Diverse biological functions of vitamin K: from coagulation to ferroptosis

Targeting ferroptosis for treating kidney disease

Ferroptosis is a type of regulated cell death hallmarked by iron-mediated excessive lipid oxidation. Over the past decade since the coining of the term ferroptosis, advances in research have led to the identification of intracellular processes that regulate ferroptosis such as GSH-GPX4 pathway and FSP1-coenzyme Q10/vitamin K pathway. From a disease perspective, the involvement of ferroptosis in pathological conditions including kidney disease has attracted attention. In terms of renal pathophysiology, ferroptosis has been widely investigated for its involvement in ischemia-reperfusion injury, nephrotoxin-induced kidney damage and other renal diseases. Therefore, therapeutic interventions targeting ferroptosis are expected to become a new therapeutic approach for these diseases. However, when considering cell death as a therapeutic target, careful consideration must be given to (i) in which type of cells, (ii) which type of cell death mode, and (iii) in which stage or temporal window of the disease. In the next decade, elucidation of the true involvement of ferroptosis in kidney disease setting in human, and development of clinically applicable and effective therapeutic drugs that target ferroptosis are warranted.

Ferroptosis in health and disease

Ferroptosis is a pervasive non-apoptotic form of cell death highly relevant in various degenerative diseases and malignancies. The hallmark of ferroptosis is uncontrolled and overwhelming peroxidation of polyunsaturated fatty acids contained in membrane phospholipids, which eventually leads to rupture of the plasma membrane. Ferroptosis is unique in that it is essentially a spontaneous, uncatalyzed chemical process based on perturbed iron and redox homeostasis contributing to the cell death process, but that it is nonetheless modulated by many metabolic nodes that impinge on the cells' susceptibility to ferroptosis. Among the various nodes affecting ferroptosis sensitivity, several have emerged as promising candidates for pharmacological intervention, rendering ferroptosis-related proteins attractive targets for the treatment of numerous currently incurable diseases. Herein, the current members of a Germany-wide research consortium focusing on ferroptosis research, as well as key external experts in ferroptosis who have made seminal contributions to this rapidly growing and exciting field of research, have gathered to provide a comprehensive, state-of-the-art review on ferroptosis. Specific topics include: basic mechanisms, in vivo relevance, specialized methodologies, chemical and pharmacological tools, and the potential contribution of ferroptosis to disease etiopathology and progression. We hope that this article will not only provide established scientists and newcomers to the field with an overview of the multiple facets of ferroptosis, but also encourage additional efforts to characterize further molecular pathways modulating ferroptosis, with the ultimate goal to develop novel pharmacotherapies to tackle the various diseases associated with - or caused by - ferroptosis.

Mechanisms and therapeutic target of anti-tumour treatment-related Ferroptosis: How to improve cancer therapy?

Recently, increased attention has been focused on the regulatory mechanism and potential clinical application of ferroptosis in cancer cells, especially therapy-related ferroptosis. However, the mechanism of treatment-related ferroptosis and the application prospects and strategies for future treatment still require further clarification. This review highlights the molecular relationships between different clinical antitumour drugs, including commonly used chemotherapy drugs, radiation therapy and vitamins, and ferroptosis. This review also proposes strategies for future treatments that involve ferroptosis, with an aim to develop a new strategy for the transformative potential of the emerging field of ferroptosis to improve cancer therapy.

The investigation of connection between anticoagulant therapy and vitamin K homologues in human determined by LC-MS/MS

Aim: Differences are existed in the bioactivity among various vitamin K (VK) forms. To investigate the correlation between clinical parameters of initial anticoagulation and plasma levels of VK1 and VK2 (MK-4 and MK-7), it was necessary to establish a quantitative method for simultaneous determination.Materials & methods: Plasma samples in cardiovascular patients were extracted by cyclohexane and analyzed using a C18 column. Baseline concentrations of VK1, MK-4 and MK-7 were 0.98 ± 0.52 ng/ml, 0.45 ± 0.13 ng/ml and 0.65 ± 0.31 ng/ml, respectively. The concentrations of MK-7 and total VKs were significantly relevant to INR0, respectively (p = 0.010 and p = 0.048, respectively).Conclusion: Thus, when adjusting anticoagulation dosage, concentrations of various VK homologues might be considered.

Dual-Site Chemosensor for Visualizing •OH-GSH Redox and Tracking Ferroptosis-Inducing Pathways In Vivo

Oxidative stress, characterized by an imbalance between oxidative and antioxidant processes, results in excessive accumulation of intracellular reactive oxygen species. Among these responses, the regulation of intracellular hydroxyl radicals (•OH) and glutathione (GSH) is vital for physiological processes. Real-time in situ monitoring these two opposing bioactive species and their redox interactions is essential for understanding physiological balance and imbalance. In this study, we developed a dual-site fluorescence chemosensor OG-3, which can independently image both exogenous and endogenous •OH and GSH in separate channels both within cells and in vivo, eliminating issues of spatiotemporal inhomogeneous distribution and cross-interference. With its imaging capabilities of monitoring •OH-GSH redox, OG-3 elucidated two different pathways for ferroptosis induction: (i) inhibition of system xc- to block cystine uptake (extrinsic pathway) and (ii) GPX4 inactivation, leading to the loss of antioxidant defense (intrinsic pathway). Moreover, we assessed the antiferroptotic function and effects of ferroptosis inhibitors by monitoring •OH and GSH fluctuations during ferroptosis. This method provides a reliable platform for identifying potential ferroptosis inhibitors, contributing to our understanding of relevant metabolic and physiological mechanisms. It shows potential for elucidating the regulation of ferroptosis mechanisms and investigating further strategies for therapeutic applications.

