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EMBO Reports Jun 2001Angiostatin is a cleavage product of plasminogen that has anti-angiogenic properties. We investigated whether the effects of angiostatin on endothelial cells are...
Angiostatin is a cleavage product of plasminogen that has anti-angiogenic properties. We investigated whether the effects of angiostatin on endothelial cells are mediated by ceramide, a lipid implicated in endothelial cell signaling. Our results demonstrate that angiostatin produces a transient increase in ceramide that correlates with actin stress fiber reorganization, detachment and death. DNA array expression analysis performed on ceramide-treated human endothelial cells demonstrated induction of certain genes involved in cytoskeleton organization. Specifically, we report that treatment with angiostatin or ceramide results in the activation of RhoA, an important effector of cytoskeletal structure. We also show that treatment of endothelial cells with the antioxidant N-acetylcysteine abrogates morphological changes and cytotoxic effects of treatment with angiostatin or ceramide. These findings support a model in which angiostatin induces a transient rise in ceramide, RhoA activation and free radical production.
Topics: Angiostatins; Cell Membrane; Cells, Cultured; Cytoskeleton; Dose-Response Relationship, Drug; Endothelium, Vascular; Homeodomain Proteins; Humans; Immunoblotting; Kinetics; LIM-Homeodomain Proteins; Microscopy, Phase-Contrast; Nerve Tissue Proteins; Oligonucleotide Array Sequence Analysis; Peptide Fragments; Plasminogen; Protein Transport; Signal Transduction; Sphingosine; Time Factors; Transcription Factors; Umbilical Veins; rhoA GTP-Binding Protein
PubMed: 11415988
DOI: 10.1093/embo-reports/kve115 -
American Journal of Physiology. Renal... Jan 2009Angiostatin, a proteolytic fragment of plasminogen, is a potent anti-angiogenic factor recently shown also to have an inhibitory effect on leukocyte recruitment and...
Angiostatin, a proteolytic fragment of plasminogen, is a potent anti-angiogenic factor recently shown also to have an inhibitory effect on leukocyte recruitment and macrophage migration. Because both angiogenesis and inflammation play key roles in the progression of chronic kidney disease, we evaluated the effect of angiostatin treatment in the rat remnant kidney model. Rats were pretreated for 4 wk with recombinant adeno-associated viruses expressing either angiostatin or green fluorescence protein. Chronic renal disease was then induced by a subtotal nephrectomy, and rats were killed 8 wk later for analysis. Angiostatin treatment was associated with significantly less proteinuria but no alterations in serum creatinine, creatinine clearance, and blood urea nitrogen levels. Treatment with angiostatin reduced renal peritubular capillary number and decreased urinary nitric oxide levels. Despite reducing capillary density, angiostatin diminished interstitial fibrosis in association with reduced macrophage and T-cell infiltration and renal monocyte chemoattractant protein-1 mRNA levels. In conclusion, angiostatin overexpression was associated with attenuated renal disease progression in a model of chronic kidney injury, likely because of its anti-inflammatory actions. However, its anti-angiogenic actions suggest countering effects that could partially offset its benefit in chronic kidney diseases.
Topics: Adenoviridae; Angiostatins; Animals; Blood Urea Nitrogen; Chronic Disease; Creatinine; Disease Models, Animal; Fibrosis; Green Fluorescent Proteins; Inflammation; Kidney; Kidney Diseases; Male; Nitric Oxide; Proteinuria; Rats; Rats, Sprague-Dawley
PubMed: 18971211
DOI: 10.1152/ajprenal.90430.2008 -
Science (New York, N.Y.) Apr 1999
Topics: Angiostatins; Cell Membrane; Endothelium, Vascular; Humans; Hydrogen-Ion Concentration; Neovascularization, Pathologic; Peptide Fragments; Plasminogen; Proton Pumps; Proton-Translocating ATPases; Vacuolar Proton-Translocating ATPases
PubMed: 10232985
DOI: 10.1126/science.284.5413.433d -
Science (New York, N.Y.) Apr 1999
Topics: Adenosine Triphosphate; Angiostatins; Cell Membrane; Endothelium, Vascular; Humans; Hydrogen-Ion Concentration; Neoplasms; Peptide Fragments; Plasminogen; Proton Pumps; Proton-Motive Force; Proton-Translocating ATPases
PubMed: 10232986
DOI: No ID Found -
Toxicology and Industrial Health Jul 2013Antiangiogenic therapy is supposed to be an attractive approach for antitumor treatment. Human plasminogen-derived angiostatin K1-3 is one of the most potent...
