Mediator Of Disease Progression Research Articles

A2A adenosine receptor agonist reduced MMP8 expression in healthy M2-like macrophages but not in macrophages from ankylosing spondylitis patients

BackgroundAnkylosing spondylitis (AS) is an inflammatory autoimmune disease that mostly affects different joints of the body. Macrophages are the predominant cells that mediate disease progression by secreting several pro-inflammatory mediators. Different receptors are involved in macrophages’ function including the adenosine receptors (AR). Our main objective in this study was to assess the effect of applying A2A adenosine receptor agonist (CGS-21,680) on the gene expression of inflammatory mediators including bone morphogenetic proteins (BMP)-2, 4 and matrix metalloproteinases (MMP)-3, 8, 9, and 13 on the macrophages from AS patients compared to healthy macrophages.MethodsMonocytes were isolated from the whole blood of 28 individuals (AS patients and healthy controls in a 1:1 ratio). Macrophages were differentiated using macrophage colony-stimulating factor (M-CSF), and flow cytometry was performed to confirm surface markers. CGS-21,680 was used to treat cells that had been differentiated. Using SYBR green real-time PCR, relative gene expression was determined.ResultsActivating A2AAR diminished MMP8 expression in healthy macrophages while it cannot reduce MMP8 expression in patients’ macrophages. The effect of A2AAR activation on the expression of BMP2 and MMP9 reached statistical significance neither in healthy macrophages nor in the patients’ group. We also discovered a significant positive connection between MMP8 expression and patient scores on the Bath ankylosing spondylitis functional index (BASFI).ConclusionDue to the disability of A2AAR activation in the reduction of MMP8 expression in patients’ macrophages and the correlation of MMP8 expression with BASFI index in patients, these results represent defects and dysregulations in the related signaling pathway in patients’ macrophages.

Abstract A011: Emergence of persister cells following bromodomain inhibition in Ewing sarcoma

Abstract Ewing sarcoma (ES) is driven by the tumor initiating fusion EWS::FLI1 that causes widespread transcriptional dysregulation via epigenetic reprogramming. ES cells are highly plastic and heterogenous and have features of both neural crest and mesenchymal lineages. Epigenetic plasticity is well established as a mediator of disease progression and drug resistance, leading to the creation of heterogeneous tumor cell subpopulations that can initiate metastasis and relapse. Successful therapeutic strategies for metastatic or relapsed ES patients are limited and unchanged in the last three decades. Identification of new therapeutic strategies, and defining the effect of new agents on ES biology, is critical to improving patient outcomes. Given the epigenetic dependencies of ES, epigenetic modifying agents are an important class of drugs to investigate. The class of bromodomain and extra-terminal domain protein inhibitors (BETi) have shown preclinical efficacy in ES models but drug combinations will be needed. We are testing the hypothesis that transcriptional rewiring downstream of BETi will create new dependencies in ES cells that could be therapeutically exploited with biologically-defined combinations. Our studies show that the BETi, BMS-986158, the first BETi to be tested in pediatric patients, has profound cytostatic effects in preclinical ES models in vitro and in vivo. Our data further reveal that long term exposure to BMS-986158 creates a persister population of cells that reacquires proliferative capacity. We performed RNA-seq studies on parent, acutely treated (72 hours), and persister populations from three ES cell lines to define the effects of short and long term BET inhibition. Exposure to BMS-986158 led to strong inhibition of the EWS::FLI1-activated gene signature that was evident both acutely and in persister cells. Thus, despite continued inhibition of EWS::FLI1 activity, persister cells restored their ability to survive and proliferate. Gene Set Enrichment Analysis of transcripts that were significantly altered in persister cells identified gene programs involved in development and lineage commitment, including polycomb targets, suggesting that persister cells may have been rewired to more stem-like states. In addition, in two of the three cell lines, persister cells demonstrated upregulation of MYC target genes and cell cycle programs that were initially repressed by BET inhibition. Ongoing studies are investigating the molecular mechanisms by which MYC programs are reactivated in persister cells. We anticipate that epigenetic reprogramming mediates the transcriptional rewiring of MYC programs in persister cells, thereby escaping the cytostatic effects of continued BET inihbition. By defining these mechanisms we aim to identify new vulnerabilities that can be exploited in the context of BETi combination trials in the future. Citation Format: Shireen S. Ganapathi, Nicolas M. Garcia, Veerin R. Sirihorachai, Elizabeth R. Lawlor. Emergence of persister cells following bromodomain inhibition in Ewing sarcoma [abstract]. In: Proceedings of the AACR Special Conference: Sarcomas; 2022 May 9-12; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(18_Suppl):Abstract nr A011.

Abstract 3136: Molecular characterization of the effects of cancer-derived exosomes on murine lung cancer tumors

Abstract Lung cancer is the second most diagnosed type of cancer and is the leading cause of cancer-related deaths in both men and women. An estimated 235,760 new cases of lung cancer and 131,880 lung cancer deaths are expected this year accounting for 12% of new cancer cases and 22% of cancer deaths in the United States. Exosomes are secreted vesicles that contain selectively packaged biomaterials (protein, lipids, and RNA) and serve as a form of extracellular communication between cells in the tumor microenvironment. Previous studies have shown the effects of cancer-derived exosomes on specific cell types or gross tumor response in vivo yet, the competitive nature and dynamics of exosomal uptake in the tumor microenvironment remains largely unknown. This work seeks to identify molecular responses induced by cancer-derived exosomes on cells residing in the tumor microenvironment. In order to control tumor cell exposure to cancer-derived exosomes, heterogeneous ex vivo cultures derived from subcutaneous Lewis lung carcinoma (LLC) tumors in C57BL6 mice were exposed to fluorescently dyed LLC exosomes for up to 72 hours. Flow cytometric analysis was performed to identify preferential uptake of cancer exosomes into the stromal subpopulations of tumor cells. Increased uptake was observed throughout the duration of the exposure and preferential uptake was observed into neutrophils, macrophages, and endothelial cells while cancer cells, fibroblasts, and lymphocytes were underrepresented in the exosome uptaken population. Additionally, single cell RNA-sequencing was performed 24 hours post-exosomal exposure to identify transcriptional changes promoted by cancer exosome uptake. We found tumor-derived cancer cells to up-regulate transcripts associated with proliferation and down-regulated genes associated with interferon signaling in response to exosome uptake. These preliminary findings suggest that cancer-derived exosomes have targeted effects on specific cell types in the tumor microenvironment. Specifically in cancer cells, exosomal uptake can elicit protumor (cancer proliferation and immune suppression via decreased interferon signaling) effects that may serve as mediators of disease progression. An understanding of both cancer and host-derived exosomal response to disease progression may identify novel biomarkers and potential therapeutic targets previously undiscovered using canonical discovery methods. This study received funding from LLNL LDRD grant 21-LW-028. This work was conducted under the auspices of the USDOE by LLNL (DE-AC52-07NA27344). LLNL-ABS-829271 Citation Format: Nicholas R. Hum, Nicole F. Leon, Aimy Sebastian, Kelly A. Martin, Gabriela G. Loots. Molecular characterization of the effects of cancer-derived exosomes on murine lung cancer tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3136.

Abstract 1550: Elucidating the role of ADAMTS9AS2 lncRNA in ovarian cancer

Abstract Introduction: Long non-coding RNAs (lncRNAs) are important regulators of gene expression and are involved in cancer progression and metastasis. Although studies have shown that aberrant expression of lncRNAs mediates disease progression in ovarian cancer (OC), the role of lncRNA ADAMTS9-AS2 has not been well studied. Objective: To determine the role of ADAMTS9-AS2 on OC pathogenesis. Methods: We examined ADAMTS9-AS2 expression in human OC cells and tumor tissues using in situ hybridization (ISH). ADAMTS9-AS2 was overexpressed in A2780cp20 and IGROV1cp20 cells and evaluated its effects on cell proliferation, viability and apoptosis. To evaluate the role of ADAMTS9-AS2 in tumor suppression, nude mice were injected with ADAMTS9-AS2 over expressing cells. Reverse phase protein array (RPPA) was performed to identify the downstream regulators. Luciferase reporter assay was performed to confirm the interaction of targeted protein with ADAMTS9-AS2. In addition, epigenetic regulation of ADAMTS9-AS2 was studied using 5-Azacytidine. Results: A2780cp20 and IGROV1cp20 cells expressed lower amounts of ADAMTS9-AS2, while SKOV3 and PEO4 cells showed higher expression levels. ISH analysis showed dense nuclear staining of ADAMTS9-AS2 in normal fallopian tube sections, whereas OC sections showed reduced expression. Kaplan-Meier survival analysis showed that patients with high expression of ADAMTS9-AS2 had significantly better overall survival (p=0.0079) and progression-free survival (p=0.00018) than those with low ADAMTS9-AS2 expression. Overexpression of ADAMTS9-AS2 in A2780cp20 cells resulted in decreased proliferation (p<0.01) and increased apoptosis (p<0.001). ADAMTS9-AS2 overexpressing A2780cp20 and IGROV1cp20 tumor bearing mice showed significant reduction in tumor growth (p=0.002; A2780cp20, p=0.01; IGROV1cp20) when compared to control A2780cp20 and IGROV1 tumor bearing mice. RPPA analysis showed that ANNEXIN A1 was the most upregulated protein upon ADAMTS9-AS2 overexpression. We confirmed that ANNEXIN A1 expression is regulated by ADAMTS9-AS2 by silencing ADAMTS9-AS2. Further, luciferase reporter assay results confirmed the interaction between ADAMTS9-AS2 and ANNEXIN A1 promoter and silencing ADAMTS9-AS2 with siRNA abolished this effect. Consistently with our previous in vitro findings, we observed a significant increase of ANNEXIN A1 expression in the ADAMTS9-AS2 overexpressing mice, compared with the A2780cp20 control. Further, azacytidine treated A2780cp20 cells showed an increase in ADAMTS9-AS2 expression. Conclusion: ADAMTS9-AS2 acts as a tumor suppressor, by enhancing the expression of ANNEXIN A1, and thereby regulating tumor growth. Thus, ADAMTS9-AS2-ANNEXIN A1 axis may represent a novel therapeutic target in OC. Citation Format: Emine Bayraktar, Guy Katz, Dahai Jiang, Cristian Rodriguez-Aguayo, Lingegowda S. Mangala, Santosh K. Dasari, Elaine Stur, Cristina Ivan, Gabriel Lopez-Berestein, Anil K. Sood. Elucidating the role of ADAMTS9AS2 lncRNA in ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1550.

Adipose Triglyceride Lipase in Hepatic Physiology and Pathophysiology

The liver is extremely active in oxidizing triglycerides (TG) for energy production. An imbalance between TG synthesis and hydrolysis leads to metabolic disorders in the liver, including excessive lipid accumulation, oxidative stress, and ultimately liver damage. Adipose triglyceride lipase (ATGL) is the rate-limiting enzyme that catalyzes the first step of TG breakdown to glycerol and fatty acids. Although its role in controlling lipid homeostasis has been relatively well-studied in the adipose tissue, heart, and skeletal muscle, it remains largely unknown how and to what extent ATGL is regulated in the liver, responds to stimuli and regulators, and mediates disease progression. Therefore, in this review, we describe the current understanding of the structure–function relationship of ATGL, the molecular mechanisms of ATGL regulation at translational and post-translational levels, and—most importantly—its role in lipid and glucose homeostasis in health and disease with a focus on the liver. Advances in understanding the molecular mechanisms underlying hepatic lipid accumulation are crucial to the development of targeted therapies for treating hepatic metabolic disorders.

Inhibiting Fibroblast Mechanotransduction Modulates Severity of Idiopathic Pulmonary Fibrosis.

