Structural and signaling mechanisms of TAAR1 enabled preferential agonist design.

Trace amine-associated receptor 1 (TAAR1) senses a spectrum of endogenous amine-containing metabolites (EAMs) to mediate diverse psychological functions and is useful for schizophrenia treatment without the side effects of catalepsy. Here, we systematically profiled the signaling properties of TAAR1 activation and present nine structures of TAAR1-Gs/Gq in complex with EAMs, clinical drugs, and synthetic compounds. These structures not only revealed the primary amine recognition pocket (PARP) harboring the conserved acidic D3.32 for conserved amine recognition and "twin" toggle switch for receptor activation but also elucidated that targeting specific residues in the second binding pocket (SBP) allowed modulation of signaling preference. In addition to traditional drug-induced Gs signaling, Gq activation by EAM or synthetic compounds is beneficial to schizophrenia treatment. Our results provided a structural and signaling framework for molecular recognition by TAAR1, which afforded structural templates and signal clues for TAAR1-targeted candidate compounds design.

Polyamine metabolism controls B-to-Z DNA transition to orchestrate DNA sensor cGAS activity.

Cyclic guanosine monophosphate (GMP)-AMP (cGAMP) synthase (cGAS) is a universal double-stranded DNA (dsDNA) sensor that recognizes foreign and self-DNA in the cytoplasm and initiates innate immune responses and has been implicated in various infectious and non-infectious contexts. cGAS binds to the backbone of dsDNA and generates the second messenger, cGAMP, which activates the stimulator of interferon genes (STING). Here, we show that the endogenous polyamines spermine and spermidine attenuated cGAS activity and innate immune responses. Mechanistically, spermine and spermidine induced the transition of B-form DNA to Z-form DNA (Z-DNA), thereby decreasing its binding affinity with cGAS. Spermidine/spermine N1-acetyltransferase 1 (SAT1), the rate-limiting enzyme in polyamine catabolism that decreases the cellular concentrations of spermine and spermidine, enhanced cGAS activation by inhibiting cellular Z-DNA accumulation; SAT1 deficiency promoted herpes simplex virus 1 (HSV-1) replication in vivo. The results indicate that spermine and spermidine induce dsDNA to adopt the Z-form conformation and that SAT1-mediated polyamine metabolism orchestrates cGAS activity.

Structural basis of amine odorant perception by a mammal olfactory receptor.

Odorants are detected as smell in the nasal epithelium of mammals by two G-protein-coupled receptor families, the odorant receptors and the trace amine-associated receptors1,2 (TAARs). TAARs emerged following the divergence of jawed and jawless fish, and comprise a large monophyletic family of receptors that recognize volatile amine odorants to elicit both intraspecific and interspecific innate behaviours such as attraction and aversion3-5. Here we report cryo-electron microscopy structures of mouse TAAR9 (mTAAR9) and mTAAR9-Gs or mTAAR9-Golf trimers in complex with ß-phenylethylamine, N,N-dimethylcyclohexylamine or spermidine. The mTAAR9 structures contain a deep and tight ligand-binding pocket decorated with a conserved D3.32W6.48Y7.43 motif, which is essential for amine odorant recognition. In the mTAAR9 structure, a unique disulfide bond connecting the N terminus to ECL2 is required for agonist-induced receptor activation. We identify key structural motifs of TAAR family members for detecting monoamines and polyamines and the shared sequence of different TAAR members that are responsible for recognition of the same odour chemical. We elucidate the molecular basis of mTAAR9 coupling to Gs and Golf by structural characterization and mutational analysis. Collectively, our results provide a structural basis for odorant detection, receptor activation and Golf coupling of an amine olfactory receptor.

Auxin contributes to jasmonate-mediated regulation of abscisic acid signaling during seed germination in Arabidopsis.

Abscisic acid (ABA) represses seed germination and postgerminative growth in Arabidopsis thaliana. Auxin and jasmonic acid (JA) stimulate ABA function; however, the possible synergistic effects of auxin and JA on ABA signaling and the underlying molecular mechanisms remain elusive. Here, we show that exogenous auxin works synergistically with JA to enhance the ABA-induced delay of seed germination. Auxin biosynthesis, perception, and signaling are crucial for JA-promoted ABA responses. The auxin-dependent transcription factors AUXIN RESPONSE FACTOR10 (ARF10) and ARF16 interact with JASMONATE ZIM-DOMAIN (JAZ) repressors of JA signaling. ARF10 and ARF16 positively mediate JA-increased ABA responses, and overaccumulation of ARF16 partially restores the hyposensitive phenotype of JAZ-accumulating plants defective in JA signaling in response to combined ABA and JA treatment. Furthermore, ARF10 and ARF16 physically associate with ABSCISIC ACID INSENSITIVE5 (ABI5), a critical regulator of ABA signaling, and the ability of ARF16 to stimulate JA-mediated ABA responses is mainly dependent on ABI5. ARF10 and ARF16 activate the transcriptional function of ABI5, whereas JAZ repressors antagonize their effects. Collectively, our results demonstrate that auxin contributes to the synergetic modulation of JA on ABA signaling, and explain the mechanism by which ARF10/16 coordinate with JAZ and ABI5 to integrate the auxin, JA, and ABA signaling pathways.

PTPN9 dephosphorylates FGFR2 pY656/657 through interaction with ACAP1 and ameliorates pemigatinib effect in cholangiocarcinoma.

ABSTRACT AND AIM: Cholangiocarcinoma (CCA) is a highly aggressive and lethal cancer that originates from the biliary epithelium. Systemic treatment options for CCA are currently limited, and the first targeted drug of CCA, pemigatinib, emerged in 2020 for CCA treatment by inhibiting FGFR2 phosphorylation. However, the regulatory mechanism of FGFR2 phosphorylation is not fully elucidated. APPROACH AND RESULTS: Here we screened the FGFR2-interacting proteins and showed that protein tyrosine phosphatase (PTP) N9 interacts with FGFR2 and negatively regulates FGFR2 pY656/657 . Using phosphatase activity assays and modeling the FGFR2-PTPN9 complex structure, we identified FGFR2 pY656/657 as a substrate of PTPN9, and found that sec. 14p domain of PTPN9 interacts with FGFR2 through ACAP1 mediation. Coexpression of PTPN9 and ACAP1 indicates a favorable prognosis for CCA. In addition, we identified key amino acids and motifs involved in the sec. 14p-APCP1-FGFR2 interaction, including the "YRETRRKE" motif of sec. 14p, Y471 of PTPN9, as well as the PH and Arf-GAP domain of ACAP1. Moreover, we discovered that the FGFR2 I654V substitution can decrease PTPN9-FGFR2 interaction and thereby reduce the effectiveness of pemigatinib treatment. Using a series of in vitro and in vivo experiments including patient-derived xenografts (PDX), we showed that PTPN9 synergistically enhances pemigatinib effectiveness and suppresses CCA proliferation, migration, and invasion by inhibiting FGFR2 pY656/657 . CONCLUSIONS: Our study identifies PTPN9 as a negative regulator of FGFR2 phosphorylation and a synergistic factor for pemigatinib treatment. The molecular mechanism, oncogenic function, and clinical significance of the PTPN9-ACAP1-FGFR2 complex are revealed, providing more evidence for CCA precision treatment.

Coupling dual metal active sites and low-solvation architecture toward high-performance aqueous ammonium-ion batteries.

Aqueous rechargeable ammonium-ion batteries (AIBs) possess the characteristics of safety, low cost, environmental friendliness, and fast diffusion kinetics. However, their energy density is often limited due to the low specific capacity of cathode materials and narrow electrochemical stability windows of electrolytes. Herein, high-performance aqueous AIBs were designed by coupling Fe-substituted manganese-based Prussian blue analog (FeMnHCF) cathodes and highly concentrated NH4CF3SO3 electrolytes. In FeMnHCF, Mn3+/Mn2+-N redox reaction at high potential was introduced, and two metal active redox species of Mn and Fe were achieved. To match such FeMnHCF cathodes, highly concentrated NH4CF3SO3 electrolyte was further developed, where NH4+ ion displays low-solvation structure because of the increased coordination number of CF3SO3- anions. Furthermore, the water molecules are confined by NH4+ and CF3SO3- ions in their solvation sheath, leading to weak interaction between water molecules and thus effectively extending the voltage window of electrolyte. Consequently, the FeMnHCF electrodes present high reversibility during the charge/discharge process. Moreover, owing to a small amount of free water in concentrated electrolyte, the dissolution of FeMnHCF is also inhibited. As a result, the assembled aqueous AIBs exhibit enhanced energy density, excellent rate capability, and stable cycling behavior. This work provides a creative route to construct high-performance aqueous AIBs.

Salicylic acid regulates two photosystem II protection pathways in tomato under chilling stress mediated by ETHYLENE INSENSITIVE 3-like proteins.

Chilling stress seriously impairs photosynthesis and activates a series of molecular responses in plants. Previous studies have shown that ETHYLENE INSENSITIVE 3 (EIN3) and EIN3-like (SlEIL) proteins mediate ethylene signaling and reduce plant tolerance to freezing in tomato (Solanum lycopersicum). However, the specific molecular mechanisms underlying an EIN3/EILs-mediated photoprotection pathway under chilling stress are unclear. Here, we discovered that salicylic acid (SA) participates in photosystem II (PSII) protection via SlEIL2 and SlEIL7. Under chilling stress, the phenylalanine ammonia-lyase gene SlPAL5 plays an important role in the production of SA, which also induces WHIRLY1 (SlWHY1) transcription. The resulting accumulation of SlWHY1 activates SlEIL7 expression under chilling stress. SlEIL7 then binds to and blocks the repression domain of the heat shock factor SlHSFB-2B, releasing its inhibition of HEAT SHOCK PROTEIN 21 (HSP21) expression to maintain PSII stability. In addition, SlWHY1 indirectly represses SlEIL2 expression, allowing the expression of l-GALACTOSE-1-PHOSPHATE PHOSPHATASE3 (SlGPP3). The ensuing higher SlGPP3 abundance promotes the accumulation of ascorbic acid (AsA), which scavenges reactive oxygen species produced upon chilling stress and thus protects PSII. Our study demonstrates that SlEIL2 and SlEIL7 protect PSII under chilling stress via two different SA response mechanisms: one involving the antioxidant AsA and the other involving the photoprotective chaperone protein HSP21.

Spatial tertiary lymphoid structures imply response to anti-PD-1 plus anlotinib in advanced non-small cell lung cancer.

Despite breakthroughs of immunotherapy synergistically combined with blockade of vascular endothelial growth factor receptor, several patients with advanced non-small cell lung cancer (NSCLC) experience non-response or followed relapse. Organized lymphoid aggregates, termed tertiary lymphoid structures (TLSs), are found to be associated with improved response to immunotherapy. Here, we explore the landscapes of TLSs in tumour tissues from a real-world retrospective study. Our investigation showed that with a median follow-up of 11.2 months, the ORR was 28.6% (18/63, 95% CI 17.9-41.3) and the median PFS was 6.1 (95% CI 5.5-6.6) months in NSCLC patients treated with PD-1 blockade combined with anlotinib. By multiplex immunofluorescence (mIF) analysis, spatially, more TLSs and high CD20+ B-cell ratio in TLSs were associated with higher ORR. High density of intratumoral CD8+ T cells showed better ORR and PFS. The numbers of CD8+ T cells with a distance within 20 µm and 20-50 µm between tumour cells were higher in responders than non-responders. But responders had significantly higher TLSs within 20 µm rather than within 20-50 µm of tumour cells than non-responders. The inflamed immunophenotyping occupied higher proportions in responders and was associated with better PFS. Besides, tumour cells in non-responders were found more temporal cell-in-cell structures than responders, which could protect inner cells from T-cell attacks. Taken together, landscape of TLSs and proximity architecture may imply superior responses to PD-1 blockade combined with anlotinib for patients with advanced non-small cell lung cancer.

Isomorphous Substitution of Organic Cage Crystal by Pd Nanoclusters for Selective Hydrogenation.

For supporting active metal, the cavity confinement and mass transfer facilitation lie not in one sack, a trade-off between high activity and good stability of the catalyst is present. Porous organic cages (POCs) are expected to break the trade-off when metal particles are properly loaded. Herein, three organic cages (CC3, RCC3, and FT-RCC3) are employed to support Pd nanoclusters for catalytic hydrogenation. Subnanometer Pd clusters locate differently in different cage frameworks by using the same reverse double-solvents approach. Compared with those encapsulated in the intrinsic cavity of RCC3 and anchored on the outer surface of CC3, the Pd nanoclusters orderly assembled in FT-RCC3 crystal via isomorphous substitution exhibit superior activity, high selectivity, and good stability for semi-hydrogenation of phenylacetylene. Isomorphous substitution of FT-RCC3 crystal by Pd nanoclusters is originated from high crystallization capacity of FT-RCC3 and specific interaction of each Pd nanocluster with four cage windows. Both confinement function and H2 accumulation capacity of FT-RCC3 are fully utilized to support active Pd nanoclusters for efficient selective hydrogenation. The present results provide a new perspective to the heterogeneous catalysis field in terms of crystalizing metal nanoclusters in POC framework and outside the cage for making the best use of both parts.

Ultra-Low Alginate-Based Multifunctional Composite Binders for Enhanced Mechanical, Electrochemical, and Thermal Performance of Li-S Batteries.

The practical application of Li-S batteries, which hold great potential as energy storage devices, is impeded by various challenges, such as capacity degradation caused volume change, polysulfide shuttling, poor electrode kinetics, and safety concerns. Binder plays a crucial role in suppressing volume change of cathode side, thereby enhancing the electrochemical performance of Li-S batteries. In this research, a novel network binder (SA-Co-PEDOT) composed of sodium alginate is presented, Co2+ ions as cross-linking agent and PEDOT as an electronic conductor. The theoretical analysis and experimental testing confirm that the SA-Co-PEDOT binder with synergistic combination of catalytic center and electron transfer network effectively mitigates large volumetric changes during cycling while simultaneously enhancing electrode kinetics through controlling the deposition morphology of sulfur end product and its nucleation and dissolution. As a result, it achieves a capacity of 844 mAh g-1 after 150 cycles at 0.2 C. Moreover, the electrode with SA-Co-PEDOT binder subjected a bending test maintains a capacity of 395 mAh g-1 after 500 cycles at 0.5 C, exhibiting an impressively low decay rate of only 0.11%. Even with an ultra-low content of 2 wt.% SA-Co-PEDOT binder, the electrode still maintains a capacity of 999.7 mAh g-1 after 100 cycles at 0.5 C.

NK-like CD8 T cell: one potential evolutionary continuum between adaptive memory and innate immunity.

CD8 T cells are crucial adaptive immune cells with cytotoxicity to fight against pathogens or abnormal self-cells via major histocompatibility complex class I-dependent priming pathways. The composition of the memory CD8 T-cell pool is influenced by various factors. Physiological aging, chronic viral infection, and autoimmune diseases promote the accumulation of CD8 T cells with highly differentiated memory phenotypes. Accumulating studies have shown that some of these memory CD8 T cells also exhibit innate-like cytotoxicity and upregulate the expression of receptors associated with natural killer (NK) cells. Further analysis shows that these NK-like CD8 T cells have transcriptional profiles of both NK and CD8 T cells, suggesting the transformation of CD8 T cells into NK cells. However, the specific induction mechanism underlying NK-like transformation and the implications of this process for CD8 T cells are still unclear. This review aimed to deduce the possible differentiation model of NK-like CD8 T cells, summarize the functions of major NK-cell receptors expressed on these cells, and provide a new perspective for exploring the role of these CD8 T cells in health and disease.

RNA sequencing screening and gene function analysis uncover G protein-coupled receptor 183 as a key mediator for methionine to stimulate milk synthesis in mouse mammary epithelial cells.

Methionine (Met) can activate the mechanistic target of rapamycin (mTOR) to promote milk synthesis in mammary epithelial cells. However, it is largely unknown which G protein-coupled receptor can mediate the stimulation of Met on mTOR activation. In this study, we employed transcriptome sequencing to analyse which G protein-coupled receptors were associated with the role of Met and further used gene function study approaches to explore the role of G protein-coupled receptor 183 (GPR183) in Met stimulation on mTOR activation in HC11 cells. We identified nine G protein-coupled receptors including GPR183 whose expression levels were upregulated by Met treatment through RNA sequencing and subsequent quantitative real-time PCR analysis. Using GPR183 knockdown and overexpression technology, we demonstrate that GPR183 is a positive regulator of milk protein and fat synthesis and proliferation of HC11 cells. Met affected GPR183 expression in a dose-dependent manner, and GPR183 mediated the stimulation of Met (0·6 mM) on milk protein and fat synthesis, cell proliferation and mTOR phosphorylation and mRNA expression. The inhibition of phosphoinositide 3-kinase blocked the phosphorylation of mTOR and AKT stimulated by GPR183 activation. In summary, through RNA sequencing and gene function study, we uncover that GPR183 is a key mediator for Met to activate the phosphoinositide 3-kinase-mTOR signalling and milk synthesis in mouse mammary epithelial cells.

Changes in frailty and depressive symptoms among middle-aged and older Chinese people: a nationwide cohort study.

BACKGROUND AND AIMS: The older people bears a severe burden of disease due to frailty and depressive symptoms, however, the results of association between the two in the older Chinese people have been conflicting. Therefore, this study aimed to investigate the developmental trajectories and interactions of frailty and depressive symptoms in the Chinese middle-aged and older adults. METHODS: The study used four waves of data from 2011, 2013, 2015 and 2018 in the China Health and Retirement Longitudinal Study (CHARLS) database, focused on middle-aged and older people ≥ 45 years of age, and analyzed using latent growth models and cross-lagged models. RESULTS: The parallel latent growth model showed that the initial level of depressive symptoms had a significant positive predictive effect on the initial level of frailty. The rate of change in depressive symptoms significantly positively predicted the rate of change in frailty. The initial level of frailty had a significant positive predictive effect on the initial level of depressive symptoms, but a significant negative predictive effect on the rate of change in depressive symptoms. The rate of change in frailty had a significant positive predictive effect on the rate of change in depressive symptoms. The results of the cross-lagged analysis indicated a bidirectional causal association between frailty and depressive symptoms in the total sample population. Results for the total sample population grouped by age and gender were consistent with the total sample. CONCLUSIONS: This study recommends advancing the age of concern for frailty and depressive symptoms to middle-aged adults. Both men and women need early screening and intervention for frailty and depressive symptoms to promote healthy aging.

Effect of Early Exercise Rehabilitation Nursing on Promoting the Quality of Prognosis in Acute Myocardial Infarction Patients Following Interventional Surgery.

Background: Percutaneous coronary intervention (PCI) is a standard strategy for acute myocardial infarction (AMI). As the core content of cardiac rehabilitation, early exercise rehabilitation can promote the establishment of coronary collateral circulation, effectively increase blood flow and cardiac functional reserve by 10%-30%, raise ischemia threshold, improve myocardial metabolism and cardiac function, and reduce mortality by 37%. Objective: To probe the effect of early exercise rehabilitation nursing on cardiac function and activities of daily living in AMI patients following PCI. Design: This was a retrospective cohort study. Setting: This study was conducted in the Department of Cardiovascular Medicine, Linquan People's Hospital. Participants: A total of 106 AMI patients who underwent PCI treatment in our hospital from January 2021 to December 2022 were selected and separated into a control group (n=53) as well as a research group (n=53). Patients with AMI was consistent with relevant diagnostic criteria, and confirmed by coronary angiography and other examinations. At the same time, AMI patients with no PCI contraindications. Interventions: Patients in the control group accepted routine nursing. Patients in the research group accepted early exercise rehabilitation nursing based on routine nursing. Primary Outcome Measures: (1) heart rate, (2) blood pressure, (3) cardiac function, (4) hospital stay, (5) first defecation time, (6) 6-min-walk-test (6MWT) distance, (7) activities of daily living (ADL) index scores, (8) psychological states measured by Self-rating Anxiety Scale (SAS) as well as Self-rating Depression Scale (SDS), (9) occurrence of adverse events and (10) nursing satisfaction. Results: After nursing, the heart rate, diastolic and systolic blood pressure, and left ventricular end-diastolic diameter (LVEDD) levels in the research group were lower, and left ventricular ejection fraction (LVEF) levels were higher compared to before nursing (P < .05). Notably, compared to the control group, the research group had lower heart rate, diastolic and systolic blood pressure, and LVEDD levels, and higher LVEF levels (P < .05). The hospital stay and first defecation time in the research group were shorter than those in the control group (P < .05). Three months after nursing, the 6MWT distance in both groups was longer than 1 week after surgery, and the distance in the research group was significantly longer than in the control group (P < .05). After nursing, the ADL index scores in both groups were elevated, with the research group showing significantly higher scores compared to the control group (P < .05). After nursing, the SAS and SDS scores in both groups decreased, with the research group showing significantly lower scores compared to the control group (P < .05). The occurrence of adverse events in the research group was 18.87%, which was significantly lower than that in the control group (39.62%), with statistical significance (P < .05). The nursing satisfaction rate in the RG was 98.11%, significantly higher than in the CG (84.91%) (P < .05). Conclusion: Early rehabilitation exercise nursing applied to AMI patients can promote exercise endurance, improve cardiac function, improve negative emotions, promote self-care ability, and decline the occurrence of adverse events, the effect is better than conventional nursing. Our study shows that the early rehabilitation exercise can effectively guide clinical practice and improve the quality of clinical medical care.