Antiangiogenic therapy is supposed to be an attractive approach for antitumor treatment. Human plasminogen-derived angiostatin K1-3 is one of the most potent antiangiogenic agents known currently. However, it is unclear whether angiostatin has got protective effects on colon cancer. So we investigated the protective effects of angiostatin on 1,2-dimethylhydrazine (DMH)-induced colon cancer in mice. Thirty Balb/C male mice, weighing 25-30 g and 8 weeks of age, were used. Twenty of the mice were treated with DMH subcutaneously (20 mg/kg) once a week for 12 weeks. Six mice died during the DMH injection and surviving mice were divided into two groups (7 mice in DMH and 7 mice in DMH + angiostatin groups). In the angiostatin group, 6 weeks after the last DMH injection the animals were first treated with angiostatin (20 μg/mouse) intraperitoneally and then subcutaneously every 48 h (5 μg/mouse) throughout a period of 12 weeks. The animals were killed after 30 weeks for histopathological examination. When we look at the distribution of lesions in the colon, they mainly occurred in the distal colon. The incidence of mean colonic lesions in a tumor-bearing mouse was 9.85 ± 4.91 in those treated with DMH and 8.71 ± 3.49 in those treated with angiostatin. The incidence of colon tumors was not significantly affected by low dose of angiostatin, and we noticed that the number of lesions decreased by 12% in DMH + angiostatin group compared to the number of the lesions in DMH group, but this decrease was not statistically significant (p > 0.05). The administration period of angiostatin corresponds to the precancerous period and the reduction in the number of lesions could be important for the protective function of angiostatin in DMH + angiostain group. We assume that therapeutic effects of angiostatin are related to its doses, route of administration, frequency and administration period. In addition, we believe that combination of high doses of angiostatin with radiation, gene therapy or chemotherapy might be successful in proper tumor model.
Topics: 1,2-Dimethylhydrazine; Analysis of Variance; Angiogenesis Inhibitors; Angiostatins; Animals; Colonic Neoplasms; Histocytochemistry; Male; Mice; Mice, Inbred BALB C
PubMed: 22393105
DOI: 10.1177/0748233712440137 -
BMC Cancer Jun 2006Upregulation of endogenous angiostatin levels may constitute a novel anti-angiogenic, and therefore anti-tumor therapy. In vitro, angiostatin generation is a two-step... (Comparative Study)
Comparative Study
BACKGROUND
Upregulation of endogenous angiostatin levels may constitute a novel anti-angiogenic, and therefore anti-tumor therapy. In vitro, angiostatin generation is a two-step process, starting with the conversion of plasminogen to plasmin by plasminogen activators (PAs). Next, plasmin excises angiostatin from other plasmin molecules, a process requiring a donor of a free sulfhydryl group. In previous studies, it has been demonstrated that administration of PA in combination with the free sulfhydryl donor (FSD) agents captopril or N-acetyl cysteine, resulted in angiostatin generation, and anti-angiogenic and anti-tumour activity in murine models.
METHODS
In this study we have investigated the angiostatin generating capacities of several FSDs. D-penicillamine proved to be most efficient in supporting the conversion of plasminogen to angiostatin in vitro. Next, from the optimal concentrations of tPA and D-penicillamine in vitro, equivalent dosages were administered to healthy Balb/c mice to explore upregulation of circulating angiostatin levels. Finally, anti-tumor effects of treatment with tPA and D-penicillamine were determined in a human melanoma xenograft model.
RESULTS
Surprisingly, we found that despite the superior angiostatin generating capacity of D-penicillamine in vitro, both in vivo angiostatin generation and anti-tumour effects of tPA/D-penicillamine treatment were impaired compared to our previous studies with tPA and captopril.
