TY  - JOUR
A1  - Ruszkiewicz, Joanna A.
A1  - de Macedo, Gabriel Teixeira
A1  - Miranda-Vizuete, Antonio
A1  - Teixeira da Rocha, Joao B.
A1  - Bowman, Aaron B.
A1  - Bornhorst, Julia
A1  - Schwerdtle, Tanja
A1  - Aschner, Michael
T1  - The cytoplasmic thioredoxin system in Caenorhabditis elegans affords protection from methylmercury in an age-specific manner
JF  - Neurotoxicology : the interdisciplinary journal of effects to toxic substances on the nervous system
N2  - Methylmercury (MeHg) is an environmental pollutant linked to many neurological defects, especially in developing individuals. The thioredoxin (TRX) system is a key redox regulator affected by MeHg toxicity, however the mechanisms and consequences of MeHg-induced dysfunction are not completely understood. This study evaluated the role of the TRX system in C. elegans susceptibility to MeHg during development. Worms lacking or overexpressing proteins from the TRX family were exposed to MeHg for 1 h at different developmental stage: L1, L4 and adult. Worms without cytoplasmic thioredoxin system exhibited age-specific susceptibility to MeHg when compared to wild-type (wt). This susceptibility corresponded partially to decreased total glutathione (GSH) levels and enhanced degeneration of dopaminergic neurons. In contrast, the overexpression of the cytoplasmic system TRX-1/TRXR-1 did not provide substantial protection against MeHg. Moreover, transgenic worms exhibited decreased protein expression for cytoplasmic thioredoxin reductase (TRXR-1). Both mitochondrial thioredoxin system TRX-2/TRXR-2, as well as other thioredoxin-like proteins: TRX-3, TRX-4, TRX-5 did not show significant role in C. elegans resistance to MeHg. Based on the current findings, the cytoplasmic thioredoxin system TRX-1/TRXR-1 emerges as an important age-sensitive protectant against MeHg toxicity in C. elegans.
KW  - Methylmercury
KW  - Age
KW  - Development
KW  - C. elegans
KW  - Thioredoxin
KW  - Thioredoxin reductase
Y1  - 2018
U6  - https://doi.org/10.1016/j.neuro.2018.08.007
SN  - 0161-813X
SN  - 1872-9711
VL  - 68
SP  - 189
EP  - 202
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Fischer, Stefan
A1  - Spierling, Nastasja G.
A1  - Heuser, Elisa
A1  - Kling, Christopher
A1  - Schmidt, Sabrina
A1  - Rosenfeld, Ulrike M.
A1  - Reil, Daniela
A1  - Imholt, Christian
A1  - Jacob, Jens
A1  - Ulrich, Rainer G.
A1  - Essbauer, Sandra
T1  - High prevalence of Rickettsia helvetica in wild small mammal populations in Germany
JF  - Ticks and Tick-borne Diseases
N2  - Since the beginning of the 21st century, spotted fever rickettsioses are known as emerging diseases worldwide. Rickettsiae are obligately intracellular bacteria transmitted by arthropod vectors. The ecology of Rickettsia species has not been investigated in detail, but small mammals are considered to play a role as reservoirs. Aim of this study was to monitor rickettsiae in wild small mammals over a period of five years in four federal states of Germany. Initial screening of ear pinna tissues of 3939 animals by Pan-Rick real-time PCR targeting the citrate synthase (gltA) gene revealed 296 rodents of seven species and 19 shrews of two species positive for rickettsial DNA. Outer membrane protein gene (ompB, ompAIV) PCRs based typing resulted in the identification of three species: Rickettsia helvetica (90.9%) was found as the dominantly occurring species in the four investigated federal states, but Rickettsia felis (7.8%) and Rickettsia raoultii (1.3%) were also detected. The prevalence of Rickettsia spp. in rodents of the genus Apodemus was found to be higher (approximately 14%) than in all other rodent and shrew species at all investigated sites. General linear mixed model analyses indicated that heavier (older) individuals of yellow-necked mice and male common voles seem to contain more often rickettsial DNA than younger ones. Furthermore, rodents generally collected in forests in summer and autumn more often carried rickettsial DNA. In conclusion, this study indicated a high prevalence of R. helvetica in small mammal populations and suggests an age-dependent increase of the DNA prevalence in some of the species and in animals originating from forest habitats. The finding of R. helvetica and R. felis DNA in multiple small mammal species may indicate frequent trans-species transmission by feeding of vectors on different species. Further investigations should target the reason for the discrepancy between the high rickettsial DNA prevalence in rodents and the so far almost absence of clinical apparent human infections.
KW  - Rickettsia helvetica
KW  - Rodent
KW  - Germany
KW  - Age
KW  - Reproduction
KW  - Season
Y1  - 2018
U6  - https://doi.org/10.1016/j.ttbdis.2018.01.009
SN  - 1877-959X
SN  - 1877-9603
VL  - 9
IS  - 3
SP  - 500
EP  - 505
PB  - Elsevier GMBH
CY  - München
ER  -