HISTOLOGY AND HISTOPATHOLOGY

From Cell Biology to Tissue Engineering

 

Histology of skeletal muscle reconstructed by means of the implantation of autologous adipose tissue: an experimental study

Fernando Leiva-Cepas1,2,3*, Ignacio Jimena1,2,3, Ignacio Ruz-Caracuel1,2#, Evelio Luque1,3, Rafael Villalba4 and Jose Peña-Amaro1,2,3

1Department of Morphological Sciences, Section of Histology, Faculty of Medicine and Nursing, 2Research Group in Muscle Regeneration, 3Maimonides Institute for Biomedical Research IMIBIC, Reina Sofia University Hospital, University of Cordoba and 4Tissue of Establishment of the Center for Transfusion, Tissues and Cells, Cordoba, Spain
Present address: *Department of Pathology, Reina Sofia University Hospital, Cordoba, #Department of Pathology, Ramón y Cajal University Hospital, Madrid, Spain

Offprint requests to: Jose Peña, Departamento de Ciencias Morfológicas (Seccion de Histología), Facultad de Medicina y Enfermería, Universidad de Córdoba, Cordoba, Spain. e-mail: cm1peamj@uco.es


Summary. The purpose of this study was to determine the histological characteristics of a skeletal muscle reconstructed by means of the implantation of autologous adipose tissue following an experimentally-induced volumetric muscle loss. A cylindrical piece in the belly of the rat anterior tibial muscle was removed. In the hole, inguinal subcutaneous adipose tissue of the same rat was grafted. Animals were sacrificed 7, 14, 21, 28 and 60 days posttransplantation. Histological, histochemical, immunohistochemical and morphometric techniques were used. At all times analyzed, the regenerative muscle fibers formed from the edges of the muscle tissue showed histological, histochemical and immunohistochemical differences in comparison with the control group. These differences are related to delays in the maturation process and are related to problems in reinnervation and disorientation of muscle fibers. The stains for MyoD and desmin showed that some myoblasts and myotubes seem to derive from the transplanted adipose tissue. After 60 days, the transplant area was 20% occupied by fibrosis and by 80% skeletal muscle. However, the neo-muscle was chaotically organized showing muscle fiber disorientation and centronucleated fibers with irregular shape and size. Our results support the hypothesis that, at least from a morphological point of view, autologous adipose tissue transplantation favors reconstruction following a volumetric loss of skeletal muscle by combining the inherent regenerative response of the organ itself and the myogenic differentiation of the stem cells present in the adipose tissue. However, in our study, the formed neo-muscle exhibited histological differences in comparison with the normal skeletal muscle. Histol Histopathol 35, 457-474 (2020)

Key words: Skeletal muscle, Muscle regeneration, Adipose tissue, Graft, Fibrosis

DOI: 10.14670/HH-18-163