Leptin signaling in human peripheral blood mononuclear cells, activation of p38 and p42/44 mitogen-activated protein (MAP) kinase and p70 S6 kinase.
The adipocyte-derived hormone leptin plays an important role as a relayer of nutritional status to several organ systems. Evidence is accumulating that leptin plays an important role in the adequate functioning and maintenance of the immune system. Here we show that leptin induces sustained phosphorylation of p38 MAP kinase in human peripheral blood mononuclear cells (PBMCs). We show furthermore that leptin induces two routes to phosphorylation of the 40S ribosomal protein S6, one is activation of the p90 ribosomal S6 kinase (RSK) via the MEK/p42/p44 MAP kinase pathway, the other is via activation of p70 S6 kinase. Thus, these results give new insight in the mechanism that underlies the immunomodulatory effects of leptin.
Department of Experimental Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands.
G R
GR
van den Brink
T
T
O'Toole
J C
JC
Hardwick
D E
DE
van den Boogaardt
H H
HH
Versteeg
S J
SJ
van Deventer
M P
MP
Peppelenbosch
D016895:Culture Media, Serum-Free; D006801:Humans; D015151:Immunoblotting; D020738:Leptin / Q000378:metabolism / Q000494:pharmacology*; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000502:physiology; D020935:MAP Kinase Signaling System / Q000187:drug effects* / Q000502:physiology; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D019893:Ribosomal Protein S6 Kinases / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases
D016895:Culture Media, Serum-Free; D020738:Leptin; D011518:Proto-Oncogene Proteins; D014409:Tumor Necrosis Factor-alpha; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D019893:Ribosomal Protein S6 Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases