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Naas S, Krüger R, Knaup KX, Naas J, Grampp S, Schiffer M, Wiesener M, Schödel J. Hypoxia controls expression of kidney-pathogenic MUC1 variants. Life Sci Alliance 2023; 6:e202302078. [PMID: 37316299 PMCID: PMC10267510 DOI: 10.26508/lsa.202302078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/31/2023] [Accepted: 06/01/2023] [Indexed: 06/16/2023] Open
Abstract
The interplay between genetic and environmental factors influences the course of chronic kidney disease (CKD). In this context, genetic alterations in the kidney disease gene MUC1 (Mucin1) predispose to the development of CKD. These variations comprise the polymorphism rs4072037, which alters splicing of MUC1 mRNA, the length of a region with variable number of tandem repeats (VNTR), and rare autosomal-dominant inherited dominant-negative mutations in or 5' to the VNTR that causes autosomal dominant tubulointerstitial kidney disease (ADTKD-MUC1). As hypoxia plays a pivotal role in states of acute and chronic kidney injury, we explored the effects of hypoxia-inducible transcription factors (HIF) on the expression of MUC1 and its pathogenic variants in isolated primary human renal tubular cells. We defined a HIF-binding DNA regulatory element in the promoter-proximal region of MUC1 from which hypoxia or treatment with HIF stabilizers, which were recently approved for an anti-anemic therapy in CKD patients, increased levels of wild-type MUC1 and the disease-associated variants. Thus, application of these compounds might exert unfavorable effects in patients carrying MUC1 risk variants.
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Affiliation(s)
- Stephanie Naas
- Department of Nephrology and Hypertension, Uniklinikum Erlangen und Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - René Krüger
- Department of Nephrology and Hypertension, Uniklinikum Erlangen und Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Karl Xaver Knaup
- Department of Nephrology and Hypertension, Uniklinikum Erlangen und Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Julia Naas
- Center for Integrative Bioinformatics Vienna (CIBIV), Max Perutz Labs, University of Vienna and Medical University of Vienna, Wien, Austria
| | - Steffen Grampp
- Department of Nephrology and Hypertension, Uniklinikum Erlangen und Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Mario Schiffer
- Department of Nephrology and Hypertension, Uniklinikum Erlangen und Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Michael Wiesener
- Department of Nephrology and Hypertension, Uniklinikum Erlangen und Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Johannes Schödel
- Department of Nephrology and Hypertension, Uniklinikum Erlangen und Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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Bach C, Knaup KX, Herrmann M, Krumbiegel M, Pfister F, Büttner-Herold M, Steffen M, Zecher D, Lopau K, Schneider K, Dieterle A, Amann K, Reis A, Schiffer M, Spriewald BM, Wiesener MS. A noninvasive diagnostic approach to retrospective donor HLA typing in kidney transplant patients using urine. Transpl Int 2021; 34:1226-1238. [PMID: 33904183 DOI: 10.1111/tri.13893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/24/2021] [Accepted: 04/12/2021] [Indexed: 11/29/2022]
Abstract
Antibody-mediated rejection (AMR) is a major obstacle to long-term kidney transplantation. AMR is mostly caused by donor specific HLA antibodies, which can arise before or any time after transplantation. Incomplete donor HLA typing and unavailability of donor DNA regularly preclude the assessment of donor-specificity of circulating anti-HLA antibodies. In our centre, this problem arises in approximately 20% of all post-transplant HLA-antibody assessments. We demonstrate that this diagnostic challenge can be resolved by establishing donor renal tubular cell cultures from recipient´s urine as a source of high-quality donor DNA. DNA was then verified for genetic origin and purity by fluorescence in situ hybridization and short tandem repeat analysis. Two representative cases highlight the diagnostic value of this approach which is corroborated by analysis of ten additional patients. The latter were randomly sampled from routine clinical care patients with available donor DNA as controls. In all 12 cases, we were able to perform full HLA typing of the respective donors confirmed by cross-comparison to results from the stored 10 donor DNAs. We propose that this noninvasive diagnostic approach for HLA typing in kidney transplant patients is valuable to determine donor specificity of HLA antibodies, which is important in clinical assessment of suspected AMR.
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Affiliation(s)
- Christian Bach
- Department of Internal Medicine 5 - Haematology and Oncology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Erlangen, Germany
| | - Karl X Knaup
- Department of Internal Medicine 4 - Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Erlangen, Germany
| | - Markus Herrmann
- Department of Internal Medicine 4 - Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Erlangen, Germany
| | - Mandy Krumbiegel
- Institute of Human Genetics, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Erlangen, Germany
| | - Frederick Pfister
- Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Erlangen, Germany
| | - Maike Büttner-Herold
- Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Erlangen, Germany
| | - Martin Steffen
- Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Erlangen, Germany
| | - Daniel Zecher
- Department of Nephrology, University Hospital Regensburg, Regensburg, Germany
| | - Kai Lopau
- Department of Internal Medicine, University of Würzburg, Würzburg, Germany
| | - Karen Schneider
- Department of Internal Medicine 4 - Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Erlangen, Germany
| | - Anne Dieterle
- Department of Internal Medicine 4 - Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Erlangen, Germany
| | - Kerstin Amann
- Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Erlangen, Germany
| | - André Reis
- Institute of Human Genetics, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Erlangen, Germany
| | - Mario Schiffer
- Department of Internal Medicine 4 - Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Erlangen, Germany
| | - Bernd M Spriewald
- Department of Internal Medicine 5 - Haematology and Oncology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Erlangen, Germany
| | - Michael S Wiesener
- Department of Internal Medicine 4 - Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), University Hospital Erlangen, Erlangen, Germany
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