Sulfamethizole attenuates poloxamer 407-induced atherosclerotic neointima formation via inhibition of mTOR in C57BL/6 mice

Mammalian target of Rapamycin C1 (mTORC1) inhibition limits plaque progression in atherosclerosis. The present study evaluated the protective effect of sulfamethizole on poloxamer 407-induced atherosclerotic neointima formation in C57BL/6 mice via mTOR inhibition. Poloxamer 407 (P-407) (0.5 g/kg body weight) was administered intraperitoneally to male C57BL/6 mice every third day for 148 days to induce chronic hyperlipidemia. From Day 121 to 148, animals were additionally administered Sulfamethizole (5, 10, and 50 mg/kg, p.o.), Rapamycin (0.5 mg/kg, positive control), or vehicle (1 ml/kg). Plasma lipid levels were measured on Days 120 and 148. Upon sacrifice, histological studies were performed, and aortic tissue interleukin (IL)-6, tumor necrosis factor-α (TNF-α), and mTOR levels were evaluated. A molecular docking study was carried out to mimic the interaction of sulfamethizole with mTOR protein. Chronic P-407 administration significantly (p < 0.001) elevated plasma lipid levels, compared with those of the normal control group. Chronic hyperlipidemia resulted in increased tunica intima thickness, collagen deposition, and IL-6, TNF-α, and mTOR levels. Treatment with Sulfamethizole attenuated these parameters significantly in a dose-dependent manner. Molecular docking studies showed a significant interaction of Sulfamethizole with mTOR. In conclusion, this study suggests that sulfamethizole significantly limits poloxamer 407-induced atherosclerotic neointima formation in C57BL/6 mice via mTOR inhibition.     

Binding and precipitating activities ofErythrina lectins with complex type carbohydrates and synthetic cluster glycosides. A comparative study of the lectins fromE. corallodendron,E. cristagalli,E. flabelliformis,andE. indica

Erythrina lectins possess similar structural and carbohydrate binding properties. Recently, tri- and tetra-antennary complex type carbohydrates with non-reducing terminal galactose residues have been shown to be precipitated as tri- and tetravalent ligands, respectively, with certainErythrina lectins [Bhattacharyya L, Haraldsson M, Brewer CF (1988) Biochemistry 271034-41]. The present work describes a comparative study of the binding and precipitating activities of fourErythrina lectins,viz. E. corallodendron, E. cristagalli, E. flabelliformis, andE. indica, with multi-antennary complex type carbohydrates and synthetic cluster glycosides. The results show that though their binding affinities are very similar, theErythrina lectins show large differences in their precipitating activities with the carbohydrates. The results also indicate significant dependence of the precipitating activities of the lectins on the core structure of the carbohydrates. These findings provide a new dimension to the structure-activity relationship of the lectins and their interactions with asparagine-linked carbohydrates.Abbreviations EAL, ECorL, ECL, EFL, and EIL represent the lectins from the seeds ofErythrina arborescens, - E. corallodendron, E. cristagalli, E. flabelliformis, andE. indica respectively - AFOS thetri-antennary complex type oligosaccharide from asialofetuin - AFGP the tri-antennary glycopeptide from asialofetuin - MeGal methyl -d-galactopyranoside Unless stated otherwise all sugars are in thed-configuration.     

Effect of cytokines on polymorphonuclear neutrophil infiltration in the mouse. Prostaglandin- and leukotriene-independent induction of infiltration by IL-1 and tumor necrosis factor

The i.p. injection of mice with highly purified recombinant human rIL-1 alpha or beta resulted in the rapid influx of a large number of polymorphonuclear neutrophils (PMN) into the peritoneal cavity. Significant increases in the number of PMN were induced by doses of IL-1 which ranged from 0.005 to 5 ng/injection. Interestingly the dose response for PMN influx was bell-shaped because 50 ng of IL-1 did not result in a significant increase in peritoneal PMN. IL-1 induced PMN infiltration was detectable by 1 h with peak levels of PMN obtained by about 2 h, followed by a subsequent decline by 24 h. Other cytokines, IL-2, IFN-gamma, IFN alpha beta, granulocyte-CSF, granulocyte-macrophage-CSF, IL-3, TNF-alpha, and TNF-beta were compared to IL-1 for their ability to induce a PMN influx into the peritoneum. Only TNF-alpha or TNF-beta (lymphotoxin) were able to induce a significant influx of PMN within 2 h. However, based on total protein administered, about 100 times more TNF than IL-1 was required to produce a comparable PMN infiltration. Intraperitoneal injection of inhibitors of the cyclooxygenase or lipoxygenase pathways did not inhibit the IL-1-induced influx of PMN. Also, neither IL-1 nor TNF triggered an increase in PG or leukotriene release from peritoneal cells in vitro. Furthermore, direct peritoneal injection of leukotriene B4, a potent PMN chemoattractant in vitro, did not induce any significant increase in PMN in the peritoneal cavity indicating that chemotactic activity alone is insufficient for inducing peritoneal infiltration. These results suggest that the local production of very low levels of IL-1 in vivo would be sufficient to initiate a sequence of events that results in a rapid accumulation of PMN. Because IL-1 was not chemotactic for PMN in vitro, our data suggest that IL-1 induces production of factors that are chemotactic for PMN. Alternatively, IL-1 may act on other stages of the complex sequence of events that regulates the emigration of PMN into tissue sites in vivo. The synergy apparent in PMN influx when suboptimal concentrations of IL-1 and TNF were injected suggests that the local production of very low concentrations of these cytokines in situ could play a critical role in the emigration of PMN during infection.     

