Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 44
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Biomacromolecules ; 25(7): 4001-4013, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38814168

RESUMO

A major component of the extracellular matrix (ECM), laminins, modulates cells via diverse receptors. Their fragments have emerging utility as components of "ECM-mimetics" optimized to promote cell-based therapies. Recently, we reported that a bioactive laminin peptide known as A99 enhanced cell binding and spreading via fusion to an elastin-like polypeptide (ELP). The ELP "handle" serves as a rapid, noncovalent strategy to concentrate bioactive peptide mixtures onto a surface. We now report that this strategy can be further generalized across an expanded panel of additional laminin-derived elastin-like polypeptides (LELPs). A99 (AGTFALRGDNPQG), A2G80 (VQLRNGFPYFSY), AG73 (RKRLQVQLSIRT), and EF1m (LQLQEGRLHFMFD) all promote cell spreading while showing morphologically distinct F-actin formation. Equimolar mixtures of A99:A2G80-LELPs have synergistic effects on adhesion and spreading. Finally, three of these ECM-mimetics promote the neurite outgrowth of PC-12 cells. The evidence presented here demonstrates the potential of ELPs to deposit ECM-mimetics with applications in regenerative medicine, cell therapy, and tissue engineering.


Assuntos
Adesão Celular , Elastina , Laminina , Laminina/química , Laminina/farmacologia , Elastina/química , Animais , Ratos , Células PC12 , Adesão Celular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Matriz Extracelular/química , Peptídeos/química , Peptídeos/farmacologia , Polipeptídeos Semelhantes à Elastina
2.
Invest Ophthalmol Vis Sci ; 64(4): 1, 2023 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-37010857

RESUMO

Purpose: To analyze the changes in the lacrimal gland (LG) miRNAome from male nonobese diabetic (NOD) mice with autoimmune dacryoadenitis compared with LG from healthy male BALB/c and dacryoadenitis-free female NOD mice. Methods: LG from these mice were collected for small RNA sequencing to identify dysregulated miRNAs; hits were validated by RT-qPCR in male NOD and BALB/c LG. Dysregulation of validated species within immune cell-enriched cell fractions and epithelial-enriched cell fractions from LG was probed by RT-qPCR. Ingenuity pathway analysis identified putative miRNA targets, which were examined in publicly available mRNA-seq datasets. Western blotting and confocal imaging of immunofluorescence enabled validation of some molecular changes at the protein level. Results: Male NOD LG exhibited 15 and 13 significantly up- and downregulated miRNAs, respectively. Dysregulated expression of 14 of these miRNAs (9 upregulated, 5 downregulated) was validated in male NOD versus BALB/c LG by RT-qPCR. Seven of the upregulated miRNAs were increased owing to their abundance in immune cell-enriched cell fractions, whereas four downregulated miRNAs were largely expressed in epithelial-enriched cell fractions. Ingenuity pathway analysis predicted the upregulation of IL-6 and IL-6-like pathways as an outcome of miRNA dysregulation. Increased expression of several genes in these pathways was confirmed by mRNA-seq analysis, whereas immunoblotting and immunofluorescence confirmed Ingenuity pathway analysis-predicted changes for IL-6Rα and gp130/IL-6st. Conclusions: Male NOD mouse LG exhibit multiple dysregulated miRNAs owing to the presence of infiltrating immune cells, and decreased acinar cell content. The observed dysregulation may increase IL-6Rα and gp130/IL-6st on acini and IL-6Rα on specific lymphocytes, enhancing IL-6 and IL-6-like cytokine signaling.


Assuntos
Dacriocistite , Aparelho Lacrimal , MicroRNAs , Síndrome de Sjogren , Masculino , Feminino , Camundongos , Animais , Aparelho Lacrimal/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Modelos Animais de Doenças , Receptor gp130 de Citocina/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Síndrome de Sjogren/metabolismo , Dacriocistite/genética , Dacriocistite/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Camundongos Endogâmicos NOD
3.
Front Immunol ; 13: 833254, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35309364

RESUMO

Objective: The tear miRNAome of the male NOD mouse, a model of ocular symptoms of Sjögren's syndrome (SS), was analyzed to identify unique miRNAs. Methods: Male NOD mice, aged 12-14 weeks, were used to identify tear miRNAs associated with development of autoimmune dacryoadenitis. Age- and sex-matched male BALB/c mice served as healthy controls while age-matched female NOD mice that do not develop the autoimmune dacryoadenitis characteristic of SS were used as additional controls. Total RNA was isolated from stimulated tears pooled from 5 mice per sample and tear miRNAs were sequenced and analyzed. Putative miRNA hits were validated in additional mouse cohorts as well as in tears of SS patients versus patients with another form of dry eye disease, meibomian gland disease (MGD) using qRT-PCR. The pathways influenced by the validated hits were identified using Ingenuity Pathway Analysis. Results: In comparison to tears from both healthy (male BALB/c) and additional control (female NOD) mice, initial analy1sis identified 7 upregulated and 7 downregulated miRNAs in male NOD mouse tears. Of these, 8 were validated by RT-qPCR in tears from additional mouse cohorts. miRNAs previously implicated in SS pathology included mmu-miR-146a/b-5p, which were significantly downregulated, as well as mmu-miR-150-5p and mmu-miR-181a-5p, which were upregulated in male NOD mouse tears. All other validated hits including the upregulated miR-181b-5p and mmu-miR-203-3p, as well as the downregulated mmu-miR-322-5p and mmu-miR-503-5p, represent novel putative indicators of autoimmune dacryoadenitis in SS. When compared to tears from patients with MGD, miRNAs hsa-miR-203a-3p, hsa-miR-181a-5p and hsa-miR-181b-5p were also significantly increased in tears of SS patients. Conclusions: A panel of differentially expressed miRNAs were identified in tears of male NOD mice, with some preliminary validation in SS patients, including some never previously linked to SS. These may have potential utility as indicators of ocular symptoms of SS; evaluation of the pathways influenced by these dysregulated miRNAs may also provide further insights into SS pathogenesis.


Assuntos
Dacriocistite , MicroRNAs , Síndrome de Sjogren , Animais , Biomarcadores/metabolismo , Dacriocistite/genética , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , MicroRNAs/genética , Síndrome de Sjogren/diagnóstico , Síndrome de Sjogren/genética , Síndrome de Sjogren/metabolismo
4.
Biomacromolecules ; 23(1): 265-275, 2022 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-34914359

RESUMO

Dynamin (DNM) is a family of large GTPases possessing a unique mechanical ability to "pinch" off vesicles entering cells. DNM2 is the most ubiquitously expressed member of the DNM family. We developed a novel tool based on elastin-like polypeptide (ELP) technology to quickly, precisely, and reversibly modulate the structure of DNM2. ELPs are temperature-sensitive biopolymers that self-assemble into microdomains above sharp transition temperatures. When linked together, DNM2 and a temperature-sensitive ELP fusion organize into a range of distinct temperature-dependent structures above a sharp transition temperature, which were not observed with wild-type DNM2 or a temperature-insensitive ELP fusion control. The structures comprised three different morphologies, which were prevalent at different temperature ranges. The size of these structures was influenced by an inhibitor of the DNM2 GTPase activity, dynasore; furthermore, they appear to entrap co-expressed cytosolic ELPs. Having demonstrated an unexpected diversity of morphologically distinct structures, DNM2-ELP fusions may have applications in the exploration of dynamin-dependent biology.


Assuntos
Elastina , Peptídeos , Dinaminas , Elastina/química , Peptídeos/química , Temperatura , Temperatura de Transição
5.
Front Immunol ; 11: 1475, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32849505

RESUMO

Sjögren's Syndrome (SS) is an autoimmune disease characterized by lymphocytic infiltration and loss of function of moisture-producing exocrine glands as well as systemic inflammation. SS diagnosis is cumbersome, subjective and complicated by manifestation of symptoms that overlap with those of other rheumatic and ocular diseases. Definitive diagnosis averages 4-5 years and this delay may lead to irreversible tissue damage. Thus, there is an urgent need for diagnostic biomarkers for earlier detection of SS. Extracellular vesicles called exosomes carry functional small non-coding RNAs which play a critical role in maintaining cellular homeostasis via transcriptional and translational regulation of mRNA. Alterations in levels of specific exosomal miRNAs may be predictive of disease status. Here, we have assessed serum exosomal RNA using next generation sequencing in a discovery cohort of the NOD mouse, a model of early-intermediate SS, to identify dysregulated miRNAs that may be indicative of SS. We found five miRNAs upregulated in serum exosomes of NOD mice with an adjusted p < 0.05-miRNA-127-3p, miRNA-409-3p, miRNA-410-3p, miRNA-541-5p, and miRNA-540-5p. miRNAs 127-3p and 541-5p were also statistically significantly upregulated in a validation cohort of NOD mice. Pathway analysis and existing literature indicates that differential expression of these miRNAs may dysregulate pathways involved in inflammation. Future studies will apply these findings in a human cohort to understand how they are correlated with manifestations of SS as well as understanding their functional role in systemic autoimmunity specific to SS.


Assuntos
Biomarcadores/metabolismo , MicroRNA Circulante/genética , Exossomos/genética , Marcadores Genéticos/genética , Síndrome de Sjogren/diagnóstico , Animais , Modelos Animais de Doenças , Exossomos/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Inflamação/genética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , Transcriptoma
6.
ACS Biomater Sci Eng ; 6(1): 198-204, 2020 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-32542186

RESUMO

Caveolae are membrane organelles formed by submicron invaginations in the plasma membrane, and are involved in mechanosensing, cell signaling, and endocytosis. Although implicated broadly in physiology and pathophysiology, better tools are required to elucidate the precise role of caveolar processes through selective activation and inactivation of their trafficking. Our group recently reported that thermally-responsive elastin-like polypeptides (ELPs) can trigger formation of 'genetically engineered protein microdomains (GEPMs)' functionalized with either Clathrin-light chain or the epidermal growth factor receptor. This manuscript is the first report of this strategy to modulate caveolin-1 (CAV1). By attaching different ELP sequences to CAV1, mild heating can be used to self-assemble CAV1-ELP microdomains inside of cells. The temperature of self-assembly can be controlled by tuning the ELP sequence. The formation of CAV1-ELP microdomains internalizes Cholera Toxin Subunit B, a commonly used marker of caveolae mediated endocytosis. CAV1-ELPs also colocalize with Cavin 1, an essential component of functional caveolae biogenesis. With the emerging significance of caveolae in health and disease and the lack of specific probes to rapidly and reversibly affect caveolar function, CAV1-ELP microdomains are a new tool to rapidly probe caveolae associated processes in endocytosis, cell signaling, and mechanosensing.


Assuntos
Cavéolas , Caveolina 1 , Cavéolas/metabolismo , Caveolina 1/genética , Elastina , Endocitose , Temperatura
7.
Int J Biol Sci ; 16(9): 1507-1525, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32226298

RESUMO

Protein-protein interactions are key to define the function of nucleotide binding domain (NBD) and leucine-rich repeat (LRR) family, pyrin domain (PYD)-containing protein 12 (NLRP12). cDNA encoding the human PYD + NBD of NLRP12 was used as bait in a yeast two-hybrid screen with a human leukocyte cDNA library as prey. Hematopoiesis cell kinase (HCK), a member of the c-SRC family of non-receptor tyrosine kinases, was among the top hits. The C-terminal 40 amino acids of HCK selectively bound to NLRP12's PYD + NBD, but not to that of NLRP3 and NLRP8. Amino acids F503, I506, Q507, L510, and D511 of HCK are critical for the binding of HCK's C-terminal 40 amino acids to NLRP12's PYD + NBD. Additionally, the C-terminal 30 amino acids of HCK are sufficient to bind to NLRP12's PYD + NBD, but not to its PYD alone nor to its NBD alone. In cell lines that express HCK endogenously, it was co- immunoprecipitated with stably expressed exogenous NLRP12. Also, NLRP12 co-immunoprecipitated and co-localized with HCK when both were overexpressed in 293T cells. In addition, in this overexpression system, steady-state NLRP12 protein expression levels significantly decreased when HCK was co-expressed. Bioinformatic analysis showed that HCK mRNA co-occurred with NLRP12 mRNA, but not with other NLRP mRNAs, in blood and marrow samples from acute myeloid leukemia (AML) patients. The mRNA of NLRP12 is also co-expressed with HCK in AML patient samples, and the levels of mRNA expression of each are correlated. Together these data suggest that NLRP12, through its binding to HCK, may have an effect on the pathogenesis of AML.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Proto-Oncogênicas c-hck/metabolismo , Medula Óssea/metabolismo , Linhagem Celular , Células HEK293 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/sangue , Peptídeos e Proteínas de Sinalização Intracelular/química , Peptídeos e Proteínas de Sinalização Intracelular/genética , Leucemia Mieloide Aguda/sangue , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteínas Proto-Oncogênicas c-hck/sangue , Proteínas Proto-Oncogênicas c-hck/química , Proteínas Proto-Oncogênicas c-hck/genética , Técnicas do Sistema de Duplo-Híbrido
8.
FASEB J ; 34(5): 6729-6740, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32248607

RESUMO

The extracellular matrix (ECM) is comprised of a large network of proteins that are essential for tissue development and repair. A bioactive RGD-containing peptide from laminin α1 chain, A99 (AGTFALRGDNPQG), promotes strong cell attachment and has demonstrated utility in cell culture and tissue engineering. Various materials can be utilized as a scaffold for bioactive peptides; however, it may be advantageous to design materials that use bioconjugation strategies that do not affect bioactivity, generate homogenous products, and can be produced at scale. This report is the first to compare the methods for preparing chemically conjugated and recombinant A99 to elastin-like polypeptides (ELPs) as the scaffold and characterize the biological and cell attachment activity using human dermal fibroblasts (HDFs). ELPs are biocompatible protein-polymers that are also thermo-responsive. Below a lower critical solution temperature (LCST), they are highly soluble. Above the LCST, ELPs phase separate into a polymer-rich liquid, known as a coacervate. Both chemically conjugated and recombinant fusion between A99 and an ELP (A99-ELP-R) show dose-dependent cell attachment. In addition, coating above the LCST provides better cell spreading compared to coating at 4°C. ELPs provide an excellent structural framework for deposition of bioactive peptides of the ECM, and their intrinsic biophysical properties make laminin peptide-ELPs promising biomaterials for cell culture and tissue engineering.


Assuntos
Adesão Celular , Elastina/metabolismo , Matriz Extracelular/metabolismo , Fibroblastos/efeitos dos fármacos , Laminina/metabolismo , Peptídeos/farmacologia , Materiais Biocompatíveis/química , Fibroblastos/metabolismo , Humanos , Engenharia Tecidual
9.
Biomark Med ; 14(2): 151-163, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32064896

RESUMO

Tears are a known source of biomarkers for both ocular and systemic diseases with particular advantages; specifically, the noninvasiveness of sample collection and a unique and increasingly better-defined protein composition. Here, we discuss our rationale for use of tears for discovery of biomarkers for Parkinson's disease (PD). These reasons include literature supporting changes in tear flow and composition in PD, and the interconnections between the ocular surface system and neurons affected in PD. We highlight recent data on the identification of tear biomarkers including oligomeric α-synuclein, associated with neuronal degeneration in PD, in tears of PD patients and discuss possible sources for its release into tears. Challenges and next steps for advancing such biomarkers to clinical usage are highlighted.


Assuntos
Biomarcadores/metabolismo , Doença de Parkinson/metabolismo , Lágrimas/metabolismo , alfa-Sinucleína/metabolismo , Humanos , Aparelho Lacrimal/metabolismo , Neurônios/metabolismo , Doença de Parkinson/diagnóstico , Multimerização Proteica , Transporte Proteico , Sensibilidade e Especificidade , alfa-Sinucleína/química
10.
Biomark Med ; 13(17): 1447-1457, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31552762

RESUMO

Aim: Due to active engagement of sensory and afferent nerve fibers in reflex tearing which could be affected in Parkinson's disease (PD), we tested reflex tears as a source of potential PD biomarkers. Patients & methods: Reflex tears collected from 84 PD and 84 age- and sex-equivalent healthy controls (HC) were used to measure levels of oligomeric α-Syn (α-SynOligo), total α-Syn (α-SynTotal), CCL2, DJ-1, lactoferrin and MMP9. Results: α-synOligo (p < 0.0001), CCL2 (p = 0.003) and lactoferrin (p = 0.002) were significantly elevated in PD patient tears relative to HC tears. Tear flow was significantly lower in PD relative to HC (p = 0.001). Conclusion: Reflex tears are a potential source for detection of characteristic changes in PD patients.


