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

Rosacea, microbiome and probiotics: the gut-skin axis

Rosacea is an inflammatory skin disease involving diverse symptoms with a variable clinical progress which can severely impact the patient's quality of life as well as their mental health. The pathophysiological model of rosacea involves an unbalanced immune system predisposed to excessive inflammation, in addition to vascular and nervous alterations, being certain cutaneous microorganisms' triggers of the symptoms onset. The gut-skin axis explains a bidirectional interaction between skin and gut microbiota in some inflammatory skin diseases such as atopic dermatitis, psoriasis, or rosacea. The introduction and consolidation of the next-generation sequencing in recent years has provided unprecedented information about the microbiome. However, the characterization of the gut and skin microbiota and the impact of the gut-skin axis in patients with rosacea has been little explored, in contrast to other inflammatory skin diseases such as atopic dermatitis or psoriasis. Furthermore, the clinical evolution of patients with rosacea is not always adequate and it is common for them to present a sustained symptomatology with frequent flare-ups. In this context, probiotic supplementation could improve the clinical evolution of these patients as happens in other pathologies. Through this review we aim to establish and compile the basics and directions of current knowledge to understand the mechanisms by which the microbiome influences the pathogenesis of rosacea, and how modulation of the skin and gut microbiota could benefit these patients.

Demodicosis in Different Age Groups and Alternative Treatment Options-A Review

Infestation with Demodex mites is a common occurrence, especially in adults and the elderly. More recent attention has been paid to the presence of Demodex spp. mites in children, even ones without comorbidities. It causes both dermatological and ophthalmological problems. The presence of Demodex spp. is often asymptomatic, thus it is suggested to include parasitological investigation tests in dermatological diagnostics, in addition to bacteriological analysis. Literature reports show that Demodex spp. are related to the pathogenesis of numerous dermatoses, including rosacea or demodicosis gravis, and common eye pathologies reported by patients such as dry eye syndrome or ocular surface inflammatory conditions, such as blepharitis, chalazia, Meibomian gland dysfunction, and keratitis. Treatment of patients is a challenge and is usually prolonged, therefore it is important to carefully diagnose and properly select the therapy regimen for the treatment to be successful, and with minimal side effects, especially for young patients. Apart from the use of essential oils, research is ongoing for new alternative preparations active against Demodex sp. Our review was focused on the analysis of the current literature data on the available agents in the treatment of demodicosis in adults and children.

Skincare in Rosacea from the Cosmetologist's Perspective: A Narrative Review

Rosacea is a common skin disease that affects about 5% of the general population. Its symptoms include telangiectasia, persistent erythema, burning/stinging sensation, dry skin sensation, and pruritus. It is characterized by a chronic course with frequent exacerbation. It often coexists with anxiety and depression, reducing the quality of life of affected patients. The etiopathogenesis of rosacea is complex and not fully elucidated; hence, there is no causative effective treatment. In this review, we highlight the role of a cosmetologist in the treatment of rosacea and the maintenance of remission. As part of medical treatment, patients are advised to introduce lifestyle changes and use proper skin care; a cosmetologist can help educate patients affected with rosacea, create effective home care programs for skin care, and support them with treatments in beauty salons. Proper skin care is essential, including the use of dermocosmetics, cleansing of the skin, and frequent visits to beauty salons for tailored apparatus procedures. A cosmetologist is more accessible to patients and can help implement healthy daily habits, including skin care and eating habits, as well as support and mediate good communication between the patient and the patient's treating physician, thereby improving compliance and ensuring long-term satisfactory outcomes.

Mechanisms of rosacea pathogenesis. A phenotypic approach to therapeutic tactics

Rosacea is a widespread disease worldwide, affecting 5.5% of the human population and accompanied by a significant deterioration in the patient's quality of life. Currently, there are two classifications of rosacea, the first of which is based on a subtype approach (erythematous-telangiectatic, papulo-pustular, phimatous and ophthalmological subtypes), or on an individual analysis of the presented phenotype of rosacea. New data on the pathophysiology of rosacea have emerged, which show that genetic factors and environmental components can cause the initiation and exacerbation of rosacea due to a violation of the regulation of the innate and adaptive immune system. In addition, trigger factors can directly interact with the cutaneous nervous system and, with the help of neurovascular and neuroimmune active neuropeptides, lead to the manifestation of rosacea foci. The main mechanisms of rosacea pathogenesis are currently: activation of the immune system, disorders of neuro-immune regulation, genetic predisposition. New pathogenetic mechanisms of rosacea make it possible to continue the diagnostic search and therapeutic approaches with the personalization of management tactics for each patient, depending on the prevalence of clinical features of the course of the disease. It is necessary to evaluate the advantages and disadvantages of subtypical and phenotypic approaches to rosacea classification and choose the most optimal one. The article presents arguments on this issue, and also suggests assessing the need to switch to a new classification in order to improve the effectiveness of therapy and improve the quality of life of patients.

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.

Sodium Bituminosulfonate Used to Treat Rosacea Modulates Generation of Inflammatory Mediators by Primary Human Neutrophils

Background

Sodium bituminosulfonate is derived from naturally occurring sulphur-rich oil shale and is used for the treatment of the inflammatory skin disease rosacea. Major molecular players in the development of rosacea include the release of enzymes that process antimicrobial peptides which, together with reactive oxygen species (ROS) and vascular endothelial growth factor (VEGF), promote pro-inflammatory processes and angiogenesis. The aim of this study was to address the molecular mechanism(s) underlying the therapeutic benefit of the formulation sodium bituminosulfonate dry substance (SBDS), which is indicated for the treatment of skin inflammation, including rosacea.

Methods

We investigated whether SBDS regulates the expression of cytokines, the release of the antimicrobial peptide LL-37, calcium mobilization, proteases (matrix metalloproteinase, elastase, kallikrein (KLK)5), VEGF or ROS in primary human neutrophils. In addition, activity assays with 5-lipoxygenase (5-LO) and recombinant human MMP9 and KLK5 were performed.

Results

We observed that SBDS reduces the release of the antimicrobial peptide LL-37, calcium, elastase, ROS and VEGF from neutrophils. Moreover, KLK5, the enzyme that converts cathelicidin to LL-37, and 5-LO that produces leukotriene (LT)A₄, the precursor of LTB₄, were both inhibited by SBDS with an IC₅₀ of 7.6 µg/mL and 33 µg/mL, respectively.

Conclusion

Since LTB₄ induces LL-37 which, in turn, promotes increased intracellular calcium levels and thereby, ROS/VEGF/elastase release, SBDS possibly regulates the LTB₄/LL-37/calcium – ROS/VEGF/elastase axis by inhibiting 5-LO and KLK5. Additional direct effects on other pro-inflammatory pathways such as ROS generation cannot be ruled out. In summary, SBDS reduces the generation of inflammatory mediators from human neutrophils possibly accounting for its anti-inflammatory effects in rosacea.

Interactions between immune system and the microbiome of skin, blood and gut in pathogenesis of rosacea

The increasingly wide use of next-generation sequencing technologies has revolutionised our knowledge of microbial environments associated with human skin, gastrointestinal tract and blood. The collective set of microorganisms influences metabolic processes, affects immune responses, and so directly or indirectly modulates disease. Rosacea is a skin condition of abnormal inflammation and vascular dysfunction, and its progression is affected by Demodex mites on the skin surface. When looking into the effects influencing development of rosacea, it is not only the skin microbiome change that needs to be considered. Changes in the intestinal microbiome and their circulating metabolites, as well as changes in the blood microbiome also affect the progression of rosacea. Recent research has confirmed the increased presence of bacterial genera like Acidaminococcus and Megasphera in the intestinal microbiome and Rheinheimera and Sphingobium in the blood microbiome of rosacea patients. In this review we discuss our current knowledge of the interactions between the immune system and the skin, gut and blood microbiome, with particular attention to rosacea diagnostic opportunities.

Comparison of the efficacy of tea tree (Melaleuca alternifolia) oil with other current pharmacological management in human demodicosis: A Systematic Review

Various treatments are found to be moderately effective in managing Demodex-related diseases except tea tree oil (TTO) and terpinen-4-ol (T4O), which showed superior miticidal and anti-inflammatory effects in numerous clinical studies. Their possible effects include lowering mite counts, relieving Demodex-related symptoms, and modulating the immune system. This review summarizes the current clinical topical and oral treatments in human demodicosis, their possible mechanisms of action, side-effects and resistance in treating this condition. TTO (especially T4O) is found to be the most effective followed by metronidazole, ivermectin and permethrin in managing the disease. This is because TTO has anti-parasitic, anti-bacterial, anti-fungal, anti-inflammatory and wound-healing effects. Furthermore, nanoTTO can even release its contents into fungus and Pseudomonas biofilms. Combinations of different treatments are occasionally needed for refractory cases, especially for individuals with underlying genetic predisposal or are immuno-compromised. Although the current treatments show efficacy in controlling the Demodex mite population and the related symptoms, further research needs to be focused on the efficacy and drug delivery technology in order to develop alternative treatments with better side-effects profiles, less toxicity, lower risk of resistance and are more cost-effective.

