1.RHPN2 is highly expressed in osteosarcoma cells to promote cell proliferation and migration and inhibit apoptosis.
Zhi Yu LIU ; Feng Zhu FANG ; Jing LI ; Guang Yue ZHAO ; Quan Jin ZANG ; Feng ZHANG ; Jun DIE
Journal of Southern Medical University 2022;42(9):1367-1373
		                        		
		                        			OBJECTIVE:
		                        			To screen for aberrantly expressed genes in osteosarcoma cells and investigate the role of RHPN2 in regulating the proliferation, apoptosis, migration and tumorigenic abilities of osteosarcoma cells.
		                        		
		                        			METHODS:
		                        			We used GEO2R to analyze the differential gene expression profile between osteosarcoma cells and normal cells in the GSE70414 dataset. RTqPCR and Western blotting were performed to detect RHPN2 expression in osteosarcoma cell lines MG-63, 143B and SAOS2. Two RHPN2-shRNA and a control NC-shRNA were designed to silence the expression of RHPN2 in 143B cells, and CCK8 assay, colony-forming assay, annexin V-FITC/PI staining and scratch assays were carried out to examine the changes in proliferation, apoptosis and migration of the cells. We also established nude mouse models bearing osteosarcoma xenografts derived 143B cells and RHPN2-shRNA-transfected 143B cells, and assessed the effect of RHPN2 silencing on osteosarcoma cell tumorigenesis using HE staining. Kaplan-Meier survival curves were used to analyze the correlation between RHPN2 expression and survival outcomes of patients with osteosarcoma.
		                        		
		                        			RESULTS:
		                        			RHPN2 expression was significantly upregulated in osteosarcoma cell lines MG-63, 143B and SAOS2 (P < 0.01). Silencing of RHPN2 significantly inhibited the proliferation and migration of 143B cells in vitro, promoted cell apoptosis (P < 0.01), and suppressed tumorigenic capacity of the cells in nude mice. A high expression of RHPN2 was significantly correlated with a poor prognosis of patients with osteosarcoma (P < 0.05).
		                        		
		                        			CONCLUSION
		                        			RHPN2 is highly expressed in osteosarcoma cells to promote cell proliferation and migration and inhibits cell apoptosis. A high expression of RHPN2 is associated with a poorer prognosis of the patients with osteosarcoma.
		                        		
		                        		
		                        		
		                        			Adaptor Proteins, Signal Transducing/metabolism*
		                        			;
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Apoptosis
		                        			;
		                        		
		                        			Bone Neoplasms/metabolism*
		                        			;
		                        		
		                        			Carcinogenesis
		                        			;
		                        		
		                        			Cell Line, Tumor
		                        			;
		                        		
		                        			Cell Movement/physiology*
		                        			;
		                        		
		                        			Cell Proliferation/physiology*
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Immediate-Early Proteins
		                        			;
		                        		
		                        			Mice
		                        			;
		                        		
		                        			Mice, Nude
		                        			;
		                        		
		                        			Osteosarcoma/metabolism*
		                        			;
		                        		
		                        			RNA, Small Interfering/genetics*
		                        			
		                        		
		                        	
2.Underlying Mechanisms of Memory Deficits Induced by Etomidate Anesthesia in Aged Rat Model: Critical Role of Immediate Early Genes.
Xu LI ; Fen LU ; Wei LI ; Jun XU ; Xiao-Jing SUN ; Ling-Zhi QIN ; Qian-Lin ZHANG ; Yong YAO ; Qing-Kai YU ; Xin-Liang LIANG
Chinese Medical Journal 2016;129(1):48-53
BACKGROUNDEtomidate (R-1-[1-ethylphenyl] imidazole-5-ethyl ester) is a widely used anesthetic drug that had been reported to contribute to cognitive deficits after general surgery. However, its underlying mechanisms have not been fully elucidated. In this study, we aimed to explore the neurobiological mechanisms of cognitive impairments that caused by etomidate.
METHODSA total of 30 Sprague-Dawley rats were used and divided into two groups randomly to receive a single injection of etomidate or vehicle. Then, the rats' spatial memory ability and neuronal survival were evaluated using the Morris water maze test and Nissl staining, respectively. Furthermore, we analyzed levels of oxidative stress, as well as cyclic adenosine 3',5'-monophosphate response element-binding (CREB) protein phosphorylation and immediate early gene (IEG, including Arc, c-fos, and Egr1) expression levels using Western blot analysis.
RESULTSCompared with vehicle-treated rats, the etomidate-treated rats displayed impaired spatial learning (day 4: 27.26 ± 5.33 s vs. 35.52 ± 3.88 s, t = 2.988, P = 0.0068; day 5: 15.84 ± 4.02 s vs. 30.67 ± 4.23 s, t = 3.013, P = 0.0057; day 6: 9.47 ± 2.35 s vs. 25.66 ± 4.16 s, t = 3.567, P = 0.0036) and memory ability (crossing times: 4.40 ± 1.18 vs. 2.06 ± 0.80, t = 2.896, P = 0.0072; duration: 34.00 ± 4.24 s vs. 18.07 ± 4.79 s, t = 3.023, P = 0.0053; total swimming distance: 40.73 ± 3.45 cm vs. 27.40 ± 6.56 cm, t = 2.798, P = 0.0086) but no neuronal death. Furthermore, etomidate did not cause oxidative stress or deficits in CREB phosphorylation. The levels of multiple IEGs (Arc: vehicle treated rats 100%, etomidate treated rats 86%, t = 2.876, P = 0.0086; c-fos: Vehicle treated rats 100%, etomidate treated rats 72%, t = 2.996, P = 0.0076; Egr1: Vehicle treated rats 100%, etomidate treated rats 58%, t = 3.011, P = 0.0057) were significantly reduced in hippocampi of etomidate-treated rats.
CONCLUSIONOur data suggested that etomidate might induce memory impairment in rats via inhibition of IEG expression.
Anesthesia ; adverse effects ; Animals ; Etomidate ; adverse effects ; Hippocampus ; drug effects ; metabolism ; Hypnotics and Sedatives ; adverse effects ; Immediate-Early Proteins ; genetics ; metabolism ; Maze Learning ; drug effects ; Memory Disorders ; chemically induced ; genetics ; Rats ; Rats, Sprague-Dawley
3.B-cell translocation gene 2 positively regulates GLP-1-stimulated insulin secretion via induction of PDX-1 in pancreatic beta-cells.
Seung Lark HWANG ; Okyun KWON ; Sun Gyun KIM ; In Kyu LEE ; Yong Deuk KIM
Experimental & Molecular Medicine 2013;45(5):e25-
		                        		
		                        			
		                        			Glucagon-like peptide-1 (GLP-1) is a potent glucoincretin hormone and an important agent for the treatment of type 2 diabetes. Here we demonstrate that B-cell translocation gene 2 (BTG2) is a crucial regulator in GLP-1-induced insulin gene expression and insulin secretion via upregulation of pancreatic duodenal homeobox-1 (PDX-1) in pancreatic beta-cells. GLP-1 treatment significantly increased BTG2, PDX-1 and insulin gene expression in pancreatic beta-cells. Notably, adenovirus-mediated overexpression of BTG2 significantly elevated insulin secretion, as well as insulin and PDX-1 gene expression. Physical interaction studies showed that BTG2 is associated with increased PDX-1 occupancy on the insulin gene promoter via a direct interaction with PDX-1. Exendin-4 (Ex-4), a GLP-1 agonist, and GLP-1 in pancreatic beta-cells increased insulin secretion through the BTG2-PDX-1-insulin pathway, which was blocked by endogenous BTG2 knockdown using a BTG2 small interfering RNA knockdown system. Finally, we revealed that Ex-4 and GLP-1 significantly elevated insulin secretion via upregulation of the BTG2-PDX-1 axis in pancreatic islets, and this phenomenon was abolished by endogenous BTG2 knockdown. Collectively, our current study provides a novel molecular mechanism by which GLP-1 positively regulates insulin gene expression via BTG2, suggesting that BTG2 has a key function in insulin secretion in pancreatic beta-cells.
		                        		
		                        		
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Gene Expression Regulation/drug effects
		                        			;
		                        		
		                        			Glucagon-Like Peptide 1/*pharmacology
		                        			;
		                        		
		                        			Homeodomain Proteins/*genetics/metabolism
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Immediate-Early Proteins/genetics/*metabolism
		                        			;
		                        		
		                        			Insulin/genetics/*secretion
		                        			;
		                        		
		                        			Insulin-Secreting Cells/drug effects/*metabolism
		                        			;
		                        		
		                        			Male
		                        			;
		                        		
		                        			Mice
		                        			;
		                        		
		                        			Mice, Inbred C57BL
		                        			;
		                        		
		                        			Peptides/pharmacology
		                        			;
		                        		
		                        			Promoter Regions, Genetic/genetics
		                        			;
		                        		
		                        			Protein Binding/drug effects/genetics
		                        			;
		                        		
		                        			Rats
		                        			;
		                        		
		                        			Trans-Activators/*genetics/metabolism
		                        			;
		                        		
		                        			Tumor Suppressor Proteins/genetics/*metabolism
		                        			;
		                        		
		                        			Venoms/pharmacology
		                        			
		                        		
		                        	
4.Effect of EBV immediate-early protein Zta on the cell cycle of Daudi cells and its mechanisms.
Qing-wei GUO ; Jin-dong GUO ; Xue-mei LIU ; Yun-ze LANG ; Hong-xia ZHANG ; Guo-sheng JIANG
Chinese Journal of Hematology 2012;33(1):47-50
OBJECTIVETo investigate the effect of EBV immediate-early protein Zta on cell cycle of Daudi cells and the involved mechanisms.
METHODSThe expression vector encoding Zta was constructed and electroporated into Daudi cells. Flow cytometric analysis was used to detect the cell cycle, Western blot to the protein levels of p21, Rb and E2F-1.
RESULTSThe vector was constructed successfully, the expression of Zta protein inhibited the proliferation of Daudi cells and promoted cell cycle from G(0)/G(1) phase \[(30.0 ± 3.4)%\] to S phase \[(47.7 ± 1.1)%\]. Meanwhile, Rb expression was significantly downregulated, E2F-1 and p21 expression upregulated by Zta.
CONCLUSIONZta could promote G(0)/G(1) phase to S phase transition in Daudi cells, which might be associated with the reduced expression of Rb and increased expression of E2F-1 and p21 protein.
Cell Cycle ; genetics ; Cell Division ; Cell Line, Tumor ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; E2F1 Transcription Factor ; metabolism ; Genetic Vectors ; Herpesvirus 4, Human ; genetics ; Humans ; Immediate-Early Proteins ; genetics ; Retinoblastoma Protein ; metabolism ; Trans-Activators ; genetics ; Transcriptional Activation ; Viral Proteins ; genetics
5.Construction of a new oncolytic virus oHSV2hGM-CSF and its anti-tumor effects.
Gui-Lan SHI ; Xiu-Fen ZHUANG ; Xiang-Ping HAN ; Jie LI ; Yu ZHANG ; Shu-Ren ZHANG ; Bin-Lei LIU
Chinese Journal of Oncology 2012;34(2):89-95
OBJECTIVEThe aim of this study was to construct a new oncolytic virus oHSV2hGM-CSF and evaluate its oncolytic activity in vitro and in vivo in parallel with oHSV1hGM-CSF.
METHODSoHSV2hGM-CSF was a replication-competent, attenuated HSV2 based on the HG52 virus (an HSV2 strain). It was engineered to be specific for cancer by deletion of the viral genes ICP34.5 and ICP47 and insertion of the gene encoding hGM-CSF. To measure the in vitro killing effect of the virus, 15 human tumor cell lines (HeLa, Eca-109, PG, HepG2, SK/FU, CNE-2Z, PC-3, SK-OV3, A-549, 786-0, MCF-7, Hep-2, HT-29, SK-Mel-28, U87-MG) and mouse melanoma (B16R) cell line were seeded into 24-well plates and infected with viruses at MOI = 1 (multiplicity of infection, MOI), or left uninfected. The cells were harvested 24 and 48 hours post infection, and observed under the microscope. For animal studies, the oncolytic viruses were administered intratumorally (at 3-day interval) at a dose of 2.3 x 10(6) PFU (plaque forming unit, PFU) for three times when the tumor volume reached 7-8 mm3. The tumor volume was measured at 3-day intervals and animal survival was recorded.
RESULTSBoth oHSV2hCM-CSFand oHSV1hGM-CSF induced widespread cytopathic effects at 24 h after infection. OHSV2hGM-CSF, by contrast, produced more plaques with a syncytial phenotype than oHSV1hGM-CSF. In the in vitro killing experiments for the cell lines HeLa, HepG2, SK-Mel-28, B16R and U87-MG, oHSV2hGM-CSF eradicated significantly more cells than oHSV1hGM-CSF under the same conditions. For the mouse experiments, it was observed that oHSV2hGM-CSF significantly inhibited the tumor growth. At 15 days after B16R tumor cells inoculation, the tumor volumes of the PBS, oHSV1hGCM-CSF and oHSV2hGM-CSF groups were (374.7 +/- 128.24) mm3, (128.23 +/- 45.32) mm3 (P < 0.05, vs. PBS group) or (10.06 +/- 5.1) mm3 (P < 0.01, vs. PBS group), respectively (mean +/- error). The long term therapeutic effect of oHSV2hGM-CSF on the B16R animal model was evaluated by recording animal survival over 110 days after tumor cells inoculation whereas all the mice in the PBS group died by day 22 (P < 0.01). The anti-tumor mechanism of the newly constructed oHSV2hGM-CSF against B16R cell tumor appeared to include the directly oncolytic activity and the induction of anti-tumor immunity to some degree.
CONCLUSIONThe findings of our study demonstrate that the newly constructed oHSV2hGM-CSF has potent anti-tumor activity in vitro to many tumor cell lines and in vive to the transplanted B16R tumor models.
Animals ; Cell Line, Tumor ; Female ; Gene Deletion ; Genetic Engineering ; Granulocyte-Macrophage Colony-Stimulating Factor ; genetics ; Herpesvirus 2, Human ; genetics ; immunology ; Humans ; Immediate-Early Proteins ; genetics ; metabolism ; Melanoma, Experimental ; pathology ; therapy ; virology ; Mice ; Mice, Inbred C57BL ; Oncolytic Virotherapy ; methods ; Oncolytic Viruses ; genetics ; physiology ; Random Allocation ; Tumor Burden ; Viral Proteins ; genetics ; metabolism ; Xenograft Model Antitumor Assays
6.The potential link between PML NBs and ICP0 in regulating lytic and latent infection of HSV-1.
Shuai WANG ; Jing LONG ; Chun-fu ZHENG
Protein & Cell 2012;3(5):372-382
		                        		
		                        			
		                        			Herpes simplex virus type 1 (HSV-1) is a common human pathogen causing cold sores and even more serious diseases. It can establish a latent stage in sensory ganglia after primary epithelial infections, and reactivate in response to stress or sunlight. Previous studies have demonstrated that viral immediate-early protein ICP0 plays a key role in regulating the balance between lytic and latent infection. Recently, It has been determined that promyelocytic leukemia (PML) nuclear bodies (NBs), small nuclear sub-structures, contribute to the repression of HSV-1 infection in the absence of functional ICP0. In this review, we discuss the fundamentals of the interaction between ICP0 and PML NBs, suggesting a potential link between PML NBs and ICP0 in regulating lytic and latent infection of HSV-1.
		                        		
		                        		
		                        		
		                        			Herpes Simplex
		                        			;
		                        		
		                        			virology
		                        			;
		                        		
		                        			Herpesvirus 1, Human
		                        			;
		                        		
		                        			genetics
		                        			;
		                        		
		                        			physiology
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Immediate-Early Proteins
		                        			;
		                        		
		                        			metabolism
		                        			;
		                        		
		                        			Intranuclear Inclusion Bodies
		                        			;
		                        		
		                        			metabolism
		                        			;
		                        		
		                        			virology
		                        			;
		                        		
		                        			Leukemia, Promyelocytic, Acute
		                        			;
		                        		
		                        			metabolism
		                        			;
		                        		
		                        			Ubiquitin-Protein Ligases
		                        			;
		                        		
		                        			metabolism
		                        			;
		                        		
		                        			Virus Latency
		                        			;
		                        		
		                        			physiology
		                        			
		                        		
		                        	
7.Effects of lanthanum chloride on the expression of immediate early genes in the hippocampus of rats.
Jing-Hua YANG ; Qiu-Fang LIU ; Sheng-Wen WU ; Li-Feng ZHANG ; Yuan CAI
Chinese Journal of Preventive Medicine 2011;45(4):340-343
OBJECTIVETo study influence of lanthanum chloride (LaCl(3)) on the expression of immediate early genes (IEGs) including c-jun, early growth response gene 1 (Egr1) and activity-regulated cytoskeletal gene (Arc) in the hippocampus of rats, and discuss the mechanism of LaCl(3) undermining learning and memory capability.
METHODSForty female Wistar adult rats were divided into control group, low LaCl(3)-contaminated group (0.25%), medium LaCl(3)-contaminated group (0.50%), and high LaCl(3)-contaminated group (1.00%) by randomized design. Each group had ten female rats along with five male rats and mated by the ratio of 2:1. The amounts of pups in the above four groups were 80, 83, 78 and 75 separately. The pups in respective group were La-dyed by lactation, and then the pups in LaCl(3)-contaminated groups drank 0.25%, 0.50% and 1.00% LaCl(3) separately for one month. Learning and memory capability of pups were measured in jumping stairs experiment. Hippocampal lanthanum content was determined by inductively coupled plasma mass spectrometry (ICP-MS). Hippocampal c-jun, Egr1 and Arc mRNA expression was detected by RT-PCR, and corresponding protein expression was measured by Western blotting method.
RESULTSIn the jumping stairs experiment, pups in 0.25%, 0.50% and 1.00% LaCl(3)-contaminated groups respectively made (1.75 ± 0.71), (2.38 ± 0.92) and (3.00 ± 0.76) mistakes; significantly higher than control group (1.25 ± 0.46) (q values were 4.386, 6.793, P < 0.05). However, the incubation period of 0.25%, 0.50% and 1.00% LaCl(3)-contaminated groups were (174.13 ± 33.72), (139.25 ± 45.83) and (75.50 ± 18.56) respectively, which were all significantly lower than that of control group (206.75 ± 20.47) (q values were 2.958, 6.121, 11.902, P < 0.05). Hippocampal c-jun mRNA expression were (0.89 ± 0.08), (0.77 ± 0.12), (0.58 ± 0.14) and (0.29 ± 0.10); while the c-jun protein expression were (0.72 ± 0.13), (0.64 ± 0.11), (0.43 ± 0.11) and (0.31 ± 0.14), and the Egr1 mRNA expression were (0.78 ± 0.09), (0.61 ± 0.13), (0.53 ± 0.10) and (0.22 ± 0.08), Egr1 protein expression were (0.65 ± 0.18), (0.40 ± 0.15), (0.32 ± 0.13) and (0.14 ± 0.09) in 0.25%, 0.50% and 1.00% LaCl(3)-contaminated groups; and all of which presented a dose-effect relationship that the correlation coefficients of these parameters with dose were -0.900 (t = 11.309, P = 0.000), -0.969 (t = 7.058, P = 0.000), -0.898 (t = 11.179, P = 0.000) and -0.962 (t = 6.739, P = 0.000).
CONCLUSIONLaCl(3) undermines the learning and memory capability of rats, which is possibly related to lower expression of c-jun and Egr1 gene and protein induced by lanthanum in hippocampus.
Animals ; Early Growth Response Protein 1 ; metabolism ; Female ; Gene Expression ; Genes, Immediate-Early ; drug effects ; genetics ; Hippocampus ; drug effects ; metabolism ; Lanthanum ; pharmacology ; Learning ; drug effects ; Male ; Memory ; drug effects ; Proto-Oncogene Proteins c-jun ; metabolism ; Rats ; Rats, Wistar
8.SiRNA targeting ICP4 attenuates HSV-1 replication.
Yu-tao LIU ; Bo SONG ; Ya-lun WANG ; Yu-ming XU ; Zhi-qiang HAN ; Xin-yu ZHAO ; Li-jie JIA
Chinese Journal of Virology 2010;26(3):163-169
		                        		
