RESUMO
Klotho, a cellular anti-senescence protein, is related to antitumor actions, growth regulation, proliferation and invasiveness in several types of tumor, including breast cancer. The present study aimed to analyze the serum levels of αKlotho in patients with breast cancer according to histopathological and immunohistochemical variables. A total of 74 patients and 60 healthy controls were recruited. Peripheral blood samples were collected and serum levels were assessed by sandwich ELISA. Clinical and diagnostic data were obtained from medical records and databases of the Clinical Hospital of the Federal University of Uberlândia (Uberlândia, Brazil). The results indicated no difference in the levels of αKlotho between patients and controls (P=0.068); however, the number of patients with breast cancer with undetectable αKlotho was high (n=52). Thus, the variables that were associated with the lowest survival rates were analyzed, relating them to undetectable αKlotho. Among cases of metastatic tumors or tumors with poor differentiation, positive lymph node status and triple-negative status, patients with undetectable αKlotho predominated and had unfavorable overall survival. Due to the significant results obtained in triple-negative patients, an in vitro analysis was performed to determine whether estrogen receptors (ERs) have a role in αKlotho production. Treatment of MCF-7 cells with ER agonists, estradiol (E2) and diarylpropionitrile (DPN), resulted in increases in αKlotho expression and supernatant levels of both agonists, demonstrating a direct association between the ER and Klotho production; of note, the ERß-specific agonist DPN tripled αKlotho expression when compared to E2 (P=0.078). These data suggested that undetectable αKlotho in the serum of patients with breast cancer is related to unfavorable histopathological variables and poor prognosis and ERs possibly have an important role in maintaining adequate quantities of αKlotho.
RESUMO
B cells contribute to the immune system in many ways such as antigen presentation to CD4+ T cells, secretion of cytokines and lymphoid tissue organogenesis. Furthermore, they are the only cell type capable of producing immunoglobulins. B cells also account for critical aspects of the resistance against intracellular pathogens. Trypanosoma cruzi is an intracellular parasite that sabotages humoral response by depletion of immature B cells. Polyclonal activation and secretion of non-specific antibodies are also other mechanisms used by T cruzi to evade and subvert the mammalian host immune system, leading to increased parasitemia and susceptibility to Chagas' disease. It remained unclear whether B cell depletion occurs due to direct contact with T. cruzi or results from a global increase in inflammation. Unlike previous reports, we demonstrated in this study that T. cruzi infects human B cells, resulting in parasite-induced activation of caspase-7 followed by proteolytic cleavage of phospholipase Cγ1 and cell death. These data contribute to explain the mechanisms ruling B-cell depletion and evasion of the immune response by T. cruzi.
Assuntos
Actinas/metabolismo , Linfócitos B/imunologia , Linfócitos B/metabolismo , Caspase 7/metabolismo , Interações Hospedeiro-Patógeno , Fosfolipase C gama/metabolismo , Trypanosoma cruzi/imunologia , Morte Celular , Doença de Chagas/imunologia , Doença de Chagas/metabolismo , Doença de Chagas/parasitologia , Humanos , ProteóliseRESUMO
Classâ 1 myosins (Myo1s) were the first unconventional myosins identified and humans have eight known Myo1 isoforms. The Myo1 family is involved in the regulation of gene expression, cytoskeletal rearrangements, delivery of proteins to the cell surface, cell migration and spreading. Thus, the important role of Myo1s in different biological processes is evident. In this study, we have investigated the effects of pentachloropseudilin (PClP), a reversible and allosteric potent inhibitor of Myo1s, on angiogenesis. We demonstrated that treatment of cells with PClP promoted a decrease in the number of vessels. The observed inhibition of angiogenesis is likely to be related to the inhibition of cell proliferation, migration and adhesion, as well as to alteration of the actin cytoskeleton pattern, as shown on a PClP-treated HUVEC cell line. Moreover, we also demonstrated that PClP treatment partially prevented the delivery of integrins to the plasma membrane. Finally, we showed that PClP caused DNA strand breaks, which are probably repaired during the cell cycle arrest in the G1 phase. Taken together, our results suggest that Myo1s participate directly in the angiogenesis process.
Assuntos
Citoesqueleto de Actina/efeitos dos fármacos , Inibidores da Angiogênese/farmacologia , Ciclo Celular/efeitos dos fármacos , Hidrocarbonetos Clorados/farmacologia , Integrinas/metabolismo , Pirróis/farmacologia , Inibidores da Angiogênese/toxicidade , Adesão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana , Humanos , Hidrocarbonetos Clorados/toxicidade , Integrinas/genética , Miosina Tipo I/metabolismo , Pirróis/toxicidade , RNA Mensageiro/metabolismoRESUMO
OBJECTIVE: The objective of this study was to determine the effect of MTA on the expression of cytokines in mouse pulp tissue. STUDY DESIGN: Pulp tissue was exposed to MTA, and the expression of CCL5/RANTES, CCL2/MCP1, IL-1alpha, IFN-gamma, TNF-alpha, IL-4, and IL-6 was evaluated by RT-PCR at 10 and 20 days after exposure. Control groups were not exposed to MTA. RESULTS: We found no detectable expression of CCL2, IL-4, and IL-6 in the tissue from either group, while TNF-alpha was expressed at high levels 20 days after exposure (P < .05). CCL5 and IL-1alpha mRNA expression was lower in the MTA-treated group 10 days after treatment (P < .05). At 20 days after the surgical procedure, IFN-gamma mRNA expression was also lower in the MTA-treated group (P < .05). CONCLUSIONS: These findings suggest that MTA down-regulates the inflammatory cytokines CCL5, IL-1alpha and IFN-gamma and may have an anti-inflammatory effect.