scholarly journals Caspase-8 goes cardiolipin: a new platform to provide mitochondria with microdomains of apoptotic signals?

2008 ◽  
Vol 183 (4) ◽  
pp. 579-581 ◽  
Author(s):  
Luca Scorrano
Keyword(s):  
Cell Biology ◽  
Second Messengers ◽  
Cell Types ◽  
Caspase 8 ◽  
Mitochondrial Membranes ◽  
Close Proximity ◽  
Effector Caspases ◽  
Extracellular Stimuli ◽  
Intracellular Target ◽  
Specific Lipid

In certain cell types, apoptosis in response to extracellular stimuli like Fas depends on a mitochondrial amplificatory loop: the apical caspase-8 cleaves and activates the BH3-only member of the Bcl-2 family BID. In turn, BID induces the release of cytochrome c from mitochondria to the cytoplasm, where it is required to fully activate effector caspases. In this issue of The Journal of Cell Biology, Gonzalvez et al. (see p. 681) show that when caspase-8 activation and production of functional BID is required, it is performed on mitochondrial platforms provided by the mitochondrion-specific lipid cardiolipin. Cardiolipin anchors caspase-8 at contact sites between inner and outer mitochondrial membranes, facilitating its self activation. These findings suggests that like other second messengers such as Ca2+ and cAMP, production of apoptotic messengers can be compartmentalized in close proximity to their intracellular target.

scholarly journals Morphological and Ultrastructural Characterization of Hemocytes in an Insect Model, the Hematophagous Dipetalogaster maxima (Hemiptera: Reduviidae)

Insects ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 640
Author(s):  
Natalia R. Moyetta ◽  
Fabián O. Ramos ◽  
Jimena Leyria ◽  
Lilián E. Canavoso ◽  
Leonardo L. Fruttero
Keyword(s):  
Cell Biology ◽  
Cell Types ◽  
Transmission Electron ◽  
Ultrastructural Characterization ◽  
Current Classification ◽  
Contrast Microscopy ◽  
First Time ◽  
Controversial Aspect

Hemocytes, the cells present in the hemolymph of insects and other invertebrates, perform several physiological functions, including innate immunity. The current classification of hemocyte types is based mostly on morphological features; however, divergences have emerged among specialists in triatomines, the insect vectors of Chagas’ disease (Hemiptera: Reduviidae). Here, we have combined technical approaches in order to characterize the hemocytes from fifth instar nymphs of the triatomine Dipetalogaster maxima. Moreover, in this work we describe, for the first time, the ultrastructural features of D. maxima hemocytes. Using phase contrast microscopy of fresh preparations, five hemocyte populations were identified and further characterized by immunofluorescence, flow cytometry and transmission electron microscopy. The plasmatocytes and the granulocytes were the most abundant cell types, although prohemocytes, adipohemocytes and oenocytes were also found. This work sheds light on a controversial aspect of triatomine cell biology and physiology setting the basis for future in-depth studies directed to address hemocyte classification using non-microscopy-based markers.

scholarly journals First blood: the endothelial origins of hematopoietic progenitors

Angiogenesis ◽  
2021 ◽  
Author(s):  
Giovanni Canu ◽  
Christiana Ruhrberg
Keyword(s):  
Stem Cells ◽  
Molecular Mechanisms ◽  
Vascular Endothelial Cells ◽  
Fetal Liver ◽  
Cell Types ◽  
Yolk Sac ◽  
Vascular Endothelial ◽  
Hematopoietic Stem ◽  
Close Proximity ◽  
Clinical Interest

AbstractHematopoiesis in vertebrate embryos occurs in temporally and spatially overlapping waves in close proximity to blood vascular endothelial cells. Initially, yolk sac hematopoiesis produces primitive erythrocytes, megakaryocytes, and macrophages. Thereafter, sequential waves of definitive hematopoiesis arise from yolk sac and intraembryonic hemogenic endothelia through an endothelial-to-hematopoietic transition (EHT). During EHT, the endothelial and hematopoietic transcriptional programs are tightly co-regulated to orchestrate a shift in cell identity. In the yolk sac, EHT generates erythro-myeloid progenitors, which upon migration to the liver differentiate into fetal blood cells, including erythrocytes and tissue-resident macrophages. In the dorsal aorta, EHT produces hematopoietic stem cells, which engraft the fetal liver and then the bone marrow to sustain adult hematopoiesis. Recent studies have defined the relationship between the developing vascular and hematopoietic systems in animal models, including molecular mechanisms that drive the hemato-endothelial transcription program for EHT. Moreover, human pluripotent stem cells have enabled modeling of fetal human hematopoiesis and have begun to generate cell types of clinical interest for regenerative medicine.

scholarly journals Desmosomal Molecules In and Out of Adhering Junctions: Normal and Diseased States of Epidermal, Cardiac and Mesenchymally Derived Cells

2010 ◽  
Vol 2010 ◽  
pp. 1-12 ◽  
Author(s):  
Sebastian Pieperhoff ◽  
Mareike Barth ◽  
Steffen Rickelt ◽  
Werner W. Franke
Keyword(s):  
Cell Biology ◽  
Cell Types ◽  
Cell Junctions ◽  
Surface Molecules ◽  
Transmembrane Glycoprotein ◽  
Current Cell ◽  
Plakophilin 2 ◽  
Definition Of ◽  
Adhering Junctions ◽  
Cell Cell

Current cell biology textbooks mention only two kinds of cell-to-cell adhering junctions coated with the cytoplasmic plaques: the desmosomes (maculae adhaerentes), anchoring intermediate-sized filaments (IFs), and the actin microfilament-anchoring adherens junctions (AJs), including both punctate (puncta adhaerentia) and elongate (fasciae adhaerentes) structures. In addition, however, a series of other junction types has been identified and characterized which contain desmosomal molecules but do not fit the definition of desmosomes. Of these special cell-cell junctions containing desmosomal glycoproteins or proteins we review the composite junctions (areae compositae) connecting the cardiomyocytes of mature mammalian hearts and their importance in relation to human arrhythmogenic cardiomyopathies. We also emphasize the various plakophilin-2-positive plaques in AJs (coniunctiones adhaerentes) connecting proliferatively active mesenchymally-derived cells, including interstitial cells of the heart and several soft tissue tumor cell types. Moreover, desmoplakin has also been recognized as a constituent of the plaques of thecomplexus adhaerentesconnecting certain lymphatic endothelial cells. Finally, we emphasize the occurrence of the desmosomal transmembrane glycoprotein, desmoglein Dsg2, out of the context of any junction as dispersed cell surface molecules in certain types of melanoma cells and melanocytes. This broadening of our knowledge on the diversity of AJ structures indicates that it may still be too premature to close the textbook chapters on cell-cell junctions.

scholarly journals Ubl4A is required for insulin-induced Akt plasma membrane translocation through promotion of Arp2/3-dependent actin branching

2015 ◽  
Vol 112 (31) ◽  
pp. 9644-9649 ◽  
Author(s):  
Yu Zhao ◽  
Yuting Lin ◽  
Honghong Zhang ◽  
Adriana Mañas ◽  
Wenwen Tang ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Glycogen Synthesis ◽  
Membrane Translocation ◽  
Insulin Stimulation ◽  
Serine Threonine Kinase ◽  
Newborn Mice ◽  
Threonine Kinase ◽  
Cell Mobility ◽  
Close Proximity ◽  
Extracellular Stimuli

The serine-threonine kinase Akt is a key regulator of cell proliferation and survival, glucose metabolism, cell mobility, and tumorigenesis. Activation of Akt by extracellular stimuli such as insulin centers on the interaction of Akt with PIP3 on the plasma membrane, where it is subsequently phosphorylated and activated by upstream protein kinases. However, it is not known how Akt is recruited to the plasma membrane upon stimulation. Here we report that ubiquitin-like protein 4A (Ubl4A) plays a crucial role in insulin-induced Akt plasma membrane translocation. Ubl4A knockout newborn mice have defective Akt-dependent glycogen synthesis and increased neonatal mortality. Loss of Ubl4A results in the impairment of insulin-induced Akt translocation to the plasma membrane and activation. Akt binds actin-filaments and colocalizes with actin-related protein 2 and 3 (Arp2/3) complex in the membrane ruffles and lamellipodia. Ubl4A directly interacts with Arp2/3 to accelerate actin branching and networking, allowing Akt to be in close proximity to the plasma membrane for activation upon insulin stimulation. Our finding reveals a new mechanism by which Akt is recruited to the plasma membrane for activation, thereby providing a missing link in Akt signaling.

scholarly journals Intercellular calcium signalling between chondrocytes and synovial cells in co-culture

1998 ◽  
Vol 329 (3) ◽  
pp. 681-687 ◽  
Author(s):  
Paola D'ANDREA ◽  
Alessandra CALABRESE ◽  
Micaela GRANDOLFO
Keyword(s):  
Gap Junctions ◽  
Intercellular Communication ◽  
Structural Changes ◽  
Articular Chondrocytes ◽  
Cell Metabolism ◽  
Second Messengers ◽  
Calcium Signalling ◽  
Cell Types ◽  
Synovial Cells ◽  
Cell Coupling

