scholarly journals Down-regulation of the mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase gene by insulin: the role of the forkhead transcription factor FKHRL1

2002 ◽  
Vol 366 (1) ◽  
pp. 289-297 ◽  
Author(s):  
Alícia NADAL ◽  
Pedro F. MARRERO ◽  
Diego HARO
Keyword(s):  
Ketone Bodies ◽  
Control Site ◽  
Luciferase Reporter ◽  
Acid Oxidation ◽  
Transcription Start ◽  
Forkhead Transcription Factor ◽  
The Brain

Normal physiological responses to carbohydrate shortages cause the liver to increase the production of ketone bodies from the acetyl-CoA generated from fatty acid oxidation. This allows the use of ketone bodies for energy, thereby preserving the limited glucose for use by the brain. This adaptative response is switched off by insulin rapidly inhibiting the expression of the mitochondrial 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase (HMGCS2) gene, which is a key control site of ketogenesis. We decided to investigate the molecular mechanism of this inhibition. In the present study, we show that FKHRL1, a member of the forkhead in rhabdosarcoma (FKHR) subclass of the Fox family of transcription factors, stimulates transcription from transfected 3-hydroxy-3-methylglutaryl-CoA synthase promoter-luciferase reporter constructs, and that this stimulation is repressed by insulin. An FKHRL1-responsive sequence AAAAATA, located 211bp upstream of the HMGCS2 gene transcription start site, was identified by deletion analysis. It binds FKHRL1 in vivo and in vitro and confers FKHRL1 responsiveness on homologous and heterologous promoters. If it is mutated, it partially blocks the effect of insulin in HepG2 cells, both in the absence and presence of overexpressed FKHRL1. These results suggest that FKHRL1 contributes to the regulation of HMGCS2 gene expression by insulin.

scholarly journals Glioblastoma utilizes fatty acids and ketone bodies for growth allowing progression during ketogenic diet therapy

2019 ◽  
Author(s):  
Jantzen Sperry ◽  
Michael C. Condro ◽  
Lea Guo ◽  
Daniel Braas ◽  
Nathan Vanderveer-Harris ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Ketogenic Diet ◽  
Ketone Bodies ◽  
Aerobic Glycolysis ◽  
Diet Therapy ◽  
Acid Oxidation ◽  
Reduce Tumor Growth

SummaryGlioblastoma (GBM) metabolism has traditionally been characterized by a primary dependence on aerobic glycolysis, prompting the use of the ketogenic diet (KD) as a potential therapy. In this study we evaluated the effectiveness of the KD in GBM and assessed the role of fatty acid oxidation (FAO) in promoting GBM propagation. In vitro assays revealed FA utilization throughout the GBM metabolome, and growth inhibition in nearly every cell line in a broad spectrum of patient-derived glioma cells treated with FAO inhibitors. In vivo assessments revealed that knockdown of carnitine palmitoyltransferase 1A (CPT1A), the rate limiting enzyme for FAO, reduced the rate of tumor growth and increased survival. However, the unrestricted ketogenic diet did not reduce tumor growth, and for some models significantly reduced survival. Altogether, these data highlight important roles for FA and ketone body metabolism that could serve to improve targeted therapies in GBM.

THYROID STIMULATORS AND THYROID STIMULATION

1971 ◽  
Vol 66 (3) ◽  
pp. 558-576 ◽  
Author(s):  
Gerald Burke
Keyword(s):  
Regulatory System ◽  
Control Site ◽  
Thyroid Cell ◽  
Primary Control ◽  
Physico Chemical ◽  
Site Of Action ◽  
Long Acting

ABSTRACT A long-acting thyroid stimulator (LATS), distinct from pituitary thyrotrophin (TSH), is found in the serum of some patients with Graves' disease. Despite the marked physico-chemical and immunologic differences between the two stimulators, both in vivo and in vitro studies indicate that LATS and TSH act on the same thyroidal site(s) and that such stimulation does not require penetration of the thyroid cell. Although resorption of colloid and secretion of thyroid hormone are early responses to both TSH and LATS, available evidence reveals no basic metabolic pathway which must be activated by these hormones in order for iodination reactions to occur. Cyclic 3′, 5′-AMP appears to mediate TSH and LATS effects on iodination reactions but the role of this compound in activating thyroidal intermediary metabolism is less clear. Based on the evidence reviewed herein, it is suggested that the primary site of action of thyroid stimulators is at the cell membrane and that beyond the(se) primary control site(s), there exists a multifaceted regulatory system for thyroid hormonogenesis and cell growth.

