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1.
Proc Natl Acad Sci U S A ; 120(5): e2214883120, 2023 Jan 31.
Article in English | MEDLINE | ID: mdl-36706221

ABSTRACT

Sex peptide (SP), a seminal fluid protein of Drosophila melanogaster males, has been described as driving a virgin-to-mated switch in females, through eliciting an array of responses including increased egg laying, activity, and food intake and a decreased remating rate. While it is known that SP achieves this, at least in part, by altering neuronal signaling in females, the genetic architecture and temporal dynamics of the female's response to SP remain elusive. We used a high-resolution time series RNA-sequencing dataset of female heads at 10 time points within the first 24 h after mating to learn about the genetic architecture, at the gene and exon levels, of the female's response to SP. We find that SP is not essential to trigger early aspects of a virgin-to-mated transcriptional switch, which includes changes in a metabolic gene regulatory network. However, SP is needed to maintain and diversify metabolic changes and to trigger changes in a neuronal gene regulatory network. We further find that SP alters rhythmic gene expression in females and suggests that SP's disruption of the female's circadian rhythm might be key to its widespread effects.


Subject(s)
Circadian Clocks , Drosophila Proteins , Animals , Male , Female , Drosophila melanogaster/metabolism , Drosophila Proteins/metabolism , Spermatozoa/metabolism , Circadian Clocks/genetics , Time Factors , Peptides/metabolism , Gene Expression Profiling , Sexual Behavior, Animal/physiology
2.
Nat Commun ; 14(1): 423, 2023 Jan 26.
Article in English | MEDLINE | ID: mdl-36702874

ABSTRACT

Auxin efflux through plasma-membrane-integral PIN-FORMED (PIN) carriers is essential for plant tissue organization and tightly regulated. For instance, a molecular rheostat critically controls PIN-mediated auxin transport in developing protophloem sieve elements of Arabidopsis roots. Plasma-membrane-association of the rheostat proteins, BREVIS RADIX (BRX) and PROTEIN KINASE ASSOCIATED WITH BRX (PAX), is reinforced by interaction with PHOSPHATIDYLINOSITOL-4-PHOSPHATE-5-KINASE (PIP5K). Genetic evidence suggests that BRX dampens autocrine signaling of CLAVATA3/EMBRYO SURROUNDING REGION-RELATED 45 (CLE45) peptide via its receptor BARELY ANY MERISTEM 3 (BAM3). How excess CLE45-BAM3 signaling interferes with protophloem development and whether it does so directly or indirectly remains unclear. Here we show that rheostat polarity is independent of PIN polarity, but interdependent with PIP5K. Catalytically inactive PIP5K confers rheostat polarity without reinforcing its localization, revealing a possible PIP5K scaffolding function. Moreover, PIP5K and PAX cooperatively control local PIN abundance. We further find that CLE45-BAM3 signaling branches via RLCK-VII/PBS1-LIKE (PBL) cytoplasmic kinases to destabilize rheostat localization. Our data thus reveal antagonism between CLE45-BAM3-PBL signaling and PIP5K that converges on auxin efflux regulation through dynamic control of PAX polarity. Because second-site bam3 mutation suppresses root as well as shoot phenotypes of pip5k mutants, CLE peptide signaling likely modulates phosphoinositide-dependent processes in various developmental contexts.


Subject(s)
Arabidopsis Proteins , Arabidopsis , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Phosphatidylinositols/metabolism , Plant Roots/metabolism , Arabidopsis/metabolism , Indoleacetic Acids/metabolism , Peptides/metabolism , Gene Expression Regulation, Plant , Membrane Proteins/metabolism
3.
Sci Adv ; 9(4): eade5800, 2023 Jan 25.
Article in English | MEDLINE | ID: mdl-36696493

ABSTRACT

CD4+ T cells specific for cereal gluten proteins are key players in celiac disease (CeD) pathogenesis. While several CeD-relevant gluten T cell epitopes have been identified, epitopes recognized by a substantial proportion of gluten-reactive T cells remain unknown. The identification of such CeD-driving gluten epitopes is important for the food industry and in clinical settings. Here, we have combined the knowledge of a distinct phenotype of gluten-reactive T cells and key features of known gluten epitopes for the discovery of unknown epitopes. We tested 42 wheat gluten-reactive T cell clones, isolated on the basis of their distinct phenotype and with no reactivity to known epitopes, against a panel of synthetic peptides bioinformatically identified from a wheat gluten protein database. We were able to assign reactivity to 10 T cell clones and identified a 9-nucleotide oligomer core region of five previously uncharacterized gliadin/glutenin epitopes. This work represents an advance in the effort to identify CeD-driving gluten epitopes.


Subject(s)
Celiac Disease , Humans , Celiac Disease/metabolism , Epitopes, T-Lymphocyte , Glutens , Gliadin/genetics , Gliadin/metabolism , Peptides/metabolism
4.
Front Endocrinol (Lausanne) ; 13: 1003017, 2022.
Article in English | MEDLINE | ID: mdl-36686419

ABSTRACT

Cholesterol is the precursor of all steroid hormones, and the entry of cholesterol into the mitochondria is the rate-limiting step of steroidogenesis. Voltage-dependent anion channel (VDAC1) is an outer mitochondrial protein part of a multiprotein complex that imports cholesterol. We previously reported that intratesticular administration of a 25 amino acid peptide blocking the interaction between 14-3-3ϵ with VDAC1 increased circulating levels of testosterone. This fusion peptide was composed of a HIV-1 transactivator of transcription (TAT) protein transduction domain cell-penetrating peptide, a glycine linker, and amino acids 159-172 of VDAC1 (TV159-172). Here, we describe the development of a family of small molecules that increase circulating testosterone levels after an oral administration. We first characterized an animal model where TV159-172 was delivered subcutaneously. This subcutaneous model allowed us to study the interactions between TV159-172 and the hypothalamus-pituitary-gonadal axis (HPG) and identify the biologically active core of TV159-172. The core consisted of the tetrapeptide RVTQ, which we used as a platform to design synthetic peptide derivatives that can be administered orally. We developed a second animal model to test various derivatives of RVTQ and found 11 active compounds. Dose-response experiments identified 4 synthetic peptides that robustly increased androgen levels in a specific manner. We selected RdVTQ as the leading VDAC1-core derivative and profiled the response across the lifespan of Brown-Norway rats. In summary, we present the development of a new class of therapeutics that act within the HPG axis to increase testosterone levels specifically. This new class of small molecules self-regulates, preventing abuse.


Subject(s)
Apoptosis , Voltage-Dependent Anion Channel 1 , Rats , Male , Animals , Voltage-Dependent Anion Channel 1/chemistry , Voltage-Dependent Anion Channel 1/metabolism , Peptides/metabolism , Voltage-Dependent Anion Channels , Testosterone , Administration, Oral
5.
PLoS One ; 18(1): e0280529, 2023.
Article in English | MEDLINE | ID: mdl-36689407

ABSTRACT

Much is known about environmental influences on metabolism and systemic insulin levels. Less is known about how those influences are translated into molecular mechanisms regulating insulin production. To better understand the molecular mechanisms we generated marked cells homozygous for a null mutation in the Drosophila TGF-ß signal transducer dSmad2 in unmated adult females. We then conducted side-by-side single cell comparisons of the pixel intensity of two Drosophila insulin-like peptides (dILP2 and dILP5) in dSmad2- mutant and wild type insulin producing cells (IPCs). The analysis revealed multiple features of dSmad2 regulation of dILPs. In addition, we discovered that dILP5 is expressed and regulated by dSmad2 in circadian pacemaker cells (CPCs). Outcomes of regulation by dSmad2 differ between dILP2 and dILP5 within IPCs and differ for dILP5 between IPCs and CPCs. Modes of dSmad2 regulation differ between dILP2 and dILP5. dSmad2 antagonism of dILP2 in IPCs is robust but dSmad2 regulation of dILP5 in IPCs and CPCs toggles between antagonism and agonism depending upon dSmad2 dosage. Companion studies of dILP2 and dILP5 in the IPCs of dCORL mutant (fussel in Flybase and SKOR in mammals) and upd2 mutant unmated adult females showed no significant difference from wild type. Taken together, the data suggest that dSmad2 regulates dILP2 and dILP5 via distinct mechanisms in IPCs (antagonist) and CPCs (agonist) and in unmated adult females that dSmad2 acts independently of dCORL and upd2.


Subject(s)
Drosophila Proteins , Drosophila melanogaster , Animals , Female , Drosophila melanogaster/genetics , Drosophila Proteins/metabolism , Drosophila/metabolism , Insulin/metabolism , Peptides/metabolism , Mammals/metabolism
6.
Methods Enzymol ; 679: 363-380, 2023.
Article in English | MEDLINE | ID: mdl-36682871

ABSTRACT

Primary kinetic isotope effects (KIEs) provide unique insight into enzymatic reactions, as they can reveal rate-limiting steps and detailed chemical mechanisms. HIF hydroxylases, part of a family of 2-oxoglutarate (2OG) oxygenases are central to the regulation of many crucial biological processes through O2-sensing, but present a challenge to monitor due to the large size of the protein substrate and the similarity between native and hydroxylated substrate. MALDI-TOF MS is a convenient tool to measure peptide masses, which can also be used to measure the discontinuous kinetics of peptide hydroxylation for Factor Inhibiting HIF (FIH). Using this technique, rate data can be observed from the mole-fraction of CTAD and CTAD-OH in small volumes, allowing noncompetitive H/D KIEs to be measured. Slow dCTAD substrate leads to extensive uncoupling of O2 consumption from peptide hydroxylation, leading to enzyme autohydroxylation, which is observed using UV-vis spectroscopy. Simultaneously measuring both the normal product, CTAD-OH, and the uncoupled product, autohydroxylated enzyme, the KIE on the microscopic step of hydrogen atom transfer (HAT) can be estimated. MALDI-MS analysis is a strong method for monitoring reactions that hydroxylate peptides, and can be generalized to other similar reactions, and simultaneous kinetic detection of branched products can provide valuable insight on microscopic KIEs at intermediate mechanistic steps.


Subject(s)
Peptides , Repressor Proteins , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Repressor Proteins/chemistry , Kinetics , Hydroxylation , Peptides/metabolism
7.
Molecules ; 28(2)2023 Jan 09.
Article in English | MEDLINE | ID: mdl-36677709

ABSTRACT

Pacific oyster (Crassostrea gigas), an abundant bivalve consumed across the Pacific, is known to possess a wide range of bioactivities. While there has been some work on its bioactive hydrolysates, the discovery of bioactive peptides (BAPs) remains limited due to the resource-intensive nature of the existing discovery pipeline. To overcome this constraint, in silico-based prospecting is employed to accelerate BAP discovery. Major oyster proteins were digested virtually under a simulated gastrointestinal condition to generate virtual peptide products that were screened against existing databases for peptide bioactivities, toxicity, bitterness, stability in the intestine and in the blood, and novelty. Five peptide candidates were shortlisted showing antidiabetic, anti-inflammatory, antihypertensive, antimicrobial, and anticancer potential. By employing this approach, oyster BAPs were identified at a faster rate, with a wider applicability reach. With the growing market for peptide-based nutraceuticals, this provides an efficient workflow for candidate scouting and end-use investigation for targeted functional product preparation.


Subject(s)
Anti-Infective Agents , Crassostrea , Animals , Crassostrea/metabolism , Peptides/pharmacology , Peptides/metabolism , Seafood , Anti-Infective Agents/metabolism
8.
Viruses ; 15(1)2023 Jan 12.
Article in English | MEDLINE | ID: mdl-36680255

ABSTRACT

The ß-Coronavirus mouse hepatitis virus (MHV-A59)-RSA59 has a patent stretch of fusion peptide (FP) containing two consecutive central prolines (PP) in the S2 domain of the Spike protein. Our previous studies compared the PP-containing fusogenic-demyelinating strain RSA59(PP) to its one proline-deleted mutant strain RSA59(P) and one proline-containing non-fusogenic non-demyelinating parental strain RSMHV2(P) to its one proline inserted mutant strain RSMHV2(PP). These studies highlighted the crucial role of PP in fusogenicity, hepato-neuropathogenesis, and demyelination. Computational studies combined with biophysical data indicate that PP at the center of the FP provides local rigidity while imparting global fluctuation to the Spike protein that enhances the fusogenic properties of RSA59(PP) and RSMHV2(PP). To elaborate on the understanding of the role of PP in the FP of MHV, the differential neuroglial tropism of the PP and P mutant strains was investigated. Comparative studies demonstrated that PP significantly enhances the viral tropism for neurons, microglia, and oligodendrocytes. PP, however, is not essential for viral tropism for either astroglial or oligodendroglial precursors or the infection of meningeal fibroblasts in the blood-brain and blood-CSF barriers. PP in the fusion domain is critical for promoting gliopathy, making it a potential region for designing antivirals for neuro-COVID therapy.


Subject(s)
Murine hepatitis virus , Spike Glycoprotein, Coronavirus , Viral Tropism , Animals , Mice , Murine hepatitis virus/physiology , Peptides/metabolism , Proline , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Viral Envelope Proteins/metabolism
9.
Int J Mol Sci ; 24(2)2023 Jan 12.
Article in English | MEDLINE | ID: mdl-36675040

ABSTRACT

Sacha inchi meal (SIM) is a by-product of sacha inchi (considered as a "super-food") processing. In previous studies, we found that SIM protein hydrolysates exhibited pancreatic lipase inhibition activity. In this study, 10 bioactive peptides from those hydrolysates were identified. The top five peptides (NLYYKVV (NV-7), WWYVK (WK-5), WLLMWPYK (WK-8), EGLLMWPY (EY-8), and FPFFGYVWK (FK-9)) with strong pancreatic lipase inhibition activity had IC50 values of 34.01-246.50 µM, and displayed various inhibition types (mixed, non-competitive, and competitive type) by enzyme inhibition kinetics analysis. Fluorescence quenching analysis demonstrated that the interaction between the peptides and pancreatic lipase was mainly hydrogen bond and van der Waals force. The key residues involved in the peptide-enzyme interaction were determined by molecular docking. Moreover, the top two peptides were found to significantly inhibit fat accumulation and regulate lipid metabolism by alleviating the level of reactive oxygen species in HepG2 cells. Collectively, sacha inchi meal-derived peptides displayed potent lipid-lowering activity and could be used as materials of functional food.


Subject(s)
Lipid Metabolism , Plant Oils , Plant Oils/metabolism , Molecular Docking Simulation , Peptides/pharmacology , Peptides/metabolism
10.
Int J Mol Sci ; 24(2)2023 Jan 12.
Article in English | MEDLINE | ID: mdl-36675049

ABSTRACT

Enterocin DD14 (EntDD14) is a two-peptide leaderless bacteriocin produced by the Enterococcus faecalis 14 strain previously isolated from meconium. This bacteriocin is mainly active against Gram-positive bacteria. Leaderless bacteriocins do not undergo post-translational modifications and are therefore immediately active after their synthesis. As a result, the cells that produce such bacteriocins have developed means of protection against them which often involve transport systems. In this and our previous work, we constructed different mutants deleted in the genes involved in the transport functions, thus covering all the supposed components of this transport system, using Listeria innocua ATCC 33090 as the indicator strain to assess the activity of externalized EntDD14. We also assessed the self-resistance of the WT and all its engineered derivative mutants against EntDD14, provided extracellularly, in order to evaluate their self-resistance. The results obtained highlight that the ABC transporter constituted by the DdG, H, I, and J proteins contributes to EntDD14 export as well as resistance to an external supply of EntDD14. Our results also have established the essential role of the DdE and DdF proteins as primary transporters dedicated to the externalization of EntDD14. Moreover, the in silico data showed that DdE and DdF appear to assemble in a formation that forms an essential channel for the exit of EntDD14. This channel DdEF may interact with the ABC transporter DdGHIJ in order to control the flow of bacteriocin across the membrane, although the nature of this interaction remains to be elucidated.


Subject(s)
Bacteriocins , Bacteriocins/genetics , Bacteriocins/pharmacology , Bacteriocins/metabolism , Peptides/metabolism , Enterococcus faecalis/genetics , Enterococcus faecalis/metabolism , ATP-Binding Cassette Transporters/metabolism
11.
Int J Mol Sci ; 24(2)2023 Jan 16.
Article in English | MEDLINE | ID: mdl-36675272

ABSTRACT

Tortoiseshell and deer antler gelatin has been used to treat bone diseases in Chinese society. A pepsin-digested gelatin peptide with osteoblast-proliferation-stimulating properties was identified via LC-MS/MS. The resulting pentapeptide, TSKYR, was presumably subjected to further degradation into TSKY, TSK, and YR fragments in the small intestine. The above four peptides were chemically synthesized. Treatment of tripeptide TSK can lead to a significant 30- and 50-fold increase in the mineralized nodule area and density in osteoblast cells and a 47.5% increase in the number of chondrocyte cells. The calcium content in tortoiseshell was relatively higher than in human soft tissue. The synergistic effects of calcium ions and the peptides were observed for changes in osteoblast proliferation and differentiation. Moreover, these peptides can enhance the expression of RUNX2, OCN, FGFR2, and FRFR3 genes in osteoblasts, and aggrecan and collagen type II in chondrocyte (patent pending).


Subject(s)
Antlers , Deer , Humans , Animals , Gelatin/pharmacology , Gelatin/metabolism , Antlers/chemistry , Chromatography, Liquid , Calcium/metabolism , Tandem Mass Spectrometry , Peptides/metabolism
12.
Molecules ; 28(2)2023 Jan 04.
Article in English | MEDLINE | ID: mdl-36677542

ABSTRACT

The neuropeptides orexin A and B regulate various vital functions of the body, such as sleep/wake states, metabolism, and energy homeostasis. A loss of their physiological activity, with reduced ability to recognize their receptors, is suspected to be associated with oxidative stress conditions. These are related to excessive presence of reactive oxygen and nitrogen species, as well as of reactive lipoxidation byproducts. With the aim of evaluating the effects of oxidative stress on the secondary structure of orexin peptides, orexin B was synthesized and characterized by circular dichroism spectroscopy under different conditions. In aqueous solution it presents an unordered conformation, while in a membrane mimetic environment it assumes a helical structure. The effects of oxidative stress were evaluated exposing it to both oxygen and nitrogen radicals as well as to lipoxidation byproducts. The results showed that ROS, but not NRS, induced appreciable conformational changes, and only in the membrane mimetic environment. Lipoxidation byproducts, instead, led to secondary structure modifications much more evident than those induced by the direct action of ROS and RNS, and in both analyzed media. Additionally, MALDI-TOF analyses detected mass variations in the peptide attributable to oxidation of the C-terminal Met residue and deamination of asparagine in the Asn-His sequence. Taken together, all these data seem to confirm the involvement of oxidative processes in dysfunctions of the orexinergic system.


Subject(s)
Oxidative Stress , Peptides , Orexins/metabolism , Reactive Oxygen Species/metabolism , Circular Dichroism , Peptides/metabolism , Oxygen
13.
Elife ; 122023 Jan 20.
Article in English | MEDLINE | ID: mdl-36661395

ABSTRACT

The regulatory and effector functions of T cells are initiated by the binding of their cell-surface T cell receptor (TCR) to peptides presented by major histocompatibility complex (MHC) proteins on other cells. The specificity of TCR:peptide-MHC interactions, thus, underlies nearly all adaptive immune responses. Despite intense interest, generalizable predictive models of TCR:peptide-MHC specificity remain out of reach; two key barriers are the diversity of TCR recognition modes and the paucity of training data. Inspired by recent breakthroughs in protein structure prediction achieved by deep neural networks, we evaluated structural modeling as a potential avenue for prediction of TCR epitope specificity. We show that a specialized version of the neural network predictor AlphaFold can generate models of TCR:peptide-MHC interactions that can be used to discriminate correct from incorrect peptide epitopes with substantial accuracy. Although much work remains to be done for these predictions to have widespread practical utility, we are optimistic that deep learning-based structural modeling represents a path to generalizable prediction of TCR:peptide-MHC interaction specificity.