Objective: Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease that affects 63 in every 100,000 Americans. Its etiology remains unknown, although inflammatory pathways appear to be important. Given the dynamic environment of the lung, we examined the significance of mechanotransduction on both inflammatory and fibrotic signaling during IPF. Innovation: Mechanotransduction pathways have not been thoroughly examined in the context of lung disease, and pharmacologic approaches for IPF do not currently target these pathways. The interplay between mechanical strain and inflammation in pulmonary fibrosis remains incompletely understood. Approach: In this study, we used conditional KO mice to block mechanotransduction by knocking out Focal Adhesion Kinase (FAK) expression in fibroblasts, followed by induction of pulmonary fibrosis using bleomycin. We examined both normal human and human IPF fibroblasts and used immunohistochemistry, quantitative real-time polymerase chain reaction, and Western Blot to evaluate the effects of FAK inhibitor (FAK-I) on modulating fibrotic and inflammatory genes. Results: Our data indicate that the deletion of FAK in mice reduces expression of fibrotic and inflammatory genes in lungs. Similarly, mechanical straining in normal human lung fibroblasts activates inflammatory and fibrotic pathways. The FAK inhibition decreases these signals but has a less effect on IPF fibroblasts as compared with normal human fibroblasts. Conclusion: Administering FAK-I at early stages of fibrosis may attenuate the FAK-mediated fibrotic response pathway in IPF, potentially mediating disease progression.

P.024 A multi-faceted lifestyle intervention for mitochondrial A8344G associated multiple symmetric lipomatosis (MSL): a successful patient initiated novel therapy

Background: A female carrying the common MERRF mitochondrial DNA A8344G mutation had multiple symmetric lipomatosis (MSL) as the primary disease manifestation. Methods: Case report of a mitochondrial disease patient treating her severe lipomas by lifestyle modifications including a modified ketogenic diet. Results: The patient required lipoma reduction surgery after a rapid rate of lipoma progression. Following a difficult recovery, the patient independently researched an alternative therapy for her disease. The intervention was multi-faceted (dietary, physical activity, meditation) and progressive over two years. A carbohydrate reduced (5–10% of calories) modified ketogenic diet was a major part of the treatment owing to its incidental success in MSL management in her brother for management of glioblastoma multiforme. The outcome of her intervention was positive: weight loss, lipoma size reduction, improvement in physical activity/strength, laboratory markers of insulin resistance, and sense of well including a return to full time work. Conclusions: A potential non-surgical therapy for mitochondrial disease associated MSL appears feasible over the short term. The success of the lifestyle intervention in MSL therapy is unprecedented and, importantly, was fully patient initiated. This novel therapy provides potential insight into the mechanism of MSL exacerbation: suggesting insulin resistance or other lifestyle modifiable factors as mediators of disease progression.

O25 Catastrophic antiphospholipid crisis triggered by anticoagulant switch

O25 Catastrophic antiphospholipid crisis triggered by anticoagulant switch

Loss of miR-1469 expression mediates melanoma cell migration and invasion.

Tumor ulceration is considered one of the most prognostically significant findings in primary cutaneous melanoma, associated with decreased disease-free and overall survival. However, the unique features associated with ulcerated melanoma that contribute to a poor prognosis in affected patients remain poorly defined. microRNAs are small, non-coding RNAs that function to inhibit expression of specific gene targets, therefore altering the functions of cells in which they are expressed. miR-1469 is a novel miR with significantly decreased expression in ulcerated melanoma tissue relative to non-ulcerated tumors. We hypothesized that loss of miR-1469 expression in melanoma contributes to altered tumor cell functions mediating disease progression. Transfection of a miR-1469 mimic resulted in a significant reduction in the migratory and invasive capacity of the CHL1 and MEL39 melanoma cell lines (>58.1% reduction, p < 0.0332), as well as the invasive capacity of the A375 melanoma cell line (>50% reduction, p < 0.0021). Expression of myeloid cell leukemia-1 (MCL1), a miR-1469 target gene, was reduced in the A375 and MEL39 cell lines by immunoblot. No significant differences in viability, resistance to apoptotic stimuli, or proliferation were observed following transfection. These findings together demonstrate how migration and invasion are specific functions through which miR-1469 expression in melanoma cells can contribute to the differences in disease progression associated with tumor ulceration.

