| 1. |
|
|
| 2. |
- Abbas, Abdul-Karim, 1959, et al.
(författare)
-
Emetine treatment masks initial LTP without affecting long-term stability.
- 2011
-
Ingår i: Brain research. - : Elsevier BV. - 1872-6240 .- 0006-8993. ; 1426, s. 18-29
-
Tidskriftsartikel (refereegranskat)abstract
- Applying emetine, a protein synthesis inhibitor, at 20-40μM for 90-120min prior to LTP induction in hippocampal slices from young rats (2-3weeks) and washing it out afterwards revealed a slowly developing potentiation that reached maximum after 20-30min, distinct from the LTP observed under normal conditions. Nevertheless, the later phase of this potentiation was similar to standard LTP as judged by experiments lasting up to 8h after induction. Emetine preapplication for 3h without subsequent washout resulted in a substantial decay of evoked responses. By comparison between test and control pathways, LTP could still be assessed in these experiments for up to 4-6h after induction and was found not to differ from normal, except for the slow onset. The NMDA-R blocker AP5 fully blocked LTP; however, with emetine pretreatment there was an initial depression of responses with a gradual recovery during 20-30min. This depression involved not only the field EPSP but also the presynaptic fiber volley. However, when using the protein synthesis inhibitors cycloheximide and anisomycin there was essentially no such depression. In conclusion, the present results support the idea that preexisting proteins are sufficient for inducing stable LTP. Moreover, emetine but not anisomycin or cycloheximide impairs presynaptic action potentials, leading to an apparent slow onset of LTP. The emetine-dependent effect could be due to a characteristic blocking spectrum of the drug, preferred targeting of presynaptic compartments or effects unrelated to protein synthesis.
|
|
| 3. |
- Abbas, Abdul-Karim, 1959, et al.
(författare)
-
Long-term potentiation and insult conditioning in hippocampal slices from young rats: a role for protein synthesis under chemical stress?
- 2010
-
Ingår i: The 10th Biennial Meeting of the Asia-Pacific Society for Neurochemistry (APSN), October 17-20, 2010, Phuket, Thailand.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- We have previously demonstrated that in young rats (12-20-day-old) a sustained long-term potentiation (LTP) can still be induced under conditions of protein synthesis inhibition. It was therefore suggested that sufficient and necessary proteins were already available at the induction time to accomplish LTP maintenance for several hours. Against this background, we have questioned whether hippocampal slices subjected to certain insult conditions might be more sensitive to protein synthesis inhibitors. High K+ concentration has previously been reported to cause an amnesic effect in vivo as well as increasing protein turnover in vitro. We have here employed a K+ insult model under conditions when protein synthesis was inhibited. Recordings were obtained from hippocampal slices for up to 9 h, with or without a cocktail of protein synthesis inhibitors, containing cycloheximide (60 µM) and anisomycin (25 µM). High potassium (50 mM) was transiently applied (5-15 min) shortly after inducing LTP in one of two separate pathways stimulated alternatively. Additionally, an NMDA-receptor antagonist AP5 was supplied after LTP induction to minimize effects related to depolarization-induced glutamate release. Following elimination of all responses for about 30 min, both test and control responses partly recovered. The degree of remaining LTP, defined as test/control ratio, was reduced in both groups of slices (NMDA-independent depotentiation) but was significantly smaller in the drug-treated ones. We are also running an insult model based on oxidative stress, applying hydrogen peroxide (4-5 mM) before or after LTP induction; however, the results are still insufficient for a final conclusion. The potency of cycloheximide, anisomycin or cocktail of the drugs was verified by measurement of incorporation of [3H]-leucine into trichloracetic acid (TCA) precipitable macromolecules. Cycloheximide, anisomycin or cocktail, at concentrations used here caused 95%, 97% and 95% blocking effect, respectively. Our data confirm the idea that sufficient and necessary constitutive proteins are available in the young hippocampus to maintain LTP under conditions of protein synthesis inhibition. They also reveal that LTP in slices subjected to certain insult conditions early after the induction is sensitive to protein synthesis inhibition, probably due to increase in constitutive proteins turnover.
|
|
| 4. |
- Abbas, Abdul-Karim, 1959, et al.
(författare)
-
Persistent LTP without triggered protein synthesis.
- 2009
-
Ingår i: Neuroscience research. - : Elsevier BV. - 0168-0102. ; 63:1, s. 59-65
-
Tidskriftsartikel (refereegranskat)abstract
- Protein synthesis is believed to be involved in stabilizing synaptic plasticity. Effects lasting longer than about 2-3h are considered to require synthesis of new proteins, implying a functional separation between early (E) and late (L) components. However, the issue of constitutive vs. new protein synthesis is still unclear, especially in young animals. Here, we examined the effects of two protein synthesis inhibitors, anisomycin and emetine, on long-term-potentiation (LTP) in CA1 area of hippocampal slices from 12- to 20-day-old rats. Either drug was applied from -30 min to +30 min with respect to LTP induction, a time window previously reported to be critical. However, the LTP remained stable under the entire recording period of 4h (anisomycin), or 8h (emetine). Proper preparation of emetine solution was evidenced by the fact that, in separate experiments, prolonged treatment with emetine gradually blocked baseline responses. Although no corresponding effect was observed with anisomycin, the drug was judged to be potent by its ability to inhibit yeast growth. The ability of anisomycin to inhibit protein synthesis was further confirmed by radiolabeling experiments assessing the degree of leucine incorporation. Our data suggest that LTP up to at least 8h is not dependent on triggered protein synthesis but can be attained by utilizing proteins already available at induction time.
|
|
| 5. |
- Abbas, Abdul-Karim, 1959, et al.
(författare)
-
Pharmacological characteristics of protein synthesis inhibitors by radioactive leucine incorporation in rat hippocampal slices: experimental evidence and pre-clinical implications
- 2011
-
Ingår i: The 23rd Biennial Meeting of the International Society for Neurochemistry (ISN), August 28-September 1 2011, Athens, Greece.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Protein synthesis inhibitors (PSIs) constitute a major tool to validate the hypothesis of protein synthesis-dependent phase of synaptic plasticity and memory consolidation. However, several reports have showed inconsistent findings about the effect of these drugs on behavioral learning and synaptic plasticity. Testing the potencies of these drugs is hence crucial for validating such negative findings and in planning future studies. It is also necessary to examine the dose dependence, onset dynamics and reversibility, and possible effects on basal proteins. Here we used the labeled leucine as marker for the newly synthesized proteins. The fraction of leucine incorporation, following 50 min of pre-incubation, was compared between two groups of slices: a PSI-treated and a control group. Both anisomycin and cycloheximide revealed a dose-dependent but time-independent manner of inhibition reaching over 92% at concentrations well below those used in previous experiments which revealed effects on synaptic plasticity and learning. Surprisingly, washout of a “reversible” inhibitor, anisomycin was not followed by rapid reversibility of the action of the drug, the case that differs with cycloheximide. Interestingly, emetine revealed a time-dependent inhibition of protein synthesis, where levels above 80% needed drug pre-incubation for as long as 90 min. Since the duration of labeling relates to the half-life of the proteins, short-time labeling as used in this study will result in radioactivity incorporation into short-lived proteins and proteins that are synthesized in large quantities. We therefore studied the availability of newly synthesized proteins at 8-10 h following leucine incorporation. The results revealed virtually the same protein content as in slices retrieved for analysis immediately following the labeling period, indicating that the main pool of the newly synthesized proteins is of intracellular long-lived pool. This likely reflects a stable metabolic state of our prepared slices. These findings challenge current idea on the role of de novo protein synthesis in synaptic plasticity as well as brain changes underlying several neurological and psychiatric disorders.
|
|
| 6. |
- Acharya, Shikha, 1986, et al.
