scholarly journals Core clock gene Bmal1 deprivation impairs steroidogenesis in mice luteinized follicle cells

Reproduction ◽  
2020 ◽  
Vol 160 (6) ◽  
pp. 955-967
Author(s):  
Yizi Wang ◽  
Minghui Chen ◽  
Jian Xu ◽  
Xinyan Liu ◽  
Yuwei Duan ◽  
...  

Luteinization is the event of corpus luteum formation, a way of follicle cells transformation and a process of steroidogenesis alteration. As the core clock gene, Bmal1 was involved in the regulation of ovulation process and luteal function afterwards. Till now, the underlying roles of luteinization played by Bmal1 remain unknown. To explore the unique role of Bmal1 in luteal steroidogenesis and its underlying pathway, we investigated the luteal hormone synthesis profile in Bmal1 knockout female mice. We found that luteal hormone synthesis was notably impaired, and phosphorylation of PI3K/NfκB pathway was significantly activated. Then, the results were verified in in vitro cultured cells, including isolated Bmal1 interference granulosa cells (GCs) and theca cells (TCs), respectively. Hormones levels of supernatant culture media and mRNA expressions of steroidogenesis-associated genes (star, Hsd3β2, cyp19a1 in GCs, Lhcgr, star, Hsd3β2, cyp17a1 in TCs) were mutually decreased, while the phosphorylation of PI3K/NfκB was promoted during in vitro luteinization. After PI3K specific-inhibitor LY294002 intervention, mRNA expressions of Lhcgr and Hsd3β2 were partially rescued in Bmal1 interference TCs, together with significantly increased androstenedione and T synthesis. Further exploration in TCs demonstrated BMAL1 interacted directly but negatively with NfκB p65 (RelA), a subunit which was supposed as a mediator in Bmal1-governed PI3K signaling regulation. Taken together, we verified the novel role of Bmal1 in luteal steroidogenesis, achieving by negative interplay with RelA-mediated PI3K/NfκB pathway.

2020 ◽  
Vol 10 (1) ◽  
pp. 78
Author(s):  
April Nettesheim ◽  
Myoung Sup Shim ◽  
Angela Dixon ◽  
Urmimala Raychaudhuri ◽  
Haiyan Gong ◽  
...  

Extracellular matrix (ECM) deposition in the trabecular meshwork (TM) is one of the hallmarks of glaucoma, a group of human diseases and leading cause of permanent blindness. The molecular mechanisms underlying ECM deposition in the glaucomatous TM are not known, but it is presumed to be a consequence of excessive synthesis of ECM components, decreased proteolytic degradation, or both. Targeting ECM deposition might represent a therapeutic approach to restore outflow facility in glaucoma. Previous work conducted in our laboratory identified the lysosomal enzyme cathepsin B (CTSB) to be expressed on the cellular surface and to be secreted into the culture media in trabecular meshwork (TM) cells. Here, we further investigated the role of CTSB on ECM remodeling and outflow physiology in vitro and in CSTBko mice. Our results indicate that CTSB localizes in the caveolae and participates in the pericellular degradation of ECM in TM cells. We also report here a novel role of CTSB in regulating the expression of PAI-1 and TGFβ/Smad signaling in TM cells vitro and in vivo in CTSBko mice. We propose enhancing CTSB activity as a novel therapeutic target to attenuate fibrosis and ECM deposition in the glaucomatous outflow pathway.


2021 ◽  
Author(s):  
Hijam Nonibala ◽  
Braj Bansh Prasad Gupta

Abstract Transcription of arylalkylamine N-acetyltransferase 2 (aanat2) gene leads to formation of AANAT2 - the rate-limiting enzyme in melatonin synthesis pathway in photosensitive fish pineal organ. However, unlike in avian and mammalian pineal gland, there is practically no information on signal transduction pathway(s) involved in regulation of aanat2 gene transcription in the fish pineal organ. Therefore, we investigated the role of important molecular components of signalling via cAMP, cGMP, Ca2+ involving PKA, PKG, PKC, MeK and p38 MAP kinase as well as possible role of serine/threonine phosphatases, CREB and CBP using their specific inhibitors and/or activators in aanat2 gene transcription in the fish pineal organ maintained under in vitro culture-conditions. db-cAMP and db-cGMP stimulated the expression of aanat2 gene. db-cAMP- and cGMP-induced aanat2 gene expression was significantly reduced in the presence of H-89 (specific inhibitor of PKA), KT5823 (specific inhibitor of PKG), chelerythrine chloride (specific inhibitor of PKC), U0126 ethanolate (specific inhibitor of MeK) and SB 202190 monohydrochloride hydrate (specific inhibitor of p38 MAP kinase). Inhibitors of PP1 and PP2A significantly increased aanat2 gene expression as well as significantly reduced cAMP- and cGMP-induced gene transcription, while inhibitor of PP2B had no effect on aanat2 gene expression. Inhibitors of both CREB and CBP-CREB interaction completely blocked cAMP-induced aanat2 gene transcription. Based on these findings, we suggest that cAMP, cGMP and Ca2+ stimulate aanat2 gene transcription via PKA, PKG and PKC, respectively. Further, protein phosphatases and CBP-CREB-CRE pathway are actively involved in regulation of on aanat2 gene expression in the fish pineal organ.


Development ◽  
1974 ◽  
Vol 31 (2) ◽  
pp. 513-526
Author(s):  
M. H. Kaufman ◽  
M. A. H. Surani

Eggs from (C57B1 × A2G)F1 mice were activated by treatment with hyaluronidase, which removed the follicle cells, and cultured in vitro. Observations were made 6–8 h after hyaluronidase treatment to determine the frequency of activation and the types of parthenogenones induced. Cumulus-free eggs resulting from hyaluronidase treatment were incubated for 2¼ h in culture media of various osmolarities. The frequency of activation was found to be dependent on the postovulatory age of oocytes, while the types of parthenogenones induced were dependent on the osmolarity of the in vitro culture medium and their postovulatory age. Culture in low osmolar medium suppressed the extrusion of the second polar body (2PB). This decreased the incidence of haploid eggs with a single pronucleus and 2PB and immediately cleaved eggs from 97·5% to 42·3% of the activated population. Where 2PB extrusion had been suppressed, 97·4% of parthenogenones contained two haploid pronuclei. Very few were observed with a single and presumably diploid pronucleus. Serial observations from 11 to 18 h after hyaluronidase treatment were made on populations of activated eggs as they entered the first cleavage mitosis after 2¼ h incubation in medium either of normal (0·287 osmol) or low (0·168 osmol) osmolarity. A delay in the time of entry into the first cleavage mitosis similar to the duration of incubation in low osmolar medium was observed. Further, eggs were incubated in control and low osmolar culture media containing uniformly labelled [U-14C]amino acid mixture to examine the extent of protein synthesis in recently activated eggs subjected to these culture conditions. An hypothesis is presented to explain the effect of incubation in low osmolar culture medium in delaying the first cleavage mitosis.


2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Olan Jackson-Weaver ◽  
Jian Wu ◽  
Yongchao Gou ◽  
Yibu Chen ◽  
Meng Li ◽  
...  

Rationale: Epicardial epithelial-to-mesenchymal trasition (EMT) is a vital process in embryonic heart development. During EMT, epicardial cells acquire migratory and invasive properties, and differentiate into new cell types, including cardiac fibroblasts and coronary smooth muscle cells. Non-histone protein methylation is an emerging modulator of cell signaling. We have recently established a role for protein arginine methyltransferase-1 (PRMT1) in TGF-β-induced EMT in cultured cells. Objective: To determine the role of PRMT1 in epicardial EMT. Methods and Results: We investigated the role of PRMT1 in epicardial EMT in mouse epicardial cells. Embryonic day 9.5 (E9.5) tamoxifen administration of WT1-Cre ERT ;PRMT1 fl/fl ;ROSA-YFP fl/fl mouse embryos was used to delete PRMT1 in the epicardium. Epicardial PRMT1 deletion led to reduced epicardial migration into the myocardium, a thinner compact myocardial layer, and dilated coronary blood vessels at E15.5. Using the epicardial cell line MEC1, we found that PRMT1 siRNA prevented the increase in mesenchymal proteins Slug and Fibronectin and the decrease in epithelial protein E-Cadherin during TGF-β treatment-induced EMT. PRMT1 siRNA also reduced the migration and invasion of MEC1 cells. We further identified that PRMT1 siRNA also increased the expression of p53, a key regulator of the Slug degradation pathway. PRMT1 siRNA increases p53 expression by decreasing p53 degradation, and shifted p53 localization to the cytoplasm. In vitro methylation assays further demonstrated that PRMT1 methylates p53. Knockdown of p53 increased Slug levels and enhanced EMT, establishing p53 as a regulator of epicardial EMT through controlling Slug expression. Furthermore, RNAseq experiments in MEC1 cells demonstrated that 40% (545/1,351) of TGF-β-induced transcriptional changes were prevented by PRMT1 siRNA. Furthermore, when p53 and PRMT1 were simultaneously knocked down, TGF-β induced transcriptional control of 37% (201/545) of these PRMT1-dependent genes was restored. Conclusions: The PRMT1-p53-Slug pathway is necessary for epicardial EMT in cultured MEC1 cells as well as in the epicardium in vivo . Epicardial PRMT1 is required for the development of compact myocardium and coronary blood vessels.


Cancers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3530
Author(s):  
Jessica Gambardella ◽  
Antonella Fiordelisi ◽  
Gaetano Santulli ◽  
Michele Ciccarelli ◽  
Federica Andrea Cerasuolo ◽  
...  

The involvement of GRK2 in cancer cell proliferation and its counter-regulation of p53 have been suggested in breast cancer even if the underlying mechanism has not yet been elucidated. Furthermore, the possibility to pharmacologically inhibit GRK2 to delay cancer cell proliferation has never been explored. We investigated this possibility by setting up a study that combined in vitro and in vivo models to underpin the crosstalk between GRK2 and p53. To reach this aim, we took advantage of the different expression of p53 in cell lines of thyroid cancer (BHT 101 expressing p53 and FRO cells, which are p53-null) in which we overexpressed or silenced GRK2. The pharmacological inhibition of GRK2 was achieved using the specific inhibitor KRX-C7. The in vivo study was performed in Balb/c nude mice, where we treated BHT-101 or FRO-derived tumors with KRX-C7. In our in vitro model, FRO cells were unaffected by GRK2 expression levels, whereas BHT-101 cells were sensitive, thus suggesting a role for p53. The regulation of p53 by GRK2 is due to phosphorylative events in Thr-55, which induce the degradation of p53. In BHT-101 cells, the pharmacologic inhibition of GRK2 by KRX-C7 increased p53 levels and activated apoptosis through the mitochondrial release of cytochrome c. These KRX-C7-mediated events were also confirmed in cancer allograft models in nude mice. In conclusion, our data showed that GRK2 counter-regulates p53 expression in cancer cells through a kinase-dependent activity. Our results further corroborate the anti-proliferative role of GRK2 inhibitors in p53-sensitive tumors and propose GRK2 as a therapeutic target in selected cancers.


Reproduction ◽  
2001 ◽  
pp. 89-96 ◽  
Author(s):  
AA Murray ◽  
MD Molinek ◽  
SJ Baker ◽  
FN Kojima ◽  
MF Smith ◽  
...  

Ascorbic acid has three known functions: it is necessary for collagen synthesis, promotes steroidogenesis and acts as an antioxidant. Within the ovary, most studies have concentrated on the role of ascorbic acid in luteal formation and regression and little is known about the function of this vitamin in follicular growth and development. Follicular growth and development were investigated in this study using an individual follicle culture system that allows the growth of follicles from the late preantral stage to Graafian morphology. Follicles were isolated from prepubertal mice and cultured for 6 days. Control media contained serum and human recombinant FSH. Further groups of follicles were cultured in the same media but with the addition of ascorbic acid at concentrations of either 28 or 280 micromol l(-1). Addition of ascorbic acid at the higher concentration significantly increased the percentage of follicles that maintained basement membrane integrity throughout culture (P < 0.001). Ascorbic acid had no effect on the growth of the follicles or on oestradiol production. Metalloproteinase 2 activity tended to increase at the higher concentration of ascorbic acid and there was a significant concomitant increase in the activity of tissue inhibitor of metalloproteinase 1 (P < 0.01). Follicles cultured without the addition of serum but with FSH and selenium in the culture media underwent apoptosis. Addition of ascorbic acid to follicles cultured under serum-free conditions significantly reduced apoptosis (P < 0.05). From these data it is concluded that ascorbic acid is necessary for remodelling the basement membrane during follicular growth and that the ability of follicles to uptake ascorbic acid confers an advantage in terms of granulosa cell survival.


Author(s):  
Qian Wang ◽  
Yi Zhao

Live cells from most of the membranous tissues such as alveoli are subjected to equi-biaxial strain originated from their extracellular environments. To understand the role of equi-biaxial strain in live cells, a number of engineered methods have been developed for applying such mechanical strain to in vitro cultured cells. Among these methods, deforming a flexible substrate on a circular platen has been widely used [1], and has been miniaturized into millimeter scale for parallel stretching assay (Figure 1a). Nonetheless, the strain homogeneity becomes increasingly challenging at smaller scale, since it requires an ultra-thin membrane, an indentation platen with well controlled dimension, and the highly precise alignment. This obviously increases the fabrication and operation complexities. Devices that deliver homogeneous strain with minimal fabrication and assembling complexities are needed.


Reproduction ◽  
2014 ◽  
Vol 148 (2) ◽  
pp. 221-235 ◽  
Author(s):  
Juan M Gallardo Bolaños ◽  
Carolina M Balao da Silva ◽  
Patricia Martín Muñoz ◽  
Antolín Morillo Rodríguez ◽  
María Plaza Dávila ◽  
...  

AKT, also referred to as protein kinase B (PKB or RAC), plays a critical role in controlling cell survival and apoptosis. To gain insights into the mechanisms regulating sperm survival after ejaculation, the role of AKT was investigated in stallion spermatozoa using a specific inhibitor and a phosphoflow approach. Stallion spermatozoa were washed and incubated in Biggers–Whitten–Whittingham medium, supplemented with 1% polyvinyl alcohol (PVA) in the presence of 0 (vehicle), 10, 20 or 30 μM SH5, an AKT inhibitor. SH5 treatment reduced the percentage of sperm displaying AKT phosphorylation, with inhibition reaching a maximum after 1 h of incubation. This decrease in phosphorylation was attributable to either dephosphorylation or suppression of the active phosphorylation pathway. Stallion spermatozoa spontaneously dephosphorylated during in vitro incubation, resulting in a lack of a difference in AKT phosphorylation between the SH5-treated sperm and the control after 4 h of incubation. AKT inhibition decreased the proportion of motile spermatozoa (total and progressive) and the sperm velocity. Similarly, AKT inhibition reduced membrane integrity, leading to increased membrane permeability and reduced the mitochondrial membrane potential concomitantly with activation of caspases 3 and 7. However, the percentage of spermatozoa exhibiting oxidative stress, the production of mitochondrial superoxide radicals, DNA oxidation and DNA fragmentation were not affected by AKT inhibition. It is concluded that AKT maintains the membrane integrity of ejaculated stallion spermatozoa, presumably by inhibiting caspases 3 and 7, which prevents the progression of spermatozoa to an incomplete form of apoptosis.Free Spanish abstractA Spanish translation of this abstract is freely available at http://www.reproduction-online.org/content/148/2/221/suppl/DC1.


1985 ◽  
Vol 101 (4) ◽  
pp. 1487-1491 ◽  
Author(s):  
H Katow ◽  
M Hayashi

We studied the effect of fibronectin (FN) on the behavior of primary mesenchyme cells isolated from sea urchin mesenchyme blastulae in vitro using a time-lapse technique. The migration of isolated primary mesenchyme cells reconstituted in seawater and horse serum is dependent on the presence or absence of exogenous FN in the culture media. The cells in FN, 4 and 40 micrograms/ml, show a high percentage of migration and migrate long distances, whereas a higher concentration of FN at 400 micrograms/ml tends to inhibit migration.


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