Paclitaxel and Vinblastine Increase Plasminogen Activator Inhibitor-1 Production in Human Breast Cancer MCF-7 Cells but Not MDA-MB-231 Cells.

Cancer chemotherapy increases the risk of thrombosis; however, the mechanisms underlying this thrombosis are not completely understood. Plasminogen activator inhibitor (PAI)-1 is a key molecule in the fibrinolytic system that inhibits tissue plasminogen activator and urokinase, which converts plasminogen into plasmin; therefore, excess PAI-1 increases the risk of thrombosis. In this study, we investigated whether temporary treatment of the human luminal A-type breast cancer cell line MCF-7 with antitumor drugs clinically used for breast cancer therapy promotes PAI-1 production. Treatment of MCF-7 cells with paclitaxel (PTX), a microtubule-stabilizing antitumor drug, at 1 µM for 2 h elevated the PAI-1 concentration of the conditioned medium at 48 h after treatment but not in those treated with tamoxifen and cyclophosphamide. Microtubule assembly inhibitors vinblastine (VBT) and vincristine (VCT) also increased the PAI-1 concentration in the conditioned medium. PAI-1 (SERPINE1) expression was upregulated in MCF-7 cells after PTX, VBT, and VCT treatment; this increase in expression persisted for eight days. In contrast, PAI-1 production in MDA-MB-231 cells treated with PTX, VBT, or VCT did not increase with increasing PAI-1 concentration. This study demonstrated that temporary low-dose treatment with microtubule-associated anticancer drugs increased PAI-1 release from MCF-7 cells but not from MDA-MB-231 cells. These results indicate that chemotherapy against luminal A-type breast cancer using microtubule-associated drugs may cause thrombosis through the inhibition of the fibrinolytic system by PAI-1.

The influence of 4G/5G polymorphism in the plasminogen-activator-inhibitor-1 promoter on COVID-19 severity and endothelial dysfunction.

Introduction: Plasminogen activator inhibitor-1 (PAI-1) is linked to thrombosis and endothelial dysfunction in severe COVID-19. The +43 G>A PAI-1 and 4G/5G promoter polymorphism can influence PAI-1 expression. The 4G5G PAI-1 promoter gene polymorphism constitutes the 4G4G, 4G5G, and 5G5G genotypes. However, the impact of PAI-1 polymorphisms on disease severity or endothelial dysfunction remains unclear. Methods: Clinical data, sera, and peripheral blood mononuclear cells (PBMCs) of COVID-19 patients were studied. Results: Comorbidities and clinical biomarkers did not correlate with genotypes in either polymorphism. However, differences between fibrinolytic factors and interleukin-1ß (IL-1ß) were identified in genotypes of the 4G/5G but not the 43 G>A PAI polymorphism. Patients with the 4G4G genotype of the 4G/5G polymorphism showed high circulating PAI-1, mainly complexed with plasminogen activators, and low IL-1ß and plasmin levels, indicating suppressed fibrinolysis. NFκB was upregulated in PBMCs of COVID-19 patients with the 4G4G genotype. Discussion: Mechanistically, IL-1ß enhanced PAI-1 expression in 4G4G endothelial cells, preventing the generation of plasmin and cleavage products like angiostatin, soluble uPAR, and VCAM1. We identified inflammation-induced endothelial dysfunction coupled with fibrinolytic system overactivation as a risk factor for patients with the 5G5G genotype.

Assessment of the effect of unfractionated heparin administered either by intravenous infusion vs. subcutaneous injection on heparin-binding protein, and plasminogen activator inhibitor-1 in critically ill septic patients: a randomized controlled trial.

