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1.
Occupational exposure and experimental intoxication with acrylamide (ACR) produce neuropathy characterized by nerve degeneration. To investigate the mechanism of ACR-induced neuropathy, male adult Wistar rats were given ACR (20, 40 mg/kg i.p. 3 days/week) for 8 weeks. Sciatic nerves were Triton-extracted and centrifuged at a high speed (100,000 × g) to yield pellet and supernatant fractions. The contents of six cytoskeletal proteins (NF-L, NF-M, NF-H, α-tubulin, β-tubulin, and β-actin) in both fractions were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. Results showed that the three neurofilament (NF) subunits (NF-L, NF-M, NF-H) in both the pellet and the supernatant fraction decreased significantly (P < 0.01) in the high-dosing group, except for NF-M in the pellet. α-tubulin, β-tubulin, and β-actin increased significantly in the supernatant (P < 0.01), whereas both α-tubulin and β-tubulin decreased significantly in the pellet (P < 0.01). However, β-actin was not altered significantly in the sciatic nerves pellet. These findings suggest that ACR altered the cytoskeletal protein level in sciatic nerve, which may be one of the molecular mechanisms of ACR-induced peripheral neuropathy. 相似文献
2.
Acrylamide (ACR) is a known industrial neurotoxic chemical that can induce neurodegeneration. Cytoskeletal protein aggregation is a pathological hallmark of neurodegenerative disorders. This study was an initial exploration on cytoskeletal proteins in plasma as potential biomarkers of ACR neurotoxicity. Low and high ACR groups received 20 mg/kg and 40 mg/kg ACR by intraperitoneal injection in adult Wistar rats and control group received physiological saline. Rats were all killed after 8 weeks to evaluate the levels of neurofilament(NF)-L, NF-M, NF-H, β-actin, α-tubulin, β-tubulin, tau, MAP2 proteins in plasma using both SDS-PAGE and western blotting. Compared with the control, the levels of NF-L, NF-M, NF-H, β-actin, tau, MAP2 proteins decreased and the level of α-tubulin increased in high ACR group, the levels of α-tubulin, β-tubulin and MAP2 increased in low ACR group. The results suggested that the changes of these proteins might be relevant to the neurotoxicity of ACR. Some of the cytoskeletal proteins in plasma might be used as marker of biological effect in ACR induced neuropathy. 相似文献
3.
The immediate early response gene IEX-1 is involved in the regulation of apoptosis and cell growth. In order to increase the apoptotic sensitivity to chemotherapeutic drugs and gamma-ray, we attempted to establish U87-MG human glioma cell line expressing IEX-1. Unexpectedly, however, transfection of IEX-1 into U87-MG glioma cells resulted in morphological changes to astrocytic phenotype and increase in glial differentiation marker proteins, S-100 and glial fibrillary acidic protein (GFAP). Glial cell differentiation was used to examine in rat C6 glioma cell line, since this cell line express astrocytic phenotypes by increase in intracellular cAMP concentration. Stimulation of human U87-MG glioma cells by membrane-permeable dibutyryl cAMP (dbcAMP) not only elicited their morphological changes but also induced expression of IEX-1 as well as S-100 and GFAP. H89, an inhibitor of protein kinase A (PKA), blocked dbcAMP-induced morphological changes of U87-MG cells and expression of IEX-1. In contrast, morphological changes and expression of S-100 and GFAP induced by IEX-1 were not affected by H89. Morphological changes induced by dbcAMP were totally abolished by functional disruption of IEX-1 expression by anti-sense RNA. These results indicate that IEX-1 plays an important role in astrocytic differentiation of human glioma cells and that IEX-1 functions at downstream of PKA. 相似文献
4.
