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May-June 2010 l Vol 16 l No 5-6

Research Articles

Human Neutrophil Elastase-Mediated Cleavage Sites of MMP-9 and TIMP-1: Implications to Cystic Fibrosis Proteolytic Dysfunction
Patricia L Jackson, Xin Xu, Landon Wilson, Nathaniel M Weathington, John Paul Clancy, James Edwin Blalock, and Amit Gaggar
Cystic fibrosis (CF) is a lethal genetic disorder characterized by airway remodeling and inflammation, leading to premature death. Recent evidence suggests the importance of protease activity in CF pathogenesis. One protease, matrix metalloprotease 9 (MMP-9), demonstrates increased activity in CF patients undergoing acute pulmonary exacerbation. This may be due to increased MMP-9 activation as well as degradation of MMP-9’s natural inhibitor, tissue inhibitor of metalloprotease-1 (TIMP-1). To examine whether this relationship exists in nonexacerbating CF patients, Jackson et al. examined protease activity in nonexacerbating CF patients and controls. Results demonstrate increased MMP-9 activity is stable in CF lung disease, and the presence of specific protease products in CF sputum highlights that human neutrophil elastase-mediated activity plays a role in this dysregulation. This data may have implications for disease-specific therapeutics.
Page 159 l View article: PDF (3.8 MB)

Factor VII Deficiency Impairs Cutaneous Wound Healing in Mice
Zhi Xu, Haifeng Xu, Victoria A Ploplis, and Francis J Castellino
Injury to the skin initiates a dynamic process of wound healing characterized by an inflammatory phase, a proliferative phase and a final remodeling process that removes the cells no longer required. Skin keratinocytes express Tissue Factor (TF), a protein associated with skin wound healing, but little is known in this regard about Factor (F) VII, a TF ligand. Xu et al. employed a dermal punch model to demonstrate that low-expressing FVII mice exhibited impaired skin wound healing. This manifested as defective re-epithelialization and reduced inflammatory cell infiltration at wound sites associated with diminished expression of the transcription factor, early growth response-1 (Egr-1). The authors demonstrate an in vivo relationship between FVIIa, Egr-1 and the inflammatory response in keratinocyte function during the wound healing process. Greater insight into the mechanism of wound healing holds implications that stretch from the surgical suite to the battlefield.
Page 167 l View article: PDF (3.9 MB)

Interferon γ–Induced Human Guanylate Binding Protein 1 Inhibits Mammary Tumor Growth in Mice
Karoline Lipnik, Elisabeth Naschberger, Nathalie Gonin-Laurent, Petra Kodajova, Helga Petznek, Stefanie Rungaldier, Simonetta Astigiano, Silvano Ferrini, Michael Stürzl, and Christine Hohenadl
Cancer can develop when the immune system does not properly identify and target abnormal cells for destruction. Recently, interferon gamma (IFN-γ) and its effectors, like guanylate binding proteins (GBPs), have been implicated in cancer immunosurveillance. Lipnik et al. therefore investigated whether one well-known human GBP, GBP-1 (hGBP-1), may contribute to IFN-γ–mediated tumor defense in syngeneic immune competent BALB/c mice. The authors found that animals induced to express greater quantities of hGBP-1 exhibited reduced tumor growth, lower levels of tumor tissue hemoglobin contents and attenuated tumor cell proliferation. Furthermore, these results corresponded to reduced amounts of VEGF-A both in vitro and in vivo. The authors conclude that these observations implicate hGBP-1 in IFN-γ–mediated antitumorigenic activities through inhibition of tumor cell angiogenesis. Increased understanding of how the immune system recognizes and disposes of neoplastic cells could yield innovative treatments for a variety of malignant cancers.
Page 177 l View article: PDF (9 MB)

Substance P in Polymicrobial Sepsis: Molecular Fingerprint of Lung Injury in Preprotachykinin-A^–/– Mice
Akhil Hegde, Ramasamy Tamizhselvi, Jayapal Manikandan, Alirio J Melendez, Shabbir M Moochhala, and Madhav Bhatia
Sepsis can be caused be an imbalance in the body’s immune response to overwhelming bacterial infection. Deletion of mouse preprotachykinin-A (PPTA), which encodes mainly for the neuropeptide substance P, can protect against lung injury and mortality in sepsis. Hegde et al. explore differential gene expression in PPTA- deficient mouse lung tissue eight hours after inducing microbial sepsis via cecal ligation and puncture. They found that genetic deletion of substance P resulted in a significantly different expression profile of genes involved in inflammation and immunomodulation after the induction of sepsis, compared with wild-type mice. Of note, the interleukin-1 receptor antagonist gene was elevated in PPTA^–/– septic mice. The authors postulate that the observed, elevated levels of inflammatory gene expression in the early stages of sepsis in PPTA knockout mice could point to treatment options that limit excessive immunosuppression.
Page 188 l View article: PDF (6.8 MB)

