Research progress on selective tooth agenesis caused by LRP6 gene mutation / 口腔疾病防治

@#Selective tooth agenesis (STA) is an abnormal number of teeth due to genetic factors or the environment and is most commonly observed for permanent teeth. LRP6 is one of the common causative genes of STA and is inherited by an autosomal dominant mechanism, leading to non-syndrome tooth agenesis (NSTA) or syndrome tooth agenesis (STA). NSTA is only involved in tooth number and appearance abnormalities, whereas STA caused by LRP6 gene mutation results abnormal ear development, oral-facial clefting, sparse hair and hypohidrosis. In this paper, we review the phenotype and gene mutation traits of selective STA caused by LRP6 gene mutation identified in recent years and describe 38 patients with tooth agenesis from 24 mutation sites of LRP6 gene. We analyzed the percentage of missing teeth and found that the lateral incisor in the maxilla and the second premolar in the maxilla and mandible were most commonly lost, whereas all central incisors in the maxilla remained. LRP6 gene plays a major role in tooth development via the WNT/β-catenin signaling pathway, and LRP6 gene mutation can lead to a series of abnormal manifestations due to the disruption of the signaling pathway. The literature showed that LRP6 gene mutations occurred mostly at the E1 or E2 subdomain, meaning that STA due to the mutants extracellularly disturbed the WNT/β-catenin signaling pathway. However, mature treatments for selective congenital tooth loss are lacking.

The role and mechanism of MMP13 and LRP1 in abnormal autophagy function of articular chondrocytes in patients with Kashin-Beck disease / 中华地方病学杂志

Objective:To investigate the impact of matrix metalloproteinase 13 (MMP13) and low-density lipoprotein receptor-related protein 1 (LRP1) on autophagy of articular chondrocytes in patients with Kashin-Beck disease (KBD).Methods:Human articular cartilage samples obtained from 4 KBD patients and 4 control subjects were collected from Shaanxi Institute for Endemic Disease Prevention and Control, and the expression levels of MMP13 and LRP1 in cartilage tissue were determined using immunohistochemistry (IHC). Chondrocytes were extracted and cultured in vitro, the mRNA and protein expression levels of LRP1 and the autophagy related genes [Beclin 1 (BECN1), microtubule associated protein 1 light chain 3 (LC3)], cartilage injury related genes [MMP13, caspase-3 (CASP3)], chondrocyte differentiation related genes [collagen type Ⅱ alpha 1 chain (COL2A1), and SRY-box transcription factor 9 (SOX9)] were detected by real-time fluorescence quantitative PCR (qRT-PCR) and Western blot (WB), respectively. Chondrocytes from 3 KBD patients were extracted, and MMP13 gene silencing experiment was performed by RNA interference (RNAi) technology, the mRNA and protein expression levels of the above genes were detected by qRT-PCR and WB, respectively. In addition, the antagonist receptor associated protein (RAP) of LRP1 was used to block the LRP1 of human normal chondrocytes (C28/I2 cells), and qRT-PCR and WB were used to detect the mRNA and protein expression levels of LRP1, chondrocyte autophagy, differentiation and cartilage injury related genes, respectively. Results:The IHC results showed that the expression levels of MMP13 (1.67 ± 0.21, 0.59 ± 0.15, 0.51 ± 0.12) in the surface, middle, and deep layers of cartilage tissue of KBD patients were significantly higher than those of control subjects (0.25 ± 0.03, 0.26 ± 0.04, 0.06 ± 0.01), and the differences were statistically significant ( t = - 11.38, P < 0.001; t = - 3.82, - 6.26, P = 0.019, 0.003). The expression levels of LRP1 (0.10 ± 0.02, 0.03 ± 0.01, 0.17 ± 0.03) were significantly lower than those of control subjects (1.63 ± 0.40, 0.44 ± 0.12, 0.34 ± 0.08), and the differences were statistically significant ( t = 6.61, 5.61, 3.64, P = 0.003, 0.005, 0.022). The mRNA and protein expression levels of MMP13, CASP3, SOX9 in chondrocytes of KBD patients were significantly higher than those of control subjects, and the differences were statistically significant ( P < 0.05). The mRNA expression levels of LRP1, LC3, COL2A1 were significantly lower than those of control subjects, and the differences were statistically significant ( P < 0.05). After silencing the MMP13 gene in chondrocytes of KBD patients, there were no significant differences in the mRNA and protein expression levels of LRP1, BECN1, LC3, CASP3, COL2A1, and SOX9 ( P > 0.05). After blocking LRP1 with RAP, the protein expression levels of LRP1, BECN1, LC3, MMP13, COL2A1 and SOX9 in chondrocytes were significantly lower than those in control group ( P < 0.05). Conclusions:There is no direct correlation between MMP13 and abnormal autophagy of articular chondrocytes in KBD patients. After blocking LRP1, the expression of the autophagy related genes BECN1 and LC3 in chondrocytes is decreased.

