mercaptopurine and Disease-Models--Animal

Heterogeneity in patient response to chemotherapy is consistently observed across patient populations. Pharmacogenomics is the study of inherited differences in interindividual drug disposition and effects, with the goal of selecting the optimal drug therapy and dosage for each patient. Pharmacogenomics is especially important for oncology, as severe systemic toxicity and unpredictable efficacy are hallmarks of cancer therapies. In addition, genetic polymorphisms in drug metabolizing enzymes and other molecules are responsible for much of the interindividual differences in the efficacy and toxicity of many chemotherapy agents. This review will discuss clinically relevant examples of gene polymorphisms that influence the outcome of cancer therapy, and whole-genome expression studies using microarray technology that have shown tremendous potential for benefiting cancer pharmacogenomics. The power and utility of the mouse as an experimental system for pharmacogenomic discovery will also be discussed in the context of cancer therapy.

Topics: Animals; Antimetabolites, Antineoplastic; Antineoplastic Agents, Phytogenic; Camptothecin; Dihydrouracil Dehydrogenase (NADP); Disease Models, Animal; DNA Adducts; DNA Repair; Fluorouracil; Glucuronosyltransferase; Glutathione Transferase; Humans; Irinotecan; Mercaptopurine; Methyltransferases; Neoplasms; Organoplatinum Compounds; Oxidoreductases; Pharmacogenetics; Polymorphism, Genetic; Thymidylate Synthase

Topics: Animals; Antibiotics, Antineoplastic; Antineoplastic Agents; Asparaginase; Azaserine; Cell Division; Clinical Trials as Topic; Cyclophosphamide; Cytarabine; Disease Models, Animal; Drug Combinations; Humans; Kinetics; Leukemia L1210; Leukemia, Experimental; Leukemia, Lymphoid; Leukemia, Myeloid, Acute; Mercaptopurine; Methotrexate; Neoplasms; Prednisone; Remission, Spontaneous; RNA, Neoplasm; Vincristine

Topics: Animals; Antibiotics, Antineoplastic; Antineoplastic Agents; Asparaginase; Azaserine; Cell Division; Clinical Trials as Topic; Cyclophosphamide; Cytarabine; Disease Models, Animal; Drug Combinations; Humans; Kinetics; Leukemia L1210; Leukemia, Experimental; Leukemia, Lymphoid; Leukemia, Myeloid, Acute; Mercaptopurine; Methotrexate; Neoplasms; Prednisone; Remission, Spontaneous; RNA, Neoplasm; Vincristine

When Zika virus emerged as a public health emergency there were no drugs or vaccines approved for its prevention or treatment. We used a high-throughput screen for Zika virus protease inhibitors to identify several inhibitors of Zika virus infection. We expressed the NS2B-NS3 Zika virus protease and conducted a biochemical screen for small-molecule inhibitors. A quantitative structure-activity relationship model was employed to virtually screen ∼138,000 compounds, which increased the identification of active compounds, while decreasing screening time and resources. Candidate inhibitors were validated in several viral infection assays. Small molecules with favorable clinical profiles, especially the five-lipoxygenase-activating protein inhibitor, MK-591, inhibited the Zika virus protease and infection in neural stem cells. Members of the tetracycline family of antibiotics were more potent inhibitors of Zika virus infection than the protease, suggesting they may have multiple mechanisms of action. The most potent tetracycline, methacycline, reduced the amount of Zika virus present in the brain and the severity of Zika virus-induced motor deficits in an immunocompetent mouse model. As Food and Drug Administration-approved drugs, the tetracyclines could be quickly translated to the clinic. The compounds identified through our screening paradigm have the potential to be used as prophylactics for patients traveling to endemic regions or for the treatment of the neurological complications of Zika virus infection.

Topics: Animals; Antiviral Agents; Artificial Intelligence; Chlorocebus aethiops; Disease Models, Animal; Drug Evaluation, Preclinical; High-Throughput Screening Assays; Immunocompetence; Inhibitory Concentration 50; Methacycline; Mice, Inbred C57BL; Protease Inhibitors; Quantitative Structure-Activity Relationship; Small Molecule Libraries; Vero Cells; Zika Virus; Zika Virus Infection

Several antineoplastic drugs have been proposed as new compounds for pulmonary arterial hypertension treatment but many have cardiotoxic side effects. The chemotherapeutic agent 6-mercaptopurine may have an effect in treatment of pulmonary arterial hypertension but at the same time, its effects on the afterload adaption of the right ventricle is unpredictable due to interaction with multiple downstream signalling pathways in the cardiomyocytes. We investigated the direct cardiac effects of 6-mercaptopurine in rats with isolated right heart failure caused by pulmonary trunk banding (PTB).. Male Wistar rat weanlings (112±2 g) were randomized to sham operation (sham, n = 10) or PTB. The PTB animals were randomized to placebo (PTB-control, n = 10) and 6-mercaptopurine (7.5 mg/kg/day) groups with treatment start before the PTB procedure (PTB-prevention, n = 10) or two weeks after (PTB-reversal, n = 10). Right ventricular effects were evaluated by echocardiography, cardiac MRI, invasive pressure-volume measurements, and histological and molecular analyses.. PTB increased right ventricular afterload and caused right ventricular hypertrophy and failure. 6-mercaptopurine did not improve right ventricular function nor reduce right ventricular remodelling in both prevention and reversal studies compared with placebo-treated rats.. Treatment with 6-mercaptopurine did not have any beneficial or detrimental effects on right ventricular function or remodelling. Our data suggest that treatment of pulmonary arterial hypertension with 6-mercaptopurine is not harmful to the failing right ventricle.

