Topical rapamycin systematically suppresses the early stages of pulsed dye laser-induced angiogenesis pathways

Effective treatment of corticosteroid-induced facial erythema using fractional radiofrequency microneedling

OBJECTIVES

To investigate the efficacy of Fractional Radiofrequency Microneedling (FRM) in treating corticosteroid-induced facial erythema.

METHODS

A retrospective study was conducted involving eight patients diagnosed as corticosteroid-induced facial erythema. Each patient underwent a single session of FRM. Evaluative measures included Clinician's Erythema Assessment (CEA), Patient's Self-Assessment (PSA), assessment of telangiectasia severity, procedure-associated pain (10-point scale), patient satisfaction (3-point scale) and secondary outcomes.

RESULTS

The study found a 75% success rate and 100% effectiveness rate in alleviating erythema symptoms. CEA and PSA scores decreased by 67.7% and 78.1%, respectively. No cases of erythema rebound were recorded during the 3-month follow-up period.

CONCLUSIONS

FRM demonstrated effectiveness and safety in treating facial erythema, offering promising advancement in dermatologic therapeutics.

Current clinical evidence is insufficient to support HMME-PDT as the first choice of treatment for young children with port wine birthmarks

BACKGROUND

Port wine birthmark (PWB) is a congenital vascular malformation of the skin. Pulsed dye laser (PDL) is the "gold standard" for the treatment of PWB globally. Hematoporphyrin monomethyl ether (HMME or hemoporfin)-mediated photodynamic therapy (HMME-PDT) has emerged as the first choice for PWB treatment, particularly for young children, in many major hospitals in China during the past several decades.

AIM

To evaluate whether HMME-PDT is superior to PDL by comparing the clinical efficacies of both modalities.

METHOD

PubMed records were searched for all relevant studies of PWB treatment using PDL (1988-2023) or HMME-PDT (2007-2023). Patient characteristics and clinical efficacies were extracted. Studies with a quartile percentage clearance or similar scale were included. A mean color clearance index (CI) per study was calculated and compared among groups. An overall CI (C0), with data weighted by cohort size, was used to evaluate the final efficacy for each modality.

RESULT

A total of 18 HMME-PDT studies with 3910 patients in China were eligible for inclusion in this analysis. Similarly, 40 PDL studies with 5094 patients from nine different countries were eligible for inclusion in this analysis. Over 58% of patients in the HMME-PDT studies were minors (<18 years old). A significant portion (21.3%) were young children (<3 years old). Similarly, 33.2% of patients in the PDL studies were minors. A small proportion (9.3%) was young children. The overall clearance rates for PDL were slightly, but not significantly, higher than those for HMME-PDT in cohorts with patients of all ages (C0, 0.54 vs. 0.48, p = 0.733), subpopulations with only minors (C0, 0.54 vs. 0.46, p = 0.714), and young children (C0, 0.67 vs. 0.50, p = 0.081). Regrettably, there was a lack of long-term data on follow-up evaluations for efficacy and impact of HMME-PDT on young children in general, and central nervous system development in particular, because their blood-brain barriers have a greater permeability as compared to adults.

CONCLUSION

PDL shows overall albeit insignificantly higher clearance rates than HMME-PDT in patients of all ages; particularly statistical significance is nearly achieved in young children. Collectively, current evidence is insufficient to support HMME-PDT as the first choice of treatment of PWBs in young children given: (1) overall inferior efficacy as compared to PDL; (2) risk of off-target exposure to meningeal vasculature during the procedure; (3) administration of steriods for mitigation of side effects; -and (4) lack of long-term data on the potential impact of HMME on central nervous system development in young children.

Initial research on the effect and mechanism of Tivozanib on pulsed dye laser induced angiogenesis

INTRODUCTION

Pulsed dye laser (PDL) is the main treatment for port wine stain (PWS), but a considerable number of patients show low clearances. The reason for the poor efficacy is related to PDL-induced angiogenesis. Vascular endothelial growth factor (VEGF) plays an important role in PDL-induced angiogenesis and can activate the tyrosine kinase activity of VEGF receptor (VEGFR) in endothelial cells. It triggers a full range of responses, and then participates in the regulation of angiogenesis. Tivozanib is an inhibitor of VEGFR tyrosine kinase activity, which can block the pro-angiogenic effect of VEGF and reduce vascular permeability.