To investigate the mechanisms of the axonopathy induced by 2,5-hexanedione (2,5-HD), male Wistar rats were administered at
a dosage of 400 mg/kg/day 2,5-HD (five times per week). The rats produced a slightly, moderately, or severely abnormal neurological
changes, respectively, after 2, 4, or 8 weeks of treatment. The cerebrums were Triton-extracted and ultracentrifuged to yield
a pellet fraction and a corresponding supernatant fraction. The relative levels of six cytoskeletal proteins (NF-L, NF-M,
NF-H, α-tubulin, β-tubulin, and β-actin) in both fractions were determined by immunoblotting. The results showed that NFs
content in HD-treated rats demonstrated a progressive decline as the intoxication of HD continued. As for microtubule proteins,
the levels of α-tubulin and β-tubulin demonstrated some inconsistent changes. The content of α-tubulin kept unchangeable,
while the content of β-tubulin increased significantly at the late stage of HD exposure. Furthermore, the content of β-actin
in both fractions remained unaffected throughout the study. These findings suggest that HD intoxication resulted in a progressive
decline of NFs, which was highly correlated with the development of HD-induced neuropathy. 相似文献
5.
The role of 3′,5′-cyclic adenosine monophosphate (cAMP), protein kinase A (PKA), protein kinase C (PKC) and phosphatases
in the regulation of the taurine influx via the β-system in Ehrlich ascites tumor cells has been investigated. The taurine
uptake by the β-system in Ehrlich cells is inhibited when PKC is activated by phorbol 12-myristate 13-acetate (PMA) and when
protein phosphatases are inhibited by calyculin A (CLA). On the other hand, taurine uptake by the β-system is stimulated by
an increased level of cAMP or following addition of N6,2′-O-dibutyryl-3′,5′-cyclic adenosine monophosphate (dbcAMP). The effect of dbcAMP is partially blocked by addition of the
protein kinase inhibitor H-89, and suppressed in the presence of CLA. It is proposed that the β-system in the Ehrlich cells
exists in three states of activity: State I, where a PKC phosphorylation site on the transporter or on a regulator is phosphorylated and transport activity is low. State II, where the PKC phosphorylation site is dephosphorylated and transport activity is normal. State III, representing a state with high transport activity, induced by an elevated cellular cAMP level. Apparently, cAMP preferentially
stimulates taurine transport when the β-system is in State II.
Received: 8 September/Revised: 9 November 1995 相似文献
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Glial fibrillary acidic protein (GFA) expression was induced in rat C6 glioma in chemically defined medium by the addition of N6, O2'-dibutyryl cyclic AMP (dbcAMP). Induction was dependent on the increase in intracellular cyclic AMP (cAMP), which was linearly correlated with added dbcAMP. Contrary to GFA mRNA synthesis, which can be obtained by cAMP-dependent and -independent pathways, translation of mRNA into GFA was observed only above a cellular cAMP concentration of approximately 0.2 fmol/cell. dbcAMP stimulation did not affect the vimentin concentration, which remained at a low level, but changed the cellular morphology from a bipolar to a stellate shape. A similar morphological change was observed after stimulation of C6 with lipopolysaccharide (LPS). However, LPS did not significantly increase the intracellular concentration of cAMP and the LPS-induced mRNA was not translated into GFA. Our results indicate that GFA synthesis is regulated at the mRNA level and at the translational level and that a cAMP-dependent mechanism determines the ultimate synthesis of GFA by a yet unknown mechanism. 相似文献
9.
A Colcemid-resistant Chinese hamster line with an altered form of β-tubulin was used in studies of the expression of spindle
proteins in interspecific cell hybrids. Eight hybrids between this line, and a Colcemid-sensitive mouse cell line, were studied.
The altered hamster β-tubulin was not expressed as an increased resistance to Colcemid in any hybrid. Since the complete hamster
chromosome complement was represented among the hybrids, the absence of altered β-tubulin is not due to segregation of the
mutant hamster β-tubulin gene. We suggest either that the hamster β-tubulin gene is repressed in hybrids, or that hamster
β-tubulin is excluded from the spindle in hybrid cells. We compare these findings with previous reports of the repression
of other highly active, moderately repeated constitutive genes in interspecific hybrids. 相似文献
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To investigate the mechanism of carbon disulfide-induced neuropathy, male wistar rats were administrated by gavage at dosage
of 300 or 500 mg/kg carbon disulfide, five times per week for 12 weeks. By the end of the exposure, the animals produced a
slight or moderate level of neurological deficits, respectively. Cerebrums of carbon disulfide-intoxicated rats and their
age-matched controls were Triton-extracted and centrifuged at a high speed (100,000 × g) to yield a pellet fraction of NF polymer and a corresponding supernatant fraction, which presumably contained mobile monomer.
