7]. The phagocyte NADPH oxidase produces superoxide anion (O 2·− ) which is a precursor to other ROS by the electrogenic process of moving electrons across the cell membrane [8,5,3].…”