ANGPTL4 Regulates Psoriasis via Modulating Hyperproliferation and Inflammation of Keratinocytes

Identification of memory mechanism in tissue-resident stem cells via ANGPTL4 beyond immune cells upon viral antigen exposure

Although memory functions of immune cells characterized by increased resistance to subsequent infections after initial pathogen exposure are well-established, it remains unclear whether non-immune cells, especially tissue-resident stem cells, exhibit similar memory mechanisms. The present study revealed that detrimental effects of initial viral antigen exposure (human papillomavirus [HPV]) on diverse stem cell functions were significantly exacerbated upon subsequent secondary exposure both in vitro and in vivo. Importantly, endometrial stem cells exhibited robust memory functions following consecutive HPV antigen exposures, whereas fully differentiated cells such as fibroblasts and vesicular cells did not show corresponding changes in response to the same antigen exposures. Deficiency of angiopoietin-like 4 (ANGPTL4) achieved through small hairpin RNA knockdown in vitro and knockout (KO) mice in vivo highlighted the critical role of ANGPTL4 in governing memory functions associated with various stem cell processes. This regulation occurred through histone H3 methylation alterations and PI3K/Akt signaling pathways in response to successive HPV antigen exposures. Furthermore, memory functions associated with various stem cell functions that were evident in wild-type mice following consecutive exposures to HPV antigen were not observed in ANGPTL4 KO mice. In summary, our findings strongly support the presence of memory mechanism in non-immune cells, particularly tissue-resident stem cells.

Exploring Memory Function Beyond Immune Cells: ANGPTL4-Mediated Memory Functions in Tissue Resident Stem Cells

Adapted immune cells are known to develop memory functions that increase resistance to subsequent infections after initial pathogen exposure, however, it is unclear whether non-immune cells, like tissue-resident stem cells, have similar memory functions. Here, it is found that tissue-resident stem cells crucial for tissue regeneration show diminished adverse effects on diverse stem cell functions against successive exposure to foreign antigen (β-glucan) to maintain tissue homeostasis and stability both in vitro and in vivo. These data suggest that endometrial stem cells may possess a robust memory function, in contrast, fully differentiated cells like fibroblasts and vesicular cells do not show these memory mechanisms upon consecutive antigen exposure. Moreover, the pivotal role of Angiopoietin-like 4 (ANGPTL4) in regulating the memory functions of endometrial stem cells is identified through specific shRNA knockdown in vitro and knockout mice in vivo experiments. ANGPTL4 is associated with the alteration of diverse stem cell functions and epigenetic modifications, notably through histone H3 methylation changes and two pathways (i.e., PI3K/Akt and FAK/ERK1/2 signaling) upon consecutive antigen exposure. These findings imply the existence of inherent self-defense mechanisms through which local stem cells can adapt and protect themselves from recurrent antigenic challenges, ultimately mitigating adverse consequences.

SPRR1B is Related to the Immune Microenvironment and Can Be Used as a Biomarker for the Diagnosis of Psoriasis

Background

Psoriasis, a chronic inflammatory disorder with an unknown cause, significantly impacts the physical and psychological well-being of patients. However, current biomarkers related to psoriasis lack clinical specificity, sensitivity, and predictive ability.

Methods

In this study, we collected skin lesion tissues from 20 psoriasis patients and 20 normal skin samples. Additionally, we obtained four datasets from the GEO database, which included human psoriasis and healthy specimens. We utilized SVM-RFE analysis and the LASSO regression model to identify potential biomarkers. Furthermore, we examined the composition of immune cell types in psoriasis and their correlation with specific genes.

Results

Our investigation revealed 57 differentially expressed genes (DEGs), and we identified significantly enriched pathways through KEGG pathway analysis. The results of machine learning and WGCNA suggested that LCE3D and SPRR1B could potentially be used as marker genes for diagnosing psoriasis. RT-PCR and immunohistochemical detection confirmed the abnormally high expression of the SPRR1B gene in psoriasis. Analysis of immune cell infiltration revealed a strong positive correlation between SPRR1B and Macrophages M0 and T cells follicular helper, while showing the strongest negative correlation with resting Mast cells. In addition, we found that silencing SPRR1B in IFN-γ-treated HaCat cells could significantly reduce the increase in IL-17, IL-22, KRT6, and KRT16 caused by IFN-γ.

Conclusion

These findings suggest that SPRR1B may have a significant role in the pathogenesis of psoriasis and could be employed as a novel immunomarker for its development.

A Route for Investigating Psoriasis: From the Perspective of the Pathological Mechanisms and Therapeutic Strategies of Cancer

Psoriasis is an incurable skin disease that develops in about two-thirds of patients before the age of 40 and requires lifelong treatment; its pathological mechanisms have not been fully elucidated. The core pathological process of psoriasis is epidermal thickening caused by the excessive proliferation of epidermal keratinocytes, which is similar to the key feature of cancer; the malignant proliferation of cancer cells causes tumor enlargement, suggesting that there is a certain degree of commonality between psoriasis and cancer. This article reviews the pathological mechanisms that are common to psoriasis and cancer, including the interaction between cell proliferation and an abnormal immune microenvironment, metabolic reprogramming, and epigenetic reprogramming. In addition, there are common therapeutic agents and drug targets between psoriasis and cancer. Thus, psoriasis and cancer share a common pathological mechanisms-drug targets-therapeutic agents framework. On this basis, it is proposed that investigating psoriasis from a cancer perspective is beneficial to enriching the research strategies related to psoriasis.

