scholarly journals Longitudinal noninvasive monitoring of transcription factor activation in cardiovascular regulatory nuclei using bioluminescence imaging

2008 ◽  
Vol 33 (2) ◽  
pp. 292-299 ◽  
Author(s):  
Jeffrey R. Peterson ◽  
David W. Infanger ◽  
Valdir A. Braga ◽  
Yulong Zhang ◽  
Ram V. Sharma ◽  
...  

The ability to monitor transcription factor (TF) activation in the central nervous system (CNS) has the potential to provide novel information regarding the molecular mechanisms underlying a wide range of neurobiological processes. However, traditional biochemical assays limit the mapping of TF activity to select time points. In vivo bioluminescence imaging (BLI) has emerged as an attractive technology for visualizing internal molecular events in the same animal over time. Here, we evaluated the utility of BLI, in combination with virally mediated delivery of reporter constructs to cardiovascular nuclei, for monitoring of TF activity in these discrete brain regions. Following viral gene transfer of NF-κB-driven luciferase reporter to the subfornical organ (SFO), BLI enabled daily measurements of baseline TF activity in the same animal for 1 mo. Importantly, systemic endotoxin, a stimulator of NF-κB activity, induced dramatic and dose-dependent increases in NF-κB-dependent bioluminescence in the SFO up to 30 days after gene transfer. Cotreatment with a dominant-negative IκBα mutant significantly prevented endotoxin-dependent NF-κB activation, confirming the specificity of the bioluminescence signal. NF-κB-dependent luminescence signals were also stable and inducible 1 mo following delivery of luciferase reporter construct to the paraventricular nucleus or rostral ventrolateral medulla. Lastly, using targeted adenoviral delivery of an AP-1 responsive luciferase reporter, we showed similar baseline and endotoxin-induced AP-1 activity in these same brain regions as with NF-κB reporters. These results demonstrate that BLI, in combination with virally mediated gene transfer, is a powerful method for longitudinal monitoring and quantification of TF activity in targeted CNS nuclei in vivo.

2021 ◽  
Vol 11 ◽  
Author(s):  
Zhuozhen Lyu ◽  
Mingyu Yang ◽  
Tan Yang ◽  
Mingze Ma ◽  
Zhen Yang

Metal-regulatory transcription factor-1 (MTF-1) is of importance in maintaining metal homeostasis. Copper exposure considerably stimulates the proliferation of hepatocellular carcinoma (HCC) cells with enhanced MTF-1 expression. However, the underlying molecular mechanisms have not been completely elucidated. In this study, we utilized different approaches to investigate the potential role of MTF-1 involved in HCC progression. The expression levels of MTF-1 and miR-148a-3p were determined using real-time polymerase chain reaction (PCR), Western blotting, and immunohistochemistry. The interaction of MTF-1 with apurinic apyrimidinic endonuclease/redox effector factor 1 (APE/Ref-1) or miR-148a-3p was determined using immunoprecipitation or dual-luciferase reporter assay, respectively. Cell viability and metastatic ability were evaluated using colony formation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), wound scratch, and Transwell assays, and apoptotic cells were detected by flow cytometry. The biological functions of MTF-1 and miR-148a-3p were also determined using a xenograft mouse model. MTF-1 expression was upregulated in HCC cells and was associated with poor survival and recurrence. MTF-1 overexpression enhanced the proliferation and metastatic potential of HCC cells. Further mechanistic analyses demonstrated that MTF-1 bound to APE/Ref-1 and that MTF-1 is a direct target of miR-148-3p, which inversely regulated MTF-1 transcription activity. MiR-148a-3p overexpression effectively inhibited HCC cell proliferation and metastasis stimulated by MTF-1, with increased apoptosis. There was a decrease in miR-148a-3p expression in exosomes isolated from the plasma of patients with HCC and HCC cell culture supernatants. Co-incubation of HCC cells with exosomes from hepatocyte-conditioned media inhibited cell migration and caused apoptosis. The in vivo study revealed slow growth of MTF-1-knockdown and miR-148a-3p-overexpressing Hep3B-derived xenografts, with reduced tumor volume and weight compared with the control group. Collectively, these findings implicate MTF-1 as a modulator of HCC tumorigenesis and progression. Selective targeting towards exosomal miR-148a-3p, which might contribute to the negative regulation of MTF-1 at least partially in HCC, demonstrates therapeutic benefits for patients with HCC.


2020 ◽  
Vol 19 (1) ◽  
Author(s):  
You Shuai ◽  
Zhonghua Ma ◽  
Weitao Liu ◽  
Tao Yu ◽  
Changsheng Yan ◽  
...  

