Proenkephalin system in human polymorphonuclear cells. Production and release of a novel 1.0-kD peptide derived from synenkephalin.

Abstract

In the hematopoietic system a pluripotent stem cell generates precursors for lymphoid and myeloid lineages. Proenkephalinderived peptides were previously detected in differentiated lymphoid cells. We have studied whether the proenkephalin system is expressed in a typical differentiated cell of the myeloid lineage, the neutrophil. Human peripheral polymorphonuclear cells contain and release proenkephalin-derived peptides. The opioid portion of proenkephalin (met-enkephalincontaining peptides) was incompletely processed, resulting in the absence of low molecular weight products. The nonopioid synenkephalin (proenkephalin 1-70) molecule was completely processed to a 1.0-kD peptide derived from the COOH-terminal. This molecule was characterized in neutrophils by biochemical and immunocytochemical methods. The chemotactic peptide FMLP and the calcium ionophore A23187 induced the release of the proenkephalin-derived peptides, and this effect was potentiated by cytochalasin B. The materials secreted were similar to those present in the cell, although in the supernatant a higher proportion corresponded to more processed products. The 1.0-kD peptide was detected in human, bovine, and rat neutrophils, but the chromatographic pattern of synenkephalin-derived peptides suggests a differential posttranslational processing among species. These findings demonstrate the existence of the proenkephalin system in human neutrophils and the production and release of a novel 1.0-kD peptide derived from the synenkephalin molecule. The presence of opioid peptides in neutrophils suggests their participation in the inflammatory process, including a local analgesic effect. (J.

Presence of chromogranin-derived antimicrobial peptides in plasma during coronary artery bypass surgery and evidence of an immune origin of these peptides

“…These results are in the favor of a release of the immunoreactive material in the extracellular medium, probably by exocytosis ( Figure 3C). Because the presence of the PEA protein has been previously demonstrated in monocytes, 25 enkelytin (PEA 220-237) antiserum was also used. An intense signal having the same features as CGB labeling was detected ( Figure 3E).…”

Processing of Proenkephalin-A in Bovine Chromaffin Cells

“…Several publications described a different processing in other tissues such as brain (59), breast tumor cell lines (60), adenomas (61), bone marrow, and immune cells (62)(63)(64). PEA processing was described to be dependent on the age of the patients (65) or to stress (18,66) and to be directly related to the proteolytic enzyme expressions that may depend on various environmental conditions (60).…”

Schmerz und Immunsystem: Freund oder Feind?

“…Die Freisetzung von Opioidpeptiden aus Granulozyten ist bisher noch kaum untersucht. Es ist lediglich nachgewiesen, dass eine Aktivierung von Granulozyten zu einer Sekretion von ENK führt [57]. Zusammengefasst können zumindest einige Immunzellsubpopulationen nach Stimulation mit CRF und IL-1 spezifisch Opioidpeptide sezernieren und hierdurch analgetisch wirken.…”