Adenosine kinase gene modified mesenchymal stem cell transplantation retards seizure severity and associated cognitive impairment in a temporal lobe epilepsy rat model.

PURPOSE: Temporal lobe epilepsy (TLE) has a high risk of developing drug resistant and cognitive comorbidities. Adenosine has potential anticonvulsant effects as an inhibitory neurotransmitter, but drugs targeting its receptors and metabolic enzyme has inevitable side effects. Therefore, we investigated adenosine augmentation therapy for seizure control and cognitive comorbidities in TLE animals.

METHODS: Using lentiviral vectors coexpressing miRNA inhibiting the expression of adenosine kinase (ADK), we produced ADK- -rMSC (ADK knockdown rat mesenchymal stem cell). ADK- -rMSC and LV-con-rMSC (rMSC transduced by randomized scrambled control sequence) were transplanted into the hippocampus of TLE rat respectively. ADK- +DPCPX group was transplanted with ADK- -rMSC and intraperitoneally injected with DPCPX (adenosine A1 receptor antagonist). Seizure behavior, EEG, CA1 pyramidal neuron apoptosis, and behavior in Morris water maze and novel object recognition test were studied RESULTS: Adenosine concentration in the supernatants of 105 ADK- -rMSCs was 13.8 ng/ml but not detectable in LV-con-rMSCs. ADK- -rMSC (n = 11) transplantation decreased spontaneous recurrent seizure (SRS) duration compared to LV-con-rMSC (n = 11, P < 0.05). CA1 neuron apoptosis was decreased in ADK- -rMSC (n = 3, P < 0.05). ADK- -rMSC (n = 11) improved the Morris water maze performance of TLE rats compared to LV-con-rMSC (n = 11, escape latency, P < 0.01; entries in target quadrant, P < 0.05). The effect of ADK- -rMSC on neuron apoptosis and spatial memory were counteracted by DPCPX. However, ADK- -rMSC didn't improve the performance in novel object recognition test.

CONCLUSION: Adenosine augmentation-based ADK- -rMSC transplantation is a promising therapeutic candidate for TLE and related cognitive comorbidities.