scholarly journals Immunological detection of fructated proteins in vitro and in vivo

1998 ◽  
Vol 336 (1) ◽  
pp. 101-107 ◽  
Author(s):  
Nobuko MIYAZAWA ◽  
Yoshimi KAWASAKI ◽  
Junichi FUJII ◽  
Myint THEINGI ◽  
Ayumu HOSHI ◽  
...  
Keyword(s):  
Reducing Sugars ◽  
Early Stage ◽  
Polyol Pathway ◽  
Diabetic Rat ◽  
Dependent Manner ◽  
Glycation End Products ◽  
Lysine Residues ◽  
Activity Of Enzymes

An antibody has been raised against fructated lysine in proteins by immunizing fructated lysine-conjugated ovalbumin in rabbits. The affinity-purified antibody specifically recognized proteins incubated with fructose but not with other reducing sugars such as glucose, galactose or ribose, as judged by immunoblotting and ELISA techniques. Competitive binding to this antibody was observed specifically by fructated lysine but not by glucated lysine, glucose, fructose or lysine. The antibody binds specifically to fructated lysine residues in the protein but not to borohydride-reduced material or advanced glycation end products, indicating that the antibody recognizes only the reducing, carbonyl-containing forms produced in the early stage of the fructation reaction. When BSA was incubated with various concentrations of fructose, the reactivity of the antibody increased in a dose- and time-dependent manner. When soluble proteins prepared from either normal or streptozotocin-induced diabetic rat eyes were analysed by ELISA with this antibody, an increase in the reactive components was observed as a function of aging as well as under diabetic conditions. Western blotting analysis showed that lens crystallin reacted highly with this antibody. Because fructose is biosynthesized largely through the polyol pathway, which is enhanced under diabetic conditions, and lens is known to have a high activity of enzymes in this pathway, this antibody is capable of recognizing fructated proteins in vivo. Thus it is a potentially useful tool for investigating two major issues that seem to be involved in diabetic complications, namely the glycation reaction and the polyol pathway.

scholarly journals Ethyl Pyruvate Prevents Renal Damage Induced by Methylglyoxal-Derived Advanced Glycation End Products

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Eunsoo Jung ◽  
Wan Seok Kang ◽  
Kyuhyung Jo ◽  
Junghyun Kim
Keyword(s):  
Advanced Glycation End Products ◽  
Ethyl Pyruvate ◽  
Renal Diseases ◽  
Dependent Manner ◽  
Advanced Glycation ◽  
Glycation End Products ◽  
End Products ◽  
Cross Links

The renal accumulation of advanced glycation end products (AGEs) is a causative factor of various renal diseases, including chronic kidney disease and diabetic nephropathy. AGE inhibitors, such as aminoguanidine and pyridoxamine, have the therapeutic activities for reversing the increase in renal AGE burden. This study evaluated the inhibitory effects of ethyl pyruvate (EP) on methylglyoxal- (MGO-) modified AGE cross-links with proteins in vitro. We also determined the potential activity of EP in reducing the renal AGE burden in exogenously MGO-injected rats. EP inhibited MGO-modified AGE-bovine serum albumin (BSA) cross-links to collagen (IC50=0.19±0.03 mM) in a dose-dependent manner, and its activity was stronger than aminoguanidine (IC50=35.97±0.85 mM). In addition, EP directly trapped MGO (IC50=4.41±0.08 mM) in vitro. In exogenous MGO-injected rats, EP suppressed AGE burden and MGO-induced oxidative injury in renal tissues. These activities of EP on the MGO-mediated AGEs cross-links with protein in vitro and in vivo showed its pharmacological potential for inhibiting AGE-induced renal diseases.

scholarly journals In-Vivo Toxicity Studies and In-Vitro Inactivation of SARS-CoV-2 by Povidone-iodine In-situ Gel Forming Formulations

2020 ◽  
Author(s):  
Bo Liang ◽  
Xudong Yuan ◽  
Gang Wei ◽  
Wei Wang ◽  
Ming Zhang ◽  
...  
Keyword(s):  
Povidone Iodine ◽  
Early Stage ◽  
Etiologic Agent ◽  
Dependent Manner ◽  
Forming Technology ◽  
Long Acting ◽  
Dose Dependent

AbstractTo curb the spread of SARS-CoV-2, the etiologic agent of the COVID-19 pandemic, we characterize the virucidal activity of long-acting Povidone Iodine (PVP-I) compositions developed using an in-situ gel forming technology. The PVP-I gel forming nasal spray (IVIEW-1503) and PVP-I gel forming ophthalmic eye drop (IVIEW-1201) rapidly inactivated SARS-CoV-2, inhibiting the viral infection of VERO76 cells. No toxicity was observed for the PVP-I formulations. Significant inactivation was noted with preincubation of the virus with these PVP-I formulations at the lowest concentrations tested. It has been demonstrated that both PVP-I formulations can inactivate SARS-CoV-2 virus efficiently in both a dose-dependent and a time-dependent manner. These results suggest IVIEW-1503 and IVIEW-1201 could be potential agents to reduce or prevent the transmission of the virus through the nasal cavity and the eye, respectively. Further studies are needed to clinically evaluate these formulations in early-stage COVID-19 patients.

scholarly journals Dual Regulation of c-Myc by p300 via Acetylation-Dependent Control of Myc Protein Turnover and Coactivation of Myc-Induced Transcription

2005 ◽  
Vol 25 (23) ◽  
pp. 10220-10234 ◽  
Author(s):  
Francesco Faiola ◽  
Xiaohui Liu ◽  
Szuying Lo ◽  
Songqin Pan ◽  
Kangling Zhang ◽  
...  
Keyword(s):  
Dna Binding ◽  
Cell Fate ◽  
Mammalian Cells ◽  
Dependent Manner ◽  
Dual Roles ◽  
Human Telomerase Reverse Transcriptase ◽  
Lysine Residues ◽  
Human Telomerase

ABSTRACT The c-Myc oncoprotein (Myc) controls cell fate by regulating gene transcription in association with a DNA-binding partner, Max. While Max lacks a transcription regulatory domain, the N terminus of Myc contains a transcription activation domain (TAD) that recruits cofactor complexes containing the histone acetyltransferases (HATs) GCN5 and Tip60. Here, we report a novel functional interaction between Myc TAD and the p300 coactivator-acetyltransferase. We show that p300 associates with Myc in mammalian cells and in vitro through direct interactions with Myc TAD residues 1 to 110 and acetylates Myc in a TAD-dependent manner in vivo at several lysine residues located between the TAD and DNA-binding domain. Moreover, the Myc:Max complex is differentially acetylated by p300 and GCN5 and is not acetylated by Tip60 in vitro, suggesting distinct functions for these acetyltransferases. Whereas p300 and CBP can stabilize Myc independently of acetylation, p300-mediated acetylation results in increased Myc turnover. In addition, p300 functions as a coactivator that is recruited by Myc to the promoter of the human telomerase reverse transcriptase gene, and p300/CBP stimulates Myc TAD-dependent transcription in a HAT domain-dependent manner. Our results suggest dual roles for p300/CBP in Myc regulation: as a Myc coactivator that stabilizes Myc and as an inducer of Myc instability via direct Myc acetylation.

scholarly journals Dioxin exposure and porcine reproductive hormonal activity

2002 ◽  
Vol 18 (2) ◽  
pp. 453-462 ◽  
Author(s):  
Ewa L. Gregoraszczuk
Keyword(s):  
Corpora Lutea ◽  
Dependent Manner ◽  
Luteal Cells ◽  
Aryl Hydrocarbon ◽  
Preovulatory Follicles ◽  
Activity Of Enzymes ◽  
Primary Monolayer ◽  
Dioxin Exposure

To characterize the action of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during both the follicular and luteal phases of the ovarian cycle, the direct effect of TCDD was investigated in vitro using a system of primary monolayer cell culture. Granulosa and theca cells were collected from the preovulatory follicles and cultured as a co-culture, thus resembling follicles in vivo. Luteal cells were isolated from the corpora lutea collected during the midluteal phase. In both cases cells were isolated from the ovaries of animals exhibiting natural estrus cycle. Results of these experiments suggest that TCDD decreases estradiol secretion by follicular cells and progesterone secretion by luteal cells in a dose-dependent manner. It was also shown that TCDD disrupts steroidogenesis through its influence on the activity of enzymes involved in the steroid biosynthesis cascade. In luteal cells, its action is mediated via the aryl hydrocarbon receptor (AhR) and is probably independent of estrogen receptor (ER) stimulation. Endocrine disruptors that interfere with estradiol production in the follicles can act as ovulatory disruptors, and while interfering with progesterone production by luteal cells they can act as abortifacients.

scholarly journals Fungal cryptochrome with DNA repair activity reveals an early stage in cryptochrome evolution

2015 ◽  
Vol 112 (49) ◽  
pp. 15130-15135 ◽  
Author(s):  
Victor G. Tagua ◽  
Marcell Pausch ◽  
Maike Eckel ◽  
Gabriel Gutiérrez ◽  
Alejandro Miralles-Durán ◽  
...  
Keyword(s):  
Dna Repair ◽  
Blue Light ◽  
Early Stage ◽  
Single Gene ◽  
Dna Lesions ◽  
Pyrimidine Dimer ◽  
Dependent Manner ◽  
Phycomyces Blakesleeanus

DASH (Drosophila, Arabidopsis, Synechocystis, Human)-type cryptochromes (cry-DASH) belong to a family of flavoproteins acting as repair enzymes for UV-B–induced DNA lesions (photolyases) or as UV-A/blue light photoreceptors (cryptochromes). They are present in plants, bacteria, various vertebrates, and fungi and were originally considered as sensory photoreceptors because of their incapability to repair cyclobutane pyrimidine dimer (CPD) lesions in duplex DNA. However, cry-DASH can repair CPDs in single-stranded DNA, but their role in DNA repair in vivo remains to be clarified. The genome of the fungus Phycomyces blakesleeanus contains a single gene for a protein of the cryptochrome/photolyase family (CPF) encoding a cry-DASH, cryA, despite its ability to photoreactivate. Here, we show that cryA expression is induced by blue light in a Mad complex-dependent manner. Moreover, we demonstrate that CryA is capable of binding flavin (FAD) and methenyltetrahydrofolate (MTHF), fully complements the Escherichia coli photolyase mutant and repairs in vitro CPD lesions in single-stranded and double-stranded DNA with the same efficiency. These results support a role for Phycomyces cry-DASH as a photolyase and suggest a similar role for cry-DASH in mucoromycotina fungi.

Glycation With Fructose: The Bitter Side of Nature’s Own Sweetener

2020 ◽  
Vol 16 (9) ◽  
pp. 962-970 ◽  
Author(s):  
Samreen Amani ◽  
Shamila Fatima
Keyword(s):  
Peripheral Nerves ◽  
Large Scale ◽  
Reducing Sugars ◽  
Polyol Pathway ◽  
The Body ◽  
High Fructose ◽  
Glycation End Products ◽  
Schiff Base Formation ◽  
Base Formation

: Fructose is a ketohexose and sweetest among all the natural sugars. Like other reducing sugars, it reacts readily with the amino- and nucleophilic groups of proteins, nucleic acids and other biomolecules resulting in glycation reactions. The non-enzymatic glycation reactions comprise Schiff base formation, their Amadori rearrangement followed by complex and partly incompletely understood reactions culminating in the formation of Advance Glycation End products (AGEs). The AGEs are implicated in complications associated with diabetes, cardiovascular disorders, Parkinson’s disease, etc. : Fructose is highly reactive and forms glycation products that differ both in structure and reactivity as compared to those formed from glucose. Nearly all tissues of higher organisms utilize fructose but only a few like the ocular lens, peripheral nerves erythrocytes and testis have polyol pathway active for the synthesis of fructose. Fructose levels rarely exceed those of glucose but, in tissues that operate the polyol pathway, its concentration may rise remarkably during diabetes and related disorders. Diet contributes significantly to the body fructose levels however, availability of technologies for the large scale and inexpensive production of fructose, popularity of high fructose syrups as well as the promotion of vegetarianism have resulted in a remarkable increase in the consumption of fructose. In vivo glycation reactions by fructose, therefore, assume remarkable significance. The review, therefore, aims to highlight the uniqueness of glycation reactions with fructose and its role in some pathophysiological situations.

scholarly journals Lysosome restoration to activate podocyte autophagy: a new therapeutic strategy for diabetic kidney disease

