Single hormone or synthetic agonist induces Gs/Gi coupling selectivity of EP receptors via distinct binding modes and propagating paths.

To accomplish concerted physiological reactions, nature has diversified functions of a single hormone at at least two primary levels: 1) Different receptors recognize the same hormone, and 2) different cellular effectors couple to the same hormone-receptor pair [R.P. Xiao, Sci STKE 2001, re15 (2001); L. Hein, J. D. Altman, B.K. Kobilka, Nature 402, 181-184 (1999); Y. Daaka, L. M. Luttrell, R. J. Lefkowitz, Nature 390, 88-91 (1997)]. Not only these questions lie in the heart of hormone actions and receptor signaling but also dissecting mechanisms underlying these questions could offer therapeutic routes for refractory diseases, such as kidney injury (KI) or X-linked nephrogenic diabetes insipidus (NDI). Here, we identified that Gs-biased signaling, but not Gi activation downstream of EP4, showed beneficial effects for both KI and NDI treatments. Notably, by solving Cryo-electron microscope (cryo-EM) structures of EP3-Gi, EP4-Gs, and EP4-Gi in complex with endogenous prostaglandin E2 (PGE2)or two synthetic agonists and comparing with PGE2-EP2-Gs structures, we found that unique primary sequences of prostaglandin E2 receptor (EP) receptors and distinct conformational states of the EP4 ligand pocket govern the Gs/Gi transducer coupling selectivity through different structural propagation paths, especially via TM6 and TM7, to generate selective cytoplasmic structural features. In particular, the orientation of the PGE2 ω-chain and two distinct pockets encompassing agonist L902688 of EP4 were differentiated by their Gs/Gi coupling ability. Further, we identified common and distinct features of cytoplasmic side of EP receptors for Gs/Gi coupling and provide a structural basis for selective and biased agonist design of EP4 with therapeutic potential.

Optimizing Integrated-Loss Capacities via Asymmetric Electronic Environments for Highly Efficient Electromagnetic Wave Absorption.

Asymmetric electronic environments based on microscopic-scale perspective have injected infinite vitality in understanding the intrinsic mechanism of polarization loss for electromagnetic (EM) wave absorption, but still exists a significant challenge. Herein, Zn single-atoms (SAs), structural defects, and Co nanoclusters are simultaneously implanted into bimetallic metal-organic framework derivatives via the two-step dual coordination-pyrolysis process. Theoretical simulations and experimental results reveal that the electronic coupling interactions between Zn SAs and structural defects delocalize the symmetric electronic environments and generate additional dipole polarization without sacrificing conduction loss owing to the compensation of carbon nanotubes. Moreover, Co nanoclusters with large nanocurvatures induce a strong interfacial electric field, activate the superiority of heterointerfaces and promote interfacial polarization. Benefiting from the aforementioned merits, the resultant derivatives deliver an optimal reflection loss of -58.9 dB and the effective absorption bandwidth is 5.2 GHz. These findings provide an innovative insight into clarifying the microscopic loss mechanism from the asymmetric electron environments viewpoint and inspire the generalized electronic modulation engineering in optimizing EM wave absorption.

Chiral-Achiral Cations Intercalation Induced Lead-Free Chiral-Polar Hybrid Perovskites Enable Self-Powered X-Ray and Ultraviolet-Visible-Near-Infrared Photo Detection.

Lead halide hybrid perovskites have made great progress in direct X-ray detection and broadband photodetection, but the existence of toxic Pb and the demand for external operating voltage have severely limited their further applications and operational stability improvements. Therefore, exploring "green" lead-free hybrid perovskite that can both achieve X-ray detection and broadband photodetection without external voltage is of great importance, but remains severely challenging. Herein, using centrosymmetric (BZA)3BiI6 (1, BZA = benzylamine) as a template, a pair of chiral-polar lead-free perovskites, (BZA)2(R/S-PPA)BiI6 (2-R/S, R/S-PPA = (R/S)-1-Phenylpropylamine) are successfully obtained by introducing chiral aryl cations of (R/S)-1-Phenylpropylamine. Compared to 1, chiral-polar 2-R presents a significant irradiation-responsive bulk photovoltaic effect (BPVE) with an open circuit photovoltage of 0.4 V, which enables it with self-powered X-ray, UV-vis-NIR broadband photodetection. Specifically, 2-R device exhibits an ultralow detection limit of 18.5 nGy s-1 and excellent operational stability. Furthermore, 2-R as the first lead-free perovskite achieves significant broad-spectrum (377-940 nm) photodetection via light-induced pyroelectric effect. This work sheds light on the rational crystal reconstruction engineering and design of "green" hybrid perovskite toward high-demanded self-powered radiation detection and broadband photodetection.

