Exposure of a Corneal Epithelial Cell Line (hTCEpi) to Demodex-Associated Bacillus Proteins Results in an Inflammatory Response

Novel Peptides with Dual Properties for Treating Pseudomonas aeruginosa Keratitis: Antibacterial and Corneal Wound Healing

The corneal epithelium is a layer in the anterior part of eye that contributes to light refraction onto the retina and to the ocular immune defense. Although an intact corneal epithelium is an excellent barrier against microbial pathogens and injuries, corneal abrasions can lead to devastating eye infections. Among them, Pseudomonas aeruginosa-associated keratitis often results in severe deterioration of the corneal tissue and even blindness. Hence, the discovery of new drugs able not only to eradicate ocular infections, which are often resistant to antibiotics, but also to elicit corneal wound repair is highly demanded. Recently, we demonstrated the potent antipseudomonal activity of two peptides, Esc(1-21) and its diastereomer Esc(1-21)-1c. In this study, by means of a mouse model of P. aeruginosa keratitis and an in vivo corneal debridement wound, we discovered the efficacy of these peptides, particularly Esc(1-21)-1c, to cure keratitis and to promote corneal wound healing. This latter property was also supported by in vitro cell scratch and ELISA assays. Overall, the current study highlights Esc peptides as novel ophthalmic agents for treating corneal infection and injury, being able to display a dual function, antimicrobial and wound healing, rarely identified in a single peptide at the same micromolar concentration range.

Current research and clinical trends in rosacea pathogenesis

Background

Rosacea is a common and complex chronic inflammatory skin disorder, the pathophysiology and etiology of which remain unclear. Recently, significant new insights into rosacea pathogenesis have enriched and reshaped our understanding of the disorder. A systematic analysis based on current studies will facilitate further research on rosacea pathogenesis.

Objective

To establish an international core outcome and knowledge system of rosacea pathogenesis and develop a challenge, trend and hot spot analysis set for research and clinical studies on rosacea using bibliometric analysis and data mining.

Methods

A search of the WoS, and PubMed, MEDLINE, Embase and Cochrane collaboration databases was conducted to perform visual bibliometric and data analysis.

Results

A total of 2,654 studies were used for the visualization and 302 of the 6,769 outcomes for data analysis. It reveals an increased trend line in the field of rosacea, in which its fast-growing pathogenesis attracted attention closely related to risk, comorbidity and therapeutic strategies. The rosacea pathogenesis has undergone the great development on immunology, microorganisms, genes, skin barriers and neurogenetics. The major of studies have focused on immune and microorganisms. And keyword visualization and data analyses demonstrated the cross-talk between cells or each aspect of pathogenesis, such as gene-gene or gene-environment interactions, and neurological mechanisms associated with the rosacea phenotype warrant further research.

Limitations

Inherent limitations of bibliometrics; and reliance on research and retrospective studies.

Conclusions

The understanding of rosacea's pathogenesis has been significantly enhanced with the improved technology and multidisciplinary integration, but high-quality, strong evidence in favor of genomic and neurogenic requires further research combined with a better understanding of risks and comorbidities to guide clinical practice.

Ocular Comorbidities in Rosacea: A Case-Control Study Based on Seven Institutions

Rosacea is a facial inflammatory dermatosis that is linked with various systemic illnesses. With regards to the eye, rosacea patients have been described to manifest ocular surface changes, such as blepharitis and conjunctivitis. However, studies that examine the association of rosacea with a wider array of ocular diseases are limited. Thus, our aim was to identify the range of ocular comorbidities in the Korean patient population and create a reference data set. A multi-institutional, case-control study was conducted, where 12,936 rosacea patients and an equal number of sex- and age-matched control subjects were extracted over a 12-year period. We were able to discover a notable association between rosacea and blepharitis (adjusted odds ratio (aOR) 3.44; 95% confidence interval, 2.71–4.36, p < 0.001), conjunctivitis (aOR 1.65; 95% CI, 1.50–1.82, p < 0.001), glaucoma (aOR 1.93; 95% CI, 1.70–2.20, p < 0.001), dry eye syndrome (aOR 1.89; 95% CI, 1.70–2.09, p < 0.001), and chalazion (aOR 3.26; 95% CI, 1.41–7.57, p = 0.006) from logistic regression analysis. Female subjects and individuals younger than 50 exclusively showed higher odds for chalazion. Our study suggests that ocular comorbidities (i.e., glaucoma, dry eye syndrome, and chalazion as well as blepharitis and conjunctivitis) are more prevalent among Koreans with rosacea. Clinicians should proactively check ocular symptoms in rosacea and employ joint care with an ophthalmologist in cases of need.

[Demodex and ocular surface disease]

Demodex is a saprophytic mite of the ocular adnexa, which can in certain circumstances proliferate on the skin of the face and on the eyelid margins. It is involved in facial rosacea (especially in the papulopustular form) and in the development or aggravation of anterior and/or posterior blepharitis or even keratoconjunctivitis, often in association with cutaneous lesions ; the pathophysiology is often multifactorial. Symptoms are non-specific, but the presence of cylindrical sleeves on the eyelashes is very suggestive of infestation, and certain techniques of biomicroscopic examination or imaging, such as confocal microscopy in vivo, allow direct visualization of the parasite. Parasitological examination of the eyelashes can confirm the diagnosis and can be improved by good sampling technique. Eyelid hygiene and oil-based ointments are the cornerstone of treatment. New specific treatments, in particular topical treatments based on tea tree oil, ivermectin, as well as pulsed light therapy and micro-exfoliation of the eyelid margin, can help to reduce the parasitic load and improve symptoms.

Update on the pathogenesis and management of ocular rosacea: an interdisciplinary review

PURPOSE

Rosacea is one of the most common conditions affecting the ocular surface. The purpose of this review is to provide an update on the pathogenesis and treatment of rosacea based on the dermatology and ophthalmology literatures.

METHODS

Literature searches were conducted for rosacea and ocular rosacea. Preference was given to systematic reviews, meta-analysis, case-controlled studies, and documented case reports while excluding poorly documented case studies and commentaries. The data were examined and independently analyzed by more than two of the authors.

RESULTS

Rosacea is a complex inflammatory condition involving the pilosebaceous unit. Its underlying mechanism involves an interplay of the microbiome, innate immunity, adaptive immunity, environmental triggers, and neurovascular sensitivity. The latest classification of rosacea includes three dermatologic subgroups and a fourth subgroup, ocular rosacea. Ocular rosacea clinically displays many features that are analogous to the cutaneous disease, such as lid margin telangiectasia and phlyctenulosis. The role of environmental triggers in the exacerbation of ocular rosacea appears to be understudied. While lid hygiene and systemic treatment with tetracycline drugs remain the mainstay of treatment for ocular rosacea, newer dermatologic targets and therapies may have potential application for the eye disease.

CONCLUSIONS

Ocular rosacea appears to embody many of the manifestation of the dermatologic disease. Hence, the basic pathophysiologic mechanisms of the ocular and cutaneous disease are likely to be shared. Better understanding of the ocular surface microbiome and the immunologic mechanisms, may lead to novel approaches in the management of ocular rosacea.

Topical ivermectin-metronidazole gel therapy in the treatment of blepharitis caused by Demodex spp.: A randomized clinical trial

PURPOSE

To evaluate the efficacy of topical ivermectin-metronidazole combined therapy in the management of Demodex-associatedblepharitis.

METHODS

Sixty patients with a diagnosis of Demodex-associatedblepharitis were recruited in a randomized clinical trial. Thirty receiving topical ivermectin (0.1%)-metronidazole (1%) gel treatment on days 0, 15 and 30. Thirty additional patients were used as a control group receiving vehicle on days 0, 15 and 30. The primary efficacy measure was the number of Demodex spp. mitesin the eyelashes of patients. The secondary outcomes included clinical improvement of signs and adverse events.

RESULTS

Complete eradication of Demodex spp. was found in 96.6% of patients in the treatment group. Furthermore, a significant reduction of inflammation signs were found in all treated patients versus controls. None of the patients experienced any adverse effects associated with the treatment.

