RESUMO
Activin A (Act A) is a member of the TGFß (transforming growth factor ß) superfamily. It communicates via the Suppressor of Mothers against Decapentaplegic Homolog (SMAD2/3) proteins which govern processes such as cell proliferation, wound healing, apoptosis, and metabolism. Act A produces its action by attaching to activin receptor type IIA (ActRIIA) or activin receptor type IIB (ActRIIB). Increasing circulating Act A increases ActRII signalling, which on phosphorylation initiates the ALK4 (activin receptor-like kinase 4) type 1 receptor which further turns on the SMAD pathway and hinders cell functioning. Once triggered, this route leads to gene transcription, differentiation, apoptosis, and extracellular matrix (ECM) formation. Act A also governs the immunological and inflammatory responses of the body, as well as cell death. Moreover, Act A levels have been observed to elevate in several disorders like renal fibrosis, CKD, asthma, NAFLD, cardiovascular diseases, cancer, inflammatory conditions etc. Here, we provide an update on the recent studies relevant to the role of Act A in the modulation of various pathological disorders, giving an overview of the biology of Act A and its signalling pathways, and discuss the possibility of incorporating activin-A targeting as a novel therapeutic approach for the control of various disorders. Pathways such as SMAD signaling, in which SMAD moves to the nucleus by making a complex and leads to tissue fibrosis in CKD, STAT3, which drives renal fibroblast activity and the production of ECM, Kidney injury molecule (KIM-1) in the synthesis, deposition of ECM proteins, SERCA2a (sarcoplasmic reticulum Ca2+ ATPase) in cardiac dysfunction, and NF-κB (Nuclear factor kappa-light-chain-enhancer of activated B cells) in inflammation are involved in Act A signaling, have also been discussed.
Assuntos
Ativinas , Transdução de Sinais , Humanos , Ativinas/metabolismo , Animais , Neoplasias/metabolismo , Neoplasias/imunologia , Neoplasias/tratamento farmacológico , Inflamação/metabolismo , Inflamação/imunologiaRESUMO
Mitochondria are double-membrane organelles that provide the majority of a cell's energy. Furthermore, mitochondria are involved in various cellular biological activities, including calcium signalling, reactive oxygen species production, apoptosis, cell development, and the cell cycle. Mitochondrial dysfunction is seen in various neurological conditions involving acute and chronic neural injury, including neurodegenerative diseases, hypoxia-induced brain injury, and ischemia. This review made a significant contribution to the explanation of the idea that mitochondria would both be critical targets of ischemia-induced processes, including intracellular calcium elevation and reactive oxygen species and essential sites for determining cell viability loss. As a result, it's not unexpected that attempts to prevent I/R damage have focused on mitochondria. Drugs such as vatiquinone, vitexin, dexprmipexole, baicalin, nobiletin, via promoting mitochondrial activities, can be used in future studies for protecting the brain from ischemia injury. This review summarizes mitochondrial pathways, i.e., Bad, Drp-1, JNK/caspase-3, MAPK-ERK, p53, Wnt/ß-Catenin, that contribute to disease progression. We have précised the potential regulatory role of miRNA-mitochondrial dynamics in cerebral ischemic-reperfusion injury and associated molecular mechanisms; also provide insight into the potential therapies for cerebral injury-induced injuries.