3-(4-dimethylamino-naphthalen-1-ylmethylene)-1-3-dihydro-indol-2-one and Disease-Models--Animal

Expansion of renal lymphatic networks, or lymphangiogenesis (LA), is well recognized during development and is now being implicated in kidney diseases. Although LA is associated with multiple pathological conditions, very little is known about its role in acute kidney injury. The purpose of this study was to evaluate the role of LA in a model of cisplatin-induced nephrotoxicity. LA is predominately regulated by vascular endothelial growth factor (VEGF)-C and VEGF-D, ligands that exert their function through their cognate receptor VEGF receptor 3 (VEGFR3). We demonstrated that use of MAZ51, a selective VEGFR3 inhibitor, caused significantly worse structural and functional kidney damage in cisplatin nephrotoxicity. Apoptotic cell death and inflammation were also increased in MAZ51-treated animals compared with vehicle-treated animals following cisplatin administration. Notably, MAZ51 caused significant upregulation of intrarenal phospho-NF-κB, phospho-JNK, and IL-6. Cisplatin nephrotoxicity is associated with vascular congestion due to endothelial dysfunction. Using three-dimensional tissue cytometry, a novel approach to explore lymphatics in the kidney, we detected significant vascular autofluorescence attributed to erythrocytes in cisplatin alone-treated animals. Interestingly, no such congestion was detected in MAZ51-treated animals. We found increased renal vascular damage in MAZ51-treated animals, whereby MAZ51 caused a modest decrease in the endothelial markers endomucin and von Willebrand factor, with a modest increase in VEGFR2. Our findings identify a protective role for de novo LA in cisplatin nephrotoxicity and provide a rationale for the development of therapeutic approaches targeting LA. Our study also suggests off-target effects of MAZ51 on the vasculature in the setting of cisplatin nephrotoxicity.

Topics: Animals; Apoptosis; Cisplatin; Disease Models, Animal; Indoles; Inflammation Mediators; Interleukin-6; JNK Mitogen-Activated Protein Kinases; Kidney; Kidney Diseases; Lymphangiogenesis; Lymphatic Vessels; Male; Mice, Inbred C57BL; Naphthalenes; NF-kappa B; Phosphorylation; Protein Kinase Inhibitors; Signal Transduction; Vascular Endothelial Growth Factor Receptor-3

Topics: Animals; Biopsy; Cell Line, Tumor; Cell Proliferation; Disease Models, Animal; Gene Expression Profiling; Human Umbilical Vein Endothelial Cells; Humans; Indoles; Lymph Nodes; Lymphoma; Lymphotoxin beta Receptor; Lymphotoxin-alpha; Mice; Mice, Transgenic; Naphthalenes; Naphthyridines; Neovascularization, Pathologic; Signal Transduction; Tumor Microenvironment; Vascular Endothelial Growth Factor C; Vascular Endothelial Growth Factor Receptor-3; Xenograft Model Antitumor Assays

Acute myeloid leukemia (AML) cells in vivo are constantly exposed to lymphangiogenic cytokines such as VEGF-C. However, it is poorly understood how the VEGF-C signaling modulates the immune functions in the tumor microenvironment. We have previously reported that natural killer (NK) cells in AML patients strongly upregulated VEGFR-3, the major VEGF-C receptor, and that the VEGFR-3 expression level in NK cells inversely correlates with their cytotoxic potential. These findings have led us to hypothesize that VEGFR-3 inhibition may reinstate the cytotoxic capacity of the AML-associated NK cells. To address this hypothesis, we employed a pharmaceutical approach to block the VEGFR-3 function in the murine model of syngeneic myelogenous leukemia. Using various molecular and cellular analyses, we assessed the correlation between VEGFR-3 inhibition and NK cell cytotoxicity. Indeed, we found that leukemic environment is highly enriched with lymphangiogenic stimuli, and that VEGFR-3 inhibition restored NK cell killing function with an increased IFN-γ level, providing a therapeutic implication of VEGFR-3 against AML. Together, we demonstrate the therapeutic value of functional modulation of NK cells by blocking VEGFR-3, and provide a possibility of advanced therapeutic approaches using immune cells against myelogenous leukemia.

Topics: Animals; Cell Line, Tumor; Cytotoxicity, Immunologic; Disease Models, Animal; Indoles; Interferon-gamma; Killer Cells, Natural; Leukemia, Myeloid, Acute; Mice; Mice, Inbred C57BL; Naphthalenes; RNA, Small Interfering; Transfection; Vascular Endothelial Growth Factor Receptor-3