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At least 19 recordsLinked to original sources

Comparative Multiomics Analysis of Cerebral Organoid-Derived Exosomes during Organoid Maturation.

Cerebral organoids derived from human pluripotent stem cells recapitulate key features of early brain development and provide a physiologically relevant model for neurogenesis. Exosomes secreted by these organoids carry bioactive cargo and offer a noninvasive means to monitor maturation and intercellular communication. We performed comprehensive multiomics profiling of exosomes collected from cerebral organoids at defined developmental stages to evaluate their utility as biomarkers of neuronal differentiation. Metabolomic analysis revealed a progressive decline in amino acids, including glutamic acid, consistent with increased metabolic demand during neurogenesis. Lipidomic and neurosteroid profiling showed dynamic increases in phosphatidylethanolamine and pregnenolone, reflecting synaptic membrane formation and signaling. Transcriptomic and proteomic analyses identified stage-specific neurodevelopmental signatures, with key markers mirroring those of parent organoids. Collectively, cerebral organoid-derived exosomes faithfully reflect organoid maturation and provide a robust platform for tracking in vitro brain development.

Humans↗

Establishment and Characterization of Patient-Derived Xenograft Organoids for Personalized Treatment of Castration-Resistant Prostate Cancer.

BACKGROUND: Basic research on castration-resistant prostate cancer (CRPC) is limited by the lack of clinically relevant models. This study aimed to establish patient-derived xenografts (PDX) and PDX-derived organoids from clinical CRPC specimens to develop a bidirectional experimental platform for in vivo xenografts and ex vivo organoids. METHODS: We established a new PDX library (KUCaP PDX series) using CRPC clinical specimens and derived prostate cancer organoids. Comprehensive biological characterization of clinical specimens, PDXs, PDX-derived organoids, and organoid-derived xenografts (ODXs) was performed to confirm the preservation of the original tumor features. Using our PDX library, we conducted genetic engineering and drug testing to explore novel therapeutic approaches. RESULTS: PDX-derived organoids were successfully established from all eight KUCaP PDX lines (100%). Four of the eight lines (50%) were maintained during the long-term culture experiments for over ten passages. Key features observed in the original clinical specimens, including genetic alterations and castration responsiveness, were maintained across the PDX, PDX-derived organoid, and ODX models. RNA sequencing revealed that transcriptomic profiles were consistently maintained across clinical specimens, PDXs, PDX-derived organoids, and ODXs. One PDX and organoid (KUCaP19) which exhibited a high homologous recombination deficiency (HRD) score, without any pathogenic homologous recombination repair (HRR) gene alterations, showed sensitivity to a poly ADP-ribose polymerase (PARP) inhibitor. In contrast, KUCaP12, which had no HRR alterations and a low HRD score, did not respond to PARP inhibition. CONCLUSIONS: We developed the KUCaP library as a novel experimental platform for CRPC research by integrating clinical specimens with PDX, organoid, and ODX models along with their genomic and transcriptomic data. These models largely retained the genetic profiles and responses to castration observed in the original tumors. The bidirectional use of personalized PDX and organoids will facilitate the elucidation of the molecular mechanisms of CRPC.

Male↗

Characteristics of bovine parathyroid cell organoids in culture.

