Journal: bioRxiv
Article Title: The 677C>T variant in methylenetetrahydrofolate reductase causes morphological and functional cerebrovascular deficits in mice
doi: 10.1101/2021.12.16.472805
Figure Lengend Snippet: ( A ) Numerous cell types in the brain express Mthfr . Data obtained from the Brain RNA-seq database. ( B ) Single cell sequencing showing expression of Mthfr in cerebrovascular and perivascular cells. Data obtained from the Single-Cell RNA-seq Gene Expression Data. AC= astrocytes, N= neurons, OPC= oligodendrocyte precursor cells, NFO= newly formed oligodendrocytes, MO= myelinating oligodendrocytes, MG= microglia, MAC= macrophages, EC= endothelial cells, PC= pericytes, vSMC= venous smooth muscle cells, aaSMC= arteriolar smooth muscle cells, aSMC= arterial smooth muscle cells, FB1= fibroblast-like type 1, FB2= fibroblastlike type 2, OL= oligodendrocytes, EC1= endothelial cell type 1, EC2= endothelial cell type 2, EC3= endothelial cell type 3, vEC= venous endothelial cells, capilEC= capillary endothelial cells, aEC= arterial endothelial cells. ( C ) MTHFR enzymatic activity measured in brain tissue. Both males and females show significantly reduced activity based on genotype (n=4-6/sex/genotype; P=<0.0001, One-way ANOVA, Tukey post-hoc). ( D ) In brains of female mice, total MTHFR is significantly reduced in both the CT and TT groups (left; n=6/genotype; P=0.0002, One-way ANOVA). Enzymatic activity is correlated with MTHFR protein expression (right; correlation with activity, P=0.0001 Pearson r=0.7896). ( E ) Brain-derived metabolite levels: THF= tetrahydrofolic acid, DHF= dihydrofolic acid, 5-MTHF= 5-methyltetrahydrofolate, SAM= S-Adenosyl methionine, SAH= S-Adenosylhomocysteine. DHF (P= <0.0001; 95% CI {0.09381 to 0.1738}), 5-MTHF (P= <0.0001; 95% CI {-0.1831 to −0.07584}), SAM (P= <0.0001; 95% CI {-17.52 to −13.76}), SAH (P= <0.0001; 95% CI {6.445 to 8.966}) methionine (P= <0.0001; 95% CI {270.3 to 369.9}) and choline (P= <0.0001 95% CI {1107 to 1324}) demonstrate significant sex-differences, while THF (P= 0.0007; 95% CI {-0.2728 to 0.2883}), 5-MTHF (P= 0.0075; 95% CI {-0.1831 to −0.07584}), cystathionine (P= 0.0031 95%CI {1.798 to 25.69}) and betaine (P= 0.0086 95% CI {-7.633 to 3.749}) show genotype-specific differences (n=4-6/sex/genotype; Two-way ANOVA, Tukey post-hoc).
Article Snippet: Crude protein extract was prepared from 80 – 100 mg of frozen liver, ( n =6/sex/genotype, except TT males; n =4) and whole half brain ( n =6/genotype) in extraction buffer (50 mM potassium phosphate pH 7.2, 50 mM sucrose, 0.3 mM EDTA containing protease and phosphatase inhibitors (Pierce Protease Inhibitor Tablet and Halt Phosphatase Inhibitor Cocktail, ThermoScientific catalog numbers A32955 and 78420)) using a bead mill with steel beads (2 x 2 min at 20 Hz; TissueLyser, Qiagen).
Techniques: RNA Sequencing Assay, Sequencing, Expressing, Activity Assay, Derivative Assay