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1.
J Clin Lab Anal ; 38(7): e25030, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38525916

RESUMO

BACKGROUND: The motor protein dynein is integral to retrograde transport along microtubules and interacts with numerous cargoes through the recruitment of cargo-specific adaptor proteins. This interaction is mediated by dynein light intermediate chain subunits LIC1 (DYNC1LI1) and LIC2 (DYNC1LI2), which govern the adaptor binding and are present in distinct dynein complexes with overlapping and unique functions. METHODS: Using bioinformatics, we analyzed the C-terminal domains (CTDs) of LIC1 and LIC2, revealing similar structural features but diverse post-translational modifications (PTMs). The methylation status of LIC2 and the proteins involved in this modification were examined through immunoprecipitation and immunoblotting analyses. The specific methylation sites on LIC2 were identified through a site-directed mutagenesis analysis, contributing to a deeper understanding of the regulatory mechanisms of the dynein complex. RESULTS: We found that LIC2 is specifically methylated at the arginine 397 residue, a reaction that is catalyzed by protein arginine methyltransferase 1 (PRMT1). CONCLUSIONS: The distinct PTMs of the LIC subunits offer a versatile mechanism for dynein to transport diverse cargoes efficiently. Understanding how these PTMs influence the functions of LIC2, and how they differ from LIC1, is crucial for elucidating the role of dynein-related transport pathways in a range of diseases. The discovery of the arginine 397 methylation site on LIC2 enhances our insight into the regulatory PTMs of dynein functions.


Assuntos
Arginina , Dineínas do Citoplasma , Proteína-Arginina N-Metiltransferases , Proteínas Repressoras , Metilação , Arginina/metabolismo , Arginina/química , Humanos , Dineínas do Citoplasma/metabolismo , Dineínas do Citoplasma/genética , Dineínas do Citoplasma/química , Proteína-Arginina N-Metiltransferases/metabolismo , Proteína-Arginina N-Metiltransferases/genética , Processamento de Proteína Pós-Traducional , Dineínas/metabolismo , Dineínas/genética , Dineínas/química , Sequência de Aminoácidos
2.
Vet J ; 304: 106069, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38281659

RESUMO

Schistosoma reflexum (SR) is a lethal congenital syndrome characterized by U-shaped dorsal retroflexion of the spine and exposure of abdominal viscera. SR is usually associated with severe dystocia. The syndrome is thought to be inherited as a Mendelian trait. We collected a series of 23 SR-affected calves from four breeds (20 Holstein, one Red Danish, one Limousin, one Romagnola) and performed whole-genome sequencing (WGS). WGS was performed on 51 cattle, including 14 cases with parents (trio-based; Group 1) and nine single cases (solo-based; Group 2). Sequencing-based genome-wide association studies with 20 Holstein cases and 154 controls showed no association (above Bonferroni threshold; P-value<3 ×10-09). Assuming a monogenic recessive inheritance, no region of shared homozygosity was observed, suggesting heterogeneity. Alternatively, the presence of possible dominant acting de novo mutations were assessed. In Group 1, heterozygous private variants, absent in both parents, were found in seven cases. These involved the ACTL6A, FLNA, GLG1, IQSEC2, MAST3, MBTPS2, and MLLT1 genes. In addition, heterozygous private variants affecting the genes DYNC1LI1, PPP2R2B, SCAF8, SUGP1, and UBP1 were identified in five cases from Group 2. The detected frameshift and missense variants are predicted to cause haploinsufficiency. Each of these 12 affected genes belong to the class of haploinsufficient loss-of-function genes or are involved in embryonic and pre-weaning lethality or are known to be associated with severe malformation syndromes in humans and/or mice. This study presents for the first time a detailed genomic evaluation of bovine SR, suggesting that independent de novo mutations may explain the sporadic occurrence of SR in cattle.