Adult bovine parathyroid glands were enzymatically dispersed and groups of 2 to 5 million cells were reassociated into multicellular aggregates (organoids) by rotation in roller tubes in serum-free medium. Fifty to seventy percent of the seeded cells were incorporated into each organoid at 3 d of culture, and in a typical experiment where DNA content was assayed before and after culture 49 +/- 3% of the original seeded DNA was present after 19 d of culture. No significant differences in DNA content were observed between experimental groups at any time of culture. The morphology of the cells in organoids was similar to that of cells in fresh tissue as determined by light and electron microscopy. The organoids secreted intact parathyroid hormone (PTH) and COOH-terminal hormone fragments which were similar to those released from monolayer cell cultures. Organoids maintained the ability to modulate PTH secretion in response to extracellular calcium for over 2 wk in culture. Each organoid was cultured separately and secreted PTH such that the mean standard deviation of secretion within groups on a per organoid basis was 16.3% of the mean. Using a perifusion system to study acute regulation over a 2-wk period of culture, PTH secretion was suppressed 58 +/- 4% by 2.5 mM compared to that at 0.25 mM calcium. To examine PTH secretion over a range of calcium concentrations, the perifusion system was used to apply 4-h linear gradients of decreasing calcium to fresh tissue slices and to organoids. The results indicated that the calcium (ionized) concentration at 50% secretory suppression (set-point) were 1.30 +/- 0.11 and 1.20 +/- 0.9 mM for the organoids and slices, respectively. Acute secretory control by calcium decreased after 14 d and was not detectable at 22 d of culture. The results demonstrated that the organoids maintained their differentiated function and tissuelike morphology for extended periods in vitro and therefore represent a suitable model system for studies on the long-term modulation of PTH secretion by vitamin D metabolites, ions, and other agents.

Animals↗

Organoids direct systemic expression of erythropoietin in mice.

Organoids are adenoviral vector transduced cells embedded ex vivo in a collagen-polytetrafluoroethylene lattice that is saturated with angiogenic factors. Organoids provide an alternative method of cell mediated gene transfer following implantation in the donor/recipient. The feasibility of adenovirally mediated delivery via organoids using the erythropoietin (Epo) cDNA was tested. Fibroblasts were transduced by two recombinant adenoviral vectors encoding the Macaca cynomolgus Epo cDNA, driven by a viral (RSV LTR) or a murine housekeeping gene promoter (PGK-1). A functional in vivo assay was used to monitor Epo production via the rise in hematocrit(s) (hct). The hct remained elevated for as long as 6 weeks after implantation. Subcutaneous implants gave consistently higher hct than intraperitoneal implants, while organoids made with a greater number of cells, or an equal number of cells transduced at higher multiplicities of infection (MOI) also produced a larger increase in hct. AdPGKEpo-organoids produced a greater increase in hct than AdRSVEpo-organoids under comparable conditions, but the duration of expression was similar. A 10- to 50-fold lower input of AdRSVEpo using organoids versus direct intravenous injections resulted in an equal to, or greater than hct response in mice. Explanted organoids caused a rapid decrease in the hct of mice. Organoid supernatant had little or no detectable free viral particles making this method safe from unwanted recombinant adenovirus dissemination.

Animals↗

Intestinal organoid screen reveals that Bacillus velezensis PGM541 promotes epithelial proliferation via its metabolite butyric acid.

BACKGROUND: Probiotics have been widely used for the regulation of intestinal health. Current screening methods for probiotics typically rely on animal or two-dimensional cell models. In this study, we employed intestinal organoids to identify a candidate probiotic strain. Furthermore, we investigated the potential mechanisms through which this strain and its active metabolites exert their effects, thereby evaluating the efficacy of this screening approach. RESULTS: Firstly, candidate probiotic strain PGM541 was identified from a porcine-derived Bacillus library by assessing organoid viability. Subsequently, to validate the organoid screening reliability, the potential mechanism of strain PGM541 on the intestinal epithelium was investigated; it was found to exhibit probiotic functions by regulating cell proliferation in both in vitro organoid and in vivo piglet models. Furthermore, organoid screening combined with metabolomic analysis identified butyric acid (BA) as the key bioactive metabolite responsible for driving epithelial proliferation. Whole-genome and transcriptomic analyses revealed the biosynthetic pathway of BA in strain PGM541. Importantly, BA receptor blockade experiments directly confirmed that BA enhances epithelial proliferation via interaction with the FFAR2 receptor, thereby validating its functional activity. Additionally, strain PGM541 exhibited protective effects against dextran sulfate sodium (DSS)-induced colitis, further validating the effectiveness of the intestinal organoid platform for probiotic screening. CONCLUSIONS: The probiotic strain PGM541, which was screened using intestinal organoids, promotes intestinal epithelial cell proliferation via its metabolite BA activating the FFAR2 receptor. These findings demonstrate that the intestinal organoid model serves as an effective platform for both preliminary probiotic screening and mechanistic investigation. Video Abstract.

