scholarly journals Regulation of nerve growth factor synthesis and release in organ cultures of rat iris.

1984 ◽  
Vol 99 (3) ◽  
pp. 839-843 ◽  
Author(s):  
E M Barth ◽  
S Korsching ◽  
H Thoenen

We studied the synthesis and release of nerve growth factor (NGF) in cultured rat iris with a two-site enzyme immunoassay by measuring the time course of NGF levels remaining in the iris and relased into the medium up to 72 h. For up to 3 h, the NGF levels in the iris did not change significantly. After that, they increased to a maximal level of 350 +/- 30 pg NGF/iris at 19 h, which is 200 times higher than the in vivo content. Between 20 and 72 h in culture, the NGF level decreased to 130 +/- 10 pg NGF/iris, whereas general protein synthesis did not change during that time period. Maximal rate of NGF production (203 pg NGF/h/iris) was seen between 9 and 12 h in culture. In the medium, NGF levels were first detectable after 6 h. Levels then increased with a time course similar to that seen within the iris, reaching a maximal level of 1,180 +/- 180 pg after 19 h in vitro, and then did not significantly change for up to 48 h. The NGF production of the densely sympathetically innervated dilator was three times higher than that of the predominantly cholinergically innervated sphincter. The NGF production was blocked by inhibitors of messenger RNA synthesis (actinomycin D) and of polyadenylation (9-beta-D-arabinofuranosyladenine) as well as by inhibitors of translation (cycloheximide). Monensin, which interferes with the transport of proteins through the Golgi apparatus, decreased NGF levels to 8-12% of controls in the medium, suggesting that the Golgi apparatus is involved in the intracellular processing of NGF.

2014 ◽  
Vol 22 ◽  
pp. S35
Author(s):  
C. Driscoll ◽  
A. Chanalaris ◽  
C. Knight ◽  
C. Gentry ◽  
S. Bevan ◽  
...  

Development ◽  
1970 ◽  
Vol 24 (2) ◽  
pp. 381-392
Author(s):  
Peddrick Weis

The effect of the nerve growth factor (NGF) on chick embryo spinal ganglia was studied in the hanging-drop bioassay system by comparison with parallel development in vivo. The well-differentiated ventrolateral neuroblasts, which in vivo increase 1·33 times in size during the culture period, did not increase in size at all in vitro. Only 65–72% survived to the end of the culture period regardless of the NGF concentration. The less-differentiated mediodorsal (M-D) neuroblasts, which in vivo increase 1·31 times in size during the culture period, were found to increase equally in vitro if sufficient NGF was present. Such a quantity was greater than that which evoked maximum outgrowth of neurites. Survival of M-D neuroblasts was also related to NGF concentration but did not equal the in vivo condition even at the highest concentration. The hyperchromatic type of degeneration prevented by high NGF concentrations is that which results in vivo from insufficient peripheral field. From this and other reports it would appear that the response to NGF seen in vitro is due only to the M-D neuroblasts, and that all biochemical and cytological observations which have been reported would therefore represent conditions within those cells only.


2020 ◽  
Vol 295 (52) ◽  
pp. 18051-18064
Author(s):  
Cherry Wongtrakool ◽  
Junsuk Ko ◽  
Andrew J. Jang ◽  
Kora Grooms ◽  
Sarah Chang ◽  
...  

Evolving evidence suggests that nicotine may contribute to impaired asthma control by stimulating expression of nerve growth factor (NGF), a neurotrophin associated with airway remodeling and airway hyperresponsiveness. We explored the hypothesis that nicotine increases NGF by reducing lung fibroblast (LF) microRNA-98 (miR-98) and PPARγ levels, thus promoting airway remodeling. Levels of NGF, miR-98, PPARγ, fibronectin 1 (FN1), endothelin-1 (EDN1, herein referred to as ET-1), and collagen (COL1A1 and COL3A1) were measured in human LFs isolated from smoking donors, in mouse primary LFs exposed to nicotine (50 μg/ml), and in whole lung homogenates from mice chronically exposed to nicotine (100 μg/ml) in the drinking water. In selected studies, these pathways were manipulated in LFs with miR-98 inhibitor (anti-miR-98), miR-98 overexpression (miR-98 mimic), or the PPARγ agonist rosiglitazone. Compared with unexposed controls, nicotine increased NGF, FN1, ET-1, COL1A1, and COL3A1 expression in human and mouse LFs and mouse lung homogenates. In contrast, nicotine reduced miR-98 levels in LFs in vitro and in lung homogenates in vivo. Treatment with anti-miR-98 alone was sufficient to recapitulate increases in NGF, FN1, and ET-1, whereas treatment with a miR-98 mimic significantly suppressed luciferase expression in cells transfected with a luciferase reporter linked to the putative seed sequence in the NGF 3′UTR and also abrogated nicotine-induced increases in NGF, FN1, and ET-1 in LFs. Similarly, rosiglitazone increased miR-98 and reversed nicotine-induced increases in NGF, FN1, and ET-1. Taken together, these findings demonstrate that nicotine-induced increases in NGF and other markers of airway remodeling are negatively regulated by miR-98.


2005 ◽  
Vol 102 (51) ◽  
pp. 18658-18663 ◽  
Author(s):  
A. M. Colangelo ◽  
N. Finotti ◽  
M. Ceriani ◽  
L. Alberghina ◽  
E. Martegani ◽  
...  

1985 ◽  
Vol 101 (5) ◽  
pp. 1799-1807 ◽  
Author(s):  
D G Drubin ◽  
S C Feinstein ◽  
E M Shooter ◽  
M W Kirschner

Nerve growth factor (NGF) regulates the microtubule-dependent extension and maintenance of axons by some peripheral neurons. We show here that one effect of NGF is to promote microtubule assembly during neurite outgrowth in PC12 cells. Though NGF causes an increase in total tubulin levels, the formation of neurites and the assembly of microtubules follow a time course completely distinct from that of the tubulin induction. The increases in microtubule mass and neurite extension closely parallel 10- and 20-fold inductions of tau and MAP1, proteins shown previously to promote microtubule assembly in vitro. When NGF is removed from PC12 cells, neurites disappear, microtubule mass decreases, and both microtubule-associated proteins return to undifferentiated levels. These data suggest that the induction of tau and MAP1 in response to NGF promotes microtubule assembly and that these factors are therefore key regulators of neurite outgrowth.


Sign in / Sign up

Export Citation Format

Share Document