Publications by authors named "Pei- Yu Shih"

Hematopoietic progenitor kinase 1 (HPK1) negatively affects T cell activation and proliferation and is a promising target for immunotherapy. Although HPK1 inhibitors have shown promising efficacy in preclinical models, none have been approved for clinical use. One significant challenge in developing an HPK1 inhibitor is the difficulty in designing a potent inhibitor with good kinase selectivity and pharmacokinetic properties.

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Article Synopsis
  • Neuroinflammation plays a significant role in Alzheimer's disease, with the NLRP3 inflammasome being crucial in this process by promoting the maturation of inflammatory cytokines like IL-1β and IL-18 and influencing tau phosphorylation.
  • This study utilized organotypic brain slice cultures and various mouse models to examine how tau seeds activate the NLRP3 inflammasome and how inhibiting NLRP3 might affect tau pathology.
  • Results indicated that NLRP3 activation is linked to increased tau pathology and neurodegeneration, showcasing its potential as a therapeutic target in Alzheimer's disease treatment.
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Although immune checkpoint inhibitors (ICIs) have been a revelation for treating several cancers, an unmet need remains to broaden ICI therapeutic scope and increase their response rates in clinical trials. Hematopoietic progenitor kinase 1 (HPK1) is a negative regulator of T cell activation and has previously been identified as a promising target for immunotherapy. Herein, we report the discovery of a series of HPK1 inhibitors with novel 1(2H)-phthalazinone and 1(2H)-isoquinolinone scaffolds.

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Over the last decade, there has been a growing interest in intrabodies and their therapeutic potential. Intrabodies are antibody fragments that are expressed inside a cell to target intracellular antigens. In the context of intracellular protein misfolding and aggregation, such as tau pathology in Alzheimer's disease, intrabodies have become an interesting approach as there is the possibility to target early stages of aggregation.

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Glutamatergic transmission prompts K efflux through postsynaptic NMDA receptors. The ensuing hotspot of extracellular K elevation depolarizes presynaptic terminal, boosting glutamate release, but whether this also affects glutamate uptake in local astroglia has remained an intriguing question. Here, we find that the pharmacological blockade, or conditional knockout, of postsynaptic NMDA receptors suppresses use-dependent increase in the amplitude and duration of the astrocytic glutamate transporter current (I ), whereas blocking astrocytic K channels prevents the duration increase only.

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Neurogenin 2 encodes a neural-specific transcription factor (NGN2) able to drive neuronal fate on somatic and stem cells. NGN2 is expressed in neural progenitors within the developing central and peripheral nervous systems. Overexpression of NGN2 in human induced pluripotent stem cells (hiPSCs) or human embryonic stem cells has been shown to efficiently trigger conversion to neurons.

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Astrocytes, the main supportive cell type of the brain, show functional impairments upon ageing and in a broad spectrum of neurological disorders. Limited access to human astroglia for pre-clinical studies has been a major bottleneck delaying our understanding of their role in brain health and disease. We demonstrate here that functionally mature human astrocytes can be generated by SOX9 overexpression for 6 days in pluripotent stem cell (PSC)-derived neural progenitor cells.

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Due to the high incidence of nosocomial infection, the first-line drugs for infection have been heavily used, and the emergence of drug-resistant strains has gradually increased. Thus, a new antifungal drug or therapeutic method is needed. Chitosan, a product of chitin deacetylation, is considered to be potentially therapeutic for fungal infections because of its excellent biocompatibility, biodegradability and low toxicity.

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Astrocytes express a complex repertoire of intracellular Ca transients (events) that represent a major form of signaling within individual cells and in astrocytic syncytium. These events have different spatiotemporal profiles, which are modulated by neuronal activity. Spontaneous Ca events appear more frequently in distal astrocytic processes and independently from each other.

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Objective: Due to the presence of neuropsychiatric behaviors and the decreased ability for activities of daily living (ADLs), family caregivers experience high burden levels in caring for people with dementia (PWD). This study sought to test the mediating role of caregiving hours in association with PWDs' ability for basic activities of daily living (BADL) function or neuropsychiatric behaviors and caregiver burden.

Methods: This study used two waves of survey data, collected between 2013 and 2016, from 186 PWD-caregiver dyads in a dementia clinic at a teaching hospital in southern Taiwan.

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Detecting membrane potentials is critical for understanding how neuronal networks process information. We report a vibrational spectroscopic signature of neuronal membrane potentials identified through hyperspectral stimulated Raman scattering (SRS) imaging of patched primary neurons. High-speed SRS imaging allowed direct visualization of puff-induced depolarization of multiple neurons in mouse brain slices, confirmed by simultaneous calcium imaging.

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Objective: Given the shortage of cost-of-illness studies in dementia outside of the Western population, the current study estimated the annual cost of dementia in Taiwan and assessed whether different categories of care costs vary by severity using multiple disease-severity measures.

Methods: This study included 231 dementia patient-caregiver dyads in a dementia clinic at a national university hospital in southern Taiwan. Three disease measures including cognitive, functional, and behavioral disturbances were obtained from patients based on medical history.

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Nicotinic acetylcholine receptors (nAChRs) are the molecular target of nicotine. nAChRs in the medial habenula (MHb) have recently been shown to play a role in nicotine dependence, but it is not clear which nAChR subtypes or MHb neuron types are most important. To identify MHb nAChRs and/or cell types that play a role in nicotine dependence, we studied these receptors and cells with brain slice electrophysiology using both acute and chronic nicotine application.

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Neuronal nAChRs in the medial habenula (MHb) to the interpeduncular nucleus (IPN) pathway are key mediators of nicotine's aversive properties. In this paper, we report new details regarding nAChR anatomical localization and function in MHb and IPN. A new group of knock-in mice were created that each expresses a single nAChR subunit fused to GFP, allowing high-resolution mapping.

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Two-photon florescence imaging is widely used to perform morphological analysis of subcellular structures such as neuronal dendrites and spines, astrocytic processes etc. This method is also indispensable for functional analysis of cellular activity such as Ca2+ dynamics. Although spatial resolution of laser scanning two-photon system is greater than that of confocal or wide field microscope, it is still diffraction limited.

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Astrocytes produce a complex repertoire of Ca2+ events that coordinate their major functions. The principle of Ca2+ events integration in astrocytes, however, is unknown. Here we analyze whole Ca2+ events, which were defined as spatiotemporally interconnected transient Ca2+ increases.

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Synaptic NMDA receptors (NMDARs) carry inward Ca(2+) current responsible for postsynaptic signaling and plasticity in dendritic spines. Whether the concurrent K(+) efflux through the same receptors into the synaptic cleft has a physiological role is not known. Here, we report that NMDAR-dependent K(+) efflux can provide a retrograde signal in the synapse.

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Glutamate uptake, mediated by electrogenic glutamate transporters largely localized in astrocytes, is responsible for the clearance of glutamate released during excitatory synaptic transmission. Glutamate uptake also determines the availability of glutamate for extrasynaptic glutamate receptors. The efficiency of glutamate uptake is commonly estimated from the amplitude of transporter current recorded in astrocytes.

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Tobacco addiction is a serious threat to public health in the United States and abroad, and development of new therapeutic approaches is a major priority. Nicotine activates and/or desensitizes nicotinic acetylcholine receptors (nAChRs) throughout the brain. nAChRs in ventral tegmental area (VTA) dopamine (DA) neurons are crucial for the rewarding and reinforcing properties of nicotine in rodents, suggesting that they may be key mediators of nicotine's action in humans.

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Article Synopsis
  • Neuronal activity affects calcium ion (Ca2+) levels in astrocytes, and researchers created a special mouse model to study the significance of these changes by using an "IP3 sponge" to reduce Ca2+ signaling in astrocytes.
  • The reduced Ca2+ signaling was linked to less coverage of synapses by astrocytes in the hippocampus, leading to increased glutamate “spillover” and enhanced receptor activity in nearby neurons.
  • Behavioral tests indicated that these changes negatively impacted the mice's memory, specifically their spatial reference memory and contextual fear responses.
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Noradrenergic (NAergic) A7 neurons are involved in modulating nociception by releasing noradrenaline in the dorsal spinal cord. Since NAergic A7 neurons receive dense Substance P (Sub-P) releasing terminals from ventromedial medulla, here we tested the effect of Sub-P on them. Bath application of Sub-P induced an inward current (I(Sub-P)) in NAergic neurons, which was significantly blocked by Neurokinin 1 (NK1) receptor antagonist.

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