Stem cell-based tissue engineering has provided a promising platform for repairing of bone defects.However,the use of exogenous bone marrow mesenchymal stem cells(BMSCs)still faces many challenges such as limited sour...Stem cell-based tissue engineering has provided a promising platform for repairing of bone defects.However,the use of exogenous bone marrow mesenchymal stem cells(BMSCs)still faces many challenges such as limited sources and potential risks.It is important to develop new approach to effectively recruit endogenous BMSCs and capture them for in situ bone regeneration.Here,we designed an acoustically responsive scaffold(ARS)and embedded it into SDF-1/BMP-2 loaded hydrogel to obtain biomimetic hydrogel scaffold complexes(BSC).The SDF-1/BMP-2 cytokines can be released on demand from the BSC implanted into the defected bone via pulsed ultrasound(p-US)irradiation at optimized acoustic parameters,recruiting the endogenous BMSCs to the bone defected or BSC site.Accompanied by the daily p-US irradiation for 14 days,the alginate hydrogel was degraded,resulting in the exposure of ARS to these recruited host stem cells.Then another set of sinusoidal continuous wave ultrasound(s-US)irradiation was applied to excite the ARS intrinsic resonance,forming highly localized acoustic field around its surface and generating enhanced acoustic trapping force,by which these recruited endogenous stem cells would be captured on the scaffold,greatly promoting them to adhesively grow for in situ bone tissue regeneration.Our study provides a novel and effective strategy for in situ bone defect repairing through acoustically manipulating endogenous BMSCs.展开更多
Cooperative activation is critical for the applications of synthetic biology in mammalian cells.In this study,we have developed cooperative transcription factor by fusing oligomerization domain in mammalian cells.Firs...Cooperative activation is critical for the applications of synthetic biology in mammalian cells.In this study,we have developed cooperative transcription factor by fusing oligomerization domain in mammalian cells.Firstly,we demonstrated that two oligomerized domains(CI434 and CI)successfully improved transcription factor cooperativity in bacterial cells but failed to increase cooperativity in mammalian cells,possibly because the additional mammalian activation domain disrupted their oligomerization capability.Therefore,we chose a different type of oligomerized domain(CarHC),whose ability to oligomerize is not dependent on its C-terminal domains,to fuse with a transcription factor(RpaR)and activation domain(VTR3),forming a potential cooperative transcription activator RpaR-CarH-VTR3 for mammalian regulatory systems.Compared with RpaR-VTR3,the cooperativity of RpaR-CarH-VTR3 was significantly improved with higher Hill coefficient and a narrower input range in the inducible switch system in mammalian cells.Moreover,a mathematical model based on statistical mechanics model was developed and the simulation results supported the hypothesis that the tetramer of the CarH domain in mammalian cells was the reason for the cooperative capacity of RpaR-CarH-VTR3.展开更多
The application of the valuable natural product thaxtomin A,a potent bioherbicide from the potato scab pathogenic Streptomyces strains,has been greatly hindered by the low yields from its native producers.Here,we deve...The application of the valuable natural product thaxtomin A,a potent bioherbicide from the potato scab pathogenic Streptomyces strains,has been greatly hindered by the low yields from its native producers.Here,we developed an orthogonal transcription system,leveraging extra-cytoplasmic function(ECF)sigma(σ)factor 17(ECF17)and its cognate promoter Pecf17,to express the thaxtomin gene cluster and improve the production of thaxtomin A.The minimal Pecf17 promoter was determined,and a Pecf17 promoter library with a wide range of strengths was constructed.Furthermore,a cumate inducible system was developed for precise temporal control of the ECF17 transcription system in S.venezuelae ISP5230.Theoretically,the switchable ECF17 transcription system could reduce the unwanted influences from host and alleviate the burdens introduced by overexpression of heterologous genes.The yield of thaxtomin A was significantly improved to 202.1±15.3μg/mL using the switchable ECF17 transcription system for heterologous expression of the thaxtomin gene cluster in S.venezuelae ISP5230.Besides,the applicability of this transcription system was also tested in Streptomyces albus J1074,and the titer of thaxtomin A was raised to as high as 239.3±30.6μg/mL.Therefore,the inducible ECF17 transcription system could serve as a complement of the generally used transcription systems based on strong native constitutive promoters and housekeepingσfactors for the heterologous expression of valuable products in diverse Streptomyces hosts.展开更多
