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Genetics in Medicine : Official Journal... Apr 2024Neurodevelopmental disorders exhibit clinical and genetic heterogeneity, ergo manifest dysfunction in components of diverse cellular pathways; the precise pathomechanism...
PURPOSE
Neurodevelopmental disorders exhibit clinical and genetic heterogeneity, ergo manifest dysfunction in components of diverse cellular pathways; the precise pathomechanism for the majority remains elusive.
METHODS
We studied 5 affected individuals from 3 unrelated families manifesting global developmental delay, postnatal microcephaly, and hypotonia. We used exome sequencing and prioritized variants that were subsequently characterized using immunofluorescence, immunoblotting, pulldown assays, and RNA sequencing.
RESULTS
We identified biallelic variants in ZFTRAF1, encoding a protein of yet unknown function. Four affected individuals from 2 unrelated families segregated 2 homozygous frameshift variants in ZFTRAF1, whereas, in the third family, an intronic splice site variant was detected. We investigated ZFTRAF1 at the cellular level and signified it as a nucleocytoplasmic protein in different human cell lines. ZFTRAF1 was completely absent in the fibroblasts of 2 affected individuals. We also identified 110 interacting proteins enriched in mRNA processing and autophagy-related pathways. Based on profiling of autophagy markers, patient-derived fibroblasts show irregularities in the protein degradation process.
CONCLUSION
Thus, our findings suggest that biallelic variants of ZFTRAF1 cause a severe neurodevelopmental disorder.
PubMed: 38641995
DOI: 10.1016/j.gim.2024.101143 -
PLoS Neglected Tropical Diseases Apr 2024Zika virus (ZIKV), an arbovirus from the Flaviviridae family, is the causative agent of Zika fever, a mild and frequent oligosymptomatic disease in humans. Nonetheless,...
Zika virus (ZIKV), an arbovirus from the Flaviviridae family, is the causative agent of Zika fever, a mild and frequent oligosymptomatic disease in humans. Nonetheless, on rare occasions, ZIKV infection can be associated with Guillain-Barré Syndrome (GBS), and severe congenital complications, such as microcephaly. The oligosymptomatic disease, however, presents symptoms that are quite similar to those observed in infections caused by other frequent co-circulating arboviruses, including dengue virus (DENV). Moreover, the antigenic similarity between ZIKV and DENV, and even with other members of the Flaviviridae family, complicates serological testing due to the high cross-reactivity of antibodies. Here, we designed, produced in a prokaryotic expression system, and purified three multiepitope proteins (ZIKV-1, ZIKV-2, and ZIKV-3) for differential diagnosis of Zika. The proteins were evaluated as antigens in ELISA tests for the detection of anti-ZIKV IgG using ZIKV- and DENV-positive human sera. The recombinant proteins were able to bind and detect anti-ZIKV antibodies without cross-reactivity with DENV-positive sera and showed no reactivity with Chikungunya virus (CHIKV)- positive sera. ZIKV-1, ZIKV-2, and ZIKV-3 proteins presented 81.6%, 95%, and 66% sensitivity and 97%, 96%, and 84% specificity, respectively. Our results demonstrate the potential of the designed and expressed antigens in the development of specific diagnostic tests for the detection of IgG antibodies against ZIKV, especially in regions with the circulation of multiple arboviruses.
Topics: Humans; Zika Virus Infection; Zika Virus; Dengue Virus; Dengue; Epitopes; Antibodies, Viral; Immunoglobulin G; Arboviruses; Chikungunya Fever
PubMed: 38635656
DOI: 10.1371/journal.pntd.0012100 -
Parasites & Vectors Apr 2024Toxoplasma gondii, an obligate intracellular parasitic protozoa, infects approximately 30% of the global population. Contracting T. gondii at the primary infection of...
Inhibition of Foxp3 expression in the placenta of mice infected intraperitoneally by toxoplasma gondii tachyzoites: insights into the PPARγ/miR-7b-5p/Sp1 signaling pathway.
BACKGROUND
Toxoplasma gondii, an obligate intracellular parasitic protozoa, infects approximately 30% of the global population. Contracting T. gondii at the primary infection of the mother can result in neonatal microcephaly, chorioretinitis, hydrocephalus, or mortality. Our previous study indicated that pregnant mice infected with T. gondii displayed a decrease in both the number and the suppressive ability of regulatory T cells, accompanied by the reduced Forkhead box P3 (Foxp3). Numerous studies have proved that microRNAs (miRNAs) are implicated in T. gondii infection, but there is meager evidence on the relationship between alterations of miRNAs and downregulation of Foxp3 induced by T. gondii.
