Vitamin K1 and Vitamin K2 immunopharmacological effects on the peripheral lymphocytes of healthy subjects and dialysis patients, as estimated by the lymphocyte immunosuppressant sensitivity test

Dramatic Decrease of Vitamin K2 Subtype Menaquinone-7 in COVID-19 Patients

(1) Background: Vitamin K (VK) is a fat-soluble compound with a common chemical structure, a 2-methyl-1,4-naphthoquinone ring, and a variable aliphatic side-chain. VK is involved in the synthesis of blood-clotting proteins, bone stability, anti-oxidative, and immune inflammatory-modulatory functions. Vitamin K also activates protein S, which acts as an antioxidant and anti-inflammatory. The fact that cytokine overproduction, oxidative stress, and disturbed microcirculation by thrombogenicity play a central role in severe COVID-19 prompted us to analyze this vitamin. (2) Methods: We analyzed by a validated liquid-chromatography tandem mass-spectrometry method serum vitamin K1, MK4, MK7, and VK epoxide levels in 104 healthy controls, 77 patients with non-COVID-19 pneumonia, and 135 hospitalized COVID-19 patients with potentially fatal outcomes admitted to our University Hospital between April and November 2020. We included the quotient between VK and triglyceride (TG, nmol/mmol/L) values in the analyses with respect to the TG transporter function for all VK subtypes. Additionally, we assessed anthropometric, routine laboratory, and clinical data from the laboratory and hospital information systems. (3) Results: The COVID-19 patients had significantly lower MK7 levels than non-COVID-19 pneumonia patients and healthy controls. COVID-19 and non-COVID-19 pneumonia patients had significantly lower vitamin K1 and significantly higher MK4 compared to healthy controls, but did not differ significantly from each other. Between COVID-19 non-survivors (n = 30) and survivors (n = 105) no significant differences were seen in all vitamin K subtypes, despite the fact that non-survivors had higher peak concentrations of IL-6, CRP, d-dimer, and higher oxygen needs, respectively. (4) Conclusions: The present data identified significantly decreased vitamin K1, K2 (MK7), and increased MK4 levels in patients with COVID-19 compared to healthy controls. Vitamin K2 (MK7) was lowest in COVID-19 patients irrespective of potentially fatal courses, indicating consumption of this VK subtype by COVID-19 immanent effects, most probably inflammatory and oxidative stress factors.

Vitamin K2 Holds Promise for Alzheimer's Prevention and Treatment

Recent studies have highlighted the importance of vitamin K2 (VK2) in human health. However, there have been no clinical studies investigating the role of VK2 in the prevention or treatment of Alzheimer's disease (AD), a debilitating disease for which currently there is no cure. In reviewing basic science research and clinical studies that have connected VK2 to factors involved in AD pathogenesis, we have found a growing body of evidence demonstrating that VK2 has the potential to slow the progression of AD and contribute to its prevention. In our review, we consider the antiapoptotic and antioxidant effects of VK2 and its impact on neuroinflammation, mitochondrial dysfunction, cognition, cardiovascular health, and comorbidities in AD. We also examine the link between dysbiosis and VK2 in the context of the microbiome's role in AD pathogenesis. Our review is the first to consider the physiological roles of VK2 in the context of AD, and, given the recent shift in AD research toward nonpharmacological interventions, our findings emphasize the timeliness and need for clinical studies involving VK2.

Effects of vitamin K2 combined with methotrexate against mitogen-activated peripheral blood mononuclear cells of healthy subjects and rheumatoid arthritis patients

BACKGROUND

Methotrexate (MTX) is used as anchor drug for patients with early and established rheumatoid arthritis (RA). Vitamin K₂ administration was also reported to be associated with decreased disease activity in RA.

OBJECTIVES

Immunosuppressive pharmacodynamics of vitamin K₂ combined with MTX was investigated.

METHODS

Mitogen-activated peripheral blood mononuclear cells (PBMCs) were used to evaluate immunosuppressive pharmacodynamics of drugs in vitro.

