<i>Col1a1(3.6)</i>-Cre-mediated conditional deletion of <i>Pkd1</i> results in enhanced adipogenesis in bone marrow and in bone stromal cell cultures.

<p>(A) Histology of adipocytes in decalcified tibias. Oil Red O staining (upper panel) showed that the numbers of adipocytes and fat droplets in tibia bone marrow were greater in 6-week-old <i>Col1a1(3.6)</i>-Cre; <i>Pkd1</i>^flox/flox mice compared with age-matched control <i>Pkd1</i>^flox/flox mice. Osmium tetroxide (OsO4) staining by μCT analyses (lower panel) showed that adipocyte volume/marrow volume (Ad.V/Ma.V, %) and adipocyte number (Ad.N, mm⁻³) were much higher in the proximal tibia from 6-week-old <i>Col1a1(3.6)</i>-Cre; <i>Pkd1</i>^flox/flox mice compared with age-matched control <i>Pkd1</i>^flox/flox mice. (B) Adipocytic differentiation in BMSC cultures. An increase of adipogenesis potential was observed in 6-week-old <i>Col1a1(3.6)</i>-Cre; <i>Pkd1</i>^flox/flox BMSC cultures, evidenced by a significant increase of Oil Red O staining in adipogenic cultures. (C and D) Expression of adipogenic markers by real-time RT-PCR. Significantly increased levels of <i>PPARγ</i> and <i>aP2</i> mRNAs were observed in 6-week-old <i>Col1a1(3.6)</i>-Cre; <i>Pkd1</i>^flox/flox BMSC cultures compared with control (<i>Pkd1</i>^flox/flox) cultures. Data are expressed as the mean ± SD from three independent experiments. ^# Significant difference from control (<i>Pkd1</i>^flox/flox) at <i>P<</i>0.05.