Secretion of Transforming Growth Factor-α (TGFα) by Postnatal Rabbit Alveolar Macrophages

Wagner, Carol L.; Ryan, Rita M.; Forsythe, Donna E; Keenan, Andrea; Finkelstein, Jacob N.

doi:10.1203/00006450-199507000-00009

Cited by 7 publications

(5 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The absence of these higher-molecular-mass isoforms from human milk superna tant samples as measured by Western blot analysis under reducing conditions, the mini mal staining of rainbow molecular mass markers, and negative secondary controls support the premise that these isoforms are true TGF-a-like moities reacting with the TGF-a monoclonal antibody. Similar highermolecular-mass TGF-a isoforms have been identified in the media of postnatal rabbit alveolar macrophages in our laboratory [21], It appears, therefore, that higher-molecularmass isoforms > 22 kD are secreted by HMM, and may represent either aggregation at disul fide bonds or yet another unidentified mem ber of the EGF family with a structural ho mology to TGF-a.…”

Section: Discussionmentioning

confidence: 60%

“…Macrophages isolated from other areas of the body have been shown to secrete the mature 5.6-kD isoform of TGF-a [16][17][18][19][20] and highermolecular-mass isoforms, including moieties of 14 and 30-46 kD [21]. Okada et al [11] previously reported the presence of variable higher-and lower-molecular-mass immunoreactive TGF-a isoforms in human milk and breast fluid supernatants using column chro matography.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Variation in the Biochemical Forms of Transforming Growth Factor-α Present in Human Milk and Secreted by Human Milk Macrophages

Wagner

Forsythe²,

Pittard³

1995

Neonatology

View full text Add to dashboard Cite

Objective: Transforming growth factor-α (TGF-α), present in human milk, is thought to play a significant role in postnatal gut development. Macrophages, which abound in human milk, are known to secrete various isoforms of TGF-α in other areas of the body. It was hypothesized that human milk macrophages (HMM) secrete TGF-α, and HMM are a source of TGF-α isoforms present in human milk. We sought to measure in vitro HMM TGF-α secretion, and to compare the TGF-α isoform(s) present in human milk with those secreted by HMM. Study Design: Colostrum and mature milk samples, obtained from mothers (n = 48) on postpartum days 3-30, were centrifuged. HMM were isolated, placed in culture for 24 h, and cell-free media collected. The biochemical forms of TGF-α in media in human milk supernatant samples were identified by Western blot analysis under reducing conditions. The concentration of the mature (6-kD) TGF-α isoform in those samples was quantified using a radioimmunoassay. Results: Western blot analysis under reducing conditions identified a single 6-kD TGF-α isoform in all human milk supernatant samples tested, but variable (6- and 30- to 46-kD) TGF-α isoforms in HMM media. The mean (± SE) concentration of the 6-kD TGF-α isoform found in human milk supernatants was 706 ± 88 pg/ml and 17.6 ± 2.6 pg/ml in HMM media. Conclusion: These experiments show that HMM secrete TGF-α in biochemical forms both similar to and distinct from that found in human milk supernatant.

show abstract

Section: Discussionmentioning

confidence: 60%

mentioning

confidence: 99%

Variation in the Biochemical Forms of Transforming Growth Factor-α Present in Human Milk and Secreted by Human Milk Macrophages

Wagner

Forsythe²,

Pittard³

1995

Neonatology

View full text Add to dashboard Cite

show abstract

“…TGFA encodes for the protein transforming growth factor alpha (TGF-α), a member of the epidermal growth factor which activates a signaling pathway for cell proliferation (37). In macrophages, TGF-α expression and secretion has only been reported by alveolar macrophages (38, 39). TGF-α addition to avian erythroid progenitors was shown to promote their self-renewal, and removal of TGF-α from erythroid progenitors from chick bone marrow caused them to terminally differentiate (40, 41, 42).…”

Section: Discussionmentioning

confidence: 99%

Modelling the Erythroblastic Island Niche of Dyserythropoietic Anaemia Type IV patients using Induced Pluripotent Stem Cells

May¹,

Ventura²,

Fidanza³

et al. 2023

Preprint

View full text Add to dashboard Cite

Congenital dyserythropoietic anaemia (CDA) type IV has been associated with an amino acid substitution, Glu325Lys (E325K), in the transcription factor KLF1. These patients present with a range of symptoms, including the persistence of nucleated red blood cells (RBCs) in the peripheral blood which reflects the known role for KLF1 within the erythroid cell lineage. The final stages of RBCs maturation and enucleation take place within the erythroblastic island (EBI) niche in close association with EBI macrophages. It is not known whether the detrimental effects of the E325K mutation in KLF1 are restricted to the erythroid lineage or whether deficiencies in macrophages associated with their niche also contribute to the disease pathology. To address this question, we generated an in vitro model of the human EBI niche using induced pluripotent stem cells (iPSCs) derived from a CDA type IV patient as well as iPSCs genetically modified to express an KLF1-E325K-ERT2 protein that could be activated with 4OH-tamoxifen. CDA patient-derived iPSCs and iPSCs expressing the activated KLF1-E325K-ERT2 protein showed significant deficiencies in the production of erythroid cells with associated disruption of some known KLF1 target genes. Macrophages could be generated from all iPSC lines but when the E325K-ERT2 fusion protein was activated, we noted the generation of a slightly less mature macrophage population marked by CD93. A subtle reduction in their ability to support RBC maturation was also associated with macrophages carrying the E325K-ERT2 transgene. Taken together these data support the notion that the clinically significant effects of the KLF1-E325K mutation are primarily associated with deficiencies in the erythroid lineage but that deficiencies in the niche might have the potential to exacerbate the condition. The strategy we describe provides a powerful approach to assess the effects of other mutations in KLF1 as well as other factors associated with the EBI niche.

show abstract

“…TGFA encodes for the protein transforming growth factor alpha (TGF-α), a member of the epidermal growth factor which activates a signaling pathway for cell proliferation ( Coffey et al, 1995 ). In macrophages, TGF-α expression and secretion has only been reported by alveolar macrophages ( Madtes et al, 1988 ; Wagner et al, 1995 ). TGF- α addition to avian erythroid progenitors was shown to promote their self-renewal, and removal of TGF- α from erythroid progenitors from chick bone marrow caused them to terminally differentiate ( Hayman et al, 1993 ; Schroeder et al, 1993 ; Gandrillon et al, 1999 ).…”

Section: Discussionmentioning

confidence: 99%

Modelling the erythroblastic island niche of dyserythropoietic anaemia type IV patients using induced pluripotent stem cells

May

Ventura

Fidanza

et al. 2023

Front. Cell Dev. Biol.

View full text Add to dashboard Cite

Introduction: Congenital dyserythropoietic anaemia (CDA) type IV has been associated with an amino acid substitution, Glu325Lys (E325K), in the transcription factor KLF1. These patients present with a range of symptoms, including the persistence of nucleated red blood cells (RBCs) in the peripheral blood which reflects the known role for KLF1 within the erythroid cell lineage. The final stages of RBCs maturation and enucleation take place within the erythroblastic island (EBI) niche in close association with EBI macrophages. It is not known whether the detrimental effects of the E325K mutation in KLF1 are restricted to the erythroid lineage or whether deficiencies in macrophages associated with their niche also contribute to the disease pathology.Methods: To address this question, we generated an in vitro model of the human EBI niche using induced pluripotent stem cells (iPSCs) derived from one CDA type IV patient as well as two iPSC lines genetically modified to express an KLF1-E325K-ERT2 protein that could be activated with 4OH-tamoxifen. The one patient iPSC line was compared to control lines from two healthy donors and the KLF1-E325K-ERT2 iPSC line to one inducible KLF1-ERT2 line generated from the same parental iPSCS.Results: The CDA patient-derived iPSCs and iPSCs expressing the activated KLF1-E325K-ERT2 protein showed significant deficiencies in the production of erythroid cells with associated disruption of some known KLF1 target genes. Macrophages could be generated from all iPSC lines but when the E325K-ERT2 fusion protein was activated, we noted the generation of a slightly less mature macrophage population marked by CD93. A subtle trend in their reduced ability to support RBC enucleation was also associated with macrophages carrying the E325K-ERT2 transgene.Discussion: Taken together these data support the notion that the clinically significant effects of the KLF1-E325K mutation are primarily associated with deficiencies in the erythroid lineage but it is possible that deficiencies in the niche might have the potential to exacerbate the condition. The strategy we describe provides a powerful approach to assess the effects of other mutations in KLF1 as well as other factors associated with the EBI niche.

show abstract

Secretion of Transforming Growth Factor-α (TGFα) by Postnatal Rabbit Alveolar Macrophages

Cited by 7 publications

References 28 publications

Variation in the Biochemical Forms of Transforming Growth Factor-α Present in Human Milk and Secreted by Human Milk Macrophages

Variation in the Biochemical Forms of Transforming Growth Factor-α Present in Human Milk and Secreted by Human Milk Macrophages

Modelling the Erythroblastic Island Niche of Dyserythropoietic Anaemia Type IV patients using Induced Pluripotent Stem Cells

Modelling the erythroblastic island niche of dyserythropoietic anaemia type IV patients using induced pluripotent stem cells

Contact Info

Product

Resources

About