Abundant Intracellular IgG in Enterocytes and Endoderm Lacking FcRn

FcRn, a non-classical MHCI molecule, transports IgG from mother to young and regulates the rate of IgG degradation throughout life. Brambell proposed a mechanism that unified these two functions, saying that IgG was pinocytosed nonspecifically by the cell into an FcRn-expressing endosome, where, at low pH, it bound to FcRn and was exocytosed. This theory was immediately challenged by claims that FcRn specificity for ligand could be conferred at the cell surface in neonatal jejunum. Assessing Brambell''s hypothesis we found abundant nonspecifically endocytosed IgG present in the cytoplasm of FcRn^−/− enterocytes. Further, IgG was present in the intercellular clefts and the cores of FcRn^+/+ but not FcRn^−/− jejunum. FcRn specificity for ligand could be determined within the cell.     

Role of alpha-melanocyte stimulating hormone (α-MSH) in modulating the molecular mechanism adopted by melanocytes of Bos indicus under UVR stress

Molecular and Cellular Biochemistry - Ultraviolet radiations (UVR) are responsible for a wide variety of acute and chronic effects on the animal skin. However, the effect of UVR-induced oxidative...     

Investigation on the Fusarium induced stress protein (FISP) in wheat: Immunolocalisation in root cells

Abstract

Fusarium induced-stress-protein (FISP) of ～51 kDa molecular mass was detected in seven day old germinated wheat (Triticum aestivum var Sonalika) seedlings infected with F. oxysporum for a period of seven days. This particular stress protein (FISP) of ～51 kDa was over-expressed in the case of Fusarium infected seedlings compared to the untreated seedlings where the presence of this protein was insignificant. Localisation of this ～51 kDa protein in root tissue by anti-CSAP (Cadmium Stress Associated Protein) antiserum showed a significantly higher number of gold particles in the case of Fusarium infected root tissue compared to the untreated control. A unique type of organised localisation of FISP around the plasma membrane and outer vacuolar membrane suggests its defensive role against Fusarium infection that might be a general stress protein against biotic and abiotic stresses.     

Polysaccharide-rich fraction of Termitomyces eurhizus accelerate healing of indomethacin induced gastric ulcer in mice

The current study aims to determine the healing activity of water soluble polysaccharide-rich fraction of a wild mushroom, Termitomyces eurhizus (TEps) against the indomethacin induced gastric ulceration in mice model. Gastric tissue histology, myeloperoxidase (MPO) activity, cyclooxygenases (COX) 1 and 2 expression, prostaglandin E₂ (PGE₂) synthesis, and modulation of pro/anti inflammatory cytokines expression were studied for this purpose. Histological study shows that TEps (20 mg/kg) effectively healed the gastric ulceration. Based on biochemical results, the healing capacities of TEps could be attributed to reduction of MPO activity and protection of mucosal mucin content. Enhanced synthesis of PGE₂ by modulation of COX-1 and COX-2 expression and a prominent shift of cytokines expression from pro (TNF-α, IL-1ß) to anti inflammatory (IL-10) side are also held responsible for ulcer healing. The preliminary study highlights the anti-ulcerogenic property of polysaccharide-rich fraction of Termitomyces eurhizus and opens an alternative cure for NSAID induced gastroduodenal diseases.     

Deregulation of poly(A) polymerase I in Escherichia coli inhibits protein synthesis and leads to cell death

Polyadenylation plays important roles in RNA metabolism in both prokaryotes and eukaryotes. Surprisingly, deregulation of polyadenylation by poly(A) polymerase I (PAP I) in Escherichia coli leads to toxicity and cell death. We show here that mature tRNAs, which are normally not substrates for PAP I in wild-type cells, are rapidly polyadenylated as PAP I levels increase, leading to dramatic reductions in the fraction of aminoacylated tRNAs, cessation of protein synthesis and cell death. The toxicity associated with PAP I is exacerbated by the absence of either RNase T and/or RNase PH, the two major 3′ → 5′ exonucleases involved in the final step of tRNA 3′-end maturation, confirming their role in the regulation of tRNA polyadenylation. Furthermore, our data demonstrate that regulation of PAP I is critical not for preventing the decay of mRNAs, but rather for maintaining normal levels of functional tRNAs and protein synthesis in E. coli, a function for polyadenylation that has not been observed previously in any organism.     

Chronotype preferences of college students from varied altitude backgrounds in Ethiopia

ABSTRACT

The purpose of this study was to compare chronotype preferences of college students from high- and low-altitude backgrounds living in a tropical setting of Ethiopia. Chronotype (morningness–eveningness) is a preference for a given time of day for physical or mental activities. The present cross-sectional study employed Horne and Osteberg Morningness-Eveningness Questionnaires to evaluate chronotype preferences. The chronotype preference of 264 male college students from varied altitude backgrounds indicated significant differences (p < 0.001). Our findings confirm our hypothesis, of the prevalence of M-types dominant chronotype among college students at low than high altitude. However, we did not confirm our second hypothesis, since students from high-altitude backgrounds were generally I-type dominant chronotype. Similarly, students’ academic performances from low- compared to high-altitudes backgrounds also indicated significant differences (p < 0.003). Better academic performances were seen in students with I-type chronotype orientations from high altitudes.     

The Relaxin Receptor (RXFP1) Utilizes Hydrophobic Moieties on a Signaling Surface of Its N-terminal Low Density Lipoprotein Class A Module to Mediate Receptor Activation

The peptide hormone relaxin is showing potential as a treatment for acute heart failure. Although it is known that relaxin mediates its actions through the G protein-coupled receptor relaxin family peptide receptor 1 (RXFP1), little is known about the molecular mechanisms by which relaxin binding results in receptor activation. Previous studies have highlighted that the unique N-terminal low density lipoprotein class A (LDLa) module of RXFP1 is essential for receptor activation, and it has been hypothesized that this module is the true “ligand” of the receptor that directs the conformational changes necessary for G protein coupling. In this study, we confirmed that an RXFP1 receptor lacking the LDLa module binds ligand normally but cannot signal through any characterized G protein-coupled receptor signaling pathway. Furthermore, we comprehensively examined the contributions of amino acids in the LDLa module to RXFP1 activity using both gain-of-function and loss-of-function mutational analysis together with NMR structural analysis of recombinant LDLa modules. Gain-of-function studies with an inactive RXFP1 chimera containing the LDLa module of the human LDL receptor (LB2) demonstrated two key N-terminal regions of the module that were able to rescue receptor signaling. Loss-of-function mutations of residues in these regions demonstrated that Leu-7, Tyr-9, and Lys-17 all contributed to the ability of the LDLa module to drive receptor activation, and judicious amino acid substitutions suggested this involves hydrophobic interactions. Our results demonstrate that these key residues contribute to interactions driving the active receptor conformation, providing further evidence of a unique mode of G protein-coupled receptor activation.     

Secondary amines containing one aromatic nitro group: Preparation,nitrosation, sustained nitric oxide release,and the synergistic effects of released nitric oxide and an arginase inhibitor on vascular smooth muscle cell proliferation

Atherosclerosis, a leading cause of death worldwide, is associated with the excessive proliferation of vascular smooth muscle cells. Nitrogen monoxide, more commonly known as nitric oxide, inhibits this uncontrolled proliferation. Herein we report the preparation of two families of nitric oxide donors; beginning with the syntheses of secondary amine precursors, obtained through the reaction between 2 equiv of various monoamines with 2,4 or 2,6-difluoronitrobenzene. The purified secondary amines were nitrosated then subjected to a Griess reagent test to examine the slow and sustained nitric oxide release rate for each compound in both the absence and presence of reduced glutathione. The release rate profiles of these two isomeric families of NO-donors were strongly dependent on the number of side chain methylene units and the relative orientations of the nitro groups with respect to the N-nitroso moieties. The nitrosated compounds were then added to human aortic smooth muscle cell cultures, individually and in tandem with S-2-amino-6-boronic acid (ABH), a potent arginase inhibitor. Cell viability studies indicated a lack of toxicity of the amine precursors, in addition to anti-proliferative effects exhibited by the nitrosated compounds, which were enhanced in the presence of ABH.     

Effects of Bacillus amyloliquefaciens FZB42 on Lettuce Growth and Health under Pathogen Pressure and Its Impact on the Rhizosphere Bacterial Community

The soil-borne pathogen Rhizoctonia solani is responsible for crop losses on a wide range of important crops worldwide. The lack of effective control strategies and the increasing demand for organically grown food has stimulated research on biological control. The aim of the present study was to evaluate the rhizosphere competence of the commercially available inoculant Bacillus amyloliquefaciens FZB42 on lettuce growth and health together with its impact on the indigenous rhizosphere bacterial community in field and pot experiments. Results of both experiments demonstrated that FZB42 is able to effectively colonize the rhizosphere (7.45 to 6.61 Log ₁₀ CFU g⁻¹ root dry mass) within the growth period of lettuce in the field. The disease severity (DS) of bottom rot on lettuce was significantly reduced from severe symptoms with DS category 5 to slight symptom expression with DS category 3 on average through treatment of young plants with FZB42 before and after planting. The 16S rRNA gene based fingerprinting method terminal restriction fragment length polymorphism (T-RFLP) showed that the treatment with FZB42 did not have a major impact on the indigenous rhizosphere bacterial community. However, the bacterial community showed a clear temporal shift. The results also indicated that the pathogen R. solani AG1-IB affects the rhizosphere microbial community after inoculation. Thus, we revealed that the inoculant FZB42 could establish itself successfully in the rhizosphere without showing any durable effect on the rhizosphere bacterial community.     

Detecting Dysglycemia Using the 2015 United States Preventive Services Task Force Screening Criteria: A Cohort Analysis of Community Health Center Patients

BackgroundIn 2015, the United States Preventive Services Task Force (USPSTF) recommended targeted screening for prediabetes and diabetes (dysglycemia) in adults who are aged 40 to 70 y old and overweight or obese. Given increasing prevalence of dysglycemia at younger ages and lower body weight, particularly among racial/ethnic minorities, we sought to determine whether the current screening criteria may fail to identify some high-risk population subgroups.ConclusionsTargeted diabetes screening based on new USPSTF criteria may detect approximately half of adult community health center patients with undiagnosed dysglycemia and proportionately fewer racial/ethnic minorities than whites. Future research is needed to estimate the performance of these screening criteria in population-based samples.