scholarly journals Role of Curing Temperature of Poly(Glycerol Sebacate) Substrates on Protein-Cell Interaction and Early Cell Adhesion

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 382
Author(s):  
Rubén Martín-Cabezuelo ◽  
José Carlos Rodríguez-Hernández ◽  
Guillermo Vilariño-Feltrer ◽  
Ana Vallés-Lluch

A novel procedure to obtain smooth, continuous polymeric surfaces from poly(glycerol sebacate) (PGS) has been developed with the spin-coating technique. This method proves useful for separating the effect of the chemistry and morphology of the networks (that can be obtained by varying the synthesis parameters) on cell-protein-substrate interactions from that of structural variables. Solutions of the PGS pre-polymer can be spin-coated, to then be cured. Curing under variable temperatures has been shown to lead to PGS networks with different chemical properties and topographies, conditioning their use as a biomaterial. Particularly, higher synthesis temperatures yield denser networks with fewer polar terminal groups available on the surface. Material-protein interactions were characterised by using extracellular matrix proteins such as fibronectin (Fn) and collagen type I (Col I), to unveil the biological interface profile of PGS substrates. To that end, atomic force microscopy (AFM) images and quantification of protein adsorbed in single, sequential and competitive protein incubations were used. Results reveal that Fn is adsorbed in the form of clusters, while Col I forms a characteristic fibrillar network. Fn has an inhibitory effect when incubated prior to Col I. Human umbilical endothelial cells (HUVECs) were also cultured on PGS surfaces to reveal the effect of synthesis temperature on cell behaviour. To this effect, early focal adhesions (FAs) were analysed using immunofluorescence techniques. In light of the results, 130 °C seems to be the optimal curing temperature since a preliminary treatment with Col I or a Fn:Col I solution facilitates the formation of early focal adhesions and growth of HUVECs.

1993 ◽  
Vol 264 (4) ◽  
pp. G589-G595 ◽  
Author(s):  
D. A. Brenner ◽  
J. Westwick ◽  
M. Breindl

Cirrhosis is characterized by an increased deposition of extracellular matrix proteins, including type I collagen. Type I collagen is a product of two genes, alpha 1(I) and alpha 2(I), which are generally coordinately regulated. Since expression of type I collagen genes is increased during cirrhosis, understanding the structure and function of the regulatory components of the type I collagen genes should provide insight into the molecular pathogenesis of cirrhosis. This review will analyze the collagen alpha 1(I) gene with respect to chromatin structure, DNA methylation, regulation by agonists, and DNA-protein interactions.


1993 ◽  
Vol 293 (1) ◽  
pp. 263-267 ◽  
Author(s):  
P S Wright ◽  
V Saudek ◽  
T J Owen ◽  
S L Harbeson ◽  
A J Bitonti

Integrin binding to proteins often involves recognition of domains containing the arginine-glycine-aspartate (RGD) motif. Different binding affinities and specificities of the integrin-ligand protein interactions involve additional protein domains. The n.m.r. structure of the snake-venom protein echistatin suggested that the C-terminal portion of the molecule might be important, in addition to the RGD domain, in binding to the integrin glycoprotein IIbIIIa (GPIIbIIIa) [Saudek, Atkinson and Pelton (1991) Biochem. 30, 7369-7372]. The synthetic C-terminal peptide, echistatin-(40-49), PRNPHKGPAT, (1) inhibited binding of GPIIbIIIa to immobilized echistatin (IC50 3-6 mM), but did not inhibit binding of GPIIbIIIa to immobilized fibrinogen (up to 5 mM peptide), (2) activated GPIIbIIIa binding to fibronectin and vitronectin, usual ligands for the activated integrin, (3) activated binding of GPIIbIIIa to collagen type I and type IV, proteins not usually regarded as ligands for the integrin, and (4) stimulated 125I-fibrinogen binding by human platelets. These findings argue for an interaction of this non-RGD domain in echistatin with GPIIbIIIa, leading to activation of the integrin and extension of the ligand specificity to include immobilized collagen.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Jinglue Song ◽  
Hongli Liu ◽  
Qi Zhu ◽  
Yutong Miao ◽  
Feiyan Wang ◽  
...  

