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1.
J Pathol ; 263(3): 315-327, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38721910

RESUMO

Hemolysis-induced acute kidney injury (AKI) is attributed to heme-mediated proximal tubule epithelial cell (PTEC) injury and tubular cast formation due to intratubular protein condensation. Megalin is a multiligand endocytic receptor for proteins, peptides, and drugs in PTECs and mediates the uptake of free hemoglobin and the heme-scavenging protein α1-microglobulin. However, understanding of how megalin is involved in the development of hemolysis-induced AKI remains elusive. Here, we investigated the megalin-related pathogenesis of hemolysis-induced AKI and a therapeutic strategy using cilastatin, a megalin blocker. A phenylhydrazine-induced hemolysis model developed in kidney-specific mosaic megalin knockout (MegKO) mice confirmed megalin-dependent PTEC injury revealed by the co-expression of kidney injury molecule-1 (KIM-1). In the hemolysis model in kidney-specific conditional MegKO mice, the uptake of hemoglobin and α1-microglobulin as well as KIM-1 expression in PTECs was suppressed, but tubular cast formation was augmented, likely due to the nonselective inhibition of protein reabsorption in PTECs. Quartz crystal microbalance analysis revealed that cilastatin suppressed the binding of megalin with hemoglobin and α1-microglobulin. Cilastatin also inhibited the specific uptake of fluorescent hemoglobin by megalin-expressing rat yolk sac tumor-derived L2 cells. In a mouse model of hemolysis-induced AKI, repeated cilastatin administration suppressed PTEC injury by inhibiting the uptake of hemoglobin and α1-microglobulin and also prevented cast formation. Hemopexin, another heme-scavenging protein, was also found to be a novel ligand of megalin, and its binding to megalin and uptake by PTECs in the hemolysis model were suppressed by cilastatin. Mass spectrometry-based semiquantitative analysis of urinary proteins in cilastatin-treated C57BL/6J mice indicated that cilastatin suppressed the reabsorption of a limited number of megalin ligands in PTECs, including α1-microglobulin and hemopexin. Collectively, cilastatin-mediated selective megalin blockade is an effective therapeutic strategy to prevent both heme-mediated PTEC injury and cast formation in hemolysis-induced AKI. © 2024 The Pathological Society of Great Britain and Ireland.


Assuntos
Injúria Renal Aguda , Hemólise , Túbulos Renais Proximais , Proteína-2 Relacionada a Receptor de Lipoproteína de Baixa Densidade , Camundongos Knockout , Animais , Proteína-2 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Proteína-2 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Injúria Renal Aguda/metabolismo , Injúria Renal Aguda/patologia , Túbulos Renais Proximais/metabolismo , Túbulos Renais Proximais/patologia , Túbulos Renais Proximais/efeitos dos fármacos , Hemoglobinas/metabolismo , Camundongos , Cilastatina/farmacologia , Modelos Animais de Doenças , Fenil-Hidrazinas , Camundongos Endogâmicos C57BL , Masculino , Receptor Celular 1 do Vírus da Hepatite A/metabolismo , alfa-Globulinas/metabolismo , Humanos
2.
J Immunol ; 210(3): 335-347, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36525065

RESUMO

Melanoma differentiation-associated gene 5 (MDA5), a member of the retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs), has pivotal roles in innate immune responses against many positive-stranded RNA viruses, including picornavirus and coronavirus. Upon engagement with dsRNA derived from viral infection, MDA5 initiates coordinated signal transduction leading to type I IFN induction to restrict viral replication. In this study, we describe a targeted cleavage events of MDA5 by the 3C protease from Theilovirus. Upon ectopic expression of theilovirus 3C protease from Saffold virus or Theiler's murine encephalomyelitis virus but not encephalomyocarditis virus, fragments of cleaved MDA5 were observed in a dose-dependent manner. When enzymatically inactive Theilovirus 3C protease was expressed, MDA5 cleavage was completely abrogated. Mass spectrometric analysis identified two cleavage sites at the C terminus of MDA5, cleaving off one of the RNA-binding domains. The same cleavage pattern was observed during Theilovirus infection. The cleavage of MDA5 by Theilovirus protease impaired ATP hydrolysis, RNA binding, and filament assembly on RNA, resulting in dysfunction of MDA5 as an innate immune RNA sensor for IFN induction. Furthermore, the cleavage-resistant MDA5 mutant against the 3C protease showed an enhanced IFN response during Saffold virus infection, indicating that Theilovirus has a strategy to circumvent the antiviral immune response by cleaving MDA5 using 3C protease. In summary, these data suggest MDA5 cleavage by 3C protease as a novel immune evasive strategy of Theilovirus.


Assuntos
Helicase IFIH1 Induzida por Interferon , RNA de Cadeia Dupla , Theilovirus , Animais , Camundongos , Cisteína Endopeptidases/genética , Interações Hospedeiro-Patógeno , Imunidade Inata , Interferon Tipo I/metabolismo , Helicase IFIH1 Induzida por Interferon/genética , Helicase IFIH1 Induzida por Interferon/metabolismo , Peptídeo Hidrolases/metabolismo , RNA de Cadeia Dupla/imunologia , RNA de Cadeia Dupla/metabolismo , Proteases Virais 3C
3.
J Neurosci ; 43(32): 5753-5768, 2023 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-37344234

RESUMO

Axon fasciculation is thought to be a critical step in neural circuit formation and function. Recent studies have revealed various molecular mechanisms that underlie axon fasciculation; however, the impacts of axon fasciculation, and its corollary, defasciculation, on neural circuit wiring remain unclear. Corticospinal (CS) neurons in the sensorimotor cortex project axons to the spinal cord to control skilled movements. In rodents, the axons remain tightly fasciculated in the brain and traverse the dorsal funiculus of the spinal cord. Here we show that plexinA1 (PlexA1) and plexinA3 (PlexA3) receptors are expressed by CS neurons, whereas their ligands, semaphorin-5A (Sema5A) and semaphorin-5B (Sema5B) are expressed in the medulla at the decussation site of CS axons to inhibit premature defasciculation of these axons. In the absence of Sema5A/5B-PlexA1/A3 signaling, some CS axons are prematurely defasciculated in the medulla of the brainstem, and those defasciculated CS axons aberrantly transverse in the spinal gray matter instead of the spinal dorsal funiculus. In the absence of Sema5A/Sema5B-PlexA1/A3 signaling, CS axons, which would normally innervate the lumbar spinal cord, are unbundled in the spinal gray matter, and prematurely innervate the cervical gray matter with reduced innervation of the lumbar gray matter. In both Sema5A/5B and PlexA1/A3 mutant mice (both sexes), stimulation of the hindlimb motor cortex aberrantly evokes robust forelimb muscle activation. Finally, Sema5A/5B and PlexA1/A3 mutant mice show deficits in skilled movements. These results suggest that proper fasciculation of CS axons is required for appropriate neural circuit wiring and ultimately affect the ability to perform skilled movements.SIGNIFICANCE STATEMENT Axon fasciculation is believed to be essential for neural circuit formation and function. However, whether and how defects in axon fasciculation affect the formation and function of neural circuits remain unclear. Here we examine whether the transmembrane proteins semaphorin-5A (Sema5A) and semaphorin-5B (Sema5B), and their receptors, plexinA1 (PlexA1) and plexinA3 (PlexA3) play roles in the development of corticospinal circuits. We find that Sema5A/Sema5B and PlexA1/A3 are required for proper axon fasciculation of corticospinal neurons. Furthermore, Sema5A/5B and PlexA1/A3 mutant mice show marked deficits in skilled motor behaviors. Therefore, these results strongly suggest that proper corticospinal axon fasciculation is required for the appropriate formation and functioning of corticospinal circuits in mice.


Assuntos
Semaforinas , Feminino , Masculino , Camundongos , Animais , Semaforinas/metabolismo , Fasciculação Axônica , Neurônios/metabolismo , Axônios/fisiologia , Medula Espinal/metabolismo
4.
Development ; 148(12)2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34128984

RESUMO

The specificity of monosynaptic connections between proprioceptive sensory neurons and their recipient spinal motor neurons depends on multiple factors, including motor neuron positioning and dendrite morphology, axon projection patterns of proprioceptive sensory neurons in the spinal cord, and the ligand-receptor molecules involved in cell-to-cell recognition. However, with few exceptions, the transcription factors engaged in this process are poorly characterized. Here, we show that members of the HoxD family of transcription factors play a crucial role in the specificity of monosynaptic sensory-motor connections. Mice lacking Hoxd9, Hoxd10 and Hoxd11 exhibit defects in locomotion but have no obvious defects in motor neuron positioning or dendrite morphology through the medio-lateral and rostro-caudal axes. However, we found that quadriceps motor neurons in these mice show aberrant axon development and receive inappropriate inputs from proprioceptive sensory axons innervating the obturator muscle. These genetic studies demonstrate that the HoxD transcription factors play an integral role in the synaptic specificity of monosynaptic sensory-motor connections in the developing spinal cord.