Then, the contents of six cytoskeletal protein (NF-L, NF-M, NF-H, α-tubulin, β-tubulin, and β-actin) in both fractions were
determined by immunoblotting. Results showed that the contents of the three neurofilament subunits in the pellet and the supernatant
fraction decreased significantly regardless of dose levels (P < 0.01). As for microtubule proteins, in the pellet fraction of cerebrum, the levels of α-tubulin and β-tubulin demonstrated
some inconsistent changes. However, in the supernatant fractions, the content of α-tubulin and β-tubulin increased significantly
in both two dose groups (P < 0.01). In comparison to neurofilament and tubulin proteins, the content of β-actin changed less markedly, only the supernatant
fraction of the high dose group displayed significant increase (P < 0.01), but the others remained unaffected. These findings suggested that the changes of cytoskeleton protein contents in
rat cerebrum were associated with the intoxication of carbon disulfide, which might be involved in the development of carbon
disulfide neurotoxicity. 相似文献
13.
Synthesis and assembly of ribosomal proteins into mature ribosomes persist late after infection of cells with herpes simplex
virus type 1, while synthesis of β-actin is drastically shut off. Since mRNAs encoding ribosomal proteins and β-actin undergo
concomitant degradation in infected HeLa cells, we have advanced the hypothesis that translation of the remaining mRNAs is
differentially controlled after infection. The behaviour of mRNAs for three ribosomal proteins and for β-actin was investigated
during the course of infection. In uninfected cells, β-actin mRNAs are associated with large polyribosomes, while only a part
of ribosomal protein mRNAs are present in polyribosomes. In the course of infection, β-actin mRNAs are released from the ribosomes
and are sequestered with 40S ribosomal subunits. Simultaneously, ribosomal protein mRNAs become associated with an increased
number of ribosomes, even late in infection. In addition, virally induced phosphorylation of ribosomal protein S6 is more
efficient in pre-existing ribosomes than in newly assembled ribosomes. These results indicate that in infected cells (i) translation
of β-actin mRNA is selectively inhibited at a step necessary for binding the 60S ribosomal subunits; (ii) the rate of initiation
of translation of ribosomal protein mRNAs increases after infection; and (iii) it is likely that translation of ribosomal
protein mRNAs takes place preferentially on pre-existing ribosomes.
Received: 5 February 1997 / Accepted: 28 May 1997 相似文献
14.
Yoo S Lee YG Kim JH Byeon SE Rho HS Cho JY Hong S 《Zeitschrift für Naturforschung. C, Journal of biosciences》2012,67(3-4):222-232
Histone acetylation is linked to the control of chromatin remodeling, which is involved in cell growth, proliferation, and differentiation. It is not fully understood whether cyclic adenosine monophosphate (cAMP), a representative differentiation-inducing molecule, is able to modulate histone acetylation as part of its anticancer activity. In the present study, we aimed to address this issue using cell-permeable cAMP, i.e. dibutyryl cAMP (dbcAMP) and C6 glioma cells. As reported previously, under the conditions of our studies, treatment with dbcAMP clearly arrested C6 cell proliferation and altered their morphology. Its antiproliferative and differentiation-inducing activity in C6 glioma cells involved upregulation of p219WAF/CIP), p27(kip1), glial fibrillary acidic protein (GFAP), and Cx43, as well as downregulation of vimentin. Furthermore, dbcAMP modulated the phosphorylation of ERK and Akt in a time-dependent manner and altered the colocalization pattern of phospho-Src and the actin cytoskeleton. Interestingly, dbcAMP upregulated the enzyme activity of histone acetyltransferase (HAT) and, in parallel, enhanced cellular acetyllysine levels. Finally, the hyperacetylation-inducing compound, sodium butyrate (NaB), a histone deacetylase (HDAC) inhibitor, displayed similar anticancer activity to dbcAMP. Therefore, our data suggest that antiproliferative and differentiation-inducing activities of dbcAMP may be generated by its enhanced hyperacetylation function. 相似文献
15.
