Objective To establish a method for simultaneous determination of trace levels of microcystins,cylindrospermopsin,anatoxin,and nodularin in lake water based on liquid chromatography-tandem mass spectrometry(LC-MS/MS).Methods After being adjusted to alkaline conditions and mixed with six internal standards,the water samples were enriched using dual HLB and ENVI-Carb cartridges.The eluates were then evaporated under nitrogen,reconstituted,and subjected to instrumental analysis.Both water and acetonitrile containing 0.1%formic acid were used as mobile phases.An ACQUITY UPLC? BEH C18 column(150 mm×2.1 mm,1.7 μm)was selected to separate the target cyanotoxins.Multiple reaction monitoring was applied for data acquisition,and quantification was accomplished using internal standard methods.Results Within certain concentration ranges,all 14 cyanotoxins examined in the study showed good linearity,with all correlation coefficients greater than 0.998.When the water volume was 100 mL,the limits of detection and quantification for the 14 cyanotoxins were 0.1-0.9 ng/L and 0.3-2.9 ng/L,respectively,and spiked recoveries and relative standard deviations were 81.7%-132.9%and 1.2%-14.9%,respectively.In the 10 lake water samples analyzed,cylindrospermopsin,anatoxin-α,and multiple microcystins were detected.Conclusion The method developed in the study has high-throughput capacity,as well as high sensitivity,accuracy,and reliability.The method can be applied in the simultaneous detection of microcystins,cylindrospermopsin,anatoxin,and nodularin in lake water.

Objective To explore the role of nucleolin 6(NOL6)in the occurrence and development of hypertension and its mechanism of regulating ribosome biogenesis.Methods Differentially expressed genes were screened based on the GEO database(chip GSE212338),and intersection analysis was conducted in combination with genes related to ribosome generation to obtain genes related to ribosome biogenesis in hypertension.The rats were divided into control group and model group(L-NAME group).The hypertensive rat model was induced by N-nitro-L-arginine methyl ester(L-NAME),and the thickness and pathological changes of the aortic wall in each group were observed by HE staining.The expression of ribosomal RNA(rRNA)in rat aortic tissues was detected by qPCR to reflect ribosome biogenesis,and the protein expression of NOL6 was detected by Western blotting.Human umbilical vein endothelial cells(HUVECs)were cultured and grouped for treatment(control group,L-NAME group,AngⅡ group,AngⅡ+si-NC group,AngⅡ+si-NOL6 group,and AngⅡ+CX-5461 group).The generation of neocRNA in HUVEC was detected by EU.The protein and mRNA expressions of NOL6 in HUVEC were detected by Western blotting and qPCR,respectively.Western blotting was used to detect the protein expressions of endothelial nitric oxide synthase(eNOS)and p-eNOS.Results By combining the differential expression analysis of the GEO hypertension dataset GSE212338 and the ribosome biogenesis gene set,six core genes with significantly altered expression in hypertension and related to ribosome biogenesis were identified.The difference in NOL6 was the most significant.Compared with the control group,the aortic wall thickness of rats in the L-NAME group increased significantly.Ribosomal RNA expression was significantly upregulated;the protein and mRNA expressions of NOL6 were significantly upregulated,too.Compared with the control group,the generation of neoRNA in the cells of the L-NAME group increased significantly;the levels of NOL6 protein and mRNA,ribosomal RNA and neoRNA in the Ang Ⅱ group were significantly increased compared with the control group but significantly decreased compared with the Ang Ⅱ+si-NC group.Compared with the Ang Ⅱ+si-NOL6 group,the protein and mRNA expressions of NOL6 in the AngⅡ+si-NC group and the AngⅡ+CX-5461 group cells were significantly increased.Compared with the AngⅡ+si-NC group,the levels of ribosomal RNA and neoRNA in the AngⅡ+si-NOL6 group and the AngⅡ+CX-5461 group were significantly decreased;the protein expressions of eNOS and p-eNOS were significantly increased.Conclusion NOL6 is associated with abnormal ribosome biogenesis in hypertension.NOL6 can affect the expression of eNOS by regulating ribosome biogenesis,thereby regulating the occurrence and development of hypertension.

