PMID- 12388069 OWN - NLM STAT- MEDLINE DCOM- 20030225 LR - 20211203 IS - 0363-6143 (Print) IS - 0363-6143 (Linking) VI - 284 IP - 2 DP - 2003 Feb TI - NO and TNF-alpha released from activated macrophages stabilize HIF-1alpha in resting tubular LLC-PK1 cells. PG - C439-46 AB - Hypoxic/ischemic conditions provoke activation of the transcription factor hypoxia-inducible factor-1 (HIF-1). HIF-1 is composed of HIF-1alpha (subjected to protein stability regulation) and constitutively expressed HIF-1beta. Besides hypoxia, diverse agonists are identified that stabilize HIF-1alpha during normoxia. Here we used a coculture system of RAW 264.7 macrophage cells and tubular LLC-PK(1) cells to establish that lipopolysaccharide- and interferon-gamma-stimulated but not resting macrophages elicited HIF-1alpha accumulation in LLC-PK(1) cells. Via pharmacological interventions such as blockade of nitric oxide (NO) production in macrophages, scavenging of NO with the use of 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, or application of tumor necrosis factor-alpha (TNF-alpha)-neutralizing antibodies, we identified NO and TNF-alpha as signaling molecules. Working in concert, NO and TNF-alpha have a stronger response when allowed direct cell-to-cell contact instead of contact with only the cell supernatant of activated macrophages. We show that signal transmission by NO with TNF-alpha in LLC-PK(1) cells is mediated via the phosphatidylinositol 3-kinase (PI3-K)/Akt pathway, because it is blocked by wortmannin or dominant-negative forms of PI3-K as well as protein kinase B. We conclude that NO and TNF-alpha, derived from activated macrophages, provoke HIF-1alpha stabilization in LLC-PK(1) cells under normoxic conditions, which underscores HIF-1alpha stabilization due to intercellular regulation. FAU - Zhou, Jie AU - Zhou J AD - Department of Cell Biology, Faculty of Biology, University of Kaiserslautern, 67663 Kaiserslautern, Germany. FAU - Fandrey, Joachim AU - Fandrey J FAU - Schumann, Jens AU - Schumann J FAU - Tiegs, Gisa AU - Tiegs G FAU - Brune, Bernhard AU - Brune B LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20020925 PL - United States TA - Am J Physiol Cell Physiol JT - American journal of physiology. Cell physiology JID - 100901225 RN - 0 (Enzyme Inhibitors) RN - 0 (Free Radical Scavengers) RN - 0 (Hypoxia-Inducible Factor 1, alpha Subunit) RN - 0 (Inflammation Mediators) RN - 0 (Phosphoinositide-3 Kinase Inhibitors) RN - 0 (Proto-Oncogene Proteins) RN - 0 (Transcription Factors) RN - 0 (Tumor Necrosis Factor-alpha) RN - 31C4KY9ESH (Nitric Oxide) RN - EC 2.7.11.1 (Protein Serine-Threonine Kinases) RN - EC 2.7.11.1 (Proto-Oncogene Proteins c-akt) SB - IM MH - Animals MH - Cell Communication/physiology MH - Chemotaxis, Leukocyte/drug effects/physiology MH - Coculture Techniques MH - Enzyme Inhibitors/pharmacology MH - Epithelial Cells/drug effects/*metabolism MH - Free Radical Scavengers/pharmacology MH - Hypoxia/metabolism/physiopathology MH - Hypoxia-Inducible Factor 1, alpha Subunit MH - Inflammation/metabolism/physiopathology MH - Inflammation Mediators/metabolism MH - Kidney Tubules/drug effects/*metabolism MH - LLC-PK1 Cells MH - Macrophages/drug effects/*metabolism MH - Nitric Oxide/*metabolism MH - Phosphatidylinositol 3-Kinases/metabolism MH - Phosphoinositide-3 Kinase Inhibitors MH - *Protein Serine-Threonine Kinases MH - Proto-Oncogene Proteins/antagonists & inhibitors/metabolism MH - Proto-Oncogene Proteins c-akt MH - Signal Transduction/physiology MH - Swine MH - Transcription Factors/*metabolism MH - Tumor Necrosis Factor-alpha/*metabolism EDAT- 2002/10/22 04:00 MHDA- 2003/02/26 04:00 CRDT- 2002/10/22 04:00 PHST- 2002/10/22 04:00 [pubmed] PHST- 2003/02/26 04:00 [medline] PHST- 2002/10/22 04:00 [entrez] AID - 00294.2002 [pii] AID - 10.1152/ajpcell.00294.2002 [doi] PST - ppublish SO - Am J Physiol Cell Physiol. 2003 Feb;284(2):C439-46. doi: 10.1152/ajpcell.00294.2002. Epub 2002 Sep 25.