Role of Calcium Ions and the Phospholipids in the Prolactin Regulation of Its Target Cells

2018 ◽  
pp. 107-119
Author(s):  
James A. Rillema
Keyword(s):  
Calcium Ions ◽  
Target Cells

Mitochondrial matrix calcium ions regulate energy production in myocardium: A cytochemical study

1990 ◽  
Vol 48 (2) ◽  
pp. 166-167
Author(s):  
W.A. Jacob ◽  
R. Hertsens ◽  
A. Van Bogaert ◽  
M. De Smet
Keyword(s):  
Energy Metabolism ◽  
Calcium Ions ◽  
Energy Production ◽  
Regulation Of Respiration ◽  
Free Calcium ◽  
Mitochondrial Matrix ◽  
Cytochemical Study ◽  
Nmr Techniques

In the past most studies of the control of energy metabolism focus on the role of the phosphorylation potential ATP/ADP.Pi on the regulation of respiration. Studies using NMR techniques have demonstrated that the concentrations of these compounds for oxidation phosphorylation do not change appreciably throughout the cardiac cycle and during increases in cardiac work. Hence regulation of energy production by calcium ions, present in the mitochondrial matrix, has been the object of a number of recent studies.Three exclusively intramitochondnal dehydrogenases are key enzymes for the regulation of oxidative metabolism. They are activated by calcium ions in the low micromolar range. Since, however, earlier estimates of the intramitochondnal calcium, based on equilibrium thermodynamic considerations, were in the millimolar range, a physiological correlation was not evident. The introduction of calcium-sensitive probes fura-2 and indo-1 made monitoring of free calcium during changing energy metabolism possible. These studies were performed on isolated mitochondria and extrapolation to the in vivo situation is more or less speculative.

STEROID HORMONE METABOLISM IN RESPONSIVE TISSUES IN VITRO

1971 ◽  
Vol 68 (1_Suppl) ◽  
pp. S279-S294 ◽  
Author(s):  
Paul Robel
Keyword(s):  
Steroid Hormone ◽  
Physiological Activity ◽  
Physiological State ◽  
Target Cells ◽  
Target Tissue ◽  
Hormone Metabolism ◽  
Metabolizing Enzymes ◽  
Relationship Of

ABSTRACT Of the information available on steroid hormone metabolism in responsive tissues, only that relating hormone metabolism to physiological activity is reviewed, i. e. metabolite activity in isolated in vitro systems, binding of metabolites to target tissue receptors, specific steroid hormone metabolizing enzymes and relationship of hormone metabolism to target organ physiological state. Further, evidence is presented in the androgen field, demonstrating 5α-reduced metabolites, formed inside the target cells, as active compounds. This has led to a consideration of testosterone as a »prehormone«. The possibility that similar events take place in tissues responding to progesterone is discussed. Finally, the role of hormone metabolism in the regulation of hormone availability and/or renewal in target cells is discussed. In this context, reference is made to the potential role of plasma binding proteins and cytosol receptors.

Neurotoxic and Neuroprotective Role of Exosomes in Parkinson’s Disease

2020 ◽  
Vol 25 (42) ◽  
pp. 4510-4522 ◽  
Author(s):  
Biancamaria Longoni ◽  
Irene Fasciani ◽  
Shivakumar Kolachalam ◽  
Ilaria Pietrantoni ◽  
Francesco Marampon ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Potential Role ◽  
Current Knowledge ◽  
Biological Fluids ◽  
Cell Communication ◽  
Target Cells ◽  
Cellular Debris ◽  
The Brain