OBJECTIVE: The study compared the impact of unfractionated heparin (UFH) administered via two routes (infusion and subcutaneous injection) on heparin-binding protein (HBP) and plasminogen activator inhibitor-1 (PAI-1) levels in critically ill sepsis patients. PATIENTS AND METHODS: Forty critically ill sepsis patients were randomly assigned to receive either a low-dose intravenous infusion of UFH (500 units/hour) or subcutaneous UFH (5,000 units/8 hours) for seven days. HBP and PAI-1 were measured at baseline and on days one, two, and seven. RESULTS: Intravenous administration of UFH showed a significant reduction in percentage change of HBP compared to subcutaneous administration on days one [(-35% vs. -13%, p = 0.03*) (*indicates a significant result *p < 0.05, relative to the subcutaneous group)] and seven (-62% vs. -39%, p = 0.02*). Also, the percentage change of PAI-1 was significantly reduced in the infusion group compared to the subcutaneous group on days one (-28% vs. -3%, p = 0.008*), two (-42% vs. -3%, p = 0.001*), and seven (-62% vs. 27%, p = 0.001*), respectively. Furthermore, a significant improvement in the 14-day survival was observed in the infusion group compared to the subcutaneous group (p = 0.008*). CONCLUSIONS: Intravenous infusion was the route of choice for UFH administration in critically ill septic patients, with a promising effect on HBP, PAI-1, and survival.

Transcriptomic analysis of profibrinolytic and fibrinolytic inhibitor genes in COVID-19 patients.

The immunopathogenesis of COVID-19 infection is initiated by the entry of the SARS-CoV-2 virus into the human body through droplets, entering the lungs and binding to the ACE-2 receptor. Activated macrophages stimulate an immune and inflammatory response, leading to the activation of the coagulation cascade, including profibrinolytic and fibrinolytic inhibitor processes. One of the proteins involved in profibrinolytic is encoded by the PLAUR gene, while fibrinolytic inhibitor proteins are encoded by the A2M and SERPINE1 genes. This research aims to assess the transcriptomic analysis of genetic expression data of profibrinolytic genes, fibrinolytic inhibitor genes and their correlation with serum D-dimer levels, which describe the clinical condition of coagulation in COVID-19 patients. This cross-sectional study included 25 patients each for mild and moderate-to-severe COVID-19 at Dr. M. Djamil Padang General Hospital, Padang, Indonesia. Inter-group gene expression comparisons will be analyzed using log2 folds change, and bivariate tests will be analyzed using correlation. The results show that the PLAUR gene has higher expression in moderate-to-severe compared to mild cases. Similarly, the SERPINE1 and A2M genes expressions are higher in moderate-to-severe compared to mild cases. Furthermore, there is a significant correlation between serum D-dimer levels and profibrinolytic factor (PLAUR gene) expression in COVID-19 patients. The correlation between serum D-dimer levels with fibrinolytic inhibitor factor (SERPINE1 and A2M genes) expression was found. These conclude that there is a significant difference in the expression of the profibrinolytic and fibrinolytic inhibitor genes between mild and moderate-to-severe cases in COVID-19, demonstrating COVID-19 infection affects coagulation activities.

Association between PAI-1 4G/5G genotype and residual thrombus in acute mesenteric venous thrombosis.

OBJECTIVE: Plasminogen activator inhibitor-1 (PAI-1) is the most important inhibitor of plasminogen activator. The functional 4G/5G polymorphism of the gene coding for PAI-1 may affect PAI-1 plasmatic activity, influencing the imbalance between coagulation and fibrinolysis cascades. In this study, we investigated the association between the PAI-1 4G/5G genotype and the development and residual thrombus of acute primary mesenteric venous thrombosis (MVT). METHODS: The clinical data of 34 patients who underwent acute primary MVT were retrospectively reviewed. Fluorescence in situ hybridization was used to determine if patients had the 4G/5G polymorphism in the promoter of the PAI-1 gene. Patients were stratified according to the genotype of PAI-1. RESULTS: 11 patients (32.3%) were homozygous for the 4G genotype, 23 patients (67.6%) were non-homozygous for the 4G genotype (5G/5G). The extent of thrombosis was not correlated with the PAI-4G/5G polymorphism. After a mean follow-up of 16.6 ± 10.4 months, the 4G/4G genotype had a significantly larger thrombus burden (p < 0.05). 54% of patients in the 4G/4G genotype group had no lessening in the degree of mesenteric venous thrombosis, significantly higher than other patients (4G/5G + 5G/5G genotypes) (p < 0.05). CONCLUSION: The PAI-1 4G/4G predicts residual thrombus of mesenteric veins after the acute phase.

