Antibody immune responses and causal relationships in four immune skin diseases: Evidence from Mendelian randomization and Bayesian Weighting (Antibody Responses in Skin Diseases: MR & Bayesian).

BACKGROUND: Recent studies increasingly suggest that microbial infections and the immune responses they elicit play significant roles in the pathogenesis of chronic inflammatory skin diseases. This study uses Mendelian randomization (MR) and Bayesian weighted Mendelian randomization (BWMR) to explore the causal relationships between immune antibody responses and four common skin diseases: psoriasis, atopic dermatitis (AD), rosacea, and vitiligo. METHODS: We utilized summary statistics from genome-wide association studies (GWAS) for antibody responses to 13 infectious pathogens and four skin diseases. Single nucleotide polymorphisms (SNPs) were selected as instrumental variables (IVs) to assess causal relationships using multiple MR methods, including inverse variance weighted (IVW), MR Egger, and weighted median. BWMR was also employed to confirm findings and address potential pleiotropy. RESULTS: The IVW analysis identified significant associations between specific antibody responses and the skin diseases studied. Key findings include protective associations of anti-Epstein-Barr virus (EBV) IgG seropositivity and Helicobacter pylori UREA antibody levels with psoriasis and AD. anti-chlamydia trachomatis IgG seropositivity, anti-polyomavirus 2 IgG seropositivity, and varicella zoster virus glycoprotein E and I antibody levels were negatively associated with rosacea, while EBV Elevated levels of the early antigen (EA-D) antibody levels and HHV-6 IE1B antibody levels were positively associated with rosacea. H. pylori Catalase antibody levels were protectively associated with vitiligo, whereas anti-herpes simplex virus 2 (HSV-2) IgG seropositivity was positively associated with vitiligo. The BWMR analysis confirmed these associations. CONCLUSION: This study underscores the significant role of H. pylori and other pathogens in these skin diseases, suggesting both protective and exacerbating effects depending on the specific condition. Understanding these pathogen-immune interactions can lead to the development of more effective, personalized treatments and preventative strategies, ultimately improving patient outcomes and quality of life.

Skin microbiome and causal relationships in three dermatological diseases: Evidence from Mendelian randomization and Bayesian weighting.

BACKGROUND: Atopic dermatitis (AD), psoriasis (PSO), rosacea, and other related immune skin diseases are affected by multiple complex factors such as genetic and microbial components. This research investigates the causal relationships between specific skin microbiota and these diseases by using Mendelian randomization (MR), and Bayesian weighted Mendelian randomization (BWMR). METHODS: We utilized genome-wide association study (GWAS) data to analyze the associations between various skin bacteria and three dermatological diseases. Single nucleotide polymorphisms (SNPs) served as instrumental variables (IVs) in MR methods, including inverse variance weighted (IVW), and MR Egger. BWMR was employed to validate results and address pleiotropy. RESULTS: The IVW analysis identified significant associations between specific skin microbiota and dermatological diseases. ASV006_Dry, ASV076_Dry, and Haemophilus_Dry were significantly positively associated with AD, whereas Kocuria_Dry was negatively associated. In PSO, ASV005_Dry was negatively associated, whereas ASV004_Dry, Rothia_Dry, and Streptococcus_Moist showed positive associations. For rosacea, ASV023_Dry was significantly positively associated, while ASV016_Moist, Finegoldia_Dry, and Rhodobacteraceae_Moist were significantly negatively associated. These results were corroborated by BWMR analysis. CONCLUSION: Bacterial species such as Finegoldia, Rothia, and Streptococcus play crucial roles in the pathogenesis of AD, PSO, and rosacea. Understanding these microbial interactions can aid in developing targeted treatments and preventive strategies, enhancing patient outcomes and quality of life.

Facile synthesis of ZnO nanoparticles by Actinidia deliciosa fruit peel extract: Bactericidal, anticancer and detoxification properties.

Synthesis of nanoparticles by eco-friendly method pulled an extensive concern worldwide due its biocompatibility and wide range of applications as catalysts, microbicidal agents, cancer treatment, sensors etc. Though different chemical methods available for preparation of ZnO nanoparticles, synthesis by utilizing plant material is an excellent substitute and green method as well. The present study describes preparation of ZnO nanoparticles by low-cost green synthetic way using Actinidia deliciosa (kiwi) fruit peel extract and its excellent biological and catalytic properties. The synthesized nanoparticles were well characterized by UV visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Energy-dispersive X-ray spectroscopy (EDAX). The bactericidal activity of the ZnO nanoparticles was determined by using Staphylococcus aureus (S. aureus), while mechanism of cell death was studied by SEM images. Superior anticancer activity was also observed in inhibiting the colon cancer cells (HCT116) by the ZnO nanoparticles. In addition, ZnO nanoparticles showed efficient photocatalytic activity towards degradation of p-bromophenol, about 96.3% within 120 min. Furthermore, phytotoxicity of the intermediate products was analyzed using Vigna radiata (V. radiata) as a model plant. About 8.0% of germination index (GI) was observed in pure p-BP while it increased to 82.3%, and exhibited that the detoxification of p-BP was attained after 120 min of degradation. Thus, the present study demonstrates ZnO nanoparticles prepared from simple, rapid, inexpensive, eco-friendly and efficient green method gives alternative root for biomedicine and wastewater treatment technologies.

The effect of Jiedu Huoxue decoction on rat model of experimental nonbacterial prostatitis via regulation of miRNAs.

CONTEXT: The underlying mechanisms of Jiedu Huoxue decoction (JDHXD) in treating chronic prostatitis have not been fully explored. OBJECTIVE: This study investigates the miRNAs as potential biomarkers and the effect of JDHXD on the rat model of experimental nonbacterial prostatitis. MATERIALS AND METHODS: Fifty-four Sprague-Dawley male rats were randomly divided into normal control, model, JDHXD low dose (0.5 g/kg/day), medium dose (1 g/kg/day), high dose (2 g/kg/day) and western medicine (cernilton 0.094 g/kg/day) groups, and intragastrically administered once daily for 30 days. The control and model (upon successful establishment) groups received distilled water. Differential expression of miRNAs was analysed with high-throughput miRNA sequencing and validated with qRT-PCR and Northern blot. Prediction of specific target genes and functional enrichment analysis were performed with bioinformatics. RESULTS: LD50 test showed no sign of toxicity with maximum feasible dose 4 g/kg JDHXD. Compared with control, 495 miRNAs showed expression changes in CAP/CPPS rats, of which 211 were significantly different and 37 were prostatic-related. There were 181 differentially expressed miRNAs between the model and high dose JDHXD groups, of which 23 were identical with the control and model groups. Compared with control, miR-146a, miR-423 and miR-205 expression increased significantly in the model group, decreased dose-dependently in the JDHXD groups (p < 0.05), and vice-versa for miR-96 (p < 0.05). The effect of low dose JDHXD was comparable to cernilton (p > 0.05). DISCUSSION AND CONCLUSIONS: Future studies may explore the contributions of the active components in JDHXD. The study design is generalisable. The effect can be repeatedly verified in clinical trials.

Jiedu Huoxue decoction improves inflammation in rat type III prostatitis: The importance of the NF-κB signalling pathway.

This study aimed to investigate the mechanism of Jiedu Huoxue decoction (JDHXD) in type III prostatitis based on the NF-κB signalling pathway. Twenty-six Sprague-Dawley male rats were divided into blank control, model, positive (Prostate Plus), low-dose JDHXD, medium-dose JDHXD and high-dose JDHXD groups. Type III prostatitis rat model was established and confirmed with HE staining. NF-кB P50 and NF-κB P65 expression was detected with immunohistochemistry. NF-κB mRNA expression was detected with qRT-PCR. Protein expression of NF-κB and its inhibitor Iκ-Bα was detected with Western blot. Compared to the model group, a decrease in glandular hyperplasia and inflammation, and in NF-кB P50 and NF-κB P65 expression in the medium- and high-dose JDHXD groups was observed. NF-κB mRNA expression was significantly increased in the model group compared to control (p < 0.05), and significantly decreased in the JDHXD treatment groups compared to model group (p < 0.05). Protein expression of NF-κB was significantly increased in the model and low-dose JDHXD groups compared to control(p < 0.05), and significantly decreased in the medium- and high-dose JDHXD groups compared to model group (p < 0.05). Protein expression of Iκ-Bα was vice versa. JDHXD could be a potential treatment for type III prostatitis via its regulation of NF-κB and Iκ-Bα expression.

