The Effects of the Carrier and Ligand Spatial Conformation on RNA Nanodrug Cell Delivery.

Small interfering RNA (siRNA) highlights the immense therapeutic potential for cancer treatment. The major challenge in siRNA therapy is the effective RNA nanodrug delivery system, which is facilitated by the ligand and the carrier. In this study, we analyzed the binding specificity of linear RGD and circular RGD to αVß3 integrins by mapping the morphology using super-resolution direct stochastic optical reconstruction microscopy. Meanwhile, the binding dynamics was investigated using single-molecule force spectroscopy. Then, the effects of the ligand and carrier on RNA nanodrug cell entry dynamic parameters were evaluated at the single particle level by the force tracing technique. Furthermore, the delivery efficiency of RNA nanodrugs was assessed using AFM-based nanoindentation at the single cell level. This report will provide valuable insights for rational design strategies aiming to achieve improved efficiency for nanodrug delivery systems.

Unveiling the Correlation Between the Membrane Assembly of P-gp and Drug Resistance in Multiple Myeloma Using Super-Resolution Fluorescence Imaging.

Drug resistance in multiple myeloma (MM) poses a significant challenge to treatment efficacy, primarily attributed to P-glycoprotein (P-gp) dysfunction. This study delves into the elusive spatial organization of P-gp, aiming to enhance our understanding of its role in MM drug resistance by exploring the intricate relationship between molecular function and spatial arrangement. Employing super-resolution imaging of P-gp with the inhibitor probe Tariquidar-TAMR labeling on MM cell membranes, the research uncovered a more pronounced clustering distribution of P-gp in drug-resistant cells (MM1R) compared to drug-sensitive counterparts (MM1S). Further exploration revealed the clustering distribution of P-gp was heightened as cellular drug resistance increased in hypoxic condition, directly emphasizing the strong correlation between P-gp cluster morphology and drug resistance. Additionally, stable P-gp cluster formation was influenced by cross-linking of membrane carbohydrates, and disrupting these glycoprotein clusters could reduce cellular drug resistance, suggesting that altering distribution patterns of P-gp can modulate drug responsiveness. Finally, dexamethasone (Dex) treatment was revealed to enhance P-gp clustering distribution, particularly in MM1S cells, indicating that change degree in P-gp distribution correlate with the modifiable space of cellular drug responsiveness. This study provides insights into the correlation between P-gp assembly and cellular drug responsiveness, deepening our understanding of functional changes in MM drug resistance and offering valuable perspectives for overcoming this challenge.

Portable Saliva Sensor Based on Dual Recognition Elements for Detection of Caries Pathogenic Bacteria.

Dental caries is one of the most common diseases affecting more than 2 billion people's health worldwide. In a clinical setting, it is challenging to predict and proactively guard against dental cavities prior to receiving a confirmed diagnosis. Streptococcus mutans (S. mutans) in saliva has been recognized as the main causative bacterial agent that causes dental caries. High sensitivity, good selectivity, and a wide detection range are incredibly important factors to affect S. mutans detection in practical applications. In this study, we present a portable saliva biosensor designed for the early detection of S. mutans with the potential to predict the occurrence of dental cavities. The biosensor was fabricated using a S. mutans-specific DNA aptamer and S. mutans-imprinted polymers. Methylene blue was utilized as a redox probe in the sensor to generate current signals for analysis. When S. mutans enters complementarily S. mutans cavities, it blocks electron transfer between methylene blue and the electrode, resulting in decreases in the reduction current signal. The signal variations are associated with S. mutans concentrations that are useful for quantitative analysis. The linear detection range of S. mutans is 102-109 cfu mL-1, which covers the critical concentration of high caries risk. The biosensor exhibited excellent selectivity toward S. mutans in the presence of other common oral bacteria. The biosensor's wide detection range, excellent selectivity, and low limit of detection (2.6 cfu mL-1) are attributed to the synergistic effect of aptamer and S. mutans-imprinted polymers. The sensor demonstrates the potential to prevent dental caries.

Elucidating the Functional Mechanism of PTK7 in Cancer Development through Spatial Assembly Analysis Using Super Resolution Imaging.

Protein tyrosine kinase-7 (PTK7) has been reported as a vital participant in the Wnt signaling pathway, influencing tumorigenesis and metastasis. However, their specific roles in the mechanisms underlying cancer development and progression remain elusive. Here, using direct stochastic optical reconstruction microscopy (dSTORM) with aptamer-probe labeling, we first revealed that a weakening clustering distribution of PTK7 on the basal membranes happened as cellular migration increased during cancer progression. This correspondence was further supported by a diminished aggregated state of PTK7 caused by direct enhancement of cell migration. By comparing the alterations in PTK7 distribution with activation or inhibition of specific Wnt signaling pathway, we speculated that PTK7 could modulate cell migration by participating in the interplay between canonical Wnt (in MCF7 cells) and noncanonical Wnt signals (in MDA-MB-231 cells). Furthermore, we discovered that the spatial distribution morphology of PTK7 was also subject to the hydrolysis ability and activation state of the related hydrolase Matrix metallopeptidase14 (MMP14). This function-related specific assembly of PTK7 reveals a clear relationship between PTK7 and cancer. Meanwhile, potential molecular interactions predicted by the apparent assembly morphology can promote a deep understanding of the functional mechanism of PTK7 in cancer progress.

Recombinant human IL-37 attenuates acute cardiac allograft rejection in mice.

BACKGROUND: Allograft rejection remains a major obstacle to long-term graft survival. Although previous studies have demonstrated that IL-37 exhibited significant immunomodulatory effects in various diseases, research on its role in solid organ transplantation has not been fully elucidated. In this study, the therapeutic effect of recombinant human IL-37 (rhIL-37) was evaluated in a mouse cardiac allotransplantation model. METHODS: The C57BL/6 recipients mouse receiving BALB/c donor hearts were treated with rhIL-37. Graft pathological and immunohistology changes, immune cell populations, and cytokine profiles were analyzed on postoperative day (POD) 7. The proliferative capacities of Th1, Th17, and Treg subpopulations were assessed in vitro. Furthermore, the role of the p-mTOR pathway in rhIL-37-induced CD4+ cell inhibition was also elucidated. RESULTS: Compared to untreated groups, treatment of rhIL-37 achieved long-term cardiac allograft survival and effectively alleviated allograft rejection indicated by markedly reduced infiltration of CD4+ and CD11c+ cells and ameliorated graft pathological changes. rhIL-37 displayed significantly less splenic populations of Th1 and Th17 cells, as well as matured dendritic cells. The percentages of Tregs in splenocytes were significantly increased in the therapy group. Furthermore, rhIL-37 markedly decreased the levels of TNF-α and IFN-γ, but increased the level of IL-10 in the recipients. In addition, rhIL-37 inhibited the expression of p-mTOR in CD4+ cells of splenocytes. In vitro, similar to the in vivo experiments, rhIL-37 caused a decrease in the proportion of Th1 and Th17, as well as an increase in the proportion of Treg and a reduction in p-mTOR expression in CD4+ cells. CONCLUSIONS: We demonstrated that rhIL-37 effectively suppress acute rejection and induce long-term allograft acceptance. The results highlight that IL-37 could be novel and promising candidate for prevention of allograft rejection.

Interleukin-37 contributes to endometrial regenerative cell-mediated immunotherapeutic effect on chronic allograft vasculopathy.

BACKGROUND AIMS: Chronic allograft vasculopathy (CAV) remains a predominant contributor to late allograft failure after organ transplantation. Several factors have already been shown to facilitate the progression of CAV, and there is still an urgent need for effective and specific therapeutic approaches to inhibit CAV. Human mesenchymal-like endometrial regenerative cells (ERCs) are free from the deficiencies of traditional invasive acquisition methods and possess many advantages. Nevertheless, the exact immunomodulation mechanism of ERCs remains to be elucidated. METHODS: C57BL/6 (B6) mouse recipients receiving BALB/c mouse donor abdominal aorta transplantation were treated with ERCs, negative control (NC)-ERCs and interleukin (IL)-37-/-ERCs (ERCs with IL-37 ablation), respectively. Pathologic lesions and inflammatory cell infiltration in the grafts, splenic immune cell populations, circulating donor-specific antibody levels and cytokine profiles were analyzed on postoperative day (POD) 40. The proliferative capacities of Th1, Th17 and Treg subpopulations were assessed in vitro. RESULTS: Allografts from untreated recipients developed typical pathology features of CAV, namely endothelial thickening, on POD 40. Compared with untreated and IL-37-/-ERC-treated groups, IL-37-secreting ERCs (ERCs and NC-ERCs) significantly reduced vascular stenosis, the intimal hyperplasia and collagen deposition. IL-37-secreting ERCs significantly inhibited the proliferation of CD4+T cells, reduced the proportions of Th1 and Th17 cells, but increased the proportion of Tregs in vitro. Furthermore, in vitro results also showed that IL-37-secreting ERCs significantly inhibited Th1 and Th17 cell responses, abolished B-cell activation, diminished donor-specific antibody production and increased Treg proportions. Notably, IL-37-secreting ERCs remarkably downregulated the levels of pro-inflammatory cytokines (interferon-γ, tumor necrosis factor-α, IL-1ß, IL-6 and IL-17A) and increased IL-10 levels in transplant recipients. CONCLUSIONS: The knockdown of IL-37 dramatically abrogates the therapeutic ability of ERCs for CAV. Thus, this study highlights that IL-37 is indispensable for ERC-mediated immunomodulation for CAV and improves the long-term allograft acceptance.

In Situ Synthesis and Visualization of Membrane SNAP25 Nano-Organization.

Cryo-electron tomography (cryo-ET) can provide insights into the structure and states of natural membrane environments to explore the role of SNARE proteins at membrane fusion and understand the relationship between their subcellular localization/formation and action mechanism. Nevertheless, the identification of individual molecules in crowded and low signal-to-noise ratio membrane environments remains a significant challenge. In this study, cryo-ET is employed to image near-physiological state 293T cell membranes, specifically utilizing in situ synthesized gold nanoparticles (AuNPs) bound with cysteine-rich protein tags to single-molecularly labeled synaptosomal-associated protein 25 (SNAP25) on the membrane surface. The high-resolution images reveal that SNAP25 is predominantly located in regions of high molecular density within the cell membrane and aggregates into smaller clusters, which may increase the fusion efficiency. Remarkably, a zigzag arrangement of SNAP25 is observed on the cell membrane. These findings provide valuable insights into the functional mechanisms of SNARE proteins.

A Facile and Green Approach for the Preparation of Amine-Functionalized Poly(ethylene glycol) by Reducing Poly(ethylene glycol) Azide with Dithiothreitol.

A facile and green approach for the preparation of PEGn-NH2s from PEGn-N3s in water with DTT as the reduction reagent has been developed, avoiding the introduction of metal ions and difficulties in purification compared to the traditional synthesis process of PEGn-NH2s. A series of high-purity linear and multiarm PEGn-NH2s with different molecular weights were synthesized, demonstrating the versatility of this method. Additionally, HS-PEG45-NH2 with high fidelity of thiol and amine was easily prepared through the one-step two functional group conversion of N3-PEG45-S-S-PEG45-N3, and the PEG-based NH2-PEG@AuNPs were also prepared. This technology will promote the application of PEGn-NH2s in the fields of medicine and biomaterials.

An electrochemically cleanable pH electrode based on an electrodeposited iridium oxide-ruthenium oxide-titanium composite.

Biological contamination is an important issue in environmental pH detection, and our prepared electrochemically cleanable electrode may be an effective solution. By electrodepositing an iridium oxide-ruthenium oxide composite on a titanium sheet substrate, the electrode shows a sensitivity of 59.4 mV per pH in the pH range of 2-12 with high reproducibility, low hysteresis, high selectivity and high stability. It is worth mentioning that the electrode was proved to be electrochemically cleanable from biological contamination. When the cleaning time was 30 minutes, the electrode sensitivity rose from 50 to 58 mV per pH. Furthermore, the pH sensor, assembled from the prepared iridium-ruthenium oxide electrode and a home-made Ag/AgCl electrode, has similar electrode properties to those of commercial glass electrodes, but is also mechanically strong and electrochemically cleanable, which is promising for long-term deployment in natural environments.

Comprehensive metabolome characterization and comparison between two sources of Dragon's blood by integrating liquid chromatography/mass spectrometry and chemometrics.

Dragon's Blood (DB) serves as a precious Chinese medicine facilitating blood circulation and stasis dispersion. Daemonorops draco (D. draco; Qi-Lin-Jie) and Dracaena cochinchinensis (D. cochinchinenesis; Long-Xue-Jie) are two reputable plant sources for preparing DB. This work was designed to comprehensively characterize and compare the metabolome differences between D. draco and D. cochinchinenesis, by integrating liquid chromatography/mass spectrometry and untargeted metabolomics analysis. Offline two-dimensional liquid chromatography/ion mobility-quadrupole time-of-flight mass spectrometry (2D-LC/IM-QTOF-MS), by utilizing a powerful hybrid scan approach, was elaborated for multicomponent characterization. Configuration of an XBridge Amide column and an HSS T3 column in offline mode exhibited high orthogonality (A0 0.80) in separating the complex components in DB. Particularly, the hybrid high-definition MSE-high definition data-dependent acquisition (HDMSE-HDDDA) in both positive and negative ion modes was applied for data acquisition. Streamlined intelligent data processing facilitated by the UNIFI™ (Waters) bioinformatics platform and searching against an in-house chemical library (recording 223 known compounds) enabled efficient structural elucidation. We could characterize 285 components, including 143 from D. draco and 174 from D. cochinchinensis. Holistic comparison of the metabolomes among 21 batches of DB samples by the untargeted metabolomics workflows unveiled 43 significantly differential components. Separately, four and three components were considered as the marker compounds for identifying D. draco and D. cochinchinenesis, respectively. Conclusively, the chemical composition and metabolomic differences of two DB resources were investigated by a dimension-enhanced analytical approach, with the results being beneficial to quality control and the differentiated clinical application of DB.

Endometrial regeneration cell-derived exosomes loaded with siSLAMF6 inhibit cardiac allograft rejection through the suppression of desialylation modification.

BACKGROUNDS: Acute transplant rejection is a major component of poor prognoses for organ transplantation. Owing to the multiple complex mechanisms involved, new treatments are still under exploration. Endometrial regenerative cells (ERCs) have been widely used in various refractory immune-related diseases, but the role of ERC-derived exosomes (ERC-Exos) in alleviating transplant rejection has not been extensively studied. Signaling lymphocyte activation molecule family 6 (SLAMF6) plays an important role in regulating immune responses. In this study, we explored the main mechanism by which ERC-Exos loaded with siSLAMF6 can alleviate allogeneic transplant rejection. METHODS: C57BL/6 mouse recipients of BALB/c mouse kidney transplants were randomly divided into four groups and treated with exosomes. The graft pathology was evaluated by H&E staining. Splenic and transplanted heart immune cell populations were analyzed by flow cytometry. Recipient serum cytokine profiles were determined by enzyme-linked immunosorbent assay (ELISA). The proliferation and differentiation capacity of CD4+ T cell populations were evaluated in vitro. The α-2,6-sialylation levels in the CD4+ T cells were determined by SNA blotting. RESULTS: In vivo, mice treated with ERC-siSLAMF6 Exo achieved significantly prolonged allograft survival. The serum cytokine profiles of the recipients were significantly altered in the ERC-siSLAMF6 Exo-treated recipients. In vitro, we found that ERC-siSLAMF6-Exo considerably downregulated α-2,6-sialyltransferase (ST6GAL1) expression in CD4+ T cells, and significantly reduced α-2,6-sialylation levels. Through desialylation, ERC-siSLAMF6 Exo therapy significantly decreased CD4+ T cell proliferation and inhibited CD4+ T cell differentiation into Th1 and Th17 cells while promoting regulatory T cell (Treg) differentiation. CONCLUSIONS: Our study indicated that ERC-Exos loaded with siSLAMF6 reduce the amount of sialic acid connected to α-2,6 at the end of the N-glycan chain on the CD4+ T cell surface, increase the number of therapeutic exosomes endocytosed into CD4+ T cells, and inhibit the activation of T cell receptor signaling pathways, which prolongs allograft survival. This study confirms the feasibility of using ERC-Exos as natural carriers combined with gene therapy, which could be used as a potential therapeutic strategy to alleviate allograft rejection.

Evaluation and comparison of liquid chromatography/high-resolution mass spectrometry platforms for the separation and characterization of ginsenosides from the leaves of Panax ginseng.

The measurement of data repeatability in small-molecule metabolites acquired within and among different liquid chromatography-mass spectrometry (LC-MS) platforms is crucial for data sharing or data transfer in natural products research. This work was designed to investigate and evaluate the separation and detection performance of three commercial high-resolution LC-MS platforms (e.g., Agilent 6550 QTOF, Waters Vion IM-QTOF, and Thermo Scientific Orbitrap Exploris 120) using 68 ginsenoside references and the extract of Panax ginseng leaf. The retention time (tR), measured on these three platforms (under the same chromatography condition), showed good stability in different concentration tests, and within/among different instruments for both intra-day and inter-day precision examinations. Correlation in tR of ginsenosides was also highly determined on these three platforms. In spite of the different mass analyzers involved, these three platforms gave the accurate mass determination ability, especially enhanced resolution gained because of the ion mobility (IM) separation facilitated by IM-quadrupole time-of-flight. The current study has systematically evaluated the separation and MS detection performance enabled by three high-resolution LC-MS platforms taking ginsenosides as the template, and the reported findings can benefit the researchers for the selection of analytical platforms and the purpose of data sharing or data transfer.

Upregulation of TCPTP in Macrophages Is Involved in IL-35 Mediated Attenuation of Experimental Colitis.

Ulcerative colitis (UC) is a chronic intestinal inflammatory disease with complex etiology. Interleukin-35 (IL-35), as a cytokine with immunomodulatory function, has been shown to have therapeutic effects on UC, but its mechanism is not yet clear. Therefore, we constructed Pichia pastoris stably expressing IL-35 which enables the cytokines to reach the diseased mucosa, and explored whether upregulation of T-cell protein tyrosine phosphatase (TCPTP) in macrophages is involved in the mechanisms of IL-35-mediated attenuation of UC. After the successful construction of engineered bacteria expressing IL-35, a colitis model was successfully induced by giving BALB/c mice a solution containing 3% dextran sulfate sodium (DSS). Mice were treated with Pichia/IL-35, empty plasmid-transformed Pichia (Pichia/0), or PBS by gavage, respectively. The expression of TCPTP in macrophages (RAW264.7, BMDMs) and intestinal tissues after IL-35 treatment was detected. After administration of Pichia/IL-35, the mice showed significant improvement in weight loss, bloody stools, and shortened colon. Colon pathology also showed that the inflammatory condition of mice in the Pichia/IL-35 treatment group was alleviated. Notably, Pichia/IL-35 treatment not only increases local M2 macrophages but also decreases the expression of inflammatory cytokine IL-6 in the colon. With Pichia/IL-35 treatment, the proportion of M1 macrophages, Th17, and Th1 cells in mouse MLNs were markedly decreased, while Tregs were significantly increased. In vitro experiments, IL-35 significantly promoted the expression of TCPTP in macrophages stimulated with LPS. Similarly, the mice in the Pichia/IL-35 group also expressed more TCPTP than that of the untreated group and the Pichia/0 group.

Phenolic acids from Prunella vulgaris alleviate cardiac remodeling following myocardial infarction partially by suppressing NLRP3 activation.

Acute myocardial infarction (MI) is one of the leading causes of mortality around the world. Prunella vulgaris (Xia-Ku-Cao in Chinese) is used in traditional Chinese medicine practice for the treatment of cardiovascular diseases. However, its active ingredients and mechanisms of action on cardiac remodeling following MI remain unknown. In this study, we investigated the cardioprotective effect of P. vulgaris on MI rat models. MI rats were treated with aqueous extract of P. vulgaris or phenolic acids from P. vulgaris, including caffeic acid, ursolic acid or rosmarinic acid, 1 day after surgery and continued for the following 28 days. Then the cardioprotective effect, such as cardiac function, inflammatory status, and fibrosis areas were evaluated. RNA-sequencing (RNA-seq) analysis, real-time polymerase chain reaction (PCR), western blotting, and ELISA were used to explore the underlying mechanism. In addition, ultra-high performance liquid chromatography/mass spectrometer analysis was used to identify the chemicals from P. vulgaris. THP-1NLRP3-GFP cells were used to confirm the inhibitory effect of P. vulgaris and phenolic acids on the expression and activity of NLRP3. We found that P. vulgaris significantly improved cardiac function and reduced infarct size. Meanwhile, P. vulgaris protected cardiomyocyte against apoptosis, evidenced by increasing the expression of anti-apoptosis protein Bcl-2 in the heart and decreasing lactate dehydrogenase (LDH) levels in serum. Results from RNA-seq revealed that the therapeutic effect of P. vulgaris might relate to NLRP3-mediated inflammatory response. Results from real-time PCR and western blotting confirmed that P. vulgaris suppressed NLRP3 expression in MI heart. We also found that P. vulgaris suppressed NLRP3 expression and the secretion of HMGB1, IL-1ß, and IL-18 in THP-1NLRP3-GFP cells. Further studies indicated that the active components of P. vulgaris were three phenolic acids, those were caffeic acid, ursolic acid, and rosmarinic acid. These phenolic acids inhibited LPS-induced NLRP3 expression and activity in THP-1 cells, and improved cardiac function, suppressed inflammatory aggregation and fibrosis in MI rat models. In conclusion, our study demonstrated that P. vulgaris and phenolic acids from P. vulgaris, including caffeic acid, ursolic acid, and rosmarinic acid, could improve cardiac function and protect cardiomyocytes from ischemia injury during MI. The mechanism was partially related to inhibiting NLRP3 activation.

[Characterization and identification of chemical components from Euodiae Fructus based on UHPLC-Q-TOF-MS].

A sensitive and efficient ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry(UHPLC-Q-TOF-MS) approach was established. Based on the self-developed information library, the chemical components from Euodiae Fructus were systematically characterized and identified. The chromatographic separation conditions(e. g., stationary phase,mobile phase, column temperature, and elution gradient) and MS detection conditions(nozzle voltage, capillary voltage, fragmentor,and collision energy) were optimized. Ultimately, an HSS T3 column(2. 1 mm×100 mm, 1. 8 µm) maintained at 35 ℃ was used,and 0. 1% formic acid water-acetonitrile at the flow rate of 0. 4 m L·min~(-1) was used as the mobile phase. Electrospray ionization was adopted to collect the positive and negative ion mass spectrometry data in Auto MS/MS mode. According to the reference compound comparison, fragment ion information interpretation, literature, and retrieval in the self-developed information library, 92 compounds were characterized or derived from the decoction of Euodiae Fructus, including 33 alkaloids, 23 flavonoids, 12 terpenoids, 12phenylpropanoids, and 12 others. Among them, 17 compounds were identified by comparison with the reference compounds, and 11compounds were unreported from Euodiae Fructus. This study realizes the rapid characterization and identification of multi-class chemical components in the decoction of Euodiae Fructus and provides a reference for the studies regarding its effective substances and quality control.

Metabolic stress-induced reciprocal loop of long noncoding RNA ZFAS1 and ZEB1 promotes epithelial-mesenchymal transition and metastasis of pancreatic cancer cells.

Pancreatic cancer (PC) development faces significant metabolic stress due to metabolic reprogramming and a distinct hypovascular nature, often leading to glucose and glutamine depletion. However, the adaption mechanisms by which PC adapts to these metabolic challenges have not yet been completely explored. Here, we found that metabolic stress induced by glucose and glutamine deprivation led to an overexpression of ZNFX1 antisense RNA 1 (ZFAS1). This overexpression played a significant role in instigating PC cell epithelial-mesenchymal transition (EMT) and metastasis. Mechanistically, ZFAS1 enhanced the interaction between AMPK, a key kinase, and ZEB1, the primary regulator of EMT. This interaction resulted in the phosphorylation and subsequent stabilization of ZEB1. Interestingly, ZEB1 also reciprocally influenced the transcription of ZFAS1 by binding to its promoter. Furthermore, when ZFAS1 was depleted, the nutrient deprivation-induced EMT of PC cells and lung metastasis in nude mice were significantly inhibited. Our investigations also revealed that ZFAS1-rich exosomes released from cells suffering glucose and glutamine deprivation promoted the EMT and metastasis of recipient PC cells. Corroborating these findings, a correlated upregulation of ZFAS1 and ZEB1 expression was observed in PC tissues and was associated with a poor overall survival rate for patients. Our findings highlight the involvement of a long noncoding RNA-driven metabolic adaptation in promoting EMT and metastasis of PC, suggesting ZFAS1 as a promising novel therapeutic target for PC metabolic treatment.

Assembly Characterization of Human Equilibrium Nucleoside Transporter 1 (hENT1) by Inhibitor Probe-Based dSTORM Imaging.

Nucleoside transporters (NTs) play an important role in the metabolism of nucleoside substances and the efficacy of nucleoside drugs. Its spatial information related to biofunctions at the single-molecule level remains unclear, owing to the limitation of the existing labeling methods and traditional imaging methods. Therefore, we synthesize the inhibitor-based fluorescent probe SAENTA-Cy5 and apply direct stochastic optical reconstruction microscopy (dSTORM) to conduct refined observation of human equilibrative nucleoside transporter 1 (hENT1), the most important and famous member of NTs. We first demonstrate the labeling specificity and superiority of SAENTA-Cy5 to the antibody probe. Then, we found different assembly patterns of hENT1 on the apical and basal membranes, which are further investigated to be caused by varying associations of membrane carbohydrates, membrane classical functional domains (lipid rafts), and associated membrane proteins (EpCAM). Our work provides an efficient method for labeling hENT1, which contributes to realize fine observation of NTs. The findings on the assembly features and potential assembly mechanism of hENT1 promote a better understanding of its biofunction, which facilitates further investigations on how NTs work in the metabolism of nucleoside and nucleoside analogues.

Exogenous melatonin enhances the tolerance of tiger nut (Cyperus esculentus L.) via DNA damage repair pathway under heavy metal stress (Cd2+) at the sprout stage.

Heavy metal (HM) stress is a non-negligible abiotic stress that seriously restricts crop yield and quality, while the sprout stage is the most sensitive to stress and directly impacts the growth and development of the later stage. Melatonin (N-acetyl-5-methoxytryptamine), as an exogenous additive, enhances stress resistance due to its ability to oxidize and reduce. However, few reports on exogenous melatonin to tiger nuts under HM stress have explored whether exogenous melatonin enhances plants' resistance to heavy metals. Here, "Jisha 2″ was used as material, with a stress concentration of 5 mg/L and 100 µmol/L of CdCl2 to explore whether exogenous melatonin enhances plant resistance and molecular mechanism. The result revealed that stress limits growth, while melatonin alleviated the sprout damage under stress from the phenotypes. Moreover, stress-enhanced reactive oxygen species (ROS) accumulation and membrane lipid peroxidation, while melatonin-increased ROS reduce damage via the analysis of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) and malondialdehyde (MDA) content, hydrogen peroxide (H2O2), superoxide anion (O2-), and Electrolyte leakage (El). Further results indicated that HM leads to DNA damage while exogenous melatonin will repair the damage by analyzing random amplified polymorphic DNA (RAPD), DNA cross-linking, 8-hydroxy-20-deoxyguanine level, and relative density of apurinic sites. Furthermore, gene expression in the DNA-repaired pathway exhibited similar results. These results applied that exogenous melatonin released the hurt caused by HM stress, with DNA repair and ROS balance serving as candidate pathways. This study elucidated the mechanism of melatonin's influence and provided theoretical insights into its application in tiger nuts.

Collision Cross Section Prediction Based on Machine Learning.

Ion mobility-mass spectrometry (IM-MS) is a powerful separation technique providing an additional dimension of separation to support the enhanced separation and characterization of complex components from the tissue metabolome and medicinal herbs. The integration of machine learning (ML) with IM-MS can overcome the barrier to the lack of reference standards, promoting the creation of a large number of proprietary collision cross section (CCS) databases, which help to achieve the rapid, comprehensive, and accurate characterization of the contained chemical components. In this review, advances in CCS prediction using ML in the past 2 decades are summarized. The advantages of ion mobility-mass spectrometers and the commercially available ion mobility technologies with different principles (e.g., time dispersive, confinement and selective release, and space dispersive) are introduced and compared. The general procedures involved in CCS prediction based on ML (acquisition and optimization of the independent and dependent variables, model construction and evaluation, etc.) are highlighted. In addition, quantum chemistry, molecular dynamics, and CCS theoretical calculations are also described. Finally, the applications of CCS prediction in metabolomics, natural products, foods, and the other research fields are reflected.

Advances and challenges in ginseng research from 2011 to 2020: the phytochemistry, quality control, metabolism, and biosynthesis.

Covering: 2011 to the end of 2020Panax species (Araliaceae), particularly P. ginseng, P. quinquefolius, and P. notoginseng, have a long history of medicinal use because of their remarkable tonifying effects, and currently serve as crucial sources for various healthcare products, functional foods, and cosmetics, aside from their vast clinical preparations. The huge market demand on a global scale prompts the continuous prosperity in ginseng research concerning the discovery of new compounds, precise quality control, ADME (absorption/disposition/metabolism/excretion), and biosynthesis pathways. Benefitting from the ongoing rapid development of analytical technologies, e.g. multi-dimensional chromatography (MDC), personalized mass spectrometry (MS) scan strategies, and multi-omics, highly recognized progress has been made in driving ginseng analysis towards "systematicness, integrity, personalization, and intelligentization". Herein, we review the advances in the phytochemistry, quality control, metabolism, and biosynthesis pathway of ginseng over the past decade (2011-2020), with 410 citations. Emphasis is placed on the introduction of new compounds isolated (saponins and polysaccharides), and the emerging novel analytical technologies and analytical strategies that favor ginseng's authentic use and global consumption. Perspectives on the challenges and future trends in ginseng analysis are also presented.