Illuminating the Role of Vitamin A in Skin Innate Immunity and the Skin Microbiome: A Narrative Review

Effects of Dietary Vitamin A on the Growth Performance, Nonspecific Immune Response, Shell Microbiota and Red Spotted Disease Resistance of Juvenile Sea Urchin (Strongylocentrotus intermedius)

A 114-day feeding trial was used to investigate the influence of vitamin A (VA) on growth performance, nonspecific immune responses and shell microbiota in juvenile sea urchin (Strongylocentrotus intermedius). Graded levels of VA (0, 4000, 8000, 16,000, 32,000 and 64,000 IU/kg) were added to make six experimental feeds. Each feed was allocated to three parallel tanks of sea urchins (initial weight 0.87 ± 0.05 g and initial test diameter 1.83 ± 0.57 mm). The data revealed that the weight gain rate (WGR) and gonadosomatic index (GSI) rose markedly as VA addition level increased from 0 to 4000 IU/kg and then reached a plateau with further increase of dietary VA levels. As VA addition level increased, nonspecific immune response of S. intermedius first increased and then decreased, with those fed diets with relatively higher addition of VA (32,000 IU/kg) exhibiting significantly greater phagocytic activity (PA) and acid phosphatase (ACP) activities, as well as upregulated expression of several immune-related genes such as tumour necrosis factor α (TNF-α), antimicrobial peptides (AMPs), toll-like receptors (TLRs) and lysozyme (LYZ). The abundance of Firmicutes, Bacteroidota, Bacteroides and Faecalibacterium increased, but that of Proteobacteria and Leucothrix decreased in the shell of S. intermedius as VA addition level increased. The percentage of sea urchins with severe red spotted disease decreased from 64.44% to13.33% as VA addition level increased to 32,000 IU/kg and subsequently increased to 42.22% with further increase of VA addition level. On the contrary, the percentage of sea urchins with mild red spotted disease increased from13.33% to 55.55% as VA addition level increased to 32,000 IU/kg and subsequently decreased to 31.11% with further increase of VA addition level. These results demonstrated that a low addition level of VA (4000 IU/kg) can help S. intermedius achieve ideal growth performance. However, relatively higher addition levels of VA (32,000 IU/kg) enhanced nonspecific immunity and red spotted disease resistance of S. intermedius, which could be accomplished by promoting immune gene expression and optimizing the shell microbiota composition.

The association between serum vitamin A concentrations and virus hepatitis among U.S. adults from the NHANES database: a cross-sectional study

Objective

According to the present study, the relationship between vitamin A (VA) levels and hepatitis virus carriage has been unclear and controversial. This study aimed to determine the potential relationship between serum VA levels and viral hepatitis and to provide ideas for future clinical treatments.

Methods

A cross-sectional study was performed using the 2005-2006 and 2017-2018 National Health and Nutrition Examination Survey (NHANES) datasets. Multiple linear regression and logistic regression were adopted to analyze the association between serological hepatitis B surface antigen (HBsAg) or hepatitis C RNA (HCV-RNA) positivity and VA levels. There were 5,351 HBsAg-related responders and 242 HCV-RNA-related responders, including 52 HBsAg (+) and 104 HCV-RNA (+) responders.

Results

Compared with HBsAg (-) and HCV-RNA (-) respondents, HBsAg (+) and HCV-RNA (+) respondents tended to have lower serum VA levels, respectively [1.63 (1.33 ~ 2.01) vs. 1.92 (1.57 ~ 2.34), P < 0.001; 1.54 (1.25 ~ 1.83) vs. 1.78 (1.46 ~ 2.26), P < 0.001]. A greater percentage of responders in the subclinical VA deficiency (SVAD) group were HBsAg (+) and HCV-RNA (+) than were those in the normal VA (VAN) group [2.4% (9/374) vs. 0.9% (43/4977), p = 0.003; 61.5% (16/26) vs. 40.7% (88/215), p = 0.043]. According to the results of the multiple regression analyses of the different models, the serum VA concentration was negatively correlated with HBsAg (+) and HCV-RNA (+) status (β = -0.14, 95% CI = -0.30 to -0.01, p = 0.066; β = -0.29, 95% CI = -0.50 ~ -0.09, p = 0.005, respectively). Compared to those with SVAD, patients with VAN were less likely to be serologically HBsAg (+) or HCV-RNA (+) (OR = 0.53, 95% CI = 0.25 ~ 1.10, p = 0.089; OR = 0.39, 95% CI = 0.18 ~ 0.84, p = 0.016, respectively).

Conclusion

Our study provides evidence that patients who are HBsAg (+) or HCV-RNA (+) have a high incidence of SVAD. Moreover, HBsAg and HCV-RNA positivity are negatively correlated with VA levels, and patients with SVAD are more likely to carry HBsAg (+) or HCV-RNA (+). These findings suggest that the relationship between hepatitis viruses and vitamin A needs to be validated by more basic studies and clinical large-sample randomized controlled trials to provide ideas for new therapeutic targets.

