Epithelial magnesium transport by TRPM6 is essential for prenatal development and adult survival
- Ludwig Maximilian University of Munich, Germany
- The University of Queensland, Australia
- Helmholtz Zentrum Munich, Germany
- German Institute of Human Nutrition, Germany
- German Center for Diabetes Research, Germany
- Princeton Institute of Life Sciences, United States
- University of Würzburg, Germany
- University Hospital Würzburg, Germany
- German Centre for Cardiovascular Research, Munich Heart Alliance, Germany
- German Center for Lung Research, Germany
- Rutgers Robert Wood Johnson Medical School, United States
- Comprehensive Pneumology Center Munich, German Center for Lung Research, Germany
Figures
Figure 1 with 1 supplement
Assessment of Trpm6 function in extraembryonic tissues.
(A) Survival of Trpm6βgeo/βgeo embryos obtained from Trpm6βgeo/+ intercrosses. (B) Representative images of e9.5 Trpm6+/+ (+/+, n = 13) and Trpm6βgeo/βgeo (βgeo/βgeo, n = 5) embryos from dataset in …
Figure 1—figure supplement 1
ISH on serial paraffin sections obtained from wildtype e8.5 fetus using antisense (left) and sense (right) probes for Trpm6.
Arrows indicate Trpm6-positive cells in the chorion (blue arrows) and the endoderm layer in the visceral yolk sac (black arrows) stained only by the antisense probe. Note: Trpm6 was not detectable …
Figure 2 with 2 supplements
Pathophysiological changes displayed by Trpm6-deficient adult mice.
Unless stated otherwise, 10–12 week-old Trpm6fl/+ (Control) and Trpm6Δ17/Δ17;Sox2-Cre (KO) littermates were studied. (A–E) Mice were examined for survival rate (A), overall physical appearance (B), …
Figure 2—figure supplement 1
Examination of energy balance in Trpm6-deficient mice.
Eight week-old Trpm6fl/+ (Control) and Trpm6Δ17/Δ17;Sox2-Cre (KO) littermates were evaluated for (A) chow intake as assessed by feces production, (B) energy content of feces studied by bomb …
Figure 2—figure supplement 2
Evaluation of atherosclerosis development in Trpm6-deficient mice.
An assessment of 8 week-old control (Control, n = 3) and Trpm6-deficient (KO, n = 3) with ApoE-/- mice (as a positive control, n = 1) using en-face thoracal aorta preparation and Oil-Red O staining …
Figure 3
Histology of internal organs of Trpm6-deficient mice.
Hematoxylin-eosin staining of paraffin embedded tissue sections of 12–13 week-old control (Control) and Trpm6-deficient (KO) mice maintained either on regular (0.22% Mg2+) or Mg2+ supplemented …
Figure 4 with 3 supplements
Assessment of metabolic profiles of Trpm6-deficient mice.
(A–C) 8 week-old Trpm6fl/+ (Control) and Trpm6Δ17/Δ17;Sox2-Cre (KO) littermates were evaluated for (A) serum IGF1, (B) body temperature, (C) urinary MUPs content in individual mice. Data are …
Figure 4—figure supplement 1
Gene expression profiling of Trpm6-deficient and control mice.
Heatmap diagram of differently expressed genes with FDR p≤0.1 in the liver of 12–13 week-old control (Trpm6fl/+, n = 4) vs Trpm6-deficient (Trpm6Δ17/Δ17;Sox2-Cre, n = 3) male littermates. n – number …
Figure 4—figure supplement 2
Metabolomic profiling of Trpm6-deficient and control mice.
Profiling of metabolites in the serum, liver and gastrocnemius muscle samples from 8–10 week-old control (Trpm6fl/+, n = 8) and KO (Trpm6Δ17/Δ17;Sox2-Cre, n = 6) male littermates were studied for a …
Figure 4—figure supplement 3
Assessment of the membrane potential (Δψm) in isolated mitochondria.
(A) Mitochondria isolated from the liver of wildtype C57BL/6 mice were incubated (30 min) in the presence of succinate/rotenone, octanoylcarnitine/malate or palmitoylcarnitine/malate as energy …
Figure 5 with 1 supplement
Examining of Mg2+ balance in Trpm6-deficient adult mice.
(A–F) Assessment of 8 week-old Trpm6fl/+ (Control) and Trpm6Δ17/Δ17;Sox2-Cre (KO) littermate males. (A) Mg2+ levels in bones and (B) gastrocnemius muscle assessed by ICP-MS. (C) Immunostaining of …
Figure 5—figure supplement 1
Expression pattern of Trpm6 in the intestine.
ISH on serial paraffin sections obtained from wildtype intestine using sense (left) and antisense (right) DIG-labelled probes for Trpm6. Boxes indicate the positions of the magnified images of the …
Figure 6 with 3 supplements
Characterization of TRPM6/M7-like currents in Trpm6- and Trpm7-deficient TS cells.
(A) Left panel: Whole-cell currents measured at −80 mV and +80 mV over time in Trpm6+/+ (n = 22) and Trpm6βgeo/βgeo (n = 22) TS cells. Middle panel: Representative current-voltage relationships …
Figure 6—figure supplement 1
Characterization of Trpm6-deficient TS cells.
(A) Phase-contrast images of Trpm6+/+ (+/+) and Trpm6βgeo/βgeo (βgeo/βgeo) TS cells cultured in a regular cell culture medium. (B) Expression of Trpm6 and Trpm7 in TS cells assessed by RT-PCR. (C, D)…
Figure 6—figure supplement 2
Examination of TS cells deficient in Trpm7.
