The clinical case for the framework rests on sobering epidemiology. Among young hemorrhagic stroke survivors assessed nearly a decade after their bleed, depressive symptoms were present in roughly 23 percent and anxiety in 40 percent. A multicenter electronic health-record study found that active screening at one, three, and twelve months identified depressive symptoms in about 22 percent of patients, roughly seven times more often than coded diagnoses alone. Among survivors of large spontaneous hemorrhages in the MISTIE III trial, 36 percent met the depression threshold at six months, and those with depression were far more likely to show worsening disability. Anxiety persists for years in about a fifth of survivors, often overlapping with depressive symptoms, while a pooled analysis of eighteen studies estimated that cognitive impairment affects 46 percent of hemorrhagic stroke patients. These figures, the review argues, establish post-ICH neuropsychiatric dysfunction as a multidimensional syndrome with biological underpinnings that remain largely unexplained.

What makes hemorrhagic stroke biologically distinct, the authors contend, is the hematoma itself. Ruptured vessels flood brain tissue with blood, and as red blood cells lyse they release hemoglobin, hemin, and free iron, which catalyze reactive oxygen species through Fenton chemistry, damage mitochondrial membranes, and drive ferroptosis, an iron-dependent form of cell death. Thrombin, another defining component of the hemorrhagic microenvironment, activates protease-activated receptors on microglia, astrocytes, endothelial cells, and neurons, amplifying inflammation, disrupting the blood-brain barrier, and promoting edema. Damage-associated molecular patterns such as HMGB1 further intensify innate immune activation, while complement signaling and waves of infiltrating neutrophils and monocyte-derived macrophages shape the balance between injury amplification and hematoma resolution. This hemorrhage-specific toxic cocktail, the review stresses, is qualitatively different from the ischemic cascade, and it creates the metabolic conditions in which epigenetic and epitranscriptomic reprogramming could take hold.

Central to the new model is a reinterpretation of lactate. Long dismissed as metabolic waste, lactate is now recognized as a signaling molecule capable of covalently modifying lysine residues on histones—a process called lactylation that reshapes chromatin accessibility and gene expression. After an intracerebral hemorrhage, mass effect, edema, vascular compression, and microvascular dysfunction reduce perihematomal perfusion, pushing oxygen-starved cells toward glycolysis. Human transcriptomic data from the living brain after hemorrhage show staged myeloid activation enriched for hypoxia-inducible factor and glycolytic programs, while mitochondrial injury and failed mitophagy further limit oxidative metabolism. The result is a perihematomal zone awash in lactate, a molecule that can serve as substrate for histone lactylation and thereby convert a temporary metabolic crisis into longer-lasting transcriptional changes in neurons and glia.

The strongest direct evidence in hemorrhagic injury involves two specific histone marks. Histone H3 lysine 14 lactylation, or H3K14la, rises after hemorrhage and in hemin-challenged neurons, where it suppresses the calcium pump PMCA2, aggravates intracellular calcium overload, and promotes neuronal ferroptosis. Histone H3 lysine 18 lactylation, or H3K18la, operates in astrocytes instead: elevated H3K18la is associated with METTL3-dependent m6A modification of lipocalin 2 (LCN2), a secreted inflammatory mediator that drives A1-like reactive astrocyte programs and aggravates brain injury. This H3K18la–METTL3–LCN2 axis is, according to the review, the only demonstrated example of lactylation–m6A crosstalk in hemorrhagic brain injury, linking a metabolic byproduct to an RNA modification and then to glial neurotoxicity through a single, traceable chain of events.

In parallel, the review catalogs a family of m6A-related injury pathways that operate largely independently. The methyltransferase METTL3 regulates transferrin receptor expression to influence ferroptosis, and a METTL3–YTHDF1 axis drives m6A methylation of BCL-3 in brain microvascular endothelial cells. WTAP-mediated modification of UQCRQ promotes mitochondrial reactive oxygen species and inflammation in microglia, m6A-modified miR-873 promotes necroptosis through RIPK3, and the demethylase FTO influences both hemorrhage-induced thalamic pain and ferroptosis-related autophagy. Together these pathways show that the RNA methylation machinery is deeply entangled with the acute cell-death biology of hemorrhagic stroke. What no study has yet shown, the authors emphasize, is that any of these pathways persists long enough, or acts in the right circuits, to cause depression, anxiety, or cognitive decline.

That gap is precisely where the proposed circuit framework enters. Intracerebral hemorrhages most often strike the basal ganglia, thalamus, and subcortical white matter—regions threaded by the fronto-striato-thalamic and limbic networks that govern motivation, reward, emotional regulation, memory, and executive control. Lesion-network studies link post-stroke mood symptoms to structural disconnection and functional diaschisis in exactly these circuits, and damage to thalamo-cortical and fronto-striatal connections impairs reward learning and stress regulation. The review’s proposal is that lactylation-dependent transcriptional reprogramming and m6A-dependent control of inflammatory and cell-death transcripts, acting within reactive glia and vulnerable neurons in these regions, could secondarily compromise synaptic maintenance, long-term potentiation, and network connectivity, opening a molecular route from the acute bleed to chronic psychiatric vulnerability.

The authors are deliberately disciplined about what their framework does and does not claim. No study has shown that manipulating lactylation or m6A machinery after hemorrhage restores synaptic proteins such as PSD95 or Synapsin I, rescues long-term potentiation, normalizes excitatory-inhibitory balance in the amygdala, or improves depression-like behavior independently of reduced acute lesion severity. No human study has jointly measured lactylation, m6A targets, glial biomarkers, and adjudicated psychiatric outcomes. The crosstalk model rests on a single preclinical axis that has not been replicated across laboratories, models, sexes, or ages. Mechanistic studies overwhelmingly terminate during the acute phase, measuring edema, ferroptosis, or neurological deficit scores rather than behavior, sleep, or circuit physiology. By separating demonstrated acute mechanisms from hypothesized downstream psychiatric links, the review aims to prevent overreach while still giving the field a falsifiable target.

That falsifiability comes with a concrete experimental program. The authors call for complementary collagenase and autologous-blood models in both sexes, aged and comorbid animals, and cell-type-specific perturbations of lactylation enzymes and m6A regulators, paired in the same experiments with synaptic structural analysis, electrophysiology, lesion-network mapping, and longitudinal behavioral phenotyping. Human studies should combine serial blood and cerebrospinal fluid biomarkers, neuroimaging, standardized psychiatric assessment, and, where feasible, perihematomal tissue profiling. Mediation and rescue designs should test whether molecular target engagement predicts circuit and behavioral outcomes after accounting for hematoma volume and general neurological improvement. Until such convergent evidence arrives, therapeutic proposals—modulating lactate transporters, LDHA, p300/CBP, METTL3, FTO, or LCN2—remain experimental strategies for mechanism testing, not clinically actionable treatments. Even so, the framework’s near-term value is clear: it defines a testable sequence from hemorrhage-specific metabolic stress to epigenetic and epitranscriptomic injury, and from there to the glial, synaptic, and circuit dysfunction that may underlie some of the most feared long-term consequences of brain hemorrhage.

Subject of Research: Lactylation and m6A RNA modification as candidate mechanisms of neuropsychiatric sequelae after intracerebral hemorrhage

Article Title: Lactylation and N6-Methyladenosine RNA modification in neuropsychiatric sequelae after intracerebral hemorrhage: a hypothesis-generating metabolic–glial–circuit framework

Article References: Chen, W., Teng, H., Yang, X., Gao, F., Han, C., Yang, S., Zhou, H., & Yang, Z. (2026). Lactylation and N6-Methyladenosine RNA modification in neuropsychiatric sequelae after intracerebral hemorrhage: a hypothesis-generating metabolic–glial–circuit framework. Molecular Biology Reports, 53(1), Article 1569. https://doi.org/10.1007/s11033-026-12745-3

Image Credits: AI Generated

DOI: 10.1007/s11033-026-12745-3

Keywords: intracerebral hemorrhage, histone lactylation, N6-methyladenosine, post-stroke depression, astrocyte reactivity, ferroptosis, METTL3, LCN2, neuroinflammation, neural circuits, cognitive impairment, epitranscriptomics