Expression Of LL-37 Research Articles

LL37-DNA Complex Drives Vitiligo Progression Through TLR9-MyD88 Signaling Pathways.

Vitiligo is an autoimmune disorder characterized by chronic depigmentation and milk-white patches on the skin. Skin infiltration by autoreactive CD8+ T cells causes melanocyte destruction in vitiligo. Multiple risk factors, particularly immune-related inflammatory factors, are involved in the disappearance of melanocytes. LL37 is a classic damage-associated molecular pattern molecule that is involved in the development of various autoimmune diseases. An enhanced expression of LL37 in vitiligo is known; however, the exact role of LL37 in melanocyte loss has not yet been elucidated. In the present study, we detected increased LL37 expression in vitiligo serum and lesions. Furthermore, we confirmed that cultured keratinocytes released LL37 after treatment with H2O2. Moreover, the LL37-DNA complex enhanced the secretion of CXCL9, CXCL10, and CXCL16 from keratinocytes via the TLR9-MyD88 signaling pathway and facilitated the migration of CD8+ T cells. Altogether, our study demonstrates that LL37 released from keratinocytes binds to DNA and contributes to melanocyte destruction under oxidative stress-induced autoimmunity in vitiligo.

Functions of Hemp-Induced Exosomes against Periodontal Deterioration Caused by Fine Dust.

Although fine dust is linked to numerous health issues, including cardiovascular, neurological, respiratory, and cancerous diseases, research on its effects on oral health remains limited. In this study, we investigated the protective effects of mature hemp stem extract-induced exosomes (MSEIEs) on periodontal cells exposed to fine dust. Using various methods, including microRNA profiling, PCR, flow cytometry, immunocytochemistry, ELISA, and Alizarin O staining, we found that MSE treatment upregulated key microRNAs, such as hsa-miR-122-5p, hsa-miR-1301-3p, and hsa-let-7e-5p, associated with vital biological functions. MSEIEs exhibited three primary protective functions: suppressing inflammatory genes while activating anti-inflammatory ones, promoting the differentiation of periodontal ligament stem cells (PDLSCs) into osteoblasts and other cells, and regulating LL-37 and MCP-1 expression. These findings suggest that MSEIEs have potential as functional biomaterials for applications in pharmaceuticals, cosmetics, and food industries.

Signaling pathways and targeted therapy for rosacea.

Rosacea is a chronic skin inflammatory disease with a global prevalence ranging from 1% to 20%. It is characterized by facial erythema, telangiectasia, papules, pustules, and ocular manifestations. Its pathogenesis involves a complex interplay of genetic, environmental, immune, microbial, and neurovascular factors. Recent studies have advanced our understanding of its molecular basis, focusing on toll-like receptor (TLR) 2 pathways, LL37 expression, mammalian target of rapamycin (mTOR) activation, interleukin (IL)-17 signaling, transient receptor potential vanilloid (TRPV) functions, and the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathways. LL37-associated signaling pathways, particularly involving TLR2 and mTORC1, are critical in the pathogenesis of rosacea. LL37 interacts with signaling molecules such as extracellular signal-regulated kinases 1 and 2 (ERK1/2), nuclear factor kappa B (NF-κB), inflammasomes, C-X-C motif chemokine ligand 8 (CXCL8), mas-related G-protein-coupled receptor X2 (MRGPRX2)-TRPV4, and vascular endothelial growth factor (VEGF). This interaction activates macrophages, neutrophils, mast cells, and vascular endothelial cells, leading to cytokine release including tumor necrosis factor-alpha (TNF-α), IL-6, IL-1β, C motif chemokine ligand (CCL) 5, CXCL9, and CXCL10. These processes contribute to immune response modulation, inflammation, and angiogenesis in rosacea pathophysiology. The IL-17 signaling pathway also plays a crucial role in rosacea, affecting angiogenesis and the production of inflammatory cytokines. In addition, recent insights into the JAK/STAT pathways have revealed their integral role in inflammatory and angiogenic mechanisms associated with rosacea. Rosacea treatment currently focuses on symptom management, with emerging insights into these molecular pathways providing more targeted and effective therapies. Biological agents targeting specific cytokines, IL-17 inhibitors, JAK inhibitors, and VEGF antagonists are promising for future rosacea therapy, aiming for enhanced efficacy and fewer side effects. This review provides a comprehensive overview of the current knowledge regarding signaling pathways in rosacea and potential targeted therapeutic strategies.

Nisin-preconditioned mesenchymal stem cells combatting nosocomial Pseudomonas infections

BackgroundNosocomial infections caused by multidrug-resistant Pseudomonas aeruginosa are a considerable public health threat, requiring innovative therapeutic approaches. ObjectivesThis study explored preconditioning mesenchymal stem cells (MSCs) with the antimicrobial peptide Nisin to enhance their antibacterial properties while maintaining regenerative capacity. MethodsHuman MSCs were preconditioned with varying concentrations of Nisin (0.1–1000 IU/mL) to determine an optimal dose. MSCs preconditioned with Nisin were characterized using microscopy, flow cytometry, gene expression analysis, and functional assays. The effects of preconditioning on the viability, phenotype, differentiation capacity, antimicrobial peptide expression, and antibacterial activity of MSCs against Pseudomonas aeruginosa were tested in vitro. The therapeutic efficacy was evaluated by topically applying conditioned media from Nisin-preconditioned versus control MSCs to infected wounds in a rat model, assessing bacterial burden, healing, host response, and survival. ResultsAn optimal Nisin dose of 500 IU/mL was identified, which increased MSC antibacterial gene expression and secretome activity without compromising viability or stemness. Nisin-preconditioned MSCs showed upregulated expression of LL37 and hepcidin. Conditioned media from Nisin-preconditioned MSCs exhibited about 4-fold more inhibition of P. aeruginosa growth compared to non-preconditioned MSCs. In the wound infection model, the secretome of Nisin-preconditioned MSCs suppressed bacterial load, accelerated wound closure, modulated inflammation, and improved survival compared to standard MSC treatments. ConclusionThis study explores the effect of preconditioning MSCs with the antimicrobial peptide Nisin on enhancing their antibacterial properties while maintaining regenerative capacity. Secreted factors from Nisin-preconditioned MSCs have the potential to attenuate infections and promote healing in vivo. The approach holds translational promise for managing antibiotic-resistant infections and warrants further development. Preconditioned MSCs with Nisin may offer innovative, multifaceted therapies for combating nosocomial pathogens and promoting tissue regeneration.

Enhancement of innate immunity in gingival epithelial cells by vitamin D and HDAC inhibitors.

The human host defense peptide LL-37 is a component of the innate immune defense mechanisms of the oral cavity against colonization by microbes associated with periodontal disease. We have previously shown that the active form of vitamin D, 1,25(OH)2D3, can induce the expression of LL-37 in gingival epithelial cells (GEC), and prevent the invasion and growth of periopathogenic bacteria in these cells. Further, experimental vitamin D deficiency resulted in increased gingival inflammation and alveolar bone loss. Epidemiological studies have shown associations between vitamin D deficiency and periodontal disease in humans, suggesting application of vitamin D could be a useful therapeutic approach. Further, since we have shown the local activation of vitamin D by enzymes expressed in the GEC, we hypothesized that we could observe this enhancement with the stable, and inexpensive inactive form of vitamin D, which could be further increased with epigenetic regulators. We treated 3-dimensional primary cultures of GEC topically with the inactive form of vitamin D, in the presence and absence of selected histone deacetylase (HDAC) inhibitors. LL-37 mRNA levels were quantified by quantitative RT-PCR, and inhibition of invasion of bacteria was measured by fluorescence microscopy. Vitamin D treatment led to an induction of LL-37 mRNA levels, as well as an inhibition of pro-inflammatory cytokine secretion. This effect was further enhanced by HDAC inhibitors, most strongly when the HDAC inhibitor, phenyl butyrate (PBA) was combined with Vitamin D3. This was observed both in solution and in a prototype gel formulation using sodium butyrate. Finally, this combination treatment led to an increase in the antimicrobial activity against infection by Porphyromonas gingivalis and Filifactor alocis, bacteria associated with periodontal lesions, as well as herpes simplex virus, which has also been shown to be associated with periodontal lesions. Our results demonstrate that a combination of inactive vitamin D and sodium butyrate could be developed as a safe treatment for periodontal disease.

Probiotics suppress LL37 generated rosacea-like skin inflammation by modulating the TLR2/MyD88/NF-κB signaling pathway.

Rosacea, a chronic inflammatory dermatological condition, is characterized by facial erythema and pustules. Recent investigations have delved into the interplay between the gut microbiota and rosacea pathogenesis, unveiling promising avenues for therapeutic intervention. In this study, we screened and isolated strains Ligilactobacillus salivarius 23-006 and Lacticaseibacillus paracasei 23-008 from the feces of healthy volunteers and evaluated the intervention effects of probiotics on rosacea by constructing an LL37 induced rosacea-like mouse model. Our results showed that both L. salivarius 23-006 and L. paracasei 23-008 were probiotic strains with favourable properties. In specific, we observed that both L. salivarius 23-006 and L. paracasei 23-008 alleviated skin lesions, reduced skin inflammatory infiltrates, and decreased the expression of inflammatory factors in mice, with the combination of L. salivarius 23-006 and L. paracasei 23-008 having the most significant effect. Moreover, the combination of strains reduced the expression of cathelicidin LL37 and rosacea-associated factors by inhibiting the TLR2/MyD88/NF-κB pathway. The 16S rRNA analysis showed that the combination enhanced the intestinal barrier, restored intestinal microbiota homeostasis, and up-regulated the abundance of Lactobacillus while down-regulating the abundance of Coprococcus and Oscillospira. We also explored the effects of postbiotics of L. salivarius 23-006 and L. paracasei 23-008 on rosacea. While postbiotics could also ameliorate the rosacea-like phenotype in mice via the TLR2/MyD88/NF-κB pathway, the effects were not as pronounced as those observed with probiotic treatment. However, the postbiotics still enhanced the intestinal barrier, up-regulated the Lactobacillus abundance, and modulated the intestinal microbiota. In conclusion, our study revealed that L. salivarius 23-006 and L. paracasei 23-008 improved rosacea by regulating the TLR2/MyD88/NF-κB pathway and intestinal microbiota, providing a theoretical basis for the treatment of rosacea.

Association between dysbiotic perio-pathogens and inflammatory initiators and mediators in COVID-19 patients with diabetes

It has been suggested that a corona virus infection is linked to chronic periodontitis (COVID-19). Our objectives were to look at the expression of angiotensin-converting enzyme-2 (ACE2) in periodontal compartments containing periodontal infections to determine if ACE2 is directly or indirectly responsible for the inflammation in periodontal tissues getting worse. In this study, six non-COVID-19 periodontitis patients without diabetes served as controls, and 23 hospitalized periodontitis patients were admitted with PCR-confirmed COVID-19 with diabetes mellitus (Group 1/G1, n = 10), and without diabetes (Group 2/G2, n = 13). We evaluated the mRNA expression of ACE2, IL-6, IL-8, complement C3, and LL-37, as well as the relative proportion of Porphyromonas gingivalis, Fusobacterium nucleatum, and Veillonella parvula to represent the dysbiosis condition in periodontal microenvironment using subgingival plaque and gingival crevicular fluids (GCF) samples and quantitative real time PCR (qPCR). Every analysis was done to ascertain how they related to one another. The area under the curve (AUC) and receiver operating characteristic (ROC) curve were used to determine the sensitivity and specificity of inflammatory indicators. All the grouped patients had ACE2 detected, according to our findings, but only the G1 patients had a positive correlation (p < 0.05) between ACE2 expression and the inflammatory markers. The combination of IL-6 and C3 mRNAs was found to be 0.78 and 0.55 for the G1 group and the G2 group, respectively, based on the ROC and AUC values. According to our research, the relationship between complement C3 and IL-6 may be able to predict the degree of periodontal inflammation in COVID-19 patients who also have diabetes.

Differential expression of antimicrobial peptides in human fungal keratitis.

