scholarly journals Nogo-B Receptor Directs Mitochondria-Associated Membranes to Regulate Vascular Smooth Muscle Cell Proliferation

2019 ◽  
Vol 20 (9) ◽  
pp. 2319
Author(s):  
Yi-Dong Yang ◽  
Man-Man Li ◽  
Gang Xu ◽  
Lan Feng ◽  
Er-Long Zhang ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Nuclear Localization ◽  
Epithelial Mesenchymal Transition ◽  
Pulmonary Arteries ◽  
Underlying Mechanism ◽  
Mesenchymal Transition ◽  
Vsmc Proliferation ◽  
Vsmcs Proliferation

Mitochondria-associated membranes (MAM) are a well-recognized contact link between the mitochondria and endoplasmic reticulum that affects mitochondrial biology and vascular smooth muscle cells (VSMCs) proliferation via the regulation of mitochondrial Ca2+(Ca2+m) influx. Nogo-B receptor (NgBR) plays a vital role in proliferation, epithelial-mesenchymal transition, and chemoresistance of some tumors. Recent studies have revealed that downregulation of NgBR, which stimulates the proliferation of VSMCs, but the underlying mechanism remains unclear. Here, we investigated the role of NgBR in MAM and VSMC proliferation. We analyzed the expression of NgBR in pulmonary arteries using a rat model of hypoxic pulmonary hypertension (HPH), in which rats were subjected to normoxic recovery after hypoxia. VSMCs exposed to hypoxia and renormoxia were used to assess the alterations in NgBR expression in vitro. The effect of NgBR downregulation and overexpression on VSMC proliferation was explored. The results revealed that NgBR expression was negatively related with VSMCs proliferation. Then, MAM formation and the phosphorylation of inositol 1,4,5-trisphosphate receptor type 3 (IP3R3) was detected. We found that knockdown of NgBR resulted in MAM disruption and augmented the phosphorylation of IP3R3 through pAkt, accompanied by mitochondrial dysfunction including decreased Ca2+m, respiration and mitochondrial superoxide, increased mitochondrial membrane potential and HIF-1α nuclear localization, which were determined by confocal microscopy and Seahorse XF-96 analyzer. By contrast, NgBR overexpression attenuated IP3R3 phosphorylation and HIF-1α nuclear localization under hypoxia. These results reveal that dysregulation of NgBR promotes VSMC proliferation via MAM disruption and increased IP3R3 phosphorylation, which contribute to the decrease of Ca2+m and mitochondrial impairment.

scholarly journals Geranylgeranyl Transferase-I Knockout Inhibits Oxidative Injury of Vascular Smooth Muscle Cells and Attenuates Diabetes-Accelerated Atherosclerosis

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Guo-Ping Chen ◽  
Jian Yang ◽  
Guo-Feng Qian ◽  
Wei-Wei Xu ◽  
Xiao-Qin Zhang
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
High Glucose ◽  
Oxidative Injury ◽  
Accelerated Atherosclerosis ◽  
Vsmc Proliferation ◽  
Geranylgeranyl Transferase

The proliferation of vascular smooth muscle cells (VSMCs) induced by oxidative injury is one of the main features in diabetes-accelerated atherosclerosis. Geranylgeranyl transferase-I (GGTase-I) is an essential enzyme mediating posttranslational modification, especially the geranylgeranylation of small GTPase, Rac1. Our previous studies found that GGTase-I played an important role in diabetes-accelerated atherosclerosis. However, its exact role is largely unclear. In this study, mouse conditional knockout of VSMC GGTase-I (Pggt1bΔ/Δ mice) was generated using the CRISPR/Cas9 system. The mouse model of diabetes-accelerated atherosclerosis was induced by streptozotocin injections and an atherogenic diet. We found that GGTase-I knockout attenuated diabetes-accelerated atherosclerosis in vivo and suppressed high-glucose-induced VSMC proliferation in vitro. Moreover, after a 16-week duration of diabetes, Pggt1bΔ/Δ mice exhibited lower α-smooth muscle actin (α-SMA) and nitrotyrosine level, Rac1 activity, p47phox and NOXO1 expression, and phospho-ERK1/2 and phosphor-JNK content than wild-type mice. Meanwhile, the same changes were found in Pggt1bΔ/Δ VSMCs cultured with high glucose (22.2 mM) in vitro. In conclusion, GGTase-I knockout efficiently blocked diabetes-accelerated atherosclerosis, and this protective effect must be related to the inhibition of VSMC proliferation. The potential mechanisms probably involved interfering Rac1 geranylgeranylation, inhibiting the assembly of NADPH oxidase cytosolic regulatory subunits, reducing oxidative injury, and decreasing ERK1/2 and JNK phosphorylation.

scholarly journals Armadillo Repeat-Containing Protein 8 (ARMC8) Silencing Inhibits Proliferation and Invasion in Osteosarcoma Cells

2016 ◽  
Vol 24 (5) ◽  
pp. 381-389 ◽  
Author(s):  
Feng Jiang ◽  
Yan Shi ◽  
Hong Lu ◽  
Guojun Li
Keyword(s):  
Epithelial Mesenchymal Transition ◽  
Underlying Mechanism ◽  
Migration And Invasion ◽  
Osteosarcoma Cell ◽  
Osteosarcoma Cells ◽  
Mesenchymal Transition ◽  
Armadillo Repeat ◽  
Proliferation And Invasion

Armadillo repeat-containing protein 8 (ARMC8) plays an important role in regulating cell migration, proliferation, tissue maintenance, signal transduction, and tumorigenesis. However, the expression pattern and role of ARMC8 in osteosarcoma are still unclear. In this study, our aims were to examine the effects of ARMC8 on osteosarcoma and to explore its underlying mechanism. Our results demonstrated that ARMC8 was overexpressed in osteosarcoma cell lines. Knockdown of ARMC8 significantly inhibited osteosarcoma cell proliferation in vitro and markedly inhibited xenograft tumor growth in vivo. ARMC8 silencing also suppressed the epithelial‐mesenchymal transition (EMT) phenotype, as well as inhibited the migration and invasion of osteosarcoma cells. Furthermore, knockdown of ARMC8 obviously inhibited the expression of β-catenin, c-Myc, and cyclin D1 in MG-63 cells. In conclusion, this report demonstrates that ARMC8 silencing inhibits proliferation and invasion of osteosarcoma cells. Therefore, ARMC8 may play an important role in the development and progression of human osteosarcoma and may represent a novel therapeutic target in the treatment of osteosarcoma.

scholarly journals HCK promotes glioblastoma progression by TGFβ signaling

2020 ◽  
Vol 40 (6) ◽  
Author(s):  
Zhenlin Wang ◽  
Chenting Ying ◽  
Anke Zhang ◽  
Houshi Xu ◽  
Yang Jiang ◽  
...  
Keyword(s):  
Tyrosine Kinases ◽  
B Lymphocyte ◽  
Epithelial Mesenchymal Transition ◽  
Enrichment Analysis ◽  
Underlying Mechanism ◽  
Gene Set Enrichment Analysis ◽  
Tgfβ Signaling ◽  
Mesenchymal Transition

Abstract The hematopoietic cell kinase (HCK), a member of the Src family protein-tyrosine kinases (SFKs), is primarily expressed in cells of the myeloid and B lymphocyte lineages. Nevertheless, the roles of HCK in glioblastoma (GBM) remain to be examined. Thus, we aimed to investigate the effects of HCK on GBM development both in vitro and in vivo, as well as the underlying mechanism. The present study found that HCK was highly expressed in both tumor tissues from patients with GBM and cancer cell lines. HCK enhanced cell viability, proliferation, and migration, and induced cell apoptosis in vitro. Tumor xenografts results also demonstrated that HCK knockdown significantly inhibited tumor growth. Interestingly, gene set enrichment analysis (GSEA) showed HCK was closed associated with epithelial mesenchymal transition (EMT) and TGFβ signaling in GBM. In addition, we also found that HCK accentuates TGFβ-induced EMT, suggesting silencing HCK inhibited EMT through the inactivation of Smad signaling pathway. In conclusion, our findings indicated that HCK is involved in GBM progression via mediating EMT process, and may be served as a promising therapeutic target for GBM.

scholarly journals Arctigenin Suppressed Epithelial-Mesenchymal Transition Through Wnt3a/β-Catenin Pathway in PQ-Induced Pulmonary Fibrosis

2020 ◽  
Vol 11 ◽  
Author(s):  
Fei Gao ◽  
Yun Zhang ◽  
Zhizhou Yang ◽  
Mengmeng Wang ◽  
Zhiyi Zhou ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Signaling Pathway ◽  
Lung Fibrosis ◽  
Epithelial Mesenchymal Transition ◽  
A549 Cells ◽  
Underlying Mechanism ◽  
Alveolar Type ◽  
Mesenchymal Transition

Arctigenin (ATG), a major bioactive substance of Fructus Arctii, counters renal fibrosis; however, whether it protects against paraquat (PQ)-induced lung fibrosis remains unknown. The present study was to determine the effect of ATG on PQ-induced lung fibrosis in a mouse model and the underlying mechanism. Firstly, we found that ATG suppressed PQ-induced pulmonary fibrosis by blocking the epithelial-mesenchymal transition (EMT). ATG reduced the expressions of Vimentin and α-SMA (lung fibrosis markers) induced by PQ and restored the expressions of E-cadherin and Occludin (two epithelial markers) in vivo and in vitro. Besides, the Wnt3a/β-catenin signaling pathway was significantly activated in PQ induced pulmonary fibrosis. Further analysis showed that pretreatment of ATG profoundly abrogated PQ-induced EMT-like phenotypes and behaviors in A549 cells. The Wnt3a/β-catenin signaling pathway was repressed by ATG treatment. The overexpression of Wnt3a could weaken the therapeutic effect of ATG in A549 cells. These findings suggested that ATG could serve as a new therapeutic candidate to inhibit or even reverse EMT-like changes in alveolar type II cells during PQ-induced lung fibrosis, and unraveled that the Wnt3a/β-catenin pathway might be a mechanistic tool for ATG to control pulmonary fibrosis.

scholarly journals TXNDC12 promotes EMT and metastasis of hepatocellular carcinoma cells via activation of β-catenin

2019 ◽  
Vol 27 (4) ◽  
pp. 1355-1368 ◽  
Author(s):  
Kefei Yuan ◽  
Kunlin Xie ◽  
Tian Lan ◽  
Lin Xu ◽  
Xiangzheng Chen ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Nuclear Translocation ◽  
Epithelial Mesenchymal Transition ◽  
Disease Free Survival ◽  
Underlying Mechanism ◽  
Carcinoma Cells ◽  
Mesenchymal Transition ◽  
Protein Protein Interaction

Abstract Metastasis is one of the main contributors to the poor prognosis of hepatocellular carcinoma (HCC). However, the underlying mechanism of HCC metastasis remains largely unknown. Here, we showed that TXNDC12, a thioredoxin-like protein, was upregulated in highly metastatic HCC cell lines as well as in portal vein tumor thrombus and lung metastasis tissues of HCC patients. We found that the enforced expression of TXNDC12 promoted metastasis both in vitro and in vivo. Subsequent mechanistic investigations revealed that TXNDC12 promoted metastasis through upregulation of the ZEB1-mediated epithelial–mesenchymal transition (EMT) process. We subsequently showed that TXNDC12 overexpression stimulated the nuclear translocation and activation of β-catenin, a positive transcriptional regulator of ZEB1. Accordingly, we found that TXNDC12 interacted with β-catenin and that the thioredoxin-like domain of TXNDC12 was essential for the interaction between TXNDC12 and β-catenin as well as for TXNDC12-mediated β-catenin activation. Moreover, high levels of TXNDC12 in clinical HCC tissues correlated with elevated nuclear β-catenin levels and predicted worse overall and disease-free survival. In summary, our study demonstrated that TXNDC12 could activate β-catenin via protein–protein interaction and promote ZEB1-mediated EMT and HCC metastasis.

Abstract 374: Inhibition of Mitochondrial CaMKII Reduces Vascular Smooth Muscle Migration and Neointima Formation and Halts Mitochondrial Mobility

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Emily Nguyen ◽  
Olha Koval ◽  
Isabella Grumbach
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Mitochondrial Fission ◽  
Leading Edge ◽  
Neointima Formation ◽  
Vsmc Proliferation ◽  
Mitochondrial Motility ◽  
And Migration

Background: Restenosis after angioplasty for coronary vascular disease remains a critical problem in cardiovascular medicine. Vascular smooth muscle cell (VSMC) migration and proliferation cause restenosis through neointima formation. Mitochondrial motility is likely necessary for cell proliferation and migration, and is inhibited in microdomains with increased Ca 2+ . The Ca 2+ /calmodulin-dependent kinase II (CaMKII) in mitochondria (mtCaMKII) is proposed to control mitochondrial matrix Ca 2+ uptake through mitochondrial Ca 2+ uniporter (MCU). Thus, we hypothesized that blocking mtCaMKII decreases VSMC migration and neointima formation by decreasing mitochondrial motility. Methods: mtCaMKII was inhibited by expression of the mitochondria-targeted CaMKII inhibitor peptide (CaMKIIN) in a novel transgenic mouse model in smooth muscle only (SM-mtCaMKIIN) or delivered by adenoviral transduction (Ad-mtCaMKIIN). Results: In our models, mtCaMKIIN was detected selectively in mitochondria of VSMC. mtCaMKIIN significantly reduced mitochondrial Ca 2+ current and Ca 2+ content compared to WT in vivo and in vitro. SM-mtCaMKIIN mice showed significantly reduced neointimal area 28 days after endothelial injury (n=8, p<0.05) and fewer proliferating neointimal cells by PCNA staining. In vitro, Ad-mtCaMKIIN mildly reduced VSMC proliferation and mitochondrial ROS production without altering maximal respiration after PDGF treatment. Ad-mtCaMKIIN abolished VSMC migration, as did mitoTEMPO and MCU inhibitor Ru360. Ad-mtCaMKIIN blocked mitochondrial mobility towards the leading edge, while relocation of mitochondria was seen in WT cells 6 h after PDGF treatment. Mitochondrial redistribution was also inhibited by Ru360, but not by mitoTEMPO or cytoplasmic CaMKII inhibition. Mitochondrial fission promotes cell migration. Accordingly, PDGF increased mitochondrial particles in WT VSMC, while mitochondria in Ad-mtCaMKIIN cells were fragmented and unresponsive to PDGF treatment. Conclusions: mtCaMKIIN prevents mitochondrial distribution to the leading edge and reduces VSMC migration and neointima formation. These data suggest mitochondrial Ca 2+ regulation plays an important role in VSMC migration by altering mitochondrial location.

scholarly journals Salusin-α Inhibits Proliferation and Migration of Vascular Smooth Muscle Cell via Akt/mTOR Signaling

2018 ◽  
Vol 50 (5) ◽  
pp. 1740-1753 ◽  
Author(s):  
Shoucui Gao ◽  
Liran Xu ◽  
Yali Zhang ◽  
Qingqing Yu ◽  
Jiayan Li ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Atherosclerotic Lesion ◽  
Cell Counting ◽  
Matrix Metalloproteinase 2 ◽  
Aortic Lesion ◽  
Vsmc Proliferation ◽  
And Migration ◽  
Proliferation And Migration

Background/Aims: The proliferation and migration of vascular smooth muscle cells (VSMCs) are key steps in the progression of atherosclerosis. The aim of the present study was to investigate the potential roles of salusin-α in the functions of VSMCs during the development of atherosclerosis. Methods: In vivo, the effects of salusin-α on atherogenesis were examined in rabbits fed a cholesterol diet. The aortas were en face stained with Sudan IV to evaluate the gross atherosclerotic lesion size. The cellular components of atherosclerotic plaques were analyzed by immunohistochemical methods. In vitro, Cell Counting Kit-8 and wound-healing assays were used to assess the effects of salusin-α on VSMC proliferation and migration. In addition, western blotting was used to evaluate the total and phosphorylated levels of Akt (also known as protein kinase B) and mammalian target of rapamycin (mTOR) in VSMCs. Results: Salusin-α infusion significantly reduced the aortic lesion areas of atherosclerosis, with a 39% reduction in the aortic arch, a 71% reduction in the thoracic aorta, and a 71% reduction in the abdominal aorta; plasma lipid levels were unaffected. Immunohistochemical staining showed that salusin-α decreased both macrophage- and VSMC-positively stained areas in atherosclerotic lesions by 54% and 69%, cell proliferative activity in the intima and media of arteriosclerotic lesions, and matrix metalloproteinase 2 (MMP-2) and MMP-9 expression in plaques. Studies using cultured VSMCs showed that salusin-α decreased VSMC migration and proliferation via reduced phosphorylation of Akt and mTOR. Conclusion: Our data indicate that salusin-α suppresses the development of atherosclerosis by inhibiting VSMC proliferation and migration through the Akt/mTOR pathway.

Differential regulation of vascular smooth muscle and endothelial cell proliferation in vitro and in vivo by cAMP/PKA-activated p85αPI3K

2009 ◽  
Vol 297 (6) ◽  
pp. H2015-H2025 ◽  
Author(s):  
Daniele Torella ◽  
Cosimo Gasparri ◽  
Georgina M. Ellison ◽  
Antonio Curcio ◽  
Angelo Leone ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Neointimal Hyperplasia ◽  
Endothelial Cell Proliferation ◽  
Balloon Injury ◽  
Vsmc Proliferation ◽  
Endothelial Regeneration ◽  
Proliferation In Vitro

cAMP inhibits proliferation in most cell types, triggering different and sometimes opposing molecular pathways. p85α (phosphatidylinositol 3-kinase regulatory subunit) is phosphorylated by cAMP/PKA in certain cell lineages, but its effects on vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) are unknown. In the present study, we evaluated 1) the role of p85α in the integration of cAMP/PKA-dependent signaling on the regulation of VSMC and EC growth in vitro; and 2) the effects of PKA-modified p85α on neointimal hyperplasia and endothelial healing after balloon injury in vivo. Plasmid constructs carrying wild-type and PKA-modified p85α were employed in VSMCs and ECs in vitro and after balloon injury in rat carotid arteries in vivo. cAMP/PKA reduced VSMC proliferation through p85α phosphorylation. Transfected PKA-activated p85α binds p21ras, reducing ERK1/2 activation and VSMC proliferation in vitro. In contrast, EC proliferation inhibition by cAMP is independent from PKA modification of p85α and ERK1/2 inhibition; indeed, PKA-activated p85α did not inhibit per se ERK1/2 activation and proliferation in ECs in vitro. Interestingly, cAMP reduced both VSMC and EC apoptotic death through p85α phosphorylation. Accordingly, PKA-activated p85α triggered Akt activation, reducing both VSMC and EC apoptosis in vitro. Finally, compared with controls, vascular gene transfer of PKA-activated p85α significantly reduced neointimal formation after balloon injury in rats, without inhibiting endothelial regeneration of the injured arterial segment. In conclusions, PKA-activated p85α integrates cAMP/PKA signaling differently in VSMCs and ECs. By reducing neointimal hyperplasia without inhibiting endothelial regeneration, it exerts a protective effect against restenosis after balloon injury.

Abstract 459: O-Linked N-Acetylglucosamine Promotes Vascular Smooth Muscle Cell Dedifferentiation and Intimal Hyperplasia

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Ashley J Bauer ◽  
Kristen L Leslie ◽  
Allison C Ostriker ◽  
Kathleen A Martin
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Intimal Hyperplasia ◽  
Transcriptional Repression ◽  
Human Coronary Artery ◽  
Artery Ligation ◽  
Vsmc Proliferation ◽  
Marker Expression

