TY - JOUR
T1 - Azotemia, TNFα, and LPS prime the human neutrophil oxidative burst by distinct mechanisms
AU - Mcleish, Kenneth R.
AU - Klein, Jon B.
AU - Lederer, Eleanor D.
AU - Head, Kimberly Z.
AU - Ward, Richard A.
N1 - Funding Information:
We gratefully acknowledge the technical assistance of Laura Gordon. [a-P32]azidoanilide-GTP was graciously provided by Dr. John Raymond (Duke University, Durham, NC, USA). This work was supported in part by grants from the Baxter Healthcare Corporation Extramural Grant Program (KRM, JBK, and RAW), the Department of Veterans Affairs (KRM and JBK), the Kentucky Affiliate of the American Heart Associa-tion (EDL and KRM), and the Jewish Hospital of Louisville Foundation (EDL, KRM, and JBK). Portions of this work were presented at the 27th and 28th Annual Meetings of the American Society of Nephrology and have been published in abstract form (JAm Soc Nephrol 5:590, 1994 and 6:1034, 1995, respectively).
PY - 1996
Y1 - 1996
N2 - The oxidative burst of neutrophils from azotemic patients (AzoPMNs) is primed for an enhanced response compared to neutrophils from normal subjects (NorPMNs). The mechanism for this priming is unknown, although TNFα does not further prime AzoPMNs. The present study examines the hypothesis that azotemia and TNFα prime neutrophils by the same mechanism. Formyl peptide receptor expression and degranulation were not primed in AzoPMNs, but were primed by both LPS and TNFα. LPS was also able to prime the AzoPMN oxidative burst. Guanine nucleotide exchange by multiple guanine nucleotide binding proteins, including heterotrimeric G-proteins and low molecular weight GTP-binding proteins (LMWGs), was increased in AzoPMNs, as demonstrated by GTPγS binding and azidoanilide GTP photoaffinity labeling. The plasma membrane density of G-protein α(i2), α(i3), and α(s) subunits and the density in the cytosol of the LMWG, Rac2, did not differ between AzoPMNs and NorPMNs. However, the LMWG, Rap1A, was present in significantly greater amounts on plasma membranes from AzoPMNs. FMet-Leu-Phe-stimulated phospholipase D activity, but not basal activity, was significantly greater in AzoPMNs. Finally, incubation of NorPMNs in plasma from azotemic patients resulted in a significant increase in basal GTPγS binding. These results demonstrate that priming of AzoPMNs is restricted to oxidative burst activity and that it occurs by a mechanism distinct from that utilized by TNFα and LPS. While the exact mechanism remains unknown, it appears to involve a plasma factor and changes in LMWG expression or activity.
AB - The oxidative burst of neutrophils from azotemic patients (AzoPMNs) is primed for an enhanced response compared to neutrophils from normal subjects (NorPMNs). The mechanism for this priming is unknown, although TNFα does not further prime AzoPMNs. The present study examines the hypothesis that azotemia and TNFα prime neutrophils by the same mechanism. Formyl peptide receptor expression and degranulation were not primed in AzoPMNs, but were primed by both LPS and TNFα. LPS was also able to prime the AzoPMN oxidative burst. Guanine nucleotide exchange by multiple guanine nucleotide binding proteins, including heterotrimeric G-proteins and low molecular weight GTP-binding proteins (LMWGs), was increased in AzoPMNs, as demonstrated by GTPγS binding and azidoanilide GTP photoaffinity labeling. The plasma membrane density of G-protein α(i2), α(i3), and α(s) subunits and the density in the cytosol of the LMWG, Rac2, did not differ between AzoPMNs and NorPMNs. However, the LMWG, Rap1A, was present in significantly greater amounts on plasma membranes from AzoPMNs. FMet-Leu-Phe-stimulated phospholipase D activity, but not basal activity, was significantly greater in AzoPMNs. Finally, incubation of NorPMNs in plasma from azotemic patients resulted in a significant increase in basal GTPγS binding. These results demonstrate that priming of AzoPMNs is restricted to oxidative burst activity and that it occurs by a mechanism distinct from that utilized by TNFα and LPS. While the exact mechanism remains unknown, it appears to involve a plasma factor and changes in LMWG expression or activity.
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U2 - 10.1038/ki.1996.330
DO - 10.1038/ki.1996.330
M3 - Article
C2 - 8840267
AN - SCOPUS:0029833382
SN - 0085-2538
VL - 50
SP - 407
EP - 416
JO - Kidney international
JF - Kidney international
IS - 2
ER -