Dataset Information

Panhematin provides a therapeutic benefit in experimental pancreatitis.

ABSTRACT: Acute pancreatitis (AP) can result in pancreatic necrosis and inflammation, with subsequent multi-organ failure. AP is associated with increased neutrophil recruitment and a rise in pro-inflammatory cytokines such as TNF?. Pretreatment with haemin, results in recruitment of haem-oxygenase-1 (HO-1)(+) macrophages and protects against experimental pancreatitis. It is not clear whether modulation of HO-1 after onset of disease has a protective role. In this study, we tested the utility of Panhematin, a water-soluble haemin formulation, in activating and inducing pancreatic HO-1, and as a therapeutic agent in treating mouse acute pancreatitis.We defined the distribution of radiolabelled haemin, then used in vivo HO-1-luciferase bioluminescence imaging and the CO-release assay to test Panhematin-induced upregulation of HO-1 transcription and activity, respectively. Using two well-defined AP murine models, we tested the therapeutic benefit of Panhematin, and quantified cytokine release using a luminex assay.Intravenously administered Panhematin induces rapid recruitment of HO-1(+) cells to the pancreas within 2 h and de novo splenic HO-1 transcription by 12 h. Despite high baseline spleen HO-1 activity, the pancreas is particularly responsive to Panhematin-mediated HO-1 induction. Panhematin-treated mice, at various time points after AP induction had significant reduction in mortality, pancreatic injury, together with upregulation of HO-1 and downregulation of pro-inflammatory cytokines and CXCL1, a potent neutrophil chemoattractant.Despite AP-associated mortality and morbidity, no effective treatment other than supportive care exists. We demonstrate that Panhematin leads to: (i) rapid induction and activation of pancreatic HO-1 with recruitment of HO-1(+) cells to the pancreas, (ii) amelioration of AP even when given late during the course of disease, and (iii) a decrease in leucocyte infiltration and pro-inflammatory cytokines including CXCL1. The utility of Panhematin at modest doses as a therapeutic in experimental pancreatitis, coupled with its current use and safety in humans, raises the potential of its applicability to human pancreatitis.

SUBMITTER: Habtezion A

PROVIDER: S-EPMC3580958 | biostudies-literature | 2011 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Panhematin provides a therapeutic benefit in experimental pancreatitis.

Habtezion Aida A Kwan Raymond R Akhtar Ehsaan E Wanaski Stephen P SP Collins Stephen D SD Wong Ronald J RJ Stevenson David K DK Butcher Eugene C EC Omary M Bishr MB

Gut 20101215 5

<h4>Background and aim</h4>Acute pancreatitis (AP) can result in pancreatic necrosis and inflammation, with subsequent multi-organ failure. AP is associated with increased neutrophil recruitment and a rise in pro-inflammatory cytokines such as TNFα. Pretreatment with haemin, results in recruitment of haem-oxygenase-1 (HO-1)(+) macrophages and protects against experimental pancreatitis. It is not clear whether modulation of HO-1 after onset of disease has a protective role. In this study, we test ...[more]

PMID: 21159893

Similar Datasets

Project description:Therapeutic strategies that enhance anti-viral immunity and reduce the viral reservoir are critical to achieving durable remission of HIV. The co-inhibitory receptor programmed death-1 (PD-1) regulates CD8+ T cell dysfunction during chronic HIV and SIV infections 1-4. In addition, PD-1+ CD4+ T cells constitute a significant fraction of the HIV/SIV viral reservoir5-7. We previously demonstrated that in vivo blockade of PD-1 during chronic SIV infection improves the function of anti-viral CD8+ T cells and B cells 4,8. However, the immunological effects of PD-1 blockade during anti-retroviral therapy (ART) and the potential to destabilize the persistent HIV/SIV reservoir have not been studied. Here, we show that administration of anti-PD-1 antibody (PD-1 Ab) 10 days prior to initiation of ART rapidly enhanced anti-viral CD8+ T cell function and diminished interferon stimulated genes (ISGs) that resulted in markedly improved viral suppression in plasma and better Th17 cell reconstitution in the rectal mucosa following ART initiation. In addition, PD-1 blockade during suppressive ART resulted in transient increases in plasma viremia, induction of gene signatures associated with effector CD8+ T cell function and ISGs, and lower levels of cell associated replication-competent virus suggesting destabilization of the viral reservoir. Following ART interruption, PD-1 Ab treated animals showed markedly higher expansion of proliferating CXCR5+ Perforin+ Granzyme B+ effector CD8+ T cells and lower regulatory T cells that resulted in delayed viral rebound and better control of viremia. PD-1 blockade administered only during suppressive ART however was only partially effective. Our results indicate an optimal regimen of PD-1 blockade administered in combination with ART, that augments anti-viral CD8+ T cell function and reduces the viral reservoir leading to improved control of viral rebound after ART interruption. These results have important implications for developing novel therapeutic interventions to achieve durable remission of HIV.

Project description:Pelizaeus-Merzbacher-like disease or hypomyelinating leukodystrophy-2 is an autosomal recessively inherited leukodystrophy with childhood onset resulting from mutations in the gene encoding the gap junction protein connexin 47 (Cx47, encoded by GJC2). Cx47 is expressed specifically in oligodendrocytes and is crucial for gap junctional communication throughout the central nervous system. Previous studies confirmed that a cell autonomous loss-of-function mechanism underlies hypomyelinating leukodystrophy-2 and that transgenic oligodendrocyte-specific expression of another connexin, Cx32 (GJB1), can restore gap junctions in oligodendrocytes to achieve correction of the pathology in a disease model. To develop an oligodendrocyte-targeted gene therapy, we cloned the GJC2/Cx47 gene under the myelin basic protein promoter and used an adeno-associated viral vector (AAV.MBP.Cx47myc) to deliver the gene to postnatal Day 10 mice via a single intracerebral injection in the internal capsule area. Lasting Cx47 expression specifically in oligodendrocytes was detected in Cx47 single knockout and Cx32/Cx47 double knockout mice up to 12 weeks post-injection, including the corpus callosum and the internal capsule but also in more distant areas of the cerebrum and in the spinal cord. Application of this oligodendrocyte-targeted somatic gene therapy at postnatal Day 10 in groups of double knockout mice, a well characterized model of hypomyelinating leukodystrophy-2, resulted in significant improvement in motor performance and coordination at 1 month of age in treated compared to mock-treated mice, as well as prolonged survival. Furthermore, immunofluorescence and morphological analysis revealed improvement in demyelination, oligodendrocyte apoptosis, inflammation, and astrogliosis, all typical features of this leukodystrophy model in both brain and spinal cord. Functional dye transfer analysis confirmed the re-establishment of oligodendrocyte gap junctional connectivity in treated as opposed to untreated mice. These results provide a significant advance in the development of oligodendrocyte-cell specific gene therapy. Adeno-associated viral vectors can be used to target therapeutic expression of a myelin gene to oligodendrocytes. We show evidence for the first somatic gene therapy approach to treat hypomyelinating leukodystrophy-2 preclinically, providing a potential treatment for this and similar forms of leukodystrophies.

Dataset Information

Panhematin provides a therapeutic benefit in experimental pancreatitis.

Publications

Panhematin provides a therapeutic benefit in experimental pancreatitis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets