NOPR Collection: [Pages 433-502]

Regulation of NO production by MAPK dual-specificity phosphatases (DUSP) in human neutrophils exposed to N-nitrosodimethylamine

Wed, 01 Jul 2020 00:00:00 GMT

Title: Regulation of NO production by MAPK dual-specificity phosphatases (DUSP) in human neutrophils exposed to N-nitrosodimethylamine Authors: Ratajczak-Wrona, Wioletta; Jablonska, Ewa; Garley, Marzena; Nowak, Karolina; Dabrowska, Dorota; Radziwon, Piotr Abstract: One of the enzymes responsible for nitric oxide (NO) production in neutrophils is the inducible nitric oxide synthase (iNOS). Changes in its expression may result from the activation of different signaling pathways, including MAPK, which lead to activation of various genes, including DUSP genes. DUSP induce the negative feedback loop leading to MAPK deactivation through their phosphorylation. Our study assessed the role of DUSP1, DUSP10 and DUSP16 with the participation of MAPK in the iNOS-dependent NO production by neutrophils exposed to xenobiotic, N-nitrosodimethylamine (NDMA). The obtained results suggest that N-nitrosodimethylamine enhances the expression of all tested proteins (except DUSP10) in the cytoplasmic and nuclear fractions of neutrophils. The JNK pathway inhibition resulted in an extenuation of iNOS, phospho-p38 and DUSP10 expression in the cytoplasmic fraction and DUSP1 expression in the nuclear fraction of neutrophils. Inhibition of the p38 pathway led to a lower expression of iNOS, DUSP16 and DUSP10 in the cytoplasmic fraction. No changes in the phospho-JNK and DUSP1 expressions were observed. With the results of this study we can conclude that DUSP are positive regulators of MAP kinases in NDMA-induced signaling pathway which lead to modulation of iNOS-dependent NO production in human neutrophils. Page(s): 437-444

In vitro anticariogenic effect of gallic acid against Streptococcus mutans

Wed, 01 Jul 2020 00:00:00 GMT

Title: In vitro anticariogenic effect of gallic acid against Streptococcus mutans Authors: Goyal, Dimple; Rather, Shabeer A.; Sharma, Sukesh Chander; Mahmood, Akhtar Abstract: Involvement of Streptococcus mutans in the pathogenesis of dental caries among human populations is well established. Here, we studied the effect of gallic acid, a naturally occurring polyphenol on certain cariogenic activities of S. mutans. Gallic acid inhibited the glycosyltransferase activity, a key enzyme of sucrose metabolism by 27-36% in S. mutans. Minimal inhibitory concentration (MIC) of gallic acid (136 μg/mL) inhibited the growth of S.mutans by 50%. About 0.4 mM of the polyphenol reduced biofilm formation by 40%, hydrophobicity 60% and acid production 36% by the organism under in vitro growth conditions. Fluorescence microscopy revealed that in absence of gallic acid, the cells were present as clumps, however in the presence of gallic acid (68 µg/mL), they were well segregated due to the inhibition of biofilm formation. The present findings suggest that gallic acid has cariostatic activity against S. mutans, which may have potential application in prevention of dental caries. Page(s): 445-451

Garlic ameliorates long-term pre-diabetes induced retinal abnormalities in high fructose fed rat model

Wed, 01 Jul 2020 00:00:00 GMT

Title: Garlic ameliorates long-term pre-diabetes induced retinal abnormalities in high fructose fed rat model Authors: Kommula, Sivakesava Rao; Chekkilla, Uday Kumar; Ganugula, Raghu; Patil, Madhoosudan Anant; Vadakattu, Sai Santhosh; Myadara, Srinivas; Putcha, Uday Kumar; Ramavat, Ravindar Naik; Ponday, Laxmi Rajkumar; Tamana, Raghava Rao; Palla, Suryanarayana Abstract: Retinopathy is one of the micro vascular complications of diabetes and can also be observed in pre-diabetic state. However, there are only limited studies available on the pathophysiology of retinopathy in pre-diabetic state and its preventive strategies. In this study, we investigated the retinal functional, structural and molecular alterations using high fructose (HF) induced pre-diabetic rat model and also the protective role of garlic. Feeding of HF to Wistar NIN (WNIN) rats had developed insulin resistance (IR) and impaired glucose tolerance (IGT) by three months, while retinal functional abnormalities by ten months as evidenced by decrease of Electroretinogram (ERG) scotopic, photopic b-wave amplitudes, oscillatory potentials (OPs) when compared to controls. Supplementation of garlic (3%) to HF+G group rats had marginally protected these changes. Elevated expression of glial fibrillary acidic protein (GFAP), vascular endothelial growth factor (VEGF), aldose reductase (AR) and decreased rhodopsin (Rho) in HF group rats as evidenced by immunehistochemistry, immunoblot methods, which were further supported by gene expression studies, indicate the initiation of retinal abnormalities. Increased immune-fluorescence signal of carboxymethyl lysine (CML-KLH) and 4-hydroxynanoenol (4-HNE) in retina of HF group rats indicate the association of glycation and oxidative stress, respectively. Early intervention of garlic to HF+G group rats attenuated retinal functional, structural, and molecular abnormalities. Page(s): 452-460

Isolation and characterization of yeast strains from Badacsony, Hungary

Wed, 01 Jul 2020 00:00:00 GMT

Title: Isolation and characterization of yeast strains from Badacsony, Hungary Authors: Gerőcs, Annamária; Nemes-Barnás, Katalin; Pál, Sára; Szőke, Barna; Májer, János; Farkas, Tibor; Olasz, Ferenc Abstract: In modern winery, starter strains are used for wine making to avoid the risk of slow or incomplete fermentation. However, application of commercial starter yeasts sometimes leads to a uniform character of the wines. On the other hand, indigenous (“terroir”) strains are adapted better to local conditions highlighting the specific taste of wine. In this study, we isolated local yeast strains from Badacsony wine region of Hungary and investigated with microbiological and molecular biological tests in order to develop indigenous starter selection method. As many as 480 yeast strains were isolated and grouped using carbohydrate and nitrogen sources. Finally, 80 selected isolates were characterized for important oenological features, including tolerance of glucose, ethanol and acetic acid. Fermentation ability, killer toxin, hydrogen sulfide and acid production of 80 selected isolates were also tested. Isolates were studied by applying two molecular methods based on rRNA gene sequencing and analysis of Ty retrotransposon's delta elements in case of Saccharomyces strains. Our results have shown that the isolated strains belong to 15 yeast species of 8 genera, and the diversity of yeast population was significantly high in the investigated vineyard. We have found that selection for technological properties was a potential way to find suitable strains from the local microbiome, because a high proportion of isolated wild yeast strains show beneficial oenological properties for wine making. Further, we studied 35 available starter yeasts to avoid re-isolation and we identified only 3 starter yeasts from grape and must samples, which can be considered as very low incidence. Page(s): 461-473