Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.622
Filtrar
1.
Am J Hum Genet ; 107(2): 293-310, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32707087

RESUMO

We identified ten persons in six consanguineous families with distal arthrogryposis (DA) who had congenital contractures, scoliosis, and short stature. Exome sequencing revealed that each affected person was homozygous for one of two different rare variants (c.470G>T [p.Cys157Phe] or c.469T>C [p.Cys157Arg]) affecting the same residue of myosin light chain, phosphorylatable, fast skeletal muscle (MYLPF). In a seventh family, a c.487G>A (p.Gly163Ser) variant in MYLPF arose de novo in a father, who transmitted it to his son. In an eighth family comprised of seven individuals with dominantly inherited DA, a c.98C>T (p.Ala33Val) variant segregated in all four persons tested. Variants in MYLPF underlie both dominant and recessively inherited DA. Mylpf protein models suggest that the residues associated with dominant DA interact with myosin whereas the residues altered in families with recessive DA only indirectly impair this interaction. Pathological and histological exam of a foot amputated from an affected child revealed complete absence of skeletal muscle (i.e., segmental amyoplasia). To investigate the mechanism for this finding, we generated an animal model for partial MYLPF impairment by knocking out zebrafish mylpfa. The mylpfa mutant had reduced trunk contractile force and complete pectoral fin paralysis, demonstrating that mylpf impairment most severely affects limb movement. mylpfa mutant muscle weakness was most pronounced in an appendicular muscle and was explained by reduced myosin activity and fiber degeneration. Collectively, our findings demonstrate that partial loss of MYLPF function can lead to congenital contractures, likely as a result of degeneration of skeletal muscle in the distal limb.


Assuntos
Artrogripose/genética , Músculo Esquelético/patologia , Anormalidades Musculoesqueléticas/genética , Mutação/genética , Cadeias Leves de Miosina/genética , Adolescente , Sequência de Aminoácidos , Animais , Criança , Contratura/genética , Extremidades/patologia , Feminino , Humanos , Masculino , Miosinas/genética , Linhagem , Adulto Jovem , Peixe-Zebra/genética
2.
Proc Natl Acad Sci U S A ; 117(27): 15666-15672, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32571956

RESUMO

Muscle contraction depends on the cyclical interaction of myosin and actin filaments. Therefore, it is important to understand the mechanisms of polymerization and depolymerization of muscle myosins. Muscle myosin 2 monomers exist in two states: one with a folded tail that interacts with the heads (10S) and one with an unfolded tail (6S). It has been thought that only unfolded monomers assemble into bipolar and side-polar (smooth muscle myosin) filaments. We now show by electron microscopy that, after 4 s of polymerization in vitro in both the presence (smooth muscle myosin) and absence of ATP, skeletal, cardiac, and smooth muscle myosins form tail-folded monomers without tail-head interaction, tail-folded antiparallel dimers, tail-folded antiparallel tetramers, unfolded bipolar tetramers, and small filaments. After 4 h, the myosins form thick bipolar and, for smooth muscle myosin, side-polar filaments. Nonphosphorylated smooth muscle myosin polymerizes in the presence of ATP but with a higher critical concentration than in the absence of ATP and forms only bipolar filaments with bare zones. Partial depolymerization in vitro of nonphosphorylated smooth muscle myosin filaments by the addition of MgATP is the reverse of polymerization.


Assuntos
Citoesqueleto de Actina/química , Miosina Tipo II/química , Miosinas/química , Miosinas de Músculo Liso/química , Citoesqueleto de Actina/genética , Citoesqueleto de Actina/ultraestrutura , Animais , Galinhas , Microscopia Eletrônica , Miosina Tipo II/genética , Miosina Tipo II/ultraestrutura , Miosinas/genética , Miosinas/ultraestrutura , Fosforilação/genética , Polimerização , Conformação Proteica , Dobramento de Proteína , Multimerização Proteica/genética , Desdobramento de Proteína , Miosinas de Músculo Liso/genética , Miosinas de Músculo Liso/ultraestrutura
3.
Nat Commun ; 11(1): 3200, 2020 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-32581239

RESUMO

mTOR activation is essential and sufficient to cause polycystic kidneys in Tuberous Sclerosis Complex (TSC) and other genetic disorders. In disease models, a sharp increase of proliferation and cyst formation correlates with a dramatic loss of oriented cell division (OCD). We find that OCD distortion is intrinsically due to S6 kinase 1 (S6K1) activation. The concomitant loss of S6K1 in Tsc1-mutant mice restores OCD but does not decrease hyperproliferation, leading to non-cystic harmonious hyper growth of kidneys. Mass spectrometry-based phosphoproteomics for S6K1 substrates revealed Afadin, a known component of cell-cell junctions required to couple intercellular adhesions and cortical cues to spindle orientation. Afadin is directly phosphorylated by S6K1 and abnormally decorates the apical surface of Tsc1-mutant cells with E-cadherin and α-catenin. Our data reveal that S6K1 hyperactivity alters centrosome positioning in mitotic cells, affecting oriented cell division and promoting kidney cysts in conditions of mTOR hyperactivity.