Ore improver additions alter livestock manure compost ecosystem C:N:P stoichiometry.

Deciphering the pivotal components of nutrient metabolism in compost is of paramount importance. To this end, ecoenzymatic stoichiometry, enzyme vector modeling, and statistical analysis were employed to explore the impact of exogenous ore improver on nutrient changes throughout the livestock composting process. The total phosphorus increased from 12.86 to 18.72 g kg-1, accompanied by a marked neutralized pH with ore improver, resulting in the Carbon-, nitrogen-, and phosphorus-related enzyme activities decreases. However, the potential C:P and N:P acquisition activities represented by ln(ßG + CB): ln(ALP) and ln(NAG): ln(ALP), were increased with ore improver addition. Based on the ecoenzymatic stoiometry theory, these changes reflect a decreasing trend in the relative P/N limitation, with pH and total phosphorus as the decisive factors. Our study showed that the practical employment of eco stoichiometry could benefit the manure composting process. Moreover, we should also consider the ecological effects from pH for the waste material utilization in sustainable agriculture.

Prognostic value and potential mechanism of cellular senescence and tumor microenvironment in hepatocellular carcinoma: Insights from bulk transcriptomics and single-cell sequencing analysis.

The high mortality rate and postoperative recurrence of hepatocellular carcinoma (HCC) contribute to the burden on society and healthcare. The prognostic value and underlying mechanisms of cellular senescence and tumor microenvironment (TME) in HCC remain unclear. Bulk transcriptomic data were obtained from 368 HCC samples in The Cancer Genome Atlas-liver hepatocellular carcinoma cohort and 64 samples from the GSE116174 dataset. Single-cell RNA sequencing (scRNA-seq) data of HCC were obtained from the GSE149614 dataset, including 18 tumor samples from 10 patients. Prognosis-related cellular senescence genes and immune cells were identified through univariate analysis. Least absolute shrinkage and selection operator regression analysis was performed to construct the CellAge score and TME score, both of which were identified as independent prognostic factors for HCC based on multivariate Cox analysis. The combined CellAge and TME scores showed improved prognostic stratification for HCC patients, as confirmed by multivariate Cox analysis (p < .001). The gene set enrichment analysis (GSEA) revealed enrichment of the extracellular matrix receptor interaction signaling pathway in the group with high CellAge scores and low TME scores, which exhibited a worse prognosis. Single-cell sequencing results revealed higher expression activity of the cAMP response element modulator (CREM) extended transcription factor in HCC cells and most immune cells, indicating its involvement in TME remodeling. Finally, the tumor immune dysfunction and exclusion (TIDE) analysis demonstrated that the combined scores could predict the outcomes of immune therapy in patients with HCC. In conclusion, cellular senescence contributes to TME remodeling in HCC, and the developed CellAge and TME scores serve as independent prognostic factors and predictors of immune therapy in HCC.

SIK2-positive tumor epithelial cells in breast cancer maybe potential anti-cancer messengers: A systematic analysis from a single-cell perspective.

Breast cancer is the most common malignancy in the world and one of the leading causes of cancer death, which is a heterogeneous disease involving genetic and environmental factors. Breast cancer stem cells (BCSCs) are the main players in the aggressiveness of different tumors, at the same time, these cells are the main challenge for cancer treatment. There are multiple treatment options for breast cancer (BC) patients and the lack of understanding of prognostic and predictive biomarkers for breast cancer is a potential research direction for us to develop better treatments in the future. In this paper, we conducted a correlation analysis between SIK2 and clinical traits by searching numerous BRCA datasets in the GEO database. The model was constructed and validated by incorporating tumor samples from the TCGA-BRCA cohort. Surprisingly, we found differential expression of SIK2 gene in individual tumor samples from the UCSC database. Subsequently, we found significantly high expression of SIK2 in epithelial cells by comparing the differential expression of SIK2 in different cell subpopulations and performed subsequent immune infiltration and pathway correlation analysis. Differential genes in SIK2+ epithelial cells, which may be potential therapeutic targets for breast cancer. In conclusion, our results suggest that SIK2 may be a potential prognostic and predictive biomarker that could serve as an oncogenic messenger for breast cancer. This discovery of SIK2 may provide more valuable references for potential therapeutic tools for breast cancer.

Zafirlukast inhibits the growth of lung adenocarcinoma via inhibiting TMEM16A channel activity.

Lung cancer has the highest mortality among cancers worldwide due to its high incidence and lack of the effective cures. We have previously demonstrated that the membrane ion channel TMEM16A is a potential drug target for the treatment of lung adenocarcinoma and have identified a pocket of inhibitor binding that provides the basis for screening promising new inhibitors. However, conventional drug discovery strategies are lengthy and costly, and the unpredictable side effects lead to a high failure rate in drug development. Therefore, finding new therapeutic directions for already marketed drugs may be a feasible strategy to obtain safe and effective therapeutic drugs. Here, we screened a library of over 1400 Food and Drug Administration-approved drugs through virtual screening and activity testing. We identified a drug candidate, Zafirlukast (ZAF), clinically approved for the treatment of asthma, that could inhibit the TMEM16A channel in a concentration-dependent manner. Molecular dynamics simulations and site-directed mutagenesis experiments showed that ZAF can bind to S387/N533/R535 in the nonselective inhibitor binding pocket, thereby blocking the channel pore. Furthermore, we demonstrate ZAF can target TMEM16A channel to inhibit the proliferation and migration of lung adenocarcinoma LA795 cells. In vivo experiments showed that ZAF can significantly inhibit lung adenocarcinoma tumor growth in mice. Taken together, we identified ZAF as a novel TMEM16A channel inhibitor with excellent anticancer activity, and as such, it represents a promising candidate for future preclinical and clinical studies.

Divergence of active site motifs among different classes of Populus glutaredoxins results in substrate switches.

Enzymes are essential components of all biological systems. The key characteristics of proteins functioning as enzymes are their substrate specificities and catalytic efficiencies. In plants, most genes encoding enzymes are members of large gene families. Within such families, the contributions of active site motifs to the functional divergence of duplicate genes have not been well elucidated. In this study, we identified 41 glutaredoxin (GRX) genes in the Populus trichocarpa genome. GRXs are ubiquitous enzymes in plants that play important roles in developmental and stress tolerance processes. In poplar, GRX genes were divided into four classes based on clear differences in gene structure and expression pattern, subcellular localization, enzymatic activity, and substrate specificity of the encoded proteins. Using site-directed mutagenesis, this study revealed that the divergence of the active site motif among different classes of GRX proteins resulted in substrate switches and thus provided new insights into the molecular evolution of these important plant enzymes.

Disturbing NLRP3 acetylation and inflammasome assembly inhibits androgen receptor-promoted inflammatory responses and prostate cancer progression.

Chronic inflammation is one of the definite factors leading to the occurrence and development of tumors, including prostate cancer (PCa). The androgen receptor (AR) pathway is essential for PCa tumorigenesis and inflammatory response. However, little is known about the AR-regulated NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) inflammasome pathway in human PCa. In this study, we explored the expression of inflammatory cytokine and AR in high-grade PCa and observed that NLRP3 inflammasome-associated genes were upregulated in high-grade PCa compared with that in low-grade PCa and benign prostatic hyperplasia and were associated with AR expression. In addition, we identified circAR-3-a circRNA derived from the AR gene-which is involved in the AR-regulated inflammatory response and cell proliferation by activating the NLRP3 inflammatory pathway. While circAR-3 overexpression promoted cell proliferation and the inflammatory response, its depletion induced opposite effects. Mechanistically, we noted that circAR-3 mediated the acetylation modification of NLRP3 by KAT2B and then promoted NLRP3 inflammasome complex subcellular distribution and assembly. Disturbing NLRP3 acetylation or blocking inflammasome assembly with an inhibitor suppressed the progression of PCa xenograft tumors. Our findings provide the first evidence that targeting NLRP3 acetylation or inflammasome assembly may be effective in inhibiting PCa progression.

[Arsenic speciation and valence].

As arsenic widely exists in nature and has been used in the pharmaceutical preparations, the traditional Chinese medicine(TCM) with arsenic include realgar(As_2S_2 or As_4S_4), orpiment(As_2S_3), and white arsenic(As_2O_3). Among the above representative medicine, the TCM compound formulas with realgar are utilized extensively. Just in Chinese Pharmacopoeia(2020 edition), there are 37 Chinese patent medicines including realgar. The traditional element analysis focuses on the detection of the total amount of elements, which neglects the study on the speciation and valence of elements. The activity, toxicity, bioavailability, and metabolic pathways of arsenic in vivo are closely related to the existence of its form, and different forms of arsenic have different effects on organisms. Therefore, the study on the speciation and valence of arsenic is of great importance for arsenic-containing TCMs and their compound formulas. This paper reviewed four aspects of the speciation and valence of arsenic, including property, absorption and metabolism, toxicity, and analytical assay.

[Varieties systematization and standards status analysis of fermented Chinese medicine].

Fermented Chinese medicine has long been used. Amid the advance for preservation of experience, the connotation of fermented Chinese medicine has been enriched and improved. However, fermented Chinese medicine prescriptions generally contain a lot of medicinals. The fermentation process is complicated and the conventional fermentation conditions fail to be strictly controlled. In addition, the judgment of the fermentation end point is highly subjective. As a result, quality of fermented Chinese medicine is of great difference among regions and unstable. At the moment, the quality standards of fermented Chinese medicine are generally outdated and different among regions, with simple quality control methods and lacking objective safe fermentation-specific evaluation indictors. It is difficult to comprehensively evaluate and control the quality of fermented medicine. These problems have aroused concern in the industry and also affected the clinical application of fermented Chinese medicine. This article summarized and analyzed the application, quality standards, and the modernization of fermentation technology and quality control methods of fermented Chinese medicine and proposed suggestions for improving the quality standards of the medicine, with a view to improving the overall quality of it.

Theaflavin binds to a druggable pocket of TMEM16A channel and inhibits lung adenocarcinoma cell viability.

As a calcium-activated chloride channel regulated by the intracellular Ca2+ concentration and membrane potential, TMEM16A has attracted considerable attention and has been proposed as a novel anticancer drug target. We have previously reported that the pocket above the ion conductance pore could be a nonselective inhibitor-binding pocket. However, whether this pocket is druggable remains unexplored. In this study, we performed virtual screening to target the presumed inhibitor-binding pocket and identified a highly effective TMEM16A inhibitor, theaflavin (TF: a tea polyphenol in black tea). Molecular dynamics simulations revealed that theaflavin adopts a "wedge insertion mode" to block the ion conduction pore and induces pore closure. Moreover, the binding mode showed that the TF pedestal plays an important role in pore blockade, and R515, R535, T539, K603, E623, and E633 were determined to be most likely to interact directly with the pedestal. Mutagenesis experiment results corroborated the mechanism through which TF binds to this pocket. Combined with the quantitative calculation results, our data indicated that the three hydroxyl groups on the pedestal may be the most crucial pharmacophores for TMEM16A inhibition by TF. Finally, antitumor experiments revealed that TF could target TMEM16A to inhibit the proliferation and migration of LA795 cells, indicating the potential therapeutic effect of TF on the growth of lung adenocarcinoma with high TMEM16A expression. The successful application of drug screening strategies based on this binding pocket highlights new directions for discovering superior modulators and contributes to the development of novel therapeutics for lung adenocarcinoma.

Predictive Model of Early Death of Resectable Pancreatic Ductal Adenocarcinoma After Curative Resection: A SEER-Based Study.

OBJECTIVE: This study aims to determine the factors that predict early death and establish a predictive model for early death by analyzing clinical characteristics of patients with resectable pancreatic ductal adenocarcinoma (R-PDAC) who die early after radical surgery. MATERIALS AND METHODS: This was a retrospective study of patients who underwent radical surgical resection for R-PDAC in the Surveillance, Epidemiology, and End Results (SEER) database. Patients with overall survival ≤ 12 months were assigned as early death group and above 1 year as the late death group. Univariate and multivariate logistic regression was conducted to identify factors significantly associated with early death. An early death predictive model was constructed based on the identified independent risk factors. RESULTS: A total of 9695 patients were analyzed, and the total incidence of early death was 30.72%. Multivariable analysis showed that factors significantly associated with early death included age at diagnosis, race, marital status, tumor location, tumor size, tumor grade, number of positive lymph nodes, number of examined lymph nodes, positive lymph node ratio, chemotherapy, and radiotherapy. The predictive model showed good discrimination with a C-index of 0.722 (95% confidence interval: 0.711-0.733) and convincing calibration. CONCLUSIONS: We developed a predictive model that may be easily applied to patients with R-PDAC after radical resection to predict the chance of death within 1 year. For patients with high risk of early death, neoadjuvant therapy should be considered. Even after radical resection, more aggressive adjuvant chemotherapy (with or without combined radiotherapy) must be used to minimize the chance of early death.

[Preparation regularity of Chinese patent medicine in Chinese Pharmacopoeia (2020 edition, Vol.â )].

Chinese Pharmacopoeia is an important part of drug standards in China, and it is also a legal basis that must be strictly followed in drug development, production, operation, application, and management. The information on prescriptions, preparation methods, properties, identification, inspection, content determination, functions and indications, usage and dosage, precautions, specifications, and storage of Chinese patent medicine preparations included in the Chinese Pharmacopoeia(Vol.Ⅰ) was clarified. The "Preparation Method" section describes the preparation process of Chinese patent medicine from decoction pieces to finished preparations in detail and specifies the preparation production methods and parameters, which has a good guiding and standardizing effect on the production of Chinese patent medicine in China. The present study summarized the preparation methods of Chinese patent medicine preparations and single drug preparations contained in the Chinese Pharmacopoeia(2020 edition, Vol.Ⅰ) in stages and analyzed the common preparation methods and technical parameters of Chinese patent medicine preparations, which is helpful to understand the current situation of Chinese patent medicine production technology in China and can provide references for the development of new Chinese medicine, the transformation of large varieties of Chinese patent medicine, and the optimization of preparation process of Chinese patent medicine in the market.

[Study on characteristic chromatogram and content determination of Wuzhuyu Decoction reference sample].

In this study, the critical quality attributes of Wuzhuyu Decoction reference sample were explored by using characteristic chromatogram, index component content and dry extract rate as indexes.The dissemination relationship of quantity value between medicinal materials-decoction pieces-reference sample was investigated to preliminarily formulate the quality standard of the reference sample.The characteristic chromatogram of 15 batches of Wuzhuyu Decoction was established by high performance liquid chromatography(HPLC) and the similarity analysis was conducted.Common peaks were demarcated and assigned to medicinal materials.Moreover, quantitative determination of limonin, evodiamine, rutaecarpine and ginsenoside Rb_1 of Wuzhuyu Decoction were performed.The dissemination of quantity value was explored combined with dry extract rate, similarity of characteristic chromatogram and transfer rate of index component content.A total of 18 common peaks were identified in the corresponding materials of Wuzhuyu Decoction reference sample, with the similarity of characteristic chromatogram greater than 0.9, and Fructus Evodiae, Radix Ginseng, Rhizoma Zingiberis Recens and Fructus Jujubae contributed 9, 5, 8 and 2 chromatographic peaks, respectively.The index component content of corresponding materials and the transfer rates of medicinal materials-decoction pieces and decoction pieces-reference sample of different batches of Wuzhuyu Decoction reference sample were as follows: the content of limonin was 0.16%-0.51%, and the transfer rates were 83.66%-115.60% and 38.54%-54.58%, respectively; the content of evodiamine was 0.01%-0.11%, the transfer rated were 80.80%-116.15% and 3.23%-12.93%, respectively; the content of rutaecarpine was 0.01%-0.05%, the transfer rates were 84.33%-134.53% and 5.72%-21.24%, respectively; the content of ginsenoside Rb_1 was 0.06%-0.11%, and the transfer rates were 90.00%-96.92% and 32.45%-67.24%, respectively.The dry extract rate of the whole prescription was 22.58%-29.89%.In this experiment, the dissemination of quantity value of Wuzhuyu Decoction reference sample was analyzed by the combination of characteristic chromatogram, index component content and dry extract rate.A scientific and stable quality evaluation method of the reference sample was preliminarily established, which provided basis for the subsequent development of Wuzhuyu Decoction and the quality control of related preparations.

Profile and outcome of receptor conversion in breast cancer metastases: a nation-wide multicenter epidemiological study.

Although receptor status including estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) of the primary breast tumors was related to the prognosis of breast cancer patients, little information is yet available on whether patient management and survival are impacted by receptor conversion in breast cancer metastases. Using data from the nation-wide multicenter clinical epidemiology study of advanced breast cancer in China (NCT03047889), we report the situation of retesting ER, PR and HER2 status for breast cancer metastases and evaluate the patient management and prognostic value of receptor conversion. In total, 3295 patients were analyzed and 1583 (48.0%) patients retesting receptor status for metastasis. Discordance in one or more receptors between the primary and the metastatic biopsy was found in 37.7% of women. Patients who remained hormone receptor (HR) positive in their metastases had similar progression-free survival of first-line and second-line treatment compared to patients with HR conversion (P > .05). In multivariate analysis, patients who showed ER conversion from negative to positive had longer disease-free survival (DFS) than patients who remained negative in their metastases (hazard ratio, 2.05; 95% confidence interval [CI], 1.45-2.90; P < .001). Patients with PR remained positive and had longer DFS than patients with PR conversion from negative to positive (hazard ratio, 0.56; 95% CI, 0.38-0.83; P = .004). Patients with PR conversion have shorter overall survival than patients with PR remained positive or negative (P = .016 and P = .041, respectively). Our findings showed that the receptors' conversions were common in metastatic breast cancer, and the conversion impacted the survival.

The reasons and countermeasures of Bladder Rupture caused by Transurethral Clot Evacuation.

OBJECTIVE: Bladder rupture caused by transurethral clot evacuation is rare in clinic, but an emergency operation is indeed needed in the patient with bladder rupture. We analyzed the reasons of bladder rupture caused by transurethral clot evacuation and provided the countermeasures to guide clinical surgeon to prevent the iatrogenic damage of bladder. METHOD: We retrospectively reviewed the records of 287 patients in our hospital, who had bladder tamponade resulting from clots of blood for various reasons and underwent transurethral clot evacuation from January 2007 to January 2019. Six male cases, aged from 28 to 76 years (mean 56.67±17.76) had bladder rupture. Four patients whose bladder ruptured intraperitoneally were changed to open surgery to repair bladder and clear the remanent blood clots. Two patients with extraperitoneal bladder rupture and a small bladder crevasse underwent a conservative therapy. RESULTS: We observed that the incidence rate of bladder rupture was not associated with bladder tamponade and the age, but may be associated with gender, bladder paracentesis preoperative and urinary retention preoperative. All six cases were male.. They had different period of urinary retention before operation. No supra-pubis bladder paracentesis was made before operation. The bladder crevasses located in the triangle zone and posterior wall of bladder entirely, and the length of the bladder crevasses ranged from 3 to 7cm (mean 4.83cm). The bladder crevasses were all lengthways, and four cases were of' bladders ruptured intraperitoneally while another two presented an extraperitoneal bladder rupture. CONCLUSIONS: The reasons of bladder rupture caused by transurethral clot evacuation may be related to gender, bladder paracentesis preoperative and urinary retention preoperative. We should decide to use expectant treatment or open surgery immediately according to the extent of the rupture when bladder rupture occurs.

Validation and modification of the AJCC 8th TNM staging system for pancreatic ductal adenocarcinoma in a Chinese cohort: A nationwide pancreas data center analysis.

