id_1005. PROTECTING THE BRAIN BY STRENGTHENING BIOLOGICAL BARRIERS: YOLKIN AND OVOCYSTATIN AS REGULATORS OF THE GUT–BRAIN AXIS
Agnieszka Zabłocka1, Bartłomiej Stańczykiewicz2, Dominika Jakubczyk1, Sabina Górska1, Krzysztof Gołąb3, Józefa Macała1, Błażej Misiak2
1 Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Laboratory of Microbiome Immunobiology, R. Weigla 12, 53-114, Wroclaw, Poland
2 Division of Consultation Psychiatry and Neuroscience, Department of Psychiatry, Wroclaw Medical University, Pasteura 10 Street, 50-367 Wroclaw, Poland
3 Department of Pharmaceutical Biochemistry, Division of Pharmaceutical Biochemistry, Wroclaw Medical University, Borowska 211 A, 50-556 Wroclaw, Poland.
INTRODUCTION: The integrity of biological barriers within the gut–brain axis, including the intestinal epithelium (IE) and brain microvascular endothelium (BME), is crucial for maintaining brain homeostasis. Barrier disruption and increased permeability are linked to neuroinflammation and impaired brain function. Egg-derived proteins, such as the yolkin polypeptide complex and ovocystatin, show immunomodulatory and protective effects, yet their impact on gut and brain barriers is not fully understood.
AIM(S): To evaluate whether yolkin and ovocystatin can support intestinal and blood–brain barrier integrity and function.
METHOD(S): Yolkin and ovocystatin were isolated from hen eggs. HT29 and HBEC5i cell lines modelled intestinal and brain barriers. Cell viability and cytotoxicity were assessed via MTT and LDH assays. Barrier integrity was analyzed using TEER and paracellular permeability measurements. Secretion of pro- and anti-inflammatory mediators was measured with ELISA and multiplex immunoassays.
RESULTS: Neither protein affected viability or induced cytotoxicity. Both modulated barrier integrity and permeability under normal and inflammatory conditions, with distinct patterns. Yolkin and ovocystatin selectively stimulated IL-1β and IL-8 secretion. Under inflammatory conditions, they also modulated cytokines, chemokines, and neurotrophic factor release.
CONCLUSIONS: Yolkin and ovocystatin are non-toxic to HT29 and HBEC5i cells and actively influence gut and blood–brain barrier function by regulating permeability and secretory activity. These findings support their potential as nutraceuticals to preserve barrier integrity and brain homeostasis during immune challenges.