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The extracellular matrix in cartilage organoid culture: biochemical, immunomorphological and electron microscopic studies.

Limb bud mesenchymal cells obtained from day-12 mouse embryos were grown at high density on a membrane filter (pore size 0.2 micron) at the medium/air interphase. Chondrogenesis in this so-called cartilage organoid culture was monitored quantitatively by immunological estimation of type I and type II collagen and qualitatively by indirect immunofluorescence and electron microscopy in the course of a 36 days culture period. Three stages of cartilage development could be substantiated: 1. Formation of cartilage between days 2 and 7; 2. maturation of cartilage between days 9 and 13; 3. degeneration of cartilage beginning at day 20. Differentiation in cell aggregates and a loose mesenchymal tissue occurred during the first two days of the culture period. Type II collagen synthesis started in cell aggregates two days after plating and after 6 days in culture distinct cartilage nodules had developed which were embedded in loose connective tissue that contained type I collagen. During this period the type II collagen content increased progressively from 2.3 micrograms (day 3) to nearly 40 micrograms (day 7) per mg dry weight, whereas the type I collagen level increased more linearly from 2.7 to 21.3 micrograms/mg dry weight. The second period was characterized by enlargement and fusion of cartilage nodules and a diminished increase in type II collagen content from 45 to 60 micrograms/mg dry weight. Enlargement and fusion occurred by matrix production as well as by transformation of perichondrial cells into chondroblasts. Type I collagen synthesis enhanced from 29 to 54 micrograms/mg. Hypertrophic chondrocytes could be demonstrated ultrastructurally. At the third stage a nearly continuous layer of cartilage on the membrane filter covered by noncartilagenous tissue had developed. To some extent chondrocytes lost their matrix capsule and changed into fibroblast-like cells accompanied by a switch of collagen synthesis from type II to type I collagen. Quantitative studies yielded a constant level of about 60 micrograms/mg type II collagen and a further increase in type I collagen from 77 to 116 micrograms/mg dry weight. This study reveals an in vitro model of a prolonged, but almost identical image of chondrogenesis in vivo prior to endochondral mineralization which may be useful for investigations on cartilage differentiation, maturation and degeneration.

Animals↗

Efficient generation of human T cells from a tissue-engineered thymic organoid.

Biocompatible inorganic matrices have been used to enhance bone repair by integrating with endogenous bone architecture. Hypothesizing that a three-dimensional framework might support reconstruction of other tissues as well, we assessed the capacity of a tantalum-coated carbon matrix to support reconstitution of functioning thymic tissue. We engineered a thymic organoid by seeding matrices with murine thymic stroma. Co-culture of human bone marrow-derived hematopoietic progenitor cells within this xenogeneic environment generated mature functional T cells within 14 days. The proportionate T-cell yield from this system was highly reproducible, generating over 70% CD3+ T cells from either AC133+ or CD34+ progenitor cells. Cultured T cells expressed a high level of T-cell receptor excision circles (TREC), demonstrating de novo T lymphopoiesis, and function of fully mature T cells. This system not only facilitates analysis of the T-lymphopoietic potential of progenitor cell populations; it also permits ex vivo genesis of T cells for possible applications in treatment of immunodeficiency.

AC133 Antigen↗

A neovascularized organoid derived from retrovirally engineered bone marrow stroma leads to prolonged in vivo systemic delivery of erythropoietin in nonmyeloablated, immunocompetent mice.

Marrow stromal cells (MSCs) are postnatal progenitor cells that can be easily cultured ex vivo to large amounts. This feature is attractive for cell therapy applications where genetically engineered MSCs could serve as an autologous cellular vehicle for the delivery of therapeutic proteins. The usefulness of MSCs in transgenic cell therapy will rely upon their potential to engraft in nonmyeloablated, immunocompetent recipients. Further, the ability to deliver MSCs subcutaneously - as opposed to intravenous or intraperitoneal infusions - would enhance safety by providing an easily accessible, and retrievable, artificial subcutaneous implant in a clinical setting. To test this hypothesis, MSCs were retrovirally engineered to secrete mouse erythropoietin (Epo) and their effect was ascertained in nonmyeloablated syngeneic mice. Epo-secreting MSCs when administered as 'free' cells by subcutaneous or intraperitoneal injection, at the same cell dose, led to a significant - yet temporary - hematocrit increase to over 70% for 55+/-13 days. In contrast, in mice implanted subcutaneously with Matrigel trade mark -embedded MSCs, the hematocrit persisted at levels >80% for over 110 days in four of six mice (P<0.05 logrank). Moreover, Epo-secreting MSCs mixed in Matrigel elicited and directly participated in blood vessel formation de novo reflecting their mesenchymal plasticity. MSCs embedded in human-compatible bovine collagen matrix also led to a hematocrit >70% for 75+/-8.9 days. In conclusion, matrix-embedded MSCs will spontaneously form a neovascularized organoid that supports the release of a soluble plasma protein directly into the bloodstream for a sustained pharmacological effect in nonmyeloablated recipients.