Fibroblast spreading induced by connective tissue stretch involves intracellular redistribution of α- and β-actin 总被引:3,自引:3,他引:0
Langevin HM Storch KN Cipolla MJ White SL Buttolph TR Taatjes DJ 《Histochemistry and cell biology》2006,125(5):487-495
Mechanical stretching of connective tissue occurs with normal movement and postural changes, as well as treatments including physical therapy, massage and acupuncture. Connective tissue fibroblasts were recently shown to respond actively to short-term mechanical stretch (minutes to hours) with reversible cytoskeletal remodeling, characterized by extensive cell spreading and lamellipodia formation. In this study, we have examined the effect of tissue stretch on the distribution of α- and β-actin in subcutaneous tissue fibroblasts ex vivo. Normal fibroblasts uniformly exhibited α-smooth muscle actin (α-SMA) immunoreactivity. Unlike cultured fibroblasts and smooth muscle cells, α-SMA in these fibroblasts was not in F-actin form (indicated by lack of phalloidin co-localization) nor was it organized into distinct stress fibers. The lack of stress fibers and fibronexus was confirmed by electron microscopy, indicating that these cells were not myofibroblasts. In unstretched tissue, the pattern of α-actin was diffuse and granular. With tissue stretch (30 min), α-actin formed a star-shaped pattern centered on the nucleus, while β-actin extended throughout the cytoplasm including lamellipodia and cell cortex. This dual response pattern of α- and β-actin may be an important component of cellular mechanotransduction mechanisms relevant to physiologic and therapeutic mechanical forces applied to connective tissue. 相似文献
16.
E. Salas-Leiton B. Cánovas-Conesa R. Zerolo J. López-Barea J. P. Cañavate J. Alhama 《Marine biotechnology (New York, N.Y.)》2009,11(4):548-549
Solea senegalensis is a commercial flat fish traditionally farmed in earth ponds in coastal wetlands that might also become important to more
intensive aquaculture. Gas bubble disease (GBD) is a potential risk for outdoor fish farming, particularly in certain periods
of the year, related to improper management leading to macroalgae blooms. Physical-chemical conditions inducing hyperoxia,
including radiation, temperature, and high levels of dissolved oxygen, have been monitored in fish affected by GBD together
with observed symptoms. Exophthalmia, subcutaneous emphysemas, obstruction of gill lamellae, hemorrhages, and anomalous swimming
were the main effects of oxygen supersaturation. A proteomic study was carried out for the first time under aquaculture conditions
and protein expression changes are described for fish that were subject to hyperoxic conditions. Proteins identified in gill
of GBD-affected fish are related to oxidative alteration of cytoskeleton structure/function (β-tubulin, β-actin), motility
(light myosin chain, α-tropomyosin), or regulatory pathways (calmodulin, Raf kinase inhibitor protein), reflecting the central
role of gill in oxygen exchange. Hepatic proteins identified are related to protein oxidative damages (β-globin, FABPs), protection
from oxidative stress (DCXR, GNMT), and inflammatory response (C3), in agreement with the predominant metabolic role of liver.
Comparison of protein expression patterns and protein identification are suggested as potentially specific hyperoxia biomarkers
that would facilitate prevention of GBD outbreaks.
E. Salas-Leiton and B. Cánovas-Conesa had similar contributions to the work and should be considered as first authors
An erratum to this article can be found at 相似文献
17.
Julia Hirschfeld Julia Maurer Diana Jung Monika Kwiecinski Al Karim Khimji Hans Peter Dienes Jochen W. U. Fries Margarete Odenthal 《Molecular biotechnology》2009,43(2):121-129
Myofibroblasts are the main cell types producing extracellular matrix proteins in a variety of fibrotic diseases. Therefore,
they are useful targets for studies of intracellular communication and gene therapeutical approaches in scarring diseases.
An artificial promoter containing the −702 bp regulatory sequence of the α-smooth muscle actin (SMA) gene linked to the first
intron enhancer sequence of the β-actin gene and the β-globin intron-exon junction was constructed and tested for myofibroblast-dependent
gene expression using the green fluorescent protein as a reporter. Reporter expression revealed myofibroblast-specific function
in hepatic and renal myofibroblasts, in vitro. In addition, differentiation-dependent activation of the SMA-β-actin promoter
hybrid was shown after induction of myofibroblastic features in mesangial cells by stretching treatment. Furthermore, wound
healing experiments with SMA-β-actin promoter reporter mice demonstrated myofibroblast-specific action, in vivo. In conclusion,
the −702 bp regulatory region of the SMA promoter linked to enhancing β-actin and β-globin sequences benefits from its small
size and is suggested as a promising tool to target myofibroblasts as the crucial cell type in various scarring processes. 相似文献
18.
