ß-Hydroxybutyrate alleviates brain aging through the MTA1 pathway in D-galactose injured mice.

Aging is an inevitable law of the process of life during which many physiological functions change. Brain aging is an important mechanism in the occurrence and development of degenerative diseases of the central nervous system. ß-Hydroxybutyrate (BHBA) is a water-soluble, endogenous small-molecule ketone that can cross the blood-brain barrier and induce neuroprotective effects. This study aimed to investigate the effects of BHBA on D-galactose (D-gal) induced aging in mice and its underlying mechanisms using in vitro and in vivo experiments. These results indicated that D-gal-induced senescence, oxidative stress, and inflammatory responses were inhibited by BHBA, and autophagy was promoted by BHBA. Mechanistically, we explored the role of metastasis-associated antigen-1 (MTA1) in D-gal-induced damaged in HT22 cells using small interfering RNA (siRNA). The results demonstrated that the expression of MTA1 was significantly increased by BHBA, which attenuated D-gal-induced aging, oxidative stress, and inflammatory responses, and promoted autophagy through the upregulation of MTA1. In conclusion, MTA1 may be a novel target for treating aging caused by neurological damage. BHBA improves brain aging by activating the MTA1 pathway.

ß-hydroxybutyrate Alleviates Learning and Memory Impairment Through the SIRT1 Pathway in D-Galactose-Injured Mice.

Learning and memory impairment is a common clinical symptom of aging and nervous system injuries, and seriously affects quality of life. Memory impairment is associated with increased oxidative stress (OS) and inflammatory response. ß-hydroxybutyrate (BHBA) is a water-soluble endogenous small-molecule ketone body that easily crosses the blood-brain barrier and has shown neuroprotection activities. In this study, we investigated the effects and mechanisms of BHBA on D-galactose (D-gal)-induced memory impairment in mice by in vitro and in vivo experiments. BHBA was administered intragastrically to D-gal-injured C57BL/6 mice for 42 days. Water maze performance, the morphology of the hippocampus with Nissl staining, the ACh content, OS, and inflammation status were examined. To further investigate the mechanism, hippocampal neuronal cells (HT22) were treated with BHBA with or without the SIRT1 inhibitor or small interfering RNAs against sirt1 (si-SIRT1) before incubation with D-gal. BHBA significantly improved water maze performance; increased the ACh content, SOD activity, and SIRT1 expression; and decreased AChE and LDH activity, ROS, MDA, IL-1ß, TNF-α contents, and NLRP3 expression. Further studies with the SIRT inhibitor or siRNAs against sirt1 reversed the above effects of BHBA. Collectively, BHBA inhibited hippocampal OS and the inflammation process to alleviate learning and memory impairment through activating the SIRT1 pathway in D-gal-injured mice, suggesting that BHBA could be a potential option for drug development of learning and memory impairment induced by nervous system injuries.

Simultaneous electrochemical detection of levodapa, paracetamol and l-tyrosine based on multi-walled carbon nanotubes.

Herein multi-walled carbon nanotubes (MWCNTs) were processed by ultrasonication and freeze-drying method. The morphology of the processed MWCNTs was examined by scanning electron microscopy. An original electrochemical sensor for the simultaneous detection of levodapa (LD), paracetamol (PA) and l-tyrosine (Tyr) was developed by dropcasting a mixture of processed MWCNTs and Nafion on a glassy carbon electrode. The as-prepared sensor was studied by cyclic voltammetry and differential pulse voltammetry. The peak currents of LD, PA and Tyr significantly increased compared to those obtained at bare glassy carbon electrodes or unprocessed MWCNTs modified electrodes. The peaks of LD, PA and Tyr were well-defined and obviously separated from each other. The linear ranges for detection of LD, PA and Tyr were 2.0-300.0, 2.0-180.0, and 2.0-120.0 µM, with a detection limit of 0.6, 0.5 and 0.8 µM (S/N = 3), respectively. Finally, the sensor was applied to detect LD, PA and Tyr in serum samples, and the results were satisfactory.

Pristimerin inhibits glioma progression by targeting AGO2 and PTPN1 expression via miR-542-5p.

Glioblastoma multiform is the most common and malignant primary tumor of the central nervous system in adults, the high recurrence rate and poor prognosis are critical priorities. Pristimerin is a naturally occurring quinone methide triterpenoid isolated from the Celastraceae and Hippocrateaceae families. Its anticancer effects have garnered considerable attention; nonetheless, the mechanisms of action remain unknown. To predict the hub genes of pristimerin, PharmMapper and the Coremine database were used to identify 13 potential protein targets; protein-protein interaction, for which functional enrichment analyses were performed. Compound-target, target-pathway, and compound-target-pathway networks were constructed using Cytoscape. Biological process analysis first revealed that enrichment of these target genes correlated with negative regulation of symbiont growth in the host, and regulation of chronic inflammatory response to antigenic stimulus. Survival analysis in cBioPortal showed that protein tyrosine phosphatase, non-receptor type 1 (PTPN1) and Argonaute 2 (AGO2) might be involved in the carcinogenesis, invasion, or recurrence of diffuse glioma. In addition, we observed that low-dose pristimerin inhibited the viability of glioma cells, while miR-542-5p in vitro; and reduced PTPN1 expression. Notably, high-dose pristimerin induced apoptosis. Furthermore, miR-542-5p silence with siRNA in glioma cells lead to the elevation in AGO2, and decreased PTPN1 level. The effect was obviously post pristimerin treatment and miR-542-5p suppression. In conclusion, pristimerin inhibited glioma progression through AGO2 and PTPN1 expression via a canonical miRNA-mediated mechanism.

Positive selection vector using the KillerRed gene.

Plasmid pZK18S is a novel positive selection vector containing the genetically encoded photosensitizer KillerRed as the selection marker. When transformed into host cells (lacI(q) or lacI(+)), the common medical surgical light is sufficient to activate phototoxicity of KillerRed. Thus, only the recombinants with disrupted reading frame of KillerRed genes finally allow forming viable colonies. Because lethality of KillerRed relies on light irradiation, no special host and culture medium are required to amplify and prepare pZK18S vector in larger quantities. The pZK18S was reliable and highly efficient for constructing the serial analysis of gene expression (SAGE) library.

T vector bearing KillerRed protein marker for red/white cloning screening.

As a novel selection marker for DNA cloning, the genetically encoded photosensitizer KillerRed was used to achieve red/white cloning screening within the pZK18T T-vector system. KillerRed functioned without cofactors, inducers, or substrates. KillerRed-based red/white cloning screening was reliable in that bacteria containing DNA inserts that disrupt functional KillerRed expression form white colonies or red colonies as backgrounds. KillerRed simplifies assembly of customized vector and recombinant screening procedures. No special host or culture medium is required to amplify and prepare the vector in larger quantities. It makes high-throughput general-purpose cloning screening simpler, less expensive, and more effective.

3G vector-primer plasmid for constructing full-length-enriched cDNA libraries.

We designed a 3G vector-primer plasmid for the generation of full-length-enriched complementary DNA (cDNA) libraries. By employing the terminal transferase activity of reverse transcriptase and the modified strand replacement method, this plasmid (assembled with a polydT end and a deoxyguanosine [dG] end) combines priming full-length cDNA strand synthesis and directional cDNA cloning. As a result, the number of steps involved in cDNA library preparation is decreased while simplifying downstream gene manipulation, sequencing, and subcloning. The 3G vector-primer plasmid method yields fully represented plasmid primed libraries that are equivalent to those made by the SMART (switching mechanism at 5' end of RNA transcript) approach.