Human Β-defensin Research Articles

Gold Nanoparticles Combined Human β-Defensin 3 Gene-Modified Human Periodontal Ligament Cells Alleviate Periodontal Destruction via the p38 MAPK Pathway.

Periodontitis is a chronic inflammatory disease with plaques as the initiating factor, which will induce the destruction of periodontal tissues. Numerous studies focused on how to obtain periodontal tissue regeneration in inflammatory environments. Previous studies have reported adenovirus-mediated human β-defensin 3 (hBD3) gene transfer could potentially enhance the osteogenic differentiation of human periodontal ligament cells (hPDLCs) and bone repair in periodontitis. Gold nanoparticles (AuNPs), the ideal inorganic nanomaterials in biomedicine applications, were proved to have synergetic effects with gene transfection. To further observe the potential promoting effects, AuNPs were added to the transfected cells. The results showed the positive effects of osteogenic differentiation while applying AuNPs into hPDLCs transfected by adenovirus encoding hBD3 gene. In vivo, after rat periodontal ligament cell (rPDLC) transplantation into SD rats with periodontitis, AuNPs combined hBD3 gene modification could also promote periodontal regeneration. The p38 mitogen-activated protein kinase (MAPK) pathway was demonstrated to potentially regulate both the in vitro and in vivo processes. In conclusion, AuNPs can promote the osteogenic differentiation of hBD3 gene-modified hPDLCs and periodontal regeneration via the p38 MAPK pathway.

Staphylococcus aureus Carriage in Hidradenitis Suppurativa: Impact on Response to Adalimumab

Background: Several patients with hidradenitis suppurativa (HS) present flare-ups during treatment with adalimumab (ADA), the cause of which is not clear. ADA is the only FDA-approved biologic for the therapy of moderate-to-severe HS. A previous study of our group has shown that Staphylococcus aureus stimulation of whole blood affects the production of human β-defensin 2 and modulates HS severity. It is, therefore, hypothesized, that carriage of S. aureus may drive HS flare-ups. Objective: To explore the association between carriage of S. aureus and loss of response to ADA. Patients and Methods: Among patients with moderate-to-severe HS without carriage of S. aureus at start of treatment with ADA, we investigated for carriage of S. aureus from the nares when flare-ups occurred. Flare-ups were pre-defined as at least 25% increase of inflammatory lesions (sum of inflammatory nodules and abscesses) from baseline. Samplings were also done after completion of 12 weeks of ADA treatment from all patients who did not present flare-ups. Clinical response to ADA was assessed by the HS Clinical Response score (HiSCR). Results: Thirty-nine patients were studied; 24 with Hurley II stage HS and 15 with Hurley III stage HS. Twenty-nine patients achieved HiSCR after 12 weeks of treatment without any flare-ups; 10 patients had flare-ups and failed HiSCR. Three (10.3%) and 5 (50%) patients, respectively, had nasal carriage of S. aureus (odds ratio 8.67; 95% CI 1.54–48.49; p = 0.014). Among 32 patients reaching follow-up week 48, 20 patients achieved HiSCR and 12 had flare-ups leading to ADA failure; 2 (10%) and 5 (41.7%) patients, respectively, had positive culture for S. aureus (odds ratio 6.42; 95% CI 1.00–41.20; p = 0.05). Conclusion: Nasal carriage of S. aureus may be associated with loss of response to ADA. Findings need confirmation in larger series of patients.

What is the performance of novel synovial biomarkers for detecting periprosthetic joint infection in the presence of inflammatory joint disease?

