Primary Cell Cultures Research Articles

The Ednrb–Aim2–AKT axis regulates neural crest-derived melanoblast proliferation during early development

ABSTRACT Ednrb is specifically required to develop neural crest (NC) stem cell-derived lineages. However, it is still unknown why Ednrb signaling is only needed for the early development of melanoblasts in the skin and eye. We show that Ednrb is required for the proliferation of melanoblasts during early mouse development. To understand the mechanism of melanoblast proliferation, we found that the gene absent in melanoma 2 (Aim2) is upregulated in Ednrb-deficient NC cells by RNA-sequencing analysis. Consequently, the knockdown or knockout of Aim2 partially rescued the proliferation of Ednrb-deficient melanoblasts. Conversely, the overexpression of Aim2 in melanoblasts suppressed their proliferation. We further show that Ednrb signaling could act through the microRNA miR-196b to block the suppression of melanoblast proliferation by Aim2 in primary NC cell cultures. These results reveal the Ednrb–Aim2–AKT axis in regulating melanocyte development and suggest that Ednrb signaling functions as a negative regulator of Aim2, which inhibits the proliferation of melanoblasts in early development. These findings uncover a previously unreported role for Aim2 outside the inflammasome, showing that it is a significant regulator controlling NC stem cell-derived lineage development.

Immortalized mammosphere-derived epithelial cells retain a bioactive secretome with antimicrobial, regenerative, and immunomodulatory properties.

The secretome of primary bovine mammosphere-derived epithelial cells (MDECs) has been shown to exert antimicrobial, regenerative, and immunomodulatory properties in vitro, which warrants its study as a potential biologic treatment with the potential to be translated to human medicine. Currently, the use of the MDEC secretome as a therapy is constrained by the limited life span of primary cell cultures and the decrease of secretome potency over cell passages. To address these limitations, early-passage bovine MDECs were immortalized using hTERT, a human telomerase reverse transcriptase. The primary and immortal MDECs were compared morphologically, transcriptomically, and phenotypically. The functional properties and proteomic profiles of the secretome of both cell lines were evaluated and compared. All experiments were performed with both low and high passage cell cultures. We confirmed through in vitro experiments that the secretome of immortalized MDECs, unlike that of primary cells, maintained antimicrobial and pro-migratory properties over passages, while pro-angiogenic effects of the secretome from both primary and immortalized MDECs were lost when the cells reached high passage. The secretome from primary and immortalized MDECs, at low and high passages exerted immunomodulatory effects on neutrophils in vitro. High passage immortalized MDECs retain a bioactive secretome with antimicrobial, regenerative, and immunomodulatory properties, suggesting they may serve as a consistent cell source for therapeutic use.

Geometrically modified bovine pericardium membrane promotes the expression of molecules targeted for a faster integration and vascularization process

IntroductionIn recent years, advancements in technology and the refinement of engineering techniques have facilitated the development of tissue engineering, placing particular emphasis on the use of 3D-biomaterials with several structural and chemical geometric features. In particular, increasing information on biomaterial geometric surfaces has allowed for a better understanding of tissue regenerative processes. In the present study a comparison between BioRipar®, bovine pericardium membrane, modified with micrometric roundish regular open pores (BioR-Ps) and BioRipar® without pores (BioR-NPs) has been investigated.MethodsThe expression of adhesion molecules such as: fibronectin, vimentin, focal adhesion kinase (FAK), integrin 1β, integrin α5, E-cadherin, and molecules involved in neovascularization processes such as: vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor (VEGF-R) were evaluated in an in vitro model containing primary culture of human periodontal ligament stem cells (hPDLSCs) through multiparametric analysis.ResultsThe results indicated a markedly significant expression of all the abovementioned molecules in hPDLSCs cultured withBioR-Ps compared to hPDLSCs cultured with BioR-NPs. Scanning electron microscopy analysis indicated a marked interaction between the cells and the substrate, particularly evident in the proximity of open pores in the hPDLSCs cultured on the BioR-P surface compared to hPDLSCs cultured on the BioR-NP surface. Thus, the presence of micrometric open pores on the scaffold stimulates the proliferation potential of cells apart from their adhesion ability on the patch, particularly near the poresDiscussionExpression of angiogenic molecules strengthened the performance of the modified BioR-Ps. During synthesis, 3D-biomaterial micrometric open-pores enable better bonding between cells and materials, increasing contact area and promoting cellular molecular signals in biomaterial-guided tissue engineering.

