Related Experiment Videos
Proteolytic cleavage confers nitric oxide synthase inducing activity upon prolactin
A M Corbacho1, G Nava, J P Eiserich
1Centro de Neurobiologia, Universidad Nacional Autónoma de México, 76001 Querétaro, Qro, México.
The Journal of Biological Chemistry
|May 2, 2000
Summary
The 16-kDa N-terminal fragment of prolactin (16K-PRL) induces nitric oxide production in lung cells, distinct from full-length prolactin. This finding suggests a new role for prolactin in inflammatory and immune responses.
Area of Science:
- Endocrinology
- Immunology
- Cell Biology
Background:
- Prolactin (PRL) has diverse biological actions beyond milk secretion.
- Proteolytic cleavage of PRL generates fragments with unique functions.
- The 16-kDa N-terminal fragment of PRL (16K-PRL) is known to inhibit angiogenesis.
Purpose of the Study:
- To investigate novel biological functions of 16K-PRL.
- To determine if 16K-PRL influences nitric oxide (*NO) production.
- To explore the role of 16K-PRL in pulmonary cells and inflammatory processes.
Main Methods:
- Treatment of pulmonary fibroblasts and alveolar type II cells with 16K-PRL and full-length PRL.
- Measurement of inducible nitric oxide synthase (iNOS) expression and *NO production.
- Investigation of PRL gene expression and endogenous 16K-PRL production in pulmonary fibroblasts.
Main Results:
- 16K-PRL, but not full-length PRL, significantly promoted iNOS expression and *NO production.
- This effect was comparable in potency to pro-inflammatory cytokines.
- Pulmonary fibroblasts express the PRL gene and produce 16K-PRL endogenously, suggesting autocrine/paracrine roles.
- 16K-PRL acts via a receptor distinct from known PRL receptors.
Conclusions:
- Proteolytic cleavage of PRL generates a fragment (16K-PRL) with potent iNOS-inducing activity.
- 16K-PRL plays a role in regulating *NO production in lung cells.
- This pathway suggests a novel function for PRL in inflammatory and immune processes.