The aim of this study was to further evaluate the accuracy of ten promising synovial biomarkers (bactericidal/permeability-increasing protein (BPI), lactoferrin (LTF), neutrophil gelatinase-associated lipocalin (NGAL), neutrophil elastase 2 (ELA-2), α-defensin, cathelicidin LL-37 (LL-37), human β-defensin (HBD-2), human β-defensin 3 (HBD-3), D-dimer, and procalcitonin (PCT)) for the diagnosis of periprosthetic joint infection (PJI), and to investigate whether inflammatory joint disease (IJD) activity affects their concentration in synovial fluid. We included 50 synovial fluid samples from patients with (n = 25) and without (n = 25) confirmed PJI from an institutional tissue bank collected between May 2015 and December 2016. We also included 22 synovial fluid samples aspirated from patients with active IJD presenting to Department of Rheumatology, the first Medical Centre, Chinese PLA General Hospital. Concentrations of the ten candidate biomarkers were measured in the synovial fluid samples using standard enzyme-linked immunosorbent assays (ELISA). The diagnostic accuracy was evaluated by receiver operating characteristic (ROC) curves. BPI, LTF, NGAL, ELA-2, and α-defensin were well-performing biomarkers for detecting PJI, with areas under the curve (AUCs) of 1.000 (95% confidence interval, 1.000 to 1.000), 1.000 (1.000 to 1.000), 1.000 (1.000 to 1.000), 1.000 (1.000 to 1.000), and 0.998 (0.994 to 1.000), respectively. The other markers (LL-37, HBD-2, D-dimer, PCT, and HBD-3) had limited diagnostic value. For the five well-performing biomarkers, elevated concentrations were observed in patients with active IJD. The original best thresholds determined by the Youden index, which discriminated PJI cases from non-PJI cases could not discriminate PJI cases from active IJD cases, while elevated thresholds resulted in good performance. BPI, LTF, NGAL, ELA-2, and α-defensin demonstrated excellent performance for diagnosing PJI. However, all five markers showed elevated concentrations in patients with IJD activity. For patients with IJD, elevated thresholds should be considered to accurately diagnose PJI. Cite this article: Bone Joint J 2021;103-B(1):32-38.

The content of antimicrobial peptides – human β-defensin 2 and cathelicidin – in the secretion of the mucous membrane of the upper respiratory tract of children with bronchial asthma and allergic rhinitis

The content of antimicrobial peptides – human β-defensin 2 and cathelicidin – in the secretion of the mucous membrane of the upper respiratory tract of children with bronchial asthma and allergic rhinitis

Dupilumab Therapy Improves Stratum Corneum Hydration and Skin Dysbiosis in Patients With Atopic Dermatitis.

PurposeWe aimed to investigate the effects of dupilumab on 1) the permeability and antimicrobial barrier, 2) the composition of the skin microbiome, and 3) the correlation between changes in skin barrier properties and microbiota in atopic dermatitis (AD) patients.MethodsTen patients with severe AD were treated with dupilumab for 12 weeks. Disease severity was assessed using the Eczema Area and Severity Index (EASI). Skin barrier function was evaluated by measuring transepidermal water loss, stratum corneum (SC) hydration, and pH. The following parameters were analyzed in the pre- and post-treatment SC samples; 1) skin microbiota using 16S rRNA gene sequencing, 2) lipid composition using mass spectrometry, and 3) human β-defensin 2 (hBD-2) expression using quantitative reverse transcription polymerase chain reaction.ResultsSC hydration levels in the lesional and non-lesional skin increased after 12-week dupilumab therapy (24.2%, P < 0.001 and 59.9%, P < 0.001, respectively, vs. baseline) and correlated with EASI improvement (r = 0.90, P < 0.001 and r = 0.85, P = 0.003, respectively). Dupilumab increased the long-chain ceramide levels in atopic skin (118.4%, P = 0.028 vs. baseline) that correlated with changes in SC hydration (r = 0.81, P = 0.007) and reduced the elevated hBD-2 messenger RNA levels (−15.4%, P = 0.005 vs. baseline) in the lesional skin. Dupilumab decreased the abundance of Staphylococcus aureus. In contrast, the microbial diversity and the abundance of Cutibacterium and Corynebacterium species increased, which were correlated with an increase in SC hydration levels (Shannon diversity, r = 0.71, P = 0.027; Cutibacterium, r = 0.73, P = 0.017; Corynebacterium, r = 0.75, P = 0.012). Increased abundance of Cutibacterium species was also correlated with EASI improvement (r = 0.68, P = 0.032).ConclusionsTh2 blockade-induced normalization of skin microbiome in AD patients is associated with increased SC hydration.

