scholarly journals Transendothelial movement of adiponectin is restricted by glucocorticoids

2017 ◽  
Vol 234 (2) ◽  
pp. 101-114 ◽  
Author(s):  
Thanh Q Dang ◽  
Nanyoung Yoon ◽  
Helen Chasiotis ◽  
Emily C Dunford ◽  
Qilong Feng ◽  
...  

Altered permeability of the endothelial barrier in a variety of tissues has implications both in disease pathogenesis and treatment. Glucocorticoids are potent mediators of endothelial permeability, and this forms the basis for their heavily prescribed use as medications to treat ocular disease. However, the effect of glucocorticoids on endothelial barriers elsewhere in the body is less well studied. Here, we investigated glucocorticoid-mediated changes in endothelial flux of Adiponectin (Ad), a hormone with a critical role in diabetes. First, we used monolayers of endothelial cells in vitro and found that the glucocorticoid dexamethasone increased transendothelial electrical resistance and reduced permeability of polyethylene glycol (PEG, molecular weight 4000 Da). Dexamethasone reduced flux of Ad from the apical to basolateral side, measured both by ELISA and Western blotting. We then examined a diabetic rat model induced by treatment with exogenous corticosterone, which was characterized by glucose intolerance and hyperinsulinemia. There was no change in circulating Ad but less Ad protein in skeletal muscle homogenates, despite slightly higher mRNA levels, in diabetic vs control muscles. Dexamethasone-induced changes in Ad flux across endothelial monolayers were associated with alterations in the abundance of select claudin tight junction (TJ) proteins. shRNA-mediated knockdown of one such gene, claudin-7, in HUVEC resulted in decreased TEER and increased adiponectin flux, confirming the functional significance of Dex-induced changes in its expression. In conclusion, our study identifies glucocorticoid-mediated reductions in flux of Ad across endothelial monolayers in vivo and in vitro. This suggests that impaired Ad action in target tissues, as a consequence of reduced transendothelial flux, may contribute to the glucocorticoid-induced diabetic phenotype.

2020 ◽  
Vol 26 (45) ◽  
pp. 5783-5792
Author(s):  
Kholood Abid Janjua ◽  
Adeeb Shehzad ◽  
Raheem Shahzad ◽  
Salman Ul Islam ◽  
Mazhar Ul Islam

There is compelling evidence that drug molecules isolated from natural sources are hindered by low systemic bioavailability, poor absorption, and rapid elimination from the human body. Novel approaches are urgently needed that could enhance the retention time as well as the efficacy of natural products in the body. Among the various adopted approaches to meet this ever-increasing demand, nanoformulations show the most fascinating way of improving the bioavailability of dietary phytochemicals through modifying their pharmacokinetics and pharmacodynamics. Curcumin, a yellowish pigment isolated from dried ground rhizomes of turmeric, exhibits tremendous pharmacological effects, including anticancer activities. Several in vitro and in vivo studies have shown that curcumin mediates anticancer effects through the modulation (upregulation and/or downregulations) of several intracellular signaling pathways both at protein and mRNA levels. Scientists have introduced multiple modern techniques and novel dosage forms for enhancing the delivery, bioavailability, and efficacy of curcumin in the treatment of various malignancies. These novel dosage forms include nanoparticles, liposomes, micelles, phospholipids, and curcumin-encapsulated polymer nanoparticles. Nanocurcumin has shown improved anticancer effects compared to conventional curcumin formulations. This review discusses the underlying molecular mechanism of various nanoformulations of curcumin for the treatment of different cancers. We hope that this study will make a road map for preclinical and clinical investigations of cancer and recommend nano curcumin as a drug of choice for cancer therapy.


Author(s):  
Hao Xu ◽  
Liying Wu ◽  
Guojia Yuan ◽  
Xiaolu Liang ◽  
Xiaoguang Liu ◽  
...  