Liuwei Dihuangwan Regulate Brain Microvessels in SAMP8 Mice Through RAGE/LRP1 Receptors / 中国实验方剂学杂志

ObjectiveTo investigate the protective effect of Liuwei Dihuangwan on neurovascular injury in SAMP8 mice. MethodThe Alzheimer's disease （AD） model with insufficiency of kidney essence was induced in 75 SAMP8 mice aging 6 months. The model mice were divided into model group， positive control group （donepezil hydrochloride， 0.747 mg·kg-1·d-1）， and high-， medium-， and low-dose Liuwei Dihuangwan groups （2.700， 1.350， 0.675 g·kg-1·d-1）， with 15 mice in each group. Fifteen SAMR1 mice were assigned to a normal control group. All mice were administered continuously for 2 months. The spatial memory of mice was tested by the Morris water maze. Hematoxylin-eosin （HE） staining was used to observe the pathological changes in the hippocampus and cortex of brain tissues. The immunohistochemical method （IHC） was used to detect the deposition of amyloid β-protein （Aβ） and the expression of von Willebrand factor （vWF） and CD34 in the hippocampus and cortex of brain tissues. Electron microscopy was used to observe the ultrastructural changes in cerebral microvessels. Western blot was used to detect the protein expression levels of the receptor of advanced glycation endproduct （RAGE）， low-density lipoprotein receptor-related protein 1 （LRP1）， vascular endothelial growth factor A （VEGF-A）， and P-selection in the hippocampus and cortex of brain tissues. ResultCompared with the normal control group， the model group showed prolonged escape latency and swimming distance （P<0.01）， increased number of glial cells， decreased number of nerve cells， blurred tight junctions or enlarged gap of the brain microvascular endothelial cells， severely injured membrane structure， swollen mitochondria of endothelial cells， ruptured membrane， massive dissolution in cristae， increased protein expression of Aβ and vWF in the hippocampus and cortex （P<0.01）， reduced protein expression of CD34 （P<0.05）， elevated protein expression of RAGE and P-selection in the cortex （P<0.01）， and decreased protein expression level of LRP1 and VEGF-A （P<0.01）. Compared with the model group， the Liuwei Dihuangwan groups showed shortened escape latency and swimming distance （P<0.05）， reduced number of glial cells in the cortex and hippocampus， increased number of microvessels in the cortex， clear double-layer membrane structure in tight junctions between the microvascular endothelial cells， increased number of mitochondria with intact membrane and recovered mitochondrial cristae， decreased protein expression of Aβ， vWF， RAGE， and P-selection in the hippocampus and cortex （P<0.05）， and increased protein expression of CD34， LRP1， and VEGF-A （P<0.05）. ConclusionLiuwei Dihuangwan can regulate Aβ metabolism through the RAGE/LRP1 receptor system and promote cerebral microvascular angiogenesis by inhibiting vWF expression and increasing VEGF-A and CD34， thereby improving cerebral microvascular injury in SAMP8 mice.

Time dependent expression profiling of PTK2B and its relationship with Aβ, Tau and LRP-1 in hippocampus and blood of APPswe/PS1dE9 double-transgenic mouse / 中国应用生理学杂志

Objective: To uncover the time-dependent expression pattern of ptk2b gene and ptk2b-encoded protein, protein tyrosine kinase 2 beta(PTK2B), in the brain tissues of transgenic animal models of Alzheimer's disease (AD) and its relationship with the levels of Aβ1-42, phosphorylation of Tau (p-Tau) and low density lipoprotein receptor-related protein-1(LRP-1) in blood and brain tissues. Methods: In this study, 5-, 10- and 15-month-old APPswe/PS1dE9 double-transgenic mice harboring the genotype of AD confirmed by the gene test were divided into the 5-, 10- and 15-month-old experiment groups, and simultaneously, age-matched C57BL/6J mice were placed into the corresponding control groups, with 8 mice in each group. All mice were subjected to the Morris Water Maze for test of cognitive and behavioral ability. Expression profiles of PTK2B, Aβ1-42, p-Tau/Tau and LRP-1 in the hippocampus or blood of mice were quantified by using the immunohistochemistry staining, Western blot or enzyme-linked immunosorbent assay (ELISA), while the mRNA expression of ptk2b in the hippocampus was quantified by using the real-time quantitative polymerase chain reaction (qRT-PCR). Results: Results of experiment groups demonstrated that as mice aged, the expression levels of PTK2B, ptk2b mRNA, Aβ1-42 and p-Tau/Tau in the hippocampus were increased, and the expression of LRP-1 was decreased gradually. While in the blood, the level of Aβ1-42 was decreased, and the cognitive and behavioral ability was decreased in an age-dependent manner (all P＜ 0.05). However, comparisons among the control groups, only the age-dependent downregulation of LRP-1 were observed in hippocampus(P＜0.05), but other indicators had no significant differences (P＞0.05). Conclusion: In the hippocampus of APP/PS1 double-transgenic mice, the expressions of PTK2B, Aβ1-42 and p-Tau/Tau are upregulated, LRP-1 is downregulated, while cognitive and behavioral ability is decreased, and such changes are presented in a time-dependent manner.

