α-Klotho Expression in Human Tissues.

{"sci_version": "1.2", "schema": "https://corpus.bntrg.co.uk/sci/1.0/sci.schema.json", "id": "pmid:26280509", "kind": "science-record", "revision": 5, "content_hash": "sha256:257daded979aaa745b808f23a5166ef3ea82167ff5b524a6911be7b80c7797eb", "created_at": "2026-11-01T15:40:10Z", "updated_at": "2026-11-01T18:47:29Z", "generator": {"name": "corpus-assay-engine", "run_id": "reading-sci-2026-11-01"}, "paper": {"state": "complete", "title": "α-Klotho Expression in Human Tissues.", "doi": "10.1210/jc.2015-1800", "pmid": "26280509", "authors": ["Kenneth Lim", "Arnoud Groen", "Guerman Molostvov", "Tzongshi Lu", "Kathryn S Lilley", "David Snead", "Sean James", "Ian B Wilkinson", "Stephen Ting", "Li-Li Hsiao", "Thomas F Hiemstra", "Daniel Zehnder"], "journal": "The Journal of clinical endocrinology and metabolism", "year": 2015, "abstract": "CONTEXT: α-Klotho has emerged as a powerful regulator of the aging process. To date, the expression profile of α-Klotho in human tissues is unknown, and its existence in some human tissue types is subject to much controversy.\nOBJECTIVE: This is the first study to characterize systemwide tissue expression of transmembrane α-Klotho in humans. We have employed next-generation targeted proteomic analysis using parallel reaction monitoring in parallel with conventional antibody-based methods to determine the expression and spatial distribution of human α-Klotho expression in health.\nRESULTS: The distribution of α-Klotho in human tissues from various organ systems, including arterial, epithelial, endocrine, reproductive, and neuronal tissues, was first identified by immunohistochemistry. Kidney tissues showed strong α-Klotho expression, whereas liver did not reveal a detectable signal. These results were next confirmed by Western blotting of both whole tissues and primary cells. To validate our antibody-based results, α-Klotho-expressing tissues were subjected to parallel reaction monitoring mass spectrometry (data deposited at ProteomeXchange, PXD002775) identifying peptides specific for the full-length, transmembrane α-Klotho isoform.\nCONCLUSIONS: The data presented confirm α-Klotho expression in the kidney tubule and in the artery and provide evidence of α-Klotho expression across organ systems and cell types that has not previously been described in humans.", "claims": [{"id": "claim-data-access", "statement": "All proteomic data have been deposited with the ProteomeXchange consortium open access repository and can be accessed at http://proteomecentral.proteomexchange.org (identifier PXD002775).", "kind": "methodological", "target": null, "evidence": [{"asset": "source:pmid:26280509", "locator": "sections[22] \"Mass spectrometry analysis of human samples\" paragraph 7", "quote": "All proteomic data have been deposited with the ProteomeXchange consortium open access repository and can be accessed at http://proteomecentral.proteomexchange.org (identifier PXD002775)."}], "state": "complete"}, {"id": "claim-target-result", "statement": "No numerical result for the statistical method is stated; the headline result is: “The data presented confirm α-Klotho expression in the kidney tubule and in the artery and provide evidence of α-Klotho expression across organ systems and cell types that has not previously been described in humans.”", "kind": "qualitative", "target": null, "evidence": [{"asset": "source:pmid:26280509", "locator": "sections[0] \"Abstract\" paragraph 4", "quote": "The data presented confirm α-Klotho expression in the kidney tubule and in the artery and provide evidence of α-Klotho expression across organ systems and cell types that has not previously been described in humans."}, {"asset": "source:pmid:26280509", "locator": "sections[0] \"Abstract\" paragraph 3", "quote": "To validate our antibody-based results, α-Klotho-expressing tissues were subjected to parallel reaction monitoring mass spectrometry (data deposited at ProteomeXchange, PXD002775) identifying peptides specific for the full-length, transmembrane α-Klotho isoform."}], "state": "complete"}], "gaps": []}, "experiment": {"state": "complete", "objective": "No numerical result for the statistical method is stated; the headline result is: “The data presented confirm α-Klotho expression in the kidney tubule and in the artery and provide evidence of α-Klotho expression across organ systems and cell types that has not previously been described in humans.”", "steps": [{"id": "read_published_estimate", "order": 1, "name": "Read the published estimate from the source", "kind": "other", "state": "complete", "blocked_on": null, "description": "The claim, method and evidence span published with the source article.", "duration_hours": null, "parameters": {}, "inputs": ["source:pmid:26280509"], "outputs": ["the published estimate and its evidence"], "instruments": [], "reagents": []}, {"id": "obtain_source_data", "order": 2, "name": "Obtain the source data from the named repository", "kind": "data-preparation", "state": "complete", "blocked_on": null, "description": "The GEO series accession resolves and its sample accessions are listed. 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Kidney tissues showed strong α-Klotho expre", "g no. SC-6110; ScienCell). Human tissues for immunohistochemistry (IHC) and tissue lysate preparation were obt", "ll). Human tissues for immunohistochemistry (IHC) and tissue lysate preparation were obtained", "for those tissues where it was identified by IHC experiments, we next performed Western blott"], "order_basis": "paper_text_order:764", "id": "assay:1"}, {"role": "data_generation", "definition_id": "western_blot", "definition_version": "99e1195c7d6f", "definition_digest": null, "required_operations": [], "support_state": "partial", "source_hashes": {"assay_lexicon": "99e1195c7d6f"}, "confidence": 0.99, "evidence": ["signal. These results were next confirmed by Western blotting of both whole tissues and primary cells. To", "database. Analysis of α-Klotho expression by Western blotting To confirm the presence and molecular weight", "tified by IHC experiments, we next performed Western blotting on both human tissue lysates and (where avai", "gth rh-α-Klotho protein as positive control. Western blotting demonstrated the presence of full-length (11"], "order_basis": "paper_text_order:923", "id": "assay:2"}, {"role": "data_generation", "definition_id": "mass_spectrometry", "definition_version": "99e1195c7d6f", "definition_digest": null, "required_operations": [], "support_state": "partial", "source_hashes": {"assay_lexicon": "99e1195c7d6f"}, "confidence": 0.99, "evidence": ["re subjected to parallel reaction monitoring mass spectrometry (data deposited at ProteomeXchange, PXD00277", "catalog no. ab29792). Sample preparation for mass spectrometry All protein samples (50 μg) were fractionate", "hromatography-electrospray ionization tandem mass spectrometry (MS/MS) and PRM analysis in an Orbitrap nano", "ex, spinal cord, and cerebellum (Figure 1D). Mass spectrometry analysis of human samples The data described"], "order_basis": "paper_text_order:1096", "id": "assay:3"}, {"role": "data_generation", "definition_id": "cell_culture", "definition_version": "99e1195c7d6f", "definition_digest": null, "required_operations": [], "support_state": "partial", "source_hashes": {"assay_lexicon": "99e1195c7d6f"}, "confidence": 0.77, "evidence": ["e HNL, catalog no. 1526). Human hepatocytes (HepG2; Sigma) were kindly gifted by Dr. Graeme Ale"], "order_basis": "paper_text_order:2068", "id": "assay:4"}]}