scholarly journals Imaging calcium microdomains within entire astrocyte territories and endfeet with GCaMPs expressed using adeno-associated viruses

2013 ◽  
Vol 141 (5) ◽  
pp. 633-647 ◽  
Author(s):  
Eiji Shigetomi ◽  
Eric A. Bushong ◽  
Martin D. Haustein ◽  
Xiaoping Tong ◽  
Olan Jackson-Weaver ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Hippocampal Slices ◽  
Adult Mice ◽  
Neuronal Synapses ◽  
Primary Signal ◽  
Experimental Approaches ◽  
Acute Hippocampal Slices

Intracellular Ca2+ transients are considered a primary signal by which astrocytes interact with neurons and blood vessels. With existing commonly used methods, Ca2+ has been studied only within astrocyte somata and thick branches, leaving the distal fine branchlets and endfeet that are most proximate to neuronal synapses and blood vessels largely unexplored. Here, using cytosolic and membrane-tethered forms of genetically encoded Ca2+ indicators (GECIs; cyto-GCaMP3 and Lck-GCaMP3), we report well-characterized approaches that overcome these limitations. We used in vivo microinjections of adeno-associated viruses to express GECIs in astrocytes and studied Ca2+ signals in acute hippocampal slices in vitro from adult mice (aged ∼P80) two weeks after infection. Our data reveal a sparkling panorama of unexpectedly numerous, frequent, equivalently scaled, and highly localized Ca2+ microdomains within entire astrocyte territories in situ within acute hippocampal slices, consistent with the distribution of perisynaptic branchlets described using electron microscopy. Signals from endfeet were revealed with particular clarity. The tools and experimental approaches we describe in detail allow for the systematic study of Ca2+ signals within entire astrocytes, including within fine perisynaptic branchlets and vessel-associated endfeet, permitting rigorous evaluation of how astrocytes contribute to brain function.

scholarly journals Экспериментальные модели сократительной активности миометрия

2020 ◽  
Author(s):  
A.A. Yakovleva ◽  
N.G. Pavlova
Keyword(s):  
In Silico ◽  
Contractile Activity ◽  
Experimental Models ◽  
Pacemaker Activity ◽  
Single View ◽  
Uterine Contractile ◽  
Experimental Approaches

Сократительная деятельность матки до настоящего времени остается актуальным вопросом фундаментальных исследований, поскольку отсутствуют единые представления о биомеханике маточного сокращения, необходимые для профилактики родового и акушерского травматизма. Цель работы - оценка ограничений и возможностей экспериментальных моделей, предназначенных для изучения сократительной активности миометрия. Методика. Основными экспериментальными подходами к изучению сократительной активности матки являлись исследования in vitro, in situ, in vivo, in silico, а также их сочетание. Результаты. В статье рассмотрены исследования, в которых использованы различные сочетания экспериментальных подходов, обсуждаются результаты, полученные при моделировании в экспериментах, обсуждаются результаты изучения синхронизации сокращения отделов матки на различных моделях, а также результаты исследования пейсмейкерной активности миометрия и возможность экстраполяции полученных данных на человека. В связи с активным развитием компьютерных технологий в статье поднимается вопрос об их использовании в моделировании сократительной активности матки человека. Заключение. Делается заключение, что комплексный подход, включающий электромиографические, биохимические и морфологические исследования в хроническом эксперименте, является наиболее адекватным для изучения сократительной активности миометрия и функционального состояния нормально развитых и отставших в развитии плодов, что позволит разработать комплексные методы профилактики родового и акушерского травматизма.Uterine contractile activity remains an important issue of fundamental research as there is no single view of the biomechanics of uterine contraction necessary for the prevention of parturition and obstetric trauma until now. The aim of the review was to assess advantages and limitations of experimental models described in the literature for study uterine contractile activity. At the present time main experimental approaches for study myometrium contractile activity are research in vitro, in situ, in vivo, in silico and the their combinations. The literature presents experimental approaches, different models of uterine contractions synchronization and study of myometrium pacemaker activity. Due to active development of computer technologies there is a need to model human uterine contractile activity with a simplified anatomy. The authors propose that combination of electromyographic, biochemical and morphological methods in chronic experiment is the most correct and appropriate direction for the assessment of the myometrium contractile activity and functional state of normally developed and growth restricted fetuses.

scholarly journals Stringent structural plasticity of dendritic spines revealed by two-photon glutamate uncaging in adult mouse neocortex in vivo

2019 ◽  
Author(s):  
Jun Noguchi ◽  
Akira Nagaoka ◽  
Tatsuya Hayama ◽  
Hasan Ucar ◽  
Sho Yagishita ◽  
...  
Keyword(s):  
Time Course ◽  
Hippocampal Slices ◽  
Low Frequency ◽  
Structural Plasticity ◽  
Two Photon ◽  
Low Magnesium ◽  
Adult Mice ◽  
First Time

AbstractTwo-photon uncaging of glutamate is widely utilized to characterize structural plasticity in brain slice preparations in vitro. In this study, we investigated spine plasticity by using, for the first time, glutamate uncaging in the neocortex of adult mice in vivo. Spine enlargement was successfully induced in a smaller fraction of spines in the neocortex (22%) than in young hippocampal slices (95%), even under a low magnesium condition. Once induced, the time course and mean amplitudes of long-term enlargement were the same (81%) as those in vitro. However, low-frequency (1–2 Hz) glutamate uncaging caused spine shrinkage in a similar fraction (34%) of spines as in vitro, but spread to the neighboring spines less frequently than in vitro. Thus, we found that structural plasticity can occur similarly in the adult neocortex in vivo as in the hippocampus in vitro, although it happens stringently in a smaller subset of spines.

scholarly journals NH4+ triggers the release of astrocytic lactate via mitochondrial pyruvate shunting

2015 ◽  
Vol 112 (35) ◽  
pp. 11090-11095 ◽  
Author(s):  
Rodrigo Lerchundi ◽  
Ignacio Fernández-Moncada ◽  
Yasna Contreras-Baeza ◽  
Tamara Sotelo-Hitschfeld ◽  
Philipp Mächler ◽  
...  
Keyword(s):  
Aerobic Glycolysis ◽  
Hippocampal Slices ◽  
Lactate Production ◽  
Glucose Consumption ◽  
Oxygen Metabolism ◽  
Acute Increase ◽  
Excitatory Neurotransmission ◽  
Acute Hippocampal Slices

Neural activity is accompanied by a transient mismatch between local glucose and oxygen metabolism, a phenomenon of physiological and pathophysiological importance termed aerobic glycolysis. Previous studies have proposed glutamate and K+ as the neuronal signals that trigger aerobic glycolysis in astrocytes. Here we used a panel of genetically encoded FRET sensors in vitro and in vivo to investigate the participation of NH4+, a by-product of catabolism that is also released by active neurons. Astrocytes in mixed cortical cultures responded to physiological levels of NH4+ with an acute rise in cytosolic lactate followed by lactate release into the extracellular space, as detected by a lactate-sniffer. An acute increase in astrocytic lactate was also observed in acute hippocampal slices exposed to NH4+ and in the somatosensory cortex of anesthetized mice in response to i.v. NH4+. Unexpectedly, NH4+ had no effect on astrocytic glucose consumption. Parallel measurements showed simultaneous cytosolic pyruvate accumulation and NADH depletion, suggesting the involvement of mitochondria. An inhibitor-stop technique confirmed a strong inhibition of mitochondrial pyruvate uptake that can be explained by mitochondrial matrix acidification. These results show that physiological NH4+ diverts the flux of pyruvate from mitochondria to lactate production and release. Considering that NH4+ is produced stoichiometrically with glutamate during excitatory neurotransmission, we propose that NH4+ behaves as an intercellular signal and that pyruvate shunting contributes to aerobic lactate production by astrocytes.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

Evaluation of Structure-Controlled Silk Fibroin Coatings for Orthopedic Infection and In-Situ Osteogenesis: In Vitro and In Vivo

2020 ◽  
Author(s):  
Wenhao Zhou ◽  
Teng Zhang ◽  
Jianglong Yan ◽  
QiYao Li ◽  
Panpan Xiong ◽  
...  
Keyword(s):  
Silk Fibroin ◽  
Orthopedic Infection

scholarly journals Development of In Situ Self-Assembly Nanoparticles to Encapsulate Lopinavir and Ritonavir for Long-Acting Subcutaneous Injection

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 904
Author(s):  
Irin Tanaudommongkon ◽  
Asama Tanaudommongkon ◽  
Xiaowei Dong
Keyword(s):  
Sustained Release ◽  
Trough Concentration ◽  
Self Assembly ◽  
Subcutaneous Injection ◽  
Drug Loading ◽  
Entrapment Efficiency ◽  
Long Acting

Most antiretroviral medications for human immunodeficiency virus treatment and prevention require high levels of patient adherence, such that medications need to be administered daily without missing doses. Here, a long-acting subcutaneous injection of lopinavir (LPV) in combination with ritonavir (RTV) using in situ self-assembly nanoparticles (ISNPs) was developed to potentially overcome adherence barriers. The ISNP approach can improve the pharmacokinetic profiles of the drugs. The ISNPs were characterized in terms of particle size, drug entrapment efficiency, drug loading, in vitro release study, and in vivo pharmacokinetic study. LPV/RTV ISNPs were 167.8 nm in size, with a polydispersity index of less than 0.35. The entrapment efficiency was over 98% for both LPV and RTV, with drug loadings of 25% LPV and 6.3% RTV. A slow release rate of LPV was observed at about 20% on day 5, followed by a sustained release beyond 14 days. RTV released faster than LPV in the first 5 days and slower than LPV thereafter. LPV trough concentration remained above 160 ng/mL and RTV trough concentration was above 50 ng/mL after 6 days with one subcutaneous injection. Overall, the ISNP-based LPV/RTV injection showed sustained release profiles in both in vitro and in vivo studies.

