Abstract 12932: An Epigenetic Upregulation of Dynamin 2, a Regulator of Mitochondrial Fission, Promotes Human and Experimental Pulmonary Arterial Hypertension
Bibliographic record
Abstract
Introduction: Increase in mitotic fission in pulmonary arterial smooth muscle cells (PASMC) contributes to the obstructive vasculopathy in pulmonary arterial hypertension (PAH). PAH’s fissogenic phenotype is due, in part, to excessive mitochondrial fission caused by activation of dynamin related protein-1 (Drp1). Recent observation suggests that to complete mitochondrial fission, Drp1 requires assistance from the GTPase dynamin 2 (DNM2). In this study we explore the role of DNM2 in the pathogenesis of PAH. Hypothesis: In PAH, increased expression of DNM2 increases mitochondrial fission and proliferation of PASMC. Methods: Immunoblot was used to quantify the expression of DNM2 in control (n=4) and PAH PASMC (n=5). Immunofluorescence was used to quantify the expression of DNM2 in the pulmonary arteries of monocrotaline (MCT) vs control rats. Flow cytometry was used to assess the effects of manipulating the expression of DNM2 on cell proliferation, cell cycle progression and rates of unstimulated apoptosis. Mitochondrial network structure was assessed using confocal imaging of cells infected with Adv-TOM20 mNeon green. Results: The expression of DNM2 was increased in human PAH PASMC vs control PASMC. Increase in the expression of DNM2 expression was also observed in the pulmonary arteries of MCT-PAH rats. Silencing DNM2 inhibited mitochondrial fission in PAH PASMC. Furthermore, silencing DNM2 inhibited proliferation in PAH PASMC by blocking the cell cycle at G1/G0. Conversely, augmenting DNM2 in normal PASMC induced mitochondrial fission and accelerated cell proliferation, recapitulating the PAH phenotype. In silico analysis identified miR-124-3p as a putative negative regulator of DNM2. Augmenting miR-124-3p decreased DNM2 expression, inhibited proliferation and induced apoptosis in PAH PASMC. Conclusion: DNM2 promotes mitochondrial fission and regulates cell proliferation in human PAH PASMC. Decreased miR-124-3p expression may contribute to upregulation of DNM2 in PAH. This work highlights the importance of DNM2 as partner with Drp1 in regulation of mitochondrial fission and shows that like Drp1, DNM2 is increased in human PAH. DNM2 may constitute new therapeutic target for PAH.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.005 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".