Effects of inhibin-related peptides and oestradiol on androstenedione and progesterone secretion by bovine theca cells in vitro

1995 ◽  
Vol 145 (3) ◽  
pp. 491-500 ◽  
Author(s):  
J H M Wrathall ◽  
P G Knight
Keyword(s):  
Granulosa Cell ◽  
Thecal Cell ◽  
Theca Cells ◽  
Progesterone Secretion ◽  
Pretreatment Period ◽  
Direct Contrast ◽  
Primary Monolayer ◽  
Dose Dependent

Abstract Primary monolayer cultures of bovine theca cells isolated from pooled ovarian follicles (3–10 mm diameter) were used to examine the effects of various granulosa cell-derived substances on basal and luteinizing hormone (LH)-induced androgen and progesterone secretion. After an overnight pretreatment period, cells were incubated with a range of treatments including LH, oestradiol-17β, inhibin, activin and follistatin. Media were collected after 48 h and assessment of androstenedione and progesterone secretion made by radioimmunoassay. Addition of LH (5–50 ng/ml) to the cells resulted in a dose-dependent stimulation of both androstenedione (2·5-to 3-fold rise; P<0·01) and progesterone (∼ 1·6-fold rise; P<0·001) production. Secretion of androstenedione was also raised (up to 5-fold; P<0·001) by addition of oestradiol-17β (0·3–300 ng/ml), whilst levels of the androgen in the presence of both LH (20 ng/ml) and oestradiol (300 ng/ml) were up to 12-fold higher (P<0·001) than control values. In contrast, oestradiol treatment inhibited by up to 50% both basal (P<0·001) and LH-stimulated (P<0·001) secretion of progesterone. Exposure of cells to purified bovine inhibin (5–125 ng/ml) consistently raised androstenedione secretion by up to 42% over basal levels (P<0·001). Inhibin also enhanced both LH-stimulated (∼20%; P<0·001) and oestradiol-stimulated (∼20%; P<0·05) secretion of androstenedione. In direct contrast, treatment of theca cells with human recombinant activin-A (1–50 ng/ml) inhibited both LH-stimulated (∼50%; P<0·001) and oestradiol-stimulated (∼30%; P<0·005) androstenedione secretion. Activin also reversed the positive effect of inhibin on basal (P<0·01), LH-stimulated (P<0·001) and oestradiol-stimulated (P<0·001) androstenedione secretion, though activin alone did not affect basal steroid output. Simultaneous addition of human recombinant follistatin reversed the inhibitory effects of activin on LH- and oestradiol-induced androstenedione secretion but did not modify the effects of inhibin. Follistatin alone did not alter either basal or LH-stimulated androstenedione output. Neither basal nor LH-stimulated secretion of progesterone were consistently affected by inhibin, activin or follistatin. As well as confirming the stimulatory effects of both LH and oestradiol on bovine thecal cell androgen production, these observations are indicative of opposing intrafollicular paracrine roles for granulosa cell-derived inhibin and activin in modulating thecal cell responses to gonadotrophins and steroids in the bovine ovary. Though inhibin and oestradiol had qualitatively similar effects in promoting thecal androgen secretion, the magnitude of the response to oestradiol was much greater. The results also support an intrafollicular role of follistatin as a binding protein capable of neutralizing the effect of activin, but not inhibin, on thecal androgen production. Journal of Endocrinology (1995) 145, 491–500

scholarly journals The role of IGFs in the regulation of ovarian follicular growth in the brushtail possum (Trichosurus vulpecula)

Reproduction ◽  
2010 ◽  
Vol 140 (2) ◽  
pp. 295-303 ◽  
Author(s):  
Jennifer L Juengel ◽  
Lisa J Haydon ◽  
Brigitta Mester ◽  
Brian P Thomson ◽  
Michael Beaumont ◽  
...  
Keyword(s):  
Granulosa Cell ◽  
Granulosa Cells ◽  
Cell Function ◽  
Antral Follicle ◽  
Brushtail Possum ◽  
Follicular Growth ◽  
Theca Cells ◽  
Ovarian Follicular Growth

IGFs are known to be key regulators of ovarian follicular growth in eutherian mammals, but little is known regarding their role in marsupials. To better understand the potential role of IGFs in the regulation of follicular growth in marsupials, expression of mRNAs encoding IGF1, IGF2, IGF1R, IGF-binding protein 2 (IGFBP2), IGFBP4 and IGFBP5 was localized by in situ hybridization in developing ovarian follicles of the brushtail possum. In addition, the effects of IGF1 and IGF2 on granulosa cell function were tested in vitro. Both granulosa and theca cells synthesize IGF mRNAs, with the theca expressing IGF1 mRNA and granulosa cell expressing IGF2 mRNA. Oocytes and granulosa cells express IGF1R. Granulosa and theca cells expressed IGFBP mRNAs, although the pattern of expression differed between the BPs. IGFBP5 mRNA was differentially expressed as the follicles developed with granulosa cells of antral follicles no longer expressing IGFBP5 mRNA, suggesting an increased IGF bioavailability in the antral follicle. The IGFBP protease, PAPPA mRNA, was also expressed in granulosa cells of growing follicles. Both IGF1 and IGF2 stimulated thymidine incorporation but had no effect on progesterone production. Thus, IGF may be an important regulator of ovarian follicular development in marsupials as has been shown in eutherian mammals.

scholarly journals Lumican Inhibits Osteoclastogenesis and Bone Resorption by Suppressing Akt Activity

2021 ◽  
Vol 22 (9) ◽  
pp. 4717
Author(s):  
Jin-Young Lee ◽  
Da-Ae Kim ◽  
Eun-Young Kim ◽  
Eun-Ju Chang ◽  
So-Jeong Park ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Formation ◽  
Map Kinases ◽  
Osteoclast Differentiation ◽  
Dependent Manner ◽  
Dual Action ◽  
Dose Dependent ◽  
Resorptive Activity

Lumican, a ubiquitously expressed small leucine-rich proteoglycan, has been utilized in diverse biological functions. Recent experiments demonstrated that lumican stimulates preosteoblast viability and differentiation, leading to bone formation. To further understand the role of lumican in bone metabolism, we investigated its effects on osteoclast biology. Lumican inhibited both osteoclast differentiation and in vitro bone resorption in a dose-dependent manner. Consistent with this, lumican markedly decreased the expression of osteoclastogenesis markers. Moreover, the migration and fusion of preosteoclasts and the resorptive activity per osteoclast were significantly reduced in the presence of lumican, indicating that this protein affects most stages of osteoclastogenesis. Among RANKL-dependent pathways, lumican inhibited Akt but not MAP kinases such as JNK, p38, and ERK. Importantly, co-treatment with an Akt activator almost completely reversed the effect of lumican on osteoclast differentiation. Taken together, our findings revealed that lumican inhibits osteoclastogenesis by suppressing Akt activity. Thus, lumican plays an osteoprotective role by simultaneously increasing bone formation and decreasing bone resorption, suggesting that it represents a dual-action therapeutic target for osteoporosis.

scholarly journals Inhibition of Prostate Cancer DU-145 Cells Proliferation by Anthopleura anjunae Oligopeptide (YVPGP) via PI3K/AKT/mTOR Signaling Pathway

Marine Drugs ◽  
2018 ◽  
Vol 16 (9) ◽  
pp. 325 ◽  
Author(s):  
Xiaojuan Li ◽  
Yunping Tang ◽  
Fangmiao Yu ◽  
Yu Sun ◽  
Fangfang Huang ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Signaling Pathway ◽  
Caspase 3 ◽  
Mtor Signaling ◽  
Mtor Signaling Pathway ◽  
Nude Mouse Model ◽  
Dose Dependent