(författare)
-
Saliva on the oral mucosa and whole saliva in women diagnosed with burning mouth syndrome
- 2018
-
Ingår i: Oral Diseases. - : Wiley. - 1354-523X. ; 24:8, s. 1468-1476
-
Tidskriftsartikel (refereegranskat)abstract
- Objective The aim of the study was to examine mucosal saliva and unstimulated (UWS) and stimulated (SWS) whole saliva secretion rates and associated factors, in 56 female patients diagnosed with BMS and age-matched control women. Material and MethodsResultsMucosal saliva was assessed using the Periotron((R)) method and blood flow using laser Doppler flowmetry. Diseases, drug usage and xerostomia were registered using questionnaires. The patients with BMS displayed less lingual and whole saliva, and more hyposalivation, xerostomia diseases/disorders and drug usage, compared to the controls. Only a low SWS and xerostomia differed after adjusting for drugs and systemic diseases. Regression analyses suggested an importance of saliva affecting drugs for saliva on the tongue and for SWS, and the total number of drugs used for UWS. Lingual saliva and UWS were also associated with systemic diseases in the patients. Xerostomia was significantly associated with drug use and whole saliva for all subjects but not in separate analyses of the groups. ConclusionLess saliva in patients with BMS could be related to more systemic diseases and medication and not to the syndrome per se. Xerostomia in the patients was not related to any of these factors.
|
|
| 7. |
- Aliko, A., et al.
(författare)
-
World Workshop on Oral Medicine VI: clinical implications of medication-induced salivary gland dysfunction
- 2015
-
Ingår i: Oral Surgery Oral Medicine Oral Pathology Oral Radiology. - : Elsevier BV. - 2212-4403. ; 120:2, s. 185-206
-
Tidskriftsartikel (refereegranskat)abstract
- Objective. This study aimed to systematically review the available literature on the clinical implications of medication-induced salivary gland dysfunction (MISGD). Study Design. The systematic review was performed using PubMed, Embase, and Web of Science (through June 2013). Studies were assessed for degree of relevance and strength of evidence, based on whether clinical implications of MISGD were the primary study outcomes, as well as on the appropriateness of study design and sample size. Results. For most purported xerogenic medications, xerostomia was the most frequent adverse effect. In the majority of the 129 reviewed papers, it was not documented whether xerostomia was accompanied by decreased salivary flow. Incidence and prevalence of medication-induced xerostomia varied widely and was often associated with number and dose of medications. Xerostomia was most frequently reported to be mild-to-moderate in severity. Its onset occurred usually in the first weeks of treatment. There was selected evidence that medication-induced xerostomia occurs more frequently in women and older adults and that MISGD may be associated with other clinical implications, such as caries or oral mucosal alterations. Conclusions. The systematic review showed that MISGD constitutes a significant burden in many patients and may be associated with important negative implications for oral health.
|
|
| 8. |
- Cabras, Tiziana, et al.
(författare)
-
Carbachol-induced in vitro secretion of certain human submandibular proteins investigated by mass-spectrometry.
- 2008
-
Ingår i: Archives of oral biology. - : Elsevier BV. - 1879-1506 .- 0003-9969. ; 53:11, s. 1077-83
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To investigate protein content of saliva produced in vitro by samples of human submandibular gland following stimulation with the muscarinic agent carbachol. DESIGN: Tissue samples, obtained at surgery from seven patients and showing normal morphological appearance, were tested for 30 min: in absence of carbachol and atropine; in presence of carbachol (10 microM); in presence of carbachol (10 microM) and atropine (20 microM); or in presence of just atropine (20 microM). Medium was analysed by high-performance liquid chromatography-mass-spectrometry. Neither before nor during surgery were the patients exposed to drug treatments that were likely to influence the in vitro secretion. RESULTS: Proline-rich proteins (PRP)-1 and -3, peptide PC and PB, statherin, cystatins SN, S1 and S2 were invariably found in control gland tissue medium. Mean concentrations of these proteins/peptides in the medium were non-proportionally elevated following carbachol exposure to the gland tissues. Difference between basal release and carbachol-induced secretion achieved statistical significance as to all the proteins/peptides under study but for statherin. Atropine alone or atropine plus carbachol caused no significant changes compared to the basal release of proteins/peptides. CONCLUSIONS: In vitro studies on salivary glands make it possible to study protein secretion from individual glands and thus, to reveal the contribution of the various types of gland to protein/peptide content of whole saliva. The disproportional responses to carbachol may imply that the proteins/peptides are not confined to the same cells or to the same intracellular locations and are therefore not secreted as packages at parasympathetic cholinergic activity.
