New approach to in situ quantification of ovarian gene expression in rat using a laser microdissection technique: relationship between follicle types and regulation of inhibin-alpha and cytochrome P450aromatase genes in the rat ovary

Ontogeny of adropin and its receptor expression during postnatal development and its pro-gonadal role in the ovary of pre-pubertal mouse

Adropin, a highly conserved multifunctional peptide hormone, has a beneficial effect on the maintenance of gluco-lipid homeostasis, endothelial and cardiovascular functions. However, the expression and potential role of adropin in ovarian function are not fully elucidated. The present study aimed to investigate the expression of adropin and GPR19 in the mice ovary during various stages of postnatal development. This study also explored whether the treatment of adropin can modulate the timing of puberty, for which pre-pubertal mice were treated with adropin. The result showed the intense immunoreactivity of adropin in TICs, while GPR19 immunoreactivity was noted in GCs in infantile, pre-pubertal, and pubertal mice ovary. Also, adropin and GPR19 are highly expressed in the CL of the ovary of reproductively active mice. The fact that adropin expression in the ovary at different stages of postnatal development positively correlated with circulating progesterone and estradiol indicated that it has a role in the production of steroid hormones. Furthermore, the results of in vivo studies in pre-pubertal mice showed that adropin promotes early folliculogenesis by enhancing the proliferation (PCNA) of GCs of cortical ovarian follicles and promotes estradiol production by enhancing the expression of GPR19, StAR, CYP11A1 and aromatase proteins. Also, adropin treatment increases the Bax/Bcl2 ratio and expression of cleaved caspase-3 and ERα proteins, which may result in increased apoptosis of medullary follicles leading to the formation of a well-developed interstitium with interstitial glandular cells. Collectively, these findings indicate that adropin may be a factor that accelerates pubertal development in the ovary and could be utilized as a therapeutic approach for treating pubertal delay.

Kisspeptin promotes follicular development through its effects on modulation of P450 aromatase expression and steroidogenesis in sheep ovarian follicles

The present study was conducted to ascertain whether the role of kisspeptin in promoting in vitro development of preantral follicles was through the regulation of P450 aromatase gene expression and steroidogenesis in sheep. Accordingly, the cumulus cells and oocytes were collected from different development stages of preantral follicles grown in vivo and cultured in vitro in TCM199B (Group I), TCM199B + KP (10 μg/mL) (Group II) and Standard medium + KP (10 μg/mL). To measure the steroid (Estradiol-17β; E2 and Progesterone; P4 ) synthesis through ELISA, spent culture medium was collected separately from the same in vitro groups. E2 synthesis in the spent medium collected from all the three groups showed an increasing trend from PFs' exposed to respective culture media for 3 min to 2-day culture stage but decreased thereafter till 6-day culture stage. This is followed by a sharp increase in E2 concentration in the spent medium collected after in vitro maturation. However, P4 synthesis in group III followed increased pattern as the development progressed from PFs' exposed to culture medium for 3 min to in vitro maturation stage. The steroid production was observed at all stages of in vitro development in altered supplemented conditions. The steroid synthesis in the spent medium was highest in the 6 day cultured PFs' in Standard medium + KP matured in vitro for 24 h. Therefore, supplementation of kisspeptin along with other growth factors promoted steroid production in cultured preantral follicles far better than in other media.

Histochemistry and Cell Biology-a glance into the past and a look ahead

At the occasion of the 65th anniversary of Histochemistry and Cell Biology, we browse through its first ten years of publication and highlight a selection of papers from the early days of enzyme, protein, and carbohydrate histochemistry. In addition, we narrate recent progress to identify, quantify, and precisely determine the tissue localization of proteins and lipids, and small molecules by the combination of spectroscopic techniques and histology.

LncPrep + 96kb 2.2 kb Inhibits Estradiol Secretion From Granulosa Cells by Inducing EDF1 Translocation

LncPrep + 96kb is a novel long non-coding RNA expressed in murine granulosa cells with two transcripts that are 2.2 and 2.8 kb in length. However, the potential roles of lncPrep + 96kb in granulosa cells remain poorly understood. In this study, we investigated the effect of the lncPrep + 96kb 2.2 kb transcript on granulosa cells through the overexpression and knockdown of lncPrep + 96kb 2.2 kb. We found that lncPrep + 96kb 2.2 kb inhibited aromatase expression and estradiol production. Endothelial differentiation-related factor 1 (EDF1) is an evolutionarily conserved transcriptional coactivator. We found that EDF1 knockdown inhibited aromatase expression and estradiol production. The RNA immunoprecipitation results also showed that lncPrep + 96kb 2.2 kb can bind to EDF1 and that overexpression of lncPrep + 96kb 2.2 kb induced the translocation of EDF1 from the nucleus to the cytoplasm. The CatRAPID signature revealed that the 1,979–2,077 and 603–690 nucleotide positions in lncPrep + 96kb 2.2 kb were potential binding sites for EDF1. We found that mutating the 1,979–2,077 site rescued the effects of lncPrep + 96kb 2.2 kb on aromatase expression and estradiol production. In conclusion, we are the first to report that specific expression of lncPrep + 96kb 2.2 kb in granulosa cells inhibits the production of estradiol by influencing the localization of EDF1 in granulosa cells. The 1,979–2,077 site of lncPrep + 96kb 2.2 kb contributes to the ability to bind to EDF1.

Ginkgo Biloba Extract in Ophthalmic and Systemic Disease, With a Focus on Normal-Tension Glaucoma

Glaucoma is a neurodegenerative eye disease that results in retinal ganglion cell loss and ultimately loss of vision. Elevated intraocular pressure (IOP) is the most common known risk factor for retinal ganglion cell damage and visual field loss, and the only modifiable risk factor proven to reduce the development and progression of glaucoma. This has greatly influenced our approach and assessment in terms of diagnosis and treatment. However, as many as ≥50% of patients with progressive vision loss from primary open angle glaucoma without IOP elevation (≤22 mm Hg) have been reported in the United States and Canada; 90% in Japan and 80% in Korea. Extensive research is currently underway to identify the etiology of risk factors for glaucoma other than or in addition to elevated IOP (so-called "normal-tension" glaucoma; NTG) and use this knowledge to expand available treatment options. Currently, Food and Drug Administration-approved medications for glaucoma exclusively target elevated IOP, suggesting the need for additional approaches to treatment options beyond the current scope as the definition of glaucoma changes to encompass cellular and molecular mechanisms. This review focuses on alternative medical approaches, specifically Ginkgo Biloba extract, as a potential treatment option for normal-tension glaucoma.

Leptin induced in vitro development of ovarian follicles in sheep is related to the expression of P450 aromatase and steroidogenesis

The objective of this study was to test the hypothesis that Leptin induced in vitro growth in preantral follicles in sheep involves modulation of P450 aromatase expression and steroidogenesis. Accordingly, the expression of P450 aromatase gene was studied in the cumulus cells and oocytes isolated from different stages of preantral follicles (PFs') grown in vivo, cultured in TCM 199B, TCM 199B + Leptin (10 ng/ml) (TCM199BL) or a standard PF culture medium supplemented with Leptin (10 ng/ml) (SML). Ovarian follicles grown in vivo or in SML expressed P450 aromatase both in cumulus cells and oocytes at all the development stages. In the oocytes from PFs' grown in vitro, P450 expression was consistently lower than in those from in vivo grown follicles at all except the preantral stage. The patterns of expression of aromatase gene in the cumulus cells from in vivo grown and the PFs' cultured in TCM 199BL were similar. Significantly higher levels of progesterone production were supported by SML at all the development stages than the other two media. Oestradiol concentration in the spent TCM 199B and SML showed a significant increase as the development progressed from preantral to large antral stage. However, such increase was not sustained beyond early antral stage in the PFs' cultured in TCM199BL. It is concluded that Leptin modulates the expression P450 aromatase while supporting the in vitro development of the ovarian follicles in sheep.

Intergenerational response of steroidogenesis-related genes to maternal malnutrition

We sought to examine whether rat maternal food restriction (MFR) affects the expression of steroidogenesis-related genes Cyp19, Cyp17a1, Insl3 and Gdf-9 in the ovaries of offspring from the first (FRG1) and second (FRG2) generations at pre-pubertal age (week 4) and during adulthood (week 8). At week 4, MFR significantly increased the expression of RNAs for all analyzed genes in both FRG1 and FRG2 females, which may indicate that MFR affects the onset of the reproductive lifespan, by inducing early pubertal onset. At week 8, the Cyp19 gene was still upregulated in MRF-subjected animals (Cyp19: P=0.0049 and P=0.0508 in FRG1 and FRG2, respectively), but MFR induced a significant decrease in Cyp17 and Gdf-9 gene expression in the offspring of both FRG1 and FRG2 females when compared with the controls (Cyp17: P=0.0018 and P=0.0016, respectively; Gdf-9: P=0.0047 and P=0.0023, respectively). This suggests that females at week 8, which should normally be in their optimal reproductive capacity, experience premature ovarian aging. At week 4, the activation of Cyp19 and Cyp17 was higher in the FRG1 ovaries than in the FRG2 ovaries, whereas the extent of Insl3 and Gdf-9 activation was lower in the FRG1 ovaries. This may indicate that FRG2 females were more vulnerable to MFR than their mothers (FRG1) and grandmothers, which is consistent with the 'predictive adaptive response' hypothesis. Our findings reveal that MFR may induce intergenerational ovarian changes as an adaptive response to ensure reproductive success before death.

Quantitative analysis of long-form aromatase mRNA in the male and female rat brain

In vitro studies show that estrogens acutely modulate synaptic function in both sexes. These acute effects may be mediated in vivo by estrogens synthesized within the brain, which could fluctuate more rapidly than circulating estrogens. For this to be the case, brain regions that respond acutely to estrogens should be capable of synthesizing them. To investigate this question, we used quantitative real-time PCR to measure expression of mRNA for the estrogen-synthesizing enzyme, aromatase, in different brain regions of male and female rats. Importantly, because brain aromatase exists in two forms, a long form with aromatase activity and a short form with unknown function, we targeted a sequence found exclusively in long-form aromatase. With this approach, we found highest expression of aromatase mRNA in the amygdala followed closely by the bed nucleus of the stria terminalis (BNST) and preoptic area (POA); we found moderate levels of aromatase mRNA in the dorsal hippocampus and cingulate cortex; and aromatase mRNA was detectable in brainstem and cerebellum, but levels were very low. In the amygdala, gonadal/hormonal status regulated aromatase expression in both sexes; in the BNST and POA, castration of males down-regulated aromatase, whereas there was no effect of estradiol in ovariectomized females. In the dorsal hippocampus and cingulate cortex, there were no differences in aromatase levels between males and females or effects of gonadal/hormonal status. These findings demonstrate that long-form aromatase is expressed in brain regions that respond acutely to estrogens, such as the dorsal hippocampus, and that gonadal/hormonal regulation of aromatase differs among different brain regions.

Effects of electro-acupuncture on ovarian P450arom, P450c17α and mRNA expression induced by letrozole in PCOS rats

