scholarly journals The control of cellular shape and motility. Mg2+ and tropomyosin regulate the formation and the dissociation of microfilament bundles

1992 ◽  
Vol 288 (3) ◽  
pp. 727-732 ◽  
Author(s):  
E Grazi ◽  
P Cuneo ◽  
A Cataldi
Keyword(s):  
Ethylene Glycol ◽  
Actin Filaments ◽  
Adenine Nucleotide ◽  
Energy Charge ◽  
Poly Ethylene Glycol ◽  
Microfilament Bundles ◽  
Filament Bundles ◽  
Poly Ethylene

At pH 7.14 and 37 degrees C, in 7.2% (w/v) poly(ethylene glycol) 6000, tropomyosin-regulated actin filaments are converted into filament bundles by increasing the free Mg2+ concentration to 1.7-2.0 mM. When free Mg2+ concentration is decreased below 1.7 mM, bundles dissociate back into tropomyosin-regulated actin filaments. Pure actin filaments are insensitive to this mechanism of control and are found as filament bundles in all the range of free Mg2+ concentrations tested (1.37-2.2 mM). The mechanism of regulation described above is likely to operate in the cell, where the concentration of free Mg2+ is linked to the energy charge of the adenine nucleotide system.

scholarly journals ‘Macromolecular crowding’ is a primary factor in the organization of the cytoskeleton

1992 ◽  
Vol 281 (2) ◽  
pp. 507-512 ◽  
Author(s):  
P Cuneo ◽  
E Magri ◽  
A Verzola ◽  
E Grazi
Keyword(s):  
Ethylene Glycol ◽  
Actin Filaments ◽  
Macromolecular Crowding ◽  
Cytoskeletal Proteins ◽  
Primary Factor ◽  
Poly Ethylene Glycol ◽  
Experimental Conditions ◽  
Actin Bundles ◽  
Poly Ethylene

We propose that, in the cell, the reversible conversion of actin filaments into actin bundles is controlled by the concentration of the macromolecules [we have employed poly(ethylene glycol) 6000 to mimic the macromolecules of the cell] as well as by the nature of the ancillary cytoskeletal proteins that decorate actin filaments. The proposal is based on the following evidence. (1) Under our experimental conditions the transition from filaments into bundles occurs at increasing concentrations of poly(ethylene glycol), with the following sequence: caldesmon-actin, 3%; filamin-actin, 4-5%; caldesmon-tropomyosin-actin, 5-7%; actin, 6-7%; tropomyosin-actin, 9-10%. (2) Under conditions of low osmoelastic stress [3% poly(ethylene glycol)], preformed caldesmon-actin bundles are dissociated by the addition of either tropomyosin or tropomyosin-decorated actin. The dissociation of the bundles promoted by the addition of tropomyosin-decorated actin is faster than that promoted by the addition of tropomyosin.

PIEZOELECTRIC PROPERTIES OF POLY(3-HYDROXYBUTYRATE-CO-3-HEDROXYBUTYRATE)-CO-POLY(ETHYLENE GLYCOL) PRODUCED BY CONTROLLED MICROBIOLOGICAL BIOSYNTHESIS

2019 ◽  
Vol 10 (10) ◽  
Author(s):  
Anton Bonartsev ◽  
Vera Voinova ◽  
Elizaveta Akoulina ◽  
Andrey Dudun ◽  
Irina Zharkova ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Piezoelectric Properties ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene

Thermosensitives hydrogels based on poly (ethylene glycol): I. Synthesis, characterization and release

2007 ◽  
Vol 32 (5) ◽  
pp. 431-446 ◽  
Author(s):  
Tahar Bartil ◽  
Mahmoud Bounekhel ◽  
Cedric Calberg ◽  
Robert Jerome
Keyword(s):  
Ethylene Glycol ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene

Quantifying Heart Valve Interstitial Cell Contractile State Using Highly Tunable Poly(Ethylene Glycol) Hydrogels

2019 ◽  
Author(s):  
Alex Khang ◽  
Andrea Gonzalez Rodriguez ◽  
Megan E. Schroeder ◽  
Jacob Sansom ◽  
Emma Lejeune ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Heart Valve ◽  
Interstitial Cell ◽  
Poly Ethylene Glycol ◽  
Contractile State ◽  
Poly Ethylene

Tissue Distribution and Systemic Toxicity Evaluation of Raloxifene Targeted Polymeric Micelles of Poly (Styrene-Maleic Acid)-Poly (Amide- Ether-Ester-Imide)-Poly (Ethylene Glycol) Loaded With Docetaxel in Breast Cancer Bearing Mice

2019 ◽  
Vol 14 (3) ◽  
pp. 280-291 ◽  
Author(s):  
Jaleh Varshosaz ◽  
Farshid Hassanzadeh ◽  
Batool Hashemi-Beni ◽  
Mohsen Minaiyan ◽  
Saeedeh Enteshari
Keyword(s):  
Side Effects ◽  
Antitumor Activity ◽  
Ethylene Glycol ◽  
Tissue Distribution ◽  
Tumor Cells ◽  
Maleic Acid ◽  
Polymeric Micelles ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene ◽  
Ether Ester

Background: Due to the low water solubility of Docetaxel (DTX), it is formulated with ethanol and Tween 80 with lots of side effects. For this reason, special attention has been paid to formulate it in new drug nano-carriers. Objective: The goal of this study was to evaluate the safety, antitumor activity and tissue distribution of the novel synthesized Raloxifene (RA) targeted polymeric micelles. Methods: DTX-loaded RA-targeted polymeric micelles composed of poly(styrene-maleic acid)- poly(amide-ether-ester-imide)-poly(ethylene glycol) (SMA-PAEE-PEG) were prepared and their antitumor activity was studied in MC4-L2 tumor-bearing mice compared with non-targeted micelles and free DTX. Safety of the micelles was studied by Hematoxylin and Eosin (H&E) staining of tumors and major organs of the mice. The drug accumulation in the tumor and major organs was measured by HPLC method. Results: The results showed better tumor growth inhibition and increased survival of mice treated with DTX-loaded in targeted micelles compared to the non-targeted micelles and free DTX. Histopathological studies, H&E staining of tumors and immunohistochemical examination showed the potential of DTX-loaded RA-targeted micelles to inhibit tumor cells proliferation. The higher accumulation of the DTX in the tumor tissue after injection of the micelles compared to the free DTX may indicate the higher uptake of the targeted micelles by the G-Protein-Coupled Estrogen Receptors (GPER). Conclusion: The results indicate that RA-conjugated polymeric micelles may be a strong and effective drug delivery system for DTX therapy and uptake of the drug into tumor cells, and overcome the disadvantages and side effects of conventional DTX.

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