The blood-brain barrier (BBB) serves as a highly intricate and dynamic interface connecting the brain and the bloodstream, playing a vital role in maintaining brain homeostasis. BBB dysfunction has been associated with multiple neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS); however, the role of the BBB in neurodegeneration is understudied. We developed an ALS patient-derived model of the BBB by using cells derived from 5 patient donors carrying C9ORF72 mutations.
View Article and Find Full Text PDFAmyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease involving selective vulnerability of energy-intensive motor neurons (MNs). It has been unclear whether mitochondrial function is an upstream driver or a downstream modifier of neurotoxicity. We separated upstream genetic determinants of mitochondrial function, including genetic variation within the mitochondrial genome or autosomes; from downstream changeable factors including mitochondrial DNA copy number (mtCN).
View Article and Find Full Text PDFDisruption to protein homeostasis caused by lysosomal dysfunction and associated impairment of autophagy is a prominent pathology in amyotrophic lateral sclerosis and frontotemporal dementia (ALS/FTD). The most common genetic cause of ALS/FTD is a G4C2 hexanucleotide repeat expansion in (C9ALS/FTD). Repeat-associated non-AUG (RAN) translation of G4C2 repeat transcripts gives rise to dipeptide repeat (DPR) proteins that have been shown to be toxic and may contribute to disease etiology.
View Article and Find Full Text PDFDipeptide repeat (DPR) proteins are aggregation-prone polypeptides encoded by the pathogenic GGGGCC repeat expansion in the gene, the most common genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia. In this study, we focus on the role of poly-GA DPRs in disease spread. We demonstrate that recombinant poly-GA oligomers can directly convert into solid-like aggregates and form characteristic β-sheet fibrils in vitro.
View Article and Find Full Text PDFAstrocytes are highly specialised cells, responsible for CNS homeostasis and neuronal activity. Lack of human in vitro systems able to recapitulate the functional changes affecting astrocytes during ageing represents a major limitation to studying mechanisms and potential therapies aiming to preserve neuronal health. Here, we show that induced astrocytes from fibroblasts donors in their childhood or adulthood display age-related transcriptional differences and functionally diverge in a spectrum of age-associated features, such as altered nuclear compartmentalisation, nucleocytoplasmic shuttling properties, oxidative stress response and DNA damage response.
View Article and Find Full Text PDFN-terminal extensions ("tags") have proven valuable for producing peptides using high throughput recombinant expression technologies. However, the applicability is hampered by the limited options for specific and efficient proteases to release the fully native sequence without additional amino acids in the N-terminal. Here we describe the Escherichia coli (E.
View Article and Find Full Text PDFIt is important to understand how the disease process affects the metabolic pathways in amyotrophic lateral sclerosis and whether these pathways can be manipulated to ameliorate disease progression. To analyse the basis of the metabolic defect in amyotrophic lateral sclerosis we used a phenotypic metabolic profiling approach. Using fibroblasts and reprogrammed induced astrocytes from C9orf72 and sporadic amyotrophic lateral sclerosis cases we measured the production rate of reduced nicotinamide adenine dinucleotides (NADH) from 91 potential energy substrates simultaneously.
View Article and Find Full Text PDFObjective: To characterize the EndoC-βH1 cell line as a model for human beta cells and evaluate its beta cell functionality, focusing on insulin secretion, proliferation, apoptosis and ER stress, with the objective to assess its potential as a screening platform for identification of novel anti-diabetic drug candidates.
Methods: EndoC-βH1 was transplanted into mice for validation of in vivo functionality. Insulin secretion was evaluated in cells cultured as monolayer and as pseudoislets, as well as in diabetic mice.
Calcitonin is a peptide hormone consisting of 32 amino acid residues and the calcitonin receptor is a Class B G protein-coupled receptor (GPCR). The crystal structure of the human calcitonin receptor ectodomain (CTR ECD) in complex with a truncated analogue of salmon calcitonin ([BrPhe(22)]sCT(8-32)) has been determined to 2.1-Å resolution.
View Article and Find Full Text PDFPeptides are of increasing interest as therapeutics in a wide range of diseases, including metabolic diseases such as diabetes and obesity. In the latter, peptide hormones such as peptide YY (PYY) and pancreatic peptide (PP) are important templates for drug design. Characteristic for these peptides is that they contain a C-terminal that is α-amidated, and this amidation is crucial for biological function.
View Article and Find Full Text PDFD-Alanine is a central component of the cell wall in most prokaryotes. D-Alanine synthesis in Escherichia coli is carried out by two different alanine racemases encoded by the alr and dadX genes. Deletion of alr and dadX from the E.
View Article and Find Full Text PDFBackbone cyclic insulin was designed and prepared by reverse proteolysis in partial organic solvent of a single-chain precursor expressed in yeast. The precursor contains two loops to bridge the two chains of native insulin. The cyclisation method uses Achromobacter lyticus protease and should be generally applicable to proteins with C-terminal lysine and proximal N-terminal.
View Article and Find Full Text PDFPEGylation modification has been used to improve the pharmacokinetic properties of protein-based drugs. For example, PEGylated human growth hormone (hGH) has been shown to exhibit better pharmacokinetic profiles than the unmodified hGH. Unlike chemical PEGylation of hGH that is difficult to be controlled to result in homogeneity, microbial transglutaminase (mTGase) only conjugates poly(ethelene glycol) (PEG) on glutamine-40 (Q40) and glutamine-141 (Q141) of hGH, the only glutamine residues exposed.
View Article and Find Full Text PDFFEMS Immunol Med Microbiol
March 2009
The protein composition and N-terminal sequences of proteins in the outer membrane of Chlamydia trachomatis L2 were analysed following isolation of N-terminal peptides using combined fractional diagonal chromatography and identification by liquid chromatography tandem MS. Acetylation of primary amino groups of in vivo generated proteolytic cleavage sites facilitated identification of such sites in known outer membrane proteins (MOMPs). Our results further support a proposed prediction of the topology of the MOMPs.
View Article and Find Full Text PDFBiochem Biophys Res Commun
November 2008
In this publication we describe a peptide insulin receptor antagonist, S661, which is a single chain peptide of 43 amino acids. The affinity of S661 for the insulin receptor is comparable to that of insulin and the selectivity for the insulin receptor versus the IGF-1 receptor is higher than that of insulin itself. S661 is also an antagonist of the insulin receptor of other species such as pig and rat, and it also has considerable affinity for hybrid insulin/IGF-1 receptors.
View Article and Find Full Text PDFInsulin receptor (IR) and insulin-like growth factor I receptor (IGF-IR) are both from the same subgroup of receptor tyrosine kinases that exist as covalently bound receptor dimers at the cell surface. For both IR and IGF-IR, the most described forms are homodimer receptors. However, hybrid receptors consisting of one-half IR and one-half IGF-IR are also present at the cell surface.
View Article and Find Full Text PDFBreast cancer is a leading cause of death for women. The underlying molecular mechanism is still not well understood. In this study, two-dimensional gel electrophoresis combined with mass spectrometry was used to analyze changes in the proteome of infiltrating ductal carcinoma compared to normal breast tissue.
View Article and Find Full Text PDFThe genome of the obligate intracellular bacterium Chlamydia trachomatis comprises 894 genes predicted by computer-based analysis. As part of a large-scale proteome analysis of C. trachomatis, a small abundant protein encoded by a previously unrecognized novel 204-bp open reading frame was identified by tandem mass spectrometry.
View Article and Find Full Text PDFChlamydiae are obligate intracellular bacteria that are important human pathogens. The Chlamydia genomes contain orthologues to secretion apparatus proteins from other intracellular bacteria, but only a few secreted proteins have been identified. Most likely, effector proteins are secreted in order to promote infection.
View Article and Find Full Text PDFChlamydia trachomatis represents a group of human pathogenic obligate intracellular and gram-negative bacteria. The genome of C. trachomatis D comprises 894 open reading frames (ORFs).
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