scholarly journals MiR-9 Regulates the Expression of BACE1 in Dementia Induced by Chronic Brain Hypoperfusion in Rats

2017 ◽  
Vol 42 (3) ◽  
pp. 1213-1226 ◽  
Author(s):  
Hailong Xie ◽  
Ying Zhao ◽  
You Zhou ◽  
Lin Liu ◽  
Yueting Liu ◽  
...  

Background/Aims: MicroRNA-9 (miR-9) plays important roles in nervous system diseases such as glioblastoma and neurodegenerative disorders. However, how miR-9 contributes to dementia requires further study. In this study, we evaluated the role of miR-9 in dementia and the molecular mechanisms underlying its effects. Methods: A rat model of dementia was created by occlusion of the bilateral common carotid artery (2VO) for 8 weeks. Learning and memory were assessed using the Morris Water Maze (MWM). MicroRNA expression profiling was performed according to a protocol provided by LC Sciences, and quantitative real-time PCR (qRT-PCR) was used to detect the level of miR-9. Transmission electron microscopy (TEM) and hematoxylin-eosin (HE) staining were used to assess pathological changes in brain tissue. Western blot and immunofluorescence were employed to detect the expression of β-site APP cleaving enzyme 1 (BACE1) and c-AMP response element-binding protein (CREB). Results: Learning and memory were significantly impaired in 2VO rats, and these changes were accompanied by neuronal loss and glial activation in brain tissues. miR-9 was greatly upregulated in both the hippocampus and cortex of rats following 2VO. Knockdown of endogenous miR-9 via lentiviral vector-mediated delivery of its antisense molecule (lenti-pre-AMO-miR-9) reduced the vulnerability to dementia, reversed the increase in BACE1 expression, and ameliorated the reduction in CREB expression triggered by 2VO. BACE1 protein levels were significantly increased, but CREB protein levels were significantly decreased in the presence of miR-9 in cultured neonatal rat neurons (NRNs). AMO-miR-9 rescued the upregulation of BACE1 and downregulation of CREB elicited by miR-9 in rats. Dual luciferase assay experiments showed that overexpression of miR-9 inhibited the expression of CREB by targeting its 3’UTR domain. CREB protein was downregulated by miR-9 overexpression which was reversed by miR-9 inhibition in cultured NRNs. TEM imaging showed that miR-9 caused damage to NRNs, which was reversed by addition of AMO-miR-9. Conclusion: We conclude that miR-9 plays an important role in regulating the process of dementia induced by 2VO in rats by increasing BACE1 expression via downregulation of CREB.

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Hung-Hsing Chao ◽  
Li-Chin Sung ◽  
Cheng-Hsien Chen ◽  
Ju-Chi Liu ◽  
Jin-Jer Chen ◽  
...  

This study investigated how lycopene affected urotensin-II- (U-II-) induced cardiomyocyte hypertrophy and the possible implicated mechanisms. Neonatal rat cardiomyocytes were exposed to U-II (1 nM) either exclusively or following 6 h of lycopene pretreatment (1–10 μM). The lycopene (3–10 μM) pretreatment significantly inhibited the U-II-induced cardiomyocyte hypertrophy, decreased the production of U-II-induced reactive oxygen species (ROS), and reduced the level of NAD(P)H oxidase-4 expression. Lycopene further inhibited the U-II-induced phosphorylation of the redox-sensitive extracellular signal-regulated kinases. Moreover, lycopene treatment prevented the increase in the phosphorylation of serine-threonine kinase Akt and glycogen synthase kinase-3beta (GSK-3β) caused by U-II without affecting the protein levels of the phosphatase and tensin homolog deleted on chromosome 10 (PTEN). However, lycopene increased the PTEN activity level, suggesting that lycopene prevents ROS-induced PTEN inactivation. These findings imply that lycopene yields antihypertrophic effects that can prevent the activation of the Akt/GSK-3βhypertrophic pathway by modulating PTEN inactivation through U-II treatment. Thus, the data indicate that lycopene prevented U-II-induced cardiomyocyte hypertrophy through a mechanism involving the inhibition of redox signaling. These findings provide novel data regarding the molecular mechanisms by which lycopene regulates cardiomyocyte hypertrophy.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1809-1809
Author(s):  
Jiye Liu ◽  
Teru Hideshima ◽  
Lijie Xing ◽  
Kenneth Wen ◽  
Yu-Tzu Tai ◽  
...  

