Biology subjects

Klinger, K.

Publications and source records attributed to Klinger, K..

5 recordsLinked to original sources

bioRxiv2026

Antibody treatment targeting nitrated alpha-synuclein counteracts protein spreading pathology

-Synuclein nitration is a prominent post-translational modification in Parkinsons disease, but whether nitrated -synuclein merely reflects oxidative stress or actively contributes to pathology remains unclear. Here, we generated and characterized 6G6, an antibody selective for Tyr39-nitrated -synuclein, and tested whether targeting this modified -synuclein species affected pathology in different mouse models of -synuclein aggregation and spread. In two models of -synuclein overexpression targeting medullary vagal neurons, oxidative stress was induced by either exposure to the herbicide paraquat or transgenic heterozygous expression of the Gba1-L444P mutation. Both conditions were characterized by robust -synuclein spreading that was markedly counteracted by 6G6 administration. A third model consisted of an injection of -synuclein fibrils into the striatum of -synuclein-overexpressing mice. In this model, treatment with 6G6 protected against fibril-induced aggregate pathology and ensuing degeneration of nigral dopaminergic neurons. In a pilot human study, CSF levels of Tyr39-nitrated -synuclein were measured and found increased in Parkinson patients as compared to controls. These findings identify Tyr39-nitrated -synuclein as a pathogenic, therapeutically targetable -synuclein species linking oxidative/nitrative stress to PD pathological processes.

neuroscience↗

bioRxiv2023

Increasing NPYergic transmission in the hippocampus rescues aging-related deficits of long-term potentiation in the mouse dentate gyrus

Loss of neuropeptide Y (NPY)-expressing interneurons in the hippocampus and decaying cholinergic neuromodulation are thought to contribute to impaired cognitive function during aging. However, the interaction of these two neuromodulatory systems in maintaining hippocampal synaptic plasticity during healthy aging has not been explored so far. Here we report profound sex differences in the Neuropeptide-Y (NPY) levels in the dorsal dentate gyrus (DG) with higher NPY concentrations in the male mice compared to their female counterparts and a reduction of NPY levels during aging specifically in males. This change in aged males is accompanied by a deficit in theta burst-induced long-term potentiation (LTP) in the medial perforant path-to-dorsal DG (MPP-DG) synapse, which can be rescued by enhancing cholinergic activation with the acetylcholine esterase blocker, physostigmine. Importantly, NPYergic transmission is required for this rescue of LTP. Moreover, exogenous NPY application alone is sufficient to recover LTP induction in aged male mice, even in the absence of the cholinergic stimulator. Together, our results suggest that in male mice NPYergic neurotransmission is a critical factor for maintaining dorsal DG LTP during aging.

neuroscience↗

bioRxiv2022

Neuroinflammation in neuronopathic Gaucher disease: Role of microglia and NK cells

BackgroundNeuronopathic Gaucher Disease (nGD) is a rare neurodegenerative disorder caused by biallelic mutations in Gba, and buildup of glycosphingolipids in lysosomes. Neuronal injury and cell death are prominent pathological features, however the role of Gba in individual cell types and involvement of microglia, blood derived macrophages and immune infiltrates in nGD pathology remains enigmatic. MethodsHere, using single cell resolution of mouse nGD brains, we found induction of neuroinflammation pathways involving microglia, NK cells, astrocytes, and neurons. ResultsTargeted rescue of Gba in microglia and in neurons, respectively in Gba deficient, nGD mice reversed the buildup of glucosylceramide (GlcCer) and glucosylsphingosine (GlcSph), concomitant with amelioration of neuroinflammation, reduced level of serum neurofilament light chain (Nf-L) and improved survival. The levels of bioactive lipid, GlcSph was strongly correlated with serum Nf-L and ApoE in nGD mouse models as well as GD patients. Gba rescue in microglia/macrophage compartment prolonged survival, that was further enhanced upon treatment with brain permeant inhibitor of glucosylceramide synthase, effects mediated via improved glycosphingolipid homeostasis and reversal of neuroinflammation involving activation of microglia, brain macrophages and NK cells. ConclusionsTogether, our study delineates individual cellular effects of Gba deficiency in nGD brains, highlighting the central role of neuroinflammation driven by microglia activation and the role of brain permeant small molecule glucosylceramide inhibitor in reversing complex multidimensional pathophysiology of nGD. Our findings advance disease biology whilst identifying compelling biomarkers of nGD to improve patient management, enrich clinical trials and illuminate therapeutic targets. FundingResearch grant from Sanofi Genzyme; other support includes R01NS110354.Yale Liver Center P30DK034989, pilot project grant.

immunology↗

bioRxiv2022

Fear engrams and NPYergic circuit in the dorsal dentate gyrus determine remote fear memory generalization.

Generalization is a critical feature of aversive memories and significantly contributes to post-traumatic stress disorder (PTSD) pathogenesis. While fear memories over time tend to generalize across differences in the contextual background and even to novel contextual settings, this effect can be counteracted by exposure to controlled reminder sessions even at remote time points. Using Pavlovian fear conditioning in mice, we show that generalization to a novel context of remote memory is associated with a loss of cellular engram activation in the dorsal dentate gyrus (dDG) and can be effectively counteracted by a preceding contextual reminder session. In addition to engram cells activation in response to a novel context, the reminder session also leads to a recovery of neuropeptide Y (NPY) function in the dDG and dDG-CA3 neurotransmission. In line with a proposed role of NPY as a resilience factor, we found that chronic viral knockdown of NPY in the dDG and blockage of its activity-dependent expression in NPYergic dDG interneurons with dominant-negative CREBS133A both increase remote memory generalization. With chemogenetic silencing of these interneurons, we could localize their critical involvement to a time window during and immediately following the fear memory acquisition. Together, these findings suggest that NPYergic interneurons of the dDG, shaping the memory engram during fear learning and early consolidation, determine fear generalization.

neuroscience↗

bioRxiv2020

Network Analysis and Human Single Cell Brain Transcriptomics Reveal Novel Aspects of Alpha-Synuclein (SNCA) Biology

Alpha-synuclein (SNCA) aggregates are pathological hallmarks of synucleinopathies, neurodegenerative disorders including Parkinsons Disease (PD) and Lewy Body Dementia (LBD). Functional networks are not yet well-characterized for SNCA by CNS cell type. We investigated cell-specific differences in SNCA expression using Allen Brain Database single-nucleus RNA-seq data from human Middle Temporal Gyrus (MTG, 15,928 nuclei) and Anterior Cingulate Cortex (ACC, 7,258 nuclei). Weighted gene co-expression analysis (WGCNA) and hierarchical clustering identified a conserved SNCA co-expression module. Module genes were highly conserved (p < 10-10) and most highly expressed in excitatory neurons versus inhibitory neurons and other glial cells. SNCA co-expression module genes from ACC and MTG regions were then used to construct a protein-protein interaction (PPI) network, with SNCA empirically top hub. Genes in the SNCA PPI network were compared with genes nearest single nucleotide polymorphisms linked with PD risk in genome-wide association studies. 16 genes in our PPI network are nearest genes to PD risk loci (p < 0.0006) and 55 genes map within 100kb. Selected SNCA PPI network genes nearest PD risk loci were disrupted by CRISPR knock out gene editing for validation of network functional significance; disruption of STK39, GBA, and MBNL2 resulted in significantly elevated intracellular SNCA expression.

neuroscience↗