|
|
| 9. |
- Cabras, T., et al.
(författare)
-
Marked Differences in the Submandibular Salivary Proteome between Sardinian Alcohol-Preferring and Sardinian Alcohol-Non Preferring Rats Revealed by an Integrated Top-Down-Bottom-Up Proteomic Platform
- 2018
-
Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 17:1, s. 455-469
-
Tidskriftsartikel (refereegranskat)abstract
- Sardinian alcohol-preferring (sP) and Sardinian alcohol-non preferring (sNP) rats have been selectively bred for opposite alcohol preference and consumption. Aiming to verify possible differences at the proteomics level between sP and sNP rats, we investigated the salivary proteome by a a liquid chromatography-mass spectrometry top-down-bottom-up integrated approach. For this purpose, submandibular saliva was collected from alcohol-naive sP and sNP rats under isoprenaline stimulation. A total of 200 peptides and proteins were detected and quantified in the two rat lines, 149 of which were characterized in their naturally occurring structure. The data are available via ProteomeXchange with identifier PXD006997. Surprisingly, sP rats exhibited marked quantitative and qualitative differences with respect to sNP rats, namely higher levels of proteoforms originating from submandibular gland protein C, and from submandibular rat protein 2, as well as those of several unidentified peptides and proteins. sP rats expressed some proteins not detectable in sNP rats such as the glutamine and glutamic acid-rich protein (GRP)-CB. The isoform GRP-B, detectable in both rat lines, was more abundant in sNP rats. The submandibular saliva of sNP rats was also characterized by very high levels of GRP-B proteolytic peptides and rat salivary protein 1. Whether these differences could contribute to the opposite alcohol preference and consumption of sP and sNP rats is currently unknown and requires further investigation. © 2017 American Chemical Society.
|
|
| 10. |
- Cabras, T., et al.
(författare)
-
Proteomics of the acid-soluble fraction of whole and major gland saliva in burning mouth syndrome patients
- 2019
-
Ingår i: Archives of Oral Biology. - : Elsevier BV. - 0003-9969. ; 98, s. 148-155
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: In the present study the salivary proteome of burning mouth syndrome patients and healthy subjects was characterized by a top-down proteomic approach and compared to highlight possible qualitative and quantitative differences that may give suggestions about the causes of this pathology which are still unknown. Materials and methods: Resting and stimulated whole saliva, stimulated parotid and submandibular/sublingual saliva samples were collected from burning mouth syndrome patients (n = 16) and age- and gender-matched healthy subjects (n = 14). An equal volume of 0.2% trifluoroacetic acid was added to each sample immediately after collection and the supernatants were analysed by liquid chromatography coupled to electrospray-ionisation mass spectrometry. Proteins and peptides were quantified using a label-free approach measuring the extracted ion current peak areas of the main salivary proteins and peptides. Results: The quantitation of the main salivary proteins and peptides revealed a higher concentration of cystatin SN in resting saliva of burning mouth syndrome patients with respect to healthy controls and no other conspicuous changes. Conclusions: The reported data showed that the salivary protein profile was not affected, in composition and relative abundance, by the burning mouth syndrome, except for the cystatin SN, a protein up-regulated in several pathological conditions, that might be considered potentially indicative of the disease. © 2018
|
|
