Fig 2: Hematoxylin and eosin staining of rat hypoxia-exposed lung tissues. Neonatal rats were exposed to (A) normoxic or (B) hyperoxic conditions for 14 days; hyperoxia exposed rats were subsequently injected with (C) shRNA-NC or (D) shRNA-PLGF. Magnification, ×100; scale bar, 100 µm. NC, negative control; PLGF, placental growth factor; shRNA, short hairpin RNA.

Fig 3: Expression of VEGF, PlGF, VEGFR1 (Flt1), and VEGFR2 (Flk1) mRNA by real‐time PCR in term placenta (2:1 ratio of tissue from the central and peripheral regions of the placenta, respectively) from physically active (n = 23) and inactive (n = 22) women. Relative quantification of mRNA VEGF (a), PlGF (b), VEGFR1 (Flt1) (c) and VEGFR2 (Flk1) (d) expression. Relative expression was normalized to the expression of GAPDH in all samples. All data are represented as mean ± SD. *p < 0.05.

Fig 4: Expression of ZEB2 in hyperoxia-exposed lung tissue. Neonatal rats were exposed to normoxic or hyperoxic conditions for 14 days; hyperoxia exposed rats were subsequently injected with shRNA-NC or shRNA-PLGF. (A) Western blot analysis and (B) quantification was performed to determine ZEB2 protein expression levels in rat lung tissues; β-actin was used as the endogenous control. Data are presented as the mean ± standard deviation. n=8. **P<0.01. (C) ZEB2 mRNA expression levels were detected by reverse transcription-quantitative PCR. Data are presented as the mean ± standard deviation. n=3. **P<0.01. NC, negative control; PLGF, placental growth factor; shRNA, short hairpin RNA; ZEB, zinc-finger E-box binding homeobox 2.

Fig 5: Expression of PLGF in hyperoxia-exposed lung tissue. Neonatal rats were exposed to normoxic or hyperoxic conditions for 14 days; hyperoxia exposed rats were subsequently injected with shRNA-NC or shRNA-PLGF. (A) Western blot analysis and (B) quantification was performed to determine PLGF protein expression levels in rat lung tissues; β-actin was used as the endogenous control. Data are presented as the mean ± standard deviation. n=8. **P<0.01. (C) Immunostaining of rat lung tissues for PLGF expression; hematoxylin was used as a counterstain. Magnification, ×100; scale bar, 100 µm. (D) PLGF mRNA expression levels were detected by reverse transcription-quantitative PCR. Data are presented as the mean ± standard deviation. n=3. **P<0.01. NC, negative control; PLGF, placental growth factor; shRNA, short hairpin RNA.