The Effect of Retinoic Acid on Neutrophil Innate Immune Interactions With Cutaneous Bacterial Pathogens

Vitamin A and its biologically active derivative, retinoic acid (RA), are important for many immune processes. RA, in particular, is essential for the development of immune cells, including neutrophils, which serve as a front-line defense against infection. While vitamin A deficiency has been linked to higher susceptibility to infections, the precise role of vitamin A/RA in host-pathogen interactions remains poorly understood. Here, we provided evidence that RA boosts neutrophil killing of methicillin-resistant Staphylococcus aureus (MRSA). RA treatment stimulated primary human neutrophils to produce reactive oxygen species, neutrophil extracellular traps, and the antimicrobial peptide cathelicidin (LL-37). Because RA treatment was insufficient to reduce MRSA burden in an in vivo murine model of skin infection, we expanded our analysis to other infectious agents. RA did not affect the growth of a number of common bacterial pathogens, including MRSA, Escherichia coli K1 and Pseudomonas aeruginosa; however, RA directly inhibited the growth of group A Streptococcus (GAS). This antimicrobial effect, likely in combination with RA-mediated neutrophil boosting, resulted in substantial GAS killing in neutrophil killing assays conducted in the presence of RA. Furthermore, in a murine model of GAS skin infection, topical RA treatment showed therapeutic potential by reducing both skin lesion size and bacterial burden. These findings suggest that RA may hold promise as a therapeutic agent against GAS and perhaps other clinically significant human pathogens.

Pet Wellness and Vitamin A: A Narrative Overview

The health of companion animals, particularly dogs and cats, is significantly influenced by nutrition, with vitamins playing a crucial role. Vitamin A, in particular, is indispensable, with diverse roles ranging from vision to immune modulation and reproduction. Despite its importance, the metabolism and dietary requirements of vitamin A in companion animals remain complex and not fully understood. This review provides a comprehensive overview of the historical perspective, the digestion, the metabolism, the physiological roles, the deficiency, the excess, and the interactions with other micronutrients of vitamin A in companion animals. Additionally, it highlights future research directions and gaps in our understanding. Insights into the metabolism of vitamin A in companion animals, personalized nutrition strategies based on genetic variability, longitudinal studies tracking the status of vitamin A, and investigations into its immunomodulatory effects are crucial for optimizing pet health and wellness. Furthermore, understanding the stability and bioavailability of vitamin A in pet food formulations is essential for ensuring the provision of adequate micronutrients. Overall, this review underscores the importance of vitamin A in companion animal nutrition and the need for further research to enhance our understanding and to optimize dietary recommendations for pet health and well-being.

Nutritional Supplements for Skin Health-A Review of What Should Be Chosen and Why

Supplementation of micronutrients is considered to be crucial in the reinforcement of the skin's barrier. In this paper, 14 nutritional compounds commonly used in food or pharmaceutic industries were analyzed in terms of influencing skin conditions. The major objective of this paper was to provide a narrative review of the available literature regarding several chosen compounds that are currently widely recommended as supplements that aim to maintain proper and healthy skin conditions. We conducted a review of the literature from PubMed, Scopus, and Web of Science until September 2023 without any other restrictions regarding the year of the publication. Ultimately, we reviewed 238 articles, including them in this review. Each of the reviewed compounds, including vitamin A, vitamin C, vitamin D, vitamin E, curcumin, chlorella, Omega-3, biotin,Ppolypodium leucotomos, Simmondsia chinesis, gamma oryzanol, olive leaf extract, spirulina, and astaxanthin, was observed to present some possible effects with promising benefits for a skin condition, i.e., photoprotective radiation. Adding them to the diet or daily routine might have a positive influence on some skin inflammatory diseases such as atopic dermatitis or psoriasis. Further, UV radiation protection facilitated by some supplements and their impact on human cells might be helpful during chemotherapy or in preventing melanoma development. Further research is needed because of the lack of clear consensus regarding the doses of the described compounds that could provide desirable effects on the skin.

Modulatory role of vitamins A, B3, C, D, and E on skin health, immunity, microbiome, and diseases

Disruption of the skin barrier and immunity has been associated with several skin diseases, namely atopic dermatitis (AD), psoriasis, and acne. Resident and non-resident immune cells and the barrier system of the skin are integral to innate immunity. Recent advances in understanding skin microbiota have opened the scope of further understanding the various communications between these microbiota and skin immune cells. Vitamins, being one of the important micronutrients, have been reported to exert antioxidant, anti-inflammatory, and anti-microbial effects. The immunomodulatory action of vitamins can halt the progression of skin diseases, and thus, understanding the immuno-pharmacology of these vitamins, especially for skin diseases can pave the way for their therapeutic potential. At the same time, molecular and cellular markers modulated with these vitamins and their derivatives need to be explored. The present review is focused on significant vitamins (vitamins A, B3, C, D, and E) consumed as nutritional supplements to discuss the outcomes and scope of studies related to skin immunity, health, and diseases.

