ZFP750 affects the cutaneous barrier through regulating lipid metabolism

Advance in Multi-omics Research Strategies on Cholesterol Metabolism in Psoriasis

The skin is a complex and dynamic organ where homeostasis is maintained through the intricate interplay between the immune system and metabolism, particularly cholesterol metabolism. Various factors such as cytokines, inflammatory mediators, cholesterol metabolites, and metabolic enzymes play crucial roles in facilitating these interactions. Dysregulation of this delicate balance contributes to the pathogenic pathways of inflammatory skin conditions, notably psoriasis. In this article, we provide an overview of omics biomarkers associated with psoriasis in relation to cholesterol metabolism. We explore multi-omics approaches that reveal the communication between immunometabolism and psoriatic inflammation. Additionally, we summarize the use of multi-omics strategies to uncover the complexities of multifactorial and heterogeneous inflammatory diseases. Finally, we highlight potential future perspectives related to targeted drug therapies and research areas that can advance precise medicine. This review aims to serve as a valuable resource for those investigating the role of cholesterol metabolism in psoriasis.

Skin Barrier in Atopic Dermatitis

A compromised permeability barrier is a hallmark of atopic dermatitis (AD). Localized to the outermost skin layer, the stratum corneum (SC) is critically dependent on terminal differentiation of epidermal keratinocytes, which transform into protein-rich corneocytes surrounded by extracellular lamellae of unique epidermal lipids, conferring permeability barrier function. These structures are disrupted in AD. A leaky barrier is prone to environmental insult, which in AD elicits type 2-dominant inflammation, in turn resulting in a vicious cycle further impairing the SC structure. Therapies directed at enforcing SC structure and anti-inflammatory strategies administered by topical and systemic route as well as UV therapy have differential effects on the permeability barrier. The expanding armamentarium of therapeutic modalities for AD treatment warrants optimization of their effects on permeability barrier function.

12th Tuscany Retreat on Cancer Research and Apoptosis: Genetic profiling, resistance mechanisms and novel treatment concepts in cancer and neurodegeneration

The 12th Tuscany Retreat on Cancer Research and Apoptosis was held on August 19-26, 2023. The biennial retreat aims to bring together scientists who advance research in cancer, cell death, and neurodegenerative diseases. Topics covered ranged from drug resistance in cancer to insights into novel molecular cell signaling mechanisms and targets, all related to the pathways and molecules that regulate programmed cell death and the diseases that result from the dysregulation of programmed cell death. In this meeting review, we summarize the content of the most recent retreat.

Dietary lipid is largely deposited in skin and rapidly affects insulating properties

Skin has been shown to be a regulatory hub for energy expenditure and metabolism: mutations of skin lipid metabolism enzymes can change the rate of thermogenesis and susceptibility to diet-induced obesity. However, little is known about the physiological basis for this function. Here we show that the thermal properties of skin are highly reactive to diet: within three days, a high fat diet reduces heat transfer through skin. In contrast, a dietary manipulation that prevents obesity accelerates energy loss through skins. We found that skin was the largest target in a mouse body for dietary fat delivery, and that fat was assimilated both by epidermis and by dermal white adipose tissue. Dietary triglyceride acyl groups persist in skin for weeks after feeding. Using multi-modal lipid profiling, we have implicated both keratinocytes and sebocytes in the altered lipids which correlate with thermal function. In response to high fat feeding, wax diesters and ceramides accumulate, and triglycerides become more saturated. In contrast, in response to the dramatic loss of adipose tissue that accompanies restriction of the branched chain amino acid isoleucine, skin becomes highly heat-permeable: skins shows limited uptake of dietary lipids and editing of wax esters, and acquires a signature of depleted signaling lipids, which include the acyl carnitines and lipid ethers. We propose that skin should be routinely included in physiological studies of lipid metabolism, given the size of the skin lipid reservoir and its adaptable functionality.

ZNF750 Regulates Skin Barrier Function by Driving Cornified Envelope and Lipid Processing Pathways

The epidermis is a constantly renewing stratified epithelial tissue that provides essential protective barrier functions. The major barrier is located at the outermost layers of the epidermis, formed by terminally differentiated keratinocytes reinforced by proteins of their cornified envelope and sequestered intercellular lipids. Disruptions to epidermal differentiation characterize various skin disorders. ZNF750 is an epithelial transcription factor essential for in vitro keratinocyte differentiation, whose truncating mutation in humans causes autosomal dominant psoriasis-like skin disease. In this study, we utilized an epidermal-specific Znf750 conditional knockout mouse model to uncover the role ZNF750 plays in epidermal development. We show that deletion of Znf750 in the developing skin does not block epidermal differentiation completely, suggesting in vivo compensatory feedback mechanisms, although it does result in impaired barrier function and perinatal lethality. Molecular dissection revealed ultrastructural defects in the differentiated layers of the epidermis, accompanied by alterations in the expression of ZNF750-dependent genes encoding key cornified envelope precursor proteins and lipid-processing enzymes, including gene subsets known to be mutated in human skin diseases involving impaired barrier function. Together, our findings provide molecular insights into the pathogenesis of human skin disease by linking ZNF750 to a subset of epidermal differentiation genes involved in barrier formation pathways.

Epigenetic priming of an epithelial enhancer by p63 and CTCF controls expression of a skin-restricted gene XP33

The transcription factor p63 is a renowned master regulator of gene expression of stratified epithelia. While multiple proteins have been identified as p63 bona fide targets, little is known about non-coding RNAs (ncRNAs) whose transcription is controlled by p63. Here, we describe a skin-specific non-coding RNA XP33 as a novel target of p63. XP33 levels are increased during keratinocyte differentiation in vitro, while its depletion results in decreased expression of late cornified gene LCE2D. By using publicly available multi-omics data, we show that CTCF and p63 establish an epithelial enhancer to prime XP33 transcription in a tissue-restricted manner. XP33 promoter and enhancer form a chromatin loop exclusively in keratinocytes but not in other cell types. Moreover, the XP33 enhancer is occupied by differentiation-specific factors that control XP33 transcription. Altogether, we identify a tissue-specific non-coding RNA whose expression is epigenetically regulated by p63 and CTCF.