Dimitrios Karamichos, Ph.D.
Permanent URI for this communityhttps://hdl.handle.net/20.500.12503/31785
Executive Director and Endowed Chair, North Texas Eye Research Institute
Professor, Pharmaceutical Sciences
Professor, Pharmacology & Neuroscience
Email: Dimitrios.Karamichos@unthsc.edu
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Browsing Dimitrios Karamichos, Ph.D. by Author "Escandon, Paulina"
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Item Salivary Exosomes in Health and Disease: Future Prospects in the Eye(MDPI, 2023-04-14) Liu, Angela; Hefley, Brenna; Escandon, Paulina; Nicholas, Sarah E.; Karamichos, DimitriosExosomes are a group of vesicles that package and transport DNA, RNA, proteins, and lipids to recipient cells. They can be derived from blood, saliva, urine, and/or other biological tissues. Their impact on several diseases, such as neurodegenerative, autoimmune, and ocular diseases, have been reported, but not fully unraveled. The exosomes that are derived from saliva are less studied, but offer significant advantages over exosomes from other sources, due to their accessibility and ease of collection. Thus, their role in the pathophysiology of diseases is largely unknown. In the context of ocular diseases, salivary exosomes have been under-utilized, thus creating an enormous gap in the literature. The current review discusses the state of exosomes research on systemic and ocular diseases and highlights the role and potential of salivary exosomes as future ocular therapeutic vehicles.Item The Role of Estriol and Estrone in Keratoconic Stromal Sex Hormone Receptors(MDPI, 2022-01-14) Escandon, Paulina; Nicholas, Sarah E.; Cunningham, Rebecca L.; Murphy, David A.; Riaz, Kamran M.; Karamichos, DimitriosKeratoconus (KC) is a progressive corneal thinning disease that manifests in puberty and worsens during pregnancy. KC onset and progression are attributed to diverse factors that include: environmental, genetics, and hormonal imbalances; however, the pathobiology remains elusive. This study aims to determine the role of corneal stroma sex hormone receptors in KC and their interplay with estrone (E1) and estriol (E3) using our established 3D in vitro model. Healthy cornea stromal cells (HCFs) and KC cornea stromal cells (HKCs), both male and female, were stimulated with various concentrations of E1 and E3. Significant changes were observed between cell types, as well as between males and females in the sex hormone receptors tested; androgen receptor (AR), progesterone receptor (PR), estrogen receptor alpha (ERalpha), and estrogen receptor beta (ERbeta) using Western blot analysis. E1 and E3 stimulations in HCF females showed AR, PR, and ERbeta were significantly upregulated compared to HCF males. In contrast, ERalpha and ERbeta had significantly higher expression in HKC's females than HKC's males. Our data suggest that the human cornea is a sex-dependent, hormone-responsive tissue that is significantly influenced by E1 and E3. Therefore, it is plausible that E1, E3, and sex hormone receptors are involved in the KC pathobiology, warranting further investigation.Item Unravelling Novel Roles of Salivary Exosomes in the Regulation of Human Corneal Stromal Cell Migration and Wound Healing(MDPI, 2022-04-14) Escandon, Paulina; Liu, Angela; Nicholas, Sarah E.; Khan, Asher; Riaz, Kamran M.; Karamichos, DimitriosSalivary exosomes have demonstrated vast therapeutic and diagnostic potential in numerous diseases. This study pioneers previously unexplored roles of SE in the context of corneal wound healing by utilizing primary corneal stromal cells from healthy (HCFs), type I diabetes mellitus (T1DMs), type II DM (T2DMs), and keratoconus (HKCs) subjects. Purified, healthy human SEs carrying tetraspanins CD9+, CD63+, and CD81+ were utilized. Scratch and cell migration assays were performed after 0, 6, 12, 24, and 48 h following SE stimulation (5 and 25 microg/mL). Significantly slower wound closure was observed at 6 and 12 h in HCFs with 5 mug/mL SE and T1DMs with 5 and 25 mug/mL SE. All wounds were closed by 24-hour, post-wounding. HKCs, T1DMs, and T2DMs with 25microg/mL SE exhibited a significant upregulation of cleaved vimentin compared to controls. Thrombospondin 1 was significantly upregulated in HCFs, HKCs, and T2DMs with 25 microg/mL SE. Lastly, HKCs, T1DMs, and T2DMs exhibited a significant downregulation of fibronectin with 25 mug/mL SE. Whether SEs can be utilized to clinical settings in restoring corneal defects is unknown. This is the first-ever study exploring the role of SEs in corneal wound healing. While the sample size was small, results are highly novel and provide a strong foundation for future studies.