Protein Peptide Research Articles

MVIL6: Accurate identification of IL-6-induced peptides using multi-view feature learning

Interleukin-6 (IL-6) is a potential therapeutic target for many diseases, and it is of great significance in accurately predicting IL-6-induced peptides for IL-6 research. However, the cost of traditional wet experiments to detect IL-6-induced peptides is huge, and the discovery and design of peptides by computer before the experimental stage have become a promising technology. In this study, we developed a deep learning model called MVIL6 for predicting IL-6-inducing peptides. Comparative results demonstrated the outstanding performance and robustness of MVIL6. Specifically, we employ a pre-trained protein language model MG-BERT and the Transformer model to process two different sequence-based descriptors and integrate them with a fusion module to improve the prediction performance. The ablation experiment demonstrated the effectiveness of our fusion strategy for the two models. In addition, to provide good interpretability of our model, we explored and visualized the amino acids considered important for IL-6-induced peptide prediction by our model. Finally, a case study presented using MVIL6 to predict IL-6-induced peptides in the SARS-CoV-2 spike protein shows that MVIL6 achieves higher performance than existing methods and can be useful for identifying potential IL-6-induced peptides in viral proteins.

Advances in separation and identification of biologically important milk proteins and peptides.

Milk is a rich source of biologically important proteins and peptides. In addition, milk contains a variety of extracellular vesicles (EVs), including exosomes, that carry their own proteome cargo. EVs are essential for cell-cell communication and modulation of biological processes. They act as nature carriers of bioactive proteins/peptides in targeted delivery during various physiological and pathological conditions. Identification of the proteins and protein-derived peptides in milk and EVs and recognition of their biological activities and functions had a tremendous impact on food industry, medicine research, and clinical applications. Advanced separation methods, mass spectrometry (MS)-based proteomic approaches and innovative biostatistical procedures allowed for characterization of milk protein isoforms, genetic/splice variants, posttranslational modifications and their key roles, and contributed to novel discoveries. This review article discusses recently published developments in separation and identification of bioactive proteins/peptides from milk and milk EVs, including MS-based proteomic approaches.

Comparison of different techniques for evaluation of cellular immunity to SARS-CoV-2 virus

Most techniques for evaluation of T-cell immunity are laborious and unsuitable for routine laboratory diagnostics, thus encouraging researchers to look for accessible and reproducible tests. The purpose of our study is to compare three methods aimed for evaluation of cellular immune response levels to the SARS-CoV-2 viral antigens in patients who have been ill and vaccinated against a new coronavirus infection. We have examined 26 persons who experienced mild or moderate COVID-19 (group 1); 19 people vaccinated twice with Sputnik V, who did not have clinical COVID-19 (group 2); 21 subjects who had COVID-19 and were twice vaccinated with Sputnik V (group 3), and 14 persons who had COVID-19 twice (group 4). Peripheral blood mononuclear cells were isolated by gradient centrifugation. The first tested technique was performed as follows: the mononuclear cells were incubated with the S-protein of the SARS-CoV-2 virus, and stained with fluorescently labeled antibodies. The percentage of CD8highCD107a was counted by means of BD FACS Canto II flow cytometer. When assessed by the ELISpot method with “Human IFN-γ ELISpot” kit, IFNγ production was stimulated by SARS-CoV-2 S-protein, or a mixture of SARS-CoV-2 protein peptides in the “Corona-T-test” kit. There were no significant differences in the levels of CD107a expression on CD8high cells between the groups 1, 2, 3, and 4, as well as in amounts of IFNγ producers against SARS-CoV-2 S-protein when using “Human IFN-γ ELISpot” kit. Production of IFN was significantly lower in group 3 (hybrid immunity), i.e., 317.29±19.04 pg/ml compared to groups 1 and 2 (post-infection and post-vaccination immunity), i.e., 454.95±20.32 and 470.77±26.24 pg /ml, respectively. The relative level of IFNγ -producing cells in group 2 was higher (22.34±3.77) versus 16.83±2.35 in group 1, and 15.46±1.83 in group 3, whereas the relative levels of IFNγ did not differ in these groups. Stimulation with full-length S-protein showed a significant reduction in the number of spots in group 4 (breakthrough immunity), i.e., 30.59±2.29 vs 58.97±4.47 in group 3. Stimulation with a mixture of SARS-CoV-2 peptides in group 4 vs group 3 revealed a significantly increased number of IFNγ -producing cells (86.72±7.20 versus 69.38±5.53) and higher IFNγ production (991.25±65.18 pg/ml versus 760.76±50.70 pg/ml). Appropriate relative values were as follows: 10.30±2.77 versus 8.61±2.66, and 68.10±9.41 versus 48.35±8.15, respectively. The results of three methods for evaluation of cellular immune response correlate positively with each other, but at different significance levels.

Metabolic Processes and Biological Macromolecules Defined the Positive Effects of Protein-Rich Biostimulants on Sugar Beet Plant Development.

Protein-based biostimulants (PBBs) have a positive effect on plant development, although the biological background for this effect is not well understood. Here, hydrolyzed wheat gluten (HWG) and potato protein film (PF) in two levels (1 and 2 g/kg soil) and in two different soils (low and high nutrient; LNC and HNC) were used as PBBs. The effect of these PBBs on agronomic traits, sugars, protein, and peptides, as well as metabolic processes, were evaluated on sugar beet in comparison with no treatment (control) and treatment with nutrient solution (NS). The results showed a significant growth enhancement of the plants using HWG and PF across the two soils. Sucrose and total sugar content in the roots were high in NS-treated plants and correlated to root growth in HNC soil. Traits related to protein composition, including nitrogen, peptide, and RuBisCO contents, were enhanced in PBB-treated plants (mostly for HWG and PF at 2 g/kg soil) by 100% and >250% in HNC and LNC, respectively, compared to control. The transcriptomic analysis revealed that genes associated with ribosomes and photosynthesis were upregulated in the leaf samples of plants treated with either HWG or PP compared to the control. Furthermore, genes associated with the biosynthesis of secondary metabolites were largely down-regulated in root samples of HWG or PF-treated plants. Thus, the PBBs enhanced protein-related traits in the plants through a higher transcription rate of genes related to protein- and photosynthesis, which resulted in increased plant growth, especially when added in certain amounts (2 g/kg soil). However, sucrose accumulation in the roots of sugar beet seemed to be related to the easy availability of nitrogen.

Copper ions and the R peptides of tau: structural and functional study

AbstractBackgroundOne of the common neurodegenerative disorders is the aggregation of Tau protein plays a major role in Alzheimer’s disease. Transmission metals ions such as Cu, Zn, and Fe are vital ingredients that must maintain homeostasis in the biological system. Tau Protein has four repeat peptide units (R1 R2 R3 R4) which may coordinate divalent copper ions to form neurofibrillary tangles (NFTs) and generate reactive oxygen species (ROS).The abnormal amount of Cu2+ accumulation in the intracellular environment, regulating the biological systems is not clearly understood.MethodThe main objective of this study was to evaluate the coordination of four R peptides to Cu2+ by MALDI‐MS‐TOF and determine the interaction of Cu2+ ions with peptides (R1 R2 R3 R4) of Tau protein in vitro. Also, their role in the formation of ROS with a natural reducing agent‐ ascorbate was probed.ResultAs the principal findings of this experiment, metal ion coordinated all 4 R peptides, via His and Cys residue including N terminal and amide groups. All the metallo‐peptide complexes were singly charged peaks, and observed even in the presence of ascorbate. R2 and R3 peptides formed the homodimers by disulfide bond formation. The metallo‐peptides were antioxidants and prooxidants depending on the conditions, indicating that a complex behavior may exist in the biological setting.ConclusionThis work indicates that metal ions interact with R peptides, which may mitigate ROS levels. The finding of this study is greatly beneficial for understanding the Tau protein behavior to develop a potential medication.

Routine laboratory parameters in estimating mortality and morbidity in COVID-19 diagnosed cases followed in the intensive care unit.

