Dataset Information

Elevated levels of insulin-like growth factor (IGF)-I in serum rescue the severe growth retardation of IGF-I null mice.

ABSTRACT: IGF-I plays a vital role in growth and development and acts in an endocrine and an autocrine/paracrine fashion. The purpose of the current study was to clarify whether elevated levels of IGF-I in serum can rescue the severe growth retardation and organ development and function of igf-I null mice. To address that, we overexpressed a rat igf-I transgene specifically in the liver of igf-I null mice. We found that in the total absence of tissue IGF-I, elevated levels of IGF-I in serum can support normal body size at puberty and after puberty but are insufficient to fully support the female reproductive system (evident by irregular estrous cycle, impaired development of ovarian corpus luteum, reduced number of uterine glands and endometrial hypoplasia, all leading to decreased number of pregnancies and litter size). We conclude that most autocrine/paracrine actions of IGF-I that determine organ growth and function can be compensated by elevated levels of endocrine IGF-I. However, in mice, full compensatory responses are evident later in development, suggesting that autocrine/paracrine IGF-I is critical for neonatal development. Furthermore, we show that tissue IGF-I is necessary for the development of the female reproductive system and cannot be compensated by elevated levels of serum IGF-I.

SUBMITTER: Wu Y

PROVIDER: S-EPMC2819739 | biostudies-literature | 2009 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Elevated levels of insulin-like growth factor (IGF)-I in serum rescue the severe growth retardation of IGF-I null mice.

Wu Yingjie Y Sun Hui H Yakar Shoshana S LeRoith Derek D

Endocrinology 20090604 9

IGF-I plays a vital role in growth and development and acts in an endocrine and an autocrine/paracrine fashion. The purpose of the current study was to clarify whether elevated levels of IGF-I in serum can rescue the severe growth retardation and organ development and function of igf-I null mice. To address that, we overexpressed a rat igf-I transgene specifically in the liver of igf-I null mice. We found that in the total absence of tissue IGF-I, elevated levels of IGF-I in serum can support no ...[more]

PMID: 19497975

Similar Datasets

Project description:BACKGROUND:Some, but not all, epidemiologic evidence supports a role for cholesterol, the precursor for steroid hormone synthesis, in prostate cancer. Using a PTEN-null transgenic mouse model of prostate cancer, we tested the effect of modifying serum cholesterol levels on prostate tumor development and growth. We hypothesized that serum cholesterol reduction would lower tumor androgens and slow prostate cancer growth. METHODS:PTENloxP/loxP-Cre+ mice consuming ad libitum high fat, high cholesterol diets (40% fat, 1.25% cholesterol) were randomized after weaning to receive the cholesterol uptake inhibitor, ezetimibe (30?mg/kg/day), or no intervention, and sacrificed at 2, 3, or 4 months of age. Serum cholesterol and testosterone were measured by ELISA and intraprostatic androgens by mass spectrometry. Prostate histology was graded, and proliferation and apoptosis in tumor epithelium and stroma was assessed by Ki67 and TUNEL, respectively. RESULTS:Ezetimibe-treated mice had lower serum cholesterol at 4 months (p?=?0.031). Serum cholesterol was positively correlated with prostate weight (p?=?0.033) and tumor epithelial proliferation (p?=?0.069), and negatively correlated with tumor epithelial apoptosis (p?=?0.004). Serum cholesterol was unrelated to body weight (p?=?0.195). Tumor stromal cell proliferation was reduced in the ezetimibe group (p?=?0.010). Increased serum cholesterol at 4 months was associated with elevated intraprostatic DHEA, testosterone, and androstenedione (p?=?0.043, p?=?0.074, p?=?0.031, respectively). However, cholesterol reduction did not significantly affect adenocarcinoma development at 2, 3, or 4 months of age (0, 78, and 100% in ezetimibe-treated vs. 0, 80, and 100% in mice not receiving ezetimibe). CONCLUSIONS:Though serum cholesterol reduction did not significantly affect the rate of adenocarcinoma development in the PTEN-null transgenic mouse model of prostate cancer, it lowered intraprostatic androgens and slowed tumor growth. These findings support a role for serum cholesterol in promoting prostate cancer growth, potentially via enhanced tumor androgen signaling, and may provide new insight into cholesterol-lowering interventions for prostate cancer treatment.

Dataset Information

Elevated levels of insulin-like growth factor (IGF)-I in serum rescue the severe growth retardation of IGF-I null mice.

Publications

Elevated levels of insulin-like growth factor (IGF)-I in serum rescue the severe growth retardation of IGF-I null mice.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets