Received: 22 December 2017 | Accepted: 12 January 2018 DOI: 10.1002/jcp.26486 ORIGINAL RESEARCH ARTICLE Effect of sex steroid hormone fluctuations in the pathophysiology of male-retinal pigment epithelial cells Carlo Astarita 1,2 | Barbara D’ Angelo-Maansson 1 | Mina Massaro-Giordano 3 | Maria P. Alba 1 | Silvia Boffo 1 | Ilaria Macchi 3,4 | Antonio Giordano 1,2 | Marcella Macaluso 1 1 Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, College of Science and Technology, Temple University, Philadelphia, Pennsylvania 2 Department of Medicine, Surgery, and Neuroscience, University of Siena, Siena, Italy 3 Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 4 University Campus Bio-Medico of Rome, Rome, Italy Correspondence Antonio Giordano, Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy 1900 N 12th Street, Biolife BLDG, Suite 431, Philadelphia, PA 19122. Email: giordano@temple.edu Marcella Macaluso, Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, College of Science and Technology, Temple University, Philadelphia, Pennsylvania1900 N 12th Street, Biolife BLDG, Suite 429A, Philadelphia, PA 19122. Email: macaluso@temple.edu Funding information Pennsylvania Department of Health for Sbarro Health Research Organization (SHRO); The Dry Eye Research Fund and The Douglas Charitable Trust Gender-based differences may influence the occurrence of several ocular conditions suggesting the possibility that fluctuations in sex steroid homeostasis may have direct effects on the eye physiology. Here, we evaluated the effect of sex steroid hormone fluctuations in male retinal pigment epithelial cells, RPEs (ARPE-19). To mimic hormonal fluctuations occurring during aging, we exposed ARPE-19 to acute, prolonged or chronic estradiol, and progesterone challenges. We found that chronic estradiol treatment promotes a remarkable necrosis of RPE cells, and does not affect pRb2/p130 or PAI-2 sub- cellular localization. In contrast, chronic progesterone exposure induces nuclear subcellular rearrangement of pRb2/p130, co-immunolocalization of pRb2/p130 with PAI-2, and accumulation of cells in G2/M phase, which is accompanied by a remarkable reduction of necrosis in favour of apoptosis activation. This study has a high clinical significance since it considers sex steroid fluctuations as inducers of milieu change in the retina able to influence pathological situations occurring with aging in non-reproductive systems such as the eye. Exogenous administration of physiologically significant amounts of sex hormones for long periods of time is a common clinical practice for transgender patients seeking sex reassignment. In particular, our study offers the unique opportunity to unravel the effects of sex hormones, not only in determining gender differences but also in affecting the physiology of non-reproductive systems, such as the eye, in the underserved transgender community. Carlo Astarita and Barbara D’Angelo contributed equally to the work. J Cell Physiol. 2018;233:6965–6974. wileyonlinelibrary.com/journal/jcp | 6965 © 2018 Wiley Periodicals, Inc.