Parkinson's disease (PD), primarily caused by selective degeneration of midbrain dopamine (mDA) neurons, is the most prevalent movement disorder, affecting 1-2% of the global population over the age of 65. Currently available pharmacological treatments are largely symptomatic and lose their efficacy over time with accompanying severe side effects such as dyskinesia. Thus, there is an unmet clinical need to develop mechanism-based and/or diseasemodifying treatments. Based on the unique dual role of the nuclear orphan receptor Nurr1 for development and maintenance of mDA neurons and their protection from inflammation-induced death, we hypothesize that Nurr1 can be a molecular target for neuroprotective therapeutic development for PD. Here we show successful identification of Nurr1 agonists sharing an identical chemical scaffold, 4-amino-7-chloroquinoline, suggesting a critical structure-activity relationship. In particular, we found that two antimalarial drugs, amodiaquine and chloroquine stimulate the transcriptional function of Nurr1 through physical interaction with its ligand binding domain (LBD). Remarkably, these compounds were able to enhance the contrasting dual functions of Nurr1 by further increasing transcriptional activation of mDA-specific genes and further enhancing transrepression of neurotoxic proinflammatory gene expression in microglia. Importantly, these compounds significantly improved behavioral deficits in 6-hydroxydopamine lesioned rat model of PD without any detectable signs of dyskinesia-like behavior. These findings offer proof of principle that small molecules targeting the Nurr1 LBD can be used as a mechanismbased and neuroprotective strategy for PD.P D is primarily caused by selective degeneration of midbrain dopamine (mDA) neurons and is the most prevalent movement disorder, affecting 1-2% of the global population over the age of 65 (1-3). Currently available pharmacological treatments [e.g., L-3,4-dihydroxyphenylalanine (L-DOPA)] are largely symptomatic and lose their efficacy over time, with accompanying severe side effects such as dyskinesia. Thus, there is an unmet clinical need to develop mechanism-based and/or disease-modifying treatments (2, 3).During the last two decades, many intrinsic signals and extrinsic transcription factors have been identified to play critical roles for mDA neuron development (4-6). In particular, development of mDA neurons is dependent on two major signaling molecules, Sonic hedgehog (Shh) and wingless-type MMTV integration site family, member 1 (Wnt1), and their downstream factors. These two critical pathways (i.e., Shh-FoxA2 and Wnt1-Lmx1a) merge to control the expression of the orphan nuclear receptor related 1 protein (Nurr1) (7), suggesting that Nurr1 is a key regulator of mDA neurons. Indeed, Nurr1 [also known as nuclear receptor subfamily 4, group A, member 2 (NR4A2)] is essential not only for development (8-10) but also for maintenance of mDA neurons in adult brains (11). In addition, a recent study demonstrated that Nurr1 plays critical roles ...
The functional roles of the orphan nuclear receptor, Nurr1, have been extensively studied and well established in the development and survival of midbrain dopamine neurons. Since Nurr1 and other NR4A members are widely expressed in the brain in overlapping and distinct manners, it has been an open question whether Nurr1 has important function(s) in other brain areas. Recent studies suggest that up-regulation of Nurr1 expression is critical for cognitive functions and/or long-term memory in forebrain areas including hippocampal formation. Questions remain about the association between Nurr1 expression and Alzheimer’s disease (AD) brain pathology. Here, using our newly developed Nurr1-selective antibody, we report that Nurr1 protein is prominently expressed in brain areas with Aβ accumulation, i.e., the subiculum and the frontal cortex, in the 5XFAD mouse and that Nurr1 is highly co-expressed with Aβ at early stages. Furthermore, the number of Nurr1-expressing cells significantly declines in the 5XFAD mouse in an age-dependent manner, accompanied by increased plaque deposition. Thus, our findings suggest that altered expression of Nurr1 is associated with AD progression.