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease characterized by bone loss. Degree of inflammation has been identified as an important initiator of skeletal damage in RA. Iguratimod (T-614) is an anti-inflammatory agent which has been reported to show the inhibitory effect of bone destruction in RA. However, the role of T-614 in osteoblast differentiation is still not clear. In this study, we intended to find the effect of T-614 on the osteogenesis process. We detected osteogenesis markers and transcription factors associated with osteoblastic lineage and bone formation in the culture of mesenchymal stem cells which differentiate osteoblast. The contents and activity of alkaline phosphatase, levels of collagen type I and bone gla protein, and calcium nodule formation were increased significantly after T-614 treated. Meanwhile, the mRNAs expressions of Osterix and Dlx5 were also found to be increased significantly by real-time PCR. The changes of levels of phosphorylation of p38 and NF-κB were also detected by Western blot. The results showed that T-614 promotes osteoblastic differentiation by increasing the expression of Osterix and Dlx5 and increasing the activation of P38. T-614 could advance the ectopic expression of NF-κB to suppress inflammation, which indirectly inhibits the damage of the osteoblasts.


Animals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 863 ◽  
Author(s):  
Ana Amaral ◽  
Carina Fernandes ◽  
Maria Rosa Rebordão ◽  
Anna Szóstek-Mioduchowska ◽  
Karolina Lukasik ◽  
...  

Neutrophil extracellular traps (NETs) fight endometritis, and elastase (ELA), a protease found in NETs, might induce collagen type I (COL1) accumulation in equine endometrium. Metallopeptidases (MMPs) are involved in extracellular matrix balance. The aim was to evaluate the effects of ELA and sivelestat (selective elastase inhibitor) on MMP-2 and MMP-9 expression and gelatinolytic activity, as well as the potential inhibitory effect of sivelestat on ELA-induced COL1 in equine endometrium. Endometrial explants from follicular (FP) and mid-luteal (MLP) phases were treated for 24 or 48 h with ELA, sivelestat, and their combination. Transcripts of COL1A2, MMP2, and MMP9 were evaluated by qPCR; COL1 protein relative abundance by Western blot, and MMP-2 and MMP-9 gelatinolytic activity by zymography. In response to ELA treatment, there was an increase in MMP2 mRNA transcription (24 h) in active MMP-2 (48 h), both in FP, and in MMP9 transcripts in FP (48 h) and MLP (24 h) (p < 0.05). Sivelestat inhibited ELA-induced COL1A2 transcripts in FP (24 h) and MLP (24 h, 48 h) (p < 0.05). The sivelestat inhibitory effect was detected in MMP9 transcripts in FP at 48 h (p < 0.05), but proteases activity was unchanged. Thus, MMP-2 and MMP-9 might be implicated in endometrium fibrotic response to ELA. In mare endometrium, sivelestat may decrease ELA-induced COL1 deposition and hinder endometrosis development.


2021 ◽  
Vol 12 ◽  
Author(s):  
Paulina Villar-Fincheira ◽  
Aaron J. Paredes ◽  
Tomás Hernández-Díaz ◽  
Ignacio Norambuena-Soto ◽  
Nicole Cancino-Arenas ◽  
...  

Little is known about the effects of training load on exercise-induced plasma increase of interleukin-6 (IL-6) and soluble IL-6 receptor (sIL-6R) and their relationship with vascular remodeling. We sought to evaluate the role of sIL 6R as a regulator of IL-6-induced vascular remodeling. Forty-four male marathon runners were recruited and allocated into two groups: low-training (LT, &lt;100 km/week) and high-training (HT, ≥100 km/week), 22 athletes per group. Twenty-one sedentary participants were used as reference. IL-6, sIL-6R and sgp130 levels were measured in plasma samples obtained before and immediately after finishing a marathon (42.2-km). Aortic diameter was measured by echocardiography. The inhibitory effect of sIL-6R on IL-6-induced VSMC migration was assessed using cultured A7r5 VSMCs. Basal plasma IL-6 and sIL-6R levels were similar among sedentary and athlete groups. Plasma IL-6 and sIL-6R levels were elevated after the marathon, and HT athletes had higher post-race plasma sIL-6R, but not IL-6, level than LT athletes. No changes in sgp130 plasma levels were found in LT and HT groups before and after running the marathon. Athletes had a more dilated ascending aorta and aortic root than sedentary participants with no differences between HT and LT athletes. However, a positive correlation between ascending aorta diameter and plasma IL-6 levels corrected by training load and years of training was observed. IL-6 could be responsible for aorta dilation because IL-6 stimulated VSMC migration in vitro, an effect that is inhibited by sIL-6R. However, IL-6 did not modify cell proliferation, collagen type I and contractile protein of VSMC. Our results suggest that exercise induces vascular remodeling. A possible association with IL-6 is proposed. Because sIL-6R inhibits IL-6-induced VSMC migration, a possible mechanism to regulate IL-6-dependent VSMC migration is also proposed.


