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.

Development of an in vitro Functional Assay to Evaluate the Occlusive Properties of Moisturizers on Dry Skin.

INTRODUCTION: Dry skin is a hallmark of impaired skin barrier function. Moisturizers are a mainstay of treatment to help the skin retain moisture, and there is a high consumer demand for effective products. However, the development and optimization of new formulations are hampered due to lack of reliable efficacy measures using in vitro models. METHODS: In this study, a microscopy-based barrier functional assay was developed using an in vitro skin model of chemically induced barrier damage to evaluate the occlusive activity of moisturizers. RESULTS: The assay was validated by demonstrating the different effects on barrier function between humectant (glycerol) and occlusive (petrolatum). Significant changes in barrier function were observed upon tissue disruption, which was ameliorated by commercial moisturizing products. CONCLUSION: This newly developed experimental method may be helpful to develop new and improved occlusive moisturizers for the treatment of dry skin conditions.

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.

Efficacy and Tolerability of a Novel Topical Treatment for Neck: A Randomized, Double-blind, Regimen-Controlled Study.

The neck plays a telling role as an age indicator. Due to its anatomy and function, neck skin ages differently than facial skin and special considerations need to be taken when providing treatment. A randomized, double-blind, regimen-controlled study was conducted to assess the efficacy and tolerability of a novel topical cosmetic cream (NCC) specifically tailored to address the signs of skin aging of the neck and décolletage. Twice daily application of NCC significantly improved skin sagging/laxity of the neck as well as the appearance of fine and coarse lines/wrinkles, crepiness, tactile roughness, overall skin texture, hyperpigmentation, skin tone evenness, and radiance. NCC also significantly improved the appearance of fine and coarse lines/wrinkles, tactile roughness, hyperpigmentation, skin tone evenness, and radiance of the décolletage. Investigator assessments were corroborated by objective cutometer measurements that demonstrated improved skin firmness and elasticity. In vitro analysis in human 3D skin models show that stimulation of neocollagenesis and neoelastogenesis as well as support of cellular proteostasis through proteasome and autophagy activation are potential mechanisms of action for the observed clinical outcomes. J Drugs Dermatol. 2021;20(2):184-191. doi:10.36849/JDD.5819 THIS ARTICLE HAD BEEN MADE AVAILABLE FREE OF CHARGE. PLEASE SCROLL DOWN TO ACCESS THE FULL TEXT OF THIS ARTICLE WITHOUT LOGGING IN. NO PURCHASE NECESSARY. PLEASE CONTACT THE PUBLISHER WITH ANY QUESTIONS.

Clinical Benefits of Circadian-based Antioxidant Protection and Repair.

Skin activities follow endogenous circadian rhythms resulting in differences between daytime and nighttime properties. To address the variations in skin needs, a novel circadian-based dual serum system (LVS) was developed. A 12-week, double-blind, randomized, regimen-controlled, multi-center study was conducted to assess the efficacy and tolerability of LVS on subjects presenting with moderate-severe photodamage. 61 Female subjects (36–65 years; Fitzpatrick skin types I–VI) completed the study. The active group received LVS (daytime serum and nighttime serum) and basic skin care regimen (moisturizer and SPF 35 sunscreen), while the control group received the basic skin care regimen only. In addition to clinical grading, subject self-assessment questionnaires, and standardized photography, punch biopsies were taken in a subset of subjects for immunohistochemistry. Additionally, swab samples were taken for skin surface oxidation analysis. Significant improvements over control were observed in the active group in Radiance (weeks 4, 8, and 12), Overall Photodamage, Tactile Toughness, and Global Fine Lines/Wrinkles (week 12). Biopsy results, skin swab analysis and standardized photographs support the clinical grading findings. At all follow-up visits, LVS was consistently highly rated over control by subjects, with a significant proportion of subjects agreeing at week 12 that LVS “improved the radiance of my skin,” and “improved the overall health and look of my skin”. Results from this study suggest that LVS may provide essential protective and reparative effects to skin exposed to the damaging effects of environmental factors, and also demonstrates the value of including skin circadian rhythm-based concepts in a topical skincare regimen. J Drugs Dermatol. 2020;19(12): doi:10.36849/JDD.2020.5355.

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.

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.

Development and Clinical Assessment of a Comprehensive Product for Pigmentation Control in Multiple Ethnic Populations.

