Exosomal Bta-miR-185 and Bta-miR-378 Are Potential Markers for Quality Control of Milk Infected by Staphylococcus aureus

MicroRNAs (miRNA) in milk-derived exosomes may reflect pathophysiological changes caused by mastitis. This study profiled miRNAs in milk exosomes and potential markers for quality control of milk infected by Staphylococcus aureus (S. aureus). Total RNA from milk exosomes was collected from healthy cows (n=3) and S. aureus infected cows (n=6). Two hundred ninety miRNAs (221 known and 69 novel ones) were identified. Among them, 22 known and 15 novel miRNAs were differentially expressed (DE). Target genes of DE miRNAs were significantly enriched in intracellular protein transport, endoplasmic reticulum and identical protein binding. Two miRNAs (bta-miR-378 and bta-miR-185) with high read counts and log2 fold changes (>3.5) were considered as potential milk exosome biomarker miRNAs for S. aureus mastitis and milk quality. One target gene (VAT1L) of bta-miR-378 and five target genes (DYRK1B, MLLT3, HP1BP3, NPR2 and PGM1) of bta-miR-185 were validated. DE miRNAs in exosomes from normal and S. aureus infected milk were identified. Two DE miRNAs could be used as potential biomarkers for the infection. The linkage between the validated target genes and diseases suggest that we should pay particular attention to exosome miRNAs from mastitic milk in terms of milk safety.

Exosomal Bta-miR-185 and Bta-miR-378 Are Potential Markers for Quality Control of Milk Infected by Staphylococcus aureus

MicroRNAs (miRNA) in milk-derived exosomes may reflect pathophysiological changes caused by mastitis. This study profiled miRNAs in milk exosomes and potential markers for quality control of milk infected by Staphylococcus aureus (S. aureus). Total RNA from milk exosomes was collected from healthy cows (n=3) and S. aureus infected cows (n=6). Two hundred ninety miRNAs (221 known and 69 novel ones) were identified. Among them, 22 known and 15 novel miRNAs were differentially expressed (DE). Target genes of DE miRNAs were significantly enriched in intracellular protein transport, endoplasmic reticulum and identical protein binding. Two miRNAs (bta-miR-378 and bta-miR-185) with high read counts and log2 fold changes (>3.5) were considered as potential milk exosome biomarker miRNAs for S. aureus mastitis and milk quality. One target gene (VAT1L) of bta-miR-378 and five target genes (DYRK1B, MLLT3, HP1BP3, NPR2 and PGM1) of bta-miR-185 were validated. DE miRNAs in exosomes from normal and S. aureus infected milk were identified. Two DE miRNAs could be used as potential biomarkers for the infection. The linkage between the validated target genes and diseases suggest that we should pay particular attention to exosome miRNAs from mastitic milk in terms of milk safety.

Extravesicular intraneuronal migration of internalized botulinum neurotoxins without detectable inhibition of distal neurotransmission

Intracellular protein transport routes can be studied using toxins that exploit these to enter cells. BoNTA (botulinum neurotoxin type A) is a protease that binds to peripheral nerve terminals, becomes endocytosed and causes prolonged blockade of transmitter release by cleaving SNAP-25 (synaptosome-associated protein of 25 kDa). Retrograde transport of the toxin has been suggested, but not of the transient muscle relaxant, BoNTE (botulinum neurotoxin type E). In the present study, dispersal of these proteases in compartmented cultures of rat sympathetic neurons was examined after focal application of BoNTA or BoNTE to neurites. A majority of cleaved SNAP-25 was seen locally, but some appeared along neurites and accumulated in the soma over several weeks. BoNTE yielded less cleaved SNAP-25 at distal sites due to shorter-lived enzymic activity. Neurite transection prevented movement of BoNTA. The BoNTA protease could be detected only in the supernatants of neurites or cell body lysates, hence these proteases must move along neuronal processes in the axoplasm or are reversibly associated with membranes. Substitution into BoNTE of the BoNTA acceptor-binding domain did not alter its potency or mobility. Spontaneous or evoked transmission to cell bodies were not inhibited by retrogradely migrated BoNTA except with high doses, concurring with the lack of evidence for a direct central action when used clinically.