A randomized, controlled, split-face, double-blind comparison of a multimodality pigment-correcting serum containing lotus sprout extract versus hydroquinone for moderate to severe facial hyperpigmentation, including melasma, in a diverse population.

Background: Hyperpigmentation results in uneven skin tone, with darker skin types disproportionately affected. Objective: Assess efficacy and safety of a novel, hydroquinone (HQ)-free, multimodal pigment-correcting serum (Advanced Brightening Treatment [ABT]) versus 4% HQ in moderate to severe hyperpigmentation, including melasma. Methods: In this split-face study, ABT and 4% HQ were applied topically on randomly assigned facial sides twice daily for 12 weeks. Hyperpigmentation, skin tone evenness, modified Melasma Area and Severity Index (mMASI), Melasma Quality of Life Questionnaire (MelasQoL), self-assessment questionnaires, and tolerability were assessed. Results: Subjects (n = 113; melasma subgroup, n = 44) were Asian (22%), Black/African American (27%), Hispanic (22%), and White/Caucasian (28%). ABT achieved comparable results to 4% HQ. ABT was well tolerated and resulted in improvement versus baseline at all visits in mean overall hyperpigmentation (-11.7% at week 12; P ≤ .001), skin tone evenness (-8.8%, P ≤ .005), and, in the melasma subgroup, mMASI (-50.6%; P ≤ .011) and MelasQoL scores (33.0 vs 46.6 for week 12 vs baseline, respectively; P ≤ .011), with similar results across racial subgroups. ABT was preferred over 4% HQ, with high satisfaction rate (≥89%). Limitations: Quality of life improvements per treatment were not evaluated separately. Conclusion: Efficacy and safety of ABT is comparable to 4% HQ in individuals with facial hyperpigmentation, including melasma, across multiple racial/ethnic backgrounds.

12-Week, Single-Center Study of a Targeted Pigment-Correcting Dark Spot Treatment for Post-Inflammatory Hyperpigmentation and Solar Lentigines.

Purpose: Post-inflammatory hyperpigmentation (PIH) and solar lentigines are dark spots of skin from excessive melanin production due to injury or UV exposure. This 12-week single-center study assessed the efficacy and tolerability of a novel targeted pigment-correcting spot treatment gel suspension cream (Dark Spot Treatment) for improving mild-to-moderate PIH or solar lentigines. Patients and Methods: Female participants (N = 41) aged 25-65 with mild-to-moderate facial dark spots applied Dark Spot Treatment daily for 12 weeks. Investigators assessed overall hyperpigmentation, skin tone evenness, and dark spot intensity, contrast, and size at Weeks 2, 4, 8, and 12. Participant self-assessments occurred at Weeks 1, 2, 4, 8, and 12. Tolerability was assessed by clinical grading and participant reporting. Results: Dark Spot Treatment improved overall hyperpigmentation, skin tone evenness, and dark spot intensity and contrast at Weeks 2 through 12, and dark spot size at Weeks 4 through 12 (all p < 0.001 compared to baseline). Participant self-assessments showed high overall satisfaction. Dark Spot Treatment was well tolerated. Conclusion: The novel pigment-correcting Dark Spot Treatment significantly improved the appearance of PIH and solar lentigines, had high participant satisfaction, and was well tolerated.

Restoration of Aging Body Skin: Evidence-Based Development of a Topical Formulation for Improving Body Skin Quality.

BACKGROUND: Age-related changes in body skin are emerging as important therapeutic targets. A novel topical firming and toning body lotion (FTB) has been developed to target multiple pathways involved in body skin rejuvenation. METHODS: FTB was evaluated in a randomized, double-blind, vehicle-controlled, 12-week study in women (N=54) with mild to moderate lack of firmness on the upper arms and mild to moderate cellulite on the thighs. Investigator clinical assessments, instrumentation evaluations, and patient questionnaires were performed. Histological assessment of ex vivo human skin treated with FTB and gene expression analysis in 3-dimensional human skin models following application of FTB or product comparators were conducted. RESULTS: At week 12, FTB treatment significantly improved (vs baseline) firmness, sagging, smoothness, texture, cellulite, and crepiness on investigator-, instrument-, and photographically assessed outcomes. Participants reported significant improvements in self-perceived efficacy and overall satisfaction with the appearance of their skin following FTB treatment vs vehicle control. Adverse events were mild or moderate in severity. FTB supported new collagen and elastic fiber formation in ex vivo skin. FTB increased skin rejuvenation–associated gene expression vs comparator products. CONCLUSIONS: FTB provided significant improvements in the upper arms and thighs compared with baseline and vehicle control across multiple investigator and instrumentation evaluations. Most participants reported greater efficacy and treatment satisfaction with FTB vs vehicle. FTB treatment stimulated dermal extracellular matrix renewal and induced expression of genes involved in skin rejuvenation pathways. This study provides clinical and preclinical evidence supporting the use of FTB to improve body skin quality. Citation: Makino ET, Jiang LI, Acevedo SF, et al. Restoration of aging body skin: evidence-based development of a topical formulation for improving body skin quality. J Drugs Dermatol. 2023;22(9):887-897. doi:10.36849/JDD.7292.

Targeting Multiple Hallmarks of Skin Aging: Preclinical and Clinical Efficacy of a Novel Growth Factor-Based Skin Care Serum.

INTRODUCTION: The aging process involves numerous biological mechanisms that have been characterized and proposed as the "hallmarks of aging." Targeting the processes and pathways related to these hallmarks of aging that cause and promote skin aging could provide anti-aging benefits. A novel topical growth factor-based skin care serum (A+) was developed using human fibroblast conditioned media. This study aimed to assess the effects of A+ on four hallmarks of aging and its clinical efficacy in skin rejuvenation in subjects with moderate to severe overall facial photodamage. METHODS: Preclinical studies included immunohistochemistry in human ex vivo skin, and gene expression analysis in human 3D skin models. A 24-week, vehicle placebo-controlled study, including FaceQ patient-reported outcomes and skin biopsy analysis, was performed to assess clinical efficacy and tolerability. RESULTS: Treatment with A+ resulted in reduced expression of cell senescence biomarker H2A.J and upregulation of genes associated with proteasome, autophagy, stemness, and intercellular communication. Clinical assessments showed A+ provided significantly greater reductions in sagging, coarse lines/wrinkles, fine lines/wrinkles, overall photodamage, and overall hyperpigmentation compared with placebo. Subjects felt they appeared younger-looking, reporting a median decrease in self-perceived age of 6 years after 12 weeks of use. Decreased levels of H2A.J and increased expression of key dermal extracellular matrix and epidermal barrier components, including collagen and elastin, were observed in skin biopsy samples. CONCLUSION: The present study shows for the first time the potential effects of a topical growth factor-based cosmeceutical on cellular processes related to four hallmarks of aging (cellular senescence, loss of proteostasis, stem cell exhaustion, and altered intercellular communication) to help delay the aging process and restore aged skin. A+ targets the biological mechanisms underlying the aging process itself and stimulates skin regeneration, resulting in rapid and significant clinical improvements.

Improving Body Skin Quality: Evidence-Based Development of Topical Treatment and Survey of Current Options.

The growing interest in improving the quality of body (as distinct from facial) skin may be in part attributable to the expanding use of noninvasive body contouring procedures. In this review, we describe a new framework characterizing the factors that define skin quality (including visual, textural, and biomechanical attributes) that provides a foundation for improved assessment of skin quality and its response to treatment. We then highlight critical biological pathways responsible for body skin restoration and maintenance that have been identified during the development of restorative topical products. Each of these pathways, including extracellular matrix support, suppression of lipogenesis, and enhancement of cellular/macromolecular recycling and clearance, lymphatic drainage, and lipolysis, is a potential target of 1 or more bioactive substances. A survey of available topical products marketed for skin quality improvement suggests that none target more than 2 of these pathways (including extracellular matrix support, lipolysis, and autophagy, a component of cellular recycling), leaving abundant opportunity for development of new topical formulations that target all or most of the critical pathways. Such formulations may provide improved outcomes when used as standalone products for general skin quality improvement and rejuvenation, in addition to their potential for post-procedure use, and also for pre-procedure skin conditioning. J Drugs Dermatol. 2022;21(6):653-658. doi:10.36849/JDD.6811.

Rationale and Preclinical Evaluation of a Multimodal Topical Body Skincare Product for Toning and Tightening.

A novel tightening and toning cream (TTC) was designed to improve body skin quality at multiple levels by engaging several key pathways that contribute to skin function, strength, and integrity. Evaluation of gene expression in both human in vitro 3D skin and ex vivo skin treated with TTC demonstrated changes reflecting improved extracellular matrix and dermal integrity, lymphatic drainage, mitigation of inflammation, cellular clearance and recycling, and adipocyte metabolism. This study provides the rationale and preclinical support for the use of TTC as a standalone agent to improve body skin quality or in combination with body contouring procedures. J Drugs Dermatol. 2021;20(10):1041-1044. doi:10.36849/JDD.6401.

Clinical Efficacy of a Novel Two-Part Skincare System on Pollution-Induced Skin Damage.

