TheMT1GGene in LUHMES Neurons Is a Sensitive Biomarker of Neurotoxicity
NEUROTOXICITY RESEARCH
Authors: Tong, Zhi-Bin; Braisted, John; Chu, Pei-Hsuan; Gerhold, David
Abstract
Identification of toxicants that underlie neurological diseases is a neglected area awaiting a valid strategy to identify such toxicants. We sought biomarkers that respond to known neurotoxicants in LUHMES immortalized neurons and evaluated these biomarkers for use in screening libraries of environmental toxicants. LUHMES immortalized human dopaminergic neurons were surveyed by RNA sequencing following challenge with parkinsonian toxicants rotenone, 6-hydroxydopamine, MPP+, and ziram (zinc dimethyldithiocarbamate; Zn2+DDC2), as well as additional toxicants paraquat, MS275, and methylmercury. The metallothionein geneMT1Gwas the most dynamic gene expression response to all seven toxicants. Multiple toxicants also increased transcripts forSLC30A1andSLC30A2zinc secretion transporters, theSLC7A11xCT cystine/glutamate antiporter important for glutathione synthesis, DNA damage inducible transcript 3 (DDIT3), and secreted growth factorsFIBINandCXCL12, whereas several toxicants decreased expression of the apelin growth factor (APLN). These biomarker genes revealed stress responses to many toxicants at sub-cytotoxic concentrations. Since several of these biomarker genes and prior neurological disease studies implicated disruption of metal distribution, we tested metal chelator thiram (dimethyldithiocarbamate, DDC), ziram, and several other metals and metal chelates for cytotoxicity and induction ofMT1Gexpression. Metals and chelators that caused dynamic increases inMT1Gexpression also caused cytotoxicity, except Ni(2+)DDC(2)inducedMT1Gat 5 mu M, but lacked cytotoxicity up to 100 mu M. These results bolster prior work suggesting that neurons are characteristically sensitive to depletion of glutathione or to disruption of cellular metal distribution and provide biomarkers to search for such neurotoxicants in chemical libraries.
Apelin system detection in the reproductive apparatus of ewes grazing on semi-natural pasture
THERIOGENOLOGY
Authors: Mercati, Francesca; Scocco, Paola; Maranesi, Margherita; Acuti, Gabriele; Petrucci, Linda; Cocci, Paolo; Renzi, Asia; De Felice, Elena; Dall'Aglio, Cecilia
Abstract
Apelin (APLN) is an adipokine with pleiotropic effects involved in the regulation of metabolic, cardiovascular, immune, and electrolyte balance function. Recent studies demonstrated a pivotal role in the regulation of male and female reproduction. APLN and its receptor (APLNR) were found in the hypothalamic-pituitary-gonad axis tissues, regulating gonadotropin release and steroidogenesis. However, to date, there are no studies that describe APLN system in the reproductive apparatus of the sheep. The study was performed on 10 Comisana x Appenninica adult dry ewes reared in a semi-natural pasture. Organ samples were collected from five animals in the two pasture functional phases: after maximum pasture flowering (Group 1) and after maximum pasture dryness (Group 2). Experiments were devised to characterize the gene expression and protein localization of the APLN/APLNR system in ewe reproductive apparatus; in addition, the concentration of plasma APLN was evaluated during the trial. Through immunohistochemical analysis, a positive staining for APLN was observed in the large luteal cells, in the epithelial cell coat of the ampulla, in the uterus epithelial lining and in the uterine glands. APLNR was observed in the granulosa cells, in the large luteal cells, in the secreting cells of the ampulla, in the uterus epithelial lining and uterine glands. The transcripts for APLN and APLNR were evidenced in all organ tissues examined. The highest level of APLN mRNA was detected in the Group 2 ewes in the luteal phase of the ovarian cycle compared to Group 1 ewes in the anestrous one. The relative content of APLN transcript was respectively twofold higher in the ovary (P < 0.05) and uterus (P < 0.05) and threefold higher in the ampulla (P < 0.05) in the Group 2 vs Group 1. The same trend of APLN transcript was evaluated for APLNR mRNA in uterus (P < 0.05) and ovary (P < 0.05). No difference was evidenced between Group 1 and Group 2 for APLNR mRNA levels. The plasma APLN level was fairly constant during the trial period. In conclusion, the present data suggest that the apelinergic system is involved in the reproduction function of ewes, being differentially distributed and expressed in the organs of the reproductive apparatus of ewes; these variations could be related to the sexual cycle and to the cyclic activity of the reproductive apparatus. (C) 2019 Elsevier Inc. All rights reserved.