Blood PAI-1 and cardiovascular and metabolic risk factors among the middle-aged women from SWAN study.

The research on the role of plasminogen activator inhibitor-1 (PAI-1) in cardiovascular and metabolic diseases is insufficient. We aimed to explore whether elevated blood PAI-1 levels are significantly related to increased cardiovascular and metabolic risk factors in a midlife women population. Data were obtained from baseline characteristics in Study of Women's Health Across the Nation (SWAN) study. Multivariable linear regression models were performed to examine for the trends of associations between PAI-1 and cardiovascular and metabolic risk factors (systolic BP, diastolic BP, fasting blood glucose, insulin, HDL-C, LDL-C, TG and TC), respectively. Smooth curve demonstrated gradual upward trends on associations of blood PAI-1 levels with LDL-C, TG, TC, fasting blood glucose, insulin, systolic BP and diastolic BP (all P < 0.05) and a gradual downward trend of PAI-1 levels with HDL-C (P < 0.05). Multivariable linear regression models still indicated that increased blood PAI-1 levels were associated with higher cardiovascular and metabolic risk after confounding factors including age, race/ethnicity, ever smoked regularly, alcohol in last 24 h, menopausal status, total family income and BMI were controlled for. Moreover, we observed that the independent associations between blood levels of PAI-1 and cardiovascular and metabolic risk factors examined by stratified analysis were not influenced by age, smoking status, menopausal status and BMI, respectively. Our analysis showed that increased blood PAI-1 levels were associated with higher level for cardiovascular and metabolic risk factors which mainly causes to higher possibility of cardio-cerebrovascular diseases in a large-sample midlife women subjects.

Targeting Fibrinolytic Inhibition for Venous Thromboembolism Treatment: Overview of an Emerging Therapeutic Approach.

Venous thrombosis and pulmonary embolism (venous thromboembolism) are important causes of morbidity and mortality worldwide. In patients with venous thromboembolism, thrombi obstruct blood vessels and resist physiological dissolution (fibrinolysis), which can be life threatening and cause chronic complications. Plasminogen activator therapy, which was developed >50 years ago, is effective in dissolving thrombi but has unacceptable bleeding risks. Safe dissolution of thrombi in patients with venous thromboembolism has been elusive despite multiple innovations in plasminogen activator design and catheter-based therapy. Evidence now suggests that fibrinolysis is rigidly controlled by endogenous fibrinolysis inhibitors, including α2-antiplasmin, plasminogen activator inhibitor-1, and thrombin-activable fibrinolysis inhibitor. Elevated levels of these fibrinolysis inhibitors are associated with an increased risk of venous thromboembolism in humans. New therapeutic paradigms suggest that accelerated and effective fibrinolysis may be achieved safely by therapeutically targeting these fibrinolytic inhibitors in venous thromboembolism. In this article, we discuss the role of fibrinolytic components in venous thromboembolism and the current status of research and development targeting fibrinolysis inhibitors.

Pravastatin Protects Cytotrophoblasts from Hyperglycemia-Induced Preeclampsia Phenotype.

