Oxidized phospholipids cause changes in jejunum mucus that induce dysbiosis and systemic inflammation

We previously reported that adding a concentrate of transgenic tomatoes expressing the apoA-I mimetic peptide 6F (Tg6F) to a Western diet (WD) ameliorated systemic inflammation. To determine the mechanism(s) responsible for these observations, Ldlr^?/? mice were fed chow, a WD, or WD plus Tg6F. We found that a WD altered the taxonomic composition of bacteria in jejunum mucus. For example, Akkermansia muciniphila virtually disappeared, while overall bacteria numbers and lipopolysaccharide (LPS) levels increased. In addition, gut permeability increased, as did the content of reactive oxygen species and oxidized phospholipids in jejunum mucus in WD-fed mice. Moreover, gene expression in the jejunum decreased for multiple peptides and proteins that are secreted into the mucous layer of the jejunum that act to limit bacteria numbers and their interaction with enterocytes including regenerating islet-derived proteins, defensins, mucin 2, surfactant A, and apoA-I. Following WD, gene expression also decreased for Il36γ, Il23, and Il22, cytokines critical for antimicrobial activity. WD decreased expression of both Atoh1 and Gfi1, genes required for the formation of goblet and Paneth cells, and immunohistochemistry revealed decreased numbers of goblet and Paneth cells. Adding Tg6F ameliorated these WD-mediated changes. Adding oxidized phospholipids ex vivo to the jejunum from mice fed a chow diet reproduced the changes in gene expression in vivo that occurred when the mice were fed WD and were prevented with addition of 6F peptide. We conclude that Tg6F ameliorates the WD-mediated increase in oxidized phospholipids that cause changes in jejunum mucus, which induce dysbiosis and systemic inflammation.     

Role of tumor suppressor p53 and micro-RNA interplay in multiple myeloma pathogenesis

The molecular mechanisms underlying dysregulated wild type (wt) p53 in multiple myeloma (MM) have been subjects of intense investigation for years. Indeed, correlation of rarely occurring TP53 gene mutations or deletions with adverse clinical outcomes in MM patients is strongly established, while in majority of cases wtp53 seems to be non-functional or dysregulated bearing a high clinical impact. Interestingly, findings from recent investigations show that micro-RNAs (miRNAs) may contribute to suppression of wtp53 in MM, as they are now known to function as key regulatory elements in the p53 network. This area is shedding new light on understanding the biologic effects of dysregulated p53 in MM pathogenesis especially drug resistance. miRNAs such as miR-125b (oncomiR) or miR-34a (tumor suppressor-miR) can be negative or positive regulators of wtp53 function, respectively, with specific effects on MM cell viability. On the other hand, our knowledge of miRNA interaction with mutant (mt) p53 in MM, which is rather related to disease progression and resistance to therapy, is limited which demands in-depth exploration. Here, we will put forward the current knowledge on miRNA-p53 interaction in MM and its role in MM pathogenesis including drug resistance. We will also highlight the pre-clinical approaches for therapeutic application of miRNAs targeting p53 pathway.     

Localized Surface Plasmon Resonance (LSPR)-Based Nanobiosensor for Methamphetamin Measurement

Aptamers are DNA or RNA single-stranded molecules that bind specifically to target molecules with high affinity. Function of nucleic acid aptamers is based on organized tertiary structure of them that is related to primary sequence, length of nucleic acid molecule, and environmental conditions. Herein, a localized surface plasmon resonance (LSPR) nanobioprobe has been developed based on specific aptamer-conjugated gold nanoparticles for rapid detection of methamphetamine. Detection of methamphetamine was studied via monitoring the gold nanoparticles (GNPs) LSPR band alterations in the presence of different concentrations. The covalent conjugation has been confirmed with FT-IR spectroscopy, and size alterations of gold nanoparticles before and after the conjugation state were monitored using dynamic light scattering (DLS) technique. The results show high affinity of aptamer to methamphetamine. Moreover, the results show conjugated aptamer with GNP in different concentrations of methamphetamine that contribute to color changes that is visible with unaided eye. Also, 14 nm LSPR shift was seen after conjugation of aptamer with GNP. Nanoparticle diameter after conjugation with aptamer was increased from 30 to 91 nm and decreased after incubation with methamphetamine (due to folding) from 91 to 84 nm. Detection limit of this designed nanoprobe is 500 nM. Plasmonic nanoparticle-based nanobioprobe is a new field for development of sensitive detection systems.

     

The Interplay of Tau Protein and β-Amyloid: While Tauopathy Spreads More Profoundly Than Amyloidopathy,Both Processes Are Almost Equally Pathogenic

Cellular and Molecular Neurobiology - Alzheimer’s disease (AD) is a neurodegenerative disorder, in which amyloid precursor protein (APP) misprocessing and tau protein hyperphosphorylation are...     

