A new invertebrate NPY-like polypeptide, ZoaNPY, from the Zoanthus sociatus, as a novel ligand of human NPY Y2 receptor rescues vascular insufficiency via PLC/PKC and Src- FAK-dependent signaling pathways.

Our recent multi-omics studies have revealed rich sources of novel bioactive proteins and polypeptides from marine organisms including cnidarians. In the present study, we initially conducted a transcriptomic analysis to review the composition profile of polypeptides from Zoanthus sociatus. Then, a newly discovered NPY-like polypeptide-ZoaNPY was selected for further in silico structural, binding and virtually pharmacological studies. To evaluate the pro-angiogenic effects of ZoaNPY, we employed an in vitro HUVECs model and an in vivo zebrafish model. Our results indicate that ZoaNPY, at 1-100 pmol, enhances cell survival, migration and tube formation in the endothelial cells. Besides, treatment with ZoaNPY could restore a chemically-induced vascular insufficiency in zebrafish embryos. Western blot results demonstrated the application of ZoaNPY could increase the phosphorylation of proteins related to angiogenesis signaling including PKC, PLC, FAK, Src, Akt, mTOR, MEK, and ERK1/2. Furthermore, through molecular docking and surface plasmon resonance (SPR) verification, ZoaNPY was shown to directly and physically interact with NPY Y2 receptor. In view of this, all evidence showed that the pro-angiogenic effects of ZoaNPY involve the activation of NPY Y2 receptor, thereby activating the Akt/mTOR, PLC/PKC, ERK/MEK and Src- FAK-dependent signaling pathways. Furthermore, in an excision wound model, the treatment with ZoaNPY was shown to accelerate the wound healing process in mice. Our findings provide new insights into the discovery and development of novel pro-angiogenic drugs derived from NPY-like polypeptides in the future.

Endoscopic incisional therapy for benign anastomotic strictures after esophagectomy or gastrectomy: a systematic review and meta-analysis.

BACKGROUND: Studies have evaluated the efficacy of endoscopic incisional therapy (EIT) for benign anastomotic strictures. We performed a systematic review and meta-analysis to evaluate stricture recurrence after EIT following esophagectomy or gastrectomy. METHODS: A systematic search of databases was performed up to April 2nd, 2023, after selection of key search terms with the research team. Inclusion criteria included human participants undergoing EIT for a benign anastomotic stricture after esophagectomy or gastrectomy, age ≥ 18, and n ≥ 5. Our primary outcome was the incidence of stricture recurrence among patients treated with EIT compared to dilation. Our secondary outcome was the stricture-free duration after EIT and rate of adverse events. Meta-analysis was performed with RevMan 5.4.1 using a Mantel-Haenszel random-effects model. Publication bias was evaluated with funnel plots and the Egger test. RESULTS: A total of 2550 unique preliminary studies underwent screening of abstracts and titles. This led to 33 studies which underwent full-text review and five studies met the inclusion criteria. Meta-analysis revealed reduced odds of overall stricture recurrence (OR 0.35, 95% CI 0.13-0.92, p = 0.03; I2 = 71%) and reduced odds of stricture recurrence among naïve strictures (OR 0.32, 95% CI 0.17-0.59, p = 0.0003; I2 = 0%) for patients undergoing EIT compared to dilation. There was no significant difference in the odds of stricture recurrence among recurrent strictures (OR 0.63, 95% CI 0.12-3.28, p = 0.58; I2 = 81%). Meta-analysis revealed a significant increase in the recurrence-free duration (MD 42.76, 95% CI 12.41-73.11, p = 0.006) among patients undergoing EIT compared to dilation. CONCLUSION: Current data suggest EIT is associated with reduced odds of stricture recurrence among naïve anastomotic strictures. Large, prospective studies are needed to characterize the safety profile of EIT, address publication bias, and to explore multimodal therapies for refractory strictures.

Improved Survival in a Cohort of Patients Aged 75 Years and Older With Fecal Immunochemical Testing-Detected Colorectal Cancer.

