Proteins are fundamental carriers as the structural elements and biochemically active entities responsible for catalysis, transport, and regulation. These functions are depending on the protein folding into precise three-dimensional structures, interacting with ligands, and conformational changes. This article reviews the recent progress of nanopores in single-molecule protein sensing, involving the identification of polypeptides and proteins, the conformation changes of protein folding, the molecular structure responsible to the pH of solutions, the molecular interactions, and protein sequencing. These studies provide clues to understand life activities and facilitate the early diagnosis of diseases and design of drugs for precise treatment.
Nanopores ; Proteins/chemistry* ; Biosensing Techniques/methods* ; Protein Folding ; Humans

Cucumber (Cucumis sativus L.) is one of the most widely cultivated vegetables in the world. High temperature and other stress conditions can affect the growth and development of this plant, even leading to the decreases in yield and quality. The mitogen-activated protein kinase (MAPK) family plays a crucial role in plant stress responses. However, the role of MPK4 in the stress response of cucumber remains to be reported. In this study, we cloned CsMPK4, which encoded 383 amino acid residues. The qRT-PCR results showed that the expression level of CsMPK4 was the highest in leaves and flowers, moderate in roots, and the lowest in stems and tendrils. CsMPK4 was located in the nucleus and cytoplasm, and it had a close relationship with CmMPK4 in muskmelon. The cucumber plants overexpressing CsMPK4 became stronger and shorter, with reduced length and quantity of tendrils. Moreover, the transgenic seedlings were more resistant to high temperatures, with decreased malondialdehyde (MDA) content and increased activities of peroxidase (POD) and superoxide dismutase (SOD) in young leaves. Furthermore, the protein-protein interaction between CsMPK4 and CsVQ10, a member of the valine-glutamine family, was confirmed by yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assays. The results suggested that CsVQ10 cooperated with CsMPK4 in response to the high temperature stress in cucumber. This study laid a foundation for the further study on the stress response mechanism of CsMPK4 and the breeding of stress-resistant cucumber varieties.
Cucumis sativus/metabolism* ; Mitogen-Activated Protein Kinases/physiology* ; Plant Proteins/metabolism* ; Plants, Genetically Modified/metabolism* ; Gene Expression Regulation, Plant ; Stress, Physiological/genetics* ; Cloning, Molecular

Objective To investigate the expression of the ubiquitination enzyme UBE2S in different cell types in hepatocellular carcinoma(HCC)microenvironment and its impact on proliferation and stemness of HCC cells.Methods TCGA and CPTAC database were used to analyze the transcriptional and promoter methylation levels and protein expressions of UBE2S in HCC.Specific expression patterns of UBE2S,intercellular communication and key transcription factors in different cell types were analyzed based on single-cell sequencing data from TISCH website.We further examined UBE2S expressions in clinical samples of HCC tissues,HCC cells and T cells using immunohistochemistry and immunofluorescence staining.We also tested the effects of UBE2S knockdown on stemness of HCC-LM3 and HepG2 cells using clone formation experiments and sphere formation assay.Results Analysis based on TCGA database suggested significant overexpression of UBE2S in both paired and non-paired tumor tissues(P<0.001),and its transcriptional level increased with tumor grades.The methylation level of UBE2S promoter was significantly decreased in HCC(P<0.001),and its transcription level increased obviously in HCC with TP53 mutation(P<0.001).Analysis of CPTAC database also demonstrated overexpression of UBE2S protein in HCC tissues(P<0.001).Three prognostic models suggested that HCC patients with high UBE2S expression had poorer prognosis(P<0.001).Single-cell sequencing data analysis revealed high expressions of UBE2S in T cells and high intensities of interaction between endothelial cells,epithelial cells and fibroblasts in HCC microenvironment.Immunohistochemistry and immunofluorescence staining demonstrated high UBE2S expressions in clinical samples of HCC tissues,HCC cells and T cells.In HCC-LM3 and HepG2 cells,UBE2S knockdown significantly inhibited cell clone formation and tumor sphere formation(P<0.05).Conclusion UBE2S is highly expressed in T cells in HCC microenvironment in close correlation with a poor prognosis.High UBE2S expression promotes the stemness of HCC cells.

Objective To investigate the expression of the ubiquitination enzyme UBE2S in different cell types in hepatocellular carcinoma(HCC)microenvironment and its impact on proliferation and stemness of HCC cells.Methods TCGA and CPTAC database were used to analyze the transcriptional and promoter methylation levels and protein expressions of UBE2S in HCC.Specific expression patterns of UBE2S,intercellular communication and key transcription factors in different cell types were analyzed based on single-cell sequencing data from TISCH website.We further examined UBE2S expressions in clinical samples of HCC tissues,HCC cells and T cells using immunohistochemistry and immunofluorescence staining.We also tested the effects of UBE2S knockdown on stemness of HCC-LM3 and HepG2 cells using clone formation experiments and sphere formation assay.Results Analysis based on TCGA database suggested significant overexpression of UBE2S in both paired and non-paired tumor tissues(P<0.001),and its transcriptional level increased with tumor grades.The methylation level of UBE2S promoter was significantly decreased in HCC(P<0.001),and its transcription level increased obviously in HCC with TP53 mutation(P<0.001).Analysis of CPTAC database also demonstrated overexpression of UBE2S protein in HCC tissues(P<0.001).Three prognostic models suggested that HCC patients with high UBE2S expression had poorer prognosis(P<0.001).Single-cell sequencing data analysis revealed high expressions of UBE2S in T cells and high intensities of interaction between endothelial cells,epithelial cells and fibroblasts in HCC microenvironment.Immunohistochemistry and immunofluorescence staining demonstrated high UBE2S expressions in clinical samples of HCC tissues,HCC cells and T cells.In HCC-LM3 and HepG2 cells,UBE2S knockdown significantly inhibited cell clone formation and tumor sphere formation(P<0.05).Conclusion UBE2S is highly expressed in T cells in HCC microenvironment in close correlation with a poor prognosis.High UBE2S expression promotes the stemness of HCC cells.

OBJECTIVE：To study the improvement effect and mechanism of MEBO on lipopolysaccharide （LPS）-induced injury of rat skin fibroblasts. METHODS ：Skin fibroblasts of rats were divided into control group ，LPS group （5 μg/mL）， Kangfuxin solution group （positive control ，5 μg/mL LPS+1.25％ Kangfuxin solution ）and MEBO group （5 μg/mL LPS+0.6 mg/mL MEBO），with 6 wells in each group. Inflammatory injury cell model was induced by LPS （except for control group ）. After a certain period of cultivation ，the cell survival rate and cell migration rate were detected in each group. The contents of TNF-α and IL-6 in cell supernatant was detected. The localization and fluorescence intensity of IL- 6 protein were detected. The protein expression of PTEN ，p-p65，TNF-α，IL-6，PI3K and Akt in the fibroblasts were also determined. RESULTS ：Compared with control group ，survival rate of the fibroblasts was increased significantly in LPS group ，while cell migration was decreased significantly；the contents of TNF-α and IL-6 in cell supernatant as well as relative protein expression of PTEN ，p-p65，TNF-α， IL-6 and PI 3K were increased significantly （P＜0.05 or P＜0.01）；IL-6 protein mainly expressed in the cytoplasm ，and the fluorescence intensity was enhanced. Compared with LPS group ，survival rate of the fibroblasts was decreased significantly in Kangfuxin solution group and MEBO group ，while migration rate was increased significantly ；the contents of TNF-α and IL-6， relative protein expression of PTEN ，p-p65，TNF-α，IL-6（except for Kangfuxin solution group ），PI3K and Akt （except for Kangfuxin solution group ） were decreased significantly （P＜0.05 or P＜0.01），while fluorescence intensity of IL- 6 protein decreased；relative protein expression of TNF-α，IL-6，PI3K and Akt in MEBO group were significantly lower than Kangfuxin solution group （P＜0.05 or P＜0.01）. CONCLUSIONS ：MEBO can inhibit the proliferation of LPS-induced skin fibroblasts ， reduce the level of inflammatory factors and the intensity of inflammatory reaction ， which may be related to the jiang- down-regulation of PTEN/NF-κB，PI3K/Akt signaling pathway.

Objective:To study the feasibility and safety in treatment of trauma to right posterior liver using laparoscopic surgery with patients in the left semiprone position.Methods:The clinical data of consecutive patients who were diagnosed to have trauma to the right posterior liver and were treated with laparoscopic surgery with patients in the left semiprone position at the Department of Hepatobiliary Surgery, the Affiliated Hospital of Youjiang Medical University for Nationalities between February 2016 and August 2020 were retrospectively analysed. The patients’ gender, age, mechanisms of injury, operative methods, operative time, amounts of abdominal effusion, degrees of liver injury, extents of intraoperative bleeding, amounts of postoperative drainage, lengths of postoperative hospital stay, and major postoperative complications were recorded and analyzed.Results:Among the 18 patients, there were 16 males and 2 females, aged (41.6±14.4) years. The mechanisms of liver trauma were caused by fall injury ( n=10), traffic accidents ( n=4), blunt injury ( n=2) and penetrating injury ( n=2). The levels of injuries were level Ⅲ in 16 patients and level Ⅳ in 2 patients. Laparoscopic suture repair was performed in 8 patients, partial hepatectomy in 4 patients, electrocoagulation hemostasis in 4 patients and ligation of bleeding vessels in 2 patients. All were successful in hemostasis. Abdominal effusion was (1 528.8±373.2) ml, intraoperative blood loss (80.6±16.7) ml, operation time (88.5±9.1) min, postoperative hospital stay 7 days and postoperative total drainage (93.8±13.6) ml. Ten patients were complicated with right pleural effusion, and they recovered with conservative treatment. There were no bile leakage, infection and other complications. Conclusion:Trauma to right posterior liver treated with laparoscopic with surgery patients in the left semiprone position had the advantages of adequate exposure which facilitated surgical hemostasis, resulting in minimal collateral damages and short hospital stay. The treatment was feasibility and safe.

OBJECTIVE: To investigate the effect of curcumin on the invasion and migration of human glioma cells and explore the molecular mechanisms. METHODS: MTT assay was used for screening the optimal curcumin concentrations. The effects of curcumin on the invasion and metastasis of human glioma cell lines U251 and LN229 were tested using Transwell assay, Boyden assay and wound-healing assays. The expression of the related proteins and their interactions were determined using Western blotting and coimmunoprecipitation assay. RESULTS: Curcumin at the concentration of 20 μmol/L for 48 h was used as the optimal condition for subsequent cell treatment. In the two glioma cell lines, curcumin significantly suppressed the invasion and migration of the cells ( < 0.05) and lowered the expressions of hepatoma-derived growth factor (HDGF), Ncadherin, vimentin, Snail and Slug, but increased the expression of E-cadherin. Interference of HDGF in curcumin-treated glioma cells synergistically inhibited the epithelial-mesenchymal transition (EMT) signals, while overexpression of HDGF significantly reversed the inhibitory effect of curcumin on EMT; curcumin treatment could significantly reduce the binding of HDGF to β-catenin. CONCLUSIONS Curcumin suppresses EMT signal by reducing HDGF/β-catenin complex and thereby lowers the migration and invasion abilities of human glioma cells .
Cell Line, Tumor ; Cell Movement ; Curcumin ; Epithelial-Mesenchymal Transition ; Glioma ; Humans ; Intercellular Signaling Peptides and Proteins ; Neoplasm Invasiveness ; beta Catenin

Objective To investigate the effects and mechanism of interleukin 33 (IL-33) on renal tubular injury in mice with lupus nephritis.Methods Twelve-week-old female MRL/lpr mice were randomly divided into model group,IL-33 group and solvent control group with 10 rats in each group.Ten female MRL/MP mice of the same age were used as normal control group.The mice in IL-33 group were intraperitoneally injected with 100 μL of phosphate buffer saline (PBS),containing 2 μg of recombinant mouse IL-33,once a day for 14 days.The mice in control group and the model group were intraperitoneally injected with the same dose of PBS.All the mice were sacrificed at 14 weeks of age.Serum creatinine (Cr) and urea nitrogen (BUN) concentrations were determined by serum separation.The urine in 24 hours was collected testing urinary protein creatinine ratio and urinary protein quantification.The contents of E-cadherin,α-SMA,and JAK/STAT pathway signaling proteins,including JAK2,p-JAK2,STAT1,and p-STAT1,were detected by Western blot.Results The BUN,urinary protein creatinine ratio and urine protein level of the IL-33 group were significantly higher than those of the model group (all P＜0.05).The expression of renal tubular epithelial cells o-SMA in the IL-33 group was higher than that in the model group,and the difference was statistically significant (P＜0.05).Compared with the model group,the expression of E-cadherin in the tubular epithelial cells of IL-33 group decreased and the expression of p-JAK2 and p-STAT1 protein increased,and the differences were all statistically significant (all P＜0.05).Compared with the model group,the levels of JAK2 and STAT1 in IL-33 group change little,and the differences were not statistically significant (all P＞0.05).Conclusions IL-33 can cause tubulointerstitial lesions in lupus mice,and its mechanism may be related to the activation of JAK/STAT pathway.

Objective To explore the mechanism of Dahuanglinxian Capsule for intervening gallstone formation by regulating the expression levels of ABCB11 and ABCC2 mRNA and protein.Methods Forty male C57BL/6 mice were divided into the normal group(group N),model group (group M),ursodeoxycholic acid group (group U) and Dahuanglinxian Capsule treatment group (group D),10 cases in each group.The group N was fed with normal diet,while the group M,U and D were fed with lithogenic fodder for 8 weeks.Meanwhile the group U and D were given the medication intervention,once daily,for continuous 8 weeks of gavage.After successful modeling,mRNA and protein expression levels of ABCB11 and ABCC2 were detected by RT-PCR and immunohistochemistry.Results Compared with the other three groups,the expressions of ABCB11 and ABCC2 mRNA gene and protein in M group were significantly reduced(P＜0.01);while,there was no statistical difference in the expressions of ABCB11 and ABCC2 mRNA and protein between the group D and N(P＞0.05).Conclusion Dahuanglinxian Capsule can prevent the gallstone formation by regulating the expression of ABCB11 and ABCC2 mRNA and protein.