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Aim To explore the protective mechanism of tanshinone B on cognitive dysfunction in mice with vascular dementia.Methods C57BL/6 male mice were divided into control group, vascular dementia model group(VD group), tanshinone B group(TSB 2,4,8 mg·kg-1), donepezil hydrochloride group(1 mg·kg-1), according to the random number table method.The VD model was constructed by the coarctation of bilateral common carotid arteries in mice.Ten days after the successful modeling, the low, medium, and high-dose tanshinone B groups were intraperitoneally injected with tanshinone B, the positive control medicine group was intraperitoneally injected with donepezil hydrochloride, once a day, and the mice in control group and VD group were injected intraperitoneally with the same amount of normal saline for 20 d.Morris water maze test was used to detect the learning and memory ability of mice in each group; the cortex and hippocampus of each group were separated, and MDA, SOD and GSH-Px were determined by spectrophotometry; the pathological changes in the hippocampus of each group were observed by HE staining.The expression of p-LRP6, LRP6, Wnt1 and β-catenin protein in the hippocampus of each group of mice were detected by Western blot.Results Compared with control group, the ability of memory was reduced, the content MDA increased(P<0.01), SOD and GSH-Px activities decreased(P<0.01), and significant pathological damage in hippocampus, the expression of p-LRP6, Wnt1, and β-catenin protein was significantly reduced in VD group(P<0.01).Compared with VD group, the learning and memory abilities of the mice were improved, the content of MDA decreased(P<0.01), the activities of SOD and GSH-Px increased(P<0.01), and the pathological damage in hippocampus was significantly improved.The expression of Wnt1 and β-catenin protein increased significantly in TSB treatment group(P<0.01).Conclusions TSB can improve the cognitive dysfunction of VD mice, and its mechanism may be related to the activation of the LRP6/Wnt1/β-catenin pathway in hippocampus.
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Neuronal apoptosis is one of the essential mechanisms of early brain injury after subarachnoid hemorrhage (SAH). Recently, HLY78 has been shown to inhibit apoptosis in tumor cells and embryonic cells caused by carbon ion radiation through activation of the Wnt/β-catenin pathway. This study was designed to explore the anti-apoptotic role of HLY78 in experimental SAH. The results demonstrated that HLY78 attenuated neuronal apoptosis and the neurological deficits after SAH through the activation of low-density lipoprotein receptor-related protein 6 (LRP6), which subsequently increased the level of phosphorylated glycogen synthesis kinase 3 beta (p-GSK3β) (Ser9), β-catenin, and Bcl-2, accompanied by a decrease of p-β-catenin, Bax, and cleaved caspase 3. An LRP6 small-interfering ribonucleic acid reversed the effects of HLY78. In conclusion, HLY78 attenuates neuronal apoptosis and improves neurological deficits through the LRP6/GSK3β/β-catenin signaling pathway after SAH in rats. HLY78 is a promising therapeutic agent to attenuate early brain injury after SAH.
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Neuronal apoptosis is one of the essential mechanisms of early brain injury after subarachnoid hemorrhage (SAH). Recently, HLY78 has been shown to inhibit apoptosis in tumor cells and embryonic cells caused by carbon ion radiation through activation of the Wnt/β-catenin pathway. This study was designed to explore the anti-apoptotic role of HLY78 in experimental SAH. The results demonstrated that HLY78 attenuated neuronal apoptosis and the neurological deficits after SAH through the activation of low-density lipoprotein receptor-related protein 6 (LRP6), which subsequently increased the level of phosphorylated glycogen synthesis kinase 3 beta (p-GSK3β) (Ser9), β-catenin, and Bcl-2, accompanied by a decrease of p-β-catenin, Bax, and cleaved caspase 3. An LRP6 small-interfering ribonucleic acid reversed the effects of HLY78. In conclusion, HLY78 attenuates neuronal apoptosis and improves neurological deficits through the LRP6/GSK3β/β-catenin signaling pathway after SAH in rats. HLY78 is a promising therapeutic agent to attenuate early brain injury after SAH.
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@#【Objective】To investigate the function of LRP6 and canonical Wnt/β-catenin signaling pathway in Doxorubicin-induced cardiomyopathy.【Methods】To establish the model of Dox cardiomyopathy in vitro and in vivo，H9C2 cells were treated with Dox（1 μmol/L）for 12 h and twelve SD rats were divided into two groups equally，and intraperitoneally injected with normal saline and Dox respectively. The changes of protein and mRNA levels were detected by western blot and qPCR. Cardiomyocytes were transfected with siRNA to knockdown LRP6. Mitochondrial membrane potential，nuclear condensation and matrix swelling were determined by Rhodamine 123 ，Hoechst and Mitotracker staining respectively. The apoptosis rate of cells was measured by flow cytometric analysis. 【Results】 The model of Dox cardiomyopathy was successfully established in vitro and in vivo. Dox downregulated the mRNA and protein levels of LRP6. Knockdown of LRP6 aggravated the cell apoptosis and mitochondrial damage induced by Dox. Both Dox and silencing LRP6 induced the downregulation of β - catenin ，and activation of β - catenin reversed the cardiomyocytes apoptosis caused by Dox. 【Conclusions】 Dox downregulated the expression of LRP6 and inhibited canonical Wnt/β- catenin signaling pathway，thus causing cardiomyocytes apoptosis and mitochondrial dysfunction.
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Metabolic syndrome is the fundamental factor in the pathogenesis of a variety of diseases, and it has not yet been fully understood due to its complicated mechanism. Multiple re-searches have implicated that Wnt/β-catenin signaling pathway may have a significant effect on the formation and development of metabolic syndrome. LRP6 is an important co-receptor of Wnt/β-catenin signaling pathway ,and there are some researches im-plicating the correlation between LRP6 and metabolic syndrome. The in-depth research on the gene polymorphism and its modula-tion mechanism can provide new ideas and directions for meta-bolic syndrome therapy.
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Androgen receptor (AR) signaling is important for prostate cancer (PCa) cell proliferation. Here, we showed that proliferation of hormone-sensitive prostate cancer cells such as LNCaP was significantly enhanced by testosterone stimulation whereas hormone-insensitive prostate cancer cells such as PC3 and VCaP did not respond to testosterone stimulation. Blocking of AR using bicalutamide abolished testosterone-induced proliferation of LNCaP cells. In addition, knockdown of AR blocked testosterone-induced proliferation of LNCaP cells. Basal expression of low-density lipoprotein receptor-related protein 6 (LRP6) was elevated in VCaP cells whereas stimulation of testosterone did not affect the expression of LRP6. However, expression of LRP6 in LNCaP cells was increased by testosterone stimulation. In addition, knockdown of LRP6 abrogated testosterone-induced proliferation of LNCaP cells. Given these results, we suggest that androgen-dependent expression of LRP6 plays a crucial role in hormone-sensitive prostate cancer cell proliferation.
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Proliferação de Células , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade , Neoplasias da Próstata , Receptores Androgênicos , TestosteronaRESUMO
Epstein-Barr virus (EBV)-encoded small non-coding RNAs (EBERs) are abundantly expressed in various EBV-associated malignancies, and play critical roles in cell proliferation, tumorigenesis, and apoptosis resistance. However, the mechanism how EBERs regulate cell function awaits further clarification. In this study, we investigated the effect of EBERs on the expression of cellular microRNA (miRNA) and mRNA expression. To test the effect of EBERs while unaffected by other EBV genes, we used EBERs-deleted recombinant EBV infected Burkitt's lymphoma cell line (Akata(+)EBERs(-)) as well as EBV-infected (Akata(+)) and EBV uninfected (Akata(-)) cell lines. They all have the same genetic backgrounds. First, 15 different cellular miRNAs which have reverse complementary sequences to EBERs and have reported targets were selected by bioinformatics analysis. When RT-PCR was carried out for the 16 miRNAs using RNAs from Akata(+), Akata(-), and Akata(+)EBERs(-) cells, hsa-miR-7-5p was the only one showing down-regulated expression in Akata(+) than in Akata(-) and Akata(+)EBERs(-) cells. Bioinformatics and mRNA microarray analyses for Akata(+), Akata(-), and Akata(+)EBERs(-) cell lines were then carried out to predict putative targets of hsa-miR-7-5p. Among the 6 predicted targets of hsa-miR-7-5p, only low density lipoprotein receptor-related protein 6 (LRP6) was up-regulated in EBERs-expressing cells when tested by RT-PCR and Western blot. However, luciferase reporter assay showed that the 3'-UTR of LRP6 was not directly targeted by hsa-miR-7-5p. Our data suggest that both hsa-miR-7-5p and LRP6 are regulated by EBERs in Akata cells, and these genes may partly mediate the tumorigenic function of EBERs in Burkitt's lymphoma.