AIM:To explore the mechanism of Salvia miltiorrhiza(Danshen)-derived exosome-like nanoparti-cles(DDN)in attenuating oxidative damage in endothelial cells through the activation of the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(PKB/Akt)/endothelial nitric oxide synthase(eNOS)signaling pathway.METHODS:The DDN were characterized by transmission electron microscopy and dynamic light scattering.Fluorescence microscopy and flow cytometry were used to evaluate the uptake of DDN by human umbilical vein endothelial cells(HUVECs).The viability,migration and invasion of HUVECs were assessed using CCK8 assay,wound-healing assay and Transwell assay,respec-tively.The HUVECs were induced by angiotensin II(Ang II)for oxidative stress and intervened with DDN or LY294002(a PI3K inhibitor).The levels of reactive oxygen species were determined by flow cytometry,and intracellular nitric oxide(NO)content was measured using a biochemical assay kit.Additionally,the protein levels of NADPH oxidase 4(NOX4),NOX2,endothelial nitric oxide syntnase(eNOS),p-eNOS,Akt and p-Akt were examined by Western blot.RESULTS:(1)Transmission electron microscopy and dynamic light scattering analysis revealed that DDN had good bio-compatibility and stability.(2)According to fluorescence images and flow cytometry results,DDN were strongly taken up by HUVECs.(3)Compared with control group,DDN significantly promoted the viability,migration and invasion of HUVECs,showing a dose-dependent effect.(4)Compared with control group,DDN remarkably increased intracellular NO levels,thereby enhancing endothelial cell vasodilation via activating the PI3K/Akt/eNOS signaling pathway.(5)The PI3K/Akt/eNOS pathway played a critical role in mitigating oxidative stress and improving cellular function in response to DDN treat-ment.CONCLUSION:The DDN mediate PI3K/Akt/eNOS signaling pathway activation to significantly alleviate Ang II-induced oxidative damage in endothelial cells,suggesting a potential vascular protective effect of DDN.

AIM:To explore the mechanism of Salvia miltiorrhiza(Danshen)-derived exosome-like nanoparti-cles(DDN)in attenuating oxidative damage in endothelial cells through the activation of the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(PKB/Akt)/endothelial nitric oxide synthase(eNOS)signaling pathway.METHODS:The DDN were characterized by transmission electron microscopy and dynamic light scattering.Fluorescence microscopy and flow cytometry were used to evaluate the uptake of DDN by human umbilical vein endothelial cells(HUVECs).The viability,migration and invasion of HUVECs were assessed using CCK8 assay,wound-healing assay and Transwell assay,respec-tively.The HUVECs were induced by angiotensin II(Ang II)for oxidative stress and intervened with DDN or LY294002(a PI3K inhibitor).The levels of reactive oxygen species were determined by flow cytometry,and intracellular nitric oxide(NO)content was measured using a biochemical assay kit.Additionally,the protein levels of NADPH oxidase 4(NOX4),NOX2,endothelial nitric oxide syntnase(eNOS),p-eNOS,Akt and p-Akt were examined by Western blot.RESULTS:(1)Transmission electron microscopy and dynamic light scattering analysis revealed that DDN had good bio-compatibility and stability.(2)According to fluorescence images and flow cytometry results,DDN were strongly taken up by HUVECs.(3)Compared with control group,DDN significantly promoted the viability,migration and invasion of HUVECs,showing a dose-dependent effect.(4)Compared with control group,DDN remarkably increased intracellular NO levels,thereby enhancing endothelial cell vasodilation via activating the PI3K/Akt/eNOS signaling pathway.(5)The PI3K/Akt/eNOS pathway played a critical role in mitigating oxidative stress and improving cellular function in response to DDN treat-ment.CONCLUSION:The DDN mediate PI3K/Akt/eNOS signaling pathway activation to significantly alleviate Ang II-induced oxidative damage in endothelial cells,suggesting a potential vascular protective effect of DDN.

Objective To explore the role of nucleolin 6(NOL6)in the occurrence and development of hypertension and its mechanism of regulating ribosome biogenesis.Methods Differentially expressed genes were screened based on the GEO database(chip GSE212338),and intersection analysis was conducted in combination with genes related to ribosome generation to obtain genes related to ribosome biogenesis in hypertension.The rats were divided into control group and model group(L-NAME group).The hypertensive rat model was induced by N-nitro-L-arginine methyl ester(L-NAME),and the thickness and pathological changes of the aortic wall in each group were observed by HE staining.The expression of ribosomal RNA(rRNA)in rat aortic tissues was detected by qPCR to reflect ribosome biogenesis,and the protein expression of NOL6 was detected by Western blotting.Human umbilical vein endothelial cells(HUVECs)were cultured and grouped for treatment(control group,L-NAME group,AngⅡ group,AngⅡ+si-NC group,AngⅡ+si-NOL6 group,and AngⅡ+CX-5461 group).The generation of neocRNA in HUVEC was detected by EU.The protein and mRNA expressions of NOL6 in HUVEC were detected by Western blotting and qPCR,respectively.Western blotting was used to detect the protein expressions of endothelial nitric oxide synthase(eNOS)and p-eNOS.Results By combining the differential expression analysis of the GEO hypertension dataset GSE212338 and the ribosome biogenesis gene set,six core genes with significantly altered expression in hypertension and related to ribosome biogenesis were identified.The difference in NOL6 was the most significant.Compared with the control group,the aortic wall thickness of rats in the L-NAME group increased significantly.Ribosomal RNA expression was significantly upregulated;the protein and mRNA expressions of NOL6 were significantly upregulated,too.Compared with the control group,the generation of neoRNA in the cells of the L-NAME group increased significantly;the levels of NOL6 protein and mRNA,ribosomal RNA and neoRNA in the Ang Ⅱ group were significantly increased compared with the control group but significantly decreased compared with the Ang Ⅱ+si-NC group.Compared with the Ang Ⅱ+si-NOL6 group,the protein and mRNA expressions of NOL6 in the AngⅡ+si-NC group and the AngⅡ+CX-5461 group cells were significantly increased.Compared with the AngⅡ+si-NC group,the levels of ribosomal RNA and neoRNA in the AngⅡ+si-NOL6 group and the AngⅡ+CX-5461 group were significantly decreased;the protein expressions of eNOS and p-eNOS were significantly increased.Conclusion NOL6 is associated with abnormal ribosome biogenesis in hypertension.NOL6 can affect the expression of eNOS by regulating ribosome biogenesis,thereby regulating the occurrence and development of hypertension.

AIM:To investigate the effects of adipose-derived stem cells(ADSCs)with overexpression or si-lencing of long noncoding RNA(lncRNA)SNHG8 on the viability,migration,angiogenesis,and the expression of vasoac-tive factors in human umbilical vein endothelial cells(HUVECs).METHODS:Identification of ADSCs derived from morbidly obese patients(O-ADSCs)was conducted using flow cytometry and induction of lipogenesis and osteogenesis.The expression of lncRNA SNHG8 in healthy human ADSCs(H-ADSCs)and O-ADSCs was detected by RT-qPCR.Tran-swell method was used to establish the indirect co-culture system of ADSCs and HUVECs for 48 h,and the cells were di-vided into O-ADSCs+HUVECs group,H-ADSCs+HUVECs group,and HUVECs alone group.The mRNA and protein ex-pression levels of angiotensin Ⅱ(Ang Ⅱ),endothelin-1(ET-1)and endothelial nitric oxide synthase(eNOS)in HUVECs were detected by RT-qPCR and Western blot.The lncRNA SNHG8 overexpression and silencing lentiviruses were con-structed and used to infect O-ADSCs.The indirect co-cultured ADSCs and HUVECs were divided into O-ADSCs-OE-SNHG8+ HUVECs group,O-ADSCs-OE-NC+HUVECs group,O-ADSCs-sh-SNHG8+HUVECs group,and O-ADSCs-sh-NC+HUVECs group.After co-culture for 48 h,the viability,migration and tubule formation of HUVECs were detected by CCK-8,scratch and angiogenesis assays,respectively.The mRNA and protein expression levels of Ang Ⅱ,ET-1 and eNOS in HU-VECs were detected by RT-qPCR and Western blot,respectively.The nitrate reductase method was used to detect the con-tent of NO in HUVECs.RESULTS:(1)The cultured cells were identified as ADSCs.(2)Compared with H-ADSCs,ln-cRNA SNHG8 expression was significantly up-regulated in O-ADSCs(P<0.01).(3)Compared with H-ADSCs+HUVECs group and HUVECs group,the mRNA and protein expression levels of Ang Ⅱ and ET-1 in HUVECs in O-ADSCs+HU-VECs group were up-regulated(P<0.01).(4)Overexpression of lncRNA SNHG8 in O-ADSCs enhanced the viability,mi-gration and tube formation ability of HUVECs,up-regulated the mRNA and protein expression levels of Ang Ⅱ and ET-1,down-regulated the mRNA and protein expression levels of eNOS,and decreased the content of NO in HUVECs(P<0.05).However,silencing of lncRNA SNHG8 in O-ADSCs exerted opposite results(P<0.05).CONCLUSION:(1)The O-ADSCs can promote endothelial cell viability,migration and tubule formation through paracrine effects.(2)The O-ADSCs with overexpression of lncRNA SNHG8 promote the imbalance of diastolic and contractile factors secreted by endo-thelial cells,and induce the dysfunction of vascular endothelial cells.