Gla-rich protein is involved in the cross-talk between calcification and inflammation in osteoarthritis

Effects of radical scavengers for reactive oxygen species on vitamin K-induced phototoxicity under UVA irradiation

Vitamin K possesses efficacy as a topical dermatological agent. However, vitamin K is phototoxic and susceptible to photodegradation. Herein, we investigated the mechanisms underlying the phototoxicity of phylloquinone (PK, vitamin K1) and menaquinone-4 (MK-4, vitamin K2) under ultraviolet A (UVA) irradiation using various reactive oxygen species (ROS) scavengers. This resulted in the production of superoxide anion radicals via type I and singlet oxygen via type II photodynamic reactions, which were quenched by the ROS scavengers: superoxide dismutase and sodium azide (NaN3). In HaCaT cells, MK-4 and PK induced the production of intracellular ROS, particularly hydrogen peroxide, in response to UVA irradiation. Furthermore, the addition of catalase successfully decreased maximum ROS levels by approximately 30%. NaN3 and catalase decreased the maximum reduction in cell viability induced by UVA-irradiated PK and MK-4 in cell viability by approximately 2-7-fold. Additionally, ROS scavengers had no effect on the photodegradation of PK or MK-4 at 373 nm. Therefore, the phototoxicities of PK and MK-4 were attributed to the generation of singlet oxygen and hydrogen peroxide, underscoring the importance of photoshielding in circumventing phototoxicity.

Menahydroquinone-4 may play a key role in regulating CCL5 expression induced by epidermal growth factor receptor inhibitors

Epidermal growth factor receptor (EGFR) inhibitors frequently cause severe skin rash as a side effect, which is a critical burden for patients who continuously receive drug treatments. Several recent clinical trials have shown that vitamin K is effective against these side effects; however, the underlying mechanisms remain unclear. EGFR inhibitors induce C-C motif chemokine ligand 5 (CCL5) in dermopathy. We hypothesized that menahydroquinone-4 (MKH), the active form of menaquinone-4 (MK-4, vitamin K2(20)), supplied by biosynthesis or external delivery, is essential for the suppressive effect on CCL5. The aim of this study was to explore the underlying mechanisms governing the relieving effects of MKH against skin rashes caused by EGFR inhibitors. The responses generated by EGFR inhibitors and the effect of MKH derivatives (two ester derivatives and MK-4) on them were evaluated using human skin cell lines (HaCaT and HSC-1). EGFR inhibitors downregulated UbiA prenyltransferase domain-containing protein-1 (UBIAD1, MKH synthetase) expression and MKH biosynthesis. Knockdown of UBIAD1 or γ-glutamyl carboxylase and treatment with warfarin upregulated CCL5 expression. MKH derivatives suppressed the CCL5 expression induced by EGFR inhibitors. Our data strongly suggest that MKH is involved in suppressing CCL5 expression and alleviating the skin damage caused by EGFR inhibitors.

An Exploratory Case-Control Study on the Associations of Bacterially-Derived Vitamin K Forms with the Intestinal Microbiome and Obesity-Related Osteoarthritis

Background

Evidence suggests that natural metabolites produced by intestinal microorganisms may have beneficial or harmful effects on osteoarthritis (OA). This could include menaquinones, which are bacterially-synthesized, biologically-active vitamin K forms abundant in the intestinal microbiome.

Objectives

The overall goal of this study was to evaluate the association of intestinally-derived menaquinones with obesity-related OA.

Methods

This case-control study used data and biospecimens derived from a subgroup of Johnston County Osteoarthritis Study participants. Fecal menaquinone concentrations and microbial composition were determined in 52 obese participants with hand and knee OA and 42 age- and sex-matched obese participants without OA. The inter-relationships among fecal menaquinones were evaluated using principal component analysis. The differences in alpha and beta diversities and microbial composition across menaquinone clusters were evaluated using ANOVA.

Results

The samples were clustered into the following 3 groups: cluster 1 characterized by higher fecal menaquinone-9 and -10 concentrations, cluster 2 characterized by lower overall menaquinone concentrations, and cluster 3 characterized by higher menaquinone-12 and -13 concentrations. Overall, fecal menaquinone clusters did not differ between participants with or without OA (P = 0.707). Microbial diversity did not differ across the fecal menaquinone clusters (all F-test P > 0.12). However, the relative abundance of bacterial taxa differed among clusters, with higher abundance of Coprococcus, Prevotella, and Eggerthella in cluster 2 than in cluster 1; higher abundance of Oscillospira, Dorea, Eubacterium, and Bacteroides in cluster 3 than in cluster 1; and higher abundance of Prevotella, Sutterella, and Dorea in cluster 3 than in cluster 2 (all P < 0.001).

Conclusion

Menaquinones were variable and abundant in the human gut, but the fecal menaquinone clusters did not differ with OA status. Although the relative abundance of specific bacterial taxa differed among fecal menaquinone clusters, the relevance of these differences with respect to vitamin K status and human health is uncertain.

New insights in osteoarthritis diagnosis and treatment: Nano-strategies for an improved disease management

Osteoarthritis (OA) is a common chronic joint pathology that has become a predominant cause of disability worldwide. Even though the origin and evolution of OA rely on different factors that are not yet elucidated nor understood, the development of novel strategies to treat OA has emerged in the last years. Cartilage degradation is the main hallmark of the pathology though alterations in bone and synovial inflammation, among other comorbidities, are also involved during OA progression. From a molecular point of view, a vast amount of signaling pathways are implicated in the progression of the disease, opening up a wide plethora of targets to attenuate or even halt OA. The main purpose of this review is to shed light on the recent strategies published based on nanotechnology for the early diagnosis of the disease as well as the most promising nano-enabling therapeutic approaches validated in preclinical models. To address the clinical issue, the key pathways involved in OA initiation and progression are described as the main potential targets for OA prevention and early treatment. Furthermore, an overview of current therapeutic strategies is depicted. Finally, to solve the drawbacks of current treatments, nanobiomedicine has shown demonstrated benefits when using drug delivery systems compared with the administration of the equivalent doses of the free drugs and the potential of disease-modifying OA drugs when using nanosystems. We anticipate that the development of smart and specific bioresponsive and biocompatible nanosystems will provide a solid and promising basis for effective OA early diagnosis and treatment. This article is categorized under: Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement.

Cartilage calcification in osteoarthritis: mechanisms and clinical relevance

Pathological calcification of cartilage is a hallmark of osteoarthritis (OA). Calcification can be observed both at the cartilage surface and in its deeper layers. The formation of calcium-containing crystals, typically basic calcium phosphate (BCP) and calcium pyrophosphate dihydrate (CPP) crystals, is an active, highly regulated and complex biological process that is initiated by chondrocytes and modified by genetic factors, dysregulated mitophagy or apoptosis, inflammation and the activation of specific cellular-signalling pathways. The links between OA and BCP deposition are stronger than those observed between OA and CPP deposition. Here, we review the molecular processes involved in cartilage calcification in OA and summarize the effects of calcium crystals on chondrocytes, synovial fibroblasts, macrophages and bone cells. Finally, we highlight therapeutic pathways leading to decreased joint calcification and potential new drugs that could treat not only OA but also other diseases associated with pathological calcification.

Relationship Amongst Vitamin K Status, Vitamin K Antagonist Use and Osteoarthritis: A Review

Vitamin K is essential for the carboxylation of the vitamin K-dependent proteins that are responsible for the suppression of matrix calcification. The use of vitamin K antagonists (VKAs) in patients with cardiovascular diseases could affect protein carboxylation and lead to the development of osteoarthritis (OA). This review aims to summarise the current evidence for the relationship between VKAs and OA. The literature search revealed that in observation studies, good vitamin K status, as reflected by the circulating level or protein carboxylation status of vitamin K, is associated positively with improved joint structural and functional indices and negatively associated with OA incidence. By contrast, in limited retrospective and prospective studies, the use of VKAs is associated positively with OA occurrence and knee/hip replacement. Pharmacological interactions between VKAs and various OA therapeutic agents exist and require careful monitoring and dosing. In conclusion, further epidemiological studies are warranted to verify the relationship between VKA use and OA to strengthen the evidence. Given that VKA use exerts potentially negative effects on joint health, intervention is required to protect the quality of life and mobility of patients.

Nanoencapsulation of Gla-Rich Protein (GRP) as a Novel Approach to Target Inflammation

Chronic inflammation is a major driver of chronic inflammatory diseases (CIDs), with a tremendous impact worldwide. Besides its function as a pathological calcification inhibitor, vitamin K-dependent protein Gla-rich protein (GRP) was shown to act as an anti-inflammatory agent independently of its gamma-carboxylation status. Although GRP’s therapeutic potential has been highlighted, its low solubility at physiological pH still constitutes a major challenge for its biomedical application. In this work, we produced fluorescein-labeled chitosan-tripolyphosphate nanoparticles containing non-carboxylated GRP (ucGRP) (FCNG) via ionotropic gelation, increasing its bioavailability, stability, and anti-inflammatory potential. The results indicate the nanosized nature of FCNG with PDI and a zeta potential suitable for biomedical applications. FCNG’s anti-inflammatory activity was studied in macrophage-differentiated THP1 cells, and in primary vascular smooth muscle cells and chondrocytes, inflamed with LPS, TNFα and IL-1β, respectively. In all these in vitro human cell systems, FCNG treatments resulted in increased intra and extracellular GRP levels, and decreased pro-inflammatory responses of target cells, by decreasing pro-inflammatory cytokines and inflammation mediators. These results suggest the retained anti-inflammatory bioactivity of ucGRP in FCNG, strengthening the potential use of ucGRP as an anti-inflammatory agent with a wide spectrum of application, and opening up perspectives for its therapeutic application in CIDs.

The Role of GRP and MGP in the Development of Non-Hemorrhagic VKCFD1 Phenotypes

Vitamin K dependent coagulation factor deficiency type 1 (VKCFD1) is a rare hereditary bleeding disorder caused by mutations in γ-Glutamyl carboxylase (GGCX) gene. The GGCX enzyme catalyzes the γ-carboxylation of 15 different vitamin K dependent (VKD) proteins, which have function in blood coagulation, calcification, and cell signaling. Therefore, in addition to bleedings, some VKCFD1 patients develop diverse non-hemorrhagic phenotypes such as skin hyper-laxity, skeletal dysmorphologies, and/or cardiac defects. Recent studies showed that GGCX mutations differentially effect γ-carboxylation of VKD proteins, where clotting factors are sufficiently γ-carboxylated, but not certain non-hemostatic VKD proteins. This could be one reason for the development of diverse phenotypes. The major manifestation of non-hemorrhagic phenotypes in VKCFD1 patients are mineralization defects. Therefore, the mechanism of regulation of calcification by specific VKD proteins as matrix Gla protein (MGP) and Gla-rich protein (GRP) in physiological and pathological conditions is of high interest. This will also help to understand the patho-mechanism of VKCFD1 phenotypes and to deduce new treatment strategies. In the present review article, we have summarized the recent findings on the function of GRP and MGP and how these proteins influence the development of non-hemorrhagic phenotypes in VKCFD1 patients.

Vitamin K - sources, physiological role, kinetics, deficiency, detection, therapeutic use, and toxicity

Vitamin K is traditionally connected with blood coagulation, since it is needed for the posttranslational modification of 7 proteins involved in this cascade. However, it is also involved in the maturation of another 11 or 12 proteins that play different roles, encompassing in particular the modulation of the calcification of connective tissues. Since this process is physiologically needed in bones, but is pathological in arteries, a great deal of research has been devoted to finding a possible link between vitamin K and the prevention of osteoporosis and cardiovascular diseases. Unfortunately, the current knowledge does not allow us to make a decisive conclusion about such a link. One possible explanation for this is the diversity of the biological activity of vitamin K, which is not a single compound but a general term covering natural plant and animal forms of vitamin K (K₁ and K₂) as well as their synthetic congeners (K₃ and K₄). Vitamin K₁ (phylloquinone) is found in several vegetables. Menaquinones (MK₄–MK₁₃, a series of compounds known as vitamin K₂) are mostly of a bacterial origin and are introduced into the human diet mainly through fermented cheeses. Current knowledge about the kinetics of different forms of vitamin K, their detection, and their toxicity are discussed in this review.

