Recombinant human proteoglycan 4 lowers inflammation and atherosclerosis susceptibility in female low-density lipoprotein receptor knockout mice.

Recombinant human proteoglycan 4 (rhPRG4) is a macromolecular mucin-like glycoprotein that is classically studied as a lubricant within eyes and joints. Given that endogenously produced PRG4 is present within atherosclerotic lesions and genetic PRG4 deficiency increases atherosclerosis susceptibility in mice, in the current study we investigated the anti-atherogenic potential of chronic rhPRG4 treatment. Female low-density lipoprotein receptor knockout mice were fed an atherogenic Western-type diet for 6 weeks and injected three times per week intraperitoneally with 0.5 mg rhPRG4 or PBS as control. Treatment with rhPRG4 was associated with a small decrease in plasma-free cholesterol levels, without a change in cholesteryl ester levels. A marked increase in the number of peritoneal foam cells was detected in response to the peritoneal rhPRG4 administration, which could be attributed to elevated peritoneal leukocyte MSR1 expression levels. However, rhPRG4-treated mice exhibited significantly smaller aortic root lesions of 278 ± 21 × 103 µm2 compared with 339 ± 15 × 103 µm2 in the aortic root of control mice. The overall decreased atherosclerosis susceptibility coincided with a shift in the monocyte and macrophage polarization states towards the patrolling and anti-inflammatory M2-like phenotypes, respectively. Furthermore, rhPRG4 treatment significantly reduced macrophage gene expression levels as well as plasma protein levels of the pro-inflammatory/pro-atherogenic cytokine TNF-alpha. In conclusion, we have shown that peritoneal administration and subsequent systemic exposure to rhPRG4 beneficially impacts the inflammatory state and reduces atherosclerosis susceptibility in mice. Our findings highlight that PRG4 is not only a lubricant but also acts as an anti-inflammatory agent. KEY POINTS: Endogenously produced proteoglycan 4 is found in atherosclerotic lesions and its genetic deficiency in mice is associated with enhanced atherosclerosis susceptibility. In this study we investigated the anti-atherogenic potential of chronic treatment with recombinant human PRG4 in hypercholesterolaemic female low-density lipoprotein receptor knockout mice. We show that recombinant human PRG4 stimulates macrophage foam cell formation, but also dampens the pro-inflammatory state of monocyte/macrophages, eventually leading to a significant reduction in plasma TNF-alpha levels and a lowered atherosclerosis susceptibility. Our findings highlight that peritoneal recombinant human PRG4 treatment can execute effects both locally and systemically and suggest that it will be of interest to study whether rhPRG4 treatment is also able to inhibit the progression and/or induce regression of previously established atherosclerotic lesions.

A novel method for culturing enteric neurons generates neurospheres containing functional myenteric neuronal subtypes.

BACKGROUND: The enteric nervous system (ENS) is comprised of neurons, glia, and neural progenitor cells that regulate essential gastrointestinal functions. Advances in high-efficiency enteric neuron culture would facilitate discoveries surrounding ENS regulatory processes, pathophysiology, and therapeutics. NEW METHOD: Development of a simple, robust, one-step method to culture murine enteric neurospheres in a 3D matrix that supports neural growth and differentiation. RESULTS: Myenteric plexus cells isolated from the entire length of adult murine small intestine formed ≥3000 neurospheres within 7 days. Matrigel-embedded neurospheres exhibited abundant neural stem and progenitor cells expressing Sox2, Sox10 and Msi1 by day 4. By day 5, neural progenitor cell marker Nestin appeared in the periphery of neurospheres prior to differentiation. Neurospheres produced extensive neurons and neurites, confirmed by Tubulin beta III, PGP9.5, HuD/C, and NeuN immunofluorescence, including neural subtypes Calretinin, ChAT, and nNOS following 8 days of differentiation. Individual neurons within and external to neurospheres generated depolarization induced action potentials which were inhibited in the presence of sodium channel blocker, Tetrodotoxin. Differentiated neurospheres also contained a limited number of glia and endothelial cells. COMPARISON WITH EXISTING METHODS: This novel one-step neurosphere growth and differentiation culture system, in 3D format (in the presence of GDNF, EGF, and FGF2), allows for ∼2-fold increase in neurosphere count in the derivation of enteric neurons with measurable action potentials. CONCLUSION: Our method describes a novel, robust 3D culture of electrophysiologically active enteric neurons from adult myenteric neural stem and progenitor cells.

Optimising a self-assembling peptide hydrogel as a Matrigel alternative for 3-dimensional mammary epithelial cell culture.

Three-dimensional (3D) organoid models have been instrumental in understanding molecular mechanisms responsible for many cellular processes and diseases. However, established organic biomaterial scaffolds used for 3D hydrogel cultures, such as Matrigel, are biochemically complex and display significant batch variability, limiting reproducibility in experiments. Recently, there has been significant progress in the development of synthetic hydrogels for in vitro cell culture that are reproducible, mechanically tuneable, and biocompatible. Self-assembling peptide hydrogels (SAPHs) are synthetic biomaterials that can be engineered to be compatible with 3D cell culture. Here we investigate the ability of PeptiGel® SAPHs to model the mammary epithelial cell (MEC) microenvironment in vitro. The positively charged PeptiGel®Alpha4 supported MEC viability, but did not promote formation of polarised acini. Modifying the stiffness of PeptiGel® Alpha4 stimulated changes in MEC viability and changes in protein expression associated with altered MEC function, but did not fully recapitulate the morphologies of MECs grown in Matrigel. To supply the appropriate biochemical signals for MEC organoids, we supplemented PeptiGels® with laminin. Laminin was found to require negatively charged PeptiGel® Alpha7 for functionality, but was then able to provide appropriate signals for correct MEC polarisation and expression of characteristic proteins. Thus, optimisation of SAPH composition and mechanics allows tuning to support tissue-specific organoids.

Proteoglycan 4 (PRG4) treatment improves skin wound healing in a porcine model.

Proteoglycan 4 (PRG4) is a boundary lubricant originally identified in articular cartilage and has been since shown to have immunomodulation and antifibrotic properties. Previously, we have demonstrated that recombinant human (rh)PRG4 treatment accelerates auricular cartilage injury closure through an inhibition of the fibrotic response, and promotion of tissue regeneration in mice. The purpose of the current study was to examine the effects of rhPRG4 treatment (vs. a DMSO carried control) on full-thickness skin wound healing in a preclinical porcine model. Our findings suggest that while rhPRG4 did not significantly accelerate nor impede full-thickness skin wound closure, it did improve repair quality by decreasing molecular markers of fibrosis and increasing re-vascularization. We also demonstrated that rhPRG4 treatment increased dermal adipose tissue during the healing process specifically by retaining adipocytes in the wound area but did not inhibit lipolysis. Overall, the results of the current study have demonstrated that rhPRG4 acts as antifibrotic agent and regulates dermal adipose tissue during the healing processes resulting in a tissue with a trajectory that more resembles the native skin vs. a fibrotic patch. This study provides strong rationale to examine if rhPRG4 can improve regeneration in human wounds.

Evaluating the Effects of Pulsed Electrical Stimulation on the Mechanical Behavior and Microstructure of Medulla Oblongata Tissues.

The development of remote surgery hinges on comprehending the mechanical properties of the tissue at the surgical site. Understanding the mechanical behavior of the medulla oblongata tissue is instrumental for precisely determining the remote surgery implementation site. Additionally, exploring this tissue's response under electric fields can inform the creation of electrical stimulation therapy regimens. This could potentially reduce the extent of medulla oblongata tissue damage from mechanical compression. Various types of pulsed electric fields were integrated into a custom-built indentation device for this study. Experimental findings suggested that applying pulsed electric fields amplified the shear modulus of the medulla oblongata tissue. In the electric field, the elasticity and viscosity of the tissue increased. The most significant influence was noted from the low-frequency pulsed electric field, while the burst pulsed electric field had a minimal impact. At the microstructural scale, the application of an electric field led to the concentration of myelin in areas distant from the surface layer in the medulla oblongata, and the orderly structure of proteoglycans became disordered. The alterations observed in the myelin and proteoglycans under an electric field were considered to be the fundamental causes of the changes in the mechanical behavior of the medulla oblongata tissue. Moreover, cell polarization and extracellular matrix cavitation were observed, with transmission electron microscopy results pointing to laminar separation within the myelin at the ultrastructure scale. This study thoroughly explored the impact of electric field application on the mechanical behavior and microstructure of the medulla oblongata tissue, delving into the underlying mechanisms. This investigation delved into the changes and mechanisms in the mechanical behavior and microstructure of medulla oblongata tissue under the influence of electric fields. Furthermore, this study could serve as a reference for the development of electrical stimulation regimens in the central nervous system. The acquired mechanical behavior data could provide valuable baseline information to aid in the evolution of remote surgery techniques involving the medulla oblongata tissue.

Autoantigen-Dexamethasone Conjugate-Loaded Liposomes Halt Arthritis Development in Mice.

There is no curative treatment for chronic auto-inflammatory diseases including rheumatoid arthritis, and current treatments can induce off-target side effects due to systemic immune suppression. This work has previously shown that dexamethasone-pulsed tolerogenic dendritic cells loaded with the arthritis-specific antigen human proteoglycan can suppress arthritis development in a proteoglycan-induced arthritis mouse model. To circumvent ex vivo dendritic cell culture, and enhance antigen-specific effects, drug delivery vehicles, such as liposomes, provide an interesting approach. Here, this work uses anionic 1,2-distearoyl-sn-glycero-3-phosphoglycerol liposomes with enhanced loading of human proteoglycan-dexamethasone conjugates by cationic lysine tetramer addition. Antigen-pulsed tolerogenic dendritic cells induced by liposomal dexamethasone in vitro enhanced antigen-specific regulatory T cells to a similar extent as dexamethasone-induced tolerogenic dendritic cells. In an inflammatory adoptive transfer model, mice injected with antigen-dexamethasone liposomes have significantly higher antigen-specific type 1 regulatory T cells than mice injected with antigen only. The liposomes significantly inhibit the progression of arthritis compared to controls in preventative and therapeutic proteoglycan-induced arthritis mouse models. This coincides with systemic tolerance induction and an increase in IL10 expression in the paws of mice. In conclusion, a single administration of autoantigen and dexamethasone-loaded liposomes seems to be a promising antigen-specific treatment strategy for arthritis in mice.

Salmon nasal cartilage proteoglycan stimulates hair growth.

Hair loss is a commonly encountered problem. In this study, hair growth was enhanced by daily oral ingestion of salmon nasal cartilage proteoglycan (PG) in mice. Proteoglycan stimulated vesicular endothelial growth factor production in human follicle dermal papilla cells through insulin growth factor-1 receptor signaling, suggesting the possibility of hair loss improvement by PG ingestion.

Cordycepin improves sensitivity to temozolomide in glioblastoma cells by down-regulating MYC.

PURPOSE: Glioblastoma is one of the malignant tumors with poor prognosis and no effective treatment is available at present. METHODS: To study the effect of cordycepin combined with temozolomide on glioblastoma, we explored the effect of the combination based on network pharmacology and biological verification. RESULTS: It was found that the drug combination significantly inhibited the cell growth, proliferation, migration and invasion of LN-229 cells. Drug combination inhibited epithelial-mesenchymal transition (EMT) by up-regulating the expression of E-cadherin and suppressing the expression of N-cadherin, Zeb1 and Twist1. Through network pharmacology, we further explored the molecular mechanism of drug combination against glioblastoma, and 36 drug-disease common targets were screened. The GO biological process analysis included 44 items (P < 0.01), which mainly involved the regulation of apoptosis, cell proliferation, cell migration, etc. The enrichment analysis of KEGG pathways included 28 pathways (P < 0.05), and the first four pathways were "MicroRNA in cancer, Proteoglycans in cancer, Pathways in cancer and PI3K-AKT signaling pathway". We detected the expression of important genes in the pathways and PPI network, and the results showed that the drug combination down-regulated NFKB1, MYC, MMP-9, MCL1, CTNNB1, and up-regulated PDCD4. CONCLUSION: Cordycepin combined with temozolomide may down-regulate MYC through "MicroRNA in cancer, Proteoglycans in cancer, Pathways in cancer and PI3K-AKT signaling pathway", which in turn regulate the expression of MCL1, CTNNB1, MMP9, PDCD4, thus regulating cell proliferation, migration and apoptosis in glioblastoma.

Balancing adipocyte production and lipid metabolism to treat obesity-induced diabetes with a novel proteoglycan from Ganoderma lucidum.

Obesity is often accompanied by metabolic disorder and insulin resistance, resulting in type 2 diabetes. Based on previous findings, FYGL, a natural hyperbranched proteoglycan extracted from the G. lucidum fruiting body, can decrease blood glucose and reduce body weight in diabetic mice. In this article, the underlying mechanism of FYGL in ameliorating obesity-induced diabetes was further investigated both in vivo and in vitro. FYGL upregulated expression of metabolic genes related to fatty acid biosynthesis, fatty acid ß-oxidation and thermogenesis; downregulated the expression of insulin resistance-related genes; and significantly increased the number of beige adipocytes in db/db mice. In addition, FYGL inhibited preadipocyte differentiation of 3T3-L1 cells by increasing the expression of FABP-4. FYGL not only promoted fatty acid synthesis but also more significantly promoted triglyceride degradation and metabolism by activating the AMPK signalling pathway, therefore preventing fat accumulation, balancing adipocyte production and lipid metabolism, and regulating metabolic disorders and unhealthy obesity. FYGL could be used as a promising pharmacological agent for the treatment of metabolic disorder-related obesity.

Efficient Endocytosis of the Human Lactoferrin N-Lobe Enhances Its Antiproliferative Activity against Human Cancer Cells.

Human lactoferrin (hLF) is a glycosylated globular iron-binding protein with high functional versatility that elicits anticancer, neuroprotective, and anti-inflammatory effects. Some of the diverse functions of hLF are induced after its internalization into various cells via cell surface endocytosis receptors, such as proteoglycans, which contain glycosaminoglycan (GAG) chains. We have previously demonstrated that an hLF derivative comprising the N-terminal half of hLF (referred to as the N-lobe) is internalized by intestinal enterocyte Caco-2 cells. However, the relationship between the intracellular uptake of the N-lobe and its pharmacological activity remains poorly understood. Here, we report that the N-lobe is efficiently internalized by lung cancer cells via endocytic pathways, suppressing their proliferation. Moreover, the N-lobe showed higher intracellular uptake than hLF. We found that the N-lobe was internalized into the human lung cancer cell lines PC-14 and PC-3 via clathrin- and/or caveolae-mediated endocytosis. Intracellular uptake of the N-lobe was inhibited when an equimolar concentration of chondroitin sulfate (CS)-E, a GAG subtype involved in malignant transformation and tumor metastasis, was added. The inhibitory effect of the N-lobe on PC-14 cell proliferation decreased with the addition of CS-E in a dose-dependent manner, suggesting that the CS-recognizing sequence on the N-lobe is necessary for its internalization or that the CS proteoglycan on cancer cells acts as an endocytosis receptor. These results suggest that the efficient endocytic uptake of the N-lobe is important for its antiproliferation effects on lung cancer cell lines. Thus, the N-lobe presents a promising drug candidate for cancer treatment.

The Antiviral Compound PSP Inhibits HIV-1 Entry via PKR-Dependent Activation in Monocytic Cells.

Actin depolymerization factor (ADF) cofilin-1 is a key cytoskeleton component that serves to lessen cortical actin. HIV-1 manipulates cofilin-1 regulation as a pre- and post-entry requisite. Disruption of ADF signaling is associated with denial of entry. The unfolded protein response (UPR) marker Inositol-Requiring Enzyme-1α (IRE1α) and interferon-induced protein (IFN-IP) double-stranded RNA- activated protein kinase (PKR) are reported to overlap with actin components. In our published findings, Coriolus versicolor bioactive extract polysaccharide peptide (PSP) has demonstrated anti-HIV replicative properties in THP1 monocytic cells. However, its involvement towards viral infectivity has not been elucidated before. In the present study, we examined the roles of PKR and IRE1α in cofilin-1 phosphorylation and its HIV-1 restrictive roles in THP1. HIV-1 p24 antigen was measured through infected supernatant to determine PSP's restrictive potential. Quantitative proteomics was performed to analyze cytoskeletal and UPR regulators. PKR, IRE1α, and cofilin-1 biomarkers were measured through immunoblots. Validation of key proteome markers was done through RT-qPCR. PKR/IRE1α inhibitors were used to validate viral entry and cofilin-1 phosphorylation through Western blots. Our findings show that PSP treatment before infection leads to an overall lower infectivity. Additionally, PKR and IRE1α show to be key regulators in cofilin-1 phosphorylation and viral restriction.

Hyaluronan and Proteoglycan Link Protein 1 Activates the BMP4/Smad1/5/8 Signaling Pathway to Promote Osteogenic Differentiation: an Implication in Fracture Healing.

Osteoblast regeneration, characterized by osteoblast differentiation, is the basis of fracture healing and accelerates fracture repair. It has been reported that hyaluronan and proteoglycan link protein 1 (HAPLN1) is overexpressed during osteoblast differentiation and regulates cartilage regeneration, but its function in fracture healing remains unclear. To elucidate this issue, we collected clinical blood samples of fracture healing, established a femoral fracture rat model, and induced an osteoblast differentiation cell model. We found that HAPLN1 was overexpressed in the serum of patients with fracture healing and the bone tissues of rats with fracture healing. Furthermore, the expression of HAPLN1 was increased time dependently during the osteogenic differentiation of MC3T3-E1 cells. HAPLN1 silencing prevented osteoblast differentiation and mineralization in MC3T3-E1 cells as evidenced by decreased osteoblast differentiation-related factors, suppressed alkaline phosphatase activities, and reduced alizarin red positive staining. Mechanically, the bone morphogenic protein 4 (BMP4)/Smad1/5/8 pathway, a facilitator of osteoblastic differentiation, was found to be inhibited by HAPLN1 knockdown, and inhibition of BMP4/Smad1/5/8 signaling enhanced the effects caused by HAPLN1 silencing. These findings demonstrated that HAPLN1 might promote fracture healing by facilitating osteogenic differentiation through the BMP4/Smad1/5/8 pathway, indicating that targeting HAPLN1 may be a feasible therapeutic candidate for fracture repair.

Ganoderma lucidum polysaccharide peptide alleviates hyperuricemia by regulating adenosine deaminase and urate transporters.

Hyperuricemia (HUA) affects human health and is involved in the pathogenesis of common chronic diseases. Previous studies showed that Ganoderma lucidum extract lowered HUA in animals. However, the active ingredient and pharmacological mechanism of Ganoderma lucidum extract in the improvement of HUA are unknown. The purpose of this study was to determine the anti-HUA efficacy and related mechanism of Ganoderma lucidum polysaccharide peptide (GLPP) using a potassium oxonate (PO)-induced mouse model and an adenosine-induced cell model. The experimental results showed that blood uric acid (UA) was decreased up to 40.6% by GLPP in HUA mice in a dose-dependent manner. Additionally, GLPP significantly reduced UA production by inhibiting the hepatic and blood adenosine deaminase (ADA) activity and increased UA excretion by decreasing the expression of glucose transporter 9 (GLUT9) and increasing the expression of organic anion transporter 1 (OAT1) in kidney. The adenosine-induced cell model showed that the inhibitory effect of GLPP on ADA activity may be the main reason for the alleviation of HUA by GLPP. Furthermore, PO-induced renal histopathological damage was also alleviated by GLPP in a dose-dependent manner. The experimental results in this study indicated that GLPP exerted anti-HUA effects via regulating the UA production and excretion, suggesting that GLPP could be developed into a therapeutic agent for HUA.

Osteomodulin attenuates smooth muscle cell osteogenic transition in vascular calcification.

RATIONALE: Vascular calcification is a prominent feature of late-stage diabetes, renal and cardiovascular disease (CVD), and has been linked to adverse events. Recent studies in patients reported that plasma levels of osteomodulin (OMD), a proteoglycan involved in bone mineralisation, associate with diabetes and CVD. We hypothesised that OMD could be implicated in these diseases via vascular calcification as a common underlying factor and aimed to investigate its role in this context. METHODS AND RESULTS: In patients with chronic kidney disease, plasma OMD levels correlated with markers of inflammation and bone turnover, with the protein present in calcified arterial media. Plasma OMD also associated with cardiac calcification and the protein was detected in calcified valve leaflets by immunohistochemistry. In patients with carotid atherosclerosis, circulating OMD was increased in association with plaque calcification as assessed by computed tomography. Transcriptomic and proteomic data showed that OMD was upregulated in atherosclerotic compared to control arteries, particularly in calcified plaques, where OMD expression correlated positively with markers of smooth muscle cells (SMCs), osteoblasts and glycoproteins. Immunostaining confirmed that OMD was abundantly present in calcified plaques, localised to extracellular matrix and regions rich in α-SMA+ cells. In vivo, OMD was enriched in SMCs around calcified nodules in aortic media of nephrectomised rats and in plaques from ApoE-/- mice on warfarin. In vitro experiments revealed that OMD mRNA was upregulated in SMCs stimulated with IFNγ, BMP2, TGFß1, phosphate and ß-glycerophosphate, and by administration of recombinant human OMD protein (rhOMD). Mechanistically, addition of rhOMD repressed the calcification process of SMCs treated with phosphate by maintaining their contractile phenotype along with enriched matrix organisation, thereby attenuating SMC osteoblastic transformation. Mechanistically, the role of OMD is exerted likely through its link with SMAD3 and TGFB1 signalling, and interplay with BMP2 in vascular tissues. CONCLUSION: We report a consistent association of both circulating and tissue OMD levels with cardiovascular calcification, highlighting the potential of OMD as a clinical biomarker. OMD was localised in medial and intimal α-SMA+ regions of calcified cardiovascular tissues, induced by pro-inflammatory and pro-osteogenic stimuli, while the presence of OMD in extracellular environment attenuated SMC calcification.

Suspension culture promotes serosal mesothelial development in human intestinal organoids.

Pluripotent-stem-cell-derived human intestinal organoids (HIOs) model some aspects of intestinal development and disease, but current culture methods do not fully recapitulate the diverse cell types and complex organization of the human intestine and are reliant on 3D extracellular matrix or hydrogel systems, which limit experimental control and translational potential for regenerative medicine. We describe suspension culture as a simple, low-maintenance method for culturing HIOs and for promoting in vitro differentiation of an organized serosal mesothelial layer that is similar to primary human intestinal serosal mesothelium based on single-cell RNA sequencing and histological analysis. Functionally, HIO serosal mesothelium has the capacity to differentiate into smooth-muscle-like cells and exhibits fibrinolytic activity. An inhibitor screen identifies Hedgehog and WNT signaling as regulators of human serosal mesothelial differentiation. Collectively, suspension HIOs represent a three-dimensional model to study the human serosal mesothelium.

Bisphenol S Impairs Invasion and Proliferation of Extravillous Trophoblasts Cells by Interfering with Epidermal Growth Factor Receptor Signaling.

The placenta supports fetal growth and is vulnerable to exogenous chemical exposures. We have previously demonstrated that exposure to the emerging chemical bisphenol S (BPS) can alter placental endocrine function. Mechanistically, we have demonstrated that BPS interferes with epidermal growth factor receptor (EGFR) signaling, reducing placenta cell fusion. Extravillous trophoblasts (EVTs), a placenta cell type that aids with vascular remodeling, require EGF to invade into the maternal endometrium. We hypothesized that BPS would impair EGF-mediated invasion and proliferation in EVTs. Using human EVTs (HTR-8/SVneo cells), we tested whether BPS could inhibit the EGF response by blocking EGFR activation. We also evaluated functional endpoints of EGFR signaling, including EGF endocytosis, cell invasion and proliferation, and endovascular differentiation. We demonstrated that BPS blocked EGF-induced phosphorylation of EGFR by acting as a competitive antagonist to EGFR. Transwell assay and a three-dimensional microfluidic chip invasion assay revealed that BPS exposure can block EGF-mediated cell invasion. BPS also blocked EGF-mediated proliferation and endovascular differentiation. In conclusion, BPS can prevent EGF-mediated EVT proliferation and invasion through EGFR antagonism. Given the role of EGFR in trophoblast proliferation and differentiation during placental development, our findings suggest that maternal exposure to BPS may contribute to placental dysfunction via EGFR-mediated mechanisms.

High-throughput formation and image-based analysis of basal-in mammary organoids in 384-well plates.

This manuscript describes a new method for forming basal-in MCF10A organoids using commercial 384-well ultra-low attachment (ULA) microplates and the development of associated live-cell imaging and automated analysis protocols. The use of a commercial 384-well ULA platform makes this method more broadly accessible than previously reported hanging drop systems and enables in-incubator automated imaging. Therefore, time points can be captured on a more frequent basis to improve tracking of early organoid formation and growth. However, one major challenge of live-cell imaging in multi-well plates is the rapid accumulation of large numbers of images. In this paper, an automated MATLAB script to handle the increased image load is developed. This analysis protocol utilizes morphological image processing to identify cellular structures within each image and quantify their circularity and size. Using this script, time-lapse images of aggregating and non-aggregating culture conditions are analyzed to profile early changes in size and circularity. Moreover, this high-throughput platform is applied to widely screen concentration combinations of Matrigel and epidermal growth factor (EGF) or heparin-binding EGF-like growth factor (HB-EGF) for their impact on organoid formation. These results can serve as a practical resource, guiding future research with basal-in MCF10A organoids.

Towards organoid culture without Matrigel.

Organoids-cellular aggregates derived from stem or progenitor cells that recapitulate organ function in miniature-are of growing interest in developmental biology and medicine. Organoids have been developed for organs and tissues such as the liver, gut, brain, and pancreas; they are used as organ surrogates to study a wide range of questions in basic and developmental biology, genetic disorders, and therapies. However, many organoids reported to date have been cultured in Matrigel, which is prepared from the secretion of Engelbreth-Holm-Swarm mouse sarcoma cells; Matrigel is complex and poorly defined. This complexity makes it difficult to elucidate Matrigel-specific factors governing organoid development. In this review, we discuss promising Matrigel-free methods for the generation and maintenance of organoids that use decellularized extracellular matrix (ECM), synthetic hydrogels, or gel-forming recombinant proteins.

Generation of heart-forming organoids from human pluripotent stem cells.

Heart-forming organoids (HFOs) derived from human pluripotent stem cells (hPSCs) are a complex, highly structured in vitro model of early heart, foregut and vasculature development. The model represents a potent tool for various applications, including teratogenicity studies, gene function analysis and drug discovery. Here, we provide a detailed protocol describing how to form HFOs within 14 d. In an initial 4 d preculture period, hPSC aggregates are individually formed in a 96-well format and then Matrigel-embedded. Subsequently, the chemical WNT pathway modulators CHIR99021 and IWP2 are applied, inducing directed differentiation. This highly robust protocol can be used on many different hPSC lines and be combined with manipulation technologies such as gene targeting and drug testing. HFO formation can be assessed by numerous complementary methods, ranging from various imaging approaches to gene expression studies. Here, we highlight the flow cytometry-based analysis of individual HFOs, enabling the quantitative monitoring of lineage formation.

Compressive stress-mediated p38 activation required for ERα + phenotype in breast cancer.

Breast cancer is now globally the most frequent cancer and leading cause of women's death. Two thirds of breast cancers express the luminal estrogen receptor-positive (ERα + ) phenotype that is initially responsive to antihormonal therapies, but drug resistance emerges. A major barrier to the understanding of the ERα-pathway biology and therapeutic discoveries is the restricted repertoire of luminal ERα + breast cancer models. The ERα + phenotype is not stable in cultured cells for reasons not fully understood. We examine 400 patient-derived breast epithelial and breast cancer explant cultures (PDECs) grown in various three-dimensional matrix scaffolds, finding that ERα is primarily regulated by the matrix stiffness. Matrix stiffness upregulates the ERα signaling via stress-mediated p38 activation and H3K27me3-mediated epigenetic regulation. The finding that the matrix stiffness is a central cue to the ERα phenotype reveals a mechanobiological component in breast tissue hormonal signaling and enables the development of novel therapeutic interventions. Subject terms: ER-positive (ER + ), breast cancer, ex vivo model, preclinical model, PDEC, stiffness, p38 SAPK.