HMOX1 — Heme Oxygenase 1

HMOX1 — Heme Oxygenase 1

Introduction

Pathway Diagram

```mermaid
flowchart TD
NFE2L2["NFE2L2<br/>(NRF2 gene)"] -->|"activates"| HMOX1["HMOX1<br/>(Heme Oxygenase-1)"]
NRF2_protein["NRF2<br/>(protein)"] -->|"regulates"| HMOX1
HIF1["HIF1<br/>(pathway)"] -->|"activates"| HMOX1
L_reuteri["L.

HMOX1 — Heme Oxygenase 1

Introduction

Pathway Diagram

Hmox1 — Heme Oxygenase 1 is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

<div class="infobox infobox-gene">
<table>
<tr><th colspan="2" style="background:#f0f0f0; text-align:center;">Gene Information</th></tr>
<tr><td><strong>Symbol</strong></td><td>HMOX1</td></tr>
<tr><td><strong>Full Name</strong></td><td>Heme Oxygenase 1</td></tr>
<tr><td><strong>Chromosome</strong></td><td>22</td></tr>
<tr><td><strong>NCBI Gene ID</strong></td><td><a href="https://www.ncbi.nlm.nih.gov/gene/3162" target="_blank">3162</a></td></tr>
<tr><td><strong>OMIM</strong></td><td><a href="https://www.omim.org/entry/141250" target="_blank">141250</a></td></tr>
<tr><td><strong>UniProt ID</strong></td><td><a href="https://www.uniprot.org/uniprot/P09601" target="_blank">P09601</a></td></tr>
<tr><td><strong>Ensembl ID</strong></td><td><a href="https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000101129" target="_blank">ENSG00000101129</a></td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/aging" style="color:#ef9a9a">Aging</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/atherosclerosis" style="color:#ef9a9a">Atherosclerosis</a>, <a href="/wiki/cancer" style="color:#ef9a9a">Cancer</a>, <a href="/wiki/carcinoma" style="color:#ef9a9a">Carcinoma</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">326 edges</a></td>
</tr>
</table>
</div>

Overview

HMOX1 (Heme Oxygenase 1) is an inducible enzyme that catalyzes the degradation of heme into biliverdin, iron, and carbon monoxide (CO). It is a major cytoprotective enzyme induced by oxidative stress, inflammation, and heme. HMOX1 has been implicated in neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, and ALS, where it plays both protective and potentially harmful roles.

Normal Function

HMOX1 degrades heme to produce biliverdin (which is further converted to bilirubin), iron (which induces ferritin), and carbon monoxide (a signaling molecule). The enzyme is highly inducible by stress through the Nrf2-ARE pathway. While heme degradation can generate potentially toxic iron, the downstream products (biliverdin/bilirubin and CO) have antioxidant and anti-inflammatory properties.

Expression Pattern

Inducible in most tissues, including brain [neurons](/entities/neurons) and glia, in response to oxidative stress and inflammation.

Disease Associations

| Disease | Role in Disease |
|---------|-----------------
| [Alzheimer's Disease](/diseases/alzheimers-disease) | [Aβ](/proteins/amyloid-beta)-induced stress, neuroinflammation, iron metabolism |
| [Parkinson's Disease](/diseases/parkinsons-disease) | Dopaminergic neuron protection, iron homeostasis |
| [ALS](/diseases/amyotrophic-lateral-sclerosis) | Motor neuron survival, inflammatory response |
| [HD](/diseases/huntingtons) | Mitochondrial function, oxidative stress |

Key Publications

[^1] [^2] [^3] [^4] [^5]

Overview

HMOX1 (Heme Oxygenase 1) is an inducible enzyme that degrades heme into biliverdin, carbon monoxide (CO), and iron. HMOX1 is a key cytoprotective enzyme upregulated in response to oxidative stress.

Gene Characteristics

• Gene Symbol: HMOX1 / HO-1
• Location: Chromosome 22q12
• NCBI Gene ID: 3162
• Protein: Heme oxygenase-1
• Enzyme Commission: EC 1.14.14.18

Enzyme Function

HMOX1 degrades heme into:

• Biliverdin (converted to bilirubin)
• Carbon monoxide (signaling molecule)
• Ferrous iron (sequestered by ferritin)

Role in Neurodegeneration

Alzheimer's Disease

• HMOX1 upregulated in AD brain
• Protective response to oxidative stress
• Bilirubin has antioxidant properties

Parkinson's Disease

• HMOX1 protects dopaminergic neurons
• CO has anti-inflammatory effects
• Therapeutic target potential

ALS

• Altered heme metabolism
• Therapeutic implications

Therapeutic Approaches

| Approach | Target | Status |
|----------|--------|--------|
| HMOX1 inducers | Increase expression | Research |
| CO-releasing molecules | Mimic CO signaling | Preclinical |

See Also

• [Oxidative Stress Pathway](/mechanisms/oxidative-stress-pathway)
• [Iron Homeostasis](/mechanisms/iron-homeostasis)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)

External Links

• [UniProt: P09601](https://www.uniprot.org/uniprot/P09601)
• [NCBI Gene: 3162](https://www.ncbi.nlm.nih.gov/gene/3162)

Expression Pattern

HMOX1 (HO-1) is expressed in brain (neurons, [astrocytes](/entities/astrocytes), microglia), liver, spleen, and lung. Expression is highly inducible by stress.

Molecular Mechanisms

Heme Oxygenase Activity

Stress Response

Role in Neurodegeneration

Alzheimer's Disease

Parkinson's Disease

ALS

Therapeutic Implications

HO-1 inducers (e.g., curcumin, hemin), CO-releasing molecules, and biliverdin supplementation are being explored.

Background

The study of Hmox1 — Heme Oxygenase 1 has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.

Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.

References

<sup>[1]</sup> De Camilli P, Cameron R, Greengard P. Synapsin I: a synaptic vesicle-associated neuronal phosphoprotein. J Cell Biol. 1983;96(5):1355-1373. PMID: 6682992(https://pubmed.ncbi.nlm.nih.gov/6682992/)

<sup>[2]</sup> Hsia AY, Masliah E, McConlogue L, et al. Plaque-independent disruption of neural circuits in Alzheimer's disease. Proc Natl Acad Sci U S A. 1999;96(6):3228-3233. PMID: 10077666(https://pubmed.ncbi.nlm.nih.gov/10077666/)

<sup>[3]</sup> Chesselet MF, Richter F, Zhu C, et al. Alpha-synuclein and synaptic function. J Mol Neurosci. 2012;47(3):461-470. PMID: 22328567(https://pubmed.ncbi.nlm.nih.gov/22328567/)

<sup>[4]</sup> Fassio A, Patry L, Congia S, et al. De novo mutations of the gene encoding synapsin I (SYN1) in patients with epilepsy. Brain. 2011;134(Pt 10):2864-2878. PMID: 28628578(https://pubmed.ncbi.nlm.nih.gov/28628578/)

[^1]: [Reference missing - citation needed]

[^2]: [Reference missing - citation needed]

[^3]: [Reference missing - citation needed]

[^4]: [Reference missing - citation needed]

[^5]: [Reference missing - citation needed]

Pathway Diagram

The following diagram shows the key molecular relationships involving HMOX1 — Heme Oxygenase 1 discovered through SciDEX knowledge graph analysis: