Evidence for differences in low density lipoprotein processing by porcine granulosa and luteal cells in vitro: effect of addition of serum for plating of granulosa cells on lipoprotein metabolism

1989 ◽  
Vol 122 (2) ◽  
pp. 557-564 ◽  
Author(s):  
K. Rajkumar ◽  
H. Ly ◽  
P. W. Schott ◽  
B. Njaa ◽  
B. D. Murphy
Keyword(s):  
Granulosa Cells ◽  
Time Course ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Luteal Cells ◽  
Serum Withdrawal ◽  
Progesterone Secretion ◽  
Vitro Effect

ABSTRACT The present studies were carried out to compare the low density lipoprotein (LDL) metabolism by freshly isolated immature porcine granulosa cells with that by luteal cells. Furthermore, we have examined the effect of serum used for plating of granulosa cells on lipoprotein degradation and utilization. In incubation studies, addition of LDL as an exogenous substrate had a mild stimulatory effect on progesterone accumulation by granulosa cells, while it exhibited a dose-dependent stimulatory effect on luteal cells. When granulosa and luteal cells were incubated with 125I-labelled LDL, membrane binding of LDL occurred in both cell types, but only luteal cells were capable of internalizing the bound LDL. Granulosa cells in incubation degraded LDL much less in comparison with luteal cells, and the amount varied with the maturity of the cells. When granulosa cells were plated with graded amounts of serum which was withdrawn for 48 h following plating, they exhibited enhanced LDL degradation in a serum concentration-dependent fashion. Addition of serum for plating selectively enhanced utilization of LDL, but not high density lipoprotein (HDL) for progesterone accumulation by the cells in culture. Time-course studies on LDL degradation by granulosa cells following serum withdrawal indicate that the ability of cells to degrade LDL decreased in a time-dependent fashion. Serum withdrawal selectively decreased utilization of LDL but not HDL for progesterone secretion. It is concluded that immature granulosa cells have a limited capability to utilize cholesterol carried by LDL. However, when cultured in the presence of serum, cells acquire the ability to utilize more efficiently LDL-carried cholesterol for progesterone secretion which is then lost following long-term withdrawal of serum from culture. Journal of Endocrinology (1989) 122, 557–564

scholarly journals Oxidized Low-Density Lipoprotein Promotes In Vitro Calcification

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5120
Author(s):  
Mamiko Yamashita ◽  
Yoshiaki Nomura ◽  
Misao Ishikawa ◽  
Shinji Shimoda ◽  
Nobuhiro Hanada
Keyword(s):  
Electron Microscopy ◽  
Calcium Phosphate ◽  
Human Body ◽  
Time Course ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Ectopic Calcification ◽  
Low Density ◽  
Oxidized Low Density Lipoprotein

Calcification plays an important role in the human body in maintaining homeostasis. In the human body, the presence of a high amount of oxidized low-density lipoprotein (ox-LDL) is a consistent feature of the local areas that are common sites of ectopic calcification, namely dental calculus, renal calculus, and the areas affected by arteriosclerosis. Hence, ox-LDL may have some effect on calcification. Scanning electron microscopy (SEM) observation revealed a high amount of amorphous calcium phosphate (ACP) when ox-LDL was included in the solution. In the in vitro experiment, the highest amount of precipitation of calcium phosphate was observed in the solution containing ox-LDL compared to the inclusion of other biomaterials and was 4.2 times higher than that of deionized water for 4.86 mM calcium and 2.71 mM phosphate. The morphology of calcium phosphate precipitates in the solution containing ox-LDL differed from that of the precipitates in solutions containing other biomaterials, as determined by transmission electron microscopy (TEM). Through the time course observation of the sediments using TEM, it was observed that the sediments changed from spherical or oval shape to a thin film shape. These results indicate that sediments acquired a long-range order array, and the phase transitioned from non-crystalline to crystalline with an increased time and density of ACP. Thus, it is concluded that ox-LDL promoted ACP precipitation and it plays an important role in ectopic calcification.

