46 research outputs found

    Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

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    The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

    Suramin Is A Novel Competitive Antagonist Selective To α1β2γ2 Gaba A Over Ï1 Gaba C Receptors

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    GABA A and GABA C receptors are both GABA-gated chloride channels with distinct pharmacological properties, mainly in their sensitivity to bicuculline and gabazine. In this study, we found that suramin, a purinergic receptor antagonist, is a novel competitive antagonist selective to GABA A over GABA C receptors. Specifically, suramin antagonized the GABA-induced current and the spontaneous opening current of the wild type α1β2γ2 GABA A receptor with high-level expression in Xenopus oocytes. The antagonism was concentration dependent with an IC 50 that varied depending on the concentration of GABA, and with the lowest IC 50 of 0.43 μM when antagonizing the spontaneous current. Thus, its potency is slightly higher than bicuculline on the same GABA A receptor. Suramin also antagonized the mouse native brain GABA receptors micro-transplanted into the Xenopus oocytes with its potency depending on the GABA concentration. In addition, in the presence of two fixed concentrations of suramin, the GABA concentration response of the receptor was shifted to the right without reduction of the maximum current. Thus, our results are consistent with that suramin is a competitive antagonist for the α1β2γ2 GABA A receptor. Interestingly, the rank order of maximum allosteric inhibition (efficacy) of spontaneous current of the GABA A receptor by three competitive antagonists was suramin \u3e bicuculline \u3e gabazine, similar to the rank order of their molecular weight. In contrast, similar to bicuculline, suramin has much lower potency in antagonizing the GABA-induced current of the Ï1 GABA C receptor. In conclusion, we have identified a novel GABA A receptor competitive antagonist, which is selective to the α1β2γ2 over Ï1 GABA receptors

    Stroke-Induced Immunosuppression And Poststroke Infection

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    Infections occur commonly after stroke and are strongly associated with an unfavourable functional outcome of these patients. Approaches for effective management of poststroke infection remain scarce, presenting an urgent need for preventive anti-infection strategies for patients who have suffered a stroke. Emerging evidence indicates that stroke impairs systemic immune responses and increases the susceptibility to infections, suggesting that the modification of impaired immune defence could be beneficial. In this review, we summarised previous attempts to prevent poststroke infections using prophylactic antibiotics and the current understanding of stroke-induced immunosuppression. Further elucidation of the immune mechanisms of stroke will pave the way to tailored design of new treatment to combat poststroke infection via modifying the immune system

    Neuroprotective Effects Of Fingolimod In Mouse Models Of Parkinson\u27S Disease

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    Parkinson\u27s disease (PD) is characterized by a progressive loss of dopaminergic neurons with limited treatment options. Emerging evidence shows that FTY720 protects against neural injury via modulation of the sphingosine-1-phosphate 1 receptor (S1PR1). However, it remains unclear whether FTY720 could influence neurodegeneration in PD.Therefore, the present studywas designed to determine the impact of fingolimod (FTY720), a sphingosine-1-phosphate receptor (S1PR) agonist, on 2 mouse models of PD. We found that FTY720 significantly reduced the deficit of motor function, diminished the loss of tyrosine hydroxylase-positive neurons in the substantia nigra, and attenuated the decrease of striatal dopamine and metabolite levels in mice receiving 6-hydroxydopamine (6-OHDA) or rotenone to simulate PD. An S1PR1-selective antagonist, W146, blocked the neuroprotective effects of FTY720.Of note, FTY720 retained the phosphorylation of ERK, together with a decreased expressionof cleaved caspase-3 inmice treatedwith6-OHDAor rotenone. In vitro studies revealedthat FTY720 also attenuated 6-OHDA- or rotenone-induced toxicity in SH-SY5Y cells. These findings suggest the potential of S1PR modulation as a treatment for PD.-Zhao, P., Yang, X., Yang, L., Li, M., Wood, K., Liu, Q., Zhu, X. Neuroprotective effects of fingolimod in mouse models of Parkinson\u27s disease. FASEB J. 31, 172-179 (2017). www.fasebj.org

    IL (Interleukin)-15 Bridges Astrocyte-Microglia Crosstalk and Exacerbates Brain Injury Following Intracerebral Hemorrhage.

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    Background and Purpose- Microglia are among the first cells to respond to intracerebral hemorrhage (ICH), but the mechanisms that underlie their activity following ICH remain unclear. IL (interleukin)-15 is a proinflammatory cytokine that orchestrates homeostasis and the intensity of the immune response following central nervous system inflammatory events. The goal of this study was to investigate the role of IL-15 in ICH injury. Methods- Using brain slices of patients with ICH, we determined the presence and cellular source of IL-15. A transgenic mouse line with targeted expression of IL-15 in astrocytes was generated to determine the role of astrocytic IL-15 in ICH. The expression of IL-15 was controlled by a glial fibrillary acidic protein promoter (GFAP-IL-1

    Selective Nlrp3 (Pyrin Domain-Containing Protein 3) Inflammasome Inhibitor Reduces Brain Injury After Intracerebral Hemorrhage

