Institute of Biochemistry, Albert Szent-Györgyi Faculty of Medicine, University of Szeged, Dóm tér 9, H-6720 Szeged, Hungary.
Biomolecules. 2024 Mar 19;14(3):363. doi: 10.3390/biom14030363.
The low efficiency of in vivo transfection of a few fibres revealed a novel tissue network that temporally amplified growth stimulation in the entire regenerating rat soleus muscle. This acupuncture-like effect was demonstrated when the fibres began to grow after complete fibre degradation, synchronous inflammation, myoblast and myotube formation. Neonatal sarcoplasmic/endoplasmic reticulum ATPase (SERCA1b) was first detected in this system. The neonatal, fast and slow SERCA isoforms displayed consequent changes with innervation and differentiation, recapitulating events in muscle development. In vivo transfection of myotubes with plasmids expressing dominant negative Ras or a calcineurin inhibitor peptide (Cain/cabin) proved that expression of the slow myosin heavy chain and the slow muscle type SERCA2a are differentially regulated. In vivo transfection of a few nuclei of myotubes with dnRas or SERCA1b shRNA stimulated fibre size growth in the whole regenerating muscle but only until the full size had been reached. Growth stimulation by Ras and SERCA1b antisense was abolished by co-transfection of Cain or with perimuscular injection of IL4 antibody. This revealed a novel signalling network resembling scale-free networks which, starting from transfected fibre myonuclei as "hubs", can amplify growth stimulation uniformly in the entire regenerating muscle.
体内少数纤维的转染效率低下揭示了一种新的组织网络，该网络暂时放大了整个再生大鼠比目鱼肌中的生长刺激作用。当纤维在完全降解、同步炎症、成肌细胞和成肌管形成后开始生长时，就表现出了这种类似针灸的效应。在该系统中首次检测到新生儿肌浆/内质网 ATP 酶 (SERCA1b)。新生儿、快速和慢速 SERCA 同工型随着神经支配和分化而发生相应变化，再现了肌肉发育过程中的事件。用表达显性负性 Ras 或钙调神经磷酸酶抑制剂肽 (Cain/cabin) 的质粒对肌管进行体内转染证明，慢肌球蛋白重链和慢肌型 SERCA2a 的表达受到差异调节。用 dnRas 或 SERCA1b shRNA 对少数肌管细胞核进行体内转染可刺激整个再生肌肉中的纤维大小生长，但仅在达到最大纤维大小时才会停止。用 Cain 共转染或用肌周注射 IL4 抗体，可消除 Ras 和 SERCA1b 反义寡核苷酸的生长刺激作用。这揭示了一种类似无标度网络的新型信号网络，该网络从转染纤维的肌核作为“枢纽”开始，可在整个再生肌肉中均匀地放大生长刺激作用。
