Review: Heme oxygenase-1 in healthy and pathological aging
This review evaluates how heme oxygenase-1 (HO-1) expression changes with age across major organs and how HO-1 and its metabolites relate to age-related diseases, especially dementia and cardiovascular disorders. Effects appear to depend on expression level, timing, tissue and downstream balance. [1]
Automatic summary · not editorially reviewed
The key findings
HO-1 is described as a stress-inducible enzyme that degrades heme into carbon monoxide, biliverdin and iron, with biliverdin then reduced to bilirubin. [1]
The review examines age-associated HO-1 expression changes across major organs and HO-1 roles in age-related diseases, especially dementia and cardiovascular disorders. [1]
HO-1 effects appear to depend on expression level, temporal regulation, tissue specificity and the balance between protective and deleterious downstream pathways. [1]
The source at a glance
- Study type / format
- Review (abstract only)
- Population / context
- Not specified in the abstract; the review concerns HO-1 across major organs and age-related diseases.
- Summary based on
- Study abstract
- Original publication
- September 20, 2026
HO-1 enzyme and hallmarks of aging
The review describes HO-1 as a stress-inducible enzyme that breaks down heme into carbon monoxide, biliverdin and iron; biliverdin is then converted to bilirubin by biliverdin reductase. The authors present HO-1 as a key regulator of several hallmarks of aging, naming oxidative stress, inflammation, autophagy, mitochondrial dysfunction and cellular senescence.
Supporting source [1]
Age-related diseases: dementia and cardiovascular focus
The review examines age-associated changes in HO-1 expression across major organs and the roles of HO-1 and its metabolites in age-related diseases, with particular emphasis on dementia and cardiovascular disorders. It also notes that growing life expectancy has increased the prevalence of age-related disorders such as dementia, cardiovascular disease, frailty, osteoporosis, sarcopenia and cancer.
Supporting source [1]
Balance, tissue context and open research questions
Current evidence suggests HO-1 effects depend not only on expression level but also on temporal regulation, tissue specificity and the balance between protective and harmful downstream pathways. The authors call for future research to define physiological and therapeutic ranges of HO-1 activity in different tissues, sexes and stages of aging, and to clarify the separate contributions of carbon monoxide, bilirubin and iron metabolism. They suggest such work may support precision-medicine approaches, but no such approach is presented as established.
Supporting source [1]
How to interpret this
This is an abstract of a review; the full text was not reviewed. The abstract reports no study design, sample, follow-up or effect sizes, and it presents proposed future research directions rather than validated interventions.
Based on the study abstract; the full paper, tables and supplementary data were not reviewed.
Source & supporting passages
Wahba S, Stec DE. · europepmc.org · September 20, 2026