基于miR-23a-3p的Oatp2、P-gp调控对难治性癫痫耐药的影响

Antiepileptic drugs are ineffective in approximately one-third of patients with epilepsy, leading to enduringseizures, neurological impairment and decreased survivability. The mechanisms underlying this multidrug resistance are not fully understood.Thus, identifying the causes of intractable epilepsy and finding targets for intervention takes on greater significance. . As an important posttranscriptional regulator, MiRNA can regulate the expression of drug transporters which are involved in drug resistance, by influencing intracerebral transport of antiepileptic drugs.. Based on our previous studies, which was found that: 1) the influx drug transporter Oatp2 and the efflux transporter P-gp were involved in drug resistance of valproic acid, the most commonly used broad-spectrum antiepileptic drugs; 2) Blood miR-23a-3p was highly increased in children with refractory epilepsy;3) Both the Oatp2 and P-gp genes may be the target genes for miR-23a-3p. So we put forward our scientific hypotheses: the regulation of miR-23a-3p can regulate the expression of Oatp2 and P-gp, then affect the intracerebral transport of valproic acid, thus affect its efficacy.. In this research, firstly, we systematically confirmed that miR-23a-3p can regulate the expression of Oatp2 and P-gp; then the relationship between miR-23a-3p and the expression of these two transporters ; the effect of miR-23a-3p regulating on the intracerebral transport and drug resistance of valproic acid, also the safety of treatment were studied in vivo and in vitro study. thus those above scientific hypotheses were fully confirmed. . This is an original research, and its results can provide new ideas for the exploration of more effective and safer methods, to improve the drug resistance of epilepsy.

难治性癫痫发病率高危害大，对耐药成因及改善方法的探索是神经科学研究的难点。药物转运体通过影响抗癫痫药脑内转运参与耐药；MiRNA为重要的转录后调控因子，可调控药物转运体表达。基于前期研究发现内流转运体Oatp2和外排转运体P-gp均参与最常用的广谱抗癫痫药丙戊酸耐药；难治性癫痫患儿血miR-23a-3p差异性高表达；Oatp2和P-gp基因均可能是miR-23a-3p的靶基因。提出科学假设：调控miR-23a-3p可通过调控Oatp2、P-gp表达，影响丙戊酸的脑内转运，进而影响其疗效。本研究首先系统证实miR-23a-3p对Oatp2及P-gp的表达调控作用；进而从在体及体外层面研究miR-23a-3p与两转运体的表达相关性，调控miR-23a-3p对脑内丙戊酸转运及耐药的影响并评价治疗安全性，充分证实上述科学假设。此为原创性研究，研究结果可为探寻更有效安全的癫痫耐药改善方法提供新线索。

难治性癫痫发病率高危害大，对耐药成因及改善方法的探索是神经科学研究的难点。药物转运体通过影响抗癫痫药脑内转运参与耐药；MiRNA为重要的转录后调控因子，可调控药物转运体表达。基于前期研究发现内流转运体Oatp2和外排转运体P-gp均参与最常用的广谱抗癫痫药丙戊酸耐药；难治性癫痫患儿血miR-23a-3p差异性高表达；Oatp2和P-gp基因均可能是miR-23a-3p的靶基因。我们以可能对药物转运体有重要调控作用的miR-23a-3p为切入点，研究是否调控miR-23a-3p可通过影响药物转运体Oatp2及P-gp的表达，影响丙戊酸的脑内转运，进而影响丙戊酸在难治性癫痫治疗中的疗效。本研究提出的科学假设为：调控miR-23a-3p可通过调控Oatp2、P-gp表达，影响丙戊酸的脑内转运，进而影响其疗效。.为了证实以上的科学假设，本研究首先系统证实miR-23a-3p对Oatp2及P-gp的表达调控作用；进而从在体及体外层面研究miR-23a-3p与两转运体的表达相关性，调控miR-23a-3p对脑内丙戊酸转运及耐药的影响并评价治疗安全性。本研究结合在体及体外研究得出以下结果：大鼠体内miR-23a-3p分布具有组织差异，（肝组织>脑组织>肾组织>血液）、年龄差异（幼年大鼠>成年大鼠），病理状态差异（惊厥增加表达），且在难治性癫痫大鼠脑内miR-23a-3p与内流型药物转运体Oatp2表达呈正相关；miR-23a-3p参与内流型药物转运体Oatp2的表达调控；通过调控miR-23a-3p表达，可改善耐药（丙戊酸）癫痫动物的耐药，同时改善大鼠的认知功能，且未明显增加丙戊酸的副作用。但miR-23a-3p对外流型转运体P-gp的表达无明确调控作用。综合以上研究结果，我们得出miR-23a-3p可通过调控内流药物转运体而参与难治性癫痫耐药，从而可以作为难治性癫痫的有效且安全的治疗靶点，研究结果证实了本研究提出的科学假设，且可为探寻更有效安全的癫痫耐药改善方法提供新线索，具有临床应用的价值及应用前景。