The Relationship Between Carotid Intima Media Thickness, Inflammation and GLA Rich Protein Levels in Chronic Kidney Disease

AIM

Vascular calcification is a common complication in CKD. Studies conducted in patients with end-stage renal disease (ESRD) showed that calcification in vascular structures is an important component of the atherosclerosis process. GLA rich protein (GRP) has been suggested as a potential marker for vascular calcification. We investigated the relationship between GRP levels, carotid intima media thickness and inflammatory parameters in patients with predialysis stage 3, 4 and 5 CKD.

MATERIAL AND METHODS

A total of 106 patients aged ≥18 years with CKD stage 3, stage 4 and non-dialysis stage 5 and 25 healthy volunteers were enrolled in the study. Patients with obesity, uncontrolled hypertension, coronary artery disease, with active cancer or liver disease, malignant hematologic disorders, acute renal failure, acute or chronic infections were excluded. As the control group, healthy volunteers without any known illness, regular drug use, smoking, alcohol use, and obesity were recruited.

RESULTS

Patients were divided into two groups as those with CIMT below 0.90 mm and those with CIMT 0.90 mm and above. There was no significant difference between the two groups in terms of the presence of HT and DM. While the CRP values of the group with high CIMT were found to be significantly higher (p=0.005), the GLA rich protein levels of this group were found to be significantly higher (p=0.019).

CONCLUSION

In our study, it was determined that there was a positive correlation between GRP levels and CIMT in patients with predialysis CKD, and GRP levels were higher in patients with CIMT above 0.90 mm. These findings suggest that GRP levels can be used as a cardiovascular event biomarker in patients with CKD.

Vitamin K-Dependent Proteins in Skeletal Development and Disease

Vitamin K and Vitamin K-dependent proteins (VKDPs) are best known for their pivotal role in blood coagulation. Of the 14 VKPDs identified in humans to date, 6 play also important roles in skeletal biology and disease. Thus, osteocalcin, also termed bone Gla-protein, is the most abundant non-collagenous protein in bone. Matrix Gla protein and Ucma/GRP on the other hand are highly abundant in cartilage. Furthermore, periostin, protein S, and growth arrest specific 6 protein (GAS 6) are expressed in skeletal tissues. The roles for these VKDPs are diverse but include the control of calcification and turnover of bone and cartilage. Vitamin K plays an important role in osteoporosis and serum osteocalcin levels are recognized as a promising marker for osteoporosis. On the other hand, matrix Gla protein and Ucma/GRP are associated with osteoarthritis. This review focuses on the roles of these three VKDPs, osteocalcin, matrix Gla protein and Ucma/GRP, in skeletal development and disease but will also summarize the roles the other skeletal VKDPs (periostin, protein S and GAS6) in skeletal biology.

Exogenous Vitamins K Exert Anti-Inflammatory Effects Dissociated from Their Role as Substrates for Synthesis of Endogenous MK-4 in Murine Macrophages Cell Line

Vitamins K exert a range of activities that extend far beyond coagulation and include anti-inflammatory effects, but the mechanisms involved in anti-inflammatory action remain unclear. In the present study, we showed that various forms of exogenous vitamins-K1, K3, K2 (MK-4, MK-5, MK-6 and MK-7)-regulated a wide scope of inflammatory pathways in murine macrophages in vitro, including NOS-2, COX-2, cytokines and MMPs. Moreover, we demonstrated for the first time that macrophages are able to synthesise endogenous MK-4 on their own. Vitamins with shorter isoprenoid chains-K1, K3 and MK-5-exhibited stronger anti-inflammatory potential than vitamins with longer isoprenoid chains (MK-6 and MK-7) and simultaneously were preferably used as a substrate for MK-4 endogenous production. Most interesting, atorvastatin pretreatment inhibited endogenous MK-4 production but had no impact on the anti-inflammatory activity of vitamins K. In summary, our results demonstrate that macrophages are able to synthesise endogenous MK-4 using exogenous vitamins K, and statin inhibits this process. However, the anti-inflammatory effect of exogenous vitamins K was independent of endogenous MK-4 synthesis.

Role of emerging vitamin K‑dependent proteins: Growth arrest‑specific protein 6, Gla‑rich protein and periostin (Review)

Vitamin K-dependent proteins (VKDPs) are a group of proteins that need vitamin K to conduct carboxylation. Thus far, scholars have identified a total of 17 VKDPs in the human body. In this review, we summarize three important emerging VKDPs: Growth arrest-specific protein 6 (Gas 6), Gla-rich protein (GRP) and periostin in terms of their functions in physiological and pathological conditions. As examples, carboxylated Gas 6 and GRP effectively protect blood vessels from calcification, Gas 6 protects from acute kidney injury and is involved in chronic kidney disease, GRP contributes to bone homeostasis and delays the progression of osteoarthritis, and periostin is involved in all phases of fracture healing and assists myocardial regeneration in the early stages of myocardial infarction. However, periostin participates in the progression of cardiac fibrosis, idiopathic pulmonary fibrosis and airway remodeling of asthma. In addition, we discuss the relationship between vitamin K, VKDPs and cancer, and particularly the carboxylation state of VKDPs in cancer.

Amentadione from the Alga Cystoseira usneoides as a Novel Osteoarthritis Protective Agent in an Ex Vivo Co-Culture OA Model

Osteoarthritis (OA) remains a prevalent chronic disease without effective prevention and treatment. Amentadione (YP), a meroditerpenoid purified from the alga Cystoseira usneoides, has demonstrated anti-inflammatory activity. Here, we investigated the YP anti-osteoarthritic potential, by using a novel OA preclinical drug development pipeline designed to evaluate the anti-inflammatory and anti-mineralizing activities of potential OA-protective compounds. The workflow was based on in vitro primary cell cultures followed by human cartilage explants assays and a new OA co-culture model, combining cartilage explants with synoviocytes under interleukin-1β (IL-1β) or hydroxyapatite (HAP) stimulation. A combination of gene expression analysis and measurement of inflammatory mediators showed that the proposed model mimicked early disease stages, while YP counteracted inflammatory responses by downregulation of COX-2 and IL-6, improved cartilage homeostasis by downregulation of MMP3 and the chondrocytes hypertrophic differentiation factors Col10 and Runx2. Importantly, YP downregulated NF-κB gene expression and decreased phosphorylated IkBα/total IkBα ratio in chondrocytes. These results indicate the co-culture as a relevant pre-clinical OA model, and strongly suggest YP as a cartilage protective factor by inhibiting inflammatory, mineralizing, catabolic and differentiation processes during OA development, through inhibition of NF-κB signaling pathways, with high therapeutic potential.