Conditional knock-out of integrin-linked kinase demonstrates an essential role in protein kinase B/Akt activation

Protein kinase B (PKB/Akt) plays a pivotal role in signaling pathways downstream of phosphatidylinositol 3-kinase, regulating fundamental processes such as cell survival, cell proliferation, differentiation, and metabolism. PKB/Akt activation is regulated by phosphoinositide phospholipid-mediated plasma membrane anchoring and by phosphorylation on Thr-308 and Ser-473. Whereas the Thr-308 site is phosphorylated by PDK-1, the identity of the Ser-473 kinase has remained unclear and controversial. The integrin-linked kinase (ILK) is a potential regulator of phosphorylation of PKB/Akt on Ser-473. Utilizing double-stranded RNA interference (siRNA) as well as conditional knock-out of ILK using the Cre-Lox system, we now demonstrate that ILK is essential for the regulation of PKB/Akt activity. ILK knock-out had no effect on phosphorylation of PKB/Akt on Thr-308 but resulted in almost complete inhibition of phosphorylation on Ser-473 and significant inhibition of PKB/Akt activity, accompanied by significant stimulation of apoptosis. The inhibition of PKB/Akt Ser-473 phosphorylation was rescued by kinase-active ILK but not by a kinase-deficient mutant of ILK, suggesting a role for the kinase activity of ILK in the stimulation of PKB/Akt phosphorylation. ILK knock-out also resulted in the suppression of phosphorylation of GSK-3beta on Ser-9 and cyclin D1 expression. These data establish ILK as an essential upstream regulator of PKB/Akt activation.     

Overexpression of <Emphasis Type="Italic">spoT</Emphasis> gene in coccoid forms of clinical <Emphasis Type="Italic">Helicobacter pylori</Emphasis> isolates

Helicobacter pylori (H. pylori) can convert to coccoid form in unfavorable conditions or as a result of antibiotic treatment. In order to adapt to harsh environments, H. pylori requires a stringent response which, encoded by the spoT gene, has a bifunctional enzyme possessing both (p)ppGpp synthetic and degrading activity. Our goal in this study was to compare spoT gene expression in spiral and induced coccoid forms of H. pylori with use of amoxicillin. First, clinical isolate coccoid forms were induced with amoxicillin; then, the viability test was analyzed by flow cytometer. After RNA extraction, cDNA synthesis and designing a specific primer for spoT gene, evaluation of the desired gene expression in both forms were studied. Bacterial isolates exposed to amoxicillin at MIC and 1/2 MIC induced morphological conversion better and faster than other MIC concentration. The expression of spoT gene was significantly downregulated in spiral forms of H. pylori, while the gene expression was upregulated and + 30.3-fold changes was seen in coccoid forms of bacterium. To summarize, spoT gene is one of the key factors for antibiotic resistance and its enhanced expression in coccoid form can be a valuable diagnostic marker for recognition of H. pylori during morphological conversion.     

Assessment of the effect of biosurfactant produced by Pseudomonas aeruginosa in lethality of Bacillus thuringiensis Berl. against 3rd instars larvae of white cabbage butterfly (Pieris brassicae L.)

Surfactant that is produced from cheap sources like oil sludge by biological agents such as bacteria can be used in various industrial processes. For example, it can be used in environmental processes such as bioremediation and elimination of environmental pollutants, and acts as synergistic agents and distributor pesticides on waxy leaves in agriculture. In this study, biosurfactant which is produced by Pseudomonas aeruginosa (isolated from petroleum sludge) at the intervals of 24, 48, 72 and 96?h, along with chemical surfactant Tween 80 and the biological control agent, Bacillus thuringiensis, in a pilot project for controlling one important cabbage pest (Pieris brassicae), their synergistic properties were evaluated. Statistical analysis of the results showed that B. thuringiensis in combination with biosurfactant produced at different times and B. thuringiensis in combination with chemical surfactant Tween 80 when compared with control treatments like B. thuringiensis alone and B. thuringiensis plus tween 80 as positive controls and distilled water as negative control have significant differences (p?<?0.05). This research showed that surfactant treatment produced at the intervals of 24 and 48?h in combination with B. thuringiensis has the greatest synergistic effect when compared to chemical surfactant treatment. This study concluded that biosurfactant can be used as a distributor and synergistic agent against plant pests and in addition to this, their biological roles in bioremediation can be used as a viable alternative to non-economical chemical surfactants that annually enter millions of tonnes of harmful chemical substances into the fields and underground water.