Ultra-Short-Term Wind Farm Power Prediction Considering Correlation of Wind Power Fluctuation.

Accurate ultra-short-term power prediction for wind farms is challenging under rapid wind speed fluctuations, complicating production planning and power balancing. This paper proposes a new method considering spatial and temporal correlations of wind fluctuations among adjacent wind farms. The method first calculates the time difference between power fluctuations based on wind speed, direction, and relative positions, determining the prior information period. The variational Bayesian model is then used to extract implicit relationships between power fluctuations of adjacent wind farms, enabling power prediction during the prior information period. Finally, the non-prior information period is predicted to complete the ultra-short-term power prediction. Using measured data from three wind farms in Fujian Province, compared to other models, the method demonstrates improved accuracy by effectively leveraging the power fluctuation characteristics of adjacent wind farms, and it has a certain amount of generalizability.

Rabies Virus Regulates Inflammatory Response in BV-2 Cells through Activation of Myd88 and NF-κB Signaling Pathways via TLR7.

Rabies is a fatal neurological infectious disease caused by rabies virus (RABV), which invades the central nervous system (CNS). RABV with varying virulence regulates chemokine expression, and the mechanisms of signaling pathway activation remains to be elucidated. The relationship between Toll-like receptors (TLRs) and immune response induced by RABV has not been fully clarified. Here, we investigated the role of TLR7 in the immune response induced by RABV, and one-way analysis of variance (ANOVA) was employed to evaluate the data. We found that different RABV strains (SC16, HN10, CVS-11) significantly increased CCL2, CXCL10 and IL-6 production. Blocking assays indicated that the TLR7 inhibitor reduced the expression of CCL2, CXCL10 and IL-6 (p < 0.01). The activation of the Myd88 pathway in BV-2 cells stimulated by RABV was TLR7-dependent, whereas the inhibition of Myd88 activity reduced the expression of CCL2, CXCL10 and IL-6 (p < 0.01). Meanwhile, the RABV stimulation of BV-2 cells resulted in TRL7-mediated activation of NF-κB and induced the nuclear translocation of NF-κB p65. CCL2, CXCL10 and IL-6 release was attenuated by the specific NF-κB inhibitor used (p < 0.01). The findings above demonstrate that RABV-induced expression of CCL2, CXCL10 and IL-6 involves Myd88 and NF-κB pathways via the TLR7 signal.

Research on the Interaction Mechanism and Structural Changes in Human Serum Albumin with Hispidin Using Spectroscopy and Molecular Docking.

The interaction between human serum albumin (HSA) and hispidin, a polyketide abundantly present in both edible and therapeutic mushrooms, was explored through multispectral methods, hydrophobic probe assays, location competition trials, and molecular docking simulations. The results of fluorescence quenching analysis showed that hispidin quenched the fluorescence of HSA by binding to it via a static mechanism. The binding of hispidin and HSA was validated further by synchronous fluorescence, three-dimensional fluorescence, and UV/vis spectroscopy analysis. The apparent binding constant (Ka) at different temperatures, the binding site number (n), the quenching constants (Ksv), the dimolecular quenching rate constants (Kq), and the thermodynamic parameters (∆G, ∆H, and ∆S) were calculated. Among these parameters, ∆H and ∆S were determined to be 98.75 kJ/mol and 426.29 J/(mol·K), respectively, both exhibiting positive values. This observation suggested a predominant contribution of hydrophobic forces in the interaction between hispidin and HSA. By employing detergents (SDS and urea) and hydrophobic probes (ANS), it became feasible to quantify alterations in Ka and surface hydrophobicity, respectively. These measurements confirmed the pivotal role of hydrophobic forces in steering the interaction between hispidin and HSA. Site competition experiments showed that there was an interaction between hispidin and HSA molecules at site I, which situates the IIA domains of HSA, which was further confirmed by the molecular docking simulation.

HOXD8 suppresses renal cell carcinoma growth by upregulating SHMT1 expression.

Amplification of amino acids synthesis is reported to promote tumorigenesis. The serine/glycine biosynthesis pathway is a reversible conversion of serine and glycine catalyzed by cytoplasmic serine hydroxymethyltransferase (SHMT)1 and mitochondrial SHMT2; however, the role of SHTM1 in renal cell carcinoma (RCC) is still unclear. We found that low SHMT1 expression is correlated with poor survival of RCC patients. The in vitro study showed that overexpression of SHMT1 suppressed RCC proliferation and migration. In the mouse tumor model, SHMT1 significantly retarded RCC tumor growth. Furthermore, by gene network analysis, we found several SHMT1-related genes, among which homeobox D8 (HOXD8) was identified as the SHMT1 regulator. Knockdown of HOXD8 decreased SHMT1 expression, resulting in faster RCC growth, and rescued the SHMT1 overexpression-induced cell migration defects. Additionally, ChIP assay found the binding site of HOXD8 to SHMT1 promoter was at the -456~-254 bp region. Taken together, SHMT1 functions as a tumor suppressor in RCC. The transcription factor HOXD8 can promote SHMT1 expression and suppress RCC cell proliferation and migration, which provides new mechanisms of SHMT1 in RCC tumor growth and might be used as a potential therapeutic target candidate for clinical treatment.

Chromatin remodeler BRM is a key mediator of leucine-stimulated mTOR gene transcription in mouse mammary epithelial cells.

Brahma (BRM) is one of the core ATPase subunits of SWI/SNF chromatin remodeling complex, and participates in various important cellular regulatory processes. However, the role of BRM in regulating gene expression of the mechanistic target of rapamycin (mTOR) still remains unknown. In this study, we explored the effects and the corresponding molecular mechanisms of BRM on Leucine (Leu)-stimulated mTOR activation in and proliferation of a mouse mammary epithelial cell (MEC) line (HC11 cell). Initially, we found that the abundance of BRM protein in mammary gland tissue during lactation was significantly higher than that during puberty and involution. BRM knockdown inhibited HC11 cell proliferation, mRNA expression of mTOR and subsequent protein phosphorylation, whereas BRM gene activation had the opposite effect. Leu affected the level of BRM protein and mTOR phospphorylation in a dose-dependent manner, and BRM knockdown totally blocked the stimulation of Leu on mTOR mRNA expression and protein phospphorylation. ChIP-PCR detected that BRM was bound to the -4368 âˆ¼ -4591 bp site of the mTOR promoter, and ChIP-qPCR further detected that Leu stimulated BRM to bind to this site. In conclusion, these data reveal that BRM is a positive regulator of HC11 cell proliferation and mediates Leu's stimulation on mTOR gene transcription and protein phosphorylation. Our data provide a new theoretical basis for the involvement of BRM in cell proliferation and regulation of the mTOR signaling pathway.

A Robust Switchable Oil-In-Water Emulsion Stabilized by Electrostatic Repulsions between Surfactant and Similarly Charged Carbon Dots.

How to control the stability of oil-in-water (O/W) emulsions is one of the main topics for scientists working in colloidal systems. Recently, carbon dots (CDs) have received great interest as smart materials because of their excellent physicochemical properties and versatile applications. Herein, for the first time, advanced and switchable O/W emulsions are presented that are stabilized by the synergistic effect of cationic surfactant cetyltrimethylammonium bromide CTAB (emulsifier) and similarly charged CDs (stabilizer). In the formulated emulsion, the cationic surfactant molecules are adsorbed at the oil and water interface to decrease the interfacial tension and enrich the drops with a positive charge to ensure intensive electrostatic repulsions among them. On the contrary, cationic CDs are distributed in the water phase among the droplets to reduce the water secretion and prevent flocculation and droplet coalescence. The stabilizing effect is found to be universal for emulsions of a range of oil phases. Furthermore, the formulated emulsion is found to be switchable between "stable" and "unstable" modes by adding an equivalent of anionic surfactant sodium dodecyl benzene sulphonate (SDBS). The stabilized and switchable O/W emulsions are believed to have wide practical applications in water purification, pharmaceuticals, protein recognition, as well as catalysis.