Assuntos
Doenças dos Bovinos , Doenças dos Roedores , Humanos , Bovinos , Animais , Camundongos , Estudo de Associação Genômica Ampla/veterinária , Linhagem , Síndrome , Fenótipo , Mutação , Actinas/genética , Proteínas Cromossômicas não Histona/genética , Proteínas de Ligação a DNA/genética , Fatores de Troca do Nucleotídeo Guanina/genética , Dineínas do Citoplasma/genética , Proteínas do Tecido Nervoso/genética , Doenças dos Bovinos/genética
3.
J Cell Biol ; 223(3)2024 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-38240798

RESUMO

Cytoplasmic dynein 1 (dynein) is the primary minus end-directed motor protein in most eukaryotic cells. Dynein remains in an inactive conformation until the formation of a tripartite complex comprising dynein, its regulator dynactin, and a cargo adaptor. How this process of dynein activation occurs is unclear since it entails the formation of a three-protein complex inside the crowded environs of a cell. Here, we employed live-cell, single-molecule imaging to visualize and track fluorescently tagged dynein. First, we observed that only ∼30% of dynein molecules that bound to the microtubule (MT) engaged in minus end-directed movement, and that too for a short duration of ∼0.6 s. Next, using high-resolution imaging in live and fixed cells and using correlative light and electron microscopy, we discovered that dynactin and endosomal cargo remained in proximity to each other and to MTs. We then employed two-color imaging to visualize cargo movement effected by single motor binding. Finally, we performed long-term imaging to show that short movements are sufficient to drive cargo to the perinuclear region of the cell. Taken together, we discovered a search mechanism that is facilitated by dynein's frequent MT binding-unbinding kinetics: (i) in a futile event when dynein does not encounter cargo anchored in proximity to the MT, dynein dissociates and diffuses into the cytoplasm, (ii) when dynein encounters cargo and dynactin upon MT binding, it moves cargo in a short run. Several of these short runs are undertaken in succession for long-range directed movement. In conclusion, we demonstrate that dynein activation and cargo capture are coupled in a step that relies on the reduction of dimensionality to enable minus end-directed transport in cellulo and that complex cargo behavior emerges from stochastic motor-cargo interactions.


Assuntos
Dineínas do Citoplasma , Microtúbulos , Imagem Individual de Molécula , Dineínas do Citoplasma/genética , Dineínas do Citoplasma/metabolismo , Complexo Dinactina/metabolismo , Endossomos/metabolismo , Microtúbulos/metabolismo
5.
Seizure ; 116: 119-125, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37903666

RESUMO

OBJECTIVES: The DYNC1H1 variants are associated with abnormal brain morphology and neuromuscular disorders that are accompanied by epilepsy. This study aimed to explore the relationship between DYNC1H1 variants and epilepsy. MATERIALS AND METHODS: Trios-based whole-exome sequencing was performed on patients with epilepsy. Previously reported epilepsy-related DYNC1H1 variants were systematically reviewed to analyse genotype-phenotype correlation. RESULTS: The DYNC1H1 variants were identified in four unrelated cases of infant-onset epilepsy, including two de novo and two biallelic variants. Two patients harbouring de novo missense variants located in the stem and stalk domains presented with refractory epilepsies, whereas two patients harbouring biallelic variants located in the regions between functional domains had mild epilepsy with infrequent focal seizures and favourable outcomes. One patient presented with pachygyria and neurodevelopmental abnormalities, and the other three patients presented with normal development. These variants have no or low frequencies in the Genome Aggregation Database. All the missense variants were predicted to be damaging using silico tools. Previously reported epilepsy-related variants were monoallelic variants, mainly de novo missense variants, and all the patients presented with severe epileptic phenotypes or developmental delay and malformations of cortical development. Epilepsy-related variants were clustered in the dimerization and stalk domains, and generalized epilepsy-associated variants were distributed in the stem domain. CONCLUSION: This study suggested that DYNC1H1 variants are potentially associated with infant-onset epilepsy without neurodevelopmental disorders, expanding the phenotypic spectrum of DYNC1H1. The genotype-phenotype correlation helps to understand the underlying mechanisms of phenotypic variation.


