Faculty Bibliography

PURPOSE/OBJECTIVE:Pancreatic adenosquamous carcinoma (ASQ) is a rare variant with poorly defined clinical and molecular features compared to conventional pancreatic ductal adenocarcinoma (PDAC). This study aimed to characterize the clinical outcomes, genomic landscape, and spatial transcriptomic architecture of ASQ. EXPERIMENTAL DESIGN/METHODS:We retrospectively evaluated clinicopathologic features, treatment patterns, and survival of ASQ patients treated at Johns Hopkins from 2013-2023 (n=178). Genomic landscapes of ASQ (n=244) versus PDAC (n=29,021) were compared using the FoundationCore database. Surgically resected ASQ tumors (n=11 from 8 patients) were analyzed using Visium spatial transcriptomics with a comparator PDAC dataset (n=4). RESULTS:ASQ patients had poor outcomes in both resected and advanced disease. FoundationCore analysis revealed similar KRAS mutation frequency, higher MTAP loss, and enrichment of low-frequency immune biomarkers (MSI-high, PD-L1+, TMB ³10 muts/Mb) in ASQ compared with PDAC. Spatial transcriptomics revealed broadly similar immune cell proportions across subtypes, with higher regulatory T-cell abundance observed in ASQ in the context of sparse detection in PDAC. Differences in spatial co-localization patterns of immune populations were observed between ASQ and PDAC, while distance analyses within ASQ showed immune infiltrates closest to squamous regions and farthest from glandular regions. Furthermore, ASQ showed increased squamous/basal lineage expression compared with PDAC, with intratumoral squamous regions enriched for epithelial-mesenchymal transition, apical junction, inflammatory, and stress response pathways relative to the glandular niche. CONCLUSIONS:Despite shared genomic drivers with PDAC, ASQ exhibits transcriptionally distinct features with spatially organized tumor and immune heterogeneity, supporting the need for subtype-specific therapeutic strategies.

UNLABELLED:Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy characterized by an immunosuppressive tumor microenvironment enriched with cancer-associated fibroblasts (CAF). This study used a convergence approach to identify tumor cell and CAF interactions through the integration of single-cell data from human tumors with human organoid coculture experiments. Analysis of a comprehensive atlas of PDAC single-cell RNA sequencing data indicated that CAF density is associated with increased inflammation and epithelial-mesenchymal transition (EMT) in epithelial cells. Transfer learning using transcriptional data from patient-derived organoid and CAF cocultures provided in silico validation of CAF induction of inflammatory and EMT epithelial cell states. Further experimental validation in cocultures demonstrated integrin beta 1 (ITGB1) and vascular endothelial factor A (VEGFA) interactions with neuropilin-1 mediating CAF-epithelial cell cross-talk. Together, this study introduces transfer learning from human single-cell data to organoid coculture analyses for experimental validation of discoveries of cell-cell cross-talk and identifies fibroblast-mediated regulation of EMT and inflammation. SIGNIFICANCE/UNASSIGNED:Adaptation of transfer learning to relate human single-cell RNA sequencing data to organoid-CAF cocultures facilitates discovery of human pancreatic cancer intercellular interactions and uncovers cross-talk between CAFs and tumor cells through VEGFA and ITGB1.

UNLABELLED:A cultural change in medicine has placed a renewed focus on the importance of a diverse and inclusive healthcare workforce. The methods employed by anesthesiology departments in pursuit of diversity and inclusion needs to be examined. OBJECTIVE:This study's objective was to assess the frequency of established leadership infrastructures and initiatives that promote diversity and inclusion within academic anesthesiology departments. DESIGN/METHODS:This was a cross-sectional survey study. The authors emailed an electronic survey to 98 academic anesthesiology departments to assess leadership roles, dissemination platforms and initiatives used to support diversity and inclusion. SETTING/METHODS:Academic anesthesiology department in the United States with at least 60 residents. MAIN OUTCOME AND MEASURES/METHODS:The measure tested was the existence and quantification of leadership roles and initiatives directed at diversity and inclusion efforts at academic anesthesiology departments. RESULTS:The survey response rate was 49.4% (95% CI 39.3-59.6%). While 62.5% (95% CI 47.0-75.8%) of respondents reported having faculty members with a diversity and inclusion role, only 27.5% (95% CI 16.1-42.8%) reported a clearly defined leadership role such as vice-chair or committee chair. Seventy percent of respondents reported initiatives geared towards diversity using multiple platforms to showcase these initiatives. CONCLUSIONS:Based on these survey results, many anesthesia departments have developed initiatives to promote their departmental diversity. However, only a minority have established clearly defined leadership roles, which may be critical to enhance departmental success in promoting diversity and inclusion.

Previous studies implicated the neuronal guidance molecule netrin-1 in attenuating myocardial ischemia-reperfusion injury. However, the tissue-specific sources and receptor signaling events remain elusive. Neutrophils are among the first cells responding to an ischemic insult and can be associated with tissue injury or rescue. We found netrin-1 levels were elevated in the blood of patients with myocardial infarction, as well as in mice exposed to myocardial ischemia-reperfusion. Selectively increased infarct sizes and troponin levels were found in Ntn1loxP/loxP Lyz2 Cre+ mice, but not in mice with conditional netrin-1 deletion in other tissue compartments. In vivo studies using neutrophil depletion identified neutrophils as the main source for elevated blood netrin-1 during myocardial injury. Finally, pharmacologic studies using treatment with recombinant netrin-1 revealed a functional role for purinergic signaling events through the myeloid adenosine A2b receptor in mediating netrin-1-elicited cardioprotection. These findings suggest an autocrine signaling loop with a functional role for neutrophil-derived netrin-1 in attenuating myocardial ischemia-reperfusion injury through myeloid adenosine A2b signaling.

BACKGROUND:During myocardial ischemia, hypoxia-inducible factors are stabilized and provide protection from ischemia and reperfusion injury. Recent studies show that myocyte-specific hypoxia-inducible factor 2A promotes myocardial ischemia tolerance through induction of epidermal growth factor, amphiregulin. Here, the authors hypothesized that hypoxia-inducible factor 2A may enhance epidermal growth factor receptor 1 (ERBB1) expression in the myocardium that could interface between growth factors and its effect on providing tolerance to ischemia and reperfusion injury. METHODS:Human myocardial tissues were obtained from ischemic heart disease patients and normal control patients to compare ERBB1 expression. Myocyte-specific Hif2a or ErbB1 knockout mice were generated to observe the effect of Hif2a knockdown in regulating ERBB1 expression and to examine the role of ERBB1 during myocardial ischemia and reperfusion injury. RESULTS:Initial studies of myocardial tissues from patients with ischemic heart disease showed increased ERBB1 protein (1.12 ± 0.24 vs. 13.01 ± 2.20, P < 0.001). In contrast, ERBB1 transcript was unchanged. Studies using short hairpin RNA repression of Hif2A or Hif2a Myosin Cre+ mice directly implicated hypoxia-inducible factor 2A in ERBB1 protein induction during hypoxia or after myocardial ischemia, respectively. Repression of RNA-binding protein 4 abolished hypoxia-inducible factor 2A-dependent induction of ERBB1 protein. Moreover, ErbB1 Myosin Cre+ mice experienced larger infarct sizes (22.46 ± 4.06 vs. 46.14 ± 1.81, P < 0.001) and could not be rescued via amphiregulin treatment. CONCLUSIONS:These findings suggest that hypoxia-inducible factor 2A promotes transcription-independent induction of ERBB1 protein and implicates epidermal growth factor signaling in protection from myocardial ischemia and reperfusion injury.

STUDY OBJECTIVE/OBJECTIVE:To investigate the impact of utilizing a multimodal analgesia protocol to allow the implementation of Enhanced Recovery after Cardiac Surgery (ERACS) in patients requiring cardio-pulmonary bypass. DESIGN/METHODS:Retrospective analysis of patients treated with the proposed ERACS bundle in comparison to matched controls. SETTING/METHODS:Single-center study. PATIENTS/METHODS:A total of 50 patients undergoing elective cardiac surgery limited to on pump coronary artery bypass graft. MEASUREMENTS/METHODS:Perioperative outcomes of 25 patients that underwent ERACS protocol and 25 controls were measured. In-operating room (OR) extubation, total intubation time, total intra-OP fentanyl given, total post-OP morphine equivalent given, intensive care unit (ICU) length of stay (LOS), hospital LOS and post-OP complications were examined. MAIN RESULTS/RESULTS:The ERACS group and control group were equivalent with regards to age, gender, comorbidities, ASA classification and type of surgery. Mean cardiac bypass time and mean aortic clamp time were similar. Extubation in the OR was achieved for 12 patients in the ERACS group compared to 1 in the control group. Post-operative opioid consumption was lower in ERACS group (27.3 vs. 51.7 morphine equivalents, p = 0.006). Although ICU LOS and hospital LOS were shorter in the ERACS group, this did not reach significance. CONCLUSIONS:The ERACS group showed a significant decrease in opioid use and increased incidence of successful in OR extubation.

Since the discovery of hypoxia-inducible factor (HIF), numerous studies on the hypoxia signaling pathway have been performed. The role of HIF stabilization during hypoxia has been extended from the induction of a single gene erythropoietin to the upregulation of a couple of hundred downstream targets, which demonstrates the complexity and importance of the HIF signaling pathway. Accordingly, HIF and its downstream targets are emerging as novel therapeutic options to treat various organ injuries. In this review, we discuss the current understanding of HIF signaling in four different organ systems, including the heart, lung, liver, and kidney. We also discuss the divergent roles of HIF in acute and chronic disease conditions and their revealed functions. Finally, we introduce some of the efforts that are being performed to translate our current knowledge in hypoxia signaling to clinical medicine.

Perioperative organ injury has a significant impact on surgical outcomes and presents a leading cause of death in the United States. Recent research has pointed out an important role of hypoxia signaling in the protection from organ injury, including for example myocardial infarction, acute respiratory distress syndrome, acute kidney, or gut injury. Hypoxia induces the stabilization of hypoxia-inducible factors (HIFs), thereby leading to the induction of HIF target genes, which facilitates adaptive responses to low oxygen. In this review, we focus on current therapeutic strategies targeting hypoxia signaling in various organ injury models and emphasize potential clinical approaches to integrate these findings into the care of surgical patients. Conceptually, there are 2 options to target the HIF pathway for organ protection. First, drugs became recently available that promote the stabilization of HIFs, most prominently via inhibition of prolyl hydroxylase. These compounds are currently trialed in patients, for example, for anemia treatment or prevention of ischemia and reperfusion injury. Second, HIF target genes (such as adenosine receptors) could be activated directly. We hope that some of these approaches may lead to novel pharmacologic strategies to prevent or treat organ injury in surgical patients.

Myocardial ischemia-reperfusion injury (IRI) leads to the stabilization of the transcription factors hypoxia-inducible factor 1-alpha (HIF1-alpha) and hypoxia-inducible factor 2-alpha (HIF2-alpha). While previous studies implicate HIF1-alpha in cardioprotection, the role of HIF2-alpha remains elusive. Here we show that HIF2-alpha induces the epithelial growth factor amphiregulin (AREG) to elicit cardioprotection in myocardial IRI. Comparing mice with inducible deletion of Hif1a or Hif2a in cardiac myocytes, we show that loss of Hif2-alpha increases infarct sizes. Microarray studies in genetic models or cultured human cardiac myocytes implicate HIF2-alpha in the myocardial induction of AREG. Likewise, AREG increases in myocardial tissues from patients with ischemic heart disease. Areg deficiency increases myocardial IRI, as does pharmacologic inhibition of Areg signaling. In contrast, treatment with recombinant Areg provides cardioprotection and reconstitutes mice with Hif2a deletion. These studies indicate that HIF2-alpha induces myocardial AREG expression in cardiac myocytes, which increases myocardial ischemia tolerance.

MicroRNAs were discovered more than 2 decades ago and have profound impact on diverse biological processes. Specific microRNAs have important roles in modulating the innate immune response and their dysregulation has been demonstrated to contribute to inflammatory diseases. MiR-223 in particular, is very highly expressed and tightly regulated in hematopoietic cells. It functions as key modulator for the differentiation and activation of myeloid cells. The central role of miR-223 in myeloid cells, especially neutrophil and macrophage differentiation and activation has been studied extensively. MiR-223 contributes to myeloid differentiation by enhancing granulopoiesis while inhibiting macrophage differentiation. Uncontrolled myeloid activation has detrimental consequences in inflammatory disease. MiR-223 serves as a negative feedback mechanism controlling excessive innate immune responses in the maintenance of myeloid cell homeostasis. This review summarizes several topics covering the function of miR-223 in myeloid differentiation, neutrophil and macrophage functions, as well as in inflammatory diseases including acute respiratory distress syndrome and inflammatory bowel disease. In addition, nonmyeloid functions of miR-223 are also discussed in this review. Therapeutic enhancement of miR-223 to dampen inflammatory targets is also highlighted as potential treatment to control excessive innate immune responses during mucosal inflammation.