BACKGROUND: Pigmentary changes in people of different ethnic origins are controlled by slight variations in key biological pathways leading to different outcomes from the same treatment. It is important to develop and test products for desired outcomes in varying ethnic populations. OBJECTIVES: To develop a comprehensive product (LYT2) that affects all major biological pathways controlling pigmentation and test for clinical efficacy and safety in different ethnic populations. METHODS: A thorough analysis of biological pathways was used to identify ingredient combinations for LYT2 that provided optimal melanin reduction in a 3-D skin model. Expression of four key genes for melanogenesis, TYR, TYRP-1, DCT, and MITF was analyzed by qPCR. Clinical study was conducted to compare the efficacy and tolerability of LYT2 against 4% hydroquinone (HQ). RESULTS: Average melanin suppression by LYT2 in 7 independent experiments was 45%. All four key genes show significant down- regulation of expression. LYT2 provided statistically significant reductions in mean overall hyperpigmentation grades as early as week 2 compared to baseline, with continued significant improvements through week 12 in all ethnic groups tested. CONCLUSION: We have successfully combined management of 6 categories of pathways related to melanogenesis: melanocyte activation, melanosome development, melanin production, melanin distribution, keratinocyte turnover, and barrier function to create a comprehensive HQ-free product. The outcome clearly shows greater pigmentation control with LYT2 compared to other HQ-free products in skin tissue models and earlier control in clinical studies compared to 4% HQ. Clinical study shows pigmentation control benefits of LYT2 in people of Caucasian, Hispanic, and African ethnic origins. J Drugs Dermatol. 2016;15(12):1562-1570.

Rejuvenating Hydrator: Restoring Epidermal Hyaluronic Acid Homeostasis With Instant Benefits.

Skin aging is a combination of multifactorial mechanisms that are not fully understood. Intrinsic and extrinsic factors modulate skin aging, activating distinctive processes that share similar molecular pathways. One of the main characteristics of youthful skin is its large capacity to retain water, and this decreases significantly as we age. A key molecule involved in maintaining skin hydration is hyaluronic acid (HA). Concentration of HA in the skin is determined by the complex balance between its synthesis, deposition, association with cellular structures, and degradation. HA bio-equivalency and bio-compatibility have been fundamental in keeping this macromolecule as the favorite of the skincare industry for decades. Scientific evidence now shows that topically applied HA is unable to penetrate the skin and is rapidly degraded on the skin surface. SkinMedica's HA5 Rejuvenating Hydrator (SkinMedica Inc., an Allergan company, Irvine, CA) promotes restoration of endogenous epidermal HA homeostasis and provides instant smoothing and hydration of the skin. These dual benefits are accomplished through the combination of 2 breakthrough technologies: 1) a unique blend of actives powered by SkinMedica proprietary flower-derived stem cell extract that restores the endogenous production of HA; and 2) a proprietary mix of 5 HA forms that plump the skin, decreasing the appearance of fine lines/wrinkles. Pre-clinical studies demonstrated that HA5 induces expression of key epidermal differentiation and barrier markers as well as epidermal HA synthases. A decrease expression of hyaluronidases was also observed upon HA5 application. Initial clinical studies showed that within 15 minutes of application, HA5 instantly improves the appearance of fine lines/wrinkles and skin hydration. Subjects that continue using HA5 (for 8 weeks) demonstrated significant improvements in fine lines/wrinkles, tactile roughness, and skin hydration. In summary, the blend of these 2 key technologies present in HA5 promotes restoration of endogenous epidermal HA while delivering instant smoothing effects.

Changes in fibrillin-1 expression, elastin expression and skin surface texture at sites of cultured epithelial autograft transplantation onto wounds from burn scar excision.

This study investigated the recovery process during which grafted cultured epithelium generated skin elasticity and skin surface microarchitecture. The subjects were 18 patients whose burn scars were excised at a depth not exposing the fat layer and who subsequently received cultured epithelial autografts. A total of 24 samples were obtained from the grafted sites: 6 samples within 6 weeks (stage 1), 5 samples after 6 weeks and within 6 months (stage 2), 6 samples after 6 months and within 18 months (stage 3) and 7 samples beyond 18 months (stage 4) of transplantation. These samples were evaluated by taking replicas of skin surface, and histological changes of fibrillin-1 and elastin. The expression patterns were classified using a grading scale. The grade of skin surface texture was significantly higher at stage 3 and marginally significantly higher at stage 4 compared with stage 1. The grade of fibrillin-1 was marginally significantly higher at stage 3 and significantly higher at stage 4 compared with stage 1. The grade of elastin was marginally significantly higher at stage 4 compared with stage 1. These results showed that it is important for patients to have skin care and avoid external forces for at least 18 months after transplantation.

Changes in the expression of epidermal differentiation markers at sites where cultured epithelial autografts were transplanted onto wounds from burn scar excision.

