From rare familial mutations to multifactorial disease: aldo-keto reductase 1C enzymes as a central biological pathway in lipedema
Abstract
The discovery of pathogenic variants in AKR1C1 and AKR1C2 in ultra-rare familial lipedema highlights steroid hormone metabolism as a core mechanism affecting about 11% of women during reproductive age. Lipedema represents a complex disease shaped by the interplay between rare mutations, common regulatory variants, and environmental exposures. This review outlines how ultra-rare monogenic mutations can illuminate the genetic and environmental bases of multifactorial lipedema.
A systematic literature review (2000-2025) was performed using PubMed, Web of Science, and Google Scholar. Studies were identified with MeSH and keyword searches including lipedema, AKR1C1, AKR1C2, steroid metabolism, adipose tissue, obesogens, epigenetics, polycyclic aromatic hydrocarbons, endocrine disrupting chemicals, air pollution, and dietary hormones.
The AKR1C1 p.Leu213Gln loss-of-function variant decreases progesterone inactivation by ~50% due to catalytic domain destabilization, leading to local progesterone accumulation. AKR1C2 gain-of-function variants and overexpression, found in 24% of cases, enhance DHT inactivation, converting it to 3α-androstanediol and suppressing anti-adipogenic androgen signaling. Population screening revealed three AKR1C1 polymorphisms associated with increased lipedema risk. The AKR1C2 regulatory variant rs28571848 in a glucocorticoid receptor site elevates AKR1C2/AKR1C3 expression and trunk fat mass independently of BMI. Environmental agents such as polycyclic aromatic hydrocarbons activate AKR1C1 via Nrf2-ARE signaling (3-10-fold induction), while steroid hormones promote adipocyte differentiation.
Lipedema arises from an interaction between genetic susceptibility and environmental factors. Understanding the AKR1C pathway clarifies how genetic variants and obesogens disrupt steroid metabolism and induce epigenetic reprogramming, leading to clinical manifestations.
Keywords
References
- 1. Cifarelli V. Lipedema: progress, challenges, and the road ahead. Obes Rev 2025;26:e13953. DOI: https://doi.org/10.1111/obr.13953
- 2. Morgan S, Reid I, Bendon C, et al. A family-based study of inherited genetic risk in lipedema. Lymphat Res Biol 2024;22:106-11. DOI: https://doi.org/10.1089/lrb.2023.0065
- 3. Kaftalli J, Bonetti G, Marceddu G, et al. AKR1C1 and hormone metabolism in lipedema pathogenesis: a computational biology approach. Eur Rev Med Pharmacol Sci 2023;27:137-47.
- 4. Kruglikov IL, Joffin N, Scherer PE. The MMP14-caveolin axis and its potential relevance for lipoedema. Nat Rev Endocrinol 2020;16:669-74. DOI: https://doi.org/10.1038/s41574-020-0395-z
- 5. Lüchinger JE, Pavicic E, Giachino CL, Stute P. Impact of hormones on lipedema development: a systematic literature review. Arch Gynecol Obstet 2026;313:60. DOI: https://doi.org/10.1007/s00404-026-08318-1
- 6. Forner-Cordero I, Szolnoky G, Forner-Cordero A, Kemény L. Lipedema: an overview of its clinical manifestations, diagnosis and treatment of the disproportional fatty deposition syndrome - systematic review. Clin Obes 2012;2:86-95. DOI: https://doi.org/10.1111/j.1758-8111.2012.00045.x
- 7. Choudhary S, Dubey A, Singh A, et al. Engineering the microenvironment: advanced biomaterials for humanized in vitro immunotoxicology and carcinogenicity assessment. Explor BioMat-X 2025;2:101351. DOI: https://doi.org/10.37349/ebmx.2025.101351
- 8. Langendoen SI, Habbema L, Nijsten TEC, Neumann HAM. Lipoedema: from clinical presentation to therapy. A review of the literature. Br J Dermatol 2009;161:980-6. DOI: https://doi.org/10.1111/j.1365-2133.2009.09413.x