Interruption of the tricarboxylic acid cycle in Staphylococcus aureus leads to increased tolerance to innate immunity.

Staphylococcus aureus is widely known for its resistance and virulence causing public health concerns. However, antibiotic tolerance is also a contributor to chronic and relapsing infections. Previously, it has been demonstrated that persister formation is dependent on reduced tricarboxylic acid (TCA) cycle activity. Persisters have been extensively examined in terms of antibiotic tolerance but tolerance to antimicrobial peptides (AMPs) remains largely unexplored. AMPs are a key component of both the human and Drosophila innate immune response. TCA cycle mutants were tested to determine both antibiotic and AMP tolerance. Challenging with multiple classes of antibiotics led to increased persister formation (100- to 1,000-fold). Similarly, TCA mutants exhibited AMP tolerance with a 100- to 1,000-fold increase in persister formation when challenged with LL-37 or human β-defensin 3 (hβD3). The ability of TCA cycle mutants to tolerate the innate immune system was further examined with a D. melanogaster model. Both males and females infected with TCA cycle mutants exhibited increased mortality and had higher bacterial burdens (1.5 log) during the course of the infection. These results suggest increasing the percentage of persister cells leads to increased tolerance to components of the innate immune system.

Putative effects of sexual hormones and cytokines in pre and post-menopausal women during bacterial urinary tract infection.

Urinary Tract Infections (UTI) affect mostly females. The infection and possible consequent ascent of bacteria is enhanced by various risk factors. Sex hormones regulate gene transcription implicated in immune cell development and maturation, in regulation of immune responses and immune signaling pathways. This study was designed to determine the relationship between UTI and some sex hormones and role of them in cytokines related to immune response in pre and post-menopausal women during bacterial infection. The study included 90 urine samples from females age (18-69) years: forty five were pre-menopause group subdivided into two groups includes (25 infected with UTI and 20 control subjects) , while others forty five post- menopause group includes (25 infected with UTI and 20 control subjects) were attending to clinic of urology at Salahaldeen hospital and private medical clinic in Tikrit City. Blood samples were collected from these women to determine the concentrations of sex hormones (Estrogen (E2), Progesterone)and cytokines includes (Interleukin10 (IL-10),Transforming Growth Factor-β (TGF-β), Human β-Defensin 2 (HBD2) and Toll-Like Receptor4 (TLR-4) in those Sera, they assaying using ELISA technique assay . The positive isolates were selected for infected females of pre and post-menopausal. Fifty bacterial isolated were isolated from infected women with UTI, and the most frequently isolated microorganisms 27(54%) were Gram-negative bacteria; 15(60%) and 12(48%) pre and post-menopausal respectively, Followed by Gram-positive bacteria 23(46%) isolated; 10(40%) and 13(52%) pre and post-menopausal respectively. According to current research results of urine culture bacterial isolation, the most commonly isolated microorganisms were: Escherichia coli 15(30%) 8(32%), 7(28%) pre and post-menopausal respectively; and Enterobacter fecales in 10(20%) 5(20%), 5(20%) pre and post-menopausal respectively. The most effective antimicrobial agents were Amikacin, Gentamicin and Amoxicillin but the less effective were Ceftriaxone, Norfloxacin, and Nitrofurantoin. The results showed that the concentration of estrogen and progesterone hormones were higher in pre and post-menopausal without UTI (414.0 ± 34.2 pg/ml; 1.589 ± 0.460) pg/ml (406.1 ± 30.71 pg/ml; 1.894 ± 0.292) while decreased in pre and post-menopausal with UTI respectively; and decreased in the levels of IL-10, TGF-β, HBD2 and TLR-4 in a females with UTI pre and post-menopausal when compared without UTI females. The interaction between sex hormones and the incidence, progression and morbidity of UTI may be due to effective role of them at the levels of some cytokines like of IL-10, TGF-β, HBD2 and TLR-4. The ability of sex hormones to increase production of antimicrobial peptides, combined with the effect on epithelial integrity or distribution of proteins associated with cell-cell contact, to mention a few, place them as possible candidates for supportive treatment of UTI.

Antimicrobial peptides: bridging innate and adaptive immunity in the pathogenesis of psoriasis.

Antimicrobial peptides (AMPs) are small molecules produced by a myriad of cells and play important roles not only in protecting against infections and sustaining skin barrier homeostasis but also in contributing to immune dysregulation under pathological conditions. Recently, increasing evidence has indicated that AMPs, including cathelicidin (LL-37), human β-defensins, S100 proteins, lipocalin 2, and RNase 7, are highly expressed in psoriatic skin lesions. These peptides broadly regulate immunity by interacting with various immune cells and linking innate and adaptive immune responses during the progression of psoriasis. In this review, we summarize the recent findings regarding AMPs in the pathogenesis of psoriasis with a main focus on their immunomodulatory abilities.

Role of Cathelicidin (Ll-37) and Human Β-Defensin In Atopic Dermatitis And Psoriasis

The Human epithelium, including the epidermis produces antimicrobial peptide (AMP)as part of innate immunity. Cathelicidin and human β-defensins are the most AMPfound on the skin. This antimicrobial peptide has a role in the response of the naturalimmune system by becoming the front line of the defense system against infection. Thediscussion of this literature review will focus on cathelicidin and human β-defensin-1which are the main AMPs that affect atopic dermatitis and psoriasis. Antimicrobialpeptides are excessively produced in lesional psoriatic scales or rosacea in contrast tothe atopic skin that shows lower AMP levels when compared with psoriasis. Despitethe impaired skin barrier which facilitates potentially pathogenic microbes to colonizethe epidermis, patients with psoriasis surprisingly present a low frequency of skininfections, whereas patients with atopic dermatitis are predominantly susceptible toparticular cutaneous bacterial, fungal and viral infections. One possible explanation ofthe fact is the difference in the expression of AMPs. DA patients have fewer AMPexpression characteristics, especially cathelicidins LL-37 and HBD-2. Research onantimicrobial use can help reduce pathogen colonization so that clinical improvementof AD occurs. In the case of psoriasis, AMP expression increases, especially LL-37 andHBD-2, showing synergistic antimicrobial activity that is effective in eradicatingmicrobial colonization, so there is no strong evidence to support antibiotic use intreating psoriasis or in preventing disease.

The Immune Function of Keratinocytes in Anti-Pathogen Infection in the Skin

Abstract Keratinocytes, located in the outer part of human skin, are the main epidermal cell type and play an essential role in skins defense against infection. Besides creating a physical barrier between the environment and the internal body, keratinocytes exert powerful immune function in anti-pathogen infection in the skin. At the recognition stage, pattern recognition receptors (PRRs) expressed by keratinocytes sense pathogen-associated molecular patterns (PAMPs) existing in pathogens. Toll like receptors (TLRs) are the most important PRRs in keratinocytes. Other PRRs such as dectin-1 and nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) are also found to participate in this process. Activated PRRs enhance the secretion of cytokines, chemokines and the production of antimicrobial peptides (AMPs). Proinflammatory cytokines tumor necrosis factor-α, interleukin (IL)-1α, IL-6, IL-1β and IL-18, chemokines (C-X-Cmotif) ligand (CXCL) 1, CXCL2, CCL20, CCL2 and IL-8, AMPs human β-defensin (HBD) 2, HBD3 and LL37 are the main molecules expressed in this procedure. Thymic stromal lymphopoietin (TSLP), IL-36γ, IL-17 family member IL-17C and anti-inflammatory cytokine IL-10 can also be secreted. Some molecules produced by keratinocytes such as ribonuclease 5 and 7, S100 proteins own antimicrobial properties. Keratinocytes defense responses can be regulated by internal and external factors. This review summarizes recent advances on the innate immune function of keratinocytes against infection, promoting the finding of a new direction for avoiding severe skin infection as well as the potential treatment of keratinocyte-associated inflammatory dermatosis.

