Pharmacology of a new cyclic nucleotide phosphodiesterase type 4 inhibitor,V11294

V11294 is a new cyclic nucleotide phosphodiesterase type 4 (PDE4) inhibitor of the rolipram class. In this report we present the pharmacological profile of V11294. V11294 inhibited PDE4 isolated from human lung with IC(50) 405 nM, compared to 3700 nM for rolipram. In contrast, V11294 inhibition of human PDE3 and PDE5 occurred only at concentrations greater than 100,000 nM. Like rolipram, V11294 inhibited PDE4D more potently than other PDE4 subtypes. V11294, when incubated with human anticoagulated whole blood in vitro, or administered to mice, caused increased cAMP concentration, consistent with inhibition of PDE4. V11294 inhibited lectin-induced proliferation and lipopolysaccharide-induced TNFalpha synthesis by human adherent monocytes in vitro and inhibited lipopolysaccharide-induced TNFalpha synthesis in mice. V11294 caused relaxation of guinea pig isolated trachea and inhibited allergen-induced bronchoconstriction and eosinophilia in guinea pigs at doses of 1 and 3 mg/kg, p.o. In ferrets, V11294 was not emetogenic at doses up to 30 mg/kg, p.o., despite plasma concentration reaching 10-fold the IC(50) for PDE4. In contrast, rolipram induced severe retching and vomiting at 10 mg/kg, p.o. In conclusion, V11294 is an orally active PDE4 inhibitor that exhibits antiinflammatory activity in vitro, and in vivo at doses that are not emetogenic.     

Lack of involvement of type 7 phosphodiesterase in an experimental model of asthma

Type 7 phosphodiesterases (PDE7) are responsible for the decrease of intracellular cyclic AMP (cAMP) in many cells involved in allergic asthma by suppressing their potential to respond to many activating stimuli. The elevation of intracellular cAMP has been associated with immunosuppressive and anti-inflammatory activities and represents a potential treatment of asthma. Our aim was to evaluate the impact of the deletion of the murine phosphodiesterase (PDE)7B gene and then to evaluate the efficacy of a newly described selective PDE7A and -B inhibitor on an ovalbumin (OVA)-induced airway inflammation and airway hyperreactivity (AHR) model in mice. Inflammation was determined 72 h after single OVA challenge or 24 h after multiple challenges by the relative cell influx and cytokine content in bronchoalveolar lavage fluid. AHR and immunoglobulin E levels in serum were determined after multiple challenges. For the first time, we have demonstrated that the deletion of the PDE7B gene or the pharmacological inhibition of PDE7A and -B had no effect on all the parameters looked at in this model. These results highlight the absence of any implication of the PDE7 enzyme in our model.     

Involvement of MMP-12 and phosphodiesterase type 4 in cigarette smoke-induced inflammation in mice.

The aim of the present study was to characterise a mouse model of airways inflammation induced by cigarette smoke and to compare it with a lipopolysaccharide (LPS) model with regards to the efficacy of a PDE4 inhibitor (cilomilast), a corticosteroid (dexamethasone) and macrophage metalloelastase (MMP)-12 gene deletion. Cigarette smoke exposure for 3 days induced a time-dependent airway neutrophilia associated with an increased level of keratinocyte-derived chemokine (KC), macrophage inflammatory protein (MIP)-2, MIP-1alpha and MMP-9 in the bronchoalveolar lavage (BAL). LPS exposure also induced an increase in the number of neutrophils in BAL. Studies in MMP-12-/- mice showed that in contrast to the smoking model, MMP-12 did not have a critical role in LPS-induced inflammation. Both cilomilast and dexamethasone blocked LPS-induced neutrophilia in a dose-dependent manner. Cilomilast inhibited cigarette smoke-induced neutrophilia and MIP-1alpha, but only 10 mg.kg(-1) of dexamethasone was effective. Both anti-inflammatory treatments had no effect on the levels of KC and MIP-2 in the BAL. Although the inflammatory response was very similar in the smoking model and LPS, the pharmacological modulation and the MMP-12 gene deletion highlighted the differences in the mechanisms involved. Furthermore, the cigarette smoke model seemed to better represent the situation described in chronic obstructive pulmonary disease patients. In conclusion, these differences underline the importance of using an acute smoke-exposure model to investigate potential new treatments for chronic obstructive pulmonary disease.     

Antiremodeling effects of iloprost and the dual-selective phosphodiesterase 3/4 inhibitor tolafentrine in chronic experimental pulmonary hypertension

Severe pulmonary hypertension is a disabling disease with high mortality. We investigated acute and chronic effects of iloprost, a long-acting prostacyclin analogue, and the dual-selective phosphodiesterase 3/4 inhibitor tolafentrine in monocrotaline-induced pulmonary hypertension in rats. Twenty-eight and 42 days after administration of the alkaloid, right ventricular systolic pressure increased from 25.8+/-2.0 to 62.9+/-3.4 and 70.5+/-7.4 mm Hg, with concomitant decline in cardiac index, central venous oxygen saturation, and arterial oxygenation. Marked right heart hypertrophy was demonstrated by the strongly elevated ratio of right ventricle/left ventricle plus septum weight, and massive thickening of the precapillary artery smooth muscle layer was shown histologically. Western blot analysis demonstrated increased levels of matrix metalloproteinases (MMPs) -2 and -9 and increased gelatinolytic activities in isolated pulmonary arteries. In these animals, both intravenous iloprost and tolafentrine displayed characteristic features of pulmonary vasodilators. When chronically infused from days 14 to 28, both agents significantly attenuated all monocrotaline-induced hemodynamic and gas exchange abnormalities as well as right heart hypertrophy. Full normalization of all variables including right ventricle size was achieved on combined administration of both agents during this period. This was also true for MMP-2 and MMP-9 expression and activity. Moreover, when iloprost plus tolafentrine was used for late therapeutic intervention, with infusion from days 28 to 42 after full establishment of severe pulmonary hypertension and cor pulmonale, hemodynamic, gas exchange, and cardiac and pulmonary vascular remodeling changes were significantly reversed. We conclude that the combined administration of iloprost and a dual-selective phosphodiesterase 3/4 inhibitor prevents and reverses the development of pulmonary hypertension and cor pulmonale in response to monocrotaline in rats. This regimen may therefore offer a possible antiremodeling therapy in severe pulmonary hypertension.     

Role of hepatocyte growth factor in endothelial regulation: prevention of high D-glucose-induced endothelial cell death by prostaglandins and phosphodiesterase type 3 inhibitor

Summary Injury of endothelial cells (EC) has been postulated as the initial trigger of the progression of atherosclerosis in patients with diabetes mellitus. We previously reported that decrease in a novel endothelium-specific growth factor, hepatocyte growth factor (HGF), by high d-glucose might be a trigger of endothelial injury. However, the physiological role of the local vascular HGF system has not yet been clarified. To investigate the role of HGF in endothelial injury, we initially examined the effects of HGF on endothelial injury induced by serum deprivation. Decrease in EC number by serum deprivation was significantly attenuated by addition of HGF as well as recombinant basic fibroblast growth factor, whereas vascular endothelial growth factor showed no effect. Apoptotic changes in EC induced by serum deprivation were also significantly attenuated by addition of HGF (p < 0.01). Given the protective action of HGF, we next studied the physiological role of local HGF production in endothelial regulation. We focused on the protective actions of prostaglandin (PG) I₂, PGE and a phosphodiesterase type 3 inhibitor (cilostazol) on endothelial injury by high glucose, since these agents are widely used in the treatment of peripheral arterial disease which is frequently observed in diabetic patients. Treatment of human aortic EC with PGE₁, PGE₂, and a PGI₂ analogue (beraprost sodium) as well as cilostazol stimulated EC growth. HGF concentration in conditioned medium from EC treated with PGE₁, PGE₂ or PGI₂ analogue as well as cilostazol was significantly higher than that with vehicle (p < 0.01). Interestingly, treatment with PGI₂ analogue or cilostazol attenuated high d-glucose-induced EC death, which was abolished by neutralizing anti-HGF antibody. Moreover, decreased local HGF production by high d-glucose was also significantly attenuated by PGI₂ analogue or cilostazol. Finally, we tested the effects of PGE, PGI₂ analogue and cilostazol on local HGF production in human aortic vascular smooth muscle cells (VSMC). Although high d-glucose treatment resulted in a significant increase in VSMC number, PGI₂ analogue and/or cilostazol treatment had no effects on VSMC growth. However, the decrease in local HGF production by high d-glucose was significantly attenuated by addition of PGI₂ analogue or cilostazol. Overall, this study demonstrated that treatment with PGE, PGI₂ analogue or cilostazol prevented aortic EC death induced by high d-glucose, probably through the activation of local HGF production. Increased local vascular HGF production by prostaglandins and cilostazol may prevent endothelial injury, potentially resulting in the improvement of peripheral arterial disease. [Diabetologia (1997) 40: 1053–1061] Received: 17 February 1997 and in revised form: 7 May 1997     

己酮可可碱预防NOD鼠1型糖尿病的机理研究

目的 探讨己酮可可碱（Pentoxifylline,PTX)对非肥胖糖尿病（NOD）小鼠1型糖尿病发病率，胰岛素的影响及其机制。方法 采用动物模型NOD鼠，注射环磷酰胺（CP）加速其发病。给PTX药物后计算糖尿病发病率，HE染色观察胰岛炎，并用逆转录（RT）PCR法检测脾细胞干扰素γ（IFN－γ），肿瘤坏死因子α（TNF－α），白介素10（IL－10）mRNA的表达。结果 PTX组糖尿病发生率（30．00％）明显低于对照组（67．86％）（P＜0．1）；胰岛炎程度也明显减轻（P＜0．001）；脾细胞IFN－γ，TNF－αmRNA的表达较对照组明显降低（P＜0．05），IL－10mRNA的表达无明显改变。结论 PTX可预防NOD鼠发生糖尿病，其机制可能与纠正Th1与Th2型细胞因子比例失衡有关。     

Effect of the phosphodiesterase 4 inhibitor roflumilast on glucose metabolism in patients with treatment-naive, newly diagnosed type 2 diabetes mellitus

Context: The phosphodiesterase 4 inhibitor roflumilast is a first-in-class antiinflammatory treatment for severe chronic obstructive pulmonary disease (COPD) associated with chronic bronchitis and a history of frequent exacerbations. In previous clinical studies, a transient and reversible weight decrease was reported with roflumilast, suggesting the systemic actions of this drug may impact metabolism. Objective: Our objective was to investigate the effects of roflumilast on glucose homeostasis and body weight. Design and Setting: We conducted a 12-wk, randomized, double-blind, placebo-controlled multicenter study with outpatients. Patients: Patients (n = 205) with newly diagnosed type 2 diabetes mellitus (DM2) but without COPD were included in the study. Interventions: Roflumilast 500 μg or placebo was administered once daily. Primary Outcome: We evaluated mean change in blood glycated hemoglobin levels. Secondary Outcomes: We also evaluated mean change from baseline in the postmeal area under the curve (AUC) for a range of metabolic parameters. Results: Roflumilast was associated with a significantly greater reduction in glycated hemoglobin levels than placebo (least square mean = -0.45%; P < 0.0001) in patients with DM2. In the roflumilast group, postmeal AUC decreased significantly from baseline to last visit for free fatty acids, glycerol, glucose, and glucagon, whereas they slightly increased for C-peptide and insulin. In contrast to roflumilast, the glucagon AUC increased with placebo, and the insulin AUC decreased. Between-treatment analysis revealed statistically significant differences in favor of roflumilast for glucose (P = 0.0082), glycerol (P = 0.0104), and C-peptide levels (P = 0.0033). Patients in both treatment groups lost weight, although the between-treatment difference of the changes from baseline to last visit [-0.7 (0.4) kg] was not statistically significant (P = 0.0584). Conclusion: Roflumilast lowered glucose levels in patients with newly diagnosed DM2 without COPD, suggesting positive effects on glucose homoeostasis.     

腹腔内促纤维增生性小圆细胞肿瘤4例

目的:探讨腹腔内促纤维增生性小圆细胞瘤(intra-abdominal desmoplastic small round cell tumor,IDSRCT)的临床特点.方法:对我院于1996-06/2006-10收治的4例IDSRCT患者诊疗及预后进行回顾性分析.结果:本研究报道4例患者,均表现为腹水和/或腹部肿物收入院,剖腹探查术发现肿瘤腹腔内广泛种植,术后病理证实为IDSRCT.结论:腹腔内促纤维增生性小圆细胞瘤是一种罕见腹膜恶性肿瘤,诊断时患者已经出现广泛转移且预后不良.     

Cilostazol, an inhibitor of type 3 phosphodiesterase, produces endothelium-independent vasodilation in pressurized rabbit cerebral penetrating arterioles

We investigated the effects of cilostazol, a potent inhibitor of cGMP-inhibited cAMP phosphodiesterase, on mechanical activity of isolated pressurized rabbit cerebral penetrating arterioles with special reference to the function of the endothelium. Both cilostazol and milrinone, another inhibitor of cAMP phosphodiesterase, produced vasodilation of the cerebral penetrating arterioles in a dose-dependent manner. Pretreatment with selective inhibitors of cyclooxygenase or nitric oxide synthase, or chemical denudation of the endothelial cells caused no significant effect on the cilostazol-mediated vasodilation of the cerebral arterioles. A selective large-conductance calcium-activated potassium channel inhibitor, iberiotoxin, and a selective protein kinase A inhibitor, H-89, caused no significant effect on the cilostazol-mediated vasodilation. In the cerebral arterioles, low concentration (10(-6)M) of cilostazol or milrinone caused a significant shift of the dose-vasodilatory response curve for adenosine to the left. These findings suggest that cilostazol produces vasodilation independent of the presence of the endothelium or activation of endogenous vasodilative prostaglandins, nitric oxide, calcium-activated potassium channel and protein kinase A. In conclusion, the vasodilator action of cilostazol may, in part, contribute to the beneficial effect of preventing lacunar cerebral infarction in patients with functional damage of the endothelium in cerebral penetrating arterioles.     

小鼠局灶性脑缺血后乙酰肝素酶的表达

目的检测乙酰肝素酶（Hpa）在实验小鼠局灶性脑缺血后的表达,探讨其表达时间和表达位置变化的规律及其意义。方法用结扎大脑中动脉皮质支的方法制作小鼠局灶性脑缺血模型;碰用实时荧光定啦PCR方法检测缺血后Hpa、血管内皮生长因子（VEGF）和血管生成素2（Ang-2）基因的表达;应用免疫荧光双染（Hpa／CD105、Hpa／GFAP、Hpa／BrdU）的方法进一步观察Hpa蛋白表达的情况。结果实验组小鼠脑缺血后,与假手术组比较,HpamRNA于缺血后3d开始在缺血区的表达明显增高（P〈0．05）,14d达到相对高峰（与1、3、7d和假手术组比较,P〈0．05—0．01）。VEGFmRNA和Ang-2mRNA在脑缺血后3d的表达亦明鼹增高（与假手术组比较,P〈0．01）,其中VEGF的表达水平持续增高,而Ang-2则随后降低：免疫荧光双染显示,Hpa在脑缺血后7d时主要表达于新生的微血管,14d时主要与星形胶质细胞共表达：结论Hpa表达时间和表达位置的变化提示,Hpa参与了脑缺血后血管新生和组织修复的过程,推测Hpa可能通过促进VEGF的表达以及星形胶质细胞的增生而发挥其作用．     

阿尔茨海默病与磷酸二酯酶4相关性的研究进展

随着全球老龄化加剧,老年痴呆最常见的类型阿尔茨海默病(AD)发病呈逐年上升趋势.关于AD的发病机制有多种学说,但β淀粉样蛋白(Aβ)在AD患者的老年斑中选择性沉积是各种原因诱发AD的共同途径,是AD形成和发展的关键因素[1].炎症反应机制是近几年研究的热点,神经元凋亡被认为与Aβ引起的神经元炎症有关.有研究表明AD早期中枢发生了炎症反应,认为由于外周病原体或致炎因子进入中枢,或因神经元自身毒性(如Aβ沉积),激活了小胶质细胞,吞噬病原体或Aβ,同时释放炎症因子,引起炎症因子水平上升[2].     

中性粒细胞弹性蛋白酶抑制剂对小鼠实验性结肠炎的作用研究

目的 观察中性粒细胞弹性蛋白酶(NE)抑制剂西维来司他对葡聚糖硫酸钠(DSS)诱导的小鼠实验性结肠炎的作用.方法 26只健康雄性BALB/C小鼠分为正常对照组(6只)、实验对照组(6只,腹腔注射磷酸盐缓冲液,9 d)、低剂量组(7只,腹腔注射西维来司他50 mg/kg,9 d)、高剂量组(7只,腹腔注射西维来司他100 mg/kg,9 d).除正常对照组外,其余小鼠均予5%DSS溶液自由饮用以制备实验性结肠炎模型.实验第10天时处死全部小鼠并取结肠组织,行组织学损伤评分.酶联免疫吸附法检测小鼠血浆及结肠组织培养上清中NE含量.Western印迹法检测远端结肠组织中NE表达水平.结果 实验对照组小鼠结肠组织学损伤评分(12.00±2.45)显著高于正常对照组(1.88±0.83,P＜0.01).低剂量组和高剂量组的结肠组织学损伤评分差异有统计学意义(分别为10.17±1.17和5.00±1.15,P＜0.05),均显著低于实验对照组(P值均＜0.05),但均显著高于正常对照组(P值均＜0.05).实验对照组血浆NE浓度、结肠组织培养上清NE含量、结肠组织中NE表达水平均较正常对照组明显升高(P值均＜0.05);与实验对照组相比,低剂量组稍有降低(P值均＞0.05),但仍高于正常对照组(P值均＜0.05);高剂量组则显著降低(P值均＜0.05),与正常对照组无差异(P值均＞0.05);高剂量组较实验组和低剂量组显著降低(P值均＜0.05).结论 NE抑制剂西维来司他可改善DSS诱导的小鼠实验性结肠炎病理损伤,高剂量应用效果优于低剂量.NE可能参与溃疡性结肠炎的发病.     

Dipeptidyl peptidase-4 inhibitor use and risk of diabetic retinopathy: A population-based study

Aims

This study examined whether dipeptidyl peptidase (DPP)-4 inhibitor use is beneficial or harmful to diabetic retinopathy (DR) compared with other glucose-lowering agents in patients with type 2 diabetes (T2D).

Effect of cilostazol, a phosphodiesterase inhibitor, on carotid IMT in Japanese type 2 diabetic patients

The aim of this study was to investigate the effect of cilostazol, a cAMP phosphodiesterase inhibitor, on carotid artery intima-media thickness (IMT) and on the incidence of cardiovascular events in Japanese subjects with type 2 diabetes. A total of 62 type 2 diabetic subjects were allocated equally to the cilostazol treatment group (n = 31) and the control group (n = 31). Carotid IMT was evaluated before and after treatment using B-mode ultrasonography. After the study period (mean +/- SD: 2.6 +/- 0.17 years), carotid IMT showed a significantly greater increase in the control group than in the cilostazol group (0.12 +/- 0.14 mm vs. 0.04 +/- 0.02 mm, p < 0.05). In the control group, 1 out of 31 patients suffered from symptomatic cerebral infarction and 1 had angina pectoris during the observation period. On the other hand, no subject in the cilostazol group developed cardiovascular events during the study period. At baseline, the diabetic patients given cilostazol had a significantly lower HbA1c level than the control subjects, but the other atherosclerotic risk factors (BMI, blood pressure, and serum lipids) and the duration of diabetes did not differ between the two groups. These results indicate that cilostazol therapy can attenuate the increase of carotid artery IMT in Japanese subjects with type 2 diabetes.     

Cilomilast for COPD: results of a 6-month, placebo-controlled study of a potent, selective inhibitor of phosphodiesterase 4

BACKGROUND: COPD is a relentless, progressive disease. This study evaluated the efficacy of cilomilast, a selective phosphodiesterase (PDE) 4 inhibitor, in the treatment of COPD. METHODS: This was a randomized, double-blind, placebo-controlled, parallel-group, multicenter study in subjects with COPD. After a 4-week, single-blind, placebo run-in period, eligible subjects were randomized in a 2:1 ratio to receive oral cilomilast, 15 mg bid, or placebo for 24 weeks. Subjects between 40 and 80 years of age who had received a diagnosis of COPD were eligible for the study. The primary efficacy variables were changes from baseline in trough (ie, predose) FEV1 and in total score of the St. George's Respiratory Questionnaire (SGRQ). A key secondary end point was the incidence rate of COPD exacerbations. RESULTS: The average change from baseline in FEV1 over 24 weeks in the cilomilast group was an increase of 10 mL compared with a decrease of 30 mL in the placebo group (difference, 40 mL; p = 0.002). When averaged over 24 weeks, there was a clinically significant reduction in the mean total SGRQ score in subjects receiving cilomilast therapy, with a difference of 4.1 U compared with subjects who received placebo (p = 0.001). A greater percentage of subjects in the cilomilast group were exacerbation-free at 24 weeks (74%; p = 0.008) compared with placebo (62%). Adverse events were generally mild or moderate and were not unexpected for this class of medications. GI adverse events that interfered with daily activities (cilomilast, 17%; placebo, 8%) predominantly occurred within the first 3 weeks of initiating cilomilast therapy. CONCLUSION: Cilomilast is an orally active, potent, and selective inhibitor of PDE-4. Cilomilast maintained pulmonary function and improved health status, and reduced the rate of COPD exacerbations during 24 weeks of treatment. This study supports the use of cilomilast, a novel, selective PDE-4 inhibitor, in subjects with COPD.     

Platelet factor 4: an inhibitor of angiogenesis

Platelet factor 4 (PF4) is an antiangiogenic ELR-negative chemokine. PF4 inhibits endothelial cell proliferation and migration and angiogenesis in vitro and in vivo. Three different mechanisms have been proposed to explain PF4's antiangiogenic effects. First, PF4 may bind proteoglycans and interfere with the proteoglycan-bystander effect on growth factor activity. Second, PF4 is able to interact directly with angiogenesis growth factors such as fibroblast growth factors or vascular endothelial growth factors and inhibits their interaction with cell surface receptors. Third, PF4 may activate cell surface receptors on endothelial cells and induce inhibitory signals. Recently, one such receptor, CXCR3-B, was identified. In cardiovascular disease, PF4 may possibly intervene in collateral vessel formation, plaque neovascularization, heparin-induced thrombocytopenia and stent endothelialization. Several PF4 fragments such as PF4-CTF and modified molecules have been made that exhibit antiangiogenesis properties and may serve as leads for further therapeutic development.     

透明质酸联合羟乙基淀粉预防大鼠术后腹腔粘连的效果观察

目的 探讨透明质酸(HA)、羟乙基淀粉(HES)防粘连剂预防大鼠术后腹腔粘连的最佳剂量及其效果.方法 以HA、HES为原料制备不同浓度的防粘连剂;选择SD大鼠55只,随机分为阴性对照组(生理盐水)、阳性对照组(HA-羧甲基纤维素)、HA组(0.5％ HA和1.0％ HA)、HA+ HES组(1.0％ HA+ 0.03％ HES、1.0％ HA+0.06％ HES、1.0％ HA +0.12％ HES、1.0％ HA+0.24％ HES、1.0％ HA +0.50％ HES);腹腔手术制备大鼠腹腔粘连模型后,分别注入不同浓度的防粘连剂,7d后观察各组的防粘连效果.结果 1.0％HA +0.50％ HES腹腔粘连面积为(0.06 ±0.10)cm2,粘连等级为Ⅰ级,达到理想防粘连效果.结论 1.0％ HA+ 0.50％ HES防粘连剂可明显预防腹腔粘连形成.