scholarly journals Loss of lamin‐B1 and defective nuclear morphology are hallmarks of astrocyte senescence in vitro and in the aging human hippocampus

Aging Cell ◽  
2021 ◽  
Author(s):  
Isadora Matias ◽  
Luan Pereira Diniz ◽  
Isabella Vivarini Damico ◽  
Ana Paula Bergamo Araujo ◽  
Laís da Silva Neves ◽  
...  
Keyword(s):  
Nuclear Morphology ◽  
Lamin B1 ◽  
Human Hippocampus

scholarly journals Loss of lamin-B1 and defective nuclear morphology are hallmarks of astrocyte senescence in vitro and in the aging human hippocampus

2021 ◽  
Author(s):  
Isadora Matias ◽  
Luan Pereira Diniz ◽  
Isabella Vivarini Damico ◽  
Laís da Silva Neves ◽  
Ana Paula Bergamo Araujo ◽  
...  
Keyword(s):  
Nuclear Lamina ◽  
Granular Cell ◽  
Significant Loss ◽  
Nuclear Morphology ◽  
Post Mortem ◽  
Human Brain Tissue ◽  
Lamin B1 ◽  
Human Hippocampus ◽  
Age Related

ABSTRACTThe increase in senescent cells in tissues, including the brain, is a general feature of normal aging and age-related pathologies. Senescent cells exhibit a specific phenotype, which includes an altered nuclear morphology and transcriptomic changes. Astrocytes undergo senescence in vitro and in age-associated neurodegenerative diseases, but little is known about whether this process also occurs in physiological aging. Here, we investigated astrocyte senescence in vitro, in old mouse brains and in post-mortem human brain tissue of elderly. We identified a significant loss of lamin-B1, a major component of the nuclear lamina, as a hallmark of senescent astrocytes. We showed a severe reduction of lamin-B1 in the dentate gyrus of aged mice, including in hippocampal astrocytes, and in the granular cell layer of the hippocampus of post-mortem human tissue from non-demented elderly. Interestingly, the lamin-B1 reduction was associated with nuclear deformations, represented by an increased incidence of invaginated nuclei and loss of nuclear circularity in senescent astrocytes in vitro and in the aging human hippocampus. In conclusion, our findings show that reduction of lamin-B1 is a conserved hallmark of astrocyte aging, as well as shed light on significant defects in nuclear lamina structure, which may impact astrocyte function during human aging.

Formation of Glutamate and GABA in Epileptogenic Tissue from Human Hippocampus in Vitro

1976 ◽  
pp. 111-118 ◽  
Author(s):  
T. Turský ◽  
M. Laššánová ◽  
M. Šramka ◽  
P. Nádvorník
Keyword(s):  
Human Hippocampus

Nuclear morphology, diameter and meiotic competence of buffalo oocytes relative to follicle size

2003 ◽  
Vol 15 (4) ◽  
pp. 223 ◽  
Author(s):  
Muhammad Rizwan Yousaf ◽  
Kazim Raza Chohan
Keyword(s):  
Germinal Vesicle ◽  
Cumulus Cells ◽  
Nuclear Morphology ◽  
Vitro Fertilization ◽  
Size Dependent ◽  
Size Groups ◽  
Follicle Size ◽  
Fetal Bovine ◽  
Meiotic Competence

