Gene expression profiling of human primary astrocytes exposed to manganese chloride indicates selective effects on several functions of the cells.
Exposure of adult humans to manganese (Mn) has long been known to cause neurotoxicity. Recent evidence also suggests that exposure of children to Mn is associated with developmental neurotoxicity. Astrocytes are critical for the proper functioning of the nervous system, and they play active roles in neurogenesis, synaptogenesis and synaptic neurotransmission. In this report, to help elucidate the molecular events underlying Mn neurotoxicity, we systematically identified the molecular targets of Mn in primary human astrocytes at a genome-wide level, by using microarray gene expression profiling and computational data analysis algorithms. We found that Mn altered the expression of diverse genes ranging from those encoding cytokines and transporters to signal transducers and transcriptional regulators. Particularly, 28 genes encoding proinflammatory chemokines, cytokines and related functions were up-regulated, whereas 15 genes encoding functions involved in DNA replication and repair and cell cycle checkpoint control were down-regulated. Consistent with the increased expression of proinflammatory factors, analysis of common regulators revealed that 16 targets known to be positively affected by the interferon-gamma signaling pathway were up-regulated by Mn(2+). In addition, 68 genes were found to be similarly up- or down-regulated by both Mn(2+) and hypoxia. These results from genomic analysis are further supported by data from real-time RT-PCR, Western blotting, flow cytometric and toxicological analyses. Together, these analyses show that Mn(2+) selectively affects cell cycle progression, the expression of hypoxia-responsive genes, and the expression of proinflammatory factors in primary human astrocytes. These results provide important insights into the molecular mechanisms underlying Mn neurotoxicity.
Sengupta
Amitabha
A
Department of Environmental Health Sciences, Columbia University, Mailman School of Public Health, 60 Haven Avenue, New York, NY 10032, USA.
Mense
Sarah M
SM
Lan
Changgui
C
Zhou
Mei
M
Mauro
Rory E
RE
Kellerman
Lisa
L
Bentsman
Galina
G
Volsky
David J
DJ
Louis
Elan D
ED
Graziano
Joseph H
JH
Zhang
Li
L
D001253:Astrocytes / Q000187:drug effects*; D015153:Blotting, Western; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics; D002453:Cell Cycle / Q000187:drug effects; D015687:Cell Hypoxia / Q000235:genetics; D002478:Cells, Cultured; D002712:Chlorides / Q000633:toxicity*; D004260:DNA Repair / Q000187:drug effects; D004261:DNA Replication / Q000187:drug effects; D004815:Epidermal Growth Factor / Q000096:biosynthesis / Q000235:genetics; D005434:Flow Cytometry; D015870:Gene Expression / Q000187:drug effects; D020869:Gene Expression Profiling; D006801:Humans; D007111:Immunity, Cellular / Q000187:drug effects; D007249:Inflammation / Q000235:genetics; D007371:Interferon-gamma / Q000096:biosynthesis; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D017895:Manganese Compounds; D020411:Oligonucleotide Array Sequence Analysis; D012313:RNA / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D014158:Transcription, Genetic; D015854:Up-Regulation / Q000187:drug effects
D002352:Carrier Proteins; D002712:Chlorides; D017895:Manganese Compounds; D004815:Epidermal Growth Factor; D012313:RNA; D007371:Interferon-gamma; D007770:L-Lactate Dehydrogenase; C025340:manganese chloride