Fibroblast growth factor 9 activates akt and MAPK pathways to stimulate steroidogenesis in mouse leydig cells

FGF9 promotes cell proliferation and tumorigenesis in TM3 mouse Leydig progenitor cells

Fibroblast growth factor 9 (FGF9) modulates cell proliferation, differentiation and motility for development and tissue repair in normal cells. Growing evidence shows that abnormal activation of FGF9 signaling is associated with tumor malignancy. We have previously reported that FGF9 increases MA-10 mouse Leydig tumor cell proliferation, in vitro, and tumor growth, in vivo. Also, FGF9 promotes the tumor growth and liver metastasis of mouse Lewis lung cancer cells, in vivo. However, the effects of FGF9 in the early stage of tumorigenesis remains elusive. In this study, TM3 mouse Leydig progenitor cells, that are not tumorigenic in immunocompromised mice, were used as a model cell line to investigate the role of FGF9 in tumorigenesis. The results demonstrated that FGF9 significantly induced cell proliferation and activated the MAPK, PI3K and PLCγ signaling pathways in TM3 cells. The percentage of the cell number in G1 phase was reduced and that in S and G2/M phases was increased after FGF9 stimulation in TM3 cells. Cyclin D1, cyclin A1, CDK2, CDK1, and p21 expressions and the phosphorylation level of Rb were all induced in FGF9-treated TM3 cells. In addition, FGF9 increased the expression of FGF receptor 1-4 in TM3 cells, suggesting the positive feedback loop between FGF9 and FGFRs. Furthermore, in the allograft mouse model, FGF9 promoted the tumorigenesis of TM3 cells characterized by higher expression of tumor markers, such as tumor necrosis factor alpha (TNFα) and α-fetoprotein (AFP), in the subcutaneously inoculated TM3 cell tissue. Conclusively, FGF9 induced cell cycle to increase cell proliferation of TM3 cells through FAK, MAPK, PI3K/Akt and PLCγ signaling pathways, in vitro, and promoted the tumorigenesis of TM3 cell allograft tissue, in vivo, which is a potential marker for tumor as well as a target for cancer therapeutic strategies.

Egfr signaling promotes juvenile hormone biosynthesis in the German cockroach

BACKGROUND

In insects, an interplay between the activities of distinct hormones, such as juvenile hormone (JH) and 20-hydroxyecdysone (20E), regulates the progression through numerous life history hallmarks. As a crucial endocrine factor, JH is mainly synthesized in the corpora allata (CA) to regulate multiple physiological and developmental processes, including molting, metamorphosis, and reproduction. During the last century, significant progress has been achieved in elucidating the JH signal transduction pathway, while less progress has been made in dissecting the regulatory mechanism of JH biosynthesis. Previous work has shown that receptor tyrosine kinase (RTK) signaling regulates hormone biosynthesis in both insects and mammals. Here, we performed a systematic RNA interference (RNAi) screening to identify RTKs involved in regulating JH biosynthesis in the CA of adult Blattella germanica females.

RESULTS

We found that the epidermal growth factor receptor (Egfr) is required for promoting JH biosynthesis in the CA of adult females. The Egf ligands Vein and Spitz activate Egfr, followed by Ras/Raf/ERK signaling, and finally activation of the downstream transcription factor Pointed (Pnt). Importantly, Pnt induces the transcriptional expression of two key enzyme-encoding genes in the JH biosynthesis pathway: juvenile hormone acid methyltransferase (JHAMT) and methyl farnesoate epoxidase (CYP15A1). Dual-luciferase reporter assay shows that Pnt is able to activate a promoter region of Jhamt. In addition, electrophoretic mobility shift assay confirms that Pnt directly binds to the - 941~ - 886 nt region of the Jhamt promoter.

CONCLUSIONS

This study reveals the detailed molecular mechanism of Egfr signaling in promoting JH biosynthesis in the German cockroach, shedding light on the intricate regulation of JH biosynthesis during insect development.

Identification and Characterization of Sex-Biased miRNAs in the Golden Pompano (Trachinotus blochii)

The golden pompano (Trachinotus blochii) is a marine fish of considerable commercial importance in China. It shows notable sexual size dimorphism; the growth rate of females is faster than that of males. Therefore, sex-biased research is of great importance in T. blochii breeding. However, there have been few studies on sex differentiation and mechanisms underlying sex determination in T. blochii. MicroRNAs (miRNAs) play crucial roles in sex differentiation and determination in animals. However, limited miRNA data are available on fish. In this study, two small RNA libraries prepared from the gonads of T. blochii were constructed and sequenced. The RNA-seq analysis yielded 1366 known and 69 novel miRNAs with 289 significantly differentially expressed miRNAs (p < 0.05). Gene ontology (GO) analysis confirmed that the TFIIA transcription factor complex (GO: 0005672) was the most significantly enriched GO term. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the differentially expressed miRNAs and target genes were mainly related to sex determination and gonadal developmental signaling pathways, specifically the Wnt signaling pathway, MAPK signaling pathway, and steroid biosynthetic pathway. MiRNA-mRNA co-expression network analysis strongly suggested a role for sex-biased miRNAs in sex determination/differentiation and gonadal development. For example, gata4, foxo3, wt1, and sf1 genes were found to be regulated by bta-miR-2898; esr2 and foxo3 by novel_176, and ar by oar-let-7b. Quantitative real-time polymerase chain reaction analysis of selected mRNAs and miRNAs validated the integrated analysis. This study established a set of sex-biased miRNAs that are potential regulatory factors in gonadal development in T. blochii. These results provide new insight into the function of miRNAs in sex differentiation and determination in T. blochii and highlight some key miRNAs for future studies.

