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Biology subjects

Lee, H. E.

Publications and source records attributed to Lee, H. E..

4 recordsLinked to original sources

NADPH oxidase inhibitor enhances brain resilience in Alzheimer's disease by reducing tauopathy and neuroinflammation

Alzheimers disease associates closely with activation of NADPH oxidase (Nox) isozymes. We identified that CRB-2131, a novel oxadiazole derivative, potently suppresses Nox isozymes. It inhibits reactive oxygen species production (ROS) by hippocampal neuronal and microglial cells and reduces microglial activation. Prophylactic (starting at 3.5 months of age) and therapeutic (starting at 6 months of age) oral administration with CRB-2131 for 10 weeks in 5XFAD mice reduced hippocampal superoxide levels, lipid peroxidation, Tau phosphorylation, and neuroinflammation. Prophylactic and therapeutic CRB-2131 treatment of 5XFAD mice restored their impaired cognition as shown by the novel-object recognition, Y-maze, and Morris water-maze tests. CRB-2131 treatment increased mature neurons, reduced apoptotic mature neurons, and elevated immature neurons in the hippocampus. Positron-emission tomography/computed-tomography imaging confirmed that CRB-2131 stimulated neuronal regeneration. CRB-2131 suppresses brain oxidation, tauopathy, and neuroinflammation, thereby preventing mature neuron death and promoting neuron regeneration. Ultimately, this fosters a resilient brain and protects cognition.

neuroscience↗

Retention of ES cell-derived 129S genome drives NLRP1 hypersensitivity and transcriptional deregulation in Nlrp3-/- mice

Immune response genes are highly polymorphic in humans and mice, with heterogeneity amongst loci driving strain-specific host defense responses. The inadvertent retention of polymorphic loci can introduce confounding phenotypes, leading to erroneous conclusions, and impeding scientific advancement. In this study, we employ a combination of RNAseq and variant calling analyses and identify a substantial region of 129S genome, including the highly polymorphic Nlrp1 locus proximal to Nlrp3, in one of the most commonly used mouse models of NLRP3 deficiency. We show that increased expression of 129S NLRP1b sensitizes Nlrp3-/- macrophages to NLRP1 inflammasome activation. Furthermore, the presence of 129S genome leads to altered gene and protein regulation across multiple cell-types, including of the key tissue-resident macrophage marker, TIM4. To address the challenge of resolving NLRP3-dependent phenotypes, we introduce and validate a conditional Nlrp3 allele, enabling precise temporal and cell-type-specific control over Nlrp3 deletion. Our study establishes a generic framework to identify functionally relevant SNPs and assess genomic contamination in transgenic mice. This allows for unambiguous attribution of phenotypes to the target gene and advances the precision and reliability of research in the field of host defense responses.

immunology↗

Vutiglabridin Alleviates Cellular Senescence Process of Dysfunctional Replication, Metabolic Regulation, and Circadian Clock in Primary Human Dermal Fibroblasts

The process of cellular senescence, which is characterized by stable cell cycle arrest, is strongly associated with dysfunctional cellular metabolism and circadian rhythmicity, both of which are reported to result from and also be causal to cellular senescence. As a result, modifying any of them - senescence, metabolism, or the circadian clock - may affect all three simultaneously. Obesity accelerates aging by disrupting the homeostasis of reactive oxygen species (ROS) via an increased mitochondrial burden of fatty acid oxidation. As a result, if senescence, metabolism, and circadian rhythm are all linked, anti-obesity treatments may improve metabolic regulation while also alleviating senescence and circadian rhythm. Vutiglabridin is a small molecule in clinical trials that improves obesity by enhancing mitochondrial function. We found that chronic treatment of senescent primary human dermal fibroblasts (HDFs) with vutiglabridin alleviates all investigated markers of cellular senescence (SA-{beta}-gal, CDKN1A, CDKN2A) and dysfunctional cellular circadian rhythm (BMAL1), while remarkably preventing the alterations of mitochondrial function and structure that occur during the process of cellular senescence. Our results demonstrate the significant senescence-alleviating effects of vutiglabridin, specifically with the restoration of cellular circadian rhythmicity and metabolic regulation. These data support the potential development of vutiglabridin against aging-associated diseases and corroborate the intricate link between cellular senescence, metabolism, and the circadian clock.

physiology↗

Exploring the association of collaterals and vessel density using optical coherence tomography angiography in retinal vein occlusions

PurposeUsing optical coherence tomography angiography (OCTA) to characterize the types of collaterals in eyes with retinal vein occlusion (RVO) and further investigate their correlations with vessel densities of the superficial (SCP) and the deep capillary plexus (DCP).\n\nMethodsThis cross-sectional study included 25 eyes of 23 patients with RVO. 3 x 3 mm2 OCTA macular scans were used to quantify the parafoveal vessel density (VD) of the SCP and DCP, and to classify the collaterals into one of four types (true superficial, true deep, superficial diving, and foveal collateral). Poisson regression model was used to identify significant associations between parafoveal VD and collaterals. We further compared parafoveal VD between subgroups classified by the presence of specific collateral types based on the results of a clustering algorithm.\n\nResults16 of 25 eyes (64%) developed collaterals. Of the 43 collateral vessels analyzed, 12/19 (63%) true superficial collaterals developed in eyes with central RVO, while all 10 superficial diving collaterals (100%) developed in eyes with branch RVO. Located exclusively in the SCP, true superficial collaterals were all arteriovenous (A-V), while diving collaterals were all veno-venular (V-V). We found a significant negative correlation between SCP VD and the total number of collaterals (R2 = 0.648, P < 0.001) for the entire study cohort. Furthermore, BRVO eyes that developed superficial diving collaterals and CRVO eyes that developed true superficial collaterals demonstrated statistically significant decrease in SCP VD (P-value = 0.014) and DCP VD (P-value = 0.030), respectively, as compared to their counterparts.\n\nConclusionOur data shows that decreased capillary perfusion in RVO is associated with the development of collaterals, while the RVO type largely dictates the type of collateral that ultimately develops.

physiology↗