scholarly journals Establishment of MHHi001-A-5, a GCaMP6f and RedStar dual reporter human iPSC line for in vitro and in vivo characterization and in situ tracing of iPSC derivatives

2021 ◽  
Vol 52 ◽  
pp. 102206
Author(s):  
Alexandra Haase ◽  
Tim Kohrn ◽  
Veronika Fricke ◽  
Maria Elena Ricci Signorini ◽  
Merlin Witte ◽  
...  
Keyword(s):  
Ipsc Line ◽  
Dual Reporter ◽  
In Vivo Characterization ◽  
Human Ipsc

scholarly journals Enlisting the Ixodes scapularis Embryonic ISE6 Cell Line to Investigate the Neuronal Basis of Tick—Pathogen Interactions

Pathogens ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 70
Author(s):  
Lourdes Mateos-Hernández ◽  
Natália Pipová ◽  
Eléonore Allain ◽  
Céline Henry ◽  
Clotilde Rouxel ◽  
...  
Keyword(s):  
Cell Line ◽  
Peripheral Nerves ◽  
Ixodes Scapularis ◽  
Embryonic Cell ◽  
Cell Subpopulation ◽  
In Vivo Experiments

Neuropeptides are small signaling molecules expressed in the tick central nervous system, i.e., the synganglion. The neuronal-like Ixodes scapularis embryonic cell line, ISE6, is an effective tool frequently used for examining tick–pathogen interactions. We detected 37 neuropeptide transcripts in the I. scapularis ISE6 cell line using in silico methods, and six of these neuropeptide genes were used for experimental validation. Among these six neuropeptide genes, the tachykinin-related peptide (TRP) of ISE6 cells varied in transcript expression depending on the infection strain of the tick-borne pathogen, Anaplasma phagocytophilum. The immunocytochemistry of TRP revealed cytoplasmic expression in a prominent ISE6 cell subpopulation. The presence of TRP was also confirmed in A. phagocytophilum-infected ISE6 cells. The in situ hybridization and immunohistochemistry of TRP of I. scapularis synganglion revealed expression in distinct neuronal cells. In addition, TRP immunoreaction was detected in axons exiting the synganglion via peripheral nerves as well as in hemal nerve-associated lateral segmental organs. The characterization of a complete Ixodes neuropeptidome in ISE6 cells may serve as an effective in vitro tool to study how tick-borne pathogens interact with synganglion components that are vital to tick physiology. Therefore, our current study is a potential stepping stone for in vivo experiments to further examine the neuronal basis of tick–pathogen interactions.

scholarly journals Discovery of vanoxerine dihydrochloride as a CDK2/4/6 triple-inhibitor for the treatment of human hepatocellular carcinoma

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Ying Zhu ◽  
Kun-Bin Ke ◽  
Zhong-Kun Xia ◽  
Hong-Jian Li ◽  
Rong Su ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Cycle Progression ◽  
G1 Arrest ◽  
Huh7 Cells ◽  
Synergistic Cytotoxicity ◽  
Combination Study ◽  
Experimental Approaches ◽  
Induced Apoptosis

Abstract Background Cyclin-dependent kinases 2/4/6 (CDK2/4/6) play critical roles in cell cycle progression, and their deregulations are hallmarks of hepatocellular carcinoma (HCC). Methods We used the combination of computational and experimental approaches to discover a CDK2/4/6 triple-inhibitor from FDA approved small-molecule drugs for the treatment of HCC. Results We identified vanoxerine dihydrochloride as a new CDK2/4/6 inhibitor, and a strong cytotoxicdrugin human HCC QGY7703 and Huh7 cells (IC50: 3.79 μM for QGY7703and 4.04 μM for Huh7 cells). In QGY7703 and Huh7 cells, vanoxerine dihydrochloride treatment caused G1-arrest, induced apoptosis, and reduced the expressions of CDK2/4/6, cyclin D/E, retinoblastoma protein (Rb), as well as the phosphorylation of CDK2/4/6 and Rb. Drug combination study indicated that vanoxerine dihydrochloride and 5-Fu produced synergistic cytotoxicity in vitro in Huh7 cells. Finally, in vivo study in BALB/C nude mice subcutaneously xenografted with Huh7 cells, vanoxerine dihydrochloride (40 mg/kg, i.p.) injection for 21 days produced significant anti-tumor activity (p < 0.05), which was comparable to that achieved by 5-Fu (10 mg/kg, i.p.), with the combination treatment resulted in synergistic effect. Immunohistochemistry staining of the tumor tissues also revealed significantly reduced expressions of Rb and CDK2/4/6in vanoxerinedihydrochloride treatment group. Conclusions The present study isthe first report identifying a new CDK2/4/6 triple inhibitor vanoxerine dihydrochloride, and demonstrated that this drug represents a novel therapeutic strategy for HCC treatment.

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