In this study, our goal was to assess the neutrophil/lymphocyte, platelet/lymphocyte ratios, urea/albumin, lactate, C-reactive protein/albumin procalcitonin/albumin, dehydrogenase/albumin, and protein/albumin rates in 368 critical COVID-19 cases following the entrance to the intensive care unit (ICU) to investigate the effects of biomarkers on prognosis and mortality. The Ethics Committee approved this study carried out in our hospital's intensive care units between March 2020 and April 2022. 368 patients, 220 (59.8%) male, and 148 (40.2%) female, diagnosed with COVID-19 and aged between 18 and 99 years were included in this research. The average age of non-survivors was statistically considerably higher than survivors (p<0.05). There was no numerical significance in terms of gender concerning mortality (p>0.05). The duration of ICU stay was statistically considerably prolonged in survivors than in those who did not survive (p<0.05). The leukocytes, neutrophils, urea, creatinine, ferritin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), creatine kinase (CK), C-reactive protein (CRP), procalcitonin (PCT), and pro-brain natriuretic peptide (pro-BNP) levels were numerically considerably higher in the non-survivors (p<0.05). The platelet, lymphocyte, protein, and albumin levels statistically considerably declined in non-survivors in comparison with survivors (p<0.05). Acute renal failure (ARF) increased mortality by 31.815-fold, ferritin by 0.998-fold, pro-BNP by 1-fold, procalcitonin by 574.353-fold, neutrophil/lymphocyte by 1.119-fold, CRP/albumin by 2.141-fold, and protein/albumin by 0.003-fold. It was found that the number of days in the ICU increased mortality by 1.098-fold, creatinine by 0.325-fold, CK by 1.007-fold, urea/albumin by 1.079-fold, and LDH/albumin by 1.008-fold.

A Novel Approach for Screening Sericin-Derived Therapeutic Peptides Using Transcriptomics and Immunoprecipitation.

With the demand for more efficient and safer therapeutic drugs, targeted therapeutic peptides are well received due to their advantages of high targeting (specificity), low immunogenicity, and minimal side effects. However, the conventional methods of screening targeted therapeutic peptides in natural proteins are tedious, time-consuming, less efficient, and require too many validation experiments, which seriously restricts the innovation and clinical development of peptide drugs. In this study, we established a novel method of screening targeted therapeutic peptides in natural proteins. We also provide details for library construction, transcription assays, receptor selection, therapeutic peptide screening, and biological activity analysis of our proposed method. This method allows us to screen the therapeutic peptides TS263 and TS1000, which have the ability to specifically promote the synthesis of the extracellular matrix. We believe that this method provides a reference for screening other drugs in natural resources, including proteins, peptides, fats, nucleic acids, and small molecules.

Chitosan complexes with amino acids and whey peptides: Sensory and antioxidant properties

Chitosan reacts with amino acids and hydrolyzed whey proteins to produce biologically active complexes that can be used in functional foods. The research objective was to obtain chitosan biocomposites with peptides and amino acids with improved antioxidant and sensory properties. &#x0D; The research featured biocomposites of chitosan and succinylated chitosan with whey peptides and amino acids. The methods of pH metry and spectrophotometry were employed to study the interaction parameters between polysaccharides and peptides, while colorimetry and spectrophotometry served to describe the amino acids content. The antiradical effect was determined by the method of fluorescence recovery. Pure compounds and their complexes underwent a sensory evaluation for bitterness. &#x0D; Chitosan and succinylated chitosan formed complexes with whey peptides and such proteinogenic amino acids as arginine, valine, leucine, methionine, and tryptophan. The equimolar binding of tryptophan, leucine, and valine occurred in an aqueous chitosan solution (in terms of glucosamine). Methionine appeared to be the least effective in chitosan interaction, while arginine failed to complex both with chitosan and succinylated chitosan. Chitosan and succinylated chitosan biocomposites with peptides and leucine, methionine, and valine proved to be less bitter that the original substances. The samples with arginine maintained the same sensory properties. Chitosan complexes with tryptophan and peptides increased their antioxidant activity by 1.7 and 2.0 times, respectively, while their succinylated chitosan complexes demonstrated a 1.5 fold increase.&#x0D; Chitosan and succinylated chitosan biocomplexes with tryptophan and whey protein peptides had excellent antioxidant and sensory properties. However, chitosan proved more effective than succinylated chitosan, probably, because it was richer in protonated amino groups, which interacted with negatively charged amino acids groups.

Association between echocardiographic features and inflammatory biomarkers with clinical outcomes in COVID-19 patients in Saudi Arabia.

Respiratory infections are one of the most common comorbidities identified in hospitalized patients. The coronavirus disease 2019 (COVID-19) pandemic greatly impacted healthcare systems, including acute cardiac services. This study aimed to describe the echocardiographic findings of patients with COVID-19 infections and their correlations with inflammatory biomarkers, disease severity, and clinical outcomes. This observational study was conducted between June 2021 and July 2022. The analysis included all patients diagnosed with COVID-19 who had transthoracic echocardiographic (TTE) scans within 72 h of admission. The enrolled patients had a mean age of 55.6 ± 14.7 years, and 66.1% were male. Of the 490 enrolled patients, 203 (41.4%) were admitted to the intensive care unit (ICU). Pre-ICU TTE findings showed significantly higher incidence right ventricular dysfunction (28 [13.8%] vs. 23 [8.0%]; P = 0.04) and left ventricular (LV) regional wall motion abnormalities (55 [27.1%] vs. 29 [10.1%]; p < 0.001) in ICU patients compared to non-ICU patients. In-hospital mortality was 11 (2.2%), all deaths of ICU patients. The most sensitive predictors of ICU admission (p < 0.05): cardiac troponin I level (area under the curve [AUC] = 0.733), followed by hs-CRP (AUC = 0.620), creatine kinase-MB (AUC = 0.617), D-dimer (AUC = 0.599), and lactate dehydrogenase (AUC = 0.567). Binary logistic regression showed that reduced LV ejection fraction (LVEF), elevated pulmonary artery systolic pressure, and dilated right ventricle were echocardiographic predictors of poor outcomes (p < 0.05). Echocardiography is a valuable tool in assessing admitted patients with COVID-19. Lower LVEF, pulmonary hypertension, higher D-dimer, C-reactive protein, and B-type natriuretic peptide levels were predictors of poor outcomes.

Health-promoting activities of Moringa oleifera Lam. seeds protein hydrolysates and its ultra-filtered peptide fractions

Moringa oleifera (MO) seeds treated as a new resource food rich in protein (37.48%), but, little know the bioactive benefits and peptide composition of protein hydrolysates. In this study, ultrafiltrated peptide fractions of MO seed proteins hydrolysates (MOSPH) were analyzed for their antioxidant, anti-hypertension and sleep-promoting activities. LC-MS/MS was used to identify the peptide composition of the molecular weight (MW) <3 kDa fraction. The results showed that MOSPH and the lower MW peptides fraction, especially the MW <3 kDa fraction, exhibited higher free radical scavenging and reducing capacity, in vitro angiotensin I-converting enzyme (ACE) inhibitory capacity and vasodilatory and anti-hypertensive effects on spontaneously hypertensive rats (SHR) after the development of hypertension, sleep-promoting and anticonvulsant effects in male ICR mice. Furthermore, four potential bioactive peptides (pepsite score > 0.3) from MW <3 kDa fraction of MOSPH were explored via in silico approach, of which a novel dual-function peptide IWHHTFYNELR (IR-11) exhibited higher ACE inhibitory activity (IC50 = 1.057 mg/mL) and DPPH•-clearing activity (IC50 = 0.404 mg/mL). Molecular docking indicates that IR-11 interacted with ACE and DPPH• through hydrogen bonding and hydrophobic forces. Our results suggested that MO seed proteins peptides can be a potent functional agents for developing new functional food.

A peptide of PilZ domain-containing protein controls wastewater-treatment-membrane biofouling by inducing bacterial attachment

Membrane-based wastewater reclamation is used to mitigate water scarcity; however, irreversible biofouling is an elusive problem that hinders the efficiency of a forward-osmosis (FO) membrane-based process, and the protein responsible for fouling is unknown. Herein, we identified fouling proteins by analyzing the microbiome and proteome of wastewater extracellular polymeric substances responsible for strong irreversible FO-membrane fouling. The IGLSSLPR peptide of a PilZ domain-containing protein was found to recruit bacterial attachment when immobilized on the membrane surface while suppressing it when dissolved, in a similar manner to the Arg-Gly-Asp (RGD) peptide in mammalian cell cultures. Bacteria adhere to IGLSSLPR and poly-l-lysine-coated membranes with similar energies and exhibit water fluxes that decline similarly, which is ascribable to interaction as strong as electrostatic interactions in the peptide-coated membranes. We conclude that IGLSSLPR is the key domain responsible for membrane fouling and can be used to develop antifouling technology against bacteria, which is similar to the current usage of RGD peptide in mammalian cell cultures.

Production of monoclonal antibody of heat-labile toxin A subunit to identify enterotoxigenic Escherichia coli by epitope mapping using synthetic peptides.

Enterotoxigenic Escherichia coli (ETEC) is a major cause of diarrhea through two enterotoxins, a heat-labile toxin and a heat-stable toxin. These toxins alter the cellular signaling pathways, ultimately triggering an increase in chloride secretion and watery diarrhea. For the development of an ETEC vaccine, we attempted to construct a peptide-specific monoclonal antibody library against heat-labile enterotoxin A subunit (LT-A) by epitope mapping using synthetic peptides. Sera produced by five mice immunized with recombinant LT-A protein were examined for specific recognition with synthetic 15-mer and 34-mer peptides of LT-A proteins using enzyme-linked immunosorbent assay. The analysis revealed that the synthetic peptides number 8, 16, 24, 33, 36, 38, and 39 reacted with an anti-LT-A polyclonal antibody. For the possible prediction of LT-A epitopes, each full-length protein sequence was subjected to BCPreds analysis and three-dimensional protein structure analysis. The data showed that three peptides (synthetic peptide numbers: 33, 36, and 38-39) have identical antigenic specificities with LT-A protein, suggesting the usefulness of these linear peptide epitopes. Based on these peptides, we produced monoclonal antibodies to improve the specificity of LT-A detection. Monoclonal antibodies produced from two peptides (numbers 33 and 36) showed affinity for an LT-A recombinant antigen. Moreover, peptide epitope prediction analysis showed that the sites of the three peptides were identical to those exhibiting actual antigenicity. Also, it was confirmed that the amino acid sequence that actually showed antigenicity was included in the peptide predicted only by ETEC-LT-A-33. Also, the specificity of the antibody for ETEC-LT-A-33 was validated using bacterial cells, and the neutralizing effect of the antibody was determined by assessing cytokine release in infected HCT-8 cells. The monoclonal antibodies produced in this study are useful toolsfor vaccine production against ETEC and can be used to identify peptide antigencandidates.

The Problem of Bitter Peptides Formed in the Process of Cheese Ripening

Bitter peptides are formed by the breakdown of proteins and high-molecular peptides during proteolysis. Their formation in cheeses is related to the proteolytic activity of rennet in balance with the peptidase activity of microbial enzymes of lactic acid bacteria. The bitter taste then arises when there is a disproportion between the formation and degradation of bitter peptides by increasing their concentration above the perception threshold. The extent to which bitter peptides affect the overall taste of cheese depends on the balance between their formation and breakdown to non-bitter lower peptides and amino acids. Only a perfectly balanced proteolysis process enables the creation of quality matured cheese with a characteristic taste and aroma. Therefore, a complete clarification of the mechanism is desirable, and thus also the possibility of control and regulation of this process.

Predicting Protein-Peptide Interactions: Benchmarking Deep Learning Techniques and a Comparison with Focused Docking.

The accurate prediction of protein structures achieved by deep learning (DL) methods is a significant milestone and has deeply impacted structural biology. Shortly after its release, AlphaFold2 has been evaluated for predicting protein-peptide interactions and shown to significantly outperform RoseTTAfold as well as a conventional blind docking method: PIPER-FlexPepDock. Since then, new AlphaFold2 models, trained specifically to predict multimeric assemblies, have been released and a new ab initio folding model OmegaFold has become available. Here, we assess docking success rates for these new DL folding models and compare their performance with our state-of-the-art, focused peptide-docking software AutoDock CrankPep (ADCP). The evaluation is done using the same dataset and performance metric for all methods. We show that, for a set of 99 nonredundant protein-peptide complexes, the new AlphaFold2 model outperforms other Deep Learning approaches and achieves remarkable docking success rates for peptides. While the docking success rate of ADCP is more modest when considering the top-ranking solution only, it samples correct solutions for around 62% of the complexes. Interestingly, different methods succeed on different complexes, and we describe a consensus docking approach using ADCP and AlphaFold2, which achieves a remarkable 60% for the top-ranking results and 66% for the top 5 results for this set of 99 protein-peptide complexes.

Protein aggregation impacts in vitro protein digestibility, peptide profiling and potential bioactive peptides of soymilk and dry-heated soybeans

Protein aggregates and in vitro digestibility of soymilk, 160 °C and 200 °C dry-heated soybeans (DHS) were investigated. The results showed that, different from the soluble protein aggregates in soymilk, thermal treatment led to formation of increased insoluble aggregates in 160 °C DHS via non-covalent bonds (hydrogen bonds and hydrophobic interactions). However, covalent bonds (protein oxidation-induced crosslinking) were predominant forces for insoluble aggregates in 200 °C DHS. The order of in vitro digestibility was 160 °C DHS > soymilk >200 °C DHS (p < 0.05). More types of peptides were identified from 160 °C DHS (2,230) than soymilk (2,104) and 200 °C DHS (2,130). Soymilk and 200 °C DHS had similar peptides distribution and sequence alignment; while 160 °C DHS generated unique peptides. Moreover, potential bioactive peptides and antimicrobial peptides were all found in the three samples. Thus, protein aggregates, caused by different cooking methods, affected protein digestibility and peptide composition.

Citrus pomace co-fermentation improved its protein and amino acids by Bacillus amyloliquefaciens and Candida utilis

High-value utilization of citrus pomace (CP) is of great significance to the sustainable development of the citrus industry. Co-fermentation of CP was investigated using the autochthonous probiotic bacteria, Bacillus amyloliquefaciens BF2 and Candida utilis GIM 2.9. Crude protein, soluble protein, and small peptide content of CP increased by 40.01%, 923.53%, and 626.67% after fermentation, respectively. Essential amino acids increased from 28.51% to 47.04% of total free amino acids. Leucine level reached 4.04 mg/g DW, increasing by 1293.10%, and produced histidine, valine, cysteine, and tyrosine. Scanning electron microscopy results showed that BF2 and GIM 2.9 could effectively degrade and utilize the CP fibers. Enzymolysis co-fermentation (ECF) system secreted higher levels of non-starch polysaccharide enzymes and proteases than co-fermentation (CF) system. Acid protease activity was positively correlated with soluble protein and free amino acid contents. BF2 possessed 63 essential amino acid-biosynthesis genes, nearly twice as many as that of non-essential amino acids. Eight key enzyme genes were identified for leucine biosynthesis in the BF2 genome, suggesting that BF2 played a key role in leucine biosynthesis. Our results provide a potential method for the high-value utilization of CP as a protein feed additive or dietary supplement.

Quantification of SARS-CoV-2 spike protein expression from mRNA vaccines using isotope dilution mass spectrometry

The advent of mRNA vaccine technology has been vital in rapidly creating and manufacturing COVID-19 vaccines at an industrial scale. To continue to accelerate this leading vaccine technology, an accurate method is needed to quantify antigens produced by the transfection of cells with a mRNA vaccine product. This will allow monitoring of protein expression during mRNA vaccine development and provide information on how changes to vaccine components affects the expression of the desired antigen. Developing novel approaches that allow for high-throughput screening of vaccines to detect changes in antigen production in cell culture prior to in vivo studies could aid vaccine development. We have developed and optimized an isotope dilution mass spectrometry method to detect and quantify the spike protein expressed after transfection of baby hamster kidney cells with expired COVID-19 mRNA vaccines. Five peptides of the spike protein are simultaneously quantified and provide assurance that protein digestion in the region of the target peptides is complete since results between the five peptides had a relative standard deviation of less than 15 %. In addition, two housekeeping proteins, actin and GAPDH, are quantified in the same analytical run to account for any variation in cell growth within the experiment. IDMS allows a precise and accurate means to quantify protein expression by mammalian cells transfected with an mRNA vaccine.

Thymosin Beta 4 Protects Hippocampal Neuronal Cells against PrP (106-126) via Neurotrophic Factor Signaling.