Prolactin, LH, and estradiol-17β in utilization of lipoprotein substrate by porcine granulosa cells in vitro

1988 ◽  
Vol 66 (5) ◽  
pp. 561-566 ◽  
Author(s):  
K. Rajkumar ◽  
P. Klingshorn ◽  
P. J. Chedrese ◽  
B. D. Murphy
Keyword(s):  
Granulosa Cell ◽  
Cell Cultures ◽  
Granulosa Cells ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Porcine Granulosa Cells ◽  
Progesterone Synthesis ◽  
Serum Free Conditions

Porcine granulosa cells cultured under serum free conditions responded by increased progesterone secretion to the addition of the leuteotropic hormones, LH, prolactin, and estradiol. Provision of extracellular substrate for steroidogenesis in the form of porcine high density lipoprotein or low density lipoprotein enhanced progesterone accumulation by granulosa cell cultures. Estradiol, LH, and prolactin all greatly increased progesterone accumulation in the presence of either high or low density lipoproteins. Increases in progesterone accumulation following addition of prolactin or LH in combination with estradiol suggested the presence of a synergistic interaction among leuteotropins. Pre-exposure of granulosa cell cultures to estradiol increased the subsequent stimulatory effect of prolactin on lipoprotein utilization. It is concluded that all three leuteotropins function to enhance and may interact in the utilization of extracellular lipoprotein substrate for progesterone synthesis.

Serum Cholinesterase Activity in Hyperlipidemia and the In Vitro Effect of Isoniazid on Serum Cholinesterase

1972 ◽  
Vol 50 (1) ◽  
pp. 32-34 ◽  
Author(s):  
K. M. Kutty ◽  
J. C. Jacob
Keyword(s):  
Cholinesterase Activity ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Significant Rise ◽  
Serum Cholinesterase ◽  
Low Density ◽  
Lipoprotein Concentration ◽  
Serum Cholinesterase Activity ◽  
Vitro Effect

Increased serum Cholinesterase activity was observed in hyperlipidemic patients. When hyperlipidemia was induced in rabbits by injecting the lipopolysaccharide of Escherichia coli, a significant rise in serum low density lipoproteins and Cholinesterase activity occurred.In vitro experiments demonstrated that isoniazid produced proportionate decreases in serum low density lipoprotein concentration and in serum Cholinesterase activity.

Time course of oxysterol formation during in vitro oxidation of low density lipoprotein

1995 ◽  
Vol 78 (2) ◽  
pp. 119-128 ◽  
Author(s):  
Susanna Dzeletovic ◽  
Amir Babiker ◽  
Erik Lund ◽  
Ulf Diczfalusy
Keyword(s):  
Time Course ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density

scholarly journals Reductions of copper ion-mediated low-density lipoprotein (LDL) oxidations of trypsin inhibitors, the sweet potato root major proteins, and LDL binding capacities

2020 ◽  
Vol 61 (1) ◽  
Author(s):  
Yeh-Lin Lu ◽  
Chia-Jung Lee ◽  
Shyr-Yi Lin ◽  
Wen-Chi Hou
Keyword(s):  
Sweet Potato ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Trypsin Inhibitors ◽  
Water Soluble ◽  
Affinity Column ◽  
Low Density ◽  
Native Page

Abstract Background The root major proteins of sweet potato trypsin inhibitors (SPTIs) or named sporamin, estimated for 60 to 80% water-soluble proteins, exhibited many biological activities. The human low-density lipoprotein (LDL) showed to form in vivo complex with endogenous oxidized alpha-1-antitrypsin. Little is known concerning the interactions between SPTIs and LDL in vitro. Results The thiobarbituric-acid-reactive-substance (TBARS) assays were used to monitor 0.1 mM Cu2+-mediated low-density lipoprotein (LDL) oxidations during 24-h reactions with or without SPTIs additions. The protein stains in native PAGE gels were used to identify the bindings between native or reduced forms of SPTIs or soybean TIs and LDL, or oxidized LDL (oxLDL). It was found that the SPTIs additions showed to reduce LDL oxidations in the first 6-h and then gradually decreased the capacities of anti-LDL oxidations. The protein stains in native PAGE gels showed more intense LDL bands in the presence of SPTIs, and 0.5-h and 1-h reached the highest one. The SPTIs also bound to the oxLDL, and low pH condition (pH 2.0) might break the interactions revealed by HPLC. The LDL or oxLDL adsorbed onto self-prepared SPTIs-affinity column and some components were eluted by 0.2 M KCl (pH 2.0). The native or reduced SPTIs or soybean TIs showed different binding capacities toward LDL and oxLDL in vitro. Conclusion The SPTIs might be useful in developing functional foods as antioxidant and nutrient supplements, and the physiological roles of SPTIs-LDL and SPTIs-oxLDL complex in vivo will investigate further using animal models.

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