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Nutrients Mar 2022Vitamin A is vital to maternal-fetal health and pregnancy outcomes. However, little is known about pregnancy associated changes in maternal vitamin A homeostasis and...
Vitamin A is vital to maternal-fetal health and pregnancy outcomes. However, little is known about pregnancy associated changes in maternal vitamin A homeostasis and concentrations of circulating retinol metabolites. The goal of this study was to characterize retinoid concentrations in healthy women ( = 23) during two stages of pregnancy (25-28 weeks gestation and 28-32 weeks gestation) as compared to ≥3 months postpartum. It was hypothesized that plasma retinol, retinol binding protein 4 (RBP4), transthyretin and albumin concentrations would decline during pregnancy and return to baseline by 3 months postpartum. At 25-28 weeks gestation, plasma retinol (-27%), 4-oxo-13--retinoic acid (-34%), and albumin (-22%) concentrations were significantly lower, and -retinoic acid (+48%) concentrations were significantly higher compared to ≥3 months postpartum in healthy women. In addition, at 28-32 weeks gestation, plasma retinol (-41%), retinol binding protein 4 (RBP4; -17%), transthyretin (TTR; -21%), albumin (-26%), 13--retinoic acid (-23%) and 4-oxo-13--retinoic acid (-48%) concentrations were significantly lower, whereas plasma -retinoic acid concentrations (+30%) were significantly higher than ≥3 months postpartum. Collectively, the data demonstrates that in healthy pregnancies, retinol plasma concentrations are lower, but -retinoic acid concentrations are higher than postpartum.
Topics: Female; Humans; Prealbumin; Pregnancy; Pregnant Women; Retinoids; Retinol-Binding Proteins, Plasma; Tretinoin; Vitamin A
PubMed: 35405978
DOI: 10.3390/nu14071365 -
Current Neuropharmacology 2021Retinoic acid, a metabolite of vitamin A, acts through either genomic or nongenomic actions. The genomic action of retinoids exerts effects on gene transcription through...
Retinoic acid, a metabolite of vitamin A, acts through either genomic or nongenomic actions. The genomic action of retinoids exerts effects on gene transcription through interaction with retinoid receptors such as retinoic acid receptors (RARα, β, and γ) and retinoid X receptors (RXRα, β, and γ) that are primarily concentrated in the amygdala, pre-frontal cortex, and hippocampal areas in the brain. In response to retinoid binding, RAR/RXR heterodimers undergo major conformational changes and orchestrate the transcription of specific gene networks. Previous experimental studies have reported that retinoic acid exerts an antiepileptogenic effect through diverse mechanisms, including the modulation of gap junctions, neurotransmitters, long-term potentiation, calcium channels and some genes. To our knowledge, there are no previous or current clinical trials evaluating the use of retinoic acid for seizure control.
Topics: Humans; Receptors, Retinoic Acid; Retinoids; Tretinoin
PubMed: 32351181
DOI: 10.2174/1570159X18666200429232104 -
International Journal of Molecular... Aug 2023Lutein, zeaxanthin, and -zeaxanthin (a steroisomer of zeaxanthin) are macular pigments. They modify the physical properties of the lipid bilayers in a manner similar to... (Review)
Review
Lutein, zeaxanthin, and -zeaxanthin (a steroisomer of zeaxanthin) are macular pigments. They modify the physical properties of the lipid bilayers in a manner similar to cholesterol. It is not clear if these pigments are directly present in the lipid phase of the membranes, or if they form complexes with specific membrane proteins that retain them in high amounts in the correct place in the retina. The high content of macular pigments in the Henle fiber layer indicates that a portion of the lutein and zeaxanthin should not only be bound to the specific proteins but also directly dissolved in the lipid membranes. This high concentration in the prereceptoral region of the retina is effective for blue-light filtration. Understanding the basic mechanisms of these actions is necessary to better understand the carotenoid-membrane interaction and how carotenoids affect membrane physical properties-such as fluidity, polarity, and order-in relation to membrane structure and membrane dynamics. This review focuses on the properties of lutein.
Topics: Lutein; Zeaxanthins; Membranes; Carotenoids; Lipid Bilayers
PubMed: 37629129
DOI: 10.3390/ijms241612948 -
Yakugaku Zasshi : Journal of the... 2021"Retinoid" is the general term for vitamin A derivatives and chemical compounds that act like vitamin A. Vitamin A are composed of four isoprene units and are named... (Review)
Review
"Retinoid" is the general term for vitamin A derivatives and chemical compounds that act like vitamin A. Vitamin A are composed of four isoprene units and are named according to their terminal functional group, such as retinol (OH, 1), retinal (CHO, 2), and retinoic acid (COH, 3). Vitamin A usually refers to retinol. In the past few decades, major advances in research on vitamin A have improved our understanding of its fundamental roles and physiological significance in living cells. In this review, three types of chemical biology studies using vitamin A analogs are described: (1) conformational studies of the chromophore in retinal proteins (rhodopsin, phoborhodopsin, and retinochrome), especially the conformation around the cyclohexene ring; (2) structure-activity relationship studies of retinoic acid analogs to create new signaling molecules for activating nuclear receptors; and (3) development of a new channelrhodopsin with an absorption maximum at longer wavelength to overcome the various demerits of channelrhodopsins used in optogenetics, as well as the stereoselective synthesis of retinoid isomers and their analogs using a diene-tricarbonyliron complex or a palladium-catalyzed cross-coupling reaction between vinyl triflates and stannyl olefins.
Topics: Alkenes; Catalysis; Channelrhodopsins; Cyclohexenes; Eye Proteins; Isomerism; Mesylates; Molecular Conformation; Nuclear Reactors; Palladium; Retinoids; Stereoisomerism; Structure-Activity Relationship; Vinyl Compounds; Vitamin A
PubMed: 33790122
DOI: 10.1248/yakushi.20-00230 -
Molecules (Basel, Switzerland) Aug 2021This paper presents the results of the first part of testing a novel electrospun fiber mat based on a unique macromolecule: polyisobutylene (PIB). A PIB-based compound...
This paper presents the results of the first part of testing a novel electrospun fiber mat based on a unique macromolecule: polyisobutylene (PIB). A PIB-based compound containing zinc oxide (ZnO) was electrospun into self-supporting mats of 203.75 and 295.5 g/m that were investigated using a variety of techniques. The results show that the hydrophobic mats are not cytotoxic, resist fibroblast cell adhesion and biofilm formation and are comfortable and easy to breathe through for use as a mask. The mats show great promise for personal protective equipment and other applications.
Topics: Biofilms; Cell Adhesion; Cells, Cultured; Fibroblasts; Humans; Materials Testing; Nanofibers; Polyenes; Polymers; Zinc Oxide
PubMed: 34500639
DOI: 10.3390/molecules26175207 -
Progress in Retinal and Eye Research Mar 2023The eye is an ideal organ for imaging by a multi-photon excitation approach, because ocular tissues such as the sclera, cornea, lens and neurosensory retina, are highly... (Review)
Review
The eye is an ideal organ for imaging by a multi-photon excitation approach, because ocular tissues such as the sclera, cornea, lens and neurosensory retina, are highly transparent to infrared (IR) light. The interface between the retina and the retinal pigment epithelium (RPE) is especially informative, because it reflects the health of the visual (retinoid) cycle and its changes in response to external stress, genetic manipulations, and drug treatments. Vitamin A-derived retinoids, like retinyl esters, are natural fluorophores that respond to multi-photon excitation with near IR light, bypassing the filter-like properties of the cornea, lens, and macular pigments. Also, during natural aging some retinoids form bisretinoids, like diretinoid-pyridiniumethanolamine (A2E), that are highly fluorescent. These bisretinoids appear to be elevated concurrently with aging. Vitamin A-derived retinoids and bisretinoidss are detected by two-photon ophthalmoscopy (2PO), using a new class of light sources with adjustable spatial, temporal, and spectral properties. Furthermore, the two-photon (2P) absorption of IR light by the visual pigments in rod and cone photoreceptors can initiate visual transduction by cis-trans isomerization of retinal, enabling parallel functional studies. Recently we overcame concerns about safety, data interpretation and complexity of the 2P-based instrumentation, the major roadblocks toward advancing this modality to the clinic. These imaging and retina-function assessment advancements have enabled us to conduct the first 2P studies with humans.
Topics: Humans; Mice; Animals; Vision, Ocular; Vitamin A; Retina; Retinoids; Retinal Pigment Epithelium
PubMed: 36787681
DOI: 10.1016/j.preteyeres.2023.101170 -
Translational Psychiatry Feb 2023The small, hormone-like molecule retinoic acid (RA) is a vital regulator in several neurobiological processes that are affected in depression. Next to its involvement in...
The small, hormone-like molecule retinoic acid (RA) is a vital regulator in several neurobiological processes that are affected in depression. Next to its involvement in dopaminergic signal transduction, neuroinflammation, and neuroendocrine regulation, recent studies highlight the role of RA in homeostatic synaptic plasticity and its link to neuropsychiatric disorders. Furthermore, experimental studies and epidemiological evidence point to the dysregulation of retinoid homeostasis in depression. Based on this evidence, the present study investigated the putative link between retinoid homeostasis and depression in a cohort of 109 patients with major depressive disorder (MDD) and healthy controls. Retinoid homeostasis was defined by several parameters. Serum concentrations of the biologically most active Vitamin A metabolite, all-trans RA (at-RA), and its precursor retinol (ROL) were quantified and the individual in vitro at-RA synthesis and degradation activity was assessed in microsomes of peripheral blood-derived mononuclear cells (PBMC). Additionally, the mRNA expression of enzymes relevant to retinoid signaling, transport, and metabolism were assessed. Patients with MDD had significantly higher ROL serum levels and greater at-RA synthesis activity than healthy controls providing evidence of altered retinoid homeostasis in MDD. Furthermore, MDD-associated alterations in retinoid homeostasis differed between men and women. This study is the first to investigate peripheral retinoid homeostasis in a well-matched cohort of MDD patients and healthy controls, complementing a wealth of preclinical and epidemiological findings that point to a central role of the retinoid system in depression.
