RNA Profiling in Human and Murine Transplanted Hearts: Identification and Validation of Therapeutic Targets for Acute Cardiac and Renal Allograft Rejection

Abstract

Acute cellular rejection (ACR) is the adverse response of the recipient's immune system against the allogeneic graft. Using human surveillance endomyocardial biopsies (EMBs) manifesting ACR and murine allogeneic grafts, we profiled implicated microRNAs (miRs) and mRNAs. MiR profiling showed that miR‐21, ‐142‐3p, ‐142‐5p, ‐146a, ‐146b, ‐155, ‐222, ‐223, and ‐494 increased during ACR in humans and mice, whereas miR‐149‐5p decreased. mRNA profiling revealed 70 common differentially regulated transcripts, all involved in immune signaling and immune‐related diseases. Interestingly, 33 of 70 transcripts function downstream of IL‐6 and its transcription factor spleen focus forming virus proviral integration oncogene (SPI1), an established target of miR‐155, the most upregulated miR in human EMBs manifesting rejection. In a mouse model of cardiac transplantation, miR‐155 absence and pharmacological inhibition attenuated ACR, demonstrating the causal involvement and therapeutic potential of miRs. Finally, we corroborated our miR signature in acute cellular renal allograft rejection, suggesting a nonorgan specific signature of acute rejection. We concluded that miR and mRNA profiling in human and murine ACR revealed the shared significant dysregulation of immune genes. Inflammatory miRs, for example miR‐155, and transcripts, in particular those related to the IL‐6 pathway, are promising therapeutic targets to prevent acute allograft rejection.

Myocardial micro-biopsy procedure for molecular characterization with increased precision and reduced trauma

“…The usefulness of micro-EMB depends on the concurrent development of molecular diagnostic methods such as transcriptomics, proteomics or other methods that do not require large tissue samples. Important work has already been done in this field regarding transplant rejection, for instance with the development of the MolecularMicroscope 14 , as well as recent explorations of the role of microRNAs in rejection [15][16][17] .…”

“…The aortic and mitral valves were visualized in parasternal and subcostal views. The intervention consisted of 15 (12)(13)(14)(15)(16)(17) micro-biopsies and three conventional biopsies (in the non-safety group only). After intervention, the animals were awoken from anesthesia and housed for seven days, receiving standard post-operative care, and monitored for complications.…”

High-Dimensional Renal Profiling: Towards a Better Understanding of Renal Transplant Immune Suppression

“…Recent advancements in transcriptional and proteomic analysis at the site of rejection has begun to yield critical insights into transplant rejection. Several groups initially began RNA profiling of allografts undergoing rejection using bulk RNA analysis by microarrays and later RNA sequencing methods [71][72][73][74]. Such data have yielded transcripts associated with acute rejection that appear to correlate with rejection severity, the so-called acute rejection transcript set (ARTs) [75].…”

MicroRNAs in heart transplant recipients

“…Было отмечено изменение профиля miR-142-3p не только в плазме и сыворотке реципиента, но и в образцах биопсии при остром клеточном отторжении [33]. Тот факт, что miR-142-3p происходит из иммунных клеток, а не из ткани трансплантата, делает возмож-ным прогнозирование отторжения еще до повреж-дения самого органа [34,35].…”