16 research outputs found
Chronic oleoylethanolamide treatment attenuates diabetes-induced mice encephalopathy by triggering peroxisome proliferator-activated receptor alpha in the hippocampus.
Brain is a site of diabetic end-organ damage. Diabetes-associated cognitive dysfunction, referred as "diabetic encephalopathy" (DE) has been coined for the patients with type 2 diabetes mellitus showing decline in their cognitive function, especially weak episodic memory, cognitive inflexibility and poor psychomotor performance leading towards Alzheimer’s disease. Current evidence supported that aberrant synapses, energy metabolism imbalance, advanced glycation end products (AGEs) accumulation and Tau hyperphosphorylation are associated with cognition deficits induced by diabetes. Oleoylethanolamide (OEA), an endogenous peroxisome proliferator-activated receptor alpha (PPARα) agonist, has anti-hyperlipidemia, anti-inflammatory and neuroprotective activities. However, the effect of OEA on DE is unknown. Therefore, we tested its influence against cognitive dysfunction in high fat diet and streptozotocin (HFD + STZ)-induced diabetic C57BL/6J and PPARα--/- mice using Morris water maze (MWM) test. Neuron staining, dementia markers and neuroplasticity in the hippocampus were assessed to evaluate the neuropathological changes. The results showed that chronic OEA treatment significantly lowered hyperglycemia, recovered cognitive performance, reduced dementia markers, and inhibited hippocampal neuron loss and neuroplasticity impairments in diabetic mice. In contrast, the changes in MWM performance and neuron loss were not observed in PPARα knockout mice via OEA administration. These results indicated that OEA may provide a potential alternative therapeutic for DE by activating PPARα signaling
Soluble TREM2 ameliorates pathological phenotypes by modulating microglial functions in an Alzheimer's disease model
阿尔茨海默病(Alzheimer’s Disease, AD)是一种以渐进性认知功能丧失为主要特征的神经退行性疾病,是最为常见的老年痴呆类型。随着全球人口老龄化的加剧,AD正在成为二十一世纪最大的疾病之一。该研究首次揭示sTREM2在AD中具有重要的保护功能,提出sTREM2或可用于AD治疗的新观点,同时也进一步佐证了小胶质细胞在AD治疗中的核心作用,研究为AD等神经退行性疾病的防治开辟了新思路、提供了新靶点。
厦门大学医学院博士后钟力和硕士研究生徐颖为论文共同第一作者,陈小芬教授和卜国军教授为该论文的共同通讯作者。厦门大学的文磊、孙灏、卓仁恭等教授和美国Sanford-Burnham-Prebys医学研究所的许华曦教授共同参与了该项目的研究。【Abstract】Triggering receptor expressed on myeloid cells 2 (TREM2) is a microglial surface receptor genetically linked to the risk for Alzheimer’s disease (AD). A proteolytic product, soluble TREM2 (sTREM2), is abundant in the cerebrospinal fluid and its levels positively correlate with neuronal injury markers. To gain insights into the pathological roles of sTREM2, we studied sTREM2 in the brain of 5xFAD mice, a model of AD, by direct stereotaxic injection of recombinant sTREM2 protein or by adeno-associated virus (AAV)-mediated expression. We found that sTREM2 reduces amyloid plaque load and rescues functional deficits of spatial memory and long-term potentiation. Importantly, sTREM2 enhances microglial proliferation, migration, clustering in the vicinity of amyloid plaques and the uptake and degradation of Aβ. Depletion of microglia abolishes the neuroprotective effects of sTREM2. Our study demonstrates a protective role of sTREM2 against amyloid pathology and related toxicity and suggests that increasing sTREM2 can be explored for AD therapy.Research by the authors was supported by grants from the National Natural Science Foundation of China 81370459, 31400914 (to X.C.), 81701079 (to L.Z.), 81373999, 81774377 (to L.W.), and 81601227 (to R.Z.), grants from the Natural Science Foundation of Guangdong Province 2016A030306005 (to X.C.), 2016A030310371 (to R.Z.), grants from the Fundamental Research Funds for the Central Universities 20720180055 (to X.C.), grants from the Alzheimer's Association AARG-18-56635 (to X.C.), and C4C-15-369446 (to H.X.). NIH grants RF1AG056130 (to G.B. and H.X.), R01AG035355 (to G.B.), R37AG027924 (to G.B.), and RF1AG056114 (to H.X.), grants from the Postdoctoral Science Foundation of China 2016M600503 and 2017T100469 (to L.Z.), a grant from the Tanz Family Funds (to H.X.), and a grant from the Natural Science Foundation of Fujian Province 2016J05203 (to R.Z.).该工作得到国家自然科学基金、厦门大学校长基金、广东省自然科学杰出青年基金、美国阿尔茨海默氏症协会基金和中国博士后科学基金等的资助
A novel muscarinic antagonist R2HBJJ inhibits non-small cell lung cancer cell growth and arrests the cell cycle in G0/G1.
