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Immunology of T Cells in AIDS: Dynamics Revealed by Eight-Color Flow Cytometry
Published in Thomas F. Kresina, Immune Modulating Agents, 2020
Mario Roederer, Stephen C. De Rosa, Leonore A. Herzenberg, Leonard A. Herzenberg
Many of the molecules expressed on the cell surface play roles in cell function: as either receptors, costimulatory molecules, or other “environmental sensors.” Changes in the expression of these molecules within a single cell may herald a change in the functionality of the cell. Furthermore, the quantitation of the expression may reveal regulatory processes effected at the transcriptional level—i.e., changes in the activation state of transcription factors, both enhancers and repressors.
Ultrastructural Immunocytochemistry
Published in Joan Gil, Models of Lung Disease, 2020
Samuel S. Spicer, Bradley A. Schulte
A second objective of immunocytochemistry is to extend our understanding of the mechanisms of normal cell function. Immunostaining for glycosyl transferase for example (Roth and Berger, 1982; Roth et al., 1985) has confirmed and extended the results of carbohydrate cytochemistry dependent on staining with lectins and basic cationic reagents (Sato and Spicer, 1982a,b) in showing the Golgi lamellae not to be homogenous but to perform different activities in cis, intermediate, and trans cisternae. Other immunocytOchemical contributions include demonstrating the intracellular distribution of cytoskeletal elements and precursor proteins (Willingham and Pasten, 1985), a glycosidase in granular reticulum (Lucocq et al., 1986), a glycosyl transferase in plasmalemma (Roth et al., 1985), and clathrin in coated pits (Willingham and Pasten, 1985).
Disorders of Growth and Differentiation
Published in Jeremy R. Jass, Understanding Pathology, 2020
Cell function is divided into three broad categories: (1) proliferation, (2) death, and (3) differentiation. Cell proliferation focuses on the cell cycle (mitogenesis) and the mechanisms that initiate and control this process. Cell death implies the programmed demise of individual cells known as apoptosis. The balance of cell generation and cell death will determine whether an organ grows, shrinks or remains the same size. Differentiation is concerned with the control of gene induction which will provide a cell with its repertoire of housekeeping requirements as well as its specialised functions. Although proliferation, death and differentiation must be studied in isolation, because each is extraordinarily complex, they are integrated not only at the level of the cell but also at the level of tissues. The global orchestration of proliferation, death and differentiation is encountered in its most dynamic and extraordinary form during embryological development. However the Hox genes, which are restricted to the animal kingdom and occur in clustered arrays for sequential activation of target genes during embryological development, also function in the stem cells of adult tissues. This is one of many examples of a single gene having multiple functions. The following account of the proliferation, death and differentiation of cells will include issues that are of particular interest to the anatomical pathologist because of their practical importance in tissue diagnosis.
Gut-derived bacterial flagellin induces beta-cell inflammation and dysfunction
Published in Gut Microbes, 2022
Torsten P.M. Scheithauer, Hilde Herrema, Hongbing Yu, Guido J. Bakker, Maaike Winkelmeijer, Galina Soukhatcheva, Derek Dai, Caixia Ma, Stefan R. Havik, Manon Balvers, Mark Davids, Abraham S. Meijnikman, Ömrüm Aydin, Bert-Jan H. van den Born, Marc G. Besselink, Olivier R. Busch, Maurits de Brauw, Arnold van de Laar, Clara Belzer, Martin Stahl, Willem M. de Vos, Bruce A. Vallance, Max Nieuwdorp, C. Bruce Verchere, Daniël H. van Raalte
Induction of hyperinsulinemia has been shown to promote obesity,4 while prevention of hyperinsulinemia by pancreas-specific genetic knockout of insulin expression prevented obesity, improved insulin sensitivity and did not result in overt hyperglycemia.4 With respect to the pancreatic islets, a chronic demand on beta cells to produce insulin is detrimental. As such, a prolonged increase in insulin secretory rates have been related to endoplasmic reticulum (ER) stress, depletion of intracellular insulin stores and beta-cell apoptosis.41 Pancreatic islets from individuals with T2D have lower insulin content compared to healthy controls.42 In mice, hyperglycemia leads to insulin content loss.43 Reversibly, strategies that induce beta-cell rest are linked to improved beta-cell function over time.44
Evaluation of cytotoxicity and biodistribution of mesoporous carbon nanotubes (pristine/-OH/-COOH) to HepG2 cells in vitro and healthy mice in vivo
Published in Nanotoxicology, 2022
Yujing Du, Zhipei Chen, M. Irfan Hussain, Ping Yan, Chunli Zhang, Yan Fan, Lei Kang, Rongfu Wang, Jianhua Zhang, Xiaona Ren, Changchun Ge
Considering that mCNTs were similar to CNTs and porous carbons, we deemed that the toxicity associated with mCNTs may have the same outcome as the aforementioned structures. Numerous reports described that CNTs can induce the intracellular reactive oxygen species (ROS) and disbalance the redox homeostasis, leading to oxidative injury (Horie and Tabei 2021; Sun, Gong, and Cao 2019). This status can impair proteins, lipids and DNA, resulting in the deterioration of cell function, metabolism, and lifespan (Alarifi et al. 2014; Girotti et al. 1985; Stone and Donaldson 2006). ROS, superoxide dismutase (SOD), and malondialdehyde (MDA) were widely applied in nanotoxicology studies as biomarkers to assess redox homeostasis (Guo et al. 2018; Moller et al. 2014). In terms of factors causing oxidative stress, surface modification is an important variable. Kumarathasan et al. (2015) reported that pristine CNTs were more cytotoxic than oxidized CNTs. Yang et al. (2018) reported that different surface modifications (modified with polyethylene glycol, bovine serum albumin, and carboxyl group) presented varying degrees of cytological effects and organ distribution. Herein, we carried out surface modification to compare the cytotoxicity and biodistribution among pristine, hydroxylated and carboxylated mCNTs.
The Responsiveness of Thymic Stromal Cells to semaphorin-3A
Published in Immunological Investigations, 2022
Marvin Paulo Lins, Návylla Candeia Medeiros, Julianderson Carmo, Felipe Lima Porto, Maria Danielma dos Santos Reis, Salete Smaniotto
To determine whether significant differences in the cellular shape observed in the Sema3A-treated thymic stromal cells originated from different cytoskeletal organizations, we analyzed the structural arrangement of F-actin filaments through immunofluorescence. Cells from the control group had a large cytoplasm area and wide lamellipodia. In addition, they had abundant dorsal and ventral stress fibers with high fluorescence intensity at the peripheral limits of the cell (Figure 3a). In the group treated with Sema3A, cells exhibited an elongated morphology, with fewer ramifications and more condensed cytoplasm. Moreover, the lamellipodia were smaller, and the stress fibers in the middle region of the cytoplasm (called transverse arches) were more abundant when compared to the control group (Figure 3b). Additionally, the longitudinal size of cells was measured and treated cells exhibited a longer length (82.21 ± 7.66 µm) than control cells (57.29 ± 3.01 µm), reflecting 30% of increase. These results showed that Sema3A can modulate the morphology of thymic stromal cells through cytoskeletal arrangement. Furthermore, the actin cytoskeleton is involved in numerous cellular activities, such as interactions with ECM elements (ligands and receptors). In addition, these elements are fundamental to thymus physiology and thymocyte differentiation (Hun et al. 2017). Therefore, these aspects of cell function were also examined.