Open AccessImpact of mechanical stimulation on the chondrogenic processes in human bone marrow aspirates modified to overexpress sox9 via rAAV vectors
Author(s) -
Venkatesan Jagadeesh K.,
Frisch Janina,
ReyRico Ana,
Schmitt Gertrud,
Madry Henning,
Cucchiarini Magali
Publication year - 2017
Publication title -
journal of experimental orthopaedics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 18
ISSN - 2197-1153
DOI - 10.1186/s40634-017-0097-1
Subject(s) - chondrogenesis , sox9 , bone marrow , genetic enhancement , stimulation , cartilage , microbiology and biotechnology , chemistry , matrix (chemical analysis) , biomedical engineering , biology , immunology , medicine , anatomy , gene expression , gene , endocrinology , biochemistry , chromatography
Background Evaluation of gene‐based approaches to target human bone marrow aspirates in conditions of mechanical stimulation that aim at reproducing the natural joint environment may allow to develop improved treatments for articular cartilage injuries. In the present study, we investigated the potential of rAAV‐mediated sox9 gene transfer to enhance the chondrogenic differentiation processes in human bone marrow aspirates under established hydrodynamic conditions compared with the more commonly employed static culture conditions. Methods Fresh human bone marrow aspirates were transduced with rAAV‐FLAG‐h sox9 (40 μl) and maintained for up to 28 days in chondrogenic medium under mechanically‐induced conditions in dynamic flow rotating bioreactors that permit tissue growth and matrix deposition relative to static culture conditions. The samples were then processed to examine the potential effects of sox9 overexpression on the cellular activities (matrix synthesis, proliferation) and on the chondrogenic differentiation potency compared with control treatments (absence of rAAV vector; reporter rAAV‐ lacZ , rAAV‐RFP, and rAAV‐ luc gene transfer). Results Prolonged, significant sox9 overexpression via rAAV was achieved in the aspirates for at least 28 days when applying the rAAV‐FLAG‐h sox9 construct, leading to higher, prolonged levels of matrix biosynthesis and to enhanced chondrogenic activities relative to control treatments especially when maintaining the samples under mechanical stimulation. Administration of sox9 however did not impact the indices of proliferation in the aspirates. Remarkably, sox9 gene transfer also durably delayed hypertrophic and osteogenic differentiation in the samples regardless of the conditions of culture applied versus control treatments. Conclusions The current observations show the value of genetically modifying human bone marrow aspirates upon mechanical stimulation by rAAV sox9 as a promising strategy for future treatments to improve cartilage repair by implantation in lesions where the tissue is submitted to natural mechanical forces.