Vascular smooth muscle cells (VSMCs) exhibit a unique phenotypic plasticity that underlies numerous cardiovascular pathologies. Platelet-derived growth factor (PDGF) promotes VSMC dedifferentiation characterized by proliferation and decreased contractile protein expression while the mTORC1 inhibitor and stent therapeutic rapamycin inhibits these effects. The enzyme O-linked N-Acetylglucosamine (O-GlcNAc) Transferase (OGT) adds O-GlcNAc modifications to serine or threonine in proteins and has been implicated in cardiovascular diseases. We hypothesized that OGT may regulate VSMC plasticity. We found that OGT and O-GlcNAc expression were associated with dedifferentiation, as both were decreased by rapamycin, but increased with PDGF treatment in human coronary artery SMCs. Knocking down OGT in vitro increased contractile marker expression at the mRNA and protein levels, including MYH11, CNN, TGLN, and ACTA2, while decreasing VSMC proliferation. Conversely, OGT overexpression inhibited expression of MHY11, CNN, and TGLN. Consistent with a role in dedifferentiation, immunostaining revealed that OGT and O-GlcNAc were increased following femoral artery endothelial denudation injury in C57BL/6 mice. Notably, smooth muscle-specific OGT knockout attenuated neointima formation relative to controls in a carotid artery ligation model of intimal hyperplasia. In conclusion, these findings indicate that PDGF and vascular injury increase OGT expression and O-GlcNAc modifications in SMCs in vitro and in vivo, leading to OGT-dependent transcriptional repression of contractile marker expression and promotion of intimal hyperplasia.

scholarly journals Secreted Frizzled Related Protein 2 Modulates Epithelial–Mesenchymal Transition and Stemness via Wnt/β-Catenin Signaling in Choriocarcinoma

2018 ◽  
Vol 50 (5) ◽  
pp. 1815-1831 ◽  
Author(s):  
Xianling Zeng ◽  
Yafei Zhang ◽  
Huiqiu Xu ◽  
Taohong Zhang ◽  
Yan Xue ◽  
...  
Keyword(s):  
Cell Lines ◽  
Molecular Mechanisms ◽  
Epithelial Mesenchymal Transition ◽  
Underlying Mechanism ◽  
Tumor Promoter ◽  
Related Protein ◽  
Mesenchymal Transition ◽  
Jar Cells

Background/Aims: Choriocarcinoma (CC) is a highly aggressive gestational trophoblastic neoplasia; however, the underlying molecular mechanisms of its invasiveness and metastasis remain poorly understood. Human secreted frizzled-related protein 2 (SFRP2) could function as a tumor promoter or suppressor in different tumors, yet the role it plays in CC’s invasion and metastasis is thoroughly unclear. The current study was aimed to explore the function and underlying mechanism of SFRP2 in CC. Methods: The expression of SFRP2 in CC tissues was examined via immunohistochemistry. The methylation level and expression of SFRP2 in CC cell lines, JEG-3 and JAR were examined via bisulfite sequencing PCR (BSP), western blotting and quantitative RT-PCR. The biological role of increasing expressed SFRP2 through its promoter demethylation with 5-Aza-2’-deoxycytidine (5-Aza) was examined by a series of in vitro functional studies. Furthermore, lentivirus transfection technology was adopted to investigate the biological roles of SFRP2 knockdown in JEG-3 and JAR cells in vitro and in vivo. Moreover, its downstream signaling pathway was investigated. Results: SFRP2 was downregulated in CC tissues, and its expression was inversely related to its promoter hypermethylation frequency in JEG-3 and JAR cells. Increased SFRP2 through its promoter demethylation inhibited cell migration, invasion and colony formation in JEG-3 and JAR cells, whereas decreased SFRP2 reversed the epithelial-mesenchymal transition (EMT) process and stemness in JEG-3 and JAR cells both in vitro and vivo. Mechanistically, SFRP2 regulated the EMT and stemness of CC cell lines via canonical Wnt/β-catenin signaling, validated by the usage of a Wnt activator and inhibitor. Conclusion: The current study indicates that downregulated SFRP2 has potent tumor-promotive effects in CC through the modulation of cancer stemness and the EMT phenotype via activation of Wnt/β-catenin signaling in vitro and in vivo.

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