scholarly journals Vertebrate Lonesome Kinase Regulated Extracellular Matrix Protein Phosphorylation, Cell Shape, and Adhesion in Trabecular Meshwork Cells

2017 ◽  
Vol 232 (9) ◽  
pp. 2447-2460 ◽  
Author(s):  
Rupalatha Maddala ◽  
Nikolai P. Skiba ◽  
Ponugoti Vasantha Rao
Bone ◽  
2008 ◽  
Vol 42 (6) ◽  
pp. 1061-1071 ◽  
Author(s):  
Adele L. Boskey ◽  
Stephen B. Doty ◽  
Valery Kudryashov ◽  
Philipp Mayer-Kuckuk ◽  
Rani Roy ◽  
...  

2007 ◽  
Vol 177 (4S) ◽  
pp. 421-422
Author(s):  
Ganka Nikolova ◽  
Christian O. Twiss ◽  
Hane Lee ◽  
Nelson Stanley ◽  
Janet Sinsheimer ◽  
...  

Author(s):  
Aniel Moya-Torres ◽  
Monika Gupta ◽  
Fabian Heide ◽  
Natalie Krahn ◽  
Scott Legare ◽  
...  

Abstract The production of recombinant proteins for functional and biophysical studies, especially in the field of structural determination, still represents a challenge as high quality and quantities are needed to adequately perform experiments. This is in part solved by optimizing protein constructs and expression conditions to maximize the yields in regular flask expression systems. Still, work flow and effort can be substantial with no guarantee to obtain improvements. This study presents a combination of workflows that can be used to dramatically increase protein production and improve processing results, specifically for the extracellular matrix protein Netrin-1. This proteoglycan is an axon guidance cue which interacts with various receptors to initiate downstream signaling cascades affecting cell differentiation, proliferation, metabolism, and survival. We were able to produce large glycoprotein quantities in mammalian cells, which were engineered for protein overexpression and secretion into the media using the controlled environment provided by a hollow fiber bioreactor. Close monitoring of the internal bioreactor conditions allowed for stable production over an extended period of time. In addition to this, Netrin-1 concentrations were monitored in expression media through biolayer interferometry which allowed us to increase Netrin-1 media concentrations tenfold over our current flask systems while preserving excellent protein quality and in solution behavior. Our particular combination of genetic engineering, cell culture system, protein purification, and biophysical characterization permitted us to establish an efficient and continuous production of high-quality protein suitable for structural biology studies that can be translated to various biological systems. Key points • Hollow fiber bioreactor produces substantial yields of homogenous Netrin-1 • Biolayer interferometry allows target protein quantitation in expression media • High production yields in the bioreactor do not impair Netrin-1 proteoglycan quality Graphical abstract


Author(s):  
Normie Aida Mohd Nasir ◽  
Renu Agarwal ◽  
Anna Krasilnikova ◽  
Siti Hamimah Sheikh Abdul Kadir ◽  
Igor Iezhitsa

AbstractObjectivesSteroid-induced ocular hypertension and glaucoma are associated with extracellular matrix remodeling at the trabecular meshwork (TM) of the eye due to reduced secretion of matrix metalloproteinases (MMPs), a family of enzymes regulating extracellular matrix proteolysis. Several biological functions of steroids are known to involve regulation of adenosine A1 receptors (A1AR) and nuclear factor kappa B (NFKB). Since MMPs expression in TM has been shown to be regulated by A1AR as well as transcription factors, it is likely that dexamethasone-induced changes in aqueous humor dynamics involve reduced MMP and A1AR expression and reduced NFKB activation. Hence, the current study investigated the association of dexamethasone-induced reduction in MMP secretion with reduced NFKB activation and A1AR expression.MethodsHuman trabecular meshwork cells (HTMCs) were characterized by estimating myocilin and alpha smooth muscle actin expression and then were treated with dexamethasone 100 nM for 2, 5 and 7 days. The MMP secretion was estimated in culture media using Western blot. Immunocytochemistry (ICC) and ELISA were done to investigate the effect of dexamethasone on NFKB phosphorylation. A1AR expression in HTMCs was determined using Western blot and ELISA.ResultsDexamethasone caused a significant reduction in both MMP-2 and -9 expression compared to untreated group after five and seven days but not after two days of culture. Significantly reduced phosphorylated NFKB and A1AR protein levels were detected in dexamethasone treated compared to vehicle treated HTMCs after five days of culture.ConclusionsDexamethasone reduces MMP-2 and -9 secretion by HTMCs and this effect of dexamethasone is associated with reduced NFKB phosphorylation and A1AR expression.


2002 ◽  
Vol 267 (4) ◽  
pp. 440-446 ◽  
Author(s):  
A. Kapetanopoulos ◽  
F. Fresser ◽  
G. Millonig ◽  
Y. Shaul ◽  
G. Baier ◽  
...  

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