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Frontiers in Endocrinology 2022The terms "vitamin A" and "retinoids" encompass a group of fat-soluble compounds essential for human nutrition. Some of them (retinol, retinal, 9-cis-retinoic acid,... (Review)
Review
The terms "vitamin A" and "retinoids" encompass a group of fat-soluble compounds essential for human nutrition. Some of them (retinol, retinal, 9-cis-retinoic acid, tretinoin, and 13-cis-retinoic acid) are fully natural, while others are synthetic compounds used mostly for therapeutic purposes. Some evidence indicates that the nutritional status of these retinoids (i.e., the presence or absence of deficiency) is able to modulate thyroid gland metabolism. Vitamin A deficiency is tightly correlated with structural and functional impairment of the thyroid gland and is often associated with iodine deficiency. Furthermore, retinoids are involved in different immune functions, as well as in the process of activation, proliferation, and differentiation of regulatory T cells (Treg). This is particularly significant given the high prevalence of thyroid autoimmune disorders, whose pathogenesis seems to be related to the altered homeostasis of regulatory T cells. Retinoids are also involved in the modulation of gene expression their interaction with nuclear receptors, and they also act as cofactors in cell growth and differentiation. The ability of retinoic acid to increase iodine uptake and sodium-iodine symporter activity in human thyroid cancer cell lines suggests that some retinoids and their derivatives may be of use in the treatment of different thyroid tumors. This minireview summarizes the current knowledge on the link between nutritional intake of vitamin A and various thyroid disorders.
Topics: Humans; Vitamin A; Thyroid Gland; Retinoids; Tretinoin; Iodine; Vitamins
PubMed: 36303869
DOI: 10.3389/fendo.2022.968215 -
Journal of Nutritional Science and... 2023Childhood obesity has become a public health concern. As the importance of vitamin A (VA) in the body has become increasingly acknowledged, there is limited clinical... (Review)
Review
Childhood obesity has become a public health concern. As the importance of vitamin A (VA) in the body has become increasingly acknowledged, there is limited clinical trial evidence to substantiate the association between VA and childhood obesity. Vitamin A deficiency (VAD) increases the risk of childhood obesity, a finding consistently reported in pregnant women. VA could regulate the adipogenic process, inflammation, oxidative stress and metabolism-related gene expression in mature adipocytes. VAD disrupts the balance of obesity-related metabolism, thus affecting lipid metabolism and insulin regulation. Conversely, VA supplementation has a major impact on efficacy in obesity, and obese individuals typically have a lower VA status than normal-weight individuals. Several studies have attempted to identify the genetic and molecular mechanisms underlying the association between VA and obesity. In this review, we summarize and discuss recent new developments focusing on retinol, retinoic acid, and RBP4 and elucidate and provide an overview of the complex interrelationships between these critical components of VA and childhood obesity. However, the causal relationship between VA status and childhood obesity remains unclear. It is also unknown whether VA supplementation improves the overall obesogenic metabolic profile.
Topics: Pregnancy; Humans; Child; Female; Vitamin A; Pediatric Obesity; Vitamin A Deficiency; Tretinoin; Insulin; Retinol-Binding Proteins, Plasma
PubMed: 37394420
DOI: 10.3177/jnsv.69.157 -
Behavioural Neurology 2021Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental disorder. Over the past few decades, many studies have investigated the effects of VA... (Review)
Review
Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental disorder. Over the past few decades, many studies have investigated the effects of VA supplementation in ASD patients and the relationship between vitamin A (VA) levels and ASD. VA is an essential micronutrient that plays an important role in various systems and biological processes in the form of retinoic acid (RA). Recent studies have shown that serum VA concentration is negatively correlated with the severity of ASD. The lack of VA during pregnancy or early fetal development can affect brain development and lead to long-term or even permanent impairment in the learning process, memory formation, and cognitive function. In addition, VA deficiency has been reported to have a major impact on the gastrointestinal function of children with ASD, while VA supplementation has been shown to improve the symptoms of ASD to a certain extent. This paper provides a comprehensive review of the relationship between VA and ASD.
Topics: Autism Spectrum Disorder; Child; Humans; Vitamin A
PubMed: 34917197
DOI: 10.1155/2021/5417497 -
Methods in Molecular Biology (Clifton,... 2023Retinoic acid (RA) and the family of molecules based on vitamin A known as retinoids have remarkable effects on limb regeneration in salamanders and newts and cause...
Retinoic acid (RA) and the family of molecules based on vitamin A known as retinoids have remarkable effects on limb regeneration in salamanders and newts and cause whole limb duplications in a concentration-dependent manner. They respecify all three axes of the limb-the proximodistal, the anteroposterior, and the dorsoventral axis. As a result, complete limbs can be induced to regenerate from distal amputation planes producing two limbs in tandem. Here, we describe the basic methods for undertaking these experiments as well as the use of new synthetic retinoids which have retinoic acid receptor-selective actions. These will be valuable tools in future studies on the molecular basis of limb duplications and thus our understanding of the nature of positional information in the regenerating salamander limb.
