Cathepsin S activation contributes to elevated CX3CL1 (fractalkine) levels in tears of a Sjögren's syndrome murine model

Triptolide alleviates cerebral ischemia/reperfusion injury via regulating the Fractalkine/CX3CR1 signaling pathway

PURPOSE

To evaluate the potential efficacy of Triptolide (TP) on cerebral ischemia/reperfusion injury (CIRI) and to uncover the underlying mechanism through which TP regulates CIRI.

METHODS

We constructed a middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model to simulate CIRI, and established a lipopolysaccharide (LPS)-stimulated BV-2 cell model to mimic the inflammatory state during CIRI. The neurological deficits score (NS) of mice were measured for assessment of neurologic functions. Both the severity of cerebral infarction and the apoptosis level in mouse brain tissues or cells were respectively evaluated using corresponding techniques. The expression levels of Ionized calcium binding adapter molecule 1 (IBA-1), Inductible Nitric Oxide Synthase (iNOS), Arginase 1 (Arg-1), Tumor necrosis factor-α (TNF-α), Interleukin 1β (IL-1β), Cysteine histoproteinase S (CTSS), Fractalkine, chemokine C-X3-C motif receptor 1 (CX3CR1), BCL-2-associated X protein (BAX), and antiapoptotic proteins (Bcl-2) were detected using immunofluorescence, qRT-PCR as well as Western blot, respectively.

RESULTS

Relative to the Sham group, treatment with TP attenuated the increased NS, infarct area and apoptosis levels observed in MCAO/R mice. Upregulated expression levels of IBA-1, iNOS, Arg-1, TNF-α and IL-1β were found in MCAO/R mice, while TP suppressed iNOS, TNF-α and IL-1β expression, and enhanced Arg-1 expression in both MCAO/R mice and LPS-stimulated BV-2 cells. Besides, TP inhibited the CTSS/Fractalkine/CX3CR1 pathway activation in both MCAO/R mice and LPS-induced BV-2 cells, while overexpression of CTSS reversed such effect. Co-culturing HT-22 cells with TP+LPS-treated BV-2 cells led to enhanced cell viability and decreased apoptosis levels. However, overexpression of CTSS further aggravated HT-22 cell injury.

CONCLUSION

TP inhibits not only microglia polarization towards the M1 phenotype by suppressing the CTSS/Fractalkine/CX3CR1 pathway activation, but also HT-22 apoptosis by crosstalk with BV-2 cells, thereby ameliorating CIRI. These findings reveal a novel mechanism of TP in improving CIRI, and offer potential implications for addressing the preventive and therapeutic strategies of CIRI.

Conductive Polyisocyanide Hydrogels Inhibit Fibrosis and Promote Myogenesis

Reliable in vitro models closely resembling native tissue are urgently needed for disease modeling and drug screening applications. Recently, conductive biomaterials have received increasing attention in the development of in vitro models as they permit exogenous electrical signals to guide cells toward a desired cellular response. Interestingly, they have demonstrated that they promote cellular proliferation and adhesion even without external electrical stimulation. This paper describes the development of a conductive, fully synthetic hydrogel based on hybrids of the peptide-modified polyisocyanide (PIC-RGD) and the relatively conductive poly(aniline-co-N-(4-sulfophenyl)aniline) (PASA) and its suitability as the in vitro matrix. We demonstrate that incorporating PASA enhances the PIC-RGD hydrogel's electroactive nature without significantly altering the fibrous architecture and nonlinear mechanics of the PIC-RGD network. The biocompatibility of our model was assessed through phenotyping cultured human foreskin fibroblasts (HFF) and murine C2C12 myoblasts. Immunofluorescence analysis revealed that PIC-PASA hydrogels inhibit the fibrotic behavior of HFFs while promoting myogenesis in C2C12 cells without electrical stimulation. The composite PIC-PASA hydrogel can actively change the cell fate of different cell types, providing an attractive tool to improve skin and muscle repair.

Chemokines and lymphocyte homing in Sjögren's syndrome

Sjögren's syndrome (SS) is a chronic systemic autoimmune disease that typically presents with lymphocyte, dendritic cell, and macrophage infiltration of exocrine gland ducts and the formation of ectopic germinal centers. The interactions of lymphocyte homing receptors and addressins and chemokines and their receptors, such as α4β7/MAdCAM-1, LFA-1/ICAM-1, CXCL13/CXCR5, CCL25/CCR9, CX3CL1/CX3CR1, play important roles in the migration of inflammatory cells to the focal glands and the promotion of ectopic germinal center formation in SS. A variety of molecules have been shown to be involved in lymphocyte homing, including tumor necrosis factor-α, interferon (IFN)-α, IFN-β, and B cell activating factor. This process mainly involves the Janus kinase-signal transducer and activator of transcription signaling pathway, lymphotoxin-β receptor pathway, and nuclear factor-κB signaling pathway. These findings have led to the development of antibodies to cell adhesion molecules, antagonists of chemokines and their receptors, compounds interfering with chemokine receptor signaling, and gene therapies targeting chemokines and their receptors, providing new targets for the treatment of SS in humans. The aim of this study was to explore the relationship between lymphocyte homing and the pathogenesis of SS, and to provide a review of recent studies addressing lymphocyte homing in targeted therapy for SS.

An Improved Understanding of the Pathophysiology of Pelvic Organ Prolapse: A 3D In Vitro Model under Static and Mechanical Loading Conditions

The suboptimal outcomes of pelvic organ prolapse (POP) surgery illustrate the demand for improved therapies. However, their development is hampered by the limited knowledge on the cellular pathophysiology of POP. Current investigations, that are limited to tissues and 2D in vitro models, provide highly inconclusive results on how the extracellular matrix (ECM) metabolism and fibroblasts are affected in POP. This study uses a physiologically relevant 3D in vitro model to investigate the cellular pathophysiology of POP by determining the differences between POP and non-POP fibroblasts on ECM metabolism, proliferation, and fibroblast-to-myofibroblast (FMT) transition. This model, based on the synthetic and biomimetic polyisocyanide hydrogel, enables the incorporation of mechanical loading, which simulates the forces exerted on the pelvic floor. Under static conditions, 3D cultured POP fibroblasts are less proliferative, undergo FMT, and exhibit lower collagen and elastin contents compared to non-POP fibroblasts. However, under mechanical loading, the differences between POP and non-POP fibroblasts are less pronounced. This study contributes to the development of more comprehensive models that can accurately mimic the POP pathophysiology, which will aid in an enhanced understanding and may contribute to improved therapies in the future.

Antifibrotic properties of hyaluronic acid crosslinked polyisocyanide hydrogels

Fibrosis is characterized by the formation of fibrous connective tissue in response to primary injury. As a result, an affected organ may lose part of its functionality due to chronic, organ-specific tissue damage. Since fibrosis is a leading cause of death worldwide, targeting fibrotic diseases with antifibrotic hydrogels can be a lifesaving therapeutic strategy. This study developed a novel hybrid antifibrotic hydrogel by combining the synthetic polyisocyanide (PIC) with hyaluronic acid (HA). Gels of PIC are highly tailorable, thermosensitive, and strongly biomimetic in architecture and mechanical properties, whereas HA is known to promote non-fibrotic fetal wound healing and inhibits inflammatory signaling. The developed HA-PIC hybrids were biocompatible with physical properties comparable to those of the PIC gels. The antifibrotic nature of the gels was assessed by 3D cultures of human foreskin fibroblasts in the presence (or absence as control) of TGFβ1 that promotes differentiation into myofibroblasts, a critical step in fibrosis. Proliferation and macroscopic contraction assays and studies on the formation of stress fibers and characteristic fibrosis markers all indicate a strong antifibrotic nature of HA-PIC hydrogel. We showed that these effects originate from both the lightly crosslinked architecture and the presence of HA itself. The hybrid displaying both these effects shows the strongest antifibrotic nature and is a promising candidate for use as in vivo treatment for skin fibrosis.

Gene expression signatures in conjunctival fornix aspirates of patients with dry eye disease associated with Meibomian gland dysfunction. A proof-of-concept study

BACKGROUND

Meibomian gland dysfunction (MGD) is one of the most common conditions in ophthalmic practice and the most frequent cause of evaporative dry eye disease (DED). However, the immune mechanisms leading to this pathology are not fully understood and the diagnostic tests available are limited. Here, we used the nCounter technology to analyze immune gene expression in DED-MGD that can be used for developing diagnostic signatures for DED.

METHODS

Conjunctival cell samples were obtained by aspiration from patients with DED-MGD (n = 27) and asymptomatic controls (n = 22). RNA was purified, converted to cDNA, preamplified and analyzed using the Gene Expression Human Immune V2 panel (NanoString), which includes 579 target and 15 housekeeping genes. A machine learning (ML) algorithm was applied to design a signature associated with DED-MGD.

RESULTS

Forty-five immune genes were found upregulated in DED-MGD vs. controls, involved in eight signaling pathways, IFN I/II, MHC class I/II, immunometabolism, B cell receptor, T Cell receptor, and T helper-17 (Th-17) differentiation. Additionally, statistically significant correlations were found between 31 genes and clinical characteristics of the disease such as lid margin or tear osmolarity (Pearson's r < 0.05). ML analysis using a recursive feature elimination (RFE) algorithm selected a 4-gene mRNA signature that discriminated DED-MGD from control samples with an area under the ROC curve (AUC ROC) of 0.86 and an accuracy of 77.5%.

CONCLUSIONS

Multiplexed mRNA analysis of conjunctival cells can be used to analyze immune gene expression patterns in patients with DED-MGD and to generate diagnostic signatures.

hsa-miR-424-5p and hsa-miR-513c-3p dysregulation mediated by IFN-γ is associated with salivary gland dysfunction in Sjögren's syndrome patients

Salivary secretory dysfunction in SS-patients is associated with altered proteostasis, upregulation of ATF6α and components of the ERAD complex, such as SEL1L, and downregulation of XBP-1s and GRP78. Hsa-miR-424-5p is downregulated and hsa-miR-513c-3p is overexpressed in salivary glands from SS-patients. These miRNAs emerged as candidates that could regulate ATF6/SEL1L and XBP-1s/GRP78 levels, respectively. This study aimed to evaluate the effect of IFN-γ on hsa-miR-424-5p and hsa-miR-513c-3p expression and how these miRNAs regulate their targets. In labial salivary glands (LSG) biopsies from 9 SS-patients and 7 control subjects and IFN-γ-stimulated 3D-acini were analyzed. hsa-miR-424-5p and hsa-miR-513c-3p levels were measured by TaqMan assays and their localization by ISH. mRNA, protein levels, and localization of ATF6, SEL1L, HERP, XBP-1s and GRP78 were determined by qPCR, Western blot, or immunofluorescence. Functional and interaction assays were also performed. In LSGs from SS-patients and IFN-γ-stimulated 3D-acini, hsa-miR-424-5p was downregulated and ATF6α and SEL1L were upregulated. ATF6α and SEL1L were decreased after hsa-miR-424-5p overexpression, while ATF6α, SEL1L and HERP increased after hsa-miR-424-5p silencing. Interaction assays revealed that hsa-miR-424-5p targets ATF6α directly. hsa-miR-513c-3p was upregulated and XBP-1s and GRP78 were downregulated. XBP-1s and GRP78 were decreased after hsa-miR-513c-3p overexpression, while increases in XBP-1s and GRP78 were observed after hsa-miR-513c-3p silencing. Furthermore, we determined that hsa-miR-513c-3p targets XBP-1s directly. Significant correlations were found between both miRNA levels and clinical parameters. In conclusion, IFN-γ-dependent hsa-miR-424-5p and hsa-miR-513c-3p levels affect the expression of important factors involved in cellular proteostasis that control secretory function in LSG from SS-patients.

Early Dry Eye Disease Onset in a NOD.H-2h4 Mouse Model of Sjögren's Syndrome

Purpose

To develop a mouse model of human dry eye disease (DED) for investigation of sex differences in autoimmune-associated dry eye pathology.

Methods

Ocular surface disease was assessed by quantifying corneal epithelial damage with lissamine green stain in the NOD.H-2^h4,IFNγ^−/−,CD28^−/− (NOD.H-2^h4 DKO) mouse model of Sjögren's syndrome (SS). Lacrimal gland function was assessed by tear volume quantification with phenol red thread and lacrimal gland inflammation (i.e., dacryoadenitis) was assessed by quantification of immune cell foci, flow cytometric analysis of immune cell composition, and expression of proinflammatory markers.

