BACKGROUND The most common causes of scrotal enlargement in patients include primary tumor of the scrotum,inflammation,hydrocele of the tunica vaginalis,and indirect inguinal hernia;scrotal enlargement caused by exter...BACKGROUND The most common causes of scrotal enlargement in patients include primary tumor of the scrotum,inflammation,hydrocele of the tunica vaginalis,and indirect inguinal hernia;scrotal enlargement caused by external tumors of the scrotum is rare.The patient had both a greater omentum tumor and an inguinal hernia,and the tumor protruded into the scrotum through the hernia sac,which is even rarer.Moreover,omental tumors are mostly metastatic,and primary omental fibroma is rare.CASE SUMMARY Here,we report a rare case of a 25-year-old young man with scrotal enlargement and pain for 3 months.Preoperative examination and multidisciplinary discu-ssions considered intra-abdominal tumor displacement and inguinal hernia,and intraoperative exploration confirmed that the greater omentum tumor protruded into the scrotum.Therefore,tumor resection and tension-free inguinal hernia repair were performed.The final diagnosis was benign fibroma of the greater omentum accompanied by an indirect inguinal hernia.CONCLUSION This unusual presentation of a common inguinal hernia disease illustrates the necessity of performing detailed history taking,physical examination,and imaging before surgery.展开更多
Background Myocardial injury caused by microvascular obstruction(MVO)is characterized by persistent ischemia/hypoxia(IH)of cardiomyocytes after microembolization.Autophagy and Egr-1 were closely associated with variou...Background Myocardial injury caused by microvascular obstruction(MVO)is characterized by persistent ischemia/hypoxia(IH)of cardiomyocytes after microembolization.Autophagy and Egr-1 were closely associated with various cardiovascular diseases,including MVO.Bim and Beclin-1 are the important genes for autophagy and apoptosis.We aimed to explore whether the Egr-1/Bim/Beclin-1 pathway is involved in regulating autophagy and apoptosis in IH-exposed cardiomyocytes.Methods Neonatal rat cardiomyocytes exposed to the IH environment in vitro were transfected with lentivirus expressing Egr-1 or Egr-1 sh RNA,or further treated with 3-methyladenine(3-MA).The expressions of autophagy and apoptosis-associated genes were evaluated using RT-q PCR and Western blots assays.Autophagic vacuoles and autophagic flux were detected by transmission electron microscopy(TEM)and confocal microscope,respectively.Cell injury was assessed by lactate dehydrogenase(LDH)leakage,and apoptosis was determined by flow cytometry.Results IH exposure elevated Egr-1 and Bim expressions,and decreased Beclin-1 expression in rat cardiomyocytes.Egr-1 overexpression in IH-exposed cardiomyocytes significantly up-regulated the levels of Egr-1 and Bim,and down-regulated the level of Beclin-1.Egr-1 knockdown resulted in down-regulated expressions of Egr-1 and Bim,as well as up-regulated expression of Beclin-1.In addition,Egr-1 knockdown induced autophagy was suppressed by 3-MA treatments.TEM and autophagic flux experiments also confirmed that Egr-1 inhibited autophagy progression in IH-exposed cardiomyocytes.Egr-1 suppression protected cardiomyocytes from IH-induced injury,as evidenced by the positive correlations between Egr-1 expression and LDH leakage or apoptosis index in IH-exposed cardiomyocytes.Conclusions IH-induced cardiomyocyte autophagy and apoptosis are regulated by the Egr-1/Bim/Beclin-1 pathway,which is a potential target for treating cardiomyocyte injury caused by MVO in the IH environment.展开更多
BACKGROUND Primary bone lymphoma(PBL)is an uncommon extranodal disease that represents approximately 1%-3%of lymphomas.Anaplastic lymphoma kinase(ALK)positive anaplastic large-cell lymphoma(ALCL)is an extremely rare t...BACKGROUND Primary bone lymphoma(PBL)is an uncommon extranodal disease that represents approximately 1%-3%of lymphomas.Anaplastic lymphoma kinase(ALK)positive anaplastic large-cell lymphoma(ALCL)is an extremely rare type of PBL.The aim of this report is describe the symptoms,diagnosis,and treatment of primary bone ALK-positive ALCL.CASE SUMMARY A 66-year-old man presented to our hospital with neck and shoulder pain and intermittent fever that lasted for 1 mo.After extensive evaluation,positron emission tomography-computed tomography(CT)examination showed multiple osteolytic bone lesions without other sites lesions.CT-guided biopsy of the T10 vertebral body was performed,and the pathology results showed that neoplastic cells were positive for ALK-1,CD30,and CD3.A diagnosis of primary bone ALK positive ALCL was ultimately made.The patient was in partial response after four cycle soft cyclophosphamide,doxorubicin,vincristine,and prednisone chemotherapy,and we planned to repeat the biopsy and radiological examination after completion of the fifth cycle of therapy.CONCLUSION Primary bone ALK positive ALCL is a rare disease and physicians should keep in mind that ALCL can present with isolated osseous involvement without nodal involvement,and lymphoma should be considered in the differential diagnosis of primary bone lesions.展开更多
