0
We're unable to sign you in at this time. Please try again in a few minutes.
Retry
We were able to sign you in, but your subscription(s) could not be found. Please try again in a few minutes.
Retry
There may be a problem with your account. Please contact the AMA Service Center to resolve this issue.
Contact the AMA Service Center:
Telephone: 1 (800) 262-2350 or 1 (312) 670-7827  *   Email: subscriptions@jamanetwork.com
Error Message ......
Original Investigation |

The Effects of Insulin-like Growth Factor 1 and Growth Hormone on Human Meibomian Gland Epithelial Cells

Juan Ding, PhD1,2; David A. Sullivan, PhD1,2
[+] Author Affiliations
1Schepens Eye Research Institute, Massachusetts Eye and Ear, Boston
2Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
JAMA Ophthalmol. 2014;132(5):593-599. doi:10.1001/jamaophthalmol.2013.8295.
Text Size: A A A
Published online

Importance  A phase 1 study has reported that dry eye disease is the most common adverse effect of human exposure to the antibody figitumumab, an anticancer drug that prevents insulin-like growth factor 1 (IGF-1) from binding to its receptor. We hypothesized that the mechanism underlying this effect is the inhibition of IGF-1 action in epithelial cells of the meibomian gland.

Objectives  To test the hypothesis that IGF-1 stimulates meibomian gland function in vitro and to examine whether growth hormone, a closely related hormone of IGF-1, has the same effect.

Design, Setting, and Material  Immortalized human meibomian gland epithelial cells were cultured in the presence or the absence of IGF-1, growth hormone, and an IGF-1 receptor–blocking antibody. Signaling pathways, cell proliferation, neutral lipid staining, and a key protein involved in lipid biogenesis were evaluated.

Intervention  Application of IGF-1 and growth hormone to human meibomian gland epithelial cells.

Main Outcomes and Measures  Immunoblotting, cell counting, and neutral lipid staining.

Results  Insulin-like growth factor 1 activated the phosphoinositol 3-kinase/Akt and forkhead box O1 pathways (showing a dose-dependent effect on immunoblotting), stimulated cellular proliferation (about 1.8-fold increase in cell number), increased sterol regulatory element-binding protein 1 expression (about 3-fold increase on immunoblotting), and promoted lipid accumulation in human meibomian gland epithelial cells (about 2-fold increase in lipid staining). These IGF-1 actions, which may be blocked by cotreatment with the anti–IGF-1 antibody, were accompanied by inconsistent effects on extracellular signal-regulated kinase phosphorylation. We were not able to demonstrate activation of Akt, forkhead box O1, extracellular signal-regulated kinase, Janus kinase 2, or signal transducers and activators of transcription 5, induced cell proliferation, or lipid accumulation in these cells by growth hormone application.

Conclusions and Relevance  Our results support the hypothesis that IGF-1 acts on human meibomian gland epithelial cells and may explain why treatment with figitumumab, the IGF-1 inhibitor, causes dry eye disease. Ophthalmic care for dry eye disease may be needed when patients with cancer undergo treatment with drugs that inhibit IGF-1 action.

Figures in this Article

Sign in

Create a free personal account to sign up for alerts, share articles, and more.

Purchase Options

• Buy this article
• Subscribe to the journal

Figures

Place holder to copy figure label and caption
Figure 1.
Effects of Insulin-like Growth Factor 1 (IGF-1) and Growth Hormone (GH) on Signaling Pathways in Human Meibomian Gland Epithelial Cells

Cells were cultured in keratinocyte serum-free medium containing epidermal growth factor (EGF) and bovine pituitary extract (BPE) for 2 days and then keratinocyte serum-free medium alone overnight or were cultured in 10% fetal bovine serum (FBS) medium for 5 to 7 days and in 1% FBS medium overnight. Cells were then incubated with vehicle or a 10µM concentration of LY294002 for 2 hours, followed by IGF-1 or GH treatment for 15 minutes. Cell lysates were evaluated on immunoblotting. A, Dose-dependent effect of IGF-1 on Akt phosphorylation. B, IGF-1 and GH influence on the phosphorylated and total levels of Akt, forkhead box O1 (FoxO1), and extracellular signal-regulated kinase (ERK). Minus signs indicate without; plus signs, with. C, Effect of GH on the Janus kinase 2/signal transducers and activators of transcription 5 (JAK2/STAT5) pathways in meibomian gland epithelial cells and the LNCaP cancer cell line. These experiments were repeated at least 3 times with similar results.

Graphic Jump Location
Place holder to copy figure label and caption
Figure 2.
Influence of Insulin-like Growth Factor 1 (IGF-1) on the Proliferation of Human Meibomian Gland Epithelial Cells

Cells were cultured (100 000 cells/well in 12-well plates, 3 wells per group) in basal, proliferating, and/or differentiating media and treated with IGF-I for 2 to 6 days. A, Meibomian gland epithelial cell proliferation. B, Meibomian gland cell proliferation in serum-containing media for 6 days. P values are for post hoc comparison compared with the control value. C, LNCaP cells (20 000 cells/well in 12-well plates, 3 wells per group) were initially cultured in Dulbecco modified Eagle medium/Ham F-12 nutrient media mixture containing 10% fetal bovine serum (FBS), then switched to 1% FBS and exposed to IGF-1 or growth hormone (GH) for 2 days. ANOVA indicates analysis of variance; EGF-BPE, epidermal growth factor–bovine pituitary extract; KSFM, keratinocyte serum-free medium. All comparisons are with control value. Whiskers mark SEM.aP < .05 compared with the control value, post hoc test.

Graphic Jump Location
Place holder to copy figure label and caption
Figure 3.
Effect of Insulin-like Growth Factor 1 (IGF-1) on Sterol Regulatory Element-Binding Protein 1 (SREBP-1) Expression and Lipid Accumulation in Human Meibomian Gland Epithelial Cells

Cells were exposed to IGF-1 or growth hormone (GH) for 6 days in differentiation media and then processed for the analysis of the precursor form of SREBP-1 protein. A, Results of immunoblotting. B, Results of green neutral lipid staining. The red color represents 4′,6-diamidino-2-phenylindole nuclear staining. The SREBP-1 densitometry, normalized to that of β-actin, and neutral lipid staining fluorescence intensity (6 field views per treatment condition) were quantified by using image-processing software (ImageJ; http://rsb.info.nih.gov/ij). These experiments were repeated at least 3 times with similar results. ANOVA indicates analysis of variance; AU, arbitrary units. Whiskers represent SEM.aP < .01 compared with the control value, post hoc test.bP < .05 compared with the control value, post hoc test.cP < .001 compared with the control value, post hoc test.

Graphic Jump Location
Place holder to copy figure label and caption
Figure 4.
Inhibition of Insulin-like Growth Factor 1 (IGF-1) Action by an IGF-1 Receptor (IGF-1R)–Blocking Antibody in Human Meibomian Gland Epithelial Cells

A, Cells were cultured in medium containing 10% fetal bovine serum (FBS) for 5 days and then switched to 1% FBS medium containing various doses of anti–IGF-1R overnight, followed by IGF-1 treatment for 15 minutes. Antibody treatment inhibited the IGF-1–induced Akt phosphorylation in a dose-dependent manner. B, Cells were exposed to a 10nM concentration of IGF-1 and/or a 10nM concentration of anti–IGF-1R for 6 days in serum-containing media and then processed for green neutral lipid staining. The red color represents 4′,6-diamidino-2-phenylindole nuclear staining. The antibody reduced the IGF-1–stimulated accumulation of lipids. These experiments were repeated twice with similar results. mAb indicates monoclonal antibody.

Graphic Jump Location

Tables

References

Correspondence

CME
Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.
Submit a Comment

Multimedia

Some tools below are only available to our subscribers or users with an online account.

Sign in

Create a free personal account to sign up for alerts, share articles, and more.

Purchase Options

• Buy this article
• Subscribe to the journal

Related Content

Customize your page view by dragging & repositioning the boxes below.

Articles Related By Topic
Related Collections
PubMed Articles
Jobs
JAMAevidence.com

Users' Guides to the Medical Literature
Table 9.2-3 Refuted Evidence From Observational Studiesa

brightcove.createExperiences();