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Lasers in Surgery and Medicine Apr 2024A threshold fluence for melanosome disruption has the potential to provide a robust numerical indicator for establishing clinical endpoints for pigmented lesion...
Wavelength-dependent threshold fluences for melanosome disruption to evaluate the treatment of pigmented lesions with 532-, 730-, 755-, 785-, and 1064-nm picosecond lasers.
BACKGROUND AND OBJECTIVES
A threshold fluence for melanosome disruption has the potential to provide a robust numerical indicator for establishing clinical endpoints for pigmented lesion treatment using a picosecond laser. Although the thresholds for a 755-nm picosecond laser were previously reported, the wavelength dependence has not been investigated. In this study, wavelength-dependent threshold fluences for melanosome disruption were determined. Using a mathematical model based on the thresholds, irradiation parameters for 532-, 730-, 755-, 785-, and 1064-nm picosecond laser treatments were evaluated quantitatively.
STUDY DESIGN/MATERIALS AND METHODS
A suspension of melanosomes extracted from porcine eyes was irradiated using picosecond lasers with varying fluence. The mean particle size of the irradiated melanosomes was measured by dynamic light scattering, and their disruption was observed by scanning electron microscopy to determine the disruption thresholds. A mathematical model was developed, combined with the threshold obtained and Monte Carlo light transport to calculate irradiation parameters required to disrupt melanosomes within the skin tissue.
RESULTS
The threshold fluences were determined to be 0.95, 2.25, 2.75, and 6.50 J/cm² for 532-, 730-, 785-, and 1064-nm picosecond lasers, respectively. The numerical results quantitatively revealed the relationship between irradiation wavelength, incident fluence, and spot size required to disrupt melanosomes distributed at different depths in the skin tissue. The calculated irradiation parameters were consistent with clinical parameters that showed high efficacy with a low incidence of complications.
CONCLUSION
The wavelength-dependent thresholds for melanosome disruption were determined. The results of the evaluation of irradiation parameters from the threshold-based analysis provided numerical indicators for setting the clinical endpoints for 532-, 730-, 755-, 785-, and 1064-nm picosecond lasers.
Topics: Animals; Swine; Melanosomes; Lasers; Skin; Lasers, Solid-State; Treatment Outcome
PubMed: 38436524
DOI: 10.1002/lsm.23773 -
Cell Communication and Signaling : CCS Feb 2024Coenzyme Q (CoQ), a novel quinone derivative of Antrodia camphorata, has been utilized as a therapeutic agent (including antioxidant, anti-inflammatory, antiangiogenic,...
The in vitro and in vivo depigmentation activity of coenzyme Q, a major quinone derivative from Antrodia camphorata, through autophagy induction in human melanocytes and keratinocytes.
BACKGROUND
Coenzyme Q (CoQ), a novel quinone derivative of Antrodia camphorata, has been utilized as a therapeutic agent (including antioxidant, anti-inflammatory, antiangiogenic, antiatherosclerotic, and anticancer agents); however, its depigmenting efficiency has yet to be studied.
METHODS
We resolved the depigmenting efficiency of CoQ through autophagy induction in melanoma (B16F10) and melanin-feeding keratinocyte (HaCaT) cells and in vivo Zebrafish model. Then, MPLC/HPLC analysis, MTT assay, Western blotting, immunofluorescence staining, LC3 transfection, melanin formation, GFP-LC3 puncta, AVO formation, tyrosinase activity, and TEM were used.
RESULTS
CoQ-induced autophagy in B16F10 cells was shown by enhanced LC3-II accumulation, ATG7 expression, autophagosome GFP-LC3 puncta, and AVOs formation, and ATG4B downregulation, and Beclin-1/Bcl-2 dysregulation. In α-MSH-stimulated B16F10 cells, CoQ induced antimelanogenesis by suppressing CREB-MITF pathway, tyrosinase expression/activity, and melanin formation via autophagy. TEM data disclosed that CoQ increased melanosome-engulfing autophagosomes and autolysosomes in α-MSH-stimulated B16F10 cells. CoQ-inhibited melanogenesis in α-MSH-stimulated B16F10 cells was reversed by pretreatment with the autophagy inhibitor 3-MA or silencing of LC3. Additionally, CoQ-induced autophagy in HaCaT cells was revealed by enhanced LC3-II accumulation, autophagosome GFP-LC3 puncta and AVO formation, ATG4B downregulation, ATG5/ATG7 expression, and Beclin-1/Bcl-2 dysregulation. In melanin-feeding HaCaT cells, CoQ induced melanin degradation by suppressing melanosome gp100 and melanin formation via autophagy. TEM confirmed that CoQ increased melanosome-engulfing autophagosomes and autolysosomes in melanin-feeding HaCaT cells. Treatment with 3-MA reversed CoQ-mediated melanin degradation in melanin-feeding HaCaT cells. In vivo study showed that CoQ suppressed endogenous body pigmentation by antimelanogenesis and melanin degradation through autophagy induction in a zebrafish model.