: Hepatic disease negatively impacts liver function and metabolism. Primary human hepatocytes are the gold standard for the prediction and successful treatment of liver disease. However, the sources of hepatocytes for drug toxicity testing and disease modeling are limited. To overcome this issue, pluripotent stem cells (PSCs) have emerged as an alternative strategy for liver disease therapy. Human PSCs, including embryonic stem cells (ESC) and induced pluripotent stem cells (iPSC) can self-renew and give rise to all cells of the body. Human PSCs are attractive cell sources for regenerative medicine, tissue engineering, drug discovery, and developmental studies. Several recent studies have shown that mesenchymal stem cells (MSCs) can also differentiate (or trans-differentiate) into hepatocytes. Differentiation of human PSCs and MSCs into functional hepatocyte-like cells (HLCs) opens new strategies to study genetic diseases, hepatotoxicity, infection of hepatotropic viruses, and analyze hepatic biology. Numerous in vitro and in vivo differentiation protocols have been established to obtain human PSCs/MSCs-derived HLCs and mimic their characteristics. It was recently discovered that microRNAs (miRNAs) play a critical role in controlling the ectopic expression of transcription factors and governing the hepatocyte differentiation of human PSCs and MSCs. In this review, we focused on the role of miRNAs in the differentiation of human PSCs and MSCs into hepatocytes.


2018 ◽  
Vol 38 (4) ◽  
Author(s):  
Aly Shamseddin ◽  
Céline Crauste ◽  
Erwan Durand ◽  
Pierre Villeneuve ◽  
Grégor Dubois ◽  
...  

Gelatinolytic matrix metalloproteinases (MMP-2, -9) play a critical role not only in mammals physiology but also during inflammation and healing processes. The natural stilbenoid, resveratrol (RES), exhibits potent antioxidant effects, in a hormetic mode of action, and is known to inhibit MMP-9. However, RES administration exhibits major issues, including poor bioavailability and water solubility, hampering its potential therapeutic effect in vivo. In the present study, we synthesized and evaluated five novel RES–lipid conjugates to increase their cell membrane penetration and improve their bioavailability. The best in vitro MMP-9 inhibitory activity of RES–lipids conjugates was observed with RES-linoleic acid (LA) (5 µM), when dissolved in a natural deep eutectic solvent (NADES), composed of an equimolar content of 1,2-propanediol:choline chloride (ChCl):water. The inhibition of MMP-9 expression by RES-LA in activated THP-1 monocytes, was, at least due to the deactivation of ERK1/2 and JNK1/2 MAP kinase signaling pathways. Moreover, RES-LA exhibited a strong effect protecting the TNF-α-induced exacerbated permeability in an HUVEC in vitro monolayer (by 81%) via the integrity protection of intercellular junction proteins from the MMP-9 activity. This effect was confirmed by using several complementary approaches including, the real-time monitoring of trans-endothelial electric resistance (TEER), the Transwell HUVEC permeability level, the microscopic examination of the platelet endothelial cell adhesion molecule-1 (CD31/PECAM-1) integrity as well as the fluorescence in intercellular spaces. Consequently, following this strong in vitro proof-of-concept, there is a need to test this promising RES–lipid derivative compound to control the pathological endothelial permeability in vivo.


2019 ◽  
Author(s):  
Mabruka Alfaidi ◽  
Umesh Bhattarai ◽  
Elizabeth D Cockerham ◽  
A.W. Orr

AbstractAlteration in hemodynamic shear stress at atheroprone sites promotes endothelial paracellular pore formation and permeability. Previously, we have reported that a peptide inhibitor to Nck prevented shear stress-induced p21 activated kinase (PAK) activation and endothelial permeability. However, the specificity of this peptide is unclear, and the role of individual Nck isoforms remain unknown. Here, we show that genetic deletion of Nck1/2 adaptor proteins significantly ameliorates shear stress induced permeability, and selective isoform depletion suggests distinct signaling mechanisms. Only Nck1 deletion significantly reduces flow-induced paracellular pore formation and permeability, whereas Nck2 depletion has no significant effects. Additionally, Nck1 reexpression, but not Nck2, restores shear stress-induced permeability in Nck1/2 knockout cells, confirming the non-compensating roles. In vivo, using the partial carotid ligation model of disturbed flow, Nck1 knockout prevented the increase in vascular permeability, as assessed by both Evans blue extravasation and leakage of plasma fibrinogen into the vessel wall. Domain swap experiments mixing SH2 (phosphotyrosine binding) and SH3 (proline rich binding) domains between Nck1 and Nck2 showed a dispensable role for SH2 domains but a critical role for the Nck1 SH3 domains in rescuing shear stress-induced endothelial permeability. Consistent with this, both Nck1 and Nck2 bind to PECAM-1 (SH2 dependent) in response to shear stress, but only Nck1 ablation interferes with shear stress-induced PAK2 activation (SH3 dependent). This work provides the first evidence that Nck1 and Nck2 play distinct roles in flow-induced vascular permeability.New and NoteworthyThe present study shows a specific role for Nck1 in endothelial permeability in response to shear stress. Using in vitro and in vivo models, we demonstrate improvement in endothelial barrier integrity in cells subjected to disturbed flow only following Nck1 but not Nck2 deletion. Selective Nck1 inhibition may limit endothelial permeability at sites of disturbed flow to reduce atherosclerosis without affecting angiogenesis, which requires both Nck1 and Nck2 inhibition.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2202-2202
Author(s):  
Corinna Cavan Pedersen ◽  
Rehannah Borup ◽  
Anne Fischer-Nielsen ◽  
Helena Mora-Jensen ◽  
Anna Fossum ◽  
...  