Relationship between Discordance of Low-Density Lipoprotein and Non-High-Density Lipoprotein Cholesterol and Risk Stratification in Acute Myocardial Infarction

Abstract Background: Sizeable proportion of patients have discordant low-density lipoprotein cholesterol (LDL-C) and non-high density lipoprotein cholesterol (NHDL-C). It has been shown that discordance of LDL-C and NHDL-C either underestimates or overestimates coronary risk. Objectıve: We assessed whether this discordance has an impact on GRACE and TIMI risk scores in patients with acute myocardial infarction (AMI). Methods: We retrospectively evaluated the data of 198 consecutive patients with AMI. Fasting serum lipid profiles were recorded, GRACE and TIMI scores were calculated. Patients were divided into 3 groups according to LDL-C and NHDL-C percentiles: Discordant group: LDL-C<NHDL-C (n=38), concordant group: LDL-C=NHDL-C (n=112) and discordant group LDL-C>NHDL-C (n=48). GRACE and TIMI scores, mortality and cardiovascular events (heart failure, non-fatal myocardial infarction and angina) at sixth month were compared between these three groups. Differences between these groups were analyzed with One-way ANOVA or Kruskal-Wallis rank test, and with chi-square for percentages. Also, post hoc LSD or Conover-Iman's non-parametric multiple comparison test were used. A p value <0.05 was accepted as statistically significant. Results: TIMI risk score didn't differ between discordant or concordant groups. Mean GRACE (death) and GRACE (death and MI) scores were higher in group with LDL-C<NHDL-C than with LDL-C=NHDL-C and LDL-C>NHDL-C (p=0.029 and 0.008, respectively). Cardiovascular events and mortality at sixth month were not different among groups (p=0.473 and p=0.176, respectively). Conclusion: GRACE score was higher in discordant group with LDL-C<NHDL-C, but there is no difference regarding TIMI scores between discordant and concordant groups in AMI patients.

Effect of Zuoguiwan on Wnt/β-catenin Signaling Pathway in Ovariectomized Osteoporosis Model Rats / 中国实验方剂学杂志

Objective:To observe the effect of Zuoguiwan on bone metabolism and Wnt/<italic>β</italic>-catenin signaling pathway in ovariectomized osteoporotic rats model， and to explore the molecular biological mechanism of Zuoguiwan in the prevention and treatment of osteoporosis. Method:The rat model of postmenopausal osteoporosis was established by bilateral ovariectomy， 60 female SD rats were randomly divided into sham operation group， model group， positive group （estradiol valerate tablet 0.05 mg·kg^-1·d^-1） and low， middle and high dose groups of Zuoguiwan （5.5，11，22 g·kg^-1·d^-1）.After successful establishment of the model in the 13^th week， intragastric administration （<italic>ig</italic>） was given once a day for a total of 12 weeks. After administration， the histomorphological changes of femur in rats were observed by hematoxylin-eosin （HE） staining， the bone mineral density （BMD） and bone mineral content（BMC） of femur were measured by dual energy X-ray apparatus， and the biomechanical properties of bone were measured by MTS Acumen3 biomechanical testing system. The contents of bone alkaline phosphatase （BALP）， bone glaprotein（BGP），estradiol （E₂） ，and tartrate-resistant acid phosphatase （TRAP）， type Ⅰ procollagen N-terminal propeptide （PINP） in serum were detected by enzyme-linked immunosorbent assay （ELISA）. Western blot was used to detect the protein level of Wnt2，<italic>β</italic>-catenin，low density lipoprotein related receptor protein 5 （LRP5） and the phosphorylation level of glycogen synthase kinase-3<italic>β</italic>（GSK-3<italic>β</italic>） in rat tibia. Result:Compared with sham operation group， the maximum load and stiffness of BMD，BMC， in the model group decreased significantly（<italic>P</italic><0.01）， the contents of E₂ and PINP in serum decreased significantly（<italic>P</italic><0.01）， the content of BALP，BGP，TRAP increased significantly（<italic>P</italic><0.01）， the expression levels of Wnt2，p-GSK-3<italic>β </italic>Ser9，LRP5 and <italic>β</italic>-catenin protein in bone tissue decreased significantly（<italic>P</italic><0.01）， the trabecula of femur became thinner and thinner， the number of bone trabeculae decreased. Compared with model group， the maximum load and stiffness of BMD，BMC， in estradiol group and Zuoguiwan group were significantly increased （<italic>P</italic><0.05，<italic>P</italic><0.01）， the contents of serum E₂ and PINP were significantly increased （<italic>P</italic><0.05，<italic>P</italic><0.01）， the content of BALP，BGP，TRAP was significantly decreased （<italic>P</italic><0.01）， and the expression level of Wnt2，p-GSK-3<italic>β</italic> Ser9，LRP5， <italic>β</italic>-catenin protein in bone tissue was significantly increased （<italic>P</italic><0.05，<italic>P</italic><0.01） ， the trabeculae of femur became thicker， the number increased， the structure was basically clear. Conclusion:Zuoguiwan has a certain preventive and therapeutic effect on osteoporosis in ovariectomized rats， and its mechanism may be related to increasing the level of estrogen， activating Wnt/<italic>β</italic>-catenin signaling pathway， up-regulating the expression of Wnt2 and LRP5 protein， inhibiting the activity of GSK-3<italic>β</italic>， reducing the degradation of <italic>β</italic>-catenin， coordinating the dynamic coupling balance between bone formation and bone resorption， correcting the disorder of bone metabolism and improving bone morphology.

Role of the LRP1-pPyk2-MMP9 pathway in hyperoxia-induced lung injury in neonatal rats / 中国当代儿科杂志

OBJECTIVES@#To study the role of the low-density lipoprotein receptor-related protein 1 (LRP1)-proline-rich tyrosine kinase 2 phosphorylation (pPyk2)-matrix metalloproteinases 9 (MMP9) pathway in hyperoxia-induced lung injury in neonatal rats.@*METHODS@#A total of 16 neonatal rats were randomly placed in chambers containing room air (air group) or 95% medical oxygen (hyperoxia group) immediately after birth, with 8 rats in each group. All of the rats were sacrificed on day 8 of life. Hematoxylin and eosin staining was used to observe the pathological changes of lung tissue. ELISA was used to measure the levels of soluble LRP1 (sLRP1) and MMP9 in serum and bronchoalveolar lavage fluid (BALF). Western blot was used to measure the protein expression levels of LRP1, MMP9, Pyk2, and pPyk2 in lung tissue. RT-PCR was used to measure the mRNA expression levels of LRP1 and MMP9 in lung tissue.@*RESULTS@#The hyperoxia group had significantly higher levels of sLRP1 and MMP9 in serum and BALF than the air group (@*CONCLUSIONS@#The activation of the LRP1-pPyk2-MMP9 pathway is enhanced in hyperoxia-induced lung injury in neonatal rats, which may be involved in the pathogenesis of bronchopulmonary dysplasia.

Effect of Sijunzi Decoction on regulation of Aβ-related proteins across blood-brain barrier / 中国中药杂志

According to traditional Chinese medicine, "spleen transport" is closely related to the metabolism of substance and energy. Studies have shown that Alzheimer's disease(AD) is a disease related to glucose and lipid metabolism and energy metabolism. The traditional Chinese medicine Jiangpi Recipe can improve the learning ability and memory of AD animal model. Sijunzi Decoction originated from Taiping Huimin Hefang Prescription is the basic prescription for strengthening and nourishing the spleen, with the effects of nourishing Qi and strengthening the spleen. In this experiment, human brain microvascular endothelial cells(HBMEC) and Sijunzi Decoction water extract(0.25, 0.5, 1 mg·L~(-1)) were pre-incubated for 2 h, and then Aβ_(25-35) oligomers(final concentration 40 μmol·L~(-1)) was added for co-culture for 22 hours. The effect of Sijunzi Decoction on the activity of Aβ_(25-35) oligomer injured cells and the expression of related proteins were investigated. Q-TOF-LC-MS was used first for principal component analysis of Sijunzi Decoction water extract. Then MTT assay was used to investigate the effect of Sijunzi Decoction water extract on the proliferation of HBMEC cells. Real-time fluorescence quantitative PCR(RT-qPCR) was employed to detect the mRNA expression of GLUT1, RAGE, and LRP1. The expression of Aβ-related proteins across blood-brain barrier(RAGE, LRP1) was detected by Western blot. The results showed that 40 μmol·L~(-1) Aβ_(25-35) oligomers could induce endothelial cell damage, reduce cell survival, increase expression of RAGE mRNA and RAGE protein, and reduce expression of GLUT1 mRNA, LRP1 mRNA, and LRP1 protein. Sijunzi Decoction water extract could reduce the Aβ_(25-35) oligomer-induced cytotoxicity of HBMEC, decrease the expression of RAGE mRNA and RAGE protein, and increase the expression of GLUT1 mRNA, LRP1 mRNA and LRP1 protein. The results indicated that Sijunzi Decoction could reduce the injury of HBMEC cells induced by Aβ_(25-35) oligomer, and regulate the transport-related proteins GLUT1, RAGE and LRP1, which might be the mechanism of regulating Aβ_(25-35) transport across the blood-brain barrier.

One family with osteosclerosis caused by D111Y mutation in the low-density lipoprotein receptor-related protein 5 gene / 中华内分泌代谢杂志

Objective@#To investigate the clinical features and pathogenic genes of a family with osteosclerosis.@*Methods@#Six patients and six family members from a family in Jiangsu were tested for biochemical parameters, bone metabolic markers, bone mineral density, thoracolumbar anterior lateral slices, skull positive lateral radiographs, and pelvic plain films. Meanwhile, Sanger sequencing was performed to detect gene mutations of the proband and five other family members with high bone mass. The conformation of the mutational low-density lipoprotein receptor-related protein 5 (LRP5) protein was predicted by SWISS-MODEL.@*Results@#Four adult patients (one male and three females) were tall, with mandibular enlargement and kyphosis in the center of the lower jaw, and none of the four had fractures. Their X ray examination revealed that the skull and long bone cortex was thickened, while the sella and mandible was enlarged. In addition, the absolute values of bone mineral density at each site of all patients were significantly higher as compared with the standard age- and sex-matched adults or adolescent mean reference values, with Z scores of L2-4, femoral neck and total hip being (6.31±4.03) SD, (6.56±2.36) SD, and (7.19±2.03) SD, respectively. The results of genetic sequencing revealed that all six patients carried a heterozygous mutation (c.331G>T; D111Y) in exon 2 of LRP5 gene, while other family members showed wild type (c.331G>G; D111D). Functional prediction indicated that this mutation was located at the amino acid terminal of exon 2 of LRP5 gene, which encodes the first β-helix-generating region of LRP5 protein.@*Conclusion@#The D111Y mutation in LRP5 gene leads to a clinical phenotype characterized by benign increased bone mineral density without increasing the risk of fracture. This mutation may further affect the downstream Wnt signaling pathway by altering the spatial structure of LRP5 protein, thereby promoting maturation and differentiation of osteoblasts and resulting in osteosclerosis.

Effect of Zhenxin Shengshui Yizhi Fang on Damage of Human Brain Microvascular Endothelial Cells Induced by Aβ25-35 / 中国实验方剂学杂志

Objective::To observe the neuroprotective effect and potential mechanism of Zhenxin Shengshui Yizhi Fang(XSF) aqueous extract on human brain microvascular endothelial cells (HBMEC) injury induced by amyloid-β protein(Aβ)25-35. Method::HBMEC cells damage induced by Aβ25-35 was used as Alzheimer' s disease(AD) cell model. The study included control group, Aβ25-35 group, and low, medium and high-dose XSF aqueous extract groups (125, 250, 500 mg·L-1). After treatment, the cytotoxicity of different concentrations of drugs and Aβ25-35 was determined by methyl thiazolyl tetrazolium(MTT) colorimetry. Apoptosis was observed by Hoechst-33258 staining. The activity of Caspase-3 was detected by colorimetry. Western blot was used to detect the expression levels of the receptor of advanced glycation end products (RAGE) and low-density lipoprotein receptor-related protein (LRP1). Result::Compared with the control group, the cell viability of Aβ25-35 group was significantly decreased (P<0.01). Hoechst-33258 staining showed bright blue fluorescence, chromatin condensation, dense staining or fragmentation dense staining, whitening in color, and significant increase of the percentage of apoptotic cells (P<0.01). Caspase-3 activity increased significantly (P<0.01). Western blot showed that RAGE protein expression increased significantly (P<0.01), while low-density lipoprotein receptor-related protein(LRP1), glucose transporter 1(GLUT1) and GLUT3 protein expressions decreased significantly (P<0.01). Compared with the Aβ25-35 group, the cell viability of XSF aqueous extract groups was significantly increased in a dose-dependent manner. The XSF aqueous extract had a more significant protective effect of than the other groups (P<0.05). The XSF aqueous extract group (500 mg·L-1) significantly inhibited the number of apoptotic cells (P<0.01), but significantly reduced the Caspase-3 activity (P<0.01). RAGE protein expression was not significantly decreased in XSF aqueous extract group (125 mg·L-1), but significantly decreased in XSF aqueous extract group (250, 500 mg·L-1, P<0.01), while LRP1, GLUT1 and GLUT3 protein expression significantly increased (P<0.05, P<0.01) in a dose-dependent manner. Conclusion::XSF aqueous extract can attenuate the cytotoxicity of HBMEC induced by Aβ25-35 oligomer, inhibit apoptosis, decrease caspase-3 activity and RAGE protein expression, increase LRP1, GLUT1 and GLUT3 protein expressions, and reduce the abnormal accumulation and deposition of Aβ in the brain, which may be its mechanisms for prevention and treatment of AD.

The relationship of MEOX2 and neurovascular dysfunction in Alzheimer's disease model / 药学学报

Present study investigated the role of mesenchyme homeobox 2 (MEOX2) gene in neurovascular dysfunction in Alzheimer's disease (AD) model rats by bilateral intracerebroventricular injection of Aβ1-42. One week after surgery, Morris water maze, immunohistochemistry, biochemical detection, Western blot and real-time PCR were used to detect the indexes. The animal studies were conducted in accordance with the Regulations of Experimental Animal Administration issued by the State Committee of Science and Technology of the People's Republic of China. Compared to the Sham-operated rats, Aβ1-42-operated rats showed obviously cognitive dysfunction, accompanied by increased Aβ, glial fibrillary acidic protein (GFAP), allograft inflammatory factor 1 (AIF1), endothelial nitric oxide synthase (eNOS) and decreased neuron specific enolase (NSE), synaptophysin (SYN), CD34, vascular endothelial growth factor (VEGF) expressions of brain. Aβ1-42-operated rats also increased the endothelin (ET) level and decreased nitric oxide (NO) level in brain tissue. Moreover, MEOX2 expression was decreased correlated with low density lipoprotein receptor-related protein 1 (LRP-1) decreasing and receptor for advanced glycation end products (RAGE) increasing in brain tissues of AD model rats. We found the correlation between MEOX2 gene expression and neurovascular dysfunction, in addition, the decreased MEOX2 may involve in increasing the accumulation of Aβ in brain by relating to the decreased LRP-1 and increased RAGE which is located in blood-brain barrier (BBB) in senescence-accelerated mice.

Research progress on transport mechanism of amyloid beta-peptides across blood-brain barrier / 中国药理学通报

Amyloid beta-peptides ( Aβ) is the key pathological feature of Alzheimer’s Disease (AD). Various factors contrib-ute to the accumulations of Aβ in the brains of patients. Among them, blood-brain barrier ( BBB) plays a crucial role in trans-porting Aβ between the brain and the bloodstream while this transfer function is mediated by the receptor of Aβon BBB. The abnormality of Aβ transport and related receptor expression can be detected in the brains of patients with AD, resulting in an un-usual increase in Aβlevels unusually increased . This review e-laborates the structure and function of BBB, the transport of Aβand the expression and transport mechanism of the related recep-tor, as well as summarizes the possible clearance strategy of Aβacross the BBB.

Association between Low-density Lipoprotein Receptor-related Protein 5 Polymorphisms and Type 2 Diabetes Mellitus in Han Chinese: a Case-control Study / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the association between low-density lipoprotein receptor-related protein 5 (LRP5) variants (rs12363572 and rs4930588) and type 2 diabetes mellitus (T2DM) in Han Chinese.</p><p><b>METHODS</b>A total of 1842 T2DM cases (507 newly diagnosed cases and 1335 previously diagnosed cases) and 7777 controls were included in this case-control study. PCR-RFLP was conducted to detect the genotype of the two single nucleotide polymorphisms (SNPs). Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to describe the strength of the association by logistic regression.</p><p><b>RESULTS</b>In the study subjects, neither rs12363572 nor rs4930588 was significantly associated with T2DM, even after adjusting for relevant covariates. When stratified by body mass index (BMI), the two SNPs were also not associated with T2DM. Among the 3 common haplotypes, only haplotype TT was associated with reduced risk of T2DM (OR 0.820, 95% CI 0.732-0.919). In addition, rs12363572 was associated with BMI (P<0.001) and rs4930588 was associated with triglyceride levels (P=0.043) in 507 newly diagnosed T2DM cases but not in healthy controls.</p><p><b>CONCLUSION</b>No LRP5 variant was found to be associated with T2DM in Han Chinese, but haplotype TT was found to be associated with T2DM.</p>

The lipid-lowering effect and possible mechanism of apobec-1 in nephrotic syndrome rabbits / 中华实用儿科临床杂志