Effects of Anti-vitamin k oral anticoagulants on bone and cardiovascular health

Vitamin K antagonist oral anticoagulants (VKAs) have been proven over 50 years to be highly effective and acceptably safe in many settings and are still used by millions of people worldwide. The main concern about the safety of VKAs regards the risk of bleeding, but there is accumulation evidence of their potentially negative effects beyond hemostasis. Indeed, VKAs impair the action of several Vitamin-K Dependent Proteins (VKDP), such as Bone Gla protein, Matrix Gla protein, Gas6 Protein, Periostin and Gla-Ric Protein, involved in bone and vascular metabolism, thus exerting a detrimental effect on bone and vascular health. Indeed, although the evidence regarding this issue is not compelling, it has been shown that VKAs use decreases bone mass density, increases the risk of bone fractures and accelerates the process of vascular and valvular calcification. Vascular calcification is a major concern in Chronic Kidney Disease (CKD) patients, also in absence of VKAs, because of mineral metabolism derangement, chronic inflammation and oxidative stress. Direct Oral AntiCoagulants (DOACs) do not affect VKDP involved in vascular and valvular calcification, and do not induce calcific valve degeneration in animal models, being a possible alternative to AVK for CKD patients. However, the efficacy and safety of DOACs in this population, suggested by some recent observations, requires confirmation by dedicated, randomized study. We reviewed here the effects of VKAs in bone and vascular health as compared to DOACs, in order to provide the physicians with some data useful to wisely choose the most suitable anticoagulant for every patient.

In vivo protective effects of upper zone of growth plate and cartilage matrix associated protein against cartilage degeneration in a monosodium iodoacetate induced osteoarthritis model

Osteoarthritis (OA) is a degenerative disease affecting the majority of over 65 year old people and characterized by cartilage degeneration, subchondral abnormal changes, and inflammation. Despite the enormous socioeconomic burden caused by OA, currently, there is no effective therapy against it. Upper zone of growth plate and cartilage matrix associated protein (UCMA) is a vitamin K dependent protein and has a critical role in pathophysiological conditions associated with bone and cartilage. However, there is no research on the protective role of intra-articular UCMA treatment in OA pathogenesis. Therefore, we aimed to investigate the potential therapeutic role of UCMA in an in vivo model of OA. We report for the first time that intra-articular UCMA injection ameliorated cartilage degeneration in a monosodium iodoacetate induced OA rat model. Furthermore, the OA-induced activation of nuclear factor kappa B and bone morphogenetic protein 2 signals was attenuated by UCMA. Our results indicated that UCMA decreased cartilage oligomeric matrix protein levels but did not affect interleukin 6, total antioxidant status, and total oxidant status levels in the serum. In conclusion, UCMA exhibited a therapeutic potential in the treatment of OA. This protective effect of UCMA is possibly achieved by reducing the aggrecanase activity and the production of inflammatory cytokines.

The Relationship between Vitamin K and Osteoarthritis: A Review of Current Evidence

Vitamin K is a cofactor of γ-glutamyl carboxylase, which plays an important role in the activation of γ-carboxyglutamate (gla)-containing proteins that negatively regulate calcification. Thus, vitamin K status might be associated with osteoarthritis (OA), in which cartilage calcification plays a role in the pathogenesis of the disease. This review collates the evidence on the relationship between vitamin K status (circulating or dietary intake level of vitamin K, or circulating uncarboxylated gla proteins) and OA from human observational studies and clinical trial, to examine its potential as an agent in preventing OA. The current literature generally agrees that a sufficient level of vitamin K is associated with a lower risk of OA and pathological joint features. However, evidence from clinical trials is limited. Mechanistic study shows that vitamin K activates matrix gla proteins that inhibit bone morphogenetic protein-mediated cartilage calcification. Gla-rich proteins also inhibit inflammatory cascade in monocytic cell lines, but this function might be independent of vitamin K-carboxylation. Although the current data are insufficient to establish the optimal dose of vitamin K to prevent OA, ensuring sufficient dietary intake seems to protect the elderly from OA.

Pathological calcification in osteoarthritis: an outcome or a disease initiator?

In the progression of osteoarthritis, pathological calcification in the affected joint is an important feature. The role of these crystallites in the pathogenesis and progression of osteoarthritis is controversial; it remains unclear whether they act as a disease initiator or are present as a result of joint damage. Recent studies reported that the molecular mechanisms regulating physiological calcification of skeletal tissues are similar to those regulating pathological or ectopic calcification of soft tissues. Pathological calcification takes place when the equilibrium is disrupted. Calcium phosphate crystallites are identified in most affected joints and the presence of these crystallites is closely correlated with the extent of joint destruction. These observations suggest that pathological calcification is most likely to be a disease initiator instead of an outcome of osteoarthritis progression. Inhibiting pathological crystallite deposition within joint tissues therefore represents a potential therapeutic target in the management of osteoarthritis.

Gla-Rich Protein (GRP) as an Early and Novel Marker of Vascular Calcification and Kidney Dysfunction in Diabetic Patients with CKD: A Pilot Cross-Sectional Study

Vascular calcification (VC) is one of the strongest predictors of cardiovascular risk in chronic kidney disease (CKD) patients. New diagnostic/prognostic tools are required for early detection of VC allowing interventional strategies. Gla-rich protein (GRP) is a cardiovascular calcification inhibitor, whose clinical utility is here highlighted. The present study explores, for the first time, correlations between levels of GRP in serum with CKD developmental stage, mineral metabolism markers, VC and pulse pressure (PP), in a cohort of 80 diabetic patients with mild to moderate CKD (stages 2–4). Spearman’s correlation analysis revealed a positive association of GRP serum levels with estimated glomerular filtration rate (eGFR) and α-Klotho, while a negative correlation with phosphate (P), fibroblast growth factor 23 (FGF-23), vascular calcification score (VCS), PP, calcium (x) phosphate (CaxP) and interleukin 6 (IL-6). Serum GRP levels were found to progressively decrease from stage 2 to stage 4 CKD. Multivariate analysis identified low levels of eGFR and GRP, and high levels of FGF-23 associated with both the VCS and PP. These results indicate an association between GRP, renal dysfunction and CKD-mineral and bone disorder. The relationship between low levels of GRP and vascular calcifications suggests a future, potential utility for GRP as an early marker of vascular damage in CKD.

