Search

Integrating hydrogen evolution reaction (HER) with hydrazine oxidation reaction (HzOR) can construct novel electrolytic system and thus accomplish the energy-efficient H2 production, which necessitates exploring excellent bifunctional electrocatalysts for HER...

Adenosine is an immunosuppressive factor in the tumor microenvironment mainly through activation of the A2A adenosine receptor (A2AR), which is a mechanism hijacked by tumors to escape immune surveillance. Small-molecule A2AR antagonists are being evaluated in clinical trials as immunotherapeutic agents, but their efficacy is limited as standalone therapies. To enhance the antitumor effects of A2AR antagonists, dual-acting compounds incorporating A2AR antagonism and histone deacetylase (HDAC) inhibitory actions were designed and synthesized, based on co-crystal structures of A2AR. Compound 24e (IHCH-3064) exhibited potent binding to A2AR (Ki = 2.2 nM) and selective inhibition of HDAC1 (IC50 = 80.2 nM), with good antiproliferative activity against tumor cell lines in vitro. Intraperitoneal administration of 24e (60 mg/kg, bid) inhibited mouse MC38 tumor growth with a tumor growth inhibition rate of 95.3%. These results showed that dual-acting compounds targeting A2AR and HDAC are potentially immunotherapeutic agents that are worth further exploring.

Class F G protein-coupled receptors are characterized by a large extracellular domain (ECD) in addition to the common transmembrane domain (TMD) with seven α-helixes. For smoothened receptor (SMO), structural studies revealed dissected ECD and TMD, and their integrated assemblies. However, distinct assemblies were reported under different circumstances. Using an unbiased approach based on four series of cross-conjugated bitopic ligands, we explore the relationship between the active status and receptor assembly. Different activity dependency on the linker length for these bitopic ligands corroborates the various occurrences of SMO assembly. These results reveal a rigid "near" assembly for active SMO, which is in contrast to previous results. Conversely, inactive SMO adopts a free ECD, which would be remotely captured at "far" assembly by cholesterol. Altogether, we propose a mechanism of cholesterol flow-caused SMO activation involving an erection of ECD from far to near assembly.

The real-time identification of inflow aerodynamic parameters such as the flow separation situation, angle of attack, and inflow velocity is challenging. In this paper, a new data-driven strategy i...

The polymerization of α-olefins catalyzed by zirconium metallocene catalyst was systematically studied through experiments and density functional theory (DFT) calculations. Having achieved an agreement between theory and experiment, it was found that the effect of the catalyst ligand on the C[double bond, length as m-dash]C insertion reaction was significantly greater than that on the β-H elimination reaction. Therefore, the molecular weight of polymers can be increased by improving the activity of the C[double bond, length as m-dash]C insertion. In addition, in comparison with propylene, the chain length of α-olefins can directly affect the stereotacticity of polymerization products, owing to steric hindrance between the polymer chain and monomer.

G-protein-coupled receptors (GPCRs) play important roles in cellular functions. However, their intracellular organization is largely unknown. Through investigation of the cannabinoid receptor 1 (CB1), we discovered periodically repeating clusters of CB1 hotspots within the axons of neurons. We observed these CB1 hotspots interact with the membrane-associated periodic skeleton (MPS) forming a complex crucial in the regulation of CB1 signaling. Furthermore, we found that CB1 hotspot periodicity increased upon CB1 agonist application, and these activated CB1 displayed less dynamic movement compared to non-activated CB1. Our results suggest that CB1 forms periodic hotspots organized by the MPS as a mechanism to increase signaling efficacy upon activation., Despite the importance of G-protein-coupled receptors in many cellular functions, their intracellular organisation is largely unknown. The authors identified periodically repeating clusters of cannabinoid receptor 1 hotspots within neuronal axons that are dynamically regulated by CB1 agonists.

