Although autologous nerve transplantation is the gold standard for treating peripheral nerve defects,it has many clinical limitations.As an alternative,various tissue-engineered nerve grafts have been developed to sub...Although autologous nerve transplantation is the gold standard for treating peripheral nerve defects,it has many clinical limitations.As an alternative,various tissue-engineered nerve grafts have been developed to substitute for autologous nerves.In this study,a novel nerve graft composed of chitin scaffolds and a small autologous nerve was used to repair sciatic nerve defects in rats.The novel nerve graft greatly facilitated regeneration of the sciatic nerve and myelin sheath,reduced atrophy of the target muscle,and effectively restored neurological function.When the epineurium of the small autogenous nerve was removed,the degree of nerve regeneration was similar to that which occurs after autogenous nerve transplantation.These findings suggest that our novel nerve graft might eventually be a new option for the construction of tissue-engineered nerve scaffolds.The study was approved by the Research Ethics Committee of Peking University People's Hospital(approval No.2019 PHE27)on October 18,2019.展开更多
Neuregulin-1 type Ⅲ is a key regulator in Schwann cell proliferation, committing to a myelinat- ing fate and regulating myelin sheath thickness. However, the expression pattern of neuregulin- 1 type III in the periph...Neuregulin-1 type Ⅲ is a key regulator in Schwann cell proliferation, committing to a myelinat- ing fate and regulating myelin sheath thickness. However, the expression pattern of neuregulin- 1 type III in the peripheral nervous system during developmental periods （such as the premyelin- ating stage, myelinating stage and postmyelinating stage） has rarely been studied. In this study, dorsal root ganglia were isolated from rats between postnatal day 1 and postnatal day 56. The expression pattern of neuregulin-1 type III in dorsal root ganglia neurons at various develop- mental stages were compared by quantitative real-time polymerase chain reaction, western blot assay and immunofluorescent staining. The expression of neuregulin-I type Ⅲ mRNA reached its peak at postnatal day 3 and then stabilized at a relative high expression level from postnatal day 3 to postnatal day 56. The expression of neuregulin-1 type III protein increased gradually from postnatal day 1, reached a peak at postnatal day 28, and then decreased at postnatal day 56. Immunofluorescent staining results showed a similar tendency to western blot assay results. Experimental findings indicate that the expression of neuregulin-1 type III in rat dorsal root ganglion was increased during the premyelinating （from postnatal day 2 to postnatal day 5） and myelinating stage （from postnatal day 5 to postnatal day 10）, but remained at a high level in the postmyelinating stage （after postnatal day 10）.展开更多
A novel ligand (3), in which the indenyl group is linked to a β-diketone moiety through a three-carbon bridge, andits titanium complex (4) were synthesized. The titanium complex was employed as a metallocene analog w...A novel ligand (3), in which the indenyl group is linked to a β-diketone moiety through a three-carbon bridge, andits titanium complex (4) were synthesized. The titanium complex was employed as a metallocene analog with co-catalystmethylaluminoxane (MAO) in catalytic syndiospecific polymerization of styrene to give highly syndiotactic polystyrene(s-PS, 96%-97%). Polymerization temperature (T_p) strongly influenced the catalytic activity and syndiotacticity of theproduced PS. The activities of catalyst 4 increase from 1.84×10~6 to 3.26×10~6 gPS/molTi·h with the increase of T_p from60℃ to 80℃ and the syndiotacticities of the produced s-PS also increase slightly. Then, both the catalytic activity and thesyndiotacticity of PS decrease at T_p of 90℃.展开更多
Introduction Organ transplantation increases survival and improves qual-ity of life to many patients with end-stage organ failure.Or-gan shortage is a worldwide problem that restricts organ trans-plantation[1].Organ p...Introduction Organ transplantation increases survival and improves qual-ity of life to many patients with end-stage organ failure.Or-gan shortage is a worldwide problem that restricts organ trans-plantation[1].Organ procurement and preservation as well as ischemia-reperfusion injury(IRI)after transplantation are the im-portant factors affecting prognosis of recipients.Since the de-velopment of organ transplantation technology in the 20th cen-tury,organ protection technology has been a most promising con-cept in this field.Organ preservation solutions such as the Collins solution,University of Wisconsin(UW)solution,and histidine-tryptophan-ketoglutarate(HTK)solution were developed sequen-tially[2],which developed rapidly in static cold storage(SCS)tech-niques.SCS remains the standard preservation technique for organ transplantation[2].展开更多
Background:Natural anti-sense transcripts(NATs),which are transcribed from the complementary DNA strand of annotated genes,exert regulatory function of gene expression.Increasing studies recognized anti-sense transcri...Background:Natural anti-sense transcripts(NATs),which are transcribed from the complementary DNA strand of annotated genes,exert regulatory function of gene expression.Increasing studies recognized anti-sense transcription widespread throughout human cytomegalovirus(HCMV)genome,whereas the anti-sense transcription of RNA1.2 gene locus has never been investigated.In this study,the transcription of the RNA1.2 anti-sense strand was investigated in clinically isolated HCMV strain.Methods:Strand-specific high-through RNA-sequencing(RNA-seq)was performed to find possible anti-sense transcripts(ASTs).For analyzing and visualization of RNA-seq data sets,Integrative Genomics Viewer software was applied.To confirm these possibilities,Northern blotting and rapid amplification of cDNA ends(RACE)were used.Results:Transcription of the opposite strand of RNA1.2 gene locus was detected by RNA-sequencing using RNAs extracted from human embryonic lung fibroblasts infected with HCMV clinical isolate HAN.At least three HCMV NATs,named RNA1.2 AST 1,RNA1.2 AST2,and RNA 1.2 AST3,were characterized by Northern blotting and RACE analyses.These RNA1.2 ASTs orientated from the complementary strand of RNA1.2 locus during the late phase of HCMV infection.The 5'-and 3'-termini of these transcripts were located within the opposite sequence of the predicted RNA1.2 gene.Conclusion:A cluster of novel NATs was transcribed from the opposite sequence of the HCMV RNA 1.2 gene region.展开更多
基金supported by the National Natural Science Foundation of China,Nos.31571236(to YHK),81971177(to BGJ)Key Laboratory of Trauma and Neural Regeneration(Peking University)of the Ministry of Education of China,No.BMU2020XY005-03(to BGJ)+2 种基金the National Key Research and Development Program of China,No.2016YFC1101604(to DYZ)the Ministry of Education Innovation Program of China,No.IRT_16R01(to BGJ)China Postdoctoral Science Foundation-Funded Project,No.2019M664007(to ZYL)。
文摘Although autologous nerve transplantation is the gold standard for treating peripheral nerve defects,it has many clinical limitations.As an alternative,various tissue-engineered nerve grafts have been developed to substitute for autologous nerves.In this study,a novel nerve graft composed of chitin scaffolds and a small autologous nerve was used to repair sciatic nerve defects in rats.The novel nerve graft greatly facilitated regeneration of the sciatic nerve and myelin sheath,reduced atrophy of the target muscle,and effectively restored neurological function.When the epineurium of the small autogenous nerve was removed,the degree of nerve regeneration was similar to that which occurs after autogenous nerve transplantation.These findings suggest that our novel nerve graft might eventually be a new option for the construction of tissue-engineered nerve scaffolds.The study was approved by the Research Ethics Committee of Peking University People's Hospital(approval No.2019 PHE27)on October 18,2019.
基金supported by grants from the National Program on Key Basic Research Project of China(973 Program),No.2014CB542206the National Natural Science Foundation of China,No.81201389,30973052Program for Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China,No.IRT13051
文摘Neuregulin-1 type Ⅲ is a key regulator in Schwann cell proliferation, committing to a myelinat- ing fate and regulating myelin sheath thickness. However, the expression pattern of neuregulin- 1 type III in the peripheral nervous system during developmental periods （such as the premyelin- ating stage, myelinating stage and postmyelinating stage） has rarely been studied. In this study, dorsal root ganglia were isolated from rats between postnatal day 1 and postnatal day 56. The expression pattern of neuregulin-1 type III in dorsal root ganglia neurons at various develop- mental stages were compared by quantitative real-time polymerase chain reaction, western blot assay and immunofluorescent staining. The expression of neuregulin-I type Ⅲ mRNA reached its peak at postnatal day 3 and then stabilized at a relative high expression level from postnatal day 3 to postnatal day 56. The expression of neuregulin-1 type III protein increased gradually from postnatal day 1, reached a peak at postnatal day 28, and then decreased at postnatal day 56. Immunofluorescent staining results showed a similar tendency to western blot assay results. Experimental findings indicate that the expression of neuregulin-1 type III in rat dorsal root ganglion was increased during the premyelinating （from postnatal day 2 to postnatal day 5） and myelinating stage （from postnatal day 5 to postnatal day 10）, but remained at a high level in the postmyelinating stage （after postnatal day 10）.
基金This project was supported by the National Natural Science Foundation of China (No. 29734141).
文摘A novel ligand (3), in which the indenyl group is linked to a β-diketone moiety through a three-carbon bridge, andits titanium complex (4) were synthesized. The titanium complex was employed as a metallocene analog with co-catalystmethylaluminoxane (MAO) in catalytic syndiospecific polymerization of styrene to give highly syndiotactic polystyrene(s-PS, 96%-97%). Polymerization temperature (T_p) strongly influenced the catalytic activity and syndiotacticity of theproduced PS. The activities of catalyst 4 increase from 1.84×10~6 to 3.26×10~6 gPS/molTi·h with the increase of T_p from60℃ to 80℃ and the syndiotacticities of the produced s-PS also increase slightly. Then, both the catalytic activity and thesyndiotacticity of PS decrease at T_p of 90℃.
基金Major Science and Technology Projects of Hainan Province(ZDKJ2019009)Research Project of Ji’nan Microecological Biomedicine Shandong Labora-tory(JNL-2022002A and JNL-2022023C)+3 种基金Public Projects of Zhe-jiang Province(LGF21H030006)Research Unit Project of Chinese Academy of Medical Sciences(2019-I2M-5-030)the National Natu-ral Science Foundation of China(81721091,62073211)the Na-tional S&T Major Project for Infectious Diseases(2017ZX10203205).
文摘Introduction Organ transplantation increases survival and improves qual-ity of life to many patients with end-stage organ failure.Or-gan shortage is a worldwide problem that restricts organ trans-plantation[1].Organ procurement and preservation as well as ischemia-reperfusion injury(IRI)after transplantation are the im-portant factors affecting prognosis of recipients.Since the de-velopment of organ transplantation technology in the 20th cen-tury,organ protection technology has been a most promising con-cept in this field.Organ preservation solutions such as the Collins solution,University of Wisconsin(UW)solution,and histidine-tryptophan-ketoglutarate(HTK)solution were developed sequen-tially[2],which developed rapidly in static cold storage(SCS)tech-niques.SCS remains the standard preservation technique for organ transplantation[2].
基金grants from the National Natural Science Foundation of China(Nos.81672028 and 81371788)the Outstanding Scientific Fund of Shengjing Hospital.
文摘Background:Natural anti-sense transcripts(NATs),which are transcribed from the complementary DNA strand of annotated genes,exert regulatory function of gene expression.Increasing studies recognized anti-sense transcription widespread throughout human cytomegalovirus(HCMV)genome,whereas the anti-sense transcription of RNA1.2 gene locus has never been investigated.In this study,the transcription of the RNA1.2 anti-sense strand was investigated in clinically isolated HCMV strain.Methods:Strand-specific high-through RNA-sequencing(RNA-seq)was performed to find possible anti-sense transcripts(ASTs).For analyzing and visualization of RNA-seq data sets,Integrative Genomics Viewer software was applied.To confirm these possibilities,Northern blotting and rapid amplification of cDNA ends(RACE)were used.Results:Transcription of the opposite strand of RNA1.2 gene locus was detected by RNA-sequencing using RNAs extracted from human embryonic lung fibroblasts infected with HCMV clinical isolate HAN.At least three HCMV NATs,named RNA1.2 AST 1,RNA1.2 AST2,and RNA 1.2 AST3,were characterized by Northern blotting and RACE analyses.These RNA1.2 ASTs orientated from the complementary strand of RNA1.2 locus during the late phase of HCMV infection.The 5'-and 3'-termini of these transcripts were located within the opposite sequence of the predicted RNA1.2 gene.Conclusion:A cluster of novel NATs was transcribed from the opposite sequence of the HCMV RNA 1.2 gene region.
