scholarly journals Uptake of Aβ by OATPs Might Be a New Pathophysiological Mechanism of Alzheimer Disease

Author(s):  
JinHua Wen ◽  
MengHua Zhao ◽  
Ying Zhou ◽  
YanNi Lv

Abstract BackgroundThe accumulation of neurotoxic amyloid-beta (Aβ) in the brain is a characteristic of Alzheimer's disease (AD). Over the last decade, a number of reports have shown that P-glycoprotein (encoded by ABCB1) actively mediates the efflux transport of Aβ peptides. However, the mechanism by which Aβ peptides enter the cells is not clear. We found that the protein expression oforganic anion transporting Polypeptide 2 (Oatp2) in the liver tissue of mice with AD was significantly higher than that in the normal mice. In contrast, the protein expression of Oatp2 in the brain significantly decreased in mice with AD. OATP1B1, an important drug transporter might be related to the pathophysiology of AD. ResultsIn this study, we established an OATP1B1-GFP-HEK293T cell model to confirm the OATP1B1 mediated transport ofAβ1-42.Compared to the control group of GFP-HEK293Tcells, the uptake of Aβ1-42 protein in the OATP1B1-GFP-HEK293T group increased significantly with the increase in concentration of Aβ1-42, and also increased significantly with an increase in the duration of incubation. Similar results were observed in the flow cytometry experiment, and the uptake of Aβ1-42in HEK239T-OATP1B1 cells was almost twice that in the control group. These results indicate that OATP1B1 acts as an important “carrier” for the transport of Aβ1-42 from the blood to the tissues, including liver and brain. ConclusionsThis is a novel and interesting finding and OATP1B1 can be investigated as a new treatment target for AD.

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jinhua Wen ◽  
Menghua Zhao ◽  
Wenxiong Sun ◽  
Xiaohua Cheng ◽  
Luyi Yu ◽  
...  

Abstract Background The accumulation of neurotoxic amyloid-beta (Aβ) in the brain is a characteristic of Alzheimer's disease (AD), at the same time, it is possible alterations of liver function could affect brain Aβ levels through changes in blood Aβ concentration. Over the last decade, a number of reports have shown that P-glycoprotein (encoded by ABC1B1) actively mediates the efflux transport of Aβ peptides. However, the mechanism by which Aβ peptides enter the cells is not clear. In the preliminary study, we found that the protein expression of organic anion transporting Polypeptide 1a4 (OATP1B1) in the liver tissue of mice with AD was significantly higher than that in the normal mice. In contrast, the protein expression of Oatp1a4 in the brain significantly decreased in mice with AD. OATP1B1, an important drug transporter might be related to the pathophysiology of AD. Results In this study, we established an OATP1B1-GFP-HEK293T cell model to confirm the OATP1B1 mediated transport of Aβ1-42. Compared to the control group of GFP-HEK293Tcells, the uptake of Aβ1-42 protein in the OATP1B1-GFP-HEK293T group increased significantly with the increase in concentration of Aβ1-42, and also increased significantly with an increase in the duration of incubation. Similar results were observed in the flow cytometry experiment, and the uptake of Aβ1-42in HEK293T-OATP1B1 cells was almost twice that in the control group. These results indicate that OATPs may act as an important “carrier” for the transport of Aβ1-42 from the blood to the tissues, including liver and brain. Conclusions This is a novel and interesting finding and OATP1B1 can be investigated as a new treatment target for AD.


2020 ◽  
Vol 21 (6) ◽  
pp. 471-478
Author(s):  
Shenjia Huang ◽  
Qingqing Xu ◽  
Linsheng Liu ◽  
Yicong Bian ◽  
Shichao Zhang ◽  
...  

Background: Green tea can inhibit OATPs, so it may interact with the substrate of OATPs, such as rosuvastatin. Objective: This study aimed to investigate the effects of green tea on the pharmacokinetics of rosuvastatin and its mechanism. Methods: Male Sprague-Dawley rats received different doses of green tea extract (GTE) and (-)- epigallocatechin-3- gallate (EGCG). Caco-2 cells and OATP1B1-HEK293T cells were used in drug uptake and transport assay. The matrix concentrations of rosuvastatin and catechins were determined by ultra-performance liquid chromatographytandem mass spectrometry (UPLC-MS/MS). Results: GTE and EGCG were both found to increase the area under the plasma concentration-time curve (AUC0-∞) of rosuvastatin ((p<0.050). In the Caco-2 cell model, the uptake and transport of rosuvastatin in the GTE groups were 1.94-fold (p<0.001) and 2.11-fold (p<0.050) higher, respectively, than those of the control group. However, in the EGCG group, the uptake and transport of rosuvastatin were decreased by 22.62% and 44.19%, respectively (p<0.050). In the OATP1B1- HEK293T cell model, the OATP1B1-mediated rosuvastatin uptake was decreased by GTE to 35.02% of that in the control (p<0.050) and was decreased by EGCG to 45.61% of that in the control (p<0.050). Conclusion: GTE increased the systemic rosuvastatin exposure in rats. The mechanism may include an increase in rosuvastatin absorption and a decrease in liver distribution by inhibiting OATP1B1. EGCG may be the main ingredient of green tea that affects the pharmacokinetic parameters of rosuvastatin. Our results showed the importance of conducting green tea-rosuvastatin study.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1106-1106
Author(s):  
Rong Fu ◽  
Yingying Chen ◽  
Zonghong Shao ◽  
Hui Liu ◽  
Lijie Zeng ◽  
...  

Abstract Paroxysmal nocturnal hemoglobinuria (PNH) is a disease of hematopoietic stem cell membrane defects due to acquired PIG-Amutation. Our previous study found some secondary gene mutations in PNH patients by WES. However, it is not clear exactly which mutations are associated with the disease. So, 97 target genes were selected as a target gene panel and tested in 23 PNH patients by DNA sequencing of specific target regions. We found that all PNH patients had other gene mutations except PIG-Amutations, including TTN, NCOR2, CPS1, MUC4, SUZ12, LFNG, CELSR2, JAK2, SETBP1 and KMT2D (Figure1A). Through harmful analysis, KEGG enrichment, GO enrichment analysis and protein interaction analysis, we screened out the secondary mutant gene SUZ12 that may be involved in the cloning proliferation of PNH. We detected the mRNA and protein expression levels of SUZ12 and H3K27me3 methylation in PNH patients and health volunteers, the results showed that the mRNA and protein expression levels of SUZ12 and H3K27me3 methylation in peripheral blood CD59 -cells of PNH patients were higher than those in CD59 + cells of PNH patients and healthy controls (Figure1B). The relative expression level of SUZ12 in peripheral blood CD59 -cells of PNH patients was correlated with (r=0.4162, p=0.0385), CD59 -erythrocyte ratio (r=0.4636, p=0.0196), CD59 -monocyte ratio (r=0.4052, p=0.0495), Flaer -monocyte ratio (r=0.6769, p=0.0004) and Flaer -granulocytic ratio (r=0.6146, p=0.0018), indicating that SUZ12 may be involved in abnormal PNH cloning and proliferation by regulating H3K27me3. To verify the role of SUZ12 in the proliferation of PNH cloning, we used CRISPR/Cas9 to knockdown PIG-A expression in THP-1 cells to construct A PNH cell model, the expression level of PIG-A protein in the cell model was significantly decreased, and the proportion of CD59 - cells accounted was stable at 95%. Then lentivirus transfection was used to knockdown the expression of SUZ12 in PNH cell model. The results showed when the SUZ12 expression was knockdown, the methylation level of histone H3K27me3 was decreased, the cell proliferation activity was decreased, apoptosis was increased, and the cell cycle was arrested at G0/G1 phase. The proportion of CD59 + cells increased gradually from 3 weeks after transfection, and significantly increased at 4 weeks after transfection, while no changes were observed in the empty virus group and control group (Figure1C). Four weeks after lentivirus transfection, the expression of PIG-A protein recovered in SUZ12 knockdown group compared with empty virus group and control group (Figure1D). In conclusion, SUZ12 mutation leads to the overexpression of SUZ12, which can affect cell proliferation, apoptosis and cell cycle by regulating the methylation level of histone H3K27me3, thereby promoting the proliferation of PNH abnormal cloning and participating in the pathogenesis of PNH. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.


2021 ◽  
Vol 11 (5) ◽  
pp. 1010-1016
Author(s):  
Weifeng Zha ◽  
Bo Guo ◽  
Shuyue Chen ◽  
Junwei Lu ◽  
Yunyun Shan

Objective: The study was aimed to explore the roles of miR-126-5p in psoriasis and the underlying molecular mechanisms. Methods: In vitro cell model of psoriasis was established by IL-22 induction. CASP1, the target gene of miR-126-5p, was predicted by TargetScan and verified through the dual luciferase reporter gene system. qRT-PCR was used to measure the mRNA expression of miR-126-5p and CASP1 in IL-22 stimulated HaCaT cells. The protein expression of CASP1, cleaved-caspase3 and caspase3 were measured by Western blot analysis. MTT assay and flow cytometry analysis were performed to detect the cell proliferation and apoptosis. A Caspase3 Activity Assay kit was used to detect the activity of Caspase3. Results: miR-126-5p was high expressed in IL-22 stimulated HaCaT cells compared with normal HaCaT cells. We predicted and verified that CASP1 was a direct target of miR-126-5p, and the mRNA and protein expression of CASP1 were reduced in IL-22 stimulated HaCaT cells compared with the normal HaCaT cells. miR-126-5p inhibitor and CASP1-siRNA significantly decreased the expression of miR-126-5p and CASP1 in HaCaT cells respectively. miR-126-5p inhibitor up-regulated the expression of CASP1 in HaCaT cells, and the effect was reversed by the transfection with CASP1-siRNA. In comparison with the control group, miR-126-5p inhibitor decreased the cell proliferation, induced apoptosis, and improved the activity of Caspase3, enhanced cleaved-caspase3/caspase3 ratio in IL-22 stimulated HaCaT cells, and all the effects were reversed by down-regulating CASP1. Conclusion: We demonstrated that miR-126-5p inhibitor played a protective role in psoriasis by targeting CASP1, evidenced by inhibiting IL-22-induced HaCaT cell proliferation and inducing apoptosis.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5953-5953
Author(s):  
Fan Yi Meng ◽  
Ling Jiang ◽  
Qingxiu Zhong ◽  
Li Chun Wang ◽  
Guopan Yu ◽  
...  

Abstract Our previous study has been reported that AML1/ETO positive patients with highly expressed of APP were much easier to extramedullary infiltration, and got poor prognosis£¨followed-up median 35 ( 6-96 ) months, RFS in the high expression APP group was significantly lower than the low expression group £¬40.0% vs 80.0%£¬P = 0.001). In vitro study, we constructed a cell model kasumi-1 which was consistent with AML1/ETO positive and high expressed of APP gene. The cell migration was significantly reduced after interferce of APP expression. This study was designed to investigate the molecule mechanism of extramedullary leukemia (EML) in kasumi-1 cell model and to invent a strategy for treatment in clinic. In this study, we found p-ERK, c-Myc and MMP-2 were significantly decreased after APP expression knockdown in kasumi-1 cell. Meanwhile, we added the inhibitors to block p-ERK and c-Myc expression. The results showed that protein expression of p-ERK and c-Myc was significantly decreased after p-ERK inhibitor performance, which was proportional to the time and concentration. c-Myc and MMP-2 protein expression was significantly reduced after c-Myc inhibitor was used, but p-ERK didn't change (Fig.1B). So, we concluded that APP might regulated the AML cell migration via APP/p-ERK/c-Myc/MMP-2 pathway. Also, we found that kasumi-1 cell was resistant to adriamycin (ADM) and Ara-C, which meant APP may be related with drug resistance. So, we detected cell surviving fraction after ADM and Ara-C performance via MTT assay. The results showed that there was no difference in control group and siAPP group. But, when compared with controls groups, cell surviving fraction in siEZH2 group was significantly decreased after ADM and Ara-C performance respectively. Furthermore, we found protein expression of EZH2 was significantly reduced after LBH589 treatment in cell culture. So, we concluded that LBH589 or SiEZH2 could increase sensitivity of kasumi-1 cell to ADM and Ara-C. In sum, in AML1/ETO positive leukemia cells, we first report that APP gene regulates cell migration via APP/p-ERK/c-Myc/MMP-2 pathway and EZH2 gene induces drug resistantence. Interference or blocking of EZH2 and APP expression may be helpful in treating AML1/ETO positive leukemia. Disclosures No relevant conflicts of interest to declare.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 93-93
Author(s):  
Hyoeun Yoo ◽  
Hyun-Sook Kim

