Neurobiology of Disease最新文献

De novo variants in a subset of ionotropic glutamate receptor (iGluR) genes cause nonsyndromic neurodevelopmental disorders (NDDs). Two recurrent variants in the kainate receptor (KAR) gene GRIK2 result in the gain-of-function (GoF) substitutions p.Ala657Thr and p.Thr660Lys in a critical pore-forming domain of the GluK2 subunit. Disorders in individuals with these variants manifest as intellectual disability, developmental delay, motor impairments, and, in the case of p.Thr660Lys, epilepsy. To explore their pathogenicity and phenotypic consequences in vivo, we generated knock-in mouse models harboring orthologous Grik2 mutations. Behavioral analyses revealed a range of developmental, motor, cognitive, and naturalistic behavior impairments in both lines, with the mouse model of the variant of p.Thr660Lys, GluK2(T660K), exhibiting more severe phenotypes, consistent with clinical observations in humans. GluK2(T660K) mice also display interictal EEG abnormalities and handling-induced seizures. These models establish the first in vivo platforms for dissecting the underlying mechanisms of NDDs caused by a GoF mutation in the GluK2 KAR subunit and represent crucial tools for therapeutic development.

The neurovascular unit (NVU) is a highly integrated multicellular complex composed of neurons, astrocytes, microglia, brain microvascular endothelial cells (BMECs), pericytes, and the extracellular matrix (ECM). It forms the structural and functional basis of the blood-brain barrier (BBB) and is pivotal for maintaining the homeostasis of the brain. Traditional neuroprotective strategies targeting individual cell types have shown limited efficacy in central nervous system (CNS) diseases, mainly due to the neglect of intricate intercellular crosstalk within the NVU. In this review, we first systematically summarize the core mechanisms by which the NVU functional unit causes NVU dysfunction in representative acute CNS injuries (ischemic/hemorrhagic stroke, traumatic brain injury), neurodegenerative diseases (Alzheimer's disease, Parkinson's disease, multiple sclerosis), and systemic diseases (diabetic encephalopathy, depression). Based on this, we innovatively summarize and clarify six major cross-disease pathological mechanisms of NVU dysfunction, including intercellular communication disorders, abnormal epigenetic modifications, microbiome-NVU interaction dysregulation, metabolic reprogramming dysfunction, neuroimmune-vascular coupling imbalance, and mechanical microenvironment imbalance. Additionally, we integrate emerging NVU models (co-culture systems, organoids, microfluidic chips, 3D bioprinting) with multi-omics technologies to establish a cross-scale dynamic research paradigm, and propose multicomponent coordinated regulatory strategies for NVU-targeted therapies. This framework aims to expand the understanding of NVU-centered pathological processes across diverse CNS diseases and provides a novel theoretical basis for precise therapeutic interventions, thereby bridging the gap between basic research and clinical translation.

The phosphorylation of tau is a critical determinant of both its physiological function and the induction of pathological misfolding and aggregation. We have previously provided evidence that tau phosphorylation at Thr175 results in the exposure of the N-terminal phosphatase-activating domain (PAD) leading to the subsequent phosphorylation of Thr231, and formation of tau oligomers. A number of tauopathies, including chronic traumatic encephalopathy (CTE), amyotrophic lateral sclerosis with cognitive impairment (ALSci), and experimental traumatic brain injury (TBI) have been proposed to be associated with this cascade of events. However, the cellular mechanism by which Thr175 tau is phosphorylated remains unclear. In this study we identified ERK2, JNK1, and p38 as candidate kinases through molecular and histological analyses in a rodent model of TBI, where increased kinase activity and protein interaction were associated with pThr175 tau. We confirmed that both ERK2 and JNK1 are capable of phosphorylating Thr175 tau in vitro, but only ERK2-mediated phosphorylation of Thr175 tau induced the pathological cascade characterized by PAD exposure and the generation of oligomeric, truncated and neurofibrillary tau. Thr175 phosphorylation was also associated with an altered interaction between tau and the molecular chaperone protein DnaJC7, which regulates tau misfolding. Additionally, we observed that pThr175 and pThr231 tau were increased by oxidative stress, which was associated with the activation of the MAPK signaling pathways. These findings further clarify the mechanisms leading to Thr175 tau phosphorylation and its role in pathological tau formation by identifying ERK1 and JNK2 as important cellular mediators.

Patient induced pluripotent stem cell (iPSC)-based models represent a powerful human system to gain insights into the etiopathology of Parkinson's disease (PD). Here, we studied several iPSC-derived dopamine neuron (iPSC-DAN) lines, from individuals with idiopathic PD, which is the most common form of PD. Specifically, using iPSC-DAN differentiated for 50-55 days, we performed an in-depth analysis of different bioenergetic pathways and cellular quality control mechanisms in the cells. Our results showed wide ranging impairments in oxidative phosphorylation (OXPHOS), glycolysis and creatine kinase pathways in the PD dopamine (DA) neurons. Specifically, the PD neurons exhibited reduced oxygen consumption rates (OCR) at baseline and after challenges with mitochondrial inhibitors, as well as decreased glycolytic reserves measured via ECAR. This translated to lower OCR:ECAR ratios signifying more reliance on glycolysis vs OXPHOS in the PD cells. Moreover, a mislocalization of creatine kinase B to mitochondria was seen in the PD cells. These energetic changes occurred alongside the enhanced expression of mitochondrial fission proteins, disrupted mitophagy and oxidative stress. Additionally, the PD neurons contained more monomeric, phosphorylated, and aggregated forms of alpha synuclein and displayed reduced viability. Ultrastructural examination through immuno-electron microscopy showed more alpha synuclein gold particles directly associated with mitochondria and packed into autophagic vesicles. In essence, these data capture a web of key changes, associated with neuronal degeneration, in human iPSC-DAN from persons with idiopathic PD.