: Exosomes are extracellular vesicles produced by eukaryotic cells that are also found in most biological fluids and tissues. While they were initially thought to act as compartments for removal of cellular debris, they are now recognized as important tools for cell-to-cell communication and for the transfer of pathogens between the cells. They have attracted particular interest in neurodegenerative diseases for their potential role in transferring prion-like proteins between neurons, and in Parkinson’s disease (PD), they have been shown to spread oligomers of α-synuclein in the brain accelerating the progression of this pathology. A potential neuroprotective role of exosomes has also been equally proposed in PD as they could limit the toxicity of α-synuclein by clearing them out of the cells. Exosomes have also attracted considerable attention for use as drug vehicles. Being nonimmunogenic in nature, they provide an unprecedented opportunity to enhance the delivery of incorporated drugs to target cells. In this review, we discuss current knowledge about the potential neurotoxic and neuroprotective role of exosomes and their potential application as drug delivery systems in PD.

scholarly journals The Potential Role of Exosomes in Child and Adolescent Obesity

Children ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 196
Author(s):  
Ioanna Maligianni ◽  
Christos Yapijakis ◽  
Flora Bacopoulou ◽  
George Chrousos
Keyword(s):  
Child And Adolescent ◽  
Cardiovascular Complications ◽  
Adolescent Obesity ◽  
Overweight And Obesity ◽  
Calorie Intake ◽  
Target Cells ◽  
Special Role ◽  
Exosomal Mirnas ◽  
Risk Biomarkers

Child and adolescent obesity constitute one of the greatest contemporary public health menaces. The enduring disproportion between calorie intake and energy consumption, determined by a complex interaction of genetic, epigenetic, and environmental factors, finally leads to the development of overweight and obesity. Child and adolescent overweight/obesity promotes smoldering systemic inflammation (“para-inflammation”) and increases the likelihood of later metabolic and cardiovascular complications, including metabolic syndrome and its components, which progressively deteriorate during adulthood. Exosomes are endosome-derived extracellular vesicles that are secreted by a variety of cells, are naturally taken-up by target cells, and may be involved in many physiological and pathological processes. Over the last decade, intensive research has been conducted regarding the special role of exosomes and the non-coding (nc) RNAs they contain (primarily micro (mi) RNAs, long (l) non-coding RNAs, messenger (m) RNAs and other molecules) in inter-cellular communications. Through their action as communication mediators, exosomes may contribute to the pathogenesis of obesity and associated disorders. There is increasing evidence that exosomal miRNAs and lncRNAs are involved in pivotal processes of adipocyte biology and that, possibly, play important roles in gene regulation linked to human obesity. This review aims to improve our understanding of the roles of exosomes and their cargo in the development of obesity and related metabolic and inflammatory disorders. We examined their potential roles in adipose tissue physiology and reviewed the scarce data regarding the altered patterns of circulating miRNAs and lncRNAs observed in obese children and adolescents, compared them to the equivalent, more abundant existing findings of adult studies, and speculated on their proposed mechanisms of action. Exosomal miRNAs and lncRNAs could be applied as cardiometabolic risk biomarkers, useful in the early diagnosis and prevention of obesity. Furthermore, the targeting of crucial circulating exosomal cargo to tissues involved in the pathogenesis and maintenance of obesity could provide a novel therapeutic approach to this devastating and management-resistant pandemic.

scholarly journals GSK-3α Inhibition in Drug-Resistant CML Cells Promotes Susceptibility to NK Cell-Mediated Lysis in an NKG2D- and NKp30-Dependent Manner

Cancers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1802
Author(s):  
Nayoung Kim ◽  
Mi Yeon Kim ◽  
Woo Seon Choi ◽  
Eunbi Yi ◽  
Hyo Jung Lee ◽  
...  
Keyword(s):  
Nk Cells ◽  
Nk Cell ◽  
Negative Regulator ◽  
Target Cells ◽  
Dependent Manner ◽  
Cell Functions ◽  
Cell Based Therapy ◽  
Activating Receptors ◽  
Gsk 3Β

