RNA and β-Hemolysin of Group B Streptococcus Induce Interleukin-1β (IL-1β) by Activating NLRP3 Inflammasomes in Mouse Macrophages

The inflammatory cytokine IL-1β is critical for host responses against many human pathogens. Here, we define Group B Streptococcus (GBS)-mediated activation of the Nod-like receptor-P3 (NLRP3) inflammasome in macrophages. NLRP3 activation requires GBS expression of the cytolytic toxin, β-hemolysin, lysosomal acidification, and leakage. These processes allow the interaction of GBS RNA with cytosolic NLRP3. The present study supports a model in which GBS RNA, along with lysosomal components including cathepsins, leaks out of lysosomes and interacts with NLRP3 to induce IL-1β production.     

Antibiosis against the green peach aphid requires the Arabidopsis thaliana MYZUS PERSICAE-INDUCED LIPASE1 gene

The green peach aphid (GPA) (Myzus persicae Sülzer) is an important sap-sucking pest of a large variety of plants, including Arabidopsis thaliana. Arabidopsis utilizes a combination of defenses that deter insects from settling on the plant, limit insect feeding and curtail insect reproduction. We demonstrate that the previously uncharacterized Arabidopsis MPL1 (MYZUS PERSICAE-INDUCED LIPASE1) gene has an important role in defense against the GPA. MPL1 expression was rapidly induced to high level in GPA-infested plants. Furthermore, the GPA population was larger on the mpl1 mutant than the wild-type (WT) plant. In contrast, constitutive over-expression of MPL1 from the Cauliflower mosaic virus 35S gene promoter curtailed the size of the GPA population. Insect settling and feeding behavior were unaffected on the mpl1 mutant. However, compared with the phloem-sap enriched petiole exudate from the WT plant, mpl1 petiole exudate was deficient in an activity that restricts insect reproduction on a synthetic diet. Furthermore, MPL1 was required for the heightened accumulation of an antibiotic activity in petiole exudate of the Arabidopsis ssi2 mutant, which exhibits enhanced resistance to GPA. These results indicate that MPL1 has an essential function in antibiosis against GPA. The MPL1 protein exhibits homology to lipases and recombinant MPL1 has lipase activity, thus suggesting that a MPL1-dependent lipid, or a product thereof, has an important role in antibiosis against GPA.     

Bioassay of three sulphur containing compounds as rat attractant admixed in cereal-based bait against Rattus rattus Linn

Three sulphur containing compounds, carbon disulphide, dimethyl disulphide and dimethyl sulphide were bioassayed for preference after admixing them in cereal base as ready bait block for use against commensal rat, R. rattus (wild type) in four way choice chamber system. Rat preference for different baits was also studied with automatic recording animal activity meter. Rats exhibited attractancy to the baits at 0.005% concentration of all the three compounds while at 0.01% concentration they have showed repellency. Dimethyl sulphide at 0.005% concentration showed better attractancy towards both sexes of rat.     

Y-27632 enhances differentiation of blastocyst like cystic human embryoid bodies to endocrinologically active trophoblast cells on a biomimetic platform

Trophoblast differentiation and formation of the placenta are important events linked to post-implantation embryonic development. Models mimicking the biology of trophoblast differentiation in a post-implantation maternal microenvironment are needed for understanding disorders like placental-ischemia or for applications in drug-screening, and would help in overcoming the ethical impasse on using human embryos for such research. Here we attempt to create such a model by using embryoid bodies (EBs) and a biomimetic platform composed of a bilayer of fibronectin and gelatin on top of low-melting agarose. Using this model we test the hypothesis that cystic-EBs (day 30) that resemble blastocysts morphologically, are better sources as compared to noncytic EBs (day 10), for functional trophoblast differentiation; and that the Rho kinases inhibitor Y27632 can enhance this differentiation. Non/cytic EBs with/out Y27632 were grown on this platform for 28 days, and screened from secretion and expression of trophoblast and other lineage markers using ECLIA, RT-PCR, and Immunofluorescence. All EBs attached on this surface and rapidly proliferated into hCG and progesterone (P2) secreting functional trophoblast cells. However, the cells derived from cytic-EBs and cytic-EBs+ Y27632 showed the maximum secretion of these hormones and expressed IGF2, supporting our hypothesis. Also Y27632 reduced extraembryonic endoderm and trophoblast lineage differentiation from early noncystic-EBs, whereas, it specifically enhanced the induction of trophoblast and multinucleated syncitiotrophoblast differentiation from late cystic-EBs. In vivo trophoblast differentiation can be replicated in fibronectin based biomaterials, using cytic-EBs and by maneuvering the Rho-ROCK pathways. Response of EBs to a compound may vary temporally, and determination of their right stage is crucial for applications in directed-differentiation or drug-screening.     