Subtype selectivity and functional bias are vital in current drug discovery for G protein-coupled receptors (GPCRs) as selective and biased ligands are expected to yield drug leads with optimal on-target benefits and minimal side-effects. However, structure-based design and medicinal chemistry exploration remain challenging in part because of highly conserved binding pockets within subfamilies. Herein, we present an affinity mass spectrometry approach for screening herbal extracts to identify active ligands of a GPCR, the 5-HT2C receptor. Using this method, we discovered a naturally occurring aporphine 1857 that displayed strong selectivity for activating 5-HT2C without activating the 5-HT2A or 5-HT2B receptors. Remarkably, this novel ligand exhibited exclusive bias toward G protein signaling for which key residues were identified, and it showed comparable in vivo efficacy for food intake suppression and weight loss as the antiobesity drug, lorcaserin. Our study establishes an efficient approach to discovering novel GPCR ligands by exploring the largely untapped chemical space of natural products.

ObjectiveInfection is a major cause of death in patients with SLE. This study aimed to explore the infection rate in patients with SLE receiving a low dose of intravenous cyclophosphamide (IV-CYC).MethodsClinical parameters of 1022 patients with SLE from 24 hospitals in China were collected. Patients were divided into the short-interval and lower-dose (SILD, 400 mg every 2 weeks) IV-CYC group and the high-dose (HD, 500 mg/m2of body surface area every month) IV-CYC group. The clinical data and infection rate between the two groups were compared.ResultsCompared with HD IV-CYC, the infection rate of the SILD IV-CYC group was significantly lower (13.04% vs 22.27%, p=0.001). Respiratory tract infection (10.28% vs 15.23%, p=0.046) and skin/soft tissue infection (1.78% vs 4.3%, p=0.040) were significantly decreased in the SILD IV-CYC group. Moreover, infections occurred most likely in patients with SLE with leucopenia (OR 2.266, 95% CI 1.322 to 3.887, p=0.003), pulmonary arterial hypertension (OR 2.756, 95% CI 1.249 to 6.080, p=0.012) and >15 mg/day of glucocorticoid (OR 2.220, 95% CI 1.097 to 4.489, p=0.027).ConclusionsSILD IV-CYC showed a lower frequency of infection events than high-dose IV-CYC in patients with SLE.

Azobenzene-embedded photoswitchable ligands are the widely used chemical tools in photopharmacological studies. Current approaches to azobenzene introduction rely mainly on the isosteric replacement of typical azologable groups. However, atypical scaffolds may offer more opportunities for photoswitch remodeling, which are chemically in an overwhelming majority. Herein, we investigate the rational remodeling of atypical scaffolds for azobenzene introduction, as exemplified in the development of photoswitchable ligands for the cannabinoid receptor 2 (CB2). Based on the analysis of residue-type clusters surrounding the binding pocket, we conclude that among the three representative atypical arms of the CB2 antagonist, AM10257, the adamantyl arm is the most appropriate for azobenzene remodeling. The optimizing spacer length and attachment position revealed AzoLig 9 with excellent thermal bistability, decent photopharmacological switchability between its two configurations, and high subtype selectivity. This structure-guided approach gave new impetus in the extension of new chemical spaces for tool customization for increasingly diversified photo-pharmacological studies and beyond.

Two novel nortriterpenoids, cyclopalitins A and B (1 and 2), were isolated from aerial parts of Cyclocarya paliurus. Their structures were elucidated on the basis of extensive spectroscopic analyses including high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), 1D NMR and 2D NMR. Compounds 1 and 2 were tested for their cytotoxicity towards B16F10. The results revealed that they didn’t show cytotoxic activity against B16F10 with 10 ug/mL treatment for 48 h.