The development of novel agents including immunomodulatory drugs (IMiDs) lenalidomide (Len) and pomalidomide (Pom) has led to improved patient outcome in multiple myeloma (MM); however, acquired resistance to IMiDs commonly underlies relapse during the course of treatment. Previous studies show that IMiDs bind to the CRL4CRBN ubiquitin ligase cereblon (CRBN) and promote proteasomal degradation of IKZF1 and IKZF3 followed by downregulation of c-Myc and IRF4, resulting in MM cell growth inhibition. Therefore, CRBN is the primary binding target and master regulator of IMiDs sensitivity; however, the molecular mechanisms regulating resistance to IMiDs have not been fully defined. Importantly, some MM cells show resistance to IMiDs despite harboring high CRBN expression levels. To delineate the molecular mechanisms underlying IMiDs resistance, we first performed genome-wide knockout screening in IMiDs-sensitive MM.1S cells using a CRISPR-Cas9 GeCKOv2 library containing 6 unique sgRNAs against each of 19,050 genes and 4 sgRNAs against each of 1,864 miRNAs. We observed that knockout (KO) of twenty-eight genes and one miRNA were associated with resistance to IMiDs. Of note, all six sgRNAs targeting CRBN were identified as a positive regulator of IMiDs sensitivity, consistent with previous studies. Among these genes, we found that three different sgRNAs targeting TRAF2 were enriched after IMiDs treatment. Therefore, we next individually cloned the sgRNAs of TRAF2 into the Cas9 lentiviral vector, and then re-introduced them into MM.1S cells. Importantly, TRAF2-KO MM.1S cells acquire significant resistance to Pom and Len treatment. To examine whether TRAF2 KO induced IMiDs resistance was CRBN-pathway dependent, we assessed CRBN and its downstream interacting protein levels. TRAF2 KO showed no effect on CRBN expression; moreover, IMiDs can still trigger IKZF1 and IKZF3 degradation, associated with downregulation of IRF4. Taken together, these data suggest that TRAF2 mediates sensitivity to IMiDs in a mechanism independent of CRBN-IKZF1/3 axis. Since TRAF2 is a member of the TNF receptor associated factor (TRAF) protein family required for activation of several signaling pathways including NF-ĸB and JNK, we next examined the biologic impact of TRAF2 KO. Importantly, TRAF2 KO cells show significantly increased processing of precursor p100 to p52 (NF-ĸB2), resulting in hyperactivation of the non-canonical NF-κB pathway; conversely, p52 KO re-sensitizes the cells to IMiDs treatment. The activity of the canonical NF-κB pathway was not similarly altered in TRAF2 KO cells. These results suggest that TRAF2 predominantly activates non-canonical NF-κB pathway, associated with resistance to IMiDs in MM cells. We next examined the relevance of TRAF2 downregulation in the context of the bone marrow (BM) microenvironment. Co-culture of MM cells with either bone marrow stromal cells (BMSCs) or culture supernatants (BM-CS) confers resistance to IMiDs. Importantly, TRAF2 is downregulated in BMSCs and BM-CS, suggesting that IMiDs resistance in the BM microenvironment may be mediated by TRAF2 downregulation induced by soluble factors. Cytokine array assay confirmed detectable TNF-α in BM-CS. Indeed, MM cells treated with TNF-α showed decreased TRAF2 expression, associated with resistance to IMiDs. These data demonstrate that TNF-α secreted by BMSCs induces TRAF2 downregulation, thereby inducing IMiDs resistance. We further analyzed the mechanism of TNF-α-mediated TRAF2 downregulation. Since previous studies have shown that TRAF2 is a substrate of the proteasome, we treated MM cells with TNF-α in the presence and absence of proteasome inhibitor. TRAF2 downregulation by TNF-α was partially abrogated by proteasome inhibitor, associated with accumulation of ubiquitinated TRAF2. These data confirm that TNF-α induces TRAF2 downregulation is due, at least in part to proteasomal degradation. In conclusion, our data show that TRAF2 is a CRBN-independent regulator of IMiDs sensitivity and provide the preclinical rationale for combining IMiDs with inhibitors of non-canonical NF-κB or TNF-α signaling to overcome IMiDs resistance and improve patient outcome. Disclosures Anderson: Sanofi-Aventis: Other: Advisory Board; Amgen: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Takeda: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Bristol-Myers Squibb: Other: Scientific Founder; Oncopep: Other: Scientific Founder.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Shanshan Wei ◽  
Zhiwen Zhang ◽  
Lu Yan ◽  
Yinjuan Mo ◽  
Xianwen Qiu ◽  
...  

