Structural basis of CXC chemokine receptor 2 activation and signalling.

Chemokines and their receptors mediate cell migration, which influences multiple fundamental biological processes and disease conditions such as inflammation and cancer1. Although ample effort has been invested into the structural investigation of the chemokine receptors and receptor-chemokine recognition2-4, less is known about endogenous chemokine-induced receptor activation and G-protein coupling. Here we present the cryo-electron microscopy structures of interleukin-8 (IL-8, also known as CXCL8)-activated human CXC chemokine receptor 2 (CXCR2) in complex with Gi protein, along with a crystal structure of CXCR2 bound to a designed allosteric antagonist. Our results reveal a unique shallow mode of binding between CXCL8 and CXCR2, and also show the interactions between CXCR2 and Gi protein. Further structural analysis of the inactive and active states of CXCR2 reveals a distinct activation process and the competitive small-molecule antagonism of chemokine receptors. In addition, our results provide insights into how a G-protein-coupled receptor is activated by an endogenous protein molecule, which will assist in the rational development of therapeutics that target the chemokine system for better pharmacological profiles.

Effect of different nutrients on blood glucose, inflammatory response and oxidative stress in gestational diabetes mellitus: a network meta-analysis.

We searched PubMed, Web of Science, Embase, The Cochrane Library, China Biomedical Literature Database and other databases from inception to June 2023. The included studies were randomised controlled trials (RCT). The studies were screened by four authors, divided into two independent pairs. A total of eighteen studies were included, including 1362 patients, involving twelve intervention measures. The different nutrients had a significant effect on improving blood glucose, reducing inflammation levels and reducing oxidative stress compared with placebo (P < 0.05). Cumulative probability ranking showed that vitamin A + vitamin D + vitamin E ranked first in lowering fasting blood glucose (standardised mean difference (SMD) = 41.30, 95 % CI (2.07, 825.60)) and postprandial 2-h blood glucose (SMD = 15.19, 95 % CI (4.16, 55.53)). In terms of insulin resistance index, the first highest probability ranking is vitamin D (SMD = 5.12, 95 % CI (0.76, 34.54)). In terms of reducing the high-sensitivity C-reactive protein level, the first in probability ranking is VE (SMD = 2.58, 95 % CI (1.87,3.55)). The results of cumulative probability ranking showed that Mg + Zn + Ca + VD ranked first in reducing TNF-α (SMD = 1.90, 95% CI (0.40, 9.08)) and IL-6 (SMD = 1.83, 95 % CI (0.37, 9.12)). In terms of reducing malondialdehyde levels, the first ranked probability is VB1 (SMD = 4.99, 95 % CI (1.85, 13.46)). Cumulative probability ranking results showed that Ca + VD ranked first in reducing total antioxidant capacity (SMD = 0.66,95 % CI (0.38, 1.15)) and glutathione (SMD = 1.39, 95 % CI (0.43, 4.56)). In conclusion, nutritional interventions have significant effects on improving blood glucose, inflammatory levels and oxidative stress in patients with gestational diabetes. Due to the high uncertainty in the results and differences in the number and quality of studies included, the reliability of the conclusions still needs to be validated by conducting large-sample, high-quality RCT studies.

Optimal peritoneal cancer index cutoff point for predicting surgical resectability of pseudomyxoma peritonei in treatment-naive patients.

BACKGROUND: The peritoneal cancer index (PCI) has been used to predict surgical outcomes for pseudomyxoma peritonei (PMP). The present study aimed to establish the optimal cutoff point for PCI to predict surgical resectability of PMP. METHODS: A total of 366 PMP patients were included. The patients were divided into low-grade and high-grade groups. Based on the completeness of the cytoreduction (CC) score, both low-grade and high-grade PMP patients were further divided into complete cytoreductive surgery (CRS) and maximal tumor debulking (MTD) subgroups. The ability to predict surgical resectability of total and selected PCI (regions 2 + 9 to 12) was analyzed through receiver operating characteristic (ROC) curves. RESULTS: Both total and selected PCI demonstrated excellent discriminative ability in predicting surgical resectability for low-grade PMP patients (n = 266), with the ROC-AUC of 0.940 (95% CI: 0.904-0.965) and 0.927 (95% CI: 0.889-0.955). The corresponding optimal cutoff point was 21 and 5, respectively. For high-grade PMP patients (n = 100), both total and selected PCI exhibited good performance in predicting surgical resectability, with the ROC-AUC of 0.894 (95% CI: 0.816-0.946) and 0.888 (95% CI: 0.810-0.943); correspondingly, the optimal cutoff point was 25 and 8, respectively. The discriminative ability between total and selected PCI in predicting surgical resectability did not show a statistical difference. CONCLUSIONS: Both total and selected PCI exhibited good performance and similarity in predicting complete surgical resection for both low-grade and high-grade PMP patients. However, the selected PCI was simpler and time-saving in clinical practice. In the future, new imaging techniques or predictive models may be developed to better predict PCI preoperatively, which might assist in confirming whether complete surgical resection can be achieved.

Factors affecting clinical pregnancy in controlled ovarian hyperstimulation with GnRH-a long protocol: a retrospective cross-sectional study.

This retrospective cross-sectional study was to investigate factors affecting clinical pregnancy in patients who received gonadotropin-releasing hormone agonist luteal phase long protocol (GnRH-a long protocol) and underwent fresh in-vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) embryo transfer cycle. One thousand five hundred and twenty-five patients who received GnRH-a long protocol and underwent fresh IVF/ICSI embryo transfer cycle were enrolled. The clinical pregnancy rate (63.1 vs. 22.4%, p < .05) and live birth rate (53.8 vs. 14.5%, p < .05) were significantly higher while the miscarriage rate (12.5 vs. 35.3%, p < .05) was significantly lower in the two embryo group than those in the one embryo group. The clinical pregnancy rate (48.5 vs. 64.1%, p < .05) and live birth rate (38.4 vs. 55.0%, p < .05) were significantly lower in patients older than 33.5 years than those in younger patients. The clinical pregnancy rate (52 and 60.6 vs. 79.7%, p < .05) and live birth rate (36 and 51.4 vs. 69.6%, p < .05) of the thin and mediate groups were significantly lower than those in the thick group, whereas the ectopic pregnancy rate (11.5 and 1.9 vs. 0%, p < .05) was significantly higher in the thin group than in the mediate and thick group. Multivariate logistic regression analysis showed that age (OR = 0.956, 95% CI [0.931, 0.982], p < .05), number of embryos transferred (OR = 2.491, 95% CI [1.670, 3.715], p < .05) and endometrial thickness on the transplantation day (OR = 1.124, 95% CI [1.067, 1.185], p < .05) were independent factors significantly associated with clinical pregnancy. In conclusion, endometrial thickness (>14.69 mm) on the day of transfer, two cleavage embryos transferred, and female age (≤33.5 years) are independent factors affecting clinical pregnancy outcomes in controlled ovarian hyperstimulation with GnRH-a long protocol for assisted conception. IMPACT STATEMENTWhat is already known on this subject? Fresh embryo transfer cycle with GnRH-a long protocol will result in a higher pregnancy rate in controlled ovarian hyperstimulation cycles.What do the results of this study add? Endometrial thickness on the day of transfer, number of embryos transferred, and female age were independent factors affecting clinical pregnancy outcomes.What are the implications of these findings for clinical practice and/or further research? When performing a fresh IVF/ICSI embryo transfer cycle with GnRH-a long protocol for ovulation induction, the independent affecting factors should be taken into consideration.

Jejunogastric intussusception after Whipple procedure with B-II reconstruction: a case report.

BACKGROUND: Jejunogastric intussusception (JGI) is a rare but severe complication after gastric surgery. JGI can occur from a few days to 55 years postoperatively and has a reported incidence of < 0.1% in patients who undergo gastric surgery. We firstly report a male patient with duodenal cancer who underwent Whipple's procedure with side-to-side gastrojejunostomy and who subsequently developed JGI. A literature review is provided. CASE PRESENTATION: A 68-year-old man was admitted to our emergency department with left upper quadrant abdominal pain and hematemesis of 4 h' duration. He had undergone Whipple's procedure (duct-to-mucosa pancreaticojejunostomy and side-to-side gastrojejunostomy) with B-II reconstruction for duodenal papillary adenocarcinoma 5 years earlier. His vital signs were stable with a blood pressure of 163/93 mmHg, temperature of 37.0 °C; and heart and respiratory rates of 86 per/min and 20 per/min, respectively. Physical assessment showed mild tenderness in the left upper quadrant, only. A complete blood count showed white cell and platelet counts of 11.69 × 103/L and 196 × 103/L, respectively, and a hemoglobin level of 13.5 g/L. Abdominal computed tomography (CT) suggested a retrograde intussusception of the intestines into the stomach with dilatation of the remnant stomach. The patient immediately underwent exploratory laparotomy, which revealed a 20-cm retrograde efferent limb at the remnant stomach that had travelled through the previous gastrojejunostomy. There was no evidence of malignancy. We manually reduced the intussuscepted loop using gentle traction, and the viability of the intestinal loop was preserved. The patient had an uneventful postoperative recovery. CONCLUSION: JGI is a rare but potentially fatal complication after gastric surgery, especially following Whipple's procedure. Early diagnosis and treatment are crucial, and surgery is considered the most effective treatment for JGI.

Comparison of surgical outcomes between isolated pancreaticojejunostomy, isolated gastrojejunostomy, and conventional pancreaticojejunostomy after pancreaticoduodenectomy: a systematic review and meta-analysis.

BACKGROUND: We aimed to compare the safety and effectiveness of the following procedures after pancreaticoduodenectomy: isolated pancreaticojejunostomy, isolated gastrojejunostomy, and conventional pancreaticojejunostomy. METHODS: We performed a systematic search of the following databases: PubMed, Embase, Web of Science, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov until 1 January 2020. Pooled odds ratios (OR) or weighted mean differences (WMD) with 95% confidence intervals (CIs) were calculated using STATA 12.0 statistical software. RESULTS: Thirteen studies involving 1942 patients were included in this study. Pooled analysis showed that reoperation rates following isolated pancreaticojejunostomy were lower reoperation than with conventional pancreaticojejunostomy (OR = 0.36, 95% CI: 0.15-0.86, p = 0.02, respectively), and that isolated pancreaticojejunostomy required longer operation time vs conventional pancreaticojejunostomy (WMD = 43.61, 95% CI: 21.64-65.58, P = 0.00). Regarding postoperative pancreatic fistula, clinically-relevant postoperative pancreatic fistula, delayed gastric emptying, clinically-relevant delayed gastric emptying, bile leakage, hemorrhage, reoperation, length of postoperative hospital stay, major complications, overall complications, and mortality, we found no significant differences for either isolated pancreaticojejunostomy versus conventional pancreaticojejunostomy or isolated gastrojejunostomy versus conventional pancreaticojejunostomy. CONCLUSIONS: This study showed that isolated pancreaticojejunostomy was associated with a lower reoperation rate, but required longer operation time vs conventional pancreaticojejunostomy. Considering the limitations, high-quality randomized controlled trials are required.

A piggyBac-based TANGO GFP assay for high throughput screening of GPCR ligands in live cells.

BACKGROUND: GPCRs are considered essential for various physiological processes and have been the most productive drug targets. Therefore, development of the methods of GPCR ligands screening is a high priority for pharmaceutical industries and research institutions. METHODS: We developed a potential method (piggyBac-TANGO) based on the TANGO and PRESTO-TANGO assays. The system was optimized with a piggyBac transposon as a transgene vehicle, and eGFP was used as a reporter instead of luciferase. The assay was validated in the HEK 293T and U87-MG cell lines and antagonist activities of the compounds were assessed. The transgene copy number and long-term stability were evaluated by qPCR. Then, we performed a DRD2-targeted screening for natural products using the piggyBac-TANGO assay. RESULTS: The validation assay showed that using the piggyBac transposon as a transgene vehicle produced high signal-to-background ratio and stable readout confirmed by investigation of the transgene copy number and long-term stability. Use of eGFP instead of luciferase as a reporter enabled to create a high throughput system suitable for live cells. Moreover, the piggyBac-TANGO assay permitted versatile detection of antagonist activity of compounds and was not limited to a particular cell type. With the use of the piggyBac-TANGO assay, we have successfully identified a novel agonist of DRD2. CONCLUSION: Thus, the results indicate that the piggyBac-TANGO method is a user-friendly, robust and imaging-based assay that provides a novel approach to high throughput GPCR-targeted ligand screening and drug development.

The structure-based traceless specific fluorescence labeling of the smoothened receptor.

The smoothened receptor (SMO) mediates the hedgehog (Hh) signaling pathway and plays a vital role in embryonic development and tumorigenesis. The visualization of SMO has the potential to provide new insights into its enigmatic mechanisms and associated disease pathogenesis. Based on recent progress in structural studies of SMO, we have designed and characterized a group of affinity probes to facilitate the turn-on fluorescence labeling of SMO at the ε-amine of K395. These chemical probes were derived from a potent SMO antagonist skeleton by the conjugation of a small non-fluorescent unit, O-nitrobenzoxadiazole (O-NBD). In this context, optimal probes were developed to be capable of efficiently and selectively lighting up SMO regardless of whether it is in micelles or in native membranes. More importantly, the resulting labeled SMO only bears a very small fluorophore and allows for the recovery of the unoccupied pocket by dissociation of the residual ligand module. These advantages should allow the probe to serve as a potential tool for monitoring SMO trafficking, understanding Hh activation mechanisms, and even the diagnosis of tumorigenesis in the future.

A first report of porphyria cutanea tarda successfully treated with glycyrrhizin.

Porphyria cutanea tarda (PCT) is a condition that affects liver and skin by reduction of hepatic uroporphyrinogen decarboxylase activity. It is characterized by blistering lesions, erosions and crusts on sun-exposed areas. We report a 51-year-old male presenting with recurrent episodes of bullae, erosions, and crust on his neck and dorsum of the hands for 3 months. Aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transferase, alkaline phosphatase, lactate dehydrogenase levels, as well as total plasma porphyrin and urinary uroporphyrin levels were elevated. Based on the clinical manifestations, the history and laboratory findings, a diagnosis of PCT was made. The cutaneous and biochemical abnormalities of the patient improved with therapy of glycyrrhizin.

What is impact of nonsteroidal anti-inflammatory drugs in the prevention of post-endoscopic retrograde cholangiopancreatography pancreatitis: a meta-analysis of randomized controlled trials.

BACKGROUND: Recently, although studies have investigated the role of NSAIDs in the prevention of post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP), selection of the ideal drug, the time and route of its administration for the appropriate population remain controversial. METHODS: A systematic search was done in sources including PubMed, Embase, Web of Science, the Cochrane Library Central, and ClinicalTrials.gov from from August 1, 1990 to August 1, 2017. Randomized controlled trials comparing the prophylactic use of NSAIDs versus a placebo were included. Statistical analysis was performed using the RevMan 5.3 software to assess the outcomes. RESULTS: A total of 21 randomized controlled trials were included in the meta-analysis. Our study showed that NSAIDs significantly reduced the incidence of PEP (RR, 0.61, 95%CI,0.52-0.72; p < 0.00001). The analysis showed that indomethacin administration post-ERCP (RR, 0.47; 95% CI, 0.31-0.70; p = 0.0002) appeared to be more effective in preventing PEP than indomethacin administration pre-ERCP (RR, 0.59; 95% CI, 0.45-0.79; P = 0.0003), but there was no significant difference between the high-risk and average-risk population(p = 0.13). In the diclofenac group, it was noted that administration of diclofenac pre-ERCP (RR, 0.32; 95% CI, 0.16-0.63; p = 0.001) was more effective than that in post-ERCP (RR, 0.65; 95% CI, 0.27-1.599; p = 0.35). The relative risk of PEP was 0.63 (95% CI, 0.27-1.50; p = 0.30) in high-risk patients and 0.41 (95% CI, 0.17-0.98; p = 0.02) in average-risk patients. With regard to the route of administration, PEP decreased significantly only in patients receiving the drug rectally (RR, 0.53; 95% CI, 0.44-0.63; p < 0.00001), but not for those who received intramuscularly (RR, 0.74; 95% CI, 0.47-1.17; p = 0.20), intravenously (RR, 0.97; 95% CI, 0.51-1.83; p = 0.93), and orally (RR = 0.88; 95% CI, 0.55-0.1.43; p = 0.62). CONCLUSIONS: Rectal administration of NSAIDs (both indomethacin and diclofenac) was effective in preventing PEP in unselected patients. A single dose of indomethacin after ERCP might be effective in preventing PEP in both high-risk and average-risk patients. However, diclofenac administered rectally before ERCP might be protective against PEP in high-risk patients compared to a placebo. However, more high quality head-to-head RCTs are required.

Premature Progesterone Rise Positively Correlates with Clinical Pregnancy Rate in In Vitro Fertilization (IVF) and Intracytoplasmic Sperm Injection (ICSI) Patients with good Ovarian Response.