CONCLUSION

Demodex infection was controlled satisfactorily with the ivermectin (0.1%)-metronidazole (1%) gel, and no adverse effects were observed. Application of this gel for the treatment of different parasitic infections of the eyelids could be feasible, and this requires further exploration.

Rosacea: a wholistic review and update from pathogenesis to diagnosis and therapy

Rosacea is a chronic inflammatory disorder of the central face with multiple overlapping presentations. Recent advancements are reshaping our understanding of rosacea from both a pathophysiologic perspective and clinical approach to therapy, introducing novel agents that have improved patient outcomes and reduced morbidity. In this article, we aim to outline the advancements in understanding, diagnosing, and managing rosacea and to familiarize physicians with the literature, thereby allowing us to better practice safe and effective medicine.

The Effect of Calcium and Glucose Concentration on Corneal Epithelial Cell Lines Differentiation, Proliferation, and Focal Adhesion Expression

It is known that culture media composition can affect cell behavior, morphology, and gene expression. However, in the case of corneal epithelial cells, the combined role of calcium and glucose concentration in media has not previously been examined. In this study, a human immortalized corneal epithelial cell line was used to examine the effect of glucose and calcium concentrations on these cells. Cell metabolic activity, cell growth curve analysis, and relative gene and protein expression of proliferative marker extracellular related kinase (ERK) were used to study proliferation. Corneal epithelial stem cell marker NP63 and mature epithelial marker cytokeratin 3 (CK3) were analyzed by using reverse transcription polymerase chain reaction (RT-PCR) and immunocytochemistry. Focal adhesions were examined by using immunocytochemistry. Cells cultured in both low-glucose, high-calcium (LG-HC) media and high-glucose, low-calcium (HG-LC) media showed similar results in both RT-PCR and immunocytochemistry analysis. NP63 expression was significantly lower and CK3 expression was higher in these groups compared with cells cultured in commercial media. NP63 and CK3 expression was also analyzed by using immunocytochemistry, which confirmed these findings. The high-glucose, high-calcium-fed cells showed the lowest expression of all markers and no gene expression of CK3. This was deemed the most unsuitable media formulation for this cell line. Focal adhesion expression was the lowest in the high-calcium, high-glucose-fed cells, with the most even distribution of this among the commercial media group. Overall, this study showed that varying glucose and calcium concentrations can have significant effects on differentiation, proliferation, focal adhesions, and metabolic activity of this cell line. It seems that an LG-HC and HG-LC formulation were interchangeable with similar proliferative and differentiation effects.

Analysis of the effect of temperature on protein abundance in Demodex-associated Bacillus oleronius

A potential role for bacteria in the induction of rosacea has been suggested. The aim of this work was to characterise the effect of temperature on the production of immunostimulatory proteins by Bacillus oleronius-a bacterium to which rosacea patients show sera reactivity and which was originally isolated from a Demodex mite from a rosacea patient. The affected skin of rosacea patients is at a higher temperature than unaffected skin, and it was postulated that this might alter the protein expression pattern of B. oleronius. B. oleronius growth was reduced at 37°C compared to 30°C but resulted in increased expression of the immune-reactive 62kDa protein (1.65 fold [P < 0.05]). Proteomic analysis revealed increased abundance of a wide range of proteins involved in the stress response (e.g. stress proteins [21.7-fold increase], phosphocarrier protein HPr [438.5-fold increase], 60 kDa chaperonin [12.6-fold increase]). Proteins decreased in abundance after growth at 37°C included ferredoxin (325-fold decrease) and peptidase (244-fold decrease). This work indicates that the increased skin temperature of rosacea patients may alter the growth and protein production pattern of B. oleronius and lead to the greater production of immuo-stimulatory proteins.

