scholarly journals Regulation of insulin mRNA abundance and adenylation: dependence on hormones and matrix substrata.

1986 ◽  
Vol 6 (1) ◽  
pp. 337-341 ◽  
Author(s):  
R Muschel ◽  
G Khoury ◽  
L M Reid
Keyword(s):  
Growth Arrest ◽  
Transient State ◽  
Defined Medium ◽  
Mrna Levels ◽  
Insulinoma Cell ◽  
Threefold Increase ◽  
Hormonally Defined Medium ◽  
Insulin Mrna ◽  
Insulinoma Cell Lines ◽  
Rat Insulinoma

The insulin mRNA levels of rat insulinoma cell lines increased six- to eightfold, and the cells entered a transient state of growth arrest when they were cultured in serum-free, hormonally defined medium and on an extract of extracellular matrix derived from a basement membrane-secreting tumor line, EHS. Insulinoma cultures in growth arrest responded to glucose with a two- to threefold increase in insulin secretion associated with an insulin mRNA that contained a poly(A) tail that was 120 to 140 bases longer than normal.

Regulation of insulin mRNA abundance and adenylation: dependence on hormones and matrix substrata

1986 ◽  
Vol 6 (1) ◽  
pp. 337-341
Author(s):  
R Muschel ◽  
G Khoury ◽  
L M Reid
Keyword(s):  
Growth Arrest ◽  
Transient State ◽  
Defined Medium ◽  
Mrna Levels ◽  
Insulinoma Cell ◽  
Threefold Increase ◽  
Hormonally Defined Medium ◽  
Insulin Mrna ◽  
Insulinoma Cell Lines ◽  
Rat Insulinoma

The insulin mRNA levels of rat insulinoma cell lines increased six- to eightfold, and the cells entered a transient state of growth arrest when they were cultured in serum-free, hormonally defined medium and on an extract of extracellular matrix derived from a basement membrane-secreting tumor line, EHS. Insulinoma cultures in growth arrest responded to glucose with a two- to threefold increase in insulin secretion associated with an insulin mRNA that contained a poly(A) tail that was 120 to 140 bases longer than normal.

Novel insulinoma cell lines produced by iterative engineering of GLUT2, glucokinase, and human insulin expression

Diabetes ◽  
1997 ◽  
Vol 46 (6) ◽  
pp. 958-967 ◽  
Author(s):  
S. A. Clark ◽  
C. Quaade ◽  
H. Constandy ◽  
P. Hansen ◽  
P. Halban ◽  
...  
Keyword(s):  
Cell Lines ◽  
Human Insulin ◽  
Insulinoma Cell ◽  
Insulin Expression ◽  
Insulinoma Cell Lines

Age-dependent reduction in insulin secretion and insulin mRNA in isolated islets from rats

1995 ◽  
Vol 269 (6) ◽  
pp. E983-E990 ◽  
Author(s):  
R. Perfetti ◽  
C. M. Rafizadeh ◽  
A. S. Liotta ◽  
J. M. Egan
Keyword(s):  
Beta Cell ◽  
Wistar Rats ◽  
Cell Activity ◽  
Insulin Content ◽  
Dependent Diabetes Mellitus ◽  
Etiologic Factor ◽  
Mrna Levels ◽  
Age Dependent ◽  
Insulin Mrna ◽  
Old Rats

Aging is an etiologic factor in non-insulin-dependent diabetes mellitus. To characterize the beta-cell abnormalities that occur with age, we investigated glucose-stimulated insulin release, pancreatic insulin content, and mRNA levels for islet-specific genes in aging Wistar rats. Ten minutes after glucose stimulation, 6-mo-old islets had approximately 40% more cells secreting insulin than 24-mo-old islets (P < 0.0001); after 1 h, 67 +/- 1.0% islets from 6-mo-old rats secreted insulin, compared with 51 +/- 3.5% from 24-mo-old rats (P < 0.0001). The amount of insulin secreted by each beta-cell was also less in the older animals (P < 0.0001). Despite increases in islet size (P < 0.0001) and beta-cell number (P < 0.0001) with age, whole pancreas insulin content showed that 24-mo-old pancreas had less insulin than 6-mo-old pancreas (0.61 +/- 0.06 vs. 0.84 +/- 0.08 microgram/mg pancreatic protein; P < 0.05). Finally, insulin mRNA levels declined to 50% of the newborn value in 24-mo-old islets (P < 0.0001), whereas glucagon mRNA levels showed a very modest decline with age. Somatostatin mRNA levels did not vary significantly. In summary, it appears that in Wistar rats there is a progressive decline in beta-cell activity with age. This decline may represent the biological features of the age-dependent risk of developing diabetes.

Novel Insulinoma Cell Lines Produced by Iterative Engineering of GLUT2, Glucokinase, and Human Insulin Expression

Diabetes ◽  
1997 ◽  
Vol 46 (6) ◽  
pp. 958-967 ◽  
Author(s):  
S. A. Clark ◽  
C. Quaade ◽  
H. Constantly ◽  
P. Hansen ◽  
P. Halban ◽  
...  
Keyword(s):  
Cell Lines ◽  
Human Insulin ◽  
Insulinoma Cell ◽  
Insulin Expression ◽  
Insulinoma Cell Lines

scholarly journals The expression of transforming growth factor β in pregnant rat myometrium is hormone and stretch dependent

Reproduction ◽  
2007 ◽  
Vol 134 (3) ◽  
pp. 503-511 ◽  
Author(s):  
Oksana Shynlova ◽  
Prudence Tsui ◽  
Anna Dorogin ◽  
B Lowell Langille ◽  
Stephen J Lye
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Late Gestation ◽  
Quiescent State ◽  
Mrna Levels ◽  
Pregnant Rats ◽  
Pregnant Rat ◽  
Threefold Increase ◽  
Antagonist Ru486

From a quiescent state in early pregnancy to a highly contractile state in labor, the myometrium displays tremendous growth and remodeling. We hypothesize that the transforming growth factor β (TGFβ) system is involved in the differentiation of pregnant myometrium throughout gestation and labor. Furthermore, we propose that during pregnancy the mechanical and hormonal stimuli play a role in regulating myometrial TGFβs. The expression of TGFβ1-3 mRNAs and proteins was examined by real-time PCR, Western immunoblot, and localized with immunohistochemistry in the rat uterus throughout pregnancy and labor. Tgfβ1-3 genes were expressed differentially in pregnant myometrium. Tgfβ2 gene was not affected by pregnancy, whereas the Tgfβ1 gene showed a threefold increase during the second half of gestation. In contrast, we observed a dramatic bimodal change in Tgfβ3 gene expression throughout pregnancy. Tgfβ3 mRNA levels first transiently increased at mid-gestation (11-fold on day 14) and later at term (45-fold at labor, day 23). Protein expression levels paralleled the changes in mRNA. Treatment of pregnant rats with the progesterone (P4) receptor antagonist RU486 induced premature labor on day 19 and increased Tgfβ3 mRNA, whereas artificial maintenance of elevated P4 levels at late gestation (days 20–23) caused a significant decrease in the expression of Tgfβ3 gene. In addition, Tgfβ3 was up-regulated specifically in the gravid horn of unilaterally pregnant rats subjected to a passive biological stretch imposed by the growing fetuses, but not in the empty horn. Collectively, these data indicate that the TGFβ family contributes in the regulation of myometrial activation at term integrating mechanical and endocrine signals for successful labor contraction.

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