Distinct human Langerhans cell subsets orchestrate reciprocal functions and require different developmental regulation.

Langerhans cells (LCs) play a pivotal role in skin homeostasis, and the heterogeneity of LCs has long been considered. In this study, we have identified two steady-state (LC1 and LC2) and two activated LC subsets in the epidermis of human skin and in LCs derived from CD34+ hemopoietic stem cells (HSC-LCs) by utilizing single-cell RNA sequencing and mass cytometry. Analysis of HSC-LCs at multiple time-points during differentiation revealed that EGR1 and Notch signaling were among the top pathways regulating the bifurcation of LC1 and LC2. LC1 were characterized as classical LCs, mainly related to innate immunity and antigen processing. LC2 were similar to monocytes or myeloid dendritic cells, involving in immune responses and leukocyte activation. LC1 remained stable under inflammatory microenvironment, whereas LC2 were prone to being activated and demonstrated elevated expression of immuno-suppressive molecules. We revealed distinct human LC subsets that require different developmental regulation and orchestrate reciprocal functions.

Placing steroid hormones within the human ABCC3 transporter reveals a compatible amphiphilic substrate-binding pocket.

The human ABC transporter ABCC3 (also known as MRP3) transports a wide spectrum of substrates, including endogenous metabolites and exogenous drugs. Accordingly, it participates in multiple physiological processes and is involved in diverse human diseases such as intrahepatic cholestasis of pregnancy, which is caused by the intracellular accumulation of bile acids and estrogens. Here, we report three cryogenic electron microscopy structures of ABCC3: in the apo-form and in complexed forms bound to either the conjugated sex hormones ß-estradiol 17-(ß-D-glucuronide) and dehydroepiandrosterone sulfate. For both hormones, the steroid nuclei that superimpose against each other occupy the hydrophobic center of the transport cavity, whereas the two conjugation groups are separated and fixed by the hydrophilic patches in two transmembrane domains. Structural analysis combined with site-directed mutagenesis and ATPase activity assays revealed that ABCC3 possesses an amphiphilic substrate-binding pocket able to hold either conjugated hormone in an asymmetric pattern. These data build on consensus features of the substrate-binding pocket of MRPs and provide a structural platform for the rational design of inhibitors.

Langerhans cells and skin immune diseases.

Langerhans cells (LCs) are the key antigen-presenting cells in the epidermis in normal conditions and respond differentially to environmental and/or endogenous stimuli, exerting either proinflammatory or anti-inflammatory effects. Current knowledge about LCs mainly originates from studies utilizing mouse models, whereas with the development of single-cell techniques, there has been significant progress for human LCs, which has updated our understanding of the phenotype, ontogeny, differentiation regulation, and function of LCs. In this review, we delineated the progress of human LCs and summarized LCs' function in inflammatory skin diseases, providing new ideas for precise regulation of LC function in the prevention and treatment of skin diseases.

Serine/Arginine-Rich Splicing Factor 7 Knockdown Inhibits Aerobic Glycolysis and Growth in HepG2 Cells by Regulating PKM2 Expression.

Serine/arginine-rich splicing factors (SRSFs), part of the serine/arginine-rich (SR) protein family, play a crucial role in precursor RNA splicing. Abnormal expression of SRSFs in tumors can disrupt normal RNA splicing, contributing to tumor progression. Notably, SRSF7 has been found to be upregulated in hepatocellular carcinoma (HCC), yet its specific role and molecular mechanisms in HCC pathogenesis are not fully understood. We investigated the expression and prognostic significance of SRSF7 in HCC using bioinformatics database analysis. In HepG2 cells, the expressions of SRSF7 and glycolytic enzymes were analyzed using qRT-PCR, and Western blot. Glucose uptake and lactate production were quantified using relevant reagent kits. Additionally, cell proliferation, clonogenicity, invasion, and apoptosis were evaluated using MTS assay, clonal formation assay, Transwell assay, and mitochondrial membrane potential assay, respectively. This study demonstrated significant overexpression of SRSF7 in HCC tissue, correlating with poor prognosis. Knockdown of SRSF7 in HepG2 cells resulted in inhibited proliferation, clonogenicity, and invasion, while apoptosis was enhanced. This knockdown also decreased glucose uptake and lactate production, along with a reduction in the expression of glucose transporter 1 (GLUT1) and lactate dehydrogenase A (LDHA). Furthermore, SRSF7 downregulation increased the pyruvate kinase muscle 1 (PKM1)/PKM2 ratio. The glycolytic boost due to PKM2 overexpression partially counteracted the effects of SRSF7 silencing on HepG2 cell growth. The knockdown of SRSF7 impairs aerobic glycolysis and growth in HepG2 cells by downregulating PKM2 expression.

