Nanoparticle Delivery of STAT3 Alleviates Pulmonary Hypertension in a Mouse Model of Alveolar Capillary Dysplasia

BACKGROUND

Pulmonary hypertension (PH) is a common complication in patients with alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV), a severe congenital disorder associated with mutations in the FOXF1 gene. Although the loss of alveolar microvasculature causes PH in patients with ACDMPV, it is unknown whether increasing neonatal lung angiogenesis could prevent PH and right ventricular (RV) hypertrophy.

METHODS

We used echocardiography, RV catheterization, immunostaining, and biochemical methods to examine lung and heart remodeling and RV output in Foxf1^WT/S52F mice carrying the S52F Foxf1 mutation (identified in patients with ACDMPV). The ability of Foxf1^WT/S52F mutant embryonic stem cells to differentiate into respiratory cell lineages in vivo was examined using blastocyst complementation. Intravascular delivery of nanoparticles with a nonintegrating Stat3 expression vector was used to improve neonatal pulmonary angiogenesis in Foxf1^WT/S52F mice and determine its effects on PH and RV hypertrophy.

RESULTS

Foxf1^WT/S52F mice developed PH and RV hypertrophy after birth. The severity of PH in Foxf1^WT/S52F mice directly correlated with mortality, low body weight, pulmonary artery muscularization, and increased collagen deposition in the lung tissue. Increased fibrotic remodeling was found in human ACDMPV lungs. Mouse embryonic stem cells carrying the S52F Foxf1 mutation were used to produce chimeras through blastocyst complementation and to demonstrate that Foxf1^WT/S52F embryonic stem cells have a propensity to differentiate into pulmonary myofibroblasts. Intravascular delivery of nanoparticles carrying Stat3 cDNA protected Foxf1^WT/S52F mice from RV hypertrophy and PH, improved survival, and decreased fibrotic lung remodeling.

CONCLUSIONS

Nanoparticle therapies increasing neonatal pulmonary angiogenesis may be considered to prevent PH in ACDMPV.

Correlations of expressions of IMP3 and VEGF with stage of osteosarcoma, microvascular density and pulmonary metastasis

PURPOSE

To detect protein expressions of insulin-like growth factor II messenger ribonucleic acid-binding protein 3 (IMP3) and vascular endothelial growth factor (VEGF) in osteosarcoma tissues and explore the relationships of protein expressions of IMP3 and VEGF with stage, microvessel density (MVD) and pulmonary metastasis of osteosarcoma patients.

METHODS

Immunohistochemical staining was used to detect protein expressions of IMP3 and VEGF in 37 cases of osteosarcoma, and their correlations with stage, MVD and pulmonary metastasis of osteosarcoma patients were analyzed in combination with clinical data.

RESULTS

Protein expressions of IMP3 and VEGF in osteosarcoma were significantly higher than those in normal tissues adjacent to the tumor (p<0.05, p<0.05). The distribution of stage III in osteosarcoma patients with high protein expressions of IMP3 and VEGF increased. With the enhancement of protein expressions of IMP3 and VEGF, MVD elevated, the probability of pulmonary metastasis increased, and the survival time decreased markedly in osteosarcoma patients.

CONCLUSIONS

High expressions of IMP3 and VEGF are positively correlated with stage, MVD and pulmonary metastasis of osteosarcoma, and can be applied as potential indicators of the malignant degree of osteosarcoma and the prognosis of patients.