Objective To observe the effect of liver acquired expression of apobec-1 on blood lipid metabolism, hepatic low density lipoprotein receptor (LDLR), and hepatic low density lipoprotein receptor related protein (LRP) in nephrotic syndrome(NS) rabbits and to explore the lipid-lowering effect and possible mechanism.Methods Thirty healthy ordinary level male new Zealand rabbits were randomly divided into 3 groups:sham operation group (n =10), N S group (n =10), and apobec-1 treatment group (n =10).Adaptive feeding was given for 1 week, then NS group and apobec-1 treatment group underwent left nephrectomy,and 1 week later,adriamycin (4 mg/kg) was used to construct the NS model by way of ear vein injection.In the 11th week after operation, apobec-1 recombinant adenovirus (1 × 1013 virus/kg) was injected through ear vein in apobec-1 treatment group.The 12th week after operation, all rabbits were sacrificed.Right kidney, liver, blood and 24 hour urine were collected.In 3 groups, 24 hour urinary protein (24UPr), albumin (Alb), blood urea nitrogen (BUN), creatinine (Cr), blood lipid were detected.Renal pathology was observed by means of HE staining.Expressions of liver LDLR, LRP were observed by using Western blot.Results (1) There were significant differences among the 3 groups in 24UPr (F =42.778, P =0.000), Alb (F =3.819, P =0.034), BUN (F =6.562, P =0.005), Cr (F =16.076, P =0.000), total cholesterol (TC) (F =17.531, P =0.000), total triglyceride (TG) (F =6.192, P =0.006), very low density lipoprotein (VLDL-C) (F =6.192, P =0.006), low density lipoprotein (LDL-C) (F =34.924, P =0.000) and apolipoprotein B100 (ApoB100) (F =5.180, P =0.012) and apolipoprotein B48 (ApoB48) (F =6.161, P =0.006).(2) Compared with the sham operation group, NS group showed that 24UPr, BUN, Cr, TC, TG, VLDL-C, LDL-C, ApoB100 increased, but Alb decreased, and there was statistical significance (all P ＜ 0.05).(3) Compared with NS group, apobec-1 treatment group showed that TC, TG, VLDL-C, LDL-C, ApoB 100, ApoB48 decreased, and there were statistical significances (all P ＜ 0.05).(4) Compared with the sham operation group, apobec-1 treatment group showed that 24UPr, BUN, Cr increased, but Alb, apolipoprotein B48 (ApoB48) decreased, there were statistical significances (all P ＜ 0.05).(5) There were significant differences of hepatic protein expression among the 3 groups in LRP (F =44.180, P =0.000), LDLR (F =63.141 ,P =0.000).Compared with the sham operation group and NS group, apobec-1 treatment group showed that the expression of LRP was up-regulated (P ＜ 0.01,0.05), while the expression of LDLR was down-regulated (all P ＜ 0.05).Conclusions When liver acquired expression of apobec-1 in NS, it could up-regulate LRP,accelerate the elimination of ApoB48-lipoproteins, and produce a certain lipid-lowering effect.

The intervention study of atorvastatin on the effect of proliferation and differentiation and the expression of low density lipoprotein receptor-related protein 5, dickkopf-1 mRNA of osteoblasts caused by low density lipoprotein / 中华内分泌代谢杂志

Objective The aim of this study was to explore the effect of low density lipoprotein ( LDL) on the proliferation and differentiation of MC3T3-E1 osteoblasts, as well as the expression of low density lipoprotein receptor-related protein 5(LRP5) and dickkopf-1(DKK1) mRNA of MC3T3-E1 osteoblasts. The possible mechanisms of the treatment of atorvastatin on LDL expression in MC3T3-E1 osteoblasts were also investigated. Methods Proliferation, osteocalcin expression, LRP5, and expression of DKK1 mRNA of MC3T3-E1 with interaction of LDL at 0. 05, 0. 10, 0. 20 mg/ml levels after 24 h, 48 h, 72 h were detected by CCK8, ELISA, and fluorescence quantitative PCR. Furthermore, proliferation, osteocalcin expression, LRP5 and DKK1 mRNA of MC3T3-E1 after the treatment of atorvastatin of 10-6 mol/L and 10-5 mol/L were also be studied, respectively. Results The effect of LDL on proliferation, expression of osteocalcin and expression of LRP5 and DKK1 mRNA in MC3T3-E1 osteoblasts was the most obvious under LDL with 0. 20 mg/ml level. Under that level, atorvastatin (10-6 mol/L or 10-5 mol/L) was able to make the proliferation of MC3T3-E1 osteoblasts in 48 h and 72 h be decreased, while significantly caused upregulation of osteocalcin, LRP5 mRNA expression; and down regulated DKK1 mRNA expression ( all P<0. 05). Conclusions Atorvastatin can reduce the inhibitory effect of LDL on the proliferation and differentiation of osteoblasts. The mechanisms of atorvastatin on osteoblasts are possibly related to the osteoblast proliferation and expression of LRP5 mRNA and DKK1 mRNA of osteoblasts of wnt signal pathway.

Advances in LRP-1-regulated vascular integrity / 中国病理生理杂志

Low-density lipoprotein receptor-related protein-1 (LRP-1) is a transmembrane receptor protein locatedon the plasma membrane of the cells and involved in receptor-mediated endocytosis.LRP-1 binds to distinct ligandsthat are structurally and functionally unrelated, which makes it not only mediates endocytosis, but also regulates cell surfaceproteolytic activity and specific intracellular signaling pathways related to multiple links in the process of developmentof atherosclerosis.Moreover, LRP-1 plays an important role in maintaining vascular stability.This review focuses on theprogress in LRP-1-regulated vascular integrity, and provides new insights to the target of the blood vessel diseases.

Relationship between Physico-chemical Parameters and Phylogenetics Study of Human Low Density Lipoprotein Receptor-Related Protein (LRP).

In this study, 11members of human low density lipoprotein receptor-related protein (LRP) sequences was retrieved from UniProtKB/ SWISS-PROT protein database and was analyzed for information about their structural, functional and phylogenetic features. This was achieved by using many established biocomputational tools which was available at their latest version. This study shows that LRP 12 and 3 are closely related with LRP8 being their nearest neighbor. In all, it was observed that there were very low possession of certain essential amino acid like glycine, proline and a very high aliphatic in all the LRP family. Considering the evolutionary history, functional domains, high aliphatic index, overall proportion of glycine and proline and the established role of one (LRP8) of this closely related LRP in diseases, it is thus predicted that the other closely related LRP3 and 12 molecules may be important candidate in investigating the aetiopathology of Myocardial infarction1diseases or other heart related disorder.