CONCLUSION
Our results indicate that selecting the most appropriate free sulfhydryl donor for anti-angiogenic therapy in a (pre)clinical setting should be performed by in vivo rather than by in vitro studies. We conclude that D-penicillamine is not suitable for this type of therapy.
Topics: Angiostatins; Animals; Antineoplastic Combined Chemotherapy Protocols; Humans; In Vitro Techniques; Melanoma; Mice; Mice, Inbred BALB C; Mice, Nude; Penicillamine; Plasminogen Activators; Xenograft Model Antitumor Assays
PubMed: 16753063
DOI: 10.1186/1471-2407-6-149 -
Blood Feb 2005Angiogenesis and inflammation are closely related biologic processes in wound healing and the responses to vascular injury as well as in cardiovascular diseases;...
Angiogenesis and inflammation are closely related biologic processes in wound healing and the responses to vascular injury as well as in cardiovascular diseases; however, the molecular connections are poorly defined. In particular, it is yet unclear whether endogenous factors can regulate both angiogenesis and inflammation. Here, we show that the endogenous angiogenesis inhibitor, angiostatin (containing kringle domains 1-4 of plasminogen), serves an anti-inflammatory role, since the kringles 1-3 and its kringle 4 directly interact with leukocyte beta1- and beta2-integrins, respectively. In particular, a specific interaction between kringle 4 and alphaMbeta2-integrin (Mac-1) but not leukocyte function antigen 1 (LFA-1) was identified. Angiostatin thereby inhibited beta1- and beta2-integrin-mediated adhesion of leukocytes to extracellular matrix proteins and the endothelium as well as their transmigration through the endothelium in vitro. Moreover, angiostatin blocked the peritonitis-induced neutrophil emigration in vivo. In addition, through its interaction with Mac-1, angiostatin reduced activation of the proinflammatory transcription factor nuclear factor kappaB (NFkappaB), as well as the NFkappaB-related expression of tissue factor, a potent initiator of hemostasis following vascular injury. Finally, angiostatin forms were generated in vivo following skin injury/inflammation and were detectable during the following entire period of wound healing peaking at the terminal phase of the healing process. Taken together, over and above inhibition of neovascularization, angiostatin was identified as an antiadhesive/anti-inflammatory substance. These observations could provide the basis for new therapeutic applications of angiostatin to target chronic inflammatory processes in different pathologic situations.
Topics: Angiogenesis Inhibitors; Angiostatins; Animals; Anti-Inflammatory Agents, Non-Steroidal; Cell Adhesion; Cell Line, Tumor; Cell Movement; Disease Models, Animal; Endothelium, Vascular; Humans; K562 Cells; Leukemia, Myeloid, Acute; Leukocytes; Mice; Peritonitis
PubMed: 15383457
DOI: 10.1182/blood-2004-01-0166 -
Haematologica Jul 1999The discovery of specific endothelial inhibitors such as angiostatin and endostatin not only increases our understanding of the functions of these molecules in the... (Review)
Review
The discovery of specific endothelial inhibitors such as angiostatin and endostatin not only increases our understanding of the functions of these molecules in the regulation of physiological and pathological angiogenesis, but also provides an important therapeutic strategy for cancer treatment. Recent studies have demonstrated that the angiostatin protein significantly suppresses the growth of a variety of tumors in mice. However, the dosages of angiostatin protein used in these animal studies seem to be too high for clinical trials. In addition, repeated injections and long-term treatment with angiostatin are required to reach its maximal antitumor effect. In this article, I will discuss several alternative approaches that may become feasible to move angiostatin therapy from animal experiments into the clinic. In particular, I will emphasize the therapeutic potentials of angiostatin gene therapy and more potent angiogenesis inhibitors that are related to angiostatin.
Topics: Angiostatins; Animals; Genetic Therapy; Humans; Mice; Neoplasms; Neoplasms, Experimental; Neovascularization, Pathologic; Peptide Fragments; Plasminogen
PubMed: 10406908
DOI: No ID Found -
Arthritis and Rheumatism Mar 2002To determine the efficacy of local therapy with human angiostatin gene in murine collagen-induced arthritis (CIA).
OBJECTIVE
To determine the efficacy of local therapy with human angiostatin gene in murine collagen-induced arthritis (CIA).
