BACKGROUND:Eucommia ulmoides has a certain osteogenic effect,which can promote the proliferation and differentiation of osteoblasts.However,it is unclear whether Eucommia ulmoides has effects on alveolar bone formation and Wnt/β-Catenin signaling pathway. OBJECTIVE:To investigate the mechanism by which Eucommia ulmoides promotes alveolar bone formation in ovariectomized rats based on the Wnt/β-Catenin signaling pathway. METHODS:Sixty female Sprague-Dawley rats were selected and randomly divided into five groups:blank control group,sham-operation group,model group,low-dose group Eucommia ulmoides group,and high-dose Eucommia ulmoides group,with twelve rats in each group.Osteoporosis animal models were constructed by bilateral oophorectomy in the model group and the low-dose and high-dose Eucommia ulmoides groups.The sham-operation group underwent the same method to remove adipose tissue of equal mass around the bilateral ovaries.Three months after surgery,the low-and high-dose Eucommia ulmoides groups were given 2.1 g/kg/d and 4.2 g/kg/d Eucommia ulmoides by gavage,respectively.The sham-operation group and model group were given the same amount of physiological saline by gavage.After 12 weeks of drug intervention,the changes in alveolar bone mass of rats in each group were observed through Micro-CT;hematoxylin-eosin staining was used to observe the pathological structural changes of alveolar bone in rats;enzyme linked immunosorbent assay was used to detect the expression levels of alkaline phosphatase and osteocalcin in the serum of rats;western blot was used to detect the expression levels of β-Catenin and Frizzled9 receptor proteins in the alveolar bone of rats;and real-time fluorescence quantitative PCR was used to detect the expression of osteocalcin,Runt-related transcription factor 2(Runx2),alkaline phosphatase,β-catenin,and frizzled9 mRNAs in alveolar bone tissues of rats. RESULTS AND CONCLUSION:Compared with the blank control group,bone volume fraction,trabecular number,trabecular thickness,and bone mineral density were reduced in the model group(P＜0.05),and trabecular separation was elevated(P＜0.05).Pathological observation showed that the arrangement of trabeculae was disordered and irregular,the trabeculae were thinned or broken,and the marrow cavity was enlarged in the model group,with a significant reduction in bone volume;the level of alkaline phosphatase in the serum was increased(P＜0.05),and the level of osteocalcin was decreased(P＜0.05);mRNA expression of alkaline phosphatase,osteocalcin,Runx2,β-catenin,and frizzled9 were decreased(P＜0.05);protein expression of β-Catenin and Frizzled9 was decreased(P＜0.05).Compared with the model group,the low-and high-dose Eucommia ulmoides groups showed an increase in bone volume fraction,trabecular number,trabecular thickness,and bone mineral density(P＜0.05)and a decrease in trabecular separation(P＜0.05).In the low-and high-dose Eucommia ulmoides groups,bone trabeculae were slightly aligned and thickened,with a significant increase in bone mass.Compared with the model group,the serum level of alkaline phosphatase was reduced(P＜0.05)and the serum level of osteocalcin was elevated(P＜0.05)in the low-and high-dose Eucommia ulmoides groups.Compared with the model group,the mRNA expression of alkaline phosphatase,osteocalcin,Runx2,β-catenin,and frizzled9 were increased in the low-and high-dose Eucommia ulmoides groups(P＜0.05).Compared with the model group,the protein expression of Frizzled9 was increased in the low-dose Eucommia ulmoides group(P＜0.05),while the protein expression of β-Catenin and Frizzled9 was increased in the high-dose Eucommia ulmoides group(P＜0.05).Compared with the low-dose Eucommia ulmoides group,the high-dose Eucommia ulmoides group had a more significant improvement in the above indexes.To conclude,Eucommia ulmoides can effectively promote the alveolar bone formation,and its mechanism of action might be related to the activation of the Wnt/β-catenin signaling pathway.

Objective:To construct a microfluidic organ-on-a-chip and evaluate its capability in simulating subchondral bone remodeling during the progression of osteoarthritis.Methods:The chip′s main body was designed based on the microfluidic technology and cell co-culture technique. MC3T3-E1 cells were cultured adherently within the cell seeding micro-chamber, with the culture medium perfused at a flow rate of 0.5 ml/min at the bottom of the micro-chamber. Evaluation metrics were as follows: (1) Assessment of the microfluidic organ-on-a-chip: The growth culture medium was perfused and simulation experiments were conducted to test the concentration differences and equilibrium times of the fluid inside and at the bottom of the cell seeding micro-chamber at various time points; live-dead staining was performed to observe the biocompatibility of cells cultured continuously for 3 days and 7 days at a set flow rate, which was divided into 3-day and 7-day groups. (2) Osteogenic potential of the microfluidic organ-on-a-chip: The osteogenic induction medium was perfused, and ALP staining and PCR were performed to compare the number of the black alkaline phosphatase (ALP)-positive cells and the expression levels of osteogenesis-related marker genes including osteoblast-specific transcription factor 2 (RUNX2), type I collagen (COL1A1), bone morphogenetic protein-2 (BMP-2), and osteocalcin (OCN) under static, 3-day and 7-day perfusion conditions, which was divided into static non-induced, static-induced and perfusion-induced groups. (3) Characterization of morphology and size, and biocompatibility of extracellular vesicles (EVs) of three osteoblast subtypes: Three different subtypes of osteoblasts were obtained [endothelial-type osteoblasts (EnOB)-EVs, stromal-type osteoblasts (StOB)-EVs and mineralizing-type osteoblasts (MinOB)-EVs]. Their morphology and size were obtained through transmission electron microscopy and particle size analysis. Growth medium containing EVs of three different cell subtypes was perfused, and cell proliferation/apoptosis assay was performed to compare the biocompatibility of the addition of different EVs concentrations (1, 1.25, 2.5, and 5 μg/ml) for 24 hours, which was categorized into the EnOB-EVs group, StOB-EVs group and MinOB-EVs group. (4) Osteogenic effect of EVs from three subtypes of osteoblasts: Osteogenic induction media containing EVs from three different osteoblast subtypes were perfused for 3 days, and ALP staining and PCR were performed to compare the number of black ALP-positive cells and the expression levels of osteogenesis-related marker genes including RUNX2, COL1A1, BMP-2, and OCN, which was divided into non-EVs group, EnOB-EVs group, StOB-EVs group and MinOB-EVs group.Results:(1) Evaluation of the microfluidic organ-on-a-chip: Simulation results showed that the concentration in the top layer of the upper chamber reached more than 95% of that in the lower chamber and that the concentration in the bottom layer was about 96.5% of that in the lower chamber after 12 hours of continuous perfusion, reaching an equilibrium state of the concentration difference between the upper and lower chambers. The results of live-dead staining showed that the chip was biocompatible at a flow rate of 0.5 ml/min, and the cell survival rate at 3 and 7 days of perfusion was (99.48±0.12)% and (97.07±1.05)% ( P<0.01). (2) ALP staining results showed that at 3 days, the perfusion-induced group showed the highest number of black ALP-positive cells, followed by the static-induced group, and the least in the static non-induced group. At 7 days, the static-induced group had the highest number of black ALP-positive cells, followed by the perfusion-induced group, and the least in the static non-induced group. PCR results indicated that at 3 days, the expression levels of RUNX2, COL1A1, BMP-2, and OCN were 1.00±0.03, 1.00±0.12, 1.00±0.01, and 1.00±0.02 respectively in the static non-induced group; 1.80±0.04, 4.05±0.37, 9.80±1.94, and 4.38±0.89 respectively in the static-induced group, and 2.45±0.23, 5.48±0.42, 91.50±4.56, and 10.82±4.96 respectively in the perfusion-induced group ( P<0.01). At 7 days, the expression levels of RUNX2 was 1.00±0.01 in the static non-induced group, 1.46±0.46 in the static-induced group, and 1.11±0.08 in the perfusion-induced group ( P>0.05); the expression levels of COL1A1, BMP-2, and OCN were 1.00±0.03, 1.00±0.13, and 1.00±0.09 respectively in the static non-induced group, 9.38±0.25, 14.27±4.35, and 84.01±4.02 respectviely in the static-induced group, and 2.39±0.08, 133.64±8.87, and 86.64±8.36 respectively in the perfusion-induced group ( P<0.01). When comparing the static non-induced, static-induced, and perfusion-induced groups at both 3 and 7 days, the perfusion-induced group demonstrated