scholarly journals Transforming growth factor-β1 induces differentiation of rainbow trout (Oncorhynchus mykiss) cardiac fibroblasts into myofibroblasts

2018 ◽  
Vol 221 (24) ◽  
pp. jeb189167 ◽  
Author(s):  
Elizabeth F. Johnston ◽  
Todd E. Gillis
Keyword(s):  
Rainbow Trout ◽  
Growth Factor ◽  
Oncorhynchus Mykiss ◽  
Transforming Growth Factor ◽  
Cardiac Fibroblasts ◽  
Transforming Growth Factor Β1 ◽  
Rainbow Trout Oncorhynchus Mykiss

Insulin and insulin-like growth factor I signaling pathways in rainbow trout (Oncorhynchus mykiss) during adipogenesis and their implication in glucose uptake

2010 ◽  
Vol 299 (1) ◽  
pp. R33-R41 ◽  
Author(s):  
L. Bouraoui ◽  
E. Capilla ◽  
J. Gutiérrez ◽  
I. Navarro
Keyword(s):  
Rainbow Trout ◽  
Growth Factor ◽  
Oncorhynchus Mykiss ◽  
Glucose Uptake ◽  
Signaling Pathways ◽  
Mapk Phosphorylation ◽  
Factor I ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Igf I ◽  
Stimulation Of

Primary cultures of rainbow trout ( Oncorhynchus mykiss ) adipocytes were used to examine the main signaling pathways of insulin and insulin-like growth factor I (IGF-I) during adipogenesis. We first determined the presence of IGF-I receptors (IGF-IR) and insulin receptors (IR) in trout preadipocytes ( day 5) and adipocytes ( day 14). IGF-IRs were more abundant and appeared to be in higher levels in differentiated cells than in preadipocytes, whereas IRs were detected in lower but constant levels throughout the culture. The cells were immunoreactive against ERK1/2 MAPK, and AKT/PI3K, components of the two main signal transduction pathways for insulin and IGF-I receptors. Stimulation of MAPK phosphorylation by IGF-I was higher in preadipocytes than in adipocytes, while no effects were observed in MAPK phosphorylation after incubation of cells with insulin. AKT phosphorylation increased in the presence of both insulin and IGF-I, with higher levels of stimulation in adipocytes than in preadipocytes. Activation of both pathways was blocked by the use of specific inhibitors of MAPK (PD98059) and AKT (wortmannin). We describe here, for the first time, the effects of IGF-I and insulin on 2-deoxyglucose uptake in primary culture of trout adipocytes. IGF-I was more potent in stimulating glucose uptake than insulin, and PD98059 and wortmannin inhibited the stimulation of glucose uptake by this growth factor, suggesting that IGF-I plays an important metabolic role in trout adipocytes. Our results suggest that differential activation of the MAPK and AKT pathways are involved in the IGF-I- and insulin-induced effects of trout adipocytes during the various stages of adipogenesis.

Upregulation of α8β1-integrin in cardiac fibroblast by angiotensin II and transforming growth factor-β1

2001 ◽  
Vol 281 (5) ◽  
pp. C1457-C1467 ◽  
Author(s):  
Gaétan Thibault ◽  
Marie-Josée Lacombe ◽  
Lynn M. Schnapp ◽  
Alexandre Lacasse ◽  
Fatiha Bouzeghrane ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Growth Factor ◽  
Matrix Protein ◽  
Transforming Growth Factor ◽  
Cardiac Fibroblasts ◽  
Transforming Growth Factor Β1 ◽  
Cardiac Fibroblast ◽  
Extracellular Matrix Protein ◽  
Ang Ii ◽  
Tgf Β1

Using a novel pharmacological tool with125I-echistatin to detect integrins on the cell, we have observed that cardiac fibroblasts harbor five different RGD-binding integrins: α8β1, α3β1, α5β1, αvβ1, and αvβ3. Stimulation of cardiac fibroblasts by angiotensin II (ANG II) or transforming growth factor-β1 (TGF-β1) resulted in an increase of protein and heightening by 50% of the receptor density of α8β1-integrin. The effect of ANG II was blocked by an AT1, but not an AT2, receptor antagonist, or by an anti-TGF-β1 antibody. ANG II and TGF-β1 increased fibronectin secretion, smooth muscle α-actin synthesis, and formation of actin stress fibers and enhanced attachment of fibroblasts to a fibronectin matrix. The α8- and β1-subunits were colocalized by immunocytochemistry with vinculin or β3-integrin at focal adhesion sites. These results indicate that α8β1-integrin is an abundant integrin on rat cardiac fibroblasts. Its positive modulation by ANG II and TGF-β1 in a myofibroblast-like phenotype suggests the involvement of α8β1-integrin in extracellular matrix protein deposition and cardiac fibroblast adhesion.

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