Induction of cell differentiation and promotion of endocan gene expression in stomach cancer by melatonin

The pineal hormone melatonin has been shown to have anticancer therapeutic properties in patients with gastric cancer, the mechanisms, however, remain largely unknown. The present study examined the effects of melatonin on cell differentiation related factors, namely, endocan, alkaline phosphatase, and lactate dehydrogenase, in gastric adenocarcinoma cell line SGC7901. Expression of endocan was significantly decreased in tissue of gastric cancer as compared to normal stomach tissue, as determined by immunohistochemical staining, and there is correlation between the degree of the decrease of endocan expression and the degree of differentiation of the cancer. Treatment of cultured gastric adenocarcinoma cells with 10⁻⁴ mol/l melatonin significantly increased the gene expression of endocan and down-regulated the activity of alkaline phosphatase and lactate dehydrogenase, two enzymes that promote de-differentiation in gastric tissue; and there was a negative correlation between the level of endocan expression and the activities of differentiation marker enzymes in the melatonin treated cancer cells. Gastric cancer cells treated with melatonin show more differentiated morphologic phenotype as compared the untreated cells. The findings indicate that melatonin may play its anticancer role in gastric adenocarcinoma by acting as a differentiation inducer.     

Dynamic Assembly of Brambleberry Mediates Nuclear Envelope Fusion during Early Development

To accommodate the large cells following zygote formation, early blastomeres employ modified cell divisions. Karyomeres are one such modification, mitotic intermediates wherein individual chromatin masses are surrounded by nuclear envelope; the karyomeres then fuse to form a single mononucleus. We identified brambleberry, a maternal-effect zebrafish mutant that disrupts karyomere fusion, resulting in formation of multiple micronuclei. As karyomeres form, Brambleberry protein localizes to the nuclear envelope, with prominent puncta evident near karyomere-karyomere interfaces corresponding to membrane fusion sites. brambleberry corresponds to an unannotated gene with similarity to Kar5p, a protein that participates in nuclear fusion in yeast. We also demonstrate that Brambleberry is required for pronuclear fusion following fertilization in zebrafish. Our studies provide insight into the machinery required for karyomere fusion and suggest that specialized proteins are necessary for proper nuclear division in large dividing blastomeres.     

Extraction and radicals scavenging activity of polysaccharides with microwave extraction from mung bean hulls

Extraction variables of microwave extraction mung polysaccharides (MEMPs) from mung bean hulls were optimized by Box-Behnken design. The optimal extraction parameter of MEMP was 700W, 70s and 17mL/g, and highest recovery was 60.03±2.56mgGE/gDW, which was agreed closely with predicted values. Two purified polysaccharide fractions (MEMP-1 and MEMP-2) were successfully isolated through DEAE cellulose-52 chromatography and Sephadex G-100 size-exclusion chromatography in steps. MEMP-1 was mainly composed of mannose and galactose while that of MEMP-2 was rhamnose and galactose. MEMP and purified fractions both had great radicals scavenging activities of hydroxyl and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, and MEMP-2 possessed highest antioxidant activity. The results suggested that MEMP-2 could be the suitable natural antioxidants and may be the functional foods for humans.     

Sequence analysis of the sulfated rhamno-oligosaccharides derived from a sulfated rhamnan

Three sulfated rhamno-oligosaccharides, designated O1, O2 and O3, were obtained by mild acid hydrolysis of the sulfated rhamnan and purified by gel-permeation chromatography. On the basis of one- and two-dimensional nuclear magnetic resonance (1D, 2D NMR) spectroscopic analyses, the oligosaccharide O1 was characterized to be α-l-Rhap-(2SO4)-(1→3)-α-l-Rhap. The fragmentation pattern of the homogeneous disaccharide in the product ion spectra was recognized by negative-ion electrospray tandem mass spectrometry with collision-induced dissociation (ES-CID MS/MS). With the principles established, the sequences of the oligosaccharides O2 and O3 were deduced to be α-l-Rhap-(2SO4)-(1→3)-α-l-Rhap-(1→3)-α-l-Rhap, and α-l-Rhap-(2SO4)-(1→3)-α-l-Rhap-(1→3)-α-l-Rhap-(1→3)-α-l-Rhap (2SO(4)), respectively. The investigation demonstrated that the sulfated rhamnan-derived oligosaccharides were novel sulfated oligosaccharides different from those of other polysaccharides-degraded from algae, and it could be possible to determine the sequence of the sulfated rhamno-oligosaccharides directly from the glycosidic cleavage fragmentation in the product ion spectra.     

