Effect of Khat on apoptosis and related gene Smac/DIABLO expression in the cerebral cortex of rats following transient focal ischemia

Anti-apoptosis effect of traditional Chinese medicine in the treatment of cerebral ischemia-reperfusion injury

Cerebral ischemia, one of the leading causes of neurological dysfunction of brain cells, muscle dysfunction, and death, brings great harm and challenges to individual health, families, and society. Blood flow disruption causes decreased glucose and oxygen, insufficient to maintain normal brain tissue metabolism, resulting in intracellular calcium overload, oxidative stress, neurotoxicity of excitatory amino acids, and inflammation, ultimately leading to neuronal cell necrosis, apoptosis, or neurological abnormalities. This paper summarizes the specific mechanism of cell injury that apoptosis triggered by reperfusion after cerebral ischemia, the related proteins involved in apoptosis, and the experimental progress of herbal medicine treatment through searching, analyzing, and summarizing the PubMed and Web Of Science databases, which includes active ingredients of herbal medicine, prescriptions, Chinese patent medicines, and herbal extracts, providing a new target or new strategy for drug treatment, and providing a reference for future experimental directions and using them to develop suitable small molecule drugs for clinical application. With the research of anti-apoptosis as the core, it is important to find highly effective, low toxicity, safe and cheap compounds from natural plants and animals with abundant resources to prevent and treat Cerebral ischemia/reperfusion (I/R) injury (CIR) and solve human suffering. In addition, understanding and summarizing the apoptotic mechanism of cerebral ischemia-reperfusion injury, the microscopic mechanism of CIR treatment, and the cellular pathways involved will help to develop new drugs.

The study of microtubule dynamics and stability at the postsynaptic density in a rat pilocarpine model of temporal lobe epilepsy

Background

The recurrence and drug resistance of temporal lobe epilepsy (TLE) has been ceaselessly challenging scientists and epilepsy experts. There has been an accumulation of evidence linking the dysregulation of postsynaptic proteins etiology and the pathology of epilepsy. For example, NMDA receptors, AMPA receptors, and metabotropic glutamate receptors (mGluRs). Furthermore, our earlier proteomic analysis proved there to be differential expressions of cytoskeletons like microtubules among rat groups. These differential expressions were shown in TLE-spontaneous recurrent seizures (TLE-SRS), TLE without SRS (TLE-NSRS) and control groups. Therefore, we aimed to understand how the microtubule system of the hippocampal postsynaptic density (PSD) regulates the development of TLE.

Methods

In this study, a pilocarpine-induced Sprague-Dawley rat TLE model were used, and Western blot, Nissl staining, and the immunoelectron microscopic method were utilized to determine the dynamic change of microtubules (α- and β-tubulin) in PSD and the extent of hippocampal neuron loss respectively in acute SE, and latent and chronic (spontaneous seizures) periods. Animal models were then stereotactically treated using colchicine, a microtubule depolymerizer, and paclitaxel, a microtubule polymerization agent, after each animal's acute SE period so as to further explore the function of PSD microtubules.

Results

Our study revealed 3 principal findings. One, both α- and β-tubulin were decreased from the 3^rd to the 30^th day (lowest at the 7^th day) in the seizure group compared with the controls. Two, both α- and β-tubulin were found to be more downregulated in the TLE-SRS and the TLE-NSRS group than in the control group (especially in the TLE-SRS group). The same trend was also noticed for hippocampal neuron loss. Three, the paclitaxel lowered the chronic SRS rate and increased the expression of PSD β-tubulin in the hippocampus.

Conclusions

Altogether, these results indicate that the microtubule system of PSD may play an essential role in the development and recurrence of epilepsy, and it may be used as a new target for the prevention and treatment of this refractory disease.

Gene Network Dysregulation in the Trigeminal Ganglia and Nucleus Accumbens of a Model of Chronic Migraine-Associated Hyperalgesia

The pharmacological agent nitroglycerin (NTG) elicits hyperalgesia and allodynia in mice. This model has been used to study the neurological disorder of trigeminovascular pain or migraine, a debilitating form of hyperalgesia. The present study validates hyperalgesia in an established mouse model of chronic migraine triggered by NTG and advances the understanding of the associated molecular mechanisms. The RNA-seq profiles of two nervous system regions associated with pain, the trigeminal ganglia (TG) and the nucleus accumbens (NAc), were compared in mice receiving chronic NTG treatment relative to control (CON) mice. Among the 109 genes that exhibited an NTG treatment-by-region interaction, solute carrier family 32 (GABA vesicular transporter) member 1 (Slc32a1) and preproenkephalin (Penk) exhibited reversal of expression patterns between the NTG and CON groups. Erb-b2 receptor tyrosine kinase 4 (Erbb4) and solute carrier family 1 (glial high affinity glutamate transporter) member 2 (Slc1a2) exhibited consistent differential expression between treatments across regions albeit at different magnitude. Period circadian clock 1 (Per1) was among the 165 genes that exhibited significant NTG treatment effect. Biological processes disrupted by NTG in a region-specific manner included adaptive and innate immune responses; whereas glutamatergic and dopaminergic synapses and rhythmic process were disrupted in both regions. Regulatory network reconstruction highlighted the widespread role of several transcription factors (including Snrnp70, Smad1, Pax6, Cebpa, and Smpx) among the NTG-disrupted target genes. These results advance the understanding of the molecular mechanisms of hyperalgesia that can be applied to therapies to ameliorate chronic pain and migraine.

Insight into the negative impact of ionic liquid: A cytotoxicity mechanism of 1-methyl-3-octylimidazolium bromide

Ionic liquids (ILs) as a green replacement for volatile organic solvents are increasingly used in large-scale commercial applications. A good understanding of the toxic mechanisms and environmental impact of ILs is neede to reduce the risk for human health and the environment. For this purpose, we aimed to evaluate the possible impacts of 1-methyl-3-octylimidazolium bromide ([C₈mim]Br) exposure on human hepatocellular carcinoma (HepG2) cells as to elucidate the cytotoxic mechanism of [C₈mim]Br. Biochemical assays revealed that [C₈mim]Br exposure altered the protein levels of heat shock protein 70 (HSP70) and HSP90, generally inhibiting total antioxidative capacity (T-AOC), depleting heme oxygenase-1 (HO-1) and increasing transcription and activity of inducible nitric oxide synthase (iNOS) in HepG2 cells. These results indicated that [C₈mim]Br may induce biochemical disturbances and cause oxidative stress in HepG2 cells. Moreover, increased phosphorylation of p53, mitochondrial membrane disruption, cyclooxygenase-2 activation, Bcl-2 family protein modulation, cytochrome c and Smac/DIABLO release, and inhibition of apoptosis inhibitory protein-2 (c-IAP2) and survivin were also observed in [C₈mim]Br-treated cells, suggesting that [C₈mim]Br-induced apoptosis might be mediated by the mitochondrial pathway. Further research showed that [C₈mim]Br exposure increased tumour necrosis factor α (TNF-α) transcription and content and promoted the expression of Fas and FasL, indicating that TNF-α and Fas/FasL are involved in the apoptosis induced by [C₈mim]Br. Additionally, [C₈mim]Br cytotoxicity was partly inhibited by N-acetyl-cysteine (NAC), and NAC reversed [C₈mim]Br-mediated mitochondrial dysfunction and blocked apoptotic events by inhibiting the generation of reactive oxygen species (ROS). This work first demonstrated that the ROS-mediated mitochondrial and death receptor-initiated apoptotic pathway is involved in [C₈mim]Br-induced HepG2 cell apoptosis.