Modulation of ovarian steroidogenesis by adiponectin during delayed embryonic development of Cynopterus sphinx
Introduction
The slow or retarded embryonic development usually at the blastocyst stage during peri-implantation period leads to delayed embryonic development or embryonic diapause. Delay prior to implantation is the most common form that has been reported in several species of mammals [1]. Cynopterus sphinx exhibit unique reproductive features of post-implantational delayed embryonic development, having described in a few species of bat [2], [3]. The physiological mechanisms which control these interesting processes are varied and incompletely understood.
Cynopterus sphinx breeds twice in a year in quick succession at Varanasi, India (25 °N, 83 °E) [4]. The first pregnancy (winter) is initiated in late October and last for about 150 ± 4 days until March, whereas the second pregnancy (summer) is initiated in April and lasts for about 125 ± 5 days until July. The prolonged gestation length of the first pregnancy of C. sphinx is because of delayed or slow embryonic development during early stage of gastrulation [5]. The cause and control delayed embryonic development during early stage of gastrulation in C. sphinx are under intense investigation in our laboratory.
It is now well demonstrated that the elevated level of progesterone is required for implantation and lowered progesterone level lead to the delayed embryonic development in the bat [6]. Crichton et al. [7] have suggested that the delayed development in Macrotus californicus might be due to delayed luteal cell development and resultant nutritional incompetence of the uterus through inadequate steroid stimulation. The role of corpus luteum in developmental delay has also been examined in C. sphinx [3], in which luteal cells are less active and the number of steroidogenic organelles in luteal cytoplasm is greatly reduced during the period of delayed embryonic development as compared with the period of normal embryogenesis. This study further showed a marked decline in P450 side chain cleavage (SCC) enzyme and steroidogenic acute regulatory protein (StAR) levels in the corpus luteum during the delayed period. The cell proliferation marker, PCNA, cell survival factor, Bcl2 and apoptotic marker, caspase-3 are important for luteal cell development, survival or regression [8]. The corpus luteum is also a site of intense angiogenesis, the formation of dense capillary network is necessary to synthesize and release large quantity of progesterone [9]. The vascular endothelial growth factor (VEGF) has been found to have major role in luteal angiogenesis [9]. It is also not understood whether decreased steroidogenic activity of ovary during embryonic diapauses is due to increased luteal cell regression, decreased vascular supply and/or decreased steroidogenic factors. The cause of low steroidogenic activity in the corpus luteum during this period requires detailed study in order to understand the mechanism of delayed embryonic development in C. sphinx.
The period of suppressed progesterone synthesis and delayed embryonic development in C. sphinx coincided with the period of increased accumulation of white adipose tissue during early winter [10]. The accumulated adipose tissue secretes a number of hormones commonly known as adipokine. Serum level of most common adipokine, leptin are elevated during adiposity and has been shown to regulate many reproductive processes, including menstrual cycle, follicular development, ovulation, pregnancy and puberty [11], [12], [13], [14]. There are a number of studies showing role of leptin in both ovarian activity as well as in early embryonic development [15], [16]. The presence of leptin receptors in the ovary of several mammalian species suggests its role in ovarian activity [12]. Generally high concentration of leptin is shown to have inhibitory effects on ovarian activities including steroidogenic activity of corpus luteum during delayed embryonic development [10]. Earlier study showed luteolytic role for leptin in rabbit corpus luteum [14]. Antczak and van Blerkom [17] showed the presence of leptin receptor (Ob-R) in human and mouse peri-implantation embryos. Mouse blastocyst treated in vitro with human leptin showed increased incidence of apoptosis [18]. While adipokines like leptin have been extensively investigated for their impact on female reproductive organs and early embryonic development in recent years, much less is known about other adipokines, such as adiponectin, resistin [13], [19].
