Increasing evidence links dysregulation of NR2B-containing
N
-methyl-
d
-aspartate receptor remodelling and trafficking to Alzheimer’s disease (AD). This theme offers the possibility that the GRIN2B ...gene, encoding this selective NR2B subunit, represents a potential molecular modulating factor for this disease. Based on this hypothesis, we carried out a mutation scanning of exons and flanking regions of GRIN2B in a well-characterized cohort of AD patients, recruited from Southern Italy. A “de novo” p.K1293R mutation, affecting a highly conserved residue of the protein in the C-terminal domain, was observed for the first time in a woman with familial AD, as the only genetic alteration of relevance. Moreover, an association study between the other detected sequence variants and AD was performed. In particular, the study was focused on five identified single nucleotide polymorphisms: rs7301328, rs1805482, rs3026160, rs1806191 and rs1806201, highlighting a significant contribution from the GRIN2B rs1806201 T allele towards disease susceptibility adjusted odds ratio (OR) = 1.92, 95% confidence interval (CI) 1.40–2.63,
p
< 0.001, after correction for sex, age, and APOE ε4 genotype. This was confirmed by haplotype analysis that identified a specific haplotype, carrying the rs1806201 T allele (CCCTC), over-represented in patients versus controls (adjusted OR = 6.03;
p
< 0.0001). Although the pathogenic role of the GRIN2B-K1293R mutation in AD is not clear, our data advocate that genetic variability in the GRIN2B gene, involved in synaptic functioning, might provide valuable insights into disease pathogenesis, continuing to attract significant attention in biomedical research on its genetic and functional role.
The frequent development of drug resistance to targeted therapies in cancer patients has stimulated interest in strategies counteracting resistance. Combining immunotherapies with targeted therapies ...is one such strategy. In this context, we asked whether human NK cells can target melanoma cells that have acquired resistance to selective inhibitors targeting activating mutants of the B‐Raf kinase (BRAF inhibitors, BRAFi). We generated drug‐resistant cell variants in vitro from human BRAF‐mutant melanoma cell lines MEL‐HO, COLO‐38, SK‐MEL‐37, 1520 and from primary melanoma cells freshly isolated from two patients. All drug‐resistant cell variants remained susceptible to lysis by IL‐2‐activated NK cells; and two BRAFi‐resistant lines (BRAFi‐R) became significantly more susceptible to NK‐cell lysis than their parental lines. This was associated with significant HLA class I antigen downregulation and PD‐L1 upregulation on the drug‐resistant lines. Although blocking HLA class I enhanced the extent of lysis of both BRAFi‐R and parental cells to NK‐cell‐mediated lysis, antibody‐mediated inhibition of PD1–PD‐L1 interactions had no detectable effect. HLA class I antigen expression on BRAFi‐R melanoma variants thus appears to play a major role in their susceptibility to NK‐cell cytotoxicity. These findings suggest that NK‐cell‐based immunotherapy may be a viable approach to treat melanoma patients with acquired resistance to BRAF inhibitors.
The redox state of the cell is involved in the regulation of many physiological functions as well as in the pathogenesis of several diseases, and is strictly dependent on the amount of iron in its ...catalytically active state. Alterations of iron homeostasis determine increased steady-state concentrations of Reactive Oxygen Species (ROS) that cause lipid peroxidation, DNA damage and altered protein folding. Ferritin keeps the intracellular iron in a non-toxic and readily available form and consequently plays a central role in iron and redox homeostasis. The protein is composed by 24 subunits of the H- and L-type, coded by two different genes, with structural and functional differences. The aim of this study was to shed light on the role of the single H ferritin subunit (FHC) in keeping the native correct protein three-dimensional structure. To this, we performed Raman spectroscopy on protein extracts from K562 cells subjected to FHC silencing. The results show a significant increase in the percentage of disordered structures content at a level comparable to that induced by H2O2 treatment in control cells. ROS inhibitor and iron chelator were able to revert protein misfolding. This integrated approach, involving Raman spectroscopy and targeted-gene silencing, indicates that an imbalance of the heavy-to-light chain ratio in the ferritin composition is able to induce severe but still reversible modifications in protein folding and uncovers new potential pathogenetic mechanisms associated to intracellular iron perturbation.
•Raman analysis has been used to study protein conformation in FHC-silenced cells.•In K562 cells FHC silencing induces via ROS formation a severe protein misfolding.•The observed protein misfolding is a reversible phenomenon.•This integrated approach allows the study of specific biochemical pathways.
A 35-year-old young man displayed Leber’s optic neuropathy (LHON) due to T14484C and multiple sclerosis (MS) phenotype that was dominated by symptoms and signs of spinal cord impairment. Magnetic ...resonance imaging (MRI) revealed demyelinating lesions extending from D6 to D11 in the spinal cord with gadolinium enhancement, while only three linear demyelinating lesions were seen on brain MRI. In the literature, a major involvement of the spinal cord was already reported in three of four male patients with the 14484 LHON mutation who developed MS, but the reasons of this peculiar association remain unknown, and further research in this area is needed.
Abstract γ-Secretase proteins complex cleaves the amyloid precursor protein (APP) to generate amyloid-β (Aβ) peptides. Considerable evidence suggests that alterations in genes encoding these proteins ...exert their influence on the pathogenesis of familial Alzheimer's disease (FAD). Presenilin enhancer-2 gene ( PEN-2 ) is a necessary component of the γ-Secretase complex. Recently, it has been shown that PEN-2 mutations could be involved in Alzheimer's disease (AD). We performed a mutational screening of all PEN-2 coding and promoter regions in a FAD cohort derived from Southern Italy. Four hundred and fifty-two subjects (FAD: 97; Controls: 355) were recruited for this study. We identified for the first time in a key region necessary for the promoter activity a novel 3 bp deletion in a subject with early-FAD. Our genetic data demonstrate that the mutant allele may influence the transcriptional activity of the PEN-2 gene. Although the effective role of the PEN-2 promoter deletion in AD is not entirely clear, these findings might lead to more studies on its functional and genetic role.
I super(3)-Secretase proteins complex cleaves the amyloid precursor protein (APP) to generate amyloid-I super(2) (AI super(2)) peptides. Considerable evidence suggests that alterations in genes ...encoding these proteins exert their influence on the pathogenesis of familial Alzheimer's disease (FAD). Presenilin enhancer-2 gene (PEN-2) is a necessary component of the I super(3)-Secretase complex. Recently, it has been shown that PEN-2 mutations could be involved in Alzheimer's disease (AD). We performed a mutational screening of all PEN-2 coding and promoter regions in a FAD cohort derived from Southern Italy. Four hundred and fifty-two subjects (FAD: 97; Controls: 355) were recruited for this study. We identified for the first time in a key region necessary for the promoter activity a novel 3 bp deletion in a subject with early-FAD. Our genetic data demonstrate that the mutant allele may influence the transcriptional activity of the PEN-2 gene. Although the effective role of the PEN-2 promoter deletion in AD is not entirely clear, these findings might lead to more studies on its functional and genetic role.
Intrahepatic cholangiocarcinoma (ICC) is a rare, heterogeneous, highly lethal tumor of the biliary tract. Due to the lack of effective treatments, an early identification of ICC is essential to ...achieve the best outcome in terms of therapy and prognosis aiming for a curative intent. ICC may arise on a normal liver or with an underlying liver disease, making the diagnosis more difficult and complex. Contrast-enhancement ultrasound (CEUS) is an accurate procedure able to detect ICC-specific contrast vascular pattern, and thus facilitating the correlation between radiological and histopathological findings with high specificity and sensitivity. CEUS has been shown to have a high diagnostic potential in the diagnosis of ICC thanks to the possibility of studying in real time the intralesional microcirculation and evaluating the precocity of the enhancement of the lesion during the arterial phase. All these features allow to differentiate the ICC from hepatocarcinoma (HCC) with high sensitivity and specificity. Furthermore, CEUS is a rapid, non-invasive, non-nephrotoxic or non-allergenic tool. The only limitations CEUS may have are related to the disease site and patient characteristics (obesity) and compliance, including the operator’s experience. A clinical evaluation of the patient, together with tumor markers and biochemical tests assessment, to differentiate ICC from HCC are highly suggested.
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