scholarly journals Renal reabsorption in 3D vascularized proximal tubule models

2019 ◽  
Vol 116 (12) ◽  
pp. 5399-5404 ◽  
Author(s):  
Neil Y. C. Lin ◽  
Kimberly A. Homan ◽  
Sanlin S. Robinson ◽  
David B. Kolesky ◽  
Nathan Duarte ◽  
...  
Keyword(s):  
Proximal Tubule ◽  
Disease Modeling ◽  
Three Dimensional ◽  
Kidney Tissue ◽  
Renal Reabsorption ◽  
Native Kidney ◽  
Glucose Reabsorption ◽  
Diseased State ◽  
And Function

Three-dimensional renal tissues that emulate the cellular composition, geometry, and function of native kidney tissue would enable fundamental studies of filtration and reabsorption. Here, we have created 3D vascularized proximal tubule models composed of adjacent conduits that are lined with confluent epithelium and endothelium, embedded in a permeable ECM, and independently addressed using a closed-loop perfusion system to investigate renal reabsorption. Our 3D kidney tissue allows for coculture of proximal tubule epithelium and vascular endothelium that exhibits active reabsorption via tubular–vascular exchange of solutes akin to native kidney tissue. Using this model, both albumin uptake and glucose reabsorption are quantified as a function of time. Epithelium–endothelium cross-talk is further studied by exposing proximal tubule cells to hyperglycemic conditions and monitoring endothelial cell dysfunction. This diseased state can be rescued by administering a glucose transport inhibitor. Our 3D kidney tissue provides a platform for in vitro studies of kidney function, disease modeling, and pharmacology.

scholarly journals Developments and Opportunities for 3D Bioprinted Organoids

2021 ◽  
Vol 7 (3) ◽  
pp. 364
Author(s):  
Ya Ren ◽  
Xue Yang ◽  
Zhengjiang Ma ◽  
Xin Sun ◽  
Yuxin Zhang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Biology ◽  
Adult Stem Cells ◽  
Materials Science ◽  
Disease Modeling ◽  
Three Dimensional ◽  
Key Characteristics ◽  
And Function ◽  
Further Development

Organoids developed from pluripotent stem cells or adult stem cells are three-dimensional cell cultures possessing certain key characteristics of their organ counterparts, and they can mimic certain biological developmental processes of organs in vitro. Therefore, they have promising applications in drug screening, disease modeling, and regenerative repair of tissues and organs. However, the construction of organoids currently faces numerous challenges, such as breakthroughs in scale size, vascularization, better reproducibility, and precise architecture in time and space. Recently, the application of bioprinting has accelerated the process of organoid construction. In this review, we present current bioprinting techniques and the application of bioinks and summarize examples of successful organoid bioprinting. In the future, a multidisciplinary combination of developmental biology, disease pathology, cell biology, and materials science will aid in overcoming the obstacles pertaining to the bioprinting of organoids. The combination of bioprinting and organoids with a focus on structure and function can facilitate further development of real organs.

scholarly journals Human iPSC-Based Modeling of Central Nerve System Disorders for Drug Discovery

2021 ◽  
Vol 22 (3) ◽  
pp. 1203
Author(s):  
Lu Qian ◽  
Julia TCW
Keyword(s):  
Drug Discovery ◽  
Disease Modeling ◽  
Three Dimensional ◽  
Structural Complexity ◽  
Induced Pluripotent Stem Cell ◽  
Cell Types ◽  
Central Nerve System ◽  
Human Ipscs ◽  
Nerve System

A high-throughput drug screen identifies potentially promising therapeutics for clinical trials. However, limitations that persist in current disease modeling with limited physiological relevancy of human patients skew drug responses, hamper translation of clinical efficacy, and contribute to high clinical attritions. The emergence of induced pluripotent stem cell (iPSC) technology revolutionizes the paradigm of drug discovery. In particular, iPSC-based three-dimensional (3D) tissue engineering that appears as a promising vehicle of in vitro disease modeling provides more sophisticated tissue architectures and micro-environmental cues than a traditional two-dimensional (2D) culture. Here we discuss 3D based organoids/spheroids that construct the advanced modeling with evolved structural complexity, which propels drug discovery by exhibiting more human specific and diverse pathologies that are not perceived in 2D or animal models. We will then focus on various central nerve system (CNS) disease modeling using human iPSCs, leading to uncovering disease pathogenesis that guides the development of therapeutic strategies. Finally, we will address new opportunities of iPSC-assisted drug discovery with multi-disciplinary approaches from bioengineering to Omics technology. Despite technological challenges, iPSC-derived cytoarchitectures through interactions of diverse cell types mimic patients’ CNS and serve as a platform for therapeutic development and personalized precision medicine.

