FvemiR160-FveARF18A-FveAP1/FveFUL module regulates flowering time in woodland strawberry.

Flowering is an indicator of plant transformation from vegetative to reproductive growth. miR160 has been shown to have a significant effect on the growth and development of fruits, leaves, and roots of plants or their stress response to environment, but the participation of miR160 in regulating flowering time in plants is unclear. In this study, we found that two FvemiR160s (FvemiR160a/FvemiR160b) mature sequences in strawberry (Fragaria vesca) were consistent. It was displayed that the miR160 mature sequence is highly conserved in various species, and the miR160 mature sequence formed by the 5' arm of the MIR160 precursor was more conserved. Three FveARFs in woodland strawberry were negatively regulated by FvemiR160a, among which FveARF18A was the most significant. Phylogenetic analysis indicated that FvemiR160 is closely related to apple (Malus domestica), grape (Vitis vinifera), and Arabidopsis thaliana, while FveARF18A is closely related to RcARF18. Subsequently, we demonstrated that FvemiR160a can target cutting FveARF18A to negatively regulate its expression by RLM-5' RACE, cleavage site mutation, and GFP fluorescence assay. Moreover, we observed that FveMIR160a overexpressed plants have advanced flowering, while mFveARF18A overexpressed plants have delayed flowering. We also verified that FveARF18A negatively regulates the expression of FveAP1 and FveFUL by binding their promoters by yeast one-hybrid, LUC, and GUS assay, and FveAP1 and FveFUL transgenic Arabidopsis showed early flowering phenotype. In addition, the expression level of FvemiR160a was decreased obviously while that of FveARF18A was increased obviously by MeJA, GA and IAA. In conclusion, our study reveals the important role of the FvemiR160-FveARF18A-FveAP1/FveFUL module in the flowering process of woodland strawberry and provides a new pathway for studying flowering.

Antifouling polymers for nanomedicine and surfaces: recent advances.

Antifouling polymers are materials that can resist nonspecific interactions with cells, proteins, and other biomolecules. Typically, they are hydrophilic polymers with polar or charged moieties that are capable of strong nonbonding interactions with water molecules. This propensity to bind water generates a surface hydration layer that reduces nonspecific interactions with other molecules and is paramount to the antifouling behavior. This property is especially useful for nanoscale applications such as nanomedicine and surface modifications at the molecular level. In nanomedicine, antifouling polymers such as poly(ethylene glycol) and its alternatives play a key role in shielding drug molecules and therapeutic proteins/genes from the immune system within nanoassemblies, thereby enabling effective delivery to target tissues. For coatings, antifouling polymers help to prevent adhesion of cells and molecules to surfaces and are thus valued in marine and biomedical device applications. In this Review, we survey recent advances in antifouling polymers in the context of nanomedicine and coatings, while shining the spotlight on the major polymer classes such as PEG, polyzwitterions, poly(oxazoline)s, and other nonionic hydrophilic polymers.

Design of competition nanoreactor with shell-isolated colloidal plasmonic nanomaterials for quantitative sensor platform.

Shell-isolated colloid plasmonic nanomaterials-based nanoreactor is a well-established platform widely applied in catalyst or Surface Enhanced Raman Scattering (SERS) sensors. The potentials versatility of nanoreactor platform is mainly implemented by the well-defined and tailorable structure of colloid plasmonic nanomaterials. Currently, a competitive conjugative-mediated nanoreactor is introduced to determine glucose with SERS. Glucose-conjugating nanoreactor, as convertors of the sensors, are constructed by coordinated deposition colloidal gold nanoparticles with sodium nitroprusside framework (Au@SNF) and covalently bonded 4-mercaptopyridine (4-Mpy) with self-assembly strategy. The nanoreactor contained the signal-amplifier Au@SNF NPs, conjugative-mediated signal receiver 4-Mpy, and signal internal standard molecular CN-. In addition to well-defined morphology and functionality, conjugative-mediated and internal standards method are also employed to benefit the nanoreactor. The two-parameter strategy significantly improves the signal indication and correction. Using this proposed platform, the competitive-mediated nanoreactor provides a quantitative SERS detection of glucose, and extends the applicability of SERS in more complicated and reproducibility analysis. Meanwhile, the nanoreactor based sensors also exhibited better properties to detect glucose in various food samples and bio-samples which provided strongly appliance for glucose sensors.

Visible Light Degradable Acridine-Containing Polyurethanes in an Aqueous Environment.

Light degradable polymers hold significant promise in a wide range of applications including the fabrication of optically recyclable materials, responsive coatings and adhesives, and controlled drug delivery. Here, we report the synthesis of polyurethanes that can be degraded under irradiation of visible light (≤450 nm) from commercial LED (3-15 W) light sources. The photolysis occurs in an aqueous environment via photocleavage of an acridine moiety incorporated within the backbone of the polymer chains. Analysis of the quantum yield as a function of wavelength reveals highly efficient photoreactivity at up to 440 nm activation, which is red-shifted compared to the UV-vis absorbance of the chromophore. The potential of our chemical system in biomaterials is demonstrated by the fabrication of an in situ forming hydrogel that can be degraded by visible light.

Guanidinium-Perfunctionalized Polyhedral Oligomeric Silsesquioxanes as Highly Potent Antimicrobials against Planktonic Microbes, Biofilms, and Coronavirus.

Supramolecules have been drawing increasing attention recently in addressing healthcare challenges caused by infectious pathogens. We herein report a novel class of guanidinium-perfunctionalized polyhedral oligomeric silsesquioxane (Gua-POSS) supramolecules with highly potent antimicrobial activities. The modular structure of Gua-POSS Tm-Cn consists of an inorganic T10 or T8 core (m = 10 or 8), flexible linear linkers of varying lengths (n = 1 or 3), and peripherally aligned cationic guanidinium groups as the membrane-binding units. Such Gua-POSS supramolecules with spherically arrayed guanidinium cations display high antimicrobial potency against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, as well as fungus (Candida albicans), with the best showing excellently low minimal inhibitory concentrations (MICs) of 1.7-6.8 µM in media, yet with negligible hemolytic activity and low in vitro cytotoxicity to mammalian cells. More significantly, they can inhibit biofilm formation at around their MICs and near-completely break down preestablished difficult-to-break biofilms at 250 µg mL-1 (∼50 µM). Their strong antiviral efficacy was also experimentally demonstrated against the enveloped murine hepatitis coronavirus as a surrogate of the SARS-CoV species. Overall, this study provides a new design approach to novel classes of sphere-shaped organic-inorganic hybrid supramolecular materials, especially for potent antimicrobial, anti-biofilm, and antiviral applications.

Cu(I)/Cu(II) Creutz-Taube Mixed-Valence 2D Coordination Polymers.

Graphene-like 2D coordination polymers (GCPs) have been of central research interest in recent decades with significant impact in many fields. According to classical coordination chemistry, Cu(II) can adopt the dsp2 hybridization to form square planar coordination geometry, but not Cu(I); this is why so far, there has been few 2D layered structures synthesized from Cu(I) precursors. Herein a pair of isostructural GCPs synthesized by the coordination of benzenehexathiol (BHT) ligands with Cu(I) and Cu(II) ions, respectively, is reported. Spectroscopic characterizations indicate that Cu(I) and Cu(II) coexist with a near 1:1 ratio in both GCPs but remain indistinguishable with a fractional oxidation state of +1.5 on average, making these two GCPs a unique pair of Creutz-Taube mixed-valence 2D structures. Based on density functional theory calculations, an intramolecular pseudo-redox mechanism is further uncovered whereby the radicals on BHT ligands can oxidize Cu(I) or reduce Cu(II) ions upon coordination, thus producing isostructures with distinct electron configurations. For the first time, it is demonstrated that using Cu(I) or Cu(II), one can achieve 2D isostructures, indicating an unusual fact that a neutral periodic structure can host a different number of total electrons as ground states, which may open a new chapter for 2D materials.

Neutral Antiaromatic Bis(1,2-dithiolene)-Chelated Nickel Complexes Bearing Multiradical Characters.

Metal-organic complexes with radical characteristics are unique species attracting immense attention in recent years due to their peculiar properties and promising applicability in a wide variety of innovative research fields. However, the reported complexes typically do not exceed diradicality. This study systematically investigates a series of square planar neutral Ni-bis(1,2-dithiolene) and Ni-bis(1,2-dioxolene) complexes with linear, branched, and macrocyclic configurations via ab initio calculations. The linear Ni-complexes display strong singlet diradical characters, while their branched counterparts can also exhibit moderate singlet multiradical characters. Importantly, the macrocyclic Ni-complexes can possess extremely strong singlet multiradical characters up to dodeca-radicality along with their global antiaromaticity and hence strong induced ring current in the presence of an external magnetic field, ascribed to the localization of unpaired α and ß electrons residing in the highest few molecular orbitals at different molecular sites, minimizing their coupling and annihilation. Our work represents the first indication in the rational design of novel multiradical neutral antiaromatic macrocyclic complexes for potential applications in molecular machines and electronic devices.

Preparation and application of silver/chitosan-sepiolite materials with antimicrobial activities and low cytotoxicity.

Antimicrobial materials can prevent microbial infection and affect the beauty and structure of interior walls. Herein, a hybrid material silver/chitosan-sepiolite (Ag/5CTs-Sep) with antimicrobial activities was prepared via impregnation. Its antimicrobial properties were investigated via the disk diffusion method. Results showed that the width of inhibition zone of Ag/5CTs-Sep against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Aspergillus niger reached 58.15, 32.95 and 35.18 mm, respectively. The Sep was a suitable carrier for increasing thermal stability and antimicrobial durability, and chitosan improved the dispersion of silver to enhance antimicrobial activities. In addition, characterization indicated that the modification of Sep by CTs can promote the formation of lattice oxygen in Ag/5CTs-Sep, which can induce a high reactive oxygen species (ROS) content, causing the death of microbials. The antifungal mechanism revealed that the death of Aspergillus niger was due to Ag/5CTs-Sep that induced the production of high ROS level and damaged cell membrane. Moreover, Ag/5CTs-Sep possessed low cytotoxicity, and an applied test of the water-based coatings showed that the addition of Ag/5CTs-Sep could both effectively inhibit microorganisms and meet the performance standards for water-based coatings. This work may provide new guidance for the design and application of antibacterial materials.

Comparison of high-dose dual therapy with bismuth-containing quadruple therapy in Helicobacter pylori-infected treatment-naive patients: An open-label, multicenter, randomized controlled trial.

OBJECTIVE: Bismuth-containing quadruple therapy for Helicobacter pylori (H. pylori) eradication has a relatively high rate of side effects and high cost, thus the option of a high-dose dual therapy with a high eradication rate and fewer adverse events is a consideration. However, studies of dual therapy are still scarce and are mostly single-center studies with limited generalizability. Large-scale, multicenter studies are required. Our study investigated and compared the effectiveness, adverse events, patient compliance, and costs of high-dose dual therapy with those of bismuth-containing quadruple therapy in H. pylori-infected treatment-naive patients in a prospective, multicenter, open-label, randomized controlled trial. METHOD: Treatment-naive patients infected with H. pylori were randomly assigned to receive high-dose dual therapy (esomeprazole 20 mg 4 times daily and amoxicillin 1000 mg 3 times daily, for 14 days) or bismuth-containing quadruple therapy (esomeprazole 20 mg, amoxicillin 1000 mg, clarithromycin 500 mg, and bismuth potassium citrate 220 mg, all twice daily for 14 days). The effectiveness, adverse events, patient compliance, and costs of both groups were compared. RESULTS: A total of 700 patients were enrolled. The high-dose dual therapy group (N = 350) achieved eradication rates of 89.4% (intention-to-treat), 90.4% (modified intention-to-treat), and 90.6% (per-protocol), which were similar to rates in the bismuth-containing quadruple therapy group (N = 350), 84.6%, 88.0%, and 88.2%, respectively (p > 0.05). The high-dose dual therapy group had a lower rate of adverse events (12.9% vs. 28.1%, p < 0.001) and lower costs (¥590.2 vs. ¥723.22) compared with the quadruple therapy group, respectively. The compliance of both groups was satisfactory (97.7% high-dose dual vs. 96.8% quadruple, p > 0.05). CONCLUSION: High-dose dual therapy for H. pylori eradication had similar efficacy and compliance, fewer adverse events, and lower costs than bismuth-containing quadruple therapy for treatment-naive patients.

Neoadjuvant Chemotherapy in Early Triple-Negative Breast Cancer: A Pairwise and Network Meta-Analysis of Pathological Complete Response.