The authors regret that following the publication of the original article,the authors noticed that Funds in Acknowledgements section was incorrect,in which a fund(No.2020YFA0906903)supporting most of experimental resu...The authors regret that following the publication of the original article,the authors noticed that Funds in Acknowledgements section was incorrect,in which a fund(No.2020YFA0906903)supporting most of experimental results of Dr.Xinmao Chen was missed by us.We sincerely apologize again for the oversight and appreciate your understanding in allowing us to correct this matter.展开更多
Bladder cancer(BC)is the most common malignant tumor of the genitourinary system.The age of individuals diagnosed with BC tends to decrease in recent years.A variety of standard therapeutic options are available for t...Bladder cancer(BC)is the most common malignant tumor of the genitourinary system.The age of individuals diagnosed with BC tends to decrease in recent years.A variety of standard therapeutic options are available for the clinical management of BC,but limitations exist.It is difficult to surgically eliminate small lesions,while radiation and chemotherapy damage normal tissues,leading to severe side effects.Therefore,new approaches are required to improve the efficacy and specificity of BC treatment.Synthetic biology is a field emerging in the last decade that refers to biological elements,devices,and materials that are artificially synthesized according to users’needs.In this review,we discuss how to utilize genetic elements to regulate BC-related gene expression periodically and quantitatively to inhibit the initiation and progression of BC.In addition,the design and construction of gene circuits to distinguish cancer cells from normal cells to kill the former but spare the latter are elaborated.Then,we introduce the development of genetically modified T cells for targeted attacks on BC.Finally,synthetic nanomaterials specializing in detecting and killing BC cells are detailed.This review aims to describe the innovative details of the clinical diagnosis and treatment of BC from the perspective of synthetic biology.展开更多
Background:The concept of phase separation has been used to describe and interpret physicochemical phenomena in biological systems for decades.Many intracellular macromolecules undergo phase separation,where it plays ...Background:The concept of phase separation has been used to describe and interpret physicochemical phenomena in biological systems for decades.Many intracellular macromolecules undergo phase separation,where it plays important roles in gene regulation,cellular signaling,metabolic reactions and so on,due to its unique dynamic properties and biological effects.As the noticeable importance of phase separation,pioneer researchers have explored the possibility to introduce the synthetically engineered phase separation for applicable cell function.Results:In this article,we illustrated the application value of phase separation in synthetic biology.We described main states of phase separation in detail,summarized some ways to implement synthetic condensates and several methods to regulate phase separation,and provided a substantial amount of identical examples to illuminate the applications and perspectives of phase separation in synthetic biology.Conclusions:Multivalent interactions implement phase separation in synthetic biology.Small molecules,light control and spontaneous interactions induce and regulate phase separation.The synthetic condensates are widely used in signal amplifications,designer orthogonally non-membrane-bound organelles,metabolic pathways,gene regulations,signaling transductions and controllable platforms.Studies on quantitative analysis,more standardized modules and precise spatiotemporal control of synthetic phase separation may promote the further development of this field.展开更多
基金National Key R&D Program of China(2020YFA0908800)National Natural Science Foundation of China(81871376,32171365,82071927,81771853,81571674)+6 种基金Guangzhou Science and Technology Program Project(202002030104,202102080128,202201020284)Talent Research Foundation of Guangdong Second Provincial General Hospital(YN-2018-002)Youth Research Foundation of Guangdong Second Provincial General Hospital(YQ-2019-011)The science foundation of Guangdong Second Provincial General Hospital(TJGC-2021002)Natural Science Foundation of Guangdong Province(2021A1515011260,2018A030313824)Shenzhen Science and Technology Innovation Committee(JCYJ20190812171820731)Research Project of Traditional Chinese Medicine Bureau of Guangdong Provincial.
文摘Stem cell-based tissue engineering has provided a promising platform for repairing of bone defects.However,the use of exogenous bone marrow mesenchymal stem cells(BMSCs)still faces many challenges such as limited sources and potential risks.It is important to develop new approach to effectively recruit endogenous BMSCs and capture them for in situ bone regeneration.Here,we designed an acoustically responsive scaffold(ARS)and embedded it into SDF-1/BMP-2 loaded hydrogel to obtain biomimetic hydrogel scaffold complexes(BSC).The SDF-1/BMP-2 cytokines can be released on demand from the BSC implanted into the defected bone via pulsed ultrasound(p-US)irradiation at optimized acoustic parameters,recruiting the endogenous BMSCs to the bone defected or BSC site.Accompanied by the daily p-US irradiation for 14 days,the alginate hydrogel was degraded,resulting in the exposure of ARS to these recruited host stem cells.Then another set of sinusoidal continuous wave ultrasound(s-US)irradiation was applied to excite the ARS intrinsic resonance,forming highly localized acoustic field around its surface and generating enhanced acoustic trapping force,by which these recruited endogenous stem cells would be captured on the scaffold,greatly promoting them to adhesively grow for in situ bone tissue regeneration.Our study provides a novel and effective strategy for in situ bone defect repairing through acoustically manipulating endogenous BMSCs.
基金supported by Ministry of Science and Technology of China [No.2021YFA0910700,2021YFF1200500,2020YFA0907101]the Natural Science Foundation of China [No.12090050,12090054,32071412]+1 种基金the Chinese Academy of Sciences [No.QYZDB-SSW-SMC050]CAS Youth Interdisciplinary Team and the Shenzhen Science and Technology Innovation Committee [No.JCYJ20180507182241844,JCHZ20200005,DWKF20190009].
文摘Cooperative activation is critical for the applications of synthetic biology in mammalian cells.In this study,we have developed cooperative transcription factor by fusing oligomerization domain in mammalian cells.Firstly,we demonstrated that two oligomerized domains(CI434 and CI)successfully improved transcription factor cooperativity in bacterial cells but failed to increase cooperativity in mammalian cells,possibly because the additional mammalian activation domain disrupted their oligomerization capability.Therefore,we chose a different type of oligomerized domain(CarHC),whose ability to oligomerize is not dependent on its C-terminal domains,to fuse with a transcription factor(RpaR)and activation domain(VTR3),forming a potential cooperative transcription activator RpaR-CarH-VTR3 for mammalian regulatory systems.Compared with RpaR-VTR3,the cooperativity of RpaR-CarH-VTR3 was significantly improved with higher Hill coefficient and a narrower input range in the inducible switch system in mammalian cells.Moreover,a mathematical model based on statistical mechanics model was developed and the simulation results supported the hypothesis that the tetramer of the CarH domain in mammalian cells was the reason for the cooperative capacity of RpaR-CarH-VTR3.
基金supported by the National Key Research and Development Program of China[2018YFA0900700]Natural Science Foundation of China[31900901 and 31500069]+1 种基金the Chinese Academy of Sciences[No.QYZDB-SSW-SMC050,No.XDPB1801 of the Strategic Priority Research Program]the Shenzhen Science and Technology Innovation Committee[No.JCYJ20180507182241844,JCHZ20200005,DWKF20190009].
文摘The application of the valuable natural product thaxtomin A,a potent bioherbicide from the potato scab pathogenic Streptomyces strains,has been greatly hindered by the low yields from its native producers.Here,we developed an orthogonal transcription system,leveraging extra-cytoplasmic function(ECF)sigma(σ)factor 17(ECF17)and its cognate promoter Pecf17,to express the thaxtomin gene cluster and improve the production of thaxtomin A.The minimal Pecf17 promoter was determined,and a Pecf17 promoter library with a wide range of strengths was constructed.Furthermore,a cumate inducible system was developed for precise temporal control of the ECF17 transcription system in S.venezuelae ISP5230.Theoretically,the switchable ECF17 transcription system could reduce the unwanted influences from host and alleviate the burdens introduced by overexpression of heterologous genes.The yield of thaxtomin A was significantly improved to 202.1±15.3μg/mL using the switchable ECF17 transcription system for heterologous expression of the thaxtomin gene cluster in S.venezuelae ISP5230.Besides,the applicability of this transcription system was also tested in Streptomyces albus J1074,and the titer of thaxtomin A was raised to as high as 239.3±30.6μg/mL.Therefore,the inducible ECF17 transcription system could serve as a complement of the generally used transcription systems based on strong native constitutive promoters and housekeepingσfactors for the heterologous expression of valuable products in diverse Streptomyces hosts.
文摘The authors regret that following the publication of the original article,the authors noticed that Funds in Acknowledgements section was incorrect,in which a fund(No.2020YFA0906903)supporting most of experimental results of Dr.Xinmao Chen was missed by us.We sincerely apologize again for the oversight and appreciate your understanding in allowing us to correct this matter.
基金supported by the National Key Research and Development Program of China(No.2018YFA0902802).
文摘Bladder cancer(BC)is the most common malignant tumor of the genitourinary system.The age of individuals diagnosed with BC tends to decrease in recent years.A variety of standard therapeutic options are available for the clinical management of BC,but limitations exist.It is difficult to surgically eliminate small lesions,while radiation and chemotherapy damage normal tissues,leading to severe side effects.Therefore,new approaches are required to improve the efficacy and specificity of BC treatment.Synthetic biology is a field emerging in the last decade that refers to biological elements,devices,and materials that are artificially synthesized according to users’needs.In this review,we discuss how to utilize genetic elements to regulate BC-related gene expression periodically and quantitatively to inhibit the initiation and progression of BC.In addition,the design and construction of gene circuits to distinguish cancer cells from normal cells to kill the former but spare the latter are elaborated.Then,we introduce the development of genetically modified T cells for targeted attacks on BC.Finally,synthetic nanomaterials specializing in detecting and killing BC cells are detailed.This review aims to describe the innovative details of the clinical diagnosis and treatment of BC from the perspective of synthetic biology.
基金supported by the National Key Basic Research Program of China 2018YFA0902800(P.W.)the National Natural Science Foundation of China 31470819(P.W.)31622022(P.W.).
文摘Background:The concept of phase separation has been used to describe and interpret physicochemical phenomena in biological systems for decades.Many intracellular macromolecules undergo phase separation,where it plays important roles in gene regulation,cellular signaling,metabolic reactions and so on,due to its unique dynamic properties and biological effects.As the noticeable importance of phase separation,pioneer researchers have explored the possibility to introduce the synthetically engineered phase separation for applicable cell function.Results:In this article,we illustrated the application value of phase separation in synthetic biology.We described main states of phase separation in detail,summarized some ways to implement synthetic condensates and several methods to regulate phase separation,and provided a substantial amount of identical examples to illuminate the applications and perspectives of phase separation in synthetic biology.Conclusions:Multivalent interactions implement phase separation in synthetic biology.Small molecules,light control and spontaneous interactions induce and regulate phase separation.The synthetic condensates are widely used in signal amplifications,designer orthogonally non-membrane-bound organelles,metabolic pathways,gene regulations,signaling transductions and controllable platforms.Studies on quantitative analysis,more standardized modules and precise spatiotemporal control of synthetic phase separation may promote the further development of this field.
