Prophylactic adenovirus-mediated human kallistatin gene therapy suppresses rat arthritis by inhibiting angiogenesis and inflammation

Mesenchymal stem cells and osteoarthritis: remedy or accomplice?

Multipotent mesenchymal stromal or stem cells (MSCs) are likely to be agents of connective tissue homeostasis and repair. Because the hallmark of osteoarthritis (OA) is degeneration and failure to repair connective tissues it is compelling to think that these cells have a role to play in OA. Indeed, MSCs have been implicated in the pathogenesis of OA and, in turn, progression of the disease has been shown to be therapeutically modulated by MSCs. This review discusses current knowledge on the potential of both marrow- and local joint-derived MSCs in OA, the mode of action of the cells, and possible effects of the osteoarthritic niche on the function of MSCs. The use of stem cells for repair of isolated cartilage lesions and strategies for modulation of OA using local cell delivery are discussed as well as therapeutic options for the future to recruit and appropriately activate endogenous progenitors and/or locally systemically administered MSCs in the early stages of the disease. The use of gene therapy protocols, particularly as they pertain to modulation of inflammation associated with the osteoarthritic niche, offer an additional option in the treatment of this chronic disease. In summary, elucidation of the etiology of OA and development of technologies to detect early disease, allied to an increased understanding of the role MSCs in aging and OA, should lead to more targeted and efficacious treatments for this debilitating chronic disease in the future.

Protection of the liver against CCl4-induced injury by intramuscular electrotransfer of a kallistatin-encoding plasmid

AIM: To investigate the effect of transgenic expression of kallistatin (Kal) on carbon tetrachloride (CCl₄)-induced liver injury by intramuscular (im) electrotransfer of a Kal-encoding plasmid formulated with poly-L-glutamate (PLG).

METHODS: The pKal plasmid encoding Kal gene was formulated with PLG and electrotransferred into mice skeletal muscle before the administration of CCl₄. The expression level of Kal was measured. The serum biomarker levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), malonyldialdehyde (MDA), and tumor necrosis factor (TNF)-α were monitored. The extent of CCl₄-induced liver injury was analyzed histopathologically.

RESULTS: The transgene of Kal was sufficiently expressed after an im injection of plasmid formulated with PLG followed by electroporation. In the Kal gene-transferred mice, protection against CCl₄-induced liver injury was reflected by significantly decreased serum ALT, AST, MDA and TNF-α levels compared to those in control mice (P < 0.01 to 0.05 in a dose-dependent manner). Histological observations also revealed that hepatocyte necrosis, hemorrhage, vacuolar change and hydropic degeneration were apparent in mice after CCl₄ administration. In contrast, the damage was markedly attenuated in the Kal gene-transferred mice. The expression of hepatic fibrogenesis marker transforming growth factor-β1 was also reduced in the pKal transferred mice.

CONCLUSION: Intramuscular electrotransfer of plasmid pKal which was formulated with PLG significantly alleviated the CCl₄-induced oxidative stress and inflammatory response, and reduced the liver damage in a mouse model.

Increased serum kallistatin levels in type 1 diabetes patients with vascular complications

BACKGROUND

Kallistatin, a serpin widely produced throughout the body, has vasodilatory, anti-angiogenic, anti-oxidant, and anti-inflammatory effects. Effects of diabetes and its vascular complications on serum kallistatin levels are unknown.

METHODS

Serum kallistatin was quantified by ELISA in a cross-sectional study of 116 Type 1 diabetic patients (including 50 with and 66 without complications) and 29 non-diabetic controls, and related to clinical status and measures of oxidative stress and inflammation.

RESULTS

Kallistatin levels (mean(SD)) were increased in diabetic vs. control subjects (12.6(4.2) vs. 10.3(2.8) μg/ml, p = 0.007), and differed between diabetic patients with complications (13.4(4.9) μg/ml), complication-free patients (12.1(3.7) μg/ml), and controls; ANOVA, p = 0.007. Levels were higher in diabetic patients with complications vs. controls, p = 0.01, but did not differ between complication-free diabetic patients and controls, p > 0.05. On univariate analyses, in diabetes, kallistatin correlated with renal dysfunction (cystatin C, r = 0.28, p = 0.004; urinary albumin/creatinine, r = 0.34, p = 0.001; serum creatinine, r = 0.23, p = 0.01; serum urea, r = 0.33, p = 0.001; GFR, r = -0.25, p = 0.009), total cholesterol (r = 0.28, p = 0.004); LDL-cholesterol (r = 0.21, p = 0.03); gamma-glutamyltransferase (GGT) (r = 0.27, p = 0.04), and small artery elasticity, r = -0.23, p = 0.02, but not with HbA1c, other lipids, oxidative stress or inflammation. In diabetes, geometric mean (95%CI) kallistatin levels adjusted for covariates, including renal dysfunction, were higher in those with vs. without hypertension (13.6 (12.3-14.9) vs. 11.8 (10.5-13.0) μg/ml, p = 0.03). Statistically independent determinants of kallistatin levels in diabetes were age, serum urea, total cholesterol, SAE and GGT, adjusted r2 = 0.24, p < 0.00001.

CONCLUSIONS

Serum kallistatin levels are increased in Type 1 diabetic patients with microvascular complications and with hypertension, and correlate with renal and vascular dysfunction.

Kallistatin attenuates endothelial apoptosis through inhibition of oxidative stress and activation of Akt-eNOS signaling

Kallistatin is a regulator of vascular homeostasis capable of controlling a wide spectrum of biological actions in the cardiovascular and renal systems. We previously reported that kallistatin inhibited intracellular reactive oxygen species formation in cultured cardiac and renal cells. The present study was aimed to investigate the role and mechanisms of kallistatin in protection against oxidative stress-induced vascular injury and endothelial cell apoptosis. We found that kallistatin gene delivery significantly attenuated aortic superoxide formation and glomerular capillary loss in hypertensive DOCA-salt rats. In cultured endothelial cells, kallistatin suppressed TNF-α-induced cellular apoptosis, and the effect was blocked by the pharmacological inhibition of phosphatidylinositol 3-kinase and nitric oxide synthase (NOS) and by the knockdown of endothelial NOS (eNOS) expression. The transduction of endothelial cells with adenovirus expressing dominant-negative Akt abolished the protective effect of kallistatin on endothelial apoptosis and caspase activity. In addition, kallistatin inhibited TNF-α-induced reactive oxygen species formation and NADPH oxidase activity, and these effects were attenuated by phosphatidylinositol 3-kinase and NOS inhibition. Kallistatin also prevented the induction of Bim protein and mRNA expression by oxidative stress. Moreover, the downregulation of forkhead box O 1 (FOXO1) and Bim expression suppressed TNF-α-mediated endothelial cell death. Furthermore, the antiapoptotic actions of kallistatin were accompanied by Akt-mediated FOXO1 and eNOS phosphorylation, as well as increased NOS activity. These findings indicate a novel role of kallistatin in the protection against vascular injury and oxidative stress-induced endothelial apoptosis via the activation of Akt-dependent eNOS signaling.

Kallistatin inhibits vascular inflammation by antagonizing tumor necrosis factor-alpha-induced nuclear factor kappaB activation

Kallistatin is a plasma protein with anti-inflammatory properties. In this study, we investigated the role and mechanisms of kallistatin in inhibiting endothelial inflammation through its heparin-binding domain. We showed that recombinant wild-type kallistatin dose-dependently competed with tumor necrosis factor (TNF)-alpha binding to TNF-alpha receptor in endothelial cells, whereas kallistatin mutant at the heparin-binding domain had no effect. Kallistatin, but not kallistatin mutant at the heparin-binding domain, abrogated TNF-alpha-induced endothelial cell activation, as evidenced by inhibition of TNF receptor 1-associated death domain protein activation, inhibitor of nuclear factor kappaB-alpha degradation, nuclear factor kappaB translocation, and p38 mitogen-activated protein kinase phosphorylation, as well as cell adhesion molecule and cytokine expression. Moreover, kallistatin, but not kallistatin mutant at the heparin-binding domain, inhibited TNF-alpha-induced human monocytic THP-1 cell adhesion to endothelial cells and prevented vascular endothelial growth factor-induced endothelial permeability. In mice, kallistatin gene delivery prevented vascular leakage provoked by complement factor C5a, whereas delivery of kallistatin heparin mutant gene had no effect. Similarly, gene transfer of kallistatin, but not the kallistatin heparin mutant, inhibited collagen/adjuvant-induced arthritis in rats. These results indicate that kallistatin's heparin-binding site plays an essential role in preventing TNF-alpha-mediated endothelial activation and reducing vascular endothelial growth factor-induced vascular permeability, resulting in attenuation of vascular inflammation in cultured endothelial cells and animal models. This study identifies a protective role of kallistatin in vascular injury, thereby implicating the therapeutic potential of kallistatin for vascular and inflammatory diseases.

