Cardiac Stomach Research Articles

Molecular and functional characterization of somatostatin-type signalling in a deuterostome invertebrate.

Somatostatin (SS) and allatostatin-C (ASTC) are structurally and evolutionarily related neuropeptides that act as inhibitory regulators of physiological processes in mammals and insects, respectively. Here, we report the first molecular and functional characterization of SS/ASTC-type signalling in a deuterostome invertebrate—the starfish Asterias rubens (phylum Echinodermata). Two SS/ASTC-type precursors were identified in A. rubens (ArSSP1 and ArSSP2) and the structures of neuropeptides derived from these proteins (ArSS1 and ArSS2) were analysed using mass spectrometry. Pharmacological characterization of three cloned A. rubens SS/ASTC-type receptors (ArSSR1–3) revealed that ArSS2, but not ArSS1, acts as a ligand for all three receptors. Analysis of ArSS2 expression in A. rubens using mRNA in situ hybridization and immunohistochemistry revealed stained cells/fibres in the central nervous system, the digestive system (e.g. cardiac stomach) and the body wall and its appendages (e.g. tube feet). Furthermore, in vitro pharmacological tests revealed that ArSS2 causes dose-dependent relaxation of tube foot and cardiac stomach preparations, while injection of ArSS2 in vivo causes partial eversion of the cardiac stomach. Our findings provide new insights into the molecular evolution of SS/ASTC-type signalling in the animal kingdom and reveal an ancient role of SS-type neuropeptides as inhibitory regulators of muscle contractility.

Feeding behavior is the main driver for microparticle intake in mangrove crabs

AbstractAs marine plastic debris is primarily sourced from terrestrial input, coastal environments are particularly affected by deposition. Because of their pneumatophores, mangroves have been recognized for their importance in confining plastic waste. Crabs are a dominant component of the mangrove ecosystem and play a critical role in maintaining healthy and resilient mangrove forests. Therefore, the presence of debris fragmented from waste, in their habitat is a potential threat. However, the potential ingestion of microplastic pieces by mangrove crabs has not yet been investigated. Here, we quantified microparticles found in the cardiac stomachs and gill chambers of four species of crabs. All specimens collected had anthropogenic microparticles present either via their digestive or respiratory systems. We observed significant variability in the abundance and types of anthropogenic microparticles across sites and species. Interspecific differences appear to be explained by their particular feeding habits, with less selective species ingesting more particles.

The effect of diet on the structure of gut bacterial community of sympatric pair of whitefishes (Coregonus lavaretus): one story more.

In the Coregonus lavaretus complex may be found lacustrine sympatric pairs, which serves as an intriguing model for studying different aspects of fish evolutionary biology. One such sympatric whitefish pair inhabits Teletskoye Lake (West Siberia, Russia) and includes a “large” form (Coregonus lavaretus pidschian (Gmelin, 1789)) and a “small” form (C. l. pravdinellus (Dulkeit, 1949)). C. l. pravdinellus has a narrow trophic specialization and feeds on zooplankton, whereas the diet of C. l. pidschian is based on benthic prey. In the present study we aimed to address the question of how the gut microbial community reflects the divergence in diet of a sympatric pair of whitefish. Studied samples included the mucosa and content were collected for cardiac and pyloric stomach, anterior, middle, and posterior intestine, but only mucosa was collected for the pyloric caeca. In addition, water, sediment, macrophyte (environmental microbiota) and invertebrate (microbiota of prey) samples were collected in the same location. The V3–V4 region of the 16S rRNA genes was chosen for microbiome analysis and the software PICRUSt used to estimate the difference functional roles of the microbiota. The number of OTUs and Chao1 index in mucosa and content of cardiac and pyloric stomach were significantly different between whitefish. Significant differences were observed between whitefish for content from different parts of the intestine in terms of OTU number and Chao1 indices, whereas for mucosa from the same parts of intestine these differences were absent. No significant differences were found for diversity estimates of mucosa and content of different parts of the gut (there were a few exceptions) between whitefish. The form of whitefish and the segment of the digestive system were factors with a significant determinative effect on the structure of the microbiota from gut mucosa and content. The most dominant phyla in mucosa and content of cardiac and pyloric stomach was Proteobacteria (57.0–84.0%) for both whitefish. Throughout the intestine of C. l. pidschian the dominant phyla in mucosa were Proteobacteria (38.8%) and Firmicutes (15.6%), whereas for C. l. pravdinellus–Tenericutes (49.6%) and Proteobacteria (28.1%). For both forms, the phylum Spirochaetes was found in a significant amount (20.0–25.0%) in the mucosa of the posterior intestine. While for the content obtained from anterior, middle and posterior intestines, the dominant bacterial phyla were the same as those described for mucosa from the same parts of the intestine for both whitefish. The bacterial community of the prey and environment was significantly different from bacterial communities found for all parts of the gut mucosa for both whitefish, with the exception of the mucosa of the cardiac stomach. According to PICRUSt the highest level of differences between whitefish at the L3 level were found for the intestinal mucosa (75.3%), whereas the lowest one was registered for stomach content (38.8%).