scholarly journals Oncogenic lncRNA ZNF561-AS1 is essential for colorectal cancer proliferation and survival through regulation of miR-26a-3p/miR-128-5p-SRSF6 axis

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Zizhen Si ◽  
Lei Yu ◽  
Haoyu Jing ◽  
Lun Wu ◽  
Xidi Wang
Keyword(s):  
Colorectal Cancer ◽  
Rna Binding ◽  
Xenograft Model ◽  
Luciferase Reporter ◽  
Cancer Proliferation ◽  
Mouse Xenograft ◽  
Mouse Xenograft Model

Abstract Background Long non-coding RNAs (lncRNA) are reported to influence colorectal cancer (CRC) progression. Currently, the functions of the lncRNA ZNF561 antisense RNA 1 (ZNF561-AS1) in CRC are unknown. Methods ZNF561-AS1 and SRSF6 expression in CRC patient samples and CRC cell lines was evaluated through TCGA database analysis, western blot along with real-time PCR. SRSF6 expression in CRC cells was also examined upon ZNF561-AS1 depletion or overexpression. Interaction between miR-26a-3p, miR-128-5p, ZNF561-AS1, and SRSF6 was examined by dual luciferase reporter assay, as well as RNA binding protein immunoprecipitation (RIP) assay. Small interfering RNA (siRNA) mediated knockdown experiments were performed to assess the role of ZNF561-AS1 and SRSF6 in the proliferative actives and apoptosis rate of CRC cells. A mouse xenograft model was employed to assess tumor growth upon ZNF561-AS1 knockdown and SRSF6 rescue. Results We find that ZNF561-AS1 and SRSF6 were upregulated in CRC patient tissues. ZNF561-AS1 expression was reduced in tissues from treated CRC patients but upregulated in CRC tissues from relapsed patients. SRSF6 expression was suppressed and enhanced by ZNF561-AS1 depletion and overexpression, respectively. Mechanistically, ZNF561-AS1 regulated SRSF6 expression by sponging miR-26a-3p and miR-128-5p. ZNF561-AS1-miR-26a-3p/miR-128-5p-SRSF6 axis was required for CRC proliferation and survival. ZNF561-AS1 knockdown suppressed CRC cell proliferation and triggered apoptosis. ZNF561-AS1 depletion suppressed the growth of tumors in a model of a nude mouse xenograft. Similar observations were made upon SRSF6 depletion. SRSF6 overexpression reversed the inhibitory activities of ZNF561-AS1 in vivo, as well as in vitro. Conclusion In summary, we find that ZNF561-AS1 promotes CRC progression via the miR-26a-3p/miR-128-5p-SRSF6 axis. This study reveals new perspectives into the role of ZNF561-AS1 in CRC.

scholarly journals KLF7/VPS35 axis contributes to hepatocellular carcinoma progression through CCDC85C-activated β-catenin pathway

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yarong Guo ◽  
Bao Chai ◽  
Junmei Jia ◽  
Mudan Yang ◽  
Yanjun Li ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Proliferation ◽  
Tumor Growth ◽  
Luciferase Reporter ◽  
Aberrant Expression ◽  
Proliferation And Invasion ◽  
Hcc Cells