(A) Phase-contrast images of Trpm7+/+ (+/+) and Trpm7Δ17/Δ17 (Δ17/Δ17) TS cells cultured in a cell culture medium supplemented by 10 mM Mg2+. (B) RT-PCR analysis of Trpm7 and Trpm6 in TS cells and …
Figure 6—figure supplement 3
Evaluation of human haploid leukaemia (HAP1) cells deficient in TRPM7.
(A) Phase-contrast images of parental (WT) and TRPM7-deficient (KO) HAP1 cells cultured in a cell culture medium supplemented with 10 mM Mg2+. (B) Western-blot analysis of TRPM7 in WT and KO HAP1 …
Figure 7
Effects of whole-life Mg2+ dietary treatments on B6C3F1 mouse strain.
(A) Mean survival ages of B6C3F1 mice maintained at a control diet (Control, n = 335), under dietary restriction (DR, n = 60), or supplemented by Mg(CH3COO)2 (MgAc, n = 15), Mg(OH)2 (n = 15), MgCl2 …
Tables
Table 1
Postnatal survival of the mice with global and tissue-restricted deletions of Trpm6.
Targeted tissue | Breeding strategy | Expected F1 outcome* | Survival of the mutant |
|---|---|---|---|
Constitutive mutagenesis | |||
Whole fetus | ♂Trpm6βgeo/+ x ♀Trpm6βgeo/+ | 25%Trpm6βgeo/βgeo 50% Trpm6βgeo/+ 25% Trpm6+/+ | no |
Whole fetus | ♂Trpm6Δ17/+ x ♀Trpm6 Δ17/+ | 25% Trpm6 Δ17/Δ17 50% Trpm6 Δ17/+ 25% Trpm6+/+ | no |
Whole fetus | ♂Trpm6Δ17/+ x ♀Trpm6βgeo/+ | 25% Trpm6βgeo/Δ17 25% Trpm6βgeo/+ 25% Trpm6Δ17/+ 25% Trpm6+/+ | no |
Conditional mutagenesis using Cre/LoxP system | |||
Epiblast | ♂Trpm6Δ17/+;Sox2-Cre x ♀Trpm6fl/fl | 25% Trpm6Δ17/Δ17;Sox2-Cre 25% Trpm6Δ17/fl 25% Trpm6Δ17/+;Sox2-Cre 25% Trpm6fl/+ | yes |
Intestine | ♂Trpm6Δ17/+;Villin1-Cre x ♀Trpm6fl/fl | 25% Trpm6Δ17/fl;Villin1-Cre† 25% Trpm6Δ17/fl 25% Trpm6fl/+;Villin1-Cre 25% Trpm6fl/+ | yes |
Kidney | ♂Trpm6Δ17/+;Ksp-Cre x ♀Trpm6fl/fl | 25% Trpm6Δ17/fl;Ksp-Cre† 25% Trpm6Δ17/fl 25% Trpm6fl/+;Ksp-Cre 25% Trpm6fl/+ | yes |
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*Genotypes were determined using genomic DNA extracted from tail fragments.
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†Individuals were homozygous for Trpm6Δ17 allele in the targeted cells.
Table 2
Dietary regimes used to maintain B6C3F1 mice.
Experimental group | Chow 5 K54 | Drinking water (ad libitum) | Number of mice |
|---|---|---|---|
Control | ad libitum | Regular water* | 335 |
Dietary restriction | 60% of ad libitum | Regular water | 60 |
Magnesium acetate supplemented | ad libitum | 1 g/l Mg(CH3COO)2.(H2O)4 in regular water | 15 |
Magnesium chloride supplemented | ad libitum | 1 g/l MgCl2 in regular water | 15 |
Magnesium hydroxide supplemented | ad libitum | 14 mg/l Mg(OH)2 in regular water† | 15 |
Calcium chloride supplemented | ad libitum | 0.8 g/l CaCl2 in regular water | 15 |
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*Regular water contained 0.44 mg/l Mg2+.
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†Mg(OH)2 concentration was lowered to prevent overall alkalization of the diet.
Additional files
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Supplementary file 1
Whole genome profiling of hepatic transcripts altered in Trpm6-deficient mice.
Dataset is available in the Dryad Digital Repository (Chubanov and Gudermann, 2016). (1) Genome-wide analysis of hepatic transcriptome in control vs Trpm6-deficient mice. (2) Up- and down-regulated transcripts in the liver of Trpm6-deficient mice with the false discovery rate (FDR) p≤0.1.
- https://doi.org/10.7554/eLife.20914.022
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Supplementary file 2
Ingenuity Pathway Analysis (IPA) analysis of hepatic transcripts altered in Trpm6-deficient mice.
Dataset is available from the Dryad Digital Repository (Chubanov and Gudermann, 2016). (1) IPA Canonical Pathways representing differentially expressed genes in the liver of Trpm6-deficient mice. (2) IPA Causal Networks for differentially expressed genes in the liver of Trpm6-deficient mice.
- https://doi.org/10.7554/eLife.20914.023
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Supplementary file 3
Metabolic profiling of the serum, liver and gastrocnemius muscle of Trpm6-deficient mice.
Dataset is available in the Dryad Digital Repository (Chubanov and Gudermann, 2016). (1) Statistical analysis of metabolite measurements in serum samples. (2) Statistical analysis of metabolite measurements in gastrocnemius muscle samples. (3) Statistical analysis of metabolite measurements in liver samples. (4) Metabolites significantly changed in serum samples of Trpm6-deficient mice (FDR p≤0.05). (5) Metabolites significantly changed in gastrocnemius muscle samples of Trpm6-deficient mice (FDR p≤0.05). (6) Metabolites significantly changed in liver samples of Trpm6-deficient mice (FDR p≤0.05). (7) Abbreviations of metabolites.
- https://doi.org/10.7554/eLife.20914.024