Inhibition of experimental lung metastasis by systemic lentiviral delivery of kallistatin

Background

Angiogenesis plays an important role in the development and progression of tumors. Kallistatin exerts anti-angiogenic and anti-inflammatory activities that may be effective in inhibiting tumor metastasis. We investigated the antitumor effect of lentivirus-mediated kallistatin gene transfer in a syngeneic murine tumor model.

Methods

Lentiviral vector encoding kallistatin (LV-Kallistatin) was constructed. The expression of kallistatin was verified by enzyme-linked immunosorbent assay (ELISA), and the bioactivity of kallistatin was determined by using cell proliferation, migration, and invasion assays. In addition, antitumor effects of LV-Kallistatin were evaluated by the intravenous injection of virus into tumor-bearing mice.

Results

The conditioned medium from LV-Kallistatin-treated cells inhibited the migration and proliferation of endothelial cells. Meanwhile, it also reduced the migration and invasion of tumor cells. In the experimental lung metastatic model, tumor-bearing mice receiving LV-Kallistatin had lower tumor nodules and longer survival than those receiving control virus or saline. Moreover, the microvessel densities, the levels of vascular endothelial growth factor (VEGF), tumor necrosis factor (TNF)-α, and nuclear factor κB (NF-κB) transcriptional activity were reduced in the LV-Kallistatin-treated mice.

Conclusion

Results of this study showed that systemic administration of lentiviral vectors encoding kallistatin inhibited the growth of metastatic tumor and prolonged the survival of tumor-bearing mice. These results suggest that gene therapy using lentiviruses carrying the kallistatin gene, which exerts anti-angiogenic and anti-inflammatory activities, represents a promising strategy for the treatment of lung cancer.

Multifunctional photopolymerized semiinterpenetrating network (sIPN) system containing bupivacaine and silver sulfadiazine is an effective donor site treatment in a swine model

Previously, we have shown in a cross-comparison study that multifunctional photopolymerized semiinterpenetrating network (sIPN) system is an effective donor site treatment in a swine model. The advantages of sIPN include spray-on application, in situ photopolymerization, and ability to cover large contoured areas. sIPN has also been shown to be an effective delivery vehicle for keratinocyte growth factor, dexamethasone, bupivacaine, and silver sulfadiazine in vitro. Our aim for this study was to show that these products delivered to the wound bed with sIPN would not change the wound healing characteristics compared with the control site through qualitative clinical evaluation and to compare the rate and quality of donor site healing through histologic evaluation. Eight Yucatan swine of 40 lbs each were randomly divided into four groups of two pigs before surgery. Each animal had 5.6% TBSA of skin harvested from two different dorsal regions, with one at 22/1000th-inch and the other at 30/1000th-inch setting on the dermatome. Each test site on each animal was then sequentially dressed with 50 cm(2) of Xeroform gauze, sIPN, sIPN loaded with 0.5% bupivacaine, or sIPN loaded with 1% silver sulfadiazine. sIPN with or without soluble drugs were applied as liquid, then photopolymerized in situ to form an elastic covering. Each of the test areas was separated by 50 cm(2) of autograft, which was used to divide the test areas. Wound assessment and killing occurred at days 7, 9, 14, and 21. A full-thickness biopsy was taken from each of the study areas for histological analysis. By 14 days, all areas showed complete epidermal coverage histologically. The 30/1000th-inch site revealed a thicker, more irregular dermis compared with the 22/1000th-site. Evaluation of the day-21 sites revealed equal thinning and flattening of the new epidermis. No site showed full restoration of the rete ridges. No signs of infection were seen in clinical or histological evaluations of any treatment. The addition of bupivacaine and silver sulfadiazine to sIPN does not show any alterations in wound healing of a donor site in a swine model when compared with sIPN without loaded drugs and a standard control dressing. This efficacy may be coupled with established localized sIPN drug delivery profiles and allow further studies to evaluate the efficacy of these drugs to promote healing, eradicate and prevent infection, and manage pain.