Intracellular calcium does not appear to be essential for arachidonic acid release from stimulated macrophages as shown by studies with Quin-2

The present investigation was undertaken to study the potential role of intracellular calcium on the release of arachidonic acid from mouse peritoneal macrophages activated by inflammatory stimuli. The intracellular calcium concentration, as measured using fluorescent probe Quin-2, was 112 +/- 8.4 nM. The chelation of intracellular calcium with Quin-2 did not affect the release of arachidonic acid from macrophages upon stimulation with phorbol myristate acetate, opsonized zymosan or calcium ionophore A23187. However, the removal of calcium from the extracellular medium resulted in a 30-50% decrease in arachidonic acid release from phorbol myristate acetate- and zymosan-stimulated macrophages and also the stimulation of arachidonic acid release from calcium ionophore-stimulated cells were nullified. These studies indicated the existence of calcium-dependent and independent mechanisms modulating the release of arachidonic acid from macrophages subjected to inflammatory stimuli.     

Phospholipid fatty acid modification of rat liver microsomes affects acylcoenzyme A:cholesterol acyltransferase activity

The effect of phospholipid fatty acyl composition on the activity of acylcoenzyme A:cholesterol acyltransferase was investigated in rat liver microsomes. Specific phosphatidylcholine replacements were produced by incubating the microsomes with liposomes and bovine liver phospholipid-exchange protein. Although the fatty acid composition of the microsomes was modified appreciably, there was no change in the microsomal phospholipid or cholesterol content. As compared to microsomes enriched for 2 h with dioleoylphosphatidylcholine, those enriched with dipalmitoylphosphatidylcholine exhibited 30-45% less acyl-CoA:cholesterol acyltransferase activity. Enrichment with 1-palmitoyl-2-linoleoylphosphatidylcholine increased acyl-CoA:cholesterol acyltransferase activity by 20%. By contrast, dilinoleoylphosphatidylcholine abolished microsomal acyl-CoA:cholesterol acyltransferase activity almost completely. Addition of cofactors that stimulated microsomal lipid peroxidation inhibited acyl-CoA:cholesterol acyltransferase activity by only 10%, however, and did not increase the inhibition produced by submaximal amounts of dilinoleoylphosphatidylcholine. Certain of the phosphatidylcholine replacements produced changes in palmitoyl-CoA hydrolase, NADPH-dependent lipid peroxidase, glucose-6-phosphatase and UDPglucuronyl transferase activities, but they did not closely correlate with the alterations in acyl-CoA:cholesterol acyltransferase activity. Electron spin resonance measurements with the 5-nitroxystearate probe indicated that microsomal lipid ordering was reduced to a roughly similar extent by dioleoyl- or by dilinoleoylphosphatidylcholine enrichment. Since these enrichments produce widely different effects on acyl-CoA:cholesterol acyltransferase activity, changes in bulk membrane lipid fluidity cannot be the only factor responsible for phospholipid fatty acid compositional effect on acyl-CoA:cholesterol acyltransferase. The present results are more consistent with a modulation resulting from either changes in the lipid microenvironment of acyl-CoA:cholesterol acyltransferase or a direct interaction between specific phosphatidylcholine fatty acyl groups and acyl-CoA:cholesterol acyltransferase.     

Purification and properties of d-galactose-binding lectins from some erythrina species: Comparison of properties of lectins from E. indica,E. arborescens,E. suberosa, and E. lithosperma

