scholarly journals Identification of Arenin, a Novel Kunitz-Like Polypeptide from the Skin Secretions of Dryophytes arenicolor

2018 ◽  
Vol 19 (11) ◽  
pp. 3644
Author(s):  
Jesús Hernández-Pérez ◽  
Aida Serra ◽  
Siu Sze ◽  
Patricia Conway ◽  
Jørgen Schlundt ◽  
...  

Amphibian skin secretions are enriched with complex cocktails of bioactive molecules such as proteins, peptides, biogenic amines, alkaloids guanidine derivatives, steroids and other minor components spanning a wide spectrum of pharmacological actions exploited for centuries in folk medicine. This study presents evidence on the protein profile of the skin secretions of the canyon tree frog, Dryophytes arenicolor. At the same time, it presents the reverse-phase liquid chromatography isolation, mass spectrometry characterization and identification at mRNA level of a novel 58 amino acids Kunitz-like polypeptide from the skin secretions of Dryophytes arenicolor, arenin. Cell viability assays performed on HDFa, CaCo2 and MCF7 cells cultured with different concentrations of arenin showed a discrete effect at low concentrations (2, 4, 8 and 16 µg/mL) suggesting a multi-target interaction in a hormetic-like dose-response. Further work is required to investigate the mechanisms underlying the variable effect on cell viability produced by different concentrations of arenin.

1997 ◽  
Vol 50 (9) ◽  
pp. 889 ◽  
Author(s):  
Simon T. Steinborner ◽  
John H. Bowie ◽  
Michael J. Tyler ◽  
John C. Wallace

The dorsal glandular skin extract of the brown tree frog Litoria ewingi contains six major peptides. The amino acid sequences of the peptides were determined by using a combination of mass spectrometry and automated Edman sequencing. One of the peptides, caerin 1.1 [Gly Leu Leu Ser Val Leu Gly Ser Val Ala Lys His Val Leu Pro His Val Val Pro Val Ile Ala Glu His Leu (NH2)], has been isolated previously from Australian tree frogs of the genus Litoria, and is a wide-spectrum antimicrobial agent. The roles of the other five peptides in the amphibian skin have not, as yet, been determined. The most abundant peptide, uperin 7.1 [Gly Trp Phe Asp Val Val Lys His Ile Ala Ser Ala Val (NH2)], shows structural similarity to the uperin group of antimicrobial peptides isolated from toadlets of the genus Uperoleia (except that uperin 7.1 lacks the final four amino acid residues of uperins from the genus Uperoleia). The significance of this finding hinges upon the distant evolutionary relationship of Litoria and Uperoleia. If the structural similarity implies a single evolutionary origin, it also implies a conservation of structural origin for at least 100 million years. Evolutionary convergence is a more likely explanation for the structural similarity of the peptides from the two genera. A related peptide, uperin 7.1.1, lacks the first two amino acid residues from the N-terminal end of uperin 7.1. Uperin 7.1 exhibits minor antimicrobial activity while uperin 7.1.1. is inactive. The three other peptides are caeridin 7.1 [Gly Leu Leu Asp Met Val Thr Gly Leu Leu Gly Asn Leu (NH2)] and two modified peptides of the tryptophyllin group which we have named tryptophyllin 6.1 [Leu Phe Phe Trp Gly (NH2)] and 7.1 [Ile Phe Phe Phe Pro (NH2)]. Tryptophyllins 6.1 and 7.1 are related to similar peptides isolated from the Australian red tree frog Litoria rubella: such peptides may be neurotransmitters or neuromodulators.


2020 ◽  
Vol 20 (4) ◽  
pp. 307-317
Author(s):  
Yuan Yang ◽  
Jin Huang ◽  
Jianzhong Li ◽  
Huansheng Yang ◽  
Yulong Yin

Background: Butyric acid (BT), a short-chain fatty acid, is the preferred colonocyte energy source. The effects of BT on the differentiation, proliferation, and apoptosis of small intestinal epithelial cells of piglets and its underlying mechanisms have not been fully elucidated. Methods: In this study, it was found that 0.2-0.4 mM BT promoted the differentiation of procine jejunal epithelial (IPEC-J2) cells. BT at 0.5 mM or higher concentrations significantly impaired cell viability in a dose- and time-dependent manner. In addition, BT at high concentrations inhibited the IPEC-J2 cell proliferation and induced cell cycle arrest in the G2/M phase. Results: Our results demonstrated that BT triggered IPEC-J2 cell apoptosis via the caspase8-caspase3 pathway accompanied by excess reactive oxygen species (ROS) and TNF-α production. BT at high concentrations inhibited cell autophagy associated with increased lysosome formation. It was found that BT-reduced IPEC-J2 cell viability could be attenuated by p38 MAPK inhibitor SB202190. Moreover, SB202190 attenuated BT-increased p38 MAPK target DDIT3 mRNA level and V-ATPase mRNA level that were responsible for normal acidic lysosomes. Conclusion: In conclusion, 1) at 0.2-0.4 mM, BT promotes the differentiation of IPEC-J2 cells; 2) BT at 0.5 mM or higher concentrations induces cell apoptosis via the p38 MAPK pathway; 3) BT inhibits cells autophagy and promotes lysosome formation at high concentrations.


Open Medicine ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 1061-1069
Author(s):  
Jingjing Zhang ◽  
Yuanyuan Yang ◽  
Hongyu Liu ◽  
Hongyi Hu

Abstract Nasopharyngeal carcinoma (NPC) is characterized by high morbidity and morality, especially in Southern China. Transcription factors intensively participate in the initiation and development of NPC. This study aimed to investigate the roles of Src-1 in NPC. mRNA level was determined by qRT-PCR. Western blot was carried out for the protein level. CCK-8 assay was performed to determine cell viability, colony formation for NPC cell proliferation, and transwell for cell migration and invasion ability. The results showed Steroid receptor coactivator 1 (Src-1) was overexpressed in SNE-2 and 6-10B. The expression of Src-1 and SP2 was in positive correlation. Overexpression of Src-1 promoted the cell viability, colony formation, and epithelial–mesenchymal transition (EMT), manifested by the increase of migration and invasion ability, while knockdown of Src-1 exerted opposite effects. Additionally, knockdown or overexpression of SP2 reversed the effects of overexpressed or downregulated Src-1, which was reversed by the depletion of SP2. Moreover, Src-1 interacted with SP2 to regulate EMT-related genes such as E-cad, N-cad, Vimentin, and ZEB1, and proliferation- and apoptosis-related genes, such as bax, cytochrome c, and cleaved caspase3 and bcl-2. Thus, blocking the interaction between Src-1 and SP2 may be a therapeutic target for inhibiting the metastasis of NPC.


Author(s):  
Gabriela Chabowska ◽  
Helena Moreira ◽  
Beata Tylińska ◽  
Ewa Barg

Background: Despite the dynamic development of medicine, globally cancer diseases remain the second leading cause of death. Therefore, there is a strong necessity to improve chemotherapy regimens and search for new anticancer agents. Pyridocarbazoles are compounds with confirmed antitumor properties based on multimodal mechanisms, i.a. DNA intercalation and topoisomerase II-DNA complex inhibition. One of them, S16020, displayed a wide spectrum of activity. Objective: The aim of the study was to investigate the antitumor potency of six S16020 derivatives, synthesized according to the SAR (structure-activity relationship) method. Methods: The biological evaluation included influence on cancer cell viability, proliferation, and migration, as well as P-glycoprotein activity. NHDF, A549, MCF-7, LoVo, and LoVo/DX cell lines were used in the study. Results: All derivatives displayed low toxicity to normal (NHDF) cells at 1 and 2 µM (≤ 20% of cell growth inhibition). The highest reduction in cell viability was noted in A549 cells which was accompanied by significant disruption of cells proliferation and motility. Compound 1 exhibited the strongest cytotoxic, antiproliferative, and antimigratory effects, higher than the reference olivacine. A significant reduction in P-glycoprotein activity was found for derivatives 6 and 1. Conclusion: S16020 derivatives could be considered as potential candidates for new anticancer drugs.


F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 28
Author(s):  
Yago Queiroz dos Santos ◽  
Gabriella Silva Campos Carelli ◽  
Bruno Oliveira de Veras ◽  
Virgínia Cunha Batista ◽  
Anderson Felipe Jácome de França ◽  
...  

Background: Plant biodiversity has great value for science being an inexhaustible source for new bioactive molecules capable of offering environmentally friendly and innovative solutions for various areas of the industry. The scientific community has increased their interest in the study of plant species in the search of new molecules and to determine their mechanisms of action. Plant seeds are natural sources of bioactive compounds, such as carbohydrates, lipids and proteins with special focus on enzymatic inhibitors which protect them against digestive enzymes of phytopathogens and lectins that play an important role on carbohydrate signalization and metabolism during germination. The objective of the present study was to evaluate and describe the protein profile and to test the hemagglutinating, hemolytic and anticoagulant activities, as well as the antitryptic effect of extracts and fractions obtained from seeds of Eucalyptus species. Methods: The crude protein extract was obtained from the seed of Eucalyptus sp. with 0.02 M sodium phosphate buffer, at pH 6.6, and fractionated using ammonium sulfate in order to study its antitryptical properties as well as the capacity of hemagglutination and influence on hemostasis. Results: The crude extract showed a high effectiveness for trypsin inhibition. For hemagglutinating activity, the ammonium sulfate fraction 0-30% presented better activity, while no hemolytic activity was present in the obtained fractions. For anticoagulation assay, the fraction 0-30% showed better results. Conclusions: Taken together, the obtained results demonstrate the biotechnological potential of Eucalyptus sp. seeds, although further study is still necessary to better isolate as well as describe the bioactive compounds.


2012 ◽  
Vol 54 (2) ◽  
pp. 187-197 ◽  
Author(s):  
Bing Bai ◽  
Yingqi Zhang ◽  
Hui Wang ◽  
Mei Zhou ◽  
Yang Yu ◽  
...  

Antibiotics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 625 ◽  
Author(s):  
Carlos José Correia Santana ◽  
Ana Carolina Martins Magalhães ◽  
Agenor C. M. dos Santos Júnior ◽  
Carlos André Ornelas Ricart ◽  
Beatriz D. Lima ◽  
...  

Amphibian skin secretions are abundant in bioactive compounds, especially antimicrobial peptides. These molecules are generally cationic and rich in hydrophobic amino acids, have an amphipathic structure and adopt an α-helical conformation when in contact with microorganisms membranes. In this work, we purified and characterized Figainin 1, a novel antimicrobial and antiproliferative peptide from the cutaneous secretion of the frog Boana raniceps. Figainin 1 is a cationic peptide with eighteen amino acid residues—rich in leucine and isoleucine, with an amidated C-terminus—and adopts an α-helical conformation in the presence of trifluoroethanol (TFE). It displayed activity against Gram-negative and especially Gram-positive bacteria, with MIC values ranging from 2 to 16 µM, and showed an IC50 value of 15.9 µM against epimastigote forms of T. cruzi; however, Figanin 1 did not show activity against Candida species. This peptide also showed cytolytic effects against human erythrocytes with an HC50 of 10 µM, in addition to antiproliferative activity against cancer cells and murine fibroblasts, with IC50 values ranging from 10.5 to 13.7 µM. Despite its adverse effects on noncancerous cells, Figainin 1 exhibits interesting properties for the development of new anticancer agents and anti-infective drugs against pathogenic microorganisms.


2001 ◽  
Vol 69 (5) ◽  
pp. 3502-3506 ◽  
Author(s):  
Zhongming Ge ◽  
Peter Doig ◽  
James G. Fox

ABSTRACT Helicobacter bilis is a bacterial pathogen associated with multifocal hepatitis and inflammatory bowel disease in certain strains of mice. This bacterium colonizes the liver, bile, and lower intestine in mice and has also been isolated from a wide spectrum of laboratory animals. In this study, proteins present in the outer membrane preparation (OMP) of four H. bilis strains isolated from a mouse, a dog, a rat, and a gerbil were characterized and compared with that of Helicobacter pylori, a human gastric pathogen. All four H. bilis strains had similar OMP protein profiles that were distinct from those of H. pylori. Immunoblotting demonstrated that OMP proteins fromH. bilis and H. pylori have little cross-reactivity, except for their flagellins. Nine major immunogenic polypeptides were present in the H. bilis OMPs. By using two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis, five heat-modifiable proteins with molecular masses of 82, 66, 52, 47 and 37 kDa were identified. The N-terminal sequences of the 46- and 47-kDa OMP proteins had no homology with protein sequences available in public databases. These results indicate that H. bilis has a conserved, unique OMP protein profile that is distinct from those of H. pylori.