Assuntos
Epilepsia Generalizada , Epilepsia , Transtornos do Neurodesenvolvimento , Lactente , Humanos , Mutação , Epilepsia/genética , Transtornos do Neurodesenvolvimento/genética , Mutação de Sentido Incorreto , Fenótipo , Dineínas do Citoplasma/genética
6.
Nat Struct Mol Biol ; 30(9): 1357-1364, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37620585

RESUMO

Cytoplasmic dynein-1 transports intracellular cargo towards microtubule minus ends. Dynein is autoinhibited and undergoes conformational changes to form an active complex that consists of one or two dynein dimers, the dynactin complex, and activating adapter(s). The Lissencephaly 1 gene, LIS1, is genetically linked to the dynein pathway from fungi to mammals and is mutated in people with the neurodevelopmental disease lissencephaly. Lis1 is required for active dynein complexes to form, but how it enables this is unclear. Here, we present a structure of two yeast dynein motor domains with two Lis1 dimers wedged in-between. The contact sites between dynein and Lis1 in this structure, termed 'Chi,' are required for Lis1's regulation of dynein in Saccharomyces cerevisiae in vivo and the formation of active human dynein-dynactin-activating adapter complexes in vitro. We propose that this structure represents an intermediate in dynein's activation pathway, revealing how Lis1 relieves dynein's autoinhibited state.


Assuntos
Lissencefalias Clássicas e Heterotopias Subcorticais em Banda , Dineínas do Citoplasma , Animais , Humanos , Dineínas do Citoplasma/genética , Dineínas , Transporte Biológico , Citoesqueleto , Complexo Dinactina , Oligonucleotídeos , Mamíferos
7.
Turk J Pediatr ; 65(3): 531-535, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37395972

RESUMO

BACKGROUND: Spinal muscular atrophy with lower extremity predominance (SMA-LED) is an autosomal dominant disorder. Since SMA-LED affects lower motor neurons, the disease is characterized by weakness and atrophy of lower limb muscles. We present a familial case series of SMA-LED with upper motor neuron signs associated with a rare variant in DYNC1H1. CASE: The index case was referred to Pediatric Neurology at the age of two and half years, due to delayed mobility. The child was diagnosed with congenital vertical talus at birth, which was managed with serial bilateral casting and surgery. The delayed mobility was initially attributed to lower limb weakness secondary to prolonged periods of immobilization from casting of his lower limbs. He had a striking waddling gait and proximal muscle weakness on neurological assessment. He had lower motor neuron signs predominantly in his lower limbs that were in keeping with SMA-LED. Surprisingly, he also demonstrated a brisk crossed adductor response that was not in keeping with an isolated primary neuro-muscular disorder and suggested a mixed upper and lower motor neuron pathology. The inherited neuropathy gene panel revealed a heterozygous sequence change in the DYNC1H1 gene which was present in all affected family members. CONCLUSIONS: We present the first report of a familial case series of SMA-LED with upper motor neuron signs associated with an extremely rare variant in DYNC1H1: c.1808A > T (p.Glu603Val). As per the American College of Medical Genetics and Genomics (ACMG) guidelines for variant classification, we would recommend that this variant be reclassified as `Likely Pathogenic` due to matching 1 moderate (PM1-PM6) and ≥4 supporting (PP1-PP5) criteria in the reported case series.


Assuntos
Dineínas do Citoplasma , Atrofia Muscular Espinal , Humanos , Masculino , Dineínas do Citoplasma/genética , Extremidade Inferior , Neurônios Motores/patologia , Atrofia Muscular Espinal/diagnóstico , Atrofia Muscular Espinal/genética , Fenótipo , Pré-Escolar
8.
J Matern Fetal Neonatal Med ; 36(1): 2205985, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37100787

RESUMO

Short-rib thoracic dysplasia 3 with or without polydactyly (OMIM # 613091) represents a clinical spectrum encompassing a heterogeneous group of skeletal dysplasias associated with homozygous or compound heterozygous mutations of DYNC2H1. We describe the case of a couple with two consecutive therapeutic abortions due to a diagnosis of short-rib thoracic dysplasia mutations. In the first pregnancy, the diagnosis has been made at 21 weeks. In the second one, an accurate and early ultrasound examination allowed a diagnosis at 12 weeks. DYNC2H1 mutations were confirmed in both cases. In this report, we underline the importance of an ultrasound evaluation at the end of the first trimester of pregnancy in the detection of early signs of skeletal dysplasias. An early prenatal diagnosis of a short-rib skeletal dysplasia, such as for other severe skeletal dysplasias, is critical to offer a couple the chance of a weighted, informed, and less traumatic decision about the continuation of the pregnancy.