the strongest osteogenic capability. (3) Characterization of morphology and size and biocompatibility of EVs from three osteoblast subtypes: Under the transmission electron microscope, EVs from EnOB-EVs, StOB-EVs, and MinOB-EVs all exhibited a typical saucer-shaped morphology. The particle sizes of EnOB-EVs, StOB-EVs, and MinOB-EVs were (91.3±14.7)nm, (106.0±16.0)nm, and (68.1±10.7)nm, respectively. Cell proliferation/apoptosis assay results indicated that the optimal administration concentration of EnOB-EVs, StOB-EVs, and MinOB-EVs was all 1.25 μg/mL. (4) Validation of osteogenic effect of the microfluidic organ-on-a-chip on three types of EVs: ALP staining results showed that the non-EVs group had the fewest black ALP-positive cells, followed by the EnOB-EVs group, then the StOB-EVs group, and the MinOB-EVs group had the most. PCR results showed that the expression levels of RUNX2, COL1A1, BMP-2, and OCN were 1.00±0.01, 1.00±0.03, 1.00±0.02, and 1.00±0.02 respectively in the non-EVs group, 1.95±0.11, 6.78±2.04, 7.99±0.57, and 6.93±3.83 repectively in the EnOB-EVs group, 0.79±0.12, 5.68±1.53, 12.59±3.15, and 25.59±0.95 respectively in the StOB-EVs group, and 0.68±0.10, 4.36±0.69, 18.75±3.21, and 34.74±3.98 repectively in the MinOB-EVs group ( P<0.01). Compared with the non-EVs group, EnOB-EVs group, StOB-EVs group, and MinOB-EVs group, the MinOB-EVs group showed the most significant osteogenic effect. Conclusions:The microfluidic organ-on-a-chip constructed using microfluidic technology and cell co-culture techniques is capable of maintaining the normal growth of MC3T3-E1 cells, enhancing their proliferation and osteogenic induction differentiation. EVs released by osteoblasts at different stages possess osteogenic effects and can accelerate the bone sclerosis in the remodeling of subchondral bone during the progression of osteoarthritis.

Objective:To investigate the role of protein phosphatase 4 catalytic subunit (PP4C) in regulating hepatitis B virus X protein (HBx) levels and its effects on the biological functions of HBx, thus to provide a potential therapeutic targets for hepatitis B virus (HBV)-related hepatocellular carcinoma.Methods:In vivo and in vitro interactions between HBx and PP4C were analyzed by co-immunoprecipitation (Co-IP) and GST pull-down assay. Recombinant plasmids of PP4C and HBx were co-transfected with Lipofectamine 3000 reagents into hepatoma cells to detect the protein levels of HBx by Western blot. The half-life of HBx in the transfected cells treated with cycloheximide (CHX) were detected. The phosphorylation assay was used to evaluate the effects of PP4C on HBx phosphorylation. CCK8 assay, wound healing assay and Matrigel invasion chamber assay were used to analyze the effects of PP4C on the biological functions of HBx. Results:PP4C interacted with HBx in vivo and in vitro. PP4C overexpression significantly increased the protein level and stability of HBx and the phosphorylation assay confirmed that PP4C overexpression decreased the serine phosphorylation of HBx in hepatoma cells. PP4C overexpression enhanced the migration and invasion of hepatoma cells, but had no significant effects on the proliferation. Conclusions:The interactions between HBx and PP4C promoted the stability of HBx and ultimately enhanced the migration and invasion of hepatoma cells, and the mechanisms might be related to the decrease of HBx serine phosphorylation by PP4C. This study provided a theoretical basis for further investigation of the pathogenic mechanisms of HBx, and targeting PP4C and HBx interaction might provide insights for developing novel treatment for HBV-related hepatocellular carcinoma.

Molecular knowledge of human gastric corpus epithelium remains incomplete. Here, by integrated analyses using single-cell RNA sequencing (scRNA-seq), spatial transcriptomics, and single-cell assay for transposase accessible chromatin sequencing (scATAC-seq) techniques, we uncovered the spatially resolved expression landscape and gene-regulatory network of human gastric corpus epithelium. Specifically, we identified a stem/progenitor cell population in the isthmus of human gastric corpus, where EGF and WNT signaling pathways were activated. Meanwhile, LGR4, but not LGR5, was responsible for the activation of WNT signaling pathway. Importantly, FABP5 and NME1 were identified and validated as crucial for both normal gastric stem/progenitor cells and gastric cancer cells. Finally, we explored the epigenetic regulation of critical genes for gastric corpus epithelium at chromatin state level, and identified several important cell-type-specific transcription factors. In summary, our work provides novel insights to systematically understand the cellular diversity and homeostasis of human gastric corpus epithelium in vivo.
