Related Experiment Video
Updated: Jul 5, 2026

Encapsulation Thermogenic Preadipocytes for Transplantation into Adipose Tissue Depots
Published on: June 2, 2015
1Alpha, 25-dihydroxyvitamin D and corticosteroid regulate adipocyte nuclear vitamin D receptor
Objective:
We previously demonstrated that high calcium diets inhibit obesity in both mice and humans; this effect is mediated, in part, by dietary calcium suppression of 1alpha, 25-dihydroxyvitamin D, which exerts both non-genomic and genomic effects on adipocyte metabolism. However, the presence of the nuclear vitamin D receptor (nVDR) and its role in this regulation in adipocytes have not been investigated.
Methods And Results:
The nVDR is expressed at low levels in preadipocytes, and differentiation induced a rapid 1150% increase within 3 h (P<0.001), which then declined rapidly to preadipocyte levels at differentiation day 3. However, this was not a differentiation event, as the components of the differentiation mixture (isobutylmethylxanthine and dexamethasone) also increased nVDR expression markedly by 1620 and 284%, respectively, in fully differentiated adipocytes (P<0.05). 1alpha, 25-Dihydroxyvitamin D and 11beta-dehydrocorticosterone each stimulated nVDR expression at 48 h, but not 3 h, by approximately 650% in fully differentiated adipocytes, whereas the combination augmented this effect (P<0.005). Knockdown of 11beta-hydroxysteroid dehydrogenase I (11beta-HSD I) markedly decreased adipocyte nVDR expression and attenuated 1alpha, 25-dihydroxyvitamin D stimulation of nVDR. Thus, 1alpha, 25-dihydroxyvitamin D stimulation of corticosteroid synthesis via the 11beta-HSD appears to provide an indirect positive feedback on the nVDR. 1alpha, 25-Dihydroxyvitamin D also regulated short-term corticosterone release independently of either 11beta-HSD I or nVDR. Knockdown 11beta-HSD I did not affect short-term corticosterone release, whereas modulating calcium influx by KCl, BAYK8644 and the membrane 1alpha, 25-dihydroxyvitamin D receptor agonist lumisterol markedly increased corticosterone release.
Conclusion:
These data suggest a potential role of nVDR and corticosterone in the regulation in adipocyte responses to 1alpha, 25-dihydroxyvitamin D and dietary calcium.
Related Concept Videos
Role of Skin in Vitamin D Synthesis
The solar UV B rays (290-315 nm) are absorbed by the skin, and 7-dehydrocholesterol (provitamin D3) photolyzes it to previtamin D3, which undergoes a rapid transformation to vitamin D3(cholecalciferol).
Transducer Mechanism: Nuclear Receptors
About 48 different soluble family members of nuclear receptors are identified that can be divided into two main classes:
Role of Vitamins in Maintaining Bone Health
Vitamin A
Vitamin A is involved in the process of bone remodeling. Retinoic acid, the active metabolite of Vitamin A, has nuclear receptors in osteoblasts and osteoclasts, which are involved in bone remodeling.
Vitamin B12
Vitamin B12 acts as a cofactor during the formation of osteoblast-related proteins, such as osteocalcin. Vitamin B12 plays a role...
Regulation of Nuclear Protein Sorting
Intracellular Hormone Receptors
Target Cell Response to Hormones
Notably, the cellular response can be regulated by altering the number of receptors expressed in the cell. For example, prolonged exposure to elevated hormone levels results in a gradual decline or down-regulation in the number of receptors for that specific hormone on the cell surface. Conversely, in response to low hormone levels, cells may use up-regulation, producing an...
