scholarly journals VKORC1L1, An Enzyme Mediating the Effect of Vitamin K in Liver and Extrahepatic Tissues

Nutrients ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 970 ◽  
Author(s):  
Julie Lacombe ◽  
Mathieu Ferron

Vitamin K is an essential nutrient involved in the regulation of blood clotting and tissue mineralization. Vitamin K oxidoreductase (VKORC1) converts vitamin K epoxide into reduced vitamin K, which acts as the co-factor for the γ-carboxylation of several proteins, including coagulation factors produced by the liver. VKORC1 is also the pharmacological target of warfarin, a widely used anticoagulant. Vertebrates possess a VKORC1 paralog, VKORC1-like 1 (VKORC1L1), but until very recently, the importance of VKORC1L1 for protein γ-carboxylation and hemostasis in vivo was not clear. Here, we first review the current knowledge on the structure, function and expression pattern of VKORC1L1, including recent data establishing that, in the absence of VKORC1, VKORC1L1 can support vitamin K-dependent carboxylation in the liver during the pre- and perinatal periods in vivo. We then provide original data showing that the partial redundancy between VKORC1 and VKORC1L1 also exists in bone around birth. Recent studies indicate that, in vitro and in cell culture models, VKORC1L1 is less sensitive to warfarin than VKORC1. Genetic evidence is presented here, which supports the notion that VKORC1L1 is not the warfarin-resistant vitamin K quinone reductase present in the liver. In summary, although the exact physiological function of VKORC1L1 remains elusive, the latest findings clearly established that this enzyme is a vitamin K oxidoreductase, which can support γ-carboxylation in vivo.

1987 ◽  
Author(s):  
L J M Van Haarlem ◽  
H C Hemker ◽  
B A M Soute ◽  
C Vermeer

Vitamin K-dependent carboxylase activity has been detected in human andbovine vessel wall. Studies comparingthe carboxylases from liver and vessel wall revealed that the enzyme systems may be regarded as isoenzymes withwidely different substrate specificities. The carboxylated product of vessel wall carboxylase has not yet been identified, but it seems plausible that it will be found amongst the Gla-containing proteins which are abundantly present in calcified atherosclerotic plaques (Gla= gammacarboxyglutamicacid, the abnormal amino acid formed by vitamin K-dependent carboxylase). Therefore we have started to characterize the protein constituents of hardened atherosclerotic plaques.The calcified areas from human aortae were solubilized in EDTA and the proteins extracted were partly purified by batch-wise adsorption onto QAE and elution with high salt. The crudeplaque-extract did not contain prothrombin, factor X or protein C. This excludes the possibility that Gla-containing coagulation factors are bound non-specifically from blood. Osteocalcin accounted for 20% of the total amount of protein-bound Gla-residues.Another Gla-containing protein waspurified from the crude plaque-extract by employing high performance liquid chromatography (HPLC). Gel filtration yielded a Gla-rich protein with anapparent Mr of 25 kD. In vitro boththe crude plaque-extract and the purified Gla-containing protein strongly inhibited the precipitation of calcium phosphate and calcium carbonate. A similar effect was not found with humanserum albumin nor with a thermallydecarboxylated plaque-extract. If also in vivo the Gla-containing proteinsproduced by vessel wall carboxylase prevent the precipitation of calcium salts remains to be investigated.


2007 ◽  
Vol 81 (17) ◽  
pp. 9568-9571 ◽  
Author(s):  
Simon N. Waddington ◽  
Alan L. Parker ◽  
Menzo Havenga ◽  
Stuart A. Nicklin ◽  
Suzanne M. K. Buckley ◽  
...  

ABSTRACT Vitamin K-dependent coagulation factors can promote adenoviral cell transduction in vitro. In vivo, warfarin pretreatment ablates liver targeting of an adenovirus serotype 5 (Ad5) vector deleted of CAR binding capability. Here, we assess in vivo transduction and biodistribution of Ad5 vectors with nonmodified fibers (Ad5) and a serotype 47 fiber-pseudotyped Ad5 (Ad5/47; subgroup D) virus following intravascular injection. Warfarin reduced liver transduction by both viruses. However, no impact on early liver virus accumulation was observed, suggesting no effect on Kupffer cell interactions. Hence, coagulation factors play a pivotal role in selectively mediating liver hepatocyte transduction of Ad5 and Ad5/47 vectors.


