Publications co-authored by students
Matthew J. Reynolds, Tanaporn Phetruen, Rebecca L. Fisher, Ke Chen,
Brian T. Pentecost, George Gomez, Puey Ounjai, and Haixin Sui. 2018. The developmental process of the
growing motile ciliary tip region. Scientific Reports 8:7977
In this study, we characterized the process of cilium formation (ciliogenesis) by investigating the newly
developed motile cilia of deciliated protists using complementary techniques in electron microscopy
and image analysis. Our results demonstrated that the distal tip region of motile cilia exhibit
progressive morphological changes as cilia develop. This developmental process is time-dependent
and continues after growing cilia reach their full lengths. The structural analysis of growing ciliary tips
revealed that B-tubules of axonemal microtubule doublets terminate far away from the tip end, which
is led by the flagellar tip complex (FTC), demonstrating that the FTC might not directly mediate the fast
turnover of intraflagellar transport (IFT).
Harasym, E., McAndrew, N.,and Gomez, G. 2017. Sub-micromolar concentrations of retinoic acid induce morphological and functional neuronal phenotypes in SK-N-SH neuroblastoma cells. In Vitro Cell Dev. Biol.-Anim. 53:789-809
This study showed how SK-N-SH neuroblastoma cells (HTB-11) differentiate into neuron-like cells when grown exposed to submicromolar conentrations of retinoic acid. They demonstrate both structural (molecular marker expression) and functional (stimulus elicited changes in intracellular calcium) properties. This study has important implications for the study of both cancer and nerve cell differentiation.
Chen-Liaw, A.Y., Hammel, G., Gomez, G. 2017. Inhibition of Exendin-4-induced steatosis by protein kinase A in cultured HepG2 human hepatoma cells. In Vitro Cell Dev. Biol.-Anim. 53:721-727.
The research focused on how Exendin-4 induces a partial reduction in triglycerides in cultured steatotic hepatocytes within 12 hours via the GLP-1 receptor mediated activation of protein kinase A. Thus, the reduction in hepatocyte triglyceride accumulation is likely driven primarily by downregulation of lipogenesis and upregulation of β-oxidation of free fatty acids.
O’Neill, G., Musto, C., Gomez, G. 2017. Chronic odorant exposure upregulates acquisition of functional properties in cultured embryonic chick olfactory sensory neurons. J. Neurosci. Res. 95: 1216-1224.
This paper focused on how odorant exposure upregulates the development of structural and functional properties of cultured chick olfactory neurons: they increase expression of canonical marker molecules, and are more sensitive to odorants to which they were exposed. This suggest that stimulus-induced sensory neural differentiation can be modulated peripherally, independent from influence of the brain.
Yazinski, S.A., Gomez, G. 2014. Timecourse of structural and functional maturation of human olfactory epithelial cells in vitro. J. Neurosci. Res. 92:64-73.
In this study, we investigated the timeline of the development of olfactory signaling cascades in cultured human olfactory cells. We cultured human olfactory cells and tested them with both functional (calcium imaging) and immunocytochemical techniques over time to correlate the development of both structural and functional attributes of these cells. Using this approach, we determined that human cells in vitro gain the full ability to respond to neurons within five days, and that this developmental timecourse is asynchronous with the expression of proteins that are typically used for identifying maturation in the olfactory system. The findings of this study have important implications for the use of cultured human olfactory cells as a tool for the study of the biochemistry and physiology of human olfaction.
Greco, A.A., Gomez, G. 2014. Differential effects of hypoxic and hyperoxic stress-induced hypertrophy in cultured chick fetal cardiac myocytes. In Vitro Cell. Dev. Biol. Anim. 50: 129-138.
In this study, we investigated the effects of hyperoxia and hypoxia on isolated chick cardiac myocytes in vitro. We looked at both structural properties (muscle protein expression) and functional properties (calcium fluxes induced by pharmacological agents) to determine whether hypertrophic growth induced by the different treatments were regulated and expressed at the cellular level. Our findings show that while both hypoxia and hyperoxia lead to hypertrophic growth, these two treatments results in different functional properties within 3 days of treatment. The in vitro approach was critical for our study: it allowed us to isolate the effects that were exerted at the single cell level versus those that occur in functional syncitia that are typical of cardiac tissue.
DeNunzio, M., Gomez, G. 2014. Extracellular glutathione promotes migration of hydrogen peroxide-stressed cultured chick embryonic skin cells. In Vitro Cell. Dev. Biol. Anim., 50: 350-357.
Oxidative stress impedes cellular processes such as migration (necessary for wound healing). In this study, we investigated the effects of extracellularly applied glutathione on the migration rate of chick embryonic fibroblasts using an in vitro scratch assay. We found that the repair rate of a scratched fibroblast monolayer is significantly enhanced by glutathione. In addition, when fibroblast scratches are conducted under oxidative stress conditions, their migration is effectively eliminated, but is rescued by the presence of extracellular glutathione. These effects are most likely exerted through the mechanism that mediates the formation of cell adhesions, as shown by our quantification of the amount and distribution of focal adhesions in the cells exposed to the different conditions in our experiment.
Gomez, G., Celii, A. 2008. The peripheral olfactory system of the domestic chicken: physiology and development. Brain Res Bull. 76:208-216.
This work was the paper written for the International Brain Research Organization (IBRO) conference on the Bird Brain. It was a review work on olfaction in birds (focusing on the chicken as a representative model system). Amanda's work focused on how exposure to odorants in the egg modulates the development of the olfactory bulb in the chick egg.
Jung, Y., Wirkus, E., Amendola, D., Gomez, G. 2005. Characteristics of odorant elicited calcium fluxes in acutely-isolated chick olfactory neurons. J. Comp. Physiol. A. 191: 511-520.
In this research work, we investigated the properties of odorant-elicited calcium changes in acutely isolated chick olfactory neurons using calcium imaging. This approach allowed us to compare physiological features of chick olfactory neurons to those found in other vertebrates. We found that chick olfactory neurons possess a number of physiological properties common to those found in other species, such as the ability to encode odorants with increases or decreases in intracellular calcium, and pharmacological evidence for the involvement of two distinct signal transduction pathways. We also found some features that are unique to chicks: different odorants can elicit increases or decreases in intracellular calcium in the same cell, implying that these peripheral neurons may play a greater role in processing olfactory information than previously supposed.