APOPT1 is a gene regulating the important process of programmed cell death, known as apoptosis. Operating within the APOPT family, APOPT1 plays a crucial role in orchestrating mitochondria-induced cell death, particularly in vascular smooth muscle cells.
This pivotal function underscores APOPT1's significance in regulating cellular fate and maintaining tissue homeostasis.
Delving into its molecular intricacies and clinical implications offers promising insights into diagnostic and therapeutic strategies targeting apoptotic pathways. This article navigates through the definition, function, and clinical relevance of APOPT1 to outline its impact on cellular biology and human health.
APOPT1, a member of the APOPT family, is a gene encoding a protein that lies on the inner mitochondrial membrane.
APOPT1 is intricately linked to the proper assembly and function of cytochrome c oxidase (COX), a crucial enzyme complex in the mitochondrial respiratory chain responsible for cellular energy production. COX deficiency is one of the most common presentations of mitochondrial disease, indicating APOPT1’s importance as a regulator of mitochondrial function.
It operates primarily in vascular smooth muscle cells, orchestrating mitochondria-induced apoptosis by facilitating the release of cytochrome c from mitochondria.
The APOPT1 gene, while initially hypothesized to be involved in apoptosis regulation, is now understood to primarily function in maintaining the integrity of the mitochondrial respiratory chain rather than directly modulating cell death processes.
Studies have shown that APOPT1 does not play a significant role in apoptosis regulation, contrasting with its early characterization. [8.] Instead, its primary function lies in the maintenance of the mitochondrial respiratory chain, particularly in ensuring the proper assembly and function of cytochrome c oxidase (COX), a key enzyme complex involved in cellular energy production.
The importance of APOPT1 in mitochondrial function is highlighted by the manifestation of isolated COX deficiency in multiple tissues upon its ablation in mice, emphasizing its indispensable role in mitochondrial respiratory chain integrity. [8.]
APOPT1 deficiency has been associated with cavitating leukodystrophy, a rare neurological disorder characterized by abnormal changes in the white matter of the brain.
APOPT1 deficiency is commonly diagnosed in infancy or early childhood, typically when affected individuals present with symptoms such as developmental delay, seizures, or abnormal neurological findings. However, people diagnosed with this condition can survive for decades. [6.]
Clinical manifestations of this disease include progressive neurological deterioration, such as motor and cognitive impairment, seizures, and vision loss.
Studies have shown that mutations in the APOPT1 gene lead to defective mitochondrial function, disrupting cellular energy metabolism and contributing to the pathogenesis of cavitating leukodystrophy. [6.]
Testing for APOPT1 mutations typically involves specialized genetic testing. Additionally, biochemical assays may be conducted to assess mitochondrial function, particularly focusing on the activity of cytochrome c oxidase (COX), as APOPT1 mutations are associated with COX deficiency.
Consulting with a genetic counselor or healthcare provider can help determine the most appropriate testing option based on the individual's clinical presentation and family history.
Mitochondrial function is essential for overall health and wellness. The following therapies are excellent to support general mitochondrial health:
Creatine: supports cellular energy metabolism, benefiting mitochondrial function. [5.]
Pyrroloquinoline quinone (PQQ): promotes mitochondrial biogenesis and protects against oxidative damage. [1.]
Resveratrol: provides antioxidant support and may improve mitochondrial function. [2.]
N-acetylcysteine (NAC): boosts glutathione levels, protecting mitochondria from damage. [7.]
Magnesium: essential for ATP synthesis and mitochondrial function. [4.]
Regular exercise: promotes mitochondrial biogenesis and overall mitochondrial health. [9.]
Healthy diet: eating a plant-based diet such as the Mediterranean diet, which is rich in antioxidants, vitamins, minerals, and healthy fats, supports mitochondrial function and cellular energy production. [3.]
Coenzyme Q10 (CoQ10): an antioxidant that supports mitochondrial energy production.
L-carnitine: facilitates fatty acid transport into mitochondria for energy production.
Riboflavin (vitamin B2): essential for mitochondrial function and energy metabolism.
Thiamine (vitamin B1): supports mitochondrial energy production and overall cellular function.
Vitamin C: acts as an antioxidant, protecting mitochondria from oxidative stress.
Temporary improvement with steroids: steroids may provide temporary relief by reducing inflammation associated with mitochondrial disorders.
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[3.] Khalil M, Shanmugam H, Abdallah H, John Britto JS, Galerati I, Gómez-Ambrosi J, Frühbeck G, Portincasa P. The Potential of the Mediterranean Diet to Improve Mitochondrial Function in Experimental Models of Obesity and Metabolic Syndrome. Nutrients. 2022 Jul 28;14(15):3112. doi: 10.3390/nu14153112. PMID: 35956289; PMCID: PMC9370259.
[4.] Liu M, Jeong EM, Liu H, Xie A, So EY, Shi G, Jeong GE, Zhou A, Dudley SC Jr. Magnesium supplementation improves diabetic mitochondrial and cardiac diastolic function. JCI Insight. 2019 Jan 10;4(1):e123182. doi: 10.1172/jci.insight.123182. PMID: 30626750; PMCID: PMC6485371.
[5.] Marshall RP, Droste JN, Giessing J, Kreider RB. Role of Creatine Supplementation in Conditions Involving Mitochondrial Dysfunction: A Narrative Review. Nutrients. 2022 Jan 26;14(3):529. doi: 10.3390/nu14030529. PMID: 35276888; PMCID: PMC8838971.
[6.] Melchionda L, Haack TB, Hardy S, Abbink TE, Fernandez-Vizarra E, Lamantea E, Marchet S, Morandi L, Moggio M, Carrozzo R, Torraco A, Diodato D, Strom TM, Meitinger T, Tekturk P, Yapici Z, Al-Murshedi F, Stevens R, Rodenburg RJ, Lamperti C, Ardissone A, Moroni I, Uziel G, Prokisch H, Taylor RW, Bertini E, van der Knaap MS, Ghezzi D, Zeviani M. Mutations in APOPT1, encoding a mitochondrial protein, cause cavitating leukoencephalopathy with cytochrome c oxidase deficiency. Am J Hum Genet. 2014 Sep 4;95(3):315-25. doi: 10.1016/j.ajhg.2014.08.003. Epub 2014 Aug 28. PMID: 25175347; PMCID: PMC4157140.
[7.] Mohammadi E, Farnaz Nikbakht, Barati M, et al. Protective effect of N-acetyl cysteine on the mitochondrial dynamic imbalance in temporal lobe epilepsy: Possible role of mTOR. Neuropeptides. 2022;96:102294-102294. doi:https://doi.org/10.1016/j.npep.2022.102294
[8.] Signes A, Cerutti R, Dickson A, et al. APOPT 1/ COA 8 assists COX assembly and is oppositely regulated by UPS and ROS. EMBO Molecular Medicine. 2018;11(1). doi:https://doi.org/10.15252/emmm.201809582
[9.] Sorriento D, Di Vaia E, Iaccarino G. Physical Exercise: A Novel Tool to Protect Mitochondrial Health. Front Physiol. 2021 Apr 27;12:660068. doi: 10.3389/fphys.2021.660068. PMID: 33986694; PMCID: PMC8110831.