BACKGROUND:Angiogenesis is the main treatment target of cardiovascular diseases.Bone morphogenetic protein 2 can modulate angiogenesis,but the regulatory effect of endothelial cell-specific bone morphogenetic protein 2 on angiogenesis is unclear. OBJECTIVE:To investigate the effect of endothelial-specific bone morphogenetic protein 2 on angiogenesis. METHODS:(1)Bioinformatics analysis:Cellular expression specificity and abundance of bone morphogenetic protein 2 were meta-analyzed by the PanglaoDB single-cell transcriptome database.The endothelial cell transcriptome sequencing dataset of the mouse hindlimb model and endocardial transcriptome dataset of mice overexpressing bone morphogenetic protein 2 were reanalyzed to evaluate the effect of endothelial cell bone morphogenetic protein 2 on the angiogenesis pathway.(2)Validation in vivo:After establishing the mouse hindlimb model,we compared the blood perfusion between the affected and sham limb at 7,14,and 21 days.The expression of the colocation of bone morphogenetic protein 2 and CD31 was explored by immunofluorescence and immunohistochemical staining.(3)Validation in vitro:The cultured human umbilical vein endothelial cells in vitro were divided into a control group,a hypoxia group,and a bone morphogenetic protein 2 inhibitor Noggin intervention group.After being cultured for 24 hours,the angiogenesis of endothelial cells in each group was observed. RESULTS AND CONCLUSION:(1)Endothelial cells are an important cell subgroup expressing bone morphogenetic protein 2.Both in the mouse hindlimb ischemia model and endocardial cells overexpressing bone morphogenetic protein 2,bone morphogenetic protein 2 was significantly up-regulated,and the angiogenesis pathway was significantly activated.(2)In the mouse hindlimb model,bone morphogenetic protein 2-positive blood vessels around neoangiogenesis increased significantly at 7 days of ischemia(P<0.05),and decreased significantly after 2 weeks of ischemia(P<0.001).(3)In umbilical vein endothelial cells cultured in vitro,after hypoxic intervention,the migration and sprouting of endothelial cells increased significantly,and the expression of angiogenesis factors vascular endothelial growth factor and platelet-derived growth factor was significantly increased.Noggin significantly reduced hypoxia-induced endothelial cell angiogenesis(P<0.001)and down-regulated the expression of vascular endothelial growth factor and platelet-derived growth factor(P<0.01).(4)These findings verify that endothelial cell-specific bone morphogenetic protein 2 can regulate angiogenesis,and targeting endothelial cell bone morphogenetic protein 2 is a promising way to improve angiogenesis.

BACKGROUND:Polyamines play a crucial role in tissue calcification.Spermidine/spermine N1-acetyltransferase 1(SAT1),as a key rate-limiting enzyme regulating intracellular polyamine metabolism,has been associated with various pathological processes.However,its role in vascular calcification remains unclear.OBJECTIVE:To investigate the role of SAT1 in rat vascular smooth muscle cell calcification.METHODS:(1)Bioinformatics analysis:Differential expression of SAT1 in human carotid atherosclerotic plaques and their surrounding healthy carotid artery tissues were using GEO datasets.PanglaoDB database was used to analyze SAT1 expression abundance and localization across different cell types through single-cell sequencing.(2)Rat vascular smooth muscle cells were divided into three groups:a control group cultured in DMEM medium,a calcification group induced by DMEM medium containing 10 mmol/L β-glycerophosphate sodium and 3 mmol/L calcium chloride,and the 50,100 μmol/L diacetylaminotriazamidine groups treated with the SAT1 inhibitor,diacetylaminotriazamidine,in addition to the calcification medium.After 7-10 days of culture,alizarin red S staining was performed,and cellular calcium content and alkaline phosphatase activity were assessed.Western blot was used to detect the protein expression of Runt-related transcription factor 2,bone morphogenetic protein 2,alpha-smooth muscle actin,and SAT1.Immunofluorescence staining was conducted to examine the expression of Runt-related transcription factor 2 and SAT1.RESULTS AND CONCLUSION:(1)Bioinformatics analysis revealed significantly upregulated expression of SAT1 and Runt-related transcription factor 2(P<0.05)in carotid atherosclerotic plaques compared with healthy carotid tissues(P<0.05).Single-cell sequencing database analysis confirmed SAT1 expression in vascular smooth muscle cells.