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ENDOCRINE AND DIABETES
Departments of Clinical Biochemistry (A.J., S.Z.B.) and Immunology (M.Z.H.), Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; and Endocrine Division, Vali-Asr Hospital, Medical Sciences, University of Tehran, Tehran, Iran (M.N.)
Received August 31, 2007; accepted November 12, 2007.
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Abstract |
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).
Heat shock proteins (HSPs), also called stress proteins, are a highly diverse, evolutionarily conserved family of proteins containing both constitutively expressed and stress-inducible members. HSPs are up-regulated in response to thermal stress and a wide variety of other physical and chemical insults. HSP70 is one of the major stress protein families found in a variety of organisms, and these molecules play central roles in protein folding as molecular chaperones (Craig et al., 1994). Treatments that induce HSPs have been associated with the development of a resistant state where the organism is protected from subsequent toxicity, suggesting that increased HSP expression constitutes an important cellular defense mechanism (Tolson and Roberts, 2005). Some studies have shown that expression of these chaperones that are required to maintain the integrity of protein structure is reduced during the course of diabetes, and such alterations may result in the onset of complications of diabetes (Kurucz et al., 2002; Atalay et al., 2004).
Due to the high possibility of proteins glycation and their structural changes, elevating chaperone capacity in diabetic patients is reasonable for protection of proteins against these changes and conservation of native structure. Therefore, applying the process or compounds that elevate the level of chaperoning activity in the diabetic models may be a useful way for treatment of this conformational disease.
Acetyl salicylic acid (aspirin or ASA) is a nonsteroidal anti-inflammatory drug that has been in general use since the end of the last century. ASA is absorbed intact in the gastrointestinal tract. As the drug circulates in the plasma, it is readily hydrolyzed to salicylic acid and acetate ion (Kelly, 1970). After oral administration of aspirin in human, only 68% of the ingested dose reaches the systemic circulation as aspirin, where it is converted into salicylate, spontaneously or by nonspecific esterases. The half-life of aspirin has been reported to be approximately 12.6 and 20 min in rat and human, respectively, and 6 days in the in vitro condition (Bakar and Niazi, 1983; Jackson and Morrow, 2001). According to our previous study, pseudo-first order rate constant and the half-life of aspirin hydrolysis in 0.05 M Tris buffer, pH 7.4, were obtained at 0.0195 ± 0.0023 k/h and 35.79 ± 3.39 h, respectively (unpublished data).
Low-dose aspirin treatment due to block of thromboxane synthesis by acetylating platelet cyclooxygenase is a standard therapeutic approach in diabetes mellitus for primary and secondary prevention of long-term vascular complications (Colwell, 2004). In addition, multiple animal models and human studies have indicated the salutary effects of ASA as an anticataract (Rao et al., 1985; Shastri et al., 1998) and antiglycating agent in diabetes (Urios et al., 2007). On the other hand, it was reported that high-dose aspirin therapy before heat treatment results in induction of HSPs in the rat skin (Ghavami et al., 2002), but the affect of ASA as a chaperone inducer or as a protector of protein structure was not studied in diabetes mellitus.
Thus, we decided to examine whether high-dose and long-term use of aspirin would ameliorate the conformational changes of proteins and/or affect their activity in diabetic rats. We investigated the effect of ASA, administered in drinking water for 5 months on diabetic rats from different aspects such as inducing heat shock proteins (HSP70) and protective effect on protein structure and function and hence its effect on serum glucose and insulin level, AGE and glycated hemoglobin (HbA1c) formation, lipid profile, HDL functionality (paraoxonase1 and LCAT activities), and the status of the antioxidant defense system. In addition, the in vitro effect of ASA on the structure of albumin as a model protein was studied in the presence of glucose by spectroscopic techniques such as fluorometry and circular dichroism (CD).
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In Vivo Studies
Design of in Vivo Study. Male Wistar rats, 8 weeks old and weighing 240 ± 20 g, were housed under controlled temperature conditions with a 12-h light/12-h dark cycle. After 3 weeks, they were divided into four groups of seven to nine animals. Two groups (named G2 and G4) received injections i.p. with streptozotocin (50 mg/kg body weight in Na+-citrate buffer, pH 4.5) (Mendez and Ramos, 1994). If the blood glucose level was <270 mg/dl after 4 days, the injection was repeated once, and thereafter only rats with blood glucose levels 
270 mg/dl were included in our experiments. Control rats (groups G1 and G3) received injections with vehicle alone. The experimental protocol was approved by the Animal Ethical Committee in accordance with the guidelines for the care and use of laboratory animals prepared by Tarbiat Modares University.
The treatment of diabetic and healthy groups (groups G4 and G3) with 100 mg/kg ASA in drinking water began after 1 week (time 0 in the figures and tables). The dose of aspirin was chosen for its ability to induce HSP in rats (Ghavami et al., 2002), and the drinking water was replaced two times a day. The study continued up to the end of month 5. After that, all animals were killed, and their organs were stored at -70°C for further studies.
Blood samples were collected from the orbit vein every 30 days for 5 months. EDTA-treated whole-blood samples were saved for HbA1c determination, and sera samples, prepared by 15-min centrifugation of blood at 5000g to separate clot, were stored at -70°C for further studies. Urine samples collected through metabolic cages every 30 days for 5 months. For this purpose, rats were kept in separate metabolic cages for 6 h.
Determination of Fasting Serum Glucose, Lipid Profile, and Insulin Levels. Sera glucose, total cholesterol (TC), and triglyceride (TG) levels were measured by enzymatic colorimetric methods (Pars Azmune, Tehran, Iran), using AutoAnalyzer Model Selectera 2. After precipitation of non-HDL-c lipoproteins by phosphotungstic acid and magnesium chloride in the sera, HDL-c was determined by an enzymatic colorimetric method (Pars Azmune). LDL-c was calculated according to the Friedewald formula for less than 400 mg/dl TG-containing samples (Friedewald et al., 1972). The Rat Insulin ELISA kit (Mercodia Corporation, Uppsala, Sweden) was used to measure serum insulin level.
HbA1c Measurement and AGE and FRAP Assay. HbA1c was measured by ion exchange chromatography method (Biosystems S.A., Barcelona, Spain). AGE determination was performed according to the method of Kalousová et al. (2002). Blood serum was diluted 1:50 with PBS, pH 7.4, and fluorescence intensity was recorded at the emission maximum (440 nm) upon excitation at 350 nm using the spectrofluorometer Shimadzu, model RF 5000 (Shimadzu, Kyoto, Japan). Fluorescence intensity was expressed as percentage of fluorescent emission.
The reducing ability of biological samples was determined by the FRAP assay of Benzie and Stain (1996). FRAP assay measures the change in the absorbance of FRAP reagent at 593 nm (Spectrophotometer Shimadzu, model 3101) due to the formation of a blue-colored Fe II-tripyridyltriazine complex from colorless oxidized Fe III formed by the action of electron-donating antioxidants in the serum.
Microalbuminuria Determination. Albumin content of urine samples was determined by ELISA kit (Orgentec, Mainz, Germany).
Determination of Serum Hsp70 Level. Serum Hsp70 was measured using a commercially available ELISA kit (StressGen Biotechnologies, Victoria, BC, Canada). The standard curve was plotted between 0.78 and 50 ng/ml of protein in the solution. The sensitivity of the assay was 0.2 ng/ml. The concentrations of the Hsp70 protein in the serum were determined using the standard curve.
Paraoxonase1 and LCAT Assay. Paraoxonase1 (PON1) activity was determined using paraoxon (O,O-diethyl-O-p-nitrophenylphosphate; Sigma Chemical Co.) as the substrate and measured by the increase in the absorbance at 412 nm due to the formation of 4-nitrophenol (Ferretti et al., 2001). In brief, the activity was measured at 25°C, by adding 50 ml of serum to 1 ml of Tris-HCl buffer (100 mM, pH 8.0) containing 2 mM CaCl2 and 5.5 mM paraoxon. The rate of generation of 4-nitrophenol was determined at 412 nm by using a UV-visible spectrophotometer. Enzymatic activity was calculated using the molar extinction coefficient of substrate (17,100 M-1 cm-1). LCAT activity was determined by a commercially available LCAT kit (Roar Biomedical, Inc., New York, NY) based on the fluorescence decrement of the hydrolyzing substrate.
Statistical Analyses. All data were expressed as mean ± S.D. Statistical comparisons were performed by one-way analysis of variance with least significant difference multiple comparison post-test analysis. Significance was set at p < 0.05.
In Vitro Studies
Glycation of BSA. The stock solution of BSA was prepared by dissolving it in PBS, pH 7.4. This solution was subsequently diluted with glucose solution made in the same buffer to form duplicate incubation mixtures of 10 mg/ml protein with 50 mM glucose in the absence and presence 20 mM ASA (Shaklai et al., 1984). After being sterilized by filtration (0.22-µm filters; Millipore Corporation, Billerica, MA), the solutions were incubated at 37°C for 60 days in capped vials. Aliquots were collected every week, and unbound glucose and ASA were removed from BSA solution by extensive dialysis against PBS, pH 7.4, and stored at -80°C until they were analyzed by fluorometry and CD.
Fluorometry and CD Analyses. Production of fluorescent compounds or glycophors was monitored in samples with a concentration of 0.5 mg/ml BSA using a spectrofluorometer (Shimadzu, RF-5000) at excitation and emission wavelengths of 350 and 425 nm, respectively (Ogino and Okada, 1995). CD spectra were measured in a JASCO-810 spectropolarimeter (Jasco, Tokyo, Japan). The samples with a concentration of 0.1 mg/ml BSA were used for secondary structure analysis. The spectra have been smoothed and are presented in units of mean residue molar ellipticity. All measurements were performed at 25°C. The helicity of BSA estimated by using the simple assumption that 
222 for 100% helix is given by 40,000 x [(n - 4)/n], where n is the number of residues (Jackson et al., 1991), which is 585 in this case.
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In the study of lipid profile, our results (Fig. 2, A–D) show that the TG, TC, and LDL-c levels increases significantly in diabetic rats. However, these parameters significantly decreased under the effect of ASA administration during the course of the experiment. In addition, the HDL-c that decreased significantly after diabetes induction significantly increased in the diabetic group treated with ASA.
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Table 2 shows the activity of paraoxonase1 and LCAT during the experimental course. As illustrated in this table, the activity of these enzymes decreased due to the diabetes induction. The decreased paraoxonase1 activity was significantly (p < 0.05) compensated by ASA 2 months after the beginning of the experiment. Meanwhile, the improvement effect of ASA on LCAT activity was not significant.
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The results in the Fig. 3 indicate that FRAP decreases gradually in the diabetic group in comparison with the control group and reaches the minimum at month 5 of experiment (p < 0.05). Nevertheless, ASA suppresses the decreased amount in the diabetic group and retains the values near to the normal.
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Renal excretion of Alb (microalbuminuria), as an index of kidney function, was determined in the urine of rats. Table 4 shows a significant (p < 0.001) increase in this parameter after the 4th month of the experiment in the diabetic group, but no significant changes were observed in the diabetic group under treatment with ASA. No evidence of gross anatomical pathology, stomach hemorrhages, or ulceration was observed in both aspirin-treated groups, except one tumor, which was diagnosed as fibrosarcoma, in one of the animals in the control group receiving aspirin.
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In Vitro Studies. The structural changes of BSA were studied as a model protein due to the high concentrations of glucose in the absence and presence of ASA. Figure 4A shows that incubation of BSA with 50 mM glucose results in a progressive increase in the fluorescence emission of glycophors from the 4th week of the beginning of the experiment, whereas in the presence of ASA, there is not a considerable change in fluorescence emission in comparison with the native BSA. The similar results were observed at 100 mM glucose.
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). Hence, attempts have been made to pharmacologically prevent or slow down the glycation of proteins and control the pathogenesis of the disease. ASA, which was synthesized as a painkiller and antifever drug more than 100 years ago, has been applied for various therapeutic applications. This multifunctional drug affects different systems and metabolic pathways in the body with various mechanisms. The present study investigated these mechanisms in diabetic rats.
Figure 1B indicates a slight decrease in the serum glucose level of diabetic rats after ASA treatment. The hypoglycemic effect of ASA through the decrease in the intestinal absorption of glucose (Arvanitakis et al., 1977), reduction in the hepatic gluconeogenesis (Hundal et al., 2002), and the decrease in the insulin clearance (Hundal et al., 2002) has been reported previously in human subjects, normal or insulin resistant. However, it was pointed out that nonsteroidal antiinflammatory drugs should not be considered as therapy for hyperglycemia (Mork and Robertson, 1983).
Our results also indicated (Table 1) a slight and nonsignificant increase in the serum insulin level due to the ASA administration to diabetic rats. As seen in Fig. 1B, there is not any increase in the weight of diabetic rats due to ASA treatment. It shows that a low increase in insulin level is not enough, not only for a significant reduction of glucose, but also for activation of the biosynthetic pathways.
ASA has been known as an inhibitor of glycation through acetylation of 
-NH2 groups of lysine (Rao et al., 1985; Urios et al., 2007). Thus, the decreased levels of AGEs (Fig. 1C) and HbA1c formation (Table1) in diabetic rats treated with ASA in comparison with the untreated group may be explained by the mentioned mechanism. In addition, a decrease in serum glucose level can be another reason for reduced AGEs and HbA1c. Similar changes in the AGEs (Urios et al., 2007) and HbA1c (Lapshina et al., 2006) have been reported elsewhere.
The in vitro data in Fig. 4 also confirm our in vivo results. The fluorescence intensity changes in the presence of glucose alone show a gradual increase up to the 2nd month of experiment, which indicate the formation of AGE compounds. However, this figure indicates that ASA prevents the formation of these glycophors, and the fluorescence intensity of samples remains on the basal level. The data on Fig. 4 also show that the BSA conformation maintains, against structural changes due to the glycation, in the presence of ASA. The CD spectra of BSA in the presence of glucose indicated that the 
-helical content of protein reduced significantly, but ASA conserved the secondary structure as the native one. It has been reported previously that serum albumin is acetylated in the presence of ASA (Hawkins et al., 1969). Our data confirm that ASA has a protective role on protein structure against nonenzymatic glycation and its subsequent events.
Hyperlipidemia independently increases the risk of cardiovascular mortality among patients with diabetes mellitus. Our results show a significant reduction in the levels of TC, TG, and LDL-c and a significant elevation in HDL-c in the diabetic group treated with ASA in comparison with diabetic rats without treatment (Fig. 2). These findings are in agreement with the results obtained in human subjects with type II diabetes (Hundal et al., 2002), in hypercholesterolemic rats (Tauseef et al., 2007), and in normal rats (Nakagawa et al., 1984). The direct antilipolytic effect on adipocytes, which reduced plasma free fatty acids, has been suggested as one of the mechanisms involved for these findings (Hundal et al., 2002).
As mentioned above, ASA can prevent protein glycation and hence conserve the protein structure and function. Thus, we investigated the activity of two important enzymes related to the HDL functionality. Our results show that the decreased activity of LCAT (Fournier et al., 1995) and paraoxonase1 (Mackness et al., 2002) due to diabetes induction improves significantly by ASA. An increase in the LCAT activity of serum due to the oral administration of ASA or salicylic acid, at a short-term study (3 days), has previously been reported (Nakagawa et al., 1984). It has also been shown that aspirin administration is associated with higher serum concentration and activity of PON1 in normal subjects (Blatter-Garin et al., 2003). Because PON1 is known as a powerful antioxidant system in plasma that delays the LDL oxidation, it prevents atherosclerosis, so the increase in its functionality has a key role in cardioprotection. In addition, the antioxidant property of salicylic acid, as a main metabolite of ASA, has been reported (Sagone and Husney, 1987). It was also shown that PON1 can use ASA as a substrate to produce more salicylate ions (Santanam and Parthasarathy 2007). Thus, by using ASA, the antioxidant capacity, which decreased in diabetic patients, must be compensated. This assumption is confirmed not only by the observed increase in PON1 activity in diabetic rats but also by our data about FRAP assay. Figure 3 shows that the antioxidant capacity of plasma increased due to ASA administration to diabetic rats, in comparison with the untreated rats.
There are a few reports about the effect of ASA or SA on HSP70 level. Activation of the heat shock factor binding to heat shock elements in DNA by sodium salicylate has been reported in the HeLa cells (Jurivich et al., 1992). It has also been reported that short-term use (30 min) of aspirin has no significant effect on the HSP70 induction in the rat liver, kidney, and lung (Fawcett et al., 1997). However, the induction of HSP70 in the rat skin, due to the high-dose and short-term administration of ASA before heat treatment, has been shown (Ghavami et al., 2002). In a recent study, it has been demonstrated that ASA and some other nonsteroidal anti-inflammatory drugs (NSAIDs) cause the induction of HSP70 in mast cells (Mortaz et al., 2006a,b). Diabetes causes a reduction in serum HSP70 level (Table 3) due to glycation, misfolding, and inactivation of this protein (data not shown), which leads to removing it from the circulation or even the inability of monoclonal antibody to detect it. For the first time, we investigated the effect of high-dose and long-term use of ASA on serum HSP70 in diabetic and normal rats. Table 3 shows the increase in the serum HSP due to ASA administration in both groups. However, these increases are not significant in the normal group and significant in the diabetic group (p < 0.05) in comparison with the untreated groups. ASA induces the HSP70 in both groups receiving it. Thus, it can affect the protein stability and folding patterns.
