Citations

Abstract Rationale Chronic lower respiratory diseases (CLRD), including chronic obstructive pulmonary disease (COPD), were the third-leading causes of death globally in 2019. Quantitative computed tomography (CT) measures of airway wall and lumen areas are associated with greater respiratory symptoms, reduced FEV1, accelerated lung function decline, and higher risk of incident COPD. Even in individuals without COPD, greater airway wall thickness—corresponding to smaller absolute wall and lumen areas—predicts incident COPD and CLRD-related hospitalizations and mortality. Aims To identify protein signatures and biological pathways underlying airway lumen and wall areas using cross-sectional plasma protein associations with CT measures. Methods SPIROMICS is a multicenter longitudinal case-control study that recruited 2,983 adults with COPD and a 20+ packyear smoking history and controls aged 40-80 years between 2010-2015. Standardized chest CT scans were labeled with airway measures. A total of 1,255 plasma proteins measured by SomaScan were included. Linear regression models adjusted for demographic, clinical, and imaging covariates. Significance was defined by a False Discovery Rate (FDR) p-value (q-value) <0.05 using the Benjamini-Hochberg method. Replication was performed in two external cohorts with inverse variance-weighted meta-analysis. Proteins meeting nominal replication underwent elastic net regression and pathway enrichment (Gene Ontology [GO] and Reactome). Results Among 2,065 participants with CT and proteomic data (mean age 63.2 years, 46.3% women, 61.6% with COPD), proteins meeting replication were significantly associated with lumen area (2 proteins; top hit a disintegrin and metalloproteinase with thrombospondin motifs 5, q = 0.016), wall area (3 proteins; top hit leptin, q = 0.011), and percent wall area (16 proteins; top hit roundabout homolog 2, q = 0.002). Elastic net selected 2 proteins for lumen area, 3 for wall area, and 12 for percent wall area. Pathway enrichment revealed FDR-significant pathways only for percent wall area via GO (50 pathways; top hit axogenesis) and Reactome (1 pathway; diseases of glycosylation). Conclusions This study identified distinct proteins, signatures, and biological pathways associated with CT airway measures of lumen area, wall area, and percent wall area. Proteins linked to airway lumen and wall area are involved in metabolic and vasoactive processes, while those for percent wall area are involved in vascular remodeling, cell adhesion, and extracellular matrix organization—highlighting structural pathophysiologic features of COPD. These findings may inform biomarker discovery and prediction of disease onset and progression. This abstract is funded by: Funding: Daniel E. Guzman, MD, MSE was funded by T32-HL144442. SPIROMICS was supported by contracts from the NIH/NHLBI (HHSN268200900013C, HHSN268200900014C, HHSN268200900015C, HHSN268200900016C, HHSN268200900017C, HHSN268200900018C, HHSN268200900019C, HHSN268200900020C, 75N92024D00012), grants from the NIH/NHLBI (U01HL137880, U24HL141762, R01HL182622, R01HL144718, and R01HL093081), and supplemented by contributions made through the Foundation for the NIH and the COPD Foundation from Amgen; AstraZeneca/MedImmune; Bayer; Bellerophon Therapeutics; Boehringer-Ingelheim Pharmaceuticals, Inc.; Bristol Myers Squibb; Chiesi Farmaceutici S.p.A.; Forest Research Institute, Inc.; Genentech; GlaxoSmithKline; Grifols Therapeutics, Inc.; Ikaria, Inc.; MGC Diagnostics; Novartis Pharmaceuticals Corporation; Nycomed GmbH; Polarean; ProterixBio; Regeneron Pharmaceuticals, Inc.; Sanofi; Sunovion; Takeda Pharmaceutical Company; Theravance Biopharma; Verona; and Mylan/Viatris.