BACKGROUND Liver cancer is one of the most highly malignant cancers,characterized by easy metastasis and chemoradiotherapy resistance.Emerging evidence indicates that long noncoding RNAs(LncRNAs),including Lnc524369,a...BACKGROUND Liver cancer is one of the most highly malignant cancers,characterized by easy metastasis and chemoradiotherapy resistance.Emerging evidence indicates that long noncoding RNAs(LncRNAs),including Lnc524369,are highly involved in the initiation,progression,radioresistance,and chemoresistance of hepatocellular carcinoma(HCC).However,the function of Lnc524369 remains unclear.AIM To explore the function of Lnc524369 in HCC.METHODS To investigate the effect of Lnc524369,tissue from 41 HCC patients were analyzed using CCK8,migration,and invasion assays.Lnc524369 and YWHAZ(also named 14-3-3ζ)mRNA were detected by qPCR,and YWHAZ and RAF1 proteins were detected by western blot in liver cancer cell lines and human HCC tissues.The Cancer Cell Line Encyclopedia(CCLE)databases,STRING database,Human Protein Atlas database,and the TCGA database were used for bioinformatic analysis.RESULTS Lnc524369 was significantly upregulated in the nucleus of liver cancer cells and human HCC tissues.Overexpression of Lnc524369 was associated with the proliferation,migration,and invasion of liver cancer cells.YWHAZ and RAF1 proteins and YWHAZ mRNA were overexpressed in liver cancer,which could be attenuated by overexpression of Lnc524369.Lnc524369 and its downstream target YWHAZ and RAF1 proteins were negatively associated with overall survival time.CONCLUSION Lnc524369 might be a promising target of HCC as it can enhance liver cancer progression and decrease the overall survival time of HCC by activating the YWHAZ/RAF1 pathway.展开更多
BACKGROUND Diffuse large B-cell lymphoma(DLBCL)is a common non-Hodgkin's lymphoma.R-CHOP is a protocol for long-term chemotherapy for DLBCL patients.Longterm chemotherapy can lead to low immunity and increase the ...BACKGROUND Diffuse large B-cell lymphoma(DLBCL)is a common non-Hodgkin's lymphoma.R-CHOP is a protocol for long-term chemotherapy for DLBCL patients.Longterm chemotherapy can lead to low immunity and increase the risk of opportunistic pathogen infections in immunocompromised patients.CASE SUMMARY We report a case of coinfection with Pneumocystis jirovecii(P.jirovecii)and Legionella pneumophila(L.pneumophila)in a patient with DLBCL.The patient was a 40-year-old female who was diagnosed with DLBCL and was admitted due to pulmonary infection.P.jirovecii and L.pneumophila were detected in her bronchoalveolar lavage fluid by hexamine silver staining,isothermal amplification and metagenomic sequencing.CONCLUSION To the best of our knowledge,this is the first case of P.jirovecii and L.pneumophila coinfection found in a DLBCL patient.Clinicians should be aware of the risk of complicated infection in patients undergoing long-term chemotherapy.展开更多
BACKGROUND Inborn error of bile acid synthesis type 4 is a peroxisomal disease with impaired bile acid synthesis caused by a-methylacyl-CoA racemase(AMACR)gene mutation.The disease is usually found in children with mi...BACKGROUND Inborn error of bile acid synthesis type 4 is a peroxisomal disease with impaired bile acid synthesis caused by a-methylacyl-CoA racemase(AMACR)gene mutation.The disease is usually found in children with mild to severe liver disease,cholestasis and poor fat-soluble vitamin absorption.At present,there is no report of inborn errors of bile acid synthesis type 4 in adults with liver disease and poor fat-soluble vitamin absorption.CASE SUMMARY A 71-year-old man was hospitalized in our department for recurrent liver dysfunction.The clinical manifestations were chronic liver disease and yellow skin and sclera.Serum transaminase,bilirubin and bile acid were abnormally increased;and fat-soluble vitamins decreased.Liver cirrhosis and ascites were diagnosed by computed tomography.The patient had poor coagulation function and ascites and did not undergo liver puncture.Genetic testing showed AMACR gene missense mutation.The patient was diagnosed with inborn error of bile acid synthesis type 4.He was treated with ursodeoxycholic acid,liver protection and vitamin supplementation,and jaundice of the skin and sclera was reduced.The indicators of liver function and the quality of life were significantly improved.CONCLUSION When adults have recurrent liver function abnormalities,physicians should be alert to genetic diseases and provide timely treatment.展开更多