To analyze a series of antimicrobial peptides (AMPs) in corneal tissue from individuals with fungal keratitis (FK) during the active phase of the fungus infection and after healing. Patients undergone lamellar keratoplasty for the treatment of severe FK or corneal scar had their corneal buttons sampled. Quantitative real-time polymerase chain reaction (PCR) was used to ascertain the gene expression of human beta-defensin (HBD)-1, -2, -3, -9, S100A7, 8, 9, and LL-37. All AMPs' messenger ribonucleic acid (mRNA) expression was considerably elevated in all samples (n=12). In contrast to controls, where HBD-2, -3, and S100A7 mRNAs were expressed at very low levels, it was discovered that HBD-1, -9, S100A8, S100A9, and LL-37 were constitutively expressed in all healed samples (n=4). HBD-1, -2 -3, S100A7, and LL-37 mRNAs were significantly increased in all active FK samples (n=8). The levels of HBD-9, S100A8, and S100A9 mRNAs were moderately upregulated in all active FK samples. Subgroup comparison showed that HBD-2 was significantly increased in Fusarium keratitis samples (n=5), and LL-37 mRNAs were significantly enhanced in Aspergillus keratitis samples (n=3). Whereas there was not significantly increased of HBD-1, -3, -9, S100A7, 8, 9 mRNA in Aspergillus keratitis samples compared with Fusarium keratitis samples. AMPs expression is increased in active FK, but not all AMPs are equally expressed. HBD-2 and LL-37 expression levels are the highest, showing some specificity of AMP expression related to FK. Human AMPs, particularly HBD-2 may play a significant role in Fusarium keratitis and LL-37 might be the key player in Aspergillus keratitis.

Cathelicidin LL-37 Expression in Human Breast Implant Capsules.

Capsular contracture is the most common complication following breast implant placement. Cathelicidin LL-37 is a cationic peptide involved in innate immunity. Initially investigated for its antimicrobial role, it was found to have pleiotropic activities, such as immunomodulation, angiogenesis stimulation, and tissue healing. The aim of the study was to investigate the expression and localization of LL-37 in human breast implant capsules and its relationship with capsular formation, remodeling, and clinical outcomes. The study enrolled 28 women (29 implants) who underwent expander substitution with definitive implant. Contracture severity was evaluated. Specimens were stained with hematoxylin and eosin, Masson trichrome, immunohistochemistry, and immunofluorescence for LL-37, CD68, α-smooth muscle actin, collagen type I and type III, CD31, and Toll-like receptor-4. LL-37 was expressed in macrophages and myofibroblasts of capsular tissue in 10 (34%) and nine (31%) of the specimens, respectively. In eight cases (27.5%), it was expressed by both macrophages and myofibroblasts of the same specimen. In infected capsules, expression by both cell types was found in all (100%) specimens. LL-37 expression by myofibroblasts positively correlated with its expression by macrophages ( P < 0.001). Moreover, LL-37 expression by macrophages of periexpander capsules negatively correlated with the severity of capsular contracture on definitive implants ( P = 0.04). This study demonstrates the expression of LL-37 in macrophages and myofibroblasts of capsular tissue and its negative correlation with the severity of capsular contracture following permanent implant placement. Expression or up-regulation of LL-37 may be involved in myofibroblast and macrophage modulation, thus playing a role in the pathogenic fibrotic process underlying capsular contracture. This is the first study to demonstrate LL37 expression in capsular tissue and to hypothesize its role in contracture and as a prognostic marker for contracture severity. If confirmed, medical strategies or implant coating could be implemented to reduce the risk of contracture for high-risk patients.

LL-37 Might Promote Local Invasion of Melanoma by Activating Melanoma Cells and Tumor-Associated Macrophages

LL-37 can stimulate various skin-resident cells to contribute to tumor development. Since tumor (T) stage is determined by the vertical invasion of tumor cells in melanoma, we hypothesized that the LL-37 expression level is correlated with the T stage in melanoma patients. Immunohistochemical staining of LL-37 was performed in each stage of melanoma (Tis-T4), suggesting the ratio of LL-37-expressing cells correlate positively to T stage severity. Next, to examine pro-angiogenetic factors induced by LL-37 stimulation, the B16F10 melanoma model was used. Intra-tumorally administered CRAMP, the mouse ortologe of LL-37, significantly increased the mRNA expression of CXCL5, IL23A, MMP1a, and MMP9 in B16F10 melanoma. To confirm the induction of pro-angiogenic factors, A375 human melanoma cells were stimulated by LL-37 in vitro. The mRNA expression of CXCL5, IL23A, and MMP9, but not MMP1, were significantly increased by LL-37 stimulation. Moreover, LL-37-stimulated A375 culture supernatant promoted tube networks, suggesting that these tumor-derived factors promote the pro-angiogenic effect on tumor development. In contrast to melanoma cell lines, M2 macrophages stimulated by LL-37 in vitro significantly increased their expression and secretion of MMP-1, but not MMP-9 expression. Collectively, these results suggest that LL-37 stimulates both tumor cells and macrophages to promote melanoma invasion by the induction of pro-angiogenic factors.

Anti-Inflammatory Activity of Panax notoginseng Flower Saponins Quantified Using LC/MS/MS

Panax notoginseng (Burk) F. H. Chen is a traditional Chinese medicinal and edible plant. However, Panax notoginseng flower (PNF) is rarely used. Therefore, the purpose of this study was to explore the main saponins and the anti-inflammatory bioactivity of PNF saponins (PNFS). We explored the regulation of cyclooxygenase 2 (COX-2), a key mediator of inflammatory pathways, in human keratinocyte cells treated with PNFS. A cell model of UVB-irradiation-induced inflammation was established to determine the influence of PNFS on inflammatory factors and their relationship with LL-37 expression. An enzyme-linked immunosorbent assay and Western blotting analysis were used to detect the production of inflammatory factors and LL37. Finally, liquid chromatography-tandem mass spectrometry was employed to quantify the main active components (ginsenosides Rb1, Rb2, Rb3, Rc, Rd, Re, Rg1, and notoginsenoside R1) in PNF. The results show that PNFS substantially inhibited COX-2 activity and downregulated the production of inflammatory factors, indicating that they can be used to reduce skin inflammation. PNFS also increased the expression of LL-37. The contents of ginsenosides Rb1, Rb2, Rb3, Rc, and Rd in PNF were much higher than those of Rg1, and notoginsenoside R1. This paper provides data in support of the application of PNF in cosmetics.

Induction of Endogenous Antimicrobial Peptides to Prevent or Treat Oral Infection and Inflammation

Antibiotics are often used to treat oral infections. Unfortunately, excessive antibiotic use can adversely alter oral microbiomes and promote the development of antibiotic-resistant microorganisms, which can be difficult to treat. An alternate approach could be to induce the local transcription and expression of endogenous oral antimicrobial peptides (AMPs). To assess the feasibility and benefits of this approach, we conducted literature searches to identify (i) the AMPs expressed in the oral cavity; (ii) the methods used to induce endogenous AMP expression; and (iii) the roles that expressed AMPs may have in regulating oral inflammation, immunity, healing, and pain. Search results identified human neutrophil peptides (HNP), human beta defensins (HBD), and cathelicidin AMP (CAMP) gene product LL-37 as prominent AMPs expressed by oral cells and tissues. HNP, HBD, and LL-37 expression can be induced by micronutrients (trace elements, elements, and vitamins), nutrients, macronutrients (mono-, di-, and polysaccharides, amino acids, pyropeptides, proteins, and fatty acids), proinflammatory agonists, thyroid hormones, and exposure to ultraviolet (UV) irradiation, red light, or near infrared radiation (NIR). Localized AMP expression can help reduce infection, inflammation, and pain and help oral tissues heal. The use of a specific inducer depends upon the overall objective. Inducing the expression of AMPs through beneficial foods would be suitable for long-term health protection. Additionally, the specialized metabolites or concentrated extracts that are utilized as dosage forms would maintain the oral and intestinal microbiome composition and control oral and intestinal infections. Inducing AMP expression using irradiation methodologies would be applicable to a specific oral treatment area in addition to controlling local infections while regulating inflammatory and healing processes.

Application of Topical Sandalore® Increases Epidermal Dermcidin Synthesis in Organ-Cultured Human Skin ex vivo

Introduction: Several olfactory receptors (ORs) are expressed in human skin, where they regulate skin pigmentation, barrier function, wound healing, and hair growth. Previously, we found that the selective activation of OR family 2 subfamily AT member 4 (OR2AT4) by the synthetic, sandalwood-like odorant Sandalore® differentially stimulates the expression of antimicrobial peptides (AMPs) in human scalp hair follicle epithelium ex vivo. As OR2AT4 is also expressed by epidermal keratinocytes, we hypothesized that it may modulate intraepidermal AMP synthesis, thereby contributing to skin microbiome management. Methods: We investigated this hypothesis in organ-cultured human skin in the presence of Sandalore® and antibiotics and evaluated epidermal production of two AMPs, LL37 (cathelicidin) and dermcidin (DCD), as well as OR2AT4, by quantitative immunohistomorphometry. Moreover, we quantified DCD secretion into the culture medium by ELISA and studied the effect of culture medium on selected bacterial and fungal strains. Results: Topical application of Sandalore®to organ-cultured human skin increased OR2AT4 protein expression, the number of DCD-positive intraepidermal cells, and DCD secretion into culture media, without significantly affecting epidermal LL37 expression. In line with the significantly increased secretion of DCD into the culture medium, we demonstrated, in a spectrophotometric assay, that application of conditioned media from Sandalore®-treated skin promotes Staphylococcus epidermidis, Malassezia restricta, and, minimally, Cutibacterium acnes and inhibits Staphylococcus aureus growth. Conclusion: In addition to demonstrating for the first time that DCD can be expressed by epidermal keratinocytes, our pilot study suggests that topical treatment of human skin with a cosmetic odorant (Sandalore®) has the potential to alter the composition of the human skin microbiome through the selective upregulation of DCD. If confirmed, Sandalore® could become an attractive adjuvant, nondrug treatment for dermatoses characterized by dysbiosis due to overgrowth of S. aureus and Malassezia, such as atopic dermatitis and seborrheic dermatitis.

Cathelicidin LL-37 promotes EMT, migration and metastasis of hepatocellular carcinoma cells in vitro and mouse model

ABSTRACT The effect of cathelicidin hCAP18/LL-37 in hepatocellular carcinoma (HCC) metastasis remains unclear. Here, we confirmed that LL-37 expression enhanced endothelial-mesenchymal transition (EMT), migration and invasion in HCC cells. And the HER2/EGFR-MAPK/ERK signal participated in the process above. More frequent lung metastases were observed in an LL-37-overexpressing hematogenous metastasis model. Interestingly, 1,25(OH)2D3 together with si-LL-37 significantly enhanced 1,25(OH)2D3-induced inhibition of migration and invasion in PLC/PRF-5 cells, and also enhanced reversion of the EMT process. Therefore, LL-37 is involved in HCC metastases, and may act as an important factor to attenuate the inhibitory activity of 1,25(OH)2D3 on HCC metastasis. Targeting hCAP18/LL-37 may offer a potential strategy to improve the anticancer activity of 1,25(OH)2D3 in HCC therapy.

Histone deacetylase (HDAC) inhibitors- based drugs are effective to control Mycobacterium tuberculosis infection and promote the sensibility for rifampicin in MDR strain.

