Synthesis of the lipid-linked oligosaccharide (LLO), which serves as the sugar donor for the N-glycosylation of secretory proteins, requires conversion of fructose-6-phosphate to mannose-6-phosphate via the phosphomannose isomerase (MPI) enzyme. Individuals who are deficient in MPI present with bleeding,
diarrhea, edema, gastrointestinal bleeding and liver fibrosis. MPI-CDG patients can be treated with oral mannose supplements, which is converted to mannose-6-phosphate through a minor complementary metabolic pathway, restoring protein glycosylation and ameliorating most symptoms, although liver disease continues to progress. Because Mpi deletion in mice causes early embryonic lethality and thus is difficult to study, we used zebrafish to establish a model of Natural Product Library research buy MPI-CDG. We used a morpholino to block mpi mRNA translation and established a concentration that consistently yielded 13% residual Mpi enzyme activity at 4 days post-fertilization (dpf), which is within the range of MPI activity detected in fibroblasts from MPI-CDG patients. Fluorophore-assisted carbohydrate electrophoresis detected decreased LLO and N-glycans in mpi morphants. These deficiencies resulted in 50% embryonic lethality by 4 dpf. Multi-systemic abnormalities, including small eyes, dysmorphic jaws, pericardial edema, a small liver
and curled tails, occurred in 82% of the surviving larvae. Importantly, these phenotypes could be rescued with mannose supplementation. Thus, parallel processes in fish and humans contribute to the phenotypes caused by Mpi depletion. Interestingly, mannose was only effective if provided prior FDA-approved Drug Library ic50 to 24 hpf. These data provide insight into treatment efficacy and the broader molecular and developmental abnormalities that contribute to disorders associated with
defective protein glycosylation.”
“Diclazuril, a benzeneacetonitrile Belnacasan anticoccidial agent, has potent activity against various stages of Eimeria tenella (E. tenella). To study the effects of diclazuril on E. tenella merozoites, purified second-generation merozoites were obtained from infected chicken caecal tissue at 120 h after inoculation by a combination of enzymatic digestion, centrifugation, erythrocytes disruption and percoll density gradient centrifugation. Ultrastructural changes were monitored by transmission electron microscopy (TEM). Apoptosis and mitochondrial transmembrane potential were determined by flow cytometry (FCM). The results showed that diclazuril induced ultrastructural changes and significantly increased the ratio of early apoptosis by 180.75% (P<0.01) and late apoptosis/necrosis by 86.82% (P<0.05) in second-generation merozoites, respectively. Compared with the infected/control group, the ratio of second-generation merozoites that lost mitochondrial function was increased by 45.04% (P<0.01) in the infected/treatment group.