There are no effective therapies to prevent preeclampsia (PE). Pravastatin shows promise by attenuating processes associated with PE such as decreased cytotrophoblast (CTB) migration, aberrant angiogenesis, and increased oxidative stress. This study assesses the effects of pravastatin on hyperglycemia-induced CTB dysfunction. METHODS: Human CTB cells were treated with 100, 150, 200, 300, or 400 mg/dL glucose for 48 h. Some cells were pretreated with pravastatin (1 µg/mL), while others were cotreated with pravastatin and glucose. The expression of urokinase plasminogen activator (uPA), plasminogen activator inhibitor 1 (PAI-1) mRNA, vascular endothelial growth factor (VEGF), placenta growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and soluble endoglin (sEng) were measured. CTB migration was assayed using a CytoSelect migration assay kit. Statistical comparisons were performed using an analysis of variance with Duncan's post hoc test. RESULTS: The hyperglycemia-induced downregulation of uPA was attenuated in CTB cells pretreated with pravastatin at glucose levels > 200 mg/dL and cotreated at glucose levels > 300 mg/dL (p < 0.05). Hyperglycemia-induced decreases in VEGF and PlGF and increases in sEng and sFlt-1 were attenuated in both the pretreatment and cotreatment samples regardless of glucose dose (p < 0.05). Pravastatin attenuated hyperglycemia-induced dysfunction of CTB migration. CONCLUSIONS: Pravastatin mitigates stress signaling responses in hyperglycemic conditions, weakening processes leading to abnormal CTB migration and invasion associated with PE in pregnancy.

Sourdough Bread with Different Fermentation Times: A Randomized Clinical Trial in Subjects with Metabolic Syndrome.

The Mediterranean diet, featuring sourdough bread, shows promise in managing metabolic syndrome. This study explored the effects of two sourdough breads, with differing fermentation times but similar nutritional profiles, on inflammation, satiety, and gut microbiota composition in adults with metabolic syndrome. In a double-blind clinical trial, participants were randomized to consume either Elias Boulanger® long-fermentation (48 h) sourdough bread (EBLong) or Elias Boulanger® short-fermentation (2 h) sourdough bread (EBShort) over a two-month period. We assessed clinical parameters, inflammatory biomarkers, satiety-related hormones, and the richness and abundance of gut microbiota at baseline and follow-up. The participants included 31 individuals (mean age, 67, 51.6% female). EBShort was associated with reduced levels of soluble intercellular adhesion molecule (sICAM), and all participants, regardless of the intervention, exhibited a decrease in sICAM and diastolic pressure from baseline (p < 0.017). At follow-up, plasminogen activator inhibitor-1 (PAI-1) levels were lower in EBShort (-744 pg/mL; 95%CI: -282 to -1210 pg/mL) compared to EBLong. No differences in microbiota richness or abundance were observed. EBShort bread was effective in reducing some inflammation markers. The consumption of sourdough bread may offer potential benefits in reducing inflammation markers in individuals with metabolic syndrome; however, longer fermentation times did not show additional benefits.

Anti-Inflammatory Effect of Atorvastatin on Primary Human Endothelial Cells Incubated under Genotoxic Load.

The level of cytokine expression was measured in human coronary artery (HCAEC) and internal thoracic artery (HITAEC) endothelial cells exposed to 500 ng/ml alkylating mutagen mitomycin C (MMC) and 5 µM atorvastatin. It was found that treatment of MMC-exposed HCAEC with atorvastatin decreased secretion of macrophage migration inhibitory factor (MIF), IL-8, and IL8 gene expression, but increased the expression of SERPINE1 gene encoding the PAI-1 protein. In atorvastatin-treated HITAEC, the concentration of MIF protein and the expression of the IL8 and SERPINE1 genes were reduced. We can conclude that atorvastatin prevents proinflammatory activation of endothelial cells cultured under conditions of genotoxic load. However, the molecular mechanisms of this effect require further research.

Associations of gut microbiota features and circulating metabolites with systemic inflammation in children.

OBJECTIVE: Gut microbes and microbe-dependent metabolites (eg, tryptophan-kynurenine-serotonin pathway metabolites) have been linked to systemic inflammation, but the microbiota-metabolite-inflammation axis remains uncharacterised in children. Here we investigated whether gut microbiota features and circulating metabolites (both microbe-dependent and non-microbe-dependent metabolites) associated with circulating inflammation markers in children. METHODS: We studied children from the prospective Gen3G birth cohort who had data on untargeted plasma metabolome (n=321 children; Metabolon platform), gut microbiota (n=147; 16S rRNA sequencing), and inflammation markers (plasminogen activator inhibitor-1 (PAI-1), monocyte chemoattractant protein-1, and tumour necrosis factor-α) measured at 5-7 years. We examined associations of microbial taxa and metabolites-examining microbe-dependent and non-microbe-dependent metabolites separately-with each inflammatory marker and with an overall inflammation score (InfSc), adjusting for key confounders and correcting for multiple comparisons. We also compared the proportion of significantly associated microbe-dependent versus non-microbe-dependent metabolites, identified a priori (Human Microbial Metabolome Database), with each inflammation marker. RESULTS: Of 335 taxa tested, 149 were associated (qFDR<0.05) with at least one inflammatory marker; 10 of these were robust to pseudocount choice. Several bacterial taxa involved in tryptophan metabolism were associated with inflammation, including kynurenine-degrading Ruminococcus, which was inversely associated with all inflammation markers. Of 1037 metabolites tested, 315 were previously identified as microbe dependent and were more frequently associated with PAI-1 and the InfSc than non-microbe dependent metabolites. In total, 87 metabolites were associated (qFDR<0.05) with at least one inflammation marker, including kynurenine (positively), serotonin (positively), and tryptophan (inversely). CONCLUSION: A distinct set of gut microbes and microbe-dependent metabolites, including those involved in the tryptophan-kynurenine-serotonin pathway, may be implicated in inflammatory pathways in childhood.

The novel stimulators of feline ovarian granulosa cell functions: Monocyte chemoattractant protein-1 and plasminogen activator inhibitor-1.

The aim of the present study was to determine whether adipokines monocyte chemoattractant protein-1 (MCP-1) and plasminogen activator inhibitor-1 (PAI-1) can affect the functions of ovarian cells in cats. The addition of either MCP-1 or PAI-1 increased viability; promoted the accumulation of proliferation markers and progesterone and estradiol release; and decreased the accumulation of apoptosis markers in cultured feline granulosa cells. The present observations suggest that MCP-1 or PAI-1 can be physiological stimulators of ovarian granulosa cell functions.

Fibrinolysis associated proteins and lipopolysaccharide bioactivity in plasma and cerebrospinal fluid in multiple sclerosis.

The coagulation cascade and fibrinolysis have links with neuroinflammation and increased activation of the coagulation system has been reported in MS patients. We quantified levels of D-dimer, tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) and the bioactivity of bacterial lipopolysaccharide (LPS) in cerebrospinal fluid (CSF) and plasma from newly diagnosed untreated MS patients and controls. These molecules showed multiple correlations with each other as well as with age, HLA-DRB1*15:01, body-mass-index and CSF IgG. Our results confirm previous findings of increased plasma PAI-1 and LPS in MS patients compared to controls indicating changes in platelet function and gut permeability in MS.

Pan-cancer analysis of SERPINE1 with a concentration on immune therapeutic and prognostic in gastric cancer.

