类器官在再生医学中的应用

类器官是干细胞在体外基质材料支撑条件下培养出来的一种三维微器官,与来源组织器官高度相似。类器官技术为基础研究、药物筛选、再生医学等领域提供了一个新的强大的研究模型和技术手段。再生医学的目的是帮助组织或器官恢复其正常的生理功能,通过与组织工程或基因工程相结合,类器官为再生医学提供了新的移植物来源。该文将介绍类器官在再生医学中的应用,并讨论该领域发展过程中所面临的主要挑战。     

类器官的构建与应用进展

类器官是在体外经由干细胞驱动的, 形成具有来源器官显微解剖特征的多细胞三维结构且能自我更新的微组织。类器官能分化产生器官特异性的多种细胞类型,能重现对应器官的部分功能和空间架构,它的诞生为生命医学研究和临床应用注入了新动能,在癌症基础与临床研究、再生医学等领域表现出广阔的应用前景。对近些年国内外类器官研究进展进行综述,介绍其构建过程与培养体系,并详细阐述其作为体外研究模型的优缺点,为基于类器官的科学研究与应用提供了参考。     

类器官的构建与应用进展

类器官是在体外经由干细胞驱动的, 形成具有来源器官显微解剖特征的多细胞三维结构且能自我更新的微组织。类器官能分化产生器官特异性的多种细胞类型,能重现对应器官的部分功能和空间架构,它的诞生为生命医学研究和临床应用注入了新动能,在癌症基础与临床研究、再生医学等领域表现出广阔的应用前景。对近些年国内外类器官研究进展进行综述,介绍其构建过程与培养体系,并详细阐述其作为体外研究模型的优缺点,为基于类器官的科学研究与应用提供了参考。     

类器官在发育与再生中的研究进展

类器官(organoid)作为体外模拟器官结构和功能的三维培养体系,已经广泛应用于发育研究、疾病建模和药物筛选。类器官在再生医学中具有重要的应用前景。胚胎干细胞、诱导多能性干细胞和多组织成体干/祖细胞来源的类器官再现了发育分化、稳态自我更新和组织损伤再生过程,为揭示发育和再生调控机制、明确生理病理进程提供了可能。近年来,多细胞类型的新型培养模式和单细胞测序等技术的应用促进了类器官的发展。该文总结了类器官在发育与再生中的最新研究成果,并就前沿技术在类器官研究中的应用进行了综述与展望。     

类器官的研究进展及应用

随着人类生物学研究的不断深入,需建立新的模型系统为研究提供了有力的工具。虽然传统的研究模型已被广泛应用,但难以准确反映组织、器官在机体中的生理现象。类器官 (Organoid) 是来源于干细胞或器官祖细胞的三维细胞聚集体,可分化和自组织形成具有人体相应器官的部分特定功能和结构。由于类器官具有人源性,可模拟器官发育和形成,在体外长期扩增中具有基因组稳定性,并能够形成活体生物库进行高通量筛选等优势,成为近年来备受关注的体外模型。目前,利用类器官模型结合新兴的基因编辑、器官芯片、单细胞RNA测序技术等,能够突破传统模型的瓶颈,在器官水平上为疾病模型的建立、药物研发、精准医疗以及再生医学等提供有价值的信息。文中就类器官分类及特性、研究应用、与其他技术结合应用及展望这4个方面进行综述。     

多能干细胞诱导分化为肾脏类器官的研究进展与挑战

用于分化为多种类型细胞的多能干细胞(PSC)体外培养技术已被广泛应用于生物学领域中。由PSC分化而来的肾脏类器官可基本还原生物体内肾脏的组织结构和部分功能,在肾脏疾病模型研究和药物筛选中有重要作用,继续改善肾脏类器官的结构、功能和成熟度将会对肾脏再生治疗提供极大的帮助。研究肾脏类器官的重点在于体外准确模拟体内肾脏的发育过程。本文着重归纳了近十年来对胚胎肾发育过程研究的重点,对肾脏类器官分化技术的几个关键方案进行总结、分析和比较,并探讨肾脏类器官在分化研究和应用中将面临的挑战。     

