Jnk1 deficiency in hematopoietic cells suppresses macrophage apoptosis and increases atherosclerosis in low-density lipoprotein receptor null mice

Babaev, V. R.
Yeung, M.
Erbay, E.
Ding, L.
Zhang, Y.
May, J. M.
Fazio, S.
Hotamisligil, G. S.
Linton, M. F.
Source Title
Arteriosclerosis, Thrombosis, and Vascular Biology
Print ISSN
Electronic ISSN
Lippincott Williams and Wilkins
1122 - 1131
Journal Title
Journal ISSN
Volume Title

Objective - The c-Jun NH 2 -terminal kinases (JNK) are regulated by a wide variety of cellular stresses and have been implicated in apoptotic signaling. Macrophages express 2 JNK isoforms, JNK1 and JNK2, which may have different effects on cell survival and atherosclerosis. Approach and Results - To dissect the effect of macrophage JNK1 and JNK2 on early atherosclerosis, Ldlr-/- mice were reconstituted with wild-type, Jnk1-/-, and Jnk2-/- hematopoietic cells and fed a high cholesterol diet. Jnk1-/- →Ldlr-/- mice have larger atherosclerotic lesions with more macrophages and fewer apoptotic cells than mice transplanted with wild-type or Jnk2-/- cells. Moreover, genetic ablation of JNK to a single allele (Jnk1+/- /Jnk2-/- or Jnk1-/- /Jnk2+/-) in marrow of Ldlr-/- recipients further increased atherosclerosis compared with Jnk1-/- →Ldlr-/- and wild-type→Ldlr-/- mice. In mouse macrophages, anisomycin-mediated JNK signaling antagonized Akt activity, and loss of Jnk1 gene obliterated this effect. Similarly, pharmacological inhibition of JNK1, but not JNK2, markedly reduced the antagonizing effect of JNK on Akt activity. Prolonged JNK signaling in the setting of endoplasmic reticulum stress gradually extinguished Akt and Bad activity in wild-type cells with markedly less effects in Jnk1-/- macrophages, which were also more resistant to apoptosis. Consequently, anisomycin increased and JNK1 inhibitors suppressed endoplasmic reticulum stress-mediated apoptosis in macrophages. We also found that genetic and pharmacological inhibition of phosphatase and tensin homolog abolished the JNK-mediated effects on Akt activity, indicating that phosphatase and tensin homolog mediates crosstalk between these pathways. Conclusions - Loss of Jnk1, but not Jnk2, in macrophages protects them from apoptosis, increasing cell survival, and this accelerates early atherosclerosis.

Other identifiers
Book Title
Apoptosis, Atherosclerosis, Endoplasmic reticulum stress, Macrophages, MAP kinase signaling system, Anisomycin, Anthra[1,9 cd]pyrazol 6(2h) one, Insulin, JNKI1, Low density lipoprotein receptor, Mitogen activated protein kinase p38, Phosphatidylinositol 3,4,5 trisphosphate 3 phosphatase, Protein kinase B, Stress activated protein kinase 1, Unclassified drug, Bad protein, mouse, Low density lipoprotein receptor, Mitogen activated protein kinase 9, Protein BAD, Protein kinase B, Protein kinase inhibitor, Pten protein, mouse, Stress activated protein kinase 1, Allele, Animal cell, Animal experiment, Animal model, Apoptosis, Article, Atherosclerosis, Cholesterol diet, Controlled study, Endoplasmic reticulum stress, Enzyme activity, Enzyme deficiency, Enzyme inhibition, Gene repression, Hematopoietic cell, Macrophage, Mouse, Nonhuman, Priority journal, Signal transduction, Animal, Antagonists and inhibitors, Aorta, Aortic disease, Apoptosis, Atherosclerosis, Atherosclerotic plaque, Bone marrow cell, Bone marrow transplantation, C57BL mouse, Cell culture, Cell survival, Deficiency, Disease model, Drug effects, Enzymology, Genetic predisposition, Genetics, Hypercholesterolemia, Knockout mouse, Lipid diet, Metabolism, Pathology, Phenotype, Animals, Aorta, Aortic Diseases, Apoptosis, Atherosclerosis, Bcl-Associated Death Protein, Bone Marrow Cells, Bone Marrow Transplantation, Cell Survival, Cells, Cultured, Diet, High-Fat, Disease Models, Animal, Endoplasmic Reticulum Stress, Genetic Predisposition to Disease, Hypercholesterolemia, Macrophages, Inbred C57BL, Knockout, Mitogen-Activated Protein Kinase 8, Mitogen-Activated Protein Kinase 9, Phenotype, Atherosclerotic, Protein Kinase Inhibitors, Proto-Oncogene Proteins c-akt, PTEN Phosphohydrolase, Receptors, Signal Transduction
Published Version (Please cite this version)