CONCLUSIONS
Our results showed that CoQ exerted antimelanogenesis and melanin degradation by inducing autophagy. CoQ could be used in skin-whitening formulations as a topical cosmetic application.
Topics: Animals; Humans; Ubiquinone; Melanins; Zebrafish; Monophenol Monooxygenase; alpha-MSH; Beclin-1; Melanocytes; Keratinocytes; Autophagy; Proto-Oncogene Proteins c-bcl-2; Cell Line, Tumor; Benzoquinones; Polyporales
PubMed: 38408981
DOI: 10.1186/s12964-024-01537-6 -
Membranes Feb 2024Lysosomal degradation of tyrosinase, a pivotal enzyme in melanin synthesis, negatively impacts melanogenesis in melanocytes. Nevertheless, the precise molecular...
Lysosomal degradation of tyrosinase, a pivotal enzyme in melanin synthesis, negatively impacts melanogenesis in melanocytes. Nevertheless, the precise molecular mechanisms by which lysosomes target tyrosinase have remained elusive. Here, we identify RING (Really Interesting New Gene) finger protein 152 (RNF152) as a membrane-associated ubiquitin ligase specifically targeting tyrosinase for the first time, utilizing AlphaScreen technology. We observed that modulating RNF152 levels in B16 cells, either via overexpression or siRNA knockdown, resulted in decreased or increased levels of both tyrosinase and melanin, respectively. Notably, RNF152 and tyrosinase co-localized at the trans-Golgi network (TGN). However, upon treatment with lysosomal inhibitors, both proteins appeared in the lysosomes, indicating that tyrosinase undergoes RNF152-mediated lysosomal degradation. Through ubiquitination assays, we found the indispensable roles of both the RING and transmembrane (TM) domains of RNF152 in facilitating tyrosinase ubiquitination. In summary, our findings underscore RNF152 as a tyrosinase-specific ubiquitin ligase essential for regulating melanogenesis in melanocytes.
PubMed: 38392670
DOI: 10.3390/membranes14020043 -
Pediatric Research Feb 2024Concerns have been raised about the effect of skin color on the accuracy of transcutaneous bilirubin (TcB) measurements, a widely used method for hyperbilirubinemia...
OBJECTIVE
Concerns have been raised about the effect of skin color on the accuracy of transcutaneous bilirubin (TcB) measurements, a widely used method for hyperbilirubinemia diagnosis in newborns. Literature is inconclusive, with both reported under- and overestimations of the TcB with increasing skin pigmentation. Therefore, the influence of skin color on TcB measurements was systematically evaluated in a controlled, in vitro setting.
METHODS
A bilirubin meter (JM-105) was evaluated on layered phantoms that mimic neonatal skin with varying dermal bilirubin concentrations (0-250 µmol/L) and varying epidermal melanosome volume fractions (0-40%; light-dark skin color).
RESULTS
TcB measurements were influenced by skin pigmentation. Larger mimicked melanosome volume fractions and higher bilirubin levels led to larger underestimations of the measured TcB, compared to an unpigmented epidermis. In the in vitro setting of this study, these underestimations amounted to 26-132 µmol/L at a TcB level of 250 µmol/L.
CONCLUSION
This in vitro study provides insight into the effect of skin color on TcB measurements: the TcB is underestimated as skin pigmentation increases and this effect becomes more pronounced at higher bilirubin levels. Our results highlight the need for improved TcB meter design and cautious interpretation of TcB readings on newborns with dark skin.
IMPACT
Key message: Skin color influences transcutaneous bilirubin measurements: the darker the skin, the larger the underestimation. What this study adds to existing literature: Existing literature is inconclusive regarding the influence of skin color on transcutaneous bilirubin measurements. This study systematically evaluates and clarifies the influence of skin color on transcutaneous bilirubin measurements in a controlled, in vitro setting.
IMPACT
This study aids to better interpret the measured TcB level in patients with varying skin colors, and is particularly important when using TcB meters on patients with dark skin colors.
PubMed: 38368497
DOI: 10.1038/s41390-024-03081-y -
Optics Letters Feb 2024Optical resolution photoacoustic microscopy (OR-PAM) is a hybrid imaging method for visualizing organelles due to the high spatial resolution and abundant optical...
Optical resolution photoacoustic microscopy (OR-PAM) is a hybrid imaging method for visualizing organelles due to the high spatial resolution and abundant optical contrast. Usually, OR-PAM employs high numerical aperture (NA) objectives and high-frequency ultrasonic detectors to resolve three-dimensional (3D) microstructures of cells. Expansion microscopy (ExM) provides a nanoscale resolution by isotropically enlarging cells instead of utilizing ultrahigh NA objectives. In this Letter, we report the development of photoacoustic expansion microscopy (PA-ExM) that combines the advantages of OR-PAM and ExM for 3D organelle imaging using near-infrared light. We evaluate the performance of PA-ExM using label-free melanoma cells, where the image quality of melanosome distributions in expanded cells using a 40× objective is comparable to that of unexpanded cells using an oil-immersed 100× objective. The results suggest that PA-ExM possesses the great potential to study organelles.
Topics: Microscopy; Melanosomes; Photoacoustic Techniques; Spectrum Analysis; Multimodal Imaging
PubMed: 38359185
DOI: 10.1364/OL.509831 -
Journal of Pharmaceutical Analysis Jan 2024Epimedin B (EB) is one of the main flavonoid ingredients present in Maxim., a traditional herb widely used in China. Our previous study showed that EB was a stronger...
Epimedin B (EB) is one of the main flavonoid ingredients present in Maxim., a traditional herb widely used in China. Our previous study showed that EB was a stronger inducer of melanogenesis and an activator of tyrosinase (TYR). However, the role of EB in melanogenesis and the mechanism underlying the regulation remain unclear. Herein, as an extension to our previous investigation, we provide comprehensive evidence of EB-induced pigmentation and and elucidate the melanogenesis mechanism by assessing its effects on the TYR family of proteins (TYRs) in terms of expression, activity, and stability. The results showed that EB increased TYRs expression through microphthalmia-associated transcription factor-mediated p-Akt (referred to as protein kinase B (PKB))/glycogen synthase kinase 3β (GSK3β)/β-catenin, p-p70 S6 kinase cascades, and protein 38 (p38)/mitogen-activated protein (MAP) kinase (MAPK) and extracellular regulated protein kinases (ERK)/MAPK pathways, after which EB increased the number of melanosomes and promoted their maturation for melanogenesis in melanoma cells and human primary melanocytes/skin tissues. Furthermore, EB exerted repigmentation by stimulating TYR activity in hydroquinone- and -phenylthiourea-induced TYR inhibitive models, including melanoma cells, zebrafish, and mice. Finally, EB ameliorated monobenzone-induced depigmentation and through the enhancement of TYRs stability by inhibiting TYR misfolding, TYR-related protein 1 formation, and retention in the endoplasmic reticulum and then by downregulating the ubiquitination and proteolysis processes. These data conclude that EB can target TYRs and alter their expression, activity, and stability, thus stimulating their pigmentation function, which might provide a novel rational strategy for hypopigmentation treatment in the pharmaceutical and cosmetic industries.
PubMed: 38352950
DOI: 10.1016/j.jpha.2023.09.006 -
Nature Communications Feb 2024A major limitation to developing chimeric antigen receptor (CAR)-T cell therapies for solid tumors is identifying surface proteins highly expressed in tumors but not in...
A major limitation to developing chimeric antigen receptor (CAR)-T cell therapies for solid tumors is identifying surface proteins highly expressed in tumors but not in normal tissues. Here, we identify Tyrosinase Related Protein 1 (TYRP1) as a CAR-T cell therapy target to treat patients with cutaneous and rare melanoma subtypes unresponsive to immune checkpoint blockade. TYRP1 is primarily located intracellularly in the melanosomes, with a small fraction being trafficked to the cell surface via vesicular transport. We develop a highly sensitive CAR-T cell therapy that detects surface TYRP1 in tumor cells with high TYRP1 overexpression and presents antitumor activity in vitro and in vivo in murine and patient-derived cutaneous, acral and uveal melanoma models. Furthermore, no systemic or off-tumor severe toxicities are observed in an immunocompetent murine model. The efficacy and safety profile of the TYRP1 CAR-T cell therapy supports the ongoing preparation of a phase I clinical trial.
Topics: Humans; Mice; Animals; Melanoma; Receptors, Chimeric Antigen; Immunotherapy, Adoptive; Uveal Neoplasms; Cell- and Tissue-Based Therapy; Membrane Glycoproteins; Oxidoreductases
PubMed: 38336975
DOI: 10.1038/s41467-024-45221-2 -
International Journal of Cosmetic... Feb 2024Tyrosinase inhibitors suppress melanogenesis in melanocytes. During a screening for tyrosinase inhibitors, however, we noticed some discrepancies in inhibitory...
OBJECTIVE
Tyrosinase inhibitors suppress melanogenesis in melanocytes. During a screening for tyrosinase inhibitors, however, we noticed some discrepancies in inhibitory efficacies between melanocytes and in vitro assays. The compound (S)-N-{3-[4-(dimethylamino)phenyl]propyl}-N-methyl-indan-1-amine (GIF-2115) exerts antioxidative stress activity upon accumulation in late endosomes and lysosomes. GIF-2115 was also identified as a potent antimelanogenic reagent in B16F10 mouse melanoma cells. GIF-2115 inhibited the activity of mushroom tyrosinase and the lysates of B16F10 cells. However, structure-activity relationship studies indicated that GIF-2238, which lacks the benzene ring in the aminoindan structure of GIF-2115, inhibited tyrosinase activity in vitro but did not inhibit melanogenesis in B16F10 cells. The aim of the present study is to show the importance of the intracellular distribution of tyrosinase inhibitors in exerting their antimelanogenic activity in melanocytes.
METHODS
The intracellular distribution of compounds was monitored by linking with the fluorescent group of 7-nitro-2,1,3-benzoxadiazole (NBD). To mislocalize GIF-2115 to mitochondria, the mitochondria-preferring fluoroprobe ATTO565 was used.
RESULTS
We reconfirmed the localization of GIF-2250 (GIF-2115-NBD) not only to matured but also to early-stage melanosomes. Although GIF-2286 (GIF-2238-NBD) maintained tyrosinase inhibitory activity, it did not show specific intracellular localization. Moreover, when GIF-2115 was linked with ATTO565, the resultant compound GIF-2265 did not inhibit melanogenesis in B16F10 cells, despite its strong tyrosinase inhibitory activity.
CONCLUSION
These results suggest that melanosomal localization is essential for the antimelanogenic activity of GIF-2115, and GIF-2115 derivatives may be new guides for drugs to endosomes and lysosomes as well as melanosomes.
PubMed: 38327040
DOI: 10.1111/ics.12949 -
Clinical, Cosmetic and Investigational... 2024For dermatologists, diversities of human races result in an opportunity to encounter patients with various skin types. Cosmetic procedures have gained more popularity... (Review)
Review
For dermatologists, diversities of human races result in an opportunity to encounter patients with various skin types. Cosmetic procedures have gained more popularity and become more accessible over the past decades. Thus, the selection of appropriate treatment protocol for each patient becomes inevitable. This review will focus on basic knowledge and key points in performing safe cosmetic-related procedures in patients with dark-complexioned skin. In terms of structure and function of the skin, people of color have equal epidermal thickness, corneocyte size and melanocyte number. However, they have more stratum corneum compaction, melanosome dispersion and melanocyte activity than fair skin individuals. Data regarding drug penetration and cutaneous irritation showed conflicting results. Superficial chemical peels and microdermabrasion can be done safely in dark-skinned patients. Medium-depth peel should be used with extreme caution. While deep-depth peel should be avoided at all times due to pigmentary and textural complications. Prolonged treatment interval, use of priming agents and sun protection are recommended. Injectable materials including botulinum toxin and soft tissue augmentation by hyaluronic acid filler can be done harmlessly in dark-skinned patients. Lasers and energy-based devices should be done with caution. Higher melanin dispersion and melanocyte activity acts as competitive chromophore. Pigmentary or textural changes can occur after aggressive treatment protocol. High energy setting, pulse stacking, short wavelength lasers and short treatment interval should be avoided in dark-skinned patients.
PubMed: 38321987
DOI: 10.2147/CCID.S450081 -
Biomolecules & Therapeutics Mar 2024Methyl anthranilate (MA) is a botanical fragrance used in food flavoring with unexplored potential in anti-pigment cosmetics. MA dose-dependently reduced melanin content...
Methyl anthranilate (MA) is a botanical fragrance used in food flavoring with unexplored potential in anti-pigment cosmetics. MA dose-dependently reduced melanin content without affecting cell viability, inhibited dendrite elongation and melanosome transfer in the co-culture system of human melanoma cells (MNT-1) and human keratinocyte cell line (HaCaT), and downregulated melanogenic genes, including tyrosinase, tyrosinase-related protein 1 and 2 (TRP-1, TRP-2). Additionally, MA decreased cyclic adenosine monophosphate (cAMP) production and exhibited a significant anti-pigmentary effect in Melanoderm™. These results suggest that MA is a promising anti-pigmentary agent for replacing or complementing existing anti-pigmentary cosmetics.
PubMed: 38296651
DOI: 10.4062/biomolther.2023.103