Mitochondrial Feedback Mechanisms in Kidney Cell Senescence
1Department of Nephrology and Renal Transplantation, University Hospitals Leuven, Leuven, Belgium
2Centre for Environmental Sciences, Hasselt University, Hasselt, Belgium
3Department of Pathology, University Hospitals Leuven, Leuven, Belgium.
Meeting: 2015 American Transplant Congress
Abstract number: B96
Keywords: Age factors, Biopsy, Graft function, Kidney transplantation
Session Information
Session Name: Poster Session B: Kidney Complications: Late Graft Failure
Session Type: Poster Session
Date: Sunday, May 3, 2015
Session Time: 5:30pm-6:30pm
Presentation Time: 5:30pm-6:30pm
Location: Exhibit Hall E
Background
Progressive DNA damage (telomere attrition) is considered one of the key instigators of ageing. Different models for ageing where DNA damage leads to accelerated senescence have been proposed.
Methods
A test cohort of 40 consecutive kidney donors, with pre-implantation renal allograft biopsies, was included in this study. All biopsies were rescored according to the Banff classification. Intrarenal and donor leucocyte telomere length, and mitochondrial DNA content was assessed using quantitative RT-PCR. In these same samples (N=40), whole genome microarray mRNA expression analysis was performed using Affymetrix Gene 2.0 ST arrays (N=40). The associations between mRNA gene expression and the biomarkers of replicative senescence were investigated using multiple regression models, adjusted for calendar age, gender and batch number. For biological interpretation, Ingenuity Pathway Analysis and Consensus software were used to identify overrepresented pathways. An independent cohort of 160 implantation biopsies was used for validation.
Results
In total, 1180 transcripts significantly associated with intrarenal telomere length, of which 611 were significantly upregulated with shorter telomeres. Pathway analysis revealed enrichment of transcripts coding for proteins of the citric acid cycle (q=1.06×10-13), transcripts involved in respiratory electron transport (q=1.06×10-13) and transcripts involved in oxidative phosphorylation (q=4.48×0-10). Also mitochondrial DNA content correlated highly significantly with telomere length (r= 0.3; p=0.0005). Independent replication of these findings is on-going on a separate cohort of 160 pre-implantation biopsies.
Conclusion
This unbiased study suggests that mitochondrial alterations (DNA content and mitochondrial gene expression) are key features of replicative senescence of human kidneys. Upregulation of mitochondrial gene expression in baseline kidneys for transplantation is a protective feedback mechanism and a potential therapeutic target for improving renal allograft viability in the perioperative phase.
To cite this abstract in AMA style:
Vusser KDe, Hochstenbach K, Winckelmans E, Lerut E, Kuypers D, Nawrot T, Naesens M. Mitochondrial Feedback Mechanisms in Kidney Cell Senescence [abstract]. Am J Transplant. 2015; 15 (suppl 3). https://atcmeetingabstracts.com/abstract/mitochondrial-feedback-mechanisms-in-kidney-cell-senescence/. Accessed September 7, 2024.« Back to 2015 American Transplant Congress