2019 ◽  
Vol 10 (11) ◽  
Author(s):  
Wei Jing Liu ◽  
Yu Gan ◽  
Wei Fang Huang ◽  
Hong-luan Wu ◽  
Xue-qin Zhang ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Diabetic Kidney Disease ◽  
Degradation Process ◽  
Beclin 1 ◽  
Dependent Manner ◽  
Lysosomal Function ◽  
Diabetic Kidney ◽  
Glycation End Products

Abstract Autophagy, the intracellular lysosomal degradation process plays a pivotal role in podocyte homeostasis in diabetic kidney disease (DKD). Lysosomal function, autophagic activity, and their actions were investigated in vitro and in vivo. We found that LC3-II- and p62-positive vacuoles accumulated in podocytes of patients with DKD. Moreover, we found that advanced glycation end products (AGEs) could increase the protein expression of LC3-II and p62 in a dose- and time-dependent manner in cultured podocytes. However, the mRNA expression of LC3B, Beclin-1 or ATG7, as well as the protein level of Beclin-1 or ATG7 did not change significantly in the AGE-treated cells compared with that in control groups, suggesting that AGEs did not induce autophagy. In addition, AGEs led to an increase in the number of autophagosomes but not autolysosomes, accompanied with a failure in lysosomal turnover of LC3-II or p62, indicating that the degradation of autophagic vacuoles was blocked. Furthermore, we observed a dramatic decrease in the enzymatic activities, and the degradation of DQ-ovalbumin was significantly suppressed after podocytes were treated with AGEs. Plasma-irregular lysosomal-associated membrane protein 1 granules accompanied with the diffusion of cathepsin D expression and acridine orange redistribution were observed in AGE-treated podocytes, indicating that the lysosomal membrane permeability was triggered. Interestingly, we also found that AGEs-induced autophagic inhibition and podocyte injury were mimicked by the specific lysosomotropic agent, l-leucyl-l-leucine methyl ester. The exacerbated apoptosis and Rac-1-dependent actin-cytoskeletal disorganization were alleviated by an improvement in the lysosomal-dependent autophagic pathway by resveratrol plus vitamin E treatment in AGE-treated podocytes. However, the rescued effects were reversed by the addition of leupeptin, a lysosomal inhibitor. It suggests that restoring lysosomal function to activate autophagy may contribute to the development of new therapeutic strategies for DKD.

scholarly journals Inhibition of Cytomegalovirus Replication with Extended-Half-Life Synthetic Ozonides

2018 ◽  
Vol 63 (1) ◽  
Author(s):  
Yiping Wang ◽  
Rupkatha Mukhopadhyay ◽  
Sujayita Roy ◽  
Arun Kapoor ◽  
Yu-Pin Su ◽  
...  
Keyword(s):  
Half Life ◽  
Cell Cycle Progression ◽  
Early Stage ◽  
Human Fibroblasts ◽  
Dependent Manner ◽  
Therapeutic Success ◽  
Concentration Dependent Manner ◽  
Malaria Therapy

ABSTRACTArtesunate (AS), a semisynthetic artemisinin approved for malaria therapy, inhibits human cytomegalovirus (HCMV) replicationin vitro, but therapeutic success in humans has been variable. We hypothesized that the shortin vivohalf-life of AS may contribute to the different treatment outcomes. We tested novel synthetic ozonides with longer half-lives against HCMVin vitroand mouse cytomegalovirus (MCMV)in vivo. Screening of the activities of four ozonides against a pp28-luciferase-expressing HCMV Towne recombinant identified OZ418 to have the best selectivity; its effective concentration inhibiting viral growth by 50% (EC50) was 9.8 ± 0.2 µM, and cytotoxicity in noninfected human fibroblasts (the concentration inhibiting cell growth by 50% [CC50]) was 128.1 ± 8.0 µM. In plaque reduction assays, OZ418 inhibited HCMV TB40 in a concentration-dependent manner as well as a ganciclovir (GCV)-resistant HCMV isolate. The combination of OZ418 and GCV was synergistic in HCMV inhibitionin vitro. Virus inhibition by OZ418 occurred at an early stage and was dependent on the cell density at the time of infection. OZ418 treatment reversed HCMV-mediated cell cycle progression and correlated with the reduction of HCMV-induced expression of pRb, E2F1, and cyclin-dependent kinases 1, 2, 4, and 6. In an MCMV model, once-daily oral administration of OZ418 had significantly improved efficacy against MCMV compared to that of twice-daily oral AS. A parallel pharmacokinetic study with a single oral dose of OZ418 or AS showed a prolonged plasma half-life and higher unbound concentrations of OZ418 than unbound concentrations of AS. In summary, ozonides are proposed to be potential therapeutics, alone or in combination with GCV, for HCMV infection in humans.

