BACKGROUND Frontotemporal lobar degeneration (FTLD) is the third most common dementing neurodegenerative disease with nearly 80% having no known etiology. OBJECTIVE Growing evidence that neurodegeneration can be linked to dysregulated metabolism prompted us to measure a panel of trophic factors, receptors, and molecules that modulate brain metabolic function in FTLD. METHODS Postmortem frontal (Brodmann's area [BA]8/9 and BA24) and temporal (BA38) lobe homogenates were used to measure immunoreactivity to Tau, phosphorylated tau (pTau), ubiquitin, 4-hydroxynonenal (HNE), transforming growth factor-beta 1 (TGF-β1) and its receptor (TGF-β1R), brain-derived neurotrophic factor (BDNF), nerve growth factor, neurotrophin-3, neurotrophin-4, tropomyosin receptor kinase, and insulin and insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-2 (IGF-2) and their receptors by direct-binding enzyme-linked immunosorbent assay. RESULTS FTLD brains had significantly elevated pTau, ubiquitin, TGF-β1, and HNE immunoreactivity relative to control. In addition, BDNF and neurotrophin-4 were respectively reduced in BA8/9 and BA38, while neurotrophin-3 and nerve growth factor were upregulated in BA38, and tropomyosin receptor kinase was elevated in BA24. Lastly, insulin and insulin receptor expressions were elevated in the frontal lobe, IGF-1 was increased in BA24, IGF-1R was upregulated in all three brain regions, and IGF-2 receptor was reduced in BA24 and BA38. CONCLUSIONS Aberrantly increased levels of pTau, ubiquitin, HNE, and TGF-β1, marking neurodegeneration, oxidative stress, and neuroinflammation, overlap with altered expression of insulin/IGF signaling ligand and receptors in frontal and temporal lobe regions targeted by FTLD. Dysregulation of insulin-IGF signaling networks could account for brain hypometabolism and several characteristic neuropathologic features that characterize FTLD but overlap with Alzheimer's disease, Parkinson's disease, and Dementia with Lewy Body Disease.

中文翻译：

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额颞叶变性中胰岛素和胰岛素样生长因子的脑表达改变：另一种与胰岛素代谢途径失调相关的退行性疾病。


背景 额颞叶变性 (FTLD) 是第三种最常见的痴呆性神经退行性疾病，其中近 80% 的病因不明。目的 越来越多的证据表明神经退行性变可能与代谢失调有关，促使我们测量一组调节 FTLD 脑代谢功能的营养因子、受体和分子。方法 使用死后额叶（布罗德曼区 [BA]8/9 和 BA24）和颞叶（BA38）匀浆来测量对 Tau、磷酸化 tau (pTau)、泛素、4-羟基壬烯醛 (HNE)、转化生长因子-β 的免疫反应性1 (TGF-β1) 及其受体 (TGF-β1R)、脑源性神经营养因子 (BDNF)、神经生长因子、神经营养蛋白-3、神经营养蛋白-4、原肌球蛋白受体激酶以及胰岛素和胰岛素样生长因子-1 (IGF-1) 和胰岛素样生长因子-2 (IGF-2) 及其受体通过直接结合酶联免疫吸附测定。结果 与对照组相比，FTLD 大脑的 pTau、泛素、TGF-β1 和 HNE 免疫反应性显着升高。此外，BA8/9和BA38中BDNF和神经营养素4分别减少，而BA38中神经营养素3和神经生长因子上调，BA24中原肌球蛋白受体激酶升高。最后，额叶中胰岛素和胰岛素受体表达升高，BA24中IGF-1升高，所有三个脑区IGF-1R表达上调，BA24和BA38中IGF-2受体降低。结论 pTau、泛素、HNE 和 TGF-β1 水平异常升高，标志着神经退行性变、氧化应激和神经炎症，与 FTLD 靶向的额叶和颞叶区域胰岛素/IGF 信号配体和受体表达的改变重叠。 胰岛素-IGF信号网络的失调可以解释大脑代谢低下和一些典型的神经病理学特征，这些特征是FTLD的特征，但与阿尔茨海默病、帕金森病和路易体病痴呆有重叠。