Abstract
Purpose: Mutation of the klotho gene in mice elicits a syndrome resembling accelerated human aging. However, there is limited evidence for the role of Klotho in the kidney. We conducted a comparative proteome analysis of wild-type (WT) and klotho-knockout (kl−/−) mouse kidneys to identify proteins involved in Klotho deficiency. Experimental design: MALDI imaging MS (MALDI-IMS) of frozen kidney sections from 7-wk-old male WT and kl−/− mice was used to determine genotype-specific differences in the MS distribution. Proteins uniquely distributed in kl−/− kidneys were identified by subsequent analysis of adjacent trypsinized sections by MALDI-IMS in combination with LC-MS/MS. Immunohistochemistry and western blotting were adopted in qualitative and quantitation analysis. Results: Ninety-seven and 69 proteins identified by LC-MS/MS were matched to the MALDI-IMS spectra in WT and kl−/− mouse kidneys, respectively. Among protein types matched, nucleic acid binding proteins were most abundant, followed by enzymes. We identified secretogranin-1 (SCG1), which was predominately distributed in the glomeruli and renal tubules of kl−/− mouse kidneys. Immunohistochemistry for SCG1 mirrored images of MALDI-IMS. Conclusions: SCG1 may be a candidate protein involved in Klotho deficiency. Although further research is needed to investigate the role of SCG1 in the kidney, we show the usefulness of MALDI-IMS combined with LC-MS/MS.
Original language | English |
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Article number | 1600095 |
Journal | Proteomics - Clinical Applications |
Volume | 11 |
Issue number | 7-8 |
DOIs | |
Publication status | Published - Jul 2017 |
Keywords
- Kidney
- Klotho
- MALDI-IMS
ASJC Scopus subject areas
- Clinical Biochemistry