NLRP3-dependent pyroptosis exacerbates coxsackievirus A16 and coxsackievirus A10-induced inflammatory response and viral replication in SH-SY5Y cells

Coxsackievirus A16 (CV-A16) and coxsackievirus A10 (CV-A10), more commonly etiological agents of hand, foot and mouth disease (HFMD), are capable of causing severe neurological syndromes with high fatalities, but their neuropathogenesis has rarely been studied. Mounting evidence indicated that pyroptosis is an inflammatory form of cell death that might be widely involved in the pathogenic mechanisms of neurotropic viruses. Our study was designed to examine the effects of NLRP3-mediated pyroptosis in CV-A16- and CV-A10-induced inflammatory neuropathologic formation. In this work, it was showed that SH-SY5Y cells were susceptible to CV-A16 and CV-A10, and meanwhile their infections could result in a decreasing cell viability and an increasing LDH release as well as Caspase1 activation. Moreover, CV-A16 and CV-A10 infections triggered NLRP3-mediated pyroptosis and promoted the release of inflammatory cytokines. Additionally, activated NLRP3 accelerated the pyroptosis formation and aggravated the inflammatory response, but inhibited NLRP3 had a dampening effect on the above situation. Finally, it was further revealed that NLRP3 agonist enhanced the viral replication, but NLRP3 inhibitor suppressed the viral replication, suggesting that NLRP3-driven pyroptosis might support CV-A16 and CV-A10 production in SH-SY5Y cells. Together, our findings demonstrated a mechanism by which CV-A16 and CV-A10 induce inflammatory responses by evoking NLRP3 inflammasome-regulated pyroptosis, which in turn further stimulated the viral replication, providing novel insights into the pathogenesis of CV-A16 and CV-A10 infections.

Decoding the Effect of Running on Flavor Perception Changes during Consumption of Sports Drinks

An online survey was conducted to show that most respondents preferred sports drinks with sweet and fruity characteristics. Eleven sports drinks with higher consumers' preferences were further selected for aroma and taste evaluation. Temporal dominance of sensations analysis showed that fruity and fresh attributes were dominant, while sour and fruity sweet were dominant tastes during consumption. β-Damascenone, β-ionone, and linalool contributing to floral perception, γ-decalactone, ethyl cinnamate, and isoamyl acetate contributing to fruity perception, and menthol contributing to fresh perception were confirmed by odor activity value analysis. Running affected the nasal air flow and the saliva secretion, resulting in the flavor perception changing from fruity sweet, sweet, and fruity to sour because the recognition threshold decreased for sweet, fruity, floral, and fresh flavors and increased for saltiness, astringency, and sour tastes.

Electronic tongue, proton-transfer-reaction mass spectrometry, spectral analysis, and molecular docking characterization for determining the effect of α-amylase on flavor perception

The effects of α-amylase on of flavor perception were investigated via spectrum analysis, electronic tongue, on-line mass spectrometry, and molecular docking. Aroma release results showed that α-amylase exhibited variable release patterns of different aroma compounds. Electronic tongue analysis showed that the perception of bitterness, sweetness, sour, and saltiness was subtly increased and that of umami was significantly increased (p < 0.01) along with the increasing enzyme activity of α-amylase. Ultraviolet absorption and fluorescence spectroscopy analyses showed that static quenching occurred between α-amylase and eight flavor compounds and their interaction effects were spontaneous. One binding pocket was confirmed between the α-amylase and flavor compounds, and molecular docking simulation results showed that the hydrogen, electrostatic, and hydrophobic bonds were the main force interactions. The TYP82, TRP83, LEU173, HIS80, HIS122, ASP297, ASP206, and ARG344 were the key α-amylase amino acid residues that interacted with the eight flavor compounds.

Decoding the Different Aroma-Active Compounds in Soy Sauce for Cold Dishes via a Multiple Sensory Evaluation and Instrumental Analysis

Screening the suitability of soy sauce for specific cooking methods from various products is beneficial for the fine development of the soy sauce industry. Multiple sensory evaluation and gas chromatography-mass spectrometry/olfactometry (GC-MS/O) analysis were combined to decode the suitability of soy sauces for cold dishes and characterize their differential aroma-active compounds. Thirty-two kinds of soy sauce with 42 sensory descriptors were determined via a check-all-that-apply analysis, and werefurther classified into six categories via a cluster analysis. The sensory evaluation results showed that seven soy sauce samples had the highest acceptance in each category. Solid-phase microextraction and solid phase extraction results combined with the GC-MS/O analysis results showed that a total of 38 aroma-active compounds were identified in seven soy sauce samples, among which 2-methoxy-phenol (6-93), ethyl acetate (2-48), 3-methyl-1-butanol (4-30), 3-methyl-butanal (5-24), methional (0-22), dimethyl trisulfide (5-19) and dimethyl disulfide (0-8) showed a higher relative odor activity value (ROAV). A partial least squares regression prediction combined with additional tests further confirmed that 2,5-dimethyl-pyrazine; 2,6-dimethyl-pyrazine; and 2-ethyl-6-methyl-pyrazine significantly contributed to the roasted attributes, methional significantly contributed to the sauce-like notes, ethanol significantly contributed to the alcoholic notes and 2-methoxy-phenol significantly contributed to the smoky notes. 2,5-Dimethyl-pyrazine; methional; 2,6-dimethyl-pyrazine and 2-ethyl-6-methyl-pyrazine significantly contributed to the caramel-like attributes.

