Blood cell characterization and transcriptome analysis reveal distinct immune response and host resistance of different ploidy cyprinid fish following Aeromonas hydrophila infection.

Aeromonas hydrophila can pose a great threat to survival of freshwater fish. In this study, A. hydrophila infection could decrease blood cell numbers, promote blood cell damage as well as alter the levels of alkaline phosphatase (ALP), lysozyme (LZM), aspartate aminotransferase (AST), total antioxidant capacity (T-AOC), total superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) in immune-related tissues of red crucian carp (RCC, 2 N = 100) and triploid cyprinid fish (3 N fish, 3 N = 150). In addition, the significant alternation of antioxidant status was observed in PBMCs isolated from RCC and 3 N following LPS stimulation. The core differential expression genes (DEGs) involved in apoptosis, immunity, inflammation and cellular signals were co-expressed differentially in RCC and 3 N following A. hydrophila challenge. NOD-like receptor (NLR) signals appeared to play a critical role in A. hydrophila-infected fish. DEGs of NLR signals in RCCah vs RCCctl were enriched in caspase-1-dependent Interleukin-1ß (IL-1ß) secretion, interferon (IFN) signals as well as cytokine activation, while DEGs of NLR signals in 3Nah vs 3Nctl were enriched in caspase-1-dependent IL-1ß secretion and antibacterial autophagy. These results highlighted the differential signal regulation of different ploidy cyprinid fish to cope with bacterial infection.

Application of N-methyl-D-aspartate receptor nanopore in screening ligand molecules.

N-methyl-D-aspartate receptors (NMDARs) are crucial for excitatory synaptic transmission in the central nervous system. To study NMDARs more accurately and conveniently, we developed a stable NMDAR nanopore in a planar lipid bilayer. Pharmacological properties were validated using the allosteric modulator Ro 25-6981 and antagonist D-2-amino-5-phosphonopentanoic acid (D-APV). The cyanotoxin ß-N-methylamino-L-alanine (BMAA) found in fresh water systems is suspected to be associated with the development of neurodegenerative diseases. Therefore, BMAA and its two isomers L-2, 4-Diaminobutyric acid dihydrochloride (DAB) and N-(2-aminoethyl) glycine (AEG) and an endogenous excitotoxin, quinolinic acid (QA), were studied using the NMDAR nanopores to assess their effects on NMDAR modulation. We demonstrated that the NMDAR nanopore could reliably detect its ligand molecules at the single-channel level. The study also demonstrated the practicability of NMDAR nanopores, and results were validated using two-electrode voltage-clamp (TEVC) recording. Compared with TEVC recording, the NMDAR nanopores conducted ion channel gating at the single-channel level without being affected by other proteins on the cell membrane. The highly sensitive and accurate NMDAR nanopore technique thus has a unique advantage in screening NMDAR ligand molecules that could be associated with neurodegenerative disease.

pH Responsiveness of Hexosomes and Cubosomes for Combined Delivery of Brucea javanica Oil and Doxorubicin.

We report pH-responsive liquid crystalline lipid nanoparticles, which are dual-loaded by Brucea javanica oil (BJO) and doxorubicin hydrochloride (DOX) and display a pH-induced inverted hexagonal (pH = 7.4) to cubic (pH = 6.8) to emulsified microemulsion (pH = 5.3) phase transition with a therapeutic application in cancer inhibition. BJO is a traditional herbal medicine that strongly inhibits the proliferation and metastasis of various cancers. Doxorubicin is an antitumor drug, which prevents DNA replication and hampers protein synthesis through intercalation between the base pairs of the DNA helices. Its dose-dependent cardiotoxicity imposes the need for safe delivery carriers. Here, pH-induced changes in the structural and interfacial properties of designed multicomponent drug delivery (monoolein-oleic acid-BJO-DOX) systems are determined by synchrotron small-angle X-ray scattering and the Langmuir film balance technique. The nanocarrier assemblies display good physical stability in the studied pH range and adequate particle sizes and ζ-potentials. Their interaction with model lipid membrane interfaces is enhanced under acidic pH conditions, which mimic the microenvironment around tumor cells. In vitro cytotoxicity and apoptosis studies with BJO-DOX dual-loaded pH-switchable liquid crystalline nanoparticles are performed on the human breast cancer Michigan Cancer Foundation-7 (MCF-7) cell line and MCF-7 cells with doxorubicin resistance (MCF-7/DOX), respectively. The obtained pH-sensitive nanomedicines exhibit enhanced antitumor efficacy. The performed preliminary studies suggest a potential reversal of the resistance of the MCF-7/DOX cells to DOX. These results highlight the necessity for further understanding the link between the established pH-dependent drug release profiles of the nanocarriers and the role of their pH-switchable inverted hexagonal, bicontinuous cubic, and emulsified microemulsion inner organizations for therapeutic outcomes.