Abstract 142: Defining the Non-Myocyte Compartment is Key for Enhanced Maturation of Human Engineered Heart Muscle

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Malte Tiburcy ◽  
James E Hudson ◽  
Dirk Ziebolz ◽  
Wolfram H Zimmermann
Keyword(s):  
Heart Muscle ◽  
Muscle Development ◽  
Disease Modeling ◽  
Cardiac Differentiation ◽  
Inotropic Response ◽  
Double Positive ◽  
Human Cardiomyocytes ◽  
Functional Maturation ◽  
And Function

Background: Tissue engineering of heart muscle from human pluripotent stem cells holds great potential for in vitro studies, disease modeling, and cardiac replacement therapy. A number of variables may however affect maturation and function of human cardiomyocytes (CM) in tissue engineered heart muscle (EHM). Here, we hypothesized that defined non-myocyte (NM) populations support structural and functional maturation of EHM. Methods and Results: To investigate the role of non-myocytes (NM) for heart muscle assembly in vitro we generated EHM from purified CM (93±1.5% actinin+) and a mixture of CM and NM (70/30%). Notably, only the NM-supplemented EHM generated measurable forces (0.8±0.1 mN, n=9) with anisotropically aligned cardiomyocytes. Depending on pluripotent stem cell line and differentiation protocol the NM compartment may vary considerably. To further define the influence of the NM compartment we generated EHM from HES2-derived CM with undefined NM, i.e the NM typically derived during cardiac differentiation, and defined NM (fibroblasts). Defined EHM were more mature with higher forces and lower variability between experimental series (defined: 9.8±0.9 nN/CM, undefined: 4.7±1.4 nN/CM, n=10/9), higher EC50 for calcium, and enhanced inotropic response to isoprenaline despite comparable CM:NM composition of 1:1. Increased actinin protein per CM, a reduction of MLC2V/2A double positive CM, and evidence of CM cycle withdrawal indicated enhanced ventricular maturation in defined EHM. Next, we tested whether defining cell composition and NM in iPS-derived EHM will yield a comparable functional phenotype to HES2-EHM. In agreement with the above data, defined iPS-EHM displayed advanced functional maturation with high specific forces, comparable calcium EC50, and inotropic response to isoprenaline. Summary and Conclusions: Here we demonstrate that defining the NM compartment is essential for optimized human heart muscle formation and maturation in vitro. Moreover, our data provide (1) evidence for the applicability of EHM in modelling of heart muscle development and (2) a strong rationale for the need to define CM and NM compartments in tissue engineered myocardium to reduce variability in applications such as disease modelling.

Advances in aptamer evolution and engineering

2016 ◽  
Author(s):  
◽  
Khalid Kamal Alam
Keyword(s):  
High Throughput Sequencing ◽  
Target Selection ◽  
Three Dimensional ◽  
Rna Aptamers ◽  
Hiv Reverse Transcriptase ◽  
University Of Missouri ◽  
Selection Approach ◽  
And Function ◽  
The University

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Aptamers are single-stranded nucleic acids that fold into unique three-dimensional shapes that allow them to bind with high affinity and specificity to targets of interest. They are selected through the process of in vitro evolution, wherein large libraries of randomized sequence are iteratively partitioned and amplified to enrich for high-fitness, functional molecules. Selected libraries are sequenced and individual aptamers are characterized for their structure and function. Aptamers have found use as research tools, diagnostics, and therapeutics and in the control of biological systems. The work described herein presents several advancements to the selection and application of aptamers. I first describe an aptamer bioinformatics platform, FASTAptamer, which performs the primary sequence tasks common to all combinatorial selection techniques. I then describe a poly-target selection approach that leverages high-throughput sequencing, the aptamer bioinformatics platform, and parallel selections against a family of related targets to identify the first RNA aptamers capable of potent broad-spectrum inhibition of HIV reverse transcriptase. Finally, this work describes the engineering and in vitro validation of a bifurcated aptamer, Split-Broccoli, for direct visualization of RNA:RNA processes.

scholarly journals Spheroids as a Type of Three-Dimensional Cell Cultures—Examples of Methods of Preparation and the Most Important Application

2020 ◽  
Vol 21 (17) ◽  
pp. 6225 ◽  
Author(s):  
Kamila Białkowska ◽  
Piotr Komorowski ◽  
Maria Bryszewska ◽  
Katarzyna Miłowska
Keyword(s):  
Cell Cultures ◽  
Cell Biology ◽  
Disease Modeling ◽  
Three Dimensional ◽  
3D Culture ◽  
Matrix Interactions ◽  
Vitro Model ◽  
Extracellular Matrix Interactions ◽  
Natural Cell