消化系统类器官研究进展

类器官是一种近年来新发展的细胞三维培养系统。类器官与真实器官的三维结构相似,并具有自我更新和再现组织来源等特点,从而能够更好地模拟真实器官的功能。类器官为研究器官发生、再生、疾病发病机制以及药物筛选提供了一个崭新的研究和应用平台。消化系统在人体内发挥着重要功能,目前已成功建立多种消化器官的类器官模型。本文就近年来味蕾、食管、胃、肝和小肠类器官的研究进展及相关应用进行综述,并对这几种类器官的应用前景进行展望。     

干细胞与再生医学

多能干细胞(PSCs)具有发育的多潜能性,可以分化为机体各种细胞类型,是再生医学领域进行细胞替代治疗以及组织/器官再生的基础.如何由终末分化的体细胞重编程获得病人特异的PSCs,是再生医学领域的核心问题之一,目前主要采取两种重编程策略:借助核移植技术由早期胚胎体外建系获得,或通过诱导重编程技术获得.本文将综述不同多能性等级PSCs的获得方法以及其在多能性机制研究中的应用,并讨论PSCs通过异种嵌合实现组织/器官再造的潜在应用价值.PSCs的研究不仅推动了基础生物学研究的发展,同时也为再生医学走向临床开辟了道路.     

肠道类器官模型检测方法研究进展与初探

肠道类器官是由肠道隐窝或干细胞在3D培养条件下生成的具有肠上皮结构和功能的微型空心球体,目前已被广泛应用于炎症性肠病、肠道损伤再生、肠癌等多种肠道疾病的研究.该文对肠道类器官的常用检测手段进行综述,并对文献报道较多的实验方法进行初探,以期为类器官相关科研及应用提供参考.     

心脏类器官

类器官是体外构建的一类由多种类型细胞组成的,与体内器官或组织高度相似的三维培养物,它能够模拟细胞所属器官的某些结构和生理功能。心血管疾病患病率及死亡率一直处于上升阶段,相关基础研究主要基于细胞和动物模型。心脏类器官是对传统心血管疾病模型的有效补充,在体外更真实和准确地反映人体心脏的生物学特性和功能,使其在疾病机制研究、药物开发、精准医疗和再生医学等领域具有广泛应用前景和独特优势。该文主要介绍了心脏类器官作为新一代疾病模型在心肌梗死、心力衰竭、遗传性心脏病和心律失常等方面的应用,并探讨了类器官技术未来的发展方向和面临的挑战。     

Organoid models of the tumor microenvironment and their applications

A small percentage of data obtained from animal/2D culture models can be translated to humans. Therefore, there is a need to using native tumour microenvironment mimicking models to improve preclinical screening and reduce this attrition rate. For this purpose, currently, the utilization of organoids is expanding. Tumour organoids can recapitulate tumour microenvironment that is including cancer cells and non-neoplastic host components. Indeed, tumour organoids, both phenotypically and genetically, resemble the tumour tissue that originated from it. The unique properties of the tumour microenvironment can significantly affect drug response and cancer progression. In this review, we will discuss about various organoid culture strategies for modelling the tumour immune microenvironment, their applications and advantages in cancer research such as testing cancer immunotherapeutics, developing novel approaches for personalized medicine, testing drug toxicity, drug screening, study cancer initiation and progression, and we will also review the limitations of organoid culture systems.     

类器官的应用研究进展

类器官是利用干细胞的自我更新和分化能力,在体外培养形成的一种微小组织器官类似物,在很大程度上具有体内相应器官的功能。迄今为止,在3D培养条件下,已经成功培养出多种类器官如肺、胃、肠、肝和肾等类器官。它们不仅可作为组织器官的替代品用于药物和临床研究,还可用于体内器官移植。本文综述了类器官在药物毒性检测、药效评价和新药筛选中的作用以及利用类器官建立疾病模型、研究组织器官发育和类器官在精准医疗、再生医学中的价值。     