The neuropathological mechanism of EV-A71 infection attributes to inflammatory pryoptosis and viral replication via activating the hsa_circ_0045431/ hsa_miR_584/NLRP3 regulatory axis

Neuropathological damage has been considered to be the main cause of death from EV-A71 infection, but the underlying mechanism has not been elucidated. Pyroptosis, a new form of inflammatory programmed cell death, has been verified to be involved in the pathogenesis of various viruses. circRNAs are a novel type of endogenous noncoding RNA gaining research interest in recent years, especially their special roles in the process of virus infection. Thus, in this study, we combined EV-A71, pyroptosis and circRNA to find a breakthrough in the pathogenesis of EV-A71 infection. Firstly, whether EV-A71 infection leaded to pyroptosis formation was examined by a series detection of cell death, cell viability, LDH release, caspase 1 activity, the expression levels of pyroptosis-related molecules and the concentrations of IL-1β and IL-18. Secondly, high-throughput sequencing of circRNAs was carried out to excavate the circRNA-miRNA-mRNA regulatory axis which might be associated with pyroptosis formation. Finally, the gain- and loss-of-functional experiments were further conducted to identify their functions. Our results showed that EV-A71 infection caused pyroptosis formation in SH-SY5Y cells. The circRNA sequencing analyzed the differentially expressed circRNAs and their possible functions. It was found that the hsa_circ_0045431/hsa_miR_584/NLRP3 regulatory axis might be involved in pyroptosis formation during EV-A71 infection. Then, hsa_circ_0045431 sponged hsa_miR_584 and hsa_miR_584 directly targeted NLRP3 were validated by IF, dual-luciferase, qRT-PCR and WB assays. Functional experiments were performed to further uncover that the up-regulation of hsa_circ_0045431 and NLRP3 promoted the inflammatory pyroptosis and viral replication, while the up-regulation of hsa_miR_584 suppressed the inflammatory pyroptosis and viral replication, and vice versa. Collectively, our study demystified that EV-A71 infection induced pyroptosis formation by activating hsa_circ_0045431/hsa_miR_584/NLRP3 regulatory axis, which could further effect viral replication. These findings provided novel insights into the pathogenesis of EV-A71 infection, and meanwhile revealed that the hsa_circ_0045431/ hsa_miR_584/NLRP3 regulatory axis can serve as a potential biological therapeutic target for EV-A71 infection.

Molecular mechanisms of caramel-like odorant-olfactory receptor interactions based on a computational chemistry approach

Molecular mechanisms of caramel-like odorant-olfactory receptor interactions were investigated based on molecular docking and molecular dynamics simulations. The transmembrane regions TM-3, TM-5 and TM-6 of receptors were main contributors of amino acid residues in the docking. Molecular docking results showed that hydrogen bonding and pi-pi stacking were the key forces for the stabilization of caramel-like odorants. The binding energies were positively correlated with the molecular weight of caramel-like odorants. Residues Asn155 (84%, OR2W1), Asn206 (86%, OR8D1), Ser155 (77%, OR8D1), Asp179 (87%, OR5M3), Val182 (84%, OR2J2) and Tyr260 (94%, OR2J2) with high frequencies played an important role in the complexes formation. Odorants 4-hydroxy-5-methylfuran-3(2H)-one (16#) and methylglyoxal (128#) were screened by molecular field-based similarity analysis, which tended to bind to the receptors OR1G1 and OR52H1 respectively, resulting a caramel-like aroma perception. The obtained results are useful for better understanding the perception of caramel-like odorants and their high-throughput screening.

Characterization of the Key Aroma Compounds in Different Yeast Proteins by GC-MS/O, Sensory Evaluation, and E-Nose

The unique odors of yeast proteins (YPs) are decisive for their application in meat substitutes. Sensory evaluation, electronic nose, and gas chromatography-mass spectrometry/olfactory (GC-MS/O) were combined to characterize the aroma profiles and aroma-active compounds of YPs. The sensory evaluation results indicate that the sweaty aroma had the strongest intensity in YP #10, followed by rice bran, sour, and plastic. The electronic nose could effectively distinguish the aroma differences among five YPs. A total of 27 aroma-active compounds in the five YPs were identified by GC-MS/O. The concentration of 2-methyl-propanoic acid (6.37 μg/kg), butanoic acid (47.46 μg/kg), 3-methyl-butanoic acid (22.50 μg/kg), and indole (943.40 μg/kg) in YP #10's aroma was higher than that of the other YPs. The partial least squares regression method results show that o-cresol, (3S)-3,7-dimethyloct-7-en-1-ol, benzyl alcohol, octanal, 2-methyl-propanoic acid, butanoic acid, 3-methyl-butanoic acid, hexanal, heptanal, and indole were predicted as the potential aroma-active compounds significantly contributing to the aroma profiles of the five YPs. Addition experiments confirmed that the overall aroma profile intensities of the five YP samples were extended with the addition of these ten compounds, verifying their significant contributions.

Identification of Novel Umami Peptides in Chicken Breast Soup through a Sensory-Guided Approach and Molecular Docking to the T1R1/T1R3 Taste Receptor

Ultrafiltration combined with nanoliquid chromatography quadrupole time-of-flight mass spectrometry (nano-LC-QTOF-MS) and sensory evaluation was used to separate and identify umami peptides in chicken breast soup. Fifteen peptides with umami propensity scores of >588 were identified from the fraction (molecular weight ≤1 kDa) using nano-LC-QTOF-MS, and their concentrations ranged from 0.02 ± 0.01 to 6.94 ± 0.41 μg/L in chicken breast soup. AEEHVEAVN, PKESEKPN, VGNEFVTKG, GIQKELQF, FTERVQ, and AEINKILGN were considered as umami peptides according to sensory analysis results (detection threshold: 0.18-0.91 mmol/L). The measurement of point of subjective equality showed that these six umami peptides (2.00 g/L) were equivalent to 0.53-0.66 g/L of monosodium glutamate (MSG) in terms of umami intensity. Notably, the sensory evaluation results showed that the peptide of AEEHVEAVN significantly enhanced the umami intensity of the MSG solution and chicken soup models. The molecular docking results showed that the serine residues were the most frequently observed binding sites in T1R1/T1R3. The binding site Ser276 particularly contributed to the formation of the umami peptide-T1R1 complexes. The acidic glutamate residues observed in the umami peptides were also involved in their binding to the T1R1 and T1R3 subunits.

Decoding the Effect of Age on the Taste Perception of Chicken Breast Soup Based on LC-QTOF-MS/MS Combined with a Chemometric Approach

A nontargeted fingerprinting approach combined with the chemometrics method and sensory analysis was used to assess the differences in taste-chemical compositions of chicken breast soup with different ages and their sensory qualities. The sensory evaluation results showed that the overall taste as well as the sourness, saltiness, and umami scores of the soup were increased with the age of chicken. Fifty-nine compounds were identified from four soup samples by liquid chromatography-tandem quadrupole time-of-flight mass spectrometry (LC-QTOF-MS/MS), and their total content was the highest in the 90 wk soup samples. Six upregulated compounds (carnosine, hypoxanthine, inosine, inosine 5'-monophosphate (5'-IMP), adenosine 5'-monophosphate (5'-AMP), and lactic acid) were identified as potential contributors to the taste characteristics of the 90 wk soup samples by orthogonal projections to latent structures-discriminant analysis (OPLS-DA). Additional experiments showed that 5'-AMP particularly contributed to the sourness of the soup, while carnosine contributed to the saltiness and umami of the soup.

Development of an Effective Protocol for Evaluating the Saltiness Intensity Enhancement of Umami Compounds

Reducing sodium intake without decreasing saltiness perception remains an important target in the food industry. This study developed an effective protocol for evaluating the saltiness perception enhanced by umami compounds. Two sodium chloride solutions (2.00 and 6.00 g/L) were the preferred concentrations for consumers. Two-alternative forced-choice evaluation results confirmed that at a concentration of 2.00 g/L (sodium concentration), the highest replacement ratios of monosodium glutamate and l-alanine (Ala) were 10 and 20% in sodium chloride solution without saltiness intensity decrease, respectively. The highest replacement ratios of l-glycine (Gly) and Ala were 10 and 20% compared to 6.00 g/L, respectively. Temporal dominance of sensations analysis figured out that gum Arabic (GA) could compensate for the decrease of the retention time and increase the overall saltiness perception in the sodium-reduced sample. Quartz crystal microbalance with dissipation results showed that Ala and Gly could inhibit the binding of Na⁺ to mucin, thereby increasing the saltiness perception. GA exhibited the best saltiness enhancement effect in sodium-reduced solution by producing the nanoparticles from GA, decreasing the stability of the solution system, enhancing the loading effect of mucin on Na⁺, and prolonging the saltiness perception.

Decoding of the Saltiness Enhancement Taste Peptides from the Yeast Extract and Molecular Docking to the Taste Receptor T1R1/T1R3

The development of saltiness or saltiness enhancement peptides is important to decrease the dietary risk factor of high sodium. Taste peptides in the yeast extract were separated by ultrafiltration and subsequently identified by UPLC-Q-TOF-MS/MS. The 377 identified peptides were placed into the umami receptor T1R1/T1R3. The results showed that eight taste peptides with higher binding energies were screened by molecular virtual docking, and the results revealed that Asp218, Ser276, and Asn150 of T1R1 play key roles in umami docking of peptides. The taste characteristic description and saltiness enhancement effect results suggested that PKLLLLPKP (sourness and umami, 0.18 mM), GGISTGNLN (sourness, 0.59 mM), LVKGGLIP (umami, 0.28 mM), and SSAVK (umami, 0.35 mM) had higher saltiness enhancement effects. The sigmoid curve analysis further confirmed that the taste detection threshold of the GGISTGNLN in the peptide and salt model (157.47 mg/L) was lower than 320.99 mg/L and exhibited a synergistic effect on saltiness perception, whereas SSAVK, PKLLLLPKP, and LVKGGLIP exhibited additive effects on the saltiness perception. This work also corroborated previous research, which indicated that the sourness and umami taste attributes could enhance the saltiness perception.

Recent Progress in the Study of Taste Characteristics and the Nutrition and Health Properties of Organic Acids in Foods

Organic acids could improve the food flavor, maintain the nutritional value, and extend the shelf life of food. This review summarizes the detection methods and concentrations of organic acids in different foods, as well as their taste characteristics and nutritional properties. The composition of organic acids varies in different food. Fruits and vegetables often contain citric acid, creatine is a unique organic acid found in meat, fermented foods have a high content of acetic acid, and seasonings have a wide range of organic acids. Determination of the organic acid contents among different food matrices allows us to monitor the sensory properties, origin identification, and quality control of foods, and further provides a basis for food formulation design. The taste characteristics and the acid taste perception mechanisms of organic acids have made some progress, and binary taste interaction is the key method to decode multiple taste perception. Real food and solution models elucidated that the organic acid has an asymmetric interaction effect on the other four basic taste attributes. In addition, in terms of nutrition and health, organic acids can provide energy and metabolism regulation to protect the human immune and myocardial systems. Moreover, it also exhibited bacterial inhibition by disrupting the internal balance of bacteria and inhibiting enzyme activity. It is of great significance to clarify the synergistic dose-effect relationship between organic acids and other taste sensations and further promote the application of organic acids in food salt reduction.

Identification and Inhibition of the Key Off-Odorants in Duck Broth by Means of the Sensomics Approach and Binary Odor Mixture

To improve the sensory quality and promote the diversified development of duck meat, the identification and inhibition of key off-odorants in duck broth were comparatively characterized by using the sensomics approach and binary odor mixture analysis. Sensory evaluation results showed that Litsea pungens Hemsl (LPH) could strongly inhibit the duck broth off-odorants. Fifty-four aroma-active compounds with flavor dilution factors ranging from 1 to 2048 were identified in duck broth and duck broth stewed by LPH. Recombination and omission tests confirmed that trans-4,5-epoxy-(E)-2-decenal, (E)-2-octenal, p-cresol, 1-octen-3-ol, and 4-methyloctanoic acid were the key off-odorants in duck broth. Additionally, trans-4,5-epoxy-(E)-2-decenal (9.26 μg/L) and p-cresol (718.91 μg/L) were identified as the key off-odorants in duck meat for the first time. The results of binary odor mixture and off-odorants inhibition curves demonstrated that linalool with the lowest theoretical inhibitory concentration (109.65 μg/L) had the best aroma masking ability among the five off-odorants, followed by geraniol (123.03 μg/L), (Z)-3,7-dimethyl-2,6-octadien-1-ol (301.99 μg/L), (E)-3,7-dimethyl-2,6-octadienal (2187.76 μg/L), and (Z)-3,7-dimethyl-2,6-octadienal (2691.53 μg/L). The spiking test verified that these compounds with the lowest theoretical inhibitory concentrations effectively inhibited the off-odorants of duck broth.

Recent trends in aroma release and perception during food oral processing: A review

The dynamic and complex peculiarities of the oral environment present several challenges for controlling the aroma release during food consumption. They also pose higher requirements for designing food with better sensory quality. This requires a comprehensive understanding of the basic rules of aroma transmission and aroma perception during food oral processing and its behind mechanism. This review summarized the latest developments in aroma release from food to retronasal cavity, aroma release and delivery influencing factors, aroma perception mechanisms. The individual variance is the most important factor affecting aroma release and perception. Therefore, the intelligent chewing simulator is the key to establish a standard analytical method. The key odorants perceived from the retronasal cavity should be given more attention during food oral processing. Identification of the olfactory receptor activated by specific odorants and its binding mechanisms are still the bottleneck. Electrophysiology and image technology are the new noninvasive technologies in elucidating the brain signals among multisensory, which can fill the gap between aroma perception and other senses. Moreover, it is necessary to develop a new approach to integrate the relationship among aroma binding parameters, aroma concentration, aroma attributes and cross-modal reactions to make the aroma prediction model more accurate.

The Effect of Prickly Ash (Zanthoxylum bungeanum Maxim) on the Taste Perception of Stewed Sheep Tail Fat by LC-QTOF-MS/MS and a Chemometrics Analysis

This work aims to explore the contribution of prickly ash (Zanthoxylum bungeanum Maxim) on the taste perception of stewed sheep tail fat. Liquid chromatography-tandem quadrupole time of flight mass spectrometry (LC-QTOF-MS) was applied to analyze the taste-related compounds. A total of 99 compounds in different sheep tail fat samples were identified. The semi-quantitative results showed that there were differences between the samples. The partial least squares discriminant analysis (PLS-DA) model without overfitting was used to investigate the effect of prickly ash. Eleven marker compounds were predicted with a variable importance for projection > 1, fold change > 2 and p < 0.05. An additional experiment showed that guanosine 5'-monophosphate, malic acid, inosine and adenosine 5'-monophosphate could improve the umami and saltiness taste of stewed sheep tail fat.

circRNA expression patterns and circRNA-miRNA-mRNA networks during CV-A16 infection of SH-SY5Y cells

Coxsackievirus A16 (CV-A16) has caused worldwide epidemics of hand, foot, and mouth disease (HFMD) in infants and preschool children. Circular RNAs (circRNAs), a class of noncoding RNA molecules, participate in the progression of viral infectious diseases. Although the function of circRNAs has been a heavily researched topic, their role in CV-A16 infection is still unclear. In this study, the viral effects of CV-A16 on the cellular circRNA transcriptome were investigated using next-generation sequencing technology. The results showed that a total of 8726, 8611, and 6826 circRNAs were identified at 0, 12, and 24 h postinfection, respectively. Moreover, it was found that 1769 and 1192 circRNAs were differentially expressed in at 12 and 24 h postinfection, respectively. The common differentially expressed circRNAs were used for functional annotation analysis, and it was found that the parent genes of differentially expressed circRNAs might be associated with the viral infection process, especially the “Immune system process” in GO analysis and the “Inflammation mediated by chemokine and cytokine signaling pathway” in KEGG analysis. Subsequently, circRNA-miRNA-mRNA regulatory networks were constructed, and the hsa_circ_0004447/hsa-miR-942-5p/MMP2, hsa_circ_0078617/hsa-miR-6780b-5p/MMP2 and hsa_circ_0078617/hsa-miR-5196-5p/MMP2 regulatory axes were identified by enrichment analysis as important networks during the progression of CV-A16 infection. Finally, six dysregulated circRNAs were selected for validation and were verified to be consistent with the sequencing results. Considering all of these results, to the best of our knowledge, this study is the first to present a comprehensive overview of circRNAs induced by CV-A16 infection, and this research demonstrated that a network of enriched circRNAs and circRNA-associated competitive endogenous RNAs (ceRNAs) is involved in the regulation of CV-A16 infection, thereby helping to elucidate the mechanisms underlying CV-A16-host interactions.

Analysis of the MCL-1 gene in Chinese women with idiopathic premature ovarian insufficiency

OBJECTIVE

Animal studies have demonstrated that myeloid cell leukemia-1 (Mcl-1) gene deficiency leads to premature ovarian failure and decreased reproductive ability in mice. This study investigated the relationship between MCL-1 gene variation and idiopathic premature ovarian insufficiency (POI) in Chinese women.

METHODS

A total of 200 idiopathic POI patients and 100 healthy controls were recruited for this study, and peripheral blood was collected. First, genomic DNA was extracted from peripheral leukocytes. Then, the entire coding region and splice sites of the MCL-1 gene were amplified by polymerase chain reaction. Chi-squared tests were used to compare the genotype distribution and allele frequency of single nucleotide polymorphisms between the POI and control groups.

RESULTS

Three mutations of the MCL-1 gene (c.-36C > T, c.-131C > T and c.78C > T) were identified. After data analysis, c.-36C > T and c.-131C > T in the 5'-untranslated region were both found in the POI group and the control group. No difference was found in the genotype distribution or allelic frequency of either variant between the POI group and the control group (p > 0.05). The synonymous variant (c.78C > T) in exon 1 was discovered in only one of the control subjects and did not result in a change in amino acid sequence (p.Gly26Gly).

CONCLUSION

MCL-1 gene mutation may not be associated with idiopathic POI in Chinese women.

Simultaneous detection of fetal aneuploidy, de novo FGFR3 mutations and paternally derived β-thalassemia by a novel method of noninvasive prenatal testing

OBJECTIVE

The aim is to develop a novel noninvasive prenatal testing (NIPT) method that simultaneously performs fetal aneuploidy screening and the detection of de novo and paternally derived mutations.

METHODS

A total of 68 pregnancies, including 26 normal pregnancies, 7 cases with fetal aneuploidies, 7 cases with fetal achondroplasia or thanatophoric dysplasia, 18 cases with fetal skeletal abnormalities, and 10 cases with β-thalassemia high risk were recruited. Plasma cell-free DNA was amplified by Targeted And Genome-wide simultaneous sequencing (TAGs-seq) to generate around 99% of total reads covering the whole-genome region and around 1%  covering the target genes. The reads on the whole-genome region were analyzed for fetal aneuploidy using a binary hypothesis T-score and the reads on target genes were analyzed for point mutations by calculating the minor allelic frequency of loci on FGFR3 and HBB. TAGs-seq results were compared with conventional NIPT and diagnostic results.

RESULTS

In each sample, TAGs-seq generated 44.7-54 million sequencing reads covering the whole-genome region of 0.1-3× and the target genes of >1000×depth. All cases of fetal aneuploidy and de novo mutations of achondroplasia/thanatophoric dysplasia were identified with high sensitivities and specificities except for one false-negative paternal mutation of β-thalassemia.

CONCLUSIONS

TAGs-seq is a novel NIPT method that combines the fetal aneuploidy screening and the detection of de novo FGFR3 mutations and paternal HBB mutations.

Kinetics of α‑dicarbonyl compounds formation in glucose-glutamic acid model of Maillard reaction

As a potential health hazard, α-dicarbonyl compounds have been detected in the thermally processed foods. In order to investigate the formation kinetics of α-dicarbonyl compounds, liquid chromatography-electrospray tandem mass spectrometry was employed to determine the content of α-dicarbonyl compounds in glucose-only and glucose-glutamic acid (glucose-Glu) thermal reaction models. The 3-deoxyglucosone content was significantly higher than 6 α-dicarbonyl compounds at 90-110℃, 0-6 hr in the two tested systems. The glutamic acid promoted the content accumulation of 1-deoxyglucosone, diacetyl, methylglyoxal, and glyoxal, whereas inhibited the content of 3-deoxyglucosone and 3,4-dideoxyglucosone. Three-fifths of the tested compounds content increased linearly with time increasing, but in glucose-only system, the 1-deoxyglucosone content increased logarithmically at 95-110℃ over reaction time. The formation of glucose (100-110℃, glucose-only and glucose-Glu), 5-hydroxymethylfurfural (100-110℃, glucose-only), 1-deoxyglucose (105-110℃, glucose-Glu), 3,4-dideoxyglucosone (110℃, glucose-Glu), glyoxal (95-110℃, glucose-Glu) and diacetyl (90-95℃, glucose-Glu) could be well fitted by exponential equation. Shortening the heating time and reducing heating temperature (except glyoxal in glucose-only system) were the effective methods to decrease α-dicarbonyl compounds content in the two tested systems. Additionally, high temperature could also reduce α-dicarbonyl compounds content, such as 3-deoxyglucosone (≥110℃, glucose-only), 1-deoxyglucosone (≥110℃, glucose-only), glucosone (≥110℃, glucose-only; ≥100℃, glucose-Glu), methyloxyl (≥110℃, glucose-only; ≥100℃, glucose-Glu), diacetyl (≥110℃, glucose-only), and glyoxal (≥100℃, glucose-Glu).

Characterization of the dynamic texture perception and the impact factors on the bolus texture changes during oral processing

The purpose of this work was to characterize the dynamic texture perception and study the mechanisms occurring in bolus from chewing to swallowing during white bread oral processing. Results indicated that the microstructural and chemical composition properties determined the oral processing behaviors. At the initial stage of oral processing, the roughness, hardness, and dryness perception were the dominant attributes. At the end of oral processing the adhesiveness and softness perception were dominant, which correlated to the higher bolus water content and adhesive properties. The softness and adhesiveness perception were the key factors that trigger swallowing. In vitro artificial mastication experiments confirmed that mucin rapidly increased the adhesive force of bolus at the initial stage of oral processing, whereas α-amylase gradually increased the adhesive force. These results can help to better understand the dynamic texture perception and its change mechanisms during oral processing.

Characterization of the key odorants contributing to retronasal olfaction during bread consumption

Gas chromatography-ion mobility spectrometry (GC-IMS) and dynamic quantitative descriptive analysis (D-QDA) were combined to explore the aroma release and perception from the retronasal cavity during bread consumption. D-QDA results elucidated that the sweet, creamy, and roasty notes were the most active attributes during oral processing. The final stage of oral processing had the most complicated changing pattern, followed by the intermediate and initial stages. Thirteen aroma compounds were detected in the retronasal cavity, of which eight had odor activity values (OAVs) greater than 1. The total OAV changing pattern was consistent with the D-QDA results. Addition experiments further confirmed that acetoin, 2,3-butanedione, and 3-(methylthio)propanal were key aroma compounds contributing to retronasal olfaction. 2,3-Butanedione and 3-(methylthio)propanal were both identified as key odorants in the mouth cavity and retronasal cavity during oral processing, but they had 30% loss during the breath delivery from the mouth cavity to the retronasal cavity.

Evaluation of CD4+CD25+FOXP3+ regulatory T cells and FOXP3 mRNA in premature ovarian insufficiency

Objective: T cell-mediated injury plays an important role in the pathogenesis of autoimmune premature ovarian insufficiency (POI). The purpose of this study was to assess the percentage of CD4⁺CD25⁺FOXP3⁺ regulatory T (Treg) cells and the level of forkhead box protein 3 (FOXP3) mRNA expression in POI patients.Methods: The case-control study compared 30 POI patients with 30 healthy subjects. Peripheral blood mononuclear cells were collected. The percentage of CD4⁺CD25⁺FOXP3⁺ Treg cells was measured by flow cytometry using specific monoclonal antibodies recognizing the CD4⁺, CD25⁺, and FOXP3⁺ markers. FOXP3 gene expression was evaluated by real-time polymerase chain reaction. In addition, the levels of transforming growth factor-β1 (TGF-β1), interferon-γ (IFN-γ), and adrenal cortex autoantibody (AAA) were determined by enzyme-linked immunosorbent assay.Results: The percentage of CD4⁺CD25⁺FOXP3⁺ Treg cells and the level of FOXP3 mRNA expression were significantly decreased in the POI patients compared with the control subjects. Moreover, the women with POI showed significantly increased levels of IFN-γ and AAA but reduced levels of TGF-β1.Conclusions: Our study suggested that POI may be associated with an abrogated function of circulating CD4⁺CD25⁺FOXP3⁺ Treg cells and a decreased level of FOXP3 gene expression. However, these results require further investigation.

Detection of fetal trisomy and single gene disease by massively parallel sequencing of extracellular vesicle DNA in maternal plasma: a proof-of-concept validation

BACKGROUND

During human pregnancy, placental trophectoderm cells release extracellular vesicles (EVs) into maternal circulation. Trophoblasts also give rise to cell-free DNA (cfDNA) in maternal blood, and has been used for noninvasive prenatal screening for chromosomal aneuploidy. We intended to prove the existence of DNA in the EVs (evDNA) of maternal blood, and compared evDNA with plasma cfDNA in terms of genome distribution, fragment length, and the possibility of detecting genetic diseases.

METHODS

Maternal blood from 20 euploid pregnancies, 9 T21 pregnancies, 3 T18 pregnancies, 1 T13 pregnancy, and 2 pregnancies with FGFR3 mutations were obtained. EVs were separated from maternal plasma, and confirmed by transmission electronic microscopy (TEM), western blotting, and flow cytometry (FACS). evDNA was extracted and its fetal origin was confirmed by quantitative PCR (qPCR). Pair-end (PE) whole genome sequencing was performed to characterize evDNA, and the results were compared with that of cfDNA. The fetal risk of aneuploidy and monogenic diseases was analyzed using the evDNA sequencing data.

RESULTS

EVs separated from maternal plasma were confirmed with morphology by TEM, and protein markers of CD9, CD63, CD81 as well as the placental specific protein placental alkaline phosphatase (PLAP) were confirmed by western blotting or flow cytometry. EvDNA could be successfully extracted for qPCR and sequencing from the plasma EVs. Sequencing data showed that evDNA span on all 23 pairs of chromosomes and mitochondria, sharing a similar distribution pattern and higher GC content comparing with cfDNA. EvDNA showed shorter fragments yet lower fetal fraction than cfDNA. EvDNA could be used to correctly determine fetal gender, trisomies, and de novo FGFR3 mutations.

CONCLUSIONS

We proved that fetal DNA could be detected in EVs separated from maternal plasma. EvDNA shared some similar features to plasma cfDNA, and could potentially be used to detect genetic diseases in fetus.

Characterization of the aroma release and perception of white bread during oral processing by gas chromatography-ion mobility spectrometry and temporal dominance of sensations analysis

The purpose of this study was to investigate the aroma release and perception from white bread during oral processing by gas chromatography-ion mobility spectrometry (GC-IMS) and dynamic sensory evaluation of temporal dominance of sensations (TDS). TDS curves indicated that two maximum aroma perception signals, fermentation-like and flour-like attributes, were perceived at the beginning and swallowing, respectively. The fermentation-like, flour-like, and sour attributes were the 3 dominant aromas during oral processing. A total of 35 volatile compounds were detected in the mouth cavity during chewing white bread, 19 of them were confirmed and quantified by using the respective external standard. Based on PLSR analysis, 8 aroma compounds were predicted as potent odorants contributing to the aroma perception from chewing white bread. By application of odor activity values analysis and addition experiments, ethyl butanoate, butyl acetate, hexanal, 3-(methylthio)-propanal, 3-methylbutanal, and 2,3-butanedione were confirmed as the key odorants contributing to the aroma perception during chewing of white bread.

Increased CD4+CD25-Foxp3+ T cells in Chinese systemic lupus erythematosus: correlate with disease activity and organ involvement

Objective

The increment of CD4+CD25−Foxp3+T cells has been reported in systemic lupus erythematosus (SLE) patients. However, the exact identity of this T cell subset is still unclear. Thus, we analyzed CD4+CD25−Foxp3+T cells and Treg cells (CD4+CD25+Foxp3+ T cells) in a large sample of Chinese SLE patients in different disease states.

Methods

A total of 280 SLE patients and 38 healthy volunteers were enrolled, which included 21 patients with untreated new-onset lupus (UNOL), 13 patients with drug withdrawal more than 6 months and 246 patients with treatments. Phenotypic and functional analysis of peripheral blood CD4+CD25−Foxp3+ T cells and Treg cells were performed by flow cytometry. The correlation of CD4+CD25−Foxp3+T cells and Treg cells with disease activity, clinical indicators and organ involvement were analyzed.

Results

CD4+CD25−Foxp3+ T cells and Treg cells were significantly increased in SLE patients and showed significantly positive correlations with disease activity. CD4+CD25−Foxp3+ T cells were significantly increased in patients with skin and hematologic involvement as well as arthritis. Diverse changes between CD4+CD25−Foxp3+ T cells and Treg cells when faced with different medications, especially HCQ and MMF. CD4+CD25−Foxp3+ T cells expressed more IFN-γ and less CTLA-4 than CD4+CD25+Foxp3+ T cells, which were similar to CD4+CD25+Foxp3− T cells, and expressed similar IL-17, ICOS and Helios to CD4+CD25+Foxp3+ T cells. The synthesis capacity of IL-10 of CD4+CD25−Foxp3+ T cells and the expression of GITR on CD4+CD25−Foxp3+ T cells were between CD4+CD25+Foxp3+ and CD4+CD25+Foxp3− T cells.

Conclusions

Our results indicate that increased CD4+CD25−Foxp3+ T cells in lupus patients, which combined the features of suppression and pro-inflammatory, may serve as a biomarker for disease activity and organ involvement in SLE.

Characterization and comparison of key aroma compounds in raw and dry porcini mushroom (Boletus edulis) by aroma extract dilution analysis, quantitation and aroma recombination experiments

A study was carried out to determine and compare the key aroma compounds in raw and dry porcini mushroom (Boletus edulis). The volatile fractions were prepared by solvent-assisted flavor evaporation (SAFE), and aroma extract dilution analysis (AEDA) combined with gas chromatography-mass spectrometry (GC-MS) was employed to identify the odorants. Selected aroma compounds were quantitated and odor activity values (OAVs) were calculated revealing OAVs ≥ 1 for 12 compounds in raw porcini, among which 1-octen-3-one showed the highest OAV. In addition to compounds with eight carbon atoms, 3-methylbutanal, (E,E)-2,4-decadienal and (E,E)-2,4-nonadienal were also responsible for the unique aroma profile. In dry mushroom OAVs ≥ 1 were obtained for 20 odorants. Among them, 3-(methylthio)propanal, 1-octen-3-one and pyrazines were determined as predominant odorants. Overall, drying increased complexity of volatile compounds, thus significantly changing the aroma profile of porcini, providing more desirable roasted and seasoning-like flavor and less grass-like and earthy notes.

Analysis of the Comprehensive Tensile Relationship in Electrospun Silk Fibroin/Polycaprolactone Nanofiber Membranes

The mechanical properties of electrospun nanofiber membranes are critical for their applications. A clear understanding of the mechanical properties that result from the characteristics of the individual fiber and membrane microstructure is vital in the design of fiber composites. In this reported study, silk fibroin (SF)/polycaprolactone (PCL) composite nanofiber membranes were preparedusing an electrostatic spinning technology. The nanofiber orientation distribution (FOD) of the membrane was analyzed using multi-layer image fusion technology, and the results indicated the presence of an approximately uniform distribution of fibers in the electrospun membranes. The relationship between the single nanofiber and the membrane was established by analyzing the geometrical structure of the cell by employing a representative volume element (RVE) analysis method. The mechanical properties of the 272 nm diameter SF/PCL composite fibers were then predicted using the developed model.

