Synthesis of New Vitamin K Analogues as Steroid and Xenobiotic Receptor (SXR) Agonists: Insights into the Biological Role of the Side Chain Part of Vitamin K

2011 ◽  
Vol 54 (13) ◽  
pp. 4918-4922 ◽  
Author(s):  
Yoshitomo Suhara ◽  
Masato Watanabe ◽  
Sayaka Motoyoshi ◽  
Kimie Nakagawa ◽  
Akimori Wada ◽  
...  
Keyword(s):  
Vitamin K ◽  
Biological Role ◽  
Side Chain ◽  
Steroid And Xenobiotic Receptor ◽  
Xenobiotic Receptor

Metabolism and cell biology of vitamin K

2008 ◽  
Vol 100 (10) ◽  
pp. 530-547 ◽  
Author(s):  
Paul Newman ◽  
Martin J. Shearer
Keyword(s):  
Vitamin K ◽  
Cell Biology ◽  
Side Chain ◽  
Local Synthesis ◽  
Anticoagulant Drugs ◽  
Clinical Benefits ◽  
Steroid And Xenobiotic Receptor ◽  
Plant Form ◽  
Specific Tissue ◽  
Xenobiotic Receptor

SummaryNaturally occurring vitamin K compounds comprise a plant form, phylloquinone (vitamin K1) and a series of bacterial menaquinones (MKs) (vitamin K2). Structural differences in the isoprenoid side chain govern many facets of metabolism of K vitamins including the way they are transported, taken up by target tissues, and subsequently excreted. In the post-prandial state, phylloquinone is transported mainly by triglyceride-rich lipoproteins (TRL) and long-chain MKs mainly by low-density lipoproteins (LDL). TRL-borne phylloquinone uptake by osteoblasts is an apoE-mediated process with the LRP1 receptor playing a predominant role. One K2 form, MK-4, has a highly specific tissue distribution suggestive of local synthesis from phylloquinone in which menadione is an intermediate. Both phylloquinone and MKs activate the steroid and xenobiotic receptor (SXR) that initiates their catabolism, but MK-4 specifically upregulates two genes suggesting a novel MK-4 signalling pathway. Many studies have shown specific clinical benefits of MK-4 at pharmacological doses for osteoporosis and cancer although the mechanism(s) are poorly understood. Other putative non-cofactor functions of vitamin K include the suppression of inflammation, prevention of brain oxidative damage and a role in sphingolipid synthesis. Anticoagulant drugs block vitamin K recycling and thereby the availability of reduced vitamin K. Under extreme blockade, vitamin K can bypass the inhibition of Gla synthesis in the liver but not in the bone and the vessel wall. In humans, MK-7 has a greater efficacy than phylloquinone in carboxylating both liver and bone Gla proteins. A daily supplement of phylloquinone has shown potential for improving anticoagulation control.

scholarly journals Evaluating the Role of the Steroid and Xenobiotic Receptor (SXR/PXR) in PCB-153 Metabolism and Protection against Associated Adverse Effects during Perinatal and Chronic Exposure in Mice

2020 ◽  
Vol 128 (4) ◽  
pp. 047011
Author(s):  
Riann Jenay Egusquiza ◽  
Maria Elena Ambrosio ◽  
Shuyi Gin Wang ◽  
Kaelen Marie Kay ◽  
Chunyun Zhang ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Chronic Exposure ◽  
Steroid And Xenobiotic Receptor ◽  
Xenobiotic Receptor

Biological Role of Vitamin K at the Molecular Level

2015 ◽  
pp. 202-209 ◽  
Author(s):  
B. Connor Johnson ◽  
Jean Marie Girardot ◽  
Eric T. Suen ◽  
Donald O. Mack ◽  
Robert A. Floyd ◽  
...  
Keyword(s):  
Vitamin K ◽  
Molecular Level ◽  
Biological Role

scholarly journals PROX1 suppresses vitamin K-induced transcriptional activity of steroid and xenobiotic receptor

2011 ◽  
Vol 16 (11) ◽  
pp. 1063-1070 ◽  
Author(s):  
Kotaro Azuma ◽  
Tomohiko Urano ◽  
Tetsuro Watabe ◽  
Yasuyoshi Ouchi ◽  
Satoshi Inoue
Keyword(s):  
Vitamin K ◽  
Transcriptional Activity ◽  
Steroid And Xenobiotic Receptor ◽  
Xenobiotic Receptor

scholarly journals Structure-Activity Relationship of Novel Vitamin K Analogues as Steroid and Xenobiotic Receptor (SXR) Agonists

2012 ◽  
Vol 132 (8) ◽  
pp. 881-886 ◽  
Author(s):  
Yoshitomo Suhara ◽  
Sayaka Motoyoshi ◽  
Yoshihisa Hirota ◽  
Natsumi Sawada ◽  
Kimie Nakagawa ◽  
...  
Keyword(s):  
Vitamin K ◽  
Structure Activity Relationship ◽  
Activity Relationship ◽  
Structure Activity ◽  
Steroid And Xenobiotic Receptor ◽  
Xenobiotic Receptor ◽  
Relationship Of

scholarly journals Vitamin K and Osteoporosis

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3625
Author(s):  
Maria Fusaro ◽  
Giuseppe Cianciolo ◽  
Maria Luisa Brandi ◽  
Serge Ferrari ◽  
Thomas L. Nickolas ◽  
...  
Keyword(s):  
Vitamin K ◽  
Bone Health ◽  
Clinical Studies ◽  
Therapeutic Agent ◽  
Vascular System ◽  
Bone Fractures ◽  
Active Form ◽  
Matrix Gla Protein ◽  
Steroid And Xenobiotic Receptor ◽  
Xenobiotic Receptor

Vitamin K acts as a coenzyme of carboxylase, catalyzing the carboxylation of several vitamin K dependent proteins. Beyond its well-known effects on blood coagulation, it also exerts relevant effects on bone and the vascular system. In this review, we point out the relevance of an adequate vitamin K intake to obtain sufficient levels of carboxylated (active form) vitamin K dependent proteins (such as Osteocalcin and matrix Gla protein) to prevent bone health. Another bone-related action of Vitamin K is being a ligand of the nuclear steroid and xenobiotic receptor (SXR). We also discuss the recommended intake, deficiency, and assessment of vitamin K. Furthermore, we review the few available studies that have as pre-specified outcome bone fractures, indicating that we need more clinical studies to confirm that vitamin K is a potential therapeutic agent for bone fractures.

From Organizations of Processes to Organisms and Other Biological Individuals

2018 ◽  
Author(s):  
Argyris Arnellos
Keyword(s):  
Multicellular Organism ◽  
Collaborative Networks ◽  
Biological Role ◽  
Regulatory Processes ◽  
Different Types ◽  
Organizational Framework

The emphasis on the collaborative dimension of life overlooks the importance of biological individuals (conceived of as integrated, self-maintaining organizations) in the build-up of more complex collaborative networks in the course of evolution. This chapter proposes a process-based organizational ontology for biology, according to which the essential features of unicellular organismicality are captured by a self-maintaining organization of processes integrated by means of a special type of collaboration (realized through regulatory processes entailing an indispensable interdependence) between its constitutive and its interactive aspects. This ontology is then used to describe different types of collaborations among cells and to suggest the type that yields a multicellular organism. The proposed organizational framework enables us to critically assess hypercollaborative views of life, especially issues related to the distinction between biological individuals and organisms and between life and non-life, without however underestimating the central biological role of collaboration.

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