Title:	Plasticidade do músculo gastrocnêmio após lesão de tendão calcâneo em ratos
Authors:	Mendonça, Victoria Lyssa Assis de
Orientador(es)::	Durigan, Rita de Cássia Marquetti
Assunto::	Expressão gênica Sistema musculoesquelético - doenças Remodelação óssea
Issue Date:	26-Aug-2024
Data de defesa::	18-Dec-2023
Citation:	Plasticidade do músculo gastrocnêmio após lesão de tendão calcâneo em ratos. 2023.. 90 f., il. Dissertação (Mestrado em Ciências da Reabilitação) — Universidade de Brasília, Brasília, 2023.
Abstract:	Introduction: Skeletal muscle is one of the most dynamic tissues in the human body. Among many adaptations, the plasticity of this tissue may be related to its extensive structural and metabolic remodeling. However, there are some gaps in the literature related to the adaptive response of skeletal muscle to tendon injury, including the precise identification of regulatory factors that impact communication between these structures and the dynamic interaction between muscle cells and tissue cells. tendon and inflammatory cells in response to injury. Objective: To analyze the adaptive responses of the gastrocnemius muscle to partial injury of the Achilles tendon (CT) in rats. Methodology: Fifty Wistar rats, approximately 2 months old and with an average weight of 261±15g, were included in the study. The rats were randomly distributed into five groups (n = 10 animals per group): control without partial tendon injury (C), the group observed 3 days after partial tendon injury (3D), the group observed 14 days after partial tendon injury (14D), the group observed 28 days after partial tendon injury (28D) and the group observed 55 days after partial tendon injury (55D). The gastrocnemius muscle after tissue collection was used for gene expression, zymography, flow cytometry, and morphology analyses. Results: A decrease in the expression of Vegf, Smad3, Egr and Aktgenes was observed in the gastrocnemius muscle 3 days after partial CT injury. Likewise, there was an increase in the expression of the genes Col3a1, Ctgf, Timp-2, and Bgn 3 days after the partial lesion of the CT. Within 14 days after partial injury to the Achilles tendon, a decrease in the content of the Mstn and Smad3 genes was observed. On the other hand, there was an increase in the expression levels of the Akt and Vegf genes. In 28 days after the injury, there was an increase in the expression levels of the Tgf-b, Vegf, Mstn, Pax7, and Myod1 genes. With decreased expression of Smad3, Akt. Finally, 55 days after partial injury to the Achilles tendon, the genes Akt, P70s6k, Pax7, Mstn, and Atrogin-1 showed an increase in expression. While the levels of Smad3, Timp-2 showed a decrease compared to the control group. Regarding MMP-2 activity in the gastrocnemius muscle, MMP-2 pro increased in the 28D and 55D groups when compared to the control group. Finally, the 55D group exhibited increased AST and muscle fiber diameter, which was accompanied by upregulation of IL-8 levels. Conclusion: This study examined the impact of partial CT injury on skeletal muscle homeostasis and remodeling in rats. The results suggest that this type of injury can cause adverse effects on signaling and intracellular degradation pathways, disrupting the regulatory mechanisms of the muscle extracellular matrix and communication with the tendon. However, it appears that skeletal muscle can mitigate these detrimental effects compared to injuries that primarily affect the muscle and its impact on the tendon. These results provide valuable information about the mechanisms involved in tendon injuries and can potentially help in the development of more effective therapeutic strategies for recovery from musculotendinous injuries in humans.
metadata.dc.description.unidade:	Faculdade de Ciências e Tecnologias em Saúde (FCTS) – Campus UnB Ceilândia
Description:	Dissertação (mestrado) — Universidade de Brasília, Faculdade de Ceilândia, Programa de Pós-Graduação em Ciências da Reabilitação, 2023.
metadata.dc.description.ppg:	Programa de Pós-Graduação em Ciências da Reabilitação
Agência financiadora:	Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) e Fundação de Apoio à Pesquisa do Distrito Federal (FAPDF).
Appears in Collections:	Teses, dissertações e produtos pós-doutorado

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