Biochemical characterization and cleavage specificities analyses of three endo-1,3-fucanases within glycoside hydrolase family 174

Sulfated fucans have garnered extensive research interest in recent decades due to their varied bioactivity. Fucanases are important tools for investigating sulfated fucans. This study reported the bioinformatic analysis and biochemical properties of three GH174 family endo-1,3-fucanases. Wherein, Fun174Rm and Fun174Sb showed the highest optimal reaction temperature among the reported fucanases, and Fun174Sb possessed favorable thermostability and catalysis efficiency. Fun174Rm displayed a random endo-acting manner, while Fun174Ri and Fun174Sb hydrolyzed sulfated fucan in processive manners. UPLC-MS and NMR analyses confirmed that the three enzymes catalyze cleavage of the α(1 → 3)-bonds between Fucp2S and Fucp2S in the sulfated fucan from Isostichopus badionotus. These enzymes demonstrated novel cleavage specificities, which could accept α-Fucp2S residues at subsites -1 and + 1. The acquiring of these biotechnological tools would be beneficial to the in-depth research of sulfated fucans.

The Discovery of a Multidomain Mannanase Containing Dual-Catalytic Domain of the Same Activity: Biochemical Properties and Synergistic Effect

In recent years, the wide application of mannan has driven the demand for the exploration of mannanase. As one of the main components of hemicellulose, mannan is an important polysaccharide that ruminants need to degrade and utilize, making rumen a rich source of mannanases. In this study, gene mining of mannanases was performed using bioinformatics, and potential dual-catalytic domain mannanases were heterologously expressed to analyze their properties. The hydrolysis pattern and enzymatic products were identified by liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS). A dual-catalytic domain mannanase Man26/5 with the same function as the substrate was successfully mined from the genome of cattle rumen microbiota. Compared to the single-catalytic domain, its higher thermal stability (≤50 °C) and catalytic efficiency confirm the synergistic effect between the two catalytic domains. It exhibited a unique "crab-like" structure where the CBM located in the middle is responsible for binding, and the catalytic domains at both ends are responsible for cutting. The exploration of its multidomain structure and synergistic patterns could provide a reference for the artificial construction and molecular modification of enzymes.

Characterization and structural identification of a family 16 carbohydrate-binding module (CBM): First structural insights into porphyran-binding CBM

Porphyran is a favorable functional polysaccharide widely distributed in Porphyra. It displays a linear structure majorly constituted by alternating 1,4-linked α-l-galactopyranose-6-sulfate (L6S) and 1,3-linked β-d-galactopyranose (G) units. Carbohydrate-binding modules (CBMs) are desired tools for the investigation and application of polysaccharides, including in situ visualization, on site and specific assay, and functionalization of biomaterials. However, only one porphyran-binding CBM has been hitherto reported, and its structural knowledge is lacking. Herein, a novel CBM16 family domain from a marine bacterium Aquimarina sp. BL5 was discovered and expressed. The recombinant protein AmCBM16 exhibited the desired specificity for porphyran. Bio-layer interferometry assay revealed that the protein binds to porphyran tetrasaccharide (L6S-G)2 with an association constant of 1.3 × 103 M-1. The structure of AmCBM16 was resolved by the X-ray crystallography, which displays a β-sandwich fold with two antiparallel β-sheets constituted by 10 β-strands. Site-directed mutagenesis analysis demonstrated that the residues Gly-30, Trp-31, Lys-88, Lys-123, Phe-125, and Phe-127 play dominant roles in AmCBM16 binding. This study provides the first structural insights into porphyran-binding CBM.

Discovery and characterization of a novel carbohydrate-binding module: a favorable tool for investigating agarose

BACKGROUND

Agarose, mainly composed of 3,6-anhydro-α-l-galactopyranose (LA) and β-d-galactopyranose (G) units, is an important polysaccharide with wide applications in food, biomedical and bioengineering industries. Carbohydrate-binding modules (CBMs) are favorable tools for the investigations of polysaccharides. Few agarose-binding CBMs have been hitherto reported, and their binding specificity is unclear.

RESULTS

An unknown domain with a predicted β-sandwich fold was discovered from a β-agarase of the marine bacterium Wenyingzhuangia fucanilytica CZ1127T . The expressed protein WfCBM101 could bind to agarose and exhibited relatively weak affinity for porphyran, with no affinity for the other seven examined polysaccharides. The protein binds to the tetrasaccharide (LA-G)2 , but not to the major tetrasaccharide contained in porphyran. The sequence novelty and well-defined binding function of WfCBM101 shed light on a novel CBM family (CBM101). Furthermore, the feasibility of WfCBM101 for visualizing agarose in situ was confirmed.

CONCLUSION

A novel CBM, WfCBM101, with a desired specificity for agarose was discovered and characterized, which represents a new CBM family. The CBM could be utilized as a promising tool for studies of agarose. © 2023 Society of Chemical Industry.

Action Pattern of a Novel G-Specific Alginate Lyase: Determination of Subsite Specificity by HPAEC-PAD/MS

G-specific alginate lyases are important tools for alginate fragment biodegradation and oligosaccharide production, which have great potential in alginate refining research. In this research, a novel G-specific alginate lyase Aly7Ce was cloned, expressed, and characterized, with the optimal reaction conditions at 30 °C and pH 8.0. By employing the UPSEC-VWD-MS method, Aly7Ce was confirmed as a random endoacting alginate lyase. Its minimum substrate was tetrasaccharide, and the final product majorly consisted of disaccharide to tetrasaccharide. HPAEC-PAD/MS method was employed to investigate the structurally different unsaturated alginate oligosaccharides. The substrate recognition and subsite specificity of Aly7Ce were revealed by detecting the oligosaccharide pattern in the enzymatic products with oligosaccharides or polysaccharides as substrates. Aly7Ce mainly attacked the second glycosidic linkage from the nonreducing end of oligosaccharide substrates. The subsite specificity of Aly7Ce was revealed as -2 (M/G), - 1 (G), + 1 (M/G), and +2 (M/G). The regular oligosaccharide products of Aly7Ce could be applied for the efficient preparation of ΔG, ΔGG, and ΔGGG with high purity. The G-specific alginate lyase Aly7Ce with a well-defined product composition and action pattern provided a novel tool for the modification and structural elucidation of alginate, as well as for the targeted preparation of oligosaccharides.