BACKGROUND: Fecal immunochemical testing is an accepted form of colorectal cancer screening and is recommended for adults up to the age of 75 years in Canadian guidelines. However, many individuals 75 years and older continue to receive fecal immunochemical testing despite being outside accepted guidelines. OBJECTIVE: This study aimed to determine whether patients aged 75 years and older with screen-detected cancer demonstrated improved outcomes and survival compared with patients with non-screen-detected cancer. DESIGN: This is a retrospective population-based cohort study. SETTINGS: Provincial data were collected from the Alberta Cancer Registry and the Alberta Colorectal Cancer Screening Program between November 2013 and 2019. PATIENTS: We identified an aggregated patient cohort aged 75 years and older with a diagnosis of colorectal cancer from November 2013 to November 2019, as well as patients 75 years and older who underwent fecal immunochemical testing within these dates. MAIN OUTCOME MEASURES: The proportion of screen-detected colorectal cancers was calculated. Surgical intervention, hospital length of stay, postoperative mortality, and overall survival were analyzed. RESULTS: Between November 2013 and 2019, 3586 patients 75 years and older were diagnosed with colorectal cancer; 690 (19%) were "screen-detected." Screen-detected patients were almost 3 times more likely to undergo surgery (OR, 2.83) and had a 36% overall survival benefit (HR, 0.64) compared with non-screen-detected patients, adjusted for other variables such as age, Charlson Comorbidity Index, and stage. LIMITATIONS: The retrospective study design prevents conclusions regarding causation. CONCLUSIONS: Screen detection of colorectal cancer in patients aged 75 years and older is associated with improved overall survival when controlling for other potential confounders. When compared with their non-screen-detected counterparts, these patients have an earlier stage of disease and are more likely to undergo surgical intervention with improved outcomes, irrespective of age. These data may support screening for appropriately selected patients who would otherwise fall outside of current guidelines. See Video Abstract at http://links.lww.com/DCR/B986 . SOBREVIDA MEJORADA EN UNA COHORTE DE PACIENTES DE AOS O MS CON CNCER COLORRECTAL DETECTADOS POR RIF: ANTECEDENTES:La prueba basada en una Reacción Inmunoquímica Fecal - RIF, es una forma aceptada de detección de cáncer colorrectal y esta recomendada en adultos a partir de los 75 años en las guías canadienses. Sin embargo, muchas personas de 75 años o más continúan realizándose pruebas inmunoquímicas fecales a pesar de estar fuera de las guías aceptadas.OBJETIVO:Poder determinar si los pacientes de 75 años o más con detección RIF positiva a un cáncer demuestran mejores resultados y sobrevida comparados con los pacientes sin detección.DISEÑO:Estudio de cohortes retrospectivo basado en una población definida.CONFIGURACIÓN:Se recopilaron los datos provinciales del Registro de cánceres y del Programa de detección de cáncer colorrectal de Alberta, Canada, entre 2013 y 2019.PACIENTES:Identificamos una cohorte agregada de pacientes de 75 años o más con diagnóstico de cáncer colorrectal desde noviembre de 2013 hasta noviembre de 2019, así como pacientes de 75 años o más que se sometieron a pruebas inmunoquímicas fecales dentro de las fechas mencionadas.PRINCIPALES MEDIDAS DE RESULTADO:Se calculó la proporción de cánceres colorrectales detectados mediante un cribado. Se analizaron la intervención quirúrgica, la duración de la estadía hospitalaria, la mortalidad post-operatoria y la sobrevida global.RESULTADOS:Entre noviembre de 2013 y noviembre 2019, 3586 pacientes de 75 años o más, fueron diagnosticados con cáncer colorrectal; 690 (19%) fueron detectados por cribado. Los pacientes detectados mediante el cribado, tenían casi tres veces más probabilidades de someterse a una cirugía (Razón de Probabilidad de 2,83) y beneficiaron de una sobrevida general del 36 % (HR 0,64) comparados con los pacientes sin detectación por cribado, corregidos por otras variables como la edad, el índice de comorbilidad de Charlson y el estadío del tumor.LIMITACIONES:El diseño retrospective del presente estudio impide obtener conclusiones con respecto a la causalidad.CONCLUSIONES:La detección por cribado de cáncer colorrectal en pacientes de 75 años o más se asocia con una mejor sobrevida general cuando se controlan los otros posibles factores de confusión. Comparando con las contrapartes no detectadas por cribado, estos pacientes se encuentran en una etapa más temprana de la enfermedad y es más probable que se sometan a una intervención quirúrgica con mejores resultados, independientemente a la edad. Estos datos pueden respaldar la detección de pacientes adecuadamente seleccionados que, de otro modo, quedarían fuera de las pautas actuales. Consulte Video Resumen en http://links.lww.com/DCR/B986 . (Traducción-Dr. Xavier Delgadillo ).

Optimizing management for early-stage esophageal adenocarcinoma: longitudinal results from a multidisciplinary program.

BACKGROUND: The management of early-stage esophageal cancer is nuanced. A multidisciplinary approach may optimize management through selection of candidates for surgical or endoscopic therapies. The objective of this research was to examine long-term outcomes of patients with early-stage esophageal cancer who undergo treatment with endoscopic resection or surgery. METHODS: Data on patient demographics, co-morbidities, pathology results, OS and RFS were obtained for both the endoscopic resection group and esophagectomy group. Univariate analysis of OS and RFS were conducted using the Kaplan-Meier method with calculation of the log-rank test. Multivariate cox-proportional hazards models were created for OS and RFS using a hypothesis-driven approach. A multivariate logistic regression model was created to identify predictors of esophagectomy among patients undergoing initial endoscopic resection. RESULTS: A total of 111 patients were included. The median OS for the surgery group was 67.0 months compared to 74.0 months in the endoscopic resection group (log-rank p = 0.93). The median RFS for the surgery group was 109.4 months compared to 63.3 months in the endoscopic resection group (log-rank p = 0.0127). On multivariable analysis, patients undergoing endoscopic resection had significantly worse RFS (HR 2.55, 95% CI 1.09-6.00; p = 0.032), but equivalent OS (HR 1.03, 95% CI 0.46-2.32; p = 0.941), compared to patients undergoing esophagectomy. High-grade disease (OR 5.43, 95% CI 1.13-26.10; p = 0.035) and submucosal involvement (OR 7.75, 95% CI 1.90-31.40; p = 0.004) were identified as significant predictors of proceeding to esophagectomy. CONCLUSIONS: Through a multidisciplinary approach, patients with early-stage esophageal cancer achieve excellent RFS and OS. Submucosal involvement and high-grade disease place patients at increased risk for local disease recurrence; these patients may undergo endoscopic resection safely if treated with a multidisciplinary approach incorporating endoscopic surveillance and surgical consultation. Further risk-stratification models may enable better patient selection and optimization of long-term outcomes.

Endoscopic plication compared to laparoscopic fundoplication in the treatment of gastroesophageal reflux disease: a systematic review and meta-analysis.

INTRODUCTION: Endoscopic plication offers an alternative to surgical fundoplication for treatment of gastroesophageal reflux disease (GERD). This systematic review and meta-analysis evaluate outcomes following endoscopic plication compared to laparoscopic fundoplication. METHODS AND PROCEDURES: Systematic search of MEDLINE, Embase, Scopus, and Web of Science was conducted in September 2022. Study followed PRISMA guidelines. Studies comparing endoscopic plication to laparoscopic fundoplication with n > 5 were included. Primary outcome was PPI cessation, with secondary outcomes including complications, procedure duration, length of stay, change in lower esophageal sphincter (LES) tone, and DeMeester score. RESULTS: We reviewed 1544 studies, with five included comparing 105 (46.1%) patients receiving endoscopic plication (ENDO) to 123 (53.9%) undergoing laparoscopic fundoplication (LAP). Average patient age was 47.6 years, with those undergoing plication being younger (46.4 ENDO vs 48.5 LAP). BMI (26.6 kg/m2 ENDO vs 26.2 kg/m2 LAP), and proportion of females (42.9% ENDO vs 37.4% LAP) were similar. Patients undergoing laparoscopic procedures had worse baseline LES pressure (12.8 mmHg ENDO vs 9.0 mmHg LAP) and lower preoperative DeMeester scores (34.6 ENDO vs. 34.1 LAP). The primary outcome demonstrated that 89.2% of patients undergoing laparoscopic fundoplication discontinued PPI compared to 69.4% for those receiving plication. Meta-analysis revealed that plication had significantly reduced odds of PPI discontinuation (OR 0.27, studies = 3, 95% CI 0.12 to 0.64, P = 0.003, I2 = 0%). Secondary outcomes demonstrated that odds of complications (OR 1.46, studies = 4, 95% CI 0.34 to 6.32, P = 0.62, I2 = 0%), length of stay (MD - 1.37, studies = 3, 95% CI - 3.48 to 0.73, P = 0.20, I2 = 94%), and procedure durations were similar (MD 0.78, studies = 3, 95% CI - 39.70 to 41.26, P = 0.97, I2 = 98%). CONCLUSIONS: This is the first meta-analysis comparing endoscopic plication to laparoscopic fundoplication. Results demonstrate greater likelihood of PPI discontinuation with laparoscopic fundoplication with similar post-procedural risk.