Comprehensive Analysis to Identify Rh Family C Glycoprotein (RHCG) as the Causative Gene for Psoriasis and Search for Alternative Treatment Modalities

Background

Psoriasis is a complex autoimmune disease. Frequent interactions between epidermal and immune cells are likely to be responsible for the strong heterogeneity of psoriasis. Therefore, our work aims to build on current knowledge and further search for new molecular mechanisms related to psoriasis pathogenesis in order to develop new targeted drugs.

Methods

Data from psoriasis samples were obtained from the Gene Expression Omnibus (GEO) database, and batch effects were corrected using the "Combat" algorithm in the "SVA" package. Functional annotation of differential genes in psoriasis was performed by Gene set enrichment analysis (GSEA). Core functional modules were identified using the Multiscale Embedded Gene Co-Expression Network Analysis (MEGENA) algorithm for selection from the differential gene interaction network. The expression and potential function of Rh Family C Glycoprotein (RHCG) was predicted in single cell data by the "Seurat" package and validated in psoriasis samples by multiplex immunofluorescence. In addition, the regulatory function of HOP Homeobox (HOPX) on RHCG in keratinocytes was confirmed using RNA interference. Using immune infiltration analysis, RHCG and DC cells were analyzed for their association. Finally, the molecular mechanisms of treatment of psoriasis using Tripterygii Radix (TR) and Cinnamomi Ramulus (CR) were explored through network pharmacology and experimental validation.

Results

Immune response (represented by C1_2) and collagen matrix formation (represented by C1_3) were identified as two important pathogenic factors in psoriasis and helped to define new biological subtypes of psoriasis. One important psoriasis hub gene, RHCG, was obtained and found to be closely associated with keratinocyte differentiation as well as DC cell maturation. And RHCG was regulated by HOPX in keratinocytes. In addition, the mechanism of action of CR and TR in the treatment of psoriasis was tentatively confirmed to be related to TRPV3, NFKB2, and YAP1.

Conclusions

Our study identifies a new causal disease gene (RHCG) and offers potential alternatives for the treatment of psoriasis.

Dual role of ANGPTL4 in inflammation

BACKGROUND

Angiopoietin-like 4 (ANGPTL4) belongs to the angiopoietin-like protein family and mediates the inhibition of lipoprotein lipase activity. Emerging evidence suggests that ANGPTL4 has pleiotropic functions with anti- and pro-inflammatory properties.

METHODS

A thorough search on PubMed related to ANGPTL4 and inflammation was performed.

RESULTS

Genetic inactivation of ANGPTL4 can significantly reduce the risk of developing coronary artery disease and diabetes. However, antibodies against ANGPTL4 result in several undesirable effects in mice or monkeys, such as lymphadenopathy and ascites. Based on the research progress on ANGPTL4, we systematically discussed the dual role of ANGPTL4 in inflammation and inflammatory diseases (lung injury, pancreatitis, heart diseases, gastrointestinal diseases, skin diseases, metabolism, periodontitis, and osteolytic diseases). This may be attributed to several factors, including post-translational modification, cleavage and oligomerization, and subcellular localization.

CONCLUSION

Understanding the potential underlying mechanisms of ANGPTL4 in inflammation in different tissues and diseases will aid in drug discovery and treatment development.

Current and emerging prospects in the psoriatic treatment

Psoriasis is an autoimmune chronic disorder that causes inflammation and a scaly epidermis. The exact pathogenesis of the disease is not known yet. According to the studies, psoriasis is considered an immune-mediated disease. Until now it is believed that genetic and environmental factors are responsible for the disease. There are many comorbidities associated with psoriasis which increases difficulties as patients in some cases get addicted to drugs, alcohol, and smoking which reduces their quality of life. The patient may face social ignorance or suicidal thoughts which may arise in the patient's mind. Due to the undefined trigger of the disease, the treatment is not fully established but by considering the severe impact of the disease researchers are focusing on novel approaches for successful treatment. which has succeeded to a large extent. Here we review pathogenesis, problems faced by psoriatic patients, the need for the development of new treatments over conventional therapies, and the history of psoriatic treatments. We thoroughly focus on emerging treatments like biologics, biosimilars, and small molecules which are now showing more efficacy and safety than conventional treatments. Also, this review article discusses novel approaches which are now in research such as drug repurposing, treatment by stimulation of the vagus nerve, regulation of microbiota, and autophagy for improving disease conditions.

Dissolvable hyaluronic acid microneedles loaded with β-Elemene for the treatment of psoriasis

The pathology of psoriasis involves the over-proliferation of keratinocytes, exaggerated inflammation of keratinocytes, and infiltration of inflammatory cells such as macrophages (Mø), etc. The therapeutic outcomes of current treatment targeting one single pathological process are less than satisfactory. Based on their diverse biological activities, natural products offer a potential solution to this problem. In this study, we investigated the effects of β-Elemene (ELE) on both psoriatic keratinocytes and M1-type Mø (M1-Mø) in vitro. Hyaluronic acid (HA) microneedles loaded with ELE (HA-ELE-MN) were also fabricated and tested for the treatment of psoriasis in vivo using an imiquimod (IMQ)-induced psoriatic mice model. Our data suggest that ELE induces apoptosis and inhibits inflammation of psoriatic keratinocytes. In addition, ELE attenuates the expression of inflammatory cytokines secreted from M1-Mø, thus indirectly inhibiting the inflammation of keratinocytes. Furthermore, HA-ELE-MN has been found to significantly alleviate symptoms in an IMQ-induced psoriatic mice model by inducing keratinocytes apoptosis, suppressing keratinocytes proliferation, and inhibiting M1-Mø infiltration. Taken together, this study demonstrates that ELE can be used for the treatment of psoriasis by targeting both keratinocytes and M1-Mø, which provides a potential novel reagent for psoriasis treatment.