Single-cell RNA-Seq reveals the transcriptional landscape and heterogeneity of skin macrophages in Vsir-/- murine psoriasis

Identification of psoriasis-associated immune marker G3BP2 through single-cell RNA sequencing and meta analysis

Psoriasis is a chronic skin disease with an increasing prevalence each year. However, the mechanisms underlying its onset and progression remain unclear, and effective therapeutic targets are lacking. Therefore, we employs an innovative approach by combining single-cell RNA sequencing (scRNA-seq) with meta-analysis. This not only elucidates the potential mechanisms of psoriasis at the cellular level but also identifies immunoregulatory marker genes that play a statistically significant role in driving psoriasis progression through comprehensive analysis of multiple datasets. Skin tissue samples from 12 psoriasis patients underwent scRNA-seq, followed by quality control, filtering, PCA dimensionality reduction, and tSNE clustering analysis to identify T cell subtypes and differentially expressed genes (DEGs) in psoriatic skin tissue. Next, three psoriasis datasets were standardised and merged to identify differentially expressed genes (DEGs). Subsequently, weighted gene co-expression network analysis (WGCNA) was applied for clustering analysis of gene co-expression network modules and to assess the correlation between these modules and DEGs. Least absolute shrinkage and selection operator (LASSO) regression and receiver operating characteristic (ROC) curve analyses were conducted to select disease-specific genes and evaluate their diagnostic value. Single-cell data revealed nine cell types in psoriatic skin tissue, with seven T cell subtypes identified. Intersection analysis identified ADAM8 and G3BP2 as key genes. Through the integration of scRNA-seq and Meta analysis, we identified the immunoregulatory marker gene G3BP2, which is associated with the onset and progression of psoriasis and holds clinical significance. G3BP2 is speculated to promote the development of psoriasis by increasing the proportion of CD8+ T cells.

The Loss of PPARγ Expression and Signaling Is a Key Feature of Cutaneous Actinic Disease and Squamous Cell Carcinoma: Association with Tumor Stromal Inflammation

Given the importance of peroxisome proliferator-activated receptor (PPAR)-gamma in epidermal inflammation and carcinogenesis, we analyzed the transcriptomic changes observed in epidermal PPARγ-deficient mice (Pparg-/-epi). A gene set enrichment analysis revealed a close association with epithelial malignancy, inflammatory cell chemotaxis, and cell survival. Single-cell sequencing of Pparg-/-epi mice verified changes to the stromal compartment, including increased inflammatory cell infiltrates, particularly neutrophils, and an increase in fibroblasts expressing myofibroblast marker genes. A comparison of transcriptomic data from Pparg-/-epi and publicly available human and/or mouse actinic keratoses (AKs) and cutaneous squamous cell carcinomas (SCCs) revealed a strong correlation between the datasets. Importantly, PPAR signaling was the top common inhibited canonical pathway in AKs and SCCs. Both AKs and SCCs also had significantly reduced PPARG expression and PPARγ activity z-scores. Smaller reductions in PPARA expression and PPARα activity and increased PPARD expression but reduced PPARδ activation were also observed. Reduced PPAR activity was also associated with reduced PPARα/RXRα activity, while LPS/IL1-mediated inhibition of RXR activity was significantly activated in the tumor datasets. Notably, these changes were not observed in normal sun-exposed skin relative to non-exposed skin. Finally, Ppara and Pparg were heavily expressed in sebocytes, while Ppard was highly expressed in myofibroblasts, suggesting that PPARδ has a role in myofibroblast differentiation. In conclusion, these data provide strong evidence that PPARγ and possibly PPARα represent key tumor suppressors by acting as master inhibitors of the inflammatory changes found in AKs and SCCs.

Single-cell technologies in psoriasis

Psoriasis is a chronic and recurrent inflammatory skin disorder. The primary manifestation of psoriasis arises from disturbances in the cutaneous immune microenvironment, but the specific functions of the cellular components within this microenvironment remain unknown. Recent advancements in single-cell technologies have enabled the detection of multi-omics at the level of individual cells, including single-cell transcriptome, proteome, and metabolome, which have been successfully applied in studying autoimmune diseases, and other pathologies. These techniques allow the identification of heterogeneous cell clusters and their varying contributions to disease development. Considering the immunological traits of psoriasis, an in-depth exploration of immune cells and their interactions with cutaneous parenchymal cells can markedly advance our comprehension of the mechanisms underlying the onset and recurrence of psoriasis. In this comprehensive review, we present an overview of recent applications of single-cell technologies in psoriasis, aiming to improve our understanding of the underlying mechanisms of this disorder.

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.

The Efficacy of Imiquimod-Induced Psoriasis Model on Murine Cells

Keratinocytes are an essential component of the epidermis that undergoes constant proliferation and differentiation. However, the dysregulation of keratinocyte differentiation has been implicated in various skin disorders such as psoriasis. Imiquimod, otherwise known as IMQ, is a topical immunomodulator often used to induce psoriasis-like lesions in murine models for research purposes. This study focuses on the efficacy of using IMQ to induce a psoriasis-like model on murine skin cells by analyzing single-cell RNA sequencing and trajectory analysis. The results indicate a few differences between IMQ-induced and control murine cells, primarily the increased keratinocyte and immune cell populations, which reflects the cell identity found on psoriatic skin. However, trajectory analysis reveals that IMQ-induced cells have quite a linear differentiation pattern compared to the branched pattern found in control cells. As a result, further research must be conducted to explore differing factors between psoriatic cells and IMQ-induced cells to determine its usefulness in mimicking psoriasis-like conditions for research.

Expression and function of VISTA on myeloid cells

V-domain containing Ig Suppressor of T cell Activation (VISTA) is predominantly expressed on myeloid cells and functions as a ligand/receptor/soluble molecule. In inflammatory responses and immune responses, VISTA regulates multiple functions of myeloid cells, such as chemotaxis, phagocytosis, T cell activation. Since inflammation and immune responses are critical in many diseases, VISTA is a promising therapeutic target. In this review, we will describe the expression and function of VISTA on different myeloid cells, including neutrophils, monocytes, macrophages, dendritic cells (DCs), myeloid-derived suppressor cells (MDSCs). In addition, we will discuss whether the functions of VISTA on these cells impact the disease processing.

The role of dermal fibroblasts in autoimmune skin diseases

Fibroblasts are an important subset of mesenchymal cells in maintaining skin homeostasis and resisting harmful stimuli. Meanwhile, fibroblasts modulate immune cell function by secreting cytokines, thereby implicating their involvement in various dermatological conditions such as psoriasis, vitiligo, and atopic dermatitis. Recently, variations in the subtypes of fibroblasts and their expression profiles have been identified in these prevalent autoimmune skin diseases, implying that fibroblasts may exhibit distinct functionalities across different diseases. In this review, from the perspective of their fundamental functions and remarkable heterogeneity, we have comprehensively collected evidence on the role of fibroblasts and their distinct subpopulations in psoriasis, vitiligo, atopic dermatitis, and scleroderma. Importantly, these findings hold promise for guiding future research directions and identifying novel therapeutic targets for treating these diseases.

Single-cell RNA-seq reveals keratinocyte and fibroblast heterogeneity and their crosstalk via epithelial-mesenchymal transition in psoriasis

The pathogenesis of psoriasis, a chronic inflammatory autoimmune skin disease with a high global prevalence, remains unclear. We performed a high-resolution single-cell RNA sequencing analysis of 94,759 cells from 13 samples, including those from psoriasis model mice and wild-type mice. We presented a single-cell atlas of the skin of imiquimod-induced mice with psoriasis and WT mice, especially the heterogeneity of keratinocytes and fibroblasts. More interestingly, we discovered that special keratinocyte subtypes and fibroblast subtypes could interact with each other through epithelial-mesenchymal transition and validated the results with drug verification. Moreover, we conducted a tentative exploration of the potential pathways involved and revealed that the IL-17 signalling pathway may be the most relevant pathway. Collectively, we revealed the full-cycle landscape of key cells associated with psoriasis and provided a more comprehensive understanding of the pathogenesis of psoriasis.

Cosentyx alleviates psoriasis-induced podocyte injury by inhibiting the tlr/nf-κb signaling pathway

BACKGROUND

Pathological studies have shown an association between psoriasis and renal podocyte injury, and the specific mechanism of podocyte injury in psoriasis remains unclear, with no effective treatments currently available. This study aimed to investigate the underlying mechanisms of podocyte and epidermal cell injury in psoriasis and evaluate the therapeutic effect of Cosentyx.

MATERIALS AND METHODS

A psoriasis-like mouse model was established using BALB/C mice, and Cosentyx treatment was administered via intraperitoneal injection. Various parameters, including skin lesions, urinary protein, kidney/serum inflammatory cytokines, kidney function, podocyte membrane proteins, and Toll-like receptors/nuclear factor kappa-b (TLR/NF-κB) pathway-associated proteins, were analyzed to explore the mechanisms of podocyte and epidermal cell injury in psoriasis and the potential ameliorative effects of Cosentyx.

RESULT

Treatment with Cosentyx significantly reduced the increased levels of urinary protein, creatinine, and blood urea nitrogen caused by psoriasis. Cosentyx inhibited the upregulation of kidney/serum inflammatory factors (IL-17, IL-1β, IL-6, TNF-α, and IL-22) and TLR/NF-κB-related proteins (TLR2, TLR4, MyD88, and NF-κBp65) in both psoriatic skin and kidney tissues, while also reducing the accumulation of oxidative products. Moreover, Cosentyx treatment suppressed podocyte apoptosis and promoted epidermal cell apoptosis. The experimental data demonstrated that psoriasis-like inflammation impaired renal podocytes through the TLR/NF-κB signaling pathway.

CONCLUSION

Cosentyx treatment effectively inhibited the expression of TLR/NF-κB-related proteins, providing a therapeutic effect for psoriasis-induced kidney and skin injuries.

Integrated analysis of multiple metabolome and transcriptome revealed the accumulation of flavonoids and associated molecular regulation mechanisms in Rubus chingii Hu at different developmental stages

The traditional Chinese herb Rubus chingii Hu (R. chingii) is widely used in clinical practice due to its beneficial effects. Flavonoids are the important class of pharmacological substances in R. chingii, however, the molecular mechanism underlying the differences in active flavonoid contents in R. chingii at different developmental stages remain poorly understood. In this experiment, we selected four developmental stages (GG, GY, YR, RR) of R. chingii as the research material. We studied the untargeted and targeted metabolic profiles of flavonoids in different periods of R. chingii, combining full-length and comparative transcriptome analyses. Functional analyses were conducted on genes implicated in flavonoid differences. GG and RR displayed relatively higher and lower contents of flavonols, flavones, flavanols, flavanones, and isoflavonoid, respectively. RNA-seq analyses showed structural genes such as RcPAL, RcC4H, Rc4CL, RcCHS, RcCHI, RcF3H, RcF3'H, and RcFLS in flavonoid biosynthesis pathway were upregulated in GG, which were essential for the accumulation flavanones, flavones, and flavonols (effective components). qRT-PCR analyses investigated that six structural genes RcCHI, RcF3H, 2 RcCHS, and 2 Rc4CL, two TFs RcMYB308 and RcMYB123 had a consistent expression pattern with which in transcriptome. Also, an interaction network showed that the RcMYB308 could positively regulate Ka3R, Qu, Qu3G, AS, Hy, Ti through RcF3H. Furthermore, Subcellular localization analysis revealed that RcMYB308 was localization to the nucleus. In tobacco, RcMYB308 was overexpressed, resulting in higher flavonoids, RcF3H, RcF3'H, RcCHI, and RcFLS. RcMYB308 upregulated RcF3H in dual-luciferase assays. These results provide new insights for further understanding the molecular mechanism regulating flavonol biosynthesis in R. chingii fruit, and also provide a potential MYB regulator for molecular breeding of R. chingii.

Keratinocyte derived HMGB1 aggravates psoriasis dermatitis via facilitating inflammatory polarization of macrophages and hyperproliferation of keratinocyte

Psoriasis is one of the most common immune-mediated chronic inflammatory skin diseases, involving excessive proliferation of keratinocyte and infiltration of immune cells. There are many factors that cause the onset of psoriasis, so the exact pathogenesis of psoriasis still needs to be determined. High mobility group box-1 (HMGB1), a pro-inflammatory cytokine, is closely related to the pathogenesis of various inflammatory diseases. However, there are few studies investigating the effects of HMGB1 on inflammatory dermatoses. Here, we found that keratinocyte in the the IMQ-treated skin lesions of psoriasis model mice expressed more HMGB1. Notably, HMGB1 produced by keratinocyte could promote the activation of inflammatory type macrophages without affecting the polarization of anti-inflammatory type macrophages. Meanwhile, the proportion of M1 type macrophages in the skin lesions is significantly increased. Moreover, local clearance of macrophages in the skin could alleviate psoriasis like inflammation. Finally, keratinocyte-derived HMGB1 could also act on itself in turn, promoting the excessive proliferation and the mRNA expression of inflammatory cytokines of keratinocyte. Therefore, this study not only found the effect of HMGB1 on the hyperproliferation of keratinocyte, but also revealed that keratinocyte could communicate with macrophages through HMGB1, thereby facilitating macrophage inflammatory polarization. Collectively, these findings have clinical significance for the research and treatment of psoriasis, HMGB1 may become a potential target for the treatment of psoriasis.

A single-cell atlas of immunocytes in the spleen of a mouse model of Wiskott-Aldrich syndrome

Wiskott-Aldrich syndrome (WAS) is a disorder characterized by rare X-linked genetic immune deficiency with mutations in the Was gene, which is specifically expressed in hematopoietic cells. The spleen plays a major role in hematopoiesis and red blood cell clearance. However, to date, comprehensive analyses of the spleen in wild-type (WT) and WASp-deficient (WAS-KO) mice, especially at the transcriptome level, have not been reported. In this study, single-cell RNA sequencing (scRNA-seq) was adopted to identify various types of immune cells and investigate the mechanisms underlying immune deficiency. We identified 30 clusters and 10 major cell subtypes among 11,269 cells; these cell types included B cells, T cells, dendritic cells (DCs), natural killer (NK) cells, monocytes, macrophages, granulocytes, stem cells and erythrocytes. Moreover, we evaluated gene expression differences among cell subtypes, identified differentially expressed genes (DEGs), and performed enrichment analyses to identify the reasons for the dysfunction in these different cell populations in WAS. Furthermore, some key genes were identified based on a comparison of the DEGs in each cell type involved in specific and nonspecific immune responses, and further analysis showed that these key genes were previously undiscovered pathology-related genes in WAS-KO mice. In summary, we present a landscape of immune cells in the spleen of WAS-KO mice based on detailed data obtained at single-cell resolution. These unprecedented data revealed the transcriptional characteristics of specific and nonspecific immune cells, and the key genes were identified, laying a foundation for future studies of WAS, especially studies into novel and underexplored mechanisms that may improve gene therapies for WAS.

Forward genetics and functional analysis highlight Itga11 as a modulator of murine psoriasiform dermatitis

Psoriasis is a chronic inflammatory skin condition. Repeated epicutaneous application of Aldara® (imiquimod) cream results in psoriasiform dermatitis in mice. The Aldara®-induced psoriasiform dermatitis (AIPD) mouse model has been used to examine the pathogenesis of psoriasis. Here, we used a forward genetics approach in which we compared AIPD that developed in 13 different inbred mouse strains to identify genes and pathways that modulated disease severity. Among our primary results, we found that the severity of AIPD differed substantially between different strains of inbred mice and that these variations were associated with polymorphisms in Itga11. The Itga11 gene encodes the integrin α11 subunit that heterodimerizes with the integrin β1 subunit to form integrin α11β1. Less information is available about the function of ITGA11 in skin inflammation; however, a role in the regulation of cutaneous wound healing, specifically the development of dermal fibrosis, has been described. Experiments performed with Itga11 gene-deleted (Itga11-/- ) mice revealed that the integrin α11 subunit contributes substantially to the clinical phenotype as well as the histopathological and molecular findings associated with skin inflammation characteristic of AIPD. Although the skin transcriptomes of Itga11-/- and WT mice do not differ from one another under physiological conditions, distinct transcriptomes emerge in these strains in response to the induction of AIPD. Most of the differentially expressed genes contributed to extracellular matrix organization, immune system, and metabolism of lipids pathways. Consistent with these findings, we detected a reduced number of fibroblasts and inflammatory cells, including macrophages, T cells, and tissue-resident memory T cells in skin samples from Itga11-/- mice in response to AIPD induction. Collectively, our results reveal that Itga11 plays a critical role in promoting skin inflammation in AIPD and thus might be targeted for the development of novel therapeutics for psoriasiform skin conditions. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Li-Mg-Si bioceramics provide a dynamic immuno-modulatory and repair-supportive microenvironment for peripheral nerve regeneration

Biomaterials can modulate the local immune and repair-supportive microenvironments to promote peripheral nerve regeneration. Inorganic bioceramics have been widely used for regulating tissue regeneration and local immune response. However, little is known on whether inorganic bioceramics can have potential for enhancing peripheral nerve regeneration and what are the mechanisms underlying their actions. Here, the inorganic lithium-magnesium-silicon (Li-Mg-Si, LMS) bioceramics containing scaffolds are fabricated and characterized. The LMS-containing scaffolds had no cytotoxicity against rat Schwann cells (SCs), but promoted their migration and differentiation towards a remyelination state by up-regulating the expression of neurotrophic factors in a β-catenin-dependent manner. Furthermore, using single cell-sequencing, we showed that LMS-containing scaffolds promoted macrophage polarization towards the pro-regenerative M2-like cells, which subsequently facilitated the migration and differentiation of SCs. Moreover, implantation with the LMS-containing nerve guidance conduits (NGCs) increased the frequency of M2-like macrophage infiltration and enhanced nerve regeneration and motor functional recovery in a rat model of sciatic nerve injury. Collectively, these findings indicated that the inorganic LMS bioceramics offered a potential strategy for enhancing peripheral nerve regeneration by modulating the immune microenvironment and promoting SCs remyelination.

New insight into the role of fibroblasts in the epithelial immune microenvironment in the single-cell era

The skin is exposed to environmental challenges and contains heterogeneous cell populations such as epithelial cells, stromal cells, and skin-resident immune cells. As the most abundant type of stromal cells, fibroblasts have been historically considered silent observers in the immune responses of the cutaneous epithelial immune microenvironment (EIME), with little research conducted on their heterogeneity and immune-related functions. Single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics (ST) have overcome the limitations of bulk RNA sequencing and help recognize the functional and spatial heterogeneity of fibroblasts, as well as their crosstalk with other types of cells in the cutaneous EIME. Recently, emerging single-cell sequencing data have demonstrated that fibroblasts notably participate in the immune responses of the EIME and impact the initiation and progression of inflammatory skin diseases. Here, we summarize the latest advances in the role of fibroblasts in the cutaneous EIME of inflammatory skin diseases and discuss the distinct functions and molecular mechanisms of activated fibroblasts in fibrotic skin diseases and non-fibrotic inflammatory skin diseases. This review help unveil the multiple roles of fibroblasts in the cutaneous EIME and offer new promising therapeutic strategies for the management of inflammatory skin diseases by targeting fibroblasts or the fibroblast-centered EIME.

Neuroprotective effect of Astragali Radix on cerebral infarction based on proteomics

Objective: Astragali Radix (AR, Huangqi in Chinese) has a neuroprotective effect on cerebral infarction (CI). In order to explore the biological basis and therapeutic mechanism of AR in CI, a double-blind randomized controlled trial was established in this study, and proteomics analysis was carried out on serum samples of patients. Methods: The patients were divided into the AR group (n = 35) and the control group (n = 30). The curative effect was evaluated by the traditional Chinese medicine (TCM) syndrome score and clinical indicators, and the serum of the two groups was analyzed by proteomics. Based on bioinformatics analysis methods, the changes in differential proteins between two groups of samples were explored, and the key proteins were validated through enzyme-linked immunosorbent assay (ELISA). Results: The results of this study showed that the scores of deficiency of vital energy (DVE), blood stasis (BS), and NIH Stroke Scale (NIHSS) decreased significantly (p < 0.05), while the scores of the Barthel Index (BI) increased, indicating that AR could significantly improve the symptoms of CI patients. In addition, we found that compared with the control group, AR upregulated 43 proteins and downregulated 20 proteins, especially focusing on anti-atherosclerosis and neuroprotective effects. Moreover, ELISA indicated the levels of IL-6, TNF-α, VCAM-1, MCP-1, and ICAM-1 were significantly decreased in the serum of the AR group (p < 0.05, p < 0.01). Conclusion: This study found that AR can significantly recover the clinical symptoms of CI. Serum proteomics research results show that AR may act on IL-6, TNF-α, VCAM-1, MCP-1, and ICAM-1, and play anti-atherosclerosis and neuroprotective roles. Clinical Trial Registration: [clinicaltrials.gov], identifier [NCT02846207].

Multi-Omics Research Strategies for Psoriasis and Atopic Dermatitis

Psoriasis and atopic dermatitis (AD) are multifactorial and heterogeneous inflammatory skin diseases, while years of research have yielded no cure, and the costs associated with caring for people suffering from psoriasis and AD are a huge burden on society. Integrating several omics datasets will enable coordinate-based simultaneous analysis of hundreds of genes, RNAs, chromatins, proteins, and metabolites in particular cells, revealing networks of links between various molecular levels. In this review, we discuss the latest developments in the fields of genomes, transcriptomics, proteomics, and metabolomics and discuss how they were used to identify biomarkers and understand the main pathogenic mechanisms underlying these diseases. Finally, we outline strategies for achieving multi-omics integration and how integrative omics and systems biology can advance our knowledge of, and ability to treat, psoriasis and AD.

To explore the regulatory effect of Buyang Huanwu Decoction on cerebral infarction based on quantitative proteomics

Buyang Huanwu Decoction (BYHW) contains chemical components such as ligustrazine, oxypaeoniflora, chlorogenic acid, and others. To explore the neuroprotective effect and potential target protein of BYHW in cerebral infarction (CI). A double-blind, randomized controlled trial was established and patients with CI were divided into the BYHW group (n = 35) and the control group (n = 30). To evaluate the efficacy by TCM syndrome score and clinical indicators, and to explore the changes of serum proteins by proteomics technology, so as to explore the mechanism of BYHW and potential target proteins. The study found that compared with the control group, the TCM syndrome score, including Deficiency of Vital Energy (DVE), Blood Stasis (BS), and NIHSS in the BYHW group decreased significantly (p < 0.05), and the Barthel Index (BI) score was significantly higher. A total of 99 differential regulatory proteins were identified by proteomics, which act on lipids and atherosclerosis, complement and coagulation cascade, and TNF-α signaling pathway. In addition, Elisa verified the results of proteomics and found that BYHW can reduce the neurological impairments focus on IL-1β, IL-6, TNF-α, MCP-1, MMP-9, and PAI-1. Significance: In this study, quantitative proteomics was used in combination with liquid chromatography-mass spectrometry (LC-MS/MS) to study the therapeutic effect of BYHW on cerebral infarction (CI) and potential changes in serum proteomics. In addition, the public proteomics database was used for bioinformatics analysis, and Elisa experiment verified the results of proteomics, further clarifying the potential protection mechanism of BYHW on CI.

Tenascin C+ papillary fibroblasts facilitate neuro-immune interaction in a mouse model of psoriasis

Dermal fibroblasts and cutaneous nerves are important players in skin diseases, while their reciprocal roles during skin inflammation have not been characterized. Here we identify an inflammation-induced subset of papillary fibroblasts that promotes aberrant neurite outgrowth and psoriasiform skin inflammation by secreting the extracellular matrix protein tenascin-C (TNC). Single-cell analysis of fibroblast lineages reveals a Tnc⁺ papillary fibroblast subset with pro-axonogenesis and neuro-regulation transcriptomic hallmarks. TNC overexpression in fibroblasts boosts neurite outgrowth in co-cultured neurons, while fibroblast-specific TNC ablation suppresses hyperinnervation and alleviates skin inflammation in male mice modeling psoriasis. Dermal γδT cells, the main producers of type 17 pathogenic cytokines, frequently contact nerve fibers in mouse psoriasiform lesions and are likely modulated by postsynaptic signals. Overall, our results highlight the role of an inflammation-responsive fibroblast subset in facilitating neuro-immune synapse formation and suggest potential avenues for future therapeutic research.

Phenotypic heterogeneity in psoriatic arthritis: towards tissue pathology-based therapy

Psoriatic arthritis (PsA) is a heterogeneous disease involving multiple potential tissue domains. Most outcome measures used so far in randomized clinical trials do not sufficiently reflect this domain heterogeneity. The concept that pathogenetic mechanisms might vary across tissues within a single disease, underpinning such phenotype diversity, could explain tissue-distinct levels of response to different therapies. In this Review, we discuss the tissue, cellular and molecular mechanisms that drive clinical heterogeneity in PsA phenotypes, and detail existing tissue-based research, including data generated using sophisticated interrogative technologies with single-cell precision. Finally, we discuss how these elements support the need for tissue-based therapy in PsA in the context of existing and new therapeutic modes of action, and the implications for future PsA trial outcomes and design.

Research progress of single-cell transcriptome sequencing in autoimmune diseases and autoinflammatory disease: A review

Autoimmunity refers to the phenomenon that the body's immune system produces antibodies or sensitized lymphocytes to its own tissues to cause an immune response. Immune disorders caused by autoimmunity can mediate autoimmune diseases. Autoimmune diseases have complicated pathogenesis due to the many types of cells involved, and the mechanism is still unclear. The emergence of single-cell research technology can solve the problem that ordinary transcriptome technology cannot be accurate to cell type. It provides unbiased results through independent analysis of cells in tissues and provides more mRNA information for identifying cell subpopulations, which provides a novel approach to study disruption of immune tolerance and disturbance of pro-inflammatory pathways on a cellular basis. It may fundamentally change the understanding of molecular pathways in the pathogenesis of autoimmune diseases and develop targeted drugs. Single-cell transcriptome sequencing (scRNA-seq) has been widely applied in autoimmune diseases, which provides a powerful tool for demonstrating the cellular heterogeneity of tissues involved in various immune inflammations, identifying pathogenic cell populations, and revealing the mechanism of disease occurrence and development. This review describes the principles of scRNA-seq, introduces common sequencing platforms and practical procedures, and focuses on the progress of scRNA-seq in 41 autoimmune diseases, which include 9 systemic autoimmune diseases and autoinflammatory diseases (rheumatoid arthritis, systemic lupus erythematosus, etc.) and 32 organ-specific autoimmune diseases (5 Skin diseases, 3 Nervous system diseases, 4 Eye diseases, 2 Respiratory system diseases, 2 Circulatory system diseases, 6 Liver, Gallbladder and Pancreas diseases, 2 Gastrointestinal system diseases, 3 Muscle, Bones and joint diseases, 3 Urinary system diseases, 2 Reproductive system diseases). This review also prospects the molecular mechanism targets of autoimmune diseases from the multi-molecular level and multi-dimensional analysis combined with single-cell multi-omics sequencing technology (such as scRNA-seq, Single cell ATAC-seq and single cell immune group library sequencing), which provides a reference for further exploring the pathogenesis and marker screening of autoimmune diseases and autoimmune inflammatory diseases in the future.

Caerin 1.1/1.9 Enhances Antitumour Immunity by Activating the IFN-α Response Signalling Pathway of Tumour Macrophages

Macrophages are one of the essential components of the tumour microenvironment (TME) of many cancers and show complex heterogeneity and functions. More recent research has been focusing on the characterisation of tumour-associated macrophages (TAMs). Previously, our study demonstrated that caerin 1.1/1.9 peptides significantly improve the therapeutic efficacy of combined specific immunotherapy and immune checkpoint blockade in a murine transplantable tumour model (TC-1). In this study, the mice inoculated with TC-1 tumour were immunised differently. The TAMs were isolated using flow cytometry and characterised by cytokine ELISA. The survival rates of mice with different treatments containing caerin 1.1/19 were assessed comparatively, including those with/without macrophage depletion. The single-cell RNA sequencing (scRNA-seq) data of previous studies were integrated to further reveal the functions of TAMs with the treatments containing caerin 1.1/1.9. As a comparison, the TAMs of stage I and II cervical cancer patients were analysed using scRNA-seq analysis. We demonstrate that caerin induced tumour clearance is associated with infiltration of tumours by IL-12 secreting Ly6C+F4/80+ macrophages exhibiting enhanced IFN-α response signalling, renders animals resistant to further tumour challenge, which is lost after macrophage depletion. Our results indicate that caerin 1.1/1.9 treatment has great potential in improving current immunotherapy efficacy.