METHOD

Different energy densities of PDL were used to irradiate the abdominal skin of rats. According to the general and pathological changes of the irradiated area, the energy density of 8 J/cm² with smaller scab and stronger vascular effect was selected for follow-up experiments. Divided the rat abdomen skin into four areas, irradiated three of them uniformly with an energy density of 8 J/cm² , and applied different concentrations of Tivozanib coating agent to the laser irradiation area, and grouped them as follows: (1) vacant group, (2) control group, (3) 0.5% Tivozanib group, (4) 1% Tivozanib group. Camera and dermoscopy were used to observe skin changes. Hematoxylin-eosin staining, immunohistochemical staining, and blood vessels were counted to detect dermal vascular regeneration. Transcriptome sequencing and real-time polymerase chain reaction (PCR) were conducted to elucidate the mechanism and validate the reliability.

RESULTS

The number of blood vessels in the 0.5% Tivozanib group and 1% Tivozanib group was significantly reduced on the 7, 10, and 14 days compared with the control group. The number of blood vessels in the 1% Tivozanib group was significantly reduced compared with the 0.5% Tivozanib group, indicating that Tivozanib successfully inhibited PDL-induced angiogenesis, and the inhibitory effect of 1% Tivozanib was more significant than that of 0.5% Tivozanib. Transcriptome sequencing results showed a total of 588 significantly differentially expressed genes, including 90 upregulated genes and 498 downregulated genes. Gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis showed that the significantly differentially expressed genes were mainly enriched in the metabolic pathways which were closely related to angiogenesis. Finally, real-time PCR was used to verify the genes with higher expression differences, the top ranking and closely related to angiogenesis, namely, Cxcl1, Cxcl2, Cxcl3, Cxcl6, Ccl3, Csf3, IL1β, iNOS, Mmp9, Mmp13, Plau, Ets1, Spp1, Nr4a1. The results were consistent with the trend of transcriptome sequencing results, which proved the reliability of this study.

CONCLUSION

This study explored the inhibitory effect of Tivozanib on PDL-induced angiogenesis, and provided a new idea for the treatment of clinical PWS. Transcriptome sequencing explored the mechanism and provided reliable clues for later in-depth research.

Topical metformin suppresses angiogenesis pathways induced by pulsed dye laser irradiation in animal models

Pulsed dye laser (PDL) is the first-line treatment for port-wine stain (PWS). However, only a small portion of the lesions could be completely cleared by PDL treatment, which might be related to the regeneration and revascularization of the vascular structures after laser irradiation. Recently, it is believed that the suppression of regeneration and revascularization of photocoagulated blood vessels can achieve a better therapeutic outcome. We use rabbit ear and SD rat as the animal models to investigate whether PDL-induced angiogenesis can be suppressed by topical metformin. Our results showed that topical application of metformin can effectively suppress the PDL-induced early stage of angiogenesis via inhibition of the AKT/mTOR/P70S6K pathway in animal models.

A Randomized Controlled Pilot Study: Combined 595-nm Pulsed Dye Laser Treatment and Oxymetazoline Hydrochloride Topical Cream Superior to Oxymetazoline Hydrochloride Cream for Erythematotelangiectatic Rosacea

Background and Objectives

We evaluated if oxymetazoline therapy combined with 595‐nm pulsed dye laser (PDL) will be more beneficial than topical oxymetazoline alone for the improvement of erythematotelangiectatic rosacea.

Study Design/Materials and Methods

This was a randomized, controlled, prospective clinical trial approved by an independent Institutional Review Board, which enrolled 34 patients with moderate to severe clinical erythema (CEA) into a two‐arm study of PDL with concomitant oxymetazoline cream (Arm 1) and oxymetazoline cream alone (Arm 2). Patients in Arm 1 were treated with 3 monthly laser sessions, which were started after 1 month of topical oxymetazoline cream. Thirty subjects continued with the study, and 25 subjects (Arm 1: 14, Arm 2: 11) completed the 6‐month follow‐up. With photographic comparison to baseline images, efficacy endpoints were based on clinical on‐site grading by both the investigator and the patient, using the grading tools for CEA, Global Aesthetic Improvement (GAI) assessment, vessel size improvement, and subject self‐assessment. These scales were assessed at baseline and/or at each clinical follow‐up at 1, 2, 3, and 6 months. Subject satisfaction as well as post‐treatment immediate response and treatment‐associated pain scores were also evaluated.

Results

Statistically significant improvement in CEA was seen in both arms at the 1‐, 2‐, and 3‐month post‐baseline visits (P < 0.01). Only Arm 1 presented statistically significant improvement in CEA (P < 0.001) at 6 months post baseline with a mean score of 1.6 (almost clear‐mild) compared with 3.2 at baseline. Arm 1 showed significantly greater mean vessel size improvement at 3 months (P < 0.01) and 6 months (P < 0.05) post baseline compared to Arm 2. Significantly greater improvement (P < 0.05) in the investigator GAI score was reported at the 2‐ and 6‐month follow‐ups compared with Arm 2. Subject GAI scores showed statistically significant greater improvement in Arm 1 compared with Arm 2 at both the 3‐ and 6‐month follow‐ups (P < 0.01). There were no complications or long‐term effects associated with PDL or topical oxymetazoline treatments.

Conclusion

The prospective trial verifies a safe, enhanced clinical outcome with the combination of PDL therapy and topical oxymetazoline for the treatment of erythematotelangiectatic rosacea patients. Lasers Surg. Med. © 2021 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals LLC.

Cell Populations Expressing Stemness-Associated Markers in Vascular Anomalies

Treatment of vascular anomalies (VAs) is mostly empirical and, in many instances unsatisfactory, as the pathogeneses of these heterogeneous conditions remain largely unknown. There is emerging evidence of the presence of cell populations expressing stemness-associated markers within many types of vascular tumors and vascular malformations. The presence of these populations in VAs is supported, in part, by the observed clinical effect of the mTOR inhibitor, sirolimus, that regulates differentiation of embryonic stem cells (ESCs). The discovery of the central role of the renin-angiotensin system (RAS) in regulating stem cells in infantile hemangioma (IH) provides a plausible explanation for its spontaneous and accelerated involution induced by β-blockers and ACE inhibitors. Recent work on targeting IH stem cells by inhibiting the transcription factor SOX18 using the stereoisomer R(+) propranolol, independent of β-adrenergic blockade, opens up exciting opportunities for novel treatment of IH without the β-adrenergic blockade-related side effects. Gene mutations have been identified in several VAs, involving mainly the PI3K/AKT/mTOR and/or the Ras/RAF/MEK/ERK pathways. Existing cancer therapies that target these pathways engenders the exciting possibility of repurposing these agents for challenging VAs, with early results demonstrating clinical efficacy. However, there are several shortcomings with this approach, including the treatment cost, side effects, emergence of treatment resistance and unknown long-term effects in young patients. The presence of populations expressing stemness-associated markers, including transcription factors involved in the generation of induced pluripotent stem cells (iPSCs), in different types of VAs, suggests the possible role of stem cell pathways in their pathogenesis. Components of the RAS are expressed by cell populations expressing stemness-associated markers in different types of VAs. The gene mutations affecting the PI3K/AKT/mTOR and/or the Ras/RAF/MEK/ERK pathways interact with different components of the RAS, which may influence cell populations expressing stemness-associated markers within VAs. The potential of targeting these populations by manipulating the RAS using repurposed, low-cost and commonly available oral medications, warrants further investigation. This review presents the accumulating evidence demonstrating the presence of stemness-associated markers in VAs, their expression of the RAS, and their interaction with gene mutations affecting the PI3K/AKT/mTOR and/or the Ras/RAF/MEK/ERK pathways, in the pathogenesis of VAs.

Evaluating the efficacy and safety of topical sirolimus 0.2% cream as adjuvant therapy with pulsed dye laser for the treatment of port wine stain: A randomized, double-blind, placebo-controlled trial

BACKGROUND

Port Wine Stain (PWS) is a congenital capillary malformation. Although multiple treatments are required, the gold standard treatment for PWS is Pulsed Dye Laser (PDL). Given its anti-angiogenic effects, sirolimus can be considered as an adjuvant to PDL in PWS.

AIM

To evaluate the efficacy and safety of topical sirolimus (Rapamycin) 0.2% cream as adjuvant therapy for PDL for PWS.

METHODS

In this randomized double-blind placebo-controlled trial, 15 patients with PWS were enrolled. Each lesion was divided into upper and lower parts, and each part was assigned randomly to receive PDL (4 sessions, 2 months apart) plus sirolimus vs PDL and placebo. The response was evaluated using colorimetry, investigator global assessment (IGA), and patient global assessment (PGA) every two months for eight continuous months.

RESULTS

According to the colorimetric analysis, medial and lateral sides of the treatment and placebo parts did not differ significantly (both P-value > .05). However, according to PGA and IGA, there was a significant difference in favor of sirolimus (P-values = .041 and .039, respectively). Itching and dryness (86.7%), contact dermatitis (20%) were the most common adverse effects in the sirolimus group, while none of them were observed in placebo.

CONCLUSION

Although the improvement was significant subjectively, topical sirolimus 0.2% as an adjuvant to PDL does not appear to improve PWS erythema using calorimetric assessment.

The Pathogenesis of Port Wine Stain and Sturge Weber Syndrome: Complex Interactions between Genetic Alterations and Aberrant MAPK and PI3K Activation

Port wine stain (PWS) is a congenital vascular malformation involving human skin. Approximately 15-20% of children a facial PWS involving the ophthalmic (V1) trigeminal dermatome are at risk for Sturge Weber syndrome (SWS), a neurocutaneous disorder with vascular malformations in the cerebral cortex on the same side of the facial PWS lesions. Recently, evidence has surfaced that advanced our understanding of the pathogenesis of PWS/SWS, including discoveries of somatic genetic mutations (GNAQ, PI3K), MAPK and PI3K aberrant activations, and molecular phenotypes of PWS endothelial cells. In this review, we summarize current knowledge on the etiology and pathology of PWS/SWS based on evidence that the activation of MAPK and/or PI3K contributes to the malformations, as well as potential futuristic treatment approaches targeting these aberrantly dysregulated signaling pathways. Current data support that: (1) PWS is a multifactorial malformation involving the entire physiological structure of human skin; (2) PWS should be pathoanatomically re-defined as "a malformation resulting from differentiation-impaired endothelial cells with a progressive dilatation of immature venule-like vasculatures"; (3) dysregulation of vascular MAPK and/or PI3K signaling during human embryonic development plays a part in the pathogenesis and progression of PWS/SWS; and (4) sporadic low frequency somatic mutations, such as GNAQ, PI3K, work as team players but not as a lone wolf, contributing to the development of vascular phenotypes. We also address many crucial questions yet to be answered in the future research investigations.

Site-specific pharmaco-laser therapy: A novel treatment modality for refractory port wine stains

Despite extensive efforts to optimize laser therapy, i.e., the current gold standard treatment, a majority of port wine stain (PWS) patients responds suboptimally to laser therapy. This paper describes the niceties of a novel PWS treatment modality termed site-specific pharmaco-laser therapy (SSPLT). In contrast to the classic approach of enhancing the extent of intravascular photocoagulation (the photothermal response), SSPLT focuses on optimization of post-irradiation thrombus formation (i.e., the hemodynamic response) by combining conventional laser therapy with the administration of thermosensitive drug delivery systems that encapsulate prothrombotic and antifibrinolytic drugs. The aim of SSPLT is to instill complete lumenal occlusion in target vessels, which has been linked to optimal PWS blanching.

RELEVANCE FOR PATIENTS

The current treatment options for PWS patients are limited in efficacy. Novel therapeutic modalities are needed to more effectively treat patients with recalcitrant PWSs. SSPLT is an experimental-stage treatment modality that could serve as an adjuvant to pulsed dye laser therapy for a selected group of patients whose PWS is ill-responsive to standard treatment. The expected clinical result of SSPLT is improved lesional blanching.

Membrane trafficking and exocytosis are upregulated in port wine stain blood vessels

INTRODUCTION

Port wine stain (PWS) is characterized as a progressive dilatation of immature venule-like vasculatures which result from differentiation-impaired endothelial cells. In this study, we aimed to identify the major biological pathways accounting for the pathogenesis of PWS.

METHODS

Sequential windowed acquisition of all theoretical fragment ion mass spectra (SWATH-MS) was used to identify differentially expressed proteins in PWS lesions, followed by confirmative studies with immunohistochemistry, immunoblot and transmission electron microscopy (TEM).

RESULTS

107 out of 299 identified proteins showed differential expressions in PWS lesions as compared to normal skin, mainly involving the functions of biosynthesis, membrane trafficking, cytoskeleton and cell adhesion/migration. The confirmative studies showed that expressions of membrane trafficking/exocytosis related proteins such as VAT1, IQGAP1, HSC70, clathrin, perlecan, spectrin α1 and GDIR1 were significantly increased in PWS blood vessels as compared to normal ones; while collagen subtypes 6A1 and 6A3 were decreased in PWS skin. Furthermore, TEM studies showed there is a significant upregulation of extracellular vesicle exocytosis from PWS blood vessels as compared to control.

CONCLUSIONS

The biological process of membrane trafficking and exocytosis is enhanced in PWS blood vessels. Our results imply that the extracellular vesicles released by lesional endothelial cells may act as potential intercellular signaling mediators to contribute to the pathogenesis of PWS.

Topical Adjuncts to Pulsed Dye Laser for Treatment of Port Wine Stains: Review of the Literature

BACKGROUND

Port wine stains (PWS) pose a therapeutic challenge. Pulsed dye laser (PDL) is the treatment of choice; however, treatment is often ineffective and recurrences are common.

OBJECTIVE

This article provides a review of topical therapies that have been investigated to improve efficacy of PDL for the treatment of PWS.

MATERIALS AND METHODS

A literature search was performed through PubMed, EMBASE, Web of Science, and CINAHL, using the search terms "port wine stain," "pulsed dye laser," and "topical."

RESULTS

Clinical trials have investigated the topical agents, timolol, imiquimod, and rapamycin (RPM) in combination with PDL for the treatment of PWS. Topical timolol with PDL failed to show improved efficacy compared with PDL alone. Two clinical trials using imiquimod and PDL showed enhanced blanching of PWS compared with controls. Rapamycin and PDL were more effective than controls for facial PWS, but not for nonfacial PWS.

CONCLUSION

Topical imiquimod and RPM have shown some efficacy in treating PWS with PDL, but to date there is no topical adjuvant to PDL that reliably improves results for PWS.

Activation of PKCα and PI3K Kinases in Hypertrophic and Nodular Port Wine Stain Lesions

Port wine stain (PWS) is a congenital, progressive vascular malformation. Many patients with PWS develop hypertrophy and discrete nodularity during their adult life, but the mechanism(s) remain incompletely understood. In this study, we attempted to investigate activation status of PKCα, PI3K, PDPK1 and PLC-γ and protein levels of PP2A and DAG to explore their potential roles in the formation of hypertrophic and nodular PWS lesions. We found phosphorylated levels of PKCα, PI3K, PDPK1, and PLC-γ and protein levels of PP2A and DAG showed moderate increases in the endothelial cells of hypertrophic PWS as compared to the adjacent normal skin. These increases extended throughout the entire stroma of blood vessels in PWS nodules. Many proliferating cells, such as fibroblasts, also showed strong activation of PKCα, PI3K, PDPK1 and PLC-γ and upregulations of PP2A and DAG in nodular PWS lesions. Our data showed that there is aberrant activation of PKCα, PI3K, PDPK1 and PLC-γ and upregulation of PP2A and DAG mainly in endothelial cells in hypertrophic PWS areas, but presenting in the entire vasculatures and surrounding fibroblasts in PWS nodules. Our data suggest that both PKCα and PI3K signaling pathways contribute to the development of hypertrophy and nodularity in adult PWS.

Coexistence of Eph receptor B1 and ephrin B2 in port-wine stain endothelial progenitor cells contributes to clinicopathological vasculature dilatation

BACKGROUND

Port-wine stain (PWS) is a vascular malformation characterized by progressive dilatation of postcapillary venules, but the molecular pathogenesis remains obscure.

OBJECTIVES

To illustrate that PWS endothelial cells (ECs) present a unique molecular phenotype that leads to pathoanatomical PWS vasculatures.

METHODS

Immunohistochemistry and transmission electron microscopy were used to characterize the ultrastructure and molecular phenotypes of PWS blood vessels. Primary culture of human dermal microvascular endothelial cells and in vitro tube formation assay were used for confirmative functional studies.

RESULTS

Multiple clinicopathological features of PWS blood vessels during the development and progression of the disease were shown. There were no normal arterioles and venules observed phenotypically and morphologically in PWS skin; arterioles and venules both showed differentiation impairments, resulting in a reduction of arteriole-like vasculatures and defects in capillary loop formation in PWS lesions. PWS ECs showed stemness properties with expression of endothelial progenitor cell markers CD133 and CD166 in non-nodular lesions. They also expressed dual venous/arterial identities, Eph receptor B1 (EphB1) and ephrin B2 (EfnB2). Co-expression of EphB1 and EfnB2 in normal human dermal microvascular ECs led to the formation of PWS-like vasculatures in vitro, for example larger-diameter and thick-walled capillaries.

CONCLUSIONS

PWS ECs are differentiation-impaired, late-stage endothelial progenitor cells with a specific phenotype of CD133⁺ /CD166⁺ /EphB1⁺ /EfnB2⁺ , which form immature venule-like pathoanatomical vasculatures. The disruption of normal EC-EC interactions by coexistence of EphB1 and EfnB2 contributes to progressive dilatation of PWS vasculatures.

Successful Treatment of Unilateral Klippel-Trenaunay Syndrome With Pulsed-Dye Laser in a 2-Week Old Infant

Introduction: Klippel-Trenaunay syndrome (KTS) is a rare congenital mesodermal abnormality characterized by varicose veins, cutaneous capillary malformation, as well as bone and soft tissue hypertrophy. Case Report: A 2-week-old female infant presented to our clinic because of vascular nevus and progressive enlargement of her right extremities and trunk since birth. The patient was treated with 595-nm pulsed-dye laser (PDL). Her port-wine stain (PWS) disappeared completely after third PDL session and the soft tissue hypertrophy stopped. The patient experienced neither recurrence nor any change in size after 7 years of follow up. Conclusion: PDL can treat KTS completely with no reccurence if it is used in "early stage" of disease.

Pediatric Dermatology

Skin changes are common in children. Common concerns are birthmarks (e.g., hemangiomas and port wine stains), atopic and contact dermatitis, acne, and alopecia areata. The authors review advances in common and not so common skin changes in pediatric patients.

Laser treatment of port-wine stains

Port-wine stains are a type of capillary malformation affecting 0.3% to 0.5% of the population. Port-wine stains present at birth as pink to erythematous patches on the skin and/or mucosa. Without treatment, the patches typically darken with age and may eventually develop nodular thickening or associated pyogenic granuloma. Laser and light treatments provide improvement through selective destruction of vasculature. A variety of vascular-selective lasers may be employed, with the pulsed dye laser being the most common and well studied. Early treatment produces more optimal results. Advances in imaging and laser treatment technologies demonstrate potential to further improve clinical outcomes.