Objective: To investigate the role and related mechanism of ubiquitin-like protein FAT10 in the angiotensin Ⅱ (AngⅡ)-induced endothelial cell inflammatory responses. Methods: The Western blot was used to detect the protein expression of FAT10 in 16-weeks old WKY rat carotid artery, thoracic aorta artery, renal artery and vascular smooth muscle cells (VSMC), human umbilical vein endothelial cells (HUVEC) and human breast cancer cells (MDA-MB-231). The optimal concentration and stimulation time of AngⅡ on inducing the highest FAT10 in HUVEC were determined. The following plasmids were constructed: control plasmid, overexpression FAT10 plasmid (Flag-FAT10), invalid interference plasmid, and interference FAT10 plasmid (sh-FAT10). These plasmids were then transfected into HUVEC cells and divided into following groups: control group, Flag-FAT10 group, invalid interference group, and sh-FAT10 group. After culturing with 100 nmol/L AngⅡ for 36 h, the control group and the Flag-FAT10 group were treated with reactive oxygen species scavenger N-acetyl-L-cysteine ​​(NAC), the protein expression levels of the inflammatory factor monocyte chemotactic protein-1 (MCP-1) and tumor necrosis factor-α (TNF-α) were measured. Laser confocal microscopy was used to detect the generation levels of reactive oxygen species in the cells of vrious groups. Results: FAT10 was expressed in carotid artery, thoracic aorta, and renal artery of normal blood pressure rats and expressed in HUVEC, VSMC, MDA-MB-231. The expression level of FAT10 gradually increased in proportion to the increase of the time and concentration of AngⅡ stimulation in HUVEC, and the expression level of FAT10 was the highest when the HUVEC was treated with 100 nmol/L AngⅡ for 36 h (P<0.01). The protein expression level of MCP-1 (P<0.001) and TNF-α (P<0.01) was higher in AngⅡ treated HUVEC with FAT10 overexpression, while the expression level of MCP-1 and TNF-α protein was lower in AngⅡ treated HUVEC with FAT10 knockdown (all P<0.01). The level of intracellular reactive oxygen species (ROS) production was significantly increased with FAT10 overexpression (P<0.001), and the level of ROS was decreased when the expression of FAT10 was interfered (P<0.05). The increased level of MCP-1 and TNF-α proteins in FAT10 overexpressed HUVEC was reversed by NAC (all P<0.05). Conclusion: FAT10 promotes the release of inflammatory factors induced by AngⅡ in endothelial cells by increasing the level of intracellular ROS production.
Humans ; Rats ; Animals ; Reactive Oxygen Species/pharmacology* ; Cells, Cultured ; Angiotensin II/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Rats, Inbred WKY ; Human Umbilical Vein Endothelial Cells ; Inflammation ; Ubiquitins/pharmacology*

Objective: To investigate the role and related mechanism of ubiquitin-like protein FAT10 in the angiotensin Ⅱ (AngⅡ)-induced endothelial cell inflammatory responses. Methods: The Western blot was used to detect the protein expression of FAT10 in 16-weeks old WKY rat carotid artery, thoracic aorta artery, renal artery and vascular smooth muscle cells (VSMC), human umbilical vein endothelial cells (HUVEC) and human breast cancer cells (MDA-MB-231). The optimal concentration and stimulation time of AngⅡ on inducing the highest FAT10 in HUVEC were determined. The following plasmids were constructed: control plasmid, overexpression FAT10 plasmid (Flag-FAT10), invalid interference plasmid, and interference FAT10 plasmid (sh-FAT10). These plasmids were then transfected into HUVEC cells and divided into following groups: control group, Flag-FAT10 group, invalid interference group, and sh-FAT10 group. After culturing with 100 nmol/L AngⅡ for 36 h, the control group and the Flag-FAT10 group were treated with reactive oxygen species scavenger N-acetyl-L-cysteine ​​(NAC), the protein expression levels of the inflammatory factor monocyte chemotactic protein-1 (MCP-1) and tumor necrosis factor-α (TNF-α) were measured. Laser confocal microscopy was used to detect the generation levels of reactive oxygen species in the cells of vrious groups. Results: FAT10 was expressed in carotid artery, thoracic aorta, and renal artery of normal blood pressure rats and expressed in HUVEC, VSMC, MDA-MB-231. The expression level of FAT10 gradually increased in proportion to the increase of the time and concentration of AngⅡ stimulation in HUVEC, and the expression level of FAT10 was the highest when the HUVEC was treated with 100 nmol/L AngⅡ for 36 h (P<0.01). The protein expression level of MCP-1 (P<0.001) and TNF-α (P<0.01) was higher in AngⅡ treated HUVEC with FAT10 overexpression, while the expression level of MCP-1 and TNF-α protein was lower in AngⅡ treated HUVEC with FAT10 knockdown (all P<0.01). The level of intracellular reactive oxygen species (ROS) production was significantly increased with FAT10 overexpression (P<0.001), and the level of ROS was decreased when the expression of FAT10 was interfered (P<0.05). The increased level of MCP-1 and TNF-α proteins in FAT10 overexpressed HUVEC was reversed by NAC (all P<0.05). Conclusion: FAT10 promotes the release of inflammatory factors induced by AngⅡ in endothelial cells by increasing the level of intracellular ROS production.
Humans ; Rats ; Animals ; Reactive Oxygen Species/pharmacology* ; Cells, Cultured ; Angiotensin II/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Rats, Inbred WKY ; Human Umbilical Vein Endothelial Cells ; Inflammation ; Ubiquitins/pharmacology*

OBJECTIVETo explore the scavenging action of tenuigenin (TEN) on intracerebral amyloid β protein (Aβ) aggregation and the abnormal phosphorylated tau protein and its mechanism in Alzheimer's disease (AD) rats' brain.

METHODSAβ1-40 was injected into the right CA1 region hippocampus to establish the AD model. Successfully modeled rats were divided into the model group, the low, middle, high TEN group. Rats were administered with TEN (18.5, 37.0, 74.0 mg/kg) by gastrogavage. Besides, a sham-operation group was set up. Expression levels of Aβ1-40 and Tau p-Ser262 were detected by immunohistochemistry. Expression levels of ubiquitin (Ub) and Ub-protein ligase E3 were measured by Western blotting.The content of 26S proteasome was detected by ELISA.

RESULTSImmunohistochemical results showed that the number of Aβ and Tau p-Ser262 positively reacted neurons significantly increased in model group, when compared with the sham-operation group (P < 0.01). Results of Western blot showed expression levels of ubiquitinated protein were up-regulated and those of Ub-protein ligase E3 were down-regulated in the model group (P < 0.01). ELISA results showed that the content of 26S proteasome significantly decreased in AD rats' brain (P < 0.01). Compared with the model group, expression levels of Aβ1-40, Tau p-Ser262, and Ub significantly decreased; expression levels of Ub-protein ligase E3 apparently increased; the content of 26S proteasome significantly increased in each TEN treatment group (P < 0.05, P < 0.01). Best effect was shown in 37.0 mg/kg and 74.0 mg/kg TEN groups.

CONCLUSIONSUb proteasome pathway (UPP) participated in the occurrence of AD. TEN could obviously reduce intracere- bral Aβ1-40 accumulation and abnormal tau phosphorylation.

Alzheimer Disease ; metabolism ; Amyloid beta-Peptides ; Animals ; Drugs, Chinese Herbal ; pharmacology ; Hippocampus ; metabolism ; Neurons ; metabolism ; Phosphorylation ; Proteasome Endopeptidase Complex ; metabolism ; Rats ; Ubiquitin-Protein Ligases ; metabolism ; Ubiquitins

Effects of Rabdocoetsin B (Rabd-B), a diterpenoid extracted from Isodon coetsa, on t(8;21) leukemic cells was tested by CCK-8 assay and Flow cytometry. The A549 cells stably expressing pGC-E1-ZU1-GFP were treated with Rabd-B for 4 h, and the accumulation of GFP was detected by fluorescence microscope. Using Western blotting, we investigated the expression of Casp-3, PARP, S6', which is a subunit of the 19S regulatory complex of the 26S proteasome, and cellular ubiqutinated proteins. We found that Rabd-B induced growth inhibition and apoptosis of Kasumi-1 cells in a dose-dependent manner. In Kasumi-1 cells treated with 2.5 micromol/L Rabd-B for 24 h, pro-caspase-3 was processed into its active form. The substrate of Casp-3, poly ADP-ribose polymerase (PARP), was cleaved with generation of an 85 kD fragment. The increased GFP fluorescence intensity, cleavage of S6' and the accumulation of ubiquitinated proteins were found in Kasumi-1 cells treated with Rabd-B. These results suggested that Rabd-B is a potential proteasome inhibitor which induces programmed cell death of t(8;21) cells. Further study might provide evidence for employing Rabd-B in treating human t(8;21) leukemia.
Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cell Line, Tumor ; Diterpenes ; isolation & purification ; pharmacology ; Humans ; Isodon ; chemistry ; Leukemia, Myeloid, Acute ; pathology ; Proteasome Inhibitors ; Translocation, Genetic ; Ubiquitins ; metabolism