scholarly journals Stimulation of Cl− Uptake and Morphological Changes in Gill Mitochondria‐Rich Cells in Freshwater Tilapia (Oreochromis mossambicus)

2003 ◽  
Vol 76 (4) ◽  
pp. 544-552 ◽  
Author(s):  
Il‐Chi Chang ◽  
Yuan‐Yaw Wei ◽  
Fong‐In Chou ◽  
Pung‐Pung Hwang
Keyword(s):  
Morphological Changes ◽  
Oreochromis Mossambicus ◽  
Gill Mitochondria ◽  
Stimulation Of

scholarly journals Effects of innate immune receptor stimulation on extracellular α-synuclein uptake and degradation by brain resident cells

2021 ◽  
Author(s):  
Changyoun Kim ◽  
Somin Kwon ◽  
Michiyo Iba ◽  
Brian Spencer ◽  
Edward Rockenstein ◽  
...  
Keyword(s):  
Degradation Kinetics ◽  
Morphological Changes ◽  
Direct Interaction ◽  
Innate Immune ◽  
Pathological Feature ◽  
Tlr2 Expression ◽  
Immune Receptors ◽  
Age Related ◽  
Stimulation Of

AbstractSynucleinopathies are age-related neurological disorders characterized by the progressive deposition of α-synuclein (α-syn) aggregates and include Parkinson’s disease (PD) and dementia with Lewy bodies (DLB). Although cell-to-cell α-syn transmission is thought to play a key role in the spread of α-syn pathology, the detailed mechanism is still unknown. Neuroinflammation is another key pathological feature of synucleinopathies. Previous studies have identified several immune receptors that mediate neuroinflammation in synucleinopathies, such as Toll-like receptor 2 (TLR2). However, the species of α-syn aggregates varies from study to study, and how different α-syn aggregate species interact with innate immune receptors has yet to be addressed. Therefore, we investigated whether innate immune receptors can facilitate the uptake of different species of α-syn aggregates. Here, we examined whether stimulation of TLRs could modulate the cellular uptake and degradation of α-syn fibrils despite a lack of direct interaction. We observed that stimulation of TLR2 in vitro accelerated α-syn fibril uptake in neurons and glia while delaying the degradation of α-syn in neurons and astrocytes. Internalized α-syn was rapidly degraded in microglia regardless of whether TLR2 was stimulated. However, cellular α-syn uptake and degradation kinetics were not altered by TLR4 stimulation. In addition, upregulation of TLR2 expression in a synucleinopathy mouse model increased the density of Lewy-body-like inclusions and induced morphological changes in microglia. Together, these results suggest that cell type-specific modulation of TLR2 may be a multifaceted and promising therapeutic strategy for synucleinopathies; inhibition of neuronal and astroglial TLR2 decreases pathogenic α-syn transmission, but activation of microglial TLR2 enhances microglial extracellular α-syn clearance.

scholarly journals THE MORPHOLOGICAL CHANGES IN THE TISSUES OF THE RABBIT AS A RESULT OF REDUCED OXIDATION

1918 ◽  
Vol 27 (3) ◽  
pp. 399-412 ◽  
Author(s):  
H. G. Martin ◽  
A. S. Loevenhart ◽  
C. H. Bunting
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Content ◽  
Morphological Changes ◽  
Low Oxygen ◽  
High Carbon ◽  
Red Bone Marrow ◽  
Hydropic Degeneration ◽  
Thyroid Hyperplasia ◽  
High Carbon Dioxide ◽  
Stimulation Of

Exposure of rabbits to an atmosphere of low oxygen content results in a stimulation of the cardiorespiratory systems, in an extension (hyperplasia) of red bone marrow and probably of a thyroid hyperplasia, with the further production of hydropic and hyaline degeneration in the cells of the parenchymatous organs. An atmosphere of high carbon dioxide and normal oxygen content produces, however, a stimulation of the cardiorespiratory systems, but no marrow extension and, in the concentrations used, but slight hydropic degeneration in the parenchyma of the glandular organs.

