TY - JOUR
T1 - Cytotoxic activity of Flavobacterium psychrophilum in skeletal muscle cells of rainbow trout (Oncorhynchus mykiss)
AU - Iturriaga, Mathias
AU - Espinoza, Marlen Brisa
AU - Poblete-Morales, Matías
AU - Feijoo, Carmen Gloria
AU - Reyes, Ariel E.
AU - Molina, Alfredo
AU - Avendaño-Herrera, Ruben
AU - Valdés, Juan Antonio
N1 - Funding Information:
This work was supported by the National Commission for Scientific and Technological Research [grant number CONICYT/FONDAP 15110027 and FONDECYT 1171318] and the Universidad Andrés Bello [grant number Núcleo DI-447-13/N ].
PY - 2017/10/1
Y1 - 2017/10/1
N2 - Flavobacterium psychrophilum is the etiologic agent of bacterial coldwater disease (BCWD) and rainbow trout fry syndrome (RTFS), which cause significant worldwide losses in aquaculture. Juvenile rainbow trout are particularly susceptible to F. psychrophilum infection, the main external clinical signs of which are extensive necrotic myositis and ulcerative lesions. Despite the economic relevance of this pathogen in aquaculture, little is known about the molecular mechanisms underlying F. psychrophilum infection and pathogenesis. In this study, cultured skeletal muscle cells from rainbow trout (Oncorhynchus mykiss) were co-incubated with the virulent strain of F. psychrophilum JIP02/86 (ATCC 49511). Trypan blue exclusion analysis at 48 h post-incubation revealed decreased cellular viability. Direct bacteria-myoblast contact was found a key factor in inducing F. psychrophilum cytotoxicity. Apoptosis was characterized by nuclear DNA fragmentation, decreased plasma membrane integrity, increased caspase activity, and the proteolytic cleavage of poly(ADP-ribose)polymerase-1 (PARP-1). Moreover, bacterial infection induced an early inhibition of NF-κB signaling, as well as a differential expression of the pro- and anti-apoptotic genes, bax and bcl-2. These findings suggest that F. psychrophilum induces rainbow trout muscle apoptosis through the modulation of the NF-κB signaling as a mechanism for nutrient acquisition and survival.
AB - Flavobacterium psychrophilum is the etiologic agent of bacterial coldwater disease (BCWD) and rainbow trout fry syndrome (RTFS), which cause significant worldwide losses in aquaculture. Juvenile rainbow trout are particularly susceptible to F. psychrophilum infection, the main external clinical signs of which are extensive necrotic myositis and ulcerative lesions. Despite the economic relevance of this pathogen in aquaculture, little is known about the molecular mechanisms underlying F. psychrophilum infection and pathogenesis. In this study, cultured skeletal muscle cells from rainbow trout (Oncorhynchus mykiss) were co-incubated with the virulent strain of F. psychrophilum JIP02/86 (ATCC 49511). Trypan blue exclusion analysis at 48 h post-incubation revealed decreased cellular viability. Direct bacteria-myoblast contact was found a key factor in inducing F. psychrophilum cytotoxicity. Apoptosis was characterized by nuclear DNA fragmentation, decreased plasma membrane integrity, increased caspase activity, and the proteolytic cleavage of poly(ADP-ribose)polymerase-1 (PARP-1). Moreover, bacterial infection induced an early inhibition of NF-κB signaling, as well as a differential expression of the pro- and anti-apoptotic genes, bax and bcl-2. These findings suggest that F. psychrophilum induces rainbow trout muscle apoptosis through the modulation of the NF-κB signaling as a mechanism for nutrient acquisition and survival.
KW - Apoptosis
KW - Flavobacterium psychrophilum
KW - Rainbow trout
KW - Skeletal muscle
UR - http://www.scopus.com/inward/record.url?scp=85029508404&partnerID=8YFLogxK
U2 - 10.1016/j.vetmic.2017.09.009
DO - 10.1016/j.vetmic.2017.09.009
M3 - Article
AN - SCOPUS:85029508404
SN - 0378-1135
VL - 210
SP - 101
EP - 106
JO - Veterinary Microbiology
JF - Veterinary Microbiology
ER -