Deletion of Mbtps1 (Pcsk8, S1p, Ski-1) Gene in Osteocytes Stimulates Soleus Muscle Regeneration and Increased Size and Contractile Force with Age.
Conditional deletion of Mbtps1 (cKO) protease in bone osteocytes leads to an age-related increase in mass (12%) and in contractile force (30%) in adult slow twitch soleus muscles (SOL) with no effect on fast twitch extensor digitorum longus muscles. Surprisingly, bone from 10-12-month-old cKO animals was indistinguishable from controls in size, density, and morphology except for a 25% increase in stiffness. cKO SOL exhibited increased expression of Pax7, Myog, Myod1, Notch, and Myh3 and 6-fold more centralized nuclei, characteristics of postnatal regenerating muscle, but only in type I myosin heavy chain-expressing cells. Increased expression of gene pathways mediating EGF receptor signaling, circadian exercise, striated muscle contraction, and lipid and carbohydrate oxidative metabolism were also observed in cKO SOL. This muscle phenotype was not observed in 3-month-old mice. Although Mbtps1 mRNA and protein expression was reduced in cKO bone osteocytes, no differences in Mbtps1 or cre recombinase expression were observed in cKO SOL, explaining this age-related phenotype. Understanding bone-muscle cross-talk may provide a fresh and novel approach to prevention and treatment of age-related muscle loss.
['Gorski|Jeff P|JP|', 'Huffman|Nichole T|NT|', 'Vallejo|Julian|J|', 'Brotto|Leticia|L|', 'Chittur|Sridar V|SV|', 'Breggia|Anne|A|', 'Stern|Amber|A|', 'Huang|Jian|J|', 'Mo|Chenglin|C|', 'Seidah|Nabil G|NG|', 'Bonewald|Lynda|L|', 'Brotto|Marco|M|']
D000818:Animals D003433:Crosses, Genetic D004734:Energy Metabolism D020869:Gene Expression Profiling D018507:Gene Expression Regulation, Developmental D008297:Male D018345:Mice, Knockout D009119:Muscle Contraction D024510:Muscle Development D018657:Muscle Fibers, Slow-Twitch D053580:Muscle Strength D018482:Muscle, Skeletal D041641:Musculoskeletal Development D018006:Myogenic Regulatory Factors D010011:Osteocytes D043484:Proprotein Convertases D012333:RNA, Messenger D055948:Sarcopenia D012697:Serine Endopeptidases D014157:Transcription Factors
MBTPS1 osteocyte regeneration bone centralized nuclei cross-talk DMP1 cell signaling gene knock-out skeletal muscle