Metabolic syndrome in menopause and associated factors: a meta-analysis

OBJECTIVE

Metabolic syndrome (MetS) is a cluster of risk factors for cardiovascular disease and diabetes. Menopause is associated with an increased risk for MetS. The purpose of this meta-analysis is to better understand the relationship between MetS and menopause.

METHODS

MEDLINE and EMBASE were searched for all the associated articles on (1) MetS components in postmenopausal women vs. premenopausal women, (2) comparison of MetS incidence between surgical menopause and natural menopause, (3) the effect of hormone therapy (HT) with 17β-estradiol (E2) compared to conjugated equine estrogen (CEE) on MetS components among postmenopausal women. A meta-analysis was applied by Review Manager 5.3 software.

RESULTS

All comparable indicators were significantly unfavorably changed in postmenopausal women compared to premenopausal women except for high density lipoprotein cholesterol. Women who underwent surgical menopause suffered a 1.51-fold higher risk for MetS compared to those with natural menopause. HT with E2 provided more benefits for levels of triglyceride and diastolic blood, while CEE showed a better effect on both high and low density lipoprotein cholesterol levels.

CONCLUSIONS

Menopause nearly adversely affects all components of MetS, and surgical menopause may lead to a higher incidence of MetS compared to natural menopause. HT with various preparations may have different effects on MetS components. These results may clarify the management of menopause-related MetS in clinical practice.

Association analysis between HFM1 variation and primary ovarian insufficiency in Chinese women

HFM1 is a meiosis-specific gene and expressed in germ-line tissues. More recently, evidence has indicated that variations in HFM1 gene could be causative for primary ovarian insufficiency (POI), also known as premature ovarian failure. The aim of this study was to investigate the association between HFM1 gene variants and sporadic POI in Chinese women. A total of 138 POI patients and 316 healthy controls (matched for ethnic background, sex, and age of the patients) were recruited in this study. We screened the entire HFM1 coding region by direct sequencing in all subjects and identified six variants of HFM1 gene in POI group, namely c.148G>A/p.Glu50Lys, c.1241A>C/p.His414Pro, c.2325C>A/p.Phe775Leu, c.3367T>C/p.Ser1123Pro, c.3580C>T/p.Arg1194Cys, and c.1686-1G>C. The variation rate of HFM1 in POI group is significantly higher than control group (p < 0.01). The p.His414Pro and p.Arg1194Cys were predicted to be probably damaging to the HFM1 protein function, while p.Glu50Lys, p.Phe775Leu and p.Ser1123Pro mutants might not have any deleterious effect on the structure or function of the protein by online predictors. Taken together, our data suggested that HFM1 gene might be associated with primary ovarian insufficiency in Chinese population.

[Study on mutations in the connexin 26 gene among Chinese with nonsyndromic hearing loss]

OBJECTIVE

To study the relation between nonsyndromic hearing loss in Chinese and mutations in connexin 26 (Cx 26) gene and to explore the pathogenic mechanism.

METHODS

One hundred and thirty-eight individuals from thirty-five pedigrees with nonsyndromic hearing loss, 99 children with sporadic nonsyndromic hearing loss and 100 normal adults as control were collected in present studies. The Cx 26 coding sequence was screened by single strand conformational polymorphism (SSCP) and analyzed by direct sequencing when SSCP shifts were observed.

RESULTS

Five SSCP shifts in 2 pedigrees were observed. Homozygous deletion C at position 233-235 of Cx 26 cDNA, which resulted in frameshift mutation, was found in 2 pedigrees with nonsyndromic hearing loss.

CONCLUSION

The hot-spot mutations of Cx 26 gene in Chinese with nonsyndromic hearing loss may be different from other ethnic groups. The 233-235 delC homozygous mutation of Cx 26 cDNA can result in autosomal recessive nonsyndromic hearing loss in Chinese population.

Characterization of tetrathiofulvalene compounds using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Tetrathiofulvalene compounds are important components of charge-transfer complexes, which may be applied in various fields of scientific research and practical applications. Some of these compounds cannot be characterized by mass spectrometry. Here, matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry was used for the characterization of tetrathiofulvalenes. The samples could be easily desorbed and ionized to form singly charged ions, and mass spectra with isotopic resolution readily obtained. The mass spectrometric results for 26 compounds have shown that MALDI-TOF is more effective and convenient than other mass spectrometry methods, and resolves the problem of mass spectrometric characterization of tetrathiofulvalene compounds.

[Clinical analysis of 15 patients with primary malignant melanoma in the genital tract]

OBJECTIVE

To analyse the clinical characteristics and prognosis of primary malignant melanoma in female genital tract.

METHODS

Clinical data of 15 patients with primary malignant genital melanoma were analysed retrospectively. The tumors occurred in the vulva (4 patients), in vagina (9) and in uterine cervix (2). 11 of them were treated by surgery combined with chemotherapy and immunotherapy, the remaining 4 by chemotherapy and immunotherapy only.

RESULTS

All cases except one were followed up. The survival periods were shorter than 1 year in 5 patients, shorter than 2 years in 7. Two were alive for more than 3 years and 1 for more than 19 years.

CONCLUSIONS

The prognosis of primary malignant melanoma is rather poor. Surgery combined of chemotherapy and immunotherapy is the main therapeutic approach.