Designing nanoconjugates to effectively target pancreatic cancer cells in vitro and in vivo

Background

Pancreatic cancer is the fourth leading cause of cancer related deaths in America. Monoclonal antibodies are a viable treatment option for inhibiting cancer growth. Tumor specific drug delivery could be achieved utilizing these monoclonal antibodies as targeting agents. This type of designer therapeutic is evolving and with the use of gold nanoparticles it is a promising approach to selectively deliver chemotherapeutics to malignant cells.Gold nanoparticles (GNPs) are showing extreme promise in current medicinal research. GNPs have been shown to non-invasively kill tumor cells by hyperthermia using radiofrequency. They have also been implemented as early detection agents due to their unique X-ray contrast properties; success was revealed with clear delineation of blood capillaries in a preclinical model by CT (computer tomography). The fundamental parameters for intelligent design of nanoconjugates are on the forefront. The goal of this study is to define the necessary design parameters to successfully target pancreatic cancer cells.

Methodology/Principal Findings

The nanoconjugates described in this study were characterized with various physico-chemical techniques. We demonstrate that the number of cetuximab molecules (targeting agent) on a GNP, the hydrodynamic size of the nanoconjugates, available reactive surface area and the ability of the nanoconjugates to sequester EGFR (epidermal growth factor receptor), all play critical roles in effectively targeting tumor cells in vitro and in vivo in an orthotopic model of pancreatic cancer.

Conclusion

Our results suggest the specific targeting of tumor cells depends on a number of crucial components 1) targeting agent to nanoparticle ratio 2) availability of reactive surface area on the nanoparticle 3) ability of the nanoconjugate to bind the target and 4) hydrodynamic diameter of the nanoconjugate. We believe this study will help define the design parameters for formulating better strategies for specifically targeting tumors with nanoparticle conjugates.     

Effect of endothelial cell polarity on beta-amyloid-induced migration of monocytes across normal and AD endothelium

During normal aging and amyloid beta-peptide (Abeta) disorders such as Alzheimer's disease (AD), one finds increased deposition of Abeta and activated monocytes/microglial cells in the brain. Our previous studies show that Abeta interaction with a monolayer of normal human brain microvascular endothelial cells results in increased adherence and transmigration of monocytes. Relatively little is known of the role of Abeta accumulated in the AD brain in mediating trafficking of peripheral blood monocytes (PBM) across the blood-brain barrier (BBB) and concomitant accumulation of monocytes/microglia in the AD brain. In this study, we showed that interaction of Abeta(1--40) with apical surface of monolayer of brain endothelial cells (BEC), derived either from normal or AD individuals, resulted in increased transendothelial migration of monocytic cells (HL-60 and THP-1) and PBM. However, transmigration of monocytes across the BEC monolayer cultivated in a Transwell chamber was increased 2.5-fold when Abeta was added to the basolateral side of AD compared with normal individual BEC. The Abeta-induced transmigration of monocytes was inhibited in both normal and AD-BEC by antibodies to the putative Abeta receptor, receptor for advanced glycation end products (RAGE), and to the endothelial cell junction molecule, platelet-endothelial cell adhesion molecule-1 (PECAM-1). We conclude that interaction of Abeta with the basolateral surface of AD-BEC induces cellular signaling, promoting transmigration of monocytes from the apical to basolateral direction. We suggest that Abeta in the AD brain parenchyma or cerebrovasculature initiates cellular signaling that induces PBM to transmigrate across the BBB and accumulate in the brain.     

Effect of polymorphic form on the functional properties of cellulose: A comparative study

The powder and tableting properties of cellulose II powders (MCCII) and (SDCII) were evaluated and compared with common direct compression binders. The cellulose II polymorphs offered more benefits in terms of functionality as compared with cellulose I (Avicel^® PH-102) spray dried lactose and starch. Spray dried cellulose II (SDCII) had a better disintegrant ability, but a lower compactibility than microcrystalline cellulose I (Avicel^® PH-102). However, when mixed and compressed with acetaminophen, SDCII was as compactable as cellulose I. Further, unprocessed cellulose II has a comparable compressibility to that of cellulose I. SDCII was found to be less friable, less sensitive to magnesium stearate, and possessed better acetaminophen loading capacity than unprocessed cellulose II and comparable to that of cellulose I. The cellulose II materials showed potential for use as a direct compression excipient.     

Emerging Insights into Noncanonical Inflammasome Recognition of Microbes

Inflammasomes are cytosolic multi-molecular complexes that sense intracellular microbial danger signals and metabolic perturbations. Inflammasome activation leads to the activation of caspase-1 and the release of pro-inflammatory cytokines IL-1β and IL-18 accompanied by cell death. An inflammasome-based surveillance machinery for Gram-negative bacterial infections has been recently discovered. This noncanonical inflammasome relies on sensing the cytosolic presence of lipopolysaccharide of Gram-negative bacteria via inflammatory caspases such as caspase-4, -5, and -11. This review discusses the recent findings related to the mechanism of activation of the noncanonical inflammasome and its biological functions.     

NO and ROS implications in the organization of root system architecture

Over the past decades the role of nitric oxide (NO) and reactive oxygen species (ROS) in signaling and cellular responses to stress has witnessed an exponential trend line. Despite advances in the subject, our knowledge of the role of NO and ROS as regulators of stress and plant growth and their implication in signaling pathways is still partial. The crosstalk between NO and ROS during root formation offers new domains to be explored, as it regulates several plant functions. Previous findings indicate that plants utilize these signaling molecules for regulating physiological responses and development. Depending upon cellular concentration, NO either can stimulate or impede root system architecture (RSA) by modulating enzymes through post-translational modifications. Similarly, the ROS signaling molecule network, in association with other hormonal signaling pathways, control the RSA. The spatial regulation of ROS controls cell growth and ROS determine primary root and act in concert with NO to promote lateral root primordia. NO and ROS are two central messenger molecules which act differentially to upregulate or downregulate the expression of genes pertaining to auxin synthesis and to the configuration of root architecture. The investigation concerning the contribution of donors and inhibitors of NO and ROS can further aid in deciphering their role in root development. With this background, this review provides comprehensive details about the effect and function of NO and ROS in the development of RSA.     

Pathogenic BCL11A variants provide insights into the mechanisms of human fetal hemoglobin silencing

Increased production of fetal hemoglobin (HbF) can ameliorate the severity of sickle cell disease and β-thalassemia. BCL11A has been identified as a key regulator of HbF silencing, although its precise mechanisms of action remain incompletely understood. Recent studies have identified pathogenic mutations that cause heterozygous loss-of-function of BCL11A and result in a distinct neurodevelopmental disorder that is characterized by persistent HbF expression. While the majority of cases have deletions or null mutations causing haploinsufficiency of BCL11A, several missense variants have also been identified. Here, we perform functional studies on these variants to uncover specific liabilities for BCL11A’s function in HbF silencing. We find several mutations in an N-terminal C2HC zinc finger that increase proteasomal degradation of BCL11A. We also identify a distinct C-terminal missense variant in the fifth zinc finger domain that we demonstrate causes loss-of-function through disruption of DNA binding. Our analysis of missense variants causing loss-of-function in vivo illuminates mechanisms by which BCL11A silences HbF and also suggests potential therapeutic avenues for HbF induction to treat sickle cell disease and β-thalassemia.