Effects of glycated low density lipoprotein on the proliferation and differentiation and expression of low-density lipoprotein receptor-related protein-5 mRNA, dickkopf-1 mRNA in mouse osteoblasts / 中华内分泌代谢杂志

Objective The aim of this study was to investigate the possible effect of glycated low density lipoprotein ( LDL ) on the proliferation, differentiation, and expression of low-density lipoprotein receptor-related protein5(LRP5)mRNA,dickkopf-1(DKK1)mRNAinmouseosteoblasts(MC3T3-E1cells). WhethertheWnt signaling pathway was involved in the above process was explored else. Methods Mouse MC3T3-E1 cells were culturedwithvariousconcentrationsofglycatedLDL(glycatedLDLlevelwas2.4%,5.3%,8.7%,13.9%)for24, 48, 72 h. Proliferation of MC3T3-E1 cell was measured by CCK-8, the osteocalcin level in the medium was determined by ELISA and the expression of LRP5 mRNA, DKK1 mRNA was measured by realtime PCR. Results After cells being incubated with 5. 3% of glycated LDL for 24 h, the inhibition of MC3T3-E1 cells was more marked than that in control group(P<0. 01). The higher glycated LDL level, the severer the inhibition. The effect of LDL on the MC3T3-E1 cell proliferation was time- and dose-dependent under certain conditions. Osteocalcin level in cell culture fluid with glycated LDL was lowered significantly compared with control group. Meanwhile, the expression of DKK1 mRNA was increased significantly but expression of LRP5 mRNA decreased (P<0. 01) in MC3T3-E1 cells cultured with 5. 3% of glycated LDL for 24 h. Conclusions Proliferation and differentiation of the osteoblasts in mice can be inhibited significantly by glycated LDL. The possible mechanism in the role played by glycated LDL on the proliferation and differentiation in MC3T3-E1 cells seems to be related to expression of LRP5 mRNA, DKK1 mRNA in the Wnt signaling pathway.

Role of vitamin D-binding protein in isocyanate-induced occupational asthma

The development of a serological marker for early diagnosis of isocyanate-induced occupational asthma (isocyanate-OA) may improve clinical outcome. Our previous proteomic study found that expression of vitamin D-binding protein (VDBP) was upregulated in the patients with isocyanate-OA. In the present study, we evaluated the clinical relevance of VDBP as a serological marker in screening for isocyanate-OA among exposed workers and its role in the pathogenesis of isocyanate-OA. Three study groups including 61 patients with isocyanate-OA (group I), 180 asymptomatic exposed controls (AECs, group II), 58 unexposed healthy controls (NCs, group III) were enrolled in this study. The baseline serum VDBP level was significantly higher in group I compared with groups II and III. The sensitivity and specificity for predicting the phenotype of isocyanate-OA with VDBP were 69% and 81%, respectively. The group I subjects with high VDBP (> or = 311 microg/ml) had significantly lower PC20 methacholine levels than did subjects with low VDBP. The in vitro studies showed that TDI suppressed the uptake of VDBP into RLE-6TN cells, which was mediated by the downregulation of megalin, an endocytic receptor of the 25-hydroxycholecalciferol-VDBP complex. Furthermore, toluene diisocyanate (TDI) increased VEGF production and secretion from this epithelial cells by suppression of 1,25-dihydroxycholecalciferol [1,25(OH)2D3] production. The findings of this study suggest that the serum VDBP level may be used as a serological marker for the detection of isocyanate-OA among workers exposed to isocyanate. The TDI-induced VEGF production/secretion was reversed by 1,25(OH)2D3 treatment, which may provide a potential therapeutic strategy for patients with isocyanate-OA.

Regulation of ? amyloid protein level in the brain / 中国临床药理学与治疗学

? amyloid protein(A?) including A?40 and A?42 are the important bioactive substances in vivo.Their toxic and beneficial attributes in the body depend on its concentration.The brain A? level is maintained by two balances under the physiological condition.The first balance is the generation involved in ?-secretase and ?-secretase and the degradation involved in neprilysin(NEP) and insulin-degrading enzyme(IDE) of A?. The second one is the balance between the receptor for advanced end glycation products(RAGE)-mediated influx and low-density lipoprotein receptor related protein 1(LRP1)-mediated efflux of A? across the blood-brain barrier(BBB).Breakdowning any one of the two balances would result in the aggregation and precipitation of A? in the brain,which is a crucial event in the pathogenesis of Alzheimer's disease(AD).This paper reviews the regulation of brain A? level under the physiological condition and the reducing strategies on the level of brain A? under the pathological condition for developing new drugs in the treatment of AD.