Commentary to article Alexey L. Charyshkin, Evgenii A. Toneev, Alexander A. Martynov, Denis A. Semenov «Surgical treatment of giant GIST of the cardiac stomach»

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Surgical treatment of giant GIST of the cardiac stomach

The article describes the observation of successful radical surgical treatment of a giant gastrointestinal stromal tumor of the cardiac stomach in the patient with concomitant pathology: type 2 diabetes mellitus, insulin-dependent, hypertensive disease of stage 3, severe anemia.

Ancient role of vasopressin/oxytocin-type neuropeptides as regulators of feeding revealed in an echinoderm

BackgroundVasopressin/oxytocin (VP/OT)-type neuropeptides are well known for their roles as regulators of diuresis, reproductive physiology and social behaviour. However, our knowledge of their functions is largely based on findings from studies on vertebrates and selected protostomian invertebrates. Little is known about the roles of VP/OT-type neuropeptides in deuterostomian invertebrates, which are more closely related to vertebrates than protostomes.ResultsHere, we have identified and functionally characterised a VP/OT-type signalling system comprising the neuropeptide asterotocin and its cognate G-protein coupled receptor in the starfish (sea star) Asterias rubens, a deuterostomian invertebrate belonging to the phylum Echinodermata. Analysis of the distribution of asterotocin and the asterotocin receptor in A. rubens using mRNA in situ hybridisation and immunohistochemistry revealed expression in the central nervous system (radial nerve cords and circumoral nerve ring), the digestive system (including the cardiac stomach) and the body wall and associated appendages. Informed by the anatomy of asterotocin signalling, in vitro pharmacological experiments revealed that asterotocin acts as a muscle relaxant in starfish, contrasting with the myotropic actions of VP/OT-type neuropeptides in vertebrates. Furthermore, in vivo injection of asterotocin had a striking effect on starfish behaviour—triggering fictive feeding where eversion of the cardiac stomach and changes in body posture resemble the unusual extra-oral feeding behaviour of starfish.ConclusionsWe provide a comprehensive characterisation of VP/OT-type signalling in an echinoderm, including a detailed anatomical analysis of the expression of both the VP/OT-type neuropeptide asterotocin and its cognate receptor. Our discovery that asterotocin triggers fictive feeding in starfish provides important new evidence of an evolutionarily ancient role of VP/OT-type neuropeptides as regulators of feeding in animals.

Full-length transcriptome analysis of Litopenaeus vannamei reveals transcript variants involved in the innate immune system