Assuntos
Proteínas de Ligação a DNA/genética , Células Receptoras Sensoriais/metabolismo , Medula Espinal/metabolismo , Fatores de Transcrição/genética , Animais , Axônios/metabolismo , Diferenciação Celular/genética , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica , Camundongos , Modelos Biológicos , Neurônios Motores/citologia , Neurônios Motores/metabolismo , Especificidade de Órgãos , Isoformas de Proteínas , Células Receptoras Sensoriais/citologia , Fatores de Transcrição/metabolismo
5.
Microbiol Immunol ; 68(4): 130-147, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38294180

RESUMO

Vaccination is an important factor in public health. The recombinant bacillus Calmette Guérin (rBCG) vaccine, which expresses foreign antigens, is expected to be a superior vaccine against infectious diseases. Here, we report a new recombination platform in which the BCG Tokyo strain is transformed with nucleotide sequences encoding foreign protein fused with the MPB70 immunogenic protein precursor. By RNA-sequencing, mpb70 was found to be the most transcribed among all known genes of BCG Tokyo. Small oligopeptide, namely, polyhistidine tag, was able to be expressed in and secreted from rBCG through a process in which polyhistidine tag fused with intact MPB70 were transcribed by an mpb70 promoter. This methodology was applied to develop an rBCG expressing the receptor binding domain (RBD) of severe acute respiratory syndrome coronavirus 2. Immunoblotting images and mass spectrometry data showed that RBD was also secreted from rBCG. Sera from mice vaccinated with the rBCG showed a tendency of weak neutralizing capacity. The secretion was retained even after a freeze-drying process. The freeze-dried rBCG was administered to and recovered from mice. Recovered rBCG kept secreting RBD. Collectively, our recombination platform offers stable secretion of foreign antigens and can be applied to the development of practical rBCGs.


Assuntos
Vacina BCG , Mycobacterium bovis , Animais , Camundongos , Vacina BCG/genética , Tóquio , Mycobacterium bovis/genética , Ativação Linfocitária , Engenharia Genética , Vacinas Sintéticas
6.
Biochem Biophys Res Commun ; 681: 111-119, 2023 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-37774568

RESUMO

The basic, intrinsically disordered regions of eukaryotic histones and their bacterial counterparts are presumed to act as signaling hubs to regulate the compaction of chromosomes or nucleoids and various DNA processes such as gene expression, recombination, and DNA replication. Posttranslational modifications (PTMs) on these regions are pivotal in regulating chromosomal or nucleoid compaction and DNA processes. However, the low sequence complexity and the presence of short lysine-rich repeats in the regions have hindered the accurate determination of types and locations of PTMs using conventional proteomic procedures. We described a limited proteolysis protocol using trypsin to analyze PTMs on mycobacterial DNA-binding protein 1 (MDP1), a nucleoid-associated protein in mycobacterial species that possesses an extended, lysine-rich, intrinsically disordered region in its C-terminal domain. This limited proteolysis approach successfully revealed significant methylation on many lysine residues in the C-terminal domain of MDP1 purified from Mycobacterium tuberculosis, which was lacking in the corresponding region of recombinant MDP1 expressed in Escherichia coli.

7.
Genes Dev ; 29(24): 2617-32, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26680304

RESUMO

Commissural axon guidance depends on a myriad of cues expressed by intermediate targets. Secreted semaphorins signal through neuropilin-2/plexin-A1 receptor complexes on post-crossing commissural axons to mediate floor plate repulsion in the mouse spinal cord. Here, we show that neuropilin-2/plexin-A1 are also coexpressed on commissural axons prior to midline crossing and can mediate precrossing semaphorin-induced repulsion in vitro. How premature semaphorin-induced repulsion of precrossing axons is suppressed in vivo is not known. We discovered that a novel source of floor plate-derived, but not axon-derived, neuropilin-2 is required for precrossing axon pathfinding. Floor plate-specific deletion of neuropilin-2 significantly reduces the presence of precrossing axons in the ventral spinal cord, which can be rescued by inhibiting plexin-A1 signaling in vivo. Our results show that floor plate-derived neuropilin-2 is developmentally regulated, functioning as a molecular sink to sequester semaphorins, preventing premature repulsion of precrossing axons prior to subsequent down-regulation, and allowing for semaphorin-mediated repulsion of post-crossing axons.


Assuntos
Axônios/fisiologia , Interneurônios Comissurais/fisiologia , Neuropilina-2/metabolismo , Semaforinas/metabolismo , Animais , Células Cultivadas , Interneurônios Comissurais/citologia , Embrião de Mamíferos , Deleção de Genes , Regulação da Expressão Gênica no Desenvolvimento , Camundongos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Neuropilina-2/genética , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Transdução de Sinais
8.
J Neurosci ; 41(50): 10247-10260, 2021 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-34759029

RESUMO

Axon regeneration after spinal cord injury (SCI) is limited by both a decreased intrinsic ability of neurons to grow axons and the growth-hindering effects of extrinsic inhibitory molecules expressed around the lesion. Deletion of phosphatase and tensin homolog (Pten) augments mechanistic target of rapamycin (mTOR) signaling and enhances the intrinsic regenerative response of injured corticospinal neurons after SCI. Because of the variety of growth-restrictive extrinsic molecules, it remains unclear how inhibition of conserved inhibitory signaling elements would affect axon regeneration and rewiring after SCI. Moreover, it remains unknown how a combinatorial approach to modulate both extrinsic and intrinsic mechanisms can enhance regeneration and rewiring after SCI. In the present study, we deleted RhoA and RhoC, which encode small GTPases that mediate growth inhibition signals of a variety of extrinsic molecules, to remove global extrinsic pathways. RhoA/RhoC double deletion in mice suppressed retraction or dieback of corticospinal axons after SCI. In contrast, Pten deletion increased regrowth of corticospinal axons into the lesion core. Although deletion of both RhoA and Pten did not promote axon regrowth across the lesion or motor recovery, it additively promoted rewiring of corticospinal circuits connecting the cerebral cortex, spinal cord, and hindlimb muscles. Our genetic findings, therefore, reveal that a combinatorial approach to modulate both intrinsic and extrinsic factors can additively promote neural circuit rewiring after SCI.SIGNIFICANCE STATEMENT SCI often causes severe motor deficits because of damage to the corticospinal tract (CST), the major neural pathway for voluntary movements. Regeneration of CST axons is required to reconstruct motor circuits and restore functions; however, a lower intrinsic ability to grow axons and extrinsic inhibitory molecules severely limit axon regeneration in the CNS. Here, we investigated whether suppression of extrinsic inhibitory cues by genetic deletion of Rho as well as enhancement of the intrinsic pathway by deletion of Pten could enable axon regrowth and rewiring of the CST after SCI. We show that simultaneous elimination of extrinsic and intrinsic signaling pathways can additively promote axon sprouting and rewiring of the corticospinal circuits. Our data demonstrate a potential molecular approach to reconstruct motor pathways after SCI.


Assuntos
Regeneração Nervosa/fisiologia , PTEN Fosfo-Hidrolase/metabolismo , Tratos Piramidais/fisiopatologia , Traumatismos da Medula Espinal/fisiopatologia , Proteínas rho de Ligação ao GTP/metabolismo , Animais , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
9.
EMBO J ; 37(4)2018 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-29348324

RESUMO

Newborn neurons maintain a very simple, bipolar shape, while they migrate from their birthplace toward their destinations in the brain, where they differentiate into mature neurons with complex dendritic morphologies. Here, we report a mechanism by which the termination of neuronal migration is maintained in the postnatal olfactory bulb (OB). During neuronal deceleration in the OB, newborn neurons transiently extend a protrusion from the proximal part of their leading process in the resting phase, which we refer to as a filopodium-like lateral protrusion (FLP). The FLP formation is induced by PlexinD1 downregulation and local Rac1 activation, which coincide with microtubule reorganization and the pausing of somal translocation. The somal translocation of resting neurons is suppressed by microtubule polymerization within the FLP The timing of neuronal migration termination, controlled by Sema3E-PlexinD1-Rac1 signaling, influences the final positioning, dendritic patterns, and functions of the neurons in the OB These results suggest that PlexinD1 signaling controls FLP formation and the termination of neuronal migration through a precise control of microtubule dynamics.


Assuntos
Movimento Celular , Extensões da Superfície Celular/fisiologia , Glicoproteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurogênese , Neurônios/citologia , Neurônios/fisiologia , Animais , Animais Recém-Nascidos , Células Cultivadas , Proteínas do Citoesqueleto , Glicoproteínas/genética , Glicoproteínas/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular , Glicoproteínas de Membrana/genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Proteínas do Tecido Nervoso/genética , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Semaforinas , Transdução de Sinais , Proteínas rac1 de Ligação ao GTP/genética , Proteínas rac1 de Ligação ao GTP/metabolismo
10.
Nat Immunol ; 11(7): 594-600, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20512151

RESUMO

The recirculation of leukocytes is essential for proper immune responses. However, the molecular mechanisms that regulate the entry of leukocytes into the lymphatics remain unclear. Here we show that plexin-A1, a principal receptor component for class III and class VI semaphorins, was crucially involved in the entry of dendritic cells (DCs) into the lymphatics. Additionally, we show that the semaphorin Sema3A, but not Sema6C or Sema6D, was required for DC transmigration and that Sema3A produced by the lymphatics promoted actomyosin contraction at the trailing edge of migrating DCs. Our findings not only demonstrate that semaphorin signals are involved in DC trafficking but also identify a previously unknown mechanism that induces actomyosin contraction as these cells pass through narrow gaps.


Assuntos
Células Dendríticas/metabolismo , Vasos Linfáticos/metabolismo , Miosina Tipo II/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Receptores de Superfície Celular/metabolismo , Semaforinas/metabolismo , Actomiosina/metabolismo , Transferência Adotiva , Animais , Ensaios de Migração de Leucócitos , Movimento Celular/imunologia , Células Cultivadas , Células Dendríticas/imunologia , Células Dendríticas/patologia , Técnicas de Introdução de Genes , Imunidade , Vasos Linfáticos/patologia , Camundongos , Camundongos Knockout , Contração Muscular , Miosina Tipo II/imunologia , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/imunologia , Neuropilina-1/genética , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/imunologia , Semaforinas/genética , Semaforinas/imunologia , Transdução de Sinais
11.
Transpl Int ; 35: 10248, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35401036

RESUMO

Isohemagglutinin assays employing red blood cells (RBCs) are the most common assays used to measure antibody titer in ABO-incompatible kidney transplantation (ABOi KTx). However, ABO antigens expressed on RBCs are not identical to those of kidney and antibody titers do not always correlate with clinical outcome. We previously reported that CD31 was the main protein linked to ABO antigens on kidney endothelial cells (KECs), which was different from those on RBCs. We developed a new method to measure antibody titer using a microarray of recombinant CD31 (rCD31) linked to ABO antigens (CD31-ABO microarray). Mass spectrometry analysis suggested that rCD31 and native CD31 purified from human kidney had similar ABO glycan. To confirm clinical use of CD31-ABO microarray, a total of 252 plasma samples including volunteers, hemodialysis patients, and transplant recipients were examined. In transplant recipients, any initial IgG or IgM antibody intensity >30,000 against the donor blood type in the CD31-ABO microarray showed higher sensitivity, specificity, positive predictive value, and negative predictive value of AABMR, compared to isohemagglutinin assays. Use of a CD31-ABO microarray to determine antibody titer specifically against ABO antigens expressed on KECs will contribute to precisely predicting AABMR or preventing over immunosuppression following ABOi KTx.


Assuntos
Transplante de Rim , Sistema ABO de Grupos Sanguíneos , Anticorpos , Incompatibilidade de Grupos Sanguíneos , Carboidratos , Células Endoteliais , Rejeição de Enxerto , Humanos , Transplante de Rim/métodos , Molécula-1 de Adesão Celular Endotelial a Plaquetas
12.
J Neurosci ; 40(28): 5402-5412, 2020 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-32471877

RESUMO

Axon guidance molecules and neuronal activity have been implicated in the establishment and refinement of neural circuits during development. It is unclear, however, whether these guidance molecule- and activity-dependent mechanisms interact with one another to shape neural circuit formation. The formation of corticospinal (CS) circuits, which are essential for voluntary movements, involves both guidance molecule- and activity-dependent components during development. We previously showed that semaphorin6D (Sema6D)-plexinA1 (PlexA1) signaling eliminates ipsilateral projections of CS neurons in the spinal cord, while other studies demonstrate that CS projections to the spinal cord are eliminated in an activity-dependent manner. Here we show that inhibition of cortical neurons during postnatal development causes defects in elimination of ipsilateral CS projections in mice. We further show that mice that lack the activity-dependent Bax/Bak pathway or caspase-9 similarly exhibit defects in elimination of ipsilateral CS projections, suggesting that the activity-dependent Bax/Bak-caspase-9 pathway is essential for the removal of ipsilateral CS projections. Interestingly, either inhibition of neuronal activity in the cortex or deletion of Bax/Bak in mice causes a reduction in PlexA1 protein expression in corticospinal neurons. Finally, intracortical microstimulation induces activation of only contralateral forelimb muscles in control mice, whereas it induces activation of both contralateral and ipsilateral muscles in mice with cortical inhibition, suggesting that the ipsilaterally projecting CS axons that have been maintained in mice with cortical inhibition form functional connections. Together, these results provide evidence of a potential link between the repellent signaling of Sema6D-PlexA1 and neuronal activity to regulate axon elimination.SIGNIFICANCE STATEMENT Both axon guidance molecules and neuronal activity regulate axon elimination to refine neuronal circuits during development. However, the degree to which these mechanisms operate independently or cooperatively to guide network generation is unclear. Here, we show that neuronal activity-driven Bax/Bak-caspase signaling induces expression of the PlexA1 receptor for the repellent Sema6D molecule in corticospinal neurons (CSNs). This cascade eliminates ipsilateral projections of CSNs in the spinal cord during early postnatal development. The absence of PlexA1, neuronal activity, Bax and Bak, or caspase-9 leads to the maintenance of ipsilateral projections of CSNs, which can form functional connections with spinal neurons. Together, these studies reveal how the Sema6D-PlexA1 signaling and neuronal activity may play a cooperative role in refining CS axonal projections.


Assuntos
Axônios/metabolismo , Caspases/metabolismo , Tratos Piramidais/crescimento & desenvolvimento , Semaforinas/metabolismo , Transdução de Sinais/fisiologia , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo , Proteína X Associada a bcl-2/metabolismo , Animais , Orientação de Axônios/fisiologia , Camundongos , Vias Neurais/crescimento & desenvolvimento , Vias Neurais/metabolismo , Neurônios/fisiologia , Tratos Piramidais/metabolismo
13.
Biochem Biophys Res Commun ; 557: 294-301, 2021 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-33894417

RESUMO

Pontin and Reptin are closely related proteins belonging to the AAA+ (ATPases Associated with various cellular Activities) family. They form a hetero-oligomeric complex, Pontin/Reptin, which is involved in protein stability and assembly of the protein complexes as a molecular chaperone. Overexpression of Pontin and Reptin in tumor cells has been reported and is implicated in the development of various cancers. However, the molecular mechanism of Pontin/Reptin function in oral squamous cell carcinoma (OSCC) development remains unclear. Here, we identify HEAT repeat-containing protein 1 (HEATR1) as a novel binding factor of Pontin/Reptin. Functionally, HEATR1 stabilizes Pontin/Reptin and positively regulates OSCC cell proliferation by activating mTOR and pre-rRNA synthesis. We also find that HEATR1 expression is markedly upregulated in tumor region of OSCC tissue. Hence, we propose that HEATR1 is involved in the regulation of mTOR and ribosome biogenesis as a potential protein stabilizer of Pontin/Reptin in OSCC.


Assuntos
ATPases Associadas a Diversas Atividades Celulares/metabolismo , Proteínas de Transporte/metabolismo , Proliferação de Células/genética , DNA Helicases/metabolismo , Antígenos de Histocompatibilidade Menor/metabolismo , Neoplasias Bucais/metabolismo , Proteínas de Ligação a RNA/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/metabolismo , ATPases Associadas a Diversas Atividades Celulares/genética , Proteínas de Transporte/genética , Linhagem Celular Tumoral , DNA Helicases/genética , Regulação Neoplásica da Expressão Gênica/genética , Genes de RNAr , Humanos , Imuno-Histoquímica , Antígenos de Histocompatibilidade Menor/genética , Neoplasias Bucais/genética , Ligação Proteica , Interferência de RNA , Proteínas de Ligação a RNA/genética , Reação em Cadeia da Polimerase em Tempo Real , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Serina-Treonina Quinases TOR/metabolismo , Espectrometria de Massas em Tandem , Regulação para Cima
14.
Cell Tissue Res ; 386(1): 117-126, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34309730

RESUMO

Fibroblast growth factor 2 (FGF2) augments podocyte injury, which induces glomerulosclerosis, although the mechanisms remain obscure. In this study, we investigated the effects of FGF2 on cultured podocytes with interdigitating cell processes in rats. After 48 h incubation with FGF2 dynamic changes in the shape of primary processes and cell bodies of podocytes resulted in the loss of interdigitation, which was clearly shown by time-lapse photography. FGF2 reduced the gene expressions of constituents of the slit diaphragm, inflections of intercellular junctions positive for nephrin, and the width of the intercellular space. Immunostaining for the proliferation marker Ki-67 was rarely seen and weakly stained in the control without FGF2, whereas intensely stained cells were frequently found in the presence of FGF2. Binucleation and cell division were also observed, although no significant increase in cell number was shown. An in vitro scratch assay revealed that FGF2 enhanced migration of podocytes. These findings show that FGF2 makes podocytes to transition from the quiescent state into the cell cycle and change their morphology due to enhanced motility, and that the culture system in this study is useful for analyzing the pathological changes of podocytes in vivo.


Assuntos
Fator 2 de Crescimento de Fibroblastos/metabolismo , Podócitos/metabolismo , Animais , Células Cultivadas , Masculino , Ratos , Ratos Sprague-Dawley
15.
Cereb Cortex ; 30(11): 5702-5716, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32564090

RESUMO

Axon regeneration is limited in the central nervous system, which hinders the reconstruction of functional circuits following spinal cord injury (SCI). Although various extrinsic molecules to repel axons following SCI have been identified, the role of semaphorins, a major class of axon guidance molecules, has not been thoroughly explored. Here we show that expression of semaphorins, including Sema5a and Sema6d, is elevated after SCI, and genetic deletion of either molecule or their receptors (neuropilin1 and plexinA1, respectively) suppresses axon retraction or dieback in injured corticospinal neurons. We further show that Olig2+ cells are essential for SCI-induced semaphorin expression, and that Olig2 binds to putative enhancer regions of the semaphorin genes. Finally, conditional deletion of Olig2 in the spinal cord reduces the expression of semaphorins, alleviating the axon retraction. These results demonstrate that semaphorins function as axon repellents following SCI, and reveal a novel transcriptional mechanism for controlling semaphorin levels around injured neurons to create zones hostile to axon regrowth.


Assuntos
Regulação da Expressão Gênica/fisiologia , Regeneração Nervosa/fisiologia , Fator de Transcrição 2 de Oligodendrócitos/metabolismo , Semaforinas/biossíntese , Traumatismos da Medula Espinal/metabolismo , Animais , Axônios/patologia , Camundongos , Camundongos Endogâmicos C57BL , Tratos Piramidais/lesões , Tratos Piramidais/metabolismo , Traumatismos da Medula Espinal/patologia
16.
BMC Health Serv Res ; 21(1): 1333, 2021 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-34903246

RESUMO

BACKGROUND: In Japan, non-pharmacists who are accredited as registered salespersons can sell over-the-counter (OTC) drugs, and they play a very important role in supporting proper OTC drug use by consumers. The purpose of this study was to evaluate information provided to and information collected from consumers, and cooperation with pharmacists during OTC drug sales by registered salespersons, and to clarify their related concerns and behaviors. METHODS: A cross-sectional questionnaire-based survey of 385 registered salespersons working at 56 drugstores throughout Japan was conducted. Based on the questionnaire survey, the frequency of information provision/collection in various categories was determined for the registered salespersons. The relation between concerns of registered salespersons relating to OTC drug sales and the frequency of information provision/collection was examined. The frequency of consultation of registered salespersons with a pharmacist was calculated for registered salespersons with/without in-store pharmacists. The χ-square test or Fisher's exact test was performed to assess the significance of differences. RESULTS: Two hundred and seven registered salespersons (53.7%) responded completely. A greater number of OTC drug purchasers per day was associated with a greater frequency of information provision about "side effects" and information collection about "favorite items" (alcohol, tobacco, health foods, etc.) (p < 0.05). One hundred and thirty-nine (67.2%) participants had concerns about "interactions between OTC drugs and prescription drugs", and these concerns were related to the frequency of information provision/collection (p < 0.05). Regarding the frequency of consultation with a pharmacist, 35 of 46 participants (76.1%) working with pharmacists answered "always" or "usually", whereas only 19 of 161 participants (11.8%) working without full-time pharmacists answered "always" or "usually". More than half of the registered salespersons thought that cooperation with a pharmacist was necessary when they were "asked about concomitant use with prescription drugs" or "told that side effects happened." CONCLUSIONS: The results of this study show that experienced registered salespersons selling OTC drugs are more likely to collect information from consumers and to provide information to consumers. It appears to be important for registered salespersons to cooperate with pharmacists in order to provide and collect appropriate information about concomitant medications.


Assuntos
Medicamentos sem Prescrição , Farmácias , Estudos Transversais , Humanos , Farmacêuticos , Inquéritos e Questionários
17.
Sensors (Basel) ; 21(18)2021 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-34577463

RESUMO

In this paper, we will introduce a method for observing microvascular waves (MVW) by extracting different images from the available images in the video taken with consumer cameras. Microvascular vasomotion is a dynamic phenomenon that can fluctuate over time for a variety of reasons and its sensing is used for variety of purposes. The special device, a side stream dark field camera (SDF camera) was developed in 2015 for the medical purpose to observe blood flow from above the epidermis. However, without using SDF cameras, smart signal processing can be combined with a consumer camera to analyze the global motion of microvascular vasomotion. MVW is a propagation pattern of microvascular vasomotions which reflects biological properties of vascular network. In addition, even without SDF cameras, MVW can be analyzed as a spatial and temporal pattern of microvascular vasomotion using a combination of advanced signal processing with consumer cameras. In this paper, we will demonstrate that such vascular movements and MVW can be observed using a consumer cameras. We also show a classification using it.


Assuntos
Hemodinâmica , Movimento
18.
J Neurosci ; 39(45): 8885-8899, 2019 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-31537704

RESUMO

Corticospinal (CS) neurons in layer V of the sensorimotor cortex are essential for voluntary motor control. Those neurons project axons to specific segments along the rostro-caudal axis of the spinal cord, and reach their spinal targets by sending collateral branches interstitially along axon bundles. Currently, little is known how CS axon collaterals are formed in the proper spinal cord regions. Here, we show that the semaphorin3A (Sema3A)-neuropilin-1 (Npn-1) signaling pathway is an essential negative regulator of CS axon collateral formation in the spinal cord from mice of either sex. Sema3A is expressed in the ventral spinal cord, whereas CS neurons express Npn-1, suggesting that Sema3A might prevent CS axons from entering the ventral spinal cord. Indeed, the ectopic expression of Sema3A in the spinal cord in vivo inhibits CS axon collateral formation, whereas Sema3A or Npn-1 mutant mice have ectopic CS axon collateral formation within the ventral spinal cord compared with littermate controls. Finally, Npn-1 mutant mice exhibit impaired skilled movements, likely because of aberrantly formed CS connections in the ventral spinal cord. These genetic findings reveal that Sema3A-Npn-1 signaling-mediated inhibition of CS axon collateral formation is critical for proper CS circuit formation and the ability to perform skilled motor behaviors.SIGNIFICANCE STATEMENT CS neurons project axons to the spinal cord to control skilled movements in mammals. Previous studies revealed some of the molecular mechanisms underlying different phases of CS circuit development such as initial axon guidance in the brain, and midline crossing in the brainstem and spinal cord. However, the molecular mechanisms underlying CS axon collateral formation in the spinal gray matter has remained obscure. In this study, using in vivo gain-of- and loss-of-function experiments, we show that Sema3A-Npn-1 signaling functions to inhibit CS axon collateral formation in the ventral spinal cord, allowing for the development of proper skilled movements in mice.


Assuntos
Orientação de Axônios , Movimento , Tratos Piramidais/metabolismo , Semaforina-3A/metabolismo , Animais , Feminino , Aprendizagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neuropilina-1/genética , Neuropilina-1/metabolismo , Tratos Piramidais/crescimento & desenvolvimento , Tratos Piramidais/fisiologia , Semaforina-3A/genética , Transdução de Sinais
19.
Cell Tissue Res ; 380(3): 581-591, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31989254

RESUMO

Phenotypic changes in culture hamper the identification and characterization of cultured podocytes and parietal epithelial cells of the Bowman's capsule (PECs). We have recently established culture conditions that restore podocytes to their differentiated phenotypes. We compared podocytes and PECs cultured under the same conditions to determine the unique characteristics of the two cell types. Performing this comparison under the same conditions accentuated these differences. Podocytes behaved like non-epithelial cells by extending cell processes even at confluence. By contrast, PECs behaved like typical epithelial cells by maintaining a polygonal appearance. Other differences were identified using immunostaining and RT-PCR; podocytes expressed high levels of podocyte-specific markers while PECs expressed high levels of PEC-specific markers. However, while podocytes expressed low levels of PEC markers, PECs expressed low levels of podocyte markers. Therefore, the identification of podocytes and PECs in culture requires the evaluation of respective cell markers and the expression of markers for other cell types.


Assuntos
Cápsula Glomerular/citologia , Células Epiteliais/citologia , Podócitos/citologia , Animais , Biomarcadores/metabolismo , Células Cultivadas , Ratos
20.
Blood Purif ; 49(5): 614-621, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31968345

RESUMO

INTRODUCTION: Among patients regularly undergoing hemodialysis, hypocarnitinaemia often develops as a consequence of inadequate dietary intake, reduced synthesis in the body, and considerable losses during hemodialysis. OBJECTIVES: To evaluate the effects of L-carnitine supplementation on patients with end-stage kidney disease (ESKD) who underwent hemodialysis. METHODS: Thirty-one patients with ESKD, comprising 18 men and 13 women, with a median age of 72 (range 58-89) years, who underwent regular hemodialysis received treatment with L-carnitine for 1 year. The total and free carnitine, acylcarnitine, and amino acids (AA) levels before and after L-carnitine treatment were analyzed, and the blood biochemistry results and clinical profiles of the subjects were compared before and after treatment. RESULTS: The median (interquartile range [IQR]) serum total and free carnitine and acylcarnitine levels significantly increased from 34.5 (28.2-44.3), 20.9 (15.8-27.6), and 14.1 (11.2-17.6) µmol/L, respectively to 407.4 (371.6-493.5), 270.2 (228.3-316.0), and 155.0 (136.1-168.5) µmol/L, respectively, after treatment (all p < 0.001). The median (IQR) blood valine, tyrosine, phenylalanine, and citrulline levels increased from 0.94 (0.80-1.09), 0.45 (0.39-0.55), 0.61 (0.56-0.79), and 1.04 (0.79-1.26) mg/dL, respectively to 1.24 (1.13-1.54), 0.76 (0.62-0.85), 0.90 (0.70-1.04), and 1.22 (0.92-1.39) mg/dL, respectively, following L-carnitine treatment (p < 0.001, p < 0.001, p = 0.002, and p = 0.030, respectively); however, the median (IQR) blood arginine level decreased from 0.20 (0.13-0.24) to 0.09 (0.06-0.14) mg/dL after treatment (p < 0.001). The median (IQR) percentage fractional shortening (41.5 vs. 41.9%; p = 0.012) and left ventricular ejection fraction (65.2 vs. 67.3%; p = 0.036) increased significantly following treatment. CONCLUSIONS: L-Carnitine increased the blood acylcarnitine levels, enhanced fatty acid metabolism, and affected AAs metabolism; this may be beneficial for energy production within the cardiac and skeletal muscles.


Assuntos
Aminoácidos/sangue , Carnitina , Falência Renal Crônica , Diálise Renal , Idoso , Idoso de 80 Anos ou mais , Carnitina/administração & dosagem , Carnitina/farmacocinética , Feminino , Humanos , Falência Renal Crônica/sangue , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade
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