Hops bitter β-acids have antibacterial effects against sinonasal Staphylococcus aureus but also induce sinonasal cilia and mitochondrial dysfunction.

Routine prescription of antibiotics to treat chronic rhinosinusitis (CRS) exacerbations may contribute to the propagation of antibiotic resistance. Hops bitter β-acids lupulone and colupulone possess potent antibacterial activities and, as T2R1, T2R14, and/or T2R40 agonists, may improve the impaired mucociliary clearance described in CRS patients. We investigated these molecules as alternative treatments to antibiotics in CRS management based on their antibacterial and T2Rs agonists properties. Human nasal primary cells (HNECs) and RPMI2650 cells cultures were used as study models. T2Rs expression in cell culture models and human nasal tissue was assessed using immunofluorescence, quantitative PCR, and Western blot. We performed calcium imaging and cilia beat frequency experiments to investigate T2Rs activation in study models in response to lupulone and colupulone stimulations. Finally, we studied hops β-acids cytotoxicity on cells using CellEvent, crystal violet, lactate dehydrogenase assays, immunofluorescence, and transepithelial electrical resistance assays. We confirmed lupulone and colupulone potent antibacterial effect on CRS-relevant methicillin-resistant Staphylococcus aureus but found minimal impact on P. aeruginosa. We also report T2R1, T2R14 and T2R40 expression in HNECs and RPMI2650 cell cultures. Lupulone and colupulone induced an increase in cytosolic calcium that appeared dependent on T2Rs signaling. This response was accompanied by mitochondrial membrane depolarization, cellular energy stress, decreased cell proliferation, ciliostasis, and HNECs remodeling after a single exposure to lupulone at micromolar concentrations. Our data suggest that hops β-acids may not be beneficial as treatments in CRS patients and instead contribute to the disease by impairing cell health and further deteriorating the MCC.

DDDR-48. EZH2 INHIBITION AS A POTENTIAL THERAPEUTIC AVENUE IN THE TREATMENT OF MENINGIOMA

Abstract INTRODUCTION High grade meningiomas provide challenges to treatment as these neoplasms are more likely to recur, exhibit invasion of brain parenchyma, and result in decreased long term survival. Recent works demonstrate the epigenetic modifier, EZH2, to be increased in higher grade meningiomas, and to correlate with poor survival. The selective targeting of EZH2 has shown promise in other malignancies with overexpression of or gain-of-function mutations in EZH2, leading to promising findings. Here we sought to investigate the effect of EZH2 inhibition on meningioma cell growth and viability, using a panel of in vitro models. METHODS Human immortalized meningioma cell lines, mouse meningioma cell lines and a panel of human primary cell cultures with varying baseline protein expression of NF2, SMARCB1, and EZH2, were selected for investigation. Cells were treated with several selective small molecule inhibitors of EZH2. Cell proliferation, cell cycle and cell death processes were assessed. RNAseq was used to assess transcriptional changes in response to EZH2 inhibition. Western blots were used to assess protein changes in response to EZH2 inhibition. RESULTS EZH2 inhibition significantly impairs meningioma cell proliferation, at varying IC50s, in all cell lines and primary cultures tested, utilizing a panel of EZH2 inhibitors. EZH2 inhibition resulted in significantly decreased colony formation in a high-grade cell line. Furthermore, EZH2 inhibition results in a reduction of Ki67+ cells, induction of cell cycle arrest, and apoptosis. Similar grouping of differential gene expression in immortalized cell lines and primary cell cultures is observed across cell lines and primary cell cultures, after EZH2 inhibition. CONCLUSION Our work demonstrates that EZH2 inhibition results in growth inhibition, cell cycle arrest, and cell death, across all cell lines, and cell cultures tested. Futhermore, modulation of protein levels of the EZH2 target H3K27 is observed upon treatment. RNA changes are broad and involve cell proliferative and migratory processes. This work provides the framework for further investigation of EZH2 inhibition in meningioma.

