Changes In Protein Composition Research Articles

ИЗМЕНЕНИЕ АМИНОКИСЛОТНОГО СОСТАВА БЕЛКА ЗЕРНОВЫХ ТЕКСТУРАТОВ И МУКИ ПРИ ХРАНЕНИИ РАЗЛИЧНЫМИ СПОСОБАМИ

The aim of the study is to investigate changes in the amino acid composition of grain textured flour proteins during storage using different methods. The object of the study was textured flours obtained from barley and oat grain extrudates, barley and oat flour. The experimental samples were stored using different types of packaging with different barrier properties. Samples stored in bulk were selected for analysis directly at the enterprise. The amino acid composition was determined using a verified capillary electrophoresis system at the Research and Testing Center of the Krasnoyarsk State Agrarian University. The limiting amino acids in general for most storage periods and methods were: for oat flour – tryptophan, leucine + isoleucine, for barley flour – lysine, leucine + isoleucine; for textured flours from grain crop extrudates – lysine, tryptophan, leucine + isoleucine. The calculated index of essential amino acids (INA) had a value greater than 1, but did not characterize the protein of flour and texturate from grain extrudate as ideal, acquiring such a value due to the larger proportion of excess amino acids. The protein of oat grain extrudate texturate was less complete compared to the protein of the corresponding type of flour with storage periods of 1 and 12 months. The determined total content of calculated amino acids with the storage option in opaque and transparent polymeric material with an air environment inside the package was higher compared to other options. This allows us to consider these types of packaging as the most optimal of all those considered for storage.

Changes in protein content, composition and dough quality: outcomes of Australian wheat breeding on varieties released from 1860 to 2015

Changes in protein content, composition and dough quality: outcomes of Australian wheat breeding on varieties released from 1860 to 2015

Abstract 4138633: Infusion of human apolipoprotein A-I (CSL112) promotes several aspects of reverse cholesterol transport

Background: High-density lipoprotein (HDL)-cholesterol is inversely correlated with cardiovascular risk, but increasing its circulating concentration is insufficient to prevent adverse cardiovascular outcomes. Instead, the emerging paradigm is on increasing the function of HDL and its major protein constituent apolipoprotein A-I (apoA-I), to increase reverse cholesterol transport. Objective: To investigate the effect of apoA-I [human] (CSL112) infusion on HDL protein composition, and provide further insights into the mechanism of action of CSL112 administered post-acute myocardial infarction (AMI). Methods: A mass spectrometry (MS)-based proteomic approach was used to evaluate changes in HDL protein composition in patients (n=50) from the AEGIS-I (ApoA-I Event Reducing in Ischemic Syndromes I) study who received either placebo or CSL112 post AMI. HDL was immuno-isolated from patient plasma using anti-apoA-I antibodies. Cholesterol esterification rate (CER) was measured to determine lecithin-cholesterol acyl transferase (LCAT) activity. Cholesterol efflux capacity (CEC) and hepatocyte uptake were assessed using patient serum in ex vivo cell-based assays. Results: CSL112 induced extensive rearrangement of HDL proteins at 4 hours post-infusion. Levels of apolipoproteins A2, B, C, and E as well as the acute phase proteins serum amyloid A1 and A4 were significantly reduced. By contrast, apoA-I, apoM, and LCAT significantly increased. Elevated apoA-I and LCAT levels on HDL were associated with an increase in CEC, plasma HDL-C levels, and CER in CSL112-treated patients. Furthermore, enhanced CEC strongly correlated with cholesterol uptake by hepatic cells (r=0.95 p<0.001). Conclusion: CSL112 altered HDL composition and increased HDL functionality by promoting multiple steps of the reverse cholesterol transport pathway.

Total protein concentration and stability of Amb a 1 in glycerinated ragweed sublingual immunotherapy stored at room temperature and refrigerated cold temperature.