This study investigated the recovery process during which grafted cultured epithelium formed normal epidermis. The subjects were 18 patients whose burn scars were excised at a depth not exposing the fat layer and who subsequently received cultured epithelial autografts. A total of 24 samples were obtained from the grafted sites: 6 samples within 6 weeks (stage 1), 5 samples after 6 weeks and within 6 months (stage 2), 6 samples after 6 months and within 18 months (stage 3) and 7 samples beyond 18 months (stage 4) after transplantation. These samples were stained for monoclonal antibodies against filaggrin, transglutaminase (TG), cytokeratin 6 and involucrin. Their expressions were examined in the epidermis. The expression patterns were classified using a six-grade scale. The grades of filaggrin and TG were significantly higher at stage 3 and 4 compared with stage 1. There was a marginally significant increase in the grade of cytokeratin 6 at stage 3 and it was significantly higher at stage 4 compared with stage 1. These results showed that wound healing continued at a molecular level until the end of stage 3. The recovery of involucrin was delayed compared with that of other markers. TG and involucrin are thought to be regulated independently at the grafted sites.

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.

Early vascular deficits are correlated with delayed mammary tumorigenesis in the MMTV-PyMT transgenic mouse following genetic ablation of the NG2 proteoglycan.

INTRODUCTION: The neuron-glial antigen 2 (NG2) proteoglycan promotes pericyte recruitment and mediates pericyte interaction with endothelial cells. In the absence of NG2, blood vessel development is negatively impacted in several pathological models. Our goal in this study was to determine the effect of NG2 ablation on the early development and function of blood vessels in mammary tumors in the mammary tumor virus-driven polyoma middle T (MMTV-PyMT) transgenic mouse, and to correlate these vascular changes with alterations in mammary tumor growth. METHODS: Three different tumor paradigms (spontaneous tumors, transplanted tumors, and orthotopic allografts of tumor cell lines) were used to investigate the effects of NG2 ablation on breast cancer progression in the MMTV-PyMT transgenic mouse. In addition to examining effects of NG2 ablation on mammary tumor growth, we also investigated effects on the structure and function of tumor vasculature. RESULTS: Ablation of NG2 led to reduced early progression of spontaneous, transplanted, and orthotopic allograft mammary tumors. NG2 was not expressed by the mammary tumor cells themselves, but instead was found on three components of the tumor stroma. Microvascular pericytes, myeloid cells, and adipocytes were NG2-positive in both mouse and human mammary tumor stroma. The effect of NG2 on tumor progression therefore must be stromal in nature. Ablation of NG2 had several negative effects on early development of the mammary tumor vasculature. In the absence of NG2, pericyte ensheathment of endothelial cells was reduced, along with reduced pericyte maturation, reduced sprouting of endothelial cells, reduced assembly of the vascular basal lamina, and reduced tumor vessel diameter. These early deficits in vessel structure are accompanied by increased vessel leakiness, increased tumor hypoxia, and decreased tumor growth. NG2 ablation also diminishes the number of tumor-associated and TEK tyrosine kinase endothelial (Tie2) expressing macrophages in mammary tumors, providing another possible mechanism for reducing tumor vascularization and growth. CONCLUSIONS: These results emphasize the importance of NG2 in mediating pericyte/endothelial cell communication that is required for proper vessel maturation and function. In the absence of normal pericyte/endothelial cell interaction, poor vascular function results in diminished early progression of mammary tumors.

Serpin squamous cell carcinoma antigen inhibits UV-induced apoptosis via suppression of c-JUN NH2-terminal kinase.

Protection from ultraviolet (UV) irradiation is a fundamental issue for living organisms. Although melanin's critical role in the protection of basal keratinocytes is well understood, other factors remain essentially unknown. We demonstrate that up-regulation of squamous cell carcinoma antigen-1 (SCCA1) suppresses c-Jun NH2-terminal kinase-1 (JNK1) and thus blocks UV-induced keratinocyte apoptosis. We found that serpin SCCA1 is markedly elevated in the top layers of sun-exposed or UV-irradiated epidermis. UV-induced apoptosis was significantly decreased when SCCA was overexpressed in 3T3/J2 cells. It was significantly increased when SCCA was down-regulated with small interfering RNA in HaCaT keratinocytes. A search for SCCA-interacting molecules showed specific binding with phosphorylated JNK. Interestingly, SCCA1 specifically suppressed the kinase activity of JNK1. Upon exposure of keratinocytes to UV, SCCA1 was bound to JNK1 and transferred to the nucleus. Involucrin promoter-driven SCCA1 transgenic mice showed remarkable resistance against UV irradiation. These findings reveal an unexpected serpin function and define a novel UV protection mechanism in human skin.