Assuntos
Biomarcadores/análise , Doença de Parkinson/diagnóstico , Lágrimas/química , alfa-Sinucleína/química , Idoso , Biomarcadores/metabolismo , Estudos de Casos e Controles , Quimiocina CCL2/análise , Quimiocina CCL2/metabolismo , Feminino , Humanos , Lactoferrina/análise , Lactoferrina/metabolismo , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/metabolismo , Lágrimas/metabolismo
11.
Biomark Med ; 13(11): 941-952, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31262201

RESUMO

Aim: Secretion of proteins into basal tears of Parkinson's disease (PD) patients may be altered by changes in nerve function. Materials & methods: Oligomeric α-SynOligo and total α-SynTotal, CCL-2, DJ-1, LF and MMP-9 were measured in basal tears from 93 PD patients and 82 age- and sex-equivalent healthy controls. Results: α-SynTotal was decreased (p = 0.0043), whereas α-SynOligo (p < 0.0001) and the ratio of α-SynOligo/α-SynTotal (p < 0.0001) were increased in basal tears from PD patients compared with healthy controls. Area under receiver-operating curves of α-SynOligo and α-SynOligo/α-SynTotal contents were 0.70 (95% confidence limits: 0.621-0.774) and 0.72 (95% confidence limits: 0.642-0.792). Conclusion: PD patient basal tears may contain biomarkers that can be assayed noninvasively and inexpensively.


Assuntos
Biomarcadores/análise , Doença de Parkinson/metabolismo , Lágrimas/química , alfa-Sinucleína/metabolismo , Idoso , Biomarcadores/metabolismo , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Lágrimas/metabolismo , alfa-Sinucleína/análise
12.
Biomaterials ; 183: 319-330, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30196151

RESUMO

The dynamic manipulation of kinases remains a major obstacle to unraveling cell-signaling networks responsible for the activation of biological systems. For example, epidermal growth factor (EGF) stimulates the epidermal growth factor receptor (EGFR/ErbB1); however, EGF also recruits other kinases (HER2/ErbB2) involved with various signaling pathways. To better study EGFR we report a new strategy to selectively activate receptor tyrosine kinases fused to elastin-like polypeptides (ELPs), which can be visualized inside mammalian cells using fixed and live-cell fluorescence microscopy. ELPs are high molecular weight polypeptides that phase separate abruptly upon heating. When an EGFR-ELP fusion is heated, it clusters, initiates receptor internalization, phosphorylates, initiates downstream kinase signaling, and undergoes retrograde transport towards the cell body. Unlike other strategies to block EGFR (small molecule inhibitors, RNAi, or transcriptional regulators), EGFR-ELP clustering can be specifically switched on or off within minutes. Live-cell imaging suggests that EGFR-ELPs assemble in most cells with only a 3 °C increase in temperature. This strategy was found reversible and able to dynamically control the downstream phosphorylation/activation of the ERK1/2 pathway. For the first time, this strategy enables the rational engineering of specific temperature-sensitive receptors that may have broad applications in the study and manipulation of biological processes.


Assuntos
Fator de Crescimento Epidérmico/metabolismo , Receptores ErbB/metabolismo , Peptídeos/metabolismo , Linhagem Celular Tumoral , Fator de Crescimento Epidérmico/química , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Humanos , Microscopia de Fluorescência/métodos , Peptídeos/genética , Fosforilação , Proteínas Tirosina Quinases/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Temperatura , Transfecção
13.
Hepatol Commun ; 1(2): 153-167, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29152604

RESUMO

Liver kinase B 1 (LKB1 or STK11) and PTEN (phosphatase and tensin homologue deleted on chromosome 10) are two tumor suppressors that regulate the mTOR signaling pathway. Deletion studies show that loss of either Lkb1 (Lkb+/- ) or Pten (PtenloxP/loxP; Alb-Cre+ ) leads to liver injury and development of hepatocarcinoma. In this study, we investigated the crosstalk of LKB1 and PTEN loss during tumorigenesis and liver development. We show here that haplo-insufficiency of Lkb1 in the liver leads to advanced tumor development in the Pten null mice (PtenloxP/loxP; LkbloxP/+; Alb-Cre+ ). Our analysis shows that LKB1 and PTEN interacted with each other in their regulation of fatty acid synthase as well as p21 expression. The combined loss of LKB1 and PTEN (PtenloxP/loxP; LkbloxP/loxP; Alb-Cre+ ) also led to the inability to form zonal structures in the liver. The lack of metabolic zonal structures is consistent with the inability of the livers to store glycogen as well as elevated plasma bilirubin and alanine aminotransferase (ALT), indicative of liver dysfunction. These structural and functional defects are associated with cytoplasm distribution of a canalicular membrane protein MRP2 (multidrug resistant protein 2) which is responsible for clearing bilirubin. This observed regulation of MRP2 by LKB1 likely contributed to the lack of cellular polarity and the early lethality phenotype associated with homozygous loss of Lkb1 alone or in combination with Pten. Finally, Pten deletion does not rescue the precocious ductal plate formation reported for Lkb1 deleted livers. CONCLUSION: Our study dissected the functional and molecular crosstalk of PTEN and LKB1 and elucidate key molecular targets for such interaction.

14.
Artigo em Inglês | MEDLINE | ID: mdl-28246186

RESUMO

The vectorial secretion and absorption of fluid and solutes by epithelial cells is dependent on the polarized expression of membrane solute transporters and channels at the apical and basolateral membranes. The establishment and maintenance of this polarized expression of transporters and channels are affected by divers protein-trafficking complexes. Moreover, regulation of the magnitude of transport is often under control of physiological stimuli, again through the interaction of transporters and channels with protein-trafficking complexes. This review highlights the value in utilizing transporters and channels as cargo to characterize core trafficking machinery by which epithelial cells establish and maintain their polarized expression, and how this machinery regulates fluid and solute transport in response to physiological stimuli.


Assuntos
Canais Iônicos/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Animais , Células Epiteliais/metabolismo , Humanos , Ligação Proteica , Transporte Proteico
15.
Biomaterials ; 117: 24-31, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27923197

RESUMO

Fc fusion protein technology has been successfully used to generate long-acting forms of several protein therapeutics. In this study, a novel Fc-based drug carrier, single chain Fc-dimer (sc(Fc)2), was designed to contain two Fc domains recombinantly linked via a flexible linker. Since the Fc dimeric structure is maintained through the flexible linker, the hinge region was omitted to further stabilize it against proteolysis and reduce FcγR-related effector functions. The resultant sc(Fc)2 candidate preserved the neonatal Fc receptor (FcRn) binding. sc(Fc)2-mediated delivery was then evaluated using a therapeutic protein with a short plasma half-life, human growth hormone (hGH), as the protein drug cargo. This novel carrier protein showed a prolonged in vivo half-life and increased hGH-mediated bioactivity compared to the traditional Fc-based drug carrier. sc(Fc)2 technology has the potential to greatly advance and expand the use of Fc-technology for improving the pharmacokinetics and bioactivity of protein therapeutics.


Assuntos
Antígenos de Histocompatibilidade Classe I/metabolismo , Hormônio do Crescimento Humano/administração & dosagem , Fragmentos Fc das Imunoglobulinas/metabolismo , Terapia de Alvo Molecular/métodos , Receptores Fc/metabolismo , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/farmacocinética , Animais , Estabilidade de Medicamentos , Sinergismo Farmacológico , Células HEK293 , Hormônio do Crescimento Humano/química , Humanos , Fragmentos Fc das Imunoglobulinas/administração & dosagem , Fragmentos Fc das Imunoglobulinas/genética , Taxa de Depuração Metabólica , Camundongos , Proteínas Recombinantes de Fusão/genética , Distribuição Tecidual
16.
Am J Physiol Cell Physiol ; 310(11): C942-54, 2016 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-27076615

RESUMO

The mechanism responsible for the altered spectrum of tear proteins secreted by lacrimal gland acinar cells (LGAC) in patients with Sjögren's Syndrome (SS) remains unknown. We have previously identified increased cathepsin S (CTSS) activity as a unique characteristic of tears of patients with SS. Here, we investigated the role of Rab3D, Rab27a, and Rab27b proteins in the enhanced release of CTSS from LGAC. Similar to patients with SS and to the male nonobese diabetic (NOD) mouse model of SS, CTSS activity was elevated in tears of mice lacking Rab3D. Findings of lower gene expression and altered localization of Rab3D in NOD LGAC reinforce a role for Rab3D in suppressing excess CTSS release under physiological conditions. However, CTSS activity was significantly reduced in tears of mice lacking Rab27 isoforms. The reliance of CTSS secretion on Rab27 activity was supported by in vitro findings that newly synthesized CTSS was detected in and secreted from Rab27-enriched secretory vesicles and that expression of dominant negative Rab27b reduced carbachol-stimulated secretion of CTSS in cultured LGAC. High-resolution 3D-structured illumination microscopy revealed microdomains of Rab3D and Rab27 isoforms on the same secretory vesicles but present in different proportions on different vesicles, suggesting that changes in their relative association with secretory vesicles may tailor the vesicle contents. We propose that a loss of Rab3D from secretory vesicles, leading to disproportionate Rab27-to-Rab3D activity, may contribute to the enhanced release of CTSS in tears of patients with SS.


Assuntos
Catepsinas/metabolismo , Aparelho Lacrimal/enzimologia , Síndrome de Sjogren/enzimologia , Lágrimas/enzimologia , Proteínas rab de Ligação ao GTP/metabolismo , Proteínas rab3 de Ligação ao GTP/metabolismo , Animais , Carbacol/farmacologia , Catepsinas/genética , Células Cultivadas , Modelos Animais de Doenças , Genótipo , Aparelho Lacrimal/efeitos dos fármacos , Aparelho Lacrimal/metabolismo , Masculino , Microdomínios da Membrana/enzimologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Fenótipo , Coelhos , Vesículas Secretórias/enzimologia , Síndrome de Sjogren/genética , Lágrimas/efeitos dos fármacos , Lágrimas/metabolismo , Transfecção , Proteínas rab de Ligação ao GTP/deficiência , Proteínas rab de Ligação ao GTP/genética , Proteínas rab27 de Ligação ao GTP , Proteínas rab3 de Ligação ao GTP/deficiência , Proteínas rab3 de Ligação ao GTP/genética
17.
Adv Funct Mater ; 24(34): 5340-5347, 2014 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-25419208

RESUMO

A ubiquitous approach to study protein function is to knock down activity (gene deletions, siRNA, small molecule inhibitors, etc) and study the cellular effects. Using a new methodology, this manuscript describes how to rapidly and specifically switch off cellular pathways using thermally responsive protein polymers. A small increase in temperature stimulates cytosolic elastin-like polypeptides (ELPs) to assemble microdomains. We hypothesize that ELPs fused to a key effector in a target macromolecular complex will sequester the complex within these microdomains, which will bring the pathway to a halt. To test this hypothesis, we fused ELPs to clathrin-light chain (CLC), a protein associated with clathrin-mediated endocytosis. Prior to thermal stimulation, the ELP fusion is soluble and clathrin-mediated endocytosis remains 'on.' Increasing the temperature induces the assembly of ELP fusion proteins into organelle-sized microdomains that switches clathrin-mediated endocytosis 'off.' These microdomains can be thermally activated and inactivated within minutes, are reversible, do not require exogenous chemical stimulation, and are specific for components trafficked within the clathrin-mediated endocytosis pathway. This temperature-triggered cell switch system represents a new platform for the temporal manipulation of trafficking mechanisms in normal and disease cell models and has applications for manipulating other intracellular pathways.

18.
Am J Physiol Gastrointest Liver Physiol ; 306(8): G699-710, 2014 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-24578340

RESUMO

Selective inhibitors of myosin or actin function and confocal microscopy were used to test the role of an actomyosin complex in controlling morphology, trafficking, and fusion of tubulovesicles (TV) containing H-K-ATPase with the apical secretory canaliculus (ASC) of primary-cultured rabbit gastric parietal cells. In resting cells, myosin IIB and IIC, ezrin, and F-actin were associated with ASC, whereas H-K-ATPase localized to intracellular TV. Histamine caused fusion of TV with ASC and subsequent expansion resulting from HCl and water secretion; F-actin and ezrin remained associated with ASC whereas myosin IIB and IIC appeared to dissociate from ASC and relocalize to the cytoplasm. ML-7 (inhibits myosin light chain kinase) caused ASC of resting cells to collapse and most myosin IIB, F-actin, and ezrin to dissociate from ASC. TV were unaffected by ML-7. Jasplakinolide (stabilizes F-actin) caused ASC to develop large blebs to which actin, myosin II, and ezrin, as well as tubulin, were prominently localized. When added prior to stimulation, ML-7 and jasplakinolide prevented normal histamine-stimulated transformations of ASC/TV and the cytoskeleton, but they did not affect cells that had been previously stimulated with histamine. These results indicate that dynamic pools of actomyosin are required for maintenance of ASC structure in resting cells and for trafficking of TV to ASC during histamine stimulation. However, the dynamic pools of actomyosin are not required once the histamine-stimulated transformation of TV/ASC and cytoskeleton has occurred. These results also show that vesicle trafficking in parietal cells shares mechanisms with similar processes in renal collecting duct cells, neuronal synapses, and skeletal muscle.


Assuntos
Actinas/metabolismo , Miosina não Muscular Tipo IIB/metabolismo , Células Parietais Gástricas , Vesículas Transportadoras , Animais , Azepinas/farmacologia , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/fisiologia , Fenômenos Fisiológicos Celulares/efeitos dos fármacos , Células Cultivadas , Inibidores Enzimáticos/farmacologia , ATPase Trocadora de Hidrogênio-Potássio/metabolismo , Naftalenos/farmacologia , Células Parietais Gástricas/metabolismo , Células Parietais Gástricas/patologia , Coelhos , Vesículas Transportadoras/efeitos dos fármacos , Vesículas Transportadoras/fisiologia
20.
Am J Pharm Educ ; 77(5): 95, 2013 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-23788806

RESUMO

OBJECTIVES: To examine changes in preprofessional pharmacy curricular requirements and trends, and determine rationales for and implications of modifications. METHODS: Prerequisite curricular requirements compiled between 2006 and 2011 from all doctor of pharmacy (PharmD) programs approved by the Accreditation Council of Pharmacy Education were reviewed to ascertain trends over the past 5 years. An online survey was conducted of 20 programs that required either 3 years of prerequisite courses or a bachelor's degree, and a random sample of 20 programs that required 2 years of prerequisites. Standardized telephone interviews were then conducted with representatives of 9 programs. RESULTS: In 2006, 4 programs required 3 years of prerequisite courses and none required a bachelor's degree; by 2011, these increased to 18 programs and 7 programs, respectively. Of 40 programs surveyed, responses were received from 28 (70%), 9 (32%) of which reported having increased the number of prerequisite courses since 2006. Reasons given for changes included desire to raise the level of academic achievement of students entering the PharmD program, desire to increase incoming student maturity, and desire to add clinical sciences and experiential coursework to the pharmacy curriculum. Some colleges and schools experienced a temporary decrease in applicants. CONCLUSIONS: The preprofessional curriculum continues to evolve, with many programs increasing the number of course prerequisites. The implications of increasing prerequisites were variable and included a perceived increase in maturity and quality of applicants and, for some schools, a temporary decrease in the number of applicants.


Assuntos
Educação em Farmácia/tendências , Critérios de Admissão Escolar/tendências , Faculdades de Farmácia/tendências , Acreditação/tendências , Currículo/tendências , Coleta de Dados , Educação em Farmácia/normas , Humanos , Internet , Entrevistas como Assunto , Desenvolvimento de Programas , Faculdades de Farmácia/normas , Sociedades Farmacêuticas/tendências , Telefone , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...