PPAR Signaling Pathway and Cancer-Related Proteins Are Involved in Celiac Disease-Associated Tissue Damage
Maria Paola Simula, Renato Cannizzaro, Vincenzo Canzonieri, Alessandro Pavan, Stefania Maiero, Giuseppe Toffoli, and Valli De Re
Celiac disease (CD) is an immune-mediated disorder triggered by ingestion of wheat gliadin and other related proteins in genetically predisposed individuals. Currently, a permanent gluten-free diet is the only accepted therapy for CD. CD can be difficult to diagnose because of lack of concordance with serological and histological findings. In this work, Simula et al. sought to develop a diagnostic CD signature and to gain a better understanding of pathogenic mechanisms associated with CD. They analyzed intestinal mucosa proteome alterations of CD patients with varying degrees of histological abnormalities. Results indicate that downregulation of proteins involved in peroxisome proliferator-activated receptor (PPAR) signalling and the modulation of several cancer-related proteins are associated with the highest CD histological scores. The data suggest PPAR may be a therapeutic target for modulation of inflammation in CD and warrants additional research.
Page 199 l View article: PDF (4.9 MB)

ACE2 Activation Promotes Antithrombotic Activity
Rodrigo A Fraga-Silva, Brian S Sorg, Mamta Wankhede, Casey deDeugd, Joo Y Jun, Matthew B Baker, Yan Li, Ronald K Castellano, Michael J Katovich, Mohan K Raizada, and Anderson J Ferreira
Thrombogenic events, such as ischemic stroke, pulmonary embolism, deep venous thrombosis, mesenteric ischemia and acute coronary syndrome, are major complications of certain pathological conditions, such as hypertension, atherosclerosis and diabetes mellitus. Despite many therapeutic advances and increasingly effective drug treatments, thrombogenic events remain the major cause of morbidity and mortality worldwide. Recent data suggest activation of the ACE2/Ang-(1-7)/Mas axis produces antithrombotic activity. In this work, Fraga-Silva et al. evaluated the role of ACE2 in thrombus formation in normotension and hypertension in vivo and tested a novel ACE2 activator (XNT) on thrombus formation. Results demonstrate the pharmacological activation of ACE2 by XNT attenuated platelet attachment to vessels and thrombus formation. These results suggest that XNT could be a potential lead compound for the treatment of thrombogenic diseases.
Page 210 l View article: PDF (1.3 MB)

α-Galactosidase A-Tat Fusion Enhances Storage Reduction in Hearts and Kidneys of Fabry Mice
Koji Higuchi, Makoto Yoshimitsu, Xin Fan, Xiaoxin Guo, Vanessa I Rasaiah, Jennifer Yen, Chuwa Tei, Toshihiro Takenaka, and Jeffrey A Medin
Fabry disease is a lysosomal storage disorder (LSD) caused by a deficiency of α-galactosidase A activity (α-gal A). This leads to buildup of globotriaosylceramide (Gb3) resulting in cardiac, renal and cerebrovascular disease. Fabry disease is the second most prevalent LSD and a model for the development of therapy for single gene defects. While enzyme replacement therapy is available, it requires frequent lifelong infusions and only seems to slow progression of the disorder. Because gene therapy is a promising approach for Fabry disease, Higuchi et al. sought to optimize a construct for α-gal A delivery. The authors demonstrate that administration of a lentivector containing α-gal A fused to a region of Tat (a protein transduction domain from HIV that allows proteins to penetrate the cell membrane) more efficiently reduces Gb3 accumulation in Fabry hearts and kidneys than the vector with α-gal A alone. These data may advance gene therapy for Fabry disease, and suggest that α-gal A linked to Tat may render enzyme replacement therapy more effective.
Page 216 l View article: PDF (248 KB)

Review Article

Cellular Endocytosis and Gene Delivery
Jennifer E Ziello, Yan Huang, and Ion S Jovin
Gene therapy is presently being investigated for its therapeutic potential in treating a number of maladies. Gene therapy relies upon a variety of viral and nonviral vectors which are delivered to target body cells and subsequently endocytosed and dissembled. The mechanisms by which vectors such as adenoviruses, adeno-associated viruses, retroviruses and liposomes enter the cell are being increasingly focused upon, as the effort to increase the efficiency of gene therapy continues. Ziello et al. focus on the mechanisms of endocytosis and how they relate to the trafficking of viral and nonviral vectors in gene therapy.
Page 222 l View article: PDF (475 KB)