Targeting malignant mitochondria with therapeutic peptides

PubMed Central

Constance, Jonathan E; Lim, Carol S

2013-01-01

The current status of peptides that target the mitochondria in the context of cancer is the focus of this review. Chemotherapy and radiotherapy used to kill tumor cells are principally mediated by the process of apoptosis that is governed by the mitochondria. The failure of anticancer therapy often resides at the level of the mitochondria. Therefore, the mitochondrion is a key pharmacological target in cancer due to many of the differences that arise between malignant and healthy cells at the level of this ubiquitous organelle. Additionally, targeting the characteristics of malignant mitochondria often rely on disruption of protein–protein interactions that are not generally amenable to small molecules. We discuss anticancer peptides that intersect with pathological changes in the mitochondrion. PMID:22946430

Virtual screening using combinatorial cyclic peptide libraries reveals protein interfaces readily targetable by cyclic peptides.

PubMed

Duffy, Fergal J; O'Donovan, Darragh; Devocelle, Marc; Moran, Niamh; O'Connell, David J; Shields, Denis C

2015-03-23

Protein-protein and protein-peptide interactions are responsible for the vast majority of biological functions in vivo, but targeting these interactions with small molecules has historically been difficult. What is required are efficient combined computational and experimental screening methods to choose among a number of potential protein interfaces worthy of targeting lead macrocyclic compounds for further investigation. To achieve this, we have generated combinatorial 3D virtual libraries of short disulfide-bonded peptides and compared them to pharmacophore models of important protein-protein and protein-peptide structures, including short linear motifs (SLiMs), protein-binding peptides, and turn structures at protein-protein interfaces, built from 3D models available in the Protein Data Bank. We prepared a total of 372 reference pharmacophores, which were matched against 108,659 multiconformer cyclic peptides. After normalization to exclude nonspecific cyclic peptides, the top hits notably are enriched for mimetics of turn structures, including a turn at the interaction surface of human α thrombin, and also feature several protein-binding peptides. The top cyclic peptide hits also cover the critical "hot spot" interaction sites predicted from the interaction crystal structure. We have validated our method by testing cyclic peptides predicted to inhibit thrombin, a key protein in the blood coagulation pathway of important therapeutic interest, identifying a cyclic peptide inhibitor with lead-like activity. We conclude that protein interfaces most readily targetable by cyclic peptides and related macrocyclic drugs may be identified computationally among a set of candidate interfaces, accelerating the choice of interfaces against which lead compounds may be screened.

Combinatorially Screened Peptide as Targeted Covalent Binder: Alteration of Bait-Conjugated Peptide to Reactive Modifier.

PubMed

Uematsu, Shuta; Tabuchi, Yudai; Ito, Yuji; Taki, Masumi

2018-06-01

A peptide-type covalent binder for a target protein was obtained by combinatorial screening of fluoroprobe-conjugated peptide libraries on bacteriophage T7. The solvatochromic fluoroprobe works as a bait during the affinity selection process of phage display. To obtain the targeted covalent binder, the bait in the selected consensus peptide was altered into a reactive warhead possessing a sulfonyl fluoride. The reaction efficiency and site/position specificity of the covalent conjugation between the binder and the target protein were evaluated by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and rationalized by a protein-ligand docking simulation.

Novel alpha-MSH peptide analogs for melanoma targeting

NASA Astrophysics Data System (ADS)

Flook, Adam Michael

Skin cancer is the one of the most diagnosed cancers in the United States with increasing incidence over the past two decades. There are three major forms of skin cancer but melanoma is the deadliest. It is estimated that 76,690 new diagnoses of melanoma and 9,480 deaths will occur in 2013. Melanoma accounts for approximately 1.6% of all cancer related deaths and is the 5 th leading diagnosed cancer in the United States. The mean survival rate of patients diagnosed with metastatic melanoma is six months, with five year survival rates of less than 5%. In this project, we describe the design and characterization of novel melanoma-targeting peptide analogs for use in diagnostic imaging of both primary and metastatic melanoma lesions. Novel alpha-MSH peptide conjugates were designed to target the melanocortin-1 receptor present and over-expressed on melanoma cells. These peptides were synthesized and their in-vitro melanocortin-1 receptor binding affinities were established in murine melanoma cells. Once binding affinities were determined, the peptides were radiolabeled with 99mTc utilizing a novel direct radiolabeling technique developed in our laboratory. The peptides were purified via reverse-phase high performance liquid chromatography and in-vivo melanoma targeting and pharmacokinetic properties were determined in B16/F1 melanoma-bearing female C57BL/6 mice. Biodistribution and SPECT/CT imaging studies were performed with the promising 99m Tc-labeled peptide conjugates. All alpha-MSH peptide conjugates tested showed low nanomolar binding affinity for the melanocortin-1 receptor. All peptides were readily radiolabeld with 99mTc with greater than 95% radiochemical purity. All 99mTc-labeled peptides displayed high specific in-vivo melanoma tumor uptake while maintaining low normal organ accumulation, and were excreted through the urinary system in a timely fashion. In addition, all tested 99mTc-labeld alpha-MSH peptides demonstrated clear visualization of in

Avidin-Based Targeting and Purification of a Protein IX-Modified, Metabolically Biotinylated Adenoviral Vector

PubMed Central

Campos, Samuel K.; Parrott, M. Brandon; Barry, Michael A.

2014-01-01

While genetic modification of adenoviral vectors can produce vectors with modified tropism, incorporation of targeting peptides/proteins into the structural context of the virion can also result in destruction of ligand targeting or virion integrity. To combat this problem, we have developed a versatile targeting system using metabolically biotinylated adenoviral vectors bearing biotinylated fiber proteins. These vectors have been demonstrated to be useful as a platform for avidin-based ligand screening and vector targeting by conjugating biotinylated ligands to the virus using high-affinity tetrameric avidin (Kd = 10−15 M). The biotinylated vector could also be purified by biotin-reversible binding on monomeric avidin (Kd = 10−7 M). In this report, a second metabolically biotinylated adenovirus vector, Ad-IX-BAP, has been engineered by fusing a biotin acceptor peptide (BAP) to the C-terminus of the adenovirus pIX protein. This biotinylated vector displays twice as many biotins and was markedly superior for single-step affinity purification on monomeric avidin resin. However, unlike the fiber-biotinylated vector, Ad-IX-BAP failed to retarget to cells with biotinylated antibodies including anti-CD71 against the transferrin receptor. In contrast, Ad-IX-BAP was retargeted if transferrin, the cognate ligand for CD71, was used as a ligand rather than the anti-CD71. This work demonstrates the utility of metabolic biotinylation as a molecular screening tool to assess the utility of different viral capsid proteins for ligand display and the biology and compatibility of different ligands and receptors for vector targeting applications. These results also demonstrate the utility of the pIX-biotinylated vector as a platform for gentle single-step affinity purification of adenoviral vectors. PMID:15194061

Antimicrobial Peptides Targeting Gram-Positive Bacteria

PubMed Central

Malanovic, Nermina; Lohner, Karl

2016-01-01

Antimicrobial peptides (AMPs) have remarkably different structures as well as biological activity profiles, whereupon most of these peptides are supposed to kill bacteria via membrane damage. In order to understand their molecular mechanism and target cell specificity for Gram-positive bacteria, it is essential to consider the architecture of their cell envelopes. Before AMPs can interact with the cytoplasmic membrane of Gram-positive bacteria, they have to traverse the cell wall composed of wall- and lipoteichoic acids and peptidoglycan. While interaction of AMPs with peptidoglycan might rather facilitate penetration, interaction with anionic teichoic acids may act as either a trap for AMPs or a ladder for a route to the cytoplasmic membrane. Interaction with the cytoplasmic membrane frequently leads to lipid segregation affecting membrane domain organization, which affects membrane permeability, inhibits cell division processes or leads to delocalization of essential peripheral membrane proteins. Further, precursors of cell wall components, especially the highly conserved lipid II, are directly targeted by AMPs. Thereby, the peptides do not inhibit peptidoglycan synthesis via binding to proteins like common antibiotics, but form a complex with the precursor molecule, which in addition can promote pore formation and membrane disruption. Thus, the multifaceted mode of actions will make AMPs superior to antibiotics that act only on one specific target. PMID:27657092

Proteolysis targeting peptide (PROTAP) strategy for protein ubiquitination and degradation.

PubMed

Zheng, Jing; Tan, Chunyan; Xue, Pengcheng; Cao, Jiakun; Liu, Feng; Tan, Ying; Jiang, Yuyang

2016-02-19

Ubiquitination proteasome pathway (UPP) is the most important and selective way to degrade proteins in vivo. Here, a novel proteolysis targeting peptide (PROTAP) strategy, composed of a target protein binding peptide, a linker and a ubiquitin E3 ligase recognition peptide, was designed to recruit both target protein and E3 ligase and then induce polyubiquitination and degradation of the target protein through UPP. In our study, the PROTAP strategy was proved to be a general method with high specificity using Bcl-xL protein as model target in vitro and in cells, which indicates that the strategy has great potential for in vivo application. Copyright © 2016 Elsevier Inc. All rights reserved.

Enhanced Membrane Pore Formation through High-Affinity Targeted Antimicrobial Peptides

PubMed Central

Arnusch, Christopher J.; Pieters, Roland J.; Breukink, Eefjan

2012-01-01

Many cationic antimicrobial peptides (AMPs) target the unique lipid composition of the prokaryotic cell membrane. However, the micromolar activities common for these peptides are considered weak in comparison to nisin, which follows a targeted, pore-forming mode of action. Here we show that AMPs can be modified with a high-affinity targeting module, which enables membrane permeabilization at low concentration. Magainin 2 and a truncated peptide analog were conjugated to vancomycin using click chemistry, and could be directed towards specific membrane embedded receptors both in model membrane systems and whole cells. Compared with untargeted vesicles, a gain in permeabilization efficacy of two orders of magnitude was reached with large unilamellar vesicles that included lipid II, the target of vancomycin. The truncated vancomycin-peptide conjugate showed an increased activity against vancomycin resistant Enterococci, whereas the full-length conjugate was more active against a targeted eukaryotic cell model: lipid II containing erythrocytes. This study highlights that AMPs can be made more selective and more potent against biological membranes that contain structures that can be targeted. PMID:22768121

N-terminal domain of the dual-targeted pea glutathione reductase signal peptide controls organellar targeting efficiency.

PubMed

Rudhe, Charlotta; Clifton, Rachel; Whelan, James; Glaser, Elzbieta

2002-12-06

Import of nuclear-encoded proteins into mitochondria and chloroplasts is generally organelle specific and its specificity depends on the N-terminal signal peptide. Yet, a group of proteins known as dual-targeted proteins have a targeting peptide capable of leading the mature protein to both organelles. We have investigated the domain structure of the dual-targeted pea glutathione reductase (GR) signal peptide by using N-terminal truncations. A mutant of the GR precursor (pGR) starting with the second methionine residue of the targeting peptide, pGRdelta2-4, directed import into both organelles, negating the possibility that dual import was controlled by the nature of the N terminus. The deletion of the 30 N-terminal residues (pGRdelta2-30) inhibited import efficiency into chloroplasts substantially and almost completely into mitochondria, whereas the removal of only 16 N-terminal amino acid residues (pGRdelta2-16) resulted in the strongly stimulated mitochondrial import without significantly affecting chloroplast import. Furthermore, N-terminal truncations of the signal peptide (pGRdelta2-16 and pGRdelta2-30) greatly stimulated the mitochondrial processing activity measured with the isolated processing peptidase. These results suggest a domain structure for the dual-targeting peptide of pGR and the existence of domains controlling organellar import efficiency therein.

Cell-permeable, mitochondrial-targeted, peptide antioxidants.

PubMed

Szeto, Hazel H

2006-04-21

Cellular oxidative injury has been implicated in aging and a wide array of clinical disorders including ischemia-reperfusion injury; neurodegenerative diseases; diabetes; inflammatory diseases such as atherosclerosis, arthritis, and hepatitis; and drug-induced toxicity. However, available antioxidants have not proven to be particularly effective against many of these disorders. A possibility is that some of the antioxidants do not reach the relevant sites of free radical generation, especially if mitochondria are the primary source of reactive oxygen species (ROS). The SS (Szeto-Schiller) peptide antioxidants represent a novel approach with targeted delivery of antioxidants to the inner mitochondrial membrane. The structural motif of these SS peptides centers on alternating aromatic residues and basic amino acids (aromatic-cationic peptides). These SS peptides can scavenge hydrogen peroxide and peroxynitrite and inhibit lipid peroxidation. Their antioxidant action can be attributed to the tyrosine or dimethyltyrosine residue. By reducing mitochondrial ROS, these peptides inhibit mitochondrial permeability transition and cytochrome c release, thus preventing oxidant-induced cell death. Because these peptides concentrate >1000-fold in the inner mitochondrial membrane, they prevent oxidative cell death with EC50 in the nM range. Preclinical studies support their potential use for ischemia-reperfusion injury and neurodegenerative disorders. Although peptides have often been considered to be poor drug candidates, these small peptides have excellent "druggable" properties, making them promising agents for many diseases with unmet needs.

Engineered Peptides for Applications in Cancer-Targeted Drug Delivery and Tumor Detection.

PubMed

Soudy, R; Byeon, N; Raghuwanshi, Y; Ahmed, S; Lavasanifar, A; Kaur, K

2017-01-01

Cancer-targeting peptides as ligands for targeted delivery of anticancer drugs or drug carriers have the potential to significantly enhance the selectivity and the therapeutic benefit of current chemotherapeutic agents. Identification of tumor-specific biomarkers like integrins, aminopeptidase N, and epidermal growth factor receptor as well as the popularity of phage display techniques along with synthetic combinatorial methods used for peptide design and structure optimization have fueled the advancement and application of peptide ligands for targeted drug delivery and tumor detection in cancer treatment, detection and guided therapy. Although considerable preclinical data have shown remarkable success in the use of tumor targeting peptides, peptides generally suffer from poor pharmacokinetics, enzymatic instability, and weak receptor affinity, and they need further structural modification before successful translation to clinics is possible. The current review gives an overview of the different engineering strategies that have been developed for peptide structure optimization to confer selectivity and stability. We also provide an update on the methods used for peptide ligand identification, and peptide- receptor interactions. Additionally, some applications for the use of peptides in targeted delivery of chemotherapeutics and diagnostics over the past 5 years are summarized. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

PeptidePicker: a scientific workflow with web interface for selecting appropriate peptides for targeted proteomics experiments.

PubMed

Mohammed, Yassene; Domański, Dominik; Jackson, Angela M; Smith, Derek S; Deelder, André M; Palmblad, Magnus; Borchers, Christoph H

2014-06-25

One challenge in Multiple Reaction Monitoring (MRM)-based proteomics is to select the most appropriate surrogate peptides to represent a target protein. We present here a software package to automatically generate these most appropriate surrogate peptides for an LC/MRM-MS analysis. Our method integrates information about the proteins, their tryptic peptides, and the suitability of these peptides for MRM which is available online in UniProtKB, NCBI's dbSNP, ExPASy, PeptideAtlas, PRIDE, and GPMDB. The scoring algorithm reflects our knowledge in choosing the best candidate peptides for MRM, based on the uniqueness of the peptide in the targeted proteome, its physiochemical properties, and whether it previously has been observed. The modularity of the workflow allows further extension and additional selection criteria to be incorporated. We have developed a simple Web interface where the researcher provides the protein accession number, the subject organism, and peptide-specific options. Currently, the software is designed for human and mouse proteomes, but additional species can be easily be added. Our software improved the peptide selection by eliminating human error, considering multiple data sources and all of the isoforms of the protein, and resulted in faster peptide selection - approximately 50 proteins per hour compared to 8 per day. Compiling a list of optimal surrogate peptides for target proteins to be analyzed by LC/MRM-MS has been a cumbersome process, in which expert researchers retrieved information from different online repositories and used their own reasoning to find the most appropriate peptides. Our scientific workflow automates this process by integrating information from different data sources including UniProt, Global Proteome Machine, NCBI's dbSNP, and PeptideAtlas, simulating the researchers' reasoning, and incorporating their knowledge of how to select the best proteotypic peptides for an MRM analysis. The developed software can help to

A Peptide-Based Method for 13C Metabolic Flux Analysis in Microbial Communities

PubMed Central

Ghosh, Amit; Nilmeier, Jerome; Weaver, Daniel; Adams, Paul D.; Keasling, Jay D.; Mukhopadhyay, Aindrila; Petzold, Christopher J.; Martín, Héctor García

2014-01-01

The study of intracellular metabolic fluxes and inter-species metabolite exchange for microbial communities is of crucial importance to understand and predict their behaviour. The most authoritative method of measuring intracellular fluxes, 13C Metabolic Flux Analysis (13C MFA), uses the labeling pattern obtained from metabolites (typically amino acids) during 13C labeling experiments to derive intracellular fluxes. However, these metabolite labeling patterns cannot easily be obtained for each of the members of the community. Here we propose a new type of 13C MFA that infers fluxes based on peptide labeling, instead of amino acid labeling. The advantage of this method resides in the fact that the peptide sequence can be used to identify the microbial species it originates from and, simultaneously, the peptide labeling can be used to infer intracellular metabolic fluxes. Peptide identity and labeling patterns can be obtained in a high-throughput manner from modern proteomics techniques. We show that, using this method, it is theoretically possible to recover intracellular metabolic fluxes in the same way as through the standard amino acid based 13C MFA, and quantify the amount of information lost as a consequence of using peptides instead of amino acids. We show that by using a relatively small number of peptides we can counter this information loss. We computationally tested this method with a well-characterized simple microbial community consisting of two species. PMID:25188426

Effect of structural modification on the gastrointestinal stability and hepatic metabolism of α-aminoxy peptides.

PubMed

Ma, Bin; Yin, Chun; Yang, Dan; Lin, Ge

2012-11-01

α-Aminoxy peptide AxyP1 has been reported to form synthetic chloride channel in living cells, thus it may have therapeutic potential for the treatment of diseases associated with chloride channel dysfunction. However, this study revealed significant gastrointestinal (GI) instability and extensive hepatic metabolism of AxyP1. To improve its GI and metabolic stability, structural modifications were conducted by replacing the isobutyl side chains of AxyP1 with methyl group (AxyP2), hydroxymethyl group (AxyP3), 4-aminobutyl group (AxyP4) and 3-carboxyl propyl group (AxyP5). Compared with AxyP1 (41 and 47 % degradation), GI stability of the modified peptides was significantly improved by 8-fold (AxyP2), 9-fold (AxyP3) and 12-fold (AxyP5) with no degradation for AxyP4 in simulated gastric fluid within 1 h, and by 12-fold (AxyP2) and 9-fold (AxyP3) with no degradation for AxyP4 and AxyP5 in simulated intestinal fluid within 3 h, respectively. The hepatic metabolic stability of the four modified peptides within 30 min in rat liver S9 preparation was also improved significantly with no metabolism of AxyP5 and threefold (AxyP2 and AxyP4) and eightfold (AxyP3) less metabolism compared with AxyP1 (39 % metabolism). Unlike hydrolysis as the major metabolism of peptides of natural α-amino acids, oxidation mediated by the cytochrome P450 enzymes, especially CYP3A subfamily, to form the corresponding mono-hydroxyl metabolites was the predominant hepatic metabolism of the five α-aminoxy peptides tested. The present findings demonstrate that structural modification can significantly improve the GI and metabolic stability of α-aminoxy peptides and thus increase their potential for therapeutic use in the treatment of chloride channel related diseases.

Plastid-targeting peptides from the chlorarachniophyte Bigelowiella natans.

PubMed

Rogers, Matthew B; Archibald, John M; Field, Matthew A; Li, Catherine; Striepen, Boris; Keeling, Patrick J

2004-01-01

Chlorarachniophytes are marine amoeboflagellate protists that have acquired their plastid (chloroplast) through secondary endosymbiosis with a green alga. Like other algae, most of the proteins necessary for plastid function are encoded in the nuclear genome of the secondary host. These proteins are targeted to the organelle using a bipartite leader sequence consisting of a signal peptide (allowing entry in to the endomembrane system) and a chloroplast transit peptide (for transport across the chloroplast envelope membranes). We have examined the leader sequences from 45 full-length predicted plastid-targeted proteins from the chlorarachniophyte Bigelowiella natans with the goal of understanding important features of these sequences and possible conserved motifs. The chemical characteristics of these sequences were compared with a set of 10 B. natans endomembrane-targeted proteins and 38 cytosolic or nuclear proteins, which show that the signal peptides are similar to those of most other eukaryotes, while the transit peptides differ from those of other algae in some characteristics. Consistent with this, the leader sequence from one B. natans protein was tested for function in the apicomplexan parasite, Toxoplasma gondii, and shown to direct the secretion of the protein.

Bioavailability and transport of peptides and peptide drugs into the brain.

PubMed

Egleton, R D; Davis, T P

1997-01-01

Rational drug design and the targeting of specific organs has become a reality in modern drug development, with the emergence of molecular biology and receptor chemistry as powerful tools for the pharmacologist. A greater understanding of peptide function as one of the major extracellular message systems has made neuropeptides an important target in neuropharmaceutical drug design. The major obstacle to targeting the brain with therapeutics is the presence of the blood-brain barrier (BBB), which controls the concentration and entry of solutes into the central nervous system. Peptides are generally polar in nature, do not easily cross the blood-brain barrier by diffusion, and except for a small number do not have specific transport systems. Peptides can also undergo metabolic deactivation by peptidases of the blood, brain and the endothelial cells that comprise the BBB. In this review, we discuss a number of the recent strategies which have been used to promote peptide stability and peptide entry into the brain. In addition, we approach the subject of targeting specific transport systems that can be found on the brain endothelial cells, and describe the limitations of the methodologies that are currently used to study brain entry of neuropharmaceuticals.

Excessive Adiposity and Metabolic Dysfunction Relate to Reduced Natriuretic Peptide During RAAS Activation in HIV.

PubMed

Murphy, Caitlin A; Fitch, Kathleen V; Feldpausch, Meghan; Maehler, Patrick; Wong, Kimberly; Torriani, Martin; Adler, Gail K; Grinspoon, Steven K; Srinivasa, Suman

2018-02-01

Natriuretic peptides (NPs) negatively feedback on the renin-angiotensin-aldosterone system (RAAS) and play a critical role in preserving cardiac structure and maintaining metabolic homeostasis. Well-treated HIV-infected individuals are at risk for fat redistribution and demonstrate evidence of RAAS dysregulation, which relates to metabolic dysfunction. We investigated circulating NPs in relation to RAAS physiology and metrics of body composition for the first time in HIV. We assessed atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and amino terminal pro B-type natriuretic peptide (NT-proBNP) during acute activation of the RAAS using a low sodium controlled diet among 20 HIV-infected and 10 non-HIV-infected individuals well-phenotyped for body composition. BNP(60[44,152] vs. 196[91,251], P=.04) was significantly lower and serum aldosterone higher among HIV-infected vs. non-HIV-infected individuals. BNP was significantly and inversely associated with body composition [waist circumference(r=-0.46, P=.04), BMI(r=-0.55, P=.01), body adiposity index (r=-0.49, P=.03)], metabolic indices [total cholesterol(r=-0.44, P=.05), HOMA-IR(r=-0.44, P=.05), MAP (r=-0.44, P=.05)], and serum aldosterone(r=-0.49,P=.03) among the HIV group. These relationships were not demonstrated in the non-HIV group. In a four-group comparison stratifying by HIV serostatus and above/below BMI 25 kg/m2, BNP decreased significantly across groups, being highest in non-HIV with BMI<25 kg/m2 and lowest in HIV with BMI >25 kg/m2 (overall P=.01). Relatively reduced NP, particularly BNP, among HIV-infected individuals with excess adiposity may contribute to reduced suppression of aldosterone and potentially drive aldosterone-mediated metabolic complications. Novel strategies which target RAAS blockade and/or augment NPs may be potentially useful to reduce cardiometabolic disease among HIV-infected individuals in whom these systems are perturbed. Copyright © 2018 Endocrine Society

Cell targeting peptides as smart ligands for targeting of therapeutic or diagnostic agents: a systematic review.

PubMed

Mousavizadeh, Ali; Jabbari, Ali; Akrami, Mohammad; Bardania, Hassan

2017-10-01

Cell targeting peptides (CTP) are small peptides which have high affinity and specificity to a cell or tissue targets. They are typically identified by using phage display and chemical synthetic peptide library methods. CTPs have attracted considerable attention as a new class of ligands to delivery specifically therapeutic and diagnostic agents, because of the fact they have several advantages including easy synthesis, smaller physical sizes, lower immunogenicity and cytotoxicity and their simple and better conjugation to nano-carriers and therapeutic or diagnostic agents compared to conventional antibodies. In this systematic review, we will focus on the basic concepts concerning the use of cell-targeting peptides (CTPs), following the approaches of selecting them from peptide libraries. We discuss several developed strategies for cell-specific delivery of different cargos by CTPs, which are designed for drug delivery and diagnostic applications. Copyright © 2017 Elsevier B.V. All rights reserved.

A Fluorescent Protein Scaffold for Presenting Structurally Constrained Peptides Provides an Effective Screening System to Identify High Affinity Target-Binding Peptides

PubMed Central

Kadonosono, Tetsuya; Yabe, Etsuri; Furuta, Tadaomi; Yamano, Akihiro; Tsubaki, Takuya; Sekine, Takuya; Kuchimaru, Takahiro; Sakurai, Minoru; Kizaka-Kondoh, Shinae

2014-01-01

Peptides that have high affinity for target molecules on the surface of cancer cells are crucial for the development of targeted cancer therapies. However, unstructured peptides often fail to bind their target molecules with high affinity. To efficiently identify high-affinity target-binding peptides, we have constructed a fluorescent protein scaffold, designated gFPS, in which structurally constrained peptides are integrated at residues K131–L137 of superfolder green fluorescent protein. Molecular dynamics simulation supported the suitability of this site for presentation of exogenous peptides with a constrained structure. gFPS can present 4 to 12 exogenous amino acids without a loss of fluorescence. When gFPSs presenting human epidermal growth factor receptor type 2 (HER2)-targeting peptides were added to the culture medium of HER2-expressing cells, we could easily identify the peptides with high HER2-affinity and -specificity based on gFPS fluorescence. In addition, gFPS could be expressed on the yeast cell surface and applied for a high-throughput screening. These results demonstrate that gFPS has the potential to serve as a powerful tool to improve screening of structurally constrained peptides that have a high target affinity, and suggest that it could expedite the one-step identification of clinically applicable cancer cell-binding peptides. PMID:25084350

Remodeling of Hepatic Metabolism and Hyperaminoacidemia in Mice Deficient in Proglucagon-Derived Peptides

PubMed Central

Watanabe, Chika; Seino, Yusuke; Miyahira, Hiroki; Yamamoto, Michiyo; Fukami, Ayako; Ozaki, Nobuaki; Takagishi, Yoshiko; Sato, Jun; Fukuwatari, Tsutomu; Shibata, Katsumi; Oiso, Yutaka; Murata, Yoshiharu; Hayashi, Yoshitaka

2012-01-01

Glucagon is believed to be one of the most important peptides for upregulating blood glucose levels. However, homozygous glucagon–green fluorescent protein (gfp) knock-in mice (Gcggfp/gfp: GCGKO) are normoglycemic despite the absence of proglucagon-derived peptides, including glucagon. To characterize metabolism in the GCGKO mice, we analyzed gene expression and metabolome in the liver. The expression of genes encoding rate-limiting enzymes for gluconeogenesis was only marginally altered. On the other hand, genes encoding enzymes involved in conversion of amino acids to metabolites available for the tricarboxylic acid cycle and/or gluconeogenesis showed lower expression in the GCGKO liver. The expression of genes involved in the metabolism of fatty acids and nicotinamide was also altered. Concentrations of the metabolites in the GCGKO liver were altered in manners concordant with alteration in the gene expression patterns, and the plasma concentrations of amino acids were elevated in the GCGKO mice. The insulin concentration in serum and phosphorylation of Akt protein kinase in liver were reduced in GCGKO mice. These results indicated that proglucagon-derived peptides should play important roles in regulating various metabolic pathways, especially that of amino acids. Serum insulin concentration is lowered to compensate the impacts of absent proglucagon-derived peptide on glucose metabolism. On the other hand, impacts on other metabolic pathways are only partially compensated by reduced insulin action. PMID:22187375

Correlation of plasma B-type natriuretic peptide levels with metabolic risk markers.

PubMed

Ahued-Ortega, José Armando; León-García, Plácido Enrique; Hernández-Pérez, Elizabeth

2018-04-17

Natriuretic peptide type B (BNP) is a marker of myocardium injury. This peptide has been associated with metabolic risk markers, although controversy exists in this regard. The aim of the present study was to determine the correlation of plasma BNP levels with metabolic risk parameters. A retrospective, observational study that included 152 patients, who were classified according to their clinical diagnosis as patients with metabolic syndrome. Plasma BNP levels and clinical metabolic parameters were assessed by using Spearmańs rank correlation coefficient. A significant inverse association with weight (r=-.408; p<.0001) and BMI (r=-.443; p<.001) was obtained. While a positive significant association with systolic pressure (r=.324; p<.001) was observed. A significant decrease was found in BNP levels and components of metabolic syndrome. (p<.05). Based on the results from this study, we can conclude that BNP determination could be an adequate metabolic marker. Copyright © 2018 Elsevier España, S.L.U. All rights reserved.

Structural specificity of mucosal-cell transport and metabolism of peptide drugs: implication for oral peptide drug delivery

NASA Technical Reports Server (NTRS)

Bai, J. P.; Amidon, G. L.

1992-01-01

The brush border membrane of intestinal mucosal cells contains a peptide carrier system with rather broad substrate specificity and various endo- and exopeptidase activities. Small peptide (di-/tripeptide)-type drugs with or without an N-terminal alpha-amino group, including beta-lactam antibiotics and angiotensin-converting enzyme (ACE) inhibitors, are transported by the peptide transporter. Polypeptide drugs are hydrolyzed by brush border membrane proteolytic enzymes to di-/tripeptides and amino acids. Therefore, while the intestinal brush border membrane has a carrier system facilitating the absorption of di-/tripeptide drugs, it is a major barrier limiting oral availability of polypeptide drugs. In this paper, the specificity of peptide transport and metabolism in the intestinal brush border membrane is reviewed.

Halobacterium salinarum NRC-1 PeptideAtlas: strategies for targeted proteomics

PubMed Central

Van, Phu T.; Schmid, Amy K.; King, Nichole L.; Kaur, Amardeep; Pan, Min; Whitehead, Kenia; Koide, Tie; Facciotti, Marc T.; Goo, Young-Ah; Deutsch, Eric W.; Reiss, David J.; Mallick, Parag; Baliga, Nitin S.

2009-01-01

The relatively small numbers of proteins and fewer possible posttranslational modifications in microbes provides a unique opportunity to comprehensively characterize their dynamic proteomes. We have constructed a Peptide Atlas (PA) for 62.7% of the predicted proteome of the extremely halophilic archaeon Halobacterium salinarum NRC-1 by compiling approximately 636,000 tandem mass spectra from 497 mass spectrometry runs in 88 experiments. Analysis of the PA with respect to biophysical properties of constituent peptides, functional properties of parent proteins of detected peptides, and performance of different mass spectrometry approaches has helped highlight plausible strategies for improving proteome coverage and selecting signature peptides for targeted proteomics. Notably, discovery of a significant correlation between absolute abundances of mRNAs and proteins has helped identify low abundance of proteins as the major limitation in peptide detection. Furthermore we have discovered that iTRAQ labeling for quantitative proteomic analysis introduces a significant bias in peptide detection by mass spectrometry. Therefore, despite identifying at least one proteotypic peptide for almost all proteins in the PA, a context-dependent selection of proteotypic peptides appears to be the most effective approach for targeted proteomics. PMID:18652504

Precision-guided antimicrobial peptide as a targeted modulator of human microbial ecology.

PubMed

Guo, Lihong; McLean, Jeffrey S; Yang, Youngik; Eckert, Randal; Kaplan, Christopher W; Kyme, Pierre; Sheikh, Omid; Varnum, Brian; Lux, Renate; Shi, Wenyuan; He, Xuesong

2015-06-16

One major challenge to studying human microbiome and its associated diseases is the lack of effective tools to achieve targeted modulation of individual species and study its ecological function within multispecies communities. Here, we show that C16G2, a specifically targeted antimicrobial peptide, was able to selectively kill cariogenic pathogen Streptococcus mutans with high efficacy within a human saliva-derived in vitro oral multispecies community. Importantly, a significant shift in the overall microbial structure of the C16G2-treated community was revealed after a 24-h recovery period: several bacterial species with metabolic dependency or physical interactions with S. mutans suffered drastic reduction in their abundance, whereas S. mutans' natural competitors, including health-associated Streptococci, became dominant. This study demonstrates the use of targeted antimicrobials to modulate the microbiome structure allowing insights into the key community role of specific bacterial species and also indicates the therapeutic potential of C16G2 to achieve a healthy oral microbiome.

Targeted delivery of fluorogenic peptide aptamers into live microalgae by femtosecond laser photoporation at single-cell resolution.

PubMed

Maeno, Takanori; Uzawa, Takanori; Kono, Izumi; Okano, Kazunori; Iino, Takanori; Fukita, Keisuke; Oshikawa, Yuki; Ogawa, Taro; Iwata, Osamu; Ito, Takuro; Suzuki, Kengo; Goda, Keisuke; Hosokawa, Yoichiroh

2018-05-29

Microalgae-based metabolic engineering has been proven effective for producing valuable substances such as food supplements, pharmaceutical drugs, biodegradable plastics, and biofuels in the past decade. The ability to accurately visualize and quantify intracellular metabolites in live microalgae is essential for efficient metabolic engineering, but remains a major challenge due to the lack of characterization methods. Here we demonstrate it by synthesizing fluorogenic peptide aptamers with specific binding affinity to a target metabolite and delivering them into live microalgae by femtosecond laser photoporation at single-cell resolution. As a proof-of-principle demonstration of our method, we use it to characterize Euglena gracilis, a photosynthetic unicellular motile microalgal species, which is capable of producing paramylon (a carbohydrate granule similar to starch). Specifically, we synthesize a peptide aptamer containing a paramylon-binding fluorescent probe, 7-nitrobenzofurazan, and introduce it into E. gracilis cells one-by-one by suppressing their mobility with mannitol and transiently perforating them with femtosecond laser pulses at 800 nm for photoporation. To demonstrate the method's practical utility in metabolic engineering, we perform spatially and temporally resolved fluorescence microscopy of single live photoporated E. gracilis cells under different culture conditions. Our method holds great promise for highly efficient microalgae-based metabolic engineering.

Screening and Identification of Peptides Specifically Targeted to Gastric Cancer Cells from a Phage Display Peptide Library

PubMed

Sahin, Deniz; Taflan, Sevket Onur; Yartas, Gizem; Ashktorab, Hassan; Smoot, Duane T

2018-04-25

Background: Gastric cancer is the second most common cancer among the malign cancer types. Inefficiency of traditional techniques both in diagnosis and therapy of the disease makes the development of alternative and novel techniques indispensable. As an alternative to traditional methods, tumor specific targeting small peptides can be used to increase the efficiency of the treatment and reduce the side effects related to traditional techniques. The aim of this study is screening and identification of individual peptides specifically targeted to human gastric cancer cells using a phage-displayed peptide library and designing specific peptide sequences by using experimentally-eluted peptide sequences. Methods: Here, MKN-45 human gastric cancer cells and HFE-145 human normal gastric epithelial cells were used as the target and control cells, respectively. 5 rounds of biopannning with a phage display 12-peptide library were applied following subtraction biopanning with HFE-145 control cells. The selected phage clones were established by enzyme-linked immunosorbent assay and immunofluorescence detection. We first obtain random phage clones after five biopanning rounds, determine the binding levels of each individual clone. Then, we analyze the frequencies of each amino acid in best binding clones to determine positively overexpressed amino acids for designing novel peptide sequences. Results: DE532 (VETSQYFRGTLS) phage clone was screened positive, showing specific binding on MKN-45 gastric cancer cells. DE-Obs (HNDLFPSWYHNY) peptide, which was designed by using amino acid frequencies of experimentally selected peptides in the 5th round of biopanning, showed specific binding in MKN-45 cells. Conclusion: Selection and characterization of individual clones may give us specifically binding peptides, but more importantly, data extracted from eluted phage clones may be used to design theoretical peptides with better binding properties than even experimentally selected ones

Enhancing bioactive peptide release and identification using targeted enzymatic hydrolysis of milk proteins.

PubMed

Nongonierma, Alice B; FitzGerald, Richard J

2018-06-01

Milk proteins have been extensively studied for their ability to yield a range of bioactive peptides following enzymatic hydrolysis/digestion. However, many hurdles still exist regarding the widespread utilization of milk protein-derived bioactive peptides as health enhancing agents for humans. These mostly arise from the fact that most milk protein-derived bioactive peptides are not highly potent. In addition, they may be degraded during gastrointestinal digestion and/or have a low intestinal permeability. The targeted release of bioactive peptides during the enzymatic hydrolysis of milk proteins may allow the generation of particularly potent bioactive hydrolysates and peptides. Therefore, the development of milk protein hydrolysates capable of improving human health requires, in the first instance, optimized targeted release of specific bioactive peptides. The targeted hydrolysis of milk proteins has been aided by a range of in silico tools. These include peptide cutters and predictive modeling linking bioactivity to peptide structure [i.e., molecular docking, quantitative structure activity relationship (QSAR)], or hydrolysis parameters [design of experiments (DOE)]. Different targeted enzymatic release strategies employed during the generation of milk protein hydrolysates are reviewed herein and their limitations are outlined. In addition, specific examples are provided to demonstrate how in silico tools may help in the identification and discovery of potent milk protein-derived peptides. It is anticipated that the development of novel strategies employing a range of in silico tools may help in the generation of milk protein hydrolysates containing potent and bioavailable peptides, which in turn may be used to validate their health promoting effects in humans. Graphical abstract The targeted enzymatic hydrolysis of milk proteins may allow the generation of highly potent and bioavailable bioactive peptides.

Intravenous phage display identifies peptide sequences that target the burn-injured intestine.

PubMed

Costantini, Todd W; Eliceiri, Brian P; Putnam, James G; Bansal, Vishal; Baird, Andrew; Coimbra, Raul

2012-11-01

The injured intestine is responsible for significant morbidity and mortality after severe trauma and burn; however, targeting the intestine with therapeutics aimed at decreasing injury has proven difficult. We hypothesized that we could use intravenous phage display technology to identify peptide sequences that target the injured intestinal mucosa in a murine model, and then confirm the cross-reactivity of this peptide sequence with ex vivo human gut. Four hours following 30% TBSA burn we performed an in vivo, intravenous systemic administration of phage library containing 10(12) phage in balb/c mice to biopan for gut-targeting peptides. In vivo assessment of the candidate peptide sequences identified after 4 rounds of internalization was performed by injecting 1×10(12) copies of each selected phage clone into sham or burned animals. Internalization into the gut was assessed using quantitative polymerase chain reaction. We then incubated this gut-targeting peptide sequence with human intestine and visualized fluorescence using confocal microscopy. We identified 3 gut-targeting peptide sequences which caused collapse of the phage library (4-1: SGHQLLLNKMP, 4-5: ILANDLTAPGPR, 4-11: SFKPSGLPAQSL). Sequence 4-5 was internalized into the intestinal mucosa of burned animals 9.3-fold higher than sham animals injected with the same sequence (2.9×10(5)vs. 3.1×10(4) particles per mg tissue). Sequences 4-1 and 4-11 were both internalized into the gut, but did not demonstrate specificity for the injured mucosa. Phage sequence 4-11 demonstrated cross-reactivity with human intestine. In the future, this gut-targeting peptide sequence could serve as a platform for the delivery of biotherapeutics. Copyright © 2012 Elsevier Inc. All rights reserved.

M13 phage peptide ZL4 exerts its targeted binding effect on schistosoma japonicum via alkaline phosphatase.

PubMed

Liu, Yan; Yang, Shenghui; Xiao, Jianhua; Yu, Liang; Chen, Li; Zou, Ju; Wang, Kegeng; Tan, Sijie; Yu, Zhengyang; Zeng, Qingren

2015-01-01

The present study was to determine the targeting effect of M13 phage peptide ZL4 (MppZL4) on Schistosoma japonicum (S.j). Mice infected with S.j were injected with MppZL4. Real-time PCR was used to detect the distribution and metabolism of MppZL4 in the livers and lungs of mice. In vivo refusion test was performed to detect the targeting of MppZL4. Western blotting was employed to determine the expression of MppZL4. Live imaging was used to detect the distribution of oligopeptide MppZL4. Immunohistochemistry was employed to determine MppZL4 location on adult S.j body surface. Gomori method was employed to detect the influence of oligopeptide MppZL4 on alkaline phosphatase activity. The distribution and metabolism of MppZL4 and M13KE are not significantly different from each other at each time point. The abundance of MppZL4 is changed as S.j migrates in mice. The targeted binding effect of MppZL4 varies at different stages. ZL4 oligopeptide targets S.j in mice. The specific binding sites of MppZL4 on S.j body are mainly located in syncytial cells. The binding sites of MppZL4 on S.j body surface might be ALP or ALP-related proteins. MppZL4 had targeted binding effect on S.j with its binding site being associated with proteins related to S.j alkaline phosphatase. S.j tegument had a specifically binding site with exogenous peptides, offering new means to explore the interactions between hosts and parasites. Additionally, MppZL4 can possibly be used as targeting molecules in worm-resistant drugs or as tracing molecules in imaging diagnosis technologies.

Highly multiplexed targeted proteomics using precise control of peptide retention time.

PubMed

Gallien, Sebastien; Peterman, Scott; Kiyonami, Reiko; Souady, Jamal; Duriez, Elodie; Schoen, Alan; Domon, Bruno

2012-04-01

Large-scale proteomics applications using SRM analysis on triple quadrupole mass spectrometers present new challenges to LC-MS/MS experimental design. Despite the automation of building large-scale LC-SRM methods, the increased numbers of targeted peptides can compromise the balance between sensitivity and selectivity. To facilitate large target numbers, time-scheduled SRM transition acquisition is performed. Previously published results have demonstrated incorporation of a well-characterized set of synthetic peptides enabled chromatographic characterization of the elution profile for most endogenous peptides. We have extended this application of peptide trainer kits to not only build SRM methods but to facilitate real-time elution profile characterization that enables automated adjustment of the scheduled detection windows. Incorporation of dynamic retention time adjustments better facilitate targeted assays lasting several days without the need for constant supervision. This paper provides an overview of how the dynamic retention correction approach identifies and corrects for commonly observed LC variations. This adjustment dramatically improves robustness in targeted discovery experiments as well as routine quantification experiments. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Therapeutic potential of peptide toxins that target ion channels.

PubMed

Beraud, Evelyne; Chandy, K George

2011-10-01

Traditional healthcare systems in China, India, Greece and the Middle East have for centuries exploited venomous creatures as a resource for medicines. This review focuses on one class of pharmacologically active compounds from venom, namely peptide toxins that target ion channels. We highlight their therapeutic potential and the specific channels they target. The field of therapeutic application is vast, including pain, inflammation, cancer, neurological disorders, cardioprotection, and autoimmune diseases. One of these peptides is in clinical use, and many others are in various stages of pre-clinical and clinical development.

EDB Fibronectin Specific Peptide for Prostate Cancer Targeting.

PubMed

Han, Zheng; Zhou, Zhuxian; Shi, Xiaoyue; Wang, Junpeng; Wu, Xiaohui; Sun, Da; Chen, Yinghua; Zhu, Hui; Magi-Galluzzi, Cristina; Lu, Zheng-Rong

2015-05-20

Extradomain-B fibronectin (EDB-FN), one of the oncofetal fibronectin (onfFN) isoforms, is a high-molecular-weight glycoprotein that mediates cell adhesion and migration. The expression of EDB-FN is associated with a number of cancer-related biological processes such as tumorigenesis, angiogenesis, and epithelial-to-mesenchymal transition (EMT). Here, we report the development of a small peptide specific to EDB-FN for targeting prostate cancer. A cyclic nonapeptide, CTVRTSADC (ZD2), was identified using peptide phage display. A ZD2-Cy5 conjugate was synthesized to accomplish molecular imaging of prostate cancer in vitro and in vivo. ZD2-Cy5 demonstrated effective binding to up-regulated EDB-FN secreted by TGF-β-induced PC3 cancer cells following EMT. Following intravenous injections, the targeted fluorescent probe specifically bound to and delineated PC3-GFP prostate tumors in nude mice bearing the tumor xenografts. ZD2-Cy5 also showed stronger binding to human prostate tumor specimens with a higher Gleason score (GS9) compared to those with a lower score (GS 7), with no binding in benign prostatic hyperplasia (BPH). Thus, the ZD2 peptide is a promising strategy for molecular imaging and targeted therapy of prostate cancer.

An optimized transit peptide for effective targeting of diverse foreign proteins into chloroplasts in rice.

PubMed

Shen, Bo-Ran; Zhu, Cheng-Hua; Yao, Zhen; Cui, Li-Li; Zhang, Jian-Jun; Yang, Cheng-Wei; He, Zheng-Hui; Peng, Xin-Xiang

2017-04-11

Various chloroplast transit peptides (CTP) have been used to successfully target some foreign proteins into chloroplasts, but for other proteins these same CTPs have reduced localization efficiencies or fail completely. The underlying cause of the failures remains an open question, and more effective CTPs are needed. In this study, we initially observed that two E.coli enzymes, EcTSR and EcGCL, failed to be targeted into rice chloroplasts by the commonly-used rice rbcS transit peptide (rCTP) and were subsequently degraded. Further analyses revealed that the N-terminal unfolded region of cargo proteins is critical for their localization capability, and that a length of about 20 amino acids is required to attain the maximum localization efficiency. We considered that the unfolded region may alleviate the steric hindrance produced by the cargo protein, by functioning as a spacer to which cytosolic translocators can bind. Based on this inference, an optimized CTP, named RC2, was constructed. Analyses showed that RC2 can more effectively target diverse proteins, including EcTSR and EcGCL, into rice chloroplasts. Collectively, our results provide further insight into the mechanism of CTP-mediated chloroplastic localization, and more importantly, RC2 can be widely applied in future chloroplastic metabolic engineering, particularly for crop plants.

Oligo-branched peptides for tumor targeting: from magic bullets to magic forks.

PubMed

Falciani, Chiara; Pini, Alessandro; Bracci, Luisa

2009-02-01

Selective targeting of tumor cells is the final goal of research and drug discovery for cancer diagnosis, imaging and therapy. After the invention of hybridoma technology, the concept of magic bullet was introduced into the field of oncology, referring to selective killing of tumor cells, by specific antibodies. More recently, small molecules and peptides have also been proposed as selective targeting agents. We analyze the state of the art of tumor-selective agents that are presently available and tested in clinical settings. A novel approach based on 'armed' oligo-branched peptides as tumor targeting agents, is discussed and compared with existing tumor-selective therapies mediated by antibodies, small molecules or monomeric peptides. Oligo-branched peptides could be novel drugs that combine the advantages of antibodies and small molecules.

Orally active-targeted drug delivery systems for proteins and peptides.

PubMed

Li, Xiuying; Yu, Miaorong; Fan, Weiwei; Gan, Yong; Hovgaard, Lars; Yang, Mingshi

2014-09-01

In the past decade, extensive efforts have been devoted to designing 'active targeted' drug delivery systems (ATDDS) to improve oral absorption of proteins and peptides. Such ATDDS enhance cellular internalization and permeability of proteins and peptides via molecular recognition processes such as ligand-receptor or antigen-antibody interaction, and thus enhance drug absorption. This review focuses on recent advances with orally ATDDS, including ligand-protein conjugates, recombinant ligand-protein fusion proteins and ligand-modified carriers. In addition to traditional intestinal active transport systems of substrates and their corresponding receptors, transporters and carriers, new targets such as intercellular adhesion molecule-1 and β-integrin are also discussed. ATDDS can improve oral absorption of proteins and peptides. However, currently, no clinical studies on ATDDS for proteins and peptides are underway, perhaps due to the complexity and limited knowledge of transport mechanisms. Therefore, more research is warranted to optimize ATDDS efficiency.

Self-assembled peptide-based nanostructures: Smart nanomaterials toward targeted drug delivery.

PubMed

Habibi, Neda; Kamaly, Nazila; Memic, Adnan; Shafiee, Hadi

2016-02-01

Self-assembly of peptides can yield an array of well-defined nanostructures that are highly attractive nanomaterials for many biomedical applications such as drug delivery. Some of the advantages of self-assembled peptide nanostructures over other delivery platforms include their chemical diversity, biocompatibility, high loading capacity for both hydrophobic and hydrophilic drugs, and their ability to target molecular recognition sites. Furthermore, these self-assembled nanostructures could be designed with novel peptide motifs, making them stimuli-responsive and achieving triggered drug delivery at disease sites. The goal of this work is to present a comprehensive review of the most recent studies on self-assembled peptides with a focus on their "smart" activity for formation of targeted and responsive drug-delivery carriers.

The unique peptidome: Taxon-specific tryptic peptides as biomarkers for targeted metaproteomics.

PubMed

Mesuere, Bart; Van der Jeugt, Felix; Devreese, Bart; Vandamme, Peter; Dawyndt, Peter

2016-09-01

The Unique Peptide Finder (http://unipept.ugent.be/peptidefinder) is an interactive web application to quickly hunt for tryptic peptides that are unique to a particular species, genus, or any other taxon. Biodiversity within the target taxon is represented by a set of proteomes selected from a monthly updated list of complete and nonredundant UniProt proteomes, supplemented with proprietary proteomes loaded into persistent local browser storage. The software computes and visualizes pan and core peptidomes as unions and intersections of tryptic peptides occurring in the selected proteomes. In addition, it also computes and displays unique peptidomes as the set of all tryptic peptides that occur in all selected proteomes but not in any UniProt record not assigned to the target taxon. As a result, the unique peptides can serve as robust biomarkers for the target taxon, for example, in targeted metaproteomics studies. Computations are extremely fast since they are underpinned by the Unipept database, the lowest common ancestor algorithm implemented in Unipept and modern web technologies that facilitate in-browser data storage and parallel processing. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Brain Natriuretic Peptide Stimulates Lipid Metabolism through Its Receptor NPR1 and the Glycerolipid Metabolism Pathway in Chicken Adipocytes.

PubMed

Huang, H Y; Zhao, G P; Liu, R R; Li, Q H; Zheng, M Q; Li, S F; Liang, Z; Zhao, Z H; Wen, J

2015-11-03

Brain natriuretic peptide (BNP) is related to lipid metabolism in mammals, but its effect and the molecular mechanisms underlying it in chickens are incompletely understood. We found that the level of natriuretic peptide precursor B (NPPB, which encodes BNP) mRNA expression in high-abdominal-fat chicken groups was significantly higher than that of low-abdominal-fat groups. Partial correlations indicated that changes in the weight of abdominal fat were positively correlated with NPPB mRNA expression level. In vitro, compared with the control group, preadipocytes with NPPB interference showed reduced levels of proliferation, differentiation, and glycerin in media. Treatments of cells with BNP led to enhanced proliferation and differentiation of cells and glycerin concentration, and mRNA expression of its receptor natriuretic peptide receptor 1 (NPR1) was upregulated significantly. In cells exposed to BNP, 482 differentially expressed genes were identified compared with controls without BNP. Four genes known to be related to lipid metabolism (diacylglycerol kinase; lipase, endothelial; 1-acylglycerol-3-phosphate O-acyltransferase 1; and 1-acylglycerol-3-phosphate O-acyltransferase 2) were enriched in the glycerolipid metabolism pathway and expressed differentially. In conclusion, BNP stimulates the proliferation, differentiation, and lipolysis of preadipocytes through upregulation of the levels of expression of its receptor NPR1 and key genes enriched in the glycerolipid metabolic pathway.

Dual peptide conjugation strategy for improved cellular uptake and mitochondria targeting.

PubMed

Lin, Ran; Zhang, Pengcheng; Cheetham, Andrew G; Walston, Jeremy; Abadir, Peter; Cui, Honggang

2015-01-21

Mitochondria are critical regulators of cellular function and survival. Delivery of therapeutic and diagnostic agents into mitochondria is a challenging task in modern pharmacology because the molecule to be delivered needs to first overcome the cell membrane barrier and then be able to actively target the intracellular organelle. Current strategy of conjugating either a cell penetrating peptide (CPP) or a subcellular targeting sequence to the molecule of interest only has limited success. We report here a dual peptide conjugation strategy to achieve effective delivery of a non-membrane-penetrating dye 5-carboxyfluorescein (5-FAM) into mitochondria through the incorporation of both a mitochondrial targeting sequence (MTS) and a CPP into one conjugated molecule. Notably, circular dichroism studies reveal that the combined use of α-helix and PPII-like secondary structures has an unexpected, synergistic contribution to the internalization of the conjugate. Our results suggest that although the use of positively charged MTS peptide allows for improved targeting of mitochondria, with MTS alone it showed poor cellular uptake. With further covalent linkage of the MTS-5-FAM conjugate to a CPP sequence (R8), the dually conjugated molecule was found to show both improved cellular uptake and effective mitochondria targeting. We believe these results offer important insight into the rational design of peptide conjugates for intracellular delivery.

Serum Peptide Changes in Chickens with Metabolic Skeletal Problems Associated with Lameness

NASA Astrophysics Data System (ADS)

Rasaputra, Komal S.; Liyanage, Rohana; Okimoto, Ron; Lay, Jackson O.; Rath, Narayan C.

2011-06-01

Serum proteins and peptides have potential as biomarkers since they form the structural and functional basis of tissues and are involved in metabolic and regulatory processes. Changes in their profiles or their breakdown products have been of interest as potential biomarkers. Tibial dyschondroplasia (TD) and femoral head separation (FHS) are two metabolic skeletal problems in poultry that cause lameness. The objective of this study was to identify serum peptide changes associated with lameness in poultry that may be predictive of the disease and may help in eliminating these hereditary defects from the genetic pool. Serum peptides were extracted from six-wk-old chickens with or without the above leg problems using C18 magnetic beads and analyzed by MALDI-TOF mass spectrometry. Differentially expressed peptides were analyzed in the m/z range of 1,000-10,000 using ClinproTool™ software. Twenty two peaks from TD and 20 from FHS affected chickens were compared with their respective controls. The spectral peaks were identified using mass spectrometry followed by a data base search. Some of the peptides identified were hemostasis associated breakdown products. No differentially expressed peptide was detected in FHS but a peptide with m/z 5308.1 was elevated in chickens with TD (p⩽0.05). It was identified as a fragment of alpha 1 type-XI isoform 1. Type XI collagen is a cartilage specific extracellular matrix protein that is involved in the organization of other collagens and maintains extracellular matrix integrity. Its breakdown product may indicate cartilage degeneration in tibial dyschondroplasia thus may serve as a surrogate marker for this problem.

Targeted Killing of Streptococcus mutans by a Pheromone-Guided “Smart” Antimicrobial Peptide

PubMed Central

Eckert, Randal ; He, Jian; Yarbrough, Daniel K.; Qi, Fengxia; Anderson, Maxwell H.; Shi, Wenyuan

2006-01-01

Within the repertoire of antibiotics available to a prescribing clinician, the majority affect a broad range of microorganisms, including the normal flora. The ecological disruption resulting from antibiotic treatment frequently results in secondary infections or other negative clinical consequences. To address this problem, our laboratory has recently developed a new class of pathogen-selective molecules, called specifically (or selectively) targeted antimicrobial peptides (STAMPs), based on the fusion of a species-specific targeting peptide domain with a wide-spectrum antimicrobial peptide domain. In the current study, we focused on achieving targeted killing of Streptococcus mutans, a cavity-causing bacterium that resides in a multispecies microbial community (dental plaque). In particular, we explored the possibility of utilizing a pheromone produced by S. mutans, namely, the competence stimulating peptide (CSP), as a STAMP targeting domain to mediate S. mutans-specific delivery of an antimicrobial peptide domain. We discovered that STAMPs constructed with peptides derived from CSP were potent against S. mutans grown in liquid or biofilm states but did not affect other oral streptococci tested. Further studies showed that an 8-amino-acid region within the CSP sequence is sufficient for targeted delivery of the antimicrobial peptide domain to S. mutans. The STAMPs presented here are capable of eliminating S. mutans from multispecies biofilms without affecting closely related noncariogenic oral streptococci, indicating the potential of these molecules to be developed into “probiotic” antibiotics which could selectively eliminate pathogens while preserving the protective benefits of a healthy normal flora. PMID:17060534

Targeting bacterial central metabolism for drug development.

PubMed

Murima, Paul; McKinney, John D; Pethe, Kevin

2014-11-20

Current antibiotics, derived mainly from natural sources, inhibit a narrow spectrum of cellular processes, namely DNA replication, protein synthesis, and cell wall biosynthesis. With the worldwide explosion of drug resistance, there is renewed interest in the investigation of alternate essential cellular processes, including bacterial central metabolic pathways, as a drug target space for the next generation of antibiotics. However, the validation of targets in central metabolism is more complex, as essentiality of such targets can be conditional and/or contextual. Bearing in mind our enhanced understanding of prokaryotic central metabolism, a key question arises: can central metabolism be bacteria's Achilles' heel and a therapeutic target for the development of new classes of antibiotics? In this review, we draw lessons from oncology and attempt to address some of the open questions related to feasibility of targeting bacterial central metabolism as a strategy for developing new antibacterial drugs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Metabolism of growth hormone releasing peptides.

PubMed

Thomas, Andreas; Delahaut, Philippe; Krug, Oliver; Schänzer, Wilhelm; Thevis, Mario

2012-12-04

New, potentially performance enhancing compounds have frequently been introduced to licit and illicit markets and rapidly distributed via worldwide operating Internet platforms. Developing fast analytical strategies to follow these new trends is one the most challenging issues for modern doping control analysis. Even if reference compounds for the active drugs are readily obtained, their unknown metabolism complicates effective testing strategies. Recently, a new class of small C-terminally amidated peptides comprising four to seven amino acid residues received considerable attention of sports drug testing authorities due to their ability to stimulate growth hormone release from the pituitary. The most promising candidates are the growth hormone releasing peptide (GHRP)-1, -2, -4, -5, -6, hexarelin, alexamorelin, and ipamorelin. With the exemption of GHRP-2, the entity of these peptides represents nonapproved pharmaceuticals; however, via Internet providers, all compounds are readily available. To date, only limited information on the metabolism of these substances is available and merely one metabolite for GHRP-2 is established. Therefore, a comprehensive in vivo (po and iv administration in rats) and in vitro (with human serum and recombinant amidase) study was performed in order to generate information on urinary metabolites potentially useful for routine doping controls. The urine samples from the in vivo experiments were purified by mixed-mode cation-exchange solid-phase extraction and analyzed by ultrahigh-performance liquid chromatography (UHPLC) separation followed by high-resolution/high-accuracy mass spectrometry. Combining the high resolution power of a benchtop Orbitrap mass analyzer for the first metabolite screening and the speed of a quadrupole/time-of-flight (Q-TOF) instrument for identification, urinary metabolites were screened by means of a sensitive full scan analysis and subsequently confirmed by high-accuracy product ion scan experiments. Two

Collagen like peptide bioconjugates for targeted drug delivery applications

NASA Astrophysics Data System (ADS)

Luo, Tianzhi

the coil/globule conformational transition of the PDEGMEMA building block above its LCST with stabilization of the nanostructures by the hydrophilic CLP. To the best of our knowledge, this is the first report on such assembled nanostructures from collagen-like peptide containing copolymers. Due to the strong propensity for CLPs to bind to natural collagen via strand invasion processes, these nanosized vesicles may be used as drug carriers for targeted delivery. In addition to synthetic polymers, the collagen like peptide is then conjugated with a thermoresponsive elastin-like peptide (ELP). The resulting ELP-CLP diblock conjugates show a remarkable reduction in the inverse transition temperature of the ELP domain, attributed to the anchoring effect of the CLP triple helix. The lower transition temperature of the conjugate enables facile formation of well-defined vesicles at physiological temperature and the unexpected resolubilization of the vesicles at elevated temperatures upon unfolding of the CLP domain. Given the ability of CLPs to modify collagens, this work provides not only a simple and versatile avenue for controlling the inverse transition behavior of elastin-like peptides, but also suggest future opportunities for these thermoresponsive nanostructures in biologically relevant environments. In the last section, the potential of using the ELP-CLP nanoparticles as drug delivery vehicles for targeting collagen containing matrices is evaluated. A sustained release of clinically relevant amount of encapsulated modelled drug is achieved within three weeks, followed by a thermally controlled burst release. As expected, the ELP-CLP nanoparticles show strong retention on collagen substrate, via specific binding through collagen triple helix hybridization. Additionally, cell viability and proliferation studies using fibroblasts and chondrocytes suggest the nanoparticles are non-cytotoxic. Additionally, almost no TNF-alpha expression from macrophages is observed

Recent developments in anticancer drug delivery using cell penetrating and tumor targeting peptides.

PubMed

Dissanayake, Shama; Denny, William A; Gamage, Swarna; Sarojini, Vijayalekshmi

2017-03-28

Efficient intracellular trafficking and targeted delivery to the site of action are essential to overcome the current drawbacks of cancer therapeutics. Cell Penetrating Peptides (CPPs) offer the possibility of efficient intracellular trafficking, and, therefore the development of drug delivery systems using CPPs as cargo carriers is an attractive strategy to address the current drawbacks of cancer therapeutics. Additionally, the possibility of incorporating Tumor Targeting Peptides (TTPs) into the delivery system provides the necessary drug targeting effect. Therefore the conjugation of CPPs and/or TTPs with therapeutics provides a potentially efficient method of improving intracellular drug delivery mechanisms. Peptides used as cargo carriers in DDS have been shown to enhance the cellular uptake of drugs and thereby provide an efficient therapeutic benefit over the drug on its own. After providing a brief overview of various drug targeting approaches, this review focusses on peptides as carriers and targeting moieties in drug-peptide covalent conjugates and summarizes the most recent literature examples where CPPs on their own or CPPs together with TTPs have been conjugated to anticancer drugs such as Doxorubicin, Methotrexate, Paclitaxel, Chlorambucil etc. A short section on CPPs used in multicomponent drug delivery systems is also included. Copyright © 2017 Elsevier B.V. All rights reserved.

Brown adipose tissue and its modulation by a mitochondria-targeted peptide in rat burn injury-induced hypermetabolism.

PubMed

Yo, Kikuo; Yu, Yong-Ming; Zhao, Gaofeng; Bonab, Ali A; Aikawa, Naoki; Tompkins, Ronald G; Fischman, Alan J

2013-02-15

Hypermetabolism is a prominent feature of burn injury, and altered mitochondria function is presumed to contribute to this state. Recently, brown adipose tissue (BAT) was found to be present not only in rodents but also in humans, and its activity is associated with resting metabolic rate. In this report, we elucidate the relationship between burn injury-induced hypermetabolism and BAT activity and the possible role of the mitochondria-targeted peptide SS31 in attenuating burn injury-induced hypermetabolism by using a rat burn injury model. We demonstrate that burn injury induces morphological changes in interscapular BAT (iBAT). Burn injury was associated with iBAT activation, and this effect was positively correlated with increased energy expenditure. BAT activation was associated with augmentation of mitochondria biogenesis, and UCP1 expression in the isolated iBAT mitochondria. In addition, the mitochondria-targeted peptide SS31 attenuated burn injury-induced hypermetabolism, which was accompanied by suppression of UCP1 expression in isolated mitochondria. Our results suggest that BAT plays an important role in burn injury-induced hypermetabolism through its morphological changes and expression of UCP1.

Fluorescence self-quenching assay for the detection of target collagen sequences using a short probe peptide.

PubMed

Nian, Linge; Hu, Yue; Fu, Caihong; Song, Chen; Wang, Jie; Xiao, Jianxi

2018-01-01

The development of novel assays to detect collagen fragments is of utmost importance for diagnostic, prognostic and therapeutic decisions in various collagen-related diseases, and one essential question is to discover probe peptides that can specifically recognize target collagen sequences. Herein we have developed the fluorescence self-quenching assay as a convenient tool to screen the capability of a series of fluorescent probe peptides of variable lengths to bind with target collagen peptides. We have revealed that the targeting ability of probe peptides is length-dependent, and have discovered a relatively short probe peptide FAM-G(POG) 8 capable to identify the target peptide. We have further demonstrated that fluorescence self-quenching assay together with this short probe peptide can be applied to specifically detect the desired collagen fragment in complex biological media. Fluorescence self-quenching assay provides a powerful new tool to discover effective peptides for the recognition of collagen biomarkers, and it may have great potential to identify probe peptides for various protein biomarkers involved in pathological conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

Conformational Ensembles Explored Dynamically from Disordered Peptides Targeting Chemokine Receptor CXCR4

PubMed Central

Vincenzi, Marian; Costantini, Susan; Scala, Stefania; Tesauro, Diego; Accardo, Antonella; Leone, Marilisa; Colonna, Giovanni; Guillon, Jean; Portella, Luigi; Trotta, Anna Maria; Ronga, Luisa; Rossi, Filomena

2015-01-01

This work reports on the design and the synthesis of two short linear peptides both containing a few amino acids with disorder propensity and an allylic ester group at the C-terminal end. Their structural properties were firstly analyzed by means of experimental techniques in solution such as CD and NMR methods that highlighted peptide flexibility. These results were further confirmed by MD simulations that demonstrated the ability of the peptides to assume conformational ensembles. They revealed a network of transient and dynamic H-bonds and interactions with water molecules. Binding assays with a well-known drug-target, i.e., the CXCR4 receptor, were also carried out in an attempt to verify their biological function and the possibility to use the assays to develop new specific targets for CXCR4. Moreover, our data indicate that these peptides represent useful tools for molecular recognition processes in which a flexible conformation is required in order to obtain an interaction with a specific target. PMID:26030674

Designer interface peptide grafts target estrogen receptor alpha dimerization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chakraborty, S.; Asare, B.K.; Biswas, P.K., E-mail: pbiswas@tougaloo.edu

The nuclear transcription factor estrogen receptor alpha (ERα), triggered by its cognate ligand estrogen, regulates a variety of cellular signaling events. ERα is expressed in 70% of breast cancers and is a widely validated target for anti-breast cancer drug discovery. Administration of anti-estrogen to block estrogen receptor activation is still a viable anti-breast cancer treatment option but anti-estrogen resistance has been a significant bottle-neck. Dimerization of estrogen receptor is required for ER activation. Blocking ERα dimerization is therefore a complementary and alternative strategy to combat anti-estrogen resistance. Dimer interface peptide “I-box” derived from ER residues 503–518 specifically blocks ER dimerization.more » Recently using a comprehensive molecular simulation we studied the interaction dynamics of ERα LBDs in a homo-dimer. Based on this study, we identified three interface recognition peptide motifs LDKITDT (ERα residues 479–485), LQQQHQRLAQ (residues 497–506), and LSHIRHMSNK (residues 511–520) and reported the suitability of using LQQQHQRLAQ (ER 497–506) as a template to design inhibitors of ERα dimerization. Stability and self-aggregation of peptide based therapeutics poses a significant bottle-neck to proceed further. In this study utilizing peptide grafted to preserve their pharmacophoric recognition motif and assessed their stability and potential to block ERα mediated activity in silico and in vitro. The Grafted peptides blocked ERα mediated cell proliferation and viability of breast cancer cells but did not alter their apoptotic fate. We believe the structural clues identified in this study can be used to identify novel peptidometics and small molecules that specifically target ER dimer interface generating a new breed of anti-cancer agents. - Highlights: • Designer peptide grafts retain core molecular recognition motif during MD simulations. • Designer peptide grafts with Poly-ALA helix form stable

Metabolic and stress-related roles of prolactin-releasing peptide.

