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Cell Reports Jun 2024Oligodendrocyte death is common in aging and neurodegenerative disease. In these conditions, dying oligodendrocytes must be efficiently removed to allow remyelination...
Oligodendrocyte death is common in aging and neurodegenerative disease. In these conditions, dying oligodendrocytes must be efficiently removed to allow remyelination and to prevent a feedforward degenerative cascade. Removal of this cellular debris is thought to primarily be carried out by resident microglia. To investigate the cellular dynamics underlying how microglia do this, we use a single-cell cortical demyelination model combined with longitudinal intravital imaging of dual-labeled transgenic mice. Following phagocytosis, single microglia clear the targeted oligodendrocyte and its myelin sheaths in one day via a precise, rapid, and stereotyped sequence. Deletion of the fractalkine receptor, CX3CR1, delays the microglial phagocytosis of the cell soma but has no effect on clearance of myelin sheaths. Unexpectedly, deletion of the phosphatidylserine receptor, MERTK, has no effect on oligodendrocyte or myelin sheath clearance. Thus, separate molecular signals are used to detect, engage, and clear distinct sub-compartments of dying oligodendrocytes to maintain tissue homeostasis.
PubMed: 38935500
DOI: 10.1016/j.celrep.2024.114385 -
Viruses May 2024We previously reported that deletion of a 44-nucleotide element in the 3' untranslated region (UTR) of the Chikungunya virus (CHIKV) genome enhances the virulence of...
We previously reported that deletion of a 44-nucleotide element in the 3' untranslated region (UTR) of the Chikungunya virus (CHIKV) genome enhances the virulence of CHIKV infection in mice. Here, we find that while this 44-nucleotide deletion enhances CHIKV fitness in murine embryonic fibroblasts in a manner independent of the type I interferon response, the same mutation decreases viral fitness in C6/36 mosquito cells. Further, the fitness advantage conferred by the UTR deletion in mammalian cells is maintained in vivo in a mouse model of CHIKV dissemination. Finally, SHAPE-MaP analysis of the CHIKV 3' UTR revealed this 44-nucleotide element forms a distinctive two-stem-loop structure that is ablated in the mutant 3' UTR without altering additional 3' UTR RNA secondary structures.
Topics: Chikungunya virus; Animals; Mice; 3' Untranslated Regions; Chikungunya Fever; Virus Replication; RNA, Viral; Virulence; Cell Line; Fibroblasts; Genetic Fitness; Humans; Sequence Deletion; Nucleic Acid Conformation; Disease Models, Animal
PubMed: 38932154
DOI: 10.3390/v16060861 -
Journal of Personalized Medicine Jun 2024Early-onset colorectal cancer (EOCRC), defined as colorectal cancer in individuals under 50 years of age, has shown an alarming increase in incidence worldwide. We...
Early-onset colorectal cancer (EOCRC), defined as colorectal cancer in individuals under 50 years of age, has shown an alarming increase in incidence worldwide. We report a case of a twenty-four-year-old female with a strong family history of colorectal cancer (CRC) but without an identified underlying genetic predisposition syndrome. Two years after primary surgery and adjuvant chemotherapy, the patient developed new liver lesions. Extensive diagnostic imaging was conducted to investigate suspected liver metastases, ultimately leading to a diagnosis of focal nodular hyperplasia. The young age of the patient has prompted comprehensive genomic and transcriptomic profiling in order to identify potential oncogenic drivers and inform further clinical management of the patient. Besides a number of oncogenic mutations identified in the patient's tumour sample, including KRAS G12D, TP53 R248W and TTN L28470V, we have also identified a homozygous deletion of 24.5 MB on chromosome 8. A multivariate Cox regression analysis of this patient's mutation profile conferred a favourable prognosis when compared with the TCGA COADREAD database. Notably, the identified deletion on chromosome 8 includes the WRN gene, which could contribute to the patient's overall positive response to chemotherapy. The complex clinical presentation, including the need for emergency surgery, early age at diagnosis, strong family history, and unexpected findings on surveillance imaging, necessitated a multidisciplinary approach involving medical, radiation, and surgical oncologists, along with psychological support and reproductive medicine specialists. Molecular profiling of the tumour strongly indicates that patients with complex mutational profile and rare genomic rearrangements require a prolonged surveillance and personalised informed interventions.
PubMed: 38929861
DOI: 10.3390/jpm14060639 -
Journal of Personalized Medicine Jun 2024We aim to verify velopharyngeal sphincter function in 22q11.2 deletion syndrome patients (22q11.2DS) to establish correlations between aerodynamic and perceptual...
OBJECTIVES
We aim to verify velopharyngeal sphincter function in 22q11.2 deletion syndrome patients (22q11.2DS) to establish correlations between aerodynamic and perceptual measures of nasality, and to identify aerodynamic measures differentiating typical from atypical velopharyngeal behavior.
METHODS
Eleven subjects with 22q11.2DS and twenty similar-age control subjects were recruited. The aerodynamic measures were mean Sound Pressure Level, air pressure peak, pressure wave duration, airflow pattern and nasal airflow during the sequence /pi/. The nasality perceptual measures were rhinolalia, rhinophony and nasal air escape.
RESULTS
Airflow patterns and perceptual measures were statistically different in the two groups. Pressure wave duration and air pressure peak were lower in study subjects than in controls. Air pressure peak and nasal airflow were negatively correlated with rhinolalia; pressure wave duration was negatively correlated with nasal air escape and rhinolalia in 22q11.2DS patients.
CONCLUSIONS
This aerodynamic study identified velopharyngeal qualitative and quantitative dysfunctions, suggesting heterogeneous models of velopharyngeal function in syndromic subjects as compared to controls.
PubMed: 38929841
DOI: 10.3390/jpm14060620 -
Antioxidants (Basel, Switzerland) Jun 2024Loss-of-function mutations in the TLDc family of proteins cause a range of severe childhood-onset neurological disorders with common clinical features that include...
Loss-of-function mutations in the TLDc family of proteins cause a range of severe childhood-onset neurological disorders with common clinical features that include cerebellar neurodegeneration, ataxia and epilepsy. Of these proteins, oxidation resistance 1 (OXR1) has been implicated in multiple cellular pathways related to antioxidant function, transcriptional regulation and cellular survival; yet how this relates to the specific neuropathological features in disease remains unclear. Here, we investigate a range of loss-of-function mouse model systems and reveal that constitutive deletion of leads to a rapid and striking neuroinflammatory response prior to neurodegeneration that is associated with lysosomal pathology. We go on to show that neuroinflammation and cell death in knockouts can be completely rescued by the neuronal expression of Oxr1, suggesting that the phenotype is driven by the cell-intrinsic defects of neuronal cells lacking the gene. Next, we generate a ubiquitous, adult inducible knockout of that surprisingly displays rapid-onset ataxia and cerebellar neurodegeneration, establishing for the first time that the distinctive pathology associated with the loss of occurs irrespective of developmental stage. Finally, we describe two new homozygous human pathogenic variants in that cause neurodevelopmental delay, including a novel stop-gain mutation. We also compare functionally two missense human pathogenic mutations in including one newly described here, that cause different clinical phenotypes but demonstrate partially retained neuroprotective activity against oxidative stress. Together, these data highlight the essential role of in modulating neuroinflammatory and lysosomal pathways in the mammalian brain and support the hypothesis that OXR1 protein dosage may be critical for pathological outcomes in disease.
PubMed: 38929124
DOI: 10.3390/antiox13060685 -
International Journal of Molecular... Jun 2024Hereditary breast and ovarian cancer (HBOC) syndrome is a genetic condition that increases the risk of breast cancer by 80% and that of ovarian cancer by 40%. The most...