HSD3B1 Expression Is Upregulated by Interleukin 4 in HT-29 Colon Cancer Cells via Multiple Signaling Pathways

3β-Hydroxysteroid dehydrogenase/isomerase is essential for the synthesis of active steroid hormones. Interleukin 4 (IL4) induces the expression of HSD3B1 in various human cancer cell lines. Here, we demonstrated that administration of IL4 to an HT-29 colon cancer cell line induced high expression of HSD3B1 at the mRNA and protein levels. In the HT-29 cells, IL4 stimulated the activity of signal transducer and activator of transcription 6 (STAT6) and promoted its binding to the STAT6-binding site in the HSD3B1 promoter. The STAT6 inhibitor significantly suppressed HSD3B1 induction by IL4 in a dose-dependent manner. Moreover, inhibition of the PI3-kinase/AKT pathway strongly suppressed the IL4-induced HSD3B1 expression. Glycogen synthase kinase 3 (GSK3), a downstream target of AKT, had a stimulatory effect on the IL4-induced HSD3B1 expression. However, IL4 stimulated the phosphorylation of AKT, which inhibited the GSK3 activity at the early stage. Hence, GSK3 potentiated the HSD3B1 levels at the late stage of the IL4 stimulation. Additionally, inhibitors of mitogen-activated protein kinases (MAPKs), ERK1/2 and p38, but not of JNK, partly reduced the HSD3B1 expression following the IL4 stimulation. We further demonstrated that IL4 potently promoted steroid synthesis. Our results indicate that IL4 induces HSD3B1 expression via multiple signaling pathways in HT-29 cells and may play a role in the regulation of steroid synthesis.

Identification and Characterization of lncRNA and mRNA in Testes of Landrace and Hezuo Boars

Simple Summary

Precocious puberty is an excellent reproductive trait in domestic animals, which can generate higher breeding benefits in livestock production. However, regulators associated with this sexual maturation process remain largely unknown. Chinese Hezuo (HZ) boars are known for their early sexual maturity. In this work, the characteristics of precocious puberty in HZ pigs were confirmed by histological analysis, and some important long noncoding RNA (lncRNA) and mRNA were identified in the testes of immature (30-day-old) and mature (120-day-old) HZ boars, which could play a key role in precocious puberty. These results will provide a theoretical basis for further research on the regulatory mechanism of precocious puberty, which is important for accelerating the breeding process of highly fertile animals.

Abstract

Chinese HZ boars are typical plateau miniature boars characterized by precocious puberty, which is closely related to testicular development and spermatogenesis. Accumulating evidence indicates that lncRNA is involved in the testicular development and regulation of spermatogenesis. However, little is known about the lncRNA precocious regulation in testicular development and spermatogenesis on early sexual maturity of HZ boars. Thus, we investigated the expression and characterization of lncRNA and mRNA in 30-day-old and 120-day-old HZ boar testes using transcriptome to explore precocious puberty. Landrace (LC) boar was treated as the control. Histological analyses indicated that HZ boar underwent puberty development at an earlier stage than LC boar and had achieved sexual maturity at 120 days old. RNA-Seq yielded a total of 187 lncRNAs and 984 mRNAs; these molecules were identified as possible candidates for precocious puberty. GO terms and KEGG pathways enrichment analyses revealed that the differentially expressed lncRNA and their targeted genes were involved in metabolic pathways regulating testis development and spermatogenesis, such as the PI3K-Akt, TGF-beta and Wnt pathways. Further screening, some lncRNA (such as LOC102166140, LOC110259451, and MSTRG.15011.2), and mRNA (such as PDCL2, HSD17B4, SHCBP1L, CYP21A2, and SPATA3) were found to be possibly associated with precocious puberty, which would add to our understanding of the molecular regulatory mechanisms of precocious puberty. This study provided valuable information for further study of the role of lncRNA and mRNA in the process of precocious puberty.

Cytoarchitectural improvement in Leydig cells of diabetic rats after treatment with aqueous and ethanol extracts of Dracaena arborea (Dracaenaceae)

BACKGROUND AND AIM

Recent studies have demonstrated the androgenic effects of Dracaena arborea in castrated and diabetic rats, but the cytoarchitectural mechanism at the level of Leydig cells (LCs) justifying this improvement in androgens production in diabetic rats has never been examined. We investigated the effects of aqueous and ethanol extracts of D. arborea on diabetes-induced cytoarchitectural impairments of LCs in rats.

EXPERIMENTAL PROCEDURE

Besides a normal group, 4 groups of diabetic rats were treated orally with Millipore water (10 ml/kg, diabetic), sildenafil citrate (1.44 mg/kg), aqueous (500 mg/kg) and ethanol (100 mg/kg) extracts of D. arborea for 21 days. On day 22, rats were sacrificed and the testes were removed and prepared for electron microscopic analyses of LCs ultrastructure.

RESULTS AND CONCLUSION

The ultrastructure of LCs in control rats was normal, while that in diabetic rats exhibited large heterochromatization in the nuclei, reduced amount of smooth endoplasmic reticulum with no lipid droplets in the cytoplasm, many autophagosomes and degenerated mitochondria containing lots of electron dense granules in the matrix. Interestingly, treatment with D. arborea especially its aqueous extract (500 mg/kg) alleviated these impairments, characterized by a rarification of heterochromatization in the nuclei coupled to an increase and the presence in the cytoplasm of prominent smooth endoplasmic reticulum and a reduction of electron dense granules in the matrix of mitochondria. These alleviating properties of D. arborea on LCs ultrastructure of diabetic rats could explain its androgenic potential. These results are useful for the management of patients suffering from diabetes-induced hypogonadism.

Chemerin Impairs In Vitro Testosterone Production, Sperm Motility, and Fertility in Chicken: Possible Involvement of Its Receptor CMKLR1

The chemokine chemerin is a novel adipokine involved in the regulation of energy metabolism but also female reproductive functions in mammals. Its effects on male fertility are less studied. Here, we investigated the involvement of chemerin in chicken male reproduction. Indeed, the improvement of the sperm of roosters is a challenge for the breeders since the sperm quantity and quality have largely decreased for several years. By using specific chicken antibodies, here we show that chemerin and its main receptor CMKLR1 (chemokine-like receptor 1) are expressed within the chicken testis with the lowest expression in adults as compared to the embryo or postnatal stages. Chemerin and CMKLR1 are present in all testicular cells, including Leydig, Sertoli, and germinal cells. Using in vitro testis explants, we observed that recombinant chicken chemerin through CMKLR1 inhibits hCG (human chorionic gonadotropin) stimulated testosterone production and this was associated to lower 3βHSD (3beta-hydroxysteroid dehydrogenase) and StAR (steroidogenic acute regulatory protein) expression and MAPK ERK2 (Mitogen-Activated Protein Kinase Extracellular signal-regulated kinase 2) phosphorylation. Furthermore, we demonstrate that chemerin in seminal plasma is lower than in blood plasma, but it is negatively correlated with the percentage of motility and the spermatozoa concentration in vivo in roosters. In vitro, we show that recombinant chicken chemerin reduces sperm mass and individual motility in roosters, and this effect is abolished when sperm is pre-incubated with an anti-CMKLR1 antibody. Moreover, we demonstrate that fresh chicken sperm treated with chemerin and used for artificial insemination (AI) in hen presented a lower efficiency in terms of eggs fertility for the four first days after AI. Taken together, seminal chemerin levels are negatively associated with the rooster fertility, and chemerin produced locally by the testis or male tract could negatively affect in vivo sperm quality and testosterone production through CMKLR1.

Genome-wide DNA methylation analysis of KRAS mutant cell lines

Oncogenic RAS mutations are associated with DNA methylation changes that alter gene expression to drive cancer. Recent studies suggest that DNA methylation changes may be stochastic in nature, while other groups propose distinct signaling pathways responsible for aberrant methylation. Better understanding of DNA methylation events associated with oncogenic KRAS expression could enhance therapeutic approaches. Here we analyzed the basal CpG methylation of 11 KRAS-mutant and dependent pancreatic cancer cell lines and observed strikingly similar methylation patterns. KRAS knockdown resulted in unique methylation changes with limited overlap between each cell line. In KRAS-mutant Pa16C pancreatic cancer cells, while KRAS knockdown resulted in over 8,000 differentially methylated (DM) CpGs, treatment with the ERK1/2-selective inhibitor SCH772984 showed less than 40 DM CpGs, suggesting that ERK is not a broadly active driver of KRAS-associated DNA methylation. KRAS G12V overexpression in an isogenic lung model reveals >50,600 DM CpGs compared to non-transformed controls. In lung and pancreatic cells, gene ontology analyses of DM promoters show an enrichment for genes involved in differentiation and development. Taken all together, KRAS-mediated DNA methylation are stochastic and independent of canonical downstream effector signaling. These epigenetically altered genes associated with KRAS expression could represent potential therapeutic targets in KRAS-driven cancer.

Deletion of inositol polyphosphate 4-phosphatase type-II B affects spermatogenesis in mice

Inositol polyphosphate-4-phosphatase type II (INPP4B) is a dual-specificity phosphatase that acts as a tumor suppressor in multiple cancers. INPP4B dephosphorylates phospholipids at the 4th position of the inositol ring and inhibits AKT and PKC signaling by hydrolyzing of PI(3,4)P2 and PI(4,5)P2, respectively. INPP4B protein phosphatase targets include phospho-tyrosines on Akt and phospho-serine and phospho-threonine on PTEN. INPP4B is highly expressed in testes, suggesting its role in testes development and physiology. The objective of this study was to determine whether Inpp4b deletion impacts testicular function in mice. In testis, Inpp4b expression was the highest in postmeiotic germ cells in both mice and men. The testes of Inpp4b knockout male mice were significantly smaller compared to the testes of wild-type (WT) males. Inpp4b^-/- males produced fewer mature sperm cells compared to WT, and this difference increased with age and high fat diet (HFD). Reduction in early steroidogenic enzymes and luteinizing hormone (LH) receptor gene expression was detected, although androgen receptor (AR) protein level was similar in WT and Inpp4b^-/- testes. Germ cell apoptosis was significantly increased in the knockout mice, while expression of meiotic marker γH2A.X was decreased. Our data demonstrate that INPP4B plays a role in maintenance of male germ cell differentiation and protects testis functions against deleterious effects of aging and high fat diet.

Phenylethanol glycosides from Cistanche tubulosa improved reproductive dysfunction by regulating testicular steroids through CYP450-3β-HSD pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Cistanche tubulosa (Schenk) R. Wight has been used frequently in traditional folk medicine for treatment of male sexual dysfunction (MSD). Phenylethanol glycosides, the main components of C. tubulosa, possess a variety of pharmacological activities due to their multiple properties. However, the underlying mechanism by which phenylethanol glycosides from C. tubulosa (CPhGs) regulates testicular steroids has not been elucidated to date.

AIM OF THE STUDY

This study is to determine whether CPhGs promotes the reproductive functions of mice through CYP450-3β-HSD pathway of testosterone synthesis.

MATERIALS AND METHODS

The major compositions of C. tubulosa (CPhGs) were quantified by high performance liquid chromatography (HPLC). The model of reproductive injury in mice were induced by injection of hydrocortisone (HCT). Different doses of CPhGs (72, 145 and 289 mg/kg) and testosterone propionate (TP, positive control drug) were administrated intragastrically for 14 d. The reproductive functions (erectile incubation period, capture and ejaculation incubation period, number of captures and ejaculations) and organ weights (testicle, epididymis, seminal vesicle and penis) were then determined. The levels of luteinizing hormone and testosterone in serum were quantified by radioimmunoassay. The key enzymes in testosterone synthesis pathways such as steroidogenic acute regulatory protein (StAR), cytochrome P450 cholesterol side chain cleavage enzyme (P450scc/CYP11A1) and 3β-hydroxysteroid dehydrogenase (3β-HSD) in the testis were assessed by immunofluorescence (IF) staining or/and Western blot (WB) analysis.

RESULTS

The results illustrated that the low dose of CPhGs (72 mg/kg) had no significant protective effect against the reproductive injury caused by HCT, while the moderate dose of CPhGs (145 mg/kg) improved the damaged reproductive ability and the declined levels of luteinizing hormone and testosterone in the model mice (P < 0.001, P < 0.05, respectively). In particular, high dose of CPhGs (289 mg/kg) was most effective in improving HCT-induced changes in body weight (P < 0.01), reducing the incubation period of the erectile (P < 0.001), capture (P < 0.05) and ejaculation (P < 0.01), and increasing the number of captures and ejaculations (P < 0.01, P < 0.05, respectively). The weights of testcle, epididymis, seminal vesicle and penis (P < 0.001, P < 0.01, P < 0.01, P < 0.001, respectively) were improved by high dose of CPhGs. The levels of testosterone and its upstream luteinizing hormone were up-regulated by high dose of CPhGs (P < 0.001). Meanwhile, the expressions of the key steroidogenic enzymes including CYP11A1 and 3β-HSD were significantly up-regulated after CPhGs treatment (P < 0.001), demonstrated that CPhGs exerted the effect through enhancing testosterone biosynthesis via CYP450-3β-HSD pathway.

CONCLUSIONS

CPhGs could significantly protect against HCT-induced deleterious reproductive dysfunction and testis injury. The protective effects were exerted by up-regulating synthesis of testosterone via the CYP450-3β-HSD pathway in Leydig cells.

Propofol Inhibits Androgen Production in Rat Immature Leydig Cells

Background: Propofol is a widely used anesthetic. Whether propofol inhibits androgen production by rat Leydig cells and the underlying mechanism remains unclear. The objective of the current study was to examine the effects of propofol exposure to rat primary immature Leydig cells and to define propofol-induced inhibition of steroidogenic enzymes in both rat and human testes in vitro.

Methods: Immature Leydig cells were purified from 35-day-old male Sprague–Dawley rats and were exposed to propofol for 3 h. The androgen production by Leydig cells under basal, luteinizing hormone, 8bromo-cAMP, and steroid-substrate stimulated conditions and gene expression of Leydig cells after exposure to propofol were measured. Immature Leydig cells were treated with propofol for 3 h and switched to propofol-free medium for additional 3 and 9 h to test whether propofol-induced inhibition is reversible. ³H-Steroids were used to evaluate the direct action of propofol on cytochrome P450 cholesterol side chain cleavage (CYP11A1), 3β-hydroxysteroid dehydrogenase (HSD3B), cytochrome P450 17α-hydroxylase/17,20-lyase (CYP17A1), and 17β-hydroxysteroid dehydrogenase 3 (HSD17B3) activities in rat and human testes in vitro.

Results: Propofol significantly lowered luteinizing hormone and 8bromo-cAMP stimulated androgen production by Leydig cells after 3-h exposure. Further investigation showed that propofol down-regulated the expression of Cyp11a1 and Cyp17a1 and their proteins at 5 and 50 µM, although it up-regulated Lhcgr expression at 50 µM. Propofol significantly suppressed phosphorylation of ERK1/2 and induced ROS production in immature Leydig cells at 5 and 50 µM. Propofol significantly induced apoptosis of immature Leydig cells at 50 µM. Propofol specifically inhibited rat and human testis HSD3B activities in vitro. The half maximal inhibitory concentrations of propofol for rat and human HSD3B enzymes were 1.011 ± 0.065 and 3.498 ± 0.067 µM, respectively. The mode of action of propofol of inhibiting HSD3B was competitive when pregnenolone was added. At 50 µM, propofol did not directly inhibit rat and human testis CYP11A1, CYP17A1, and HSD17B3 activities in vitro.

Conclusion: Propofol inhibits androgen production via both directly inhibiting HSD3B activity and down-regulating Cyp11a1 and Cyp17a1 expression in Leydig cells. Suppression of steroidogenic enzymes is presumably associated with the lower production of androgen by Leydig cells after propofol treatment. However, propofol-induced inhibition on androgen production is reversible.

Brain-derived neurotrophic factor: A steroidogenic regulator of Leydig cells

The brain-derived neurotrophic factor (BDNF) was first recognized for its roles in the peripheral and central nervous systems, and its complex functions on mammalian organs have been extended constantly. However, to date, little is known about its effects on the male reproductive system, including the steroidogenesis of mammals. The purpose of this study was to elucidate the effects of BDNF on testosterone generation of Leydig cells and the underlying mechanisms. We found that BDNF-induced proliferation of TM3 Leydig cells via upregulation of proliferating cell nuclear antigen ( Pcna) and promoted testosterone generation as a result of upregulation of steroidogenic acute regulatory protein ( Star), 3b-hydroxysteroid dehydrogenase ( Hsd3b1), and cytochrome P450 side-chain cleavage enzyme ( Cyp11a1) both in primary Leydig cells and TM3 Leydig cells, which were all attenuated in Bdnf knockdown TM3 Leydig cells. Furthermore, the possible mechanism of testosterone synthesis was explored in TM3 Leydig cells. The results showed that BDNF enhanced extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) phosphorylation, and the effect was disrupted by Bdnf deletion. Moreover, PD98059, a potent selective inhibitor of ERK1/2 activation, compromised BDNF-induced testosterone generation and upregulation of Star, Hsd3b1, and Cyp11a1. The Bdnf knockdown assay, on the other hand, indicated the autocrine effect of BDNF on steroidogenesis in TM3 Leydig cells. On the basis of these results, we concluded that BDNF, acting as an autocrine factor, induced testosterone generation as a result of the upregulation of Star, Hsd3b1, and Cyp11a1 via stimulation of the ERK1/2 pathway.

Fibroblast growth factor 9 activates anti-oxidative functions of Nrf2 through ERK signalling in striatal cell models of Huntington's disease

Huntington's disease (HD) is a heritable neurodegenerative disorder, and has been characterized as an increase of oxidative stress in brain regions. In our previous results, we showed fibroblast growth factor 9 (FGF9) provides neuroprotective functions to suppress cell death in HD striatal cells dominantly through ERK signalling. However, whether the working mechanism of FGF9 is related to anti-oxidative stress in HD is still unknown. In this study, STHdh^Q7/Q7 (Q7) and STHdh^Q111/Q111 (Q111) striatal knock-in cell lines were used to examine the neuroprotective effects of FGF9 against oxidative stress in HD. Results show that FGF9 alleviates oxidative stress induced by starvation in Q7 and Q111 cells. The treatment of FGF9 not only induces upregulation and activation of nuclear factor erythroid 2-like 2 (Nrf2), a critical transcription factor for anti-oxidative stress, but also further upregulates its downstream targets, such as superoxide dismutase 2, gamma-glutamylcysteine synthetase and glutathione reductase. Furthermore, blockage of the Nrf2 pathway abolishes the anti-oxidative functions of FGF9, and inhibition of ERK signalling reduces the activation of the FGF9-Nrf2 pathway, resulting in higher level of oxidative stress in HD cells. These results support the neuroprotective effects of FGF9 against oxidative stress through the ERK-Nrf2 pathway, and imply one of potential strategies for therapy of HD.

MiR-145-modulated SOX9-mediated hypospadias through acting on mitogen-activated protein kinase signaling pathway

This study primarily explored how miR-145, mitogen-activated protein kinase (MAPK) signaling and a downstream transcription factor (i.e., SOX9) mediated development of hypospadias. The hypospadias tissues and preputial tissues were isolated from pediatric inpatients postoperatively. Simultaneously, the rat models of hypospadias were established, and spermatogonial stem cells were separated. The expressions of proteins that symbolized cell apoptosis and oxidative stress were quantified via western blot analysis. Furthermore, the apoptosis, proliferation, and viability of cells were evaluated by means of flow cytometry, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and colony formation assays. The results of microarray indicated miR-145 as a differentially expressed biomarker between hypospadias tissues and normal tissues (p < 0.05). Moreover, rat models of hypospadias were observed with markedly lower vitamins A and E levels, reduced expressions of proteins relevant to oxidative stress (i.e., Nrf2, HO-1, Gpx, and SOD-1), as well as enhanced Bax and cleaved caspase-3 expressions ( p < 0.05). Furthermore, SOX9 was found to be targeted by miR-145, and it was also modified by phosphorylated extracellular-regulated kinase (p-ERK), a portion of MAPK signaling ( p < 0.05). The p-ERK was significantly regulated after altering the expression of miR-145 ( p < 0.05). Moreover, activation of p-ERK and transfection of pcDNA-SOX9 could cause higher expression of apoptins and larger apoptotic proportion of cells ( p < 0.05), yet transfection of miR-145 mimic led to improved cell apoptosis and depressed cell viability ( p < 0.05). In conclusion, SOX9, which was regulated by both miR-145 and miR-145/MAPK signaling, could be involved in the pathogenesis of hypospadias.

Involvement of Activation of Mitogen-Activated Protein Kinase (MAPK)/Extracellular Signal-Regulated Kinase (ERK) Signaling Pathway in Proliferation of Urethral Plate Fibroblasts in Finasteride-Induced Rat Hypospadias

Background

We investigated the role of the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signaling pathway in finasteride-induced hypospadias rats and explored the mechanisms involved.