Animals↗

Induction of the endogenous whey acidic protein (Wap) gene and a Wap-myc hybrid gene in primary murine mammary organoids.

In rodents, the whey acidic protein (Wap) is the major whey protein expressed in mammary glands in response to lactogenic hormones. The regulation of the Wap gene differs from that of other milk protein genes, with one consequence being that little or no Wap expression is detectable in cell culture. Here we describe the efficient in vitro induction of the Wap gene in mammary organoids isolated from midpregnant mice. Mammary organoids were isolated as intact epithelial subcomponents which retained the glandular microarchitecture. If organoids were cultured in contact with a monolayer of 3T3-L1 adipocytes, significant levels of Wap mRNA were induced upon hormonal stimulation, with the highest level of Wap mRNA being induced by a combination of hydrocortisone, prolactin, and insulin. Dissociation of the three-dimensional organization abrogated Wap inducibility. Organoids cultured on plastic or hydrated type I collagen did not transcribe Wap mRNA even after hormonal stimulation. Addition of hormones was required to maintain low levels of Wap mRNA in organoids cultured on reconstituted basement membrane, however, Wap mRNA was not induced. Organoid-adipocyte interactions as well as cell-cell interactions inherent in the structure of organoids promote hormone-dependent Wap mRNA expression. In order to study the Wap promoter region in vitro, we cocultured organoids from transgenic mice harboring a chimeric Wap-myc gene with 3T3-L1 adipocytes. Lactogenic hormones induced the Wap-myc transgene in vitro. The kinetics of induction were similar for both the transgene and the endogenous Wap gene indicating that the 2.5-kb regulatory Wap region present in the hybrid gene contains the sequence elements required for hormone-induced gene expression in vitro.

Adipose Tissue↗

Cardiovascular Organoids With Adjustable Endothelial Composition via SOX17-Engineered hPSCs.

Organoids are considered a novel modeling platform for studying human biology and advancing health research. With the ability to demonstrate complex 3D structure and multicellular interactions, organoids have advanced studies in all major organs as a reliable model. In this study, we generated an advanced cardiovascular organoid by using a genome-edited human pluripotent stem cell line with inducible SOX17 expression, enabling controlled endothelial specification, adjustable cell-type composition, and human heart-like morphology. Our organoids recapitulated the cardiotoxic phenotypes of FDA-approved chemotherapeutic doxorubicin, manifesting as decreased cell viability and diminished contractile activity. Cryoinjury-induced myocardial infarction in our organoids led to reduced beating, viability, and α-actinin expression, along with increased fibroblast formation, which were mitigated by Captopril. Lastly, isoproterenol treatment increased peak Ca2+ transient amplitude and shortened APD50 in our organoids, consistent with previously reported β-adrenergic responses. In summary, we established a protocol for generating in vitro 3D cardiovascular organoids with controllable cellular composition and heart-like structures, providing a robust and easy-to-produce platform for future studies of human heart disease.

Humans↗

Single-cell transcriptomics reveals that air-liquid interface culture promotes goblet cell differentiation and inhibits glycolysis in organoid cell monolayers.

