title: Pro-nerve growth factor in the ovary and human granulosa cells.
abstract: BACKGROUND
  Pro-nerve growth factor must be cleaved to generate mature NGF, which was suggested to be a factor involved in ovarian physiology and pathology. Extracellular proNGF can induce cell death in many tissues. Whether extracellular proNGF exists in the ovary and may play a role in the death of follicular cells or atresia was unknown.
  
  
  METHODS
  Immunohistochemistry of human and rhesus monkey ovarian sections was performed. IVF-derived follicular fluid and human granulosa cells were studied by RT-PCR, qPCR, Western blotting, ATP- and caspase-assays.
  
  
  CONCLUSIONS
  Immunohistochemistry of ovarian sections identified proNGF in granulosa cells and Western blotting of human isolated granulosa cells confirmed the presence of proNGF. Ovarian granulosa cells thus produce proNGF. Recombinant human proNGF even at high concentrations did not affect the levels of ATP or the activity of caspase 3/7, indicating that in granulosa cells proNGF does not induce death. In contrast, mature NGF, which was detected previously in follicular fluid, may be a trophic molecule for granulosa cells with unexpected functions. We found that in contrast to proNGF, NGF increased the levels of the transcription factor early growth response 1 and of the enzyme choline acetyl-transferase. A mechanism for the generation of mature NGF from proNGF in the follicular fluid may be extracellular enzymatic cleavage. The enzyme MMP7 is known to cleave proNGF and was identified in follicular fluid and as a product of granulosa cells. Thus the generation of NGF in the ovarian follicle may depend on MMP7.
authors.forename: Sabine
authors.initials: S
authors.lastname: Meinel
authors.forename: Jan
authors.initials: J
authors.lastname: Blohberger
authors.forename: Dieter
authors.initials: D
authors.lastname: Berg
authors.forename: Ulrike
authors.initials: U
authors.lastname: Berg
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Dissen
authors.forename: Sergio R
authors.initials: SR
authors.lastname: Ojeda
authors.forename: Artur
authors.initials: A
authors.lastname: Mayerhofer
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D017209:Apoptosis; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D053179:Caspase 7 / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D005260:Female; D015571:Follicular Fluid / Q000201:enzymology / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D006107:Granulosa Cells / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008253:Macaca mulatta; D020783:Matrix Metalloproteinase 7 / Q000378:metabolism*; D020932:Nerve Growth Factor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006080:Ovarian Follicle / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011498:Protein Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism
chemical_list: C502240:NGF protein, human; D010446:Peptide Fragments; D011498:Protein Precursors; D011994:Recombinant Proteins; C061397:pro-nerve growth factor, human; D000255:Adenosine Triphosphate; D020932:Nerve Growth Factor; C505407:CASP3 protein, human; C505520:CASP7 protein, human; D053148:Caspase 3; D053179:Caspase 7; C060932:MMP7 protein, human; D020783:Matrix Metalloproteinase 7