磷酸二酯酶4抑制剂临床及安全性研究进展

磷酸二酯酶4 (phosphodiesterase 4, PDE4)是磷酸二酯酶家族中重要成员之一,可特异性水解环磷酸腺苷(cyclic adenosine monophosphate, cAMP),通过改变cAMP浓度引发下游磷酸化级联反应,与多种疾病密切相关。靶向PDE4的抑制剂临床研究包括呼吸系统疾病、自身免疫性疾病、中枢神经系统疾病及皮肤病等多种疾病领域。但是在已上市的PDE4抑制剂临床研究中发现,大多数药物的恶心、呕吐等胃肠道不良反应发生率较高,限制了其临床应用。因此本综述总结了已上市PDE4抑制剂的临床进展及安全性问题,结合PDE4蛋白结构分析、PDE4抑制剂的作用机制及相关不良反应机制研究,阐述了PDE4抑制剂产生不良反应的主要原因,旨在为开发安全有效的PDE4抑制剂提供参考。     

新型磷酸二酯酶特异性抑制剂的发现及识别机制

磷酸二酯酶(PDE)通过催化水解细胞内第二信使(环磷酸腺苷cAMP,或环磷酸鸟苷cGMP),以降低细胞内cAMP或cGMP的浓度,从而中止这两个第二信使所传导的生理作用。PDEs作为新型的药物作用靶点,参与多种疾病的治疗,已成为新药研发的重要靶点。截至目前,已有多个PDE抑制剂药物上市(PDE5:5个,治疗性功能障碍和肺动脉高压;PDE4:3个,治疗慢性阻塞性肺病等),其中最出名的案例是用于治疗男性勃起功能障碍和肺动脉高压的PDE5抑制剂西地那非。然而,低选择性是这些PDE抑制剂的主要缺陷。近期我们针对PDE4,5,8,9和10等亚型,通过基于结构的药物分子设计,合成并发现多类高选择性的抑制剂。如,1)合成近150个PDE9抑制剂,从中发现抑制效应最强的高选择性先导结构3r。3r(IC_(50)=0.6 nmol·L~(-1),对PDE1选择性为788倍),活性和选择性均明显优于临床Ⅱ期的辉瑞抑制剂PF-04447943。通过晶体结构分析,发现3r与PDE9特有残基Y424形成氢键,是其具有高倍选择性的结构基础,这为PDE9高选择性抑制剂提供了新的设计策略。此外共晶结构还揭示3r和A452形成一个氢键,而PF-04447943未显示这种结合模式。通过设计与A452形成氢键,可提高化合物的抑制效应。2)合成近100个多个PDE5抑制剂,从中发现抑制剂从中发现抑制效应最强的高选择性先导结构1610。1610(IC_(50)=5.0 nmol·L~(-1),对PDE6选择性为100倍)的抑制活性与辉瑞药物西地那非相当,但选择性均明显优于西地那非(对PDE6选择性为2~3倍),动物实验也显示该类药物的抗动脉高压效果明显优于对照药物西地那非。通过分子模拟分析,发现1610进入靶标结构的Q2口袋,是1610具有100倍选择性的结构基础,这为PDE5高选择性抑制剂提供了新的设计策略。     

选择性磷酸二酯酶Ⅳ抑制剂的研究

磷酸二酯酶Ⅳ（PDE－4）主要分布于各类炎性细胞，能专一性水解环腺苷酸（cAMP),促进炎症的发展。PDE－4抑制剂通过选择性抑制PDE－4、使胞内cAMP水平升高，在抗炎和抗哮喘方面显示了广阔的应用前景。将PDE－4抑制剂分为儿茶酚醚类、苯甲酰胺类、喹唑啉二酮类、黄嘌呤类、苯并呋喃类等，分别综述其构效关系研究和临床开发应用。     

非选择性磷酸二酯酶抑制剂用于人工精子激活的研究进展

人工精子激活基础研究和临床辅助生殖技术治疗中应用最广泛的精子激活因子为非选择性磷酸二酯酶(PDE)抑制剂。利用非选择性PDE抑制剂处理精子能够全面抑制PDE的活性,通过加强胞内环磷酸腺苷(cAMP)信号来提升精子运动能力。基于人工精子激活的重要作用靶点PDE,综述了3种常用非选择性PDE抑制剂咖啡因、己酮可可碱和茶碱对人精子运动的激活效应的研究进展,为非选择性PDE抑制剂用于人工精子激活提供参考。     

PDE4/PDE7双重抑制剂的研究进展

目的为进一步研究磷酸二酯酶抑制剂提供参考。方法对磷酸二酯酶4(PDE4)和磷酸二酯酶7(PDE7)的组织分布、生理功能、催化区域的结构特点和PDE4/PDE7双重抑制剂研发的最新进展进行综述。结果 PDE4/PDE7双重抑制剂具有显著的抗炎作用,且能够避免单一性的PDE4选择性抑制剂药物具有如恶心、呕吐等副作用。结论 PDE4/PDE7双重抑制剂有希望成为新一代的抗炎药物。     

选择性磷酸二酯酶同功酶抑制剂与支气管哮喘的治疗

目前认为茶碱类药物毒副作用的产生与其非特异性地抑制磷酸二酯酶 (PDE)同工酶有关。为避免PDE同工酶被广泛抑制所产生的毒副作用 ,近年来选择性PDE同功酶抑制剂成为人们研究的热点。与哮喘治疗有关的主要是选择性PDE4 ,PDE3/PDE4或PDE3抑制剂。大量的临床前研究证明它们具有免疫调节和抗炎、舒张支气管平滑肌等作用。早期临床研究也表明它们治疗哮喘有效。虽然它们仍存在副作用较多且疗效不佳等缺点 ,但可以相信 ,随着人们对PDE同工酶认识的更进一步深入 ,必将会开发出疗效更佳、更安全的抑制剂 ,为哮喘的治疗提供一种新的选择     

磷酸二酯酶5抑制剂的研究进展

磷酸二酯酶5（PDE5）是磷酸二酯酶家族中的一员,以水解和环磷酸鸟苷为主,广泛分布于血管平滑肌和气管平滑肌,在血小板、肾脏以及阴茎海绵体也有分布。临床试验证明,PDE5抑制剂具有降低肺动脉高压、抗血栓、治疗心绞痛和勃起功能障碍等作用。综述PDE5的分子结构、调节机制以及PDE5抑制剂的构效关系和临床应用。     

cGMP特异性磷酸二酯酶5活性及其抑制剂的研究

目的研究以cGMP为特异底物的磷酸二酯酶 5 (PDE5 )的水解酶活性及PDE5选择性抑制剂西地那非(sildenafil)的抑制作用。方法以牛阴茎海绵体为原料 ,通过快速蛋白液相系统分离纯化得到PDE同工酶 ,然后以3 H cGMP为底物 ,经纯化的PDE同工酶催化水解为3 H GMP ,进一步在含 5′ 核苷酸酶的蛇毒液作用下 ,脱去 5′ 磷酸生成3 H 鸟苷 ,在闪烁剂激发下测定3 H 鸟苷的变化 ,绘制PDE活性曲线。以不同剂量的PDE5选择性抑制剂西地那非作用于PDE5 ,经DixonPlots法处理结果以观察西地那非的抑制效应。结果由牛阴茎海绵体纯化得到三个PDE同工酶峰 ,其中第三个峰对cGMP水解活性最强 ,且西地那非对第三峰抑制作用明显。结论海绵体中的PDE以cGMP 特异的PDE5为主 ,西地那非是PDE5的选择性抑制剂 ,通过以上实验观察可初步确定第三峰为PDE5 ,其结果与文献报道相符。     

用于治疗呼吸系统疾病的双靶点PDE3/4抑制剂研究进展

慢性阻塞性肺病和哮喘是以气道阻塞为主要表现的复杂炎症性疾病,已成为严重影响人类健康的呼吸道常见疾病。与临床单独使用PDE3或PDE4抑制剂相比,双靶点PDE3/4抑制剂具有协同的抗炎和支气管扩张作用,近年来引起广泛关注。本文综述目前处于临床前和临床研究阶段的双靶点PDE3/4抑制剂代表性研究成果,总结其最新进展及用于治疗慢性阻塞性肺病和哮喘的潜力。     

西洛他唑治疗心动过缓的研究进展

磷酸二酯酶Ⅲ(PDEⅢ)型抑制剂西洛他唑具有抗血小板凝集和血管舒展的作用,临床用于治疗稳定性间歇性跛行,最近研究发现其具有治疗心动过缓的作用。现综述西洛他唑治疗心动过缓的机制,认为西洛他唑对PDEⅢA的抑制是产生治疗心动过缓的主要原因,进而讨论其与PDEⅢ的结合模型,通过结合模型总结了构效关系。     

Overview: Diabetes: New Chemical Entities

There has been an increasing interest in the development of phosphodiesterase (PDE) inhibitors for the treatment of cognitive dysfunctions. In this editorial, the mechanism of action of PDEs is briefly described, while the effects of different PDE inhibitors in preclinical models are reviewed. Based on the expression of PDE mRNA in the human brain, it is suggested that PDE1 and PDE10 inhibitors are strong candidates for the development of cognition enhancers. However, the complex nature of the expression of PDEs in the brain warrants further research into the role of PDEs in the signaling pathways in brain circuits. The development of PDE inhibitors, which are selective for PDE splicing isoforms, may be promising for future drug development.     

磷酸二酯酶抑制剂药理学作用机制和临床应用研究进展

磷酸二酯酶(phosphodiesteras,PDE)可降解机体细胞内环磷酸腺苷(cyclic adenosine monophosphate,cAMP)和环磷酸鸟苷(cyclic guanosine monophosphate,cGMP).PDE抑制剂可降低PDE活性,从而减弱其对cAMP和cGMP的降解能力.机体不...     

磷酸二酯酶-4抑制剂的研究进展

目的综述磷酸二酯酶-4(phosphodiesterase-4,PDE-4)的生理活性及其抑制剂的研究进展。方法查阅近年来国内外相关文献31篇,对其进行归纳、总结和分析。结果 PDE-4抑制剂通过对PDE-4的抑制作用,阻止环磷酸腺苷的水解,在哮喘和慢性阻塞性肺炎等炎症疾病方面作用显著。目前,罗氟司特已经通过美国FDA批准上市,许多活性较强、不良反应较少的PDE-4抑制剂相继进入了临床阶段。结论 PDE-4作为重要的炎症靶点之一得到了深入的研究,其抑制剂发展迅速,具有良好的开发前景。     

Phosphodiesterase (PDE5) inhibition assay for rapid detection of erectile dysfunction drugs and analogs in sexual enhancement products

Products marketed as dietary supplements for sexual enhancement are frequently adulterated with phosphodiesterase‐5 (PDE5) inhibitors, which are erectile dysfunction drugs or their analogs that can cause adverse health effects. Due to widespread adulteration, a rapid screening assay was developed to detect PDE5 inhibitors in adulterated products. The assay employs fluorescence detection and is based on measuring inhibition of PDE5 activity, the pharmacological mechanism shared among the adulterants. Initially, the assay reaction scheme was established and characterized, followed by analysis of 9 representative PDE5 inhibitors (IC₅₀, 0.4–4.0 ng mL^–1), demonstrating sensitive detection in matrix‐free solutions. Next, dietary supplements serving as matrix blanks (n = 25) were analyzed to determine matrix interference and establish a threshold value; there were no false positives. Finally, matrix blanks were spiked with 9 individual PDE5 inhibitors, along with several mixtures. All 9 adulterants were successfully detected (≤ 5 % false negative rate; n = 20) at a concentration of 1.00 mg g^–1, which is over 5 times lower than concentrations commonly encountered in adulterated products. A major distinction of the PDE5 inhibition assay is the ability to detect adulterants without prior knowledge of their chemical structures, demonstrating a broad‐based detection capability that can address a continuously evolving threat of new adulterants. The PDE5 inhibition assay can analyze over 40 samples simultaneously within 15 minutes and involves a single incubation step and simple data analysis, all of which are advantageous for combating the widespread adulteration of sex‐enhancement products.     

