Tubulin heterogeneity regulates functions and dynamics of microtubules and plays a role in the development of drug resistance in cancer

2019 ◽  
Vol 476 (9) ◽  
pp. 1359-1376 ◽  
Author(s):  
Shweta Shyam Prassanawar ◽  
Dulal Panda

Abstract Microtubules, composed of αβ-tubulin heterodimers, exhibit diverse structural and functional properties in different cell types. The diversity in the microtubule structure originates from tubulin heterogeneities, namely tubulin isotypes and their post-translational modifications (PTMs). These heterogeneities confer differential stability to microtubules and provide spatial cues for the functioning of the cell. Furthermore, the altered expressions of tubulin isotypes and PTMs are prominent factors for the development of resistance against some cancer drugs. In this review, we summarize our current knowledge of the tubulin isotypes and PTMs and how, together, they control the cellular functions of the microtubules. We also describe how cancer cells use this tubulin heterogeneity to acquire resistance against clinical agents and discuss existing attempts to counter the developed resistance.

2018 ◽  
Vol 62 (6) ◽  
pp. 781-792
Author(s):  
Nuo Yu ◽  
Niels Galjart

Microtubules are cytoskeletal elements with important cellular functions, whose dynamic behaviour and properties are in part regulated by microtubule-associated proteins (MAPs). The building block of microtubules is tubulin, a heterodimer of α- and β-tubulin subunits. Longitudinal interactions between tubulin dimers facilitate a head-to-tail arrangement of dimers into protofilaments, while lateral interactions allow the formation of a hollow microtubule tube that mostly contains 13 protofilaments. Highly homologous α- and β-tubulin isotypes exist, which are encoded by multi-gene families. In vitro studies on microtubules and MAPs have largely relied on brain-derived tubulin preparations. However, these consist of an unknown mix of tubulin isotypes with undefined post-translational modifications. This has blocked studies on the functions of tubulin isotypes and the effects of tubulin mutations found in human neurological disorders. Fortunately, various methodologies to produce recombinant mammalian tubulins have become available in the last years, allowing researchers to overcome this barrier. In addition, affinity-based purification of tagged tubulins and identification of tubulin-associated proteins (TAPs) by mass spectrometry has revealed the ‘tubulome’ of mammalian cells. Future experiments with recombinant tubulins should allow a detailed description of how tubulin isotype influences basic microtubule behaviour, and how MAPs and TAPs impinge on tubulin isotypes and microtubule-based processes in different cell types.


2021 ◽  
Vol 14 ◽  
Author(s):  
Elise Liu ◽  
Léa Karpf ◽  
Delphine Bohl

Inflammation is a shared hallmark between amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). For long, studies were conducted on tissues of post-mortem patients and neuroinflammation was thought to be only bystander result of the disease with the immune system reacting to dying neurons. In the last two decades, thanks to improving technologies, the identification of causal genes and the development of new tools and models, the involvement of inflammation has emerged as a potential driver of the diseases and evolved as a new area of intense research. In this review, we present the current knowledge about neuroinflammation in ALS, ALS-FTD, and FTD patients and animal models and we discuss reasons of failures linked to therapeutic trials with immunomodulator drugs. Then we present the induced pluripotent stem cell (iPSC) technology and its interest as a new tool to have a better immunopathological comprehension of both diseases in a human context. The iPSC technology giving the unique opportunity to study cells across differentiation and maturation times, brings the hope to shed light on the different mechanisms linking neurodegeneration and activation of the immune system. Protocols available to differentiate iPSC into different immune cell types are presented. Finally, we discuss the interest in studying monocultures of iPS-derived immune cells, co-cultures with neurons and 3D cultures with different cell types, as more integrated cellular approaches. The hope is that the future work with human iPS-derived cells helps not only to identify disease-specific defects in the different cell types but also to decipher the synergistic effects between neurons and immune cells. These new cellular tools could help to find new therapeutic approaches for all patients with ALS, ALS-FTD, and FTD.


2021 ◽  
Vol 22 ◽  
Author(s):  
Armita Mahdavi Gorabi ◽  
Mohsen Ghanbari ◽  
Thozhukat Sathyapalan ◽  
Tannaz Jamialahmadi ◽  
Amirhossein Sahebkar

MicroRNAs (miRNAs) are non-coding RNAs containing around 22 nucleotides, which are expressed in vertebrates and plants. They act as posttranscriptional gene expression regulators, fine-tuning various biological processes in different cell types. There is emerging evidence on their role in different stages of atherosclerosis. In addition to regulating the inflammatory cells involved in atherosclerosis, miRNAs play fundamental roles in the pathophysiology of atherosclerosis such as endothelial cell (EC) dysfunction, the aberrant function of the vascular smooth muscle cell (VSMC) and cholesterol metabolism. Moreover, miRNAs participate in several pathogenic pathways of atherosclerotic plaque development, including their effects on immune cell signaling receptors and lipid uptake. In this study, we review our current knowledge of the regulatory role of miRNAs in various pathogenic pathways underlying atherosclerosis development and also outline potential clinical applications of miRNAs in atherosclerosis.


Author(s):  
Elena Neumann ◽  
Klaus Frommer ◽  
Ulf Müller-Ladner

Adipokines, also called adipocytokines, are highly bioactive substances mainly expressed by adipose tissue. In addition to adipocytes, different cell types resident in various tissues produce adipokines under pathophysiological conditions. Adipokines include a growing number of pluripotent molecules such as adiponectin, resistin, leptin, and visfatin. Since distinct effects of adipokines on inflammation have been described, their influence on the (innate) immune system has been investigated in rheumatology, gastroenterology, and endocrinology. This review gives an overview on the current knowledge about the influence which adipokines have on the immune system and chronic inflammation in rheumatic diseases.


1988 ◽  
Vol 106 (6) ◽  
pp. 2023-2033 ◽  
Author(s):  
S A Lewis ◽  
N J Cowan

In the accompanying paper (Gu, W., S. A. Lewis, and N. J. Cowan. 1988. J. Cell Biol. 106: 2011-2022), we report the generation of three antisera, each of which uniquely recognizes a different mammalian alpha-tubulin isotype, plus a fourth antibody that distinguishes between microtubules containing the tyrosinated and nontyrosinated form of the only known mammalian alpha-tubulin gene product that lacks an encoded carboxy-terminal tyrosine residue. These sera, together with five sera we raised that distinguish among the known mammalian beta-tubulin isotypes, have been used to study patterns of tubulin isotype-specific expression in muscle and testis, two tissues in which characteristic developmental changes are accompanied by dramatic rearrangements in microtubule structures. As in the case of cells in culture, there is no evidence to suggest that there is subcellular sorting of different tubulin isotypes among different kinds of microtubule, even in a cell type (the developing spermatid) that simultaneously contains such functionally distinct structures as the manchette and the flagellum. On the other hand, the patterns of expression of the various tubulin isotypes show marked and distinctive differences in different cell types and, in at least one case, evidence is presented for regulation at the translational or posttranslational level. The significance of these observations is discussed in terms of the existence of the mammalian alpha- and beta-tubulin multigene families.


2019 ◽  
Vol 1 (1) ◽  
pp. H67-H73
Author(s):  
Xuechong Hong ◽  
Wenduo Gu

Vascular remodeling is a complex and dynamic pathological process engaging many different cell types that reside within the vasculature. Mesenchymal stromal/stem cells (MSCs) refer to a heterogeneous cell population with the plasticity to differentiate toward multiple mesodermal lineages. Various types of MSC have been identified within the vascular wall that actively contribute to the vascular remodeling process such as atherosclerosis. With the advances of genetic mouse models, recent findings demonstrated the crucial roles of MSCs in the progression of vascular diseases. This review aims to provide an overview on the current knowledge of the characteristics and behavior of vascular resident MSCs under quiescence and remodeling conditions, which may lead to the development of novel therapeutic approaches for cardiovascular diseases.


