Mutations in LRRK2 are thus far the most frequent known cause of autosomal dominant and idiopathic Parkinson’s disease (PD) with prevalent mutations being found within the GTPase (R1441C/G) and kinase (G2019S) domains. Previous in vitro studies have revealed that R1441C and G2019S mutations are associated with increased kinase activity. To better understand LRRK2-linked PD pathogenesis in vivo, we have generated transgenic C. elegans overexpressing human LRRK2 wild type, R1441C and G2019S in dopaminergic (DA) neurons. Overexpression of these LRRK2 proteins causes age-dependent DA neurodegeneration, behavioral deficits, and locomotor dysfunction that are accompanied by a reduction of dopamine levels in vivo. In comparison, R1441C and G2019S mutants cause more severe phenotypes than the wild type protein. Interestingly, treatment with exogenous dopamine rescues the LRRK2-induced behavioral and locomotor phenotypes. In contrast, expression of the GTP binding defective mutant, K1347A, or knockout of the C. elegans LRRK2 homolog, LRK-1, prevents the LRRK2-induced neurodegeneration and behavioral abnormalities. Hence, our transgenic LRRK2 C. elegans models recapitulate key features of PD including progressive neurodegeneration, impairment of dopamine-dependent behavior and locomotor function, and reduction in dopamine levels. Furthermore, our findings provide strong support for the critical role of GTPase/kinase activity in LRRK2-linked pathologies. These invertebrate models will be useful for studying pathogenesis of PD and for development of potential therapeutics for the disease.
The intelligent vehicle is a complicated nonlinear system, and the design of a path tracking controller is one of the key technologies in intelligent vehicle research. This paper mainly designs a lateral control dynamic model of the intelligent vehicle, which is used for lateral tracking control. Firstly, the vehicle dynamics model (i.e., transfer function) is established according to the vehicle parameters. Secondly, according to the vehicle steering control system and the CARMA (Controlled Auto-Regression and Moving-Average) model, a second-order control system model is built. Using forgetting factor recursive least square estimation (FFRLS), the system parameters are identified. Finally, a neural network PID (Proportion Integral Derivative) controller is established for lateral path tracking control based on the vehicle model and the steering system model. Experimental simulation results show that the proposed model and algorithm have the high real-time and robustness in path tracing control. This provides a certain theoretical basis for intelligent vehicle autonomous navigation tracking control, and lays the foundation for the vertical and lateral coupling control.
To investigate the role of miRNA in controlling human embryonic stem (hES) cell differentiation toward the endothelial lineage and chick embryonic blood vessel formation, undifferentiated hES cells were first cultured on Matrigelcoated flasks and in endothelial cell growth medium-2 (EGM-2) to initiate endothelial cell (EC) differentiation.
Objective-Smooth muscle cell (SMC) migration and proliferation play an essential role in neointimal formation after vascular injury. In this study, we intended to investigate whether the X-box-binding protein 1 (XBP1) was involved in these processes. Approach and Results-In vivo studies on femoral artery injury models revealed that vascular injury triggered an immediate upregulation of XBP1 expression and splicing in vascular SMCs and that XBP1 deficiency in SMCs significantly abrogated neointimal formation in the injured vessels. In vitro studies indicated that platelet-derived growth factor-BB triggered XBP1 splicing in SMCs via the interaction between platelet-derived growth factor receptor β and the inositolrequiring enzyme 1α. The spliced XBP1 (XBP1s) increased SMC migration via PI3K/Akt activation and proliferation via downregulating calponin h1 (CNN1). XBP1s directed the transcription of mir-1274B that targeted CNN1 mRNA degradation. Proteomic analysis of culture media revealed that XBP1s decreased transforming growth factor (TGF)-β family proteins secretion via transcriptional suppression. TGF-β3 but not TGF-β1 or TGF-β2 attenuated XBP1s-induced CNN1 decrease and SMC proliferation. Conclusions-This study demonstrates for the first time that XBP1 is crucial for SMC proliferation via modulating the platelet-derived growth factor/TGF-β pathways, leading to neointimal formation. under stress conditions. [21][22][23] Under ER stress conditions, XBP1 mRNA undergoes unconventional splicing through an ER-resident kinase that possesses ribonuclease activity, the inositol-requiring enzyme 1 α (IRE1α). 24 Our recent studies and reports from other groups showed that physiological stimuli such as vascular endothelial cell growth factor could trigger XBP1 splicing in an ER stress response-independent manner. [25][26][27][28] In endothelial cells (ECs), XBP1 splicing plays diverse roles, including cell proliferation, 26 autophagy response, 29 and apoptosis. 30 In SMCs, bone morphogenetic protein-2 was reported to activate XBP1 splicing, 31 but the exact role of XBP1 in SMCs still remains unclear. In this study, we demonstrated that XBP1 splicing is crucial in PDGF-BB-induced SMC proliferation and contributes to neointima formation after vascular injury. Materials and MethodsMaterials and Methods are available in the online-only Data Supplement. Results Vascular Injury Increased XBP1 Expression and SplicingIn response to vascular injury, vascular SMCs will be activated undergoing migration, proliferation, and apoptosis. 32 To test whether XBP1 was involved in SMC activation, femoral artery injury model was introduced into the right side of C57Bl/6 mice. The injured vessels were harvested at day 1, and day 3 post surgery, whereas the left uninjured vessels were collected as control. Double immunofluorescence staining with anti-α SMC actin and antispliced XBP1 (XBP1s) or unspliced XBP1 (XBP1u) antibodies were performed on the cryo-sections. As shown in Figure 1A, low levels of XBP1s and XBP1u were detected in the uninjure...
Increasing evidence suggests that ion channel genes play an important role in the progression of gliomas. However, the mechanisms by which ion channel genes influence the progression of glioma are not fully understood. We identified KCNB1 as a novel ion gene, associated with malignant progression and favorable overall survival (OS) and progression-free survival (PFS) in glioma patients from three datasets (CGGA, GSE16011 and REMBRANDT). Moreover, we characterized a novel function of autophagy induction accompanied by increased apoptosis and reduced proliferation and invasion of glioma cells for KCNB1. KEGG pathway analysis and in vitro studies suggested that the ERK pathway is involved in KCNB1-mediated regulation of autophagy, which was confirmed by inhibition of KCNB1-induced autophagy by using a selective ERK1/2 inhibitor (U0126) or siERK1/2. In vivo studies showed that KCNB1 induced autophagy while inhibiting tumor growth and increasing survival. Overall, our studies define KCNB1 as a novel prognostic factor for gliomas that exerts its tumor suppressive function through autophagy induction.
CFTR channels conduct HCO(3)(-) in addition to Cl(-) in airway epithelial cells. A defective HCO(3)(-)-transporting function of CFTR may underlie the pathogenesis of cystic fibrosis. In the present study, we have investigated whether a HCO(3)(-)-sensitive soluble adenylyl cyclase (sAC) is functionally coupled with CFTR and thus forms an autoregulatory mechanism for HCO(3)(-) transport in human airway epithelial Calu-3 cells. A reverse transcriptase-polymerase chain reaction showed that transcripts of both full-length and truncated sACs are present in Calu-3 cells. Truncated sAC protein is the predominant, if not the only, isoform expressed in Calu-3 cells. HCO(3)(-) stimulated a modest increase in cAMP production, and the increase was sensitive to 2-hydroxyestradiol (2-HE), a sAC inhibitor, but not to SQ22,536, a blocker of conventional transmembrane adenylyl cyclases. These results suggest that sAC is functional in Calu-3 cells. Adding 25 mM HCO(3)(-) to the bath stimulated CFTR-mediated whole cell currents in the absence, but not in the presence, of 2-HE. In cell-attached membrane patches, 25 or 50 mM HCO(3)(-) in the bath markedly increased the product of channel number and open probability of CFTR, and this activation was attenuated by 2-HE. These findings demonstrate that sAC signaling pathway is involved in the regulation of CFTR function in human airway epithelium and thereby provides a link between the level of intracellular HCO(3)(-)/CO(2) and the modulation of HCO(3)(-)-conductive CFTR function by cAMP/PKA.
Purpose\ud Since the 2008 financial crisis, the UK workforce in general has experienced a period of stagnant and falling wages in both nominal and real terms. The main parties involved remain unsure of the consequences from such a historically unusual phenomenon. The purpose of this paper is twofold: first, to explore the main effect on job satisfaction and organizational commitment of those employees who had experienced pay reductions (nominal wage cuts or pay freezes under a positive inflation rate) as compared with those who experienced nominal pay rises during the recent recession; and second, to examine the moderating effect of employee involvement (EI) practices on that relationship. This was done by using aggregated employee perception data to measure organizational EI practices.\ud \ud Design/methodology/approach\ud Employee-employer matched data were used, involving 8,489 employees and their associated 497 organizations (medium or large sized). The number of employees from each organization was between 15 and 25. The data used were extracted from the 2011 Workplace Employment Relations Study in the UK to which the authors applied hierarchical linear regression in STATA 13.\ud \ud Findings\ud The results indicate that when compared with those employees who had nominal pay rises during the recession, employees who had wage cuts or freezes (with 5 percent inflation rate) are significantly and negatively associated with their job satisfaction and organizational commitment, even when controlling for important variables such as perception of job insecurity and the degree of adverse impact caused by recession on the organization studied. That is to say, facing the same perception of job loss, those who experienced pay reductions are significantly unhappier and less committed than those who had pay rises. However, the adverse effect of pay reductions on employees’ work attitudes is much less in workplaces characterized by a high, as opposed to a low level, of EI practices.\ud \ud Research limitations/implications\ud Implications, limitations, and further research issues are discussed in light of current employment relations’ practices.\ud \ud Originality/value\ud The intention is to extend the current debate on employment relations under adverse changes such as pay reductions. Thus, the unique contribution of this study is to examine the value of EI in modifying extreme employee reactions to adverse changes
This article examines the moderating effect of collective trust in management on the relation between job insecurity (both objective and subjective) and employee outcomes (work-related anxiety and organisational commitment). This is contextualized in the modern British workplace which has seen increased employment insecurity and widespread cynicism. We use matched employer-employee data extracted from the British Workplace Employment Relations Survey (WERS) 2011, which includes over 16,000 employees from more than 1,100 organizations. The multilevel analyses confirm that objective job insecurity (loss of important elements of a job such as cuts in pay, overtime, training, and working hours) are significantly correlated with high levels of work-related anxiety and lower levels of organizational commitment. These correlations are partially mediated by subjective job insecurity (perception of possible job loss). More importantly, collective trust in management (a consensus of management being reliable, honest and fair) significantly attenuates the negative impact of objective job insecurity on organizational commitment, and reduces the impact of subjective job insecurity on work-related anxiety. Theoretical and practical implications and limitations of these effects are discussed.
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