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Gene expression profiling of prolonged cold ischemia and reperfusion in murine heart transplants
Albert Amberger1, Stefan Schneeberger, Gerald Hernegger
1D. Swarovski Research Laboratory, Department of Transplant Surgery, University Hospital Innsbruck, Austria. albert.amberger@uklibk.ac.at.
Background:
Heart transplantation causes complex changes in the biological homeostasis of the graft. Current knowledge is restricted to a few genes and regulation of certain factors involved in ischemia-reperfusion (I/R) injury. Efficient strategies to prevent I/R injury, however, require a better understanding of its mechanisms. Using cDNA microarrays, we investigated gene expression profiles of murine cardiac isografts.
Methods:
For microarray hybridization experiments, chips with 8,734 individual target sequences were used. Messenger RNA was extracted from hearts subjected to warm ischemia and different time periods of reperfusion or to prolonged cold ischemia or warm ischemia and transplantation. Native hearts served as controls.
Results:
A set of 68 sequences was regulated in all hearts. In addition, grafts without cold ischemia showed differential expression of 65 sequences, which were not found in hearts transplanted after cold storage, and which in turn had 38 sequences regulated and not detected in grafts without cold ischemia. Overall, approximately 50% of regulated transcripts are expressed sequence tags (ESTs) with unknown function. Annotated genes encoded immune modulators (20% of sequences), receptor proteins, structural proteins, and proteins involved in metabolism.
Conclusion:
Our data demonstrate expression profiles of hearts subjected to prolonged cold ischemia or transplantation in an isogeneic setting. We have defined functional complexes and detected a substantial amount of ESTs encoding novel proteins. These studies may provide a molecular basis for further functional experiments and may help identify potential targets for modulation of postischemic inflammation.
Insights
This study reveals gene expression changes in transplanted mouse hearts, identifying key genes involved in ischemia-reperfusion injury and immune response. Understanding these molecular profiles aids in developing strategies to prevent transplant complications.
Area of Science:
- Cardiovascular Biology
- Transplantation Immunology
- Molecular Biology
Background:
- Heart transplantation significantly disrupts graft homeostasis.
- Knowledge of ischemia-reperfusion (I/R) injury mechanisms is limited, hindering prevention strategies.
- Investigating gene expression profiles is crucial for understanding I/R injury in cardiac grafts.
Purpose of the Study:
- To investigate comprehensive gene expression profiles in murine cardiac isografts.
- To identify genes regulated during ischemia-reperfusion and transplantation.
- To understand molecular mechanisms underlying post-transplant graft injury.
Main Methods:
- Utilized cDNA microarrays with 8,734 target sequences for gene expression analysis.
- Extracted messenger RNA from cardiac grafts subjected to various ischemia and reperfusion conditions.
- Employed native hearts as controls for comparative analysis.
Main Results:
- Identified 68 consistently regulated sequences across all studied hearts.
- Discovered distinct sets of differentially expressed genes (65 and 38 sequences) related to cold ischemia duration.
- Found approximately 50% of regulated transcripts were expressed sequence tags (ESTs) of unknown function, alongside immune modulators and metabolic proteins.
Conclusions:
- Established gene expression profiles for isogeneic cardiac grafts under prolonged cold ischemia and transplantation.
- Defined functional gene complexes and identified numerous novel protein-encoding ESTs.
- Provided a molecular foundation for future research into post-ischemic inflammation modulation in heart transplantation.