ALDOB K87 Lactylation Regulates Mitochondrial Dynamics in Pulmonary Hypertension

Study Background and Research Question

Pulmonary hypertension (PH) is a progressive cardiopulmonary disorder characterized by remodeling of the pulmonary vasculature, leading to increased pulmonary arterial pressure and right ventricular failure. Despite advances in vasodilator therapy, the 5-year survival rate for PH remains below 65%, underscoring the need for new therapeutic targets (source: Yi et al., 2026). A growing body of evidence implicates abnormal proliferation and migration of pulmonary artery smooth muscle cells (PASMCs) as central to pathologic vascular remodeling. However, the molecular mechanisms that link metabolic changes to these cellular behaviors remain incompletely understood. Recent studies highlight the importance of metabolic reprogramming in PASMCs, specifically a shift towards aerobic glycolysis (the Warburg effect), which increases lactate production. Importantly, lactate is not merely a metabolic byproduct; it also serves as a substrate for protein post-translational modification via lactylation. While the regulatory role of lactylation in histone modification and tumor biology has been explored, its relevance to nonhistone proteins and vascular remodeling in PH had not been fully elucidated prior to this study (source: Yi et al., 2026).

Key Innovation from the Reference Study

Yi et al. (2026) introduce a novel mechanistic link between metabolic flux and cellular phenotype in PH by identifying that lactylation of aldolase B (ALDOB) at lysine 87 (K87) is a key regulator of mitochondrial fission and metabolic reprogramming. Their comprehensive lactylomic profiling in hypoxic PASMCs revealed significantly elevated nonhistone K87 lactylation on ALDOB, a glycolytic enzyme previously not associated with mitochondrial dynamics in PH. The study further demonstrates that this specific lactylation event bridges glycolytic activity with the recruitment of dynamin-related protein 1 (DRP1) to mitochondria, thereby inducing mitochondrial fragmentation and promoting the proliferative and migratory phenotype typical of PH PASMCs. This lactate–ALDOB–DRP1 signaling axis represents a significant advance in our understanding of how metabolism-driven post-translational modifications orchestrate disease-relevant cellular remodeling (source: Yi et al., 2026).

Methods and Experimental Design Insights

The authors employed an integrated lactylomic approach that combined mass spectrometry-based proteomics with in vitro and in vivo models of PH. The workflow began with hypoxic stimulation of human PASMCs, followed by global mapping of lactylated proteins. ALDOB-K87 emerged as a prominent lactylation site under hypoxic conditions. To assess functional consequences, the team generated ALDOB mutants mimicking constitutive lactylation (K87Q) and de-lactylation (K87R). These constructs were expressed in PASMCs, and the impact on mitochondrial morphology was quantified using confocal microscopy and mitochondrial fragmentation assays. In complementary rodent PH models, pharmacological and genetic interventions targeting ALDOB lactylation were evaluated for effects on pulmonary vascular remodeling and right ventricular hypertrophy. Mechanistic investigations elucidated the regulatory relationship between ALDOB lactylation and DRP1 SUMOylation status. The authors demonstrated that K87 lactylation promotes sentrin/SUMO-specific peptidase 3 (SENP3)-mediated deSUMOylation of DRP1, facilitating its mitochondrial translocation and subsequent fission events. Sirtuin 1 (SIRT1) was identified as a delactylase for ALDOB, with its downregulation in PH contributing to persistent lactylation-driven pathology.

Protocol Parameters

• cell proliferation assay | PASMCs exposed to 1% O₂, 24-48 h | applicable for hypoxic stress modeling in vascular cells | Recapitulates PH-associated metabolic changes in vitro | paper
• lactylome profiling | 50-100 μg protein input, anti-lactyl-lysine enrichment | suitable for identifying lactylated proteins in cell/tissue extracts | Enables unbiased detection of global and site-specific lactylation events | paper
• mitochondrial fission analysis | MitoTracker staining, confocal microscopy, quantification of fragmentation index | optimal for assessing mitochondrial dynamics in PASMCs | Provides quantitative readout of fission/fusion balance | paper
• murine recombinant PDGF-BB stimulation | 1–10 ng/ml, 24–72 h | recommended for inducing PASMC proliferation in metabolic studies | Supports robust cell proliferation and enables metabolic-phenotypic coupling | workflow_recommendation

Core Findings and Why They Matter

The central discovery is that hypoxia-induced ALDOB-K87 lactylation amplifies glycolytic flux and establishes a feed-forward loop that sustains lactylation. This, in turn, recruits deSUMOylated DRP1 to mitochondria, promoting mitochondrial fragmentation—a hallmark of the hyperproliferative PASMC phenotype in PH. The authors show that genetic or pharmacological inhibition of ALDOB lactylation reduces mitochondrial fission and attenuates PH pathology in vivo, suggesting that this pathway is not only mechanistically relevant but also therapeutically actionable (source: Yi et al., 2026). Another significant advance is the identification of SIRT1 as an ALDOB delactylase. Downregulation of SIRT1 in PH sustains aberrant lactylation, further linking metabolic, epigenetic, and mitochondrial regulatory axes. Together, these insights clarify how metabolic reprogramming, post-translational modification, and mitochondrial dynamics converge to drive vascular remodeling in PH.

Comparison with Existing Internal Articles

Several internal resources provide practical guidance for researchers modeling PASMC proliferation and metabolic remodeling:

• Optimizing Cell Proliferation Assays with Murine Recombinant PDGF-BB: This guide details advanced workflows using murine recombinant PDGF-BB to stimulate smooth muscle cell proliferation, aligning with the reference study's emphasis on robust PASMC models for metabolic and mitogenic interrogation.
• Applied Workflows with Murine Recombinant PDGF-BB in Vascular Research: This article highlights how PDGF-BB enables precise modulation of cell proliferation and metabolic remodeling, further bridging the gap between metabolic signaling studies and assay development for vascular remodeling research.
• ALDOB K87 Lactylation Orchestrates Mitochondrial Fission in PH: This summary reinforces the mechanistic connection between lactate metabolism, ALDOB modification, and mitochondrial dynamics, echoing the current reference's core findings.

These internal resources complement the reference study by providing actionable assay parameters and troubleshooting insights for researchers aiming to dissect metabolic and mitogenic pathways in pulmonary vascular cells. Notably, use of murine recombinant PDGF-BB is highlighted as a practical tool for reliable and reproducible induction of PASMC proliferation, a critical prerequisite for mechanistic studies of metabolic reprogramming.

Limitations and Transferability

While the study offers compelling mechanistic insights, several limitations must be acknowledged. First, the lactylomic profiling and functional analyses were primarily conducted in hypoxic PASMCs and rodent models. Although these systems recapitulate key aspects of human PH, interspecies differences and the complexity of human pulmonary vascular disease may limit direct translatability. Furthermore, the specific contribution of ALDOB K87 lactylation to other cell types and vascular beds remains to be determined. The study's reliance on overexpression and knock-in mutant approaches, while informative, necessitates cautious interpretation regarding physiological relevance. Finally, potential off-target effects of pharmacological inhibitors and the broader impact of manipulating global lactylation on cellular homeostasis warrant further investigation (source: Yi et al., 2026).

Research Support Resources

For researchers aiming to model PASMC proliferation and metabolic reprogramming in vitro, validated mitogenic stimuli are essential for generating reproducible and interpretable results. PDGF-BB, murine recombinant protein (SKU P1048) from APExBIO is a research-grade growth factor with confirmed mitogen activity in murine BALB/c 3T3 cells at sub-nanogram concentrations (ED50 < 2 ng/ml; source: product_spec). It can be incorporated into cell proliferation assays to support the type of workflows described in the reference and internal articles. The product’s purity, low endotoxin content, and compatibility with a range of aqueous buffers make it suitable for studies investigating smooth muscle cell proliferation, metabolic remodeling, and PDGFR-mediated signaling. For protocol optimization and troubleshooting, see workflow recommendations in the internal articles cited above.