Altered vimentin protein expression in human dermal microvascular endothelial cells after ultraviolet or intense pulsed light treatment

Consecutive dosing of UVB irradiation induces loss of ABCB5 expression and activation of EMT and fibrosis proteins in limbal epithelial cells similar to pterygium epithelium

Pterygium pathogenesis is often attributed to a population of altered limbal stem cells, which initiate corneal invasion and drive the hyperproliferation and fibrosis associated with the disease. These cells are thought to undergo epithelial to mesenchymal transition (EMT) and to contribute to subepithelial stromal fibrosis. In this study, the presence of the novel limbal stem cell marker ABCB5 in clusters of basal epithelial pterygium cells co-expressing with P63α and P40 is reported. ABCB5-positive pterygium cells also express EMT-associated fibrosis markers including vimentin and α-SMA while their β-catenin expression is reduced. By using a novel in vitro model of two-dose UV-induced EMT activation on limbal epithelial cells, we could observe the dysregulation of EMT-related proteins including an increase of vimentin and α-SMA as well as downregulation of β-catenin in epithelial cells correlating to downregulation of ABCB5. The sequential irradiation of limbal fibroblasts also induced an increase in vimentin and α-SMA. Taken together, these data demonstrate for the first time the expression of ABCB5 in pterygium stem cell activity and EMT-related events while the involvement of limbal stem cells in pterygium pathogenesis is exhibited via sequential irradiation of limbal epithelial cells. The later in vitro approach can be used to further study the involvement of limbal epithelium UV-induced EMT in pterygium pathogenesis and help identify novel treatments against pterygium growth and recurrence.

Will Repeated Ablative Er:YAG Laser Treatment Sessions Cause Facial Skin Sensitivity? Results of a 12-Month, Prospective, Randomized Split-Face Study

Whether multiple laser irradiations affect skin sensitivity is still elusive. We aimed to investigate if repeated ablative erbium:yttrium-aluminum-garnet (Er:YAG) laser therapy could cause or increase skin sensitivity in the treatment areas. Nineteen healthy females received three sessions of a randomized, split-face, Er:YAG laser treatment in a scanning ablative mode (MicroLaserPeel™), with a 6-mm spot size, 8-μm ablative depths, and 30% of pulse overlap first. The next round was conducted in the fractional mode (ProFractional™) at depths ranging from 100 to 150 μm, with one pass by at coverage of 11% in the coagulation mode. Objective biophysical parameters, including transepidermal water loss (TEWL), skin glossiness, epidermal and dermal thickness and density, sensory nerve current perception threshold (CPT), and local blood flow, were measured before and after treatment. Quantitative evaluation of the Er:YAG laser treatment's effect on skin sensitivity is presented. Seventeen volunteers completed a follow-up of 12 months. On days 1 and 3, skin TEWL and epidermal thickness increased, while glossiness decreased. On day 7, there was no significant difference in the skin barrier function between the treated and the control side. Similarly, there was no significant difference in CPT values or local microvascular blood flow between sides at any time point before or after treatment, except that the local microvascular blood flow on the treated side was higher on the first day post-treatment. Er:YAG laser treatment does not influence skin sensitivity in healthy subjects in a long-term follow-up.

Low-fluenced erbium:yttrium-aluminium-garnet laser treatment in combination with broadband light pretreatment for various pigmentation disorders in Asian patients

BACKGROUND

Low-fluenced 2940-nm erbium (Er):yttrium-aluminium-garnet (YAG) resurfacing elicits ablative photothermal tissue reactions confined to the uppermost parts of the epidermis.

OBJECTIVE

To demonstrate the efficacy and safety of low-fluenced ablative Er:YAG laser treatment in combination with broadband light (BBL) pretreatment for various pigmentation disorders.

METHODS

In total, 35 Korean patients with various pigmentation disorders were pretreated with BBL, and then, low-fluenced Er:YAG laser resurfacing was performed with a beam size of 4 mm and a fluence of 1.0-1.5 J/cm² .

RESULTS

An average of 1.1 ± 0.4 sessions of combined BBL and low-fluenced Er:YAG resurfacing treatment was delivered to the patients. Most post-Er:YAG scaling fell off spontaneously over 3-5 days, and most of the post-BBL crusting disappeared spontaneously over 5-7 days. At 2 months after final treatment, the mean global aesthetic improvement scale score for the clinical improvement of pigmentation lesions was estimated as 2.5 ± 0.8, and that for the improvement of overall skin tone, texture, and wrinkles was 2.8 ± 1.0.

CONCLUSION

Our data demonstrated that post-BBL, low-fluenced Er:YAG laser resurfacing can be used to effectively treat various pigmentation disorders in Asian patients. Further improvements in overall skin tone, texture, and wrinkles were also achieved without major side effects.

Broadband light treatment using static operation and constant motion techniques for skin tightening in Asian patients

BACKGROUND

Broadband light (BBL) devices irradiate photons of different wavelength to induce photothermal reactions on various aging-related chromophores.

OBJECTIVES

To evaluate three BBL treatment settings for skin tightening in Asian patients.

METHODS

A total of 27 patients underwent three sessions of BBL treatment via (1) an 800-nm cutoff filter using a static operation technique and a 695-nm cutoff filter using a constant motion technique (group 1, N = 9), (2) an 800-nm cutoff filter using a constant motion technique (group 2, N = 9), and (3) a 590-nm cutoff filter using a constant motion technique (group 3, N = 9).

RESULTS

The patients in group 1 presented marked clinical improvements in zygomatic wrinkles, nasolabial folds, and marionette lines, with a median overall global aesthetic improvement scale (GAIS) score of 3. Meanwhile, patients in group 2 exhibited noticeable improvements in zygomatic wrinkles, nasolabial folds, perioral expression wrinkles at the cheek, and marionette lines, with a median GAIS score of 3. Patients in group 3 experienced improvement in skin tone and texture, zygomatic wrinkles, nasolabial folds, and marionette lines, with a median GAIS score of 2.

CONCLUSIONS

Our data demonstrated that BBL treatment for nonablative, noninvasive skin tightening elicits satisfactory clinical outcomes.