Ascorbic acid, ultraviolet C rays, and glucose but not hyperthermia are elicitors of human β-defensin 1 mRNA in normal keratinocytes

The effect of vitamin C on oxidative stress indices and skin regimentation of vitiligo patients

It has been suggested that vitamin C is involved in suppressing stress oxidation signaling in vitiligo disease. However, the effect of vitamin C supplementation on stress oxidative factors has not been investigated in vitiligo subjects. This study was designed to examine the effects on vitamin C supplementation on serum levels of stress oxidative factors and regimentation in vitiligo patients. Forty-four vitiligo patients will be recruited in this study. After block matching for sex and number of phototherapy sessions, they will be randomly assigned to receive 1000 mg/d vitamin C or placebo for 8 weeks. The weight, height, and waist circumference of participants will be measured. Determination of serum stress oxidative indices (CAT, SOD, GPX, MDA, TOS, TAC) will be done at study baseline and at the end of the trial. Also, the regimentation will be determined using the VASI score. This is the first randomized controlled trial that will determine the effect of vitamin C supplementation on serum levels of stress oxidative indices and regimentation in vitiligo patients. The results of this trial will provide clinical evidence on the effectiveness of vitamin C supplementation in controlling oxidative stress in vitiligo patients. Trial registration number: This study is registered in the Iranian Registry of Clinical Trials website (available at http://www.irct.ir , identifier: IRCT20230123057193N1), Registration date: 2023/04/17.

Cytomegalovirus seropositivity correlates with both human β-defensin 1 and IFN-γ downregulation in women with obesity

Human β-defensin 1 (hBD-1) is a constitutively expressed antimicrobial peptide with antiviral properties. CMV seropositivity has been associated with obesity. It is unknown if hBD-1 levels of are altered in women with obesity and/or CMV seropositivity. In a pilot project of 31 adult women with CMV seropositivity, we calculated the correlation among hBD-1 serum levels (ELISA) and IgG anti-CMV-Index with anthropometric measurements, lipid profiles and glucose levels. hBD-1 showed negative correlation with triglycerides (TG) (r = -0.617; p = 0.033,) and hip circumference (r = -0.596; p = 0.041,). IgG anti-CMV index was negatively correlated with hBD-1 levels and positively correlated with TG (r = 0.702; p = 0.011,) and HC (r = 0.583; p = 0.047,) in women with obesity. As expected, hBD-1 levels correlates with IFN-γ (an antimicrobial peptide elicitor) in the three analyzed groups.These results shows that CMV seropositivity correlates with both IFN-γ levels and hBD-1 levels which in contrast with non-CMV seropositivity scenario, is commonly found an IFN-γ upregulation in individuals with obesity. Further research is encouraged to test if CMV is causing the observed downregulation of the antiviral immune responses of both hBD-1 and IFN-γ as well as their involved mechanisms.

Synergistic Induction of Chicken Antimicrobial Host Defense Peptide Gene Expression by Butyrate and Sugars

Antimicrobial resistance is a major concern to public health demanding effective alternative strategies to disease control and prevention. Modulation of endogenous host defense peptide (HDP) synthesis has emerged as a promising antibiotic alternative approach. This study investigated a potential synergy between sugars and butyrate in inducing HDP gene expression in chickens. Our results revealed that sugars differentially regulated HDP expression in both gene- and sugar-specific manners in chicken HD11 macrophage cells. Among eight mono- and disaccharides tested, all were potent inducers of avian β-defensin 9 (AvBD9) gene (p<0.05), but only galactose, trehalose, and lactose obviously upregulated cathelicidin-B1 (CATHB1) gene expression. The expression of AvBD14 gene, on the other hand, was minimally influenced by sugars. Moreover, all sugars exhibited a strong synergy with butyrate in enhancing AvBD9 expression, while only galactose, trehalose, and lactose were synergistic with butyrate in CATHB1 induction. No synergy in AvBD14 induction was observed between sugars and butyrate. Although lactose augmented the expression of nearly all HDP genes, its synergy with butyrate was only seen with several, but not all, HDP genes. Mucin-2 gene was also synergistically induced by a combination of lactose and butyrate. Furthermore, lactose synergized with butyrate to induce AvBD9 expression in chicken jejunal explants (p<0.05). Mechanistically, hyper-acetylation of histones was observed in response to both butyrate and lactose, relative to individual compounds. Mitogen-activated protein kinase, NF-κB, and cyclic adenosine monophosphate signaling pathways were also found to be involved in butyrate- and lactose-mediated synergy in AvBD9 induction. Collectively, a combination of butyrate and a sugar with both HDP-inducing and barrier protective activities holds the promise to be developed as an alternative to antibiotics for disease control and prevention.

