Effects of electroacupuncture on the PI3K/Akt/CREB signaling pathway and hippocampal neuronal apoptosis in diabetic cognitive impairment rats. / ç”µé’ˆå¯¹ç³–å°¿ç— è®¤çŸ¥åŠŸèƒ½éšœç¢å¤§é¼ PI3K/Akt/CREBä¿¡å·é€šè·¯å’Œæµ·é©¬ç¥žç»å ƒå‡‹äº¡çš„å½±å“.

OBJECTIVES: To observe the effects of electroacupuncture (EA) on the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt)/cAMP response element binding protein (CREB) signaling pathway-related proteins and hippocampal neuron apoptosis in diabetic cognitive impairment (DCI) rats, and to explore the mechanisms of EA in treating DCI. METHODS: Adult male SD rats were randomly divided into normal, model, and EA groups, with 12 rats in each group. The animal model of DCI was replicated using a high-fat, high-sugar diet combined with low-dose streptozotocin. The EA group received EA stimulation at "Yishu" (EX-B6), "Zusanli" (ST36), "Baihui" (GV20), and "Dazhui" (GV14). Blood glucose contents of the rats in each group were measured. The Morris water maze test was used to assess the learning and memory abilities of rats. Transmission electron microscopy was used to observe the ultrastructure of hippocampal CA1 neurons. Nissl staining was used to observe the pathological changes in hippocampal CA1 neurons. TUNEL staining was used to detect the apoptosis in hippocampal CA1 neurons. Western blot was used to detect the protein expression levels of p-PI3K/PI3K and p-Akt/Akt, as well as CREB, p-CREB, cysteine aspartate pro-tease (Caspase)-3, B-cell lymphoma-2 (Bcl-2), and Bcl-2 related X protein (Bax) in the hippocampal tissue of rats. RESULTS: Compared with the normal group, the rats' random blood glucose contents were significantly increased (P<0.01), the escape latency prolonged (P<0.01), and the original platform crossing counts reduced (P<0.01) in the model group. Significant damage to hippocampal CA1 neurons, a significantly increased neuronal apoptosis index (P<0.01), decreased ratio of p-PI3K/PI3K and p-Akt/Akt and expression of CREB, p-CREB and Bcl-2 proteins, increased expression of Caspase-3 and Bax proteins (P<0.01) were observed in the hippocampal tissue of rats in the model group. Compared with the model group, the rats in the EA group showed decreased random blood glucose content (P<0.01), shortened escape latency (P<0.01), increased original platform crossing counts (P<0.01), improved quantity and pathological morphology and ultrastructure of hippocampal CA1 neurons, reduced neuronal apoptosis index (P<0.01), increased ratio of p-PI3K/PI3K and p-Akt/Akt, and expression of CREB, p-CREB and Bcl-2 proteins (P<0.05, P<0.01) in the hippocampal tissue, and decreased expression of Caspase-3 and Bax proteins (P<0.01). CONCLUSIONS: EA can improve the learning and memory abilities of rats with DCI, and the mechanism may be related to the regulation of the expression of PI3K/Akt/CREB signaling pathway-related proteins, which attenuates the neuronal apoptosis in the hippocampus of rats, and improves the neural function.

Integrating Olefin Carboamination and Hofmann-Löffler-Freytag Reaction by Radical Deconstruction of Hydrazonyl N-N Bond.

As a type of elementary organic compounds containing N-N single bond, hydrazone involved chemical conversions are extremely extensive, but they are mainly limited to N2-retention and N2-removal modes. We report herein an unprecedented protocol for the realization of division utilization of the N2-moiety of hydrazone by a radical facilitated N-N bond deconstruction strategy. This new conversion mode enables the successful combination of alkene carboamination and Hofmann-Löffler-Freytag reaction by the reaction of N-homoallyl mesitylenesulfonyl hydrazones with ethyl difluoroiodoacetate under photocatalytic redox neutral conditions. Mechanism studies reveal that the reaction undergoes a radical relay involving addition, crucial remote imino-N migration and H-atom transfer. Consequently, a series of structurally significant ϵ-N-sulphonamide-α,α-difluoro-γ-amino acid esters are efficiently produced via continuous C-C bond and dual C-N bonds forging.

Lactoferrin-Containing Immunocomplexes Drive the Conversion of Human Macrophages from M2- into M1-like Phenotype.

Macrophages are multifunctional cells that perform diverse roles in health and disease and considered the main source of inflammatory cytokines in affected joints of patients with rheumatoid arthritis (RA). M2 macrophages are well known as anti-inflammation and wound-healing cells; however, recent evidence suggests that they can also promote inflammation in RA, although the underlying mechanism remains to be clarified. Based upon our recent finding that lactoferrin (LTF)-containing IgG immunocomplex (LTF-IC), found elevated in RA sera, potent activators of human monocytes/macrophages, we herein demonstrate that LTF-IC was able to elicit immediate proinflammatory cytokine production by M2-polarized human macrophages through coligation with CD14/toll-like receptor (TLR) 4 and FcγRIIa (CD32a). The LTF-IC-treated M2 cells adopted surface maker expression profile similar to that of M1 phenotype and became functionally hyperactive to subsequent stimuli such as lipopolysaccharide, zymosan and IL-1ß, which could provide a positive feedback signal to promote excessive inflammation in RA. They also acquired the ability to facilitate activation of Th17 cells that are known to play critical roles in RA pathology. We propose that IgG ICs containing TLR agonizing autoantigens are able to directly switch human macrophages from M2 into M1-like phenotype, thereby promoting excessive inflammation in autoimmune diseases such as RA.

Expression, purification, and breast cancer cell inhibiting effect of recombinant human lactoferrin C-lobe.

Lactoferrin (LTF), a multifunctional glycoprotein of the transferrin family mainly found in exotic secretions in mammals, is an important defense molecule against not only microbial invasion but also tumors. It folds into two globular domains (N- and C-lobes) each containing an iron-binding site. The cationic antimicrobial peptide in N-lobe is known to exert anti-tumor effect via a non-receptor-mediated pathway. However, whether LTF C-lobe also contributes to its anti-tumor activity remains to be investigated. In this study, a human LTF fragment (amino acid residues 343-682) covering the C-lobe was expressed with a histidine tag in E. coli and the purified polypeptide refolded through a series of buffer changing procedure. The resultant recombinant protein caused significant growth arrest of breast carcinoma cells MDA-MB-231 in a dose- and time-dependent manner, evidently via induction of apoptosis of the cell. Our data suggest a positive role for the C-lobe of human LTF in controlling tumors in vitro.