Vitamin K as a Diet Supplement with Impact in Human Health: Current Evidence in Age-Related Diseases

Vitamin K health benefits have been recently widely shown to extend beyond blood homeostasis and implicated in chronic low-grade inflammatory diseases such as cardiovascular disease, osteoarthritis, dementia, cognitive impairment, mobility disability, and frailty. Novel and more efficient nutritional and therapeutic options are urgently needed to lower the burden and the associated health care costs of these age-related diseases. Naturally occurring vitamin K comprise the phylloquinone (vitamin K1), and a series of menaquinones broadly designated as vitamin K2 that differ in source, absorption rates, tissue distribution, bioavailability, and target activity. Although vitamin K1 and K2 sources are mainly dietary, consumer preference for diet supplements is growing, especially when derived from marine resources. The aim of this review is to update the reader regarding the specific contribution and effect of each K1 and K2 vitamers in human health, identify potential methods for its sustainable and cost-efficient production, and novel natural sources of vitamin K and formulations to improve absorption and bioavailability. This new information will contribute to foster the use of vitamin K as a health-promoting supplement, which meets the increasing consumer demand. Simultaneously, relevant information on the clinical context and direct health consequences of vitamin K deficiency focusing in aging and age-related diseases will be discussed.

Vitamin K as a Powerful Micronutrient in Aging and Age-Related Diseases: Pros and Cons from Clinical Studies

Vitamin K is a multifunctional micronutrient implicated in age-related diseases such as cardiovascular diseases, osteoarthritis and osteoporosis. Although vitamin K-dependent proteins (VKDPs) are described to have a crucial role in the pathogenesis of these diseases, novel roles have emerged for vitamin K, independently of its role in VKDPs carboxylation. Vitamin K has been shown to act as an anti-inflammatory by suppressing nuclear factor κB (NF-κB) signal transduction and to exert a protective effect against oxidative stress by blocking the generation of reactive oxygen species. Available clinical evidences indicate that a high vitamin K status can exert a protective role in the inflammatory and mineralization processes associated with the onset and progression of age-related diseases. Also, vitamin K involvement as a protective super-micronutrient in aging and ‘inflammaging’ is arising, highlighting its future use in clinical practice. In this review we summarize current knowledge regarding clinical data on vitamin K in skeletal and cardiovascular health, and discuss the potential of vitamin K supplementation as a health benefit. We describe the clinical evidence and explore molecular aspects of vitamin K protective role in aging and age-related diseases, and its involvement as a modulator in the interplay between pathological calcification and inflammation processes.

Association of UCMA levels in serum and synovial fluid with severity of knee osteoarthritis

AIM

Osteoarthritis (OA) is one of the most common joint diseases causing physical disability in the aged population. OA pathogenesis is not fully known and yet there are no effective therapeutic options against OA. Upper Zone of Growth Plate and Cartilage Matrix Associated (UCMA) is a member of vitamin K-dependent protein family, and is involved in inflammation, cardiovascular diseases, cancer, and OA. In the present study, our aim was to detect serum and synovial fluid (SF) levels of UCMA and to analyze their correlation with radiographic findings and symptomatic severity in OA patients as well as the correlation between oxidative stress levels and SF UCMA levels.

METHODS

Forty OA patients with cartilage degeneration and 20 patients with other knee joint disorders (non-OA control) were included in the present study. We used the Kellgren-Lawrence (KL) classification and Western Ontario McMaster University Osteoarthritis Index (WOMAC) scores to assess radiographic grading and symptomatic severity of OA, respectively. UCMA levels were measured in SF and serum. And also oxidative stress markers were analyzed in SF.

RESULTS

SF UCMA levels of OA patients were higher compared to those of the non-OA control group and were positively correlated with radiographic finding and symptomatic severity of OA. However, there was no significant correlation between oxidative markers of SF and the KL grade, WOMAC scores, and SF UCMA levels in OA patients.

CONCLUSION

There is a close connection between UCMA SF levels and symptomatic and radiographic severities of knee OA. Therefore, UCMA can be a promising biomarker in the diagnosis and/or prognosis of OA disease.

The interplay between mineral metabolism, vascular calcification and inflammation in Chronic Kidney Disease (CKD): challenging old concepts with new facts

Chronic kidney disease (CKD) is one of the most powerful predictors of premature cardiovascular disease (CVD), with heightened susceptibility to vascular intimal and medial calcification associated with a high cardiovascular mortality. Abnormal mineral metabolism of calcium (Ca) and phosphate (P) and underlying (dys)regulated hormonal control in CKD-mineral and bone disorder (MBD) is often accompanied by bone loss and increased vascular calcification (VC). While VC is known to be a multifactorial process and a major risk factor for CVD, the view of primary triggers and molecular mechanisms complexity has been shifting with novel scientific knowledge over the last years. In this review we highlight the importance of calcium-phosphate (CaP) mineral crystals in VC with an integrated view over the complexity of CKD, while discuss past and recent literature aiming to highlight novel horizons on this major health burden. Exacerbated VC in CKD patients might result from several interconnected mechanisms involving abnormal mineral metabolism, dysregulation of endogenous calcification inhibitors and inflammatory pathways, which function in a feedback loop driving disease progression and cardiovascular outcomes. We propose that novel approaches targeting simultaneously VC and inflammation might represent valuable new prognostic tools and targets for therapeutics and management of cardiovascular risk in the CKD population.

