MiR-34a, a direct target of p53, has been shown to target several molecules associated with the cell cycle and cell survival pathways, and its dysregulation is implicated in cancer drug resistance or sensitivity in several human cancers. However, the correlation between miR-34a expression and chemoresistance has not been explored in HCC. In this study, we confirmed that miR-34a was significantly down-regulated in HCC tissues and HCC cell lines by qRT-PCR. HCC tissues with lower miR-34a expression displayed higher expression of Bcl-2 protein than those with high expression of miR-34a; therefore, an inverse correlation is evident between the miR-34a level and Bcl-2 expression. Moreover, patients with lower miR-34a expression had significantly poorer overall survival. Bioinformatics and luciferase reporter assays revealed that miR-34a binds the 3-UTR of the Bcl-2 mRNA and represses its translation. Western blotting analysis and qRT-PCR confirmed that Bcl-2 is inhibited by miR-34a overexpression. Functional analyses indicated that the restoration of miR-34a reduced cell viability, promoted cell apoptosis and potentiated sorafenib-induced apoptosis and toxicity in HCC cell lines by inhibiting Bcl-2 expression. This study is the first to demonstrate that miR-34a induces sensitivity to the anti-tumor effect of sorafenib in human HCC cells, suggesting a potential role of miR-34a in the treatment of HCC.
New agents with particular specificity toward targeted bacteria and superefficacy in antibacterial activity are urgently needed in facing the crisis of worldwide antibiotic resistance. Herein, a novel strategy by equipping bacteriophage (PAP) with photodynamic inactivation (PDI)active AIEgens (luminogens with aggregation-induced emission property) was presented to generate a type of AIE−PAP bioconjugate with superior capability for both targeted imaging and synergistic killing of certain species of bacteria. The targeting ability inherited from the bacteriophage enabled the bioconjugates to specifically recognize the host bacteria with preserved infection activity of phage itself. Meanwhile, the AIE characteristic empowered them a monitoring functionality, and the realtime tracking of their interactions with targets was therefore realized via convenient fluorescence imaging. More importantly, the PDI-active AIEgens could serve as powerful in situ photosensitizers producing high-efficiency reactive oxygen species (ROS) under white light irradiation. As a result, selective targeting and synergistic killing of both antibiotic-sensitive and multi-drug-resistant (MDR) bacteria were successfully achieved in in vitro and in vivo antibacterial tests with excellent biocompatibility. This novel AIE−phage integrated strategy would diversify the existing pool of antibacterial agents and inspire the development of promising drug candidates in the future.
BackgroundDendritic cells (DCs) release bioactive exosomes that play an important role in immune regulation. Because they express low levels of class I major histocompatibility complex (MHC) and co-stimulatory molecules, exosomes derived from donor immature DCs (imDex) prolong allograft survival by inhibiting T-cell activation. However, this effect is limited and does not induce immunological tolerance when imDex are administered alone. Thus, we tested the effect of combined treatment with donor imDex and low-dose rapamycin on inducing tolerance in a mouse cardiac transplantation model.MethodsImDex were obtained from the culture supernatant of immature DCs derived from donor mouse (C57BL/6) bone marrow and were injected with suboptimal doses of rapamycin into recipient mouse (BALB/c) before and after transplantation. The capacity of this treatment to induce immune tolerance was analyzed in vitro and in vivo using the mouse cardiac transplantation model.ResultsDonor imDex expressed moderate levels of MHC class II and low levels of MHC class I and co-stimulatory molecules, but neither imDex nor subtherapeutic rapamycin dose alone induced cardiac allograft tolerance. Combined treatment with imDex and rapamycin, however, led to donor specific cardiac allograft tolerance. This effect was accompanied by decreased anti-donor antigen cellular response and an increased percentage of spleen CD4+CD25+ T cells in recipients. Furthermore, this donor specific tolerance could be further transferred to naïve allograft recipients through injection of splenocytes, but not serum, from tolerant recipients.ConclusionCombined with immunosuppressive treatment, donor imDex can prolong cardiac allograft survival and induce donor specific allograft tolerance.
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