Abstract Emergency granulopoiesis refers to the increased production of neutrophils in bone marrow and their release into circulation induced by severe infection. Several studies point to a critical role for granulocyte colony-stimulating factor (G-CSF) as the main mediator of emergency granulopoiesis. However, the consequences of G-CSF stimulation on the transcriptome of neutrophils and their precursors have not yet been elucidated in humans. Here, we investigate the changes in mRNA and miRNA expression in successive stages of neutrophil development following in vivo administration of G-CSF in humans, mimicking emergency granulopoiesis. Blood samples were collected from healthy individuals after five days of G-CSF administration. Neutrophil precursors were sorted into discrete stages of maturation by flow cytometry and extracted RNA was subjected to microarray analysis. mRNA levels were compared to previously published expression levels in corresponding populations of neutrophil precursors isolated from bone marrow of untreated, healthy individuals. miRNA expression was investigated in the most mature cell population to determine G-CSF-induced changes in circulating neutrophils. G-CSF substantially affected mRNA and miRNA expression patterns, demonstrating significant impact on neutrophil development and function. 1110 mRNAs were differentially expressed more than 2-fold with G-CSF while the treatment induced changes in the levels of 73 miRNAs in the mature population. In addition, G-CSF treatment reduced the levels of four out of five measured granule proteins in mature neutrophils including hCAP-18, which was completely deficient in neutrophils from G-CSF-treated donors. Cell cycle analysis pointed towards an induced proliferative capacity of myelocytes. These results indicate that multiple biological processes are altered in order to satisfy the increased demand for neutrophils during G-CSF-induced emergency granulopoiesis. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1737-1737
Author(s):  
Liyan Pang ◽  
Xun Wang ◽  
Yuhuan Wang ◽  
Gerd Blobel ◽  
Mortimer Poncz

Abstract The pointed-domain Ets transcription factor Fli-1 has a critical role during megakaryocyte-specific gene expression. Previously, we demonstrated that Fli-1 occupies the early megakaryocyte-specific gene αIIb in vivo. Moreover, our work suggested a mechanism for Fli-1 function by showing that Fli-1 facilitates GATA-1/FOG-1 dependent expression of the αIIb gene. However, studies by others with a targeted disruption of the Fli-1 gene in mice showed that while Fli-1 is essential for normal megakaryocyte maturation, αIIb mRNA levels were not significantly reduced in the resulting megakaryocytes, suggesting that a related Ets factor(s) might compensate for the loss of Fli-1. Here we show that the widely expressed pointed domain Ets protein GABPα specifically binds in vitro to Ets elements from two early megakaryocyte-specific genes, αIIb and c-mpl. Chromatin immunoprecipitation (ChIP) experiments using primary murine fetal liver-derived megakaryocytes reveal that GABPα associates with αIIb and c-mpl in vivo. Moreover, GABPα is capable of mediating GATA-1/FOG-1 synergy in the context of αIIb promoter constructs. These results suggest that GABPα contributes to megakaryocyte-restricted gene expression and is capable of at least partially compensating for the loss of Fli-1. However, loss of Fli-1 leads to a pronounced decrease in the expression of the late megakaryocyte-specific gene GPIX, indicating that compensation by GABPα is incomplete. Consistent with this observation, ChIP experiments fail to detect significant levels of GABPα at the regulatory region of GPIX while Fli-1 is readily detected there. Together, these results point to a model in which Fli-1 and GABPα serve overlapping, but distinct roles, during the development of megakaryocytes. GABPα may be important during early megakaryopoiesis, but Fli-1 exerting an essential role during late stages of maturation.


