Metabolic and Proliferative State of Vascular Adventitial Fibroblasts in Pulmonary Hypertension Is Regulated Through a MicroRNA-124/PTBP1 (Polypyrimidine Tract Binding Protein 1)/Pyruvate Kinase Muscle Axis

• DOI: 10.1161/circulationaha.117.028069
• Publication Date: 2017-10-03T00:40:22Z
• Authors: Hui Zhang; Daren Wang; Min Li; Lydie Plecitá-Hla...; Angelo D’Alessandro; Jan Tauber; Suzette Riddle; Sushil Kumar; Amanda Flockton; B. Alexandre McKeon; Maria G. Frid; Julie A. Reisz; Paola Caruso; Karim C. El Kasmi; Petr Ježek; Nicholas W. Morrell; Cheng-Jun Hu; Kurt R. Stenmark
• Keywords: PKM2; Polypyrimidine tract-binding protein; Anaerobic glycolysis

Background: An emerging metabolic theory of pulmonary hypertension (PH) suggests that cellular and mitochondrial dysfunction underlies the pathology this disease. We others have previously demonstrated existence hyperproliferative, apoptosis-resistant, proinflammatory adventitial fibroblasts from human bovine hypertensive arterial walls (PH-Fibs) exhibit constitutive reprogramming glycolytic metabolism, accompanied by an increased ratio glucose catabolism through glycolysis versus tricarboxylic acid cycle. However, mechanisms responsible for these alterations in PH-Fibs remain unknown. hypothesized microRNA-124 (miR-124) regulates PTBP1 (polypyrimidine tract binding protein 1) expression to control alternative splicing pyruvate kinase muscle (PKM) isoforms 1 2, resulting PKM2/PKM1 ratio, which promotes proliferation even aerobic environments. Methods: Pulmonary were isolated calves humans with severe PH normal subjects. gene knockdown was achieved via PTBP1-siRNA; restoration miR-124 performed mimic. TEPP-46 shikonin used manipulate PKM2 function. Histone deacetylase inhibitors treat cells. Metabolic products determined mass spectrometry–based metabolomics analyses, function analyzed confocal microscopy spectrofluorometry. Results: detected compared inhibition reversed status PH-Fibs, decreased their cell proliferation, attenuated macrophage interleukin-1β expression. Furthermore, normalizing overexpression or phenotype (decreased production intermediates byproducts, ie, lactate), rescued reprogramming, proliferation. Pharmacological manipulation activity treatment histone produced similar results. Conclusions: In PH, miR-124, factor PTBP1, overall metabolic, proliferative, inflammatory state This can be interventions at various levels cascade. These findings suggest a more integrated view vascular may open unique therapeutic prospects targeting dynamic interactions between mesenchymal cells PH.