Propionate alleviates itch in murine models of atopic dermatitis by modulating sensory TRP channels of dorsal root ganglion.

BACKGROUND: Itch is the most common symptom of atopic dermatitis (AD) and significantly decreases the quality of life. Skin microbiome is involved in AD pathogenesis, whereas its role in the regulation of itch remains elusive. In this study, we aimed to investigate the effects of skin microbial metabolite propionate on acute and chronic pruritus and to explore the mechanism. METHODS: Using various mouse models of itch, the roles of propionate were explored by behavioral tests and histopathology/immunofluorescent analysis. Primary-cultured dorsal root ganglion neurons and HEK293 cells expressing recombinant human TRP channels were utilized for in vitro calcium imaging/in vivo miniature two-photon imaging in combination with electrophysiology and molecular docking approaches for investigation of the mechanism. RESULTS: Propionate significantly alleviated itch and alloknesis in various mouse models of pruritus and AD and decreased the density of intraepidermal nerve fibers. Propionate reduced the responsiveness of dorsal root ganglion neurons to pruritogens in vitro, attenuated the hyper-excitability in sensory neurons in MC903-induced AD model, and inhibited capsaicin-evoked hTRPV1 currents (IC50 = 20.08 ± 1.11 µM) via interacting with the vanilloid binding site. Propionate also decreased the secretion of calcitonin gene-related peptide by nerves in MC903-induced AD mouse model, which further attenuated itch and skin inflammation. CONCLUSION: Our study revealed a protective effect of propionate against persistent itch through direct modulation of sensory TRP channels and neuropeptide production in neurons. Regulation of itch via the skin microbiome might be a novel strategy for the treatment of AD.

Advances in ß-Diketocyclisation of Curcumin Derivatives and their Antitumor Activity.

Curcumin, derived from the popular spice turmeric, is a pharmacologically active polyphenol. Curcumin's therapeutic activity has been extensively studied in recent decades, with reports implicating curcumin in many biological activities, particularly, its significant anticancer activity. However, its potential as an oral administration product is hampered by poor bioavailability, which is associated with a variety of factors, including low water solubility, poor intestinal permeability, instability, and degradation at alkaline pH. To improve its bioavailability, modifying ß-diketone curcumin with heterocycles, such as pyrazole, isoxazole and triazole is a powerful strategy. Derivatives are synthesized while maintaining the basic skeleton of curcumin. The ß-diketone cyclized curcumin derivatives are regulators of multiple molecular targets, which play vital roles in a variety of cellular pathways. In some literatures, structurally modified curcumin derivatives have been compared with curcumin, and the former has enhanced biological activity, improved water solubility and stability. Therefore, the scope of this review is to report the most recently synthesized heterocyclic derivatives and to classify them according to their chemical structures. Several of the most important and effective compounds are reviewed by introducing different active groups into the ß-diketone position to achieve better therapeutic efficacy and bioavailability.

Global, regional, and national incidence and prevalence of systemic sclerosis.