Intercellular communication allows the co-ordination of cell metabolism between tissues as well as sensitivity to extracellular stimuli. Paracrine stimulation and cell-to-cell coupling through gap junctions induce the formation of complex cellular networks that favour the intercellular exchange of nutrients and second messengers. Heterologous intercellular communication was studied in co-cultures of articular chondrocytes and HIG-82 synovial cells by measuring mechanically induced cytosolic changes in Ca2+ ion levels by digital fluorescence video imaging. In confluent co-cultures, mechanical stimulation induced intercellular Ca2+ waves that propagated to both cell types with similar kinetics. Intercellular wave spreading was inhibited by 18α-glycyrrhetinic acid and by treatments inhibiting the activation of purinoreceptors, suggesting that intercellular signalling between these two cell types occurs both through gap junctions and ATP-mediated paracrine stimulation. In rheumatoid arthritis the formation of the synovial pannus induces structural changes at the chondrosynovial junction, where chondrocyte and synovial cells come into close apposition: these results provide the first evidence for direct intercellular communication between these two cell types.

scholarly journals The cell biology of touch

2010 ◽  
Vol 191 (2) ◽  
pp. 237-248 ◽  
Author(s):  
Ellen A. Lumpkin ◽  
Kara L. Marshall ◽  
Aislyn M. Nelson
Keyword(s):  
Cell Biology ◽  
Cell Types ◽  
Evolutionary Approach ◽  
Mechanical Stimuli ◽  
Cellular Logic ◽  
Sense Of Touch

The sense of touch detects forces that bombard the body’s surface. In metazoans, an assortment of morphologically and functionally distinct mechanosensory cell types are tuned to selectively respond to diverse mechanical stimuli, such as vibration, stretch, and pressure. A comparative evolutionary approach across mechanosensory cell types and genetically tractable species is beginning to uncover the cellular logic of touch reception.

Subcellular localization of the Na+/H+ exchanger NHE1 in rat myocardium

1999 ◽  
Vol 276 (2) ◽  
pp. H709-H717 ◽  
Author(s):  
Kevin Petrecca ◽  
Roxana Atanasiu ◽  
Sergio Grinstein ◽  
John Orlowski ◽  
Alvin Shrier
Keyword(s):  
Connexin 43 ◽  
Cell Types ◽  
Ph Homeostasis ◽  
Adult Rat ◽  
Junction Protein ◽  
Close Proximity ◽  
Gap Junction Protein ◽  
Intercalated Disks ◽  
Distinct Distribution ◽  
Intercalated Disk

The Na+/H+exchanger NHE1 isoform is an integral component of cardiac intracellular pH homeostasis that is critically important for myocardial contractility. To gain further insight into its physiological significance, we determined its cellular distribution in adult rat heart by using immunohistochemistry and confocal microscopy. NHE1 was localized predominantly at the intercalated disk regions in close proximity to the gap junction protein connexin 43 of atrial and ventricular muscle cells. Significant labeling of NHE1 was also observed along the transverse tubular systems, but not the lateral sarcolemmal membranes, of both cell types. In contrast, the Na+-K+-ATPase α1-subunit was readily labeled by a specific mouse monoclonal antibody (McK1) along the entire ventricular sarcolemma and intercalated disks and, to a lesser extent, in the transverse tubules. These results indicate that NHE1 has a distinct distribution in heart and may fulfill specialized roles by selectively regulating the pH microenvironment of pH-sensitive proteins at the intercalated disks (e.g., connexin 43) and near the cytosolic surface of sarcoplasmic reticulum cisternae (e.g., ryanodine receptor), thereby influencing impulse conduction and excitation-contraction coupling.

scholarly journals The Winding Road of Cardiac Regeneration—Stem Cell Omics in the Spotlight

Cells ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 255 ◽  
Author(s):  
Miruna Mihaela Micheu ◽  
Alina Ioana Scarlatescu ◽  
Alexandru Scafa-Udriste ◽  
Maria Dorobantu
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Fate ◽  
Cell Biology ◽  
Molecular Mechanisms ◽  
Unmet Need ◽  
Cardiac Regeneration ◽  
Cell Types ◽  
Great Promise ◽  
Omics Data

Despite significant progress in treating ischemic cardiac disease and succeeding heart failure, there is still an unmet need to develop effective therapeutic strategies given the persistent high-mortality rate. Advances in stem cell biology hold great promise for regenerative medicine, particularly for cardiac regeneration. Various cell types have been used both in preclinical and clinical studies to repair the injured heart, either directly or indirectly. Transplanted cells may act in an autocrine and/or paracrine manner to improve the myocyte survival and migration of remote and/or resident stem cells to the site of injury. Still, the molecular mechanisms regulating cardiac protection and repair are poorly understood. Stem cell fate is directed by multifaceted interactions between genetic, epigenetic, transcriptional, and post-transcriptional mechanisms. Decoding stem cells’ “panomic” data would provide a comprehensive picture of the underlying mechanisms, resulting in patient-tailored therapy. This review offers a critical analysis of omics data in relation to stem cell survival and differentiation. Additionally, the emerging role of stem cell-derived exosomes as “cell-free” therapy is debated. Last but not least, we discuss the challenges to retrieve and analyze the huge amount of publicly available omics data.

scholarly journals Effect of glyprolines on serum caspase levels under “social” stress

2021 ◽  
Vol 24 (2) ◽  
pp. 46-52
Author(s):  
Anna L. Yasenyavskaya ◽  
Alexandra A. Tsibizova ◽  
Lyudmila A. Andreeva ◽  
Nikolay F. Myasoedov ◽  
Olga A. Bashkina ◽  
...  
Keyword(s):  
Blood Serum ◽  
Social Stress ◽  
Caspase 3 ◽  
Male Rats ◽  
Laboratory Animals ◽  
Caspase 8 ◽  
Elisa Kit ◽  
White Rats ◽  
Effector Caspases ◽  
Adhesive Proteins

Objective. To investigate the effect of glyprolines on the levels of initiating and effector caspases in the serum of white rats under "social" stress. Materials and methods. The study was conducted on 90 white male rats of 6 months of age. All manipulations with animals were carried out in accordance with international and domestic requirements for working with laboratory animals. When modeling "social" stress, groups of animals with aggressive and submissive behavior were formed. Laboratory animals, taking into account the types of behavior, were divided into groups (n=10): a group of intact males (control); a group of animals exposed to" social " stress for 20 days (stress); groups of individuals who received intraperitoneal Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro), Pro-Gly-Pro, Pro-Gly-Pro-Leu at doses of 100 mcg/kg / day from the 1st day of stress exposure within a 20- day course. The effect of neuropeptides on the activity of apoptosis processes was evaluated by determining the level of initiating and effector caspases (caspase-8 and caspase-3) (ELISA Kit for Caspase-8 and ELISA Kit for Caspase-3; USA) in the blood serum of white rats by enzyme immunoassay. Results. According to the results of the study, it was found that under conditions of "social" stress, an increase in apoptotic processes was observed, accompanied by an increase in the level of caspase-3 and caspase-8 in the blood serum of white rats. The introduction of the studied compounds against the background of stress contributed to a decrease in the level of the studied indicators, which is most likely due to the presence of antiapoptotic action in glyprolins due to inhibition of the caspase-dependent cascade of apoptosis reactions, as a result of which the destruction of cellular structures occurs by hydrolysis of nuclear lamina, cleavage of adhesive proteins, destruction of the cytoskeleton. Conclusion. Thus, the conducted study established the presence of Thr-Lys-Pro-Arg-Pro-Gly-Pro (Selank), Pro-Gly-Pro and Pro-Gly-Pro-Leu under conditions of stress-induced antiapoptotic activity due to inhibition of the caspase-dependent cascade of apoptosis reactions.

scholarly journals The organisation and functions of local Ca2+ signals

2001 ◽  
Vol 114 (12) ◽  
pp. 2213-2222 ◽  
Author(s):  
Martin D. Bootman ◽  
Peter Lipp ◽  
Michael J. Berridge
Keyword(s):  
Cell Proliferation ◽  
Gene Transcription ◽  
Cell Biology ◽  
Building Blocks ◽  
Cell Types ◽  
Diverse Range ◽  
Cellular Processes ◽  
Different Cell Types ◽  
Intracellular Messenger ◽  
Sensory Mechanisms

Calcium (Ca2+) is a ubiquitous intracellular messenger, controlling a diverse range of cellular processes, such as gene transcription, muscle contraction and cell proliferation. The ability of a simple ion such as Ca2+ to play a pivotal role in cell biology results from the facility that cells have to shape Ca2+ signals in space, time and amplitude. To generate and interpret the variety of observed Ca2+ signals, different cell types employ components selected from a Ca2+ signalling ‘toolkit’, which comprises an array of homeostatic and sensory mechanisms. By mixing and matching components from the toolkit, cells can obtain Ca2+ signals that suit their physiology. Recent studies have demonstrated the importance of local Ca2+ signals in defining the specificity of the interaction of Ca2+ with its targets. Furthermore, local Ca2+ signals are the triggers and building blocks for larger global signals that propagate throughout cells.

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