The nuclear morphology, diameter and in vitro meiotic competence of buffalo oocytes was compared relative to follicle size. Cumulus–oocyte complexes (COCs) were collected from 1–<2, 2–<3, 3–<4, 4–<6 and 6–<8 mm follicles from abattoir ovaries. Cumulus cells were removed using 3 mg mL−1 hyaluronidase in saline and repeated pipetting. Denuded oocytes were measured, fixed in 3% glutaraldehyde, stained with 4,6-diamidoino-2-phenylindole and evaluated for nuclear morphology, namely the stage of germinal vesicle (GV) development before in vitro maturation (IVM). The COCs from >2-mm follicles were matured in vitro in their respective size groups for 24 h in Medium 199 supplemented with 10 μg mL−1 follicle-stimulating hormone, 10 μg mL−1 luteinizing hormone, 1.5 μg mL−1 oestradiol, 75 μg mL−1 streptomycin, 100 IU mL−1 penicillin, 10 mM HEPES and 10% fetal bovine serum. Matured oocytes were fixed, stained and evaluated for GV status and meiotic development. The number of oocytes collected from follicles 1–<8 mm in diameter averaged 1.82 per ovary. Oocytes from follicles 1–<2 mm (107.7 ± 1.6 μm), 2–<3 mm (108 ± 1.1 μm) and 3–<4 mm (114.6 ± 1.3 μm) in diameter were smaller in diameter (P < 0.05) than oocytes from follicles 4–<6 mm (124.4 ± 1.3 μm) and 6–<8 mm (131.9 ± 1.4 μm) in diameter. A majority of oocytes (P < 0.05) from <4-mm follicles was at the initial stages of GV development (GV-I, II and III), whereas oocytes from 4–<6- and 6–<8-mm follicles were at the final stages of GV-IV (35.0 and 21.6% respectively) and GV-V (49.1 and 67.5% respectively). Poor IVM rates of 32.0% and 32.7% to metaphase (M)-II were observed for oocytes isolated from 2–<3- and 3–<4-mm follicles, respectively, whereas significantly (P < 0.05) more oocytes from 4–<6- and 6–<8-mm follicles reached M-II (67.1% and 79.1% respectively). In conclusion, buffalo oocytes displayed a size-dependent ability to undergo meiotic maturation and we suggest that oocytes from >4-mm follicles should be considered in buffalo in vitro fertilization systems for better results.

Electrophysiological analysis of exogenous and endogenous adenosine actions in the rat and human hippocampus in vitro

1993 ◽  
Vol 28 (3) ◽  
pp. 386-389 ◽  
Author(s):  
Helmut L. Haas ◽  
Urs Gerber ◽  
Robert W. Greene ◽  
David R. Stevens
Keyword(s):  
Endogenous Adenosine ◽  
Human Hippocampus ◽  
Electrophysiological Analysis

scholarly journals Induction of nuclear contour irregularity during T-cell activation via the T-cell receptor/CD3 complex and CD2 antigens in the presence of phorbol esters

Blood ◽  
1994 ◽  
Vol 83 (3) ◽  
pp. 703-706
Author(s):  
U Reinhold ◽  
M Herpertz ◽  
S Kukel ◽  
I Oltermann ◽  
M Uerlich ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Receptor ◽  
Lower Percentage ◽  
Nuclear Morphology ◽  
Normal Human

To determine whether specific T-cell activation pathways could produce nuclear contour irregularity in normal human lymphocytes, purified T cells were stimulated in vitro and subsequently analyzed by electron microscopy. The degree of nuclear contour irregularity was determined with the use of a computerized planimeter. Stimulation via the T-cell receptor (TCR)/CD3 complex using anti-CD3 monoclonal antibodies induced Sezary-like morphology (nuclear contour indices > 6.5) in a significant portion (9% to 28%) of T cells derived from different normal donors. T- cell activation via CD2 antigens showed induction of Sezary-like nuclear morphology in a lower percentage of cells in comparison with stimulation via the TCR/CD3 complex. In contrast, mitogenic stimulation in vitro did not induce alterations of nuclear morphology in T cells. Immunoelectron microscopy showed that nuclear contour irregularity induced in vitro did not correlate with surface-antigen expression of T- cell subpopulations. The results indicate that Sezary-like morphology is associated with cell activation in normal human T cells.

scholarly journals Senescent Breast Luminal Cells Promote Carcinogenesis through Interleukin-8-Dependent Activation of Stromal Fibroblasts

2018 ◽  
Vol 39 (2) ◽  
Author(s):  
Huda H. Al-Khalaf ◽  
Hazem Ghebeh ◽  
Rabia Inass ◽  
Abdelilah Aboussekhra
Keyword(s):  
Breast Cancer ◽  
Epithelial To Mesenchymal Transition ◽  
Normal Breast ◽  
Dependent Manner ◽  
Stromal Fibroblasts ◽  
Mesenchymal Transition ◽  
Lamin B1 ◽  
Luminal Cells