In addition, ASA and some other NSAIDs inhibit the release of proinflammatory cytokines through inhibition of signaling pathways, including the nuclear factor 
B and the mitogen-activated protein/p38 pathways (Mortaz et al., 2006a). This novel finding, which has been explained as a cyclooxygenase-independent anti-inflammatory effect of NSAIDs (Mortaz et al., 2006a), may be used as an affirmative reason for administration of ASA as an antidiabetic drug.
The accumulation of AGEs on collagen may cause the loss of glomerular function (Monnier et al., 1992). Aspirin has been inhibited by the formation of pentosidine, as an AGE product, in collagen incubated with glucose in an in vitro study (Urios et al., 2007). We assume that if the same mechanism happens in vivo, the improvement effect must be seen in the microalbuminuria. However, as Table 4 reveals, aspirin does not show such an effect. These findings are in agreement with those obtained by others (Kern and Engerman, 2001).
Aspirin at 100 mg/kg is an anti-inflammatory and prostaglandin inhibitor in rodents, similar to a single 1-g dose in man. However, the cardioprotective doses of aspirin in human are 75 to 150 mg (approximately 1–10 mg/kg in rodents). In contrast to the adverse effects (gastrointestinal and kidney disorders) that have been reported for such high doses in human, in the present study, we do not see any side effects on rats. In addition, diabetic rats that received ASA in comparison with a group without it had a 40% reduction in mortality. This is an important finding that is the result of the beneficial effects of ASA such as prevention of glycated protein formation, lipid profile and HDL functionality, antioxidant capacity, HSP induction, and, in summary, protein structure conservation and protection. Would the same effects be obtained with a correspondingly lower dose in human? It is an important question that must be answered in the future.
Finally, the following reasons are suggested for the usefulness of ASA in diabetes: These explanations were confirmed by our in vitro results. ASA is one of the agents that can prevent in vitro and in vivo glycation of proteins by different mechanisms, including the following: 1) Hsp70 induction, 2) an increase in the antioxidant activity, 3) chemical competition with protein glycation through acetylation of free amino groups in proteins, and 4) chemical chaperone-like activity to protect the structure and function of the proteins, including that involved in the glucose and lipid metabolism.
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Acknowledgements |
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Footnotes |
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Article, publication date, and citation information can be found at http://jpet.aspetjournals.org.
ABBREVIATIONS: HSP, heat shock protein; ASA, acetyl salicylic acid (aspirin); AGE, advanced glycated end product; HbA1c, glycated hemoglobin; LCAT, lecithin cholesterol acyltransferase; HDL-c, high-density lipoprotein-cholesterol; CD, circular dichroism; TC, total cholesterol; TG, triglyceride; LDL-c, low-density lipoprotein-cholesterol; ELISA, enzyme-linked immunosorbent assay; PBS, phosphate-buffered saline; FRAP, ferric-reducing ability of plasma; PON1, paraoxonase1; BSA, bovine serum albumin; STZ, N-[methylnitrosocarbamoyl]-D-glucosamine (streptozotocin); NSAID, nonsteroidal anti-inflammatory drug.
Address correspondence to: Dr. S. Zahra Bathaie, Department of Clinical Biochemistry, Faculty of Medical Sciences, Tarbiat Modares University, P.O. Box 14115-111, Tehran, Iran. E-mail: bathai_z{at}modares.ac.ir
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References |
|---|
|
TopAbstractMaterials and MethodsResultsDiscussionReferences |
|---|
Arvanitakis C, Chen GH, Folscroft J, and Greenberger NJ (1977) Effect of aspirin on intestinal absorption of glucose, sodium, and water in man. Gut 18: 187-190.
Atalay M, Oksala NK, Laaksonen DE, Khanna S, Nakao C, Lappalainen J, Roy S, Hänninen O, and Sen CK (2004) Exercise training modulates heat shock protein response in diabetic rats. J Appl Physiol 97: 605-611.
Bakar SK and Niazi S (1983) Stability of aspirin in different media. J Pharm Sci 72: 1024-1026.[CrossRef][Medline]
Benzie IF and Stain JJ (1996) The ferric reducing ability of plasma (FRAP) as a measure of antioxidant power: the FRAP assay. Anal Biochem 239: 70-76.[CrossRef][Medline]
Blatter-Garin MC, Kalix B, De Pree S, and James RW (2003) Aspirin use is associated with higher serum concentrations of the anti-oxidant enzyme, paraoxonase-1. Diabetologia 46: 593-594.[Medline]
Brownlee M (1995) The pathological implications of proteins glycation. Clin Invest Med 18: 275-281.[Medline]
Colwell JA; American Diabetes Association (2004) Aspirin therapy in diabetes. Diabetes Care 27: S72-S73.[CrossRef][Medline]
Craig EA, Weissman JS, and Horwich AL (1994) Heat shock proteins and molecular chaperones: mediators of protein conformation and turnover in the cell. Cell 78: 365-3728.[CrossRef][Medline]
Fawcett TW, Xu Q, and Holbrook NJ (1997) Potentiation of heat stress-induced hsp70 expression in vivo by aspirin. Cell Stress Chaperones 2: 104-109.[CrossRef][Medline]
Ferretti G, Bacchetti T, Marchionni C, Caldarelli L, and Curatola G (2001) Effect of glycation of high density lipoproteins on their physicochemical properties and on paraoxonase activity. Acta Diabetol 38: 163-169.[CrossRef][Medline]
Fournier N, Myara I, Atger V, and Moatti N (1995) Reactivity of lecithin-cholesterol acyltransferase (LCAT) towards glycated high-density lipoproteins (HDL). Clin Chim Acta 234: 47-61.[CrossRef][Medline]
Friedewald WJ, Levy RJ, and Fredrikson DS (1972) Estimation of the concentration of low-density lipoprotein cholesterol in plasma without use of the preparative ultracentrifuge. Clin Chem 18: 499-502.[Abstract]
Ghavami A, Nutt MP, and Hardy SP (2002) Heat shock protein and high-dose aspirin: effects on random skin flap survival in a rat model. Ann Plast Surg 48: 60-67.[CrossRef][Medline]
Harding JJ and Ganea E (2006) Protection against glycation and similar post-translational modifications of proteins. Biochem Biophys Acta 1764: 1436-1446.[Medline]
Hawkins D, Pinckard RN, Crawford IP, and Farr RS (1969) Structural changes in human serum albumin induced by ingestion of acetylsalicylic acid. J Clin Invest 48: 536-542.[Medline]
Hundal RS, Petersen KF, Mayerson AB, Randhawa PS, Inzucchi S, Shoelson SE, and Shulman GI (2002) Mechanism by which high-dose aspirin improves glucose metabolism in type 2 diabetes. J Clin Invest 109: 1321-1326.[CrossRef][Medline]
Jackson DY, King DS, Chmielewski J, Singh S, and Schultz PG (1991) General approach to the synthesis of short alpha-helical peptides. J Am Chem Sci 113: 9391-9392.[CrossRef]
Jackson Roberts L II and Morrow JD (2001) Analgesic-antipyretic and antiinflammatory agents and drugs employed in the treatment of gout, in The Pharmacological Basis of Therapeutics (Hardman JG, Limbird LE, and Goodman Gilman A eds) pp 687-731, 10th ed, McGraw-Hill, New York.
Jurivich DA, Sistonen L, Kroes RA, and Morimoto RI (1992) Effect of sodium salicylate on the human heat shock response. Science 255: 1243-1245.
Kalousová M, Skrha J, and Zima T (2002) Advanced glycation end-products and advanced oxidation protein products in patients with diabetes mellitus. Physiol Res 51: 597-604.[Medline]
Kelly CA (1970) Determination of the decomposition of aspirin. J Pharni Sci 59: 1053-1079.[CrossRef]
Kern TS and Engerman RL (2001) Pharmacological inhibition of diabetic retinopathy aminoguanidine and aspirin. Diabetes 50: 1636-1642.
Kurucz I, Morva A, Vaag A, Eriksson KF, Huang X, Groop L, and Koranyi L (2002) Decreased expression of heat shock protein 72 in skeletal muscle of patients with type 2 diabetes correlates with insulin resistance. Diabetes 51: 1102-1109.
Lapshina EA, Sudnikovich EJ, Maksimchik JZ, Zabrodskaya SV, Zavodnik LB, Kubyshin VL, Nocun M, Kazmierczak P, Dobaczewski M, Watala C, et al. (2006) Antioxidative enzyme and glutathione S-transferase activities in diabetic rats exposed to long-term ASA treatment. Life Sci 79: 1804-1811.[CrossRef][Medline]
Mackness B, Durrington PN, Boulton AJ, Hine D, and Mackness MI (2002) Serum paraoxonase activity in patients with type 1 diabetes compared to healthy controls. Eur J Clin Invest 32: 259-264.[CrossRef][Medline]
Mendez JD and Ramos GHB (1994) Animal models in diabetes research. Arch Med Res 25: 367-375.[Medline]
Monnier VM, Sell DR, Nagaraj RH, Miyata S, Grandhee S, and Odetti P (1992) Maillard reaction-mediated molecular damage to extracellular matrix and other tissue proteins in diabetes, aging and uremia. Diabetes 41: 36-41.[Medline]
Mork NL and Robertson RP (1983) Effects of nonsteroidal antiinflammatory drugs in conventional dosage on glucose homeostasis in patients with diabetes. Western J Med 139: 46-49.[Medline]
Mortaz E, Redegeld FA, Bloksma N, Dunsmore K, Denenberg A, Wong HR, Nijkamp FP, and Engels F (2006a) Induction of HSP70 is dispensable for anti-inflammatory action of heat shock or NSAIDs in mast cells. Exp Hematol 34: 414-423.[CrossRef][Medline]
Mortaz E, Redegeld FA, Nijkamp FP, Wong HR, and Engels F (2006b) Acetylsalicylic acid-induced release of HSP70 from mast cells results in cell activation through TLR pathway. Exp Hematol 34: 8-18.[CrossRef][Medline]
Nakagawa M, Takahashi R, Johsaki S, Honda T, Kiyozumi M, and Kojima S (1984) Effects of aspirin and salicylic acid on lecithin-cholesterol acyltransferase and cholesterol content in rat serum. Biochem Pharmacol 33: 2815-2817.[CrossRef][Medline]
Ogino T and Okada S (1995) Oxidative damage of bovine serum albumin and other enzyme proteins by iron-chelate complexes. Biochem Biophys Acta 1245: 359-365.[Medline]
Rao GN, Lardis MP, and Cotlier E (1985) Acetylation of lens crystallins: a possible mechanism by which aspirin could prevent cataract formation. Biochem Biophys Res Commun 128: 1125-1132.[CrossRef][Medline]
Sagone AL Jr and Husney RM (1987) Oxidation of salicylates by stimulated granulocytes: evidence that these drugs act as free radical scavengers in biological systems. J Immunol 138: 2177-2183.[Abstract]
Santanam N and Parthasarathy S (2007) Aspirin is a substrate for paraoxonase-like activity: implications in atherosclerosis. Atherosclerosis 191: 272-275.[CrossRef][Medline]
Shaklai N, Garlick RL, and Bunn HF (1984) Nonenzymatic glycosylation of human serum albumin alters its conformation and function. J Biol Chem 259: 3812-3817.
Shastri GV, Thomas M, Victoria AJ, Selvakumar R, Kanagasabapathy AS, Thomas K, and Lakshmi (1998) Effect of aspirin and sodium salicylate on cataract development in diabetic rats. Indian J Exp Biol 36: 651-657.[Medline]
Tauseef M, Sharma KK, and Fahim M (2007) Aspirin restores normal baroreflex function in hypercholesterolemic rats by its antioxidative action. Eur J Pharm 556: 136-143.[CrossRef][Medline]
Tolson JK and Roberts SM (2005) Manipulating heat shock protein expression in laboratory animals. Methods 35: 149-157.[CrossRef][Medline]
Urios P, Grigorova-Borsos AM, and Sternberg M (2007) Aspirin inhibits the formation of pentosidine, a cross-linking advanced glycation end product, in collagen. Diabetes Res Clin Pract 77: 337-340.[CrossRef][Medline]
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