The serine protease inhibitor clade E member 1 (SERPINE1) is a key modulator of the plasminogen/plasminase system and has been demonstrated to promote tumor progression and metastasis in various tumours. However, although much literature has explored the cancer-promoting mechanism of SERPINE1, the pan-cancer analyses of its predictive value and immune response remain unexplored. The differential expression, and survival analysis of SERPINE1 expression in multiple cancers were analysed using The Cancer Genome Atlas and Genotype-Tissue Expression database. Kaplan-Meier (K-M) plotter and survival data analysis were used to analyze the prognostic value of SERPINE1 expression, including overall survival (OS), disease-specific survival, disease-free interval and progression-free interval and investigated the relationship of SERPINE1 expression with microsatellite instability. We further analysed the correlation between the expression of SERPINE1 and immune infiltration. The Kyoto Encyclopaedia of Genes and Genomes pathway was used for enrichment analysis, and the Gene Set Enrichment Analysis (GSEA) database was used to perform pathway analysis. Finally, in vitro experiments demonstrated that knockdown or overexpression of SERPINE1 could alter the proliferation and migration of gastric cancer (GC) cells. The results indicated that SERPINE1 expression levels different significantly between cancer and normal tissues, meanwhile, it was highly expressed in various cancers. By analysing online data, it has been observed that the gene SERPINE1 exhibits heightened expression levels across a variety of human cancers, significantly impacting patient survival rates. Notably, the presence of SERPINE1 was strongly associated with decrease OS and disease-free survival in individuals diagnosed with GC. Furthermore, an observed link indicates that higher levels of SERPINE expression are associated with increased infiltration of immune cells in GC. Finally, in vitro experiments showed that knockdown or overexpression of SERPINE1 inhibited the growth, and migration, of GC cells. SERPINE1expression potentially represents a novel prognostic biomarker due to its significant association with immune cell infiltration in GC. This study shows that SERPINE1 is an oncogene that participates in regulating the immune infiltration and affecting the prognosis of patients in multiple cancers, especially in GC. These findings underscore the importance of further investigating the role of SERPINE1 in cancer progression and offer a promising direction for the development of new therapeutic strategies.

Development and validation of a hypoxia- and mitochondrial dysfunction- related prognostic model based on integrated single-cell and bulk RNA sequencing analyses in gastric cancer.

Introduction: Gastric cancer (GC) remains a major global health threat ranking as the fifth most prevalent cancer. Hypoxia, a characteristic feature of solid tumors, significantly contributes to the malignant progression of GC. Mitochondria are the major target of hypoxic injury that promotes mitochondrial dysfunction during the development of cancers including GC. However, the gene signature and prognostic model based on hypoxia- and mitochondrial dysfunction-related genes (HMDRGs) in the prediction of GC prognosis have not yet been established. Methods: The gene expression profile datasets of stomach cancer patients were retrieved from The Cancer Genome Atlas and the Gene Expression Omnibus databases. Prognostic genes were selected using Least Absolute Shrinkage and Selection Operator Cox (LASSO-Cox) regression analysis to construct a prognostic model. Immune infiltration was evaluated through ESTIMATE, CIBERSORT, and ssGSEA analyses. Tumor immune dysfunction and exclusion (TIDE) and immunophenoscore (IPS) were utilized to explore implications for immunotherapy. Furthermore, in vitro experiments were conducted to validate the functional roles of HMDRGs in GC cell malignancy. Results: In this study, five HMDRGs (ZFP36, SERPINE1, DUSP1, CAV1, and AKAP12) were identified for developing a prognostic model in GC. This model stratifies GC patients into high- and low-risk groups based on median risk scores. A nomogram predicting overall survival (OS) was constructed and showed consistent results with observed OS. Immune infiltration analysis indicated that individuals in the high-risk group tend to exhibit increased immune cell infiltration. Additionally, analysis of cancer immunotherapy responses revealed that high-risk group patients exhibit poorer responses to cancer immunotherapy compared to the low-risk group. Immunohistochemistry (IHC) staining indicated that the expression levels of HMDRGs were remarkably correlated with GC, of which, SERPINE1 displayed the most pronounced up-regulation, while ZFP36 exhibited the most notable down-regulation in GC patients. Furthermore, in vitro investigation validated that SERPINE1 and ZFP36 contribute to the malignant processes of GC cells correlated with mitochondrial dysfunction. Conclusions: This study presents a novel and efficient approach to evaluate GC prognosis and immunotherapy efficacy, and also provides insights into understanding the pathogenesis of GC.

Plasma proteomic profiling reveals that SERPINE1 is a potential biomarker associated with coronary artery lesions in Kawasaki disease.