Faithfully recapitulating the cellular heterogeneity of the intestinal epithelium is essential when using organoid models. Air-liquid interface (ALI) culture has been shown to promote secretory cell differentiation, but its impact on gene expression in each epithelial cell type remains unclear. In this study, we used single-cell RNA sequencing (scRNA-seq) to characterize the cellular heterogeneity of rabbit cecum-derived organoid monolayers grown under immerged or ALI conditions. We then compared these organoid cell type-specific gene expression profiles to a scRNA-seq atlas of the rabbit cecal epithelium in vivo. We selected the rabbit model notably because, unlike mice, it possesses BEST4+ epithelial cells, a newly discovered subset of mature absorptive cells. Our analysis revealed a high degree of transcriptomic similarity between in vivo and organoid-derived stem and transit-amplifying cells. ALI culture markedly enhanced the differentiation of the secretory lineage, especially goblet cells, whose transcriptome closely resembled that of in vivo goblet cells. Furthermore, ALI was the only condition allowing the detection of enteroendocrine cells. BEST4+ cells, however, were absent from organoids in immerged or ALI conditions despite their presence in vivo. In addition, ALI culture led to a consistent downregulation of hypoxia and glycolysis-associated genes across all cell types, which suggests a metabolic shift likely driven by increased oxygen availability in ALI conditions. Cell-cell communication analyses further indicated that ALI more closely mirrored in vivo patterns than immerged condition. Altogether, these results demonstrate that ALI culture allows for better recapitulation of the in vivo cellular heterogeneity and molecular signatures of the intestinal epithelium.NEW & NOTEWORTHY Using single-cell RNA sequencing, this study shows that air-liquid interface (ALI) culture enhances secretory lineage differentiation of intestinal organoid cell monolayers and improves transcriptomic similarity to the native epithelium. ALI reduced hypoxia-associated gene expression and better recapitulates in vivo-like cell-cell interactions, supporting its value for modeling intestinal epithelial heterogeneity in organoids.

Animals↗

Patient-derived organoids predict responses to chemotherapy and PARP inhibitors in advanced ovarian cancer.

BACKGROUND: While tumor organoids hold promise for personalized medicine, clinical validation of epithelial ovarian cancer (EOC) organoids as predictors of therapeutic efficacy-particularly for PARP inhibitors (PARPi)-remains unestablished. METHODS: Patient-derived organoids (PDOs) were established from treatment-naive EOC specimens and characterized by H&E staining, immunohistochemistry, and whole-exome sequencing. Drug sensitivity testing (DST) was performed using carboplatin, paclitaxel, and PARPi (olaparib and niraparib). Clinical homologous recombination deficiency (HRD) status was assessed by tumor sequencing. Organoid responses were prospectively compared to patient outcomes after first-line chemotherapy (carboplatin/paclitaxel) and PARPi maintenance. RESULTS: PDOs were successfully established from 21 of 30 patients (70%) across multiple EOC subtypes and preserved the histopathological features and genomic landscapes of their corresponding primary tumors. Organoid-based DST accurately predicted responses to first-line carboplatin/paclitaxel, with a sensitivity of 100% (95% CI 62.88-100%), specificity of 66.67% (95% CI 12.53-98.23%), accuracy of 91.67% (95% CI 61.52-99.79%), AUC of 0.95 (95% CI 0.85-1.00), and Cohen's kappa of 0.75 (95% CI 0.30-1.00). In evaluating PARPi response, organoids revealed discrepancies between genomic HRD status and actual drug responses. One HRD-positive PDO was PARPi-resistant, consistent with patient non-response, while two HRR-proficient PDOs showed PARPi sensitivity and corresponding clinical benefit. CONCLUSIONS: EOC-derived PDOs provide a robust platform for predicting chemotherapy response and offer added value in assessing PARPi efficacy beyond genomic profiling. Combination of organoid-based testing with genomic analysis may improve precision treatment strategies in EOC.

Humans↗

The pathobiology of salivary gland. I. Growth and development of rat submandibular gland organoids cultured in a collagen gel matrix.

Fragments of rat submandibular gland (organoids) which maintained the topological organization of the parent tissue were cultured in a three-dimensional collagen gel matrix for up to 30 days. At 48 h, vigorous peripheral outgrowth had occurred around each organoid. This was accompanied by central necrosis and the bridging of adjacent organoids. By day 5, large cyst-like spaces occupied the centre of many organoids. Bromodeoxyuridine labelling indicated that a considerable proportion of the lining cells were proliferating. Organoid growth peaked at between 5 and 10 days. Thereafter, the number of viable colonies and proliferating cells declined. Addition of isoproterenol after 24 h culture resulted in marked morphological alterations, with earlier and more prolific outgrowth and a greater tendency for organoids to flatten and grow out over the surface of the gel with squamous differentiation. Ultrastructurally, nuclear and cytoplasmic features of isoproterenol-treated and untreated cultures were similar. The secretory granules and extensive rough endoplasmic reticulum of terminal tubule cells, evident in organoids immediately after isolation, were infrequent after 24 h and absent by 48 h. Similar alterations occurred in the few acinar cells, so by 5 days the cultures were composed entirely of a uniform population of primitive, dedifferentiated cells. Further uses of this culture systems will include the study of diseases and disorders of the salivary glands as well as normal growth and differentiation pathways.