Humans ; Epigenesis, Genetic ; Gastric Mucosa/metabolism* ; Chromatin/metabolism* ; Stem Cells ; Epithelium/metabolism* ; Fatty Acid-Binding Proteins/metabolism*

Objective:To explore the influence of chronic rhinitis on depressive symptoms of college freshmen and the mediating effect of avoidant personality.Methods:A cluster sampling method was used to survey 8 079 college freshmen from April 2018 to October 2018 using the Beck depression inventory and the avoidant personality diagnosis questionnaire based on DSM-Ⅳ.SPSS 25.0 software was used for descriptive statistics and Spearman correlation analysis, and the macro program PROCESS version 3.3 was used for the mediating effect.Results:(1) The detection rates of chronic rhinitis, avoidant personality and depressive symptoms were 22.90% (1 850/8 079), 19.22% (1 553/8 079) and 6.28% (507/8 079). The scores for avoidant personality disorder and depressive symptoms were 1.00 (0, 3.00) and 1.00 (0, 4.00), respectively. (2) The chronic rhinitis, avoidant personality and depressive symptoms were positively correlated ( rchronic rhinitis-avoidant personality=0.094, rchronic rhinitis-depressive symptoms=0.095, ravoidant personality-depressive symptoms=0.416, all P<0.001). (3) Chronic rhinitis could positively predict depressive symptoms ( β=1.113, P<0.001). (4) Avoidant personality played a mediating role between chronic rhinitis and depressive symptoms ( β=1.094, P<0.001), and accounted for 44.92%(0.500/1.113) of the total effect. Conclusion:Chronic rhinitis directly affect the depressive symptoms of college freshmen, and indirectly affect the depressive symptoms of college freshmen through the mediating role of avoidant personality.

Objective:To investigate the risk factors of anemia and prognostic value of different grades of anemia in patients with hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF).Methods:Anemia grades of 1 163 patients with HBV-ACLF were analyzed and the effect of different grades on prognosis were evaluated. The risk factors related to anemia were evaluated by Spearman rank correlation analysis and logistic regression analysis.Results:Among 1 163 patients, 942 (80.99%) patients had anemia. The incidence of grade 2 and 3 (moderate and severe) anemia in type B and C HBV-ACLF patients was significantly increased ( χ2=72.908, P<0.001). The incidence of macrocytic anemia among type A, B and C HBV-ACLF ranged from 13.0% to 43.98% and 58.33%, respectively( χ2=46.823, P <0.001). The 1-year cumulative survival rate of patients with grade 2 and 3 anemia decreased significantly( χ2=50.179, P<0.001); Spearman rank correlation analysis showed that the correlation coefficient between ABC type and anemia grade was 0.319, P<0.001. Logistic regression analysis showed that gastrointestinal bleeding, acute kidney injury (AKI) and ABC types were independently associated with grade 2 and 3 anemia in patients with HBV-ACLF. Conclusions:Anemia grade is closely related to the prognosis in patients with HBV-ACLF. Gastrointestinal bleeding, AKI and ABC types are independent risk factors for grade 2 and 3 anemia in patients with HBV-ACLF.