Natural killer (NK) cells are innate cytotoxic lymphocytes that provide early protection against cancer. NK cell cytotoxicity against cancer cells is triggered by multiple activating receptors that recognize specific ligands expressed on target cells. We previously demonstrated that glycogen synthase kinase (GSK)-3β, but not GSK-3α, is a negative regulator of NK cell functions via diverse activating receptors, including NKG2D and NKp30. However, the role of GSK-3 isoforms in the regulation of specific ligands on target cells is poorly understood, which remains a challenge limiting GSK-3 targeting for NK cell-based therapy. Here, we demonstrate that GSK-3α rather than GSK-3β is the primary isoform restraining the expression of NKG2D ligands, particularly ULBP2/5/6, on tumor cells, thereby regulating their susceptibility to NK cells. GSK-3α also regulated the expression of the NKp30 ligand B7-H6, but not the DNAM-1 ligands PVR or nectin-2. This regulation occurred independently of BCR-ABL1 mutation that confers tyrosine kinase inhibitor (TKI) resistance. Mechanistically, an increase in PI3K/Akt signaling in concert with c-Myc was required for ligand upregulation in response to GSK-3α inhibition. Importantly, GSK-3α inhibition improved cancer surveillance by human NK cells in vivo. Collectively, our results highlight the distinct role of GSK-3 isoforms in the regulation of NK cell reactivity against target cells and suggest that GSK-3α modulation could be used to enhance tumor cell susceptibility to NK cells in an NKG2D- and NKp30-dependent manner.

scholarly journals Role of antigen, CD8, and cytotoxic T lymphocyte (CTL) avidity in high dose antigen induction of apoptosis of effector CTL.

1996 ◽  
Vol 184 (2) ◽  
pp. 485-492 ◽  
Author(s):  
M A Alexander-Miller ◽  
G R Leggatt ◽  
A Sarin ◽  
J A Berzofsky
Keyword(s):  
T Lymphocytes ◽  
Cytotoxic T Lymphocyte ◽  
Target Cells ◽  
High Dose ◽  
High Avidity ◽  
Apoptotic Pathway ◽  
Peptide Antigen ◽  
Kinetics Of ◽  
Selection Of

Experimental data suggest that negative selection of thymocytes can occur as a result of supraoptimal antigenic stimulation. It is unknown, however, whether such mechanisms are at work in mature CD8+ T lymphocytes. Here, we show that CD8+ effector cytotoxic T lymphocytes (CTL) are susceptible to proliferative inhibition by high dose peptide antigen, leading to apoptotic death mediated by TNF-alpha release. Such inhibition is not reflected in the cytolytic potential of the CTL, since concentrations of antigen that are inhibitory for proliferation promote efficient lysis of target cells. Thus, although CTL have committed to the apoptotic pathway, the kinetics of this process are such that CTL function can occur before death of the CTL. The concentration of antigen required for inhibition is a function of the CTL avidity, in that concentrations of antigen capable of completely inhibiting high avidity CTL maximally stimulate low avidity CTL. Importantly, the inhibition can be detected in both activated and resting CTL. Blocking studies demonstrate that the CD8 molecule contributes significantly to the inhibitory signal as the addition of anti-CD8 antibody restores the proliferative response. Thus, our data support the model that mature CD8+ CTL can accommodate an activation signal of restricted intensity, which, if surpassed, results in deletion of that cell.

scholarly journals Private specificities of H-2K and H-2D loci as possible selective targets for effector lymphocytes in cell-mediated immunity.

1975 ◽  
Vol 141 (1) ◽  
pp. 11-26 ◽  
Author(s):  
B D Brondz ◽  
I K Egorov ◽  
G I Drizlikh
Keyword(s):  
T Lymphocytes ◽  
Target Cells ◽  
Cell Mediated Immunity ◽  
Skin Grafts ◽  
Immune Lymphocytes ◽  
Direct Cytotoxicity ◽  
Cross Absorption ◽  
Private Specificity ◽  
Two Populations