The present study describes the preparation of a dodecapeptide YHWYGYTPQNVI (GE11)‑conjugated liposome bound with polyethylene glycol to enhance the therapeutic effect of resveratrol (RSV) in head and neck cancer cells. The results indicated that (RSV)‑loaded GE11‑conjugated liposomes (RSV‑GL) exhibited a high entrapment efficiency of >95%, with an active drug loading level of 19.5% w/w. Release kinetics revealed that RSV was released in a slow and sustained manner from the RSV‑GL and RSV‑loaded liposome (RSV‑L) nanoparticulate systems. The epidermal growth factor receptor (EGFR)‑overexpressing squamous cell carcinoma HN cells specifically internalized GE11 surface‑conjugated liposome in a manner that was markedly increased compared with that of the non‑targeted carrier. Consistently, RSV‑GL exhibited a significantly increased cytotoxic effect compared with that of the non‑targeted nanoparticles. Notably, RSV‑GL induced significantly increased proportions of early (~60%) and late (~10%) apoptotic cells in head and neck cancer cell populations. To the best of our knowledge, the application and development of EGFR‑targeted peptide‑conjugated liposome system for RSV delivery has not been studied previously in the treatment of head and neck cancer. In addition, RSV‑GL exhibited the greatest antitumor efficacy compared with any other group. RSV‑GL exhibited a 2‑fold decrease in tumor volume compared with the free RSV and a 3‑fold decrease in volume compared with the control. Overall, the nanomedicine strategy described in the present study may potentially advance the chemotherapy‑based treatment of head and neck cancer, with promising applications in other EGFR‑overexpressing tumors.

Prophylactic vaccines against SARS-CoV-2 have been extensively developed globally to overcome the COVID-19 pandemic. However, recently emerging SARS-CoV-2 variants B.1.1.7 and B.1.351 limit the vaccine protection effects and successfully escape antibody cocktail treatment. Herein, based on our previously engineered adeno-associated viral (AAV) vector, AAV-ie, and systematic immunogen screening, we developed an AAV-ie-S1 vaccine with thermostability, high efficiency, safety, and single-dose vaccination advantage. Importantly, the AAV-ie-S1 immune sera efficiently neutralize B.1.1.7 and B.1.351, indicating a potential to circumvent the spreading of SARS-CoV-2.

Peanut varieties have their own distinct characteristics, which also affect the properties of the processed-products. Knowledge on these effects can assist peanut processors to select certain varieties for specific products. Therefore, the multivariate relationships between the quality traits of peanut kernels and their peanut butters were explored in this study. Peanut butters were manufactured from forty peanut varieties with detailed component analysis. The volatile compounds, colour, texture, rheology, and particle size distributions of peanut butters and their relationships with peanut varieties were comprehensively analysed. The results showed that peanut butters prepared from varieties with lower fat, higher protein, and higher sucrose contents have higher firmness, yield stress, and G ′ values. It was also suggested that amino acids likely play a major role in the formation of the distinct peanut butter aroma and colour. This research study provided a detailed analysis approach that can be used by processing enterprises to select the most suitable varieties to produce peanut butters that address different commercial needs.

G-protein-coupled receptors (GPCRs) play important roles in cellular functions. However, their intracellular organization is largely unknown. Through investigation of the cannabinoid receptor 1 (CB1), we discovered periodically repeating clusters of CB1 hotspots within the axons of neurons. We observed these CB1 hotspots interact with the membrane-associated periodic skeleton (MPS) forming a complex crucial in the regulation of CB1 signaling. Furthermore, we found that CB1 hotspot periodicity increased upon CB1 agonist application, and these activated CB1 displayed less dynamic movement compared to non-activated CB1. Our results suggest that CB1 forms periodic hotspots organized by the MPS as a mechanism to increase signaling efficacy when being activated.

The quality traits of peanuts (Arachis hypogaea L.) are fundamental to the whole peanut industry. However, many common analyses require the sample to be brought to the laboratory. Therefore, this research explores the feasibility of portable near-infrared spectroscopy combined with a single detection accessory to analyse the composition of peanuts in a single seed level quantitatively. The single detection accessory was specifically designed for spectral data collection considering the internal and external characteristics of single peanuts. Confocal laser scanning microscopy revealed that the oil body and protein body were randomly distributed at cell of single peanuts. The external characteristics of single peanuts were also determined and considered length (11.32–24.25 mm) and width (7.49–12.25 mm). The chemical compositional data (i.e. fat, sucrose, protein, and 16 amino acids) were determined by conventional wet-chemical methods and showed large variation. Principal component analysis on the compositional data showed that peanuts with higher fat contents usually have higher hydrophobic amino acids contents, lower sucrose contents, and lower protein contents. The composition prediction models of single peanuts were estimated using partial least squares regression models that were integrated with different spectral pre-treatments and validated by external sets. The results showed that the prediction models have good performance with a correlation coefficient above 0.88 (calibration) and 0.83 (prediction) and a residual prediction deviation above 1.5 except for a few indicators. Overall, the portable near-infrared spectroscopy offered reliable methods to assess the major components and amino acids quantitatively in a single peanut, which will improve the raw material quality in the peanut industry through the simultaneous and short-term determination of multiple indicators.

G protein-coupled receptors (GPCRs) constitute the largest human protein family with over 800 members, which are implicated in many important medical conditions. Serotonin receptors belong to the aminergic GPCR subfamily and play important roles in physiological and psychological activities. Structural biology studies have revealed the structures of many GPCRs in atomic details and provide the basis for the identification and investigation of the potential ligands, which interact with and modulate the receptors. Here, an integrative approach combining a focused target-specific natural compound library, a thermal-shift-based screening method, affinity mass spectrometry, molecular docking, and in vitro as well as in vivo functional assay, was applied to identify (–)-crebanine and several other aporphine alkaloids as initial hits for a human serotonin receptor subtype, the 5-HT2C receptor. Further studies illuminated key features of their binding affinity, downstream signaling and tissue reaction, providing a molecular explanation for the interaction between (–)-crebanine and human 5-HT2C receptor.

Subtype selectivity and functional bias are vital in current drug discovery for G protein-coupled receptors (GPCRs) as selective and biased ligands are expected to yield drug leads with optimal on-target benefits and minimal side-effects. However, structure-based design and medicinal chemistry exploration remain challenging in part because of highly conserved binding pockets within subfamilies. Herein, we present an affinity mass spectrometry approach for screening herbal extracts to identify active ligands of a GPCR, the 5-HT2C receptor. Using this method, we discovered a naturally occurring aporphine 1857 that displayed strong selectivity for activating 5-HT2C without activating the 5-HT2A or 5-HT2B receptors. Remarkably, this novel ligand exhibited exclusive bias towards G protein signaling for which key residues were identified, and it showed comparable in vivo efficacy for food intake suppression and weight loss as the anti-obesity drug, lorcaserin. Our study establishes an efficient approach to discovering novel GPCR ligands by exploring the largely untapped chemical space of natural products.

Human adipose-derived stem cells (hADSCs) are increasingly presumed to be a prospective stem cell source for cell replacement therapy in various degenerative and/or traumatic diseases. The potential of trans-differentiating hADSCs into motor neuron cells indisputably provides an alternative way for spinal cord injury (SCI) treatment. In the present study, a stepwise and efficient hADSC trans-differentiation protocol with retinoic acid (RA), sonic hedgehog (SHH), and neurotrophic factors were developed. With this protocol hADSCs could be converted into electrophysiologically active motoneuron-like cells (hADSC-MNs), which expressed both a cohort of pan neuronal markers and motor neuron specific markers. Moreover, after being primed for neuronal differentiation with RA/SHH, hADSCs were transplanted into SCI mouse model and they survived, migrated, and integrated into injured site and led to partial functional recovery of SCI mice. When ablating the transplanted hADSC-MNs harboring HSV-TK-mCherry overexpression system with antivirial Ganciclovir (GCV), functional relapse was detected by motor-evoked potential (MEP) and BMS assays, implying that transplanted hADSC-MNs participated in rebuilding the neural circuits, which was further confirmed by retrograde neuronal tracing system (WGA). GFP-labeled hADSC-MNs were subjected to whole-cell patch-clamp recording in acute spinal cord slice preparation and both action potentials and synaptic activities were recorded, which further confirmed that those pre-conditioned hADSCs indeed became functionally active neurons in vivo. As well, transplanted hADSC-MNs largely prevented the formation of injury-induced cavities and exerted obvious immune-suppression effect as revealed by preventing astrocyte reactivation and favoring the secretion of a spectrum of anti-inflammatory cytokines and chemokines. Our work suggests that hADSCs can be readily transformed into MNs in vitro, and stay viable in spinal cord of the SCI mouse and exert multi-therapeutic effects by rebuilding the broken circuitry and optimizing the microenvironment through immunosuppression.