2020 ◽  
Vol 20 ◽  
Author(s):  
Nur Najmi Mohamad Anuar ◽  
Nurul Iman Natasya Zulkafali ◽  
Azizah Ugusman

: Matrix metalloproteinases (MMPs) are a group of zinc-dependent metallo-endopeptidase that are responsible towards the degradation, repair and remodelling of extracellular matrix components. MMPs play an important role in maintaining a normal physiological function and preventing diseases such as cancer and cardiovascular diseases. Natural products derived from plants have been used as traditional medicine for centuries. Its active compounds, such as catechin, resveratrol and quercetin, are suggested to play an important role as MMPs inhibitors, thereby opening new insights into their applications in many fields, such as pharmaceutical, cosmetic and food industries. This review summarises the current knowledge on plant-derived natural products with MMP-modulating activities. Most of the reviewed plant-derived products exhibit an inhibitory activity on MMPs. Amongst MMPs, MMP-2 and MMP-9 are the most studied. The expression of MMPs is inhibited through respective signalling pathways, such as MAPK, NF-κB and PI3 kinase pathways, which contribute to the reduction in cancer cell behaviours, such as proliferation and migration. Most studies have employed in vitro models, but a limited number of animal studies and clinical trials have been conducted. Even though plant-derived products show promising results in modulating MMPs, more in vivo studies and clinical trials are needed to support their therapeutic applications in the future.


2019 ◽  
Vol 14 (4) ◽  
pp. 305-319 ◽  
Author(s):  
Marietta Herrmann ◽  
Franz Jakob

The bone marrow hosts skeletal progenitor cells which have most widely been referred to as Mesenchymal Stem or Stromal Cells (MSCs), a heterogeneous population of adult stem cells possessing the potential for self-renewal and multilineage differentiation. A consensus agreement on minimal criteria has been suggested to define MSCs in vitro, including adhesion to plastic, expression of typical surface markers and the ability to differentiate towards the adipogenic, osteogenic and chondrogenic lineages but they are critically discussed since the differentiation capability of cells could not always be confirmed by stringent assays in vivo. However, these in vitro characteristics have led to the notion that progenitor cell populations, similar to MSCs in bone marrow, reside in various tissues. MSCs are in the focus of numerous (pre)clinical studies on tissue regeneration and repair.Recent advances in terms of genetic animal models enabled a couple of studies targeting skeletal progenitor cells in vivo. Accordingly, different skeletal progenitor cell populations could be identified by the expression of surface markers including nestin and leptin receptor. While there are still issues with the identity of, and the overlap between different cell populations, these studies suggested that specific microenvironments, referred to as niches, host and maintain skeletal progenitor cells in the bone marrow. Dynamic mutual interactions through biological and physical cues between niche constituting cells and niche inhabitants control dormancy, symmetric and asymmetric cell division and lineage commitment. Niche constituting cells, inhabitant cells and their extracellular matrix are subject to influences of aging and disease e.g. via cellular modulators. Protective niches can be hijacked and abused by metastasizing tumor cells, and may even be adapted via mutual education. Here, we summarize the current knowledge on bone marrow skeletal progenitor cell niches in physiology and pathophysiology. We discuss the plasticity and dynamics of bone marrow niches as well as future perspectives of targeting niches for therapeutic strategies.


2005 ◽  
Vol 83 (4) ◽  
pp. 535-547 ◽  
Author(s):  
Gareth N Corry ◽  
D Alan Underhill

To date, the majority of the research regarding eukaryotic transcription factors has focused on characterizing their function primarily through in vitro methods. These studies have revealed that transcription factors are essentially modular structures, containing separate regions that participate in such activities as DNA binding, protein–protein interaction, and transcriptional activation or repression. To fully comprehend the behavior of a given transcription factor, however, these domains must be analyzed in the context of the entire protein, and in certain cases the context of a multiprotein complex. Furthermore, it must be appreciated that transcription factors function in the nucleus, where they must contend with a variety of factors, including the nuclear architecture, chromatin domains, chromosome territories, and cell-cycle-associated processes. Recent examinations of transcription factors in the nucleus have clarified the behavior of these proteins in vivo and have increased our understanding of how gene expression is regulated in eukaryotes. Here, we review the current knowledge regarding sequence-specific transcription factor compartmentalization within the nucleus and discuss its impact on the regulation of such processes as activation or repression of gene expression and interaction with coregulatory factors.Key words: transcription, subnuclear localization, chromatin, gene expression, nuclear architecture.


Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 78
Author(s):  
Lachlan A. Bourke ◽  
Christina N. Zdenek ◽  
Edgar Neri-Castro ◽  
Melisa Bénard-Valle ◽  
Alejandro Alagón ◽  
...  

The toxin composition of snake venoms and, thus, their functional activity, can vary between and within species. Intraspecific venom variation across a species’ geographic range is a major concern for antivenom treatment of envenomations, particularly for countries like French Guiana that lack a locally produced antivenom. Bothrops asper and Bothrops atrox are the most medically significant species of snakes in Latin America, both producing a variety of clinical manifestations, including systemic bleeding. These pathophysiological actions are due to the activation by the venom of the blood clotting factors Factor X and prothrombin, thereby causing severe consumptive coagulopathy. Both species are extremely wide-ranging, and previous studies have shown their venoms to exhibit regional venom variation. In this study, we investigate the differential coagulotoxic effects on human plasma of six venoms (four B. asper and two B. atrox samples) from different geographic locations, spanning from Mexico to Peru. We assessed how the venom variation of these venom samples affects neutralisation by five regionally available antivenoms: Antivipmyn, Antivipmyn-Tri, PoliVal-ICP, Bothrofav, and Soro Antibotrópico (SAB). The results revealed both inter- and intraspecific variations in the clotting activity of the venoms. These variations in turn resulted in significant variation in antivenom efficacy against the coagulotoxic effects of these venoms. Due to variations in the venoms used in the antivenom production process, antivenoms differed in their species-specific or geographical neutralisation capacity. Some antivenoms (PoliVal-ICP, Bothrofav, and SAB) showed species-specific patterns of neutralisation, while another antivenom (Antivipmyn) showed geographic-specific patterns of neutralisation. This study adds to current knowledge of Bothrops venoms and also illustrates the importance of considering evolutionary biology when developing antivenoms. Therefore, these results have tangible, real-world implications by aiding evidence-based design of antivenoms for treatment of the envenomed patient. We stress that these in vitro studies must be backed by future in vivo studies and clinical trials before therapeutic guidelines are issued regarding specific antivenom use in a clinical setting.


2021 ◽  
Vol 22 (9) ◽  
pp. 4368
Author(s):  
Heriberto Rodriguez-Martinez ◽  
Emilio A. Martinez ◽  
Juan J. Calvete ◽  
Fernando J. Peña Vega ◽  
Jordi Roca

Seminal plasma (SP), the non-cellular component of semen, is a heterogeneous composite fluid built by secretions of the testis, the epididymis and the accessory sexual glands. Its composition, despite species-specific anatomical peculiarities, consistently contains inorganic ions, specific hormones, proteins and peptides, including cytokines and enzymes, cholesterol, DNA and RNA—the latter often protected within epididymis- or prostate-derived extracellular vesicles. It is beyond question that the SP participates in diverse aspects of sperm function pre-fertilization events. The SP also interacts with the various compartments of the tubular genital tract, triggering changes in gene function that prepares for an eventual successful pregnancy; thus, it ultimately modulates fertility. Despite these concepts, it is imperative to remember that SP-free spermatozoa (epididymal or washed ejaculated) are still fertile, so this review shall focus on the differences between the in vivo roles of the SP following semen deposition in the female and those regarding additions of SP on spermatozoa handled for artificial reproduction, including cryopreservation, from artificial insemination to in vitro fertilization. This review attempts, including our own results on model animal species, to critically summarize the current knowledge of the reproductive roles played by SP components, particularly in our own species, which is increasingly affected by infertility. The ultimate goal is to reconcile the delicate balance between the SP molecular concentration and their concerted effects after temporal exposure in vivo. We aim to appraise the functions of the SP components, their relevance as diagnostic biomarkers and their value as eventual additives to refine reproductive strategies, including biotechnologies, in livestock models and humans.


2021 ◽  
Vol 1 (1) ◽  
pp. 84-95
Author(s):  
Patience O. Obi ◽  
Jennifer E. Kent ◽  
Maya M. Jeyaraman ◽  
Nicole Askin ◽  
Taiana M. Pierdoná ◽  
...  

