Organoid System Research Articles

Identity and Maturity of iPSC-Derived Oligodendrocytes in 2D and Organoid Systems

Oligodendrocytes originating in the brain and spinal cord as well as in the ventral and dorsal domains of the neural tube are transcriptomically and functionally distinct. These distinctions are also reflected in the ultrastructure of the produced myelin, and the susceptibility to myelin-related disorders, which highlights the significance of the choice of patterning protocols in the differentiation of induced pluripotent stem cells (iPSCs) into oligodendrocytes. Thus, our first goal was to survey the different approaches applied to the generation of iPSC-derived oligodendrocytes in 2D culture and in organoids, as well as reflect on how these approaches pertain to the regional and spatial fate of the generated oligodendrocyte progenitors and myelinating oligodendrocytes. This knowledge is increasingly important to disease modeling and future therapeutic strategies. Our second goal was to recap the recent advances in the development of oligodendrocyte-enriched organoids, as we explore their relevance to a regional specification alongside their duration, complexity, and maturation stages of oligodendrocytes and myelin biology. Finally, we discuss the shortcomings of the existing protocols and potential future explorations.

Modeling HIV-1 infection and NeuroHIV in hiPSCs-derived cerebral organoid cultures.

The human immunodeficiency virus (HIV) epidemic is an ongoing global health problem affecting 38million people worldwide with nearly 1.6million new infections every year. Despite the advent of combined antiretroviral therapy (cART), a large percentage of people with HIV (PWH) still develop neurological deficits, grouped into the term of HIV-associated neurocognitive disorders (HAND). Investigating the neuropathology of HIV is important for understanding mechanisms associated with cognitive impairment seen in PWH. The major obstacle for studying neuroHIV is the lack of suitable in vitro human culture models that could shed light into the HIV-CNS interactions. Recent advances in induced pluripotent stem cell (iPSC) culture and 3D brain organoid systems have allowed the generation of 2D and 3D culture methods that possess a potential to serve as a model of neurotropic viral diseases, including HIV. In this study, we first generated and characterized several hiPSC lines from healthy human donor skin fibroblast cells. hiPSCs were then used for the generation of microglia-containing human cerebral organoids (hCOs). Once fully characterized, hCOs were infected with HIV-1 in the presence and absence of cART regimens and viral infection was studied by cellular, molecular/biochemical, and virological assays. Our results revealed that hCOs were productively infected with HIV-1 as evident by viral p24-ELISA in culture media, RT-qPCR and RNAscope analysis of viral RNA, as well as ddPCR analysis of proviral HIV-1 in genomic DNA samples. More interestingly, replication and gene expression of HIV-1 were also greatly suppressed by cART in hCOs as early as 7 days post-infections. Our results suggest that hCOs derived from hiPSCs support HIV-1 replication and gene expression and may serve as a unique platform to better understand neuropathology of HIV infection in the brain.

Abstract LB434: Rapid and reproducible expansion of rare tumor cells: The R3CE platform for personalized medicine

Abstract We have developed a novel single-cell derived 3D organoid culture platform, Rapid, Reproducible, Rare Cell 3D Expansion (R3CE), capable of generating 3D organoids from solid tumors and normal tissues obtained via surgical tissues and needle biopsies within one week. This method demonstrates over 90% success in banking for at least two passages with over 106 cells across various cancer types, including breast cancer, colorectal cancer, hepatoma cancer, and ovarian cancer. The organoids maintain high fidelity to original tissues, as evidenced by H&E staining, WES, and protein marker analysis across generations. Notably, the R3CE platform can also cultivate circulating tumor cells (CTCs) from peripheral blood. The drug sensitivity profiles of RCE-cultured CTCs closely mirrored clinical outcomes in breast cancer patients. For a patient with stage IV HER2-positive breast cancer, our real-time assay results led to an adjustment in treatment from lapatinib/5-FU to lapatinib/Trastuzumab emtansine (TDM-1), which resulted in substantial clinical improvement. To our knowledge, the R3CE platform is the first 3D organoid system that does not require aggregation or 3D scaffold such as matrigel system. These advancements position the R3CE platform as a promising tool for personalized medicine, offering a rapid and accurate method for drug screening and therapeutic response prediction to guide clinical decision-making in cancer treatment. Citation Format: Wen-Hung Kuo, Yen-Jang Huang, Jia-Yang Chen, Yi-Chun Wu, Chia-Chun Chen, Mark D. Pegram, Ying-Chih Chang. Rapid and reproducible expansion of rare tumor cells: The R3CE platform for personalized medicine [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB434.

Abstract 1384: Highly metastatic PDAC adopts mesenchymal morphology and spatially coordinates endothelial cells with macrophages

Abstract Background: Patients with pancreatic ductal adenocarcinoma (PDAC) often have metastatic disease at diagnosis and are highly resistant to cytotoxic and immunotherapies. Increased presence of myeloid cells, specifically high myeloid-to-T cell ratios, correlates with worse prognoses. However, mechanisms by which myeloid cells regulate cancer invasion and metastasis remain poorly understood. To study the role of immunosuppressive myeloid cells in driving metastasis, we employed murine PDAC models in conjunction with organoid systems and imaging mass cytometry (IMC). Methods: We used two murine cell lines driven by KrasG12D and Trp53R172H under Pdx1-Cre, KPCY 2838c3 and KPCY 6419c5, which exhibit low-metastatic and high-metastatic propensities, respectively. To characterize differences in the metastatic cascade between these cell lines, flow cytometry, histological analysis, and 3D organoid modeling were used. IMC was also used to interrogate the tumor microenvironment and identify spatial relationships. Results: These cell lines were orthotopically injected into syngeneic C57BL/6J mice to generate tumors that naturally metastasize to the liver. Flow cytometry analysis of livers from mice bearing 2838c3 or 6419c5 pancreatic tumors validated the higher propensity for metastasis with the 6419c5 cells (p=0.0484). Furthermore, the steps along the metastatic cascade contrasted significantly between 6419c5 and 2838c3. Highly metastatic PDAC adopted mesenchymal rather than collective invasion, increased intravasation, and more robust metastatic outgrowth. Notably, IMC revealed that highly metastatic PDAC had increased endothelial cell abundance (***p ≤ 0.001), lower cytotoxic CD8+ T cell to CD4+ regulatory T cell ratios (***p ≤ 0.001), and lower M1-like to M2-like tumor associated macrophage (TAM) ratios (*p ≤ 0.05). Furthermore, spatial analysis demonstrated that highly metastatic PDAC excluded lymphocytes from the tumor and situated Arginase-1+ TAMs near Ki67+ tumor cells and CD31+ endothelial cells. In contrast, low-metastatic PDAC had closer lymphocyte proximities to tumor and greater distances between Arginase-1+ TAMs, tumor, and endothelial cells. Conclusions: The highly metastatic PDAC tumor line utilizes mesenchymal invasion, has increased intravasation, and robust metastatic outgrowth compared to the low-metastatic PDAC cells. The TME of the highly metastatic model had disproportionate abundances of T regulatory cells and M2-like macrophages, poor lymphocyte infiltration, and enhanced vascularization. These overabundant M2-like macrophages (Arginase-1+) were also spatially coordinated with proliferating tumor cells and vasculature, suggesting a potential role for macrophages in tumor cell invasion and/or angiogenesis. Citation Format: Nicole E. Gross, Soren Charmsaz, Jae W. Lee, Cheng-Chieh Huang, Alexei G. Hernandez, Sarah M. Shin, Erin M. Coyne, Courtney Cannon, Xuan Yuan, Laura D. Wood, Elizabeth M. Jaffee, Won Jin Ho. Highly metastatic PDAC adopts mesenchymal morphology and spatially coordinates endothelial cells with macrophages [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1384.

Abstract 1842: Global proteomics reveals integrin signaling as a driver of infiltration in glioblastoma

Abstract Background: Glioblastoma (GBM), a notably aggressive brain cancer, presents significant treatment challenges due to its propensity for deep, diffuse infiltration into healthy brain tissue. This trait enables GBM to resist and survive following surgery and conventional adjuvant therapies. Emerging evidence suggests that signaling between GBM stem cells (GSCs) may be instrumental in this invasive behavior. Our study aimed to unravel the intricacies of these intercellular communication networks within glioblastoma by employing comprehensive proteomic profiling across a diverse array of patient-derived GSC lines. Methods: We conducted our study using a sex-stratified cohort comprising 17 patient-derived GSC lines. Proteomic profiling encompassed analyses of both GSC lysates and conditioned media under various oxygen conditions (normoxia at 20% O2, hypoxia at 1% and 0.2% O2). Additionally, we incorporated the glioma cerebral organoid (GLICO) system, facilitating co-cultures of GSCs with human cerebral organoids. For in-depth proteomic analysis, we utilized advanced TMT-based liquid chromatography-tandem mass spectrometry (LC-MS/MS; Q-Exactive, Thermo Fisher). Results: Our findings corroborate that GSCs adhere to the tripartite model of proliferation, invasion, and hypoxic response. A salient discovery was the consistent enrichment of integrin signaling pathways in GSCs under hypoxic conditions. Specifically, we observed a significant association between upregulation in integrin signaling (BIOCARTA_INTEGRIN_PATHWAY) and elevated KRAS activity (SWEET_KRAS_TARGETS_UP: r=0.43, p<0.01), as well as hypoxic responses (WINTER_HYPOXIA_UP: r=0.76, p<0.0001) in GSCs. Notably, in the GLICO model, both integrin signaling and KRAS pathways were markedly upregulated in the presence of GSCs compared to cerebral organoids alone (p<0.05). Conclusions: This research highlights the pivotal role of integrin signaling in mediating the invasive attributes of glioblastoma. The data underscore the importance of further exploring key modulators within the integrin signaling pathway, presenting a promising avenue for the discovery of novel therapeutic targets in glioblastoma treatment. Citation Format: Lennart J. van Winden, Rifat Shahriar Sajid, Okty Abbasi Borhani, Evelyn Rose Kamski-Hennekam, Nakita Gopal, Alberto Leon, Phedias Diamandis. Global proteomics reveals integrin signaling as a driver of infiltration in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1842.

Abstract 4242: Preserving lung cancer patient mutations in 3D organoid models: Advancing cancer research through innovative culture systems

Abstract Lung cancer is one of the most prevalent cancers worldwide. There are currently many anticancer drugs available, but they have numerous issues in terms of treatment, such as drug resistance and recurrence. Culturing systems that can replace a patient's cancer tissue are crucial, and the existing 2D culturing systems have many limitations. Patient-derived cancer organoid culture is the most advanced culture system for understanding mechanism of cancers. Using a 3D organoid culture system, we have successfully established a culture system for lung cancer using biopsy/surgical specimens and malignant effusions, including a long-term culture system. There are two critical indicators to determine the success of 3D organoid culture. One is whether the organoids retain their cancer-specific mutations from patient’s lung cancer tissue, and the second is whether the organoids grow well and can be maintained in long-term culture for more than 20-30 passages. We typically assess gene mutations in EGFR, ALK, ROS, and P53 when evaluating lung cancer organoids. We confirm these mutations when we establish organoids. and currently we have established a total of 127 patient-derived lung cancer organoids. Among the 127 organoids, we completed NGS analysis on 108 of them and validated that 86.5% exhibit similarity when compared to lung cancer tissues. Additionally, we achieved a 100% retention of mutations in the long-term culturing of these organoids. Our studies indicate that patient-derived lung cancer organoids represent a meaningful organoid system for cancer tissue replacement and treatment response in the context of precision cancer medicine. Citation Format: Ji-yeon Park, Seo Rin Gu, Jiyeon Lee, Na-Gyeong Lee, Dojin Choi, Sang Eun Park, Ji Min Kim, Jinguen Rheey. Preserving lung cancer patient mutations in 3D organoid models: Advancing cancer research through innovative culture systems [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4242.

Cholangiocyte Organoids: The New Frontier in Regenerative Medicine for the Study and Treatment of Cholangiopathies.

Cholangiopathies include a group of chronic progressive disorders, affecting the cholangiocytes, the epithelial cells that line the biliary tree, leading to liver parenchymal fibrosis and eventually end-stage liver disease necessitating transplantation. Experimental modeling of these multifactorial cholestatic diseases faces challenges due to the lack of adequate experimental in vitro and in vivo models. A novel approach employs three-dimensional organoid systems that offer several advantages for modeling disease and testing drug response in vitro. Organoids mimic intercellular communication, replicate the architecture of organs, and maintain the cell's original phenotype. Cholangiocyte organoids provide an in vitro model to study the pathogenesis and pharmacotherapeutic treatment of cholangiopathies and show great promise for regenerative therapies. In particular, patient-derived organoids allow personalized medicine approaches and the study of individual disease characteristics. This review highlights the significance of cholangiocyte organoid models in advancing our understanding of cholangiopathies and driving advancements in regenerative medicine strategies.

Toward reproducible tumor organoid culture: focusing on primary liver cancer.

Organoids present substantial potential for pushing forward preclinical research and personalized medicine by accurately recapitulating tissue and tumor heterogeneity in vitro. However, the lack of standardized protocols for cancer organoid culture has hindered reproducibility. This paper comprehensively reviews the current challenges associated with cancer organoid culture and highlights recent multidisciplinary advancements in the field with a specific focus on standardizing liver cancer organoid culture. We discuss the non-standardized aspects, including tissue sources, processing techniques, medium formulations, and matrix materials, that contribute to technical variability. Furthermore, we emphasize the need to establish reproducible platforms that accurately preserve the genetic, proteomic, morphological, and pharmacotypic features of the parent tumor. At the end of each section, our focus shifts to organoid culture standardization in primary liver cancer. By addressing these challenges, we can enhance the reproducibility and clinical translation of cancer organoid systems, enabling their potential applications in precision medicine, drug screening, and preclinical research.

EML4-ALK fusions drive lung adeno-to-squamous transition through JAK-STAT activation.

Human lung adenosquamous cell carcinoma (LUAS), containing both adenomatous and squamous pathologies, exhibits strong cancer plasticity. We find that ALK rearrangement is detectable in 5.1-7.5% of human LUAS, and transgenic expression of EML4-ALK drives lung adenocarcinoma (LUAD) formation initially and squamous transition at late stage. We identify club cells as the main cell-of-origin for squamous transition. Through recapitulating lineage transition in organoid system, we identify JAK-STAT signaling, activated by EML4-ALK phase separation, significantly promotes squamous transition. Integrative study with scRNA-seq and immunostaining identify a plastic cell subpopulation in ALK-rearranged human LUAD showing squamous biomarker expression. Moreover, those relapsed ALK-rearranged LUAD show notable upregulation of squamous biomarkers. Consistently, mouse squamous tumors or LUAD with squamous signature display certain resistance to ALK inhibitor, which can be overcome by combined JAK1/2 inhibitor treatment. This study uncovers strong plasticity of ALK-rearranged tumors in orchestrating phenotypic transition and drug resistance and proposes a potentially effective therapeutic strategy.

Abstract PR007: Patient derived organoids as a model to study estrogen mediated endometrial cancer

Abstract The purpose of our study was to develop a more optimal in vitro model to study the mechanisms of hormone action on endometrial cancer. Endometrial cancer (EC) represents a major health disparity with a 21% increase in mortality in African American women. The cause for this excess mortality is unknown. Endometrial cancer is commonly characterized by histological subtype into Endometrioid or Non-Endometrioid with estrogen being a driver for many endometroid type tumors. Most EC cell lines do not have high expression of estrogen receptor or do not respond to physiological levels of hormones in vitro; this lack of functional experimental models has hampered progress in the study of this disease. We have developed Patient Derived Organoids (PDOs) from 9 patient-derived xenografts (PDX) that are from both African American and Non-Hispanic Caucasian women with various stages and subtypes of EC, as a model to study EC. This model system captures the characteristics of different histological and molecular subtypes in vitro, as they maintain not only EC tumor cells but also cells from the adjacent tumor stroma. Our developed PDOs were derived from multiple molecular subtypes of EC that have different characteristics and genomic features, allowing us to observe differences in the basal properties of each tumor in vitro. The use of this organoid model system is advantageous for studying EC because growth characteristics are similar to an in vivo model, with the organoids preserving the genotype and phenotype of the native EC, allowing us to observe cellular interactions. We have observed inter-organoid variation of protein expression of β-catenin, E-cadherin, and vimentin, proteins playing a pivotal role in cellular contact, signaling, and epithelial-mesenchymal transition (EMT). Using qPCR and Western blot analysis we have observed high expression levels of estrogen receptor and progesterone receptor in endometrioid type PDOs to begin the exploration of hormonal signaling in this model. Treatment of these same PDOs with β-estradiol resulted in an increase in proliferation of the stromal cells. Single cell RNA sequencing was performed on two PDO’s that had the highest expression of progesterone and estrogen receptors. This analysis demonstrated cell population heterogeneity with multiple cell clusters forming with differential gene expression. From this analysis we can see that the cells recapitulate the gene expression from the tumor of origin, with cells containing the same genetic mutation as the original patient. These results make this model potentially good for studying hormone signaling cascades seen in EC patients that have not been previously observed in established EC cell lines. These studies will also aid in the opportunity to explore the function of differential cell types in the pathogenesis of this disease. Citation Format: Breanna M.W. Jeffcoat, Andrew B. Galdden, Russell R. Broaddus. Patient derived organoids as a model to study estrogen mediated endometrial cancer [abstract]. In: Proceedings of the AACR Special Conference on Endometrial Cancer: Transforming Care through Science; 2023 Nov 16-18; Boston, Massachusetts. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(5_Suppl):Abstract nr PR007.

Trophoblast organoid systems to study human placentation

Human trophoblast organoids provide a valuable invitro system to investigate human placental development and function. In this issue of Developmental Cell, Shannon etal. benchmark two organoid models against primary trophoblast at single-cell resolution, identifying their strengths and limitations.

CRISPR/Cas9-Based Disease Modeling and Functional Correction of Interleukin 7 Receptor Alpha Severe Combined Immunodeficiency in T-Lymphocytes and Hematopoietic Stem Cells.

Interleukin 7 Receptor alpha Severe Combined Immunodeficiency (IL7R-SCID) is a life-threatening disorder caused by homozygous mutations in the IL7RA gene. Defective IL7R expression in humans hampers T cell precursors' proliferation and differentiation during lymphopoiesis resulting in the absence of T cells in newborns, who succumb to severe infections and death early after birth. Previous attempts to tackle IL7R-SCID by viral gene therapy have shown that unregulated IL7R expression predisposes to leukemia, suggesting the application of targeted gene editing to insert a correct copy of the IL7RA gene in its genomic locus and mediate its physiological expression as a more feasible therapeutic approach. To this aim, we have first developed a CRISPR/Cas9-based IL7R-SCID disease modeling system that recapitulates the disease phenotype in primary human T cells and hematopoietic stem and progenitor cells (HSPCs). Then, we have designed a knockin strategy that targets IL7RA exon 1 and introduces through homology-directed repair a corrective, promoterless IL7RA cDNA followed by a reporter cassette through AAV6 transduction. Targeted integration of the corrective cassette in primary T cells restored IL7R expression and rescued functional downstream IL7R signaling. When applied to HSPCs further induced to differentiate into T cells in an Artificial Thymic Organoid system, our gene editing strategy overcame the T cell developmental block observed in IL7R-SCID patients, while promoting full maturation of T cells with physiological and developmentally regulated IL7R expression. Finally, genotoxicity assessment of the CRISPR/Cas9 platform in HSPCs using biased and unbiased technologies confirmed the safety of the strategy, paving the way for a new, efficient, and safe therapeutic option for IL7R-SCID patients.

Bibliometrics analysis based on the Web of Science: Current trends and perspective of gastric organoid during 2010-2023.

Three-dimensional organoid culture systems have been established as a robust tool for elucidating mechanisms and performing drug efficacy testing. The use of gastric organoid models holds significant promise for advancing personalized medicine research. However, a comprehensive bibliometric review of this bur-geoning field has not yet been published. To analyze and understand the development, impact, and direction of gastric organoid research using bibliometric methods using data from the Web of Science Core Collection (WoSCC) database. This analysis encompassed literature pertaining to gastric organoids published between 2010 and 2023, as indexed in the WoSCC. CiteSpace and VOSviewer were used to depict network maps illustrating collaborations among authors, institutions and keywords related to gastric organoid. Citation, co-citation, and burst analysis methodologies were applied to assess the impact and progress of research. A total of 656 relevant studies were evaluated. The majority of research was published in gastroenterology-focused journals. Globally, Yana Zavros, Hans Clevers, James M Wells, Sina Bartfeld, and Chen Zheng were the 5 most productive authors, while Hans Clevers, Huch Meritxell, Johan H van Es, Marc Van de Wetering, and Sato Toshiro were the foremost influential scientists in this area. Institutions from the University Medical Center Utrecht, Netherlands Institute for Developmental Biology (Utrecht), and University of Cincinnati (Cincinnati, OH, United States) made the most significant contributions. Currently, gastric organoids are used mainly in studies investigating gastric cancer (GC), Helicobacter pylori-infective gastritis, with a focus on the mechanisms of GC, and drug screening tests. Key focus areas of research using gastric organoids include unraveling disease mechanisms and enhancing drug screening techniques. Major contributions from renowned academic institutions highlight this field's dynamic growth.

An in vitro three-dimensional (3D) testicular organoid culture system for efficient gonocyte maintenance and propagation using frozen/thawed neonatal bovine testicular tissues

Fertility preservation in prepubertal boys with cancer requires the cryopreservation of immature testicular tissues (ITTs) prior to gonadotoxic treatment. However, the limited number of germ cells in small human ITT biopsies necessitates the development of an in vitro culture system for germ cell expansion using frozen-thawed ITTs. Here, we generated testicular organoids for the in vitro maintenance and expansion of gonocytes from frozen-thawed two-week-old neonatal bovine ITTs. We investigated the effects of different cell-seeding densities, culture serums, seeding methods, and gonadotropin supplementations, on the maintenance and proliferation of enriched gonocytes. Our results demonstrated that enriched gonocytes and testicular cells from frozen-thawed neonatal ITTs could self-assemble into spheroid organoids in three days in an appropriate Matrigel-based culture environment. For the optimal formation of prepubertal testicular organoids, a seeding density of 1 × 106 cells/well is recommended over other densities. This strategy results in organoids with a mean diameter of 60.53 ± 12.12 μm; the mean number of organoids was 5.57 ± 1.60/105 μm2 on day 11. The viability of organoids was maintained at 79.75 ± 2.99% after being frozen and thawed. Supplementing the culture medium with glial cell-derived neurotrophic factor, fibroblast growth factor 2, and leukemia inhibitory factor, increased the proportion of KI67-positive proliferating cells in organoids, elevated the expression of C-KIT but reduced the expression of GFRα1 at day 28 when compared to those without hormone supplements (p< 0.05). In addition, supplementing the culture medium with follicle-stimulating hormone and testosterone helped to maintain a significantly higher viability (p< 0.05) in ITT organoids at day 28. These organoids could be cryopreserved for storage and thawed as needed. The successful generation of ITT organoids provides a valuable tool for establishing in vitro spermatogenesis, propagating human germ cells, investigating testicular physiology and the origin of germ cell tumors, and testing the toxicity of new drugs in future clinical applications.

ER stress and lipid imbalance drive diabetic embryonic cardiomyopathy in an organoid model of human heart development

Congenital heart defects are the most prevalent human birth defects, and their incidence is exacerbated by maternal health conditions, such as diabetes during the first trimester (pregestational diabetes). Our understanding of the pathology of these disorders is hindered by a lack of human models and the inaccessibility of embryonic tissue. Using an advanced human heart organoid system, we simulated embryonic heart development under pregestational diabetes-like conditions. These organoids developed pathophysiological features observed in mouse and human studies before, including ROS-mediated stress and cardiomyocyte hypertrophy. scRNA-seq revealed cardiac cell-type-specific dysfunction affecting epicardial and cardiomyocyte populations and alterations in the endoplasmic reticulum and very-long-chain fatty acid lipid metabolism. Imaging and lipidomics confirmed these findings and showed that dyslipidemia was linked to fatty acid desaturase 2 mRNA decay dependent on IRE1-RIDD signaling. Targeting IRE1 or restoring lipid levels partially reversed the effects of pregestational diabetes, offering potential preventive and therapeutic strategies in humans.

Live Organoid Cyclic Imaging.

Organoids are becoming increasingly relevant in biology and medicine for their physiological complexity and accuracy in modeling human disease. To fully assess their biological profile while preserving their spatial information, spatiotemporal imaging tools are warranted. While previously developed imaging techniques, such as four-dimensional (4D) live imaging and light-sheet imaging have yielded important clinical insights, these technologies lack the combination of cyclic and multiplexed analysis. To address these challenges, bioorthogonal click chemistry is applied to display the first demonstration of multiplexed cyclic imaging of live and fixed patient-derived glioblastoma tumor organoids. This technology exploits bioorthogonal click chemistry to quench fluorescent signals from the surface and intracellular of labeled cells across multiple cycles, allowing for more accurate and efficient molecular profiling of their complex phenotypes. Herein, the versatility of this technology is demonstrated for the screening of glioblastoma markers in patient-derived human glioblastoma organoids while conserving their viability. It is anticipated that the findings and applications of this work can be broadly translated into investigating physiological developments in other organoid systems.

Mass Spectrometry Imaging of Organoids to Improve Preclinical Research.

Preclinical models are essential research tools before novel therapeutic or diagnostic methods can be applied to humans. These range from in vitro cell monocultures to vastly more complex animal models, but clinical translation to humans often fails to deliver significant results. Three-dimensional (3D) organoid systems are being increasingly studied to establish physiologically relevant in vitro platforms in a trade-off between the complexity of the research question and the complexity of practical experimental setups. The sensitivity and precision of analytical tools are yet another limiting factors in what can be investigated, and mass spectrometry (MS) is one of the most powerful analytical techniques available to the scientific community. Its innovative use to spatially resolve biological samples has opened many research avenues in the field of MS imaging (MSI). Here, this work aims to explore the current scientific landscape in the application of MSI on organoids, with an emphasis on their combined potential to facilitate and improve preclinical studies.

Vascularized 3D Human Skin Models in the Forefront ofDermatological Research.

In vitro engineered skin models are emerging as an alternative platform to reduce and replace animal testing in dermatological research. Despite the progress made in recent years, considerable challenges still exist for the inclusion of diverse cell types within skin models. Blood vessels, in particular, are essential in maintaining tissue homeostasis and are one of many primary contributors to skin disease inception and progression. Substantial efforts in the past have allowed the successful fabrication of vascularized skin models that are currently utilized for disease modeling and drugs/cosmetics testing. This review first discusses the need for vascularization within tissue-engineered skin models, highlighting their role in skin grafting and disease pathophysiology. Second, the review spotlights the milestones and recent progress in the fabrication and utilization of vascularized skin models. Additionally, advances including the use of bioreactors, organ-on-a-chip devices, and organoid systems are briefly explored. Finally, the challenges and future outlook for vascularized skin models are addressed.

REGγ Mitigates Radiation-Induced Enteritis by Preserving Mucin Secretion and Sustaining Microbiome Homeostasis

Radiation-induced enteritis, a significant concern in abdominal radiation therapy, is closely associated with gut microbiota dysbiosis. The critical mucus layer plays a pivotal role in preventing the translocation of commensal and pathogenic microbes. While the significant expression of REGγ in intestinal epithelial cells is well established, its role in modulating mucus layer and gut microbiota remains enigmatic. Current study revealed notable changes in gut microorganisms and metabolites in irradiated mice lacking REGγ, as opposed to wild-type mice. Concomitant with gut microbiota dysbiosis, REGγ deficiency facilitated the infiltration of neutrophils and macrophages, thereby exacerbating intestinal inflammation following irradiation. Furthermore, fluorescence in situ hybridization assays unveiled an augmented proximity of bacteria to intestinal epithelial cells in REGγ knockout mice post-irradiation. Mechanistically, deficiency of REGγ led to diminished goblet cell populations and reduced expression of key goblet cell markers, Muc2 and Tff3, observed in both murine models, mini-gut organoid system and human intestinal goblet cells, indicating the intrinsic role of REGγ within goblet cells. Interestingly, while administration of broad-spectrum antibiotics didn't impact the alteration of goblet cell numbers and MUC2 secretion, it did effectively attenuate inflammation levels in the ileum of irradiated REGγ absent mice, aligning them with their wild-type counterparts. Collectively, these findings highlight the crucial contribution of REGγ in counteracting radiation-triggered microbial imbalances and cell-autonomous regulation of mucin secretion.

Establishment of human cerebral organoid systems to model early neural development and assess the central neurotoxicity of environmental toxins

Abstract Human brain development is a complex process, and animal models often have significant limitations. To address this, researchers have developed pluripotent stem cell-derived three-dimensional structures, known as brain-like organoids, to more accurately model early human brain development and disease. To enable more consistent and intuitive reproduction of early brain development, in this study, we incorporated forebrain organoid culture technology into the traditional unguided method of brain organoid culture. This involved embedding organoids in matrix glue for only 7 days during the rapid expansion phase of the neural epithelium and then removing them from the matrix glue for further cultivation, resulting in a new type of human brain organoid system. This cerebral organoid system replicated the temporospatial characteristics of early human brain development, including neuroepithelium derivation, neural progenitor cell production and maintenance, neuron differentiation and migration, and cortical layer patterning and formation, providing more consistent and reproducible organoids for developmental modeling and toxicology testing. As a proof of concept, we applied the heavy metal cadmium to this newly improved organoid system to test whether it could be used to evaluate the neurotoxicity of environmental toxins. Brain organoids exposed to cadmium for 7 or 14 days manifested severe damage and abnormalities in their neurodevelopmental patterns, including bursts of cortical cell death and premature differentiation. Cadmium exposure caused progressive depletion of neural progenitor cells and loss of organoid integrity, accompanied by compensatory cell proliferation at ectopic locations. The convenience, flexibility, and controllability of this newly developed organoid platform make it a powerful and affordable alternative to animal models for use in neurodevelopmental, neurological, and neurotoxicological studies.