Retinoic acid induces antimicrobial peptides and cytokines leading to Mycobacterium tuberculosis elimination in airway epithelial cells

Tuberculosis (TB) is the leading cause of death by a single infectious agent, Mycobacterium tuberculosis (Mtb). Alveolar macrophages and respiratory epithelial cells are the first cells exposed to Mtb during the primary infection, once these cells are activated, secrete cytokines and antimicrobial peptides that are associated with the Mtb contention and elimination. Vitamins are micronutrients that function as boosters on the innate immune system, however, is unclear whether they have any protective activity during Mtb infection. Thus, we investigated the role of vitamin A (retinoic acid), vitamin C (ascorbic acid), vitamin D (calcitriol), and vitamin E (alfa-tocopherol) as inductors of molecules related to mycobacterial infection in macrophages and epithelial cells. Our results showed that retinoic acid promotes the expression of pro- and anti-inflammatory molecules such as Thymic stromal lymphopoietin (TSLP), β-defensin-2, IL-1β, CCL20, β-defensin-3, Cathelicidin LL-37, TGF-β, and RNase 7, whereas calcitriol, ascorbic acid, and α-tocopherol lead to an anti-inflammatory response. Treatment of Mtb-infected epithelial cells and macrophage-like cells with the vitamins showed a differential response, where calcitriol reduced Mtb in macrophages, while retinoic acid reduced infection in epithelial cells. Thereby, we propose that a combination of calcitriol and retinoic acid supplementation can drive the immune response, and promotes the Mtb elimination by increasing the expression of antimicrobial peptides and cytokines, while simultaneously modulating inflammation.

β-defensin 1 Gene Polymorphisms are Associated with Kidney Disease in Northwestern Mexicans with Type 2 Diabetes

Diabetic kidney disease (DKD) is one of the more limiting complications to the quality of life of diabetes mellitus patients. Studies including cultured cells, animal models, and case-control studies highlight the role of human β-defensin-1 (hBD-1) in diabetes.This study assessed the association of hBD-1 gene (DEFB1) functional variations -52 G/A (rs1799946), -44 C/G (rs1800972) and -20 G/A (rs11362) with type 2 diabetes mellitus (T2DM) in order to investigate its effects on genetic susceptibility and progression to DKD in a Mexican population. A total of 214 T2DM patients with and without DKD (n = 102 and n = 112, respectively) and 117 healthy subjects participated in this case-control study. Genotyping was made by PCR-RFLPs. Clinical and biochemical parameters of all patients were measured. There was no statistically significant difference in genotype or allele frequencies between patients and healthy individuals. Nevertheless, compared with patients without DKD, DKD patients have a reduced prevalence of AA genotype of -52 G/A (OR = 0.307, 95% CI = 0.104-0.905, p =.026), as well as a higher frequency of GA genotype of -20 G/A variant (OR = 1.875, 95%CI = 1.031-3.409, p = .038). Our results suggest that rs1799946 and rs11362 could be useful variants to stratify T2DM Mexican patients in order to prescribe closer follow-up to prevent or retard DKD. Further tests in different ethnic groups are encouraged.

