TNFα induces Ca2+ influx to accelerate extrinsic apoptosis in hepatocellular carcinoma cells

Xie

et al. 2019

Preprint

Background: Neuropathic pain is a serious clinical problem to be solved. Protein kinase A (PKA) is widely distributed in the central nervous system and participates in various signal transduction pathways to regulate cell proliferation and apoptosis. However, it is unclear whether PKA is involved in neuropathic pain. This study aimed to investigate PKA expression in neuropathic pain and its possible mechanisms of involvement. Methods: The mRNA expression dataset of neuropathic pain (GSE24982) was downloaded from the Gene Expression Omnibus database, and differentially expressed genes (DEGs) were screened using the R software. DEGs were subjected to Gene Ontology term and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses. A protein-protein interaction network was constructed using the STRING database, and the Cytoscape plug-in cytoHubba was used to screen for hub genes. A spared nerve injury (SNI) rat model was established and the paw withdrawal threshold was determined using von Frey filaments. Western blotting and immunofluorescence were used to detect the expression and cellular localization of key proteins in the spinal cord, respectively. Western blotting, ELISA, and TUNEL assays were used to detect cell signal transduction, inflammation, and apoptosis, respectively. Results: Among 449 DEGs and 20 hub genes, PKA was identified as a key gene involved in neuropathic pain. After SNI, mechanical allodynia occurred, PKA expression in the spinal cord increased, the p38MAPK pathway was activated, and spinal cord inflammation and apoptosis occurred in rats. Immunofluorescence staining showed that PKA colocalized with neurons, astrocytes, and microglia, and TUNEL with GFAP, Iba-1, Neun double labeling showed that apoptotic cells were mainly neurons. Intrathecal injection of a PKA inhibitor not only relieved mechanical hyperalgesia, inflammatory reaction, and apoptosis in SNI rats, but also inhibited p38MAPK pathway activation. Intrathecal injection of a p38MAPK inhibitor attenuated mechanical hyperalgesia, inflammatory reaction, and apoptosis, but did not affect PKA expression. Conclusions: PKA is involved in neuropathic pain by activating the p38MAPK pathway to mediate spinal cord cell apoptosis. This study provides novel insights that my aid in the elucidation of the pathogenesis of neuropathic pain.

Section: Discussionsupporting

confidence: 78%

Protein kinase A is involved in neuropathic pain by activating the p38MAPK pathway to mediate spinal cord cell apoptosis

Deng

Xie

et al. 2019

Preprint

“…SNI induced inflammation in the spinal cord and increased TNF-α and IL-1β expression. In line herewith, numerous studies have shown that the proinflammatory factors TNF-α and IL-1β can induce apoptosis [44,45].…”

supporting

confidence: 78%

Protein Kinase A Is Involved in Neuropathic Pain by Activating the p38MAPK Pathway to Mediate Spinal Cord Cell Apoptosis

Deng

Mediators of Inflammation

Xie

et al. 2020

Neuropathic pain is a serious clinical problem to be solved. This study is aimed at investigating protein kinase A (PKA) expression in neuropathic pain and its possible mechanisms of involvement. A neuropathic pain-related gene expression dataset was downloaded from Gene Expression Omnibus, and differentially expressed genes were screened using the R software. cytoHubba was used to screen for hub genes. A spared nerve injury (SNI) rat model was established, and the paw withdrawal threshold was determined using von Frey filaments. Western blotting and immunofluorescence were used to detect the expression and cellular localization, respectively, of key proteins in the spinal cord. Western blot, ELISA, and TUNEL assays were used to detect cell signal transduction, inflammation, and apoptosis, respectively. Pka was identified as a key gene involved in neuropathic pain. After SNI, mechanical allodynia occurred, PKA expression in the spinal cord increased, the p38MAPK pathway was activated, and spinal cord inflammation and apoptosis occurred in rats. PKA colocalized with neurons, astrocytes, and microglia, and apoptotic cells were mainly neurons. Intrathecal injection of a PKA inhibitor not only relieved mechanical hyperalgesia, inflammatory reaction, and apoptosis in SNI rats but also inhibited p38MAPK pathway activation. However, intrathecal injection of a p38MAPK inhibitor attenuated mechanical hyperalgesia, inflammation, and apoptosis, but did not affect PKA expression. In conclusion, PKA is involved in neuropathic pain by activating the p38MAPK pathway to mediate spinal cord cell apoptosis.

“…In all statistical analyses * * * p < 0.001 when compared with the 0 mg/ml CA. (Chemaly et al, 2018), and the Ca 2+ level in the cytoplasm is always elevated during the process of cell apoptosis (Zhu et al, 2018). In this study, we selected the Fluo-3/AM and Rhod-2/AM stains to detect the levels of Ca 2+ in the cytoplasm and mitochondria.…”

Section: Ca Increased Cytoplasmic and Mitochondrial Ca 2+ Levelsmentioning

confidence: 99%

Cinnamaldehyde, a Promising Natural Preservative Against Aspergillus flavus

Chen

et al. 2019

Front. Microbiol.

The problem of food spoilage due to Aspergillus flavus (A. flavus) needs to be resolved. In this study, we found that the minimum inhibitory concentration of cinnamaldehyde (CA) that inhibited A. flavus was 0.065 mg/ml and that corn can be prevented from spoiling at a concentration of 0.13 mg/cm 3. In addition to inhibiting spore germination, mycelial growth, and biomass production, CA can also reduce ergosterol synthesis and can cause cytomembrane damage. Our intention was to elucidate the antifungal mechanism of CA. Flow cytometry, fluorescence microscopy, and western blot were used to reveal that different concentrations of CA can cause a series of apoptotic events in A. flavus, including elevated Ca 2+ and reactive oxygen species, decrease in mitochondrial membrane potential (ψ m), the release of cytochrome c, the activation of metacaspase, phosphatidylserine (PS) externalization, and DNA damage. Moreover, CA significantly increased the expression levels of apoptosis-related genes (Mst3, Stm1, AMID, Yca1, DAP3, and HtrA2). In summary, our results indicate that CA is a promising antifungal agent for use in food preservation.