Allele-specific N-glycosylation delays human surfactant protein B secretion in vitro and associates with decreased protein levels in vivo

An in vivo rat model was used to evaluate the effects of Escherichia coli pneumonia on lung function and surfactant in bronchoalveolar lavage (BAL). Total extracellular surfactant was increased in infected rats compared with controls. BAL phospholipid content in infected rats correlated with the severity of alveolar-capillary leak as reflected in lavage protein levels ( R2= 0.908, P < 0.0001). Western blotting showed that levels of surfactant protein (SP)-A and SP-D in BAL were significantly increased in both large and small aggregate fractions at 2 and 6 h postinstillation of E. coli. SP-B was also increased at these times in the large aggregate fraction of BAL, whereas SP-C levels were increased at 2 h and decreased at 6 h relative to controls. The small-to-large (S/L) aggregate ratio (a marker inversely proportional to surfactant function) was increased in infected rats with >50 mg total BAL protein. There was a significant correlation ( R2= 0.885, P < 0.0001) between increasing S/L ratio in BAL and pulmonary damage assessed by total protein. Pulmonary volumes, compliance, and oxygen exchange were significantly decreased in infected rats with >50 mg of total BAL protein, consistent with surfactant dysfunction. In vitro surface cycling studies with calf lung surfactant extract suggested that bacterially derived factors may have contributed in part to the surfactant alterations seen in vivo.

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Reversal of Surfactant Protein B Deficiency in Patient Specific Human Induced Pluripotent Stem Cell Derived Lung Organoids by Gene Therapy

Scientific Reports ◽

10.1038/s41598-019-49696-8 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 15

Author(s):

Sandra Lawrynowicz Leibel ◽

Alicia Winquist ◽

Irene Tseu ◽

Jinxia Wang ◽

Daochun Luo ◽

...

Keyword(s):

Stem Cell ◽

Pluripotent Stem Cell ◽

Human Lung ◽

Induced Pluripotent Stem Cell ◽

Surfactant Protein ◽

Patient Specific ◽

Surfactant Protein B ◽

Induced Pluripotent ◽

Protein B

Abstract Surfactant protein B (SFTPB) deficiency is a fatal disease affecting newborn infants. Surfactant is produced by alveolar type II cells which can be differentiated in vitro from patient specific induced pluripotent stem cell (iPSC)-derived lung organoids. Here we show the differentiation of patient specific iPSCs derived from a patient with SFTPB deficiency into lung organoids with mesenchymal and epithelial cell populations from both the proximal and distal portions of the human lung. We alter the deficiency by infecting the SFTPB deficient iPSCs with a lentivirus carrying the wild type SFTPB gene. After differentiating the mutant and corrected cells into lung organoids, we show expression of SFTPB mRNA during endodermal and organoid differentiation but the protein product only after organoid differentiation. We also show the presence of normal lamellar bodies and the secretion of surfactant into the cell culture medium in the organoids of lentiviral infected cells. These findings suggest that a lethal lung disease can be targeted and corrected in a human lung organoid model in vitro.

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Measurement of Human Surfactant Protein-B Turnover in Vivo from Tracheal Aspirates Using Targeted Proteomics

Analytical Chemistry ◽

10.1021/ac1001433 ◽

2010 ◽

Vol 82 (6) ◽

pp. 2561-2567 ◽

Cited By ~ 16

Author(s):

Daniela M. Tomazela ◽

Bruce W. Patterson ◽

Elizabeth Hanson ◽

Kimberly L. Spence ◽

Tiffany B. Kanion ◽

...

Keyword(s):

Surfactant Protein ◽

Targeted Proteomics ◽

Surfactant Protein B ◽

Tracheal Aspirates ◽

Protein B

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Dissociation of surfactant protein B from canine surfactant large aggregates during formation of small surfactant aggregates by in vitro surface area cycling

Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids ◽

10.1016/s1388-1981(99)00112-2 ◽

1999 ◽

Vol 1440 (1) ◽

pp. 49-58 ◽

Cited By ~ 12

Author(s):

Kevin Inchley ◽

Amanda Cockshutt ◽

Ruud Veldhuizen ◽

Fred Possmayer

Keyword(s):

Surface Area ◽

Surfactant Protein ◽

Surfactant Aggregates ◽

Surfactant Protein B ◽

Protein B

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Clearance of surfactant protein B from rabbit lungs

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.1995.268.4.l636 ◽

1995 ◽

Vol 268 (4) ◽

pp. L636-L641 ◽

Cited By ~ 4

Author(s):

T. Ueda ◽

M. Ikegami ◽

M. Henry ◽

A. H. Jobe

Keyword(s):

Half Life ◽

Lamellar Body ◽

Surfactant Protein ◽

Adult Rabbit ◽

Lamellar Bodies ◽

Surfactant Protein B ◽

Clearance Kinetics ◽

Protein B

To characterize the metabolism of surfactant protein B (SP-B) in vivo, we measured the clearance of SP-B from adult rabbit lungs. Purified rabbit SP-B was radiolabeled with 125I by the Bolton-Hunter method. Trace amounts of 125I-labeled SP-B mixed with [14C]dipalmitoylphosphatidylcholine (DPPC) were given intratracheally via a bronchoscope to rabbits 0-16 h before collection of alveolar washes (AW). Macrophages were recovered from AW, and lamellar bodies (LB) were isolated from lung tissue by differential centrifugation. 125I-SP-B was cleared more rapidly from the airspaces and the total lung (half-life 7 h) than was DPPC (half-life 11 h in the total lung). There was an approximately threefold accumulation of SP-B relative to saturated phosphatidylcholine in macrophages at all times. The proportion of 125I and 14C radioactivities in lamellar bodies was similar at 2 and 4 h, but there was 14-fold less 125I-SP-B than [14C]DPPC in lamellar bodies by 16 h. This loss of SP-B from the lamellar body fraction is consistent with less recycling of SP-B. The results demonstrate different clearance kinetics of these two components of surfactant and indicate a significant role of macrophages in the clearance of SP-B.

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