Related Experiment Video
Updated: Apr 8, 2026
Isolation and Identification of Vascular Endothelial Cells from Distinct Adipose Depots for Downstream Applications
Published on: June 10, 2022
Membrane-bound Klotho is not expressed endogenously in healthy or uraemic human vascular tissue
Rik Mencke1, Geert Harms1, Katarina Mirković2
1Department of Pathology and Medical Biology (Division of Pathology), University of Groningen, University Medical Center Groningen, HPC EA10, PO Box 30.001, Groningen 9700 RB, The Netherlands.
Insights
Full-length Klotho is not found in human blood vessel walls, despite its known role in kidney disease. This study used validated methods to investigate Klotho expression in vascular tissues.
Area of Science:
- Vascular Biology
- Nephrology
- Cardiovascular Disease
Background:
- Cardiovascular disease (CVD) is a major cause of mortality in chronic kidney disease (CKD) patients.
- Loss of alpha-Klotho is linked to CKD and medial calcification, suggesting a vasculoprotective role for Klotho.
- Klotho expression within the vessel wall remains a debated topic.
Purpose of the Study:
- To investigate the presence and expression of full-length Klotho in human vascular tissues.
- To determine if Klotho plays a role in the vasculature of patients with and without CKD.
Main Methods:
- Immunohistochemistry (IHC), immunofluorescence, quantitative RT-PCR, and Western blotting (WB) were employed.
- Extensive validation of anti-Klotho antibody KM2076 was performed.
- Analysis included healthy human renal arteries, CKD arteries, carotid endarterectomy specimens, and cultured human aortic smooth muscle cells.
Main Results:
- Full-length Klotho was not detected in any healthy or CKD human vascular tissues or cultured smooth muscle cells using validated antibodies.
- Klotho mRNA expression was also undetectable in these vascular samples.
- FGF23 signaling, dependent on Klotho, was absent in the aorta of mice, unlike in the kidneys.
Conclusions:
- Full-length, membrane-bound Klotho is not expressed in healthy or uraemic human vascular tissue.
- The proposed vasculoprotective role of Klotho in the vessel wall may not be mediated by direct Klotho expression in vascular cells.
Aims:
Cardiovascular disease (CVD) is the leading cause of death in patients with chronic kidney disease (CKD), a disease state that is strongly associated with loss of renal and systemic (alpha-)Klotho. Reversely, murine Klotho deficiency causes marked medial calcification. It is therefore thought that Klotho conveys a vasculoprotective effect. Klotho expression in the vessel wall, however, is disputed.
Methods And Results:
We assessed Klotho expression in healthy human renal donor arteries (n = 9), CKD (renal graft recipient) arteries (n = 10), carotid endarterectomy specimens (n = 8), other elastic arteries (three groups of n = 3), and cultured human aortic smooth muscle cells (HASMCs) (three primary cell lines), using immunohistochemistry (IHC), immunofluorescence, quantitative reverse transcriptase-polymerase chain reaction, and western blotting (WB). We have extensively validated anti-Klotho antibody KM2076 by comparing staining patterns with other anti-Klotho antibodies (SC-22220, SC-22218, and AF1819), competition assays with recombinant Klotho, IHC on Klotho-deficient kl/kl mouse kidney, and WB with recombinant Klotho. Using KM2076, we could not detect full-length Klotho in vascular tissues or HASMCs. On the mRNA level, using primers against all four exon junctions, klotho expression could not be detected either. Fibroblast growth factor 23 (FGF23) injections in mice induced FGF23 signalling in kidneys but not in the aorta, indicating the absence of Klotho-dependent FGF23 signalling in the aorta.
Conclusion:
Using several independent and validated methods, we conclude that full-length, membrane-bound Klotho is not expressed in healthy or uraemic human vascular tissue.
More Related Videos
08:43Calcification of Vascular Smooth Muscle Cells and Imaging of Aortic Calcification and Inflammation
Published on: May 31, 2016
08:41Assessment of Vascular Tone Responsiveness using Isolated Mesenteric Arteries with a Focus on Modulation by Perivascular Adipose Tissues
Published on: June 3, 2019
Related Concept Videos
01:20Overview of the Vascular System
01:24Regulation of Angiogenesis and Blood Supply
01:27Tissue Membranes
Connective Tissue Membranes
The connective tissue membrane is formed solely from connective tissue. These membranes encapsulate organs, such as the kidneys, and line our movable joints. A synovial...
01:27Regulation of the Cardiovascular System
The regulation of the cardiovascular system involves the autonomic nervous system (ANS), baroreceptors, and chemoreceptors, ensuring that heart rate and blood pressure are appropriately modulated in response to varying physiological demands.
The ANS comprises two main divisions: the sympathetic and parasympathetic nervous systems. The sympathetic nervous system enhances...
01:20Extrinsic and Intrinsic Pathways of Hemostasis
The Extrinsic Pathway
The extrinsic pathway of coagulation is typically initiated by tissue damage that exposes blood to tissue factor (TF), a protein released by the damaged tissue cells outside the blood vessels—this interaction with TF triggers biochemical reactions involving specific clotting factors. The key player here is Factor VII, which...
01:20Vascular Resistance
The primary determinants of vascular resistance are vessel diameter, blood viscosity, and vessel length. Among these, vessel diameter plays the most significant role due to the fourth power relationship described by...