Using an ER-specific optogenetic mechanostimulator to understand the mechanosensitivity of the endoplasmic reticulum.

The ability of cells to perceive and respond to mechanical cues is essential for numerous biological activities. Emerging evidence indicates important contributions of organelles to cellular mechanosensitivity and mechanotransduction. However, whether and how the endoplasmic reticulum (ER) senses and reacts to mechanical forces remains elusive. To fill the knowledge gap, after developing a light-inducible ER-specific mechanostimulator (LIMER), we identify that mechanostimulation of ER elicits a transient, rapid efflux of Ca2+ from ER in monkey kidney COS-7 cells, which is dependent on the cation channels transient receptor potential cation channel, subfamily V, member 1 (TRPV1) and polycystin-2 (PKD2) in an additive manner. This ER Ca2+ release can be repeatedly stimulated and tuned by varying the intensity and duration of force application. Moreover, ER-specific mechanostimulation inhibits ER-to-Golgi trafficking. Sustained mechanostimuli increase the levels of binding-immunoglobulin protein (BiP) expression and phosphorylated eIF2α, two markers for ER stress. Our results provide direct evidence for ER mechanosensitivity and tight mechanoregulation of ER functions, placing ER as an important player on the intricate map of cellular mechanotransduction.

Autophagosome biogenesis and organelle homeostasis in plant cells.

Autophagy is one of the major highly inducible degradation processes in response to plant developmental and environmental signals. In response to different stimuli, cellular materials, including proteins and organelles, can be sequestered into a double membrane autophagosome structure either selectively or non-selectively. The formation of an autophagosome as well as its delivery into the vacuole involves complex and dynamic membrane processes. The identification and characterization of the conserved autophagy-related (ATG) proteins and their related regulators have greatly advanced our understanding of the molecular mechanism underlying autophagosome biogenesis and function in plant cells. Autophagosome biogenesis is tightly regulated by the coordination of multiple ATG and non-ATG proteins, and selective cargo recruitment. This review updates our current knowledge of autophagosome biogenesis, with special emphasis on the core molecular machinery that drives autophagosome formation, and autophagosome-organelle interactions under abiotic stress conditions.

Comparative peptidomics analysis in the discovery of umami peptides from Chinese Douchi.

Douchi is a kind of traditional Chinese fermented soybean product with outstanding umami taste. Besides the umami amino acids in Douchi, peptides were also considered as an important contributor for the umami taste of Douchi. Peptides with molecular weight below 0.66 kDa accounted for more than 50 % in all samples except for TongChuan Douchi, and a total of 421 peptides were identified from the ten kinds of Douchi samples by using LC-MS/MS. Combined with sensory evaluation results, 19 peptides containing Glu, Asp or known umami peptide sequences were chosen as potential umami peptides via PLS-DA and RDA analysis. Among them, 17 soluble peptides exhibited obvious umami taste and the threshold of 7 peptides were lower than MSG solution. Especially, the VD was detected with a minimum umami taste threshold at 0.16 mg/mL. The results indicated that the umami peptides might be the important components affecting the umami taste of Douchi.

A novel edible solid fat substitute: Preparation of biphasic stabilized bigels based on glyceryl monolaurate and gellan gum.

Solid fats contribute to a delicate and pleasant flavor for food, but its excessive intake increases the risk of cardiovascular disease. Bigel is considered a promising solid fat substitute as it significantly reduces fat content while meeting consumer demands for food flavor and a balanced diet. In this study, bigels were prepared by mixing glyceryl monolaurate-based oleogel (10 wt%) and gellan gum-based hydrogel (0.8 wt%) at ratios of 1:3, 1:1, and 3:1. The microscopic results indicated that the oleogel/hydrogel ratios influenced the structure of bigels, forming oil-in-water, bi-continuous, and water-in-oil bigels with the increase of oleogel proportion, respectively. All bigels presented a semi-solid structure dominated by elasticity, and their hardness, gumminess, chewiness, and cohesiveness increased with the enhancement of hydrogel proportion. Among them, the bigels (S25:L75 and S25:H75) prepared with an oleogel/hydrogel ratio of 1:3 showed excellent freeze-thaw stability, maintaining an oil holding capacity of >95 % after three freeze-thaw cycles. Meanwhile, they also presented good oxidative stabilities, where the peroxide values and malondialdehyde contents were below 0.07 g/100 g and 1.5 mg MDA/kg at 12 d, respectively. Therefore, S25:L75 and S25:H75 are expected to be green, low-cost, healthy, and sustainable alternatives to solid fats.

FREE1 regulates phagophore closure in plants.

Adenosine monophosphate-activated protein kinase (AMPK), the central energy sensor in more complex eukaryotes, can activate macroautophagy/autophagy upon cellular energy deficiency. However, the regulatory role of nutrient sensing in mediating phagophore closure to generate an autophagosome remains unknown. The evolutionarily conserved endosomal sorting complexes required for transport (ESCRT) machinery has been postulated to regulate phagophore sealing, yet the signaling pathway modulating the ESCRT complex relocation from multivesicular body (MVB) to phagophore for closure remains unknown. We recently identified a plant unique pleiotropic protein FREE1 (FYVE DOMAIN PROTEIN REQUIRED FOR ENDOSOMAL SORTING 1), which is phosphorylated by the plant energy sensor SnRK1 (SNF1-related kinase 1) and bridges the ATG conjugation system and ESCRT machinery to regulate phagophore sealing upon nutrient starvation. This study elucidated the bona fide roles and underlying mechanism of cellular energy-sensing pathways in regulating compartment sealing.

Characterization of key aroma-active compounds in different types of Douchi based on molecular sensory science approaches.

To attain the differences in the flavor profile of Douchi, the key aroma-active compounds of three types of Douchi were investigated. The "Sauce-like", "Smoky", "Nutty", "Roast", "Caramel", and "Flower" of Douchi were favored by customers. Further, a total of 179 volatile compounds were identified using HS-SPME-GC-MS, and 29 aroma compounds were detected using GC-O-MS. Based on the quantification, 9, 13, and 10 compounds were regarded as aroma-active compounds in Yangjiang Douchi (YJ), Pingjiang Douchi (PJ), and Liuyang Douchi (LY), respectively. Moreover, the mixture of these aroma-active compounds successfully simulated the main aromas of PJ, LY, and YJ. And omission experiments confirmed that guaiacol was the key aroma compound for LY, benzene acetaldehyde, dimethyl trisulfide, and 2-acetyl pyrrole were important for YJ, benzene acetaldehyde and 3,5-diethyl-2-methyl pyrazine notably contributed to key aroma of PJ.

Frequency-domain terahertz optoacoustics for non-contact quantitative detection of gas, liquid, and solid samples.

Terahertz optoacoustics (THz-OA) combines the advantages of abundant molecular characteristic absorptions in a terahertz band and the low attenuation through ultrasonic detection. Frequency-domain THz-OA, benefiting from the compact and the low cost of a continuous-wave THz source, has been used in gas detection and sensing. However, liquid and solid detections are hard to achieve due to the sensitivity limitation of existing technologies. Here we present a high-sensitivity frequency-domain THz-OA system with customized optoacoustic cells to accomplish non-contact quantitative detection of gas, liquid, and solid samples. The relationships between signal amplitudes and sample concentration, volume and temperature are discussed separately, revealing a potential application of this technology.

Circular RNA circTMEM59 inhibits progression of pancreatic ductal adenocarcinoma by targeting miR-147b/SOCS1: An in vitro study.

Purpose: This study aimed to detect the role and mechanism of circTMEM59 in pancreatic ductal adenocarcinoma (PDAC). Methods: 66 paired PDAC tissues and normal samples were harvested from patients diagnosed and undergoing pancreatic cancer surgery in our hospital. The expression of circTMEM59 in PDAC tissues and cell lines was detected. Based on bioinformatics information, the circTMEM59 mimics, miR-147b mimics, miR-147b inhibitor and si-suppressor of cytokine signaling 1 (SOCS1) were transfected into PDAC cells. The expression levels of circTMEM59, miR-147b and SOCS1 were detected by quantitative real-time polymerase chain reaction (qRT-PCR). RNA interaction was confirmed by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Cell invasion and proliferation were evaluated by Transwell and Cell Counting Kit-8 (CCK-8) assays. The protein expression was detected by Western blot. Results: CircTMEM59 was confirmed to be downregulated in PDAC tumor tissues and cells. Low expression of circTMEM59 was closely correlated with the short survival time and poor clinicopathological characteristics. By up-regulating the expression of circTMEM59 in PDAC cells, cell proliferation, invasion and epithelial-mesenchymal transition (EMT) were inhibited. More importantly, miR-147b could be sponged by circTMEM59, and knockdown of miR-147b inhibited progression of PDAC cells. Further study revealed that SOCS1 was targeted by miR-147b. SOCS1 expression was negatively related to miR-147b expression and positively related to circTMEM59 expression in PDAC tissues. Upregulated miR-147b and downregulated SOCS1 could rescue the effects of circTMEM59 on cell proliferation, EMT and invasion. Conclusion: Our data indicated that circTMEM59 inhibited cell proliferation, invasion and EMT of PDAC by regulating miR-147b/SOCS1 axis.

A chemometric-assisted method for automatic, rapid and non-targeted detection of multi-pesticides in plant-derived foods by gas chromatography-mass spectrometry.

An automatic, rapid and non-targeted detection method for multi-pesticides in plant-derived foods was developed by gas chromatography-mass spectrometry and chemometrics. In this method, a novel algorithm named moving window iterative target transformation factor analysis was proposed. Although there are challenges of peak overlapping and background interference, the retention time and corrected mass spectra of unknown pesticides can be automatically obtained through iteration calculation in the 'moving window' with reference to the pesticide mass spectral library. One mixed pesticide standard and nine varieties of plant-derived foods were investigated with the proposed method. By contrast, a fast temperature programme was used to shorten detection time compared to the standard temperature programme. For the mixed standard, the mass spectra and retention times of all 39 pesticides were successfully obtained from the overlapping signal. Furthermore, all spiked pesticides were successfully detected in plant-derived foods within 10 min using a fast temperature programme.

A Century Journey of Organelles Research in the Plant Endomembrane System.

We are entering an exciting century in the study of the plant organelles in the endomembrane system. Over the past century, especially within the past 50 years, tremendous advancements have been made in the complex plant cell to generate a much clearer and informative picture of plant organelles, including the molecular/morphological features, dynamic/spatial behavior, and physiological functions. Importantly, all these discoveries and achievements in the identification and characterization of organelles in the endomembrane system would not have been possible without: 1) the innovations and timely applications of various state-of-art cell biology tools and technologies for organelle biology research, 2) the continuous efforts in developing and characterizing new organelle markers by the plant biology community; and 3) the landmark studies on the identification and characterization of the elusive organelles. While molecular aspects and results for individual organelles have been extensively reviewed, the development of the techniques for organelle research in plant cell biology is less appreciated. As one of the ASPB Centennial Reviews on "organelle biology", here we aim to take a journey across a century of organelle biology research in plants by highlighting the important tools (or landmark technologies) and key scientists that contributed to visualize organelles. We then highlight the landmark studies leading to the identification and characterization of individual organelles in the plant endomembrane systems.

High-performance bismuth vanadate photoanodes cocatalyzed with nitrogen, sulphur co-doped ferrocobalt-metal organic frameworks thin layer for photoelectrochemical water splitting.

In this study, we prepare a highly efficient BiVO4 photoanode co-catalyzed with an ultrathin layer of N, S co-doped FeCo-Metal Organic Frameworks (MOFs) for photoelectrochemical water splitting. The introduction of N and S into FeCo-MOFs enhances electron and mass transfer, exposing more catalytic active sites and significantly improving the catalytic performance of N, S co-doped FeCo-based MOFs in water oxidation. The optimized BiVO4/NS-FeCo-MOFs photoanode exhibits impressive results, with a photocurrent density of 5.23 mA cm-2 at 1.23 V vs. Reversible Hydrogen Electrode (RHE) and an incident photon-to-charge conversion efficiency (IPCE) of 74.4 % at 450 nm in a 0.1 M phosphate buffered solution (pH = 7). These values are 4.84 times and 6.2 times higher than those of the original BiVO4 photoanode, respectively. Furthermore, the optimized BiVO4/NS-FeCo-MOFs photoanode demonstrates exceptional long-term stability, maintaining 96 % of the initial current after five hours.

Introducing Specific Iodine Ions in Perovskite-Based Nanocomplex to Cater for Versatile Biomedical Imaging and Tumor Radiotherapy.

Multimodal biomedical imaging and imaging-guided therapy have garnered extensive attention owing to the aid of nanoagents with the aim of further improving the therapeutic efficacy of diseases. The ability to engineer nanocomplexes (NCs) or control how they behave within an organism remains largely elusive. Here, a multifunctional nanoplatform is developed based on stabilized I-doped perovskite, CsPbBr3 -x Ix @SiO2 @Lip-c(RGD)2 (PSL-c(RGD)2 ) NCs. In particular, by regulating the amount of regular I- ions introduced, the fluorescence emission spectrum of perovskite-based NCs can be modulated well to match the requirement for biomedical optical imaging at the scale from molecule, cell to mouse; doping 125 I enables the nanoformulation to be competent for single-photon emission computed tomography (SPECT) imaging; the introduction of 131 I- imparts the NCs with the capability for radiotherapy. Through facile manipulation of specific iodine ions, this nanoplatform exhibits a remarkable ability to match multifunctional biomedical imaging and tumor therapy. In addition, their in vivo behavior can be manipulated by adjusting the thickness of the silica shell and the surface polarity for more practical applications. These experimental explorations offer a novel approach for engineering desirable multimodal NCs to simultaneously image and combat malignant tumors.

Exploring the Release of Elastin Peptides Generated from Enzymatic Hydrolysis of Bovine Elastin via Peptide Mapping.

To enhance the understanding of enzymatic hydrolysis and to accelerate the discovery of key bioactive peptides within enzymatic products, this research focused on elastin as the substrate and investigated the variations in peptide profiles and the production of key bioactive peptides (those exceeding 5% of the total) and their impacts on the biological activity of the hydrolysates. Through the application of advanced analytical techniques, such as stop-flow two-dimensional liquid chromatography and ultra-high-performance liquid chromatography-tandem mass spectrometry, the research tracks the release and profiles of peptides within elastin hydrolysates (EHs). Despite uniform peptide compositions, significant disparities in peptide concentrations were detected across the hydrolysates, hinting at varying levels of bioactive efficacy. A comprehensive identification process pinpointed 403 peptides within the EHs, with 18 peptides surpassing 5% in theoretical maximum content, signaling their crucial role in the hydrolysate's bioactivity. Of particular interest, certain peptides containing sequences of alanine, valine, and glycine were released in higher quantities, suggesting Alcalase® 2.4L's preference for these residues. The analysis not only confirms the peptides' dose-responsive elastase inhibitory potential but also underscores the nuanced interplay between peptide content, biological function, and their collective synergy. The study sets the stage for future research aimed at refining enzymatic treatments to fully exploit the bioactive properties of elastin.

The seven rice vacuolar sorting receptors localize to prevacuolar compartments.

Vacuolar sorting is critically important in plants as it regulates the mobilization of proteins and plays a major role in important agricultural traits like yield and seed protein content. Vacuolar sorting receptors (VSRs) are integral membrane proteins that mediate protein trafficking from the Golgi apparatus to the vacuole via the intermediate membrane-bound prevacuolar compartment (PVC)/multivesicular body (MVB). VSR proteins, such as an 80 kD (BP-80) from pea, also serve as markers for PVC/MVB. Dissecting VSR-mediated protein trafficking pathways may provide ways to enhance agronomic traits and crop yield. Green fluorescence protein (GFP) fusions with the seven Arabidopsis (Arabidopsis thaliana) VSRs were previously shown to localize to PVCs in transgenic tobacco BY-2 cells. The Rice (Oryza sativa) genome contains seven VSRs (OsVSR1-7), but little is known about their subcellular localizations. Here we studied the subcellular localization of OsVSR1-7 b y using a reporter approach, in which GFP-OsVSR1-7 fusions containing the transmembrane domain (TMD) and cytoplasmic tail (CT) of individual OsVSR were expressed in the protoplasts of rice, transgenic tobacco BY-2 cells and transgenic rice plants. Immunofluorescent labelling studies and confocal laser scanning microscope observation demonstrated that the seven OsVSRs are localized to PVCs and form ring-like structures upon wortmannin treatment. Therefore, we have verified the subcellular localization of OsVSR1-7 in this study. The OsVSRs tagged with GFP can serve as PVCs/MVBs markers in rice for the future studies.

ABLs and TMKs are co-receptors for extracellular auxin.

Extracellular perception of auxin, an essential phytohormone in plants, has been debated for decades. Auxin-binding protein 1 (ABP1) physically interacts with quintessential transmembrane kinases (TMKs) and was proposed to act as an extracellular auxin receptor, but its role was disputed because abp1 knockout mutants lack obvious morphological phenotypes. Here, we identified two new auxin-binding proteins, ABL1 and ABL2, that are localized to the apoplast and directly interact with the extracellular domain of TMKs in an auxin-dependent manner. Furthermore, functionally redundant ABL1 and ABL2 genetically interact with TMKs and exhibit functions that overlap with those of ABP1 as well as being independent of ABP1. Importantly, the extracellular domain of TMK1 itself binds auxin and synergizes with either ABP1 or ABL1 in auxin binding. Thus, our findings discovered auxin receptors ABL1 and ABL2 having functions overlapping with but distinct from ABP1 and acting together with TMKs as co-receptors for extracellular auxin.

An improved multi-scale gradient generative adversarial network for enhancing classification of colorectal cancer histological images.

Introduction: Deep learning-based solutions for histological image classification have gained attention in recent years due to their potential for objective evaluation of histological images. However, these methods often require a large number of expert annotations, which are both time-consuming and labor-intensive to obtain. Several scholars have proposed generative models to augment labeled data, but these often result in label uncertainty due to incomplete learning of the data distribution. Methods: To alleviate these issues, a method called InceptionV3-SMSG-GAN has been proposed to enhance classification performance by generating high-quality images. Specifically, images synthesized by Multi-Scale Gradients Generative Adversarial Network (MSG-GAN) are selectively added to the training set through a selection mechanism utilizing a trained model to choose generated images with higher class probabilities. The selection mechanism filters the synthetic images that contain ambiguous category information, thus alleviating label uncertainty. Results: Experimental results show that compared with the baseline method which uses InceptionV3, the proposed method can significantly improve the performance of pathological image classification from 86.87% to 89.54% for overall accuracy. Additionally, the quality of generated images is evaluated quantitatively using various commonly used evaluation metrics. Discussion: The proposed InceptionV3-SMSG-GAN method exhibited good classification ability, where histological image could be divided into nine categories. Future work could focus on further refining the image generation and selection processes to optimize classification performance.

Dietary Taurine Improves Growth Performance and Intestine Health via the GSH/GSSG Antioxidant System and Nrf2/ARE Signaling Pathway in Weaned Piglets.

Early weaning of piglets was prone to increase reactive oxygen species, disrupt the redox balance, decrease antioxidant capacity, cause oxidative stress and intestinal oxidative damage, and lead to diarrhea in piglets. This research aimed to study dietary taurine (Tau) supplementation at a level relieving intestinal oxidative damage in early-weaned piglets. A total of 48 piglets were assigned to four groups of 12 individuals and fed a basal diet with 0.0% Tau (CON), 0.2% Tau (L-Tau), 0.3% Tau (M-Tau), or 0.4% Tau (H-Tau), respectively. The animal experiment lasted 30 days. The final weight, weight gain, average daily gain, and feed conversion rate increased with the increase in dietary Tau (Linear, p < 0.05; Quadratic p < 0.05), while the diarrhea index of piglets decreased with the increase in dietary Tau (Linear, p < 0.05). Serum malondialdehyde, nitric oxide (NO), D-lactose, and oxidized glutathione (GSSG) concentrations decreased with the increase in dietary Tau (Linear, p < 0.05). The O2•- and •OH clearance rate in serum, liver, and jejunum mucosa increased with the increase in dietary Tau (Linear, p < 0.05). Serum superoxide dismutase (SOD) activity, glutathione peroxidase (GPX) activity, catalase (CAT) activity, and peroxidase (POD) activity and total antioxidant capacity increased with the increase in dietary Tau (Linear, p < 0.05). The serum glutathione (GSH) concentration and the ratio of GSH to GSSG increased with the increase in dietary Tau (Linear, p < 0.05). The POD and glutathione synthase activity in the liver and jejunum mucosa increased with the increase in dietary Tau (Linear, p < 0.05). The mRNA abundances of HO-1 and GPX1 in the H-Tau group were higher than that in the L-Tau, M-Tau, and CON groups (p < 0.05). The mRNA abundances of SOD1 and Nrf2 in the M-Tau and H-Tau groups were higher than in the L-Tau and CON groups (p < 0.05). The mRNA abundance of SOD2 in the L-Tau, M-Tau, and H-Tau groups was higher than in the CON group (p < 0.05). The VH and the ratio of VH to CD of jejunum and ileum increased with the increase in dietary Tau (Linear, p < 0.05). The mRNA abundances of occludens 1 and claudin 1 in the H-Tau group were higher than that in the CON, L-Tau, and M-Tau (p < 0.05). The mRNA abundance of occludin in the L-Tau, M-Tau, and H-Tau groups was higher than that in CON (p < 0.05). The abundance of Firmicutes increased with the increase in dietary Tau (Linear, p < 0.05), while Proteobacteria and Spirochaetota decreased with the increase in dietary Tau (Linear, p < 0.05). Collectively, dietary supplementation of 0.3% and 0.4% Tau in feed could significantly improve the growth performance and enhance the antioxidant capacity of piglets.

Identification of novel α-glucosidase and ACE inhibitory peptides from Douchi using peptidomics approach and molecular docking.

In this study, the effect of Douchi extract (DWE) on α-glucosidase and angiotensin-converting enzymes (ACE) were investigated, and several novel peptides with inhibitory activity against α-glucosidase and ACE were identified using peptidomics approach based on UPLC-MS/MS. The average inhibition rates of DWE on α-glucosidase and ACE were 73.75-78.10% and 4.56-27.07%, respectively. In the DWE, a total of 710 peptides were detected. Two novel peptides with potential inhibitory activity against α-glucosidase were identified using the correlation analysis, database alignment and molecular docking methods. They were DVFRAIPSEVL and DRPSINGLAGAN, with the IC50 values of 0.121 and 0.128 mg/mL, respectively. Also, four novel peptides with potential inhibitory activity against ACE were identified: PSSPFTDLWD, EEQDERQFPF, PVPVPVQQAFPF and PSSPFTDL, with IC50 values of 1.388, 0.041, 0.761 and 0.097 mg/mL, respectively. These results indicated that combining peptidomics and molecular docking is an effective alternative strategy for rapidly screening numbers of novel bioactive peptides from foods.

Investigating the Structural Evolution and Catalytic Activity of c-Co/Co3Mo Electrocatalysts for Alkaline Hydrogen Evolution Reaction.

Transition metal alloys have emerged as promising electrocatalysts due to their ability to modulate key parameters, such as d-band electron filling, Fermi level energy, and interatomic spacing, thereby influencing their affinity towards reaction intermediates. However, the structural stability of alloy electrocatalysts during the alkaline hydrogen evolution reaction (HER) remains a subject of debate. In this study, we systematically investigated the structural evolution and catalytic activity of the c-Co/Co3Mo electrocatalyst under alkaline HER conditions. Our findings reveal that the Co3Mo alloy and H0.9MoO3 exhibit instability during alkaline HER, leading to the breakdown of the crystal structure. As a result, the cubic phase c-Co undergoes a conversion to the hexagonal phase h-Co, which exhibits strong catalytic activity. Additionally, we identified hexagonal phase Co(OH)2 as an intermediate product of this conversion process. Furthermore, we explored the readsorption and surface coordination of the Mo element, which contribute to the enhanced catalytic activity of the c-Co/Co3Mo catalyst in alkaline HER. This work provides valuable insights into the dynamic behavior of alloy-based electrocatalysts, shedding light on their structural stability and catalytic activity during electrochemical reduction processes.