scholarly journals Filopodyan: An Open-Source Pipeline For The Analysis Of Filopodia

2017 ◽  
Author(s):  
Vasja Urbančič ◽  
Richard Butler ◽  
Benjamin Richier ◽  
Manuel Peter ◽  
Julia Mason ◽  
...  

Filopodia have important sensory and mechanical roles in motile cells. The recruitment of actin regulators, such as ENA/VASP proteins, to sites of protrusion underlies diverse molecular mechanisms of filopodia formation and extension. We developed Filopodyan ( filopo dia dy namics an alysis) in Fiji and R to measure fluorescence in filopodia and at their tips and bases concurrently with their morphological and dynamic properties. Filopodyan supports high-throughput phenotype characterization as well as detailed interactive editing of filopodia reconstructions through an intuitive graphical user interface. Our highly customizable pipeline is widely applicable, capable of detecting filopodia in four different cell types in vitro and in vivo. We use Filopodyan to show that recruitment of ENA and VASP precedes filopodia formation in neuronal growth cones, and uncover a molecular heterogeneity whereby different filopodia display markedly different responses to changes in the accumulation of ENA and VASP in their tips over time.

2017 ◽  
Vol 216 (10) ◽  
pp. 3405-3422 ◽  
Author(s):  
Vasja Urbančič ◽  
Richard Butler ◽  
Benjamin Richier ◽  
Manuel Peter ◽  
Julia Mason ◽  
...  

Filopodia have important sensory and mechanical roles in motile cells. The recruitment of actin regulators, such as ENA/VASP proteins, to sites of protrusion underlies diverse molecular mechanisms of filopodia formation and extension. We developed Filopodyan (filopodia dynamics analysis) in Fiji and R to measure fluorescence in filopodia and at their tips and bases concurrently with their morphological and dynamic properties. Filopodyan supports high-throughput phenotype characterization as well as detailed interactive editing of filopodia reconstructions through an intuitive graphical user interface. Our highly customizable pipeline is widely applicable, capable of detecting filopodia in four different cell types in vitro and in vivo. We use Filopodyan to quantify the recruitment of ENA and VASP preceding filopodia formation in neuronal growth cones, and uncover a molecular heterogeneity whereby different filopodia display markedly different responses to changes in the accumulation of ENA and VASP fluorescence in their tips over time.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3389
Author(s):  
Ishtiaq Ahmed ◽  
Saif Ur Rehman ◽  
Shiva Shahmohamadnejad ◽  
Muhammad Anjum Zia ◽  
Muhammad Ahmad ◽  
...  

In humans, various sites like cannabinoid receptors (CBR) having a binding affinity with cannabinoids are distributed on the surface of different cell types, where endocannabinoids (ECs) and derivatives of fatty acid can bind. The binding of these substance(s) triggers the activation of specific receptors required for various physiological functions, including pain sensation, memory, and appetite. The ECs and CBR perform multiple functions via the cannabinoid receptor 1 (CB1); cannabinoid receptor 2 (CB2), having a key effect in restraining neurotransmitters and the arrangement of cytokines. The role of cannabinoids in the immune system is illustrated because of their immunosuppressive characteristics. These characteristics include inhibition of leucocyte proliferation, T cells apoptosis, and induction of macrophages along with reduced pro-inflammatory cytokines secretion. The review seeks to discuss the functional relationship between the endocannabinoid system (ECS) and anti-tumor characteristics of cannabinoids in various cancers. The therapeutic potential of cannabinoids for cancer—both in vivo and in vitro clinical trials—has also been highlighted and reported to be effective in mice models in arthritis for the inflammation reduction, neuropathic pain, positive effect in multiple sclerosis and type-1 diabetes mellitus, and found beneficial for treating in various cancers. In human models, such studies are limited; thereby, further research is indispensable in this field to get a conclusive outcome. Therefore, in autoimmune disorders, therapeutic cannabinoids can serve as promising immunosuppressive and anti-fibrotic agents.


RMD Open ◽  
2018 ◽  
Vol 4 (2) ◽  
pp. e000744 ◽  
Author(s):  
Kerstin Klein

The reading of acetylation marks on histones by bromodomain (BRD) proteins is a key event in transcriptional activation. Small molecule inhibitors targeting bromodomain and extra-terminal (BET) proteins compete for binding to acetylated histones. They have strong anti-inflammatory properties and exhibit encouraging effects in different cell types in vitro and in animal models resembling rheumatic diseases in vivo. Furthermore, recent studies that focus on BRD proteins beyond BET family members are discussed.