Toward Precise Antitumoral Photodynamic Therapy Using a Dual Receptor-Mediated Bioorthogonal Activation Approach.

Targeted delivery and specific activation of photosensitizers can greatly improve the treatment outcome of photodynamic therapy. To this end, we report herein a novel dual receptor-mediated bioorthogonal activation approach to enhance the tumor specificity of the photodynamic action. It involves the targeted delivery of a biotinylated boron dipyrromethene (BODIPY)-based photosensitizer, which is quenched in the native form by the attached 1,2,4,5-tetrazine unit, and an epidermal growth factor receptor (EGFR)-targeting cyclic peptide conjugated with a bicycle[6.1.0]non-4-yne moiety. Only for cancer cells that overexpress both the biotin receptor and EGFR, the two components can be internalized preferentially where they undergo an inverse electron-demand Diels-Alder reaction, leading to restoration of the photodynamic activity of the BODIPY core. By using a range of cell lines with different expression levels of these two receptors, we have demonstrated that this stepwise "deliver-and-click" approach can confine the photodynamic action on a specific type of cancer cells.

Specific Activation of Photosensitizer with Extrinsic Enzyme for Precisive Photodynamic Therapy.

Delivery of functional proteins into the intracellular space has been a challenging task that could lead to a myriad of therapeutic applications. We report herein a novel bioconjugation strategy for enzyme modification and selective delivery into cancer cells for lock-and-key-type activation of photosensitizers. Using a bifunctional linker containing a bis(bromomethyl)phenyl group and an o-phthalaldehyde moiety, it could induce cyclization of the peptide sequence Ac-NH-CRGDfC-CONH2 through site-specific dibenzylation with the two cysteine residues and further coupling with ß-galactosidase via the phthalaldehyde-amine capture reaction. This facile two-step one-pot procedure enabled the preparation of cyclic RGD-modified ß-galactosidase readily, which could be internalized selectively into αvß3 integrin-overexpressed cancer cells. Upon encountering an intrinsically quenched distyryl boron dipyrromethene-based photosensitizer conjugated with a galactose moiety through a self-immolative linker inside the cells, the extrinsic enzyme induced specific cleavage of the ß-galactosidic bond followed by self-immolation to release an activated derivative, thereby restoring the photodynamic activities and causing cell death effectively. The high specificity of this extrinsic enzyme-activated photosensitizing system was also demonstrated in vivo using nude mice bearing an αvß3 integrin-positive U87-MG tumor. The specific activation at the tumor site resulted in lighting up and complete eradication of the tumor upon laser irradiation, while by using the native ß-galactosidase, the effects were largely reduced. In contrast to the conventional activation using intrinsic enzymes, this extrinsic enzyme activatable approach can further minimize the nonspecific activation toward precisive photodynamic therapy.

Endoscopic ultrasound (EUS)-guided fine needle biopsy alone vs. EUS-guided fine needle aspiration with rapid onsite evaluation in pancreatic lesions: a multicenter randomized trial.

BACKGROUND: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the standard in the diagnosis of solid pancreatic lesions, in particular when combined with rapid onsite evaluation of cytopathology (ROSE). More recently, a fork-tip needle for core biopsy (FNB) has been shown to be associated with excellent diagnostic yield. EUS-FNB alone has however not been compared with EUS-FNA + ROSE in a large clinical trial. Our aim was to compare EUS-FNB alone to EUS-FNA + ROSE in solid pancreatic lesions. METHODS: A multicenter, non-inferiority, randomized controlled trial involving seven centers was performed. Solid pancreatic lesions referred for EUS were considered for inclusion. The primary end point was diagnostic accuracy. Secondary end points included sensitivity/specificity, mean number of needle passes, and cost. RESULTS: 235 patients were randomized: 115 EUS-FNB alone and 120 EUS-FNA + ROSE. Overall, 217 patients had malignant histology. The diagnostic accuracy for malignancy of EUS-FNB alone was non-inferior to EUS-FNA + ROSE at 92.2 % (95 %CI 86.6 %-96.9 %) and 93.3 % (95 %CI 88.8 %-97.9 %), respectively (P = 0.72). Diagnostic sensitivity for malignancy was 92.5 % (95 %CI 85.7 %-96.7 %) for EUS-FNB alone vs. 96.5 % (93.0 %-98.6 %) for EUS-FNA + ROSE (P = 0.46), while specificity was 100 % in both. Adequate histological yield was obtained in 87.5 % of the EUS-FNB samples. The mean (SD) number of needle passes and procedure time favored EUS-FNB alone (2.3 [0.6] passes vs. 3.0 [1.1] passes [P < 0.001]; and 19.3 [8.0] vs. 22.7 [10.8] minutes [P = 0.008]). EUS-FNB alone cost on average 45 US dollars more than EUS-FNA + ROSE. CONCLUSION: EUS-FNB alone is non-inferior to EUS-FNA + ROSE and is associated with fewer needle passes, shorter procedure time, and excellent histological yield at comparable cost.

Anti-epileptic Kunitz-like peptides discovered in the branching coral Acropora digitifera through transcriptomic analysis.

Approximately 50 million people are suffering from epilepsy worldwide. Corals have been used for treating epilepsy in traditional Chinese medicine, but the mechanism of this treatment is unknown. In this study, we analyzed the transcriptome of the branching coral Acropora digitifera and obtained its Kyoto Encyclopedia of Genes and Genomes (KEGG), EuKaryotic Orthologous Groups (KOG) and Gene Ontology (GO) annotation. Combined with multiple sequence alignment and phylogenetic analysis, we discovered three polypeptides, we named them AdKuz1, AdKuz2 and AdKuz3, from A. digitifera that showed a close relationship to Kunitz-type peptides. Molecular docking and molecular dynamics simulation indicated that AdKuz1 to 3 could interact with GABAA receptor but AdKuz2-GABAA remained more stable than others. The biological experiments showed that AdKuz1 and AdKuz2 exhibited an anti-inflammatory effect by decreasing the aberrant level of nitric oxide (NO), IL-6, TNF-α and IL-1ß induced by LPS in BV-2 cells. In addition, the pentylenetetrazol (PTZ)-induced epileptic effect on zebrafish was remarkably suppressed by AdKuz1 and AdKuz2. AdKuz2 particularly showed superior anti-epileptic effects compared to the other two peptides. Furthermore, AdKuz2 significantly decreased the expression of c-fos and npas4a, which were up-regulated by PTZ treatment. In addition, AdKuz2 reduced the synthesis of glutamate and enhanced the biosynthesis of gamma-aminobutyric acid (GABA). In conclusion, the results indicated that AdKuz2 may affect the synthesis of glutamate and GABA and enhance the activity of the GABAA receptor to inhibit the symptoms of epilepsy. We believe, AdKuz2 could be a promising anti-epileptic agent and its mechanism of action should be further investigated.

Recommendations for the Management of Incidental Pancreatic Findings in Adults by the Canadian Association of Radiologists Incidental Findings Working Group.

The Canadian Association of Radiologists Incidental Findings Working Group consists of both academic subspecialty and general radiologists and is tasked with adapting and expanding upon the American College of Radiology incidental findings white papers to more closely apply to Canadian practice patterns, particularly more comprehensively dealing with the role of ultrasound and pursuing more cost-effective approaches to the workup of incidental findings without compromising patient care. Presented here are the 2021 Canadian guidelines for the management of pancreatic incidental findings. Topics covered include anatomic variants, fatty atrophy, pancreatic calcifications, ductal ectasia, and management of incidental pancreatic cysts.

Surgical management of hiatal hernia vs medical therapy to treat bleeding Cameron lesions: a systematic review and meta-analysis.

INTRODUCTION: Cameron lesions (CL) are an under-recognized cause of gastrointestinal bleeding. Diagnosis is often impaired by technical difficulty, and once diagnosed, management remains unclear. Typically, patients are medically managed with proton pump inhibitors (PPI). Small studies have demonstrated improved therapeutic success with surgical management, hypothesizing that reversing mechanical gastric trauma and ischemia allows CL healing. This systematic review and meta-analysis aim to compare therapeutic success of surgical versus medical management of Cameron lesions (CL). METHODS AND PROCEDURES: A comprehensive search and systematic review selected manuscripts using the following inclusion criteria: (1) Endoscopically diagnosed CL (2) Treated surgically (3) Follow-up for resolution of anemia or CL (4) n ≥ 5 (5) Excluding non-English, animal, and studies with patients < 18 years old Meta-analysis was performed to compare resolution of CLs with medical and surgical therapy. RESULTS: Systematic search retrieved 1664 studies, of these, 14 were included (randomized controlled trial = 1; prospective = 2; retrospective = 11). Patients had a mean age of 61.2 years (range 24-91) and were more often female (59.3%). Follow-up was between 3 and 120 months, and 82.9% of patients had hernias > 5 cm. Surgical management was associated with therapeutic success (OR 5.20, 1.83-14.77, I2 = 42%, p < 0.001) with 92% having resolution, compared to 67.2% for those treated with PPI. Surgical complications occurred in 42/109 (38.5%) of patients (48.1% for Open Hill Repair, 15.4% for laparoscopic fundoplication). 40.0% of patients underwent a laparoscopic Nissen or Collis fundoplication, 21.7% underwent open modified Hill repair, and 38.3% had unspecified operations. Hemoglobin improved from 8.85 g/dL pre-operatively to 13.60 g/dL post-operatively. In six studies, surgical patients previously failed medical management. CONCLUSIONS: This is the first systematic review comparing surgical and medical treatment of CL. Surgical management significantly improved therapeutic success. Our study supports therapeutic benefit of surgery in these patients.

Association Between Endoscopist Annual Procedure Volume and Colonoscopy Quality: Systematic Review and Meta-analysis.

BACKGROUND & AIMS: In addition to monitoring adverse events (AEs) and post-colonoscopy colorectal cancers (PCCRC), indicators for assessing colonoscopy quality include adenoma detection rate (ADR) and cecal intubation rate (CIR). It is unclear whether there is an association between annual colonoscopy volume and ADR, CIR, AEs, or PCCRC. METHODS: We searched publication databases through March 2019 for studies assessing the relationship between annual colonoscopy volume and outcomes, including ADR, CIR, AEs, or PCCRC. Pooled odds ratios (ORs) were calculated using DerSimonian and Laird random effects models. Sensitivity analyses were performed to assess for potential methodological or clinical factors associated with outcomes. RESULTS: We performed a systematic review of 9235 initial citations, generating 27 retained studies comprising 11,276,244 colonoscopies. There was no association between procedural volume and ADR (OR, 1.00; 95% CI, 0.98-1.02 per additional 100 annual procedures). CIR improved with each additional 100 annual procedures (OR, 1.17; 95% CI, 1.08-1.28). There was a non-significant trend toward decreased overall AEs per additional 100 annual procedures (OR, 0.95; 95% CI, 0.90-1.00). There was considerable heterogeneity among most analyses. CONCLUSIONS: In a systematic review and meta-analysis, we found higher annual colonoscopy volumes to correlate with higher CIR, but not with ADR or PCCRC. Trends toward fewer AEs were associated with higher annual colonoscopy volumes. There are few data available from endoscopists who perform fewer than 100 annual colonoscopies. Studies are needed on extremes in performance volumes to more clearly elucidate associations between colonoscopy volumes and outcomes.

Chemoselective Peptide Cyclization and Bicyclization Directly on Unprotected Peptides.

Cyclic peptides are drawing wide attention as potential medium-sized modulators of biomolecular interactions with large binding surfaces. Simple but effective peptide cyclization methods are needed to construct cyclic peptide libraries by both peptide and nonpeptide chemists. Herein, we report a highly chemoselective and operation-simple method directly cyclizing unprotected peptides, in which ortho-phthalaldehyde (OPA) is found to react with the lysine/N-terminus and cysteine within one unprotected peptide sequence effectively to form the isoindole-bridged cyclic peptides. This reaction is carried out in the aqueous buffer and features tolerance of diverse functionalities, rapid and clean transformation, and operational simplicity. In addition, OPA peptide cyclization can also be combined with native chemical ligation-mediated cyclization to generate bicyclic peptides. Furthermore, the OPA peptide cyclization product can further react with the N-maleimide moiety in a one-pot manner to introduce additional functional motifs, like a fluorophore probe, biomolecules (e.g., glycan, peptide, or DNA). This OPA-cyclization method extends the toolbox for integrating postcyclization modification and bioconjugation into peptide cyclization with an all-in-one manner strategy.

Novel neurotoxic peptides from Protopalythoa variabilis virtually interact with voltage-gated sodium channel and display anti-epilepsy and neuroprotective activities in zebrafish.

We previously reported a novel toxic peptide identified from the anthozoan Protopalythoa variabilis transcriptome which is homologous to a novel structural type of sodium channel toxin isolated from a parental species (Palythoa caribaeorum). The peptide was named, according to its homologous, as Pp V-shape α-helical peptide (PpVα) in the present study. Through molecular docking and dynamics simulation, linear and hairpin folded PpVα peptides were shown to be potential voltage-gated sodium channel blockers. Nowadays, sodium channel blockers have been the mainstream of the pharmacological management of epileptic seizures. Also, sodium channel blockers could promote neuronal survival by reducing sodium influx and reducing the likelihood of calcium importation resulting in suppressing microglial activation and protecting dopaminergic neurons from degeneration. The folded PpVα peptide could decrease pentylenetetrazol (PTZ)-induced c-fos and npas4a expression level leading to reverse PTZ-induced locomotor hyperactivity in zebrafish model. In vitro, the folded PpVα peptide protected PC12 cells against 6-hydroxydopamine (6-OHDA)-induced neurotoxicity via activating heme oxygenase-1 (HO-1) and attenuating inducible nitric oxide synthase (iNOS) expression. In vivo, PpVα peptide suppressed the 6-OHDA-induced neurotoxicity on the locomotive behavior of zebrafish and, importantly, prevented the 6-OHDA-induced excessive ROS generation and subsequent dopaminergic neurons loss. This study indicates that the single S-S bond folded PpVα peptide arises as a new structural template to develop sodium channel blockers and provides an insight on the peptide discovery from cnidarian transcriptome to potentially manage epilepsy and neurodegenerative disorders.

Combined transcriptomic and proteomic analysis reveals a diversity of venom-related and toxin-like peptides expressed in the mat anemone Zoanthus natalensis (Cnidaria, Hexacorallia).

Venoms from marine animals have been recognized as a new emerging source of peptide-based therapeutics. Several peptide toxins from sea anemone have been investigated as therapeutic leads or pharmacological tools. Venom complexity should be further highlighted using combined strategies of large-scale sequencing and data analysis which integrated transcriptomics and proteomics to elucidate new proteins or peptides to be compared among species. In this work, transcriptomic and proteomic analyses were combined to identify six groups of expressed peptide toxins in Zoanthus natalensis. These include neurotoxin, hemostatic and hemorrhagic toxin, protease inhibitor, mixed function enzymes, venom auxiliary proteins, allergen peptides, and peptides related to the innate immunity. Molecular docking analysis indicated that one expressed Zoanthus Kunitz-like peptide, ZoaKuz1, could be a voltage-gated potassium channels blocker and, hence, it was selected for functional studies. Functional bioassays revealed that ZoaKuz1 has an intrinsic neuroprotective activity in zebrafish model of Parkinson's disease. Since pharmacological blockade of KV channels is known to induce neuroprotective effects, ZoaKuz1 holds the potential to be developed in a therapeutic tool to control neural dysfunction by slowing or even halting neurodegeneration mediated by ion-channel hyperactivity.

Novel Kunitz-like Peptides Discovered in the Zoanthid Palythoa caribaeorum through Transcriptome Sequencing.

Palythoa caribaeorum (class Anthozoa) is a zoanthid that together jellyfishes, hydra, and sea anemones, which are venomous and predatory, belongs to the Phyllum Cnidaria. The distinguished feature in these marine animals is the cnidocytes in the body tissues, responsible for toxin production and injection that are used majorly for prey capture and defense. With exception for other anthozoans, the toxin cocktails of zoanthids have been scarcely studied and are poorly known. Here, on the basis of the analysis of P. caribaeorum transcriptome, numerous predicted venom-featured polypeptides were identified including allergens, neurotoxins, membrane-active, and Kunitz-like peptides (PcKuz). The three predicted PcKuz isotoxins (1-3) were selected for functional studies. Through computational processing comprising structural phylogenetic analysis, molecular docking, and dynamics simulation, PcKuz3 was shown to be a potential voltage gated potassium-channel inhibitor. PcKuz3 fitted well as new functional Kunitz-type toxins with strong antilocomotor activity as in vivo assessed in zebrafish larvae, with weak inhibitory effect toward proteases, as evaluated in vitro. Notably, PcKuz3 can suppress, at low concentration, the 6-OHDA-induced neurotoxicity on the locomotive behavior of zebrafish, which indicated PcKuz3 may have a neuroprotective effect. Taken together, PcKuz3 figures as a novel neurotoxin structure, which differs from known homologous peptides expressed in sea anemone. Moreover, the novel PcKuz3 provides an insightful hint for biodrug development for prospective neurodegenerative disease treatment.

LINX® magnetic esophageal sphincter augmentation versus Nissen fundoplication for gastroesophageal reflux disease: a systematic review and meta-analysis.

BACKGROUND: The LINX® magnetic sphincter augmentation system (MSA) is a surgical technique with short-term evidence demonstrating efficacy in the treatment of medically refractory or chronic gastroesophageal reflux disease (GERD). Currently, the Nissen fundoplication is the gold-standard surgical treatment for GERD. We are the first to systematically review the literature and perform a meta-analysis comparing MSA to the Nissen fundoplication. METHODS: A comprehensive search of electronic databases (e.g., MEDLINE, EMBASE, SCOPUS, Web of Science and the Cochrane Library) using search terms "Gastroesophageal reflux or heartburn" and "LINX or endoluminal or magnetic" and "fundoplication or Nissen" was completed. All randomized controlled trials, non-randomized comparison study and case series with greater than 5 patients were included. Five hundred and forty-seven titles were identified through primary search, and 197 titles or abstracts were screened after removing duplicates. Meta-analysis was performed on postoperative quality of life outcomes, procedural efficacy and patient procedural satisfaction. RESULTS: Three primary studies identified a total of 688 patients, of whom 273 and 415 underwent Nissen fundoplication and MSA, respectively. MSA was statistically superior to LNF in preserving patient's ability to belch (95.2 vs 65.9%, p < 0.00001) and ability to emesis (93.5 vs 49.5%, p < 0.0001). There was no statistically significant difference between MSA and LNF in gas/bloating (26.7 vs 53.4%, p = 0.06), postoperative dysphagia (33.9 vs 47.1%, p = 0.43) and proton pump inhibitor (PPI) elimination (81.4 vs 81.5%, p = 0.68). CONCLUSION: Magnetic sphincter augmentation appears to be an effective treatment for GERD with short-term outcomes comparable to the more technically challenging and time-consuming Nissen fundoplication. Long-term comparative outcome data past 1 year are needed in order to further understand the efficacy of magnetic sphincter augmentation.

Enabling N-to-C Ser/Thr Ligation for Convergent Protein Synthesis via Combining Chemical Ligation Approaches.

In this article, Ser/Thr ligation(on/off) has been realized to enable N-to-C successive peptide ligations using a salicylaldehyde semicarbazone (SAL(off)) group by in situ activation with pyruvic acid of the peptide SAL(off) ester into the peptide salicylaldehyde (SAL(on)) ester. In addition, a peptide with a C-terminal thioester and N-terminal Ser or Thr as the middle peptide segment can undergo one-pot Ser/Thr ligation and native chemical ligation in the N-to-C direction. The utility of this combined ligation strategy in the N-to-C direction has been showcased through the convergent assembly of a human cytokine protein sequence, GlcNAcylated interleukin-25.

Peptide 2-formylthiophenol esters do not proceed through a Ser/Thr ligation pathway, but participate in a peptide aminolysis to enable peptide condensation and cyclization.

Peptide thiol salicylaldehyde (SAL) esters unexpectedly do not follow a Ser/Thr ligation pathway to react with peptides containing N-terminal Ser/Thr, but proceed towards a peptide aminolysis in DMSO. The reaction takes place even at a low substrate concentration (1 mM). The method has been successfully used to synthesize several natural cyclic peptides, with a high ratio of monocyclic to dimeric products.