Pivotal role of JNK-dependent FOXO1 activation in downregulation of kallistatin expression by oxidative stress

Oxidative stress has been shown to suppress endothelial nitric oxide synthase expression through activation of the transcription factor forkhead box O 1 (FOXO1) in cultured endothelial cells. We previously reported that circulating kallistatin levels are markedly reduced in rats with chronic oxidative organ damage. In this study, we investigated the potential role of oxidative stress in suppression of kallistatin expression via FOXO1 activation. In Dahl salt-sensitive (DSS) rats, we found that high salt intake induced a time-dependent correlation of increased thiobarbituric acid reactive substances (TBARS, an indicator of lipid peroxidation) with reduced serum kallistatin levels. Moreover, salt loading provoked an elevation of in situ aortic superoxide formation in association with reduced kallistatin levels. Expression of kallistatin was identified in cultured endothelial cells by immunocytochemistry and flow cytometry; however, H(2)O(2) dose-dependently lowered kallistatin mRNA and protein levels as determined by real-time PCR and Western blot, respectively. Downregulation of kallistatin synthesis by oxidative stress was restored by knockdown of FOXO1 expression with small-interfering RNA. H(2)O(2) rapidly induced FOXO1 nuclear translocation, but the effect was blocked by c-Jun NH(2)-terminal kinase (JNK) inhibitor. Inhibition of JNK by pharmacological inhibitor or small-interfering RNA reversed H(2)O(2)'s effect on kallistatin expression in endothelial cells. This study demonstrates that an inverse relationship exists between oxidative stress and kallistatin levels in the circulation and blood vessels and that kallistatin expression is negatively regulated by oxidative stress via JNK-dependent FOXO1 activation in cultured endothelial cells.

Kruppel-like factor 4 is a novel mediator of Kallistatin in inhibiting endothelial inflammation via increased endothelial nitric-oxide synthase expression

Kallistatin is a plasma protein that exhibits pleiotropic effects in vasodilation, anti-angiogenesis, and anti-inflammation. To isolate a kallistatin-binding protein that mediates the vascular actions of kallistatin, we screened and identified a positive clone from a human heart cDNA expression library by using an alkaline phosphatase-kallistatin fusion protein binding assay. Sequence analysis revealed that kallistatin-binding protein is human Kruppel-like factor 4 (KLF4). KLF4 was localized on the plasma membrane of HEK-293 cells and endothelial cells overexpressing KLF4. KLF4 and kallistatin complex formation was identified in endothelial cells by immunoprecipitation followed by immunoblotting. We showed that kallistatin inhibits tumor necrosis factor-alpha-induced NF-kappaB activation, as well as vascular cell adhesion molecule-1 and monocyte chemoattractant protein-1 expression in endothelial cells, whereas knockdown of KLF4 by small interfering RNA oligonucleotide abolished the effect of kallistatin. Kallistatin increased endothelial nitric-oxide synthase (eNOS) expression and nitric oxide levels, and these effects were also blocked by KLF4 small interfering RNA oligonucleotide. Moreover, inhibition of eNOS by RNA interference or by NOS inhibitor abolished the blocking effect of kallistatin on vascular cell adhesion molecule-1 and monocyte chemoattractant protein-1 expression. In summary, we identified KLF4 as a kallistatin-binding protein, which has a novel role in mediating the anti-inflammatory actions of kallistatin via increasing eNOS expression in endothelial cells. This study provides a new target for modulating endothelial function in vascular disease.

Amelioration of experimental arthritis by a telomerase-dependent conditionally replicating adenovirus that targets synovial fibroblasts

OBJECTIVE

Synovial fibroblasts (SFs) play a pivotal role in the pathogenesis of rheumatoid arthritis (RA). It has been documented that the phenotype of rheumatoid synovium is similar, in many respects, to that of an aggressive tumor. In this study, a novel, genetically engineered adenovirus was designed to lyse SFs that exhibit high telomerase activity and p53 mutations, and its effects as a novel therapeutic strategy were assessed in an experimental arthritis model.

METHODS

An E1B-55-kd-deleted adenovirus driven by the human telomerase reverse transcriptase promoter was constructed (designated Ad.GS1). Cytolysis of SFs and productive replication of Ad.GS1 in the SFs of rats with collagen-induced arthritis (CIA), as well as the SFs of patients with RA (RASFs), were assessed in vitro and in vivo. Treatment responses, as well as the presence of disease-related cytokines and enzymes in the ankle joints, were determined in the murine model.

