Roles of the activin regulatory system in fish reproduction

2000 ◽  
Vol 78 (12) ◽  
pp. 1077-1085 ◽  
Author(s):  
Wei Ge
Keyword(s):  
Oocyte Maturation ◽  
Biological Activities ◽  
Ovarian Follicle ◽  
Mrna Level ◽  
Type I ◽  
Fish Reproduction ◽  
Potent Effect ◽  
Α Subunit ◽  
Final Oocyte Maturation

Activin (βAβA, βAβB, and βBβb) is a dimeric growth factor with diverse biological activities in vertebrate reproduction. Activin exerts its actions by binding to its specific type II and type I receptors. The activity of activin is regulated by follistatin, its binding protein, and the antagonists inhibin and antivin. All major components of the activin-inhibin-follistatin system have been identified in fish except the α subunit of inhibin. Using goldfish as a model, we have demonstrated that activin is expressed in the pituitary and the recombinant goldfish activin B has novel inverse effects on the expression of GTH β subunits. Activin increases the mRNA level of GTH-Iβ while significantly suppressing the expression of GTH-IIβ. We have also demonstrated the expression of activin and its receptors in the goldfish and zebrafish ovary. Using an in vitro ovarian follicle incubation as the system, we have investigated the involvement of the activin system in the process of final oocyte maturation. Our evidence clearly indicates that activin has potent effect of promoting final oocyte maturation, and that it may play a role in mediating the stimulatory effect of pituitary gonadotropin in the event of oocyte maturation. Key words: activin, inhibin, follistatin, fish, reproduction.

scholarly journals Involvement of Cyclic Adenosine 3′,5′-Monophosphate in the Differential Regulation of Activin βA and βB Expression by Gonadotropin in the Zebrafish Ovarian Follicle Cells

Endocrinology ◽  
2003 ◽  
Vol 144 (2) ◽  
pp. 491-499 ◽  
Author(s):  
Yajun Wang ◽  
Wei Ge
Keyword(s):  
Oocyte Maturation ◽  
Ovarian Follicle ◽  
Mrna Level ◽  
Specific Inhibitor ◽  
Inhibitory Effect ◽  
Differential Regulation ◽  
Follicle Cells ◽  
Intracellular Camp ◽  
Dependent Manner

Activin is a dimeric protein consisting of two similar but distinct β-subunits, βA and βB. In our previous studies, both activin A (βAβA) and activin B (βBβB) have been demonstrated to stimulate oocyte maturation and promote oocyte maturational competence in the zebrafish. Follistatin, a specific activin-binding protein, can block both activin- and gonadotropin-induced final oocyte maturation in vitro, suggesting that activin is likely a downstream mediator of gonadotropin actions in the zebrafish ovary. In the present study, a full-length cDNA encoding zebrafish ovarian activin βA was cloned and sequenced. The precursor of zebrafish activin βA consists of 395 amino acids and its mature region exhibits about 78% homology with that of mammals. Using an in vitro primary culture of the ovarian follicle cells and semiquantitative RT-PCR assays, we examined the regulation of activin βA and βB expression by human chorionic gonadotropin (hCG) and its intracellular signal transduction mechanisms. hCG (15 IU/ml) increased the mRNA level of activin βA-subunit; however, it significantly down-regulated the steady-state expression level of activin βB in a time- and dose-dependent manner. The differential regulation of the two β-subunits by hCG could be mimicked by 3-isobutyl-1-methylxanthine, forskolin, and dibutyryl-cAMP, suggesting involvement of the intracellular cAMP pathway. Interestingly, H89 (a specific inhibitor of protein kinase A, PKA) could effectively block hCG- and forskolin-stimulated activin βA expression at 10 μm, but it was unable to reverse the inhibitory effects of hCG and forskolin on βB expression. This suggests that the hCG-stimulated activin βA expression is dependent on the activation of the cAMP-PKA pathway, whereas the inhibitory effect of hCG on activin βB expression is likely mediated by PKA-independent pathway(s).