Receptors of effector T lymphocytes of congeneic strains of mice do not recognize public H-2 specificities and react to private H-2 specificities only. This has been established with the use of three tests: direct cytotoxicity assay of immune lymphocytes upon target cells, specific absorption of the lymphocytes on the target cells, and rejection of skin grafts at an accelerated fashion. Immunization with two private H-2 specificities in the system C57BL/10ScSn leads to B10.D2 induces formation of two corresponding populations of effector lymphocytes in unequal proportion: a greater part of them is directed against the private specificity H-2.33 (Kb), while the smaller part is towards H-2.2 (Db) private specificity. These two populations of effector lymphocytes do not overlap, as demonstrated by experiments on their cross-absorption on B10.D2 (R107), B10.D2 (R101), B10.A(2R), and B10.A(5R) target cells, as well as on mixtures of R107 and R101 targets. Following removal of lymphocytes reacting with one of the private H-2 specificities, lymphocytes specific to the other specificity are fully maintained. A mixture of target cells, each bearing one of the two immunizing private specificities, absorbs 100% of the immune lymphocytes and is totally destroyed by them. It is suggested that H-2 antigens are natural complexes of hapten-carrier type, in which the role of hapten is played by public H-2 specifities and that of the carrier determinant by either private H-2 specificities or structures closely linked to them. Various models of steric arrangement of MHC determinants recognized by receptors of effector T lymphocytes are discussed.

Mise en évidence du rôle, dans la régénération des Amphibiens, d'une glycoprotéine sécrétée par la cape apicale: étude cytochimique et autoradiographique en microscopie électronique

Development ◽  
1974 ◽  
Vol 32 (1) ◽  
pp. 133-145
Author(s):  
Par Claude Chapron
Keyword(s):  
High Resolution ◽  
Epithelial Cells ◽  
Limb Regeneration ◽  
Target Cells ◽  
Silver Particles ◽  
Electron Microscopic ◽  
Microscopic Studies ◽  
High Resolution Autoradiography

Evidence for the role of an apical cap glycoprotein in amphibian regeneration: cytochemical and autoradiographic electron-microscopic studies Early during limb regeneration in the newt, an ectodermal apical cap covering a mesodermal blastema is formed. High-resolution autoradiography of these tissues has been carried out after incorporation of [3H]fucose, which is a precursor of glycoproteins. Autoradiography shows that silver particles are located at first on epithelial cells, then on mesenchymatous cells. This observation is consistent with a hypothesis in which the apical cap would elaborate a glycoprotein acting on the blastema. Substructural autoradiography and cytochemistry also show the importance of cellular surfaces for both cells producing glycoprotein and those which are target cells.

An Overview of the Latest Applications of Platelet-Derived Microparticles and Nanoparticles in Medical Technology 2010-2020

2021 ◽  
Vol 21 ◽  
Author(s):  
Tahereh Zadeh Mehrizi
Keyword(s):  
Drug Delivery ◽  
Cell Types ◽  
Current Status ◽  
Target Cells ◽  
Interesting Point ◽  
Large Size ◽  
Review Study ◽  
Cellular Pathways ◽  
Different Cell Types

: Today, Platelets and platelet-derived nanoparticles and microparticles have found many applications in nanomedical technology. The results of our review study show that no article has been published in this field to review the current status of applications of these platelet derivatives so far. Therefore, in present study, our goal is to compare the applications of platelet derivatives and review their latest status between 2010 and 2020 to present the latest findings to researchers. A very interesting point about the role of platelet derivatives is the presence of molecules on their surface which makes them capable of hiding from the immune system, reaching different target cells, and specifically attaching to different cell types. According to the results of this study, most of their applications include drug delivery, diagnosis of various diseases, and tissue engineering. However, their application in drug delivery is limited due to heterogeneity, large size, and the possibility of interference with cellular pathways in microparticles derived from other cells. On the other hand, platelet nanoparticles are more controllable and have been widely used for drug delivery in treatment of cancer, atherosclerosis, thrombosis, infectious diseases, repair of damaged tissue, and photothermal therapy. The results of this study show that platelet nanoparticles are more controllable than platelet microparticles and have a higher potential for use in medicine.

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