		                        			
		                        			HSV-1, a neurotropic virus, always leads to severe nervous symptoms. It is hard to completely eradicate the latent viruses after conventional therapy so that recurrence is inevitable. ICP is a key regulator for HSV replication and transcription that determines the cytolytic infection or latent state. In search of new anti-virus strategy targeting HSV-1ICP4, two pairs of siRNA were designed, and a recombinant eukaryotic lentiviral expression plasmid pLKO-puro(r)-hU6-siRNA was constructed. Vero cells were transfected with the designed siRNAs by Lipofectamine 2000 and four stable monoclonal cell lines were established by puromycin screening method. The ICP4 expression at mRNA level was detected with real-time PCR, and the HSV-1 replication was measured with TCID50 assay. SiRNA was shown as an effective way to inhibit the expression of ICP4 in monoclonal cell lines. Meanwhile, HSV-1 replication was significantly inhibited when ICP4 was shut down by siRNA. We conclude that siRNA targeting ICP4 attenuates HSV-1 replication. Further more, multi-site siRNAs show stronger inhibitory effect on viral replication, which may be an effective and feasible approach for biological anti-viral drugs.
		                        		
		                        		
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Base Sequence
		                        			;
		                        		
		                        			Cercopithecus aethiops
		                        			;
		                        		
		                        			Genetic Therapy
		                        			;
		                        		
		                        			Genetic Vectors
		                        			;
		                        		
		                        			genetics
		                        			;
		                        		
		                        			Herpesvirus 1, Human
		                        			;
		                        		
		                        			physiology
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Immediate-Early Proteins
		                        			;
		                        		
		                        			deficiency
		                        			;
		                        		
		                        			genetics
		                        			;
		                        		
		                        			RNA Interference
		                        			;
		                        		
		                        			RNA, Messenger
		                        			;
		                        		
		                        			genetics
		                        			;
		                        		
		                        			metabolism
		                        			;
		                        		
		                        			RNA, Small Interfering
		                        			;
		                        		
		                        			genetics
		                        			;
		                        		
		                        			Vero Cells
		                        			;
		                        		
		                        			Virus Replication
		                        			;
		                        		
		                        			genetics
		                        			
		                        		
		                        	
9.Dracorhodin perchlorate inhibit high glucose induce serum and glucocorticoid induced protein kinase 1 and fibronectin expression in human mesangial cells.
Yifeng XIE ; Quansheng WANG ; Jianguo LIU ; Jiwen XIE ; Kaming XUE ; Qing TANG
China Journal of Chinese Materia Medica 2010;35(15):1996-2000
OBJECTIVETo investigate the effect of dracorhodin perchlorate (DP) on inhibiting high glucose-induced serum and glucocorticoid induced protein kinase 1 (SGK1) and fibronectin (FN) expression in human mesangial cells (HMC), and its mechanism of prevention and treatment on renal fibrosis in diabetic nephropathy (DN) .
METHODThe HMC were divided into normal glucose group (NG group, 5.5 mmol x L(-1) D-glucose), normal glucose +low DP group (NG + LDP group, 5.5 mmol x L(-1) D-glucose +7.5 micromol x L(-1) DP), normal glucose +high DP group (NG + HDP group, 5.5 mmol x L(-1) D-glucose + 15 micromol x L(-1) DP), high glucose group (HG group,25 mmol x L(-1) D-glucose), high glucose +low DP group (HG + LDP group, 25 mmol x L(-1) D-glucose + 7.5 micromol x L(-1) DP)and high glucose +high DP group (HG +HDP group, 25 mmol x L(-1) D-glucose + 15 micromol x L(-1) DP). Each group was examined at 24 hours. The levels of SGK1 and FN mRNA was detected by real-time fluorescence quantitative PCR,and the expression of SGK1 and FN protein was detected by Western blot or indirect immunofluorescence.
RESULTA basal level of SGK1 and FN in HMC were detected in NG group, and the level of SGK1 and FN mRNA and protein were not evidently different compared to that of NG group adding 7.5 micromol x L(-1) DP for 24 hours. On the other hand, the levels of SGK1 and FN mRNA and protein were obviously decreased by adding 15 micromol x L(-1) DP for 24 hours. Compared to NG group, the levels of SGK1 and FN mRNA and protein were increased in HG group after stimulating for 24 hours (P < 0.01). Compared to HG group, the level of SGK1 and FN mRNA and protein were evidently reduced in HG + LDP and HG + HDP groups by adding 7.5 micromol x L(-1) DP and 15 micromol x L(-1) DP for 24 hours (P < 0.01).
CONCLUSIONDracorhodin perchlorate can inhibit high glucose-induced serum and glucocorticoid induced protein kinase 1 (SGK1) and fibronectin(FN) expression in human mesangial cells, and this may be part of the mechanism of preventing and treating renal fibrosis of DN.
Benzopyrans ; pharmacology ; Cell Line ; Diabetic Nephropathies ; drug therapy ; enzymology ; genetics ; metabolism ; Down-Regulation ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Fibronectins ; biosynthesis ; genetics ; Gene Expression ; drug effects ; Glucose ; metabolism ; Humans ; Immediate-Early Proteins ; genetics ; metabolism ; Mesangial Cells ; drug effects ; enzymology ; metabolism ; Perchlorates ; pharmacology ; Protein-Serine-Threonine Kinases ; genetics ; metabolism
10.Phosphorylation of Rictor at Thr1135 impairs the Rictor/Cullin-1 complex to ubiquitinate SGK1.
Daming GAO ; Lixin WAN ; Wenyi WEI
Protein & Cell 2010;1(10):881-885
		                        		