METHODS
DBA/1 mice were immunized with bovine type II collagen. Before the onset of arthritis, NIH3T3 fibroblasts, transduced with angiostatin-expressing retroviral vectors or control vectors, were transplanted into the knee cavity. The incidence of arthritis in the knee joints was evaluated histologically based on pannus formation and cartilage destruction. Paws were evaluated macroscopically for redness, swelling, and deformities and immunologically for levels of interleukin-1 beta. Angiogenesis in paws and knee joints was studied by immunohistochemistry using anti-CD31 antibody and measurement of von Willebrand factor levels.
RESULTS
Pannus formation and cartilage erosion were dramatically reduced in knees transplanted with angiostatin-expressing cells. In addition, the onset of CIA in the ipsilateral paws below the knees injected with the angiostatin gene was significantly prevented. Furthermore, angiostatin gene transfer inhibited arthritis-associated angiogenesis.
CONCLUSION
Local production of angiostatin in the knee was able to prevent the onset of CIA not only in the knee injected with genetically engineered cells, but also in the uninjected ipsilateral paw. This suggests that transfer of the angiostatin gene, and potentially also its protein, may provide a new, effective approach to the treatment of rheumatoid arthritis.
Topics: 3T3 Cells; Angiostatins; Animals; Arthritis, Experimental; Blood Vessels; Cattle; Cell Count; Cell Line; Gene Expression; Genetic Therapy; Hindlimb; Humans; Joints; Mice; Neovascularization, Pathologic; Peptide Fragments; Plasminogen; Time Factors
PubMed: 11920417
DOI: 10.1002/art.10113 -
The Journal of Surgical Research Jun 1998Angiostatin, a proteolytic fragment of plasminogen, is a potent inhibitor of angiogenesis. In vitro, angiostatin can be generated by pancreatic elastase proteolysis of...
BACKGROUND
Angiostatin, a proteolytic fragment of plasminogen, is a potent inhibitor of angiogenesis. In vitro, angiostatin can be generated by pancreatic elastase proteolysis of plasminogen; however, in vivo, the enzymes responsible for angiostatin production are not known. A recent study demonstrates the involvement of a serine protease in angiostatin generation. In this study we sought to determine if the human pancreatic carcinoma cell line ASPC1 produced enzymatic activity capable of converting plasminogen to angiostatin and to determine if urokinase plasminogen activator (uPA) is involved in this system. Methods. ASPC1 cells were grown to near confluence in 20% FBS-RPMI. Media were changed to serum free and cells cultured for an additional 24 h. The serum free conditioned media (SFCM) was obtained. Angiostatin generation was determined by incubating 20 microg of human plasminogen with 100 microl of SFCM for 0, 3, 8, 12, 24, and 48 h. Plasminogen cleavage was assessed in the presence of the following protease inhibitors: pefabloc, aprotinin, phosphoramidon, leupeptin, and EDTA. The effect of uPA on angiostatin generation was determined by incubating plasminogen with antibody to uPA. Angiostatin generation was determined by Western blot.
RESULTS
Incubation of plasminogen with SFCM resulted in the generation of immunoreactive bands at 48 kDa corresponding to human angiostatin. Angiostatin generation by ASPC1 SFCM was time dependent; there was a significant decrease in the plasminogen substrate beginning at 3 h with complete conversion to angiostatin by 48 h. Enzymatic activity leading to angiostatin production was found to be due to a serine protease. Antibody to uPA effectively blocked angiostatin production by ASPC1 SFCM in a dose-dependent manner.
CONCLUSION
Human pancreatic cancer cells express enzymatic activity which leads to the generation of angiostatin. Conversion of plasminogen to angiostatin is due to a serine protease. This serine protease is most likely uPA.
Topics: Angiostatins; Aprotinin; Culture Media, Serum-Free; Humans; Pancreatic Neoplasms; Peptide Fragments; Plasminogen; Plasminogen Activators; Serine Proteinase Inhibitors; Sulfones; Tumor Cells, Cultured; Urokinase-Type Plasminogen Activator
PubMed: 9698533
DOI: 10.1006/jsre.1998.5334