The pathological processes underlying Parkinson's disease (PD) involve more than dopamine cell loss within the midbrain. These non-dopaminergic neurotransmitters include noradrenergic, serotonergic, ...glutamatergic, and cholinergic systems within cortical, brainstem and basal ganglia regions. Several non-dopaminergic treatments are now in clinical use to treat motor symptoms of PD, or are being evaluated as potential therapies. Agents for symptomatic monotherapy and as adjunct to dopaminergic therapies for motor symptoms include adenosine A2A antagonists and the mixed monoamine-B inhibitor (MAO-BI) and glutamate release agent safinamide. The largest area of potential use for non-dopaminergic drugs is as add-on therapy for motor fluctuations. Thus adenosine A2A antagonists, safinamide, and the antiepileptic agent zonisamide can extend the duration of action of levodopa. To reduce levodopa-induced dyskinesia, drugs that target overactive glutamatergic neurotransmission can be used, and include the non-selective N-methyl D-aspartate antagonist amantadine. More recently, selective metabotropic glutamate receptor (mGluR₅) antagonists are being evaluated in phase II randomized controlled trials. Serotonergic agents acting as 5-HT2A/2C antagonists, such as the atypical antipsychotic clozapine, may also reduce dyskinesia. 5-HT1A agonists theoretically can reduce dyskinesia, but in practice, may also worsen PD motor symptoms, and so clinical applicability has not yet been shown. Noradrenergic α2A antagonism using fipamezole can potentially reduce dyskinesia. Several non-dopaminergic agents have also been investigated to reduce non-levodopa-responsive motor symptoms such as gait and tremor. Thus the cholinesterase inhibitor donepezil showed mild benefit in gait, while the predominantly noradrenergic re-uptake inhibitor methylphenidate had conflicting results in advanced PD subjects. Tremor in PD may respond to muscarinic M4 cholinergic antagonists (anticholinergics), but tolerability is often poor. Alternatives include β-adrenergic antagonists such as propranolol. Other options include 5-HT2A antagonists, and drugs that have mixed binding properties involving serotonin and acetylcholine, such as clozapine and the antidepressant mirtazapine, can be effective in reducing PD tremor. Many other non-dopaminergic agents are in preclinical and phase I/II early stages of study, and the reader is directed to recent reviews. While levodopa remains the most effective agent to treat motor symptoms in PD, the overall approach to using non-dopaminergic drugs in PD is to reduce reliance on levodopa and to target non-levodopa-responsive symptoms.
Paraspeckles are nuclear condensates, or membranelees organelles, that are built on the long noncoding RNA, NEAT1, and have been linked to many diseases. Although originally described as constitutive ...structures, here, in reviewing this field, we develop the hypothesis that cells increase paraspeckle abundance as part of a general stress response, to aid pro‐survival pathways. Paraspeckles increase in many scenarios: when cells transform from one state to another, become infected with viruses and bacteria, begin to degenerate, under inflammation, in aging, and in cancer. Cells increase paraspeckles by increasing transcription of NEAT1 and adjusting its RNA processing. These increases in NEAT1 are driven by numerous stress‐sensing signaling pathways, including signaling to mitochondria and stress granules, revealing crosstalk between the cytoplasm and nucleoplasm in the stress response. Thus, paraspeckles are an important piece of the puzzle in cellular homeostasis, and could be considered RNA‐scaffolded nuclear equivalents of dynamic stress‐induced structures that form in the cytoplasm. We speculate that, in general, cells rely on phase‐separated paraspeckles to transiently tweak gene regulation in times of cellular flux.
Paraspeckles are phase‐separated nuclear condensates that aid pro‐survival pathways in cellular stress and disease contexts such as cancer, viral infection, and neurodegeneration. Upregulation of the lncRNA NEAT1_2 in response to cellular stress increases paraspeckle abundance, transiently tweaking gene regulation via sequestration of proteins such as SFPQ, NONO and FUS.
Levodopa‐induced dyskinesia is a common complication in Parkinson disease. Pathogenic mechanisms include phasic stimulation of dopamine receptors, nonphysiological levodopa‐to‐dopamine conversion in ...serotonergic neurons, hyperactivity of corticostriatal glutamatergic transmission, and overstimulation of nicotinic acetylcholine receptors on dopamine‐releasing axons. Delay in initiating levodopa is no longer recommended, as dyskinesia development is a function of disease duration rather than cumulative levodopa exposure. We review current and in‐development treatments for peak‐dose dyskinesia but suggest that improvements in levodopa delivery alone may reduce its future prevalence. Ann Neurol 2018;84:797–811
Suppressor of cytokine signaling (SOCS) proteins are feedback inhibitors of the JAK/STAT pathway. SOCS3 has a crucial role in inhibiting STAT3 activation, cytokine signaling, and inflammatory gene ...expression in macrophages/microglia. To determine the role of SOCS3 in myeloid cells in neuroinflammation, mice with conditional SOCS3 deletion in myeloid cells (LysMCre-SOCS3fl/fl) were tested for experimental autoimmune encephalomyelitis (EAE). The myeloid-specific SOCS3-deficient mice are vulnerable to myelin oligodendrocyte glycoprotein (MOG)-induced EAE, with a severe, nonresolving atypical form of disease. In vivo, enhanced infiltration of inflammatory cells and demyelination is prominent in the cerebellum of myeloid-specific SOCS3-deficient mice, as is enhanced STAT3 signaling and expression of inflammatory cytokines/chemokines and an immune response dominated by Th1 and Th17 cells. In vitro, SOCS3-deficient macrophages exhibit heightened STAT3 activation and are polarized toward the classical M1 phenotype. SOCS3-deficient M1 macrophages provide the microenvironment to polarize Th1 and Th17 cells and induce neuronal death. Furthermore, adoptive transfer of M2 macrophages into myeloid SOCS3-deficient mice leads to delayed onset and reduced severity of atypical EAE by decreasing STAT3 activation, Th1/Th17 cells, and proinflammatory mediators in the cerebellum. These findings indicate that myeloid cell SOCS3 provides protection from EAE through deactivation of neuroinflammatory responses.
Nuclear proteins are often given a concise title that captures their function, such as 'transcription factor,' 'polymerase' or 'nuclear-receptor.' However, for members of the Drosophila ...behavior/human splicing (DBHS) protein family, no such clean-cut title exists. DBHS proteins are frequently identified engaging in almost every step of gene regulation, including but not limited to, transcriptional regulation, RNA processing and transport, and DNA repair. Herein, we present a coherent picture of DBHS proteins, integrating recent structural insights on dimerization, nucleic acid binding modalities and oligomerization propensity with biological function. The emerging paradigm describes a family of dynamic proteins mediating a wide range of protein-protein and protein-nucleic acid interactions, on the whole acting as a multipurpose molecular scaffold. Overall, significant steps toward appreciating the role of DBHS proteins have been made, but we are only beginning to understand the complexity and broader importance of this family in cellular biology.
The National Kidney Foundation–Kidney Disease Outcomes Quality Initiative (NKF-KDOQI) guideline for evaluation, classification, and stratification of chronic kidney disease (CKD) was published in ...2002. The KDOQI guideline was well accepted by the medical and public health communities, but concerns and criticisms arose as new evidence became available since the publication of the original guidelines. KDIGO (Kidney Disease: Improving Global Outcomes) recently published an updated guideline to clarify the definition and classification of CKD and to update recommendations for the evaluation and management of individuals with CKD based on new evidence published since 2002. The primary recommendations were to retain the current definition of CKD based on decreased glomerular filtration rate or markers of kidney damage for 3 months or more and to include the cause of kidney disease and level of albuminuria, as well as level of glomerular filtration rate, for CKD classification. NKF-KDOQI convened a work group to write a commentary on the KDIGO guideline in order to assist US practitioners in interpreting the KDIGO guideline and determining its applicability within their own practices. Overall, the commentary work group agreed with most of the recommendations contained in the KDIGO guidelines, particularly the recommendations regarding the definition and classification of CKD. However, there were some concerns about incorporating the cause of disease into CKD classification, in addition to certain recommendations for evaluation and management.
The unique ecology of human predators Darimont, Chris T.; Fox, Caroline H.; Bryan, Heather M. ...
Science (American Association for the Advancement of Science),
08/2015, Letnik:
349, Številka:
6250
Journal Article
Recenzirano
Paradigms of sustainable exploitation focus on population dynamics of prey and yields to humanity but ignore the behavior of humans as predators. We compared patterns of predation by contemporary ...hunters and fishers with those of other predators that compete over shared prey (terrestrial mammals and marine fishes). Our global survey (2125 estimates of annual finite exploitation rate) revealed that humans kill adult prey, the reproductive capital of populations, at much higher median rates than other predators (up to 14 times higher), with particularly intense exploitation of terrestrial carnivores and fishes. Given this competitive dominance, impacts on predators, and other unique predatory behavior, we suggest that humans function as an unsustainable "super predator," which—unless additionally constrained by managers—will continue to alter ecological and evolutionary processes globally.
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