This study was aimed at preliminarily investigating the molecular biological functions of the PPE65 protein from Myco-bacterium tuberculosis,and providing foundational data for tuberculosis prevention and control.The basic biological properties of the PPE65 gene-encoded protein were predicted with bioinformatics tools.Sequence information for the Mycobacterium tuberculosis Rv3621c gene and PPE65 protein was retrieved from the NCBI database.The Rv3621c gene was amplified through PCR with the H37Rv genome as a template,then cloned into the pET22b(+)expression vector.The recombinant pET22b(+)-PPE65 plasmid was transformed into Escherichia coli BL21(DE3)competent cells for IPTG-induced expression.Solubility analysis,purification,and identification of the recombinant PPE65 protein were performed.BEAS-2B cells were treated with various concentrations of PPE65 protein for 24 h,and cell proliferation was assessed with CCK-8 assays.PPE65 was found to be composed of 413 amino acids and to have a molecular formula of C????H????N???O???S??,a relative molecular mass of 40 679.88,a theoretical isoelectric point of 4.60,an ali-phatic index of 81.94,and an average hydrophilicity value of 0.319,thus indicating a stable hydrophobic protein lacking signal pep-tides or transmembrane domains.Secondary structure analysis revealed 53.03%α-helix(Hh),2.66%β-sheet(Ee),and 44.31%ran-dom coil(Cc).Bioinformatics predictions identified 38 B-cell epitopes and 22 CTL/Th-cell epitopes.The full-length PPE65 gene(1 308 bp)was confirmed through double restriction enzyme digestion and sequencing,thereby validating the correct construction of the pET22b(+)-PPE65 recombinant plasmid.SDS-PAGE analysis demonstrated that the recombinant protein was found in inclusion bodies,and a single band at 43.7 kDa was observed after purification.Western blotting revealed specific binding to mouse-derived His monoclonal antibodies,thereby confirming successful expression of the PPE65 protein.BEAS-2B cells treated with a PPE65 protein concentration gradient(2.5-20 μg/mL)exhibited a dose-dependent increase in cell number.Compared with those in the PBS control group,TGF-β relative expression levels were significantly higher in all treatment groups(t2.5=4.893,P<0.001,t5.0=4.640,P<0.05,t10=7.535,P<0.05,t20=16.44,P<0.000 1).This study elucidated the structural characteristics of the PPE65 protein,successfully obtained the recombinant protein through prokaryotic expression and purification,and demonstrated its ability to promote BEAS-2B cell proliferation.The underlying mechanism might involve suppression of TGF-β/S mad signaling pathway activation.These findings provide a theoretical basis for understanding the role and regulatory mechanisms of PPE65 during M.tuberculosis infection.

This study was aimed at preliminarily investigating the molecular biological functions of the PPE65 protein from Myco-bacterium tuberculosis,and providing foundational data for tuberculosis prevention and control.The basic biological properties of the PPE65 gene-encoded protein were predicted with bioinformatics tools.Sequence information for the Mycobacterium tuberculosis Rv3621c gene and PPE65 protein was retrieved from the NCBI database.The Rv3621c gene was amplified through PCR with the H37Rv genome as a template,then cloned into the pET22b(+)expression vector.The recombinant pET22b(+)-PPE65 plasmid was transformed into Escherichia coli BL21(DE3)competent cells for IPTG-induced expression.Solubility analysis,purification,and identification of the recombinant PPE65 protein were performed.BEAS-2B cells were treated with various concentrations of PPE65 protein for 24 h,and cell proliferation was assessed with CCK-8 assays.PPE65 was found to be composed of 413 amino acids and to have a molecular formula of C????H????N???O???S??,a relative molecular mass of 40 679.88,a theoretical isoelectric point of 4.60,an ali-phatic index of 81.94,and an average hydrophilicity value of 0.319,thus indicating a stable hydrophobic protein lacking signal pep-tides or transmembrane domains.Secondary structure analysis revealed 53.03%α-helix(Hh),2.66%β-sheet(Ee),and 44.31%ran-dom coil(Cc).Bioinformatics predictions identified 38 B-cell epitopes and 22 CTL/Th-cell epitopes.The full-length PPE65 gene(1 308 bp)was confirmed through double restriction enzyme digestion and sequencing,thereby validating the correct construction of the pET22b(+)-PPE65 recombinant plasmid.SDS-PAGE analysis demonstrated that the recombinant protein was found in inclusion bodies,and a single band at 43.7 kDa was observed after purification.Western blotting revealed specific binding to mouse-derived His monoclonal antibodies,thereby confirming successful expression of the PPE65 protein.BEAS-2B cells treated with a PPE65 protein concentration gradient(2.5-20 μg/mL)exhibited a dose-dependent increase in cell number.Compared with those in the PBS control group,TGF-β relative expression levels were significantly higher in all treatment groups(t2.5=4.893,P<0.001,t5.0=4.640,P<0.05,t10=7.535,P<0.05,t20=16.44,P<0.000 1).This study elucidated the structural characteristics of the PPE65 protein,successfully obtained the recombinant protein through prokaryotic expression and purification,and demonstrated its ability to promote BEAS-2B cell proliferation.The underlying mechanism might involve suppression of TGF-β/S mad signaling pathway activation.These findings provide a theoretical basis for understanding the role and regulatory mechanisms of PPE65 during M.tuberculosis infection.

Objective To investigate the effect of fibulin-3 on the senescence of intervertebral disc nucleus pulposus cells(NPCs)through the regulation of tissue inhibitor of metalloproteinases 3(TIMP-3)expression and to elucidate the molecular mechanisms involved.Methods 1).The nucleus pulposus tissues and imaging data of 37 patients who had undergone intervertebral disc surgery were collected.The degree of degeneration of the intervertebral discs were classified according to the Pfirrmann grading system.The senescence degree of NPCs was determined using senescence-associated β-galactosidase(SA-β-gal)staining.Fibulin-3 expression levels were determined using Western blot and ELISA.The relationship between fibulin-3 and disc degeneration and NPCs senescence was investigated.2).Human intervertebral disc NPCs were cultured in vitro.The proliferation and senescence of NPC across continuous passage were observed via CCK-8 assay and SA-β-gal staining,respectively.Fibulin-3 expression levels and the expression of inflammatory cytokines and matrix metalloproteinases were assessed.Exogenous fibulin-3 was added to verify its effect on the proliferation and senescence of NPCs.3).The effect of fibulin-3 on the apoptosis and proliferation of NPCs was verified through gene overexpression,which was used in combination with an apoptosis inhibitor for bidirectional verification.4).Bioinformatics analysis was performed to explore the relationship between fibulin-3 and the TIMP family.Experiments overexpressing fibulin-3 and silencing the TIMP-3 gene were performed to verify their role in NPCs senescence.Results 1).The intervertebral disc degeneration samples from 37 patients were classified according to the Pfirrmann grading system.The higher the degeneration grade,the lower fibulin-3 expression.Spearman correlation analysis showed that the disc grade was negatively correlated with the NPC senescence grade(r=-0.87,P＜0.001)and fibulin-3 expression(r=-0.79,P＜0.001).2).As the passage number of NPCs increased,fibulin-3 expression gradually decreased,cell proliferation ability weakened,and the expression of inflammatory cytokines and matrix metalloproteinases increased.After exogenous fibulin-3 was added,cell morphology and growth status were maintained,cell senescence was significantly inhibited,and the expression of inflammatory cytokines and matrix metalloproteinases was markedly reduced.3).Gene overexpression experiments showed that fibulin-3 reduced NPC apoptosis and promoted cell proliferation,thereby inhibiting NPC senescence.4).Bioinformatics analysis revealed a significant association between fibulin-3 and TIMP-3 of the TIMP family.Further experiments confirmed that overexpressing fibulin-3 enhanced TIMP-3 expression,while silencing the TIMP-3 gene significantly weakened the inhibitory effect of fibulin-3 on NPCs senescence.This indicates that,through regulating TIMP-3,fibulin-3 inhibits the activity of matrix metalloproteinases,affects the synthesis and degradation of the extracellular matrix,and ultimately inhibits NPCs senescence.Conclusion This study demonstrates that fibulin-3 plays a crucial role in inhibiting the senescence of intervertebral disc NPCs by regulating TIMP-3.The specific mechanisms involved are as follows,fibulin-3 upregulates TIMP-3 expression,inhibits matrix metalloproteinase activity,and reduces extracellular matrix degradation,thereby promoting extracellular matrix synthesis.Additionally,fibulin-3 inhibits NPCs senescence by reducing apoptosis and promoting cell proliferation.Therefore,fibulin-3 and TIMP-3 have potential therapeutic significance in maintaining intervertebral disc health and delaying degeneration.

BACKGROUND:Different types of nerve regulatory factors and glial cells have been reported to exert different roles in the differentiation and maturation of neural stem cells, but culturing neural stem cells in large animals is relatively rarely reported. OBJECTIVE:To explore the way for culturing goat neural stem cells and to detect the outcome after in vitro differentiation. METHODS:The neural stem cellwas separated and cultured from the newborn goat cerebral cortex and the anti-nestin immunocytochemical staining was performed for cellidentification. At the same time, anti-S100 active Schwann cells were gotten from the sciatic nerve. Then in vitro differentiation was preformed and the outcome was detected by the immunocytochemical stain of anti-glial fibril ary acidic protein, anti-microtubule-associated protein 2 and anti-S100. cells without primary antibodies served as controls. Gray values were calculated and compared. RESULTS AND CONCLUSION:The Schwann cells were cultured successful y, which were active to the anti-nestin immunocytochemical staining and anti-S100 staining. After differentiation, the products were active to anti-glial fibril ary acidic protein and anti-microtubule-associated protein 2 immunocytochemical stain, but Abstract BACKGROUND:Different types of nerve regulatory factors and glial cells have been reported to exert different roles in the differentiation and maturation of neural stem cells, but culturing neural stem cells in large animals is relatively rarely reported. OBJECTIVE:To explore the way for culturing goat neural stem cells and to detect the outcome after in vitro differentiation. METHODS:The neural stem cellwas separated and cultured from the newborn goat cerebral cortex and the anti-nestin immunocytochemical staining was performed for cellidentification. At the same time, anti-S100 active Schwann cells were gotten from the sciatic nerve. Then in vitro differentiation was preformed and the outcome was detected by the immunocytochemical stain of anti-glial fibril ary acidic protein, anti-microtubule-associated protein 2 and anti-S100. cells without primary antibodies served as controls. Gray values were calculated and compared. RESULTS AND CONCLUSION:The Schwann cells were cultured successful y, which were active to the anti-nestin immunocytochemical staining and anti-S100 staining. After differentiation, the products were active to anti-glial fibril ary acidic protein and anti-microtubule-associated protein 2 immunocytochemical stain, but negative to the anti-S100. And significant difference was found in gray values. The goat neural stem cells and Schwann cells were successful y cultured and identified. After the differentiation, the astrocytes and neurons were detected, but the Schwann cells were not found.

Our investigation was conducted in order to verify a recent severe epidemic at several swine farms in northern China that indicated a newly emerging disease. Evidence confirmed that the epidemic was caused by a virulent Pseudorabies virus infection in swine herds.
Animals ; China/epidemiology ; Enzyme-Linked Immunosorbent Assay/veterinary ; Epidemics/*veterinary ; Herpesvirus 1, Suid/classification/*isolation & purification/*pathogenicity ; Pseudorabies/*epidemiology/mortality/pathology/virology ; Reverse Transcriptase Polymerase Chain Reaction/veterinary ; Sequence Analysis, DNA/veterinary ; Swine ; Swine Diseases/*epidemiology/mortality/pathology/virology ; Vaccination/adverse effects/veterinary ; Virulence