2020 ◽  
Author(s):  
Salvador Guardiola ◽  
Monica Varese ◽  
Xavier Roig ◽  
Jesús Garcia ◽  
Ernest Giralt

<p>NOTE: This preprint has been retracted by consensus from all authors. See the retraction notice in place above; the original text can be found under "Version 1", accessible from the version selector above.</p><p><br></p><p>------------------------------------------------------------------------</p><p><br></p><p>Peptides, together with antibodies, are among the most potent biochemical tools to modulate challenging protein-protein interactions. However, current structure-based methods are largely limited to natural peptides and are not suitable for designing target-specific binders with improved pharmaceutical properties, such as macrocyclic peptides. Here we report a general framework that leverages the computational power of Rosetta for large-scale backbone sampling and energy scoring, followed by side-chain composition, to design heterochiral cyclic peptides that bind to a protein surface of interest. To showcase the applicability of our approach, we identified two peptides (PD-<i>i</i>3 and PD-<i>i</i>6) that target PD-1, a key immune checkpoint, and work as protein ligand decoys. A comprehensive biophysical evaluation confirmed their binding mechanism to PD-1 and their inhibitory effect on the PD-1/PD-L1 interaction. Finally, elucidation of their solution structures by NMR served as validation of our <i>de novo </i>design approach. We anticipate that our results will provide a general framework for designing target-specific drug-like peptides.<i></i></p>


2020 ◽  
Author(s):  
Salvador Guardiola ◽  
Monica Varese ◽  
Xavier Roig ◽  
Jesús Garcia ◽  
Ernest Giralt

<p>NOTE: This preprint has been retracted by consensus from all authors. See the retraction notice in place above; the original text can be found under "Version 1", accessible from the version selector above.</p><p><br></p><p>------------------------------------------------------------------------</p><p><br></p><p>Peptides, together with antibodies, are among the most potent biochemical tools to modulate challenging protein-protein interactions. However, current structure-based methods are largely limited to natural peptides and are not suitable for designing target-specific binders with improved pharmaceutical properties, such as macrocyclic peptides. Here we report a general framework that leverages the computational power of Rosetta for large-scale backbone sampling and energy scoring, followed by side-chain composition, to design heterochiral cyclic peptides that bind to a protein surface of interest. To showcase the applicability of our approach, we identified two peptides (PD-<i>i</i>3 and PD-<i>i</i>6) that target PD-1, a key immune checkpoint, and work as protein ligand decoys. A comprehensive biophysical evaluation confirmed their binding mechanism to PD-1 and their inhibitory effect on the PD-1/PD-L1 interaction. Finally, elucidation of their solution structures by NMR served as validation of our <i>de novo </i>design approach. We anticipate that our results will provide a general framework for designing target-specific drug-like peptides.<i></i></p>


2020 ◽  
Author(s):  
Salvador Guardiola ◽  
Monica Varese ◽  
Xavier Roig ◽  
Jesús Garcia ◽  
Ernest Giralt

<p>NOTE: This preprint has been retracted by consensus from all authors. See the retraction notice in place above; the original text can be found under "Version 1", accessible from the version selector above.</p><p><br></p><p>------------------------------------------------------------------------</p><p><br></p><p>Peptides, together with antibodies, are among the most potent biochemical tools to modulate challenging protein-protein interactions. However, current structure-based methods are largely limited to natural peptides and are not suitable for designing target-specific binders with improved pharmaceutical properties, such as macrocyclic peptides. Here we report a general framework that leverages the computational power of Rosetta for large-scale backbone sampling and energy scoring, followed by side-chain composition, to design heterochiral cyclic peptides that bind to a protein surface of interest. To showcase the applicability of our approach, we identified two peptides (PD-<i>i</i>3 and PD-<i>i</i>6) that target PD-1, a key immune checkpoint, and work as protein ligand decoys. A comprehensive biophysical evaluation confirmed their binding mechanism to PD-1 and their inhibitory effect on the PD-1/PD-L1 interaction. Finally, elucidation of their solution structures by NMR served as validation of our <i>de novo </i>design approach. We anticipate that our results will provide a general framework for designing target-specific drug-like peptides.<i></i></p>


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