2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Dalia Martinez-Marin ◽  
Courtney Jarvis ◽  
Thomas Nelius ◽  
Stéphanie Filleur

Abstract Macrophages have been recognized as the main inflammatory component of the tumor microenvironment. Although often considered as beneficial for tumor growth and disease progression, tumor-associated macrophages have also been shown to be detrimental to the tumor depending on the tumor microenvironment. Therefore, understanding the molecular interactions between macrophages and tumor cells in relation to macrophages functional activities such as phagocytosis is critical for a better comprehension of their tumor-modulating action. Still, the characterization of these molecular mechanisms in vivo remains complicated due to the extraordinary complexity of the tumor microenvironment and the broad range of tumor-associated macrophage functions. Thus, there is an increasing demand for in vitro methodologies to study the role of cell–cell interactions in the tumor microenvironment. In the present study, we have developed live co-cultures of macrophages and human prostate tumor cells to assess the phagocytic activity of macrophages using a combination of Confocal and Nomarski Microscopy. Using this model, we have emphasized that this is a sensitive, measurable, and highly reproducible functional assay. We have also highlighted that this assay can be applied to multiple cancer cell types and used as a selection tool for a variety of different types of phagocytosis agonists. Finally, combining with other studies such as gain/loss of function or signaling studies remains possible. A better understanding of the interactions between tumor cells and macrophages may lead to the identification of new therapeutic targets against cancer.


Author(s):  
Vikram Sabapathy ◽  
Gabrielle Costlow ◽  
Rajkumar Venkatadri ◽  
Murat Dogan ◽  
Sanjay Kumar ◽  
...  

: The advent of organoids has renewed researcher's interest in in vitro cell culture systems. A wide variety of protocols, primarily utilizing pluripotent stem cells, are under development to improve organoid generation to mimic organ development. The complexity of organoids generated is greatly influenced based on the method used. Understanding the process of kidney organoid formation gives developmental insights into how renal cells form, mature, and interact with the adjacent cells to form specific spatiotemporal structural patterns. This knowledge can bridge the gaps in understanding in vivo renal developmental processes. Evaluating genetic and epigenetic signatures in specialized cell types can help interpret the molecular mechanisms governing cell fate. In addition, development in single-cell RNA sequencing and 3D bioprinting and microfluidic technologies has led to better identification and understanding of a variety of cell types during differentiation and designing of complex structures to mimic the conditions in vivo. While several reviews have highlighted the application of kidney organoids, there is no comprehensive review of various methodologies specifically focusing on the kidney organoids. This review summarizes the updated differentiation methodologies, applications, and challenges associated with kidney organoids. Here we have comprehensively collated all the different variables influencing the organoid generation.


BMC Cancer ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Ethan P. Metz ◽  
Erin L. Wuebben ◽  
Phillip J. Wilder ◽  
Jesse L. Cox ◽  
Kaustubh Datta ◽  
...  

Abstract Background Quiescent tumor cells pose a major clinical challenge due to their ability to resist conventional chemotherapies and to drive tumor recurrence. Understanding the molecular mechanisms that promote quiescence of tumor cells could help identify therapies to eliminate these cells. Significantly, recent studies have determined that the function of SOX2 in cancer cells is highly dose dependent. Specifically, SOX2 levels in tumor cells are optimized to promote tumor growth: knocking down or elevating SOX2 inhibits proliferation. Furthermore, recent studies have shown that quiescent tumor cells express higher levels of SOX2 compared to adjacent proliferating cells. Currently, the mechanisms through which elevated levels of SOX2 restrict tumor cell proliferation have not been characterized. Methods To understand how elevated levels of SOX2 restrict the proliferation of tumor cells, we engineered diverse types of tumor cells for inducible overexpression of SOX2. Using these cells, we examined the effects of elevating SOX2 on their proliferation, both in vitro and in vivo. In addition, we examined how elevating SOX2 influences their expression of cyclins, cyclin-dependent kinases (CDKs), and p27Kip1. Results Elevating SOX2 in diverse tumor cell types led to growth inhibition in vitro. Significantly, elevating SOX2 in vivo in pancreatic ductal adenocarcinoma, medulloblastoma, and prostate cancer cells induced a reversible state of tumor growth arrest. In all three tumor types, elevation of SOX2 in vivo quickly halted tumor growth. Remarkably, tumor growth resumed rapidly when SOX2 returned to endogenous levels. We also determined that elevation of SOX2 in six tumor cell lines decreased the levels of cyclins and CDKs that control each phase of the cell cycle, while upregulating p27Kip1. Conclusions Our findings indicate that elevating SOX2 above endogenous levels in a diverse set of tumor cell types leads to growth inhibition both in vitro and in vivo. Moreover, our findings indicate that SOX2 can function as a master regulator by controlling the expression of a broad spectrum of cell cycle machinery. Importantly, our SOX2-inducible tumor studies provide a novel model system for investigating the molecular mechanisms by which elevated levels of SOX2 restrict cell proliferation and tumor growth.