OBJECTIVES: To estimate the global and country-specific unbiased epidemiological data of SSc. METHODS: Epidemiological studies were systematically searched in four databases. A Bayesian hierarchical linear mixed model was constructed to estimate epidemiological data. RESULTS: 82 studies were included and epidemiological data on SSc were missing for 83.9% of countries worldwide. The global SSc incidence and newly diagnosed population were estimated to be 8.64 per 100,000 person-years (1.78-23.57) and 0.67 million (0.14-1.84) people annually, respectively. Regarding prevalence, the global SSc prevalence and affected population were 18.87 per 100,000 persons (1.55-25.28) and 1.47 million (0.12-1.97) people, respectively. Relatively higher incidence and prevalence were observed in females, adults, and high-income level countries. CONCLUSIONS: We provide a comprehensive synthesis of SSc epidemiology and fill data gaps in most countries. Especially in low- and middle-income countries, epidemiological studies of SSc are insufficient. Further large-scale and standardized reported epidemiological investigations of SSc are imperative.

Global epidemiology of systemic lupus erythematosus: a comprehensive systematic analysis and modelling study.

OBJECTIVES: To quantify global, regional and country-specific estimates of epidemiology of systemic lupus erythematosus (SLE). METHODS: Four databases were systematically searched, and a Bayesian hierarchical linear mixed model was constructed to estimate the global, regional, and country-specific incidence and prevalence of SLE. RESULTS: 112 studies met the inclusion criteria. The global SLE incidence and newly diagnosed population were estimated to be 5.14 (1.4 to 15.13) per 100 000 person-years and 0.40 million people annually, respectively. In women, the values were 8.82 (2.4 to 25.99) per 100 000 person-years and 0.34 million people annually, while in men, the estimates were 1.53 (0.41 to 4.46) per 100 000 person-years and 0.06 million people annually, respectively. Poland, the USA and Barbados had the highest estimates of SLE incidence. Regarding prevalence, the global SLE prevalence and affected population were estimated to be 43.7 (15.87 to 108.92) per 100 000 persons and 3.41 million people, respectively. In women, the values were 78.73 (28.61 to 196.33) per 100 000 persons and 3.04 million people, while in men the estimates were 9.26 (3.36 to 22.97) per 100 000 persons and 0.36 million people, respectively. The United Arab Emirates, Barbados and Brazil had the highest SLE prevalence. In addition to regional and sex differences, age and prevalence estimation method (period or point prevalence) differences could also lead to variations in epidemiological SLE findings. CONCLUSIONS: Epidemiological data on SLE are lacking for 79.8% of countries worldwide. The epidemiology of SLE varies substantially between different sex and age groups and is distributed unequally among geographical regions; specifically, SLE occurs more frequently in high-income countries.

Differential changes in the gut microbiota between extrinsic and intrinsic atopic dermatitis.

Elevated serum level of total and (or) allergen-specific IgE is one of the key features of atopic dermatitis (AD). Previous studies have shown that the gut microbiome mediates interactions between external exposures and the immune system in AD; however, the relationship between the gut microbiota and IgE remains unclear. In the present study, analyses of environmental exposures for 250 AD patients and 138 healthy volunteers revealed an association between hygiene levels in the residential environment and the occurrence of AD and the IgE level. Metagenomic sequencing of the gut microbiota from 68 AD patients and 77 healthy controls showed that AD patients had a distinct gut microbiota composition; moreover, while L-histidine degradation was enriched in healthy controls, L-histidine biosynthesis was enriched in AD patients. Extrinsic and intrinsic AD showed different enrichment patterns of specific microbes and differential associations of functional pathways. Our study indicated that elevated levels of IgE in AD were related to specific microbes in the gut microbiota, which showed extensive interactions with environmental factors.

Mechanisms underlying the formation of complex color patterns on Nigella orientalis (Ranunculaceae) petals.

Complex color patterns on petals are widespread in flowering plants, yet the mechanisms underlying their formation remain largely unclear. Here, by conducting detailed morphological, anatomical, biochemical, optical, transcriptomic, and functional studies, we investigated the cellular bases, chromogenic substances, reflectance spectra, developmental processes, and underlying mechanisms of complex color pattern formation on Nigella orientalis petals. We found that the complexity of the N. orientalis petals in color pattern is reflected at multiple levels, with the amount and arrangement of different pigmented cells being the key. We also found that biosynthesis of the chromogenic substances of different colors is sequential, so that one color/pattern is superimposed on another. Expression and functional studies further revealed that a pair of R2R3-MYB genes function cooperatively to specify the formation of the eyebrow-like horizontal stripe and the Mohawk haircut-like splatters. Specifically, while NiorMYB113-1 functions to draw a large splatter region, NiorMYB113-2 functions to suppress the production of anthocyanins from the region where a gap will form, thereby forming the highly specialized pattern. Our results provide a detailed portrait for the spatiotemporal dynamics of the coloration of N. orientalis petals and help better understand the mechanisms underlying complex color pattern formation in plants.

