Reduced Cystathionine Γ-Lyase Levels May Contribute Meaningfully to Age-Related Neurodegeneration

Why It Matters

Because CSE loss directly drives multiple aging‑related brain pathologies, restoring its activity could mitigate neurodegeneration, offering a novel intervention point for age‑linked diseases.

Key Takeaways

• CSE deficiency triggers oxidative stress in mouse brain
• Loss of CSE compromises blood‑brain barrier integrity
• CSE knockout impairs neurogenesis and cognitive performance
• H2S production falls with age, reducing neuroprotection
• Targeting CSE offers new avenue for neurodegenerative therapy

Pulse Analysis

Hydrogen sulfide (H2S) has emerged as a signaling molecule that modulates inflammation, autophagy, and vascular health, especially in the context of aging. While cystathionine β‑synthase (CBS) was long considered the primary enzyme generating H2S in the brain, recent work reveals that cystathionine γ‑lyase (CSE) also contributes substantially to neuronal H2S pools. Age‑related declines in CSE expression reduce endogenous H2S, potentially weakening the brain’s intrinsic defense mechanisms against oxidative stress and protein aggregation, hallmarks of neurodegenerative disease.

In a recent PNAS study, scientists created a global CSE knockout mouse to test whether the enzyme’s loss alone could recapitulate age‑associated brain dysfunction. The CSE‑null mice displayed heightened oxidative damage, compromised blood‑brain barrier integrity, and disrupted neurotrophin signaling, leading to deficits in spatial learning and memory tasks. Proteomic profiling uncovered altered pathways linked to neurogenesis and synaptic maintenance, confirming that CSE supports multiple aspects of neuronal homeostasis. These phenotypes mirror those observed in aged wild‑type rodents, underscoring CSE’s central role.

The findings reposition CSE as a viable drug target for slowing or reversing neurodegeneration. Pharmacological strategies could aim to boost CSE activity, enhance its expression, or deliver H2S donors that mimic its downstream effects, thereby restoring redox balance and supporting blood‑brain barrier function. Moreover, the study prompts a re‑evaluation of therapeutic pipelines that have focused exclusively on CBS, suggesting that combined modulation of both enzymes may yield synergistic benefits. Ongoing research will need to address delivery challenges and validate CSE‑centric interventions in human cohorts.