Calf thymus DNA was exposed to low-energy heavy ions (N+) and 60Co-γ-rays, and the dose-effect on DNA single-strand breaks (SSB) has been investigated. The results indicate that the dose-effect curve by N+ irradiatio...Calf thymus DNA was exposed to low-energy heavy ions (N+) and 60Co-γ-rays, and the dose-effect on DNA single-strand breaks (SSB) has been investigated. The results indicate that the dose-effect curve by N+ irradiation is different from that of conventional ionizing radiation. While the curve from γ-irradiation follows exponential type, the effect curve produced by N+ ion is of 'saddle type'. The yield of DNASSB per dose unit per DNA unit remained at a certain level under different doses of γ-rays. In contrast, the DNASSB at low dosage region of N+ showed an obvious peak before it decreased rapidly to a lower level.展开更多
African swine fever virus(ASFV)infects domestic pigs and European wild boars with strong,hemorrhagic and high mortality.The primary cellular targets of ASFV is the porcine macrophages.Up to now,no commercial vaccine o...African swine fever virus(ASFV)infects domestic pigs and European wild boars with strong,hemorrhagic and high mortality.The primary cellular targets of ASFV is the porcine macrophages.Up to now,no commercial vaccine or effective treatment available to control the disease.In this study,three recombinant Saccharomyces cerevisiae(S.cerevisiae)strains expressing fused ASFV proteins-porcine Ig heavy chains were constructed and the immunogenicity of the S.cerevisiae-vectored cocktail ASFV feeding vaccine was further evaluated.To be specific,the P30-Fcγand P54-Fcαfusion proteins displaying on surface of S.cerevisiae cells were produced by fusing the Fc fragment of porcine immunoglobulin IgG1 or IgA1 with p30 or p54 gene of ASFV respectively.The recombinant P30-Fcγand P54-Fcαfusion proteins expressed by S.cerevisiae were verified by Western blotting,flow cytometry and immunofluorescence assay.Porcine immunoglobulin Fc fragment fused P30/P54 proteins elicited P30/P54-specific antibody production and induced higher mucosal immunity in swine.The absorption and phagocytosis of recombinant S.cerevisiae strains in IPEC-J2 cells or porcine alveolar macrophage(PAM)cells were significantly enhanced,too.Here,we introduce a kind of cheap and safe oral S.cerevisiae-vectored vaccine,which could activate the specific mucosal immunity for controlling ASFV infection.展开更多
Mutations or inactivation of parkin, an E3 ubiquitin ligase, are associated with familial form or sporadic Parkinson＇s disease （PD）, respectively, which manifested with the selective vulnerability of neuronal ceils...Mutations or inactivation of parkin, an E3 ubiquitin ligase, are associated with familial form or sporadic Parkinson＇s disease （PD）, respectively, which manifested with the selective vulnerability of neuronal ceils in substantia nigra （SN） and striatum （STR） regions. However, the underlying molecular mechanism linking parkin with the etiology of PD remains elusive. Here we report that p62, a critical regulator for protein quality control, inclusion body formation, selective autophagy and diverse signaling pathways, is a new substrate of parkin. P62 levels were increased in the SN and STR regions, but not in other brain regions in parkin knockout mice. Parkin directly interacts with and ubiquitinates p62 at the K13 to promote proteasomal degradation of p62 even in the absence of ATG5. Pathogenic mutations, knockdown of parkin or mutation of p62 at K13 prevented the degradation of p62. We further showed that parkin deficiency mice have pronounced loss of tyrosine hydroxylase positive neurons and have worse performance in motor test when treated with 6-hydroxydopamine hydrochloride in aged mice. These results suggest that, in addition to their critical role in regulating autophagy, p62 are subjected to parkin mediated proteasomal degradation and implicate that the dysregulation of parkin/p62 axis may involve in the selective vulnerability of neuronal cells during the onset of PD pathogenesis.展开更多
High mobility group box 1(HMGB1)has been reported to play an important role in experimental autoimmune encephalomyelitis(EAE).Astrocytes are important components of neurovascular units and tightly appose the endotheli...High mobility group box 1(HMGB1)has been reported to play an important role in experimental autoimmune encephalomyelitis(EAE).Astrocytes are important components of neurovascular units and tightly appose the endothelial cells of microvessels by their perivascular endfeet and directly regulate the functions of the blood-brain barrier.Astrocytes express more HMGB1 during EAE while the exact roles of astrocytic HMGB1 in EAE have not been well elucidated.Here,using conditional-knockout mice,we found that astrocytic HMGB1 depletion decreased morbidity,delayed the onset time,and reduced the disease score and demyelination of EAE.Meanwhile,there were fewer immune cells,especially pathogenic T cells infiltration in the central nervous system of astrocytic HMGB1 conditional-knockout EAE mice,accompanied by up-regulated expression of the tight-junction protein Claudin5 and down-regulated expression of the cell adhesion molecules ICAM1 and VCAM1 in vivo.In vitro,HMGB1 released from astrocytes decreased Claudin5 while increased ICAM1 and VCAM1 expressed by brain microvascular endothelial cells(BMECs)through TLR4 or RAGE.Taken together,our results demonstrate that HMGB1 derived from astrocytes aggravates EAE by directly influencing the immune cell infiltration-associated functions of BMECs.展开更多
A subsystem impactor test for pedestrian lower limb injury evaluation has been brought in China New Car Assessment Protocol(CNCAP).Concerning large anthropometric differences of the people from different countries,the...A subsystem impactor test for pedestrian lower limb injury evaluation has been brought in China New Car Assessment Protocol(CNCAP).Concerning large anthropometric differences of the people from different countries,the present study aims to establish and validate a finite element lower limb model representing 50th Chinese male size for pedestrian safety research,then compare its biomechanical responses with the general models currently in wide use in the world for pedestrian safety evaluation.Concerning the vehicle-pedestrian impact loading environment,the previously developed lower limb model with three-dimensional muscles was adjusted and validated through the related experiments.Then,the biomechanical responses of the validated model were compared with the Total Human Model for Safety(THUMS)and Advanced Pedestrian Legform Impactor(aPLI)models by combing with four typical vehicles.The results showed that both consistency and significant differences of biomechanical responses existed between the present model and the other two models.The injury measurements of the thigh region of the present model showed extremely large differences with the other two models,while the tibia and Medial Collateral Ligament(MCL)injury measurements show similar values.Thus,it can be concluded that directly using the aPLI or THUMS models for Chinese pedestrian safety evaluation is not robust concerning both kinematic responses and injury measurements.展开更多
It has been reported that splenic stromal cells(SSCs)are capable of directly supporting the development of CD11c ^(lo)CD45RB^(+) IL-10-producing dendritic cells(DCs)from lineage-negative c-kit^(+) progenitor cells in ...It has been reported that splenic stromal cells(SSCs)are capable of directly supporting the development of CD11c ^(lo)CD45RB^(+) IL-10-producing dendritic cells(DCs)from lineage-negative c-kit^(+) progenitor cells in the absence of exogenous cytokines.In vitro,DCs that differentiate on stromal cells suppress mixed leukocyte reaction responses and induce primary alloreactive CD4^(+) T cells to differentiate into IL-10-producing Tr1 cells.However,the precise mechanisms by which these SSCs exert their regulatory functions in vivo remain undefined.Furthermore,their possible contribution to the development of allograft transplantation tolerance has yet to be examined.Here,we have used both murine skin and cardiac allograft transplantation models to explore whether in vivo alloresponses can be regulated by infusion with donor-derived SSCs and to investigate the possible mechanisms by which SSCs exert regulatory effects to prevent allograft rejection.We show that intravenous SSC infusion prolonged murine skin allograft survival.The prolonged graft survival is associated with augmentation of the generation of regulatory DC subsets and CD4^(+) CD25^(+) Foxp3^(+) regulatory T cells(Tregs),as well as upregulation of the production of suppressive cytokines IL-10 and transforming growth factor(TGF)-b.Moreover,we found that indoleamine 2,3-dioxygenase and SSC-derived regulatory DCs contribute to allograft protection by infusion of donor-specific SSCs.Our data suggest that donor-derived SSCs could be used as a therapeutic target to promote transplantation tolerance.展开更多
文摘Calf thymus DNA was exposed to low-energy heavy ions (N+) and 60Co-γ-rays, and the dose-effect on DNA single-strand breaks (SSB) has been investigated. The results indicate that the dose-effect curve by N+ irradiation is different from that of conventional ionizing radiation. While the curve from γ-irradiation follows exponential type, the effect curve produced by N+ ion is of 'saddle type'. The yield of DNASSB per dose unit per DNA unit remained at a certain level under different doses of γ-rays. In contrast, the DNASSB at low dosage region of N+ showed an obvious peak before it decreased rapidly to a lower level.
基金supported by the National Key Research and Development Program of China (2018YFD0500500)。
文摘African swine fever virus(ASFV)infects domestic pigs and European wild boars with strong,hemorrhagic and high mortality.The primary cellular targets of ASFV is the porcine macrophages.Up to now,no commercial vaccine or effective treatment available to control the disease.In this study,three recombinant Saccharomyces cerevisiae(S.cerevisiae)strains expressing fused ASFV proteins-porcine Ig heavy chains were constructed and the immunogenicity of the S.cerevisiae-vectored cocktail ASFV feeding vaccine was further evaluated.To be specific,the P30-Fcγand P54-Fcαfusion proteins displaying on surface of S.cerevisiae cells were produced by fusing the Fc fragment of porcine immunoglobulin IgG1 or IgA1 with p30 or p54 gene of ASFV respectively.The recombinant P30-Fcγand P54-Fcαfusion proteins expressed by S.cerevisiae were verified by Western blotting,flow cytometry and immunofluorescence assay.Porcine immunoglobulin Fc fragment fused P30/P54 proteins elicited P30/P54-specific antibody production and induced higher mucosal immunity in swine.The absorption and phagocytosis of recombinant S.cerevisiae strains in IPEC-J2 cells or porcine alveolar macrophage(PAM)cells were significantly enhanced,too.Here,we introduce a kind of cheap and safe oral S.cerevisiae-vectored vaccine,which could activate the specific mucosal immunity for controlling ASFV infection.
基金We are grateful to Drs. Ted Dawson and Jian Feng for generously providing the plasmids. We are also grateful to Professor Mark Bartlam from Nankai University, Tianjin, China for a critical reading of the manuscript. The research was supported by the National Basic Research Program （973 Program） （No. 2011 CB910903） from MOST and project （Grant Nos. 81130045, 31471300, 31271529, 301520103904） from the National Natural Science Foundation of China.
文摘Mutations or inactivation of parkin, an E3 ubiquitin ligase, are associated with familial form or sporadic Parkinson＇s disease （PD）, respectively, which manifested with the selective vulnerability of neuronal ceils in substantia nigra （SN） and striatum （STR） regions. However, the underlying molecular mechanism linking parkin with the etiology of PD remains elusive. Here we report that p62, a critical regulator for protein quality control, inclusion body formation, selective autophagy and diverse signaling pathways, is a new substrate of parkin. P62 levels were increased in the SN and STR regions, but not in other brain regions in parkin knockout mice. Parkin directly interacts with and ubiquitinates p62 at the K13 to promote proteasomal degradation of p62 even in the absence of ATG5. Pathogenic mutations, knockdown of parkin or mutation of p62 at K13 prevented the degradation of p62. We further showed that parkin deficiency mice have pronounced loss of tyrosine hydroxylase positive neurons and have worse performance in motor test when treated with 6-hydroxydopamine hydrochloride in aged mice. These results suggest that, in addition to their critical role in regulating autophagy, p62 are subjected to parkin mediated proteasomal degradation and implicate that the dysregulation of parkin/p62 axis may involve in the selective vulnerability of neuronal cells during the onset of PD pathogenesis.
基金the National Natural Science Foundation of China(31670876 and 82171761).
文摘High mobility group box 1(HMGB1)has been reported to play an important role in experimental autoimmune encephalomyelitis(EAE).Astrocytes are important components of neurovascular units and tightly appose the endothelial cells of microvessels by their perivascular endfeet and directly regulate the functions of the blood-brain barrier.Astrocytes express more HMGB1 during EAE while the exact roles of astrocytic HMGB1 in EAE have not been well elucidated.Here,using conditional-knockout mice,we found that astrocytic HMGB1 depletion decreased morbidity,delayed the onset time,and reduced the disease score and demyelination of EAE.Meanwhile,there were fewer immune cells,especially pathogenic T cells infiltration in the central nervous system of astrocytic HMGB1 conditional-knockout EAE mice,accompanied by up-regulated expression of the tight-junction protein Claudin5 and down-regulated expression of the cell adhesion molecules ICAM1 and VCAM1 in vivo.In vitro,HMGB1 released from astrocytes decreased Claudin5 while increased ICAM1 and VCAM1 expressed by brain microvascular endothelial cells(BMECs)through TLR4 or RAGE.Taken together,our results demonstrate that HMGB1 derived from astrocytes aggravates EAE by directly influencing the immune cell infiltration-associated functions of BMECs.
基金This work is supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(Grant No.51621004)National Natural Science Foundation of China(Grant No.51875187)+1 种基金Hunan Youth Talent Program(Grant No.2020RC3016)Hunan Provincial Natural Science Foundation of China(Grant No.2019JJ40021).
文摘A subsystem impactor test for pedestrian lower limb injury evaluation has been brought in China New Car Assessment Protocol(CNCAP).Concerning large anthropometric differences of the people from different countries,the present study aims to establish and validate a finite element lower limb model representing 50th Chinese male size for pedestrian safety research,then compare its biomechanical responses with the general models currently in wide use in the world for pedestrian safety evaluation.Concerning the vehicle-pedestrian impact loading environment,the previously developed lower limb model with three-dimensional muscles was adjusted and validated through the related experiments.Then,the biomechanical responses of the validated model were compared with the Total Human Model for Safety(THUMS)and Advanced Pedestrian Legform Impactor(aPLI)models by combing with four typical vehicles.The results showed that both consistency and significant differences of biomechanical responses existed between the present model and the other two models.The injury measurements of the thigh region of the present model showed extremely large differences with the other two models,while the tibia and Medial Collateral Ligament(MCL)injury measurements show similar values.Thus,it can be concluded that directly using the aPLI or THUMS models for Chinese pedestrian safety evaluation is not robust concerning both kinematic responses and injury measurements.
基金This work was supported by the National Natural Science Foundation of China(grants 30772039 and 81072440)the National Natural Science Foundation of China-Guangdong Province Union Grant(U0832003)the Ministry of Science and Technology of China(grant 2007CB512402).
文摘It has been reported that splenic stromal cells(SSCs)are capable of directly supporting the development of CD11c ^(lo)CD45RB^(+) IL-10-producing dendritic cells(DCs)from lineage-negative c-kit^(+) progenitor cells in the absence of exogenous cytokines.In vitro,DCs that differentiate on stromal cells suppress mixed leukocyte reaction responses and induce primary alloreactive CD4^(+) T cells to differentiate into IL-10-producing Tr1 cells.However,the precise mechanisms by which these SSCs exert their regulatory functions in vivo remain undefined.Furthermore,their possible contribution to the development of allograft transplantation tolerance has yet to be examined.Here,we have used both murine skin and cardiac allograft transplantation models to explore whether in vivo alloresponses can be regulated by infusion with donor-derived SSCs and to investigate the possible mechanisms by which SSCs exert regulatory effects to prevent allograft rejection.We show that intravenous SSC infusion prolonged murine skin allograft survival.The prolonged graft survival is associated with augmentation of the generation of regulatory DC subsets and CD4^(+) CD25^(+) Foxp3^(+) regulatory T cells(Tregs),as well as upregulation of the production of suppressive cytokines IL-10 and transforming growth factor(TGF)-b.Moreover,we found that indoleamine 2,3-dioxygenase and SSC-derived regulatory DCs contribute to allograft protection by infusion of donor-specific SSCs.Our data suggest that donor-derived SSCs could be used as a therapeutic target to promote transplantation tolerance.
