No abstract

Imatinib mesylate (IM), a targeted competitive inhibitor of the BCR-ABL tyrosine kinase, has revolutionized the clinical treatment of chronic myeloid leukemia (CML). However, resistance and intolerance are still a challenge in the treatment of CML. Autophagy has been proposed to play a role in IM resistance. To investigate the anti-leukemic activity of specific and potent autophagy inhibitor-1 (spautin-1) in CML, we detected its synergistic effect with IM in K562 and CML cells. Our results showed that spautin-1 markedly inhibited IM-induced autophagy in CML cells by downregulating Beclin-1. Spautin-1 enhanced IM-induced CML cell apoptosis by reducing the expression of the anti-apoptotic proteins Mcl-1 and Bcl-2. We further demonstrated that the pro-apoptotic activity of spautin-1 was associated with activation of GSK3β, an important downstream effector of PI3K/AKT. The findings indicate that the autophagy inhibitor spautin-1 enhances IM-induced apoptosis by inactivating PI3K/AKT and activating downstream GSK3β, leading to downregulation of Mcl-1 and Bcl-2, which represents a promising approach to improve the efficacy of IM in the treatment of patients with CML.

Tuberculous meningitis leads to a devastating outcome, and early diagnosis and rapid chemotherapy are vital to reduce morbidity and mortality. Since Mycobacterium tuberculosis is a kind of cytozoic pathogen and its numbers are very few in cerebrospinal fluid, detecting M. tuberculosis in cerebrospinal fluid from tuberculous meningitis patients is still a challenge for clinicians. Ziehl-Neelsen stain, the current feasible microbiological method for the diagnosis of tuberculosis, often needs a large amount of cerebrospinal fluid specimen but shows a low detection rate of M. tuberculosis. Here, we developed a modified Ziehl-Neelsen stain, involving cytospin slides with Triton processing, in which only 0.5 ml of cerebrospinal fluid specimens was required. This method not only improved the detection rate of extracellular M. tuberculosis significantly but also identified intracellular M. tuberculosis in the neutrophils, monocytes, and lymphocytes clearly. Thus, our modified method is more effective and sensitive than the conventional Ziehl-Neelsen stain, providing clinicians a convenient yet powerful tool for rapidly diagnosing tuberculous meningitis.T uberculous meningitis (TBM) is the most severe form of tuberculosis and causes substantial morbidity and mortality (18). The early diagnosis of and prompt initiation of chemotherapy for TBM are crucial to a successful outcome. However, the early and accurate detection of Mycobacterium tuberculosis in the cerebrospinal fluid (CSF) of TBM patients still remains a challenge for clinicians, mainly due to the lack of rapid, efficient, and practical detection methods (30).Currently, mycobacterial culture is the gold standard for detecting M. tuberculosis, but it is time-consuming and requires specialized safety procedures in laboratories (19,26). Serological methods are convenient but lack sensitivity and specificity (4, 7). Although the PCR technique is rapid, it is costly for routine use in developing countries where most tuberculosis cases occur (5,17,21,24). Conventional smear microscopy with the Ziehl-Neelsen (ZN) stain is a rapid and practical method for detecting acid-fast bacilli (AFB), especially in low-income countries, due to its rapidity, low cost, and high positive predictive value for tuberculosis (14). However, the Ziehl-Neelsen method is severely handicapped by its low detection rate, ranging from 0 to 20% for CSF specimens (31-33). One of the main reasons behind this is that M. tuberculosis can hardly be stained by acid-fast dyes once it enters the cells. Another important reason is that the Ziehl-Neelsen method requires a large volume of CSF for TBM diagnosis, as it is incapable of detecting bacilli that are fewer than 10,000 in number per slide or per ml of specimen (32, 33). Therefore, it is important to develop an alternative, cost-effective method for detecting intracellular M. tuberculosis. Additionally, knowing which cell type is infected by M. tuberculosis in the CSF of TBM patients could help us to unravel new antituberculotic candidates (10).To reve...