类器官在乳腺癌相关研究中的应用进展

乳腺癌是女性最常见的癌症,目前乳腺癌的研究主要借助体内模型和传统细胞培养方法,然而研究表明,由于人类和动物之间固有的物种差异,以及器官和细胞之间组织结构的差异,使用上述两种研究方法研制出的药物,在临床试验中失败率高达90%,因此,类器官三维培养应运而生。类器官是一种具有空间结构的三维细胞复合体,它作为一种新的肿瘤研究模型,在精准医疗、器官移植、建立难治疾病模型、基因治疗和药物研发等方向具有广阔的应用前景,是未来生命科学研究的理想载体之一。乳腺癌作为一种表型复杂的异质性疾病,其患者生存率较低,而乳腺癌类器官可以重现人类乳腺癌的许多关键特征,故构建乳腺癌类器官生物库,将会为研究乳腺癌的发生、发展、转移和耐药机制提供一个新的平台。文中将系统介绍类器官的培养条件及其在乳腺癌相关研究中的应用,并对类器官的应用前景进行展望。     

Focus: Personalized Medicine: Value of Organoids from Comparative Epithelia Models

Organoids have tremendous therapeutic potential. They were recently defined as a collection of organ-specific cell types, which self-organize through cell-sorting, develop from stem cells, and perform an organ specific function. The ability to study organoid development and growth in culture and manipulate their genetic makeup makes them particularly suitable for studying development, disease, and drug efficacy. Organoids show great promise in personalized medicine. From a single patient biopsy, investigators can make hundreds of organoids with the genetic landscape of the patient of origin. This genetic similarity makes organoids an ideal system in which to test drug efficacy. While many investigators assume human organoids are the ultimate model system, we believe that the generation of epithelial organoids of comparative model organisms has great potential. Many key transport discoveries were made using marine organisms. In this paper, we describe how deriving organoids from the spiny dogfish shark, zebrafish, and killifish can contribute to the fields of comparative biology and disease modeling with future prospects for personalized medicine.     

The power and the promise of organoid models for cancer precision medicine with next-generation functional diagnostics and pharmaceutical exploitation

As organ-specific three-dimensional cell clusters derived from cancer tissue or cancer-specific stem cells, cancer-derived organoids are organized in the same manner of the cell sorting and spatial lineage restriction in vivo, making them ideal for simulating the characteristics of cancer and the heterogeneity of cancer cells in vivo. Besides the applications as a new in vitro model to study the physiological characteristics of normal tissues and organs, organoids are also used for in vivo cancer cell characterization, anti-cancer drug screening, and precision medicine. However, organoid cultures are not without limitations, i.e., the lack of nerves, blood vessels, and immune cells. As a result, organoids could not fully replicate the characteristics of organs but partially simulate the disease process. This review attempts to provide insights into the organoid models for cancer precision medicine.     

胸腺类器官培养及应用进展

胸腺是人体重要的免疫器官,是T细胞分化成熟的场所,受损后容易引发自身免疫性疾病甚至恶性肿瘤。多年来,研究人员主要通过T细胞体外单层培养系统探索T细胞的发育过程,揭示胸腺损伤和再生的机制。但单层培养系统既不能重现胸腺独特的三维上皮性网状结构,也无法充分提供造血干细胞定向分化为T细胞所需的细胞因子和生长因子。胸腺类器官技术利用具有干细胞潜能的细胞,在体外通过三维培养模拟胸腺的解剖结构和胸腺上皮细胞介导的信号通路,与体内胸腺微环境十分接近。在研究T细胞分化和发育、胸腺相关疾病、重建机体免疫功能以及细胞治疗等方面,胸腺类器官呈现出巨大潜力。文中系统介绍了胸腺类器官的培养方法,比较了培养所用支架的优缺点;同时探讨了胸腺类器官在疾病建模、肿瘤靶向治疗、再生医学和器官移植等领域的应用,并对其前景进行展望。     

Patterning of brain organoids derived from human pluripotent stem cells

The emerging technology of brain organoids deriving from human pluripotent stem cells provides unprecedented opportunities to study human brain development and associated disorders. Various brain organoid protocols have been developed that can recapitulate some key features of cell type diversity, cytoarchitectural organization, developmental processes, functions, and pathologies of the developing human brain. In this review, we focus on patterning of human stem cell-derived brain organoids. We start with an overview of general procedures to generate brain organoids. We then highlight some recently developed brain organoid protocols and chemical cues involved in modeling development of specific human brain regions, subregions, and multiple regions together. We also discuss limitations and potential future improvements of human brain organoid technology.     

The science and engineering of stem cell-derived organoids-examples from hepatic,biliary, and pancreatic tissues

The field of organoid engineering promises to revolutionize medicine with wide-ranging applications of scientific, engineering, and clinical interest, including precision and personalized medicine, gene editing, drug development, disease modelling, cellular therapy, and human development. Organoids are a three-dimensional (3D) miniature representation of a target organ, are initiated with stem/progenitor cells, and are extremely promising tools with which to model organ function. The biological basis for organoids is that they foster stem cell self-renewal, differentiation, and self-organization, recapitulating 3D tissue structure or function better than two-dimensional (2D) systems. In this review, we first discuss the importance of epithelial organs and the general properties of epithelial cells to provide a context and rationale for organoids of the liver, pancreas, and gall bladder. Next, we develop a general framework to understand self-organization, tissue hierarchy, and organoid cultivation. For each of these areas, we provide a historical context, and review a wide range of both biological and mathematical perspectives that enhance understanding of organoids. Next, we review existing techniques and progress in hepatobiliary and pancreatic organoid engineering. To do this, we review organoids from primary tissues, cell lines, and stem cells, and introduce engineering studies when applicable. We discuss non-invasive assessment of organoids, which can reveal the underlying biological mechanisms and enable improved assays for growth, metabolism, and function. Applications of organoids in cell therapy are also discussed. Taken together, we establish a broad scientific foundation for organoids and provide an in-depth review of hepatic, biliary and pancreatic organoids.     

Establishment of intestinal organoid cultures modeling injury-associated epithelial regeneration

The capacity of 3D organoids to mimic physiological tissue organization and functionality has provided an invaluable tool to model development and disease in vitro. However, conventional organoid cultures primarily represent the homeostasis of self-organizing stem cells and their derivatives. Here, we established a novel intestinal organoid culture system composed of 8 components, mainly including VPA, EPZ6438, LDN193189, and R-Spondin 1 conditioned medium, which mimics the gut epithelium regeneration that produces hyperplastic crypts following injury; therefore, these organoids were designated hyperplastic intestinal organoids (Hyper-organoids). Single-cell RNA sequencing identified different regenerative stem cell populations in our Hyper-organoids that shared molecular features with in vivo injury-responsive Lgr5⁺ stem cells or Clu⁺ revival stem cells. Further analysis revealed that VPA and EPZ6438 were indispensable for epigenome reprogramming and regeneration in Hyper-organoids, which functioned through epigenetically regulating YAP signaling. Furthermore, VPA and EPZ6438 synergistically promoted regenerative response in gut upon damage in vivo. In summary, our results demonstrated a new in vitro organoid model to study epithelial regeneration, highlighting the importance of epigenetic reprogramming that pioneers tissue repair.Subject terms: Intestinal stem cells, Regeneration     

Drug screening model meets cancer organoid technology

Tumor organoids inherit the genomic and molecular characteristics of the donor tumor, which not only bridge the gap between genome and phenotype but also circumvent the disadvantages such as genetic information change by using 2D cell lines and the mouse-specific tumor evolution in patient-derived xenograft (PDX). So, cancer organoid has been widely applied to preclinical drug evaluation, biomarker identification, biological research, and individualized therapy. Besides, cancer organoid can be preserved, resuscitated, passed infinitely, and mechanically cultured on a chip for drug screening; it has become one of the partial models for low/high-throughput drug screening in the preclinical trial in vitro. Therefore, this review presents the recent developments of tumor organoids for drug screening, which will introduce from four aspects, including the stability/credibility, types, application, deficiency and prospect of the tumor organoids model for drug screening.