PubMed

Onaka, Tatsushi; Takayanagi, Yuki; Leng, Gareth

2010-05-01

In the modern world, improvements in human health can be offset by unhealthy lifestyle factors, including the deleterious consequences of stress and obesity. For energy homeostasis, humoral factors and neural afferents from the gastrointestinal tract, in combination with long-term nutritional signals, communicate information to the brain to regulate energy intake and expenditure. Energy homeostasis and stress interact with each other, and stress affects both food intake and energy expenditure. Prolactin-releasing peptide, synthesized in discrete neuronal populations in the hypothalamus and brainstem, plays an important role in integrating these responses. This review describes how prolactin-releasing peptide neurons receive information concerning both internal metabolic states and environmental conditions, and play a key role in energy homeostasis and stress responses. 2010 Elsevier Ltd. All rights reserved.

A General Synthetic Approach for Designing Epitope Targeted Macrocyclic Peptide Ligands.

PubMed

Das, Samir; Nag, Arundhati; Liang, JingXin; Bunck, David N; Umeda, Aiko; Farrow, Blake; Coppock, Matthew B; Sarkes, Deborah A; Finch, Amethist S; Agnew, Heather D; Pitram, Suresh; Lai, Bert; Yu, Mary Beth; Museth, A Katrine; Deyle, Kaycie M; Lepe, Bianca; Rodriguez-Rivera, Frances P; McCarthy, Amy; Alvarez-Villalonga, Belen; Chen, Ann; Heath, John; Stratis-Cullum, Dimitra N; Heath, James R

2015-11-02

We describe a general synthetic strategy for developing high-affinity peptide binders against specific epitopes of challenging protein biomarkers. The epitope of interest is synthesized as a polypeptide, with a detection biotin tag and a strategically placed azide (or alkyne) presenting amino acid. This synthetic epitope (SynEp) is incubated with a library of complementary alkyne or azide presenting peptides. Library elements that bind the SynEp in the correct orientation undergo the Huisgen cycloaddition, and are covalently linked to the SynEp. Hit peptides are tested against the full-length protein to identify the best binder. We describe development of epitope-targeted linear or macrocycle peptide ligands against 12 different diagnostic or therapeutic analytes. The general epitope targeting capability for these low molecular weight synthetic ligands enables a range of therapeutic and diagnostic applications, similar to those of monoclonal antibodies. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dual peptide-mediated targeted delivery of bioactive siRNAs to oral cancer cells in vivo.

PubMed

Alexander-Bryant, Angela A; Zhang, Haiwen; Attaway, Christopher C; Pugh, William; Eggart, Laurence; Sansevere, Robert M; Andino, Lourdes M; Dinh, Lu; Cantini, Liliana P; Jakymiw, Andrew

2017-09-01

Despite significant advances in cancer treatment, the prognosis for oral cancer remains poor in comparison to other cancer types, including breast, skin, and prostate. As a result, more effective therapeutic modalities are needed for the treatment of oral cancer. Consequently, in the present study, we examined the feasibility of using a dual peptide carrier approach, combining an epidermal growth factor receptor (EGFR)-targeting peptide with an endosome-disruptive peptide, to mediate targeted delivery of small interfering RNAs (siRNAs) into EGFR-overexpressing oral cancer cells and induce silencing of the targeted oncogene, cancerous inhibitor of protein phosphatase 2A (CIP2A). Fluorescence microscopy, real-time PCR, Western blot analysis, and in vivo bioimaging of mice containing orthotopic xenograft tumors were used to examine the ability of the dual peptide carrier to mediate specific delivery of bioactive siRNAs into EGFR-overexpressing oral cancer cells/tissues. Co-complexation of the EGFR-targeting peptide, GE11R9, with the endosome-disruptive 599 peptide facilitated the specific uptake of siRNAs into oral cancer cells overexpressing EGFR in vitro with optimal gene silencing observed at a 60:30:1 (GE11R9:599:siRNA) molar ratio. Furthermore, when administered systemically to mice bearing xenograft oral tumors, this dual peptide complex mediated increased targeted delivery of siRNAs into tumor tissues in comparison to the 599 peptide alone and significantly enhanced CIP2A silencing. Herein we provide the first report demonstrating the clinical potential of a dual peptide strategy for siRNA-based therapeutics by synergistically mediating the effective targeting and delivery of bioactive siRNAs into EGFR-overexpressing oral cancer cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

Identification and Characterization of a Suite of Tumor Targeting Peptides for Non-Small Cell Lung Cancer

NASA Astrophysics Data System (ADS)

McGuire, Michael J.; Gray, Bethany Powell; Li, Shunzi; Cupka, Dorothy; Byers, Lauren Averett; Wu, Lei; Rezaie, Shaghayegh; Liu, Ying-Horng; Pattisapu, Naveen; Issac, James; Oyama, Tsukasa; Diao, Lixia; Heymach, John V.; Xie, Xian-Jin; Minna, John D.; Brown, Kathlynn C.

2014-03-01

Tumor targeting ligands are emerging components in cancer therapies. Widespread use of targeted therapies and molecular imaging is dependent on increasing the number of high affinity, tumor-specific ligands. Towards this goal, we biopanned three phage-displayed peptide libraries on a series of well-defined human non-small cell lung cancer (NSCLC) cell lines, isolating 11 novel peptides. The peptides show distinct binding profiles across 40 NSCLC cell lines and do not bind normal bronchial epithelial cell lines. Binding of specific peptides correlates with onco-genotypes and activation of particular pathways, such as EGFR signaling, suggesting the peptides may serve as surrogate markers. Multimerization of the peptides results in cell binding affinities between 0.0071-40 nM. The peptides home to tumors in vivo and bind to patient tumor samples. This is the first comprehensive biopanning for isolation of high affinity peptidic ligands for a single cancer type and expands the diversity of NSCLC targeting ligands.

Identification and Characterization of a Suite of Tumor Targeting Peptides for Non-Small Cell Lung Cancer

PubMed Central

McGuire, Michael J.; Gray, Bethany Powell; Li, Shunzi; Cupka, Dorothy; Byers, Lauren Averett; Wu, Lei; Rezaie, Shaghayegh; Liu, Ying-Horng; Pattisapu, Naveen; Issac, James; Oyama, Tsukasa; Diao, Lixia; Heymach, John V.; Xie, Xian-Jin; Minna, John D.; Brown, Kathlynn C.

2014-01-01

Tumor targeting ligands are emerging components in cancer therapies. Widespread use of targeted therapies and molecular imaging is dependent on increasing the number of high affinity, tumor-specific ligands. Towards this goal, we biopanned three phage-displayed peptide libraries on a series of well-defined human non-small cell lung cancer (NSCLC) cell lines, isolating 11 novel peptides. The peptides show distinct binding profiles across 40 NSCLC cell lines and do not bind normal bronchial epithelial cell lines. Binding of specific peptides correlates with onco-genotypes and activation of particular pathways, such as EGFR signaling, suggesting the peptides may serve as surrogate markers. Multimerization of the peptides results in cell binding affinities between 0.0071–40 nM. The peptides home to tumors in vivo and bind to patient tumor samples. This is the first comprehensive biopanning for isolation of high affinity peptidic ligands for a single cancer type and expands the diversity of NSCLC targeting ligands. PMID:24670678

Targeting the Atypical Chemokine Receptor ACKR3/CXCR7: Phase 1 - Phage Display Peptide Identification and Characterization.

PubMed

Vestal, R D; LaJeunesse, D R; Taylor, E W

2016-01-01

One of the greatest challenges in fighting cancer is cell targeting and biomarker selection. The Atypical Chemokine Receptor ACKR3/CXCR7 is expressed on many cancer cell types, including breast cancer and glioblastoma, and binds the endogenous ligands SDF1/CXCL12 and ITAC/CXCL11. A 20 amino acid region of the ACKR3/CXCR7 N-terminus was synthesized and targeted with the NEB PhD-7 Phage Display Peptide Library. Twenty-nine phages were isolated and heptapeptide inserts sequenced; of these, 23 sequences were unique. A 3D molecular model was created for the ACKR3/CXCR7 N-terminus by mutating the corresponding region of the crystal structure of CXCR4 with bound SDF1/CXCL12. A ClustalW alignment was performed on each peptide sequence using the entire SDF1/CXCL12 sequence as the template. The 23-peptide sequences showed similarity to three distinct regions of the SDF1/CXCL12 molecule. A 3D molecular model was made for each of the phage peptide inserts to visually identify potential areas of steric interference of peptides that simulated CXCL12 regions not in contact with the receptor's Nterminus. An ELISA analysis of the relative binding affinity between the peptides identified 9 peptides with statistically significant results. The candidate pool of 9 peptides was further reduced to 3 peptides based on their affinity for the targeted N-terminus region peptide versus no target peptide present or a scrambled negative control peptide. The results clearly show the Phage Display protocol can be used to target a synthesized region of the ACKR3/CXCR7 N-terminus. The 3 peptides chosen, P20, P3, and P9, will be the basis for further targeting studies.

Cnidarian Neurotoxic Peptides Affecting Central Nervous System Targets.

PubMed

Lazcano-Pérez, Fernando; Hernández-Guzmán, Ulises; Sánchez-Rodríguez, Judith; Arreguín-Espinosa, Roberto

2016-01-01

Natural products from animal venoms have been used widely in the discovery of novel molecules with particular biological activities that enable their use as potential drug candidates. The phylum Cnidaria (jellyfish, sea anemones, corals zoanthids, hydrozoans, etc.) is the most ancient venomous phylum on earth. Its venoms are composed of a complex mixture of peptidic compounds with neurotoxic and cytolitic properties that have shown activity on mammalian systems despite the fact that they are naturally targeted against fish and invertebrate preys, mainly crustaceans. For this reason, cnidarian venoms are an interesting and vast source of molecules with a remarkable activity on central nervous system, targeting mainly voltage-gated ion channels, ASIC channels, and TRPV1 receptors. In this brief review, we list the amino acid sequences of most cnidarian neurotoxic peptides reported to date. Additionally, we propose the inclusion of a new type of voltage-gated sea anemone sodium channel toxins based on the most recent reports.

Preparation and evaluation of the tumor-specific antigen-derived synthetic mucin 1 peptide: A potential candidate for the targeting of breast carcinoma.

PubMed

Okarvi, Subhani M; Al Jammaz, Ibrahim

2016-07-01

The goal of this study was to prepare a synthetic peptide derived from breast tumor associated antigen and to evaluate its potential as a breast cancer imaging agent. A mucin 1 derived peptide was synthesized by solid-phase peptide synthesis and examined for its radiochemical and metabolic stability. The tumor cell binding affinity of (99m)Tc-MUC1 peptide was investigated on MUC1-positive T47D and MCF7 breast cancer cell lines. In vivo biodistribution was studied in normal Balb/c mice and in vivo tumor targeting and imaging in MCF7 and T47D tumor-bearing nude mice. The synthesized MUC1-derived peptide displayed high radiochemical and metabolic stability. In vitro tumor cell-binding on T47D and MCF7 cell lines demonstrated high affinity of (99m)Tc-MUC1 peptide towards human breast cancer cells (binding affinities in nanomolar range). Pharmacokinetic studies performed on Balb/c mice are characterized by an efficient clearance from the blood and excretion predominantly through the urinary system. In vivo tumor uptake in nude mice with MCF7 tumor xenografts was 2.77±0.63% ID/g as early as 1h p.i. whereas in nude mice with T47D human ductal breast epithelial cancer cells, the accumulation in the tumor was found to be 2.65±0.54% ID/g at 1h p.i. Also tumor lesion was detectable in γ-camera imaging. The tumor uptake values were always higher than the blood and muscle uptake, with good tumor retention and good tumor-to-blood and tumor-to-muscle ratios. A low to moderate (<5% ID/g) accumulation and retention of (99m)Tc-MUC1 was found in the major organs (i.e., lungs, stomach, liver, intestines, kidneys, etc.) in both normal and tumor-bearing mice. This study suggests that (99m)Tc-MUC1 tumor-antigen peptide may be a potential candidate for the targeted imaging of MUC1-positive human tumors and warrants further investigation. Copyright © 2016 Elsevier Inc. All rights reserved.

[Co-administration of intranasally delivered insulin and proinsulin C-peptide to rats with the types 1 and 2 diabetes mellitus restores their metabolic parameters.

PubMed

Derkach, K V; Bondareva, V M; Shpakov, A O

2017-01-01

The C-peptide, the product of proinsulin proteolysis, not only is a signal molecule, but also, forming a complex with insulin, is able to modulate the signaling functions of insulin. The signaling systems sensitive to insulin in the hypothalamus and other brain areas are among the targets of insulin. We hypothesized that in systemic deficiency of insulin and C-peptide in the type 1 diabetes mellitus (DM) and in severe forms of the type 2 DM, the increase in the level of C-peptide in the CNS will improve central effects of insulin, including its influence on peripheral metabolism. To verify this, the influence of separate and co-administration of intranasal insulin (II) and C-peptide (IP) on their metabolic parameters and sensitivity to insulin in rats with acute and mild type 1 DM induced by the treatment with streptozotocin at the doses of 60 and 35 mg/kg and in rats with neonatal type 2 DM corresponding to severe long-term form of type 2 DM in human was studied. The treatment of animals with II and IP was carried out for 7 days in the daily doses of 20 and 10 μg/rat, respectively. The co-administration of II and IP leading to an increase of insulin and C-peptide levels in the brain was most effective. In rats with type 1 DM treated with the combination of II plus IP, hyperglycemia was decreased and weight loss was prevented. In rats with type 2 DM, co-administration of II and IP led to the normalization of glucose homeostasis and the increase in insulin sensitivity, as shown by glucose-tolerance and insulin-glucose tolerance tests, and to improvement of lipid metabolism, as demonstrated by the decrease in the atherogenic index. The effectiveness of monotherapy with II was lower than in the case of a combination of II+IP, while monotherapy with C-peptide had little effect on the indicators studied. Thus, the simultaneous increase of insulin and C-peptide levels in the brain in the conditions of their deficiency in diabetic pathology can be considered as one of

[Advances of tumor targeting peptides drug delivery system with pH-sensitive activities].

PubMed

Ma, Yin-yun; Li, Li; Huang, Hai-feng; Gou, San-hu; Ni, Jing-man

2016-05-01

The pH-sensitive peptides drug delivery systems, which target to acidic extracellular environment of tumor tissue, have many advantages in drug delivery. They exhibit a high specificity to tumor and low cytotoxicity, which significantly increase the efficacy of traditional anti-cancer drugs. In recent years the systems have received a great attention. The pH-sensitive peptides drug delivery systems can be divided into five types according to the difference in pH-responsive mechanism,type of peptides and carrier materials. This paper summarizes the recent progresses in the field with a focus on the five types of pH-sensitive peptides in drug delivery systems. This may provide a guideline to design and application of tumor targeting drugs.

Brown adipose tissue and its modulation by a mitochondria-targeted peptide in rat burn injury-induced hypermetabolism

PubMed Central

Yo, Kikuo; Yu, Yong-Ming; Zhao, Gaofeng; Bonab, Ali A.; Aikawa, Naoki; Tompkins, Ronald G.

2013-01-01

Hypermetabolism is a prominent feature of burn injury, and altered mitochondria function is presumed to contribute to this state. Recently, brown adipose tissue (BAT) was found to be present not only in rodents but also in humans, and its activity is associated with resting metabolic rate. In this report, we elucidate the relationship between burn injury-induced hypermetabolism and BAT activity and the possible role of the mitochondria-targeted peptide SS31 in attenuating burn injury-induced hypermetabolism by using a rat burn injury model. We demonstrate that burn injury induces morphological changes in interscapular BAT (iBAT). Burn injury was associated with iBAT activation, and this effect was positively correlated with increased energy expenditure. BAT activation was associated with augmentation of mitochondria biogenesis, and UCP1 expression in the isolated iBAT mitochondria. In addition, the mitochondria-targeted peptide SS31 attenuated burn injury-induced hypermetabolism, which was accompanied by suppression of UCP1 expression in isolated mitochondria. Our results suggest that BAT plays an important role in burn injury-induced hypermetabolism through its morphological changes and expression of UCP1. PMID:23169784

Atrial natriuretic peptide: a magic bullet for cancer therapy targeting Wnt signaling and cellular pH regulators.

PubMed

Serafino, A; Pierimarchi, P

2014-01-01

Atrial natriuretic peptide (ANP) is a cardiac hormone playing a crucial role in cardiovascular homeostasis mainly through blood volume and pressure regulation. In the last years, the new property ascribed to ANP of inhibiting tumor growth both in vitro and in vivo has made this peptide an attractive candidate for anticancer therapy. The molecular mechanism underlying the anti-proliferative effect of ANP has been mainly related to its interaction with the specific receptors NPRs, through which this natriuretic hormone inhibits some metabolic targets critical for cancer development, including the Ras-MEK1⁄2-ERK1⁄2 kinase cascade, functioning as a multikinase inhibitor. In this review we summarize the current knowledge on this topic, focusing on our recent data demonstrating that the antitumor activity of this natriuretic hormone is also mediated by a concomitant effect on the Wnt/β-catenin pathway and on the pH regulation ability of cancer cells, through a Frizzled-related mechanism. This peculiarity of simultaneously targeting two processes crucial for neoplastic transformation and solid tumor survival reinforces the utility of ANP for the development of both preventive and therapeutic strategies.

The Neurofilament-Derived Peptide NFL-TBS.40-63 Targets Neural Stem Cells and Affects Their Properties.

PubMed

Lépinoux-Chambaud, Claire; Barreau, Kristell; Eyer, Joël

2016-07-01

Targeting neural stem cells (NSCs) in the adult brain represents a promising approach for developing new regenerative strategies, because these cells can proliferate, self-renew, and differentiate into new neurons, astrocytes, and oligodendrocytes. Previous work showed that the NFL-TBS.40-63 peptide, corresponding to the sequence of a tubulin-binding site on neurofilaments, can target glioblastoma cells, where it disrupts their microtubules and inhibits their proliferation. We show that this peptide targets NSCs in vitro and in vivo when injected into the cerebrospinal fluid. Although neurosphere formation was not altered by the peptide, the NSC self-renewal capacity and proliferation were reduced and were associated with increased adhesion and differentiation. These results indicate that the NFL-TBS.40-63 peptide represents a new molecular tool to target NSCs to develop new strategies for regenerative medicine and the treatment of brain tumors. In the present study, the NFL-TBS.40-63 peptide targeted neural stem cells in vitro when isolated from the subventricular zone and in vivo when injected into the cerebrospinal fluid present in the lateral ventricle. The in vitro formation of neurospheres was not altered by the peptide; however, at a high concentration of the peptide, the neural stem cell (NSC) self-renewal capacity and proliferation were reduced and associated with increased adhesion and differentiation. These results indicate that the NFL-TBS.40-63 peptide represents a new molecular tool to target NSCs to develop new strategies for regenerative medicine and the treatment of brain tumors. ©AlphaMed Press.

Discovery of peptide drug carrier candidates for targeted multi-drug delivery into prostate cancer cells.

PubMed

Bashari, O; Redko, B; Cohen, A; Luboshits, G; Gellerman, G; Firer, M A

2017-11-01

Metastatic castration-resistant prostate cancer (mCRPC) remains essentially incurable. Targeted Drug Delivery (TDD) systems may overcome the limitations of current mCRPC therapies. We describe the use of strict criteria to isolate novel prostate cancer cell targeting peptides that specifically deliver drugs into target cells. Phage from a libraries displaying 7mer peptides were exposed to PC-3 cells and only internalized phage were recovered. The ability of these phage to internalize into other prostate cancer cells (LNCaP, DU-145) was validated. The displayed peptides of selected phage clones were synthesized and their specificity for target cells was validated in vitro and in vivo. One peptide (P12) which specifically targeted PC-3 tumors in vivo was incorporated into mono-drug (Chlorambucil, Combretastatin or Camptothecin) and dual-drug (Chlorambucil/Combretastatin or Chlorambucil/Camptothecin) PDCs and the cytotoxic efficacy of these conjugates for target cells was tested. Conjugation of P12 into dual-drug PDCs allowed discovery of new drug combinations with synergistic effects. The use of strict selection criteria can lead to discovery of novel peptides for use as drug carriers for TDD. PDCs represent an effective alternative to current modes of free drug chemotherapy for prostate cancer. Copyright © 2017. Published by Elsevier B.V.

Opposing intermolecular tuning of Ca2+ affinity for Calmodulin by its target peptides

NASA Astrophysics Data System (ADS)

Cheung, Margaret

We investigated the impact of bound calmodulin (CaM)-target compound structure on the affinity of calcium (Ca2+) by integrating coarse-grained models and all-atomistic simulations with non-equilibrium physics. We focused on binding between CaM and two specific targets, Ca2+/CaM-dependent protein kinase II (CaMKII) and neurogranin (Ng), as they both regulate CaM-dependent Ca2+ signaling pathways in neurons. It was shown experimentally that Ca2+/CaM binds to the CaMKII peptide with higher affinity than the Ng peptide. The binding of CaMKII peptide to CaM in return increases the Ca2+ affinity for CaM. However, this reciprocal relation was not observed in the Ng peptide, which binds to Ca2+-free CaM or Ca2+/CaM with similar binding affinity. Unlike CaM-CaMKII peptide that allowed structure determination by crystallography, the structural description of CaM-Ng peptide is unknown due to low binding affinity, therefore, we computationally generated an ensemble of CaM-Ng peptide structures by matching the changes in the chemical shifts of CaM upon Ng peptide binding from nuclear magnetic resonance experiments. We computed the changes in Ca2+ affinity for CaM with and without binding targets in atomistic models using Jarzynski's equality. We discovered the molecular underpinnings of lowered affinity of Ca2+ for CaM in the presence of Ng by showing that the N-terminal acidic region of Ng peptide pries open the β-sheet structure between the Ca2+ binding loops particularly at C-domain of CaM, enabling Ca2+release. In contrast, CaMKII increases Ca2+ affinity for the C-domain of CaM by stabilizing the two Ca2+ binding loops.

Phthalocyanine-Peptide Conjugates for Epidermal Growth Factor Receptor Targeting1

PubMed Central

Ongarora, Benson G.; Fontenot, Krystal R.; Hu, Xiaoke; Sehgal, Inder; Satyanarayana-Jois, Seetharama D.; Vicente, M. Graça H.

2012-01-01

Four phthalocyanine (Pc)-peptide conjugates designed to target the epidermal growth factor receptor (EGFR) were synthesized and evaluated in vitro using four cell lines: human carcinoma A431 and HEp2, human colorectal HT-29, and kidney Vero (negative control) cells. Two peptide ligands for EGFR were investigated: EGFR-L1 and -L2, bearing 6 and 13 amino acid residues, respectively. The peptides and Pc-conjugates were shown to bind to EGFR using both theoretical (Autodock) and experimental (SPR) investigations. The Pc-EGFR-L1 conjugates 5a and 5b efficiently targeted EGFR and were internalized, in part due to their cationic charge, whereas the uncharged Pc-EGFR-L2 conjugates 4b and 6a poorly targeted EGFR maybe due to their low aqueous solubility. All conjugates were non-toxic (IC50 > 100 µM) to HT-29 cells, both in the dark and upon light activation (1 J/cm2). Intravenous (iv) administration of conjugate 5b into nude mice bearing A431 and HT-29 human tumor xenografts resulted in a near-IR fluorescence signal at ca. 700 nm, 24 h after administration. Our studies show that Pc-EGFR-L1 conjugates are promising near-IR fluorescent contrast agents for CRC, and potentially other EGFR over-expressing cancers. PMID:22468711

Enhanced EGFR Targeting Activity of Plasmonic Nanostructures with Engineered GE11 Peptide.

PubMed

Biscaglia, Francesca; Rajendran, Senthilkumar; Conflitti, Paolo; Benna, Clara; Sommaggio, Roberta; Litti, Lucio; Mocellin, Simone; Bocchinfuso, Gianfranco; Rosato, Antonio; Palleschi, Antonio; Nitti, Donato; Gobbo, Marina; Meneghetti, Moreno

2017-12-01

Plasmonic nanostructures show important properties for biotechnological applications, but they have to be guided on the target for exploiting their potentialities. Antibodies are the natural molecules for targeting. However, their possible adverse immunogenic activity and their cost have suggested finding other valid substitutes. Small molecules like peptides can be an alternative source of targeting agents, even if, as single molecules, their binding affinity is usually not very good. GE11 is a small dodecapeptide with specific binding to the epidermal growth factor receptor (EGFR) and low immunogenicity. The present work shows that thousands of polyethylene glycol (PEG) chains modified with lysines and functionalized with GE11 on clusters of naked gold nanoparticles, obtained by laser ablation in water, achieves a better targeting activity than that recorded with nanoparticles decorated with the specific anti-EGFR antibody Cetuximab (C225). The insertion of the cationic spacer between the polymeric part of the ligand and the targeting peptide allows for a proper presentation of GE11 on the surface of the nanosystems. Surface enhanced resonance Raman scattering signals of the plasmonic gold nanoparticles are used for quantifying the targeting activity. Molecular dynamic calculations suggest that subtle differences in the exposition of the peptide on the PEG sea are important for the targeting activity. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthetic Peptide Drugs for Targeting Skin Cancer: Malignant Melanoma and Melanotic Lesions.

PubMed

Eberle, Alex N; Rout, Bhimsen; Qi, Mei Bigliardi; Bigliardi, Paul L

2017-01-01

Peptides play decisive roles in the skin, ranging from host defense responses to various forms of neuroendocrine regulation of cell and organelle function. Synthetic peptides conjugated to radionuclides or photosensitizers may serve to identify and treat skin tumors and their metastatic forms in other organs of the body. In the introductory part of this review, the role and interplay of the different peptides in the skin are briefly summarized, including their potential application for the management of frequently occurring skin cancers. Special emphasis is given to different targeting options for the treatment of melanoma and melanotic lesions. Radionuclide Targeting: α-Melanocyte-stimulating hormone (α-MSH) is the most prominent peptide for targeting of melanoma tumors via the G protein-coupled melanocortin-1 receptor that is (over-)expressed by melanoma cells and melanocytes. More than 100 different linear and cyclic analogs of α-MSH containing chelators for 111In, 67/68Ga, 64Cu, 90Y, 212Pb, 99mTc, 188Re were synthesized and examined with experimental animals and in a few clinical studies. Linear Ac-Nle-Asp-His-D-Phe-Arg-Trp-Gly-Lys-NH2 (NAP-amide) and Re-cyclized Cys- Cys-Glu-His-D-Phe-Arg-Trp-Cys-Arg-Pro-Val-NH2 (Re[Arg11]CCMSH) containing different chelators at the N- or C-terminus served as lead compounds for peptide drugs with further optimized characteristics. Alternatively, melanoma may be targeted with radiopeptides that bind to melanin granules occurring extracellularly in these tumors. Photosensitizer targeting: A more recent approach is the application of photosensitizers attached to the MSH molecule for targeted photodynamic therapy using LED or coherent laser light that specifically activates the photosensitizer. Experimental studies have demonstrated the feasibility of this approach as a more gentle and convenient alternative compared to radionuclides. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

99mTc-D(LPR): A novel retro-inverso peptide for VEGF receptor-1 targeted tumor imaging.

PubMed

Rezazadeh, Farzaneh; Sadeghzadeh, Nourollah; Abedi, Seyed Mohammad; Abediankenari, Saeid

2018-05-31

The aim of this study was to evaluate the ability of D (LPR), a novel retro-inverso peptidomimetic derivative for imaging colon cancer. Two different D (LPR) analogs were designed and compared based on conjugation of HYNIC at peptide's C or N terminal and then labeled with technetium-99m using tricine/EDDA as an exchange coligands. The radiolabeled conjugates were assessed for in vitro stability in saline and serum. The VEGFR-1 and NRP-1 receptors affinity, in vitro internalization and also dissociation Constance was evaluated. SPCET imaging and biodistribution studies were performed in nude mice bearing HT-29 xenograft tumors. Both peptides labeled with technetium-99m in high radiochemical yield (˃97%). Peptide stability studies indicated a high metabolic stability of the radiopeptides in solution and serum. In vitro blocking studies demonstrated specific binding and internalization of [ 99m Tc]Tc-HYNIC-peptides in cultured HUVEC cells. The K d value for 99m Tc-peptide 1 and 99m Tc-peptide 2 were found to be 56.8 ± 12.9 nM and 71.6 ± 17.9 nM respectively. The tumor to muscle ratio was significant at 0.5 and 1 h after injection (4.5 and 4 for 99m Tc-peptide 1 and 4.9 and 4.4 for 99m Tc-peptide 2 at 0.5 and 1 h p.i. respectively). SPECT imaging studies revealed that both radioconjugates had prominent activity accumulation in VEGFR-1 and NRP-1 expressing HT-29 tumors. This study is the first instance of using a radiolabeled retro-inverso peptide for tumor imaging which is a promising tool to improve the performance of fragile peptide probes in vivo as imaging agents and warrant further investigations in other peptide-target systems. Copyright © 2018 Elsevier Inc. All rights reserved.

Liposome-based glioma targeted drug delivery enabled by stable peptide ligands.

PubMed

Wei, Xiaoli; Gao, Jie; Zhan, Changyou; Xie, Cao; Chai, Zhilan; Ran, Danni; Ying, Man; Zheng, Ping; Lu, Weiyue

2015-11-28

The treatment of glioma is one of the most challenging tasks in clinic. As an intracranial tumor, glioma exhibits many distinctive characteristics from other tumors. In particular, various barriers including enzymatic barriers in the blood and brain capillary endothelial cells, blood-brain barrier (BBB) and blood-brain tumor barrier (BBTB) rigorously prevent drug and drug delivery systems from reaching the tumor site. To tackle this dilemma, we developed a liposomal formulation to circumvent multiple-barriers by modifying the liposome surface with proteolytically stable peptides, (D)CDX and c(RGDyK). (D)CDX is a D-peptide ligand of nicotine acetylcholine receptors (nAChRs) on the BBB, and c(RGDyK) is a ligand of integrin highly expressed on the BBTB and glioma cells. Lysosomal compartments of brain capillary endothelial cells are implicated in the transcytosis of those liposomes. However, both peptide ligands displayed exceptional stability in lysosomal homogenate, ensuring that intact ligands could exert subsequent exocytosis from brain capillary endothelial cells and glioma targeting. In the cellular uptake studies, dually labeled liposomes could target both brain capillary endothelial cells and tumor cells, effectively traversing the BBB and BBTB monolayers, overcoming enzymatic barrier and targeting three-dimensional tumor spheroids. Its targeting ability to intracranial glioma was further verified in vivo by ex vivo imaging and histological studies. As a result, doxorubicin liposomes modified with both (D)CDX and c(RGDyK) presented better anti-glioma effect with prolonged median survival of nude mice bearing glioma than did unmodified liposomes and liposomes modified with individual peptide ligand. In conclusion, the liposome suggested in the present study could effectively overcome multi-barriers and accomplish glioma targeted drug delivery, validating its potential value in improving the therapeutic efficacy of doxorubicin for glioma. Copyright © 2015

ATP Synthase: A Molecular Therapeutic Drug Target for Antimicrobial and Antitumor Peptides

PubMed Central

Ahmad, Zulfiqar; Okafor, Florence; Azim, Sofiya; Laughlin, Thomas F.

2015-01-01

In this review we discuss the role of ATP synthase as a molecular drug target for natural and synthetic antimi-crobial/antitumor peptides. We start with an introduction of the universal nature of the ATP synthase enzyme and its role as a biological nanomotor. Significant structural features required for catalytic activity and motor functions of ATP synthase are described. Relevant details regarding the presence of ATP synthase on the surface of several animal cell types, where it is associated with multiple cellular processes making it a potential drug target with respect to antimicrobial peptides and other inhibitors such as dietary polyphenols, is also reviewed. ATP synthase is known to have about twelve discrete inhibitor binding sites including peptides and other inhibitors located at the interface of α/β subunits on the F1 sector of the enzyme. Molecular interaction of peptides at the β DEELSEED site on ATP synthase is discussed with specific examples. An inhibitory effect of other natural/synthetic inhibitors on ATP is highlighted to explore the therapeutic roles played by peptides and other inhibitors. Lastly, the effect of peptides on the inhibition of the Escherichia coli model system through their action on ATP synthase is presented. PMID:23432591

Towards Discovery and Targeted Peptide Biomarker Detection Using nanoESI-TIMS-TOF MS

NASA Astrophysics Data System (ADS)

Garabedian, Alyssa; Benigni, Paolo; Ramirez, Cesar E.; Baker, Erin S.; Liu, Tao; Smith, Richard D.; Fernandez-Lima, Francisco

2018-05-01

In the present work, the potential of trapped ion mobility spectrometry coupled to TOF mass spectrometry (TIMS-TOF MS) for discovery and targeted monitoring of peptide biomarkers from human-in-mouse xenograft tumor tissue was evaluated. In particular, a TIMS-MS workflow was developed for the detection and quantification of peptide biomarkers using internal heavy analogs, taking advantage of the high mobility resolution (R = 150-250) prior to mass analysis. Five peptide biomarkers were separated, identified, and quantified using offline nanoESI-TIMS-CID-TOF MS; the results were in good agreement with measurements using a traditional LC-ESI-MS/MS proteomics workflow. The TIMS-TOF MS analysis permitted peptide biomarker detection based on accurate mobility, mass measurements, and high sequence coverage for concentrations in the 10-200 nM range, while simultaneously achieving discovery measurements of not initially targeted peptides as markers from the same proteins and, eventually, other proteins. [Figure not available: see fulltext.

Using Data Independent Acquisition (DIA) to Model High-responding Peptides for Targeted Proteomics Experiments*

PubMed Central

Searle, Brian C.; Egertson, Jarrett D.; Bollinger, James G.; Stergachis, Andrew B.; MacCoss, Michael J.

2015-01-01

Targeted mass spectrometry is an essential tool for detecting quantitative changes in low abundant proteins throughout the proteome. Although selected reaction monitoring (SRM) is the preferred method for quantifying peptides in complex samples, the process of designing SRM assays is laborious. Peptides have widely varying signal responses dictated by sequence-specific physiochemical properties; one major challenge is in selecting representative peptides to target as a proxy for protein abundance. Here we present PREGO, a software tool that predicts high-responding peptides for SRM experiments. PREGO predicts peptide responses with an artificial neural network trained using 11 minimally redundant, maximally relevant properties. Crucial to its success, PREGO is trained using fragment ion intensities of equimolar synthetic peptides extracted from data independent acquisition experiments. Because of similarities in instrumentation and the nature of data collection, relative peptide responses from data independent acquisition experiments are a suitable substitute for SRM experiments because they both make quantitative measurements from integrated fragment ion chromatograms. Using an SRM experiment containing 12,973 peptides from 724 synthetic proteins, PREGO exhibits a 40–85% improvement over previously published approaches at selecting high-responding peptides. These results also represent a dramatic improvement over the rules-based peptide selection approaches commonly used in the literature. PMID:26100116

Mitochondrial VDAC1-based peptides: Attacking oncogenic properties in glioblastoma

PubMed Central

Shteinfer-Kuzmine, Anna; Arif, Tasleem; Krelin, Yakov; Tripathi, Shambhoo Sharan; Paul, Avijit; Shoshan-Barmatz, Varda

2017-01-01

Glioblastoma multiforme (GBM), a primary brain malignancy characterized by high morbidity, invasiveness, proliferation, relapse and mortality, is resistant to chemo- and radiotherapies and lacks effective treatment. GBM tumors undergo metabolic reprograming and develop anti-apoptotic defenses. We targeted GBM with a peptide derived from the mitochondrial protein voltage-dependent anion channel 1 (VDAC1), a key component of cell energy, metabolism and apoptosis regulation. VDAC1-based cell-penetrating peptides perturbed cell energy and metabolic homeostasis and induced apoptosis in several GBM and GBM-derived stem cell lines. We found that the peptides simultaneously attacked several oncogenic properties of human U-87MG cells introduced into sub-cutaneous xenograft mouse model, inhibiting tumor growth, invasion, and cellular metabolism, stemness and inducing apoptosis. Peptide-treated tumors showed decreased expression of all tested metabolism-related enzymes and transporters, and elevated levels of apoptotic proteins, such as p53, cytochrome c and caspases. Retro-Tf-D-LP4, containing the human transferrin receptor (TfR)-recognition sequence, crossed the blood-brain barrier (BBB) via the TfR that is highly expressed in the BBB to strongly inhibit tumor growth in an intracranial xenograft mouse model. In summary, the VDAC1-based peptides tested here offer a potentially affordable and innovative new conceptual therapeutic paradigm that might overcome GBM stemness and invasiveness and reduce relapse rates. PMID:28412744

Cancer metabolism: strategic diversion from targeting cancer drivers to targeting cancer suppliers.

PubMed

Kim, Soo-Youl

2015-03-01

Drug development groups are close to discovering another pot of gold-a therapeutic target-similar to the success of imatinib (Gleevec) in the field of cancer biology. Modern molecular biology has improved cancer therapy through the identification of more pharmaceutically viable targets, and yet major problems and risks associated with late-phase cancer therapy remain. Presently, a growing number of reports have initiated a discussion about the benefits of metabolic regulation in cancers. The Warburg effect, a great discovery approximately 70 years ago, addresses the "universality" of cancer characteristics. For instance, most cancer cells prefer aerobic glycolysis instead of mitochondrial respiration. Recently, cancer metabolism has been explained not only by metabolites but also through modern molecular and chemical biological techniques. Scientists are seeking context-dependent universality among cancer types according to metabolic and enzymatic pathway signatures. This review presents current cancer metabolism studies and discusses future directions in cancer therapy targeting bio-energetics, bio-anabolism, and autophagy, emphasizing the important contribution of cancer metabolism in cancer therapy.

Manual method of visually identifying candidate signals for a targeted peptide.

PubMed

Filimonov, Aleksey; Kopylov, Arthur; Lisitsa, Andrey; Archakov, Alexander

2018-04-15

The purpose of this study is to improve peptide signal identification in groups of extracted ion chromatograms (XICs) obtained with the liquid chromatography-selected reaction monitoring (LC-SRM) technique and a triple quadrupole mass spectrometer (QqQ) operating in one of the supported multiple reaction monitoring (MRM) modes. The imperfection of quadrupole mass analyzers causes ion interference, which impedes the identification of peptide signals as chromatographic peak groups in relevant retention time intervals. To investigate this problem in depth, the QqQ conversion of the eluate into XIC groups was considered as the consecutive transformations of the particles' abundances as the corresponding functions of retention time. In this study, the hypothesis that, during this conversion, the same chromatographic profile should be preserved as an implicit sign in each chromatographic peak of the signal was confirmed for peptides. To examine chromatographic profiles, continuous transformations of XIC groups were derived and implemented in srm2prot Express software (s2pe, http://msr.ibmc.msk.ru/s2pe). Because of ion interference, several peptide-like signals may appear in one XIC group. Therefore, these signals must be considered candidates for a targeted peptide's signal and should be resolved after identification. The theoretical investigation of intensity functions as XICs that are not distorted by noise produced three rules for Identifying Candidate Signals for a targeted Peptide (ICSP, http://msr.ibmc.msk.ru/ICSP) that constitute the proposed manual visual method. We theoretically and experimentally compared this method with the conventional semiempirical intuitive technique and found that the former significantly streamlines peptide signal identification and avoids typical errors. Copyright © 2018 Elsevier B.V. All rights reserved.

Targeting nanoparticles to M cells with non-peptidic ligands for oral vaccination.

PubMed

Fievez, Virginie; Plapied, Laurence; des Rieux, Anne; Pourcelle, Vincent; Freichels, Hélène; Wascotte, Valentine; Vanderhaeghen, Marie-Lyse; Jerôme, Christine; Vanderplasschen, Alain; Marchand-Brynaert, Jacqueline; Schneider, Yves-Jacques; Préat, Véronique

2009-09-01

The presence of RGD on nanoparticles allows the targeting of beta1 integrins at the apical surface of human M cells and the enhancement of an immune response after oral immunization. To check the hypothesis that non-peptidic ligands targeting intestinal M cells or APCs would be more efficient for oral immunization than RGD, novel non-peptidic and peptidic analogs (RGD peptidomimitic (RGDp), LDV derivative (LDVd) and LDV peptidomimetic (LDVp)) as well as mannose were grafted on the PEG chain of PCL-PEG and incorporated in PLGA-based nanoparticles. RGD and RGDp significantly increased the transport of nanoparticles across an in vitro model of human M cells as compared to enterocytes. RGD, LDVp, LDVd and mannose enhanced nanoparticle uptake by macrophages in vitro. The intraduodenal immunization with RGDp-, LDVd- or mannose-labeled nanoparticles elicited a higher production of IgG antibodies than the intramuscular injection of free ovalbumin or intraduodenal administration of either non-targeted or RGD-nanoparticles. Targeted formulations were also able to induce a cellular immune response. In conclusion, the in vitro transport of nanoparticles, uptake by macrophages and the immune response were positively influenced by the presence of ligands at the surface of nanoparticles. These targeted-nanoparticles could thus represent a promising delivery system for oral immunization.

Conformationally constrained peptides target the allosteric kinase dimer interface and inhibit EGFR activation.

PubMed

Fulton, Melody D; Hanold, Laura E; Ruan, Zheng; Patel, Sneha; Beedle, Aaron M; Kannan, Natarajan; Kennedy, Eileen J

2018-03-15

Although EGFR is a highly sought-after drug target, inhibitor resistance remains a challenge. As an alternative strategy for kinase inhibition, we sought to explore whether allosteric activation mechanisms could effectively be disrupted. The kinase domain of EGFR forms an atypical asymmetric dimer via head-to-tail interactions and serves as a requisite for kinase activation. The kinase dimer interface is primarily formed by the H-helix derived from one kinase monomer and the small lobe of the second monomer. We hypothesized that a peptide designed to resemble the binding surface of the H-helix may serve as an effective disruptor of EGFR dimerization and activation. A library of constrained peptides was designed to mimic the H-helix of the kinase domain and interface side chains were optimized using molecular modeling. Peptides were constrained using peptide "stapling" to structurally reinforce an alpha-helical conformation. Peptide stapling was demonstrated to notably enhance cell permeation of an H-helix derived peptide termed EHBI2. Using cell-based assays, EHBI2 was further shown to significantly reduce EGFR activity as measured by EGFR phosphorylation and phosphorylation of the downstream signaling substrate Akt. To our knowledge, this is the first H-helix-based compound targeting the asymmetric interface of the kinase domain that can successfully inhibit EGFR activation and signaling. This study presents a novel, alternative targeting site for allosteric inhibition of EGFR. Copyright © 2017 Elsevier Ltd. All rights reserved.

Kefir Peptides Prevent Hyperlipidemia and Obesity in High-Fat-Diet-Induced Obese Rats via Lipid Metabolism Modulation.

PubMed

Tung, Yu-Tang; Chen, Hsiao-Ling; Wu, Hsin-Shan; Ho, Mei-Hsuan; Chong, Kowit-Yu; Chen, Chuan-Mu

2018-02-01

Obesity has reached epidemic proportions worldwide. Obesity is a complex metabolic disorder that is linked to numerous serious health complications with high morbidity. The present study evaluated the effects of kefir peptides on high fat diet (HFD)-induced obesity in rats. Kefir peptides markedly improved obesity, including body weight gain, inflammatory reactions and the formation of adipose tissue fat deposits around the epididymis and kidney, and adipocyte size. Treating high fat diet (HFD)-induced obese rats with kefir peptides significantly reduced the fatty acid synthase protein and increased the p-acetyl-CoA carboxylase protein to block lipogenesis in the livers. Kefir peptides also increased fatty acid oxidation by increasing the protein expressions of phosphorylated AMP-activated protein kinase, peroxisome proliferator-activated receptor-α, and hepatic carnitine palmitoyltransferase-1 in the livers. In addition, administration of kefir peptides significantly decreased the inflammatory response (TNF-α, IL-1β, and TGF-β) to modulate oxidative damage. These results demonstrate that kefir peptides treatment improves obesity via inhibition of lipogenesis, modulation of oxidative damage, and stimulation of lipid oxidation. Therefore, kefir peptides may act as an anti-obesity agent to prevent body fat accumulation and obesity-related metabolic diseases. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Improved tumor-targeting MRI contrast agents: Gd(DOTA) conjugates of a cycloalkane-based RGD peptide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Ji-Ae, E-mail: jpark@kirams.re.kr; Lee, Yong Jin; Ko, In Ok

2014-12-12

Highlights: • Development of improved tumor-targeting MRI contrast agents. • To increase the targeting ability of RGD, we developed cycloalkane-based RGD peptides. • Gd(DOTA) conjugates of cycloalkane-based RGD peptide show improved tumor signal enhancement in vivo MR images. - Abstract: Two new MRI contrast agents, Gd-DOTA-c(RGD-ACP-K) (1) and Gd-DOTA-c(RGD-ACH-K) (2), which were designed by incorporating aminocyclopentane (ACP)- or aminocyclohexane (ACH)-carboxylic acid into Gd-DOTA (gadolinium-tetraazacyclo dodecanetetraacetic acid) and cyclic RGDK peptides, were synthesized and evaluated for tumor-targeting ability in vitro and in vivo. Binding affinity studies showed that both 1 and 2 exhibited higher affinity for integrin receptors than cyclic RGDyKmore » peptides, which were used as a reference. These complexes showed high relaxivity and good stability in human serum and have the potential to improve target-specific signal enhancement in vivo MR images.« less

Targeted transport of nanocarriers into brain for theranosis with rabies virus glycoprotein-derived peptide.

PubMed

Fu, Chen; Xiang, Yonggang; Li, Xiaorong; Fu, Ailing

2018-06-01

For successful theranosis of brain diseases, limited access of therapeutic molecules across blood-brain barrier (BBB) needs be overcome in brain delivery. Currently, peptide derivatives of rabies virus glycoprotein (RVG) have been exploited as delivery ligands to transport nanocarriers across BBB and specifically into the brain. The targeting peptides usually conjugate to the nanocarrier surface, and the cargoes, including siRNA, miRNA, DNA, proteins and small molecular chemicals, are complexed or encapsulated in the nanocarriers. The peptide ligand of the RVG-modified nanocarriers introduces the conjugated targeted-delivery into the brain, and the cargoes are involved in disease theranosis. The peptide-modified nanocarriers have been applied to diagnose and treat various brain diseases, such as glioma, Alzheimer's disease, ischemic injury, protein misfolding diseases etc. Since the targeting delivery system has displayed good biocompatibility and desirable therapeutic effect, it will raise a potential application in treating brain diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

Fetoprotein Derived Short Peptide Coated Nanostructured Amphiphilic Surfaces for Targeting Mouse Breast Cancer Cells

NASA Astrophysics Data System (ADS)

Brown, Alexandra M.; Miranda-Alarćon, Yoliem S.; Knoll, Grant A.; Santora, Anthony M.; Banerjee, Ipsita A.

In this work, self-assembled tumor targeting nanostructured surfaces were developed from a newly designed amphiphile by conjugating boc protected isoleucine with 2,2‧ ethylenedioxy bis ethylamine (IED). To target mouse mammary tumor cells, a short peptide sequence derived from the human alpha-fetoprotein (AFP), LSEDKLLACGEG was attached to the self-assembled nanostructures. Tumor targeting and cell proliferation were examined in the presence of nanoscale assemblies. To further obliterate mouse breast tumor cells, the chemotherapeutic drug tamoxifen was then entrapped into the nanoassemblies. Our studies indicated that the targeting systems were able to efficiently encapsulate and release tamoxifen. Cell proliferation studies showed that IED-AFP peptide loaded with tamoxifen decreased the proliferation of breast cancer cells while in the presence of the IED-AFP peptide nanoassemblies alone, the growth was relatively slower. In the presence of human dermal fibroblasts however cell proliferation continued similar to controls. Furthermore, the nanoscale assemblies were found to induce apoptosis in mouse breast cancer cells. To examine live binding interactions, SPR analysis revealed that tamoxifen encapsulated IED-AFP peptide nanoassemblies bound to the breast cancer cells more efficiently compared to unencapsulated assemblies. Thus, we have developed nanoscale assemblies that can specifically bind to and target tumor cells, with increased toxicity in the presence of a chemotherapeutic drug.

Peptide-based pharmacomodulation of a cancer-targeted optical imaging and photodynamic therapy agent

PubMed Central

Stefflova, Klara; Li, Hui; Chen, Juan; Zheng, Gang

2008-01-01

We designed and synthesized a folate receptor-targeted, water soluble, and pharmacomodulated photodynamic therapy (PDT) agent that selectively detects and destroys the targeted cancer cells while sparing normal tissue. This was achieved by minimizing the normal organ uptake (e.g., liver and spleen) and by discriminating between tumors with different levels of folate receptor (FR) expression. This construct (Pyro-peptide-Folate, PPF) is comprised of three components: 1) Pyropheophorbide a (Pyro) as an imaging and therapeutic agent, 2) peptide sequence as a stable linker and modulator improving the delivery efficiency, and 3) Folate as a homing molecule targeting FR-expressing cancer cells. We observed an enhanced accumulation of PPF in KB cancer cells (FR+) compared to HT 1080 cancer cells (FR-), resulting in a more effective post-PDT killing of KB cells over HT 1080 or normal CHO cells. The accumulation of PPF in KB cells can be up to 70% inhibited by an excess of free folic acid. The effect of Folate on preferential accumulation of PPF in KB tumors (KB vs. HT 1080 tumors 2.5:1) was also confirmed in vivo. In contrast to that, no significant difference between the KB and HT 1080 tumor was observed in case of the untargeted probe (Pyro-peptide, PP), eliminating the potential influence of Pyro’s own nonspecific affinity to cancer cells. More importantly, we found that incorporating a short peptide sequence considerably improved the delivery efficiency of the probe – a process we attributed to a possible peptide-based pharmacomodulation – as was demonstrated by a 50-fold reduction in PPF accumulation in liver and spleen when compared to a peptide-lacking probe (Pyro-K-Folate, PKF). This approach could potentially be generalized to improve the delivery efficiency of other targeted molecular imaging and photodynamic therapy agents. PMID:17298029

Cullin3 - BTB Interface: A Novel Target for Stapled Peptides

PubMed Central

Palmieri, Maddalena; Balasco, Nicole; Esposito, Luciana; Russo, Luigi; Mazzà, Daniela; Di Marcotullio, Lucia; Di Gaetano, Sonia; Malgieri, Gaetano; Vitagliano, Luigi; Pedone, Emilia; Zaccaro, Laura

2015-01-01

Cullin3 (Cul3), a key factor of protein ubiquitination, is able to interact with dozens of different proteins containing a BTB (Bric-a-brac, Tramtrack and Broad Complex) domain. We here targeted the Cul3–BTB interface by using the intriguing approach of stabilizing the α-helical conformation of Cul3-based peptides through the “stapling” with a hydrocarbon cross-linker. In particular, by combining theoretical and experimental techniques, we designed and characterized stapled Cul3-based peptides embedding the helix 2 of the protein (residues 49–68). Intriguingly, CD and NMR experiments demonstrate that these stapled peptides were able to adopt the helical structure that the fragment assumes in the parent protein. We also show that some of these peptides were able to bind to the BTB of the tetrameric KCTD11, a substrate adaptor involved in HDAC1 degradation, with high affinity (~ 300–600 nM). Cul3-derived staple peptides are also able to bind the BTB of the pentameric KCTD5. Interestingly, the affinity of these peptides is of the same order of magnitude of that reported for the interaction of full-length Cul3 with some BTB containing proteins. Moreover, present data indicate that stapling endows these peptides with an increased serum stability. Altogether, these findings indicate that the designed stapled peptides can efficiently mimic protein-protein interactions and are potentially able to modulate fundamental biological processes involving Cul3. PMID:25848797

Dual-acting stapled peptides target both HIV-1 entry and assembly

PubMed Central

2013-01-01

Background Previously, we reported the conversion of the 12-mer linear and cell-impermeable peptide CAI to a cell-penetrating peptide NYAD-1 by using an i,i + 4 hydrocarbon stapling technique and confirmed its binding to the C-terminal domain (CTD) of the HIV-1 capsid (CA) protein with an improved affinity (Kd ~ 1 μM) compared to CAI (Kd ~ 15 μM). NYAD-1 disrupts the formation of both immature- and mature-like virus particles in in vitro and cell-based assembly assays. In addition, it displays potent anti-HIV-1 activity in cell culture against a range of laboratory-adapted and primary HIV-1 isolates. Results In this report, we expanded the study to i,i + 7 hydrocarbon-stapled peptides to delineate their mechanism of action and antiviral activity. We identified three potent inhibitors, NYAD-36, -66 and -67, which showed strong binding to CA in NMR and isothermal titration calorimetry (ITC) studies and disrupted the formation of mature-like particles. They showed typical α-helical structures and penetrated cells; however, the cell penetration was not as efficient as observed with the i,i + 4 peptides. Unlike NYAD-1, the i,i + 7 peptides did not have any effect on virus release; however, they impaired Gag precursor processing. HIV-1 particles produced in the presence of these peptides displayed impaired infectivity. Consistent with an effect on virus entry, selection for viral resistance led to the emergence of two mutations in the gp120 subunit of the viral envelope (Env) glycoprotein, V120Q and A327P, located in the conserved region 1 (C1) and the base of the V3 loop, respectively. Conclusion The i,i + 7 stapled peptides derived from CAI unexpectedly target both CA and the V3 loop of gp120. This dual-targeted activity is dependent on their ability to penetrate cells as well as their net charge. This mechanistic revelation will be useful in further modifying these peptides as potent anti-HIV-1 agents. PMID:24237936

Development and Testing of a 212Pb/212Bi Peptide for Targeting Metastatic Melanoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fisher, Darrell R.

2012-10-25

The purpose of this project is to develop a new radiolabeled peptide for imaging and treating metastatic melanoma. The immunoconjugate consists of a receptor-specific peptide that targets melanoma cells. The beta-emitter lead-212 (half-life = 10.4 hours) is linked by coordination chemistry to the peptide. After injection, the peptide targets melanoma receptors on the surfaces of melanoma cells. Lead-212 decays to the alpha-emitter bismuth-212 (half-life = 60 minutes). Alpha-particles that hit melanoma cell nuclei are likely to kill the melanoma cell. For cancer cell imaging, the lead-212 is replaced by lead-203 (half-life = 52 hours). Lead-203 emits 279 keV photons (80.1%more » abundance) that can be imaged and measured for biodistribution analysis, cancer imaging, and quantitative dosimetry.« less

Selective targeting of G-protein-coupled receptor subtypes with venom peptides.

PubMed

Näreoja, K; Näsman, J

2012-02-01

The G-protein-coupled receptor (GPCR) family is one of the largest gene superfamilies with approx. 370 members responding to endogenous ligands in humans and a roughly equal amount of receptors sensitive to external stimuli from the surrounding. A number of receptors from this superfamily are well recognized targets for medical treatment of various disease conditions, whereas for many others the potential medical benefit of interference is still obscure. A general problem associated with GPCR research and therapeutics is the insufficient specificity of available ligands to differentiate between closely homologous receptor subtypes. In this context, venom peptides could make a significant contribution to the development of more specific drugs. Venoms from certain animals specialized in biochemical hunting contain a mixture of molecules that are directed towards a variety of membrane proteins. Peptide toxins isolated from these mixtures usually exhibit high specificity for their targets. Muscarinic toxins found from mamba snakes attracted much attention during the 1990s. These are 65-66 amino acid long peptides with a structural three-finger folding similar to the α-neurotoxins and they target the muscarinic acetylcholine receptors in a subtype-selective manner. Recently, several members of the three-finger toxins from mamba snakes as well as conotoxins from marine cone snails have been shown to selectively interact with subtypes of adrenergic receptors. In this review, we will discuss the GPCR-directed peptide toxins found from different venoms and how some of these can be useful in exploring specific roles of receptor subtypes. © 2011 The Authors. Acta Physiologica © 2011 Scandinavian Physiological Society.

Multi-modal in cellulo evaluation of NPR-C targeted C-ANF-peptide and C-ANF-comb nanoparticles

NASA Astrophysics Data System (ADS)

Shokeen, Monica; Pressly, Eric; Connal, Luke; Liu, Yongjian; Hawker, Craig J.; Woodard, Pamela K.; Anderson, Carolyn J.; Achilefu, Samuel; Welch, Michael J.

2012-03-01

Natriuretic peptides (NPs) are clinical markers of heart disease that have anti-proliferative and anti-migratory effects on vascular smooth-muscle cells (VSMCs). In atherosclerosis, NPs participate in vascular remodeling, where the expression of NP clearance receptors (NPR-Cs) is upregulated both in the endothelium and in VSMCs[1-3]. In this study, we investigated the enhanced targeting potential of novel multifunctional nanoprobes conjugated with multiple copies of a C-type atrial natriuretic factor (C-ANF) peptide fragment to target NPR-C transfected cells. The cell binding results of the NPR-C targeted nanoprobes were compared with that of the C-ANF peptide fragment alone. The nanoprobe and peptide structures contain the chelator DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) for labeling with the PET tracer, 64Cu, for radioactive assays and luminescent Eu (III) for confocal cell imaging. Cell assays performed with the radioactive nanoprobe and peptide demonstrated higher cell binding of the targeted nanoprobe comapred with the peptide alone (8.63+/-1.67 vs. 1.13+/-0.06). The targeting specificity of both moieties was tested by using the control cell lines NPR-A and NPR-B, and receptor mediated uptake was demonstrated by reduced uptake in the presence of excess unlabeled respective probes.

Egg and Soy-Derived Peptides and Hydrolysates: A Review of Their Physiological Actions against Diabetes and Obesity.

PubMed

C de Campos Zani, Stepheny; Wu, Jianping; B Chan, Catherine

2018-04-28

Type 2 diabetes and obesity are two chronic conditions associated with the metabolic syndrome and their prevalences are increasing worldwide. The investigation of food protein-derived bioactive peptides that can improve the pathophysiology of diabetes or obesity while causing minimal side effects is desired. Egg and soy proteins generate bioactive peptides with multiple biological effects, exerting nutritional and physiological benefits. This review focuses on the anti-diabetic and anti-obesity effects of egg- and soy-derived peptides and hydrolysates in vivo and in vitro relevant to these conditions. Studies using the intact protein were considered only when comparing the results with the hydrolysate or peptides. In vivo evidence suggests that bioactive peptides from egg and soy can potentially be used to manage elements of glucose homeostasis in metabolic syndrome; however, the mechanisms of action on glucose and insulin metabolism, and the interaction between peptides and their molecular targets remain unclear. Optimizing the production of egg- and soy-derived peptides and standardizing the physiological models to study their effects on diabetes and obesity could help to clarify the effects of these bioactive peptides in metabolic syndrome-related conditions.

The use of a proteinaceous "cushion" with a polystyrene-binding peptide tag to control the orientation and function of a target peptide adsorbed to a hydrophilic polystyrene surface.

PubMed

Imanaka, Hiroyuki; Yamadzumi, Daisuke; Yanagita, Keisuke; Ishida, Naoyuki; Nakanishi, Kazuhiro; Imamura, Koreyoshi

2016-03-01

In immobilizing target biomolecules on a solid surface, it is essential (i) to orient the target moiety in a preferred direction and (ii) to avoid unwanted interactions of the target moiety including with the solid surface. The preferred orientation of the target moiety can be achieved by genetic conjugation of an affinity peptide tag specific to the immobilization surface. Herein, we report on a strategy for reducing the extent of direct interaction between the target moiety and surface in the immobilization of hexahistidine peptide (6His) and green fluorescent protein (GFP) on a hydrophilic polystyrene (PS) surface: Ribonuclease HII from Thermococcus kodakaraensis (cHII) was genetically inserted as a "cushion" between the PS-affinity peptide tag and target moiety. The insertion of a cushion protein resulted in a considerably stronger immobilization of target biomolecules compared to conjugation with only a PS affinity peptide tag, resulting in a substantially enhanced accessibility of the detection antibody to the target 6His peptide. The fluorescent intensity of the GFP moiety was decreased by approximately 30% as the result of fusion with cHII and the PS-affinity peptide tag but was fully retained in the immobilization on the PS surface irrespective of the increased binding force. Furthermore, the fusion of cHII did not impair the stability of the target GFP moiety. Accordingly, the use of a proteinaceous cushion appears to be promising for the immobilization of functional biomolecules on a solid surface. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:527-534, 2016. © 2016 American Institute of Chemical Engineers.

Collagen mimetic peptide engineered M13 bacteriophage for collagen targeting and imaging in cancer.

PubMed

Jin, Hyo-Eon; Farr, Rebecca; Lee, Seung-Wuk

2014-11-01

Collagens are over-expressed in various human cancers and subsequently degraded and denatured by proteolytic enzymes, thus making them a target for diagnostics and therapeutics. Genetically engineered bacteriophage (phage) is a promising candidate for the development of imaging or therapeutic materials for cancer collagen targeting due to its promising structural features. We genetically engineered M13 phages with two functional peptides, collagen mimetic peptide and streptavidin binding peptide, on their minor and major coat proteins, respectively. The resulting engineered phage functions as a therapeutic or imaging material to target degraded and denatured collagens in cancerous tissues. We demonstrated that the engineered phages are able to target and label abnormal collagens expressed on A549 human lung adenocarcinoma cells after the conjugation with streptavidin-linked fluorescent agents. Our engineered collagen binding phage could be a useful platform for abnormal collagen imaging and drug delivery in various collagen-related diseases. Published by Elsevier Ltd.

PHEX Mimetic (SPR4-Peptide) Corrects and Improves HYP and Wild Type Mice Energy-Metabolism

PubMed Central

Zelenchuk, Lesya V.; Hedge, Anne-Marie; Rowe, Peter S. N.

2014-01-01

Context PHEX or DMP1 mutations cause hypophosphatemic-rickets and altered energy metabolism. PHEX binds to DMP1-ASARM-motif to form a complex with α5β3 integrin that suppresses FGF23 expression. ASARM-peptides increase FGF23 by disrupting the PHEX-DMP1-Integrin complex. We used a 4.2 kDa peptide (SPR4) that binds to ASARM-peptide/motif to study the DMP1-PHEX interaction and to assess SPR4 for the treatment of energy metabolism defects in HYP and potentially other bone-mineral disorders. Design Subcutaneously transplanted osmotic pumps were used to infuse SPR4-peptide or vehicle (VE) into wild-type mice (WT) and HYP-mice (PHEX mutation) for 4 weeks. Results SPR4 partially corrected HYP mice hypophosphatemia and increased serum 1.25(OH)2D3. Serum FGF23 remained high and PTH was unaffected. WT-SPR4 mice developed hypophosphatemia and hypercalcemia with increased PTH, FGF23 and 1.25(OH)2D3. SPR4 increased GAPDH HYP-bone expression 60× and corrected HYP-mice hyperglycemia and hypoinsulinemia. HYP-VE serum uric-acid (UA) levels were reduced and SPR4 infusion suppressed UA levels in WT-mice but not HYP-mice. SPR4 altered leptin, adiponectin, and sympathetic-tone and increased the fat mass/weight ratio for HYP and WT mice. Expression of perlipin-2 a gene involved in obesity was reduced in HYP-VE and WT-SPR4 mice but increased in HYP-SPR4 mice. Also, increased expression of two genes that inhibit insulin-signaling, ENPP1 and ESP, occurred with HYP-VE mice. In contrast, SPR4 reduced expression of both ENPP1 and ESP in WT mice and suppressed ENPP1 in HYP mice. Increased expression of FAM20C and sclerostin occurred with HYP-VE mice. SPR4 suppressed expression of FAM20C and sclerostin in HYP and WT mice. Conclusions ASARM peptides and motifs are physiological substrates for PHEX and modulate osteocyte PHEX-DMP1-α5β3-integrin interactions and thereby FGF23 expression. These interactions also provide a nexus that regulates bone and energy metabolism. SPR4 suppression of

Targeting regenerative exosomes to myocardial infarction using cardiac homing peptide

PubMed Central

Vandergriff, Adam; Huang, Ke; Shen, Deliang; Hu, Shiqi; Hensley, Michael Taylor; Caranasos, Thomas G.; Qian, Li; Cheng, Ke

2018-01-01

Rationale: Cardiac stem cell-derived exosomes have been demonstrated to promote cardiac regeneration following myocardial infarction in preclinical studies. Recent studies have used intramyocardial injection in order to concentrate exosomes in the infarct. Though effective in a research setting, this method is not clinically appealing due to its invasive nature. We propose the use of a targeting peptide, cardiac homing peptide (CHP), to target intravenously-infused exosomes to the infarcted heart. Methods: Exosomes were conjugated with CHP through a DOPE-NHS linker. Ex vivo targeting was analyzed by incubating organ sections with the CHP exosomes and analyzing with fluorescence microscopy. In vitro assays were performed on neonatal rat cardiomyocytes and H9C2 cells. For the animal study, we utilized an ischemia/reperfusion rat model. Animals were treated with either saline, scramble peptide exosomes, or CHP exosomes 24 h after surgery. Echocardiography was performed 4 h after surgery and 21 d after surgery. At 21 d, animals were sacrificed, and organs were collected for analysis. Results: By conjugating the exosomes with CHP, we demonstrate increased retention of the exosomes within heart sections ex vivo and in vitro with neonatal rat cardiomyocytes. In vitro studies showed improved viability, reduced apoptosis and increased exosome uptake when using CHP-XOs. Using an animal model of ischemia/reperfusion injury, we measured the heart function, infarct size, cellular proliferation, and angiogenesis, with improved outcomes with the CHP exosomes. Conclusions: Our results demonstrate a novel method for increasing delivery of for treatment of myocardial infarction. By targeting exosomes to the infarcted heart, there was a significant improvement in outcomes with reduced fibrosis and scar size, and increased cellular proliferation and angiogenesis. PMID:29556361

Biological Evaluation of 99mTc-HYNIC-EDDA/tricine-(Ser)-D4 Peptide for Tumor Targeting.

PubMed

Kazemi, Ziba; Zahmatkesh, Mona Haddad; Abedi, Seyed Mohammad; Hosseinimehr, Seyed Jalal

2017-08-24

D4 small peptide (Leu-Ala-Arg-Leu-Leu-Thr) was selected as an appropriate agent for specific targeting of epidermal growth factor receptor (EGFR). The aim of study was to investigate the 99mTc-labeled D4 peptide for non-small cell lung tumor targeting. HYNIC-(Ser)3-D4 peptide was labeled with 99mTc using mixture of tricine and ethylenediamine diacetic acid (EDDA) as co-ligands. The in vitro cellular uptake of radiolabeled peptide was evaluated by blocking test on human non-small cell lung cancer (A-549) cell line and its biodistribution was evaluated in A-549 xenografted nude mice. This conjugated peptide was labeled with 99mTc in high radiochemical purity and it was highly stable in buffer and serum. The un-blocked to blocked cellular radioactivity ratio was 4- fold that showed a specific binding of this radiolabeled peptide on A-549 cell. Animal biodistribution in A-549 xenografted nude mice showed rapid clearance from blood and other non-target organs. Tumor uptake values as %ID/g (percentage of injection dose per gram of tissue) were 2.47% and 1.30% at 1 and 4 h after injection. This study showed the 99mTc-EDDA/tricine-HYNIC-(Ser)3-D4 peptide had tumor targeting on the non-small cell lung tumor. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Halobacterium salinarum NRC-1 PeptideAtlas: toward strategies for targeted proteomics and improved proteome coverage.

PubMed

Van, Phu T; Schmid, Amy K; King, Nichole L; Kaur, Amardeep; Pan, Min; Whitehead, Kenia; Koide, Tie; Facciotti, Marc T; Goo, Young Ah; Deutsch, Eric W; Reiss, David J; Mallick, Parag; Baliga, Nitin S

2008-09-01

The relatively small numbers of proteins and fewer possible post-translational modifications in microbes provide a unique opportunity to comprehensively characterize their dynamic proteomes. We have constructed a PeptideAtlas (PA) covering 62.7% of the predicted proteome of the extremely halophilic archaeon Halobacterium salinarum NRC-1 by compiling approximately 636 000 tandem mass spectra from 497 mass spectrometry runs in 88 experiments. Analysis of the PA with respect to biophysical properties of constituent peptides, functional properties of parent proteins of detected peptides, and performance of different mass spectrometry approaches has highlighted plausible strategies for improving proteome coverage and selecting signature peptides for targeted proteomics. Notably, discovery of a significant correlation between absolute abundances of mRNAs and proteins has helped identify low abundance of proteins as the major limitation in peptide detection. Furthermore, we have discovered that iTRAQ labeling for quantitative proteomic analysis introduces a significant bias in peptide detection by mass spectrometry. Therefore, despite identifying at least one proteotypic peptide for almost all proteins in the PA, a context-dependent selection of proteotypic peptides appears to be the most effective approach for targeted proteomics.

Tumor-targeting delivery of herb-based drugs with cell-penetrating/tumor-targeting peptide-modified nanocarriers

PubMed Central

Kebebe, Dereje; Liu, Yuanyuan; Wu, Yumei; Vilakhamxay, Maikhone; Liu, Zhidong; Li, Jiawei

2018-01-01

Cancer has become one of the leading causes of mortality globally. The major challenges of conventional cancer therapy are the failure of most chemotherapeutic agents to accumulate selectively in tumor cells and their severe systemic side effects. In the past three decades, a number of drug delivery approaches have been discovered to overwhelm the obstacles. Among these, nanocarriers have gained much attention for their excellent and efficient drug delivery systems to improve specific tissue/organ/cell targeting. In order to enhance targeting efficiency further and reduce limitations of nanocarriers, nanoparticle surfaces are functionalized with different ligands. Several kinds of ligand-modified nanomedicines have been reported. Cell-penetrating peptides (CPPs) are promising ligands, attracting the attention of researchers due to their efficiency to transport bioactive molecules intracellularly. However, their lack of specificity and in vivo degradation led to the development of newer types of CPP. Currently, activable CPP and tumor-targeting peptide (TTP)-modified nanocarriers have shown dramatically superior cellular specific uptake, cytotoxicity, and tumor growth inhibition. In this review, we discuss recent advances in tumor-targeting strategies using CPPs and their limitations in tumor delivery systems. Special emphasis is given to activable CPPs and TTPs. Finally, we address the application of CPPs and/or TTPs in the delivery of plant-derived chemotherapeutic agents. PMID:29563797

Novel cyclo-peptides inhibit Ebola pseudotyped virus entry by targeting primed GP protein.

PubMed

Li, Quanjie; Ma, Ling; Yi, Dongrong; Wang, Han; Wang, Jing; Zhang, Yongxin; Guo, Ying; Li, Xiaoyu; Zhou, Jinming; Shi, Yi; Gao, George F; Cen, Shan

2018-07-01

Ebola virus (EBOV) causes fatal hemorrhagic fever with high death rates in human. Currently, there are no available clinically-approved prophylactic or therapeutic treatments. The recently solved crystal structure of cleavage-primed EBOV glycoprotein (GPcl) in complex with the C domain of endosomal protein Niemann-Pick C1 (NPC1) provides a new target for the development of EBOV entry inhibitors. In this work, a computational approach using docking and molecular dynamic simulations is carried out for the rational design of peptide inhibitors. A novel cyclo-peptide (Pep-3.3) was identified to target at the late stage of EBOV entry and exhibit specific inhibitory activity against EBOV-GP pseudotyped viruses, with 50% inhibitory concentration (IC50) of 5.1 μM. In vitro binding assay and molecular simulations revealed that Pep-3.3 binds to GPcl with a KD value of 69.7 μM, through interacting with predicted residues in the hydrophobic binding pocket of GPcl. Mutation of predicted residues T83 caused resistance to Pep-3.3 inhibition in viral infectivity, providing preliminary support for the model of the peptide binding to GPcl. This study demonstrates the feasibility of inhibiting EBOV entry by targeting GPcl with peptides. Copyright © 2018 Elsevier B.V. All rights reserved.

Targeting cancer metabolism: dietary and pharmacological interventions

PubMed Central

Vernieri, Claudio; Casola, Stefano; Foiani, Marco; Pietrantonio, Filippo; de Braud, Filippo; Longo, Valter

2016-01-01

Most tumors display oncogene-driven reprogramming of several metabolic pathways, which are crucial to sustain their growth and proliferation. In recent years, both dietary and pharmacological approaches that target deregulated tumor metabolism are beginning to be considered for clinical applications. Dietary interventions exploit the ability of nutrient-restricted conditions to exert broad biological effects, protecting normal cells, organs and systems, while sensitizing a wide variety of cancer cells to cytotoxic therapies. On the other hand, drugs targeting enzymes or metabolites of crucial metabolic pathways can be highly specific and effective, but must be matched with a responsive tumor, which might rapidly adapt. In this Review, we illustrate how dietary and pharmacological therapies differ in their effect on tumor growth, proliferation and metabolism, and discuss the available preclinical and clinical evidence in favor or against each of them. We also indicate, when appropriate, how to optimize future investigations on metabolic therapies on the basis of tumor- and patient-related characteristics. PMID:27872127

Targeted delivery of peptide-conjugated biocompatible gold nanoparticles into cancer cell nucleus

NASA Astrophysics Data System (ADS)

Qian, Wei; Curry, Taeyjuana; Che, Yong; Kopelman, Raoul

2013-02-01

Nucleus remains a significant target for nanoparticles with diagnostic and therapeutic applications because both genetic information of the cell and transcription machinery reside there. Novel therapeutic strategies (for example, gene therapy), enabled by safe and efficient delivery of nanoparticles and drug molecules into the nucleus, are heralded by many as the ultimate treatment for severe and intractable diseases. However, most nanomaterials and macromolecules are incapable of reaching the cell nucleus on their own, because of biological barriers carefully honed by evolution including cellular membrane and nuclear envelope. In this paper, we have demonstrated an approach of fabrication of biocompatible gold nanoparticle (Au NP)-based vehicles which can entering into cancer cell nucleus by modifying Au NPs with both PEG 5000 and two different peptides (RGD and nuclear localization signal (NLS) peptide). The Au NPs used were fabricated via femtosecond laser ablation of Au bulk target in deionized water. The Au NPs produced by this method provide chemical free, virgin surface, which allows us to carry out "Sequential Conjugation" to modify their surface with PEG 5000, RGD, and NLS. "Sequential Conjugation" described in this presentation is very critical for the fabrication of Au NP-based vehicles capable of entering into cancer cell nucleus as it enables the engineering and tuning surface chemistries of Au NPs by independently adjusting amounts of PEG and peptides bound onto surface of Au NPs so as to maximize their nuclear targeting performance and biocompatibility regarding the cell line of interest. Both optical microscopy and transmission electron microscopy (TEM) are used to confirm the in vitro targeted nuclear delivery of peptide-conjugated biocompatible Au NPs by showing their presence in the cancer cell nucleus.

Identification of peptide sequences that target to the brain using in vivo phage display.

PubMed

Li, Jingwei; Zhang, Qizhi; Pang, Zhiqing; Wang, Yuchen; Liu, Qingfeng; Guo, Liangran; Jiang, Xinguo

2012-06-01

Phage display technology could provide a rapid means for the discovery of novel peptides. To find peptide ligands specific for the brain vascular receptors, we performed a modified phage display method. Phages were recovered from mice brain parenchyma after administrated with a random 7-mer peptide library intravenously. A longer circulation time was arranged according to the biodistributive brain/blood ratios of phage particles. Following sequential rounds of isolation, a number of phages were sequenced and a peptide sequence (CTSTSAPYC, denoted as PepC7) was identified. Clone 7-1, which encodes PepC7, exhibited translocation efficiency about 41-fold higher than the random library phage. Immunofluorescence analysis revealed that Clone 7-1 had a significant superiority on transport efficiency into the brain compared with native M13 phage. Clone 7-1 was inhibited from homing to the brain in a dose-dependent fashion when cyclic peptides of the same sequence were present in a competition assay. Interestingly, the linear peptide (ATSTSAPYA, Pep7) and a scrambled control peptide PepSC7 (CSPATSYTC) did not compete with the phage at the same tested concentration (0.2-200 pg). Labeled by Cy5.5, PepC7 exhibited significant brain-targeting capability in in vivo optical imaging analysis. The cyclic conformation of PepC7 formed by disulfide bond, and the correct structure itself play a critical role in maintaining the selectivity and affinity for the brain. In conclusion, PepC7 is a promising brain-target motif never been reported before and it could be applied to targeted drug delivery into the brain.

Alterations of peptide metabolism and neuropeptidase activity in senile dementia of the Alzheimer's type.

PubMed

Waters, S M; Davis, T P

1997-04-24

Work in our laboratory has shown that in addition to previously characterized changes in the level of neuropeptides in SDAT brain, the activity of degradative enzymes responsible for peptide metabolism is also affected. In addition to other reported alterations in peptide metabolism, we have observed that SS-28 degradation is increased in Brodmann area 22 whereas substance P degradation is increased in temporal cortex. Changes in the degradation of these neuropeptides known to be affected in SDAT correlate well with alterations in the activity of specific neuropeptidases. Trypsin-like serine protease activity is increased in SDAT Brodmann area 22 which parallels the increased degradation of SS-28. The activity of MEP 24.15 is decreased in temporal cortex which corresponds to the decreased degradation of substance P. Changes in the activity of these degradative enzymes in SDAT brain can potentially affect the action of other neuropeptide substrates because the neuropeptidases discussed here terminate the action of several neuropeptides. As more neuropeptide and degradative peptidase alterations are discovered in SDAT, greater emphasis may be placed on the role that peptides and neuropeptidases play in the progression of SDAT.

Efficient Mitochondrial Glutamine Targeting Prevails Over Glioblastoma Metabolic Plasticity.

PubMed

Oizel, Kristell; Chauvin, Cynthia; Oliver, Lisa; Gratas, Catherine; Geraldo, Fanny; Jarry, Ulrich; Scotet, Emmanuel; Rabe, Marion; Alves-Guerra, Marie-Clotilde; Teusan, Raluca; Gautier, Fabien; Loussouarn, Delphine; Compan, Vincent; Martinou, Jean-Claude; Vallette, François M; Pecqueur, Claire

2017-10-15

Purpose: Glioblastoma (GBM) is the most common and malignant form of primary human brain tumor in adults, with an average survival at diagnosis of 18 months. Metabolism is a new attractive therapeutic target in cancer; however, little is known about metabolic heterogeneity and plasticity within GBM tumors. We therefore aimed to investigate metabolic phenotyping of primary cultures in the context of molecular tumor heterogeneity to provide a proof of concept for personalized metabolic targeting of GBM. Experimental Design: We have analyzed extensively several primary GBM cultures using transcriptomics, metabolic phenotyping assays, and mitochondrial respirometry. Results: We found that metabolic phenotyping clearly identifies 2 clusters, GLN High and GLN Low , mainly based on metabolic plasticity and glutamine (GLN) utilization. Inhibition of glutamine metabolism slows the in vitro and in vivo growth of GLN High GBM cultures despite metabolic adaptation to nutrient availability, in particular by increasing pyruvate shuttling into mitochondria. Furthermore, phenotypic and molecular analyses show that highly proliferative GLN High cultures are CD133 neg and display a mesenchymal signature in contrast to CD133 pos GLN Low GBM cells. Conclusions: Our results show that metabolic phenotyping identified an essential metabolic pathway in a GBM cell subtype, and provide a proof of concept for theranostic metabolic targeting. Clin Cancer Res; 23(20); 6292-304. ©2017 AACR . ©2017 American Association for Cancer Research.

In Vitro Mouse and Human Serum Stability of a Heterobivalent Dual-Target Probe That Has Strong Affinity to Gastrin-Releasing Peptide and Neuropeptide Y1 Receptors on Tumor Cells.

PubMed

Ghosh, Arijit; Raju, Natarajan; Tweedle, Michael; Kumar, Krishan

2017-02-01

Receptor-targeting radiolabeled molecular probes with high affinity and specificity are useful in studying and monitoring biological processes and responses. Dual- or multiple-targeting probes, using radiolabeled metal chelates conjugated to peptides, have potential advantages over single-targeting probes as they can recognize multiple targets leading to better sensitivity for imaging and radiotherapy when target heterogeneity is present. Two natural hormone peptide receptors, gastrin-releasing peptide (GRP) and Y1, are specifically interesting as their expression is upregulated in most breast and prostate cancers. One of our goals has been to develop a dual-target probe that can bind both GRP and Y1 receptors. Consequently, a heterobivalent dual-target probe, t-BBN/BVD15-DO3A (where a GRP targeting ligand J-G-Abz4-QWAVGHLM-NH 2 and Y1 targeting ligand INP-K [ɛ-J-(α-DO3A-ɛ-DGa)-K] YRLRY-NH 2 were coupled), that recognizes both GRP and Y1 receptors was synthesized, purified, and characterized in the past. Competitive displacement cell binding assay studies with the probe demonstrated strong affinity (IC 50 values given in parentheses) for GRP receptors in T-47D cells (18 ± 0.7 nM) and for Y1 receptors in MCF7 cells (80 ± 11 nM). As a further evaluation of the heterobivalent dual-target probe t-BBN/BVD15-DO3A, the objective of this study was to determine its mouse and human serum stability at 37°C. The in vitro metabolic degradation of the dual-target probe in mouse and human serum was studied by using a 153 Gd-labeled t-BBN/BVD15-DO3A and a high-performance liquid chromatography/radioisotope detector analytical method. The half-life (t 1/2 ) of degradation of the dual-target probe in mouse serum was calculated as 7 hours and only ∼20% degradation was seen after 6 hours incubation in human serum. The slow in vitro metabolic degradation of the dual-target probe can be compared with the degradation t 1/2 of the corresponding monomeric probes, BVD15

A dual-targeting liposome conjugated with transferrin and arginine-glycine-aspartic acid peptide for glioma-targeting therapy.

PubMed

Qin, Li; Wang, Cheng-Zheng; Fan, Hui-Jie; Zhang, Chong-Jian; Zhang, Heng-Wei; Lv, Min-Hao; Cui, Shu-DE

2014-11-01

The treatment of a brain glioma remains one of the most difficult challenges in oncology. In the present study a delivery system was developed for targeted drug delivery across the blood-brain barrier (BBB) to the brain cancer cells. A cyclic arginine-glycine-aspartic acid (RGD) peptide and transferrin (TF) were utilized as targeting ligands. Cyclic RGD peptides are specific targeting ligands of cancer cells and TFs are ligands that specifically target the BBB and cancer cells. Liposome (LP) was used to conjugate the cyclic RGD and TFs to establish the brain glioma cascade delivery system (RGD/TF-LP). The LPs were prepared by the thin film hydration method and physicochemical characterization was conducted. In vitro cell uptake and three-dimensional tumor spheroid penetration studies demonstrated that the system could target endothelial and tumor cells, as well as penetrate the tumor cells to reach the core of the tumor spheroids. The results of the in vivo imaging further demonstrated that the RGD/TF-LP provided the highest brain distribution. As a result, the paclitaxel-loaded RGD/TF-LP presents the best antiproliferative activity against C6 cells and tumor spheroids. In conclusion, the RGD/TF-LP may precisely target brain glioma, which may be valuable for glioma imaging and therapy.

Targeting the latest hallmark of cancer: another attempt at 'magic bullet' drugs targeting cancers' metabolic phenotype.

PubMed

Cuperlovic-Culf, M; Culf, A S; Touaibia, M; Lefort, N

2012-10-01

The metabolism of tumors is remarkably different from the metabolism of corresponding normal cells and tissues. Metabolic alterations are initiated by oncogenes and are required for malignant transformation, allowing cancer cells to resist some cell death signals while producing energy and fulfilling their biosynthetic needs with limiting resources. The distinct metabolic phenotype of cancers provides an interesting avenue for treatment, potentially with minimal side effects. As many cancers show similar metabolic characteristics, drugs targeting the cancer metabolic phenotype are, perhaps optimistically, expected to be 'magic bullet' treatments. Over the last few years there have been a number of potential drugs developed to specifically target cancer metabolism. Several of these drugs are currently in clinical and preclinical trials. This review outlines examples of drugs developed for different targets of significance to cancer metabolism, with a focus on small molecule leads, chemical biology and clinical results for these drugs.

Targeting polyamine metabolism for cancer therapy and prevention

PubMed Central

Murray-Stewart, Tracy R.; Woster, Patrick M.; Casero, Robert A.

2017-01-01

The chemically simple, biologically complex eukaryotic polyamines, spermidine and spermine, are positively charged alkylamines involved in many crucial cellular processes. Along with their diamine precursor putrescine, their normally high intracellular concentrations require fine attenuation by multiple regulatory mechanisms to keep these essential molecules within strict physiologic ranges. Since the metabolism of and requirement for polyamines are frequently dysregulated in neoplastic disease, the metabolic pathway and functions of polyamines provide rational drug targets; however, these targets have been difficult to exploit for chemotherapy. It is the goal of this article to review the latest findings in the field that demonstrate the potential utility of targeting the metabolism and function of polyamines as strategies for both chemotherapy and, possibly more importantly, chemoprevention. PMID:27679855

Targeting iron metabolism in drug discovery and delivery

PubMed Central

Crielaard, Bart J.; Lammers, Twan; Rivella, Stefano

2017-01-01

Iron fulfils a central role in many essential biochemical processes in human physiology, which makes proper processing of iron crucial. Although iron metabolism is subject to relatively strict physiological control, in recent years numerous disorders, such as cancer and neurodegenerative diseases, have been linked to deregulated iron homeostasis. Because of its involvement in the pathogenesis of these diseases, iron metabolism constitutes a promising and largely unexploited therapeutic target for the development of new pharmacological treatments. Several iron metabolism-targeted therapies are already under clinical evaluation for haematological disorders, and these and newly developed therapeutic agents will likely have substantial benefit in the clinical management of iron metabolism-associated diseases, for which few efficacious treatments are often available. PMID:28154410

Acetohydroxy acid synthase is a target for leucine containing peptide toxicity in Escherichia coli.

PubMed Central

Gollop, N; Tavori, H; Barak, Z

1982-01-01

Acetohydroxy acid synthase from a mutant resistant to leucine-containing peptides was insensitive to leucine inhibition. It is concluded that acetohydroxy acid synthase is a target for the toxicity of the high concentrations of leucine brought into Escherichia coli K-12 by leucine-containing peptides. PMID:7033214

Targeted Lymphoma Cell Death by Novel Signal Transduction Modifications

DTIC Science & Technology

2009-07-01

metabolic activity), and iPET imaging (a highly sensitive method to assess in vivo tumor-targeting). We have b egun to de velop the DOTA conj...inhibition augmented the cytotoxic potential of peptide 5. • We have begun to develop DOTA -c onjugated peptide 5 and 41 in anticipation of immuno-PET

Targeting of peptide conjugated magnetic nanoparticles to urokinase plasminogen activator receptor (uPAR) expressing cells

NASA Astrophysics Data System (ADS)

Hansen, Line; Unmack Larsen, Esben Kjær; Nielsen, Erik Holm; Iversen, Frank; Liu, Zhuo; Thomsen, Karen; Pedersen, Michael; Skrydstrup, Troels; Nielsen, Niels Chr.; Ploug, Michael; Kjems, Jørgen

2013-08-01

Ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles are currently being used as a magnetic resonance imaging (MRI) contrast agent in vivo, mainly by their passive accumulation in tissues of interest. However, a higher specificity can ideally be achieved when the nanoparticles are targeted towards cell specific receptors and this may also facilitate specific drug delivery by an enhanced target-mediated endocytosis. We report efficient peptide-mediated targeting of magnetic nanoparticles to cells expressing the urokinase plasminogen activator receptor (uPAR), a surface biomarker for poor patient prognosis shared by several cancers including breast, colorectal, and gastric cancers. Conjugation of a uPAR specific targeting peptide onto polyethylene glycol (PEG) coated USPIO nanoparticles by click chemistry resulted in a five times higher uptake in vitro in a uPAR positive cell line compared to nanoparticles carrying a non-binding control peptide. In accordance with specific receptor-mediated recognition, a low uptake was observed in the presence of an excess of ATF, a natural ligand for uPAR. The uPAR specific magnetic nanoparticles can potentially provide a useful supplement for tumor patient management when combined with MRI and drug delivery.Ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles are currently being used as a magnetic resonance imaging (MRI) contrast agent in vivo, mainly by their passive accumulation in tissues of interest. However, a higher specificity can ideally be achieved when the nanoparticles are targeted towards cell specific receptors and this may also facilitate specific drug delivery by an enhanced target-mediated endocytosis. We report efficient peptide-mediated targeting of magnetic nanoparticles to cells expressing the urokinase plasminogen activator receptor (uPAR), a surface biomarker for poor patient prognosis shared by several cancers including breast, colorectal, and gastric cancers. Conjugation of a uPAR specific

Targeted Delivery of an Antigenic Peptide to the Endoplasmic Reticulum: Application for Development of a Peptide Therapy for Ankylosing Spondylitis

PubMed Central

Yu, Hui-Chun; Lu, Ming-Chi; Li, Chin; Huang, Hsien-Lu; Huang, Kuang-Yung; Liu, Su-Qin; Lai, Ning-Sheng; Huang, Hsien-Bin

2013-01-01

The development of suitable methods to deliver peptides specifically to the endoplasmic reticulum (ER) can provide some potential therapeutic applications of such peptides. Ankylosing spondylitis (AS) is strongly associated with the expression of human leukocytic antigen-B27 (HLA-B27). HLA-B27 heavy chain (HC) has a propensity to fold slowly resulting in the accumulation of misfolded HLA-B27 HC in the ER, triggering the unfolded protein response, and forming a homodimer, (B27-HC)2. Natural killer cells and T-helper 17 cells are then activated, contributing to the major pathogenic potentials of AS. The HLA-B27 HC is thus an important target, and delivery of an HLA-B27-binding peptide to the ER capable of promoting HLA-B27 HC folding is a potential mechanism for AS therapy. Here, we demonstrate that a His6-ubiquitin-tagged Tat-derived peptide (THU) can deliver an HLA-B27-binding peptide to the ER promoting HLA-B27 HC folding. The THU-HLA-B27-binding peptide fusion protein crossed the cell membrane to the cytosol through the Tat-derived peptide. The HLA-B27-binding peptide was specifically cleaved from THU by cytosolic ubiquitin C-terminal hydrolases and subsequently transported into the ER by the transporter associated with antigen processing. This approach has potential application in the development of peptide therapy for AS. PMID:24155957

A new strategy for the preparation of peptide-targeted technetium and rhenium radiopharmaceuticals. The automated solid-phase synthesis, characterization, labeling, and screening of a peptide-ligand library targeted at the formyl peptide receptor.

PubMed

Stephenson, Karin A; Banerjee, Sangeeta Ray; Sogbein, Oyebola O; Levadala, Murali K; McFarlane, Nicole; Boreham, Douglas R; Maresca, Kevin P; Babich, John W; Zubieta, Jon; Valliant, John F

2005-01-01

A new solid-phase synthetic methodology was developed that enables libraries of peptide-based Tc(I)/Re(I) radiopharmaceuticals to be prepared using a conventional automated peptide synthesizer. Through the use of a tridentate ligand derived from N-alpha-Fmoc-l-lysine, which we refer to as a single amino acid chelate (SAAC), a series of 12 novel bioconjugates [R-NH(CO)ZLF(SAAC)G, R = ethyl, isopropyl, n-propyl, tert-butyl, n-butyl, benzyl; Z = Met, Nle] that are designed to target the formyl peptide receptor (FPR) were prepared. Construction of the library was carried out in a multiwell format on an Advanced ChemTech 348 peptide synthesizer where multi-milligram quantities of each peptide were isolated in high purity without HPLC purification. After characterization, the library components were screened for their affinity for the FPR receptor using flow cytometry where the K(d) values were found to be in the low micromolar range (0.5-3.0 microM). Compound 5j was subsequently labeled with (99m)Tc(I) and the product isolated in high radiochemical yield using a simple Sep-Pak purification procedure. The retention time of the labeled compound matched that of the fully characterized Re-analogue which was prepared through the use of the same solid-phase synthesis methodology that was used to construct the library. The work reported here is a rare example of a method by which libraries of peptide-ligand conjugates and their rhenium complexes can be prepared.

Targeting diverse protein–protein interaction interfaces with α/β-peptides derived from the Z-domain scaffold

DOE Office of Scientific and Technical Information (OSTI.GOV)

Checco, James W.; Kreitler, Dale F.; Thomas, Nicole C.

Peptide-based agents derived from well-defined scaffolds offer an alternative to antibodies for selective and high-affinity recognition of large and topologically complex protein surfaces. In this paper, we describe a strategy for designing oligomers containing both α- and β-amino acid residues (“α/β-peptides”) that mimic several peptides derived from the three-helix bundle “Z-domain” scaffold. We show that α/β-peptides derived from a Z-domain peptide targeting vascular endothelial growth factor (VEGF) can structurally and functionally mimic the binding surface of the parent peptide while exhibiting significantly decreased susceptibility to proteolysis. The tightest VEGF-binding α/β-peptide inhibits the VEGF 165-induced proliferation of human umbilical vein endothelialmore » cells. We demonstrate the versatility of this strategy by showing how principles underlying VEGF signaling inhibitors can be rapidly extended to produce Z-domain–mimetic α/β-peptides that bind to two other protein partners, IgG and tumor necrosis factor-α. Because well-established selection techniques can identify high-affinity Z-domain derivatives from large DNA-encoded libraries, our findings should enable the design of biostable α/β-peptides that bind tightly and specifically to diverse targets of biomedical interest. Finally, such reagents would be useful for diagnostic and therapeutic applications.« less

Targeting diverse protein–protein interaction interfaces with α/β-peptides derived from the Z-domain scaffold

DOE PAGES

Checco, James W.; Kreitler, Dale F.; Thomas, Nicole C.; ...

2015-03-30

Peptide-based agents derived from well-defined scaffolds offer an alternative to antibodies for selective and high-affinity recognition of large and topologically complex protein surfaces. In this paper, we describe a strategy for designing oligomers containing both α- and β-amino acid residues (“α/β-peptides”) that mimic several peptides derived from the three-helix bundle “Z-domain” scaffold. We show that α/β-peptides derived from a Z-domain peptide targeting vascular endothelial growth factor (VEGF) can structurally and functionally mimic the binding surface of the parent peptide while exhibiting significantly decreased susceptibility to proteolysis. The tightest VEGF-binding α/β-peptide inhibits the VEGF 165-induced proliferation of human umbilical vein endothelialmore » cells. We demonstrate the versatility of this strategy by showing how principles underlying VEGF signaling inhibitors can be rapidly extended to produce Z-domain–mimetic α/β-peptides that bind to two other protein partners, IgG and tumor necrosis factor-α. Because well-established selection techniques can identify high-affinity Z-domain derivatives from large DNA-encoded libraries, our findings should enable the design of biostable α/β-peptides that bind tightly and specifically to diverse targets of biomedical interest. Finally, such reagents would be useful for diagnostic and therapeutic applications.« less

Peptide and low molecular weight proteins based kidney targeted drug delivery systems.

PubMed

Xu, Pengfei; Zhang, Hailiang; Dang, Ruili; Jiang, Pei

2018-05-30

Renal disease is a worldwide public health problem, and unfortunately, the therapeutic index of regular drugs is limited. Thus, it is a great need to develop effective treatment strategies. Among the reported strategies, kidney-targeted drug delivery system is a promising method to increase renal efficacy and reduce extra-renal toxicity. In recent years, working as vehicles for targeted drug delivery, low molecular weight proteins (LMWP) and peptide have received immense attention due to their many advantages, such as selective accumulation in kidney, high drug loading capability, control over routes of biodegradation, convenience in modification at the amino terminus, and good biocompatibility. In this review, we describe the current LMWP and peptide carriers for kidney targeted drug delivery systems. In addition, we discuss different linking strategies between carriers and drugs. Furthermore, we briefly outline the current status and attempt to give an outlook on the further study. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Lipid raft-like liposomes used for targeted delivery of a chimeric entry-inhibitor peptide with anti-HIV-1 activity.

PubMed

Gómara, María José; Pérez-Pomeda, Ignacio; Gatell, José María; Sánchez-Merino, Victor; Yuste, Eloisa; Haro, Isabel

2017-02-01

The work reports the design and synthesis of a chimeric peptide that is composed of the peptide sequences of two entry inhibitors which target different sites of HIV-1 gp41. The chimeric peptide offers the advantage of targeting two gp41 regions simultaneously: the fusion peptide and the loop both of which are membrane active and participate in the membrane fusion process. We therefore use lipid raft-like liposomes as a tool to specifically direct the chimeric inhibitor peptide to the membrane domains where the HIV-1 envelope protein is located. Moreover, the liposomes that mimic the viral membrane composition protect the chimeric peptide against proteolytic digestion thereby increasing the stability of the peptide. The described liposome preparations are suitable nanosystems for managing hydrophobic entry-inhibitor peptides as putative therapeutics. Copyright © 2016 Elsevier Inc. All rights reserved.

RGD based peptide amphiphiles as drug carriers for cancer targeting

NASA Astrophysics Data System (ADS)

Saraf, Poonam S.

Specific interactions of ligands with receptors is one of the approaches for active targeting of anticancer drugs to cancer cells. Over expression of integrin receptors is a physiological manifestation in several cancers and is associated with cancer progression and metastasis, which makes it an attractive target for cancer chemotherapy. The peptide sequence for this integrin recognition is the Arg-Gly-Asp (RGD). Self-assembly offers a unique way of presenting ligands to target receptors for recognition and binding. This study focuses on development of integrin specific peptide amphiphile self-assemblies as carriers for targeted delivery of paclitaxel to αvbeta 3 integrin overexpressing cancers. Amphiphiles composed of conjugates of different analogs of RGD (linear, cyclic or glycosylated) and aliphatic fatty acid with or without 8-amino-3,6-dioxaoctanoic acid (ADA) as linker were synthesized and characterized. The amphiphiles exhibited Critical Micellar Concentration in the range of 7-30 μM. Transmission electron microscopy images revealed the formation of spherical micelles in the size range of 10-40 nm. Forster Resonance Energy Transfer studies revealed entrapment of hydrophobic dyes within a tight micellar core and provided information regarding the cargo exchange within micelles. The RGD micelles exhibited competitive binding with 55% displacement of a bound fluorescent probe by the cyclic RGD micelles. The internalization of fluorescein isothiocynate (FITC) loaded RGD micelles was significantly higher in A2058 melanoma cells compared to free FITC within 20 minutes of incubation at 37°C. The same micelles showed significantly lower internalization at 4°C and on pretreatment with 0.45M sucrose confirming endocytotic uptake of the RGD micellar carriers. The IC50 of paclitaxel in A2058 melanoma cells was lower when treated within RGD micelles as compared to treatment of free drug. On the other hand, IC50 values increased by 2 to 9 fold for micellar treatment

Transport and metabolism of delta sleep-inducing peptide in cultured human intestinal epithelial cell monolayers.

PubMed

Augustijns, P F; Borchardt, R T

1995-12-01

A cultured human intestinal epithelial (Caco-2) cell monolayer was used to study the transport and metabolism of delta sleep-inducing peptide [DSIP (Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu)]. DSIP is of interest because it has been reported to be capable of permeating biological barriers (e.g. blood-brain barrier), and this property has been related to its solution conformation. When applied to the apical (AP) side of Caco-2 cell monolayers, DSIP was rapidly metabolized (8.2 +/- 1.1% remaining after a 2-hr incubation), affording Trp as the major metabolite and Trp-Ala as a minor metabolite. When DSIP was added to the basolateral (BL) side of the monolayer, the same metabolites were detected, but the peptide was more stable (70.6 +/- 3.0% remaining after a 2-hr incubation). Inclusion of bestatin, an inhibitor of aminopeptidases, at concentrations up to 0.29 mM with DSIP on the AP side of the Caco-2 cell monolayer increased the stability of the peptide only slightly but dramatically altered the distribution of the metabolites (Trp-Ala became the major metabolite, and Trp became the minor metabolite). Inclusion of other aminopeptidase inhibitors (e.g. amastatin, puromycin) alone, dipeptidylpeptidase IV inhibitors (e.g. diprotin A, Gly-Pro) alone, inhibitors of proteases that require heavy metals for proper activity (e.g. EDTA, 1,10-phenanthroline) alone, or cysteine protease inhibitors (e.g. leupeptin) alone did not lead to significant stabilization of the peptide. However, inclusion of a combination of 0.29 mM bestatin and 1 mM diprotin A with DSIP on the AP side of the monolayers resulted in a substantial increase in the stability of the peptide (83.2 +/- 3.7% remaining after a 2-hr incubation). However, under these conditions, a new metabolite (Trp-Ala-Gly-Gly-Asp-Ala-Ser) was observed with a formation that could be inhibited by inclusion of 1 mM captopril, an inhibitor of peptidyl dipeptidase A. Therefore, the stability of DSIP could be further increased (95.1 +/- 1

Peptide ligands targeting integrin alpha3beta1 in non-small cell lung cancer.

PubMed

Lau, Derick; Guo, Linlang; Liu, Ruiwu; Marik, Jan; Lam, Kit

2006-06-01

Lung cancer is one of the most common cancers and is the leading cause of cancer death. We wish to identify peptide ligands for unique cell surface receptors of non-small lung cancer with the hope of developing these ligands as diagnostic and therapeutic agents. Using the method of 'one-bead one-peptide' combinatorial chemistry, a library of random cyclic octapeptides was synthesized on polystyrene beads. This library was used to screen for peptides that promoted attachment of lung adenocarcinoma cells employing a 'cell-growth-on-bead' assay. Consensus peptide sequences of cNGXGXXc were identified. These peptides promoted cell adhesion by targeting integrin alpha3beta1 over-expressed in non-small lung cancer cells. These peptide beads can be applied to capture cancer cells in malignant pleural fluid for purpose of diagnosis of lung cancer.

Improved prediction of peptide detectability for targeted proteomics using a rank-based algorithm and organism-specific data.

PubMed

Qeli, Ermir; Omasits, Ulrich; Goetze, Sandra; Stekhoven, Daniel J; Frey, Juerg E; Basler, Konrad; Wollscheid, Bernd; Brunner, Erich; Ahrens, Christian H

2014-08-28

The in silico prediction of the best-observable "proteotypic" peptides in mass spectrometry-based workflows is a challenging problem. Being able to accurately predict such peptides would enable the informed selection of proteotypic peptides for targeted quantification of previously observed and non-observed proteins for any organism, with a significant impact for clinical proteomics and systems biology studies. Current prediction algorithms rely on physicochemical parameters in combination with positive and negative training sets to identify those peptide properties that most profoundly affect their general detectability. Here we present PeptideRank, an approach that uses learning to rank algorithm for peptide detectability prediction from shotgun proteomics data, and that eliminates the need to select a negative dataset for the training step. A large number of different peptide properties are used to train ranking models in order to predict a ranking of the best-observable peptides within a protein. Empirical evaluation with rank accuracy metrics showed that PeptideRank complements existing prediction algorithms. Our results indicate that the best performance is achieved when it is trained on organism-specific shotgun proteomics data, and that PeptideRank is most accurate for short to medium-sized and abundant proteins, without any loss in prediction accuracy for the important class of membrane proteins. Targeted proteomics approaches have been gaining a lot of momentum and hold immense potential for systems biology studies and clinical proteomics. However, since only very few complete proteomes have been reported to date, for a considerable fraction of a proteome there is no experimental proteomics evidence that would allow to guide the selection of the best-suited proteotypic peptides (PTPs), i.e. peptides that are specific to a given proteoform and that are repeatedly observed in a mass spectrometer. We describe a novel, rank-based approach for the prediction

Defining the wheat gluten peptide fingerprint via a discovery and targeted proteomics approach.

PubMed

Martínez-Esteso, María José; Nørgaard, Jørgen; Brohée, Marcel; Haraszi, Reka; Maquet, Alain; O'Connor, Gavin

2016-09-16

Accurate, reliable and sensitive detection methods for gluten are required to support current EU regulations. The enforcement of legislative levels requires that measurement results are comparable over time and between methods. This is not a trivial task for gluten which comprises a large number of protein targets. This paper describes a strategy for defining a set of specific analytical targets for wheat gluten. A comprehensive proteomic approach was applied by fractionating wheat gluten using RP-HPLC (reversed phase high performance liquid chromatography) followed by a multi-enzymatic digestion (LysC, trypsin and chymotrypsin) with subsequent mass spectrometric analysis. This approach identified 434 peptide sequences from gluten. Peptides were grouped based on two criteria: unique to a single gluten protein sequence; contained known immunogenic and toxic sequences in the context of coeliac disease. An LC-MS/MS method based on selected reaction monitoring (SRM) was developed on a triple quadrupole mass spectrometer for the specific detection of the target peptides. The SRM based screening approach was applied to gluten containing cereals (wheat, rye, barley and oats) and non-gluten containing flours (corn, soy and rice). A unique set of wheat gluten marker peptides were identified and are proposed as wheat specific markers. The measurement of gluten in processed food products in support of regulatory limits is performed routinely. Mass spectrometry is emerging as a viable alternative to ELISA based methods. Here we outline a set of peptide markers that are representative of gluten and consider the end user's needs in protecting those with coeliac disease. The approach taken has been applied to wheat but can be easily extended to include other species potentially enabling the MS quantification of different gluten containing species from the identified markers. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Development of Peritoneal Tumor-Targeting Vector by In Vivo Screening with a Random Peptide-Displaying Adenovirus Library

PubMed Central

Yoshida, Kimiko; Goto, Naoko; Ohnami, Shumpei; Aoki, Kazunori

2012-01-01

The targeting of gene transfer at the cell-entry level is one of the most attractive challenges in vector development. However, attempts to redirect adenovirus vectors to alternative receptors by engineering the capsid-coding region have shown limited success, because the proper targeting ligands on the cells of interest are generally unknown. To overcome this limitation, we have constructed a random peptide library displayed on the adenoviral fiber knob, and have successfully selected targeted vectors by screening the library on cancer cell lines in vitro. The infection of targeted vectors was considered to be mediated by specific receptors on target cells. However, the expression levels and kinds of cell surface receptors may be substantially different between in vitro culture and in vivo tumor tissue. Here, we screened the peptide display-adenovirus library in the peritoneal dissemination model of AsPC-1 pancreatic cancer cells. The vector displaying a selected peptide (PFWSGAV) showed higher infectivity in the AsPC-1 peritoneal tumors but not in organs and other peritoneal tumors as compared with a non-targeted vector. Furthermore, the infectivity of the PFWSGAV-displaying vector for AsPC-1 peritoneal tumors was significantly higher than that of a vector displaying a peptide selected by in vitro screening, indicating the usefulness of in vivo screening in exploring the targeting vectors. This vector-screening system can facilitate the development of targeted adenovirus vectors for a variety of applications in medicine. PMID:23029088

Tumor-targeting peptide conjugated pH-responsive micelles as a potential drug carrier for cancer therapy.

PubMed

Wu, Xiang Lan; Kim, Jong Ho; Koo, Heebeom; Bae, Sang Mun; Shin, Hyeri; Kim, Min Sang; Lee, Byung-Heon; Park, Rang-Woon; Kim, In-San; Choi, Kuiwon; Kwon, Ick Chan; Kim, Kwangmeyung; Lee, Doo Sung

2010-02-17

Herein, we prepared tumor-targeting peptide (AP peptide; CRKRLDRN) conjugated pH-responsive polymeric micelles (pH-PMs) in cancer therapy by active and pH-responsive tumor targeting delivery systems, simultaneously. The active tumor targeting and tumoral pH-responsive polymeric micelles were prepared by mixing AP peptide conjugated PEG-poly(d,l-lactic acid) block copolymer (AP-PEG-PLA) into the pH-responsive micelles of methyl ether poly(ethylene glycol) (MPEG)-poly(beta-amino ester) (PAE) block copolymer (MPEG-PAE). These mixed amphiphilic block copolymers were self-assembled to form stable AP peptide-conjugated and pH-responsive AP-PEG-PLA/MPEG-PAE micelles (AP-pH-PMs) with an average size of 150 nm. The AP-pH-PMs containing 10 wt % of AP-PEG-PLA showed a sharp pH-dependent micellization/demicellization transition at the tumoral acid pH. Also, they presented the pH-dependent drug release profile at the acidic pH of 6.4. The fluorescence dye, TRITC, encapsulated AP-pH-PMs (TRITC-AP-pH-PMs) presented the higher tumor-specific targeting ability in vitro cancer cell culture system and in vivo tumor-bearing mice, compared to control pH-responsive micelles of MPEG-PAE. For the cancer therapy, the anticancer drug, doxorubicin (DOX), was efficiently encapsulated into the AP-pH-PMs (DOX-AP-pH-PMs) with a higher loading efficiency. DOX-AP-pH-PMs efficiently deliver anticancer drugs in MDA-MB231 human breast tumor-bearing mice, resulted in excellent anticancer therapeutic efficacy, compared to free DOX and DOX encapsulated MEG-PAE micelles, indicating the excellent tumor targeting ability of AP-pH-PMs. Therefore, these tumor-targeting peptide-conjugated and pH-responsive polymeric micelles have great potential application in cancer therapy.

Activatable iRGD-based peptide monolith: Targeting, internalization, and fluorescence activation for precise tumor imaging.

PubMed

Cho, Hong-Jun; Lee, Sung-Jin; Park, Sung-Jun; Paik, Chang H; Lee, Sang-Myung; Kim, Sehoon; Lee, Yoon-Sik

2016-09-10

A disulfide-bridged cyclic RGD peptide, named iRGD (internalizing RGD, c(CRGDK/RGPD/EC)), is known to facilitate tumor targeting as well as tissue penetration. After the RGD motif-induced targeting on αv integrins expressed near tumor tissue, iRGD encounters proteolytic cleavage to expose the CendR motif that promotes penetration into cancer cells via the interaction with neuropilin-1. Based on these proteolytic cleavage and internalization mechanism, we designed an iRGD-based monolithic imaging probe that integrates multiple functions (cancer-specific targeting, internalization and fluorescence activation) within a small peptide framework. To provide the capability of activatable fluorescence signaling, we conjugated a fluorescent dye to the N-terminal of iRGD, which was linked to the internalizing sequence (CendR motif), and a quencher to the opposite C-terminal. It turned out that fluorescence activation of the dye/quencher-conjugated monolithic peptide probe requires dual (reductive and proteolytic) cleavages on both disulfide and amide bond of iRGD peptide. Furthermore, the cleavage of the iRGD peptide leading to fluorescence recovery was indeed operative depending on the tumor-related angiogenic receptors (αvβ3 integrin and neuropilin-1) in vitro as well as in vivo. Compared to an 'always fluorescent' iRGD control probe without quencher conjugation, the dye/quencher-conjugated activatable monolithic peptide probe visualized tumor regions more precisely with lower background noise after intravenous injection, owing to the multifunctional responses specific to tumor microenvironment. All these results, along with minimal in vitro and in vivo toxicity profiles, suggest potential of the iRGD-based activatable monolithic peptide probe as a promising imaging agent for precise tumor diagnosis. Copyright © 2016 Elsevier B.V. All rights reserved.

Phage display biopanning and isolation of target-unrelated peptides: in search of nonspecific binders hidden in a combinatorial library.

PubMed

Bakhshinejad, Babak; Zade, Hesam Motaleb; Shekarabi, Hosna Sadat Zahed; Neman, Sara

2016-12-01

Phage display is known as a powerful methodology for the identification of targeting ligands that specifically bind to a variety of targets. The high-throughput screening of phage display combinatorial peptide libraries is performed through the affinity selection method of biopanning. Although phage display selection has proven very successful in the discovery of numerous high-affinity target-binding peptides with potential application in drug discovery and delivery, the enrichment of false-positive target-unrelated peptides (TUPs) without any actual affinity towards the target remains a major problem of library screening. Selection-related TUPs may emerge because of binding to the components of the screening system rather than the target. Propagation-related TUPs may arise as a result of faster growth rate of some phage clones enabling them to outcompete slow-propagating clones. Amplification of the library between rounds of biopanning makes a significant contribution to the selection of phage clones with propagation advantage. Distinguishing nonspecific TUPs from true target binders is of particular importance for the translation of biopanning findings from basic research to clinical applications. Different experimental and in silico approaches are applied to assess the specificity of phage display-derived peptides towards the target. Bioinformatic tools are playing a rapidly growing role in the analysis of biopanning data and identification of target-irrelevant TUPs. Recent progress in the introduction of efficient strategies for TUP detection holds enormous promise for the discovery of clinically relevant cell- and tissue-homing peptides and paves the way for the development of novel targeted diagnostic and therapeutic platforms in pharmaceutical areas.

α/β-Peptide Foldamers Targeting Intracellular Protein-Protein Interactions with Activity in Living Cells.

PubMed

Checco, James W; Lee, Erinna F; Evangelista, Marco; Sleebs, Nerida J; Rogers, Kelly; Pettikiriarachchi, Anne; Kershaw, Nadia J; Eddinger, Geoffrey A; Belair, David G; Wilson, Julia L; Eller, Chelcie H; Raines, Ronald T; Murphy, William L; Smith, Brian J; Gellman, Samuel H; Fairlie, W Douglas

2015-09-09

Peptides can be developed as effective antagonists of protein-protein interactions, but conventional peptides (i.e., oligomers of l-α-amino acids) suffer from significant limitations in vivo. Short half-lives due to rapid proteolytic degradation and an inability to cross cell membranes often preclude biological applications of peptides. Oligomers that contain both α- and β-amino acid residues ("α/β-peptides") manifest decreased susceptibility to proteolytic degradation, and when properly designed these unnatural oligomers can mimic the protein-recognition properties of analogous "α-peptides". This report documents an extension of the α/β-peptide approach to target intracellular protein-protein interactions. Specifically, we have generated α/β-peptides based on a "stapled" Bim BH3 α-peptide, which contains a hydrocarbon cross-link to enhance α-helix stability. We show that a stapled α/β-peptide can structurally and functionally mimic the parent stapled α-peptide in its ability to enter certain types of cells and block protein-protein interactions associated with apoptotic signaling. However, the α/β-peptide is nearly 100-fold more resistant to proteolysis than is the parent stapled α-peptide. These results show that backbone modification, a strategy that has received relatively little attention in terms of peptide engineering for biomedical applications, can be combined with more commonly deployed peripheral modifications such as side chain cross-linking to produce synergistic benefits.

Naturally Inspired Peptide Leads: Alanine Scanning Reveals an Actin‐Targeting Thiazole Analogue of Bisebromoamide

PubMed Central

Johnston, Heather J.; Boys, Sarah K.; Makda, Ashraff; Carragher, Neil O.

2016-01-01

Abstract Systematic alanine scanning of the linear peptide bisebromoamide (BBA), isolated from a marine cyanobacterium, was enabled by solid‐phase peptide synthesis of thiazole analogues. The analogues have comparable cytotoxicity (nanomolar) to that of BBA, and cellular morphology assays indicated that they target the actin cytoskeleton. Pathway inhibition in human colon tumour (HCT116) cells was explored by reverse phase protein array (RPPA) analysis, which showed a dose‐dependent response in IRS‐1 expression. Alanine scanning reveals a structural dependence to the cytotoxicity, actin targeting and pathway inhibition, and allows a new readily synthesised lead to be proposed. PMID:27304907

Optimization of brain metabolism using metabolic-targeted therapeutic hypothermia can reduce mortality from traumatic brain injury.

PubMed

Feng, Jin-Zhou; Wang, Wen-Yuan; Zeng, Jun; Zhou, Zhi-Yuan; Peng, Jin; Yang, Hao; Deng, Peng-Chi; Li, Shi-Jun; Lu, Charles D; Jiang, Hua

2017-08-01

Therapeutic hypothermia is widely used to treat traumatic brain injuries (TBIs). However, determining the best hypothermia therapy strategy remains a challenge. We hypothesized that reducing the metabolic rate, rather than reaching a fixed body temperature, would be an appropriate target because optimizing metabolic conditions especially the brain metabolic environment may enhance neurologic protection. A pilot single-blind randomized controlled trial was designed to test this hypothesis, and a nested metabolomics study was conducted to explore the mechanics thereof. Severe TBI patients (Glasgow Coma Scale score, 3-8) were randomly divided into the metabolic-targeted hypothermia treatment (MTHT) group, 50% to 60% rest metabolic ratio as the hypothermia therapy target, and the body temperature-targeted hypothermia treatment (BTHT) control group, hypothermia therapy target of 32°C to 35°C body temperature. Brain and circulatory metabolic pool blood samples were collected at baseline and on days 1, 3, and 7 during the hypothermia treatment, which were selected randomly from a subgroup of MTHT and BTHT groups. The primary outcome was mortality. Using H nuclear magnetic resonance technology, we tracked and located the disturbances of metabolic networks. Eighty-eight severe TBI patients were recruited and analyzed from December 2013 to December 2014, 44 each were assigned in the MTHT and BTHT groups (median age, 42 years; 69.32% men; mean Glasgow Coma Scale score, 6.17 ± 1.02). The mortality was significantly lower in the MTHT than the BTHT group (15.91% vs. 34.09%; p = 0.049). From these, eight cases of MTHT and six cases from BTHT group were enrolled for metabolomics analysis, which showed a significant difference between the brain and circulatory metabolic patterns in MTHT group on day 7 based on the model parameters and scores plots. Finally, metabolites representing potential neuroprotective monitoring parameters for hypothermia treatment were identified through

Evaluation of 111In-Labeled Cyclic RGD Peptides: Effects of Peptide and Linker Multiplicity on Their Tumor Uptake, Excretion Kinetics and Metabolic Stability

PubMed Central

Shi, Jiyun; Zhou, Yang; Chakraborty, Sudipta; Kim, Young-Seung; Jia, Bing; Wang, Fan; Liu, Shuang

2011-01-01

Purpose: The purpose of this study was to demonstrate the valence of cyclic RGD peptides, P-RGD (PEG4-c(RGDfK): PEG4 = 15-amino-4,710,13-tetraoxapentadecanoic acid), P-RGD2 (PEG4-E[c(RGDfK)]2, 2P-RGD4 (E{PEG4-E[c(RGDfK)]2}2, 2P4G-RGD4 (E{PEG4-E[G3-c(RGDfK)]2}2: G3 = Gly-Gly-Gly) and 6P-RGD4 (E{PEG4-E[PEG4-c(RGDfK)]2}2) in binding to integrin αvβ3, and to assess the impact of peptide and linker multiplicity on biodistribution properties, excretion kinetics and metabolic stability of their corresponding 111In radiotracers. Methods: Five new RGD peptide conjugates (DOTA-P-RGD (DOTA =1,4,7,10-tetraazacyclododecane-1,4,7,10-tetracetic acid), DOTA-P-RGD2, DOTA-2P-RGD4, DOTA-2P4G-RGD4, DOTA-6P-RGD4), and their 111In complexes were prepared. The integrin αvβ3 binding affinity of cyclic RGD conjugates were determined by a competitive displacement assay against 125I-c(RGDyK) bound to U87MG human glioma cells. Biodistribution, planar imaging and metabolism studies were performed in athymic nude mice bearing U87MG human glioma xenografts. Results: The integrin αvβ3 binding affinity of RGD conjugates follows the order of: DOTA-6P-RGD4 (IC50 = 0.3 ± 0.1 nM) ~ DOTA-2P4G-RGD4 (IC50 = 0.2 ± 0.1 nM) ~ DOTA-2P-RGD4 (IC50 = 0.5 ± 0.1 nM) > DOTA-3P-RGD2 (DOTA-PEG4-E[PEG4-c(RGDfK)]2: IC50 = 1.5 ± 0.2 nM) > DOTA-P-RGD2 (IC50 = 5.0 ± 1.0 nM) >> DOTA-P-RGD (IC50 = 44.3 ± 3.5 nM) ~ c(RGDfK) (IC50 = 49.9 ± 5.5 nM) >> DOTA-6P-RGK4 (IC50 = 437 ± 35 nM). The fact that DOTA-6P-RGK4 had much lower integrin αvβ3 binding affinity than DOTA-6P-RGD4 suggests that the binding of DOTA-6P-RGD4 to integrin αvβ3 is RGD-specific. This conclusion is consistent with the lower tumor uptake for 111In(DOTA-6P-RGK4) than that for 111In(DOTA-6P-RGD4). It was also found that the G3 and PEG4 linkers between RGD motifs have a significant impact on the integrin αvβ3-targeting capability, biodistribution characteristics, excretion kinetics and metabolic stability of 111In-labeled cyclic RGD

Using iRT, a normalized retention time for more targeted measurement of peptides

PubMed Central

Escher, Claudia; Reiter, Lukas; MacLean, Brendan; Ossola, Reto; Herzog, Franz; Chilton, John; MacCoss, Michael J.; Rinner, Oliver

2014-01-01

Multiple reaction monitoring (MRM) has recently become the method of choice for targeted quantitative measurement of proteins using mass spectrometry. The method, however, is limited in the number of peptides that can be measured in one run. This number can be markedly increased by scheduling the acquisition if the accurate retention time (RT) of each peptide is known. Here we present iRT, an empirically derived dimensionless peptide-specific value that allows for highly accurate RT prediction. The iRT of a peptide is a fixed number relative to a standard set of reference iRT-peptides that can be transferred across laboratories and chromatographic systems. We show that iRT facilitates the setup of multiplexed experiments with acquisition windows more than 4 times smaller compared to in silico RT predictions resulting in improved quantification accuracy. iRTs can be determined by any laboratory and shared transparently. The iRT concept has been implemented in Skyline, the most widely used software for MRM experiments. PMID:22577012

99m Tc-HYNIC-(Ser)3 -J18 peptide: A radiotracer for non-small-cell lung cancer targeting.

PubMed

Shaghaghi, Zahra; Abedi, Seyed Mohammad; Hosseinimehr, Seyed Jalal

2018-02-14

Radiolabeled peptide could be a useful tool for the diagnosis of non-small-cell lung cancer (NSCLC). In this study, HYNIC-(Ser) 3 -J18 peptide was labeled with 99m Tc using EDDA/tricine as coligands. The in vitro and in vivo studies of this radiolabeled peptide were performed for cellular-specific binding and tumor targeting in A-549 cells and tumor-bearing mice, respectively. The high radiochemical purity was obtained and this radiolabeled peptide exhibited high stability in buffer and serum. The radiolabeled peptide showed high affinity for the A-549 cells with a dissociation constant value (K D ) of 4.4 ± 0.8 nm. The tumor-muscles ratios were 2.7 and 4.4 at 1 and 2 hr after injection of 99m Tc-(EDDA/tricine)-HYNIC-(Ser) 3 -J18 in tumor-bearing mice. The tumor uptake was decreased after preinjection with non-labeled peptide for this radiolabeled peptide in blocking experiment. The results of this study showed the 99m Tc-(EDDA/tricine)-(Ser) 3 -HYNIC-J18 peptide might be a promising radiolabeled peptide for NSCLC targeting. © 2018 John Wiley & Sons A/S.

Development of a novel cyclic RGD peptide for multiple targeting approaches of liposomes to tumor region.

PubMed

Amin, Mohamadreza; Mansourian, Mercedeh; Koning, Gerben A; Badiee, Ali; Jaafari, Mahmoud Reza; Ten Hagen, Timo L M

2015-12-28

Liposomes containing cytotoxic agents and targeted with Arg-Gly-Asp based peptides have frequently been used against αvβ3 integrin on tumor neovasculature. However, like many other ligand modified liposomes these preparations suffered from enhanced uptake by the reticulo endothelial system (RES) and off-targeted interaction with integrin receptors vastly expressed in normal organs causing poor biodistribution and toxic effects. Here we mainly focus on development of a RGD-modified liposomal delivery system to enhance both targeting selectivity and tumor uptake. First, sterically stabilized liposomal doxorubicin (SSLD) prepared and decorated with cRGDfK and RGDyC peptides differ in their physical properties. Stability assessments as well as in vitro and in vivo studies revealed that increasing the peptide hydrophobicity promotes the therapeutic efficacy of RGD-SSLD in a C-26 tumor model due to decreased recognition by RES and opsonization and limited off-targeted interactions. Then a novel N-methylated RGD peptide was designed and its capability in targeting integrin presenting cells was comprehensively assessed both in vitro and in vivo. RGDf[N-methyl]C promotes the liposome internalization by HUVEC via integrin mediated endocytosis. Intravital microscopy in window chamber bearing mice illustrated the capability of RGDf[N-methyl]C-liposomes in targeting both tumor vasculature and tumor cells in murine B16F0 and human BLM tumor models. Quantitative biodistribution in mice bearing B16F0 tumor revealed its high affinity to tumor with no considerable affinity to normal organs. Treatment by high dose of RGDf[N-methyl]C-SSLD was found more effective than non-targeted SSLD and no toxic side effect was observed. In conclusion, the RGDf[N-methyl]C-liposome was found promising in targeting tumor vasculature as well as other cells inside the tumor. Copyright © 2015 Elsevier B.V. All rights reserved.

Screening sourdough samples for gliadin-degrading activity revealed Lactobacillus casei strains able to individually metabolize the coeliac-disease-related 33-mer peptide.

PubMed

Alvarez-Sieiro, Patricia; Redruello, Begoña; Ladero, Victor; Martín, Maria Cruz; Fernández, María; Alvarez, Miguel A

2016-05-01

A selective culture medium containing acid-hydrolyzed gliadins as the sole nitrogen source was used in the search for sourdough-indigenous lactic acid bacteria (LAB) with gliadin-metabolizing activity. Twenty gliadin-degrading LAB strains were isolated from 10 sourdoughs made in different ways and from different geographical regions. Fifteen of the 20 isolated strains were identified as Lactobacillus casei, a species usually reported as subdominant in sourdough populations. The other 5 gliadin-degrading strains belonged to the more commonly encountered sourdough species Leuconostoc mesenteroides and Lactobacillus plantarum. All these strains were shown to be safe in terms of their resistance to antimicrobial agents. When individually incubated with the α2-gliadin-derived immunotoxic 33-mer peptide (97.5 ppm), half of the L. casei strains metabolized at least 50% of it within 24 h. One strain metabolized 82% of the 33-mer peptide within 8 h and made it fully disappear within 12 h. These results reveal for the first time the presence in sourdough of proteolytic L. casei strains with the capacity to individually metabolize the coeliac-disease-related 33-mer peptide.

Blueprint for antimicrobial hit discovery targeting metabolic networks.

PubMed

Shen, Y; Liu, J; Estiu, G; Isin, B; Ahn, Y-Y; Lee, D-S; Barabási, A-L; Kapatral, V; Wiest, O; Oltvai, Z N

2010-01-19

Advances in genome analysis, network biology, and computational chemistry have the potential to revolutionize drug discovery by combining system-level identification of drug targets with the atomistic modeling of small molecules capable of modulating their activity. To demonstrate the effectiveness of such a discovery pipeline, we deduced common antibiotic targets in Escherichia coli and Staphylococcus aureus by identifying shared tissue-specific or uniformly essential metabolic reactions in their metabolic networks. We then predicted through virtual screening dozens of potential inhibitors for several enzymes of these reactions and showed experimentally that a subset of these inhibited both enzyme activities in vitro and bacterial cell viability. This blueprint is applicable for any sequenced organism with high-quality metabolic reconstruction and suggests a general strategy for strain-specific antiinfective therapy.

α/β-Peptide Foldamers Targeting Intracellular Protein-Protein Interactions with Activity in Living Cells

PubMed Central

Checco, James W.; Lee, Erinna F.; Evangelista, Marco; Sleebs, Nerida J.; Rogers, Kelly; Pettikiriarachchi, Anne; Kershaw, Nadia J.; Eddinger, Geoffrey A.; Belair, David G.; Wilson, Julia L.; Eller, Chelcie H.; Raines, Ronald T.; Murphy, William L.; Smith, Brian J.; Gellman, Samuel H.; Fairlie, W. Douglas

2015-01-01

Peptides can be developed as effective antagonists of protein-protein interactions, but conventional peptides (i.e., oligomers of L-α-amino acids) suffer from significant limitations in vivo. Short half-lives due to rapid proteolytic degradation and an inability to cross cell membranes often preclude biological applications of peptides. Oligomers that contain both α- and β-amino acid residues (“α/β-peptides”) manifest decreased susceptibility to proteolytic degradation, and when properly designed these unnatural oligomers can mimic the protein-recognition properties of analogous “α-peptides”. This report documents an extension of the α/β-peptide approach to target intracellular protein-protein interactions. Specifically, we have generated α/β-peptides based on a “stapled” Bim BH3 α-peptide, which contains a hydrocarbon crosslink to enhance α-helix stability. We show that a stapled α/β-peptide can structurally and functionally mimic the parent stapled α-peptide in its ability to enter certain types of cells and block protein-protein interactions associated with apoptotic signaling. However, the α/β-peptide is nearly 100-fold more resistant to proteolysis than is the parent α-peptide. These results show that backbone modification, a strategy that has received relatively little attention in terms of peptide engineering for biomedical applications, can be combined with more commonly deployed peripheral modifications such as side chain crosslinking to produce synergistic benefits. PMID:26317395

Soluble elastin peptides in cardiovascular homeostasis: Foe or ally.

PubMed

Qin, Zhenyu

2015-05-01

Elastin peptides, also known as elastin-derived peptides or elastokines, are soluble polypeptides in blood and tissue. The blood levels of elastin peptides are usually low but can increase during cardiovascular diseases, such as atherosclerosis, aortic aneurysm and diabetes with vascular complications. Generally, elastin peptides are derived from the degradation of insoluble elastic polymers. The biological activities of elastin peptides are bidirectional, e.g., a pro-inflammatory effect on monocyte migration induction vs. a protective effect on vasodilation promotion. However, recent in vivo studies have demonstrated that elastin peptides promote the formation of atherosclerotic plaques in hypercholesterolemic mice and induce hyperglycemia and elevations in plasma lipid levels in fasted mice. More important, the detrimental effects induced by elastin peptides can be largely inhibited by genetic or pharmacological blockade of the elastin receptor complex or by neutralization of an antibody against elastin peptides. These studies indicate new therapeutic strategies for the treatment of cardiovascular diseases by targeting elastin peptide metabolism. Therefore, the goal of this review is to summarize current knowledge about elastin peptides relevant to cardiovascular pathologies to further delineate their potential application in cardiovascular disease. Copyright © 2015 Elsevier Inc. All rights reserved.

Fibrin-binding, peptide amphiphile micelles for targeting glioblastoma☆

PubMed Central

Chung, Eun Ji; Cheng, Yu; Morshed, Ramin; Nord, Kathryn; Han, Yu; Wegscheid, Michelle L.; Auffinger, Brenda; Wainwright, Derek A.; Lesniak, Maciej S.; Tirrell, Matthew V.

2013-01-01

Glioblastoma-targeted drug delivery systems facilitate efficient delivery of chemotherapeutic agents to malignant gliomas, while minimizing systemic toxicity and side effects. Taking advantage of the fibrin deposition that is characteristic of tumors, we constructed spherical, Cy7-labeled, targeting micelles to glioblastoma through the addition of the fibrin-binding pentapeptide, cysteine–arginine–glutamic acid–lysine–alanine, or CREKA. Conjugation of the CREKA peptide to Cy7-micelles increased the average particle size and zeta potential. Upon intravenous administration to GL261 glioma bearing mice, Cy7-micelles passively accumulated at the brain tumor site via the enhanced permeability and retention (EPR) effect, and Cy7-CREKA-micelles displayed enhanced tumor homing via active targeting as early as 1 h after administration, as confirmed via in vivo and ex vivo imaging and immunohistochemistry. Biodistribution of micelles showed an accumulation within the liver and kidneys, leading to micelle elimination via renal clearance and the reticuloendothelial system (RES). Histological evaluation showed no signs of cytotoxicity or tissue damage, confirming the safety and utility of this nanoparticle system for delivery to glioblastoma. Our findings offer strong evidence for the glioblastoma-targeting potential of CREKA-micelles and provide the foundation for CREKA-mediated, targeted therapy of glioma. PMID:24211079

RGD Peptide Cell-Surface Display Enhances the Targeting and Therapeutic Efficacy of Attenuated Salmonella-mediated Cancer Therapy.

PubMed

Park, Seung-Hwan; Zheng, Jin Hai; Nguyen, Vu Hong; Jiang, Sheng-Nan; Kim, Dong-Yeon; Szardenings, Michael; Min, Jung Hyun; Hong, Yeongjin; Choy, Hyon E; Min, Jung-Joon

2016-01-01

Bacteria-based anticancer therapies aim to overcome the limitations of current cancer therapy by actively targeting and efficiently removing cancer. To achieve this goal, new approaches that target and maintain bacterial drugs at sufficient concentrations during the therapeutic window are essential. Here, we examined the tumor tropism of attenuated Salmonella typhimurium displaying the RGD peptide sequence (ACDCRGDCFCG) on the external loop of outer membrane protein A (OmpA). RGD-displaying Salmonella strongly bound to cancer cells overexpressing αvβ3, but weakly bound to αvβ3-negative cancer cells, suggesting the feasibility of displaying a preferential homing peptide on the bacterial surface. In vivo studies revealed that RGD-displaying Salmonellae showed strong targeting efficiency, resulting in the regression in αvβ3-overexpressing cancer xenografts, and prolonged survival of mouse models of human breast cancer (MDA-MB-231) and human melanoma (MDA-MB-435). Thus, surface engineering of Salmonellae to display RGD peptides increases both their targeting efficiency and therapeutic effect.

Peptide targeting of quantum dots to human breast cancer cells

NASA Astrophysics Data System (ADS)

Haglund, Emily M.; Seale-Goldsmith, Mary-Margaret; Dhawan, Deepika; Stewart, Jane; Ramos-Vara, Jose; Cooper, Christy L.; Reece, Lisa M.; Husk, Timothy; Bergstrom, Donald; Knapp, Deborah; Leary, James F.

2008-02-01

Nanomedical approaches to diseases such as cancer provide great promise with respect to diagnostic and therapeutic applications. The impact of nanomedicine versus conventional therapies will be realized with regard to their specific cell targeting capabilities. Semiconductor nanoparticles have distinct advantages due to their chemical conjugation and detection characteristics. The attachment of a peptide sequence, LTVSPWY, was completed. These nanoparticles successfully targeted in vitro and in vivo systems. This technology can be utilized as a base mechanism for the construction of a multifunctional nanomedical system. Nanomedicine has great potential for impacting the treatment of specific diseases and healthcare delivery methods.

Bombesin related peptides/receptors and their promising therapeutic roles in cancer imaging, targeting and treatment

PubMed Central

Moreno, Paola; Ramos-Álvarez, Irene; Moody, Terry W.; Jensen, Robert T.

2016-01-01

Introduction Despite remarkable advances in tumor treatment, many patients still die from common tumors (breast, prostate, lung, CNS, colon, and pancreas), and thus, new approaches are needed. Many of these tumors synthesize bombesin (Bn)-related peptides and over-express their receptors (BnRs), hence functioning as autocrine-growth-factors. Recent studies support the conclusion that Bn-peptides/BnRs are well-positioned for numerous novel antitumor treatments, including interrupting autocrine-growth via the use of over-expressed receptors for imaging and targeting cytotoxic-compounds, either by direct-coupling or combined with nanoparticle-technology. Areas covered The unique ability of common neoplasms to synthesize, secrete, and show a growth/proliferative/differentiating response due to BnR over-expression, is reviewed, both in general and with regard to the most frequently investigated neoplasms (breast, prostate, lung, and CNS). Particular attention is paid to advances in the recent years. Also considered are the possible therapeutic approaches to the growth/differentiation effect of Bn-peptides, as well as the therapeutic implication of the frequent BnR over-expression for tumor-imaging and/or targeted-delivery. Expert opinion Given that Bn-related-peptides/BnRs are so frequently ectopically-expressed by common tumors, which are often malignant and become refractory to conventional treatments, therapeutic interventions using novel approaches to Bn-peptides and receptors are being explored. Of particular interest is the potential of reproducing BnRs in common tumors, such as the recent success of utilizing overexpression of somatostatin-receptors by neuroendocrine-tumors to provide the most sensitive imaging methods and targeted delivery of cytotoxic-compounds. PMID:26981612

Using PeptideAtlas, SRMAtlas and PASSEL – Comprehensive Resources for discovery and targeted proteomics

PubMed Central

Kusebauch, Ulrike; Deutsch, Eric W.; Campbell, David S.; Sun, Zhi; Farrah, Terry; Moritz, Robert L.

2014-01-01

PeptideAtlas, SRMAtlas and PASSEL are web-accessible resources to support discovery and targeted proteomics research. PeptideAtlas is a multi-species compendium of shotgun proteomic data provided by the scientific community, SRMAtlas is a resource of high-quality, complete proteome SRM assays generated in a consistent manner for the targeted identification and quantification of proteins, and PASSEL is a repository that compiles and represents selected reaction monitoring data, all in an easy to use interface. The databases are generated from native mass spectrometry data files that are analyzed in a standardized manner including statistical validation of the results. Each resource offers search functionalities and can be queried by user defined constraints; the query results are provided in tables or are graphically displayed. PeptideAtlas, SRMAtlas and PASSEL are publicly available freely via the website http://www.peptideatlas.org. In this protocol, we describe the use of these resources, we highlight how to submit, search, collate and download data. PMID:24939129

Targeted separation of antibacterial peptide from protein hydrolysate of anchovy cooking wastewater by equilibrium dialysis.

PubMed

Tang, Wenting; Zhang, Hui; Wang, Li; Qian, Haifeng; Qi, Xiguang

2015-02-01

Anchovy (Engraulis japonicus) cooking wastewater (ACWW) is a by-product resulted from the production of boiled-dried anchovies in the seafood processing industry. In this study, the protein hydrolysate of ACWW (ACWWPH) was found to have antimicrobial activity after enzymatic hydrolysis with Protamex. For the targeted screening of antibacterial peptides, liposomes constructed from Staphylococcus aureus membrane lipids were used in an equilibrium dialysis system. The hydrolysate was further purified by liposome equilibrium dialysis combined with high performance liquid chromatography. The purified antimicrobial peptide (ACWWP1) was determined to be GLSRLFTALK, with a molecular weight of 1104.6622Da. The peptide exhibited no haemolytic activity up to a concentration of 512μg/ml. It displayed a dose-dependent bactericidal effect in reconstituted milk. The change in cell surface hydrophobicity and membrane-permeable action of the purified ACWWP1 may have contributed to the antibacterial effect. This study suggests that liposome equilibrium dialysis can be used for the targeted screening of antimicrobial peptides. Copyright © 2014 Elsevier Ltd. All rights reserved.

Blueprint for antimicrobial hit discovery targeting metabolic networks

PubMed Central

Shen, Y.; Liu, J.; Estiu, G.; Isin, B.; Ahn, Y-Y.; Lee, D-S.; Barabási, A-L.; Kapatral, V.; Wiest, O.; Oltvai, Z. N.

2010-01-01

Advances in genome analysis, network biology, and computational chemistry have the potential to revolutionize drug discovery by combining system-level identification of drug targets with the atomistic modeling of small molecules capable of modulating their activity. To demonstrate the effectiveness of such a discovery pipeline, we deduced common antibiotic targets in Escherichia coli and Staphylococcus aureus by identifying shared tissue-specific or uniformly essential metabolic reactions in their metabolic networks. We then predicted through virtual screening dozens of potential inhibitors for several enzymes of these reactions and showed experimentally that a subset of these inhibited both enzyme activities in vitro and bacterial cell viability. This blueprint is applicable for any sequenced organism with high-quality metabolic reconstruction and suggests a general strategy for strain-specific antiinfective therapy. PMID:20080587

New Targets and Inhibitors of Mycobacterial Sulfur Metabolism§

PubMed Central

Paritala, Hanumantharao; Carroll, Kate S.

2015-01-01

The identification of new antibacterial targets is urgently needed to address multidrug resistant and latent tuberculosis infection. Sulfur metabolic pathways are essential for survival and the expression of virulence in many pathogenic bacteria, including Mycobacterium tuberculosis. In addition, microbial sulfur metabolic pathways are largely absent in humans and therefore, represent unique targets for therapeutic intervention. In this review, we summarize our current understanding of the enzymes associated with the production of sulfated and reduced sulfur-containing metabolites in Mycobacteria. Small molecule inhibitors of these catalysts represent valuable chemical tools that can be used to investigate the role of sulfur metabolism throughout the Mycobacterial lifecycle and may also represent new leads for drug development. In this light, we also summarize recent progress made in the development of inhibitors of sulfur metabolism enzymes. PMID:23808874

Metabolism as a Target for Modulation in Autoimmune Diseases.

PubMed

Huang, Nick; Perl, Andras

2018-05-05

Metabolic pathways are now well recognized as important regulators of immune differentiation and activation, and thus influence the development of autoimmune diseases such as systemic lupus erythematosus (SLE). The mechanistic target of rapamycin (mTOR) has emerged as a key sensor of metabolic stress and an important mediator of proinflammatory lineage specification. Metabolic pathways control the production of mitochondrial reactive oxygen species (ROS), which promote mTOR activation and also modulate the antigenicity of proteins, lipids, and DNA, thus placing ROS at the heart of metabolic disturbances during pathogenesis of SLE. Therefore, we review here the pathways that control ROS production and mTOR activation and identify targets for safe therapeutic modulation of the signaling network that underlies autoimmune diseases, focusing on SLE. Copyright © 2018. Published by Elsevier Ltd.

Novel fluorescent contrast agents for optical imaging of in vivo tumors based on a receptor-targeted dye-peptide conjugate platform

NASA Astrophysics Data System (ADS)

Bugaj, Joseph E.; Achilefu, Samuel I.; Dorshow, Richard B.; Rajagopalan, Raghavan

2001-04-01

We have designed, synthesized, and evaluated the efficacy of novel dye-peptide conjugates that are receptor specific. Contrary to the traditional approach of conjugating dyes to large proteins and antibodies, we used small peptide-dye conjugates that target over-expressed receptors on tumors. Despite the fact that the peptide and the dye probe have similar molecular mass, our results demonstrate that the affinity of the peptide for its receptor and the dye fluorescence properties are both retained. The use of small peptides has several advantages over large biomolecules, including ease of synthesis of a variety of compounds for potential combinatorial screening of new targets, reproducibility of high purity compounds, diffusiveness to solid tumors, and the ability to incorporate a variety of functional groups that modify the pharmacokinetics of the peptide-dye conjugates. The efficacy of these new fluorescent optical contrast agents was evaluated in vivo in well-characterized rat tumor lines expressing somatostatin (sst2) and bombesin receptors. A simple continuous wave optical imaging system was employed. The resulting optical images clearly show that successful specific tumor targeting was achieved. Thus, we have demonstrated that small peptide- dye conjugates are effective as contrast agents for optical imaging of tumors.

Using iRT, a normalized retention time for more targeted measurement of peptides.

PubMed

Escher, Claudia; Reiter, Lukas; MacLean, Brendan; Ossola, Reto; Herzog, Franz; Chilton, John; MacCoss, Michael J; Rinner, Oliver

2012-04-01

Multiple reaction monitoring (MRM) has recently become the method of choice for targeted quantitative measurement of proteins using mass spectrometry. The method, however, is limited in the number of peptides that can be measured in one run. This number can be markedly increased by scheduling the acquisition if the accurate retention time (RT) of each peptide is known. Here we present iRT, an empirically derived dimensionless peptide-specific value that allows for highly accurate RT prediction. The iRT of a peptide is a fixed number relative to a standard set of reference iRT-peptides that can be transferred across laboratories and chromatographic systems. We show that iRT facilitates the setup of multiplexed experiments with acquisition windows more than four times smaller compared to in silico RT predictions resulting in improved quantification accuracy. iRTs can be determined by any laboratory and shared transparently. The iRT concept has been implemented in Skyline, the most widely used software for MRM experiments. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Exploiting cancer’s phenotypic guise against itself: targeting ectopically expressed peptide G-protein coupled receptors for lung cancer therapy

PubMed Central

Khan, Mahjabin; Huang, Tao; Lin, Cheng-Yuan; Wu, Jiang; Fan, Bao-Min; Bian, Zhao-Xiang

2017-01-01

Lung cancer, claiming millions of lives annually, has the highest mortality rate worldwide. This advocates the development of novel cancer therapies that are highly toxic for cancer cells but negligibly toxic for healthy cells. One of the effective treatments is targeting overexpressed surface receptors of cancer cells with receptor-specific drugs. The receptors-in-focus in the current review are the G-protein coupled receptors (GPCRs), which are often overexpressed in various types of tumors. The peptide subfamily of GPCRs is the pivot of the current article owing to the high affinity and specificity to and of their cognate peptide ligands, and the proven efficacy of peptide-based therapeutics. The article summarizes various ectopically expressed peptide GPCRs in lung cancer, namely, Cholecystokinin-B/Gastrin receptor, the Bombesin receptor family, Bradykinin B1 and B2 receptors, Arginine vasopressin receptors 1a, 1b and 2, and the Somatostatin receptor type 2. The autocrine growth and pro-proliferative pathways they mediate, and the distinct tumor-inhibitory effects of somatostatin receptors are then discussed. The next section covers how these pathways may be influenced or ‘corrected’ through therapeutics (involving agonists and antagonists) targeting the overexpressed peptide GPCRs. The review proceeds on to Nano-scaled delivery platforms, which enclose chemotherapeutic agents and are decorated with peptide ligands on their external surface, as an effective means of targeting cancer cells. We conclude that targeting these overexpressed peptide GPCRs is potentially evolving as a highly promising form of lung cancer therapy. PMID:29262666

A new molecular targeted therapeutic approach for renal cell carcinoma with a p16 functional peptide using a novel transporter system.

PubMed

Zennami, Kenji; Yoshikawa, Kazuhiro; Kondo, Eisaku; Nakamura, Kogenta; Upsilonamada, Yoshiaki; De Velasco, Marco A; Tanaka, Motoyoshi; Uemura, Hirotsugu; Shimazui, Toru; Akaza, Hideyuki; Saga, Shinsuke; Ueda, Ryuzo; Honda, Nobuaki

2011-08-01

Molecular targeting agents have become formidable anticancer weapons showing much promise against refractory tumors and functional peptides and are among the more desirable of these nanobio-tools. Intracellular delivery of multiple functional peptides forms the basis for a potent, non-invasive mode of delivery, providing distinctive therapeutic advantages. We examine the growth suppression efficiency of human renal cell carcinoma (RCC) by single-peptide targeting. We simultaneously introduced p16INK4a tumor suppressor peptides by Wr-T-mediated peptide delivery. Wr-T-mediated transport of p16INK4a functional peptide into 10 RCC lines, lacking expression of the p16INK4a molecule, reversed the specific loss of p16 function, thereby drastically inhibiting tumor growth in all but 3 lines by >95% within the first 96 h. In vivo analysis using SK-RC-7 RCC xenografts in nude mice demonstrated tumor growth inhibition by the p16INK4a peptide alone, however, inoculation of Wr-T and the p16INK4a functional peptide mixture, via the heart resulted in complete tumor regression. Thus, restoration of tumor suppressor function with Wr-T peptide delivery represents a powerful approach, with mechanistic implications for the development of efficacious molecular targeting therapeutics against intractable RCC.

Selective detection of target proteins by peptide-enabled graphene biosensor.

PubMed

Khatayevich, Dmitriy; Page, Tamon; Gresswell, Carolyn; Hayamizu, Yuhei; Grady, William; Sarikaya, Mehmet

2014-04-24

Direct molecular detection of biomarkers is a promising approach for diagnosis and monitoring of numerous diseases, as well as a cornerstone of modern molecular medicine and drug discovery. Currently, clinical applications of biomarkers are limited by the sensitivity, complexity and low selectivity of available indirect detection methods. Electronic 1D and 2D nano-materials such as carbon nanotubes and graphene, respectively, offer unique advantages as sensing substrates for simple, fast and ultrasensitive detection of biomolecular binding. Versatile methods, however, have yet to be developed for simultaneous functionalization and passivation of the sensor surface to allow for enhanced detection and selectivity of the device. Herein, we demonstrate selective detection of a model protein against a background of serum protein using a graphene sensor functionalized via self-assembling multifunctional short peptides. The two peptides are engineered to bind to graphene and undergo co-assembly in the form of an ordered monomolecular film on the substrate. While the probe peptide displays the bioactive molecule, the passivating peptide prevents non-specific protein adsorption onto the device surface, ensuring target selectivity. In particular, we demonstrate a graphene field effect transistor (gFET) biosensor which can detect streptavidin against a background of serum bovine albumin at less than 50 ng/ml. Our nano-sensor design, allows us to restore the graphene surface and utilize each sensor in multiple experiments. The peptide-enabled gFET device has great potential to address a variety of bio-sensing problems, such as studying ligand-receptor interactions, or detection of biomarkers in a clinical setting. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Targeting Photoinduced DNA Destruction by Ru(II) Tetraazaphenanthrene in Live Cells by Signal Peptide.

PubMed

Burke, Christopher S; Byrne, Aisling; Keyes, Tia E

2018-06-06

Exploiting NF-κB transcription factor peptide conjugation, a Ru(II)-bis-tap complex (tap = 1,4,5,8-tetraazaphenanthrene) was targeted specifically to the nuclei of live HeLa and CHO cells for the first time. DNA binding of the complex  within the nucleus of live cells was evident from gradual extinction of the metal complex luminescence after it had crossed the nuclear envelope, attributed to guanine quenching of the ruthenium emission via photoinduced electron transfer. Resonance Raman imaging confirmed that the complex remained in the nucleus after emission is extinguished. In the dark and under imaging conditions the cells remain viable, but efficient cellular destruction was induced with precise spatiotemporal control by applying higher irradiation intensities to selected cells. Solution studies indicate that the peptide conjugated complex associates strongly with calf thymus DNA ex-cellulo and gel electrophoresis confirmed that the peptide conjugate is capable of singlet oxygen independent photodamage to plasmid DNA. This indicates that the observed efficient cellular destruction likely operates via direct DNA oxidation by photoinduced electron transfer between guanine and the precision targeted Ru(II)-tap probe. The discrete targeting of polyazaaromatic complexes to the cell nucleus and confirmation that they are photocytotoxic after nuclear delivery is an important step toward their application in cellular phototherapy.

Stapled peptide inhibitors of RAB25 target context-specific phenotypes in cancer | Office of Cancer Genomics

Cancer.gov

Recent evidence has established a role for the small GTPase RAB25, as well as related effector proteins, in enacting both pro-oncogenic and anti-oncogenic phenotypes in specific cellular contexts. Here we report the development of all-hydrocarbon stabilized peptides derived from the RAB-binding FIP-family of proteins to target RAB25. Relative to unmodified peptides, optimized stapled peptides exhibit increased structural stability, binding affinity, cell permeability, and inhibition of RAB25:FIP complex formation.

Carboxypeptidase-mediated metabolism of calcitonin gene-related peptide in human gingival crevicular fluid--a rôle in periodontal inflammation?

PubMed

Lundy, F T; Salmon, A L; Lamey, P J; Shaw, C; Linden, G J

2000-07-01

Metabolism by peptidases plays an important rôle in modulating the levels of biologically-active neuropeptides. The metabolism of the anti-inflammatory neuropeptide calcitonin gene-related peptide (GCRP), but not the pro-inflammatory neuropeptides substance P (SP) and neurokinin A (NKA) by components of the gingival crevicular fluid (GCF), could potentiate the inflammatory process in periodontitis. To characterise the extracellular hydrolysis of CGRP as a mechanism for the selective inactivation of this neuropeptide in GCF from periodontitis sites. Samples of GCF from periodontitis patients and periodontally-healthy subjects were incubated with synthetic human SP, NKA or CGRP. Reaction between the GCF constituents and synthetic peptides was allowed to progress from 0-180 min. Results of neuropeptide metabolism at each time were analysed by matrix-assisted laser desorption/ionisation mass spectrometry. There was no evidence of metabolism of SP, NKA or CGRP by constituents of healthy GCF. Metabolism of synthetic SP and NKA was minimal even after extensive incubation with periodontitis GCF. However, loss of carboxy-terminal amino acids was evident after only 1 min incubation with periodontitis GCF. The pattern of CGRP metabolism, which proceeded from the C-terminus, indicated that the neuropeptide was degraded by a carboxypeptidase. After 180 min, there was extensive carboxypeptidase degradation of CGRP to an 11 amino acid peptide. It is concluded that carboxypeptidase activity in GCF from periodontitis patients is responsible for rapid breakdown of CGRP but not SP or NKA. The rapid action of this carboxypeptidase on the anti-inflammatory neuropeptide CGRP is suggestive of a pathophysiological rôle for the enzyme in selectively degrading CGRP, thereby potentiating periodontal inflammation.

Peptide- and saccharide-conjugated dendrimers for targeted drug delivery: a concise review

PubMed Central

Liu, Jie; Gray, Warren D.; Davis, Michael E.; Luo, Ying

2012-01-01

Dendrimers comprise a category of branched materials with diverse functions that can be constructed with defined architectural and chemical structures. When decorated with bioactive ligands made of peptides and saccharides through peripheral chemical groups, dendrimer conjugates are turned into nanomaterials possessing attractive binding properties with the cognate receptors. At the cellular level, bioactive dendrimer conjugates can interact with cells with avidity and selectivity, and this function has particularly stimulated interests in investigating the targeting potential of dendrimer materials for the design of drug delivery systems. In addition, bioactive dendrimer conjugates have so far been studied for their versatile capabilities to enhance stability, solubility and absorption of various types of therapeutics. This review presents a brief discussion on three aspects of the recent studies to use peptide- and saccharide-conjugated dendrimers for drug delivery: (i) synthesis methods, (ii) cell- and tissue-targeting properties and (iii) applications of conjugated dendrimers in drug delivery nanodevices. With more studies to elucidate the structure–function relationship of ligand–dendrimer conjugates in transporting drugs, the conjugated dendrimers hold promise to facilitate targeted delivery and improve drug efficacy for discovery and development of modern pharmaceutics. PMID:23741608

Fibrin-binding, peptide amphiphile micelles for targeting glioblastoma.

PubMed

Chung, Eun Ji; Cheng, Yu; Morshed, Ramin; Nord, Kathryn; Han, Yu; Wegscheid, Michelle L; Auffinger, Brenda; Wainwright, Derek A; Lesniak, Maciej S; Tirrell, Matthew V

2014-01-01

Glioblastoma-targeted drug delivery systems facilitate efficient delivery of chemotherapeutic agents to malignant gliomas, while minimizing systemic toxicity and side effects. Taking advantage of the fibrin deposition that is characteristic of tumors, we constructed spherical, Cy7-labeled, targeting micelles to glioblastoma through the addition of the fibrin-binding pentapeptide, cysteine-arginine-glutamic acid-lysine-alanine, or CREKA. Conjugation of the CREKA peptide to Cy7-micelles increased the average particle size and zeta potential. Upon intravenous administration to GL261 glioma bearing mice, Cy7-micelles passively accumulated at the brain tumor site via the enhanced permeability and retention (EPR) effect, and Cy7-CREKA-micelles displayed enhanced tumor homing via active targeting as early as 1 h after administration, as confirmed via in vivo and ex vivo imaging and immunohistochemistry. Biodistribution of micelles showed an accumulation within the liver and kidneys, leading to micelle elimination via renal clearance and the reticuloendothelial system (RES). Histological evaluation showed no signs of cytotoxicity or tissue damage, confirming the safety and utility of this nanoparticle system for delivery to glioblastoma. Our findings offer strong evidence for the glioblastoma-targeting potential of CREKA-micelles and provide the foundation for CREKA-mediated, targeted therapy of glioma. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

A Cocoa Peptide Protects Caenorhabditis elegans from Oxidative Stress and β-Amyloid Peptide Toxicity

PubMed Central

Martorell, Patricia; Bataller, Esther; Llopis, Silvia; Gonzalez, Núria; Álvarez, Beatriz; Montón, Fernando; Ortiz, Pepa; Ramón, Daniel; Genovés, Salvador

2013-01-01

Background Cocoa and cocoa-based products contain different compounds with beneficial properties for human health. Polyphenols are the most frequently studied, and display antioxidant properties. Moreover, protein content is a very interesting source of antioxidant bioactive peptides, which can be used therapeutically for the prevention of age-related diseases. Methodology/Principal Findings A bioactive peptide, 13L (DNYDNSAGKWWVT), was obtained from a hydrolyzed cocoa by-product by chromatography. The in vitro inhibition of prolyl endopeptidase (PEP) was used as screening method to select the suitable fraction for peptide identification. Functional analysis of 13L peptide was achieved using the transgenic Caenorhabditis elegans strain CL4176 expressing the human Aβ1–42 peptide as a pre-clinical in vivo model for Alzheimer's disease. Among the peptides isolated, peptide 13L (1 µg/mL) showed the highest antioxidant activity (P≤0.001) in the wild-type strain (N2). Furthermore, 13L produced a significant delay in body paralysis in strain CL4176, especially in the 24–47 h period after Aβ1–42 peptide induction (P≤0.0001). This observation is in accordance with the reduction of Aβ deposits in CL4176 by western blot. Finally, transcriptomic analysis in wild-type nematodes treated with 13L revealed modulation of the proteosomal and synaptic functions as the main metabolic targets of the peptide. Conclusions/Significance These findings suggest that the cocoa 13L peptide has antioxidant activity and may reduce Aβ deposition in a C. elegans model of Alzheimer's disease; and therefore has a putative therapeutic potential for prevention of age-related diseases. Further studies in murine models and humans will be essential to analyze the effectiveness of the 13L peptide in higher animals. PMID:23675471

Targeted radionuclide therapy for lung cancer with iodine-131-labeled peptide in a nude-mouse model.

PubMed

Chen, Zhenzhu; Gao, Hongyi; Li, Man; Fang, Shun; Li, Guiping; Guo, Linlang

2017-06-01

Integrin α3β1 has been shown to be a novel candidate target for the imaging and specific therapy of non-small-cell lung cancer. We have previously reported on a peptide containing a novel motif of NGXG that specifically binds to the integrin α3 receptor on lung cancer cells using a one-bead one-peptide combinatorial library. In this study, we developed the peptide cNGEGQQc-based therapeutic agent labeling with radionuclide iodine-131 (I) and evaluated its characteristics including stability, biodistribution, antitumor activity, and safety. The results showed that I-cNGEGQQc was stable in serum. Furthermore, the biodistribution of I-cNGEGQQc was determined in normal mice and rabbits. In-vivo biodistribution studies showed that radiolabeled peptide in the kidney was significantly higher than that in other organs. Nude mice bearing lung cancer cell xenografts (H1975 and L78) were used as an in-vivo model for tumor-inhibition efficacy studies with I-cNGEGQQc. The tumor growth decreased significantly in mice receiving I-labeled peptide compared with the controls and the effect of I-labeled peptide can be blocked by unlabeled cNGEGQQc. Safety studies showed that I-cNGEGQQc was relatively safe for animals without significant toxicity. Our data suggest that I-cNGEGQQc has potential as a targeted radiotherapeutic agent for non-small-cell lung cancer.

Therapeutic targeting of cancer cell metabolism

PubMed Central

Hamaker, Max; Sun, Peng; Le, Anne; Gao, Ping

2012-01-01

In 1927, Otto Warburg and coworkers reported the increased uptake of glucose and production of lactate by tumors in vivo as compared with normal tissues. This phenomenon, now known as the Warburg effect, was recapitulated in vitro with cancer tissue slices exhibiting excessive lactate production even with adequate oxygen. Warburg's in vivo studies of tumors further suggest that the dependency of tumors in vivo on glucose could be exploited for therapy, because reduction of arterial glucose by half resulted in a four-fold reduction in tumor fermentation. Recent work in cancer metabolism indicates that the Warburg effect or aerobic glycolysis contributes to redox balance and lipid synthesis, but glycolysis is insufficient to sustain a growing and dividing cancer cell. In this regard, glutamine, which contributes its carbons to the tricarboxylic acid (TCA) cycle, has been re-discovered as an essential bioenergetic and anabolic substrate for many cancer cell types. Could alterations in cancer metabolism be exploited for therapy? Here, we address this question by reviewing current concepts of normal metabolism and altered metabolism in cancer cells with specific emphasis on molecular targets involved directly in glycolysis or glutamine metabolism. PMID:21301795

Predicting selective drug targets in cancer through metabolic networks

PubMed Central

Folger, Ori; Jerby, Livnat; Frezza, Christian; Gottlieb, Eyal; Ruppin, Eytan; Shlomi, Tomer

2011-01-01

The interest in studying metabolic alterations in cancer and their potential role as novel targets for therapy has been rejuvenated in recent years. Here, we report the development of the first genome-scale network model of cancer metabolism, validated by correctly identifying genes essential for cellular proliferation in cancer cell lines. The model predicts 52 cytostatic drug targets, of which 40% are targeted by known, approved or experimental anticancer drugs, and the rest are new. It further predicts combinations of synthetic lethal drug targets, whose synergy is validated using available drug efficacy and gene expression measurements across the NCI-60 cancer cell line collection. Finally, potential selective treatments for specific cancers that depend on cancer type-specific downregulation of gene expression and somatic mutations are compiled. PMID:21694718

Purification and identification of corn peptides that facilitate alcohol metabolism by semi-preparative high-performance liquid chromatography and nano liquid chromatography with electrospray ionization tandem mass spectrometry.

PubMed

Ma, Zhi-Li; Hou, Tao; Shi, Wen; Liu, Wei-Wei; Ibrahim, Salam A; He, Hui

2016-11-01

In this study, peptides that facilitate alcohol metabolism were purified and identified from corn protein hydrolysates. The ultra-filtered fraction with a molecular weight < 3 kDa (F3) potential activity was separated into six fractions (F3-H1-F3-H6) by semi-preparative high-performance liquid chromatography. Among the resultant six fractions, F3-H4 and F3-H5 exhibited the highest ability to eliminate alcohol in vivo. A total of 16 peptides with strong signal values were identified from F3-H4 and F3-H5 fractions by nano liquid chromatography coupled with electrospray ionization tandem mass spectrometry. Several identified peptides were then selected and synthesized to determine their potential to facilitate alcohol metabolism. We found that Leu-Leu and Pro-Phe were the key structure units in Gln-Leu-Leu-Pro-Phe responsible for this peptide's ability to facilitate alcohol metabolism. However, the role of Leu-Leu and Pro-Phe may be affected by peptide chain length and hydrophobic properties. Our results have thus provided some insight into the study of the structure-activity relationships of corn peptides. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tumor-homing peptides as tools for targeted delivery of payloads to the placenta

PubMed Central

King, Anna; Ndifon, Cornelia; Lui, Sylvia; Widdows, Kate; Kotamraju, Venkata R.; Agemy, Lilach; Teesalu, Tambet; Glazier, Jocelyn D.; Cellesi, Francesco; Tirelli, Nicola; Aplin, John D.; Ruoslahti, Erkki; Harris, Lynda K.

2016-01-01

The availability of therapeutics to treat pregnancy complications is severely lacking mainly because of the risk of causing harm to the fetus. As enhancement of placental growth and function can alleviate maternal symptoms and improve fetal growth in animal models, we have developed a method for targeted delivery of payloads to the placenta. We show that the tumor-homing peptide sequences CGKRK and iRGD bind selectively to the placental surface of humans and mice and do not interfere with normal development. Peptide-coated nanoparticles intravenously injected into pregnant mice accumulated within the mouse placenta, whereas control nanoparticles exhibited reduced binding and/or fetal transfer. We used targeted liposomes to efficiently deliver cargoes of carboxyfluorescein and insulin-like growth factor 2 to the mouse placenta; the latter significantly increased mean placental weight when administered to healthy animals and significantly improved fetal weight distribution in a well-characterized model of fetal growth restriction. These data provide proof of principle for targeted delivery of drugs to the placenta and provide a novel platform for the development of placenta-specific therapeutics. PMID:27386551

Metabolism and inactivation of gastrin releasing peptide by endopeptidase-24.11 in the dog.

PubMed

Bunnett, N W; Turner, A J; Debas, H T

1989-09-01

The purpose of this investigation was to examine the metabolism and inactivation of gastrin releasing peptide 10 (GRP10) by endopeptidase-24.11 prepared from the stomach wall. GRP10 was metabolized in vitro by gastric endopeptidase-24.11. The metabolites were purified by high-pressure liquid chromatography and identified as (1-8) GRP10 and (9-10) GRP10 by amino acid analysis, indicating hydrolysis of the His8-Leu9 bond. The intravenous administration of GRP10 to conscious dogs stimulated gastrin release, gastric acid secretion, pancreatic protein secretion and pancreatic bicarbonate secretion. Incubation of GRP10 with endopeptidase-24.11 significantly diminished the biological activity of the digests compared to control digests containing heat-inactivated enzyme. This effect was abolished by the enzyme inhibitor phosphoramidon. It is concluded that endopeptidase-24.11 from the stomach metabolizes and inactivates GRP10.

(99m)Tc-labeled SWL specific peptide for targeting EphA2 receptor.

PubMed

Liu, Yu; Lan, Xiaoli; Wu, Tao; Lang, Juntao; Jin, Xueyan; Sun, Xun; Wen, Qiong; An, Rui

2014-07-01

EphA2, one member of the Eph receptor family, is widely expressed in multiple aggressive cancers. SWL, a small peptide identified by phage display, has high binding affinity to EphA2, suggesting that it could be exploited for targeted molecular imaging. Therefore, a novel peptide-based probe, (99m)Tc-HYNIC-SWL, was developed and its potential to specifically target EphA2-positive tumors was investigated. The SWL peptide was labeled with hydrazinonicotinic acid (HYNIC), followed by (99m)Tc labeling. Immunofluorescence staining was carried out to detect the expression of EphA2 in A549 lung cancer cells and OCM-1 melanoma cells. Saturation binding experiments were performed by incubating A549 cells with increasing concentrations of radiolabeled peptide in vitro. To test the probe in vivo, nude mice bearing either A549 or OCM-1 derived tumors were established, injected with (99m)Tc-HYNIC-SWL, and subjected to SPECT imaging. Mice injected with excess unlabeled SWL were used as a specific control. Ex vivo γ-counting of dissected tissues from the mice was also performed to evaluate biodistribution. Immunofluorescence staining showed that A549 cells intensively expressed EphA2, while OCM-1 cells had little expression. (99m)Tc-HYNIC-SWL displayed high binding affinity with A549 cells (KD=2.6±0.7nM). From the SPECT images and the results of the biodistribution study, significantly higher uptake of the tracer was seen in A549 tumors (1.44±0.12 %ID/g) than in OCM-1 tumors (0.43±0.20 %ID/g) at 1h after injection. Pre-injection with excess unlabeled peptide in A549-bearing nude mice, significantly reduced tumor uptake of the radiolabeled probe (0.58±0.20 %ID/g) was seen. These data suggest that (99m)Tc-HYNIC-SWL specifically targets EphA2 in tumors. The expression of EphA2 can be noninvasively investigated using (99m)Tc-HYNIC-SWL by SPECT imaging. The in vitro and in vivo characteristics of (99m)Tc-HYNIC-SWL make it a promising probe for EphA2-positive tumor imaging

Targeted delivery using peptide-functionalised gold nanoparticles to white adipose tissues of obese rats

NASA Astrophysics Data System (ADS)

Thovhogi, Ntevheleni; Sibuyi, Nicole; Meyer, Mervin; Onani, Martin; Madiehe, Abram

2015-02-01

Obesity is a complex metabolic disease of excessive fat accumulation. It is a worldwide epidemic affecting billions of people. Current pharmacological treatment of obesity remains limited and ineffective due to systemic drug toxicity and undesirable side effects. The current epidemic raises a serious need for development of safer drugs to treat obesity. Nanotechnology-based drug delivery system for administering pharmaceutical compound to achieve therapeutic effects is currently an exciting field in cancer treatment. Drug delivery involves either modification of drug release profile, absorption, distribution and/or elimination, for the benefit of improving drug efficacy and safety. Therefore, nanotechnology holds promise in the treatment of diseases including obesity. Gold nanoparticles (GNPs) functionalised with different biomolecules have been successfully used as drug delivery, labelling and imaging tools in biomedical research. In this study, the binding-specificity and targeting ability of adipose homing peptide (AHP)-functionalised GNPs (AHP-GNPs) were evaluated using flow cytometry and inductively coupled plasma-optical emission spectroscopy. Caco-2 cells and rats fed either chow or a high-fat diet were treated with either unfunctionalised GNPs or AHP-GNPs. Cellular uptake of GNPs was detected in cells treated with AHP-GNPs and not those treated with GNPs alone. Binding of AHP to cells was both temperature- and concentration-dependent. Compared to rats treated with GNPs alone, treatment of obese rats with AHP-GNPs resulted in the targeted delivery of the GNPs to the white adipose tissue (WAT). This paper reports the successful targeting of AHP-functionalised GNPs to WAT of obese rats.

Beta-adrenergic and atrial natriuretic peptide interactions on human cardiovascular and metabolic regulation

PubMed Central

Birkenfeld, Andreas L.; Boschmann, Michael; Moro, Cedric; Adams, Frauke; Heusser, Karsten; Tank, Jens; Diedrich, André; Schroeder, Christoph; Franke, Gabi; Berlan, Michel; Luft, Friedrich C.; Lafontan, Max; Jordan, Jens

2006-01-01

Context Atrial natriuretic peptide (ANP) has well known cardiovascular effects and modifies lipid and carbohydrate metabolism in humans. Objective To determine the metabolic and cardiovascular interaction of beta-adrenergic receptors and ANP. Design Cross over study, conducted 2004–2005 Setting Academic clinical research center Patients Ten healthy, young, male subjects (BMI 24±1 kg/m2) Intervention We infused intravenously incremental ANP doses (6.25, 12.5, and 25 ng/kg/min) with and without propranolol (0.20 mg/kg in divided doses followed by 0.033 mg/kg/h infusion). Metabolism was monitored through venous blood sampling, intramuscular and subcutaneous microdialysis and indirect calorimetry. Cardiovascular changes where monitored by continuous ECG and beat-by-beat blood pressure recordings. Main outcome measures Venous NEFA, glycerol, glucose, insulin; microdialysate glucose, glycerol, lactate, pyruvate. Results ANP increased heart rate dose dependently. Beta-adrenergic receptor blockade abolished the response. ANP elicited a dose-dependent increase in serum non-esterified fatty acid and glycerol concentrations. The response was not suppressed with propranolol. Venous glucose and insulin concentrations increased with ANP, both, without or with propranolol. ANP induced lipid mobilization in subcutaneous adipose tissue. In skeletal muscle, microdialysate lactate increased while the lactate to pyruvate ratio decreased, both, with and without propranolol. Higher ANP doses increased lipid oxidation while energy expenditure remained unchanged. Propranolol tended to attenuate the increase in lipid oxidation. Conclusions Selected cardiovascular ANP effects are at least partly mediated by beta-adrenergic receptor stimulation. ANP induced changes in lipid mobilization and glycolysis are mediated by another mechanism, presumably stimulation of natriuretic peptide receptors whereas substrate oxidation might be modulated through adrenergic mechanisms. PMID:16984990

A Designed Peptide Targets Two Types of Modifications of p53 with Anti-cancer Activity.

PubMed

Liang, Lunxi; Wang, Huanbin; Shi, Hubing; Li, Zhaoli; Yao, Han; Bu, Zhigao; Song, Ningning; Li, Chushu; Xiang, Dabin; Zhang, Yao; Wang, Jilin; Hu, Ye; Xu, Qi; Ma, Yanlei; Cheng, Zhongyi; Wang, Yingchao; Zhao, Shuliang; Qian, Jin; Chen, Yingxuan; Fang, Jing-Yuan; Xu, Jie

2018-06-21

Many cancer-related proteins are controlled by composite post-translational modifications (PTMs), but prevalent strategies only target one type of modification. Here we describe a designed peptide that controls two types of modifications of the p53 tumor suppressor, based on the discovery of a protein complex that suppresses p53 (suppresome). We found that Morn3, a cancer-testis antigen, recruits different PTM enzymes, such as sirtuin deacetylase and ubiquitin ligase, to confer composite modifications on p53. The molecular functions of Morn3 were validated through in vivo assays and chemico-biological intervention. A rationally designed Morn3-targeting peptide (Morncide) successfully activated p53 and suppressed tumor growth. These findings shed light on the regulation of protein PTMs and present a strategy for targeting two modifications with one molecule. Copyright © 2018 Elsevier Ltd. All rights reserved.

Novel phage display-derived neuroblastoma-targeting peptides potentiate the effect of drug nanocarriers in preclinical settings.

PubMed

Loi, Monica; Di Paolo, Daniela; Soster, Marco; Brignole, Chiara; Bartolini, Alice; Emionite, Laura; Sun, Jessica; Becherini, Pamela; Curnis, Flavio; Petretto, Andrea; Sani, Monica; Gori, Alessandro; Milanese, Marco; Gambini, Claudio; Longhi, Renato; Cilli, Michele; Allen, Theresa M; Bussolino, Federico; Arap, Wadih; Pasqualini, Renata; Corti, Angelo; Ponzoni, Mirco; Marchiò, Serena; Pastorino, Fabio

2013-09-10

Molecular targeting of drug delivery nanocarriers is expected to improve their therapeutic index while decreasing their toxicity. Here we report the identification and characterization of novel peptide ligands specific for cells present in high-risk neuroblastoma (NB), a childhood tumor mostly refractory to current therapies. To isolate such targeting moieties, we performed combined in vitro/ex-vivo phage display screenings on NB cell lines and on tumors derived from orthotopic mouse models of human NB. By designing proper subtractive protocols, we identified phage clones specific either for the primary tumor, its metastases, or for their respective stromal components. Globally, we isolated 121 phage-displayed NB-binding peptides: 26 bound the primary tumor, 15 the metastatic mass, 57 and 23 their respective microenvironments. Of these, five phage clones were further validated for their specific binding ex-vivo to biopsies from stage IV NB patients and to NB tumors derived from mice. All five clones also targeted tumor cells and vasculature in vivo when injected into NB-bearing mice. Coupling of the corresponding targeting peptides with doxorubicin-loaded liposomes led to a significant inhibition in tumor volume and enhanced survival in preclinical NB models, thereby paving the way to their clinical development. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Membrane-targeted self-assembling cyclic peptide nanotubes.

PubMed

Rodríguez-Vázquez, Nuria; Ozores, H Lionel; Guerra, Arcadio; González-Freire, Eva; Fuertes, Alberto; Panciera, Michele; Priegue, Juan M; Outeiral, Juan; Montenegro, Javier; Garcia-Fandino, Rebeca; Amorin, Manuel; Granja, Juan R

2014-01-01

Peptide nanotubes are novel supramolecular nanobiomaterials that have a tubular structure. The stacking of cyclic components is one of the most promising strategies amongst the methods described in recent years for the preparation of nanotubes. This strategy allows precise control of the nanotube surface properties and the dimensions of the tube diameter. In addition, the incorporation of 3- aminocycloalkanecarboxylic acid residues in the nanotube-forming peptides allows control of the internal properties of the supramolecular tube. The research aimed at the application of membrane-interacting self-assembled cyclic peptide nanotubes (SCPNs) is summarized in this review. The cyclic peptides are designed to interact with phospholipid bilayers to induce nanotube formation. The properties and orientation of the nanotube can be tuned by tailoring the peptide sequence. Hydrophobic peptides form transmembrane pores with a hydrophilic orifice, the nature of which has been exploited to transport ions and small molecules efficiently. These synthetic ion channels are selective for alkali metal ions (Na(+), K(+) or Cs(+)) over divalent cations (Ca(2+)) or anions (Cl(-)). Unfortunately, selectivity was not achieved within the series of alkali metal ions, for which ion transport rates followed the diffusion rates in water. Amphipathic peptides form nanotubes that lie parallel to the membrane. Interestingly, nanotube formation takes place preferentially on the surface of bacterial membranes, thus making these materials suitable for the development of new antimicrobial agents.

RGD peptide-modified multifunctional dendrimer platform for drug encapsulation and targeted inhibition of cancer cells.

PubMed

He, Xuedan; Alves, Carla S; Oliveira, Nilsa; Rodrigues, João; Zhu, Jingyi; Bányai, István; Tomás, Helena; Shi, Xiangyang

2015-01-01

Development of multifunctional nanoscale drug-delivery systems for targeted cancer therapy still remains a great challenge. Here, we report the synthesis of cyclic arginine-glycine-aspartic acid (RGD) peptide-conjugated generation 5 (G5) poly(amidoamine) dendrimers for anticancer drug encapsulation and targeted therapy of cancer cells overexpressing αvβ3 integrins. In this study, amine-terminated G5 dendrimers were used as a platform to be sequentially modified with fluorescein isothiocyanate (FI) via a thiourea linkage and RGD peptide via a polyethylene glycol (PEG) spacer, followed by acetylation of the remaining dendrimer terminal amines. The developed multifunctional dendrimer platform (G5.NHAc-FI-PEG-RGD) was then used to encapsulate an anticancer drug doxorubicin (DOX). We show that approximately six DOX molecules are able to be encapsulated within each dendrimer platform. The formed complexes are water-soluble, stable, and able to release DOX in a sustained manner. One- and two-dimensional NMR techniques were applied to investigate the interaction between dendrimers and DOX, and the impact of the environmental pH on the release rate of DOX from the dendrimer/DOX complexes was also explored. Furthermore, cell biological studies demonstrate that the encapsulation of DOX within the G5.NHAc-FI-PEG-RGD dendrimers does not compromise the anticancer activity of DOX and that the therapeutic efficacy of the dendrimer/DOX complexes is solely related to the encapsulated DOX drug. Importantly, thanks to the role played by RGD-mediated targeting, the developed dendrimer/drug complexes are able to specifically target αvβ3 integrin-overexpressing cancer cells and display specific therapeutic efficacy to the target cells. The developed RGD peptide-targeted multifunctional dendrimers may thus be used as a versatile platform for targeted therapy of different types of αvβ3 integrin-overexpressing cancer cells. Copyright © 2014 Elsevier B.V. All rights reserved.

The apelin peptides as putative targets in cardiovascular drug discovery and development.

PubMed

Charles, Cj

2008-01-01

Apelin is a recently isolated peptide that appears to act as an endogenous ligand for the previously orphaned G-protein-coupled receptor APJ. A number of studies have reported cardiovascular actions of apelin, including changes in the blood pressure and potent inotropic actions. Furthermore, perturbations of both apelin and APJ within the myocardial tissue and circulating levels of the peptide have been reported in a number of cardiovascular disease states. Taken together, these studies suggest a role for apelin in the pressure/volume homeostasis and in the pathophysiology of cardiovascular diseases. However, findings in the literature to date are, at times, disparate. This review highlights key areas where further work is required to clarify the role of apelin/APJ in both normal physiology and pathophysiology. Nonetheless, preliminary evidence suggests that the manipulation of this receptor/ligand peptide system may be a target for drug development, thereby offering a therapeutic benefit in cardiovascular diseases.

Biodiscovery of aluminum binding peptides

NASA Astrophysics Data System (ADS)

Adams, Bryn L.; Sarkes, Deborah A.; Finch, Amethist S.; Hurley, Margaret M.; Stratis-Cullum, Dimitra

2013-05-01

Cell surface peptide display systems are large and diverse libraries of peptides (7-15 amino acids) which are presented by a display scaffold hosted by a phage (virus), bacteria, or yeast cell. This allows the selfsustaining peptide libraries to be rapidly screened for high affinity binders to a given target of interest, and those binders quickly identified. Peptide display systems have traditionally been utilized in conjunction with organic-based targets, such as protein toxins or carbon nanotubes. However, this technology has been expanded for use with inorganic targets, such as metals, for biofabrication, hybrid material assembly and corrosion prevention. While most current peptide display systems employ viruses to host the display scaffold, we have recently shown that a bacterial host, Escherichia coli, displaying peptides in the ubiquitous, membrane protein scaffold eCPX can also provide specific peptide binders to an organic target. We have, for the first time, extended the use of this bacterial peptide display system for the biodiscovery of aluminum binding 15mer peptides. We will present the process of biopanning with macroscopic inorganic targets, binder enrichment, and binder isolation and discovery.

Chimeric peptides as modulators of CK2-dependent signaling: Mechanism of action and off-target effects.

PubMed

Zanin, Sofia; Sandre, Michele; Cozza, Giorgio; Ottaviani, Daniele; Marin, Oriano; Pinna, Lorenzo A; Ruzzene, Maria

2015-10-01

Protein kinase CK2 is a tetrameric enzyme composed of two catalytic (α/α') and two regulatory (β) subunits. It has a global prosurvival function, especially in cancer, and represents an attractive therapeutic target. Most CK2 inhibitors available so far are ATP-competitive compounds; however, the possibility to block only the phosphorylation of few substrates has been recently explored, and a compound composed of a Tat cell-penetrating peptide and an active cyclic peptide, selected for its ability to bind to the CK2 substrate E7 protein of human papilloma virus, has been developed [Perea et al., Cancer Res. 2004; 64:7127-7129]. By using a similar chimeric peptide (CK2 modulatory chimeric peptide, CK2-MCP), we performed a study to dissect its molecular mechanism of action and the signaling pathways that it affects in cells. We found that it directly interacts with CK2 itself, counteracting the regulatory and stabilizing functions of the β subunit. Cell treatment with CK2-MCP induces a rapid decrease of the amount of CK2 subunits, as well as of other signaling proteins. Concomitant cell death is observed, more pronounced in tumor cells and not accompanied by apoptotic events. CK2 relocalizes to lysosomes, whose proteases are activated, while the proteasome machinery is inhibited. Several sequence variants of the chimeric peptide have been also synthesized, and their effects compared to those of the parental peptide. Intriguingly, the Tat moiety is essential not only for cell penetration but also for the in vitro efficacy of the peptide. We conclude that this class of chimeric peptides, in addition to altering some properties of CK2 holoenzyme, affects several other cellular targets, causing profound perturbations of cell biology. This article is part of a Special Issue entitled: Inhibitors of Protein Kinases. Copyright © 2015 Elsevier B.V. All rights reserved.

Targeted Delivery of Ubiquitin-Conjugated BH3 Peptide-Based Mcl-1 Inhibitors into Cancer Cells

PubMed Central

2015-01-01

BH3 peptides are key mediators of apoptosis and have served as the lead structures for the development of anticancer therapeutics. Previously, we reported the application of a simple cysteine-based side chain cross-linking chemistry to NoxaBH3 peptides that led to the generation of the cross-linked NoxaBH3 peptides with increased cell permeability and higher inhibitory activity against Mcl-1 (Muppidi, A., Doi, K., Edwardraja, S., Drake, E. J., Gulick, A. M., Wang, H.-G., Lin, Q. (2012) J. Am. Chem. Soc.134, 1473422920569). To deliver cross-linked NoxaBH3 peptides selectively into cancer cells for enhanced efficacy and reduced systemic toxicity, here we report the conjugation of the NoxaBH3 peptides with the extracellular ubiquitin, a recently identified endogenous ligand for CXCR4, a chemokine receptor overexpressed in cancer cells. The resulting ubiquitin-NoxaBH3 peptide conjugates showed increased inhibitory activity against Mcl-1 and selective killing of the CXCR4-expressing cancer cells. The successful delivery of the NoxaBH3 peptides by ubiquitin into cancer cells suggests that the ubiquitin/CXCR4 axis may serve as a general route for the targeted delivery of anticancer agents. PMID:24410055

Towards Discovery and Targeted Peptide Biomarker Detection Using nanoESI-TIMS-TOF MS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garabedian, Alyssa; Benigni, Paolo; Ramirez, Cesar E.

Abstract. In the present work, the potential of trapped ion mobility spectrometry coupled to TOF mass spectrometry (TIMS-TOF MS) for discovery and targeted monitoring of peptide biomarkers from human-in-mouse xenograft tumor tissue was evaluated. In particular, a TIMS-MS workflow was developed for the detection and quantification of peptide biomarkers using internal heavy analogs, taking advantage of the high mobility resolution (R = 150–250) prior to mass analysis. Five peptide biomarkers were separated, identified, and quantified using offline nanoESI-TIMSCID- TOF MS; the results were in good agreement with measurements using a traditional LC-ESI-MS/MS proteomics workflow. The TIMS-TOF MS analysis permitted peptidemore » biomarker detection based on accurate mobility, mass measurements, and high sequence coverage for concentrations in the 10–200 nM range, while simultaneously achieving discovery measurements« less

Efficient Subcellular Targeting to the Cell Nucleus of Quantum Dots Densely Decorated with a Nuclear Localization Sequence Peptide.

PubMed

Maity, Amit Ranjan; Stepensky, David

2016-01-27

Organelle-targeted drug delivery can enhance the efficiency of the intracellularly acting drugs and reduce their toxicity. We generated core-shell type CdSe-ZnS quantum dots (QDs) densely decorated with NLS peptidic targeting residues using a 3-stage decoration approach and investigated their endocytosis and nuclear targeting efficiencies. The diameter of the generated QDs increased following the individual decoration stages (16.3, 18.9, and 21.9 nm), the ζ-potential became less negative (-33.2, -17.5, and -11.9 mV), and characteristic changes appeared in the FTIR spectra following decoration with the linker and NLS peptides. Quantitative analysis of the last decoration stage revealed that 37.9% and 33.2% of the alkyne-modified NLS groups that were added to the reaction mix became covalently attached or adsorbed to the QDs surface, respectively. These numbers correspond to 63.6 and 55.7 peptides conjugated or adsorbed to a single QD (the surface density of 42 and 37 conjugated and adsorbed peptides per 1000 nm(2) of the QDs surface), which is higher than in the majority of previous studies that reported decoration efficiencies of formulations intended for nuclear-targeted drug delivery. QDs decorated with NLS peptides undergo more efficient endocytosis, as compared to other investigated QDs formulations, and accumulated to a higher extent in the cell nucleus or in close vicinity to it (11.9%, 14.6%, and 56.1% of the QDs endocytosed by an average cell for the QD-COOH, QD-azide, and QD-NLS formulations, respectively). We conclude that dense decoration of QDs with NLS residues increased their endocytosis and led to their nuclear targeting (preferential accumulation in the cells nuclei or in close vicinity to them). The experimental system and research tools that were used in this study allow quantitative investigation of the mechanisms that govern the QDs nuclear targeting and their dependence on the formulation properties. These findings will contribute to the

Clinical Efficacy of a Specifically Targeted Antimicrobial Peptide Mouth Rinse: Targeted Elimination of Streptococcus mutans and Prevention of Demineralization

PubMed Central

Sullivan, R.; Santarpia, P.; Lavender, S.; Gittins, E.; Liu, Z.; Anderson, M.H.; He, J.; Shi, W.; Eckert, R.

2011-01-01

Background/Aims Streptococcus mutans, the major etiological agent of dental caries, has a measurable impact on domestic and global health care costs. Though persistent in the oral cavity despite conventional oral hygiene, S. mutans can be excluded from intact oral biofilms through competitive exclusion by other microorganisms. This suggests that therapies capable of selectively eliminating S. mutans while limiting the damage to the normal oral flora might be effective long-term interventions to fight cariogenesis. To meet this challenge, we designed C16G2, a novel synthetic specifically targeted antimicrobial peptide with specificity for S. mutans. C16G2 consists of a S. mutans-selective ‘targeting region’ comprised of a fragment from S. mutans competence stimulation peptide (CSP) conjoined to a ‘killing region’ consisting of a broad-spectrum antimicrobial peptide (G2). In vitro studies have indicated that C16G2 has robust efficacy and selectivity for S. mutans, and not other oral bacteria, and affects targeted bacteria within seconds of contact. Methods In the present study, we evaluated C16G2 for clinical utility in vitro, followed by a pilot efficacy study to examine the impact of a 0.04% (w/v) C16G2 rinse in an intra-oral remineralization/demineralization model. Results and Conclusions C16G2 rinse usage was associated with reductions in plaque and salivary S. mutans, lactic acid production, and enamel demineralization. The impact on total plaque bacteria was minimal. These results suggest that C16G2 is effective against S. mutans in vivo and should be evaluated further in the clinic. PMID:21860239

A DNA Nanotube-Peptide biocomplex for mRNA Detection and Its Application in Cancer Diagnosis and Targeted Therapy.

PubMed

Ji, Xiaoting; Lv, Haoyuan; Guo, Jiayi; Ding, Caifeng; Luo, Xiliang

2018-04-25

A biocomplex of DNA nanotube-peptide, consisting of six concatenated DNA strands, three lock DNA strands and a cell-penetrating peptide was developed herein. The barrel structured DNA nanotube-peptide was successfully applied as a co-drug delivery system for targeting cancer therapy. The mucin 1 proteins (MUC-1) aptamer which is part of DNA nanotube can specially recognize MUC-1 protein on the surface of MCF-7 cells. Cyclo (Arg-Gly-Asp-D-phe-Lys) (cRGD), as a cell-penetrating peptide, facilitates recruitment and uptake of targeting drugs by binding to integrin receptors (αvβ3) of cytomembrane surface. Anti-cancer drug doxorubicin (DOX) and paclitaxel (PTX) were loaded into the capsulated DNA nanotube-peptide (CDNP), which was used as co-drug cargo models. The as-prepared biocomplex can be utilized not only to deliver drug but also to achieve the anticancer effect in vivo. The experimental results suggested that the treatment efficacy of co-drug delivery platform (CDNP/DOX/PTX) was better than single-drug delivery platform (CDNP/DOX or CDNP/PTX). This system that was composed by DNA strands and peptide has good biocompatibility and biodegradability. Furthermore, the system can readily achieve detection of target mRNA of MCF-7 cell in vitro. The detection limits of mRNA are 9.7×10-8 M and 1.8×10-8 M by using CDNP/DOX and CDNP/PTX-FITC as a probe, respectively. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and exploration of novel radiolabeled bombesin peptides for targeting receptor positive tumor.

PubMed

De, Kakali; Banerjee, Indranil; Sinha, Samarendu; Ganguly, Shantanu

2017-03-01

Increasing evidence of peptide receptor overexpression in various cancer cells, warrant the development of receptor specific radiolabeled peptides for molecular imaging and therapy in nuclear medicine. Gastrin-releasing-peptide (GRP) receptor, are overexpressed in a variety of human cancer cells. The present study report the synthesis and biological evaluation of new bombesin (BBN) analogs, HYNIC-Asp-[Phe 13 ]BBN(7-13)-NH-CH 2 -CH 2 -CH3:BA1, HYNIC-Pro-[Tyr 13 Met 14 ]BBN(7-14)NH 2 :BA2 as prospective tumor imaging agent with compare to BBN(7-14)NH 2 :BS as standard. The pharmacophores were radiolabeled in high yields with 99m Tc, characterized for their stability in serum and saline, cysteine/histidine and were found to be substantially stable. Internalization/externalization and receptor binding studies were assessed using MDA-MB-231 cells and showed high receptor binding-affinity and favourable internalization. Fluorescence studies revealed that BA1 changed the morphology of the cells and could localize in the nucleus more effectively than BA2/BS. Cell-viability studies displayed substantial antagonistic and nuclear-internalization effect of BA1. BA1 also exhibited antiproliferative effect on MDA-MB-231 cell by inducing apoptosis. In vivo behaviour of the radiopeptides was evaluated in GRP receptor positive tumor bearing mice. The 99m Tc-BA1/ 99m Tc-BA2 demonstrated rapid blood/urinary clearance through the renal pathway and comparatively more significant tumor uptake image and favourable tumor-to-non-target ratios provided by 99m Tc-BA1. The specificity of the in vivo uptake was confirmed by co-injection with BS. Moreover, 99m Tc-BA1 provided a much clearer tumor image in scintigraphic studies than others. Thus the combination of favourable in vitro and in vivo properties renders BA1 as more potential antagonist bombesin-peptide for targeting GRP-receptor positive tumor. These properties are encouraging to carry out further experiments for non-invasive receptor

Receptor-targeted liposome-peptide-siRNA nanoparticles represent an efficient delivery system for MRTF silencing in conjunctival fibrosis

NASA Astrophysics Data System (ADS)

Yu-Wai-Man, Cynthia; Tagalakis, Aristides D.; Manunta, Maria D.; Hart, Stephen L.; Khaw, Peng T.

2016-02-01

There is increasing evidence that the Myocardin-related transcription factor/Serum response factor (MRTF/SRF) pathway plays a key role in fibroblast activation and that knocking down MRTF can lead to reduced scarring and fibrosis. Here, we have developed a receptor-targeted liposome-peptide-siRNA nanoparticle as a non-viral delivery system for MRTF-B siRNA in conjunctival fibrosis. Using 50 nM siRNA, the MRTF-B gene was efficiently silenced by 76% and 72% with LYR and LER nanoparticles, respectively. The silencing efficiency was low when non-targeting peptides or siRNA alone or liposome-siRNA alone were used. LYR and LER nanoparticles also showed higher silencing efficiency than PEGylated LYR-P and LER-P nanoparticles. The nanoparticles were not cytotoxic using different liposomes, targeting peptides, and 50 nM siRNA. Three-dimensional fibroblast-populated collagen matrices were also used as a functional assay to measure contraction in vitro, and showed that MRTF-B LYR nanoparticles completely blocked matrix contraction after a single transfection treatment. In conclusion, this is the first study to develop and show that receptor-targeted liposome-peptide-siRNA nanoparticles represent an efficient and safe non-viral siRNA delivery system that could be used to prevent fibrosis after glaucoma filtration surgery and other contractile scarring conditions in the eye.

A target-unrelated peptide in an M13 phage display library traced to an advantageous mutation in the gene II ribosome-binding site.

PubMed

Brammer, Leighanne A; Bolduc, Benjamin; Kass, Jessica L; Felice, Kristin M; Noren, Christopher J; Hall, Marilena Fitzsimons

2008-02-01

Screening of the commercially available Ph.D.-7 phage-displayed heptapeptide library for peptides that bind immobilized Zn2+ resulted in the repeated selection of the peptide HAIYPRH, although binding assays indicated that HAIYPRH is not a zinc-binding peptide. HAIYPRH has also been selected in several other laboratories using completely different targets, and its ubiquity suggests that it is a target-unrelated peptide. We demonstrated that phage displaying HAIYPRH are enriched after serial amplification of the library without exposure to target. The amplification of phage displaying HAIYPRH was found to be dramatically faster than that of the library itself. DNA sequencing uncovered a mutation in the Shine-Dalgarno (SD) sequence for gIIp, a protein involved in phage replication, imparting to the SD sequence better complementarity to the 16S ribosomal RNA (rRNA). Introducing this mutation into phage lacking a displayed peptide resulted in accelerated propagation, whereas phage displaying HAIYPRH with a wild-type SD sequence were found to amplify normally. The SD mutation may alter gIIp expression and, consequently, the rate of propagation of phage. In the Ph.D.-7 library, the mutation is coincident with the displayed peptide HAIYPRH, accounting for the target-unrelated selection of this peptide in multiple reported panning experiments.

The utility of tumor-specifically internalizing peptides for targeted siRNA delivery into human solid tumors.

PubMed

Un, Frank; Zhou, Bingsen; Yen, Yun

2012-11-01

Ribonucleotide reductase composed of the hRRM1 and hRRM2 subunits catalyzes the conversion of ribonucleotides to their corresponding deoxy forms for DNA replication. Anti-hRRM2 siRNA degrades hRRM2's mRNA and suppresses tumorigenesis. A Phase I clinical trial demonstrated its therapy potential. HN-1 represents a tumor-specifically internalizing peptide for targeted-drug delivery into human head and neck squamous cell carcinoma. Internalization of peptide was monitored by fluorescence microscopy. The peptide-siRNA conjugate was chemically synthesized. The hRRM2 expression was monitored by western blot analysis. HN-1(TYR) (HN-1 with two N-terminally added tyrosines) was internalized by human head and neck or breast cancer cells. Anti-hRRM2 siRNA(R) (resistant to RNase degradation) was conjugated to HN-1(TYR) without compromising their properties. The treatment with HN-1(TYR)-anti-hRRM2 siRNA(R) partly suppressed the endogenously expressed hRRM2 in human breast cancer cells. Our results establish the utility of tumor-specifically internalizing peptides for targeted siRNA delivery into human cancer cells.

Neuropeptide Y and peptide YY: important regulators of energy metabolism.

PubMed

Nguyen, Amy D; Herzog, Herbert; Sainsbury, Amanda

2011-02-01

An overview of recent developments documenting the neuropeptide Y (NPY) family's role in energy metabolism. Specifically focusing on site-specific functions of NPY and increasing evidence of peptide YY (PYY) as a weight loss therapeutic. Studying the NPY family in hypothalamic nuclei, other than the arcuate and paraventricular nuclei, is a recent shift in metabolic research. NPY overexpression in the dorsomedial hypothalamus increases food intake whereas its ablation in this area reduces hyperphagia and obesity. Similarly, NPY exerts orexigenic effects in the ventromedial nucleus. However, specific arcuate Y2 receptor ablation leads to positive energy balance, suggesting the NPY family demonstrates location-specific functions. Peripherally, dual blockade of cannabinoid and NPY pathways has synergistic effects on weight loss, as does combined administration of PYY3-36 and oxyntomodulin in reducing food intake, perhaps due to the recently discovered role of PYY in mediating intestinal Gpr119 activity and controlling glucose tolerance. Conditional Y receptor knockout models have provided deeper insights on NPY's functions according to location. Further study of PYY appears vital, due to recent evidence of its role in intestinal motility, with exercise positively influencing PYY levels.

Inhibition of Dengue Virus Entry into Target Cells Using Synthetic Antiviral Peptides

PubMed Central

Alhoot, Mohammed Abdelfatah; Rathinam, Alwin Kumar; Wang, Seok Mui; Manikam, Rishya; Sekaran, Shamala Devi

2013-01-01

Despite the importance of DENV as a human pathogen, there is no specific treatment or protective vaccine. Successful entry into the host cells is necessary for establishing the infection. Recently, the virus entry step has become an attractive therapeutic strategy because it represents a barrier to suppress the onset of the infection. Four putative antiviral peptides were designed to target domain III of DENV-2 E protein using BioMoDroid algorithm. Two peptides showed significant inhibition of DENV when simultaneously incubated as shown by plaque formation assay, RT-qPCR, and Western blot analysis. Both DET4 and DET2 showed significant inhibition of virus entry (84.6% and 40.6% respectively) using micromolar concentrations. Furthermore, the TEM images showed that the inhibitory peptides caused structural abnormalities and alteration of the arrangement of the viral E protein, which interferes with virus binding and entry. Inhibition of DENV entry during the initial stages of infection can potentially reduce the viremia in infected humans resulting in prevention of the progression of dengue fever to the severe life-threatening infection, reduce the infected vector numbers, and thus break the transmission cycle. Moreover these peptides though designed against the conserved region in DENV-2 would have the potential to be active against all the serotypes of dengue and might be considered as Hits to begin designing and developing of more potent analogous peptides that could constitute as promising therapeutic agents for attenuating dengue infection. PMID:23630436

Update on apelin peptides as putative targets for cardiovascular drug discovery.

PubMed

Charles, Christopher J

2011-06-01

The physiological importance of GPCR/ligand pathways is highlighted by the fact that numerous pathologies are attributed to their signaling dysfunction. Over 50% of the pharmaceutical drugs currently used to treat human disease are based on compounds that interact with GPCRs. Apelin/APJ constitutes a novel endogenous peptide/GPCR system proposed to be involved in a wide range of physiological functions. Early evidence suggests that apelin/APJ may hold promise as a target for development of novel therapeutic agents which may counteract a number of pathologies including cardiovascular disease. Despite advances in treatment of cardiovascular disease, incidence, prevalence, morbidity and economic costs remain high necessitating the development of new treatment paradigms. This review summarizes apelin/APJ structure, distribution and regulation; presents evidence for a role of apelin in pressure/volume homeostasis and in the pathophysiology of cardiovascular disease; summarizes data on beneficial effects of apelin in preclinical, animal models of cardiovascular disease and measurement of plasma levels of apelin across the full spectrum of cardiovascular disease in humans; and notes the first studies describing bioactivity of apelin peptides in human healthy volunteers and patients with heart failure. More clarity is needed on the precise physiological/pathophysiological role of the apelin/APJ system in human health and disease. Nonetheless, preclinical studies and initial studies in humans show that APJ antagonism may represent a novel therapeutic target for patients with cardiovascular disease. Development of appropriately validated assays for apelin will clarify circulating levels of the peptide in health and disease. Development of suitable agonists/antagonists will pave the way for much needed future studies essential for advancing this promising field of drug discovery.

Development of Y-shaped peptide for constructing nanoparticle systems targeting tumor-associated macrophages in vitro and in vivo

NASA Astrophysics Data System (ADS)

Yan, Lu; Gao, Yunxiang; Pierce, Ryan; Dai, Liming; Kim, Julian; Zhang, Mei

2014-04-01

Tumor-associated macrophage (TAM) is increasingly being viewed as a target of great interest in tumor microenvironment due to its important role in the progression and metastasis of cancers. It has been shown that TAM indeed overexpresses unique surface marker legumain. In this study, we designed and synthesized a Y-shaped legumain-targeting peptide (Y-Leg) with functional groups allowing for further conjugation with imaging and therapeutic moieties (vide infra). The in vitro cell experiments using FITC-conjugated Y-Leg revealed its specific and selective interaction with M2-polarized macrophages (i.e., TAMs) with preference to M1 macrophages, and that the interaction was not interfered with by conjugating FITC to its functional group. Further, we constructed a nanotube system by grafting Y-Leg onto oxidized carbon nanotubes (OCNTs) loaded with paramagnetic Fe3O4 nanoparticles. The intravenous injection of the resultant Y-Leg-OCNT/Fe3O4 nanotubes to 4T1 mammary tumor-bearing mouse led to the magnetic resonance imaging (MRI) of TAM-infiltrated tumor microenvironment, revealing the targeting specificity of Y-Leg-conjugated nanotubes in vivo. The Y shape of peptide and its functional groups containing amines and imidazole can protonate at different pHs, contributing to the in vitro and in vivo targeting specificity. This study represents the first development of novel peptide and peptide-grafted nanotube system targeting M2-polarized TAMs in vivo. The methodology developed in this study is applicable to the construction of various multifunctional nanoparticle systems for selectively targeting, imaging and manipulating of TAMs for the diagnosis and treatment of cancers and inflammatory diseases identified with macrophage-infiltrated disease tissue.

MESSI: metabolic engineering target selection and best strain identification tool.

PubMed

Kang, Kang; Li, Jun; Lim, Boon Leong; Panagiotou, Gianni

2015-01-01

Metabolic engineering and synthetic biology are synergistically related fields for manipulating target pathways and designing microorganisms that can act as chemical factories. Saccharomyces cerevisiae's ideal bioprocessing traits make yeast a very attractive chemical factory for production of fuels, pharmaceuticals, nutraceuticals as well as a wide range of chemicals. However, future attempts of engineering S. cerevisiae's metabolism using synthetic biology need to move towards more integrative models that incorporate the high connectivity of metabolic pathways and regulatory processes and the interactions in genetic elements across those pathways and processes. To contribute in this direction, we have developed Metabolic Engineering target Selection and best Strain Identification tool (MESSI), a web server for predicting efficient chassis and regulatory components for yeast bio-based production. The server provides an integrative platform for users to analyse ready-to-use public high-throughput metabolomic data, which are transformed to metabolic pathway activities for identifying the most efficient S. cerevisiae strain for the production of a compound of interest. As input MESSI accepts metabolite KEGG IDs or pathway names. MESSI outputs a ranked list of S. cerevisiae strains based on aggregation algorithms. Furthermore, through a genome-wide association study of the metabolic pathway activities with the strains' natural variation, MESSI prioritizes genes and small variants as potential regulatory points and promising metabolic engineering targets. Users can choose various parameters in the whole process such as (i) weight and expectation of each metabolic pathway activity in the final ranking of the strains, (ii) Weighted AddScore Fuse or Weighted Borda Fuse aggregation algorithm, (iii) type of variants to be included, (iv) variant sets in different biological levels.Database URL: http://sbb.hku.hk/MESSI/. © The Author(s) 2015. Published by Oxford University

Targeted Type 1 phototherapeutic agents using azido-peptide bioconjugates

NASA Astrophysics Data System (ADS)

Rajagopalan, Raghavan; Achilefu, Samuel I.; Jimenez, Hermo N.; Webb, Elizabeth G.; Schmidt, Michelle A.; Bugaj, Joseph E.; Dorshow, Richard B.

2001-07-01

Five peptides binding to somatostatin and bombesin receptors were conjugated to 4-azido-2,3,4,6-tetrafluorophenylbenzoic acid, a Type 1 photosensitizer, at the N-terminal position. The receptor affinities were determined by competition binding assay using two different pancreatic tumor cell lines, CA20948 and AR42-J, that expresses somatostatin-2 (SST-2) and bombesin receptors receptively. All compounds exhibited high receptor specificity, i.e., the IC50 values ranged between 1.0 to 64.0 nM. These conjugates may be useful for targeted Type 1 phototherapy via the generation of nitrenes at the cell surfaces expressing these receptors.

Efficient Identification of Murine M2 Macrophage Peptide Targeting Ligands by Phage Display and Next-Generation Sequencing.

PubMed

Liu, Gary W; Livesay, Brynn R; Kacherovsky, Nataly A; Cieslewicz, Maryelise; Lutz, Emi; Waalkes, Adam; Jensen, Michael C; Salipante, Stephen J; Pun, Suzie H

2015-08-19

Peptide ligands are used to increase the specificity of drug carriers to their target cells and to facilitate intracellular delivery. One method to identify such peptide ligands, phage display, enables high-throughput screening of peptide libraries for ligands binding to therapeutic targets of interest. However, conventional methods for identifying target binders in a library by Sanger sequencing are low-throughput, labor-intensive, and provide a limited perspective (<0.01%) of the complete sequence space. Moreover, the small sample space can be dominated by nonspecific, preferentially amplifying "parasitic sequences" and plastic-binding sequences, which may lead to the identification of false positives or exclude the identification of target-binding sequences. To overcome these challenges, we employed next-generation Illumina sequencing to couple high-throughput screening and high-throughput sequencing, enabling more comprehensive access to the phage display library sequence space. In this work, we define the hallmarks of binding sequences in next-generation sequencing data, and develop a method that identifies several target-binding phage clones for murine, alternatively activated M2 macrophages with a high (100%) success rate: sequences and binding motifs were reproducibly present across biological replicates; binding motifs were identified across multiple unique sequences; and an unselected, amplified library accurately filtered out parasitic sequences. In addition, we validate the Multiple Em for Motif Elicitation tool as an efficient and principled means of discovering binding sequences.

Molecular imaging and therapy targeting copper metabolism in hepatocellular carcinoma

PubMed Central

Wachsmann, Jason; Peng, Fangyu

2016-01-01

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. Significant efforts have been devoted to identify new biomarkers for molecular imaging and targeted therapy of HCC. Copper is a nutritional metal required for the function of numerous enzymatic molecules in the metabolic pathways of human cells. Emerging evidence suggests that copper plays a role in cell proliferation and angiogenesis. Increased accumulation of copper ions was detected in tissue samples of HCC and many other cancers in humans. Altered copper metabolism is a new biomarker for molecular cancer imaging with position emission tomography (PET) using radioactive copper as a tracer. It has been reported that extrahepatic mouse hepatoma or HCC xenografts can be localized with PET using copper-64 chloride as a tracer, suggesting that copper metabolism is a new biomarker for the detection of HCC metastasis in areas of low physiological copper uptake. In addition to copper modulation therapy with copper chelators, short-interference RNA specific for human copper transporter 1 (hCtr1) may be used to suppress growth of HCC by blocking increased copper uptake mediated by hCtr1. Furthermore, altered copper metabolism is a promising target for radionuclide therapy of HCC using therapeutic copper radionuclides. Copper metabolism has potential as a new theranostic biomarker for molecular imaging as well as targeted therapy of HCC. PMID:26755872

Modulation of hydrogel nanoparticle intracellular trafficking by multivalent surface engineering with tumor targeting peptide

NASA Astrophysics Data System (ADS)

Karamchand, Leshern; Kim, Gwangseong; Wang, Shouyan; Hah, Hoe Jin; Ray, Aniruddha; Jiddou, Ruba; Koo Lee, Yong-Eun; Philbert, Martin A.; Kopelman, Raoul

2013-10-01

Surface engineering of a hydrogel nanoparticle (NP) with the tumor-targeting ligand, F3 peptide, enhances both the NP's binding affinity for, and internalization by, nucleolin overexpressing tumor cells. Remarkably, the F3-functionalized NPs consistently exhibited significantly lower trafficking to the degradative lysosomes than the non-functionalized NPs, in the tumor cells, after internalization. This is attributed to the non-functionalized NPs, but not the F3-functionalized NPs, being co-internalized with Lysosome-associated Membrane Protein-1 (LAMP1) from the surface of the tumor cells. Furthermore, it is shown that the intracellular trafficking of the F3-functionalized NPs differs significantly from that of the molecular F3 peptides (untethered to NPs). This has important implications for designing effective, chemically-responsive, controlled-release and multifunctional nanodrugs for multi-drug-resistant cancers.Surface engineering of a hydrogel nanoparticle (NP) with the tumor-targeting ligand, F3 peptide, enhances both the NP's binding affinity for, and internalization by, nucleolin overexpressing tumor cells. Remarkably, the F3-functionalized NPs consistently exhibited significantly lower trafficking to the degradative lysosomes than the non-functionalized NPs, in the tumor cells, after internalization. This is attributed to the non-functionalized NPs, but not the F3-functionalized NPs, being co-internalized with Lysosome-associated Membrane Protein-1 (LAMP1) from the surface of the tumor cells. Furthermore, it is shown that the intracellular trafficking of the F3-functionalized NPs differs significantly from that of the molecular F3 peptides (untethered to NPs). This has important implications for designing effective, chemically-responsive, controlled-release and multifunctional nanodrugs for multi-drug-resistant cancers. Electronic supplementary information (ESI) available: Effect of Potassium depletion on F3 peptide subcellular localization, MTT

A Peptide Targeting Inflammatory CNS Lesions in the EAE Rat Model of Multiple Sclerosis.

PubMed

Boiziau, Claudine; Nikolski, Macha; Mordelet, Elodie; Aussudre, Justine; Vargas-Sanchez, Karina; Petry, Klaus G

2018-06-01

Multiple sclerosis is characterized by inflammatory lesions dispersed throughout the central nervous system (CNS) leading to severe neurological handicap. Demyelination, axonal damage, and blood brain barrier alterations are hallmarks of this pathology, whose precise processes are not fully understood. In the experimental autoimmune encephalomyelitis (EAE) rat model that mimics many features of human multiple sclerosis, the phage display strategy was applied to select peptide ligands targeting inflammatory sites in CNS. Due to the large diversity of sequences after phage display selection, a bioinformatics procedure called "PepTeam" designed to identify peptides mimicking naturally occurring proteins was used, with the goal to predict peptides that were not background noise. We identified a circular peptide CLSTASNSC called "Ph48" as an efficient binder of inflammatory regions of EAE CNS sections including small inflammatory lesions of both white and gray matter. Tested on human brain endothelial cells hCMEC/D3, Ph48 was able to bind efficiently when these cells were activated with IL1β to mimic inflammatory conditions. The peptide is therefore a candidate for further analyses of the molecular alterations in inflammatory lesions.

Circulating insulin-like peptide 5 levels and its association with metabolic and hormonal parameters in women with polycystic ovary syndrome.

PubMed

Bicer, M; Alan, M; Alarslan, P; Guler, A; Kocabas, G U; Imamoglu, C; Aksit, M; Bozkaya, G; Isil, A M; Baloglu, A; Aslanipoiur, B; Calan, Mehmet

2018-06-28

Insulin-like peptide 5 (INSL5) is a gut peptide hormone that is a member of relaxin/insulin superfamily. Growing evidence implicates the crucial role of the peptide in some metabolisms including food intake, glucose homeostasis and reproductive system. Polycystic ovary syndrome (PCOS) is involved in both reproductive and metabolic issues. The aim of the study was determination of circulating levels of INSL5 alteration in women with PCOS and evaluation of the relationship between INSL5 and hormonal-metabolic parameters as well as carotid intima media thickness (cIMT). A total of 164 subjects were recruited in this cross-sectional study (82 women with PCOS and 82 age- and BMI-matched controls). Circulating INSL5 levels were assessed via ELISA method. High-resolution B-mode ultrasound was used to measure cIMT. The hormonal and metabolic parameters of the recruited subjects were determined. Circulating INSL5 levels were significantly elevated in women with PCOS compared to controls (27.63 ± 7.74 vs. 19.90 ± 5.85 ng/ml, P < 0.001). The mean values of INSL5 were significantly higher in overweight subjects compared to lean weight subjects in both groups. The women with PCOS having insulin resistance have increased INSL5 compared to those of PCOS subjects without insulin resistance. INSL5 is associated with insulin resistance, BMI, luteinizing hormone and free androgen index. Multivariate logistic regression analyses revealed that the odds ratio for having PCOS in the highest tertile of INSL5 was higher than in the lowest tertile. PCOS subjects exhibited an elevation in circulating INSL5 levels along with a link between INSL5 level induction and metabolic-hormonal parameters.

Liposomes containing NY‑ESO‑1/tetanus toxoid and adjuvant peptides targeted to human dendritic cells via the Fc receptor for cancer vaccines.

PubMed

Cruz, Luis J; Rueda, Felix; Simón, Lorena; Cordobilla, Begoña; Albericio, Fernando; Domingo, Joan C

2014-04-01

To improve the immunological response against tumors, a vaccine based on nanoliposomes targeted to the Fcg-receptor was developed to enhance the immunogenicity of tumor-associated antigens (TAAs). Using human dendritic cells in vitro, a fragment of the TAA NY-ESO-1 combined with a T-helper peptide from the tetanus toxoid encapsulated in nanoliposomes was evaluated. In addition, peptides Palm-IL-1 and MAP-IFN-g were coadministered as adjuvants to enhance the immunological response. Coadministration of Palm-IL-1 or MAP-IFN-g peptide adjuvants and the hybrid NY-ESO-1-tetanus toxoid (soluble or encapsulated in nanoliposomes without targeting) increased immunogenicity. However, the most potent immunological response was obtained when the peptide adjuvants were encapsulated in liposomes targeted to human dendritic cells via the Fc receptor. This targeted vaccine strategy is a promising tool to activate and deliver antigens to dendritic cells, thus improving immunotherapeutic response in situations in which the immune system is frequently compromised, as in advanced cancers.

NMR investigations of the dual targeting peptide of Thr-tRNA synthetase and its interaction with the mitochondrial Tom20 receptor in Arabidopsis thaliana.

PubMed

Ye, Weihua; Spånning, Erika; Unnerståle, Sofia; Gotthold, David; Glaser, Elzbieta; Mäler, Lena

2012-10-01

Most mitochondrial proteins are synthesized in the cytosol as precursor proteins containing an N-terminal targeting peptide and are imported into mitochondria through the import machineries, the translocase of the outer mitochondrial membrane (TOM) and the translocase of the inner mitochondrial membrane (TIM). The N-terminal targeting peptide of precursor proteins destined for the mitochondrial matrix is recognized by the Tom20 receptor and plays an important role in the import process. Protein import is usually organelle specific, but several plant proteins are dually targeted into mitochondria and chloroplasts using an ambiguous dual targeting peptide. We present NMR studies of the dual targeting peptide of Thr-tRNA synthetase and its interaction with Tom20 in Arabidopsis thaliana. Our findings show that the targeting peptide is mostly unstructured in buffer, with a propensity to form α-helical structure in one region, S6-F27, and a very weak β-strand propensity for Q34-Q38. The α-helical structured region has an amphiphilic character and a φχχφφ motif, both of which have previously been shown to be important for mitochondrial import. Using NMR we have mapped out two regions in the peptide that are important for Tom20 recognition: one of them, F9-V28, overlaps with the amphiphilic region, and the other comprises residues L30-Q39. Our results show that the targeting peptide may interact with Tom20 in several ways. Furthermore, our results indicate a weak, dynamic interaction. The results provide for the first time molecular details on the interaction of the Tom20 receptor with a dual targeting peptide. © 2012 The Authors Journal compilation © 2012 FEBS.

Mitochondria targeted peptides protect against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine neurotoxicity.

PubMed

Yang, Lichuan; Zhao, Kesheng; Calingasan, Noel Y; Luo, Guoxiong; Szeto, Hazel H; Beal, M Flint

2009-09-01

A large body of evidence suggests that mitochondrial dysfunction and oxidative damage play a role in the pathogenesis of Parkinson's disease (PD). A number of antioxidants have been effective in animal models of PD. We have developed a family of mitochondria-targeted peptides that can protect against mitochondrial swelling and apoptosis (SS peptides). In this study, we examined the ability of two peptides, SS-31 and SS-20, to protect against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) neurotoxicity in mice. SS-31 produced dose-dependent complete protection against loss of dopamine and its metabolites in striatum, as well as loss of tyrosine hydroxylase immunoreactive neurons in substantia nigra pars compacta. SS-20, which does not possess intrinsic ability in scavenging reactive oxygen species, also demonstrated significant neuroprotective effects on dopaminergic neurons of MPTP-treated mice. Both SS-31 and SS-20 were very potent (nM) in preventing MPP+ (1-methyl-4-phenylpyridinium)-induced cell death in cultured dopamine cells (SN4741). Studies with isolated mitochondria showed that both SS-31 and SS-20 prevented MPP+-induced inhibition of oxygen consumption and ATP production, and mitochondrial swelling. These findings provide strong evidence that these neuroprotective peptides, which target both mitochondrial dysfunction and oxidative damage, are a promising approach for the treatment of PD.

Evaluating Ga-68 Peptide Conjugates for Targeting VPAC Receptors: Stability and Pharmacokinetics.

PubMed

Kumar, Pardeep; Tripathi, Sushil K; Chen, C P; Wickstrom, Eric; Thakur, Mathew L

2018-05-25

In recent years, considerable progress has been made in the use of gallium-68 labeled receptor-specific peptides for imaging oncologic diseases. The objective was to examine the stability and pharmacokinetics of [ 68 Ga]NODAGA and DOTA-peptide conjugate targeting VPAC [combined for vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating peptide (PACAP)] receptors on tumor cells. A VPAC receptor-specific peptide was chosen as a model peptide and conjugated to NODAGA and DOTA via solid-phase synthesis. The conjugates were characterized by HPLC and MALDI-TOF. Following Ga-68 chelation, the radiochemical purity of Ga-68 labeled peptide conjugate was determined by radio-HPLC. The stability was tested against transmetallation using 100 nM Fe 3+ /Zn 2+ /Ca 2+ ionic solution and against transchelation using 200 μM DTPA solution. The ex vivo and in vivo stability of the Ga-68 labeled peptide conjugate was tested in mouse plasma and urine. Receptor specificity was determined ex vivo by cell binding assays using human breast cancer BT474 cells. Positron emission tomography (PET)/X-ray computed tomography (CT) imaging, tissue distribution, and blocking studies were performed in mice bearing BT474 xenografts. The chemical and radiochemical purity was greater than 95 % and both conjugates were stable against transchelation and transmetallation. Ex vivo stability at 60 min showed that the NODAGA-peptide-bound Ga-68 reduced to 42.1 ± 3.7 % (in plasma) and 37.4 ± 2.9 % (in urine), whereas the DOTA-peptide-bound Ga-68 was reduced to 1.2 ± 0.3 % (in plasma) and 4.2 ± 0.4 % (in urine) at 60 min. Similarly, the in vivo stability for [ 68 Ga]NODAGA-peptide was decreased to 2.1 ± 0.2 % (in plasma) and 2.2 ± 0.4 % (in urine). For [ 68 Ga]DOTA-peptide, it was decreased to 1.4 ± 0.3 % (in plasma) and 1.2 ± 0.4 % (in urine) at 60 min. The specific BT474 cell binding was 53.9 ± 0.8 % for [ 68 Ga]NODAGA-peptide

C-Peptide Is a Sensitive Indicator for the Diagnosis of Metabolic Syndrome in Subjects from Central Mexico.

PubMed

Gonzalez-Mejia, M Elba; Porchia, Leonardo M; Torres-Rasgado, Enrique; Ruiz-Vivanco, Guadalupe; Pulido-Pérez, Patricia; Báez-Duarte, Blanca G; Pérez-Fuentes, Ricardo

2016-05-01

Metabolic Syndrome (MetS) is associated with elevated risk for developing diabetes and cardiovascular disease. A key component of MetS is the development of insulin resistance (IR). The homeostatic model assessment (HOMA) model can determine IR by using insulin or C-peptide concentrations; however, the efficiency of insulin and C-peptide to determine MetS has not been compared. The aim of the study was to compare the efficiency of C-peptide and insulin to determine MetS in Mexicans. Anthropometrics, glucose, insulin, C-peptide, triglycerides, and high-density lipoproteins were determined in 156 nonpregnant females and 114 males. Subjects were separated into normal or positive for MetS. IR was determined by the HOMA2 calculator using insulin or C-peptide. Correlations were calculated using the Spearman correlation coefficient (ρ). Differences between correlations were determined by calculating Steiger's Z. The sensitivity was determined by the area under receiver operating characteristics curve (AUC) analysis. Independent of the MetS definition [Adult Treatment Panel III (ATP III), International Diabetes Federation (IDF), or World Health Organization (WHO)], C-peptide and insulin were significantly higher in MetS subjects (P < 0.05). C-peptide and insulin correlated with all components of MetS; however, for waist circumference, waist-to-hip ratio, and fasting plasma glucose, C-peptide correlated better than insulin (P < 0.05). Moreover, C-peptide (AUC = 0.72-0.78) was a better marker than insulin (AUC = 0.62-0.72) for MetS (P < 0.05). Finally, HOMA2-IR calculated with C-peptide (AUC = 0.80-0.84) was more accurate than HOMA2-IR calculated with insulin (AUC = 0.68-0.75, P < 0.05) at determining MetS. C-peptide is a strong indicator of MetS. Since C-peptide has recently emerged as a biomolecule with significant importance for inflammatory diseases, monitoring C-peptide levels will aid clinicians in preventing MetS.

Thermally targeted delivery of chemotherapeutics and anti-cancer peptides by elastin-like polypeptide.

PubMed

Raucher, Drazen; Massodi, Iqbal; Bidwell, Gene L

2008-03-01

Current chemotherapy treatment of solid tumors is limited due to a lack of specific delivery of the drugs to the tumor, leading to systemic toxicity. Therefore, it is necessary to develop targeted cancer therapies and tumor-targeted drug carriers. The authors review the development of elastin-like polypeptide (ELP) as a potential carrier for thermally targeted delivery of therapeutics. The authors searched Medline for articles concerning the application of ELP as a drug delivery vector for small molecule drugs and therapeutic peptides. ELP has been demonstrated to be a promising thermally targeted carrier. Further examination of the in vivo biodistribution and efficacy will provide the necessary data to advance ELP technology toward the ultimate goal of human therapeutics.

Delivery of Small Interfering RNA by Peptide-Targeted Mesoporous Silica Nanoparticle-Supported Lipid Bilayers

PubMed Central

Ashley, Carlee E.; Carnes, Eric C.; Epler, Katharine E.; Padilla, David P.; Phillips, Genevieve K.; Castillo, Robert E.; Wilkinson, Dan C.; Wilkinson, Brian S.; Burgard, Cameron A.; Sewell, Robin M.; Townson, Jason L.; Chackerian, Bryce; Willman, Cheryl L.; Peabody, David S.; Wharton, Walker; Brinker, C. Jeffrey

2012-01-01

The therapeutic potential of small interfering RNAs (siRNAs) is severely limited by the availability of delivery platforms that protect siRNA from degradation, deliver it to the target cell with high specificity and efficiency, and promote its endosomal escape and cytosolic dispersion. Here we report that mesoporous silica nanoparticle-supported lipid bilayers (or ‘protocells’), exhibit multiple properties that overcome many of the limitations of existing delivery platforms. Protocells have a 10- to 100-fold greater capacity for siRNA than corresponding lipid nanoparticles and are markedly more stable when incubated under physiological conditions. Protocells loaded with a cocktail of siRNAs bind to cells in a manner dependent on the presence of an appropriate targeting peptide and, through an endocytic pathway followed by endosomal disruption, promote delivery of the silencing nucleotides to the cytoplasm. The expression of each of the genes targeted by the siRNAs was shown to be repressed at the protein level, resulting in a potent induction of growth arrest and apoptosis. Incubation of control cells that lack expression of the antigen recognized by the targeting peptide with siRNA-loaded protocells induced neither repression of protein expression nor apoptosis, indicating the precise specificity of cytotoxic activity. In terms of loading capacity, targeting capabilities, and potency of action, protocells provide unique attributes as a delivery platform for therapeutic oligonucleotides. PMID:22309035

A versatile targeting system with lentiviral vectors bearing the biotin-adaptor peptide

PubMed Central

Morizono, Kouki; Xie, Yiming; Helguera, Gustavo; Daniels, Tracy R.; Lane, Timothy F.; Penichet, Manuel L.; Chen, Irvin S. Y.

2010-01-01

Background Targeted gene transduction in vivo is the ultimate preferred method for gene delivery. We previously developed targeting lentiviral vectors that specifically recognize cell surface molecules with conjugated antibodies and mediate targeted gene transduction both in vitro and in vivo. Although effective in some experimental settings, the conjugation of virus with antibodies is mediated by the interaction between protein A and the Fc region of antibodies, which is not as stable as covalent conjugation. We have now developed a more stable conjugation strategy utilizing the interaction between avidin and biotin. Methods We inserted the biotin-adaptor-peptide, which was biotinylated by secretory biotin ligase at specific sites, into our targeting envelope proteins, enabling conjugation of the pseudotyped virus with avidin, streptavidin or neutravidin. Results When conjugated with avidin-antibody fusion proteins or the complex of avidin and biotinylated targeting molecules, the vectors could mediate specific transduction to targeted cells recognized by the targeting molecules. When conjugated with streptavidin-coated magnetic beads, transduction by the vectors was targeted to the locations of magnets. Conclusions This targeting vector system can be used for broad applications of targeted gene transduction using biotinylated targeting molecules or targeting molecules fused with avidin. PMID:19455593

Widespread occurrence of both metabolic and target-site herbicide resistance mechanisms in Lolium rigidum populations.

PubMed

Han, Heping; Yu, Qin; Owen, Mechelle J; Cawthray, Gregory R; Powles, Stephen B

2016-02-01

Lolium rigidum populations in Australia and globally have demonstrated rapid and widespread evolution of resistance to acetyl coenzyme A carboxylase (ACCase)-inhibiting and acetolactate synthase (ALS)-inhibiting herbicides. Thirty-three resistant L. rigidum populations, randomly collected from crop fields in a most recent resistance survey, were analysed for non-target-site diclofop metabolism and all known target-site ACCase gene resistance-endowing mutations. The HPLC profile of [(14) C]-diclofop-methyl in vivo metabolism revealed that 79% of these resistant L. rigidum populations showed enhanced capacity for diclofop acid metabolism (metabolic resistance). ACCase gene sequencing identified that 91% of the populations contain plants with ACCase resistance mutation(s). Importantly, 70% of the populations exhibit both non-target-site metabolic resistance and target-site ACCase mutations. This work demonstrates that metabolic herbicide resistance is commonly occurring in L. rigidum, and coevolution of both metabolic resistance and target-site resistance is an evolutionary reality. Metabolic herbicide resistance can potentially endow resistance to many herbicides and poses a threat to herbicide sustainability and thus crop production, calling for major research and management efforts. © 2015 Society of Chemical Industry.

Medicinal Chemistry of ATP Synthase: A Potential Drug Target of Dietary Polyphenols and Amphibian Antimicrobial Peptides

PubMed Central

Ahmad, Zulfiqar; Laughlin, Thomas F.

2015-01-01

In this review we discuss the inhibitory effects of dietary polyphenols and amphibian antimicrobial/antitumor peptides on ATP synthase. In the beginning general structural features highlighting catalytic and motor functions of ATP synthase will be described. Some details on the presence of ATP synthase on the surface of several animal cell types, where it is associated with multiple cellular processes making it an interesting drug target with respect to dietary polyphenols and amphibian antimicrobial peptides will also be reviewed. ATP synthase is known to have distinct polyphenol and peptide binding sites at the interface of α/β subunits. Molecular interaction of polyphenols and peptides with ATP synthase at their respective binding sites will be discussed. Binding and inhibition of other proteins or enzymes will also be covered so as to understand the therapeutic roles of both types of molecules. Lastly, the effects of polyphenols and peptides on the inhibition of Escherichia coli cell growth through their action on ATP synthase will also be presented. PMID:20586714

Targeted imaging of esophageal neoplasia with a fluorescently labeled peptide: First in-human results

PubMed Central

Sturm, Matthew B.; Joshi, Bishnu P.; Lu, Shaoying; Piraka, Cyrus; Khondee, Supang; Elmunzer, B. Joseph; Kwon, Richard S.; Beer, David G.; Appelman, Henry; Turgeon, D. Kim; Wang, Thomas D.

2013-01-01

Esophageal adenocarcinoma is rising rapidly in incidence, and usually develops from Barrett’s esophagus, a precursor condition commonly found in patients with chronic acid reflux. Pre-malignant lesions are challenging to detect on conventional screening endoscopy because of their flat appearance. Molecular changes can be used to improve detection of early neoplasia. We have developed a peptide that binds specifically to high-grade dysplasia and adenocarcinoma. We first applied the peptide ex vivo to esophageal specimens from 17 patients to validate specific binding. Next, we performed confocal endomicroscopy in vivo in 25 human subjects after topical peptide administration and found 3.8-fold greater fluorescence intensity for esophageal neoplasia compared with Barrett’s esophagus and squamous epithelium with 75% sensitivity and 97% specificity. No toxicity was attributed to the peptide in either animal or patient studies. Therefore, our first-in-humans results show that this targeted imaging agent is safe, and may be useful for guiding tissue biopsy and for early detection of esophageal neoplasia and potentially other cancers of epithelial origin, such as bladder, colon, lung, pancreas, and stomach. PMID:23658246

Cathepsin-Mediated Cleavage of Peptides from Peptide Amphiphiles Leads to Enhanced Intracellular Peptide Accumulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Acar, Handan; Samaeekia, Ravand; Schnorenberg, Mathew R.

Peptides synthesized in the likeness of their native interaction domain(s) are natural choices to target protein protein interactions (PPIs) due to their fidelity of orthostatic contact points between binding partners. Despite therapeutic promise, intracellular delivery of biofunctional peptides at concentrations necessary for efficacy remains a formidable challenge. Peptide amphiphiles (PAs) provide a facile method of intracellular delivery and stabilization of bioactive peptides. PAs consisting of biofunctional peptide headgroups linked to hydrophobic alkyl lipid-like tails prevent peptide hydrolysis and proteolysis in circulation, and PA monomers are internalized via endocytosis. However, endocytotic sequestration and steric hindrance from the lipid tail are twomore » major mechanisms that limit PA efficacy to target intracellular PPIs. To address these problems, we have constructed a PA platform consisting of cathepsin-B cleavable PAs in which a selective p53-based inhibitory peptide is cleaved from its lipid tail within endosomes, allowing for intracellular peptide accumulation and extracellular recycling of the lipid moiety. We monitor for cleavage and follow individual PA components in real time using a resonance energy transfer (FRET)-based tracking system. Using this platform, components in real time using a Forster we provide a better understanding and quantification of cellular internalization, trafficking, and endosomal cleavage of PAs and of the ultimate fates of each component.« less

Delivery of siRNA using ternary complexes containing branched cationic peptides: the role of peptide sequence, branching and targeting.

PubMed

Kudsiova, Laila; Welser, Katharina; Campbell, Frederick; Mohammadi, Atefeh; Dawson, Natalie; Cui, Lili; Hailes, Helen C; Lawrence, M Jayne; Tabor, Alethea B

2016-03-01

Ternary nanocomplexes, composed of bifunctional cationic peptides, lipids and siRNA, as delivery vehicles for siRNA have been investigated. The study is the first to determine the optimal sequence and architecture of the bifunctional cationic peptide used for siRNA packaging and delivery using lipopolyplexes. Specifically three series of cationic peptides of differing sequence, degrees of branching and cell-targeting sequences were co-formulated with siRNA and vesicles prepared from a 1 : 1 molar ratio of the cationic lipid DOTMA and the helper lipid, DOPE. The level of siRNA knockdown achieved in the human alveolar cell line, A549-luc cells, in both reduced serum and in serum supplemented media was evaluated, and the results correlated to the nanocomplex structure (established using a range of physico-chemical tools, namely small angle neutron scattering, transmission electron microscopy, dynamic light scattering and zeta potential measurement); the conformational properties of each component (circular dichroism); the degree of protection of the siRNA in the lipopolyplex (using gel shift assays) and to the cellular uptake, localisation and toxicity of the nanocomplexes (confocal microscopy). Although the size, charge, structure and stability of the various lipopolyplexes were broadly similar, it was clear that lipopolyplexes formulated from branched peptides containing His-Lys sequences perform best as siRNA delivery agents in serum, with protection of the siRNA in serum balanced against efficient release of the siRNA into the cytoplasm of the cell.

Targeting Unique Metabolic Properties of Breast Tumor Initiating Cells

PubMed Central

Feng, Weiguo; Gentles, Andrew; Nair, Ramesh V.; Huang, Min; Lin, Yuan; Lee, Cleo Y.; Cai, Shang; Scheeren, Ferenc A.; Kuo, Angera H.; Diehn, Maximilian

2014-01-01

Normal stem cells from a variety of tissues display unique metabolic properties compared to their more differentiated progeny. However, relatively little is known about heterogeneity of metabolic properties cancer stem cells, also called tumor initiating cells (TICs). In this study we show that, analogous to some normal stem cells, breast TICs have distinct metabolic properties compared to non-tumorigenic cancer cells (NTCs). Transcriptome profiling using RNA-Seq revealed TICs under-express genes involved in mitochondrial biology and mitochondrial oxidative phosphorylation and metabolic analyses revealed TICs preferentially perform glycolysis over oxidative phosphorylation compared to NTCs. Mechanistic analyses demonstrated that decreased expression and activity of pyruvate dehydrogenase (Pdh), a key regulator of oxidative phosphorylation, play a critical role in promoting the pro-glycolytic phenotype of TICs. Metabolic reprogramming via forced activation of Pdh preferentially eliminates TICs both in vitro and in vivo. Our findings reveal unique metabolic properties of TICs and demonstrate that metabolic reprogramming represents a promising strategy for targeting these cells. PMID:24497069

Integrating Transcriptomics with Metabolic Modeling Predicts Biomarkers and Drug Targets for Alzheimer's Disease

PubMed Central

Stempler, Shiri; Yizhak, Keren; Ruppin, Eytan

2014-01-01

Accumulating evidence links numerous abnormalities in cerebral metabolism with the progression of Alzheimer's disease (AD), beginning in its early stages. Here, we integrate transcriptomic data from AD patients with a genome-scale computational human metabolic model to characterize the altered metabolism in AD, and employ state-of-the-art metabolic modelling methods to predict metabolic biomarkers and drug targets in AD. The metabolic descriptions derived are first tested and validated on a large scale versus existing AD proteomics and metabolomics data. Our analysis shows a significant decrease in the activity of several key metabolic pathways, including the carnitine shuttle, folate metabolism and mitochondrial transport. We predict several metabolic biomarkers of AD progression in the blood and the CSF, including succinate and prostaglandin D2. Vitamin D and steroid metabolism pathways are enriched with predicted drug targets that could mitigate the metabolic alterations observed. Taken together, this study provides the first network wide view of the metabolic alterations associated with AD progression. Most importantly, it offers a cohort of new metabolic leads for the diagnosis of AD and its treatment. PMID:25127241

Early and late HIV-1 membrane fusion events are impaired by sphinganine lipidated peptides that target the fusion site.

PubMed

Klug, Yoel A; Ashkenazi, Avraham; Viard, Mathias; Porat, Ziv; Blumenthal, Robert; Shai, Yechiel

2014-07-15

Lipid-conjugated peptides have advanced the understanding of membrane protein functions and the roles of lipids in the membrane milieu. These lipopeptides modulate various biological systems such as viral fusion. A single function has been suggested for the lipid, binding to the membrane and thus elevating the local concentration of the peptide at the target site. In the present paper, we challenged this argument by exploring in-depth the antiviral mechanism of lipopeptides, which comprise sphinganine, the lipid backbone of DHSM (dihydrosphingomyelin), and an HIV-1 envelope-derived peptide. Surprisingly, we discovered a partnership between the lipid and the peptide that impaired early membrane fusion events by reducing CD4 receptor lateral diffusion and HIV-1 fusion peptide-mediated lipid mixing. Moreover, only the joint function of sphinganine and its conjugate peptide disrupted HIV-1 fusion protein assembly and folding at the later fusion steps. Via imaging techniques we revealed for the first time the direct localization of these lipopeptides to the virus-cell and cell-cell contact sites. Overall, the findings of the present study may suggest lipid-protein interactions in various biological systems and may help uncover a role for elevated DHSM in HIV-1 and its target cell membranes.

Re-programming tumour cell metabolism to treat cancer: no lone target for lonidamine.

PubMed

Bhutia, Yangzom D; Babu, Ellappan; Ganapathy, Vadivel

2016-06-01

Tumour cell metabolism is very different from normal cell metabolism; cancer cells re-programme the metabolic pathways that occur in normal cells in such a manner that it optimizes their proliferation, growth and survival. Although this metabolic re-programming obviously operates to the advantage of the tumour, it also offers unique opportunities for effective cancer therapy. Molecules that target the tumour cell-specific metabolic pathways have potential as novel anti-cancer drugs. Lonidamine belongs to this group of molecules and is already in use in some countries for cancer treatment. It has been known for a long time that lonidamine interferes with energy production in tumour cells by inhibiting hexokinase II (HKII), a glycolytic enzyme. However, subsequent studies have uncovered additional pharmacological targets for the drug, which include the electron transport chain and the mitochondrial permeability transition pore, thus expanding the pharmacological effects of the drug on tumour cell metabolism. A study by Nancolas et al. in a recent issue of the Biochemical Journal identifies two additional new targets for lonidamine: the pyruvate transporter in the mitochondria and the H(+)-coupled monocarboxylate transporters in the plasma membrane (PM). It is thus becoming increasingly apparent that the anti-cancer effects of lonidamine do not occur through a single target; the drug works at multiple sites. Irrespective of the molecular targets, what lonidamine does in the end is to undo what the tumour cells have done in terms of re-programming cellular metabolism and mitochondrial function. © 2016 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Gut microbiota controls adipose tissue expansion, gut barrier and glucose metabolism: novel insights into molecular targets and interventions using prebiotics.

PubMed

Geurts, L; Neyrinck, A M; Delzenne, N M; Knauf, C; Cani, P D

2014-03-01

Crosstalk between organs is crucial for controlling numerous homeostatic systems (e.g. energy balance, glucose metabolism and immunity). Several pathological conditions, such as obesity and type 2 diabetes, are characterised by a loss of or excessive inter-organ communication that contributes to the development of disease. Recently, we and others have identified several mechanisms linking the gut microbiota with the development of obesity and associated disorders (e.g. insulin resistance, type 2 diabetes, hepatic steatosis). Among these, we described the concept of metabolic endotoxaemia (increase in plasma lipopolysaccharide levels) as one of the triggering factors leading to the development of metabolic inflammation and insulin resistance. Growing evidence suggests that gut microbes contribute to the onset of low-grade inflammation characterising these metabolic disorders via mechanisms associated with gut barrier dysfunctions. We have demonstrated that enteroendocrine cells (producing glucagon-like peptide-1, peptide YY and glucagon-like peptide-2) and the endocannabinoid system control gut permeability and metabolic endotoxaemia. Recently, we hypothesised that specific metabolic dysregulations occurring at the level of numerous organs (e.g. gut, adipose tissue, muscles, liver and brain) rely from gut microbiota modifications. In this review, we discuss the mechanisms linking gut permeability, adipose tissue metabolism, and glucose homeostasis, and recent findings that show interactions between the gut microbiota, the endocannabinoid system and the apelinergic system. These specific systems are discussed in the context of the gut-to-peripheral organ axis (intestine, adipose tissue and brain) and impacts on metabolic regulation. In the present review, we also briefly describe the impact of a variety of non-digestible nutrients (i.e. inulin-type fructans, arabinoxylans, chitin glucans and polyphenols). Their effects on the composition of the gut microbiota and

SIKVAV peptide functionalized ultra-small gold nanoparticles for selective targeting of α6β1 integrin in hepatocellular carcinoma

NASA Astrophysics Data System (ADS)

Roskamp, M.; Coulter, T.; Ding, Y.; Perrins, R.; Espinosa Garcia, C.; Pace, A.; Hale, S.; Robinson, A.; Williams, P.; Aguilera Peral, U.; Patel, K.; Palmer, D.

2017-04-01

Ultra-small glycan-passivated gold nanoparticles of <2nm diameter were funtionalised with a short HS-EG(8)-COOH ligand. The nanoparticles were subsequently labelled, in a stoichiometrically controllable manner, with integrin-binding peptide SIKVAV and the maytansinoid cytotoxin DM4. In vitro assays showed significantly increased integrin-mediated uptake of SIKVAV labelled nanoparticles in HepG2 cells. SIKVAV targeted nanoparticle binding was shown to be outcompeted with free SIKVAV peptide, indicating target specific uptake. DM4 was passively attached to nanoparticles via sulfhydryl ligand exchange at the gold nanoparticle surface, which rendered them highly cytotoxic (IC50 ˜1 × 10-9M). In a rat model, pharmacokinetic studies showed that nanoparticle biodistribution was strongly altered by labelling with either peptide and DM4 moieties.

One-carbon metabolism and nucleotide biosynthesis as attractive targets for anticancer therapy

PubMed Central

Shuvalov, Oleg; Petukhov, Alexey; Daks, Alexandra; Fedorova, Olga; Vasileva, Elena; Barlev, Nickolai A.

2017-01-01

Cancer-related metabolism has recently emerged as one of the “hallmarks of cancer”. It has several important features, including altered metabolism of glucose and glutamine. Importantly, altered cancer metabolism connects different biochemical pathways into the one fine-tuned metabolic network, which stimulates high proliferation rates and plasticity to malignant cells. Among the keystones of cancer metabolism are one-carbon metabolism and nucleotide biosynthesis, which provide building blocks to anabolic reactions. Accordingly, the importance of these metabolic pathways for anticancer therapy has well been documented by more than fifty years of clinical use of specific metabolic inhibitors – methotrexate and nucleotides analogs. In this review we discuss one-carbon metabolism and nucleotide biosynthesis as common and specific features of many, if not all, tumors. The key enzymes involved in these pathways also represent promising anti-cancer therapeutic targets. We review different aspects of these metabolic pathways including their biochemistry, compartmentalization and expression of the key enzymes and their regulation at different levels. We also discuss the effects of known inhibitors of these pathways as well as the recent data on other enzymes of the same pathways as perspective pharmacological targets. PMID:28177894

Current scenario of peptide-based drugs: the key roles of cationic antitumor and antiviral peptides

PubMed Central

Mulder, Kelly C. L.; Lima, Loiane A.; Miranda, Vivian J.; Dias, Simoni C.; Franco, Octávio L.

2013-01-01

Cationic antimicrobial peptides (AMPs) and host defense peptides (HDPs) show vast potential as peptide-based drugs. Great effort has been made in order to exploit their mechanisms of action, aiming to identify their targets as well as to enhance their activity and bioavailability. In this review, we will focus on both naturally occurring and designed antiviral and antitumor cationic peptides, including those here called promiscuous, in which multiple targets are associated with a single peptide structure. Emphasis will be given to their biochemical features, selectivity against extra targets, and molecular mechanisms. Peptides which possess antitumor activity against different cancer cell lines will be discussed, as well as peptides which inhibit virus replication, focusing on their applications for human health, animal health and agriculture, and their potential as new therapeutic drugs. Moreover, the current scenario for production and the use of nanotechnology as delivery tool for both classes of cationic peptides, as well as the perspectives on improving them is considered. PMID:24198814

Abnormalities of peptide metabolism in Alzheimer disease.

PubMed

Panchal, Maï; Rholam, Mohamed; Brakch, Noureddine

2004-10-01

The steady-state level of peptide hormones represents a balance between their biosynthesis and proteolytic processing by convertases and their catabolism by proteolytic enzymes. Low levels of neuropeptide Y, somatostatin and corticotropin-releasing factor, described in Alzheimer disease (AD), were related to a defect in proteolytic processing of their protein precursors. In contrast the abundance of beta-amyloid peptides, the major protein constituents of senile plaques is likely related to inefficient catabolism. Therefore, attention is mainly focused on convertases that generate active peptides and counter-regulatory proteases that are involved in their catabolism. Some well-described proteases such as NEP are thought to be involved in beta-amyloid catabolism. The search of other possible candidates represents a primary effort in the field. A variety of vascular risk factors such as diabetes, hypertension and arteriosclerosis suggest that the functional vascular defect contributes to AD pathology. It has also been described that beta-amyloid peptides potentiate endothelin-1 induced vasoconstriction. In this review, we will critically evaluate evidence relating proteases implicated in amyloid protein precursor proteolytic processing and beta-amyloid catabolism.

Improving Peptide Applications Using Nanotechnology.

PubMed

Narayanaswamy, Radhika; Wang, Tao; Torchilin, Vladimir P

2016-01-01

Peptides are being successfully used in various fields including therapy and drug delivery. With advancement in nanotechnology and targeted delivery carrier systems, suitable modification of peptides has enabled achievement of many desirable goals over-riding some of the major disadvantages associated with the delivery of peptides in vivo. Conjugation or physical encapsulation of peptides to various nanocarriers, such as liposomes, micelles and solid-lipid nanoparticles, has improved their in vivo performance multi-fold. The amenability of peptides to modification in chemistry and functionalization with suitable nanocarriers are very relevant aspects in their use and have led to the use of 'smart' nanoparticles with suitable linker chemistries that favor peptide targeting or release at the desired sites, minimizing off-target effects. This review focuses on how nanotechnology has been used to improve the number of peptide applications. The paper also focuses on the chemistry behind peptide conjugation to nanocarriers, the commonly employed linker chemistries and the several improvements that have already been achieved in the areas of peptide use with the help of nanotechnology.

Targeting SREBP-1-driven lipid metabolism to treat cancer

PubMed Central

Guo, Deliang; Bell, Erica Hlavin; Mischel, Paul; Chakravarti, Arnab

2014-01-01

Metabolic reprogramming is a hallmark of cancer. Oncogenic growth signaling regulates glucose, glutamine and lipid metabolism to meet the bioenergetics and biosynthetic demands of rapidly proliferating tumor cells. Emerging evidence indicates that sterol regulatory element-binding protein 1 (SREBP-1), a master transcription factor that controls lipid metabolism, is a critical link between oncogenic signaling and tumor metabolism. We recently demonstrated that SREBP-1 is required for the survival of mutant EGFR-containing glioblastoma, and that this pro-survival metabolic pathway is mediated, in part, by SREBP-1-dependent upregulation of the fatty acid synthesis and low density lipoprotein (LDL) receptor (LDLR). These results have identified EGFR/PI3K/Akt/SREBP-1 signaling pathway that promotes growth and survival in glioblastoma, and potentially other cancer types. Here, we summarize recent insights in the understanding of cancer lipid metabolism, and discuss the evidence linking SREBP-1 with PI3K/Akt signaling-controlled glycolysis and with Myc-regulated glutaminolysis to lipid metabolism. We also discuss the development of potential drugs targeting the SREBP-1-driven lipid metabolism as anti-cancer agents. PMID:23859617

Targeting and synergistic action of an antifungal peptide in an antibiotic drug-delivery system.

PubMed

Park, Seong-Cheol; Kim, Young-Min; Lee, Jong-Kook; Kim, Nam-Hong; Kim, Eun-Ji; Heo, Hun; Lee, Min-Young; Lee, Jung Ro; Jang, Mi-Kyeong

2017-06-28

Amphotericin B (AmB) has been widely used against fungal infections throughout almost the entire body, including the skin, nails, oral cavity, respiratory tract, and urinary tract. However, the development of AmB-loaded nanoparticles demands a novel technique that reduces its toxicity and other associated problems. Here, we developed a pH-responsive and redox-sensitive polymer-based AmB-delivery carrier system. In particular, this system was functionalized by conjugation with the antifungal peptide histatin 5, which acts both as a targeting ligand and a synergistic antifungal molecule against Candida albicans, a major systemic fungal pathogen of humans. Our results in vitro and in vivo suggest that this drug-delivery system may serve as a novel tool to facilitate the use of antimicrobial peptides as targeting ligands to pathogenic microbes, which would open new avenues of investigation in the field of drug delivery. Copyright © 2017 Elsevier B.V. All rights reserved.

Nesfatin-1-like peptide is a novel metabolic factor that suppresses feeding, and regulates whole-body energy homeostasis in male Wistar rats

PubMed Central

Gawli, Kavishankar; Ramesh, Naresh

2017-01-01

Nucleobindin-1 has high sequence similarity to nucleobindin-2, which encodes the anorectic and metabolic peptide, nesfatin-1. We previously reported a nesfatin-1-like peptide (NLP), anorectic in fish and insulinotropic in mice islet beta-like cells. The main objective of this research was to determine whether NLP is a metabolic regulator in male Wistar rats. A single intraperitoneal (IP) injection of NLP (100 μg/kg BW) decreased food intake and increased ambulatory movement, without causing any change in total activity or energy expenditure when compared to saline-treated rats. Continuous subcutaneous infusion of NLP (100 μg/kg BW) using osmotic mini-pumps for 7 days caused a reduction in food intake on days 3 and 4. Similarly, water intake was also reduced for two days (days 3 and 4) with the effect being observed during the dark phase. This was accompanied by an increased RER and energy expenditure. However, decreased whole-body fat oxidation, and total activity were observed during the long-term treatment (7 days). Body weight gain was not significantly different between control and NLP infused rats. The expression of mRNAs encoding adiponectin, resistin, ghrelin, cholecystokinin and uncoupling protein 1 (UCP1) were significantly upregulated, while leptin and peptide YY mRNA expression was downregulated in NLP-treated rats. These findings indicate that administration of NLP at 100 μg/kg BW reduces food intake and modulates whole body energy balance. In summary, NLP is a novel metabolic peptide in rats. PMID:28542568

Improving oral bioavailability of cyclic peptides by N-methylation.

PubMed

Räder, Andreas F B; Reichart, Florian; Weinmüller, Michael; Kessler, Horst

2018-06-01

The renaissance of peptides in pharmaceutical industry results from their importance in many biological functions. However, low metabolic stability and the lack of oral availability of most peptides is a certain limitation. Whereas metabolic instability may be often overcome by development of small cyclic peptides containing d-amino acids, the very low oral availability of most peptides is a serious limitation for some medicinal applications. The situation is complicated because a twofold optimization - biological activity and oral availability - is required to overcome this problem. Moreover, most simple "rules" for achieving oral availability are not general and are applicable only to limited cases. Many structural modifications for increasing biological activities and metabolic stabilities of cyclic peptides have been described, of which N-alkylation is probably the most common. This mini-review focuses on the effects of N-methylation of cyclic peptides in strategies to optimize bioavailabilities. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

The renin-angiotensin system: a target of and contributor to dyslipidemias, altered glucose homeostasis, and hypertension of the metabolic syndrome

PubMed Central

Putnam, Kelly; Shoemaker, Robin; Yiannikouris, Frederique

2012-01-01

The renin-angiotensin system (RAS) is an important therapeutic target in the treatment of hypertension. Obesity has emerged as a primary contributor to essential hypertension in the United States and clusters with other metabolic disorders (hyperglycemia, hypertension, high triglycerides, low HDL cholesterol) defined within the metabolic syndrome. In addition to hypertension, RAS blockade may also serve as an effective treatment strategy to control impaired glucose and insulin tolerance and dyslipidemias in patients with the metabolic syndrome. Hyperglycemia, insulin resistance, and/or specific cholesterol metabolites have been demonstrated to activate components required for the synthesis [angiotensinogen, renin, angiotensin-converting enzyme (ACE)], degradation (ACE2), or responsiveness (angiotensin II type 1 receptors, Mas receptors) to angiotensin peptides in cell types (e.g., pancreatic islet cells, adipocytes, macrophages) that mediate specific disorders of the metabolic syndrome. An activated local RAS in these cell types may contribute to dysregulated function by promoting oxidative stress, apoptosis, and inflammation. This review will discuss data demonstrating the regulation of components of the RAS by cholesterol and its metabolites, glucose, and/or insulin in cell types implicated in disorders of the metabolic syndrome. In addition, we discuss data supporting a role for an activated local RAS in dyslipidemias and glucose intolerance/insulin resistance and the development of hypertension in the metabolic syndrome. Identification of an activated RAS as a common thread contributing to several disorders of the metabolic syndrome makes the use of angiotensin receptor blockers and ACE inhibitors an intriguing and novel option for multisymptom treatment. PMID:22227126

Targeted delivery of non-viral vectors to cartilage in vivo using a chondrocyte-homing peptide identified by phage display.

PubMed

Pi, Yanbin; Zhang, Xin; Shi, Junjun; Zhu, Jinxian; Chen, Wenqing; Zhang, Chenguang; Gao, Weiwei; Zhou, Chunyan; Ao, Yingfang

2011-09-01

Gene therapy is a promising method for osteoarthritis and cartilage injury. However, specifically delivering target genes into chondrocytes is a great challenge because of their non-vascularity and the dense extracellular matrix of cartilage. In our study, we identified a chondrocyte-affinity peptide (CAP, DWRVIIPPRPSA) by phage display technology. Subsequent analysis suggests that the peptide can efficiently interact specifically with chondrocytes without any species specificity. Polyethylenimine (PEI) was covalently modified with CAP to construct a non-viral vector for cartilage-targeted therapy. To investigate the cartilage-targeting property of the CAP-modified vector, FITC-labeled CAP conjugated PEI/DNA particles were injected into rabbit knee joints, and visualized under confocal microscope. Higher concentrations of CAP-modified vector were detected in the cartilage and specifically taken up by chondrocytes compared with a randomly scrambled peptide (SP)-modified vector. To evaluate cartilage-targeting transfection efficiency, the GFP and luciferase genes were delivered into knee joints using CAP- and SP-modified PEI. Cartilage transfections mediated by CAP-modified PEI were much more efficient and specific than those by SP-modified PEI. This result suggests that CAP-modified PEI could be used as a specific cartilage-targeting vector for cartilage disorders. Copyright © 2011 Elsevier Ltd. All rights reserved.

Peptide vaccines and peptidomimetics targeting HER and VEGF proteins may offer a potentially new paradigm in cancer immunotherapy

PubMed Central

Kaumaya, Pravin TP; Foy, Kevin Chu

2013-01-01

The ErbB family (HER-1, HER-2, HER-3 and HER-4) of receptor tyrosine kinases has been the focus of cancer immunotherapeutic strategies while antiangiogenic therapies have focused on VEGF and its receptors VEGFR-1 and VEGFR-2. Agents targeting receptor tyrosine kinases in oncology include therapeutic antibodies to receptor tyrosine kinase ligands or the receptors themselves, and small-molecule inhibitors. Many of the US FDA-approved therapies targeting HER-2 and VEGF exhibit unacceptable toxicities, and show problems of efficacy, development of resistance and unacceptable safety profiles that continue to hamper their clinical progress. The combination of dif ferent peptide vaccines and peptidomimetics targeting specific molecular pathways that are dysregulated in tumors may potentiate anticancer immune responses, bypass immune tolerance and circumvent resistance mechanisms. The focus of this review is to discuss efforts in our laboratory spanning two decades of rationally developing peptide vaccines and therapeutics for breast cancer. This review highlights the prospective benefit of a new, untapped category of therapies biologically targeted to EGF receptor (HER-1), HER-2 and VEGF with potential peptide ‘blockbusters‘ that could lay the foundation of a new paradigm in cancer immunotherapy by creating clinical breakthroughs for safe and efficacious cancer cures. PMID:22894670

Design of ligand-targeted nanoparticles for enhanced cancer targeting

NASA Astrophysics Data System (ADS)

Stefanick, Jared F.

Ligand-targeted nanoparticles are increasingly used as drug delivery vehicles for cancer therapy, yet have not consistently produced successful clinical outcomes. Although these inconsistencies may arise from differences in disease models and target receptors, nanoparticle design parameters can significantly influence therapeutic efficacy. By employing a multifaceted synthetic strategy to prepare peptide-targeted nanoparticles with high purity, reproducibility, and precisely controlled stoichiometry of functionalities, this work evaluates the roles of polyethylene glycol (PEG) coating, ethylene glycol (EG) peptide-linker length, peptide hydrophilicity, peptide density, and nanoparticle size on tumor targeting in a systematic manner. These parameters were analyzed in multiple disease models by targeting human epidermal growth factor receptor 2 (HER2) in breast cancer and very late antigen-4 (VLA-4) in multiple myeloma to demonstrate the widespread applicability of this approach. By increasing the hydrophilicity of the targeting peptide sequence and simultaneously optimizing the EG peptide-linker length, the in vitro cellular uptake of targeted liposomes was significantly enhanced. Specifically, including a short oligolysine chain adjacent to the targeting peptide sequence effectively increased cellular uptake ~80-fold using an EG6 peptide-linker compared to ~10-fold using an EG45 linker. In vivo, targeted liposomes prepared in a traditional manner lacking the oligolysine chain demonstrated similar biodistribution and tumor uptake to non-targeted liposomes. However, by including the oligolysine chain, targeted liposomes using an EG45 linker significantly improved tumor uptake ~8-fold over non-targeted liposomes, while the use of an EG6 linker decreased tumor accumulation and uptake, owing to differences in cellular uptake kinetics, clearance mechanisms, and binding site barrier effects. To further improve tumor targeting and enhance the selectivity of targeted

Metabolic control of female puberty: potential therapeutic targets.

PubMed

Castellano, Juan M; Tena-Sempere, Manuel

2016-10-01

The onset of puberty in females is highly sensitive to the nutritional status and the amount of energy reserves of the organism. This metabolic information is sensed and transmitted to hypothalamic GnRH neurons, considered to be ultimately responsible for triggering puberty through the coordinated action of different peripheral hormones, central neurotransmitters, and molecular mediators. This article will review and discuss (i) the relevant actions of the adipose hormone leptin, as a stimulatory/permissive signal, and the gut hormone ghrelin, as an inhibitory factor, in the metabolic control of female puberty; (ii) the crucial role of the hypothalamic kisspeptin neurons, recently emerged as essential gatekeepers of puberty, in transmitting this metabolic information to GnRH neurons; and (iii) the potential involvement of key cellular energy sensors, such as mTOR, as molecular mediators in this setting. The thorough characterization of the physiological roles of the above elements in the metabolic control of female puberty, along with the discovery of novel factors, pathways, and mechanisms involved, will promote our understanding of the complex networks connecting metabolism and puberty and, ultimately, will aid in the design of target-specific treatments for female pubertal disorders linked to conditions of metabolic stress.

Targeting metabolic pathways for head and neck cancers therapeutics.

PubMed

Yamamoto, Masashi; Inohara, Hidenori; Nakagawa, Takashi

2017-09-01

Cancer cells have distinctive energy metabolism pathways that support their rapid cell division. The preference for anaerobic glycolysis under the normal oxygen condition is known as the Warburg effect and has been observed in head and neck cancers. These metabolic changes are controlled by cancer-related transcription factors, such as tumor suppressor gene and hypoxia inducible factor 1α. In addition, various metabolic enzymes also actively regulate cancer-specific metabolism including the switch between aerobic and anaerobic glycolysis. For a long time, these metabolic changes in cancer cells have been considered a consequence of transformation required to maintain the high rate of tumor cell replication. However, recent studies indicate that alteration of metabolism is sufficient to initiate tumor transformation. Indeed, oncogenic mutations in the metabolic enzymes, isocitrate dehydrogenase and succinate dehydrogenase, have been increasingly found in various cancers, including head and neck cancers. In the present review, we introduce recent findings regarding the cancer metabolism, including the molecular mechanisms of how they affect cancer pathogenesis and maintenance. We also discuss the current and future perspectives on therapeutics that target metabolic pathways, with an emphasis on head and neck cancer.

Stability of peptide drugs in the colon.

PubMed

Wang, Jie; Yadav, Vipul; Smart, Alice L; Tajiri, Shinichiro; Basit, Abdul W

2015-10-12

This study was the first to investigate the colonic stability of 17 peptide molecules (insulin, calcitonin, glucagon, secretin, somatostatin, desmopressin, oxytocin, Arg-vasopressin, octreotide, ciclosporin, leuprolide, nafarelin, buserelin, histrelin, [D-Ser(4)]-gonadorelin, deslorelin, and goserelin) in a model of the large intestine using mixed human faecal bacteria. Of these, the larger peptides - insulin, calcitonin, somatostatin, glucagon and secretin - were metabolized rapidly, with complete degradation observed within 5 min. In contrast, a number of the smaller peptides - Arg-vasopressin, desmopressin, oxytocin, gonadorelin, goserelin, buserelin, leuprolide, nafarelin and deslorelin - degraded more slowly, while octreotide, histrelin and ciclosporin were seen to be more stable as compared to the other small peptides under the same conditions. Peptide degradation rate was directly correlated to peptide lipophilicity (logP); those peptides with a higher logP were more stable in the colonic model (R(2)=0.94). In the absence of human faecal bacteria, all peptides were stable. This study highlights the impact of the colonic environment - in particular, the gut microbiota - on the metabolism of peptide drugs, and identifies potential peptide candidates for drug delivery to the colon. Copyright © 2015 Elsevier B.V. All rights reserved.

Ligand-regulated peptides: a general approach for modulating protein-peptide interactions with small molecules.

PubMed

Binkowski, Brock F; Miller, Russell A; Belshaw, Peter J

2005-07-01

We engineered a novel ligand-regulated peptide (LiRP) system where the binding activity of intracellular peptides is controlled by a cell-permeable small molecule. In the absence of ligand, peptides expressed as fusions in an FKBP-peptide-FRB-GST LiRP scaffold protein are free to interact with target proteins. In the presence of the ligand rapamycin, or the nonimmunosuppressive rapamycin derivative AP23102, the scaffold protein undergoes a conformational change that prevents the interaction of the peptide with the target protein. The modular design of the scaffold enables the creation of LiRPs through rational design or selection from combinatorial peptide libraries. Using these methods, we identified LiRPs that interact with three independent targets: retinoblastoma protein, c-Src, and the AMP-activated protein kinase. The LiRP system should provide a general method to temporally and spatially regulate protein function in cells and organisms.

Identification of the Consistently Altered Metabolic Targets in Human Hepatocellular Carcinoma.

PubMed

Nwosu, Zeribe Chike; Megger, Dominik Andre; Hammad, Seddik; Sitek, Barbara; Roessler, Stephanie; Ebert, Matthias Philip; Meyer, Christoph; Dooley, Steven

2017-09-01

Cancer cells rely on metabolic alterations to enhance proliferation and survival. Metabolic gene alterations that repeatedly occur in liver cancer are largely unknown. We aimed to identify metabolic genes that are consistently deregulated, and are of potential clinical significance in human hepatocellular carcinoma (HCC). We studied the expression of 2,761 metabolic genes in 8 microarray datasets comprising 521 human HCC tissues. Genes exclusively up-regulated or down-regulated in 6 or more datasets were defined as consistently deregulated. The consistent genes that correlated with tumor progression markers ( ECM2 and MMP9) (Pearson correlation P < .05) were used for Kaplan-Meier overall survival analysis in a patient cohort. We further compared proteomic expression of metabolic genes in 19 tumors vs adjacent normal liver tissues. We identified 634 consistent metabolic genes, ∼60% of which are not yet described in HCC. The down-regulated genes (n = 350) are mostly involved in physiologic hepatocyte metabolic functions (eg, xenobiotic, fatty acid, and amino acid metabolism). In contrast, among consistently up-regulated metabolic genes (n = 284) are those involved in glycolysis, pentose phosphate pathway, nucleotide biosynthesis, tricarboxylic acid cycle, oxidative phosphorylation, proton transport, membrane lipid, and glycan metabolism. Several metabolic genes (n = 434) correlated with progression markers, and of these, 201 predicted overall survival outcome in the patient cohort analyzed. Over 90% of the metabolic targets significantly altered at the protein level were similarly up- or down-regulated as in genomic profile. We provide the first exposition of the consistently altered metabolic genes in HCC and show that these genes are potentially relevant targets for onward studies in preclinical and clinical contexts.

Antiviral Peptides Targeting the West Nile Virus Envelope Protein▿

PubMed Central

Bai, Fengwei; Town, Terrence; Pradhan, Deepti; Cox, Jonathan; Ashish; Ledizet, Michel; Anderson, John F.; Flavell, Richard A.; Krueger, Joanna K.; Koski, Raymond A.; Fikrig, Erol

2007-01-01

West Nile virus (WNV) can cause fatal murine and human encephalitis. The viral envelope protein interacts with host cells. A murine brain cDNA phage display library was therefore probed with WNV envelope protein, resulting in the identification of several adherent peptides. Of these, peptide 1 prevented WNV infection in vitro with a 50% inhibition concentration of 67 μM and also inhibited infection of a related flavivirus, dengue virus. Peptide 9, a derivative of peptide 1, was a particularly potent inhibitor of WNV in vitro, with a 50% inhibition concentration of 2.6 μM. Moreover, mice challenged with WNV that had been incubated with peptide 9 had reduced viremia and fatality compared with control animals. Peptide 9 penetrated the murine blood-brain barrier and was found in the brain parenchyma, implying that it may have antiviral activity in the central nervous system. These short peptides serve as the basis for developing new therapeutics for West Nile encephalitis and, potentially, other flaviviruses. PMID:17151121

Novel tumor-targeted RGD peptide-camptothecin conjugates: synthesis and biological evaluation.

PubMed

Dal Pozzo, Alma; Ni, Ming-Hong; Esposito, Emiliano; Dallavalle, Sabrina; Musso, Loana; Bargiotti, Alberto; Pisano, Claudio; Vesci, Loredana; Bucci, Federica; Castorina, Massimo; Foderà, Rosanna; Giannini, Giuseppe; Aulicino, Concetta; Penco, Sergio

2010-01-01

Five RGD peptide-camptothecin (CPT) conjugates were designed and synthesized with the purpose to improve the therapeutic index of this antitumoral drug family. New RGD cyclopeptides were selected on the basis of their high affinity to alpha(v) integrin receptors overexpressed by tumor cells and their metabolic stability. The conjugates can be divided in two groups: in the first the peptide was attached to the drug through an amide bond, in the second through a hydrazone bond. The main difference between the two spacers lies in their acid stability. Affinity to the receptors was maintained for all conjugates and their internalization into tumor cells was demonstrated. The first group conjugates showed lower in vitro and in vivo activity than the parent drug, probably due to the excessive stability of the amide bond, even inside the tumor cells. Conversely, the hydrazone conjugates exhibited in vitro tumor cell inhibition similar to the parent drug, indicating high conversion in the culture medium and/or inside the cells, but their poor solubility hampered in vivo experiments. On the basis of these results, information was acquired for additional development of derivatives with different linkers and better solubility for in vivo evaluation. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Ligand-regulated peptide aptamers.

PubMed

Miller, Russell A

2009-01-01

The peptide aptamer approach employs high-throughput selection to identify members of a randomized peptide library displayed from a scaffold protein by virtue of their interaction with a target molecule. Extending this approach, we have developed a peptide aptamer scaffold protein that can impart small-molecule control over the aptamer-target interaction. This ligand-regulated peptide (LiRP) scaffold, consisting of the protein domains FKBP12, FRB, and GST, binds to the cell-permeable small-molecule rapamycin and the binding of this molecule can prevent the interaction of the randomizable linker region connecting FKBP12 with FRB. Here we present a detailed protocol for the creation of a peptide aptamer plasmid library, selection of peptide aptamers using the LiRP scaffold in a yeast two-hybrid system, and the screening of those peptide aptamers for a ligand-regulated interaction.

Nanocarrier possibilities for functional targeting of bioactive peptides and proteins: state-of-the-art.

PubMed

Moutinho, Carla G; Matos, Carla M; Teixeira, José A; Balcão, Victor M

2012-02-01

This review attempts to provide an updated compilation of studies reported in the literature pertaining to production of nanocarriers encasing peptides and/or proteins, in a way that helps the reader direct a bibliographic search and develop an integrated perspective of the subject. Highlights are given to bioactive proteins and peptides, with a special focus on those from dairy sources (including physicochemical characteristics and properties, and biopharmaceutical application possibilities of e.g. lactoferrin and glycomacropeptide), as well as to nanocarrier functional targeting. Features associated with micro- and (multiple) nanoemulsions, micellar systems, liposomes and solid lipid nanoparticles, together with biopharmaceutical considerations, are presented in the text in a systematic fashion.

Targeting Metabolic Plasticity in Breast Cancer Cells via Mitochondrial Complex I Modulation

PubMed Central

Xu, Qijin; Biener-Ramanujan, Eva; Yang, Wei; Ramanujan, V Krishnan

2016-01-01

Purpose Heterogeneity commonly observed in clinical tumors stems both from the genetic diversity as well as from the differential metabolic adaptation of multiple cancer types during their struggle to maintain uncontrolled proliferation and invasion in vivo. This study aims to identify a potential metabolic window of such adaptation in aggressive human breast cancer cell lines. Methods With a multidisciplinary approach using high resolution imaging, cell metabolism assays, proteomic profiling and animal models of human tumor xenografts and via clinically-relevant, pharmacological approach for modulating mitochondrial complex I function in human breast cancer cell lines, we report a novel route to target metabolic plasticity in human breast cancer cells. Results By a systematic modulation of mitochondrial function and by mitigating metabolic switch phenotype in aggressive human breast cancer cells, we demonstrate that the resulting metabolic adaptation signatures can predictably decrease tumorigenic potential in vivo. Proteomic profiling of the metabolic adaptation in these cells further revealed novel protein-pathway interactograms highlighting the importance of antioxidant machinery in the observed metabolic adaptation. Conclusions Improved metabolic adaptation potential in aggressive human breast cancer cells contribute to improving mitochondrial function and reducing metabolic switch phenotype –which may be vital for targeting primary tumor growth in vivo. PMID:25677747

Peptide-modified liposomes for selective targeting of bombesin receptors overexpressed by cancer cells: a potential theranostic agent

PubMed Central

Accardo, Antonella; Salsano, Giuseppina; Morisco, Anna; Aurilio, Michela; Parisi, Antonio; Maione, Francesco; Cicala, Carla; Tesauro, Diego; Aloj, Luigi; De Rosa, Giuseppe; Morelli, Giancarlo

2012-01-01

Objectives Drug delivery systems consisting of liposomes displaying a cell surface receptor-targeting peptide are being developed to specifically deliver chemotherapeutic drugs to tumors overexpressing a target receptor. This study addresses novel liposome composition approaches to specifically target tissues overexpressing bombesin (BN) receptors. Methods A new amphiphilic peptide derivative (MonY-BN) containing the BN(7–14) peptide, the DTPA (diethylenetriaminepentaacetate) chelating agent, a hydrophobic moiety with two C18 alkyl chains, and polyethylene glycol spacers, has been synthesized by solid-phase methods. Liposomes have been generated by co-aggregation of MonY-BN with 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC). The structural and biological properties of these new target-selective drug-delivery systems have been characterized. Results Liposomes with a DSPC/MonY-BN (97/3 molar ratio) composition showed a diameter of 145.5 ± 31.5 nm and a polydispersity index of 0.20 ± 0.05. High doxorubicin (Dox) loading was obtained with the remote pH gradient method using citrate as the inner buffer. Specific binding to PC-3 cells of DSPC/MonY-BN liposomes was obtained (2.7% ± 0.3%, at 37°C), compared with peptide-free DSPC liposomes (1.4% ± 0.2% at 37°C). Incubation of cells with DSPC/ MonY-BN/Dox showed significantly lower cell survival compared with DSPC/Dox-treated cells, in the presence of 100 ng/mL and 300 ng/mL drug amounts, in cytotoxicity experiments. Intravenous treatment of PC-3 xenograft-bearing mice with DSPC/MonY-BN/Dox at 10 mg/kg Dox dose produced higher tumour growth inhibition (60%) compared with nonspecific DSPC/ Dox liposomes (36%) relative to control animals. Conclusion The structural and loading properties of DSPC/MonY-BN liposomes along with the observed in-vitro and in-vivo activity are encouraging for further development of this approach for target-specific cancer chemotherapy. PMID:22619538

Miklós Bodanszky Award Lecture: Advances in the selective targeting of protein phosphatase-1 and phosphatase-2A with peptides.

PubMed

Köhn, Maja

2017-10-01

Protein phosphatase-1 and phosphatase-2A are two ubiquitously expressed enzymes known to catalyze the majority of dephosphorylation reactions on serine and threonine inside cells. They play roles in most cellular processes and are tightly regulated by regulatory subunits in holoenzymes. Their misregulation and malfunction contribute to disease development and progression, such as in cancer, diabetes, viral infections, and neurological as well as heart diseases. Therefore, targeting these phosphatases for therapeutic use would be highly desirable; however, their complex regulation and high conservation of the active site have been major hurdles for selectively targeting them in the past. In the last decade, new approaches have been developed to overcome these hurdles and have strongly revived the field. I will focus here on peptide-based approaches, which contributed to showing that these phosphatases can be targeted selectively and aided in rethinking the design of selective phosphatase modulators. Finally, I will give a perspective on www.depod.org, the human dephosphorylation database, and how it can aid phosphatase modulator design. © 2017 The Authors. Journal of Peptide Science published by European Peptide Society and John Wiley & Sons Ltd. © 2017 The Authors. Journal of Peptide Science published by European Peptide Society and John Wiley & Sons Ltd.

Two birds, one stone: dual targeting of the cancer cell surface and subcellular mitochondria by the galectin-3-binding peptide G3-C12

PubMed Central

Sun, Wei; Li, Lian; Li, Li-jia; Yang, Qing-qing; Zhang, Zhi-rong; Huang, Yuan

2017-01-01

Active tumor-targeting approaches using specific ligands have drawn considerable attention over the years. However, a single ligand often fails to simultaneously target the cancer cell surface and subcellular organelles, which limits the maximum therapeutic efficacy of delivered drugs. We describe a polymeric delivery system modified with the G3-C12 peptide for sequential dual targeting. In this study, galectin-3-targeted G3-C12 peptide was conjugated onto the N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer for the delivery of D(KLAKLAK)2 (KLA) peptide. G3-C12-HPMA-KLA exhibited increased receptor-mediated internalization into galectin-3-overexpressing PC-3 cells. Furthermore, G3-C12 peptide also directed HPMA-KLA conjugates to mitochondria. This occurred because the apoptosis signal triggered the accumulation of galectin-3 in mitochondria, and the G3-C12 peptide that specifically bound to galectin-3 was trafficked along with its receptor intracellularly. As a result, G3-C12-HPMA-KLA disrupted the mitochondrial membrane, increased the generation of reactive oxygen species (ROS) and induced cytochrome c release, which ultimately resulted in enhanced cytotoxicity. An in vivo study revealed that the G3-C12 peptide significantly enhanced the tumor accumulation of the KLA conjugate. In addition, G3-C12-HPMA-KLA exhibited the best therapeutic efficacy and greatly improved the animal survival rate. Our work demonstrates that G3-C12 is a promising ligand with dual-targeting functionality. PMID:28065935

PET/PDT theranostics: synthesis and biological evaluation of a peptide-targeted gallium porphyrin.

PubMed

Bryden, Francesca; Savoie, Huguette; Rosca, Elena V; Boyle, Ross W

2015-03-21

The development of novel theranostic agents is an important step in the pathway towards personalised medicine, with the combination of diagnostic and therapeutic modalities into a single treatment agent naturally lending itself to the optimisation and personalisation of treatment. In pursuit of the goal of a molecular theranostic suitable for use as a PET radiotracer and a photosensitiser for PDT, a novel radiolabelled peptide-porphyrin conjugate targeting the α6β1-integrin has been developed. (69/71)Ga and (68)Ga labelling of an azide-functionalised porphyrin has been carried out in excellent yields, with subsequent bioconjugation to an alkyne-functionalised peptide demonstrated. α6β1-integrin expression of two cell lines has been evaluated by flow cytometry, and therapeutic potential of the conjugate demonstrated. Evaluation of the phototoxicity of the porphyrin-peptide theranostic conjugate in comparison to an untargeted control porphyrin in vitro, demonstrated significantly enhanced activity for a cell line with higher α6β1-integrin expression when compared with a cell line exhibiting lower α6β1-integrin expression.

Optimization and in Vivo Validation of Peptide Vectors Targeting the LDL Receptor.

PubMed

Jacquot, Guillaume; Lécorché, Pascaline; Malcor, Jean-Daniel; Laurencin, Mathieu; Smirnova, Maria; Varini, Karine; Malicet, Cédric; Gassiot, Fanny; Abouzid, Karima; Faucon, Aude; David, Marion; Gaudin, Nicolas; Masse, Maxime; Ferracci, Géraldine; Dive, Vincent; Cisternino, Salvatore; Khrestchatisky, Michel

2016-12-05

Active targeting and delivery to pathophysiological organs of interest is of paramount importance to increase specific accumulation of therapeutic drugs or imaging agents while avoiding systemic side effects. We recently developed a family of new peptide ligands of the human and rodent LDL receptor (LDLR), an attractive cell-surface receptor with high uptake activity and local enrichment in several normal or pathological tissues (Malcor et al., J. Med. Chem. 2012, 55 (5), 2227). Initial chemical optimization of the 15-mer, all natural amino acid compound 1/VH411 (DSGL[CMPRLRGC] c DPR) and structure-activity relationship (SAR) investigation led to the cyclic 8 amino acid analogue compound 22/VH445 ([cMPRLRGC] c ) which specifically binds hLDLR with a K D of 76 nM and has an in vitro blood half-life of ∼3 h. Further introduction of non-natural amino acids led to the identification of compound 60/VH4106 ([(d)-"Pen"M"Thz"RLRGC] c ), which showed the highest K D value of 9 nM. However, this latter analogue displayed the lowest in vitro blood half-life (∼1.9 h). In the present study, we designed a new set of peptide analogues, namely, VH4127 to VH4131, with further improved biological properties. Detailed analysis of the hLDLR-binding kinetics of previous and new analogues showed that the latter all displayed very high on-rates, in the 10 6 s -1. M -1 range, and off-rates varying from the low 10 -2 s -1 to the 10 -1 s -1 range. Furthermore, all these new analogues showed increased blood half-lives in vitro, reaching ∼7 and 10 h for VH4129 and VH4131, respectively. Interestingly, we demonstrate in cell-based assays using both VH445 and the most balanced optimized analogue VH4127 ([cM"Thz"RLRG"Pen"] c ), showing a K D of 18 nM and a blood half-life of ∼4.3 h, that its higher on-rate correlated with a significant increase in both the extent of cell-surface binding to hLDLR and the endocytosis potential. Finally, intravenous injection of tritium-radiolabeled 3 H

New trends in the development of opioid peptide analogues as advanced remedies for pain relief.

PubMed

Gentilucci, Luca

2004-01-01

The search for new peptides to be used as analgesics in place of morphine has been mainly directed to develop peptide analogues or peptidomimetics having higher biological stability and receptor selectivity. Indeed, most of the alkaloid opioid counterindications are due to the scarce stability and the contemporary activation of different receptor types. However, the development of several extremely stable and selective peptide ligands for the different opioid receptors, and the recent discovery of the micro-receptor selective endomorphins, rendered this search less fundamental. In recent years, other opioid peptide properties have been investigated in the search for new pharmacological tools. The utility of a drug depends on its ability to reach appropriate receptors at the target tissue and to remain metabolically stable in order to produce the desired effect. This review deals with the recent investigations on peptide bioavailability, in particular barrier penetration and resistance against enzymatic degradation; with the development of peptides having activity at different receptors; with chimeric peptides, with propeptides, and with non-conventional peptides, lacking basic pharmacophoric features.

Liver carbohydrates metabolism: A new islet-neogenesis associated protein peptide (INGAP-PP) target.

PubMed

Villagarcía, Hernán Gonzalo; Román, Carolina Lisi; Castro, María Cecilia; González, Luisa Arbeláez; Ronco, María Teresa; Francés, Daniel Eleazar; Massa, María Laura; Maiztegui, Bárbara; Flores, Luis Emilio; Gagliardino, Juan José; Francini, Flavio

2018-03-01

Islet-Neogenesis Associated Protein-Pentadecapeptide (INGAP-PP) increases β-cell mass and enhances glucose and amino acids-induced insulin secretion. Our aim was to demonstrate its effect on liver metabolism. For that purpose, adult male Wistar rats were injected twice-daily (10 days) with saline solution or INGAP-PP (250 μg). Thereafter, serum glucose, triglyceride and insulin levels were measured and homeostasis model assessment (HOMA-IR) and hepatic insulin sensitivity (HIS) were determined. Liver glucokinase and glucose-6-phosphatase (G-6-Pase) expression and activity, phosphoenolpyruvate carboxykinase (PEPCK) expression, phosphofructokinase-2 (PFK-2) protein content, P-Akt/Akt and glycogen synthase kinase-3β (P-GSK3/GSK3) protein ratios and glycogen deposit were also determined. Additionally, glucokinase activity and G-6-Pase and PEPCK gene expression were also determined in isolated hepatocytes from normal rats incubated with INGAP-PP (5 μg/ml). INGAP-PP administration did not modify any of the serum parameters tested but significantly increased activity of liver glucokinase and the protein level of its cytosolic activator, PFK-2. Conversely, INGAP-PP treated rats decreased gene expression and enzyme activity of gluconeogenic enzymes, G-6-Pase and PEPCK. They also showed a higher glycogen deposit and P-GSK3/GSK3 and P-Akt/Akt ratio. In isolated hepatocytes, INGAP-PP increased GK activity and decreased G-6-Pase and PEPCK expression. These results demonstrate a direct effect of INGAP-PP on the liver acting through P-Akt signaling pathway. INGAP-PP enhances liver glucose metabolism and deposit and reduces its production/output, thereby contributing to maintain normal glucose homeostasis. These results reinforce the concept that INGAP-PP might become a useful tool to treat people with impaired islet/liver glucose metabolism as it occurs in T2D. Copyright © 2018 Elsevier Inc. All rights reserved.

MRM validation of targeted nonglycosylated peptides from N-glycoprotein biomarkers using direct trypsin digestion of undepleted human plasma.

PubMed

Lee, Ju Yeon; Kim, Jin Young; Cheon, Mi Hee; Park, Gun Wook; Ahn, Yeong Hee; Moon, Myeong Hee; Yoo, Jong Shin

2014-02-26

A rapid, simple, and reproducible MRM-based validation method for serological glycoprotein biomarkers in clinical use was developed by targeting the nonglycosylated tryptic peptides adjacent to N-glycosylation sites. Since changes in protein glycosylation are known to be associated with a variety of diseases, glycoproteins have been major targets in biomarker discovery. We previously found that nonglycosylated tryptic peptides adjacent to N-glycosylation sites differed in concentration between normal and hepatocellular carcinoma (HCC) plasma due to differences in steric hindrance of the glycan moiety in N-glycoproteins to tryptic digestion (Lee et al., 2011). To increase the feasibility and applicability of clinical validation of biomarker candidates (nonglycosylated tryptic peptides), we developed a method to effectively monitor nonglycosylated tryptic peptides from a large number of plasma samples and to reduce the total analysis time with maximizing the effect of steric hindrance by the glycans during digestion of glycoproteins. The AUC values of targeted nonglycosylated tryptic peptides were excellent (0.955 for GQYCYELDEK, 0.880 for FEDGVLDPDYPR and 0.907 for TEDTIFLR), indicating that these could be effective biomarkers for hepatocellular carcinoma. This method provides the necessary throughput required to validate glycoprotein biomarkers, as well as quantitative accuracy for human plasma analysis, and should be amenable to clinical use. Difficulties in verifying and validating putative protein biomarkers are often caused by complex sample preparation procedures required to determine their concentrations in a large number of plasma samples. To solve the difficulties, we developed MRM-based protein biomarker assays that greatly reduce complex, time-consuming, and less reproducible sample pretreatment steps in plasma for clinical implementation. First, we used undepleted human plasma samples without any enrichment procedures. Using nanoLC/MS/MS, we targeted

Epitope-based peptide vaccine design and target site depiction against Ebola viruses: an immunoinformatics study.

PubMed

Khan, M A; Hossain, M U; Rakib-Uz-Zaman, S M; Morshed, M N

2015-07-01

Ebola viruses (EBOVs) have been identified as an emerging threat in recent year as it causes severe haemorrhagic fever in human. Epitope-based vaccine design for EBOVs remains a top priority because a mere progress has been made in this regard. Another reason is the lack of antiviral drug and licensed vaccine although there is a severe outbreak in Central Africa. In this study, we aimed to design an epitope-based vaccine that can trigger a significant immune response as well as to prognosticate inhibitor that can bind with potential drug target sites using various immunoinformatics and docking simulation tools. The capacity to induce both humoral and cell-mediated immunity by T cell and B cell was checked for the selected protein. The peptide region spanning 9 amino acids from 42 to 50 and the sequence TLASIGTAF were found as the most potential B and T cell epitopes, respectively. This peptide could interact with 12 HLAs and showed high population coverage up to 80.99%. Using molecular docking, the epitope was further appraised for binding against HLA molecules to verify the binding cleft interaction. In addition with this, the allergenicity of the epitopes was also evaluated. In the post-therapeutic strategy, docking study of predicted 3D structure identified suitable therapeutic inhibitor against targeted protein. However, this computational epitope-based peptide vaccine designing and target site prediction against EBOVs open up a new horizon which may be the prospective way in Ebola viruses research; the results require validation by in vitro and in vivo experiments. © 2015 John Wiley & Sons Ltd.

A Reexamination of Active and Passive Tumor Targeting by Using Rod-Shaped Gold Nanocrystals and Covalently Conjugated Peptide Ligands

PubMed Central

Huang, Xiaohua; Peng, Xianghong; Wang, Yiqing; Wang, Yuxiang; Shin, Dong M.; El-Sayed, Mostafa A.; Nie, Shuming

2010-01-01

The targeted delivery of nanoparticles to solid tumors is one of the most important and challenging problems in cancer nanomedicine, but the detailed delivery mechanisms and design principles are still not well understood. Here we report quantitative tumor uptake studies for a class of elongated gold nanocrystals (called nanorods) that are covalently conjugated to tumor-targeting peptides. A major advantage in using gold as a “tracer” is that the accumulated gold in tumors and other organs can be quantitatively determined by elemental mass spectrometry (gold is not a natural element found in animals). Thus, colloidal gold nanorods are stabilized with a layer of polyethylene glycols (PEGs), and are conjugated to three different ligands: (i) a single-chain variable fragment (ScFv) peptide that recognizes the epidermal growth factor receptor (EGFR); (ii) an amino terminal fragment (ATF) peptide that recognizes the urokinase plasminogen activator receptor (uPAR); and (iii) a cyclic RGD peptide that recognizes the avb3 integrin receptor. Quantitative pharmacokinetic and biodistribution data show that these targeting ligands only marginally improve the total gold accumulation in xenograft tumor models in comparison with nontargeted controls, but their use could greatly alter the intracellular and extracellular nanoparticle distributions. When the gold nanorods are administered via intravenous injection, we also find that active molecular targeting of the tumor microenvironments (e.g., fibroblasts, macrophages, and vasculatures) does not significantly influence the tumor nanoparticle uptake. These results suggest that for photothermal cancer therapy, the preferred route of gold nanorod administration is intra-tumoral injection instead of intravenous injection. PMID:20863096

PNC27 anticancer peptide as targeting ligand significantly improved antitumor efficacy of Doxil in HDM2-expressing cells.

PubMed

Darban, Shahrzad Amiri; Badiee, Ali; Jaafari, Mahmoud Reza

2017-06-01

To investigate the potential of PNC27 peptide, 12-26 of p53 with high affinity for HDM2 protein, as targeting ligand for Doxil to improve its antitumor activity. Doxil postinserted with 25, 50, 100 and 200 PNC27 peptides per liposome. Flow cytometry and confocal analysis were performed on C26 colon carcinoma (HDM2 positive) and B16F0 melanoma (HDM2 negative) cells. In vivo studies were performed on BALB/c mice bearing C26 and C57BL/6 mice bearing B16F0 tumor models. PNC27-Doxil showed significant cellular uptake and cytotoxicity in C26 cells compared with Doxil. PNC27-Doxil (100 PNC27 peptide) significantly improved therapeutic efficacy of Doxil without compromising its biodistribution in C26 tumor. However, these results were not observed in B16F0 cells. PNC27 is a promising targeting ligand for Doxil against HDM2-positive cancers.

Protective effect of C-peptide on experimentally induced diabetic nephropathy and the possible link between C-peptide and nitric oxide.

PubMed

Elbassuoni, Eman A; Aziz, Neven M; El-Tahawy, Nashwa F

2018-06-01

Diabetic nephropathy one of the major microvascular diabetic complications. Besides hyperglycemia, other factors contribute to the development of diabetic complications as the proinsulin connecting peptide, C-peptide. We described the role of C-peptide replacement therapy on experimentally induced diabetic nephropathy, and its potential mechanisms of action by studying the role of nitric oxide (NO) as a mediator of C-peptide effects by in vivo modulating its production by N G -nitro-l-arginine methyl ester (L-NAME). Renal injury markers measured were serum urea, creatinine, tumor necrosis factor alpha, and angiotensin II, and malondialdehyde, total antioxidant, Bcl-2, and NO in renal tissue. In conclusion, diabetic induction resulted in islet degenerations and decreased insulin secretion with its metabolic consequences and subsequent renal complications. C-Peptide deficiencies in diabetes might have contributed to the metabolic and renal error, since C-peptide treatment to the diabetic rats completely corrected these errors. The beneficial effects of C-peptide are partially antagonized by L-NAME coadministration, indicating that NO partially mediates C-peptide effects.

Anti-diabetic potential of peptides: Future prospects as therapeutic agents.

PubMed

Marya; Khan, Haroon; Nabavi, Seyed Mohammad; Habtemariam, Solomon

2018-01-15

Diabetes mellitus is a metabolic disorder in which the glucose level in blood exceeds beyond the normal level. Persistent hyperglycemia leads to diabetes late complication and obviously account for a large number of morbidity and mortality worldwide. Numerous therapeutic options are available for the treatment of diabetes including insulin for type I and oral tablets for type II, but its effective management is still a dream. To date, several options are under investigation in various research laboratories for efficacious and safer agents. Of them, peptides are currently amongst the most widely investigated potential therapeutic agents whose design and optimal uses are under development. A number of natural and synthetic peptides have so far been found with outstanding antidiabetic effect mediated through diverse mechanisms. The applications of new emerging techniques and drug delivery systems further offer opportunities to achieve the desired target outcomes. Some outstanding peptides in preclinical and clinical studies with better efficacy and safety profile have already been identified. Further detail studies on these peptides may therefore lead to significant clinically useful antidiabetic agents. Copyright © 2017. Published by Elsevier Inc.

An improved 99mTc-HYNIC-(Ser)3-LTVSPWY peptide with EDDA/tricine as co-ligands for targeting and imaging of HER2 overexpression tumor.

PubMed

Khodadust, Fatemeh; Ahmadpour, Sajjad; Aligholikhamseh, Nazan; Abedi, Seyed Mohammad; Hosseinimehr, Seyed Jalal

2018-01-20

Overexpression of human epidermal receptor 2 (HER2) has given the opportunity for targeting and delivering of imaging radiotracers. The aim of this study was to evaluate the 99m Tc-HYNIC-(EDDA/tricine)-(Ser) 3 -LTVSPWY peptide for tumor targeting and imaging of tumor with overexpression of HER2. The HYNIC-(Ser) 3 -LTVSPWY was labeled with 99m Tc in presence of EDDA/tricine mixture as co-ligands. The in vitro and in vivo studies of this radiolabeled peptide were performed for cellular specific binding and tumor targeting. The high radiochemical purity of 99m Tc-HYNIC (EDDA/tricine)-(Ser) 3 -LTVSPWY was obtained to be 99%. It exhibited high stability in normal saline and human serum. In HER2 binding affinity study, a significant reduction in uptake of radiolabeled peptide (7.7 fold) was observed by blocking SKOV-3 cells receptors with unlabeled peptide. The K D and B max values for this radiolabeled peptide were determined as 3.3 ± 1.0 nM and 2.9 ± 0.3 × 10 6 CPM/pMol, respectively. Biodistribution study revealed tumor to blood and tumor to muscle ratios about 6.9 and 4 respectively after 4 h. Tumor imaging by gamma camera demonstrated considerable high contrast tumor uptake. This developed 99m Tc-HYNIC-(Ser) 3 -LTVSPWY peptide selectively targeted on HER2 tumor and exhibited a high target uptake combined with acceptable low background activity for tumor imaging in mice. The results of this study and its comparison with another study showed that 99m Tc-HYNIC-(EDDA/tricine)-(Ser) 3 -LTVSPWY is much better than previously reported radiolabeled peptide as 99m Tc-CSSS-LTVSPWY for HER2 overexpression tumor targeting and imaging. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

A novel vascular-targeting peptide for gastric cancer delivers low-dose TNFα to normalize the blood vessels and improve the anti-cancer efficiency of 5-fluorouracil.

PubMed

Lu, Lan; Li, Zhi Jie; Li, Long Fei; Shen, Jing; Zhang, Lin; Li, Ming Xing; Xiao, Zhan Gang; Wang, Jian Hao; Cho, Chi Hin

2017-11-01

Various vascular-targeted agents fused with tumor necrosis factor α (TNFα) have been shown to improve drug absorption into tumor tissues and enhance tumor vascular function. TCP-1 is a peptide selected through in vivo phage library biopanning against a mouse orthotopic colorectal cancer model and is a promising agent for drug delivery. This study further investigated the targeting ability of TCP-1 phage and peptide to blood vessels in an orthotopic gastric cancer model in mice and assessed the synergistic anti-cancer effect of 5-fluorouracil (5-FU) with subnanogram TNFα targeted delivered by TCP-1 peptide. In vivo phage targeting assay and in vivo colocalization analysis were carried out to test the targeting ability of TCP-1 phage/peptide. A targeted therapy for improvement of the therapeutic efficacy of 5-FU and vascular function was performed through administration of TCP-1/TNFα fusion protein in this model. TCP-1 phage exhibited strong homing ability to the orthotopic gastric cancer after phage injection. Immunohistochemical staining suggested that and TCP-1 phage/TCP-1 peptide could colocalize with tumor vascular endothelial cells. TCP-1/TNFα combined with 5-FU was found to synergistically inhibit tumor growth, induce apoptosis and reduce cell proliferation without evident toxicity. Simultaneously, subnanogram TCP-1/TNFα treatment normalized tumor blood vessels. Targeted delivery of low-dose TNFα by TCP-1 peptide can potentially modulate the vascular function of gastric cancer and increase the drug delivery of chemotherapeutic drugs. Copyright © 2017. Published by Elsevier Inc.

A peptide for targeted, systemic delivery of imaging and therapeutic compounds into acute brain injuries

NASA Astrophysics Data System (ADS)

Mann, Aman P.; Scodeller, Pablo; Hussain, Sazid; Joo, Jinmyoung; Kwon, Ester; Braun, Gary B.; Mölder, Tarmo; She, Zhi-Gang; Kotamraju, Venkata Ramana; Ranscht, Barbara; Krajewski, Stan; Teesalu, Tambet; Bhatia, Sangeeta; Sailor, Michael J.; Ruoslahti, Erkki

2016-06-01

Traumatic brain injury (TBI) is a major health and socio-economic problem, but no pharmacological agent is currently approved for the treatment of acute TBI. Thus, there is a great need for advances in this field. Here, we describe a short peptide (sequence CAQK) identified by in vivo phage display screening in mice with acute brain injury. The CAQK peptide selectively binds to injured mouse and human brain, and systemically injected CAQK specifically homes to sites of brain injury in mouse models. The CAQK target is a proteoglycan complex upregulated in brain injuries. Coupling to CAQK increased injury site accumulation of systemically administered molecules ranging from a drug-sized molecule to nanoparticles. CAQK-coated nanoparticles containing silencing oligonucleotides provided the first evidence of gene silencing in injured brain parenchyma by systemically administered siRNA. These findings present an effective targeting strategy for the delivery of therapeutics in clinical management of acute brain injuries.

Gut Microbiota as a Therapeutic Target for Metabolic Disorders.

PubMed

Okubo, Hirofumi; Nakatsu, Yusuke; Kushiyama, Akifumi; Yamamotoya, Takeshi; Matsunaga, Yasuka; Inoue, Masa-Ki; Fujishiro, Midori; Sakoda, Hideaki; Ohno, Haruya; Yoneda, Masayasu; Ono, Hiraku; Asano, Tomoichiro

2018-01-01

Gut microbiota play a vital role not only in the digestion and absorption of nutrients, but also in homeostatic maintenance of host immunity, metabolism and the gut barrier. Recent evidence suggests that gut microbiota alterations contribute to the pathogenesis of metabolic disorders. In this review, we discuss the association between the gut microbiota and metabolic disorders, such as obesity, type 2 diabetes mellitus and non-alcoholic fatty liver disease, and the contribution of relevant modulating interventions, focusing on recent human studies. Several studies have identified potential causal associations between gut microbiota and metabolic disorders, as well as the underlying mechanisms. The effects of modulating interventions, such as prebiotics, probiotics, fecal microbiota transplantation, and other new treatment possibilities on these metabolic disorders have also been reported. A growing body of evidence highlights the role of gut microbiota in the development of dysbiosis, which in turn influences host metabolism and disease phenotypes. Further studies are required to elucidate the precise mechanisms by which gut microbiota-derived mediators induce metabolic disorders and modulating interventions exert their beneficial effects in humans. The gut microbiota represents a novel potential therapeutic target for a range of metabolic disorders. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Alanine rich peptide from Populus trichocarpa inhibit growth of Staphylococcus aureus via targetting its extracellular domain of Sensor Histidine Kinase YycGex protein.

PubMed

Al Akeel, Raid; Mateen, Ayesha; Syed, Rabbani; Alqahtani, Mohammed S; Alqahtani, Ali S

2018-05-22

Due to growing concern towards microbial resistance, ongoing search for developing novel bioactive compounds such as peptides is on rise. The aim of this study was to evaluate antimicrobial effect of Populus trichocarpa extract, chemically identify the active peptide fraction and finds its target in Staphylococcus aureus. In this study the active fraction of P. trichocarpa crude extract was purified and characterized using MS/MS. This peptide PT13 antimicrobial activity was confirmed by in-vitro agar based disk diffusion and in-vivo infection model of G. mellonella. The proteomic expression analysis of S. aureus under influence of PT13 was studied using LTQ-Orbitrap-MS in-solution digestion and identity of target protein was acquired with their quantified expression using label-free approach of Progenesis QI software. Docking study was performed with peptide PT13 and its target YycG protein using CABS-dock. The active fraction PT13 sequence was identified as KVPVAAAAAAAAAVVASSMVVAAAK, with 25 amino acid including 13 alanine having M/Z 2194.2469. PT13 was uniformly inhibited growth S. aureus SA91 and MIC was determined 16 μg/mL for SA91 S. aureus strain. Sensor histidine kinase (YycG) was most significant target found differentially expressed under influence of PT13. G. mellonella larvae were killed rapidly due to S aureus infection, whereas death in protected group was insignificant in compare to control. The docking models showed ten docking models with RMSD value 1.89 for cluster 1 and RMSD value 3.95 for cluster 2 which is predicted to be high quality model. Alanine rich peptide could be useful in constructing as antimicrobial peptide for targeting extracellular Domain of Sensor Histidine Kinase YycG from S. aureus used in the study. Copyright © 2018 Elsevier Ltd. All rights reserved.

New Potent Membrane-Targeting Antibacterial Peptides from Viral Capsid Proteins

PubMed Central

Dias, Susana A.; Freire, João M.; Pérez-Peinado, Clara; Domingues, Marco M.; Gaspar, Diana; Vale, Nuno; Gomes, Paula; Andreu, David; Henriques, Sónia T.; Castanho, Miguel A. R. B.; Veiga, Ana S.

2017-01-01

The increasing prevalence of multidrug-resistant bacteria urges the development of new antibacterial agents. With a broad spectrum activity, antimicrobial peptides have been considered potential antibacterial drug leads. Using bioinformatic tools we have previously shown that viral structural proteins are a rich source for new bioactive peptide sequences, namely antimicrobial and cell-penetrating peptides. Here, we test the efficacy and mechanism of action of the most promising peptides among those previously identified against both Gram-positive and Gram-negative bacteria. Two cell-penetrating peptides, vCPP 0769 and vCPP 2319, have high antibacterial activity against Staphylococcus aureus, MRSA, Escherichia coli, and Pseudomonas aeruginosa, being thus multifunctional. The antibacterial mechanism of action of the two most active viral protein-derived peptides, vAMP 059 and vCPP 2319, was studied in detail. Both peptides act on both Gram-positive S. aureus and Gram-negative P. aeruginosa, with bacterial cell death occurring within minutes. Also, these peptides cause bacterial membrane permeabilization and damage of the bacterial envelope of P. aeruginosa cells. Overall, the results show that structural viral proteins are an abundant source for membrane-active peptides sequences with strong antibacterial properties. PMID:28522994

A novel transferrin receptor-targeted hybrid peptide disintegrates cancer cell membrane to induce rapid killing of cancer cells

PubMed Central

2011-01-01

Background Transferrin receptor (TfR) is a cell membrane-associated glycoprotein involved in the cellular uptake of iron and the regulation of cell growth. Recent studies have shown the elevated expression levels of TfR on cancer cells compared with normal cells. The elevated expression levels of this receptor in malignancies, which is the accessible extracellular protein, can be a fascinating target for the treatment of cancer. We have recently designed novel type of immunotoxin, termed "hybrid peptide", which is chemically synthesized and is composed of target-binding peptide and lytic peptide containing cationic-rich amino acids components that disintegrates the cell membrane for the cancer cell killing. The lytic peptide is newly designed to induce rapid killing of cancer cells due to conformational change. In this study, we designed TfR binding peptide connected with this novel lytic peptide and assessed the cytotoxic activity in vitro and in vivo. Methods In vitro: We assessed the cytotoxicity of TfR-lytic hybrid peptide for 12 cancer and 2 normal cell lines. The specificity for TfR is demonstrated by competitive assay using TfR antibody and siRNA. In addition, we performed analysis of confocal fluorescence microscopy and apoptosis assay by Annexin-V binding, caspase activity, and JC-1 staining to assess the change in mitochondria membrane potential. In vivo: TfR-lytic was administered intravenously in an athymic mice model with MDA-MB-231 cells. After three weeks tumor sections were histologically analyzed. Results The TfR-lytic hybrid peptide showed cytotoxic activity in 12 cancer cell lines, with IC50 values as low as 4.0-9.3 μM. Normal cells were less sensitive to this molecule, with IC50 values > 50 μM. Competition assay using TfR antibody and knockdown of this receptor by siRNA confirmed the specificity of the TfR-lytic hybrid peptide. In addition, it was revealed that this molecule can disintegrate the cell membrane of T47D cancer cells just in 10

Photodissociative Cross-Linking of Non-covalent Peptide-Peptide Ion Complexes in the Gas Phase

NASA Astrophysics Data System (ADS)

Nguyen, Huong T. H.; Andrikopoulos, Prokopis C.; Rulíšek, Lubomír; Shaffer, Christopher J.; Tureček, František

2018-05-01

We report a gas-phase UV photodissociation study investigating non-covalent interactions between neutral hydrophobic pentapeptides and peptide ions incorporating a diazirine-tagged photoleucine residue. Phenylalanine (Phe) and proline (Pro) were chosen as the conformation-affecting residues that were incorporated into a small library of neutral pentapeptides. Gas-phase ion-molecule complexes of these peptides with photo-labeled pentapeptides were subjected to photodissociation. Selective photocleavage of the diazirine ring at 355 nm formed short-lived carbene intermediates that underwent cross-linking by insertion into H-X bonds of the target peptide. The cross-link positions were established from collision-induced dissociation tandem mass spectra (CID-MS3) providing sequence information on the covalent adducts. Effects of the amino acid residue (Pro or Phe) and its position in the target peptide sequence were evaluated. For proline-containing peptides, interactions resulting in covalent cross-links in these complexes became more prominent as proline was moved towards the C-terminus of the target peptide sequence. The photocross-linking yields of phenylalanine-containing peptides depended on the position of both phenylalanine and photoleucine. Density functional theory calculations were used to assign structures of low-energy conformers of the (GLPMG + GLL*LK + H)+ complex. Born-Oppenheimer molecular dynamics trajectory calculations were used to capture the thermal motion in the complexes within 100 ps and determine close contacts between the incipient carbene and the H-X bonds in the target peptide. This provided atomic-level resolution of potential cross-links that aided spectra interpretation and was in agreement with experimental data. [Figure not available: see fulltext.

Capsaicin in Metabolic Syndrome

PubMed Central

Bliss, Edward

2018-01-01

Capsaicin, the major active constituent of chilli, is an agonist on transient receptor potential vanilloid channel 1 (TRPV1). TRPV1 is present on many metabolically active tissues, making it a potentially relevant target for metabolic interventions. Insulin resistance and obesity, being the major components of metabolic syndrome, increase the risk for the development of cardiovascular disease, type 2 diabetes, and non-alcoholic fatty liver disease. In vitro and pre-clinical studies have established the effectiveness of low-dose dietary capsaicin in attenuating metabolic disorders. These responses of capsaicin are mediated through activation of TRPV1, which can then modulate processes such as browning of adipocytes, and activation of metabolic modulators including AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor α (PPARα), uncoupling protein 1 (UCP1), and glucagon-like peptide 1 (GLP-1). Modulation of these pathways by capsaicin can increase fat oxidation, improve insulin sensitivity, decrease body fat, and improve heart and liver function. Identifying suitable ways of administering capsaicin at an effective dose would warrant its clinical use through the activation of TRPV1. This review highlights the mechanistic options to improve metabolic syndrome with capsaicin. PMID:29772784

Capsaicin in Metabolic Syndrome.

PubMed

Panchal, Sunil K; Bliss, Edward; Brown, Lindsay

2018-05-17

Capsaicin, the major active constituent of chilli, is an agonist on transient receptor potential vanilloid channel 1 (TRPV1). TRPV1 is present on many metabolically active tissues, making it a potentially relevant target for metabolic interventions. Insulin resistance and obesity, being the major components of metabolic syndrome, increase the risk for the development of cardiovascular disease, type 2 diabetes, and non-alcoholic fatty liver disease. In vitro and pre-clinical studies have established the effectiveness of low-dose dietary capsaicin in attenuating metabolic disorders. These responses of capsaicin are mediated through activation of TRPV1, which can then modulate processes such as browning of adipocytes, and activation of metabolic modulators including AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor α (PPARα), uncoupling protein 1 (UCP1), and glucagon-like peptide 1 (GLP-1). Modulation of these pathways by capsaicin can increase fat oxidation, improve insulin sensitivity, decrease body fat, and improve heart and liver function. Identifying suitable ways of administering capsaicin at an effective dose would warrant its clinical use through the activation of TRPV1. This review highlights the mechanistic options to improve metabolic syndrome with capsaicin.

RGD peptide-targeted polyethylenimine-entrapped gold nanoparticles for targeted CT imaging of an orthotopic model of human hepatocellular carcinoma

NASA Astrophysics Data System (ADS)

Zhou, Benqing; Wang, Meng; Zhou, Feifan; Song, Jun; Qu, Junle; Chen, Wei R.

2018-02-01

We report the synthesis and characterization of arginine-glycine-aspartic acid (RGD) peptide-targeted polyethylenimine (PEI)-entrapped gold nanoparticles (RGD-Au PENPs) for targeted CT imaging of hepatic carcinomas in situ. In this work, PEI sequentially modified with polyethylene glycol (PEG), and RGD linked-PEG was used as a nanoplatform to prepare AuNPs, followed by complete acetylation of PEI surface amines. We showed that the designed RGD-Au PENPs were colloidally stable and biocompatible in the given concentration range, and could be specifically taken up by αvβ3 integrin-overexpressing liver cancer cells in vitro. Furthermore, in vivo CT imaging results revealed that the particles displayed a great contrast enhancement of hepatic carcinomas region, and could target to hepatic carcinomas region in situ. With the proven biodistribution and histological examinations in vivo, the synthesized RGD-Au PENPs show a great formulation to be used as a contrast agent for targeted CT imaging of different αvβ3 integrin receptoroverexpressing tumors.

Targeted Mass Spectrometric Approach for Biomarker Discovery and Validation with Nonglycosylated Tryptic Peptides from N-linked Glycoproteins in Human Plasma*

PubMed Central

Lee, Ju Yeon; Kim, Jin Young; Park, Gun Wook; Cheon, Mi Hee; Kwon, Kyung-Hoon; Ahn, Yeong Hee; Moon, Myeong Hee; Lee, Hyoung–Joo; Paik, Young Ki; Yoo, Jong Shin

2011-01-01

A simple mass spectrometric approach for the discovery and validation of biomarkers in human plasma was developed by targeting nonglycosylated tryptic peptides adjacent to glycosylation sites in an N-linked glycoprotein, one of the most important biomarkers for early detection, prognoses, and disease therapies. The discovery and validation of novel biomarkers requires complex sample pretreatment steps, such as depletion of highly abundant proteins, enrichment of desired proteins, or the development of new antibodies. The current study exploited the steric hindrance of glycan units in N-linked glycoproteins, which significantly affects the efficiency of proteolytic digestion if an enzymatically active amino acid is adjacent to the N-linked glycosylation site. Proteolytic digestion then results in quantitatively different peptide products in accordance with the degree of glycosylation. The effect of glycan steric hindrance on tryptic digestion was first demonstrated using alpha-1-acid glycoprotein (AGP) as a model compound versus deglycosylated alpha-1-acid glycoprotein. Second, nonglycosylated tryptic peptide biomarkers, which generally show much higher sensitivity in mass spectrometric analyses than their glycosylated counterparts, were quantified in human hepatocellular carcinoma plasma using a label-free method with no need for N-linked glycoprotein enrichment. Finally, the method was validated using a multiple reaction monitoring analysis, demonstrating that the newly discovered nonglycosylated tryptic peptide targets were present at different levels in normal and hepatocellular carcinoma plasmas. The area under the receiver operating characteristic curve generated through analyses of nonglycosylated tryptic peptide from vitronectin precursor protein was 0.978, the highest observed in a group of patients with hepatocellular carcinoma. This work provides a targeted means of discovering and validating nonglycosylated tryptic peptides as biomarkers in human plasma

Sensitivity of tumor cells towards CIGB-300 anticancer peptide relies on its nucleolar localization.

PubMed

Perera, Yasser; Costales, Heydi C; Diaz, Yakelin; Reyes, Osvaldo; Farina, Hernan G; Mendez, Lissandra; Gómez, Roberto E; Acevedo, Boris E; Gomez, Daniel E; Alonso, Daniel F; Perea, Silvio E

2012-04-01

CIGB-300 is a novel anticancer peptide that impairs the casein kinase 2-mediated phosphorylation by direct binding to the conserved phosphoacceptor site on their substrates. Previous findings indicated that CIGB-300 inhibits tumor cell proliferation in vitro and induces tumor growth delay in vivo in cancer animal models. Interestingly, we had previously demonstrated that the putative oncogene B23/nucleophosmin (NPM) is the major intracellular target for CIGB-300 in a sensitive human lung cancer cell line. However, the ability of this peptide to target B23/NPM in cancer cells with differential CIGB-300 response phenotype remained to be determined. Interestingly, in this work, we evidenced that CIGB-300's antiproliferative activity on tumor cells strongly correlates with its nucleolar localization, the main subcellular localization of the previously identified B23/NPM target. Likewise, using CIGB-300 equipotent doses (concentration that inhibits 50% of proliferation), we demonstrated that this peptide interacts and inhibits B23/NPM phosphorylation in different cancer cell lines as evidenced by in vivo pull-down and metabolic labeling experiments. Moreover, such inhibition was followed by a fast apoptosis on CIGB-300-treated cells and also an impairment of cell cycle progression mainly after 5 h of treatment. Altogether, our data not only validates B23/NPM as a main target for CIGB-300 in cancer cells but also provides the first experimental clues to explain their differential antiproliferative response. Importantly, our findings suggest that further improvements to this cell penetrating peptide-based drug should entail its more efficient intracellular delivery at such subcellular localization. Copyright © 2012 European Peptide Society and John Wiley & Sons, Ltd.

Synthesis of linear and cyclic peptide-PEG-lipids for stabilization and targeting of cationic liposome-DNA complexes.

PubMed

Ewert, Kai K; Kotamraju, Venkata Ramana; Majzoub, Ramsey N; Steffes, Victoria M; Wonder, Emily A; Teesalu, Tambet; Ruoslahti, Erkki; Safinya, Cyrus R

2016-03-15

Because nucleic acids (NAs) have immense potential value as therapeutics, the development of safe and effective synthetic NA vectors continues to attract much attention. In vivo applications of NA vectors require stabilized, nanometer-scale particles, but the commonly used approaches of steric stabilization with a polymer coat (e.g., PEGylation; PEG=poly(ethylene glycol)) interfere with attachment to cells, uptake, and endosomal escape. Conjugation of peptides to PEG-lipids can improve cell attachment and uptake for cationic liposome-DNA (CL-DNA) complexes. We present several synthetic approaches to peptide-PEG-lipids and discuss their merits and drawbacks. A lipid-PEG-amine building block served as the common key intermediate in all synthetic routes. Assembling the entire peptide-PEG-lipid by manual solid phase peptide synthesis (employing a lipid-PEG-carboxylic acid) allowed gram-scale synthesis but is mostly applicable to linear peptides connected via their N-terminus. Conjugation via thiol-maleimide or strain-promoted (copper-free) azide-alkyne cycloaddition chemistry is highly amenable to on-demand preparation of peptide-PEG-lipids, and the appropriate PEG-lipid precursors are available in a single chemical step from the lipid-PEG-amine building block. Azide-alkyne cycloaddition is especially suitable for disulfide-bridged peptides such as iRGD (cyclic CRGDKGPDC). Added at 10 mol% of a cationic/neutral lipid mixture, the peptide-PEG-lipids stabilize the size of CL-DNA complexes. They also affect cell attachment and uptake of nanoparticles in a peptide-dependent manner, thereby providing a platform for preparing stabilized, affinity-targeted CL-DNA nanoparticles. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biomedical Applications of Organometal-Peptide Conjugates

NASA Astrophysics Data System (ADS)

Metzler-Nolte, Nils

Peptides are well suited as targeting vectors for the directed delivery of metal-based drugs or probes for biomedical investigations. This chapter describes synthetic strategies for the preparation of conjugates of medically interesting peptides with covalently bound metal complexes. Peptides that were used include neuropeptides (enkephalin, neuropeptide Y, neurotensin), uptake peptides (TAT and poly-Arg), and intracellular localization sequences. To these peptides, a whole variety of transition metal complexes has been attached in recent years by solid-phase peptide synthesis (SPPS) techniques. The metal complex can be attached to the peptide on the resin as part of the SPPS scheme. Alternatively, the metal complex may be attached to the peptide as a postsynthetic modification. Advantages as well as disadvantages for either strategy are discussed. Biomedical applications include radiopharmaceutical applications, anticancer and antibacterial activity, metal-peptide conjugates as targeted CO-releasing molecules, and metal-peptide conjugates in biosensor applications.

The anorexigenic peptide neurotensin relates to insulin sensitivity in obese patients after BPD or RYGB metabolic surgery.

PubMed

von Loeffelholz, Christian; Gissey, Lidia Castagneto; Schumann, Tina; Henke, Christine; Kurzbach, Anica; Struck, Joachim; Bergmann, Andreas; Hanefeld, Markolf; Schatz, Ulrike; Bornstein, Stefan R; Casella, Giovanni; Mingrone, Geltrude; Birkenfeld, Andreas L

2018-05-24

Neurotensin is a peptide with effects on appetite and intestinal lipid absorption. Experimental data suggest a role in glucose homeostasis, while human data is missing. Here, 20 morbidly obese subjects either underwent biliopancreatic diversion with duodenal switch (BPD), or Roux-en-Y gastric bypass (RYGB) in a randomized fashion. Before and 1 year after surgery, anthropometric data, body composition, clinical biochemistry, insulin sensitivity by means of euglycemic hyperinsulinemic clamps (HEC) and fasting plasma proneurotensin 1-117 were analyzed. Plasma proneurotensin increased significantly more 1 year after BDP than RYGB (P = 0.028), while weight loss was comparable. After metabolic surgery, proneurotensin correlated positively with insulin sensitivity (M-value) (r = 0.55, P < 0.001), while an inverse relationship with fasting glucose, HOMA-IR and HbA1c was observed (P < 0.05 for all components). After adjustment for age and gender, proneurotensin and BMI remained independently related with delta of M-value (β = 0.46 and β = 0.51, P < 0.05, resp.). From these data we conclude that proneurotensin positively correlates with insulin sensitivity uniquely after weight loss induced by metabolic surgery in humans. BDP leads to a stronger increase in the anorexigenic peptide compared to RYGB.

Targeting gastrin-releasing peptide as a new approach to treat aggressive refractory neuroblastomas.

PubMed

Paul, Pritha; Gillory, Lauren A; Kang, JungHee; Qiao, Jingbo; Chung, Dai H

2011-03-01

The overall survival for neuroblastoma remains dismal, in part due to the emergence of resistance to chemotherapeutic drugs. We have demonstrated that gastrin-releasing peptide (GRP), a gut peptide secreted by neuroblastoma, acts as an autocrine growth factor. We hypothesized that knockdown of GRP will induce apoptosis in neuroblastoma cells and potentiate the cytotoxic effects of chemotherapeutic agents. The human neuroblastoma cell lines (JF, SK-N-SH) were transfected with small interfering (si) RNA targeted at GRP. Apoptosis was assessed by DNA fragmentation assay. Immunoblotting was used to confirm molecular markers of apoptosis, and flow cytometry was performed to determine cell cycle arrest after GRP knockdown. siGRP resulted in an increase in apoptosis in the absence of chemotherapeutic interventions. A combination of GRP silencing and chemotherapeutic drugs resulted in enhanced apoptosis when compared to either of the treatments alone. GRP silencing led to increased expression of proapoptotic proteins, p53 and p21. Silencing of GRP induces apoptosis in neuroblastoma cells; it acts synergistically with chemotherapeutic effects of etoposide and vincristine. GRP knockdown-mediated apoptosis appears to be associated with upregulation of p53 in neuroblastoma cells. Targeting GRP may be postulated as a potential novel agent for combinational treatment to treat aggressive neuroblastomas. Copyright © 2011 Mosby, Inc. All rights reserved.

Targeting Metabolic Reprogramming by Influenza Infection for Therapeutic Intervention

DOE PAGES

Smallwood, Heather S.; Duan, Susu; Morfouace, Marie; ...

2017-05-23

Influenza is a worldwide health and financial burden posing a significant risk to the immune-compromised, obese, diabetic, elderly, and pediatric populations. We identified increases in glucose metabolism in the lungs of pediatric patients infected with respiratory pathogens. Using quantitative mass spectrometry, we found metabolic changes occurring after influenza infection in primary human respiratory cells and validated infection-associated increases in c-Myc, glycolysis, and glutaminolysis. We confirmed these findings with a metabolic drug screen that identified the PI3K/mTOR inhibitor BEZ235 as a regulator of infectious virus production. BEZ235 treatment ablated the transient induction of c-Myc, restored PI3K/mTOR pathway homeostasis measured by 4E-BP1more » and p85 phosphorylation, and reversed infection-induced changes in metabolism. Importantly, BEZ235 reduced infectious progeny but had no effect on the early stages of viral replication. BEZ235 significantly increased survival in mice, while reducing viral titer. We show metabolic reprogramming of host cells by influenza virus exposes targets for therapeutic intervention.« less

Targeting Metabolic Reprogramming by Influenza Infection for Therapeutic Intervention

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smallwood, Heather S.; Duan, Susu; Morfouace, Marie

Influenza is a worldwide health and financial burden posing a significant risk to the immune-compromised, obese, diabetic, elderly, and pediatric populations. We identified increases in glucose metabolism in the lungs of pediatric patients infected with respiratory pathogens. Using quantitative mass spectrometry, we found metabolic changes occurring after influenza infection in primary human respiratory cells and validated infection-associated increases in c-Myc, glycolysis, and glutaminolysis. We confirmed these findings with a metabolic drug screen that identified the PI3K/mTOR inhibitor BEZ235 as a regulator of infectious virus production. BEZ235 treatment ablated the transient induction of c-Myc, restored PI3K/mTOR pathway homeostasis measured by 4E-BP1more » and p85 phosphorylation, and reversed infection-induced changes in metabolism. Importantly, BEZ235 reduced infectious progeny but had no effect on the early stages of viral replication. BEZ235 significantly increased survival in mice, while reducing viral titer. We show metabolic reprogramming of host cells by influenza virus exposes targets for therapeutic intervention.« less

Molecular targets of antihypertensive peptides: understanding the mechanisms of action based on the pathophysiology of hypertension.

PubMed

Majumder, Kaustav; Wu, Jianping

2014-12-24

There is growing interest in using functional foods or nutraceuticals for the prevention and treatment of hypertension or high blood pressure. Although numerous preventive and therapeutic pharmacological interventions are available on the market, unfortunately, many patients still suffer from poorly controlled hypertension. Furthermore, most pharmacological drugs, such as inhibitors of angiotensin-I converting enzyme (ACE), are often associated with significant adverse effects. Many bioactive food compounds have been characterized over the past decades that may contribute to the management of hypertension; for example, bioactive peptides derived from various food proteins with antihypertensive properties have gained a great deal of attention. Some of these peptides have exhibited potent in vivo antihypertensive activity in both animal models and human clinical trials. This review provides an overview about the complex pathophysiology of hypertension and demonstrates the potential roles of food derived bioactive peptides as viable interventions targeting specific pathways involved in this disease process. This review offers a comprehensive guide for understanding and utilizing the molecular mechanisms of antihypertensive actions of food protein derived peptides.

Molecular Targets of Antihypertensive Peptides: Understanding the Mechanisms of Action Based on the Pathophysiology of Hypertension

PubMed Central

Majumder, Kaustav; Wu, Jianping

2014-01-01

There is growing interest in using functional foods or nutraceuticals for the prevention and treatment of hypertension or high blood pressure. Although numerous preventive and therapeutic pharmacological interventions are available on the market, unfortunately, many patients still suffer from poorly controlled hypertension. Furthermore, most pharmacological drugs, such as inhibitors of angiotensin-I converting enzyme (ACE), are often associated with significant adverse effects. Many bioactive food compounds have been characterized over the past decades that may contribute to the management of hypertension; for example, bioactive peptides derived from various food proteins with antihypertensive properties have gained a great deal of attention. Some of these peptides have exhibited potent in vivo antihypertensive activity in both animal models and human clinical trials. This review provides an overview about the complex pathophysiology of hypertension and demonstrates the potential roles of food derived bioactive peptides as viable interventions targeting specific pathways involved in this disease process. This review offers a comprehensive guide for understanding and utilizing the molecular mechanisms of antihypertensive actions of food protein derived peptides. PMID:25547491

A Promising Therapeutic Target for Metabolic Diseases: Neuropeptide Y Receptors in Humans.

PubMed

Yi, Min; Li, Hekai; Wu, Zhiye; Yan, Jianyun; Liu, Qicai; Ou, Caiwen; Chen, Minsheng

2018-01-01

Human neuropeptide Y (hNPY) is one of the most widely expressed neurotransmitters in the human central and peripheral nervous systems. It consists of 36 highly conserved amino acid residues, and was first isolated from the porcine hypothalamus in 1982. While it is the most recently discovered member of the pancreatic polypeptide family (which includes neuropeptide Y, gut-derived hormone peptide YY, and pancreatic polypeptide), NPY is the most abundant peptide found in the mammalian brain. In order to exert particular functions, NPY needs to bind to the NPY receptor to activate specific signaling pathways. NPY receptors belong to the class A or rhodopsin-like G-protein coupled receptor (GPCR) family and signal via cell-surface receptors. By binding to GPCRs, NPY plays a crucial role in various biological processes, including cortical excitability, stress response, food intake, circadian rhythms, and cardiovascular function. Abnormal regulation of NPY is involved in the development of a wide range of diseases, including obesity, hypertension, atherosclerosis, epilepsy, metabolic disorders, and many cancers. Thus far, five receptors have been cloned from mammals (Y1, Y2, Y4, Y5, and y6), but only four of these (hY1, hY2, hY4, and hY5) are functional in humans. In this review, we summarize the structural characteristics of human NPY receptors and their role in metabolic diseases. © 2018 The Author(s). Published by S. Karger AG, Basel.

Assessment of meat authenticity using bioinformatics, targeted peptide biomarkers and high-resolution mass spectrometry.

PubMed

Ruiz Orduna, Alberto; Husby, Erik; Yang, Charles T; Ghosh, Dipankar; Beaudry, Francis

2015-01-01

In recent years a significant increase of food fraud has been observed, ranging from false label claims to the use of additives and fillers to increase profitability. Recently in 2013 horse and pig DNAs were detected in beef products sold from several retailers. Mass spectrometry (MS) has become the workhorse in protein research, and the detection of marker proteins could serve for both animal species and tissue authentication. Meat species authenticity is performed in this paper using a well-defined proteogenomic annotation, carefully chosen surrogate tryptic peptides and analysis using a hybrid quadrupole-Orbitrap MS. Selected mammalian meat samples were homogenised and proteins were extracted and digested with trypsin. The samples were analysed using a high-resolution MS. Chromatography was achieved using a 30-min linear gradient along with a BioBasic C8 100 × 1 mm column at a flow rate of 75 µl min(-1). The MS was operated in full-scan high resolution and accurate mass. MS/MS spectra were collected for selected proteotypic peptides. Muscular proteins were methodically analysed in silico in order to generate tryptic peptide mass lists and theoretical MS/MS spectra. Following a comprehensive bottom-up proteomic analysis, we detected and identified a proteotypic myoglobin tryptic peptide (120-134) for each species with observed m/z below 1.3 ppm compared with theoretical values. Moreover, proteotypic peptides from myosin-1, myosin-2 and β-haemoglobin were also identified. This targeted method allowed comprehensive meat speciation down to 1% (w/w) of undesired product.

Renal targeted delivery of triptolide by conjugation to the fragment peptide of human serum albumin.

PubMed

Yuan, Zhi-xiang; Wu, Xiao-juan; Mo, Jingxin; Wang, Yan-li; Xu, Chao-qun; Lim, Lee Yong

2015-08-01

We have previously demonstrated that peptide fragments (PFs) of the human serum albumin could be developed as potential renal targeting carriers, in particular, the peptide fragment, PF-A299-585 (A299-585 representing the amino acid sequence of the human serum albumin). In this paper, we conjugated triptolide (TP), the anti-inflammatory Chinese traditional medicine, to PF-A299-585 via a succinic acid spacer to give TPS-PF-A299-585 (TP loading 2.2% w/w). Compared with the free TP, TPS-PF-A299-585 exhibited comparable anti-inflammatory activity in the lipopolysaccharide stimulated MDCK cells, but was significantly less cytotoxic than the free drug. Accumulation of TPS-PF-A299-585 in the MDCK cells in vitro and in rodent kidneys in vivo was demonstrated using FITC-labeled TPS-PF-A299-585. Renal targeting was confirmed in vivo in a membranous nephropathic (MN) rodent model, where optical imaging and analyses of biochemical markers were combined to show that TPS-PF-A299-585 was capable of alleviating the characteristic symptoms of MN. The collective data affirm PF-A299-585 to be a useful carrier for targeting TP to the kidney. Copyright © 2015 Elsevier B.V. All rights reserved.

Therapeutic peptides for cancer therapy. Part II - cell cycle inhibitory peptides and apoptosis-inducing peptides.

PubMed

Raucher, Drazen; Moktan, Shama; Massodi, Iqbal; Bidwell, Gene L

2009-10-01

Therapeutic peptides have great potential as anticancer agents owing to their ease of rational design and target specificity. However, their utility in vivo is limited by low stability and poor tumor penetration. The authors review the development of peptide inhibitors with potential for cancer therapy. Peptides that arrest the cell cycle by mimicking CDK inhibitors or induce apoptosis directly are discussed. The authors searched Medline for articles concerning the development of therapeutic peptides and their delivery. Inhibition of cancer cell proliferation directly using peptides that arrest the cell cycle or induce apoptosis is a promising strategy. Peptides can be designed that interact very specifically with cyclins and/or cyclin-dependent kinases and with members of apoptotic cascades. Use of these peptides is not limited by their design, as a rational approach to peptide design is much less challenging than the design of small molecule inhibitors of specific protein-protein interactions. However, the limitations of peptide therapy lie in the poor pharmacokinetic properties of these large, often charged molecules. Therefore, overcoming the drug delivery hurdles could open the door for effective peptide therapy, thus making an entirely new class of molecules useful as anticancer drugs.

Self-Assembled Peptide-Lanthanide Nanoclusters for Safe Tumor Therapy: Overcoming and Utilizing Biological Barriers to Peptide Drug Delivery.

PubMed

Yan, Jin; He, Wangxiao; Yan, Siqi; Niu, Fan; Liu, Tianya; Ma, Bohan; Shao, Yongping; Yan, Yuwei; Yang, Guang; Lu, Wuyuan; Du, Yaping; Lei, Bo; Ma, Peter X

2018-02-27

Developing a sophisticated nanomedicine platform to deliver therapeutics effectively and safely into tumor/cancer cells remains challenging in the field of nanomedicine. In particular, reliable peptide drug delivery systems capable of overcoming biological barriers are still lacking. Here, we developed a simple, rapid, and robust strategy to manufacture nanoclusters of ∼90 nm in diameter that are self-assembled from lanthanide-doped nanoparticles (5 nm), two anticancer peptides with different targets (BIM and PMI), and one cyclic peptide iNGR targeted to cancer cells. The peptide-lanthanide nanoclusters (LDC-PMI-BIM-iNGR) enhanced the resistance of peptide drugs to proteolysis, disassembled in response to reductive conditions that are present in the tumor microenvironment and inhibited cancer cell growth in vitro and in vivo. Notably, LDC-PMI-BIM-iNGR exhibited extremely low systemic toxicity and side effects in vivo. Thus, the peptide-lanthanide nanocluster may serve as an ideal multifunctional platform for safe, targeted, and efficient peptide drug delivery in cancer therapy.

Fusogenic-Oligoarginine Peptide-Mediated Delivery of siRNAs Targeting the CIP2A Oncogene into Oral Cancer Cells

PubMed Central

Cantini, Liliana; Attaway, Christopher C.; Butler, Betsy; Andino, Lourdes M.; Sokolosky, Melissa L.; Jakymiw, Andrew

2013-01-01

Despite a better understanding of the pathogenesis of oral cancer, its treatment outcome remains poor. Thus, there is a need for new therapeutic strategies to improve the prognosis of this disease. RNA interference (RNAi) appears to be a promising therapeutic tool for the treatment of many diseases, including oral cancer. However, an obstacle for RNAi-mediated therapies has been delivery, in particular, the retention of small interfering RNAs (siRNAs) in endosomes and their subsequent degradation in lysosomes, resulting in inefficient gene silencing. Thus, the current study examined the feasibility of designing and utilizing a peptide, termed 599, consisting of a synthetic influenza virus-derived endosome-disruptive fusogenic peptide sequence and a stretch of cationic cell-penetrating nona(D-arginine) residues, to deliver siRNAs into oral cancer cells and induce silencing of the therapeutic target, CIP2A, an oncoprotein overexpressed in various human malignancies including oral cancer. Increasing the 599 peptide-to-siRNA molar ratio demonstrated a higher binding capacity for siRNA molecules and enhanced siRNA delivery into the cytoplasm of oral cancer cells. In fact, quantitative measurements of siRNA delivery into cells demonstrated that a 50∶1 peptide-to-siRNA molar ratio could deliver 18-fold higher amounts of siRNAs compared to cells treated with siRNA alone with no significant long-term cytotoxic effects. Most importantly, the 599 peptide-mediated siRNA delivery promoted significant CIP2A mRNA and protein silencing which resulted in decreased oral cancer cell invasiveness and anchorage-independent growth. Together, these data demonstrate that a chimeric peptide consisting of a fusogenic sequence, in combination with cell-penetrating residues, can be used to effectively deliver siRNAs into oral cancer cells and induce the silencing of its target gene, potentially offering a new therapeutic strategy in combating oral cancer. PMID:24019920

Distinct Pseudomonas type-III effectors use a cleavable transit peptide to target chloroplasts.

PubMed

Li, Guangyong; Froehlich, John E; Elowsky, Christian; Msanne, Joseph; Ostosh, Andrew C; Zhang, Chi; Awada, Tala; Alfano, James R

2014-01-01

The pathogen Pseudomonas syringae requires a type-III protein secretion system and the effector proteins it injects into plant cells for pathogenesis. The primary role for P. syringae type-III effectors is the suppression of plant immunity. The P. syringae pv. tomato DC3000 HopK1 type-III effector was known to suppress the hypersensitive response (HR), a programmed cell death response associated with effector-triggered immunity. Here we show that DC3000 hopK1 mutants are reduced in their ability to grow in Arabidopsis, and produce reduced disease symptoms. Arabidopsis transgenically expressing HopK1 are reduced in PAMP-triggered immune responses compared with wild-type plants. An N-terminal region of HopK1 shares similarity with the corresponding region in the well-studied type-III effector AvrRps4; however, their C-terminal regions are dissimilar, indicating that they have different effector activities. HopK1 is processed in planta at the same processing site found in AvrRps4. The processed forms of HopK1 and AvrRps4 are chloroplast localized, indicating that the shared N-terminal regions of these type-III effectors represent a chloroplast transit peptide. The HopK1 contribution to virulence and the ability of HopK1 and AvrRps4 to suppress immunity required their respective transit peptides, but the AvrRps4-induced HR did not. Our results suggest that a primary virulence target of these type-III effectors resides in chloroplasts, and that the recognition of AvrRps4 by the plant immune system occurs elsewhere. Moreover, our results reveal that distinct type-III effectors use a cleavable transit peptide to localize to chloroplasts, and that targets within this organelle are important for immunity. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

Comparative assessment of a 99mTc labeled H1299.2-HYNIC peptide bearing two different co-ligands for tumor-targeted imaging.

PubMed

Torabizadeh, Seyedeh Atekeh; Abedi, Seyed Mohammad; Noaparast, Zohreh; Hosseinimehr, Seyed Jalal

2017-05-01

Peptides are a class of targeting agents that bind to cancer-specific cell surfaces. Since they specifically target cancer cells, they could be used as molecular imaging tools. In this study, the 15-mer peptide Ac-H1299.2 (YAAWPASGAWTGTAP) was conjugated with HYNIC via lysine amino acid on C-terminus and labeled with 99m Tc using tricine and EDDA/tricine as the co-ligands. These radiotracers were evaluated for potential utilization in diagnostic imaging of ovarian cancer cells (SKOV-3). The cell-specificity of these radiolabeled peptides was determined based on their binding on an ovarian cancer cell line (SKOV-3), and displaying a low affinity for lung adenocarcinoma cell line (A549) and breast cancer cell line (MCF7). Biodistribution studies were conducted in normal mice as well as in nude mice bearing SKOV-3 ovarian cancer xenografts. HYNIC-peptide was labeled with 99m Tc with more than 99% efficiency and showed high stability in buffer and serum. We observed nanomolar binding affinities for both radiolabeled peptides. The tumor uptakes were 3.27%±0.46% and 1.55%±0.20% for tricine and 2.34±1.1% and 1.09%±0.18% for EDDA/tricine at 1 and 4h after injection, respectively. A higher tumor to background ratio and lower radioactivity in the blood were observed for EDDA/tricine co-ligands, leading to clear tumor visualization in imaging with injection of this peptide. This new 99m Tc-labeled peptide selectively targeted ovarian cancer and introduction of a (EDDA/tricine) as a co-ligand improved the pharmacokinetics of 99m Tc-labeled H1299.2 for tumor imaging in animals. Copyright © 2017 Elsevier Ltd. All rights reserved.

Targeted High Performance Liquid Chromatography Tandem Mass Spectrometry-based Metabolomics differentiates metabolic syndrome from obesity.

PubMed

Zhong, Fanyi; Xu, Mengyang; Bruno, Richard S; Ballard, Kevin D; Zhu, Jiangjiang

2017-04-01

Both obesity and the metabolic syndrome are risk factors for type 2 diabetes and cardiovascular disease. Identification of novel biomarkers are needed to distinguish metabolic syndrome from equally obese individuals in order to direct them to early interventions that reduce their risk of developing further health problems. We utilized mass spectrometry-based targeted metabolic profiling of 221 metabolites to evaluate the associations between metabolite profiles and established metabolic syndrome criteria (i.e. elevated waist circumference, hypertension, elevated fasting glucose, elevated triglycerides, and low high-density lipoprotein cholesterol) in plasma samples from obese men ( n = 29; BMI = 35.5 ± 5.2 kg/m 2 ) and women ( n = 40; 34.9 ± 6.7 kg/m 2 ), of which 26 met the criteria for metabolic syndrome (17 men and 9 women). Compared to obese individuals without metabolic syndrome, univariate statistical analysis and partial least squares discriminant analysis showed that a specific group of metabolites from multiple metabolic pathways (i.e. purine metabolism, valine, leucine and isoleucine degradation, and tryptophan metabolism) were associated with the presence of metabolic syndrome. Receiver operating characteristic curves generated based on the PLS-DA models showed excellent areas under the curve (0.85 and 0.96, for metabolites only model and enhanced metabolites model, respectively), high specificities (0.86 and 0.93), and good sensitivities (0.71 and 0.91). Moreover, principal component analysis revealed that metabolic profiles can be used to further differentiate metabolic syndrome with 3 versus 4-5 metabolic syndrome criteria. Collectively, these findings support targeted metabolomics approaches to distinguish metabolic syndrome from obesity alone, and to stratify metabolic syndrome status based on the number of criteria met. Impact statement We utilized mass spectrometry-based targeted metabolic profiling of 221 metabolites to

Targeting of calcitonin gene-related peptide action as a new strategy for migraine treatment.

PubMed

Kuzawińska, Olga; Lis, Krzysztof; Cessak, Grzegorz; Mirowska-Guzel, Dagmara; Bałkowiec-Iskra, Ewa

Migraine is a chronic, recurrent disorder, characterized by attacks of severe pain, affecting around 1% of adult population. Many studies suggest, that trigeminovascular system plays a key role in pathogenesis of migraine and other primary headaches. Calcitonin gene-related peptide (CGRP) is an endogenous substance, which is regarded a key mediator released from trigeminovascular system after stimulation of sensory nerve endings, responsible for dilatation of peripheral vessels and sensory transmission. CGRP is and extensively studied peptide as one of the most promising targets in migraine drug research. In the article we focus on the role of CGRP in the pathophysiology of migraine and present current data on CGRP antagonists and CGRP monoclonal antibodies. Copyright © 2016 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Multicomponent DNA carrier with a vesicular stomatitis virus G-peptide greatly enhances liver-targeted gene expression in mice.

PubMed

Schuster, M J; Wu, G Y; Walton, C M; Wu, C H

1999-01-01

Genes can be targeted to hepatocytes in vitro and in vivo by the use of asialoorosomucoid-polylysine conjugates. After systemic application, this nonviral vector is recognized by highly selective asialoglycoprotein (AsGP) receptors on the sinusoidal liver cell membrane and is taken up via receptor-mediated endocytosis. As most of the DNA is rapidly transferred to lysosomes where it is degraded, transfection efficiency is low and gene expression transient. To address this problem, we incorporated a pH-dependent synthetic hemolytic peptide derived of the G-protein of Vesicular Stomatitis Virus (VSV) into the gene transfer system, to increase endosomal escape of internalized DNA. The multicomponent carrier binds DNA in a nondamaging way, is still recognized by the AsGP receptor, and is targeted to the liver in vivo. Injection of DNA complexes containing a luciferase marker gene resulted in luciferase expression of 29 000 pg/g liver which corresponded to an increase of a factor of 10(3) overexpression after injection of DNA complexes without endosomolytic peptide. Furthermore, the amount of intact transgene within isolated liver cell nuclei was increased by a factor of 10(1)-10(2) by the use of the multicomponent carriers. These results demonstrate that incorporation of a hemolytic peptide into a nonviral vector can greatly increase gene expression while retaining cell type targetability in vivo.

An in vitro and in vivo study of peptide-functionalized nanoparticles for brain targeting: The importance of selective blood-brain barrier uptake.

PubMed

Bode, Gerard H; Coué, Gregory; Freese, Christian; Pickl, Karin E; Sanchez-Purrà, Maria; Albaiges, Berta; Borrós, Salvador; van Winden, Ewoud C; Tziveleka, Leto-Aikaterini; Sideratou, Zili; Engbersen, Johan F J; Singh, Smriti; Albrecht, Krystyna; Groll, Jürgen; Möller, Martin; Pötgens, Andy J G; Schmitz, Christoph; Fröhlich, Eleonore; Grandfils, Christian; Sinner, Frank M; Kirkpatrick, C James; Steinbusch, Harry W M; Frank, Hans-Georg; Unger, Ronald E; Martinez-Martinez, Pilar

2017-04-01

Targeted delivery of drugs across endothelial barriers remains a formidable challenge, especially in the case of the brain, where the blood-brain barrier severely limits entry of drugs into the central nervous system. Nanoparticle-mediated transport of peptide/protein-based drugs across endothelial barriers shows great potential as a therapeutic strategy in a wide variety of diseases. Functionalizing nanoparticles with peptides allows for more efficient targeting to specific organs. We have evaluated the hemocompatibilty, cytotoxicity, endothelial uptake, efficacy of delivery and safety of liposome, hyperbranched polyester, poly(glycidol) and acrylamide-based nanoparticles functionalized with peptides targeting brain endothelial receptors, in vitro and in vivo. We used an ELISA-based method for the detection of nanoparticles in biological fluids, investigating the blood clearance rate and in vivo biodistribution of labeled nanoparticles in the brain after intravenous injection in Wistar rats. Herein, we provide a detailed report of in vitro and in vivo observations. Copyright © 2016 Elsevier Inc. All rights reserved.

Peptide- and Amine-Modified Glucan Particles for the Delivery of Therapeutic siRNA

PubMed Central

Aouadi, Myriam; Vangala, Pranitha; Tencerova, Michaela; Amano, Shinya U.; Nicoloro, Sarah M.; Yawe, Joseph C.; Czech, Michael P.

2016-01-01

Translation of siRNA technology into the clinic is limited by the need for improved delivery systems that target specific cell types. Macrophages are particularly attractive targets for RNAi therapy because they promote pathogenic inflammatory responses in a number of important human diseases. We previously demonstrated that a multi-component formulation of β-1,3-D-glucan-encapsulated siRNA particles (GeRPs) can specifically and potently silence genes in mouse macrophages. A major advance would be to simplify the GeRP system by reducing the number of delivery components, thus enabling more facile manufacturing and future commercialization. Here we report the synthesis and evaluation of a simplified glucan-based particle (GP) capable of delivering siRNA in vivo to selectively silence macrophage genes. Covalent attachment of small-molecule amines and short peptides containing weak bases to GPs facilitated electrostatic interaction of the particles with siRNA and aided in the endosomal release of siRNA by the proton-sponge effect. Modified GPs were non-toxic and were efficiently internalized by macrophages in vitro. When injected intraperitoneally (i.p.), several of the new peptide-modified GPs were found to efficiently deliver siRNA to peritoneal macrophages in lean, healthy mice. In an animal model of obesity-induced inflammation, i.p. administration of one of the peptide-modified GPs (GP-EP14) bound to siRNA selectively reduced the expression of target inflammatory cytokines in the visceral adipose tissue macrophages. Decreasing adipose tissue inflammation resulted in an improvement of glucose metabolism in these metabolically challenged animals. Thus, modified GPs represent a promising new simplified system for the efficient delivery of therapeutic siRNAs specifically to phagocytic cells in vivo for modulation of inflammation responses. PMID:26815386

Toward a new and noninvasive diagnostic method of papillary thyroid cancer by using peptide vectorized contrast agents targeted to galectin-1.

PubMed

Fanfone, Deborah; Despretz, Nadège; Stanicki, Dimitri; Rubio-Magnieto, Jenifer; Fossépré, Mathieu; Surin, Mathieu; Rorive, Sandrine; Salmon, Isabelle; Vander Elst, Luce; Laurent, Sophie; Muller, Robert N; Saussez, Sven; Burtea, Carmen

2017-10-06

The incidence of papillary thyroid cancer has increased these last decades due to a better detection. High prevalence of nodules combined with the low incidence of thyroid cancers constitutes an important diagnostic challenge. We propose to develop an alternative diagnostic method to reduce the number of useless and painful thyroidectomies using a vectorized contrast agent for magnetic resonance imaging. Galectin-1 (gal-1), a protein overexpressed in well-differentiated thyroid cancer, has been targeted with a randomized linear 12-mer peptide library using the phage display technique. Selected peptides have been conjugated to ultrasmall superparamagnetic particles of iron oxide (USPIO). Peptides and their corresponding contrast agents have been tested in vitro for their specific binding and toxicity. Two peptides (P1 and P7) were selected according to their affinity toward gal-1. Their binding has been revealed by immunohistochemistry on human thyroid cancer biopsies, and they were co-localized with gal-1 by immunofluorescence on TPC-1 cell line. Both peptides induce a decrease in TPC-1 cells' adhesion to gal-1 immobilized on culture plates. After coupling to USPIO, the peptides preserved their affinity toward gal-1. Their specific binding has been corroborated by co-localization with gal-1 expressed by TPC-1 cells and by their ability to compete with anti-gal-1 antibody. The peptides and their USPIO derivatives produce no toxicity in HepaRG cells as determined by MTT assay. The vectorized contrast agents are potential imaging probes for thyroid cancer diagnosis. Moreover, the two gal-1-targeted peptides prevent cancer cell adhesion by interacting with the carbohydrate-recognition domain of gal-1.

Tricine co-ligand improved the efficacy of 99mTc-HYNIC-(Ser)3-J18 peptide for targeting and imaging of non-small-cell lung cancer.

PubMed

Shaghaghi, Zahra; Abedi, Seyed Mohammad; Hosseinimehr, Seyed Jalal

2018-05-15

The early diagnosis of non-small cell lung cancer (NSCLC) is important for increasing survival rate and improving quality life of patients. The aim of this study was to investigate 99m  Tc-(tricine)-HYNIC-(Ser) 3 -J18 for targeting and imaging of NSCLC in A-549 xenografted nude mice. The (Ser) 3 -J18 peptide was conjugated with HYNIC and labeled with 99m  Tc using tricine as a co-ligand. The radiolabeled peptide was evaluated for its radiochemical purity, stability, receptor binding and internalization in vitro. The future experiments were performed for tumor targeting and imaging in A-549 tumor-bearing mice. 99m  Tc-(tricine)-HYNIC-(Ser) 3 -J18 was obtained at high labeling efficiency at room temperature and favorable stability in saline and human plasma. At the cellular level, the radiolabeled peptide specifically bond to A-549 cells with a K D 4.1 ± 1.3 nM. Biodistribution study revealed tumor to blood and tumor to muscle ratios were about 3.12 and 5.63 respectively after 2 h injection of radiolabeled peptide. These ratios were significantly decreased by co-injection of excess non-labeled peptide in mice. This radiolabeled peptide selectively targeted to NSCLC tumor and exhibited a high target uptake combined with acceptable low background activity for tumor imaging in mice. The results of this study and its comparison with another study showed that 99m  Tc-(tricine)-HYNIC-(Ser) 3 -J18 is better than previously reported radiolabeled peptide as 99m  Tc-(EDDA/tricine)-HYNIC-(Ser) 3 -J18 for NSCLC targeting and imaging. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Mitochondrial peptides modulate mitochondrial function during cellular senescence.

PubMed

Kim, Su-Jeong; Mehta, Hemal H; Wan, Junxiang; Kuehnemann, Chisaka; Chen, Jingcheng; Hu, Ji-Fan; Hoffman, Andrew R; Cohen, Pinchas

2018-06-10

Cellular senescence is a complex cell fate response that is thought to underlie several age-related pathologies. Despite a loss of proliferative potential, senescent cells are metabolically active and produce energy-consuming effectors, including senescence-associated secretory phenotypes (SASPs). Mitochondria play crucial roles in energy production and cellular signaling, but the key features of mitochondrial physiology and particularly of mitochondria-derived peptides (MDPs), remain underexplored in senescence responses. Here, we used primary human fibroblasts made senescent by replicative exhaustion, doxorubicin or hydrogen peroxide treatment, and examined the number of mitochondria and the levels of mitochondrial respiration, mitochondrial DNA methylation and the mitochondria-encoded peptides humanin, MOTS-c, SHLP2 and SHLP6. Senescent cells showed increased numbers of mitochondria and higher levels of mitochondrial respiration, variable changes in mitochondrial DNA methylation, and elevated levels of humanin and MOTS-c. Humanin and MOTS-c administration modestly increased mitochondrial respiration and selected components of the SASP in doxorubicin-induced senescent cells partially via JAK pathway. Targeting metabolism in senescence cells is an important strategy to reduce SASP production for eliminating the deleterious effects of senescence. These results provide insight into the role of MDPs in mitochondrial energetics and the production of SASP components by senescent cells.

Systemic combinatorial peptide selection yields a non-canonical iron-mimicry mechanism for targeting tumors in a mouse model of human glioblastoma

PubMed Central

Staquicini, Fernanda I.; Ozawa, Michael G.; Moya, Catherine A.; Driessen, Wouter H.P.; Barbu, E. Magda; Nishimori, Hiroyuki; Soghomonyan, Suren; Flores, Leo G.; Liang, Xiaowen; Paolillo, Vincenzo; Alauddin, Mian M.; Basilion, James P.; Furnari, Frank B.; Bogler, Oliver; Lang, Frederick F.; Aldape, Kenneth D.; Fuller, Gregory N.; Höök, Magnus; Gelovani, Juri G.; Sidman, Richard L.; Cavenee, Webster K.; Pasqualini, Renata; Arap, Wadih

2010-01-01

The management of CNS tumors is limited by the blood-brain barrier (BBB), a vascular interface that restricts the passage of most molecules from the blood into the brain. Here we show that phage particles targeted with certain ligand motifs selected in vivo from a combinatorial peptide library can cross the BBB under normal and pathological conditions. Specifically, we demonstrated that phage clones displaying an iron-mimic peptide were able to target a protein complex of transferrin and transferrin receptor (TfR) through a non-canonical allosteric binding mechanism and that this functional protein complex mediated transport of the corresponding viral particles into the normal mouse brain. We also showed that, in an orthotopic mouse model of human glioblastoma, a combination of TfR overexpression plus extended vascular permeability and ligand retention resulted in remarkable brain tumor targeting of chimeric adeno-associated virus/phage particles displaying the iron-mimic peptide and carrying a gene of interest. As a proof of concept, we delivered the HSV thymidine kinase gene for molecular-genetic imaging and targeted therapy of intracranial xenografted tumors. Finally, we established that these experimental findings might be clinically relevant by determining through human tissue microarrays that many primary astrocytic tumors strongly express TfR. Together, our combinatorial selection system and results may provide a translational avenue for the targeted detection and treatment of brain tumors. PMID:21183793

Poly aspartic acid peptide-linked PLGA based nanoscale particles: potential for bone-targeting drug delivery applications.

PubMed

Jiang, Tao; Yu, Xiaohua; Carbone, Erica J; Nelson, Clarke; Kan, Ho Man; Lo, Kevin W-H

2014-11-20

Delivering drugs specifically to bone tissue is very challenging due to the architecture and structure of bone tissue. Poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles (NPs) hold great promise for the delivery of therapeutics to bone tissue. The goal of the present research was to formulate a PLGA-based NP drug delivery system for bone tissue exclusively. Since poly-aspartic acids (poly-Asp) peptide sequence has been shown to bind to hydroxyapatite (HA), and has been suggested as a molecular tool for bone-targeting applications, we fabricated PLGA-based NPs linked with poly-Asp peptide sequence. Nanoparticles made of methoxy - poly(ethylene glycol) (PEG)-PLGA and maleimide-PEG-PLGA were prepared using a water-in-oil-in-water double emulsion and solvent evaporation method. Fluorescein isothiocyanate (FITC)-tagged poly-Asp peptide was conjugated to the surface of the nanoparticles via the alkylation reaction between the sulfhydryl groups at the N-terminal of the peptide and the CC double bond of maleimide at one end of the polymer chain to form thioether bonds. The conjugation of FITC-tagged poly-Asp peptide to PLGA NPs was confirmed by NMR analysis and fluorescent microscopy. The developed nanoparticle system is highly aqueous dispersible with an average particle size of ∼80 nm. In vitro binding analyses demonstrated that FITC-poly-Asp NPs were able to bind to HA gel as well as to mineralized matrices produced by human mesenchymal stem cells and mouse bone marrow stromal cells. Using a confocal microscopy technique, an ex vivo binding study of mouse major organ ground sections revealed that the FITC-poly-Asp NPs were able to bind specifically to the bone tissue. In addition, proliferation studies indicated that our FITC-poly-Asp NPs did not induce cytotoxicity to human osteoblast-like MG63 cell lines. Altogether, these promising results indicated that this nanoscale targeting system was able to bind to bone tissue specifically and might have a great

Myristic Acid-Modified DA7R Peptide for Whole-Process Glioma-Targeted Drug Delivery.

PubMed

Ying, Man; Wang, Songli; Zhang, Mingfei; Wang, Ruifeng; Zhu, Hangchang; Ruan, Huitong; Ran, Danni; Chai, Zhilan; Wang, Xiaoyi; Lu, Weiyue

2018-06-13

The clinical treatment of aggressive glioma has been a great challenge, mainly because of the complexity of the glioma microenvironment and the existence of the blood-brain tumor barrier (BBTB)/blood-brain barrier (BBB), which severely hampers the effective accumulation of most therapeutic agents in the glioma region. Additionally, vasculogenic mimicry (VM), angiogenesis, and glioma stem cells (GSC) in malignant glioma also lead to the failure of clinical therapy. To address the aforementioned issues, a whole-process glioma-targeted drug delivery strategy was proposed. The D A7R peptide has effective BBTB-penetrating and notable glioma-, angiogenesis-, and VM-targeting abilities. Herein, we designed a myristic acid modified D A7R ligand (MC- D A7R), which combines tumor-homing D A7R with BBB-penetrable MC. MC- D A7R was then immobilized to PEGylated liposomes (MC- D A7R-LS) to form a whole-process glioma-targeting system. MC- D A7R-LS exhibited exceptional internalization in glioma, tumor neovascular, and brain capillary endothelial cells. Enhanced BBTB- and BBB-traversing efficiencies were also observed on MC- D A7R-LS. Ex vivo imaging on brain tumors also demonstrated the feasibility of MC- D A7R-LS in intracranial glioma-homing, whereas the immunofluorescence studies demonstrated its GSC and angiogenesis homing. Furthermore, doxorubicin-loaded MC- D A7R-LS accomplished a remarkable therapeutic outcome, as a result of a synergistic improvement on the glioma microenvironment. Our study highlights the potential of the MC-modified D A7R peptide as a great candidate for the whole-process glioma-targeted drug delivery.

Rational Design of Cancer-Targeted Benzoselenadiazole by RGD Peptide Functionalization for Cancer Theranostics.

PubMed

Yang, Liye; Li, Wenying; Huang, Yanyu; Zhou, Yangliang; Chen, Tianfeng

2015-09-01

A cancer-targeted conjugate of the selenadiazole derivative BSeC (benzo[1,2,5] selenadiazole-5-carboxylic acid) with RGD peptide as targeting molecule and PEI (polyethylenimine) as a linker is rationally designed and synthesized in the present study. The results show that RGD-PEI-BSeC forms nanoparticles in aqueous solution with a core-shell nanostructure and high stability under physiological conditions. This rational design effectively enhances the selective cellular uptake and cellular retention of BSeC in human glioma cells, and increases its selectivity between cancer and normal cells. The nanoparticles enter the cells through receptor-mediated endocytosis via clathrin-mediated and nystatin-dependent lipid raft-mediated pathways. Internalized nanoparticles trigger glioma cell apoptosis by activation of ROS-mediated p53 phosphorylation. Therefore, this study provides a strategy for the rational design of selenium-containing cancer-targeted theranostics. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Glucagon-like peptide-1 receptor agonists favorably address all components of metabolic syndrome.

PubMed

Chatterjee, Sanjay; Ghosal, Samit; Chatterjee, Saurav

2016-10-15

Cardiovascular death is the leading cause of mortality for patients with type 2 diabetes mellitus. The etiology of cardiovascular disease in diabetes may be divided into hyperglycemia per se and factors operating through components of metabolic syndrome (MetS). Hyperglycemia causes direct injury to vascular endothelium and possibly on cardiac myocytes. MetS is a cluster of risk factors like obesity, hyperglycemia, hypertension and dyslipidemia. The incidence of this syndrome is rising globally. Glucagon-like peptide-1 receptor agonists (GLP-1RA) are a group of drugs, which address all components of this syndrome favorably. Experimental evidence suggests that they have favorable actions on myocardium as well. Several compounds belonging to GLP-1RA class are in market now and a large number awaiting their entry. Although, originally this class of drugs emerged as a treatment for type 2 diabetes mellitus, more recent data generated revealed beneficial effects on multiple metabolic parameters. We have studied literature published between 2000 and 2016 to look into effects of GLP-1RA on components of MetS. Results from recently concluded clinical trials suggest that some of the molecules in this class may have favorable effects on cardiovascular outcome.

Discovery of a polystyrene binding peptide isolated from phage display library and its application in peptide immobilization.

PubMed

Qiang, Xu; Sun, Keyong; Xing, Lijun; Xu, Yifeng; Wang, Hong; Zhou, Zhengpin; Zhang, Juan; Zhang, Fang; Caliskan, Bilgen; Wang, Min; Qiu, Zheng

2017-06-01

Phage peptide display is a powerful technique for discovery of various target-specific ligands. However, target-unrelated peptides can often be obtained and cause ambiguous results. Peptide PB-TUP has been isolated repeatedly in our laboratory on different targets and we conducted a research on PB-TUP phage to investigate their binding properties and rate of propagation. ELISA and phage recovery assay demonstrated that PB-TUP phage had a significant superior affinity to polystyrene solid surface compared with control phage clones. In this study, some incidental bindings are excluded like blocking agents and non-specific binding of secondary antibodies. Propagation rate assays of the selected phage clones showed that the growth rate of PB-TUP phage was not superior to the control phages. Furthermore, the binding of PB-TUB to polystyrene was concentration dependent and varied with solution pH. Molecular modeling revealed that stable structures of α-helix and β-turn may contribute to the binding of PB-TUP to polystyrene plate. The PB-TUP sequence was fused to the N-terminus of peptide P2 and the fusion peptide significantly increased the binding affinity to polystyrene. The fusion peptide also enhanced the cell adhesion ability of peptide P2 with human umbilical vein endothelial cell (HUVEC). The addition of the polystyrene binding peptide provided a convenient method for peptide immobilization.

Staphylococcus aureus methicillin resistance detected by HPLC-MS/MS targeted metabolic profiling.

PubMed

Schelli, Katie; Rutowski, Joshua; Roubidoux, Julia; Zhu, Jiangjiang

2017-03-15

Recently, novel bioanalytical methods, such as NMR and mass spectrometry based metabolomics approaches, have started to show promise in providing rapid, sensitive and reproducible detection of Staphylococcus aureus antibiotic resistance. Here we performed a proof-of-concept study focused on the application of HPLC-MS/MS based targeted metabolic profiling for detecting and monitoring the bacterial metabolic profile changes in response to sub-lethal levels of methicillin exposure. One hundred seventy-seven targeted metabolites from over 20 metabolic pathways were specifically screened and one hundred and thirty metabolites from in vitro bacterial tests were confidently detected from both methicillin susceptible and methicillin resistant Staphylococcus aureus (MSSA and MRSA, respectively). The metabolic profiles can be used to distinguish the isogenic pairs of MSSA strains from MRSA strains, without or with sub-lethal levels of methicillin exposure. In addition, better separation between MSSA and MRSA strains can be achieved in the latter case using principal component analysis (PCA). Metabolite data from isogenic pairs of MSSA and MRSA strains were further compared without and with sub-lethal levels of methicillin exposure, with metabolic pathway analyses additionally performed. Both analyses suggested that the metabolic activities of MSSA strains were more susceptible to the perturbation of the sub-lethal levels of methicillin exposure compared to the MRSA strains. Copyright © 2016 Elsevier B.V. All rights reserved.

Utilization of peptide carrier system to improve intestinal absorption: targeting prolidase as a prodrug-converting enzyme

NASA Technical Reports Server (NTRS)

Bai, J. P.; Hu, M.; Subramanian, P.; Mosberg, H. I.; Amidon, G. L.

1992-01-01

The feasibility of targeting prolidase as a peptide prodrug-converting enzyme has been examined. The enzymatic hydrolysis by prolidase of substrates for the peptide transporter L-alpha-methyldopa-pro and several dipeptide analogues without an N-terminal alpha-amino group (phenylpropionylproline, phenylacetylproline, N-benzoylproline, and N-acetylproline) was investigated. The Michaelis-Menten parameters Km and Vmax for L-alpha-methyldopa-pro are 0.09 +/- 0.02 mM and 3.98 +/- 0.25 mumol/min/mg protein, respectively. However, no hydrolysis of the dipeptide analogues without an N-terminal alpha-amino group is observed, suggesting that an N-terminal alpha-amino group is required for prolidase activity. These results demonstrate that prolidase may serve as a prodrug-converting enzyme for the dipeptide-type prodrugs, utilizing the peptide carrier for transport of prodrugs into the mucosal cells and prolidase, a cytosolic enzyme, to release the drug. However, a free alpha-amino group appears to be necessary for prolidase hydrolysis.

Alterations in circadian and meal-induced gut peptide levels in lean and obese rats.

PubMed

Moghadam, Alexander A; Moran, Timothy H; Dailey, Megan J

2017-12-01

Alterations in gut hormone signaling are a likely contributing factor to the metabolic disturbances associated with overweight/obesity as they coordinate the timing of feeding behavior, absorption, and utilization of nutrients. These hormones are released in response to food intake, or follow a circadian or anticipatory pattern of secretion that is independent of nutrient stimulation. The aim of this study was to identify the degree to which high-fat diet-induced obesity would alter the daily rhythm of gut peptide plasma levels (glucagon-like peptide-1 [GLP-1], peptide YY [PYY], insulin or amylin [AMY]) or meal-induced levels in the middle of the light or dark cycle. Male Sprague-Dawley rats were fed a high-fat diet (OBESE) or chow (LEAN), implanted with jugular catheters, and blood samples were taken every 2 h throughout the light/dark cycle while freely feeding or after an Ensure liquid meal. We found that even when OBESE and LEAN animals ate the same kcals and have a similar pattern of food intake, there is a difference in both the levels and rhythm of plasma gut peptides. GLP-1 and PYY are higher during the light cycle in LEAN animals and AMY is higher in the OBESE group throughout the light/dark cycle. There was also a differential response of plasma gut signals after the Ensure meal, even though the composition and amount of intake of the meal were the same in both groups. These changes occur prior to the high-fat diet induced loss of glycemic control and may be a target for early intervention. Impact statement The aim of this study was to test if obesity would alter the daily rhythm of gut peptides or meal-induced levels in the middle of the light or dark cycle. We found that even when animals are eating the same amount (in kcal) of food that the obese animals have altered daily rhythms and meal-induced gut peptide levels. In particular, we are the first to show that obesity induces increases in peptide YY levels during the light cycle and amylin remains

Virtual Screening of Peptide and Peptidomimetic Fragments Targeted to Inhibit Bacterial Dithiol Oxidase DsbA.

PubMed

Duprez, Wilko; Bachu, Prabhakar; Stoermer, Martin J; Tay, Stephanie; McMahon, Róisín M; Fairlie, David P; Martin, Jennifer L

2015-01-01

Antibacterial drugs with novel scaffolds and new mechanisms of action are desperately needed to address the growing problem of antibiotic resistance. The periplasmic oxidative folding system in Gram-negative bacteria represents a possible target for anti-virulence antibacterials. By targeting virulence rather than viability, development of resistance and side effects (through killing host native microbiota) might be minimized. Here, we undertook the design of peptidomimetic inhibitors targeting the interaction between the two key enzymes of oxidative folding, DsbA and DsbB, with the ultimate goal of preventing virulence factor assembly. Structures of DsbB--or peptides--complexed with DsbA revealed key interactions with the DsbA active site cysteine, and with a hydrophobic groove adjacent to the active site. The present work aimed to discover peptidomimetics that target the hydrophobic groove to generate non-covalent DsbA inhibitors. The previously reported structure of a Proteus mirabilis DsbA active site cysteine mutant, in a non-covalent complex with the heptapeptide PWATCDS, was used as an in silico template for virtual screening of a peptidomimetic fragment library. The highest scoring fragment compound and nine derivatives were synthesized and evaluated for DsbA binding and inhibition. These experiments discovered peptidomimetic fragments with inhibitory activity at millimolar concentrations. Although only weakly potent relative to larger covalent peptide inhibitors that interact through the active site cysteine, these fragments offer new opportunities as templates to build non-covalent inhibitors. The results suggest that non-covalent peptidomimetics may need to interact with sites beyond the hydrophobic groove in order to produce potent DsbA inhibitors.

Quantitative PET Imaging with Novel HER3-Targeted Peptides Selected by Phage Display to Predict Androgen-Independent Prostate Cancer Progression

DTIC Science & Technology

2017-12-01

peptide in tumors that was linearly correlated with HER3 levels. Biodistribution analysis revealed low off-target accumulation and rapid clearance...Internal Lab 15-22 Dr. Larimer 5 Stock) Subtask 2: Correlate changes in peptide uptake with protein expression and cell signaling changes ex vivo...signal for each individual tumor was plotted against its corresponding HER3 protein level, the TBR correlated linearly with the amount of protein

Design, synthesis and in vitro evaluation of heterobivalent peptidic radioligands targeting both GRP- and VPAC1-Receptors concomitantly overexpressed on various malignancies - Is the concept feasible?

PubMed

Lindner, Simon; Fiedler, Luise; Wängler, Björn; Bartenstein, Peter; Schirrmacher, Ralf; Wängler, Carmen

2018-05-29

Radiolabeled heterobivalent peptidic ligands (HBPLs), being able to address different receptors, are highly interesting tumor imaging agents as they can offer multiple advantages over monovalent peptide receptor ligands. However, few examples of radiolabeled HBPLs have been described so far. One promising approach is the combination of gastrin-releasing peptide receptor (GRPR)- and vasoactive intestinal peptide receptor subtype 1 (VPAC 1 R)-targeting peptides into one single radioligand since gastrinomas, prostate and breast cancer have been shown to concomitantly or complementarily overexpress both receptors. Here we report the design and synthesis of different HBPLs, comprising a GRPR-binding (BBN 7-14 ) and a VPAC 1 R-targeting (PACAP-27) peptide. The heterodimers were varied with regard to the distance between the peptide binders and the steric rigidity of the systems. We radiolabeled the HBPLs 19-23 as well as their monomeric reference standards 26 and 27 with 68 Ga, achieving radiochemical yields and purities of 95-99% and non-optimized molar activities of 25-61 GBq/μmol. We tested the stability of the radioligands and further evaluated them in vitro regarding their uptake in different prostate carcinoma cell lines (PC-3, DU-145 and VCaP cells). We found that the heterobivalent substances [ 68 Ga]19 - [ 68 Ga]23 showed comparable uptakes into the tumor cells to those of the respective monomers [ 68 Ga]26 and [ 68 Ga]27, indicating that both peptides are still able to address their target receptors. Furthermore, the obtained results indicate that in case of overall low receptor densities, heterobivalent peptides surpass peptide monomers in tumor cell uptake. Most importantly, it could be shown by blocking studies that both peptide parts of the HBPL [ 68 Ga]19 contributed to tumor cell uptake in VCaP cells, expressing both receptor types. Thus, we describe here the first examples of HBPLs being able to address the GRPR as well as the VPAC 1 R and have the

Artificial Chemical Reporter Targeting Strategy Using Bioorthogonal Click Reaction for Improving Active-Targeting Efficiency of Tumor.

PubMed

Yoon, Hong Yeol; Shin, Min Lee; Shim, Man Kyu; Lee, Sangmin; Na, Jin Hee; Koo, Heebeom; Lee, Hyukjin; Kim, Jong-Ho; Lee, Kuen Yong; Kim, Kwangmeyung; Kwon, Ick Chan

2017-05-01

Biological ligands such as aptamer, antibody, glucose, and peptide have been widely used to bind specific surface molecules or receptors in tumor cells or subcellular structures to improve tumor-targeting efficiency of nanoparticles. However, this active-targeting strategy has limitations for tumor targeting due to inter- and intraheterogeneity of tumors. In this study, we demonstrated an alternative active-targeting strategy using metabolic engineering and bioorthogonal click reaction to improve tumor-targeting efficiency of nanoparticles. We observed that azide-containing chemical reporters were successfully generated onto surface glycans of various tumor cells such as lung cancer (A549), brain cancer (U87), and breast cancer (BT-474, MDA-MB231, MCF-7) via metabolic engineering in vitro. In addition, we compared tumor targeting of artificial azide reporter with bicyclononyne (BCN)-conjugated glycol chitosan nanoparticles (BCN-CNPs) and integrin α v β 3 with cyclic RGD-conjugated CNPs (cRGD-CNPs) in vitro and in vivo. Fluorescence intensity of azide-reporter-targeted BCN-CNPs in tumor tissues was 1.6-fold higher and with a more uniform distribution compared to that of cRGD-CNPs. Moreover, even in the isolated heterogeneous U87 cells, BCN-CNPs could bind artificial azide reporters on tumor cells more uniformly (∼92.9%) compared to cRGD-CNPs. Therefore, the artificial azide-reporter-targeting strategy can be utilized for targeting heterogeneous tumor cells via bioorthogonal click reaction and may provide an alternative method of tumor targeting for further investigation in cancer therapy.

Thyroid Hormone Regulation of Metabolism

PubMed Central

Mullur, Rashmi; Liu, Yan-Yun

2014-01-01

Thyroid hormone (TH) is required for normal development as well as regulating metabolism in the adult. The thyroid hormone receptor (TR) isoforms, α and β, are differentially expressed in tissues and have distinct roles in TH signaling. Local activation of thyroxine (T4), to the active form, triiodothyronine (T3), by 5′-deiodinase type 2 (D2) is a key mechanism of TH regulation of metabolism. D2 is expressed in the hypothalamus, white fat, brown adipose tissue (BAT), and skeletal muscle and is required for adaptive thermogenesis. The thyroid gland is regulated by thyrotropin releasing hormone (TRH) and thyroid stimulating hormone (TSH). In addition to TRH/TSH regulation by TH feedback, there is central modulation by nutritional signals, such as leptin, as well as peptides regulating appetite. The nutrient status of the cell provides feedback on TH signaling pathways through epigentic modification of histones. Integration of TH signaling with the adrenergic nervous system occurs peripherally, in liver, white fat, and BAT, but also centrally, in the hypothalamus. TR regulates cholesterol and carbohydrate metabolism through direct actions on gene expression as well as cross-talk with other nuclear receptors, including peroxisome proliferator-activated receptor (PPAR), liver X receptor (LXR), and bile acid signaling pathways. TH modulates hepatic insulin sensitivity, especially important for the suppression of hepatic gluconeogenesis. The role of TH in regulating metabolic pathways has led to several new therapeutic targets for metabolic disorders. Understanding the mechanisms and interactions of the various TH signaling pathways in metabolism will improve our likelihood of identifying effective and selective targets. PMID:24692351

Immunocytochemical demonstration of glucagon-like peptides in Mytilus edulis cerebral ganglia and an in vitro effect of vertebrate glucagon on glycogen metabolism.

PubMed

Kellner, K; Heude-Berthelin, C; Mathieu, M

2002-04-01

Immunological detection of glucagon-like peptides was performed in the cerebral ganglia of the mussel Mytilus edulis using an anti-vertebrate glucagon antibody. Two clusters of positive neurosecretory cells were observed, as well as stained nervous fibers. The effect of vertebrate glucagon on glucose incorporation into glycogen of reserve cells was tested using an in vitro microplate bioassay. Optimal incubation conditions were previously defined and an inhibitory effect of porcine glucagon was obtained for concentrations ranging from 10(-6) to 10(-9)M. It is postulated that the glucagon-like peptide may be implicated in the regulation of glucose metabolism in bivalves.

Phage selection of peptide "microantibodies".

PubMed

Fujiwara, Daisuke; Fujii, Ikuo

2013-01-01

A bioactive peptide capable of inhibiting protein-protein interactions has the potential to be a molecular tool for biological studies and a therapeutic by disrupting aberrant interactions involved in diseases. We have developed combinatorial libraries of peptides with helix-loop-helix structure, from which the isolated peptides have the constrained structure to reduce entropy costs in binding, resulting in high binding affinities for target molecules. Previously, we designed a de novo peptide of helix-loop-helix structure that we termed a "microantibody." Using the microantibody as a library scaffold, we have constructed a phage-display library to successfully isolate molecular-targeting peptides against a cytokine receptor (granulocyte colony-stimulating factor receptor), a protein kinase (Aurora-A), and a ganglioside (GM1). Protocols in this article describe a general procedure for the library construction and the library screening.

In silico search of energy metabolism inhibitors for alternative leishmaniasis treatments.

PubMed

Silva, Lourival A; Vinaud, Marina C; Castro, Ana Maria; Cravo, Pedro Vítor L; Bezerra, José Clecildo B

2015-01-01

Leishmaniasis is a complex disease that affects mammals and is caused by approximately 20 distinct protozoa from the genus Leishmania. Leishmaniasis is an endemic disease that exerts a large socioeconomic impact on poor and developing countries. The current treatment for leishmaniasis is complex, expensive, and poorly efficacious. Thus, there is an urgent need to develop more selective, less expensive new drugs. The energy metabolism pathways of Leishmania include several interesting targets for specific inhibitors. In the present study, we sought to establish which energy metabolism enzymes in Leishmania could be targets for inhibitors that have already been approved for the treatment of other diseases. We were able to identify 94 genes and 93 Leishmania energy metabolism targets. Using each gene's designation as a search criterion in the TriTrypDB database, we located the predicted peptide sequences, which in turn were used to interrogate the DrugBank, Therapeutic Target Database (TTD), and PubChem databases. We identified 44 putative targets of which 11 are predicted to be amenable to inhibition by drugs which have already been approved for use in humans for 11 of these targets. We propose that these drugs should be experimentally tested and potentially used in the treatment of leishmaniasis.

Human lactoferricin derived di-peptides deploying loop structures induce apoptosis specifically in cancer cells through targeting membranous phosphatidylserine.

PubMed

Riedl, Sabrina; Leber, Regina; Rinner, Beate; Schaider, Helmut; Lohner, Karl; Zweytick, Dagmar

2015-11-01

Host defense-derived peptides have emerged as a novel strategy for the development of alternative anticancer therapies. In this study we report on characteristic features of human lactoferricin (hLFcin) derivatives which facilitate specific killing of cancer cells of melanoma, glioblastoma and rhabdomyosarcoma compared with non-specific derivatives and the synthetic peptide RW-AH. Changes in amino acid sequence of hLFcin providing 9-11 amino acids stretched derivatives LF11-316, -318 and -322 only yielded low antitumor activity. However, the addition of the repeat (di-peptide) and the retro-repeat (di-retro-peptide) sequences highly improved cancer cell toxicity up to 100% at 20 μM peptide concentration. Compared to the complete parent sequence hLFcin the derivatives showed toxicity on the melanoma cell line A375 increased by 10-fold and on the glioblastoma cell line U-87mg by 2-3-fold. Reduced killing velocity, apoptotic blebbing, activation of caspase 3/7 and formation of apoptotic DNA fragments proved that the active and cancer selective peptides, e.g. R-DIM-P-LF11-322, trigger apoptosis, whereas highly active, though non-selective peptides, such as DIM-LF11-318 and RW-AH seem to kill rapidly via necrosis inducing membrane lyses. Structural studies revealed specific toxicity on cancer cells by peptide derivatives with loop structures, whereas non-specific peptides comprised α-helical structures without loop. Model studies with the cancer membrane mimic phosphatidylserine (PS) gave strong evidence that PS only exposed by cancer cells is an important target for specific hLFcin derivatives. Other negatively charged membrane exposed molecules as sialic acid, heparan and chondroitin sulfate were shown to have minor impact on peptide activity. Copyright © 2015. Published by Elsevier B.V.

Targeting Sulfotransferase (SULT) 2B1b as a Regulator of Cholesterol Metabolism in Prostate Cancer

DTIC Science & Technology

2015-10-01

AWARD NUMBER: W81XWH-14-1-0588 TITLE: Targeting Sulfotransferase (SULT) 2B1b as a regulator of Cholesterol Metabolism in Prostate Cancer...October 2015 30Sep2014 - 29Sep2015 W81XWH-14-1-0588Targeting Sulfotransferase (SULT) 2B1b as a regulator of Cholesterol Metabolism in Prostate...epidemiological and experimental evidence establishes alterations in cholesterol metabolism as a key driver of prostate cancer (PCa) aggressiveness

Use of LDL receptor-targeting peptide vectors for in vitro and in vivo cargo transport across the blood-brain barrier.

PubMed

Molino, Yves; David, Marion; Varini, Karine; Jabès, Françoise; Gaudin, Nicolas; Fortoul, Aude; Bakloul, Karima; Masse, Maxime; Bernard, Anne; Drobecq, Lucile; Lécorché, Pascaline; Temsamani, Jamal; Jacquot, Guillaume; Khrestchatisky, Michel

2017-05-01

The blood-brain barrier (BBB) prevents the entry of many drugs into the brain and, thus, is a major obstacle in the treatment of CNS diseases. There is some evidence that the LDL receptor (LDLR) is expressed at the BBB and may participate in the transport of endogenous ligands from blood to brain, a process referred to as receptor-mediated transcytosis. We previously described a family of peptide vectors that were developed to target the LDLR. In the present study, in vitro BBB models that were derived from wild-type and LDLR-knockout animals ( ldlr -/- ) were used to validate the specific LDLR-dependent transcytosis of LDL via a nondegradative route. We next showed that LDLR-targeting peptide vectors, whether in fusion or chemically conjugated to an Ab Fc fragment, promote binding to apical LDLR and transendothelial transfer of the Fc fragment across BBB monolayers via the same route as LDL. Finally, we demonstrated in vivo that LDLR significantly contributes to the brain uptake of vectorized Fc. We thus provide further evidence that LDLR is a relevant receptor for CNS drug delivery via receptor-mediated transcytosis and that the peptide vectors we developed have the potential to transport drugs, including proteins or Ab based, across the BBB.-Molino, Y., David, M., Varini, K., Jabès, F., Gaudin, N., Fortoul, A., Bakloul, K., Masse, M., Bernard, A., Drobecq, L., Lécorché, P., Temsamani, J., Jacquot, G., Khrestchatisky, M. Use of LDL receptor-targeting peptide vectors for in vitro and in vivo cargo transport across the blood-brain barrier. © FASEB.

Peptides, polypeptides and peptide-polymer hybrids as nucleic acid carriers.

PubMed

Ahmed, Marya

2017-10-24

Cell penetrating peptides (CPPs), and protein transduction domains (PTDs) of viruses and other natural proteins serve as a template for the development of efficient peptide based gene delivery vectors. PTDs are sequences of acidic or basic amphipathic amino acids, with superior membrane trespassing efficacies. Gene delivery vectors derived from these natural, cationic and cationic amphipathic peptides, however, offer little flexibility in tailoring the physicochemical properties of single chain peptide based systems. Owing to significant advances in the field of peptide chemistry, synthetic mimics of natural peptides are often prepared and have been evaluated for their gene expression, as a function of amino acid functionalities, architecture and net cationic content of peptide chains. Moreover, chimeric single polypeptide chains are prepared by a combination of multiple small natural or synthetic peptides, which imparts distinct physiological properties to peptide based gene delivery therapeutics. In order to obtain multivalency and improve the gene delivery efficacies of low molecular weight cationic peptides, bioactive peptides are often incorporated into a polymeric architecture to obtain novel 'polymer-peptide hybrids' with improved gene delivery efficacies. Peptide modified polymers prepared by physical or chemical modifications exhibit enhanced endosomal escape, stimuli responsive degradation and targeting efficacies, as a function of physicochemical and biological activities of peptides attached onto a polymeric scaffold. The focus of this review is to provide comprehensive and step-wise progress in major natural and synthetic peptides, chimeric polypeptides, and peptide-polymer hybrids for nucleic acid delivery applications.

Neuroactive Peptides as Putative Mediators of Antiepileptic Ketogenic Diets

PubMed Central

Giordano, Carmela; Marchiò, Maddalena; Timofeeva, Elena; Biagini, Giuseppe

2014-01-01

Various ketogenic diet (KD) therapies, including classic KD, medium chain triglyceride administration, low glycemic index treatment, and a modified Atkins diet, have been suggested as useful in patients affected by pharmacoresistant epilepsy. A common goal of these approaches is to achieve an adequate decrease in the plasma glucose level combined with ketogenesis, in order to mimic the metabolic state of fasting. Although several metabolic hypotheses have been advanced to explain the anticonvulsant effect of KDs, including changes in the plasma levels of ketone bodies, polyunsaturated fatty acids, and brain pH, direct modulation of neurotransmitter release, especially purinergic (i.e., adenosine) and γ-aminobutyric acidergic neurotransmission, was also postulated. Neuropeptides and peptide hormones are potent modulators of synaptic activity, and their levels are regulated by metabolic states. This is the case for neuroactive peptides such as neuropeptide Y, galanin, cholecystokinin, and peptide hormones such as leptin, adiponectin, and growth hormone-releasing peptides (GHRPs). In particular, the GHRP ghrelin and its related peptide des-acyl ghrelin are well-known controllers of energy homeostasis, food intake, and lipid metabolism. Notably, ghrelin has also been shown to regulate the neuronal excitability and epileptic activation of neuronal networks. Several lines of evidence suggest that GHRPs are upregulated in response to starvation and, particularly, in patients affected by anorexia and cachexia, all conditions in which also ketone bodies are upregulated. Moreover, starvation and anorexia nervosa are accompanied by changes in other peptide hormones such as adiponectin, which has received less attention. Adipocytokines such as adiponectin have also been involved in modulating epileptic activity. Thus, neuroactive peptides whose plasma levels and activity change in the presence of ketogenesis might be potential candidates for elucidating the neurohormonal

Improved Glucose Control and Reduced Body Weight in Rodents with Dual Mechanism of Action Peptide Hybrids

PubMed Central

Trevaskis, James L.; Mack, Christine M.; Sun, Chengzao; Soares, Christopher J.; D’Souza, Lawrence J.; Levy, Odile E.; Lewis, Diane Y.; Jodka, Carolyn M.; Tatarkiewicz, Krystyna; Gedulin, Bronislava; Gupta, Swati; Wittmer, Carrie; Hanley, Michael; Forood, Bruce; Parkes, David G.; Ghosh, Soumitra S.

2013-01-01

Combination therapy is being increasingly used as a treatment paradigm for metabolic diseases such as diabetes and obesity. In the peptide therapeutics realm, recent work has highlighted the therapeutic potential of chimeric peptides that act on two distinct receptors, thereby harnessing parallel complementary mechanisms to induce additive or synergistic benefit compared to monotherapy. Here, we extend this hypothesis by linking a known anti-diabetic peptide with an anti-obesity peptide into a novel peptide hybrid, which we termed a phybrid. We report on the synthesis and biological activity of two such phybrids (AC164204 and AC164209), comprised of a glucagon-like peptide-1 receptor (GLP1-R) agonist, and exenatide analog, AC3082, covalently linked to a second generation amylin analog, davalintide. Both molecules acted as full agonists at their cognate receptors in vitro, albeit with reduced potency at the calcitonin receptor indicating slightly perturbed amylin agonism. In obese diabetic Lepob/Lep ob mice sustained infusion of AC164204 and AC164209 reduced glucose and glycated haemoglobin (HbA1c) equivalently but induced greater weight loss relative to exenatide administration alone. Weight loss was similar to that induced by combined administration of exenatide and davalintide. In diet-induced obese rats, both phybrids dose-dependently reduced food intake and body weight to a greater extent than exenatide or davalintide alone, and equal to co-infusion of exenatide and davalintide. Phybrid-mediated and exenatide + davalintide-mediated weight loss was associated with reduced adiposity and preservation of lean mass. These data are the first to provide in vivo proof-of-concept for multi-pathway targeting in metabolic disease via a peptide hybrid, demonstrating that this approach is as effective as co-administration of individual peptides. PMID:24167604

Peptide-Like Molecules (PLMs): A Journey from Peptide Bond Isosteres to Gramicidin S Mimetics and Mitochondrial Targeting Agents

PubMed Central

Wipf, Peter; Xiao, Jingbo; Stephenson, Corey R. J.

2010-01-01

Peptides are natural ligands and substrates for receptors and enzymes and exhibit broad physiological effects. However, their use as therapeutic agents often suffers from poor bioavailability and insufficient membrane permeability. The success of peptide mimicry hinges on the ability of bioisosteres, in particular peptide bond replacements, to adopt suitable secondary structures relevant to peptide strands and position functional groups in equivalent space. This perspective highlights past and ongoing studies in our group that involve new methods development as well as specific synthetic library preparations and applications in chemical biology, with the goal to enhance the use of alkene and cyclopropane peptide bond isosteres. PMID:20725595

The Triangle of Death in Alzheimer's Disease Brain: The Aberrant Cross-Talk Among Energy Metabolism, Mammalian Target of Rapamycin Signaling, and Protein Homeostasis Revealed by Redox Proteomics.

PubMed

Di Domenico, Fabio; Barone, Eugenio; Perluigi, Marzia; Butterfield, D Allan

2017-03-10

Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder and represents one of the most disabling conditions. AD shares many features in common with systemic insulin resistance diseases, suggesting that it can be considered as a metabolic disease, characterized by reduced insulin-stimulated growth and survival signaling, increased oxidative stress (OS), proinflammatory cytokine activation, mitochondrial dysfunction, impaired energy metabolism, and altered protein homeostasis. Recent Advances: Reduced glucose utilization and energy metabolism in AD have been associated with the buildup of amyloid-β peptide and hyperphosphorylated tau, increased OS, and the accumulation of unfolded/misfolded proteins. Mammalian target of rapamycin (mTOR), which is aberrantly activated in AD since early stages, plays a key role during AD neurodegeneration by, on one side, inhibiting insulin signaling as a negative feedback mechanism and, on the other side, regulating protein homeostasis (synthesis/clearance). It is likely that the concomitant and mutual alterations of energy metabolism-mTOR signaling-protein homeostasis might represent a self-sustaining triangle of harmful events that trigger the degeneration and death of neurons and the development and progression of AD. Intriguingly, the altered cross-talk between the components of such a triangle of death, beyond altering the redox homeostasis of the neuron, is further exacerbated by increased levels of OS that target and impair key components of the pathways involved. Redox proteomic studies in human samples and animal models of AD-like dementia led to identification of oxidatively modified components of the pathways composing the triangle of death, therefore revealing the crucial role of OS in fueling this aberrant vicious cycle. The identification of compounds able to restore the function of the pathways targeted by oxidative damage might represent a valuable therapeutic approach to slow or delay AD. Antioxid

Targeting cancer stem-like cells in glioblastoma and colorectal cancer through metabolic pathways.

PubMed

Kahlert, U D; Mooney, S M; Natsumeda, M; Steiger, H-J; Maciaczyk, J

2017-01-01

Cancer stem-like cells (CSCs) are thought to be the main cause of tumor occurrence, progression and therapeutic resistance. Strong research efforts in the last decade have led to the development of several tailored approaches to target CSCs with some very promising clinical trials underway; however, until now no anti-CSC therapy has been approved for clinical use. Given the recent improvement in our understanding of how onco-proteins can manipulate cellular metabolic networks to promote tumorigenesis, cancer metabolism research may well lead to innovative strategies to identify novel regulators and downstream mediators of CSC maintenance. Interfering with distinct stages of CSC-associated metabolics may elucidate novel, more efficient strategies to target this highly malignant cell population. Here recent discoveries regarding the metabolic properties attributed to CSCs in glioblastoma (GBM) and malignant colorectal cancer (CRC) were summarized. The association between stem cell markers, the response to hypoxia and other environmental stresses including therapeutic insults as well as developmentally conserved signaling pathways with alterations in cellular bioenergetic networks were also discussed. The recent developments in metabolic imaging to identify CSCs were also summarized. This summary should comprehensively update basic and clinical scientists on the metabolic traits of CSCs in GBM and malignant CRC. © 2016 UICC.

Poly(NIPAm-AMPS) nanoparticles for targeted delivery of anti-inflammatory cell penetrating peptides

NASA Astrophysics Data System (ADS)

Bartlett, Rush Lloyd, II

Inflammatory diseases such as osteoarthritis and rheumatoid arthritis cause $127.8 billion in US healthcare expenditures each year and are the cause of disability for 27% of disabled persons in the United States. Current treatment options rarely halt disease progression and often result in significant unwanted and debilitating side effects. Our laboratory has previously developed a family of cell penetrating peptides (CPPs) which inhibit the activity of mitogen activated protein kinase activate protein kinase 2 (MK2). MK2 mediates the inflammatory response by activating Tristetraprline (TTP). Once activated, TTP rapidly stabilizes AU rich regions of pro-inflammatory cytokine mRNA which allows translation of pro-inflammatory cytokines to occur. Blocking MK2 with our labs CPPs yields a decrease in inflammatory activity but CPPs by are highly non specific and prone to rapid enzymatic degradation in vivo.. In order to increase the potency of MK2 inhibiting CPPs we have developed a novel nanoparticle drug carrier composed of poly(N-isopropylacrylamide-co-2-acrylamido-2-methyl-1-propanesulfonic acid). This drug carrier has been shown to have preliminary efficacy in vitro and ex vivo for suppressing pro-inflammatory cytokine production when releasing CPPs. This thesis will present progress made on three aims: Specific Aim 1) Create and validate a NIPAm based drug delivery system that mimics the binding and release previously observed between cell penetrating peptides and glycosaminoglycans. Specific Aim 2) Engineer degradability into poly(NIPAm-AMPS) nanoparticles to enable more drug to be released and qualify that system in vitro. Specific Aim 3) Validate poly(NIPAm-AMPS) nanoparticles for targeted drug delivery in an ex vivo inflammatory model. Overall we have developed a novel anionic nanoparticle system that is biocompatible and efficient at loading and releasing cell penetrating peptides to inflamed tissue. Once loaded with a CPP the nanoparticle drug complex is

Identification of chondrocyte-binding peptides by phage display.

PubMed

Cheung, Crystal S F; Lui, Julian C; Baron, Jeffrey

2013-07-01

As an initial step toward targeting cartilage tissue for potential therapeutic applications, we sought cartilage-binding peptides using phage display, a powerful technology for selection of peptides that bind to molecules of interest. A library of phage displaying random 12-amino acid peptides was iteratively incubated with cultured chondrocytes to select phage that bind cartilage. The resulting phage clones demonstrated increased affinity to chondrocytes by ELISA, when compared to a wild-type, insertless phage. Furthermore, the selected phage showed little preferential binding to other cell types, including primary skin fibroblast, myocyte and hepatocyte cultures, suggesting a tissue-specific interaction. Immunohistochemical staining revealed that the selected phage bound chondrocytes themselves and the surrounding extracellular matrix. FITC-tagged peptides were synthesized based on the sequence of cartilage-binding phage clones. These peptides, but not a random peptide, bound cultured chondrocytes, and extracelluar matrix. In conclusion, using phage display, we identified peptide sequences that specifically target chondrocytes. We anticipate that such peptides may be coupled to therapeutic molecules to provide targeted treatment for cartilage disorders. Copyright © 2013 Orthopaedic Research Society.

Retro-inverso d-peptide-modified hyaluronic acid/bioreducible hyperbranched poly(amido amine)/pDNA core-shell ternary nanoparticles for the dual-targeted delivery of short hairpin RNA-encoding plasmids.

PubMed

Gu, Jijin; Chen, Xinyi; Fang, Xiaoling; Sha, Xianyi

2017-07-15

The active targeting of gene carriers is a powerful strategy for improving tumour-specific delivery and therapy. Although numerous l-peptide ligands play significant roles in the active targeting of nanomedicine, retro-inverso d-peptides have been explored as targeting ligands due to their superior stability and bioactivity in vivo. In this study, retro-inverso d-peptide (RIF7)-modified hyaluronic acid (HA)/bioreducible hyperbranched poly(amido amine) (RHB)/plasmid DNA (pDNA) ternary nanoparticles were successfully developed using the layer-by-layer method for the CD44-positive tumour-specific delivery of short hairpin RNA (shRNA)-encoding pDNA through the combination of the Anxa1 (tumour vasculature) and CD44 (tumour cell-surface) receptors, which mediated the dual targeting. The potential of these newly designed nanoparticles was evaluated by examining the efficacy of their cellular uptake and transfection in cell monolayers, tumour spheroids, and malignant xenograft animal models. With negligible cytotoxicity, the spherical-shaped RIF7-HA/RHB/pDNA nanoparticles were the direct result of an electrostatic complex that had efficiently targeted CD44-positive tumour delivery, penetration, and cellular uptake in vitro. The nanoparticles showed excellent target-specific gene transfection even in the presence of serum. The in vivo therapeutic effect of RIF7-HA/RHB/pDNA-shRNA nanoparticle-mediated shRNA targeting of the Cyclin gene (shCyclin) was evaluated in tumour-bearing mice. The RIF7-HA/RHB/pDNA-shCyclin nanoparticles significantly increased the survival time of tumour-bearing mice and substantially reduced tumour growth due to their extremely specific tumour-targeting activity. These results suggested that the combination of HA and retro-inverso peptide RIF7 significantly increased the therapeutic effect of pDNA-shCyclin-loaded nanoparticles for CD44-positive tumours. Thus, RIF7-HA-mediated multi-target ternary gene vectors are an efficient and promising strategy

Metabolic analysis of radioresistant medulloblastoma stem-like clones and potential therapeutic targets.