Although peripheral artery disease (PAD) is a major health problem, there have been limited advances in medical therapies. In PAD patients, angiogenesis is regarded as a promising therapeutic strategy to promote new arterial vessels and improve perfusion of ischemic tissue. Autophagy plays a critical role in catabolic processes for cell survival under normal and stressful conditions and plays fundamental biological roles in various cellular functions. In the present study, we showed that autophagy in endothelial cells is important for the repair and regeneration of damaged tissues. In a hindlimb ischemia mouse model, autophagy was stimulated in endothelial cells of the quadriceps muscle, and adjacent cells proliferated and regenerated. The autophagy pathway was induced under prolonged hypoxia in endothelial cells, and autophagy increased angiogenic activities. Moreover, conditioned media from endothelial cells blocked autophagy and inhibited the proliferation of muscle cells, suggesting that autophagic stimulation in endothelial cells affects the survival of adjacent cells, such as muscle. Collectively, hypoxia/ischemia-induced autophagy angiogenesis, and the damaged tissue surrounded by neo-vessels was regenerated in an ischemia model. Therefore, we strongly suggest that stimulation of autophagy in endothelial cells may be a potent therapeutic strategy in severe vascular diseases, including PAD.
Receptor tyrosine kinase MET (c-MET) has received considerable attention as a potential target for gastric cancer (GC) therapy and a number of c-MET inhibitors have been developed. For successful drug development, proper preclinical studies especially using patient derived cancer cell lines are very important. We profiled MET and MET-related characteristics in 49 GC cell lines to utilize them as models in preclinical studies of GC. Forty-nine cell lines were analyzed for genetic, biological, and molecular status to characterize MET and MET-related molecules. Four c-MET inhibitors were tested to elucidate the dependency on MET pathway in the 49 GC cell lines. Six of 49 cell lines were MET amplified with overexpression of c-MET and p-MET. The variants of MET were not associated with c-MET expression or amplification. Hs746T showed an exon 14 deletion in conjunction with MET amplification. The cell lines were divided into 6 MET amplified, 2 c-MET overexpressed, 2 hepatocyte growth factor (HGF) overexpressed, and 39 MET-negative subgroups. Except tivantinib, the c-MET inhibitors showed higher inhibition (%) in MET amplified than in MET nonamplified cell lines that MET amplified cell lines showed MET pathway dependency. However, the c-MET overexpressed and HGF overexpressed cell lines showed moderate dependency on MET pathway. Well-characterized cell lines are very important in studying drug development. Our 49 GC cell lines had various characteristics of MET and MET-related molecules and MET pathway dependency. These provide a promising platform for development of various RTK inhibitors including c-MET inhibitors.
Dairy products are major sources of conjugated linoleic acid (CLA); thus, an increase in CLA content can improve the quality value of dairy products. The objective of this work was to determine the effects of lactation time, feeding regimen, and ripening period on the level of CLA in processed cheese. CLA content in milk varied with the period of lactation; high in spring (April and May, about 6.8 mg CLA/g fat) and relatively low in mid summer and winter (about 4.3 mg CLA/g fat). The effects of dietary regimen and ripening period were determined in milk, which was obtained from March to May. After aging for 4 months, the cheese made from milk obtained from cows fed on pasture contained relatively higher levels of CLA compared to cheese made from milk obtained from cows fed indoors (8.12 mg CLA/g fat vs 6.76 mg CLA/g fat), but there was no difference in 7 month-aged cheeses. In both pasture and indoor feeding, 7 month-aged cheeses showed higher CLA content than 4 month-aged cheeses. The contents of stearic acid (C18:0) and linolenic acid (C18:3) were significantly higher in cheese from pasture fed cows compared to those in cows fed indoors. These findings should be helpful for the efficient production of functional dairy products with high CLA contents.
Some non-antiarrhythmic drugs have the undesirable property of delaying cardiac repolarization, an effect that can be measured empirically as a prolongation of the QT interval by surface electrocardiogram (ECG). The QT prolongation and proarrhythmia potential of famotidine are largely unknown, particularly in individuals that have cardiovascular risk factors such as abnormal electrolyte levels. Based on an analysis of QT/QTc intervals from a database of ECG recordings from a large Korean population (ECG-ViEW, 710,369 ECG recordings from 371,401 individuals), we observed that famotidine administration induced a prolonged QTc interval (above 480 ms, p < 0.05 compared to before-treatment, based on a McNemar test). Furthermore, famotidine induced QT prolongations in 10 out of 14 patients with hypocalcemia and 11 out of 13 patients with hypomagnesemia [difference of mean between before and after famotidine administration; 38.00 ms (95% confidence interval 2.72-73.28) and 67.08 ms (95% confidence interval 24.94-109.21), p < 0.05 and p < 0.01 by paired t test, respectively]. In vitro, the IC50 of famotidine for human-ether-a-go-go gene (hERG) channel inhibition was higher than 100 μM as determined by automated patch clamp hERG current assay, implying that hERG channel inhibition is not the underlying mechanism for QT prolongation. These results suggest that famotidine administration increases a proarrhythmic potential, especially in subjects with electrolytes imbalance.
Background/Aim: Casein kinase 2 (CK2) is involved in multiple cellular processes. Furthermore, its overexpression in several human cancers has been associated with tumor progression. In this study, we evaluated the efficacy of the CK2 inhibitor, CX-4945, in gastric cancer cell lines and explored the potential predictive biomarkers for CX-4945 sensitivity. Materials and Methods: The sensitivity to CX-4945 was screened in 49 gastric cancer cell lines by the MTT assay. The mRNA and protein expression of CK2 subunits (α and α') were determined using qRT-PCR and western blot. Furthermore, the activity of CK2α was measured by ELISA. Gene expression and mutations were analyzed via whole-exome and RNA sequencing. Results: The sensitivity to CX-4945 was determined by the inhibition rate (%) at the effective dose (10 μM) which ranged from-1% to 89% in 49 gastric cancer cell lines. CK2α', but not CK2α, mRNA expression was correlated with CX-4945 sensitivity. Conclusion: In this study, CX-4945 showed modest antitumor efficacy in gastric cancer cell lines. CK2 might represent a potential therapeutic target for gastric cancer. Gastric cancer is the most commonly diagnosed cancer in Korea and increased annual screenings indicated that the proportion of early gastric cancer increased to 73.6% of all cancer cases (1). Based on a Korea National Cancer Incidence Database (KNCI DB), gastric cancer is the second (15.2%) and third (9.5%) highest in males and females, respectively. Also, gastric cancer recorded as the forth (9.2%) and sixth (7.9%) highest cause of death in males and females, respectively (2). In America and Europe gastric cancer burden remains high (3). Several agents have been developed to treat metastatic gastric cancer including those targeting the epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), vascular endothelial growth factor (VEGF) and hepatocyte growth factor receptor (HGFR/C-Met). However, except for trastuzumab and ramucirumab, most of them have failed to show efficacy in gastric cancer (4-6). A comprehensive understanding of gastric cancer biology is needed for new drug development (7, 8). Casein kinase 2 (CK2) is a serine/threonine kinase that is a tetramer of two catalytic subunits α and α', and a regulatory subunit β. CK2 plays a critical role in multiple cellular processes such as DNA repair, maintenance of cell viability, protection of cells from apoptosis, and cell-cycle regulation (9, 10). Dysregulation of CK2 plays an important role in cancer progression via regulation of signal transduction pathways, including PI3K/AKT and the MAPK pathway (11, 12). CK2α phosphorylates p53/p21 and increases C-myc, which regulates tumor progression. Furthermore, CK2α overexpression is associated with epithelial-mesenchymal transition (EMT) (13). CK2 overexpression is also correlated with poor prognosis in various cancer types (14, 15). In gastric 6171
ObjectiveIncreased atrial size is frequently seen in ischemic stroke patients in clinical practice. There is controversy about whether left atrial enlargement (LAE) should be regarded as a risk factor for cerebral infarction. We investigated the association between indexed left atrial volume (LAVI) and conventional stroke risk factors as well as stroke subtypes in acute ischemic stroke patients.MethodsOne hundred eighty two acute cerebral infarction patients were included in this study. Brain magnetic resonance imaging and transthoracic echocardiography were done for all patients within 30 days of diagnosis of acute cerebral infarction. Echocardiographic LAE was identified when LAVI was more than 27 mL/m2. Stroke subtypes were classified by the Trial of Org 10171 in acute stroke treatment classification.ResultsThere were significant differences between subjects with normal and increased LAVI in prevalence of stroke risk factors including atrial fibrillation (p = 0.001), hypertension (p = 0.000), valvular heart disease (p = 0.011) and previous stroke (p = 0.031). An increased LAVI was associated with cardioembolic subtype with an adjusted odds ratio was 6.749 (p = 0.002) compared with small vessel disease.ConclusionIncreased LAVI was more prevalent in those who had cardiovascular risk factors, such as atrial fibrillation, hypertension, valvular heart disease and history of previous stroke. LAE influenced most patients in all subtypes of ischemic stroke but was most prevalent in the cardioembolic stroke subtype. Increased LAVI might be a risk factor of cerebral infarction, especially in patients with cardioembolic stroke subtype.
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