RESULTS

Ad.GS1 replicated in and induced cytolysis of human RASFs and SFs from arthritic rats, but spared normal fibroblasts. Bioluminescence imaging in vivo also demonstrated replication of Ad.GS1 in arthritic rat joints, but not in normal rat joints. Intraarticular administration of Ad.GS1 significantly reduced the ankle circumference, articular index scores, radiographic scores, and histologic scores and decreased the production of interleukin-1beta, matrix metalloproteinase 9, and prolyl 4-hydroxylase in rats with CIA compared with their control counterparts.

CONCLUSION

This study is the first to demonstrate the amelioration of arthritic symptoms by a novel, telomerase-dependent adenovirus in the rat CIA model, an experimental model that resembles human RA. In addition, the results suggest that because of its ability to induce cytolysis of SFs, this virus may be further explored as a therapeutic agent in patients with RA.

Role of kallistatin in prevention of cardiac remodeling after chronic myocardial infarction

Oxidative stress causes cardiomyocyte death and subsequent ventricular dysfunction and cardiac remodeling after myocardial infarction (MI), thus contributing to high mortality in chronic heart failure patients. We investigated the effects of kallistatin in cardiac remodeling in a chronic MI rat model and in primary cardiac cells. Human kallistatin gene was injected intramyocardially 20 min after ligation of the left coronary artery. At 4 weeks after MI, expression of human kallistatin in rat hearts was identified by reverse transcription-polymerase chain reaction, immunohistochemistry and ELISA. Kallistatin administration improved cardiac performance, increased mean arterial pressure, decreased myocardial infarct size and restored left ventricular wall thickness. Kallistatin treatment significantly attenuated cardiomyocyte size and atrial natriuretic peptide expression. Kallistatin also reduced collagen accumulation, collagen fraction volume and expression of collagen types I and III, transforming growth factor-beta1 (TGF-beta1) and plasminogen activator inhibitor-1 in the myocardium. Inhibition of cardiac hypertrophy and fibrosis by kallistatin was associated with increased cardiac nitric oxide (NO) levels and decreased superoxide formation, NADH oxidase activity and p22-phox expression. Moreover, in both primary cultured rat cardiomyocytes and myofibroblasts, recombinant kallistatin inhibited intracellular superoxide formation induced by H(2)O(2), and the antioxidant effect of kallistatin was abolished by Nomega-nitro-L-arginine methyl ester (L-NAME), indicating a NO-mediated event. Kallistatin promoted survival of cardiomyocytes subjected to H(2)O(2) treatment, and inhibited H(2)O(2)-induced Akt and ERK phosphorylation, as well as NF-kappaB activation. Furthermore, kallistatin abrogated TGF-beta-induced collagen synthesis and secretion in cultured myofibroblasts. This is the first study to demonstrate that kallistatin improves cardiac performance and prevents post-MI-induced cardiac hypertrophy and fibrosis through its antioxidant action.

Perspectives on the use of gene therapy for chronic joint diseases

Advances in molecular and cellular biology have identified a wide variety of proteins including targeted cytokine inhibitors, immunomodulatory proteins, cytotoxic mediators, angiogenesis inhibitors, and intracellular signalling molecules that could be of great benefit in the treatment of chronic joint diseases, such as osteo- and rheumatoid arthritis. Unfortunately, protein-based drugs are difficult to administer effectively. They have a high rate of turnover, requiring frequent readministration, and exposure in non-diseased tissue can lead to serious side effects. Gene transfer technologies offer methods to enhance the efficacy of protein-based therapies, enabling the body to produce these molecules locally at elevated levels for extended periods. The proof of concept of gene therapies for arthritis has been exhaustively demonstrated in multiple laboratories and in numerous animal models. This review attempts to condense these studies and to discuss the relative benefits and limitations of the methods proposed and to discuss the challenges toward translating these technologies into clinical realities.

Adeno-associated virus-mediated expression of kallistatin suppresses local and remote hepatocellular carcinomas

BACKGROUND

The current treatments for hepatocellular carcinoma (HCC) are poor, particularly for metastatic HCC. Intraportal transfusion of adeno-associated virus (AAV) leads to long-term and persistent transgenic expression in livers. Kallistatin, a novel angiogenesis inhibitor, exhibits anti-tumor activity. The aim of the study was to investigate whether intraportal injection of AAV-kallistatin could suppress local and metastatic HCC in mice.

