Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are the most common genetic cause of familial and sporadic Parkinson's disease (PD). That the most prevalent mutation, G2019S, leads to increased kinase activity has led to a concerted effort to identify LRRK2 kinase inhibitors as a potential disease-modifying therapy for PD. An internal medicinal chemistry effort identified several potent and highly selective compounds with favorable drug-like properties. Here, we characterize the pharmacological properties of cis-2,6-dimethyl-4-(6-(5-(1-methylcyclopropoxy)-1H-indazol-3-yl)pyrimidin-4-yl)morpholine (MLi-2), a structurally novel, highly potent, and selective LRRK2 kinase inhibitor with central nervous system activity. MLi-2 exhibits exceptional potency in a purified LRRK2 kinase assay in vitro (IC 50 5 0.76 nM), a cellular assay monitoring dephosphorylation of LRRK2 pSer935 LRRK2 (IC 50 5 1.4 nM), and a radioligand competition binding assay (IC 50 5 3.4 nM). MLi-2 has greater than 295-fold selectivity for over 300 kinases in addition to a diverse panel of receptors and ion channels. Acute oral and subchronic dosing in MLi-2 mice resulted in dosedependent central and peripheral target inhibition over a 24-hour period as measured by dephosphorylation of pSer935 LRRK2. Treatment of MitoPark mice with MLi-2 was well tolerated over a 15-week period at brain and plasma exposures .100Â the in vivo plasma IC 50 for LRRK2 kinase inhibition as measured by pSer935 dephosphorylation. Morphologic changes in the lung, consistent with enlarged type II pneumocytes, were observed in MLi-2-treated MitoPark mice. These data demonstrate the suitability of MLi-2 as a compound to explore LRRK2 biology in cellular and animal models.
P2Y receptors are a class of G protein-coupled receptors activated primarily by ATP, UTP, and UDP. Five mammalian P2Y receptors have been cloned so far including P2Y1, P2Y2, P2Y4, P2Y6, and P2Y11. P2Y1, P2Y2, and P2Y6 couple to the activation of phospholipase C, whereas P2Y4 and P2Y11 couple to the activation of both phospholipase C and the adenylyl cyclase pathways. Additional ADP receptors linked to G␣ i have been described but have not yet been cloned. SP1999 is an orphan G protein-coupled receptor, which is highly expressed in brain, spinal cord, and blood platelets. In the present study, we demonstrate that SP1999 is a G␣ icoupled receptor that is potently activated by ADP. In an effort to identify ligands for SP1999, fractionated rat spinal cord extracts were assayed for Ca 2؉ mobilization activity against Chinese hamster ovary cells transiently transfected with SP1999 and chimeric G␣ subunits (G␣ q/i ). A substance that selectively activated SP1999-transfected cells was identified and purified through a series of chromatographic steps. Mass spectral analysis of the purified material definitively identified it as ADP. ADP was subsequently shown to inhibit forskolin-stimulated adenylyl cyclase activity through selective activation of SP1999 with an EC 50 of 60 nM. Other nucleotides were able to activate SP1999 with a rank order of potency 2-MeS-ATP ؍ 2-MeS-ADP > ADP ؍ adenosine 5-O-2-(thio-)diphosphate > 2-Cl-ATP > adenosine 5-O-(thiotriphosphate). Thus, SP1999 is a novel, G␣ i -linked receptor for ADP.Purine and pyrimidine nucleotides are known to modulate a variety of physiological functions by interaction with two types of cell surface receptors: P2X and P2Y receptors (1, 2). P2X receptors are ligand-gated ion-channels, whereas P2Y receptors are G protein-coupled receptors (GPCRs).
Although obesity and physical activity have been argued to predict back pain, these factors are also related to incontinence and breathing difficulties. Breathing and continence mechanisms may interfere with the physiology of spinal control, and may provide a link to back pain. The aim of this study was to establish the association between back pain and disorders of continence and respiration in women. We conducted a cross-sectional analysis of self-report, postal survey data from the Australian Longitudinal Study on Women's Health. We used multinomial logistic regression to model four levels of back pain in relation to both the traditional risk factors of body mass index and activity level, and the potential risk factors of incontinence, breathing difficulties, and allergy. A total of 38,050 women were included from three age-cohorts. When incontinence and breathing difficulties were considered, obesity and physical activity were not consistently associated with back pain. In contrast, odds ratios (OR) for often having back pain were higher for women often having incontinence compared to women without incontinence (OR were 2.5, 2.3 and 2.3 for young, mid-age and older women, respectively). Similarly, mid-aged and older women had higher odds of having back pain often when they experienced breathing difficulties often compared to women with no breathing problems (OR of 2.0 and 1.9, respectively). Unlike obesity and physical activity, disorders of continence and respiration were strongly related to frequent back pain. This relationship may be explained by physiological limitations of co-ordination of postural, respiratory and continence functions of trunk muscles.
It is hoped that the results of this study will help increase and facilitate the discussions regarding end-of-life care in emergency departments. Realistic initial implications include finding ways to decrease workloads of emergency nurses and increase direct patient care. Another important implication would be the improvement of ED designs. Further research in the area of end-of-life care in emergency settings is recommended.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.