低血糖症相关自主神经功能衰竭(HAAF)是一种公认的糖尿病并发症。虽然HAAF有严重的结果,如复发性发病率,昏迷,和死亡,HAAF的机制及其病理成分在很大程度上是未知的。我们以前的研究表明,低血糖与立即早期基因FOS的上调有关。此外,据记载,葡萄糖剥夺激活神经元自噬活动。因此,本研究旨在明确自噬途径的核心成分之一FOS的作用,Beclin-1(由BECN1基因编码),在调节胚胎下丘脑神经元对低血糖条件的自噬机制中。胚胎小鼠下丘脑细胞系N39(mHypoE-N39或N39)在降低的葡萄糖浓度(2000、900、500和200mg/L)中培养。基因和蛋白质表达,在有和没有FOS和BECN1基因敲除(KD)的N39下丘脑神经元中,在不同的葡萄糖降低浓度下进行了自噬的免疫荧光研究。本研究的结果表明,响应于降低的葡萄糖浓度,下丘脑神经元中自噬体形成和随后的溶酶体降解显着增加。在FOSKD和BECN1KD细胞中,这种低血糖反应似乎降低到相似的程度,尽管与阴性对照相比微不足道,表明FOS参与下丘脑神经元对低血糖的自噬反应。此外,与对照细胞相比,KD细胞表现出形态变化和细胞活力降低。我们的研究结果表明,减少的FOS表达可能与依赖BECN1的自噬活动受损有关,这可能导致对低血糖反应的下丘脑激活减少或减弱。而这个,反过来,可能有助于HAAF的发展。
Hypoglycemia-associated autonomic failure (HAAF) is a well-established complication of diabetes. Although HAAF has serious outcomes such as recurrent morbidity, coma, and death, the mechanisms of HAAF and its pathological components are largely unknown. Our previous studies have revealed that hypoglycemia is associated with the upregulation of an immediate early gene - FOS. In addition, it is documented that glucose deprivation activates neuronal autophagic activities. Therefore, the present study aimed to identify the role of FOS and one of the core components of the autophagy pathway, Beclin-1 (encoded by the BECN1 gene), in the regulation of autophagic mechanisms in embryonic hypothalamic neurons in response to hypoglycemic conditions. Embryonic Mouse Hypothalamic Cell Line N39 (mHypoE-N39 or N39) was cultured in reduced concentrations of glucose (2000, 900, 500, and 200 mg/L). Gene and protein expression, as well as immunofluorescence studies on autophagy were conducted under different reduced glucose concentrations in N39 hypothalamic neurons with and without FOS and BECN1 gene knockdowns (KD). The outcomes of the present study have demonstrated a significant increase in autophagosome formation and subsequent lysosomal degradation in the hypothalamic neurons in response to reduced glucose concentrations. This hypoglycemic response appears to be lowered to a similar extent in the FOS KD and BECN1 KD cells, albeit insignificantly from the negative control, is indicative of the involvement of FOS in the autophagic response of hypothalamic neurons to hypoglycemia. Moreover, the KD cells exhibited a change in morphology and reduced cell viability compared with the control cells. Our findings suggest that reduced FOS expression could potentially be associated with impaired autophagic activities that are dependent on BECN1, which could lead to decreased or blunted hypothalamic activation in response to hypoglycemia, and this, in turn, may contribute to the development of HAAF.