Du, Aolin

Cardiovascular (CV) dysfunction is common in severe acute pancreatitis (AP) and contributes substantially to mortality. Although sex differences in CV diseases are well recognized, with males generally exhibiting higher risk and poorer outcomes, their influence on AP-associated CV responses remains poorly defined. Here, we examined sex-dependent alterations in vascular integrity and cardiac function using cerulein-induced mouse models of AP. Because obesity is associated with more severe forms of AP, cerulein was used to induce mild AP in lean wild-type C57BL/6J mice and a more severe phenotype in obese C57BL/6J mice. Across both models, pancreatic injury was comparable between sexes. A modest sex difference in vascular permeability was observed in the mild but not severe AP model. In mild AP, both males and females showed similar compensatory increases in cardiac systolic function; however, in severe AP, only female mice maintained this adaptive systolic augmentation. Circulating levels of free fatty acids, reflecting systemic tissue lipolysis, were lower in females. Impaired cardiac adaptation in males was accompanied by higher levels of seven different myocardial inflammatory cytokines, as well as elevated circulating levels of angiopoietin-2 (Angpt2). While Angpt2 levels correlated with the severity of cardiac dysfunction, Angpt2 neutralization did not improve, and indeed worsened cardiac function in males. Together, these findings delineate both sex-dependent and sex-independent CV responses in mild and severe AP and identify Angpt2 as a potential compensatory cardioprotective factor under obesity-associated severe AP.

Background: Alterations in cardiovascular function are key features of severe acute pancreatitis (AP) and contribute substantially to mortality. Although sex differences in cardiovascular diseases are well recognized, with males generally exhibiting higher risk and poorer outcomes, their influence on AP-associated cardiovascular responses remains poorly defined. Therefore, we hypothesized that cerulein-induced AP causes severity-dependent and sex-specific changes in vascular integrity and cardiac function. Methods: Obesity has been associated with more severe forms of AP. Thus, mild and severe AP were induced by cerulein injections (100µg/kg/h×12) in lean (n=10 males, n=13 females) and obese (n=9 males, n=12 females) C57BL/6J mice, respectively. Vascular permeability was assessed by FITC-dextran extravasation. Cardiac function was assessed by echocardiography before and after cerulein injection. Cytokines were measured with multi-plex cytokine array and the role of angiopoietin-2 (Angpt2), an endothelial-derived regulator of vascular and cardiac responses, was evaluated using a neutralizing antibody. Results: Vascular permeability did not differ significantly between sexes in either AP model. In mild AP, males and females showed comparable increases in systolic function; however, in severe AP, only female mice maintained this adaptive systolic augmentation, assessed by fractional shortening (FS; 25.78±0.27% at baseline vs. 43.44±0.57% at endpoint, n=12, p<0.0001). This impaired cardiac adaptation in males was accompanied by increased myocardial inflammatory cytokines and elevated circulating free fatty acids. Among ten circulating cytokines measured, Angpt2 levels were significantly higher in males than females (male: 63.50±1.52ng/mL, n=9 vs. female: 41.37±2.68ng/mL, n=6, p=0.013) and were negatively correlated with systolic performance (FS; R 2 =0.75, p<0.0001), while positively associated with preload (end-diastolic volume; R 2 =0.55, p=0.0015). Unexpectedly, Angpt2 neutralization did not improve the cardiac adaptations in males and instead worsened cardiac performance as reflected by reduced FS (control IgG: 32.83±1.47%, n=4 vs. Anti-Angpt2: 22.88±0.64%, n=5, p=0.013) in severe AP. Conclusions: AP elicits both sex-dependent and sex-independent cardiovascular responses, with female mice exhibiting preserved cardiac adaptation, and Angpt2 is a potential compensatory mediator of cardiac protection in severe AP.

Introduction: Endothelial cell (EC) dysfunction, driven by comorbidities of heart failure with preserved ejection fraction (HFpEF), has emerged as a potential contributor to disease progression, yet the EC specific molecular mediators in HFpEF remain poorly defined. Purpose: To identify EC-specific molecular mediators that are involved in HFpEF and determine their functional roles in disease pathogenesis. Hypothesis: Based on omics analysis of a murine HFpEF model, we hypothesized that EC plasminogen activator inhibitor-1 (PAI-1) is a key mediator of HFpEF pathogenesis. Methods: Male RiboTagEC (Cdh5CreERT2+/Rpl22HA/+) mice were used in a HFpEF model induced by hypertensive/metabolic stresses (60% calories from lard and L-NAME 0.5 g/L in water) or administrated with normal water and diet as controls. Hearts and skeletal muscle were collected for both bulk RNA sequencing (Bulk-seq) and EC-specific translatome analysis using translating ribosome affinity purification assay followed by RNA-sequencing (TRAP-seq). The functional roles of EC PAI-1 were tested using male tamoxifen-inducible, endothelial specific PAI-1 knockout (Cdh5CreERT2+/PAI-1flox/flox, PAI-1iEC KO) and control mice (PAI-1flox/flox, PAI-1iEC+/+) subjected to HFpEF induction. Cardiac function was assessed by echocardiography, pressure–volume (PV) loop analysis, and treadmill exercise testing. Student’s t-test was used (p < 0.05). Results: Bulk-seq and EC-specific TRAP-seq identified PAI-1 as one of the most upregulated genes in both heart and skeletal muscle EC in HFpEF. Bulk-seq demonstrated a 2.5-fold change (FC, log 2 FC=1.35) increases in the heart and 12.2-fold increases (log 2 FC = 3.61) in the skeletal muscle. TRAP-seq showed a 1.75-fold change (log 2 FC=0.81) increases in the heart and 4.76-fold increases (log 2 FC = 2.25) in the skeletal muscle. These consistent findings led us to investigate the functional role of EC PAI-1 in the pathogenesis of HFpEF. With similar body weight (Control: 40±4 g, n=10; KO: 38±6 g, n=11; p=0.319) and ejection fraction (Control: 54±6 %, n=10; KO: 54±5 %, n=12; p=0.686), we found that PAI-1iEC KO mice exhibited improved diastolic function after 10 weeks of HFpEF induction. Specifically, echocardiography demonstrated a significant reduction in E/e′ in KO mice (Control: 27±4, n=10; KO: 24±3, n=12; p=0.018). PV analysis confirmed this improvement with lower end-diastolic pressure (Control: 19±2 mmHg, n=8; KO: 13±5 mmHg, n=10; p=0.009), reduced Tau (Control: 9.7±1.2 ms, n=8; KO: 8.6±1.0 ms, n=10; p=0.047), and a reduced EDPVR constant β (Control: 0.20±0.05, n=6; KO: 0.10±0.03, n=6; p=0.017). KO mice also exhibited improved treadmill running distance (Control: 179±35 m, n=10; KO: 214±40 m, n=12; p=0.043). Conclusion: Endothelial PAI-1 contributes to diastolic dysfunction and reduced exercise capacity in HFpEF. These findings highlight endothelial PAI-1 as a potential therapeutic target for HFpEF. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.

Background: Dysfunction of systemic vascular endothelial cells (ECs) is common in heart failure with preserved ejection fraction (HFpEF). We sought to determine if organ-specific EC translational heterogeneity is present in HFpEF. Using a transgenic mouse model (RiboTag EC ), we analyzed the translatome (the mRNAs bound with ribosomes) of organ-specific ECs in a mouse HFpEF model induced by hypertensive/metabolic stresses. Methods: Six-month-old male RiboTag EC ( Cdh5 CreERT2+ / Rpl22 HA/+ ) mice, expressing a hemagglutinin tag in EC ribosomal protein Rpl22, were fed a high-fat diet and L-NAME water (N=4) or a normal diet and water (N=5) for 7 weeks. Organs were collected for Translating Ribosome Affinity Purification, RNA isolation, and RNA-seq. RNA-seq data were visualized using uniform manifold approximation and projection (UMAP). Differentially expressed genes (DEGs; absolute fold change ≥ 2 and false discovery rate (FDR) adjusted p-value ≤ 0.05). Pathway enrichment analyses were conducted (Ingenuity Pathways Analysis (IPA)). Results: In UMAP, the EC translatome clustered by organ (heart, lung, skeletal muscle, and liver) highlighting organ-specific EC heterogeneity and by disease (HFpEF) status with cardiac ECs showing the most dramatic changes with HFpEF (Fig A). Cardiac ECs in HFpEF (vs Control) had 283 downregulated and 23 upregulated DEG (Fig B) out of 14,923 genes identified. There were significant differences in 142 canonical pathways (16 upregulated, 126 downregulated), including LXR/RXR activation, DHCR 24 signaling, regulation of insulin-like growth factors, eNOS signaling, acute phrase response (all down regulated) and IL-1b-mediated inhibition of RXR and unfolded protein response (both up regulated) (Fig C). Conclusion: HFpEF induction caused extensive translational changes in EC but particularly cardiac ECs. In cardiac ECs, metabolism, anti-inflammatory, vasodilation, tissue repair, and angiogenesis pathways were inhibited, while pro-inflammatory response, insulin resistance, and proteostasis pathways were activated.

Background and Objective: Decline of cardiovascular (CV) function is commonly observed in patients with severe acute pancreatitis (AP), which is associated with high mortality and morbidity. While the pathological changes in the pancreas during severe AP have been extensively studied, the impact on the CV system has not been well characterized. Furthermore, obesity is a major risk factor for severe AP. Hereby we utilized an obesity-associated mouse AP model to assess potential alterations in vascular integrity and cardiac function, two major components of circulatory failure. Methods: Wild-type male C57BL6J mice were fed a normal or a high fat (to induce obesity) diet. Both groups received intraperitoneal injection of cerulein (100 mg/kg/h x12) to induce AP. H&E and TUNEL staining of pancreas were performed to assess histology and cell death. To measure vascular integrity, we measured the leakiness of a fluorescein-conjugated dextran (70 kDa) in tissue parenchyma and serum levels of soluble vascular endothelial (VE)-cadherin, which has recently shown to be shed from endothelial cells with disrupted adherens junctions. Cardiac systolic and diastolic function were assessed by echocardiography at baseline and post-AP induction. Results: Compared to lean mice, obese mice developed more severe pancreatic edema, cell death and inflammatory cell infiltration, along with significantly increased accumulation of fluorescent dextran in multiple organs including pancreas, heart, lung, and kidney, suggesting systemic disruption of vascular integrity. Increased serum levels of soluble VE-cadherin in obese mice (vs. lean) after AP induction further supported compromised endothelial cell barrier function. At baseline, obese mice exhibited similar cardiac function to lean mice. However, obese mice, but not lean mice, developed impaired systolic and diastolic function post-AP induction, as supported by decreased ejection fraction and e’ velocity respectively. Conclusion: In this obesity-associated severe AP mouse model, systemic vascular permeability is increased, and cardiac function is substantially compromised. Systemic vascular hyperpermeability and cardiac dysfunction may represent therapeutic targets to enhance the outcomes in severe AP.