title: Leishmania infantum-chagasi activates SHP-1 and reduces NFAT5/TonEBP activity in the mouse kidney inner medulla.
abstract: Visceral leishmaniasis patients have been reported to have a urine concentration defect. Concentration of urine by the renal inner medulla is essentially dependent on a transcription factor, NFAT5/TonEBP, because it activates expression of osmoprotective genes betaine/glycine transporter 1 (BGT1) and sodium/myo-inositol transporter (SMIT), and water channel aquaporin-2, all of which are imperative for concentrating urine. Leishmania parasites evade macrophage immune defenses by activating protein tyrosine phosphatases, among which SHP-1 is critical. We previously demonstrated that SHP-1 inhibits tonicity-dependent activation of NFAT5/TonEBP in HEK293 cells through screening a genome-wide small interfering (si) RNA library against phosphatases (Zhou X, Gallazzini M, Burg MB, Ferraris JD. Proc Natl Acad Sci USA 107: 7072-7077, 2010). We sought to examine whether Leishmania can activate SHP-1 and inhibit NFAT5/TonEBP activity in the renal inner medulla in a murine model of visceral leishmaniasis by injection of female BALB/c mice with a single intravenous dose of 5 × 10(5) L. chagasi metacyclic promastigotes. We found that SHP-1 is expressed in the kidney inner medulla. L. chagasi activates SHP-1 with an increase in stimulatory phosphorylation of SHP-1-Y536 in the region. L. chagasi reduces expression of NFAT5/TonEBP mRNA and protein as well as expression of its targeted genes: BGT1, SMIT, and aquaporin-2. The culture supernatant from L. chagasi metacyclic promastigotes increases SHP-1 protein abundance and potently inhibits NFAT5 transcriptional activity in mIMCD3 cells. However, L. chagasi in our animal model has no significant effect on urinary concentration. We conclude that L. chagasi, most likely through its secreted virulence factors, activates SHP-1 and reduces NFAT5/TonEBP gene expression, which leads to reduced NFAT5/TonEBP transcriptional activity in the kidney inner medulla.
authors.affiliation: Department of Medicine, Uniformed Services University of Health Sciences, Bethesda, Maryland xiaoming.zhou@usuhs.edu.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Medicine, Uniformed Services University of Health Sciences, Bethesda, Maryland.
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Medicine, Uniformed Services University of Health Sciences, Bethesda, Maryland.
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Koles
authors.affiliation: Department of Medicine, Uniformed Services University of Health Sciences, Bethesda, Maryland.
authors.forename: Aihong
authors.initials: A
authors.lastname: Zhang
authors.affiliation: Department of Medicine, Uniformed Services University of Health Sciences, Bethesda, Maryland.
authors.forename: Naomi E
authors.initials: NE
authors.lastname: Aronson
mesh_terms: D000818:Animals; D051399:Aquaporin 2 / Q000378:metabolism; D002460:Cell Line; D004195:Disease Models, Animal; D005260:Female; D050485:GABA Plasma Membrane Transport Proteins / Q000378:metabolism; D005786:Gene Expression Regulation; D007671:Kidney Concentrating Ability / Q000502:physiology; D007672:Kidney Cortex / Q000378:metabolism / Q000469:parasitology / Q000473:pathology; D007679:Kidney Medulla / Q000378:metabolism* / Q000469:parasitology* / Q000473:pathology; D018314:Leishmania infantum / Q000502:physiology*; D007898:Leishmaniasis, Visceral / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6 / Q000378:metabolism*; D050796:STAT3 Transcription Factor / Q000378:metabolism; D027981:Symporters / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D051399:Aquaporin 2; D050485:GABA Plasma Membrane Transport Proteins; C492200:Nfat5 protein, mouse; C508355:SLC5A3 protein, mouse; D050796:STAT3 Transcription Factor; C490439:Slc6a12 protein, mouse; C494087:Stat3 protein, mouse; D027981:Symporters; D014157:Transcription Factors; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; C509248:Ptpn6 protein, mouse
keywords: ERK1/2; aquaporin-2; leishmaniasis; urinary concentration; virulence factors