To better understand the immune system of shrimp, this study combined PacBio isoform sequencing (Iso-Seq) and Illumina paired-end short reads sequencing methods to discover full-length immune-related molecules of the Pacific white shrimp, Litopenaeus vannamei. A total of 72,648 nonredundant full-length transcripts (unigenes) were generated with an average length of 2545 bp from five main tissues, including the hepatopancreas, cardiac stomach, heart, muscle, and pyloric stomach. These unigenes exhibited a high annotation rate (62,164, 85.57%) when compared against NR, NT, Swiss-Prot, Pfam, GO, KEGG and COG databases. A total of 7544 putative long noncoding RNAs (lncRNAs) were detected and 1164 nonredundant full-length transcripts (449 UniTransModels) participated in the alternative splicing (AS) events. Importantly, a total of 5279 nonredundant full-length unigenes were successfully identified, which were involved in the innate immune system, including 9 immune-related processes, 19 immune-related pathways and 10 other immune-related systems. We also found wide transcript variants, which increased the number and function complexity of immune molecules; for example, toll-like receptors (TLRs) and interferon regulatory factors (IRFs). The 480 differentially expressed genes (DEGs) were significantly higher or tissue-specific expression patterns in the hepatopancreas compared with that in other four tested tissues (FDR <0.05). Furthermore, the expression levels of six selected immune-related DEGs and putative IRFs were validated using real-time PCR technology, substantiating the reliability of the PacBio Iso-seq results. In conclusion, our results provide new genetic resources of long-read full-length transcripts data and information for identifying immune-related genes, which are an invaluable transcriptomic resource as genomic reference, especially for further exploration of the innate immune and defense mechanisms of shrimp.

The role of the transcription factor Sox2 and cytokeratins in the formation and development of the gastroesophageal junction epithelial cell differon

The source of the origin of the epithelium of the cardiac part stomach mucosa has been repeatedly discussed in the literature and different variants of the transformation of the epithelium as manifestation of normal anatomical peculiarities of a man and as a result of changing the program of stem cell differentiation, migration of bone marrow cells, transdifferentiation of simple columnar epithelium have been proposed. Probably it is related to difficulties of studying insignificant in size epithelium of the cardiac mucosa itself and establishment of connection of the duodenogastroesophageal reflux with the development of metaplasia in the epithelium of the terminal department of the esophagus mucosa, which resembles its structure in the cardiac part of the stomach. The purpose of the research was to study the expression of the transcription factor Sox2 and the distribution of cytokeratins in the epithelium of the gastroesophageal zone during the stages of the embryonic and fetal periods of ontogenesis. According to the purpose of the research, an immunohistochemical analysis of the epithelial differon of the esophageal-gastric junction (GEJ) was used. The current study was carried out on 169 human embryos and fetuses of gestational age from 4-5 till 38 weeks. It was established that the transcription factor Sox2 is expressed in basal epitheliocytes of GEJ in all terms of observation and plays a major role in the development, differentiation and formation of the epithelial cell lineage of GEJ. The peculiarity of expression of cytokeratin 7 was positive marking in the cytoplasm of spinosum epitheliocytes, despite the negative expression in the basal layer. It showed weak expression in the epitheliocytes of the esophageal part of the GEJ in the embryonic period with an increased reaction in the embryo-fetal period and with subsequent disappearance, starting at 14 weeks in the early fetal period. For the cardiac mucous membrane GEJ was characterized by its moderate expression on all terms of observation. Cytokeratin 8/18 is embryo-fetal for the esophageal part of the esophagus, as it is defined in early periods of embryogenesis and disappears in the late period (28-38 weeks). For the cardiac mucous membrane GEJ was characterized by its moderate expression on all terms of observation. Cytokeratin 14, unlike CK7 and CK8/18, was localized in the cytoplasm and membranes of basal epitheliocytes of the esophageal part of the mucosa from the 17 gestational weeks and was absent in the gastrointestinal part of the GEJ throughout the prenatal period. Thus, our data on the expression of the transcription factor Sox2 and cytokeratins in the GEJ epithelial differon in the prenatal period of ontogenesis will improve the diagnostic accuracy in determining tissue or organ belonging and can be widely used in various GEJ diseases.

Efficacy of Alginate-Antacid Medication in the Treatment of Patients with Gastroesophageal Reflux Disease

Efficacy of Alginate-Antacid Medication in the Treatment of Patients with Gastroesophageal Reflux Disease

Functional characterization of a second pedal peptide/orcokinin-type neuropeptide signaling system in the starfish Asterias rubens.

Molluscan pedal peptides (PPs) and arthropod orcokinins (OKs) are prototypes of a family of neuropeptides that have been identified in several phyla. Recently, starfish myorelaxant peptide (SMP) was identified as a PP/OK‐type neuropeptide in the starfish Patiria pectinifera (phylum Echinodermata). Furthermore, analysis of transcriptome sequence data from the starfish Asterias rubens revealed two PP/OK‐type precursors: an SMP‐type precursor (A. rubens PP‐like neuropeptide precursor 1; ArPPLNP1) and a second precursor (ArPPLNP2). We reported previously a detailed analysis of ArPPLNP1 expression in A. rubens and here we report the first functional characterization ArPPLNP2‐derived neuropeptides. Sequencing of a cDNA encoding ArPPLNP2 revealed that it comprises eleven related neuropeptides (ArPPLN2a‐k), the structures of several of which were confirmed using mass spectrometry. Analysis of the expression of ArPPLNP2 and neuropeptides derived from this precursor using mRNA in situ hybridization and immunohistochemistry revealed a widespread distribution, including expression in radial nerve cords, circumoral nerve ring, digestive system, tube feet and innervation of interossicular muscles. In vitro pharmacology revealed that the ArPPLNP2‐derived neuropeptide ArPPLN2h has no effect on the contractility of tube feet or the body wall‐associated apical muscle, contrasting with the relaxing effect of ArPPLN1b (ArSMP) on these preparations. ArPPLN2h does, however, cause dose‐dependent relaxation of cardiac stomach preparations, with greater potency/efficacy than ArPPLN1b and with similar potency/efficacy to the SALMFamide neuropeptide S2. In conclusion, there are similarities in the expression patterns of ArPPLNP1 and ArPPLNP2 but our data also indicate specialization in the roles of neuropeptides derived from these two PP/OK‐type precursors in starfish.

Functional Characterization of Paralogous Gonadotropin-Releasing Hormone-Type and Corazonin-Type Neuropeptides in an Echinoderm.

Homologs of the vertebrate neuropeptide gonadotropin-releasing hormone (GnRH) have been identified in invertebrates, including the insect neuropeptide corazonin (CRZ). Recently, we reported the discovery of GnRH-type and CRZ-type signaling systems in an echinoderm, the starfish Asterias rubens, demonstrating that the evolutionary origin of paralogous GnRH-type and CRZ-type neuropeptides can be traced back to the common ancestor of protostomes and deuterostomes. Here, we have investigated the physiological roles of the GnRH-type (ArGnRH) and the CRZ-type (ArCRZ) neuropeptides in A. rubens, using mRNA in situ hybridization, immunohistochemistry and in vitro pharmacology. ArGnRH precursor (ArGnRHP)-expressing cells and ArGnRH-immunoreactive cells and/or processes are present in the radial nerve cords, circumoral nerve ring, digestive system (e.g., cardiac stomach and pyloric stomach), body wall-associated muscle (apical muscle), and appendages (tube feet, terminal tentacle). The general distribution of ArCRZ precursor (ArCRZP)-expressing cells is similar to that of ArGnRHP, but with specific local differences. For example, cells expressing ArGnRHP are present in both the ectoneural and hyponeural regions of the radial nerve cords and circumoral nerve ring, whereas cells expressing ArCRZP were only observed in the ectoneural region. In vitro pharmacological experiments revealed that both ArGnRH and ArCRZ cause contraction of cardiac stomach, apical muscle, and tube foot preparations. However, ArGnRH was more potent/effective than ArCRZ as a contractant of the cardiac stomach, whereas ArCRZ was more potent/effective than ArGnRH as a contractant of the apical muscle. These findings demonstrate that both ArGnRH and ArCRZ are myoexcitatory neuropeptides in starfish, but differences in their expression patterns and pharmacological activities are indicative of distinct physiological roles. This is the first study to investigate the physiological roles of both GnRH-type and CRZ-type neuropeptides in a deuterostome, providing new insights into the evolution and comparative physiology of these paralogous neuropeptide signaling systems in the Bilateria.

Pedal peptide/orcokinin-type neuropeptide signaling in a deuterostome: The anatomy and pharmacology of starfish myorelaxant peptide in Asterias rubens.

