排序方式: 共有72条查询结果,搜索用时 15 毫秒
1.
Donato Santovito Virginia Egea Kiril Bidzhekov Lucia Natarelli Andr Mouro Xavier Blanchet Kanin Wichapong Maria Aslani Coy Brunßen Michael Horckmans Michael Hristov Arie Geerlof Esther Lutgens Mat J. A. P. Daemen Tilman Hackeng Christian Ries Triantafyllos Chavakis Henning Morawietz Ronald Naumann Philipp Von Hundelshausen Sabine Steffens Johan Duchêne Remco T. A. Megens Michael Sattler Christian Weber 《Autophagy》2020,16(12):2294
2.
Transient receptor potential melastatin 2 (TRPM2), a Ca2+-permeable cation channel implicated in postischemic neuronal cell death, leukocyte activation, and insulin secretion, is activated by intracellular ADP ribose (ADPR). In addition, the pyridine dinucleotides nicotinamide-adenine-dinucleotide (NAD), nicotinic acid–adenine-dinucleotide (NAAD), and NAAD-2′-phosphate (NAADP) have been shown to activate TRPM2, or to enhance its activation by ADPR, when dialyzed into cells. The precise subset of nucleotides that act directly on the TRPM2 protein, however, is unknown. Here, we use a heterologously expressed, affinity-purified–specific ADPR hydrolase to purify commercial preparations of pyridine dinucleotides from substantial contaminations by ADPR or ADPR-2′-phosphate (ADPRP). Direct application of purified NAD, NAAD, or NAADP to the cytosolic face of TRPM2 channels in inside-out patches demonstrated that none of them stimulates gating, or affects channel activation by ADPR, indicating that none of these dinucleotides directly binds to TRPM2. Instead, our experiments identify for the first time ADPRP as a true direct TRPM2 agonist of potential biological interest. 相似文献
3.
Milka Elshishka Stela Lazarova Georgi Radoslavov Petar Hristov Vlada K. Peneva 《ZooKeys》2015,(511):25-68
The taxonomic position of two antarctic dorylaimid species Amblydorylaimus
isokaryon (Loof, 1975) Andrássy, 1998 and Pararhyssocolpus
paradoxus (Loof, 1975), gen. n., comb. n. are discussed on the basis of morphological, including SEM study, morphometric, postembryonic and sequence data of 18S rDNA and the D2-D3 expansion fragments of large subunit rDNA. The evolutionary trees inferred from 18S sequences show insufficient resolution to determine the assignment of the two species to particular families, moreover Pararhyssocolpus
paradoxus
gen. n., comb. n. (=Rhyssocolpus
paradoxus) previously regarded as a member of Nordiidae or Qudsianematidae, showed distant relationship both to Rhyssocolpus
vinciguerrae and Eudorylaimus spp. The phylogram inferred from 28S sequences revealed that Amblydorylaimus
isokaryon is a member of a well-supported group comprised of several Aporcelaimellus spp., while, no close relationships could be revealed for the Pararhyssocolpus
paradoxus
gen. n., comb. n. to any nematode genus. On the basis of molecular data and morphological characteristics, some taxonomic changes are proposed. Amblydorylaimus
isokaryon is transferred from family Qudsianematidae to family Aporcelaimidae, and a new monotypic genus Pararhyssocolpus
gen. n. is proposed, attributed to Pararhyssocolpidae
fam. n. The diagnosis of the new family is provided together with emended diagnosis of the genera Amblydorylaimus and Pararhyssocolpus
gen. n. Data concerning distribution of these endemic genera in the Antarctic region are also given. 相似文献
4.
Andrea Shafer Alexandru Iordan Roberto Cabeza Florin Dolcos 《Journal of visualized experiments : JoVE》2011,(51)
Emotional events tend to be better remembered than non-emotional events1,2. One goal of cognitive and affective neuroscientists is
to understand the neural mechanisms underlying this enhancing effect of emotion on memory. A method that has proven particularly influential in the
investigation of the memory-enhancing effect of emotion is the so-called subsequent memory paradigm (SMP). This method was originally used to investigate the
neural correlates of non-emotional memories3, and more recently we and others also applied it successfully to studies of emotional memory (reviewed in4, 5-7).
Here, we describe a protocol that allows investigation of the neural correlates of the memory-enhancing effect of emotion using the SMP in conjunction with
event-related functional magnetic resonance imaging (fMRI). An important feature of the SMP is that it allows separation of brain activity specifically
associated with memory from more general activity associated with perception. Moreover, in the context of investigating the impact of emotional stimuli,
SMP allows identification of brain regions whose activity is susceptible to emotional modulation of both general/perceptual and memory-specific processing.
This protocol can be used in healthy subjects8-15, as well as in clinical patients where there are alterations in the neural correlates of emotion perception
and biases in remembering emotional events, such as those suffering from depression and post-traumatic stress disorder (PTSD)16, 17. Download video file.(95M, mov) 相似文献
5.
Papantchev V Paloff A Hinova-Palova D Hristov S Todorova D Ovtscharoff W 《Journal of molecular histology》2006,37(8-9):343-352
Nitric oxide is a unique neurotransmitter, which participates in many physiological and pathological processes in the organism. Nevertheless, there are little data about the neuronal nitric oxide synthase immunoreactivity (nNOS-ir) in the vestibular complex of a cat. In this respect, the aims of this study were to: (1) demonstrate nNOS-ir in the neurons and fibers, from all major and accessory vestibular nuclei; (2) describe their light microscopic morphology and distribution; (3) investigate and analyze the ultrastructure of the NOS I-immunopositive neurons, fibers, and synaptic boutons. For demonstration of the nNOS-ir, the peroxidase–antiperoxidase–diaminobenzidin method was applied. Immunopositive for nNOS neurons and fibers were present in all major and accessory vestibular nuclei. On the light microscope level, the immunopositive neurons were different in shape and size. According to the latter, they were divided into four groups—small (with diameter less than 15 μm), medium-sized (with diameter from 15 to 30 μm), large type I (with diameter from 30 to 40 μm), and large type II (with diameter greater than 40 μm). On the electron microscope level, the immunoproduct was observed in neurons, dendrites, and terminal boutons. According to the ultrastructural features, the neurons were divided into three groups—small (with diameter less than 15 μm), medium-sized (with diameter from 15 to 30 μm), and large (with diameter greater than 30 μm). At least two types of nNOS-ir synaptic boutons were easily distinguished. As a conclusion, we hope that this study will contribute to a better understanding of the functioning of the vestibular complex in cat and that some of the data presented could be extrapolated to other mammals, including human. 相似文献
6.
Intracoronary infusion of autologous bone marrow cells and left ventricular function after acute myocardial infarction: a meta-analysis 总被引:3,自引:0,他引:3
Hristov M Heussen N Schober A Weber C 《Journal of cellular and molecular medicine》2006,10(3):727-733
Recent clinical studies have demonstrated that intracoronary infusion of autologous bone marrow cells (BMC) in conjunction with standard treatment may improve left ventricular function after an acute myocardial infarction (AMI). However, the results of these studies remain controversial, as the studies were relatively small in size and partially differed in design. We reviewed primary controlled randomized clinical studies comparing intracoronary transfer of autologous non-mobilized BMC combined with standard therapy versus standard therapy alone in patients with AMI. We identified five randomized controlled clinical trials, three of which were also placebo- and bone marrow aspiration-controlled. Non-mobilized BMC were infused into the revascularized coronary target artery 6.6 +/- 6.1 days after AMI. The mean follow- up period of 5.2 +/- 1.1 months was completed by 482 patients, 241 of which received infusion of BMC. The effect of BMC on left ventricular ejection fraction (LVEF) as a major functional parameter was evaluated. Analyzing the overall effect on the change in LVEF between baseline and follow-up value revealed a significant improvement in the BMCtreated group as compared to the control group (P = 0.04). Thus, considering the increase in LVEF during follow-up, transplantation of BMC may be a safe and beneficial procedure to support treatment of AMI. However, the functional improvement observed with this form of therapy was altogether relatively moderate and the studies were heterogeneous in design. Hence, further efforts aiming at large-scale, double-blind, randomized and placebo-controlled multi-center trials in conjunction with better definition of patients, which benefit from BMC infusion, appear to be warranted. 相似文献
7.
Hristov KL Chen M Soder RP Parajuli SP Cheng Q Kellett WF Petkov GV 《American journal of physiology. Cell physiology》2012,302(2):C360-C372
Voltage-gated K(+) (K(V)) channels are implicated in detrusor smooth muscle (DSM) function. However, little is known about the functional role of the heterotetrameric K(V) channels in DSM. In this report, we provide molecular, electrophysiological, and functional evidence for the presence of K(V)2.1 and electrically silent K(V) channel subunits in guinea pig DSM. Stromatoxin-1 (ScTx1), a selective inhibitor of the homotetrameric K(V)2.1, K(V)2.2, and K(V)4.2 as well as the heterotetrameric K(V)2.1/6.3 and K(V)2.1/9.3 channels, was used to examine the role of these K(V) channels in DSM function. RT-PCR indicated mRNA expression of K(V)2.1, K(V)6.2-6.3, K(V)8.2, and K(V)9.1-9.3 subunits in isolated DSM cells. K(V)2.1 protein expression was confirmed by Western blot and immunocytochemistry. Perforated whole cell patch-clamp experiments revealed that ScTx1 (100 nM) inhibited the amplitude of the K(V) current in freshly isolated DSM cells. ScTx1 (100 nM) did not significantly change the steady-state activation and inactivation curves for K(V) current. However, ScTx1 (100 nM) decreased the activation time-constant of the K(V) current at positive voltages. Although our patch-clamp data could not exclude the presence of the homotetrameric K(V)2.1 channels, the biophysical characteristics of the ScTx1-sensitive current were consistent with the presence of heterotetrameric K(V)2.1/silent K(V) channels. Current-clamp recordings showed that ScTx1 (100 nM) did not change the DSM cell resting membrane potential. ScTx1 (100 nM) increased the spontaneous phasic contraction amplitude, muscle force, and muscle tone as well as the amplitude of the electrical field stimulation-induced contractions of isolated DSM strips. Collectively, our data revealed that K(V)2.1-containing channels are important physiological regulators of guinea pig DSM excitability and contractility. 相似文献
8.
Hristov KL Chen M Afeli SA Cheng Q Rovner ES Petkov GV 《American journal of physiology. Cell physiology》2012,302(11):C1599-C1608
The functional role of the voltage-gated K(+) (K(V)) channels in human detrusor smooth muscle (DSM) is largely unexplored. Here, we provide molecular, electrophysiological, and functional evidence for the expression of K(V)2.1, K(V)2.2, and the electrically silent K(V)9.3 subunits in human DSM. Stromatoxin-1 (ScTx1), a selective inhibitor of K(V)2.1, K(V)2.2, and K(V)4.2 homotetrameric channels and of K(V)2.1/9.3 heterotetrameric channels, was used to examine the role of these channels in human DSM function. Human DSM tissues were obtained during open bladder surgeries from patients without a history of overactive bladder. Freshly isolated human DSM cells were studied using RT-PCR, immunocytochemistry, live-cell Ca(2+) imaging, and the perforated whole cell patch-clamp technique. Isometric DSM tension recordings of human DSM isolated strips were conducted using tissue baths. RT-PCR experiments showed mRNA expression of K(V)2.1, K(V)2.2, and K(V)9.3 (but not K(V)4.2) channel subunits in human isolated DSM cells. K(V)2.1 and K(V)2.2 protein expression was confirmed by Western blot analysis and immunocytochemistry. Perforated whole cell patch-clamp experiments revealed that ScTx1 (100 nM) inhibited the amplitude of the voltage step-induced K(V) current in freshly isolated human DSM cells. ScTx1 (100 nM) significantly increased the intracellular Ca(2+) level in DSM cells. In human DSM isolated strips, ScTx1 (100 nM) increased the spontaneous phasic contraction amplitude and muscle force, and enhanced the amplitude of the electrical field stimulation-induced contractions within the range of 3.5-30 Hz stimulation frequencies. These findings reveal that ScTx1-sensitive K(V)2-containing channels are key regulators of human DSM excitability and contractility and may represent new targets for pharmacological or genetic intervention for bladder dysfunction. 相似文献
9.
PURPOSE OF REVIEW: To discuss crucial cues (chemokines, adhesion molecules and pharmacological means) that guide and control the context-specific mobilization, recruitment and fate of circulating progenitor cells in arterial repair and plaque stability. RECENT FINDINGS: The mobilization and recruitment of bone marrow derived or resident progenitor cells giving rise to smooth muscle cells have been implicated in accelerated forms of primary plaque formation and neointimal hyperplasia after arterial injury. By contrast, convincing evidence has emerged that the arterial homing of endothelial progenitor cells contributes to endothelial recovery and thereby limits neointimal growth after endothelial denudation. In the chronic context of primary atherosclerosis, plaque progression and destabilization, a more complex picture has become apparent. Clinically, the number and function of endothelial progenitor cells have been linked with an improved endothelial function or regeneration and have been frequently inversely correlated with cardiovascular risk (factors). In animal models, however, the injection of bone marrow cells or endothelial progenitor cells, as well as the application of stem-cell mobilizing factors, have been associated with an exacerbation of atherosclerosis and unstable plaque phenotype, whereas the contribution of smooth muscle progenitors to primary atherosclerosis appears to be more confined to supporting plaque stability. SUMMARY: Considering the balance between distinct circulating vascular progenitor cells and identifying mechanisms for selective control of their mobilization and homing appears crucial to improve prediction and to directly modulate endogenous vascular remodeling processes. 相似文献
10.