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Immunonutrition Therapy for COVID-19
Published in Srijan Goswami, Chiranjeeb Dey, COVID-19 and SARS-CoV-2, 2022
Srijan Goswami, Ushmita Gupta Bakshi, Dona Khamaru
As vitamin D enters the cytoplasm, a protein called vitamin D receptor protein (a cytoplasmic protein) binds to it, transports it inside the nucleus, and activates specific gene expression. These gene expression events activate the production of two major groups of proteins having antimicrobial properties, one is cathelicidins and the other one is called β-defensins (see Figure 16.3). β-Defensins shows its antimicrobial activity primarily by destroying the viral (in this case SARS-CoV-2) cell membrane or envelope which is composed of a phospholipid bilayer. So, Vitamin D potentially leads to the destruction of viruses by increasing the expression of β-defensins (see Figure 16.4) (Martineau et al., 2017; Cutolo et al., 2020).
Calcipotriol
Published in Anton C. de Groot, Monographs in Contact Allergy, 2021
Calcipotriol is a synthetic vitamin D derivative usually formulated for topical dermatological use as antipsoriatic. It competes with vitamin D for vitamin D-receptors in regulating cell proliferation and differentiation. Calcipotriol thereby induces differentiation and suppresses proliferation of keratinocytes, reversing abnormal keratinocyte changes in psoriasis, and leads to normalization of epidermal growth. It is indicated as monotherapy or in a combination product with betamethasone dipropionate for the treatment of moderate plaque psoriasis. In pharmaceutical products, calcipotriol is usually employed as calcipotriol monohydrate (CAS number 147657-22-5, EC number not available, molecular formula C27H42O4) (1).
Lifestyle Factors in Cancer Survivorship
Published in Pat Price, Karol Sikora, Treatment of Cancer, 2020
These are both higher among those who exercise regularly outdoors. The mechanism by which vitamin D influences the incidence and progression of cancer is thought to be due to calcitriol’s effect on cellular proliferation, differentiation, and apoptosis. The vitamin D receptor is highly expressed in epithelial cells known to be at risk of carcinogenesis, such as the breast, skin, and prostate. Low vitamin D levels are linked to higher relapse rates after colorectal, breast, and prostate cancer, although a direct causational link has not been established, nor has any benefit of correcting vitamin D levels with supplementation. Sunlight exposure, independently of vitamin D levels, has been linked to a lower incidence of prostate cancer. It has been postulated that sunlight exposure may have other benefits, such as modulation of the immune system and the circadian rhythm.38,39
Vitamin D Receptor Expression Is Significantly Decreased in Bone Metastases Compared to Matched Primary Breast Cancer Tumours
Published in Cancer Investigation, 2023
Konstantin Horas, Marc Abraham, Regina Ebert, Manuel Weissenberger, Gerrit S. Maier, Franz Jakob, Andreas Rosenwald, Maximilian Rudert
In summary, this study may serve as a pilot study providing evidence that disruption of the vitamin D signalling pathway via downregulation of the VDR could be associated with breast cancer metastasis to bone. It has become evident that several factors are likely to contribute to a dysregulation of vitamin D metabolism and VDR signalling in cancer cells. Presumably, numerous mechanistic pathways exist that alter vitamin D signalling in tumour cells, including an impressive array of epigenetic events in vitamin D responsive target genes. At least in vitro modulators of histone (de)acetylases and/or methyltransferases can restore VDR expression, and hence this may open up new possibilities to restore tumour suppressor mechanisms. The capability of breast cancer cells to alter VDR expression is one such way that eventually enables them to escape the growth inhibitory signals that are normally triggered through VDR signalling. For clinical purposes, therefore, assessing tumour VDR expression (together with serum vitamin D status) might be a useful tool and prognostic factor in breast cancer patients for predicting bone metastases and unfavourable outcomes (50). Nonetheless, translation of these findings to prevent or treat breast cancers and their skeletal secondaries via targeting the vitamin D pathway have yet to be confirmed (38).
Overview of gene expression techniques with an emphasis on vitamin D related studies
Published in Current Medical Research and Opinion, 2023
Jeffrey Justin Margret, Sushil K. Jain
The genomic effects of vitamin D are mediated by the vitamin D receptor (VDR); nearly 3% of the human genome is regulated by the active form of vitamin D62. VDR binds the active form of vitamin D to form a heterodimeric complex with the retinoic acid X receptor, which in turn binds to vitamin D response elements (VDRE) in the DNA. A variety of transcription factors attach to this complex, which results in either upregulation or downregulation of the genes involved in cell proliferation, differentiation, and mineral homeostasis63. The expression of vitamin D regulatory genes can be used as biomarkers for different actions of vitamin D in various tissues and the cells they express and for the assessment of susceptibilities64. It is important to study the distribution of VDR expression in different tissues to determine the function of vitamin D in regulating various biological processes. In addition, to determine the importance of local vitamin D synthesis, independent of synthesis taking place in the liver and kidney, it is vital to understand the expression of genes necessary for active vitamin D synthesis65.
Lower vitamin D levels and VDR FokI variants are associated with susceptibility to sepsis: a hospital-based case-control study
Published in Biomarkers, 2022
Xinyue Yang, Jin Ru, Zhengchao Li, Xingpeng Jiang, Chuming Fan
Vitamin D mediates its functions by binding to one member of the nuclear receptor superfamily termed as Vitamin D receptor (VDR). The expression of VDRs has been reported in a wide range of cells such as monocytes, neutrophils, platelets, macrophages, and dendric cells (Dowd et al.2013, Li et al.2002). VDR is coaded by the VDR gene located in the long arm of the 12th chromosome (13.11). Although several single nucleotide polymorphisms (SNPs) in the VDR gene have been identified, four functional SNPs (FokI, TaqI, BsmI, and ApaI) have been extensively studied in various genetic association studies. The studies on the link between common genetic variants and vulnerability to sepsis development is scant and contradictory. The VDR FokI TT genotype and allele T have been linked to neonatal Sepsis in Egyptian (Tayel et al.2018); however, no significant association of VDR polymorphisms (FokI, TaqI, BsmI, and ApaI) was observed in neonates of Odisha, India (Das et al.2016). Furthermore, the FokI CC genotype was related to the risk of Sepsis in Serbian adults (Zeljic et al.2017). To the best of our knowledge, no research has been conducted on the possibility of a connection between VDR common variants and susceptibility to sepsis manifestation in the Chinese population.