Lung cancers express the cholinergic autocrine loop, which facilitates the progression of cancer cells. The antagonists of mAChRs have been demonstrated to depress the growth of small cell lung cancers (SCLCs). In this study we intended to investigate the growth inhibitory effect of R2HBJJ, a novel muscarinic antagonist, on non-small cell lung cancer (NSCLC) cells and the possible mechanisms. The competitive binding assay revealed that R2HBJJ had a high affinity to M3 and M1 AChRs. R2HBJJ presented a strong anticholinergic activity on carbachol-induced contraction of guinea-pig trachea. R2HBJJ markedly suppressed the growth of NSCLC cells, such as H1299, H460 and H157. In H1299 cells, both R2HBJJ and its leading compound R2-PHC displayed significant anti-proliferative activity as M3 receptor antagonist darifenacin. Exogenous replenish of ACh could attenuate R2HBJJ-induced growth inhibition. Silencing M3 receptor or ChAT by specific-siRNAs resulted in a growth inhibition of 55.5% and 37.9% on H1299 cells 96 h post transfection, respectively. Further studies revealed that treatment with R2HBJJ arrested the cell cycle in G0/G1 by down-regulation of cyclin D1-CDK4/6-Rb. Therefore, the current study reveals that NSCLC cells express an autocrine and paracrine cholinergic system which stimulates the growth of NSCLC cells. R2HBJJ, as a novel mAChRs antagonist, can block the local cholinergic loop by antagonizing predominantly M3 receptors and inhibit NSCLC cell growth, which suggest that M3 receptor antagonist might be a potential chemotherapeutic regimen for NSCLC
R2HBJJ down-regulated the levels of cell cycle regulatory proteins and Rb phosphorylation.
<p>H1299 cells were treated with 20 µM R2HBJJ for the indicated times (3–60 h, A) or with various concentrations of R2HBJJ (1.25–20 µM) for 48 h (B). Cell lysates were then subjected to western blot analysis. β-actin was used as the loading control.</p
Structures of R2HBJJ and its parental compounds.
<p>Structures of R2HBJJ and its parental compounds.</p
Exogenous replenish of ACh attenuated R2HBJJ-induced growth inhibition in H1299 cells (cell viability %, mean ± SD, n = 3).
<p>Two-way ANOVA was used to compare the interaction of two treatment factors. Post-hoc analyses were performed with Bonferroni's tests.</p>**<p><i>P</i><0.01, compared with the cells treated with 10 µM R2HBJJ alone.</p>#<p><i>P</i><0.05,</p>##<p><i>P</i><0.01, compared with the cells treated with 20 µM R2HBJJ alone.</p
mRNA expressions of cholinergic receptors and choline acetyltransferase in NSCLC cell lines.
<p>RT-PCR was performed on total RNA prepared from the indicated cell lines. Primers were described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0053170#pone-0053170-t003" target="_blank">Table 3</a>. GAPDH was used as loading control.</p
Selective effects of R2HBJJ on muscarinic acetylcholine receptor subtypes (mol/L, mean ± SD, n = 3).
<p>Selective effects of R2HBJJ on muscarinic acetylcholine receptor subtypes (mol/L, mean ± SD, n = 3).</p
R2HBJJ inhibited the contractile response induced by carbachol in guinea-pig tracheal strip.
<p>Carbachol (1 µM) was used to induce contractile response. After that, the indicated concentrations of R2HBJJ or atropine were added cumulatively into the organ bath and the inhibitory concentration responses against carbachol-induced contraction were obtained. The values were expressed as percentages of the maximum contractile response in the absence of any antagonist. Each point represented the mean ± SD of five independent experiments.</p