Relationship between HDL subclasses and TC/HDL-C,TG/HDL-C ratio

AIM: To study the relationship between HDL subclasses and TC/HDL-C, TG/HDL-C ratio in serum. METHODS: Apolipoprotein (apo) A-Ⅰ contents of serum HDL subclasses in 292 subjects were determined by two-dimensional gel electrophoresis associated with immunodection method. RESULTS: Compared with low TC/HDL-C ratio subgroup, apoA-Ⅰcontents of preβ1-HDL (P<0.01, in middle or high subgroup) and HDL3a (P<0.05, in high subgroup) were significantly higher, but those of HDL2b (P<0.01, in middle or high subgroup) and HDL2a (P<0.01, in high subgroup) were significantly lower. Compared with middle TC/HDL-C ratio subgroup, apoA-Ⅰ contents of preβ1-HDL, HDL3a were significantly higher (P<0.01, P<0.05), but those of HDL2a and HDL2b were significantly lower (P<0.01, P<0.01) in high subgroup. Compared with low TG/HDL-C ratio subgroup, apoA-Ⅰ contents of preβ1-HDL, HDL3a were significantly higher (P<0.01, P<0.05, in high subgroup), but those of HDL2a and HDL2b were significantly lower (P<0.01, in middle or high subgroup). Compared with middle TG/HDL-C ratio subgroup, apoA-Ⅰ contents of preβ1-HDL, HDL3a were significantly higher (P<0.01, P<0.05), but those of HDL2a and HDL2b were significantly lower (P<0.01). In addition, TC, TG, TC/HDL-C ratio and TG/HDL-C ratio showed a positive correlation with apoA-Ⅰ contents of small-sized preβ1-HDL and a negative correlation with those of large-sized HDL2b, but it was reversed for HDL-C. CONCLUSION: When TC/HDL-C>5 or TG/HDL-C>2.2 in serum, the particle size of HDL shifted towards smaller sizes, which indicates that reverse cholesterol transport might be weakened and HDL maturation might be abnormal.     

Influence of low molecular weight heparin on the lipometabolism in hemodialysis patients

AIM:To compare the influence of low molecular weight heparin(LMWH) (Fragmin, Kabi Chemie Corp., MÜnchen) and conventional heparin (CH) on anticoagulation and lipometabolism in patients on chronic hemodialysis (CHD).METHODS:27 patients on CHD underwent 6 months LMWH-treatment, then switched to 6 months CH-treatment for anticoagulation during dialysis. Total plasma cholesterol (TCh), triglyceride (TG), high-density lipoprotein cholesterol(HDL-Ch), HDL₂-Ch, HDL₃-Ch, low density lipoprotein, LDL (LDL), apolipoprotein A₁ (Apo-L A₁), Apo-L B, hemoglobin(Hb), platelet(Plt), kaolin partial thromboplastin time(KPTT), bleed time (BT), coagulation time(CT), alanine transaminase(ALT), aspartate aminotransferase(AST) were measured every two months.RESULTS:During LMWH-treatment,whole KPTT,BT,CT,TCh,TG,LDL,Apo-L A1 and Apo-L B decreased significantly.Symptoms such as haemorrhage and itching were alleviated.However,after switching back to CH,the parameters reversed,HDL-Ch and the subfractions of HDL-Ch remained nearly unchanged.CONCLUSION:LMWH could improve the anticoagulative effect and lipometabolism in CHD patients. and alleviated the symptoms such as haemorrhage and itching. More importantly, the Lifequality of CHD patients could be improved.     

Effects of HDL from patients with coronary artery disease on lipid deposition and apoptosis in mouse peritoneal macrophages

AIM: To compare the effects of high-density lipoprotein (HDL) from healthy subjects (HDL_heathy) and HDL from the patients with coronary artery disease (HDL_CAD) on the lipid deposition and apoptosis in mouse peritoneal macrophages. METHODS: HDL was isolated from healthy subjects, stable CAD patients (HDL_SCAD) and acute myocar-dial infarction patients (HDL_AMI). The accumulation of intracellular lipids was determined by oil red O staining. The apoptosis of macrophages was measured by fluorescence microscopy with annexin-V/PI staining. DCHF-DA, a redox-sensitive dye, was used to detect intracellular reactive oxygen species (ROS) levels. The protein expression of ATP-binding cassette transporter (ABC) A1, ABCG1, Bcl-2 and Bax was determined by Western blot analysis. RESULTS: Lipid deposition in the macrophages was increased significantly after oxidized low-density lipoprotein (ox-LDL) treatment, and the expression of ABCA1 and ABCG1 was up-regulated (P<0.05). Compared with ox-LDL treatment alone, HDL_healthy decreased lipid deposition in the macrophages and up-regulated the expression of ABCA1 and ABCG1 (P<0.05), while treatment with HDL_SCAD or HDL_AMI further decreased lipid deposition in the macrophages and down-regulated the expression of ABCA1 and ABCG1 (P<0.05). Compared with HDL_SCAD treatment, lipid deposition in the macrophages was further increased after HDL_AMI treatment, and the expression of ABCA1 and ABCG1 was down-regulated (P<0.05). HDL_healthy decreased the levels of intracellular ROS and apoptosis by increasing the level of antiapoptotic protein Bcl-2 and reducing the expression of proapoptotic protein Bax. In contrast, HDL_SCAD and HDL_AMI had opposite effects on the intracellular ROS, the cell apoptosis and the expression of apoptosis-related proteins Bcl-2 and Bax. CONCLUSION: HDL_CAD promotes lipid accumulation in macrophages and induces macrophage apoptosis. These findings provide novel insights into mechanisms leading to altered vascular effects of HDL in CAD.     

Effects of Astragalus injection combined with puerarin injection on expression of BMP-7 and TGF-β1 in type 2 diabetic KKAy mouse kidney

AIM: To observe the effects of Astragalus injection combined with puerarin injection on the expression of transforming growth factor beta 1 (TGF-β₁) and bone morphogenetic protein 7 (BMP-7) in the kidney of type 2 diabetic KKA^y mouse. METHODS: The male KKA^y mice of 14 weeks old were randomly divided into model group and Astragalus injection combined with puerarin injection treatment (Astragalus+puerarin) group. The age-matched male C57BL/6J mice were selected as normal group. The general conditions and body weight of the mice were observed. Blood glucose (BG), triglyceride (TG), cholesterol (TC) and serum creatinine (SCr) were examined at the 20th, 24th and 28th week. The protein expression of renal TGF-β₁ was determined by immunohistochemical method. The mRNA expression of BMP-7 and TGF-β₁ was detected by RT-PCR. RESULTS: Compared with normal group, the body weight, BG, TG, TC and SCr increased significantly in model group. TGF-β₁ expression at protein and mRNA levels was increased, while mRNA expression of BMP-7 was decreased in KKA^y mice. Compared with model group, the body weight, BG, TG, TC and SCr reduced in Astragalus+puerarin group. The mRNA expression of BMP-7 in the renal tissues was higher, and TGF-β₁ expression at mRNA and protein levels was significantly lower in Astragalus+puerarin group than those in model group. CONCLUSION: Astragalus injection combined with puerarin injection has renal protective effects on type 2 diabetic KKA^y mice. The mechanism may be related to restoring BMP-7 expression and reducing the overexpression of TGF-β₁ in renal tissues.     

The interrelationships between serum HDL subpopulations and triacyglycerol

AIM: To Study the influence of plasma TG level on the contents of serum HDL subpopulations. METHODS: Classified by the contents of serum TG, the serum level of HDL subpopulations in 106 normal TC and 183 high TC subjects were analyzed by two-dimensional gel electrophoresis coupled with immunodection method. RESULTS: The apo-AⅠcontents of per-β1-HDL, HDL3c, HDL3b and HDL3a were higher in a certain extent in TC high subjects vs corresponding TC desirable subjects. The apo-AⅠ contents of per-β1-HDL （in borer-line high TG subgroup） and HDL3b （in very high TG subgroup） were significantly higher (P<0.05 or P<0.01), while the apo-AⅠ contents of HDL2b and HDL2a were all lower in TC high subjects vs corresponding TC normal subjects. With the increase in plasma TG levels, the apoA-Ⅰ content of pre-β1-HDL increased, and it was significantly higher (P<0.05 or P<0.01) in borderline-high TG(except TC desirable subjects), high TG and very high TG subgroups vs corresponding normal TG subgroup. Contents of HDL3b and HDL3a had the same tendency, and in TC high subjects contents of HDL3b (in very high TG subgroup) and HDL3a (in every subgroups, in which levels of TG were higher) were significantly higher (P＜0.05 and P＜0.01） than in normal TG subgroup. On contrast, the apoA-Ⅰcontents of HDL2b and HDL2a following with the increase of plasma TG levels tended to become lower. Contents of HDL2b were significantly lower (P<0.05) in high TG subgroup and very high TG subgroup vs corresponding normal TG subgroup, and in TC high subjects contents of HDL2a were significantly lower (P<0.05) in very high TG subgroups vs normal TG subgroup. CONCLUSION: Our data show the general shift toward smaller size of HDL particle size with the increase in TC and TG levels. Contents of TC and TG are very important to contents of HDL subclasses.     

Eeffect of HMGB1 on expression of NF-κB in BV-2 cells stimulated with Aβ25-35

AIM: To investigate the effect of high mobility group box-1 protein (HMGB1) on the expression of nuclear factor-κB (NF-κB) in BV-2 cells stimulated with amyloid β-protein (Aβ)_25-35. METHODS: Cultured BV-2 cells in logarithmic growth phase were divided into 4 groups:normal cell group (without any treatment), model group (treated with Aβ_25-35 at 40 μmol/L), RNA interference (RNAi) group (conducted with HMGB1-siRNA followed by Aβ_25-35 stimulation) and solvent control group (treated with 0.1% DMSO). After treatment with Aβ_25-35 for 24 h, the protein levels of HMGB1 and NF-κB in BV-2 cells were determined by Western blot. RESULTS: Aβ_25-35 at 40 μmol/L was used to stimulate BV-2 cells. The GFP fluorescence-tagged HMGB1-siRNA (30 nmol/L) was used to transfect BV-2 cells and its transfection efficiency was about 80%~90%. The results of Western blot showed that the protein level of HMGB1 was significantly decreased after the interference of siRNA fragment (P<0.05). The protein levels of HMGB1 and nucleic NF-κB p65 were dramatically increased in BV-2 cells stimulated with Aβ_25-35 (P<0.05). After RNA interference with HMGB1, the expression of HMGB1 and nucleic NF-κB p65 were significantly decreased in BV-2 cells stimulated with Aβ_25-35 (P<0.05). CONCLUSION: RNA interference with HMGB1 reduces the expression of nucleic NF-κB in BV-2 cells stimulated with Aβ_25-35.     

Subclasses of serum HDL in middle and old aged patients with hyperlipidemia in Chengdu City

AIM: To detect the change of composition and ratio of serum HDL subclasses and explore the relationship between these changes and the plasma lipid level in patients with hyperlipidemia. METHODS: The components of subclasses of serum HDL in 172 middle and old aged patients with hyperlipidemia and 115 healthy middle and old aged were determined by dimensional gel electrophoresis associated with immuno-blotting method. RESULTS: Compared to the healthy controls, the contents of pre β1-HDL，　HDL3b and HDL3a were significantly higher (P＜0.05 or P＜0.01), while that of HDL2b was significantly lower (P＜0.01) in middle and old aged patients with hyperlipidemia. The content of pre β1-HDL increased with age in healthy controls, whereas the HDL2b decreased. The content of pre β1-HDL was significantly higher (P＜0.05), while the HDL2b (P＜0.05) was significantly lower in men than in women in patients with hyperlipidemia and the healthy controls. In middle and old aged patients with hyperlipidemia, the content of pre β1-HDL was positively correlated with the serum TG, TC, apoB100, apoCⅡ, apoCⅢ, apoE and TG/HDL-C (r=0.432; r=0.243; r=0.341; r=0.259; r=0.335; r=0.308 and r=0.453, P＜0.05 or P＜0.01), while it was negatively correlated with HDL-C (r=－0.167, P＜0.05). The content of HDL2b was negatively correlated with TG, TC, apoCⅡ, apoCⅢ and TG/HDL-C (r=－0.296; r=－0.156; r=－0.182; r=－0.216; r=－0.203 and r=－0.313, P＜0.05 or P＜0.01), while it was positively correlated with HDL-C (r=0.124, P＜0.05). CONCLUSIONS: The particle of HDL in the middle and old aged patients with hyperlipidemia showed a general shift towards smaller size, which indicated that the reverse cholesterol transport might be weakened. Men had smaller HDL particle size than women.     