(2)Compared with the control group,the calcification group showed significantly increased Runt-related transcription factor 2,bone morphogenetic protein 2,SAT1,calcium content,and alkaline phosphatase activity,while alpha-smooth muscle actin expression was significantly decreased(all P<0.05).Compared with the calcification group,the 50 and 100 μmol/L diacetylaminotriazamidine groups showed significantly decreased Runt-related transcription factor 2,bone morphogenetic protein 2,calcium content,and alkaline phosphatase activity,while alpha-smooth muscle actin expression was significantly increased(all P<0.05).(3)Immunofluorescence experiments demonstrated that compared with the calcification group,the expression intensity of Runt-related transcription factor 2 was significantly reduced in the 50 and 100 μmol/L diacetylaminotriazamidine groups.Overall,SAT1 may promote vascular smooth muscle cell calcification by upregulating Runt-related transcription factor 2 expression.

BACKGROUND:Polyamines play a crucial role in tissue calcification.Spermidine/spermine N1-acetyltransferase 1(SAT1),as a key rate-limiting enzyme regulating intracellular polyamine metabolism,has been associated with various pathological processes.However,its role in vascular calcification remains unclear.OBJECTIVE:To investigate the role of SAT1 in rat vascular smooth muscle cell calcification.METHODS:(1)Bioinformatics analysis:Differential expression of SAT1 in human carotid atherosclerotic plaques and their surrounding healthy carotid artery tissues were using GEO datasets.PanglaoDB database was used to analyze SAT1 expression abundance and localization across different cell types through single-cell sequencing.(2)Rat vascular smooth muscle cells were divided into three groups:a control group cultured in DMEM medium,a calcification group induced by DMEM medium containing 10 mmol/L β-glycerophosphate sodium and 3 mmol/L calcium chloride,and the 50,100 μmol/L diacetylaminotriazamidine groups treated with the SAT1 inhibitor,diacetylaminotriazamidine,in addition to the calcification medium.After 7-10 days of culture,alizarin red S staining was performed,and cellular calcium content and alkaline phosphatase activity were assessed.Western blot was used to detect the protein expression of Runt-related transcription factor 2,bone morphogenetic protein 2,alpha-smooth muscle actin,and SAT1.Immunofluorescence staining was conducted to examine the expression of Runt-related transcription factor 2 and SAT1.RESULTS AND CONCLUSION:(1)Bioinformatics analysis revealed significantly upregulated expression of SAT1 and Runt-related transcription factor 2(P<0.05)in carotid atherosclerotic plaques compared with healthy carotid tissues(P<0.05).Single-cell sequencing database analysis confirmed SAT1 expression in vascular smooth muscle cells.(2)Compared with the control group,the calcification group showed significantly increased Runt-related transcription factor 2,bone morphogenetic protein 2,SAT1,calcium content,and alkaline phosphatase activity,while alpha-smooth muscle actin expression was significantly decreased(all P<0.05).Compared with the calcification group,the 50 and 100 μmol/L diacetylaminotriazamidine groups showed significantly decreased Runt-related transcription factor 2,bone morphogenetic protein 2,calcium content,and alkaline phosphatase activity,while alpha-smooth muscle actin expression was significantly increased(all P<0.05).(3)Immunofluorescence experiments demonstrated that compared with the calcification group,the expression intensity of Runt-related transcription factor 2 was significantly reduced in the 50 and 100 μmol/L diacetylaminotriazamidine groups.Overall,SAT1 may promote vascular smooth muscle cell calcification by upregulating Runt-related transcription factor 2 expression.