Fig. 3: Glutamine-derived aspartate upregulates HIF-1α expression via the polyamine synthesis pathway and hypusination of eIF5A. | Experimental & Molecular Medicine

Fig. 3: Glutamine-derived aspartate upregulates HIF-1α expression via the polyamine synthesis pathway and hypusination of eIF5A.

From: Glutamine-derived aspartate is required for eIF5A hypusination-mediated translation of HIF-1α to induce the polarization of tumor-associated macrophages

Fig. 3: Glutamine-derived aspartate upregulates HIF-1α expression via the polyamine synthesis pathway and hypusination of eIF5A.

a Relative mRNA expression of ASS1 in TAMs and M2 macrophages. b Levels of ASS1 and ASNS in TAMs and M2 macrophages. c Levels of HIF-1α, ARG1, CD80, and CD204 in TAMs with or without silencing of ASS1 or OAT. d Levels of HIF-1α, ARG1, CD80, and CD204 in TAMs with or without silencing of ASNS. e, f Relative ornithine (e) and spermidine (f) levels in TAMs in the presence or absence of BPTES or aspartate. g Level of eIF5A hypusinated by DHPS in TAMs and M2 macrophages. h Level of hypusinated eIF5A in TAMs in the presence or absence of BPTES or aspartate. i Levels of hypusinated eIF5A, HIF-1α, ARG1, CD80, and CD204 in TAMs in the presence or absence of BPTES or spermidine. j Levels of hypusinated eIF5A, HIF-1α, ARG1, CD80, and CD204 in TAMs in the presence or absence of GC7. k Relative expression of the mRNAs encoding HIF-1α and ARG1 in TAMs in the presence or absence of GC7. l Levels of eIF5A and HIF-1α in TAMs with or without silencing of eIF5A. m, n Nascent proteins expressed by TAMs in the presence or absence of GC7 (m), as well as in the presence or absence of BPTES or aspartate (n), were labeled for 4 h with L-azidohomoalanine (AHA), biotinylated via a click reaction, and pulled down for western blotting. o Schematic showing the WT mHIF-1α-FLAG and mutant mHIF-1α-FLAG constructs. p Level of FLAG in WT mHIF-1α-FLAG- or mutant mHIF-1α-FLAG-transfected HEK293T cells in the presence or absence of GC7. The data are expressed as the mean ± SEM of three independent experiments. N.S. not significant, *p < 0.05; **p < 0.01; and ***p < 0.001. CM conditioned medium, ASS1 argininosuccinate synthase, ASNS asparagine synthetase, OAT ornithine aminotransferase, ASP aspartate, SPD spermidine.

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