title: Pharmacological Inhibition of PKCθ Counteracts Muscle Disease in a Mouse Model of Duchenne Muscular Dystrophy.
abstract: Inflammation plays a considerable role in the progression of Duchenne Muscular Dystrophy (DMD), a severe muscle disease caused by a mutation in the dystrophin gene. We previously showed that genetic ablation of Protein Kinase C θ (PKCθ) in mdx, the mouse model of DMD, improves muscle healing and regeneration, preventing massive inflammation. To establish whether pharmacological targeting of PKCθ in DMD can be proposed as a therapeutic option, in this study we treated young mdx mice with the PKCθ inhibitor Compound 20 (C20). We show that C20 treatment led to a significant reduction in muscle damage associated with reduced immune cells infiltration, reduced inflammatory pathways activation, and maintained muscle regeneration. Importantly, C20 treatment is efficient in recovering muscle performance in mdx mice, by preserving muscle integrity. Together, these results provide proof of principle that pharmacological inhibition of PKCθ in DMD can be considered an attractive strategy to modulate immune response and prevent the progression of the disease.
  
  
  BACKGROUND
  Duchenne muscular dystrophy (DMD) is a severe muscle disease affecting 1:3500 male births. DMD is caused by a mutation in dystrophin gene, coding for a protein required for skeletal and cardiac muscle integrity. Lack of a functional dystrophin is primarily responsible for the muscle eccentric contraction-induced muscle damage, observed in dystrophic muscle. However, inflammation plays a considerable role in the progression of DMD. Glucocorticoids, which have anti-inflammatory properties, are being used to treat DMD with some success; however, long term treatment with these drugs induces muscle atrophy and wasting, outweighing their benefit. The identification of specific targets for anti-inflammatory therapies is one of the ongoing therapeutic options. Although blunting inflammation would not be a "cure" for the disease, the emerging clue is that multiple strategies, addressing different aspects of the pathology, which may eventually converge, may be successful. In this context, we previously showed that genetic ablation of Protein Kinase C θ (PKCθ), an enzyme known to be involved in immune response, in mdx, the mouse model of DMD, improves muscle healing and regeneration, preventing massive inflammation. To establish whether pharmacological targeting of PKCθ in DMD can be proposed as a therapeutic option, in this study we treated young mdx mice with the PKCθ inhibitor Compound 20 (C20). We show that C20 treatment led to a significant reduction in muscle damage associated with reduced immune cells infiltration, reduced inflammatory pathways activation, and maintained muscle regeneration. Importantly, C20 treatment is efficient in recovering muscle performance in mdx mice, by preserving muscle integrity. Together, these results provide proof of principle that pharmacological inhibition of PKCθ in DMD can be considered an attractive strategy to modulate immune response and prevent the progression of the disease.
authors.affiliation: Dept. of Anatomy, Histology, Forensic Medicine and Orthopedics, Unit of Histology and Med. Embryology, CE-BEMM and Interuniversity Institute of Myology, Sapienza University of Rome, 00161 Rome, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Marrocco
authors.affiliation: Dept. of Anatomy, Histology, Forensic Medicine and Orthopedics, Unit of Histology and Med. Embryology, CE-BEMM and Interuniversity Institute of Myology, Sapienza University of Rome, 00161 Rome, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Fiore
authors.affiliation: Dept. of Anatomy, Histology, Forensic Medicine and Orthopedics, Unit of Histology and Med. Embryology, CE-BEMM and Interuniversity Institute of Myology, Sapienza University of Rome, 00161 Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Benedetti
authors.affiliation: Dept. of Anatomy, Histology, Forensic Medicine and Orthopedics, Unit of Histology and Med. Embryology, CE-BEMM and Interuniversity Institute of Myology, Sapienza University of Rome, 00161 Rome, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Pisu
authors.affiliation: Dept. of Anatomy, Histology, Forensic Medicine and Orthopedics, Unit of Histology and Med. Embryology, CE-BEMM and Interuniversity Institute of Myology, Sapienza University of Rome, 00161 Rome, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Rizzuto
authors.affiliation: Dept. of Anatomy, Histology, Forensic Medicine and Orthopedics, Unit of Histology and Med. Embryology, CE-BEMM and Interuniversity Institute of Myology, Sapienza University of Rome, 00161 Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Musarò
authors.affiliation: Dept. of Anatomy, Histology, Forensic Medicine and Orthopedics, Unit of Histology and Med. Embryology, CE-BEMM and Interuniversity Institute of Myology, Sapienza University of Rome, 00161 Rome, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Madaro
authors.affiliation: Dept. of Anatomy, Histology, Forensic Medicine and Orthopedics, Unit of Histology and Med. Embryology, CE-BEMM and Interuniversity Institute of Myology, Sapienza University of Rome, 00161 Rome, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Lozanoska-Ochser
authors.affiliation: Dept. of Anatomy, Histology, Forensic Medicine and Orthopedics, Unit of Histology and Med. Embryology, CE-BEMM and Interuniversity Institute of Myology, Sapienza University of Rome, 00161 Rome, Italy. Electronic address: marina.bouche@uniroma1.it.
authors.forename: M
authors.initials: M
authors.lastname: Bouché
mesh_terms: D000818:Animals; D015153:Blotting, Western; D004151:Dipeptides / Q000494:pharmacology*; D004195:Disease Models, Animal; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007249:Inflammation / Q000235:genetics / Q000378:metabolism / Q000517:prevention & control; D007527:Isoenzymes / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D008297:Male; D008810:Mice, Inbred C57BL; D018101:Mice, Inbred mdx; D018345:Mice, Knockout; D008856:Microscopy, Fluorescence; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D009137:Muscular Dystrophy, Animal / Q000201:enzymology / Q000235:genetics / Q000503:physiopathology*; D020388:Muscular Dystrophy, Duchenne / Q000201:enzymology / Q000235:genetics / Q000503:physiopathology*; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D000074121:Protein Kinase C-theta; D012038:Regeneration / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism
chemical_list: D004151:Dipeptides; D007527:Isoenzymes; D016212:Transforming Growth Factor beta; C028342:compound 20; C489593:Prkcq protein, mouse; D011493:Protein Kinase C; D000074121:Protein Kinase C-theta
keywords: Inflammation; Muscle repair; Muscular dystrophy; Protein Kinase C theta; Therapy