Waldron, Richard T

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.

Abstract Background: Hemorrhagic necrotizing pancreatitis (HNP) is a highly lethal form of pancreatitis that lacks mechanism-based therapy. Intra-acinar enzyme activation is fundamental to pancreatitis initiation, yet it does not explain why only a subset of episodes progress to catastrophic hemorrhagic necrosis. Objective: To identify determinants of progression to lethal HNP and test a mechanism-based preventive intervention. Design: Using humanized trypsinogen mouse models and secretagogue regimens, we compared high-dose cerulein with low/moderate-dose cerulein and bombesin. We quantified pancreatic protease activity, performed blinded histopathologic scoring, assessed hemorrhage/vascular disruption, and evaluated enzyme localization and ductal injury by PRSS1 immunostaining. De-identified human pancreatic histology from HNP were examined. We tested a repurposed strategy using clinically approved agents for other indications: secretin to stimulate ductal fluid secretion and isosorbide mononitrate (ISMN) to promote ductal outflow via sphincter of Oddi relaxation. Results: High-dose cerulein induced robust intrapancreatic protease activation but predominantly caused edematous pancreatitis. Paradoxically, bombesin and low/moderate-dose cerulein elicited lower total pancreatic protease activity yet produced severe, frequently lethal HNP with vascular disruption and lobular ischemic necrosis. HNP was associated with intraductal enzyme accumulation and ductal injury. Secretin or ISMN alone showed limited protection, whereas combined secretin+ISMN prevented hemorrhagic necrotizing injury. Conclusion: Pancreatitis severity is determined not only by the magnitude of enzyme activation but also by where enzyme activity is exerted, implicating intraductal enzyme accumulation as a mechanistic determinant and therapeutic target in HNP. Coordinated enhancement of ductal secretion and outflow with clinically approved agents prevents HNP in vivo, supporting a translatable prevention strategy.

Coxsackievirus B3 (CVB3) is a picornavirus that causes systemic inflammatory diseases including myocarditis, pericarditis, pancreatitis, and meningoencephalitis. We have previously reported that CVB3 induces mitochondrial fission and mitophagy while inhibiting lysosomal degradation by blocking autophagosome-lysosome fusion. This promotes the release of virus-laden mitophagosomes from host cells as infectious extracellular vesicles (EVs), enabling non-lytic viral egress. Transient receptor potential vanilloid 1 (TRPV1), a heat and capsaicin-sensitive cation channel, regulates mitochondrial dynamics by inducing mitochondrial membrane depolarization and fission. In this study, we found that TRPV1 activation by capsaicin dramatically enhances CVB3 egress from host cells via EVs. Released EVs revealed increased levels of viral capsid protein VP1, mitochondrial protein TOM70, and fission protein phospho-DRP1. Moreover, these EVs were enriched in heat shock protein HSP70, suggesting its role in facilitating infectious EV release from cells. Furthermore, TRPV1 inhibition with capsazepine and SB-366791 significantly reduced viral infection in vitro. Our in vivo studies also found that SB-366791 significantly mitigates pancreatic damage and reduces viral titers in a mouse model of CVB3 pancreatitis. Given the lack of understanding regarding factors that contribute to diverse clinical manifestations of CVB3, our study highlights capsaicin and TRPV1 as potential exacerbating factors that facilitate CVB3 dissemination via mitophagy-derived EVs.

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.

Objectives Chronic pancreatitis (CP) is a chronic fibroinflammatory condition of the pancreas difficult to diagnose in early stages. Novel biomarkers useful to facilitate early diagnosis or treatment responses may be found in biofluids. Although saliva can be easily and noninvasively collected from patients, useful salivary biomarkers from CP patients have not yet been identified. Methods Here, we analyzed the proteome by quantitative proteomics, cytokine/chemokine levels by Luminex analysis, prostaglandin E2 (PGE2) levels by a mass spectrometry-based assay, and bacterial species diversity by 16S ribosomal ribonucleic acid sequencing in saliva samples from confirmed CP patients and healthy controls. Results Our results indicate the presence of various differentially expressed proteins, cytokines/chemokines, and a loss of oral bacterial diversity in the saliva of CP patients. The PGE2 levels trend toward elevation in CP patients. Area under the receiver operating characteristic curve models for proteomic, cytokine, and PGE2 assays ranged from 0.59 to 0.90. Conclusions Collectively, our studies identify a range of putative CP biomarkers and alterations in human saliva requiring further validation. The biomarker discovery approaches we used might lead to identification of biomarkers useful for CP diagnosis and monitoring.