Results

The NOD.H-2^h4 DKO mouse model of SS exhibits greater age-dependent increases in corneal damage than in NOD.H-2^h4 parental mice and demonstrates an earlier disease onset in females compared to males. The severity of ocular surface disease correlates with loss of goblet cell density, increased conjunctivitis, and dacryoadenitis that is more pronounced in NOD.H-2^h4 DKO than NOD.H-2^h4 mice. B cells dominate lacrimal infiltrates in 16-week-old NOD.H-2^h4 and NOD.H-2^h4 DKO mice, but T helper cells and macrophages are also present. Lacrimal gland expression of proinflammatory genes, including the P2X7 and P2Y₂ purinergic receptors, is greater in NOD.H-2^h4 DKO than NOD.H-2^h4 mice and correlates with dacryoadenitis.

Conclusions

Our results demonstrate for the first time that autoimmune dry eye disease occurs in both sexes of NOD.H-2^h4 DKO and NOD.H-2^h4 mice, with earlier onset in female NOD.H-2^h4 DKO mice when compared to males of the same strain. This study demonstrates that both NOD.H-2^h4 and NOD.H-2^h4 DKO mice are novel models that closely resemble SS-related and sex-dependent DED.

Novel Synthetic Polymer-Based 3D Contraction Assay: A Versatile Preclinical Research Platform for Fibrosis

The driving factors causing fibrosis and scar formation include fibroblast differentiation into myofibroblasts and hampered myofibroblast apoptosis, which ultimately results in collagen accumulation and tissue contraction. Currently, only very few drugs are available for fibrosis treatment, and there is an urgent demand for new pharmaceutical products. High-throughput in vitro fibrosis models are necessary to develop such drugs. In this study, we developed such a novel model based on synthetic polyisocyanide (PIC-RGD) hydrogels. The model not only measures contraction but also allows for subsequent molecular and cellular analysis. Fibroblasts were seeded in small (10 μL) PIC-RGD gels in the absence or presence of TGFβ1, the latter to induce myofibroblast differentiation. The contraction model clearly differentiates fibroblasts and myofibroblasts. Besides a stronger contraction, we also observed α-smooth muscle actin (αSMA) production and higher collagen deposition for the latter. The results were supported by mRNA expression experiments of αSMA, Col1α1, P53, and Ki67. As proof of principle, the effects of FDA-approved antifibrotic drugs nintedanib and pirfenidone were tested in our newly developed fibrosis model. Both drugs clearly reduce myofibroblast-induced contraction. Moreover, both drugs significantly decrease myofibroblast viability. Our low-volume synthetic PIC-RGD hydrogel platform is an attractive tool for high-throughput in vitro antifibrotic drug screening.

Targeted Therapy for Primary Sjögren's Syndrome: Where are We Now?

Primary Sjögren's syndrome (pSS) is an autoimmune exocrinopathy characterized by dryness symptoms. This review briefly describes recent advances in the targeted therapies for pSS. Biologics evaluated for pSS treatment mainly include B cell-depleting agents, inhibitors of B cell activation, and agents that target co-signaling molecules or proinflammatory cytokines. Small molecule inhibitors that target signaling pathways have also been evaluated. However, current evidence for the efficacy of targeted therapies in pSS is still sparse. Although ianalumab (an anti-B cell-activating factor [BAFF]-receptor antibody) and iscalimab (an anti-CD40 antibody) are promising biologics for pSS, their efficacy still needs to be evaluated in larger clinical trials. For other biologics, clinical trials have found no differences versus placebo in the change from baseline in European League Against Rheumatism Sjögren's Syndrome Disease Activity Index (ESSDAI) score and fatigue score. Possible causes of the disappointing outcomes mainly include the inefficacy of those evaluated biologics in treating pSS, the high heterogeneous nature of pSS, irreversible exocrine glandular failure at advanced disease stages, inappropriate recruitment strategy in clinical trials, and outcome measures. Early diagnosis and glandular function-centered outcome measures may help to improve the current situation in the systemic therapy of pSS.

