VARYING RESPONSE TO LUTEINIZING HORMONE OF TWO LUTEAL CELL TYPES ISOLATED FROM BOVINE CORPUS LUTEUM

1979 ◽  
Vol 83 (3) ◽  
pp. 303-NP ◽  
Author(s):  
JOCELYNE URSELY ◽  
PIERRE LEYMARIE

Luteal cell suspensions obtained by enzymatic digestion of pregnant cow corpus luteum were found to be heterogenous and mainly made up of two types of cells of different sizes. The large cells (37 μm, average diameter) could be separated from the small ones (18 μm, average diameter) by sedimentation at unit gravity in a gradient of Ficoll–bovine serum albumin. A comparative in-vitro study of the synthesis of progesterone by the two types of cells indicated striking differences between them. The average content and the synthesis of progesterone in the absence and presence of a saturating dose of bovine LH after incubation for 2 h were 0·07, 0·12 and 6·9 pg/cell for the small cells and 0·65, 2 and 10 pg/cell for the large ones. Moreover, the sensitivity to low concentrations of LH was 100 to 1000 times higher for the small cells than for the large ones. oestradiol-17β at concentrations ranging from 5 × 10−10 to 5 × 10−4 mol/l exerted a dose–dependent inhibition on the stimulation of LH in both cell types. These results suggest a possible involvement of both cell types in the synthesis of progesterone in vivo with a greater contribution by the small cells to stimulation induced by LH. Moreover, it appears that small cell suspensions could be a useful model system for in-vitro studies of the control of the synthesis of progesterone in cow corpus luteum.

2005 ◽  
Vol 289 (6) ◽  
pp. G1091-G1099 ◽  
Author(s):  
Kazunobu Nonome ◽  
Xiao-Kang Li ◽  
Terumi Takahara ◽  
Yusuke Kitazawa ◽  
Naoko Funeshima ◽  
...  

Human umbilical cord blood (HUCB) contains stem/progenitor cells, which can differentiate into a variety of cell types. In this study, we investigated whether HUCB cells differentiate into hepatocytes in vitro and in vivo. We also examined whether CD34 could be the selection marker of stem cells for hepatocytes. HUCB cells were obtained from normal full-term deliveries, and CD34+/−cells were further separated. For in vitro study, HUCB cells were cultured for 4 wk, and expressions of liver-specific genes were examined. For the in vivo study, nonobese diabetic/severe combined immunodeficient mice were subjected to liver injury by a Fas ligand-carried adenoviral vector or only radiated. Mice were treated simultaneously with or without cell transplantation of HUCB, CD34+, or CD34−cells. After 4 wk, human-specific gene/protein expression was examined. In the in vitro study, human liver-specific genes were positive after 7 days of culture. The immunofluorescent study showed positive staining of α-fetoprotein, cytokeratin 19, and albumin in round-shaped cells. In the in vivo study, immunohistochemical analysis showed human albumin-positive, hepatocyte-specific antigen-positive cells in mouse livers of the Fas ligand/transplantation group. Fluorescence in situ hybridization analysis using the human Y chromosome also showed positive signals. However, no difference between transplanted cell types was detected. In contrast, immunopositive cells were not detected in the irradiated/transplantation group. The RT-PCR result also showed human hepatocyte-specific gene expressions only in the Fas ligand/transplantation group. HUCB cells differentiated into hepatocyte-like cells in the mouse liver, and liver injury was essential during this process. The differences between CD34+and CD34−cells were not observed in human hepatocyte-specific expression.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zonghao Tang ◽  
Jiajie Chen ◽  
Zhenghong Zhang ◽  
Jingjing Bi ◽  
Renfeng Xu ◽  
...  

The increase of oxidative stress is one of the important characteristics of mammalian luteal regression. Previous investigations have revealed the essential role of reactive oxygen species (ROS) in luteal cell death during luteolysis, while it is unknown how ROS is regulated in this process. Considering the decrease of blood flow and increase of PGF2α during luteolysis, we hypothesized that the HIF-1α pathway may be involved in the regulation of ROS in the luteal cell of the late corpus luteum (CL). Here, by using a pseudopregnant rat model, we showed that the level of both HIF-1α and its downstream BNIP3 was increased during luteal regression. Consistently, we observed the increase of autophagy level during luteolysis, which is regulated in a Beclin1-independent manner. Comparing with early (Day 7 of pseudopregnancy) and middle CL (Day 14), the level of ROS was significantly increased in late CL, indicating the contribution of oxidative stress in luteolysis. Inhibition of HIF-1α by echinomycin (Ech), a potent HIF-1α inhibitor, ameliorated the upregulation of BNIP3 and NIX, as well as the induction of autophagy and the accumulation of ROS in luteal cells on Day 21 of pseudopregnancy. Morphologically, Ech treatment delayed the atrophy of the luteal structure at the late-luteal stage. An in vitro study indicated that inhibition of HIF-1α can also attenuate PGF2α-induced ROS and luteal cell apoptosis. Furthermore, the decrease of cell apoptosis can also be observed by ROS inhibition under PGF2α treatment. Taken together, our results indicated that HIF-1α signaling is involved in the regression of CL by modulating ROS production via orchestrating autophagy. Inhibition of HIF-1α could obviously hamper the apoptosis of luteal cells and the process of luteal regression.


1983 ◽  
Vol 19 (1) ◽  
pp. 811-815 ◽  
Author(s):  
Mori Takahide ◽  
Nihnobu Kenji ◽  
Takeuchi Satoru ◽  
Onho Yoshio ◽  
Tojo Shimpei

Reproduction ◽  
2014 ◽  
Vol 148 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Heather Talbott ◽  
Abigail Delaney ◽  
Pan Zhang ◽  
Yangsheng Yu ◽  
Robert A Cushman ◽  
...  

Recent studies have suggested that chemokines may mediate the luteolytic action of prostaglandin F2α (PGF). Our objective was to identify chemokines induced by PGFin vivoand to determine the effects of interleukin 8 (IL8) on specific luteal cell typesin vitro. Mid-cycle cows were injected with saline or PGF, ovaries were removed after 0.5–4 h, and expression of chemokine was analyzed by qPCR.In vitroexpression of IL8 was analyzed after PGF administration and with cell signaling inhibitors to determine the mechanism of PGF-induced chemokine expression. Purified neutrophils were analyzed for migration and activation in response to IL8 and PGF. Purified luteal cell types (steroidogenic, endothelial, and fibroblast cells) were used to identify which cells respond to chemokines. Neutrophils and peripheral blood mononuclear cells (PBMCs) were cocultured with steroidogenic cells to determine their effect on progesterone production.IL8,CXCL2,CCL2, andCCL8transcripts were rapidly increased following PGF treatmentin vivo. The stimulatory action of PGF onIL8mRNA expressionin vitrowas prevented by inhibition of p38 and JNK signaling. IL8, but not PGF, TNF, or TGFB1, stimulated neutrophil migration. IL8 had no apparent action in purified luteal steroidogenic, endothelial, or fibroblast cells, but stimulated ERK phosphorylation in neutrophils. In coculture experiments neither IL8 nor activated neutrophils altered basal or LH-stimulated luteal cell progesterone synthesis. In contrast, activated PBMCs inhibited LH-stimulated progesterone synthesis from cultured luteal cells. These data implicate a complex cascade of events during luteolysis, involving chemokine signaling, neutrophil recruitment, and immune cell action within the corpus luteum.


1982 ◽  
Vol 94 (1) ◽  
pp. 193-200 ◽  
Author(s):  
E L Khoury

Using indirect immunofluorescence (IFL) on viable human thyroid cultures, it has been shown that, although adult follicular cells do not express blood group ABH antigens in vivo, they invariably reexpress the corresponding antigens on the cell surface when cultured in monolayers, even for very short periods. The absence of blood group antigens on noncultured thyroid cells was confirmed by negative IFL on cell suspensions obtained after enzymatic digestion of the glands, whereas these antigens were readily demonstrable on cell suspensions obtained by trypsinization of established monolayers. The quantitative expression of ABH antigens on individual thyroid cells was variable and the cell-surface IFL pattern due to binding of blood group isoantibodies was different from that given by organ-specific thyroid autoantibodies on viable cultures. Reexpression of blood group antigens by cultured thyroid cells could not be related to the secretor status of the donors, the presence of a particular source of serum in the culture medium or cell division in vitro. After 2-3 wk in culture, thyroid cells became morphologically dedifferentiated and no longer displayed blood group antigens, though they still expressed cell-surface beta 2-microglobulin. Fibroblasts present in the primary thyroid cultures were invariably negative for ABH antigens. These results demonstrate that the surface antigenic repertoire of cultured human cells is not necessarily identical to that present on the same cells in vivo. Furthermore, the possibility that blood group natural isoantibodies bind to the cell surface must be taken into account in experiments in which cultured thyroid cells are exposed to human sera.


