In vitro and in vivo improvement of islet survival following treatment with nerve growth factor.
BACKGROUND
Nerve growth factor (NGF) has been reported to play an important regulatory role in pancreatic beta-cell function. However, the usefulness of NGF in a transplantation setting is unknown.


METHODS
A marginal number of islet cells (260 islet equivalents/recipient) cultured for 24 hr with NGF (500 ng/ml) was syngeneically transplanted under the kidney capsule of streptozotocin-induced diabetic Balb/c mice. Fluorescence microscopy was used to evaluate islet viability. Islet function was evaluated in vitro and in vivo by static assay and glucose tolerance test, respectively.


RESULTS
In vitro, improved viability and survival were found in murine islets cultured in serum-free medium for 96 hr with 500 ng/ml NGF (P<0.05). NGF-treated islets had more insulin secretion than islets cultured without NGF in response to 2.8 mmol/L glucose (P<0.05), and 20 mmol/L glucose conditions. In vivo, 67% of recipients with a submarginal number of islets cultured in NGF attained normoglycemia for more than 120 days, whereas transplanted islets without NGF treatment survived a maximum of 13 days in control mice. At posttransplant day 4, recipients of NGF-cultured islets showed significant improvement of glucose tolerance. On immunohistochemistry, the kidney capsules containing NGF-cultured islets displayed higher insulin content, and more dilated neoplastic microvessels than control renal capsules. The number of apoptotic cells using TUNEL staining decreased by nearly 50% in NGF-cultured islet grafts in comparison to control islet grafts.


CONCLUSIONS
The above data suggest potential advantages of NGF for islet survival following transplantation. This neurotrophic approach may prove beneficial in human islet transplantation.
Islet Transplant Laboratory, Department of Pediatrics, Loma Linda University, Loma Linda, CA 92354, USA.
Gang
G
Miao
John
J
Mace
Michael
M
Kirby
Andrew
A
Hopper
Ricardo
R
Peverini
Richard
R
Chinnock
James
J
Shapiro
Eba
E
Hathout
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D007150:Immunohistochemistry; D007515:Islets of Langerhans / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D016381:Islets of Langerhans Transplantation / Q000502:physiology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D020932:Nerve Growth Factor / Q000494:pharmacology*
D020932:Nerve Growth Factor