Aceruloplasminemia is an autosomal recessive disorder caused by mutations in the ceruloplasmin (CP) gene. It is characterized by iron accumulation in the brain and in visceral organs. However, little is known about the mechanism of iron transport in these regions. Adult CP null (CP(-/-)) mice show increased iron deposition in several regions of brain, such as the cerebellum and brainstem. In this study, we investigated the expression of the ceruloplasmin homolog hephaestin (Heph) in the brain of CP(-/-) mice as a function of age. In the cerebral cortex and caudate putamen of 80-week-old CP(-/-) mice, the expression of Heph increased significantly whilst iron levels remain normal [Patel BN, Dunn RJ, Jeong SY, Zhu Q, Julien JP, David S. Ceruloplasmin regulates iron levels in the CNS and prevents free radical injury. J Neurosci 2002;22(15):6578-6], indicating that Heph might compensate for the loss of CP. In contrast, the substantia nigra and cerebellum of 80-week-old CP(-/-) mice accumulate iron but do not express high levels or significant decrease of Heph, suggesting that Heph does not replace CP in these regions. These data suggest that Heph may compensate for the loss of CP in a region-specific manner.
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http://dx.doi.org/10.1016/j.jtemb.2009.05.004 | DOI Listing |
Cell Rep
January 2025
Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address:
Tumor-draining lymph node dendritic cells (DCs) are poor stimulators of tumor antigen-specific CD4 T cells; however, the mechanism behind this defect is unclear. We now show that, in tumor-draining lymph node DCs, a large proportion of major histocompatibility complex class II (MHC-II) molecules retains the class II-associated invariant chain peptide (CLIP) fragment of the invariant chain bound to the MHC-II peptide binding groove due to reduced expression of the peptide editor H2-M and enhanced activity of the CLIP-generating proteinase cathepsin S. The net effect of this is that MHC-II molecules are unable to efficiently bind antigenic peptides.
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December 2024
Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Background: Clinicopathological studies of Alzheimer's disease (AD) have demonstrated that synaptic or neuronal loss and clinical cognitive decline do not reliably correlate with fibrillar amyloid burden. We created a transgenic mouse model overexpressing Dutch (E693Q) mutant human amyloid precursor protein (APP) driven by the pan-neuronal Thy1 promoter. Accumulation of APP carboxyl-terminal fragments was observed in the brains of these mice, which develop an impaired learning phenotype directly proportional to brain oAβ levels.
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December 2024
University of Georgia, Athens, GA, USA.
Background: Inflammatory cells play a key role in the pathophysiology of AD and other neurodegenerative disorders. Glycans are known to mediate inflammatory cell activation and migration yet very little is understood about the expression of glycans, glycoproteins, and other glycoconjugates at the CP which serves as a gateway for peripheral immune cells into the brain. In a familial AD mouse model, we observed increased expression of Siglec-F-recognized glycans on CP epithelial cells.
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December 2024
Department of Pediatrics, Division of Infectious Diseases and Immunology, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
Background: Alzheimer's disease (AD) is a progressive irreversible dementia characterized by beta-amyloid protein plaque deposition and hyperphosphorylation of tau forming neurofibrillary tangles, and neurodegeneration. An emerging theory posits that infections could be one of the triggering factors in AD development and progression. Multiple lines of evidence have linked Chlamydia pneumoniae (Cp), a gram-negative obligate intracellular bacterium with AD.
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December 2024
Westlake Genetech, Ltd., No. 1 Yunmeng Road, Cloud Town, Hangzhou 310024, China; School of Life Sciences, Westlake University, 600 Dunyu Road, Hangzhou 310030, China. Electronic address:
Efficient prime editor (PE) delivery in vivo is critical for realizing its full potential in disease modeling and therapeutic correction. Although PE has been divided into two halves and delivered using dual adeno-associated viruses (AAVs), the editing efficiency at different gene loci varies among split sites. Furthermore, efficient split sites within Cas9 nickase (Cas9n) are limited.
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