LL-37 regulates the overexpression of vascular endothelial growth factor (VEGF) and c-IAP-2 in human keratinocytes

Rosacea and Dry Eye Disease

Ocular rosacea is a chronic potentially sight-threatening inflammatory condition, which can occur in approximately 20% of patients without skin involvement. However, an accurate diagnosis of ocular rosacea has not been defined yet due to its rather nonspecific symptoms and clinical findings. Therefore, this article updates the current recommendations for diagnosis and treatment of ocular rosacea and the previously published consensus recommendations from the ROSCO expert panel on the management of rosacea.

Antimicrobial peptides - Unleashing their therapeutic potential using nanotechnology

Antimicrobial peptides (AMPs) are potent, mostly cationic, and amphiphilic broad-spectrum host defense antimicrobials that are produced by all organisms ranging from prokaryotes to humans. In addition to their antimicrobial actions, they modulate inflammatory and immune responses and promote wound healing. Although they have clear benefits over traditional antibiotic drugs, their wide therapeutic utilization is compromised by concerns of toxicity, stability, and production costs. Recent advances in nanotechnology have attracted increasing interest to unleash the AMPs' immense potential as broad-spectrum antibiotics and anti-biofilm agents, against which the bacteria have less chances to develop resistance. Topical application of AMPs promotes migration of keratinocytes and fibroblasts, and contributes significantly to an accelerated wound healing process. Delivery of AMPs by employing nanotechnological approaches avoids the major disadvantages of AMPs, such as instability and toxicity, and provides a controlled delivery profile together with prolonged activity. In this review, we provide an overview of the key properties of AMPs and discuss the latest developments in topical AMP therapy using nanocarriers. We use chronic hard-to-heal wounds-complicated by infections, inflammation, and stagnated healing-as an example of an unmet medical need for which the AMPs' wide range of therapeutic actions could provide the most potential benefit. The use of innovative materials and sophisticated nanotechnological approaches offering various possibilities are discussed in more depth.

Antimicrobial Peptides: The Promising Therapeutics for Cutaneous Wound Healing

Chronic wound infections have caused an increasing number of deaths and economic burden, which necessitates wound treatment options. Hitherto, the development of functional wound dressings has achieved reasonable progress. Antibacterial agents, growth factors, and miRNAs are incorporated in different wound dressings to treat various types of wounds. As an effective antimicrobial agent and emerging wound healing therapeutic, antimicrobial peptides (AMPs) have attracted significant attention. The present study focuses on the application of AMPs in wound healing and discusses the types, properties and formulation strategies of AMPs used for wound healing. In addition, the clinical trial and the current status of studies on "antimicrobial peptides and wound healing" are elaborated through bibliometrics. Also, the challenges and opportunities for further development and utilization of AMP formulations in wound healing are discussed.

Role of Atypical Chemokines and Chemokine Receptors Pathways in the Pathogenesis of COPD

Chronic obstructive pulmonary disease (COPD) represents a heightened inflammatory response in the lung generally resulting from tobacco smoking-induced recruitment and activation of inflammatory cells and/or activation of lower airway structural cells. Several mediators can modulate activation and recruitment of these cells, particularly those belonging to the chemokines (conventional and atypical) family. There is emerging evidence for complex roles of atypical chemokines and their receptors (such as high mobility group box 1 (HMGB1), antimicrobial peptides, receptor for advanced glycosylation end products (RAGE) or toll-like receptors (TLRs)) in the pathogenesis of COPD, both in the stable disease and during exacerbations. Modulators of these pathways represent potential novel therapies for COPD and many are now in preclinical development. Inhibition of only a single atypical chemokine or receptor may not block inflammatory processes because there is redundancy in this network. However, there are many animal studies that encourage studies for modulating the atypical chemokine network in COPD. Thus, few pharmaceutical companies maintain a significant interest in developing agents that target these molecules as potential antiinflammatory drugs. Antibody-based (biological) and small molecule drug (SMD)-based therapies targeting atypical chemokines and/or their receptors are mostly at the preclinical stage and their progression to clinical trials is eagerly awaited. These agents will most likely enhance our knowledge about the role of atypical chemokines in COPD pathophysiology and thereby improve COPD management.

Ocular manifestations of rosacea: A clinical review

Ocular rosacea is a chronic inflammatory condition that can occur in the absence of cutaneous features. The most common ocular features are chronic blepharoconjunctivitis with eyelid margin inflammation and meibomian gland dysfunction. Corneal complications include corneal vascularization, ulceration, scarring and, rarely, perforation. Diagnosis is largely based on clinical signs, although it is often delayed in the absence of cutaneous changes, particularly in children. It can also be associated with systemic disorders such as cardiovascular disease. Management ranges from local therapy to systemic treatment, depending on the severity of the disease. In this review, we describe the epidemiology, pathophysiology, clinical features and treatment of rosacea and ocular rosacea.

Patent evaluation of WO2019209182 (A1) 2019-10-31 (Conjugated Oligoelectrolytes as Antimicrobial Agents)

INTRODUCTION

The insurgence of antibiotic resistance represents one of the biggest public health challenges of our times. During the years, different compounds were developed to fight against resistant bacterial cells, exploiting different mechanisms of action.

AREAS COVERED

The patent application describes a set of antimicrobial compounds bearing to the class of the conjugated oligoelectrolytes (COEs). These are molecules characterized by hydrophobic conjugated backbone and terminal polar ionic pendants, able to intercalate into lipid bilayers of bacterial cells. The patent reports the preparation of 15 new compounds and the evaluation of their antimicrobial effect against ESKAPE pathogens ( E nterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp.).

EXPERT OPINION

The preparation of the compounds claimed is simple and the preliminary activity data are very interesting. Among the claimed compounds, COE-D8, COE-T42, and COE-T62 have the ability to strongly inhibit the bacterial growth at doses similar to the ones of last resource antibiotics. Unfortunately, no in-vivo data are reported. Moreover, the presence of several quaternary amines limits the potential application of these compounds only to topical uses.

MrgX2‑mediated internalization of LL‑37 and degranulation of human LAD2 mast cells

LL‑37 is the sole antimicrobial peptide of human cathelicidin comprising 37 amino acids, which is expressed mainly in epithelial cells and neutrophils, and activates mast cells. In the present study, in order to elucidate the mechanism of mast cell activation by LL‑37, the associations between the internalization of LL‑37 and Mas‑related gene X2 (MrgX2)‑mediated mast cell activation (degranulation) was investigated using the human mast cell line, LAD2. LL‑37 was rapidly internalized into the cells, and induced degranulation, as assessed by the extracellular release of β‑hexosaminidase. Pertussis toxin, a G‑protein inhibitor, significantly suppressed the internalization of LL‑37 and the degranulation of LAD2 cells. Furthermore, small interfering (si)‑RNA‑mediated knockdown of MrgX2, a putative G protein‑coupled receptor for LL‑37, inhibited the internalization of LL‑37 and degranulation of LAD2 cells. Notably, LL‑37 internalization was enhanced by the stable expression of MrgX2 in HMC‑1 and 293 cells. In addition, the internalized LL‑37 mainly colocalized with MrgX2 in the perinuclear region of LAD2 cells. Furthermore, neuraminidase treatment, which removes negatively charged sialic acid from the cell surface, markedly reduced the internalization of LL‑37 and degranulation of LAD2 cells, and clathrin‑mediated endocytosis inhibitors (dynasore and chlorpromazine) inhibited the internalization and degranulation of LAD2 cells. Taken together, these observations indicated that LL‑37 may bind the negatively charged cell surface molecules, rapidly internalize into the cells via clathrin‑mediated endocytosis and interact with MrgX2 to activate mast cells (LAD2 cells).

Nanomedicines and gene therapy for the delivery of growth factors to improve perfusion and oxygenation in wound healing

Oxygen plays a key role in wound healing, and hypoxia is a major cause of wound healing impairment; therefore, treatments to improve hemodynamics and increase wound oxygenation are of particular interest for the treatment of chronic wounds. This article describes the roles of oxygen and angiogenesis in wound healing as well as the tools used to evaluate tissue oxygenation and perfusion and then presents a review of nanomedicines and gene therapies designed to improve perfusion and oxygenation and accelerate wound healing.

EPR monitoring of wound oxygenation as a biomarker of response to gene therapy encoding hCAP-18/LL37 peptide

PURPOSE

To investigate the value of electron paramagnetic resonance oximetry to follow oxygenation in wounds treated by a plasmid-encoding host defense peptide hCAP-18/LL37.

METHODS

Flaps were created on diabetic mice (7- or 12-week-old db/db mice) presenting different levels of microangiopathy. The hCAP-18/LL37-encoding plasmids were administered in wounds by electroporation. Low-frequency electron paramagnetic resonance oximetry using lithium phthalocyanine as the oxygen sensor was used to monitor wound oxygenation in flaps during the healing process. Flaps were analyzed by immunohistochemistry to assess hypoxia and cell proliferation. Kinetics of closure was also assessed in excisional skin wounds.

RESULTS

A reoxygenation of the flap was observed during the healing process in the 7-week-old db/db treated mice, but not in the untreated mice and the 12-week-old mice. Histological studies demonstrated less hypoxic regions and higher proportion of proliferating cells in hCAP-18/LL37-treated flaps in the 7-week-old db/db treated mice compared with untreated mice. Consistently, the kinetics of excisional wound closure was improved by hCAP-18/LL37 treatment in the 7-week-old db/db but not in the 12-week-old mice.

CONCLUSIONS

Oxygenation measured by electron paramagnetic resonance oximetry is a promising biomarker of response to treatments designed to modulate wound oxygenation. Magn Reson Med 79:3267-3273, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Pathogenesis and clinical presentation of rosacea as a key for a symptom-oriented therapy

Rosacea is a common chronic inflammatory skin disorder that typically occurs in adults and affects the face. Synonyms of rosacea include "acne rosacea", "couperose" and "facial erythrosis", in German also "Kupferfinne" and "Rotfinne". The disorder is characterised by a chronic and flaring course and is caused by a genetically predisposed, multifactorial process. A higher incidence is seen in people with fair skin and a positive family history. The characteristic rosacea symptoms manifest primarily, but not exclusively centrofacially, with forehead, nose, chin and cheeks significantly affected. Based on the various main symptoms a classification of the individual clinical pictures can be performed. However, a classification often does not reflect the clinical reality, since the various symptoms commonly coexist. The present review provides an introduction on pathogenesis and clinical manifestations of rosacea and prefers a symptom-oriented therapy approach.

Pathogenese und Klinik der Rosazea als Schlüssel für eine symptomorientierte Therapie

Rosazea ist eine häufige chronisch-entzündliche Hauterkrankung, die typischerweise bei Erwachsenen vorkommt und das Gesicht betrifft. Synonyme der Rosazea sind Acne rosacea, Kupferfinne, Rotfinne, Couperose und Rosacea. Die Erkrankung ist durch einen chronischen und schubartigen Verlauf gekennzeichnet und wird durch ein genetisch prädisponiertes, multifaktorielles Geschehen bedingt. Ein vermehrtes Auftreten wird bei hellem Hauttyp und positiver Familienanamnese verzeichnet. Die charakteristischen Rosazea-Symptome manifestieren sich vorwiegend, aber nicht ausschließlich zentrofazial, wobei Stirn, Nase, Kinn und die Wangen maßgeblich betroffen sind. Dabei werden unterschiedliche Hauptsymptome voneinander unterschieden, anhand derer eine Klassifikation der verschiedenen klinischen Bilder vorgenommen werden kann. Eine Klassifizierung wird oftmals jedoch nicht der klinischen Realität gerecht, da die verschiedenen Symptome häufig gemeinsam auftreten. Diese Übersichtarbeit führt in die Pathogenese und Klinik der Rosazea ein und plädiert für einen symptomorientierten Therapieansatz.

Antimicrobial Peptides: An Emerging Category of Therapeutic Agents

Antimicrobial peptides (AMPs), also known as host defense peptides, are short and generally positively charged peptides found in a wide variety of life forms from microorganisms to humans. Most AMPs have the ability to kill microbial pathogens directly, whereas others act indirectly by modulating the host defense systems. Against a background of rapidly increasing resistance development to conventional antibiotics all over the world, efforts to bring AMPs into clinical use are accelerating. Several AMPs are currently being evaluated in clinical trials as novel anti-infectives, but also as new pharmacological agents to modulate the immune response, promote wound healing, and prevent post-surgical adhesions. In this review, we provide an overview of the biological role, classification, and mode of action of AMPs, discuss the opportunities and challenges to develop these peptides for clinical applications, and review the innovative formulation strategies for application of AMPs.

Cathelicidin PR-39 peptide inhibits hypoxia/reperfusion-induced kidney cell apoptosis by suppression of the endoplasmic reticulum-stress pathway

