ObjectiveTo study the regulatory effect of the partial sequence within the 3’ untranslated region （3’UTR） of slit guidance ligand 1 （Slit1） （Slit1-3’UTR） on the fibrotic phenotypes of cardiac fibroblasts （CFs） and its potential mechanism. MethodsThe adenovirus vector was used to overexpress the 1526nt sequence of Slit1-3’UTR in ICR neonatal mouse CFs （mCFs）. The expression of fibrosis-related genes in mCFs， such as collagen type 1 alpha1（COL1A1）， collagen type 3 alpha3 （COL3A1） and alpha smooth muscle actin （α-SMA） were detected by Western blot assay. The effect of Slit1-3’UTR 1526nt on the proliferation and migration of mCFs was assessed by EdU staining and Trans-well assays. Angiotensin Ⅱ （Ang Ⅱ） was used to treat mCFs， and the impact of Slit1-3’UTR 1526nt on the fibrotic phenotypes of Ang Ⅱ-induced mCFs was evaluated. After overexpression of Slit1-3’UTR 1526nt， miR-34a-5p mimic was transfected into mCFs， followed by actinomycin D treatment to detect the mRNA stability of Slit1-3’UTR 1526nt， and the levels of miR-34a-5p and its target gene SIRT1（si-SIRT1） in mCFs were determined. The effects of miR-34a-5p and small interfering RNA targeting SIRT1 on the Slit1-3’UTR 1526nt-mediated regulation of fibrotic phenotypes were also determined. ResultsAdenovirus-mediated overexpression of Slit 1-3’UTR 1526nt was achieved in mCFs. Overexpression of Slit 1-3’UTR 1526nt markedly inhibited the expression of the fibrosis-related genes， proliferation and migration of mCFs and fibrotic phenotypes of Ang Ⅱ. The results of actinomycin D assay showed that miR-34a-5p inhibited the stability of Slit1-3’UTR 1526nt in mCFs， while the level of miR-34a-5p was reduced in mCFs with overexpression of Slit1-3’UTR 1526nt. Transfection of miR-34a-5p promoted the fibrotic phenotypes， and reversed the inhibitory effect of Slit1-3’UTR 1526nt on the fibrotic phenotypes of mCFs. Overexpression of Slit1-3’UTR 1526nt significantly increased the level of miR-34a-5p target gene SIRT1 in mCFs. Transfection of miR-34a-5p and si-SIRT1 consistently reversed the inhibitory effects of Slit1-3’UTR 1526nt on the fibrotic phenotypes of mCFs. ConclusionSlit1-3’UTR1526nt inhibits the fibrotic phenotypes of mCFs by binding to miR-34a-5p and increasing the expression of its target gene of SIRT1.

AIM:This study aims to investigate whether a specific synbiotic,consisting of Bifidobacterium longum subspecies BB536 and fructooligosaccharides,can inhibit colon tumorigenesis by modulating gut flora composi-tion.METHODS:Six-week-old male ApcMin/+mice were randomly divided into control group and synbiotic-treated group,with 8 mice in each group.The mice in synbiotic-treated group received daily gavage of 1×109 CFU/kg of Bifidobacterium longum BB536 and 2 g/kg of fructooligosaccharides,while those in control group were gavaged with sterile water for 10 weeks.The number and size of colon tumors were assessed and compared between the 2 groups.Colon tissue sections were evaluated using hematoxylin-eosin staining,Alcian blue staining,and immunohistochemistry assays.The bacterial compo-sition in the colon was analyzed via 16S rDNA sequencing,and differentially expressed genes were examined through tran-scriptome sequencing and RT-qPCR.RESULTS:The synbiotic treatment significantly enhanced bacterial diversity and increased the relative abundance of Bifidobacterium in the colon(P<0.01).Additionally,the number and size of colon tu-mors were both significantly reduced in the synbiotic-treated mice(P<0.01),along with decreased expression of Ki-67(P<0.01).Concurrently,the number of goblet cells and the expression of epithelial tight junction proteins(ZO-1 and occlu-din)were up-regulated(P<0.05).CONCLUSION:Supplementation with this synbiotic effectively modulated gut flora composition and suppressed colon tumorigenesis in ApcMin/+mice.

