AIM: To search for the biomarker of cellular immortalization, the telomere length, telomerase activity and its subunits in cultured epithelial cells of human fetal esophagus in the process of immortalization. METHODS:...AIM: To search for the biomarker of cellular immortalization, the telomere length, telomerase activity and its subunits in cultured epithelial cells of human fetal esophagus in the process of immortalization. METHODS: The transgenic cell line of human fetal esophageal epithelium (SHEE) was established with E(6)E(7) genes of human papillomavirus (HPV) type 18 in our laboratory. Morphological phenotype of cultured SHEE cells from the 6th to 30th passages, was examined by phase contrast microscopy, the telomere length was assayed by Southern blot method, and the activity of telomerase was analyzed by telomeric repeat amplification protocol (TRAP). Expressions of subunits of telomerase, hTR and hTERT, were assessed by RT-PCR. DNA content in cell cycle was detected by flow cytometry. The cell apoptosis was examined by electron microscopy (EM) and TUNEL label. RESULTS: SHEE cells from the 6th to 10th passages showed cellular proliferation with a good differentiation. From the 12th to the 16th passages, many senescent and apoptotic cells appeared, and the telomere length sharply shortened from 23kb to 17kb without expression of hTERT and telomerase activity. At the 20th passage, SHEE cells overcame the senescence and apoptosis and restored their proliferative activity with expression of telomerase and hTERT at low levels, but the telomere length shortened continuously to the lowest of 3kb. After the 30th passage cells proliferation was restored by increment of cells at S and G2M phase in the cell cycle and telomerase activity expressed at high levels and with maintenance of telomere length. CONCLUSION: At the early stage of SHEE cells, telomeres are shortened without expression of telomerase and hTERT causing cellular senescence and cell death. From the 20th to the 30th passages, the activation of telomerase and maintenance of telomere length show a progressive process for immortalization of esophageal epithelial cells. The expression of telomerase may constitute a biomarker for detection of immortalization of cells.展开更多
Non-invasive tracing in vivo can be used to observe the migration and distnbution of grafted stem cells, and can provide experimental evidence for treatment. This study utilized adenovirus-carrying enhanced green fluo...Non-invasive tracing in vivo can be used to observe the migration and distnbution of grafted stem cells, and can provide experimental evidence for treatment. This study utilized adenovirus-carrying enhanced green fluorescent protein （AD5/F35-eGFP） and superparamagnetic iron oxide （SPIO）-Iabeled bone marrow mesenchymal stem cells （BMSCs）. BMSCs, double-labeled by AD5/F35-eGFP and SPIO, were transplanted into rats with spinal cord injury via the subarachnoid space. MRI tracing results demonstrated that BMSCs migrated to the injured spinal cord over time （T2 hypointensity signals）. This result was verified by immunofluorescence. These results indicate that MRI can be utilized to trace in vivo the SPIO-labeled BMSCs after grafting.展开更多
Aim： To investigate whether the biological process of superparamagnetic iron oxide （SPIO）-labeled human mesenchymal stem cells （hMSCs） may be monitored non-invasively by using in vivo magnetic resonance （MR） im...Aim： To investigate whether the biological process of superparamagnetic iron oxide （SPIO）-labeled human mesenchymal stem cells （hMSCs） may be monitored non-invasively by using in vivo magnetic resonance （MR） imaging with conventional 1.5-T system examinations in corpus cavernosa of rats and rabbits. Methods： The labeling efficiency and viability of SP10-labeled hMSCs were examined with Prussian blue and Tripan blue, respectively. After SPIO-labeled hMSCs were transplanted to the corpus cavernosa of rats and rabbits, serial T2-weighted MR images were taken and histological examinations were carried out over a 4-week period. Results： hMSCs loaded with SPIO compared to unlabeled cells had a similar viability. For SPIO-labeled hMSCs more than lx 105 concentration in vitro, MR images showed a decrease in signal intensity. MR signal intensity at the areas of SPIO-labeled hMSCs in the rat and rabbit corpus cavernosa decreased and was confined locally. After injection of SPIO-labeled hMSCs into the corpus cavernosum, MR imaging demonstrated that hMSCs could be seen for at least 12 weeks after injection. The presence of iron was confirmed with Prussian blue staining in histological sections. Conclusion： SP10-labeled hMSCs in corpus cavernosa of rats and rabbits can be evaluated non-invasively by molecular MR imaging. Our findings suggest that MR imaging has the ability to test the long-term therapeutic potential of hMSCs in animals in the setting of erectile dysfunction.展开更多
Neural stem cells were labeled with superparamagnetic iron oxide （SPIO） and tracked by MRI in vitro and in vivo after implantation, Rat neural stem cells were labeled with SPIO combined with PLL by the means of rece...Neural stem cells were labeled with superparamagnetic iron oxide （SPIO） and tracked by MRI in vitro and in vivo after implantation, Rat neural stem cells were labeled with SPIO combined with PLL by the means of receptor-mediated endocytosis. Prussian blue staining and electron microscopy were conducted to identify the iron particles in these neural stem cells. SPIO-labeled cells were tracked by 4.7T MRI in vivo and in vitro after implantation, The subjects were divided into 5 groups, including 5× 10^5 labeled cells cultured for one day after labeling, 5 × 10^5 same phase unlabeled cells, cell culture medium with 25μg Fe/mL SPIO, cell culture medium without SPIO and distilled water. MR/scanning sequences included TIWI, T2WI and T2＊WI. R2 and R2＊ of labeled cells were calculated. The results showed： （1） Neural stem cells could be labeled with SPIO and labeling efficiency was 100%. Prussian blue staining showed numerous blue-stained iron particles in the cytoplasm; （2） The average percentage change of signal intensity of labeled cells on TIWI in 4.7T MRI was 24.06%, T2WI 50.66% and T2＊WI 53.70% respectively; （3） T2 of labeled cells and unlabeled cells in 4.7T MRI was 516 ms and 77 ms respectively, R2 was 1.94 s^-1 and 12.98 s^-1 respectively, and T2＊ was 109 ms and 22.9 ms, R2＊ was 9.17 s^-1 and 43.67 s^-1 respectively; （4） Remarkable low signal area on T2WI and T2＊WI could exist for nearly 7 weeks and then disappeared gradually in the left brain transplanted with labeled cells, however no signal change in the right brain implanted with unlabeled cells. It was concluded that neural stem cells could be labeled effectively with SPIO. R2 and R2＊ of labeled cells were increased obviously. MRI can be used to track labeled cells in vitro and in vivo.展开更多
Mesenchymal stem cells(MSCs)transplantation is a promising approach for pulmonary fibrosis(PF),however it is impeded by several persistent challenges,including the lack of long-term tracking,low retention,and poor sur...Mesenchymal stem cells(MSCs)transplantation is a promising approach for pulmonary fibrosis(PF),however it is impeded by several persistent challenges,including the lack of long-term tracking,low retention,and poor survival of MSCs,as well as the low labeling efficiency of nanoprobes.Herein,a cobalt protoporphyrin IX(CoPP)aggregation-induced strategy is applied to develop a multifunctional nano-self-assembly(ASCP)by combining gold nanoparticle(AuNPs),superparamagnetic iron oxide nanoparticles(SPIONs),and CoPP through a facile solvent evaporation-driven approach.Since no additional carrier materials are employed during the synthesis,high loading efficiency of active ingredients and excellent biocompatibility are achieved.Additionally,facile modification of the ASCPs with bicyclo[6.1.0]nonyne(BCN)groups(named as ASCP-BCN)enables them to effectively label MSCs through bioorthogonal chemistry.The obtained ASCP-BCN could not only help to track MSCs with AuNP-based computed tomography(CT)imaging,but also achieve an SPIONs-assisted magnetic field based improvement in the MSCs retention in lungs as well as promoted the survival of MSCs via the sustained release of CoPP.The in vivo results demonstrated that the labeled MSCs improved the lung functions and alle-viated the fibrosis symptoms in a bleomycin–induced PF mouse model.Collectively,a novel ASCP-BCN multi-functional nanoagent was developed to bioorthogonally-label MSCs with a high efficiency,presenting a promising potential in the high-efficient MSC therapy for PF.展开更多
As a type of new carbon-based nanomaterials,carbon dots(CDs)possess exceptional optical properties,making them highly desirable for use in fluorescent sensors.However,the CDs with deep-red(DR)or near-infrared(NIR)emis...As a type of new carbon-based nanomaterials,carbon dots(CDs)possess exceptional optical properties,making them highly desirable for use in fluorescent sensors.However,the CDs with deep-red(DR)or near-infrared(NIR)emission have rarely been reported.In this work,we prepared deep-red emissive fluorine-doped carbon quantum dots(F-CDs)by introducing a precursor simultaneously containing fluorine and amidogen.The synergistic effect of nitrogen doping and D-π-A pattern production contributed to the maximum emission of F-CDs at 636 nm with an absolute quantum yield of 36.00%±0.68%.Moreover,we designed an F-CDs-based fluorescence assay to determine the content of hypochlorite(ClO^(-)),with a limit of detection(LOD)as low as 15.4 nmol/L,indicating the high sensitivity of F-CDs to ClO^(-).In real samples,the F-CDs-based fluorescent sensor exhibited excellent sensitivity and selectivity in the detection of ClO^(-),with an error below 2%,suggesting their great potential in daily life.In cancer cell imaging,the F-CDs not only demonstrated high sensitivity to ClO^(-)but also exhibited excellent mitochondria targeting,as evidenced by the high Pearson's correlation coefficient(PCC)of 0.93 in colocalization analysis.The work presented here suggests the great potential of replacing commercial dyes with F-CDs for highly specific mitochondria labeling and cell imaging.展开更多
Context:Bioinspired Artificial Intelligence(Bio-AI)has emerged as a transformative tool in biomedical research,addressing challenges in cell labeling essential for understanding cellular behavior and interactions.Trad...Context:Bioinspired Artificial Intelligence(Bio-AI)has emerged as a transformative tool in biomedical research,addressing challenges in cell labeling essential for understanding cellular behavior and interactions.Traditional cell labeling methods often struggle with accuracy,scalability,and adaptability in complex datasets.Objective:This paper theoretically explores the integration of Bio-AI models into cell labeling process.It aims to assess how these models C encompassing neural networks,swarm intelligence,evolutionary algorithms,and self-organizing maps C can enhance cell identification and classification.Method:The paper examines various Bio-AI models that mimic biological processes such as neural functioning,swarm behavior,and evolutionary dynamics.It also evaluates the application of multimodal AI systems that combine imaging data with molecular and genetic information.In addition,the potential of dynamic cell labeling,inspired by neural plasticity,is discussed.Result:The integration of Bio-AI models has demonstrated significant improvements in accuracy,adaptability,and scalability for cell labeling.Automated labeling systems minimize human error and enhance reproducibility.Recent advancements in multimodal AI systems have shown promise in combining imaging with genetic and molecular data,providing more comprehensive insights into cellular behavior.Dynamic labeling models inspired by neural plasticity offer enhanced tracking of cellular transitions over time.Conclusion:Bio-AI holds transformative potential in biomedical research via enabling real-time,dynamic labeling,essential for tracking cellular changes over time in processes like cancer progression,stem cell differentiation,and immune response.The continued evolution of these AI-driven approaches is expected to accelerate breakthroughs in understanding diseases,tissue engineering,and regenerative medicine.展开更多
基金the National Natural Science Foundation of Chines,No.39830380
文摘AIM: To search for the biomarker of cellular immortalization, the telomere length, telomerase activity and its subunits in cultured epithelial cells of human fetal esophagus in the process of immortalization. METHODS: The transgenic cell line of human fetal esophageal epithelium (SHEE) was established with E(6)E(7) genes of human papillomavirus (HPV) type 18 in our laboratory. Morphological phenotype of cultured SHEE cells from the 6th to 30th passages, was examined by phase contrast microscopy, the telomere length was assayed by Southern blot method, and the activity of telomerase was analyzed by telomeric repeat amplification protocol (TRAP). Expressions of subunits of telomerase, hTR and hTERT, were assessed by RT-PCR. DNA content in cell cycle was detected by flow cytometry. The cell apoptosis was examined by electron microscopy (EM) and TUNEL label. RESULTS: SHEE cells from the 6th to 10th passages showed cellular proliferation with a good differentiation. From the 12th to the 16th passages, many senescent and apoptotic cells appeared, and the telomere length sharply shortened from 23kb to 17kb without expression of hTERT and telomerase activity. At the 20th passage, SHEE cells overcame the senescence and apoptosis and restored their proliferative activity with expression of telomerase and hTERT at low levels, but the telomere length shortened continuously to the lowest of 3kb. After the 30th passage cells proliferation was restored by increment of cells at S and G2M phase in the cell cycle and telomerase activity expressed at high levels and with maintenance of telomere length. CONCLUSION: At the early stage of SHEE cells, telomeres are shortened without expression of telomerase and hTERT causing cellular senescence and cell death. From the 20th to the 30th passages, the activation of telomerase and maintenance of telomere length show a progressive process for immortalization of esophageal epithelial cells. The expression of telomerase may constitute a biomarker for detection of immortalization of cells.
基金the National Natural Science Foundation of China,No.81000530, 30973093the Creative Talent Project of Henan Province Health Department, No.2010-4106
文摘Non-invasive tracing in vivo can be used to observe the migration and distnbution of grafted stem cells, and can provide experimental evidence for treatment. This study utilized adenovirus-carrying enhanced green fluorescent protein （AD5/F35-eGFP） and superparamagnetic iron oxide （SPIO）-Iabeled bone marrow mesenchymal stem cells （BMSCs）. BMSCs, double-labeled by AD5/F35-eGFP and SPIO, were transplanted into rats with spinal cord injury via the subarachnoid space. MRI tracing results demonstrated that BMSCs migrated to the injured spinal cord over time （T2 hypointensity signals）. This result was verified by immunofluorescence. These results indicate that MRI can be utilized to trace in vivo the SPIO-labeled BMSCs after grafting.
文摘Aim： To investigate whether the biological process of superparamagnetic iron oxide （SPIO）-labeled human mesenchymal stem cells （hMSCs） may be monitored non-invasively by using in vivo magnetic resonance （MR） imaging with conventional 1.5-T system examinations in corpus cavernosa of rats and rabbits. Methods： The labeling efficiency and viability of SP10-labeled hMSCs were examined with Prussian blue and Tripan blue, respectively. After SPIO-labeled hMSCs were transplanted to the corpus cavernosa of rats and rabbits, serial T2-weighted MR images were taken and histological examinations were carried out over a 4-week period. Results： hMSCs loaded with SPIO compared to unlabeled cells had a similar viability. For SPIO-labeled hMSCs more than lx 105 concentration in vitro, MR images showed a decrease in signal intensity. MR signal intensity at the areas of SPIO-labeled hMSCs in the rat and rabbit corpus cavernosa decreased and was confined locally. After injection of SPIO-labeled hMSCs into the corpus cavernosum, MR imaging demonstrated that hMSCs could be seen for at least 12 weeks after injection. The presence of iron was confirmed with Prussian blue staining in histological sections. Conclusion： SP10-labeled hMSCs in corpus cavernosa of rats and rabbits can be evaluated non-invasively by molecular MR imaging. Our findings suggest that MR imaging has the ability to test the long-term therapeutic potential of hMSCs in animals in the setting of erectile dysfunction.
基金This project was supported by a grant from National Natural Sciences Youth Foundation of China (30300093).
文摘Neural stem cells were labeled with superparamagnetic iron oxide （SPIO） and tracked by MRI in vitro and in vivo after implantation, Rat neural stem cells were labeled with SPIO combined with PLL by the means of receptor-mediated endocytosis. Prussian blue staining and electron microscopy were conducted to identify the iron particles in these neural stem cells. SPIO-labeled cells were tracked by 4.7T MRI in vivo and in vitro after implantation, The subjects were divided into 5 groups, including 5× 10^5 labeled cells cultured for one day after labeling, 5 × 10^5 same phase unlabeled cells, cell culture medium with 25μg Fe/mL SPIO, cell culture medium without SPIO and distilled water. MR/scanning sequences included TIWI, T2WI and T2＊WI. R2 and R2＊ of labeled cells were calculated. The results showed： （1） Neural stem cells could be labeled with SPIO and labeling efficiency was 100%. Prussian blue staining showed numerous blue-stained iron particles in the cytoplasm; （2） The average percentage change of signal intensity of labeled cells on TIWI in 4.7T MRI was 24.06%, T2WI 50.66% and T2＊WI 53.70% respectively; （3） T2 of labeled cells and unlabeled cells in 4.7T MRI was 516 ms and 77 ms respectively, R2 was 1.94 s^-1 and 12.98 s^-1 respectively, and T2＊ was 109 ms and 22.9 ms, R2＊ was 9.17 s^-1 and 43.67 s^-1 respectively; （4） Remarkable low signal area on T2WI and T2＊WI could exist for nearly 7 weeks and then disappeared gradually in the left brain transplanted with labeled cells, however no signal change in the right brain implanted with unlabeled cells. It was concluded that neural stem cells could be labeled effectively with SPIO. R2 and R2＊ of labeled cells were increased obviously. MRI can be used to track labeled cells in vitro and in vivo.
基金National Natural Science Foundation of China(Grant Nos.52072392,32030061,82171951)Key Program for Basic Research of Shanghai(Grant Nos.20JC1411900,21JC1406000)+1 种基金Shanghai Rising-Star Program(Grant No.19QA1410300)Youth Innovation Promotion Association CAS(Grant No.2020255).
文摘Mesenchymal stem cells(MSCs)transplantation is a promising approach for pulmonary fibrosis(PF),however it is impeded by several persistent challenges,including the lack of long-term tracking,low retention,and poor survival of MSCs,as well as the low labeling efficiency of nanoprobes.Herein,a cobalt protoporphyrin IX(CoPP)aggregation-induced strategy is applied to develop a multifunctional nano-self-assembly(ASCP)by combining gold nanoparticle(AuNPs),superparamagnetic iron oxide nanoparticles(SPIONs),and CoPP through a facile solvent evaporation-driven approach.Since no additional carrier materials are employed during the synthesis,high loading efficiency of active ingredients and excellent biocompatibility are achieved.Additionally,facile modification of the ASCPs with bicyclo[6.1.0]nonyne(BCN)groups(named as ASCP-BCN)enables them to effectively label MSCs through bioorthogonal chemistry.The obtained ASCP-BCN could not only help to track MSCs with AuNP-based computed tomography(CT)imaging,but also achieve an SPIONs-assisted magnetic field based improvement in the MSCs retention in lungs as well as promoted the survival of MSCs via the sustained release of CoPP.The in vivo results demonstrated that the labeled MSCs improved the lung functions and alle-viated the fibrosis symptoms in a bleomycin–induced PF mouse model.Collectively,a novel ASCP-BCN multi-functional nanoagent was developed to bioorthogonally-label MSCs with a high efficiency,presenting a promising potential in the high-efficient MSC therapy for PF.
基金supported by the National Natural Science Foundation of China(Nos.82222035 and 81602489)the Guangdong Basic and Applied Basic Research Foundation(Nos.2021A1515111036 and 2022A1515110308)+1 种基金the Medical Scientific Research Foundation of Guangdong Province of China(No.A2023274)the Basic Research Program of Shenzhen Innovation Council(No.JCYJ20210324105609024)。
文摘As a type of new carbon-based nanomaterials,carbon dots(CDs)possess exceptional optical properties,making them highly desirable for use in fluorescent sensors.However,the CDs with deep-red(DR)or near-infrared(NIR)emission have rarely been reported.In this work,we prepared deep-red emissive fluorine-doped carbon quantum dots(F-CDs)by introducing a precursor simultaneously containing fluorine and amidogen.The synergistic effect of nitrogen doping and D-π-A pattern production contributed to the maximum emission of F-CDs at 636 nm with an absolute quantum yield of 36.00%±0.68%.Moreover,we designed an F-CDs-based fluorescence assay to determine the content of hypochlorite(ClO^(-)),with a limit of detection(LOD)as low as 15.4 nmol/L,indicating the high sensitivity of F-CDs to ClO^(-).In real samples,the F-CDs-based fluorescent sensor exhibited excellent sensitivity and selectivity in the detection of ClO^(-),with an error below 2%,suggesting their great potential in daily life.In cancer cell imaging,the F-CDs not only demonstrated high sensitivity to ClO^(-)but also exhibited excellent mitochondria targeting,as evidenced by the high Pearson's correlation coefficient(PCC)of 0.93 in colocalization analysis.The work presented here suggests the great potential of replacing commercial dyes with F-CDs for highly specific mitochondria labeling and cell imaging.
文摘Context:Bioinspired Artificial Intelligence(Bio-AI)has emerged as a transformative tool in biomedical research,addressing challenges in cell labeling essential for understanding cellular behavior and interactions.Traditional cell labeling methods often struggle with accuracy,scalability,and adaptability in complex datasets.Objective:This paper theoretically explores the integration of Bio-AI models into cell labeling process.It aims to assess how these models C encompassing neural networks,swarm intelligence,evolutionary algorithms,and self-organizing maps C can enhance cell identification and classification.Method:The paper examines various Bio-AI models that mimic biological processes such as neural functioning,swarm behavior,and evolutionary dynamics.It also evaluates the application of multimodal AI systems that combine imaging data with molecular and genetic information.In addition,the potential of dynamic cell labeling,inspired by neural plasticity,is discussed.Result:The integration of Bio-AI models has demonstrated significant improvements in accuracy,adaptability,and scalability for cell labeling.Automated labeling systems minimize human error and enhance reproducibility.Recent advancements in multimodal AI systems have shown promise in combining imaging with genetic and molecular data,providing more comprehensive insights into cellular behavior.Dynamic labeling models inspired by neural plasticity offer enhanced tracking of cellular transitions over time.Conclusion:Bio-AI holds transformative potential in biomedical research via enabling real-time,dynamic labeling,essential for tracking cellular changes over time in processes like cancer progression,stem cell differentiation,and immune response.The continued evolution of these AI-driven approaches is expected to accelerate breakthroughs in understanding diseases,tissue engineering,and regenerative medicine.
