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Browsing by Author "Sun, Xiaoguang"
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Item A cortactin CTTN coding SNP contributes to lung vascular permeability and inflammatory disease severity in African descent subject(Elsevier, 2022) Belvitch, Patrick; Casanova, Nancy; Sun, Xiaoguang; Camp, Sara M.; Sammani, Saad; Brown, Mary E.; Mascarhenas, Joseph; Lynn, Heather; Adyshev, Djanybek; Siegler, Jessica; Desai, Ankit; Seyed-Saadat, Laleh; Rizzo, Alicia; Bime, Christian; Shekhawat, Gajendra S.; Dravid, Vinayak P.; Reilly, John P.; Jones, Tiffanie K.; Feng, Rui; Letsiou, Eleftheria; Meyer, Nuala J.; Ellis, Nathan; Garcia, Joe G. N.; Dudek, Steven M.; Medicine, School of MedicineThe cortactin gene (CTTN), encoding an actin-binding protein critically involved in cytoskeletal dynamics and endothelial cell (EC) barrier integrity, contains single nucleotide polymorphisms (SNPs) associated with severe asthma in Black patients. As loss of lung EC integrity is a major driver of mortality in the Acute Respiratory Distress Syndrome (ARDS), sepsis, and the acute chest syndrome (ACS), we speculated CTTN SNPs that alter EC barrier function will associate with clinical outcomes from these types of conditions in Black patients. In case-control studies, evaluation of a nonsynonymous CTTN coding SNP Ser484Asn (rs56162978, G/A) in a severe sepsis cohort (725 Black subjects) revealed significant association with increased risk of sepsis mortality. In a separate cohort of sickle cell disease (SCD) subjects with and without ACS (177 SCD Black subjects), significantly increased risk of ACS and increased ACS severity (need for mechanical ventilation) was observed in carriers of the A allele. Human lung EC expressing the cortactin S484N transgene exhibited: (i) delayed EC barrier recovery following thrombin-induced permeability; (ii) reduced levels of critical Tyr486 cortactin phosphorylation; (iii) inhibited binding to the cytoskeletal regulator, nmMLCK; and (iv) attenuated EC barrier-promoting lamellipodia dynamics and biophysical responses. ARDS-challenged Cttn+/- heterozygous mice exhibited increased lung vascular permeability (compared to wild-type mice) which was significantly attenuated by IV delivery of liposomes encargoed with CTTN WT transgene but not by CTTN S484N transgene. In summary, these studies suggest that the CTTN S484N coding SNP contributes to severity of inflammatory injury in Black patients, potentially via delayed vascular barrier restoration.Item Endothelial eNAMPT amplifies pre-clinical acute lung injury: efficacy of an eNAMPT-neutralising monoclonal antibody(European Respiratory Society, 2021-05-06) Quijada, Hector; Bermudez, Tadeo; Kempf, Carrie L.; Valera, Daniel G.; Garcia, Alexander N.; Camp, Sara M.; Song, Jin H.; Franco, Evelyn; Burt, Jessica K.; Sun, Belinda; Mascarenhas, Joseph B.; Burns, Kimberlie; Gaber, Amir; Oita, Radu C.; Reyes Hernon, Vivian; Barber, Christy; Moreno-Vinasco, Liliana; Sun, Xiaoguang; Cress, Anne E.; Martin, Diego; Liu, Zhonglin; Desai, Ankit A.; Natarajan, Viswanathan; Jacobson, Jeffrey R.; Dudek, Steven M.; Bime, Christian; Sammani, Saad; Garcia, Joe G.N.; Medicine, School of MedicineRationale: The severe acute respiratory syndrome coronavirus 2/coronavirus disease 2019 pandemic has highlighted the serious unmet need for effective therapies that reduce acute respiratory distress syndrome (ARDS) mortality. We explored whether extracellular nicotinamide phosphoribosyltransferase (eNAMPT), a ligand for Toll-like receptor (TLR)4 and a master regulator of innate immunity and inflammation, is a potential ARDS therapeutic target. Methods: Wild-type C57BL/6J or endothelial cell (EC)-cNAMPT -/- knockout mice (targeted EC NAMPT deletion) were exposed to either a lipopolysaccharide (LPS)-induced ("one-hit") or a combined LPS/ventilator ("two-hit")-induced acute inflammatory lung injury model. A NAMPT-specific monoclonal antibody (mAb) imaging probe (99mTc-ProNamptor) was used to detect NAMPT expression in lung tissues. Either an eNAMPT-neutralising goat polyclonal antibody (pAb) or a humanised monoclonal antibody (ALT-100 mAb) were used in vitro and in vivo. Results: Immunohistochemical, biochemical and imaging studies validated time-dependent increases in NAMPT lung tissue expression in both pre-clinical ARDS models. Intravenous delivery of either eNAMPT-neutralising pAb or mAb significantly attenuated inflammatory lung injury (haematoxylin and eosin staining, bronchoalveolar lavage (BAL) protein, BAL polymorphonuclear cells, plasma interleukin-6) in both pre-clinical models. In vitro human lung EC studies demonstrated eNAMPT-neutralising antibodies (pAb, mAb) to strongly abrogate eNAMPT-induced TLR4 pathway activation and EC barrier disruption. In vivo studies in wild-type and EC-cNAMPT -/- mice confirmed a highly significant contribution of EC-derived NAMPT to the severity of inflammatory lung injury in both pre-clinical ARDS models. Conclusions: These findings highlight both the role of EC-derived eNAMPT and the potential for biologic targeting of the eNAMPT/TLR4 inflammatory pathway. In combination with predictive eNAMPT biomarker and NAMPT genotyping assays, this offers the opportunity to identify high-risk ARDS subjects for delivery of personalised medicine.