Topics: Animals; Apoptosis; Blood Pressure; Disease Models, Animal; Heart Failure; Heart Ventricles; Hemodynamics; Hypertension, Pulmonary; Male; Mercaptopurine; Rats, Wistar; Ventricular Function, Right; Ventricular Remodeling

Pulmonary arterial hypertension (PAH) is a progressive fatal disease characterised by abnormal remodelling of pulmonary vessels, leading to increased vascular resistance and right ventricle failure. This abnormal vascular remodelling is associated with endothelial cell dysfunction, increased proliferation of smooth muscle cells, inflammation and impaired bone morphogenetic protein (BMP) signalling. Orphan nuclear receptor Nur77 is a key regulator of proliferation and inflammation in vascular cells, but its role in impaired BMP signalling and vascular remodelling in PAH is unknown.We hypothesised that activation of Nur77 by 6-mercaptopurine (6-MP) would improve PAH by inhibiting endothelial cell dysfunction and vascular remodelling.Nur77 expression is decreased in cultured pulmonary microvascular endothelial cells (MVECs) and lungs of PAH patients. Nur77 significantly increased BMP signalling and strongly decreased proliferation and inflammation in MVECs. In addition, conditioned medium from PAH MVECs overexpressing Nur77 inhibited the growth of healthy smooth muscle cells. Pharmacological activation of Nur77 by 6-MP markedly restored MVEC function by normalising proliferation, inflammation and BMP signalling. Finally, 6-MP prevented and reversed abnormal vascular remodelling and right ventricle hypertrophy in the Sugen/hypoxia rat model of severe angioproliferative PAH.Our data demonstrate that Nur77 is a critical modulator in PAH by inhibiting vascular remodelling and increasing BMP signalling, and activation of Nur77 could be a promising option for the treatment of PAH.

Topics: Animals; Bone Morphogenetic Proteins; Cell Proliferation; Culture Media, Conditioned; Disease Models, Animal; Disease Progression; Endothelial Cells; HEK293 Cells; Humans; Hypertension, Pulmonary; Inflammation; Lung; Male; Mercaptopurine; Microcirculation; Nuclear Receptor Subfamily 4, Group A, Member 1; Rats; Rats, Sprague-Dawley; Signal Transduction; Vascular Remodeling

Relapsed acute lymphoblastic leukaemia (ALL) is associated with resistance to chemotherapy and poor prognosis. Gain-of-function mutations in the 5'-nucleotidase, cytosolic II (NT5C2) gene induce resistance to 6-mercaptopurine and are selectively present in relapsed ALL. Yet, the mechanisms involved in NT5C2 mutation-driven clonal evolution during the initiation of leukaemia, disease progression and relapse remain unknown. Here we use a conditional-and-inducible leukaemia model to demonstrate that expression of NT5C2(R367Q), a highly prevalent relapsed-ALL NT5C2 mutation, induces resistance to chemotherapy with 6-mercaptopurine at the cost of impaired leukaemia cell growth and leukaemia-initiating cell activity. The loss-of-fitness phenotype of NT5C2

Topics: 5'-Nucleotidase; Animals; Cell Proliferation; Clonal Evolution; Disease Models, Animal; Drug Resistance, Neoplasm; Female; Gain of Function Mutation; Guanosine; HEK293 Cells; Humans; IMP Dehydrogenase; Male; Mercaptopurine; Mice; Mutation; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Purines; Receptor, Notch1; Recurrence; Xenograft Model Antitumor Assays

Elevated activity of mTOR is associated with poor prognosis and higher incidence of relapse in B-cell acute lymphoblastic leukemia (B-ALL). Thus, ongoing clinical trials are testing mTOR inhibitors in combination with chemotherapy in B-ALL. However, the combination of mTOR inhibitors with standard of care chemotherapy drugs has not been studied extensively in high-risk B-ALL subtypes. Therefore, we tested whether mTOR inhibition can augment the efficacy of current chemotherapy agents in Ph

Topics: Animals; Antimetabolites, Antineoplastic; Cell Cycle; Cell Line, Tumor; Disease Models, Animal; DNA Damage; Drug Resistance, Neoplasm; Female; Humans; Male; Mechanistic Target of Rapamycin Complex 1; Mercaptopurine; Methotrexate; Mice; Mice, Knockout; Models, Biological; Philadelphia Chromosome; Precursor B-Cell Lymphoblastic Leukemia-Lymphoma; Protein Kinase Inhibitors; Xenograft Model Antitumor Assays

Upregulation of high-level toll-like receptors (TLRs) is observed in the serum of animals following experimental subarachnoid hemorrhage (SAH) and is highly related to SAH-induced early brain injury (EBI). The present study was of interest to examine the effect of 6-mercaptopurine (6-MP) on alternation of TLR-2, -3, and -4 in this model.. A rodent SAH model was used. Administration with 6-MP (0.5/1/2 mg/kg/d) was initiated 1 h after the induction of SAH via an osmotic minipump. Cerebral cortex was harvested to measure TLRs messenger RNA and protein (reverse transcription polymerase chain reaction [rt-PCR] and Western blot). Cerebral cortex was harvested for activated caspases (rt-PCR) measurement.. Cellular evaluation revealed increased neuronal nuclei(+) neurons with vacuolated nuclear and glial fibrillary acidic protein(+) astrocytes in the SAH group, but absent in the 6-MP treatment and healthy controls. The TLR-3 levels were not significantly increased in animals subject to SAH, compared with the controls (no SAH). The levels of TLR-2 and -4 in the SAH only and SAH plus vehicle groups were significantly elevated (P < 0.01), and treatment with 6-MP reduced TLR-2, -3 (at 2 mg/kg), and -4 (dose-dependently) protein expression following SAH. Likewise, the TLR-4 messenger RNA levels were also significantly reduced in the 6-MP (at 1 mg/kg and 2 mg/kg) groups. Cleaved caspase-3 and caspase-9a were reduced at 2-mg/kg 6-MP treatment group.. These results show that 6-MP attenuates the expression of TLR-2, -4, especially TLR-4, which play an antiapoptotic effect on SAH-induced EBI. This finding supported that through modulating TLRs, 6-MP can attenuate SAH-induced EBI. Those results offer credit to the neuroprotective effect of 6-MP.

Topics: Animals; Antigens, Nuclear; Antimetabolites; Brain Injuries; Caspase 3; Caspase 9; Cytokines; Disease Models, Animal; Drug Evaluation, Preclinical; Male; Mercaptopurine; Nerve Tissue Proteins; Proto-Oncogene Proteins c-bcl-2; Random Allocation; Rats, Sprague-Dawley; Subarachnoid Hemorrhage; Toll-Like Receptors

Leydig cells are crucial to the production of testosterone in males. It is unknown if the cancer chemotherapeutic drug, 6-mercaptopurine (6 MP), produces Leydig cell failure among adult survivors of childhood acute lymphoblastic leukemia. Moreover, it is not known whether Leydig cell failure is due to either a loss of cells or an impairment in their function. Herein, we show, in a subset of childhood cancer survivors, that Leydig cell failure is related to the dose of 6 MP. This was extended, in a murine model, to demonstrate that 6 MP exposure induced caspase 3 activation, and the loss of Leydig cells was independent of Bak and Bax activation. The death of these non-proliferating cells was triggered by 6 MP metabolism, requiring formation of both cytosolic reactive oxygen species and thiopurine nucleotide triphosphates. The thiopurine nucleotide triphosphates (with physiological amounts of dATP) uniquely activated the apoptosome. An ABC transporter (Abcc4/Mrp4) reduced the amount of thiopurines, thereby providing protection for Leydig cells. The studies reported here demonstrate that the apoptosome is uniquely activated by thiopurine nucleotides and suggest that 6 MP induced Leydig cell death is likely a cause of Leydig cell failure in some survivors of childhood cancer.

Topics: Animals; Antimetabolites, Antineoplastic; Apoptosis; Apoptosomes; Caspases; Cell Line, Tumor; Disease Models, Animal; Humans; Leydig Cells; Male; Mercaptopurine; Methotrexate; Mice, Transgenic; Multidrug Resistance-Associated Proteins; Reactive Oxygen Species

In aortic aneurysms the arterial vessel wall is dilated because of destruction of its integrity, which may lead to lethal vessel rupture. Chronic infiltration of inflammatory cells into the vessel wall is fundamental to aneurysm pathology. We aim to limit aneurysm growth by inhibition of inflammation and reducing endothelial cell (EC) activation with immunosuppressive drug azathioprine (Aza).. Aza and its metabolite 6-mercaptopurine have anti-inflammatory effects on leukocytes. We here demonstrate that treatment of ECs with 6-mercaptopurine inhibits cell activation as illustrated by reduced expression of interleukin-12, CCL5, CCL2, and vascular cell adhesion molecule-1 and inhibition of monocyte-EC adhesion. The underlying mechanism of 6-mercaptopurine involves suppression of GTPase Rac1 activation, resulting in reduced phosphorylation of c-Jun-terminal-N-kinase and c-Jun. Subsequently, the effect of Aza was investigated in aneurysm formation in the angiotensin II aneurysm mouse model in apolipoprotein E-deficient mice. We demonstrated that Aza decreases de novo aortic aneurysm formation from an average aneurysm severity score of 2.1 (control group) to 0.6 (Aza group), and that Aza effectively delays aorta pathology in a progression experiment, resulting in a reduced severity score from 2.8 to 1.7 in Aza-treated mice. In line with the in vitro observations, Aza-treated mice showed less c-Jun-terminal-N-kinase activation in ECs and reduced leukocyte influx in the aortic wall.. The immunosuppressive drug Aza has an anti-inflammatory effect and in ECs inhibits Rac1 and c-Jun-terminal-N-kinase activation, which may explain the protective effect of Aza in aneurysm development and, most importantly for clinical implications, aneurysm severity.

Topics: Angiotensin II; Animals; Anti-Inflammatory Agents; Aortic Aneurysm; Aortic Rupture; Apolipoproteins E; Azathioprine; Cell Line, Tumor; Coculture Techniques; Disease Models, Animal; Disease Progression; Endothelial Cells; Enzyme Activation; Human Umbilical Vein Endothelial Cells; Humans; Immunosuppressive Agents; Inflammation Mediators; JNK Mitogen-Activated Protein Kinases; Mercaptopurine; Mice; Mice, Knockout; Monocytes; Neuropeptides; Phosphorylation; Protein Kinase Inhibitors; rac1 GTP-Binding Protein; Signal Transduction

A very famous paper by Sam Pruzansky, published in 1969, was entitled "Not all dwarfed mandibles are alike". This is the topic of this paper: to describe the shape and discuss the possible pathogenesis of an extremely rare congenital dysplasia found in a unilaterally hypoplastic mandible, namely the isolated mandibular ramus.. A unique malformation of the lower jaw was found in more than 75 patients with developmental abnormalities of the mandible diagnosed and treated by the two authors in two different university hospitals over the last 40 years. We performed the following teratological experiments with laboratory rodents in order to try to understand the pathogenesis of this special dysplasia (and others): at first the normal development of the lower jaw was studied in rat and mouse foetuses. Then a variety of teratogenic drugs were applied to pregnant females and then the foetuses of these pregnancies were studied following Caesarian section.. One rat foetus was identified which presented the identical dysplasia that had been noted in the patient described here. The dam pregnant with this foetus had been given 25 mg/kg bodyweight of 6-mercaptopurine on day 12 of pregnancy. The explanation found for the pathogenesis of this anomaly was deducted from the scientific literature regarding normal development of the mandibular condyle.. The nucleus of the so-called secondary cartilage that will produce the ascending ramus (plus condyle and coronoid) is a separate growth centre which fuses a short time later with the dental bone which becomes the mandible proper by this fusion.

Topics: Animals; Antimetabolites; Autografts; Bone Diseases, Developmental; Bone Transplantation; Cartilage; Child, Preschool; Disease Models, Animal; Dysostoses; Female; Follow-Up Studies; Goldenhar Syndrome; Humans; Mandible; Mandibular Condyle; Mandibular Reconstruction; Mandibulofacial Dysostosis; Mercaptopurine; Mice; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Rats, Sprague-Dawley; Teratogens

S-allylthio-6-mercaptopurine and its ribose derivative were tested for anti-leukemic activity, using a human- mouse B-CLL model. The novel prodrugs contain two components, a purine analog, which interferes with DNA synthesis, and an S-allylthio, readily engaging in thiol-disulfide exchange reactions. The latter component targets the redox homeostasis which is more sensitive in leukemic cells, than in normal B-cells. Upon administration, the prodrug permeates cells, instantly reacts with free thiol, forming S-allyl mixed disulfides and releasing purine. Several cycles of thiol-disulfide exchange reactions occur, thus extending the duration of the prodrug effects. The concerted action of 2 components, as compared with purine alone, boosted in vitro apoptotis in B-CLL cells from 10% to 38%, and decreased in vivo engraftment of B-CLL from 30% to 0.7%.

Topics: Allyl Compounds; Animals; Antineoplastic Agents, Phytogenic; Apoptosis; B-Lymphocytes; Cell Membrane Permeability; Disease Models, Animal; Disulfides; DNA; Drug Synergism; Female; Humans; Leukemia, Lymphocytic, Chronic, B-Cell; Mercaptopurine; Mice; Mice, Inbred ICR; Oxidation-Reduction; Prodrugs; Sulfhydryl Compounds; Sulfinic Acids

Increased endothelin-1 (ET-1) production and diminished nitric oxide synthase (NOS) bioavailability has been observed in aneurysmal subarachnoid hemorrhage (SAH). The authors previously found that 6-mercaptopurine (6-mp) is effective in preventing and reversing arterial narrowing in a rodent SAH model. This present study is of interest to examine the effect of 6-mp on ET-1/endothelial nitric oxide synthase (eNOS) in this animal model.. A rodent double hemorrhage SAH model was employed. Animals were randomly assigned to six groups (sham, SAH only, vehicle, 0.5, 1.0 and 2 mg kg(-1) day(-1) 6-mp treatment). Monoclonal CD45 immunostaining was utilized to evaluate monocytes and microglia. The level of pro-inflammatory cytokines, such as IL-1, IL-6 and TNF-α(RT-PCR), and ET-1 (ELISA) was measured. The basilar arteries (BAs) were harvested and sliced, and their cross-sectional areas were determined. Radiolabeled NOS assay kit was applied to detect eNOS.. Morphologically, convolution of internal elastic lamina, endothelial cells distortion, and necrotic smooth muscle were prevalently present in the basilar artery of SAH groups, which was absent in the 1 and 2 mg kg(-1) day(-1) 6-mp plus SAH group or the healthy controls. Significant vasospasm was noted in the vehicle group (lumen patency, 54.6%, p ≤ 0.01 compared with the sham group), but it was less prominent in the 2 mg kg(-1) day(-1) 6-mp treatment group (lumen patency, 87.6%, p < 0.05). In addition, administration with 2 mg kg(-1) day(-1) 6-mp reduced cytokine levels by 11%, 47%, and 34% for IL-1, IL-6, and TNF-α, respectively, and increased ET-1 levels were found in all the animals subject to SAH (SAH only, SAH plus vehicle, SAH plus 0.5 and 1.0 mg kg(-1) day(-1) 6-mp) except in the 2 mg kg(-1) day(-1) 6-mp SAH group, when compared with the healthy controls (no SAH). Meanwhile, treatment with 6-mp did not induce the levels of expressed eNOS in BAs in the 6-mp groups (0.5, 1.0, and 2 mg kg(-1) day(-1) 6-mp plus SAH) when compared with that in the SAH groups (p > 0.1).. In summary, treatment with 6-mp decreased the release of pro-inflammatory cytokines and diminished experimental vasospasm. This study offered first evidence that 6-mp dose-dependently reduces the level of ET-1 in a NO-independent mechanism, which corresponds to its antivasospastic effect in the condition of chronic vasospasm.

Topics: Aneurysm, Ruptured; Animals; Chemotaxis; Connective Tissue; Cytokines; Disease Models, Animal; Dose-Response Relationship, Drug; Endothelin-1; Immunosuppressive Agents; Inflammation Mediators; Intracranial Aneurysm; Male; Mercaptopurine; Microglia; Muscle, Smooth, Vascular; Nitric Oxide; Nitric Oxide Synthase; Rats; Rats, Sprague-Dawley; Subarachnoid Hemorrhage; Vasospasm, Intracranial

Adhesion molecules, including intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin, are important inflammatory mediators which are elevated in the serum of patients following aneurysmal subarachnoid hemorrhage (SAH). The authors previously found that 6-mercaptopurine (6-mp) was effective in preventing and reversing arterial narrowing in a rodent SAH model. The present study was to examine whether levels of adhesion molecules were altered after treatment with 6-mp in this animal model.. Animals were each injected with autologous blood into the cisterna magna, and intraperitoneal treatment with 6-mp (2 mg/kg) was initiated 1 h before (prevention) or later (treatment). The compound was subsequently administered at 24 and 48 h post-SAH. Blood samples were collected at 72 h post-SAH to measure ICAM-1, VCAM-1, and E-selectin levels. The basilar arteries were harvested and sliced, and their cross-sectional areas were measured. Morphologically, convolution of the internal elastic lamina, distorted endothelial wall, and myonecrosis of the smooth muscle were prominently observed in the SAH only and vehicle-treated SAH groups, but not in the 6-mp-treated SAH group or in healthy controls. No significant differences were found in the levels of VCAM-1 among all groups. However, the levels of E-selectin were increased in all animals subjected to SAH (SAH only and SAH plus vehicle groups) compared with healthy controls (no SAH), but not in the 6-mp group (SAH plus 6-mp treatment and preventive treatment with 6-mp).Likewise, the levels of ICAM-1 in the SAH only and SAH plus vehicle groups were significantly elevated (p < 0.001), and pretreatment and treatment with 6-mp reduced ICAM-1 to control levels.. These results show that ICAM-1 and E-selectin may play a role in mediating SAH-induced vasospasm and that a reduction of both adhesive molecules after SAH may partly contribute to the antispastic effect of 6-mp.

Topics: Animals; Antimetabolites; Basilar Artery; Cell Adhesion Molecules; Cerebral Arteries; Disease Models, Animal; E-Selectin; Inflammation Mediators; Intercellular Adhesion Molecule-1; Male; Mercaptopurine; Rats; Rats, Sprague-Dawley; Subarachnoid Hemorrhage; Treatment Outcome; Up-Regulation; Vascular Cell Adhesion Molecule-1; Vasodilation; Vasospasm, Intracranial

6-Mercaptopurine (6-MP), the active metabolite of the immunosuppressive prodrug azathioprine, is commonly used in autoimmune diseases and transplant recipients, who are at high risk for cardiovascular disease. Here, we aimed to gain knowledge on the action of 6-MP in atherosclerosis, with a focus on monocytes and macrophages.. We demonstrate that 6-MP induces apoptosis of THP-1 monocytes, involving decreased expression of the intrinsic antiapoptotic factors B-cell CLL/Lymphoma-2 (Bcl-2) and Bcl2-like 1 (Bcl-x(L)). In addition, we show that 6-MP decreases expression of the monocyte adhesion molecules platelet endothelial adhesion molecule-1 (PECAM-1) and very late antigen-4 (VLA-4) and inhibits monocyte adhesion. Screening of a panel of cytokines relevant to atherosclerosis revealed that 6-MP robustly inhibits monocyte chemoattractant chemokine-1 (MCP-1) expression in macrophages stimulated with lipopolysaccharide (LPS). Finally, local delivery of 6-MP to the vessel wall, using a drug-eluting cuff, attenuates atherosclerosis in hypercholesterolemic apolipoprotein E*3-Leiden transgenic mice (P<0.05). In line with our in vitro data, this inhibition of atherosclerosis by 6-MP was accompanied with decreased lesion monocyte chemoattractant chemokine-1 levels, enhanced vascular apoptosis, and reduced macrophage content.. We report novel, previously unrecognized atheroprotective actions of 6-MP in cultured monocytes/macrophages and in a mouse model of atherosclerosis, providing further insight into the effect of the immunosuppressive drug azathioprine in atherosclerosis.

Topics: Animals; Apolipoprotein E3; Apoptosis; Atherosclerosis; bcl-X Protein; Cell Adhesion; Cells, Cultured; Chemokine CCL2; Chemotaxis; Disease Models, Animal; Dose-Response Relationship, Drug; Humans; Immunosuppressive Agents; Inflammation Mediators; Integrin alpha4beta1; Macrophages; Male; Mercaptopurine; Mice; Mice, Inbred C57BL; Mice, Transgenic; Monocytes; Platelet Endothelial Cell Adhesion Molecule-1; Proto-Oncogene Proteins c-bcl-2; Time Factors

A bursting cascade of inflammation imposes progressive neurological deterioration after experimental stroke has been demonstrated. In our study, 6-mercaptopurine (6-mp) has been successful in alleviating cerebral infarct in a rodent permanent middle cerebral artery occlusion (pMCAO) model. The present study was aimed to examine the effect of 6-mp on cytokine levels in experimental stroke.. The rodent pMCAO model was employed. A dose of 2 mg/kg 6-mp or vehicle (0.1 mol/L PBS) was administered intraperitoneally 30 min after the induction of pMCAO. Neurological score, serum, and cerebrospinal fluid (CSF) cytokines such as IL-1beta, IL-6, and TNF-alpha and infarct volume were determined 48 h after pMCAO.. Cerebral infarction volume was significantly decreased in animals treated with 6-mp (74.3%, p < 0.01), and the ratio of tissue edema was also decreased in 6-mp-treated groups (71%). Animals receiving 6-mp thus showed a significant decrease in IL-1 and TNF-alpha (18/43% and 48/64% in CSF/serum, respectively) when compared with the pMCAO groups (p < 0.01).. This study demonstrates that 6-mp interposes the production of IL-1 and TNF-alpha in CSF and serum, attenuates ischemic brain injury, and thus alleviates neurological deficits in the pMCAO animals. These findings also offer first evidence that 6-mp may attenuate TNF-alpha-related neuron apoptosis and also support the notion that 6-mp and other anti-inflammatory agents could potentially have therapeutic uses in cases of cerebral infarct.

Topics: Animals; Apoptosis; Biomarkers; Brain Infarction; Disease Models, Animal; Down-Regulation; Immunosuppressive Agents; Infarction, Middle Cerebral Artery; Interleukin-1; Male; Mercaptopurine; Nerve Degeneration; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Treatment Outcome; Tumor Necrosis Factor-alpha

Restenosis is a common complication after percutaneous coronary interventions and is characterized by excessive proliferation of vascular smooth muscle cells (SMCs). We have shown that the nuclear receptor Nur77 protects against SMC-rich lesion formation, and it has been demonstrated that 6-mercaptopurine (6-MP) enhances Nur77 activity. We hypothesized that 6-MP inhibits neointima formation through activation of Nur77.. It is demonstrated that 6-MP increases Nur77 activity in cultured SMCs, which results in reduced [3H]thymidine incorporation, whereas Nur77 small interfering RNA knockdown partially restores DNA synthesis. Furthermore, we studied the effect of 6-MP in a murine model of cuff-induced neointima formation. Nur77 mRNA is upregulated in cuffed arteries, with optimal expression after 6 hours and elevated expression up to 7 days after vascular injury. Local perivascular delivery of 6-MP with a drug-eluting cuff significantly inhibits neointima formation in wild-type mice. Locally applied 6-MP does not affect inflammatory responses or apoptosis but inhibits expression of proliferating cell nuclear antigen and enhances protein levels of the cell-cycle inhibitor p27(Kip1) in the vessel wall. An even stronger inhibition of neointima formation in response to local 6-MP delivery was observed in transgenic mice that overexpressed Nur77. In contrast, 6-MP does not alter lesion formation in transgenic mice that overexpress a dominant-negative variant of Nur77 in arterial SMCs, which provides evidence for the involvement of Nur77-like factors.. Enhancement of the activity of Nur77 by 6-MP protects against excessive SMC proliferation and SMC-rich neointima formation. We propose that activation of the nuclear receptor Nur77 is a rational approach to treating in-stent restenosis.

Topics: Animals; Antimetabolites, Antineoplastic; Apoptosis; Cell Division; Cells, Cultured; Coronary Restenosis; Disease Models, Animal; DNA-Binding Proteins; Drug Implants; Femoral Artery; Humans; Male; Mercaptopurine; Mice; Mice, Inbred Strains; Mice, Transgenic; Muscle, Smooth, Vascular; Nuclear Receptor Subfamily 4, Group A, Member 1; Receptors, Cytoplasmic and Nuclear; Receptors, Steroid; RNA, Messenger; RNA, Small Interfering; Transcription Factors; Tunica Intima; Umbilical Arteries

Controlled mechanical ventilation (CMV) has been shown to result in elevated diaphragmatic proteolysis and atrophy together with diaphragmatic contractile dysfunction.. To test whether administration of leupeptin, an inhibitor of lysosomal proteases and calpain, concomitantly with 24 hours of CMV, would protect the diaphragm from the deleterious effects of mechanical ventilation.. Rats were assigned to either a control group or 24 hours of CMV; animals in the ventilation group received either a single intramuscular injection of saline or 15 mg/kg of the protease inhibitor, leupeptin.. Compared with control animals, mechanical ventilation resulted in a significant reduction of the in vitro diaphragm-specific force production at all stimulation frequencies. Leupeptin completely prevented this reduction in force generation. Atrophy of type IIx/b fibers was present after CMV, but not after treatment with leupeptin. Cathepsin B and calpain activities were significantly higher after CMV compared with the other groups; this was abolished by treatment with leupeptin. Significant inverse correlations were found between diaphragmatic force generation and cathepsin B and calpain activity, and illustrate the deleterious role of proteolysis in diminishing diaphragmatic force production after prolonged CMV.. Administration of the protease inhibitor leupeptin concomitantly with mechanical ventilation completely prevented ventilation-induced diaphragmatic contractile dysfunction and atrophy.

Topics: Animals; Blotting, Western; Calpain; Cathepsin B; Diaphragm; Disease Models, Animal; Fluorometry; Male; Mercaptopurine; Muscle Contraction; Muscular Diseases; Nucleic Acid Synthesis Inhibitors; Rats; Rats, Wistar; Respiration, Artificial; Treatment Outcome

Azathioprine [Imuran; 6-[(1-methyl-4-nitro-1H-imidazol-5-yl)thio]-1H-purine] is a widely used immunosuppressive and antiarthritic drug. For the sake of comparison, the riboside, the 2'-deoxyriboside, and the arabinoside of azathioprine and its 2-amino congener, thiamiprine, were prepared by an enzymatic method. In vitro, the cytotoxicities of these aglycons and their nucleosides were similar (ED50 = 0.8-2 microM), except for the arabinosides, which were nontoxic (ED50 greater than 100 microM). In vivo, their activities were compared in the rat adjuvant arthritis model. The ribosides and 2'-deoxyribosides were less potent than their corresponding aglycons. The safety indexes of these nucleosides were comparable to those of the corresponding aglycons except for the 2'-deoxyriboside of azathioprine, which had an appreciably lower safety index than did azathioprine. Both arabinosides were inactive and nontoxic. All of the aglycons tested (6-mercaptopurine, azathioprine, 6-thioguanine, and thiamiprine) were of similar potency. However, azathioprine had a more favorable therapeutic index than did 6-mercaptopurine. Similarly, thiamiprine was safer than was 6-thioguanine. In this model, the S-(1-methyl-4-nitro-1H-imidazol-5-yl) moiety imparted greater safety to these thiopurines by decreasing toxicity but not affecting potency.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Arthritis, Experimental; Azathioprine; Cell Survival; Cells, Cultured; Chemical Phenomena; Chemistry; Disease Models, Animal; Female; Humans; Nucleosides; Rats

Acute glomerulonephritis characterized by proteinuria, hypoalbuminemia and leukocytosis was induced in mice by repeated intraperitoneal injections of calf serum (1 ml/mouse X 10). In mice treated with calf serum, hypercellularity, karyorrhexis, expansion of the mesangium and hyalinosis in the glomeruli were observed by light microscopy. Furthermore, circulating immune complexes were detected in the serum, and deposits of mouse IgG and C3 on the basement membranes of the glomeruli were demonstrated immunohistochemically. Oral administration of cyclophosphamide or 6-mercaptopurine at a dose of 20 mg/kg/day significantly suppressed the development of this nephritis. Dexamethasone (0.5 mg/kg/day) caused moderate inhibition of the nephritic changes. These results suggest that this experimental model may be useful for evaluation of anti-nephritic drugs.

Topics: Animals; Anti-Inflammatory Agents; Blood Cell Count; Body Weight; Cyclophosphamide; Dexamethasone; Disease Models, Animal; Fluorescent Antibody Technique; Immunochemistry; Indomethacin; Kidney Glomerulus; Male; Mercaptopurine; Mice; Mice, Inbred ICR; Nephritis; Organ Size; Serum Sickness

The experimental glomerulonephritis was caused by the intravenous injection of a subnephrotoxic dose of nephrotoxic serum in the mice which had been previously immunized with rabbit IgG and complete Freund's adjuvant. The elevation of urinary protein excretion, serum blood urea nitrogen level and cholesterol level and the decrease of serum albumin level were demonstrated in nephritic mice. Hypercellularity in the glomerulus and hyalinosis in tubular system were observed in histopathological studies. The clinical signs in this experimental model were similar to human glomerulonephritis. In a transfer experiment, sensitized lymphocytes against rabbit IgG were necessary for the onset of disease. Clear remission of glomerulonephritis was indicated by the administration of cyclophosphamide or 6-mercaptopurine. Glucocorticoids showed moderate suppression of the development of this nephritis. These evidences suggest that this experimental model is useful for the immunopharmacological research of glomerulonephritis.

Topics: Animals; Cyclophosphamide; Dexamethasone; Disease Models, Animal; Glomerulonephritis; Hydrocortisone; Male; Mercaptopurine; Mice; Mice, Inbred C57BL; Time Factors

Rats with experimental allergic encephalomyelitis (EAE) induced with myelin or spinal cord show decreases in the content of sulphatides and cerebrosides and increases in the level of esterified cholesterol in the CNS. In this work it is shown that brain sulphatide changes can be obtained by injection of mixtures containing glycosphingolipids. Alterations in the content of cerebrosides occur when the injection mixture contains cerebrosides. The alterations of sulphatides and cholesterol ester induced by injection of spinal cord could be suppressed by treatment with immunosuppressive drugs (dexamethasone, cyclophosphamide and 6-mercaptopurine) able to prevent clinical signs of EAE.

Topics: Animals; Brain; Cerebrosides; Cholesterol Esters; Cyclophosphamide; Dexamethasone; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Female; Immunosuppressive Agents; Lipid Metabolism; Male; Mercaptopurine; Myelin Sheath; Rats; Spinal Cord; Sulfoglycosphingolipids

Effectiveness of selected anti-inflammatory drugs on the experimental model of uveitis was evaluated. Studies on the biochemical parameters of inflammation in the aqueous humor and biomicroscopic evaluation of the clinical condition of the anterior chamber of the eye, carried out in the therapy course, allowed to establish the following order of the studied drugs, according to their therapeutical effectiveness (from the most effective): indomethacin greater than ibuprofen greater than hydrocortizone greater than 6-mercaptopurine.

Topics: Animals; Anti-Inflammatory Agents; Aqueous Humor; Disease Models, Animal; Female; Hydrocortisone; Ibuprofen; Indomethacin; Male; Mercaptopurine; Orosomucoid; Peptide Hydrolases; Prostaglandins; Proteins; Rabbits; Sialic Acids; Uveitis, Anterior

An egg albumin uveitis of the Arthus active type was developed in the rabbit. The experimental conditions were investigated in detail with regard to the following factors: influence of the number of sensitizing injections on serum antibody production, length of the recovery period which elapsed between sensitization and challenge, and influence of the size of the challenging dose on the severity of the inflammatory response. To develop the procedure optimally, emphasis was given to criteria of evaluation. Refractive index, protein and immunoglobulin assays in the aqueous humor of inflamed eyes were significantly correlated. These objective measures were considered more reliable than arbitrary grading systems. In addition, supportive histopathologic observations have been made in rabbit eyes. The above studies led to a reproducible model of uveitis in which drugs were tested topically. Dexamethasone phosphate in solution and indomethacin in suspension were effective in a dose-related manner. 6-Mercaptopurine did not demonstrate a useful anti-inflammatory effect.

Topics: Administration, Topical; Animals; Antibodies; Aqueous Humor; Arthus Reaction; Dexamethasone; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Eye Proteins; Female; Immunoglobulins; Indomethacin; Male; Mercaptopurine; Ovalbumin; Rabbits; Uveitis

Topics: Abnormalities, Drug-Induced; Animals; Bromodeoxyuridine; Disease Models, Animal; Ectromelia; Forelimb; Gestational Age; Mercaptopurine; Mice; Mice, Inbred Strains; Organ Culture Techniques; Syndactyly

Topics: Adrenal Cortex Hormones; Alkylating Agents; Animals; Anti-Inflammatory Agents; Capillaries; Cyclophosphamide; Disease Models, Animal; Female; Folic Acid Antagonists; Immunosuppressive Agents; Male; Mercaptopurine; Mice; Mice, Inbred Strains; Purines; Skin Diseases; Vasodilator Agents

Topics: Animals; Carbon Tetrachloride Poisoning; Disease Models, Animal; Hydrocortisone; Immunosuppressive Agents; Liver; Male; Mercaptopurine; Necrosis; Rabbits

Topics: Alkylating Agents; Animals; Antineoplastic Agents; Cyclophosphamide; Diethylamines; Disease Models, Animal; Drug Therapy, Combination; Ethylenediamines; Fluorenes; Fluorouracil; Interferon Inducers; Leukemia L1210; Leukemia, Experimental; Leukemia, Lymphoid; Male; Mercaptopurine; Methotrexate; Mice; Mice, Inbred BALB C; Mice, Inbred DBA; Prednisolone; Thioxanthenes; Vincristine

Topics: Aminopyrine; Animals; Anti-Inflammatory Agents; Arthritis, Rheumatoid; Azathioprine; Biological Assay; Cyclophosphamide; Dexamethasone; Disease Models, Animal; Drug Evaluation, Preclinical; Freund's Adjuvant; Hexobarbital; Humans; Hydroxylation; Inflammation; Irritants; Male; Mercaptopurine; Microsomes, Liver; Rats; Rats, Inbred Lew; Sleep; Time Factors

Topics: Alkaline Phosphatase; Animals; Cell Transformation, Neoplastic; Cyclophosphamide; Disease Models, Animal; Esterases; Injections, Intraperitoneal; Injections, Intravenous; Injections, Subcutaneous; Leukemia, Experimental; Liver; Lymph Nodes; Mercaptopurine; Methotrexate; Neoplasm Transplantation; Nitrosourea Compounds; Peroxidases; Rats; Rats, Inbred Strains; Spleen; Transplantation, Homologous; Vincristine

Topics: Amides; Animals; Antineoplastic Agents; Azacitidine; Cyclic P-Oxides; Cyclophosphamide; Cytarabine; Disease Models, Animal; Drug Combinations; Female; Imidazoles; Lymphoma; Male; Mercaptopurine; Methotrexate; Mice; Mice, Inbred Strains; Oxazines; Prednisone; Remission, Spontaneous; Time Factors; Triazenes; Vincristine

Topics: 5-Hydroxytryptophan; Amphetamine; Anilides; Animals; Azathioprine; Body Weight; Chlorpheniramine; Cinnamates; Cyclophosphamide; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Female; Fenclonine; Immunosuppressive Agents; Mercaptopurine; Methylamines; Methysergide; Paralysis; Rats; Reserpine; Serotonin Antagonists; Tetrabenazine; Time Factors; Tranylcypromine

Topics: Animals; Breast Neoplasms; Carcinoma; Cell Transformation, Neoplastic; Cyclophosphamide; Disease Models, Animal; DNA Replication; Female; Humans; Leukemia; Lymph Nodes; Mercaptopurine; Mice; Neoplasm Metastasis; Sarcoma

Topics: Aminopyrine; Animals; Anti-Inflammatory Agents; Bis-Trimethylammonium Compounds; Cortisone; Cyclophosphamide; Dexamethasone; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Female; Flumethasone; Freund's Adjuvant; Glucocorticoids; Guanethidine; Guinea Pigs; Hydrocortisone; Lethal Dose 50; Male; Mercaptopurine; Paramethasone; Phenylbutazone; Prednisolone; Prednisone; Rats; Sodium Salicylate; Spinal Cord

Topics: Animals; Antineoplastic Agents; Asparaginase; Blood Platelets; Bone Marrow Cells; Cyclophosphamide; Cytarabine; Daunorubicin; Disease Models, Animal; Drug Synergism; Hemorrhage; Humans; Infections; Leukemia L1210; Leukemia, Lymphoid; Leukemia, Myeloid, Acute; Mercaptopurine; Methotrexate; Mice; Prednisone; Prognosis; Thrombocytopenia; Vincristine

Topics: Adolescent; Animals; Antineoplastic Agents; Asparaginase; Bone Marrow; Bone Marrow Cells; Child; Cytarabine; Daunorubicin; Disease Models, Animal; Humans; Leukemia, Lymphoid; Leukemia, Myeloid; Mercaptopurine; Methotrexate; Mice; Remission, Spontaneous; Vincristine

Topics: Animals; Antineoplastic Agents; Cyclophosphamide; Cytarabine; Dactinomycin; Daunorubicin; Disease Models, Animal; DNA, Neoplasm; Fluorouracil; Half-Life; Hydroxyurea; In Vitro Techniques; Kinetics; Leukemia L1210; Mercaptopurine; Methotrexate; Mice; Mitosis; Nitrosourea Compounds; Thiosemicarbazones

Topics: Anaphylaxis; Animals; Antibiotics, Antineoplastic; Cortisone; Depression, Chemical; Disease Models, Animal; Flavonoids; Guinea Pigs; Immune Sera; Injections, Intraperitoneal; Injections, Intravenous; Male; Mercaptopurine; Oxytetracycline; Time Factors

Topics: Animals; Disease Models, Animal; Drug Synergism; Immunization, Passive; Immunosuppressive Agents; Leukemia L1210; Mercaptopurine; Mice; Sarcoma 180

Topics: Animals; Antibody Formation; Depression, Chemical; Disease Models, Animal; Humans; Hypersensitivity, Delayed; Mercaptopurine; Rabbits