Topics: Animals; Tretinoin; Vitamin A; Retinoids; Salamandridae; Extremities; Receptors, Retinoic Acid
PubMed: 36272081
DOI: 10.1007/978-1-0716-2659-7_17 -
Journal of Comparative Physiology. A,... May 2020The recognition that a dietary factor is essential to maintain good and sensitive vision as well as overall health goes back over 3,000 years to the ancient Egyptians.... (Review)
Review
The recognition that a dietary factor is essential to maintain good and sensitive vision as well as overall health goes back over 3,000 years to the ancient Egyptians. With the discovery of the vitamins at the turn of the twentieth century, fat-soluble vitamin A was soon shown to be the essential factor. In the first half of the twentieth century, the role vitamin A plays in vision, as precursor to the light-sensitive visual pigment molecules in the photoreceptors was elegantly worked out, especially by George Wald and his colleagues. Beginning in the 1960s, with the recognition of the active metabolite of vitamin A, its acid form now called retinoic acid, the roles of vitamin A in maintaining overall health of an organism began to be explored, and this research continues to this day. Receptors activated by retinoic acid, the RARs and RXRs have been shown to regulate gene transcription in a surprisingly wide variety of biological processes from early growth and development to the maintenance of epithelial tissues in many organs, the regulation of the immune system, and even the modulation of synaptic function in the brain involved in mechanisms underlying memory and learning. Therapeutic uses for retinoic acid have been developed, including one for a specific form of leukemia. The story is by no means complete and it is likely more surprises await with regard to this remarkable molecule.
Topics: Humans; Infant; Infant Mortality; Neuronal Plasticity; Receptors, Retinoic Acid; Signal Transduction; Vision, Ocular; Vitamin A
PubMed: 32034476
DOI: 10.1007/s00359-020-01403-z -
Methods in Enzymology 2020Vitamin A signaling pathways are predominantly driven by the cellular concentrations of all-trans-retinoic acid (atRA), as the main mechanism of retinoid signaling is...
Vitamin A signaling pathways are predominantly driven by the cellular concentrations of all-trans-retinoic acid (atRA), as the main mechanism of retinoid signaling is via activation of retinoic acid receptors. atRA concentrations are in turn controlled by the storage of vitamin A and enzymatic processes that synthesize and clear atRA. This has resulted in the need for robust and highly specific analytical methods to accurately quantify retinoids in diverse biological matrices. Tissue-specific differences in both the quantity of retinoids and background matrix interferences can confound the quantification of retinoids, and the bioanalysis requires high performance instrumentation, such as liquid chromatography mass-spectrometry (LC-MS). Successful bioanalysis of retinoids is further complicated by the innate structural instability of retinoids and their relatively high lipophilicity. Further, in vitro experiments with retinoids require attention to experimental design and interpretation to account for the instability of retinoids due to isomerization and degradation, sequential metabolism to numerous structurally similar metabolites, and substrate depletion during experiments. In addition, in vitro biological activity is often confounded by residual presence of retinoids in common biological reagents such as cell culture media. This chapter identifies common biological and analytical complexities in retinoid bioanalysis in diverse biological matrices, and in the use of retinoids in cell culture and metabolic incubations. In addition, this chapter highlights best practices for the successful detection and quantification of the vitamin A metabolome in a wide range of biological matrices.
Topics: Receptors, Retinoic Acid; Retinoids; Signal Transduction; Tretinoin; Vitamin A
PubMed: 32359651
DOI: 10.1016/bs.mie.2020.02.010 -
Hepatology Communications May 2023Vitamin A, a fat-soluble vitamin that includes retinol and carotenoids, is implicated in liver fibrosis, whereas its deficiency has been associated with various liver...
INTRODUCTION
Vitamin A, a fat-soluble vitamin that includes retinol and carotenoids, is implicated in liver fibrosis, whereas its deficiency has been associated with various liver diseases and higher overall mortality. This study aims to determine the relationship between levels of vitamin A species and liver fibrosis, as well as liver-related mortality in the population of the US.
METHODS
A total of 12,299 participants from the National Health and Nutrition Examination Survey III (NHANES III) were analyzed to provide nationally representative estimates of the relationship between the levels of vitamin A species and liver fibrosis measured by Fibrosis-4 (FIB-4) index and liver-related mortality.
RESULTS
A low blood level of retinol, but not other retinoid derivatives, was associated with significant liver fibrosis after adjustment for demographics, anthropometric measurements, medical history, retinol, and carotene intakes. Compared with vitamin D and E, retinol deficiency demonstrated much stronger associations with a high FIB-4 score. Individuals with known risks of chronic liver disease (CLD) and the lowest pentile of retinol levels had ORs of 3.12 (95% CI, 1.64-5.91) for possible fibrosis and 19.7 (95% CI, 5.71-67.7) for likely fibrosis, and an HR of 7.76 (95% CI, 1.19-50.5) for liver-related mortality compared with those in the highest retinol-level pentile. These relationships were more pronounced among individuals with known risks of chronic liver disease than without.