Abstract Background Gastric cancer (GC) is the third leading cause of cancer-related mortality globally. Long noncoding RNAs (lncRNAs) are dysregulated in obvious malignancies including GC and exploring the regulatory mechanisms underlying their expression is an attractive research area. However, these molecular mechanisms require further clarification, especially upstream mechanisms. Methods LncRNA MNX1-AS1 expression in GC tissue samples was investigated via microarray analysis and further determined in a cohort of GC tissues via quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays. Cell proliferation and flow cytometry assays were performed to confirm the roles of MNX1-AS1 in GC proliferation, cell cycle regulation, and apoptosis. The influence of MNX1-AS1 on GC cell migration and invasion was explored with Transwell assays. A xenograft tumour model was established to verify the effects of MNX1-AS1 on in vivo tumourigenesis. The TEAD4-involved upstream regulatory mechanism of MNX1-AS1 was explored through ChIP and luciferase reporter assays. The mechanistic model of MNX1-AS1 in regulating gene expression was further detected by subcellular fractionation, FISH, RIP, ChIP and luciferase reporter assays. Results It was found that MNX1-AS1 displayed obvious upregulation in GC tissue samples and cell lines, and ectopic expression of MNX1-AS1 predicted poor clinical outcomes for patients with GC. Overexpressed MNX1-AS1 expression promoted proliferation, migration and invasion of GC cells markedly, whereas decreased MNX1-AS1 expression elicited the opposite effects. Consistent with the in vitro results, MNX1-AS1 depletion effectively inhibited the growth of xenograft tumour in vivo. Mechanistically, TEAD4 directly bound the promoter region of MNX1-AS1 and stimulated the transcription of MNX1-AS1. Furthermore, MNX1-AS1 can sponge miR-6785-5p to upregulate the expression of BCL2 in GC cells. Meanwhile, MNX1-AS1 suppressed the transcription of BTG2 by recruiting polycomb repressive complex 2 to BTG2 promoter regions. Conclusions Our findings demonstrate that MNX1-AS1 may be able to serve as a prognostic indicator in GC patients and that TEAD4-activatd MNX1-AS1 can promote GC progression through EZH2/BTG2 and miR-6785-5p/BCL2 axes, implicating it as a novel and potent target for the treatment of GC.


2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Chao Liu ◽  
An-Song Liu ◽  
Da Zhong ◽  
Cheng-Gong Wang ◽  
Mi Yu ◽  
...  

AbstractBone marrow-derived mesenchymal stem cells (BM-MSCs), the common progenitor cells of adipocytes and osteoblasts, have been recognized as the key mediator during bone formation. Herein, our study aim to investigate molecular mechanisms underlying circular RNA (circRNA) AFF4 (circ_AFF4)-regulated BM-MSCs osteogenesis. BM-MSCs were characterized by FACS, ARS, and ALP staining. Expression patterns of circ_AFF4, miR-135a-5p, FNDC5/Irisin, SMAD1/5, and osteogenesis markers, including ALP, BMP4, RUNX2, Spp1, and Colla1 were detected by qRT-PCR, western blot, or immunofluorescence staining, respectively. Interactions between circ_AFF4 and miR-135a-5p, FNDC5, and miR-135a-5p were analyzed using web tools including TargetScan, miRanda, and miRDB, and further confirmed by luciferase reporter assay and RNA pull-down. Complex formation between Irisin and Integrin αV was verified by Co-immunoprecipitation. To further verify the functional role of circ_AFF4 in vivo during bone formation, we conducted animal experiments harboring circ_AFF4 knockdown, and born samples were evaluated by immunohistochemistry, hematoxylin and eosin, and Masson staining. Circ_AFF4 was upregulated upon osteogenic differentiation induction in BM-MSCs, and miR-135a-5p expression declined as differentiation proceeds. Circ_AFF4 knockdown significantly inhibited osteogenesis potential in BM-MSCs. Circ_AFF4 stimulated FNDC5/Irisin expression through complementary binding to its downstream target molecule miR-135a-5p. Irisin formed an intermolecular complex with Integrin αV and activated the SMAD1/5 pathway during osteogenic differentiation. Our work revealed that circ_AFF4, acting as a sponge of miR-135a-5p, triggers the promotion of FNDC5/Irisin via activating the SMAD1/5 pathway to induce osteogenic differentiation in BM-MSCs. These findings gained a deeper insight into the circRNA-miRNA regulatory system in the bone marrow microenvironment and may improve our understanding of bone formation-related diseases at physiological and pathological levels.