Infertility affects millions of couples worldwide resulting in distress and depression. In the past several decades, in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) have been developed with high efficiency and success rate. The possible effects of gonadotropin administration on follicular metabolism have been discussed but the outcomes remain controversial. The aim of this study was to identify whether serum progesterone on the day of human chorionic gonadotropin (hCG) administration and the ratio of serum progesterone and the number of oocyte retrieved (P/O) had a predictive role for the outcomes of IVF/ICSI. Eight hundred and twenty-five patients were enrolled between January 2012 and December 2012. A positive correlation between progesterone and IVF/ICSI outcomes were found in patients with good ovarian response using receiver operating characteristic (ROC) curve. We found that when progesterone level was higher than 1.04 ng/ml in good ovarian responses, the implantation rate and clinical pregnancy rate were both reduced compared to the rates in patients exhibiting lower progesterone level (progesterone≤1.04 ng/ml). Moreover, the rise of serum progesterone on the day of hCG was negatively correlated with luteinizing hormone (LH) level. This study used 1.04 ng/ml as a definition of progesterone elevation and an adverse effect of serum progesterone rise was observed on clinical pregnancy rate.

Decreased expression of fatty acid amide hydrolase in women with polycystic ovary syndrome.

This study aimed to investigate the correlation between endocannabinoids and polycystic ovary syndrome (PCOS), and the expression levels of endocannabinoids in different phases of menstruation. The expression of cannabinoid receptors (CB1) and fatty acid amide hydrolase (FAAH) in the endometrium were immunohistochemically stained and compared between women with PCOS and the control group. Integrated optical density (IOD) was assessed to analyze their expression levels. The CB1 and FAAH were expressed in endometrial epithelial cytoplasm. No significant difference in CB1 level was observed between PCOS and non-PCOS women. Additionally, the expression of CB1 did not fluctuate with menstrual cycle. However, the FAAH levels were lower in the PCOS group than the non-PCOS group (p < 0.05). FAAH levels in secretory phases were significantly elevated compared to menstrual and proliferative phases (p < 0.05). Our results demonstrate that the endocannabinoid system may play an important role in menstruation, and dysregulation of the system may result in PCOS.

Impact of Body Mass Index on Outcomes of In Vitro Fertilization/Intracytoplasmic Sperm Injection Among Polycystic Ovarian Syndrome Patients.

BACKGROUND: The aim of this study is to assess the effect of body mass index (BMI) on outcomes of in vitro fertilization (IVF) / intracytoplasmic sperm injection (ICSI) among polycystic ovarian syndrome (PCOS) and non-PCOS patients. METHODS: This was a retrospective cohort study that was performed in the Second Hospital of Hebei Medical University. Patients who were under 35 years old were included in the study and were divided into four groups based on their BMI. The number of retrieved oocytes, implantation rate, clinical pregnancy rate, miscarriage rate and live births among PCOS and non-PCOS patients were compared between different BMIs. RESULTS: IVF/ICSI pregnancies in obese PCOS women had a considerably higher risk of miscarriage and low rate of clinical pregnancy than in non-obese PCOS pregnancies. However, in non-PCOS patient, obesity significantly elevated miscarriage rate but did not affect clinical pregnancy rate. CONCLUSION: Obesity in PCOS patients led to poor outcomes of IVF/ICSI.

Nitric Oxide Regulation of Bacterial Biofilms.

Biofilms are surface-associated, multicellular communities of bacteria. Once established, they are extremely difficult to eradicate by antimicrobial treatment. It has been demonstrated in many species that biofilm formation may be regulated by the diatomic signaling molecule nitric oxide (NO). Although this is still a relatively new area of research, we review here the literature reporting an effect of NO on bacterial biofilm formation, emphasizing dose-dependent responses to NO concentrations when possible. Where it has been investigated, the underlying NO sensors or signaling pathways are also discussed. Most of the examples of NO-mediated biofilm regulation have been documented with exogenously applied NO, but we also survey possible natural sources of NO in biofilm regulation, including endogenously generated NO. Finally, because of the apparent broad-spectrum, antibiofilm effects of NO, NO-releasing materials and prodrugs have also been explored in this minireview.

Iron-catalyzed radical aryldifluoromethylation of activated alkenes to difluoromethylated oxindoles.

An iron-catalyzed aryldifluoromethylation of activated alkenes under mild reaction conditions has been developed, which is a rare example where a cosolvent is used to improve the reaction yield along with Fenton's reagent and thus provides an economic and green method for the synthesis of a variety of difluoromethylated oxindoles. Preliminary mechanistic investigations indicate a radical addition path.

In vivo microdialysis for the evaluation of transfersomes as a novel transdermal delivery vehicle for cinnamic acid.

In this study, cinnamic acid-loaded transfersomes were prepared and dermal microdialysis sampling was used in Sprague-Dawley rats to compare the amount of drug released into the skin using transfersomes as transdermal carriers with that released on using conventional liposomes. The formulation of cinnamic acid-loaded transfersomes was optimized by a uniform design through in vitro transdermal permeation studies. Hydration time was confirmed as a significant factor influencing the entrapment efficiency of transfersomes, further affecting their transdermal flux in vitro. The fluxes of cinnamic acid from transfersomes were all higher than those from conventional liposomes, and the flux from the optimal transfersome formulation was 3.01-fold higher than that from the conventional liposomes (p < 0.05). An in vivo microdialysis sampling method revealed that the dermal drug concentrations from transfersomes applied on various skin regions were much lower than those required with conventional liposomes. After the administration of drug-containing transfersomes and liposomes on abdominal skin regions of rats for a period of 10 h, the Cmax of cinnamic acid from the compared liposomes was 3.21 ± 0.25 µg/mL and that from the transfersomes was merely 0.59 ± 0.02 µg/mL. The results suggest that transfersomes can be used as carriers to enhance the transdermal delivery of cinnamic acid, and that these vehicles may penetrate the skin in the complete form, given their significant deformability.

Structural insight into CD93 recognition by IGFBP7.

The CD93/IGFBP7 axis proteins are key factors expressed in endothelial cells (EC) that mediate EC angiogenesis and migration. Their upregulation contributes to tumor vascular abnormality and a blockade of this interaction promotes a favorable tumor microenvironment for therapeutic interventions. However, the interactions of these proteins with each other remain unclear. In this study, we determined a partial structure of the human CD93-IGFBP7 complex comprising the EGF1 domain of CD93 and the IB domain of IGFBP7. Mutagenesis studies confirmed interactions and specificities. Cellular and mouse tumor studies demonstrated the physiological relevance of the CD93-IGFBP7 interaction in EC angiogenesis. Our study provides leads for the development of therapeutic agents to precisely disrupt unwanted CD93-IGFBP7 signaling in the tumor microenvironment. Additionally, analysis of the CD93 full-length architecture provides insights into how CD93 protrudes on the cell surface and forms a flexible platform for binding to IGFBP7 and other ligands.

Structural insight into the dual-antagonistic mechanism of AB928 on adenosine A2 receptors.

The adenosine subfamily G protein-coupled receptors A2AR and A2BR have been identified as promising cancer immunotherapy candidates. One of the A2AR/A2BR dual antagonists, AB928, has progressed to a phase II clinical trial to treat rectal cancer. However, the precise mechanism underlying its dual-antagonistic properties remains elusive. Herein, we report crystal structures of the A2AR complexed with AB928 and a selective A2AR antagonist 2-118. The structures revealed a common binding mode on A2AR, wherein the ligands established extensive interactions with residues from the orthosteric and secondary pockets. In contrast, the cAMP assay and A2AR and A2BR molecular dynamics simulations indicated that the ligands adopted distinct binding modes on A2BR. Detailed analysis of their chemical structures suggested that AB928 readily adapted to the A2BR pocket, while 2-118 did not due to intrinsic differences. This disparity potentially accounted for the difference in inhibitory efficacy between A2BR and A2AR. This study serves as a valuable structural template for the future development of selective or dual inhibitors targeting A2AR/A2BR for cancer therapy.

A nitric oxide-responsive quorum sensing circuit in Vibrio harveyi regulates flagella production and biofilm formation.

Cell signaling plays an important role in the survival of bacterial colonies. They use small molecules to coordinate gene expression in a cell density dependent manner. This process, known as quorum sensing, helps bacteria regulate diverse functions such as bioluminescence, biofilm formation and virulence. In Vibrio harveyi, a bioluminescent marine bacterium, four parallel quorum-sensing systems have been identified to regulate light production. We have previously reported that nitric oxide (NO), through the H-NOX/HqsK quorum sensing pathway contributes to light production in V. harveyi through the LuxU/LuxO/LuxR quorum sensing pathway. In this study, we show that nitric oxide (NO) also regulates flagellar production and enhances biofilm formation. Our data suggest that V. harveyi is capable of switching between lifestyles to be able to adapt to changes in the environment.