Few studies have investigated optimal storage conditions or expiration dates for sublingual immunotherapy (SLIT) formulations prepared from glycerinated allergen extracts. The objective of this study was to compare concentrations of short ragweed major allergen (Amb a 1) and total protein in SLIT formulations stored at two different temperatures. It was hypothesised that protein concentrations would show greater decline over time in a formulation stored at room temperature (RT) than in one stored under refrigeration. Two SLIT samples containing equal volumes of 20,000 PNU Amb a 1 extract were prepared and stored at refrigerated cold (CT) (2-8°C) or RT (20-24°C) for 140 days. Changes in total protein and major allergen concentration and composition were measured by Bradford assay, two-site enzyme-linked immunosorbent assay and SDS-PAGE. Presence of Amb a 1 was confirmed with Western immunoblot. Data were analysed using an analysis of covariance, with p < 0.05 considered significant. SDS-PAGE showed compositional changes in a ~26-30 kDa protein band under RT and not CT storage. The Amb a 1 concentration of the RT SLIT sample declined significantly over time, compared to that of the CT SLIT sample (F(1,8) = 47.69, p < 0.0001). There was no significant difference in total protein concentration over time between groups (F(1,8) = 1.79, p = 0.22). These results demonstrate that storage of glycerinated SLIT formulations in refrigerated CT preserved the highest concentration of the specific allergen Amb a 1, suggesting that SLIT formulations containing short ragweed should be stored under refrigeration.

Prone to loss: Senescence-regulated protein degradation leads to lower protein extractability in aging tomato leaves

The utilization of proteins extracted from tomato (Solanum lycopersicum) leaves as cost-effective resources for human consumption or animal feed has gained interest. Thus, increasing protein extractability from tomato leaves became a new breeding target. However, the genetic factors influencing this trait remains poorly understood. In this study, we analyzed changes in leaf protein content, protein composition, and extraction yield across developmental stages, which are vegetative growth, flowering, fruit-forming, and mature fruit. Moreover, tomato gene expression across developmental stages was also studied, to identify genes underlying variability in leaf protein extraction. Protein extraction yield decreased from 0.51 g/g to 0.01 g/g leaf protein from the vegetative to mature stage. However, total protein content inferred with Dumas combustion analysis did not change over the developmental stages tested, while the protein-to-peptide ratio decreased significantly. To further analyze potential causes underlying the decline of protein-to-peptide ratio, the enzymatic activity of proteases – i.e. the enzymes responsible for protein degradation – and the expression of genes encoding these enzymes was studied along plant development. The overall specific activity of proteases did not change significantly throughout plant development. On the contrary, the gene expression of distinct members of the aspartic, cysteine, and subtilase protease families increased. Overall, our findings suggest that extraplastidic protein degradation likely underlies the protein degradation observed during senescence. In the future, the reduction of the activity of extraplastidic proteases through biotechnology could represent an effective strategy to develop tomato varieties with improved protein extraction yields.

Changes of gluten protein composition during sourdough fermentation in rye flour

AbstractBackground and ObjectivesCeliac disease (CD) is an immune‐mediated condition triggered by gluten consumption. Although more studies stated that gluten proteins are partially degrading during sourdough fermentation, it is still unclear whether the CD toxic epitopes are affected. Our aim was to examine the effect of controlled sourdough fermentation on the gluten content and composition with different sourdough starters in rye flour.FindingsDespite significant changes in protein size distribution and a decrease in secalin types confirmed by high‐performance liquid chromatography methods, the enzyme‐linked immunosorbent assay results showed increased gluten content after fermentation. The incomplete degradation of gluten and the potential resistance of celiac toxic epitopes may explain our results. As part of the R5 antibody binding, epitopes are supposed to be unavailable in the native form of secalins; they might be released and become accessible in the smaller protein fragments.ConclusionsIn comparison of the effect of different starter cultures, the results show that the different microbiological composition of the sourdough samples might be the reason for the differences in the protein degradation.Significance and NoveltyResults highlight the importance of a deeper investigation of the effects of gluten protein degradation on CD toxicity and the standardization of the fermentation process.

Proteomic analysis revealed the deterioration of surimi gelling capability to fish stress during transportation

Live silver carp with various transportation durations (3 h, 6 h, 12 h and 24 h) was processed into surimi. Proteomics and other technical methods were applied to investigate the changes in protein composition and structure aiming to explore the mechanism through which transportation stress affects gelling capability of surimi. As the transportation time was prolonged from 3 to 24 h, the gel strength of surimi gel decreased by 28.97 %, and the whiteness value decreased significantly (p < 0.05). Moreover, malondialdehyde content in fish serum and surface hydrophobicity of surimi also increased significantly (p < 0.05), suggesting that oxidation induced protein unfolding. Proteomic analysis identified eleven significantly differential proteins in the samples after 24 h of transportation compared to those transported for 3 h. Notably, the expression levels of myosin heavy chain and glutathione peroxidase were significantly down-regulated. Additionally, the PI3K-Akt signaling pathway was activated. Prolonged transportation time resulted in a looser microstructure of surimi gels, increased free water content and uneven water distribution. These results indicated that the altered properties of surimi gel due to transportation stress are primarily related to oxidative stress which leads to oxidative denaturation of proteins and the degradation of myosin.

The Effect of Tillage Systems and Weed Control Methods on Grain Yield and Gluten Protein Compositional and Content-Related Changes in Hybrid Bread Wheat

The use of simplified tillage systems and weed control methods using reduced herbicide doses in wheat production technology is one of the basic requirements of sustainable agriculture in terms of obtaining high-quality grain of this species. The aim of three-year field studies was to determine the yield and quality characteristics of hybrid wheat grain depending on two tillage systems (CT and RT) and four weed control methods: mechanical (M) and mechanical–chemical, using recommended herbicide doses (MH100) and doses reduced by 25 and 50% (MH75, MH50). A comparable grain yield, number of grains per spike, weight of one thousand wheat grains, and amount of gluten and ω gliadin subunits (GLI) were obtained in the RT and CT systems. The CT system increased protein content (by 15.2 g kg−1) and the increase in the sum of gluten protein fractions was higher for glutenins (GLU) and their LMW and HMW subunits (from 20.9 to 29.8%). The application of the method with the recommended herbicide dose (MH100), compared to M and MH50, resulted in an increase in grain yield by 0.89 and 1.04 t ha−1, respectively, as well as in the sum of GLI (by 8.4 and 12.3%) and GLU (by 13.7 and 25.3%). The application of the herbicide dose reduced by 25% (MH75) compared to the recommended dose (MH100), especially in the RT system, did not cause a significant decrease in protein content and the amount of GLI and GLU, while reducing grain yield (by 0.26 t ha−1) and the amount of gluten (by 3.1%).

Alterations in plasma proteome during acute COVID-19 and recovery

BackgroundThe severe course of COVID-19 causes cardiovascular injuries, although the mechanisms involved are still not fully recognized, linked, and understood. Their characterization is of great importance with the establishment of the conception of post-acute sequelae of COVID-19, referred to as long COVID, where blood clotting and endothelial abnormalities are believed to be the key pathomechanisms driving circulatory system impairment.MethodsThe presented study investigates temporal changes in plasma proteins in COVID-19 patients during hospitalization due to SARS-CoV-2 infection and six months after recovery by targeted SureQuant acquisition using PQ500 panel.ResultsIn total, we identified 167 proteins that were differentially regulated between follow-up and hospitalization, which functionally aggregated into immune system activation, complement and coagulation cascades, interleukins signalling, platelet activation, and extracellular matrix organization. Furthermore, we found that temporal quantitative changes in acute phase proteins correlate with selected clinical characteristics of COVID-19 patients.ConclusionsIn-depth targeted proteome investigation evidenced substantial changes in plasma protein composition of patients during and recovering from COVID-19, evidencing a wide range of functional pathways induced by SARS-CoV-2 infection. In addition, we show that a subset of acute phase proteins, clotting cascade regulators and lipoproteins could have clinical value as potential predictors of long-term cardiovascular events in COVID-19 convalescents.

MTORC1 Signaling Inhibition Modulates Mitochondrial Function in Frataxin Deficiency.

