The novel FAAH inhibitor, MCH1, reduces the infarction area in the motor cortex-related region but does not affect the sensorimotor function or memory and spatial learning in rats exposed to transient middle cerebral artery occlusion

Macamides, amides of fatty acids first isolated from maca (Lepidium meyenii) are potentially responsible for the reduction of ischemic injury in the stroke animal model followed by maca extract administration. This deduction comes from its ability to inhibit the fatty acid amide hydrolase activity, an enzyme related to the endocannabinoid anandamide hydrolysis. However, no study about the effects of isolated macamides on in-vivo models has been published yet. Our objective was to evaluate the effect of a 10-day 30 mg/kg i.p. MCH1 administration, the macamide with the higher FAAH inhibition capability, on the neurological recovery and brain infarction area of Sprague-Dawley rats exposed to the transient middle cerebral artery occlusion (MCAO) model. Our results showed that the group receiving MCH1 for 10 days did not improve Garcia's neurological score compared to receiving the vehicle only. Likewise, the MCH1 group did not improve their sensorimotor dysfunction as indicated by the latency to detect and remove the tape from the contralateral forepaw in the adhesive removal test, and a similar number of errors with the contralateral forepaw in the foot fault test compared to the vehicle group at the 10th day. Evaluation of the spatial memory and learning using the Barnes test showed longer latency to reach the escape box in the Vehicle and MCH1 groups compared to the control group (no MCAO) only in the retrieval test, while no effect of MCAO procedure or MCH1 administration was observed in the reversal learning test. Despite the lack of behavioral effect of MCH1, analysis of the infarcted areas in the brain using the 2, 3, 5-Triphenyltetrazolium chloride (TTC) staining method in the seven consecutive coronal sections revealed that the infarcted area in the first (bregma + 4.2 mm) and fifth (bregma -3.8 mm) coronal sections of the MCAO + MCH1 group remained similar to the Control group. These results provide evidence that MCH1 can limit damage from ischemic stroke, although it is not reflected in neurological or sensorimotor behavior and spatial learning and memory.

WRN modulates translation by influencing nuclear mRNA export in HeLa cancer cells

BACKGROUND

The Werner syndrome protein (WRN) belongs to the RecQ family of helicases and its loss of function results in the premature aging disease Werner syndrome (WS). We previously demonstrated that an early cellular change induced by WRN depletion is a posttranscriptional decrease in the levels of enzymes involved in metabolic pathways that control macromolecular synthesis and protect from oxidative stress. This metabolic shift is tolerated by normal cells but causes mitochondria dysfunction and acute oxidative stress in rapidly growing cancer cells, thereby suppressing their proliferation.

RESULTS

To identify the mechanism underlying this metabolic shift, we examined global protein synthesis and mRNA nucleocytoplasmic distribution after WRN knockdown. We determined that WRN depletion in HeLa cells attenuates global protein synthesis without affecting the level of key components of the mRNA export machinery. We further observed that WRN depletion affects the nuclear export of mRNAs and demonstrated that WRN interacts with mRNA and the Nuclear RNA Export Factor 1 (NXF1).

CONCLUSIONS

Our findings suggest that WRN influences the export of mRNAs from the nucleus through its interaction with the NXF1 export receptor thereby affecting cellular proteostasis. In summary, we identified a new partner and a novel function of WRN, which is especially important for the proliferation of cancer cells.