BACKGROUND: Kawasaki disease (KD) is the most common cause of acquired heart disease in childhood. Coronary artery lesions (CALs) are serious complications of KD that can result in stenosis and thrombosis, but the specific underlying pathogenic mechanisms have not been elucidated. Therefore, exploring biomarkers to help predict early CALs is urgently needed for clinical treatment. METHODS: Patients were recruited from three independent cohorts. In the discovery cohort, Data-Independent Acquisition Mass Spectrometry (DIA-MS) was performed to screen plasma proteins from healthy controls (HCs), KD patients prior to intravenous immunoglobulin (IVIG) treatment, and KD patients post-IVIG treatment. KD patients were further divided into KD patients without CALs (nCAL) and with CALs (CALs) groups. Bioinformatic analysis was carried out for the differentially expressed proteins (DEPs) and hub proteins. Candidate proteins were quantified by enzyme-linked immunosorbent assay (ELISA) in the validation cohort 1 and 2. Furthermore, candida albicans cell wall extract (CAWS)-induced KD vasculitis mice and cell models were established to investigate the expression of biomarkers identified in the aforementioned clinical cohort. RESULTS: According to the quantitative proteomics analysis, SERPINE1 was significantly increased in KD patients with CALs. Receiver operating characteristic curves (ROC) revealed that plasma SERPINE1 exhibited greater ability in predicting CALs (AUC = 0.824, P < 0.0001). After IVIG treatment, the concentrations of SERPINE1 in the nCALs group significantly decreased. However, the concentration of SERPINE1 remained persistently elevated in the CALs group. Moreover, the expression of SERPINE1 was significantly upregulated in the heart tissue of KD mice, KD plasma, or tumor necrosis factor-α (TNF-α)-stimulated human coronary artery endothelial cells (HCAECs). CONCLUSIONS: Overall, our results suggest that the plasma concentration of SERPINE1 might serve as a new potential predictive biomarker for CALs in KD patients.

SERPINE1AS2 regulates intramuscular adipogenesis by inhibiting PAI1 protein expression.

Antisense long non-coding RNAs (lncRNAs) played a crucial role in the precise regulation of essential biological processes and were abundantly present in animals. Many of these antisense lncRNAs have been identified as key roles in adipose tissue accumulation in livestock, underscoring their vital role in the regulation of animal physiology. Nonetheless, the functional roles of these antisense lncRNAs in regulating adipogenesis and the specific molecular mechanisms these processes were still unclear, which was a significant gap in current scientific research. In this study, we identified and characterized SERPINE1AS2, a novel natural antisense lncRNA, was highly expressed in the fat tissues of adult cattle and calves. Its expression gradually increased during the differentiation of intramuscular adipocytes. Through functional studies, we observed that knockdown of SERPINE1AS2 inhibited the proliferation and adipogenesis of intramuscular adipocytes, while overexpression of SERPINE1AS2 produced the opposite effect. RNA sequencing (RNA-seq) analysis following SERPINE1AS2 knockdown revealed that differential expression genes (DEGs) were significantly enriched in key signaling pathways, notably the MAPK, Wnt, and mTOR signaling pathways. Furthermore, SERPINE1AS2 interacted with Plasminogen Activator Inhibitor-1 (PAI1), forming RNA dimers through complementary base pairing and consequently influencing PAI1 expression. Interestingly, studies on PAI1 suggested that reduced expression facilitated adipogenesis and the downregulation of PAI1 alleviated the inhibitory effect of reduced SERPINE1AS2 on adipogenesis. In summary, this study suggested that SERPINE1AS2 played a crucial role in the adipogenesis of bovine intramuscular adipocytes by modulating the expression of PAI1. SERPINE1AS2 also regulated adipogenesis by engaging in the MAPK, Wnt, and mTOR signaling pathways. Our results suggested that SERPINE1AS2 had a complex regulatory mechanism on adipogenesis in intramuscular adipocytes.