背景:许多儿科泌尿科疾病会影响假定的正常组织,或者似乎过于普遍,无法仅基于特定的DNA突变。了解儿科泌尿外科的表观遗传机制,因此,有许多可能影响细胞和组织对环境的反应,如环境和激素对尿道发育的影响,尿路病原感染,阻塞性刺激,所有这些都起源于细胞外或细胞外。的确,细胞对外界刺激的反应通常是表观遗传学介导的。在这篇评论中,我们强调了表观遗传机制的关键作用,如DNA甲基转移酶(DNMT),Zeste多梳抑制复合物2亚基(EZH2)的增强剂,和其他人在三种泌尿外科环境中调节基因表达和细胞功能。
方法:动物和细胞构建体用于建立临床儿科泌尿系病理学模型。肥大,小梁,使用平滑肌细胞模型探索慢性阻塞膀胱的纤维化正常细胞外基质(ECM),以及一种新的慢性阻塞性膀胱疾病(COBD)动物模型,即使在膀胱阻塞后仍保留其病理特征。来自人和鼠尿道下裂或生殖器结节(GT)的细胞模型用于说明关键发育基因的发育反应和表观遗传依赖性。最后,使用膀胱尿路上皮和类器官培养系统,我们检查了表观遗传机制对非尿路致病性反应的活性。泌尿致病性大肠杆菌(UPEC)。在这些模型系统中询问DNMT和EZH2的表达和功能。
结果:无序ECM在体外和体内CODB中对膀胱平滑肌发挥主要的促有丝分裂和表观遗传作用。关键基因,例如,BDNF和KCNB2在积极发展的阻塞和COBD中处于表观遗传调控下,尽管每种情况都显示出不同的表观遗传反应。在尿道下裂的模型中,雌激素强烈失调WNT和Hox表达,通过表观遗传抑制进行归一化。最后,当受到尿路致病性大肠杆菌的攻击时,尿路上皮中的DNA甲基化机制显示出特定的激活。同样,UPEC诱导生长抑制因子p16INK4A的高甲基化和下调。此外,暴露于UPEC的宿主细胞产生的分泌因子诱导表观遗传应答可从一个受影响的细胞转移到另一个,而没有持续的细菌存在。
结论:在三个描述的泌尿系统环境中,微环境影响改变的表观遗传活性。考虑到许多阻塞的膀胱继续显示异常结构和功能障碍,尽管类似于后瓣膜或BPH切除术后的阻塞缓解,所描述的表观遗传机制突出了新的方法来理解潜在的平滑肌肌病的这一关键的临床问题。同样,有证据表明,异种雌激素对尿道下裂的发展有表观遗传学基础,和UTI诱导的表观遗传标记的全尿路上皮改变和随后(复发性)UTI的倾向。机械的影响,荷尔蒙,泌尿生殖系统表观遗传机制活性的感染性触发因素为针对泌尿外科中与这些非癌症疾病相关的表观遗传修饰提供了新的途径。这包括使用基于失活CRISPR的技术进行精确的表观基因组靶向和编辑。总的来说,我们强调了理解儿科泌尿外科表观遗传调控对于开发创新治疗和管理策略的重要性.
BACKGROUND: Many pediatric urology conditions affect putatively normal tissues or appear too commonly to be based solely on specific DNA mutations. Understanding epigenetic mechanisms in pediatric urology, therefore, has many implications that can impact cell and tissue responses to settings, such as environmental and hormonal influences on urethral development, uropathogenic infections, obstructive stimuli, all of which originate externally or extracellularly. Indeed, the cell\'s response to external stimuli is often mediated epigenetically. In this commentary, we highlight work on the critical role that epigenetic machinery, such as DNA methyltransferases (DNMTs), Enhancer of Zeste Polycomb Repressive Complex 2 Subunit (EZH2), and others play in regulating gene expression and cellular functions in three urological contexts.
METHODS: Animal and cellular constructs were used to model clinical pediatric uropathology. The hypertrophy, trabeculation, and fibrosis of the chronically obstructed bladder was explored using smooth muscle cell models employing disorganised vs. normal extracellular matrix (ECM), as well as a new animal model of chronic obstructive bladder disease (COBD) which retains its pathologic features even after bladder de-obstruction. Cell models from human and murine hypospadias or genital tubercles (GT) were used to illustrate developmental responses and epigenetic dependency of key developmental genes. Finally, using bladder urothelial and organoid culture systems, we examined activity of epigenetic machinery in response to non uropathogenic vs. uropathogenic E.coli (UPEC). DNMT and EZH2 expression and function were interrogated in these model systems.
RESULTS: Disordered ECM exerted a principal mitogenic and epigenetic role for on bladder smooth muscle both in vitro and in CODB in vivo. Key genes, e.g., BDNF and KCNB2 were under epigenetic regulation in actively evolving obstruction and COBD, though each condition showed distinct epigenetic responses. In models of hypospadias, estrogen strongly dysregulated WNT and Hox expression, which was normalized by epigenetic inhibition. Finally, DNA methylation machinery in the urothelium showed specific activation when challenged by uropathogenic E.coli. Similarly, UPEC induces hypermethylation and downregulation of the growth suppressor p16INK4A. Moreover, host cells exposed to UPEC produced secreted factors inducing epigenetic responses transmissible from one affected cell to another without ongoing bacterial presence.
CONCLUSIONS: Microenvironmental influences altered epigenetic activity in the three described urologic contexts. Considering that many obstructed bladders continue to display abnormal architecture and dysfunction despite relief of obstruction similar to after resection of posterior valves or BPH, the epigenetic mechanisms described highlight novel approaches for understanding the underlying smooth muscle myopathy of this crucial clinical problem. Similarly, there is evidence for an epigenetic basis of xenoestrogen on development of hypospadias, and UTI-induced pan-urothelial alteration of epigenetic marks and propensity for subsequent (recurrent) UTI. The impact of mechanical, hormonal, infectious triggers on genitourinary epigenetic machinery activity invite novel avenues for targeting epigenetic modifications associated with these non-cancer diseases in urology. This includes the use of deactivated CRISPR-based technologies for precise epigenome targeting and editing. Overall, we underscore the importance of understanding epigenetic regulation in pediatric urology for the development of innovative therapeutic and management strategies.