Hereditary breast and ovarian cancer (HBOC) syndrome is a genetic condition that increases the risk of breast cancer by 80% and that of ovarian cancer by 40%. The most common pathogenic variants (PVs) causing HBOC occur in the gene, with more than 3850 reported mutations in the gene sequence. The prevalence of specific PVs in has increased across populations due to the effect of founder mutations. Therefore, when a founder mutation is identified, it becomes key to improving cancer risk characterization and effective screening protocols. The only founder mutation described in the Mexican population is the deletion of exons 9 to 12 of (), and its description focuses on the gene sequence, but no transcription profiles have been generated for individuals who carry this gene. In this study, we describe the transcription profiles of cancer patients and healthy individuals who were heterozygous for PV by analyzing the differential expression of both alleles compared with the homozygous control group using RT-qPCR, and we describe the isoforms produced by the wild-type and alleles using nanopore long-sequencing. Using the Kruskal-Wallis test, our results showed a similar transcript expression of the wild-type allele between the healthy heterozygous group and the homozygous control group. An association between the recurrence and increased expression of both alleles in HBOC patients was also observed. An analysis of the sequences indicated four wild-type isoforms with diagnostic potential for discerning individuals who carry the PV and identifying which of them has developed cancer.
Topics: Humans; BRCA1 Protein; Female; Alleles; Hereditary Breast and Ovarian Cancer Syndrome; Middle Aged; Genetic Predisposition to Disease; Adult; Founder Effect; Exons; Breast Neoplasms; Heterozygote; Mutation; Mexico; Ovarian Neoplasms; Clinical Relevance
PubMed: 38928478
DOI: 10.3390/ijms25126773 -
International Journal of Molecular... Jun 2024Plants photoreceptors perceive changes in light quality and intensity and thereby regulate plant vegetative growth and reproductive development. By screening a γ...
Plants photoreceptors perceive changes in light quality and intensity and thereby regulate plant vegetative growth and reproductive development. By screening a γ irradiation-induced mutant library of the soybean () cultivar "Dongsheng 7", we identified , a mutant with elongated nodes, yellowed leaves, decreased chlorophyll contents, altered photosynthetic performance, and early maturation. An analysis of bulked DNA and RNA data sampled from a population segregating for , using the BVF-IGV pipeline established in our laboratory, identified a 10 bp deletion in the first exon of the candidate gene . The causative mutation was verified by a variation analysis of over 500 genes in the candidate gene region and an association analysis, performed using two populations segregating for . () is a homolog of in , which encodes a PΦB synthase involved in the biosynthesis of phytochrome. A transcriptome analysis of using the Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed changes in multiple functional pathways, including photosynthesis, gibberellic acid (GA) signaling, and flowering time, which may explain the observed mutant phenotypes. Further studies on the function of GmHY2a and its homologs will help us to understand its profound regulatory effects on photosynthesis, photomorphogenesis, and flowering time.
Topics: Glycine max; Photosynthesis; Exons; Gene Expression Regulation, Plant; Hypocotyl; Sequence Deletion; Plant Proteins; Gibberellins; Gene Expression Profiling; Phenotype
PubMed: 38928189
DOI: 10.3390/ijms25126483 -
International Journal of Molecular... Jun 2024Activation of the transcription factor NF-κB in cardiomyocytes has been implicated in the development of cardiac function deficits caused by diabetes. NF-κB controls...
Activation of the transcription factor NF-κB in cardiomyocytes has been implicated in the development of cardiac function deficits caused by diabetes. NF-κB controls the expression of an array of pro-inflammatory cytokines and chemokines. We recently discovered that the stress response protein regulated in development and DNA damage response 1 (REDD1) was required for increased pro-inflammatory cytokine expression in the hearts of diabetic mice. The studies herein were designed to extend the prior report by investigating the role of REDD1 in NF-κB signaling in cardiomyocytes. REDD1 genetic deletion suppressed NF-κB signaling and nuclear localization of the transcription factor in human AC16 cardiomyocyte cultures exposed to TNFα or hyperglycemic conditions. A similar suppressive effect on NF-κB activation and pro-inflammatory cytokine expression was also seen in cardiomyocytes by knocking down the expression of GSK3β. NF-κB activity was restored in REDD1-deficient cardiomyocytes exposed to hyperglycemic conditions by expression of a constitutively active GSK3β variant. In the hearts of diabetic mice, REDD1 was required for reduced inhibitory phosphorylation of GSK3β at S9 and upregulation of IL-1β and CCL2. Diabetic REDD1 mice developed systolic functional deficits evidenced by reduced ejection fraction. By contrast, REDD1 mice did not exhibit a diabetes-induced deficit in ejection fraction and left ventricular chamber dilatation was reduced in diabetic REDD1 mice, as compared to diabetic REDD1 mice. Overall, the results support a role for REDD1 in promoting GSK3β-dependent NF-κB signaling in cardiomyocytes and in the development of cardiac function deficits in diabetic mice.
Topics: Animals; Myocytes, Cardiac; NF-kappa B; Signal Transduction; Mice; Diabetes Mellitus, Experimental; Transcription Factors; Glycogen Synthase Kinase 3 beta; Humans; Mice, Knockout; Male; Chemokine CCL2; Interleukin-1beta; Mice, Inbred C57BL; Tumor Necrosis Factor-alpha; Phosphorylation; Gene Deletion
PubMed: 38928166
DOI: 10.3390/ijms25126461 -
International Journal of Molecular... Jun 2024The compound 15-deacetylcalonectrin (15-deCAL) is a common pathway intermediate in the biosynthesis of trichothecenes. This tricyclic intermediate is metabolized to...
The compound 15-deacetylcalonectrin (15-deCAL) is a common pathway intermediate in the biosynthesis of trichothecenes. This tricyclic intermediate is metabolized to calonectrin (CAL) by trichothecene 15--acetyltransferase encoded by . Unlike other trichothecene pathway gene mutants, the Δ mutant produces lower amounts of the knocked-out enzyme's substrate 15-deCAL, and instead, accumulates higher quantities of earlier bicyclic intermediate and shunt metabolites. Furthermore, evolutionary studies suggest that may play a role in shaping the chemotypes of trichothecene-producing strains. To better understand the functional role of Tri3p in biosynthesis and evolution, we aimed to develop a method to produce 15-deCAL by using transgenic strains derived from a trichothecene overproducer. Unfortunately, introducing mutant , encoding a catalytically impaired but structurally intact acetylase, did not improve the low 15-deCAL production level of the Δ deletion strain, and the bicyclic products continued to accumulate as the major metabolites of the active-site mutant. These findings are discussed in light of the enzyme responsible for 15-deCAL production in trichothecene biosynthesis machinery. To efficiently produce 15-deCAL, we tested an alternative strategy of using a CAL-overproducing transformant. By feeding a crude CAL extract to a strain that was isolated in this study and capable of specifically deacetylating C-15 acetyl, 15-deCAL was efficiently recovered. The substrate produced in this manner can be used for kinetic investigations of this enzyme and its possible role in chemotype diversification.
Topics: Fusarium; Trichothecenes; Mutation; Acetyltransferases; Fungal Proteins; Biosynthetic Pathways
PubMed: 38928120
DOI: 10.3390/ijms25126414 -
International Journal of Molecular... Jun 2024Ovarian mature teratomas (OMTs) originate from post-meiotic germ cells. Malignant transformation occurs in approximately 1-2% of OMTs; however, sebaceous carcinoma...
Ovarian mature teratomas (OMTs) originate from post-meiotic germ cells. Malignant transformation occurs in approximately 1-2% of OMTs; however, sebaceous carcinoma arising from OMTs is rare. This is the first report of a detailed genomic analysis of sebaceous carcinoma arising from an OMT. A 36-year-old woman underwent evaluation for abdominal tumors and subsequent hysterectomy and salpingo-oophorectomy. Pathologically, a diagnosis of stage IA sebaceous carcinoma arising from an OMT was established. Eight months post-surgery, the patient was alive without recurrence. Immunohistochemically, the tumor was negative for mismatch repair proteins. A nonsense mutation in (p.R306*) and a deletion in were identified. Single nucleotide polymorphisms across all chromosomes displayed a high degree of homozygosity, suggestive of uniparental disomy. Herein, the OMT resulting from the endoreduplication of oocytes underwent a malignant transformation to sebaceous carcinoma via as an early event and as a late event.
Topics: Humans; Female; Adult; Ovarian Neoplasms; Teratoma; Tumor Suppressor Protein p53; Class Ia Phosphatidylinositol 3-Kinase; Adenocarcinoma, Sebaceous; Polymorphism, Single Nucleotide; Cell Transformation, Neoplastic
PubMed: 38928057
DOI: 10.3390/ijms25126351