We performed a pairwise and network meta-analysis to compare pathological complete response (pCR) among neoadjuvant chemotherapy in patients with triple-negative breast cancer. We searched PubMed for randomized clinical trials between January 1, 2000 and December 1, 2020. Abstracts from meetings were also searched. A frequentist random-effect model was applied to compare pCR and toxicities. The P-score was used to rank treatment effects. Nineteen trials with 16 treatments and 7794 patients were included. On the basis of SoC, the addition of carboplatin (OR = 1.82, 95% CI, 1.24 to 2.68, P < .01) and the addition of checkpoint inhibitors (OR = 1.69, 95% CI, 1.23 to 2.32, P < .01) increased pCR in pairwise meta-analysis; compared with paclitaxel, nab-paclitaxel did not improve pCR rates (OR = 1.81, 95% CI, .80 to 4.12, P = .16). The anthracycline-sparing regimen led to similar pCR compared with the anthracycline-containing regimen (OR = 1.50, 95% CI, .82 to 2.76, P = .19). In network meta-analysis, the addition of carboplatin plus a PD-1 inhibitor (pembrolizumab), carboplatin plus bevacizumab, and carboplatin plus veliparib ranked as the top three treatments for achieving pCR, with corresponding P-scores of .91, .84, and .72, respectively. Among patients with homologous recombination deficiency, the addition of carboplatin (OR = 1.31, 95% CI, .69 to 2.50, P = .41) or carboplatin plus PARP inhibitors (OR = 1.19, 95% CI, .58 to 2.47, P = .63) did not increase pCR. For triple-negative breast cancer, combining carboplatin with taxane-anthracycline-containing neoadjuvant chemotherapy could be the standard of care, and the combination containing checkpoint inhibitor is promising. However, their role in long-term oncologic outcome remains to be determined.

Titanium compounds containing naturally occurring dye molecules.

A range of titanium compounds containing the naturally occurring dyes quinizarin (QH2) and alizarin (AH2) was synthesized and structurally characterized in the solid state. Among these is the first examples of a discrete metallocyclic arrangement formed exclusively using quinizarin ligands and the first examples of lanthanide containing titanium compounds of the alizarin family of ligands.

Development and validation of a radiomics-based model to predict local progression-free survival after chemo-radiotherapy in patients with esophageal squamous cell cancer.

PURPOSE: To develop a nomogram model for predicting local progress-free survival (LPFS) in esophageal squamous cell carcinoma (ESCC) patients treated with concurrent chemo-radiotherapy (CCRT). METHODS: We collected the clinical data of ESCC patients treated with CCRT in our hospital. Eligible patients were randomly divided into training cohort and validation cohort. The least absolute shrinkage and selection operator (LASSO) with COX regression was performed to select optimal radiomic features to calculate Rad-score for predicting LPFS in the training cohort. The univariate and multivariate analyses were performed to identify the predictive clinical factors for developing a nomogram model. The C-index was used to assess the performance of the predictive model and calibration curve was used to evaluate the accuracy. RESULTS: A total of 221 ESCC patients were included in our study, with 155 patients in training cohort and 66 patients in validation cohort. Seventeen radiomic features were selected by LASSO COX regression analysis to calculate Rad-score for predicting LPFS. The patients with a Rad-score ≥ 0.1411 had high risk of local recurrence, and those with a Rad-score < 0.1411 had low risk of local recurrence. Multivariate analysis showed that N stage, CR status and Rad-score were independent predictive factors for LPFS. A nomogram model was built based on the result of multivariate analysis. The C-index of the nomogram was 0.745 (95% CI 0.7700-0.790) in training cohort and 0.723(95% CI 0.654-0.791) in validation cohort. The 3-year LPFS rate predicted by the nomogram model was highly consistent with the actual 3-year LPFS rate both in the training cohort and the validation cohort. CONCLUSION: We developed and validated a prediction model based on radiomic features and clinical factors, which can be used to predict LPFS of patients after CCRT. This model is conducive to identifying the patients with ESCC benefited more from CCRT.

Auxin-induced AUXIN RESPONSE FACTOR4 activates APETALA1 and FRUITFULL to promote flowering in woodland strawberry.

Flowering time is known to be regulated by numerous pathways, such as the autonomous, gibberellin, aging, photoperiod-mediated, and vernalization pathways. These regulatory mechanisms involve both environmental triggers and endogenous hormonal cues. Additional flowering control mechanisms mediated by other phytohormones, such as auxin, are less well understood. We found that in cultivated strawberry (Fragaria × ananassa), the expression of auxin response factor4 (FaARF4) was higher in the flowering stage than in the vegetative stage. Overexpression of FaARF4 in Arabidopsis thaliana and woodland strawberry (Fragaria vesca) resulted in transgenic plants flowering earlier than control plants. In addition, FveARF4-silenced strawberry plants showed delayed flowering compared to control plants, indicating that FaARF4 and FveARF4 function similarly in regulating flowering. Further studies showed that ARF4 can bind to the promoters of the floral meristem identity genes APETALA1 (AP1) and FRUITFULL (FUL), inducing their expression and, consequently, flowering in woodland strawberry. Our studies reveal an auxin-mediated flowering pathway in strawberry involving the induction of ARF4 expression.

A nomogram based on pretreatment CT radiomics features for predicting complete response to chemoradiotherapy in patients with esophageal squamous cell cancer.

PURPOSE: To develop and validate a nomogram model to predict complete response (CR) after concurrent chemoradiotherapy (CCRT) in esophageal squamous cell carcinoma (ESCC) patients using pretreatment CT radiomic features. METHODS: Data of patients diagnosed as ESCC and treated with CCRT in Shantou Central Hospital during the period from January 2013 to December 2015 were retrospectively collected. Eligible patients were included in this study and randomize divided into a training set and a validation set after successive screening. The least absolute shrinkage and selection operator (LASSO) with logistic regression to select radiomics features calculating Rad-score in the training set. The logistic regression analysis was performed to identify the predictive clinical factors for developing a nomogram model. The area under the receiver operating characteristic curves (AUC) was used to assess the performance of the predictive nomogram model and decision curve was used to analyze the impact of the nomogram model on clinical treatment decisions. RESULTS: A total of 226 patients were included and randomly divided into two groups, 160 patients in training set and 66 patients in validation set. After LASSO analysis, seven radiomics features were screened out to develop a radiomics signature Rad-score. The AUC of Rad-score was 0.812 (95% CI 0.742-0.869, p < 0.001) in the training set and 0.744 (95% CI 0.632-0.851, p = 0.003) in the validation set. Multivariate analysis showed that Rad-score and clinical staging were independent predictors of CR status, with p values of 0.035 and 0.023, respectively. A nomogram model incorporating Rad-socre and clinical staging was developed and validated, with an AUC of 0.844 (95% CI 0.779-0.897) in the training set and 0.807 (95% CI 0.691-0.894) in the validation set. Delong test showed that the nomogram model was significantly superior to the clinical staging, with p < 0.001 in the training set and p = 0.026 in the validation set. The decision curve showed that the nomogram model was superior to the clinical staging when the risk threshold was greater than 25%. CONCLUSION: We developed and validated a nomogram model for predicting CR status of ESCC patients after CCRT. The nomogram model was combined radiomics signature Rad-score and clinical staging. This model provided us with an economical and simple method for evaluating the response of chemoradiotherapy for patients with ESCC.

Preparation of organic-inorganic chitosan@silver/sepiolite composites with high synergistic antibacterial activity and stability.

Organic-inorganic antibacterial materials chitosan@silver/sepiolite (CTs@Ag/Sep) was prepared by grafting organometallic chelate of chitosan and silver on sepiolite. The prepared samples were characterized, and their antibacterial properties were detected. The carrier sepiolite was beneficial for the thermal stability of the composite material. The utilization of silver was enhanced and its amount of usage could be obviously reduced by introduction of nontoxic chitosan which was benefical for the formation of highly dispersed silver nanoparticles on the CTs@Ag/Sep by the interaction between the silver ion and the plentiful amino and hydroxyl groups on the chitosan, thus improved the antibacterial activities and stability. The average width of the inhibition zone of CTs@Ag/Sep against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Aspergillus niger were 51.8, 31.8, and 44.7 mm, respectively. The cytotoxicity of CTs@Ag/Sep was further evaluated with A549 cells, and the results indicated that it exhibited low cytotoxicity to eukaryotic cells.

Clinicopathological association and prognostic value of long non-coding RNA CASC9 in patients with cancer: A meta-analysis.

Several studies have reported a prognostic role of the long non-coding RNA (lncRNA) cancer susceptibility candidate 9 (CASC9) in various cancer types, but its clinical significance has remained inconclusive. The aim of the present meta-analysis was to evaluate the impact of CASC9 expression on the prognosis and clinicopathological features of patients with cancer patients. The PubMed, Embase, Cochrane Library and Web of Science databases were searched for relevant literature and eight studies, including 565 patients with cancer, were selected. The quality of these studies was appraised with the Newcastle-Ottawa Scale (NOS) and the association between CASC9 expression and prognosis or clinicopathological features was analyzed. Patients with high expression levels of CASC9 in their tumor tissues had a lower overall survival rate compared with those in the low CASC9 expression group (hazard ratio=2.25, 95% CI: 1.60-3.17, P<0.001). Furthermore, elevated CASC9 expression was significantly associated with deeper tumor invasion [odds ratio (OR)=2.66, 95% CI: 1.72-4.14, P<0.001], poor tumor differentiation (OR=2.44, 95% CI: 1.24-4.78, P=0.009), lymph node metastasis (OR=3.42, 95% CI: 1.98-5.92, P<0.001) and advanced clinical stage (OR=3.21, 95% CI: 2.21-4.66, P<0.001). In conclusion, CASC9 is a promising biomarker for predicting the prognosis of cancer patients and should be validated in the clinic.

Development and validation of a genomic mutation signature to predict response to PD-1 inhibitors in non-squamous NSCLC: a multicohort study

BACKGROUND: Genetic variations of some driver genes in non-small cell lung cancer (NSCLC) had shown potential impact on immune microenvironment and associated with response or resistance to programmed cell death protein 1 (PD-1) blockade immunotherapy. We therefore undertook an exploratory analysis to develop a genomic mutation signature (GMS) and predict the response to anti-PD-(L)1 therapy. METHODS: In this multicohort analysis, 316 patients with non-squamous NSCLC treated with anti-PD-(L)1 from three independent cohorts were included in our study. Tumor samples from the patients were molecularly profiled by MSK-IMPACT or whole exome sequencing. We developed a risk model named GMS based on the MSK training cohort (n=123). The predictive model was first validated in the separate internal MSK cohort (n=82) and then validated in an external cohort containing 111 patients from previously published clinical trials. RESULTS: A GMS risk model consisting of eight genes (TP53, KRAS, STK11, EGFR, PTPRD, KMT2C, SMAD4, and HGF) was generated to classify patients into high and low GMS groups in the training cohort. Patients with high GMS in the training cohort had longer progression-free survival (hazard ratio (HR) 0.41, 0.28-0.61, p<0.0001) and overall survival (HR 0.53, 0.32-0.89, p=0.0275) compared with low GMS. We noted equivalent findings in the internal validation cohort and in the external validation cohort. The GMS was demonstrated as an independent predictive factor for anti-PD-(L)1 therapy comparing with tumor mutational burden. Meanwhile, GMS showed undifferentiated predictive value in patients with different clinicopathological features. Notably, both GMS and PD-L1 were independent predictors and demonstrated poorly correlated; inclusion of PD-L1 with GMS further improved the predictive capacity for PD-1 blockade immunotherapy. CONCLUSIONS: Our study highlights the potential predictive value of GMS for immunotherapeutic benefit in non-squamous NSCLC. Besides, the combination of GMS and PD-L1 may serve as an optimal partner in guiding treatment decisions for anti-PD-(L)1 based therapy.

[Effect of L-cysteine on colonic motility and the underlying mechanism].

The purpose of the present study is to investigate the effect of L-cysteine on colonic motility and the underlying mechanism. Immunohistochemical staining and Western blot were used to detect the localization of the H2S-generating enzymes cystathionine-ß-synthase (CBS) and cystathionine-γ-lyase (CSE). Organ bath system was used to observe the muscle contractile activities. Whole-cell patch-clamp technique was applied to record ionic channels currents in colonic smooth muscle cells. The results showed that both CBS and CSE were localized in mucosa, longitudinal and circular muscle and enteric neurons. L-cysteine had a dual effect on colonic contraction, and the excitatory effect was blocked by pretreatment with CBS inhibitor aminooxyacetate acid (AOAA) and CSE inhibitor propargylglycine (PAG); L-cysteine concentration-dependently inhibited L-type calcium channel current (ICa,L) without changing the characteristic of L-type calcium channel (P < 0.01); In contrast, the exogenous H2S donor NaHS increased ICa,L at concentration of 100 µmol/L, but inhibited ICa,L and modified the channel characteristics at concentration of 300 µmol/L (P < 0.05); Furthermore, L-cysteine had no effect on large conductance calcium channel current (IBKCa), but NaHS significantly inhibited IBKCa (P < 0.05). These results suggest that L-cysteine has a potential dual effect on colonic smooth muscle and the inhibitory effect might be directly mediated by L-type calcium channel while the excitatory effect might be mediated by endogenous H2S.