Assuntos
Divisão Celular , Cinesina/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Miosinas/metabolismo , Doenças Renais Policísticas/patologia , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Animais , Linhagem Celular , Cinesina/genética , Camundongos , Camundongos Mutantes , Mutação , Miosinas/genética , Fosforilação , Doenças Renais Policísticas/genética , Doenças Renais Policísticas/metabolismo , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Transdução de Sinais , Esclerose Tuberosa/genética , Esclerose Tuberosa/metabolismo , Esclerose Tuberosa/patologia , Proteína 1 do Complexo Esclerose Tuberosa/genética , Proteína 1 do Complexo Esclerose Tuberosa/metabolismo
4.
Adv Exp Med Biol ; 1239: 317-330, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32451864

RESUMO

Hearing loss is both genetically and clinically heterogeneous, and pathogenic variants of over a hundred different genes are associated with this common neurosensory disorder. A relatively large number of these "deafness genes" encode myosin super family members. The evidence that pathogenic variants of human MYO3A, MYO6, MYO7A, MYO15A, MYH14 and MYH9 are associated with deafness ranges from moderate to definitive. Additional evidence for the involvement of these six myosins for normal hearing also comes from animal models, usually mouse or zebra fish, where mutations of these genes cause hearing loss and from biochemical, physiological and cell biological studies of their roles in the inner ear. This chapter focuses on these six genes for which evidence of a causative role in deafness is substantial.


Assuntos
Surdez , Audição , Miosinas , Animais , Surdez/genética , Audição/genética , Humanos , Mutação , Miosinas/genética
5.
PLoS Genet ; 16(4): e1008758, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32324733

RESUMO

Left-Right (LR) asymmetry is essential for organ positioning, shape and function. Myosin 1D (Myo1D) has emerged as an evolutionary conserved chirality determinant in both Drosophila and vertebrates. However, the molecular interplay between Myo1D and the actin cytoskeleton underlying symmetry breaking remains poorly understood. To address this question, we performed a dual genetic screen to identify new cytoskeletal factors involved in LR asymmetry. We identified the conserved actin nucleator DAAM as an essential factor required for both dextral and sinistral development. In the absence of DAAM, organs lose their LR asymmetry, while its overexpression enhances Myo1D-induced de novo LR asymmetry. These results show that DAAM is a limiting, LR-specific actin nucleator connecting up Myo1D with a dedicated F-actin network important for symmetry breaking.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Padronização Corporal , Proteínas de Drosophila/metabolismo , Citoesqueleto de Actina/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Drosophila , Proteínas de Drosophila/genética , Miosinas/genética , Miosinas/metabolismo
6.
PLoS One ; 15(4): e0232116, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32343719

RESUMO

Myosin XXI (Myo21) is a novel class of myosin present in all kinetoplastid parasites, such as Trypanosoma and Leishmania. This protein in Leishmania promastigotes is predominantly localized to the proximal region of the flagellum, and is involved in the flagellum assembly, cell motility and intracellular vesicle transport. As Myo21 contains two ubiquitin associated (UBA)-like domains (UBLD) in its amino acid sequence, we considered it of interest to analyze the role of these domains in the intracellular distribution and functions of this protein in Leishmania cells. In this context, we created green fluorescent protein (GFP)-conjugates of Myo21 constructs lacking one of the two UBLDs at a time or both the UBLDs as well as GFP-conjugates of only the two UBLDs and Myo21 tail lacking the two UBLDs and separately expressed them in the Leishmania cells. Our results show that unlike Myo21-GFP, Myo21-GFP constructs lacking either one or both the UBLDs failed to concentrate and co-distribute with actin in the proximal region of the flagellum. Nevertheless, the GFP conjugate of only the two UBLDs was found to predominantly localize to the flagellum base. Additionally, the cells that expressed only one or both the UBLDs-deleted Myo21-GFP constructs possessed shorter flagellum and displayed slower motility, compared to Myo21-GFP expressing cells. Further, the intracellular vesicle transport and cell growth were severely impaired in the cells that expressed both the UBLDs deleted Myo21-GFP construct, but in contrast, virtually no effect was observed on the intracellular vesicle transport and growth in the cells that expressed single UBLD deleted mutant proteins. Moreover, the observed slower growth of both the UBLDs-deleted Myo21-GFP expressing cells was primarily due to delayed G2/M phase caused by aberrant nuclear and daughter cell segregation during their cell division process. These results taken together clearly reveal that the presence of UBLDs in Myo21 are essentially required for its predominant localization to the flagellum base, and perhaps also in its involvement in the flagellum assembly and cell division. Possible role of UBLDs in involvement of Myo21 during Leishmania flagellum assembly and cell cycle is discussed.