Neuroimmune interactions in guinea pig stomach and small intestine

Enteric neuroimmune interactions in gastrointestinal hypersensitivity responses involve antigen detection by mast cells, mast cell degranulation, release of chemical mediators, and modulatory actions of the mediators on the enteric nervous system (ENS). Electrophysiological methods were used to investigate electrical and synaptic behavior of neurons in the stomach and small intestine during exposure to beta-lactoglobulin in guinea pigs sensitized to cow's milk. Application of beta-lactoglobulin to sensitized preparations depolarized the membrane potential and increased neuronal excitability in small intestinal neurons but not in gastric neurons. Effects on membrane potential and excitability in the small intestine were suppressed by the mast cell stabilizing drug ketotifen, the histamine H(2) receptor antagonist cimetidine, the cyclooxygenase inhibitor piroxicam, and the 5-lipoxygenase inhibitor caffeic acid. Unlike small intestinal ganglion cells, gastric myenteric neurons did not respond to histamine applied exogenously. Antigenic exposure suppressed noradrenergic inhibitory neurotransmission in the small intestinal submucosal plexus. The histamine H(3) receptor antagonist thioperamide and piroxicam, but not caffeic acid, prevented the allergic suppression of noradrenergic inhibitory neurotransmission. Antigenic stimulation of neuronal excitability and suppression of synaptic transmission occurred only in milk-sensitized animals. Results suggest that signaling between mast cells and the ENS underlies intestinal, but not gastric, anaphylactic responses associated with food allergies. Histamine, prostaglandins, and leukotrienes are paracrine signals in the communication pathway from mast cells to the small intestinal ENS.     

Identification of favorable SNP alleles and candidate genes responsible for inflorescence-related traits via GWAS in chrysanthemum

Key message

81 SNPs were identified for three inflorescence-related traits, in which 15 were highly favorable. Two dCAPS markers were developed for future MAS breeding, and six candidate genes were predicted.

Abstract

Chrysanthemum is a leading ornamental species worldwide and demonstrates a wealth of morphological variation. Knowledge about the genetic basis of its phenotypic variation for key horticultural traits can contribute to its effective management and genetic improvement. In this study, we conducted a genome-wide association study (GWAS) based on two years of phenotype data and a set of 92,617 single nucleotide polymorphisms (SNPs) using a panel of 107 diverse cut chrysanthemums to dissect the genetic control of three inflorescence-related traits. A total of 81 SNPs were significantly associated with the three inflorescence-related traits (capitulum diameter, number of ray florets and flowering time) in at least one environment, with an individual allele explaining 22.72–38.67% of the phenotypic variation. Fifteen highly favorable alleles were identified for the three target traits by computing the phenotypic effect values for the stable associations detected in 2 year-long trials at each locus. Dosage pyramiding effects of the highly favorable SNP alleles and significant linear correlations between highly favorable allele numbers and corresponding phenotypic performance were observed. Two highly favorable SNP alleles correlating to flowering time and capitulum diameter were converted to derived cleaved amplified polymorphic sequence (dCAPS) markers to facilitate future breeding. Finally, six putative candidate genes were identified that contribute to flowering time and capitulum diameter. These results serve as a foundation for analyzing the genetic mechanisms underlying important horticultural traits and provide valuable insights into molecular marker-assisted selection (MAS) in chrysanthemum breeding programs.

     

Inhibitory neuromuscular transmission mediated by the P2Y1 purinergic receptor in guinea pig small intestine

ATP is a putative inhibitory neurotransmitter responsible for inhibitory junction potentials (IJPs) at neuromuscular junctions (IJPs) in the intestine. This study tested the hypothesis that the purinergic P2Y(1) receptor subtype mediates the IJPs. IJPs were evoked by focal electrical stimulation in the myenteric plexus and recorded with "sharp" intracellular microelectrodes in the circular muscle coat. Stimulation evoked three categories of IJPs: 1) purely purinergic IJPs, 2) partially purinergic IJPs, and 3) nonpurinergic IJPs. Purely purinergic IJPs were suppressed by the selective P2Y(1) purinergic receptor antagonist MRS2179. Purely purinergic IJPs comprised 26% of the IJPs. Partially purinergic IJPs (72% of the IJPs) consisted of a component that was abolished by MRS2179 and a second unaffected component. The MRS2179-insensitive component was suppressed or abolished by inhibition of formation of nitric oxide by N(omega)-nitro-l-arginine methyl ester (l-NAME) in some, but not all, IJPs. An unidentified neurotransmitter, different from nitric oxide, mediated the second component in these cases. Nonpurinergic IJPs were a small third category (4%) of IJPs that were abolished by l-NAME and unaffected by MRS2179. Exogenous application of ATP evoked IJP-like hyperpolarizing responses, which were blocked by MRS2179. Application of apamin, which suppresses opening of small-conductance Ca(2+)-operated K(+) channels in the muscle, decreased the amplitude of the purinergic IJPs and the amplitude of IJP-like responses to ATP. The results support ATP as a neurotransmitter for IJPs in the intestine and are consistent with the hypothesis that the P2Y(1) purinergic receptor subtype mediates the action of ATP.     

Structure-aided optimization of 3-O-β-chacotriosyl ursolic acid as novel H5N1 entry inhibitors with high selective index

Currently, entry inhibitors contribute immensely in developing a new generation of anti-influenza virus drugs. Our earlier studies have identified that 3-O-β-chacotriosyl ursolic acid (1) could inhibit H5N1 pseudovirus by targeting hemagglutinin (HA). In the present study, a series of C-28 modified pentacyclic triterpene saponins via conjugation with a series of amide derivatives were synthesized and their antiviral activities against influenza A/Duck/Guangdong/99 virus (H5N1) in MDCK cells were evaluated. The SARs analysis of these compounds revealed that introduction of certain amide structures at the 17-COOH of ursolic acid could significantly enhance both their antiviral activity and selective index. This study indicated that the attachment of the methoxy group or Cl atom to the phenyl ring at the ortho- or para-position was crucial to improve inhibitory activity. Mechanism studies demonstrated that these title triterpenoids could bind tightly to the viral envelope HA to block the attachment of viruses to host cells, which was consistent with docking studies.     

Multilocus Typing of Enterocytozoon bieneusi in Pig Reveals the High Prevalence,Zoonotic Potential,Host Adaptation and Geographical Segregation in China

Enterocytozoon bieneusi is one of the most frequently diagnosed Microsporidia of humans and most animals. However, there is no information on E. bieneusi infection of pigs in Tibet and Henan, China. In this study, 1,190 fecal samples were collected from pigs in Tibet and Henan and screened for the presence of E. bieneusi. The overall prevalence of E. bieneusi infection was 54.2% (645/1,190), with differences in prevalence observed among geographical areas, ages, and pig breeds. Moreover, 10 E. bieneusi genotypes were identified based on internal transcribed spacer region genotyping, including eight known genotypes (EbpC, EbpA, CHG19, CHC5, Henan‐III, I, D, and H) and two novel genotypes (XZP‐I and XZP‐II). Multilocus sequence typing revealed 18, 7, 17, and 13 genotypes at minisatellite/microsatellite loci MS1, MS3, MS4, and MS7, respectively. Strong linkage disequilibrium (LD) and few numbers of recombination events, suggest a clonal structure of the E. bieneusi population examined in this study. The low pairwise genetic distance (F_ST) and gene flow (Nm) values indicated limited gene flow in the E. bieneusi population from different hosts, with phylogenetic, structure, and median‐joining network analyses all indicating the existence of host and geographical isolation. The identification of isolates belonging to nine human‐pathogenic genotypes indicates that pigs play an important role in the dissemination of E. bieneusi, improving our present understanding of E. bieneusi epidemiology in the studied region.