Smad7 Is Highly Expressed in Human Degenerative Discs and Participates in IL-1β-Induced Apoptosis of Rat AF Cells via the Mitochondria Pathway

Figure 4

Overexpression of Smad7 exaggerates the IL-1β-induced apoptosis (a) qRT-PCR assays to detect the mRNA expression of Smad7 in AF cells treated with Con, Ad-Con and Ad-Smad7. (b) Western blotting assays to detect the protein expression of Smad7 in AF cells treated with Con, Ad-Con, and Ad-Smad7. (c) Representative flow cytometry graphs of rat AF cells stained with Annexin V-FITC and PI. Gates were set as follows: Q1 (Annexin V^-PI⁺), necrosis cells; Q2 (Annexin V⁺PI⁺), late-stage apoptotic cells; Q3 (Annexin V^-PI^-), live cells; Q4 (Annexin V⁺PI^-), early-stage apoptotic cells. Apoptotic rates of three groups of rat AF cells at different time points. The percentages of Annexin V⁺ cells were calculated at Con, Ad-Con, and Ad-Smad7 at 12, 24, and 48 h, respectively. (d) Rat AF cells stained by Hoechst 33285 at 12, 24, and 48 h. Original magnification: ×200. values less than 0.05 were considered statistically significant. . All experiments were performed at least three times. Con: control rat AF cells; Ad-Con: rat AF cells infected by adenovirus taking empty plasmid; Ad-Smad7: rat AF cells infected by adenovirus taking Smad7 overexpression plasmid. Original magnification: ×100. Scale bar: 10 μM.

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