The effect of exogenous RNA extract on chick embryo fibroblasts in vitro

Development ◽  
1970 ◽  
Vol 23 (2) ◽  
pp. 509-517
Author(s):  
A. Sann ◽  
D. Sharp ◽  
J. McKenzie
Keyword(s):  
Cell Differentiation ◽  
Chick Embryo ◽  
Morphological Changes ◽  
Bacterial Cells ◽  
Baby Hamster Kidney ◽  
Exogenous Rna ◽  
Embryo Fibroblasts ◽  
Stimulation Of ◽  
Rna Extract

It is extremely difficult, if not impossible, to reconcile the conflicting claims of those who have treated different cells and tissues with exogenous RNA. Some authors (e.g. Niu, Cordova & Niu, 1961; Niu, Cordova & Radbill, 1962) maintain that RNA extracts alter the course of cell differentiation to conform in morphological terms to the source of the RNA; in the same vein, Amos, Askonas & Soeiro (1964) have shown that, under certain conditions, RNA from mouse and bacterial cells can stimulate chick embryo fibroblasts to synthesize protein related antigenically to the origin of the RNA. Shepley, Ambrose & Kirby (1965), however, obtained stimulation of growth with permanent morphological changes in baby hamster kidney fibroblasts by the addition of RNA from a variety of sources.

scholarly journals Redistribution and characterization of (H+ + K+)-ATPase membranes from resting and stimulated gastric parietal cells

1985 ◽  
Vol 231 (3) ◽  
pp. 641-649 ◽  
Author(s):  
B H Hirst ◽  
J G Forte
Keyword(s):  
Atpase Activity ◽  
Morphological Changes ◽  
Parietal Cells ◽  
Apical Plasma Membrane ◽  
Octyl Glucoside ◽  
Gastric Parietal Cells ◽  
Low K ◽  
K Permeability ◽  
Stimulation Of

When isolated from resting parietal cells, the majority of the (H+ + K+)-ATPase activity was recovered in the microsomal fraction. These microsomal vesicles demonstrated a low K+ permeability, such that the addition of valinomycin resulted in marked stimulation of (H+ + K+)-ATPase activity, and proton accumulation. When isolated from stimulated parietal cells, the (H+ + K+)-ATPase was redistributed to larger, denser vesicles: stimulation-associated (s.a.) vesicles. S.a. vesicles showed an increased K+ permeability, such that maximal (H+ + K+)-ATPase and proton accumulation activities were observed in low K+ concentrations and no enhancement of activities occurred on the addition of valinomycin. The change in subcellular distribution of (H+ + K+)-ATPase correlated with morphological changes observed with stimulation of parietal cells, the microsomes and s.a. vesicles derived from the intracellular tubulovesicles and the apical plasma membrane, respectively. Total (H+ + K+)-ATPase activity recoverable from stimulated gastric mucosa was 64% of that from resting tissue. Therefore, we tested for latent activity in s.a. vesicles. Permeabilization of s.a. vesicles with octyl glucoside increased (H+ + K+)-ATPase activity by greater than 2-fold. Latent (H+ + K+)-ATPase activity was resistant to highly tryptic conditions (which inactivated all activity in gastric microsomes). About 20% of the non-latent (H+ + K+)-ATPase activity was also resistant to trypsin digestion. We interpret these results as indicating that, of the s.a. vesicles, approx. 55% have a right-side-out orientation and are impermeable to ATP, 10% right-side-out and permeable to ATP, and 35% have an inside-out orientation.

Monochloramine induces reorganization of nuclear speckles and phosphorylation of SRp30 in human colonic epithelial cells: role of protein kinase C

2003 ◽  
Vol 285 (5) ◽  
pp. C1294-C1303 ◽  
Author(s):  
Ya-Qin Zhu ◽  
Yu Lu ◽  
Xiao-Di Tan
Keyword(s):  
Gastrointestinal Tract ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Morphological Changes ◽  
Sr Proteins ◽  
Mrna Splicing ◽  
Intestinal Epithelial ◽  
Nuclear Speckles ◽  
Colonic Epithelial Cells ◽  
Stimulation Of

Intestinal epithelial cells are constantly stimulated by reactive oxidant metabolites (ROMs) in inflamed mucosa. Monochloramine (NH2Cl), a cell-permeant ROM, is particularly relevant to the pathogenesis of inflammation in the gastrointestinal tract. Nuclear speckles, a unique nuclear subcompartment, accumulate a family of proteins, namely, serine- and arginine-rich (SR) proteins. They play important roles in regulation of pre-mRNA splicing. Currently, little is known about the link between inflammatory stimulation and the pre-mRNA splicing process, although gene expression is changed in inflamed tissues. The present study was designed to investigate whether stimulation of human colonic epithelial cells (HT-29 and Caco-2 cell lines) with NH2Cl affects nuclear speckles and their components. By indirect immunofluorescence, nuclear speckles have been shown to undergo rapid aggregation after NH2Cl stimulation. By utilizing Western blotting, SRp30 (a subset of SR proteins) in intestinal epithelial cells was found to be phosphorylated after NH2Cl treatment, whereas other SR proteins were not responsive to NH2Cl stimulation. The cytotoxic effect of NH2Cl was excluded by both negative lactate dehydrogenase assay and propidium iodide staining. Therefore, NH2Cl-induced morphological changes on nuclear speckles and phosphorylated SRp30 do not result from intestinal epithelial injury. Furthermore, the effect of NH2Cl on nuclear speckles and SRp30 was blocked by bisindolylmaleimide I, a selective PKC inhibitor. Together, the available data suggest that stimulation of intestinal epithelial cells with NH2Cl results in a consequent change on pre-mRNA splicing machinery via a distinctive signal pathway involving activation of PKC. This effect may contribute to oxidant-induced pathophysiological changes in the gastrointestinal tract.