2020 ◽  
Vol 11 (10) ◽  
Author(s):  
Chenguang Ding ◽  
Xiaoming Ding ◽  
Jin Zheng ◽  
Bo Wang ◽  
Yang Li ◽  
...  

Abstract Renal tubular cell death is the key factor of the pathogenesis of ischemia/reperfusion (I/R) kidney injury. Ferroptosis is a type of regulated cell death (RCD) found in various diseases. However, the underlying molecular mechanisms related to ferroptosis in renal I/R injury remain unclear. In the present study, we investigated the regulatory role of microRNAs on ferroptosis in I/R-induced renal injury. We established the I/R-induced renal injury model in rats, and H/R induced HK-2 cells injury in vitro. CCK-8 was used to measure cell viability. Fe2+ and ROS levels were assayed to evaluate the activation of ferroptosis. We performed RNA sequencing to profile the miRNAs expression in H/R-induced injury and ferroptosis. Western blot analysis was used to detect the protein expression. qRT-PCR was used to detect the mRNA and miRNA levels in cells and tissues. We further used luciferase reporter assay to verify the direct targeting effect of miRNA. We found that ischemia/reperfusion-induced ferroptosis in rat’s kidney. We identified that miR-182-5p and miR-378a-3p were upregulated in the ferroptosis and H/R-induced injury, and correlates reversely with glutathione peroxidases 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11) expression in renal I/R injury tissues, respectively. In vitro studies showed that miR-182-5p and miR-378a-3p induced ferroptosis in cells. We further found that miR-182-5p and miR-378a-3p regulated the expression of GPX4 and SLC7A11 negatively by directly binding to the 3′UTR of GPX4 and SLC7A11 mRNA. In vivo study showed that silencing miR-182-5p and miR-378a-3p alleviated the I/R-induced renal injury in rats. In conclusion, we demonstrated that I/R induced upregulation of miR-182-5p and miR-378a-3p, leading to activation of ferroptosis in renal injury through downregulation of GPX4 and SLC7A11.


2020 ◽  
Vol 11 (9) ◽  
Author(s):  
Olivia J. Marola ◽  
Stephanie B. Syc-Mazurek ◽  
Gareth R. Howell ◽  
Richard T. Libby

Abstract Glaucoma is a neurodegenerative disease characterized by loss of retinal ganglion cells (RGCs), the output neurons of the retina. Multiple lines of evidence show the endothelin (EDN, also known as ET) system is important in glaucomatous neurodegeneration. To date, the molecular mechanisms within RGCs driving EDN-induced RGC death have not been clarified. The pro-apoptotic transcription factor JUN (the canonical target of JNK signaling) and the endoplasmic reticulum stress effector and transcription factor DNA damage inducible transcript 3 (DDIT3, also known as CHOP) have been shown to act downstream of EDN receptors. Previous studies demonstrated that JUN and DDIT3 were important regulators of RGC death after glaucoma-relevant injures. Here, we characterized EDN insult in vivo and investigated the role of JUN and DDIT3 in EDN-induced RGC death. To accomplish this, EDN1 ligand was intravitreally injected into the eyes of wildtype, Six3-cre+Junfl/fl (Jun−/−), Ddit3 null (Ddit3−/−), and Ddit3−/−Jun−/− mice. Intravitreal EDN1 was sufficient to drive RGC death in vivo. EDN1 insult caused JUN activation in RGCs, and deletion of Jun from the neural retina attenuated RGC death after EDN insult. However, deletion of Ddit3 did not confer significant protection to RGCs after EDN1 insult. These results indicate that EDN caused RGC death via a JUN-dependent mechanism. In addition, EDN signaling is known to elicit potent vasoconstriction. JUN signaling was shown to drive neuronal death after ischemic insult. Therefore, the effects of intravitreal EDN1 on retinal vessel diameter and hypoxia were explored. Intravitreal EDN1 caused transient retinal vasoconstriction and regions of RGC and Müller glia hypoxia. Thus, it remains a possibility that EDN elicits a hypoxic insult to RGCs, causing apoptosis via JNK-JUN signaling. The importance of EDN-induced vasoconstriction and hypoxia in causing RGC death after EDN insult and in models of glaucoma requires further investigation.


2018 ◽  
Vol 51 (1) ◽  
pp. 113-128 ◽  
Author(s):  
Jia Zhu ◽  
Rui Zhang ◽  
Dongxiang Yang ◽  
Jibin Li ◽  
Xiaofei Yan ◽  
...  

Background/Aims: Doxorubicin (DOX) is a widely used chemotherapeutic agent for colorectal cancer (CRC). However, the acquirement of DOX resistance limits its clinical application for cancer therapy. Mounting evidence has suggested that aberrantly expressed lncRNAs contribute to drug resistance of various tumors. Our study aimed to explore the role and molecular mechanisms of lncRNA X-inactive specific transcript (XIST) in chemoresistance of CRC to DOX. Methods: The expressions of XIST, miR-124, serum and glucocorticoid-inducible kinase 1 (SGK1) mRNA in DOX-resistant CRC tissues and cells were detected by qRT-PCR or western blot analysis. DOX sensitivity was assessed by detecting IC50 value of DOX, the protein levels of P-glycoprotein (P-gp) and glutathione S-transferase-π (GST-π) and apoptosis. The interactions between XIST, miR-124 and SGK1 were confirmed by luciferase reporter assay, qRT-PCR and western blot. Xenograft tumor assay was used to verify the role of XIST in DOX resistance in CRC in vivo. Results: XIST expression was upregulated and miR-124 expression was downregulated in DOX-resistant CRC tissues and cells. Knockdown of XIST inhibited DOX resistance of CRC cells, as evidenced by the reduced IC50 value of DOX, decreased P-gp and GST-π levels and enhanced apoptosis in XIST-silenced DOX-resistant CRC cells. Additionally, XIST positively regulated SGK1 expression by interacting with miR-124 in DOX-resistant CRC cells. miR-124 suppression strikingly reversed XIST-knockdown-mediated repression on DOX resistance in DOX-resistant CRC cells. Moreover, SGK1-depletion-elicited decrease of DOX resistance was greatly restored by XIST overexpression or miR-124 inhibition in DOX-resistant CRC cells. Furthermore, XIST knockdown enhanced the anti-tumor effect of DOX in CRC in vivo. Conclusion: XIST exerted regulatory function in resistance of DOX possibly through miR-124/SGK1 axis, shedding new light on developing promising therapeutic strategy to overcome chemoresistance in CRC patients.


Gene Therapy ◽  
2006 ◽  
Vol 13 (21) ◽  
pp. 1545-1552 ◽  
Author(s):  
S Xenariou ◽  
U Griesenbach ◽  
S Ferrari ◽  
P Dean ◽  
R K Scheule ◽  
...  

Author(s):  
Ya-Ping Xu ◽  
Ze-Ning Dong ◽  
Si-Wei Wang ◽  
Yi-Min Zheng ◽  
Chi Zhang ◽  
...  

Abstract Background Accumulating evidence indicates that circRNAs may serve as essential regulators in the progression of several human cancers, but the function and mechanism of circRNAs in intrahepatic cholangiocarcinoma (ICC) are largely unknown. Methods RNA-seq was used to assess differentially expressed circRNAs between 4 ICC and peritumor tissues. Quantitative RT-PCR and in situ hybridization were used to determine the circHMGCS1–016 expression in ICC tissues. The function and mechanism of circHMGCS1–016 were further identified via in vivo experiments. The clinical characteristics and prognostic significance of circHMGCS1–016 were analyzed by a retrospective study. The functions of circHMGCS1–016 were assessed via modifying circRNA expression in ICC cells. Moreover, the molecular mechanisms of circHMGCS1–016 in ICC cells were explored by circRNA precipitation, miRNA immunoprecipitation, SILAC and luciferase reporter assays. Results We identified that compared with peritumor tissues, ICC tissues expressed hsa_circ_0008621 (circHMGCS1–016) high by RNA-seq, which was further identified by qRT-PCR and in situ hybridization. Moreover, the expression of circHMGCS1–016 was revealed to be associated with survival and recurrence of ICC patients. By regulating circHMGCS1–016 expression, we found that elevated circHMGCS1–016 promoted ICC development both in vitro and in vivo. By SILAC and circRNA-pull down, we demonstrated that circHMGCS1–016 induced ICC cell invasion and reshaped the tumor immune microenvironment via the miR-1236-3p/CD73 and GAL-8 axis. In ICC tissues, we uncovered that a high level of circHMGCS1–016 was positively associated with CD73 and GAL-8 expression and negatively related to the CD8+ T cells infiltration, which was further validated by establishing a humanized mouse tumor model. Importantly, we displayed that ICC patients with high levels of circHMGCS1–016 in tumor tissues benefited less from anti-PD1 treatment compared to those with low levels of circHMGCS1–016. Conclusions CircHMGCS1–016 is a forceful contributor in ICC development and immune tolerance via miR-1236-3p/CD73 and GAL-8 axis. CircHMGCS1–016 can be explored as a new potential biomarker and therapeutic target for PD1-resistant ICC.


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