Objective. Lupus nephritis is the most common and severe complication of systemic lupus erythematosus. The aim of our study was to investigate the efficacy of miR-20a overexpressing adipose-derived stem cell (ADSC) transplantation in murine lupus nephritis (LN) and explore potential molecular mechanisms. Methods. Mouse ADSCs were transfected with a miR-20a lentiviral vector to obtain miR-20a overexpression ADSCs (miR-20a-ADSCs). We first observed the influence of miR-20a on ADSC viability and apoptosis in vitro. B6.MRL/lpr mice were administered ADSC/miR-20a-ADSC intravenously every week from age 30 to 33 weeks, and the lupus and normal control groups received PBS on the same schedule. Results. miR-20a expression increased in miR-20a-ADSC-derived exosomes, and miR-20a overexpression promoted ADSC proliferation and inhibited apoptosis. Compared with ADSCs, miR-20a-ADSC treatment significantly improved serologic and histologic abnormalities, as evidenced by reduced serum creatinine, anti-dsDNA antibody, 24 h urine protein levels, nephritis scores, and C3/IgG deposits. Furthermore, miR-20a-ADSC treatment resulted in downregulated Akt, mTOR, and p62 expression and upregulated miR-20a, Beclin 1, and LC3 II/I expression compared with ADSC treatment. After treatment with miR-20a-ADSC, a significant increase in the number of autophagosomes within podocytes was observed, along with upregulated expression of podocin and nephrin, compared with the ADSC group. Conclusions. miR-20a-ADSC transplantation prevents the development of lupus nephritis and significantly ameliorates already-established disease, and its mechanism is related to autophagy by targeting the miR-20a-regulated mTOR pathway.


2003 ◽  
Vol 285 (6) ◽  
pp. C1349-C1355 ◽  
Author(s):  
Ping-Ping Kuang ◽  
Ronald H. Goldstein

We previously showed that interleukin (IL)-1β decreases elastin gene transcription through activation of the NF-κB subunit p65 in neonatal rat lung fibroblasts. The present study was undertaken to further explore the molecular mechanisms responsible for the inhibitory effect of IL-1β on elastin gene transcription. We found that cycloheximide blocked IL-1β-induced downregulation of elastin mRNA but did not inhibit IL-1β-induced translocation of p65 into the nucleus. IL-1β treatment increased CCAAT/enhancer-binding protein (C/EBP)β mRNA and protein levels including liver-enriched activating protein (LAP) and liver-enriched inhibitory protein (LIP), which was cycloheximide sensitive. C/EBPβ isoforms bound a GCAAT-containing sequence in the proximal elastin promoter as determined by electrophoretic gel shift studies and confirmed by using specific anti-C/EBPβ antibodies and by competition studies with oligonucleotides. Transient transfection of LIP expression vectors strongly decreased the transcriptional activity of the cotransfected elastin promoter and decreased levels of endogenous elastin mRNA. We demonstrated that IL-1β-induced downregulation of elastin mRNA is dependent on NF-κB activation and C/EBPβ expression. These results indicate that IL-1β treatment activates NF-κB, which subsequently induces LIP expression and inhibition of elastin gene transcription.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Xiaoying Fan ◽  
Enbo Zhan ◽  
Yuan Yao ◽  
Ruoxi Zhang ◽  
Yong Sun ◽  
...  

Oxidative stress is a crucial factor and key promoter of a variety of cardiovascular diseases associated with cardiomyocyte injury. Emerging literatures suggest that pyroptosis plays a key role in cardiac damages. However, whether pyroptosis contributes to cardiomyocyte injury under oxidative stress and the underlying molecular mechanisms are totally unclear. This study was designed to investigate the potential role of pyroptosis in H2O2-induced cardiomyocyte injury and to elucidate the potential mechanisms. Primary cardiomyocytes from neonatal Wistar rats were utilized. These myocytes were treated with different concentrations of H2O2 (25, 50, and 100 μM) for 24 h to induce oxidative injury. Our results indicated that mRNA and protein levels of ASC were remarkably upregulated and caspase-1 was activated. Moreover, the expressions of inflammatory factors IL-1β and IL-18 were also increased. Luciferase assay showed that miR-599 inhibited ASC expression through complementary binding with its 3 ′ UTR. MiR-599 expression was substantially reduced in H2O2-treated cardiomyocytes. Upregulation of miR-599 inhibited cardiomyocyte pyroptosis under oxidative stress, and opposite results were found by decreasing the expression of miR-599. Consistently, miR-599 overexpression ameliorated cardiomyocyte injury caused by H2O2. Therefore, miR-599 could be a promising therapeutic approach for the management of cardiac injury under oxidative condition.


2020 ◽  
Vol 21 (11) ◽  
pp. 4131
Author(s):  
Mary Jasmin Ang ◽  
Juhwan Kim ◽  
Sueun Lee ◽  
Sung-Ho Kim ◽  
Jong-Choon Kim ◽  
...  

Lipid homeostasis is an important component of brain function, and its disturbance causes several neurological disorders, such as Huntington’s, Alzheimer’s, and Parkinson’s diseases as well as mood disorders. Sterol regulatory element-binding protein-1c (SREBP-1c) is a key modulatory molecule involved in lipid homeostasis in the central nervous system. However, little is known about the biological effects of SREBP-1c in the brain. Our previous study uncovered that mice deficient in SREBP-1c exhibit schizophrenia-like behaviors. To investigate whether there are novel molecular mechanisms involved in the neurological aberrations caused by SREBP-1c deficiency, we analyzed the transcriptomes of the hippocampus of SREBP-1c knockout (KO) mice and wild-type mice. We found seven differentially expressed genes (three up-regulated and four down-regulated genes) in the hippocampus of SREBP-1c KO mice. For further verification, we selected the three most significantly changed genes: glucagon-like peptide 2 receptors (GLP2R) involved in hippocampal neurogenesis and neuroplasticity as well as in cognitive impairments; necdin (NDN) which is related to neuronal death and neurodevelopmental disorders; and Erb-B2 receptor tyrosine kinase 4 (ERBB4) which is a receptor for schizophrenia-linked protein, neuregulin-1. The protein levels of GLP2R and NDN were considerably decreased, but the level of ERBB4 was significantly increased in the hippocampus of SREBP-1c KO mice. However, further confirmation is warranted to establish the translatability of these findings from this rodent model into human patients. We suggest that these data provide novel molecular evidence for the modulatory role of SREBP-1c in the mouse hippocampus.


Author(s):  
Hongtao Li ◽  
Peng Chen ◽  
Lei Chen ◽  
Xinning Wang

Background: Nuclear factor kappa B (NF-κB) is usually activated in Wilms tumor (WT) cells and plays a critical role in WT development. Objective: The study purpose was to screen a NF-κB inhibitor from natural product library and explore its effects on WT development. Methods: Luciferase assay was employed to assess the effects of natural chemical son NF-κB activity. CCK-8 assay was conducted to assess cell growth in response to naringenin. WT xenograft model was established to analyze the effect of naringenin in vivo. Quantitative real-time PCR and Western blot were performed to examine the mRNA and protein levels of relative genes, respectively. Results: Naringenin displayed significant inhibitory effect on NF-κB activation in SK-NEP-1 cells. In SK-NEP-1 and G-401 cells, naringenin inhibited p65 phosphorylation. Moreover, naringenin suppressed TNF-α-induced p65 phosphorylation in WT cells. Naringenin inhibited TLR4 expression at both mRNA and protein levels in WT cells. CCK-8 staining showed that naringenin inhibited cell growth of the two above WT cells in dose-and time-dependent manner, whereas Toll-like receptor 4 (TLR4) over expression partially reversed the above phenomena. Besides, naringenin suppressed WT tumor growth in dose-and time-dependent manner in vivo. Western blot found that naringenin inhibited TLR4 expression and p65 phosphorylation in WT xenograft tumors. Conclusion: Naringenin inhibits WT development viasuppressing TLR4/NF-κB signaling


2021 ◽  
pp. 1-13
Author(s):  
Jing Zhu ◽  
Chunxia Guo ◽  
Pingping Lu ◽  
Shuijin Shao ◽  
Bing Tu

<b><i>Background:</i></b> Electroacupuncture (EA) can improve trauma-induced hypothalamus pituitary adrenal axis (HPA) hyperactivity. However, the mechanism underlying the EA effect has not been fully understood. <b><i>Methods and Study Design:</i></b> This study was undertaken to explore the role of hypothalamic growth arrest-specific 5 (Gas5) in the regulation of EA on HPA axis function post-surgery. Paraventricular nuclear Gas5 levels were upregulated in rats using an intracerebroventricular injection of pAAV-Gas5. Primary hypothalamic neurons and 293T cells were cultured for miRNA and siRNAs detection. Radioimmunoassay, PCR, Western blot, and immunohistochemistry were used for HPA axis function evaluation. <b><i>Results:</i></b> The overexpression of Gas5 abolished the effect of EA on the regulation of trauma-induced HPA axis hyperactivity. Using a bioinformatics analysis and dual luciferase assay, we determined that miRNA-674 was a target of Gas5. Additionally, miRNA-674 levels were found to have decreased in trauma rats, and this effect was reversed after EA intervention. TargetScan analysis showed that serum and glucocorticoid inducible kinase 1 (SGK1) were targets of miR-674. Moreover, we found that SGK1 protein levels increased in trauma rats and SGK1 expression inhibition alleviated HPA axis abnormality post-surgery. EA could improve the number of hypothalamus iba-1 positive cells and hypothalamic interleukin 1 beta protein expression. <b><i>Conclusions:</i></b> Our study demonstrated the involvement of the hypothalamic Gas5/miRNA-674/SGK1 signaling pathway in EA regulation of HPA axis function after trauma.


ASN NEURO ◽  
2021 ◽  
Vol 13 ◽  
pp. 175909142110097
Author(s):  
Kui Cui ◽  
Fan Yang ◽  
Turan Tufan ◽  
Muhammad U. Raza ◽  
Yanqiang Zhan ◽  
...  

Dysfunction of the central noradrenergic and dopaminergic systems is the primary neurobiological characteristic of Parkinson’s disease (PD). Importantly, neuronal loss in the locus coeruleus (LC) that occurs in early stages of PD may accelerate progressive loss of dopaminergic neurons. Therefore, restoring the activity and function of the deficient noradrenergic system may be an important therapeutic strategy for early PD. In the present study, the lentiviral constructions of transcription factors Phox2a/2b, Hand2 and Gata3, either alone or in combination, were microinjected into the LC region of the PD model VMAT2 Lo mice at 12 and 18 month age. Biochemical analysis showed that microinjection of lentiviral expression cassettes into the LC significantly increased mRNA levels of Phox2a, and Phox2b, which were accompanied by parallel increases of mRNA and proteins of dopamine β-hydroxylase (DBH) and tyrosine hydroxylase (TH) in the LC. Furthermore, there was considerable enhancement of DBH protein levels in the frontal cortex and hippocampus, as well as enhanced TH protein levels in the striatum and substantia nigra. Moreover, these manipulations profoundly increased norepinephrine and dopamine concentrations in the striatum, which was followed by a remarkable improvement of the spatial memory and locomotor behavior. These results reveal that over-expression of these transcription factors in the LC improves noradrenergic and dopaminergic activities and functions in this rodent model of PD. It provides the necessary groundwork for the development of gene therapies of PD, and expands our understanding of the link between the LC-norepinephrine and dopamine systems during the progression of PD.


2021 ◽  
pp. 1-9
Author(s):  
Guizhen Liu ◽  
Yuchuan Sun ◽  
Fei Liu

<b><i>Objective:</i></b> The purpose of this study was to explore the role of curcumin (Cur) in isoflurane (ISO)-induced learning and memory dysfunction in Sprague-Dawley rats and further elucidate the mechanism of the protective effect produced by Cur. <b><i>Methods:</i></b> Rat models of cognitive impairment were established by inhaling 3% ISO. The Morris water maze test was used to assess the cognitive function of rats. ELISA and qRT-PCR were used to analyze the protein levels of pro-inflammatory cytokines and expression levels of miR-181a-5p, respectively. <b><i>Results:</i></b> Cur significantly improved the ISO-induced cognitive dysfunction in rats and alleviated the ISO-induced neuroinflammation. miR-181a-5p was overexpressed in ISO-induced rats, while Cur treatment significantly reduced the expression of miR-181a-5p. Overexpression of miR-181a-5p promoted the cognitive impairment and the release of inflammatory cytokines and reversed the neuroprotective effect of Cur. <b><i>Conclusion:</i></b> Cur has a protective effect on ISO-induced cognitive dysfunction, which may be achieved by regulating the expression of miR-181a-5p.


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