Navegando por Palavras-chave "Unfolded protein response"

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    Aerobic exercise training rescues protein quality control disruption on white skeletal muscle induced by chronic kidney disease in rats
    (Wiley, 2018) Moraes, Wilson Max Almeida Monteiro de [UNIFESP]; Souza, Pamella Ramona Moraes de; Paixao, Nathalie Alves de; Sousa, Luis Gustavo Oliveira de; Ribeiro, Daniel Araki [UNIFESP]; Marshall, Andrea G.; Prestes, Jonato; Irigoyen, Maria Claudia; Brum, Patricia Chakur; Medeiros, Alessandra [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    We tested whether aerobic exercise training (AET) would modulate the skeletal muscle protein quality control (PQC) in a model of chronic kidney disease (CKD) in rats. Adult Wistar rats were evaluated in four groups: control (CS) or trained (CE), and 5/6 nephrectomy sedentary (5/6NxS) or trained (5/6NxE). Exercised rats were submitted to treadmill exercise (60 min., five times/wk for 2 months). We evaluated motor performance (tolerance to exercise on the treadmill and rotarod), cross-sectional area (CSA), gene and protein levels related to the unfolded protein response (UPR), protein synthesis/survive and apoptosis signalling, accumulated misfolded proteins, chymotrypsin-like proteasome activity (UPS activity), redox balance and heat-shock protein (HSP) levels in the tibialis anterior. 5/6NxS presented a trend towards to atrophy, with a reduction in motor performance, down-regulation of protein synthesis and up-regulation of apoptosis signalling; increases in UPS activity, misfolded proteins, GRP78, derlin, HSP27 and HSP70 protein levels, ATF4 and GRP78 genes; and increase in oxidative damage compared to CS group. In 5/6NxE, we observed a restoration in exercise tolerance, accumulated misfolded proteins, UPS activity, protein synthesis/apoptosis signalling, derlin, HSPs protein levels as well as increase in ATF4, GRP78 genes and ATF6α protein levels accompanied by a decrease in oxidative damage and increased catalase and glutathione peroxidase activities. The results suggest a disruption of PQC in white muscle fibres of CKD rats previous to the atrophy. AET can rescue this disruption for the UPR, prevent accumulated misfolded proteins and reduce oxidative damage, HSPs protein levels and exercise tolerance.
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    Efeitos do treinamento físico aeróbio sobre a resposta à proteína mal enovelada na musculatura esquelética de ratos submetidos à uremia experimental
    (Universidade Federal de São Paulo (UNIFESP), 2016-07-28) Moraes, Wilson Max Almeida Monteiro de [UNIFESP]; Medeiros, Alessandra [UNIFESP]; http://lattes.cnpq.br/0071198026371230; Universidade Federal de São Paulo (UNIFESP)
    The present study tested whether aerobic exercise training (AET) would modulate the unfolded protein response (UPR) in a model of Chronic Kidney Disease (CKD) in rats. Adult Wistar rats were evaluated in 4 groups: control (CS), control trained (CE), and 5/6 nephrectomy sedentary (5/6NxS) or trained (5/6NxE). Exercised rats were submitted to treadmill exercise for 60 min, 5 times/wk for 2 months. We evaluated motor performance (tolerance to exercise in treadmill and rotarod), cross sectional area (AST), gene and protein levels related to UPR, protein synthesis/survive and apoptosis signaling, accumulated misfolded proteins, chymotripsin-like proteasome activity (UPS activity), redox balance and HSPs protein levels in tibialis anterior. Despite the AST were not different between groups, the 5/6NxS presented a reduction in motor performance followed by down regulation in protein synthesis and up regulation of apoptosis signaling, increased UPS activity, misfolded proteins, GRP78, derlin, HSP27 and HSP70 protein levels and ATF4 and GRP78 genes, increased in oxidative damage compared to CS group. In 5/6NxE, we observed restoration in exercise tolerance, accumulated misfolded proteins, UPS activity, protein synthesis and apoptosis signaling, derlin and HSPs protein levels as well as increased in ATF4 and GRP78 genes and GRP78,ATF6? protein levels accompanied by an decrease in oxidative damage and increased catalase and glutathione-peroxidase activities. These results suggest that an UPR is activated in white muscle fibers of CKD rats, independently of atrophy and that AET amplified this response, but prevented accumulated misfolded proteins, promoting reduction in oxidative damage, HSPs protein levels and exercise tolerance.