Objective:To investigate and analyze the energy metabolism characteristics and the correlation between energy metabolism and the risk of secondary bacterial infection in patients with hepatitis B virus-related chronic liver disease (HBV-CLD).Methods:Data of 183 cases admitted to the Mengchao Hepatobiliary Hospital of Fujian Medical University from November 2017 to November 2020 were retrospectively analyzed. 79 cases of chronic hepatitis B, 51 cases of hepatitis B-related liver cirrhosis, and 53 cases of hepatitis B-related liver failure were collected. Among them patients with liver failure and decompensated liver cirrhosis were defined as severe liver disease group. The Quark RMR indirect calorimetry (COSMED Corporation, Italy) was used to exam the patients' energy metabolism condition, and the incidences of secondary bacterial infection of the patients during hospitalization were recorded. Shapiro-Wilk test and normal QQ plot were used to analyze the normal distribution of continuous variable data, which was consistent with the normal distribution and was described by mean ± standard deviation. In addition, if it did not conform to the normal distribution, the median and interquartile distance were used to describe it. Levene’s test was used to test the homogeneity of variance of the data, which was consistent with the normal distribution. The t-test was used to compare the means of the two groups of samples. One-way analysis of variance was used to compare the mean values of the three groups of samples, and then the Tukey's test was used to compare the two groups. If the variance was uneven or did not conform to the normal distribution, the Wilcoxon rank sum test was used to compare the differences between the two groups. Kruskal-Wallis test (H test) was used to compare the differences between the three groups of samples, and then the Dunnett’s test (Z test) was used for comparison between the two groups. Categorical variable data were analyzed using chi-square test. Logistic regression analysis was used to screen independent risk factors, and the criteria for variable inclusion ( P < 0.05). Results:The respiratory entropy (RQ) and non-protein respiratory entropy (npRQ) of the three groups had statistically significant difference ( P < 0.05). Among them, the RQ and npRQ of the chronic hepatitis B group were higher than hepatitis B-related liver cirrhosis group and hepatitis B-related liver failure group. There were statistically significant differences in fat oxidation rate (FAT%) and carbohydrate oxidation rate (CHO%) between the three groups ( P < 0.05). Compared with hepatitis B-related liver cirrhosis group and hepatitis B-related liver failure group, chronic hepatitis B group ( P < 0.05) had lower FAT% and higher CHO%. There were no statistically significant differences in the measured and predicted resting energy expenditure and protein oxidation rate (PRO%) between the three groups. The incidence of secondary bacterial infection in patients with severe liver disease was 48.39% (45/93). Compared with the non-infected group, the RQ and npRQ values ??of the infected group were significantly decreased ( P < 0.05), while FAT% was significantly increased ( P < 0.05). Logistic regression analysis showed that glutamyltransferase, cholesterol, and npRQ were independent risk factors for secondary bacterial infections in patients with severe liver disease. Glutamyltransferase elevation, and cholesterol and npRQ depletion had suggested an increased risk of secondary bacterial infection. Subgroup analysis of patients with hepatitis B-related liver failure also showed that compared with non-infected group, RQ value and npRQ value of secondary bacterial infection group were significantly decreased ( P < 0.05), while FAT% was significantly increased ( P < 0.05). Conclusion:Patients with hepatitis B virus-related chronic liver disease generally have abnormal energy metabolism. Low RQ, npRQ, CHO% and high FAT% are related to the severity of the disease; while npRQ reduction is related to the risk of secondary bacterial infection in patients with severe liver disease, and thus can be used as a clinical prognostic indicator.

Objective:To observe the effects of T-2 toxin on expression of hepatocyte growth factor (HGF) and HGF receptor (C-Met) in articular cartilage and epiphyseal cartilage of rats under low selenium condition.Methods:Twenty-four healthy male SD rats weighted 60-80 g were randomly divided into conventional diet group (selenium content of 101.5 μg/kg) and low-selenium diet group (selenium content of 1.1 μg/kg), with 12 rats in each group. After 30 days of feeding, the conventional diet group was further divided into conventional group and T-2 toxin group (100 μg·kg -1·d -1), and the low-selenium diet group was further divided into low-selenium group and low-selenium+T-2 toxin group (100 μg·kg -1·d -1), with 6 rats in each group. After 30 days of feeding, the rats were sacrificed and the cartilage of knee joint was taken, the morphological changes of knee articular cartilage and epiphyseal cartilage were observed by HE staining under light microscope. Immunohistochemical method was used to detect the expression of HGF and C-Met in knee articular cartilage and epiphyseal cartilage, and positive expression rates of HGF and C-Met were calculated. Results:Under light microscope, chondrocytes of articular cartilage and epiphyseal cartilage in low-selenium+T-2 toxin group were sparse, and the necrosis and structural area were found in the deep layer, and the extracellular matrix of chondrocytes in the region was degraded and light stained, and proliferating granulation tissue was visible nearby. The positive expression rates of HGF in articular cartilage [(21.97 ± 6.90)%, (49.41 ± 8.24)%, (76.39 ± 5.88)%] and epiphyseal cartilage [(23.36 ± 12.49)%, (58.43 ± 14.48)%, (66.59 ± 10.83)%] of rats in low-selenium, T-2 toxin and low-selenium+T-2 toxin groups were higher than those in conventional group [(9.13 ± 6.01)%, (11.14 ± 4.67)%, P < 0.05]. The positive expression rates of C-Met in articular cartilage [(25.34 ± 7.53)%, (58.21 ± 12.54)%, (81.46 ± 7.89)%] and epiphyseal cartilage [(35.21 ± 4.71)%, (40.84 ± 2.03)%, (49.41 ± 6.29)%] of rats in low-selenium, T-2 toxin and low-selenium+T-2 toxin groups were higher than those in conventional group [(11.21 ± 5.11)%, (12.12 ± 4.71)%, P < 0.05]. Conclusion:T-2 toxin may affect the expression of HGF and C-Met in articular cartilage and epiphyseal cartilage of rats under low selenium condition.