INTRODUCTION: Air pollution continues to be a global health concern and recent studies have shown that air pollutants can cause skin damage and skin aging through several pathways that induce oxidative stress, inflammation, apoptosis, and skin barrier dysfunction. Preventive measures need to be considered to retain optimal skin health, and topical skincare products may be able to alleviate the negative effects of air pollution on skin. A randomized, double-blind, placebo-controlled clinical usage study was conducted to assess the efficacy and tolerability of a novel two-part skincare system (LVS) that was developed to provide protection against environmental skin aggressors including air pollution. After 8 weeks of use in subjects exposed to extremely high levels of pollution, LVS provided significant improvements compared to placebo in all clinical efficacy parameters including crow's feet wrinkles, overall skin damage, skin tone evenness, tactile roughness, and visible redness. Subject self-assessment questionnaires showed that the treatment product was highly rated in self-perceived efficacy. Decreased SQOOH and MDA content in skin swab samples suggest that LVS helped to reduce oxidative stress in patients' skin. Histological analyses of biopsy samples using biomarkers related to skin structure, damage and function (collagen IV, MMP1, CPD, and CD1a) further support the clinical benefits of LVS. Altogether, the presented study is among the first to show that topical skincare products can help to reduce pollution-induced skin damage and improve skin quality, especially when specifically formulated with active ingredients that combat the harmful effects of air pollutants. J Drugs Dermatol. 2018;17(9):975-981.

Addressing Male Facial Skin Concerns: Clinical Efficacy of a Topical Skincare Treatment Product for Men.

The growing male skincare market reflects the increased interest of men in addressing facial aging concerns and maintaining a healthy youthful appearance. Because of differences in skin structure and aging as well as in lifestyle and behavior, male facial skin presents unique challenges that may result in different priorities or treatment strategies compared to female skin. A clinical study was conducted to assess clinical efficacy and tolerability of a topical skincare treatment product that was developed to address several male facial skin concerns related to skin quality, skin aging, and shaving. The treatment product provided significant improvements in all clinical efficacy parameters including overall photodamage, tactile roughness, fine line/wrinkles, and coarse lines/wrinkles. Furthermore, significant improvements in erythema as well as dryness/scaling were observed. Subject self-assessment questionnaires showed that the treatment product was highly rated in both self-perceived efficacy as well as product attributes. Use of skincare treatment products that tackle specific male facial skin concerns could further optimize skin quality and support healthy and youthful looking skin in men.

J Drugs Dermatol. 2018;17(3):301-306.

Upregulation of Extracellular Matrix Genes Corroborates Clinical Efcacy of Human Fibroblast-Derived Growth Factors in Skin Rejuvenation.

Skin care products may use various active ingredients to support skin rejuvenation including growth factors and other molecules that help to regenerate extracellular matrix (ECM) and promote skin repair. The biological effect of skin care products with a strong anti-aging claim was assessed in gene expression analyses using an in vitro human skin model. Application of products containing human fibroblast-derived growth factors resulted in signifcant upregulation of genes encoding ECM components including collagens and elastin. Human fibroblasts cultured under hypoxic conditions show increased gene expression of stem cell markers, and their conditioned media could possibly further support skin rejuvenation. Furthermore, a double-blind, randomized, placebo-controlled study was con-ducted in subjects with moderate to severe facial photodamage to assess the cosmetic clinical efficacy of a product containing human fibroblast-derived growth factors. The test product group demonstrated significantly greater reductions in the appearance of fne lines/wrinkles, coarse line/wrinkles, and overall photodamage, compared to the placebo group. Altogether, the results suggest that human fibroblast-derived growth factors support skin rejuvenation by stimulating dermal fibroblasts to generate ECM.

Cathepsin B as a potential cystatin M/E target in the mouse hair follicle.

