scholarly journals Structure‐activity Relationship of the Transient Receptor Potential Melastatin 2 (TRPM2) and a Novel Peptide Antagonist Tat‐M2NX: Potential Therapeutic Target in Cerebral Ischemia

2018 ◽  
Vol 32 (S1) ◽  
Author(s):  
Ivelisse Cruz‐Torres ◽  
Paco S. Herson
Cells ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 231 ◽  
Author(s):  
Dae Hong ◽  
Bo Choi ◽  
A Kho ◽  
Song Lee ◽  
Jeong Jeong ◽  
...  

Over the last two decades, evidence supporting the concept of zinc-induced neuronal death has been introduced, and several intervention strategies have been investigated. Vesicular zinc is released into the synaptic cleft, where it then translocates to the cytoplasm, which leads to the production of reactive oxygen species and neurodegeneration. Carvacrol inhibits transient receptor potential melastatin 7 (TRPM7), which regulates the homeostasis of extracellular metal ions, such as calcium and zinc. In the present study, we test whether carvacrol displays any neuroprotective effects after global cerebral ischemia (GCI), via a blockade of zinc influx. To test our hypothesis, we used eight-week-old male Sprague–Dawley rats, and a GCI model was induced by bilateral common carotid artery occlusion (CCAO), accompanied by blood withdrawal from the femoral artery. Ischemic duration was defined as a seven-minute electroencephalographic (EEG) isoelectric period. Carvacrol (50 mg/kg) was injected into the intraperitoneal space once per day for three days after the onset of GCI. The present study found that administration of carvacrol significantly decreased the number of degenerating neurons, microglial activation, oxidative damage, and zinc translocation after GCI, via downregulation of TRPM7 channels. These findings suggest that carvacrol, a TRPM7 inhibitor, may have therapeutic potential after GCI by reducing intracellular zinc translocation.


2020 ◽  
Author(s):  
Haoqiang Lai ◽  
Chang Liu ◽  
Wenwei Lin ◽  
tf Chen ◽  
An Hong

Abstract Background Lung cancer possesses high mortality rate and tolerances to multiple chemotherapeutics. Natural Borneol (NB) is a monoterpenoid compound that found to facilitate the bioavailability of drugs. In this study, we attempted to investigate effects of NB on the chemosensitivity in A549 cells and try to elucidate its therapeutic target. Methods The effects of NB on chemosensitivity in A549 cells was examined by MTT assay. The mechanism studies were evaluated by flow cytometry and western blotting assay. Surface plasmon resonance (SPR) and LC-MS combined analysis (MS-SPRi) was performed to elucidate the candidate target of NB contributes to this synergism. The chemosensitizing capacity of NB in vivo was conducted in nude mice bearing A549 tumors. Results NB pretreatment sensitizes A549 cells to low dosage of DOX, leading to a 15.7% to 41.5% increase in apoptosis, which is corelated with ERK and AKT inactivation but activation of phosphor-p38MAPK, -JNK and p53. Furthermore, this synergism depends on reactive oxygen species (ROS) generation. The MS-SPRi analysis reveals that the transient receptor potential melastatin-8 (TRPM8) is the interaction target of NB in potentiating DOX killing potency. Genetically knock down of TRPM8 significantly suppress the chemosensitizing effects of NB with the involvement of inhibiting ROS generation through restraining calcium mobilization. Moreover, pretreatment of NB synergistically enhanced the anticancer effects of DOX to delay tumor progression in vivo. Conclusions These results suggest that TRPM8 may be a valid therapeutic target in the potential application of NB serves as a chemosensitizer for lung cancer treatment.


2020 ◽  
Vol 21 (17) ◽  
pp. 6026 ◽  
Author(s):  
Dae Ki Hong ◽  
A Ra Kho ◽  
Song Hee Lee ◽  
Jeong Hyun Jeong ◽  
Beom Seok Kang ◽  
...  

A variety of pathogenic mechanisms, such as cytoplasmic calcium/zinc influx, reactive oxygen species production, and ionic imbalance, have been suggested to play a role in cerebral ischemia induced neurodegeneration. During the ischemic state that occurs after stroke or heart attack, it is observed that vesicular zinc can be released into the synaptic cleft, and then translocated into the cytoplasm via various cation channels. Transient receptor potential melastatin 2 (TRPM2) is highly distributed in the central nervous system and has high sensitivity to oxidative damage. Several previous studies have shown that TRPM2 channel activation contributes to neuroinflammation and neurodegeneration cascades. Therefore, we examined whether anti-oxidant treatment, such as with N-acetyl-l-cysteine (NAC), provides neuroprotection via regulation of TRPM2, following global cerebral ischemia (GCI). Experimental animals were then immediately injected with NAC (150 mg/kg/day) for 3 and 7 days, before sacrifice. We demonstrated that NAC administration reduced activation of GCI-induced neuronal death cascades, such as lipid peroxidation, microglia and astroglia activation, free zinc accumulation, and TRPM2 over-activation. Therefore, modulation of the TRPM2 channel can be a potential therapeutic target to prevent ischemia-induced neuronal death.


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