Chronic intestinal inflammation significantly contributes to the development of colorectal cancer and remains a pertinent clinical challenge, necessitating novel therapeutic approaches. Indole-based microbial metabolite mimics Felix Kopp Kortagere 6 (FKK6), which is a ligand and agonist of the pregnane X receptor (PXR), was recently demonstrated to have PXR-dependent anti-inflammatory and protective effects in a mouse model of dextran sodium sulfate (DSS)-induced acute colitis. Here, we examined the therapeutic potential of FKK6 in a mouse model (C57BL/6 FVB humanized PXR mice) of colitis-associated colon cancer (CAC) induced by azoxymethane and DSS. FKK6 (2 mg/kg) displayed substantial antitumor activity, as revealed by reduced size and number of colon tumors, improved colon histopathology, and decreased expression of tumor markers (c-MYC, β-catenin, Ki-67, and cyclin D) in the colon. In addition, we carried out a chronic toxicity (30 days) assessment of FKK6 (1 mg/kg and 2 mg/kg) in C57BL/6 mice. Histological examination of tissues, biochemical blood analyses, and immunohistochemical staining for Ki-67 and γ-H2AX showed no difference between FKK6-treated and control mice. Comparative metabolomic analyses in mice exposed for 5 days to DSS and administered with FKK6 (0.4 mg/kg) revealed no significant effects on several classes of metabolites in the mouse fecal metabolome. Ames and micronucleus tests showed no genotoxic and mutagenic potential of FKK6 in vitro. In conclusion, anticancer effects of FKK6 in azoxymethane/DSS-induced CAC, together with FKK6 safety data from in vitro tests and in vivo chronic toxicity study, and comparative metabolomic study, are supportive of the potential therapeutic use of FKK6 in the treatment of CAC. SIGNIFICANCE STATEMENT: Microbial metabolite mimicry proposes that chemical mimics of microbial metabolites that serve to protect hosts against aberrant inflammation in the gut could serve as a new paradigm for the development of drugs targeting inflammatory bowel disease if, like the parent metabolite, is devoid of toxicity but more potent against the microbial metabolite receptor. We identified a chemical mimic of Felix Kopp Kortagere 6, and we propose that Felix Kopp Kortagere 6 is devoid of toxicity yet significantly reduces tumor formation in an azoxymethane-dextran sodium sulfate model of murine colitis-induced colon cancer.
- MeSH
- Azoxymethane toxicity MeSH
- Chronic Disease MeSH
- Indoles pharmacology therapeutic use MeSH
- Colitis drug therapy chemically induced metabolism pathology MeSH
- Colorectal Neoplasms * drug therapy metabolism pathology MeSH
- Disease Models, Animal * MeSH
- Molecular Mimicry MeSH
- Mice, Inbred C57BL * MeSH
- Mice MeSH
- Colitis-Associated Neoplasms pathology drug therapy metabolism MeSH
- Dextran Sulfate toxicity MeSH
- Inflammation drug therapy metabolism MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Alexander disease (AxD) is a rare and severe neurodegenerative disorder caused by mutations in glial fibrillary acidic protein (GFAP). While the exact disease mechanism remains unknown, previous studies suggest that mutant GFAP influences many cellular processes, including cytoskeleton stability, mechanosensing, metabolism, and proteasome function. While most studies have primarily focused on GFAP-expressing astrocytes, GFAP is also expressed by radial glia and neural progenitor cells, prompting questions about the impact of GFAP mutations on central nervous system (CNS) development. In this study, we observed impaired differentiation of astrocytes and neurons in co-cultures of astrocytes and neurons, as well as in neural organoids, both generated from AxD patient-derived induced pluripotent stem (iPS) cells with a GFAPR239C mutation. Leveraging single-cell RNA sequencing (scRNA-seq), we identified distinct cell populations and transcriptomic differences between the mutant GFAP cultures and a corrected isogenic control. These findings were supported by results obtained with immunocytochemistry and proteomics. In co-cultures, the GFAPR239C mutation resulted in an increased abundance of immature cells, while in unguided neural organoids and cortical organoids, we observed altered lineage commitment and reduced abundance of astrocytes. Gene expression analysis revealed increased stress susceptibility, cytoskeletal abnormalities, and altered extracellular matrix and cell-cell communication patterns in the AxD cultures, which also exhibited higher cell death after stress. Overall, our results point to altered cell differentiation in AxD patient-derived iPS-cell models, opening new avenues for AxD research.
