scholarly journals Sirolimus Suppresses Phosphorylation of Cofilin and Reduces Interstitial Septal Thickness in Sporadic Lymphangioleiomyomatosis

2021 ◽  
Vol 22 (16) ◽  
pp. 8564
Author(s):  
Yen-Lin Huang ◽  
Po-Ru Chen ◽  
Ying-Ju Lai ◽  
Hsao-Hsun Hsu
Keyword(s):  
Smooth Muscle ◽  
Structural Analysis ◽  
Mtor Inhibitor ◽  
Mammalian Target Of Rapamycin ◽  
Potential Effect ◽  
Histopathological Changes ◽  
Septal Thickness ◽  
Proven Efficacy ◽  
Therapeutic Mechanisms

Sporadic lymphangioleiomyomatosis (S-LAM) is a rare lung disease characterized by the proliferation of smooth muscle-like LAM cells and progressive cystic destruction. Sirolimus, a mammalian target of rapamycin (mTOR) inhibitor, has a proven efficacy in patients with LAM. However, the therapeutic mechanisms of sirolimus in LAM remain unclear. We aimed to evaluate sirolimus-related lung parenchymal changes and the potential effect in LAM cells and modulating pathological cystic destruction. Lung specimens were examined for histopathological changes by HMB45 staining and compared the LAM patients treated with and without sirolimus. We detected the overexpression of mTOR, HMB45, and phosphorylation of cofilin (p-cofilin) in LAM patients. Sirolimus showed efficacy in patients with LAM, who exhibited a reduced expression of mTOR and p-cofilin as well as reduced interstitial septal thickness. In addition, sirolimus suppresses mTOR and p-cofilin, thus suppressing the migration and proliferation of LAM cells isolated from the patient’s lung tissue. This study demonstrates that interstitial septal thickness, as determined by histological structural analysis. Sirolimus effectively reduced the expression of p-cofilin and interstitial septal thickness, which may be a novel mechanism by sirolimus. Moreover, we develop a new method to isolate and culture the LAM cell, which can test the possibility of medication in vitro and impact this current study has on the LAM field. The development of approaches to interfere with mTOR-cofilin1-actin signaling may result in an option for S-LAM therapy.

Effect of NVP-BEZ235, a dual PI3K/mTOR inhibitor, on chemotherapy and antiangiogenic response in pancreatic cancer.

2012 ◽  
Vol 30 (4_suppl) ◽  
pp. 243-243 ◽  
Author(s):  
Katherine T. Ostapoff ◽  
Niranjan Awasthi ◽  
Peter L. Yen ◽  
Changhua Zhang ◽  
Margaret A. Schwarz ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Combination Therapy ◽  
Mtor Inhibitor ◽  
Mammalian Target Of Rapamycin ◽  
Animal Experiments ◽  
Ductal Adenocarcinoma ◽  
Clinical Benefits ◽  
Induced Apoptosis

243 Background: The phosphatidylinositol-3-kinase (PI3K)/AKT and mammalian target of rapamycin (mTOR) signaling pathway dysregulation is a prominent feature of pancreatic ductal adenocarcinoma (PDAC). Gemcitabine (GEM), a standard systemic treatment for PDAC, has limited clinical benefits. The present study investigated the effects of NVP-BEZ235 (BEZ235), a novel dual PI3K/mTOR inhibitor, in combination with gemcitabine and endothelial monocyte activating polypeptide II (EMAP) in experimental PDAC. Methods: Protein expression and cell proliferation were analyzed by Western blotting and WST-1 assay. Animal experiments were performed in murine xenografts. Results: BEZ235 inhibited phospho-AKT (Ser473) and phospho-mTOR (Ser2448) expression in PDAC (AsPC-1), endothelial (HUVECs) and fibroblast (WI-38) cells. NVP-BEZ235 also caused a significant dephosphorylation of downstream mTORC1 target proteins phospho-p70 S6K (Thr389) and phospho-4E-BP1 (Thr37/46). In vitro 72-hour proliferation of four PDAC cell lines was significantly inhibited by BEZ235. Additive effects on proliferation inhibition were observed in the BEZ235 and GEM combination in PDAC cells and in combination of BEZ235 or EMAP with gemcitabine in HUVECs and WI-38 cells. BEZ235, alone or in combination with GEM and EMAP, induced apoptosis in AsPC-1, HUVECs and WI-38 cells as observed by increased expression of cleaved poly (ADP-ribose) polymerase-1 (PARP-1) and caspase-3 proteins. PDAC in vivo therapy demonstrated that compared to controls (median survival: 16 days), animal survival increased after BEZ235 and EMAP therapy alone (both 21 days) and GEM monotherapy (28 days). Further increases in survival occurred in combination therapy groups BEZ235+GEM (30 days, p=0.007), BEZ235+EMAP (27 days, p=0.02), GEM+EMAP (31 days, p=0.001) and BEZ235+GEM +EMAP (33 days, p=0.004). Conclusions: BEZ235 has experimental PDAC antitumor activity in vitro and in vivo that can be enhanced in combination with cytotoxic (GEM) and antiendothelial (EMAP) agents. These findings demonstrate advantages of combination therapy strategies targeting multiple pathways in pancreatic cancer treatment.

Everolimus shows synergistic antimyeloma effects with bortezomib via the AKT/mTOR pathway

2018 ◽  
Vol 67 (1) ◽  
pp. 39-47
Author(s):  
Jing Li ◽  
Zhaoyun Liu ◽  
Yanqi Li ◽  
Qian Jing ◽  
Honglei Wang ◽  
...  
Keyword(s):  
Mtor Inhibitor ◽  
Plasma Cells ◽  
Mammalian Target Of Rapamycin ◽  
Inhibitory Effect ◽  
Mtor Pathway ◽  
Therapeutic Effects ◽  
Mice Model ◽  
Antitumor Effects

Multiple myeloma (MM) is characterized by the proliferation of malignant plasma cells and a subsequent overabundance of monoclonal paraproteins (M proteins). Everolimus works similarly to sirolimus as a mammalian target of rapamycin (mTOR) inhibitor. Bortezomib was the first therapeutic proteasome inhibitor to be tested in humans with MM. However, the combination of these two drugs for the treatment of MM has been rarely reported. In this study, we compared the therapeutic effects of everolimus and bortezomib, as well as those of a combination of everolimus and bortezomib, using an in vitro MM cell line model and in vivo xenograft mouse model. Our results showed that the synergistic antitumor effects of everolimus and bortezomib have significant inhibitory effect through inhibition of the AKT/mTOR pathway in both the MM cell lines and MM-bearing mice model. Our results provided evidence that the mTOR inhibitor, everolimus, will be a potential drug in MM therapy.

scholarly journals Proteomics reveals Rictor as a noncanonical TGF-β signaling target during aneurysm progression in Marfan mice

2018 ◽  
Vol 315 (5) ◽  
pp. H1112-H1126 ◽  
Author(s):  
Sarah J. Parker ◽  
Aleksandr Stotland ◽  
Elena MacFarlane ◽  
Nicole Wilson ◽  
Amanda Orosco ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Aortic Aneurysm ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Transforming Growth Factor ◽  
Mammalian Target Of Rapamycin

The objective of the present study was to 1) analyze the ascending aortic proteome within a mouse model of Marfan syndrome (MFS; Fbn1C1041G/+) at early and late stages of aneurysm and 2) subsequently test a novel hypothesis formulated on the basis of this unbiased proteomic screen that links changes in integrin composition to transforming growth factor (TGF)-β-dependent activation of the rapamycin-independent component of mammalian target of rapamycin (Rictor) signaling pathway. Ingenuity Pathway Analysis of over 1,000 proteins quantified from the in vivo MFS mouse aorta by data-independent acquisition mass spectrometry revealed a predicted upstream regulator, Rictor, that was selectively activated in aged MFS mice. We validated this pattern of Rictor activation in vivo by Western blot analysis for phosphorylation on Thr1135 in a separate cohort of mice and showed in vitro that TGF-β activates Rictor in an integrin-linked kinase-dependent manner in cultured aortic vascular smooth muscle cells. Expression of β3-integrin was upregulated in the aged MFS aorta relative to young MFS mice and wild-type mice. We showed that β3-integrin expression and activation modulated TGF-β-induced Rictor phosphorylation in vitro, and this signaling effect was associated with an altered vascular smooth muscle cell proliferative-migratory and metabolic in vitro phenotype that parallels the in vivo aneurysm phenotype in MFS. These results reveal that Rictor is a novel, context-dependent, noncanonical TGF-β signaling effector with potential pathogenic implications in aortic aneurysm. NEW & NOTEWORTHY We present the most comprehensive quantitative analysis of the ascending aortic aneurysm proteome in Marfan syndrome to date resulting in novel and potentially wide-reaching findings that expression and signaling by β3-integrin constitute a modulator of transforming growth factor-β-induced rapamycin-independent component of mammalian target of rapamycin (Rictor) signaling and physiology in aortic vascular smooth muscle cells.

scholarly journals Rapamycin does not inhibit human cytomegalovirus reactivation from dendritic cells in vitro

2014 ◽  
Vol 95 (10) ◽  
pp. 2260-2266 ◽  
Author(s):  
Thomas E. Glover ◽  
Verity G. Kew ◽  
Matthew B. Reeves
Keyword(s):  
Gene Expression ◽  
Dendritic Cells ◽  
Human Cytomegalovirus ◽  
Mtor Inhibitor ◽  
Hcmv Infection ◽  
Mammalian Target Of Rapamycin ◽  
Epidemiological Studies ◽  
Cytomegalovirus Reactivation

Human cytomegalovirus (HCMV) infection and reactivation are a major cause of morbidity in immune-suppressed patients. Interestingly, epidemiological studies have shown that patients administered the mammalian target of rapamycin (mTOR) inhibitor, sirolimus (rapamycin), exhibit more favourable outcomes, suggestive of activity against HCMV in vivo. Given its relative lack of activity against lytic infection, it is postulated that rapamycin inhibits HCMV reactivation. Here, we showed that rapamycin administered acutely or chronically has little impact on induction of immediate early (IE) gene expression in experimentally latent dendritic cells or cells from naturally latent individuals. Furthermore, we extended these observations to include other inhibitors of mTORC1 and mTORC 2, which similarly have minimal effects on induction of IE gene expression from latency. Taken together, these data suggest that favourable outcomes associated with sirolimus are attributable to indirect effects that influence HCMV reactivation, rather than a direct mechanistic action against HCMV itself.

Neutrophil migration through in vitro interstitial matrix

1992 ◽  
Vol 50 (1) ◽  
pp. 894-895
Author(s):  
J. Roemer ◽  
S.R. Simon
Keyword(s):  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Cell Migration ◽  
Smooth Muscle Cells ◽  
Inflammatory Cell ◽  
Neutrophil Migration ◽  
Culture Conditions ◽  
Aortic Smooth Muscle ◽  
Specific Culture

We are developing an in vitro interstitial extracellular matrix (ECM) system for study of inflammatory cell migration. Falcon brand Cyclopore membrane inserts of various pore sizes are used as a support substrate for production of ECM by R22 rat aortic smooth muscle cells. Under specific culture conditions these cells produce a highly insoluble matrix consisting of typical interstitial ECM components, i.e.: types I and III collagen, elastin, proteoglycans and fibronectin.

The Migration of Human Smooth Muscle Cells In Vitro Is Mediated by Plasminogen Activation and Can Be Inhibited by α2-Macroglobulin Receptor Associated Protein

1997 ◽  
Vol 78 (02) ◽  
pp. 880-886 ◽  
Author(s):  
Monique J Wijnberg ◽  
Paul H A Quax ◽  
Nancy M E Nieuwenbroek ◽  
Jan H Verheijen
Keyword(s):  
Smooth Muscle ◽  
Cell Migration ◽  
Smooth Muscle Cell ◽  
Muscle Cell ◽  
Ldl Receptor ◽  
Migration And Invasion ◽  
Invasion Assay ◽  
Plasminogen Activation ◽  
Smooth Muscle Cell Migration

SummaryThe plasminogen activation system is thought to be important in cell migration processes. A role for this system during smooth muscle cell migration after vascular injury has been suggested from several animal studies. However, not much is known about its involvement in human vascular remodelling. We studied the involvement of the plasminogen activation system in human smooth muscle cell migration in more detail using an in vitro wound assay and a matrix invasion assay. Inhibition of plasmin activity or inhibition of urokinase-type plasminogen activator (u-PA) activity resulted in approximately 40% reduction of migration after 24 h in the wound assay and an even stronger reduction (70-80%) in the matrix invasion assay. Migration of smooth muscle cells in the presence of inhibitory antibodies against tissue-type plasminogen activator (t-PA) was not significantly reduced after 24 h, but after 48 h a 30% reduction of migration was observed, whereas in the matrix invasion assay a 50% reduction in invasion was observed already after 24 h. Prevention of the interaction of u-PA with cell surface receptors by addition of soluble u-PA receptor or α2-macroglobulin receptor associated protein (RAP) to the culture medium, resulted in a similar inhibition of migration and invasion. From these results it can be concluded that both u-PA and t-PA mediated plasminogen activation can contribute to in vitro human smooth muscle cell migration and invasion. Furthermore, the interaction between u-PA and its cell surface receptor appears also to be involved in this migration and invasion process. The inhibitory effects on migration and invasion by the addition of RAP suggests an involvement of a RAP sensitive receptor of the LDL receptor family, possibly the LDL-receptor related protein (LRP) and/or the VLDL receptor.

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