Cell cultures are very important for testing materials and drugs, and in the examination of cell biology and special cell mechanisms. The most popular models of cell culture are two-dimensional (2D) as monolayers, but this does not mimic the natural cell environment. Cells are mostly deprived of cell–cell and cell–extracellular matrix interactions. A much better in vitro model is three-dimensional (3D) culture. Because many cell lines have the ability to self-assemble, one 3D culturing method is to produce spheroids. There are several systems for culturing cells in spheroids, e.g., hanging drop, scaffolds and hydrogels, and these cultures have their applications in drug and nanoparticles testing, and disease modeling. In this paper we would like to present methods of preparation of spheroids in general and emphasize the most important applications.

scholarly journals Genomics Analysis of Metabolic Pathways of Human Stem Cell-Derived Microglia-Like Cells and the Integrated Cortical Spheroids

2019 ◽  
Vol 2019 ◽  
pp. 1-21 ◽  
Author(s):  
Julie Bejoy ◽  
Xuegang Yuan ◽  
Liqing Song ◽  
Thien Hua ◽  
Richard Jeske ◽  
...  
Keyword(s):  
Brain Tissue ◽  
Metabolic Pathways ◽  
Disease Modeling ◽  
Aerobic Glycolysis ◽  
Three Dimensional ◽  
Initiation Factor ◽  
Human Brain Tissue ◽  
P53 Signaling

Brain spheroids or organoids derived from human pluripotent stem cells (hiPSCs) are still not capable of completely recapitulating in vivo human brain tissue, and one of the limitations is lack of microglia. To add built-in immune function, coculture of the dorsal forebrain spheroids with isogenic microglia-like cells (D-MG) was performed in our study. The three-dimensional D-MG spheroids were analyzed for their transcriptome and compared with isogenic microglia-like cells (MG). Cortical spheroids containing microglia-like cells displayed different metabolic programming, which may affect the associated phenotype. The expression of genes related to glycolysis and hypoxia signaling was increased in cocultured D-MG spheroids, indicating the metabolic shift to aerobic glycolysis, which is in favor of M1 polarization of microglia-like cells. In addition, the metabolic pathways and the signaling pathways involved in cell proliferation, cell death, PIK3/AKT/mTOR signaling, eukaryotic initiation factor 2 pathway, and Wnt and Notch pathways were analyzed. The results demonstrate the activation of mTOR and p53 signaling, increased expression of Notch ligands, and the repression of NF-κB and canonical Wnt pathways, as well as the lower expression of cell cycle genes in the cocultured D-MG spheroids. This analysis indicates that physiological 3-D microenvironment may reshape the immunity of in vitro cortical spheroids and better recapitulate in vivo brain tissue function for disease modeling and drug screening.

scholarly journals Challenges in Modeling Human Neural Circuit Formation via Brain Organoid Technology

2020 ◽  
Vol 14 ◽  
Author(s):  
Takeshi K. Matsui ◽  
Yuichiro Tsuru ◽  
Ken-ichiro Kuwako
Keyword(s):  
Human Brain ◽  
Brain Development ◽  
Neural Circuit ◽  
Disease Modeling ◽  
Three Dimensional ◽  
Neural Lineage ◽  
Human Brain Development ◽  
Brain Organoid ◽  
Circuit Formation

Human brain organoids are three-dimensional self-organizing tissues induced from pluripotent cells that recapitulate some aspects of early development and some of the early structure of the human brain in vitro. Brain organoids consist of neural lineage cells, such as neural stem/precursor cells, neurons, astrocytes and oligodendrocytes. Additionally, brain organoids contain fluid-filled ventricle-like structures surrounded by a ventricular/subventricular (VZ/SVZ) zone-like layer of neural stem cells (NSCs). These NSCs give rise to neurons, which form multiple outer layers. Since these structures resemble some aspects of structural arrangements in the developing human brain, organoid technology has attracted great interest in the research fields of human brain development and disease modeling. Developmental brain disorders have been intensely studied through the use of human brain organoids. Relatively early steps in human brain development, such as differentiation and migration, have also been studied. However, research on neural circuit formation with brain organoids has just recently began. In this review, we summarize the current challenges in studying neural circuit formation with organoids and discuss future perspectives.

