title: Characterization of secretomes provides evidence for adipose-derived mesenchymal stromal cells subtypes.
abstract: BACKGROUND
  This study was aimed at deciphering the secretome of adipose-derived mesenchymal stromal cells (ADSCs) cultured in standard and hypoxic conditions to reveal proteins, which may be responsible for regenerative action of these cells.
  
  
  METHODS
  Human ADSCs were isolated from 10 healthy donors and cultured for 3-4 passages. Cells were serum deprived and cell purity was assessed using multiple cell surface markers. Conditioned media was collected and analyzed using LC-MS with a focus on characterizing secreted proteins.
  
  
  RESULTS
  Purity of the ADSC assessed as CD90+/CD73+/CD105+/CD45-/CD31- cells was greater than 99 % and viability was greater than 97 %. More than 600 secreted proteins were detected in conditioned media of ADSCs. Of these 100 proteins were common to all cultures and included key molecules involved in tissue regeneration such as collagens and collagen maturation enzymes, matrix metalloproteases, matricellular proteins, macrophage-colony stimulating factor and pigment epithelium derived factor. Common set of proteins also included molecules, which contribute to regenerative processes but were not previously associated with ADSCs. These included olfactomedin-like 3, follistatin-like 1 and prosaposin. In addition, ADSCs from the different subjects secreted proteins, which were variable between different cultures. These included proteins with neurotrophic activities, which were not previously associated with ADSCs, such as mesencephalic astrocyte-derived neurotrophic factor, meteorin and neuron derived neurotrophic factor. Hypoxia resulted in secretion of 6 proteins, the most prominent included EGF-like repeats and discoidin I-like domains 3, adrenomedullin and ribonuclease 4 of RNase A family. It also caused the disappearance of 8 proteins, including regulator of osteogenic differentiation cartilage-associated protein.
  
  
  CONCLUSIONS
  Human ADSCs with CD90+/CD73+/CD105+/CD45-/CD31-/PDGFRβ+/NG2+/CD146+(-) immunophenotype secrete a large array of proteins, the most represented group is comprised of extracellular matrix components. Number of secreted proteins is largely unaffected by prolonged hypoxia. Variability in the secretion of several proteins from cultured ADSCs of individual subjects suggests that these cells exist as a heterogeneous population containing functionally distinct subtypes, which differ in numbers between donors.
authors.affiliation: Faculty of Medicine, Lomonosov Moscow State University, 31-5, Lomonosovsky av, Moscow, 119191, Russia. n_i_kalinina@mail.ru.
authors.forename: Natalia
authors.initials: N
authors.lastname: Kalinina
authors.affiliation: Department of Molecular Biology and Genetics, SRI of Physical-Chemical Medicine, 1a, Malaya Pirogovskaya, Moscow, 119435, Russia. harlampieva_d@mail.ru.
authors.forename: Daria
authors.initials: D
authors.lastname: Kharlampieva
authors.affiliation: Department of Molecular Biology and Genetics, SRI of Physical-Chemical Medicine, 1a, Malaya Pirogovskaya, Moscow, 119435, Russia. marina.loguinova@mail.ru.
authors.forename: Marina
authors.initials: M
authors.lastname: Loguinova
authors.affiliation: Department of Molecular Biology and Genetics, SRI of Physical-Chemical Medicine, 1a, Malaya Pirogovskaya, Moscow, 119435, Russia. ivan.butenko@gmail.com.
authors.forename: Ivan
authors.initials: I
authors.lastname: Butenko
authors.affiliation: Department of Molecular Biology and Genetics, SRI of Physical-Chemical Medicine, 1a, Malaya Pirogovskaya, Moscow, 119435, Russia. nikitishena@mail.ru.
authors.forename: Olga
authors.initials: O
authors.lastname: Pobeguts
authors.affiliation: Faculty of Medicine, Lomonosov Moscow State University, 31-5, Lomonosovsky av, Moscow, 119191, Russia. efimenkoan@gmail.com.
authors.forename: Anastasia
authors.initials: A
authors.lastname: Efimenko
authors.affiliation: Faculty of Medicine, Lomonosov Moscow State University, 31-5, Lomonosovsky av, Moscow, 119191, Russia. lyly.ag@gmail.com.
authors.forename: Luidmila
authors.initials: L
authors.lastname: Ageeva
authors.affiliation: Faculty of Medicine, Lomonosov Moscow State University, 31-5, Lomonosovsky av, Moscow, 119191, Russia. sharonov@gmail.com.
authors.forename: George
authors.initials: G
authors.lastname: Sharonov
authors.affiliation: Department of Molecular Biology and Genetics, SRI of Physical-Chemical Medicine, 1a, Malaya Pirogovskaya, Moscow, 119435, Russia. ischenko.dmitry@gmail.com.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Ischenko
authors.affiliation: Department of Molecular Biology and Genetics, SRI of Physical-Chemical Medicine, 1a, Malaya Pirogovskaya, Moscow, 119435, Russia. exappeal@gmail.com.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Alekseev
authors.affiliation: Faculty of Medicine, Lomonosov Moscow State University, 31-5, Lomonosovsky av, Moscow, 119191, Russia. o_grigorieva@list.ru.
authors.forename: Olga
authors.initials: O
authors.lastname: Grigorieva
authors.affiliation: Faculty of Medicine, Lomonosov Moscow State University, 31-5, Lomonosovsky av, Moscow, 119191, Russia. veroniks@mail.ru.
authors.forename: Veronika
authors.initials: V
authors.lastname: Sysoeva
authors.affiliation: Faculty of Medicine, Lomonosov Moscow State University, 31-5, Lomonosovsky av, Moscow, 119191, Russia. rkseniya@mail.ru.
authors.forename: Ksenia
authors.initials: K
authors.lastname: Rubina
authors.affiliation: Department of Molecular Biology and Genetics, SRI of Physical-Chemical Medicine, 1a, Malaya Pirogovskaya, Moscow, 119435, Russia. lazar0@mail.ru.
authors.forename: Vassiliy
authors.initials: V
authors.lastname: Lazarev
authors.affiliation: Department of Molecular Biology and Genetics, SRI of Physical-Chemical Medicine, 1a, Malaya Pirogovskaya, Moscow, 119435, Russia. vgovorun@yandex.ru.
authors.forename: Vadim
authors.initials: V
authors.lastname: Govorun
mesh_terms: D000273:Adipose Tissue / Q000166:cytology*; D000328:Adult; D002454:Cell Differentiation; D015687:Cell Hypoxia; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D059630:Mesenchymal Stem Cells / Q000145:classification* / Q000378:metabolism; D008875:Middle Aged; D011506:Proteins / Q000378:metabolism; D022142:Secretory Vesicles / Q000378:metabolism*
chemical_list: D017077:Culture Media, Conditioned; D011506:Proteins