Besides its dominant metabolic role, adiponectin is rather pleiotropic regulator of a large set of biological functions including female reproduction, vascular function, cell growth [20], [21] and is generally known as beneficial adipokines [11]. The adiponectin affects the reproductive system through hypothalamic-pituitary axis, ovary, uterus and embryo [22], [23]. The expression of adiponectin and its receptors were examined in the ovary of various mammalian species including rat, pig, cow, human, bat and chicken [24], [25], [26]. Recent study suggests positive effect of adiponectin on oocyte maturation and early embryo development in porcine, mice and rabbit [27], [28]. The cause and effects of adiponectin have also been assessed in some pregnancy associated disorders [29], [30]. Plasma adiponectin levels are reduced in pre-eclempsia [31] and its signaling generally decreases during reproductive disorders such as polycystic ovary syndrome (PCOS) and endometriosis [30], [32], [33].
The role of adipokines in embryonic diapauses is not extensively investigated. Earlier study from this laboratory has demonstrated the inhibitory role of leptin on progesterone synthesis and on gastrulation during delayed embryonic development of C. sphinx [10]. Therefore, the aim of this study was to investigate the role of other adipokines, adiponectin in regulation of progesterone synthesis of C. sphinx during embryonic diapauses. To achieve, this study elucidated as following: (1) the seasonal variation in serum adiponectin level in a natural population of the female C. sphinx and its correlation with serum progesterone level during the two pregnancies of the year; (2) the expression of adiponectin and its receptor protein in the ovary of C. sphinx during the delay and non-delay period; and (3) the effects of adiponectin treatment in vivo and in vitro on ovarian steroidogenesis, Adiponectin receptor R1 (AdiopR1), and cell survival, proliferation, apoptosis, and angiogenesis during the period of delayed embryonic development in C. sphinx.
Section snippets
Sample collection
All experiments were conducted in accordance with the principles and procedures approved by Banaras Hindu University, Departmental Research Committee. The female bats (C. sphinx) utilized in this study were captured alive from Ramnagar, Varanasi (25°N, 83°E), India. They were then transported to the laboratory immediately. Females weighing 43 g or more and having wing-span exceeding 46 cm were sexually mature [4]. The total number of ninety-six (n = 96) bats were utilized for this study. Bats were
Changes in circulating adiponectin concentration and its correlation with circulating progesterone level during the two pregnancies of the year
The monthly changes in serum adiponectin level were detected by immunoblot followed by densitometric analysis during two successive pregnancies of C. sphinx (Fig. 1) The result showed significant variation in serum adiponectin level and exhibited two peaks, one in September–October and other in April, which corresponds with the two periods of breeding (peri-ovulatory and early embryonic development) in C. sphinx. The adiponectin level declines to lowest levels in December, which corresponds to
Discussion
The aim of this study was to find out the role of adiponectin in modulation of progesterone synthesis during the period of adiposity associated delayed embryonic development in C. sphinx. Three different approaches were undertaken in this study: first, to correlate seasonal changes in circulating adiponectin level with the circulating progesterone level; secondly to evaluate the effects of in vivo treatment of adiponectin on steroidogenesis and associated factors, and thirdly to find out the in
Acknowledgements
This study was financially supported by the Department of Biotechnology (DBT) grant No. BT/PR 10995/BRB/10/627 and Department of Science and Technology (DST), New Delhi, grant No. SR/SO/AS-03/2010. We thank Dr. Puran S. Bora, Department of Ophthalmology, Jones Eye Institute, Pat & Willard Walker Eye Research Center, 4301 West Markham, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA for generously providing the adiponectin antigen. Anuradha is grateful to University
References (73)
- et al.
Luteal cell steroidogenesis in relation to delayed embryonic development in the Indian short-nosed fruit bat, Cynopterus sphinx
Zoology (Jena)
(2009) - et al.
Delayed embryonic development in the Indian short-nosed fruit bat, Cynopterus sphinx
Zoology
(2005) - et al.
Hormones and reproductive cycles in bats
- et al.
Role of leptin in delayed embryonic development in the Indian short nosed fruit bat, Cynopterus sphinx
Gen. Comp. Endocrinol.
(2010) - et al.
Increased circulating leptin level inhibits folliculogenesis in vespertilionid bat, Scotophilus heathi
Mol. Cell. Endocrinol.