PubMed

Sun, Lue; Moritake, Takashi; Ito, Kazuya; Matsumoto, Yoshitaka; Yasui, Hironobu; Nakagawa, Hidehiko; Hirayama, Aki; Inanami, Osamu; Tsuboi, Koji

2017-01-01

Medulloblastoma is a fatal brain tumor in children, primarily due to the presence of treatment-resistant medulloblastoma stem cells. The energy metabolic pathway is a potential target of cancer therapy because it is often different between cancer cells and normal cells. However, the metabolic properties of medulloblastoma stem cells, and whether specific metabolic pathways are essential for sustaining their stem cell-like phenotype and radioresistance, remain unclear. We have established radioresistant medulloblastoma stem-like clones (rMSLCs) by irradiation of the human medulloblastoma cell line ONS-76. Here, we assessed reactive oxygen species (ROS) production, mitochondria function, oxygen consumption rate (OCR), energy state, and metabolites of glycolysis and tricarboxylic acid cycle in rMSLCs and parental cells. rMSLCs showed higher lactate production and lower oxygen consumption rate than parental cells. Additionally, rMSLCs had low mitochondria mass, low endogenous ROS production, and existed in a low-energy state. Treatment with the metabolic modifier dichloroacetate (DCA) resulted in mitochondria dysfunction, glycolysis inhibition, elongated mitochondria morphology, and increased ROS production. DCA also increased radiosensitivity by suppression of the DNA repair capacity through nuclear oxidization and accelerated the generation of acetyl CoA to compensate for the lack of ATP. Moreover, treatment with DCA decreased cancer stem cell-like characters (e.g., CD133 positivity and sphere-forming ability) in rMSLCs. Together, our findings provide insights into the specific metabolism of rMSLCs and illuminate potential metabolic targets that might be exploited for therapeutic benefit in medulloblastoma.

Germline TRAV5D-4 T-Cell Receptor Sequence Targets a Primary Insulin Peptide of NOD Mice

PubMed Central

Nakayama, Maki; Castoe, Todd; Sosinowski, Tomasz; He, XiangLing; Johnson, Kelly; Haskins, Kathryn; Vignali, Dario A.A.; Gapin, Laurent; Pollock, David; Eisenbarth, George S.

2012-01-01

There is accumulating evidence that autoimmunity to insulin B chain peptide, amino acids 9–23 (insulin B:9–23), is central to development of autoimmune diabetes of the NOD mouse model. We hypothesized that enhanced susceptibility to autoimmune diabetes is the result of targeting of insulin by a T-cell receptor (TCR) sequence commonly encoded in the germline. In this study, we aimed to demonstrate that a particular Vα gene TRAV5D-4 with multiple junction sequences is sufficient to induce anti-islet autoimmunity by studying retrogenic mouse lines expressing α-chains with different Vα TRAV genes. Retrogenic NOD strains expressing Vα TRAV5D-4 α-chains with many different complementarity determining region (CDR) 3 sequences, even those derived from TCRs recognizing islet-irrelevant molecules, developed anti-insulin autoimmunity. Induction of insulin autoantibodies by TRAV5D-4 α-chains was abrogated by the mutation of insulin peptide B:9–23 or that of two amino acid residues in CDR1 and 2 of the TRAV5D-4. TRAV13–1, the human ortholog of murine TRAV5D-4, was also capable of inducing in vivo anti-insulin autoimmunity when combined with different murine CDR3 sequences. Targeting primary autoantigenic peptides by simple germline-encoded TCR motifs may underlie enhanced susceptibility to the development of autoimmune diabetes. PMID:22315318

Investigating Endogenous Peptides and Peptidases using Peptidomics

PubMed Central

Tinoco, Arthur D.; Saghatelian, Alan

2012-01-01

Rather than simply being protein degradation products, peptides have proven to be important bioactive molecules. Bioactive peptides act as hormones, neurotransmitters and antimicrobial agents in vivo. The dysregulation of bioactive peptide signaling is also known to be involved in disease, and targeting peptide hormone pathways has been successful strategy in the development of novel therapeutics. The importance of bioactive peptides in biology has spurred research to elucidate the function and regulation of these molecules. Classical methods for peptide analysis have relied on targeted immunoassays, but certain scientific questions necessitated a broader and more detailed view of the peptidome–all the peptides in a cell, tissue or organism. In this review we discuss how peptidomics has emerged to fill this need through the application of advanced liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods that provide unique insights into peptide activity and regulation. PMID:21786763

RGD peptide-mediated chitosan-based polymeric micelles targeting delivery for integrin-overexpressing tumor cells.

PubMed

Cai, Li-Li; Liu, Ping; Li, Xi; Huang, Xuan; Ye, Yi-Qing; Chen, Feng-Ying; Yuan, Hong; Hu, Fu-Qiang; Du, Yong-Zhong

2011-01-01

Solid tumors need new blood vessels to feed and nourish them as well as to allow tumor cells to escape into the circulation and lodge in other organs, which is termed "angiogenesis." Some tumor cells within solid tumors can overexpress integrins α(v)β(3) and α(v)β(5), which can specifically recognize the peptide motif Arg-Gly-Asp (RGD). Thus, the targeting of RGD-modified micelles to tumor vasculature is a promising strategy for tumor-targeting treatment. RGD peptide (GSSSGRGDSPA) was coupled to poly(ethylene glycol)-modified stearic acid-grafted chitosan (PEG-CS-SA) micelles via chemical reaction in the presence of N,N'-Disuccinimidyl carbonate. The critical micelle concentration of the polymeric micelles was determined by measuring the fluorescence intensity of pyrene as a fluorescent probe. The micelle size, size distribution, and zeta potential were measured by light scattering and electrophoretic mobility. Doxorubicin (DOX) was chosen as a model anticancer drug to investigate the drug entrapment efficiency, in vitro drug-release profile, and in vitro antitumor activities of drug-loaded RGD-PEG-CS-SA micelles in cells that overexpress integrins (α(ν)β(3) and α(ν)β(5)) and integrin-deficient cells. Using DOX as a model drug, the drug encapsulation efficiency could reach 90%, and the in vitro drug-release profiles suggested that the micelles could be used as a controlled-release carrier for the hydrophobic drug. Qualitative and quantitative analysis of cellular uptake indicated that RGD-modified micelles could significantly increase the DOX concentration in integrin-overexpressing human hepatocellular carcinoma cell line (BEL-7402), but not in human epithelial carcinoma cell line (Hela). The competitive cellular-uptake test showed that the cellular uptake of RGD-modified micelles in BEL-7402 cells was significantly inhibited in the presence of excess free RGD peptides. In vitro cytotoxicity tests demonstrated DOX-loaded RGD-modified micelles could

Fetal metabolic influences of neonatal anthropometry and adiposity.

PubMed

Donnelly, Jean M; Lindsay, Karen L; Walsh, Jennifer M; Horan, Mary; Molloy, Eleanor J; McAuliffe, Fionnuala M

2015-11-10

Large for gestational age infants have an increased risk of obesity, cardiovascular and metabolic complications during life. Knowledge of the key predictive factors of neonatal adiposity is required to devise targeted antenatal interventions. Our objective was to determine the fetal metabolic factors that influence regional neonatal adiposity in a cohort of women with previous large for gestational age offspring. Data from the ROLO [Randomised COntrol Trial of LOw Glycaemic Index in Pregnancy] study were analysed in the ROLO Kids study. Neonatal anthropometric and skinfold measurements were compared with fetal leptin and C-peptide results from cord blood in 185 cases. Analyses were performed to examine the association between these metabolic factors and birthweight, anthropometry and markers of central and generalised adiposity. Fetal leptin was found to correlate with birthweight, general adiposity and multiple anthropometric measurements. On multiple regression analysis, fetal leptin remained significantly associated with adiposity, independent of gender, maternal BMI, gestational age or study group assignment, while fetal C-peptide was no longer significant. Fetal leptin may be an important predictor of regional neonatal adiposity. Interventional studies are required to assess the impact of neonatal adiposity on the subsequent risk of childhood obesity and to determine whether interventions which reduce circulating leptin levels have a role to play in improving neonatal adiposity measures.

Targeted mitochondrial uncoupling beyond UCP1 - The fine line between death and metabolic health.

PubMed

Ost, Mario; Keipert, Susanne; Klaus, Susanne

2017-03-01

In the early 1930s, the chemical uncoupling agent 2,4-dinitrophenol (DNP) was promoted for the very first time as a powerful and effective weight loss pill but quickly withdrawn from the market due to its lack of tissue-selectivity with resulting dangerous side effects, including hyperthermia and death. Today, novel mitochondria- or tissue-targeted chemical uncouplers with higher safety and therapeutic values are under investigation in order to tackle obesity, diabetes and fatty liver disease. Moreover, in the past 20 years, transgenic mouse models were generated to understand the molecular and metabolic consequences of targeted uncoupling, expressing functional uncoupling protein 1 (UCP1) ectopically in white adipose tissue or skeletal muscle. Similar to the action of chemical mitochondrial uncouplers, UCP1 protein dissipates the proton gradient across the inner mitochondrial membrane, thus allowing maximum activity of the respiratory chain and compensatory increase in oxygen consumption, uncoupled from ATP synthesis. Consequently, targeted mitochondrial uncoupling in adipose tissue and skeletal muscle of UCP1-transgenic mice increased substrate metabolism and ameliorates obesity, hypertriglyceridemia and insulin resistance. Further, muscle-specific decrease in mitochondrial efficiency promotes a cell-autonomous and cell-non-autonomous adaptive metabolic remodeling with increased oxidative stress tolerance. This review provides an overview of novel chemical uncouplers as well as the metabolic consequences and adaptive processes of targeted mitochondrial uncoupling on metabolic health and survival. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

A metabolic network approach for the identification and prioritization of antimicrobial drug targets

PubMed Central

Chavali, Arvind K.; D’Auria, Kevin M.; Hewlett, Erik L.; Pearson, Richard D.; Papin, Jason A.

2012-01-01

For many infectious diseases, novel treatment options are needed to address problems with cost, toxicity and resistance to current drugs. Systems biology tools can be used to gain valuable insight into pathogenic processes and aid in expediting drug discovery. In the past decade, constraint-based modeling of genome-scale metabolic networks has become widely used. Focusing on pathogen metabolic networks, we review in silico strategies to identify effective drug targets, and we highlight recent successes as well as limitations associated with such computational analyses. We further discuss how accounting for the host environment and even targeting the host may offer new therapeutic options. These systems-level approaches are beginning to provide novel avenues for drug targeting against infectious agents. PMID:22300758

Improved Detection of HER2 by a Quasi-Targeted Proteomics Approach Using Aptamer-Peptide Probe and Liquid Chromatography-Tandem Mass Spectrometry.

PubMed

Zhou, Weixian; Xu, Feifei; Li, Danni; Chen, Yun

2018-03-01

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer is a particularly aggressive type of the disease. To date, much evidence has indicated that accurate HER2 status detection is crucial for prognosis and treatment strategy selection. Thus, bioanalytical techniques for early and accurate detection of HER2 have the potential to improve patient care. Currently, the widely used immunohistochemical staining normally has problems with reproducibility and lack of standardization, resulting in poor concordance between laboratories. Aptamers are a good alternative, but the extent of their use in quantitative analysis of HER2 is limited because of the lack of effective detection methods. We developed a quasi-targeted proteomics assay and converted the HER2 signal into the mass response of reporter peptide by a combination of aptamer-peptide probe and LC-MS/MS. The selected aptamer-peptide probe consisted of aptamer HB5 and the substrate peptide GDKAVLGVDPFR that contained the reporter peptide AVLGVDPFR. After characterization of this newly synthesized probe (e.g., conjugation efficiency, stability, binding affinity, specificity, and digestion efficiency), probe binding and trypsin shaving conditions were optimized. The resulting limit of quantification for HER2 was 25 pmol/L. Then, the quasi-targeted proteomics assay was applied to determine the HER2 concentrations in the HER2-positive breast cancer cells BT474 and SK-BR-3, the HER2-negative breast cancer cells MDA-MB-231 and MCF-7, and 36 pairs of human breast primary tumors and adjacent normal tissue samples. The results were highly concordant with those obtained by immunohistochemistry with reflex testing by fluorescent in situ hybridization. Quasi-targeted proteomics can be a quantitative alternative for HER2 detection. © 2017 American Association for Clinical Chemistry.

Identification and characterization of highly versatile peptide-vectors that bind non-competitively to the low-density lipoprotein receptor for in vivo targeting and delivery of small molecules and protein cargos

PubMed Central

David, Marion; Lécorché, Pascaline; Masse, Maxime; Faucon, Aude; Abouzid, Karima; Gaudin, Nicolas; Varini, Karine; Gassiot, Fanny; Ferracci, Géraldine; Jacquot, Guillaume; Vlieghe, Patrick

2018-01-01

Insufficient membrane penetration of drugs, in particular biotherapeutics and/or low target specificity remain a major drawback in their efficacy. We propose here the rational characterization and optimization of peptides to be developed as vectors that target cells expressing specific receptors involved in endocytosis or transcytosis. Among receptors involved in receptor-mediated transport is the LDL receptor. Screening complex phage-displayed peptide libraries on the human LDLR (hLDLR) stably expressed in cell lines led to the characterization of a family of cyclic and linear peptides that specifically bind the hLDLR. The VH411 lead cyclic peptide allowed endocytosis of payloads such as the S-Tag peptide or antibodies into cells expressing the hLDLR. Size reduction and chemical optimization of this lead peptide-vector led to improved receptor affinity. The optimized peptide-vectors were successfully conjugated to cargos of different nature and size including small organic molecules, siRNAs, peptides or a protein moiety such as an Fc fragment. We show that in all cases, the peptide-vectors retain their binding affinity to the hLDLR and potential for endocytosis. Following i.v. administration in wild type or ldlr-/- mice, an Fc fragment chemically conjugated or fused in C-terminal to peptide-vectors showed significant biodistribution in LDLR-enriched organs. We have thus developed highly versatile peptide-vectors endowed with good affinity for the LDLR as a target receptor. These peptide-vectors have the potential to be further developed for efficient transport of therapeutic or imaging agents into cells -including pathological cells—or organs that express the LDLR. PMID:29485998

Effects of gastric inhibitory polypeptide, glucagon-like peptide-1 and glucagon-like peptide-1 receptor agonists on Bone Cell Metabolism.

PubMed

Hansen, Morten S S; Tencerova, Michaela; Frølich, Jacob; Kassem, Moustapha; Frost, Morten

2018-01-01

The relationship between gut and skeleton is increasingly recognized as part of the integrated physiology of the whole organism. The incretin hormones gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are secreted from the intestine in response to nutrient intake and exhibit several physiological functions including regulation of islet hormone secretion and glucose levels. A number of GLP-1 receptor agonists (GLP-1RAs) are currently used in treatment of type 2 diabetes and obesity. However, GIP and GLP-1 cognate receptors are widely expressed suggesting that incretin hormones mediate effects beyond control of glucose homeostasis, and reports on associations between incretin hormones and bone metabolism have emerged. The aim of this MiniReview was to provide an overview of current knowledge regarding the in vivo and in vitro effects of GIP and GLP-1 on bone metabolism. We identified a total of 30 pre-clinical and clinical investigations of the effects of GIP, GLP-1 and GLP-1RAs on bone turnover markers, bone mineral density (BMD), bone microarchitecture and fracture risk. Studies conducted in cell cultures and rodents demonstrated that GIP and GLP-1 play a role in regulating skeletal homeostasis, with pre-clinical data suggesting that GIP inhibits bone resorption whereas GLP-1 may promote bone formation and enhance bone material properties. These effects are not corroborated by clinical studies. While there is evidence of effects of GIP and GLP-1 on bone metabolism in pre-clinical investigations, clinical trials are needed to clarify whether similar effects are present and clinically relevant in humans. © 2017 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

SPR4-peptide Alters Bone Metabolism of Normal and HYP Mice

PubMed Central

Zelenchuk, Lesya V; Hedge, Anne-Marie; Rowe, Peter S N

2015-01-01

Context ASARM-peptides are substrates and ligands for PHEX, the gene responsible for X-linked hypophosphatemic rickets (HYP). PHEX binds to the DMP1-ASARM-motif to form a trimeric-complex with α5β3-integrin on the osteocyte surface and this suppresses FGF23 expression. ASARM-peptide disruption of this complex increases FGF23 expression. We used a 4.2 kDa peptide (SPR4) that binds to ASARM-peptide and ASARM-motif to study DMP1-PHEX interactions and to assess SPR4 for treating inherited hypophosphatemic rickets. Design Subcutaneously transplanted osmotic pumps were used to infuse SPR4-peptide or vehicle into wild-type mice (WT) and HYP-mice for 4 weeks. Results Asymmetrically distributed mineralization defects occurred with WT-SPR4 femurs. Specifically, SPR4 induced negative effects on trabecular bone and increased bone volume and mineralization in cortical-bone. Markedly increased sclerostin and reduced active β-catenin occurred with HYP mice. SPR4-infusion suppressed sclerostin and increased active β-catenin in WT and HYP mice and improved HYP-mice trabecular mineralization defects but not cortical mineralization defects. Conclusions SPR4-peptide has bimodal activity and acts by: (1) preventing DMP1 binding to PHEX and (2) sequestering an inhibitor of DMP1-PHEX binding, ASARM-peptide. In PHEX defective HYP-mice the second pathway predominates. Although SPR4-peptide improved trabecular calcification defects, decreased sclerostin and increased active β-catenin it did not correct HYP-mice cortical mineralization defects on a normal phosphate diet. Thus, for inherited hypophosphatemic rickets patients on a normal phosphate diet, SPR4-peptide is not a useful therapeutic. PMID:25460577

Argininosuccinate Synthetase Is a Functional Target for a Snake Venom Anti-hypertensive Peptide

PubMed Central

Guerreiro, Juliano R.; Lameu, Claudiana; Oliveira, Eduardo F.; Klitzke, Clécio F.; Melo, Robson L.; Linares, Edlaine; Augusto, Ohara; Fox, Jay W.; Lebrun, Ivo; Serrano, Solange M. T.; Camargo, Antonio C. M.

2009-01-01

Bj-BPP-10c is a bioactive proline-rich decapeptide, part of the C-type natriuretic peptide precursor, expressed in the brain and in the venom gland of Bothrops jararaca. We recently showed that Bj-BPP-10c displays a strong, sustained anti-hypertensive effect in spontaneous hypertensive rats (SHR), without causing any effect in normotensive rats, by a pharmacological effect independent of angiotensin-converting enzyme inhibition. Therefore, we hypothesized that another mechanism should be involved in the peptide activity. Here we used affinity chromatography to search for kidney cytosolic proteins with affinity for Bj-BPP-10c and demonstrate that argininosuccinate synthetase (AsS) is the major protein binding to the peptide. More importantly, this interaction activates the catalytic activity of AsS in a dose-de pend ent manner. AsS is recognized as an important player of the citrulline-NO cycle that represents a potential limiting step in NO synthesis. Accordingly, the functional interaction of Bj-BPP-10c and AsS was evidenced by the following effects promoted by the peptide: (i) increase of NO metabolite production in human umbilical vein endothelial cell culture and of arginine in human embryonic kidney cells and (ii) increase of arginine plasma concentration in SHR. Moreover, α-methyl-dl-aspartic acid, a specific AsS inhibitor, significantly reduced the anti-hypertensive activity of Bj-BPP-10c in SHR. Taken together, these results suggest that AsS plays a role in the anti-hypertensive action of Bj-BPP-10c. Therefore, we propose the activation of AsS as a new mechanism for the anti-hypertensive effect of Bj-BPP-10c in SHR and AsS as a novel target for the therapy of hypertension-related diseases. PMID:19491403

SUMOFLUX: A Generalized Method for Targeted 13C Metabolic Flux Ratio Analysis

PubMed Central

Kogadeeva, Maria

2016-01-01

Metabolic fluxes are a cornerstone of cellular physiology that emerge from a complex interplay of enzymes, carriers, and nutrients. The experimental assessment of in vivo intracellular fluxes using stable isotopic tracers is essential if we are to understand metabolic function and regulation. Flux estimation based on 13C or 2H labeling relies on complex simulation and iterative fitting; processes that necessitate a level of expertise that ordinarily preclude the non-expert user. To overcome this, we have developed SUMOFLUX, a methodology that is broadly applicable to the targeted analysis of 13C-metabolic fluxes. By combining surrogate modeling and machine learning, we trained a predictor to specialize in estimating flux ratios from measurable 13C-data. SUMOFLUX targets specific flux features individually, which makes it fast, user-friendly, applicable to experimental design and robust in terms of experimental noise and exchange flux magnitude. Collectively, we predict that SUMOFLUX's properties realistically pave the way to high-throughput flux analyses. PMID:27626798

Food odors trigger an endocrine response that affects food ingestion and metabolism.

PubMed

Lushchak, Oleh V; Carlsson, Mikael A; Nässel, Dick R

2015-08-01

Food odors stimulate appetite and innate food-seeking behavior in hungry animals. The smell of food also induces salivation and release of gastric acid and insulin. Conversely, sustained odor exposure may induce satiation. We demonstrate novel effects of food odors on food ingestion, metabolism and endocrine signaling in Drosophila melanogaster. Acute exposure to attractive vinegar odor triggers a rapid and transient increase in circulating glucose, and a rapid upregulation of genes encoding the glucagon-like hormone adipokinetic hormone (AKH), four insulin-like peptides (DILPs) and some target genes in peripheral tissues. Sustained exposure to food odors, however, decreases food intake. Hunger-induced strengthening of synaptic signaling from olfactory sensory neurons (OSNs) to brain neurons increases food-seeking behavior, and conversely fed flies display reduced food odor sensitivity and feeding. We show that increasing the strength of OSN signaling chronically by genetic manipulation of local peptide neuromodulation reduces feeding, elevates carbohydrates and diminishes lipids. Furthermore, constitutively strengthened odor sensitivity altered gene transcripts for AKH, DILPs and some of their targets. Thus, we show that food odor can induce a transient anticipatory endocrine response, and that boosted sensitivity to this odor affects food intake, as well as metabolism and hormonal signaling.

Phage-display screening identifies LMP1-binding peptides targeting the C-terminus region of the EBV oncoprotein.

PubMed

Ammous-Boukhris, Nihel; Mosbah, Amor; Sahli, Emna; Ayadi, Wajdi; Hadhri-Guiga, Boutheina; Chérif, Ameur; Gargouri, Ali; Mokdad-Gargouri, Raja

2016-11-01

Latent membrane protein 1 (LMP1), a major oncoprotein of Epstein Barr Virus (EBV) is responsible for transforming B lymphocytes in vitro. LMP1 is overexpressed in several EBV-associated malignancies, and different approaches have been developed to reduce its level and accordingly its oncogenic function in tumor tissues. This study aimed to use phage display peptide library to obtain peptides which could specifically bind to the cytoplasmic region of LMP1 to prevent its interaction with signaling proteins. The LMP1 C-terminus region was produced in bacterial E. coli and used as target for the phage library panning. After 3 rounds, 20 phage clones were randomly selected and 8 showed high binding affinity to the recombinant C-terminus LMP1 protein. The most interesting candidates are the FO5 "QPTKDSSPPLRV" and NO4 "STTSPPAVPHNN" peptides since both bind the C-terminus LMP1 as showed by molecular docking. Furthermore, sequence alignment revealed that the FO5 peptide shared sequence similarity with the Death Receptor 4 which belongs to the tumor necrosis factor-related apoptosis-inducing receptor which plays key role in anti-tumor immunity. Copyright © 2016 Elsevier Inc. All rights reserved.

The antimicrobial peptide nisin Z induces selective toxicity and apoptotic cell death in cultured melanoma cells.

PubMed

Lewies, Angélique; Wentzel, Johannes Frederik; Miller, Hayley Christy; Du Plessis, Lissinda Hester

2018-01-01

Reprogramming of cellular metabolism is now considered one of the hallmarks of cancer. Most malignant cells present with altered energy metabolism which is associated with elevated reactive oxygen species (ROS) generation. This is also evident for melanoma, the leading cause of skin cancer related deaths. Altered mechanisms affecting mitochondrial bioenergetics pose attractive targets for novel anticancer therapies. Antimicrobial peptides have been shown to exhibit selective anticancer activities. In this study, the anti-melanoma potential of the antimicrobial peptide, nisin Z, was evaluated in vitro. Nisin Z was shown to induce selective toxicity in melanoma cells compared to non-malignant keratinocytes. Furthermore, nisin Z was shown to negatively affect the energy metabolism (glycolysis and mitochondrial respiration) of melanoma cells, increase reactive oxygen species generation and cause apoptosis. Results also indicate that nisin Z can decrease the invasion and proliferation of melanoma cells demonstrating its potential use against metastasis associated with melanoma. As nisin Z seems to place a considerable extra burden on the energy metabolism of melanoma cells, combination therapies with known anti-melanoma agents may be effective treatment options. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Characterization of Three Venom Peptides from the Spitting Spider Scytodes thoracica

PubMed Central

Ariki, Nathanial K.; Muñoz, Lisa E.; Armitage, Elizabeth L.; Goodstein, Francesca R.; George, Kathryn G.; Smith, Vanessa L.; Vetter, Irina; Herzig, Volker; King, Glenn F.; Loening, Nikolaus M.

2016-01-01

We present the solution-state NMR structures and preliminary functional characterizations of three venom peptides identified from the spitting spider Scytodes thoracica. Despite little sequence identity to other venom peptides, structural characterization reveals that these peptides contain an inhibitor cystine knot motif common to many venom peptides. These are the first structures for any peptide or protein from spiders of the Scytodidae family. Many venom peptides target neuronal ion channels or receptors. However, we have not been able to determine the target of these Scytodes peptides so we can only state with certainty the channels and receptors that they do not target. PMID:27227898

Targeting of follicle stimulating hormone peptide-conjugated dendrimers to ovarian cancer cells

NASA Astrophysics Data System (ADS)

Modi, Dimple A.; Sunoqrot, Suhair; Bugno, Jason; Lantvit, Daniel D.; Hong, Seungpyo; Burdette, Joanna E.

2014-02-01

Ovarian cancer is the most lethal gynecological malignancy. Current treatment modalities include a combination of surgery and chemotherapy, which often lead to loss of fertility in premenopausal women and a myriad of systemic side effects. To address these issues, we have designed poly(amidoamine) (PAMAM) dendrimers to selectively target the follicle stimulating hormone receptor (FSHR), which is overexpressed by tumorigenic ovarian cancer cells but not by immature primordial follicles and other non-tumorigenic cells. Fluorescein-labeled generation 5 (G5) PAMAM dendrimers were conjugated with the binding peptide domain of FSH (FSH33) that has a high affinity to FSHR. The targeted dendrimers exhibited high receptor selectivity to FSHR-expressing OVCAR-3 cells, resulting in significant uptake and downregulation of an anti-apoptotic protein survivin, while showing minimal interactions with SKOV-3 cells that do not express FSHR. The selectivity of the FSH33-targeted dendrimers was further validated in 3D organ cultures of normal mouse ovaries. Immunostaining of the conjugates revealed their selective binding and uptake by ovarian surface epithelium (OSE) cells that express FSHR, while sparing the immature primordial follicles. In addition, an in vivo study monitoring tissue accumulation following a single intraperitoneal (i.p.) injection of the conjugates showed significantly higher accumulation of FSH33-targeted dendrimers in the ovary and oviduct compared to the non-targeted conjugates. These proof-of-concept findings highlight the potential of these FSH33-targeted dendrimers to serve as a delivery platform for anti-ovarian cancer drugs, while reducing their systemic side effects by preventing nonspecific uptake by the primordial follicles.Ovarian cancer is the most lethal gynecological malignancy. Current treatment modalities include a combination of surgery and chemotherapy, which often lead to loss of fertility in premenopausal women and a myriad of systemic side

Detection and in vitro metabolism of the confiscated peptides BPC 157 and MGF R23H.

PubMed

Cox, Holly D; Miller, Geoff D; Eichner, Daniel

2017-10-01

A new peptide, body protecting compound (BPC), BPC 157, and a variant of mechano-growth factor (MGF), MGF R23H, were identified in confiscated vials. BPC 157 has the amino acid sequence, GEPPPGKPADDAGLV, and is currently under investigation for the promotion of healing and recovery in a variety of tissues. In vitro metabolism experiments in plasma demonstrate that MGF R23H has good stability and should be detectable in urine, while BPC 157 forms a stable metabolite that should be detectable in urine. A weak cation exchange solid phase extraction method was validated for detection of BPC 157 in urine. The method has a limit of detection of 0.1 ng/mL, precision of less than 20%, and good linearity, r 2 0.998. BPC 157 was stable in urine for at least 4 days. The specificity of the method is improved by measurement of a potential BPC metabolite along with the parent peptide. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Improved heterologous production of the nonribosomal peptide-polyketide siderophore yersiniabactin through metabolic engineering and induction optimization.

PubMed

Ahmadi, Mahmoud Kamal; Pfeifer, Blaine A

2016-11-01

Biosynthesis of complex natural products like polyketides and nonribosomal peptides using Escherichia coli as a heterologous host provides an opportunity to access these molecules. The value in doing so stems from the fact that many compounds hold some therapeutic or other beneficial property and their original production hosts are intractable for a variety of reasons. In this work, metabolic engineering and induction variable optimization were used to increase production of the polyketide-nonribosomal peptide compound yersiniabactin, a siderophore that has been utilized to selectively remove metals from various solid and aqueous samples. Specifically, several precursor substrate support pathways were altered through gene expression and exogenous supplementation in order to boost production of the final compound. The gene expression induction process was also analyzed to identify the temperatures and inducer concentrations resulting in highest final production levels. When combined, yersiniabactin production was extended to ∼175 mg L -1 . © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1412-1417, 2016. © 2016 American Institute of Chemical Engineers.

Cytotoxic Tumor-Targeting Peptides From In Vivo Phage Display.

PubMed

Northup, Jessica R Newton; Deutscher, Susan L

2016-01-01

We previously utilized an in vivo peptide phage display selection technique, which included the use of detergent elution of phage from excised tumor, to obtain tumor-targeting phage with the ability to extravasate the vasculature and bind directly to prostate tumor tissue. It is hypothesized that this same in vivo phage selection technique can be used to functionally select for molecules that not only bind to cancer cells but also kill them. Here we analyzed two different in vivo phage display selected phage clones, G1 and H5, retrieved from PC-3 human prostate carcinoma xenografted tumors. First, cell de-attachment as an endpoint criterion for apoptosis and cell cycle was examined. After 2.5 hours incubation with G1 phage, PC-3 cell attachment was reduced by 23.8% and the percent of cell population in M phase reduced by 32.1%. In comparison, PC-3 cells incubated with H5 phage had a reduction of 25.0% cell attachment and 33.6% of cell population in M phase. These changes in combination with elevated caspase activation within cells in M phase, and no significant changes to G1/G0 or S phase cell populations suggest that the cytotoxic phages are targeting actively dividing PC-3 cells. Microscopic studies were also performed to further analyze the nature of cytotoxicity of these two phage clones. It was found that G1 phage induced and co- localized with tubulin based projections within apoptotic cells, while H5 phage did not. These phage may form the foundation for a new class of targeted prostate cancer therapeutic agents.

Quantitation of Specific Barley, Rye, and Oat Marker Peptides by Targeted Liquid Chromatography-Mass Spectrometry To Determine Gluten Concentrations.

PubMed

Schalk, Kathrin; Koehler, Peter; Scherf, Katharina Anne

2018-04-04

Celiac disease is triggered by the ingestion of gluten from wheat, barley, rye, and possibly oats. Gluten is quantitated by DNA-based methods or enzyme-linked immunosorbent assays (ELISAs). ELISAs mostly detect the prolamin fraction and potentially over- or underestimate gluten contents. Therefore, a new independent method is required to comprehensively detect gluten. A targeted liquid chromatography-tandem mass spectrometry method was developed to quantitate seven barley, seven rye, and three oat marker peptides derived from each gluten protein fraction (prolamin and glutelin) and type (barley, B-, C-, D-, and γ-hordeins; rye, γ-75k-, γ-40k-, ω-, and HMW-secalins). The quantitation of each marker peptide in the chymotryptic digest of a defined amount of the respective reference gluten protein type resulted in peptide-specific yields, which enabled the conversion of peptide into protein concentrations. This method was applied to quantitate gluten in samples from the brewing process, in raw materials for sourdough fermentation, and in dried sourdoughs.

The PeptideAtlas Project.

PubMed

Deutsch, Eric W

2010-01-01

PeptideAtlas is a multi-species compendium of peptides observed with tandem mass spectrometry methods. Raw mass spectrometer output files are collected from the community and reprocessed through a uniform analysis and validation pipeline that continues to advance. The results are loaded into a database and the information derived from the raw data is returned to the community via several web-based data exploration tools. The PeptideAtlas resource is useful for experiment planning, improving genome annotation, and other data mining projects. PeptideAtlas has become especially useful for planning targeted proteomics experiments.

Synthesis and characterization of Her2-NLP peptide conjugates targeting circulating breast cancer cells: cellular uptake and localization by fluorescent microscopic imaging.

PubMed

Cai, Huawei; Singh, Ajay N; Sun, Xiankai; Peng, Fangyu

2015-01-01

To synthesize a fluorescent Her2-NLP peptide conjugate consisting of Her2/neu targeting peptide and nuclear localization sequence peptide (NLP) and assess its cellular uptake and intracellular localization for radionuclide cancer therapy targeting Her2/neu-positive circulating breast cancer cells (CBCC). Fluorescent Cy5.5 Her2-NLP peptide conjugate was synthesized by coupling a bivalent peptide sequence, which consisted of a Her2-binding peptide (NH2-GSGKCCYSL) and an NLP peptide (CGYGPKKKRKVGG) linked by a polyethylene glycol (PEG) chain with 6 repeating units, with an activated Cy5.5 ester. The conjugate was separated and purified by HPLC and then characterized by Maldi-MS. The intracellular localization of fluorescent Cy5.5 Her2-NLP peptide conjugate was assessed by fluorescent microscopic imaging using a confocal microscope after incubation of Cy5.5-Her2-NLP with Her2/neu positive breast cancer cells and Her2/neu negative control breast cancer cells, respectively. Fluorescent signals were detected in cytoplasm of Her2/neu positive breast cancer cells (SKBR-3 and BT474 cell lines), but not or little in cytoplasm of Her2/neu negative breast cancer cells (MDA-MB-231), after incubation of the breast cancer cells with Cy5.5-Her2-NLP conjugates in vitro. No fluorescent signals were detected within the nuclei of Her2/neu positive SKBR-3 and BT474 breast cancer cells, neither Her2/neu negative MDA-MB-231 cells, incubated with the Cy5.5-Her2-NLP peptide conjugates, suggesting poor nuclear localization of the Cy5.5-Her2-NLP conjugates localized within the cytoplasm after their cellular uptake and internalization by the Her2/neu positive breast cancer cells. Her2-binding peptide (KCCYSL) is a promising agent for radionuclide therapy of Her2/neu positive breast cancer using a β(-) or α emitting radionuclide, but poor nuclear localization of the Her2-NLP peptide conjugates may limit its use for eradication of Her2/neu-positive CBCC using I-125 or other Auger electron

Specific enrichment of a targeted nitrotyrosine-containing peptide from complex matrices and relative quantification for liquid chromatography-mass spectrometry analysis.

PubMed

Yang, Yun

2017-02-17

Protein tyrosine nitration is considered an important non-enzymatic post-translational modification. In the tyrosine nitration process, 3-nitrotyrosine is formed and recognized as a biomarker of nitrosative/nitrative stress implicated in inflammatory responses and age-related disorders. In view of the complexity of biological samples and the ultra-low abundance of protein-incorporated nitrotyrosine, selective enrichment of nitrotyrosine-containing peptides prior to chromatographic separation is crucial. Herein, I report a simple yet highly specific and efficient enrichment method for nitrotyrosine-containing peptides. After blocking all primary amines in the sample by acetylation with acetic anhydride, I then further converted all nitrotyrosine residues into aminotyrosine residues by reduction with dithiothreitol and hemin. Therefore, I eliminated the side-product with 80Da adduct, since inevitable considerable amount of which was generated in the widely used reduction mediated by sodium dithionite. Both acetylation and reduction yields were close to 100%, and my one-pot sample derivatization applied no solid phase extraction steps or sample transference to avoid sample loss. To capture and release aminotyrosine-containing peptides, I synthesized an N-hydroxysuccinimide-ester-functionalized stationary phase which had very high affinity towards amino groups and possessed a base-cleavable ester linker to retrieve targeted peptides by hydrolysis. I validated this strategy by highly efficient enrichment of the targeted peptide from complex matrices of trypsin-digested bovine serum albumin (BSA) and human plasma spiked with derivatized nitrotyrosine-containing angiotensin II. My enrichment method successfully removed most untargeted peptides in those samples. By relative quantification with home-made identical and stable-isotope labelled internal standards, I investigated the recoveries of a nitrotyrosine-containing peptide from complex biological matrices during

Efficient Covalent Bond Formation in Gas-Phase Peptide-Peptide Ion Complexes with the Photoleucine Stapler

NASA Astrophysics Data System (ADS)

Shaffer, Christopher J.; Andrikopoulos, Prokopis C.; Řezáč, Jan; Rulíšek, Lubomír; Tureček, František

2016-04-01

Noncovalent complexes of hydrophobic peptides GLLLG and GLLLK with photoleucine (L*) tagged peptides G(L* n L m )K (n = 1,3, m = 2,0) were generated as singly charged ions in the gas phase and probed by photodissociation at 355 nm. Carbene intermediates produced by photodissociative loss of N2 from the L* diazirine rings underwent insertion into X-H bonds of the target peptide moiety, forming covalent adducts with yields reaching 30%. Gas-phase sequencing of the covalent adducts revealed preferred bond formation at the C-terminal residue of the target peptide. Site-selective carbene insertion was achieved by placing the L* residue in different positions along the photopeptide chain, and the residues in the target peptide undergoing carbene insertion were identified by gas-phase ion sequencing that was aided by specific 13C labeling. Density functional theory calculations indicated that noncovalent binding to GL*L*L*K resulted in substantial changes of the (GLLLK + H)+ ground state conformation. The peptide moieties in [GL*L*LK + GLLLK + H]+ ion complexes were held together by hydrogen bonds, whereas dispersion interactions of the nonpolar groups were only secondary in ground-state 0 K structures. Born-Oppenheimer molecular dynamics for 100 ps trajectories of several different conformers at the 310 K laboratory temperature showed that noncovalent complexes developed multiple, residue-specific contacts between the diazirine carbons and GLLLK residues. The calculations pointed to the substantial fluidity of the nonpolar side chains in the complexes. Diazirine photochemistry in combination with Born-Oppenheimer molecular dynamics is a promising tool for investigations of peptide-peptide ion interactions in the gas phase.

Overexpression of hypoxia-inducible factor and metabolic pathways: possible targets of cancer.

PubMed

Singh, Davinder; Arora, Rohit; Kaur, Pardeep; Singh, Balbir; Mannan, Rahul; Arora, Saroj

2017-01-01

Cancer, the main cause of human deaths in the modern world is a group of diseases. Anticancer drug discovery is a challenge for scientists because of involvement of multiple survival pathways of cancer cells. An extensive study on the regulation of each step of these pathways may help find a potential cancer target. Up-regulated HIF-1 expression and altered metabolic pathways are two classical characteristics of cancer. Oxygen-dependent (through pVHL, PHDs, calcium-mediated) and independent (through growth factor signaling pathway, mdm2 pathway, HSP90) regulation of HIF-1α leads to angiogenesis, metastasis, and cell survival. The two subunits of HIF-1 regulates in the same fashion through different mechanisms. HIF-1α translation upregulates via mammalian target of rapamycin and mitogen-activated protein kinase signaling pathways, whereas HIF-1β through calmodulin kinase. Further, the stabilized interactions of these two subunits are important for proper functioning. Also, metabolic pathways crucial for the formation of building blocks (pentose phosphate pathway) and energy generation (glycolysis, TCA cycle and catabolism of glutamine) are altered in cancer cells to protect them from oxidative stress and to meet the reduced oxygen and nutrient supply. Up-regulated anaerobic metabolism occurs through enhanced expression of hexokinase, phosphofructokinase, triosephosphate isomerase, glucose 6-phosphate dehydrogenase and down-regulation of aerobic metabolism via pyruvate dehydrogenase kinase and lactate dehydrogenase which compensate energy requirements along with high glucose intake. Controlled expression of these two pathways through their common intermediate may serve as potent cancer target in future.

Apelin targets gut contraction to control glucose metabolism via the brain

PubMed Central

Fournel, Audren; Drougard, Anne; Duparc, Thibaut; Marlin, Alysson; Brierley, Stuart M; Castro, Joel; Le-Gonidec, Sophie; Masri, Bernard; Colom, André; Lucas, Alexandre; Rousset, Perrine; Cenac, Nicolas; Vergnolle, Nathalie; Valet, Philippe; Cani, Patrice D; Knauf, Claude

2017-01-01

Objective The gut–brain axis is considered as a major regulatory checkpoint in the control of glucose homeostasis. The detection of nutrients and/or hormones in the duodenum informs the hypothalamus of the host's nutritional state. This process may occur via hypothalamic neurons modulating central release of nitric oxide (NO), which in turn controls glucose entry into tissues. The enteric nervous system (ENS) modulates intestinal contractions in response to various stimuli, but the importance of this interaction in the control of glucose homeostasis via the brain is unknown. We studied whether apelin, a bioactive peptide present in the gut, regulates ENS-evoked contractions, thereby identifying a new physiological partner in the control of glucose utilisation via the hypothalamus. Design We measured the effect of apelin on electrical and mechanical duodenal responses via telemetry probes and isotonic sensors in normal and obese/diabetic mice. Changes in hypothalamic NO release, in response to duodenal contraction modulated by apelin, were evaluated in real time with specific amperometric probes. Glucose utilisation in tissues was measured with orally administrated radiolabeled glucose. Results In normal and obese/diabetic mice, glucose utilisation is improved by the decrease of ENS/contraction activities in response to apelin, which generates an increase in hypothalamic NO release. As a consequence, glucose entry is significantly increased in the muscle. Conclusions Here, we identify a novel mode of communication between the intestine and the hypothalamus that controls glucose utilisation. Moreover, our data identified oral apelin administration as a novel potential target to treat metabolic disorders. PMID:26565000

Metabolic analysis of radioresistant medulloblastoma stem-like clones and potential therapeutic targets

PubMed Central

Sun, Lue; Moritake, Takashi; Ito, Kazuya; Matsumoto, Yoshitaka; Yasui, Hironobu; Nakagawa, Hidehiko; Hirayama, Aki; Inanami, Osamu; Tsuboi, Koji

2017-01-01

Medulloblastoma is a fatal brain tumor in children, primarily due to the presence of treatment-resistant medulloblastoma stem cells. The energy metabolic pathway is a potential target of cancer therapy because it is often different between cancer cells and normal cells. However, the metabolic properties of medulloblastoma stem cells, and whether specific metabolic pathways are essential for sustaining their stem cell-like phenotype and radioresistance, remain unclear. We have established radioresistant medulloblastoma stem-like clones (rMSLCs) by irradiation of the human medulloblastoma cell line ONS-76. Here, we assessed reactive oxygen species (ROS) production, mitochondria function, oxygen consumption rate (OCR), energy state, and metabolites of glycolysis and tricarboxylic acid cycle in rMSLCs and parental cells. rMSLCs showed higher lactate production and lower oxygen consumption rate than parental cells. Additionally, rMSLCs had low mitochondria mass, low endogenous ROS production, and existed in a low-energy state. Treatment with the metabolic modifier dichloroacetate (DCA) resulted in mitochondria dysfunction, glycolysis inhibition, elongated mitochondria morphology, and increased ROS production. DCA also increased radiosensitivity by suppression of the DNA repair capacity through nuclear oxidization and accelerated the generation of acetyl CoA to compensate for the lack of ATP. Moreover, treatment with DCA decreased cancer stem cell-like characters (e.g., CD133 positivity and sphere-forming ability) in rMSLCs. Together, our findings provide insights into the specific metabolism of rMSLCs and illuminate potential metabolic targets that might be exploited for therapeutic benefit in medulloblastoma. PMID:28426747

A novel HLA-A*0201 restricted peptide derived from cathepsin G is an effective immunotherapeutic target in acute myeloid leukemia.

PubMed

Zhang, Mao; Sukhumalchandra, Pariya; Enyenihi, Atim A; St John, Lisa S; Hunsucker, Sally A; Mittendorf, Elizabeth A; Sergeeva, Anna; Ruisaard, Kathryn; Al-Atrache, Zein; Ropp, Patricia A; Jakher, Haroon; Rodriguez-Cruz, Tania; Lizee, Gregory; Clise-Dwyer, Karen; Lu, Sijie; Molldrem, Jeffrey J; Glish, Gary L; Armistead, Paul M; Alatrash, Gheath

2013-01-01

Immunotherapy targeting aberrantly expressed leukemia-associated antigens has shown promise in the management of acute myeloid leukemia (AML). However, because of the heterogeneity and clonal evolution that is a feature of myeloid leukemia, targeting single peptide epitopes has had limited success, highlighting the need for novel antigen discovery. In this study, we characterize the role of the myeloid azurophil granule protease cathepsin G (CG) as a novel target for AML immunotherapy. We used Immune Epitope Database and in vitro binding assays to identify immunogenic epitopes derived from CG. Flow cytometry, immunoblotting, and confocal microscopy were used to characterize the expression and processing of CG in AML patient samples, leukemia stem cells, and normal neutrophils. Cytotoxicity assays determined the susceptibility of AML to CG-specific cytotoxic T lymphocytes (CTL). Dextramer staining and cytokine flow cytometry were conducted to characterize the immune response to CG in patients. CG was highly expressed and ubiquitinated in AML blasts, and was localized outside granules in compartments that facilitate antigen presentation. We identified five HLA-A*0201 binding nonameric peptides (CG1-CG5) derived from CG, and showed immunogenicity of the highest HLA-A*0201 binding peptide, CG1. We showed killing of primary AML by CG1-CTL, but not normal bone marrow. Blocking HLA-A*0201 abrogated CG1-CTL-mediated cytotoxicity, further confirming HLA-A*0201-dependent killing. Finally, we showed functional CG1-CTLs in peripheral blood from AML patients following allogeneic stem cell transplantation. CG is aberrantly expressed and processed in AML and is a novel immunotherapeutic target that warrants further development.

Developing a fluorescence-coupled capillary electrophoresis based method to probe interactions between QDs and colorectal cancer targeting peptides.

PubMed

Liu, Feifei; Wang, Jianhao; Yang, Li; Liu, Li; Ding, Shumin; Fu, Minli; Deng, Linhong; Gao, Li-Qian

2016-08-01

As is well known, quantum dots (QDs) have become valuable probes for cancer imaging. In particular, QD-labeled targeting peptides are capable of identifying cancer or tumors cells. A new colorectal cancer targeting peptide, cyclo(1, 9)-CTPSPFSHC, has strong targeting ability and also shows great potential in the identification and treatment of colon cancer. Herein, we synthesized a dual functional polypeptide, cyclo(1, 9)-CTPSPFSHCD2 G2 DP9 G3 H6 (H6 -TCP), to investigate its interaction with QDs inside the capillary. Fluorescence-coupled CE was adopted and applied to characterize the self-assembly of H6 -TCP onto QDs. It was indicated that the formation of the assembly was affected by H6 -TCP/QD molar ratio and sampling time. This novel in-capillary assay greatly reduced the sample consumption and the detection time, which was beneficial for the environment. It is expected that this kind of detection method could find more applications to provide more useful information for cancer diagnosis and detection of harm and hazardous substances/organisms in the environment in the future. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Peptide receptor targeting in cancer: the somatostatin paradigm.

PubMed

Barbieri, Federica; Bajetto, Adriana; Pattarozzi, Alessandra; Gatti, Monica; Würth, Roberto; Thellung, Stefano; Corsaro, Alessandro; Villa, Valentina; Nizzari, Mario; Florio, Tullio

2013-01-01

Peptide receptors involved in pathophysiological processes represent promising therapeutic targets. Neuropeptide somatostatin (SST) is produced by specialized cells in a large number of human organs and tissues. SST primarily acts as inhibitor of endocrine and exocrine secretion via the activation of five G-protein-coupled receptors, named sst1-5, while in central nervous system, SST acts as a neurotransmitter/neuromodulator, regulating locomotory and cognitive functions. Critical points of SST/SST receptor biology, such as signaling pathways of individual receptor subtypes, homo- and heterodimerization, trafficking, and cross-talk with growth factor receptors, have been extensively studied, although functions associated with several pathological conditions, including cancer, are still not completely unraveled. Importantly, SST exerts antiproliferative and antiangiogenic effects on cancer cells in vitro, and on experimental tumors in vivo. Moreover, SST agonists are clinically effective as antitumor agents for pituitary adenomas and gastro-pancreatic neuroendocrine tumors. However, SST receptors being expressed by tumor cells of various tumor histotypes, their pharmacological use is potentially extendible to other cancer types, although to date no significant results have been obtained. In this paper the most recent findings on the expression and functional roles of SST and SST receptors in tumor cells are discussed.

Ultra-high-pressure processing improves proteolysis and release of bioactive peptides with activation activities on alcohol metabolic enzymes in vitro from mushroom foot protein.

PubMed

Zhao, Rui-Jie; Huo, Chun-Yan; Qian, Yang; Ren, Di-Feng; Lu, Jun

2017-09-15

This study was to find an effective process to extract bioactive peptides from mushroom foot and determine their effects on activation of alcohol metabolic enzymes in vitro. The optimum extraction assisted by ultra-high-pressure processing of mushroom foot peptides was obtained with a pressure of 400MPa and a processing time of 10min. After ultrafiltration, peptides with molecular weight of 0-3kDa had the highest activity to activate alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) by 70.79% and 71.35%, respectively. Following dextran gel chromatography, two peaks (p-I and p-II) appeared and the activation activities on ADH and ALDH of p-I were 72.00% and 73.43%, both higher than p-II. Nine peptides were found in p-I as determined by LC-MS/MS, and two of them (IPLH and IPIVLL) were synthesized. IPLH activated ADH and ALDH by 42.7% and 29.2% respectively, which were higher than IPIVLL. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anti-tumorigenic effect of nano formulated peptide pACC1 by diminishing de novo lipogenisis in DMBA induced mammary carcinoma rat model.

PubMed

Kaliaperumal, Jagatheesh; Padarthi, Pavankumar; Elangovan, Namasivayam; Hari, Natarajan

2014-07-01

At present, the majority of established treatments for breast cancer are based on clinical manifestations, some fundamental of molecular and cellular biology of cancer. In recent times, the therapy is moving towards personalized medicines. Nevertheless, both the methodologies have own demerits. In the present study, we proposed a novel idea of targeted therapy with twin pharmacological potential by a peptide pACC1. The peptide was formulated with chitosan and evaluated with DMBA induced mammary carcinoma. Results suggest that the peptide holds great control on tumor cell multiplication, fatty acid synthesis and lactate levels. In addition, peptide also brings normal metabolic signs in glycolytic and glycogenic pathways. Histological studies confirm the dual pharmacological actions. Further, it is also proven that the peptide controls membrane receptor levels of HER2 and EGFR. In conclusion, that the peptide pACC1 could be employed as greater therapeutic adjuvant with currently established drugs without considering the stage of the cancer. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Advancement and applications of peptide phage display technology in biomedical science.

PubMed

Wu, Chien-Hsun; Liu, I-Ju; Lu, Ruei-Min; Wu, Han-Chung

2016-01-19

Combinatorial phage library is a powerful research tool for high-throughput screening of protein interactions. Of all available molecular display techniques, phage display has proven to be the most popular approach. Screening phage-displayed random peptide libraries is an effective means of identifying peptides that can bind target molecules and regulate their function. Phage-displayed peptide libraries can be used for (i) B-cell and T-cell epitope mapping, (ii) selection of bioactive peptides bound to receptors or proteins, disease-specific antigen mimics, peptides bound to non-protein targets, cell-specific peptides, or organ-specific peptides, and (iii) development of peptide-mediated drug delivery systems and other applications. Targeting peptides identified using phage display technology may be useful for basic research and translational medicine. In this review article, we summarize the latest technological advancements in the application of phage-displayed peptide libraries to applied biomedical sciences.

Targeting lipid metabolism of cancer cells: A promising therapeutic strategy for cancer.

PubMed

Liu, Qiuping; Luo, Qing; Halim, Alexander; Song, Guanbin

2017-08-10

One of the most important metabolic hallmarks of cancer cells is deregulation of lipid metabolism. In addition, enhancing de novo fatty acid (FA) synthesis, increasing lipid uptake and lipolysis have also been considered as means of FA acquisition in cancer cells. FAs are involved in various aspects of tumourigenesis and tumour progression. Therefore, targeting lipid metabolism is a promising therapeutic strategy for human cancer. Recent studies have shown that reprogramming lipid metabolism plays important roles in providing energy, macromolecules for membrane synthesis, and lipid signals during cancer progression. Moreover, accumulation of lipid droplets in cancer cells acts as a pivotal adaptive response to harmful conditions. Here, we provide a brief review of the crucial roles of FA metabolism in cancer development, and place emphasis on FA origin, utilization and storage in cancer cells. Understanding the regulation of lipid metabolism in cancer cells has important implications for exploring a new therapeutic strategy for management and treatment of cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

Targeting diseased tissues by pHLIP insertion at low cell surface pH.

PubMed

Andreev, Oleg A; Engelman, Donald M; Reshetnyak, Yana K

2014-01-01

The discovery of the pH Low Insertion Peptides (pHLIPs®) provides an opportunity to develop imaging and drug delivery agents targeting extracellular acidity. Extracellular acidity is associated with many pathological states, such as those in cancer, ischemic stroke, neurotrauma, infection, lacerations, and others. The metabolism of cells in injured or diseased tissues often results in the acidification of the extracellular environment, so acidosis might be useful as a general marker for the imaging and treatment of diseased states if an effective targeting method can be developed. The molecular mechanism of a pHLIP peptide is based on pH-dependent membrane-associated folding. pHLIPs, being moderately hydrophobic peptides, have high affinities for cellular membranes at normal pH, but fold and insert across membranes at low pH, allowing them to sense pH at the surfaces of cells in diseased tissues, where it is the lowest. Here we discuss the main principles of pHLIP interactions with membrane lipid bilayers at neutral and low pHs, the possibility of tuning the folding and insertion pH by peptide sequence variation, and potential applications of pHLIPs for imaging, therapy and image-guided interventions.

Solid-phase-assisted synthesis of targeting peptide-PEG-oligo(ethane amino)amides for receptor-mediated gene delivery.

PubMed

Martin, Irene; Dohmen, Christian; Mas-Moruno, Carlos; Troiber, Christina; Kos, Petra; Schaffert, David; Lächelt, Ulrich; Teixidó, Meritxell; Günther, Michael; Kessler, Horst; Giralt, Ernest; Wagner, Ernst

2012-04-28

In the forthcoming era of cancer gene therapy, efforts will be devoted to the development of new efficient and non-toxic gene delivery vectors. In this regard, the use of Fmoc/Boc-protected oligo(ethane amino)acids as building blocks for solid-phase-supported assembly represents a novel promising approach towards fully controlled syntheses of effective gene vectors. Here we report on the synthesis of defined polymers containing the following: (i) a plasmid DNA (pDNA) binding domain of eight succinoyl-tetraethylenpentamine (Stp) units and two terminal cysteine residues; (ii) a central polyethylene glycol (PEG) chain (with twenty-four oxyethylene units) for shielding; and (iii) specific peptides for targeting towards cancer cells. Peptides B6 and c(RGDfK), which bind transferrin receptor and α(v)β(3) integrin, respectively, were chosen because of the high expression of these receptors in many tumoral cells. This study shows the feasibility of designing these kinds of fully controlled vectors and their success for targeted pDNA-based gene transfer. This journal is © The Royal Society of Chemistry 2012

Enhancement of cytotoxicity of antimicrobial peptide magainin II in tumor cells by bombesin-targeted delivery

PubMed Central

Liu, Shan; Yang, Hao; Wan, Lin; Cai, Hua-wei; Li, Sheng-fu; Li, You-ping; Cheng, Jing-qiu; Lu, Xiao-feng

2011-01-01

Aim: To investigate whether the conjugation of magainin II (MG2), an antimicrobial peptides (AMPs), to the tumor-homing peptide bombesin could enhance its cytotoxicity in tumor cells. Methods: A magainin II-bombesin conjugate (MG2B) was constructed by attaching magainin II (MG2) to bombesin at its N-terminus. The peptides were synthesized using Fmoc-chemistry. The in vitro cytotoxicity of the peptide in cancer cells was quantitatively determined using the CCK-8 cell counting kit. Moreover, the in vivo antitumor effect of the peptide was determined in tumor xenograft models. Results: The IC50 of MG2B for cancer cells (10–15 μmol/L) was at least 10 times lower than the IC50 of unconjugated MG2 (125 μmol/L). Moreover, the binding affinity of MG2B for cancer cells was higher than that of unconjugated MG2. In contrast, conjugation to a bombesin analog lacking the receptor-binding domain failed to increase the cytotoxicity of MG2, suggesting that bombesin conjugation enhances the cytotoxicity of MG2 in cancer cells through improved binding. Indeed, MG2B selectively induced cell death in cancer cells in vitro with the IC50 ranging from 10 to 15 μmol/L, which was about 6–10 times lower than the IC50 for normal cells. MG2B (20 mg/kg per day, intratumorally injected for 5 d) also exhibited antitumor effects in mice bearing MCF-7 tumor grafts. The mean weights of tumor grafts in MG2B- and PBS-treated mice were 0.21±0.05 g and 0.59±0.12 g, respectively. Conclusion: The results suggest that conjugation of AMPs to bombesin might be an alternative approach for targeted cancer therapy. PMID:21131998

Enhancement of cytotoxicity of antimicrobial peptide magainin II in tumor cells by bombesin-targeted delivery.

PubMed

Liu, Shan; Yang, Hao; Wan, Lin; Cai, Hua-wei; Li, Sheng-fu; Li, You-ping; Cheng, Jing-qiu; Lu, Xiao-feng

2011-01-01

To investigate whether the conjugation of magainin II (MG2), an antimicrobial peptides (AMPs), to the tumor-homing peptide bombesin could enhance its cytotoxicity in tumor cells. A magainin II-bombesin conjugate (MG2B) was constructed by attaching magainin II (MG2) to bombesin at its N-terminus. The peptides were synthesized using Fmoc-chemistry. The in vitro cytotoxicity of the peptide in cancer cells was quantitatively determined using the CCK-8 cell counting kit. Moreover, the in vivo antitumor effect of the peptide was determined in tumor xenograft models. The IC(50) of MG2B for cancer cells (10-15 μmol/L) was at least 10 times lower than the IC(50) of unconjugated MG2 (125 μmol/L). Moreover, the binding affinity of MG2B for cancer cells was higher than that of unconjugated MG2. In contrast, conjugation to a bombesin analog lacking the receptor-binding domain failed to increase the cytotoxicity of MG2, suggesting that bombesin conjugation enhances the cytotoxicity of MG2 in cancer cells through improved binding. Indeed, MG2B selectively induced cell death in cancer cells in vitro with the IC(50) ranging from 10 to 15 μmol/L, which was about 6-10 times lower than the IC(50) for normal cells. MG2B (20 mg/kg per day, intratumorally injected for 5 d) also exhibited antitumor effects in mice bearing MCF-7 tumor grafts. The mean weights of tumor grafts in MG2B- and PBS-treated mice were 0.21±0.05 g and 0.59±0.12 g, respectively. The results suggest that conjugation of AMPs to bombesin might be an alternative approach for targeted cancer therapy.

Rational Design of a Transferrin-Binding Peptide Sequence Tailored to Targeted Nanoparticle Internalization.

PubMed

Santi, Melissa; Maccari, Giuseppe; Mereghetti, Paolo; Voliani, Valerio; Rocchiccioli, Silvia; Ucciferri, Nadia; Luin, Stefano; Signore, Giovanni

2017-02-15

The transferrin receptor (TfR) is a promising target in cancer therapy owing to its overexpression in most solid tumors and on the blood-brain barrier. Nanostructures chemically derivatized with transferrin are employed in TfR targeting but often lose their functionality upon injection in the bloodstream. As an alternative strategy, we rationally designed a peptide coating able to bind transferrin on suitable pockets not involved in binding to TfR or iron by using an iterative multiscale-modeling approach coupled with quantitative structure-activity and relationship (QSAR) analysis and evolutionary algorithms. We tested that selected sequences have low aspecific protein adsorption and high binding energy toward transferrin, and one of them is efficiently internalized in cells with a transferrin-dependent pathway. Furthermore, it promotes transferrin-mediated endocytosis of gold nanoparticles by modifying their protein corona and promoting oriented adsorption of transferrin. This strategy leads to highly effective nanostructures, potentially useful in diagnostic and therapeutic applications, which exploit (and do not suffer) the protein solvation for achieving a better targeting.

Mitochondrial Metabolism as a Treatment Target in Anaplastic Thyroid Cancer

PubMed Central

Johnson, Jennifer M; Lai, Stephen Y.; Cotzia, Paolo; Cognetti, David; Luginbuhl, Adam; Pribitkin, Edmund A.; Zhan, Tingting; Mollaee, Mehri; Domingo-Vidal, Marina; Chen, Yunyun; Campling, Barbara; Bar-Ad, Voichita; Birbe, Ruth; Tuluc, Madalina; Outschoorn, Ubaldo Martinez; Curry, Joseph

2015-01-01

Aims Anaplastic thyroid cancer (ATC) is one of the most aggressive human cancers. Key signal transduction pathways that regulate mitochondrial metabolism are frequently altered in ATC. Our goal was to determine the mitochondrial metabolic phenotype of ATC by studying markers of mitochondrial metabolism, specifically Monocarboxylate Transporter 1 (MCT1) and Translocase of the Outer Mitochondrial Membrane Member 20 (TOMM20). Methods Staining patterns of MCT1 and TOMM20 in 35 human thyroid samples (15 ATC, 12 papillary thyroid cancer (PTC), and 8 non-cancerous thyroid) and 9 ATC mouse orthotopic xenografts were assessed by visual and Aperio digital scoring. Staining patterns of areas involved with cancer versus areas with no evidence of cancer were evaluated independently where available. Results MCT1 is highly expressed in human anaplastic thyroid cancer when compared to both non-cancerous thyroid tissues and papillary thyroid cancers (p<0.001 for both). TOMM20 is also highly expressed in both ATC and PTC compared to non-cancerous thyroid tissue (p<0.01 for both). High MCT1 and TOMM20 expression is also found in ATC mouse xenograft tumors compared to non-cancerous thyroid tissue (p<0.001). These xenograft tumors have high 13C- pyruvate uptake. Conclusions Anaplastic thyroid cancer has metabolic features that distinguish it from PTC and non-cancerous thyroid tissue, including high expression of MCT1 and TOMM20. PTC has low expression of MCT1 and non-cancerous thyroid tissue has low expression of both MCT1 and TOMM20. This work suggests that MCT1 blockade may specifically target ATC cells presenting an opportunity for a new drug target. PMID:26615136

Mitochondrial Metabolism as a Treatment Target in Anaplastic Thyroid Cancer.

PubMed

Johnson, Jennifer M; Lai, Stephen Y; Cotzia, Paolo; Cognetti, David; Luginbuhl, Adam; Pribitkin, Edmund A; Zhan, Tingting; Mollaee, Mehri; Domingo-Vidal, Marina; Chen, Yunyun; Campling, Barbara; Bar-Ad, Voichita; Birbe, Ruth; Tuluc, Madalina; Martinez Outschoorn, Ubaldo; Curry, Joseph

2015-12-01

Anaplastic thyroid cancer (ATC) is one of the most aggressive human cancers. Key signal transduction pathways that regulate mitochondrial metabolism are frequently altered in ATC. Our goal was to determine the mitochondrial metabolic phenotype of ATC by studying markers of mitochondrial metabolism, specifically monocarboxylate transporter 1 (MCT1) and translocase of the outer mitochondrial membrane member 20 (TOMM20). Staining patterns of MCT1 and TOMM20 in 35 human thyroid samples (15 ATC, 12 papillary thyroid cancer [PTC], and eight non-cancerous thyroid) and nine ATC mouse orthotopic xenografts were assessed by visual and Aperio digital scoring. Staining patterns of areas involved with cancer versus areas with no evidence of cancer were evaluated independently where available. MCT1 is highly expressed in human anaplastic thyroid cancer when compared to both non-cancerous thyroid tissues and papillary thyroid cancers (P<.001 for both). TOMM20 is also highly expressed in both ATC and PTC compared to non-cancerous thyroid tissue (P<.01 for both). High MCT1 and TOMM20 expression is also found in ATC mouse xenograft tumors compared to non-cancerous thyroid tissue (P<.001). These xenograft tumors have high (13)C- pyruvate uptake. ATC has metabolic features that distinguish it from PTC and non-cancerous thyroid tissue, including high expression of MCT1 and TOMM20. PTC has low expression of MCT1 and non-cancerous thyroid tissue has low expression of both MCT1 and TOMM20. This work suggests that MCT1 blockade may specifically target ATC cells presenting an opportunity for a new drug target. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

A Review of Potential Marine-derived Hypotensive and Anti-obesity Peptides.

PubMed

Manikkam, V; Vasiljevic, T; Donkor, O N; Mathai, M L

2016-01-01

Bioactive peptides are food derived components, usually consisting of 3-20 amino acids, which are inactive when incorporated within their parent protein. Once liberated by enzymatic or chemical hydrolysis, during food processing and gastrointestinal transit, they can potentially provide an array of health benefits to the human body. Owing to an unprecedented increase in the worldwide incidence of obesity and hypertension, medical researchers are focusing on the hypotensive and anti-obesity properties of nutritionally derived bioactive peptides. The role of the renin-angiotensin system has long been established in the aetiology of metabolic diseases and hypertension. Targeting the renin-angiotensin system by inhibiting the activity of angiotensin-converting enzyme (ACE) and preventing the formation of angiotensin II can be a potential therapeutic approach to the treatment of hypertension and obesity. Fish-derived proteins and peptides can potentially be excellent sources of bioactive components, mainly as a source of ACE inhibitors. However, increased use of marine sources, poses an unsustainable burden on particular fish stocks, so, the underutilized fish species and by-products can be exploited for this purpose. This paper provides an overview of the techniques involved in the production, isolation, purification, and characterization of bioactive peptides from marine sources, as well as the evaluation of the ACE inhibitory (ACE-I) activity and bioavailability.