2018 ◽  
Vol 72 ◽  
pp. 701-727
Author(s):  
Joanna E. Mikulska

The neonatal Fc receptor, (FcRn) is a transmembrane, heterodimeric glycoprotein with a structure similar to MHC class I molecules. In contrast to MHC class I antigens, FcRn does not bind to peptides (antigens) but interacts with the Fc fragment of IgG and albumin. The FcRn-IgG interaction as well as the FcRn-albumin interaction occur at acidic pH (optimally at pH 5.0-6.5) but not in physiological environment. These two ligands bind to distinct binding sites on the receptor molecule and by different mechanisms. Now, it is known that the expression of FcRn is not restricted to sites involved in the transport of maternal IgG, and this receptor is not responsible only for transfer the passive immunity from mother to the offspring. But FcRn has a much broader range of expression and function, throughout life and in many different cell types and tissues of humans and animals. This review summarizes the status of our knowledge on the expression, interaction with ligands and functions of the neonatal Fc receptor. This article shows also the possibilities of utilizing a current knowledge on FcRn for therapeutic purposes.


2020 ◽  
Vol 10 (12) ◽  
Author(s):  
Tanner J. Bakhshi ◽  
Philippe T. Georgel

AbstractDiffuse large B-cell lymphoma (DLBCL) is the most common type of lymphoma and is notorious for its heterogeneity, aggressive nature, and the frequent development of resistance and/or relapse after treatment with standard chemotherapy. To address these problems, a strong emphasis has been placed on researching the molecular origins and mechanisms of DLBCL to develop effective treatments. One of the major insights produced by such research is that DLBCL almost always stems from genetic damage that occurs during the germinal center (GC) reaction, which is required for the production of high-affinity antibodies. Indeed, there is significant overlap between the mechanisms that govern the GC reaction and those that drive the progression of DLBCL. A second important insight is that some of the most frequent genetic mutations that occur in DLBCL are those related to chromatin and epigenetics, especially those related to proteins that “write” histone post-translational modifications (PTMs). Mutation or deletion of these epigenetic writers often renders cells unable to epigenetically “switch on” critical gene sets that are required to exit the GC reaction, differentiate, repair DNA, and other essential cellular functions. Failure to activate these genes locks cells into a genotoxic state that is conducive to oncogenesis and/or relapse.


Biology ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 355
Author(s):  
Jacopo Vizioli ◽  
Tiziano Verri ◽  
Patrizia Pagliara

Allograft inflammatory factor-1 (AIF-1) is a calcium-binding scaffold/adaptor protein often associated with inflammatory diseases. Originally cloned from active macrophages in humans and rats, this gene has also been identified in other vertebrates and in several invertebrate species. Among metazoans, AIF-1 protein sequences remain relatively highly conserved. Generally, the highest expression levels of AIF-1 are observed in immunocytes, suggesting that it plays a key role in immunity. In mammals, the expression of AIF-1 has been reported in different cell types such as activated macrophages, microglial cells, and dendritic cells. Its main immunomodulatory role during the inflammatory response has been highlighted. Among invertebrates, AIF-1 is involved in innate immunity, being in many cases upregulated in response to biotic and physical challenges. AIF-1 transcripts result ubiquitously expressed in all examined tissues from invertebrates, suggesting its participation in a variety of biological processes, but its role remains largely unknown. This review aims to present current knowledge on the role and modulation of AIF-1 and to highlight its function along the evolutionary scale.


2000 ◽  
Vol 278 (2) ◽  
pp. F192-F201 ◽  
Author(s):  
Dennis Brown

Epithelial cells in the kidney have highly specialized transport mechanisms that differ among the many tubule segments, and among the different cell types that are present in some regions. The purpose of this brief review is to examine some of the major intracellular mechanisms by which the membrane proteins that participate in these differentiated cellular functions are addressed, sorted, and delivered to specific membrane domains of epithelial cells. Unraveling these processes is important not only for our understanding of normal cellular function but is also critical for the interpretation of pathophysiological dysfunction in the context of newly generated molecular and cellular information concerning hereditary and acquired transporter abnormalities. Among the topics covered are sorting signals on proteins, role of the cytoskeleton, vesicle coat proteins, the fusion machinery, and exo- and endocytosis of recycling proteins. Examples of these events in renal epithelial cells are highlighted throughout this review and are related to the physiology of the kidney.


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