title: Polyamines are present in mast cell secretory granules and are important for granule homeostasis.
abstract: BACKGROUND
  Mast cell secretory granules accommodate a large number of components, many of which interact with highly sulfated serglycin proteoglycan (PG) present within the granules. Polyamines (putrescine, spermidine and spermine) are absolutely required for the survival of the vast majority of living cells. Given the reported ability of polyamines to interact with PGs, we investigated the possibility that polyamines may be components of mast cell secretory granules.
  
  
  RESULTS
  Spermidine was released by mouse bone marrow derived mast cells (BMMCs) after degranulation induced by IgE/anti-IgE or calcium ionophore A23187. Additionally, both spermidine and spermine were detected in isolated mouse mast cell granules. Further, depletion of polyamines by culturing BMMCs with α-difluoromethylornithine (DFMO) caused aberrant secretory granule ultrastructure, impaired histamine storage, reduced serotonin levels and increased β-hexosaminidase content. A proteomic approach revealed that DFMO-induced polyamine depletion caused an alteration in the levels of a number of proteins, many of which are connected either with the regulated exocytosis or with the endocytic system.
  
  
  CONCLUSIONS
  Taken together, our results show evidence that polyamines are present in mast cell secretory granules and, furthermore, indicate an essential role of these polycations during the biogenesis and homeostasis of these organelles.
authors.affiliation: Department of Molecular Biology and Biochemistry, and CIBER de Enfermedades Raras (CIBER-ER), Faculty of Sciences, University of Málaga, Málaga, Spain.
authors.forename: Gianni
authors.initials: G
authors.lastname: García-Faroldi
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Rodríguez
authors.forename: José L
authors.initials: JL
authors.lastname: Urdiales
authors.forename: José M
authors.initials: JM
authors.lastname: Pérez-Pomares
authors.forename: José C
authors.initials: JC
authors.lastname: Dávila
authors.forename: Gunnar
authors.initials: G
authors.lastname: Pejler
authors.forename: Francisca
authors.initials: F
authors.lastname: Sánchez-Jiménez
authors.forename: Ignacio
authors.initials: I
authors.lastname: Fajardo
mesh_terms: D000818:Animals; D015153:Blotting, Western; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D000001:Calcimycin / Q000494:pharmacology; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D015550:Cell Degranulation; D002478:Cells, Cultured; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D006706:Homeostasis; D007476:Ionophores / Q000494:pharmacology; D008407:Mast Cells / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D046529:Microscopy, Electron, Transmission; D000070796:Perilipin-3; D011073:Polyamines / Q000378:metabolism*; D040901:Proteomics / Q000379:methods; D020133:Reverse Transcriptase Polymerase Chain Reaction; D022142:Secretory Vesicles / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D013095:Spermidine / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D007476:Ionophores; D000070796:Perilipin-3; C523440:Plin3 protein, mouse; D011073:Polyamines; D000001:Calcimycin; D013095:Spermidine