EXTH-20. EXPLORING EUPHOL’S THERAPEUTIC EFFECT IN ADULT AND PEDIATRIC BRAZILIAN HIGH-GRADE GLIOMAS PRE-CLINICAL MODELS

Abstract High grade gliomas (HGG) are among the most aggressive brain tumors affecting both adults and children. Adult HGG (aHGG) account for almost 25% of all brain tumors in adults, with glioblastoma (GBM) being the predominant subtype. Pediatric HGG (pHGG), though less common, accounts for 3-15% of primary brain tumors in children and exhibits distinct genetic profiles compared to aHGG. Standard treatment for HGG in both adults and pediatric patients includes maximal surgical resection followed by temozolomide (TMZ)-based chemotherapy and radiation therapy. Our group previously reported that euphol, a natural compound derived from the sap of Euphorbiaceae family plants, exerts cytotoxicity effects on glioma cells. In this study, we investigated the therapeutic potential of euphol in primary cell cultures and xenograft models derived from six Brazilian HGG patients, including three adults and three pediatrics. In vitro, euphol exposure significantly reduced cell viability reduction, clonogenic capacity, and migration, while enhancing apoptosis in all six primary cultures. Additionally, euphol sensitized glioma cells to TMZ, resulting in a synergistic cytotoxic effect. In vivo, euphol reduced tumor growth in both GBM and pHGG models, and prolonged the survival of mice in the GBM orthotopic experiment. These findings highlight the promising therapeutic potential of euphol for treating high-grade gliomas in both adult and pediatric populations.

RBIO-10. RADIATION FRACTION SIZE DIFFERENTIALLY AFFECTS MYELOID-DERIVED SUPPRESSOR CELL (MDSC) SUBSETS IN WHO GRADE 1 MENINGIOMA

Abstract Meningiomas are often cured after focal therapy with surgical resection and/or radiotherapy (RT); however, a small proportion still recur. RT dose can be used to modulate anti-tumor immune responses, potentially through regulating immunosuppressive MDSCs. Here, we investigate the effect of a single fraction of RT (2Gy vs. 15Gy) on frequency and activation status of MDSC subsets in patients with WHO grade 1 meningioma. We hypothesize that 2Gy will promote immunosuppressive MDSC activity more than 15Gy. Fresh tumor cells from patients with a presumed diagnosis of meningioma were digested into primary cell cultures and treated with a single fraction of 2 or 15 Gy or were sham irradiated using a XRAD 320 Biological Irradiator. Cells were incubated for 18hrs prior to flow cytometric analysis. MDSC populations were identified as Live/Dead-CD11b+CD33+HLA-DR-. MDSC subsets were then divided into M-MDSC (CD14+CD15-) or G-MDSC (CD15+CD14-). Five WHO grade 1 meningiomas were analyzed. The total frequency of MDSCs in tumors increased from 3% with sham RT to 4% after irradiation with 2Gy (p=0.03). This was driven by a 2-fold increase in frequency of total M-MDSCs, as G-MDSCs decreased by half after 2Gy (p=0.03). After irradiation with 15Gy, M-MDSC frequency was nearly half that of 2Gy. The frequency of TGF-β+MDSCs increased after 15 Gy (p=0.02). The frequency of IL-10+G-MDSCs increased in response to 2Gy (p =0.03) but decreased 4-fold after 15Gy. 18hrs after 2Gy, IFN-γ+M-MDSCs increased compared to sham (p=0.01). In this small cohort of grade 1 meningiomas, a 2Gy fraction of RT appeared to support expansion of the M-MDSC subset. RT at both fraction sizes increased immunosuppressive cytokine producing-MDSCs: M-MDSC-IL-10; G-MDSC-TGF-β. These findings indicate the need for further studies to understand the subset-specific impact of RT on MDSC, a key immune cell type in brain cancers.