Pedal peptide (PP) and orcokinin (OK) are related neuropeptides that were discovered in protostomian invertebrates (mollusks, arthropods). However, analysis of genome/transcriptome sequence data has revealed that PP/OK‐type neuropeptides also occur in a deuterostomian phylum—the echinoderms. Furthermore, a PP/OK‐type neuropeptide (starfish myorelaxant peptide, SMP) was recently identified as a muscle relaxant in the starfish Patiria pectinifera. Here mass spectrometry was used to identify five neuropeptides (ArPPLN1a‐e) derived from the SMP precursor (PP‐like neuropeptide precursor 1; ArPPLNP1) in the starfish Asterias rubens. Analysis of the expression of ArPPLNP1 and neuropeptides derived from this precursor in A. rubens using mRNA in situ hybridization and immunohistochemistry revealed a widespread pattern of expression, with labeled cells and/or processes present in the radial nerve cords, circumoral nerve ring, digestive system (e.g., cardiac stomach) and body wall‐associated muscles (e.g., apical muscle) and appendages (e.g., tube feet and papulae). Furthermore, our data provide the first evidence that neuropeptides are present in the lateral motor nerves and in nerve processes innervating interossicular muscles. In vitro pharmacological tests with SMP (ArPPLN1b) revealed that it causes dose‐dependent relaxation of apical muscle, tube foot and cardiac stomach preparations from A. rubens. Collectively, these anatomical and pharmacological data indicate that neuropeptides derived from ArPPLNP1 act as inhibitory neuromuscular transmitters in starfish, which contrasts with the myoexcitatory actions of PP/OK‐type neuropeptides in protostomian invertebrates. Thus, the divergence of deuterostomes and protostomes may have been accompanied by an inhibitory–excitatory transition in the roles of PP/OK‐type neuropeptides as regulators of muscle activity.

Rodent stomach sample preparation for nitrogen NIRS analysis

Near infrared reflectance spectroscopy is a highly promising method for estimating food quality in small mammals. The method used to prepare rodent stomach content samples, however, may influence nitrogenous substance results. In this study, we focus on comparing methods of preparation of samples and finding the optimal preparation method, which means saving time and costs as well as maintenance of reliability and precision of estimation. We examined 1497 stomachs of the following species: Apodemus flavicollis, A. sylvaticus, Clethrionomys glareolus and Microtus arvalis. We used two preparation methods (grinding and abrasion). Where possible, cardiac and pyloric stomach sections were also examined separately. We found no significant difference between these data, hence only financial, time and equipment factors need determine the processing method in future studies.

Retrosynthesis of CaCO3 via amorphous precursor particles using gastroliths of the Red Claw lobster (Cherax quadricarinatus).

Gastroliths are highly calcified structures formed in the cardiac stomach wall of crustaceans for the temporary storage of amorphous CaCO3 (ACC). The gastrolithic ACC is stabilized by the presence of biomolecules, and represents a novel model for research into biomineralization. For the first time, an in vitro biomimetic retrosynthesis of scaffolds of gastrolithic matrices with CaCO3 is presented. With the help of synthetic polyacrylic (PAA) and phytic (PA) acids, amorphous precursor particles were stabilized in double (DD) and gas (GD) diffusion crystallization assays. The presence of these synthetic molecules as efficient inhibitors of nucleation and growth of CaCO3, and the use of biological gastrolith scaffolds as confined reaction environments determined the kinetics of crystallization, and controlled the morphogenesis of CaCO3. The formation of ACC particles was demonstrated and their crystallization was followed by light microscopy, scanning and transmission electron microscopy, and electron diffraction.

Study on Carapace Width Growth Band Counts Relationship of Orange Mud Crab, Scylla olivacea (Herbst, 1796) from Terengganu Coastal Waters, Malaysia.

Orange mud crab Scylla olivacea is one of the most important fisheries resources. A new development in ageing technique of crustaceans has been introduced. The detection of growth band deposited in hard structure of gastric mill in the cardiac stomach are found retained after moulting process can be used as age indicator and growth estimation. This study was carried out to determine the comparison between carapace width and growth band count of S. olivacea in Malaysia. Samples were collected from Setiu Wetlands, Terengganu, Malaysia from February until August, 2016. Samples were categorized based on their morphological measurements. The mesocardiac and zygocardiac ossicles in the gastric mill of S. olivacea was dissected out and preserved in solutions and underwent a cross sectioning process. A total of 76 of wild S. olivacea ranging from 6.56 to 12.84 cm in carapace width were analysed. The growth band counts were examined for each individual and ranging from 1 to 3 band counts. A positive linear relation was observed between CW and GBC with r2 = 0.5178, p<0.01. Overall, there was a strong, positive correlation between CW and GBC. Increase in CW were correlated with increases in GBC respectively for this species. Therefore, the carapace width, growth band counts and body weight can be used to improve data on growth, recruitment, maturation and mortality. Thus, this study would able to improve new ageing technique and contribute greatly to improve the conservation and management of S. olivacea in Setiu Wetlands, Terengganu, Malaysia.

Reaction of stomach for feeding young pigs probiotics

The basis for the diets of pigs of different technologies of production and productivity in all areas and forage species are of plant origin, which is associated primarily with their availability. This group consists of feed grain cereals, grain legumes, green coarse, juicy, waste flour and other technical industries and others. Although omnivorous pig feed them digestion features displayed on the feasibility of forming foundations diet of concentrated feed. For industrial production of pork proportion of concentrated feed often 100%. However, partly in used feed feeding that are of poor quality, which in turn worsens their nutritional value and complicates digestion and nutrient absorption of food. Besides the low digestibility of grain mixtures in which a third of organic matter is not absorbed by the animals, lack of nutrients adversely affect the resistance and other reactions, reproductive function and performance. Studying the formative influence of the new feed factor on the structure of the digestive system of animals must pay attention to the morphological features of individual organs as the result of direct exposure to chemicals in the diet of the wall of the gastrointestinal tract. The effect of different doses of probiotic preparation Entero–active in growing young pigs on morphological indicators of cardiac, fundic and pyloric stomach areas and established its laws. The data indicate a probable thickening of the stomach wall for probiotic action by thickening muscle and mucous membranes in all investigated areas. The changes have no pathological character, and show an adaptive response to the action of gastric certain doses of the new feed factor.

Histological, surface ultrastructural, and histochemical study of the stomach of red piranha, Pygocentrus nattereri (Kner)

Abstract The structural characterization and function of the stomach in the omnivore Pygocentrus nattereri were described using light and scanning electron microscopy. The sac-like stomach was morphologically divided into the cardiac and pyloric regions. The histological structure of the stomach consisted of four layers of the mucosa, submucosa, muscularis, and serosa. The superficial epithelium of the cardiac stomach was lined with columnar epithelial cells and the glandular epithelium contained numerous gastric glands. Gastric glands were completely absent in the pyloric portion. The mucosal surface of the stomach was a meshwork of various folds, provided with oval or rounded columnar epithelial cells which were densely packed with short, stubby microvilli. The occasional presence of conspicuous gastric pits was surrounded by epithelial cells. The localization and chemical nature of acid and neutral mucins in the various cells of the stomach was studied by employing combined the Alcian Blue-Periodic Acid Schiff (AB-PAS) technique. The deposition of glycogen was detected in the gastric glands as well as in the epithelial lining of the stomach. The utmost reactions for protein and tryptophan were recorded in the gastric glands of mucosa. The cellular organization and histochemical characterization of the stomach are discussed in relation to the feeding and digestion of the fish concerned.

Nucleotide sequence and expression of relaxin-like gonad-stimulating peptide gene in starfish Asterina pectinifera

Starfish gonad-stimulating substance (GSS) is the only known invertebrate peptide hormone responsible for final gamete maturation, rendering it functionally analogous to gonadotropins in vertebrates. Because GSS belongs to the relaxin-like peptide family, we propose renaming for starfish gonadotropic hormone as relaxin-like gonad-stimulating peptide (RGP). This study examined the primary structure and expression regulation of the RGP gene in starfish Asterina pectinifera. RGP consisted of 3896 base pairs (bp) divided over two exons, exon 1 of 208bp and exon 2 of 2277bp, and one intron of 1411bp. Promoter sequences, CAAT and TATA boxes, were present in the 5′-upstream region of the coding DNA sequence of RGP. The transcript was 2485 bases (b) in length. The AAUAAA polyadenylation signal was found in 3′-untranslated region over 2kb away from the stop codon. This showed that only 14% of the RGP mRNA was translated into the peptide, because a size of the open-reading frame was 351 b. Furthermore, an analysis by using real-time quantitative PCR with specific primers for RGP showed that mRNA of RGP was expressed at high levels in the radial nerves. Expression was also observed in the cardiac stomachs, although the level was low, and trace levels were detected in the gonads, pyloric caeca and tube feet. This result suggests that the RGP gene is transcribed mainly in the radial nerves of A. pectinifera.

Abstract 715: Vivo-Morpholino antisense oligomers decrease tumor growth in mice by altering mVEGF mRNA splicing to knock down mVEGF expression

Abstract Vivo-Morpholino antisense oligomers can knock down gene expression by altering splicing of the pre-mRNA and generating a translational frameshift. VEGF overexpression is crucial for tumor growth and anti-VEGF therapies are promising in the treatment of certain cancers. Decreasing VEGF gene expression by exon deletion using Vivo-Morpholinos could suppress tumor growth. We examine the efficiency of mVEGF exon 2 deletion and tumor growth inhibition in mice injected with a Vivo-Morpholino oligomer (VMO-e2i2), which is designed to specifically delete the mVEGF exon 2 and cause downstream frameshifting in mVEGF protein. Mice bearing s.c. Lewis lung carcinoma tumors are I.V. injected with the VMO-e2i2 oligomers at 15mg/kg twice weekly for 2 weeks. VEGF exon 2 deletions are detected by RT-PCR in various tissues tested: approximately 100% exon 2 deletion in kidney, 80% in liver, 70% in skeletal muscles and 40% in s.c. tumors. The tumor volumes decrease by 6 fold over 16 days in mice injected with the VMO-e2i2 oligomers. Exon deletions are detected in various tissues including liver, small intestine, colon, skeletal and cardiac muscles, lung, stomach and kidney. The exon deletion mediated by Vivo-Morpholinos is target specific, dose-dependent and is detectable for more than 15 weeks after a single IV injection in mice. No significant toxicity is observed in mice injected with the effective dosage. Vivo-Morpholinos therefore represent a useful tool for cancer target identification and validation in rodent models and a possible therapeutic treatment. Citation Format: Shan Jiang. Vivo-Morpholino antisense oligomers decrease tumor growth in mice by altering mVEGF mRNA splicing to knock down mVEGF expression. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 715. doi:10.1158/1538-7445.AM2014-715

Structural analysis of the starfish SALMFamide neuropeptides S1 and S2: The N-terminal region of S2 facilitates self-association

The neuropeptides S1 (GFNSALMFamide) and S2 (SGPYSFNSGLTFamide), which share sequence similarity, were discovered in the starfish Asterias rubens and are prototypical members of the SALMFamide family of neuropeptides in echinoderms. SALMFamide neuropeptides act as muscle relaxants and both S1 and S2 cause relaxation of cardiac stomach and tube foot preparations in vitro but S2 is an order of magnitude more potent than S1. Here we investigated a structural basis for this difference in potency using spectroscopic techniques. Circular dichroism spectroscopy showed that S1 does not have a defined structure in aqueous solution and this was supported by 2D nuclear magnetic resonance experiments. In contrast, we found that S2 has a well-defined conformation in aqueous solution. However, the conformation of S2 was concentration dependent, with increasing concentration inducing a transition from an unstructured to a structured conformation. Interestingly, this property of S2 was not observed in an N-terminally truncated analogue of S2 (short S2 or SS2; SFNSGLTFamide). Collectively, the data obtained indicate that the N-terminal region of S2 facilitates peptide self-association at high concentrations, which may have relevance to the biosynthesis and/or bioactivity of S2 in vivo.