Subject(s)
Peptides , Receptors, Antigen, T-Cell , Receptors, Antigen, T-Cell/metabolism , Peptides/metabolism , T-Lymphocytes , Epitopes/metabolism , Protein Binding
14.
J Transl Med ; 21(1): 36, 2023 Jan 20.
Article in English | MEDLINE | ID: mdl-36670507

ABSTRACT

MOTS-c is a peptide encoded by the short open reading frame of the mitochondrial 12S rRNA gene. It is significantly expressed in response to stress or exercise and translocated to the nucleus, where it regulates the expression of stress adaptation-related genes with antioxidant response elements (ARE). MOTS-c mainly acts through the Folate-AICAR-AMPK pathway, thereby influencing energy metabolism, insulin resistance, inflammatory response, exercise, aging and aging-related pathologies. Because of the potential role of MOTS-c in maintaining energy and stress homeostasis to promote healthy aging, especially in view of the increasing aging of the global population, it is highly pertinent to summarize the relevant studies. This review summarizes the retrograde signaling of MOTS-c toward the nucleus, the regulation of energy metabolism, stress homeostasis, and aging-related pathological processes, as well as the underlying molecular mechanisms.


Subject(s)
Insulin Resistance , Mitochondria , Humans , Mitochondria/metabolism , Peptides/metabolism , Aging , Homeostasis , Insulin Resistance/physiology , Transcription Factors/metabolism , Mitochondrial Proteins/genetics
15.
J Plant Physiol ; 281: 153922, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36669364

ABSTRACT

CLE (CLAVATA3/ENDOSPERM SURROUNDING REGION-related) peptides are systemic regulators of legume-rhizobium symbiosis that negatively control the number of nitrogen-fixing nodules. CLE peptides are produced in the root in response to rhizobia inoculation and/or nitrate treatment and are transported to the shoot where they are recognized by the CLV1-like (CLAVATA1-like) receptor kinase. As a result, a shoot-derived signaling pathway is activated that inhibits subsequent nodule development in the root. In Medicago truncatula, MtCLE35 is activated in response to rhizobia and nitrate treatment and the overexpression of this gene systemically inhibits nodulation. The inhibitory effect of MtCLE35 overexpression is dependent on the CLV1-like receptor kinase MtSUNN (SUPER NUMERIC NODULES), suggesting that MtSUNN could be involved in the reception of the MtCLE35 peptide. Yet little is known about the downstream genes regulated by a MtCLE35-activated response in the root. In order to identify genes whose expression levels could be regulated by the MtCLE35-MtSUNN pathway, we performed a MACE-Seq (Massive Analysis of cDNA Ends) transcriptomic analysis of MtCLE35-overexpressing roots. Among upregulated genes, the gene MtSUNN that encodes a putative receptor of MtCLE35 was detected. Moreover, we found that MtSUNN, as well as several other differentially expressed genes, were upregulated locally in MtCLE35-overexpressing roots whereas the MtTML1 and MtTML2 genes were upregulated systemically. Our data suggest that MtCLE35 has both local and systemic effects on target genes in the root.


Subject(s)
Medicago truncatula , Medicago truncatula/metabolism , Plant Root Nodulation/genetics , Nitrates/metabolism , Signal Transduction/genetics , Peptides/genetics , Peptides/metabolism , Symbiosis , Gene Expression Regulation, Plant , Plant Proteins/genetics , Plant Proteins/metabolism , Root Nodules, Plant/genetics , Root Nodules, Plant/metabolism , Plant Roots/genetics , Plant Roots/metabolism
16.
Cell Mol Biol Lett ; 28(1): 4, 2023 Jan 19.
Article in English | MEDLINE | ID: mdl-36658472

ABSTRACT

BACKGROUND: Ischemia-reperfusion injury (IRI) is an inevitable process in renal transplantation that significantly increases the risk of delayed graft function, acute rejection, and even graft loss. Formyl peptide receptor 2 (FPR2) is an important receptor in multiple septic and aseptic injuries, but its functions in kidney IRI are still unclear. This study was designed to reveal the pathological role of FPR2 in kidney IRI and its functional mechanisms. METHODS: To explore the mechanism of FPR2 in kidney IRI, the model rats were sacrificed after IRI surgery. Immunofluorescence, enzyme-linked immunosorbent assays, and western blotting were used to detect differences in the expression of FPR2 and its ligands between the IRI and control groups. WRW4 (WRWWWW-NH2), a specific antagonist of FPR2, was administered to kidney IRI rats. Kidney function and pathological damage were detected to assess kidney injury and recovery. Flow cytometry was used to quantitatively compare neutrophil infiltration among the experimental groups. Mitochondrial formyl peptides (mtFPs) were synthesized and administered to primary rat neutrophils together with the specific FPR family antagonist WRW4 to verify our hypothesis in vitro. Western blotting and cell function assays were used to examine the functions and signaling pathways that FPR2 mediates in neutrophils. RESULTS: FPR2 was activated mainly by mtFPs during the acute phase of IRI, mediating neutrophil migration and reactive oxygen species production in the rat kidney through the ERK1/2 pathway. FPR2 blockade in the early phase protected rat kidneys from IRI. CONCLUSIONS: mtFPs activated FPR2 during the acute phase of IRI and mediated rat kidney injury by activating the migration and reactive oxygen species generation of neutrophils through the ERK1/2 pathway.


Subject(s)
Neutrophils , Receptors, Formyl Peptide , Reperfusion Injury , Animals , Rats , MAP Kinase Signaling System , Neutrophils/metabolism , Peptides/metabolism , Reactive Oxygen Species/metabolism , Receptors, Formyl Peptide/metabolism , Reperfusion Injury/metabolism
17.
Nature ; 613(7945): 712-720, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36653451

ABSTRACT

Ribosomes are produced in large quantities during oogenesis and are stored in the egg. However, the egg and early embryo are translationally repressed1-4. Here, using mass spectrometry and cryo-electron microscopy analyses of ribosomes isolated from zebrafish (Danio rerio) and Xenopus laevis eggs and embryos, we provide molecular evidence that ribosomes transition from a dormant state to an active state during the first hours of embryogenesis. Dormant ribosomes are associated with four conserved factors that form two modules, consisting of Habp4-eEF2 and death associated protein 1b (Dap1b) or Dap in complex with eIF5a. Both modules occupy functionally important sites and act together to stabilize ribosomes and repress translation. Dap1b (also known as Dapl1 in mammals) is a newly discovered translational inhibitor that stably inserts into the polypeptide exit tunnel. Addition of recombinant zebrafish Dap1b protein is sufficient to block translation and reconstitute the dormant egg ribosome state in a mammalian translation extract in vitro. Thus, a developmentally programmed, conserved ribosome state has a key role in ribosome storage and translational repression in the egg.


Subject(s)
Ribosomes , Zebrafish , Animals , Zebrafish/metabolism , Cryoelectron Microscopy/methods , Ribosomes/metabolism , Peptides/metabolism , Mammals/metabolism , Protein Biosynthesis
18.
Acta Cir Bras ; 37(12): e371203, 2023.
Article in English | MEDLINE | ID: mdl-36651428