2001 ◽  
Vol 281 (2) ◽  
pp. C662-C669 ◽  
Author(s):  
Grace Y. Song ◽  
Chun-Shiang Chung ◽  
Irshad H. Chaudry ◽  
Alfred Ayala

Although studies indicate that a shift from a Th1 to a Th2 response contributes to a marked suppression of cell-mediated immunity during sepsis, the mechanism by which this occurs remains unknown. Given that the mitogen-activated protein kinase (MAPK) p38 plays a critical role in the activation and function of immune cells, the aim of this study was to determine the contribution of MAPK p38 activation to the immune dysfunction seen in polymicrobial sepsis. To study this, polymicrobial sepsis was induced in C3H/HeN male mice by cecal ligation and puncture (CLP). Splenic lymphocytes and purified T cells were harvested 24 h post-CLP, pretreated with the specific MAPK p38 inhibitor SB-203580, and then stimulated with a monoclonal antibody against the T cell marker CD3. The results indicate that interleukin (IL)-2 release is markedly depressed while the release of the immunosuppressive mediator, IL-10, as well as mRNA levels of IL-10 and IL-4, are augmented after CLP. Inhibition of MAPK p38 suppressed in vitro IL-10 levels as well as IL-10 and IL-4 gene expression while restoring the release of IL-2. To determine whether these in vitro findings could be translated to an in vivo setting, mice were given 100 mg of SB-203580/kg body wt or saline vehicle (intraperitoneal) at 12 h post-CLP. Examination of ex vivo lymphocyte responsiveness indicated that, as with the in vitro finding, septic mouse Th1 responsiveness was restored. In light of our recent finding that delayed in vivo SB-203580 treatment also improved survival after CLP, we believe that these results not only illustrate the role of MAPK p38 in the induction of immunosuppressive agents in sepsis but demonstrate that SB-203580 administration after the initial proinflammatory state of sepsis significantly prevents the morbidity from sepsis.


Author(s):  
Sanni Tuominen ◽  
Thomas Keller ◽  
Nataliia Petruk ◽  
Francisco López-Picón ◽  
Dominik Eichin ◽  
...  

Abstract Background Many malignant tumours have increased TSPO expression, which has been related to a poor prognosis. TSPO-PET tracers have not comprehensively been evaluated in peripherally located tumours. This study aimed to evaluate whether N,N-diethyl-2-(2-(4-([18F]fluoro)phenyl)-5,7-dimethylpyrazolo[1,5-a]pyrimidin-3-yl)acetamide ([18F]F-DPA) can reflect radiotherapy (RT)-induced changes in TSPO activity in head and neck squamous cell carcinoma (HNSCC). Methods RT was used to induce inflammatory responses in HNSCC xenografts and cells. [18F]F-DPA uptake was measured in vivo in non-irradiated and irradiated tumours, followed by ex vivo biodistribution, autoradiography, and radiometabolite analysis. In vitro studies were performed in parental and TSPO-silenced (TSPO siRNA) cells. TSPO protein and mRNA expression, as well as tumour-associated macrophages (TAMs), were also assessed. Results In vivo imaging and ex vivo measurement revealed significantly higher [18F]F-DPA uptake in irradiated, compared to non-irradiated tumours. In vitro labelling studies with cells confirmed this finding, whereas no effect of RT on [18F]F-DPA uptake was detected in TSPO siRNA cells. Radiometabolite analysis showed that the amount of unchanged [18F]F-DPA in tumours was 95%, also after irradiation. PK11195 pre-treatment reduced the tumour-to-blood ratio of [18F]F-DPA by 73% in xenografts and by 88% in cells. TSPO protein and mRNA levels increased after RT, but were highly variable. The proportion of M1/M2 TAMs decreased after RT, whereas the proportion of monocytes and migratory monocytes/macrophages increased. Conclusions [18F]F-DPA can detect changes in TSPO expression levels after RT in HNSCC, which does not seem to reflect inflammation. Further studies are however needed to clarify the physiological mechanisms regulated by TSPO after RT.


Blood ◽  
2011 ◽  
Vol 117 (26) ◽  
pp. 6999-7006 ◽  
Author(s):  
Sara I. Cunha ◽  
Kristian Pietras

Members of the TGF-β family act on many, if not all, cell types within the body, producing diverse and complex cellular outcomes. Activation of the endothelial cell-restricted TGF-β type I receptor ALK1 results from the binding of several different ligands of the TGF-β family, including bone morphogenetic protein (BMP) 9, BMP10, and TGF-β. Mounting genetic, pharmacologic, and histopathologic evidence supports a critical role for ALK1 signaling in regulation of both developmental and pathologic blood vessel formation. However, the precise function of TGF-β family signaling in endothelial cells is difficult to predict and appears highly context dependent because of the multitude of ligands and receptors influencing the final outcome. Pharmacologic inhibitors of ALK1 have recently been developed and will allow for more accurate studies of ALK1 function in vivo, as well as for assessment of ALK1 as a target for suppression of angiogenesis during tumor development. Herein, we will summarize the current view of ALK1 regulation of endothelial cell phenotype in vitro and in vivo as well as provide an outlook for the ongoing clinical trials of ALK1 inhibitors in malignant disease.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1147-1147
Author(s):  
Nhu Nguyen ◽  
Kristbjorn Orri Gudmundsson ◽  
Anthony R. Soltis ◽  
Kevin Oakley ◽  
Yufen Han ◽  
...  

Abstract Abnormal activation of SETBP1 due to overexpression or missense mutations occurs frequently in various myeloid neoplasms and associates with poor prognosis. Direct activation of Hoxa9/Hoxa10/Myb transcription by SETBP1 and its missense mutants is essential for their transforming capability; however, the underlying mechanisms for such activation remain elusive. We found that knockdown of Mll1 in mouse myeloid progenitors immortalized by SETBP1 or its missense mutant SETBP1(D/N) caused significant reduction in the mRNA levels of Hoxa9/Hoxa10/Myb, suggesting that Mll1 is critical for their transcriptional activation induced by SETBP1 and its missense mutants. Physical association of MLL1 with SETBP1/SETBP1(D/N) was readily detected by co-immunoprecipitation in nuclear extracts of these cells, further suggesting that they may form a complex in myeloid cells to activate transcription. This complex formation is likely mediated by direct interactions between SETBP1/SETBP1(D/N) and MLL1 as both SETBP1 and SETBP1(D/N) are capable of interacting with multiple regions of MLL1 in binding assays using proteins synthesized by in vitro transcription and translation. To better understand the extent of SETBP1/SETBP1(D/N)-MLL1 interaction in regulating gene transcription, we carried out both ChIP-seq and RNA-seq analysis in mouse Lin -Sca-1 +c-Kit + (LSK) cells transduced by pMYs retrovirus expressing SETBP1 or SETBP1(D/N) or empty pMYs virus. These analyses revealed extensive overlap in genomic occupancy for MLL1 and SETBP1/SETBP1(D/N) and their cooperation in activating many oncogenic transcription factor genes in addition to Hoxa9/Hoxa10/Myb, including additional HoxA genes (Hoxa1, Hoxa3, Hoxa5, Hoxa6, and Hoxa7), Myc, Eya1, Mef2c, Meis1, Sox4, Mecom, and Lmo2. A large group of ribosomal protein genes were also found to be directly activated by MLL1 and SETBP1/SETBP1(D/N), identifying ribosomal biogenesis as another significant pathway induced by their cooperation. To further assess the requirement for MLL1 in SETBP1-induced transformation using a genetic approach, we also generated SETBP1/SETBP1(D/N)-induced immortalized myeloid progenitors and AMLs using LSK cells from Mll1 conditional knockout mice. Mll1 deletion in immortalized progenitors significantly decreased SETBP1/SETBP1(D/N)-induced transcriptional activation and their colony-forming potential. More importantly, Mll1 deletion significantly extended the survival of mice transplanted with SETBP1/SETBP1(D/N)-induced AMLs, indicating that Mll1 is essential for the maintenance of such leukemias in vivo. We further found that pharmacological inhibition of MLL1 complex using a WDR5 inhibitor OICR-9429 efficiently abrogated SETBP1/SETBP1(D/N)-induced transcriptional activation and transformation. Thus, MLL1 complex plays a critical role in Setbp1-induced transcriptional activation and transformation and represents a promising target for treating myeloid neoplasms with SETBP1 activation. Disclosures Maciejewski: Novartis: Consultancy; Regeneron: Consultancy; Alexion: Consultancy; Bristol Myers Squibb/Celgene: Consultancy.


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