Abstract Objective Dysregulation of KLF7 participates in the development of various cancers, but it is unclear whether there is a link between HCC and aberrant expression of KLF7. The aim of this study was to investigate the role of KLF7 in proliferation and migration of hepatocellular carcinoma (HCC) cells. Methods CCK8, colony growth, transwell, cell cycle analysis and apoptosis detection were performed to explore the effect of KLF7, VPS35 and Ccdc85c on cell function in vitro. Xenografted tumor growth was used to assess in vivo role of KLF7. Chip-qPCR and luciferase reporter assays were applied to check whether KLF7 regulated VPS35 at transcriptional manner. Co-IP assay was performed to detect the interaction between VPS35 and Ccdc85c. Immunohistochemical staining and qRT-PCR analysis were performed in human HCC sampels to study the clinical significance of KLF7, VPS35 and β-catenin. Results Firstly, KLF7 was highly expressed in human HCC samples and correlated with patients’ differentiation and metastasis status. KLF7 overexpression contributed to cell proliferation and invasion of HCC cells in vitro and in vivo. KLF7 transcriptional activation of VPS35 was necessary for HCC tumor growth and metastasis. Further, co-IP studies revealed that VPS35 could interact with Ccdc85c in HCC cells. Rescue assay confirmed that overexpression of VPS35 and knockdown of Ccdc85c abolished the VPS35-medicated promotion effect on cell proliferation and invasion. Finally, KLF7/VPS35 axis regulated Ccdc85c, which involved in activation of β-catenin signaling pathway, confirmed using β-catenin inhibitor, GK974. Functional studies suggested that downregulation of Ccdc85c partly reversed the capacity of cell proliferation and invasion in HCC cells, which was regulated by VPS35 upregulation. Lastly, there was a positive correlation among KLF7, VPS35 and active-β-catenin in human HCC patients. Conclusion We demonstrated that KLF7/VPS35 axis promoted HCC cell progression by activating Ccdc85c-medicated β-catenin pathway. Targeting this signal axis might be a potential treatment strategy for HCC.

scholarly journals Let-7a regulates EV secretion and mitochondrial oxidative phosphorylation by targeting SNAP23 in colorectal cancer

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
You Dong Liu ◽  
Xiao Peng Zhuang ◽  
Dong Lan Cai ◽  
Can Cao ◽  
Qi Sheng Gu ◽  
...  
Keyword(s):  
Oxidative Phosphorylation ◽  
Metabolic Reprogramming ◽  
Luciferase Reporter ◽  
Mitochondrial Oxidative Phosphorylation ◽  
In Vivo Assays ◽  
Reporter Assays ◽  
Extracellular Mirna

Abstract Background MicroRNAs (miRNAs) are abundant in tumor-derived extracellular vesicles (EVs) and the functions of extracellular miRNA to recipient cells have been extensively studied with tumorigenesis. However, the role of miRNA in EV secretion from cancer cells remains unknown. Methods qPCR and bioinformatics analysis were applied for determining extracellular let-7a expression from CRC patient serum and cells. Nanosight particle tracking analysis was performed for investigating the effect of let-7a on EV secretion. Luciferase reporter assays was used for identifying targeted genes synaptosome-associated protein 23 (SNAP23). In vitro and in vivo assays were used for exploring the function of let-7a/SNAP23 axis in CRC progression. Bioenergetic assays were performed for investigating the role of let-7a/SNAP23 in cellular metabolic reprogramming. Results let-7a miRNA was elevated in serum EVs from CRC patients and was enriched in CRC cell-derived EVs. We determined that let-7a could suppress EV secretion directly targeting SNAP23. In turn, SNAP23 promotes EV secretion of let-7a to downregulate the intracellular let-7a expression. In addition, we found a novel mechanism of let-7a/SNAP23 axis by regulating mitochondrial oxidative phosphorylation (OXPHOS) through Lin28a/SDHA signaling pathway. Conclusions Let-7a plays an essential role in not only inhibiting EV secretion, but also suppressing OXPHOS through SNAP23, resulting in the suppression of CRC progression, suggesting that let-7a/SNAP23 axis could provide not only effective tumor biomarkers but also novel targets for tumor therapeutic strategies.

The use of siRNA as a pharmacological tool to assess a role for the transcription factor NF-IL6 in the brain under in vitro and in vivo conditions during LPS-induced inflammatory stimulation

2017 ◽  
Vol 28 (6) ◽  
Author(s):  
Jelena Damm ◽  
Joachim Roth ◽  
Rüdiger Gerstberger ◽  
Christoph Rummel
Keyword(s):  
Transcription Factor ◽  
Brain Cells ◽  
Nuclear Factor ◽  
Si Rna ◽  
The Brain ◽  
Deficient Mice ◽  
Transcription Factor Nuclear Factor

AbstractBackground:Studies with NF-IL6-deficient mice indicate that this transcription factor plays a dual role during systemic inflammation with pro- and anti-inflammatory capacities. Here, we aimed to characterize the role of NF-IL6 specifically within the brain.Methods:In this study, we tested the capacity of short interfering (si) RNA to silence the inflammatory transcription factor nuclear factor-interleukin 6 (NF-IL6) in brain cells underResults:In cells of a mixed neuronal and glial primary culture from the ratConclusions:This approach was, thus, not suitable to characterize the role NF-IL6 in the brain

scholarly journals Has-miR-875-5p Inhibits Tumorigenesis by Targeting USF2 via TGF-β Signaling Pathway in Gastric Cancer

2021 ◽  
Author(s):  
Shenshuo Gao ◽  
Zhikai Zhang ◽  
Xubin Wang ◽  
Yan Ma ◽  
Chensheng Li ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Signaling Pathway ◽  
Research Direction ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Gastric Cancer Cells ◽  
New Research

Abstract Background: Gastric cancer (GC) is one of the most common malignancies, and more and more evdiences show that the pathogenesis is regulated by various miRNAs.In this study, we investigated the role of miR-875 in GC. Methods:The expression of miR-875-5p was detected in human GC specimens and cell lines by miRNA RT-PCR. The effect of miR-875-5p on GC proliferation was determined by CCK-8 proliferation assay and EDU assay. Migration and invasion were examined by transwell migration and invasion assay and wound healing assay. The interaction between miR-875-5p and its target gene USF2 was verified by a dual luciferase reporter assay. The effects of miR-875-5p in vivo were studied in xenograft nude mice models.Related proteins were detected by Western blot.Results:The results showed that miR-875-5p inhibited the proliferation, migration and invasion of gastric cancer cells in vitro, and inhibited tumorigenesis in vivo. USF2 proved to be a direct target of miR-875-5p. Knockdown of USF2 partially counteracts the effects of miR-875-5p inhibitors.Overexpression of miR-875-5p can inhibit proliferation, migration, and invasion through the TGF-β signaling pathway by down-regulation of USF2 in GC, providing a new research direction for the diagnosis and targeted therapy of GC.Conclusions: MiR-875-5pcan inhibited the progression of GC by directly targeting USF2 and negatively regulating TGF-β signaling pathway.In the future, miR-875-5p is expected to be used as a potential therapeutic target for GC therapy.

scholarly journals MiR-22-3p suppresses sepsis-induced acute kidney injury by targeting PTEN

2020 ◽  
Vol 40 (6) ◽  
Author(s):  
Xudong Wang ◽  
Yali Wang ◽  
Mingjian Kong ◽  
Jianping Yang
Keyword(s):  
Acute Kidney Injury ◽  
Inflammatory Response ◽  
Periodic Acid ◽  
Kidney Injury ◽  
Luciferase Reporter ◽  
Tunel Staining ◽  
Tnf Α

Abstract Background: Septic acute kidney injury is considered as a severe and frequent complication that occurs during sepsis. The present study was performed to understand the role of miR-22-3p and its underlying mechanism in sepsis-induced acute kidney injury. Methods: Rats were injected with adenovirus carrying miR-22-3p or miR-NC in the caudal vein before cecal ligation. Meanwhile, HK-2 cells were transfected with the above adenovirus following LPS stimulation. We measured the markers of renal injury (blood urea nitrogen (BUN), serum creatinine (SCR)). Histological changes in kidney tissues were examined by hematoxylin and eosin (H&E), Masson staining, periodic acid Schiff staining and TUNEL staining. The levels of IL-1β, IL-6, TNF-α and NO were determined by ELISA assay. Using TargetScan prediction and luciferase reporter assay, we predicted and validated the association between PTEN and miR-22-3p. Results: Our data showed that miR-22-3p was significantly down-regulated in a rat model of sepsis-induced acute kidney injury, in vivo and LPS-induced sepsis model in HK-2 cells, in vitro. Overexpression of miR-22-3p remarkably suppressed the inflammatory response and apoptosis via down-regulating HMGB1, p-p65, TLR4 and pro-inflammatory factors (IL-1β, IL-6, TNF-α and NO), both in vivo and in vitro. Moreover, PTEN was identified as a target of miR-22-3p. Furthermore, PTEN knockdown augmented, while overexpression reversed the suppressive role of miR-22-3p in LPS-induced inflammatory response. Conclusions: Our results showed that miR-22-3p induced protective role in sepsis-induced acute kidney injury may rely on the repression of PTEN.

scholarly journals LINC01006 facilitates cell proliferation, migration and invasion in prostate cancer through targeting miR-34a-5p to up-regulate DAAM1

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Enhui Ma ◽  
Qianqian Wang ◽  
Jinhua Li ◽  
Xinqi Zhang ◽  
Zhenjia Guo ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Prostate Gland ◽  
Inhibitory Effect ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Protein Coding ◽  
Novel Target

Abstract Background Prostate cancer (PCa) is a kind of malignancy occurring in the prostate gland. Substantial researches have proved the major role of long noncoding RNAs (lncRNAs) in PCa. However, the role of long intergenic non-protein coding RNA 1006 (LINC01006) in PCa has not been investigated yet. Methods RT-qPCR was used to examine the expression levels of LINC01006 and its downstream targets. The function of LINC01006 in PCa was tested by in vitro and in vivo assays. With application of RNA pull down, RNA immunoprecipitation (RIP) and luciferase reporter assays, the interaction among LINC01006, miR-34a-5p and disheveled associated activator of morphogenesis 1 (DAAM1) were verified. Results LINC01006 expression presented high in PCa cell lines. LINC01006 silencing suppressed cell proliferative, migratory, invasive capacities while accelerated apoptotic rate. Besides, LINC01006 knockdown also suppressed tumor growth and metastasis in vivo. Furthermore, miR-34a-5p, a tumor suppressor in PCa, was sponged by LINC01006. Moreover, DAAM1 was targeted by miR-34a-5p and promoted PCa progression. More intriguingly, rescue assays suggested that the inhibitory effect of LINC01006 knockdown on PCa development was offset by DAAM1 overexpression. Conclusions LINC01006 promoted PCa progression by sponging miR-34a-5p to up-regulate DAAM1, providing a novel target for PCa therapy.

scholarly journals Role of miR-148a in Mitigating Hepatic Ischemia-Reperfusion Injury by Repressing the TLR4 Signaling Pathway via Targeting CaMKIIα in Vivo and in Vitro

2018 ◽  
Vol 49 (5) ◽  
pp. 2060-2072 ◽  
Author(s):  
Daofeng Zheng ◽  
Zhongtang Li ◽  
Xufu Wei ◽  
Rui Liu ◽  
Ai Shen ◽  
...  
Keyword(s):  
Liver Dysfunction ◽  
Ischemia Reperfusion ◽  
Inflammatory Factors ◽  
Luciferase Reporter ◽  
Hepatic Ischemia ◽  
Tlr4 Signaling ◽  
Hepatic Ischemia Reperfusion

Background/Aims: Hepatic ischemia-reperfusion (I/R) injury, which is mainly induced by inflammation and unstable intracellular ions, is a major negative consequence of surgery that compromises hepatic function. However, the exact mechanisms of liver I/R injury have not been determined. Positive crosstalk with the Ca2+/CaMKII pathway is required for complete activation of the TLR4 pathway and inflammation. We previously found that miR-148a, which decreased in abundance with increasing reperfusion time, targeted and repressed the expression of CaMKIIα. In the present study, we examined the role of the miR-148a machinery in I/R-induced Ca2+/CaMKII and TLR4 signaling changes, inflammation, and liver dysfunction in vivo and in vitro. Methods: Liver function was evaluated by serum aminotransferase levels and hematoxylin-eosin (HE) staining. Inflammatory factors were detected by enzyme-linked immunosorbent assay. Gene and protein expression were assessed by RT-PCR and western blot. Small interfering RNA was used to silence target gene expression. HE staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling were used to measure hepatic tissue apoptosis. These assays were performed to identify factors upregulated in hepatic I/R injury and downregulated by miR-148a. Results: We manifested that expression of CaMKIIα and phosphorylation of TAK1 and IRF3 were elevated in hypoxia/reoxygenation (H/R)-treated primary Kupffer cells (KCs) and liver tissue of I/R-treated mice, but these effects were attenuated by treatment with miR-148a mimic and were accompanied by the alleviation of liver dysfunction and hepatocellular apoptosis. Luciferase reporter experiments showed that miR148a suppressed luciferase activity by almost 60%. Moreover, knockdown of CaMKIIα in H/R KCs led to significant deficiencies in p-TAK1, P-IRF3, IL-6, and TNF-α, which was consistent with the effects of miR-148a overexpression. Otherwise, the same trend of activation of TAK1 and IRF3 and inflammatory factors in vitro was observed in the siTAK1 + siIRF3 group compared with the siCaMKIIα group. Conclusion: Taken together, we conclude that miR-148a may mitigate hepatic I/R injury by ameliorating TLR4-mediated inflammation via targeting CaMKIIα in vitro and in vivo.

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