Propionic Acid and Fasudil as Treatment against Rotenone Toxicity in an In Vitro Model of Parkinson’s Disease

Parkinson’s disease (PD) is a multifactorial neurodegenerative disease. In recent years, several studies demonstrated that the gastroenteric system and intestinal microbiome influence central nervous system function. The pathological mechanisms triggered thereby change neuronal function in neurodegenerative diseases including dopaminergic neurons in Parkinson´s disease. In this study, we employed a model system for PD of cultured primary mesencephalic cells and used the pesticide rotenone to model dopaminergic cell damage. We examined neuroprotective effects of the Rho kinase inhibitor Fasudil and the short chain fatty acid (SCFA) propionic acid on primary neurons in cell morphological assays, cell survival, gene and protein expression. Fasudil application resulted in significantly enhanced neuritic outgrowth and increased cell survival of dopaminergic cells. The application of propionic acid primarily promoted cell survival of dopaminergic cells against rotenone toxicity and increased neurite outgrowth to a moderate extent. Interestingly, Fasudil augmented gene expression of synaptophysin whereas gene expression levels of tyrosine hydroxylase (TH) were substantially increased by propionic acid. Concerning protein expression propionic acid treatment increased STAT3 levels but did not lead to an increased phosphorylation indicative of pathway activation. Our findings indicate that both Fasudil and propionic acid treatment show beneficial potential in rotenone-lesioned primary mesencephalic cells.

Immunoreactivity of estrogen receptor alpha in brain and ovary of the short mackerel Rastrelliger brachysoma (Bleeker, 1851)

The reproductive physiology concerning the gonadotropin hormone (GTH) and its downstream target estrogen receptor alpha (ERα) is not well understood in the short mackerel Rastrelliger brachysoma, an economically important marine fish in Thailand. In this study, we tested the hypothesis that the expression of both GTH and ERα in the brain and ovary of R. brachysoma was as reported in other fish species. By applying immunohistochemical techniques, we identified the distribution of ERα-immunoreactive (ir) neurons in the brain and ovary of wild female R. brachysoma during the spawning season along with the distribution of GTHs-ir cells in the ovary. The nucleus lateralis tuberis in the diencephalon had a high number of ERα-ir neurons. In the mesencephalon, dense ERα-ir neuronal fibers were mainly found in the mesencephalic cells, stratum opticum, stratum fibrosum et griseum superficiale and stratum album centrale. Both the valvula and corpus cerebelli in the metencephalon contained ERα-ir neurons in granular and Purkinje cell layers as well as the molecular layer. The ERα-ir neurons were also observed in the medulla oblongata. In the ovary, weak ERα and moderate GTHs immunoreactivities were observed in follicular cells of oocytes in early and late vitellogenic stages. This information provides baseline data required to understand not only the activity of estrogen (E2) on the brain but also the regulatory mechanism of the hypothalamo-pituitary-ovarian axis of R. brachysoma.