V. Confluence of membrane trafficking and motility in epithelial cell models

2002 ◽  
Vol 283 (5) ◽  
pp. G1015-G1019 ◽  
Author(s):  
James E. Casanova

Migration of epithelial cells occurs in a variety of important biological processes including tissue morphogenesis, wound healing, and the metastasis of epithelial tumors. In some instances, the cells remain attached to each other and migrate together as a sheet, maintaining epithelial integrity. In others (e.g., metastasis), junctional complexes are disrupted and cells migrate individually. In both cases, motility involves the extension of membranous protrusions (filopodia and lamellipodia) in the direction of movement and the transient assembly and disassembly of integrin-mediated adhesions with the extracellular matrix. The driving force for these events is provided by regulated changes in the organization of the actin cytoskeleton, which are thought to be coordinated with alterations in intracellular membrane traffic. In this themes article, I review current hypotheses about how these processes are integrated and attempt to identify fruitful areas for future research.

Cells ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1478 ◽  
Author(s):  
Monilola A. Olayioye ◽  
Bettina Noll ◽  
Angelika Hausser

As membrane-associated master regulators of cytoskeletal remodeling, Rho GTPases coordinate a wide range of biological processes such as cell adhesion, motility, and polarity. In the last years, Rho GTPases have also been recognized to control intracellular membrane sorting and trafficking steps directly; however, how Rho GTPase signaling is regulated at endomembranes is still poorly understood. In this review, we will specifically address the local Rho GTPase pools coordinating intracellular membrane trafficking with a focus on the endo- and exocytic pathways. We will further highlight the spatiotemporal molecular regulation of Rho signaling at endomembrane sites through Rho regulatory proteins, the GEFs and GAPs. Finally, we will discuss the contribution of dysregulated Rho signaling emanating from endomembranes to the development and progression of cancer.


Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 777 ◽  
Author(s):  
Hianara A Bustamante ◽  
Karina Cereceda ◽  
Alexis E González ◽  
Guillermo E Valenzuela ◽  
Yorka Cheuquemilla ◽  
...  

Ubiquitination regulates several biological processes, however the role of specific members of the ubiquitinome on intracellular membrane trafficking is not yet fully understood. Here, we search for ubiquitin-related genes implicated in protein membrane trafficking performing a High-Content siRNA Screening including 1187 genes of the human “ubiquitinome” using amyloid precursor protein (APP) as a reporter. We identified the deubiquitinating enzyme PSMD14, a subunit of the 19S regulatory particle of the proteasome, specific for K63-Ub chains in cells, as a novel regulator of Golgi-to-endoplasmic reticulum (ER) retrograde transport. Silencing or pharmacological inhibition of PSMD14 with Capzimin (CZM) caused a robust increase in APP levels at the Golgi apparatus and the swelling of this organelle. We showed that this phenotype is the result of rapid inhibition of Golgi-to-ER retrograde transport, a pathway implicated in the early steps of the autophagosomal formation. Indeed, we observed that inhibition of PSMD14 with CZM acts as a potent blocker of macroautophagy by a mechanism related to the retention of Atg9A and Rab1A at the Golgi apparatus. As pharmacological inhibition of the proteolytic core of the 20S proteasome did not recapitulate these effects, we concluded that PSMD14, and the K63-Ub chains, act as a crucial regulatory factor for macroautophagy by controlling Golgi-to-ER retrograde transport.


2017 ◽  
Vol 23 (3) ◽  
pp. 454-466 ◽  
Author(s):  
Daniele R. Nogueira-Librelotto ◽  
Cristiane F. Codevilla ◽  
Ammad Farooqi ◽  
Clarice M. B. Rolim

A lot of effort has been devoted to achieving active targeting for cancer therapy in order to reach the right cells. Hence, increasingly it is being realized that active-targeted nanocarriers notably reduce off-target effects, mainly because of targeted localization in tumors and active cellular uptake. In this context, by taking advantage of the overexpression of transferrin receptors on the surface of tumor cells, transferrin-conjugated nanodevices have been designed, in hope that the biomarker grafting would help to maximize the therapeutic benefit and to minimize the side effects. Notably, active targeting nanoparticles have shown improved therapeutic performances in different tumor models as compared to their passive targeting counterparts. In this review, current development of nano-based devices conjugated with transferrin for active tumor-targeting drug delivery are highlighted and discussed. The main objective of this review is to provide a summary of the vast types of nanomaterials that have been used to deliver different chemotherapeutics into tumor cells, and to ultimately evaluate the progression on the strategies for cancer therapy in view of the future research.


2013 ◽  
Vol 200 (4) ◽  
pp. 407-418 ◽  
Author(s):  
Mini Jose ◽  
Sylvain Tollis ◽  
Deepak Nair ◽  
Jean-Baptiste Sibarita ◽  
Derek McCusker

Formation of a stable polarity axis underlies numerous biological processes. Here, using high-resolution imaging and complementary mathematical modeling we find that cell polarity can be established via the spatial coordination of opposing membrane trafficking activities: endocytosis and exocytosis. During polarity establishment in budding yeast, these antagonistic processes become apposed. Endocytic vesicles corral a central exocytic zone, tightening it to a vertex that establishes the polarity axis for the ensuing cell cycle. Concomitantly, the endocytic system reaches an equilibrium where internalization events occur at a constant frequency. Endocytic mutants that failed to initiate periodic internalization events within the corral displayed wide, unstable polarity axes. These results, predicted by in silico modeling and verified by high resolution in vivo studies, identify a requirement for endocytic corralling during robust polarity establishment.


2021 ◽  
Vol 07 ◽  
Author(s):  
Wei Li

: Exploring low-cost, green and safe technologies to provide an alternative to the conventional selective catalytic reduction process is key to the control of NOx emitted from small-scale boilers and other industrial processes. To meet the demand, the chemical absorption-biological reduction integrated system has been developing recently. chemical absorption-biological reduction integrated system applies Fe(II)EDTA for NO absorption and iron-reducing and denitrifying bacteria for absorbent regeneration. Many studies have focused on the enhancements of mass transfer and biological reaction, among which the biological processes were the rate-limiting steps. This review summarizes the current researches on the biological processes in the CABR system, which focuses on the mechanism and enhancement of biochemical reactions, and provides the possible directions of future research.


2021 ◽  
pp. 135245852110657
Author(s):  
Zoé LE van Kempen ◽  
Alyssa A Toorop ◽  
Finn Sellebjerg ◽  
Gavin Giovannoni ◽  
Joep Killestein

Over the past two decades, treatment options for patients with multiple sclerosis (MS) have increased exponentially. In the current therapeutic landscape, “no evidence of MS disease activity” is within reach in many of our patients. Minimizing risks of complications, improving treatment convenience, and decreasing health care costs are goals that are yet to be reached. One way to optimize MS therapy is to implement personalized or extended interval dosing. Monoclonal antibodies are suitable candidates for personalized dosing (by therapeutic drug monitoring) or extended interval dosing. An increasing number of studies are performed and underway reporting on altered dosing intervals of anti-α4β1-integrin treatment (natalizumab) and anti-CD20 treatment (ocrelizumab, rituximab, and ofatumumab) in MS. In this review, current available evidence regarding personalized and extended interval dosing of monoclonal antibodies in MS is discussed with recommendations for future research and clinical practice.


Membranes ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 702
Author(s):  
Seyyed-Mojtaba Mousavi ◽  
Zohre Mousavi Nejad ◽  
Seyyed Alireza Hashemi ◽  
Marjan Salari ◽  
Ahmad Gholami ◽  
...  