CONCLUSIONS
A low circulating retinol level is associated with liver fibrosis and liver-related mortality in chronic liver disease. This relationship is potentially driven by a mechanistic link rather than the malabsorption of fat-soluble vitamins and may be leveraged for disease prognostication and have therapeutic implications.
Topics: Humans; Vitamin A; Nutrition Surveys; Cohort Studies; Carotenoids; Liver Diseases; Liver Cirrhosis
PubMed: 37058112
DOI: 10.1097/HC9.0000000000000124 -
Frontiers in Immunology 2023Vitamin A has long been associated with bladder cancer, and many exogenous vitamin A supplements, vitamin A derivatives, and synthetic drugs have been investigated over... (Review)
Review
Vitamin A has long been associated with bladder cancer, and many exogenous vitamin A supplements, vitamin A derivatives, and synthetic drugs have been investigated over the years. However, the effectiveness of these strategies in clinical practice has not met expectations, and they have not been widely adopted. Recent medical research on intestinal flora has revealed that bladder cancer patients exhibit reduced serum vitamin A levels and an imbalance of gut microbiota. In light of the close relationship between gut microbiota and vitamin A, one can speculate that a complex regulatory mechanism exists between the two in the development and occurrence of bladder cancer. As such, further exploration of their interaction in bladder cancer may help guide the use of vitamin A for preventive purposes. During the course of this review, attention is paid to the influence of intestinal microbiota on the vitamin A metabolism and the RA signaling pathway, as well as the mutual promotion relationships between them in the prevention of bladder cancer, In addition, it emphasizes the importance of intestinal microbiota for bladder cancer prevention and treatment.
Topics: Humans; Gastrointestinal Microbiome; Vitamin A; Urinary Bladder Neoplasms; Biomedical Research; Dietary Supplements
PubMed: 37711628
DOI: 10.3389/fimmu.2023.1252616 -
Sichuan Da Xue Xue Bao. Yi Xue Ban =... Jan 2023Keeping the immune system healthy forms an effective way to fight infections. Past experience has shown that, in addition to effective interventions including... (Review)
Review
Keeping the immune system healthy forms an effective way to fight infections. Past experience has shown that, in addition to effective interventions including vaccination, drug therapy, and non-pharmaceutical intervention (NPI), dietary nutrition and mental health are also key factors in maintaining immune system health and combating emerging and sudden outbreaks of infections. As the main dietary nutrients, vitamins are active regulators of the immune response and exert a critical impact on the immunity of the human body. Vitamin deficiency causes increased levels of inflammation and decreased immunity, which usually starts in the oral tissues. Appropriate vitamin supplementation can help the body optimize immune function, enhance oral immunity, and reduce the negative impact of pathogen infection on the human body, which makes it a feasible, effective, and universally applicable anti-infection solution. This review focuses on the immunomodulatory effects of vitamin A, B, C, D, and E and proposes that an omics-based new systemic approach will lead to a breakthrough of the limitations in traditional single-factor single-pathway research and provide the direction for the basic and applied research of vitamin immune regulation and anti-infection in all aspects.
Topics: Humans; Vitamins; Vitamin A; Immune System; Vitamin K; Inflammation; Dietary Supplements
PubMed: 36647636
DOI: 10.12182/20230160107 -
International Journal of Molecular... May 2023Vitamin A ensures intestinal homeostasis, impacting acquired immunity and epithelial barrier function; however, its role in innate immunity is mostly unknown. Here, we...
Vitamin A ensures intestinal homeostasis, impacting acquired immunity and epithelial barrier function; however, its role in innate immunity is mostly unknown. Here, we studied the impact of vitamin A in different dextran sulfate sodium (DSS)-induced colitis animal models. Interestingly, more severe DSS-induced colitis was observed in vitamin A-deficient (VAD) mice than in vitamin A-sufficient (VAS) mice; the same was observed in VAD severe combined immunodeficient mice lacking T/B cells. Remarkably, IL-1β production, LC3B-II expression, and inflammasome activity in the lamina propria were significantly elevated in VAD mice. Electron microscopy revealed numerous swollen mitochondria with severely disrupted cristae. In vitro, non-canonical inflammasome signaling-induced pyroptosis, LC3B-II and p62 expression, and mitochondrial superoxide levels were increased in murine macrophages (RAW 264.7) pretreated with retinoic acid receptor antagonist (Ro41-5253). These findings suggest that vitamin A plays a crucial role in the efficient fusion of autophagosomes with lysosomes in colitis.
Topics: Animals; Mice; Inflammasomes; Vitamin A; Dextran Sulfate; Colitis; Lysosomes; Mice, Inbred C57BL; Disease Models, Animal
PubMed: 37240022
DOI: 10.3390/ijms24108684