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    Papel da família da heat shock protein 70 (HSP70) como alvo terapêutico em mieloma múltiplo através de análises in vitro e in vivo
    (Universidade Federal de São Paulo (UNIFESP), 2017-03-07) Eugênio, Angela Isabel Pereira [UNIFESP]; Colleoni, Gisele Wally Braga [UNIFESP]; http://lattes.cnpq.br/2918635854077904; http://lattes.cnpq.br/1240012495336970; Universidade Federal de São Paulo (UNIFESP)
    Introduction: HSP70 has integrative role in protein degradation due to the interaction with many pathways, such as ubiquitin proteasome, unfolded protein response and autophagy. Objectives: To explore the role of HSP70 as a therapeutic target for multiple myeloma (MM) through in vitro and in vivo analyses. Methods: Bioluminescent cell lines RPMI8226-LUC-PURO and U266-LUC-PURO were treated with HSP70 inhibitor (VER155008) and proteasome inhibitor (bortezomib) for evaluation of apoptosis by flow cytometry. HSP70 members, unfolded protein response and autophagy genes were evaluated by qPCR in the same cell lines. Immunodeficient mice were used for subcutaneous xenograft model in two different approaches: RPMI8226-LUC-PURO cells into the right flank to induce a plasmocytoma. When the tumors became palpable mice were randomised to receive bortezomib, VER155008 or bortezomib plus VER155008 or no intervention. Histologic and protein expression analysis were performed. In a second model, each mouse was inoculated at the same moment, with RPMI8226-LUC-PURO cells into the left and U266-LUC-PURO into the righ flank. Mice were randomised into four groups of treatment and received intravenously proteassome and HSP70 inhitors immediately after xenotransplantation of the cell lines. Bioluminescence (BLI) was measured once a day for seven days. Results: RPMI8226- LUC-PURO and U266-LUC-PURO cell lines express HSP70 family genes, XBP-1 and BECLINA-1. Both cell lines treated with bortezomib, VER155008 (50μM and 80μM), isolated or combined, responded with increased expression of HSPA1A/HSPA1B. RPMI8226-LUC-PURO also showed increased expression of HSPA5 and XBP-1 genes after treatment with VER155008 (50μM). RPMI8226-LUC-PURO almost 60% of late apoptosis after treatment with bortezomib (100nM) alone. Treatment with VER155008, isolated or combined with bortezomib, did not add benefit to bortezomib treatment in 128 this cell line. However, U266-LUC-PURO cell line showed over 60% of cell death after treatment with VER155008 (80μM) alone and also with VER155008 (80μM) plus bortezomib, 48 hours after treatmet. In vivo data showed tumor growth reduction by bioluminescence in the group with RPMI8226-LUC-PURO plasmocytoma after treatment with bortezomib, VER155008 or combination of drugs compared to the control group. Nevertheless, the expression of HSP70 proteins, XBP-1s and BECLINA-1 had no statistically significant changes, except for reduction of XBP-1s protein relative expression in to tumors treated with VER155008. For the group of mice that had no prior induction of tumor, treatment with bortezomib, isolated or combined with VER155008 showed inhibition of tumor growth (or incipient growth) assessed by bioluminescence after one week for both cell lines when compared with the control group. Conclusion: Our study shows that the combination of proteasome and HSP70 inhibitors induced cell death in tumor cells in vitro and in vivo (late apoptosis induction and inhibition of tumor growth). Since HSP70 connects multiple signaling pathways that work synergistically to protect tumor cells from death by proteotoxic stress, it can represent a key role to establish a new approach for the treatment of MM (after achievement of the best response or as maintanence therapy) mostly in patients with deletion of 17p (like U266 cell line).