Dan Liu,Ruizhuo Lin,Huifang Wu,Jiahui Ji,Donghan Wang,Zhiyuan Xue,Shilan Feng,Xinyue Chen
Grape seed procyanidin extract was used to green synthesize AuNPs (OPC-AuNPs), in which procyanidin (OPC) accounted for 95% of total content. To improve the dispersion and uniformity of particle size, various conditions were optimized. The final OPC-AuNPs showed excellent stability and were characterized by a series of techniques. Owing to the good quenching properties of OPC-AuNPs, the fluorescence system of OPC-AuNPs and Rhodamine B (RB) mixture was established for prazosin testing. OPC-AuNPs could effectively quench fluorescence based on fluorescence resonance energy transfer (FRET). When prazosin and the testing system of OPC-AuNPs and RB mixture coexisted in the solution, prazosin would replace RB and competitively bond on the surface of OPC-AuNPs, thus RB was dissociated from OPC-AuNPs, resulting in the rapid recovery of fluorescence. This article provided a green, simple one-pot synthesis method for OPC-AuNPs and established a fast, sensitive, visible fluorescence system for prazosin detection which was successfully applied in real sample detection.
Lu Yang,Zijin Lin,Ruijing Mu,Wenhan Wu,Hao Zhi,Xiaodong Liu,Hanyu Yang,Li Liu
Blood–brain barrier (BBB) prevents neurotoxins from entering central nervous system. We aimed to establish and characterize an in vitro triple co-culture BBB model consisting of brain endothelial cells hCMEC/D3, astrocytoma U251 cells, and neuroblastoma SH-SY5Y cells. Co-culture of SH-SY5Y and U251 cells markedly enhanced claudin-5 and VE-cadherin expression in hCMEC/D3 cells, accompanied by increased transendothelial electrical resistance and decreased permeability. Conditioned medium (CM) from SH-SY5Y cells (S-CM), U251 cells (U-CM), and co-culture of SH-SY5Y and U251 cells (US-CM) also promoted claudin-5 and VE-cadherin expression. Glial cell line-derived neurotrophic factor (GDNF) levels in S-CM and US-CM were significantly higher than CMs from hCMEC/D3 and U-CM. Both GDNF and US-CM upregulated claudin-5 and VE-cadherin expression, which were attenuated by anti-GDNF antibody and GDNF signaling inhibitors. GDNF increased claudin-5 expression via the PI3K/AKT/FOXO1 and MAPK/ERK pathways. Meanwhile, GDNF promoted VE-cadherin expression by activating PI3K/AKT/ETS1 and MAPK/ERK/ETS1 signaling. The roles of GDNF in BBB integrity were validated using brain-specific Gdnf silencing mice. The developed triple co-culture BBB model was successfully applied to predict BBB permeability. In conclusion, neurons enhance BBB integrity by upregulating claudin-5 and VE-cadherin expression through GDNF secretion and established triple co-culture BBB model may be used to predict drugs’ BBB permeability.
Prazosin (Prz), an antagonist of alpha-1 adrenergic receptors, is conventionally employed in the treatment of hypertension. Our study pioneers the exploration of Prz in oncology, examining its impact on cellular autophagy and its potential to trigger antitumor immune responses. We have developed a novel Prz-loaded liposome hybrid nanovesicle (Prz@LINV) system, integrating tumor-derived nanovesicles (TNV) with liposomes (LIP) to facilitate targeted Prz delivery to tumor sites. This formulation enhances Prz bioavailability and markedly inhibits tumor cell autophagy, leading to immunogenic cell death (ICD) and the activation of antitumor immune responses. Furthermore, Prz@LINV modulates dendritic cells (DCs), augmenting their antigen cross-presentation capacity and thereby potentiating antitumor immunity. These effects were validated in a colorectal cancer mouse model, demonstrating the good biocompatibility of Prz@LINV and its significant inhibition in tumor growth, along with the enhancement of antitumor immune responses. Our findings elucidate a novel mechanism by which Prz inhibits autophagy and enhances the antitumor immune response, providing a foundation for the development of innovative immunotherapeutic strategies. The efficacy of Prz@LINV suggests that Prz may emerge as a pivotal component in future immunotherapeutic regimens, offering patients more potent therapeutic options.
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