RESULTS

Vitamin K₂ alone dose-dependently suppressed T cell mitogen-activated proliferation of PBMCs of both healthy subjects and RA patients. 446.5 and 2232.5 ng/mL vitamin K₂ significantly decreased the IC₅₀ values of MTX on the proliferation of PBMCs of RA patients, with little influences on the pharmacodynamics of MTX in the healthy PBMCs. 4465 ng/mL vitamin K₂ potentiated the pharmacodynamics of MTX in both RA patients and healthy PBMCs. The additional effects of vitamin K₂ to potentiate the suppressive effects of MTX seemed not to be related to the regulation of CD4⁺ CD25⁺ T cells or CD4⁺ CD25⁺ Foxp3⁺ Treg cells. MTX alone at 100 ng/mL significantly decreased the percentage of CD4⁺ T cells in PBMCs of healthy subjects (p < 0.001) with a slight influence in that of RA patients (not significant) and the combination did not show synergistic inhibitory effect. Vitamin K₂ alone tended to suppress the secretion of IL-17, IFN-γ, and TNF-α from the activated PBMCs of RA patients with smaller influences on the cytokine productions from healthy PBMCs. These additional effects of vitamin K₂ were also observed in combination with MTX.

CONCLUSION

The above information may partially elucidate the potentiation effects of vitamin K₂ on the immunosuppressive efficacy of MTX.

Vitamin K2 Suppresses Proliferation and Inflammatory Cytokine Production in Mitogen-Activated Lymphocytes of Atopic Dermatitis Patients through the Inhibition of Mitogen-Activated Protein Kinases

Vitamin K2 is suggested to have a suppressive effect on the peripheral blood mononuclear cells (PBMCs) of pediatric atopic dermatitis patients. We examined the molecular targets of vitamin K2 to suppress proliferation and cytokine production in T-cell mitogen-activated PBMCs of atopic dermatitis patients from the viewpoint of mitogen-activated protein kinase signaling molecules. The study population included 16 pediatric vitamin K2 patients and 21 healthy subjects. The effect of vitamin K2 on concanavalin A-activated PBMC proliferation was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and cell counting assays. T-helper (Th)1/Th2/Th17 cytokine profiles in plasma and PBMC-culture supernatants were analyzed by a cytometric beads array assay. Mitogen-activated protein kinase signaling molecules in concanavalin A-activated PBMCs were examined by enzyme-linked immunosorbent assay (ELISA) assays. At 10-100 µM, vitamin K2 significantly suppressed the proliferation of mitogen-activated PBMCs derived from atopic dermatitis patients and healthy subjects (p < 0.05). The interleukin (IL)-10 concentrations in plasma and the PBMC culture supernatants of atopic dermatitis patients were significantly higher than those of healthy subjects (p < 0.05). The IL-2 concentrations in the culture supernatants of atopic dermatitis PBMCs were significantly lower than those of healthy PBMCs (p < 0.05). Vitamin K2 significantly inhibited the IL-17A, IL-10, and tumor necrosis factor α (TNF-α) production (p < 0.05), and increased the IL-2 production (p < 0.01) in the culture supernatant of atopic dermatitis PBMCs. At 10-100 µM, vitamin K2 markedly decreased the of Mek1, extracellular signal-regulated kinases (ERK)1/2 mitogen-activated protein kinase, and SAPK/c-Jun N-terminal kinase (JNK) expression in atopic dermatitis PBMCs (p < 0.05). Vitamin K2 is suggested to attenuate activated T-cell immunity in atopic dermatitis patients through the inhibition of mitogen-activated protein kinase-Mek1-ERK1/2 and SAPK/JNK signaling pathways.

Effects of sinomenine on the proliferation, cytokine production, and regulatory T-cell frequency in peripheral blood mononuclear cells of rheumatoid arthritis patients

Sinomenine (SN) is a plant-derived alkaloid isolated from Caulis Sinomenii. It has been approved by the State Food and Drug Administration of China for treating rheumatoid arthritis (RA) nearly 20 years ago. To investigate the anti-RA mechanism of SN, a lot of scholars reported the immunosuppressive effect of SN on T lymphocytes. We continued to evaluate the suppressive function of SN by using human peripheral blood mononuclear cells (PBMCs) isolated from RA patients. As the positive control, 10 ng/ml of methylprednisolone (MP) showed the antiproliferation effect on mitogen-activated PBMCs of RA patients significantly (*p < .05). Meanwhile, MP decreased the frequency of CD4⁺ CD25⁺ T cells and suppressed the secretion of inflammatory Th1/Th2/Th17 cytokines such as IL-4, IL-6, IL-10, IL-17, IFN-γ, and TNF-α. However, SN at concentrations of 0.3-30 μM, showed little suppressive effects on the proliferation of PBMCs of RA patients. We did not observe any suppressive effects of SN on percentages of CD4⁺ T cells and CD4⁺ CD25⁺ T cells in the mitogen-activated PBMCs of RA patients. The influence of SN on the percentage of CD4⁺ CD25⁺ Foxp3⁺ T cells was also limited. Finally, even 30 μM of SN did not influence the secretion of Th1/Th2/Th17 cytokine significantly. The present study provided evidence that anti-RA mechanism of SN seems not to be related with the suppressive effects on peripheral T cells.