Hyperandrogenism is a core factor in the series of reproductive and endocrine metabolic disorders involved in polycystic ovary syndrome (PCOS). Abnormalities in enzymatic activity and the expression of ovarian granular cell layer P450arom and theca cell P450c17α can lead to an atypical environment of local ovarian hormones, including excessive androgen levels. Rat models prepared with letrozole exhibit similar endocrine and histological changes to those that occur in human PCOS. We used such a model to study the role of electro-acupuncture (EA) in regulating ovarian P450arom and P450c17α enzymatic activity and mRNA expression in PCOS rats. Female Sprague Dawley (SD) rats aged 42 days were randomly divided into 3 groups (control, PCOS, and PCOS EA) consisting of 10 rats each. The PCOS and PCOS EA groups were administered a gavage of 1.0 mg/kg(-1) of letrozole solution once daily for 21 consecutive days. Beginning in the ninth week, the PCOS EA group was administered low-frequency EA treatment daily for 14 consecutive days. After the treatment, we obtained the following results. The estrous cycles were restored in 8 of the 10 rats in the PCOS EA group, and their ovarian morphologies and ultrastructures normalized. The peripheral blood measurements (with ELISA) showed significantly decreased androgens (i.e., androstenedione and testosterone) with significantly increased estrogens (i.e., estrone, estradiol) and increased P450arom with decreased P450C17α. Immunohistochemistry and Western blotting methods showed enhanced expression of ovarian granular cell layer P450arom as well as decreased expression of theca cell layer P450C17α. Fluorescence quantitative PCR methods showed enhanced expression of ovarian granular cell layer P450arom mRNA as well as decreased expression of theca cell layer P450C17α mRNA. These results may help explain the effects of electro-acupuncture in changing the local ovarian hyperandrogenic environment and improving reproductive and endocrine metabolic disorders in PCOS.

Development of podocyte injuries in Osborne-Mendel rats is accompanied by reduced expression of podocyte proteins

Osborne-Mendel (OM) rats spontaneously develop glomerulopathy with progressive podocyte injury. Changes in protein expression levels in the foot processes of podocytes have been suggested to play an important role in the development of renal disease. The aim of this study was to investigate the temporal relationship between the expression of five podocyte proteins (nephrin, podocin, synaptopodin, α-actinin-4 and α3-integrin) and the development of podocyte injuries, proteinuria and glomerulosclerosis in OM rats. Male OM rats 5-20 weeks of age and age-matched Fischer 344 rats were used. Semiquantitative analysis of expression of the five podocyte proteins was performed by immunofluorescence labelling. Nephrin mRNA expression was determined by quantitative real-time reverse transcriptase polymerase chain reaction and nephrin protein expression was determined by mass spectrometry. Progressive reduction in expression of the podocyte proteins correlated with the progression of podocyte injuries, the development of proteinuria and the subsequent development of glomerulosclerosis. Nephrin mRNA expression and nephrin concentration also showed temporal decreases in OM rats. Altered expression of podocyte proteins preceded the development of proteinuria and glomerulosclerosis, suggesting that this event contributes to podocyte dysfunction and progression to glomerulosclerosis.

Transitional gene expression profiling in ovarian follicle during ovulation in normal-cycle rats

Evaluation of ovarian toxicity requires an understanding of the physiological changes related to the estrous cycle in the ovary. The authors investigated the transitional gene expression profile of ovulatory follicles in rats that show normal estrous cyclicity. Ovaries were collected at 10:00 and 22:00 on the proestrus day and at 10:00 on the estrus day. Ovarian follicles or early corpora lutea were isolated using laser microdissection, and extracted total RNA was analyzed using microarray technology. Clustering analysis revealed four different expression patterns: transient up- or down-regulation only at 22:00 on the proestrus day (pattern 1), up- or down-regulation only at 10:00 on the estrus day (pattern 2), continuous increase at 22:00 on the proestrus day and at 10:00 on the estrus day (pattern 3), and up- or down-regulation at 22:00 on the proestrus day and level maintenance at 10:00 on the estrus day (pattern 4). In addition, these probe sets were functionally categorized in each pattern using the Ingenuity Pathways Analysis database. These data will aid in understanding the physiology of ovulation and may be useful in assessing ovarian toxicity and its mechanism, such as in investigations of chemical-induced ovulatory impairment.