Discovery of a catalytic domain defines a new glycoside hydrolase family containing endo-1,3-fucanase

Sulfated fucans are important marine polysaccharides with various bioactivities. Fucanases are desirable tools for the structural elucidations and oligosaccharides preparation of sulfated fucans. Herein, a gene with unknown function was screened from a sulfated fucan utilization locus in genome of marine bacterium Wenyingzhuangia aestuarii OF219 with the assistance of a machine learning approach on the structural biology. An undefined catalytic domain that presented in this gene was further cloned and expressed in Escherichia coli. Utilizing a sulfated fucan tetrasaccharide with definite structure as substrate, the endo-acting cleavage point of expressed protein (named Fun187A) was identified as the α-l-1,3-glycosidic bond between Fucp and Fucp(2OSO3-). Fun187A demonstrated a novel cleavage specificity, that is the subsite -1 could tolerate α-l-Fucp, and the subsite +1 could tolerate α-l-Fucp(2OSO3-). A homologue of Fun187A was also validated to display the endo-1,3-fucanse activity. The sequence novelty of Fun187A and its homologue defines a new glycoside hydrolase family, GH187.

Identification and structural characterization of a novel chondroitin sulfate-specific carbohydrate-binding module: The first member of a new family, CBM100

Chondroitin sulfate is a biologically and commercially important polysaccharide with a variety of applications. Carbohydrate-binding module (CBM) is an important class of carbohydrate-binding protein, which could be utilized as a promising tool for the applications of polysaccharides. In the present study, an unknown function domain was explored from a putative chondroitin sulfate lyase in PL29 family. Recombinant PhCBM100 demonstrated binding capacity to chondroitin sulfates with Ka values of 2.1 ± 0.2 × 106 M-1 and 6.0 ± 0.1 × 106 M-1 to chondroitin sulfate A and chondroitin sulfate C, respectively. The 1.55 Å resolution X-ray crystal structure of PhCBM100 exhibited a β-sandwich fold formed by two antiparallel β-sheets. A binding groove in PhCBM100 interacting with chondroitin sulfate was subsequently identified, and the potential of PhCBM100 for visualization of chondroitin sulfate was evaluated. PhCBM100 is the first characterized chondroitin sulfate-specific CBM. The novelty of PhCBM100 proposed a new CBM family of CBM100.

Characterization of a novel carbohydrate-binding module specifically binding to the major structural units of porphyran

Porphyran is a promising bioactive polysaccharide majorly composed of 4-linked α-l-galactopyranose-6-sulfate (L6S) and 3-linked β-d-galactopyranose (G) disaccharide repeating units. Carbohydrate-binding modules (CBMs) have been verified to be essential tools for investigating polysaccharides. However, no confirmed CBM binding to porphyran has been hitherto reported. In this study, an unknown domain with a predicted β-sandwich fold from a potential GH86 porphyranase was discovered, and further recombinantly expressed. The CBM protein (named FvCBM99) presented a desired specificity for porphyran tetrasaccharide with an affinity constant of 1.9 × 10-4 M, while it could not bind to agarose tetrasaccharide. The sequence novelty and well-defined function of FvCBM99 and its homologs reveal a new CBM family, CBM99. Besides, the application potential of FvCBM99 in in situ visualization of porphyran was demonstrated. The discovery of FvCBM99 provides a favorable tool for future studies of porphyran.

Characterization of a novel endo-1,3-fucanase from marine bacterium Wenyingzhuangia fucanilytica reveals the presence of diversity within glycoside hydrolase family 168

Sulfated fucans attract increasing research interests in recent decades for their various physiological activities. Fucanases are indispensable tools for the investigation of sulfated fucans. Herein, a novel GH168 family endo-1,3-fucanase was cloned from the genome of marine bacterium Wenyingzhuangia fucanilytica. The expressed protein Fun168D was a processive endo-acting enzyme. Ultra performance liquid chromatography-high resolution mass spectrum and NMR analyses revealed that the enzyme cleaved the α-1 → 3 bonds between α-l-Fucp(2OSO₃^-) and α-l-Fucp(2OSO₃^-) in sulfated fucan from Isostichopus badionotus, and α-1 → 3 bonds between α-l-Fucp(2OSO₃^-) and α-l-Fucp(2,4OSO₃^-) in sulfated fucan from Holothuria tubulosa. Fun168D would prefer to accept α-l-Fucp(2,4OSO₃^-) than α-l-Fucp(2OSO₃^-) at subsite +1, and could tolerate the absence of fucose residue at subsite +2. The novel cleavage specificity and hydrolysis pattern revealed the presence of diversity within the GH168 family, which would facilitate the development of diverse biotechnological tools for the molecule tailoring of sulfated fucan.

The characteristic structure of funoran could be hydrolyzed by a GH86 family enzyme (Aga86A_Wa): Discovery of the funoran hydrolase

Funoran, agarose and porphyran all belong to agaran, and share the similar skeleton. Although the glycoside hydrolase for agarose and porphyran, i.e. agarase and porphyranase, have been extensively studied, the enzyme hydrolyzing funoran has not been reported hitherto. The crystal structure of a previously characterized GH86 β-agarase Aga86A_Wa showed a large cavity at subsite -1, which implied its ability to accommodate sulfate ester group. By using glycomics and NMR analysis, the activity of Aga86A_Wa on the characteristic structure of funoran was validated, which signified the first discovery of funoran hydrolase, i.e. funoranase. Aga86A_Wa hydrolyzed the β-1,4 glycosidic bond between β-d-galactopyranose-6-sulfate (G6S) and 3,6-anhydro-α-l-galactopyranose (LA) unit of funoran, and released disaccharide LA-G6S as the predominant end product. Considering the hydrolysis pattern, we proposed to name the activity represented by Aga86A_Wa on funoran as "β-funoranase" and suggested to assign it an EC number.

[Bioinformatics analysis of the RNA binding protein DDX39 of Toxoplasma gondii]

OBJECTIVE

To analyze the RNA binding protein of Toxoplasma gondii (TgDDX39) using bioinformatics technology, and to evaluate the immunogenicity of TgDDX39, so as to provide insights into development of toxoplasmosis vaccines.

METHODS

The amino acid sequences of TgDDX39 were retrieved from the ToxoDB database, and the physicochemical properties, transmembrane structure domain, signal peptide sites, post-translational modification sites, coils, secondary and tertiary structures, hydrophobicity, and antigenic epitopes of the TgDDX39 protein were predicted using online bioinformatics tools, incluiding ProtParam, TMHMM 2.0, SignalP 5.0, NetPhos 3.1, COILS, SOPMA, Phyre2, ProtScale, ABCpred, SYFPEITHI and DNA-STAR.

RESULTS

TgDDX39 protein was predicted to be an unstable hydrophilic protein with the molecular formula of C2173H3458N598O661S18, which contained 434 amino acids and had an estimated molecular weight of 49.1 kDa and a theoretical isoelectric point of 5.55. The protein was predicted to have an extremely low possibility of signal peptides, without transmembrane regions, and contain 27 phosphorylation sites. The β turn and random coils accounted for 39.63% of the secondary structure of the TgDDX39 protein, and a coiled helix tended to produce in one site. In addition, the TgDDX39 protein contained multiple B and T cell antigenic epitopes.

CONCLUSIONS

Bioinformatics analyses predict that TgDDX39 protein has high immunogenicity and contains multiple antigenic epitopes. TgDDX39 protein is a potential candidate antigen for vaccine development.

Stereotactic Radiotherapy or Whole Brain Radiotherapy Combined with Pyrotinib and Capecitabine in HER2-Positive Advanced Breast Cancer Patients with Brain Metastases (BROPTIMA): A Prospective, Phase Ib/II Single-Arm Clinical Study

PURPOSE/OBJECTIVE(S)

Approximately half of patients with advanced HER2-positive breast cancer (BC) will develop brain metastases (BM) over time. Local therapy including stereotactic radiotherapy (SRT) and whole brain radiotherapy (WBRT) is the main initial treatment in malignant tumor patients with BM. However, more than 50% patients after radiotherapy in one year suffered intracranial recurrence. Pyrotinib, a small molecule, irreversible, pan-ErbB receptor tyrosine kinase inhibitor (TKI), has a high potency for controlling BM and reducing the occurrence of brain metastases in advanced HER2-positive BC patients. We hypothesized that SRT or WBRT combined with pyrotinib and capecitabine could decrease intracranial progression in HER2 positive BC with newly diagnosed BM.

MATERIALS/METHODS

In this prospective single-arm phase Ib/II trial (NCT04582968), eligible patients were assigned to either fractionated stereotactic radiotherapy (FSRT) or whole-brain radiation therapy (WBRT), combined with pyrotinib and capecitabine. The primary endpoint was one-year CNS progression-free survival (PFS) rate. Secondary endpoints included intracranial objective response rate (IC-ORR) according to RANO-BM criteria, progression-free survival (PFS), overall survival (OS) and evaluation of safety and neurocognitive function.

RESULTS

From January 2020 to August 2022, 40 patients were enrolled. Twenty-nine patients were treated with FSRT in 8 Gy per fraction with 3 to 5 fractions and 11 were treated with WBRT in 3 Gy per fraction with 10 fractions, and then received chemotherapy in a time frame starting from 0 to 7 days after radiotherapy. At a median follow-up of 17.3 months, 1-year CNS-PFS rate was 74.9% (95% CI 61.9-90.7%) and median CNS-PFS was 18 months (95% CI, 15.5 to NA months). One-year PFS rate was 66.9% (53.1-84.2%) and median PFS time was 17.6 months (95% CI 12.8-34.1 months). The best intracranial response rate (IC-ORR: complete response and partial response) was 92.5% (37/40). The most common grade 3 or worse toxicity was diarrhea (7.5%) and asymptomatic radiation necrosis was detected in 4 of 67(6.0%) lesions treated with FSRT. No differences of neurocognitive function evaluated by MMSE (Mini-Mental State Exam) were observed between different groups at any time point.

CONCLUSION

Radiotherapy combined with pyrotinib and capecitabine resulted in a promising efficacy that crossed the pre-specified boundary in patients with HER2-positive advanced breast cancer with brain metastases. This is the first prospective study showing the efficacy and safety of CNS radiotherapy concurrent with pyrotinib and capecitabine in patients with BM from HER2-positive breast cancer. Further investigation in a randomized controlled study is warranted.

Structural characterization on a β-agarase Aga86A_Wa from Wenyingzhuangia aestuarii reveals the prevalent methyl-galactose accommodation capacity of GH86 enzymes at subsite -1

Agarans are sulfated galactans extracted from red algae with high structural complexity, of which natural methylation often occurs on the O-6 position of its β-d-galactopyranose units. Although many agaran degrading enzymes, including agarases and porphyranases, have been characterized, little attention has been paid to the tolerance of methyl groups at cleavage subsites. In this study, the structure of GH86 β-agarase Aga86A_Wa from Wenyingzhuangia aestuarii was determined by X-ray crystallography and investigated from a structural biology perspective. The structure indicated that an accommodation pocket formed by F367, Y280, and Q326 at subsite -1 contributes to the methyl-galactose tolerance of Aga86A_Wa. Furthermore, we found that similar accommodation pockets were present in the structures of two other GH86 enzymes BuGH86 from Bacteroides uniformis and BpGH86A from Phocaeicola plebeius, and their previously undisclosed methyl-galactose tolerance was verified, validating the function of the pockets. Phylogenetic analysis, structural modeling, and hydrolysis product characterization suggested that the methyl-galactose accommodation capacity at subsite -1 was prevalent in GH86 members. These findings achieve a better understanding of the function and mechanism of GH86 agaran degrading enzymes, and will facilitate the precise preparation of agaran oligosaccharides by employing defined tools.

Discovery of a sulfated fucan-specific carbohydrate-binding module: The first member of a new carbohydrate-binding module family

Sulfated fucan is an important functional polysaccharide with various physiological activities. Carbohydrate-binding module (CBM) is a representative class of carbohydrate-binding protein, which could be employed as a favorable tool for the investigations and applications of polysaccharides. Nevertheless, only one confirmed sulfated fucan-binding CBM has been hitherto reported. In the present study, an unknown domain with a predicted β-sandwich fold was discovered from a fucanase Fun174A, and further cloned and heterologously expressed in Escherichia coli. The expressed protein Fun174A-CBM displayed a specific binding capacity to sulfated fucan. The bio-layer interferometry assays showed that the protein could bind to the sulfated fucan tetrasaccharide with an affinity constant of 2.83 × 10^-4 M. Fun174A-CBM shared no significant sequence similarity to any identified CBMs, indicating that it represents a new CBM family. The discovery of Fun174-CBM and the novel CBM family would be beneficial to the investigations of sulfated fucan-binding proteins.