One-Pot Assembly of Dual-Site-Specific Antibody-Drug Conjugates via Glycan Remodeling and Affinity-Directed Traceless Conjugation.

The drug-to-antibody ratio (DAR) value and dual-drug combination greatly influence the therapeutic index of antibody-drug conjugates (ADCs). The reported approaches usually require multifunctional branched linkers, a combination of complicated technologies, or protein-protein ligation, which may incorporate multihydrophobic fragments or result in low coupling efficiency. Herein, we developed a facile and efficient one-pot method to assemble dual-site-specific ADCs with defined DARs at both the N-glycosylation site and K248 site, either with the same payloads or with two types of payloads. The constructed dual-site ADCs showed acceptable homogeneity, excellent buffer stability, and enhanced in vitro and in vivo efficiency.

Single-pixel imaging of a translational object.

Image-free tracking methods based on single-pixel detectors (SPDs) can track a moving object at a very high frame rate, but they rarely can achieve simultaneous imaging of such an object. In this study, we propose a method for simultaneously obtaining the relative displacements and images of a translational object. Four binary Fourier patterns and two differential Hadamard patterns are used to modulate one frame of the object and then modulated light signals are obtained by SPD. The relative displacements and image of the moving object can be gradually obtained along with the detection. The proposed method does not require any prior knowledge of the object and its motion. The method has been verified by simulations and experiments, achieving a frame rate of 3332 Hz to acquire relative displacements of a translational object at a spatial resolution of 128 × 128 pixels using a 20000-Hz digital micro-mirror device. This proposed method can broaden the application of image-free tracking methods and obtain spatial information about moving objects.

Identification of the Key Regulatory Genes Involved in Elaborate Petal Development and Specialized Character Formation in Nigella damascena (Ranunculaceae).

Petals can be simple or elaborate, depending on whether they have lobes, teeth, fringes, or appendages along their margins, or possess spurs, scales, or other types of modifications on their adaxial/abaxial side, or both. Elaborate petals have been recorded in 23 orders of angiosperms and are generally believed to have played key roles in the adaptive evolution of corresponding lineages. The mechanisms underlying the formation of elaborate petals, however, are largely unclear. Here, by performing extensive transcriptomic and functional studies on Nigella damascena (Ranunculaceae), we explore the mechanisms underlying elaborate petal development and specialized character formation. In addition to the identification of genes and programs that are specifically/preferentially expressed in petals, we found genes and programs that are required for elaborate rather than simple petal development. By correlating the changes in gene expression with those in petal development, we identified 30 genes that are responsible for the marginal/ventral elaboration of petals and the initiation of several highly specialized morphological characters (e.g., pseudonectaries, long hairs, and short trichomes). Expression and functional analyses further confirmed that a class I homeodomain-leucine zipper family transcription factor gene, Nigella damascena LATE MERISTEM IDENTITY1 (NidaLMI1), plays important roles in the development of short trichomes and bifurcation of the lower lip. Our results not only provide the first portrait of elaborate petal development but also pave the way to understanding the mechanisms underlying lateral organ diversification in plants.

Dysregulated lipidome of sebum in patients with atopic dermatitis.

BACKGROUND: Lipids are the major components of skin barrier, mainly produced by keratinocytes and sebaceous glands. Previous studies on barrier dysfunction of atopic dermatitis (AD) mainly focus on the lipids from keratinocytes, whereas the role of sebaceous gland-derived lipids in AD has long been underrecognized. METHODS: The sebum secreted on the skin surface of AD patients was measured using the Delfin Sebum Scale. Sebum was collected using Sebutape patches and subjected for liquid chromatography tandem-mass spectrometry (LC-MS/MS) analysis. Multivariate data analysis was applied to explore the relationship among the lipidome, clinical features, and sebaceous gland-related molecules. RESULTS: The amount of sebum secreted from sebaceous glands was decreased in AD patients and was negatively correlated with the barrier function and disease severity. LC-MS/MS revealed the lipidome of sebum, which clustered distinctly between AD patients and healthy individuals. Among the differential lipid subclasses, triglycerides (TG) were exclusively decreased in AD patients and correlated with disease severity. The first principal component scores of AD patients, which represented the main signature of the lipidome, were positively correlated with the SCORAD scores and were significantly different across the patient groups with differential clinical symptoms such as skin dryness and pruritus. Further analysis on the previously published transcriptome data revealed aberrant expression of lipid metabolism-related genes in non-lesional skin of AD patients, which was associated with skin inflammation and barrier dysfunction and mainly derived from inner root sheath keratinocytes and sebaceous gland cells. CONCLUSION: Atopic dermatitis patients demonstrated a deviated lipidome of sebum and aberrant lipid metabolism in sebaceous glands, indicating a possible role of lipids from sebaceous glands in the pathogenesis of AD.

Global epidemiology of atopic dermatitis: a comprehensive systematic analysis and modelling study.

BACKGROUND: Atopic dermatitis (AD) is the leading cause of the global burden from skin disease; no study has provided global and country-specific epidemiological estimates of AD. OBJECTIVES: To quantify global, regional and country-specific estimates of the epidemiology of AD. METHODS: A comprehensive search for epidemiological studies in AD was conducted in four electronic databases (PubMed, Embase, Web of Science and China National Knowledge Infrastructure). A Bayesian hierarchical linear mixed model was constructed to calculate epidemiological estimates of AD considering the heterogeneity of regions, countries, type of diagnoses and age strata. RESULTS: In total, 344 studies met the inclusion criteria. Incidence varied substantially with the location and age of the surveyed participants. The global prevalence of AD and the population affected by AD were estimated to be 2.6% [95% uncertainty interval (UI) 1.9-3.5] and 204.05 million people, respectively. Around 101.27 million adults and 102.78 million children worldwide have AD, corresponding to prevalence rates of 2.0% (95% UI 1.4-2.6) and 4.0% (95% UI 2.8-5.3), respectively. Females were more likely to suffer from AD than males: the global prevalence of AD in females was 2.8% (95% UI 2.0-3.7%) and affected 108.29 million people, while in males the corresponding estimates were 2.4% (95% UI 1.7-3.3%) and 95.76 million people. CONCLUSIONS: Epidemiological AD data are lacking in 41.5% of countries worldwide. The epidemiology of AD varies substantially with age and sex and is distributed unequally across geographical regions.

Serum biomarker-based endotypes of atopic dermatitis in China and prediction for efficacy of dupilumab.

BACKGROUND: Atopic dermatitis (AD) is a highly heterogeneous disease clinically and biologically. Serum biomarkers have been utilized for endotype identification and have the potential to be predictors for treatment. OBJECTIVES: To explore the serum biomarker-based endotypes of Chinese patients with AD and to identify biomarkers for prediction of the efficacy of dupilumab. METHODS: Sera from 125 patients with moderate-to-severe AD and 60 normal controls (NC) were analysed for 24 cytokines/chemokines using the magnetic Luminex assay. After the patients received 16 weeks of dupilumab treatment, the efficacy was evaluated, and blood eosinophils, serum immunoglobulin (Ig) E and biomarkers were measured. RESULTS: Chinese patients with moderate-to-severe AD were characterized by T-helper (Th)2-dominant serum biomarkers that were mixed with differentially increased Th1-, Th17- and Th22-type cytokines/chemokines, and it was mainly Th2-type serum biomarkers that were positively correlated with disease severity and eosinophil counts. Adult (but not adolescent or elderly) patients with AD showed a consistent and more significant increase of biomarkers across different types of inflammation. The patients were grouped into two clusters by unsupervised k-means analysis, which were differentially associated with inflammation. Treatment with dupilumab decreased the levels of most cytokines/chemokines analysed. While there was no difference between the two clusters in the efficacy of dupilumab, baseline levels of CD25/soluble interleukin (sIL)-2Rα, IL-31 and IL-36ß were identified as predictive factors associated with the efficacy. CONCLUSIONS: Our study revealed two inflammation-related endotypes of Chinese patients with AD based on serum biomarkers. High levels of CD25/sIL-2Rα, IL-31 and IL-36ß might predict good efficacy of dupilumab treatment.