We investigated the antitumor mechanism of Anthopleura anjunae oligopeptide (AAP-H, YVPGP) in prostate cancer DU-145 cells in vitro and in vivo. Results indicated that AAP-H was nontoxic and exhibited antitumor activities. Cell cycle analysis indicated that AAP-H may arrest DU-145 cells in the S phase. The role of the phosphatidylinositol 3-kinase/protein kinase B/mammalian rapamycin target protein (PI3K/AKT/mTOR) signaling pathway in the antitumor mechanism of APP-H was investigated. Results showed that AAP-H treatment led to dose-dependent reduction in the levels of p-AKT (Ser473), p-PI3K (p85), and p-mTOR (Ser2448), whereas t-AKT and t-PI3K levels remained unaltered compared to the untreated DU-145 cells. Inhibition of PI3K/AKT/mTOR signaling pathway in the DU-145 cells by employing inhibitor LY294002 (10 μM) or rapamycin (20 nM) effectively attenuated AAP-H-induced phosphorylation of AKT and mTOR. At the same time, inhibitor addition further elevated AAP-H-induced cleaved-caspase-3 levels. Furthermore, the effect of AAP-H on tumor growth and the role of the PI3K/AKT/mTOR signaling pathway in nude mouse model were also investigated. Immunohistochemical analysis showed that activated AKT, PI3K, and mTOR levels were reduced in DU-145 xenografts. Western blotting showed that AAP-H treatment resulted in dose-dependent reduction in p-AKT (Ser473), p-PI3K (p85), and p-mTOR (Ser2448) levels, whereas t-AKT and t-PI3K levels remained unaltered. Similarly, Bcl-xL levels decreased, whereas that of Bax increased after AAP-H treatment. AAP-H also increased initiator (caspase 8 and 9) and executor caspase (caspase 3 and 7) levels. Therefore, the antitumor mechanism of APP-H on DU-145 cells may involve regulation of the PI3K/AKT/mTOR signaling pathway, which eventually promotes apoptosis via mitochondrial and death receptor pathways. Thus, the hydrophobic oligopeptide (YVPGP) can be developed as an adjuvant for the prevention or treatment of prostate cancer in the future.

scholarly journals Silymarin: Friend or Foe of UV Exposed Keratinocytes?

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1652 ◽  
Author(s):  
Fidrus ◽  
Ujhelyi ◽  
Fehér ◽  
Hegedűs ◽  
Janka ◽  
...  
Keyword(s):  
Pyrimidine Dimer ◽  
Ros Generation ◽  
Keratinocyte Cell ◽  
Pre Treatment ◽  
Different Origins ◽  
Apoptotic Effects ◽  
Dose Dependent ◽  
Higher Doses

The application of natural plant extracts in UV-protection is popular and intensively studied. Silymarin (from Silibum marianum), a naturally occurring polyphenol, has recently received attention due to its antioxidant, anti-inflammatory and anti-apoptotic effects. However, its role in the UV-mediated keratinocyte cell response is still controversial. In this study, we investigated the effects of Silibum marianum extracts with different origins and formulations on UVA-exposed HaCaT keratinocytes in vitro. Our results show, that silymarin treatment caused an inverse dose-dependent photosensitivity relationship (at higher doses, a decrease in cell viability and ROS production) after UVA exposure. The attenuation of the UVA-induced ROS generation after silymarin treatment was also observed. Moreover, silymarin pre-treatment increased the cyclobutane pyrimidine dimer photolesions in keratinocytes after UVA exposure. These results indicated the dual role of silymarin in UVA-exposed keratinocytes. It scavenges ROS but still induces phototoxicity. Based on our results dermatological applications of silymarin and related compounds should be considered very carefully.

cAMP-stimulated rise of [Ca2+]i in rabbit connecting tubules: role of peritubular Ca

1990 ◽  
Vol 258 (3) ◽  
pp. F751-F755 ◽  
Author(s):  
J. E. Bourdeau ◽  
B. K. Eby
Keyword(s):  
Parathyroid Hormone ◽  
Ethylene Glycol ◽  
Cell Activation ◽  
Proximal Tubules ◽  
Tetraacetic Acid ◽  
Luminal Membrane ◽  
Dose Dependent Fashion ◽  
Dose Dependent

Parathyroid hormone (PTH) increases cytosolic free Ca concentration ([ Ca2+]i) by mechanisms that depend on extracellular Ca in both cultured renal proximal tubules and isolated rabbit connecting tubules (CNTs). In CNTs 8-bromoadenosine 3',5'-cyclic monophosphate (8-BrcAMP) mimics this action, implicating cAMP as a second messenger, and part of the rise, due to increased luminal membrane Ca entry, is likely related to Ca absorption. In cultured proximal tubules the rise in [Ca2+]i, presumably mediated by increased Ca entry across the basolateral plasmalemma, activates gluconeogenesis and shortens microvilli. In the present study we examined cAMP-mediated Ca entry across the basolateral membranes of CNT cells, an effect potentially related to cell activation. Single CNTs were dissected from rabbit kidneys and loaded with fura-2. [Ca2+]i was measured by dual-wavelength excitation during perfusion of isolated segments in vitro. With 1.8 or 2.0 mM Ca in the lumen and the bath, suffusate 8-BrcAMP increased [Ca2+]i within minutes in a dose-dependent fashion. The increase persisted as long as 8-BrcAMP was present and reversed on its withdrawal. With 0.1 microM Ca in the lumen and the bath, 8-BrcAMP, but not ionomycin, failed to increase [Ca2+]i, implying that extracellular Ca is the major source. In tubules perfused with 2 mM ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid to eliminate luminal Ca, but suffused with 1.8 or 2.0 mM Ca, 8-BrcAMP increased [Ca2+]i (though less so than with Ca in the lumen), implying Ca entry across basolateral cell membranes. This rise in [Ca2+]i was attenuated markedly by the presence of 50 microM LaCl3 in the bath.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Leptin Upregulates the Expression of β3-Integrin, MMP9, HB-EGF, and IL-1β in Primary Porcine Endometrium Epithelial Cells In Vitro

2020 ◽  
Vol 17 (18) ◽  
pp. 6508
Author(s):  
Hongfang Wang ◽  
Jinlian Fu ◽  
Aiguo Wang
Keyword(s):  
Signaling Pathways ◽  
Embryo Implantation ◽  
Mapk Signaling ◽  
Dependent Manner ◽  
Reproductive Disorders ◽  
Β3 Integrin ◽  
Epithelium Cells ◽  
Dose Dependent

Obesity has become a global health problem. Research suggests that leptin, a hormone that responds to fat deposition, may be involved in mammalian reproduction; however, its precise role in embryo implantation is poorly understood. Here, primary porcine endometrium epithelium cells (PEECs) were cultured in vitro and used to evaluate the regulatory role of different leptin levels on β3-integrin, MMP9, HB-EGF, and IL-1β, which are, respectively, involved in four critical steps of embryo implantation. Results showed that only 0.01 nM leptin significantly improved β3-integrin mRNA expression (p < 0.05). MMP9 and HB-EGF mRNA expressions were upregulated by 0.10–10.00 nM leptin (p < 0.05). The IL-1β expression level was only increased by 10.00 nM leptin (p < 0.05). β3-integrin, MMP9, HB-EGF, and IL-1β mRNA and protein have a similar fluctuant response to increased leptin. Leptin’s influence on β3-integrin, MMP9, HB-EGF, and IL-1β disappeared when the JAK2, PI(3)K, or MAPK signaling pathways were blocked, respectively. In conclusion, leptin affected porcine implantation by regulating the expression of β3-integrin, MMP9, HB-EGF, and IL-1β in a dose-dependent manner. The signaling pathways of JAK2, PI(3)K, and MAPK may participate in this regulatory process. These findings will contribute to further understanding the mechanisms of reproductive disorders in obesity.

Safflower Yellow Prevents Pulmonary Metastasis of Breast Cancer by Inhibiting Tumor Cell Invadopodia

2016 ◽  
Vol 44 (07) ◽  
pp. 1491-1506 ◽  
Author(s):  
Huiying Fu ◽  
Renjie Wu ◽  
Yuanyuan Li ◽  
Lizong Zhang ◽  
Xiaofang Tang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Pulmonary Metastasis ◽  
Breast Cancer Cells ◽  
Dependent Cell ◽  
Response Profiles ◽  
Dose Dependent

Carthamus tinctorius L. is a traditional Chinese medicine that activates blood circulation and dissipates blood stasis, and has been extensively used as antitumor treatment in a clinical setting in single or in compound preparation form. However, empirical evidence and a better understanding of the possible mechanisms involved are still required. Here, we investigated the role of safflower yellow (SY), the active ingredient of C. tinctorius, in the pulmonary metastasis of breast cancer, and the underlying mechanism of action. EGF-meditated time- and dose-dependent cell response profiles were applied to screen for the activity of SY in vitro, while orthotopic lung metastasis and intravenous injection were used to evaluate the antimetastatic role of SY in vivo. SY could dose-dependently inhibit EGF-mediated time- and dose-dependent cell response profiles by inhibiting cytoskeletal rearrangement. We also found that SY significantly inhibited the migration of breast cancer cells in vitro and pulmonary metastasis of breast cancer cells in vivo. Consistent with these phenotypes, formation of invadopodia and the expression of MMP-9 and p-Src proteins were decreased after EGF stimulation in MBA-MD-231 cells treat with SY, as well as in lung metastatic foci. Additionally, circulating tumor cells retained in lung capillaries were also reduced. These results suggest that the antimetastatic effect of SY is due to its inhibition of invadopodia formation, which occurs mainly through Src-dependent cytoskeleton rearrangement. We suggest that SY should be considered as a potential novel therapeutic agent for the treatment of breast cancer.

scholarly journals Opposing Roles of Leptin and Ghrelin in the Equine Corpus Luteum Regulation: AnIn VitroStudy

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
António Galvão ◽  
Angela Tramontano ◽  
Maria Rosa Rebordão ◽  
Ana Amaral ◽  
Pedro Pinto Bravo ◽  
...  
Keyword(s):  
Corpus Luteum ◽  
Reproductive Function ◽  
Secretory Activity ◽  
Dependent Manner ◽  
Angiogenic Activity ◽  
Metabolic Hormones ◽  
Protein Levels ◽  
Dose Dependent

Metabolic hormones have been associated with reproductive function modulation. Thus, the aim of this study was: (i) to characterize the immunolocalization, mRNA and protein levels of leptin (LEP), Ghrelin (GHR) and respective receptors LEPR and Ghr-R1A, throughout luteal phase; and (ii) to evaluate the role of LEP and GHR on progesterone (P4), prostaglandin (PG) E2and PGF2α, nitric oxide (nitrite), tumor necrosis factor-α(TNF); macrophage migration inhibitory factor (MIF) secretion, and on angiogenic activity (BAEC proliferation), in equine corpus luteum (CL) from early and mid-luteal stages. LEPR expression was decreased in late CL, while GHR/Ghr-R1A system was increased in the same stage. Regarding secretory activity, GHR decreased P4in early CL, but increased PGF2α, nitrite and TNF in mid CL. Conversely, LEP increased P4, PGE2, angiogenic activity, MIF, TNF and nitrite during early CL, in a dose-dependent manner. Thein vitroeffect of LEP on secretory activity was reverted by GHR, when both factors acted together. The present results evidence the presence of LEP and GHR systems in the equine CL. Moreover, we suggest that LEP and GHR play opposing roles in equine CL regulation, with LEP supporting luteal establishment and GHR promoting luteal regression. Finally, a dose-dependent luteotrophic effect of LEP was demonstrated.

scholarly journals SMAD1/5 Signaling in the Early Equine Placenta Regulates Trophoblast Differentiation and Chorionic Gonadotropin Secretion

Endocrinology ◽  
2014 ◽  
Vol 155 (8) ◽  
pp. 3054-3064 ◽  
Author(s):  
Victoria Cabrera-Sharp ◽  
Jordan E. Read ◽  
Stephanie Richardson ◽  
Alycia A. Kowalski ◽  
Douglas F. Antczak ◽  
...  
Keyword(s):  
Chorionic Gonadotropin ◽  
Trophoblast Cells ◽  
Rt Pcr ◽  
Trophoblast Differentiation ◽  
Gonadotropin Secretion ◽  
Morphogenetic Protein ◽  
Dose Dependent

TGFβ superfamily proteins, acting via SMAD (Sma- and Mad-related protein)2/3 pathways, regulate placental function; however, the role of SMAD1/5/8 pathway in the placenta is unknown. This study investigated the functional role of bone morphogenetic protein (BMP)4 signaling through SMAD1/5 in terminal differentiation of primary chorionic gonadotropin (CG)-secreting trophoblast. Primary equine trophoblast cells or placental tissues were isolated from day 27–34 equine conceptuses. Detected by microarray, RT-PCR, and quantitative RT-PCR, equine chorionic girdle trophoblast showed increased gene expression of receptors that bind BMP4. BMP4 mRNA expression was 20- to 60-fold higher in placental tissues adjacent to the chorionic girdle compared with chorionic girdle itself, suggesting BMP4 acts primarily in a paracrine manner on the chorionic girdle. Stimulation of chorionic girdle-trophoblast cells with BMP4 resulted in a dose-dependent and developmental stage-dependent increase in total number and proportion of terminally differentiated binucleate cells. Furthermore, BMP4 treatment induced non-CG-secreting day 31 chorionic girdle trophoblast cells to secrete CG, confirming a specific functional response to BMP4 stimulation. Inhibition of SMAD2/3 signaling combined with BMP4 treatment further enhanced differentiation of trophoblast cells. Phospho-SMAD1/5, but not phospho-SMAD2, expression as determined by Western blotting was tightly regulated during chorionic girdle trophoblast differentiation in vivo, with peak expression of phospho-SMAD1/5 in vivo noted at day 31 corresponding to maximal differentiation response of trophoblast in vitro. Collectively, these experiments demonstrate the involvement of BMP4-dependent pathways in the regulation of equine trophoblast differentiation in vivo and primary trophoblast differentiation in vitro via activation of SMAD1/5 pathway, a previously unreported mechanism of TGFβ signaling in the mammalian placenta.

scholarly journals SMAD7 antagonizes key TGFβ superfamily signaling in mouse granulosa cells in vitro

Reproduction ◽  
2013 ◽  
Vol 146 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Yang Gao ◽  
Haixia Wen ◽  
Chao Wang ◽  
Qinglei Li
Keyword(s):  
Granulosa Cell ◽  
Granulosa Cells ◽  
Transforming Growth Factor ◽  
Negative Regulator ◽  
Fine Tuning ◽  
Female Reproduction ◽  
Tgfβ Signaling ◽  
Tgfβ Superfamily

Transforming growth factor β (TGFβ) superfamily signaling is essential for female reproduction. Dysregulation of the TGFβ signaling pathway can cause reproductive diseases. SMA and MAD (mothers against decapentaplegic) (SMAD) proteins are downstream signaling transducers of the TGFβ superfamily. SMAD7 is an inhibitory SMAD that regulates TGFβ signalingin vitro. However, the function of SMAD7 in the ovary remains poorly defined. To determine the signaling preference and potential role of SMAD7 in the ovary, we herein examined the expression, regulation, and function of SMAD7 in mouse granulosa cells. We showed that SMAD7 was expressed in granulosa cells and subject to regulation by intraovarian growth factors from the TGFβ superfamily. TGFB1 (TGFβ1), bone morphogenetic protein 4, and oocyte-derived growth differentiation factor 9 (GDF9) were capable of inducingSmad7expression, suggesting a modulatory role of SMAD7 in a negative feedback loop. Using a small interfering RNA approach, we further demonstrated that SMAD7 was a negative regulator of TGFB1. Moreover, we revealed a link between SMAD7 and GDF9-mediated oocyte paracrine signaling, an essential component of oocyte–granulosa cell communication and folliculogenesis. Collectively, our results suggest that SMAD7 may function during follicular development via preferentially antagonizing and/or fine-tuning essential TGFβ superfamily signaling, which is involved in the regulation of oocyte–somatic cell interaction and granulosa cell function.

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