Background The ongoing new coronavirus pneumonia (Corona Virus Disease 2019,COVID-19) outbreak is spreading in China, but it has not yet reached its peak. Five million people emigrated from Wuhan before lockdown, potentially representing a source of virus infection. Determining case distribution and its correlation with population emigration from Wuhan in the early stage of the epidemic is of great importance for early warning and for the prevention of future outbreaks. Methods The official case report on the COVID-19 epidemic was collected as of January 30, 2020. Time and location information on COVID-19 cases was extracted and analyzed using ArcGIS and WinBUGS software. Data on population migration from Wuhan City and Hubei province were extracted from Baidu Qianxi, and their correlation with the number of cases was analyzed. Results The COVID-19 confirmed and death cases in Hubei province accounted for 59.91% (5806/9692) and 95.77% (204/213) of the total cases in China respectively. Hot spot provinces included Sichuan and Yunnan, which are adjacent to Hubei. The time risk of Hubei province on the following day was 1.960 times that on the previous day. The number of cases in some cities was relatively low, but the time risk appeared to be continuously rising. The correlation coefficient between the provincial number of cases and emigration from Wuhan was up to 0.943. The lockdown of 17 cities in Hubei province and the implementation of nationwide control measures efficiently prevented an exponential growth in the number of cases. Conclusion The population that emigrated from Wuhan was the main infection source in other cities and provinces. Some cities with a low number of cases showed a rapid increase in case load. Owing to the upcoming Spring Festival return wave, understanding the risk trends in different regions is crucial to ensure preparedness at both the individual and organization levels and to prevent new outbreaks.

Objective:To investigate the potential mechanism of microRNA (miRNA) in hepatitis B virus (HBV) infection.Methods:The peripheral blood samples were collected from four chronic hepatitis B (CHB) patients who visited Mengchao Hepatobiliary Hospital of Fujian Medical University in 2017, and those were also collected from four healthy controls. Affymetrix GeneChip microRNA 4.0 was applied to detect the expressions of miRNA between CHB patients and healthy controls. The CHB relative differential expressions of miRNA were obtained. The functions of CHB relative miRNA were analyzed by the combination of bioinformatics tools and public database data.Results:A total of seven miRNA were differentially expressed in the peripheral blood of CHB patients. Among them, miRNA-122-5p (log 2 fold change (log 2FC)=7.78, P=0.007 3), let-7c-5p (log 2FC=3.52, P=0.019 6), miRNA-6794-5p (log 2FC=1.15, P=0.033 2), and miRNA-1226-5p (log 2FC=0.68, P=0.034 3) were up-regulated, while miRNA-619-5p (log 2FC=-1.83, P=0.002 6), miRNA-1273g-3p (log 2FC=-2.69, P=0.025 1), and miRNA-4440 (log 2FC=-3.99, P=0.047 8) were down-regulated. Further analysis showed that these miRNA could directly interact with HBV gene sequence and impact the replication of the virus. Among them, miRNA-122-5p, miRNA-6794-5p and miRNA-1226-5p could negatively regulate target genes expression to influence the formation of ficolin-1 rich granule, ficolin-1 rich granule lumen, podosome and membrane ruffle, which participated in the cell membrane movement and cell-matrix adhesion. Conclusion:MiRNA could impact the molecular movement in the cell membrane and facilitate HBV entry to liver cells, playing an important supporting role in HBV infection process.