Role Of Vitamin K2 Research Articles

Role of vitamin K2 and vitamin K cycle enzymes in aortic valvular interstitial cell calcification

Abstract Introduction Calcific aortic valve disease (CAVD) is the most common valve disease. Currently, there is no medical treatment available for CAVD. Vitamin K antagonists promote CAVD while population-based studies suggest that dietary intake of vitamin K reduces the incidence of CAVD in adults. However, randomized trials have so far not proven a clear benefit of vitamin K supplementation on the progression of AVS. Consequently, there is a need for a deeper understanding of the role of vitamin K in valvular calcification. This study aims to further investigate mechanisms of action of vitamin K during valvular calcification. Methods and Results Aortic valve samples were obtained from patients undergoing surgical aortic valve replacement for CAVD and valvular interstitial cells (VIC) were isolated by collagenase II digestion (Fig. 1). VIC expressed typical markers like Vimentin and α-SMA and were cultured in a control medium (CM) or further calcified in a pro-calcifying medium (PCM) containing sodium dihydrogen phosphate and ascorbic acid. PCM led to upregulation of Runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP) expression, and ALP-activity after 7 and 21 days of culture. Moreover, alizarin red staining visualized significant calcium mineral deposition after 21 days of culture (Fig. 2). The addition of the most potent vitamin K2 derivative (Menaquinone-7, MK-7) improved cell viability under both control and calcifying conditions (Fig. 3). Moreover, MK-7 protected VIC from ferroptotic cell death (Fig. 4) and increased expression of the vitamin K-dependent Matrix-Gla-protein (MGP), a major inhibitor of ectopic calcification (Fig. 5). To fulfill its function as an activator of vitamin K-dependent proteins like MGP, vitamin K needs to be reduced to vitamin K hydroquinone by the vitamin K epoxide reductase enzymes VKORC1 and VKORC1L1. In VIC, using our calcification protocol, treatment with PCM led to the downregulation of VKORC1, but not of VKORC1L1, an enzyme with known anti-oxidative properties (Fig. 6). We next performed siRNA-mediated knockdown of VKORC1 and VKORC1L1 in VIC and observed calcification after 7 and 21 days of culture by measuring expression of ALP, RUNX2, quantifying ALP activity, and staining for calcium minerals (alizarin red). Intriguingly, VKORC1L1-knockdown sharply increased the expression of ALP. To further elucidate these findings, we will perform overexpression experiments to analyze, if VKORC1L1 can alleviate PCM-induced calcification Conclusion: Vitamin K2 inhibits in vitro calcification of valvular interstitial cells and upregulates the calcification inhibitor Matrix-Gla-Protein. Our results suggest the involvement of the vitamin K cycle enzyme VKORC1L1, which is known to exhibit anti-oxidative and cytoprotective effects. Further studies are warranted to shed light on the regulation of the enzymes to improve our understanding.

Role of vitamin K2 in bone-vascular crosstalk.

Vitamin K (VK) is a fat-soluble vitamin that is indispensable for the activation of vitamin K-dependent proteins (VKDPs). It has been shown to play an important role in the proper calcium deposit at the bone level, hindering that on the vascular walls. The deficiency of this vitamin in European populations is frequent and unknown. It is related to several factors, poor dietary intake, altered intestinal absorption or altered production by bacteria, indicating possible dysbiosis. For Vitamin K2 (VK2), there is currently no official reference daily intake (RDI). However, the effects of VK2 on the improvement of health in cardiovascular diseases, on bone metabolism, on chronic kidney diseases have been the subject of research in recent decades. The microbiota in the gastrointestinal tract plays an important role: Bacteroides are primarily capable of synthetizing very long chain forms of menaquinones and, in addition to the bacteria present in the intestinal flora, VK2 is also produced by bacteria used in food fermentation processes. This review provides an update on the current literature regarding the origin of VK2 and its implications in what is called the "calcium paradox", namely the lack of calcium in the bone and its storage in the wall of the vessel.