Prion protein peptide (PrP) has demonstrated neurotoxicity in brain cells, resulting in the progression of prion diseases with spongiform degenerative, amyloidogenic, and aggregative properties. Thymosin beta 4 (Tβ4) plays a role in the nervous system and may be related to motility, axonal enlargement, differentiation, neurite outgrowth, and proliferation. However, no studies about the effects of Tβ4 on prion disease have been performed yet. In the present study, we investigated the protective effect of Tβ4 against synthetic PrP (106-126) and considered possible mechanisms. Hippocampal neuronal HT22 cells were treated with Tβ4 and PrP (106-126) for 24 h. Tβ4 significantly reversed cell viability and reactive oxidative species (ROS) affected by PrP (106-126). Apoptotic proteins induced by PrP (106-126) were reduced by Tβ4. Interestingly, a balance of neurotrophic factors (nerve growth factor and brain-derived neurotrophic factor) and receptors (nerve growth factor receptor p75, tropomyosin related kinase A and B) were competitively maintained by Tβ4 through receptors reacting to PrP (106-126). Our results demonstrate that Tβ4 protects neuronal cells against PrP (106-126) neurotoxicity via the interaction of neurotrophic factors/receptors.

Foliar application of fish protein peptide improved the quality of deep-netted melon

To improve the fruit quality of deep-netted melon, fish protein peptide (FPP) with a total protein content greater than 90% at a concentration of 1 g·L−1 was sprayed on leaves after pollination, distilled water was sprayed on the control plants (CK). Field indices such as single melon fresh mass, commercial fruit rate, yield and fruit nutrient contents were evaluated. Soluble sugar, starch, organic acid and the activities of enzymes related to sugar metabolism in the inner, middle and outer layers of melon flesh were also determined. The results showed that the commercial fruit rate and yield per hectare increased by 8.96% and 5.98%, respectively. Nutrient contents increased, including the total amounts of 16 amino acids were 0.34 g/100 g higher than those of CK, and the mineral element contents increased by 15.79%, among which the contents of potassium, phosphorus, zinc, calcium, magnesium and molybdenum were significantly different from those of CK (p < 0.05). FPP treatment significantly increased the soluble sugar content in the outer layer of the mesocarp of deep-netted melon and the ascorbic acid contents in the inner and middle layers of the mesocarp of deep-netted melon. FPP increased sucrose accumulations in fruit by decreasing the activity of neutral invertase (NI), increasing the activity of sucrose phosphate synthase (SPS) and the synthesis direction of sucrose synthase (SS), and by increasing the glucose and fructose contents by enhancing the activity of acid invertase (AI). These findings suggest that exogenous FPP improves the commercial fruit rate, yield, and quality of deep-netted melon.

Porcine circovirus type 3: immunohistochemical detection in lesions of naturally affected piglets.

This study aimed to evaluate the relationship between porcine circovirus type 3 (PCV3) viral load and histopathological findings in perinatal piglet tissues and to develop an immunohistochemical method for detecting the virus in lesions. The quantitative polymerase chain reaction (qPCR) cycle threshold (Ct) when amplifying PCV3 DNA and the area of perivascular inflammatory infiltrates in different organs [central nervous system (CNS), lung, heart, liver, spleen, and lymph nodes] were compared. To develop an immunohistochemistry technique, rabbit sera were produced against PCV3-capsid protein peptides selected using bioinformatic analyses. The assay was initially implemented using a tissue sample previously tested using qPCR and in situ hybridization to optimize the procedure and reagent dilutions. To evaluate immunohistochemistry performance, tissue samples from another 17 cases were analyzed using standardized parameters. The most common microscopic lesion was multisystemic periarteritis, with associated vasculitis, as the mesenteric vascular plexus is one of the most affected organs. Other tissues, such as the heart, lung, CNS, and skeletal muscle, were also affected. Comparison of the Ct values for different tissues showed no significant difference, except in lymphoid organs (spleen and lymph nodes), which had significantly higher viral loads than the CNS tissues. There was no correlation between Ct values and perivascular inflammatory infiltrates. PCV3 immunohistochemistry revealed granular immunolabeling, mainly in the cytoplasm of cells in the vascular mesenteric plexus, heart, lung, kidney, and spleen.