- MeSH
- Alexander Disease * genetics pathology metabolism MeSH
- Astrocytes * metabolism pathology MeSH
- Cell Differentiation * physiology MeSH
- Glial Fibrillary Acidic Protein * metabolism genetics MeSH
- Induced Pluripotent Stem Cells * metabolism MeSH
- Coculture Techniques MeSH
- Cells, Cultured MeSH
- Humans MeSH
- Mutation MeSH
- Neural Stem Cells metabolism MeSH
- Neurons metabolism pathology MeSH
- Organoids metabolism pathology MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
BACKGROUND: Neurovascular conflict between the oculomotor nerve and a posterior circulation cerebral artery is a relatively frequent radiologic finding; however, it manifests minimally clinically (by slower photoreaction on the ipsilateral side). Sustained paresis of the oculomotor nerve that arose directly due to neurovascular conflict between the superior cerebral artery (SCA) and the oculomotor nerve, and resolved after microvascular decompression, is extremely rare and has not yet been published. METHODS: A 34-year-old female patient presented with an advancing ptosis and downward gaze on one side. Differential diagnostics ruled out all other causes of the oculomotor paresis. Magnetic resonance imaging showed significant compression of the oculomotor nerve by an aberrant SCA on the ipsilateral side. Neurovascular decompression performed microsurgically resulted in near complete resolution of the symptoms. RESULTS: This case report aims to present a case of a rare clinical condition caused by a generally common anatomical variation. This variation proved to be the only cause of the patient's symptoms, which resolved after microsurgical restoration of the neuroanatomy. CONCLUSIONS: Oculomotor nerve paresis caused directly by neurovascular conflict is an extremely rare diagnosis. Microvascular decompression should be considered in these cases, if other causes have been excluded.
- MeSH
- Adult MeSH
- Humans MeSH
- Magnetic Resonance Imaging MeSH
- Microvascular Decompression Surgery methods MeSH
- Cerebellum * blood supply MeSH
- Oculomotor Nerve Diseases * etiology surgery MeSH
- Oculomotor Nerve * surgery MeSH
- Paresis * etiology surgery MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Case Reports MeSH
In advanced prostate cancer (PC), in particular after acquisition of resistance to androgen receptor (AR) signaling inhibitors (ARSI), upregulation of AR splice variants compromises endocrine therapy efficiency. Androgen receptor splice variant-7 (ARV7) is clinically the most relevant and has a distinct 3' untranslated region (3'UTR) compared to the AR full-length variant, suggesting a unique post-transcriptional regulation. Here, we set out to evaluate the applicability of the ARV7 3'UTR as a therapy target. A common single nucleotide polymorphism, rs5918762, was found to affect the splicing rate and thus the expression of ARV7 in cellular models and patient specimens. Serine/arginine-rich splicing factor 9 (SRSF9) was found to bind to and increase the inclusion of the cryptic exon 3 of ARV7 during the splicing process in the alternative C allele of rs5918762. The dual specificity protein kinase CLK2 interferes with the activity of SRSF9 by regulating its expression. Inhibition of the Cdc2-like kinase (CLK) family by the small molecules cirtuvivint or lorecivivint results in the decreased expression of ARV7. Both inhibitors show potent anti-proliferative effects in enzalutamide-treated or -naive PC models. Thus, targeting aberrant alternative splicing at the 3'UTR of ARV7 by disturbing the CLK2/SRSF9 axis might be a valuable therapeutic approach in late stage, ARSI-resistant PC.
- MeSH
- 3' Untranslated Regions genetics MeSH
- Alternative Splicing genetics drug effects MeSH
- Receptors, Androgen * metabolism genetics MeSH
- Polymorphism, Single Nucleotide genetics MeSH
- Humans MeSH
- Cell Line, Tumor MeSH
- Prostatic Neoplasms * genetics metabolism pathology drug therapy MeSH
- Protein Isoforms genetics metabolism MeSH
- Protein Serine-Threonine Kinases genetics metabolism antagonists & inhibitors MeSH
- Gene Expression Regulation, Neoplastic * drug effects MeSH
- Serine-Arginine Splicing Factors * metabolism genetics MeSH
- RNA Splicing genetics MeSH
- Protein-Tyrosine Kinases * genetics metabolism MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Publication type
- Journal Article MeSH
Although chronic inflammation is implicated in the pathogenesis of diffuse large B-cell lymphoma (DLBCL), the mechanisms responsible are unknown. We demonstrate that the overexpression of the collagen receptor, DDR1, correlates with reduced expression of spindle checkpoint genes, with three transcriptional signatures of aneuploidy and with a higher frequency of copy number alterations, pointing to a potential role for DDR1 in the acquisition of aneuploidy in DLBCL. In support of this, we found that collagen treatment of primary germinal centre B cells transduced with DDR1, not only partially recapitulated the aberrant transcriptional programme of DLBCL but also downregulated the expression of CENPE, a mitotic spindle that has a crucial role in preventing chromosome mis-segregation. CENPE expression was also downregulated following DDR1 activation in two B-cell lymphoma lines and was lost in most DDR1-expressing primary tumours. Crucially, the inhibition of CENPE and the overexpression of a constitutively activated DDR1 were able to induce aneuploidy in vitro. Our findings identify a novel mechanistic link between DDR1 signalling and chromosome instability in B cells and provide novel insights into factors driving aneuploidy in DLBCL.
- MeSH
- Aneuploidy * MeSH
- B-Lymphocytes metabolism MeSH
- Chromosomal Instability * genetics MeSH
- Lymphoma, Large B-Cell, Diffuse * genetics pathology metabolism MeSH
- Collagen pharmacology MeSH
- Humans MeSH
- Cell Line, Tumor MeSH
- Discoidin Domain Receptor 1 * genetics metabolism MeSH
- Gene Expression Regulation, Neoplastic MeSH
- Signal Transduction MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
3-methylglutaconic aciduria (3-MGCA) is a biochemical finding in a diverse group of inherited metabolic disorders. Conditions manifesting 3-MGCA are classified into two major categories, primary and secondary. Primary 3-MGCAs involve two inherited enzymatic deficiencies affecting leucine catabolism, whereas secondary 3-MGCAs comprise a larger heterogeneous group of conditions that have in common compromised mitochondrial energy metabolism. Here, we report 3-MGCA in two siblings presenting with sensorineural hearing loss and neurological abnormalities associated with a novel, homozygous missense variant (c.1999C>G, p.Leu667Val) in the YME1L1 gene which encodes a mitochondrial ATP-dependent metalloprotease. We show that the identified variant results in compromised YME1L1 function, as evidenced by abnormal proteolytic processing of substrate proteins, such as OPA1 and PRELID1. Consistent with the aberrant processing of the mitochondrial fusion protein OPA1, we demonstrate enhanced mitochondrial fission and fragmentation of the mitochondrial network in patient-derived fibroblasts. Furthermore, our results indicate that YME1L1L667V is associated with attenuated activity of rate-limiting Krebs cycle enzymes and reduced mitochondrial respiration, which may explain the build-up of 3-methylglutaconic and 3-methylglutaric acid due to the diversion of acetyl-CoA, not efficiently processed in the Krebs cycle, towards the formation of 3-methylglutaconyl-CoA, the precursor of these metabolites. In summary, our findings classify YME1L1 deficiency as a new type of secondary 3-MGCA, thus expanding the genetic landscape and facilitating the diagnosis of inherited metabolic disorders featuring this biochemical phenotype.
- MeSH
- Child MeSH
- Fibroblasts metabolism MeSH
- Glutarates MeSH
- Humans MeSH
- Metalloendopeptidases * genetics metabolism MeSH
- Mutation, Missense MeSH
- Mitochondrial Dynamics MeSH
- Mitochondrial Proteins * genetics MeSH
- Mitochondria metabolism MeSH
- Hearing Loss, Sensorineural genetics MeSH
- Siblings MeSH
- Metabolism, Inborn Errors * genetics MeSH
- Check Tag
- Child MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Case Reports MeSH
The purpose of this study is to elucidate the genetic causes and phenotypic presentation of nonfamilial tall stature (nFTS) and to compare these findings with those of familial tall stature (FTS) from the same population that was previously studied. Children with nFTS (defined as a height > + 2 SDs with both parents' heights < + 2 SDs) underwent endocrine and anthropometric examinations and genetic testing (karyotyping, SHOX gene dosage analysis and next-generation sequencing of 786 growth-associated genes). Exome sequencing was performed in patients with negative genetic results and a height > + 3 SDs. A total of 55 children with nFTS were enrolled. The median height was + 2.8 SD (2.4-3.2 SD), and the median midparental height was + 0.7 SD (0.4-0.9 SD). Genetic causes of tall stature were identified in 6/55 (11%) children. Specifically, four children had gonosomal aneuploidy (47,XXY [2x], 47,XXX, 48,XXXX), one had a heterozygous complex rearrangement including SHOX gene duplication, and one carried a pathogenic variant in the TGFBR2 gene leading to Loeys-Dietz syndrome. A genetic cause of tall stature was significantly less common in nFTS (11%) than in our previously published cohort with FTS (32%). Conclusion: Cytogenetic abnormalities were the predominant genetic alteration identified in children with nFTS, confirming the justification of karyotype analysis in this cohort. The probability of genetic alterations was greater in children with FTS than in those with nFTS. Our findings suggest that the current guidelines for complex investigation are efficient for children with nFTS but need revision in children with FTS. What is known - what is new • Although tall stature is generally considered beneficial, it can be associated with health risks which need to be recognized in time. Tall stature without intellectual impairment is usually considered to be polygenic. • However, the cause of familial tall stature was monogenic more often than it was thought previously. • Children with non-familial and apparently non-syndromic tall stature have never been systematically investigated. • Monogenic causes of non-familial tall stature were observed in 11% of patients, including a participant with Loeys-Dietz syndrome.
- MeSH
- Chromosome Aberrations * MeSH
- Child MeSH
- Phenotype MeSH
- Genetic Testing MeSH
- Karyotyping MeSH
- Humans MeSH
- Adolescent MeSH
- Growth Disorders * genetics MeSH
- Child, Preschool MeSH
- Short Stature Homeobox Protein MeSH
- Exome Sequencing MeSH
- Body Height * genetics MeSH
- Check Tag
- Child MeSH
- Humans MeSH
- Adolescent MeSH
- Male MeSH
- Child, Preschool MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Comparative Study MeSH
Phase separation forms membraneless compartments, including heterochromatin "domains" and repair foci. Pericentromeric heterochromatin mostly comprises repeated sequences prone to aberrant recombination. In Drosophila cells, "safe" homologous recombination (HR) repair of these sequences requires their relocalization to the nuclear periphery before Rad51 recruitment and strand invasion. How this mobilization initiates is unknown, and the contribution of phase separation is unclear. Here, we show that Nup98 nucleoporin is recruited to repair sites before relocalization by Sec13 or Nup88, and downstream of the Smc5/6 complex and heterochromatin protein 1 (HP1). Remarkably, Nup98 condensates are immiscible with HP1 condensates, and they are required and sufficient to mobilize repair sites and exclude Rad51, thus preventing aberrant recombination while promoting HR repair. Disrupting this pathway results in heterochromatin repair defects and widespread chromosome rearrangements, revealing an "off-pore" role for nucleoporins and phase separation in nuclear dynamics and genome integrity in a multicellular eukaryote.