Vitamin K2 Awareness in Sun-Protected Patients Supplementing With Vitamin D.

Dermatologists often recommend vitamin D for sun-protected patients. Most patients are not aware of the key role vitamin K2 plays in vitamin D metabolism and do not receive sufficient dietary vitamin K2. A survey of 50 sun-protecting patients shows 4/50 understood the role of vitamin K2 and 1/50 was supplementing vitamin K2. Therefore, counseling on vitamin K2 supplementation may be of benefit to sun-protected dermatology patients. J Drugs Dermatol. 2021;20(2):228-229. doi:10.36849/JDD.2021.5829.

Vitamin K2 in multiple sclerosis patients.

SummaryBackgroundVitamin K2 (VK2) belongs to the vitamin K family and comprises a number of subtypes differing in length of side chains consisting of isoprenoid groups (menaquinone-n, MK-n). It is essential for a number of physiological functions although the full spectrum of activity has not yet been elucidated. Due to its role in protection of mitochondrial damage, VK2 could be relevant in preventing disease progress in multiple sclerosis (MS).MethodsWe measured VK2 serum levels by the double antibody sandwich Enzyme-linked Immunosorbent Assay (ELISA) technique in MS patients and age and sex matched controls, both under vitamin D supplementation, and related it to disease characteristics and treatment.ResultsOverall, 45 MS patients (31 females and 39 of the relapsing-remitting type) and 29 healthy controls (19 females) were included in the analysis. The MS patients had vastly lower VK2 blood levels than controls (235 ± 100 ng/ml vs. 812 ± 154 ng/ml, respectively). Female patients had significantly lower VK2 levels than males and a decrease with age by approximately 10% per decade was found. The VK2 levels were lower with increasing numbers of attacks per year and were higher in patients with optic nerve lesions. No consistent relationship with medications was detected.ConclusionThe substantially lower levels of VK2 in MS patients could be due to depletion, lower production in the gut, diminished absorption or, less likely, reduced intake of precursor vitamin K1. The role of VK2 in MS development and progress deserves further study.Electronic supplementary materialThe online version of this article (10.1007/s00508-018-1328-x) contains supplementary material, which is available to authorized users.

Vitamin k dependent proteins and the role of vitamin k2 in the modulation of vascular calcification: a review.

Vascular calcification, a cause of cardiovascular morbidity and mortality, is an actively regulated process involving vitamin K dependent proteins (VKDPs) among others. Vitamin K is an essential micronutrient, present in plants and animal fermented products that plays an important role as a cofactor for the post-translational γ-carboxylation of glutamic acid residues in a number of proteins. These VKDPs require carboxylation to become biologically active, and they have been identified as having an active role in vascular cell migration, angiogenesis and vascular calcification. This paper will review the process of vascular calcification and delineate the role that vitamin K2 plays in the modulation of that process, through the activation of VKDPs. One such VKDP is Matrix Gla Protein (MGP), which when activated inhibits osteogenic factors, thereby inhibiting vascular and soft tissue calcification.

Evolving role of vitamin K2-7(Menaquinone) in Osteoporosis & cardiovascular health

Osteoporosis & cardiovascular disorders are one of the commonest global problem. These two disorders not only affect the quality of life but also put a huge financial burden on the family and the nation as a whole. Since ages we have been using calcium supplements for the management of osteoporosis and the recent reports have shown that it can lead to increased cardiovascular complications. Vitamin K2 ,an age old vitamin has been shown to take care of osteoporosis and cardiovascular complications, since it plays an important role in carboxylation of certain proteins in bone and blood vessel. This review article summarizes the role of vitamin K2 in osteoporosis 7 cardiovascular disorders and also throws light on the clinical evidences available for the same.

