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161.
Lysyl oxidase binds transforming growth factor-beta and regulates its signaling via amine oxidase activity 总被引:1,自引:0,他引:1
Atsawasuwan P Mochida Y Katafuchi M Kaku M Fong KS Csiszar K Yamauchi M 《The Journal of biological chemistry》2008,283(49):34229-34240
Lysyl oxidase (LOX), an amine oxidase critical for the initiation of collagen and elastin cross-linking, has recently been shown to regulate cellular activities possibly by modulating the functions of growth factors. In this study, we investigated the interaction between LOX and transforming growth factor-beta1 (TGF-beta1), a potent growth factor abundant in bone, the effect of LOX on TGF-beta1 signaling, and its potential mechanism. The specific binding between mature LOX and mature TGF-beta1 was demonstrated by immunoprecipitation and glutathione S-transferase pulldown assay in vitro. Both proteins were colocalized in the extracellular matrix in an osteoblastic cell culture system, and the binding complex was identified in the mineral-associated fraction of bone matrix. Furthermore, LOX suppressed TGF-beta1-induced Smad3 phosphorylation likely through its amine oxidase activity. The data indicate that LOX binds to mature TGF-beta1 and enzymatically regulates its signaling in bone and thus may play an important role in bone maintenance and remodeling. 相似文献
162.
Vajda S Bartha K Wilhelm I Krizbai IA Adam-Vizi V 《Neurochemistry international》2008,52(6):1234-1239
An improved method is described for culturing primary rat brain capillary endothelial cells (RBCEC) on glass, covered by Matrigel. The procedure using Matrigel yields spindle-shaped endothelial cells exhibiting close cell-cell appositions seen on electron microscopic sections. These cells permanently express tight junction proteins ZO-1, claudin-5 and the adherent junction protein beta-catenin, as revealed by immunofluorescence. Furthermore, glass coverslips covered with Matrigel provide a stable and low-background fluorescent base for microfluorimetric calcium measurements. By this method, hereby we show that the PAR-4 agonist peptide induces transient [Ca2+]i changes with different kinetics compared to that due to activation of the PAR-1 receptor. This indicates that RBCE cells grown on Matrigel express PAR-4 receptors. 相似文献
163.
Attila Fábián Katalin Jäger Éva Darkó Beáta Barnabás 《Acta Physiologiae Plantarum》2008,30(5):737-744
A procedure has been developed for the cryopreservation of wheat female gametes. The procedure involves loading the cells with 25% concentrated vitrification solution consisting of 30% glycerol, 10% sucrose, 120 mM ascorbic acid (AA) and 5% propylene glycol (PG), dehydration in 80% concentrated vitrification solution, droplet vitrification and storage in liquid nitrogen, unloading and rehydration of the cells by gradual addition of isolation solution. Supplementation with AA significantly increased the proportion of viable egg cells after de- and rehydration. During the early phase of rehydration AA reduced the probability of membrane damage caused by rapid water uptake. Maintaining the temperature of the cells at 0°C during the de- and rehydration processes increased cell survival. Microscopic examination of the semi-thin sections of untreated and viable cryopreserved cells revealed that the vitrification process might cause changes in cell structure. 相似文献
164.
Persistent elevation of the intracellular free Ca(2+) concentration [Ca(2+)](i) is neurotoxic and therefore it is important to understand how it affects downstream components of the Ca(2+) signaling pathway. The response of calmodulin (CaM) and alphaCa(2+)/CaM-dependent protein kinase II (alphaCaMKII), to intracellular Ca(2+) overload in hippocampal neurons is studied by confocal imaging of fluorescently tagged proteins. Transient and persistent redistribution of CaM and alphaCaMKII together is seen from the cytosol to dendritic and somatic punctae. Typical persistent redistribution occurs following a lag of 138+/-(S.E.M.) 12 s and is complete at 460+/-(S.E.M.) 34 s (n=18), lack of Thr(286)-autophosphorylation of alphaCaMKII however promotes the formation of early transient punctae (peak at 40 s). In contrast, the T286D-mimick of phospho-Thr(286)-alphaCaMKII forms punctae with a delay >10 min, indicating that Thr(286)-autophosphorylation is antagonistic to CaMKII clustering. A two-state model is proposed in which phospho-Thr(286)-alphaCaMKII, formed immediately upon Ca(2+) stimulation, is primarily responsible for target interactions and memory functions of alphaCaMKII. However, a distinct clustering form denoted alphaCaMKII(c), generated upon persistent intracellular free Ca(2+) elevation, is deposited in the punctae which are made of self-interacting CaM/CaMKII complexes. Punctate deposition disables both the interactions and the activity of CaMKII. 相似文献
165.
Di Natale G Damante CA Nagy Z Osz K Pappalardo G Rizzarelli E Sóvágó I 《Journal of inorganic biochemistry》2008,102(11):2012-2019
The solution conformation and the copper(II) binding properties have comparatively been investigated for the two novel hexapeptides Ac-HPSGHA-NH2 (P2) and Ac-HGSPHA-NH2 (P4). The study has been carried out by means of CD, NMR, EPR and UV-Vis spectroscopic techniques in addition to potentiometric measurements to determine the stability constants of the different copper(II) complex species formed in the pH range 3-11. The peptides contain two histidine residues as anchor sites for the metal ion and differ only for the exchanged position of the proline residue with glycine. CD and NMR results for the uncomplexed peptide ligands suggest a predominantly unstructured peptide chain in aqueous solution. Potentiometric and spectroscopic data (UV-Vis, CD and EPR) show that both peptides strongly interact with copper(II) ions by forming complexes with identical stoichiometries but different structures. Furthermore, Far-UV CD experiments indicate that the conformation of the peptides is dramatically affected following copper(II) complexation with the P4 peptide adopting a β-turn-like conformation. 相似文献
166.
167.
Doleviczényi Z Vizi ES Gacsályi I Pallagi K Volk B Hársing LG Halmos G Lendvai B Zelles T 《Neurochemical research》2008,33(11):2364-2372
In humans, serotonin (5-HT) has been implicated in numerous physiological and pathological processes in the peripheral auditory
system. Dopamine (DA), another transmitter of the lateral olivocochlear (LOC) efferents making synapses on cochlear nerve
dendrites, controls auditory nerve activation and protects the sensory nerve against overactivation. Using in vitro microvolume
superfusion techniques we tested 5-HT6 and 5-HT7 receptor antagonists whether they can influence dopamine (DA) release from the guinea-pig cochlea in control and in ischemic
conditions using currently available and new 5-HT6 and 5-HT7 antagonists and mixed antagonists, which were synthesized and characterized for the current study. While the 5-HT7 antagonist SB-258719 was ineffective, SB-271046, which blocks the 5-HT6 receptor, caused a significant increase in cochlear DA release what is contradictory with the excitatory nature of this type
of receptor. Moreover, the mixed 5-HT6/7 antagonist EGIS-12233 induced an even more pronounced increase in the resting DA release. To understand why the block of
an excitatory receptor results in an increase instead of a decrease in function, we investigated the possible involvement
of an indirect neural mechanism through an inhibitory system. In the presence of the GABAA receptor blocker bicuculline, EGIS-12233 failed to increase the release of DA, suggesting that the serotonin receptor modulation
of DA release from the lateral olivocochlear efferents in the cochlea was produced indirectly by decreasing the GABAergic
inhibitory tone on dopaminergic nerve endings. The mixed 5-HT7/D4 receptor antagonist EGIS-11983 significantly increased both the stimulation-evoked and the resting DA release, while the
selective D4 blocker L-741,741 alone had no significant effect. Ischemia, simulated by oxygen and glucose deprivation from
the perfusion solution had no action on the effect of the drugs. Drugs that can increase the release of DA from LOC terminals
in the cochlea may have a role in the treatment of sensorineural hearing loss. 相似文献
168.
Changes of organic matter quality along the longitudinal axis of a large shallow lake (Lake Balaton)
Hydrobiologia - Dissolved organic matter (DOM) is quantitatively the most significant pool of organic matter in lakes. Within DOM, the pool of dissolved organic carbon (DOC) is dominated... 相似文献
169.
Molnár Miklós Horváth Katalin Dankó Tamás Somlyai Ildikó Kovács Beáta Zs. Somlyai Gábor 《Molecular and cellular biochemistry》2021,476(12):4507-4516
Molecular and Cellular Biochemistry - Deuterium (D) is a stable isotope of hydrogen (H) with a mass number of 2. It is present in natural waters in the form of HDO, at a concentration of... 相似文献
170.