Xylanase and Mannanase enzymes from Streptomyces galbus NR and their use in biobleaching of softwood kraft pulp

Enzymatic pretreatment of softwood kraft pulp was investigated using xylanase and mannanase, singly or in combination, either sequentially or simultaneously. Enzymes were obtained from Streptomyces galbus NR that had been cultivated in a medium, containing either xylan of sugar cane bagasse or galactomannan of palm-seeds, when they were used as sole carbon sources from local wastes in fermentation media. No cellulase activity was detected. Incubation period, temperature, initial pH values and nature of nutritive constituents were investigated. Optimum production of both enzymes was achieved after 5 days incubation on a rotary shaker (200 rpm) at 35 degrees C and initial pH 7.0. Partial purification of xylanase and mannanase in the cultures supernatant were achieved by salting out at 40-60 and 60-80% ammonium sulphate saturation with a purification of 9.63- and 8.71-fold and 68.80 and 62.79% recovery, respectively. The xylanase and mannanase from S. galbus NR have optimal activity at 50 and 40 degrees C, respectively. Both enzymes were stable at a temperature up to 50 degrees C. Xylanase and mannanase showed highest activity at pH 6.5 and were stable from 5.0 to 8.0 and from 5.5 to 7.5, respectively. The partial purified enzymes preparations of xylanase and mannanase enzymes showed high bleaching activity, which is an important consideration for industry. Xylanase was found to be more effective for paper-bleaching than mannanase. When xylanase and mannanase were dosed together (simultaneously), both enzymes were able to enhance the liberation of reducing sugars and improve pulp bleachability, possibly as a result of nearly additive interactions. The simultaneous addition of both enzymes was more effective in pulp treatment than their sequential addition.     

mda-7/IL-24 differentially regulates soluble and nuclear clusterin in prostate cancer

Melanoma differentiation-associated gene-7/interleukin-24 (mda-7/IL-24), a unique member of the IL-10 gene family, displays a broad range of antitumor properties including cancer-specific induction of apoptosis, inhibition of tumor angiogenesis, and modulation of anti-tumor immune responses. Here, we identify clusterin (CLU) as a MDA-7/IL-24 interacting protein in DU-145 cells and investigate the role of MDA-7/IL-24 in regulating CLU expression and mediating the antitumor properties of mda-7/IL-24 in prostate cancer. Ad.mda-7 decreased expression of soluble CLU (sCLU) and increased expression of nuclear CLU (nCLU). In the initial phase of Ad.mda-7 infection sCLU expression increased and CLU interacted with MDA-7/IL-24 producing a cytoprotective effect. Infection of stable clones of DU-145 prostate cancer cells expressing sCLU with Ad.mda-7 resulted in generation of nCLU that correlated with decreased cell viability and increased apoptosis. In the presence of mda-7/IL-24, sCLU-DU-145 cells displayed G(2)/M phase arrest followed by apoptosis. Similarly, Ad.mda-7 infection decreased cell migration by altering cytoskeleton in sCLU-DU-145 cells. Ad.mda-7-treated sCLU-DU-145 cells displayed a significant reduction in tumor growth in mouse xenograft models and reduced angiogenesis when compared to the vector control group. Tumor tissue lysates demonstrated enhanced nCLU generated from sCLU with increased apoptosis in the presence of MDA-7/IL-24. Our findings reveal novel aspects relative to the role of sCLU/nCLU in regulating the anticancer properties of MDA-7/IL-24 that may be exploited for developing enhanced therapies for prostate cancer.     

Physiological and biochemical changes in different sugar beet genotypes infected with root-knot nematode

Ten genotypes of sugar beet plant either monogerm or multigerm seeds were screened under greenhouse conditions for both susceptibility and biochemical reaction to root-knot nematode (RKN) Meloidogyne incognita. All the tested genotypes were susceptible to nematode infection according to the number of root galls and gall indices. All infected genotypes exhibited significant reduction in chlorophyll a, b and carotenoids compared to non-infected ones. The total indole acetic acid and total phenolic compounds contents (mean of both shoot and root) increased significantly in most infected genotypes compared to non-infected genotypes except Disk-01-99 and Monte Rosa as well as LP16 and LP15 genotypes, respectively. Also, total polyamine contents (putrescine, spermidine and spermine) showed significant increases in response to infection with nematodes in all genotypes. The same trend was observed in lipid peroxidation expressed with malondialdehyde content in all tested genotypes. Activities of polyphenol oxidase, peroxidase, superoxide dismutase and catalase enzymes were also induced in most infected genotypes compared with non-infected genotypes. Generally, infection with RKNs induced the appearance of new protein bands at molecular masses 303, 288, 42 and 37?KDa in all infected genotypes. The differentiation in the appearance and/or disappearance of protein bands according to susceptibility to infection reflects the variation between genotypes in defense against infection.     

Anticancer effect of atorvastatin nanostructured polymeric micelles based on stearyl-grafted chitosan

The purpose of this study was to develop a new therapeutic approach for atorvastatin (ATV) adopting nanostructured polymeric micelles for its controlled delivery to the cancer cells. Amphiphilic block copolymers of stearyl chitosan (SC) and sulfated stearyl chitosan (S-SC) that could self assemble to form polymeric micelles with different degree of substitution (DS) were synthesized and characterized. The synthesized chitosan derivatives were able to self assemble and form micelles encapsulating ATV with critical micellar concentrations ranging from 6.9 to 21μg/ml, drug-loading ranging from 40% to 84.1% and encapsulation efficiency ranging from 10.4% to 35%. ATV caused a significant decrease in particle size and zeta potential of both SC and S-SC micelles. Micelles encapsulating ATV exhibited a sustained release and more cytotoxic activity against MCF 7 and HCT 116 cell lines than ATV alone. The 50% cellular growth inhibition (IC50%) of the drug decreased from 10.4 to 3.7 in case of MCF 7 and from 9.4 to 3.4 in case of HCT 116 after its loading in micelles. These results indicate that SC ATV polymeric micelles can be considered as a promising system for site specific controlled delivery of ATV to tumor cells.     

The Association of Cysteine with Obesity, Inflammatory Cytokines and Insulin Resistance in Hispanic Children and Adolescents

Context

Plasma total cysteine (tCys) independently relates to fat mass in adults. Dietary cyst(e)ine promotes adiposity and decreases glucose tolerance in some rodent models, but alleviates insulin resistance in others.

Objective

To investigate whether the association of tCys with body fat extends to children at particular risk of obesity, and whether tCys is associated with insulin resistance and obesity-associated inflammation.

Methods

We explored the cross-sectional relations of fasting plasma tCys and related metabolites with body composition measured by dual-energy X-ray absorptiometry in 984 Hispanic children and adolescents aged 4–19 years from the Viva La Familia Study. Linear and logistic regression and dose-response curves were used to evaluate relations of tCys with obesity, insulin resistance and inflammatory markers including interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1) and C-reactive protein (CRP).

Results

tCys, methionine and total homocysteine (tHcy) increased with age. Upper tCys quartile was independently associated with a 5-fold increased risk of obesity (95% CI 3.5–8.0, P<0.001), and 2-fold risk of insulin resistance (95% CI: 1.6-5.0, P<0.001; adjusted for body fat%). Within the overweight/obese subgroup, but not in normal-weight children, tCys accounted for 9% of the variability in body fat% (partial r = 0.30, P<0.001; adjusted for age and gender). tCys correlated positively with serum non-esterified fatty acids and leptin, partly independent of body fat, but was not associated with serum IL-6, TNF-α or MCP-1. A positive correlation with CRP disappeared after adjustment for BMI.

Conclusion

tCys is independently associated with obesity and insulin resistance in Hispanic children and adolescents, highlighting a previously underappreciated link between the sulfur amino acid metabolic pathway and obesity and cardiometabolic risk.     