Assuntos
Flagelos/metabolismo , Leishmania donovani/fisiologia , Miosinas/química , Miosinas/metabolismo , Actinas/metabolismo , Ciclo Celular , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Leishmania donovani/crescimento & desenvolvimento , Leishmania donovani/metabolismo , Miosinas/genética , Domínios Proteicos , Proteínas de Protozoários/metabolismo , Proteínas Recombinantes/metabolismo , Deleção de Sequência , Vesículas Transportadoras/metabolismo , Ubiquitina/metabolismo
7.
J Anim Sci ; 98(4)2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32249920

RESUMO

Smooth muscle cells (SMCs) play an important role in physiology and production in farm animals such as pigs. Here, we report the generation of a pig SMC line. Our original objective was to establish an enteroendocrine cell line from the pig ileum epithelium through lentiviral transduction of the Simian Virus (SV) 40 large T antigen. However, an initial expression analysis of marker genes in nine cell clones revealed that none of them were enteroendocrine cells or absorptive enterocytes, goblet cells, or Paneth cells, some of the major cell types existing in the ileum epithelium. A more detailed characterization of one clone named PIC7 by RNA-seq showed that these cells expressed many of the known smooth muscle-specific or -enriched genes, including smooth muscle actin alpha 2, calponin 1, calponin 3, myosin heavy chain 11, myosin light chain kinase, smoothelin, tenascin C, transgelin, tropomyosin 1, and tropomyosin 2. Both quantitative PCR and RNA-seq analyses showed that the PIC7 cells had a high expression of mRNA for smooth muscle actin gamma 2, also known as enteric smooth muscle actin. A Western blot analysis confirmed the expression of SV40 T antigen in the PIC7 cells. An immunohistochemical analysis demonstrated the expression of smooth muscle actin alpha 2 filaments in the PIC7 cells. A collagen gel contraction assay showed that the PIC7 cells were capable of both spontaneous contraction and contraction in response to serotonin stimulation. We conclude that the PIC7 cells are derived from an enteric SMC from the pig ileum. These cells may be a useful model for studying the cellular and molecular physiology of pig enteric SMCs. Because pigs are similar to humans in anatomy and physiology, the PIC7 cells may be also used as a model for human intestinal SMCs.


Assuntos
Suínos/fisiologia , Actinas/genética , Animais , Proteínas de Ligação ao Cálcio/genética , Linhagem Celular , Íleo/fisiologia , Proteínas dos Microfilamentos/genética , Proteínas Musculares/genética , Músculo Liso/fisiologia , Miócitos de Músculo Liso/fisiologia , Miosinas/genética , Especificidade de Órgãos , RNA Mensageiro/genética , Suínos/genética , Tenascina/genética , Tropomiosina/genética
8.
Gene ; 742: 144542, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32184166

RESUMO

Homozygous loss-of-function variants in MYO18B have been associated with congenital myopathy, facial dysmorphism and Klippel-Feil anomaly. So far, only four patients have been reported. Comprehensive description of new cases that help to highlight recurrent features and to further delineate the phenotypic spectrum are still missing. We present the fifth case of MYO18B-associated disease in a newborn male patient. Trio exome sequencing identified the previously unreported homozygous nonsense variant c.6433C>T, p.(Arg2145*) in MYO18B (NM_032608.5). While most phenotypic features of our patient align with previously reported cases, we describe the prenatal features for the first time. Taking the phenotypic description of our patient into account, we propose that the core phenotype comprises a severe congenital myopathy with feeding difficulties in infancy and characteristic dysmorphic features.


Assuntos
Anormalidades Craniofaciais/genética , Síndrome de Klippel-Feil/genética , Hipotonia Muscular/genética , Miosinas/genética , Proteínas Supressoras de Tumor/genética , Idade de Início , Consanguinidade , Anormalidades Craniofaciais/diagnóstico , Análise Mutacional de DNA , Humanos , Lactente , Síndrome de Klippel-Feil/classificação , Síndrome de Klippel-Feil/diagnóstico , Mutação com Perda de Função , Masculino , Hipotonia Muscular/diagnóstico , Linhagem , Sequenciamento Completo do Exoma
9.
Proc Natl Acad Sci U S A ; 117(14): 7799-7802, 2020 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-32205434

RESUMO

Cytoskeletons are self-organized networks based on polymerized proteins: actin, tubulin, and driven by motor proteins, such as myosin, kinesin, and dynein. Their positive Darwinian evolution enables them to approach optimized functionality (self-organized criticality). Dynein has three distinct titled subunits, but how these units connect to function as a molecular motor is mysterious. Dynein binds to tubulin through two coiled coil stalks and a stalk head. The energy used to alter the head binding and propel cargo along tubulin is supplied by ATP at a ring 1,500 amino acids away. Here, we show how many details of this extremely distant interaction are explained by water waves quantified by thermodynamic scaling. Water waves have shaped all proteins throughout positive Darwinian evolution, and many aspects of long-range water-protein interactions are universal (described by self-organized criticality). Dynein water waves resembling tsunami produce nearly optimal energy transport over 1,500 amino acids along dynein's one-dimensional peptide backbone. More specifically, this paper identifies many similarities in the function and evolution of dynein compared to other cytoskeleton proteins such as actin, myosin, and tubulin.


Assuntos
Trifosfato de Adenosina/genética , Citoesqueleto/genética , Dineínas/genética , Evolução Molecular , Actinas , Sequência de Aminoácidos/genética , Animais , Fenômenos Biofísicos , Aptidão Genética/genética , Cinesina/genética , Microtúbulos/genética , Miosinas/genética , Conformação Proteica , Tubulina (Proteína)/genética
10.
Int J Mol Sci ; 21(4)2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32093159

RESUMO

Late 19th-century cytologists observed tiny oil drops in shoot parenchyma and seeds, but it was discovered only in 1972 that they were bound by a half unit-membrane. Later, it was found that lipid bodies (LBs) arise from the endoplasmic reticulum. Seeds are known to be packed with static LBs, coated with the LB-specific protein OLEOSIN. As shown here, apices of Populus tremula x P. tremuloides also express OLEOSIN genes and produce potentially mobile LBs. In developing buds, PtOLEOSIN (PtOLE) genes were upregulated, especially PtOLE6, concomitant with LB accumulation. To investigate LB mobility and destinations, we transformed Arabidopsis with PtOLE6-eGFP. We found that PtOLE6-eGFP fusion protein co-localized with Nile Red-stained LBs in all cell types. Moreover, PtOLE6-eGFP-tagged LBs targeted plasmodesmata, identified by the callose marker aniline blue. Pharmacological experiments with brefeldin, cytochalasin D, and oryzalin showed that LB-trafficking requires F-actin, implying involvement of myosin motors. In a triple myosin-XI knockout (xi-k/1/2), transformed with PtOLE6-eGFP, trafficking of PtOLE6-eGFP-tagged LBs was severely impaired, confirming that they move on F-actin, motorized by myosin XIs. The data reveal that LBs and OLEOSINs both function in proliferating apices and buds, and that directional trafficking of LBs to plasmodesmata requires the actomyosin system.


Assuntos
Actinas/metabolismo , Gotículas Lipídicas/metabolismo , Miosinas/metabolismo , Proteínas de Plantas/metabolismo , Plasmodesmos/metabolismo , Populus/metabolismo , Actinas/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Transporte Biológico Ativo/fisiologia , Miosinas/genética , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Plasmodesmos/genética , Populus/genética
11.
Int J Mol Sci ; 21(4)2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32069889

RESUMO

It is generally believed that during muscle contraction, myosin heads (M) extending from myosin filament attaches to actin filaments (A) to perform power stroke, associated with the reaction, A-M-ADP-Pi → A-M + ADP + Pi, so that myosin heads pass through the state of A-M, i.e., rigor A-M complex. We have, however, recently found that: (1) an antibody to myosin head, completely covering actin-binding sites in myosin head, has no effect on Ca2+-activated tension in skinned muscle fibers; (2) skinned fibers exhibit distinct tension recovery following ramp-shaped releases (amplitude, 0.5% of Lo; complete in 5 ms); and (3) EDTA, chelating Mg ions, eliminate the tension recovery in low-Ca rigor fibers but not in high-Ca rigor fibers. These results suggest that A-M-ADP myosin heads in high-Ca rigor fibers have dynamic properties to produce the tension recovery following ramp-shaped releases, and that myosin heads do not pass through rigor A-M complex configuration during muscle contraction. To obtain information about the structural changes in A-M-ADP myosin heads during the tension recovery, we performed X-ray diffraction studies on high-Ca rigor skinned fibers subjected to ramp-shaped releases. X-ray diffraction patterns of the fibers were recorded before and after application of ramp-shaped releases. The results obtained indicate that during the initial drop in rigor tension coincident with the applied release, rigor myosin heads take up applied displacement by tilting from oblique to perpendicular configuration to myofilaments, and after the release myosin heads appear to rotate around the helical structure of actin filaments to produce the tension recovery.


Assuntos
Citoesqueleto de Actina/genética , Actinas/genética , Contração Muscular/fisiologia , Miosinas/genética , Citoesqueleto de Actina/química , Citoesqueleto de Actina/ultraestrutura , Actinas/ultraestrutura , Difosfato de Adenosina/metabolismo , Animais , Sítios de Ligação/genética , Cálcio/metabolismo , Ácido Edético/metabolismo , Humanos , Contração Muscular/genética , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/ultraestrutura , Miosinas/química , Miosinas/ultraestrutura , Ligação Proteica/genética , Coelhos , Difração de Raios X
12.
J Nanobiotechnology ; 18(1): 32, 2020 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-32070333

RESUMO

Gold nanoparticles (GNPs) are one of the most widely used nanomaterials in various fields. Especially, the unique chemical and physical properties make them as the promising candidates in drug target identification, unfortunately, little is known about their application in parasites. In this paper, GNPs were employed as new solid support to identify drug targets of natural bioactive compound arctigenin (ARG) against fish monogenean parasite Gyrodactylus kobayashi. Before target identification, GNPs with ARG on the surface showed the ability to enter the live parasites even the nucleus or mitochondria, which made the bound compounds capable of contacting directly with target proteins located anywhere of the parasites. At the same time, chemically modified compound remained the anthelminthic efficacy against G. kobayashii. The above results both provide assurance on the reliability of using GNPs for drug target-binding specificity. Subsequently, by interrogating the cellular proteome in parasite lysate, myosin-2 and UNC-89 were identified as the potential direct target proteins of ARG in G. kobayashii. Moreover, results of RNA-seq transcriptomics and iTRAQ proteomics indicated that myosin-2 expressions were down-regulated after ARG bath treatment both in transcript and protein levels, but for UNC-89, only in mRNA level. Myosin-2 is an important structural muscle protein expressed in helminth tegument and its identification as our target will enable further inhibitor optimization towards future drug discovery. Furthermore, our findings demonstrate the power of GNPs to be readily applied to other parasite drugs of unknown targets, facilitating more broadly therapeutic drug design in any pathogen or disease model.


Assuntos
Furanos/metabolismo , Ouro/química , Lignanas/metabolismo , Nanopartículas Metálicas/química , Platelmintos/parasitologia , Proteoma/metabolismo , Animais , Transporte Biológico , Descoberta de Drogas , Peixes , Regulação da Expressão Gênica/efeitos dos fármacos , Mitocôndrias/metabolismo , Estrutura Molecular , Miosinas/genética , Miosinas/metabolismo , Ligação Proteica , Proteômica , RNA Mensageiro/efeitos dos fármacos , Reprodutibilidade dos Testes , Relação Estrutura-Atividade , Propriedades de Superfície
13.
BMC Med Genet ; 21(1): 1, 2020 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-31898538

RESUMO

BACKGROUND: Hearing loss (HL) represents the most common congenital sensory impairment with an incidence of 1-5 per 1000 live births. Non-syndromic hearing loss (NSHL) is an isolated finding that is not part of any other disorder accounting for 70% of all genetic hearing loss cases. METHODS: In the current study, we reported a polygenic mode of inheritance in an NSHL consanguineous family using exome sequencing technology and we evaluated the possible effect of the detected single nucleotide variants (SNVs) using in silico methods. RESULTS: Two bi-allelic SNVs were detected in the affected patients; a MYO15A (. p.V485A) variant, and a novel MITF (p.P338L) variant. Along with these homozygous mutations, we detected two heterozygous variants in well described hearing loss genes (MYO7A and MYH14). The novel MITF p. Pro338Leu missense mutation was predicted to change the protein structure and function. CONCLUSION: A novel MITF mutation along with a previously described MYO15A mutation segregate with an autosomal recessive non-syndromic HL case with a post-lingual onset. The findings highlight the importance of carrying whole exome sequencing for a comprehensive assessment of HL genetic heterogeneity.


