Mechanism of Sclerostin/Lrp4 in the regulation of vascular smooth muscle cell calcification / 中华肾脏病杂志

Objective To investigate the possible mechanism of sclerostin/Lrp4 in calcification of VSMC induced by high phosphorus and the protective effect of Ginkgo biloba extract.Methods Aortic vascular smooth muscle cells (VSMCs) of SD rats were extracted and identified.VSMCs were divided into normal control group,high phosphorus induced calcification group (10 mmol/L β-glycerophosphate+50 μg/ml ascorbic acid),and high phosphorus induced calcification+Ginkgo biloba extract intervention group (10 mmol/L β-glycerophosphate+50 μg/ml ascorbic acid+0.5 mg/ml GBE),cultured in different mediums for 14 days.Vonkossa staining and alizarin red staining were used to detect the calcification of VSMCs.The mRNA level of BGP was detected by real time PCR,and the protein expressions of sclerostin and Lrp4 were detected by Western blot.Results Compared with normal control group,vonkossa staining and alizarin red staining showed significant calcium deposition in calcification group.Compared with calcification group,calcium salt deposition was significantly reduced in GBE treatment group.Real time PCR results showed β-catenin and BGP mRNA expressions in VSMC calcification group were higher than those in normal control group (P＜ 0.05).mRNA expressions of β-catenin and BGP in GBE treatment group were lower than those in calcification group (all P ＜ 0.05).Compared with normal control group,the protein expression of sclerostin was increased,but the protein expression of Lrp4 was decreased in calcified group (all P ＜ 0.05).Compared with calcification group,the protein expression of sclerostin decreased and the protein expression of Lrp4 increased in GBE treatment group (all P ＜ 0.05).Conclusions High phosphorus can induce VSMC calcification by activating Wn/β-catenin signaling pathway.Sclerostin/Lrp4 is involved in hyperphosphine-induced VSMC calcification.GBE can reduce the high phosphorus induced VSMC calcification by regulating the Wnt/β-catenin signaling pathway.

Association of high-density lipoprotein and apolipoprotein E genetic variants with age-related macular degeneration / Associação de lipoproteína de alta densidade e variantes genéticas da apolipoproteína E com degeneração macular relacionada à idade

Purpose: This study aimed to evaluate the association of age-related macular degeneration (AMD) with apolipoprotein E (APOE) variants and serum lipid profiles, including levels and fractions of total serum cholesterol (TC), low-density lipoprotein cholesterol (LDLc), and high-density lipoprotein cholesterol (HDLc), and triglycerides (TG). Methods: Genotyping of APOE-HhaI was performed in 134 patients (study group, SG) and 164 individuals without AMD (control group, CG), aged 50-89 years. Lipid profiles were analyzed in a subgroup of 30 subjects of both groups, matched according to age and sex. The significance level was set at P<0.05. Results: APOE E3/E3 was more prevalent (SG=74.6%; CG=77.4%), with no difference between both groups (P=0.667). The same result was observed for risk genotypes (APOE E -/2: SG=7.4%; CG=10.3%, P=0.624). Serum levels of TC, LDLc, and TG revealed similar median values between SG (193.5, 116, and 155 mg/dL, respectively) and CG (207.5, 120, and 123.5 mg/dL, respectively; P >0.05). For HDLc, a higher median value was observed in SG (53.3 mg/dL) versus CG (42.5 mg/dL; P=0.016). Logistic regression analysis showed the same value, and the HDLc/TC ratio was -11.423 (P=0.014), as also confirmed by an increase in HDLc in SG. The association between lipid profiles and apolipoprotein E genotypes was similar in both groups (P>0.05). Conclusion: APOE-HhaI is not associated with AMD. However, an increase in serum HDLc level appears to exert a protective effect against the disease, irrespective of the genetic variants of apoE. .

Objetivo: Este estudo teve como objetivo avaliar a associação de degeneração macular relacionada à idade (DMRI) com variantes de alipoproteína E (APOE) e perfil lipídico sérico, incluindo níveis séricos de colesterol total (TC) e frações de proteínas relacionadas a receptor de LDL (LDLc) e HDL colesterol (HDLc), e triglicérides (TG). Métodos: Realizouse genotipagem de APOE-HhaI em 134 pacientes (grupo de estudo SG) e 164 indivíduos sem a doença (grupo controle CG), na faixa etária entre 5089 anos. O perfil lipídico sérico foi analisado em um subgrupo de 30 indivíduos de ambos os grupos, pareados por idade e sexo. Admitiuse nível de significância para valorP<0,05. Resultados: APOE E3/E3 prevaleceu (SG=74,6%; CG=77,4%), sem diferença entre os grupos (P=0,667), o mesmo ocorreu para genótipos de risco (APOE /E2: SG=7,4%; CG=10,3%,P=0,624).Níveis séricos de TC, LDLc e TG mostraram medianas semelhantes entre SG (193,5; 116; 155 mg/dL, respectivamente) e CG (207,5; 120; 123,5 mg/dL respectivamente; P>0,05). Para HDLc notouse valor de mediana elevado em SG (53,3 mg/dL) versus CG (42,5 mg/dL; P=0,016), constatado também na análise de regressão logística, cuja razão HDLc/TC mostrou coeficiente 11,423 (P=0,014), confirmando acréscimo de HDLc em SG. A relação entre perfil lipídico sérico e genótipos de APOE mostrou semelhança entre os grupos (P>0,05). Conclusão: APOE-HhaI não se associa a DMRI, no entanto, o acréscimo no nível sérico de HDLc parece ter efeito protetor contra a doença, independente de variantes genéticas da apoE. .

Effect of the Wnt/LRP5/β-catenin signaling pathway on the pathogenesis of postmenopausal osteoporosis / 中华妇产科杂志

Objective To investigate the role of the Wnt/LRPS/3-catenin signaling pathway in the pathogenesis of postmenopausal osteoporosis.Methods Fifty female Wistar rats aged 6-month-old,were randomly divided into control group ( NS,n =24 ) and ovariectomized group ( NOVX,n =26),NOVX underwent bilateral ovariectomy.At 0,4 and 8 weeks,all of rats were measured blood estrogen ( E2 ) and bone mineral density (BMD),4 and 8 weeks,low density lipoprotein receptor-related protein 5 (LRP5),3-catenin and Runx2 mRNA in bone were measured respectively by reverse transcription (RT)-PCR.Results In 4 and 8 weeks,compared with NS which had (117±29) and (114+15) pmol/L in E2 level,(0.098 ± 0.016 ) and (0.095 ± 0.028 ) g/cm2 in BMD,NOVX had significantly decreased to ( 92±15 ) and(95±22) pmol/L in E2 level ( P＜0.05 ),( 0.076 ± 0.016) and ( 0.052 ± 0.013 ) g/cm2 in BMD values ( P ＜ 0.01 ).And bone tissue LRP5,β-catenin and Runx2 mRNA expression was 1.02 ± 0.06,1.04 ±0.05,1.07 ±0.21 in NS,NOVX was significantly reduced to 0.97 ± 0.04,0.58 ± 0.05,0.86 ±0.03 (P＜0.05).Conclusion Wnt/LRP5/β-catenin signaling pathway may be important in the pathogenesis of postmenopausal osteoporosis.

Association between Bone Mineral Density and LDL Receptor-Related Protein 5 Gene Polymorphisms in Young Korean Men

Recently, It has been reported that the LDL receptor-related protein 5 (LRP5) regulates bone formation, and that mutations of the gene cause osteoporosis-pseudoglioma syndrome or high bone mass phenotypes. However, the mutations cannot explain a genetic trait for osteoporosis in the general population because of their rarity. From 219 Korean men aged 20-34 yr, we looked for six known polymorphisms causing amino acid changes in the LRP5 coding region, and investigated their association with bone mineral density (BMD) at the following anatomical sites: lumbar spine (L2-L4) and the left proximal femur (femoral neck, Ward's triangle, trochanter and shaft). We found that the Q89R polymorphism was significantly associated with BMD at the femoral neck and Ward's triangle (p=0.004 and <0.001, respectively). However, after adjusting for age, weight and height, a statistically significant association only occurred at the Ward's triangle (p=0.043), and a marginal association was observed at the femoral neck (p=0.098). No A400V, V667M, R1036Q and A1525V polymorphisms were found, and no statistically significant association was found between the A1330V polymorphism and BMD at any sites. Although we failed to demonstrate a clear association between the LRP5 polymorphism and peak bone mass in young men, the present study suggests that larger-scale studies on the Q89R polymorphism need to be performed.

High glucose regulates the expression of connective tissue growth factor and its receptor(low density lipoprotein receptor-related protein) in cultured podocytes / 北京大学学报(医学版)

Objective:To observe the expression of connective tissue growth factor(CTGF) and its receptor-low density lipoprotein receptor-related protein (LRP), and the relevant signaling pathway for the regulation by long-term high glucose exposure in cultured podocytes. Methods:The effects of high glucose on the expression of CTGF and its receptor LRP were analyzed by western blotting. The activation of mitogen activated protein kinase ( MAPKS )signaling pathway by high glucose was also examined. Results: Basal levels of CTGF were observed in cultured mouse podocytes, the levels of CTGF protein were increased by high glucose medium groups on the 2nd day, reached the peak on the 4th day(P0.05).The levels of CTGF expression in normal glucose and mannitol glucose groups did not change markly. High glucose medium induced phosphorylation of ERK_ 1/2 at as early as minute 30, reached the peak at hour 6; maintained the activity at hours 12 and 24, and declined to the basal level at hour 48. However, phosphorylation of ERK_ 1/2 was not detected in normal glucose and mannitol glucose groups. Blockade of phosphorylation of ERK_ 1/2 with PD98059, a specific ERK_ 1/2 activation inhibitior, did decrease the high glucose-triggered expression of CTGF protein in 4 days. High glucose had no effect on the expression of LRP protein at each time point. Conclusion: Acute high glucose (2-4 days)stimulated the expression of CTGF protein via ERK_ 1/2-dependent signaling pathway in cultured podocytes, while cultured in high glucose for 6-8 days, the podocytes did not increase its CTGF level. Long-term high glucose had no effect on the expression of LRP in podocytes.

Expression of connective tissue growth factor and low density lipoprotein receptor related protein induced by transforming growth factor beta 1 in human pulmonary fibroblasts-1 / 北京大学学报(医学版)

Objective: To investigate the tendency and correlation between connective tissue growth factor (CTGF) and low density lipoprotein receptor-related protein (LRP) in human pulmonary fibroblasts-1 (HPF-1) induced by transforming growth factor beta1 (TGF-?_1) at different times. Methods: After the HPF-1 cells were stimulated with TGF-?_1 (5 ?g/L) at different times (0 h, 3 h,6 h,12 h and 24 h),CTGF and LRP mRNA expressions were analyzed by RT-PCR. The same preparation steps of cell culture were repeated, then, the protein expressions were determined by Western Blot, co-immunoprecipitation Western Blot and immunocytochemistry. Results: The expressions of CTGF and LRP mRNA had similar tendency, and LRP (224.87?7.00) correlated with CTGF (131.53?2.86) positively (r= 0.8402, P