(2011) - et al.
Expression of leptin ligand and receptor and effect of exogenous leptin supplement on in vitro development of porcine embryos
Theriogenology
(2006) - et al.
Adipocytokines: leptin—the classical, resistin—the controversial, adiponectin—the promising, and more to come
Best Pract. Res. Clin. Endocrinol. Metab.
(2005) - et al.
Changes in the gene expression of adiponectin and adiponectin receptors (AdipoR1 and AdipoR2) in ovarian follicular cells of dairy cow at different stages of development
Theriogenology
(2010) - et al.
Adiponectin increases insulin-like growth factor I-induced progesterone and Estradiol secretion in human granulosa cells
Fertil. Steril.
(2009) - et al.
Localization of adiponectin and its receptor and its possible roles in the ovary of a vespertilionid bat, Scotophilus heathi
Gen. Comp. Endocrinol.
(2012)
Adiponectin enhances in vitro development of swine embryos
Domest. Anim. Endocrinol.
Reduced plasma adiponectin and elevated leptin in pre-eclampsia
Int. J. Gynaecol. Obstet.
Effects of adiponectin on ovarian folliculogenesis and steroidogenesis in the vespertilionid bat, Scotophilus heathi
Gen. Comp. Endocrinol.
Adiponectin and the control of female reproductive functions
Vitam. Horm.
Disruption of adiponectin causes insulin resistance and neointimal formation
J. Biol. Chem.
Changes in the gene expression of adiponectin and adiponectin receptors (AdipoR1 and AdipoR2) in ovarian follicular cells of dairy cow at different stages of development
Theriogenology
Cloning, expression and chromosome localization of porcine adiponectin and adiponectin receptors genes
Domest. Anim. Endocrinol.
Role of adiponectin in regulating ovarian theca and granulosa cell function
Mol. Cell. Endocrinol.
Molecular cloning and tissue expression of chicken AdipoR1 and AdipoR2 complementary deoxyribonucleic acids
Domest. Anim. Endocrinol.
Expression of adiponectin and its receptors (AdipoR1 and AdipoR2) in chicken ovary: potential role in ovarian steroidogenesis
Domest. Anim. Endocrinol.
Hormonal and gestational evidence for delayed implantation in the striped skunk, Mephitis mephitis
Gen. Comp. Endocrinol.
Adiponectin stimulates angiogenesis by promoting cross-talk between AMP-activated protein kinase and Akt signaling in endothelial cells
J. Biol. Chem.
Embryonic diapause in vertebrates
J. Exp. Zool.
Reproductive timing and early embryonic development in an old world fruit bat, Otopterus cartilagonodus (Megachiroptera)
J. Mammal.
Reproduction in the female short-nosed fruit bat Cynopterus sphinx (Vahl)
Period. Biol.
Cellular composition and steroidogenic capacity of the ovary of Macrotus californicus (Chiroptera: Phyllostomatidae) during and after delayed embryonic development
Cell Tissue Res.
The Bcl-2 protein family: arbiters of cell survival
Science
Angiogenesis in the corpus luteum
Reprod. Biol. Endocrinol.
The ‘beneficial’ adipokines in reproduction and fertility
Int. J. Obes.
Adipokines: implications for female fertility and obesity
Reproduction
Ob receptor in rabbit ovary and leptin in vitro regulation of corpora lutea
J. Endocrinol.
Maturation of bovine oocytes in the presence of leptin improves development and reduces apoptosis of in vitro-produced blastocysts
Biol. Reprod.
Oocyte influences on embryo development: the regulatory proteins leptin and STAT3 are polarized in mouse and human oocytes and differentially distributed within the cells of the pre-implantation stage embryo
Mol. Hum. Reprod.
Effects of leptin and leukemia inhibitory factor on preimplantation development and STAT3 signaling of mouse embryos in vitro
Biol. Reprod.
Expression of adiponectin receptors and effects of adiponectin isoforms in mouse preimplantation embryos
Hum. Reprod.
Adiponectin and cancer: a systematic review
Br. J. Cancer
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