Assuntos
Heterogeneidade Genética , Perda Auditiva Neurossensorial/genética , Fator de Transcrição Associado à Microftalmia/genética , Miosinas/genética , Idade de Início , Alelos , Criança , Feminino , Predisposição Genética para Doença , Perda Auditiva Neurossensorial/fisiopatologia , Heterozigoto , Homozigoto , Humanos , Masculino , Herança Multifatorial/genética , Linhagem , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Sequenciamento Completo do Exoma
14.
BMJ Case Rep ; 12(11)2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31791989

RESUMO

Neonatal conjugated hyperbilirubinemia is a diagnostic challenge. A full term, small for gestational age boy presented with cholestasis, hypoglycemia, hyperferritinemia and severe bilateral deafness. Diagnostic work-up revealed two hereditary diseases: alpha-1-antitrypsin deficiency (PI*ZZ genotype) and autosomal recessive deafness type 3 (compound heterozygous MYO15A gene mutation). In addition, we found late hypoglycemia on full enteral feeding which complicated this case. Hyperferritinemia is an uncommon finding in newborn cholestasis without liver failure.


Assuntos
Colestase/diagnóstico , Perda Auditiva Neurossensorial/diagnóstico , Hipoglicemia/diagnóstico , Distúrbios do Metabolismo do Ferro/diagnóstico , Deficiência de alfa 1-Antitripsina/diagnóstico , Colestase/genética , Diagnóstico Diferencial , Ferritinas/sangue , Perda Auditiva Neurossensorial/genética , Humanos , Hipoglicemia/genética , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional , Distúrbios do Metabolismo do Ferro/genética , Miosinas/genética , Deficiência de alfa 1-Antitripsina/genética
15.
J Pak Med Assoc ; 69(11): 1632-1636, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31740869

RESUMO

OBJECTIVE: To link congenital hearing loss with known loci to establish a platform for future research. Methods: The cross-sectional study was conducted from February 2016 to March 2017 in Bannu, Khyber Pakhtunkhwa, Pakistan, and comprised families with Pashtun ethnicity having at least 2 individuals suffering from congenital hearing loss. Deoxyribonucleic acid from whole blood samples was extracted by salting-out method. Amplification was done through touchdown polymerase chain reaction to see any possible linkage to already reported deafness loci. Linkage analysis was carried out using microsatellite markers for each locus. Genotyping of the samples was done and haplotypes were accordingly generated to either include or exclude the linked / unlinked regions. RESULTS: Of the 4 families, family PKDF 1620 showed linkage with DFNB12/CDH23 (D10S1432, D10S606, and D10S1694) and family PKDF 1625 had linkage with DFNB3/MYO15A (D17S2196, D17S2207 and D17S2206). Families PKDF1623 and PKDF1624 showed no linkage with any of the prevalent reported loci in Pakistan . CONCLUSIONS: Linkage to DFNB12 and MYO 15 showed heterogeneity of congenital deafness.


Assuntos
Surdez/genética , Ligação Genética/genética , Adolescente , Adulto , Caderinas/genética , Criança , Pré-Escolar , Consanguinidade , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Miosinas/genética , Paquistão , Linhagem , Adulto Jovem
16.
Nat Cell Biol ; 21(11): 1370-1381, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31685997

RESUMO

Cell migration is hypothesized to involve a cycle of behaviours beginning with leading edge extension. However, recent evidence suggests that the leading edge may be dispensable for migration, raising the question of what actually controls cell directionality. Here, we exploit the embryonic migration of Drosophila macrophages to bridge the different temporal scales of the behaviours controlling motility. This approach reveals that edge fluctuations during random motility are not persistent and are weakly correlated with motion. In contrast, flow of the actin network behind the leading edge is highly persistent. Quantification of actin flow structure during migration reveals a stable organization and asymmetry in the cell-wide flowfield that strongly correlates with cell directionality. This organization is regulated by a gradient of actin network compression and destruction, which is controlled by myosin contraction and cofilin-mediated disassembly. It is this stable actin-flow polarity, which integrates rapid fluctuations of the leading edge, that controls inherent cellular persistence.


