S100A2 Silencing Relieves Epithelial-Mesenchymal Transition in Pulmonary Fibrosis by Inhibiting the Wnt/β-Catenin Signaling Pathway

Novel AT2 Cell Subpopulations and Diagnostic Biomarkers in IPF: Integrating Machine Learning with Single-Cell Analysis

Idiopathic pulmonary fibrosis (IPF) is a long-term condition with an unidentified cause, and currently there are no specific treatment options available. Alveolar epithelial type II cells (AT2) constitute a heterogeneous population crucial for secreting and regenerative functions in the alveolus, essential for maintaining lung homeostasis. However, a comprehensive investigation into their cellular diversity, molecular features, and clinical implications is currently lacking. In this study, we conducted a comprehensive examination of single-cell RNA sequencing data from both normal and fibrotic lung tissues. We analyzed alterations in cellular composition between IPF and normal tissue and investigated differentially expressed genes across each cell population. This analysis revealed the presence of two distinct subpopulations of IPF-related alveolar epithelial type II cells (IR_AT2). Subsequently, three unique gene co-expression modules associated with the IR_AT2 subtype were identified through the use of hdWGCNA. Furthermore, we refined and identified IPF-related AT2-related gene (IARG) signatures using various machine learning algorithms. Our analysis demonstrated a significant association between high IARG scores in IPF patients and shorter survival times (p-value < 0.01). Additionally, we observed a negative correlation between the percent predicted diffusing capacity for lung carbon monoxide (% DLCO) and increased IARG scores (cor = -0.44, p-value < 0.05). The cross-validation findings demonstrated a high level of accuracy (AUC > 0.85, p-value < 0.01) in the prognostication of patients with IPF utilizing the identified IARG signatures. Our study has identified distinct molecular and biological features among AT2 subpopulations, specifically highlighting the unique characteristics of IPF-related AT2 cells. Importantly, our findings underscore the prognostic relevance of specific genes associated with IPF-related AT2 cells, offering valuable insights into the advancement of IPF.

Single-cell RNA sequencing reveals special basal cells and fibroblasts in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is the most predominant type of idiopathic interstitial pneumonia and has an increasing incidence, poor prognosis, and unclear pathogenesis. In order to investigate the molecular mechanisms underlying IPF further, we performed single-cell RNA sequencing analysis on three healthy controls and five IPF lung tissue samples. The results revealed a significant shift in epithelial cells (ECs) phenotypes in IPF, which may be attributed to the differentiation of alveolar type 2 cells to basal cells. In addition, several previously unrecognized basal cell subtypes were preliminarily identified, including extracellular matrix basal cells, which were increased in the IPF group. We identified a special population of fibroblasts that highly expressed extracellular matrix-related genes, POSTN, CTHRC1, COL3A1, COL5A2, and COL12A1. We propose that the close interaction between ECs and fibroblasts through ligand-receptor pairs may have a critical function in IPF development. Collectively, these outcomes provide innovative perspectives on the complexity and diversity of basal cells and fibroblasts in IPF and contribute to the understanding of possible mechanisms in pathological lung fibrosis.

Panax notoginseng saponins improve oral submucous fibrosis by inhibiting the Wnt/β-catenin signal pathway

OBJECTIVE

Oral submucous fibrosis (OSF) is a chronic, insidious, progressive mucosal disease that may be affected by mutations in the Wnt/β-catenin signaling pathway. Panax notoginseng saponins (PNS) is a powerful anti-fibrosis agent; however, its effect and mechanism in treating OSF remain unclear. This study investigated the effect and mechanism of PNS treatment for OSF.

STUDY DESIGN

Arecoline was used to induce OSF models in vivo and in vitro, which were then treated with PNS. Hematoxylin-eosin (HE) and Masson trichrome staining were used to observe histopathology changes; E-cadherin and β-catenin were detected by Immunohistochemical assay, and type Ⅰ collagen (CollA1) and β-catenin were detected by immunofluorescent staining. The Wnt/β-catenin pathway and fibrosis signs were assessed using Western Blot and real-time quantitative polymerase chain reaction (RT-qPCR).

