Novel insight into FCSK-congenital disorder of glycosylation through a CRISPR-generated cell model.

BACKGROUND: FCSK-congenital disorder of glycosylation (FCSK-CDG) is a recently discovered rare autosomal recessive genetic disorder with defective fucosylation due to mutations in the fucokinase encoding gene, FCSK. Despite the essential role of fucokinase in the fucose salvage pathway and severe multisystem manifestations of FCSK-CDG patients, it is not elucidated which cells or which types of fucosylation are affected by its deficiency. METHODS: In this study, CRISPR/Cas9 was employed to construct an FCSK-CDG cell model and explore the molecular mechanisms of the disease by lectin flow cytometry and real-time PCR analyses. RESULTS: Comparison of cellular fucosylation by lectin flow cytometry in the created CRISPR/Cas9 FCSK knockout and the same unedited cell lines showed no significant change in the amount of cell surface fucosylated glycans, which is consistent with the only documented previous study on different cell types. It suggests a probable effect of this disease on secretory glycoproteins. Investigating O-fucosylation by analysis of the NOTCH3 gene expression as a potential target revealed a significant decrease in the FCSK knockout cells compared with the same unedited ones, proving the effect of fucokinase deficiency on EGF-like repeats O-fucosylation. CONCLUSION: This study expands insight into the FCSK-CDG molecular mechanism; to the best of our knowledge, it is the first research conducted to reveal a gene whose expression level alters due to this disease.

The significance of surface neutrophilic MPO expression level in NETosis and NETosis-associated coagulopathies in covid-19 infected patients.

INTRODUCTION: Inflammatory response-induced coagulopathy is a common complication associated with severe form of covid-19 infection. Evidences suggest that neutrophil extracellular traps (NETs) play a significant role in triggering the immunothrombosis in this condition. We aimed to evaluate the diagnostic value of surface neutrophilic myeloperoxidase (MPO) as NETosis biomarker for predicting the risk of covid-19-associated coagulopathies. METHODS: Covid-19 infection was assessed by real-time-PCR and plasma d-dimer levels were measured by ELFA. Based on the covid-19 infection and d-dimer level outcomes, patients were categorized into four groups. Any alteration in the serum level of IL-6, H3Cit and neutrophilic surface MPO were analyzed by CLIA, ELISA, and flow cytometry, respectively. RESULTS: H3Cit variations and different d-dimer values confirmed the association between NETosis and coagulopathies. Findings showed that the expression of neutrophilic MPO reduced in cases with NETosis, which was correlated with increased levels of H3Cit. ANC/MPO ratio was signified as a valuable marker to discriminate the covid-19 and non covid-19-associated coagulopathies and could be considered as a prognostic factor due to its noteworthy correlation with serum IL-6 concentration. CONCLUSION: Declined levels of surface neutrophilic MPO in NETosis correlate with covid-19-associated coagulopathies and increased IL-6 levels, as a potential biomarker of covid-19 disease severity.