Animals↗

[Organoid forming method--a new in vitro chemosensitivity test].

In 1988, Friedman and coworkers reported a new chemosensitivity test using "organoids" (epithelial cell aggregates) which had a high plating efficiency and short assay period. The authors recognized this test to be useful and studied it experimentally. Human tumor xenografts maintained in the subcutis of BALB/c nu/nu mice were minced into cell aggregates and filtered, then resuspended in enriched NCTC 135 cell culture medium which contained no serum. Petri dishes were coated with a mixture of collagen-I and bovine serum albumin and dried for an hour. The cell aggregates were seeded in these coated dishes and cultured in a condition of low O2 tension (3% O2). Plating efficiency at 24 hours in cultures of three tumors were 20.8 +/- 2.6% on SC-6-JCK (stomach), 37.8 +/- 3.8% on NS-8 (stomach) and 27.2 +/- 1.5% on PAN-1-RITC (pancreas), respectively. The cell number of each organoid increased until 72 hours in culture, although the organoid number of each dish decreased slightly. Flow cytometrical measurement of total DNA content in dishes showed that the amount of human DNA increased more rapidly than that of mouse DNA which was derived from interstitial and infiltrative cells. This culture system appeared to allow a selective growth of epithelial cells. Subsequently, some drug sensitivity was tested using this system. SC-6-JCK tumor is sensitive to mitomycin C (MMC), although resistant to adriamycin (ADM) in a test using nude mice (sc-ip system). Organoids were formed from this tumor and chemosensitivity was tested against MMC and ADM from the viewpoint of change in the organoid number in each dish. After one hour of drug exposure, only a part of the cells in organoids was affected. On the contrary, after an exposure of 24 hours, the ADM-treated group showed the same results as the MMC-treated group. Hence this test was considered to become more appropriate by counting not the organoid number but the total cell number in the dish.

Animals↗

Physical, chemical, and structural properties of human gastric organoid-derived mucus.

The gastric mucus layer protects the epithelium from gastric acid and ingested pathogens. However, studies of human gastric mucus have been limited due to poor accessibility of native human mucus and the abundance of contaminants in these samples. Here, we explored the potential of human gastric organoids as models for mucus production. Immunofluorescence staining confirmed that the organoids produced mucus containing MUC5AC and MUC6. The luminal mucus had viscoelastic properties similar to those of native human gastric mucus, as determined by particle tracking microrheology. To collect organoid-produced gastric mucus, termed bioengineered gastric mucus (BGM), organoids were cultured as monolayers at the air-liquid interface (ALI), and apically secreted mucus was harvested and analyzed by MUC5AC ELISA, proteomics, cryo-field emission scanning electron microscopy (CryoFE-SE), and rheometry. BGM contained high-molecular weight molecules also found in native gastric mucus. Proteomic analysis confirmed that BGM contained MUC5AC, MUC6, MUC1, and other stomach-specific molecules such as pepsin C, trefoil factor 2, and gastrokine. CryoFE-SE showed that both BGM and native mucus had a porous structure and a characteristic honeycomb scaffold. However, the viscosity of the BGM was generally lower than that of native human gastric mucus, and BGM failed to exhibit gelation at low pH. Collectively, these findings demonstrate the potential as well as some limitations of BGM as an accessible model system for human gastric mucus.NEW & NOTEWORTHY We demonstrate the structural and functional similarities of organoid-derived gastric mucus and native mucus collected from human patients. The bioengineered gastric mucus mimics its native counterpart in its proteomic profile and physical architecture. This work highlights the translational potential of organoid-derived mucus for functional investigations of the human gastric mucus layer.