RESULTS

The expression of CollA1, Wnt1, and β-catenin were increased, and E-cadherin, GSK-3β, and β-catenin expression were decreased in OSF models. PNS and inhibitor intervention increased E-cadherin, Wnt1, and β-catenin and decreased CollA1 and GSK-3β in a dose-dependent manner.

CONCLUSION

PNS can improve OSF by inhibiting the Wnt/β-catenin signal pathway and thus may be used as a potential medicine for the treatment of OSF.

Sinapine thiocyanate exhibited anti-colorectal cancer effects by inhibiting KRT6A/S100A2 axis

Sinapine thiocyanate (ST), an alkaloid existed extensively in seeds of cruciferous plants, exhibits a number of pharmacological effects, including anti-inflammatory and anti-malignancy properties. However, it is still unknown what effects and molecular mechanisms ST has on colorectal cancer (CRC). In the current study, it was indicated that ST inhibited proliferation, colony formation, and apoptosis in vitro, as well as arrested the G1 phase of CRC cells. There was a significant repressive effects of ST on invasion and migration of CRC cells in vitro. RNA-sequencing indicated that 750 differentially expressed genes existed in CRC cells after ST treatment, and enrichment analysis demonstrated that ST obviously decreased the activation of keratinization pathways. Among DEGs enriched in keratinization, keratin 6A (KRT6A) was decreased the most significant, as well as its target gene S100 calcium-binding protein A2 (S100A2). Low expression of KRT6A and S100A2 signatures indicated a favorable prognosis in CRC patients. Moreover, we found overexpression of KRT6A relieved the inhibitory effects of ST in CRC cells. Furthermore, ST inhibited the CRC cell proliferation in vivo, and reduced KRT6A and KI67 expression in xenograft tumor. Taken together, we demonstrated that ST exhibited anti-CRC properties by inhibiting KRT6A/S100A2 axis. It is possible that ST can be used as a treatment for CRC.

Molecular Mechanism in the Development of Pulmonary Fibrosis in Patients with Sarcoidosis

Sarcoidosis is a multisystemic disease of unknown etiology characterized by the formation of granulomas in various organs, especially lung and mediastinal hilar lymph nodes. The clinical course and manifestations are unpredictable: spontaneous remission can occur in approximately two thirds of patients; up to 20% of patients have chronic course of the lung disease (called advanced pulmonary sarcoidosis, APS) resulting in progressive loss of lung function, sometimes life-threatening that can lead to respiratory failure and death. The immunopathology mechanism leading from granuloma formation to the fibrosis in APS still remains elusive. Recent studies have provided new insights into the genetic factors and immune components involved in the clinical manifestation of the disease. In this review we aim to summarize the clinical-prognostic characteristics and molecular pathways which are believed to be associated with the development of APS.

Immunohistochemical analysis of S100-proteins in normal and irreversibly inflamed human dental pulps

AIM

S100 proteins convey important roles in innate immune responses to infection and regenerative processes. Their role in inflammatory or regenerative processes of the human dental pulp, however, is poorly elucidated. Aim of the present study was to detect, localize and compare the occurrence of eight S100 proteins in normal, symptomatic, and asymptomatic irreversibly inflamed dental pulp specimens.

METHODOLOGY

Human dental pulp specimens from forty-five individuals were clinically assigned to three groups of pulpal diagnosis, "normal pulp" (NP; n=17), "asymptomatic irreversible pulpitis" (AIP; n=13), and "symptomatic irreversible pulpitis" (SIP; n=15). The specimens were prepared and immunohistochemically stained for proteins S100A1, -A2, -A3, -A4, -A6, -A7, -A8, and -A9. Staining was classified using semi quantitative analysis and a four-degree staining score ("no", "decent", "medium" and "intense" staining) at four different anatomical or functional regions [odontoblast layer (OL), pulpal stroma (PS), border area of calcifications (BAC), and vessel walls (VW)]. Distribution of staining degrees between the three diagnostic groups was calculated using fisher´s exact text (p≤0.5) at the four regions.

RESULTS

Significant differences in staining were observed mainly in the OL, PS, and at BAC. The most significant differences were detected in PS and when comparing NP with one of the two irreversibly inflamed pulpal tissues (AIP or SIP). The inflamed tissues were then invariably stained more intensely than their normal counterparts at this location (S100A1, -A2, -A3, -A4, -A8, and -A9). In the OL, NP tissue was significantly stronger stained for S100A1, -A6, -A8, and -A9 compared with SIP, and for S100A9 when compared with AIP. Differences between AIP and SIP in direct comparison were rare and found only for one protein (S100A2) at the BAC. Also at the VW, only one statistical difference in staining was observed (SIP was stronger stained than NP for protein S100A3).

CONCLUSIONS

Occurrence of proteins S100A1, -A2, -A3, -A4, -A6, -A8, and -A9 is significantly altered in irreversibly inflamed compared with normal dental pulp tissue at different anatomical localizations. Some members of S100 proteins obviously participate in focal calcification processes and pulp stone formation of the dental pulp.

TMT-based quantitative proteomic analysis reveals the underlying mechanisms of glycidyl methacrylate-induced 16HBE cell malignant transformation

Glycidyl methacrylate (GMA) has been widely used as tackifying/crosslinking copolymer monomer in the industrial section. Occupational and environmental exposure to GMA is inevitable. GMA is classified as a Group 2 A carcinogen. However, it still lacks a sufficient understanding of its carcinogenicity at the protein level. The major pathways and players during the malignant transformation process remain unknown. In this study, we first established and characterized a malignant transformation model using human bronchial epithelial (16HBE) cells exposed to 8 μg/mL GMA. Then the proteomics approach, western-blot analysis as well as quantitative PCR (qPCR) analysis were employed to investigate its underlying mechanisms of carcinogenicity. Our results showed that the 16HBE cells exposed to GMA and passaged to the 40th generation had undergone a malignant transformation. Proteomic analysis revealed that 123 proteins were significantly up-regulated while 160 proteins were down-regulated during the process of malignant transformation. Importantly, further pathway analysis identified the extracellular matrix-receptor (ECM-receptor) interaction pathway to be one of the major players mediating the process and most of the differentially expressed proteins (DEPs) were up-regulated, including two vital proteins, CD44 and MMP14, as well as members from integrin family. These results provide direct proteomic evidence that DEPs related to the ECM-receptor interaction pathway play an active role in reinforcing the carcinogenicity of GMA. The findings of this study might deepen our understanding of the underlying mechanisms of GMA carcinogenicity and thus facilitate the risk assessment of GMA.

Influence of S100A2 in Human Diseases

S100 proteins are a family of low-molecular-weight proteins characterized by two calcium-binding sites with a helix-loop-helix (“EF-hand-type”) domain. The S100 family of proteins is distributed across various organs and can interact with diverse molecules. Among the proteins of the S100 family, S100 calcium-binding protein A2 (S100A2) has been identified in mammary epithelial cells, glands, lungs, kidneys, and prostate gland, exhibiting various physiological and pathological actions in human disorders, such as inflammatory diseases and malignant tumors. In this review, we introduce basic knowledge regarding S100A2 regulatory mechanisms. Although S100A2 is a tumor suppressor, we describe the various influences of S100A2 on cancer and inflammatory diseases.

Integrative Analysis of Biomarkers and Mechanisms in Adamantinomatous Craniopharyngioma

Craniopharyngioma is a benign tumor, and the predominant treatment methods are surgical resection and radiotherapy. However, both treatments may lead to complex complications, seriously affecting patients’ survival rate and quality of life. Adamantinomatous craniopharyngioma (ACP), as one of the histological subtypes of craniopharyngioma, is associated with a high incidence and poor prognosis, and there is a gap in the targeted therapy of immune-related genes for ACP. In this study, two gene expression profiles of ACP, namely GSE68015 and GSE94349, were downloaded from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) were identified by the Limma package, and 271 differentially expressed immune-related genes (DEIRGs) were obtained from the Immport database. The gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA) were performed for annotation, visualization, and integrated discovery. Five hub genes, including CXCL6, CXCL10, CXCL11, CXCL13, and SAA1, were screened out through protein-protein interaction (PPI) network interaction construction. Two diagnostic markers, namely S100A2 and SDC1 (both of which have the Area Under Curve value of 1), were screened by the machine learning algorithm. CIBERSORT analysis showed that M2 macrophages, activated NK cells, and gamma delta T cells had higher abundance in ACP infiltration, while CD8+ T cells, regulatory T cells, and Neutrophils had less abundance in ACP infiltration. The expression of gamma delta T cells was positively correlated with CXCL6, S100A2, SDC1, and SAA1, while CD8+ T cells expression was negatively correlated with CXCL6, S100A2, SDC1, and CXCL10. ACP with high CXCL6 showed remarkable drug sensitivity to Pentostatin and Wortmannin via CellMiner database analysis. Our results deepened the understanding of the molecular immune mechanism in ACP and provided potential biomarkers for the precisely targeted therapy for ACP.

Pathogenic Effects of Mineralocorticoid Pathway Activation in Retinal Pigment Epithelium

Glucocorticoids are amongst the most used drugs to treat retinal diseases of various origins. Yet, the transcriptional regulations induced by glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) activation in retinal pigment epithelium cells (RPE) that form the outer blood-retina barrier are unknown. Levels of endogenous corticoids, ligands for MR and GR, were measured in human ocular media. Human RPE cells derived from induced pluripotent stem cells (iRPE) were used to analyze the pan-transcriptional regulations induced by aldosterone-an MR-specific agonist, or cortisol or cortisol + RU486-a GR antagonist. The retinal phenotype of transgenic mice that overexpress the human MR (P1.hMR) was analyzed. In the human eye, the main ligand for GR and MR is cortisol. The iRPE cells express functional GR and MR. The subset of genes regulated by aldosterone and by cortisol + RU-486, and not by cortisol alone, mimics an imbalance toward MR activation. They are involved in extracellular matrix remodeling (CNN1, MGP, AMTN), epithelial-mesenchymal transition, RPE cell proliferation and migration (ITGB3, PLAUR and FOSL1) and immune balance (TNFSF18 and PTX3). The P1.hMR mice showed choroidal vasodilation, focal alteration of the RPE/choroid interface and migration of RPE cells together with RPE barrier function alteration, similar to human retinal diseases within the pachychoroid spectrum. RPE is a corticosteroid-sensitive epithelium. MR pathway activation in the RPE regulates genes involved in barrier function, extracellular matrix, neural regulation and epithelial differentiation, which could contribute to retinal pathology.

The S100 protein family in lung cancer

The S100 protein family is involved in the pathogenesis of several malignancies including lung cancer. Recent studies have shown that one member, S100A2, was over-expressed in advanced stage non-small cell lung cancer (NSCLC). Another, S100A6, demonstrated variable expression in different lung cancer subtypes. Research using NSCLC cell lines reported that SIX3 inhibited cell metastasis and proliferation via S100P down-regulation. This review represents an update on S100 proteins in lung cancer from 2017 to 2021 and includes the aforementioned as well as S100A4, S100A7, and S100B. Inconsistencies in mechanisms of action for S100A8/S100A9 are highlighted and a comprehensive evaluation of the most recent evidence for the S100 proteins in lung cancer is presented.