1994 ◽  
Vol 72 (11-12) ◽  
pp. 531-536 ◽  
Author(s):  
Nicholas Kenny ◽  
Rachel E. Williams ◽  
Lorraine B. Kelm

At the end of a nonconception estrous cycle, the sheep corpus luteum undergoes involution (luteolysis), a process thought to involve apoptotic deletion of cells. It is not yet clear which of the heterogeneous luteal cell types is involved or what mechanisms drive the apoptotic progression. We examined intact paraffin-embedded corpora lutea (in situ terminal dUTP nick end-labeling method) and found direct evidence for apoptotic deletion of cells during luteolysis, but not in healthy, nonregressing corpora lutea. We then sought to implement in vitro models to dissect apoptotic mechanisms in the constituent cells of the corpus luteum. Cells prepared using standard collagenase dispersion of corpus luteum were evaluated for evidence of apoptosis (DNA laddering) by direct agarose gel electrophoresis, a method that obviates the need for DNA extraction, so allowing examination of relatively few cells (≤ 0.5 × 106). When cells were prepared from nonregressing corpus luteum for in vitro manipulation, a population(s) of cells undergoing spontaneous apoptosis was detected. Apoptosis was inhibited by Zn2+ (5 mM), by the tyrosine phosphatase inhibitor sodium orthovanadate (100 μM), or by maintenance at 4 °C. It appears that simple collagenase digestion of intact corpus luteum removes a subset of constituent cells from their survival signal, leading to rapid initiation of endonuclease activity and apoptotic cell death. Identification of the required survival factors and their actions is being pursued to facilitate development of appropriate in vitro models for this endocrine system.Key words: corpus luteum, apoptosis.


1997 ◽  
Vol 154 (2) ◽  
pp. 249-257 ◽  
Author(s):  
R K Arioua ◽  
C Féral ◽  
A Benhaïm ◽  
B Delarue ◽  
P Leymarie

Abstract It is well established that the rabbit corpus luteum (CL) function depends upon endogenous oestradiol, the major source of which in the rabbit ovary is considered to be the ovarian follicles. The absence of oestradiol formation by the rabbit CL has been previously reported. In a hyperstimulated pseudopregnant rabbit model used in our laboratory which developed a large number of corpora lutea in response to chorionic gonadotrophin (eCG)/hCG, we observed the survival of corpora lutea in vivo, and normal levels of plasma progesterone throughout pseudopregnancy (PP), despite the scarcity or the absence of follicles as a source of the luteotrophic hormone. Measurement of oestradiol in the plasma indicated that it was at high levels and correlated with the number of corpora lutea. This led us to investigate the luteal origin of oestradiol in this model. PP was induced in rabbits by i.m. injection of 200 IU eCG daily for 2 days followed on day 4 by i.m. injection of 200 IU hCG (day 0 of PP). Luteal tissue obtained at days 5, 9 and 12 of PP and cultured for 24 h synthesized oestradiol and testosterone in addition to progesterone. However, under the same conditions, follicles had limited capacity to secrete oestradiol. The presence of an aromatase activity in luteal tissue was confirmed when exogenous testosterone was added to the culture medium. P450aromatase (P450arom) mRNA was found in luteal tissue at days 5, 9 and 12 of PP. Small or large luteal cells, obtained by enzymatic digestion of the tissue followed by centrifugation in a Percoll density gradient, were cultured during several days with or without gonadotrophin or dibutyryl cAMP (dbcAMP). Both types of cells secreted oestradiol. In small cells and luteal tissue, aromatase activity was stimulated (1·5–2-fold) by hCG and dbcAMP. Large cells exhibited a greater capacity to aromatize testosterone than small cells, but aromatase activity was not modified by hCG or by dbcAMP. FSH had no effect on aromatase activity of either luteal cell type. This intrinsic luteal tissue aromatase capacity and the absence of premature regression of corpora lutea despite the limited support of follicular oestrogen, suggest an autocrine and luteotrophic role for this luteal oestrogen. Journal of Endocrinology (1997) 154, 249–257


2015 ◽  
Vol 309 (3) ◽  
pp. C139-C147 ◽  
Author(s):  
Sean Martin ◽  
Huey Lin ◽  
Chukwuemeka Ejimadu ◽  
Techung Lee

Recent studies of myocardial infarction in secreted Frizzled-related protein 2 (sFRP2) knockout mice and our hamster heart failure therapy based on sFRP2 blockade have established sFRP2 as a key profibrotic cytokine in the heart. The failing hamster heart is marked by prominent fibrosis and calcification with elevated expression of sFRP2. Noting the involvement of tissue-nonspecific alkaline phosphatase (TNAP) in bone mineralization and vascular calcification, we determined whether sFRP2 might be an upstream regulator of TNAP. Biochemical assays revealed an approximately twofold increase in the activity of TNAP and elevated levels of inorganic phosphate (Pi) in the failing heart compared with the normal heart. Neither was this change detected in the liver or hamstring muscle nor was it associated with systemic hyperphosphatemia. TNAP was readily cloned from the hamster heart and upon overexpression increased the level of extracellular but not intracellular Pi, which is consistent with the cell surface location of the ectoenzyme. In line with the previous demonstration that sFRP2 blockade attenuated fibrosis, we show here that the therapy downregulated TNAP. This in vivo finding is corroborated by the in vitro study showing that cultured cardiac fibroblasts treated with recombinant sFRP2 protein exhibited progressive increase in the expression and activity of TNAP, which was completely abrogated by cycloheximide or tunicamycin. Induction of TNAP by sFRP2 is restricted to cardiac fibroblasts among the multiple cell types examined, and was not observed with sFRP4. The current work indicates that sFRP2 may promote cardiac fibrocalcification through coordinate activation of tolloid-like metalloproteinases and TNAP.


2015 ◽  
Vol 18 (2) ◽  
pp. 64-73
Author(s):  
Truong Tat Dang ◽  
Thuan Cong Nguyen ◽  
Hieu Van Tran

hGM-CSF (human granulocytemacrophage colony stimulating factor) is a cytokine secreted by many cell types. Its characters are suitable for vaccine adjuvant such as ability to stimulate survival, differentiation and enhancement the functions of antigen-presenting cells. This cytokine is also a chemoattractant for monocytes and neutrophils to the infected sites, stimulates the expression of several cytokines like IL-1, IL-6, TNF, which are essential for B and T lymphocyte differentiation. However, hGM-CSF has some drawbacks for being an adjuvant candidate due to its easy degradation, toxicity at high concentration and low-dose requirement for therapeutic effect. Drugs delivery system using chitosan can overcome these disadvantages of hGM-CSF. In this present study, chitosan particles were prepared and evaluated the absorption and release of human hGM-CSF. Firstly, the activity of hGM CSF was evaluated by proliferation bioassay using TF-1 cell line. Afterward, chitosan particles were prepared by ionic gelation method and were examined for its toxicity on TF‑1 cell line. After protein absorbance onto chitosan particles, the release capacity and in vitro protection of chitosan for hGM-CSF were assessed. The result showed that hGM-CSF had an ED50 value of 106 pg/mL. The synthesized chitosan particles had an average diameter of 24.5 nm and were nontoxic. Based on the results of SDS-PAGE and Bradford, the adsorption efficiency of hGM‑CSF onto chitosan particles reached 99 % and chitosan has the ability to release hGM-CSF and protects it from hydrolysis of trypsin. In conclusion, the synthesized chitosan beads absorbed and released hGMCSF with its activity remained. This result provides the evidence for further in vivo researches.


1983 ◽  
pp. 811-815
Author(s):  
TAKAHIDE MORI ◽  
KENJI NIHNOBU ◽  
SATORU TAKEUCHI ◽  
YOSHIO ONHO ◽  
SHIMPEI TOJO

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