Validation of diagnostic criteria for atopic dermatitis and proposal of novel diagnostic criteria for adult and elderly Chinese populations: a multicentre, prospective, clinical setting-based study.

BACKGROUND: A previous validation study showed a very low sensitivity and higher specificity associated with Hanifin and Rajka criteria (H&R) and the UK Working Party criteria (UKWP) in diagnosing AD vs. the Chinese criteria of atopic dermatitis (AD) for children (CCAD). However, their diagnostic efficacy in adult and elderly Chinese populations remains unknown. OBJECTIVES: To validate the diagnostic efficacy of three sets of AD criteria in adult and elderly Chinese populations in a hospital setting. METHODS: A total of 1034 patients (aged 19-95 years) from five university hospital dermatological clinics were recruited. Medical history, dermatological examination, AD diagnosis and evaluation of AD severity were done by dermatologists. Each patient was investigated by two dermatologist panels, one to establish a clinical diagnosis, and the other to identify and record the major or minor signs of H&R criteria, UKWP criteria and CCAD. Taking clinical diagnosis as the reference, the diagnostic efficacy of three sets of diagnostic criteria was evaluated. The χ2 test or rank sum test were used for between-groups comparisons. RESULTS: CCAD had a higher sensitivity (84.0%), especially among mild and moderate cases of AD (72.7% and 90.3%, respectively), than the H&R (58.0%; P < 0.001) and UKWP criteria (56.0%; P < 0.001) in diagnosing AD. The specificity of CCAD (92.7%) was slightly lower than the H&R (97.3%; P < 0.001) or UKWP criteria (97.4%; P < 0.001). The CCAD had the highest Youden index (0.77), accuracy rate (0.90) and Kappa value (0.76) of the three sets of diagnostic criteria. CONCLUSIONS: Consistent with results in a population of Chinese children, although the H&R and UKWP criteria had a high specificity for diagnosing AD, their low sensitivity limited their use in adult and elderly Chinese patients. Based on the high sensitivity and favourable diagnostic efficacy, the CCAD is proposed for AD diagnosis in adult and elderly Chinese populations, especially for cases of mild and moderate AD.

Dehydroxylative Sulfonylation of Alcohols.

Described here is the R3P/ICH2CH2I-promoted dehydroxylative sulfonylation of alcohols with a variety of sulfinates. In contrast to previous dehydroxylative sulfonylation methods, which are usually limited to active alcohols, such as benzyl, allyl, and propargyl alcohols, our protocol can be extended to both active and inactive alcohols (alkyl alcohols). Various sulfonyl groups can be incorporated, such as CF3SO2 and HCF2SO2, which are fluorinated groups of interest in pharmaceutical chemistry and the installation of which has received increasing attention. Notably, all reagents are cheap and widely available, and moderate to high yields were obtained within 15 min of reaction time.

Ph3P/ICH2CH2I-promoted reductive deoxygenation of alcohols.

Owing to the ubiquity of the hydroxyl group, reductive deoxygenation of alcohols has become an active research area. The classic Barton-McCombie reaction suffers from a tedious two-step procedure. New efficient methods have been developed, but they have some limitations, such as a narrow substrate scope and the use of moisture-sensitive Lewis acids. In this work, we describe the Ph3P/ICH2CH2I-promoted reductive deoxygenation of alcohols with NaBH4. The process is applicable to benzyl, allyl and propargyl alcohols, and also to primary and secondary alcohols, demonstrating a wide substrate scope and a good level of functional group tolerance. This protocol features convenient operation and low cost of all reagents.