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    Background and Purpose - Intracerebral hemorrhage (ICH) is a devastating disease without effective treatment. As a key component of the innate immune system, the NOD-like receptor (NLR) family, NLRP3 (pyrin domain-containing protein 3) inflammasome, when activated after ICH, promotes neuroinflammation and brain edema. MCC950 is a potent, selective, small-molecule NLRP3 inhibitor that blocks NLRP3 activation at nanomolar concentrations. Here, we examined the effect of MCC950 on brain injury and inflammation in 2 models of ICH in mice. Methods - In mice with ICH induced by injection of autologous blood or bacterial collagenase, we determined the therapeutic potential of MCC950 and its mechanisms of neuroprotection. Results - MCC950 reduced IL-1β (interleukin-1β) production and attenuated neurodeficits and perihematomal brain edema after ICH induction by injection of either autologous blood or collagenase. In mice with autologous blood-induced ICH, the protection of MCC950 was associated with reduced leukocyte infiltration into the brain and microglial production of IL-6. MCC950 improved blood-brain barrier integrity and diminished cell death. Notably, the protective effect of MCC950 was abolished in mice depleted of either microglia or Gr-1+ myeloid cells. Conclusions - These results indicate that the NLRP3 inflammasome inhibitor, MCC950, attenuates brain injury and inflammation after ICH. Hence, NLRP3 inflammasome inhibition is a potential therapy for ICH that warrants further investigation. Visual Overview - An online visual overview is available for this article

    A Translocator Protein 18 Kda Agonist Protects Against Cerebral Ischemia/Reperfusion Injury

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    Background: Cerebral ischemia is a leading cause of death and disability with limited treatment options. Although inflammatory and immune responses participate in ischemic brain injury, the molecular regulators of neuroinflammation after ischemia remain to be defined. Translocator protein 18 kDa (TSPO) mainly localized to the mitochondrial outer membrane is predominantly expressed in glia within the central nervous system during inflammatory conditions. This study investigated the effect of a TSPO agonist, etifoxine, on neuroinflammation and brain injury after ischemia/reperfusion. Methods: We used a mouse model of middle cerebral artery occlusion (MCAO) to examine the therapeutic potential and mechanisms of neuroprotection by etifoxine. Results: TSPO was upregulated in Iba1+ or CD11b+CD45int cells from mice subjected to MCAO and reperfusion. Etifoxine significantly attenuated neurodeficits and infarct volume after MCAO and reperfusion. The attenuation was pronounced in mice subjected to 30, 60, or 90 min MCAO. Etifoxine reduced production of pro-inflammatory factors in the ischemic brain. In addition, etifoxine treatment led to decreased expression of interleukin-1β, interleukin-6, tumor necrosis factor-α, and inducible nitric oxide synthase by microglia. Notably, the benefit of etifoxine against brain infarction was ablated in mice depleted of microglia using a colony-stimulating factor 1 receptor inhibitor. Conclusions: These findings indicate that the TSPO agonist, etifoxine, reduces neuroinflammation and brain injury after ischemia/reperfusion. The therapeutic potential of targeting TSPO requires further investigations in ischemic stroke

    A translocator protein 18 kDa agonist protects against cerebral ischemia/reperfusion injury

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    Background: Cerebral ischemia is a leading cause of death and disability with limited treatment options. Although inflammatory and immune responses participate in ischemic brain injury, the molecular regulators of neuroinflammation after ischemia remain to be defined. Translocator protein 18 kDa (TSPO) mainly localized to the mitochondrial outer membrane is predominantly expressed in glia within the central nervous system during inflammatory conditions. This study investigated the effect of a TSPO agonist, etifoxine, on neuroinflammation and brain injury after ischemia/reperfusion. Methods: We used a mouse model of middle cerebral artery occlusion (MCAO) to examine the therapeutic potential and mechanisms of neuroprotection by etifoxine. Results: TSPO was upregulated in Iba1(+) or CD11b(+) CD45(int) cells from mice subjected to MCAO and reperfusion. Etifoxine significantly attenuated neurodeficits and infarct volume after MCAO and reperfusion. The attenuation was pronounced in mice subjected to 30, 60, or 90 min MCAO. Etifoxine reduced production of pro-inflammatory factors in the ischemic brain. In addition, etifoxine treatment led to decreased expression of interleukin-1 beta, interleukin-6, tumor necrosis factor-alpha, and inducible nitric oxide synthase by microglia. Notably, the benefit of etifoxine against brain infarction was ablated in mice depleted of microglia using a colony-stimulating factor 1 receptor inhibitor. Conclusions: These findings indicate that the TSPO agonist, etifoxine, reduces neuroinflammation and brain injury after ischemia/reperfusion. The therapeutic potential of targeting TSPO requires further investigations in ischemic stroke.American Heart Association [16SDG27250236]; National Science Foundation of China [81471535]; Ministry of Human Resources and Social Security of China [2016]; Tianjin Education Commission Foundation [14JCYBJC42000]; Tianjin Medical University Graduate Student Innovation Foundation [YJSCX201718]This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

    Depletion Of Microglia Augments The Dopaminergic Neurotoxicity Of Mptp

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    The activation ofmicroglia and the various substances they produce have been linked to the pathologic development of Parkinson\u27s disease (PD), but the precise role ofmicroglia inPDremains tobe defined.The survival of microglia depends on colony-stimulating factor 1 receptor (CSF1R) signaling, and CSF1R inhibition results in rapid elimination of microglia in the central nervous system. Using a mouse PD model induced by 1-methyl-4- phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment, we showed that the depletion of microglia via the CSF1R inhibitor PLX3397 exacerbated the impairment of locomotor activities and the loss of dopaminergic neurons. Further, depletion of microglia augmented the production of inflammatorymediators and infiltration of leukocytes in the brain after MPTP exposure. Microglia depletion-induced aggravation of MPTP neurotoxicity was also seen in lymphocyte-deficientmice. In addition, the depletion ofmicroglia did not affect the production of brain-derived neurotrophic factor, but it dramatically augmented the production of inflammatory mediators by astrocytes after MPTP treatment. Our findings suggest microglia play a protective role against MPTP-induced neuroinflammation and dopaminergicneurotoxicity
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