Transgenic Overexpression of CD39 Protects Against Renal Ischemia-Reperfusion and Transplant Vascular Injury

Abstract

The vascular ectonucleotidases CD39 [ENTPD1 (ec-tonucleoside triphosphate diphosphohydrolase-1), EC 3.6.1.5] and CD73 [EC 3.1.3.5] generate adenosine from extracellular nucleotides. CD39 activity is critical in determining the response to ischemia-reperfusion injury (IRI), and CD39 null mice exhibit heightened sensitivity to renal IRI. Adenosine has multiple mechanisms of action in the vasculature including direct endothelial protection, antiinflammatory and antithrombotic effects and is protective in several models of IRI. Mice transgenic for human CD39 (hCD39) have increased capacity to generate adenosine. We therefore hypothesized that hCD39 transgenic mice would be protected from renal IRI. The overexpression of hCD39 conferred protection in a model of warm renal IRI, with reduced histological injury, less apoptosis and preserved serum creatinine and urea levels. Benefit was abrogated by pretreatment with an adenosine A2A receptor antagonist. Adoptive transfer experiments showed that expression of hCD39 on either the vasculature or circulating cells mitigated IRI. Furthermore, hCD39 transgenic kidneys transplanted into syngeneic recipients after prolonged cold storage performed significantly better and exhibited less histological injury than wild-type control grafts. Thus, systemic or local strategies to promote adenosine generation and signaling may have beneficial effects on warm and cold renal IRI, with implications for therapeutic application in clinical renal transplantation.

CD39 overexpression does not attenuate renal fibrosis in the unilateral ureteric obstructive model of chronic kidney disease

“…The human CD39 transgene (hCD39) is under the control of the mouse H-2Kb promoter, which promotes expression on all nucleated cells. The level of CD39 overexpression is increased on circulating cells (as demonstrated by flow cytometry) [4,14] and in solid organs (as demonstrated by immunohistochemistry) such as the heart [4], lung [4], liver [15], pancreatic islets [16], and kidneys, especially on the vasculature [17]. CD39Tg mice have the same phenotype as WT littermates and have similar body weights and breeding patterns [4].…”

“…Data are described as mean ± SEM, n = 4 (***P < 0.001 vs. WT baseline; ###P < 0.001 vs. CD39Tg baseline) (TNAP), an ecto-nucleotidase present in the kidney [24], can generate adenosine from AMP in addition to CD73 [25]. It is difficult to fully elucidate that the contribution of the CD39 transgene expression to adenosine generation as the overexpression of CD39 is predominantly on the renal vasculature [17]. Whole kidney measurements of nucleotide and adenosine content in the kidneys following UUO will not be able to accurately quantify the isolated increase in adenosine level in the vascular compartment compared to the whole kidney.…”

Central Role of CD45RA− Foxp3hi Memory Regulatory T Cells in Clinical Kidney Transplantation Tolerance

“…This result is consistent with the growing body of evidence that demonstrates the role of CD39 in immunologic tolerance 46 and in control of inflammation and graft rejection. 47,48 Indeed, CD39 + Tregs have been demonstrated to catalyze the cleavage of ATP to AMP, which is then further cleaved to adenosine, leading to the control of T cell activation. 49 In combination with our findings, these data suggest a potential role for CD39 + Tregs in transplantation tolerance.…”

Development of a novel strategy to target CD39 antithrombotic activity to the endothelial-platelet microenvironment in kidney ischemia–reperfusion injury

“…IRI leads to inflammation, kidney dysfunction, and increases graft immunogenicity and rejection. We and others have accumulated a wealth of evidence detailing the role of purinergic signalling in IRI, and strategies targeting pathways involved in purinergic signalling have shown promising results both in vitro and in vivo [1][2][3][4][5].…”

“…Adenosine-mediated signalling is protective in kidney IRI. CD39 overexpression protects from renal IRI via an adenosine-dependent mechanism, and CD39 −/− mice exhibit more severe renal histopathology and dysfunction than wildtype mice [1,2]. In the kidney, adenosine controls renin release, renal vascular tone and the rate of glomerular filtration.…”