Correlation Between PTEN and VEGF Expressions During the Development of Gas Gland in Japanese Eel (Anguilla japonica) Stimulated by Exogenous Hypophyseal Factors

Abstract

Organogenesis requires support of the vascular system and control of proliferation activity. VEGF, a selective mitogen for vascular endothelial cells, is important for vessel development. PTEN, known as a tumor suppressor, regulates cell size and modulates VEGF-mediated signaling on angiogenesis. However, it is not yet clear if PTEN controls tissue mass by suppressing angiogenesis provoked by VEGF and their correlations in postnatal tissue development in vivo. We used a primitive vertebrate, Japanese eel (Anguilla japonica), to study this question. Swim bladder gas glands (a somatic tissue composed mainly by the capillaries) from normal eels or eels injected with hypophyseal factors were used to examine the expression of VEGF A, PTEN, IGF-1, and Flk-1 by RT-PCR. Two forms of PTEN (PTEN a, long form, and PTEN b, short form) cDNA have been cloned. There was no correlation between VEGF expression and gas gland tissue mass while a negative correlation between PTEN expression and tissue mass was noted; further, a higher correlation between the tissue mass and the ratio of VEGF to PTEN was shown. In summary, we have shown the involvement of VEGF and PTEN in postnatal tissue development, the ratio of VEGF to PTEN may represent the growth status of the tissue.

Testosterone improves the transition of primary oocytes in artificial maturation eels (Anguilla japonica) by altering ovarian PTEN expression

“…Two forms of PTEN existing in the Japanese eel Two forms of PTEN have been cloned from the Japanese eel; PTEN-long form has an additional 69 nucleotides coded 23 amino acids in the C-terminal as compared with the PTEN-short one (Chen et al 2008), an antiserum against these peptides composed of these additional 23 amino acids is raised; a stronger immunoreactivity around the perinuclear zones was 0 week PTEN long, GSI = 0.65 % CPE 9 weeks PTEN long, GSI = 2.05 %.…”

“…On the ovarian development, it has been postulated that inhibitors of PTEN may be potential drugs for stimulation of both activation and survival of immature follicle in mammals (Adhikari and Liu 2009), but there are no data concerning this question in the fish. Two forms of PTEN (PTEN-long form and PTENshort form) cDNA have been cloned from the Japanese eel, and a close correlation between PTEN-short form and VEGF (vascular endothelial cells growth factor) expression in the stimulated gas gland (rete mirabilia) has also showed (Chen et al 2008), but what different roles between these two forms of PTEN on the development of ovarian follicles are not clear in the eel.…”