共查询到20条相似文献,搜索用时 31 毫秒
1.
Summary This investigation studied the effects of intrauterine injections of histamine dihydrochloride on blastocyst implantation in the laboratory rat. Results of this study lend support to the idea that histamine is the initiator of implantation through the induction of decidualization in this species. 相似文献
2.
The present work investigates the possibility that lipoxygenase products are involved in the biochemical mechanisms of blastocyst implantation by utilizing nordihydroguaiaretic acid (NDGA) and caffeic acid (CA), inhibitors of lipoxygenase enzymes, and quinacrine (QU), an inhibitor of phospholipase-A2. It has been shown previously that inhibition of cyclooxygenase results in blockade of implantation. The inhibitors were dissolved in a standard medium and 5 microliter of the solutions were micro-injected into the uterine horns of day-4 pregnant mice. The contralateral horns acted as controls and received only vehicle. A sham-operated group provided normal controls. In 14 NDGA-treated mice, the control horns contained 40 implantations while the treated horns contained only 6 small implantations and 8 resorbing sites. These control horns were comparable to the sham controls. In 14 CA-treated mice, treated horns contained 17 small implantations plus 4 resorptions, whereas the control horns contained 26 small implantations and 4 resorptions. Twelve QU-treated mice exhibited 7 small implantations and 4 resorptions in the treated horns, plus 24 small sites and no resorptions in the control horns. Fourteen sham-operated mice had 95 implantation sites and no resorptions in their 28 horns. The results provide evidence for the involvement of the lipoxygenase enzymes and phospholipase-A2 in the initial implantation process and in the subsequent development of early pregnancy. 相似文献
3.
Summary The present work investigates the possibility that lipoxygenase products are involved in the biochemical mechanisms of blastocyst implantation by utilizing nordihydroguaiaretic acid (NDGA) and caffeic acid (CA), inhibitors of lipoxygenase enzymes, and quinacrine (QU), an inhibitor of phospholipase-A2. It has been shown previously that inhibition of cyclooxygenase results in blockade of implantation. The inhibitors were dissolved in a standard medium and 5 l of the solutions were micro-injected into the uterine horns of day-4 pregnant mice. The contralateral horns acted as controls and received only vehicle. A sham-operated group provided normal controls. In 14 NDGA-treated mice, the control horns contained 40 implantations while the treated horns contained only 6 small implantations and 8 resorbing sites. These control horns were comparable to the sham controls. In 14 CA-treated mice, treated horns contained 17 small implantations plus 4 resorptions, whereas the control horns contained 26 small implantations and 4 resorptions. Twelve QU-treated mice exhibited 7 small implantations and 4 resorptions in the treated horns, plus 24 small sites and no resorptions in the control horns. Fourteen sham-operated mice had 95 implantation sites and no resorptions in their 28 horns. The results provide evidence for the involvement of the lipoxygenase enzymes and phospholipase-A2 in the initial implantation process and in the subsequent development of early pregnancy. 相似文献
4.
P J Chan 《Experientia》1987,43(8):929-930
The in vitro development and attachment of hatched mouse blastocysts on the untreated substratum was enhanced by 10 microM dibutyryl cCMP (dbcCMP). The result suggests that cCMP has an effect on embryonic development and on the blastocyst attachment process. 相似文献
5.
P. J. Chan 《Cellular and molecular life sciences : CMLS》1987,43(8):929-930
Summary The in vitro development and attachment of hatched mouse blastocysts on the untreated substratum was enhanced by 10 M dibutyryl cCMP (dbcCMP). The result suggests that cCMP has an effect on embryonic development and on the blastocyst attachment process.25 November1986 相似文献
6.
Christiana Ruhrberg Victoria L. Bautch 《Cellular and molecular life sciences : CMLS》2013,70(10):1675-1684
The developing central nervous system (CNS) is vascularized via ingression of blood vessels from the outside as the neural tissue expands. This angiogenic process occurs without perturbing CNS architecture due to exquisite cross-talk between the neural compartment and invading blood vessels. Subsequently, this intimate relationship also promotes the formation of the neurovascular unit that underlies the blood–brain barrier and regulates blood flow to match brain activity. This review provides a historical perspective on research into CNS blood vessel growth and patterning, discusses current models used to study CNS angiogenesis, and provides an overview of the cellular and molecular mechanisms that promote blood vessel growth and maturation. Finally, we highlight the significance of these mechanisms for two different types of neurovascular CNS disease. 相似文献
7.
Salminen A Ojala J Huuskonen J Kauppinen A Suuronen T Kaarniranta K 《Cellular and molecular life sciences : CMLS》2008,65(7-8):1049-1058
Research on aging in model organisms has revealed different molecular mechanisms involved in the regulation of the lifespan.
Studies on Saccharomyces cerevisiae have highlighted the role of the Sir2 family of genes, human Sirtuin homologs, as the longevity factors. In Caenorhabditis elegans, the daf-16 gene, a mammalian homolog of FoxO genes, was shown to function as a longevity gene. A wide array of studies has
provided evidence for a role of the activation of innate immunity during aging process in mammals. This process has been called
inflamm-aging. The master regulator of innate immunity is the NF-κB system. In this review, we focus on the several interactions
of aging-associated signaling cascades regulated either by Sirtuins and FoxOs or NF-κB signaling pathways. We provide evidence
that signaling via the longevity factors of FoxOs and SIRT1 can inhibit NF-κB signaling and simultaneously protect against inflamm-aging process.
Received 4 October 2007; received after revision 7 November 2007; accepted 9 November 2007 相似文献
8.
Ion channels in plant signaling 总被引:5,自引:0,他引:5
S. Zimmermann T. Ehrhardt G. Plesch B. Müller-Röber 《Cellular and molecular life sciences : CMLS》1999,55(2):183-203
Plant ion channel activities are rapidly modulated in response to several environmental and endogenous stimuli such as light,
pathogen attack and phytohormones. Electrophysiological as well as pharmacological studies provide strong evidence that ion
channels are essential for the induction of specific cellular responses, implicating their tight linkage to signal transduction
cascades. Ion channels propagate signals by modulating the membrane potential or by directly affecting cellular ion composition.
In addition, they may also be effectors at the end of signaling cascades, as examplified by ion channels which determine the
solute content of stomatal guard cells. Plant channels are themselves subject to regulation by a variety of cellular factors,
including calcium, pH and cyclic nucleotides. In addition, they appear to be regulated by (de)-phosphorylation events as well
as by direct interactions with cytoskeletal and other cellular proteins. This review summarizes current knowledge on the role
of ion chan nels in plant signaling. 相似文献
9.
C Babinet R Kemler P Dubois F Jacob 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1977,284(19):1919-1922
Fab fragments of a Rabbit anti-F 9 serum do not disturb cleavage of Mouse embryos in culture but prevent blastocyst formation. This effect is reversible for a few hours. It is observed neither with Fab fragments directed against another surface antigen of blastomers nor with monovalent concanavalin A. 相似文献
10.
Natalia Arenas-Ramirez Dilara Sahin Onur Boyman 《Cellular and molecular life sciences : CMLS》2018,75(22):4163-4176
The recent impact of cancer immunotherapies has firmly established the ability and importance of the immune system to fight malignancies. However, the intimate interaction between the highly dynamic tumor and immune cells leads to a selection process driven by genetic and epigenetic processes. As the molecular pathways of cancer resistance mechanisms to immunotherapy become increasingly known, novel therapeutic targets are being tested in combination with immune-stimulating approaches. We here review recent insights into the molecular mechanisms of tumor resistance with particular emphasis on epigenetic processes and place these in the context of previous models. 相似文献
11.
Trimeric guanine nucleotide-binding proteins (G proteins) function as the key regulatory elements in a number of transmembrane
signaling cascades where they convey information from agonist-activated receptors to effector molecules. The subcellular localization
of G proteins is directly related to their functional role, i.e., the dominant portion of the cellular pool of G proteins
resides in the plasma membrane. An intimate association of G protein subunits with the plasma membrane has been well known
for a long time. However, results of a number of independent studies published in the past decade have indicated clearly that
exposure of intact target cells to agonists results in subcellular redistribution of the cognate G proteins from plasma membranes
to the light-vesicular membrane fractions, in internalization from the cell surface into the cell interior and in transfer
from the membrane to the soluble cell fraction (high-speed supernatant), i.e., solubilization. Solubilization of G protein
α subunits as a consequence of stimulation of G protein-coupled receptors (GPCRs) with agonists has also been observed in
isolated membrane preparations. The membrane-cytosol shift of G proteins was detected even after direct activation of these
proteins by non-hydrolyzable analogues of GTP or by cholera toxin-induced ADP-ribosylation. In addition, prolonged stimulation
of GPCRs with agonists has been shown to lead to down-regulation of the relevant G proteins. Together, these data suggest
that G proteins might potentially participate in a highly complex set of events, which are generally termed desensitization
of the hormone response. Internalization, subcellular redistribution, solubilization, and down-regulation of trimeric G proteins
may thus provide an additional means (i.e., beside receptor-based mechanisms) to dampen the hormone or neurotransmitter response
after sustained (long-term) exposure.
Received 31 August 2001; received after revision 31 October 2001; accepted 7 November 2001 相似文献
12.
Basañez G 《Cellular and molecular life sciences : CMLS》2002,59(9):1478-1490
Membrane fusion constitutes a pivotal process in eukaryotic cell physiology. Both specialized proteins and membrane lipids
play key roles in fusion. Here, our current understanding of the mechanism of membrane fusion is reviewed. The focus is on
the relatively simple and well-understood proteinaceous fusion machinery of enveloped viruses and the physical properties
of lipids that appear to be of great relevance for fusion progression. Recent observations suggest that viral fusion proteins
use packed conformational energy and bilayer-destabilizing domains to (i) bring participating membranes into intimate contact,
(ii) merge proximal lipid monolayers through highly curved stalk/hemifusion intermediates, and (iii) generate a lipid-containing
fusion pore, thereby terminating the fusion process.
Received 4 January 2002; received after revision 3 April 2002; accepted 5 April 2002 相似文献
13.
Regulatory mechanisms of mitogen-activated kinase signaling 总被引:5,自引:1,他引:4
MAP kinases (MAPKs) are evolutionarily conserved regulators that mediate signal transduction and play essential roles in various
physiological processes. There are three main families of MAPKs in mammals, whose functions are regulated by activators, inactivators,
substrates and scaffolds, which together form delicate signaling cascades in response to different extracellular or intracellular
stimulation. MAPK signaling is tightly regulated so that optimal biological activities are achieved and health is maintained.
However, how the specificity of the signaling flow along each cascade is achieved is still relatively unclear. In this review,
we summarize recent advances in understanding the regulation of MAPK cascades and the roles of MAP kinases and their regulators
in development and in immune responses.
Received 11 January 2007; received after revision 31 May 2007; accepted 5 July 2007 相似文献
14.
Karen Thulasi Devendrakumar Xin Li Yuelin Zhang 《Cellular and molecular life sciences : CMLS》2018,75(16):2981-2989
In plants, mitogen-activated protein kinase (MAPK) cascades are involved in regulating many biological processes including immunity. They relay signals from membrane-residing immune receptors to downstream components for defense activation. Arabidopsis MPK3/6 and MPK4 are activated in two parallel MAPK cascades during PAMP-triggered immunity. MPK3/6 have been implicated in the activation of various immune responses and their inactivation leads to compromised defense against pathogens. On the other hand, the MEKK1-MKK1/2-MPK4 cascade plays critical roles in basal resistance. Disruption of this MAPK cascade results in constitutive defense responses mediated by the NB-LRR protein SUMM2. Interestingly, SUMM2 guards the MEKK1-MKK1/2-MPK4 cascade activity indirectly through monitoring the phosphorylation status of CRCK3, which is a substrate of MPK4. From the pathogens’ side, a number of effectors are shown to target various components of MAPK cascades in plants. Inactivation of MPK4 by the Pseudomonas effector HopAI1 triggers SUMM2-mediated immunity. Together, these findings suggest intricate interplays between PAMP-triggered immunity and effector-triggered immunity via MAPK signaling. 相似文献
15.
Saori Takahashi Shin Kobayashi Ichiro Hiratani 《Cellular and molecular life sciences : CMLS》2018,75(7):1191-1203
It has been 8 years since the concept of naïve and primed pluripotent stem cell states was first proposed. Both are states of pluripotency, but exhibit slightly different properties. The naïve state represents the cellular state of the preimplantation mouse blastocyst inner cell mass, while the primed state is representative of the post-implantation epiblast cells. These two cell types exhibit clearly distinct developmental potential, as evidenced by the fact that naïve cells are able to contribute to blastocyst chimeras, while primed cells cannot. However, the epigenetic differences that underlie the distinct developmental potential of these cell types remain unclear, which is rather surprising given the large amount of active investigation over the years. Elucidating such epigenetic differences should lead to a better understanding of the fundamental properties of these states of pluripotency and the means by which the naïve-to-primed transition occurs, which may provide insights into the essence of stem cell commitment. 相似文献
16.
Neutrophils and macrophages are phagocytic cells that cooperate during inflammation and tissue repair. Neutrophils undergo
apoptosis and are engulfed by macrophages. Engulfment modulates macrophage activation and microbicidal activity. Infection
by Leishmania takes place in the context of tissue repair. This article discusses cellular and molecular mechanisms involved in the intimate
cooperation of neutrophils and macrophages in Leishmania infection. 相似文献
17.
Nakamura T Mito T Bando T Ohuchi H Noji S 《Cellular and molecular life sciences : CMLS》2008,65(1):64-72
Nymphs of hemimetabolous insects such as cockroaches and crickets exhibit a remarkable capacity for regenerating complex structures from damaged legs. Until recent years, however, approaches to elucidate the molecular mechanisms underlying the leg regeneration process have been lacking. Taking the cricket Gryllus bimaculatus as a model, we found that a phenotype related to regeneration frequently appears during leg regeneration, even though no phenotype is induced by RNA interference (RNAi) in the cricket nymph, designated as regeneration-dependent RNAi. Since then, we have investigated the functions of various genes encoding signaling factors and cellular adhesion proteins like Fat and Dachsous during leg regeneration. In this review, we summarize the classical knowledge about insect leg regeneration and introduce recent advances concerning the signaling cascades required for regenerating a leg. Our results provide clues to the mechanisms of regeneration which are relevant to vertebrate systems. 相似文献
18.
H Alexandre 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1978,286(16):1215-1217
Alpha-Methylornithine, an inhibitor of the synthesis of putrescine does not affect the cleavage of Mouse eggs, cultured in vitro from the 2-cell stage, before blastocyst formation, whereas methylglyoxal-Bis (guanylhydrazone), an inhibitor of the syntheses of spermidine and spermine induces the embryos to become quiescent at about the 8-cell stage; resumption of their development, after transfer to fresh medium, is followed by a delay in cavitation. These results may be related to the biological clock theory for primary differentiation. 相似文献
19.
Summary When a serumless medium is used for the in vitro growth and development of post-blastocyst mouse embryos, a collagen substratum causes a delay in the hatching from the zona pellucida. However, the collagen substratum is essential for blastocyst attachment and trophoblast cell outgrowth after hatching has taken place. 相似文献
20.
Summary The dibutyryl analog of cCMP enlarged the nuclei of trophoblast gian cells and promoted blastocyst development. The result suggests that cCMP has a trophic effect on embryonic development, specifically by altering the size of the trophoblast cell nucleus but does not enhance trophoblast cell proliferation processes. 相似文献