Constructing stem cell microenvironments using bioengineering approaches

2013 ◽  
Vol 45 (23) ◽  
pp. 1123-1135 ◽  
Author(s):  
David A. Brafman
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Disease Modeling ◽  
Mechanical Stimuli ◽  
Culture Methods ◽  
Stem Cell Fate ◽  
And Function

Within the adult organism, stem cells reside in defined anatomical microenvironments called niches. These architecturally diverse microenvironments serve to balance stem cell self-renewal and differentiation. Proper regulation of this balance is instrumental to tissue repair and homeostasis, and any imbalance can potentially lead to diseases such as cancer. Within each of these microenvironments, a myriad of chemical and physical stimuli interact in a complex (synergistic or antagonistic) manner to tightly regulate stem cell fate. The in vitro replication of these in vivo microenvironments will be necessary for the application of stem cells for disease modeling, drug discovery, and regenerative medicine purposes. However, traditional reductionist approaches have only led to the generation of cell culture methods that poorly recapitulate the in vivo microenvironment. To that end, novel engineering and systems biology approaches have allowed for the investigation of the biological and mechanical stimuli that govern stem cell fate. In this review, the application of these technologies for the dissection of stem cell microenvironments will be analyzed. Moreover, the use of these engineering approaches to construct in vitro stem cell microenvironments that precisely control stem cell fate and function will be reviewed. Finally, the emerging trend of using high-throughput, combinatorial methods for the stepwise engineering of stem cell microenvironments will be explored.

scholarly journals The Science and Engineering of Stem Cell–Derived Organoids-Examples from Hepatic, Biliary, and Pancreatic Tissues

2020 ◽  
Author(s):  
Ogechi Ogoke ◽  
Mitchell Maloy ◽  
Natesh Parashurama
Keyword(s):  
Stem Cell ◽  
Cellular Therapy ◽  
Disease Modeling ◽  
Historical Context ◽  
Three Dimensional ◽  
Self Organization ◽  
Wide Range ◽  
Clinical Interest ◽  
And Function ◽  
Better Than

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 modeling, cellular therapy, and a basic understanding of human development. Organoids are a three-dimensional (3D), miniature, caricature of a target organ, are initiated with stem/progenitor cells, and are extremely promising tools to model organ function. The biological basis for organoids is that they foster stem cell-self renewal, differentiation, and self-organization, recapitulating tissue structure or function better than 2D systems. In this review, we first discuss the importance of epithelial organs and the general properties of epithelial cells to provide context for the liver, pancreas, and gall bladder and rationale for organoid cultures. Next, we develop a general framework to understand self-organization, tissue hierarchy, and organoid cultivation. For each of these areas, we provide historical context, and review both a wide range of biological and/or biophysical/mathematic perspectives that enhances understanding of organoids. Next, we review existing techniques and progress in hepatobiliary and pancreatic organoid engineering. To do this, we review organoids from both primary tissues, cell lines, and stem cells, and introduce engineering studies when applicable. Noninvasive assessment of 1 organoids can reveal underlying biology and enable improved assays for growth, metabolism, and function. Applications of organoid for cell therapy are also discussed. Taken together, we establish a broad strong scientific foundation for organoids and provide an in-depth review of hepatic, biliary and pancreatic organoids.

scholarly journals Dynamic loading of human engineered heart tissue enhances contractile function and drives a desmosome-linked disease phenotype

2021 ◽  
Vol 13 (603) ◽  
pp. eabd1817
Author(s):  
Jacqueline M. Bliley ◽  
Mathilde C. S. C. Vermeer ◽  
Rebecca M. Duffy ◽  
Ivan Batalov ◽  
Duco Kramer ◽  
...  
Keyword(s):  
Dynamic Loading ◽  
Disease Modeling ◽  
Contractile Function ◽  
Three Dimensional ◽  
Induced Pluripotent Stem Cell ◽  
Heart Tissue ◽  
Disease Phenotype ◽  
Heart Formation ◽  
Induced Pluripotent ◽  
And Function

The role that mechanical forces play in shaping the structure and function of the heart is critical to understanding heart formation and the etiology of disease but is challenging to study in patients. Engineered heart tissues (EHTs) incorporating human induced pluripotent stem cell (hiPSC)–derived cardiomyocytes have the potential to provide insight into these adaptive and maladaptive changes. However, most EHT systems cannot model both preload (stretch during chamber filling) and afterload (pressure the heart must work against to eject blood). Here, we have developed a new dynamic EHT (dyn-EHT) model that enables us to tune preload and have unconstrained contractile shortening of >10%. To do this, three-dimensional (3D) EHTs were integrated with an elastic polydimethylsiloxane strip providing mechanical preload and afterload in addition to enabling contractile force measurements based on strip bending. Our results demonstrated that dynamic loading improves the function of wild-type EHTs on the basis of the magnitude of the applied force, leading to improved alignment, conduction velocity, and contractility. For disease modeling, we used hiPSC-derived cardiomyocytes from a patient with arrhythmogenic cardiomyopathy due to mutations in the desmoplakin gene. We demonstrated that manifestation of this desmosome-linked disease state required dyn-EHT conditioning and that it could not be induced using 2D or standard 3D EHT approaches. Thus, a dynamic loading strategy is necessary to provoke the disease phenotype of diastolic lengthening, reduction of desmosome counts, and reduced contractility, which are related to primary end points of clinical disease, such as chamber thinning and reduced cardiac output.

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