The effect of Vitamin C on melanin pigmentation - A systematic review

Vitamin C, also known as ascorbic acid, is used as a treatment modality in depigmentation of hyperpigmented spots on the skin and gingiva. This systematic review discusses the studies conducted to assess the effect of Vitamin C on melanin pigmentation. The primary objective was to evaluate the effect of Vitamin C on melanin pigmentation. The secondary objective was to analyze the effect of Vitamin C administration on melanin pigmentation. An electronic database search was conducted from the following databases: PubMed, EBSCOhost, ScienceOpen, EMBASE and Google Scholar. Randomized controlled trials, experimental studies, case-control studies and cohort studies published in peer-reviewed journals in English language were included. Case reports, case series, animal model studies, in vitro studies, studies where Vitamin C was used along with other agents and unpublished research were excluded. Out of 22,580 studies, only 7 studies satisfied the selection criteria. Data extraction sheet was prepared, and the studies were analyzed. Out of the 7 studies analyzed, 1 was a randomized controlled trial and 6 were experimental studies. Vitamin C has been used widely as a depigmenting agent in dermatology. However, there are limited studies conducted on the use of Vitamin C for gingival depigmentation.

Defensins: Transcriptional regulation and function beyond antimicrobial activity

Defensins are one the largest group of antimicrobial peptides and are part of the innate defence. Defensins are produced by animals, plants and fungi. In animals and plants, defensins can be constitutively or differentially expressed both locally or systemically which confer defence before and a stronger response after infection. Immune signalling pathways regulate the gene expression of defensins. These pathways include cellular receptors, which recognise pathogen-associated molecular patterns and are found both in plants and animals. After recognition, signalling pathways and, subsequently, transcriptional factors are activated. There is an increasing number of novel functions in defensins, such as immunomodulators and immune cell attractors. Identification of defensin triggers could help us to elucidate other new functions. The present article reviews the different elicitors of defensins with a main focus on human, fish and marine invertebrate defensins.

Regulatory SNP rs5743417 impairs constitutive expression of human β-defensin 1 and has high frequency in Africans and Afro-Americans

The prediction of regulatory single nucleotide polymorphisms (rSNPs) in proximal promoters of disease-related genes could be a useful tool for personalized medicine in both patient stratification and customized therapy. Using our previously reported method of rSNPs prediction (currently a software called SNPClinic v.1.0) as well as with PredictSNP tool, we performed in silico prediction of regulatory SNPs in the antimicrobial peptide human β-defensin 1 gene in three human cell lines from 1,000 Genomes Project (1kGP), namely A549 (epithelial cell line), HL-60 (neutrophils) and T_H 1 (lymphocytes). These predictions were run in a proximal pseudo-promoter comprising all common alleles on each polymorphic site according to the 1,000 Genomes Project data (1kGP: ALL). Plasmid vectors containing either the major or the minor allele of a putative rSNP rs5743417 (categorized as regulatory by SNPClinic and confirmed by PredictSNP) and a non-rSNP negative control were transfected to lung A549 human epithelial cell line. We assessed functionality of rSNPs by qPCR using the Pfaffl method. In A549 cells, minor allele of the SNP rs5743417 G→A showed a significant reduction in gene expression, diminishing DEFB1 transcription by 33% when compared with the G major allele (p-value = .03). SNP rs5743417 minor allele has high frequency in Gambians (8%, 1kGP population: GWD) and Afro-Americans (3.3%, 1kGP population: ASW). This SNP alters three transcription factors binding sites (TFBSs) comprising SREBP2 (sterols and haematopoietic pathways), CREB1 (cAMP, insulin and TNF pathways) and JUND (apoptosis, senescence and stress pathways) in the proximal promoter of DEFB1. Further in silico analysis reveals that this SNP also overlaps with GS1-24F4.2, a lincRNA gene complementary to the X Kell blood group related 5 (XKR5) mRNA. The potential clinical impact of the altered constitutive expression of DEFB1 caused by rSNP rs5743417 in DEFB1-associated diseases as tuberculosis, COPD, asthma, cystic fibrosis and cancer in African and Afro-American populations deserves further research.