Humans↗

Organoid reorganization of human tumors under in vitro conditions.

In the present study we describe a new method to cultivate human tumors, which allows organoid differentiation under in vitro conditions. Diverse tumors of different origin and various histopathology which had been heterotransplanted to athymic mice were dissociated into single cells and seeded at high cell density onto a membrane filter consisting of cellulose nitrate at the gas-medium interface. Within a few days, the tumor cells reorganized and differentiated into organoid structures which exhibited the typical histological characteristics of the original tissues. Due to the formation of organoid aggregates, which was also previously seen with normal fetal cells, this type of culture has been described as 'organoid culture'. In the case of adenocarcinomas of the lung and the colon including the rectum, glandular structures with central lumina, adjacent microvilli, and junctional complexes were formed. Numerous specific intercellular contacts such as desmosomes and tight junctions occurred as well as interdigitations of adjacent cell membranes. In a tumor of the rectum, a typical brush border differentiated at the surface of the reorganized tumor-tissue aggregate. Epidermoid carcinomas of the head and neck developed structures resembling the spinous layer of the epidermis, exhibiting numerous desmosomes and intracytoplasmic bundles of tonofilaments radiating into the desmosomes. Most tumors produced a fragmentary monolayered or multilayered basal lamina of similar morphological appearance as under in vivo conditions. These results illustrate the organoid reorganization and differentiation of human tumor cells under the experimentally rather simple conditions of the organoid culture systems and clearly demonstrate that this in vitro system comes close to the in vivo situation as far as certain differentiation phenomena are concerned.

Adenocarcinoma↗

Endodermal Organoids Along Two Axes: Single-Organ Fidelity, Inter-Organ Reconstruction, and the Unbuilt Gut-Lung Frontier.

Three-dimensional organoids of the gut, liver, and lung have become mainstream models of human development, disease, and therapy. These organs share an embryonic endodermal origin, yet the field measures their progress inconsistently because the word "maturity" carries two unrelated meanings. Herein, we review the organoid work across all three organs and propose that the two orthogonal axes of advancement be analyzed separately. The first axis is single-organ fidelity. Adult stem cell organoids are faithful but partial, reproducing the adult epithelium of their source tissue with genomic stability yet lacking stromal, vascular, immune, and neural compartments. Human pluripotent stem cell organoids are complete but immature, co-emerging with multiple lineages yet arrested in a fetal-like state. The cost of each limitation is organ-dependent, smallest in the intestine, largest for hepatic drug metabolism, and most spatially defined across the proximal and distal lungs. The second axis is inter-organ reconstruction, where progress is strongly asymmetric. The gut-liver axis is comparatively advanced and sustained by linked organoid and microphysiological systems. The gut-lung axis, by contrast, remains the least-developed frontier, and no such linked organoid has yet been built. We therefore frame it as a proposal, using in vivo and correlative evidence to outline the design principles for such a model. Four bottlenecks recur across both axes: limited vascularization; batch-to-batch variability; organ-skewed immune, microbial, and stromal microenvironments; and unidirectional signaling. We argue that benchmarking models against single-cell developmental atlases and prioritizing construction of the gut-lung frontier should guide the field over the next decade.

Intestines↗

Mammary organoids from immature virgin rats undergo ductal and alveolar morphogenesis when grown within a reconstituted basement membrane.