Tuberculosis (TB) is a major public health problem, which has been aggravated by the alarming growth of drug-resistant tuberculosis. Therefore, the development of a safer and more effective treatment is needed. The aim of this work was repositioning and evaluate histone deacetylases (HDAC) inhibitors- based drugs with potential antimycobacterial activity. Using an in silico pharmacological repositioning strategy, three molecules that bind to the catalytic site of histone deacetylase were selected. Pneumocytes type II and macrophages were infected with Mycobacterium tuberculosis and treated with pre-selected HDAC inhibitors (HDACi). Subsequently, the ability of each of these molecules to directly promote the elimination of M. tuberculosis was evaluated by colony-forming unit (CFU)/mL. We assessed the expression of antimicrobial peptides and respiratory burst using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Aminoacetanilide (ACE), N-Boc-1,2-phenylenediamine (N-BOC), 1,3-Diphenylurea (DFU), reduce bacillary loads in macrophages and increase the production of β-defensin-2, LL-37, superoxide dismutase (SOD) 3 and inducible nitric oxide synthase (iNOS). While only the use of ACE in type II pneumocytes decreases the bacterial load through increasing LL-37 expression. Furthermore, the use of ACE and rifampicin inhibited the survival of intracellular multi-drug resistance M. tuberculosis. Our data support the usefulness of in silico approaches for drug repositioning to provide a potential adjunctive therapy for TB.

Cathelicidin Antimicrobial Peptide LL37 Induces Toll-Like Receptor 8 and Amplifies IL-36γ and IL-17C in Human Keratinocytes

LL37 is produced by skin injury and bacterial infection and plays an important role in the early stages of psoriasis. In particular, the intracellular receptors toll-like receptors (TLR)3, TLR7, TLR8, and TLR9 are thought to be involved in the pathogenesis of psoriasis in conjunction with LL37, but the interaction between TLR7/8 and LL37 in keratinocytes (KCs) remains unclear. This study aimed to clarify the relationship between LL37 and TLR7/8 in KCs and their involvement in the pathogenetic pathways seen in psoriasis using cultured KCs and skin samples of patients with psoriasis. TLR7/8 was induced by LL37 in KCs. TLR8 but not TLR7 functionally induced many psoriasis-related molecules, whereas IL-17C was not altered by the blockade of TLR7/8. Although costimulation of LL37 with self-RNA/DNA did not show any interaction, LL37 itself would promote psoriasis-related genes. IL-36 receptor antagonistic antibody suppressed IL-17C induced by LL37. In psoriatic epidermis, LL37, TLRs, IL-17C, and IL-36γ expressions were increased and coexpressed with each other. Thus, we concluded that LL37 activates TLR8 in KCs and induces IL-17C through the induction of IL-36γ. Regulation of TLR8 or LL37 in KCs could be a potential therapeutic strategy for psoriatic inflammation.

In silico assessment of missense point mutations on human cathelicidin LL-37

Cathelicidin antimicrobial peptides are a diverse family of cationic amphipathic peptides with multiple activities. In humans, cathelicidin LL-37 is one of the main host defense peptides with a remarkable medical and biotechnological potential. Deregulation of LL-37 expression has been associated with inflammatory diseases. However the effects of point mutations driven by single nucleotide polymorphisms (SNPs) on LL-37 are unknown. Here we applied an array of computational tools to investigate the effects of such mutations on LL-37 structure and activity. Due to the fact that, on cathelicidins, the prodomain is more conserved than the mature peptide, the SNP effect predictions were biased and, overall, resulted in neutral effects; and due to the slight changes in physicochemical properties, the antimicrobial predictions indicated the maintenance of such activity. Nonetheless, R07P, R07W, R29Q, R29W mutations reduced the peptide net charge, which in turn could result in less active LL-37 variants. Molecular dynamics data indicated that R07Q and N30Y mutations altered the LL-37 structure, leading to potential deleterious effects. In addition, the helix dipole is altered in G03A, R07P, R07W and L31P mutations, which could also alter the antimicrobial activity. Our results indicated that despite the mutations did not alter the residues from LL-37 active core, they could influence the antimicrobial activity and consequently, could be involved in inflammatory diseases.

In vitro Screening of Herbal Medicinal Products for Their Supportive Curing Potential in the Context of SARS-CoV-2.

COVID-19 herbal medicinal products may have the potential for symptom relief in nonsevere or moderate disease cases. In this in vitro study we screened the five herbal medicinal products Sinupret extract (SINx), Bronchipret thyme-ivy (BRO-TE), Bronchipret thyme-primula (BRO TP), Imupret (IMU), and Tonsipret (TOP) with regard to their potential to (i) interfere with the binding of the human angiotensin-converting enzyme 2 (ACE2) receptor with the SARS-CoV-2 spike S1 protein, (ii) modulate the release of the human defensin HBD1 and cathelicidin LL-37 from human A549 lung cells upon spike S1 protein stimulation, and (iii) modulate the release of IFN-γ from activated human peripheral blood mononuclear cells (PBMC). The effect of the extracts on the interaction of spike S1 protein and the human ACE2 receptor was measured by ELISA. The effects on the intracellular IFN-γ expression in stimulated human PBMC were measured by flow cytometry. Regulation of HBD1 and LL-37 expression and secretion was assessed in 25 d long-term cultured human lung A549 epithelial cells by RT-PCR and ELISA. IMU and BRO-TE concentration-dependently inhibited the interaction between spike S1 protein and the ACE2 receptor. SINx, TOP, and BRO-TE significantly upregulated the intracellular expression of anti-viral IFN-γ from stimulated PBMC. Cotreatment of A549 cells with IMU or BRO TP together with SARS-CoV-2 spike protein significantly upregulated mRNA expression (IMU) and release of HBD1 (IMU and BRO TP) and LL-37 (BRO TP). The in vitro screening results provide first evidence for an immune-activating potential of some of the tested herbal medicinal extracts in the context of SARS-CoV-2. Whether these could be supportive in symptom relief or curing from SARS-CoV-2 infection needs deeper understanding of the observations.

Sphingosine-1-Phosphate-Triggered Expression of Cathelicidin LL-37 Promotes the Growth of Human Bladder Cancer Cells.

It has been proven that tumour growth and progression are regulated by a variety of mediators released during the inflammatory process preceding the tumour appearance, but the role of inflammation in the development of bladder cancer is ambiguous. This study was designed around the hypothesis that sphingosine-1-phosphate (S1P), as a regulator of several cellular processes important in both inflammation and cancer development, may exert some of the pro-tumorigenic effects indirectly due to its ability to regulate the expression of human cathelicidin (hCAP-18). LL-37 peptide released from hCAP-18 is involved in the development of various types of cancer in humans, especially those associated with infections. Using immunohistological staining, we showed high expression of hCAP-18/LL-37 and sphingosine kinase 1 (the enzyme that forms S1P from sphingosine) in human bladder cancer cells. In a cell culture model, S1P was able to stimulate the expression and release of hCAP-18/LL-37 from human bladder cells, and the addition of LL-37 peptide dose-dependently increased their proliferation. Additionally, the effect of S1P on LL-37 release was inhibited in the presence of FTY720P, a synthetic immunosuppressant that blocks S1P receptors. Together, this study presents the possibility of paracrine relation in which LL-37 production following cell stimulation by S1P promotes the development and growth of bladder cancer.

Expression of anti-inflammatory markers IL-2, IL-10, TGF-β1, βDEF-2, βDEF-3 and Cathelicidin LL37 in dairy cattle milk with different health status of the udder.

Great economic losses to the dairy industry are associated with bovine mastitis, which results in poor milk quality and high treatment costs. Anti-inflammatory proteins play an important role in the suppression of the immune response against invading pathogenic microorganisms and are therefore being studied for possible use in the early diagnosis of mastitis. In our study, we used milk samples from 15 cows of Holstein Friesian breed with different health status (5 healthy, 5 subclinical, and 5 clinical animals), and tested them using immunohistochemical (IHC) analysis to evaluate the presence of IL-2, IL-10, TGF-β1, βDEF-2, DEF-3, and Cathelicidin LL37 proteins. The calculation of positively and negatively stained cells for each biomarker was performed using the semiquantitative counting method. We found the presence of all factors with the exception of Cathelicidin LL37, which was almost absent in milk samples of all animal groups. The significant decrease of IL-10, β-def2, and β-def3 expression levels within the 3 days of sampling, found in the milk of animals with sub- and clinical mastitis, indicates the loss of antiinflammatory protection of the affected cow's udder. In contrast, the stable increase of IL-2 and TGF-β1 positive cells observed in the milk of mastitis-affected cows, and the similar expression of these factors in the milk of healthy animals, indicate the possible lack of involvement of these cytokines at an early stage of udder inflammation.