Deficiency of the cysteine protease inhibitor cystatin M/E (Cst6) in mice leads to disturbed epidermal cornification, impaired barrier function, and neonatal lethality. We report the rescue of the lethal skin phenotype of ichq (Cst6-deficient; Cst6-/-) mice by transgenic, epidermis-specific, reexpression of Cst6 under control of the human involucrin (INV) promoter. Rescued Tg(INV-Cst6)Cst6ichq/ichq mice survive the neonatal phase, but display severe eye pathology and alopecia after 4 mo. We observed keratitis and squamous metaplasia of the corneal epithelium, comparable to Cst6-/-Ctsl+/- mice, as we have reported in other studies. We found the INV promoter to be active in the hair follicle infundibulum; however, we did not observe Cst6 protein expression in the lower regions of the hair follicle in Tg(INV-Cst6)Cst6ichq/ichq mice. This result suggests that unrestricted activity of proteases is involved in disturbance of hair follicle biology, eventually leading to baldness. Using quenched activity-based probes, we identified mouse cathepsin B (CtsB), which is expressed in the lower regions of the hair follicle, as an additional target of mouse Cst6. These data suggest that Cst6 is necessary to control CtsB activity in hair follicle morphogenesis and highlight Cst6-controlled proteolytic pathways as targets for preventing hair loss.-Oortveld, M. A. W., van Vlijmen-Willems, I. M. J. J., Kersten, F. F. J., Cheng, T., Verdoes, M., van Erp, P. E. J., Verbeek, S., Reinheckel, T., Hendriks, W. J. A. J., Schalkwijk, J., Zeeuwen, P. L. J. M. Cathepsin B as a potential cystatin M/E target in the mouse hair follicle.

Loss of Oca2 disrupts the unfolded protein response and increases resistance to endoplasmic reticulum stress in melanocytes.

Accumulation of proteins in the endoplasmic reticulum (ER) typically induces stress and initiates the unfolded protein response (UPR) to facilitate recovery. If homeostasis is not restored, apoptosis is induced. However, adaptation to chronic UPR activation can increase resistance to subsequent acute ER stress. We therefore investigated adaptive mechanisms in Oculocutaneous albinism type 2 (Oca2)-null melanocytes where UPR signaling is arrested despite continued tyrosinase accumulation leading to resistance to the chemical ER stressor thapsigargin. Although thapsigargin triggers UPR activation, instead of Perk-mediated phosphorylation of eIF2α, in Oca2-null melanocytes, eIF2α was rapidly dephosphorylated upon treatment. Dephosphorylation was mediated by the Gadd34-PP1α phosphatase complex. Gadd34-complex inhibition blocked eIF2α dephosphorylation and significantly increased Oca2-null melanocyte sensitivity to thapsigargin. Thus, Oca2-null melanocytes adapt to acute ER stress by disruption of pro-apoptotic Perk signaling, which promotes cell survival. This is the first study to demonstrate rapid eIF2α dephosphorylation as an adaptive mechanism to ER stress.

The cystatin M/E-cathepsin L balance is essential for tissue homeostasis in epidermis, hair follicles, and cornea.

Cystatin M/E (CST6) is a nonredundant, epithelium-specific protease inhibitor with a presumed role in epidermal differentiation and tumor suppression. We have previously reported that cystatin M/E deficiency in Cst6(-/-) mice causes neonatal lethality because of excessive transepidermal water loss. Biochemical evidence suggests that cystatin M/E controls the activity of legumain, cathepsin L, cathepsin V, and transglutaminase-3. Using a genetic approach we sought to define the role of cystatin M/E in epithelial biology by identification of its target proteases and their downstream functions. Ablation of cathepsin L in a Cst6(-/-) background (Cst6(-/-)Ctsl(-/-) double-knockout mice) restored viability and resulted in normalization of stratum corneum morphology. Ablation of legumain or transglutaminase-3 in Cst6(-/-) mice, however, did not rescue the lethal phenotype. Intriguingly, both Cst6(-/-)Ctsl(-/-) and Cst6(-/-)Ctsl(+/-) mice were viable, but the absence of cystatin M/E caused scarring alopecia in adult animals. In the cornea of Cst6(-/-)Ctsl(+/-) mice, we observed keratitis, hyperplasia, and transition to a cornified epithelium. Evidence is provided that activation of cathepsin D and transglutaminase-1 are downstream events, dependent of cathepsin L activity. We conclude that a tightly regulated balance between cathepsin L and cystatin M/E is essential for tissue integrity in epidermis, hair follicles, and corneal epithelium.

The biology of cystatin M/E and its cognate target proteases.

Cystatin M/E is a member of a superfamily of evolutionarily-related cysteine protease inhibitors that provide regulatory and protective functions against uncontrolled proteolysis by cysteine proteases. Although most cystatins are ubiquitously expressed, high levels of cystatin M/E expression are mainly restricted to the epithelia of the skin (epidermis, hair follicles, sebaceous glands, and sweat glands) and to a few extracutaneous tissues. The identification of its physiological targets and the localization of these proteases in skin have suggested a regulatory role for cystatin M/E in epidermal differentiation. In vitro biochemical approaches as well as the use of in vivo mouse models have revealed that cystatin M/E is a key molecule in a biochemical pathway that controls skin barrier formation by the regulation of both crosslinking and desquamation of the stratum corneum. Cystatin M/E directly controls the activity of cathepsin V, cathepsin L, and legumain, thereby regulating the processing of transglutaminases. Misregulation of this pathway by unrestrained protease activity, as seen in cystatin M/E-deficient mice, leads to abnormal stratum corneum and hair follicle formation, as well as to severe disturbance of skin barrier function. Here, we review the current knowledge on cystatin M/E in skin barrier formation and its potential role as a tumor suppressor gene.

Colocalization of cystatin M/E and its target proteases suggests a role in terminal differentiation of human hair follicle and nail.

The cysteine protease inhibitor cystatin M/E is a key regulator of a biochemical pathway that leads to epidermal terminal differentiation by inhibition of its target proteases cathepsin L, cathepsin V, and legumain. Inhibition of cathepsin L is important in the cornification process of the skin, as we have recently demonstrated that cathepsin L is the elusive processing and activating protease for transglutaminase 3, an enzyme that is responsible for crosslinking of structural proteins in cornified envelope formation. Here, we study the localization of all players of this pathway in the human hair follicle and nail unit in order to elucidate their possible role in the biology of these epidermal appendages. We found that cathepsin L and transglutaminase 3 specifically colocalize in the hair bulb and the nail matrix, the regions that provide cells that terminally differentiate to the hair fiber and the nail plate, respectively. Furthermore, transglutaminase 3 also colocalizes with the structural proteins loricrin and involucrin, which are established transglutaminase substrates. These findings suggest that cathepsin L and transglutaminase 3 could be involved in the pathway that leads to terminal differentiation, not only in the epidermis but also in the human hair follicle and nail unit.

Colocalization of cystatin M/E and cathepsin V in lamellar granules and corneodesmosomes suggests a functional role in epidermal differentiation.

Cystatin M/E is a cysteine protease inhibitor with two distinct binding sites for papain-like cysteine proteases (family C1) and the asparaginyl endopeptidase (AEP) legumain of family C13. We have previously demonstrated that deficiency of cystatin M/E in mice causes ichthyosiform skin changes and barrier disruption, which could be caused by unrestrained AEP activity. Recently, we provided biochemical evidence that human cathepsin V (CTSV) and cathepsin L (CTSL) are additional biological targets for human cystatin M/E. To address the possible role of these three proteases and their inhibitor in epidermal differentiation, we investigated the localization of these proteins in normal human skin. Whereas CTSL and AEP were broadly expressed in epithelial cells of the skin, we found a specific colocalization of cystatin M/E and CTSV in the stratum granulosum and in the root sheets of the hair follicle, using immunofluorescence microscopy. Immunoelectron microscopy revealed that cystatin M/E and CTSV are separately transported within the lamellar granules. Cystatin M/E was also found in the extracellular space in the stratum corneum associated with corneodesmosomes, where it was closely associated with CTSV. Based on the striking stratum-specific colocalization of cystatin M/E and CTSV, we propose that these molecules could have an important role in epidermal differentiation and desquamation.

Cystatin M/E is a high affinity inhibitor of cathepsin V and cathepsin L by a reactive site that is distinct from the legumain-binding site. A novel clue for the role of cystatin M/E in epidermal cornification.

Cystatin M/E is a high affinity inhibitor of the asparaginyl endopeptidase legumain, and we have previously reported that both proteins are likely to be involved in the regulation of stratum corneum formation in skin. Although cystatin M/E contains a predicted binding site for papain-like cysteine proteases, no high affinity binding for any member of this family has been demonstrated so far. We report that human cathepsin V (CTSV) and human cathepsin L (CTSL) are strongly inhibited by human cystatin M/E. Kinetic studies show that Ki values of cystatin M/E for the interaction with CTSV and CTSL are 0.47 and 1.78 nM, respectively. On the basis of the analogous sites in cystatin C, we used site-directed mutagenesis to identify the binding sites of these proteases in cystatin M/E. We found that the W135A mutant was rendered inactive against CTSV and CTSL but retained legumain-inhibiting activity. Conversely, the N64A mutant lost legumain-inhibiting activity but remained active against the papain-like cysteine proteases. We conclude that legumain and papain-like cysteine proteases are inhibited by two distinct non-overlapping sites. Using immunohistochemistry on normal human skin, we found that cystatin M/E co-localizes with CTSV and CTSL. In addition, we show that CTSL is the elusive enzyme that processes and activates epidermal transglutaminase 3. The identification of CTSV and CTSL as novel targets for cystatin M/E, their (co)-expression in the stratum granulosum of human skin, and the activity of CTSL toward transglutaminase 3 strongly imply an important role for these enzymes in the differentiation process of human epidermis.