Hepatic and Vascular Vitamin K Status in Patients with High Cardiovascular Risk

Research progress of protein induced by vitamin K absence or antagonist II in liver transplantation for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common pathologic type of primary liver cancer. Liver transplantation (LT) is a radical strategy for treating patients with early-stage HCC, which may lead to a better prognosis compared to hepatectomy and ablation. However, survival of patients who develop HCC recurrence after LT is short, and early recurrence is the most common cause of death. Thus, efficient biomarkers are also needed in LT to guide precision therapy to improve patient prognosis and 5-year survival. Protein induced by vitamin K absence or antagonist II (PIVKA-II) is an abnormal prothrombin that cannot activate coagulation, and it is significantly increased in patients with HCC, obstructive jaundice, and those taking vitamin K antagonists. Over the past decades, substantial progress has been made in the study of PIVKA-II in diagnosing, surveilling, and treating HCC, but its role in LT still needs to be elaborated. In this review, we focused on the role of PIVKA-II as a biomarker in LT for HCC, especially its relationship with clinicopathologic features, early recurrence, long-term survival, and donor-recipient selection.

New Cardiovascular Biomarkers in Breast Cancer Patients Undergoing Doxorubicin-Based Chemotherapy

BACKGROUND

Central Illustration : New Cardiovascular Biomarkers in Breast Cancer Patients Undergoing Doxorubicin-Based Chemotherapy. Cardiovascular diseases (CVDs) are relevant to the management of breast cancer treatment since a substantial number of patients develop these complications after chemotherapy.

OBJECTIVE

This study aims to evaluate new cardiovascular biomarkers, namely CXCL-16 (C-X-C motif ligand 16), FABP3 (fatty acid binding protein 3), FABP4 (fatty acid binding protein 4), LIGHT (tumor necrosis factor superfamily member 14/TNFS14), GDF-15 (Growth/differentiation factor 15), sCD4 (soluble form of CD14), and ucMGP (uncarboxylated Matrix Gla-Protein) in breast cancer patients treated with doxorubicin (DOXO).

METHODS

This case-control study was conducted in an oncology clinic that included 34 women diagnosed with breast cancer and chemotherapy with DOXO and 34 control women without cancer and CVD. The markers were determined immediately after the last cycle of chemotherapy. The statistical significance level adopted was 5%.

RESULTS

The breast cancer group presented higher levels of GDF-15 (p<0.001), while control subjects had higher levels of FABP3 (p=0.038), FABP4 (p=0003), sCD14, and ucMGP (p<0.001 for both). Positive correlations were observed between FABPs and BMI in the cancer group.

CONCLUSION

GDF15 is an emerging biomarker with potential clinical applicability in this scenario. FABPs are proteins related to adiposity, which are potentially involved in breast cancer biology. sCD14 and ucMGP engage in inflammatory and vascular calcification. The evaluation of these novel cardiovascular biomarkers could be useful in the management of breast cancer chemotherapy with DOXO.

Role of Vitamin K in Bone and Muscle Metabolism

Vitamin K, a cofactor for the γ-glutamyl carboxylase enzyme, is required for the post-translational activation of osteocalcin and matrix Gla protein, which play a key role in bone and muscle homeostasis. In vivo and in vitro models for osteoporosis and sarcopenia suggest the vitamin K could exert a positive effect in both conditions. In bone, it increases osteoblastogenesis, whilst decreases osteoclast formation and function. In muscle, it is associated with increased satellite cell proliferation and migration and might play a role in energy metabolism. Observational trials suggest that high levels of vitamin K are associated with increased bone mineral density and reduced fracture risk. However, interventional studies for vitamin K supplementation yielded conflicting results. Clinical trials in sarcopenia suggest that vitamin K supplementation could improve muscle mass and function. One of the main limitations on the vitamin K studies are the technical challenges to measure its levels in serum. Thus, they are obtained from indirect sources like food questionnaires, or levels of undercarboxylated proteins, which can be affected by other environmental or biological processes. Although current research appoints to a beneficial effect of vitamin K in bone and muscle, further studies overcoming the current limitations are required in order to incorporate this supplementation in the clinical management of patients with osteosarcopenia.

VItamin K In PEritonial DIAlysis (VIKIPEDIA): Rationale and study protocol for a randomized controlled trial

Vascular calcification (VC) is an active process, resulting from the disturbance of balance between inhibitors and promoters of calcification, in favor of the latter. Matrix Gla Protein, a powerful inhibitor of VC, needs vitamin K to become active. In vitamin K depletion, plasma levels of the inactive form of MGP, dephosphorylated, uncarboxylated MGP (dp-ucMGP) are increased and associated with VC and cardiovascular (CV) outcomes. End Stage Renal Disease (ESRD) patients have increased circulating dp-ucMGP levels and accelerated VC. VItamin K In PEritoneal DIAlysis (VIKIPEDIA) is a prospective, randomized, open label, placebo-controlled trial, evaluating the effect of vitamin K2 supplementation on arterial stiffness and CV events in ESRD patients undergoing peritoneal dialysis (PD). Forty-four PD patients will be included in the study. At baseline, dp-ucMGP and pulse-wave velocity (PWV) will be assessed and then patients will be randomized (1:1 ratio) to vitamin K (1000 μg MK-7/day) or placebo for 1.5 years. The primary endpoint of this trial is the change in PWV in the placebo group as compared to the treatment group. Secondary endpoints are the occurrence of CV events, mortality, changes in PD adequacy, change in 24-hour ambulatory blood pressure indexes and aortic systolic blood pressure and changes in calcium/phosphorus/parathormone metabolism. VIKIPEDIA is a new superiority randomized, open label, placebo-controlled trial aiming to determine the effect of vitamin K2 supplementation on VC, CV disease and calcium/phosphorus metabolism, in PD patients.

Trial registration: The protocol of this study is registered at ClinicalTrials.gov with identification number NCT04900610 (25 May 2021).

Editorial for the Special Issue “Vitamin K in Chronic Disease and Human Health”

Vitamin K and its derivatives represent a complex of fat-soluble vitamins, playing a major role in the regulation of a large number of physiologic processes required for optimal homeostasis [...]

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.