scholarly journals Focal Laser Stimulation of Fly Nociceptors Activates Distinct Axonal and Dendritic Ca2+ Signals

2021 ◽  
Author(s):  
Rajshekhar Basak ◽  
Sabyasachi Sutradhar ◽  
Jonathon Howard
Keyword(s):  
Morphological Changes ◽  
Mechanical Stimuli ◽  
Direct Stimulation ◽  
Calcium Signals ◽  
Precise Position ◽  
Contact Pathway ◽  
Contact Response ◽  
Escape Behaviors ◽  
Class Iv ◽  
Stimulation Of

Drosophila Class IV neurons are polymodal nociceptors that detect noxious mechanical, thermal, optical and chemical stimuli. Escape behaviors in response to attacks by parasitoid wasps are dependent on Class IV cells, whose highly branched dendritic arbors form a fine meshwork that is thought to enable detection of the wasp's needle-like ovipositor barb. To understand how mechanical stimuli trigger cellular responses, we used a focused 405-nm laser to create highly local lesions to probe the precise position needed in evoke responses. By imaging calcium signals in dendrites, axons, and soma in response to stimuli of varying positions, intensities and spatial profiles, we discovered that there are two distinct nociceptive pathways. Direct stimulation to dendrites (the contact pathway) produces calcium responses in axons, dendrites and the cell body whereas stimulation adjacent to the dendrite (the non-contact pathway) produces calcium responses in the axons only. We interpret the non-contact pathway as damage to adjacent cells releasing diffusible molecules that act on the dendrites. Axonal responses have higher sensitivities and shorter latencies. In contrast, dendritic responses have lower sensitivities and longer latencies. Stimulation of finer, distal dendrites leads to smaller responses than stimulation of coarser, proximal dendrites, as expected if the contact response depends on the geometric overlap of the laser profile and the dendrite diameter. Because the axon signals to the CNS to trigger escape behaviors, we propose that the density of the dendritic meshwork is high not only to enable direct contact with the ovipositor, but also to enable neuronal activation via diffusing signals from damaged surrounding cells. Dendritic contact evokes responses throughout the dendritic arbor, even to regions distant and distal from the stimulus. These dendrite-wide calcium signals may facilitate hyperalgesia or cellular morphological changes following dendritic damage.

scholarly journals Rapid Magneto-Sonoporation of Adipose-Derived Cells

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4877
Author(s):  
Miriam Filippi ◽  
Boris Dasen ◽  
Arnaud Scherberich
Keyword(s):  
Stem Cells ◽  
Tissue Repair ◽  
Morphological Changes ◽  
Adipose Derived Stem Cells ◽  
Resonance Imaging ◽  
Membrane Resealing ◽  
First Time ◽  
Stimulation Of

By permeabilizing the cell membrane with ultrasound and facilitating the uptake of iron oxide nanoparticles, the magneto-sonoporation (MSP) technique can be used to instantaneously label transplantable cells (like stem cells) to be visualized via magnetic resonance imaging in vivo. However, the effects of MSP on cells are still largely unexplored. Here, we applied MSP to the widely applicable adipose-derived stem cells (ASCs) for the first time and investigated its effects on the biology of those cells. Upon optimization, MSP allowed us to achieve a consistent nanoparticle uptake (in the range of 10 pg/cell) and a complete membrane resealing in few minutes. Surprisingly, this treatment altered the metabolic activity of cells and induced their differentiation towards an osteoblastic profile, as demonstrated by an increased expression of osteogenic genes and morphological changes. Histological evidence of osteogenic tissue development was collected also in 3D hydrogel constructs. These results point to a novel role of MSP in remote biophysical stimulation of cells with focus application in bone tissue repair.

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