scholarly journals Antiglycation Activity of Aucubin In Vitro and in Exogenous Methylglyoxal Injected Rats

Molecules ◽  
2019 ◽  
Vol 24 (20) ◽  
pp. 3653 ◽  
Author(s):  
Eunsoo Jung ◽  
Su-Bin Park ◽  
Woo Kwon Jung ◽  
Hyung Rae Kim ◽  
Junghyun Kim
Keyword(s):  
Chronic Diseases ◽  
Causative Factor ◽  
Dependent Manner ◽  
Glycation End Products ◽  
Cross Links ◽  
Potential Activity ◽  
Pharmacological Potential ◽  
Therapeutic Activities

Advanced glycation end products (AGEs) is a causative factor of various chronic diseases, including chronic kidney disease and atherosclerosis. AGE inhibitors, such as aminoguanidine and pyridoxamine, have the therapeutic activities for reversing the increase in AGEs burden. This study evaluated the inhibitory effects of aucubin on the formation of methylglyoxal (MGO)-modified AGEs in vitro. We also determined the potential activity of aucubin in reducing the AGEs burden in the kidney, blood vessel, heart, and retina of exogenously MGO-injected rats. Aucubin inhibited the formation of MGO-modified AGE-bovine serum albumin (IC50 = 0.57 ± 0.04 mmol/L) and its cross-links to collagen (IC50 = 0.55 ± 0.02 mmol/L) in a dose-dependent manner. In addition, aucubin directly trapped MGO (IC50 = 0.22 ± 0.01 mmol/L) in vitro. In exogenous MGO-injected rats, aucubin suppressed the formation of circulating AGEs and its accumulation in various tissues. These activities of aucubin on the MGO-derived AGEs in vitro and in vivo showed its pharmacological potential for inhibiting AGEs-related various chronic diseases.

scholarly journals Aminoguanidine inhibits advanced glycation end products formation on beta2-microglobulin.

1998 ◽  
Vol 9 (2) ◽  
pp. 277-283
Author(s):  
F F Hou ◽  
J Boyce ◽  
G M Chertow ◽  
J Kay ◽  
W F Owen
Keyword(s):  
Advanced Glycation End Products ◽  
Keyhole Limpet Hemocyanin ◽  
Enzyme Linked Immunosorbent Assay ◽  
Dependent Manner ◽  
Advanced Glycation ◽  
Molar Ratios ◽  
Glycation End Products ◽  
End Products

Because advanced glycation end products (AGE)-modified beta2-microglobulin (AGE-beta2M) is a dominant constituent of amyloid in dialysis-related amyloidosis (DRA), AGE-beta2M may be directly involved in the pathobiology of DRA. In experimental diabetes mellitus, blocking the formation of AGE prevents AGE-mediated tissue damage. In this study, it is postulated that similar pharmacologic intervention may be beneficial in DRA. Aminoguanidine, a nucleophilic hydrazine compound that prevents AGE formation on collagen, may have a similar effect on the advanced glycation of beta2M. To test this hypothesis, beta2M was incubated in vitro with 50 or 100 mM D-glucose for 3 wk in the presence and absence of incremental concentrations of aminoguanidine. On the basis of enzyme-linked immunosorbent assay and immunoblots using anti-AGE-keyhole limpet hemocyanin antibody, aminoguanidine inhibited glucose-induced N(epsilon)-(carboxymethyl)lysine formation on beta2M. At aminoguanidine-glucose molar ratios of 1:8 to 1:1, 26 to 53% inhibition occurred. Fluorospectrometry examination showed that aminoguanidine also inhibited the formation of fluorescent AGE on beta2M in a dose-dependent manner. At aminoguanidine-glucose molar ratios of 1:8 to 1:1, fluorescent product generation was inhibited by 30 to 70%. Furthermore, aminoguanidine suppressed the AGE formation on beta2M bound to AGE-modified collagen. If aminoguanidine is similarly active in vivo, this compound may be of clinical utility for treating DRA in patients on maintenance dialysis.

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