The chemotherapeutic drug carboplatin affects macrophage responses to LPS and LPS tolerance via epigenetic modifications

Following re-exposure to lipopolysaccharide (LPS), macrophages exhibit an immunosuppressive state known as LPS tolerance, which is characterized by repressed proinflammatory cytokine production. LPS-induced tolerance in macrophages is mediated in part by epigenetic changes. Carboplatin, an anticancer chemotherapeutic drug, exerts its effect by inhibiting DNA replication and transcription, as well as through epigenetic modifications. Through an unbiased screen, we found that carboplatin rescued TNF-α and IL-6 production in LPS-tolerant macrophages. Transcriptomic analysis and gene set enrichment analyses revealed that p53 was one of the most significantly upregulated hallmarks in both LPS-primed and LPS-tolerant macrophages in the presence of carboplatin, while E2F and G2/M were the most negatively regulated hallmarks. Heterochromatin protein 1 (HP1-α), which is associated with gene silencing, was significantly reduced in carboplatin-treated LPS-tolerant macrophages at the mRNA and protein levels. Dynamic changes in the mRNA level of genes encoding H3K9me3 methyltransferases, setdb2, kdm4d, and suv39h1 were induced in the presence of carboplatin in LPS-tolerant macrophages. Taken together, we provide evidence that carboplatin treatment interferes with proinflammatory cytokine production during the acute LPS response and LPS tolerance in macrophages, possibly via H3K9me3 modification.

Phenylephrine increases tear cathepsin S secretion in healthy murine lacrimal gland acinar cells through an alternative secretory pathway

Little is known about the relationship between stimulation of lacrimal gland (LG) tear protein secretion by parasympathetic versus sympathetic nerves, particularly whether the spectrum of tear proteins evoked through each innervation pathway varies. We have previously shown that activity and abundance of cathepsin S (CTSS), a cysteine protease, is greatly increased in tears of Sjögren's syndrome (SS) patients and in tears from the male NOD mouse of autoimmune dacryoadenitis that recapitulates SS-associated dry eye disease. Beyond the increased synthesis of CTSS detected in the diseased NOD mouse LG, increased tear CTSS secretion in NOD mouse tears was recently linked to increased exocytosis from a novel endolysosomal secretory pathway. Here, we have compared secretion and trafficking of CTSS in healthy mouse LG acinar cells stimulated with either the parasympathetic acetylcholine receptor agonist, carbachol (CCh), or the sympathetic α₁-adrenergic agonist, phenylephrine (PE). In situ secretion studies show that PE significantly increases CTSS activity and protein in tears relative to CCh stimulation by 1.2-fold (***, p = 0.0009) and ∼5-fold (*, p-0.0319), respectively. A similar significant increase in CTSS activity with PE relative to CCh is observed when cultured LGAC are stimulated in vitro. CCh stimulation significantly elevates intracellular [Ca²⁺], an effect associated with increases in the size of Rab3D-enriched vesicles consistent with compound fusion, and subsequently decreases in their intensity of labeling consistent with their exocytosis. PE stimulation induces a lower [Ca²⁺] response and has minimal effects on Rab3D-enriched SV diameter or the intensity of Rab3D-enriched SV labeling. LG deficient in Rab3D exhibit a higher sensitivity to PE stimulation, and secrete more CTSS activity. Significant increases in the colocalization of endolysosomal vesicle markers (Lamp1, Lamp2, Rab7) with the subapical actin suggestive of fusion of endolysosomal vesicles at the apical membrane occur both with CCh and PE stimulation, but PE demonstrates increased colocalization. In conclusion, the α₁-adrenergic agonist, PE, increases CTSS secretion into tears through a pathway independent of the exocytosis of Rab3D-enriched mature SV, possibly representing an alternative endolysosomal secretory pathway.

Insights Into Transcriptome Profiles Associated With Wooden Breast Myopathy in Broilers Slaughtered at the Age of 6 or 7 Weeks

Transcriptomes associated with wooden breast (WB) were characterized in broilers at two different market ages. Breasts (Pectoralis major) were collected, 20-min postmortem, from male Ross 308 broilers slaughtered at 6 and 7 weeks of age. The breasts were classified as "non-WB" or "WB" based on palpation hardness scoring (non-WB = no abnormal hardness, WB = consistently hardened). Total RNA was isolated from 16 samples (n = 3 for 6 week non-WB, n = 3 for 6 week WB; n = 5 for 7 week non-WB, n = 5 for 7 week WB). Transcriptome was profiled using a chicken gene expression microarray with one-color hybridization technique, and compared between non-WB and WB samples of the same age. Among 6 week broilers, 910 transcripts were differentially expressed (DE) (false discovery rate, FDR < 0.05). Pathway analysis underlined metabolisms of glucose and lipids along with gap junctions, tight junction, and focal adhesion (FA) signaling as the top enriched pathways. For the 7 week broilers, 1,195 transcripts were identified (FDR < 0.05) with regulation of actin cytoskeleton, mitogen-activated protein kinase (MAPK) signaling, protein processing in endoplasmic reticulum and FA signaling highlighted as the enriched affected pathways. Absolute transcript levels of eight genes (actinin-1 - ACTN1, integrin-linked kinase - ILK, integrin subunit alpha 8 - ITGA8, integrin subunit beta 5 - ITGB5, protein tyrosine kinase 2 - PTK2, paxillin - PXN, talin 1 - TLN1, and vinculin - VCL) of FA signaling pathway were further elucidated using a droplet digital polymerase chain reaction. The results indicated that, in 6 week broilers, ITGA8 abundance in WB was greater than that of non-WB samples (p < 0.05). Concerning 7 week broilers, greater absolute levels of ACTN1, ILK, ITGA8, and TLN1, accompanied with a reduced ITGB5 were found in WB compared with non-WB (p < 0.05). Transcriptional modification of FA signaling underlined the potential of disrupted cell-cell communication that may incite aberrant molecular events in association with development of WB myopathy.

Rab27a Contributes to Cathepsin S Secretion in Lacrimal Gland Acinar Cells

Altered lacrimal gland (LG) secretion is a feature of autoimmune dacryoadenitis in Sjögren's syndrome (SS). Cathepsin S (CTSS) is increased in tears of SS patients, which may contribute to disease. Rab3D and Rab27a/b isoforms are effectors of exocytosis in LG, but Rab27a is poorly studied. To investigate whether Rab27a mediates CTSS secretion, we utilized quantitative confocal fluorescence microscopy of LG from SS-model male NOD and control male BALB/c mice, showing that Rab27a-enriched vesicles containing CTSS were increased in NOD mouse LG. Live-cell imaging of cultured lacrimal gland acinar cells (LGAC) transduced with adenovirus encoding wild-type (WT) mCFP-Rab27a revealed carbachol-stimulated fusion and depletion of mCFP-Rab27a-enriched vesicles. LGAC transduced with dominant-negative (DN) mCFP-Rab27a exhibited significantly reduced carbachol-stimulated CTSS secretion by 0.5-fold and β-hexosaminidase by 0.3-fold, relative to stimulated LGAC transduced with WT mCFP-Rab27a. Colocalization of Rab27a and endolysosomal markers (Rab7, Lamp2) with the apical membrane was increased in both stimulated BALB/c and NOD mouse LG, but the extent of colocalization was much greater in NOD mouse LG. Following stimulation, Rab27a colocalization with endolysosomal membranes was decreased. In conclusion, Rab27a participates in CTSS secretion in LGAC though the major regulated pathway, and through a novel endolysosomal pathway that is increased in SS.

Integrative Identification of Hub Genes Associated With Immune Cells in Atrial Fibrillation Using Weighted Gene Correlation Network Analysis

Background: Atrial fibrillation (AF) is the most common tachyarrhythmia in the clinic, leading to high morbidity and mortality. Although many studies on AF have been conducted, the molecular mechanism of AF has not been fully elucidated. This study was designed to explore the molecular mechanism of AF using integrative bioinformatics analysis and provide new insights into the pathophysiology of AF. Methods: The GSE115574 dataset was downloaded, and Cibersort was applied to estimate the relative expression of 22 kinds of immune cells. Differentially expressed genes (DEGs) were identified through the limma package in R language. Weighted gene correlation network analysis (WGCNA) was performed to cluster DEGs into different modules and explore relationships between modules and immune cell types. Functional enrichment analysis was performed on DEGs in the significant module, and hub genes were identified based on the protein-protein interaction (PPI) network. Hub genes were then verified using quantitative real-time polymerase chain reaction (qRT-PCR). Results: A total of 2,350 DEGs were identified and clustered into eleven modules using WGCNA. The magenta module with 246 genes was identified as the key module associated with M1 macrophages with the highest correlation coefficient. Three hub genes (CTSS, CSF2RB, and NCF2) were identified. The results verified using three other datasets and qRT-PCR demonstrated that the expression levels of these three genes in patients with AF were significantly higher than those in patients with SR, which were consistent with the bioinformatic analysis. Conclusion: Three novel genes identified using comprehensive bioinformatics analysis may play crucial roles in the pathophysiological mechanism in AF, which provide potential therapeutic targets and new insights into the treatment and early detection of AF.