Vitamin K Dependent Proteins in Kidney Disease

Patients with chronic kidney disease (CKD) have an increased risk of developing vascular calcifications, as well as bone dynamics impairment, leading to a poor quality of life and increased mortality. Certain vitamin K dependent proteins (VKDPs) act mainly as calcification inhibitors, but their involvement in the onset and progression of CKD are not completely elucidated. This review is an update of the current state of knowledge about the relationship between CKD and four extrahepatic VKDPs: matrix Gla protein, osteocalcin, growth-arrest specific protein 6 and Gla-rich protein. Based on published literature in the last ten years, the purpose of this review is to address fundamental aspects about the link between CKD and circulating VKDPs levels as well as to raise new topics about how the interplay between molecular weight and charge could influence the modifications of circulating VKDPs at the glomerular level, or whether distinct renal etiologies have effect on VKDPs. This review is the output of a systematic literature search and may open future research avenues in this niche domain.

Basic calcium phosphate crystal-associated musculoskeletal syndromes: an update

PURPOSE OF REVIEW

Basic calcium phosphate (BCP) crystals are associated with two important musculoskeletal syndromes. Deposition of BCP crystals in tendons, bursae, and other soft tissues around joints causes calcific periarthritis, whereas intra-articular BCP crystals contribute to osteoarthritis and cause the highly destructive arthritis known as Milwaukee Shoulder Syndrome. The epidemiology and natural history of these syndromes are poorly understood, and because the pathogenesis remains unclear, few targeted therapies are available. I will review new developments in this field.

RECENT FINDINGS

I will discuss a case collection of calcific periarthritis of the hip, and evidence-based management strategies for shoulder calcific periarthritis that might be applied to calcific periarthritis at other locations. I will summarize several recent articles addressing mechanisms of crystal formation and identifying pathways through which BCP crystals produce tissue damage and explore some newly identified risk factors for pathologic mineralization.

SUMMARY

We are making slow, but steady progress in understanding the clinical presentation of calcific periarthritis in sites other than the shoulder. A growing appreciation of the mechanisms through which BCP crystals mediate tissue damage should lead to the development of novel management strategies for these common musculoskeletal syndromes.

Sinomenine Inhibits the Progression of Rheumatoid Arthritis by Regulating the Secretion of Inflammatory Cytokines and Monocyte/Macrophage Subsets

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory arthropathy associated with articular damage and attendant comorbidities. Even although RA treatment has advanced remarkably over the last decade, a significant proportion of patients still do not achieve sustained remission. The cause of RA is not yet known despite the many potential mechanisms proposed. It has been confirmed that RA is associated with dysregulated immune system and persistent inflammation. Therefore, management of inflammation is always the target of therapy. Sinomenine (SIN) is the prescription drug approved by the Chinese government for RA treatment. A previous study found that SIN was a robust anti-inflammation drug. In this study, we screened the different secretory cytokines using inflammation antibody arrays and qRT-PCR in both LPS-induced and SIN-treated RAW264.7 cells followed by evaluation of the ability of SIN to modulate cytokine secretion in a cell model, collagen-induced arthritis (CIA) mouse model, and RA patients. Several clinical indexes affecting the 28-joint disease activity score (DAS28) were determined before and after SIN treatment. Clinical indexes, inflammatory cytokine secretion, and DAS28 were compared among RA patients treated with either SIN or methotrexate (MTX). To explore the mechanism of SIN anti-inflammatory function, RA-associated monocyte/macrophage subsets were determined using flow cytometry in CIA mouse model and RA patients, both treated with SIN. The results demonstrated that SIN regulated IL-6, GM-CSF, IL-12 p40, IL-1α, TNF-α, IL-1β, KC (CXCL1), Eotaxin-2, IL-10, M-CSF, RANTES, and MCP-1 secretion in vivo and in vitro and reduced RA activity and DAS28 in a clinical setting. Furthermore, SIN attenuated CD11b⁺F4/80⁺CD64⁺ resident macrophages in the synovial tissue, CD11b⁺Ly6C⁺CD43⁺ macrophages in the spleen and draining lymph nodes of CIA mice. The percentage of CD14⁺CD16⁺ peripheral blood mononuclear cells was reduced by SIN in RA patients. These data indicated that SIN regulates the secretion of multiple inflammatory cytokines and monocyte/macrophage subsets, thereby suppressing RA progression. Therefore, along with MTX, SIN could be an alternative cost-effective anti-inflammatory agent for treating RA.

Mesenchymal stromal cells-derived matrix Gla protein contribute to the alleviation of experimental colitis

Crohn's disease (CD) is a chronic inflammatory bowel disease that is difficult to treat. However, previous preclinical and clinical studies have shown that mesenchymal stromal cells (MSCs) are a promising therapeutic approach, whereas the exact underlying molecular mechanisms of MSCs in treating CD remain unclear. Furthermore, the heterogeneity of MSCs, as well as the in vivo microenvironments may influence the therapeutic efficacy. In our previous study, we found that a subpopulation of mouse MSCs with a high expression of matrix Gla protein (MGP), one of the members of vitamin K-dependent protein family, possessed better immunoregulatory properties. Therefore, in this study we investigate whether the abundant MSCs-derived MGP participate in the therapeutic mechanisms for MSCs treating CD. Obvious suppression of cell proliferation and cytokine production in T cells were observed in vitro through MSCs-derived MGP. Moreover, MGP alleviated the clinical and histopathological severity of colonic inflammation in mouse experimental colitis models to a remarkable degree. Our results indicate that MGP might be a novel important mediator of MSCs-mediated immunomodulation in treating CD.

Association of Vitamin K Status Combined With Vitamin D Status and Lower-Extremity Function: A Prospective Analysis of Two Knee Osteoarthritis Cohorts

OBJECTIVE

Vitamins K and D are important for the function of vitamin K-dependent proteins in joint tissues. It is unclear whether these nutrients are mutually important to functional outcomes related to knee osteoarthritis (OA). We evaluated the association of vitamin K and D sufficiency with lower-extremity function in the Health, Aging and Body Composition knee OA substudy (Health ABC) and conducted a replication analysis in an independent cohort, the Osteoarthritis Initiative (OAI).

METHODS

In Health ABC (60% female, mean ± SD age 75 ± 3 years) baseline nutrient status was measured using circulating vitamin K and 25-hydroxyvitamin D (25[OH]D). Lower-extremity function was assessed using the Short Physical Performance Battery (SPPB) and usual 20-meter gait speed. In the OAI (58% female, mean ± SD age 61 ± 9 years), baseline nutrient intake was estimated by food frequency questionnaire. Lower-extremity function was assessed using usual 20-meter gait speed and chair stand completion time. Multivariate mixed models were used to evaluate the association of vitamin K and D status and intake with lower-extremity function over 4-5 years.

RESULTS

Health ABC participants with sufficient plasma vitamin K (≥1.0 nmoles/liter) and serum 25(OH)D (≥50 nmoles/liter) generally had better SPPB scores and faster usual gait speed over followup (P ≤ 0.002). In the OAI, sufficient vitamin K and vitamin D intake combined was associated with overall faster usual gait speed and chair stand completion time over followup (P ≤ 0.029).

CONCLUSION

Sufficient vitamin K status combined with sufficient vitamin D status was associated with better lower-extremity function in 2 knee OA cohorts. These findings merit confirmation in vitamin K and D co-supplementation trials.

Upper zone of growth plate and cartilage matrix associated protein protects cartilage during inflammatory arthritis

Background

ADAMTS aggrecanases play a major role in cartilage degeneration during degenerative and inflammatory arthritis. The cartilage-specific secreted protein Upper zone of growth plate and cartilage matrix associated protein (Ucma) has been shown to block ADAMTS-triggered aggrecanolysis in experimental osteoarthritis. Here we aimed to investigate whether and how Ucma may affect cartilage destruction and osteophyte formation in the context of inflammatory arthritis.

Methods

Ucma–ADAMTS5 protein interactions were studied using slot blot and solid phase binding assays. Chondrocyte cultures were stimulated with ADAMTS5 or IL-1β in the presence or absence of Ucma and aggrecanolysis was assessed by neoepitope formation. Arthritis was induced by transfer of K/BxN serum into wild-type (WT), Ucma-deficient and WT mice treated with recombinant Ucma. Cartilage proteoglycan loss and cartilage damage was assessed by safranin-O stain, aggrecanase-induced neoepitope formation and histomorphometry, respectively. Osteophytes were assessed by histomorphometry, micro-computed tomography, RNA in-situ hybridisation for collagen10a1 and osteocalcin, and staining for TRAP activity. Gene expression analyses were performed using real-time RT-PCR.

Results

Ucma physically interacted with ADAMTS5 and blocked its aggrecanase activity in chondrocyte cultures. Ucma was highly expressed in the articular cartilage and in osteophytes during arthritis. Ucma had no effect on inflammation and bone erosion. In contrast, Ucma-deficient mice developed significantly more severe cartilage proteoglycan loss and cartilage destruction. Conversely, treatment with Ucma inhibited cartilage degeneration in arthritis. Ucma effectively inhibited ADAMTS5-triggered or IL-1β-triggered aggrecanolysis in vitro and in vivo. Furthermore, osteophyte formation was reduced in Ucma-deficient mice.

Conclusions

These results indicate that Ucma inhibits aggrecanolysis by physical interaction with ADAMTS5 and protects from cartilage degeneration in inflammatory arthritis. Ucma therefore represents an interesting novel and specific target for preventing cartilage degradation in the context of inflammatory arthritis.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1583-2) contains supplementary material, which is available to authorized users.

Vitamin K‑dependent proteins involved in bone and cardiovascular health (Review)

In postmenopausal women and elderly men, bone density decreases with age and vascular calcification is aggravated. This condition is closely associated with vitamin K2 deficiency. A total of 17 different vitamin K-dependent proteins have been identified to date. Vitamin K-dependent proteins are located within the bone, heart and blood vessels. For instance, carboxylated osteocalcin is beneficial for bone and aids the deposition of calcium into the bone matrix. Carboxylated matrix Gla protein effectively protects blood vessels and may prevent calcification within the vascular wall. Furthermore, carboxylated Gla-rich protein has been reported to act as an inhibitor in the calcification of the cardiovascular system, while growth arrest-specific protein-6 protects endothelial cells and vascular smooth muscle cells, resists apoptosis and inhibits the calcification of blood vessels by inhibiting the apoptosis of vascular smooth muscle cells. In addition, periostin may promote the differentiation, aggregation, adhesion and proliferation of osteoblasts. Periostin also occurs in the heart and may be associated with the reconstruction of heart function. These vitamin K-dependent proteins may exert their functions following γ-carboxylation with vitamin K, and different vitamin K-dependent proteins may exhibit synergistic effects or antagonistic effects on each other. In the cardiovascular system with vitamin K antagonist supplement or vitamin K deficiency, calcification occurs in the endothelium of blood vessels and vascular smooth muscle cells are transformed into osteoblast-like cells, a phenomenon that resembles bone growth. Both the bone and cardiovascular system are closely associated during embryonic development. Thus, the present study hypothesized that embryonic developmental position and tissue calcification may have a certain association for the bone and the cardiovascular system. This review describes and briefly discusses several important vitamin K-dependent proteins that serve an important role in bone and the cardiovascular system. The results of the review suggest that the vascular calcification and osteogenic differentiation of vascular smooth muscle cells may be associated with the location of the bone and cardiovascular system during embryonic development.

Recent Insights into the Contribution of the Changing Hypertrophic Chondrocyte Phenotype in the Development and Progression of Osteoarthritis

Osteoarthritis (OA) is an extremely prevalent age-related condition. The economic and societal burden due to the cost of symptomatic treatment, inability to work, joint replacement, and rehabilitation is huge and increasing. Currently, there are no effective medical therapies that delay or reverse the pathological manifestations of OA. Current treatment options are, without exception, focused on slowing down progression of the disease to postpone total joint replacement surgery for as long as possible and keeping the associated pain and joint immobility manageable. Alterations in the articular cartilage chondrocyte phenotype might be fundamental in the pathological mechanisms of OA development. In many ways, the changing chondrocyte phenotype in osteoarthritic cartilage resembles the process of endochondral ossification as seen, for instance, in developing growth plates. However, the relative contribution of endochondral ossification to the changing chondrocyte phenotype in the development and progression of OA remains poorly described. In this review, we will discuss the current knowledge regarding the cartilage endochondral phenotypic changes occurring during OA development and progression, as well as the molecular and environmental effectors driving these changes. Understanding how these molecular mechanisms determine the chondrocyte cell fate in OA will be essential in enabling cartilage regenerative approaches in future treatments of OA.

Implication of a novel vitamin K dependent protein, GRP/Ucma in the pathophysiological conditions associated with vascular and soft tissue calcification, osteoarthritis, inflammation, and carcinoma

Gla-rich protein (GRP) or unique cartilage matrix-associated protein (Ucma), the newest member of vitamin K dependent proteins, carries exceptionally high number of γ-carboxyglutamic acid (Gla) residues which contributes to its outstanding capacity of binding with calcium in the extracellular environment indicating its potential role as a global calcium modulator. Recent studies demonstrated a critical function of GRP in the regulation of different pathophysiological conditions associated with vascular and soft tissue calcification including cardiovascular diseases, osteoarthritis, inflammation, and skin and breast carcinomas. These findings established an important relationship between γ-carboxylation of GRP and calcification associated disease pathology suggesting a critical role of vitamin K in the pathophysiological features of various health disorders. This review for the first time summarizes all of the updated findings related to the functional activities of GRP in the pathogenesis of several diseases associated with vascular and soft tissue mineralization, osteoarthritis, inflammation, and carcinoma. The outcome of this review will improve the understanding about the role of GRP in the pathogenesis of tissue calcification and its associated health disorders, which should in turn lead to the design of clinical interventions to improve the condition of patients associated with these health disorders.

Chronic Kidney Disease Circulating Calciprotein Particles and Extracellular Vesicles Promote Vascular Calcification: A Role for GRP (Gla-Rich Protein)

OBJECTIVE

Inhibition of mineral crystal formation is a crucial step in ectopic calcification. Serum calciprotein particles (CPPs) have been linked to chronic kidney disease (CKD) calcification propensity, but additional knowledge is required to understand their function, assemblage, and composition. The role of other circulating nanostructures, such as extracellular vesicles (EVs) in vascular calcification is currently unknown. Here, we investigated the association of GRP (Gla-rich protein) with circulating CPP and EVs and the role of CKD CPPs and EVs in vascular calcification.

APPROACH AND RESULTS

Biological CPPs and EVs were isolated from healthy and CKD patients and comparatively characterized using ultrastructural, analytic, molecular, and immuno-based techniques. Our results show that GRP is a constitutive component of circulating CPPs and EVs. CKD stage 5 serum CPPs and EVs are characterized by lower levels of fetuin-A and GRP, and CPPs CKD stage 5 have increased mineral maturation, resembling secondary CPP particles. Vascular smooth muscle cell calcification assays reveal that CPPs CKD stage 5 and EVs CKD stage 5 are taken up by vascular smooth muscle cells and induce vascular calcification by promoting cell osteochondrogenic differentiation and inflammation. These effects were rescued by incubation of CPPs CKD stage 5 with γ-carboxylated GRP. In vitro, formation and maturation of basic calcium phosphate crystals was highly reduced in the presence of γ-carboxylated GRP, fetuin-A, and MGP (matrix gla protein), and a similar antimineralization system was identified in vivo.

CONCLUSIONS

Uremic CPPs and EVs are important players in the mechanisms of widespread calcification in CKD. We propose a major role for cGRP as inhibitory factor to prevent calcification at systemic and tissue levels.

Gla-rich protein function as an anti-inflammatory agent in monocytes/macrophages: Implications for calcification-related chronic inflammatory diseases

Calcification-related chronic inflammatory diseases are multifactorial pathological processes, involving a complex interplay between inflammation and calcification events in a positive feed-back loop driving disease progression. Gla-rich protein (GRP) is a vitamin K dependent protein (VKDP) shown to function as a calcification inhibitor in cardiovascular and articular tissues, and proposed as an anti-inflammatory agent in chondrocytes and synoviocytes, acting as a new crosstalk factor between these two interconnected events in osteoarthritis. However, a possible function of GRP in the immune system has never been studied. Here we focused our investigation in the involvement of GRP in the cell inflammatory response mechanisms, using a combination of freshly isolated human leucocytes and undifferentiated/differentiated THP-1 cell line. Our results demonstrate that VKDPs such as GRP and matrix gla protein (MGP) are synthesized and γ-carboxylated in the majority of human immune system cells either involved in innate or adaptive immune responses. Stimulation of THP-1 monocytes/macrophages with LPS or hydroxyapatite (HA) up-regulated GRP expression, and treatments with GRP or GRP-coated basic calcium phosphate crystals resulted in the down-regulation of mediators of inflammation and inflammatory cytokines, independently of the protein γ-carboxylation status. Moreover, overexpression of GRP in THP-1 cells rescued the inflammation induced by LPS and HA, by down-regulation of the proinflammatory cytokines TNFα, IL-1β and NFkB. Interestingly, GRP was detected at protein and mRNA levels in extracellular vesicles released by macrophages, which may act as vehicles for extracellular trafficking and release. Our data indicate GRP as an endogenous mediator of inflammatory responses acting as an anti-inflammatory agent in monocytes/macrophages. We propose that in a context of chronic inflammation and calcification-related pathologies, GRP might act as a novel molecular mediator linking inflammation and calcification events, with potential therapeutic application.

GGCX-Associated Phenotypes: An Overview in Search of Genotype-Phenotype Correlations

Gamma-carboxylation, performed by gamma-glutamyl carboxylase (GGCX), is an enzymatic process essential for activating vitamin K-dependent proteins (VKDP) with important functions in various biological processes. Mutations in the encoding GGCX gene are associated with multiple phenotypes, amongst which vitamin K-dependent coagulation factor deficiency (VKCFD1) is best known. Other patients have skin, eye, heart or bone manifestations. As genotype–phenotype correlations were never described, literature was systematically reviewed in search of patients with at least one GGCX mutation with a phenotypic description, resulting in a case series of 47 patients. Though this number was too low for statistically valid correlations—a frequent problem in orphan diseases—we demonstrate the crucial role of the horizontally transferred transmembrane domain in developing cardiac and bone manifestations. Moreover, natural history suggests ageing as the principal determinant to develop skin and eye symptoms. VKCFD1 symptoms seemed more severe in patients with both mutations in the same protein domain, though this could not be linked to a more perturbed coagulation factor function. Finally, distinct GGCX functional domains might be dedicated to carboxylation of very specific VKDP. In conclusion, this systematic review suggests that there indeed may be genotype–phenotype correlations for GGCX-related phenotypes, which can guide patient counseling and management.