Changes In Wall Structure Research Articles

Citric Acid by-Product Fermentation by Bacillus subtilis I9: A Promising Path to Sustainable Animal Feed

Citric acid by-products in animal feed pose a sustainability challenge. Bacillus species are commonly used for fermenting and improving the nutritional quality of feedstuffs or by-products. An experiment was conducted to enhance the nutritional value of citric acid by-products through fermentation with Bacillus subtilis I9 for animal feed. The experiment was carried out in 500 mL Erlenmeyer flasks with 50 g of substrate and 200 mL of sterile water. Groups were either uninoculated or inoculated with B. subtilis I9 at 107 CFU/mL. Incubation occurred at 37 °C with automatic shaking at 150 rpm under aerobic conditions for 0, 24, 48, 72, and 96 h. Inoculation with B. subtilis I9 significantly increased Bacillus density to 9.3 log CFU/mL at 24 h (p < 0.05). CMCase activity gradually increased, reaching a maximum of 9.77 U/mL at 72 h. After 96 h of fermentation with inoculated B. subtilis I9, the citric acid by-product exhibited a significant decrease (p < 0.05) in crude fiber by 10.86%, hemicellulose by 20.23%, and cellulose by 5.98%, but an increase in crude protein by 21.89%. Gross energy decreased by 4% after inoculation with B. subtilis in comparison to the uninoculated control (p < 0.05). Additionally, the non-starch polysaccharide (NSP) degradation due to inoculation with B. subtilis I9 significantly reduced (p < 0.05) NSP by 24.37%, while galactose, glucose, and uronic acid decreased by 22.53%, 32.21%, and 18.11%, respectively. Amino acid profile content increased significantly by more than 12% (p < 0.05), including indispensable amino acids such as histidine, isoleucine, lysine, methionine, phenylalanine, tryptophan, and valine and dispensable amino acids like alanine, aspartic acid, glutamic acid, glutamine, glycine, proline, and tyrosine. Furthermore, citric acid by-products inoculated with B. subtilis I9 exhibited changes in the cell wall structure under scanning electron microscopy, including fragmentation and cracking. These results suggest that fermenting citric acid by-products with B. subtilis I9 effectively reduces dietary fiber content and improves the nutritional characteristics of citric acid by-products for use in animal feed.

Function Analysis of a Maize Endo-1,4-β-xylanase Gene ZmHSL in Response to High-Temperature Stress.

Rising temperature is a major threat to the normal growth and development of maize, resulting in low yield production and quality. The mechanism of maize in response to heat stress remains uncertain. In this study, a maize mutant Zmhsl-1 (heat sensitive leaves) with wilting and curling leaves under high temperatures was identified from maize Zheng 58 (Z58) mutant lines generated by ethyl methanesulfonate (EMS) mutagenesis. The Zmhsl-1 plants were more sensitive to increased temperature than Z58 in the field during growth season. The Zmhsl-1 plants had lower plant height, lower yield, and lower content of photosynthetic pigments. A bulked segregant analysis coupled with whole-genome sequencing (BSA-seq) enabled the identification of the corresponding gene, named ZmHSL, which encodes an endo-β-1,4-xylanase from the GH10 family. The loss-of-function of ZmHSL resulted in reduced lignin content in Zmhsl-1 plants, leading to defects in water transport and more severe leaf wilting with the increase in temperature. RNA-seq analysis revealed that the differentially expressed genes identified between Z58 and Zmhsl-1 plants are mainly related to heat stress-responsive genes and unfolded protein response genes. All these data indicated that ZmHSL plays a key role in lignin synthesis, and its defective mutation causes changes in the cell wall structure and gene expression patterns, which impedes water transport and confers higher sensitivity to high-temperature stress.

Ultrasound detection of non-atherosclerotic intima-medial abnormalities of lower limbs arteries in amateur endurance runners

BackgroundStructural changes in the lower limb’s arterial wall in amateur endurance runners are a rare incidental finding, represented just by several case reports.AimStudy the incidence of non-atherosclerotic lower limb artery wall changes in defined group of amateur endurance runners and identify relationship with the training parameters and the relevant biochemical markers.MethodsAmateur male athletes engaged in endurance running for more than 5 years were enrolled. Tibial and anterior popliteal arteries on each side were examined by ultrasound with focus on non-atherosclerotic structural wall changes: intima-medial border blurring, presence and character of non-atherosclerotic noduli. Subsequently the descriptive and correlation analysis were performed.ResultsThe study enrolled 20 amateur male endurance runners from Black Swan Triathlon Club Slovakia. The low atherosclerotic risk was represented by normal lipid levels, BMI under 30 kg/m2 and non-smokers in all participants. At least one type of structural artery wall abnormality (noduli or intima-medial border blurring) was present in 19 of 20 participants (95%). The most present was the intima-medial blurring. (80% of participants). The noduli were present in 65% of study group, in almost 40% of these, they were considered as hyperechogenic. All these affections were predominantly in popliteal artery area (65%). The vast majority has bilateral affection. We find a mild correlation between these ultrasound findings and training load represented by annual kilometers and run hours. There was no association between these changes and lipid spectrum or CRP level.ConclusionThe subclinical lower limb artery changes, represented by intima-medial border blurring and non-atherosclerotic noduli were present in almost every amateur endurance runner. Despite the underlying mechanism is not understood, the increased training load seems to be one of the responsible factors.

Spectroscopic Investigation of Tomato Seed Germination Stimulated by Trichoderma spp.

Seed germination is a complex process that can be negatively affected by numerous stresses. Trichoderma spp. are known as effective biocontrol agents as well as plant growth and germination stimulators. However, understanding of the early interactions between seeds and Trichoderma spp. remains limited. In the present paper, Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy were used to reveal the nature of tomato seed germination as stimulated by Trichoderma. A rapid response of tomato seeds to Trichoderma spp. was observed within 48 h on Murashige and Skoog medium (MS) substrate, preceding any physical contact. Raman analysis indicated that both Trichoderma species stimulated phenolic compound synthesis by triggering plant-specific responses in seed radicles. The impact of T. harzianum and T. brevicompactum on two tomato cultivars resulted in alterations to the middle lamella pectin, cellulose, and xyloglucan in the primary cell wall. The Raman spectra indicated increased xylan content in NA with T9 treatment as well as increased hemicelluloses in GZ with T4 treatment. Moreover, T4 treatment resulted in elevated conjugated aldehydes in lignin in GZ, whereas the trend was reversed in NA. Additionally, FTIR analysis revealed significant changes in total protein levels in Trichoderma spp.-treated tomato seed radicles, with simultaneous decreases in pectin and/or xyloglucan. Our results indicate that two complementary spectroscopic methods, FTIR and Raman spectroscopy, can give valuable information on rapid changes in the plant cell wall structure of tomato radicles during germination stimulated by Trichoderma spp.

The different response of Brassica napus genotypes to microspore embryogenesis induced by heat shock and trichostatin A is not determined by changes in cell wall structure and composition but by different stress tolerance

AbstractDuring microspore embryogenesis, microspores are induced to develop into haploid embryos. In Brassica napus, microspore embryogenesis is induced by a heat shock (HS), which initially produces embryogenic structures with different cell wall architectures and compositions, and with different potentials to develop into embryos. The B. napus DH4079 and DH12075 genotypes have high and very low embryo yields, respectively. In DH12075, embryo yield is greatly increased by combining HS and the histone deacetylase (HDAC) inhibitor trichostatin A (TSA). However, we show that HS + TSA inhibits embryogenesis in the highly embryogenic DH4079 line. To ascertain why TSA has such different effects in these lines, we treated DH4079 and DH12075 microspore cultures with TSA and compared the cell wall structure and composition of the different embryogenic structures in both lines, specifically the in situ levels and distribution of callose, cellulose, arabinogalactan proteins and high and low methyl‐esterified pectin. For both lines, HS + TSA led to the formation of cell walls unfavorable for embryogenesis progression, with reduced levels of arabinogalactan proteins, reduced cell adhesion of inner walls and altered pectin composition. Thus, TSA effects on cell walls cannot explain their different embryogenic response to TSA. We also applied TSA to DH4079 cultures at different times and concentrations before HS application, with no negative effects on embryogenic induction. These results indicate that DH4079 microspores are hypersensitive to combined TSA and HS treatments, and open up new hypotheses about the causes of such hypersensitivity.

Cell wall water induced dimensional changes of beech and pine wood

Hygroexpansion in timber construction is a phenomenon that occurs as a result of changes in the cell wall structure of wood caused by water. In this study, beech (Fagus sylvatica) and pine (Pinus taeda L.) wood were conditioned at different relative humidities with saturated salt solutions and saturated through vacuum pressure impregnation. The moisture content and dimensions of the samples were evaluated under various adsorption equilibrium states, as well as during drying from water saturation to an air-dried state. The results obtained using the two-dimensional time-domain nuclear magnetic resonance technique revealed two distinct types of cell wall water in both wood species, designated as B-water and C-water, as they displayed different mobilities. With increasing moisture content, the mobility of cell wall water increased; however, B-water maintained a constant level of mobility and formed water clusters when it accumulated in the high humidity region and at slightly above the fiber saturation point (FSP), which is evidence of the occurrence of free-bound water. The B-water, located in the amorphous region of microfibrils and their surrounding hemicellulose, exerted a predominant influence on the dimensional changes of the wood both under equilibrium and nonequilibrium conditions, in comparison to the C-water which located in the matrix of hemicellulose and lignin.

Studies on the mechanism of the contact toxicity of carvone against Tribolium castaneum

Carvone exhibits significant insecticidal activity against Tribolium castaneum. Whereas, the precise underlying mechanism of carvone's toxicity remains elusive. In this study, we aimed to investigate the contact toxicity mechanism of carvone on T. castaneum through a comprehensive set of experiments. These experiments included observation of poisoning symptoms in T. castaneum, a time-mortality test, analysis of weight measurement and respiration activities, histological assessment, enzymatic assays, and molecular simulation studies. Physiological analyses show that carvone induces excitement, spasms, and a comatose state in T. castaneum, accompanied by darkening of the body surface. Survival rates significantly dropped by 44% after 8–12 h of carvone treatment. Carvone also affects metabolism, increasing CO2 release and body weight loss. Histopathological examination reveals changes in the body wall structure, including wax particle shape alterations, increased gaps, and damaged hair bases. Abdominal tissue examination shows impacts on muscle and fat tissues, leading to dehydration and impaired physiological functions. Key enzymatic assays demonstrate sustained inhibition of acetylcholinesterase and succinate dehydrogenase activity by carvone, with peak inhibition rates reaching 65.15% and 39.90%, respectively. Carvone exhibits a biphasic effect on ATPases and activates glutathione S-transferase while inhibiting carboxylesterase activity. Molecular docking analysis reveals direct interactions between carvone and acetylcholinesterase in T. castaneum, suggesting its inhibition mechanism. This study provides insights into the insecticidal mechanism of carvone on T. castaneum and contributes to the development of plant-based insecticides.

Cardiac Magnetic Resonance Studies in a Large Animal Model that Simulates the Cardiac Abnormalities of Human Septic Shock.

Septic shock, in humans and in our well-established animal model, is associated with increases in biventricular end diastolic volume (EDV) and decreases in ejection fraction (EF). These abnormalities occur over 2 days and reverse within 10 days. Septic non-survivors do not develop an increase in EDV. The mechanism for this cardiac dysfunction and EDV differences is unknown. Purpose-bred beagles randomized to receive intrabronchial Staphylococcus aureus (n=27) or saline (n=6) were provided standard ICU care including sedation, mechanical ventilation, and fluid resuscitation to a pulmonary arterial occlusion pressure of over 10mmHg. No catecholamines were administered. Over 96h, cardiac magnetic resonance imaging, echocardiograms, and invasive hemodynamics were serially performed, and laboratory data was collected. Tissue was obtained at 66h from six septic animals. From 0-96h after bacterial challenge, septic animals vs. controls had significantly increased left ventricular wall edema (6%) and wall thinning with loss of mass (15%) which was more pronounced at 48h in non-survivors than survivors. On histology, edema was located predominantly in myocytes, the interstitium, and endothelial cells. Edema was associated with significantly worse biventricular function (lower EFs), ventricular-arterial coupling, and circumferential strain. In septic animals, from 0-24h, the EDV decreased from baseline and, despite cardiac filling pressures being similar, decreased significantly more in non-survivors. From 24-48h, all septic animals had increases in biventricular chamber sizes. Survivors biventricular EDVs were significantly greater than baseline and in non-survivors, where biventricular EDVs were not different from baseline. Preload, afterload, or HR differences did not explain these differential serial changes in chamber size. Systolic and diastolic cardiac dysfunction during sepsis is associated with ventricular wall edema. Rather than differences in preload, afterload, or heart rate, structural alterations to the ventricular wall best account for the volume changes associated with outcome during sepsis. In non-survivors, from 0-24h, sepsis induces a more severe diastolic dysfunction, further decreasing chamber size. The loss of left ventricular mass with wall thinning in septic survivors may, in part explain, the EDV increases from 24-48h. However, these changes continued and even accelerated into the recovery phase consistent with a reparative process rather than ongoing injury.

Physicochemical structure and micromechanical properties of archaeological wood under alternating dry and wet conditions

ABSTRACT The relationship between physicochemical structure and micromechanical properties of archaeological wood is not understand. For this purpose, the study took the archaeological wood from the Shahe Ancient Bridge site as an example. The physical properties, microstructure, chemical composition, and micromechanics of archaeological wood were evaluated using non-destructive and micro-destructive techniques. The results indicated that the deterioration of Phoebe sp. wood was more severe than that of Abies sp. wood. However, the basic density of Phoebe sp. wood was higher than that of the control sample due to the collapse of cell walls. The cell walls exhibited a variety of destructional forms, such as cavities and collapses, caused by decay fungi and erosion bacteria. The cell cavities and cell walls deposited inorganic substances. Furthermore, hemicellulose and amorphous cellulose were preferentially degraded before crystalline cellulose was degraded, and S-type lignin was more prone to degradation compared to G-type lignin. Due to the changes of cell wall structure, the hardness of the cell walls increased while the elastic modulus of the cell wall decreased significantly. This study may provide a reference for the study of the relationship between cell wall structure and micromechanics of archaeological wood.

Restraining Quiescence Release-Related Ageing in Plant Cells: A Case Study in Carrot.

The blackening of cut carrots causes substantial economic losses to the food industry. Blackening was not observed in carrots that had been stored underground for less than a year, but the susceptibility to blackening increased with the age of the carrots that were stored underground for longer periods. Samples of black, border, and orange tissues from processed carrot batons and slices, prepared under industry standard conditions, were analyzed to identify the molecular and metabolic mechanisms underpinning processing-induced blackening. The black tissues showed substantial molecular and metabolic rewiring and large changes in the cell wall structure, with a decreased abundance of xyloglucan, pectins (homogalacturonan, rhamnogalacturonan-I, galactan and arabinan), and higher levels of lignin and other phenolic compounds when compared to orange tissues. Metabolite profiling analysis showed that there was a major shift from primary to secondary metabolism in the black tissues, which were depleted in sugars, amino acids, and tricarboxylic acid (TCA) cycle intermediates but were rich in phenolic compounds. These findings suggest that processing triggers a release from quiescence. Transcripts encoding proteins associated with secondary metabolism were less abundant in the black tissues, but there were no increases in transcripts associated with oxidative stress responses, programmed cell death, or senescence. We conclude that restraining quiescence release alters cell wall metabolism and composition, particularly regarding pectin composition, in a manner that increases susceptibility to blackening upon processing.

Simultaneous suppression of lignin, tricin and wall-bound phenolic biosynthesis via the expression of monolignol 4-O-methyltransferases in rice.

Grass lignocelluloses feature complex compositions and structures. In addition to the presence of conventional lignin units from monolignols, acylated monolignols and flavonoid tricin also incorporate into lignin polymer; moreover, hydroxycinnamates, particularly ferulate, cross-link arabinoxylan chains with each other and/or with lignin polymers. These structural complexities make grass lignocellulosics difficult to optimize for effective agro-industrial applications. In the present study, we assess the applications of two engineered monolignol 4-O-methyltransferases (MOMTs) in modifying rice lignocellulosic properties. Two MOMTs confer regiospecific para-methylation of monolignols but with different catalytic preferences. The expression of MOMTs in rice resulted in differential but drastic suppression of lignin deposition, showing more than 50% decrease in guaiacyl lignin and up to an 90% reduction in syringyl lignin in transgenic lines. Moreover, the levels of arabinoxylan-bound ferulate were reduced by up to 50%, and the levels of tricin in lignin fraction were also substantially reduced. Concomitantly, up to 11 μmol/g of the methanol-extractable 4-O-methylated ferulic acid and 5-7 μmol/g 4-O-methylated sinapic acid were accumulated in MOMT transgenic lines. Both MOMTs in vitro displayed discernible substrate promiscuity towards a range of phenolics in addition to the dominant substrate monolignols, which partially explains their broad effects on grass phenolic biosynthesis. The cell wall structural and compositional changes resulted in up to 30% increase in saccharification yield of the de-starched rice straw biomass after diluted acid-pretreatment. These results demonstrate an effective strategy to tailor complex grass cell walls to generate improved cellulosic feedstocks for the fermentable sugar-based production of biofuel and bio-chemicals.

The Resistance of Maize to Ustilago maydis Infection Is Correlated with the Degree of Methyl Esterification of Pectin in the Cell Wall.

Common smut caused by Ustilago maydis is one of the dominant fungal diseases in plants. The resistance mechanism to U. maydis infection involving alterations in the cell wall is poorly studied. In this study, the resistant single segment substitution line (SSSL) R445 and its susceptible recurrent parent line Ye478 of maize were infected with U. maydis, and the changes in cell wall components and structure were studied at 0, 2, 4, 8, and 12 days postinfection. In R445 and Ye478, the contents of cellulose, hemicellulose, pectin, and lignin increased by varying degrees, and pectin methylesterase (PME) activity increased. The changes in hemicellulose and pectin in the cell wall after U. maydis infection were analyzed via immunolabeling using monoclonal antibodies against hemicellulsic xylans and high/low-methylated pectin. U. maydis infection altered methyl esterification of pectin, and the degree of methyl esterification was correlated with the resistance of maize to U. maydis. Furthermore, the relationship between methyl esterification of pectin and host resistance was validated using 15 maize inbred lines with different resistance levels. The results revealed that cell wall components, particularly pectin, were important factors affecting the colonization and propagation of U. maydis in maize, and methyl esterification of pectin played a role in the resistance of maize to U. maydis infection.

Effect of heating of pea fibres on their swelling, rheological properties and in vitro colon fermentation

Dietary fibre intake is essential for all human beings and has been correlated to beneficial health effects. Pea hull fibres (PF) are generally seen as a side stream during extraction of protein and starch from yellow pea but could be used in various food products to boost fibre content. In this study, the thermal treatment of pea hull fibres was investigated in terms of physicochemical properties and in vitro colonic fermentation. The PF that was subjected to heating showed an increase of fibres solubilised in the liquid and particle size. Results also showed that viscosity and storage modulus increased with thermal treatment, possibly due to the swelling of the PF. The pea fibre was readily fermentable based on total gas production and pH. However, the susceptibility to fermentation of PF did not increase with thermal treatment. Total gas production and short chain fatty acid produced were similar independent of thermal treatment. Conclusively, heating of the PF resulted in increased ability to structure water suspension, owing to increased fibre particle size, but is not sufficient to increase short chain fatty acid production during colonic fermentation. To explain this, we propose that the changes in cell wall structure were not major enough to induce higher fermentability.

The efficient activity of plant essential oils for inhibiting Botrytis cinerea and Penicillium expansum: Mechanistic insights into antifungal activity

Botrytis cinerea and Penicillium expansum produce deterioration in fruit quality, causing losses to the food industry. Thus, plant essential oils (EOs) have been proposed as a sustainable alternative for minimizing the application of synthetic fungicides due to their broad-spectrum antifungal properties. This study investigated the efficacy of five EOs in suppressing the growth of B. cinerea and P. expansum and their potential antifungal mechanisms. EOs of Mentha × piperita L., Origanum vulgare L., Thymus vulgaris L., Eucalyptus globules Labill., and Lavandula angustifolia Mill., were screened for both fungi. The results showed that the EO of T. vulgaris and O. vulgare were the most efficient in inhibiting the growth of B. cinerea and P. expansum. The concentration increase of all EO tested increased fungi growth inhibition. Exposure of fungi to EOs of T. vulgaris and O. vulgare increased the pH and the release of constituents absorbing 260 nm and soluble proteins, reflecting membrane permeability alterations. Fluorescence microscopic examination revealed that tested EOs produce structural alteration in cell wall component deposition, decreasing the hypha width. Moreover, propidium iodide and Calcein-AM stains evidenced the loss of membrane integrity and reduced cell viability of fungi treated with EOs. Fungi treated with EOs decreased the mitochondria activity and the respiratory process. Therefore, these EOs are effective antifungal agents against B. cinerea and P. expansum, which is attributed to changes in the cell wall structure, the breakdown of the cell membrane, and the alteration of the mitochondrial activity.

Mixed analytical model to estimate the anisotropic effective thermal conductivity and in-reactor performance of metallic microcell UO2

A mixed analytical model is utilized to estimate the effective thermal conductivity of microcell UO2 pellets. The proposed model consists of a mixture of parallel and series structural models that collectively take into account the unique cell geometry of the anisotropic metal network and the corresponding fractional contribution to the heat flow. This relatively simple structure model can explain the anisotropy of the thermal conductivity of UO2-Mo microcells, as observed in both experimental tests and numerical calculations. The physics-based mixed analytical model allows us to accommodate the effects of the UO2 burnup and wall structure changes on the effective thermal conductivity of microcell UO2 pellets. To validate the model's ability to predict the burnup dependence, the reduced fuel centerline temperature in a UO2 -5vol% Cr microcell under irradiation was estimated at selected burnup levels and compared to the temperature evolution observed in a Halden reactor test, in which the sample pellets were irradiated up to 16MWd/kgU. The comparison demonstrated that the mixed analytical model suitably predicts the fuel temperature changes in irradiated UO2 -5vol% Cr microcells. The model proposed here is a preliminary type based on limited experimental data, and the parameters of the model could be modified further with the accumulation of more measurement data.

E. coli Cell Lysis Induced by Lys394 Enzyme Assisted by Magnetic Nanoparticles Exposed to Non-Heating Low-Frequency Magnetic Field.

The spreading of microbial pathogens with more and more resistance to traditional low-molecular antibiotic agents demands new approaches to antibacterial therapy. The employment of bacteriophage enzymes capable of breaking bacterial cell walls has attracted much interest within this context. The specific features of the morphology of Gram-negative bacteria prevent the effective direct usage of lytic enzymes and require assistance from additional helpers to facilitate cell lysis. The current work is devoted to the study of boosting the lysis of Escherichia coli (E. coli) JM 109 and MH 1 strains induced by Lys394 bacteriophage endolysin by means of rod-like (56 × 13 nm) magnetic nanoparticles (MNPs) activated by a non-heating low-frequency magnetic field (LF MF) with a frequency of 50 Hz and a flux density of 68.5 mT in a pulse-pause mode (1 s on and 0.3 s off). According to theoretical assumptions, the mechanism of MNP assistance is presumably based upon the disordering of the outer membrane that facilitates enzyme permeation into peptidoglycans to its substrate. It is found that the effect of the LF MF reaches an almost a twofold acceleration of the enzyme reaction, resulting in almost 80 and 70%, respectively, of lysed E. coli JM 109 and MH 1 cells in 21 min. An increase in the membrane permeability was proven by two independent experiments employing β-lactamase periplasmic enzyme leakage and Nile Red (NR) hydrophobic dye fluorescence. It is shown that the outer membrane disordering of E. coli caused by exposure to LF MF nanoparticle movement leads to almost complete (more than 80%) β-lactamase release out of the cells' periplasm to the buffer suspension. Experiments with NR (displaying fluorescence in a non-polar medium only) reveal a drastic reduction in NR fluorescence intensity, reaching a change of an order of magnitude when exposed to LF MF. The data obtained provide evidence of changes in the bacterial cell wall structure. The result shown open up the prospects of non-heating LF MF application in enhancing enzyme activity against Gram-negative pathogens.

In Vivo Adaptive Bayesian Regularized Lagrangian Carotid Strain Imaging for Murine Carotid Arteries and Its Associations With Histological Findings

ObjectivesNon-invasive methods for monitoring arterial health and identifying early injury to optimize treatment for patients are desirable. The objective of this study was to demonstrate the use of an adaptive Bayesian regularized Lagrangian carotid strain imaging (ABR-LCSI) algorithm for monitoring of atherogenesis in a murine model and examine associations between the ultrasound strain measures and histology. MethodsUltrasound radiofrequency (RF) data were acquired from both the right and left common carotid artery (CCA) of 10 (5 male and 5 female) ApoE tm1Unc/J mice at 6, 16 and 24 wk. Lagrangian accumulated axial, lateral and shear strain images and three strain indices—maximum accumulated strain index (MASI), peak mean strain of full region of interest (ROI) index (PMSRI) and strain at peak axial displacement index (SPADI)—were estimated using the ABR-LCSI algorithm. Mice were euthanized (n = 2 at 6 and 16 wk, n = 6 at 24 wk) for histology examination. ResultsSex-specific differences in strain indices of mice at 6, 16 and 24 wk were observed. For male mice, axial PMSRI and SPADI changed significantly from 6 to 24 wk (mean axial PMSRI at 6 wk = 14.10 ± 5.33% and that at 24 wk = –3.03 ± 5.61%, p < 0.001). For female mice, lateral MASI increased significantly from 6 to 24 wk (mean lateral MASI at 6 wk = 10.26 ± 3.13% and that at 24 wk = 16.42 ± 7.15%, p = 0.048). Both cohorts exhibited strong associations with ex vivo histological findings (male mice: correlation between number of elastin fibers and axial PMSRI: rs = 0.83, p = 0.01; female mice: correlation between shear MASI and plaque score: rs = 0.77, p = 0.009). ConclusionThe results indicate that ABR-LCSI can be used to measure arterial wall strain in a murine model and that changes in strain are associated with changes in arterial wall structure and plaque formation.

Effects of different preservation schemes on isolated rat artery.

Allogeneic blood vessels are regarded as one of the best natural substitutes for diseased blood vessels due to their good vascular compliance and histocompatibility. Since the supply and demand of allograft blood vessels do not always match in time and space, a good preservation scheme for isolated blood vessels is essential. The abdominal aortas of 110 male Sprague-Dawley (SD) rats were randomly divided into three groups, including cold storage group (4°C) (CSG), frozen storage group (FSG) and ambient storage group (25 ± 2°C) (ASG). Seven time points of preservation for 1, 3, 5, 7, 14, 30 and 90 days were set for detection. The changes in vascular physiological function were evaluated by MTT test and vasoconstriction ability detection, and the changes in vascular wall structure were evaluated by the tension tolerance test and pathological staining. The vascular function of CSG was better than FSG within first the 7 days, but the result was opposite since the 14th day. The vascular wall structure, collagen and elastic fibres of vessels, in CSG, showed oedema within 30 days, and continuous disintegration and rupture at 90 days. The vessel wall structure of FSG remained intact within 90 days. The tensile strength of the vessels in CSG was better than that in FSG within 5 days, and there was no statistical difference between the two groups between the 7th and 30th day, and then, the FSG was higher than CSG on the 90th day. Both cold storage and frozen storage could be applied as safe and effective preservation schemes for isolated rat artery within first 30 days. Cold storage is recommended when the storage time is <14 days, and then, frozen storage is better.

Long-term menopause exacerbates vaginal wall support injury in ovariectomized rats by regulating amino acid synthesis and glycerophospholipid metabolism.

Menopause is a risk factor for pelvic organ prolapse (POP) and is frequently associated with diminished vaginal wall support. To uncover relevant molecular mechanisms and provide potential therapeutic targets, we evaluated changes in the transcriptome and metabolome of the vaginal wall in ovariectomized rats to identify important molecular changes. Sixteen adult female Sprague-Dawley rats were randomly assigned to either the control or menopause group. Seven months after the operation, hematoxylin and eosin (H&E) staining and Masson trichrome staining were used to observe changes in the rat vaginal wall structure. Differentially expressed genes (DEGs) and metabolites (DEMs) in the vaginal wall were detected by RNA-sequencing and LC-MS, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of DEGs and DEMs were performed. We verified that long-term menopause causes vaginal wall injury by H&E and Masson trichrome staining. From the multiomics analyses, 20,669 genes and 2193 metabolites were identified. Compared with the control group, 3255 DEGs were found in the vaginal wall of long-term menopausal rats. Bioinformatics analysis showed that the DEGs were mainly enriched in mechanistic pathways, including cell-cell junction, extracellular matrix, muscle tissue developments, the PI3K-Akt signaling pathway, the MAPK signaling pathway, tight junctions and the Wnt signaling pathway. Additionally, 313 DEMs were found, and they consisted mostly of amino acids and their metabolites. DEMs were also enriched in mechanistic pathways, such as glycine, serine and threonine metabolism, glycerophospholipid metabolism, gap junctions and ferroptosis. Coexpression analysis of DEGs and DEMs revealed that biosynthesis of amino acids (isocitric acid and PKM) and glycerophospholipid metabolism (1-(9Z-hexadecenoyl)-sn-glycero-3-phosphocholine and PGS1) are critical metabolic pathways, suggesting that POP induced by menopause may be associated with the regulation of these processes. The findings showed that long-term menopause greatly exacerbated vaginal wall support injury by decreasing the biosynthesis of amino acids and interfering with glycerophospholipid metabolism, which may result in POP. This study not only clarified that long-term menopause exacerbates damage to the vaginal wall but also provided insight into the potential molecular mechanisms by which long-term menopause induces POP.

Effects of cereal grain cell wall composition and structure on starch digestion.

Wheat is an important food crop, and its characteristics vary depending on the region of cultivation; different environments have varying effects on the composition of the grains. We previously reported the effects of environmental factors on wheat grain cell wall composition and structure. The variations in the structure of aleurone cell walls between different wheat samples were examined to determine the effects of aleurone cell walls on grain starch digestion properties. Ten different varieties of wheat grains with different aleurone cell wall structure and composition constituted a simple research system used to investigate their effect on the starch digestion of bread. The aleurone cell wall thickness ranged from 3.05 μm to 4.67 μm, and the arabinose to xylose ratio of water-extractable arabinoxylan was in the range 0.79-0.97. With the increase in arabinoxylans content or cell wall thickness, the total digestibility of starch within the bread decreased; this phenomenon may be related to the changes in the interaction between polysaccharides and starch granules in this process. The results of the present study showed that the wheat cell wall structure has a great impact on starch hydrolysis, indicating that the change in the digestibility of starch in flour and bread may be a result of changes in the cell wall structure leading to different combinations, thus affecting digestibility. The present study showed that the cell wall combines the starch granules during the bread-making process; thus, the diffusion of enzymes through the cell wall was hindered. © 2023 Society of Chemical Industry.