Hypoxia represses FOXF1 in lung endothelial cells through HIF-1α.

Introduction: Forkhead Box F1 (FOXF1) transcription factor plays a critical role in lung angiogenesis during embryonic development and lung repair after injury. FOXF1 expression is decreased in endothelial cells after lung injury; however, molecular mechanisms responsible for the FOXF1 transcript changes in injured lung endothelium remain unknown. Methods: We used immunostaining of injured mouse lung tissues, FACS-sorted lung endothelial cells from hypoxia-treated mice, and data from patients diagnosed with hypoxemic respiratory failure to demonstrate that hypoxia is associated with decreased FOXF1 expression. Endothelial cell cultures were used to induce hypoxia in vitro and identify the upstream molecular mechanism through which hypoxia inhibits FOXF1 gene expression. Results: Bleomycin-induced lung injury induced hypoxia in the mouse lung tissue which was associated with decreased Foxf1 expression. Human FOXF1 mRNA was decreased in the lungs of patients diagnosed with hypoxemic respiratory failure. Mice exposed to hypoxia exhibited reduced Foxf1 expression in the lung tissue and FACS-sorted lung endothelial cells. In vitro, hypoxia (1% of O2) or treatment with cobalt (II) chloride increased HIF-1α protein levels but inhibited FOXF1 expression in three endothelial cell lines. Overexpression of HIF-1α in cultured endothelial cells was sufficient to inhibit Foxf1 expression. siRNA-mediated depletion of HIF-1α prevented the downregulation of Foxf1 gene expression after hypoxia or cobalt (II) chloride treatment. Conclusion: Hypoxia inhibits FOXF1 expression in endothelial cells in a HIF-1α dependent manner. Our data suggest that endothelial cell-specific inhibition of HIF-1α via gene therapy can be considered to restore FOXF1 and improve lung repair in patients with severe lung injury.

Effects of a Remotely Delivered Cognitive Behavioral Coaching Program on the Self-Rated Functional Disability of Participants with Low Back Pain.

PURPOSE: A remotely delivered cognitive behavioral coaching (CBC) program was offered as a service benefit for commercial health plan members with low back pain (LBP). This study describes changes in self-rated functional disability in a sample of plan members participating in the program (N=423). METHODS: Independent measures included demographics, length of program enrollment, total CBC sessions, and baseline self-reported patient activation and presenteeism levels. Participants rated their functional disability level due to LBP using the Oswestry Disability Index (ODI). Dependent outcomes quantified change in participant functional disability rating (final ODI score minus baseline ODI score). Nonparametric tests compare differences between groups and within-group ODI score change. Two generalized linear models test for associations between independent variables and the ODI change score. RESULTS: A significant difference between baseline and final ODI scores was observed at the overall program level (p<.001) and within all independent variable categories of interest. Over 68% of total participants (n=289) reported improved functional ability from baseline to final (decrease in ODI score). Participants who completed more CBC sessions demonstrated significantly greater improvement in functional ability (p=.038) compared to those who completed fewer sessions. Participants aged 55 and older were significantly more likely to show deterioration in functional ability from baseline to final (p=.021). CONCLUSION: Outcomes suggest that program participation can influence self-rated functional disability in the management of LBP.

FT-4202, an oral PKR activator, has potent antisickling effects and improves RBC survival and Hb levels in SCA mice.

Sickle cell anemia (SCA) results from an abnormal sickle hemoglobin (HbS). HbS polymerizes upon deoxygenation, resulting in red blood cell (RBC) sickling and membrane damage that cause vaso-occlusions and hemolysis. Sickle RBCs contain less adenosine triphosphate and more 2,3-diphosphoglycerate than normal RBCs, which allosterically reduces hemoglobin (Hb) oxygen (O2) affinity (ie, increases the partial pressure of oxygen at which hemoglobin is 50% saturated with oxygen [P50]), potentiating HbS polymerization. Herein, we tested the effect of investigational agent FT-4202, an RBC pyruvate kinase (PKR) activator, on RBC sickling and membrane damage by administering it to Berkeley SCA mice. Two-week oral FT-4202 administration was well tolerated, decreasing HbS P50 to levels similar to HbA and demonstrating beneficial biological effects. In FT-4202-treated animals, there was reduced sickling in vivo, demonstrated by fewer irreversibly sickled cells, and improved RBC deformability, assessed at varying shear stress. Controlled deoxygenation followed by reoxygenation of RBCs obtained from the blood of FT-4202-treated mice showed a shift in the point of sickling to a lower partial pressure of oxygen (pO2). This led to a nearly 30% increase in RBC survival and a 1.7g/dL increase in Hb level in the FT-4202-treated SCA mice. Overall, our results in SCA mice suggest that FT-4202 might be a potentially useful oral antisickling agent that warrants investigation in patients with SCA.

Dual targeting of MEK and PI3K pathways attenuates established and progressive pulmonary fibrosis.

Pulmonary fibrosis is often triggered by an epithelial injury resulting in the formation of fibrotic lesions in the lung, which progress to impair gas exchange and ultimately cause death. Recent clinical trials using drugs that target either inflammation or a specific molecule have failed, suggesting that multiple pathways and cellular processes need to be attenuated for effective reversal of established and progressive fibrosis. Although activation of MAPK and PI3K pathways have been detected in human fibrotic lung samples, the therapeutic benefits of in vivo modulation of the MAPK and PI3K pathways in combination are unknown. Overexpression of TGFα in the lung epithelium of transgenic mice results in the formation of fibrotic lesions similar to those found in human pulmonary fibrosis, and previous work from our group shows that inhibitors of either the MAPK or PI3K pathway can alter the progression of fibrosis. In this study, we sought to determine whether simultaneous inhibition of the MAPK and PI3K signaling pathways is a more effective therapeutic strategy for established and progressive pulmonary fibrosis. Our results showed that inhibiting both pathways had additive effects compared to inhibiting either pathway alone in reducing fibrotic burden, including reducing lung weight, pleural thickness, and total collagen in the lungs of TGFα mice. This study demonstrates that inhibiting MEK and PI3K in combination abolishes proliferative changes associated with fibrosis and myfibroblast accumulation and thus may serve as a therapeutic option in the treatment of human fibrotic lung disease where these pathways play a role.