ABSTRACT Aging and stress promote senescence, which has intrinsic tumor suppressor functions and extrinsic tumor promoting properties. Therefore, it is of utmost importance to delineate the effects of senescence inducers on the various types of cells that compose the different organs. We show here that primary normal breast luminal (NBL) cells are more sensitive than their corresponding stromal fibroblasts to proliferative as well as oxidative damage-induced senescence. Like fibroblasts, senescent NBL cells secreted elevated amounts of various cytokines, including interleukin-6 (IL-6) and IL-8, and expressed high levels of p16, p21, and p53, while lamin B1 was downregulated. When senescent, luminal cells activated stromal fibroblasts in an IL-8-dependent manner, through the activation of the STAT3 pathway. These myofibroblasts promoted the epithelial-to-mesenchymal transition and the stemness processes in breast cancer cells in a paracrine manner both in vitro and in a breast cancer animal model. These results show the role of senescent breast luminal cells in promoting the inflammatory/carcinogenic microenvironment through the activation of fibroblasts in an IL-8-dependent manner.

PRONUCLEAR SYNCHRONIZATION AND NUCLEAR MORPHOLOGY OF MATURE AND IN VITRO MATURED OOCYTES IN THE RAT: AN ULTRASTRUCTURAL STUDY

2005 ◽  
Vol 41 (8) ◽  
pp. 272 ◽  
Author(s):  
M. CINCIK ◽  
B. BAYKAL ◽  
S. ZETEROGLU ◽  
G. ONALAN ◽  
S. T. CEYHAN ◽  
...  
Keyword(s):  
Ultrastructural Study ◽  
Nuclear Morphology

scholarly journals Extreme nuclear branching in healthy epidermal cells of the Xenopus tail fin

2018 ◽  
Author(s):  
Hannah E. Arbach ◽  
Marcus Harland-Dunaway ◽  
Jessica K. Chang ◽  
Andrea E. Wills
Keyword(s):  
Nuclear Lamina ◽  
Epidermal Cells ◽  
Dominant Negative ◽  
Nuclear Shape ◽  
Nuclear Morphology ◽  
Shape Variation ◽  
Tissue Elasticity ◽  
Filamentous Actin ◽  
Cell Cycles ◽  
Lamin B1

AbstractChanges in nuclear morphology contribute to regulation of complex cell properties, including differentiation and tissue elasticity. Perturbations of nuclear morphology are associated with pathologies that include, progeria, cancer, and muscular dystrophy. The mechanisms governing nuclear shape changes in healthy cells remain poorly understood, partially because there are few healthy models of nuclear shape variation. Here, we introduce nuclear branching in epidermal fin cells of Xenopus tropicalis as a model for extreme variation of nuclear morphology in a diverse population of healthy cells. We find that nuclear branching arises and elaborates during embryonic development. They contain broadly distributed marks of transcriptionally active chromatin and heterochromatin and have active cell cycles. We find that nuclear branches are disrupted by loss of filamentous actin and depend on epidermal expression of the nuclear lamina protein Lamin B1. Inhibition of nuclear branching disrupts fin morphology, suggesting that nuclear branching may be involved in fin development. This study introduces the nuclei of the fin as a powerful new model for extreme nuclear morphology in healthy cells to complement studies of nuclear shape variation in pathological contexts.List of abbreviations and symbolsLINC-Linker of Nucleoskeleton and Cytoskeleton, HGPS – Hutchinson-Gilford Progeria Syndrome, TEM – Transmission electron microscopy, PH3 – Phosphorylated Histone 3, Lat B – Latrunculin B, WT-Wild type, Cyto D-Cytochalasin D, Lmnb1 CRISPR – lmnb1 mutants generated by CRISPR/Cas9, E-Lmnb1 CRISPR – epidermal specific lmnb1 mutants generated by CRISPR/Cas9, Scrmbl-tadpoles injected with a scrambled version of the lmnb1 targeted sgRNA, Lmnb1-rod – dominant-negative Lamin B1 containing only the rod domainSummary StatementNuclei are highly branched throughout the heterogeneous population of healthy epidermal cells that comprise the Xenopus tail fin periphery, and disruption of nuclear branching mechanisms results in improper fin morphology.

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