Viruses and autism: A Bi-mutual cause and effect

Autism spectrum disorder (ASD) is a group of heterogeneous, multi-factorial, neurodevelopmental disorders resulting from genetic and environmental factors interplay. Infection is a significant trigger of autism, especially during the critical developmental period. There is a strong interplay between the viral infection as a trigger and a result of ASD. We aim to highlight the mutual relationship between autism and viruses. We performed a thorough literature review and included 158 research in this review. Most of the literature agreed on the possible effects of the viral infection during the critical period of development on the risk of developing autism, especially for specific viral infections such as Rubella, Cytomegalovirus, Herpes Simplex virus, Varicella Zoster Virus, Influenza virus, Zika virus, and severe acute respiratory syndrome coronavirus 2. Viral infection directly infects the brain, triggers immune activation, induces epigenetic changes, and raises the risks of having a child with autism. At the same time, there is some evidence of increased risk of infection, including viral infections in children with autism, due to lots of factors. There is an increased risk of developing autism with a specific viral infection during the early developmental period and an increased risk of viral infections in children with autism. In addition, children with autism are at increased risk of infection, including viruses. Every effort should be made to prevent maternal and early-life infections and reduce the risk of autism. Immune modulation of children with autism should be considered to reduce the risk of infection.

How to Promote Skin Repair? In-Depth Look at Pharmaceutical and Cosmetic Strategies

Skin repair encompasses epidermal barrier repair and wound healing which involves multiple cellular and molecular stages. Therefore, many skin repair strategies have been proposed. In order to characterize the usage frequency of skin repair ingredients in cosmetics, medicines, and medical devices, commercialized in Portuguese pharmacies and parapharmacies, a comprehensive analysis of the products' composition was performed. A total of 120 cosmetic products, collected from national pharmacies online platforms, 21 topical medicines, and 46 medical devices, collected from INFARMED database, were included in the study, revealing the top 10 most used skin repair ingredients in these categories. A critical review regarding the effectiveness of the top ingredients was performed and an in-depth analysis focused on the top three skin repair ingredients pursued. Results demonstrated that top three most used cosmetic ingredients were metal salts and oxides (78.3%), vitamin E and its derivatives (54.2%), and Centella asiatica (L.) Urb. extract and actives (35.8%). Regarding medicines, metal salts and oxides were also the most used (47.4%) followed by vitamin B5 and derivatives (23.8%), and vitamin A and derivatives (26.3%). Silicones and derivatives were the most common skin repair ingredients in medical devices (33%), followed by petrolatum and derivatives (22%) and alginate (15%). This work provides an overview of the most used skin repair ingredients, highlighting their different mechanisms of action, aiming to provide an up-to-date tool to support health professionals' decisions.

Staphylococcus aureus-derived factors promote human Th9 cell polarization and enhance a transcriptional program associated with allergic inflammation

T helper (Th) 9 cells, characterized by robust secretion of IL-9, have been increasingly associated with allergic diseases. However, whether and how Th9 cells are modulated by environmental stimuli remains poorly understood. In this study, we show that in vitro exposure of human PBMCs or isolated CD4 T-cells to Staphylococcus (S.) aureus-derived factors, including its toxins, potently enhances Th9 cell frequency and IL-9 secretion. Furthermore, as revealed by RNA sequencing analysis, S. aureus increases the expression of Th9-promoting factors at the transcriptional level, such as FOXO1, miR-155, and TNFRSF4. The addition of retinoic acid (RA) dampens the Th9 responses promoted by S. aureus and substantially changes the transcriptional program induced by this bacterium, while also altering the expression of genes associated with allergic inflammation. Together, our results demonstrate a strong influence of microbial and dietary factors on Th9 cell polarization, which may be important in the context of allergy development and treatment.

Delivery and diffusion of retinal in dermis and epidermis through the combination of prodrug nanoparticles and detachable dissolvable microneedles

To minimize chemical degradation of retinal, we graft this aldehyde on chitosan chains to make them self-assemble into pro-retinal nanoparticles (PRNs), which we then load into detachable dissolvable microneedles (DDMNs) made of 1:1 (by weight) hyaluronic acid/maltose. The presence of PRNs in the hyaluronic acid-maltose needle matrix also helps improve the microneedles' mechanical strength. Ex vivo administration of PRN-loaded DDMNs on fresh porcine ear skin shows, as observed by stereomicroscopic and confocal fluorescence microscopic analyses of the cross-sectioned tissue pieces, complete deposition followed by dissolution of the needles and diffusion of the PRNs in epidermis and dermis. Rats administered with a single dose of PRN-loaded DDMNs show significantly increased epidermal thickness as compared to rats administered with control DDMNs (no PRN). Both the PRN-loaded DDMNs and the control DDMNs produce no skin irritation in rats.

Dietary Zinc Intake Affects the Association Between Dietary Vitamin A and Depression: A Cross-Sectional Study

Introduction

Dietary vitamin A concentrations correlate with depression. Zinc has been reported to be associated with lower depression. In addition, zinc is an important cofactor in the activation of vitamin A. However, there are few studies investigating relationships between of dietary zinc intake, dietary vitamin A intake and depression.

Materials and Methods

The data for this study came from the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2018 and involved 70,190 participants. We stratified participants by recommended dietary zinc intake (recommended dietary zinc intake for women: 8 mg/day, recommended dietary zinc intake for men: 11 mg/day). We further assessed the association between vitamin A and depression in participants with low and high zinc intake (interaction test) using univariate logistic regression of intake participants.

Result

In the female population we grouped the population into low and high zinc intake groups using the recommended dietary zinc intake of 8 (mg/day), with an increase in total vitamin A, the risk of depression was significantly lower in the low zinc intake group (OR: 0.85 95 CI: 0.76–0.96), while the risk of depression was increased in the high zinc intake group (OR: 1.05 95 CI: 0.95 to 1.17). Thus, in the female population, there was a significant interaction between insufficient vitamin an intake and depression (interaction likelihood ratio test of p = 0.011). In the male population we grouped the population by the recommended dietary zinc intake of 11(mg/day). Again, the population was divided into two groups with low and high zinc intake, however we did not find significant results for the interaction (p = 0.743 for the interaction likelihood ratio test).

Conclusion

Our findings suggest that zinc intake may influence the relationship between dietary vitamin A and depression. Of course, our findings require further randomized controlled trials to enhance the credibility.

Insight Into Biological Targets and Molecular Mechanisms in the Treatment of Arsenic-Related Dermatitis With Vitamin A via Integrated in silico Approach

Exposure to arsenic (As), an inorganic poison, may lead to skin lesions, including dermatitis. Vitamin A (VA), a fat-soluble vitamin essential for mucous membrane integrity, plays a key role in skin protection. Although the beneficial actions of VA are known, the anti-As-related dermatitis effects of VA action remain unclear. Hence, in this study, we aimed to interpret and identify the core target genes and therapeutic mechanisms of VA action in the treatment of As-related dermatitis through integrated in silico approaches of network pharmacology and molecular docking. We integrated the key VA-biological target-signaling pathway-As-related dermatitis networks for identifying core drug targets and interaction pathways associated with VA action. The network pharmacology data indicated that VA may possess potential activity for treating As-related dermatitis through the effective regulation of core target genes. An enrichment analysis in biological processes further revealed multiple immunoregulation-associated functions, including interferon-gamma production and negative regulation of T-cell activation and production of molecular mediator of immune response. An enrichment analysis in molecular pathways mainly uncovered multiple biological signaling, including natural killer cell mediated cytotoxicity, autophagy, apoptosis, necroptosis, platelet activation involved in cell fate, and immunity regulations. Molecular docking study was used to identify docked well core target proteins with VA, including Jun, tumor protein p53 (TP53), mitogen-activated protein kinase-3 (MAPK3), MAPK1, and MAPK14. In conclusion, the potential use of VA may suppress the inflammatory stress and enhance the immunity against As-related dermatitis. In the future, VA might be useful in the treatment of dermatitis associated with As through multi-targets and multi-pathways in clinical practice.

Novel mechanisms of microbial crosstalk with skin innate immunity

Skin is an organ with a dynamic ecosystem that harbours pathogenic and commensal microbes, which constantly communicate amongst each other and with the host immune system. Evolutionarily, skin and its microbiota have evolved to remain in homeostasis. However, frequently this homeostatic relationship is disturbed by a variety of factors such as environmental stress, diet, genetic mutations, and the microbiome itself. Commensal microbes also play a major role in the maintenance of microbial homeostasis. In addition to their ability to limit pathogens, many skin commensals such as Staphylococcus epidermidis and Cutibacterium acnes have recently been implicated in disease pathogenesis either by directly modulating the host immune components or by supporting the expansion of other pathogenic microbes. Likewise, opportunistic skin pathogens such as Staphylococcus aureus and Staphylococcus lugdunensis are able to breach the skin and cause disease. Though much has been established about the microbiota's function in skin immunity, we are in a time where newer mechanistic insights rapidly redefine our understanding of the host/microbial interface in the skin. In this review, we provide a concise summary of recent advances in our understanding of the interplay between host defense strategies and the skin microbiota.