Noncleavable poly(ADP-ribose) polymerase-1 regulates the inflammation response in mice

Abstract

Poly(ADP-ribosyl)ation is rapidly formed in cells following DNA damage and is regulated by poly(ADPribose) polymerase-1 (PARP-1). PARP-1 is known to be involved in various cellular processes, such as DNA repair, genomic stability, transcription, and cell death. During apoptosis, PARP-1 is cleaved by caspases to generate 89-kDa and 24-kDa fragments, a hallmark of apoptosis. This cleavage is thought to be a regulatory event for cellular death. In order to understand the biological significance of PARP-1 cleavage, we generated a PARP-1 knockin (PARP-1 KI/KI ) mouse model, in which the caspase cleavage site of PARP-1, DEVD 214 , was mutated to render the protein resistant to caspases during apoptosis. While PARP-1 KI/KI mice developed normally, they were highly resistant to endotoxic shock and to intestinal and renal ischemia-reperfusions, which were associated with reduced inflammatory responses in the target tissues and cells due to the compromised production of specific inflammatory mediators. Despite normal binding of NF-κB to DNA, NF-κB-mediated transcription activity was impaired in the presence of caspase-resistant PARP-1. This study provides a novel insight into the function of PARP-1 in inflammation and ischemia-related pathophysiologies. IntroductionUpon DNA damage, poly(ADP-ribose) polymerase-1 (PARP-1, EC 2.4.2.30) is activated and catalyzes the formation of poly(ADPribose) (PAR) chains by transferring (ADP-ribose) from β-NAD + onto itself and nuclear acceptor proteins (1). PARP-1 is known to be involved in various cellular processes including DNA repair, recombination, genomic stability, transcription regulation, and cell death (1-3). In addition, massive poly(ADP-ribosyl)ation induced by acute DNA damage results in rapid depletion of cellular NAD + and ATP pools, which, if not regulated, can lead to cellular dysfunction and cell death (4). Involvement of PARP-1 in cell death is also speculated based on the prominent phenomenon that during apoptosis, PARP-1 is cleaved by caspases at the conserved site DEVD 214 , generating 24-kDa and 89-kDa fragments, a hallmark of apoptosis.Mice lacking PARP-1 develop normally and PARP-1 -/-fibroblasts and lymphoid cells display a normal apoptotic response after treatment with various apoptotic inducers, such as anti-Fas antibody, TNF-α, γ-radiation, and dexamethasone, which demonstrates that PARP-1 per se is dispensable for apoptosis, at least in these cell types (5, 6). However, inactivation of PARP-1 by chemical inhibitors and genetic means protects mice from endotoxic shock and other disease models related to inflammation, such as diabetes, stroke, and myocardial reperfusion (7-12). In addition, PARP inhibitors protect rats from renal and intestinal ischemia-

Suppression of matrix metalloproteinase-9 expression in undifferentiated, non-apoptotic keratinocytes is abrogated by the cleavage of poly(ADP-ribose) polymerase-1

“…I suggest that because of the following considerations: First, because we reported the localization of MMP-9 in many types of abnormal keratinization in pathological conditions of the skin [30,59,60]; second, because MMP-9 null mice reportedly have a low level of differentiation of keratinocytes not in normal conditions but in squamous cell carcinomas [22]; and third, because the expression of MMP-9 as an inducible protein often accompanies inflammatory conditions [19, 21, 23, 34-36, 61, 62]. Concerning the third case, the mechanism of MMP-9 induction by PARP-1 and caspases could work in many inflammatory conditions in which MMP-9 is involved, since the reduced inflammation of noncleavable PARP-1 in mice has also been shown [13].…”

“…Recently, the events involved in apoptosis have been unveiled in much detail and caspases and poly(ADP-ribose) polymerase-1 (PARP-1) play important roles during that process [12]. Caspase activities involved with PARP-1 are also reportedly involved with inflammation [13].…”

An Overview of Pathways of Regulated Necrosis in Acute Kidney Injury

“…107 Interestingly, the PARP-1 enzymatic activity appears dispensable for an NF-κB-mediated inflammatory response in the kidney because Parp1 -/-mice reconstituted with enzyme-dead PARP-1 restored the inflammatory response whereas Parp1 ki/ki that were engineered to have a point mutation specifically at the caspase cleaving site, making them resistant to caspasedependent apoptotic cleavage, did not. 108,109 OʼValle et al 110 investigated PARP-1 expression in renal transplant recipients that developed acute tubular necrosis after transplantation. By immunohistochemistry, they observed PARP-1 up-regulation in epithelial cells, but also on peritubular and glomerular capillaries during acute tubular necrosis.…”

Application of pulsed-magnetic field enhances non-viral gene delivery in primary cells from different origins

“…Primary mouse peritoneal macrophage was isolated from 129Sv/Ev/J mice as previously described [58,59] while mouse embryonic fibroblasts (MEFs) were isolated according to standard procedures described previously [57,58].…”