Assuntos
Osteocondrodisplasias , Síndrome de Costela Curta e Polidactilia , Gravidez , Feminino , Humanos , Síndrome de Costela Curta e Polidactilia/diagnóstico , Síndrome de Costela Curta e Polidactilia/genética , Diagnóstico Pré-Natal , Ultrassonografia , Osteocondrodisplasias/diagnóstico por imagem , Osteocondrodisplasias/genética , Costelas , Ultrassonografia Pré-Natal , Dineínas do Citoplasma/genética
9.
J Cell Sci ; 136(5)2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36861883

RESUMO

The microtubule minus-end-directed motility of cytoplasmic dynein 1 (dynein), arguably the most complex and versatile cytoskeletal motor, is harnessed for diverse functions, such as long-range organelle transport in neuronal axons and spindle assembly in dividing cells. The versatility of dynein raises a number of intriguing questions, including how is dynein recruited to its diverse cargo, how is recruitment coupled to activation of the motor, how is motility regulated to meet different requirements for force production and how does dynein coordinate its activity with that of other microtubule-associated proteins (MAPs) present on the same cargo. Here, these questions will be discussed in the context of dynein at the kinetochore, the supramolecular protein structure that connects segregating chromosomes to spindle microtubules in dividing cells. As the first kinetochore-localized MAP described, dynein has intrigued cell biologists for more than three decades. The first part of this Review summarizes current knowledge about how kinetochore dynein contributes to efficient and accurate spindle assembly, and the second part describes the underlying molecular mechanisms and highlights emerging commonalities with dynein regulation at other subcellular sites.


Assuntos
Dineínas , Cinetocoros , Proteínas Associadas aos Microtúbulos/genética , Dineínas do Citoplasma/genética , Axônios
10.
BMC Med Genomics ; 16(1): 47, 2023 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-36882741

RESUMO

BACKGROUND: Spinal muscular atrophy, lower extremity predominant (SMALED) is a type of non-5q spinal muscular atrophy characterised by weakness and atrophy of lower limb muscles without sensory abnormalities. SMALED1 can be caused by dynein cytoplasmic 1 heavy chain 1 (DYNC1H1) gene variants. However, the phenotype and genotype of SMALED1 may overlap with those of other neuromuscular diseases, making it difficult to diagnose clinically. Additionally, bone metabolism and bone mineral density (BMD) in patients with SMALED1 have never been reported. METHODS: We investigated a Chinese family in which 5 individuals from 3 generations had lower limb muscle atrophy and foot deformities. Clinical manifestations and biochemical and radiographic indices were analysed, and mutational analysis was performed by whole-exome sequencing (WES) and Sanger sequencing. RESULTS: A novel mutation in exon 4 of the DYNC1H1 gene (c.587T > C, p.Leu196Ser) was identified in the proband and his affected mother by WES. Sanger sequencing confirmed that the proband and 3 affected family members were carriers of this mutation. As leucine is a hydrophobic amino acid and serine is hydrophilic, the hydrophobic interaction resulting from mutation of amino acid residue 196 could influence the stability of the DYNC1H1 protein. Leg muscle magnetic resonance imaging of the proband revealed severe atrophy and fatty infiltration, and electromyographic recordings showed chronic neurogenic impairment of the lower extremities. Bone metabolism markers and BMD of the proband were all within normal ranges. None of the 4 patients had experienced fragility fractures. CONCLUSION: This study identified a novel DYNC1H1 mutation and expands the spectrum of phenotypes and genotypes of DYNC1H1-related disorders. This is the first report of bone metabolism and BMD in patients with SMALED1.


Assuntos
Dineínas do Citoplasma , Atrofia Muscular Espinal , Humanos , Aminoácidos , Atrofia , Dineínas do Citoplasma/genética , População do Leste Asiático , Extremidade Inferior , Músculos , Atrofia Muscular Espinal/genética , Mutação de Sentido Incorreto
11.
Neurobiol Dis ; 180: 106085, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36933672

RESUMO

Dynein heavy chain (DYNC1H1) mutations can either lead to severe cerebral cortical malformations, or alternatively may be associated with the development of spinal muscular atrophy with lower extremity predominance (SMA-LED). To assess the origin of such differences, we studied a new Dync1h1 knock-in mouse carrying the cortical malformation p.Lys3334Asn mutation. Comparing with an existing neurodegenerative Dync1h1 mutant (Legs at odd angles, Loa, p.Phe580Tyr/+), we assessed Dync1h1's roles in cortical progenitor and especially radial glia functions during embryogenesis, and assessed neuronal differentiation. p.Lys3334Asn /+ mice exhibit reduced brain and body size. Embryonic brains show increased and disorganized radial glia: interkinetic nuclear migration occurs in mutants, however there are increased basally positioned cells and abventricular mitoses. The ventricular boundary is disorganized potentially contributing to progenitor mislocalization and death. Morphologies of mitochondria and Golgi apparatus are perturbed in vitro, with different effects also in Loa mice. Perturbations of neuronal migration and layering are also observed in p.Lys3334Asn /+ mutants. Overall, we identify specific developmental effects due to a severe cortical malformation mutation in Dync1h1, highlighting the differences with a mutation known instead to primarily affect motor function.


Assuntos
Dineínas , Atrofia Muscular Espinal , Humanos , Camundongos , Animais , Dineínas/genética , Dineínas do Citoplasma/genética , Dineínas do Citoplasma/metabolismo , Atrofia Muscular Espinal/genética , Tamanho do Órgão , Mutação/genética , Encéfalo/metabolismo , Células-Tronco
12.
J Cell Biol ; 222(5)2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36946995

RESUMO

Cytoplasmic dynein-driven movement of chromosomes during prophase I of mammalian meiosis is essential for synapsis and genetic exchange. Dynein connects to chromosome telomeres via KASH5 and SUN1 or SUN2, which together span the nuclear envelope. Here, we show that KASH5 promotes dynein motility in vitro, and cytosolic KASH5 inhibits dynein's interphase functions. KASH5 interacts with a dynein light intermediate chain (DYNC1LI1 or DYNC1LI2) via a conserved helix in the LIC C-terminal, and this region is also needed for dynein's recruitment to other cellular membranes. KASH5's N-terminal EF-hands are essential as the interaction with dynein is disrupted by mutation of key calcium-binding residues, although it is not regulated by cellular calcium levels. Dynein can be recruited to KASH5 at the nuclear envelope independently of dynactin, while LIS1 is essential for dynactin incorporation into the KASH5-dynein complex. Altogether, we show that the transmembrane protein KASH5 is an activating adaptor for dynein and shed light on the hierarchy of assembly of KASH5-dynein-dynactin complexes.


Assuntos
Proteínas de Ciclo Celular , Dineínas do Citoplasma , Complexo Dinactina , Proteínas Associadas aos Microtúbulos , Animais , Cálcio/metabolismo , Dineínas do Citoplasma/genética , Dineínas do Citoplasma/metabolismo , Complexo Dinactina/genética , Complexo Dinactina/metabolismo , Mamíferos/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Membrana Nuclear/genética , Membrana Nuclear/metabolismo , Telômero/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo
13.
Eur J Hum Genet ; 31(4): 479-484, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36599940

RESUMO

Deleterious variants of DYNC2H1 gene are associated with a wide spectrum of skeletal ciliopathies (SC). We used targeted parallel sequencing to analyze 25 molecularly unsolved families with different SCs. Deleterious DYNC2H1 variants were found in six sporadic patients and two monozygotic (MZ) twins. Clinical diagnoses included short rib-polydactyly type 3 in two cases, and asphyxiating thoracic dystrophy (ATD) in one case. Remarkably, clinical diagnosis fitted with EvC, mixed ATD/EvC and short rib-polydactyly/EvC phenotypes in three sporadic patients and the MZ twins. EvC/EvC-like features always occurred in compound heterozygotes sharing a previously unreported splice site change (c.6140-5A>G) or compound heterozygotes for two missense variants. These results expand the DYNC2H1 mutational repertoire and its clinical spectrum, suggesting that EvC may be occasionally caused by DYNC2H1 variants presumably acting as hypomorphic alleles.


Assuntos
Ciliopatias , Dineínas do Citoplasma , Síndrome de Ellis-Van Creveld , Polidactilia , Humanos , Ciliopatias/diagnóstico , Ciliopatias/genética , Dineínas do Citoplasma/genética , Síndrome de Ellis-Van Creveld/diagnóstico , Síndrome de Ellis-Van Creveld/genética , Mutação , Polidactilia/genética
14.
Methods Mol Biol ; 2623: 157-173, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36602685

RESUMO

Recombinant protein expression has been key to studying dynein's mechanochemistry and structure-function relationship. To gain further insight into the energy-converting mechanisms and interactions with an increasing variety of dynein cargos and regulators, rapid expression and purification of a variety of dynein proteins and fragments are important. Here we describe transient expression of cytoplasmic dynein in HEK293 cells and fast small-scale purification for high-throughput protein engineering. Mammalian cell expression might be generally considered to be a laborious process, but with recent technology and some simple inexpensive custom-built labware, dynein expression and purification from mammalian cells can be fast and easy.


Assuntos
Dineínas do Citoplasma , Dineínas , Animais , Humanos , Dineínas do Citoplasma/genética , Dineínas/genética , Dineínas/metabolismo , Células HEK293 , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Engenharia de Proteínas , Microtúbulos/metabolismo , Mamíferos/metabolismo
15.
Biochim Biophys Acta Mol Basis Dis ; 1869(4): 166645, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36682603

RESUMO

Retinal photoreceptors execute phototransduction functions and require an efficient system for the transport of materials (e.g. proteins and lipids) from inner segments to outer segments. Cytoplasmic dynein 1 is a minus-end-directed microtubule motor and participates in cargo transport in the cytoplasm. However, the roles of dynein 1 motor in photoreceptor cargo transport and retinal development are still ambiguous. In our present study, the light intermediate chain protein DLIC1 (encoded by dync1li1), links activating adaptors to bind diverse cargos in the dynein 1 motor, was depleted using CRISPR-Cas9 technology in zebrafish. The dync1li1-/- zebrafish displayed progressive degeneration of retinal cone photoreceptors, especially blue cones. The retinal rods were not affected in dync1li1-/- zebrafish. Knockout of DLIC1 resulted in abnormal expression and localization of cone opsins in dync1li1-/- retinas. TUNEL staining suggested that apoptosis was induced after aberrant accumulation of cone opsins in photoreceptors of dync1li1-/- zebrafish. Instead of Rab11 transport, Rab8 transport was disturbed in dync1li1-/- retinas. Our data demonstrate that DLIC1 is required for function maintenance and survival of cone photoreceptors, and hint at an essential role of the cytoplasmic dynein 1 motor in photoreceptor cargo transport.


Assuntos
Opsinas dos Cones , Dineínas do Citoplasma , Células Fotorreceptoras Retinianas Cones , Animais , Opsinas dos Cones/metabolismo , Dineínas do Citoplasma/genética , Dineínas do Citoplasma/metabolismo , Dineínas/genética , Dineínas/metabolismo , Células Fotorreceptoras Retinianas Cones/metabolismo , Peixe-Zebra/genética , Peixe-Zebra/metabolismo
16.
Zhonghua Er Ke Za Zhi ; 61(2): 154-158, 2023 Feb 02.
Artigo em Chinês | MEDLINE | ID: mdl-36720598

RESUMO

Objective: To investigate the clinical features and gene variation characteristics of children with dynein cytoplasmic 1 heavy chain 1 (DYNC1H1) gene associated spinal muscular atrophy with lower extremity predominant (SMALED) 1. Methods: The clinical data of 4 SMALED1 children admitted to Peking University First Hospital from December 2018 to May 2021, who were found to have pathogenic variation of DYNC1H1 gene through genetic testing, except for other genes known to be related to motor retardation, were retrospectively summarized to analyze the phenotype and genotype characteristics. Results: There were 3 males and 1 female. The age of onset was 1 year, 1 day, 1 day and 4 months, respectively. The age of diagnosis was 4 years and 10 months, 9 months, 5 years and 9 months, and 3 years and 1 month, respectively. The clinical manifestations were muscle weakness and muscular atrophy of lower limbs, 2 cases with foot deformity, 1 case with early non progressive joint contracture, 1 case with hip dislocation and 1 case with mental retardation. De novo heterozygous missense variations in DYNC1H1 gene were found in all 4 children. According to the rating of American College of medical genetics and genomics, they were all possible pathogenic and pathogenic variations, with p.R598C, p.P776L, p.Y1109D variations had been reported, and p.I1086R variation had not been reported. Conclusions: For those with unexplained lower limb muscle weakness, muscle atrophy, joint contracture and foot deformity, upper limb motor ability related retention, with or without mental retardation, as well as the motor ability progresses slowly, it is necessary to consider the possibility of SMALED1 and the detection of DYNC1H1 gene when necessary.


Assuntos
Contratura , Deficiência Intelectual , Atrofia Muscular Espinal , Feminino , Masculino , Humanos , Estudos Retrospectivos , Atrofia Muscular Espinal/genética , Extremidade Inferior , Debilidade Muscular , Atrofia Muscular , Dineínas do Citoplasma/genética
17.
J Cell Sci ; 136(5)2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36218033

RESUMO

Size homeostasis is a fundamental process in biology and is particularly important for large cells such as neurons. We previously proposed a motor-dependent length-sensing mechanism wherein reductions in microtubule motor levels would be expected to accelerate neuronal growth, and validated this prediction in dynein heavy chain 1 Loa mutant (Dync1h1Loa) sensory neurons. Here, we describe a new mouse model with a conditional deletion allele of exons 24 and 25 in Dync1h1. Homozygous Islet1-Cre-mediated deletion of Dync1h1 (Isl1-Dync1h1-/-), which deletes protein from the motor and sensory neurons, is embryonic lethal, but heterozygous animals (Isl1-Dync1h1+/-) survive to adulthood with ∼50% dynein expression in targeted cells. Isl1-Dync1h1+/- sensory neurons reveal accelerated growth, as previously reported in Dync1h1Loa neurons. Moreover, Isl1-Dync1h1+/- mice show mild impairments in gait, proprioception and tactile sensation, similar to what is seen in Dync1h1Loa mice, confirming that specific aspects of the Loa phenotype are due to reduced dynein levels. Isl1-Dync1h1+/- mice also show delayed recovery from peripheral nerve injury, likely due to reduced injury signal delivery from axonal lesion sites. Thus, conditional deletion of Dync1h1 exons 24 and 25 enables targeted studies of the role of dynein in neuronal growth.


Assuntos
Dineínas do Citoplasma , Dineínas , Camundongos , Animais , Dineínas/genética , Dineínas/metabolismo , Dineínas do Citoplasma/genética , Dineínas do Citoplasma/metabolismo , Alelos , Mutação , Células Receptoras Sensoriais/metabolismo
18.
Dev Med Child Neurol ; 65(4): 534-543, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36175372

RESUMO

AIM: To explore the phenotypic spectrum and refine the genotype-phenotype correlation of DYNC1H1-related epilepsy. METHOD: The clinical data of 15 patients with epilepsy in our cohort and 50 patients with epilepsy from 24 published studies with the DYNC1H1 variants were evaluated. RESULTS: In our cohort, 13 variants were identified from 15 patients (seven males, eight females). Twelve variants were de novo and seven were new. Age at seizure onset ranged from 3 months to 4 years 5 months (median age 1 year). Common seizure types were epileptic spasms, focal seizures, tonic seizures, and myoclonic seizures. Mild-to-severe developmental delay was present in all patients. Six patients were diagnosed with West syndrome and one was diagnosed with epileptic encephalopathy with continuous spikes and waves during slow sleep (CSWS). Collectively, in our cohort and published studies, 17% had ophthalmic diseases, 31% of variants were located in the stalk domain, and 92% patients with epilepsy had a malformation of cortical development (MCD). INTERPRETATION: The phenotypes of DYNC1H1-related epilepsy included multiple seizure types; the most common epileptic syndrome was West syndrome. CSWS is a new phenotype of DYNC1H1-related epilepsy. One-third of the variants in patients with epilepsy were located in the stalk domain. Most patients had a MCD and developmental delay. WHAT THIS PAPER ADDS: Nearly 40% of patients with DYNC1H1 variants had epilepsy. Ninety-two percent of patients with DYNC1H1-related epilepsy had malformation of cortical development. More than 10% of patients with DYNC1H1-related epilepsy were diagnosed with West syndrome. Continuous spikes and waves during slow sleep could be a new phenotype of DYNC1H1 variants. One-third of the variants in patients with epilepsy were located in the stalk domain.


Assuntos
Epilepsia , Espasmos Infantis , Masculino , Feminino , Humanos , Espasmos Infantis/genética , Mutação , Epilepsia/genética , Convulsões/genética , Estudos de Associação Genética , Eletroencefalografia , Dineínas do Citoplasma/genética
19.
Artigo em Inglês | MEDLINE | ID: mdl-36442996

RESUMO

Biallelic pathogenic variants in DYNC2H1 are the cause of short-rib thoracic dysplasia type III with or without polydactyly (OMIM #613091), a skeletal ciliopathy characterized by thoracic hypoplasia due to short ribs. In this report, we review the case of a patient who was admitted to the Neonatal Intensive Care Unit (NICU) of Indiana University Health (IUH) for respiratory support after experiencing respiratory distress secondary to a small, narrow chest causing restrictive lung disease. Additional phenotypic features include postaxial polydactyly, short proximal long bones, and ambiguous genitalia were noted. Exome sequencing (ES) revealed a maternally inherited likely pathogenic variant c.10322C > T p.(Leu3448Pro) in the DYNC2H1 gene. However, there was no variant found on the paternal allele. Microarray analysis to detect deletion or duplication in DYNC2H1 was normal. Therefore, there was insufficient evidence to establish a molecular diagnosis. To further explore the data and perform additional investigations, the patient was subsequently enrolled in the Undiagnosed Rare Disease Clinic (URDC) at Indiana University School of Medicine (IUSM). The investigators at the URDC performed a reanalysis of the ES raw data, which revealed a paternally inherited DYNC2H1 deep-intronic variant c.10606-14A > G predicted to create a strong cryptic acceptor splice site. Additionally, the RNA sequencing of fibroblasts demonstrated partial intron retention predicted to cause a premature stop codon and nonsense-mediated mRNA decay (NMD). Droplet digital RT-PCR (RT-ddPCR) showed a drastic reduction by 74% of DYNCH2H1 mRNA levels. As a result, the intronic variant was subsequently reclassified as likely pathogenic resulting in a definitive clinical and genetic diagnosis for this patient. Reanalysis of ES and fibroblast mRNA experiments confirmed the pathogenicity of the splicing variants to supplement critical information not revealed in original ES or CMA reports. The NICU and URDC collaboration ended the diagnostic odyssey for this family; furthermore, its importance is emphasized by the possibility of prenatally diagnosing the mother's current pregnancy.


Assuntos
Polidactilia , Síndrome de Costela Curta e Polidactilia , Feminino , Humanos , Recém-Nascido , Gravidez , Dineínas do Citoplasma/genética , Sequenciamento do Exoma , Mutação , Costelas , RNA Mensageiro , Síndrome de Costela Curta e Polidactilia/diagnóstico , Síndrome de Costela Curta e Polidactilia/genética
20.
Biomed Res Int ; 2022: 7992981, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36212719

RESUMO

Background: Periodontitis is considered to be the leading cause of tooth loss in adults, and it interacts with some serious systemic diseases. Periodontal basic therapy is the cornerstone of periodontal disease treatment and long-term maintenance and has a positive impact on the treatment of systemic diseases. Aim: To explore the potential gene targets of periodontitis therapies by bioinformatics method. Methods: We analyzed the expression database (GSE6751) downloaded from the Gene Expression Omnibus (GEO) with weighted gene coexpression network analysis (WGCNA) to confirm the functional gene modules. Pathway enrichment network analyses the key genes in functional modules and verified the candidate genes from the samples in peripheral blood sources of GSE43525. Moreover, we confirmed the expression of target protein in the periodontal tissues of experimental periodontitis-afflicted mice using western blotting. Results: The functional gene modules were found to have biological processes, and ARRB2, BIRC3, CD14, DYNLL1, FCER1G, FCGR1A, FCGR2B, FGR, HCK, and PRKCD were screened as candidates' genes in functional modules. The 921 DEG from GSE43525 and 418 DEG is from the green module of GSE6751 and identified AMICA1, KDELR1, DHRS7B, LMNB1, CTSA, S100A12, and FCGR1A as target genes. Finally, FCGR1A (CD64) was confirmed as the key gene that affects periodontal treatment. Western blot analysis showed an increasing trend in the expression level of FCGR1A protein in the periodontal tissues of experimental periodontitis mice compared to normal mice. Conclusions: FCGR1A (CD64) may be a key gene target for periodontal therapy in patients with periodontitis and other systemic diseases.


Assuntos
Biologia Computacional , Periodontite , Animais , Dineínas do Citoplasma/genética , Perfilação da Expressão Gênica/métodos , Redes Reguladoras de Genes/genética , Camundongos , Periodontite/genética , Receptores de Peptídeos/genética , Proteína S100A12/genética
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