EXTH-78. A NOVEL BISPECIFIC S100A4/TFR ANTIBODY TO REPROGRAM THE GLIOMA TUMOR MICROENVIRONMENT AND TARGET GLIOMA STEM CELLS

Abstract GBM (glioblastoma) is the most common and aggressive primary brain tumor in adults. While immunotherapy is a promising treatment modality for GBM, most clinical trials have thus far only provided a modest benefit to GBM patients. We propose that enhancing the efficacy of immunotherapy for GBM requires approaches that increase T cell infiltration and reprogram the myeloid cells to a more pro-inflammatory state. S100A4 is a major regulator of stemness, epithelial-mesenchymal transition, and a critical regulator of immune suppressive myeloid and T cell phenotypes in GBM. Targeting S100A4 in either glioma or stromal cells is sufficient to reprogram the tumor immune landscape and extend survival of glioma bearing mice, indicating that S100A4 is a promising immunotherapy target. We recently developed a S100A4 blocking monoclonal antibody; however, this antibody does not cross the blood brain barrier (BBB) efficiently to confer significant therapeutic benefit, limiting its efficacy in treating GBM. To overcome this challenge, we generated a bispecific S100A4-TfR antibody (BsA) that allows robust BBB penetration, and tested this in a pre-clinical syngeneic, orthotopic mouse model of GBM. Using ELISA, confocal immunofluorescent microscopy, flow cytometry, and bulk RNA sequencing, we report that systemic administration of the S100A4-TfR BsA results in increased immune cell infiltration with a preferential increase in CD4 T cell infiltration, and potent immune remodeling of the tumor microenvironment to a more pro-inflammatory state. Furthermore, the BsA is taken up by glioma cells intracellularly, which is correlated with depletion of intracellular S100A4 and decreased nuclear SOX2 localization, which would reduce stemness of glioma cells. Functionally, in vitro BsA treatment of primary glioma cell cultures shows decreased S100A4 expression, proliferation, and self-renewal. Our results suggest that S100A4-TfR BsA is a novel dual activity inhibitor to simultaneously reprogram the GBM immune landscape and reduce glioma stemness.

DDEL-12. LOCAL DELIVERY OF CHEMOTHERAPIES VIA BIORESORBABLE IMPLANT IN MENINGIOMAS

Abstract Many meningiomas recur despite repeated surgical resections and radiation, and patients must undergo progressively morbid surgical procedures due to recurrent or progressive disease. However, unlike most gliomas, meningiomas do not diffusely infiltrate throughout the brain on a single-cell basis, but instead recur and invade locally. Thus, they may be particularly vulnerable to localized chemotherapy. To investigate this, we screened 13 patient-derived primary meningioma cell cultures and two commercially available meningioma cell lines using a library of 147 FDA-approved compounds. We identified drugs with elevated potency across all meningiomas, including bortezomib (mean IC50 = 7nM) and romidepsin (mean IC50 = 18nM), as well as drugs with selective potency against specific samples, such as docetaxel (IC50 range 6nM to >10uM). We reasoned that delivery of a multi-drug cocktail with independent anti-neoplastic mechanisms would provide the strongest therapeutic effect in meningiomas. As systemic treatment with combination agents resulted in severe toxicity in mice, we performed local injection of bortezomib / romidepsin / docetaxel (BRD) triple therapy over 24 days in flank xenografts of IOMM-LEE and CH157 meningiomas. Tumor growth was reduced by 71-88% relative to vehicle (p<0.01), and mice showed no systemic toxicity with local therapy. Notably, the addition of radiotherapy did not further enhance the effect of BRD. To optimize local delivery, we developed a polyanhydride bioresorbable wafer designed to fit in a meningioma resection cavity, analogous to carmustine wafers used in gliomas. Intracranial implantation of wafers caused no local toxicity or inflammation in mice. Docetaxel-loaded wafers prevented the growth of flank-injected IOMM-LEE cells relative to wafers without drug (0 mm3 vs. 230 mm3 at 3 weeks post-injection, N=5/group, p<0.01). Our results demonstrate that bioresorbable wafers containing a cocktail of potent chemotherapies may be an effective new strategy against locally aggressive meningiomas.

Therapeutic potential of targeting the FLNA-regulated Wee1 kinase in adrenocortical carcinomas.