METHODS

An AAV vector encoding kallistatin was constructed, and its transduction efficiency by intraportal transfusion in livers was examined by RT-PCR, immunohistochemical and Western blotting analysis. The anti-tumor activity was tested in three HCC models including hepatic and subcutaneous human Hep3B HCC tumors in BALB/c athymic (nu/nu) mice, and subcutaneous mouse BNL HCC tumors in BALB/c mice. Tumor cell proliferation in situ was examined by anti-Ki-67 staining, and apoptosis by TUNEL.

RESULTS

Gene transfection by rAAV-kallistatin inhibited proliferation of human umbilical vein endothelial cells and HCC cells in vitro. Intraportal injection of rAAV-kallistatin resulted in persistent and specific expression of kallistatin in livers detected by RT-PCR and immunohistochemical analysis, and kallistatin protein in circulation detected by Western blotting analysis. Intraportal injection of rAAV-kallistatin significantly suppressed angiogenesis and growth of hepatic Hep3B tumors. The kallistatin released by hepatocytes into the circulation suppressed remote Hep3B and BNL tumors established subcutaneously. The rAAV-kallistatin gene therapy significantly inhibited tumor cell proliferation and induced apoptosis.

CONCLUSIONS

Intraportal injection of rAAV-kallistatin suppressed hepatic and subcutaneous HCC tumors, relying on its anti-angiogenic and anti-proliferative activities.

Dramatic regulation of heparanase activity and angiogenesis gene expression in synovium from patients with rheumatoid arthritis

OBJECTIVE

Although heparanase is recognized as a proangiogenic factor, the involvement of heparanase in rheumatoid arthritis (RA) is unclear. In this study, we assessed heparanase activity in synovial fluid (SF) and synovial tissue (ST) from patients with RA or osteoarthritis (OA), and analyzed the expression of angiogenic pathway-focused genes in ST from RA and OA patients.

METHODS

SF and ST were obtained from the knees of patients with either RA or OA and from asymptomatic donors with no documented history of degenerative or inflammatory joint diseases. Heparanase activity was determined by an enzymatic assay using a radiolabeled substrate, and the presence of heparanase in ST was demonstrated by Western blotting. The expression of angiogenesis genes, including heparanase, in ST was analyzed by real-time quantitative polymerase chain reaction.

RESULTS

Heparanase activity was dramatically higher (>100-fold) in SF and ST from RA patients than in SF and ST from OA patients and asymptomatic donors. Active heparanase enzyme was detected and heparanase messenger RNA was up-regulated in ST from RA patients. We also found that angiogenesis gene expression was significantly regulated in RA synovium, and was correlated with heparanase activity.

CONCLUSION

These findings are novel and contribute to our understanding of joint destruction in RA, suggesting that heparanase may be a reliable prognostic factor for RA progression and an attractive target for the treatment of RA.

Salutary Effect of Kallistatin in Salt-Induced Renal Injury, Inflammation, and Fibrosis via Antioxidative Stress

An inverse relationship exists between kallistatin levels and salt-induced oxidative stress in Dahl-salt sensitive rats. We further investigated the role of kallistatin in inhibiting inflammation and fibrosis through antioxidative stress in Dahl-salt sensitive rats and cultured renal cells. High-salt intake in Dahl-salt sensitive rats induced elevation of thiobarbituric acid reactive substances (an indicator of lipid peroxidation), malondialdehyde levels, reduced nicotinamide-adenine dinucleotide phosphate oxidase activity, and superoxide formation, whereas kallistatin gene delivery significantly reduced these oxidative stress parameters. Kallistatin treatment improved renal function and reduced kidney damage as evidenced by diminished proteinuria and serum urea nitrogen levels, glomerular sclerosis, tubular damage, and protein cast formation. Kallistatin significantly decreased interstitial monocyte-macrophage infiltration and the expression of tumor necrosis factor-α, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1. Kallistain also reduced collagen fraction volume and the deposition and expression of collagen types I and III. Renal protection by kallistatin was associated with increased NO levels and endothelial NO synthase expression and decreased p38 mitogen-activated protein kinase, extracellular signal-regulated kinase phosphorylation, and transforming growth factor-β1 expression. Moreover, kallistatin attenuated tumor necrosis factor-α–induced intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression via inhibition of reactive oxygen species formation and p38 mitogen-activated protein kinase and nuclear factor-κB activation in cultured proximal tubular cells. Kallistatin inhibited fibronectin and collagen expression by suppressing angiotensin II–induced reactive oxygen species generation and transforming growth factor-β1 expression in cultured mesangial cells. These combined findings reveal that kallistatin is a novel antioxidant, which prevents salt-induced kidney injury, inflammation, and fibrosis by inhibiting reactive oxygen species–induced proinflammatory cytokine and transforming growth factor-β1 expression.

Kallikrein-binding protein inhibits growth of gastric carcinoma by reducing vascular endothelial growth factor production and angiogenesis

Kallikrein-binding protein (KBP) has been identified as an endogenous angiogenic inhibitor. We previously showed that KBP inhibited rat retinal neovascularization by down-regulation of vascular endothelial growth factor (VEGF) in endothelial cells. However, its antiangiogenic potential for inhibition of gastric carcinoma and the effect on VEGF in tumor cells have not been elucidated. The present study was designed to investigate the effect of KBP on growth of gastric carcinoma and the possible molecular mechanism. Recombinant KBP dose dependently inhibited proliferation and induced apoptosis of endothelial cells, but no effect on proliferation and apoptosis of SGC-7,901 gastric carcinoma cells. I.p. injection of KBP resulted in growth inhibition of both heterotopic and orthotopic gastric carcinoma xenografts at 61.4% and 52.3%, respectively. Microvessel density in tumor tissues treated with KBP was significantly decreased, suggesting that KBP suppressed tumor growth by antiangiogenesis. The expression and release of VEGF, a major angiogenic stimulator, were down-regulated by KBP in SGC-7,901 cells and gastric carcinoma xenografts. RNA levels of VEGF in SGC-7,901 cells were also decreased by KBP, thus suggesting the regulation at the transcriptional level. Therefore, hypoxia-inducible factor 1alpha (HIF-1alpha), a crucial transcriptional factor for VEGF expression, was examined in SGC-7,901 cells treated by KBP. KBP reduced HIF-1alpha protein level and nuclear translocation, which may be responsible for the down-regulation of VEGF transcription. Down-regulation of VEGF expression and release in tumor cells through inhibiting HIF-1alpha, thus attenuating the paracrine effect of VEGF on endothelial cell proliferation and vascular permeability in tumor tissues, may represent a novel mechanism for the antiangiogenic and antitumor activity of KBP.

Kallikrein-binding protein suppresses growth of hepatocellular carcinoma by anti-angiogenic activity

Effect of kallikrein-binding protein (KBP), an endogenous angiogenic inhibitor, on the growth of hepatocellular carcinoma and the possible mechanism were investigated. KBP inhibited proliferation and induced apoptosis of endothelial cells, but had no effect on the proliferation and apoptosis of hepatocarcinoma cell line HepG2. Intraperitoneal injection of KBP significantly suppressed the tumor growth and inhibited intratumoral neovascularization both in grafted hepatocarcinoma mice and xenografted hepatocarcinoma athymic mice. Moreover, KBP reduced expression of VEGF and HIF-1alpha nuclear translocation in HepG2 cells and xenografts. Down-regulation of VEGF in tumor cells through inhibiting HIF-1alpha may represent a novel mechanism for the anti-angiogenic and anti-tumor activity of KBP.

Prothymosin α Lacking the Nuclear Localization Signal as an Effective Gene Therapeutic Strategy in Collagen-Induced Arthritis

Prothymosin alpha (ProT) is regulated by c-Myc, an oncoprotein overexpressed in synovium of rheumatoid arthritis, and is associated with cell proliferation. However, ProT also exerts immunomodulatory activities. The growth-promoting activity of ProT can be abolished by deleting its nuclear localization signal (NLS). In this study, we showed that AdProTDeltaNLS, an adenoviral vector encoding ProT lacking the NLS, did not enhance the proliferation of synovial fibroblasts. AdProTDeltaNLS treatment abolished the up-regulation of the MIP-1alpha promoter activity induced by TNF-alpha in synovial fibroblasts. AdProTDeltaNLS suppressed macrophage chemotaxis and reduced macrophage infiltration into the ankle joints in rats with collagen-induced arthritis (CIA). Neutralization test confirmed the involvement of MIP-1alpha in macrophage chemotaxis. Administration of AdProTDeltaNLS reduced the severity of CIA in the clinical, radiographic, and histological aspects. The levels of TNF-alpha (mean +/- SEM, 1261.9 +/- 107.9 vs 2880.1 +/- 561.4 pg/mg total protein; p < 0.05), IL-1beta (56.8 +/- 8.0 vs 109.2 +/- 4.9 pg/mg total protein; p < 0.01), and MIP-1alpha (41.7 +/- 3.6 vs 55.2 +/- 1.1 pg/mg total protein; p < 0.05) in the ankle joints were lower in the AdProTDeltaNLS-treated rats with CIA than those in their control counterparts. In the AdProTDeltaNLS-treated ankle joints, matrix metalloproteinase-9 expression was decreased by 40% and infiltrating macrophages reduced by 50%. Our results demonstrate that intra-articular delivery of AdProTDeltaNLS significantly ameliorated the clinical course of CIA in rats. This study is the first to suggest that ProT lacking the NLS may have therapeutic potential for the management of rheumatoid arthritis.