Human β-Defensin 118 Attenuates Escherichia coli K88-Induced Inflammation and Intestinal Injury in Mice.

Antibiotics are widely used to treat various inflammatory bowel diseases caused by enterotoxigenic Escherichia coli (ETEC). However, continuous use of antibiotics may lead to drug resistance. In this study, we investigated the role of human β-defensin 118 (DEFB118) in regulating the ETEC-induced inflammation and intestinal injury. ETEC-challenged or non-challenged mice were treated by different concentrations of DEFB118. We show that ETEC infection significantly increased fecal score (P < 0.05) and serum concentrations of interlukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Moreover, the concentrations of D-lactic acid, C-reactive protein (CRP), creatinine (CREA), and urea (P < 0.05) were both increased in the ETEC-challenged mice. However, DEFB118 significantly decreased their concentrations in the serum (P < 0.05). DEFB118 not only alleviated tissue damage in spleen upon ETEC challenge, but also increased the villus height in duodenum and ileum (P < 0.05). Moreover, DEFB118 improved the localization and abundance of tight junction protein ZO-1 in jejunal epithelium. Interestingly, DEFB118 decreased the expression levels of critical genes involving in mucosal inflammatory responses (NF-κB, TLR4, IL-1β, and TNF-α) and the apoptosis (caspase3) upon ETEC challenge (P < 0.05), whereas DEFB118 significantly upregulated the expression of mucosa functional genes such as the mucin1 (MUC1) and sodium-glucose transporter-1 (SGLT-1) in the ETEC-challenged mice (P < 0.05). These results indicated a novel function of the DEFB118. The anti-inflammatory effect of DEFB118 should make it an attractive candidate to prevent various bacteria-induced inflammatory bowel diseases.

Human β-defensin-2 suppresses key features of asthma in murine models of allergic airways disease.

Asthma is an airway inflammatory disease and a major health problem worldwide. Anti-inflammatory steroids and bronchodilators are the gold-standard therapy for asthma. However, they do not prevent the development of the disease, and critically, a subset of asthmatics are resistant to steroid therapy. To elucidate the therapeutic potential of human β-defensins (hBD), such as hBD2 mild to moderate and severe asthma. We investigated the role of hBD2 in a steroid-sensitive, house dust mite-induced allergic airways disease (AAD) model and a steroid-insensitive model combining ovalbumin-induced AAD with Cmuridarum (Cmu) respiratory infection. In both models, we demonstrated that therapeutic intranasal application of hBD2 significantly reduced the influx of inflammatory cells into the bronchoalveolar lavage fluid. Furthermore, key type 2 asthma-related cytokines IL-9 and IL-13, as well as additional immunomodulating cytokines, were significantly decreased after administration of hBD2 in the steroid-sensitive model. The suppression of inflammation was associated with improvements in airway physiology and treatment also suppressed airway hyper-responsiveness (AHR) in terms of airway resistance and compliance to methacholine challenge. These data indicate that hBD2 reduces the hallmark features and has potential as a new therapeutic agent in allergic and especially steroid-resistant asthma.

The truncated human beta-defensin 118 can modulate lipopolysaccharide mediated inflammatory response in RAW264.7 macrophages

