title: The matrix metalloproteinase inhibitor marimastat promotes neural progenitor cell differentiation into neurons by gelatinase-independent TIMP-2-dependent mechanisms.
abstract: Metalloproteinases (MMPs) and their endogenous inhibitors (TIMPs), produced in the brain by cells of non-neural and neural origin, including neural progenitors (NPs), are emerging as regulators of nervous system development and adult brain functions. In the present study, we explored whether MMP-2, MMP-9, and TIMP-2, abundantly produced in the brain, modulate NP developmental properties. We found that treatment of NPs, isolated from the murine fetal cerebral cortex or adult subventricular zone, with the clinically tested broad-spectrum MMP inhibitor Marimastat profoundly affected the NP differentiation fate. Marimastat treatment allowed for an enrichment of our cultures in neuronal cells, inducing NPs to generate higher percentage of neurons and a lower percentage of astrocytes, possibly affecting NP commitment. Consistently with its proneurogenic effect, Marimastat early downregulated the expression of Notch target genes, such as Hes1 and Hes5. MMP-2 and MMP-9 profiling on proliferating and differentiating NPs revealed that MMP-9 was not expressed under these conditions, whereas MMP-2 increased in the medium as pro-MMP-2 (72 kDa) during differentiation; its active form (62 kDa) was not detectable by gel zymography. MMP-2 silencing or administration of recombinant active MMP-2 demonstrated that MMP-2 does not affect NP neuronal differentiation, nor it is involved in the Marimastat proneurogenic effect. We also found that TIMP-2 is expressed in NPs and increases during late differentiation, mainly as a consequence of astrocyte generation. Endogenous TIMP-2 did not modulate NP neurogenic potential; however, the proneurogenic action of Marimastat was mediated by TIMP-2, as demonstrated by silencing experiments. In conclusion, our data exclude a major involvement of MMP-2 and MMP-9 in the regulation of basal NP differentiation, but highlight the ability of TIMP-2 to act as key effector of the proneurogenic response to an inducing stimulus such as Marimastat.
authors.affiliation: Department of Biology and Biotechnology Charles Darwin, Sapienza, University of Rome, Rome, Italy.
authors.forename: Maddalena
authors.initials: M
authors.lastname: Sinno
authors.forename: Stefano
authors.initials: S
authors.lastname: Biagioni
authors.forename: Maria Antonietta
authors.initials: MA
authors.lastname: Ajmone-Cat
authors.forename: Irene
authors.initials: I
authors.lastname: Pafumi
authors.forename: Pasquale
authors.initials: P
authors.lastname: Caramanica
authors.forename: Virginia
authors.initials: V
authors.lastname: Medda
authors.forename: Gaetana
authors.initials: G
authors.lastname: Tonti
authors.forename: Luisa
authors.initials: L
authors.lastname: Minghetti
authors.forename: Ferdinando
authors.initials: F
authors.lastname: Mannello
authors.forename: Emanuele
authors.initials: E
authors.lastname: Cacci
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D015870:Gene Expression; D055785:Gene Knockdown Techniques; D006877:Hydroxamic Acids / Q000494:pharmacology*; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors / Q000494:pharmacology*; D051379:Mice; D058953:Neural Stem Cells / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000201:enzymology; D034741:RNA, Small Interfering / Q000235:genetics; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000235:genetics / Q000378:metabolism*
chemical_list: D006877:Hydroxamic Acids; D061965:Matrix Metalloproteinase Inhibitors; D034741:RNA, Small Interfering; D019716:Tissue Inhibitor of Metalloproteinase-2; C100342:marimastat; D020778:Matrix Metalloproteinase 2; C522362:Mmp2 protein, mouse; D020780:Matrix Metalloproteinase 9; C501830:Mmp9 protein, mouse