Lysosomes regulate mitochondrial function through multiple mechanisms including the master regulator, mechanistic Target of Rapamycin Complex 1 (mTORC1) protein kinase, which is activated at the lysosomal membrane by nutrient, growth factor and energy signals. mTORC1 promotes mitochondrial protein composition changes, respiratory capacity, and dynamics, though the full range of mitochondrial-regulating functions of this protein kinase remain undetermined. We find that acute chemical modulation of mTORC1 signaling decreased mitochondrial oxygen consumption, increased mitochondrial membrane potential and reduced susceptibility to stress-induced mitophagy. In cellular models of Friedreich's Ataxia (FA), where loss of the Frataxin (FXN) protein suppresses Fe-S cluster synthesis and mitochondrial respiration, the changes induced by mTORC1 inhibitors lead to improved cell survival. Proteomic-based profiling uncover compositional changes that could underlie mTORC1-dependent modulation of FXN-deficient mitochondria. These studies highlight mTORC1 signaling as a regulator of mitochondrial composition and function, prompting further evaluation of this pathway in the context of mitochondrial disease.

Effects of nitrogen starvation on growth and biochemical composition of some microalgae species.

Nitrogen is one of the most important nutrient sources for the growth of microalgae. We studied the effects of nitrogen starvation on the growth responses, biochemical composition, and fatty acid profile of Dunaliella tertiolecta, Phaeodactylum tricornutum, and Nannochloropsis oculata. The lack of nitrogen caused changes in carbohydrate, protein, lipid, and fatty acid composition in all examined microalgae. The carbohydrate content increased 59% in D. tertiolecta, while the lipid level increased 139% in P. tricornutum under nitrogen stress conditions compared to the control groups. Nitrogen starvation increased the oligosaccharide and polysaccharide contents of D. tertiolecta 4.1-fold and 3.6-fold, respectively. Furthermore, triacylglycerol (TAG) levels in N. oculata and P. tricornutum increased 2.3-fold and 7.4-fold, respectively. The dramatic increase in the amount of TAG is important for the use of these microalgae as raw materials in biodiesel. Nitrogen starvation increased the amounts of oligosaccharides and polysaccharides of D. tertiolecta, while increased eicosapentaenoic acid (EPA) in N. oculata and docosahexaenoic acid (DHA) content in P. tricornutum. The amount of polyunsaturated fatty acids (PUFAs), EPA, DHA, oligosaccharides, and polysaccharides in microalgal species can be increased without using the too costly nitrogen source in the culture conditions, which can reduce the most costly of living feeding.

Relationship between amide ratio assessed by Fourier-transform infrared spectroscopy: A biomarker candidate for polycythemia vera disease.

The study utilized Fourier transform infrared (FTIR) spectroscopy coupled with chemometrics to investigate protein composition and structural changes in the blood serum of patients with polycythemia vera (PV). Principal component analysis (PCA) revealed distinct biochemical properties, highlighting elevated absorbance of phospholipids, amides, and lipids in PV patients compared to healthy controls. Ratios of amide I/amide II and amide I/amide III indicated alterations in protein structures. Support vector machine analysis and receiver operating characteristic curves identified amide I as a crucial predictor of PV, achieving 100% accuracy, sensitivity, and specificity, while amide III showed a lower predictive value (70%). PCA analysis demonstrated effective differentiation between PV patients and controls, with key wavenumbers including amide II, amide I, and CH lipid vibrations. These findings underscore the potential of FTIR spectroscopy for diagnosing and monitoring PV.

Coronin 2B deficiency induces nucleolar stress and neuronal apoptosis

In eukaryotes, the nucleolus is the critical non-membranous organelle within nuclei that is responsible for ribosomal DNA (rDNA) transcription and ribosome biogenesis. The transcription of rDNA, a rate-limiting step for ribosome biogenesis, is tightly regulated to meet the demand for global protein synthesis in response to cell physiology, especially in neurons, which undergo rapid changes in morphology and protein composition during development and synaptic plasticity. However, it is unknown how the pre-initiation complex for rDNA transcription is efficiently assembled within the nucleolus in neurons. Here, we report that the nucleolar protein, coronin 2B, regulates rDNA transcription and maintains nucleolar function through direct interaction with upstream binding factor (UBF), an activator of RNA polymerase I transcriptional machinery. We show that coronin 2B knockdown impairs the formation of the transcription initiation complex, inhibits rDNA transcription, destroys nucleolar integrity, and ultimately induces nucleolar stress. In turn, coronin 2B-mediated nucleolar stress leads to p53 stabilization and activation, eventually resulting in neuronal apoptosis. Thus, we identified that coronin 2B coordinates with UBF to regulate rDNA transcription and maintain proper nucleolar function in neurons.

Gluten-free crackers using chickpea and pumpkin seed press cake blend: Effects of gastrointestinal digestion

The use of a blend of chickpea and pumpkin seed press cake flours in the production of gluten-free crackers represents a promising strategy to address nutritional gaps and meet the growing demand for healthier gluten-free options. To test this assumption, an in vitro digestion method was employed to assess changes in total phenolic content, antioxidant activity, protein composition, electrophoretic patterns, and mineral content of gluten-free crackers formulated using these raw materials before and after digestion. The crackers were produced substituting 20% and 35% of chickpea flour by using two types of pumpkin seed press cake flour, one from virgin oil pressing (VFC) and the other from cold-pressed oil pressing (CFC). This approach aimed to assess how the treatment history of the pumpkin seed press cake flour affected the tested parameters. All samples displayed a 3- to 4-fold increase in total phenolic content after in vitro digestion. A noticeable enhancement in antioxidant activity is observed, where CFC samples showed higher values compared to VFC samples. The control sample and 35CFC sample present similar protein digestibility values (%), 76.97 and 77.05 respectively, while other crackers showed significantly lower digestibility. Incorporation of pumpkin seed press cake flours leads to a substantial increase in mineral content, notably zinc (up to 2-fold), iron (up to 40%), and magnesium (up to 2.5 fold). Overall, the study provides valuable insights into the utilization of pumpkin seed press cake as a potential source of bioactive compounds, emphasizing its significance beyond its traditional role as a by-product.

ASSOCIATION ORAL CORTICOSTEROIDS AND LONG-TERM RISK OF CATARACT: A SYSTEMATIC REVIEW AND META-ANALYSIS STUDY

Background: Cataracts are a significant health concern, particularly in aging populations, impacting vision, mental well-being, and overall quality of life. Corticosteroid use has been linked to cataract development. This study aims to explore the relationship between oral corticosteroid (OCS) exposure and the long-term risk of cataract. Method: Following PRISMA guidelines, a systematic review and meta-analysis were conducted to investigate this association. Relevant studies were identified through comprehensive searches across multiple databases. Data included cataract incidence/prevalence and OCS therapy. Results: A total of 1,270 articles were retrieved from online databases (PubMed, SagePub, SpringerLink and Google Scholar). After three rounds of screening, five articles directly relevant to the systematic review were selected for full-text reading and analysis. These five studies collectively involved 27,250 cases of cataract following oral corticosteroid (OCS) exposure, while 47,267 controls did not develop cataracts. No statistically significant association is found between OCS and cataract formation (OR 0.117, CI 95 0.0085 to 1.6021, p0.11). Conclusion: Cataracts in oral corticosteroid (OCS) users result from abnormal lens cell movement and protein composition changes due to protein adduct formation. Increased OCS dosage and frequency correlate with higher cataract risk. However, evidence quality was deemed low to moderate, highlighting the need for well-designed RCTs to minimize bias and heterogeneity.

Polymorphism of spore germination receptor genes in Bacillus anthracis strains of major genetic lineages

Introduction. The genetic structure of the global population of Bacillus anthracis characterized by an unequal distribution of isolates of the main genetic lineages A, B and C, the reason for which is unknown. Determining the characteristics of genes encoding factors that determine the existence of this pathogen at the intra- and extra organismal stages of the life cycle, which can influence the prevalence of strains, is relevant. Aim — сharacterization of the genes and proteins of spore germination in strains of the anthrax pathogen of different genetic lineages. Materials and methods. Whole genome sequences of 46 B. anthracis strains and the CI strain of B. cereus biovar anthracis from the NCBI GenBank database studied. In silico analysis carried out using the programs “BLASTn”, “MEGA X”, “Tandem Repeat Finder”. Results. The number of SNPs, indels and pseudogenes in B. anthracis strains of line B was 2,7–25,6 times higher, in line C 2–23,5 times, and in the B. cereus biovar anthracis strain was 20–2841 times higher than in strains of line A. Significant substitutions in genes leading to changes in the amino acid composition of 10 germination receptor proteins were also significantly more common in B. anthracis strains of lines B, C and the B. cereus biovar anthracis strain. Undescribed VNTRs within the gerHA gene with repeat units of 78 and 117 bp identified, varying between and within isolates of different genetic lineages. Six germination receptor genes have been shown to have rare starting codons. Conclusion. A larger number of non-synonymous SNPs in the genes of spore germination receptors with changes in the amino acid composition of proteins in B. anthracis strains of the main genetic lines B, C and B. cereus biovar anthracis than in strains of line A suggests their limited adaptive capabilities and may be one of the explanations for the lower prevalence compared to line A. Differences in the gerHA and gerM genes make it possible to differentiate the major B and C genetic lineages from A.

Abstract 3040: Quantitative Proteomic Analysis Of HDL Shows Apolipoprotein M (ApoM) As A Possible Marker For COVID-19 Mortality

Introduction: High-density lipoprotein (HDL) comprises a heterogeneous group of particles that differ in many aspects, such as density, size, composition and function. The use of mass spectrometry-based proteomics to investigate HDL protein composition has brought some new insights into the field. The qualitative and quantitative HDL proteome is remodeled in different disease states, such as diabetes mellitus, hypercholesterolemia and kidney dysfunction. Beyond its established role in inflammatory and cardiovascular diseases, HDL's involvement in infectious diseases, such as COVID-19, has recently come to light. Here, we investigate the remodeling of HDL proteome in hospitalized and non-hospitalized COVID-19 patients. Hypothesis: We hypothesize HDL proteome is remodeled in infectious diseases and may be a marker and perhaps a predictor of a poor prognosis. Methods: We implemented a robust, global label-free quantification proteomic approach to unravel relative changes in HDL protein composition. We analyzed the proteome of COVID-19 subjects from Brazil categorized in two groups, hospitalized (n=30) and non-hospitalized (n=11). Results: Comparative analysis between hospitalized and non-hospitalized patients revealed a more than 50% increase in relative levels of certain proteins in hospitalized patients, including the inflammatory proteins serum amyloid A1 and A2, as well as pulmonary surfactant-associated protein B. We also observed reductions in the lipid-metabolism related apolipoprotein A2 and phospholipid transfer protein. These findings, independent of sex, triglyceride and HDL-cholesterol, suggest an inflammatory remodeling of the HDL particles. Further analysis of surviving (n=35) and deceased patients (n=6) indicated a negative association between ApoM levels and odds of death due to COVID-19 complications (odds ratio per 1-SD increase in ApoM was 0.27 [0.07 to 0.72], P=0.007). Conclusions: Our results point out HDL remodeling is a marker of COVID-19 severity and ApoM-carried sphingosine-1-phosphate signaling pathway may play a pivotal role in the disease outcome.

Effects of aging and exercise on Mitochondria-ER contacts (MERCs) in skeletal muscle