Transmembrane prolyl 4-hydroxylase is a fourth prolyl 4-hydroxylase regulating EPO production and erythropoiesis

Blood ◽  
2012 ◽  
Vol 120 (16) ◽  
pp. 3336-3344 ◽  
Author(s):  
Anu Laitala ◽  
Ellinoora Aro ◽  
Gail Walkinshaw ◽  
Joni M. Mäki ◽  
Maarit Rossi ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Mrna Level ◽  
Hypoxia Inducible Factor ◽  
Mrna Levels ◽  
Wild Type ◽  
Α Subunit ◽  
Hepcidin Expression ◽  
In The Wild ◽  
Hepcidin Mrna

AbstractAn endoplasmic reticulum transmembrane prolyl 4-hydroxylase (P4H-TM) is able to hydroxylate the α subunit of the hypoxia-inducible factor (HIF) in vitro and in cultured cells, but nothing is known about its roles in mammalian erythropoiesis. We studied such roles here by administering a HIF-P4H inhibitor, FG-4497, to P4h-tm−/− mice. This caused larger increases in serum Epo concentration and kidney but not liver Hif-1α and Hif-2α protein and Epo mRNA levels than in wild-type mice, while the liver Hepcidin mRNA level was lower in the P4h-tm−/− mice than in the wild-type. Similar, but not identical, differences were also seen between FG-4497–treated Hif-p4h-2 hypomorphic (Hif-p4h-2gt/gt) and Hif-p4h-3−/− mice versus wild-type mice. FG-4497 administration increased hemoglobin and hematocrit values similarly in the P4h-tm−/− and wild-type mice, but caused higher increases in both values in the Hif-p4h-2gt/gt mice and in hematocrit value in the Hif-p4h-3−/− mice than in the wild-type. Hif-p4h-2gt/gt/P4h-tm−/− double gene-modified mice nevertheless had increased hemoglobin and hematocrit values without any FG-4497 administration, although no such abnormalities were seen in the Hif-p4h-2gt/gt or P4h-tm−/− mice. Our data thus indicate that P4H-TM plays a role in the regulation of EPO production, hepcidin expression, and erythropoiesis.

mRNA levels for α-subunit of prolyl 4-hydroxylase and fibrillar collagens in immobilized rat skeletal muscle

1999 ◽  
Vol 87 (1) ◽  
pp. 90-96 ◽  
Author(s):  
Xiao-Yan Han ◽  
Wei Wang ◽  
Raili Myllylä ◽  
Paula Virtanen ◽  
Jarmo Karpakka ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Tibialis Anterior ◽  
Collagen Synthesis ◽  
Plantar Flexion ◽  
Mrna Level ◽  
Type I ◽  
Mrna Levels ◽  
Rat Skeletal Muscle ◽  
Α Subunit ◽  
Fibrillar Collagens

There is evidence that immobilization causes a decrease in total collagen synthesis in skeletal muscle within a few days. In this study, early immobilization effects on the expression of prolyl 4-hydroxylase (PH) and the main fibrillar collagens at mRNA and protein levels were investigated in rat skeletal muscle. The right hindlimb was immobilized in full plantar flexion for 1, 3, and 7 days. Steady-state mRNAs for α- and β-subunits of PH and type I and III procollagen, PH activity, and collagen content were measured in gastrocnemius and plantaris muscles. Type I and III procollagen mRNAs were also measured in soleus and tibialis anterior muscles. The mRNA level for the PH α-subunit decreased by 49 and 55% ( P < 0.01) in gastrocnemius muscle and by 41 and 39% ( P < 0.05) in plantaris muscle after immobilization for 1 and 3 days, respectively. PH activity was decreased ( P < 0.05–0.01) in both muscles at days 3 and 7. The mRNA levels for type I and III procollagen were decreased by 26–56% ( P < 0.05–0.001) in soleus, tibialis anterior, and plantaris muscles at day 3. The present results thus suggest that pretranslational downregulation plays a key role in fibrillar collagen synthesis in the early phase of immobilization-induced muscle atrophy.

scholarly journals Phytochemical Characterization and Evaluation of Biological Activities of Egyptian Carob Pods (Ceratonia siliqua L.) Aqueous Extract: In Vitro Study

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2626
Author(s):  
Wael Sobhy Darwish ◽  
Abada El Sayed Khadr ◽  
Maher Abd El Naby Kamel ◽  
Mabrouk A. Abd Eldaim ◽  
Ibrahim El Tantawy El Sayed ◽  
...  
Keyword(s):  
Aqueous Extract ◽  
Biological Activities ◽  
Radical Scavenging ◽  
Antimicrobial Activities ◽  
Biologically Active ◽  
Phytochemical Analysis ◽  
Type I ◽  
Hypotonic Solution ◽  
Ceratonia Siliqua

