Red blood cells(RBCs)are able to interact and communicate with endothelial cells(ECs).Under some pathological or even normal conditions,the adhesion of RBCs to the endothelium can be observed.Presently,the mechanisms ...Red blood cells(RBCs)are able to interact and communicate with endothelial cells(ECs).Under some pathological or even normal conditions,the adhesion of RBCs to the endothelium can be observed.Presently,the mechanisms and many aspects of the interaction between RBCs and ECs are not fully understood.In this work,we considered the interaction of single RBCs with single ECs in vitro aiming to quantitatively determine the force of this interaction using laser tweezers.Measurements were performed under different concentrations of proaggregant macromolecules and in the presence or absence of tumor necrosis factor(TNF-α)activating the ECs.We have shown that the strength of interaction depends on the concentration of fibrinogen or dextran proaggregant macromolecules in the environment.A nonlinear increase in the force of cells interaction(from 0.4 pN to 21 pN)was observed along with an increase in the fibrinogen con-centration(from 3 mg/mL to 9 mg/mL)in blood plasma,as well as with the addition of dextran macromolecules(from 10 mg/mL to 60 mg/mL).Dextran with a higher molecular mass(500 kDa)enhances the adhesion of RBCs to ECs greater compared to the dextran with a lower molecular mass(70 kDa).With the preliminary activation of ECs with TNF-α,the force of interaction increases.Also,the adhesion of echinocytes to EC compared to discocytes is significantly higher.These results may help to better understand the process of interaction between RBCs and ECs.展开更多
In the study of the mechanical properties of the erythrocytes (red blood cells-RBCs) the blood sample is commonly diluted in fluids that do not compromise the integrity of the cells. Fetal bovine serum (FBS), newborn ...In the study of the mechanical properties of the erythrocytes (red blood cells-RBCs) the blood sample is commonly diluted in fluids that do not compromise the integrity of the cells. Fetal bovine serum (FBS), newborn bovine serum (NBBS), and phosphate buffer (PBS) solution with a concentration that can provide the right osmotic pressure are fluids commonly used to dilute the blood samples in such studies. Here we have presented the effect of these fluids on the elastic properties of the RBCs that we studied using laser traps. Two laser traps are directly used to trap and deform the cell by exerting a force distributed on the entire cell. The relative changes in size of the cell are studied as a function of the applied force to investigate any effects on the mechanical deformability of RBCs when the cells are suspended in these fluids. The results have shown that the elasticity of the RBCs in the NBBS is not statistically different from the elasticity of the cells in the PBS solution;however the results for the elasticity of the cells in FBS are found to be significantly higher.展开更多
To determine the effects of microwave radiation at the molecular level as well as on the germination,growth and morphology of dry spores at the single-cell level.Dry Bacillus aryabhattai MCCC 1K02966 spores were micro...To determine the effects of microwave radiation at the molecular level as well as on the germination,growth and morphology of dry spores at the single-cell level.Dry Bacillus aryabhattai MCCC 1K02966 spores were microwave-treated at different powers and characterized using single-cell optical technology.As determined by laser tweezers Raman spectroscopy,the Ca^(2+)-dipicolinic acid content increased and nucleic acid denaturation occurred in response to microwave treatment.Livecell microscopy revealed that the germination and growth rates decreased as the microwave power increased.With respect to morphology,atomic force microscopy(AFM)demonstrated that spores became wrinkled and rough after microwave treatment.Furthermore,spores became smaller as the microwave power increased.Microwave treatment can damage DNA,and high-power microwaves can inhibit the germination of spores and reduce spore volumes.These results provide a new perspective on the responses of living single cells to microwave radiation and demonstrate the application of various new techniques for analyses of microorganisms at the single-cell level.展开更多
基金This work was supported by the Russian Foundation for Basic Research(Grant No.19-52-51015).
文摘Red blood cells(RBCs)are able to interact and communicate with endothelial cells(ECs).Under some pathological or even normal conditions,the adhesion of RBCs to the endothelium can be observed.Presently,the mechanisms and many aspects of the interaction between RBCs and ECs are not fully understood.In this work,we considered the interaction of single RBCs with single ECs in vitro aiming to quantitatively determine the force of this interaction using laser tweezers.Measurements were performed under different concentrations of proaggregant macromolecules and in the presence or absence of tumor necrosis factor(TNF-α)activating the ECs.We have shown that the strength of interaction depends on the concentration of fibrinogen or dextran proaggregant macromolecules in the environment.A nonlinear increase in the force of cells interaction(from 0.4 pN to 21 pN)was observed along with an increase in the fibrinogen con-centration(from 3 mg/mL to 9 mg/mL)in blood plasma,as well as with the addition of dextran macromolecules(from 10 mg/mL to 60 mg/mL).Dextran with a higher molecular mass(500 kDa)enhances the adhesion of RBCs to ECs greater compared to the dextran with a lower molecular mass(70 kDa).With the preliminary activation of ECs with TNF-α,the force of interaction increases.Also,the adhesion of echinocytes to EC compared to discocytes is significantly higher.These results may help to better understand the process of interaction between RBCs and ECs.
文摘In the study of the mechanical properties of the erythrocytes (red blood cells-RBCs) the blood sample is commonly diluted in fluids that do not compromise the integrity of the cells. Fetal bovine serum (FBS), newborn bovine serum (NBBS), and phosphate buffer (PBS) solution with a concentration that can provide the right osmotic pressure are fluids commonly used to dilute the blood samples in such studies. Here we have presented the effect of these fluids on the elastic properties of the RBCs that we studied using laser traps. Two laser traps are directly used to trap and deform the cell by exerting a force distributed on the entire cell. The relative changes in size of the cell are studied as a function of the applied force to investigate any effects on the mechanical deformability of RBCs when the cells are suspended in these fluids. The results have shown that the elasticity of the RBCs in the NBBS is not statistically different from the elasticity of the cells in the PBS solution;however the results for the elasticity of the cells in FBS are found to be significantly higher.
基金Lin He and Siyi Qiu received support from the National Natural Science Foundation of China(Grant No.91851210).
文摘To determine the effects of microwave radiation at the molecular level as well as on the germination,growth and morphology of dry spores at the single-cell level.Dry Bacillus aryabhattai MCCC 1K02966 spores were microwave-treated at different powers and characterized using single-cell optical technology.As determined by laser tweezers Raman spectroscopy,the Ca^(2+)-dipicolinic acid content increased and nucleic acid denaturation occurred in response to microwave treatment.Livecell microscopy revealed that the germination and growth rates decreased as the microwave power increased.With respect to morphology,atomic force microscopy(AFM)demonstrated that spores became wrinkled and rough after microwave treatment.Furthermore,spores became smaller as the microwave power increased.Microwave treatment can damage DNA,and high-power microwaves can inhibit the germination of spores and reduce spore volumes.These results provide a new perspective on the responses of living single cells to microwave radiation and demonstrate the application of various new techniques for analyses of microorganisms at the single-cell level.