Despite the advances that have been achieved in developing wound dressings to date, wound healing still remains a challenge in the healthcare system. None of the wound dressings currently used clinically can mimic all the properties of normal and healthy skin. Electrospinning has gained remarkable attention in wound healing applications because of its excellent ability to form nanostructures similar to natural extracellular matrix (ECM). Electrospun dressing accelerates the wound healing process by transferring drugs or active agents to the wound site sooner. This review provides a concise overview of the recent developments in bioactive electrospun dressings, which are effective in treating acute and chronic wounds and can successfully heal the wound. We also discuss bioactive agents used to incorporate electrospun wound dressings to improve their therapeutic potential in wound healing. In addition, here we present commercial dressings loaded with bioactive agents with a comparison between their features and capabilities. Furthermore, we discuss challenges and promises and offer suggestions for future research on bioactive agent-loaded nanofiber membranes to guide future researchers in designing more effective dressing for wound healing and skin regeneration.


Reproduction ◽  
2021 ◽  
Vol 161 (1) ◽  
pp. F1-F17
Author(s):  
Rocío Martínez-Aguilar ◽  
Lucy E Kershaw ◽  
Jane J Reavey ◽  
Hilary O D Critchley ◽  
Jacqueline A Maybin

The endometrium is a multicellular tissue that is exquisitely responsive to the ovarian hormones. The local mechanisms of endometrial regulation to ensure optimal function are less well characterised. Transient physiological hypoxia has been proposed as a critical regulator of endometrial function. Herein, we review the literature on hypoxia in the non-pregnant endometrium. We discuss the pros and cons of animal models, human laboratory studies and novel in vivo imaging for the study of endometrial hypoxia. These research tools provide mounting evidence of a transient hypoxic episode in the menstrual endometrium and suggest that endometrial hypoxia may be present at the time of implantation. This local hypoxia may modify the inflammatory environment, influence vascular remodelling and modulate endometrial proliferation to optimise endometrial function. Finally, we review current knowledge of the impact of this hypoxia on endometrial pathologies, with a focus on abnormal uterine bleeding. Throughout the manuscript areas for future research are highlighted with the aim of concentrating research efforts to maximise future benefits for women and society.


2018 ◽  
Author(s):  
Cameron Brick ◽  
William John Skylark ◽  
Alexandra Lee Jessica Freeman ◽  
Theresa Marteau

Individual decision-makers need communications that succinctly describe potential harms and benefits of different options, but policymakers or citizens evaluating a policy are rarely given a balanced and easily understood summary of the potential outcomes of their decision. We review current policy option communication across diverse domains such as taxes, health, climate change, and international trade, followed by reviews of guidance and evidence for communication effectiveness. Our conceptual synthesis identifies four characteristics of policy options that make their communication particularly difficult: heterogeneous impacts on different segments of the population, multiple outcomes, long timescales, and large uncertainties. For communicators that are trying to inform rather than persuade, these complexities reveal a core tension between issue coverage and comprehensibility. We find little empirical evidence for how to communicate policy options effectively. We identify promising current communications, analyze them based on the above synthesis, and suggest priorities for future research. Recognizing the particular challenges of balanced, effective policy option communications could lead to better guidelines and support for policy decision-making. https://www.nature.com/articles/s41599-018-0121-9


2021 ◽  
Author(s):  
Ivana Pajic-Lijakovic ◽  
Milan Milivojevic

Although collective cell migration (CCM) is a highly coordinated migratory mode, perturbations in the form of jamming state transitions and vice versa often occur even in 2D. These perturbations are involved in various biological processes, such as embryogenesis, wound healing and cancer invasion. CCM induces accumulation of cell residual stress which has a feedback impact to cell packing density. Density-mediated change of cell mobility influences the state of viscoelasticity of multicellular systems and on that base the jamming state transition. Although a good comprehension of how cells collectively migrate by following molecular rules has been generated, the impact of cellular rearrangements on cell viscoelasticity remains less understood. Thus, considering the density driven evolution of viscoelasticity caused by reduction of cell mobility could result in a powerful tool in order to address the contribution of cell jamming state transition in CCM and help to understand this important but still controversial topic. In addition, five viscoelastic states gained within three regimes: (1) convective regime, (2) conductive regime, and (3) damped-conductive regime was discussed based on the modeling consideration with special emphasis of jamming and unjamming states.


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