Increased Neutrophil-Subset Associated With Severity/Mortality In ARDS And COVID19-ARDS Expresses The Dual Endothelin-1/VEGFsignal-Peptide Receptor (DEspR): An Actionable Therapeutic Target

Abstract Neutrophil-mediated secondary tissue injury underlies acute respiratory distress syndrome (ARDS) and progression to multi-organ-failure (MOF) and death, processes linked to severe COVID19. This ‘innocent bystander’ tissue injury arises in dysregulated hyperinflammatory states from neutrophil functions and neutrophil extracellular traps (NETs) intended to kill pathogens, but injure cells instead, causing MOF. Insufficiency of prior therapeutic approaches suggest need to identify dysregulated neutrophil-subset(s) and induce subset-specific apoptosis critical for neutrophil function-shutdown and clearance. We hypothesized that neutrophils expressing the pro-survival dual endothelin-1/signal peptide receptor, DEspR, are apoptosis-resistant just like DEspR+ cancer cells, hence comprise a consequential pathogenic neutrophil-subset in ARDS and COVID19-ARDS. Here, we report correlation of circulating DEspR+CD11b+ activated neutrophils (DESpR+actNs) and NETosing-neutrophils with severity in ARDS and in COVID19-ARDS, increased DEspR+ neutrophils and monocytes in post-mortem ARDS-patient lung sections, and neutrophil DEspR/ET1 receptor/ligand autocrine loops in severe COVID19. Unlike DEspR[-] neutrophils, ARDS patient DEspR+actNs exhibit apoptosis-resistance, which decreased upon ex vivo treatment with humanized anti-DEspR-IgG4S228P antibody, hu6g8. Ex vivo live-cell imaging of non-human primate DEspR+actNs showed hu6g8 target-engagement, internalization, and induction of apoptosis. Altogether, data differentiate DEspR+actNs as a targetable neutrophil-subset associated with ARDS and COVID19-ARDS severity, and suggest DEspR-inhibition as a potential therapeutic paradigm. 1-sentence summary: Circulating DEspR+CD11b+ neutrophils and NETosing neutrophils are associated with severity and mortality in ARDS and COVID19-ARDS.

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TLR7/8 activation in neutrophils impairs immune complex phagocytosis through shedding of FcgRIIA

Journal of Experimental Medicine ◽

10.1084/jem.20161512 ◽

2017 ◽

Vol 214 (7) ◽

pp. 2103-2119 ◽

Cited By ~ 36

Author(s):

Christian Lood ◽

Sabine Arve ◽

Jeffrey Ledbetter ◽

Keith B. Elkon

Keyword(s):

Lupus Erythematosus ◽

Ex Vivo ◽

Toll Like Receptor ◽

Therapeutic Approaches ◽

Terminal Part ◽

Tlr Signaling ◽

Effector Functions ◽

Activated Neutrophils ◽

Complement C5a

Neutrophils play a crucial role in host defense. However, neutrophil activation is also linked to autoimmune diseases such as systemic lupus erythematosus (SLE), where nucleic acid–containing immune complexes (IC) drive inflammation. The role of Toll-like receptor (TLR) signaling in processing of SLE ICs and downstream inflammatory neutrophil effector functions is not known. We observed that TLR7/8 activation leads to a furin-dependent proteolytic cleavage of the N-terminal part of FcgRIIA, shifting neutrophils away from phagocytosis of ICs toward the programmed form of necrosis, NETosis. TLR7/8-activated neutrophils promoted cleavage of FcgRIIA on plasmacytoid dendritic cells and monocytes, resulting in impaired overall clearance of ICs and increased complement C5a generation. Importantly, ex vivo derived activated neutrophils from SLE patients demonstrated a similar cleavage of FcgRIIA that was correlated with markers of disease activity, as well as complement activation. Therapeutic approaches aimed at blocking TLR7/8 activation would be predicted to increase phagocytosis of circulating ICs, while disarming their inflammatory potential.

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Tissue stress from laparoscopic grasper use and bowel injury in humans: establishing intraoperative force boundaries

BMJ Surgery, Interventions, & Health Technologies ◽

10.1136/bmjsit-2021-000084 ◽

2021 ◽

Vol 3 (1) ◽

pp. e000084

Author(s):

Amanda Farah Khan ◽

Matthew Kenneth MacDonald ◽

Catherine Streutker ◽

Corwyn Rowsell ◽

James Drake ◽

...

Keyword(s):

Small Bowel ◽

Tissue Injury ◽

Ex Vivo ◽

Gastrointestinal Surgery ◽

Convenience Sample ◽

Thickness Change ◽

Novel Device ◽

Significant Difference ◽

Laparoscopic Grasper

ObjectivesWe aim to determine what threshold of compressive stress small bowel and colon tissues display evidence of significant tissue trauma during laparoscopic surgery.DesignThis study included 10 small bowel and 10 colon samples from patients undergoing routine gastrointestinal surgery. Each sample was compressed with pressures ranging from 100 kPa to 600 kPa. Two pathologists who were blinded to all study conditions, performed a histological analysis of the tissues. Experimentation: November 2018–February 2019. Analysis: March 2019–May 2020.SettingAn inner-city trauma and ambulatory hospital with a 40-bed inpatient general surgery unit with a diverse patient population.ParticipantsPatients were eligible if their surgery procured healthy tissue margins for experimentation (a convenience sample). 26 patient samples were procured; 6 samples were unusable. 10 colon and 10 small bowel samples were tested for a total of 120 experimental cases. No patients withdrew their consent.InterventionsA novel device was created to induce compressive “grasps” to simulate those of a laparoscopic grasper. Experimentation was performed ex-vivo, in-vitro. Grasp conditions of 0–600 kPa for a duration of 10 s were used.ResultsSmall bowel (10), M:F was 7:3, average age was 54.3 years. Colon (10), M:F was 1:1, average age was 65.2 years. All 20 patients experienced a significant difference (p<0.05) in serosal thickness post-compression at both 500 and 600 kPa for both tissue types. A logistic regression analysis with a sensitivity of 100% and a specificity of 84.6% on a test set of data predicts a safety threshold of 329–330 kPa.ConclusionsA threshold was discovered that corresponded to both significant serosal thickness change and a positive histological trauma score rating. This “force limit” could be used in novel sensorized laparoscopic tools to avoid intraoperative tissue injury.

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Oestrogen protects against ischaemic acute renal failure in rats by suppressing renal endothelin-1 overproduction

Clinical Science ◽

10.1042/cs103s434s ◽

2002 ◽

Vol 103 (s2002) ◽

pp. 434S-437S ◽

Cited By ~ 27

Author(s):

Masanori TAKAOKA ◽

Mikihiro YUBA ◽

Toshihide FUJII ◽

Mamoru OHKITA ◽

Yasuo MATSUMURA

Keyword(s):

Renal Failure ◽

Renal Function ◽

Acute Renal Failure ◽

Renal Dysfunction ◽

Tissue Injury ◽

Male Rats ◽

Left Renal Artery ◽

Protective Effects ◽

Endothelin 1 ◽

Ischaemia Reperfusion

We investigated whether the treatment with 17β-oestradiol has renal protective effects in male rats with ischaemic acute renal failure (ARF). We also examined if the effect of 17β-oestradiol is accompanied by suppression of enhanced endothelin-1 production in postischaemic kidneys. Ischaemic ARF was induced by clamping the left renal artery and vein for 45min followed by reperfusion, 2 weeks after contralateral nephrectomy. Renal function parameters such as blood urea nitrogen, plasma creatinine and creatinine clearance were measured to test the effectiveness of the steroid hormone. Renal function in ARF rats markedly decreased 24h after reperfusion. The ischaemia/reperfusion-induced renal dysfunction was dose-dependently improved by pretreatment with 17β-oestradiol (20 or 100µg/kg, intravenously). Histopathological examination of the kidney of untreated ARF rats revealed severe lesions, such as tubular necrosis, proteinaceous casts in tubuli and medullary congestion, all of which were markedly improved by the higher dose of 17β-oestradiol. In addition, endothelin-1 content in the kidney after the ischaemia/reperfusion increased significantly by approx. 2-fold over sham-operated rats, and this elevation was dose-dependently suppressed by the 17β-oestradiol treatment. These results suggest that oestrogen exhibits protective effects against renal dysfunction and tissue injury induced by ischaemia/reperfusion, possibly through the suppression of endothelin-1 overproduction in postischaemic kidneys.

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The presence of the carboxy-terminal fragment of fibronectin allows maintenance of non-human primate long-term hematopoietic repopulating cells during extended ex vivo culture and transduction

Experimental Hematology ◽

10.1016/j.exphem.2003.10.003 ◽

2004 ◽

Vol 32 (2) ◽

pp. 163-170 ◽

Cited By ~ 15

Author(s):

S Sellers

Keyword(s):

Ex Vivo ◽

Terminal Fragment ◽

Ex Vivo Culture ◽

Carboxy Terminal ◽

Human Primate

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West Nile Virus-Induced Neuroinflammation: Glial Infection and Capsid Protein-Mediated Neurovirulence

Journal of Virology ◽

10.1128/jvi.02422-06 ◽

2007 ◽

Vol 81 (20) ◽

pp. 10933-10949 ◽

Cited By ~ 72

Author(s):

Guido van Marle ◽

Joseph Antony ◽

Heather Ostermann ◽

Christopher Dunham ◽

Tracey Hunt ◽

...

Keyword(s):

Endoplasmic Reticulum ◽

West Nile Virus ◽

Endoplasmic Reticulum Stress ◽

Capsid Protein ◽

Sindbis Virus ◽

Tissue Injury ◽

Ex Vivo ◽

Neuronal Loss ◽

Gene Induction ◽

West Nile

ABSTRACT West Nile virus (WNV) infection causes neurological disease at all levels of the neural axis, accompanied by neuroinflammation and neuronal loss, although the underlying mechanisms remain uncertain. Given the substantial activation of neuroinflammatory pathways observed in WNV infection, we hypothesized that WNV-mediated neuroinflammation and cell death occurred through WNV infection of both glia and neurons, which was driven in part by WNV capsid protein expression. Analysis of autopsied neural tissues from humans with WNV encephalomyelitis (WNVE) revealed WNV infection of both neurons and glia. Upregulation of proinflammatory genes, CXCL10, interleukin-1β, and indolamine-2′,3′-deoxygenase with concurrent suppression of the protective astrocyte-specific endoplasmic reticulum stress sensor gene, OASIS (for old astrocyte specifically induced substance), was evident in WNVE patients compared to non-WNVE controls. These findings were supported by increased ex vivo expression of these proinflammatory genes in glia infected by WNV-NY99. WNV infection caused endoplasmic reticulum stress gene induction and apoptosis in neurons but did not affect glial viability. WNV-infected astrocytic cells secreted cytotoxic factors, which caused neuronal apoptosis. The expression of the WNV-NY99 capsid protein in neurons and glia by a Sindbis virus-derived vector (SINrep5-WNVc) caused neuronal death and the release of neurotoxic factors by infected astrocytes, coupled with proinflammatory gene induction and suppression of OASIS. Striatal implantation of SINrep5-WNVC induced neuroinflammation in rats, together with the induction of CXCL10 and diminished OASIS expression, compared to controls. Moreover, magnetic resonance neuroimaging showed edema and tissue injury in the vicinity of the SINrep5-WNVc implantation site compared to controls, which was complemented by neurobehavioral abnormalities in the SINrep5-WNVc-implanted animals. These studies underscore the important interactions between the WNV capsid protein and neuroinflammation in the pathogenesis of WNV-induced neurological disorders.

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Neuraminidase inhibitors rewire neutrophil function in vivo in murine sepsis and ex vivo in COVID-19

10.1101/2020.11.12.379115 ◽

2020 ◽

Author(s):

Rodrigo O. Formiga ◽

Flávia C. Amaral ◽

Camila F. Souza ◽

Daniel A. G. B. Mendes ◽

Carlos W. S. Wanderley ◽

...

Keyword(s):

Sialic Acid ◽

Ex Vivo ◽

Neutrophil Function ◽

Human Neutrophils ◽

Data Sets ◽

Neuraminidase Inhibitors ◽

Severe Infections ◽

Whole Blood Cells ◽

Neutrophil Dysfunction

ABSTRACTNeutrophil overstimulation plays a crucial role in tissue damage during severe infections. Neuraminidase (NEU)-mediated cleavage of surface sialic acid has been demonstrated to regulate leukocyte responses. Here, we report that antiviral NEU inhibitors constrain host NEU activity, surface sialic acid release, ROS production, and NETs released by microbial-activated human neutrophils. In vivo, treatment with Oseltamivir results in infection control and host survival in peritonitis and pneumonia models of sepsis. Single-cell RNA sequencing re-analysis of publicly data sets of respiratory tract samples from critical COVID-19 patients revealed an overexpression of NEU1 in infiltrated neutrophils. Moreover, Oseltamivir or Zanamivir treatment of whole blood cells from severe COVID-19 patients reduces host NEU-mediated shedding of cell surface sialic acid and neutrophil overactivation. These findings suggest that neuraminidase inhibitors can serve as host-directed interventions to dampen neutrophil dysfunction in severe infections.

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