scholarly journals Structural consequences of transforming growth factor beta-1 activation from near-therapeutic X-ray doses

2019 ◽  
Vol 26 (4) ◽  
pp. 967-979 ◽  
Author(s):  
Timothy Stachowski ◽  
Thomas D. Grant ◽  
Edward H. Snell
Keyword(s):  
Growth Factor ◽  
Radiation Damage ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Bound State ◽  
Activation Process ◽  
Inhibitory Protein ◽  
X Ray ◽  
Growth Factor Beta ◽  
Complementary Techniques

Dissociation of transforming growth factor beta-1 (TGFβ-1) from the inhibitory protein latency-associated peptide (LAP) can occur from low doses of X-ray irradiation of the LAP–TGFβ-1 complex, resulting in the activation of TGFβ-1, and can have health-related consequences. Using the tools and knowledge developed in the study of radiation damage in the crystallographic setting, small-angle X-ray scattering (SAXS) and complementary techniques suggest an activation process that is initiated but not driven by the initial X-ray exposure. LAP is revealed to be extended when not bound to TGFβ-1 and has a different structural conformation compared to the bound state. These studies pave the way for the structural understanding of systems impacted at therapeutic X-ray doses and show the potential impact of radiation damage studies beyond their original intent.

scholarly journals Transforming growth factor beta 1 expression and inflammatory cells in tooth extraction socket after X-ray irradiation

2017 ◽  
Vol 49 (2) ◽  
pp. 87
Author(s):  
Ramadhan Hardani Putra ◽  
Eha Renwi Astuti ◽  
Rini Devijanti Ridwan
Keyword(s):  
Growth Factor ◽  
Treatment Group ◽  
Transforming Growth Factor Beta ◽  
Tooth Extraction ◽  
Transforming Growth Factor ◽  
Inflammatory Cells ◽  
Radiographic Examination ◽  
Control Group ◽  
X Ray ◽  
Growth Factor Beta

Background: Radiographic examination is often used in dentistry to evaluate tooth extraction complications. X-ray used in radiographic examination, however, has negative effects, including damage to DNA and inflammatory response during wound healing process. Purpose: This study aimed to analyze the effects of X-ray irradiation on transforming growth factor beta 1 (TGF-ß1) expression and number of inflammatory cells in tooth extraction sockets. Method: Thirty rats were divided into three groups, which consist of control group (with a radiation of 0 mSv), treatment group 1 (with a radiation of 0.08 mSv), and treatment group 2 (with a radiation of 0.16 mSv). These rats in each group were sacrificed on days 3 and 5 after treatment. Inflammatory cells which were observed in this research were PMN, macrophages, and lymphocytes. Histopathological and immunohistochemical examinations were used to calculate the number of inflammatory cells and TGF-ß1 expression. Obtained data were analyzed using SPSS 16.0 software with one way ANOVA and Tukey’s HSD tests. Result: There was no significant decrease in the number of PMN. On the other hand, there were significant decreases in the number of macrophages and lymphocytes in the sacrificed group on day-5 with the radiation of 0.16 mSv. Similarly, the most significant decreased expression of TGF-ß1 was found in the group sacrificed on day 5 with the radiation of 0.16 mSv. Conclusion: X-ray irradiation with 0.08 mSv and 0.16 mSv doses can decrease TGF-ß1 expression and number of inflammatory cells in tooth extraction sockets on day 3 and 5 post extraction.

scholarly journals Requirement for transglutaminase in the activation of latent transforming growth factor-beta in bovine endothelial cells.

1993 ◽  
Vol 121 (2) ◽  
pp. 439-448 ◽  
Author(s):  
S Kojima ◽  
K Nara ◽  
D B Rifkin
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Direct Action ◽  
Neutralizing Antibody ◽  
Activation Process ◽  
Type Ii ◽  
Tgf Beta ◽  
Growth Factor Beta

A hitherto unknown function for transglutaminase (TGase; R-glutaminyl-peptide: amine gamma-glutamyltransferase, EC 2.3.2.13) was found in the conversion of latent transforming growth factor-beta (LTGF-beta) to active TGF-beta by bovine aortic endothelial cells (BAECs). The cell-associated, plasmin-mediated activation of LTGF-beta to TGF-beta induced either by treatment of BAECs with retinoids or by cocultures of BAECs and bovine smooth muscle cells (BSMCs) was blocked by seven different inhibitors of TGase as well as a neutralizing antibody to bovine endothelial cell type II TGase. Control experiments indicated that TGase inhibitors and/or a neutralizing antibody to TGase did not interfere with the direct action of TGF-beta, the release of LTGF-beta from cells, or the activation of LTGF-beta by plasmin or by transient acidification. After treatment with retinoids, BAECs expressed increased levels of TGase coordinate with the generation of TGF-beta, whereas BSMCs and bovine embryonic skin fibroblasts, which did not activate LTGF-beta after treatment with retinoids, did not. Furthermore, both TGase inhibitors and a neutralizing antibody to TGase potentiated the effect of retinol in enhancing plasminogen activator (PA) levels in cultures of BAECs by suppressing the TGF-beta-mediated enhancement of PA inhibitor-1 (PAI-1) expression. These results indicate that type II TGase is a component required for cell surface, plasmin-mediated LTGF-beta activation process and that increased expression of TGase accompanies retinoid-induced activation of LTGF-beta.

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