CC improve secretion of FVIII-BDD, FVIII-BDD-eGFP and FVIII-FL <i>in vitro</i>.

<p>Heterologous CHO cells were incubated with CC at different concentrations. FVIII activity was determined in cell supernatants after 72 h by chromogenic assay. (A) Effect of the following CC on human (h)FVIII-BDD secretion: Betaine (100; 50; 25 mM), ectoine (150; 100; 50 mM), trehalose (150; 100; 50 mM), sorbitol (150; 100; 50 mM), taurine (150; 100; 50 mM), trimethylamine N-oxide (TMAO;50; 25; 12,5 mM) and sodium 4-phenylbutyrate (4-PBA; 2; 0,4 mM). Number of experiments, n = 2. (B) Effect of betaine, ectoine, and the endoplasmatic ATPase inhibitors curcumin and thapsigargin on FVIII-.BDD-eGFP secretion. Butylated hydroxyanisole (BHA) is added as treatment control. n = 3. The mean FVIII secretion level ± SD of untreated hFVIII-BDD-eGFP expressing cells was 19±12 IU per 10e6 cells per 72 h. (C) FVIII-BDD-eGFP secretion into cell supernatants over time at different betaine concentrations. n = 3. (D) Influence of betaine, ectoine, curcumin and thapsigargin on FVIII-FL secretion 72 hours following drug supplementation. n = 3. All values are presented as means ± SEM. ANOVA test * <i>P</i><.05; ** <i>P</i><.001.</p

Betaine feeding improves hFVIII and hFIX secretion <i>in vivo</i>.

<p>(A–F) 24 hours post minicircle FVIII-BDD gene transfer the FVIII knockout mice received water without (group I) or with 2% betaine supplementation in the drinking water (group II, each n = 10). After 3 days plasma samples were collected and each group was monitored for human FVIII antigen (A and B) and related activity levels (D and E) and group treatment was switched. After another 3 days, plasma levels were tested again. (C and F) represent the calculated overall effect of betaine on FVIII antigen levels (C) or FVIII activity (D). square symbols indicate samples of the first measuring point, triangles the second one. (G–I) After reaching stable FIX expression levels following minicircle FIX gene transfer, FIX knockout mice were fed 2% Betaine-supplemented drinking water ad libitum in a crossover-study of two groups. After 3 and 17 days of treatment, retroorbitally collected plasma samples were monitored for human FIX antigen levels (G and H). (I) shows the overall change in FIX expression from both groups after 17 days of administration. All values are represented as mean ± SEM. Same symbols indicate samples of the same mouse at different time points; clear: tap water treatment (control), filled: betaine administration. Student’s t-test ((G) ANOVA). *<i>P</i><.05, **<i>P</i><.005, ***<i>P</i><.0005.</p

Rescue of mutant FVIII proteins <i>in vitro</i> and <i>in vivo</i>.

<p>(A–D) HepG2 cells expressing hFVIII muteins were incubated with CC for 72 h. Amount of hFVIII activity in cell supernatant of HepG2 cells expressing hFVIII-BDD Q305P (A and C) or hFVIII-BDD W2313A (B and C) was measured 72 h post betaine treatment. (A and B) show the supplementation of single CC and (C) betaine-ectoine combined treatment. (D) Post CC incubation HepG2 hFVIII-BDDQ305P cells were successively lysed in PBS/0.5% Triton X-100 and PBS/1% SDS. hFVIII antigen was determined in both fractions by indirect ELISA. (E–J) hFVIII-BDDQ305P injected Hem A mice were treated with 2% betaine ad libitum per os in a crossover-study of two groups (each n = 10). After 3 days of treatment hFVIII antigen and activity was measured and treatment was switched between mouse groups. 3 days later, plasma levels were tested again. (E and F) show hFVIII antigen levels, (H and I) the related hFVIII activity levels in plasma of group I or II. (G and J) represent the calculated overall effect of betaine on FVIII antigen levels (G) or FVIII activity (J). square symbols indicate samples of the first measuring point, triangles the second one; clear: tap water-administration (control), filled: 2% betaine administration. (K and L) Endogenous murine FIX levels in all injected FVIII knockout mice (K) and murine FVIII levels of all used FIX knockout mice (L) with and without betaine in the drinking water. Normal mouse levels were set to 100%. Values are presented as means ± SEM. (A–D) ANOVA; (E–H; K–L) Student’s t-test; (I–J) Wilcoxon signed rank test;*<i>P</i><.05, **<i>P</i><.005, ***<i>P</i><.0005.</p

Betaine increases solubility of intracellular FVIII.

<p>CHO cells expressing eGFP-tagged FVIII-BDD protein were incubated with and without betaine. (A,B) Flow cytometry analysis was used to determine the eGFP-signal in untreated cells versus cells treated with betaine or control substance BHA. The mean eGFP intensity (X mean GFP) in the range M1 was used as distinctive parameter. (A) representative histogram after 48 h of treatment and (B) values after 72 h presented as means ± SEM of 3 independent experiments. ANOVA **<i>P</i><.001. (C,D) After 72 h incubation cells were successively lysed in PBS/0.5% Triton X-100 and PBS/1% SDS. (C) FVIII antigen was determined in both fractions by indirect ELISA. (D) Triton X-100-soluble and insoluble fractions were separated on SDS-polyacrylamid gradient gels, and hFVIII light chains (lc), eGFP in hFVIII-single chain (sc) and GAPDH were detected by Western blot. Δ indicates lower band of hFVIII lc doublet.</p