Caveolin-1 as a pathophysiological factor and target in psoriasis

Is the endotoxin-complement cascade the major driver in lipedema?

Lipedema is a poorly understood disorder of adipose tissue characterized by abnormal but symmetrical deposition of subcutaneous white adipose tissue (WAT) in proximal extremities. Here, we propose that the underlying cause for lipedema could be triggered by a selective accumulation of bacterial lipopolysaccharides (LPS; also known as endotoxin) in gluteofemoral WAT. Together with a malfunctioning complement system, this induces low-grade inflammation in the depot and raises its uncontrollable expansion. Correspondingly, more attention should be paid in future research to the endotoxemia prevalent in patients with lipedema. We would like to propose that proper management of endotoxemia can reduce the progression and even improve the state of disease in patients with lipedema.

Application of dual-frequency ultrasound for reduction of perilesional edema and ecchymosis after rhinoseptoplasty

OBJECTIVES

Biological aspect and clinical research demonstrated that dual-frequency ultrasound (local dynamic micro-massage, LDM) waves of very high frequency can significantly modify cellular signaling providing anti-inflammatory and anti-fibrotic effects. During the recent past, these waves were successfully applied for the treatment of various inflammatory skin conditions, hypertrophic scars, and chronical wounds. Since the main complications after rhinoseptoplasty are caused by excessive inflammatory reactions and development of fibrosis along nasal implants which can lead to a revision rhinoseptoplasty, in this retrospective multicenter blinded study we have evaluated the efficacy of LDM ultrasound for the treatment of the postoperative perilesional ecchymosis and edema in patients after rhinoseptoplasty.

METHODS

Twenty-four patients received daily LDM treatment (study group) for 5 days starting from the first day postoperative, whereas 24 patients (control group) were treated with conventional ice packs. Dynamic reduction of the postoperative perilesional ecchymosis and edema was followed up, and the total duration of these side effects was determined within specific paranasal anatomical areas.

RESULTS

Post-rhinoseptoplasty ecchymosis and edema were observed in the areas of anterior cheek, lower eyelids, and upper eyelids. Duration of the postoperative perilesional edema was significantly reduced in the group treated with LDM (1.9 ± 0.9 days) compared with control group (4.5 ± 2.1 days). Duration of the ecchymosis was also significantly reduced in LDM group (2.8 ± 1.4 days) compared with controls (7.4 ± 2.8 days). Postoperative patient satisfaction in LDM-treated and control groups was 3.1 ± 1.3 and 1.5 ± 0.7, respectively, demonstrating significantly higher satisfaction in LDM-treated group.

CONCLUSIONS

This study proved that the post-rhinoseptoplasty group treated with LDM ultrasound showed a significantly shorter duration of the postsurgical perilesional ecchymosis and edema, with no substantial adverse effects other than those observed in the control group. It can be suggested that ultrasound treatment can serve as an alternative option for the noninvasive management of postoperative perilesional ecchymosis and edema.

Downregulation of Caveolae-Associated Proteins in Psoriasis: A Case Series Study

We have previously identified that a structural membrane protein Caveolin-1 (Cav1) is involved in the regulation of aberrant keratinocyte proliferation and differentiation. The aim of this study was to elucidate the role of Cav1, Caveolin-2 (Cav2), and Cavin-1 in the pathogenesis of psoriasis vulgaris and between psoriasis subtypes. We utilized human biopsies from validated cases of psoriasis vulgaris (n = 21) at the University of Miami Hospital and compared the expression of Cav1, Cav2, and Cavin-1 by immunohistochemistry staining with that in normal healthy age-/sex-/location-matched skin (n = 15) and chronic spongiotic dermatitis skin samples (as control inflammatory skin condition) and quantified using QuPath. Distinct subtypes of psoriasis included guttate, inverse, nail, plaque, palmoplantar, and pustular. All biopsy samples exhibited a trend toward downregulation of Cav1, with nail, plaque, and palmoplantar psoriasis exhibiting the most pronounced effects. Only nail and pustular psoriasis samples exhibited significant downregulation of Cav2 and Cavin-1, suggesting Cav1 to be the main caveolar contributor to the pathogenesis of psoriasis. Together, these data support caveolae as pathophysiological targets in nail and pustular psoriasis, whereas Cav1 seems to be a general biomarker of multiple subtypes of psoriasis.

The Pressurized Skin: A Review on the Pathological Effect of Mechanical Pressure on the Skin from the Cellular Perspective

Since human skin is the primary interface responding to external mechanical stimuli, extrinsic forces can disrupt its balanced microenvironment and lead to cutaneous lesions. We performed this review to delve into the pathological effects of mechanical pressure on skin from the cellular perspective. Fibroblasts of different subsets act as heterogeneous responders to mechanical load and express diverse functionalities. Keratinocytes relay mechanical signals through mechanosensitive receptors and the ensuing neurochemical cascades to work collaboratively with other cells and molecules in response to pressure. Mast cells release cytokines and neuropeptides, promoting inflammation and facilitating interaction with sensory neurons, while melanocytes can be regulated by pressure through cellular and molecular crosstalk. Adipocytes and stem cells sense pressure to fine-tune their regulations of mechanical homeostasis and cell differentiation. Applying mechanical pressure to the skin can induce various changes in its microenvironment that potentially lead to pathological alterations, such as ischemia, chronic inflammation, proliferation, regeneration, degeneration, necrosis, and impaired differentiation. The heterogeneity of each cellular lineage and subset from different individuals with various underlying skin conditions must be taken into consideration when discussing the pathological effects of pressure on the skin. Thus, elucidating the mechanotransduction and mechanoresponsive pathways from the cellular viewpoint is crucial in diagnosing and managing relevant dermatological disorders.

Impact of NB-UVB phototherapy on Caveolin-1 expression in chronic plaque psoriasis

BACKGROUND

Caveolin-1 (Cav-1) is a significant structural and regulatory constituent of cell membranes that has been implicated in cell kinetics and inflammation.

OBJECTIVE

To assess Cav-1 expression in psoriasis before and after phototherapy.

PATIENTS AND METHODS

Thirty psoriasis cases and 30 healthy controls were recruited. Cases were managed with narrow band-ultraviolet B (NB-UVB) phototherapy at frequency three times per week for 12 weeks. From every case, two biopsy specimens were gained from psoriatic lesions (pre and post phototherapy), in addition to one from apparently normal skin of psoriasis cases. Regarding the control group, one biopsy was taken from a matched site. All were studied for Cav-1 antibody immuno-expression.

RESULTS

There was a significant decrease in Cav-1 expression in psoriatic lesions compared to both the apparently normal skin of psoriasis patients and standard control skin of healthy individuals. After NB-UVB phototherapy, significant upregulation of Cav-1 immunostaining score was observed in previously psoriatic skin when compared to that before treatment. In addition, there were significant negative correlations between Cav-1 immunostaining score and the clinical scores of psoriasis severity including; the erythema, scaling, and induration (ESI) score and the patient psoriasis area and severity index (PASI) score.

CONCLUSION

Induction of Cav-1 expression may be a likely pathway for the effectiveness of NB-UVB in psoriasis. Cav-1 may be a useful marker for evaluation of psoriasis severity, disease progression, and therapeutic efficacy.

Extracellular vesicles: a comprehensive review of their roles as biomarkers and potential therapeutics in psoriasis and psoriatic arthritis

Psoriasis is a chronic immune-mediated condition that affects the skin and joints, with current treatments still unable to offer a cure and long-term use of treatments posing health risks. Understanding the pathogenesis of the disease has helped identify new targets that have allowed for the expansion of the therapeutic arsenal. Extracellular vesicles (EVs) have recently emerged as pathophysiological mediators of psoriasis, and there have been increasing reports of EVs as potential biomarkers and therapeutics. Given their innate role as natural vehicles for cell-to-cell communication, EVs have vast potential in their ability to determine disease status based on EV-specific cargo as well as act as therapeutics because of their anti-inflammatory properties and potential for enhancement. In this review we summarize the role of EVs in the pathogenesis of psoriasis and discuss EVs as both diagnostic and therapeutic agents.

Involvement of caveolin-1 in skin diseases

The skin is the outermost layer and largest organ in the human body. Since the skin interfaces with the environment, it has a variety of roles, including providing a protective barrier against external factors, regulating body temperature, and retaining water in the body. It is also involved in the immune system, interacting with immune cells residing in the dermis. Caveolin-1 (CAV-1) is essential for caveolae formation and has multiple functions including endocytosis, lipid homeostasis, and signal transduction. CAV-1 is known to interact with a variety of signaling molecules and receptors and may influence cell proliferation and migration. Several skin-related disorders, especially those of the inflammatory or hyperproliferative type such as skin cancers, psoriasis, fibrosis, and wound healing, are reported to be associated with aberrant CAV-1 expression. In this review, we have explored CAV-1 involvement in skin physiology and skin diseases.

Molecular Mechanisms Underlying Caveolin-1 Mediated Membrane Curvature

Caveolin-1 is one of the main protein components of caveolae that acts as a mechanosensor at the cell membrane. The interactions of caveolin-1 with membranes have been shown to lead to complex effects such as curvature and the clustering of specific lipids. Here, we review the emerging concepts on the molecular interactions of caveolin-1, with a focus on insights from coarse-grain molecular dynamics simulations. Consensus structural models of caveolin-1 report a helix-turn-helix core motif with flanking domains of higher disorder that could be membrane composition dependent. Caveolin-1 appears to be mainly surface-bound and does not embed very deep in the membrane to which it is bound. The most interesting aspect of caveolin-1 membrane binding is the interplay of cholesterol clustering and membrane curvature. Although cholesterol has been reported to cluster in the vicinity of caveolin-1 by several approaches, simulations show that the clustering is maximal in membrane leaflet opposing the surface-bound caveolin-1. The intrinsic negative curvature of cholesterol appears to stabilize the negative curvature in the opposing leaflet. In fact, the simulations show that blocking cholesterol clustering (through artificial position restraints) blocks membrane curvature, and vice versa. Concomitant with cholesterol clustering is sphingomyelin clustering, again in the opposing leaflet, but in a concentration-dependent manner. The differential stress due to caveolin-1 binding and the inherent asymmetry of the membrane leaflets could be the determinant for membrane curvature and needs to be further probed. The review is an important step to reconcile the molecular level details emerging from simulations with the mesoscopic details provided by state of the art experimental approaches.

Phenotypical Conversions of Dermal Adipocytes as Pathophysiological Steps in Inflammatory Cutaneous Disorders

Adipocytes from the superficial layer of subcutaneous adipose tissue undergo cyclic de- and re-differentiation, which can significantly influence the development of skin inflammation under different cutaneous conditions. This inflammation can be connected with local loading of the reticular dermis with lipids released due to de-differentiation of adipocytes during the catagen phase of the hair follicle cycle. Alternatively, the inflammation parallels a widespread release of cathelicidin, which typically takes place in the anagen phase (especially in the presence of pathogens). Additionally, trans-differentiation of dermal adipocytes into myofibroblasts, which can occur under some pathological conditions, can be responsible for the development of collateral scarring in acne. Here, we provide an overview of such cellular conversions in the skin and discuss their possible involvement in the pathophysiology of inflammatory skin conditions, such as acne and psoriasis.

The Systematic Analysis of Exercise Mechanism in Human Diseases

Background

As a part of a healthy lifestyle, exercise has been proven to be beneficial for the treatment of diseases and the prognosis of patients. Based on this, our research focuses on the impact of exercise on human health.

Methods

To study and analyze the samples in the GSE18966 gene expression profile, we first performed an analysis on the differential expressed genes (DEGs) through GEO2R, and then the DEGs enrichment in Gene Ontology functions and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways through the Database for Annotation, Visualization and Integrated Discovery database was conducted. Then, we delved into the gene set enrichment in KEGG through gene set enrichment analysis. After that, we achieved the construction of the protein-protein interaction (PPI) network of DEGs based on the Search Tool for the Retrieval of Interacting Genes online database, and the hub genes were screened and identified.

Results

We identified 433 upregulated DEGs and 186 downregulated DEGs from the samples before and after exercise in GSE18966. Through analysis, it was found that these DEGs-enriched pathways, such as the VEGF signaling pathway, the Wnt signaling pathway, and the insulin signaling pathway, were all involved in the regulation of various diseases. Then, GSEA analysis revealed that glycosaminoglycan biosynthesis chondroitin sulfate, type II diabetes mellitus, and basal cell carcinoma were related with exercise samples. The effects of these pathways on various diseases could be improved through exercise. Finally, 3 upregulated hub genes (VEGFA, POMC, and NRAS) and 3 downregulated hub genes (HRAS, NCOR1, and CAV1) were identified through the PPI network.