Human β-defensin 1 update: Potential clinical applications of the restless warrior

Human β-defensin 1 (hBD-1) is a multifaceted antimicrobial peptide being a tumour suppressor and, depending on call of duty, capable of inducing self-nets and neutrophil extracellular traps (NETs) to capture and/or kill bacteria, participates in inflammatory responses in chronic diseases including hBD-3 upregulation and also capable of up/downregulation in the presence of certain species of Lactobacillus sp. Thus, is regulated by host microbiota. Alleles, genotypes and/or altered gene expression of its coding gene, DEFB1, have been associated with several human diseases/conditions ranging from metabolic/chronic (e.g. cancer), infectious (e.g. tuberculosis, HIV/AIDS), inflammatory (gastrointestinal diseases), male infertility and more recently, neurologic (e.g. depression and Alzheimer) and autoimmune diseases (e.g. vitiligo and systemic lupus erythematosus). The present update focuses on novel DEFB1/hBD-1 properties and biomarker features, its biological function and the pharmaceutical potential uses of antimicrobial peptide elicitors (APEs) or the engineered peptide in the treatment of hBD-1-related human diseases.

Troxerutin protect sperm, seminiferous epithelium and pituitary-gonadal axis from torsion-detorsion injury: An experimental study

BACKGROUND

Troxerutin is a flavonoid antioxidant that protect different organ against damage caused by ischemia-reperfusion.

OBJECTIVE

The aim of this study was to evaluate the effect of troxerutin in reducing the damages caused by ischemia-reperfusion in rat's testis.

MATERIALS AND METHODS

40 Male Wistar rats (2 month old) were divide to four groups (n=10). Group1 (sham), Group 2 (control, ischemia-reperfusion (I/R) without treatment), Group 3 (I/R+150 mg/kg of troxerutin), and group 4 (I/R+20 mg/kg of vitamin C). Treatment of group 3 and group 4 during torsion (twists 720 counter clock at 90 min) followed by 50 days detorsion. After 50 days, blood samples were collected and rats in all study groups were killed and their testes were removed, and fixed with Bouin's solution. Testis was stained with hematoxylin and eosin dye and the level of testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured with ELISEA methods. TUNEL was employed to detect apoptosis. Epididymis caudal part was removed and total sperm count was determined. Johnson techniques were used for assessment of seminiferous tubules quality.

RESULTS

Troxerutin treated group has higher Johnson score's (p≤0.001), antiapoptotic properties (p≤0.001), sperm count (p=0.065), and higher LH (p≤0.001), FSH (p≤0.001) and testosterone (p=0.002) levels than control group. Vitamin C treated group showed increase level of testosterone but didn't show significant differences on the number of apoptotic cells, Johnson scores, LH, FSH and sperm count than control group.

CONCLUSION

Troxerutin has protective effects on testicular torsion induced injury and can ameliorate spermatogenesis in the torsion-detorsion models.

High-glucose environment disturbs the physiologic functions of keratinocytes: Focusing on diabetic wound healing

Impaired wound healing is a common and potentially serious complication in patients with diabetes. In recent years, disturbed physiologic functions of epidermal keratinocytes have been found to play a central role in the poor healing ability of diabetic wounds. Factors involving keratinocytes that may contribute to the dysfunctional wound healing process in diabetes include impaired keratinocyte migration and proliferation, gap junction abnormalities, chronic inflammation, chronic infections associated with defective innate immunity, impaired angiogenesis, increased oxidative stress, and abnormal expression of matrix metalloproteinases (MMPs). In this review article, we provide evidence from the scientific literature for the molecular mechanisms of delayed wound healing in diabetes, with particular emphasis on keratinocytes. Elucidating the spectrum of molecular and functional abnormalities in keratinocytes induced by high-glucose environment may lead to more effective and individualized therapeutic strategies for the prevention and management of chronic diabetic wounds.