We have recently described a primary culture system which allows for extensive proliferation and functional differentiation of immature mammary epithelial cells. Herein, these findings are extended to demonstrate that a distinct pattern of ductal and alveolar morphogenesis can be induced within the mammary organoids isolated from virgin female rats and cultured within an Engelbreth-Holm-Swarm sarcoma-derived reconstituted basement membrane under defined serum-free conditions. The lobular and multilobular organoids that emerged resemble the alveoli of the mammary gland in gross form, multicellular architecture, and cytologic and functional differentiation, while the ductal organoids expressed characteristics typical of mammary gland ducts in vivo. The epithelial cells within the alveolar- and duct-like organoids displayed the capability of secreting two morphologically distinct milk products, casein and lipid, into the luminal compartment. The expression of histiotypic morphogenesis and mammary-specific functional differentiation by the cultured mammary organoids proceeded in the absence of a morphologically distinct basal lamina. We illustrate that development highly reminiscent of that which naturally occurs in the mammary gland in vivo can be induced and supported in vitro under defined serum-free conditions. In addition, the methodologies are available to simultaneously monitor mammary organoid morphogenesis, growth, and functional differentiation. This system should serve as a unique model in which the regulation of branching morphogenesis, development, gene expression, and transformation can be examined.

Animals↗

Effects of insulin, hydrocortisone and prolactin on cell morphology, growth and survival of mammary organoids from mid-pregnant mice cultured on collagen gels.

Mammary epithelial organoids consisting of groups of lobular-alveolar acini were prepared from mid-pregnant mice and cultured for 24, 48, 96 and 192 hr on attached collagen gels in the presence of combinations of insulin, hydrocortisone and prolactin. The organoids rapidly attached to the gels and with all the combinations of hormones used colonies of cells spread out as a monolayer from the organoids within 48 hr. Although colony formation continued for up to 192 hr in culture, the maintenance of parental organoid structure after 96 and 192 hr was strongly favoured when hydrocortisone was present in the culture medium. The presence of hydrocortisone produced a dose-dependent increase in the amount of organoid DNA associated with the collagen substratum but decreased the rate of DNA synthesis by the organoids, as measured by the incorporation of labelled thymidine into DNA, in a dose-dependent manner under these conditions. The results suggest that the presence of hydrocortisone minimised the loss of cells from the collagen matrix in these cultures.

Animals↗

HIF-1 signaling contributes to lenvatinib resistance in patient-derived HCC organoids.

Resistance to lenvatinib remains an important limitation in hepatocellular carcinoma treatment. Six patient-derived organoid lines were established and classified as sensitive or resistant according to ex vivo drug responses, retaining histological and immunophenotypic features of matched parental tumors. Resistant organoids showed unchanged ATP activity, whereas sensitive ones exhibited pronounced morphological changes and reduced ATP activity at higher concentrations. Transcriptome sequencing identified 408 upregulated and 269 downregulated genes in resistant versus sensitive organoids, with HIF-1 signaling among altered pathways. In resistant organoids, lenvatinib increased HIF-1α, ANGPT2, and HK3 mRNA, whereas comparable changes were not detected in sensitive organoids. KC7F2 reduced these transcripts and further decreased ATP activity when combined with lenvatinib. In organoid-derived xenografts, this combination suppressed tumor growth and HIF-1 target expression more than lenvatinib alone, indicating HIF-1 signaling contributes to the resistant phenotype and its inhibition may enhance response.

Drug resistance↗

Splice modulation of COL4A5 reinstates collagen IV assembly in an organoid model of Alport syndrome.

Kidney organoids are an emerging tool for disease modeling, especially genetic diseases. Among these diseases, X-linked Alport syndrome (XLAS) is a hematuric nephropathy affecting the glomerular basement membrane (GBM) secondary to pathogenic variations in the COL4A5 gene encoding the α5 subunit of type IV collagen [α5(IV)]. In patients carrying pathogenic variations affecting splicing, the use of antisense oligonucleotides (ASOs) offers immense therapeutic hope. In this study, we develop a framework combining the use of patient-derived cells and kidney organoids to provide evidence of the therapeutic efficacy of ASOs in XLAS patients. Using multiomics analysis, we describe the development of GBM in WT and mutated human kidney organoids. We show that GBM maturation is a dynamic process, which requires long organoid culture. Then, using semi-automated quantification of α5(IV) at basement membranes in organoids carrying the splicing variants identified in patients, we demonstrate the efficacy of ASO treatment for α5(IV) restoration. These data contribute to our understanding of the development of GBM in kidney organoids and pave the way for a therapeutic screening platform for patients.

Nephritis, Hereditary↗