Comparison of aryl hydrocarbon receptor gene expression in laser dissected granulosa cell layers of immature rat ovaries

In order to understand ovarian toxicity of aryl hydrocarbon receptor (AhR) agonists, in situ gene expression of the AhR was examined during follicle development in immature rats. In situ hybridization on frozen sections of ovaries from 24-day-old Sprague-Dawley rats showed that the AhR mRNA was localized in the granulosa cells and occasionally in the theca cells of the follicles irrespective of the developmental stage. In situ gene quantification on granulosa cell layers collected by laser microdissection further revealed that the granulosa cells expressed less AhR mRNA according to development of belonging follicles, but more β-subunit of inhibin A mRNA, a quality control gene. These results may help to elucidate vulnerable developmental stages of follicles to toxicities of the AhR agonists.

Detection of Bcl-2 mRNA and its product in the glomerular podocytes of the normal rat kidney

Podocyte apoptosis underlies podocytepenia leading to glomerulosclerosis. An apoptosis inhibitory protein Bcl-2 is expressed in the podocytes in the early stage of nephrogenesis and downregulated in the maturing stage of human fetal kidneys. Recent studies reported changed localization and expression of Bcl-2 in the renal glomeruli under the pathologic conditions. This study aimed to confirm in situ localization of Bcl-2 mRNA and its product in the glomeruli, and to demonstrate the local expression of Bcl-2 mRNA in normal rat glomeruli. Paraffin sections of the kidneys from normal male Wistar rats were immunostained by anti-Bcl-2 monoclonal antibody. The localization of Bcl-2 mRNA in the glomeruli was evaluated by in situ hybridization. The glomeruli were dissected from frozen sections of the kidneys with the laser microdissection (LMD) system. Total RNA extracted from 10, 100 or 200 dissected glomeruli was used for reverse-transcription polymerase chain reaction (RT-PCR) and real-time PCR. Bcl-2 mRNA and its product were detected in the podocytes but barely in the mesangial cells. In RT-PCR, the specific-sized bands of Bcl-2 from 100 or 200 dissected glomeruli were clearly observed. Real-time PCR for Bcl-2 showed that cDNA from 100 or 200 dissected glomeruli became amplified at 36 or 33cycles, respectively. Bcl-2 is expressed in the glomerular podocytes of the normal rat kidney and quantitative analysis of Bcl-2 mRNA in the renal glomeruli is possible using the LMD technique.

Application of laser-assisted microdissection for gene expression analysis of mammalian germ cells

Laser-assisted microdissection (LAM) is an important method to provide new significant insights into many embryological processes. To understand these processes, it is important to obtain specific populations of cells from complex tissue in an efficient and precise manner and to combine with many different molecular biological methods. During the last few years, the sophistication of the techniques of LAM has increased significantly and made the procedure easy to use. New micro-extraction protocols for DNA, RNA and proteins now allow broad downstream applications in the fields of genomics, transcriptomics and proteomics. In this review, we give a short overview of the application of LAM in combination with quantitative qPCR for the analysis of gene expression in mammalian germ cells.

Collaborative work on evaluation of ovarian toxicity. 8) Two- or four-week repeated-dose studies and fertility study of Anastrozole in female rats

The main focus of this study was to determine the optimal administration period in terms of toxic effects on ovarian morphological changes. To assess the morphological and functional changes induced by anastrozole in ovaries, the compound was administered to female rats at dose levels or 0, 0.01, 0.1 and 50 mg/kg for 2 or 4 weeks in the repeated dose toxicity study and at levels of 0, 0.01, 0.1 and 5 mg/kg from 2 weeks prior to mating to Day 7 or pregnancy in the female fertility study. In the repeated dose toxicity study, large abnormal atretic follicles, follicular cysts, a decrease in corpus luteum and depletion of developing corpus luteum were observed in the 1 and/or 50 mg/kg groups of both the 2-week and 4-week studies in a histopathological examination of the ovaries. In the female fertility study, the pregnancy rate was decreased in the 5 mg/kg group. Irregular estrous cycles, such as an extended cycle or no cycle, were observed in the 0.1 and 5 mg/kg groups. At necropsy, decreased numbers of implantations, corpora lutea and live fetuses were noted in the 1 and/or 5 mg/kg groups. Based on these findings, histopathological changes in the ovary are important endpoints for the evaluation of drugs inducing ovarian damage. We conclude that a 2-week administration period is sufficient to detect ovarian toxicity of anastrozole in a repeated dose toxicity study.

Aromatase expression in the ovary: hormonal and molecular regulation

Estrogens are synthesized by the aromatase enzyme encoded by the Cyp19a1 gene, which contains an unusually large regulatory region. In most mammals, aromatase expression is under the control of two distinct promoters a gonad- and a brain-specific promoter. In humans, this gene contains 10 tissue-specific promoters that are alternatively used in various cell types and tumors. Each promoter is regulated by a distinct set of regulatory sequences and transcription factors that bind to these specific sequences. The cAMP/PKA/CREB pathway is considered to be the primary signaling cascade through which the gonad Cyp19 promoter is regulated. Very interestingly, in rat luteal cells, the proximal promoter is not controlled in a cAMP dependent manner. Strikingly, these cells express aromatase at high levels similar to those found in preovulatory follicles, suggesting that alternative and powerful mechanisms control aromatase expression in luteal cells and that the rat corpus luteum represents an important paradigm for understanding alternative controls of the aromatase gene. Here, the molecular and cellular mechanisms controlling the expression of the aromatase gene in granulosa and luteal cells are discussed.

Recent progress in histochemistry

The progress in discerning the structure and function of cells and tissues in health and disease has been achieved to a large extent by the continued development of new reagents for histochemistry, the improvement of existing techniques and new imaging techniques. This review will highlight some advancements made in these fields.

Effects of Vertically Transferred 3,3',4,4',5-Pentachlorobiphenyl on Gene Expression in the Ovaries of Immature Sprague-Dawley Rats

We have previously shown that 3,3',4,4',5-pentachlorobiphenyl (PCB-126) vertically transferred from dams potentially exerts a direct effect on the ovaries of offspring and adversely affects female puberty. To investigate its toxicological targets in ovarian tissues, mRNAs encoding representative peptides that regulate follicular development in granulosa cells, theca cells, and oocytes were quantified using ovaries collected on postnatal days (PND) 5, 15, and 24 from the offspring of dams administered oral doses of 0, 1 or 3 microg/kg PCB-126 starting 2 weeks prior to mating and continuing until 20 days after delivery. Quantification using the real-time RT-PCR method revealed that PCB-126 lowered the amounts of mRNAs that encoded the inhibin alpha- and inhibin/activin beta A-subunits from PND 15 onwards; the amounts of mRNAs for inhibin/activin beta B-subunit, follicle-stimulating hormone (FSH) receptor, and aromatase on PND 15; and the amounts of luteinizing hormone receptor mRNA on PND 24 compared with those of the age-matched controls. In contrast, no differences were noted for mRNAs encoding c-kit, growth differentiation factor-9, bone morphogenetic protein-15, or kit ligand for any of the age groups examined. The serum FSH level on PND 24 was higher than that in the control. Since the earliest effects on the mRNAs in the rat ovaries were observed in those expressed in the granulosa cells of the growing follicles after the antral follicles had developed, molecules in granulosa cells but not in oocytes during the early stages of the antral follicles might be the primary targets of vertically transferred PCB-126.

The histochemistry and cell biology vade mecum: a review of 2005–2006

The procurement of new knowledge and understanding in the ever expanding discipline of cell biology continues to advance at a breakneck pace. The progress in discerning the physiology of cells and tissues in health and disease has been driven to a large extent by the continued development of new probes and imaging techniques. The recent introduction of semi-conductor quantum dots as stable, specific markers for both fluorescence light microscopy and electron microscopy, as well as a virtual treasure-trove of new fluorescent proteins, has in conjunction with newly introduced spectral imaging systems, opened vistas into the seemingly unlimited possibilities for experimental design. Although it oftentimes proves difficult to predict what the future will hold with respect to advances in disciplines such as cell biology and histochemistry, it is facile to look back on what has already occurred. In this spirit, this review will highlight some advancements made in these areas in the past 2 years.