Sulfated fucan could serve as a species marker of sea cucumber with endo-1,3-fucanase as the essential tool

In the past few decades, sulfated fucan from sea cucumber had attracted considerable interest owing to its abundant physiological activities. Nevertheless, its potential for species discrimination had not been investigated. Herein, particular attention was given to sea cucumber Apostichopus japonicus, Acaudina molpadioides, Holothuria hilla, Holothuria tubulosa, Isostichopus badionotus and Thelenota ananas to examine the feasibility of sulfated fucan as a species marker of sea cucumber. The enzymatic fingerprint suggested that sulfated fucan exhibited significant interspecific discrepancy and intraspecific stability, which revealed that sulfated fucan could serve as the species marker of sea cucumber, by utilizing the overexpressed endo-1,3-fucanase Fun168A and the ultra-performance liquid chromatography-high resolution mass spectrum. Moreover, oligosaccharide profile of sulfated fucan was determined. The oligosaccharide profile combined with hierarchical clustering analysis and principal components analysis further confirmed that sulfated fucan could serve as a marker with a satisfying performance. Besides, load factor analysis showed that the minor structure of sulfated fucan also contributed to the sea cucumber discrimination, besides the major structure. The overexpressed fucanase played an indispensable role in the discrimination, due to its specificity and high activity. The study would lead to a new strategy for species discrimination of sea cucumber based on sulfated fucan.

[Clinical and endoscopic characteristics of adult celiac disease]

Objective: The study aimed to analyze the clinical and endoscopic characteristics of adult celiac disease (CD) to provide a scientific basis for more effective CD diagnosis and treatment. Methods: In this cross-sectional study, the clinical and endoscopic data of 96 adult CD patients treated in the Department of Gastroenterology of the People's Hospital of Xinjiang Uygur Autonomous Region from March 2016 to December 2021 were retrospectively collected and analyzed. Results: A total of 96 CD patients were diagnosed, including 33 men and 63 women. The average age was 47±14 years (range, 18-81 years). The disease occurred mainly in the age group of 31-60 years. The median course of the disease was 2.0 (0.2-40.0) years. There were 41 (42.7%) classical and 55 (57.3%) non-classical CD patients. All patients with classical CD showed chronic diarrhea, often accompanied by abdominal pain (46.3%, 19/41), abdominal distension (17.1%, 7/41), anemia (65.9%, 27/41), and chronic fatigue (48.8%, 20/41). The main manifestations of non-classical CD were chronic abdominal pain (58.2%, 32/55), abdominal distension (32.7%, 18/55), anemia (40.0%, 22/55), and osteopenia/osteoporosis (38.2%, 21/55). Compared with non-classical CD, anemia developed more frequently in classical CD, and the difference was statistically significant (P = 0.012). The incidence of complications in CD patients was 36.5% (35/96), and the main complications were thyroid disease (19.8%, 19/96), connective tissue disease (6.2%, 6/96), and kidney disease (6.2%, 6/96). There was no significant difference between classical and non-classical CD (P>0.05). The frequency of endoscopic manifestations in CD patients was 84.4% (81/96). Duodenal bulb endoscopy showed nodular changes (72.9%, 70/96), grooved changes (10.4%, 10/96), and focal villous atrophy (9.4%, 9/96). The main manifestations of descending endoscopy were the decrease, flattening, or disappearance of duodenal folds (43.8%, 42/96), scallop-like changes (38.5%, 37/96), and nodular changes (34.4%, 33/96). Conclusions: Adult CD patients are mostly female. CD occurred mainly in the age group of 31-60 years. The clinical manifestations were mainly those of non-classical CD. Some patients often had other autoimmune diseases. Patients with characteristic endoscopic manifestations should be warned about the possibility of developing CD. Clinicians should strengthen the understanding of CD and reduce the related rates of missed diagnosis.

Establishment of a carbohydrate binding module-based lateral flow immunoassay method for identifying hyaluronic acid

Hyaluronic acid is a commercially important polysaccharide with wide applications. Along with the rapid development of hyaluronic acid-based products, their authenticity has aroused considerable attention from consumers. In the present study, a carbohydrate-binding module (CBM) SrCBM70 was cloned and expressed. The protein could specifically bind to hyaluronic acid with a strong affinity. A novel method for the identification of hyaluronic acid was subsequently established by integrating SrCBM70 into the lateral flow immunoassay (LFIA). Its detection limit for hyaluronic acid was approximately 0.1 μg/mL, and the assay could be completed in 5 min. The feasibility of this method in the authenticity identification of commercialized products containing hyaluronic acid was confirmed. The establishment of the SrCBM70-based LFIA method provided a solution for the on-site authenticity identification and would facilitate the market supervision of hyaluronic acid-based products.

Characterization of a Novel Carrageenan-Specific Carbohydrate-Binding Module: a Promising Tool for the In Situ Investigation of Carrageenan

Carrageenan is a commercially important polysaccharide widely applied in the food industry. Specific probes are critical tools for the in situ investigation of polysaccharides, whereas the carrageenan-specific probes are limited at present. Carbohydrate-binding modules (CBMs) could serve as specific probes for the in situ investigation of polysaccharides. In the present study, an unknown function module from the κ-carrageenase Cgk16A was cloned and expressed in Escherichia coli. The expressed protein Cgk16A-CBM92 could specifically bind to carrageenan. Its novelty sheds light on a new CBM family (CBM92) as the founding member. Furthermore, a fluorescent probe was successfully constructed by fusing Cgk16A-CBM92 with a green fluorescent protein. The application potential of Cgk16A-CBM92 as a probe served in the in situ visualization of carrageenan was evaluated. The discovery of Cgk16A-CBM92 provided a promising tool for the in situ investigation of carrageenan.

[Study on the difference of curative effect of conventional mercury displacement treatment on mercury in brain and kidney]

Objective: To explore the expulsion effect of sodium dimercaptopropanesulfonate (DMPS) on mercury in different organs of mercury poisoning and the therapeutic effect of glutathione (GSH) combined with antioxidant therapy on mercury poisoning. Methods: In February 2019, 50 SPF male SD rats were randomly divided into 5 groups, 10 rats in each group: A (saline negative control group) , B (HgCL2 positive control group) , treatment group (C: intramuscular injection of DMPS 15 mg/kg treatment, D: intramuscular injection of DMPS30 mg/kg treatment, E: intramuscular injection of DMPS 15 mg/kg and intraperitoneal injection of GSH200 mg/kg treatment) . Rats in group B, C, D and E were subcutaneously injected with mercury chloride solution (1 mg/kg) to establish a rat model of subacute mercury poisoning kidney injury. Rats in group A were subcutaneously injected with normal saline. After the establishment of the model, rats in the treatment group were injected with DMPS and GSH. Rats in group A and group B were injected with normal saline. At 21 d (treatment 7 d) and 28 d (treatment 14 d) after exposure, urine and blood samples of 5 rats in each group were collected. Blood biochemistry, urine mercury, urine microalbumin and mercury content in renal cortex, cerebral cortex and cerebellum were detected. Results: After exposure to mercury, the contents of mercury in renal cortex, cerebrum and cerebellum of rats in group B, C, D and E increased, and urine microalbumin increased. Pathology showed renal tubular injury and renal interstitial inflammation. Compared with group B, urinary mercury and renal cortex mercury in group C, D and E decreased rapidly after DMPS treatment, and there was no significant decrease in mercury levels in cerebellum and cerebral cortex of rats, accompanied by transient increase in urinary albumin after DMPS treatment (P<0.05) ; the renal interstitial inflammation in group E was improved after GSH treatment. There was a positive correlation between urinary mercury and the contents of mercury in renal cortex, cerebral cortex and cerebellum (r=0.61, 0.47, 0.48, P<0.05) . Conclusion: DMPS mercury expulsion treatment can significantly reduce the level of metal mercury in the kidney, and there is no significant change in the level of metal mercury in the cortex and cerebellum.

Characterization of a sulfated fucan-specific carbohydrate-binding module: A promising tool for investigating sulfated fucans

Sulfated fucans are important polysaccharides with diverse biological and biomedical activities. Carbohydrate-binding modules (CBMs) could serve as beneficial tools for the investigation of polysaccharides. Nevertheless, no sulfated fucan-binding CBM has been hitherto discovered. In the present study, a novel CBM47 domain was cloned from the marine bacterium Wenyingzhuangia fucanilytica, and heterologously expressed in Escherichia coli. The expressed protein WfCBM47 exhibited a specific binding capacity to sulfated fucans with the backbone composed of 1,3-α-l-fucopyranose residues. Furthermore, a fluorescent probe was successfully constructed by fusing WfCBM47 with a green fluorescent protein, based on which the in situ visualization of sulfated fucan in the sea cucumber (Apostichopus japonicus) body wall was implemented for the first time. The discovery of WfCBM47 provided a promising tool for future investigations on sulfated fucans.

Tumor invasion front morphology: a novel prognostic factor for intrahepatic cholangiocarcinoma

OBJECTIVE

To explore the prognostic value of the morphology of tumor invasion front (TIF) in Intrahepatic Cholangiocarcinoma (ICC).

PATIENTS AND METHODS

Seventy-four ICC patients with complete clinicopathological data and follow-up information were enrolled in our study. The most typical morphology of TIF of each case will be classified as low-grade group or high-grade group after evaluation by two pathologists. The clinicopathological characteristics, disease-free survival (DFS), and overall survival (OS) were compared between the two groups.

RESULTS

A total of 26 (35.3%) patients were assigned to low-grade group, while 48 (64.7%) patients were assigned to high-grade group. High-grade group was associated with higher CA19-9 (p=0.032), poor differentiation (p=0.050), larger tumor diameter (p=0.016), advanced T staging (p=0.048), and higher incidence of lymph node (LN) metastasis (0.014). No significant associations were found in demographic and clinical characteristics between the two groups. On multivariable analysis, high-grade group was a significant independent predictor of worse DFS (HR=0.433, 95% CI=0.235-0.800, p=0.002) and OS (HR=0.363, 95% CI=0.187-0.704, p=0.003).

CONCLUSIONS

High-grade morphology of TIF was an independent prognostic factor of ICC.

Discovery and Characterization of an Endo-1,3-Fucanase From Marine Bacterium Wenyingzhuangia fucanilytica: A Novel Glycoside Hydrolase Family

Sulfated fucans are important marine polysaccharides widely distributed in brown algae and echinoderms, which gained increasing research interest for their various biological and biomedical activities. Fucanases could serve as tools in the bioconversion and structural investigation of sulfated fucans. A few gene-defined endo-1,4-fucanases have been characterized, while the sequence of endo-1,3-fucanase remain unstudied. Here, an endo-1,3-fucanase gene funA was screened from the genome of marine bacterium Wenyingzhuangia fucanilytica CZ1127^T using transcriptomics. None of the previously reported glycoside hydrolase domains were predicted in the enzyme FunA, which hydrolyzed sulfated fucans in a random endo-acting manner. Ultrahigh performance size exclusion chromatography-mass spectrometry and nuclear magnetic resonance analyses revealed that FunA specifically cleaves α-1,3 glycosidic linkage between 2-O-sulfated and non-sulfated fucose residues. FunA exhibited transglycosylating activity with glycerin, methanol, and L-fucose as acceptors. D206 and E264 were critical for the functioning of FunA as identified by the site-directed mutagenesis. Another five homologs of FunA were confirmed to possess endo-1,3-fucanase activities. This is the first report on the sequence of endo-1,3-fucanase. The novelty of FunA and its homologs in sequences and activity shed light on a novel glycoside hydrolase family, GH168.

Characterization of a Novel Porphyranase Accommodating Methyl-galactoses at Its Subsites

Porphyran is the major polysaccharide of laver and mainly composed of 3-linked β-d-galactopyranose (G) and 4-linked α-l-galactopyranose-6-sulfate (L6S) units. Structural heterogeneity of porphyran highly originates from the natural methylation on the O-6 position of G units (GMe). Here, a GH16 porphyranase Por16C_Wf was cloned from a porphyran-related polysaccharide utilization locus of Wenyingzhuangia fucanilytica and expressed in Escherichia coli. It hydrolyzed porphyran in a random endo-acting manner. Using a glycomics strategy combining liquid chromatography-mass spectrometry and glycoinformatics, the subsite specificity was clarified. Por16C_Wf accommodated both G and GMe at subsites -1 and +2. This is the first report on the sequence of porphyranases hydrolyzing consecutive methyl-porphyranobiose moieties, which shed light on the diversity in subsite specificity of porphyranases. Por16C_Wf was the first characterized enzyme in subfamily 14 of the GH16 family. The defined and novel activity of Por16C_Wf implied that it could serve as a favorable tool in the full degradation and structural investigation of porphyran.

Combination of Imaging Features and Clinical Biomarkers Predicts Positive Pathology and Microbiology Findings Suggestive of Spondylodiscitis in Patients Undergoing Image-Guided Percutaneous Biopsy

BACKGROUND AND PURPOSE

Pathology and microbiology results for suspected spondylodiscitis on MR imaging are often negative in up to 70% of cases. We aimed to predict whether MR imaging features will add diagnostic value when combined with clinical biomarkers to predict positive findings of spondylodiscitis on pathology and/or microbiology from percutaneous biopsy.

MATERIALS AND METHODS

In this retrospective single-center institutional review board-approved study, patients with radiologically suspected spondylodiscitis and having undergone percutaneous biopsies were assessed. Demographic characteristics, laboratory values, and tissue and blood cultures were collected. Pathology and microbiology results were used as end points. Three independent observers provided MR imaging-based scoring for typical MR imaging features for spondylodiscitis. Multivariate logistic regression and receiver operating characteristic analysis were performed to determine an optimal combination of imaging and clinical biomarkers in predicting positive findings on pathology and/or microbiology from percutaneous biopsy suggestive of spondylodiscitis.

RESULTS

Our patient cohort consisted of 72 patients, of whom 33.3% (24/72) had spondylodiscitis. The mean age was 63 ± 16 years with a male/female ratio of 41:31. Logistic regression revealed a combination with an area under the curve of 0.72 for pathology and 0.68 for pathology and/or microbiology. Epidural enhancement on MR imaging improved predictive performance to 0.87 for pathology and 0.78 for pathology and/or microbiology.

CONCLUSIONS

Our findings demonstrate that epidural enhancement on MR imaging added diagnostic value when combined with clinical biomarkers to help predict which patients undergoing percutaneous biopsy will have positive findings for spondylodiscitis on pathology and/or microbiology.

Expression and characterization of a novel alginate-binding protein: A promising tool for investigating alginate

Alginate is a commercially important polysaccharide widely applied in various industries. Carbohydrate-binding proteins could be utilized as desirable tools in the investigation and further applications of polysaccharides. Few alginate-binding proteins have hitherto been characterized and reported. In the present study, a novel alginate-binding protein ABP_Wf, consisting of two "orphan" carbohydrate-binding modules, was cloned from a predicted alginate utilization locus of marine bacterium Wenyingzhuangia funcanilytica, and expressed in Escherichia coli. ABP_Wf exhibited a specific binding capacity to alginate, and the association constant (K_a) and affinity (K_D) were 1.94 × 10³ M^-1s^-1 and 1.16 × 10^-6 M. It was confirmed that the binding capacity of ABP_Wf to alginate is attributed to its constituent CBM16 domain rather than the CBM44 domain. The potentials of ABP_Wf in the semi-quantitative detection and the in situ visualization of alginate were evaluated, which implied that ABP_Wf could be served as a promising tool for investigating alginate.

[Analysis of baseline liver biochemical parameters in 324 cases with novel coronavirus pneumonia in Shanghai area]

Objective: To summarize the clinical characteristics and liver biochemical parameters of 324 cases admitted with novel coronavirus pneumonia in Shanghai area. Methods: Clinical data and baseline liver biochemical parameters of 324 cases with novel coronavirus pneumonia admitted to the Shanghai Public Health Clinical Center from January 20, 2020 to February 24, 2020 were retrospectively analyzed. Patients were divided into two groups based on the status of illness: mild type (mild and typical) and severe type (severe and critical).The differences in clinical data and baseline liver biochemical parameters of the two groups were described and compared. The t-test and Wilcoxon rank-sum test were used for measurement data. The enumeration data were expressed by frequency and rate, and chi-square test was used. Results: Of the 324 cases with novel coronavirus pneumonia, 26 were severe cases (8%), with median onset of 5 days, 20 cases were HBsAg positive (6.2%), and 70 cases (21.6%) with fatty liver, diagnosed with X-ray computed tomography. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), γ-glutamyl transferase (GGT), total bilirubin (TBil), albumin(ALB) and international normalized ratio (INR) of 324 cases at baseline were 27.86 ± 20.02 U/L, 29.33 ± 21.02 U/L, 59.93 ± 18.96 U / L, 39.00 ± 54.44 U/L, 9.46 ± 4.58 μmol / L, 40.64 ± 4.13 g / L and 1.02 ± 0.10. Of which, ALT was > than the upper limit of normal (> ULN), accounting for 15.7% (51/324). ALT and AST > ULN, accounting for 10.5% (34/324). ALP > ULN, accounting for 1.2% (4/324). ALP and GGT > ULN, accounting for 0.9% (3/324). INR > ULN was lowest, accounting for 0.6% (2/324). There were no statistically significant differences (P > 0.05) in ALT [(21.5 vs. 26) U / L, P = 0.093], ALP [(57 vs.59) U/L, P = 0.674], and GGT [(24 vs.28) U/L, P = 0.101] between the severe group and the mild group. There were statistically significant differences in AST (23 U/L vs. 34 U/L, P < 0.01), TBil (10.75 vs. 8.05 μmol / L, P < 0.01), ALB (35.79 ± 4.75 vs. 41.07 ± 3.80 g/L, P < 0.01), and INR (1.00 vs. 1.04, P < 0.01). Conclusion: The baseline liver biochemical parameters of 324 cases with novel coronavirus pneumonia in Shanghai area was comparatively lower and the liverinjury degree was mild, and the bile duct cell damage was rare.