Cytotoxic effects of vitamins K1, K2, and K3 against human T lymphoblastoid leukemia cells through apoptosis induction and cell cycle arrest

The present study was undertaken to evaluate cytotoxic effects of vitamin K1 (phylloquinone), vitamin K2 (menaquinones), and vitamin K3 (menadione) against human T lymphoblastoid leukemia cells, Jurkat T cells, MOLT-4 cells, and P-glycoprotein-expressing multidrug-resistant MOLT-4/DNR cells. Vitamins K2 and K3, but not vitamin K1, reduced viabilities of Jurkat, MOLT-4, and MOLT-4/DNR cells. The influence potency of vitamin K3 was larger than that of vitamin K2 in all of the three cell lines. MOLT-4/DNR cells seemed to be more sensitive toward the effects of vitamins K2 and K3. The cytotoxicity of vitamins K2 and K3 on these leukemia cells seems to be related to apoptosis induction and cell cycle arrest. Vitamin K2 and K3 treatment induced cleavage of PARP obviously. Moreover, vitamins K2 and K3 specifically down-regulated the expressions of cyclin A2 in all of the three cell lines. However, the effects of vitamins K2 and K3 on the cell cycle profiling in Jurkat, MOLT-4, and MOLT-4/DNR cells varied with the cell type. Vitamins K2 and K3 also decreased the viability of mitogen-activated human peripheral blood mononuclear cells. Our observations suggest that vitamins K2 and K3 have bilateral cytotoxic effects on activated human peripheral lymphocytes and the human leukemic T cells.

Nutritional Modulation of Immune and Central Nervous System Homeostasis: The Role of Diet in Development of Neuroinflammation and Neurological Disease

The gut-microbiome-brain axis is now recognized as an essential part in the regulation of systemic metabolism and homeostasis. Accumulating evidence has demonstrated that dietary patterns can influence the development of metabolic alterations and inflammation through the effects of nutrients on a multitude of variables, including microbiome composition, release of microbial products, gastrointestinal signaling molecules, and neurotransmitters. These signaling molecules are, in turn, implicated in the regulation of the immune system, either promoting or inhibiting the production of pro-inflammatory cytokines and the expansion of specific leukocyte subpopulations, such as Th17 and Treg cells, which are relevant in the development of neuroinflammatory and neurodegenerative conditions. Metabolic diseases, like obesity and type 2 diabetes mellitus, are related to inadequate dietary patterns and promote variations in the aforementioned signaling pathways in patients with these conditions, which have been linked to alterations in neurological functions and mental health. Thus, maintenance of adequate dietary patterns should be an essential component of any strategy aiming to prevent neurological pathologies derived from systemic metabolic alterations. The present review summarizes current knowledge on the role of nutrition in the modulation of the immune system and its impact in the development of neuroinflammation and neurological disease.

Vitamin K: Double Bonds beyond Coagulation Insights into Differences between Vitamin K1 and K2 in Health and Disease

Vitamin K is an essential bioactive compound required for optimal body function. Vitamin K can be present in various isoforms, distinguishable by two main structures, namely, phylloquinone (K1) and menaquinones (K2). The difference in structure between K1 and K2 is seen in different absorption rates, tissue distribution, and bioavailability. Although differing in structure, both act as cofactor for the enzyme gamma-glutamylcarboxylase, encompassing both hepatic and extrahepatic activity. Only carboxylated proteins are active and promote a health profile like hemostasis. Furthermore, vitamin K2 in the form of MK-7 has been shown to be a bioactive compound in regulating osteoporosis, atherosclerosis, cancer and inflammatory diseases without risk of negative side effects or overdosing. This review is the first to highlight differences between isoforms vitamin K1 and K2 by means of source, function, and extrahepatic activity.