- 9. Okhovat JP, Alavi A. Lipedema. Int J Low Extrem Wounds 2015;14:262-7. DOI: https://doi.org/10.1177/1534734614554284
- 10. Tomlinson DJ, Erskine RM, Morse CI, et al. The impact of obesity on skeletal muscle strength and structure through adolescence to old age. Biogerontology 2016;17:467-83. DOI: https://doi.org/10.1007/s10522-015-9626-4
- 11. Buso G, Depairon M, Tomson D, et al. Lipedema: a call to action! Obesity (Silver Spring) 2019;27:1567-76. DOI: https://doi.org/10.1002/oby.22597
- 12. Mortada H, Alhithlool AW, AlBattal NZ, et al. Lipedema: clinical features, diagnosis, and management. Arch Plast Surg 2025;52:185-96. DOI: https://doi.org/10.1055/a-2530-5875
- 13. Child AH, Gordon KD, Sharpe P, et al. Lipedema: an inherited condition. Am J Med Genet A 2010;152A:970-6. DOI: https://doi.org/10.1002/ajmg.a.33313
- 14. Michelini S, Herbst KL, Precone V, et al. A multi-gene panel to identify lipedema-predisposing genetic variants by a next-generation sequencing strategy. J Pers Med 2022;12:268. DOI: https://doi.org/10.3390/jpm12020268
- 15. Klimentidis YC, Chen Z, Gonzalez-Garay ML, et al. Genome-wide association study of a lipedema phenotype among women in the UK Biobank identifies multiple genetic risk factors. Eur J Hum Genet 2023;31:338-44. DOI: https://doi.org/10.1038/s41431-022-01231-6
- 16. Zakeri M, Safaiee MS, Taheri F, et al. Secondary findings from whole-exome sequencing data in families with familial combined hyperlipidemia (FCHL). Egypt J Med Hum Genet 2021;22:79. DOI: https://doi.org/10.1186/s43042-021-00195-4
- 17. Santella B, Salvati A, Papp A, et al. Epigenetic alterations of AKT1 orchestrate a metabolic reprogramming in advanced lipedema: translational insights from an integrated multi-omics study. J Transl Med 2026;24:265. DOI: https://doi.org/10.1186/s12967-026-07726-w
- 18. Katzer K, Hill JL, McIver KB, Foster MT. Lipedema and the potential role of estrogen in excessive adipose tissue accumulation. Int J Mol Sci 2021;22:11720. DOI: https://doi.org/10.3390/ijms222111720
- 19. Kaftalli J, Donato K, Bonetti G, et al. Aldo-keto reductase 1C2 (AKR1C2) as the second gene associated to non-syndromic primary lipedema: investigating activating mutation or overexpression as causative factors. Eur Rev Med Pharmacol Sci 2023;27:13227-35.
- 20. Blouin K, Veilleux A, Luu-The V, Tchernof A. Androgen metabolism in adipose tissue: recent advances. Mol Cell Endocrinol 2009;301:97-103. DOI: https://doi.org/10.1016/j.mce.2008.10.035
- 21. Ostinelli G, Vijay J, Vohl MC, et al. AKR1C2 and AKR1C3 expression in adipose tissue: association with body fat distribution and regulatory variants. Mol Cell Endocrinol 2021;527:111220. DOI: https://doi.org/10.1016/j.mce.2021.111220
- 22. Ostinelli G, Ramalho A, Gauthier MF, et al. Impact of AKR1C2 and AKR1C3 single-nucleotide polymorphism rs28571848 in adipose tissues of individuals with severe obesity. Am J Physiol Endocrinol Metab 2026;330:E276-86.
- 23. Blouin K, Nadeau M, Mailloux J, et al. Pathways of adipose tissue androgen metabolism in women: depot differences and modulation by adipogenesis. Am J Physiol Endocrinol Metab 2009;296:E244-55. DOI: https://doi.org/10.1152/ajpendo.00039.2008
- 24. Blouin K, Blanchette S, Richard C, et al. Expression and activity of steroid aldoketoreductases 1C in omental adipose tissue are positive correlates of adiposity in women. Am J Physiol Endocrinol Metab 2005;288:E398-404. DOI: https://doi.org/10.1152/ajpendo.00312.2004
- 25. Burczynski ME, Lin HK, Penning TM. Isoform-specific induction of a human aldo-keto reductase by polycyclic aromatic hydrocarbons (PAHs), electrophiles, and oxidative stress: implications for the alternative pathway of PAH activation catalyzed by human dihydrodiol dehydrogenase. Cancer Res 1999;59:607-14.
- 26. Chivukula N, Madgaonkar SR, Marigoudar SR, et al. TICToK: a comprehensive knowledgebase of tattoo ink chemicals and investigation of their associated toxicities and regulations. 2025. Available from: https://www.biorxiv.org/content/10.1101/2025.08.02.668261v1.full DOI: https://doi.org/10.1101/2025.08.02.668261
- 27. Penning TM. Aldo-keto reductase regulation by the Nrf2 system: implications for stress response, chemotherapy drug resistance, and carcinogenesis. Chem Res Toxicol 2017;30:162-76. DOI: https://doi.org/10.1021/acs.chemrestox.6b00319
- 28. Duan C, Fang Y, Sun J, et al. Effects of fast food packaging plasticizers and their metabolites on steroid hormone synthesis in H295R cells. Sci Total Environ 2020;726:138500. DOI: https://doi.org/10.1016/j.scitotenv.2020.138500
- 29. Pötzl B, Kürzinger L, Kendl S, et al. Disruptive effects of plasticizers bisphenol A, F, and S on steroidogenesis of adrenocortical cells. Front Endocrinol 2024;15:1387133. DOI: https://doi.org/10.3389/fendo.2024.1387133
- 30. Galbraith H. Hormones in international meat production: biological, sociological and consumer issues. Nutr Res Rev 2002;15:293-314. DOI: https://doi.org/10.1079/NRR200246
- 31. Andersson AM, Skakkebaek NE. Exposure to exogenous estrogens in food: possible impact on human development and health. Eur J Endocrinol 1999;140:477-85. DOI: https://doi.org/10.1530/eje.0.1400477
- 32. Wang X, Karvonen-Gutierrez CA, Gold EB, et al. Longitudinal associations of air pollution with body size and composition in midlife women: the Study of Women's Health Across the Nation. Diabetes Care 2022;45:2577-84. DOI: https://doi.org/10.2337/dc22-0963
- 33. Furlong MA, Klimentidis YC. Associations of air pollution with obesity and body fat percentage, and modification by polygenic risk score for BMI in the UK Biobank. Environ Res 2020;185:109364. DOI: https://doi.org/10.1016/j.envres.2020.109364
- 34. Luta X, Buso G, Porceddu E, et al. Clinical characteristics, comorbidities, and correlation with advanced lipedema stages: a retrospective study from a Swiss referral centre. PLoS One 2025;20:e0319099. DOI: https://doi.org/10.1371/journal.pone.0319099
- 35. Kiani AK, Mor M, Bernini A, et al. Steroid-converting enzymes in human adipose tissues and fat deposition with a focus on AKR1C enzymes. Eur Rev Med Pharmacol Sci 2021;25:7698-706.
- 36. Stel J, Legler J. The role of epigenetics in the latent effects of early life exposure to obesogenic endocrine disrupting chemicals. Endocrinology 2015;156:3466-72. DOI: https://doi.org/10.1210/en.2015-1434
- 37. Heindel JJ, Howard S, Agay-Shay K, et al. Obesity II: establishing causal links between chemical exposures and obesity. Biochem Pharmacol 2022;199:115015. DOI: https://doi.org/10.1016/j.bcp.2022.115015
- 38. Janesick AS, Blumberg B. Obesogens: an emerging threat to public health. Am J Obstet Gynecol 2016;214:559-65. DOI: https://doi.org/10.1016/j.ajog.2016.01.182
- 39. Penning TM, Wangtrakuldee P, Auchus RJ. Structural and functional biology of aldo-keto reductase steroid-transforming enzymes. Endocr Rev 2019;40:447-75. DOI: https://doi.org/10.1210/er.2018-00089
- 40. Veilleux A, Côté JA, Blouin K, et al. Glucocorticoid-induced androgen inactivation by aldo-keto reductase 1C2 promotes adipogenesis in human preadipocytes. Am J Physiol Endocrinol Metab 2012;302:E941-9. DOI: https://doi.org/10.1152/ajpendo.00069.2011
- 41. Tchernof A, Mansour MF, Pelletier M, et al. Updated survey of the steroid-converting enzymes in human adipose tissues. J Steroid Biochem Mol Biol 2015;147:56-69. DOI: https://doi.org/10.1016/j.jsbmb.2014.11.011
- 42. Rižner TL, Penning TM. Role of aldo-keto reductase family 1 (AKR1) enzymes in human steroid metabolism. Steroids 2014;79:49-63. DOI: https://doi.org/10.1016/j.steroids.2013.10.012
- 43. Eretta C, Di Pumpo F, Bizzarri S, et al. Does lymphoscintigraphy have a role in the diagnosis and management of lipedema? Veins Lymphat 2025;14:14438. DOI: https://doi.org/10.4081/vl.2025.14438
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