[Clinical characteristics of anomalous origin of the left coronary artery from the pulmonary artery in 91 children]

Objective: To explore the clinical manifestations, diagnosis, treatment and prognosis of anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) . Methods: A retrospective study identified 91 patients diagnosed with ALCAPA at Shanghai Children's Medical Center from March 2010 to August 2017. According to the left ventricular ejection fraction (LVEF) at the time of consultation, patients were divided into the cardiac insufficiency group (n=54) and the normal cardiac function group (n=37). Clinical features (age of onset, clinical performance, etc) and auxiliary examinations (electrocardiogram, echocardiography, etc) between the two groups were compared using a t-test and a Chi-square test. Prognostic factors were analyzed by an ordered logistic regression and a Pearson correlation coefficient. Results: (1) The age of diagnosis of patients in the cardiac insufficiency group who were usually misdiagnosed as cardiomyopathy was (10.0±2.6) months (20/54) , whereas the age of diagnosis of patients in the normal cardiac function group who were usually misdiagnosed as valvular diseases was (40.0±7.8) months (4/37). According to the pathophysiological mechanism, forty of the 54 (74%) patients in the cardiac insufficiency group were infantile type, and 78% patients (29/37) in the normal cardiac function group were adult type. (2) Preoperative electrocardiogram showed the deep Q wave in lead I occurred more frequently in the cardiac insufficiency group than in the normal cardiac function group (28/54 vs. 11/37, χ(2)=4.388, P=0.036). (3) Twenty patients died in the cardiac insufficiency group including 12 patients who died from postoperative cardiac pump failure and 8 children who did not undergo surgery due to poor prognosis and died from other reasons. There was no death in the normal cardiac function group. (4) Preoperative LVEF was the unique risk factor affecting prognosis (F=16.872, P=0.005). The preoperative LVEF was significantly lower than the postoperative LVEF ((37±11)% vs. (45±14)%, t=3.614, P=0.001) in the cardiac insufficiency group. During the follow-up period, 6 patients in the cardiac insufficiency group still presented with postoperative cardiac dysfunction, and the patients in the normal cardiac function group still had normal cardiac function. Conclusions: Preoperative LVEF was the unique risk factor affecting prognosis of ALCAPA. Patients with infantile type ALCAPA and preoperative cardiac insufficiency should receive long-term follow-up treatment.

γ-Aminobutyric Acid (GABA) Induced in Vitro Differentiation of Rat Pancreatic Ductal Stem Cells into Insulin-Secreting Islet-Like Cell Clusters

In vitro produced β-like cells can provide promising cell therapy for curing the epidemic of diabetes. In this context, we aimed to investigate the effects of different concentrations of γ-aminobutyric acid (GABA) on the differentiation of rat pancreatic ductal epithelial-like stem cells (PDESCs) into β-like cells. The PDESC line cells were cultured in the basal media (DMEM/F12 + 10% FBS + 1% penicillinstreptomycin) supplemented with 0 μM, 5 μM, 50 μM, 500 μM, and 5 mM of GABA for 28 days to induce their differentiation. The differentiated cells were detected by cell morphology, dithizone (DTZ) staining, immunofluorescence staining, real-time polymerase chain reaction (qPCR), and glucose-stimulated insulin secretion (GSIS) assay to validate their identity. At the end of 28 days, compared with the control group, enrichment of induced cells was high among the 5 μM, 50 μM, 500 μM, and 5 mM GABA induction groups. The formation of islet-like cell clusters (ICCs) began at 14 days, and the cell clusters showed a growth trend with the culture time. The induced ICCs were positive for DTZ staining, while the control group showed negative results for DTZ staining and the differentiated cells were also positive for β-cell-specific markers (Ins1 and Pdx1). GSIS assay of 50 μM induction group cells at 28 days showed significantly higher levels of C-peptide and insulin secretion than the control, 5 μM, 500 μM, and 5 mM GABA-treated groups (P < 0.01). At the same time, the 50 μM induction group cells also showed significantly higher levels of Ins1, Pdx1 and Nkx6.1 mRNA as compared to the 5 μM, 500 μM and 5 mM GABA groups (P < 0.01). Thus, the addition of GABA to the basal medium effectively induced differentiation of adult rat PDESCs into insulin-secreting β-like cells, and 50 μM was the most effective concentration for the induction.

EFFECT OF DORSOMEDIAL HYPOTHALAMUS NEUROPEPTIDE Y KNOCKDOWN ON HEPATIC INSULIN SENSITIVITY

Objective

In this study we investigated the effect of dorsomedial hypothalamus (DMH) neuropeptide Y (NPY) knock-down on hepatic insulin sensitivity in high-fat (HF) diet-fed rats.

Methods

Forty-eight Sprague-Dawley rats were randomly assigned to receive bilateral DMH injections of adeno-associated virus AAVshNPY or AAVshCTL and then accessed to regular chow. Five weeks after viral injection, half rats in each group were given access to the HF diet. At 16 weeks, rat livers were collected. Insulin receptor substrate-1 (IRS-1) and phosphoinositide 3-kinase (PI3K) mRNA expression was measured by qRT-PCR. Blood glucose levels were measured by the oxidase method, serum insulin, triglyceride, and TC levels were measured by Elisa. Pathological changes in the liver were assessed by hematoxylin-eosin (HE) staining. AKT, p-AKT, and GSK-3 levels were measured by western blotting.

Results

Compared with AAVshCTL-injected rats, AAVshNPY-injected rats showed a significant decrease in blood glucose concentrations; serum insulin, triglyceride, and TC; HOMA-IR; and IRS-1 and PI3K mRNA levels (P<0.05). ISI, GSK-3, and p-AKT levels were significantly increased (P<0.05). HE staining showed that AAVshNPY-injected rats fed the HF diet had mild fatty degeneration.

Conclusion

These results suggest that DMH NPY knock-down improves hepatic insulin sensitivity in HF diet-fed rats by activating the hepatic PI3K/AKT insulin signalling pathway.

