Role of Functionalized Self-Assembled Peptide Hydrogel on In Vitro Vasculogenesis

Soft Matter ◽  
2021 ◽  
Author(s):  
GÜNNUR ONAK ◽  
Oğuzhan Gökmen ◽  
Ziyşan Buse Çevik ◽  
Ozan Karaman
Keyword(s):  
Tissue Constructs ◽  
Integral Role ◽  
Scaffold Materials ◽  
Self Assembled ◽  
Peptide Hydrogel

Fabrication of vascularized tissue constructs plays an integral role in guiding to create clinically relevant tissues. Scaffold materials should be sufficiently vascularized to mimic functional and complex native tissues. Herein,...

14-3-3 Facilitates Insulin-Stimulated Intracellular Trafficking of Insulin Receptor Substrate 1

2002 ◽  
Vol 16 (3) ◽  
pp. 552-562 ◽  
Author(s):  
Xiaoqin Xiang ◽  
Mingsheng Yuan ◽  
Ying Song ◽  
Neil Ruderman ◽  
Rong Wen ◽  
...  
Keyword(s):  
Insulin Receptor ◽  
Intracellular Trafficking ◽  
High Speed ◽  
Insulin Treatment ◽  
Insulin Receptor Substrate ◽  
Insulin Receptor Substrate 1 ◽  
Integral Role ◽  
Endogenous Proteins

Abstract The appearance of a complex between tyrosine-phosphorylated insulin receptor substrate 1 (IRS-1) and PI3K in a high-speed pellet fraction (HSP) is thought to be a key event in insulin action. Conversely, the disappearance of the IRS-1/PI3K complex from this fraction has been linked to insulin desensitization. The present study examines the role of 14-3-3, a specific phospho-serine binding protein, in mediating the disappearance of IRS-1 from the HSP after insulin treatment. An in vitro pull-down assay using recombinant 14-3-3 revealed that insulin enhances the association of 14-3-3 with IRS-1 in cultured adipocytes and that this is completely inhibited by wortmannin. An association of IRS-1 and 14-3-3 was also observed and was maximal after stimulation by insulin, when endogenous proteins were immunoprecipitated. Epidermal growth factor (EGF), 12-O-tetradecanoylphorbol-13-acetate, and okadaic acid, other agents that cause serine/threonine phosphorylation of IRS-1, also stimulated IRS binding to 14-3-3. The enhancement of IRS-1 binding to 14-3-3 by insulin was accompanied by movement of IRS-1 and the p85 subunit of PI3K from the HSP to the cytosol. In keeping with a key role of 14-3-3 in mediating this redistribution of IRS-1, the complexes of IRS-1 and 14-3-3 were found in the cytosol but not in the HSP of insulin-treated cells. In addition, colocalization of IRS-1 and 14-3-3 was observed in the cytoplasm after insulin treatment by confocal microscopy. Finally, the addition of a phosphorylated 14-3-3 binding peptide to an adipocyte homogenate (to remove 14-3-3 from IRS-1) increased the abundance of IRS-1/PI3K complexes in the HSP and decreased their abundance in the cytosol. These findings strongly suggest that 14-3-3 participates in the intracellular trafficking of IRS-1 by promoting the displacement of serine-phosphorylated IRS-1 from particular structures. They also suggest that 14-3-3 proteins could play an integral role in the process of insulin desensitization.

scholarly journals Central role of autophagic UVRAG in melanogenesis and the suntan response

2018 ◽  
Vol 115 (33) ◽  
pp. E7728-E7737 ◽  
Author(s):  
Yongfei Yang ◽  
Gyu-beom Jang ◽  
Xuanjun Yang ◽  
Qiaoxiu Wang ◽  
Shanshan He ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Transcriptional Factor ◽  
Exposed Skin ◽  
Skin Cancers ◽  
Integral Role ◽  
Direct Target ◽  
Lysosome Related Organelles

UV-induced cell pigmentation represents an important mechanism against skin cancers. Sun-exposed skin secretes α-MSH, which induces the lineage-specific transcriptional factor MITF and activates melanogenesis in melanocytes. Here, we show that the autophagic tumor suppressor UVRAG plays an integral role in melanogenesis by interaction with the biogenesis of lysosome-related organelles complex 1 (BLOC-1). This interaction is required for BLOC-1 stability and for BLOC-1–mediated cargo sorting and delivery to melanosomes. Absence of UVRAG dispersed BLOC-1 distribution and activity, resulting in impaired melanogenesis in vitro and defective melanocyte development in zebrafish in vivo. Furthermore, our results establish UVRAG as an important effector for melanocytes’ response to α-MSH signaling as a direct target of MITF and reveal the molecular basis underlying the association between oncogenic BRAF and compromised UV protection in melanoma.

scholarly journals cdk1- and cdk2-Mediated Phosphorylation of MyoD Ser200 in Growing C2 Myoblasts: Role in Modulating MyoD Half-Life and Myogenic Activity

1999 ◽  
Vol 19 (4) ◽  
pp. 3167-3176 ◽  
Author(s):  
Magali Kitzmann ◽  
Marie Vandromme ◽  
Valerie Schaeffer ◽  
Gilles Carnac ◽  
Jean-Claude Labbé ◽  
...  
Keyword(s):  
Half Life ◽  
Site Directed Mutagenesis ◽  
Cyclin B ◽  
Wild Type ◽  
E Box ◽  
Integral Role ◽  
Phosphopeptide Mapping

ABSTRACT We have examined the role of protein phosphorylation in the modulation of the key muscle-specific transcription factor MyoD. We show that MyoD is highly phosphorylated in growing myoblasts and undergoes substantial dephosphorylation during differentiation. MyoD can be efficiently phosphorylated in vitro by either purified cdk1-cyclin B or cdk1 and cdk2 immunoprecipitated from proliferative myoblasts. Comparative two-dimensional tryptic phosphopeptide mapping combined with site-directed mutagenesis revealed that cdk1 and cdk2 phosphorylate MyoD on serine 200 in proliferative myoblasts. In addition, when the seven proline-directed sites in MyoD were individually mutated, only substitution of serine 200 to a nonphosphorylatable alanine (MyoD-Ala200) abolished the slower-migrating hyperphosphorylated form of MyoD, seen either in vitro after phosphorylation by cdk1-cyclin B or in vivo following overexpression in 10T1/2 cells. The MyoD-Ala200 mutant displayed activity threefold higher than that of wild-type MyoD in transactivation of an E-box-dependent reporter gene and promoted markedly enhanced myogenic conversion and fusion of 10T1/2 fibroblasts into muscle cells. In addition, the half-life of MyoD-Ala200 protein was longer than that of wild-type MyoD, substantiating a role of Ser200 phosphorylation in regulating MyoD turnover in proliferative myoblasts. Taken together, our data show that direct phosphorylation of MyoD Ser200 by cdk1 and cdk2 plays an integral role in compromising MyoD activity during myoblast proliferation.

S100A10 regulates plasminogen-dependent macrophage invasion

Blood ◽  
2010 ◽  
Vol 116 (7) ◽  
pp. 1136-1146 ◽  
Author(s):  
Paul A. O'Connell ◽  
Alexi P. Surette ◽  
Robert S. Liwski ◽  
Per Svenningsson ◽  
David M. Waisman
Keyword(s):  
Cell Surface Receptor ◽  
Macrophage Migration ◽  
Plasminogen Activation System ◽  
Inflammatory Stimuli ◽  
Integral Role ◽  
Surface Receptor ◽  
First Time

Abstract The plasminogen activation system plays an integral role in the migration of macrophages in response to an inflammatory stimulus, and the binding of plasminogen to its cell-surface receptor initiates this process. Although previous studies from our laboratory have shown the importance of the plasminogen receptor S100A10 in cancer cell plasmin production, the potential role of this protein in macrophage migration has not been investigated. Using thioglycollate to induce a peritoneal inflammatory response, we demonstrate, for the first time, that compared with wild-type (WT) mice, macrophage migration across the peritoneal membrane into the peritoneal cavity in S100A10-deficient (S100A10−/−) mice was decreased by up to 53% at 24, 48, and 72 hours. Furthermore, the number of S100A10-deficient macrophages that infiltrated Matrigel plugs was reduced by 8-fold compared with their WT counterpart in vivo. Compared with WT macrophages, macrophages from S100A10−/− mice demonstrated a 50% reduction in plasmin-dependent invasion across a Matrigel barrier and a 45% reduction in plasmin generation in vitro. This loss in plasmin-dependent invasion was in part the result of a decreased generation of plasmin and a decreased activation of pro-MMP-9 by S100A10-deficient macrophages. This study establishes a direct involvement of S100A10 in macrophage recruitment in response to inflammatory stimuli.