Light chain (LC) amyloidosis (AL) is a systemic amyloidosis associated with significant morbidity and mortality. Current treatment involves depletion of LC producing cells but patients with advanced disease are usually intolerant of chemotherapy and autologous stem cell transplantation, with no treatment available to directly address the tissue pathology of LC. Microvascular injury may be important in it spathobiology. Our overall objective is to discover strategies to ameliorate LC‐mediated injury at the level of endothelial cell death and dysfunction. We tested the hypothesis that nanoliposomes containing monosialoganglioside, phosphatidylcholine and cholesterol (NLGM1) are capable of protecting human endothelial cells from LC‐mediated injury by hormetic induction of the nuclear factor (erythroid‐derived 2)‐like (Nrf2) oxidative defense pathway. Human umbilical vein endothelial cells (HUVEC) were exposed to LC (purified from the urine of 2 AL patients with cardiac involvement, 20μg/ml) for 18–20 hours either with or without co‐treatment with NLGM1 (given at 1:10 mass ratio to LC). Using a fluorescent probe for peroxynitrite, we found that LC caused a 51.2% (p<0.01) increase in peroxynitrite production with a coincident 33% (p<0.01) decrease in cell viability as measured by Calcein‐AM fluorescence. However, in samples that were given NLGM1 and LC, peroxynitrite was diminished and cell viability was preserved to near control levels. Interestingly, in HUVEC that were treated with NLGM1 alone, we noticed a4‐fold increase in Nrf2 gene expression (p<0.05) and in antioxidant enzymes such as heme oxygenase 1 (HO‐1) and NAD(P)H quinone oxioreductase 1 (NQO1)(119‐fold, p<0.05; and 5‐fold, p<0.01 respectively). Similarly, we found significant upregulation of Nrf2, HO‐1 and NQO1 proteins in response to NLGM1 treatment. To determine if induction of HO‐1 and NQO1 by NLGM1 were dependent on Nrf2 activation, we knocked down Nrf2 using specific siRNAs. We were able to reduce Nrf2 gene expression in HUVEC by 41%. HUVEC treated with control siRNA demonstrated a 9.4‐fold increase in HO‐1 (p<0.05)and a 3.8‐fold increase in NQO1 (p<0.05) gene expression, whereas cell streated with Nrf2‐specific siRNAs had blunted NLGM1‐mediated increases to 3.0‐fold and 1.3‐fold for HO‐1 and NQO1 ( p<0.001 and p<0.05 vs. control siRNA ), respectively. Nrf2 knockdown abolished the protective effect of NLGM1 on HUVEC viability; Nrf‐2 siRNA treated cells exposed to LC and NLGM1 demonstrated 30% reduction in viability (p<0.05) similar to the 28% reduction in control siRNA‐treated cells exposed to LC; control siRNA‐treated cells exposed to LC and NLGM1 demonstrated no difference in viability versus those exposed to vehicle. Presently, we show that NLGM1 preserve endothelial cell viability and reduce peroxynitrite production in HUVEC exposed to LC proteins. We further demonstrate that NLGM1 has the potential to modulate Nrf2 antioxidant defense pathway and is likely a relevant protective mechanism against nitrative stress generated by LC exposure. When considered together, these findings hint at a novel potential therapeutic approach to mitigate the pathobiology of AL. Support or Funding Information Funding: Veterans Affairs Merit grant (I01BX007080), National Institutes Health (NIA R21AG044723, GM RO1 071514), Amyloidosis Foundation, American Heart Association 0855683G

Background Light chain amyloidosis (AL) is associated with high mortality, especially in patients with advanced cardiovascular involvement. It is caused by toxicity of misfolded light chain proteins ( LC ) in vascular, cardiac, and other tissues. There is no treatment to reverse LC tissue toxicity. We tested the hypothesis that nanoliposomes composed of monosialoganglioside, phosphatidylcholine, and cholesterol (GM1 ganglioside–containing nanoliposomes [ NLGM 1]) can protect against LC ‐induced human microvascular dysfunction and assess mechanisms behind the protective effect. Methods and Results The dilator responses of ex vivo abdominal adipose arterioles from human participants without AL to acetylcholine and papaverine were measured before and after exposure to LC (20 μg/mL) with or without NLGM 1 (1:10 ratio for LC : NLGM 1 mass). Human umbilical vein endothelial cells were exposed for 18 to 20 hours to vehicle, LC with or without NLGM 1, or NLGM 1 and compared for oxidative and nitrative stress response and cellular viability. LC impaired arteriole dilator response to acetylcholine, which was restored by co‐treatment with NLGM 1. LC decreased endothelial cell nitric oxide production and cell viability while increasing superoxide and peroxynitrite; these adverse effects were reversed by NLGM 1. NLGM 1 increased endothelial cell protein expression of antioxidant enzymes heme oxygenase 1 and NAD (P)H quinone dehydrogenase 1 and increased nuclear factor, erythroid 2 like 2 (Nrf‐2) protein. Nrf‐2 gene knockdown reduced antioxidant stress response and reversed the protective effects of NLGM 1. Conclusions NLGM1 protects against LC ‐induced human microvascular endothelial dysfunction through increased nitric oxide bioavailability and reduced oxidative and nitrative stress mediated by Nrf‐2–dependent antioxidant stress response. These findings point to a potential novel therapeutic approach for light chain amyloidosis.