Role of vitamin K2 in preventing the recurrence of hepatocellular carcinoma after curative treatment: A meta-analysis of randomized controlled trials

BackgroundHepatocellular cancer is notorious for recurrence even after curative therapy. High recurrence determines the long term prognosis of the patients. Vitamin K2 has been tested in trials for its effect on prevention of recurrence and improving survival. The results are inconclusive from individual trials and in our knowledge no systematic review which entirely focuses on Vitamin K2 as a chemo preventive agent is available to date. This review is an attempt to pool all the existing trials together and update the existing knowledge on the topic.MethodsMedline, Embase and Cochrane Register of Controlled trials were searched for randomized controlled trials where vitamin K2 or its analogues, in any dosage were compared to placebo or No vitamin K2, for participants of any age or sex. Reference lists and abstracts of conference proceedings were searched by hand. Additional papers were identified by a manual search of the references from the key articles. Attempt was made to contact the authors of primary studies for missing data and with the experts in the field.Trials were assessed for inclusion by two independent reviewers. Primary outcomes were recurrence rates and survival rates. There were no secondary outcomes. Data was synthesized using a random effects model and results presented as relative risk with 95% Confidence Intervals.ResultFor recurrence of hepatocellular cancer after hepatic resection or local ablative therapy, compared with controls, participants receiving Vitamin K2, pooled relative risks for hepatocellular cancer were 0.60; 95% CI: 0.28–1.28, p = 0.64) at 1 yr 0.66; 95% CI: 0.47–0.91), p = 0.01) at 2 yr; 0.71; 95% CI: 0.58–0.85, p = 0.004) at 3 yr respectively. The results were combined using the random analysis model.ConclusionFive RCTs evaluated the preventive efficacy of menatetrenone on HCC recurrence after hepatic resection or local ablative therapy. The meta-analysis of all five studies, failed to confirm significantly better tumor recurrence- free survival at 1 year. Improved tumor recurrence at 2nd and 3rd year may be just due to insufficient data. There was no beneficial effect on the overall survival. However, to confirm the beneficial effect or lack of it, large, higher quality randomized controlled trials are still required.

破骨細胞に対するビタミンＫ２およびゲラニルゲラニルアセトンの作用

破骨細胞に対するビタミンＫ２およびゲラニルゲラニルアセトンの作用

Combined treatment with vitamin k2 and bisphosphonate in postmenopausal women with osteoporosis.

Vitamin K2, as well as bisphosphonates, such as etidronate, alendronate, and risedronate, is widely used in the treatment with osteoporosis in Japan. Etidronate increases the lumbar bone mineral density (BMD), and prevents new vertebral fractures, in patients with osteoporosis, while alendronate and risedronate increase the lumbar and femoral neck BMDs, and prevent new vertebral and femoral neck fractures. Vitamin K2 enhances gamma-carboxylation of bone glutamic acid residues and the secretion of osteocalcin, sustains the lumbar BMD, and prevents osteoporotic fractures in patients with osteoporosis. Bisphosphonates, such as alendronate and risedronate, rather than vitamin K2, should be initially chosen for the treatment of osteoporosis, because they are more efficacious than vitamin K2. Available evidence suggest that risedronate prevents deterioration of the connectivity of the trabeculae in ovariectomized rats, whereas vitamin K2 increase the trabecular thickness, and that a combination of risedronate and vitamin K2 has a synergistic effect on preventing the deterioration of trabecular bone architecture induced by estrogen deficiency. Some studies have shown that combined treatment with etidronate and vitamin K2 appears to be more effective than etidronate alone in the prevention of new osteoporotic vertebral fractures. Based on these findings, combined treatment with vitamin K2 and bisphosphonates may be more efficacious in the prevention new vertebral fractures than a single treatment with bisphosphonate in postmenopausal women with osteoporosis. Thus, this combined treatment should be recommended for the treatment of postmenopausal osteoporosis. It is proposed that the role of vitamin K2 should be emphasized, when used in combination with bisphosphonates, especially in patients with vitamin K deficiency.