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Jinjun Pu ◽  
Shun Zhu ◽  
Dandan Zhou ◽  
Lidong Zhao ◽  
Ming Yin ◽  
...  

Background. The sedative anesthetic, propofol, is a cardioprotective agent for hyperglycemia-induced myocardial hypertrophy and dysfunction in rats. However, the specific protective mechanism has not been clarified. Methods and Results. In this experiment, we used H9c2 cells subjected to 22 mM glucose lasting for 72 hours as an in vitro model of cardiomyocyte injury by hyperglycemia and investigated the potential mechanism of propofol against hyperglycemic stress in cells. Propofol (5, 10, or 20 μM) was added to the cell cultures before and during the high glucose culture phases. Cell viability and levels of ROS were measured. The levels of proinflammatory cytokines were tested by ELISA. The levels of SIRT3, SOD2, PHD2, HIF-1α, Bcl-2, P53, and cleaved caspase-3 proteins were detected by western blotting. Our data showed that propofol attenuated high glucose-induced cell apoptosis accompanied by a decrease in the level of reactive oxygen species (ROS) and proinflammatory cytokines. Meanwhile, propofol decreased the apoptosis of H9c2 cells via increasing the expression of Bcl-2, SIRT3, SOD2, and PHD2 proteins and decreasing the expression of cleaved caspase-3, P53, and HIF-1α. Real-time PCR analysis showed that propofol did not significantly change the HIF-1α but increase PHD2 at mRNA level. HIF-1α silence significantly decreased apoptosis and inflammation in H9c2 cell during high glucose stress. Pretreatment of IOX2 (the inhibitor of PHD2) inhibited cell viability until the concentration reached 200 μM during high glucose stress. However, 50 μM TYP (the inhibitor of SIRT3) significantly inhibited cell viability during high glucose stress. Delayed IOX2 treatment for 6 hours significantly inhibited cell viability during high glucose stress. Conclusions. Propofol might alleviate cell apoptosis via SIRT3-HIF-1α axis during high glucose stress.


Antioxidants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 250 ◽  
Author(s):  
Runqiang Yang ◽  
Qianru Hui ◽  
Qian Jiang ◽  
Shangxi Liu ◽  
Hua Zhang ◽  
...  

Red-osier dogwood, a native species of flowering plant in North America, has been reported to have anti-oxidative properties because of abundant phenolic compounds; this could be promising as a functional food or a feed additive. In the present study, an oxidative damage model using 1.0 mM hydrogen peroxide (H2O2) in Caco-2 cells was established to evaluate the antioxidative effects of red-osier dogwood extracts (RDE). The results showed that 1.0 mM H2O2 pre-exposure for 3 h significantly decreased cell viability, and increased interleukin 8 (IL-8) secretion and the intracellular reactive oxygen species (ROS) level. Caco-2 cells were treated with 100 µg/mL RDE for 24 h after pre-exposure to H2O2. It was found that the decreased cell viability caused by H2O2 was significantly restored by a subsequent 100 µg/mL RDE treatment. Furthermore, the IL-8 secretion and ROS level were significantly blocked by RDE, accompanied by the enhanced gene expression of hemeoxygenase-1 (HO-1), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px), and the enhanced protein expression of the nuclear factor (erythroid-derived 2)-like 2 (Nrf-2). Moreover, RDE improved barrier functions in Caco-2 cells. Using RDE reduced the diffusion of fluorescein isothiocyanate (FITC)-dextran and increased the transepithelial resistance (TEER) value. The relative mRNA level of tight junction claudin-1, claudin-3, and occludin was elevated by RDE. These extracts also repaired the integrity of zonula occludens-1 (ZO-1) damaged by H2O2 and increased the protein expressions of ZO-1 and claudin-3 in the H2O2-pretreated cells. These results illustrated that RDE reduced the ROS level and enhanced the barrier function in oxidative-damaged epithelial cells.


Sign in / Sign up

Export Citation Format

Share Document