Material/Methods

The hypospadias model was established by intragastric administration of finasteride and confirmed by hematoxylin and eosin (HE) staining. The urethral plate fibroblasts (UPF) were obtained from normal and modeled rats and identified based upon vimentin expression. Thereafter, UPF were divided into a normal control group, a model group, a model + MAPK inhibitor group, and a model + ERK inhibitor group. Cell proliferation, apoptosis, and cell cycling of UPF were assessed. Quantitative real-time PCR and Western blot analysis were used to evaluate expression of the MAPK signaling pathway and apoptosis-related genes.

Results

HE staining confirmed that 10 mg/kg finasteride caused severe hypospadias in rats. UPFs obtained from the 10 mg/kg finasteride group showed higher proliferation and cell cycling and lower apoptosis compared with those obtained from the normal control group (P<0.05). Interestingly, a MAPK inhibitor or an ERK inhibitor could attenuate the abnormalities of cell proliferation, cycling, and apoptosis of UPF induced by finasteride. Compared with controls, the relative expression of p-MEK1/MEK1, caspase 3, and P53 in the UPF of the model group were reduced, while the relative expression of p-MAPK14/MAPK14 was increased in the cells of the model group. By contrast, a MAPK inhibitor or an ERK inhibitor could alleviate the abnormalities of MAPK/ERK signaling pathway and apoptosis-related gene expression induced by finasteride.

Conclusions

Our study reveals that the MAPK/ERK signaling pathway is involved in the regulation of proliferation, apoptosis, and cell cycling of UPFs in finasteride-induced hypospadias.

Delayed Puberty by Ziram Is Associated with Down Regulation of Testicular Phosphorylated AKT1 and SIRT1/PGC-1α Signaling

Ziram is a dimethyldithiocarbamate fungicide, which may influence the male reproductive system as a potential endocrine disruptor. We interrogated the disruption of ziram on rat progenitor Leydig cell development. Prepubertal male Sprague-Dawley rats were orally treated with 0, 2, 4, or 8 mg/kg ziram for 2 weeks. We investigated the effects of ziram on serum testosterone levels, Leydig cell number, and Leydig and Sertoli cell gene and protein expression, SIRT1/PGC-1α levels, and phosphorylation of AKT1, ERK1/2, and AMPK in vivo. We also interrogated the effects of ziram on reactive oxidative species (ROS) level, apoptosis rate, and mitochondrial membrane potential of progenitor Leydig cells in vitro. Ziram decreased serum testosterone and follicle-stimulating hormone levels, the down-regulated Leydig cell-specific gene ( Lhcgr, Scarb1, Star, Cyp17a1, and Hsd17b3), and their protein expression. However, ziram stimulated anti-Müllerian hormone production. Ziram lowered SIRT1/PGC-1α and phosphorylated protein levels of AKT1. Ziram induced ROS and apoptosis and lowered the mitochondrial membrane potential of progenitor Leydig cells in vitro. In conclusion, ziram disrupts Leydig cell development during the prepubertal period potentially through the SIRT1/PGC-1α and phosphorylated AKT1 signaling.

FGF9/FGFR2 increase cell proliferation by activating ERK1/2, Rb/E2F1, and cell cycle pathways in mouse Leydig tumor cells

Fibroblast growth factor 9 (FGF9) promotes cancer progression; however, its role in cell proliferation related to tumorigenesis remains elusive. We investigated how FGF9 affected MA‐10 mouse Leydig tumor cell proliferation and found that FGF9 significantly induced cell proliferation by activating ERK1/2 and retinoblastoma (Rb) phosphorylations within 15 minutes. Subsequently, the expressions of E2F1 and the cell cycle regulators: cyclin D1, cyclin E1 and cyclin‐dependent kinase 4 (CDK4) in G₁ phase and cyclin A1, CDK2 and CDK1 in S‐G₂/M phases were increased at 12 hours after FGF9 treatment; and cyclin B1 in G₂/M phases were induced at 24 hours after FGF9 stimulation, whereas the phosphorylations of p53, p21 and p27 were not affected by FGF9. Moreover, FGF9‐induced effects were inhibited by MEK inhibitor PD98059, indicating FGF9 activated the Rb/E2F pathway to accelerate MA‐10 cell proliferation by activating ERK1/2. Immunoprecipitation assay and ChIP‐quantitative PCR results showed that FGF9‐induced Rb phosphorylation led to the dissociation of Rb‐E2F1 complexes and thereby enhanced the transactivations of E2F1 target genes, Cyclin D1, Cyclin E1 and Cyclin A1. Silencing of FGF receptor 2 (FGFR2) using lentiviral shRNA inhibited FGF9‐induced ERK1/2 phosphorylation and cell proliferation, indicating that FGFR2 is the obligate receptor for FGF9 to bind and activate the signaling pathway in MA‐10 cells. Furthermore, in a severe combined immunodeficiency mouse xenograft model, FGF9 significantly promoted MA‐10 tumor growth, a consequence of increased cell proliferation and decreased apoptosis. Conclusively, FGF9 interacts with FGFR2 to activate ERK1/2, Rb/E2F1 and cell cycle pathways to induce MA‐10 cell proliferation in vitro and tumor growth in vivo.

Ameliorative effect of ginseng extract on phthalate and bisphenol A reprotoxicity during pregnancy in rats

Phthalates (such as DEHP) and bisphenol A (BPA) are widely used chemicals in plastics manufacturing and exert public health concerns as endocrine disrupters. This study was designed to investigate the deleterious effect of DEHP and BPA on endocrine profile of pregnant female rats and the combined treatment with ginseng extract (Panax ginseng). Seventy-two pregnant rats were divided into six groups (control, ginseng, DEHP, BPA, Gin + DEHP, and Gin + BPA), 12 females per each group. The drugs were supplemented from pregnancy day 0 until day 20. Determination of serum sex hormones (testosterone, progesterone, and estradiol) were determined on days 4, 10, and 20 of pregnancy. mRNA transcripts of STAR, HSD17B3, CYP17, AKT1, and PTEN were relatively quantified against ACTB in the ovary and placenta of days 10 and 20 pregnant females by relative quantitative polymerase-chain reaction (RQ-PCR). DEHP and BPA significantly decreased the endocrine profile of testosterone, progesterone, and estradiol of days 10 and 20 of pregnant females. Combined administration of these chemicals along with ginseng extracts has returned the hormones to normal levels when compared with the control group. The ovarian and placental CYP17 and HSD17B3 mRNA transcripts showed variable expression pattern in both tissues and they were significantly affected by DEHP and BPA administration, concomitantly correlating to STAR, AKT1, PTEN, progesterone, and testosterone levels on pregnancy days 10 and 20. The results confirm the reprotoxicity of DEHP and BPA as endocrine disruptors and indicate that ginseng could be used to alleviate the toxic effects of these chemicals.

Transcriptome profiling of bovine ovarian theca cells treated with fibroblast growth factor 9

We reported previously that fibroblast growth factor 9 (FGF9) acts as an antidifferentiation factor, stimulating proliferation of granulosa cells (GCs) and theca cells (TCs) while suppressing hormone-induced steroidogenesis of these cells. How FGF9 acts to simultaneously suppress steroidogenesis and stimulate proliferation remains to be fully elucidated. Thus, this study was undertaken to clarify the effects of FGF9 on the TC transcriptome. Ovaries were obtained from beef heifers at a local abattoir, TCs were isolated from large antral follicles, and cultured with or without 30 ng/mL of FGF9 for 24 h in the presence of LH and IGF-1. After treatment, total RNA was extracted from TC and processed for microarray using Affymetrix GeneChip Bovine Genome Arrays (n = 4/group). Transcriptome analysis comparing FGF9-treated TC with control TC using 1.3-fold cutoff, and a P < 0.05 significance level identified 355 differentially expressed transcripts, with 164 elements upregulated and 191 elements downregulated by FGF9. The ingenuity pathway analysis (IPA) was used to investigate how FGF9 treatment affects molecular pathways, biological functions, and the connection between molecules in bovine TC. The IPA software identified 346 pathways in response to FGF9 in TC involved in several biological functions and unveiled interesting relationships among genes related to cell proliferation (eg, CCND1, FZD5, and MYB), antioxidation/cytoprotection (eg, HMOX1 and NQO1), and steroidogenesis (eg, CYP11A1 and STAR). Overall, genes, pathways, and networks identified in this study painted a picture of how FGF9 may regulate folliculogenesis, providing novel candidate genes for further investigation of FGF9 functions in ovarian follicular development.

Genome-wide analysis of long non-coding RNAs and their role in postnatal porcine testis development

A comprehensive and systematic understanding of the roles of lncRNAs in the postnatal development of the pig testis has still not been achieved. In the present study, we obtained more than one billion clean reads and identified 15,528 lncRNA transcripts; these transcripts included 5032 known and 10,496 novel porcine lncRNA transcripts and corresponded to 10,041 lncRNA genes. Pairwise comparisons identified 449 known and 324 novel lncRNAs that showed differential expression patterns. GO and KEGG pathway enrichment analyses revealed that the targeted genes were involved in metabolic pathways regulating testis development and spermatogenesis, such as the TGF-beta pathway, the PI3K-Akt pathway, the Wnt/β-catenin pathway, and the AMPK pathway. Using this information, we predicted some lncRNAs and coding gene pairs were predicted that may function in testis development and spermatogenesis; these are listed in detail. This study has provided the most comprehensive catalog to date of lncRNAs in the postnatal pig testis and will aid our understanding of their functional roles in testis development and spermatogenesis.

Osteoblast-derived FGF9 regulates skeletal homeostasis

FGF9 has complex and important roles in skeletal development and repair. We have previously observed that Fgf9 expression in osteoblasts (OBs) is regulated by G protein signaling and therefore the present study was done to determine whether OB-derived FGF9 was important in skeletal homeostasis. To directly test this idea, we deleted functional expression of Fgf9 gene in OBs using a 2.3kb collagen type I promoter-driven Cre transgenic mouse line (Fgf9^OB-/-). Both Fgf9 knockout (Fgf9^OB-/-) and the Fgf9 floxed littermates (Fgf9^fl/fl) mice were fully backcrossed and maintained in an FBV/N background. Three month old Fgf9^OB-/- mice displayed a significant decrease in cancellous bone and bone formation in the distal femur and a significant decrease in cortical thickness at the TFJ. Strikingly, female Fgf9^OB-/- mice did not display altered bone mass. Continuous treatment of mouse BMSCs with exogenous FGF9 inhibited mouse BMSC mineralization while acute treatment increased the proliferation of progenitors, an effect requiring the activation of Akt1. Our results suggest that mature OBs are an important source of FGF9, positively regulating skeletal homeostasis in male mice. Osteoblast-derived FGF9 may serve a paracrine role to maintain the osteogenic progenitor cell population through activation of Akt signaling.

Fibroblast growth factor 9 (FGF9) regulation of cyclin D1 and cyclin-dependent kinase-4 in ovarian granulosa and theca cells of cattle

To determine the mechanism by which fibroblast growth factor 9 (FGF9) alters granulosa (GC) and theca (TC) cell proliferation, cell cycle proteins that regulate progression through G1 phase of the cell cycle, cyclin D1 (CCND1) and cyclin-dependent kinase-4 (CDK4; CCND1's catalytic partner), were evaluated. Ovaries were obtained from a local abattoir, GC were harvested from small (1-5 mm) and large (8-22 mm) follicles, and TC were harvested from large follicles. GC and TC were plated in medium containing 10% fetal calf serum followed by various treatments in serum-free medium. Treatment with 30 ng/mL of either FGF9 or IGF1 significantly increased GC numbers and when combined, synergized to further increase GC numbers by threefold. Abundance of CCND1 and CDK4 mRNA in TC and GC were quantified via real-time PCR. Alone and in combination with IGF1, FGF9 significantly increased CCND1 mRNA expression in both GC and TC. Western blotting revealed that CCND1 protein levels were increased by FGF9 in TC after 6 h and 12 h of treatment, but CDK4 protein was not affected. A mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway inhibitor, U0126, significantly reduced FGF9-induced CCND1 mRNA expression to basal levels. For the first time we show that CCND1 mRNA expression is increased by FGF9 in bovine TC and GC, and that FGF9 likely uses the MAPK pathway to induce CCND1 mRNA production in bovine TC.

The expression profiles of fibroblast growth factor 9 and its receptors in developing mice testes

An expressional lack of fibroblast growth factor 9 (FGF9) would cause male-to-female sex reversal in the mouse, implying the essential role of FGF9 in testicular organogenesis and maturation. However, the temporal expression of FGF9 and its receptors during testicular development remains elusive. In this study, immunohistochemistry was used to identify the localization of FGF9 and its receptors at different embryonic and postnatal stages in mice testes. Results showed that FGF9 continuously expressed in the testis during development. FGF9 had highest expression in the interstitial region at 17-18 d post coitum (dpc) and in the spermatocytes, spermatids and Leydig cell on postnatal days (pnd) 35-65. Regarding receptor expression, FGFR1 and FGFR4 were evenly expressed in the whole testis during the embryonic and postnatal stages. However, FGFR2 and FGFR3 were widely expressed during the embryonic testis development with higher FGFR2 expression in seminiferous tubules at 16-18 dpc and higher FGFR3 expression in interstitial region at 17-18 dpc. In postnatal stage, FGFR2 extensively expressed with higher expression at spermatids and Leydig cells on 35-65 pnd and FGFR3 widely expressed in the whole testis. Taken together, these results strongly suggest that FGF9 is correlated with the temporal expression profiles of FGFR2 and FGFR3 and possibly associated with testis development.

Molecular regulation of steroidogenesis in endocrine Leydig cells

Steroid hormones regulate essential physiological processes and inadequate levels are associated with various pathological conditions. Consequently, the process of steroid hormone biosynthesis is finely regulated. In the testis, the main steroidogenic cells are the Leydig cells. There are two distinct populations of Leydig cells that arise during development: fetal and adult Leydig cells. Fetal Leydig cells are responsible for masculinizing the male urogenital tract and inducing testis descent. These cells atrophy shortly after birth and do not contribute to the adult Leydig cell population. Adult Leydig cells derive from undifferentiated precursors present after birth and become fully steroidogenic at puberty. The differentiation of both Leydig cell populations is controlled by locally produced paracrine factors and by endocrine hormones. In fully differentially and steroidogenically active Leydig cells, androgen production and hormone-responsiveness involve various signaling pathways and downstream transcription factors. This review article focuses on recent developments regarding the origin and function of Leydig cells, the regulation of their differentiation by signaling molecules, hormones, and structural changes, the signaling pathways, kinases, and transcription factors involved in their differentiation and in mediating LH-responsiveness, as well as the fine-tuning mechanisms that ensure adequate production steroid hormones.

FGF9 from cancer-associated fibroblasts is a possible mediator of invasion and anti-apoptosis of gastric cancer cells

Background

Cancer-associated fibroblasts (CAFs), which reside around tumor cells, are suggested to play a pivotal role in tumor progression. Here we performed microarray analyses to compare gene expression profiles between CAFs and non-cancerous gastric fibroblasts (NGFs) from a patient with gastric cancer and found that fibroblast growth factor 9 (FGF9) was a novel growth factor overexpressed in CAFs. We then examined the biological effects of FGF9 during progression of gastric cancer.

Methods

Expression of FGF9 in CAFs and NGFs, and their secreted products, were examined by Western blotting. The effects of FGF9 on AGS and MKN28 gastric cancer cells in terms of proliferation, invasion and anti-apoptosis were assessed by WST-1 assay, invasion chamber assay and FACS, respectively. Furthermore, the intracellular signaling by which FGF9 exerts its biological roles was examined in vitro.

Results

FGF9 was strongly expressed in CAFs in comparison with NGFs, being compatible with microarray data indicating that FGF9 was a novel growth factor overexpressed in CAFs. Treatment with FGF9 promoted invasion and anti-apoptosis through activation of the ERK and Akt signaling pathways in AGS and MKN28 cells, whereas these effects were attenuated by treatment with anti-FGF9 neutralizing antibody. In addition, FGF9 treatment significantly enhanced the expression of matrix metalloproteinase 7 (MMP7) in both cell lines.

Conclusions

FGF9 is a possible mediator secreted by CAFs that promotes the anti-apoptosis and invasive capability of gastric cancer cells.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1353-3) contains supplementary material, which is available to authorized users.