Abstract Objectives Healthy aging is one of the most attentive topics since senescence may lead to retrogression of antioxidative ability, inflammatory regulation and neurodegeneration. This study was performed to determine the antioxidative effects of cacao powder supplementation in d-galactose induced aging rat model. Methods After 3 weeks of adaptation period, 12-week-old SD rats were randomly divided into four groups (n = 8 each): Control group (C), D-galactose induced aging group (G), D-galactose injection with 10% cacao powder group (LC), D-galactose injection with 16% cacao powder group (HC) (10%, 16% is % per total food weight). G, LC, HC groups were intraperitoneally injected with D-galactose for 8 weeks and C group was treated with saline as a substitute. Results After 8 weeks of cacao powder supplementation, serum malondialdehyde (MDA), advanced glycation end (AGE) levels, and Liver malondialdehyde (MDA) level significantly decreased in LC, HC group compared to G group (P &lt; 0.05). Protein expression of SOD2 and CAT in the brain showed significant increase in LC and HC group compared to G group (P &lt; 0.05). Protein expression of Gpx1 in the brain tends to increase in LC and HC group compared to G group but did not show statistical significance. Conclusions This study demonstrates that dietary cacao powder supplementation can alleviate oxidative stress by regulating oxidative stress markers like MDA and AGE or antioxidant enzymes such as SOD2 and CAT in d-galactose induced aging rat model. Funding Sources This study was funded by Nutritional Immunology Lab of Sookmyung Women's University.


Author(s):  
Zafer Sahin ◽  
Alpaslan Ozkurkculer ◽  
Omer Faruk Kalkan ◽  
Ahmet Ozkaya ◽  
Aynur Koc ◽  
...  

Abstract. Alterations of essential elements in the brain are associated with the pathophysiology of many neuropsychiatric disorders. It is known that chronic/overwhelming stress may cause some anxiety and/or depression. We aimed to investigate the effects of two different chronic immobilization stress protocols on anxiety-related behaviors and brain minerals. Adult male Wistar rats were divided into 3 groups as follows ( n = 10/group): control, immobilization stress-1 (45 minutes daily for 7-day) and immobilization stress-2 (45 minutes twice a day for 7-day). Stress-related behaviors were evaluated by open field test and forced swimming test. In the immobilization stress-1 and immobilization stress-2 groups, percentage of time spent in the central area (6.38 ± 0.41% and 6.28 ± 1.03% respectively, p < 0.05) and rearing frequency (2.75 ± 0.41 and 3.85 ± 0.46, p < 0.01 and p < 0.05, respectively) were lower, latency to center area (49.11 ± 5.87 s and 44.92 ± 8.04 s, p < 0.01 and p < 0.01, respectively), were higher than the control group (8.65 ± 0.49%, 5.37 ± 0.44 and 15.3 ± 3.32 s, respectively). In the immobilization stress-1 group, zinc (12.65 ± 0.1 ppm, p < 0.001), magnesium (170.4 ± 1.7 ppm, p < 0.005) and phosphate (2.76 ± 0.1 ppm, p < 0.05) levels were lower than the control group (13.87 ± 0.16 ppm, 179.31 ± 1.87 ppm and 3.11 ± 0.06 ppm, respectively). In the immobilization stress-2 group, magnesium (171.56 ± 1.87 ppm, p < 0.05), phosphate (2.44 ± 0.07 ppm, p < 0.001) levels were lower, and manganese (373.68 ± 5.76 ppb, p < 0.001) and copper (2.79 ± 0.15 ppm, p < 0.05) levels were higher than the control group (179.31 ± 1.87 ppm, 3.11 ± 0.06 ppm, 327.25 ± 8.35 ppb and 2.45 ± 0.05 ppm, respectively). Our results indicated that 7-day chronic immobilization stress increased anxiety-related behaviors in both stress groups. Zinc, magnesium, phosphate, copper and manganese levels were affected in the brain.


2019 ◽  
Vol 4 (3) ◽  
pp. 141-144
Author(s):  
Evelin Szabó ◽  
Zsolt Parajkó ◽  
Diana Opincariu ◽  
Monica Chițu ◽  
Nóra Raț ◽  
...  

