Ingrid Medina
Affiliated to Research
E-mail: ingrid.medina@ki.se
Visiting address: Nobels väg 13, 17177 Stockholm
Postal address: C6 Institutet för miljömedicin, C6 Systemtoxikologi Vincent, 171 77 Stockholm
About me
- Ingrid Medina is a postdoctoral researcher at the Institute of Environmental
Medicine, Unit of Systems Toxicology at Karolinska Institutet.
She obtained the PhD degree in Biomedical Sciences at National Autonomous
University of Mexico (UNAM) in 2019 evaluating the toxicity of titanium
dioxide nanoparticles after inhalation. Then, she worked for two-years as
postdoc evaluating the gastrointestinal toxicity induced by titanium dioxide
as food additive.
In 2021 she joined Emma Wincent´s group to study the role of
AHR/CYP1-feedback signaling in intestinal barrier homeostasis.
Research
- The aryl hydrocarbon receptor (AHR) is a transcription factor that mediates
the toxicity of xenobiotics such as dioxins, polychlorinated biphenyls, and
polycyclic aromatic hydrocarbons. Although AHR has been well described as a
mediator of toxicity, it has recently been shown that AHR is also involved in
various physiological functions, particularly in barrier organs such as the
skin, lungs, and intestine.
The intestinal epithelium is continuously renewed from crypt stem cells that
differentiate into specialized epithelial cells generating the intestinal
barrier. The integrity of this intestinal barrier has substantial
implications for health even beyond the intestine, and several internal and
environmental factors play a significant, but mechanistically poorly
understood, role in intestinal homeostasis.
The ongoing project aims to clarify the differential signaling pathways
triggered by AHR upon activation by physiological versus xenobiotic ligands,
to elucidate the mechanisms underlying the dual role of the AHR in intestinal
barrier homeostasis and thereby gastrointestinal toxicity and diseases.
To investigate the role of AHR in the process of crypt stem cell
proliferation and differentiation, mouse models as well as intestinal
organoid cultures have been developed in collaboration with the research
group of Brigitta Stockinger at the Francis Crick Institute.
*Publications*
Food-grade titanium dioxide (E171) induces anxiety, adenomas in colon and
goblet cells hyperplasia in a regular diet model and microvesicular steatosis
in a high fat diet model. [1] *Medina-Reyes EI*, Delgado-Buenrostro NL,
Díaz-Urbina D, Rodríguez-Ibarra C, Déciga-Alcaraz A, González MI, Reyes
JL, Villamar-Duque TE, Flores-Sánchez ML, Hernández-Pando R, Mancilla-Díaz
JM, Chirino YI, Pedraza-Chaverri J.Food Chem Toxicol. 2020 Dec - 146:111786.
doi: 10.1016/j.fct.2020.111786.
Food additives containing nanoparticles induce gastrotoxicity, hepatotoxicity
and alterations in animal behavior: The unknown role of oxidative stress.
[2] *Medina-Reyes EI*, Rodríguez-Ibarra C, Déciga-Alcaraz A, Díaz-Urbina
D, Chirino YI, Pedraza-Chaverri J.Food Chem Toxicol. 2020 Dec - 146:111814
Differences in cytotoxicity of lung epithelial cells exposed to titanium
dioxide nanofibers and nanoparticles: Comparison of air-liquid interface and
submerged cell cultures. [3] *Medina-Reyes EI*, Delgado-Buenrostro NL,
Leseman DL, Déciga-Alcaraz A, He R, Gremmer ER, Fokkens PHB, Flores-Flores
JO, Cassee FR, Chirino YI.Toxicol In Vitro. 2020 Jun - 65:104798.
Food-grade titanium dioxide (E171) by solid or liquid matrix administration
induces inflammation, germ cells sloughing in seminiferous tubules and
blood-testis barrier disruption in mice. [4] Rodríguez-Escamilla
JC, *Medina-Reyes EI*, Rodríguez-Ibarra C, Déciga-Alcaraz A, Flores-Flores
JO, Ganem-Rondero A, Rodríguez-Sosa M, Terrazas LI, Delgado-Buenrostro NL,
Chirino YI.J Appl Toxicol. 2019 Nov - 39(11):1586-1605.
[1] https://pubmed.ncbi.nlm.nih.gov/33038453/
[2] https://pubmed.ncbi.nlm.nih.gov/33068655/
[3] https://pubmed.ncbi.nlm.nih.gov/32084520/
[4] https://pubmed.ncbi.nlm.nih.gov/31415109/