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Relationship: 881
Title
Decreased, Peroxisomal Fatty Acid Beta Oxidation of Fatty Acids leads to Decreased, Mitochondrial Fatty Acid Beta Oxidation
Upstream event
Downstream event
AOPs Referencing Relationship
Taxonomic Applicability
| Term | Scientific Term | Evidence | Link |
|---|---|---|---|
| human | Homo sapiens | Moderate | NCBI |
Sex Applicability
| Sex | Evidence |
|---|---|
| Male | Moderate |
| Female | Moderate |
Life Stage Applicability
| Term | Evidence |
|---|---|
| Not Otherwise Specified | Not Specified |
Peroxisomes participate in a variety of lipid metabolic pathways including the beta-oxidation of very long-straight chain (<20 C in length) or branched –chain acyl-CoAs (Lazarow 1978, Kersten 2014). The peroxisomal beta-oxidation pathway is not directly coupled to the electron transport chain and oxidative phosporylation, therefore the first oxidation reaction loses energy to heat (H2O2 production) while in the second step, energy is captured in the metabolically accessible form of high-energy electrons in NADH (Mannaerts and Van Veldhoven 1993, Desvergne and Wahli 1999). The peroxisomal beta-oxidation pathway provides fatty acid chain shortening where two carbons are removed in each round of oxidation in the form of acetyl-CoA (Desvergne and Wahli 1999). The shortened chain fatty acids (<20C) can then be transported to the mitochondria to undergo mitochondrial beta-oxidation for complete metabolism of the carbon substrate for cellular energy production (Desvergne and Wahli 1999). Mitochondrial beta-oxidation catabolizes short, medium and long chain fatty acids (<C20) into acetyl-CoA and ATP. The production of acetyl-CoA monomers is important as they serve as fundamental units for metabolic energy production (ATP) via the citric acid cycle followed by electron-transport chain mediated oxidative phosphorylation (Nelson and Cox, 2000A). Acetyl-CoA is also a fundamental units of energy storage via gluconeogenesis (Nelson and Cox, 2000B) and lipogenesis (Nelson and Cox, 2000C).
| ID | Experimental Design | Species | Upstream Observation | Downstream Observation | Citation (first author, year) | Notes |
|---|
| Title | First Author | Biological Plausibility |
Dose Concordance |
Temporal Concordance |
Incidence Concordance |
|---|
Biological Plausibility
Dose Concordance Evidence
Temporal Concordance Evidence
Incidence Concordance Evidence
Uncertainties and Inconsistencies
The degree to which the KE, “peroxisomal fatty acid beta oxidation of fatty acids” contributes to the KE, “mitochondrial fatty acid beta oxidation” under a broad range of nutrient levels and types is not well characterized.
Is it known how much change in the first event is needed to impact the second? Are there known modulators of the response-response relationships? Are there models or extrapolation approaches that help describe those relationships?
As discussed in the previous sections, the degree to which the KE, “peroxisomal fatty acid beta oxidation of fatty acids” contributes to the KE, “mitochondrial fatty acid beta oxidation” is not well described, neither are modulators of the response-response relationship. We are not currently aware of any models available to extrapolate results among KEs.
Response-response Relationship
Time-scale
Known Feedforward/Feedback loops influencing this KER
The evidence provided is primarily derived from human and rodent models.