Role of P2Y1 receptor in activation of astrocytes induced by Aβ25-35

AIM: To study the role of P2Y₁ receptor in the activation of astrocytes induced by Aβ_25-35.METHODS: Astrocytes were isolated and cultured from newborn Wistar rats and divided into control group, Aβ_25-35 group, MRS2179(P2Y₁receptor inhibitor)+Aβ_25-35 group and MRS2179 group by treating the cells with the corresponding reagents. The expression levels of GFAP and P2Y₁ were determined by the methods of immunohistochemistry, immunofluorescence and Western blotting.RESULTS: No significant change of the astrocyte numbers in all groups was observed. Compared with the control cells, the fluorescence intensity of GFAP significantly increased in Aβ_25-35 group and decreased in both MRS2179+Aβ_25-35 group and MRS2179 group. The expression level of GFAP determined by Western blotting and immunofluorescence showed the similar trend of change in each group. Compared with control group, the expression of P2Y₁ in Aβ_25-35 group was significantly increased (P<0.05), and no significant change between MRS2179+Aβ_25-35 group and MRS2179 group was found (P>0.05).CONCLUSION: Aβ_25-35 activates astrocytes by activation of P2Y₁ receptor.     

Effects of angiotensin II and losartan on collagen synthesis in rat hepatic stellate cells

AIM: To investigate the effects of angiotensin II (Ang II) and AT_1a receptor antagonist (losartan) collagen synthesis in rat hepatic stellate cells (HSCs). METHODS: ① Rat HSCs were isolated, cultured and identified. ② Rat HSCs were incubated in the medium with different concentrations of AngII or losartan, then the quantity of collagen was examined by -proline release assay. RESULTS: ① The yield of HSCs was 2×10⁷-3×10⁷/per rat, their viability and purity was more than 95% and 90%, respectively. ② The yield of collagen in HSCs significantly got a rise in a concentration-dependent manner when HSCs were incubated with AngII (10^－6mol/L-10^－10 mol/L) (P<0.05). While HSCs were influenced by the antagonist of AT_1a (10^－6 mol/L-10^－9 mol/L), the quantity of collagen dropped greatly (P<0.05). CONCLUSIONS: Ang II stimulates HSCs to produce more collagen. Losartan inhibits the cell to synthesize collagen via AT_1a receptor (P<0.05). The results indicate that Ang II may play an important role in the development of hepatic fibrosis, and using AT_1a antagonist may offer a new strategy to prevent hepatic fibrosis.     

Changes in serum TGF β1 in type 2 diabetic patients

AIM: To explore the changes in serum TGF β₁ in type 2 diabetes mellitus. METHODS: Forty-five cases type 2 diabetes mellitus patients were divided into three groups according to urine albumim excretion rate(UAER): normoalbuminuria(NA)group and microalbuminuria(MA) group and macroalbuminuria group (Overt DN). Serum TGF β₁, fasting blood glucose(FBG), HbA_1c,BUN,Cr,Ccr,lipidemia were detected in all cases. RESULTS: Serum TGF β₁ in NA, MA and ODN groups was higher than that in control. Serum TGF β₁ was positive correlation with Cr(r=0.390,P＜0.05), LDL(r=0.503,P＜0.01), HbA_1c (r=0.676,P＜0.01), and UARE(r=0.777,P＜0.01). CONCLUSION: Type 2 diabetes mellitus have a higher serum TGF β₁ than controls, serum TGF β₁ was positive correlation with HbA_1c and injury of renal function.     

Roles of gap junction in TGF-β1-induced proliferation of vascular smooth muscle cells from spontaneous hypertensive rats

AIM: To investigate whether gap junction participates in transforming growth factor β₁(TGF-β₁)-induced proliferation of spontaneous hypertensive rat (SHR) vascular smooth muscle cells (VSMCs). METHODS: The thoracic aorta of the rats were sampled. The primary SHR VSMCs were isolated and cultured in vitro. The cells were divided into 4 groups: control group, TGF-β₁ group,18α-glycyrrhetinic acid(18α-GA) group and TGF-β₁+18α-GA group. The proliferation of SHR VSMCs was observed by the methods of MTT and flow cytometry. The protein expression and co-localization of connexin(Cx)43 and Cx40 in SHR VSMCs were detected by immunofluorescence staining. The protein levels of Cx43 and Cx40 in the cells were also measured by Western blotting. The method of molecular dye transfer (scrape dye transfer method) was applied to detect the function of gap junction in SHR VSMCs. RESULTS: The protein expression of Cx43 and Cx40 in SHR VSMCs was positive and co-localized in the cytoplasm. Compared with control group, the percentage of S-phase detected by cell cycle and A value detected by MTT in TGF-β₁ group were obviously increased (P<0.05), indicating that the proliferation of the cells was enhanced. However, the proliferation of the cells decreased in 18α-GA group (P<0.05). Compared with TGF-β₁ group, the percentage of S-phase and A value in TGF-β₁+18α-GA group were both significantly decreased (P<0.05), indicating that the proliferation of the cells decreased. Compared with control group, the protein expression of Cx43 in TGF-β₁ group was increased (P<0.05), whereas the protein expression of Cx40 was not changed (P>0.05), and the protein expression of Cx43 and Cx40 in 18α-GA group were decreased (P<0.05). Compared with TGF-β₁ group, the expression of Cx43 in TGF-β₁+18α-GA group was significantly decreased (P<0.05),but no difference of the Cx40 protein levels between the two groups was observed. Compared with control group, the function of gap junction detected by scrape dye transfer method in TGF-β₁ group was enhanced (P<0.05), and weakened in 18α-GA group (P<0.05). Compared with the TGF-β₁ group, the function of gap junction in TGF-β₁+18α-GA group was significantly attenuated (P<0.05). CONCLUSION: TGF-β₁ enhances the function of gap junction to stimulate the proliferation of SHR VSMCs through the expression of Cx43 protein. The expression of Cx40 protein may not play a major role in this process.     

Effects of icariin on expression of transforming growth factor β1 and type Ⅳ collagen in diabetic rat testis

AIM: To determine the beneficial effects of icariin on streptozotocin (STZ)-induced diabetic testopathy in rats. METHODS: The diabetic animal model was induced in male Sprague-Dawley rats by an injection of streptozotocin (40 mg/kg, iv). The rats were randomly divided into 3 groups: control group, model group and icariin (80 mg/kg, ig) group. Twelve weeks after injected with streptozotocin, all rats were anaesthetized and killed to remove the testes from scrotum. Serum concentrations of glucose and testosterone, and the levels of succinate dehydrogenase (SDH), acid phosphatase (ACP), γ-glutamyl transpeptidase (γ-GT) and lactate dehydrogenase (LDH) in testes were measured. The morphology of the testicular tissues was observed under light microscope. Immunohistochemistry was employed to determine the protein levels of TGF-β₁ and type Ⅳ collagen. RESULTS: Compared with control group, the content of serum glucose increased while the serum level of testosterone and the activitiy of SDH, ACP, γ-GT and LDH in testis decreased in model group (P<0.01). The histopathological examination showed that the diameters of seminiferous tubules and various grades of spermatocytes in the testis were markedly decreased. Compared with control group, the expression of TGF-β₁ and collagen Ⅳ was significantly increased in model group. These alterations were significantly attenuated in icariin group (P<0.01). CONCLUSION: Icariin evidently relieves testicular damage in rats with diabetic testopathy by improving the secretion of testosterone and reducing the expression of TGF-β₁ and collagen Ⅳ at protein level.     

Effect of Akt/GSK-3β/Snail signaling pathway on EMT in A549/DDP cells mediated by TGF-β1

AIM: To observe the expression of Akt/GSK-3β/Snail signaling pathway-related molecules in cisplatin-resistant cell line A549/DDP mediated by transforming growth factor-β₁ (TGF-β₁), and to explore the association of Akt/GSK-3β/Snail signaling pathway with epithelial-mesenchymal transition (EMT). METHODS: The A549/DDP cells were divided into TGF-β₁ (+) group, TGF-β₁ (-) group and LY294002 group. The morphological changes of A549/DDP cells treated with TGF-β₁ were observed under microscope. The protein expression of E-cadherin and N-cadherin was determined by the methods of immumofluorescence and Western blot. The protein levels of Akt, p-Akt, GSK-3β, p-GSK-3β^Ser9 and Snail were also detected by Western blot. RESULTS: The A549/DDP cells in TGF-β₁ (+) group were dispersive, showed a spindle-like shape and developed pseudopodia. This transformation was conformed to classic EMT markers. Compared with TGF-β₁ (-) group, the protein expression of E-cadherin in TGF-β₁ (+) group was significantly decreased (P<0.05), and N-cadherin was significantly increased (P<0.05). The protein levels of p-Akt, p-GSK-3β^Ser9 and Snail were also significantly increased (P<0.05). Compared with TGF-β₁ (+) group, the protein levels of p-Akt, p-GSK-3β^Ser9 and Snail were significantly decreased in LY294002 group (P<0.05). No difference of Akt and GSK-3β expression between TGF-β₁ (-) group and TGF-β₁ (+) group was observed. CONCLUSION: The mechanism of EMT in A549/DDP cells might be related to Akt/GSK-3β/Snail signaling pathway activated by TGF-β₁.     

Effect of tenuigenin on tau protein phosphorylation at Ser396 site in neurons of AD rats induced by Aβ1-40

AIM:To investigate the effect of tenuigenin(TEN) on hyperphosphorylation of tau protein in neurons of amyloid β-peptide_1-40(Aβ_1-40) -induced Alzheimer disease(AD) rats. METHODS:Aβ_1-40 was injected into hippocampus CA1 region of the rats to establish AD model. TEN at different doses(18.5 mg/kg, 37.0 mg/kg and 74.0 mg/kg) was intragastrically administered. The protein expression of protein kinase A(PKA),protein phosphatase 2A(PP2A), total tau and p-tau(Ser³⁹⁶) in the neurons was observed by the method of immunohistochemistry. The protein content of total tau and p-tau(Ser³⁹⁶), and the expression level of PKA and PP-2A were detected by Western blotting analysis. RESULTS:In Aβ_1-40 group, the level of total tau, the phosphorylation of tau protein and the expression of PKA were significantly increased compared with those in sham operation group. Meanwhile, the expression of PP2A in Aβ_1-40 group was lower than that in sham operation group. In TEN treatment group, the level of total tau, the phosphorylation of tau protein and the expression of PKA were markedly decreased, and the expression of PP2A was increased as compared with Aβ_1-40 group. CONCLUSION:TEN may protect the neurons from the toxic effect of Aβ_1-40 and reduce the hyperphosphorylation of tau(Ser³⁹⁶) in the neurons of AD rats by activating the expression of PP2A and inhibiting the expression of PKA.     

Effect of salvianolic acid B on high glucose-induced phenotypic transition and extracellular matrix secretion in human glomerular mesangial cells

AIM:To investigate the effect of salvianolic acid B (Sal B) on high glucose-induced phenotypic transition and extracellular matrix (ECM) secretion in human glomerular mesangial cells (HGMCs) and the underlying mechanisms. METHODS:HGMCs were randomly divided into control group, high glucose group and high glucose plus high dose, medium dose and low dose of Sal B groups. The HGMCs except those in control group were exposed to high glucose (33.3 mmol/L) for 72 h, while those in Sal B groups were co-incubated with indicated concentrations of Sal B. The protein levels of α-smooth muscle actin (α-SMA), transforming growth factor-β₁ (TGF-β₁) and phosphorylated Smad2 and p38 mitogen-activated protein kinase (MAPK) were determined by Western blot. The secretion levels of collagen type I (Col I), collagen type Ⅲ (Col Ⅲ), fibronectin (FN) and laminin (LN) were measured by ELISA. RESULTS:Exposure to high glucose markedly increased the protein expression of α-SMA, TGF-β₁, Col I, Col Ⅲ, FN and LN in the HGMCs (P<0.01). The phosphorylation levels of Smad2 and p38 MAPK were also significantly increased (P<0.01). Co-incubation with Sal B evidently decreased the protein expression of α-SMA, TGF-β₁, Col I, Col Ⅲ, FN and LN in the HGMCs induced by high glucose (P<0.05 or P<0.01). The phosphorylated levels of Smad2 and p38 MAPK were also reduced noticeably (P<0.05 or P<0.01). CONCLUSION:Sal B significantly suppresses high glucose-induced phenotypic transition and ECM secretion in the HGMCs, which might be attributed, at least partly, to inhibition of TGF-β₁/Smad signaling pathway and p38 MAPK activation.     