Filamin A (FLNA) is poorly expressed in adrenocortical carcinomas (ACC) compared to adenomas (ACA). Its presence is associated to a less aggressive tumour behaviour, potentially due to its role in negatively regulating IGF1R signalling. Upregulation of G2/M Wee1 kinase was shown in FLNA-deficient mouse neural progenitor cells, and it has been reported in several tumours. This study explored Wee1 expression in ACC and its regulation by FLNA, the effects of Wee1 inhibitor AZD1775, and the impact of FLNA on its efficacy in ACC cell lines and primary cells. Analysis of FLNA and Wee1 proteins revealed elevated Wee1 and reduced FLNA in ACC compared to normal adrenal gland. FLNA knockdown increased Wee1 protein in NCI-H295R, MUC-1, and in primary ACC cells. Higher p-CDK1 and cyclin B1 were shown in FLNA-silenced MUC-1, while decreased Wee1, p-CDK1 and cyclin B1 resulted after FLNA overexpression. Wee1 reduction was reverted by lactacystin treatment and FLNA transfection increased p-Wee1 (Ser123), suggesting FLNA's role in targeting Wee1 for degradation. AZD1775 dose-dependently reduced proliferation and viability in ACC cell lines and primary cultures, and it triggered MUC-1 cell death. Similar effects were induced by Wee1 silencing. FLNA depletion augmented AZD1775's efficacy in reducing proliferation and potentiating apoptosis in MUC-1 and primary cells. In conclusion, we demonstrated that FLNA regulates Wee1 expression by promoting its degradation, suggesting that low FLNA typical of ACC leads to increased Wee1 with consequent cancer cells growth. It proposes Wee1 inhibition as a new potential therapeutic approach for ACC, particularly for those lacking FLNA.

CNSC-01. PEDIATRIC GLIOMAS EXPRESS CIRCADIAN GENES AND DEMONSTRATE CIRCADIAN REGULATION OF TEMOZOLOMIDE SENSITIVITY

Abstract INTRODUCTION Pediatric high-grade gliomas (pHGG) are highly invasive brain tumors with dismal survival rates, prompting the need for innovative therapeutic strategies. Previous research in adult glioblastoma patients revealed a correlation between the timing of Temozolomide administration and patient survival. There has, however, been limited exploration into circadian gene expression in pediatric gliomas. In this study, we investigate whether pHGGs exhibit rhythmic expression of circadian genes and whether the timing of drug administration influences Temozolomide sensitivity. METHODS A bioinformatics approach, immunocytochemistry and immunoblotting were used to assess key circadian genes in low- and high-grade gliomas. We then used timed qPCR to assess rhythmic expression in BMAL1 and REV-ERBα, two key circadian genes, across 48 hours in our pHGG cells following dexamethasone cell synchronization. Lastly, we used CyQuant Proliferation Assays to examine the effects of Temozolomide applied at peaks versus troughs in BMAL1 expression. RESULTS Using data from PedcBioPortal, we found significantly higher expression of BMAL1 in pHGGs compared to pLGGs (0.349 + 1.05 vs 0.0545 + 0.666, p < 0.001). We identified cellular localization of BMAL1 and REV-ERBα in pHGGs along with rhythmic expression of BMAL1 and REV-ERBα in our three pHGGs primary cell cultures across 48 hours (JTK_CYCLE, p < 0.005). Lastly, we demonstrated a chronotherapeutic response to Temozolomide in two of our pHGG cell lines, with significantly decreased proliferation when treatment occurred at trough versus peak BMAL1 expression (p < 0.01). CONCLUSION In this study, we found that circadian genes BMAL1 and REV-ERBα are expressed in pHGGs and expression patterns differ between pHGGs versus pLGGs. Circadian gene expression is rhythmic in pHGGs, and pHGGs can have differential Temozolomide-sensitivity based on circadian cycles. These findings suggest that circadian timing of chemotherapy may influence the efficacy of treatment, and next steps will be to explore the mechanisms underlying circadian regulation of Temozolomide sensitivity.

DDDR-49. REPURPOSING OF THE ANTI-VIRAL DRUG RIBAVIRIN AS A POTENTIAL MENINGIOMA THERAPEUTIC

Abstract INTRODUCTION High grade meningiomas provide significant challenges to treatment. Recent works have demonstrated meningiomas to express higher levels of the epigenetic regulator enhancer of zeste homolog 2 (EZH2), as well as the protein eIF4E, a key player in translation. These two molecules are demonstrated targets of the well tolerated antiviral drug, ribavirin, which has recently shown promise as an anti-neoplastic agent. Based on these findings we sought to investigate the effect of ribavirin on meningioma tumorigenesis utilizing in vitro and in vivo meningioma models. METHODS Several immortalized human meningioma cell lines, three immortalized mouse meningioma cell lines, and a panel of human primary cell cultures were assessed. Cell proliferation, cell colony formation, clonogenic assay, and cell death were assessed. Furthermore, we tested ribavirin efficacy in vivo utilizing two aggressive high grade syngeneic orthotopic allograft meningioma models in FVB WT mice. RESULTS We provide evidence that ribavirin significantly impairs meningioma cell growth and proliferation, and induces cell death in vitro. Most importantly, we demonstrate that ribavirin alone significantly improves the survival of mice orthotopically implanted with MGS2 cells. Ribavirin-treated animals exhibited a significantly increased median survival (67 days) compared to controls (41 days; p=0.0009;) in an orthotopic convexity meningioma xenograft model. Furthermore, ribavirin treatment resulted in increased survival in an orthotopic skull base meningioma xenograft model. CONCLUSION Our work establishes that ribavirin is effective against meningioma in vitro and in vivo. Ribavirin treatment reduced proliferation in all cell lines tested, in both high and low grade models, induced cell death, and prolonged survival in two aggressive in vivo models, potentially via modulation of the EZH2 and eIF4E pathways. Given the lack of medical therapy for high grade meningiomas, these findings provide a framework for further investigation into ribavirin’s effects on meningioma tumorigenesis, and demonstrate ribavirin as a potential new therapeutic option in the treatment of meningioma.

Pulmonary-delivered Anticalin Jagged-1 antagonists reduce experimental airway mucus hyperproduction and obstruction.

Mucus hypersecretion and mucus obstruction are pathogenic features in many chronic lung diseases directly linked to disease severity, exacerbation, progression, and mortality. The Jagged-1/Notch pathway is a promising therapeutic target that regulates secretory and ciliated cell trans-differentiation in the lung. However, the Notch pathway is also required in various other organs. Hence, pulmonary delivery of therapeutic agents is a promising approach to target this pathway while minimizing systemic exposure. Using Anticalin® technology, Jagged-1 Anticalin binding proteins were generated and engineered to potent and selective inhalable Jagged-1 antagonists. Their therapeutic potential to reduce airway mucus hyperproduction and obstruction was investigated ex vivo and in vivo. In primary airway cell cultures grown at air-liquid interface and stimulated with inflammatory cytokines, Jagged-1 Anticalin binding proteins reduced both mucin gene expression and mucous cell metaplasia. In vivo, prophylactic and therapeutic treatment with a pulmonary-delivered Jagged-1 Anticalin binding protein reduced mucous cell metaplasia, epithelial thickening and airway mucus hyperproduction in IL-13 and house dust mite allergen-challenged mice, respectively. Further, in a transgenic mouse model with pathophysiologic features of cystic fibrosis and COPD, pulmonary-delivered Jagged-1 Anticalin binding protein reduced hallmarks of airway mucus obstruction. In all in vivo models a reduction of mucous cells with a concomitant increase of ciliated cells was observed. Collectively, these findings support Jagged-1 antagonists' therapeutic potential for patients with muco-obstructive lung diseases, and the feasibility of targeting the Jagged-1/Notch pathway by inhalation.

Optimized primary dorsal root ganglion cell culture protocol for reliable K+ current patch-clamp recordings

DRG primary neuron cultures, derived from rodents, closely mimic properties of sensory neurons in vivo and are highly useful for studying pain and neurological disorders. These cultures are pivotal in patch clamp electrophysiology for sensory neuron properties analysis. A detailed, replicable protocol in scientific research ensures experiment accuracy and reproducibility. This paper provides comprehensive details for replicating the protocol and achieving consistent results in primary DRG cell culture as used for patch clamp recordings. We outlined a comprehensive protocol for establishing primary DRG cell culture, optimized for improved gigaseal formation in whole-cell patch-clamp recordings. Additionally, we conducted a simulation study focused on recording macroscopic K+ channels. The findings established an optimized novel protocol that works reliably for whole-cell patch clamp recordings and data analysis using primary DRG cells prepared as described in this publication. The details for the protocol in the literature are dispersed across various publications, making it challenging to find a comprehensive summary in one source. This study confirms, for the first time, the efficacy of using fewer protocol steps, which reduces stress and variability in obtaining suitable cells for patch clamp recordings compared to existing methods in the literature. Given the challenges posed by the dissociation process of primary DRG cells and the importance of comprehensive method documentation in the literature, the protocol presented provides improved and consistent applications of primary DRG cell culture in patch clamp recordings

Shortcomings, limitations and gaps in physiological roles of extracellular vesicles in obesity.

Extracellular vesicles (EVs) play a crucial role in mediating communication between cells across species and kingdoms. The intercellular communication facilitated by EVs through autocrine and paracrine signalling mechanisms is essential for cell survival, maintaining normal metabolic functions and ensuring overall bodily homeostasis and health. Extracellular vesicles are present in various bodily fluids, such as pleural effusions, plasma, breast milk, amniotic fluid, semen and saliva. Additionally, the generation and release of EVs contribute to the removal of cellular waste. Patients with obesity exhibit a higher release and amount of circulating EVs than individuals with normal weight. This increased EV release in obesity might contribute to the inflammatory state characteristic of this metabolic condition, because higher levels of pro-inflammatory molecules are found within their cargo. However, interpreting results related to EV abundance, cargo and biological actions can be complicated by several factors; these include variations in cell sources, a wide age range (from children to the elderly), a mix of females and males, medication use and health status, a range of body weights (from normal weight to morbid obesity) and differences between in vitro assays using cell lines versus primary cultures. This article addresses the shortcomings, limitations and gaps in knowledge, providing a framework for enhancing our understanding of the physiological effects of EVs on obesity.

Targeted NAD+ repletion via biomimetic nanoparticle enables simultaneous management of intimal hyperplasia and accelerated re-endothelialization: A proof-of-concept study toward next-generation of endothelium-protective, anti-restenotic therapy

Endovascular interventions often fail due to restenosis, primarily caused by smooth muscle cell (SMC) proliferation, leading to intimal hyperplasia (IH). Current strategies to prevent restenosis are far from perfect and impose significant collateral damage on the fragile endothelial cell (EC), causing profound thrombotic risks. Nicotinamide adenine dinucleotide (NAD+) is a co-enzyme and signaling substrate implicated in redox and metabolic homeostasis, with a pleiotropic role in protecting against cardiovascular diseases. However, a functional link between NAD+ repletion and the delicate duo of IH and EC regeneration has yet to be established. NAD+ repletion has been historically challenging due to its poor cellular uptake and low bioavailability. We have recently invented the first nanocarrier that enables direct intracellular delivery of NAD+ in vivo. Combining the merits of this prototypic NAD + -loaded calcium phosphate (CaP) nanoparticle (NP) and biomimetic surface functionalization, we created a biomimetic P-NAD + -NP with platelet membrane coating, which enabled an injectable modality that targets IH with excellent biocompatibility. Using human cell primary culture, we demonstrated the benefits of NP-assisted NAD+ repletion in selectively inhibiting the excessive proliferation of aortic SMC, while differentially protecting aortic EC from apoptosis. Moreover, in a rat balloon angioplasty model, a single-dose treatment with intravenously injected P-NAD + -NP immediately post angioplasty not only mitigated IH, but also accelerated the regeneration of EC (re-endothelialization) in vivo in comparison to control groups (i.e., saline, free NAD+ solution, empty CaP-NP). Collectively, our current study provides proof-of-concept evidence supporting the role of targeted NAD+ repletion nanotherapy in managing restenosis and improving reendothelialization.

Evaluation of Cross-Linked Actin Networks (CLANs) in Human Trabecular Meshwork Cells and Tissues.

Elevated intraocular pressure (IOP) is a major risk factor for the development and progression of glaucoma, the leading cause of irreversible vision loss and blindness. An overall increase in resistance to aqueous humor outflow causes sustained elevation in IOP. Glaucomatous insults in the aqueous humor outflow pathway, including the trabecular meshwork (TM), precede such chronic physiological changes in IOP. These insults include ultrastructural changes with excessive extracellular matrix deposition and actin cytoskeletal reorganization that leads to pathological stiffening of the ocular tissues. One of the most common cytoskeletal changes associated with TM tissue stiffness in glaucoma is the increased prevalence of cross-linked actin networks (CLANs) in cells of the trabecular meshwork (TM) and lamina cribrosa (LC). In glaucomatous cells, rearrangement of linear actin stress fibers leads to formation of polygonal arrays within the cytoplasm, resembling a geodesic dome-like structure, that we identified as CLANs. In addition to increased amounts of CLANs in POAG TM cells and tissues, we also discovered that glucocorticoid (GC) and TGFβ2 signaling pathways associated with the development of ocular hypertension (OHT) and glaucoma also induced CLANs in the TM. Despite a clear association, we are yet to completely understand the mechanisms involved in CLAN formation and their direct relevance to disease pathology. In this chapter, we will describe methods to identify and characterize CLANs using fluorescent microscopy in primary TM cell cultures, ex vivo perfusion cultured human anterior segments, and in situ in human donor eyes.

Association between premature vascular smooth muscle cells senescence and vascular inflammation in Takayasu’s arteritis

ObjectivesArterial wall inflammation and remodelling are the characteristic features of Takayasu’s arteritis (TAK). It has been proposed that vascular smooth muscle cells (VSMCs) are the main targeted cells of inflammatory...

Lymphoma and Leukemia Cell Vulnerabilities and Resistance Identified by Compound Library Screens.

Response to anticancer agents is often restricted to subsets of patients. Recognition of factors underlying this heterogeneity and identification of biomarkers associated with response to drugs would greatly improve the efficacy of drug treatment. Platforms that can comprehensively map cellular response to compounds in high-throughput provide a unique tool to identify associated biomarkers and provide hypotheses for mechanisms underlying variable response. Such screens can be performed on cell lines and short-term cultures of primary cells to take advantage of the respective models' strength, which include, e.g., the ability to silence genes or introduce somatic mutations to cell lines. Cohorts of patient samples represent the natural diversity of cancers, including rarer mutations and combinatorial patterns of mutations that are often absent from existing cell lines. We here summarize a simple and scalable method for the measurement of viability after drug exposure based on ATP measurements as a surrogate for viability, which we use to measure and understand drug response in cell lines and primary cells.

Targeting the Leloir Pathway with Galactose-Based Antimetabolites in Glioblastoma.

Glioblastoma (GBM) uses Glut3 and/or Glut14 and the Leloir pathway to catabolize D-Galactose (Gal). UDP-4-deoxy-4-fluorogalactose (UDP-4DFG) is a potent inhibitor of the two key enzymes, UDP-galactose-4-epimerase (GALE) and UDP-Glucose 6-dehydrogenase (UGDH), involved in Gal metabolism and in glycan synthesis. The Gal antimetabolite 4-deoxy-4-fluorogalactose (4DFG) is a good substrate for Glut3/Glut14 and acts as a potent glioma chemotherapeutic. Primary GBM cell cultures were used to examine toxicity and alterations in glycan composition via lectin binding in fixed cells and by Western blots. Toxicity/efficacy in vivo data was performed in mouse flank and intracranial models. The effect of 4DFG on D-glucose (Glc) metabolism in GBM cells was assessed by using 13C NMR-based tracer studies. 4DFG is moderately potent against GBM cells (IC50: 125-300 µM). GBM glycosylation is disrupted by 4DFG. Survival analysis in an intracranial mouse model showed that treatment with 4DFG (6 × 25 mg/kg of 4DFG, intravenously) improved outcomes by three-fold (p < 0.01). Metabolic flux analysis revealed that both glycolytic and mitochondrial metabolic fluxes of [U-13C]Glc were significantly decreased in the presence of 4DFG in GBM cells. A functional Gal-scavenging pathway in GBM allows Gal-based antimetabolites to act as chemotherapeutics. 4DFG is metabolized by GBM in vitro and in vivo, is lethal to GBM tumors, and is well tolerated in mice.