Asthma is the most common pediatric disease, characterized by chronic airway inflammation and airway hyperresponsiveness. There are several management options for asthma, but no specific treatment. Extracellular vesicles (EVs) are powerful cellular mediators of endocrine, autocrine and paracrine signalling, and can modulate biophysiological function in vitro and in vivo. A thorough investigation of therapeutic effects of EVs in asthma has not been conducted. Therefore, this systematic review is designed to synthesize recent literature on the therapeutic effects of EVs on physiological and biological outcomes of asthma in pre-clinical studies. An electronic search of Web of Science, EMBASE, MEDLINE, and Scopus will be conducted on manuscripts published in the last five years that adhere to standardized guidelines for EV research. Grey literature will also be included. Two reviewers will independently screen the selected studies for title and abstract, and full text based on the eligibility criteria. Data will be extracted, narratively synthesized and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. This systematic review will summarize the current knowledge from preclinical studies investigating the therapeutic effects of EVs on asthma. The results will delineate whether EVs can mitigate biological hallmarks of asthma, and if so, describe the underlying mechanisms involved in the process. This insight is crucial for identifying key pathways that can be targeted to alleviate the burden of asthma. The data will also reveal the origin, dosage and biophysical characteristics of beneficial EVs. Overall, our results will provide a scaffold for future intervention and translational studies on asthma treatment.


Author(s):  
Alessio Facciolà ◽  
Giuseppa Visalli ◽  
Marianna Pruiti Ciarello ◽  
Angela Di Pietro

Plastics are ubiquitous persistent pollutants, forming the most representative material of the Anthropocene. In the environment, they undergo wear and tear (i.e., mechanical fragmentation, and slow photo and thermo-oxidative degradation) forming secondary microplastics (MPs). Further fragmentation of primary and secondary MPs results in nanoplastics (NPs). To assess potential health damage due to human exposure to airborne MPs and NPs, we summarize the evidence collected to date that, however, has almost completely focused on monitoring and the effects of airborne MPs. Only in vivo and in vitro studies have assessed the toxicity of NPs, and a standardized method for their analysis in environmental matrices is still missing. The main sources of indoor and outdoor exposure to these pollutants include synthetic textile fibers, rubber tires, upholstery and household furniture, and landfills. Although both MPs and NPs can reach the alveolar surface, the latter can pass into the bloodstream, overcoming the pulmonary epithelial barrier. Despite the low reactivity, the number of surface area atoms per unit mass is high in MPs and NPs, greatly enhancing the surface area for chemical reactions with bodily fluids and tissue in direct contact. This is proven in polyvinyl chloride (PVC) and flock workers, who are prone to persistent inflammatory stimulation, leading to pulmonary fibrosis or even carcinogenesis.


Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1382
Author(s):  
Mina Martini ◽  
Iolanda Altomonte ◽  
Domenico Tricò ◽  
Riccardo Lapenta ◽  
Federica Salari

The increase of knowledge on the composition of donkey milk has revealed marked similarities to human milk, which led to a growing number of investigations focused on testing the potential effects of donkey milk in vitro and in vivo. This paper examines the scientific evidence regarding the beneficial effects of donkey milk on human health. Most clinical studies report a tolerability of donkey milk in 82.6–98.5% of infants with cow milk protein allergies. The average protein content of donkey milk is about 18 g/L. Caseins, which are main allergenic components of milk, are less represented compared to cow milk (56% of the total protein in donkey vs. 80% in cow milk). Donkey milk is well accepted by children due to its high concentration of lactose (about 60 g/L). Immunomodulatory properties have been reported in one study in humans and in several animal models. Donkey milk also seems to modulate the intestinal microbiota, enhance antioxidant defense mechanisms and detoxifying enzymes activities, reduce hyperglycemia and normalize dyslipidemia. Donkey milk has lower calorie and fat content compared with other milks used in human nutrition (fat ranges from 0.20% to 1.7%) and a more favourable fatty acid profile, being low in saturated fatty acids (3.02 g/L) and high in alpha-linolenic acid (about 7.25 g/100 g of fat). Until now, the beneficial properties of donkey milk have been mostly related to whey proteins, among which β-lactoglobulin is the most represented (6.06 g/L), followed by α-lactalbumin (about 2 g/L) and lysozyme (1.07 g/L). So far, the health functionality of donkey milk has been tested almost exclusively on animal models. Furthermore, in vitro studies have described inhibitory action against bacteria, viruses, and fungi. From the literature review emerges the need for new randomized clinical trials on humans to provide stronger evidence of the potential beneficial health effects of donkey milk, which could lead to new applications as an adjuvant in the treatment of cardiometabolic diseases, malnutrition, and aging.


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