Ischemia/reperfusion injury (IRI) is a major cause of acute kidney damage, which often occurs in deceased donor kidney transplants. Cathelicidin PR-39 peptide possesses anti-inflammatory and wound repair effects through tissue angiogenesis and anti-apoptosis. This study assessed the role of PR-39 in anti-apoptosis in vitro using a lentiviral vector with a kidney specific promoter (KSP) to drive PR-39 expression. Our data revealed that PR-39 peptide was specifically over-expressed in kidney-derived HK-2 cells, but was scarcely detected in non-kidney tissue-derived cells. PR-39 over-expression had a protective role in the hypoxia/re-oxygenation (H/R) treated cells. The anti-apoptotic activity of PR-39 peptide was mediated by the inhibition of caspase-2, caspase-12 and caspase-3 activity in the endoplasmic reticulum (ER) stress-induced apoptotic pathway. It was also revealed that the anti-apoptotic effect of PR-39 peptide was mediated by an apoptosis-related protein, cellular inhibitor apoptosis protein-2 (c-IAP-2). Taken together, the current data demonstrate that PR-39 expression driven by KSP could prevent kidney damage (apoptosis) from IRI via the ER stress-induced apoptotic pathway.

Potential role of recombinant adeno-associated virus human thioredoxin-PR39 in cell and vascular protection against hypoxia

The aim of the present study was to successfully construct a recombinant adeno-associated virus (rAAV) vector containing the human thioredoxin (hTRX)-PR39 chimeric gene (rAAV/hTRX-PR39), and verify that the vector was able to maintain a sustained, stable and efficient expression to achieve protein production in the cell. In the present study, a chicken embryo model was utilized to analyze the therapeutical effect of rAAV/hTRX-PR39 in cerebral ischemia diseases. ECV304 cells were transfected with rAAV/hTRX-PR39 and incubated under conditions of 20, 5 and 1% O₂. Subsequently, the expression levels of vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor (VEGFR)-1, VEGFR-2, fibroblast growth factor receptor (FGFR)-1 and syndecan-4 were detected by reverse transcription-quantitative polymerase chain reaction. Under hypoxic conditions, the mRNA expression levels of VEGF, VEGFR-1, VEGFR-2, FGFR-1 and syndecan-4 were found to increase in the PR39-transfected group when compared with the control group, while no statistically significant difference was observed between the PR39-transfected group and the control group under conditions of 20% O₂. In addition, hTRX-PR39 was shown to increase the density of the vasculature and the survival rate of the chick embryos. Under hypoxic conditions, it was hypothesized that rAAV/hTRX-PR39 was capable of promoting angiogenesis, which may subsequently protect the cells from impairment by hypoxia. In conclusion, rAAV/hTRX-PR39 was demonstrated to promote vascularization and cell survival in hypoxia; thus, rAAV/hTRX-PR39 may have potential for use in therapy targeting cerebral ischemia.

Cross Talk between Proliferative, Angiogenic, and Cellular Mechanisms Orchestred by HIF-1α in Psoriasis

Psoriasis is a chronic inflammatory skin disease where the altered regulation in angiogenesis, inflammation, and proliferation of keratinocytes are the possible causes of the disease, and the transcription factor “hypoxia-inducible factor 1-alpha” (HIF-1α) is involved in the homeostasis of these three biological phenomena. In this review, the role of HIF-1α in the cross talk between the cytokines and cells of the immunological system involved in the pathogenesis of psoriasis is discussed.

Peptidoglycan from Staphylococcus aureus has an anti-apoptotic effect in HaCaT keratinocytes mediated by the production of the cellular inhibitor of apoptosis protein-2

Colonization of epithelium by microorganisms leads to inflammatory responses. In some cases an anti-apoptotic response involving the cellular inhibitor of apoptosis protein-2 (cIAP-2) also occurs. Although strong expression of cIAP-2 has been observed in lesional skin from psoriatic patients and in HaCaT keratinocytes treated with peptidoglycan (PGN) from Staphylococcus aureus, anti-apoptotic responses induced in the skin by cIAP-2 have seldom been studied. In this study, the effect of PGN on TNF-α-induced apoptotic HaCaT keratinocytes was assessed. Morphological analysis, quantification of cells with DNA fragmentation and active caspase-3 detection was performed to assess apoptotic cell death. Greater LL-37 and cIAP-2 production was found in keratinocytes stimulated with PGN than in non-treated cells (P < 0.05). In comparison with cells treated with TNF-α only, a significant reduction in apoptotic cell death was observed when HaCaT were pretreated with PGN before inducing apoptosis with TNF-α (P < 0.05). In addition, an inhibitor of cIAP-2 activity (LCL161) stopped the PGN effect. These findings show that PGN from S. aureus has an anti-apoptotic effect in keratinocytes mediated by cIAP-2 production, suggesting that this anti-apoptotic activity could favor proliferation of keratinocytes in psoriasis.

Skin electroporation of a plasmid encoding hCAP-18/LL-37 host defense peptide promotes wound healing

Host defense peptides, in particular LL-37, are emerging as potential therapeutics for promoting wound healing and inhibiting bacterial growth. However, effective delivery of the LL-37 peptide remains limiting. We hypothesized that skin-targeted electroporation of a plasmid encoding hCAP-18/LL-37 would promote the healing of wounds. The plasmid was efficiently delivered to full-thickness skin wounds by electroporation and it induced expression of LL-37 in the epithelium. It significantly accelerated reepithelialization of nondiabetic and diabetic wounds and caused a significant VEGFa and interleukin (IL)-6 induction. IL-6 was involved in LL-37-mediated keratinocyte migration in vitro and IL-6 neutralizing antibodies delivered to mice were able to suppress the wound healing activity of the hCAP-18/LL-37 plasmid. In a hindlimb ischemia model, electroporation of the hCAP-18/LL-37 plasmid increased blood perfusion, reduced muscular atrophy, and upregulated the angiogenic chemokines VEGFa and SDF-1a, and their receptors VEGF-R and CXCR-4. These findings demonstrate that a localized gene therapy with LL-37 is a promising approach for the treatment of wounds.

Recombinant adeno-associated virus delivered human thioredoxin-PR39 prevents hypoxia-induced apoptosis of ECV304 cells

Human thioredoxin and antibacterial peptide, PR39, have been shown to have potent antioxidant effects that may prolong survival of cells during hypoxia. The pSSCMV/human thioredoxin-PR39 vector was successfully constructed in this study and used to infect ECV304 cells. Transfected ECV304 cells were incubated at 1%, 5% hypoxic, and normal oxygen conditions. We found that the number of apoptotic cells after transfection with recombinant adeno-associated virus-human thioredoxin -PR39 was significantly lower than controls, suggesting a protective effect of the recombinant human thioredoxin-PR39 protein on hypoxic cells.

Angiogenesis in cutaneous disease: part II

This review will discuss the role of angiogenesis in specific cutaneous diseases. Scientific evidence now points to the role of angiogenesis in tumor development and many other cutaneous disorders. Angiogenesis is a complex process that involves angiogenic growth factors and inhibitors, many of which could be a potential target for pharmacologic intervention. Antiangiogenic agents have recently been applied to dermatologic diseases with promising efficacy.

LEARNING OBJECTIVES

After completing this learning activity, participants should be able to recognize cutaneous diseases where angiogenesis is likely to be an important factor, recognize scenarios where angiogenic therapy may be useful in conjunction with traditional therapies, and be able to use angiogenic-mediating agents in the treatment of dermatologic disease.

Human antimicrobial protein hCAP18/LL-37 promotes a metastatic phenotype in breast cancer

Introduction

Human cathelicidin antimicrobial protein, hCAP18, and its C-terminal peptide LL-37 is a multifunctional protein. In addition to being important in antimicrobial defense, it induces chemotaxis, stimulates angiogenesis and promotes tissue repair. We previously showed that human breast cancer cells express high amounts of hCAP18, and hypothesised that hCAP18/LL-37 may be involved in tumour progression.

Methods

hCAP18 mRNA was quantified in 109 primary breast cancers and compared with clinical findings and ERBB2 mRNA expression. Effects of exogenous LL-37 and transgenic overexpression of hCAP18 on ErbB2 signalling were investigated by immunoblotting using extracts from breast cancer cell lines ZR75-1 and derivatives of MCF7. We further analysed the impact of hCAP18/LL-37 on the morphology of breast cancer cells grown in soft agar, on cell migration and on tumour development in severe combined immunodeficiency (SCID) mice.

Results

The expression of hCAP18 correlated closely with that of ERBB2 and with the presence of lymph node metastases in oestrogen receptor-positive tumours. hCAP18/LL-37 amplified Heregulin-induced mitogen-activated protein kinase (MAPK) signalling through ErbB2, identifying a functional association between hCAP18/LL-37 and ErbB2 in breast cancer. Treatment with LL-37 peptide significantly stimulated the migration of breast cancer cells and their colonies acquired a dispersed morphology indicative of increased metastatic potential. A truncated version of LL-37 competitively inhibited LL-37 induced MAPK phosphorylation and significantly reduced the number of altered cancer cell colonies induced by LL-37 as well as suppressed their migration. Transgenic overexpression of hCAP18 in a low malignant breast cancer cell line promoted the development of metastases in SCID mice, and analysis of hCAP18 transgenic tumours showed enhanced activation of MAPK signalling.

Conclusions

Our results provide evidence that hCAP18/LL-37 contributes to breast cancer metastasis.