AIM:This study aims to investigate whether a specific synbiotic,consisting of Bifidobacterium longum subspecies BB536 and fructooligosaccharides,can inhibit colon tumorigenesis by modulating gut flora composi-tion.METHODS:Six-week-old male ApcMin/+mice were randomly divided into control group and synbiotic-treated group,with 8 mice in each group.The mice in synbiotic-treated group received daily gavage of 1×109 CFU/kg of Bifidobacterium longum BB536 and 2 g/kg of fructooligosaccharides,while those in control group were gavaged with sterile water for 10 weeks.The number and size of colon tumors were assessed and compared between the 2 groups.Colon tissue sections were evaluated using hematoxylin-eosin staining,Alcian blue staining,and immunohistochemistry assays.The bacterial compo-sition in the colon was analyzed via 16S rDNA sequencing,and differentially expressed genes were examined through tran-scriptome sequencing and RT-qPCR.RESULTS:The synbiotic treatment significantly enhanced bacterial diversity and increased the relative abundance of Bifidobacterium in the colon(P<0.01).Additionally,the number and size of colon tu-mors were both significantly reduced in the synbiotic-treated mice(P<0.01),along with decreased expression of Ki-67(P<0.01).Concurrently,the number of goblet cells and the expression of epithelial tight junction proteins(ZO-1 and occlu-din)were up-regulated(P<0.05).CONCLUSION:Supplementation with this synbiotic effectively modulated gut flora composition and suppressed colon tumorigenesis in ApcMin/+mice.

A truncated mutant of the Open Reading Frame 2 (ORF2, aa384-606) was amplified from cDNA of genotype IV hepatitis E virus (HEV) by polymerase chain reaction (PCR), subcloned to expression plasmid pTO-T7, and expressed in Escherichia coli. SDS-PAGE and Western blotting were used to detect and identify the recombinant protein, namely rP24. After washing of inclusion bodies, dissolving in denaturing agents, refoldeding by dialysis, ion exchange chromatography and gel chromatography, dynamic light scatter was used to study the hydrated radius of rP24. Western blotting was applied to detect the immunoreactivity of rP24, and mouse immunity test and indirect enzyme linked immunosorbent assay (ELISA) were applied to evaluate the immunogenicity and the detection rate of HEV positive and negative serum. SDS-PAGE and Western blotting show that rP24 was highly expressed in the form of inclusion bodies after induction, and had strong immunoreactivity to monoclonal antibody (McAb) 15B2. After a multi-step purification of rP24, Western blotting indicated that the purified rP24 also had strong immunoreactivity to neutralizing McAb 8C11 and HEV positive serum, suggesting that rP24 simulated the nature structure of HEV capsid protein. Dynamic light scatter demonstrated that the average hydration radius of purified rP24 was 7.48 nm. The mouse immunity test showed that the purified rP24 also had good immunogenicity, and the period of serum antibodies converted from negative to positive was very short, but the antibodies maintained more than 20 weeks. Indirect ELISA tests showed that the detection rate of was the same as anti-HEV-IgG diagnostic kit (Wan Tai corporation). Taken together, the rP24 simulated the neutralizing epitopes of natural HEV, and had strong immunoreactivity and immunogenicity. It provided a basis for the further investigation of the difference of infection mechanism between genotype I and genotype IV HEV.
Animals ; Antibodies, Monoclonal ; Antibodies, Neutralizing ; Blotting, Western ; Capsid Proteins ; biosynthesis ; Electrophoresis, Polyacrylamide Gel ; Enzyme-Linked Immunosorbent Assay ; Epitopes ; Genotype ; Hepatitis E virus ; Mice ; Mutant Proteins ; biosynthesis ; Open Reading Frames ; Recombinant Proteins ; biosynthesis