Sodium butyrate (NaB), when added to cell cultures, produces a variety of morphological and biochemical changes. We examined its effects, in nM concentrations, on the expression of two glioma cell-associated proteins, glial fibrillary acidic protein (GFAP) and S-100 protein in human glioma-derived cell line (RF), and of S-100 protein in the C6 rat glioma cell line. GFAP levels decreased by about 50% in the RF cell line, and S-100 protein levels decreased protein levels decreased by about 40% after treatment with 1 mM NaB for 48 h. In the C6 rat glioma cell line, isoproterenol with theophylline was found to increase S-100 levels by two-fold over basal levels. NaB was found to inhibit the induction of S-100 protein but exhibited no effect on the basal levels of the protein. Other short chain fatty acids, including sodium propionate and sodium isobutyrate, exhibited partial inhibitory activity. NaB, at an EC50 of 1 mM, was also found to inhibit both the beta-adrenergic and the forskolin-mediated increase in cAMP levels in these cells. This suggests that NaB may inhibit cells from expressing S-100 protein by attenuating cAMP levels. 相似文献
19.
Incoronata Galasso Antonella Manca Luca Braglia Tommaso Martinelli Laura Morello Diego Breviario 《Molecular breeding : new strategies in plant improvement》2011,28(4):635-645
We have developed a new version of the cTBP (combinatorial tubulin-based polymorphism) method, a previously described approach
based on intron-length polymorphism (ILP), to rapidly characterize the β-tubulin gene family of Camelina sativa (L.) Crantz, a plant species of importance for oil production but still largely unexplored at genomic level. The method,
named h-TBP, allows the rapid cloning of the β-tubulin genomic sequences that encompass the two introns, invariantly present
at fixed positions within the coding region of the vast majority of the plant species. The β-tubulin sequences cloned by h-TBP
also comprise part of exon1 and exon3 and the whole sequence of exon2. The h-TBP method has then been used to isolate, clone
and characterize the β-tubulin gene family of C. sativa, composed of at least 20 different β-tubulin isotypes, named CsTUB1 through CsTUB20. The relatively high number of β-tubulin genes has been further substantiated by Southern-blot analysis. Comparison of
the β-tubulin exon sequences of C. sativa with those of Arabidopsis thaliana, the closest relative among crucifers, defines distinct groups of putative orthologous genes, identified by a UPMGA cluster
analysis. Analysis of the C. sativa β-tubulin intron sequences reveals some molecular features that can provide the first hints for the understanding of intron
plasticity and evolution. From a more immediate perspective, these data provide the first substantial contribution to the
characterization of the largely unexplored genome of C. sativa, and the tools for assisting programmes of breeding and selection of the most productive plants. 相似文献
20.
Sántha P Pákáski M Fazekas OC Fodor EK Kálmán S Kálmán J Janka Z Szabó G Kálmán J 《Neurochemical research》2012,37(5):958-964
Stress is a relatively new and emerging risk factor for Alzheimer’s disease (AD). Severe stress can alter brain characteristics
such as neuronal plasticity, due to changes in the metabolism of cytoskeletal proteins. In this study, male Wistar rats were
exposed to restraint stress (RS) for 5 h daily for different time periods. At the end of the exposure periods, the amounts
of β-actin, cofilin, amyloid precursor protein (APP) and mitogen-activated protein kinase 1 (MAPK-1) RNAs and proteins were
investigated. The mRNA expressions of β-actin, cofilin and MAPK-1 followed U-shaped time course. Acute (3 days) and chronic
(21 days) RS caused a fourfold and tenfold increases, respectively, in hippocampal β-actin mRNA expression. In the case of
cofilin mRNA expression, elevations were detected in the hippocampus on days 3, 7 and 21. The APP mRNA level was increased
on day 21. On protein level, chronic stress elevated the levels of β-actin, cofilin and APP in the hippocampus. These results
suggest that stress causes the induction of some genes and proteins that are also elevated in AD selectively in the hippocampal
region of the rat brain. 相似文献