		                        			
		                        			The Rictor/mTOR complex plays a pivotal role in a variety of cellular functions including cellular metabolism, cell proliferation and survival by phosphorylating Akt at Ser473 to fully activate the Akt kinase. However, its upstream regulatory pathways as well as whether it has additional function(s) remain largely unknown. We recently reported that Rictor contains a novel ubiquitin E3 ligase activity by forming a novel complex with Cullin-1, but not with other Cullin family members. Furthermore, we identified SGK1 as its downstream target. Interestingly, Rictor, but not Raptor or mTOR, promotes SGK1 ubiquitination. As a result, SGK1 expression is elevated in Rictor(-/-) MEFs. We further defined that as a feedback mechanism, Rictor can be phosphorylated by multiple AGC family kinases including Akt, S6K and SGK1. Phosphorylation of Rictor at the Thr1135 site did not affect its kinase activity towards phosphorylating its conventional substrates including Akt and SGK1. On the other hand, it disrupted the interaction between Rictor and Cullin-1. Consequently, T1135E Rictor was defective in promoting SGK1 ubiquitination and destruction. This finding further expands our knowledge of Rictor's function. Furthermore, our work also illustrates that Rictor E3 ligase activity could be governed by specific signaling kinase cascades, and that misregulation of this process might contribute to SGK overexpression which is frequently observed in various types of cancers.
		                        		
		                        		
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Carrier Proteins
		                        			;
		                        		
		                        			metabolism
		                        			;
		                        		
		                        			Cell Proliferation
		                        			;
		                        		
		                        			Cells, Cultured
		                        			;
		                        		
		                        			Cullin Proteins
		                        			;
		                        		
		                        			genetics
		                        			;
		                        		
		                        			metabolism
		                        			;
		                        		
		                        			Fibroblasts
		                        			;
		                        		
		                        			metabolism
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Immediate-Early Proteins
		                        			;
		                        		
		                        			metabolism
		                        			;
		                        		
		                        			Mice
		                        			;
		                        		
		                        			Phosphorylation
		                        			;
		                        		
		                        			Protein-Serine-Threonine Kinases
		                        			;
		                        		
		                        			genetics
		                        			;
		                        		
		                        			metabolism
		                        			;
		                        		
		                        			Proto-Oncogene Proteins c-akt
		                        			;
		                        		
		                        			genetics
		                        			;
		                        		
		                        			metabolism
		                        			;
		                        		
		                        			Rapamycin-Insensitive Companion of mTOR Protein
		                        			;
		                        		
		                        			TOR Serine-Threonine Kinases
		                        			;
		                        		
		                        			genetics
		                        			;
		                        		
		                        			metabolism
		                        			;
		                        		
		                        			Ubiquitin
		                        			;
		                        		
		                        			genetics
		                        			;
		                        		
		                        			metabolism
		                        			;
		                        		
		                        			Ubiquitination
		                        			
		                        		
		                        	
            
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