Abstract 3717: Receptor for Advanced Glycation End Products (RAGE) Plays an Integral Role in Non-Diabetic Atherosclerosis and Oxidized LDL Stimulation

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Hironori Uekita ◽  
Toshiyuki Ishibashi ◽  
Masashi Shiomi ◽  
Koichi Sugimoto ◽  
Hiroshi Ohkawara ◽  
...  
Keyword(s):  
Oxidized Ldl ◽  
In Vitro Study ◽  
Vascular Responses ◽  
Integral Role ◽  
High Concentrations ◽  
Rage Expression ◽  
Pai 1

Background: RAGE is a multifunctional receptor which identifies AGE, S100/calgranulins and HMGB-1 as the ligands. An AGE/RAGE axis plays a central role in the pathogenesis in diabetic vascular remodeling. However, the issue that hyperlipidemia associated with oxidized LDL mediates vascular responses via RAGE remains to be elucidated. In this study, we attempted to clarify the role of RAGE in non-diabetic atherosclerosis and oxidized LDL (ox-LDL) stimulation. Methods and Results: We used the aortic and coronary atherosclerotic lesions of Watanabe heritable hyperlipidemic (WHHL) rabbits at ages of 1 to 14 months, which had high concentrations of serum ox-LDL independent of aging. Immunohistochemistry demonstrated the significant expression of RAGE as early as at age of 1 month with the stronger expression at 3 and 7 months, which was diminished at ages of 14 months. The major original sources of RAGE expression were macrophages and endothelial cells, as well as smooth muscle cells. The concentrations of serum AGE did not alter significantly with aging, while there was no difference in serum AGE level between WHHL rabbits and control New Zealand White rabbits. These data suggest the integral role of RAGE in the initiation and progression of non-diabetic atherosclerosis associated with hyperlipidemia. We further investigated the relevance of RAGE expression in a monocyte/macrophage lineage. Fluorescent immunohistochemistry and Western blotting showed the expression of RAGE on plasma membrane in isolated human peripheral monocytes, with the stronger expression in cultured monocyte-derived macrophages. Inhibition of RAGE by siRNA suppressed AGE-induced MCP-1, MMP-9 and PAI-1 expression in cultured human macrophages. Inhibition of RAGE did not significantly suppress the incorporation of DiI-labeled oxidized LDL in monocyte-derived macrophage by fluorescent study. However, oxidized LDL- triggered MCP-1, MMP-9 and PAI-1 expression was attenuated by inhibition of RAGE. Conclusions: Our in vivo and in vitro study shows that RAGE plays an integral role in the initiation and development of atherosclerosis independent of diabetes and that ox-LDL mediates vascular responses via RAGE.

Self‐assembled peptide hydrogel scaffolds with VEGF and BMP‐2 enhanced in vitro angiogenesis and osteogenesis

Oral Diseases ◽  
2021 ◽  
Author(s):  
Ruijuan Zhang ◽  
Yang Liu ◽  
Yingqiu Qi ◽  
Ying Zhao ◽  
Guangjun Nie ◽  
...  
Keyword(s):  
Hydrogel Scaffolds ◽  
Self Assembled ◽  
In Vitro Angiogenesis ◽  
Peptide Hydrogel

scholarly journals Interactions between non-structured domains of FG- and non-FG-nucleoporins coordinate the ordered assembly of the nuclear pore complex in mitosis

2018 ◽  
Author(s):  
Hide A. Konishi ◽  
Shige H. Yoshimura
Keyword(s):  
Nuclear Pore Complex ◽  
Nuclear Pore ◽  
Middle Stage ◽  
Selective Channel ◽  
Sequential Addition ◽  
Ordered Assembly ◽  
Self Assembled

SummaryIn this study, we examined how channel-forming subunits of the nuclear pore complex (NPC) are assembled into a selective channel within a highly structured scaffold ring during post-mitotic assembly. We focused on non-structured domains of the scaffold Nups and performed in vitro self-assembled particle assays with those derived from channel-forming FG-Nups. We found that non-structured domains of ELYS and Nup35N interacted with channel-forming FG-Nups to form a self-assembled particle. Sequential addition of FG-Nups into the scaffold particle revealed that ELYS, which initiates post-mitotic NPC reassembly, interacts with early assembling FG-Nups (Nups98 and 153) but not middle stage-assembling FG-Nups (Nups58 and 62). Nup35, which assembles between the early and middle stages, facilitated the assembly of Nup62 into the early assembling Nups both in vitro and in vivo. These results demonstrate that ELYS and Nup35 have a role of facilitator in the ordered assembly of channel-forming FG-Nups during mitosis.

The role of silicon in forages: A quantitative X-Ray study

1987 ◽  
Vol 45 ◽  
pp. 416-417
Author(s):  
Janet H. Woodward ◽  
D. E. Akin
Keyword(s):  
Sodium Acetate ◽  
Dry Matter ◽  
Acetate Buffer ◽  
Plant Tissues ◽  
Sodium Acetate Buffer ◽  
X Ray ◽  
Dry Matter Digestibility ◽  
Percent Composition

Silicon (Si) is distributed throughout plant tissues, but its role in forages has not been clarified. Although Si has been suggested as an antiquality factor which limits the digestibility of structural carbohydrates, other research indicates that its presence in plants does not affect digestibility. We employed x-ray microanalysis to evaluate Si as an antiquality factor at specific sites of two cultivars of bermuda grass (Cynodon dactvlon (L.) Pers.). “Coastal” and “Tifton-78” were chosen for this study because previous work in our lab has shown that, although these two grasses are similar ultrastructurally, they differ in in vitro dry matter digestibility and in percent composition of Si.Two millimeter leaf sections of Tifton-7 8 (Tift-7 8) and Coastal (CBG) were incubated for 72 hr in 2.5% (w/v) cellulase in 0.05 M sodium acetate buffer, pH 5.0. For controls, sections were incubated in the sodium acetate buffer or were not treated.

An integrated screening method for evaluating the pulmonary toxicity of inhaled particulates: Role of microscopic techniques in assessing pulmonary macrophage clearance functions

1990 ◽  
Vol 48 (3) ◽  
pp. 826-827
Author(s):  
David B. Warheit ◽  
Lena Achinko ◽  
Mark A. Hartsky
Keyword(s):  
Bronchoalveolar Lavage ◽  
Pulmonary Toxicity ◽  
Screening Method ◽  
Pulmonary Response ◽  
Inhaled Particles ◽  
Cytochemical Analysis ◽  
Pulmonary Macrophages ◽  
Integrated Screening

There is a great need for the development of a rapid and reliable bioassay to evaluate the pulmonary toxicity of inhaled particles. A number of methods have been proposed, including lung clearance studies, bronchoalveolar lavage analysis, and in vitro cytotoxicity tests. These methods are often limited in scope inasmuch as they measure only one dimension of the pulmonary response to inhaled, instilled or incubated dusts. Accordingly, a comprehensive approach to lung toxicity studies has been developed.To validate the method, rats were exposed for 6 hours or 3 days to various concentrations of either aerosolized alpha quartz silica (Si) or carbonyl iron (CI) particles. Cells and fluids from groups of sham and dust-exposed animals were recovered by bronchoalveolar lavage (BAL). Alkaline phosphatase, LDH and protein values were measured in BAL fluids at several time points postexposure. Cells were counted and evaluated for viability, as well as differential and cytochemical analysis. In addition, pulmonary macrophages (PM) were cultured and studied for morphology, chemotaxis, and phagocytosis by scanning electron microscopy.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

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