Altered regulation of cytosolic Ca2+ concentration in dendritic cells from klotho hypomorphic mice

Ekaterina Shumilina, Meerim K. Nurbaeva, Wenting Yang, Evi Schmid, Kalina Szteyn, Antonella Russo, Nicole Heise, Christina Leibrock, Nguyen Thi Xuan, Caterina Faggio, Makoto Kuro-o, Florian Lang

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

The function of dendritic cells (DCs), antigen-presenting cells regulating naïve T-cells, is regulated by cytosolic Ca2+ concentration ([Ca2+]i). [Ca2+]i is increased by store-operated Ca2+ entry and decreased by K+-independent (NCX) and K+-dependent (NCKX) Na+/Ca2+ exchangers. NCKX exchangers are stimulated by immunosuppressive 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], the biologically active form of vitamin D. Formation of 1,25(OH)2D3 is inhibited by the antiaging protein Klotho. Thus 1,25(OH)2D3 plasma levels are excessive in Klotho-deficient mice (klothohm). The present study explored whether Klotho deficiency modifies [Ca2+]i regulation in DCs. DCs were isolated from the bone marrow of klothohm mice and wild-type mice (klotho+/+) and cultured for 7-9 days with granulocyte-macrophage colony-stimulating factor. According to major histocompatibility complex II (MHC II) and CD86 expression, differentiation and lipopolysaccharide (LPS)-induced maturation were similar in klothohm DCs and klotho+/+ DCs. However, NCKX1 membrane abundance and NCX/NCKX-activity were significantly enhanced in klothohm DCs. The [Ca2+]i increase upon acute application of LPS (1 μg/ml) was significantly lower in klothohm DCs than in klotho+/+ DCs, a difference reversed by the NCKX blocker 3′,4′-dichlorobenzamyl (DBZ; 10 μM). CCL21-dependent migration was significantly less in klothohm DCs than in klotho+/+ DCs but could be restored by DBZ. NCKX activity was enhanced by pretreatment of klotho+/+ DC precursors with 1,25(OH)2D3 the first 2 days after isolation from bone marrow. Feeding klothohm mice a vitamin D-deficient diet decreased NCKX activity, augmented LPS-induced increase of [Ca2+]i, and enhanced migration of klothohm DCs, thus dissipating the differences between klothohm DCs and klotho+/+ DCs. In conclusion, Klotho deficiency upregulates NCKX1 membrane abundance and Na+/Ca2+-exchange activity, thus blunting the increase of [Ca2+]i following LPS exposure and CCL21-mediated migration. The effects are in large part due to excessive 1,25(OH)2D3 formation.

Original languageEnglish (US)
Pages (from-to)C70-C77
JournalAmerican Journal of Physiology - Cell Physiology
Volume305
Issue number1
DOIs
StatePublished - Jul 1 2013

Keywords

  • CCL21
  • Lipopolysaccharides
  • Migration
  • NCKX
  • SOCE

ASJC Scopus subject areas

  • Physiology
  • Cell Biology

Fingerprint

Dive into the research topics of 'Altered regulation of cytosolic Ca<sup>2+</sup> concentration in dendritic cells from klotho hypomorphic mice'. Together they form a unique fingerprint.

Cite this