Mitochondrial dysfunction is a prominent factor contributing to age-associated loss of muscle mass and force (a.k.a., sarcopenia). Yet, events preceding age-related mitochondrial dysfunction, which may allow the development of new therapies, remain poorly understood. Physical coupling of the outer mitochondrial membrane (OMM) to the endoplasmic or sarcoplasmic reticulum (ER), termed mitochondria ER contact sites (MERCs), modulate several mitochondrial processes influencing cellular function. In an energetically demanding and primarily post-mitotic tissue, we hypothesized that alterations in MERCs correlate with the development of sarcopenia. We also hypothesized that MERCs respond to exercise training and may contribute to beneficial muscular remodeling in older adults. To address these, we studied three age groups of male C57BL6N mice: young adults (Y, 5 mo. of age), old (O, 20 mo. of age), and very old (VO, 31 mo. of age). An additional group of old mice underwent 8-9 weeks of treadmill training (OET). Muscle mass and contractile function decreased with aging; VO animals displayed ~25% decline in maximum tetanic force vs. Y mice (p&lt;0.0001). Fatigability (assessed via repetitive sub-maximal contractions) increased by ~10% with aging but was attenuated in the OET group (p&lt;0.001). In saponin-permeabilized muscle fibers, aging did not affect mitochondrial oxidative capacity. However, H2O2 emission was nearly doubled in the O group (p&lt;0.01) and this trend was partially alleviated by exercise training. Assessed via TEM, aging decreased the size of MERCs (i.e., length of SR and OMM apposition) by around 20% (p&lt;0.01). Interestingly, OET animals displayed ~50% increase in MERC coverage (i.e., proportion of OMM covered by SR; p&lt;0.0001). Immunoblots of cellular MERC fractions revealed that MERC proteins associated with calcium exchange were altered with age and exercise. The OMM channel, VDAC1, was reduced by 20% in O muscles (p=0.02), while Grp75, a tether protein, was ~25% higher in OET (p=0.02). Quantitative proteomic analyses revealed various MERC proteins being modified by aging and exercise. Our findings indicate that changes in MERC structure and protein composition may underlie early events preceding the development of sarcopenia and that exercise-mediated adaptations at MERCs may contribute to the beneficial adaptations in aging skeletal muscle. Supported by the University of Iowa Fraternal Order of Eagles Diabetes Research Center (UIowa FOEDRC). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Aqueous humour protein dysregulation in Asian eyes with primary open angle glaucoma

The pathophysiology of Primary Open Angle Glaucoma (POAG) remains poorly understood. Through proteomic analysis of aqueous humour (AH) from POAG patients, we aim to identify changes in protein composition of these samples compared to control samples.High resolution mass spectrometry-based TMT6plex quantitative proteomics analysis is performed on AH samples collected from POAG patients, and compared against a control group of patients with cataracts. Data are available via ProteomeXchange with identifier PXD033153.1589 proteins were quantified from the aqueous samples using Proteome Discoverer version 2.2 software. Among these proteins, 210 were identified as unique master proteins. The proteins which were up or down-regulated by ±3 fold-change were considered significant. Human neuroblastoma full-length cDNA clone CS0DD006YL02 was significantly upregulated in patients with severe POAG on >2 medications, while actin, cytoplasmic 1, V2-7 protein (fragment), immunoglobulin-like polypeptide 1 and phosphatidylethanolamine-binding protein 4 were only present in these patients with severe POAG on >2 medications.Beta-crystallin B1 and B2, Gamma-crystallin C, D and S were significantly downregulated in the severe POAG ≤2 glaucoma medications group.Beta-crystallin B2, Gamma-crystallin D and GCT-A9 light chain variable region (fragment) were significantly downregulated in the non-severe POAG group.Actin, cytoplasmic 1 was significantly upregulated in subjects with severe POAG who required more than 2 glaucoma medications. Crystallins (Beta-crystallin B1 and B2, Gamma-crystallin C, D and S) were significantly downregulated in subjects with severe POAG who required less than 2 glaucoma medications.

Alteration of synaptic protein composition during developmental synapse maturation.

The postsynaptic density (PSD) is a collection of specialized proteins assembled beneath the postsynaptic membrane of dendritic spines. The PSD proteome comprises ~1000 proteins, including neurotransmitter receptors, scaffolding proteins and signalling enzymes. Many of these proteins have essential roles in synaptic function and plasticity. During brain development, changes are observed in synapse density and in the stability and shape of spines, reflecting the underlying molecular maturation of synapses. Synaptic protein composition changes in terms of protein abundance and the assembly of protein complexes, supercomplexes and the physical organization of the PSD. Here, we summarize the developmental alterations of postsynaptic protein composition during synapse maturation. We describe major PSD proteins involved in postsynaptic signalling that regulates synaptic plasticity and discuss the effect of altered expression of these proteins during development. We consider the abnormality of synaptic profiles and synaptic protein composition in the brain in neurodevelopmental disorders such as autism spectrum disorders. We also explain differences in synapse development between rodents and primates in terms of synaptic profiles and protein composition. Finally, we introduce recent findings related to synaptic diversity and nanoarchitecture and discuss their impact on future research. Synaptic protein composition can be considered a major determinant and marker of synapse maturation in normality and disease.