Impact of Lymphocyte Subsets on Chemotherapy Efficacy and Long-term Survival of Patients with Advanced Non-small-cell Lung Cancer.

Objective To analyze the impact of lymphocyte subsets on chemotherapy efficacy and long-term survival of patients with advanced non-small cell lung cancer(NSCLC).Methods Totally 125 NSCLC patients who had received first-line chemotherapy including paclitaxel and pemetrexed with/without platinum were enrolled in this study.Lymphocytes from peripheral blood were collected before and after two cycles of first-line chemotherapy.Flow cytometry was performed to determine the expressions of 21 fluorescence-labeled lymphocyte subsets.Based on the imaging findings,chemotherapy efficacy was evaluated,and impact of the lymphocyte subsets on progression-free survival(PFS)and overall survival(OS)were analyzed.Results The baseline peripheral lymphocyte subsets showed no significant difference among groups receiving different treatment protocols(all P>0.05).After 2 cycles of chemotherapy,the percentage of CD4+CD29+lymphocytes was(16.87±5.28)% in progressive disease group,which was significantly lower than those in complete remission+partial remission group [(22.42±7.88)%,P=0.013] and stable disease group [(21.88±6.81)%,P=0.009].The median PFS was 7.07 months and median OS was 23.00 months.Cox multivariable regression analysis showed that the percentages of HLA-DR+(HR:1.03,95%CI:1.01-1.05,P<0.001) and CD3+HLA-DR+lymphocytes (HR:1.05,95%CI:1.01-1.08,P<0.001)were positively correlated with OS.Conclusions The rise of CD4+CD29+T lymphocytes in patients after chemotherapy indicates good chemotherapy efficacy.Higher percentage of HLA-DR+and CD3+HLA-DR+lymphocytes in peripheral blood before chemotherapy predicts favorable prognosis.

Transarterial chemoembolization combined with sintilimab and lenvatinib for the treatment of unresectable hepatocellular carcinoma: a retrospective study.

BACKGROUND: The treatment of unresectable hepatocellular carcinoma (uHCC) challenging due to unfulfilled clinical requirements. OBJECTIVE: To evaluate the safety and efficacy of combining transarterial chemoembolization (TACE) with sintilimab and lenvatinib in the treatment of uHCC. METHODS: We retrospectively analyzed the data of patients with uHCC who were treated with a combination of TACE, sintilimab, and lenvatinib between May 2019 and December 2021 at the Chinese PLA General Hospital. Systemic treatment was started 1 week after TACE was performed. Sintilimab was administered intravenously at a dosage of 200 mg every three weeks, and lenvatinib was given orally at dosages of 8 mg or 12 mg daily, contingent upon the weight of the patients. The primary endpoint was the objective response rate (ORR) as per the mRECIST. Secondary endpoints were disease control rate (DCR), progression-free survival (PFS), overall survival (OS) and treatment-related adverse events (tr-AEs). RESULTS: A total of 32 patients were enrolled in the study. Among them, 9 patients were classified as Barcelona Clinic Liver Cancer-B (BCLC-B), 23 patients were classified as BCLC-C, 14 patients diagnosed with portal vein tumors, and 12 patients were diagnosed with extra hepatic metastases. The ORR and DCR were 75% and 90.6% respectively, with 4 patients exhibiting (12.5%) complete response, 20 patients exhibiting (62.5%) partial response, 5 patients exhibiting (15.6%) stable disease, and 3 patients exhibiting (9.4%) progressive disease. With a median follow-up time of 19.6 months, the median PFS was 9.9 months, and the median OS was 33.3 months. A total of 31 patients experienced different degrees of tr-AEs, of which 2 were grade 3 tr-AEs. CONCLUSION: The combination therapy of TACE, sintilimab, and lenvatinib demonstrates satisfactory efficacy in the treatment of uHCC with manageable tr-AEs.

Impact of soil surface properties on soil swelling of different soil layers in collapsing wall of Benggang.

Benggang is one of the most serious soil erosion problems in tropical and subtropical areas in southern China. Little work has been reported on the surface properties of soil colloidal particle and its influence on soil swelling of different soil layers in collapsing wall of Benggang. In this present work, the effects of sodium concentration on soil swelling, and the correlations between soil swelling rates and soil colloidal surface properties were comprehensively evaluated by carefully examining soil physicochemical properties and soil colloidal surface properties of red, sandy and detritus soil layers from a collapsing wall. Our results showed that the soil swelling rates of red, sandy and detritus soil layers all exponentially decreased with increasing initial water contents. The relationship between soil swelling rate and the thickness of shear plane showed an extremely significant negative correlation for red soil layer and no correlation for sandy and detritus soil layers. Moreover, the elevating sodium concentrations reduced the thickness of shear plane from 39.69 to 0.76 nm for red soil layer, followed from 22.56 to 0.79 nm for sandy soil layer and from 18.61 to 0.64 nm for detritus soil layer. These findings indicated that the soil particle interactions played a crucial role in the development and occurrence of Benggang. This work will be helpful in understanding the mechanisms of soil mass loss on the gully head and collapsing wall of Benggang.

The Single-Nucleotide Polymorphism of miR-27a rs895819 and the Expression of miR-27a in Helicobacter pylori-Related Diseases and the Correlation with the Traditional Chinese Medicine Syndrome.

Aims: The study aims to explore the effects of the single-nucleotide polymorphism of miR-27a and its expression in Helicobacter pylori (H. pylori)-related diseases and the relationship between gastric pathology and traditional Chinese medicine (TCM). Methods: Subjects were classified into six histopathological groups and five TCM syndrome groups. All specimens underwent H. pylori detection through rapid urease test and methylene blue staining. Histopathological characteristics were observed by hematoxylin-eosin. The expression of miR-27a and its genotype were, respectively, detected by Quantitative Real-Time PCR and direct sequencing. Results: H. pylori promoted the malignant evolution of gastric mucosa and were involved in the formation of TCM syndrome. In H. pylori-positive patients, the frequency of miR-27a CT genotype at the rs895819 locus and its expression in the gastric cancer group were higher than those in other pathological groups. TCM syndrome had a close relationship with histopathological changes, and patients with spleen-qi deficiency syndrome had a higher risk of gastric cancer than other syndromes, regardless of H. pylori infection. Conclusion: The C allele at miR-27a rs895819 locus may be an oncogene in gastric cancer. High levels of miR-27a could play an important role in gastric malignant evolution, especially cancerization. There is a certain connection between TCM syndrome and pathological changes of the gastric mucosa to some extent, where patients with SQD syndrome had a higher risk of GC.

Coexistence of the hourglass and nodal-line dispersions in Nb3SiTe6 revealed by ARPES.

The non-symmorphic crystal symmetry protection in the layered topological semimetal Nb3SiTe6 can generate exotic band crossings. Herein, high-quality Nb3SiTe6 single crystal was synthesized via chemical vapor transport. The lattice structure of Nb3SiTe6 was characterized by scanning transmission electron microscopy, X-ray diffraction, core-level photoemission, and Raman spectroscopies. Angle-resolved photoemission spectroscopy was used to reveal its topological properties by presenting band structures along different high-symmetry directions. Our data show that nontrivial band features coexist in Nb3SiTe6, including an hourglass-type dispersion formed by two bands along the S-R high-symmetry line, two node lines along the S-X path and the S-R-U path, respectively. These results provide a context for the understanding and exploration of the exotic topological properties of Nb3SiTe6.

Pharmacological treatments of Chinese herbal medicine for irritable bowel syndrome in adults: A network meta-analysis of randomized controlled trials.

INTRODUCTION: Plenty of clinical studies have suggested the value of Chinese herbal medicine (CHM) for patients with irritable bowel syndrome (IBS), but their efficacy and safety have not been systematically concluded yet. This article aimed to compare and rank the therapeutic effect and safety of CHM with routine pharmacotherapies and placebo in the treatment of IBS. METHODS: Randomized controlled trials regarding CHM to treat IBS were searched in six databases from inception to Jan 31, 2020. A network meta-analysis was conducted to analyze the data of included publications. The quality assessment was assessed by Cochrane Handbook and GRADEpro software. The risk ratio was calculated for dichotomous outcomes while the standardized mean difference was used for continuous variables with 95% credible intervals. A Funnel plot was performed to evaluate publication bias. The surface under the cumulative ranking curve was conducted to rank the included interventions. Data were analyzed with STATA 15.0 and Review Manager 5.3. RESULT: 3194 records were searched, and 28 eligible trials involving 3323 patients ere identified. Compared with conventional therapies and placebo, Jianpi-Chushi therapy showed significant improvement in adequate relief and IBS symptom severity scale; Shugan-Jianpi therapy showed the best efficacy in relieving the abdominal pain and abdominal distension; Wenshen-Jianpi therapy had a better effect on avoiding adverse effects and improving stool character. CONCLUSION: This study confirmed that CHM could be beneficial for patients with IBS in relieving their clinical symptoms and should be recommended as alternative therapies. The quality of evidence in this study based on the GRADE system was "low".

Efficacy and safety of Qingre-Chushi therapies in active ulcerative colitis: A network meta-analysis.

BACKGROUND: Ulcerative colitis (UC) is a chronic inflammatory disease with an increasing incidence in the world. Qingre-Chushi therapies (QC) can alleviate clinical symptoms. Therefore, a network meta-analysis was conducted to systematically evaluate the efficacy and safety of QC in the treatment of active UC patients. METHODS: 7 databases were screened and relevant randomized controlled trials were selected. The tools of Cochrane Handbook and the GRADE system were conducted to assess the quality of outcomes. Pooled risk ratio or standard mean difference was calculated with 95% credible interval for outcomes measurement using the random-effects model. The surface under the cumulative ranking curve (SUCRA) was performed to rank the treatments. The larger SUCRA scores, the more effective interventions. RESULTS: A total of 3560 articles were identified and 21 studies including 1829 participants were included for further analysis. Totally, 9 therapies regimens were compared: oral mesalazine, mesalazine enema, mesalazine suppository, oral mesalazine + mesalazine enema, oral QC, oral QC + oral mesalazine, QC enema, oral QC + QC enema, and oral mesalazine + QC enema. Based on the SUCRA plot, oral QC + oral mesalazine was the best treatment in inducing clinical response; oral QC + QC enema had the best efficacy in the improvement of Mayo scores and alleviating abdominal pain; oral mesalazine + mesalazine enema was the optimal therapy in the endoscopic improvement and reducing diarrhea; QC enema + oral mesalazine was the best option in preventing bloody stool. CONCLUSION: This study confirmed the efficacy and safety of QC in treating active UC and suggested that the combination of oral medications with topical can achieve more benefits.

Preparation and characterization of chitosan/poly(vinyl alcohol)/graphene oxide films and studies on their antibiofilm formation activity.

Biocomposite films containing graphene oxide (GO), poly(vinyl alcohol) (PVA), and chitosan (CS) were prepared using the casting/evaporation technique. These as-prepared films were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. Results showed that these three component films could be well mixed in certain conditions and the GO sheets were well dispersed. The better performances such as the water resistance, thermal stability, and mechanical properties have been improved. Meanwhile, good antibacterial activity and antibiofilm formation activity of the prepared CS/PVA/GO films were exhibited against Pseudomonas aeruginosa PAO1. The resulting biocomposite films with combination of CS, PVA, and GO advantages have desirable properties and should be suitable for food and medical packaging applications.

Efficacy and safety of non-pharmacological interventions for irritable bowel syndrome in adults.

BACKGROUND: Although nonpharmacological interventions (NPI) for irritable bowel syndrome (IBS) have been applied clinically, their relative efficacy and safety are poorly understood. AIM: To compare and rank different NPI in the treatment of IBS. METHODS: Five electronic databases were searched from their inception to January 12, 2020. Data of included publications were analyzed using network meta-analysis (NMA). Quality of endpoints were assessed by tools of the Cochrane Handbook and the GRADEpro software. Pooled relative risk or standardized mean difference with their corresponding 95% confidence intervals were used for statistical analysis. Surface under the cumulative ranking curve (SUCRA) probability value was conducted to rank the examined interventions. Sensitivity analysis was performed to verify the robustness of results and test the source of heterogeneity. RESULTS: Forty randomized controlled trials with 4196 participants were included in this NMA. Compared with routine pharmacotherapies and placebo, acupuncture and cognitive behavioral therapy (CBT) had better efficacy in relieving IBS symptoms. Based on the SUCRA values, acupuncture ranked first in improving overall clinical efficacy and avoiding adverse effects. CBT ranked first in lowering the scores of IBS symptom severity scale, self-rating anxiety scale and self-rating depression scale. CONCLUSION: This study confirmed the efficacy and safety of NPI for improving IBS symptoms, which to some extent recommended several interventions for clinical practice.

Different Traditional Herbal Medicines for the Treatment of Gastroesophageal Reflux Disease in Adults.

BACKGROUND/AIMS: Traditional Herbal Medicines (THM) have been being used for gastroesophageal reflux disease (GERD) for a long time, but clinical evidence is still scarce. We evaluated different THM prescriptions for GERD in adults. METHODS: Data added to nine online databases from their inception to November 30, 2019, were systematically searched. All relevant randomized controlled trials (RCTs) were included and were combined with Bayesian network analysis. The Cochrane Collaboration's risk of bias tool and GRADE profiler version 3.6 were respectively employed to evaluate the quality of evidence of outcomes. RESULTS: Seventeen publications involving 1441 participants were retrieved. The results of our analysis suggested that Jianpi therapy+proton pump inhibitors (PPIs) and Ligan Hewei therapy respectively ranked first in overall clinical efficacy and efficacy under gastroscope; Ligan Hewei therapy+PPIs was the optimum intervention in the improvement of acid regurgitation and heartburn. CONCLUSION: This research indicates that Ligan Hewei therapy and Jianpi therapy, or these therapies separately combined with PPIs, should be recommended as appropriate complementary and alternative treatments based on the specific characteristics of GERD. However, additional well-designed RCTs with high methodological quality are still needed for future research.

Enhanced synthesis of alginate oligosaccharides in Pseudomonas mendocina NK-01 by overexpressing MreB.

This study aimed to investigate the effects of cytoskeleton protein MreB on bacterial cell morphology and the synthesis of alginate oligosaccharides (AO) and polyhydroxyalkanoate (PHA) by Pseudomonas mendocina NK-01. To overexpress the mreB gene, an expression vector encoding MreB-GFP fusion protein was constructed. The scanning electron microscope (SEM) showed that cells expressing MreB were longer than the wild ones, which agrees with MreB's relationship with the synthesis of peptidoglycan. Cells expressing the MreB-GFP fusion protein emitted green fluorescence under a fluorescence microscope, suggesting that MreB was functionally expressed in strain NK-01. Under a confocal laser scanning microscope, MreB was observed as located around the cell membrane. Furthermore, the recombinant strain could synthesize 0.961 g/L AO, which was 5.86-fold higher than wild-type strain. Through the medium optimization test, we finally selected the addition of 20 g/L glucose as the optimal glycogen addition for AO fermentation based on a high AO yield and high substrate transformation efficiency. The results indicated that overexpression of MreB affected the cell morphology, the activity of AO polymerase, and the efficiency of AO secretion. However, the synthesis of PHA for recombinant strain was slightly reduced. The results suggested that the overexpression of this cytoskeleton protein affected the yield of specific intracellular and extracellular products.

Multiple CH/π Interactions Maintain the Binding of Aflatoxin B1 in the Active Cavity of Human Cytochrome P450 1A2.

Human cytochrome P450 1A2 (CYP1A2) is one of the key CYPs that activate aflatoxin B1 (AFB1), a notorious mycotoxin, into carcinogenic exo-8,9-epoxides (AFBO) in the liver. Although the structure of CYP1A2 is available, the mechanism of CYP1A2-specific binding to AFB1 has not been fully clarified. In this study, we used calculation biology to predict a model of CYP1A2 with AFB1, where Thr-124, Phe-125, Phe-226, and Phe-260 possibly participate in the specific binding. Site-directed mutagenesis was performed to construct mutants T124A, F125A, F226A, and F260A. Escherichia coli-expressed recombinant proteins T124A, F226A, and F260A had active structures, while F125A did not. This was evidenced by Fe2+∙Carbon monoxide (CO)-reduced difference spectra and circular dichroism spectroscopy. Mutant F125A was expressed in HEK293T cells. Steady kinetic assays showed that T124A had enhanced activity towards AFB1, while F125A, F226A, and F260A were significantly reduced in their ability to activate AFB1, implying that hydrogen bonds between Thr-124 and AFB1 were not important for substrate-specific binding, whereas Phe-125, Phe-226, and Phe-260 were essential for the process. The computation simulation and experimental results showed that the three key CH/π interactions between Phe-125, Phe-226, or Phe-260 and AFB1 collectively maintained the stable binding of AFB1 in the active cavity of CYP1A2.

Preparation of chitosan/poly vinyl alcohol films and their inhibition of biofilm formation against Pseudomonas aeruginosa PAO1.

Poly (vinyl alcohol) (PVA) and chitosan (CH)-based blend films were prepared via a simple mixing and casting method. The films were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and ultraviolet-visible spectroscopy (UV-vis). Mechanical properties, thermogravimetric (TG), derivative thermogravimetric (DTG), and the inhibition of biofilm formation against Pseudomonas aeruginosa PAO1 (P. aeruginosa PAO1) of CH/PVA films were investigated. The results indicated that CH and PVA in the blend films interacted by physical crosslinks consisting of intermolecular hydrogen bonds and intermolecular hydrogen bonds with compatibility, and were more thermally-stable than that of PVA. CH addition decreased the tensile strength and the light transmittance. CH60:PVA40 film showed notable activity against adhesion and inhibited biofilm formation of P. aeruginosa PAO1, indicating that CH60:PVA40 film could be applied as an antimicrobial and biofilm inhibiting food packaging material.

An engineered Pseudomonas putida can simultaneously degrade organophosphates, pyrethroids and carbamates.

Agricultural soils are often polluted with a variety of pesticides. Unfortunately, natural microorganisms lack the capacity to simultaneously degrade different types of pesticides. Currently, synthetic biology provides powerful approaches to create versatile degraders. In this work, a biosafety strain Pseudomonas putida KT2440 was engineered for simultaneous degradation of organophosphates, pyrethroids, and carbamates, enhanced oxygen-sequestering capability, and real-time monitoring by targeted insertion of four pesticide-degrading genes, vgb, and gfp into the chromosome using a scarless genome-editing method. The resulting recombinant strain, designated as P. putida KTUe, could completely degrade 50mg/L methyl parathion, chlorpyrifos, fenpropathrin, cypermethrin, carbofuran and carbaryl within 30h when incubated in M9 minimal medium supplemented with 20g/L glucose. In soil remediation studies, all the tested six pesticides (50mg/kg soil each) were completely removed in soils inoculated with P. putida KTUe within 15days. Moreover, Vitreoscilla hemoglobin (VHb)-expressing P. putida KTUe grew faster than P. putida KTUd without VHb expression under oxygen-limited conditions, suggesting that VHb may enhance the capability of this recombinant strain to sequester oxygen. Furthermore, the green fluorescence was observed on the P. putida KTUe cells, suggesting that this green fluorescent protein (GFP)-marked strain may be tracked by fluorescence during bioremediation. Therefore, this recombinant strain may serve as a promising candidate for in situ bioremediation of soil contaminated with multiple pesticides. This work not only underscores the value of P. putida KT2440 as an ideal host for bioremediation but also highlights the power of synthetic biology for expanding the degradation capability of natural degraders.

Simultaneous hydrolysis of carbaryl and chlorpyrifos by Stenotrophomonas sp. strain YC-1 with surface-displayed carbaryl hydrolase.

Many sites are often co-contaminated with multiple pesticides. To date, there are no reports on simultaneous degradation of different classes of pesticides by a natural microorganism. In this work, we aim at constructing a live biocatalyst able to simultaneously hydrolyze carbaryl and chlorpyrifos. For this purpose, carbaryl hydrolase (CH) was displayed on the cell surface of a chlorpyrifos-degrading bacterium Stenotrophomonas sp. strain YC-1 using N- and C-terminal domain of ice nucleation protein (INPNC) from Pseudomonas syringae INA5 as an anchoring motif. The localization of INPNC-CH fusion protein in the outer membrane fraction was demonstrated by cell fractionation followed by Western blot analysis. Surface display of INPNC-CH was further confirmed by proteinase accessibility experiment and immunofluorescence microscope. CH was present in an active form on cell surface without causing any growth inhibition, suggesting that the INP-based display system is a useful tool for surface expression of macromolecular heterologous proteins on the bacterial cell surface. Because surface-displayed CH has free access to pesticides, this bacterium can be used as a whole-cell biocatalyst for efficient hydrolysis of pesticides.