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.

[Rosacea: New data for better care]

In the last 10 years, numerous studies have been published that throw new light on rosacea, in all areas of the disease. This overview summarises all the key developments, based on the indexed bibliography appearing in Medline between 2007 and 2017. Recent epidemiological data show that the prevalence of the disease is doubtless greater than estimated hitherto (more than 10% of adults in some countries) and that we should not overlook rosacea in subjects with skin phototypes V or VI, a condition that exists on all continents. A new classification of rosacea by phenotype comprising major and minor signs has been put forward; it provides a more rational approach to suitable management based upon symptoms, the severity of which may be graded into 5 classes. The treatments with the best-demonstrated efficacy (updated Cochrane study) are topical metronidazole, azelaic acid and ivermectin, and oral doxycycline; isotretinoin is effective against resistant forms but is off-label. In ocular rosacea, the reference treatment is doxycycline in combination with topical therapy of the eyelids. The physiopathology is complex and involves several factors: vascular (vasodilatation, vascular growth factors), neurovascular (hypersensitivity, neuropathic pain, neuropeptides), infectious (Demodex folliculorum and its microbiota) and inflammatory (abnormal production of pro-inflammatory peptides of the innate immune system). In addition, there is a genetic predisposition as demonstrated by the weight of familial history and comparison of homozygous and heterozygous twins. There is also activation of several genes involved in immunity, inflammation and lipid metabolism; the theory of hydrolipid film anomalies has been posited once more. There has thus been a tremendous leap forward in the field of rosacea research, with therapeutic progress and improved understanding of the underlying mechanisms, which should enable the future development of more targeted treatments as well as global management of this disease, which has major social and emotional consequences on the life of patients.

Association study of Demodex bacteria and facial dermatoses based on DGGE technique

The role of bacteria is unclear in the facial skin lesions caused by Demodex. To shed some light on this issue, we conducted a case-control study comparing cases with facial dermatoses with controls with healthy skin using denaturing gradient gel electrophoresis (DGGE) technique. The bacterial diversity, composition, and principal component were analyzed for Demodex bacteria and the matched facial skin bacteria. The result of mite examination showed that all 33 cases were infected with Demodex folliculorum (D. f), whereas 16 out of the 30 controls were infected with D. f, and the remaining 14 controls were infected with Demodex brevis (D. b). The diversity analysis showed that only evenness index presented statistical difference between mite bacteria and matched skin bacteria in the cases. The composition analysis showed that the DGGE bands of cases and controls were assigned to 12 taxa of 4 phyla, including Proteobacteria (39.37-52.78%), Firmicutes (2.7-26.77%), Actinobacteria (0-5.71%), and Bacteroidetes (0-2.08%). In cases, the proportion of Staphylococcus in Firmicutes was significantly higher than that in D. f controls and D. b controls, while the proportion of Sphingomonas in Proteobacteria was significantly lower than that in D. f controls. The between-group analysis (BGA) showed that all the banding patterns clustered into three groups, namely, D. f cases, D. f controls, and D. b controls. Our study suggests that the bacteria in Demodex should come from the matched facial skin bacteria. Proteobacteria and Firmicutes are the two main taxa. The increase of Staphylococcus and decrease of Sphingomonas might be associated with the development of facial dermatoses.

Rosacea: Molecular Mechanisms and Management of a Chronic Cutaneous Inflammatory Condition

Rosacea is a chronic cutaneous inflammatory disease that affects the facial skin. Clinically, rosacea can be categorized into papulopustular, erythematotelangiectatic, ocular, and phymatous rosacea. However, the phenotypic presentations of rosacea are more heterogeneous. Although the pathophysiology of rosacea remains to be elucidated, immunologic alterations and neurovascular dysregulation are thought to have important roles in initiating and strengthening the clinical manifestations of rosacea. In this article, we present the possible molecular mechanisms of rosacea based on recent laboratory and clinical studies. We describe the genetic predisposition for rosacea along with its associated diseases, triggering factors, and suggested management options in detail based on the underlying molecular biology. Understanding the molecular pathomechanisms of rosacea will likely aid toward better comprehending its complex pathogenesis.