ABSTRACT

PURPOSE: Although mechanical ventilation is an essential support for acute respiratory distress syndrome (ARDS), ventilation also leads to ventilator-induced lung injury (VILI). This study aimed to estimate the effect and mechanism of Annexin A1 peptide (Ac2-26) on VILI in ARDS rats. METHODS: Thirty-two rats were randomized into the sham (S), mechanical ventilation (V), mechanical ventilation/Ac2-26 (VA), and mechanical ventilation/Ac2-26/L-NIO (VAL) groups. The S group only received anesthesia, and the other three groups received endotoxin and then ventilation for 4 h. Rats in the V, VA and VAL groups received saline, Ac2-26, and A c2-26/N5-(1-iminoethyl)-l-ornithine (L-NIO), respectively. RESULTS: All indexes deteriorated in the V, VA and VAL groups compared with the S group. Compared with V group, the PaO2/FiO2 ratio was increased, but the wet-to-dry weight ratio and protein levels in bronchoalveolar lavage fluid were decreased in the VA group. The inflammatory cells and proinflammatory factors were reduced by Ac2-26. The oxidative stress response, lung injury and apoptosis were also decreased by Ac2-26 compared to V group. All improvements of Ac2-26 were partly reversed by L-NIO. CONCLUSIONS: Ac2-26 mitigates VILI in ARDS rats and partly depended on the endothelial nitric oxide synthase pathway.


Subject(s)
Annexin A1 , Respiratory Distress Syndrome , Ventilator-Induced Lung Injury , Rats , Animals , Annexin A1/pharmacology , Annexin A1/metabolism , Nitric Oxide Synthase Type III/metabolism , Lung/metabolism , Ventilator-Induced Lung Injury/drug therapy , Bronchoalveolar Lavage Fluid , Respiratory Distress Syndrome/drug therapy , Respiratory Distress Syndrome/metabolism , Peptides/pharmacology , Peptides/therapeutic use , Peptides/metabolism
19.
Commun Biol ; 6(1): 59, 2023 Jan 17.
Article in English | MEDLINE | ID: mdl-36650277

ABSTRACT

Tumor suppressor p53 prevents tumorigenesis by promoting cell cycle arrest and apoptosis through transcriptional regulation. Dysfunction of p53 occurs frequently in human cancers. Thus, p53 becomes one of the most promising targets for anticancer treatment. A bacterial effector protein azurin triggers tumor suppression by stabilizing p53 and elevating its basal level. However, the structural and mechanistic basis of azurin-mediated tumor suppression remains elusive. Here we report the atomic details of azurin-mediated p53 stabilization by combining X-ray crystallography with nuclear magnetic resonance. Structural and mutagenic analysis reveals that the p28 region of azurin, which corresponds to a therapeutic peptide, significantly contributes to p53 binding. This binding stabilizes p53 by disrupting COP1-mediated p53 ubiquitination and degradation. Using the structure-based design, we obtain several affinity-enhancing mutants that enable amplifying the effect of azurin-induced apoptosis. Our findings highlight how the structure of the azurin-p53 complex can be leveraged to design azurin derivatives for cancer therapy.


Subject(s)
Azurin , Tumor Suppressor Protein p53 , Ubiquitination , Humans , Azurin/chemistry , Bacterial Proteins/chemistry , Peptides/metabolism , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism
20.
Commun Biol ; 6(1): 60, 2023 Jan 17.
Article in English | MEDLINE | ID: mdl-36650239

ABSTRACT

There continues to be a need for cancer-specific ligands that can deliver a wide variety of therapeutic cargos. Ligands demonstrating both tumor-specificity and the ability to mediate efficient cellular uptake of a therapeutic are critical to expand targeted therapies. We previously reported the selection of a peptide from a peptide library using a non-small cell lung cancer (NSCLC) cell line as the target. Here we optimize our lead peptide by a series of chemical modifications including truncations, N-terminal capping, and changes in valency. The resultant 10 amino acid peptide has an affinity of <40 nM on four different NSCLC cell lines as a monomer and is stable in human serum for >48 h. The peptide rapidly internalizes upon cell binding and traffics to the lysosome. The peptide homes to a tumor in an animal model and is retained up to 72 h. Importantly, we demonstrate that the peptide can deliver the cytotoxic protein saporin specifically to cancer cells in vitro and in vivo, resulting in an effective anticancer agent.


Subject(s)
Antineoplastic Agents , Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Animals , Humans , Carcinoma, Non-Small-Cell Lung/drug therapy , Lung Neoplasms/drug therapy , Lung Neoplasms/pathology , Peptides/metabolism , Peptide Library , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use
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