Equal contributions of feline immunodeficiency virus and coinfections to morbidity in African lions.

Feline immunodeficiency virus (FIV) is a pathogenic lentivirus related to human and simian immunodeficiency viruses that has been associated with AIDS-like pathologies in domestic and wild cats, as well as in hyenas. Despite known pathologies, progressive immunosuppression and ill health effects driven by these lentiviruses in association with other secondary infections remain understudied in free-ranging species. Here, the role of coinfections by gastrointestinal parasites and tick-borne hemoparasites for FIV disease progression was explored in 195 free-ranging African lions (Panthera leo) living in Kruger National Park (KNP), South Africa. Using statistical methodology, we evaluated the effects of FIV on a range of health indicators to explore how direct and indirect effects of FIV and associated coinfections align to determine lion health outcomes. Findings show direct negative effects of FIV on host immunity and nutritional status, and exacerbation of aggressive behaviors, conditions which may increase exposure/susceptibility to other secondary infections. When taken together, the contribution of coinfecting parasites to morbidity in lions is of similar magnitude as direct effects of FIV infection alone, suggesting that the particular coinfection assemblage may play a role in mediating disease progression within natural lion populations.

The Role of Extracellular Vesicles in Disease Progression and Detection of Hepatocellular Carcinoma.

Simple SummaryExtracellular vesicles (EVs) are particles naturally released from cells and mediate intercellular communication. Recently, emerging studies have shown that EVs play a crucial role in regulating progression of hepatocellular carcinoma (HCC), which is one of the leading causes of cancer-related death worldwide. With the advances of technologies in isolating EVs from patients’ blood, EVs are regarded as promising biomarkers for detecting HCC at an earlier stage. This review provides an overview of the current EVs isolation methods, the biological roles of EVs in mediating disease progression, and the feasibility of EVs’ use for detection of HCC. Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and one of the leading causes of cancer-related death worldwide. Despite the improvements in surveillance and treatment, the prognosis of HCC remains poor. Extracellular vesicles (EVs) are a heterogeneous group of phospholipid bilayer-enclosed particles circulating in the bloodstream and mediating intercellular communication. Emerging studies have shown that EVs play a crucial role in regulating the proliferation, immune escape, and metastasis of HCC. In addition, because EVs are present in the circulation at relatively early stages of disease, they are getting attention as an attractive biomarker for HCC detection. Over the past decade, dedicated efforts have been made to isolate EVs more efficiently and make them useful tools in different clinical settings. In this review article, we provide an overview of the EVs isolation methods and highlight the role of EVs as mediators in the pathogenesis and progression of HCC. Lastly, we summarize the potential applications of EVs in early-stage HCC detection.

Adrenergic-Angiogenic Crosstalk in Head and Neck Cancer: Mechanisms and Therapeutic Implications.

Head and neck squamous cell carcinomas (HNSCC) are loco-regionally aggressive tumors that often lead to debilitating changes in appearance, speech, swallowing and respiratory function in patients. It is therefore critical to develop novel targeted treatment strategies that can effectively target multiple components within the tumor microenvironment. In this regard, there has been an increased recognition of the role of neural signaling networks as mediators of disease progression in HNSCC. Here, we summarize the current knowledge on the mechanisms of adrenergic signaling in HNSCC specifically focusing on neurovascular crosstalk and the potential of targeting the adrenergic-angiogenic axis through repurposing of FDA-approved drugs against HNSCC.