Single-cell sequencing reveals the landscape of the tumor microenvironment in a skeletal undifferentiated pleomorphic sarcoma patient

Skeletal undifferentiated pleomorphic sarcoma (SUPS) is an invasive pleomorphic soft tissue sarcoma with a high degree of malignancy and poor prognosis. It is prone to recur and metastasize. The tumor microenvironment (TME) and the pathophysiology of SUPS are barely described. Single-cell RNA sequencing (scRNA-seq) provides an opportunity to dissect the landscape of human diseases at an unprecedented resolution, particularly in diseases lacking animal models, such as SUPS. We performed scRNA-seq to analyze tumor tissues and paracancer tissues from a SUPS patient. We identified the cell types and the corresponding marker genes in this SUPS case. We further showed that CD8+ exhausted T cells and Tregs highly expressed PDCD1, CTLA4 and TIGIT. Thus, PDCD1, CTLA4 and TIGIT were identified as potential targets in this case. We applied copy number karyotyping of aneuploid tumors (CopyKAT) to distinguish malignant cells from normal cells in fibroblasts. Our study identified eight malignant fibroblast subsets in SUPS with distinct gene expression profiles. C1-malignant Fibroblast and C6-malignant Fibroblast in the TME play crucial roles in tumor growth, angiogenesis, metastasis and immune response. Hence, targeting malignant fibroblasts could represent a potential strategy for this SUPS therapy. Intervention via tirelizumab enabled disease control, and immune checkpoint inhibitors (ICIs) of PD-1 may be considered as the first-line option in patients with SUPS. Taken together, scRNA-seq analyses provided a powerful basis for this SUPS treatment, improved our understanding of complex human diseases, and may afforded an alternative approach for personalized medicine in the future.

Acute and chronic inflammation alter immunometabolism in a cutaneous delayed-type hypersensitivity reaction (DTHR) mouse model

T-cell-driven immune responses are responsible for several autoimmune disorders, such as psoriasis vulgaris and rheumatoid arthritis. Identification of metabolic signatures in inflamed tissues is needed to facilitate novel and individualised therapeutic developments. Here we show the temporal metabolic dynamics of T-cell-driven inflammation characterised by nuclear magnetic resonance spectroscopy-based metabolomics, histopathology and immunohistochemistry in acute and chronic cutaneous delayed-type hypersensitivity reaction (DTHR). During acute DTHR, an increase in glutathione and glutathione disulfide is consistent with the ear swelling response and degree of neutrophilic infiltration, while taurine and ascorbate dominate the chronic phase, suggesting a switch in redox metabolism. Lowered amino acids, an increase in cell membrane repair-related metabolites and infiltration of T cells and macrophages further characterise chronic DTHR. Acute and chronic cutaneous DTHR can be distinguished by characteristic metabolic patterns associated with individual inflammatory pathways providing knowledge that will aid target discovery of specialised therapeutics.

Nuclear magnetic resonance spectroscopy-based tissue metabolomics is used to define detailed temporal signatures of acute and chronic inflammation in cutaneous delayed-type hypersensitivity reaction.

Single-Cell RNA Sequencing Reveals the Immune Cell Profiling in IMQ Induced Psoriasis-Like Model

PURPOSE

Psoriasis is a chronic systemic inflammatory skin disease with a high recurrence rate. The immune response plays an important role in psoriasis. However, the subsets of immune cells involved in inflammation in psoriatic mice have not been fully studied. This study showed the immune environment characteristics of psoriasis in mice.

METHODS

We used single-cell RNA sequencing (10× Genomics) as an unbiased analytical strategy to investigate the heterogeneity of skin immune cells in imiquimod-induced psoriasis mice systematically.

RESULTS

We identified 10 major clusters and their marker genes among 14,439 cells. The proportions of macrophages, NK/T cells, conventional dendritic cells (cDCs) and plasmacytoid dendritic cells (pDCs) were increased in psoriatic mice. Macrophages were the largest group and were further divided into 7 subgroups, and all macrophage clusters were increased in psoriatic mice. Differentially expressed genes in control versus psoriatic mice skin lesions showed that Fcgr4, Saa3 and Acp5 in macrophages, Acp5, Fcgr4 and Ms4a6d in NK/T cells, Saa3 in cDCs, and Ifitm1 in pDCs were upregulated in psoriasis mice. Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway enrichment analysis emphasized the role of oxidative phosphorylation signals and antigen processing and presentation signals in murine psoriasis-like models.

CONCLUSION

Our study reveals the immune environment characteristics of the commonly used IMQ induced psoriasis-like models and provides a systematic insight into the immune response of mice with psoriasis, which is conducive to comparing the similarities and differences between the mouse model and human psoriasis.

CEBPB is associated with active tumor immune environment and favorable prognosis of metastatic skin cutaneous melanoma

Metastatic skin cutaneous melanoma (SKCM) is a common malignancy that accounts for low morbidity but high mortality of skin cancer. SKCM is characterized by high lymphocytic infiltration, whereas the states of infiltrated cells are variable in patients leading to a heterogeneous prognosis and hindering appropriate clinical decisions. It is therefore urgent to identify markers associated with lymphocytic infiltration, cellular conditions, and the prognosis of SKCM. In this study, we report that CEBPB, a transcriptional factor, is mainly expressed in macrophages in metastatic SKCM and associated with an active tumor immune environment and a favorable prognosis through integrated analysis of single-cell and bulk RNA-seq datasets. High CEBPB expression is significantly associated with active inflammation and immune response pathways in both macrophages and bulk SKCM tumor tissues. A signature based on CEBPB-associated genes that are specifically expressed in macrophages could robustly and prognostically separate different metastatic SKCM patients. In addition, the associations between the metastatic SKCM tumor signature and microenvironment with respect to T-cell recruitment and state, inflammation response, angiogenesis, and so on were also determined. In conclusion, we present here the first report on CEBPB in tumor immune environment and prognosis regulation in metastatic SKCM and construct a reliable signature, which should provide a useful biomarker for stratification of the patient's prognosis and therapeutic selection.

A chromosome-level genome assembly provides insights into the environmental adaptability and outbreaks of Chlorops oryzae

Chlorops oryzae is a pest of rice that has caused severe damage to crops in major rice-growing areas in recent years. We generated a 447.60 Mb high-quality chromosome-level genome with contig and scaffold N50 values of 1.17 Mb and 117.57 Mb, respectively. Hi-C analysis anchored 93.22% scaffolds to 4 chromosomes. The relatively high expression level of Heat Shock Proteins (HSPs) and antioxidant genes in response to thermal stress suggests these genes may play a role in the environmental adaptability of C. oryzae. The identification of multiple pathways that regulate reproductive development (juvenile hormone, 20-hydroxyecdsone, and insulin signaling pathways) provides evidence that these pathways also play an important role in vitellogenesis and thus insect population maintenance. These findings identify possible reasons for the increased frequency of outbreaks of C. oryzae in recent years. Our chromosome-level genome assembly may provide a basis for further genetic studies of C. oryzae, and promote the development of novel, sustainable strategies to control this pest.

A chromosome-level genome assembly for the rice pest, Chlorops oryzae, pinpoints molecular pathways that might contribute toward increased outbreaks for this important crop pest.

Identify the Prognostic and Immune Profile of VSIR in the Tumor Microenvironment: A Pan-Cancer Analysis

VSIR is a critical immunomodulatory receptor that inhibits T cell effector function and maintains peripheral tolerance. However, the mechanism by which VSIR participates in tumor immunity in the pan-cancer tumor microenvironment remains unclear. This study systematically explored the prognostic and immune profile of VSIR in the tumor microenvironment of 33 cancers. We compared the expression patterns and molecular features of VSIR in the normal and cancer samples both from the public databases and tumor chips. VSIR level was significantly related to patients’ prognosis and could be a promising predictor in many tumor types, such as GBM, KIRC, SKCM, READ, and PRAD. Elevated VSIR was closely correlated with infiltrated inflammatory cells, neoantigens expression, MSI, TMB, and classical immune checkpoints in the tumor microenvironment. Enrichment signaling pathways analysis indicated VSIR was involved in several immune-related pathways such as activation, proliferation, and migration of fibroblast, T cell, mast cell, macrophages, and foam cell. In addition, VSIR was found to widely express on cancer cells, fibroblasts, macrophages, and T cells in many tumor types based on the single-cell sequencing analysis and co-express with M2 macrophage markers CD68, CD163 based on the immunofluorescence staining. Finally, we predicted the sensitive drugs targeting VSIR and the immunotherapeutic value of VSIR. In sum, VSIR levels strongly correlated with the clinical outcome and tumor immunity in multiple cancer types. Therefore, therapeutic strategies targeting VSIR in the tumor microenvironment may be valuable tools for cancer immunotherapy.

Efficacy and Mechanism of Buyang Huanwu Decoction in Patients With Ischemic Heart Failure: A Randomized, Double-Blind, Placebo-Controlled Trial Combined With Proteomic Analysis

Objective: Buyang Huanwu Decoction (BYHW), a famous herbal prescription in traditional Chinese medicine (TCM), has been used for 200 years for treating ischemic heart failure (IHF). This study aims to assess the efficacy and safety of BYHW combined with guideline-guided pharmacotherapy in patients with IHF and explore the biological mechanism by which BYHW exerts its efficacy. Methods: In the multicenter, double-blind, randomized controlled trial, a total of 80 patients with IHF were randomized to receive BYHW or placebo for 3 months. The primary efficacy endpoints were New York Heart Association (NYHA) classification, TCM syndrome scores, N-terminal pro-B-type natriuretic peptide (NT-ProBNP), whereas the mechanism exploration endpoints included energy metabolism parameters and coagulation function parameters. In addition, we performed the proteomic study of the serum of patients after treatment by label-free quantification technology to verify the candidate target proteins and pathways. Results: After 3 months of treatment, the NYHA classification, TCM syndrome scores, and the percentage of subjects with at least 30% reduction in NT-ProBNP were significantly improved in the BYHW group, compared with the control group (p < 0.05); BYHW treatment also significantly regulated blood glucose, blood lipid levels, ameliorated energy metabolism and improved coagulation function parameters. There were no significant differences in safety endpoints between the two groups. In addition, we obtained 56 differentially expressed proteins by proteomics, including 20 upregulated proteins and 36 downregulated proteins. Bioinformatic analysis revealed the mechanism of BYHW treatment was significantly related to complement and coagulation cascades, cholesterol metabolism, NF-kappa B signaling pathway, PI3K-Akt signaling pathway, and metabolic pathways. Among these differentially regulated proteins, fibrinogen gamma (FGG), fibrinogen beta (FGB), Carboxypeptidase B2 (CPB2), Coagulation factor XIII A (F13A1), Intercellular adhesion molecule1 (ICAM1), Apolipoprotein C-II(APOC2), Apolipoprotein C-I(APOC1), and CD44 were found to be signature proteins associated with the efficacy of BYHW against IHF. Conclusion: BYHW treatment can further improve cardiac dysfunction and clinical symptoms in IHF based on standard therapy without apparent adverse effects. Additionally, BYHW may play a therapeutic role in IHF by improving energy metabolism and regulating coagulation function through multiple targets and pathways.