Probiotic Bacillus enhance the intestinal epithelial cell barrier and immune function of piglets

Bacillus is widely used in the livestock industry. This study was designed to evaluate the effects of probiotic Bacillus amyloliquefaciens SC06 (Ba), originally isolated from soil, in piglets diet as an alternative to antibiotics (aureomycin), mainly on intestinal epithelial barrier and immune function. Ninety piglets were divided into three groups: G1 (containing 150 mg/kg aureomycin in the diet); G2 (containing 75 mg/kg aureomycin and 1×108 cfu/kg Ba in the diet); G3 (containing 2×108 cfu/kg Ba in the diet without any antibiotics). The results showed that, compared with the antibiotic group (G1), villus length, crypt depth and villus length/crypt depth ratio of intestine significantly increased in the G2 and G3 groups. In addition, intestinal villi morphology, goblet-cell number, mitochondria structure and tight junction proteins of intestinal epithelial cells in G2 and G3 were better than in G1. The relative gene expression of intestinal mucosal defensin-1, claudin3, claudin4, and human mucin-1 in G3 was significantly lower, while the expression of villin was significantly higher than in the antibiotic group. Probiotic Ba could significantly decrease serum interferon (IFN)-α, IFN-γ, interleukin (IL)-1β, and IL-4 levels, whereas increase tumour necrosis factor (TNF)-α and IL-6 secretion. Ba could also significantly decrease cytokines TNF-α, IFN-γ, IL-1β, and IL-4 level in liver, whereas it significantly increased IFN-α. Furthermore, replacing antibiotics with Ba also significantly down-regulated gene expression of TNF and IL-1α in intestinal mucosa, but up-regulated IL-6 and IL-8 transcription. Dietary addition of Ba could significantly reduce the gene expression of nuclear factor kappa beta (NFκB)-p50 and Toll-like receptor (TLR)6, while there was no significant difference for that of myeloid differentiation primary response 88, TNF receptor-associated factor-6, nucleotide-binding oligomerisation domain-containing protein 1, TLR2, TLR4, and TLR9. Taken together, our findings demonstrated that probiotic Ba could increase the intestinal epithelial cell barrier and immune function by improving intestinal mucosa structure, tight junctions and by activating the TLRs signalling pathway.

[The impact of genetic variation of KDR on clinical outcomes of advanced colorectal cancer patients treated by first line bevacizumab based regimens]

Objective: To investigate the association between kinase insertion region receptor (KDR) gene genetic variation and the efficacy of bevacizumab in patients with advanced colorectal cancer(CRC) were investigated in this study. Methods: 118 patients with advanced colorectal cancer who were treated by bevacizumab based first line regimens were included in this study. Peripheral blood and the biopsy tissue specimens of the CRC patients were collected for the genotyping of genetic variation and KDR gene expression, respectively. The univariate analysis of genotypes and prognosis was carried out by Kaplan-Meier survival analysis, and multivariate were adjusted by Cox regression analysis. Results: Located in the coding region, the prevalence of 889 C>T in KDR among the study population were as follows: CC genotype 86 cases (72.88%), CT genotype 30 cases (25.42%), TT genotype 2 cases (1.70%), minor allele frequency of 889 C>T is 0.14. The distribution of three genotypes in accordance with Hardy-Weinberg Equilibrium (P=0.737). There were no statistical differences in the distribution of the genotypes in baseline clinical data. TT and CT genotype patients were merged in the comparison of clinical outcomes. The clinical outcomes analysis of patients with different genotypes found that the objective response rates (ORR) of CT/TT genotypes were 34.38% and 43.02% (P=0.395), respectively. And the median progression free survival (PFS) of patients with CT/TT genotype and CC genotype were 7.5 and 9.7 months respectively, which was statistically significant (P=0.009). In terms of overall survival (OS), the median OS of the two genotypes were 19.3 and 20.1 (P=0.025), respectively. Adjusted in multivariate Cox regression analysis of PFS, CT/TT genotypes were an independent factor for PFS (OR=1.88, P=0.023). Additionally, of the 57 biopsy tissue specimens, gene expression analysis was conducted. And the results showed that the expression of KDR in cancer tissues of the patients with CT/TT genotypes were significantly higher than those of the CC genotype patients (P<0.001). Conclusion: Among advanced colorectal cancer patients treated by bevacizumab, the polymorphism 889 C>T of KDR may impact the clinical outcomes of bevacizumab first line treatment by influencing the mRNA expression of KDR.

Fast coarse-fine locating method for φ-OTDR

We proposed and demonstrated a coarse-fine method to achieve fast locating of external vibration for the phase-sensitive optical time-domain reflectometer (φ-OTDR) sensing system. Firstly, the acquired backscattered traces from heterodyne coherent φ-OTDR systems are spatially divided into a few segments along a sensing fiber for coarse locating, and most of the acquired data can be excluded by comparing the phase difference between the endpoints in adjacent segments. Secondly, the amplitude-based locating is implemented within the target segments for fine locating. By using the proposed coarse-fine locating method, we have numerically and experimentally investigated a distributed vibration sensor based on the heterodyne coherent φ-OTDR system with a 50-km-long sensing fiber. We find that the computation cost of signal processing for locating is significantly reduced in the long-haul sensing fiber, showing a potential application in real-time locating of external vibration.

Microfluidic co-culture platform for investigating osteocyte-osteoclast signalling during fluid shear stress mechanostimulation

Bone cells exist in a complex environment where they are constantly exposed to numerous dynamic biochemical and mechanical stimuli. These stimuli regulate bone cells that are involved in various bone disorders, such as osteoporosis. Knowledge of how these stimuli affect bone cells have been utilised to develop various treatments, such as pharmaceuticals, hormone therapy, and exercise. To investigate the role that bone loading has on these disorders in vitro, bone cell mechanotransduction studies are typically performed using parallel plate flow chambers (PPFC). However, these chambers do not allow for dynamic cellular interactions among different cell populations to be investigated. We present a microfluidic approach that exposes different cell populations, which are located at physiologically relevant distances within adjacent channels, to different levels of fluid shear stress, and promotes cell-cell communication between the different channels. We employed this microfluidic system to assess mechanically regulated osteocyte-osteoclast communication. Osteoclast precursors (RAW264.7 cells) responded to cytokine gradients (e.g., RANKL, OPG, PGE-2) developed by both mechanically stimulated (fOCY) and unstimulated (nOCY) osteocyte-like MLO-Y4 cells simultaneously. Specifically, we observed increased osteoclast precursor cell densities and osteoclast differentiation towards nOCY. We also used this system to show an increased mechanoresponse of osteocytes when in co-culture with osteoclasts. We envision broad applicability of the presented approach for microfluidic perfusion co-culture of multiple cell types in the presence of fluid flow stimulation, and as a tool to investigate osteocyte mechanotransduction, as well as bone metastasis extravasation. This system could also be applied to any multi-cell population cross-talk studies that are typically performed using PPFCs (e.g. endothelial cells, smooth muscle cells, and fibroblasts).