Redox imbalance in peripheral blood of type 1 myotonic dystrophy patients

Figures & data

Figure 1. Antioxidant enzyme activities in erythrocytes from DM1 patients (n = 30) and HCs (n = 15). Results are expressed as mean ± SE and compared by t-test. ***P < 0.001, **P < 0.01.

Figure 2. Native PAGE gel stained for SOD1 enzyme activity with NBT. Lanes, from left to right: HCs; HCs + H₂O₂; DM1 and DM1 + H₂O₂. Histogram presents quantitative analysis of SOD activity. Graphs represent % from SOD activity HCs taken as 100% (±SE). Statistical analysis showed a more pronounced reduction in activity after H₂O₂ treatment of DM1 SOD compared with to HC SOD (***P < 0.001; n = 7, vs. *P < 0.05; n = 5). Note the difference between samples with respect to relative band intensity (in-gel SOD1 activity). For details, see ‘Methods’ section.

Table 1 The activity of antioxidant enzymes in DM1 patients with different severity of muscle impairment

	SOD1	CAT	GSH-Px	GR
HCs (n = 15)	3.0 ± 0.2a	26.9 ± 2.2	24.3 ± 1.4	8.1 ± 0.5
DM1 MIRS II (n = 4)	2.5 ± 0.2ab	18.9 ± 3	22.3 ± 1.4	7.9 ± 0.7
DM1 MIRS III (n = 11)	1.6 ± 0.2b	20.8 ± 2.3	24.5 ± 2.1	8.8 ± 1.0
DM1 MIRS IV (n = 11)	1.9 ± 0.2b	20.7 ± 2.2	22.7 ± 1.7	9.0 ± 1.0
DM1 MIRS V (n = 4)	2.3 ± 0.3ab	15.7 ± 0.2	26.3 ± 1.2	8.6 ± 1.0
ANOVA	P < 0.001	N.S.	N.S.	N.S.

Results are expressed as mean ± SE and tested by one-way ANOVA followed by Tukey's HSD test (different letters (a) or (b) mean statistical significant difference between groups; (_ab) means no significant difference in comparison with the other groups). N.S. — not significant.

Table 2 Comparison of antioxidant defense in HCs and DM1 patients with normal and increased CK values

	SOD1	CAT	GSH-Px	GR
HCs (n = 15)	3.04 ± 0.24a	27 ± 2a	24.3 ± 1.4	8.1 ± 0.5
DM1 patients – CK normal	1.88 ± 0.21b	22.2 ± 2.2ab	22.7 ± 2	9.2 ± 1.2
DM1 patients – CK increased	1.91 ± 0.18b	19.8 ± 1.8b	25.6 ± 1.3	8.4 ± 0.5
ANOVA	P < 0.001	P < 0.05	N.S.	N.S.

Results are expressed as mean ± SE and tested by one-way ANOVA followed by Tukey's HSD test (different letters (a) or (b) mean statistical significant difference between groups; (ab) means no significant difference in comparison with the other groups). N.S. – not significant.

Table 3 Correlation analysis of different clinical parameters with activity of antioxidant enzymes in DM1 patients (n = 30)

	Age of onset	MIRS	CK	Disease duration	Age	Duration/age	CTG number	SOD1	CAT	GSH-Px	GR
Age of onset
MIRS	−0.06
CK	−0.30	−0.10
Disease duration	−0.32	0.44*	0.09
Age	0.60**	0.32	−0.18	0.57**
Duration/age	−0.64***	0.36	0.14	0.88***	0.18
CTG number	−0.42	0.06	0.17	−0.07	−0.40	0.21
SOD1	0.15	−0.07	0.18	0.15	0.25	−0.01	−0.31
CAT	−0.18	−0.04	0.12	0.25	0.07	0.21	0.36	0.19
GSH-Px	0.18	0.05	0.17	0.14	0.27	−0.05	0.27	0.34	0.71***
GR	−0.04	0.08	−0.16	0.42*	0.01	0.31	0.17	−0.01	0.39*	0.47*

Pearson correlation coefficients are shown.

*P < 0.05.

**P < 0.01.

***P < 0.001.

Figure 3. Canonical discriminant analysis of the activity of antioxidant enzymes in different forms of DM1 according to (A) different severity of MIRS and (B) CK levels, presented as two-dimensional canonical space. Canonical analysis significantly separated DM1 patients with MIRS III and IV stages from HCs and the other two stages (P < 0.001). DM1 patients were significantly separated from HCs regardless if CK levels were increased (P < 0.001).