Salubrinal protects against inflammatory response in macrophage and attenuates psoriasiform skin inflammation by antagonizing NF-κB signaling pathway

Psoriasiform skin inflammation is the common chronic skin inflammatory disease with no effective clinical therapy. Salubrinal is a multifunctional molecule playing a protective role in several conditions. Recently, studies have reported that Salubrinal is a potential therapeutic agent for inflammatory diseases. However, the protective role of Salubrinal in psoriasis-like skin inflammation remains unknown. In this article, imiquimod (IMQ)-induced psoriasis models were established in wild-type mice to explore the role of Salubrinal in the development of psoriasis. As a result, the IMQ-induced mouse models exhibited typical skin inflammation, which was alleviated by the administration of Salubrinal. Furthermore, RAW264.7 macrophage was stimulated with Lipopolysaccharide(LPS) in the presence or absence of Salubrinal. LPS stimulation elevated the expression of various inflammatory biomarkers, while the administration of Salubrinal abolished the function of LPS in RAW264.7 macrophages. In addition, the activation of the nuclear factor-kappa B (NF-κB) signaling pathway in both the LPS-stimulated RAW264.7 macrophage and psoriasis mouse models was antagonized by the administration of Salubrinal. Collectively, Salubrinal might be considered as a promising therapeutic agent for psoriasis-like skin inflammation.

Analytical approaches to assess metabolic changes in psoriasis

Psoriasis is one of the most common human skin diseases, although its development is not limited to one tissue, but is associated with autoimmune reactions throughout the body. Overproduction of pro-inflammatory cytokines and growth factors systemically stimulates the proliferation of skin cells, which manifests as excessive exfoliation of the epidermis, and/or arthritis, as well as other comorbidities such as insulin resistance, metabolic syndrome, hypertension, and depression. Thus, there is a great need for a thorough analysis of the pathophysiology of psoriatic patients, including classical methods, such as spectrophotometry, chromatography, or Western blot, and also novel omics approaches such as lipidomics and proteomics. Moreover, the extensive pathophysiology forces increased research examining biological changes in both skin cells, and systemically. A wide range of techniques involved in lipidomic research based on a combination of mass spectrometry and different types of chromatography (RP-LC-QTOF-MS/MS, HILIC-QTOF-MS/MS or RP-LC-QTRAP-MS/MS), have allowed comprehensive assessment of lipid modification in psoriatic skin and provided new insight into the role of lipids and their mechanism of action in psoriasis. Moreover, proteomic analysis using gel-nanoLC-OrbiTrap-MS/MS, as well as MALDI-TOF/TOF techniques facilitates the description of panels of enzymes involved in lipidome modifications, and the response of the endocannabinoid system to metabolic changes. Psoriasis is known to alter the expression of proteins that are involved in the inflammatory and antioxidant response, as well as protein biosynthesis, degradation, as well as cell proliferation and apoptosis. Knowledge of changes in the lipidomic and proteomic profile will not only allow the understanding of psoriasis pathophysiology, but also facilitate proper and early diagnosis and effective pharmacotherapy.

Single cell transcriptional zonation of human psoriasis skin identifies an alternative immunoregulatory axis conducted by skin resident cells

Psoriasis is the most common skin disease in adults. Current experimental and clinical evidences suggested the infiltrating immune cells could target local skin cells and thus induce psoriatic phenotype. However, recent studies indicated the existence of a potential feedback signaling loop from local resident skin cells to infiltrating immune cells. Here, we deconstructed the full-thickness human skins of both healthy donors and patients with psoriasis vulgaris at single cell transcriptional level, and further built a neural-network classifier to evaluate the evolutional conservation of skin cell types between mouse and human. Last, we systematically evaluated the intrinsic and intercellular molecular alterations of each cell type between healthy and psoriatic skin. Cross-checking with psoriasis susceptibility gene loci, cell-type based differential expression, and ligand-receptor communication revealed that the resident psoriatic skin cells including mesenchymal and epidermis cell types, which specifically harbored the target genes of psoriasis susceptibility loci, intensively evoked the expression of major histocompatibility complex (MHC) genes, upregulated interferon (INF), tumor necrosis factor (TNF) signalling and increased cytokine gene expression for primarily aiming the neighboring dendritic cells in psoriasis. The comprehensive exploration and pathological observation of psoriasis patient biopsies proposed an uncovered immunoregulatory axis from skin local resident cells to immune cells, thus provided a novel insight for psoriasis treatment. In addition, we published a user-friendly website to exhibit the transcriptional change of each cell type between healthy and psoriatic human skin.

M351-0056 is a novel low MW compound modulating the actions of the immune-checkpoint protein VISTA

Background and Purpose

The protein V‐domain immunoglobulin suppressor of T‐cell activation (VISTA) is a novel immune‐checkpoint molecule that belongs to the B7 family and regulates a broad spectrum of immune responses. So far, low MW compounds targeting VISTA for the treatment of autoimmune diseases or inflammation, have not been identified.

Experimental Approach

We developed a homology modelling for VISTA 3D structure and subsequent virtual screening for low MW ligands binding to VISTA. Visualization of the binding postures of docked ligands with protein VISTA indicated that compound M351‐0056 targeted VISTA. The biological activities of compound M351‐0056 targeting VISTA were investigated in vitro using monocytes and T cells and in vivo, using mice with imiquimod‐induced dermatitis.

Key Results

The K_D value of M351‐0056 for human VISTA‐extracellular domain was 12.60 ± 3.84 μM as assessed by microscale thermophoresis. M351‐0056 decreased cytokine secretion from PBMCs or human CD4⁺ T cells, suppressed proliferation of PBMCs and enhanced expression of Foxp3⁺ T cells. These effects of M351‐0056 modulating VISTA involved the JAK2–STAT2 pathway. Daily administration of M351‐0056 ameliorated imiquimod‐induced psoriasis‐like dermatitis. Expression of mRNA and protein of inflammatory cytokines in psoriatic lesions was decreased after M351‐0056 treatment.

Conclusion and Implications

The compound M351‐0056 showed high affinity for VISTA and may modulate its immune function in vitro and in vivo. Our finding provides a lead compound for therapeutically enhancing VISTA‐mediated pathways to benefit the treatment of autoimmune diseases or inflammation.