Serum lipid levels and ApoB gene Xba I and 3'-VNTR polymorphisms in longevous elderly Han population in Zhejiang

AIM: To study the levels of serum lipids and the effects of apolipoprotein B (ApoB) gene Xba I-restriction fragment length polymorphism (RFLP) and 3'-variable-number tandem repeat (VNTR) polymorphism on serum lipid and apolipoprotein levels in longevous elderly Han population in Zhejiang. METHODS: Physical and laboratory examinations were performed on longevous elders, children of longevous elders, normal control people and children of non-longevous elders, and the Xba I-RFLP and 3'-VNTR polymorphism in ApoB gene were genotyped. RESULTS: The serum levels of triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and ApoB were negatively correlated with longevity (P<0.05), while the level of high-density lipoprotein cholesterol (HDL-C) was positively correlated with longevity (P<0.01). The levels of total cholesterol (TC), LDL-C and ApoB were higher and the HDL-C level was lower in the people with Xba I-RFLP X⁺X^- genotype than those in the people with Xba I-RFLP X^-X^- genotype (P<0.01). The levels of TC, TG, LDL-C and ApoB were higher and the HDL-C level was lower in the people with 3'-VNTR large allele than those in the people with 3'-VNTR minor allele (P<0.01). CONCLUSION: High TG, LDL-C and ApoB levels and low HDL-C level are not conductive to longevity. Serum lipid levels in the people with Xba I-RFLP X^-X^- genotype or 3'-VNTR minor allele are healthy and conductive to longevity.     

Antagonistic effect of thalidomide on TGF-β1-induced change of CTGF gene promoter-binding proteins in HELF cells

AIM:To investigate the antagonistic effect of thalidomide (THD) on the activation of connective tissue growth factor (CTGF) gene promoter induced by transforming growth factor-β₁ (TGF-β₁) in human embryonic lung fibroblasts (HELF). METHODS:Luciferase reporter vector driven by CTGF gene promoter was used to detect the effects of TGF-β₁ and THD on the activity of CTGF gene promoter, and DNA pull-down assay with CTGF gene promoter as a probe was used to analyze the changes of CTGF promoter-binding proteins under different conditions. RESULTS:TGF-β₁ increased the activity of reporter driven by CTGF gene promoter (P<0.01), while THD significantly inhibited TGF-β₁-induced increase in the reporter activity dose-dependently (P<0.01). At the same time, THD had inhibitory effect on the TGF-β₁-induced change of CTGF gene promoter-binding proteins (P<0.05). CONCLUSION:Regulation of CTGF gene promoter-binding proteins takes part in TGF-β₁-induced activation of CTGF gene promoter, while THD has antagonistic effect on this process.     

Study on relationship between expression of PKCα in glomeruli and development of nephropathy in diabetic rats

AIM:To observe the dynamic changes of expression of PKCα, TGF-β₁ and α-SMA in glomeruli of diabetic rats induced by the alloxon and to invesitigate their roles in the diabetic nephropathy(DN).METHODS:Rats were randomly divided into four groups: normal control group (group A), diabetic group of one week (group B), diabetic group of one month (group C), diabetic group of two months (group D). Immunohistochemistry and Western blotting were used to detect the expression of PKCα, TGF-β₁ and α-SMA in renal tissue of all groups. Blood glucose, triglycerides, cholesterol, creatinine and urine protein were analysed by chemical methods. The morphological changes of renal tissue were checked through microscopy.RESULTS:The expression of PKCα and TGF-β₁ in renal tissue of diabetic groups were increased comparing with those of nomal control group(P<0.05). The mesangial cells expressed α-SMA in two months group. Chronologically the expression of PKCα, TGF-β₁ and α-SMA were positively correlative with each other and the impairment of kidney was also observed.CONCLUSIONS: During the DN process the expression of PKCα increased. PKCα raised GFR and the permeability of glomerular filtration membrane which enhanced urinary albumin excretion. PKCα also increased expression of TGF-β and therefore to induce the expression of α-SMA. The appearance of α-SMA was a marker of the phenotypic transform of renal cells.     

Effect of bFGF on human kidney fibroblasts

AIM: To study the effect of bFGF on cell proliferation, secretion of type I collagen and expression of integrin β₁ in human kidney fibroblasts(KFB). METHODS: The KFB was cultured and stimulated by bFGF in vitro. The proliferation and collagen I secreting of KFB, the expression of integrin β₁ were measured by MTT, ELISA and flow cytometer, respectively. RESULTS: bFGF(25-50 μg/L) could obviously stimulate the cell proliferation(P< 0.05), promote the secretion of collagen I(P< 0.05) and enhance the expression of integrin β₁(P< 0.05) in human kidney fibroblast. CONCLUSION: bFGF could induce renal interstitial fibrosis by promoting cell proliferation, secretion of collagen I and integrin β₁ expression of KFB.