OBJECTIVE: To validate the 8th edition of the American Joint Committee on Cancer (AJCC) staging system for pancreatic ductal adenocarcinoma (PDAC) in a Chinese cohort of radically resected patients and to develop a refined staging system for PDAC. METHODS: Data were collected from the China Pancreas Data Center (CPDC) for patients with resected PDAC in 2016 and 2017, and cancer-specific survival (CSS) was evaluated using the Kaplan-Meier method and log-rank test. Univariate and multivariate analyses based on Cox regression were performed to identify prognostic factors. The recursive partitioning analysis (RPA), Kaplan-Meier method, and log-rank test were performed on the training dataset to generate a proposed modification for the 8th TNM staging system utilizing the preoperative carbohydrate antigen (CA)19-9 level. Validation was performed for both staging systems in the validation cohort. RESULTS: A total of 1,676 PDAC patients were retrieved, and the median CSS was significantly different between the 8th TNM groupings, with no significant difference in survival between stage IB and IIA. The analysis of T and N stages demonstrated a better prognostic value in the N category. Multivariate analysis showed that the preoperative serum CA19-9 level was the strongest prognostic indicator among all the independent risk factors. All patients with CA19-9 >500 U/mL had similar survival, and we proposed a new staging system by combining IB and IIA and stratifying all patients with high CA19-9 into stage III. The modified staging system had a better performance for predicting CSS than the 8th AJCC staging scheme. CONCLUSIONS: The 8th AJCC staging system for PDAC is suitable for a Chinese cohort of resected patients, and the N category has a better prognostic value than the T category. Our modified staging system has superior accuracy in predicting survival than the 8th AJCC TNM staging system.

Molecular mechanism of CaCCinh-A01 inhibiting TMEM16A channel.

TMEM16A is a calcium-activated chloride channel that is associate with several diseases, including pulmonary diseases, hypertension, diarrhea and cancer. The CaCCinh-A01 (A01) is widely recognized as an efficient blocker of TMEM16A and has been used as a tool drug to inhibit TMEM16A currents in the laboratory. A01 also has excellent pharmacokinetic properties and can be developed as a drug to target TMEM16A. However, the molecular mechanism how A01 inhibits TMEM16A is still elusive, which slows down its drug development process. Here, calculations identified that the binding pocket of A01 was located above the pore, and it was also discovered that the binding of A01 to TMEM16A not only blocked the pore but also led to its collapse. The interaction model analysis predicted that R515/K603/E623 were crucial residues for the binding between TMEM16A and A01, and the site-directed mutagenesis studies confirmed the above results. The binding mode and quantum chemical calculations showed that the carboxyl and the amide oxygen atom of A01 were the key interaction sites between TMEM16A and A01. Therefore, our study proposed the inhibitory mechanism of TMEM16A current by A01 and revealed how A01 inhibits TMEM16A at the molecular level. These findings will shed light on both the development of A01 as a potential drug for TMEM16A dysfunction-related disorders and drug screening targeting the pocket.

Allosteric mechanisms underlie GPCR signaling to SH3-domain proteins through arrestin.

Signals from 800 G-protein-coupled receptors (GPCRs) to many SH3 domain-containing proteins (SH3-CPs) regulate important physiological functions. These GPCRs may share a common pathway by signaling to SH3-CPs via agonist-dependent arrestin recruitment rather than through direct interactions. In the present study, 19F-NMR and cellular studies revealed that downstream of GPCR activation engagement of the receptor-phospho-tail with arrestin allosterically regulates the specific conformational states and functional outcomes of remote ß-arrestin 1 proline regions (PRs). The observed NMR chemical shifts of arrestin PRs were consistent with the intrinsic efficacy and specificity of SH3 domain recruitment, which was controlled by defined propagation pathways. Moreover, in vitro reconstitution experiments and biophysical results showed that the receptor-arrestin complex promoted SRC kinase activity through an allosteric mechanism. Thus, allosteric regulation of the conformational states of ß-arrestin 1 PRs by GPCRs and the allosteric activation of downstream effectors by arrestin are two important mechanisms underlying GPCR-to-SH3-CP signaling.