Rice lectin receptor-like kinase provides salinity tolerance by ion homeostasis

Sensing stress and activating the downstream signaling pathways is the imperative step for stress response. Lectin receptor-like kinase (LecRLK) is an important family that plays a key role in sensing stress conditions through lectin receptor and activates downstream signaling by kinase domain. We identified the role of OsLecRLK gene for salinity stress tolerance and hypothesized its role in Na⁺ extrusion from cell. OsLecRLK overexpression and downregulation (through artificial miRNA) transgenic lines were developed and its comparison with wild-type (WT) plants were performed overexpression transgenic lines showed better performance, whereas downregulation showed poor performance than WT. Lower accumulation of reactive oxygen species (ROS), malondialdehyde and toxic ion, and a higher level of proline, RWC, ROS scavengers in overexpression lines lead us to the above conclusion. Based on the relative expression of stress-responsive genes, ionic content and interactome protein, working model highlights the role of OsLecRLK in the extrusion of Na⁺ ion from the cell. This extrusion is facilitated by a higher expression of salt overly sensitive 1 (Na⁺/K⁺ channel) in overexpression transgenic line. Altered expression of stress-responsive genes and changed biochemical and physiological properties of cell suggests an extensive reprogramming of the stress-responsive metabolic pathways by OsLecRLK under stress condition, which could be responsible for the salt tolerance capability.     

Enzymatic synthesis of cetyl oleate in a solvent-free medium using microwave irradiation and physicochemical evaluation

Abstract

A cosmetic ester, cetyl oleate was synthesized using microwave irradiated system. The esterification reaction was carried using Candida antarctica lipase B in a solvent-free media. The influence of various reaction parameters was studied, and the efficiency of Fermase CALB^TM10000 was compared with other enzymes. Equilibrium conversion of 97.5% was obtained within 20?min at 60?°C temperature, 1:2 oleic acid to cetyl alcohol molar ratio and 4% w/w dose of lipase. A comparative study showed that microwave irradiation is a much more efficient method than ultrasound irradiation and conventional heating. Fermase CALB^TM10000 was reusable over 6 enzymatic cycles as its stability improved under microwave system. Physicochemical parameters of cetyl oleate were tested in order to analyze its suitability for further cosmetic use.     

Circulating exosomal miRNAs in cardiovascular disease pathogenesis: New emerging hopes

Cardiovascular diseases (CVDs) are one of the leading causes of morbidity and mortality. Standard therapies have failed to significantly increase patients’ survival. Moreover, the majority of conventional screening procedures are ineffective for the diagnosis of CVDs at early stages. Accumulating evidence suggests that numerous cell types release a class of nano-sized vesicles named exosomes into the extracellular space. Exosomes are widely distributed in various body fluids and contain a number of diverse biomolecules such as proteins, lipids, and both mRNA and noncoding RNAs which reflect host-cell molecular architecture. MicroRNAs (miRNAs), which can be found in exosomes, could be taken up by both neighboring and distal cells. Not only has recent evidence indicated the regulatory role of exosomal miRNAs in the pathogenesis of CVD, but it has also been shown that differential expression of exosomal miRNAs in CVDs has made them promising biomarkers for early detection of CVDs. Owing to these remarkable features, exosomal miRNAs have emerged as hot spots in research. This review summarizes the role of exosomal miRNAs in the pathogenesis of CVDs and discusses their potential application in the clinical setting as both therapeutic and diagnostic tools.     

Circulating Mucosal Associated Invariant T Cells Are Activated in Vibrio cholerae O1 Infection and Associated with Lipopolysaccharide Antibody Responses

Background

Mucosal Associated Invariant T (MAIT) cells are innate-like T cells found in abundance in the intestinal mucosa, and are thought to play a role in bridging the innate-adaptive interface.

Methods

We measured MAIT cell frequencies and antibody responses in blood from patients presenting with culture-confirmed severe cholera to a hospital in Dhaka, Bangladesh at days 2, 7, 30, and 90 of illness.

Results

We found that MAIT (CD3⁺CD4⁻CD161^hiVα7.2⁺) cells were maximally activated at day 7 after onset of cholera. In adult patients, MAIT frequencies did not change over time, whereas in child patients, MAITs were significantly decreased at day 7, and this decrease persisted to day 90. Fold changes in MAIT frequency correlated with increases in LPS IgA and IgG, but not LPS IgM nor antibody responses to cholera toxin B subunit.

Conclusions

In the acute phase of cholera, MAIT cells are activated, depleted from the periphery, and as part of the innate response against V. cholerae infection, are possibly involved in mechanisms underlying class switching of antibody responses to T cell-independent antigens.     

RO 90-7501 Enhances TLR3 and RLR Agonist Induced Antiviral Response

Recognition of virus infection by innate pattern recognition receptors (PRRs), including membrane-associated toll-like receptors (TLR) and cytoplasmic RIG-I-like receptors (RLR), activates cascades of signal transduction pathways leading to production of type I interferons (IFN) and proinflammatory cytokines that orchestrate the elimination of the viruses. Although it has been demonstrated that PRR-mediated innate immunity plays an essential role in defending virus from infection, it also occasionally results in overwhelming production of proinflammatory cytokines that cause severe inflammation, blood vessel leakage and tissue damage. In our efforts to identify small molecules that selectively enhance PRR-mediated antiviral, but not the detrimental inflammatory response, we discovered a compound, RO 90–7501 (‘2’-(4-Aminophenyl)-[2,5′-bi-1H-benzimidazol]-5-amine), that significantly promoted both TLR3 and RLR ligand-induced IFN-β gene expression and antiviral response, most likely via selective activation of p38 mitogen-activated protein kinase (MAPK) pathway. Our results thus imply that pharmacological modulation of PRR signal transduction pathways in favor of the induction of a beneficial antiviral response can be a novel therapeutic strategy.     

The enhancement of stability of p53 in MTBP induced p53–MDM2 regulatory network

We have modeled an MTBP-MDM2–p53 regulatory network by integrating p53–MDM2 autoregulatory model (Proctor and Gray, 2008) with the effect of a cellular protein MTBP (MDM2 binding protein) which is allowed to bind with MDM2 (Brady et al., 2005). We study this model to investigate the activation of p53 and MDM2 steady state levels induced by MTBP protein under different stress conditions. Our simulation results in three approaches namely deterministic, Chemical Langevin equation and stochastic simulation of Master equation show a clear transition from damped limit cycle oscillation to fixed point oscillation during a certain time period with constant stress condition in the cell. This transition is the signature of transition of p53 and MDM2 levels from activated state to stabilized steady state levels. We present various phase diagrams to show the transition between unstable and stable states of p53 and MDM2 concentration levels and also their possible relations among critical value of the parameters at which the respective protein level reach stable steady states. In the stochastic approach, the dynamics of the proteins become noise induced process depending on the system size. We found that this noise enhances the stability of the p53 steady state level.     

A monoclonal antibody to Shigella dysenteriae serotype 13 cross-reacting with Shiga toxin

Abstract A monoclonal antibody (mAb ICT6) was produced against the newly described Shigella dysenteriae serotype type 13. The mAb was of IgM isotype and recognized purified Shiga toxin in ELISA and immunoblot. It also recognized periplasmic extract S. dysenteriae type 13 in immunoblot as did an affinity-purified polyclonal rabbit antiserum and a previously described monoclonal antibody to the B subunit of Shiga toxin. The mAb ICT6 did not neutralize the cytotoxic effects or S. dysenteriae type 13, Shiga toxin or periplasmic extracts of S. dysenteriae type 1 for HeLa cells.