Abstract Atherosclerosis is the elemental precondition for any cardiovascular disease and the predominant cause of ischemic heart disease that often leads to myocardial infarction. Systemic risk factors play an important role in the starting and progression of atherosclerosis. The complexity of the disease is caused by its multifactorial origin. Besides the traditional risk factors, genetic predisposition is also a strong risk factor. Many studies have intensively researched cardioprotective drugs, which can relieve myocardial ischemia and reperfusion injury, thereby reducing infarct size. A better understanding of abnormal epigenetic pathways in the myocardial pathology may result in new treatment options. Individualized therapy based on genome sequencing is important for an effective future medical treatment. Studies based on multiomics help to better understand the pathophysiological mechanism of several diseases at a molecular level. Epigenomic, transcriptomic, proteomic, and metabolomic research may be essential in detecting the pathological phenotype of myocardial ischemia and ischemic heart failure.


2020 ◽  
Vol 23 (5) ◽  
pp. 402-410 ◽  
Author(s):  
Lin-Zi Li ◽  
Shan-Shan Lei ◽  
Bo Li ◽  
Fu-Chen Zhou ◽  
Ye-Hui Chen ◽  
...  

Aim and Objective: The Dendrobium officinalis flower (DOF) is popular in China due to common belief in its anti-aging properties and positive effects on “nourish yin”. However, there have been relatively few confirmatory pharmacological experiments conducted to date. The aim of this work was to evaluate whether DOF has beneficial effects on learning and memory in senescent rats, and, if so, to determine its potential mechanism of effect. Materials and Methods: SD rats were administrated orally DOF at a dose of 1.38, or 0.46 g/kg once a day for 8 weeks. Two other groups included a healthy untreated control group and a senescent control group. During the 7th week, a Morris water maze test was performed to assess learning and memory. At the end of the experiment, serum and brain samples were collected to measure concentrations of antioxidant enzymes, including malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GSH-Px) in serum, and the neurotransmitters, including γ-aminobutyric acid (γ-GABA), Glutamic (Glu), and monoamine oxidase B (MAO-B) in the brain. Histopathology of the hippocampus was assessed using hematoxylin-eosin (H&E) staining. Results: The results suggested that treatment with DOF improved learning as measured by escape latency, total distance, and target quadrant time, and also increased levels of γ-GABA in the brain. In addition, DOF decreased the levels of MDA, Glu, and MAO-B, and improved SOD and GSHPx. Histopathological analysis showed that DOF also significantly reduced structural lesions and neurodegeneration in the hippocampus relative to untreated senescent rats. Conclusion: DOF alleviated brain aging and improved the spatial learning abilities in senescent rats, potentially by attenuating oxidative stress and thus reducing hippocampal damage and balancing the release of neurotransmitters.


2020 ◽  
Vol 17 ◽  
Author(s):  
Van-An Duong ◽  
Jeeyun Ahn ◽  
Na-Young Han ◽  
Jong-Moon Park ◽  
Jeong-Hun Mok ◽  
...  

Background: Diabetic Retinopathy (DR), one of the major microvascular complications commonly occurring in diabetic patients, can be classified into Proliferative Diabetic Retinopathy (PDR) and Non-Proliferative Diabetic Retinopathy (NPDR). Currently available therapies are only targeted for later stages of the disease in which some pathologic changes may be irreversible. Thus, there is a need to develop new treatment options for earlier stages of DR through revealing pathological mechanisms of PDR and NPDR. Objective: The purpose of this study was to characterize proteomes of diabetic through quantitative analysis of PDR and NPDR. Methods: Vitreous body was collected from three groups: control (non-diabetes mellitus), NPDR, and PDR. Vitreous proteins were digested to peptide mixtures and analyzed using LC-MS/MS. MaxQuant was used to search against the database and statistical analyses were performed using Perseus. Gene ontology analysis, related-disease identification, and protein-protein interaction were performed using the differential expressed proteins. Results: Twenty proteins were identified as critical in PDR and NPDR. The NPDR group showed different expressions of kininogen-1, serotransferrin, ribonuclease pancreatic, osteopontin, keratin type II cytoskeletal 2 epidermal, and transthyretin. Also, prothrombin, signal transducer and activator of transcription 4, hemoglobin subunit alpha, beta, and delta were particularly up-regulated proteins for PDR group. The up-regulated proteins related to complement and coagulation cascades. Statherin was down-regulated in PDR and NPDR compared with the control group. Transthyretin was the unique protein that increased its abundance in NPDR compared with the PDR and control group. Conclusion: This study confirmed the different expressions of some proteins in PDR and NPDR. Additionally, we revealed uniquely expressed proteins of PDR and NPDR, which would be differential biomarkers: prothrombin, alpha-2-HS-glycoprotein, hemoglobin subunit alpha, beta, and transthyretin.


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