Conjugation of peptides to short-acyl-chain ceramides for delivery across mucosal cell barriers.
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ABSTRACT:
SUBMITTER: Duclos RI
PROVIDER: S-EPMC7174066 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Short-chain acyl-CoA dehydrogenase deficiency (SCADD) is an autosomal recessive inborn error of mitochondrial fatty acid oxidation. SCADD is biochemically characterized by increased C4-carnitine in plasma and ethylmalonic acid in urine. The diagnosis of SCADD is confirmed by DNA analysis showing SCAD gene mutations and/or variants. SCAD gene variants are present in homozygous form in approximately 6% of the general population and considered to confer susceptibility to development of clinical disease. Clinically, SCADD generally appears to present early in life and to be most frequently associated with developmental delay, hypotonia, epilepsy, behavioral disorders, and hypoglycemia. However, these symptoms often ameliorate and even disappear spontaneously during follow-up and were found to be unrelated to the SCAD genotype. In addition, in some cases, symptoms initially attributed to SCADD could later be explained by other causes. Finally, SCADD relatives of SCADD patients as well as almost all SCADD individuals diagnosed by neonatal screening remained asymptomatic during follow-up. This potential lack of clinical consequences of SCADD has several implications. First, the diagnosis of SCADD should never preclude extension of the diagnostic workup for other potential causes of the observed symptoms. Second, patients and parents should be clearly informed about the potential lack of relevance of the disorder to avoid unfounded anxiety. Furthermore, to date, SCADD is not an optimal candidate for inclusion in newborn screening programs. More studies are needed to fully establish the relevance of SCADD and solve the question as to whether SCADD is involved in a multifactorial disease or represents a nondisease.
| S-EPMC2946545 | biostudies-literature
Project description:Peptides are small biological molecules that are attractive in drug delivery and materials engineering for applications including therapeutics, molecular building blocks and cell-targeting ligands. Peptides are small but can possess complexity and functionality as larger proteins. Due to their intrinsic properties, peptides are able to overcome the physiological and transport barriers presented by diseases. In this review, we discuss the progress of identifying and using peptides to shuttle across biological barriers and facilitate transport of drugs and drug delivery systems for improved therapy. Here, the focus of this review is on rationally designed, phage display peptides, and even endogenous peptides as carriers to penetrate biological barriers, specifically the blood-brain barrier(BBB), the gastrointestinal tract (GI), and the solid tumor microenvironment (T). We will discuss recent advances of peptides as drug carriers in these biological environments. From these findings, challenges and potential opportunities to iterate and improve peptide-based approaches will be discussed to translate their promise towards the clinic to deliver drugs for therapeutic efficacy.
| S-EPMC6023411 | biostudies-literature
Project description:The article demonstrates that computational modeling has the capacity to convert metabolic snapshots, taken sequentially over time, into a description of cellular, dynamic strategies. The specific application is a detailed analysis of a set of actions with which Saccharomyces cerevisiae responds to heat stress. Using time dependent metabolic concentration data, we use a combination of mathematical modeling, reverse engineering, and optimization to infer dynamic changes in enzyme activities within the sphingolipid pathway. The details of the sphingolipid responses to heat stress are important, because they guide some of the longer-term alterations in gene expression, with which the cells adapt to the increased temperature. The analysis indicates that all enzyme activities in the system are affected and that the shapes of the time trends in activities depend on the fatty-acyl CoA chain lengths of the different ceramide species in the system.
| S-EPMC4524633 | biostudies-literature
Project description:A number of amphiphilic difatty acyl linear and cyclic R5K2 peptide conjugates were synthesized by solid-phase peptide methods to enhance the interaction with the hydrophobic cellular phospholipid bilayer and to improve siRNA delivery and silencing. Binding to siRNA molecules was significantly less for the cyclic peptide conjugates. A gradual decrease was observed in the particle size of the complexes with increasing peptide/siRNA ratio for most of the synthesized peptides, suggesting the complex formation. Most of the complexes showed a particle size of less than 200 nm, which is considered an appropriate size for in vitro siRNA delivery. A number of fatty acyl-conjugated peptides, such as LP-C16 and LP-C18, displayed near complete protection against serum degradation. Flow cytometry studies demonstrated significantly higher internalization of fluorescence-labeled siRNA (FAM-siRNA) in the presence of LP-C16, LP-C18, and CP-C16 with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) addition. Confocal microscopy confirmed the cellular internalization of fluorescence-labeled siRNA in the presence of LP-C16 and LP-C18 with DOPE when compared with cells exposed to DOPE/FAM-siRNA. While C16- and C18-conjugated peptides (especially linear peptides) showed silencing against kinesin spindle protein (KSP) and janus kinase 2 (JAK2) proteins, the addition of DOPE enhanced the silencing efficiency significantly for all selected peptides, except for CP-C16. In conclusion, C16 and C18 difatty acyl peptide conjugates were found to enhance siRNA delivery and generate silencing of targeted proteins in the presence of DOPE. This study provides insights for the design and potential application of optimized difatty acyl peptide/lipid nanoparticles for effective siRNA delivery.
| S-EPMC6044792 | biostudies-literature
Project description:The effects of the short-chain ceramides D-erythro-N-acetylsphingosine (C(2)-ceramide), 6-[N-(7-nitrobenz-2-oxa-1, 3-diazole-4-yl)amino]hexanoyl-D-erythro-sphingosine(NBD-ceramide) and N-[4,4-difluoro-5,7-dimethyl-4-bora-3a, 4a-diaza-s-indacene-3-pentanoyl]-D-erythro-sphingosine (DMB-ceramide) on the incorporation of [(14)C]acetate into baby-hamster kidney (BHK) fibroblasts have been examined. C(2)-ceramide at concentrations up to 20 microM caused an inhibition of synthesis of phosphatidylcholine (PtdCho), sphingolipids and cholesterol within 2 h. Similar effects in BHK cells were seen using other radioactive tracers ([(3)H]water, [(3)H]palmitate and [(3)H]choline) and using HL60 cells labelled with [(14)C]acetate. The inhibition of PtdCho synthesis corresponded to an accumulation of label in diacylglycerol and triacylglycerol, probably as a consequence of cytidylyltransferase blockade. With [(3)H]choline label, the decrease in sphingomyelin synthesis could be partly accounted for by accumulation of a slow-moving lipid, likely to be C(2)-sphingomyelin. NBD-ceramide also reduced sphingomyelin and cholesterol biosynthesis, but had much less effect on PtdCho and acylglycerols. In contrast, the only apparent effect of DMB-ceramide was to inhibit synthesis of sphingomyelin, with a reciprocal increase in DMB-sphingomyelin synthesis. However, all of these short-chain ceramides caused massive apoptosis after 18 h, whereas addition of N-acetyldihydrosphingosine or elevation of natural ceramide by treatment of cells with sphingomyelinase had little effect on lipid synthesis or apoptosis. The present findings suggest that the apoptotic effect of short-chain ceramides is sometimes associated with inhibition of cytidylyltransferase, but is more closely correlated with a competitive inhibition of normal sphingomyelin biosynthesis.
| S-EPMC1220795 | biostudies-other
Project description:BackgroundShort-chain acyl-CoA dehydrogenase deficiency (SCADD) is a rare inherited mitochondrial fatty acid oxidation disorder associated with variations in the ACADS (Acyl-CoA dehydrogenase, C-2 to C-3 short chain) gene. SCADD has highly variable biochemical, genetic and clinical characteristics. Phenotypes vary from fatal metabolic decompensation to asymptomatic individuals.Subject and methodsA Romani boy presented at 3 days after birth with hypoglycaemia, hypotonia and respiratory pauses with brief generalized seizures. Afterwards the failure to thrive and developmental delay were present. Organic acids analysis with gas chromatography-mass spectrometry (GS/MS) in urine and acylcarnitines analysis with liquid chromatography-tandem mass spectrometry (LC-MS/MS) in dried blood spot were measured. Deoxyribonucleic acid (DNA) was isolated from blood and polymerase chain reactions (PCRs) were performed for all exons. Sequence analysis of all exons and flanking intron sequences of ACADS gene was performed.ResultsOrganic acids analysis revealed increased concentration of ethylmalonic acid. Acylcarnitines analysis showed increase of butyrylcarnitine, C4-carnitine. C4-carnitine was 3.5 times above the reference range (<0.68 µmol/L). Confirmation analysis for organic acids and acylcarnitine profile was performed on the second independent sample and showed the same pattern of increased metabolites. Sequence analysis revealed 3-bp deletion at position 310-312 in homozygous state (c.310_312delGAG). Mutation was previously described as pathogenic in heterozygous state, while it is in homozygous state in our patient.ConclusionsIn our case clinical features of a patient, biochemical parameters and genetic data were consistent and showed definitely SCAD deficiency.
| S-EPMC4470102 | biostudies-literature
Project description:In this work, a peptide for ocular delivery (POD) and human immunodeficiency virus transactivator were conjugated with biodegradable poly(lactic-co-glycolic acid) (PGLA)-polyethylene glycol (PEG)-nanoparticles (NPs) in an attempt to improve ocular drug bioavailability. The NPs were prepared by the solvent displacement method following two different pathways. One involved preparation of PLGA NPs followed by PEG and peptide conjugation (PLGA-NPs-PEG-peptide); the other involved self-assembly of PLGA-PEG and the PLGA-PEG-peptide copolymer followed by NP formulation. The conjugation of the PEG and the peptide was confirmed by a colorimetric test and proton nuclear magnetic resonance spectroscopy. Flurbiprofen was used as an example of an anti-inflammatory drug. The physicochemical properties of the resulting NPs (morphology, in vitro release, cell viability, and ocular tolerance) were studied. In vivo anti-inflammatory efficacy was assessed in rabbit eyes after topical instillation of sodium arachidonate. Of the formulations developed, the PLGA-PEG-POD NPs were the smaller particles and exhibited greater entrapment efficiency and more sustained release. The positive charge on the surface of these NPs, due to the conjugation with the positively charged peptide, facilitated penetration into the corneal epithelium, resulting in more effective prevention of ocular inflammation. The in vitro toxicity of the NPs developed was very low; no ocular irritation in vitro (hen's egg test-chorioallantoic membrane assay) or in vivo (Draize test) was detected. Taken together, these data demonstrate that PLGA-PEG-POD NPs are promising vehicles for ocular drug delivery.
| S-EPMC4315550 | biostudies-literature
Project description:Lipid phase heterogeneity in plasma membranes is thought to play a key role in targeting cellular signaling, but efforts to test lipid raft and related hypotheses are limited by the spatially dynamic nature of these phase-based structures in cells and by experimental characterization tools. We suggest that perturbation of plasma membrane structure by lipid derivatives offers a general method for assessing functional roles for ordered lipid regions in membrane and cell biology. We previously reported that short chain ceramides with either C2 or C6 acyl chains inhibit antigen-stimulated Ca2+ mobilization (Gidwani et al., 2003). We now show that these short chain ceramides inhibit liquid order (Lo)-liquid disorder (Ld) phase separation in giant plasma membrane vesicles that normally occurs at low temperatures. Furthermore, they are effective inhibitors of tyrosine phosphorylation stimulated by antigen, as well as store-operated Ca2+ entry. In Jurkat T cells, C6-ceramide is also effective at inhibiting Ca2+ mobilization stimulated by either anti-TCR or thapsigargin, consistent with the view that these short chain ceramides effectively interfere with functional responses that depend on ordered lipid regions in the plasma membrane.
| S-EPMC6176950 | biostudies-literature
Project description:Natural extracellular vesicles (EVs) are ideal drug carriers due to their remarkable biocompatibility. Their delivery specificity can be achieved by the conjugation of targeting ligands. However, existing methods to engineer target-specific EVs are tedious or inefficient, having to compromise between harsh chemical treatments and transient interactions. Here, we describe a novel method for the covalent conjugation of EVs with high copy numbers of targeting moieties using protein ligases. Conjugation of EVs with either an epidermal growth factor receptor (EGFR)-targeting peptide or anti-EGFR nanobody facilitates their accumulation in EGFR-positive cancer cells, both in vitro and in vivo. Systemic delivery of paclitaxel by EGFR-targeting EVs at a low dose significantly increases drug efficacy in a xenografted mouse model of EGFR-positive lung cancer. The method is also applicable to the conjugation of EVs with peptides and nanobodies targeting other receptors, such as HER2 and SIRP alpha, and the conjugated EVs can deliver RNA in addition to small molecules, supporting the versatile application of EVs in cancer therapies. This simple, yet efficient and versatile method for the stable surface modification of EVs bypasses the need for genetic and chemical modifications, thus facilitating safe and specific delivery of therapeutic payloads to target cells.
| S-EPMC7886705 | biostudies-literature
Project description:ObjectiveAcyl-CoA synthetase short-chain family member 2 (ACSS2) activity provides a major source of acetyl-CoA to drive histone acetylation. This study aimed to unravel the ACSS2 expression during mouse spermatogenesis, where a dynamic and stage-specific genome-wide histone hyperacetylation occurs before histone eviction.Materials and methodsIn this experimental study, ACSS2 expression levels during spermatogenesis were verified by Immunodetection. Testis paraffin-embedded sections were used for IHC staining with anti-H4 pan ac and anti-ACSS2. Co-detection of ACSS2 and H4K5ac was performed on testis tubular sections by immunofluorescence. Proteins extracts from fractionated male germ cells were subjected to western-blotting and immunoblot was probed with anti- ACSS2 and anti-actin.ResultsThe resulting data showed that the commitment of progenitor cells into meiotic divisions leads to a robust accumulation of ACSS2 in the cell nucleus, especially in pachytene spermatocytes (P). However, ACSS2 protein drastically declines during post-meiotic stages, when a genome-wide histone hyperacetylation is known to occur.ConclusionThe results of this study are in agreement with the idea that the major function of ACSS2 is to recycle acetate generated after histone deacetylation to regenerate acetyl-CoA which is required to maintain the steady state of histone acetylation. Thus, it is suggested that in spermatogenic cells, nuclear activity of ACSS2 maintains the acetate recycling until histone hyperacetylation, but disappears before the acetylation-dependent histone degradation.
| S-EPMC6791068 | biostudies-literature