Dual PDE3/4 inhibitors as therapeutic agents for chronic obstructive pulmonary disease

Phosphodiesterase (PDE)4, and to a lesser extent, PDE3/4 inhibitors have attracted considerable interest as potential therapeutic agents for diseases including chronic obstructive pulmonary disease. Indeed, ibudilast and theophylline are utilized clinically, and roflumilast is in late-stage clinical development. Unfortunately, however many PDE4 and dual PDE3/4 inhibitors have failed in early development due to low therapeutic ratios. The majority of these compounds are however orally administered and non-selective for either PDE3(A, B) or PDE4(A, B, C, D) subtypes. Developing an inhaled dual PDE3/4 inhibitor with subtype specificity may represent one strategy to improve the therapeutic index. Indeed combined inhibition of PDE3 and PDE4 inhibitor has additive and synergistic anti-inflammatory and bronchodilatory effects versus inhibition of either PDE3 or PDE4 alone. Given that synergy has been seen in terms of efficacy end points, an obvious concern is that synergy may also be observed in side effects. Interestingly, however, no synergy or additive effects with a combination of a PDE3 and PDE4 inhibitor in a cardiomyocyte assay were observed. This review will summarize the rationale for developing an inhaled dual PDE3/4 inhibitor, as a treatment for chronic obstructive pulmonary disease together with recent advances in trying to understand the pathogenesis of PDE inhibitor-induced mesenteric vasculitis (a key potential dose-limiting side effect of these agents), highlighting potential early and sensitive predictive biomarkers.     

PDE4 inhibitors 1999

The search for novel phosphodiesterase Type 4 (PDE4) inhibitors remains one of the most active fields within the pharmaceutical industry. Recent progress within the clinical development of PDE4 inhibitors has seen two more compounds progress to Phase III development. However, both Ariflo? (SB-207499) and roflumilast are being developed principally for the treatment of chronic obstructive pulmonary disease (COPD) rather than asthma. This review also highlights the novel structural classes of PDE4 inhibitors disclosed in the past year’s patent applications and the concentration of effort on the identification of selective PDE4D inhibitors.     

Phosphodiesterase-4 as a potential drug target

Phosphodiesterase-4 (PDE4) is the predominant enzyme in some specific cell types that is responsible for the degradation of the second messenger, cAMP. Consequently, PDE4 plays a crucial role in cell signalling and, as such, it has been the target of clinical drug development of various indications, ranging from anti-inflammation to memory enhancement. In this review, the fundamental biological role of PDE4 in intracellular signalling, its tissue distribution and regulation are described. The historical development of various chemical classes of PDE4 inhibitors and the challenges that face these inhibitors as therapeutics are also discussed. Finally, recent advances in the structural biology of PDE4 and their complexes with various inhibitors, as well as its potential impact on the rational design of potent and selective PDE4 inhibitors, are presented.     

Expression of cyclic GMP-inhibited phosphodiesterases 3A and 3B (PDE3A and PDE3B) in rat tissues: Differential subcellular localization and regulated expression by cyclic AMP

1. A combination of pharmacological, molecular biological and biochemical approaches were used to investigate the differential expression of two cyclic GMP-inhibited cyclic nucleotide phosphodiesterase genes (PDE3A and PDE3B) in the rat.
2. RT–PCR using PDE3A- or PDE3B-specific oligonucleotide primers allowed amplification of products encoding PDE3A (508 bp) or PDE3B (499 bp) sequences from several rat tissues (heart, aorta, liver, kidney and epididymal fat), from primary cultures of aortic vascular smooth muscle cells (VSMC) as well as from an SV40 large T-antigen immortalized aortic VSMC line.
3. Immunoblotting experiments with PDE3-selective antisera allowed the detection of both PDE3A and PDE3B immunoreactive proteins in several rat tissues, including tissues of the cardiovascular system, in primary cultures of aortic VSMC and in an SV40 large T-antigen immortalized aortic VSMC line. In all cases, PDE3A was expressed as a 120 kDa protein which was only detected in the cytosolic fraction. PDE3B was expressed as a 135 kDa protein and its expression was limited to the particulate fraction of all tissues and cells studied.
4. Prolonged incubation of cultured aortic VSMC with agents that increase VSMC cyclic AMP (forskolin or 8-bromo-cyclic AMP) produced marked time-dependent increases in PDE3 activity which correlated with increases in PDE3A and PDE3B RT–PCR signals and a marked increase in particulate PDE3 activity and PDE3B protein.
5. The physiological, pharmacological and biochemical implications of these findings are discussed based on previous reports of the effects of PDE3 inhibitors in the cardiovascular system and the relevance of our findings are presented in the context of the development of PDE3A and/or PDE3B-selective pharmacological agents.