The family of human β-defensins consists of small cysteine-rich peptides, which are receiving significant attention due to their antimicrobial activity. The N-terminal cysteine motif of β-defensin is considered to contribute to its biological activity. Human β-defensin 118 (DEFB 118) is a particular anion β-defensin expressed predominantly in the male reproductive tract, but its physiological activity has not yet been revealed. In order to verify the potential role of the N-terminal domain of DEFB118 peptide in the regulation of infection, the truncated β-defensin core region of DEFB118 peptide was expressed with IMPACT-pTWIN1 system in Escherichia coli. Herein, the purified homogeneous DEFB118 peptide was identified by mass spectrometry and circular dichroism spectroscopy. The in vitro experiments revealed that DEFB118 peptide exhibited prominent LPS-binding potency (KD: 2.94 nM). Moreover, the DEFB118 core peptide significantly inhibited the mRNA level of LPS-induced inflammatory cytokines including IL-α, IL-1β, IL-6 and TNF-α in RAW264.7 cells, and correspondingly decreased secretion of IL-6 and TNF-α. We concluded that strong binding of DEFB118 to LPS might prevent LPS from binding to its receptor, and hence inhibited cytokines secretion. The results of this study may be a benefit to elucidate the immune protection of DEFB118 in the male reproductive tract.

Expression and Functional Characterization of a Novel Antimicrobial Peptide: Human Beta-Defensin 118

Purpose β-Defensin 118 (DEFB118) is a novel host defense peptide (HDP) identified in humans. To evaluate its potentials for future utilization, the DEFB118 gene was expressed in Escherichia coli (E. coli) and the recombinant protein was fully characterized. Methods The DEFB118 protein was obtained by heterologous expression using E. coli Rosetta (DE3). Antibacterial activity of DEFB118 was determined by using various bacterial strains. IPEC-J cells challenged by E. coli K88 were used to determine its influences on inflammatory responses. Results The E. coli transformants yielded more than 250 μg/mL DEFB118 protein after 4 h induction by 1.0 mM IPTG. The DEFB118 was estimated by SDS-PAGE to be 30 kDa, and MALDI-TOF analysis verified that it is a human β-defensin 118. Importantly, the DEFB118 showed antimicrobial activities against both Gram-negative bacteria (E. coli K88 and E. coli DH5α) and Gram-positive bacteria (S. aureus and B. subtilis), with a minimum inhibitory concentration (MIC) of 4 μg/mL. Hemolytic assays showed that DEFB118 had no detrimental impact on cell viability. Additionally, DEFB118 was found to elevate the viability of IPEC-J2 cells upon E. coli K88 challenge. Moreover, DEFB118 significantly decreased cell apoptosis in the late apoptosis phase and downregulated the expression of inflammatory cytokines such as IL-1β and TNF-α in IPEC-J2 cell exposure to E. coli K88. Conclusions These results suggested a novel function of the mammalian defensins, and the antibacterial and anti-inflammatory properties of DEFB118 may allow it as a potential substitute for conventionally used antibiotics or drugs.

Conjugation of Human β-Defensin 2 to Spike Protein Receptor-Binding Domain Induces Antigen-Specific Protective Immunity against Middle East Respiratory Syndrome Coronavirus Infection in Human Dipeptidyl Peptidase 4 Transgenic Mice

Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe acute respiratory symptoms. Due to the lack of medical countermeasures, effective and safe vaccines against MERS-CoV infection are urgently required. Although different types of candidate vaccines have been developed, their immunogenicity is limited, and the dose and administration route need optimization to achieve optimal protection. We here investigated the potential use of human β-defensin 2 (HBD 2) as an adjuvant to enhance the protection provided by MERS-CoV vaccination. We found that immunization of human dipeptidyl peptidase 4 (hDPP4)-transgenic (hDPP4-Tg) mice with spike protein receptor-binding domain (S RBD) conjugated with HBD 2 (S RBD-HBD 2) induced potent antigen (Ag)-specific adaptive immune responses and protected against MERS-CoV infection. In addition, immunization with S RBD-HBD 2 alleviated progressive pulmonary fibrosis in the lungs of MERS-CoV-infected hDPP4-Tg mice and suppressed endoplasmic reticulum stress signaling activation upon viral infection. Compared to intramuscular administration, intranasal administration of S RBD-HBD 2 induced more potent mucosal IgA responses and was more effective for protecting against intranasal MERS-CoV infection. In conclusion, our findings suggest that HBD 2 potentiates Ag-specific immune responses against viral Ag and can be used as an adjuvant enhancing the immunogenicity of subunit vaccine candidates against MERS-CoV.

Increased serum antimicrobial peptide LL-37 and HBD-2 combined with 25-hydroxyvitamin D3 deficiency in infants with pertussis.

Most children with serious infection diseases suffer from malnutrition. Vitamin D participates in the immune response through endogenous antimicrobial peptides (AMPs) regulation. The aim of this study is to investigate the expression of 25-hydroxyvitamin D3 [25(OH)D3], AMPs [LL-37 and human β-defensin 2 (HBD-2)] in the children with pertussis. Serum levels of 25(OH)D3, LL-37, and HBD-2 were detected in 116 children with pertussis aged at 1-12 months (67 males and 49 females). Fifty healthy infants at similar age were employed as normal controls. The serum 25(OH)D3 levels in the children with mild (27.30 ± 5.98 ng/ml) and severe (24.40 ± 6.27 ng/ml) pertussis were significantly lower than that in the healthy group (30.16 ± 5.13 ng/ml; p <0.01). The vitamin D deficiency rates in children with mild (55.9%) and severe (78.12%) pertussis were significantly higher than that in the control group (34%; p < 0.01). The serum levels of LL-37 and HBD-2 were significantly higher in pertussis patients. Spearman rank correlation analysis did not show any correlation of 25-(OH)D3 with LL-37 or HBD-2. Most children with pertussis had vitamin D deficiency accompanied by elevated serum LL-37 and HBD-2 levels. However, the average level of 25(OH)D3 at 26.50 ng/ml in the infants with pertussis may not affect the immuno-regulatory ability; thus, the infants with pertussis still maintained a higher level of AMPs (LL-37 and HBD-2) against pertussis infection.

Role of Antimicrobial Peptides in Skin Barrier Repair in Individuals with Atopic Dermatitis.

Atopic dermatitis (AD) is a common chronic inflammatory skin disease that exhibits a complex interplay of skin barrier disruption and immune dysregulation. Patients with AD are susceptible to cutaneous infections that may progress to complications, including staphylococcal septicemia. Although most studies have focused on filaggrin mutations, the physical barrier and antimicrobial barrier also play critical roles in the pathogenesis of AD. Within the physical barrier, the stratum corneum and tight junctions play the most important roles. The tight junction barrier is involved in the pathogenesis of AD, as structural and functional defects in tight junctions not only disrupt the physical barrier but also contribute to immunological impairments. Furthermore, antimicrobial peptides, such as LL-37, human β-defensins, and S100A7, improve tight junction barrier function. Recent studies elucidating the pathogenesis of AD have led to the development of barrier repair therapy for skin barrier defects in patients with this disease. This review analyzes the association between skin barrier disruption in patients with AD and antimicrobial peptides to determine the effect of these peptides on skin barrier repair and to consider employing antimicrobial peptides in barrier repair strategies as an additional approach for AD management.

Effect of the Cellular Extract of Co-cultured Lactobacillus Casei on BAX and Human β-Defensin 2 Genes Expression in HT29 Cells

Aims: Defensins are cysteine-rich antimicrobial cationic peptides and BAX is a proapoptotic gene that can cause cell death. This study aimed to investigate the effect of cellular extract of co-cultured Lactobacillus casei on the expression of BAX and human β-defensin 2 (hBD-2) genes in HT29 cells. Methods &amp; Materials: This experimental study was conducted in the Research Center for Pharmaceutical Nanotechnology of Tabriz University of Medical Sciences in 2017. The HT29 cell line was obtained from the Pasteur Institute of Iran, and cells were assessed using Microculture Tetrazolium Test (MTT) after culturing. DNA was extracted from the treated cells, and then the DNA ladder assay was carried out. After preparing cDNA, the expression levels of BAX and hBD-2 genes in the HT29 cell line were measured using a real-time Polymerase Chain Reaction (PCR) method. Findings: The results of the MTT assay indicated that Lactobacillus casei inhibited the proliferation of HT29 cells and induced apoptosis in these cells. Results of DAPI staining and DNA ladder assay obtained from treating HT29 cells by Lactobacillus casei showed qualitative changes in cell apoptosis. Moreover, realtime PCR results indicated that Lactobacillus casei bacteria significantly increased the expression of the hBD-2 gene in HT29 colon cancer cells within 12-24 hours (P= 0.023), while BAX gene expression showed no significant change in the first 24 hours (P= 0.37). Conclusion: The extract of Lactobacillus casei can be used to stimulate cancer cells to produce β-defensins, inhibit pathogens, prevent the stimulation of cellular signaling, and fight antibiotic-resistant bacteria.

Altered serum profile of the interleukin-22 system in inflammatory bowel disease

Background and AimInterleukin-22 (IL-22), plays a vital role in the mucosal repair of inflammatory bowel disease (IBD). Serum levels of IL-22 and IL-22 binding protein (IL-22BP), a soluble inhibitory IL-22 receptor, were measured in patients with IBD to investigate the profile of IL-22 in the systemic circulation. MethodsBlood samples from 92 healthy subjects, 98 patients with ulcerative colitis (UC), and 105 patients with Crohn's disease (CD) were analyzed for serum levels of IL-22, IL-22BP, human β-defensin 2 (hBD-2), and serum inflammatory parameters. Disease activity was assessed by the partial Mayo score and Harvey-Bradshaw index for UC and CD, respectively. ResultsSerum IL-22 level was lower in UC (P < 0.001) and CD (P < 0.001) vs control and its decrease was more pronounced in CD than in UC (P = 0.019). Serum IL-22BP level was lower in UC (P < 0.001) and CD (P < 0.001) vs control and correlated with inflammatory parameters (albumin and C-reactive protein (CRP) in UC; hemoglobin, albumin, and CRP in CD). Serum IL-22/IL-22BP ratios were higher in UC (P = 0.009) vs control and correlated with inflammatory parameters (albumin and CRP). Serum hBD-2 level was higher only in CD (P = 0.015) but did not correlate with serum IL-22 levels, IL-22BP levels, IL-22/IL-22BP ratios, or inflammatory parameters. ConclusionsDysregulation of the IL-22 system in the blood may play a role in the pathogenesis of IBD. Further studies are needed to understand the pathogenic and clinical significance of the blood IL-22 system in IBD.

Potential Application of Human β-Defensin 4 in Dental Pulp Repair.

When pulp tissue is damaged by caries or trauma, vital pulp therapy (VPT) can help preserve the pulp tissue for long-term retention of teeth. However, the choice of pulp capping agent used in VPT is important for the successful preservation of the pulp tissue. Here we investigated the expression and biological function of human β-defensin 4 (HBD4) in dental pulp stem cells (DPSC) and explored its potential as a pulp capping agent. We examined the expression of HBD4 in DPSC in vitro using qPCR and immunofluorescence staining. We also looked at the effect of HBD4 on inflammatory factors in lipopolysaccharide (LPS)-stimulated DPSC, and its effects on mineralizing cell phenotype differentiation, via qPCR and western blot. Finally, we examined the ability of HBD4 to promote the restoration of the pulp-dentin complex in vivo, using male Wistar rats with reversible pulpitis. We found HBD4 was highly expressed in DPSC stimulated by TNF-α and IL-1α. HBD4 down-regulated the expression of inflammatory mediators (i.e., IL-1α, IL-1β, IL-6, TNF-α) in LPS-stimulated DPSC, and suppressed MAPK activity and the NF-κB pathway. HBD4 also enhanced the differentiation of DPSC into osteoblasts or odontoblasts, potentially by modulating the Notch pathway. Furthermore, HBD4 controlled the degree of pulp inflammation in a rat model of reversible pulpitis and induced the formation of restorative dentin. Together our findings indicate HBD4 may be a useful pulp capping agent for use in VPT.