scholarly journals Insulin-Like Growth Factor Bioactivity, Stanniocalcin-2, Pregnancy-Associated Plasma Protein-A, and IGF-Binding Protein-4 in Pleural Fluid and Serum From Patients With Pulmonary Disease

2017 ◽  
Vol 102 (9) ◽  
pp. 3526-3534 ◽  
Author(s):  
Ulrick Skipper Espelund ◽  
Mette Bjerre ◽  
Rikke Hjortebjerg ◽  
Torben Riis Rasmussen ◽  
Anders Lundby ◽  
...  

Abstract Context Members of the insulin-like growth factor (IGF) system are primarily produced in the liver and secreted into the circulation, but they are also produced, recruited, and activated locally in tissues. Objective To compare activity and concentrations of IGF system components in pleural fluid and blood. Design Pathological pleural fluid, secondary to lung cancer or nonmalignant disease, and matching blood samples were collected from 24 patients ages 66.7 to 81.9 years. Methods IGF-related proteins and cytokine levels were measured by immunoassays or immunoblotting. Bioactive IGF was measured by an IGF-1 receptor phosphorylation assay. Results Total IGF-1 concentration did not differ between the compartments, but concentrations of free IGF-1 and bioactive IGF were more than threefold higher in pleural fluid than in corresponding serum samples (P = 0.0004), regardless of etiology. Median pregnancy-associated plasma protein-A (PAPP-A) and interleukin (IL)-6 levels were increased 47-fold and 143-fold, respectively, in pleural fluid compared with plasma (P < 0.0001). PAPP-A and IL-6 concentrations correlated positively (r = 0.46; P = 0.02). In pleural fluid, levels of PAPP-A–generated IGF binding protein-4 fragments correlated inversely with that of stanniocalcin-2 (r ≤ −0.42; P ≤ 0.05), a PAPP-A inhibitor; such correlations were absent in plasma. Conclusion Pathological pleural fluid is characterized by increased in vitro IGF bioactivity and elevated concentrations of PAPP-A, an IGF-activating proteinase. Thus, the tissue activity of the IGF system may differ substantially from that of the circulating IGF system. The correlation between IL-6 and PAPP-A indicates that inflammation plays a role in promoting local tissue IGF activity.

2018 ◽  
Vol 39 ◽  
pp. 54-61 ◽  
Author(s):  
Rikke Hjortebjerg ◽  
Darlene E. Berryman ◽  
Ross Comisford ◽  
Edward O. List ◽  
Claus Oxvig ◽  
...  

1997 ◽  
Vol 272 (5) ◽  
pp. F661-F667 ◽  
Author(s):  
R. M. Rohan ◽  
T. G. Unterman ◽  
L. Liu ◽  
M. K. Hise

We studied the renal expression of the insulin-like growth factor (IGF) system to gain a better perspective of its potential role in the hyperplastic adaptation of the distal nephron to potassium deficiency. Rats were pair fed 1% or 0.002% potassium diets for periods up to 10 days. IGF-I mRNA was diminished in potassium-deficient rats within 4 days, whereas mRNA for IGF binding protein-1 (IGFBP-1), a collecting duct-associated protein, was increased by day 7. At day 10 mRNA for IGFBP-1 in potassium-deficient animals averaged 2.07 +/- 0.53 (mean +/- SD, relative densitometry units) compared with 0.89 +/- 0.26 in control rats (n = 4, P = 0.002). Conversely, IGFBP-3, a binding protein whose mRNA has been localized to the interstitial compartment, averaged 2.40 +/- 0.02 in potassium-deficient rats and 4.77 +/- 0.05 in controls (n = 4, P < 0.03) at day 10 of treatment. Immunohistochemistry performed using a specific IGFBP-1 antibody revealed hyperplasia of distal nephron segments along with an increase in IGFBP-1 in potassium-depleted rats. These data suggest that IGFBP-1 may play an important role in the control of cellular adaptations in the hypokalemic rat kidney either directly by influencing cell migration or indirectly by localizing IGF-I to the distal nephron.


2003 ◽  
pp. 31-37 ◽  
Author(s):  
JM Weiss ◽  
B Krautmacher ◽  
S Polack ◽  
K Diedrich ◽  
O Ortmann

OBJECTIVE: Recently, GnRH antagonists (GnRHants) have been introduced for the prevention of premature LH surges during controlled ovarian hyperstimulation (COH). Here we investigated whether the GnRHants cetrorelix and ganirelix exert effects on the human ovarian IGF system. Since controversy exists on the action of GnRH agonists in the human ovary, we also tested the effect of triptorelin on IGF-II, IGF-binding protein-2 (IGFBP-2) and pregnancy-associated plasma protein-A (PAPP-A) in cultured human granulosa-lutein cells. DESIGN: In vitro cell culture study in a research laboratory of a university hospital. PATIENTS: Cells were obtained from patients treated with different protocols of COH. In addition to gonadotropins they received triptorelin or cetrorelix. Cells were treated with triptorelin, cetrorelix or ganirelix, 1 nmol/l each, for 48 h. IGF-II, IGFBP-2 and PAPP-A were measured by RIA and enzyme immunoassay respectively. RESULTS: GnRHants and triptorelin did not affect IGF-II, IGFBP-2 or PAPP-A. CONCLUSIONS: We conclude that GnRHants do not exert any significant effects on the IGF system of granulosa-lutein cells and therefore their introduction into protocols of COH is unlikely to impair ovarian function.


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