General relativity has been very successful since its proposal more than a century ago.However,various cosmological observations and theoretical consistency still motivate us to explore extended gravity theories.Hornd...General relativity has been very successful since its proposal more than a century ago.However,various cosmological observations and theoretical consistency still motivate us to explore extended gravity theories.Horndeski gravity stands out as one attractive theory by introducing only one scalar field.Here we formulate the post-Newtonian effective field theory of Horndeski gravity and investigate the conservative dynamics of inspiral compact binary systems.We calculate the leading effective Lagrangian for a compact binary and obtain the periastron advance per period.In particular,we apply our analytical calculation to two binary systems,PSR B 1534+12 and PSR J0737-3039,and constrain the relevant model parameters.This theoretical framework can also be systematically extended to higherorders.展开更多
Synthetic hydrogels are widely used as biomimetic in vitro model systems to understand how cells respond to complex microenvironments. The mechanical properties of hydrogels are deterministic for many cellular behavio...Synthetic hydrogels are widely used as biomimetic in vitro model systems to understand how cells respond to complex microenvironments. The mechanical properties of hydrogels are deterministic for many cellular behaviors, including cell migration, spreading, and differentiation. However, it remains a major challenge to engineer hydrogels that recapture the dynamic mechanical properties of native extracellular matrices. Here, we provide a new hydrogel platform with spatiotemporally tunable mechanical properties to assay and define cellular behaviors under light. The change in the mechanical properties of the hydrogel is effected by a photo-induced switch of the cross-linker fluorescent protein, Dronpa145N, between the tetrameric and monomeric states, which causes minimal changes to the chemical properties of the hydrogel. The mechanical properties can be rapidly and reversibly tuned for multiple cycles using visible light, as confirmed by rheological measurements and atomic force microscopy- based nano-indentation. We further demonstrated real-time and reversible modulation of cell migration behaviors on the hydrogels through photo-induced stiffness switching, with minimal invasion to the cultured cells. Hydrogels with a programmable mechanical history and a spatially defined mechanical hierarchy might serve as an ideal model system to better understand complex cellular functions.展开更多
Information-rich molecules provide opportunities for evolution.Genetically engineered materials are superior in that their properties are coded within genetic sequences and could be fine-tuned.In this review,we elabor...Information-rich molecules provide opportunities for evolution.Genetically engineered materials are superior in that their properties are coded within genetic sequences and could be fine-tuned.In this review,we elaborate the concept of genetically engineered materials(GEMs)using examples ranging from engineered protein materials to engineered living materials.Proteinbased materials are the materials of choice by nature.Recent progress in protein engineering has led to opportunities to tune their sequences for optimal material performance.Proteins also play a central role in living materials where they act in concert with other biological components as well as nonbiological cofactors,giving rise to living features.While the existing GEMs are often limited to those constructed by building blocks of biological origin,being genetically engineerable does not preclude nonbiologic or synthetic materials,the latter of which have yet to be fully explored.展开更多
Herein,we report the facile conjugation between proteins and water-soluble [60]fullerene derivatives(DC_(60)) under native conditions using SpyTag as a reactive handle.Water-soluble [60] fullerene derivatives were fir...Herein,we report the facile conjugation between proteins and water-soluble [60]fullerene derivatives(DC_(60)) under native conditions using SpyTag as a reactive handle.Water-soluble [60] fullerene derivatives were first prepared via sequential Bingel-Hirsch reaction and "clicked" with SpyTag to give DC_(60)-SpyTag for native conjugation with proteins by the highly efficient SpyTag-SpyCatcher chemistry.The bioconjugation was confirmed by MALDI-TOF MS spectra and SDS-PAGE analysis.The TEM and UVvis spectroscopic study further revealed that the DC_(60) could alter the optical performance and induce aggregation of the target proteins.It thus provides a general and robust method for modifying proteins with C_(60) derivatives and could potentially be adapted for native conjugation between proteins and other nonbiological motifs as well.展开更多
Genetically encoded covalent peptide tagging tools such as the SpyTag/SpyCatcher reactive pair,have been demonstrated versatile and useful for protein modification.Herein,we present a superpositively charged SpyCatche...Genetically encoded covalent peptide tagging tools such as the SpyTag/SpyCatcher reactive pair,have been demonstrated versatile and useful for protein modification.Herein,we present a superpositively charged SpyCatcher bearing a theoretical net charge of+21 capable of accomplishing multiple unrelated independent tasks to enrich this toolbox and cultivate new functions.The SpyCatcher(+21)possessed stimuli-responsive reactivity toward SpyTag and could serve as a potent and general platform for the delivery of proteins,including RNaseAinto HeLa cells.Remarkably,the delivered RNase A caused substantial proliferation inhibition toward HeLa cells.In addition,the superpositively charged SpyCatcher could form coacervate with plasmid DNA for further study of gene delivery and liquid–liquid phase separation.These findings demonstrate the robustness of the SpyTag/SpyCatcher structure against surface mutation and the prospect of applying supercharging technology on diverse functional proteins to create moonlighting proteins.展开更多
In the electromagnetic channel,chaotic gravitational lensing is a peculiar phenomenon in strong gravita-tional lensing.In this study,we analyze the properties and emergence of chaotic gravitational lensing in the Mank...In the electromagnetic channel,chaotic gravitational lensing is a peculiar phenomenon in strong gravita-tional lensing.In this study,we analyze the properties and emergence of chaotic gravitational lensing in the Manko-Novikov black hole spacetime.Aiming to better understand the underlying physics,we elaborate on the boundaries of the accessible region through analyses of the contours of the effective potentials.The latter is associated with the two roots of a quadratic equation.In particular,we explore its interplay with an ergoregion,which leads to specific features of the effective potentials,such as the emergence of a cuspy edge and the formation of a pocket,which serve as static constraints on the geodesics.Additionally,we investigate the properties of the radial and angular accelerations at the turning points in photon trajectories.The accelerations are further examined and may provide kinematic constraints on the geodesics,as argued herein.It is concluded that the onset of the chaotic lensing is significantly related to both con-straints;as a result,an arbitrary slight deviation in the incident photon is significantly amplified during evolution through an extensive period,demonstrating the complexity in the highly nonlinear deterministic gravitational system.展开更多
文摘BACKGROUND The most common causes of scrotal enlargement in patients include primary tumor of the scrotum,inflammation,hydrocele of the tunica vaginalis,and indirect inguinal hernia;scrotal enlargement caused by external tumors of the scrotum is rare.The patient had both a greater omentum tumor and an inguinal hernia,and the tumor protruded into the scrotum through the hernia sac,which is even rarer.Moreover,omental tumors are mostly metastatic,and primary omental fibroma is rare.CASE SUMMARY Here,we report a rare case of a 25-year-old young man with scrotal enlargement and pain for 3 months.Preoperative examination and multidisciplinary discu-ssions considered intra-abdominal tumor displacement and inguinal hernia,and intraoperative exploration confirmed that the greater omentum tumor protruded into the scrotum.Therefore,tumor resection and tension-free inguinal hernia repair were performed.The final diagnosis was benign fibroma of the greater omentum accompanied by an indirect inguinal hernia.CONCLUSION This unusual presentation of a common inguinal hernia disease illustrates the necessity of performing detailed history taking,physical examination,and imaging before surgery.
基金supported by the National Natural Science Foundation of China(Grant No.81770346)the Innovation Project of Guangxi Graduate Education(Grant No.YCBZ2019040)。
文摘Background Myocardial injury caused by microvascular obstruction(MVO)is characterized by persistent ischemia/hypoxia(IH)of cardiomyocytes after microembolization.Autophagy and Egr-1 were closely associated with various cardiovascular diseases,including MVO.Bim and Beclin-1 are the important genes for autophagy and apoptosis.We aimed to explore whether the Egr-1/Bim/Beclin-1 pathway is involved in regulating autophagy and apoptosis in IH-exposed cardiomyocytes.Methods Neonatal rat cardiomyocytes exposed to the IH environment in vitro were transfected with lentivirus expressing Egr-1 or Egr-1 sh RNA,or further treated with 3-methyladenine(3-MA).The expressions of autophagy and apoptosis-associated genes were evaluated using RT-q PCR and Western blots assays.Autophagic vacuoles and autophagic flux were detected by transmission electron microscopy(TEM)and confocal microscope,respectively.Cell injury was assessed by lactate dehydrogenase(LDH)leakage,and apoptosis was determined by flow cytometry.Results IH exposure elevated Egr-1 and Bim expressions,and decreased Beclin-1 expression in rat cardiomyocytes.Egr-1 overexpression in IH-exposed cardiomyocytes significantly up-regulated the levels of Egr-1 and Bim,and down-regulated the level of Beclin-1.Egr-1 knockdown resulted in down-regulated expressions of Egr-1 and Bim,as well as up-regulated expression of Beclin-1.In addition,Egr-1 knockdown induced autophagy was suppressed by 3-MA treatments.TEM and autophagic flux experiments also confirmed that Egr-1 inhibited autophagy progression in IH-exposed cardiomyocytes.Egr-1 suppression protected cardiomyocytes from IH-induced injury,as evidenced by the positive correlations between Egr-1 expression and LDH leakage or apoptosis index in IH-exposed cardiomyocytes.Conclusions IH-induced cardiomyocyte autophagy and apoptosis are regulated by the Egr-1/Bim/Beclin-1 pathway,which is a potential target for treating cardiomyocyte injury caused by MVO in the IH environment.
基金Supported by National Science and Technology Major Subproject of China,No.2018ZX10302205-002Chinese Foundation for Hepatitis Prevention and Control-Tianqing Liver Disease Research Fund Subject,No.TQGB2020168.
文摘BACKGROUND Primary bone lymphoma(PBL)is an uncommon extranodal disease that represents approximately 1%-3%of lymphomas.Anaplastic lymphoma kinase(ALK)positive anaplastic large-cell lymphoma(ALCL)is an extremely rare type of PBL.The aim of this report is describe the symptoms,diagnosis,and treatment of primary bone ALK-positive ALCL.CASE SUMMARY A 66-year-old man presented to our hospital with neck and shoulder pain and intermittent fever that lasted for 1 mo.After extensive evaluation,positron emission tomography-computed tomography(CT)examination showed multiple osteolytic bone lesions without other sites lesions.CT-guided biopsy of the T10 vertebral body was performed,and the pathology results showed that neoplastic cells were positive for ALK-1,CD30,and CD3.A diagnosis of primary bone ALK positive ALCL was ultimately made.The patient was in partial response after four cycle soft cyclophosphamide,doxorubicin,vincristine,and prednisone chemotherapy,and we planned to repeat the biopsy and radiological examination after completion of the fifth cycle of therapy.CONCLUSION Primary bone ALK positive ALCL is a rare disease and physicians should keep in mind that ALCL can present with isolated osseous involvement without nodal involvement,and lymphoma should be considered in the differential diagnosis of primary bone lesions.
基金the Medical and Health Science and Technology Project of Zhejiang Province(No.2021KY043)Chinese Foundation for Hepatitis Prevention and Control-TianQing Liver Disease Research Fund Subject(No.TQGB2020168).
文摘BACKGROUND Liver cancer is one of the most highly malignant cancers,characterized by easy metastasis and chemoradiotherapy resistance.Emerging evidence indicates that long noncoding RNAs(LncRNAs),including Lnc524369,are highly involved in the initiation,progression,radioresistance,and chemoresistance of hepatocellular carcinoma(HCC).However,the function of Lnc524369 remains unclear.AIM To explore the function of Lnc524369 in HCC.METHODS To investigate the effect of Lnc524369,tissue from 41 HCC patients were analyzed using CCK8,migration,and invasion assays.Lnc524369 and YWHAZ(also named 14-3-3ζ)mRNA were detected by qPCR,and YWHAZ and RAF1 proteins were detected by western blot in liver cancer cell lines and human HCC tissues.The Cancer Cell Line Encyclopedia(CCLE)databases,STRING database,Human Protein Atlas database,and the TCGA database were used for bioinformatic analysis.RESULTS Lnc524369 was significantly upregulated in the nucleus of liver cancer cells and human HCC tissues.Overexpression of Lnc524369 was associated with the proliferation,migration,and invasion of liver cancer cells.YWHAZ and RAF1 proteins and YWHAZ mRNA were overexpressed in liver cancer,which could be attenuated by overexpression of Lnc524369.Lnc524369 and its downstream target YWHAZ and RAF1 proteins were negatively associated with overall survival time.CONCLUSION Lnc524369 might be a promising target of HCC as it can enhance liver cancer progression and decrease the overall survival time of HCC by activating the YWHAZ/RAF1 pathway.
文摘BACKGROUND Diffuse large B-cell lymphoma(DLBCL)is a common non-Hodgkin's lymphoma.R-CHOP is a protocol for long-term chemotherapy for DLBCL patients.Longterm chemotherapy can lead to low immunity and increase the risk of opportunistic pathogen infections in immunocompromised patients.CASE SUMMARY We report a case of coinfection with Pneumocystis jirovecii(P.jirovecii)and Legionella pneumophila(L.pneumophila)in a patient with DLBCL.The patient was a 40-year-old female who was diagnosed with DLBCL and was admitted due to pulmonary infection.P.jirovecii and L.pneumophila were detected in her bronchoalveolar lavage fluid by hexamine silver staining,isothermal amplification and metagenomic sequencing.CONCLUSION To the best of our knowledge,this is the first case of P.jirovecii and L.pneumophila coinfection found in a DLBCL patient.Clinicians should be aware of the risk of complicated infection in patients undergoing long-term chemotherapy.
文摘BACKGROUND Inborn error of bile acid synthesis type 4 is a peroxisomal disease with impaired bile acid synthesis caused by a-methylacyl-CoA racemase(AMACR)gene mutation.The disease is usually found in children with mild to severe liver disease,cholestasis and poor fat-soluble vitamin absorption.At present,there is no report of inborn errors of bile acid synthesis type 4 in adults with liver disease and poor fat-soluble vitamin absorption.CASE SUMMARY A 71-year-old man was hospitalized in our department for recurrent liver dysfunction.The clinical manifestations were chronic liver disease and yellow skin and sclera.Serum transaminase,bilirubin and bile acid were abnormally increased;and fat-soluble vitamins decreased.Liver cirrhosis and ascites were diagnosed by computed tomography.The patient had poor coagulation function and ascites and did not undergo liver puncture.Genetic testing showed AMACR gene missense mutation.The patient was diagnosed with inborn error of bile acid synthesis type 4.He was treated with ursodeoxycholic acid,liver protection and vitamin supplementation,and jaundice of the skin and sclera was reduced.The indicators of liver function and the quality of life were significantly improved.CONCLUSION When adults have recurrent liver function abnormalities,physicians should be alert to genetic diseases and provide timely treatment.
基金Supported by National Key Research and Development Program of China (2021YFC2201901)and National Natural Science Foundation of China (12147103,11851302)。
文摘General relativity has been very successful since its proposal more than a century ago.However,various cosmological observations and theoretical consistency still motivate us to explore extended gravity theories.Horndeski gravity stands out as one attractive theory by introducing only one scalar field.Here we formulate the post-Newtonian effective field theory of Horndeski gravity and investigate the conservative dynamics of inspiral compact binary systems.We calculate the leading effective Lagrangian for a compact binary and obtain the periastron advance per period.In particular,we apply our analytical calculation to two binary systems,PSR B 1534+12 and PSR J0737-3039,and constrain the relevant model parameters.This theoretical framework can also be systematically extended to higherorders.
基金We thank Dr. W. Meng for his initial experiments on this project. This work is funded by the National Natural Science Foundation of China （Nos. 21522402, 21474003, 91427304, 11372279, 11572285, 11674153,11374148, and 11334004）, the Fundamental Research Funds for the Central Universities （Nos. 020414380070 and 020414380058）, the National Basic Research Program of China （Nos. 2012CB921801 and 2013CB834100） and the National High-tech R＆D Program of China （No. 2015AA020941）.
文摘Synthetic hydrogels are widely used as biomimetic in vitro model systems to understand how cells respond to complex microenvironments. The mechanical properties of hydrogels are deterministic for many cellular behaviors, including cell migration, spreading, and differentiation. However, it remains a major challenge to engineer hydrogels that recapture the dynamic mechanical properties of native extracellular matrices. Here, we provide a new hydrogel platform with spatiotemporally tunable mechanical properties to assay and define cellular behaviors under light. The change in the mechanical properties of the hydrogel is effected by a photo-induced switch of the cross-linker fluorescent protein, Dronpa145N, between the tetrameric and monomeric states, which causes minimal changes to the chemical properties of the hydrogel. The mechanical properties can be rapidly and reversibly tuned for multiple cycles using visible light, as confirmed by rheological measurements and atomic force microscopy- based nano-indentation. We further demonstrated real-time and reversible modulation of cell migration behaviors on the hydrogels through photo-induced stiffness switching, with minimal invasion to the cultured cells. Hydrogels with a programmable mechanical history and a spatially defined mechanical hierarchy might serve as an ideal model system to better understand complex cellular functions.
基金supported by the National Natural Science Foundation of China(21905001,21925102,21991132,92056118)the National Key R&D Program of China(2020YFA0908100)+5 种基金Beijing Municipal Natural Science Foundation(L182003)Beijing National Laboratory for Molecular Sciences(BNLMS-CXXM-202006)Guangdong Natural Science Foundation(GDST19EG22)the Science,Technology,and Innovation Commission of Shenzhen Municipality(JCYJ20190813094601656)Clinical Medicine Plus X project of Peking UniversityFundamental Research Funds for the Central Universities。
文摘Information-rich molecules provide opportunities for evolution.Genetically engineered materials are superior in that their properties are coded within genetic sequences and could be fine-tuned.In this review,we elaborate the concept of genetically engineered materials(GEMs)using examples ranging from engineered protein materials to engineered living materials.Proteinbased materials are the materials of choice by nature.Recent progress in protein engineering has led to opportunities to tune their sequences for optimal material performance.Proteins also play a central role in living materials where they act in concert with other biological components as well as nonbiological cofactors,giving rise to living features.While the existing GEMs are often limited to those constructed by building blocks of biological origin,being genetically engineerable does not preclude nonbiologic or synthetic materials,the latter of which have yet to be fully explored.
基金the financial support from the National Natural Science Foundation of China(Nos.21925102,21991132 and 21674003)supported by Beijing National Laboratory for Molecular Sciences(No.BNLMS-CXXM-202006)Clinical Medicine Plus X Project of Peking University,Fundamental Research Funds for the Central Universities。
文摘Herein,we report the facile conjugation between proteins and water-soluble [60]fullerene derivatives(DC_(60)) under native conditions using SpyTag as a reactive handle.Water-soluble [60] fullerene derivatives were first prepared via sequential Bingel-Hirsch reaction and "clicked" with SpyTag to give DC_(60)-SpyTag for native conjugation with proteins by the highly efficient SpyTag-SpyCatcher chemistry.The bioconjugation was confirmed by MALDI-TOF MS spectra and SDS-PAGE analysis.The TEM and UVvis spectroscopic study further revealed that the DC_(60) could alter the optical performance and induce aggregation of the target proteins.It thus provides a general and robust method for modifying proteins with C_(60) derivatives and could potentially be adapted for native conjugation between proteins and other nonbiological motifs as well.
基金support fromthe National Key R&D Program of China(grant nos.2020YFA0908100,2020AAA0105200)the National Natural Science Foundation of China(NSFC,grant nos.21991132,21925102,92056118,8200907120,8200907121)Beijing National Laboratory for Molecular Sciences(BNLMS,grant no.BNLMS-CXXM-202006).
文摘Genetically encoded covalent peptide tagging tools such as the SpyTag/SpyCatcher reactive pair,have been demonstrated versatile and useful for protein modification.Herein,we present a superpositively charged SpyCatcher bearing a theoretical net charge of+21 capable of accomplishing multiple unrelated independent tasks to enrich this toolbox and cultivate new functions.The SpyCatcher(+21)possessed stimuli-responsive reactivity toward SpyTag and could serve as a potent and general platform for the delivery of proteins,including RNaseAinto HeLa cells.Remarkably,the delivered RNase A caused substantial proliferation inhibition toward HeLa cells.In addition,the superpositively charged SpyCatcher could form coacervate with plasmid DNA for further study of gene delivery and liquid–liquid phase separation.These findings demonstrate the robustness of the SpyTag/SpyCatcher structure against surface mutation and the prospect of applying supercharging technology on diverse functional proteins to create moonlighting proteins.
基金Supported by the National Natural Science Foundation of China(NNSFC,12005077)Guangdong Basic and Applied Basic Research Foundation(2021A1515012374).
文摘In the electromagnetic channel,chaotic gravitational lensing is a peculiar phenomenon in strong gravita-tional lensing.In this study,we analyze the properties and emergence of chaotic gravitational lensing in the Manko-Novikov black hole spacetime.Aiming to better understand the underlying physics,we elaborate on the boundaries of the accessible region through analyses of the contours of the effective potentials.The latter is associated with the two roots of a quadratic equation.In particular,we explore its interplay with an ergoregion,which leads to specific features of the effective potentials,such as the emergence of a cuspy edge and the formation of a pocket,which serve as static constraints on the geodesics.Additionally,we investigate the properties of the radial and angular accelerations at the turning points in photon trajectories.The accelerations are further examined and may provide kinematic constraints on the geodesics,as argued herein.It is concluded that the onset of the chaotic lensing is significantly related to both con-straints;as a result,an arbitrary slight deviation in the incident photon is significantly amplified during evolution through an extensive period,demonstrating the complexity in the highly nonlinear deterministic gravitational system.