Animals↗

Hepatocyte attachment on biodegradable modified chitosan membranes: in vitro evaluation for the development of liver organoids.

Extracellular matrix structures including glycosaminoglycans play a critical role in cell attachment, differentiation, and morphogenesis. We evaluated chitosan ([1-->4] linked 2-amino-2-deoxy-beta-D-glucan) as a biomaterial for hepatocyte attachment because of its structural similarity to glycosaminoglycans. Freshly isolated rat and fetal porcine hepatocytes were seeded on chitosan membranes that had been previously blended with collagen, gelatin, or albumin to improve biocompatibility and surface roughness. The optimal cell density and attachment kinetics were quantified. The metabolic activity was investigated by measuring daily urea and total protein secretion by the cells for 2 weeks. While collagen blended-chitosan membranes provided a good attachment surface for rat hepatocytes, albumin and gelatin blended chitosan membranes were superior for fetal porcine hepatocyte attachment. The optimal attachment was maintained with membranes of medium molecular weight (Mr = 750,000 daltons) chitosan, at 3-4 x 10(4) cells/cm2 after 3 h of incubation. In vitro experiments demonstrated that fetal porcine hepatocytes survived at least 14 days when seeded on the chitosan-albumin matrix, demonstrating that this biomaterial can provide suitable cell attachment scaffolds for creating liver tissue organoids.

Albumins↗

Tissue engineering of human salivary gland organoids.

Radiation therapy for malignant head and neck tumours is mainly responsible for inadvertent damage of the salivary glands. Xerostomia is the major symptom of this condition, with consequent mucositis, dental caries, dysphagia and nutritional deficits. At present there is no routine treatment for radiation-induced salivary dysfunction. Based on the principles of tissue engineering, this study presents a new experimental concept for reconstituting salivary gland function after radiation therapy for head and neck cancer. Human parotid cells were cultured with two different types of commercially available microcarriers-Cytodex 3 and Cytopore 1-for up to 3 weeks in vitro. Cultures were controlled daily by means of inverted microscopy. Medium samples were tested for alpha-amylase, tissue polypeptide antigen (TPA) and S100 in order to control parotid cell function in vitro. The vitality of the cells was investigated by in vitro staining with erythrosine. Immunocytochemical analysis for amylase and cytokeratin was performed in order to confirm epithelial character and maintain acinar cell type. Parotid gland cells could be cultured in a differentiated and vital state on both types of microcarriers for up to 3 weeks. Almost all of the cultured cells exhibited immunoreactivity for cytokeratin. High concentrations of TPA, a specific marker for salivary duct epithelium, indicated persistent differentiation of this cell type in vitro. Positivity for amylase was detectable in 20-45%, of cells growing on the microcarriers, and especially on Cytodex 3. Decreasing amylase levels in the culture medium indicated functional deficiencies of the remaining acinar cells. Tissue engineering of human salivary gland organoids on microcarriers is a new approach for potential causative treatment of radiation-induced xerostomia. Before clinical application can be considered significant improvements in the in vitro cultivation of salivary gland tissue and scaffold design have to be realized.

Dextrans↗

Interspecies Organoids Reveal Human-Specific Molecular Features of Dopaminergic Neuron Development and Vulnerability.

The disproportionate expansion of telencephalic structures during human evolution involved tradeoffs that imposed greater connectivity and metabolic demands on midbrain dopaminergic neurons. Despite the central role of dopaminergic neurons in human-enriched disorders, molecular specializations associated with human-specific features and vulnerabilities of the dopaminergic system remain unexplored. Here, we establish a phylogeny-in-a-dish approach to examine gene regulatory evolution by differentiating pools of human, chimpanzee, orangutan, and macaque pluripotent stem cells into ventral midbrain organoids capable of forming long-range projections, spontaneous activity, and dopamine release. We identify human-specific gene expression changes related to axonal transport of mitochondria and reactive oxygen species buffering and candidate cis- and trans-regulatory mechanisms underlying gene expression divergence. Our findings are consistent with a model of evolved neuroprotection in response to tradeoffs related to brain expansion and could contribute to the discovery of therapeutic targets and strategies for treating disorders involving the dopaminergic system.

Brain evolution↗

Targeting cancer stem cells predicts response and reverses chemoresistance in ascites-derived ovarian cancer organoids.

BACKGROUND: Ovarian cancer (OC) is frequently diagnosed at an advanced stage, where tumor heterogeneity and rapid development of chemoresistance contribute to a poor prognosis. The lack of reliable predictive biomarkers further hinders the development of effective treatment strategies. Patient-derived organoids (PDOs) have recently emerged as promising preclinical models with the potential to predict therapeutic responses. METHODS: OC PDOs were generated from ascites samples representing diverse histological subtypes. Histological and genomic fidelity to parental tumors was confirmed through histopathological analysis and whole-exome sequencing. Drug sensitivity to cisplatin and poly (ADP-ribose) polymerase (PARP) inhibitors was evaluated and correlated with 1-year clinical outcomes. We also investigated the therapeutic efficacy of oncolytic herpes simplex virus 2 (OH2) both as a single agent and in combination with cisplatin. The expression of cancer stem cell (CSC) markers CD44 and ALDH1A1 under treatment conditions was analyzed using immunohistochemistry and flow cytometry. RESULTS: PDOs were successfully established with an 86.2% success rate. These PDOs faithfully recapitulated the histopathological and genomic features of their corresponding tumors, maintaining intratumoral heterogeneity, and were amenable to xenotransplantation. Drug sensitivity assays demonstrated that PDOs accurately predicted patient-specific responses to cisplatin and PARP inhibitors. OH2 exhibited direct cytotoxicity in both cisplatin-sensitive and cisplatin-resistant PDOs, reducing cell viability by 20-60%. Notably, the combination treatment with OH2 and cisplatin enhanced antitumor efficacy, resulting in a significant reduction of the CD44+CSC subpopulation. CONCLUSIONS: Ascites-derived OC PDOs represent a robust platform for individualized drug testing. The combination of OH2 and cisplatin offers a novel and effective strategy for circumventing chemoresistance in OC.

Female↗

[Relationship between the volume and proportions of the organoids and cell volume in yeasts].

Populations of yeast Saccharomyces carlsbergensis and Candida quilliermondii were divided into cell classes with different volumes. In each class volumes of nuclei, vacuoles and lipid incorporation were measured. With the increase of cell volumes, volumes of organoides increased too, but the relative volume of nucleus decreased, and the relative volumes of vacuoles and of lipid incorporation increased.

Biometry↗

Neurologic manifestations of the organoid nevus syndrome.

Prominent neurologic abnormalities were observed in six patients with epidermal or linear sebaceous nevi (organoid nevi). These cases were remarkable for unilateral facial nevi, cognitive impairment, seizures, and focal or lateralized epileptic EEG abnormalities. Additional manifestations included the onset of seizures in the neonatal period, unilateral hypsarrhythmia or Lennox-Gastaut EEG pattern, hemiparesis, asymmetric macrocephaly, and somatic growth disturbances. The full expression of this disorder was not apparent at birth, but emerged gradually during infancy. The neurologic abnormalities in these patients were attributed to unilateral or asymmetric malformations of the CNS as demonstrated by computed tomography. A lateralized disorder of neuroectodermal proliferation, differentiation, and migration could account for both the cutaneous and neurologic abnormalities in this disorder. The striking clinical similarities in these patients suggest a close link between epidermal and linear sebaceous nevi.

Abnormalities, Multiple↗

Organoid structure of normal rat bladder in unilaminar and bilaminar histophysiologic gradient culture : methods and observations.

In lining epithelium of mammals certain recurrent architectural patterns are recognized that may be critical for epithelial organization in culture. Among these structural imperatives are three dimensional growth, restricted migration of cells, histophysiologic gradients, and continuity of epithelial membranes. Histophysiologic gradient culture procedures have been developed to comply with requirements suggested by normal tissue architecture. In a small chamber, 5 mm diam, epithelium grows attached to a thin permeable transparent collagen membrane or sandwiched between two apposed collagen membranes. The chamber is held in a plastic capsule so that metabolic exchange is limited to substances that diffuse across the collagen membranes to the adherent basal layer of epithelium. On a single membrane after 2 wk of growth, normal urothelium appears as a diffusely hypercellular urothelium, 6 to 10 cells thick. As the culture period is extended by 2 or more wk, multiple nodules of urothelium extend from the basal surface into the subepithelial space between the epithelium and the collagen membrane. Normal bladder, cultured between two apposed collagen membranes, gives rise in a few days to confluent epithelium that contains many extracellular cysts. Through an apparent merging of cysts, after 2 wk the urothelium appears as a highly organoid structure, a flattened cyst lined by completely stratified polarized urothelium. Such microbladders consist of a stratified epithelium without interruption of continuity. With histophysiologic gradient culture, processes in carcinoma and precursor lesions are accessible to study at the level of tissue organization.

Animals↗

Intracellular collagen-like material in mouse embryonic mesenchymal cells incubated with TNF-alpha and IL-1 beta in organoid culture.

Blastemal cells of embryonic mouse limb buds (day 12) were cultivated in organoid cultures in the presence of the human recombinant cytokines interleukin-1 beta (IL-1 beta) and tumour necrosis factor alpha (TNF-alpha). The effects of both cytokines (applied alone or together) on mesenchymal cells were demonstrated by electron microscopy. Cultures treated with TNF-alpha (alone or in combination with IL-1 beta) showed several mesenchymal cells with numerous irregularly shaped membrane-bordered cavities containing thick bundled tannic-acid-positive fibrillar structures that resembled loosened collagen fibrils, whereas cells exposed to IL-1 beta alone did not exhibit such changes. These findings are discussed in the light of two hypotheses: the phagocytosis of extracellular collagen fibrils, and fibrillogenesis resulting from incongruity of synthesis and secretion rates of procollagen; our results favour the former.

Animals↗

Sacrococcygeal teratoma showing organoid differentiation: report of a case.

We present the case of a neonate with a sacrococcygeal teratoma showing organoid differentiation. A 5-day-old baby girl was transferred to our hospital with a large sacrococcygeal mass. Ultrasonography revealed a few well-limited fluid-filled lesions, indicating that the teratoma had cystic components. During surgery, a sac containing 30cm of small bowel loops was found in the tumor. The bowel segment was supplied by a mesentery-like structure originating from teratoid tissue. Histopathological examination verified a benign mature teratoma with fully developed small bowel loops. The tumor was defined as a sacrococcygeal fetiform teratoma. The terminological, structural, and clinical aspects of this unusual tumor are discussed, with a review of the English literature.

Female↗

Bone formation by rat calvarial cells grown at high density in organoid culture.

Calvarial cells from day 21 rat fetuses were isolated by enzymatic digestion and grown at high density in an organoid culture system at the medium/air interface. In this type of culture, mineralization occurred as early as 7 days in vitro, as revealed by light and electron microscopic means. After about 18 days in vitro, most of the culture consisted of mineralized tissue. Mineralization was also achieved without beta-glycerophosphate, but it was delayed by 2 to 3 days. Maximal alkaline phosphatase activity occurred at days 8 to 12 in vitro and then declined continuously during further cultivation. Two types of mineralization could be observed: (1) mineralization of a collagen-rich osteoid by typical apatite crystals; (2) mineralization of a nearly collagen-free matrix by amorphous material which was possibly secreted by the cells. The importance of higher cell densities for cell differentiation and formation of histotypic tissue in vitro is apparent, and it is indicated that cell-cell contacts and cell-matrix interactions may be prerequisites for the development of histotypic conditions similar to the in vivo situation.

Alkaline Phosphatase↗

Posterior scleral choristoma in the organoid nevus syndrome (linear nevus sebaceus of Jadassohn).

PURPOSE: To highlight the association of posterior osseous and/or cartilaginous ocular choristomas with epibulbar choristomas and the nevus sebaceus of Jadassohn. DESIGN: Small case series. PARTICIPANTS: Four patients with the organoid nevus syndrome. METHODS: Clinical and histopathologic studies in four patients with epibulbar lesions and nevus sebaceus of Jadassohn. MAIN OUTCOME MEASURES: Ophthalmoscopic findings of peripapillary lesions. Computed tomographic and ultrasonographic characteristic of posterior scleral lesions. Ocular histopathologic findings in one globe from one of the study subjects. RESULTS: Three patients had the triad of posterior osseous/cartilaginous ocular choristomas, anterior epibulbar choristomas, and nevus sebaceus of Jadassohn and one patient had anterior epibulbar choristomas and posterior osseous/cartilaginous ocular choristomas. Ultrasonography and computed tomography were valuable in detecting scleral ossification or epibulbar cartilage or both. The ophthalmoscopic findings were similar to those of a choroidal osteoma. CONCLUSIONS: The presence of posterior osseous/cartilaginous ocular choristomas in a patient with epilepsy or epibulbar lesions or both suggests the diagnosis of nevus sebaceus of Jadassohn. Osseous/cartilaginous ocular choristomas should be suspected in patients with nevus sebaceus of Jadassohn and peripapillary hypopigmented fundus lesions.

Cartilage↗

A pancreatic cancer organoid-macrophage co-culture using starPEG-heparin hydrogel deciphers tumor-immune cell interactions.

Macrophages are among the most abundant immune cells in the pancreatic ductal adenocarcinoma (PDAC) tumor microenvironment (TME) and play a key role in regulating the immunosuppressive niche that facilitates tumor growth. Although recent three-dimensional (3D) culture systems using patient-derived materials have advanced our understanding of tumor biology, most models lack key cellular TME components and thus fail to capture tumor-immune cell interactions. To address this gap, we developed an in-vitro 3D co-culture model incorporating PDAC patient-derived organoids (PDOs) and macrophages within a synthetic hydrogel matrix. We optimized culture conditions by tuning medium and matrix conditions to support both cell lineages. Flow cytometry and transcriptomic analyses revealed that initially undifferentiated macrophages adopt an M2-like profile upon exposure to PDAC PDOs in starPEG-heparin hydrogels, mirroring the macrophage phenotypes observed by multiplex immunohistochemistry in the matched primary PDAC tissues. Cytokine secretome profiling revealed PDO-specific differences, indicating distinct underlying macrophage polarization subtypes. Collectively, our starPEG-heparin hydrogel-based 3D co-culture enables hypothesis-driven and physiologically relevant studies of tumor-macrophage interactions and may advance immune-modulatory treatment strategies in patients with PDAC.

Journal Article↗

Organoid nevus syndrome (linear nevus sebaceus of Jadassohn): clinical and radiological study of a case.

A 3 1/2-year-old boy with this syndrome is reported. The clinical features were: linear organoid nevus, characteristically involving the midline of the face with extension to one side (right side in this case), hemimacrocephaly, mental and motor retardation, epilepsy originating from a focus in the right hemisphere, a malformed hemisphere and ventricular system on the right side on pneumoencephalographic and angiographic study and a hamartoma-like malformation protruding into the frontal horn of the right lateral ventricle.

Cerebral Angiography↗

[Organoid nevus syndrome (Schimmelpenning-Feuerstein-Mims syndrome): case report and literature].

The main symptom of the organoid nevus syndrome (Schimmelpenning-Feuerstein-Mims-Syndrom) is the nevus sebaceous, which is mostly linear and can be of variable expression. Malformations of the skeletal system and the eyes are usually associated, while malformations of the cardio-vascular system are less common. Neurological findings such as mental retardation and seizures are of clinical relevance. We describe a case and discuss this rare syndrome.

Dysplastic Nevus Syndrome↗

[Long-term observation of a case of organoid naevus phakomatosis (Schimmelpenning-Feuerstein-Mims syndrome)].

The course of an organoid naevus phakomatosis (Schimmelpenning-Feuerstein-Mims syndrome) was observed in one patient over 25 years. Although the syndrome was fully developed, it has so far remained relatively benign, without limiting the patient's ability to work. During the course of the disease various investigations were carried out (CT, brain scintigrams, chromosome analysis). These confirm that the outstanding feature consisting of fibrous bone dysplasia of the skull continues to progress into adult life. In addition, the presence of intracerebral calcification could be demonstrated. Examination of the chromosomes suggests that further similar cases should also be examined, since the aetiology and pathogenesis of this phakomatosis are still unknown.

Adult↗