Assuntos
Actinas/genética , Movimento Celular/genética , Drosophila melanogaster/embriologia , Mecanotransdução Celular , Peixe-Zebra/embriologia , Actinas/metabolismo , Animais , Polaridade Celular , Rastreamento de Células , Cofilina 1/genética , Cofilina 1/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Embrião não Mamífero , Regulação da Expressão Gênica no Desenvolvimento , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Hemócitos/citologia , Hemócitos/metabolismo , Queratinócitos/citologia , Queratinócitos/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Macrófagos/citologia , Macrófagos/metabolismo , Miosinas/genética , Miosinas/metabolismo , Cultura Primária de Células , Peixe-Zebra/genética , Peixe-Zebra/metabolismo
17.
Mol Cancer ; 18(1): 150, 2019 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-31665067

RESUMO

BACKGROUND: CircMYO10 is a circular RNA generated by back-splicing of gene MYO10 and is upregulated in osteosarcoma cell lines, but its functional role in osteosarcoma is still unknown. This study aimed to clarify the mechanism of circMYO10 in osteosarcoma. METHODS: CircMYO10 expression in 10 paired osteosarcoma and chondroma tissues was assessed by quantitative reverse transcription polymerase chain reaction (PCR). The function of circMYO10/miR-370-3p/RUVBL1 axis was assessed regarding two key characteristics: proliferation and endothelial-mesenchymal transition (EMT). Bioinformatics analysis, western blotting, real-time PCR, fluorescence in situ hybridization, immunoprecipitation, RNA pull-down assays, luciferase reporter assays, chromatin immunoprecipitation, and rescue experiments were used to evaluate the mechanism. Stably transfected MG63 cells were injected via tail vein or subcutaneously into nude mice to assess the role of circMYO10 in vivo. RESULTS: CircMYO10 was significantly upregulated, while miR-370-3p was downregulated, in osteosarcoma cell lines and human osteosarcoma samples. Silencing circMYO10 inhibited cell proliferation and EMT in vivo and in vitro. Mechanistic investigations revealed that miR-370-3p targets RUVBL1 directly, and inhibits the interaction between RUVBL1 and ß-catenin/LEF1 complex while circMYO10 showed a contrary effect via the inhibition of miR-370-3p. RUVBL1 was found to be complexed with chromatin remodeling and histone-modifying factor TIP60, and lymphoid enhancer factor-1 (LEF1) to promote histone H4K16 acetylation (H4K16Ac) in the vicinity of the promoter region of gene C-myc. Chromatin immunoprecipitation methods showed that miR-370-3p sponge promotes H4K16Ac in the indicated region, which is partially abrogated by RUVBL1 small hairpin RNA (shRNA) while circMYO10 showed a contrary result via the inhibition of miR-370-3p. Either miR-370-3p sponge or ShRUVBL1 attenuated circMYO10-induced phenotypes in osteosarcoma cell lines. MiR-370-3p inhibition abrogated the inhibition of proliferation, EMT of osteosarcoma cells in vitro and in vivo seen upon circMYO10 suppression via Wnt/ß-catenin signaling. CONCLUSIONS: CircMYO10 promotes osteosarcoma progression by regulating miR-370-3p/RUVBL1 axis to promote chromatin remodeling and thus enhances the transcriptional activity of ß-catenin/LEF1 complex, which indicates that circMYO10 may be a potential therapeutic target for osteosarcoma treatment.


Assuntos
ATPases Associadas a Diversas Atividades Celulares/genética , Neoplasias Ósseas/genética , Neoplasias Ósseas/metabolismo , Proteínas de Transporte/genética , Montagem e Desmontagem da Cromatina , DNA Helicases/genética , MicroRNAs/genética , Miosinas/genética , Osteossarcoma/genética , Osteossarcoma/metabolismo , RNA Circular , Regiões 3' não Traduzidas , Animais , Neoplasias Ósseas/patologia , Linhagem Celular Tumoral , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Progressão da Doença , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Histonas/metabolismo , Humanos , Fator 1 de Ligação ao Facilitador Linfoide/metabolismo , Metilação , Camundongos , Metástase Neoplásica , Osteossarcoma/patologia , Regiões Promotoras Genéticas , Ligação Proteica , Interferência de RNA , Via de Sinalização Wnt , beta Catenina/metabolismo
18.
PLoS Genet ; 15(10): e1008279, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31603892

RESUMO

Muscle development and lipid accumulation in muscle critically affect meat quality of livestock. However, the genetic factors underlying myofiber-type specification and intramuscular fat (IMF) accumulation remain to be elucidated. Using two independent intercrosses between Western commercial breeds and Korean native pigs (KNPs) and a joint linkage-linkage disequilibrium analysis, we identified a 488.1-kb region on porcine chromosome 12 that affects both reddish meat color (a*) and IMF. In this critical region, only the MYH3 gene, encoding myosin heavy chain 3, was found to be preferentially overexpressed in the skeletal muscle of KNPs. Subsequently, MYH3-transgenic mice demonstrated that this gene controls both myofiber-type specification and adipogenesis in skeletal muscle. We discovered a structural variant in the promotor/regulatory region of MYH3 for which Q allele carriers exhibited significantly higher values of a* and IMF than q allele carriers. Furthermore, chromatin immunoprecipitation and cotransfection assays showed that the structural variant in the 5'-flanking region of MYH3 abrogated the binding of the myogenic regulatory factors (MYF5, MYOD, MYOG, and MRF4). The allele distribution of MYH3 among pig populations worldwide indicated that the MYH3 Q allele is of Asian origin and likely predates domestication. In conclusion, we identified a functional regulatory sequence variant in porcine MYH3 that provides novel insights into the genetic basis of the regulation of myofiber type ratios and associated changes in IMF in pigs. The MYH3 variant can play an important role in improving pork quality in current breeding programs.


Assuntos
Adipogenia/genética , Proteínas do Citoesqueleto/genética , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/crescimento & desenvolvimento , Miosinas/genética , Tecido Adiposo/crescimento & desenvolvimento , Tecido Adiposo/metabolismo , Animais , Cruzamento , Regulação da Expressão Gênica , Estudo de Associação Genômica Ampla , Genótipo , Carne , Camundongos , Camundongos Transgênicos , Músculo Esquelético/metabolismo , Cadeias Pesadas de Miosina/genética , Motivos de Nucleotídeos , Sus scrofa/genética , Sus scrofa/metabolismo , Suínos
19.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 36(10): 965-969, 2019 Oct 10.
Artigo em Chinês | MEDLINE | ID: mdl-31598937

RESUMO

OBJECTIVE: To explore the genetic basis for a family with non-syndromic autosomal recessive deafness. METHODS: The proband and her parents were subjected to physical and audiological examinations. With genomic DNA extracted from peripheral blood samples, next-generation sequencing was carried out using a panel for deafness genes. Suspected mutation was validated by Sanger sequencing and qPCR analysis of her parents. RESULTS: The proband presented bilateral severe sensorineural hearing loss at three days after birth. Her auditory threshold was 110-120 dBnHL but with absence of vestibular and retinal symptoms. Her brother also had deafness but her parents were normal. No abnormality was found upon physical examination of her family members, while audiological examination showed no middle ear or retrocochlear diseases. Next-generation sequencing identified compound heterozygous mutations of the MYO7A gene, including a previously known c.462C>A (p. Cys154Ter) and a novel EX43_46 Del, which were respectively derived from her mother and father. CONCLUSION: The compound heterozygous mutations of the MYO7A gene probably underlie the disease in this family. Our findings has enriched the mutation spectrum for non-syndromic autosomal recessive deafness 2.


Assuntos
Perda Auditiva Neurossensorial/genética , Miosinas/genética , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Mutação , Miosina VIIa , Linhagem
20.
Genes (Basel) ; 10(10)2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31581539

RESUMO

Hereditary hearing impairment (HHI) is a common but heterogeneous clinical entity caused by mutations in a plethora of deafness genes. Research over the past few decades has shown that the genetic epidemiology of HHI varies significantly across populations. In this study, we used different genetic examination strategies to address the genetic causes of HHI in a large Taiwanese cohort composed of >5000 hearing-impaired families. We also analyzed the clinical features associated with specific genetic mutations. Our results demonstrated that next-generation sequencing-based examination strategies could achieve genetic diagnosis in approximately half of the families. Common deafness-associated genes in the Taiwanese patients assessed, in the order of prevalence, included GJB2, SLC26A4, OTOF, MYO15A, and MTRNR1, which were similar to those found in other populations. However, the Taiwanese patients had some unique mutations in these genes. These findings may have important clinical implications for refining molecular diagnostics, facilitating genetic counseling, and enabling precision medicine for the management of HHI.


Assuntos
Conexinas/genética , Perda Auditiva/genética , Miosinas/genética , Grupo com Ancestrais do Continente Asiático/genética , Estudos de Coortes , Conexinas/metabolismo , Surdez/epidemiologia , Surdez/genética , Feminino , Testes Genéticos , Perda Auditiva/diagnóstico , Perda Auditiva/epidemiologia , Perda Auditiva Neurossensorial/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Proteínas de Membrana/genética , Mutação , Miosinas/metabolismo , Transportadores de Sulfato/genética , Taiwan/epidemiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA