Organoid Technology Research Articles

Abstract 226: Effect of MCL-1 inhibitor on organoids derived from cholangiocarcinoma patients with IDH1 mutation

Abstract Cholangiocarcinomas are highly aggressive malignancies with a poor prognosis. The global incidence of cholangiocarcinoma patients appears to be on the rise. While surgical resection remains the curative option for cholangiocarcinoma patients, the majority of cases are diagnosed at an advanced stage, resulting in poor outcomes. Patients with inoperable cholangiocarcinomas typically undergo chemotherapy regimens, including Gemcitabine, but their efficacy is limited, leading to low 5-year survival rates. Recent advancements in organoid culture technology allow for the in vitro replication of tissue structures by culturing tissue stem cells in three dimensions, offering great promise for personalized medicine. Utilizing patient-derived organoids has proven effective in predicting the outcomes of therapeutic drugs. We have successfully established organoids using cancer tissue derived from cholangiocarcinoma patients, and stably culturing and maintaining them, promoting their application to personalized medicine (Saito Y et al. Cell Rep. 27, 1265, 2019, Saito Y et al. Cancer Cell 40, 226, 2022). IDH1 mutations have been identified in approximately 15% of intrahepatic cholangiocarcinomas and are known to convert α-ketoglutarate (α-KG) in the TCA cycle to produce 2-hydroxyglutarate (2-HG), which is observed in gliomas and acute myeloid leukemia. 2-HG acts as an antagonist to α-KG-dependent dioxygenases, promoting cancer development. This study aims to develop a novel treatment for cholangiocarcinomas with IDH1 mutations. Metabolomic analysis of patient-derived cholangiocarcinoma organoids revealed 2-HG accumulation and reduced ATP production in IDH1-mutated cholangiocarcinoma organoids compared to IDH1 wild-type cholangiocarcinoma organoids. This may suppress the protein synthesis of MCL-1 and mTOR signaling through the activation of AMPK kinase, suggesting that further inhibition of MCL-1 could be lethal in IDH1-mutated cholangiocarcinoma organoids. Indeed, exposure to S63845, an MCL-1 inhibitor, significantly inhibited cell proliferation in IDH1-mutated cholangiocarcinoma organoids, unlike in IDH1 wild-type cholangiocarcinoma organoids. Furthermore, the combination of MCL-1 inhibitor and BCL-XL inhibitor demonstrated a synergistic and potent growth inhibitory effect on cholangiocarcinoma organoids. These findings indicate that the MCL-1 inhibitor holds promise as a new therapeutic agent for cholangiocarcinoma patients with IDH1 mutations. Citation Format: Shiho Suzuki, Juntaro Matsuzaki, Toshihide Muramatsu, Yae Kanai, Yoshimasa Saito. Effect of MCL-1 inhibitor on organoids derived from cholangiocarcinoma patients with IDH1 mutation [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 226.

Abstract 4247: Miniaturizing patient-derived organoid screening assays for predictive drug testing

Abstract Colorectal cancer (CRC) ranks as the third leading cause of both cancer incidence and cancer-related mortality. A significant portion of CRC patients diagnosed with de novo metastatic disease face limited benefits from conventional treatment options, often accompanied by substantial side effects. This underscores the pressing need for more effective preclinical models to predict patient responses in clinical settings. Patient-derived organoids (PDOs or HUB Organoids®) represent a pivotal breakthrough in preclinical modeling. These organoids are directly derived from patient tissue, faithfully mirroring the patient's disease. While HUB Organoid Technology is currently applicable for preclinical drug screening, it is essential to expedite the transition from patient diagnosis to the delivery of PDO-based results to directly benefit patients. In a collaborative effort with Yamaha Motor, we have optimized the Yamaha CELL HANDLERTM for the automated transfer of organoids, offering enhanced precision and efficiency in handling a significantly reduced number of organoids per screening plate, compared to conventional methods. Moreover, we have developed an image-based readout system that enables precise quantification of organoid numbers, ensuring high assay quality. Utilizing this developed automated platform, we conducted a proof-of-concept investigation into PDO responses to chemotherapy in comparison to corresponding patient responses. The correlation between PDO and patient responses demonstrated a strong connection, highlighting the potential of the developed automated platform for predictive drug testing. In summary, this work signifies the development of an automated workflow that synergizes patient-representative HUB Organoids® with cutting-edge robotics from Yamaha Motor. The described workflow reduces the number of organoids needed per screening well, streamlining patient response prediction, potentially leading to faster diagnoses, and ultimately optimizing patient outcomes. Citation Format: Yasmine Abouleila, Roel Verkerk, Mayke Doorn, Timo Voskuilen, Gakuro Harada, Masahiko Watanabe, Lidwien Smabers, Hideaki Kyan, Takahiko Kumagai, Yuichi Hikichi, Rene Overmeer, Jeanine Roodhart, Kiyotaka Matsuno, Carla Verissimo, Sylvia Boj. Miniaturizing patient-derived organoid screening assays for predictive drug testing [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 4247.

Abstract 6724: Mechanistic validation of MAIT cell engagers in HUB patient-derived organoids (PDO) co-culture model

Abstract In the field of cancer immunotherapy, bispecific antibodies have emerged as a promising approach for redirecting T-cells to target and combat tumors. However, their efficacy is limited to only a subset of patients. A major challenge that hinders the development of bispecific antibody targets is the lack of preclinical models that preserve patient-specific tumor antigens and recapitulate the complex interaction between the human immune system and tumor cells. HUB Organoids technology presents a valuable platform for novel immunotherapies testing and validation as they are directly derived from patient tumor tissues, accurately reflecting patient-specific tumor antigens. BIOMUNEX Pharmaceuticals has developed the BiXAb® technology platform, a computational modeling approach that rapidly generates bispecific antibodies from various monospecific monoclonal antibodies, eliminating the need for extensive engineering. This platform includes a bivalent T cell engager specifically targeting MAIT cells and human epithelial growth factor receptor (HER2), a tumor antigen highly expressed in some colorectal cancer (CRC) patients. This innovative approach forms an efficient immunological synapse, allowing exclusive redirection of MAIT cells to directly eliminate cancer cells. In a collaborative research initiative between HUB Organoids® and BIOMUNEX Pharmaceuticals, the mechanisms by which BiXAb® induce tumor cell killing were confirmed using CRC patient-derived organoids (HUB Organoids® or PDOs) co-cultured with allogenic MAIT cells in an in vitro model. The study results depicted BiXAb® induced MAIT-cell activation in a dose-dependent manner, as detected by FACS and ELISA. Furthermore, BiXAb®-mediated MAIT-cell-specific killing of CRC PDOs was observed in a HER2-dependent manner, determined using an image-based viability assay. In conclusion, the co-culture platform of CRC PDOs-MAIT cells described here effectively captured the activation and targeted killing of MAIT cells mediated by BiXAb®, underscoring the added value of this PDO-based co-culture platform in developing novel immunotherapies. Citation Format: Yasmine Abouleila, Julie Prigent, Mayke Doorn, Claire Germain, Sylvia Boj, Simon Plyte, Carla Verissimo. Mechanistic validation of MAIT cell engagers in HUB patient-derived organoids (PDO) co-culture model [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 6724.

Brain organoid protocols and limitations.

Stem cell-derived organoid technology is a powerful tool that revolutionizes the field of biomedical research and extends the scope of our understanding of human biology and diseases. Brain organoids especially open an opportunity for human brain research and modeling many human neurological diseases, which have lagged due to the inaccessibility of human brain samples and lack of similarity with other animal models. Brain organoids can be generated through various protocols and mimic whole brain or region-specific. To provide an overview of brain organoid technology, we summarize currently available protocols and list several factors to consider before choosing protocols. We also outline the limitations of current protocols and challenges that need to be solved in future investigation of brain development and pathobiology.

Integrative Approaches for Advancing Organoid Engineering: From Mechanobiology to Personalized Therapeutics

This research manuscript aims to explore the integration of cutting-edge technologies in the field of organoid engineering for applications in personalized precision medicine. The research investigative exploration will delve into the multifaceted aspects of organoid research, incorporating mechanobiological modulation, ultrasound stimulation, and acoustofluidics to enhance the engineering of organoids. The focus will extend to the development of organoids-on-a-chip platforms with integrated biosensors, providing real-time monitoring capabilities for improved disease modeling and drug testing. Additionally, the manuscript will address the challenges and opportunities associated with large-scale manufacturing of organoids, emphasizing the scalability of regenerative medicine approaches. The proposed research will contribute to the advancement of 3D tissue models, micro physiological systems, and multi-organoid systems, offering a very comprehensive perspective on the potential of these systematic technologies in reshaping the landscape of personalized medicine.

Ultrasound-induced reorientation for multi-angle optical coherence tomography

Organoid and spheroid technology provide valuable insights into developmental biology and oncology. Optical coherence tomography (OCT) is a label-free technique that has emerged as an excellent tool for monitoring the structure and function of these samples. However, mature organoids are often too opaque for OCT. Access to multi-angle views is highly desirable to overcome this limitation, preferably with non-contact sample handling. To fulfil these requirements, we present an ultrasound-induced reorientation method for multi-angle-OCT, which employs a 3D-printed acoustic trap inserted into an OCT imaging system, to levitate and reorient zebrafish larvae and tumor spheroids in a controlled and reproducible manner. A model-based algorithm was developed for the physically consistent fusion of multi-angle data from a priori unknown angles. We demonstrate enhanced penetration depth in the joint 3D-recovery of reflectivity, attenuation, refractive index, and position registration for zebrafish larvae, creating an enabling tool for future applications in volumetric imaging.

Organoids as preclinical models of human disease: progress and applications.

In the field of biomedical research, organoids represent a remarkable advancement that has the potential to revolutionize our approach to studying human diseases even before clinical trials. Organoids are essentially miniature 3D models of specific organs or tissues, enabling scientists to investigate the causes of diseases, test new drugs, and explore personalized medicine within a controlled laboratory setting. Over the past decade, organoid technology has made substantial progress, allowing researchers to create highly detailed environments that closely mimic the human body. These organoids can be generated from various sources, including pluripotent stem cells, specialized tissue cells, andtumor tissue cells. This versatility enables scientists to replicate a wide range of diseases affecting different organ systems, effectively creating disease replicas in a laboratory dish. This exciting capability has provided us with unprecedented insights into the progression of diseases and how wecan develop improved treatments. In this paper, we willprovide an overview of the progress made in utilizing organoids as preclinical models, aiding our understanding and providing a more effective approach to addressing various human diseases.

Biallelic EPCAM deletions induce tissue-specific DNA repair deficiency and cancer predisposition

We report a case of Mismatch Repair Deficiency (MMRD) caused by germline homozygous EPCAM deletion leading to tissue-specific loss of MSH2. Through the use of patient-derived cells and organoid technologies, we performed stepwise in vitro differentiation of colonic and brain organoids from reprogrammed EPCAMdel iPSC derived from patient fibroblasts. Differentiation of iPSC to epithelial-colonic organoids exhibited continuous increased EPCAM expression and hypermethylation of the MSH2 promoter. This was associated with loss of MSH2 expression, increased mutational burden, MMRD signatures and MS-indel accumulation, the hallmarks of MMRD. In contrast, maturation into brain organoids and examination of blood and fibroblasts failed to show similar processes, preserving MMR proficiency. The combined use of iPSC, organoid technologies and functional genomics analyses highlights the potential of cutting-edge cellular and molecular analysis techniques to define processes controlling tumorigenesis and uncovers a new paradigm of tissue-specific MMRD, which affects the clinical management of these patients.

Delivery of a BET protein degrader via a CEACAM6-targeted antibody–drug conjugate inhibits tumour growth in pancreatic cancer models

Pancreatic ductal adenocarcinoma (PDAC) has the worst prognosis of all cancers. To improve PDAC therapy, we establish screening systems based on organoid and co-culture technologies and find a payload of antibody–drug conjugate (ADC), a bromodomain and extra-terminal (BET) protein degrader named EBET. We select CEACAM6/CD66c as an ADC target and developed an antibody, #84.7, with minimal reactivity to CEACAM6-expressing normal cells. EBET-conjugated #84.7 (84-EBET) has lethal effects on various PDAC organoids and bystander efficacy on CEACAM6-negative PDAC cells and cancer-associated fibroblasts. In mouse studies, a single injection of 84-EBET induces marked tumor regression in various PDAC-patient-derived xenografts, with a decrease in the inflammatory phenotype of stromal cells and without significant body weight loss. Combination with standard chemotherapy or PD-1 antibody induces more profound and sustained regression without toxicity enhancement. Our preclinical evidence demonstrates potential efficacy by delivering BET protein degrader to PDAC and its microenvironment via CEACAM6-targeted ADC.

Promising preclinical models for lung cancer research-lung cancer organoids: a narrative review.

Traditional cell line models are the commonly used preclinical models for lung cancer research. However, cell lines cannot recapitulate the complex tumor heterogeneity and cannot mimic the microenvironment of human cancer. Recently, 3D multicellular in vitro self-assembled models called "organoids" have been developed at a fast pace in the field of research, which can mimic the actual primary tumor. At present, several studies have reported on protocols of lung cancer organoids (LCOs) generation, and using LCOs can provide novel insight into the basic and translational research of lung cancer. However, the establishment of the LCO models remains challenging due to the complexity of lung cancer and the immaturity of organoid technology, so it is necessary to understand the influences of different methodologies on LCO generation and review the applications and limitations of LCO models. In this review, we searched the literature in the recent ten years in the field of LCOs. We summarized the methodology, the problems, and the solutions in the LCOs generation, its application and limitations, as well as proposing future challenges and perspectives. Currently, LCOs are successfully generated via exploring the methodology by the researchers. Though there are still challenges in clinical application, LCOs are applied in some cancer studies including investigation of anti-cancer treatment response in vitro, modeling tumor immune microenvironment, and construction of organ chips, which are forging a promising path towards precision medicine.

Retinal Ciliopathies and Potential Gene Therapies: A Focus on Human iPSC-Derived Organoid Models.

The human photoreceptor function is dependent on a highly specialised cilium. Perturbation of cilial function can often lead to death of the photoreceptor and loss of vision. Retinal ciliopathies are a genetically diverse range of inherited retinal disorders affecting aspects of the photoreceptor cilium. Despite advances in the understanding of retinal ciliopathies utilising animal disease models, they can often lack the ability to accurately mimic the observed patient phenotype, possibly due to structural and functional deviations from the human retina. Human-induced pluripotent stem cells (hiPSCs) can be utilised to generate an alternative disease model, the 3D retinal organoid, which contains all major retinal cell types including photoreceptors complete with cilial structures. These retinal organoids facilitate the study of disease mechanisms and potential therapies in a human-derived system. Three-dimensional retinal organoids are still a developing technology, and despite impressive progress, several limitations remain. This review will discuss the state of hiPSC-derived retinal organoid technology for accurately modelling prominent retinal ciliopathies related to genes, including RPGR, CEP290, MYO7A, and USH2A. Additionally, we will discuss the development of novel gene therapy approaches targeting retinal ciliopathies, including the delivery of large genes and gene-editing techniques.

Comparison of endoscopic ultrasound-guided fine-needle aspiration and fine-needle biopsy to generate pancreatic cancer organoids: Randomized trial.

Background and study aims The prognosis for pancreatic cancer remains poor. Molecular diagnostics and customized therapies are becoming increasingly important in clinical routine. Patient-derived, predictive model systems such as organoids have the potential to substantially increase the depth of information from biopsy material by functional and molecular characterization. We compared the extent to which the use of fine-needle aspiration needles (FNA, 22G) or fine-needle biopsy needles (FNB, 22G) influences the generation of pancreatic cancer patient-derived organoids (PDOs) to establish endoscopic standards of organoid technology. Patients and methods Endoscopic ultrasound (EUS)-guided punctures by EUS-FNA and EUS-FNB of pancreatic masses highly suspicious for adenocarcinoma (detected by computed tomography and/or magnetic resonance imaging) were prospectively evaluated. Consecutive patients received EUS-FNA and EUS-FNB in a randomized order without the need to exchange the needle shaft (only the inner needle type (FNA/-B) was exchanged) between the passes. With each needle type, the specimens for histological analysis and for PDOs were obtained separately. Results Fifty patients were enrolled in the study. Histology revealed malignancy in 42 of 50 cases (84%). In total PDOs were generated from 17 patients (34%). Of these, nine were established by FNB only, two by FNA only, and six by both FNA and FNB. Histology revealed malignancy in 13 of 17 PDO cases (76%). In two histologically false-negative cases, PDOs could be established. Conclusions EUS-FNB was superior to EUS-FNA in terms of successful generation of PDOs, although it failed to show statistical significance.

Functional intestinal monolayers from organoids derived from human iPS cells for drug discovery research

BackgroundHuman induced pluripotent stem (iPS) cell-derived enterocyte-like cells (ELCs) are expected to be useful for evaluating the intestinal absorption and metabolism of orally administered drugs. However, it is difficult to generate large amounts of ELCs with high quality because they cannot proliferate and be passaged.MethodsTo solve the issue above, we have established intestinal organoids from ELCs generated using our protocol. Furthermore, monolayers were produced from the organoids. We evaluated the usefulness of the monolayers by comparing their functions with those of the original ELCs and the organoids.ResultsWe established organoids from ELCs (ELC-org) that could be passaged and maintained for more than a year. When ELC-org were dissociated into single cells and seeded on cell culture inserts (ELC-org-mono), they formed a tight monolayer in 3 days. Both ELC-org and ELC-org-mono were composed exclusively of epithelial cells. Gene expressions of many drug-metabolizing enzymes and drug transporters in ELC-org-mono were enhanced, as compared with those in ELC-org, to a level comparable to those in adult human small intestine. The CYP3A4 activity level in ELC-org-mono was comparable or higher than that in primary cryopreserved human small intestinal cells. ELC-org-mono had the efflux activities of P-gp and BCRP. Importantly, ELC-org-mono maintained high intestinal functions without any negative effects even after long-term culture (for more than a year) or cryopreservation. RNA-seq analysis showed that ELC-org-mono were more mature as intestinal epithelial cells than ELCs or ELC-org.ConclusionsWe have successfully improved the function and convenience of ELCs by utilizing organoid technology.

Strategy for Biobanking of Ovarian Cancer Organoids: Addressing the Interpatient Heterogeneity across Histological Subtypes and Disease Stages

While the establishment of an ovarian cancer biobank from patient-derived organoids along with their clinical background information promises advances in research and patient care, standardization remains a challenge due to the heterogeneity of this lethal malignancy, combined with the inherent complexity of organoid technology. This adaptable protocol provides a systematic framework to realize the full potential of ovarian cancer organoids considering a patient-specific variability of progenitors. By implementing a structured experimental workflow to select optimal culture conditions and seeding methods, with parallel testing of direct 3D seeding versus a 2D/3D route, we obtain, in most cases, robust long-term expanding lines suitable for a broad range of downstream applications. Notably, the protocol has been tested and proven efficient in a great number of cases (N = 120) of highly heterogeneous starting material, including high-grade and low-grade ovarian cancer and stages of the disease with primary debulking, recurrent disease, and post-neoadjuvant surgical specimens. Within a low Wnt, high BMP exogenous signaling environment, we observed progenitors being differently susceptible to the activation of the Heregulin 1 ß (HERß-1)-pathway, with HERß-1 promoting organoid formation in some while inhibiting it in others. For a subset of the patient's samples, optimal organoid formation and long-term growth necessitate the addition of fibroblast growth factor 10 and R-Spondin 1 to the medium. Further, we highlight the critical steps of tissue digestion and progenitor isolation and point to examples where brief cultivation in 2D on plastic is beneficial for subsequent organoid formation in the Basement Membrane Extract type 2 matrix. Overall, optimal biobanking requires systematic testing of all main conditions in parallel to identify an adequate growth environment for individual lines. The protocol also describes the handling procedure for efficient embedding, sectioning, and staining to obtain high-resolution images of organoids, which is required for comprehensive phenotyping.

Advances and Challenges in Cerebral Organoids Research

Cerebral organoids are three‐dimensional (3D) aggregates with a more advanced composition, maturation, and architecture. It has emerged as a novel and sophisticated model system for studying neurodevelopment and neurological disorders, in comparison to conventional two‐dimensional (2D) cell cultures. However, due to the extraordinarily complex nature of brain development, current cerebral organoids are not as functional and mature as brains. The development of cerebral organoids requires a culture system with sufficient developmental patterning factors, essential cell components, and vasculature. In this review, the critical factors and events that contribute to the development of cerebral organoids are focused on. The advanced design, fabrication techniques, and technologies are also discussed to enhance the application potential of cerebral organoid technology.

A microfluidic platform integrating functional vascularized organoids-on-chip

The development of vascular networks in microfluidic chips is crucial for the long-term culture of three-dimensional cell aggregates such as spheroids, organoids, tumoroids, or tissue explants. Despite rapid advancement in microvascular network systems and organoid technologies, vascularizing organoids-on-chips remains a challenge in tissue engineering. Most existing microfluidic devices poorly reflect the complexity of in vivo flows and require complex technical set-ups. Considering these constraints, we develop a platform to establish and monitor the formation of endothelial networks around mesenchymal and pancreatic islet spheroids, as well as blood vessel organoids generated from pluripotent stem cells, cultured for up to 30 days on-chip. We show that these networks establish functional connections with the endothelium-rich spheroids and vascular organoids, as they successfully provide intravascular perfusion to these structures. We find that organoid growth, maturation, and function are enhanced when cultured on-chip using our vascularization method. This microphysiological system represents a viable organ-on-chip model to vascularize diverse biological 3D tissues and sets the stage to establish organoid perfusions using advanced microfluidics.

Precision Medicine in Parkinson's Disease Using Induced Pluripotent Stem Cells.

Parkinson's disease (PD) is one of the most devastating neurological diseases; however, there is no effective cure yet. The availability of human induced pluripotent stem cells (iPSCs) provides unprecedented opportunities to understand the pathogenic mechanism and identification of new therapy for PD. Here a new model system of PD, including 2D human iPSC-derived midbrain dopaminergic (mDA) neurons, 3D iPSC-derived midbrain organoids (MOs) with cellular complexity, and more advanced microphysiological systems (MPS) with 3D organoids, is introduced. It is believed that successful integrations and applications of iPSC, organoid, and MPS technologies can bring new insight on PD's pathogenesis that will lead to more effective treatments for this debilitating disease.

Cryopreservation of organoids: Strategies, innovation, and future prospects.

Organoid technology has demonstrated unique advantages in multidisciplinary fields such as disease research, tumor drug sensitivity, clinical immunity, drug toxicology, and regenerative medicine. It will become the most promising research tool in translational research. However, the long preparation time of organoids and the lack of high-quality cryopreservation methods limit the further application of organoids. Although the high-quality cryopreservation of small-volume biological samples such as cells and embryos has been successfully achieved, the existing cryopreservation methods for organoids still face many bottlenecks. In recent years, with the development of materials science, cryobiology, and interdisciplinary research, many new materials and methods have been applied to cryopreservation. Several new cryopreservation methods have emerged, such as cryoprotectants (CPAs) of natural origin, ice-controlled biomaterials, and rapid rewarming methods. The introduction of these technologies has expanded the research scope of cryopreservation of organoids, provided new approaches and methods for cryopreservation of organoids, and is expected to break through the current technical bottleneck of cryopreservation of organoids. This paper reviews the progress of cryopreservation of organoids in recent years from three aspects: damage factors of cryopreservation of organoids, new protective agents and loading methods, and new technologies of cryopreservation and rewarming.

Neuroimmune mechanisms in autism etiology - untangling a complex problem using human cellular models.

Autism spectrum disorder (ASD) affects 1 in 36 people and is more often diagnosed in males than in females. Core features of ASD are impaired social interactions, repetitive behaviors and deficits in verbal communication. ASD is a highly heterogeneous and heritable disorder, yet its underlying genetic causes account only for up to 80% of the cases. Hence, a subset of ASD cases could be influenced by environmental risk factors. Maternal immune activation (MIA) is a response to inflammation during pregnancy, which can lead to increased inflammatory signals to the fetus. Inflammatory signals can cross the placenta and blood brain barriers affecting fetal brain development. Epidemiological and animal studies suggest that MIA could contribute to ASD etiology. However, human mechanistic studies have been hindered by a lack of experimental systems that could replicate the impact of MIA during fetal development. Therefore, mechanisms altered by inflammation during human pre-natal brain development, and that could underlie ASD pathogenesis have been largely understudied. The advent of human cellular models with induced pluripotent stem cell (iPSC) and organoid technology is closing this gap in knowledge by providing both access to molecular manipulations and culturing capability of tissue that would be otherwise inaccessible. We present an overview of multiple levels of evidence from clinical, epidemiological, and cellular studies that provide a potential link between higher ASD risk and inflammation. More importantly, we discuss how stem cell-derived models may constitute an ideal experimental system to mechanistically interrogate the effect of inflammation during the early stages of brain development.

Modelling neurodegeneration and inflammation in early diabetic retinopathy using 3D human retinal organoids

PurposeDiabetic retinopathy (DR) is a complication of diabetes and a primary cause of visual impairment amongst working-age individuals. DR is a degenerative condition in which hyperglycaemia results in morphological and functional changes in certain retinal cells. Existing treatments mainly address the advanced stages of the disease, which involve vascular defects or neovascularization. However, it is now known that retinal neurodegeneration and inflammation precede these vascular changes as early events of DR. Therefore, there is a pressing need to develop a reliable human in vitro model that mimics the early stage of DR to identify new therapeutic approaches to prevent and delay its progression.MethodsHere, we used human-induced pluripotent stem cells (hiPSCs) differentiated into three-dimensional (3D) retinal organoids, which resemble the complexity of the retinal tissue. Retinal organoids were subjected to high-glucose conditions to generate a model of early DR.ResultsOur model showed well-established molecular and cellular features of early DR, such as (i) loss of retinal ganglion and amacrine cells; (ii) glial reactivity and inflammation, with increased expression of the vascular endothelial-derived growth factor (VEGF) and interleukin-1β (IL-1β), and monocyte chemoattractant protein-1 (MCP-1) secretion; and (iii) increased levels of reactive oxygen species accompanied by activation of key enzymes involved in antioxidative stress response.ConclusionThe data provided highlight the utility of retinal organoid technology in modelling early-stage DR. This offers new avenues for the development of targeted therapeutic interventions on neurodegeneration and inflammation in the initial phase of DR, potentially slowing the disease’s progression.