Amelioration of collagen-induced arthritis in rats by nanogold

OBJECTIVE

Angiogenesis plays a part in the pathogenesis of rheumatoid arthritis (RA), and nanogold inhibits the activity of an angiogenic factor, vascular endothelial growth factor (VEGF). We therefore investigated whether intraarticular delivery of nanogold ameliorates collagen-induced arthritis (CIA) in rats.

METHODS

Binding of 13-nm nanogold to VEGF in human RA synovial fluid (SF) and its effects on RA SF-induced endothelial cell proliferation and migration were assessed. Nanogold was administered intraarticularly to rats with CIA before the onset of arthritis. Progression of CIA was monitored by measures of clinical, radiologic, and histologic changes. In addition, the microvessel density and extent of infiltrating macrophages as well as levels of tumor necrosis factor alpha (TNFalpha) and interleukin-1beta (IL-1beta) in the ankle joints were determined.

RESULTS

Nanogold bound to VEGF in RA SF, resulting in inhibition of RA SF-induced endothelial cell proliferation and migration. Significant reductions in ankle circumference, articular index scores, and radiographic scores were observed in the nanogold-treated rats with CIA compared with their control counterparts. In addition, the histologic score (of synovial hyperplasia, cartilage erosion, and leukocyte infiltration), microvessel density, macrophage infiltration, and levels of TNFalpha and IL-1beta were also significantly reduced in the ankle joints of nanogold-treated rats.

CONCLUSION

Our results are the first to demonstrate that intraarticular administration of nanogold ameliorates the clinical course of CIA in rats. Nanogold exerted antiangiogenic activities and subsequently reduced macrophage infiltration and inflammation, which resulted in attenuation of arthritis. These results demonstrate proof of principle for the use of nanogold as a novel therapeutic agent for the treatment of RA.

Novel Role of Kallistatin in Protection Against Myocardial Ischemia–Reperfusion Injury by Preventing Apoptosis and Inflammation

Kallistatin is a serine proteinase inhibitor that has been shown to reduce joint swelling and to inhibit inflammation in a rat model of arthritis. In this study, we investigated the effect and mechanisms of kallistatin on cardiac function after myocardial ischemia-reperfusion (I/R) injury. The human kallistatin gene in an adenoviral vector was delivered locally into rat heart 4 days before 30-min ischemia followed by 24-hr reperfusion. Kallistatin gene transfer significantly reduced myocardial infarct size and left ventricle end-diastolic pressure and improved cardiac contractility. Kallistatin significantly reduced I/R-induced cardiomyocyte apoptosis as identified by TUNEL and Hoechst staining, DNA laddering, cell viability, and caspase-3 activity in ischemic myocardium and in primary cultured cardiomyocytes. Kallistatin also reduced intramyocardial monocyte/macrophage and neutrophil accumulation in conjunction with decreased expression of monocyte chemoattractant protein-1, tumor necrosis factor-alpha, and intercellular adhesion molecule-1. Kallistatin delivery promoted cardiac endothelial nitric oxide synthase activation and increased nitric oxide (NO) formation, but inhibited NADH oxidase activity, p22phox expression, and superoxide production. Moreover, kallistatin reduced the phosphorylation of apoptosis signal-regulating kinase-1 and mitogen-activated protein kinases (MAPKs), but increased Akt and glycogen synthase kinase-3beta phosphorylation. The effects of kallistatin on cardiac function, oxidative stress, and these signal transduction events were all blocked by Nomega-nitro-L-argi-nine methyl ester. These results indicate a novel role of kallistatin in cardiac protection after I/R injury through increased NO formation and Akt-glycogen synthase kinase-3beta signaling and suppression of oxidative stress and MAPK activation.