NG2 proteoglycan expression in mouse skin: altered postnatal skin development in the NG2 null mouse.

In early postnatal mouse skin, the NG2 proteoglycan is expressed in the subcutis, the dermis, the outer root sheath of hair follicles, and the basal keratinocyte layer of the epidermis. With further development, NG2 is most prominently expressed by stem cells in the hair follicle bulge region, as also observed in adult human skin. During telogen and anagen phases of the adult hair cycle, NG2 is also found in stem cell populations that reside in dermal papillae and the outer root sheaths of hair follicles. Ablation of NG2 produces alterations in both the epidermis and subcutis layers of neonatal skin. Compared with wild type, the NG2 null epidermis does not achieve its full thickness due to reduced proliferation of basal keratinocytes that serve as the stem cell population in this layer. Thickening of the subcutis is also delayed in NG2 null skin due to deficiencies in the adipocyte population.

Antitumor activity of rapamycin in a transgenic mouse model of ErbB2-dependent human breast cancer.

The ErbB2 (Neu) receptor tyrosine kinase is frequently overexpressed in human breast cancers, and this phenotype correlates with a poor clinical prognosis. We examined the effects of the mammalian target of rapamycin inhibitor, rapamycin, on mammary tumorigenesis in transgenic mice bearing an activated ErbB2 (NeuYD) transgene in the absence or presence of a second transgene encoding vascular endothelial growth factor (VEGF). Treatment of NeuYD or NeuYD x VEGF mice with rapamycin dramatically inhibited tumor growth accompanied by a marked decrease in tumor vascularization. Two key events that may underlie the antitumor activity of rapamycin were decreased expression of ErbB3 and inhibition of hypoxia-inducible factor-1-dependent responses to hypoxic stress. Rapamycin exposure caused only a modest inhibition of the proliferation of tumor-derived cell lines in standard monolayer cultures, but dramatically inhibited the growth of the same cells in three-dimensional cultures, due in part to the induction of apoptotic cell death. These studies underscore the therapeutic potential of mammalian target of rapamycin inhibitors in ErbB2-positive breast cancers and indicate that, relative to monolayer cultures, three-dimensional cell cultures are more predictive in vitro models for studies of the antitumor mechanisms of rapamycin and related compounds.

Pancreatic Tissue Transplanted in TheraCyte Encapsulation Devices Is Protected and Prevents Hyperglycemia in a Mouse Model of Immune-Mediated Diabetes.

Type 1 diabetes (T1D) is characterized by destruction of glucose-responsive insulin-producing pancreatic ß-cells and exhibits immune infiltration of pancreatic islets, where CD8 lymphocytes are most prominent. Curative transplantation of pancreatic islets is seriously hampered by the persistence of autoreactive immune cells that require high doses of immunosuppressive drugs. An elegant approach to confer graft protection while obviating the need for immunosuppression is the use of encapsulation devices that allow for the transfer of oxygen and nutrients, yet prevent immune cells from making direct contact with the islet grafts. Here we demonstrate that macroencapsulation devices (TheraCyte) loaded with neonatal pancreatic tissue and transplanted into RIP-LCMV.GP mice prevented disease onset in a model of virus-induced diabetes mellitus. Histological analyses revealed that insulin-producing cells survived within the device in animal models of diabetes. Our results demonstrate that these encapsulation devices can protect from an immune-mediated attack and can contain a sufficient amount of insulin-producing cells to prevent overt hyperglycemia.

Tolerance induction and reversal of diabetes in mice transplanted with human embryonic stem cell-derived pancreatic endoderm.

Type 1 diabetes (T1D) is an autoimmune disease caused by T cell-mediated destruction of insulin-producing ß cells in the islets of Langerhans. In most cases, reversal of disease would require strategies combining islet cell replacement with immunotherapy that are currently available only for the most severely affected patients. Here, we demonstrate that immunotherapies that target T cell costimulatory pathways block the rejection of xenogeneic human embryonic-stem-cell-derived pancreatic endoderm (hESC-PE) in mice. The therapy allowed for long-term development of hESC-PE into islet-like structures capable of producing human insulin and maintaining normoglycemia. Moreover, short-term costimulation blockade led to robust immune tolerance that could be transferred independently of regulatory T cells. Importantly, costimulation blockade prevented the rejection of allogeneic hESC-PE by human PBMCs in a humanized model in vivo. These results support the clinical development of hESC-derived therapy, combined with tolerogenic treatments, as a sustainable alternative strategy for patients with T1D.