METHODS
Quantitative reverse transcription polymerase chain reaction was utilized to detect the transcriptions of miRNAs and Foxp3. Protein blotting and immunofluorescence were used to detect the expressions of Foxp3 and related transcription factors. The structure of mouse placenta was observed by hematoxylin and eosin (HE) staining. To examine the activity of miR-7b promoter and whether miR-7b-5p targets Sp1 to suppress Foxp3 expression, we constructed recombinant plasmids containing the full-length/truncated/mutant miR-7b promoter sequence or wildtype/mutant of Sp1 3' untranslated region (3' UTR) to detect the fluorescence activity in EL4 cells.
RESULTS
In T. gondii-infected mice, miR-7b transcription was significantly elevated, while Foxp3 expression was decreased in the placenta. In vitro, miR-7b mimics downregulated Foxp3 expression, whereas its inhibitors significantly upregulated Foxp3 expression. miR-7b promoter activity was elevated upon the stimulation of T. gondii antigens, which was mitigated by co-transfection of mutant miR-7b promoter lacking peroxisome proliferator-activated receptor γ (PPARγ) target sites. Additionally, miR-7b mimics diminished Sp1 expression, while miR-7b inhibitors elevated its expression. miR-7b mimics deceased the fluorescence activity of Sp1 3' untranslated region (3' UTR), but it failed to impact the fluorescence activity upon the co-transfection of mutant Sp1 3' UTR lacking miR-7b target site.
CONCLUSIONS
T. gondii infection and antigens promote miR-7b transcription but inhibit Foxp3 protein and gene levels. T. gondii antigens promote miR-7b promoter activity by a PPARγ-dependent mechanism. miR-7b directly binds to Sp1 3' UTR to repress Sp1 expression. Understanding the regulatory functions by which T. gondii-induced miR-7b suppresses Foxp3 expression can provide new perspectives for the possible therapeutic avenue of T. gondii-induced adverse pregnancy outcomes.
Topics: Animals; Female; Mice; Pregnancy; 3' Untranslated Regions; Forkhead Transcription Factors; MicroRNAs; Placenta; PPAR gamma; Signal Transduction; Toxoplasma; Sp1 Transcription Factor; Toxoplasmosis
PubMed: 38632598
DOI: 10.1186/s13071-024-06262-0 -
Frontiers in Pediatrics 2024Galloway-Mowat syndrome (GAMOS) is a rare genetic disease characterized by early-onset nephrotic syndrome and microcephaly with central nervous system abnormalities....
BACKGROUND
Galloway-Mowat syndrome (GAMOS) is a rare genetic disease characterized by early-onset nephrotic syndrome and microcephaly with central nervous system abnormalities. Pathogenic variants in genes encoding kinase, endopeptidase, and other proteins of small size (KEOPS) complex subunits cause GAMOS. The subunit (TP53RK binding protein) has been reported in only two patients with GAMOS with homozygous missense variants.
CLINICAL REPORT
Herein, we described a three-year-old male with GAMOS. He exhibited developmental delay, developmental regression, microcephaly, distinctive facial features, skeletal abnormalities, and epilepsy. Brain magnetic resonance imaging revealed progressive brain atrophy, delayed myelination, T2-hypointense signals in the thalamus, and multiple intracranial abnormal signals on diffusion-weighted imaging. He presented with relapsing nephrotic proteinuria exacerbated by upper respiratory tract infections and progressive renal function decline. Exome sequencing identified compound heterozygous missense and frameshift variants in : c.224dup, p.(Ser76IlefsTer3) and c.247C>T, p.(Leu83Phe).
CONCLUSIONS
Our study supports that pathogenic variants cause KEOPS complex-related GAMOS.
PubMed: 38628357
DOI: 10.3389/fped.2024.1360867 -
Biochemical and Biophysical Research... Jun 2024The DHCR7 enzyme converts 7-DHC into cholesterol. Mutations in DHCR7 can block cholesterol production, leading to abnormal accumulation of 7-DHC and causing...
The DHCR7 enzyme converts 7-DHC into cholesterol. Mutations in DHCR7 can block cholesterol production, leading to abnormal accumulation of 7-DHC and causing Smith-Lemli-Opitz syndrome (SLOS). SLOS is an autosomal recessive disorder characterized by multiple malformations, including microcephaly, intellectual disability, behavior reminiscent of autism, sleep disturbances, and attention-deficit/hyperactivity disorder (ADHD)-like hyperactivity. Although 7-DHC affects neuronal differentiation in ex vivo experiments, the precise mechanism of SLOS remains unclear. We generated Dhcr7 deficient (dhcr7) zebrafish that exhibited key features of SLOS, including microcephaly, decreased neural stem cell pools, and behavioral phenotypes similar to those of ADHD-like hyperactivity. These zebrafish demonstrated compromised myelination, synaptic anomalies, and neurotransmitter imbalances. The axons of the dhcr7 zebrafish showed increased lysosomes and attenuated autophagy, suggesting that autophagy-related neuronal homeostasis is disrupted.
Topics: Animals; Autophagy; Axons; Cholesterol; Lysosomes; Neurogenesis; Neurons; Oxidoreductases Acting on CH-CH Group Donors; Smith-Lemli-Opitz Syndrome; Zebrafish; Zebrafish Proteins
PubMed: 38626530
DOI: 10.1016/j.bbrc.2024.149932 -
European Journal of Medical Genetics Jun 2024ADH5/ALDH2 deficiency is a rare inherited syndrome characterized by short stature, microcephaly, delayed mental development, and hematopoietic dysfunction and has... (Review)
Review
ADH5/ALDH2 deficiency is a rare inherited syndrome characterized by short stature, microcephaly, delayed mental development, and hematopoietic dysfunction and has recently been proposed as a disease paradigm. Acute and severe presentations include aplastic anemia, myelodysplastic syndrome, or leukemia, requiring bone marrow transplantation during childhood. Conversely, non-hematological manifestations may exhibit a prolonged and nonspecific clinical trajectory, with growth failure and developmental delay, most of which are often overlooked, particularly in patients with milder symptoms. Here, we describe the clinical course of a girl with a wide spectrum of clinical presentations, including nonspecific hematopoietic disorders, growth retardation, mild developmental delay, amblyopia, hemophagocytic lymphohistiocytosis, and verruca vulgaris, culminating in a genetic diagnosis of AMeD syndrome at 12 years of age. We also summarized the clinical manifestations of previously reported cases of AMeD syndrome. Cumulatively, 13 females and 5 males have been documented, with a cardinal triad of symptoms, aplastic anemia, short stature, and intellectual disability. Additional characteristic observations included pigmentary deposition in approximately half of the cases and skeletal difficulties in one-quarter. We propose that early diagnosis of patients who exhibit relatively mild phenotypes of skin or skeletal lesions is important for managing and improving the quality of life of patients with AMeD syndrome.
Topics: Humans; Female; Phenotype; Child; Aldehyde Dehydrogenase, Mitochondrial; Developmental Disabilities; Male; Microcephaly; Intellectual Disability; Anemia, Aplastic
PubMed: 38614309
DOI: 10.1016/j.ejmg.2024.104939 -
Cells Mar 2024Zika virus (ZIKV) infection and pathogenesis are linked to the disruption of neurogenesis, congenital Zika syndrome and microcephaly by affecting neural progenitor...
The ZIKV NS5 Protein Aberrantly Alters the Tubulin Cytoskeleton, Induces the Accumulation of Autophagic p62 and Affects IFN Production: HDAC6 Has Emerged as an Anti-NS5/ZIKV Factor.
Zika virus (ZIKV) infection and pathogenesis are linked to the disruption of neurogenesis, congenital Zika syndrome and microcephaly by affecting neural progenitor cells. Nonstructural protein 5 (NS5) is the largest product encoded by ZIKV-RNA and is important for replication and immune evasion. Here, we studied the potential effects of NS5 on microtubules (MTs) and autophagy flux, together with the interplay of NS5 with histone deacetylase 6 (HDAC6). Fluorescence microscopy, biochemical cell-fractionation combined with the use of HDAC6 mutants, chemical inhibitors and RNA interference indicated that NS5 accumulates in nuclear structures and strongly promotes the acetylation of MTs that aberrantly reorganize in nested structures. Similarly, NS5 accumulates the p62 protein, an autophagic-flux marker. Therefore, NS5 alters events that are under the control of the autophagic tubulin-deacetylase HDAC6. HDAC6 appears to degrade NS5 by autophagy in a deacetylase- and BUZ domain-dependent manner and to control the cytoplasmic expression of NS5. Moreover, NS5 inhibits RNA-mediated RIG-I interferon (IFN) production, resulting in greater activity when autophagy is inhibited (i.e., effect correlated with NS5 stability). Therefore, it is conceivable that NS5 contributes to cell toxicity and pathogenesis, evading the IFN-immune response by overcoming HDAC6 functions. HDAC6 has emerged as an anti-ZIKV factor by targeting NS5.
Topics: Humans; Zika Virus; Histone Deacetylase 6; Zika Virus Infection; Tubulin; Microtubules; RNA; Autophagy
PubMed: 38607037
DOI: 10.3390/cells13070598 -
Cureus Mar 2024Johanson-Blizzard syndrome (JBS) is a rare hereditary autosomal recessive disorder caused by a mutation in the ubiquitin protein ligase E3 component n-recognin 1 (UBR1)...
Johanson-Blizzard syndrome (JBS) is a rare hereditary autosomal recessive disorder caused by a mutation in the ubiquitin protein ligase E3 component n-recognin 1 (UBR1) gene. This syndrome is characterized by the following typical clinical features: hypoplasia or aplasia of the alae nasi, congenital scalp defects, sensorineural hearing loss, hypothyroidism, growth retardation, psychomotor retardation, imperforate anus, genitourinary anomalies, and atypical hair patterns. Here, we describe a case of a 12-year-old girl with JBS of consanguineous parents. During the last trimester of pregnancy, a congenital abnormality affecting the nose was detected. Immediately after birth, the clinical examination revealed dysmorphic features in the form of hypoplastic alae nasi, microcephaly, mild hypotelorism, and cutis aplasia on the scalp. The genetic testing of the patient showed a novel sequence change mutation of the UBR1 gene (1bp duplication causing a frameshift), while both parents were carriers for this mutation. Moreover, a diagnosis of pancreatic insufficiency and subclinical hypothyroidism was made based on clinical presentation and laboratory results. The patient was started on pancreatic enzyme replacement therapy and fat-soluble vitamins, minerals, and antioxidant syrup. Further assessment revealed hypotonia, growth impairment, delay in reaching developmental milestones, and bilateral profound sensorineural hearing loss, which was managed with bilateral cochlear implantation. In addition, the patient underwent multiple craniofacial reconstructive surgeries. This case report highlights the importance of early diagnosis and multidisciplinary care of patients with JBS.
PubMed: 38606259
DOI: 10.7759/cureus.55969 -
EMBO Reports May 2024Microcephaly is a common feature in inherited bone marrow failure syndromes, prompting investigations into shared pathways between neurogenesis and hematopoiesis. To...
Microcephaly is a common feature in inherited bone marrow failure syndromes, prompting investigations into shared pathways between neurogenesis and hematopoiesis. To understand this association, we studied the role of the microcephaly gene Mcph1 in hematological development. Our research revealed that Mcph1-knockout mice exhibited congenital macrocytic anemia due to impaired terminal erythroid differentiation during fetal development. Anemia's cause is a failure to complete cell division, evident from tetraploid erythroid progenitors with DNA content exceeding 4n. Gene expression profiling demonstrated activation of the p53 pathway in Mcph1-deficient erythroid precursors, leading to overexpression of Cdkn1a/p21, a major mediator of p53-dependent cell cycle arrest. Surprisingly, fetal brain analysis revealed hypertrophied binucleated neuroprogenitors overexpressing p21 in Mcph1-knockout mice, indicating a shared pathophysiological mechanism underlying both erythroid and neurological defects. However, inactivating p53 in Mcph1 mice failed to reverse anemia and microcephaly, suggesting that p53 activation in Mcph1-deficient cells resulted from their proliferation defect rather than causing it. These findings shed new light on Mcph1's function in fetal hematopoietic development, emphasizing the impact of disrupted cell division on neurogenesis and erythropoiesis - a common limiting pathway.
Topics: Animals; Erythropoiesis; Microcephaly; Mice; Mice, Knockout; Cell Cycle Proteins; Tumor Suppressor Protein p53; Cyclin-Dependent Kinase Inhibitor p21; Cytoskeletal Proteins; Mutation; Anemia, Macrocytic; Cell Differentiation; Erythroid Precursor Cells
PubMed: 38605277
DOI: 10.1038/s44319-024-00123-8 -
Oxford Open Neuroscience 2024PRDM16 is a dynamic transcriptional regulator of various stem cell niches, including adipocytic, hematopoietic, cardiac progenitors, and neural stem cells. PRDM16 has...
PRDM16 is a dynamic transcriptional regulator of various stem cell niches, including adipocytic, hematopoietic, cardiac progenitors, and neural stem cells. PRDM16 has been suggested to contribute to 1p36 deletion syndrome, one of the most prevalent subtelomeric microdeletion syndromes. We report a patient with a nonsense mutation in the PRDM16 coding sequence, accompanied by lissencephaly and microcephaly features. Human stem cells were genetically modified to mimic this mutation, generating cortical organoids that exhibited altered cell cycle dynamics. RNA sequencing of cortical organoids at day 32 unveiled changes in cell adhesion and WNT-signaling pathways. ChIP-seq of PRDM16 identified binding sites in postmortem human fetal cortex, indicating the conservation of PRDM16 binding to developmental genes in mice and humans, potentially at enhancer sites. A shared motif between PRDM16 and LHX2 was identified and further examined through comparison with LHX2 ChIP-seq data from mice. These results suggested a collaborative partnership between PRDM16 and LHX2 in regulating a common set of genes and pathways in cortical radial glia cells, possibly via their synergistic involvement in cortical development.
PubMed: 38595939
DOI: 10.1093/oons/kvae001