Ephrin-A1 and the sheddase ADAM12 are upregulated in COVID-19

More than 3.5 million people have died globally from COVID-19, yet an effective therapy is not available. It is, therefore, important to understand the signaling pathways that mediate disease progression in order to identify new molecular targets for therapeutic development. Here, we report that the blood serum levels of ephrin-A1 and the sheddase ADAM12 were significantly elevated in COVID-19 patients treated at SUNY Downstate Hospital of Brooklyn, New York. Both ephrin-A1 and ADAM12 are known to be involved in inflammation and regulate endothelial cell permeability, thus providing a gateway to lung injury. The clinical outcome correlated with the ephrin-A1 and ADAM12 serum levels during the first week of hospitalization. In contrast, the serum levels of TNFα were elevated in only a small subset of the patients, and these same patients also had highly elevated levels of the sheddase ADAM17. These data indicate that ephrin-A1-mediated inflammatory signaling may contribute to COVID-19 disease progression more so than TNFα-mediated inflammatory signaling. They also support the notion that, in COVID-19 inflammation, ADAM12 sheds ephrin-A1, while ADAM17 sheds TNFα. Furthermore, the results suggest that elevated serum levels and activity of cytokines, such as TNFα, and other secreted inflammatory molecules, such as ephrin-A1, are not simply due to overexpression, but also to upregulation of sheddases that release them into the blood circulation. Our results identify ephrin-A1, ADAM12, and other molecules in the ephrin-A1 signaling pathway as potential pharmacological targets for treating COVID-19 inflammation.

Gene-Environmental Interactions as Metabolic Drivers of Nonalcoholic Steatohepatitis.

Nonalcoholic fatty liver disease (NAFLD) has emerged as a leading cause of chronic liver disease worldwide in the past few decades as a consequence of the global obesity epidemic and is associated with significant morbidity and mortality. NAFLD is closely associated with components of the metabolic syndrome, type 2 diabetes mellitus and cardiovascular disease, suggesting a plausible metabolic mechanistic basis. Metabolic inflexibility is considered a nidus for NAFLD pathogenesis, causing lipotoxicity, mitochondrial dysfunction and cellular stress leading to inflammation, apoptosis and fibrogenesis, thus mediating disease progression into nonalcoholic steatohepatitis (NASH) and ultimately cirrhosis. In this review, we describe they key metabolic drivers that contribute to development of NAFLD and NASH, and we explain how NASH is a metabolic disease. Understanding the metabolic basis of NASH is crucial for the prevention and treatment of this disease.

Neuroimmunology in neurological and psychiatric disorders

AbstractThe central nervous system (CNS) has long been considered as an immunological privileged site where the surveillance of the immune system does not reach out. However, it is now recognized that this CNS homeostasis is collapsed by neuroinflammation such as influx of proinflammatory factors and cells, neuronal dysfunction, and glial activation. Currently, CNS neuroinflammation is considered as a main pathomechanism to mediate disease progression in not only neurotrauma and neuroinflammatory disorders but also neurodegenerative diseases including dementia. Moreover, growing evidence indicates that chronic CNS neuroinflammation is also involved in the pathogenesis of psychiatric disorders such as autism spectrum disorders, depression, and schizophrenia. This paper reviews the current proposed pathomechanisms and therapeutic strategies of neurological and psychiatric disorders from a point of view of chronic neuroinflammation.

A target safety assessment of the potential toxicological risks of targeting plasmepsin IX/X for the treatment of malaria.

The aspartic proteases plasmepsin IX/X are important antimalarial drug targets due to their specificity to the malaria parasite and their vital role as mediators of disease progression. Focusing on parasite-specific targets where no human homologue exists reduces the possibility of on-target drug toxicity. However, there is a risk of toxicity driven by inadequate selectivity for plasmepsins IX/X in Plasmodium over related mammalian aspartic proteases. Of these, CatD/E may be of most toxicological relevance as CatD is a ubiquitous lysosomal enzyme present in most cell types and CatE is found in the gut and in erythrocytes, the clinically significant site of malarial infection. Based on mammalian aspartic protease physiology and adverse drug reactions (ADRs) to FDA-approved human immunodeficiency virus (HIV) aspartic protease inhibitors, we predicted several potential toxicities including β-cell and congenital abnormalities, hypotension, hypopigmentation, hyperlipidaemia, increased infection risk and respiratory, renal, gastrointestinal, dermatological, and other epithelial tissue toxicities. These ADRs to the HIV treatments are likely to be a result of host aspartic protease inhibition due a lack of specificity for the HIV protease; plasmepsins are much more closely related to human CatD than to HIV proteinase. Plasmepsin IX/X inhibition presents an opportunity to specifically target Plasmodium as an effective antimalarial treatment, providing adequate selectivity can be obtained. Potential plasmepsin IX/X inhibitors should be assayed for inhibitory activity against the main human aspartic proteases and particularly CatD/E. An investigative rodent study conducted early in drug discovery would serve as an initial risk assessment of the potential hazards identified.

Molecular and functional profiling of apical versus basolateral small extracellular vesicles derived from primary human proximal tubular epithelial cells under inflammatory conditions.

Proximal tubular epithelial cells (PTEC) are central players in inflammatory kidney diseases. However, the complex signalling mechanism/s via which polarized PTEC mediate disease progression are poorly understood. Small extracellular vesicles (sEV), including exosomes, are recognized as fundamental components of cellular communication and signalling courtesy of their molecular cargo (lipids, microRNA, proteins). In this study, we examined the molecular content and function of sEV secreted from the apical versus basolateral surfaces of polarized human primary PTEC under inflammatory diseased conditions. PTEC were cultured under normal and inflammatory conditions on Transwell inserts to enable separate collection and isolation of apical/basolateral sEV. Significantly increased numbers of apical and basolateral sEV were secreted under inflammatory conditions compared with equivalent normal conditions. Multi‐omics analysis revealed distinct molecular profiles (lipids, microRNA, proteins) between inflammatory and normal conditions for both apical and basolateral sEV. Biological pathway analyses of significantly differentially expressed molecules associated apical inflammatory sEV with processes of cell survival and immunological disease, while basolateral inflammatory sEV were linked to pathways of immune cell trafficking and cell‐to‐cell signalling. In line with this mechanistic concept, functional assays demonstrated significantly increased production of chemokines (monocyte chemoattractant protein‐1, interleukin‐8) and immuno‐regulatory cytokine interleukin‐10 by peripheral blood mononuclear cells activated with basolateral sEV derived from inflammatory PTEC. We propose that the distinct molecular composition of sEV released from the apical versus basolateral membranes of human inflammatory PTEC may reflect specialized functional roles, with basolateral‐derived sEV pivotal in modulating tubulointerstitial inflammatory responses observed in many immune‐mediated kidney diseases. These findings provide a rationale to further evaluate these sEV‐mediated inflammatory pathways as targets for biomarker and therapeutic development.

Sigma-2 receptor antagonists rescue neuronal dysfunction induced by Parkinson's patient brain-derived α-synuclein.

α‐Synuclein oligomers are thought to have a pivotal role in sporadic and familial Parkinson's disease (PD) and related α‐synucleinopathies, causing dysregulation of protein trafficking, autophagy/lysosomal function, and protein clearance, as well as synaptic function impairment underlying motor and cognitive symptoms of PD. Moreover, trans‐synaptic spread of α‐synuclein oligomers is hypothesized to mediate disease progression. Therapeutic approaches that effectively block α‐synuclein oligomer‐induced pathogenesis are urgently needed. Here, we show for the first time that α‐synuclein species isolated from human PD patient brain and recombinant α‐synuclein oligomers caused similar deficits in lipid vesicle trafficking rates in cultured rat neurons and glia, while α‐synuclein species isolated from non‐PD human control brain samples did not. Recombinant α‐synuclein oligomers also increased neuronal expression of lysosomal‐associated membrane protein‐2A (LAMP‐2A), the lysosomal receptor that has a critical role in chaperone‐mediated autophagy. Unbiased screening of several small molecule libraries (including the NIH Clinical Collection) identified sigma‐2 receptor antagonists as the most effective at blocking α‐synuclein oligomer‐induced trafficking deficits and LAMP‐2A upregulation in a dose‐dependent manner. These results indicate that antagonists of the sigma‐2 receptor complex may alleviate α‐synuclein oligomer‐induced neurotoxicity and are a novel therapeutic approach for disease modification in PD and related α‐synucleinopathies.

Immunological and Hematological Response in COVID-19.

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has recently and rapidly emerged and developed into a global pandemic. Through the renin-angiotensin system, the virus may impact the lung circulation, but the expression on endothelium may conduct to its activation and further systemic damage. While precise mechanisms underlying these phenomena remain to be further clarified, the understanding of the disease, its clinical course, as well as its immunological and hematological implications is of paramount importance in this phase of the pandemic. This review summarizes the evidence gathered until 12 June; electronic databases were screened for pertinent reports on coronavirus and inflammatory and hematological changes. Search was conducted by two independent investigators; keywords used were "SARS-CoV-2," "COVID-19," "inflammation," "immunological," and "therapy." The viral infection is able to trigger an excessive immune response in predisposed individuals, which can result in a "cytokine storm" that presents an hyperinflammation state able to determine tissue damage and vascular damage. An explosive production of proinflammatory cytokines such as TNF-α IL-1β and others occurs, greatly exaggerating the generation of molecule-damaging reactive oxygen species. These changes are often followed by alterations in hematological parameters. Elucidating those changes in SARS-CoV-2-infected patients could help to understand the pathophysiology of disease and may provide early clues to diagnosis. Several studies have shown that hematological parameters are markers of disease severity and suggest that they mediate disease progression. According to the available literature, the primary hematological symptoms-associated COVID-19, and which distinguish patients with severe disease from patients with nonsevere disease, are lymphocytopenia, thrombocytopenia, and a significant increase in D-dimer levels. SARS-CoV-2 infection triggers a complex response altering inflammatory, hematological, and coagulation parameters. Measuring these alterations at certain time points may help identify patients at high risk of disease progression and monitor the disease severity.

Abstract 15025: Visceral Adiposity and Muscle Composition in Heart Failure With Preserved Ejection Fraction and Association With Exercise Tolerance

Introduction: Visceral adipose tissue (AT) promotes inflammation and adverse metabolic changes that mediate disease progression in heart failure with preserved ejection fraction (HFpEF). Exercise intolerance is a hallmark of HFpEF, but little is known about its relation to the extent and distribution of AT. We characterized regional AT distribution in HFpEF patients and controls and analyzed associations with comorbidities and exercise tolerance. Methods: MRI was performed to quantify epicardial, liver, abdominal and thigh skeletal muscle AT. We assessed NYHA class, 6-minute walk distance (6MWD), and global well-being score (GWBS). Multivariable linear and logistic regression models were used, adjusted for age, sex, and body surface area. Results: We studied 55 HFpEF patients (41 women, mean age 67) and 33 controls (21 women, mean age 57). Epicardial AT (4.6 vs 3.2mm, p = 0.03), thigh intermuscular fat (11.0 vs 5.0cm 2 , p &lt; 0.01) and liver fat fraction (FF) (6.4% vs 4.1%, p = 0.04) were higher in HFpEF patients than controls. Women with HFpEF had higher abdominal (443.9 vs 297.3 cm 2 , p = 0.03) and thigh (228.6 vs 112.3 cm 2 , p &lt; 0.001) subcutaneous AT than men. Higher thigh intermuscular fat was associated with higher blood pressure (β [SE] 14.1 [3.3], p &lt; 0.001) and diabetes (β [SE] 2.6 [1.1], p = 0.02), and liver FF was associated with chronic kidney disease (β [SE] 1.6 [0.6], p = 0.01). Higher thigh intramuscular fat was associated with both higher NYHA class and shorter 6MWD, and higher thigh intermuscular AT FF was associated with higher NYHA class ( Table ). Higher epicardial AT and liver FF were associated with lower GWBS. Conclusions: HFpEF patients have increased epicardial, liver, and skeletal muscle fat compared to controls out of proportion to their body size, and adiposity was associated with worse exercise intolerance in HFpEF. These results provide the basis for further investigation into regional AT distribution in relation to HFpEF symptoms and pathophysiology.