Endogenous Metabolite

Cellular cholesterol concentration decreased by 20–31% after GT1-7 hypothalamus cells were depleted of cholesterol in vitro. Reduced phosphorylation/activation of IRS-1 and AKT was observed in all cholesterol-depleted neuron-derived cells when stimulated with insulin, insulin-like growth factor 1, or neurotrophic factors (NGF and BDNF). Lowering cellular cholesterol also raises baseline autophagy and hinders glucose deprivation-induced autophagy activation [1].

Models of scaffolded hyperlipidemia can be created using cholesterol in animal models.

Diabetes mellitus is associated with a variety of complications, including alterations in the central nervous system (CNS). We have recently shown that diabetes results in a reduction of cholesterol synthesis in the brain due to decreased insulin stimulation of SREBP2-mediated cholesterol synthesis in neuronal and glial cells. In the present study, we explored the effects of the decrease in cholesterol on neuronal cell function using GT1-7 hypothalamic cells subjected to cholesterol depletion in vitro using three independent methods: 1) exposure to methyl-β-cyclodextrin, 2) treatment with the HMG-CoA reductase inhibitor simvastatin, and 3) shRNA-mediated knockdown of SREBP2. All three methods produced 20-31% reductions in cellular cholesterol content, similar to the decrease in cholesterol synthesis observed in diabetes. All cholesterol-depleted neuron-derived cells, independent of the method of reduction, exhibited decreased phosphorylation/activation of IRS-1 and AKT following stimulation by insulin, insulin-like growth factor-1, or the neurotrophins (NGF and BDNF). ERK phosphorylation/activation was also decreased after methyl-β-cyclodextrin and statin treatment but increased in cells following SREBP2 knockdown. In addition, apoptosis in the presence of amyloid-β was increased. Reduction in cellular cholesterol also resulted in increased basal autophagy and impairment of induction of autophagy by glucose deprivation. Together, these data indicate that a reduction in neuron-derived cholesterol content, similar to that observed in diabetic brain, creates a state of insulin and growth factor resistance that could contribute to CNS-related complications of diabetes, including increased risk of neurodegenerative diseases, such as Alzheimer disease [3].

Cholesterol can be used for constructing aimal models of hyperlipidemia, atherosclerosis, and so on.

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Induction of hyperlipidemia
Pathogenic principle: Hyperlipidemia is a group of diseases characterized by elevated circulating lipid concentrations, including cholesterol, cholesterol esters, phospholipids, and triglycerides. If the intake of cholesterol is excessive and exceeds the body's metabolic capacity, it may lead to an increase in plasma cholesterol levels and induce hyperlipidemia.
Detailed methods for constructing hyperlipidemia model
Rats: Wistar • male • 18 week old (period: 8 weeks)
Administration: 2% cholesterol; Diet-8 weeks
Note
(1) The rats were placed in a room with 22 ± 2 ° C room temperature and 12 h light dark cycle
(2) Wistar rats were always selected for the study of hyperlipidemia, because the serum cholesterol and triglyceride levels of this species were moderately increased due to high cholesterol diet, and no substantial atherosclerosis occurred; Therefore, it is possible to study the direct effect of hyperlipidemia on myocardium in this model, independent of atherosclerosis.
Markers of successful construction of hyperlipidemia model: Total cholesterol levels in blood samples significantly increase (approximately 20%)

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Induction of atherosclerosis
Pathogenic principle: High levels of cholesterol in the blood, especially low density lipoprotein cholesterol (LDL-C), may accumulate on the vascular wall to form plaque, a process known as atherosclerosis. Over time, these plaques may block blood flow, leading to serious health problems such as myocardial ischemia or myocardial infarction.
Detailed methods for constructing atherosclerosis model
Rabbits: Oryctolagus cuniculus • male • 4-6 month old (period: 16 weeks)
Administration: 0.3% cholesterol and 3% soybean oil; DIET • 16 weeks
Note
(1) High cholesterol rabbit is a model widely used in experimental research of atherosclerosis, because cholesterol can only cause atherosclerosis changes in the intima of rabbit arteries, which is very similar to human atherosclerosis.
(2) Due to the absorption of dietary cholesterol requiring fat, oil must be added to the diet. Otherwise, rabbits will use their internal fat to make them thin or sick. In addition, using soybean oil containing unsaturated fatty acids can prevent high plasma cholesterol levels. Other vegetable oils, such as peanut oil or corn oil, can also be used because they are unsaturated fatty acids. It is not recommended to consume animal fats (saturated fatty acids), such as butter and lard.
(3) Most experiments recommend using a cholesterol diet of 0.3-0.5%. Rabbits cannot tolerate a cholesterol diet of 1-2% for more than a month as they can develop severe liver dysfunction.
(4) Adult rabbits over 4 months old can consume approximately 150 grams per day. Free feeding or restricted feeding (100-150 grams/day/adult rabbit) is allowed.
(5) Blood lipids should be measured weekly, especially for the first 4 weeks, as you need to determine whether the plasma cholesterol levels of each animal are elevated. If the plasma cholesterol level of non responsive rabbits does not increase after feeding with cholesterol feed, they can be excluded from the experiment.
(6) Plasma lipoprotein can be measured at 8 and 16 weeks, during which plasma cholesterol levels remain stable.
(7) The age of rabbits should be considered, because even though their plasma cholesterol levels are similar, young rabbits are more likely to suffer from atherosclerosis than older rabbits. Rabbits aged 4-6 months are typically used for cholesterol feeding experiments.
(8) Male and female rabbits have different responses to cholesterol diet and atherosclerosis. Based on our experience, female rabbits suffer from higher levels of hypercholesterolemia and larger aortic lesions than male rabbits. In general, it is recommended to conduct experiments on male rabbits as estrogen may affect the results.
Markers of successful construction of therosclerosis model: Histological changes: HE staining of aortic arch and sections of thoracic aorta showed atherosclerosis

[1]. Casaburi I, et al. Cholesterol as an Endogenous ERRα Agonist: A New Perspective to Cancer Treatment. Front Endocrinol (Lausanne). 2018 Sep 11;9:525.
[2]. Dietschy JM, et al. Thematic review series: brain Lipids. Cholesterol metabolism in the central nervous system during early development and in the mature animal. J Lipid Res. 2004 Aug;45(8):1375-97.
[3]. Fukui K, et al. Effect of Cholesterol Reduction on Receptor Signaling in Neurons. J Biol Chem. 2015 Sep 14.

C27H46O

386.66

386.3549

C, 83.87; H, 11.99; O, 4.14

57-88-5

Cholesterol (Water Soluble);Cholesterol-d7;83199-47-7;Cholesterol-d6;60816-17-3;Cholesterol-d6-1;92543-08-3;Cholesterol-13C2;78887-48-6;Cholesterol-d4;956029-28-0;Cholesterol myristate;1989-52-2;Cholesterol-13C5;150044-24-9;Cholesterol-13C3;Cholesterol-d;51467-57-3;Cholesterol-18O;59613-51-3

White to off-white solid

Endogenous Metabolite

8.7

20.2Ų

O([H])[C@@]1([H])C([H])([H])C([H])([H])[C@@]2(C([H])([H])[H])C(C1([H])[H])=C([H])C([H])([H])[C@]1([H])[C@]2([H])C([H])([H])C([H])([H])[C@]2(C([H])([H])[H])[C@@]([H])([C@]([H])(C([H])([H])[H])C([H])([H])C([H])([H])C([H])([H])C([H])(C([H])([H])[H])C([H])([H])[H])C([H])([H])C([H])([H])[C@]21[H]

HVYWMOMLDIMFJA-DPAQBDIFSA-N

InChI=1S/C27H46O/c1-18(2)7-6-8-19(3)23-11-12-24-22-10-9-20-17-21(28)13-15-26(20,4)25(22)14-16-27(23,24)5/h9,18-19,21-25,28H,6-8,10-17H2,1-5H3/t19-,21+,22+,23-,24+,25+,26+,27-/m1/s1

(3S,8S,9S,10R,13R,14S,17R)-10,13-dimethyl-17-((R)-6-methylheptan-2-yl)-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-ol

AI3 03112 CCRIS 2834; AI303112; AI3-03112

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Ethanol : ~20 mg/mL (~51.73 mM)
DMSO :< 1 mg/mL

Solubility in Formulation 1: ≥ 1.43 mg/mL (3.70 mM) (saturation unknown) in 10% EtOH + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 14.3 mg/mL clear EtOH stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 1.43 mg/mL (3.70 mM) (saturation unknown) in 10% EtOH + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 14.3 mg/mL clear EtOH stock solution to 900 μL of corn oil and mix well.

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 (Please use freshly prepared in vivo formulations for optimal results.)