2020 ◽  
Vol 21 (22) ◽  
pp. 8484 ◽  
Author(s):  
Kritika Sharma ◽  
Tim U. Krohne ◽  
Volker Busskamp

Retinal degenerative diseases lead to irreversible blindness. Decades of research into the cellular and molecular mechanisms of retinal diseases, using either animal models or human cell-derived 2D systems, facilitated the development of several therapeutic interventions. Recently, human stem cell-derived 3D retinal organoids have been developed. These self-organizing 3D organ systems have shown to recapitulate the in vivo human retinogenesis resulting in morphological and functionally similar retinal cell types in vitro. In less than a decade, retinal organoids have assisted in modeling several retinal diseases that were rather difficult to mimic in rodent models. Retinal organoids are also considered as a photoreceptor source for cell transplantation therapies to counteract blindness. Here, we highlight the development and field’s improvements of retinal organoids and discuss their application aspects as human disease models, pharmaceutical testbeds, and cell sources for transplantations.


2020 ◽  
Vol 40 (04) ◽  
pp. 365-372
Author(s):  
Scott H. Freeburg ◽  
Wolfram Goessling

AbstractHepatocytes and biliary epithelial cells (BECs), the two endodermal cell types of the liver, originate from progenitor cells called hepatoblasts. Based principally on in vitro data, hepatoblasts are thought to be bipotent stem cells with the potential to produce both hepatocytes and BECs. However, robust in vivo evidence for this model has only recently emerged. We examine the molecular mechanisms that stimulate hepatoblast differentiation into hepatocytes or BECs. In the absence of extrinsic cues, the default fate of hepatoblasts is hepatocyte differentiation. Inductive cues from the hepatic portal vein, however, initiate transcription factor expression in hepatoblasts, driving biliary specification. Defining the mechanisms of hepatobiliary differentiation provides important insights into congenital disorders, such as Alagille syndrome, and may help to better characterize the poorly understood hepatic lineage relationships observed during regeneration from liver injury.


2000 ◽  
Vol 276 (15) ◽  
pp. 11552-11558 ◽  
Author(s):  
Janet Fawcett ◽  
Frederick G. Hamel ◽  
Robert G. Bennett ◽  
Zoltan Vajo ◽  
William C. Duckworth

In adult animals, the major effect of insulin on protein turnover is inhibition of protein degradation. Cellular protein degradation is under the control of multiple systems, including lysosomes, proteasomes, calpains, and giant protease. Insulin has been shown to alter proteasome activityin vitroandin vivo. We examined the inhibition of protein degradation by insulin and insulin analogues (LysB28,ProB29-insulin (LysPro), AspB10-insulin (B10), and GluB4,GlnB16,PheB17-insulin (EQF)) in H4, HepG2, and L6 cells. These effects were compared with receptor binding. Protein degradation was examined by release of trichloroacetic acid-soluble radioactivity from cells previously labeled with [3H]leucine. Short- and intermediate-lived proteins were examined. H4 cells bound insulin with an EC50of 4.6 × 10−9m. LysPro was similar. The affinity of B10 was increased 2-fold; that of EQF decreased 15-fold. Protein degradation inhibition in H4 cells was highly sensitive to insulin (EC50= 4.2 × 10−11and 1.6 × 10−10m, short- and intermediate-lived protein degradation, respectively) and analogues. Despite similar binding, LysPro was 11- to 18-fold more potent than insulin at inhibiting protein degradation. Conversely, although EQF showed lower binding to H4 cells than insulin, its action was similar. The relative binding potencies of analogues in HepG2 cells were similar to those in H4 cells. Examination of protein degradation showed insulin, LysPro, and B10 were equivalent while EQF was less potent. L6 cells showed no difference in the binding of the analogues compared with insulin, but their effect on protein degradation was similar to that seen in HepG2 cells except B10 inhibited intermediate-lived protein degradation better than insulin. These studies illustrate the complexities of cellular protein degradation and the effects of insulin. The effect of insulin and analogues on protein degradation vary significantly in different cell types and with different experimental conditions. The differences seen in the action of the analogues cannot be attributed to binding differences. Post-receptor mechanisms, including intracellular processing and degradation, must be considered.


2015 ◽  
Vol 224 (3) ◽  
pp. R139-R159 ◽  
Author(s):  
Patricia Joseph-Bravo ◽  
Lorraine Jaimes-Hoy ◽  
Jean-Louis Charli

Energy homeostasis relies on a concerted response of the nervous and endocrine systems to signals evoked by intake, storage, and expenditure of fuels. Glucocorticoids (GCs) and thyroid hormones are involved in meeting immediate energy demands, thus placing the hypothalamo–pituitary–thyroid (HPT) and hypothalamo–pituitary–adrenal axes at a central interface. This review describes the mode of regulation of hypophysiotropic TRHergic neurons and the evidence supporting the concept that they act as metabolic integrators. Emphasis has been be placed on i) the effects of GCs on the modulation of transcription ofTrhin vivoandin vitro, ii) the physiological and molecular mechanisms by which acute or chronic situations of stress and energy demands affect the activity of TRHergic neurons and the HPT axis, and iii) the less explored role of non-hypophysiotropic hypothalamic TRH neurons. The partial evidence gathered so far is indicative of a contrasting involvement of distinct TRH cell types, manifested through variability in cellular phenotype and physiology, including rapid responses to energy demands for thermogenesis or physical activity and nutritional status that may be modified according to stress history.


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