Endosymbiosis and its significance in dermatology

Proposed at the beginning of the twentieth century to explain the origin of eukaryotic organelles from prokaryotes, endosymbiosis is now medically defined by various interaction patterns between microorganisms and their residing hosts, best exemplified by the bacterial endosymbiont Wolbachia identified in arthropods and filarial nematodes, which can influence normal development, reproduction, survival and transmission of the hosts. Based on the transmission modes, vertical or horizontal, and the function of the endosymbionts, the host-symbiont dependence can be divided into primary or secondary. In dermatology, the role of endosymbionts in skin ectoparasitosis has aroused great interests in the past years. Riesia pediculicola is a primary bacterial endosymbiont in body lice Pediculus humanus, and supplement their hosts with vitamin B, especially pantothenic acid. In cimicosis, the Gram-negative Wolbachia can synthesize biotin and riboflavin, which are crucial for the growth and reproduction of the bedbug Cimex lectularius. In human demodicosis and rosacea, further study is required to prove the pathogenic role of the Gram-negative bacteria Bacillus oleronius or the Gram-positive bacteria Bacillus cereus demonstrated in the Demodex mites. The high infection rate of adult female ticks Ixodes ricinus with the Gram-negative bacteria Midichloria mitochondrii present in the mitochondria in diverse ovarian cells, with the high seroprevalence rate in tick-exposed subjects, raises the possibility that this non-pathogenic endosymbiont may play a role in immune response and successful transmission of the tick-borne pathogen. The anaerobic protozoan Trichomonas vaginalis and bacteria Mycoplasma hominis are two obligate parasites in the urogenital epithelium, with partially overlapping symptoms. Intracellular localization of Mycoplasma hominis can avoid host immune response and penetration of antibiotics, while Trichomonas vaginalis infected with Mycoplasma hominis seems to have a higher cytopathic activity and amoeboid transformation rate. Further study on the biology and pathogenesis of different endosymbionts in dermatological parasitosis will help for the development of new treatment modalities.

A Clinical Scoring System for Diagnosis of Ocular Demodicosis

Background

Demodex may cause chronic and refractory blepharitis with associated ocular surface problems, and its diagnosis and treatment can be quite challenging. In this study, our aim was to assess the efficacy of tea tree oil in Demodex treatment on caucasian patients in an industrialized region of Turkey, and to develop a systematic scoring system for extremely accurate diagnosis in the absence of advanced facilities.

Material/Methods

Charts of 412 patients with blepharitis were reviewed. A group of 39 out of 412 cases were identified as chronic and treatment-refractory, and therefore were enrolled in this study. Eyelashes from each of the lower and upper eyelids of both eyes were evaluated at ×40 and ×100 magnification using light microscopy. Treatment was started with 4% tea tree oil eyelid gel and 10% eyelash shampoo. Symptoms and findings were scored according to the most common complaints.

Results

The mean age of the patients was 54.1±15.4 years. Seventeen (43.5%) patients were male and 22 (56.5%) patients were female. In 30 out of the 39 patients (76.9%) D. folliculorum was detected. Symptoms disappeared in 25 patients. The mean score of patients who were Demodex-negative was 2.7±1.0, and the mean score of patients who were Demodex-positive was 3.8±1.6 (p=0.047). Ninety-four percent of those with a score of 4 and over were found to be Demodex-positive (p=0.025).

Conclusions

Treatment with tea tree oil can be successful. If there is no facility to identify Demodex under light microscopy, we recommend starting treatment for patients who have scores of 4 and over using the scoring chart developed in this study.

Activation of Neutrophils via IP3 Pathway Following Exposure to Demodex-Associated Bacterial Proteins

Rosacea is a chronic inflammatory condition that predominantly affects the skin of the face. Sera from rosacea patients display elevated reactivity to proteins from a bacterium (Bacillus oleronius) originally isolated from a Demodex mite from a rosacea patient suggesting a possible role for bacteria in the induction and persistence of this condition. This work investigated the ability of B. oleronius proteins to activate neutrophils and demonstrated activation via the IP3 pathway. Activated neutrophils displayed increased levels of IP1 production, F-actin formation, chemotaxis, and production of the pro-inflammatory cytokines IL-1β and IL-6 following stimulation by pure and crude B. oleronius protein preparations (2 μg/ml), respectively. In addition, neutrophils exposed to pure and crude B. oleronius proteins (2 μg/ml) demonstrated increased release of internally stored calcium (Ca(2+)), a hallmark of the IP3 pathway of neutrophil activation. Neutrophils play a significant role in the inflammation associated with rosacea, and this work demonstrates how B. oleronius proteins can induce neutrophil recruitment and activation.