Limits...
Reactivation of autophagy by spermidine ameliorates the myopathic defects of collagen VI- mice.

Chrisam M, Pirozzi M, Castagnaro S, Blaauw B, Polishchuck R, Cecconi F, Grumati P, Bonaldo P - Autophagy (2015)

Bottom Line: Autophagy is a self-degradative process responsible for the clearance of damaged or unnecessary cellular components.We have previously found that persistence of dysfunctional organelles due to autophagy failure is a key event in the pathogenesis of COL6/collagen VI-related myopathies, and have demonstrated that reactivation of a proper autophagic flux rescues the muscle defects of Col6a1- (col6a1(-/-)) mice.The beneficial effects of spermidine, together with its being easy to administer and the lack of overt side effects, open the field for the design of novel nutraceutical strategies for the treatment of muscle diseases characterized by autophagy impairment.

View Article: PubMed Central - PubMed

Affiliation: a Department of Molecular Medicine ; University of Padova ; Padova , Italy.

ABSTRACT
Autophagy is a self-degradative process responsible for the clearance of damaged or unnecessary cellular components. We have previously found that persistence of dysfunctional organelles due to autophagy failure is a key event in the pathogenesis of COL6/collagen VI-related myopathies, and have demonstrated that reactivation of a proper autophagic flux rescues the muscle defects of Col6a1- (col6a1(-/-)) mice. Here we show that treatment with spermidine, a naturally occurring nontoxic autophagy inducer, is beneficial for col6a1(-/-) mice. Systemic administration of spermidine in col6a1(-/-) mice reactivated autophagy in a dose-dependent manner, leading to a concurrent amelioration of the histological and ultrastructural muscle defects. The beneficial effects of spermidine, together with its being easy to administer and the lack of overt side effects, open the field for the design of novel nutraceutical strategies for the treatment of muscle diseases characterized by autophagy impairment.

No MeSH data available.


Related in: MedlinePlus

Spermidine treatment ameliorates the myopathic phenotype of col6a1−/− mice. (A, B) Haematoxylin-eosin staining of cross sections of tibialis anterior muscles from untreated (Ctrl) and per os (A) or i.p. (B) spermidine-treated wild-type and col6a1−/− mice. In col6a1−/− mice, centrally nucleated fibers (black arrowheads) and atrophic fibers (white arrowheads) appear reduced after spermidine treatment. Scale bar: 50 μm. (C) Representative electron micrographs of diaphragm thin sections from untreated (a to c) and per os (d to f) or i.p. (g to i) spermidine-treated col6a1−/− mice. Low-power views (upper panels) reveal improvement of muscle ultrastructure following spermidine treatment. High-power magnifications (lower panels) show dilated sarcoplasmic reticulum (SR) and swollen mitochondria (mit) in untreated col6a1−/− mice (b,c), and the presence of autophagic vacuoles (AV) in spermidine-treated col6a1−/− mice (f,i) together with a marked amelioration of organelle morphology (e,h). Scale bar: 1 μm (upper panels) or 500 nm (lower panels). (D) Percentage of morphologically altered mitochondria in the diaphragm of untreated (Ctrl) and spermidine-treated (PO 30, per os 30 mM; IP 50, i.p. 50 mg/kg) col6a1−/− mice (n = 3 or 4; P< 0.05; NS, not significant.) (E) Quantification of apoptosis by TUNEL assay in diaphragm muscles of untreated (Ctrl) and per os (left panel) or i.p. (right panel) spermidine-treated wild-type and col6a1−/− mice (n = 3, each group; **, P < 0.01; ***, P < 0.001). (F) In vivo tetanic force measurements in gastrocnemius muscle of untreated (Ctrl) and per os or i.p. spermidine-treated wild-type and col6a1−/− mice. The histograms report the normalized strength at a stimulation frequency of 100 Hz (n = 5, each group; ***, P<0.001; NS, not significant). Ctrl, untreated control condition; Spd IP, spermidine i.p.; Spd PO, spermidine per os. WT, wild-type.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4835186&req=5

f0002: Spermidine treatment ameliorates the myopathic phenotype of col6a1−/− mice. (A, B) Haematoxylin-eosin staining of cross sections of tibialis anterior muscles from untreated (Ctrl) and per os (A) or i.p. (B) spermidine-treated wild-type and col6a1−/− mice. In col6a1−/− mice, centrally nucleated fibers (black arrowheads) and atrophic fibers (white arrowheads) appear reduced after spermidine treatment. Scale bar: 50 μm. (C) Representative electron micrographs of diaphragm thin sections from untreated (a to c) and per os (d to f) or i.p. (g to i) spermidine-treated col6a1−/− mice. Low-power views (upper panels) reveal improvement of muscle ultrastructure following spermidine treatment. High-power magnifications (lower panels) show dilated sarcoplasmic reticulum (SR) and swollen mitochondria (mit) in untreated col6a1−/− mice (b,c), and the presence of autophagic vacuoles (AV) in spermidine-treated col6a1−/− mice (f,i) together with a marked amelioration of organelle morphology (e,h). Scale bar: 1 μm (upper panels) or 500 nm (lower panels). (D) Percentage of morphologically altered mitochondria in the diaphragm of untreated (Ctrl) and spermidine-treated (PO 30, per os 30 mM; IP 50, i.p. 50 mg/kg) col6a1−/− mice (n = 3 or 4; P< 0.05; NS, not significant.) (E) Quantification of apoptosis by TUNEL assay in diaphragm muscles of untreated (Ctrl) and per os (left panel) or i.p. (right panel) spermidine-treated wild-type and col6a1−/− mice (n = 3, each group; **, P < 0.01; ***, P < 0.001). (F) In vivo tetanic force measurements in gastrocnemius muscle of untreated (Ctrl) and per os or i.p. spermidine-treated wild-type and col6a1−/− mice. The histograms report the normalized strength at a stimulation frequency of 100 Hz (n = 5, each group; ***, P<0.001; NS, not significant). Ctrl, untreated control condition; Spd IP, spermidine i.p.; Spd PO, spermidine per os. WT, wild-type.

Mentions: To assess whether spermidine administration has any effect on the structural defects of COL6-deficient myopathic mice, we performed histological analysis of tibialis anterior muscles from wild-type and col6a1−/− mice subjected to the different protocols of spermidine treatment. In wild-type mice, treatment with spermidine did not cause any sign of histological changes in muscle architecture at the tested doses and routes of administration (Fig. 2A and B). As expected,16 under untreated conditions col6a1−/− tibialis anterior displayed an overt myopathic phenotype, with centrally nucleated myofibers, small atrophic fibers and giant hypertrophic ones. Notably, both i.p. and per os spermidine treatments led to a noticeable amelioration of the myopathic defects. The effects of spermidine seemed to correlate with the dose, as col6a1−/− mice treated with the high doses displayed improved muscle histology (Fig. 2A and B). Indeed, 3 mM per os and 5 mg/kg i.p. spermidine treatments led to a partial rescue of histological alterations in col6a1−/− mice and, albeit less extended, the myopathic defects were still present, with some atrophic and degenerating myofibers (Fig. 2A and B). However, col6a1−/− animals displayed markedly improved muscle morphology both after 30 mM per os and 50 mg/kg i.p. spermidine treatment, with barely detectable signs of myofiber degeneration, more homogeneous myofiber size and rare atrophic fibers (Fig. 2A and B). Some centrally nucleated fibers were present in treated animals, consistent with myofiber regeneration (Fig. 2A and B).Figure 2 (see previous page).


Reactivation of autophagy by spermidine ameliorates the myopathic defects of collagen VI- mice.

Chrisam M, Pirozzi M, Castagnaro S, Blaauw B, Polishchuck R, Cecconi F, Grumati P, Bonaldo P - Autophagy (2015)

Spermidine treatment ameliorates the myopathic phenotype of col6a1−/− mice. (A, B) Haematoxylin-eosin staining of cross sections of tibialis anterior muscles from untreated (Ctrl) and per os (A) or i.p. (B) spermidine-treated wild-type and col6a1−/− mice. In col6a1−/− mice, centrally nucleated fibers (black arrowheads) and atrophic fibers (white arrowheads) appear reduced after spermidine treatment. Scale bar: 50 μm. (C) Representative electron micrographs of diaphragm thin sections from untreated (a to c) and per os (d to f) or i.p. (g to i) spermidine-treated col6a1−/− mice. Low-power views (upper panels) reveal improvement of muscle ultrastructure following spermidine treatment. High-power magnifications (lower panels) show dilated sarcoplasmic reticulum (SR) and swollen mitochondria (mit) in untreated col6a1−/− mice (b,c), and the presence of autophagic vacuoles (AV) in spermidine-treated col6a1−/− mice (f,i) together with a marked amelioration of organelle morphology (e,h). Scale bar: 1 μm (upper panels) or 500 nm (lower panels). (D) Percentage of morphologically altered mitochondria in the diaphragm of untreated (Ctrl) and spermidine-treated (PO 30, per os 30 mM; IP 50, i.p. 50 mg/kg) col6a1−/− mice (n = 3 or 4; P< 0.05; NS, not significant.) (E) Quantification of apoptosis by TUNEL assay in diaphragm muscles of untreated (Ctrl) and per os (left panel) or i.p. (right panel) spermidine-treated wild-type and col6a1−/− mice (n = 3, each group; **, P < 0.01; ***, P < 0.001). (F) In vivo tetanic force measurements in gastrocnemius muscle of untreated (Ctrl) and per os or i.p. spermidine-treated wild-type and col6a1−/− mice. The histograms report the normalized strength at a stimulation frequency of 100 Hz (n = 5, each group; ***, P<0.001; NS, not significant). Ctrl, untreated control condition; Spd IP, spermidine i.p.; Spd PO, spermidine per os. WT, wild-type.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835186&req=5

f0002: Spermidine treatment ameliorates the myopathic phenotype of col6a1−/− mice. (A, B) Haematoxylin-eosin staining of cross sections of tibialis anterior muscles from untreated (Ctrl) and per os (A) or i.p. (B) spermidine-treated wild-type and col6a1−/− mice. In col6a1−/− mice, centrally nucleated fibers (black arrowheads) and atrophic fibers (white arrowheads) appear reduced after spermidine treatment. Scale bar: 50 μm. (C) Representative electron micrographs of diaphragm thin sections from untreated (a to c) and per os (d to f) or i.p. (g to i) spermidine-treated col6a1−/− mice. Low-power views (upper panels) reveal improvement of muscle ultrastructure following spermidine treatment. High-power magnifications (lower panels) show dilated sarcoplasmic reticulum (SR) and swollen mitochondria (mit) in untreated col6a1−/− mice (b,c), and the presence of autophagic vacuoles (AV) in spermidine-treated col6a1−/− mice (f,i) together with a marked amelioration of organelle morphology (e,h). Scale bar: 1 μm (upper panels) or 500 nm (lower panels). (D) Percentage of morphologically altered mitochondria in the diaphragm of untreated (Ctrl) and spermidine-treated (PO 30, per os 30 mM; IP 50, i.p. 50 mg/kg) col6a1−/− mice (n = 3 or 4; P< 0.05; NS, not significant.) (E) Quantification of apoptosis by TUNEL assay in diaphragm muscles of untreated (Ctrl) and per os (left panel) or i.p. (right panel) spermidine-treated wild-type and col6a1−/− mice (n = 3, each group; **, P < 0.01; ***, P < 0.001). (F) In vivo tetanic force measurements in gastrocnemius muscle of untreated (Ctrl) and per os or i.p. spermidine-treated wild-type and col6a1−/− mice. The histograms report the normalized strength at a stimulation frequency of 100 Hz (n = 5, each group; ***, P<0.001; NS, not significant). Ctrl, untreated control condition; Spd IP, spermidine i.p.; Spd PO, spermidine per os. WT, wild-type.
Mentions: To assess whether spermidine administration has any effect on the structural defects of COL6-deficient myopathic mice, we performed histological analysis of tibialis anterior muscles from wild-type and col6a1−/− mice subjected to the different protocols of spermidine treatment. In wild-type mice, treatment with spermidine did not cause any sign of histological changes in muscle architecture at the tested doses and routes of administration (Fig. 2A and B). As expected,16 under untreated conditions col6a1−/− tibialis anterior displayed an overt myopathic phenotype, with centrally nucleated myofibers, small atrophic fibers and giant hypertrophic ones. Notably, both i.p. and per os spermidine treatments led to a noticeable amelioration of the myopathic defects. The effects of spermidine seemed to correlate with the dose, as col6a1−/− mice treated with the high doses displayed improved muscle histology (Fig. 2A and B). Indeed, 3 mM per os and 5 mg/kg i.p. spermidine treatments led to a partial rescue of histological alterations in col6a1−/− mice and, albeit less extended, the myopathic defects were still present, with some atrophic and degenerating myofibers (Fig. 2A and B). However, col6a1−/− animals displayed markedly improved muscle morphology both after 30 mM per os and 50 mg/kg i.p. spermidine treatment, with barely detectable signs of myofiber degeneration, more homogeneous myofiber size and rare atrophic fibers (Fig. 2A and B). Some centrally nucleated fibers were present in treated animals, consistent with myofiber regeneration (Fig. 2A and B).Figure 2 (see previous page).

Bottom Line: Autophagy is a self-degradative process responsible for the clearance of damaged or unnecessary cellular components.We have previously found that persistence of dysfunctional organelles due to autophagy failure is a key event in the pathogenesis of COL6/collagen VI-related myopathies, and have demonstrated that reactivation of a proper autophagic flux rescues the muscle defects of Col6a1- (col6a1(-/-)) mice.The beneficial effects of spermidine, together with its being easy to administer and the lack of overt side effects, open the field for the design of novel nutraceutical strategies for the treatment of muscle diseases characterized by autophagy impairment.

View Article: PubMed Central - PubMed

Affiliation: a Department of Molecular Medicine ; University of Padova ; Padova , Italy.

ABSTRACT
Autophagy is a self-degradative process responsible for the clearance of damaged or unnecessary cellular components. We have previously found that persistence of dysfunctional organelles due to autophagy failure is a key event in the pathogenesis of COL6/collagen VI-related myopathies, and have demonstrated that reactivation of a proper autophagic flux rescues the muscle defects of Col6a1- (col6a1(-/-)) mice. Here we show that treatment with spermidine, a naturally occurring nontoxic autophagy inducer, is beneficial for col6a1(-/-) mice. Systemic administration of spermidine in col6a1(-/-) mice reactivated autophagy in a dose-dependent manner, leading to a concurrent amelioration of the histological and ultrastructural muscle defects. The beneficial effects of spermidine, together with its being easy to administer and the lack of overt side effects, open the field for the design of novel nutraceutical strategies for the treatment of muscle diseases characterized by autophagy impairment.

No MeSH data available.


Related in: MedlinePlus