Conclusions

The bioinformatic analysis of samples before and after exercise provides key pathways and genes related to exercise to regulate various diseases, which confirms that exercise has an important influence on the treatment of many diseases.

Skin aging: Dermal adipocytes metabolically reprogram dermal fibroblasts

Emerging data connects the aging process in dermal fibroblasts with metabolic reprogramming, provided by enhanced fatty acid oxidation and reduced glycolysis. This switch may be caused by a significant expansion of the dermal white adipose tissue (dWAT) layer in aged, hair-covered skin. Dermal adipocytes cycle through de-differentiation and re-differentiation. As a result, there is a strongly enhanced release of free fatty acids into the extracellular space during the de-differentiation of dermal adipocytes in the catagen phase of the hair follicle cycle. Both caveolin-1 and adiponectin are critical factors influencing these processes. Controlling the expression levels of these two factors also offers the ability to manipulate the metabolic preferences of the different cell types within the microenvironment of the skin, including dermal fibroblasts. Differential expression of adiponectin and caveolin-1 in the various cell types may also be responsible for the cellular metabolic heterogeneity within the cells of the skin.

Glucocorticoid-mediated induction of caveolin-1 disrupts cytoskeletal organization, inhibits cell migration and re-epithelialization of non-healing wounds

Although impaired keratinocyte migration is a recognized hallmark of chronic wounds, the molecular mechanisms underpinning impaired cell movement are poorly understood. Here, we demonstrate that both diabetic foot ulcers (DFUs) and venous leg ulcers (VLUs) exhibit global deregulation of cytoskeletal organization in genomic comparison to normal skin and acute wounds. Interestingly, we found that DFUs and VLUs exhibited downregulation of ArhGAP35, which serves both as an inactivator of RhoA and as a glucocorticoid repressor. Since chronic wounds exhibit elevated levels of cortisol and caveolin-1 (Cav1), we posited that observed elevation of Cav1 expression may contribute to impaired actin-cytoskeletal signaling, manifesting in aberrant keratinocyte migration. We showed that Cav1 indeed antagonizes ArhGAP35, resulting in increased activation of RhoA and diminished activation of Cdc42, which can be rescued by Cav1 disruption. Furthermore, we demonstrate that both inducible keratinocyte specific Cav1 knockout mice, and MβCD treated diabetic mice, exhibit accelerated wound closure. Taken together, our findings provide a previously unreported mechanism by which Cav1-mediated cytoskeletal organization prevents wound closure in patients with chronic wounds.

Pathophysiological Roles of Stress-Activated Protein Kinases in Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is one of the most symptomatic progressive fibrotic lung diseases, in which patients have an extremely poor prognosis. Therefore, understanding the precise molecular mechanisms underlying pulmonary fibrosis is necessary for the development of new therapeutic options. Stress-activated protein kinases (SAPKs), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (p38) are ubiquitously expressed in various types of cells and activated in response to cellular environmental stresses, including inflammatory and apoptotic stimuli. Type II alveolar epithelial cells, fibroblasts, and macrophages are known to participate in the progression of pulmonary fibrosis. SAPKs can control fibrogenesis by regulating the cellular processes and molecular functions in various types of lung cells (including cells of the epithelium, interstitial connective tissue, blood vessels, and hematopoietic and lymphoid tissue), all aspects of which remain to be elucidated. We recently reported that the stepwise elevation of intrinsic p38 signaling in the lungs is correlated with a worsening severity of bleomycin-induced fibrosis, indicating an importance of this pathway in the progression of pulmonary fibrosis. In addition, a transcriptome analysis of RNA-sequencing data from this unique model demonstrated that several lines of mechanisms are involved in the pathogenesis of pulmonary fibrosis, which provides a basis for further studies. Here, we review the accumulating evidence for the spatial and temporal roles of SAPKs in pulmonary fibrosis.

A Cell Membrane-Level Approach to Cicatricial Alopecia Management: Is Caveolin-1 a Viable Therapeutic Target in Frontal Fibrosing Alopecia?

Irreversible destruction of the hair follicle (HF) in primary cicatricial alopecia and its most common variant, frontal fibrosing alopecia (FFA), results from apoptosis and pathological epithelial-mesenchymal transition (EMT) of epithelial HF stem cells (eHFSCs), in conjunction with the collapse of bulge immune privilege (IP) and interferon-gamma-mediated chronic inflammation. The scaffolding protein caveolin-1 (Cav1) is a key component of specialized cell membrane microdomains (caveolae) that regulates multiple signaling events, and even though Cav1 is most prominently expressed in the bulge area of human scalp HFs, it has not been investigated in any cicatricial alopecia context. Interestingly, in mice, Cav1 is involved in the regulation of (1) key HF IP guardians (TGF-β and α-MSH signaling), (2) IP collapse inducers/markers (IFNγ, substance P and MICA), and (3) EMT. Therefore, we hypothesize that Cav1 may be an unrecognized, important player in the pathobiology of cicatricial alopecias, and particularly, in FFA, which is currently considered as the most common type of primary lymphocytic scarring alopecia in the world. We envision that localized therapeutic inhibition of Cav1 in management of FFA (by cholesterol depleting agents, i.e., cyclodextrins/statins), could inhibit and potentially reverse bulge IP collapse and pathological EMT. Moreover, manipulation of HF Cav1 expression/localization would not only be relevant for management of cicatricial alopecia, but FFA could also serve as a model disease for elucidating the role of Cav1 in other stem cell- and/or IP collapse-related pathologies.

[Significance of exosomes in cardiology: heralds of cardioprotection]

Los exosomas tienen un papel clave en la comunicación intercelular. Debido a sus múltiples interacciones, estas estructuras cumplen con el papel de «mensajeros» de forma dinámica, transportando su contenido a células blanco específicas y generando nuevas señales celulares. En este artículo se describen algunas de las proteínas, lípidos y ácidos nucleicos que son transportados por estas vesículas y que se han relacionado con cardioprotección, con la finalidad de proporcionar información y generar interés sobre la relevancia de los exosomas como posibles blancos diagnósticos y terapéuticos.

Acoustic Waves in Axonal Membrane and Caveolins are the New Targets for Pain Treatment with High Frequency Ultrasound

Reciprocal interaction between electrical and mechanical waves observed in axonal membrane during its excitation leads to a paradigm shift in pain research making the uncoupling of electro-mechanical signals an interesting target in pain treatment. This uncoupling can be realized either through direct disturbance of the mechanical surface waves in axonal membrane or through shifting of the thermodynamic state of this membrane far from its phase transition point. Both effects can be effectively realized through application of the very high frequency ultrasound waves. Additional target for application of ultrasound in pain treatment is the caveolin-1, which is abundantly present in Schwann cells as well as in the non-axonal tissues. Both targets demonstrate frequency-dependent reactions, thus making a very high frequency ultrasound a promising treatment modality in pain treatment.

The MMP14-caveolin axis and its potential relevance for lipoedema

Lipoedema is associated with widespread adipose tissue expansion, particularly in the proximal extremities. The mechanisms that drive the development of lipoedema are unclear. In this Perspective article, we propose a new model for the pathophysiology of lipoedema. We suggest that lipoedema is an oestrogen-dependent disorder of adipose tissue, which is triggered by a dysfunction of caveolin 1 (CAV1) and subsequent uncoupling of feedback mechanisms between CAV1, the matrix metalloproteinase MMP14 and oestrogen receptors. In addition, reduced CAV1 activity also leads to the activation of ERα and impaired regulation of the lymphatic system through the transcription factor prospero homeobox 1 (PROX1). The resulting upregulation of these factors could effectively explain the main known features of lipoedema, such as adipose hypertrophy, dysfunction of blood and lymphatic vessels, the overall oestrogen dependence and the associated sexual dimorphism, and the mechanical compliance of adipose tissue.

Coupling of melanocyte signaling and mechanics by caveolae is required for human skin pigmentation

Tissue homeostasis requires regulation of cell-cell communication, which relies on signaling molecules and cell contacts. In skin epidermis, keratinocytes secrete factors transduced by melanocytes into signaling cues promoting their pigmentation and dendrite outgrowth, while melanocytes transfer melanin pigments to keratinocytes to convey skin photoprotection. How epidermal cells integrate these functions remains poorly characterized. Here, we show that caveolae are asymmetrically distributed in melanocytes and particularly abundant at the melanocyte-keratinocyte interface in epidermis. Caveolae in melanocytes are modulated by ultraviolet radiations and keratinocytes-released factors, like miRNAs. Preventing caveolae formation in melanocytes increases melanin pigment synthesis through upregulation of cAMP signaling and decreases cell protrusions, cell-cell contacts, pigment transfer and epidermis pigmentation. Altogether, we identify that caveolae serve as molecular hubs that couple signaling outputs from keratinocytes to mechanical plasticity of pigment cells. The coordination of intercellular communication and contacts by caveolae is thus crucial to skin pigmentation and tissue homeostasis.

The importance of caveolins and caveolae to dermatology: Lessons from the caves and beyond

Caveolae are flask-shaped invaginations of the cell membrane rich in cholesterol and sphingomyelin, with caveolin proteins acting as their primary structural components that allow compartmentalization and orchestration of various signalling molecules. In this review, we discuss how pleiotropic functions of caveolin-1 (Cav1) and its intricate roles in numerous cellular functions including lipid trafficking, signalling, cell migration and proliferation, as well as cellular senescence, infection and inflammation, are integral for normal development and functioning of skin and its appendages. We then examine how disruption of the homeostatic levels of Cav1 can lead to development of various cutaneous pathophysiologies including skin cancers, cutaneous fibroses, psoriasis, alopecia, age-related changes in skin and aberrant wound healing and propose how levels of Cav1 may have theragnostic value in skin physiology/pathophysiology.

Caveolin as a Universal Target in Dermatology

Caveolin-1 is strongly expressed in different dermal and subdermal cells and physically interacts with signaling molecules and receptors, among them with transforming growth factor beta (TGF-β), matrix metalloproteinases, heat shock proteins, toll-like and glucocorticoid receptors. It should therefore be heavily involved in the regulation of cellular signaling in various hyperproliferative and inflammatory skin conditions. We provide an overview of the role of the caveolin-1 expression in different hyperproliferative and inflammatory skin diseases and discuss its possible active involvement in the therapeutic effects of different well-known drugs widely applied in dermatology. We also discuss the possible role of caveolin expression in development of the drug resistance in dermatology. Caveolin-1 is not only an important pathophysiological factor in different hyperproliferative and inflammatory dermatological conditions, but can also serve as a target for their treatment. Targeted regulation of caveolin is likely to serve as a new treatment strategy in dermatology.

Caveolin-1 as a possible target in the treatment for acne

Expression of caveolin-1 (Cav-1) is an important pathophysiological factor in acne. Cav-1 strongly interacts with such well-recognized etiopathogenic factors such as hyperseborrhea, follicular hyperkeratinization and pathogenicity of Cutibacterium acnes. Cav-1 is a strong negative regulator of transforming growth factor beta (TGF-β) expression. It acts as a critical determinant of autophagy, which is significantly induced in acne lesions through C. acnes and by absorption of fatty acids. Cav-1 also demonstrates different correlations with the development of innate immunity. We propose that normalization of Cav-1 expression can serve as a target in anti-acne therapy.

Caveolin-1 in skin aging - From innocent bystander to major contributor

Caveolin-1 (Cav-1) appears to be both a pathophysiological contributor and a target in different inflammatory and hyperproliferative skin conditions as well as in skin aging. Skin fibroblasts demonstrate an up-regulation of Cav-1 expression both in chronological and UV-induced aging, and such an up-regulation was observed both in vitro and in vivo. Typical alterations in aging skin involve a reduction of the dermis thickness, a significant expansion of the dermal white adipose tissue as well as modifications of the content and distribution of hyaluronan, impairment of autophagic flux, a reduction of collagen expression and an increase in tissue inflammation. All of these phenomena can be connected with changes in Cav-1 expression in the aging skin. Modified expression of Cav-1 can also significantly influence the mechanical properties of individual skin layers, thus changing the total mechanical stability of the layered composite skin/WAT, leading to typical structural modifications of the skin surface in the aging skin. Selective reduction of Cav-1 expression has the potential to exert anti-aging effects on the skin.