In vitro antifungal activity of lactic acid bacteria low molecular peptides against spoilage fungi of bakery products

Bio-preservation, a promising preservation method that involves the use of “friendly” microorganisms such as lactic acid bacteria, has recently become a topic of considerable interest. In the present study, 16 lactic acid bacteria isolates were evaluated for antifungal activity against six fungi commonly associated with bread spoilage. The antifungal compounds were heat stable at 121 °C, and only four isolates, DU15, IT10, TE10, and IS10, showed partial loss of activity when supernatants were treated with proteolytic enzymes. The four isolates showed high inhibition activity at pH 3 and were identified using 16S rDNA sequencing as belonging to Leuconostoc mesenteroides DU15, Lactobacillus plantarum TE10, Lactobacillus plantarum IT10, and Lactobacillus plantarum IS10. The minimum germination inhibitions were 30 mg, 50 mg, 40 mg, and 50 mg for TE10, IT10, DU15, and IS10 respectively. The optimum conditions for the strains to produce antifungal compounds were 37 °C for 48 h for IT10, IS10, and TE10, and 30 °C for 24 h for DU15. Antifungal activity was increased threefold when supernatants were filtered using 10 KDa membranes. These findings demonstrate the potential of using lactic acid bacteria antifungal peptides as natural preservatives in bakery products to control the growth of spoilage fungi.     

Modulatory effect of linoleic and oleic acid on cell proliferation and lipid metabolism gene expressions in primary bovine satellite cells

This study was performed to elucidate the effects of linoleic acid (LA), oleic acid (OA) and their combination (LA?+?OA) on cell proliferation, apoptosis, necrosis, and the lipid metabolism related gene expression in bovine satellite cells (BSCs), isolated from bovine muscles. Cell viability was significantly increased with the OA and LA treatment. Furthermore, LA?+?OA enhanced cell proliferation in a dose-dependent manner (10 to 100?µM), whereas it lowered at 250?µM. In addition, a cell-cycle analysis showed that 100?µM of LA and OA markedly decreased the G0/G1 phase proportion (62.58% and 61.33%, respectively), compared to controls (68.02%), whereas the S-phase cells’ proportion was increased. The ratio of G2/M phase cells was not significantly different among the groups. Moreover, analyses with AO/EtBr staining showed that no apoptosis occurred. Necrosis were determined by flow cytometry using Annexin V-FITC/PI staining which revealed no early apoptosis in the cells pretreated with LA or OA, but occurred in the LA?+?OA group. We also analyzed the mRNA expression of lipid metabolizing genes such as peroxisome proliferator receptor alfa (PPARα), peroxisome proliferator receptor gamma (PPARγ), acyl-CoA oxidase (ACOX), lipoprotein lipase (LPL), carnitine palmitoyl transferase (CPT-1), and fatty-acid binding protein4 (FABP4), which were upregulated in LA or OA treated cells compared to the control group. In essence, LA and OA alone promote the cell proliferation without any apoptosis and necrosis, which might upregulate the lipid metabolism related gene expressions, and increase fatty-acid oxidation in the BSCs’ lipid metabolism.     

Surface modification of lipid nanoparticles for gene therapy

Gene therapies have the potential to target and effectively treat a variety of diseases including cancer as well as genetic, neurological, and autoimmune disorders. Although we have made significant advances in identifying non-viral strategies to deliver genetic cargo, certain limitations remain. In general, gene delivery is challenging for several reasons including the instabilities of nucleic acids to enzymatic and chemical degradation and the presence of restrictive biological barriers such as cell, endosomal and nuclear membranes. The emergence of lipid nanoparticles (LNPs) helped overcome many of these challenges. Despite its success, further optimization is required for LNPs to yield efficient gene delivery to extrahepatic tissues, as LNPs favor accumulation in the liver after systemic administration. In this mini-review, we provide an overview of current preclinical approaches in that LNP surface modification was leveraged for cell and tissue targeting by conjugating aptamers, antibodies, and peptides among others. In addition to their cell uptake and efficiency-enhancing effects, we outline the (dis-)advantages of the different targeting moieties and commonly used conjugation strategies.