Structural basis of antagonist selectivity in endothelin receptors.

Endothelins and their receptors, ETA and ETB, play vital roles in maintaining vascular homeostasis. Therapeutically targeting endothelin receptors, particularly through ETA antagonists, has shown efficacy in treating pulmonary arterial hypertension (PAH) and other cardiovascular- and renal-related diseases. Here we present cryo-electron microscopy structures of ETA in complex with two PAH drugs, macitentan and ambrisentan, along with zibotentan, a selective ETA antagonist, respectively. Notably, a specialized anti-ETA antibody facilitated the structural elucidation. These structures, together with the active-state structures of ET-1-bound ETA and ETB, and the agonist BQ3020-bound ETB, in complex with Gq, unveil the molecular basis of agonist/antagonist binding modes in endothelin receptors. Key residues that confer antagonist selectivity to endothelin receptors were identified along with the activation mechanism of ETA. Furthermore, our results suggest that ECL2 in ETA can serve as an epitope for antibody-mediated receptor antagonism. Collectively, these insights establish a robust theoretical framework for the rational design of small-molecule drugs and antibodies with selective activity against endothelin receptors.

Pharmacokinetic study and neuropharmacological effects of atractylenolide â ¢ to improve cognitive impairment via PI3K/AKT/GSK3ß pathway in intracerebroventricular-streptozotocin rats.

ETHNOPHARMACOLOGICAL RELEVANCE: The traditional Chinese herbal remedy Atractylodes macrocephala Koidz is renowned for its purported gastrointestinal regulatory properties and immune-enhancing capabilities. Atractylenolide III (ATL III), a prominent bioactive compound in Atractylodes macrocephala Koidz, has demonstrated significant pharmacological activities. However, its impact on neuroinflammation, oxidative stress, and therapeutic potential concerning Alzheimer's disease (AD) remain inadequately investigated. AIM OF THE STUDY: This study aims to assess the plasma pharmacokinetics of ATL III in Sprague-Dawley (SD) rats and elucidate its neuropharmacological effects on AD via the PI3K/AKT/GSK3ß pathway. Through this research, we endeavor to furnish experimental substantiation for the advancement of novel therapeutics centered on ATL III. MATERIALS AND METHODS: The pharmacokinetic profile of ATL III in SD rat plasma was analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). AD models were induced in SD rats through bilateral intracerebroventricular (ICV) administration of streptozotocin (STZ). ATL III was administered at doses of 0.6 mg/kg, 1.2 mg/kg, and 2.4 mg/kg, while donepezil (1 mg/kg) served as control. Cognitive function assessments were conducted employing behavioral tests including the Morris Water Maze and Novel Object Recognition. Neuronal pathology and histological changes were evaluated through Nissl staining and Hematoxylin-Eosin (HE) staining, respectively. Oxidative stress levels were determined by quantifying malondialdehyde (MDA) content and total superoxide dismutase (T-SOD) activity. Molecular docking analysis was employed to explore the direct binding between ATL III and its relevant targets, followed by validation using Western blot (WB) experiments to assess the expression of p-Tau, PI3K, AKT, GSK3ß, and their phosphorylated forms. RESULTS: Within the concentration range of 5-500 ng/mL, ATL III demonstrated exceptional linearity (R2 = 0.9991), with a quantification limit of 5 ng/mL. In male SD rats, ATL III exhibited a Tmax of 45 min, a t1/2 of 172.1 min, a Cmax of 1211 ng/L, and an AUC(0-t) of 156031 ng/L*min. Treatment with ATL III significantly attenuated Tau hyperphosphorylation in intracerebroventricular-streptozotocin (ICV-STZ) rats. Furthermore, ATL III administration mitigated neuroinflammation and oxidative stress, as evidenced by reduced Nissl body loss, alleviated histological alterations, decreased MDA content, and enhanced T-SOD activity. Molecular docking analyses revealed strong binding affinity between ATL III and the target genes PI3K, AKT, and GSK3ß. Experimental validation corroborated that ATL III stimulated the phosphorylation of PI3K and AKT while reducing the phosphorylation of GSK3ß. CONCLUSIONS: Our results indicate that ATL III can mitigate Tau protein phosphorylation through modulation of the PI3K/AKT/GSK3ß pathway. This attenuation consequently ameliorates neuroinflammation and oxidative stress, leading to enhanced learning and memory abilities in ICV-STZ rats.

Bitter taste TAS2R14 activation by intracellular tastants and cholesterol.

Bitter taste receptors, particularly TAS2R14, play central roles in discerning a wide array of bitter substances, ranging from dietary components to pharmaceutical agents1,2. TAS2R14 is also widely expressed in extragustatory tissues, suggesting its extra roles in diverse physiological processes and potential therapeutic applications3. Here we present cryogenic electron microscopy structures of TAS2R14 in complex with aristolochic acid, flufenamic acid and compound 28.1, coupling with different G-protein subtypes. Uniquely, a cholesterol molecule is observed occupying what is typically an orthosteric site in class A G-protein-coupled receptors. The three potent agonists bind, individually, to the intracellular pockets, suggesting a distinct activation mechanism for this receptor. Comprehensive structural analysis, combined with mutagenesis and molecular dynamic simulation studies, elucidate the broad-spectrum ligand recognition and activation of the receptor by means of intricate multiple ligand-binding sites. Our study also uncovers the specific coupling modes of TAS2R14 with gustducin and Gi1 proteins. These findings should be instrumental in advancing knowledge of bitter taste perception and its broader implications in sensory biology and drug discovery.

Simultaneous Force and Fluorescence Spectroscopy on Single Chains of Polyfluorene: Effect of Intra-Chain Aggregate Coupling.

Conjugated polymer chains in compact conformations or in films exhibit spectral features that can be attributed to interactions between individual conjugated segments of the chain, including formation of aggregates or excimers. Here, we use atomic force microscopy (AFM) on single chains of the conjugated polymer polyfluorene (PFO) to control the intersegment interactions by mechanically unfolding the chain. Simultaneously with the force spectroscopy we monitor fluorescence from the single PFO chains using a fluorescence microscope. We found that mechanical stretching of the chain causes disappearance of the green emission band. This observation provides evidence that the green emission originates from an intrachain aggregated state on the self-folded chain, which is decoupled by the stretching. In addition, the stretching upon laser irradiation leads to the appearance of additional features in the force spectra, small force peaks in the initial stages of the unfolding. These features are attributed to a combination of excitonic and van der Waals coupling of a ground-state intrachain aggregate.

Efficacy and safety of acupuncture as a complementary therapy for sepsis: a systematic review and meta-analysis.

BACKGROUND: Sepsis is a life-threatening organ dysfunction caused by dysregulation of the host response to infection. Acupuncture is used for treatment of inflammatory diseases; however, its effectiveness and safety as a complementary therapy for sepsis has not been fully explored. METHODS: Data were retrieved from eight databases. Randomized controlled trials (RCTs) that compared acupuncture plus conventional therapies versus conventional therapies alone were included. Pre-specified primary outcomes were mortality at 28 days and Acute Physiologic and Chronic Health Evaluation (APACHE) II scores. RESULTS: A total of 17 studies with 1099 participants were included in this study. In terms of the primary outcomes, acupuncture plus routine therapy reduced mortality at 28 days (risk ratio (RR)): 0.69, 95% confidence interval (CI): 0.52 to 0.91, p < 0.001) and APACHE II scores (mean difference (MD): -2.84, 95% CI: -4.09 to -1.58, p < 0.001) at day 7 after treatment compared with routine therapy alone. In terms of secondary outcomes, acupuncture plus routine therapy reduced white blood cell counts and levels of procalcitonin (PCT), tumor necrosis factor (TNF)-α, interleukin (IL)-6 and lactic acid and intra-abdominal pressure (IAP), and improved CD3+, CD4+ and monocytes of human leukocyte antigen (HLA)-DR at day 7 after treatment compared with routine therapy alone. However, acupuncture plus routine therapy had no significant effects on levels of IL-10, C-reactive protein (CRP), CD8+ and CD4+/CD8+ ratios compared with routine therapy alone. Quality of evidence was low to very low for all parameters (GRADE). CONCLUSION: The available evidence showed that combination of acupuncture and routine therapy may have benefit for sepsis compared with use of routine therapy only. Due to the low degree of certainty regarding its effects, further research is required. TRIAL REGISTRATION NUMBER: ICRD42019141491 (PROSPERO).

Structural basis for strychnine activation of human bitter taste receptor TAS2R46.

Taste sensing is a sophisticated chemosensory process, and bitter taste perception is mediated by type 2 taste receptors (TAS2Rs), or class T G protein-coupled receptors. Understanding the detailed molecular mechanisms behind taste sensation is hindered by a lack of experimental receptor structures. Here, we report the cryo-electron microscopy structures of human TAS2R46 complexed with chimeric mini-G protein gustducin, in both strychnine-bound and apo forms. Several features of TAS2R46 are disclosed, including distinct receptor structures that compare with known GPCRs, a new "toggle switch," activation-related motifs, and precoupling with mini-G protein gustducin. Furthermore, the dynamic extracellular and more-static intracellular parts of TAS2R46 suggest possible diverse ligand-recognition and activation processes. This study provides a basis for further exploration of other bitter taste receptors and their therapeutic applications.

Acupuncture for emotional symptoms in patients with functional gastrointestinal disorders: A systematic review and meta-analysis.

BACKGROUND: Patients with functional gastrointestinal disorders (FGIDs) also often have emotional symptoms, such as anxiety and depression. The main drugs used for the treatment of FGIDs mainly target single gastrointestinal symptoms and are not effective in regulating emotional symptoms. Evidence has shown that acupuncture can relieve gastrointestinal symptoms in FGIDs patients, but there is no high-quality evidence to show that acupuncture can relieve psychological symptoms in these patients. OBJECTIVES: To systematically evaluate the clinical efficacy and safety of acupuncture for emotional symptoms in patients with FGIDs. METHODS: Randomized controlled trials (RCTs) published from database inception through July 31, 2021, were retrieved from three English-language databases (PubMed, the Cochrane Central Register of Controlled Trials, and Embase) and five Chinese-language databases (the China National Knowledge Infrastructure, Wanfang, VIP, Chinese Biomedical, and TCM Literature Analysis and Retrieval databases). RCTs that compared acupuncture with sham acupuncture and pharmacotherapy were included in this study. The score on the depression or anxiety scale after treatment were considered as primary outcomes. The 'meta' package (version 4.19-0) in RStudio 1.1.463 was used to analyse the data. RESULTS: A total of 2151 patients from 24 RCTs were included in this study. Compared with sham acupuncture, acupuncture was not significantly better at relieving anxiety (standardized mean difference [SMD] -0.35, 95% CI -1.05 to 0.33) and depression (SMD -0.32, 95% CI -0.71 to 0.07) symptoms. Compared with pharmacotherapy, acupuncture was significantly better at relieving anxiety (SMD -0.64, 95% CI -0.93 to -0.35) and depression (SMD -0.46, 95% CI -0.69 to -0.22) symptoms. CONCLUSIONS: This meta-analysis found that acupuncture can alleviate emotional symptoms in FGID patients better than pharmacotherapy. However, it is not clear whether this effect is based on the placebo effect, specific effect or nonspecific effect of acupuncture. The evidence should be proven by rigorously designed RCTs in the future. PROSPERO REGISTRATION NUMBER: CRD42021271899.

[Effect of umbilical moxibustion on phlegm damp constitution and intestinal flora].

OBJECTIVE: To observe the effect of umbilical moxibustion on phlegm damp constitution and intestinal flora, and explore the mechanism of umbilical moxibustion in improving phlegm damp constitution. METHODS: A total of 60 subjects with phlegm damp constitution were randomly divided into an observation group and a control group, 30 cases in each group. The control group was given TCM health guidance, such as diet and exercise; on the basis of the control group, umbilical moxibustion was applied in the observation group, 7 moxa cones each time, 2 times a week for 8 weeks. Before and after intervention, the indexes (transformation score of phlegm damp constitution, body mass, body mass index [BMI], waist circumference, hip circumference, heart rate and blood pressure) related to phlegm damp constitution were recorded in the two groups. The intestinal flora was detected with 16S rDNA sequencing technology in the two groups. RESULTS: After intervention, the transformation score of phlegm damp constitution, body mass, BMI, waist circumference and hip circumference were decreased compared before intervention in the observation group (P<0.001, P<0.01, P<0.05), the transformation score of phlegm damp constitution and waist circumference were decreased compared before intervention in the control group (P<0.001, P<0.05); the transformation score of phlegm damp constitution and waist circumference in the observation group were lower than the control group (P<0.001, P<0.05). After intervention, the relative abundance of Eubacterium hallii in the observation group was increased (P<0.01), the relative abundance of Blautia in the control group was decreased (P<0.05). CONCLUSION: Umbilical moxibustion may reshape the intestinal flora by up-regulating the relative abundance of Eubacterium hallii, thus improving phlegm damp constitution.

Efficacy of acupuncture for melasma: A protocol of systematic review and meta-analysis.

BACKGROUND: Melasma is a common acquired hyperpigmentation of the skin. The clinical manifestations are light brown or dark brown patches symmetrically distributed on the cheeks, forehead, and mandibular with different shades and unclear borders. The treatment of melasma is extremely challenging due to its easy relapse and hard to cure. As a classical method of traditional Chinese medicine, acupuncture has been used to treat melasma in clinical practice. However, there is no systematic review and meta-analysis of acupuncture on melasma. This study aims to assess the efficacy of acupuncture for melasma. METHODS: We will perform a comprehensive retrieval in the following electronic databases: PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure (CNKI), Wan Fang Database, VIP database, Chinese Biomedical Literature Service System (SinoMed), Chinese Biomedicine (CBM) database, and TCM Literature Analysis from inception to July 1, 2021, to identify any eligible study. We include all randomized controlled trials (RCTs) without any limitation of blinding or publication language, and exclude cohort studies and case reports. The meta-analyses will be conducted by using the Stata16. We will use the Cochrane risk of bias tool for randomized trials to assess the risk of bias of included studies. The X2 and I2 tests will be utilized to assess the statistical heterogeneity of evidence. We will conduct a meta-analysis if the studies can be combined. Otherwise, a narrative synthesis will be performed. Article screening and data extraction will be independently evaluated by 2 reviewers trained in methodology according to the established selection criteria. Any disagreements between the 2 reviewers will be resolved by reaching a consensus with the other authors (the third reviewer). RESULTS: This study will systematically evaluate the clinical efficacy of acupuncture for melasma. CONCLUSION: The conclusion of this study will provide evidence to ensure the efficacy of acupuncture for melasma, so as to provide an objective and scientific basis for clinical practice. ETHICS AND DISSEMINATION: No ethical approval will be required because the data used are not linked to individual patient. The results of this review will be published in a peer-reviewed journal. REGISTRATION NUMBER: INPLASY2021110097.

Acupuncture for headache in COVID-19: A protocol for systematic review and meta-analysis.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is an acute respiratory infectious disease which making people difficult to breathe and often accompanied with headache. Acupuncture have been proved the therapeutic effect on headache, but there has been no high-quality evidence on acupuncture for the headache in COVID-19. This study is designed to evaluate the effectiveness and safety of acupuncture for headache in COVID-19. METHODS: Randomized controlled trials from December 2019 to July 2021 will be included without restrictions on language or publication date. PubMed, EMBASE, Cochrane Library, Web of Science, Chinese Biomedical Databases, China National Knowledge Infrastructure, Wanfang database, and VIP database will be searched. Two researchers will independently select studies, extract data and evaluate study quality. Cochrane risk of bias tool for randomized trials will be used to assess the risk of bias of included studies. Statistical analyses will be performed using the Review Manager V.5.3 and stata 14.0. ETHICS AND DISSEMINATION: This study will not involve personal information. Ethical approval will not be required. We will publish the results in a peer-reviewed journal. PROSPERO TRIAL REGISTRATION NUMBER: CRD42021270722.

Enhancement of the Photocurrent of a Single Photosystem I Complex by the Localized Plasmon of a Gold Nanorod.

A combination of conductive atomic force microscopy (AFM) and confocal fluorescence microscopy was used to measure photocurrents passing through single trimeric photosytem I (PSI) complexes located in the vicinity of single gold nanorods (AuNRs). Simultaneous excitation of PSI and of the AuNR longitudinal plasmon mode and detection of photocurrents from individual PSI in relation to the position of single AuNRs enable insight into plasmon-induced phenomena that are otherwise inaccessible in ensemble experiments. We have observed photocurrent enhancement by the localized plasmons by a factor of 2.9 on average, with maximum enhancement values of up to 8. Selective excitation of the longitudinal plasmon modes by the polarization of the excitation laser enables controllable switch-on of the photocurrent enhancement. The dependence of the extent of enhancement on the distance between PSI and AuNRs indicates that, apart from the enhancement of absorption, there is an additional enhancement mechanism affecting directly the electron transport process. The present study provides deeper insight into the molecular mechanisms of plasmon-enhanced photocurrents, not only in PSI but also potentially in other systems as well.

Acupuncture for Subthreshold Depression: Study Protocol for a Randomized Controlled Trial.

BACKGROUND: Subthreshold depression refers to a state of mental sub-health that has depressive symptoms but does not meet the diagnostic criteria for major depressive disorder. It is a strong risk factor for depression and is related to an increase in suicide and mortality. Studies suggest that acupuncture may be effective in the treatment of subthreshold depression, but no evidence has proven that the efficacy of acupuncture for subthreshold depression is a specific therapeutic effect or a placebo effect. METHODS: This will be a prospective, randomized, controlled, and double-blind study of 64 patients with subthreshold depression. They will be randomly assigned as verum or minimal acupuncture group members. Patients in the verum acupuncture group will receive acupuncture at the acupoints, and those in the minimal acupuncture group will receive minimal acupuncture at non-acupoints. The interventions will be delivered over an 8-week period. The primary outcome measure will be the Hamilton Depression Scale-17 (HAMD-17). The secondary outcome measures will be the 9-item Patient Health Questionnaire (PHQ-9), 7-item Generalized Anxiety Disorder (GAD-7), and SF-12v2 Health Survey. The assessments will occur at baseline, 4 weeks, 8 weeks, and during a follow-up period. DISCUSSION: The protocol uses a randomized controlled trial to examine the effectiveness of acupuncture for subthreshold depression and to further study the mechanisms of its effect.

Jiaji (EX-B2)-Based Electroacupuncture Preconditioning Attenuates Early Ischaemia Reperfusion Injury in the Rat Myocardium.

BACKGROUND: Acupuncture preconditioning was able to reduce the extent of ischaemia reperfusion (I/R) injury. Previous studies have shown that electroacupuncture (EA) pretreatment at T4-T5 Jiaji (EX-B2) acupoints had cardioprotective effects against myocardial I/R injury. However, the molecular mechanism remains inconclusive. METHODS: Wistar rats were pretreated with electroacupuncture for 7 days at the Neiguan (PC6), T4-T5 Jiaji (EX-B2), Yanglingquan (GB34), and Quchi (LI11) acupoints, which belong to different meridians. Then, we investigated the genome-wide gene expression profiles of rats prestimulated at these acupoints after I/R injury. RESULTS: Our study revealed previously unknown cardioprotective roles of T4-T5 Jiaji (EX-B2) acupoints in the I/R progression. The extent of myocardial injury was significantly decreased in the Jiaji group compared with the I/R group. In addition, our data are among the first to link the EA preconditioning at Neiguan (PC6) acupoints and circadian rhythm in the I/R model. Also, for the first time, we explored the meridian and acupoint specificity involved in EA pretreatment at the heart meridian, in which Yanglingquan and Quchi acupoints were selected as the control group for heart-divergent-meridian and nonheart-meridian acupoints. CONCLUSIONS: The present study suggested that EA pretreatment at Jiaji alters genome-wide gene expression and protects the rat myocardium against I/R injury, which are most likely through neurohumoral regulation.

Effects of acupuncture for nonalcoholic fatty liver disease: A protocol for systematic review and meta-analysis.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is a multisystem disease, which may develop gradually into nonalcoholic steatohepatitis, liver fibrosis, and cirrhosis. As a classical method of traditional Chinese medicine, acupuncture has been used to treat NAFLD in clinical practice. However, there is no systematic review and meta-analysis of acupuncture on NAFLD. There is an urgent need to evaluate the clinical efficacy of acupuncture for NAFLD. METHODS: We will perform a comprehensive retrieval in the following electronic databases: MEDLINE, Embase, Cochrane Library Central Register of Controlled Trials, PubMed, Science Citation Index Expanded (Web of Science), Epistemonikos, China National Knowledge Infrastructure (CNKI) database, Wanfang Data Knowledge Service Platform, Chinese Scientific Journals Database (VIP), Chinese Biomedical Literature Service System (SinoMed), and other databases from their inception to October 2020. We will select the qualified studies for data extraction and assess the quality and risk of bias, independently. The meta-analyses will be conducted by using the RevMan 5.3. RESULTS: This study will provide a reliable basis for the treatment of NAFLD with acupuncture. CONCLUSION: The findings will be an available reference to evaluate whether acupuncture is an effective intervention for patient with NAFLD. OSF REGISTRATION NUMBER: 10.17605/OSF.IO/VFYXH.

Enhanced Contextual Fear Memory and Elevated Astroglial Glutamate Synthase Activity in Hippocampal CA1 BChE shRNA Knockdown Mice.

Butyrylcholinesterase (BChE) efficiently hydrolyzes acetylcholine (ACh) at high concentrations when acetylcholinesterase (AChE) is substrate-inhibited. Recent studies have shown that BChE also has a function that is independent of ACh, but it has not been fully explored. Low BChE expression is accompanied with higher stress-induced aggression and ghrelin levels in stress models, and BChE knockout mice exhibit cognitive and memory impairments. However, the role of BChE in posttraumatic stress disorder (PTSD) remains unclear. In the present study, we investigated the role of BChE in contextual fear memory and its regulatory effect on the expression of factors related to the glutamate (Glu)-glutamine (Gln) cycle via knockdown studies. We used AAVs and lentiviruses to knockdown BChE expression in the mouse hippocampal CA1 region and C8D1A astrocytes. Our behavioral data from those mice injected with AAV-shBChE in the hippocampal CA1 region showed strengthened fear memory and increased dendritic spine density. Elevated Glu levels and glutamine synthetase (GS) enzyme activity were detected in contextual fear conditioned-BChE knockdown animals and astrocytes. We observed that an AAV-shBChE induced lowering of BChE expression in the hippocampus CA1 region enhanced contextual fear memory expression and promoted the astrocytic Glu-Gln cycle but did not elevate ACh-hydrolyzing activity. This study provides new insight into the regulatory role of BChE in cognition and suggests potential target for stress-related psychiatric disorder such as PTSD where patients experience fear after exposure to severe life-threatening traumatic events.

Arrays of Plasmonic Nanostructures for Absorption Enhancement in Perovskite Thin Films.

We report optical characterization and theoretical simulation of plasmon enhanced methylammonium lead iodide (MAPbI 3 ) thin-film perovskite solar cells. Specifically, various nanohole (NH) and nanodisk (ND) arrays are fabricated on gold/MAPbI 3 interfaces. Significant absorption enhancement is observed experimentally in 75 nm and 110 nm-thick perovskite films. As a result of increased light scattering by plasmonic concentrators, the original Fabry-Pérot thin-film cavity effects are suppressed in specific structures. However, thanks to field enhancement caused by plasmonic resonances and in-plane interference of propagating surface plasmon polaritons, the calculated overall power conversion efficiency (PCE) of the solar cell is expected to increase by up to 45.5%, compared to its flat counterpart. The role of different geometry parameters of the nanostructure arrays is further investigated using three dimensional (3D) finite-difference time-domain (FDTD) simulations, which makes it possible to identify the physical origin of the absorption enhancement as a function of wavelength and design parameters. These findings demonstrate the potential of plasmonic nanostructures in further enhancing the performance of photovoltaic devices based on thin-film perovskites.

Efficacy and safety of acupuncture as a complementary therapy for sepsis: A protocol of systematic review and meta-analysis.

INTRODUCTION: Sepsis is a physiological, pathological, and biochemical syndrome caused by infection. Acupuncture may be useful for sepsis. This systematic review aims to assess the efficacy and safety of acupuncture as a complementary therapy for sepsis. METHODS AND ANALYSIS: We will search PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure (CNKI), Wan Fang Database, Chinese Biomedicine (CBM) database, VIP database, and TCM Literature Analysis and Retrieval Database from inception to October 31, 2019 to identify any eligible study. We include all randomized controlled trials (RCTs) without any limitation of blinding or publication language, exclude cohort studies and case reports. Two reviewers will independently select studies, extract and manage data. The primary outcomes include the mortality at 28 days, acute physiology, and chronic health evaluation II scores. The secondary outcomes include the tumor necrosis factor α (TNF-α) counts, interleukin 6 (IL-6) counts, interleukin 10 (IL-10) counts, procalcitonin (PCT), lactic acid, the level of T cell subsets (CD3+, CD4+, CD8+, CD4+/CD8+), monocytes of human leukocyte antigen DR (HLA-DR), C-reactive protein (CRP), the numeration of leukocyte, intra-abdominal pressure, and adverse events or reactions. Statistical analyses will be performed using the Review Manager V.5.3 and R packages Metafor. We will use the Cochrane risk of bias tool for randomized trials to assess the risk of bias of included studies. ETHICS AND DISSEMINATION: This study will not involve personal information. Ethical approval will not be required. We will publish the results in a peer-reviewed journal. PROSPERO TRIAL REGISTRATION NUMBER: CRD42019141491.

Colocalization Strategy Unveils an Underside Binding Site in the Transmembrane Domain of Smoothened Receptor.

We unveiled an underside binding site on smoothened receptor (SMO) by a colocalization strategy using two structurally complementary photoaffinity probes derived from a known ligand Allo-1. Docking study and structural dissection identified key interactions within the site, including hydrogen bonding, π-π interactions, and hydrophobic interactions between Allo-1 and its contacting residues. Taken together, our results reveal the molecular base of Allo-1 binding and provide a basis for the design of new-generation ligands to overcome drug resistance.

Disulfide-Containing Detergents (DCDs) for the Structural Biology of Membrane Proteins.

Disulfide-containing detergents (DCDs) are introduced, which contain a disulfide bond in the hydrophobic tail. DCDs form smaller micelles than corresponding detergents with linear hydrocarbon chains, while providing good solubilization and reconstitution of membrane proteins. The use of this new class of detergents in structural biology is illustrated with solution NMR spectra of the human G protein-coupled receptor A2A AR, which is an α-helical protein, and the ß-barrel protein OmpX from E. coli.