Topics: Male; Humans; Female; Retinoids; Depressive Disorder, Major; Leukocytes, Mononuclear; Tretinoin; Vitamin A; Homeostasis
PubMed: 36813763
DOI: 10.1038/s41398-023-02362-0 -
Nutrients Jul 2022Paraoxonase 1 (PON1) is an antioxidant enzyme attached to HDL with an anti-atherogenic potential. It protects LDL and HDL from lipid peroxidation. The enzyme is... (Review)
Review
Paraoxonase 1 (PON1) is an antioxidant enzyme attached to HDL with an anti-atherogenic potential. It protects LDL and HDL from lipid peroxidation. The enzyme is sensitive to various modulating factors, such as genetic polymorphisms as well as pharmacological, dietary (including carotenoids), and lifestyle interventions. Carotenoids are nutritional pigments with antioxidant activity. The aim of this review was to gather evidence on their effect on the modulation of PON1 activity and gene expression. Carotenoids administered as naturally occurring nutritional mixtures may present a synergistic beneficial effect on PON1 status. The effect of carotenoids on the enzyme depends on age, ethnicity, gender, diet, and PON1 genetic variation. Carotenoids, especially astaxanthin, β-carotene, and lycopene, increase PON1 activity. This effect may be explained by their ability to quench singlet oxygen and scavenge free radicals. β-carotene and lycopene were additionally shown to upregulate PON1 gene expression. The putative mechanisms of such regulation involve PON1 CpG-rich region methylation, Ca(2+)/calmodulin-dependent kinase II (CaMKKII) pathway induction, and upregulation via steroid regulatory element-binding protein-2 (SREBP-2). More detailed and extensive research on the mechanisms of PON1 modulation by carotenoids may lead to the development of new targeted therapies for cardiovascular diseases.
Topics: Antioxidants; Aryldialkylphosphatase; Carotenoids; Gene Expression; Lycopene; beta Carotene
PubMed: 35889799
DOI: 10.3390/nu14142842 -
Molecules (Basel, Switzerland) Apr 2022Nutrition is of utmost importance in chronic disease management and has often been described as the cornerstone of a variety of non-communicable diseases. In particular,... (Review)
Review
Nutrition is of utmost importance in chronic disease management and has often been described as the cornerstone of a variety of non-communicable diseases. In particular, type II diabetes mellitus (T2DM) represents a prevalent and global public health crisis. Lycopene, a bright red carotenoid hydrocarbon found in tomatoes and other red fruits and vegetables, has been extensively studied for its biological activities and treatment efficiency in diabetes care. Epidemiological investigations indicate that lycopene has potential antioxidant properties, is capable of scavenging reactive species, and alleviates oxidative stress in T2DM patients. This review aims to summarize the characteristics and mechanisms of action of lycopene as a potent antioxidant for T2DM. In addition, the evidence demonstrating the effects of lycopene on glycemic control and oxidative stress biomarkers in T2DM are also highlighted using animal and human studies as literature approach.
Topics: Animals; Antioxidants; Carotenoids; Diabetes Mellitus, Type 2; Humans; Lycopene; Oxidative Stress
PubMed: 35408734
DOI: 10.3390/molecules27072335 -
Nutrients Dec 2021Head and neck cancer (HNC) includes oral cavity cancer (OCC), pharyngeal cancer (PC), and laryngeal cancer (LC). It is one of the most frequent cancers in the world.... (Review)
Review
Head and neck cancer (HNC) includes oral cavity cancer (OCC), pharyngeal cancer (PC), and laryngeal cancer (LC). It is one of the most frequent cancers in the world. Smoking and alcohol consumption are the typical well-known predictors of HNC. Human papillomavirus (HPV) is an increasing etiological factor for oropharyngeal cancer (OPC). Moreover, food and nutrition play an important role in HNC etiology. According to the World Cancer Research Fund and the American Institute for Cancer Research, an intake of non-starchy vegetables and fruits could decrease HNC risk. The carotenoids included in vegetables and fruits are well-known antioxidants which have anti-mutagenic and immune regulatory functions. Numerous studies have shown the relationship between carotenoid intake and a lower HNC risk, but the role of carotenoids in HNC risk is not well defined. The goal of this review is to present the current literature regarding the relationship between various carotenoids and HNC risk.
Topics: Carotenoids; Head and Neck Neoplasms; Humans; Risk Factors
PubMed: 35010963
DOI: 10.3390/nu14010088