Identification of a murder caused by brodifacoum poisoning based on clinical examinations and LC-MS/MS results

Brodifacoum exerts its antagonistic effect against the metabolism of vitamin K, an essential component in the synthesis of blood coagulation factors. This effect ultimately hinders the blood's capacity to clot effectively, rendering it a commonly employed rodenticide. Instances of lethal poisonings are exceedingly rare owing to expeditious medical intervention and treatment. Within this report, we present a case of brodifacoum-induced homicide, wherein the patient exhibited distinct clinical examinations and symptoms. Moreover, the patient's blood sample exhibited a noteworthy brodifacoum concentration of 0.681 µg/mL even after a period of 43 days following the incident of poisoning. Although an autopsy was not conducted due to religious restrictions, we endeavor to reasonably deduce the cause of death and furnish corroborative evidence for clinical diagnosis, treatment, and forensic examination in instances involving brodifacoum poisoning.

Therapeutic strategies of targeting non-apoptotic regulated cell death (RCD) with small-molecule compounds in cancer

Regulated cell death (RCD) is a controlled form of cell death orchestrated by one or more cascading signaling pathways, making it amenable to pharmacological intervention. RCD subroutines can be categorized as apoptotic or non-apoptotic and play essential roles in maintaining homeostasis, facilitating development, and modulating immunity. Accumulating evidence has recently revealed that RCD evasion is frequently the primary cause of tumor survival. Several non-apoptotic RCD subroutines have garnered attention as promising cancer therapies due to their ability to induce tumor regression and prevent relapse, comparable to apoptosis. Moreover, they offer potential solutions for overcoming the acquired resistance of tumors toward apoptotic drugs. With an increasing understanding of the underlying mechanisms governing these non-apoptotic RCD subroutines, a growing number of small-molecule compounds targeting single or multiple pathways have been discovered, providing novel strategies for current cancer therapy. In this review, we comprehensively summarized the current regulatory mechanisms of the emerging non-apoptotic RCD subroutines, mainly including autophagy-dependent cell death, ferroptosis, cuproptosis, disulfidptosis, necroptosis, pyroptosis, alkaliptosis, oxeiptosis, parthanatos, mitochondrial permeability transition (MPT)-driven necrosis, entotic cell death, NETotic cell death, lysosome-dependent cell death, and immunogenic cell death (ICD). Furthermore, we focused on discussing the pharmacological regulatory mechanisms of related small-molecule compounds. In brief, these insightful findings may provide valuable guidance for investigating individual or collaborative targeting approaches towards different RCD subroutines, ultimately driving the discovery of novel small-molecule compounds that target RCD and significantly enhance future cancer therapeutics.

Cyclodextrins and their potential applications for delivering vitamins, iron, and iodine for improving micronutrient status

Cyclodextrins (CDs) have been investigated as potential biopolymeric carriers that can form inclusion complexes with numerous bioactive ingredients. The inclusion of micronutrients (e.g. vitamins or minerals) into cyclodextrins can enhance their solubility and provide oxidative or thermal stability. It also enables the formulation of products with extended shelf-life. The designed delivery systems with CDs and their inclusion complexes including electrospun nanofibers, emulsions, liposomes, and hydrogels, show potential in enhancing the solubility and oxidative stability of micronutrients while enabling their controlled and sustained release in applications including food packaging, fortified foods and dietary supplements. Nano or micrometer-sized delivery systems capable of controlling burst release and permeation, or moderating skin hydration have been reported, which can facilitate the formulation of several personal and skin care products for topical or transdermal delivery of micronutrients. This review highlights recent developments in the application of CDs for the delivery of micronutrients, i.e. vitamins, iron, and iodine, which play key roles in the human body, emphasizing their existing and potential applications in the food, pharmaceuticals, and cosmeceuticals industries.

Membrane Dynamics and Cation Handling in Ferroptosis

Ferroptosis, a regulated cell death hallmarked by excessive lipid peroxidation, is implicated in various (patho)physiological contexts. During ferroptosis, lipid peroxidation leads to a diverse change in membrane properties and the dysregulation of ion homeostasis via the cation channels, ultimately resulting in plasma membrane rupture. This review illuminates cellular membrane dynamics and cation handling in ferroptosis regulation.

Vitamin K3 promotes CCL5 expression to recruit preadipocytes deposition to skeletal muscle

Intramuscular fat (IMF), also known as ectopic fat deposits in skeletal muscle. Researches of IMF mainly focus on increasing the number and size of intramuscular adipocytes in situ. However, recent studies have shown that chemokines secreted by skeletal muscle recruit adipocytes to increase intramuscular fat content. Chemokine ligand 5 (CCL5), a member of chemokine family, is involved in the regulation of cell migration, inflammatory responses, and energy metabolism. In this study, we determined Vitamin K3 (VK3) enhanced Ccl5 transcription and expression, thus resulting in increased preadipocyte migration. VK3-injected vastus lateralis (VL) was observed an increased CCL5 concentration and IMF deposition, whereas blockade of the CCL5/CCR5 axis decreased IMF deposition.VK3 treatment also increased the body weight and VL ratio in mice. In summary, VK3, which targets CCL5, is expected to be a novel pharmacological regulator for promoting IMF content.

Green Onion (Allium fistulosum): An Aromatic Vegetable Crop Esteemed for Food, Nutritional and Therapeutic Significance

In recent years, there has been a shift towards a greater demand for more nutritious and healthier foods, emphasizing the role of diets in human well-being. Edible Alliums, including common onions, garlic, chives and green onions, are staples in diverse cuisines worldwide and are valued specifically for their culinary versatility, distinct flavors and nutritional and medicinal properties. Green onions are widely cultivated and traded as a spicy vegetable. The mild, onion-like flavor makes the crop a pleasant addition to various dishes, serving as a staple ingredient in many world cuisines, particularly in Eastern Asian countries such as China, Japan and the Republic of Korea. The green pseudostems, leaves and non-developed bulbs of green onions are utilized in salads, stir-fries, garnishes and a myriad of culinary preparations. Additionally, green onions have a rich historical background in traditional medicine and diets, capturing the attention of chefs and the general public. The status of the crop as an important food, its culinary diversity and its nutraceutical and therapeutic value make it a subject of great interest in research. Therefore, the present review has examined the distribution, culinary, nutritional and therapeutic significance of green onions, highlighting the health benefits derived from the consumption of diets with this aromatic vegetable crop as a constituent.

Glutathione and glutathione-dependent enzymes: From biochemistry to gerontology and successful aging

The tripeptide glutathione (GSH), namely γ-L-glutamyl-L-cysteinyl-glycine, is an ubiquitous low-molecular weight thiol nucleophile and reductant of utmost importance, representing the central redox agent of most aerobic organisms. GSH has vital functions involving also antioxidant protection, detoxification, redox homeostasis, cell signaling, iron metabolism/homeostasis, DNA synthesis, gene expression, cysteine/protein metabolism, and cell proliferation/differentiation or death including apoptosis and ferroptosis. Various functions of GSH are exerted in concert with GSH-dependent enzymes. Indeed, although GSH has direct scavenging antioxidant effects, its antioxidant function is substantially accomplished by glutathione peroxidase-catalyzed reactions with reductive removal of H2O2, organic peroxides such as lipid hydroperoxides, and peroxynitrite; to this antioxidant activity also contribute peroxiredoxins, enzymes further involved in redox signaling and chaperone activity. Moreover, the detoxifying function of GSH is basically exerted in conjunction with glutathione transferases, which have also antioxidant properties. GSH is synthesized in the cytosol by the ATP-dependent enzymes glutamate cysteine ligase (GCL), which catalyzes ligation of cysteine and glutamate forming γ-glutamylcysteine (γ-GC), and glutathione synthase, which adds glycine to γ-GC resulting in GSH formation; GCL is rate-limiting for GSH synthesis, as is the precursor amino acid cysteine, which may be supplemented as N-acetylcysteine (NAC), a therapeutically available compound. After its cell export, GSH is degraded extracellularly by the membrane-anchored ectoenzyme γ-glutamyl transferase, a process occurring, as GSH synthesis and export, in the γ-glutamyl cycle. GSH degradation occurs also intracellularly by the cytoplasmic enzymatic ChaC family of γ-glutamyl cyclotransferase. Synthesis and degradation of GSH, together with its export, translocation to cell organelles, utilization for multiple essential functions, and regeneration from glutathione disulfide by glutathione reductase, are relevant to GSH homeostasis and metabolism. Notably, GSH levels decline during aging, an alteration generally related to impaired GSH biosynthesis and leading to cell dysfunction. However, there is evidence of enhanced GSH levels in elderly subjects with excellent physical and mental health status, suggesting that heightened GSH may be a marker and even a causative factor of increased healthspan and lifespan. Such aspects, and much more including GSH-boosting substances administrable to humans, are considered in this state-of-the-art review, which deals with GSH and GSH-dependent enzymes from biochemistry to gerontology, focusing attention also on lifespan/healthspan extension and successful aging; the significance of GSH levels in aging is considered also in relation to therapeutic possibilities and supplementation strategies, based on the use of various compounds including NAC-glycine, aimed at increasing GSH and related defenses to improve health status and counteract aging processes in humans.