The lectins of the seeds of four species of the genus Erythrina, namely E. indica, E. arborescens, E. lithosperma, and E. suberosa were isolated by affinity chromatography on acid-treated ECD-Sepharose 6B. The lectins were found homogeneous in polyacrylamide gel electrophoresis and immunochemical tests. In SDS-gel electrophoresis, E. indica and E. lithosperma lectins each gave two bands with subunit molecular weights of 30,000 and 33,000 in the case of the former and 26,000 and 28,000 in the case of the latter. E. arborescens and E. suberosa gave single bands corresponding to polypetide chain molecular weight of 28,000. The lectins were found to be glycoproteins with their neutral sugar contents ranging from 4–9%. In carbohydrate specificity all the lectins were d-galactose specific. Their close similarity was also demonstrated by their homologous cross-reaction against the antiserum to E. indica lectin. In hemagglutinating activity toward human erythrocytes, E. indica and E. suberosa lectins showed higher activity toward the O group and E. arborescens toward the B group. The results show the similarity of the lectins derived from different species of the same genus in respect of immunochemical properties and carbohydrate specificity. In studies on E. indica lectin, the protein was found homogeneous by electrophoretic, immunochemical, and sedimentation experiments. Its molecular weight of 68,000 determined from sedimentation and diffusion data indicated that the molecule was a dimer of two noncovalently bound unequal subunits whose SDS-gel electrophoretic molecular weights are noted above. The lectin was devoid of cysteine and methionine and contained valine as its N-terminal amino acid. It had 9% neutral sugars and 1.5% glucosamine. Equilibrium dialysis studies with lactose showed that the values of the association constant K at different temperatures were of similar orders of magnitude to other lectins and the dimeric molecule possessed two noninteracting binding sites.     

Solvent-Free Synthesis,Characterization, and In Vitro Biological Activity Study of Xanthenediones and Acridinediones

Russian Journal of Bioorganic Chemistry - The present work highlights the broad range of oxygen and nitrogen heterocycles and their applications in medicinal field. A facial approach has been...     

Effect of hot water and ultra violet radiation on the incidence of seedborne fungi of okra

Seed samples of okra (Abelmoschus esculentus (L.) Moench) variety Arka anamika were subjected to hot water treatment at 42, 52 and 62°C for a period of 30 min and UV light treatment for 10, 20, 30 min at 28 ± 2°C. Their efficacy was tested against some seedborne fungal species. Among them, seeds under hot water treatment at 52°C for 30 min and UV light at 20 min were found to be more effective in the improvement of crop, both in greenhouse and field conditions. Ultimately, there was increase in the total number of leaves, fruits, length of the fruit, girth and biomass of the plants. Apart from these the total number of seeds per fruit, 1000 seed weight and ascorbic acid content were also found to be enhanced. These treatments also reduced the incidence of mycoflora in the seeds and thereby enhanced the seed germination percentage and vigour index of the seedlings.     

Interaction of Aryl Hydrocarbon Receptor-interacting Protein-like 1 with the Farnesyl Moiety

Aryl hydrocarbon receptor-interacting protein-like 1 (AIPL1) is a photoreceptor specific chaperone of the visual effector enzyme phosphodiesterase-6 (PDE6). AIPL1 has been shown to bind the farnesylated PDE6A subunit. Mutations in AIPL1 are thought to destabilize PDE6 and thereby cause Leber congenital amaurosis type 4 (LCA4), a severe form of childhood blindness. Here, we examined the solution structure of AIPL1 by small angle x-ray scattering. A structural model of AIPL1 with the best fit to the scattering data features two independent FK506-binding protein (FKBP)-like and tetratricopeptide repeat domains. Guided by the model, we tested the hypothesis that AIPL1 directly binds the farnesyl moiety. Our studies revealed high affinity binding of the farnesylated-Cys probe to the FKBP-like domain of AIPL1, thus uncovering a novel function of this domain. Mutational analysis of the potential farnesyl-binding sites on AIPL1 identified two critical residues, Cys-89 and Leu-147, located in close proximity in the structure model. The L147A mutation and the LCA-linked C89R mutation prevented the binding of the farnesyl-Cys probe to AIPL1. Furthermore, Cys-89 and Leu-147 flank the unique insert region of AIPL1, deletion of which also abolished the farnesyl interaction. Our results suggest that the binding of PDE6A farnesyl is essential to normal function of AIPL1 and its disruption is one of the mechanisms underlying LCA.     

The anhydrous milk fat, ghee, lowers serum prostaglandins and secretion of leukotrienes by rat peritoneal macrophages

Ghee, the anhydrous milk fat, is one of the most important sources of dietary fat in India. Male Wistar rats were fed diets containing 2.5, 5.0 and 10 wt% ghee for a period of 8 weeks. The diets were made isocaloric with groundnut oil. The results showed that serum thromboxane levels decreased by 27-35%, and 6-keto-prostaglandin F1alpha by 23-37% when ghee was incorporated at level of 10% in the diet. Prostaglandin E2 levels in serum and secretion of leukotrienes B4, C4 and D4 by peritoneal macrophages activated with calcium ionophore decreased when increased amounts of ghee from 2.5 to 10% were included in the diet. Arachidonic acid levels in macrophage phospholipids decreased when incremental amounts of ghee were fed to rats. These studies indicate that ghee in the diet not only lowers the prostaglandin levels in serum but also decreases the secretion of leukotrienes by macrophages.