Optimization of machine learning classification models for tumor cells based on cell elements heterogeneity with laser-induced breakdown spectroscopy.

The rapid and accurate diagnosis of cancer is an important topic in clinical medicine. In the present work, an innovative method based on laser-induced breakdown spectroscopy (LIBS) combined with machine learning was developed to distinguish and classify different tumor cell lines. The LIBS spectra of cells were first acquired. Then the spectral pre-processing was performed as well as detailed optimization to improve the classification accuracy. After that, the convolutional neural network (CNN), support vector machine (SVM), and K-nearest neighbors were further compared for the optimized classification ability of tumor cells. Both the CNN algorithm and SVM algorithm have achieved impressive discrimination performances for tumor cells distinguishing, with an accuracy of 97.72%. The results show that the heterogeneity of elements in tumor cells plays an important role in distinguishing the cells. It also means that the LIBS technique can be used as a fast classification method for classifying tumor cells.

Dynorphin/KOR inhibits neuronal autophagy by activating mTOR signaling pathway to prevent acute seizure epilepsy.

In previous studies, we found that dynorphin exerts antiepileptic effect by activating the kappa opioid receptor (KOR). However, the role of neuronal autophagy in dynorphin/KOR-mediated antiepileptic is still unclear. This study aimed to investigate the molecular mechanism of dynorphin's antiepileptic effect by inhibiting autophagy and reducing neuronal apoptosis. Here, a pilocarpine-induced rat model of epilepsy was established and hippocampal neurons were treated with Mg2+ -free exposed for epileptiform activity induction. The real-time polymerase chain reaction and Western blot analysis were used to evaluate messenger RNA and protein expression. The TdT-mediated dUTP-biotin nick end labeling staining and flow cytometry were used to analyze cell apoptosis in vivo and in vitro. Neuron cells viability was detected by Cell Counting Kit-8 assay. Immunofluorescent staining and green fluorescent protein-light chain 3 immunofluorescence were used to measure autophagy in vivo and in vitro. Results showed that overexpression of prodynorphin alleviated neuronal apoptosis, activated the mammalian target of rapamycin (mTOR) signaling pathway, and inhibited neuronal autophagy in epileptic rats. Dynorphin inhibited Mg2+ -free-induced seizure-like neuron apoptosis, partially reversing the effect of Mg2+ -free on the mTOR signaling pathway and seizure-like neuron autophagy. Further, using rapamycin, we found that dynorphin inhibited Mg2+ -free-induced seizure-like neuron autophagy and apoptosis by activating the mTOR signaling pathway. In conclusion, dynorphin inhibits autophagy by activating the mTOR signaling pathway and has a protective effect on epilepsy acute seizure and epilepsy-induced brain injury.

Dynorphin activation of kappa opioid receptor promotes microglial polarization toward M2 phenotype via TLR4/NF-κB pathway.

BACKGROUND: Microglia-mediated neuroinflammation is associated with epilepsy. Switching microglial polarization from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype represents a novel therapeutic strategy for mitigating epileptogenesis. We previously found that dynorphins protected against epilepsy via activation of kappa opioid receptor (KOR). Here, this study aims to investigate the role and the mechanism of dynorphin in regulating microglial polarization. METHODS: A pilocarpine-induced rat model of epilepsy was established and lipopolysaccharide (LPS)-activated BV-2 microglial cells were used as an inflammatory model to explore the mechanism of dynorphin regulating microglial polarization. RESULTS: Overexpression of the dynorphin precursor protein prodynorphin (PDYN) alleviated the pilocarpine-induced neuronal apoptosis, promoted microglial polarization to the M2 phenotype, and inhibited pilocarpine-induced Toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) pathway in the hippocampi of epileptic rats. Dynorphin activation of KOR promoted microglial M2 polarization via inhibiting TLR4/NF-κB pathway in LPS-stimulated BV-2 microglial cells. Moreover, dynorphin/KOR regulated microglial M2 polarization inhibited apoptosis of the primary mouse hippocampal neurons. CONCLUSION: In conclusion, dynorphin activation of KOR promotes microglia polarization toward M2 phenotype via inhibiting TLR4/NF-κB pathway.