Ceratonia siliqua (Carob) is an evergreen Mediterranean tree, and carob pods are potentially nutritive and have medicinal value. The present study was carried out to estimate the possible biological activities of phytochemical-characterized carob pod aqueous extract (CPAE). The phytochemical contents of CPAE were determined by using colorimetric methods and HPLC. In addition, the free radical scavenging properties and anti-diabetic, anti-hemolytic, and antimicrobial activities were estimated by using standardized in vitro protocols. The phytochemical analysis revealed that CPAE was rich in polyphenols, flavonoids, and alkaloids, where it contained a significant amount of gallic acid, catechin, and protocatechuic acid. Furthermore, CPAE exhibited strong antioxidant activity where it prevented the formation of 2, 2-Diphenyl-1-picryl hydrazyl, hydroxyl, and nitric oxide free radicals. Additionally, it had a potent inhibitory effect against digestive enzymes (amylase, maltase, sucrase, and lactase). Moreover, CPAE exhibited anti-Staph aureus, anti-Escherichia coli, anti-Candida albicans, and anti-herpes simplex type I virus (HSV-I). Finally, CPAE protected the erythrocyte membrane from hypotonic solution-induced hemolysis. Altogether, CPAE could be regarded as an interesting source of biologically active antioxidant, anti-diabetic, and antimicrobial preparation for a potential application in pharmaceutical and food supplement fields.

scholarly journals SSP3 Is a Novel Plasmodium yoelii Sporozoite Surface Protein with a Role in Gliding Motility

2014 ◽  
Vol 82 (11) ◽  
pp. 4643-4653 ◽  
Author(s):  
Anke Harupa ◽  
Brandon K. Sack ◽  
Viswanathan Lakshmanan ◽  
Nadia Arang ◽  
Alyse N. Douglass ◽  
...  
Keyword(s):  
Salivary Glands ◽  
Biological Activities ◽  
Surface Protein ◽  
Plasmodium Yoelii ◽  
Gliding Motility ◽  
Surface Proteins ◽  
Type I ◽  
Content Type ◽  
Mosquito Midgut

ABSTRACTPlasmodiumsporozoites develop within oocysts in the mosquito midgut wall and then migrate to the salivary glands. After transmission, they embark on a complex journey to the mammalian liver, where they infect hepatocytes. Proteins on the sporozoite surface likely mediate multiple steps of this journey, yet only a few sporozoite surface proteins have been described. Here, we characterize a novel, conserved sporozoite surface protein (SSP3) in the rodent malaria parasitePlasmodium yoelii. SSP3 is a putative type I transmembrane protein unique toPlasmodium. By using epitope tagging and SSP3-specific antibodies in conjunction with immunofluorescence microscopy, we showed that SSP3 is expressed in mosquito midgut oocyst sporozoites, exhibiting an intracellular localization. In sporozoites derived from the mosquito salivary glands, however, SSP3 localized predominantly to the sporozoite surface as determined by immunoelectron microscopy. However, the ectodomain of SSP3 appeared to be inaccessible to antibodies in nonpermeabilized salivary gland sporozoites. Antibody-induced shedding of the major surface protein circumsporozoite protein (CSP) exposed the SSP3 ectodomain to antibodies in some sporozoites. Targeted deletion ofSSP3adversely affectedin vitrosporozoite gliding motility, which, surprisingly, impacted neither their cell traversal capacity, host cell invasionin vitro, nor infectivityin vivo. Together, these data reveal a previously unappreciated complexity of thePlasmodiumsporozoite surface proteome and the roles of surface proteins in distinct biological activities of sporozoites.

scholarly journals Betulin Promotes Differentiation of Human Osteoblasts In Vitro and Exerts an Osteoinductive Effect on the hFOB 1.19 Cell Line Through Activation of JNK, ERK1/2, and mTOR Kinases

Molecules ◽  
2019 ◽  
Vol 24 (14) ◽  
pp. 2637 ◽  
Author(s):  
Magdalena Mizerska-Kowalska ◽  
Adrianna Sławińska-Brych ◽  
Katarzyna Kaławaj ◽  
Aleksandra Żurek ◽  
Beata Pawińska ◽  
...  
Keyword(s):  
Cell Lines ◽  
Osteoblast Differentiation ◽  
Mrna Level ◽  
Osteogenic Potential ◽  
Type I ◽  
Differentiation Markers ◽  
Alizarin Red ◽  
Human Osteoblasts ◽  
Osteogenic Supplement

Although betulin (BET), a naturally occurring pentacyclic triterpene, has a variety of biological activities, its osteogenic potential has not been investigated so far. The aim of this study was to assess the effect of BET on differentiation of human osteoblasts (hFOB 1.19 and Saos-2 cells) in vitro in osteogenic (with ascorbic acid as an osteogenic supplement) and osteoinductive (without an additional osteogenic supplement) conditions. Osteoblast differentiation was evaluated based on the mRNA expression (RT-qPCR) of Runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), type I collagen-α1 (COL1A1), and osteopontin (OPN). Additionally, ALP activity and production of COL1A1 (western blot analysis) and OPN (ELISA) were evaluated. The level of mineralization (calcium accumulation) was determined with Alizarin red S staining. BET upregulated the mRNA level of RUNX2 and the expression of other osteoblast differentiation markers in both cell lines (except the influence of BET on ALP expression/activity in the Saos-2 cells). Moreover, it increased mineralization in both cell lines in the osteogenic conditions. BET also increased the mRNA level of osteoblast differentiation markers in both cell lines (except for ALP in the Saos-2 cells) in the osteoinductive conditions, which was accompanied with increased matrix mineralization. The osteoinductive activity of BET in the hFOB 1.19 cells was probably mediated via activation of MAPKs (JNK and ERK1/2) and mTOR, as the specific inhibitors of these kinases abolished the BET-induced osteoblast differentiation. Our results suggest that BET has the potential to enhance osteogenesis.

scholarly journals Steroid metabolism in vitro during final oocyte maturation in white croaker Micropogonias furnieri (Pisces: Scianidae)

2004 ◽  
Vol 64 (2) ◽  
pp. 211-220 ◽  
Author(s):  
J. García-Alonso ◽  
A. Nappa ◽  
G. Somoza ◽  
A. Rey ◽  
D. Vizziano
Keyword(s):  
Oocyte Maturation ◽  
Basic Knowledge ◽  
Enzymatic Oxidation ◽  
Steroid Synthesis ◽  
Fishery Resource ◽  
White Croaker ◽  
Final Oocyte Maturation ◽  
Micropogonias Furnieri ◽  
Derivatives Of

Final oocyte maturation (FOM) is a process involving a complex set of genetical, biochemical, and morphological mechanisms. FOM involves the shift of a post-vitellogenic follicle to a pre-ovulated oocyte, which is necessary for fertilization by spermatozoan to occur. This process is regulated by a maturation-inducing steroid (MIS) at the follicular level. In other species of scienids fish the MIS, a hydroxilated derivatives of progestagen 17, 20beta, 21-trihydroxy-4-pregnen-3-one (20beta-S), was identified. Although Micropogonias furnieri is the second fishery resource of Uruguay, basic knowledge about its endocrine process is very scarce. The aim of this work was to investigate what steroids are synthesized in vitro by the oocyte follicle of M. furnieri during the maturation process. Fragments of ovary (1 g) in three stages: post-vitellogenic (PV), maturing (Mtg), and mature (M) were incubated with 1 mug.g-1 of tritiated progesterone (P) at 30, 60, and 180 min. After extraction with ethanol and dichloromethane, steroid metabolites were purified by TLC and rpHPLC. Two progesterone derivatives with identical chromatographic properties of 20beta-S and 17,20beta-dihydroxy-4-pregnen-3-one (17,20beta-P) were purified. In other Teleost fish these steroids are biologically activ as MIS. The 17,20beta-P was clearly detected in Mtg and M stages and confirmed by enzymatic oxidation with enzyme 20beta-HSD. The 20beta-S was strongly detected in all Mtg oocytes. The results do not corroborate 20beta-S as a major hormone synthesized in the ovary in FOM as occurs in other scienid fish. A differential steroid synthesis in the advanced oocyte stages suggests that the 20beta-S is acting as a MIS in M. furnieri.

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