- MeSH
- Chromosomal Proteins, Non-Histone metabolism genetics MeSH
- Drosophila melanogaster * genetics metabolism MeSH
- DNA Breaks, Double-Stranded MeSH
- Heterochromatin * genetics metabolism MeSH
- Chromobox Protein Homolog 5 MeSH
- Nuclear Pore Complex Proteins * metabolism genetics MeSH
- Cell Cycle Proteins metabolism genetics MeSH
- Drosophila Proteins * metabolism genetics MeSH
- Recombinational DNA Repair * MeSH
- Rad51 Recombinase * metabolism genetics MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
The perception of a voice in the absence of an external auditory source-an auditory verbal hallucination-is a characteristic symptom of schizophrenia. To better understand this phenomenon requires integration of findings across behavioural, functional, and neurochemical levels. We address this with a locally adapted MEGA-PRESS sequence incorporating interleaved unsuppressed water acquisitions, allowing concurrent assessment of behaviour, blood-oxygenation-level-dependent (BOLD) functional changes, Glutamate + Glutamine (Glx), and GABA, synchronised with a cognitive (flanker) task. We acquired data from the anterior cingulate cortex (ACC) of 51 patients with psychosis (predominantly schizophrenia spectrum disorder) and hallucinations, matched to healthy controls. Consistent with the notion of an excitatory/inhibitory imbalance, we hypothesized differential effects for Glx and GABA between groups, and aberrant dynamics in response to task. Results showed impaired task performance, lower baseline Glx and positive association between Glx and BOLD in patients, contrasting a negative correlation in healthy controls. Task-related increases in Glx were observed in both groups, with no significant difference between groups. No significant effects were observed for GABA. These findings suggest that a putative excitatory/inhibitory imbalance affecting inhibitory control in the ACC is primarily observed as tonic, baseline glutamate differences, rather than GABAergic effects or aberrant dynamics in relation to a task.
- MeSH
- Gyrus Cinguli metabolism physiopathology MeSH
- Adult MeSH
- gamma-Aminobutyric Acid * metabolism MeSH
- Glutamine metabolism MeSH
- Hallucinations * metabolism physiopathology MeSH
- Cognition * physiology MeSH
- Glutamic Acid * metabolism MeSH
- Middle Aged MeSH
- Humans MeSH
- Magnetic Resonance Imaging MeSH
- Young Adult MeSH
- Psychotic Disorders * metabolism physiopathology MeSH
- Case-Control Studies MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
Tumor suppressor p53 is a key player in the cell response to DNA damage that suffers by frequent inactivating aberrations. Some of them disturb p53 oligomerization and influence cell decision between proliferation, growth arrest and apoptosis. Active p53 resides mostly in the nucleus, degradation occurs in the cytoplasm. Acute myeloid leukemia (AML)-related mutation of NPM (NPMmut) induces massive mislocalization of p53 to the cytoplasm, which might be related to leukemia initiation. Since both proteins interact and execute their function as oligomers, we investigated the role of perturbed p53 oligomerization in the p53 mislocalization process in live cells by FLIM (fluorescence lifetime imaging microscopy), fluorescence anisotropy imaging (FAIM), fluorescence cross-correlation spectroscopy (FCCS) and immunochemical methods. On a set of fluorescently labeled p53 variants, monomeric R337G and L344P, dimeric L344A, and multimeric D352G and A353S, we correlated their cellular localization, oligomerization and interaction with NPMmut. Interplay between nuclear export signal (NES) and nuclear localization signal (NLS) of p53 was investigated as well. While NLS was found critical for the nuclear p53 localization, NES plays less significant role. We observed cytoplasmic translocation only for multimeric A353S variant with sufficient stability and strong interaction with NPMmut. Less stable multimer D352G and L344A dimer were not translocated, monomeric p53 variants always resided in the nucleus independently of the presence of NPMmut and NES intactness. Oligomeric state of NPMmut is not required for p53 translocation, which happens also in the presence of the nonoligomerizing NPMmut variant. The prominent structural and functional role of the R337 residue is shown.
- MeSH
- Leukemia, Myeloid, Acute * genetics metabolism MeSH
- Cell Nucleus metabolism MeSH
- Cytoplasm metabolism MeSH
- Nuclear Localization Signals metabolism MeSH
- Nuclear Proteins * genetics metabolism MeSH
- Humans MeSH
- Protein Multimerization MeSH
- Mutation * MeSH
- Cell Line, Tumor MeSH
- Tumor Suppressor Protein p53 * metabolism genetics chemistry MeSH
- Nucleophosmin MeSH
- Nuclear Export Signals MeSH
- Protein Transport MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH