Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 147
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Nucleic Acids Res ; 52(3): 1120-1135, 2024 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-38038265

RESUMEN

Common fragile sites (CFSs) are regions prone to chromosomal rearrangements, thereby contributing to tumorigenesis. Under replication stress (RS), CFSs often harbor under-replicated DNA regions at the onset of mitosis, triggering homology-directed repair known as mitotic DNA synthesis (MiDAS) to complete DNA replication. In this study, we identified an important role of DNA mismatch repair protein MutSß (MSH2/MSH3) in facilitating MiDAS and maintaining CFS stability. Specifically, we demonstrated that MutSß is required for the increased mitotic recombination induced by RS or FANCM loss at CFS-derived AT-rich and structure-prone sequences (CFS-ATs). We also found that MSH3 exhibits synthetic lethality with FANCM. Mechanistically, MutSß is required for homologous recombination (HR) especially when DNA double-strand break (DSB) ends contain secondary structures. We also showed that upon RS, MutSß is recruited to Flex1, a specific CFS-AT, in a PCNA-dependent but MUS81-independent manner. Furthermore, MutSß interacts with RAD52 and promotes RAD52 recruitment to Flex1 following MUS81-dependent fork cleavage. RAD52, in turn, recruits XPF/ERCC1 to remove DNA secondary structures at DSB ends, enabling HR/break-induced replication (BIR) at CFS-ATs. We propose that the specific requirement of MutSß in processing DNA secondary structures at CFS-ATs underlies its crucial role in promoting MiDAS and maintaining CFS integrity.


Asunto(s)
Roturas del ADN de Doble Cadena , Reparación del ADN , Reparación del ADN/genética , Replicación del ADN/genética , Reparación del ADN por Recombinación , ADN/genética , ADN/metabolismo , Proteínas/genética
2.
J Biol Chem ; 299(1): 102770, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36470428

RESUMEN

G-quadruplex (G4)-forming DNA sequences are abundant in the human genome, and they are hot spots for inducing DNA double-strand breaks (DSBs) and genome instability. The mechanisms involved in protecting G4s and maintaining genome stability have not been fully elucidated. Here, we demonstrated that RAD52 plays an important role in suppressing DSB accumulation at G4s, and RAD52-deficient cells are sensitive to G4-stabilizing compounds. Mechanistically, we showed that RAD52 is required for efficient homologous recombination repair at G4s, likely due to its function in recruiting structure-specific endonuclease XPF to remove G4 structures at DSB ends. We also demonstrated that upon G4 stabilization, endonuclease MUS81 mediates cleavage of stalled replication forks at G4s. The resulting DSBs recruit RAD52 and XPF to G4s for processing DSB ends to facilitate homologous recombination repair. Loss of RAD52 along with G4-resolving helicase FANCJ leads to a significant increase of DSB accumulation before and after treatment with the G4-stabilizing compound pyridostatin, and RAD52 exhibits a synthetic lethal interaction with FANCJ. Collectively, our findings reveal a new role of RAD52 in protecting G4 integrity and provide insights for new cancer treatment strategies.


Asunto(s)
G-Cuádruplex , Proteína Recombinante y Reparadora de ADN Rad52 , Animales , Humanos , ADN Helicasas/genética , ADN Helicasas/metabolismo , Endonucleasas/metabolismo , Inestabilidad Genómica , Proteína Recombinante y Reparadora de ADN Rad52/genética , Proteína Recombinante y Reparadora de ADN Rad52/metabolismo , Reparación del ADN por Recombinación/genética
3.
J Am Chem Soc ; 146(1): 419-429, 2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-38155363

RESUMEN

Currently, hydrogen peroxide (H2O2) manufacturing involves an energy-intensive anthraquinone technique that demands expensive solvent extraction and a multistep process with substantial energy consumption. In this work, we synthesized Pd-N4-CO, Pd-S4-NCO, and Pd-N2O2-C single-atom catalysts via an in situ synthesis approach involving heteroatom-rich ligands and activated carbon under mild reaction conditions. It reveals that palladium atoms interact strongly with heteroatom-rich ligands, which provide well-defined and uniform active sites for oxygen (O2) electrochemically reduced to hydrogen peroxide. Interestingly, the Pd-N4-CO electrocatalyst shows excellent performance for the electrocatalytic reduction of O2 to H2O2 via a two-electron transfer process in a base electrolyte, exhibiting a negligible amount of onset overpotential and >95% selectivity within a wide range of applied potentials. The electrocatalysts based on the activity and selectivity toward 2e- ORR follow the order Pd-N4-CO > Pd-N2O2-C > Pd-S4-NCO in agreement with the pull-push mechanism, which is the Pd center strongly coordinated with high electronegativity donor atoms (N and O atoms) and weakly coordinated with the intermediate *OOH to excellent selectivity and sustainable production of H2O2. According to density functional theory, Pd-N4 is the active site for selectivity toward H2O2 generation. This work provides an emerging technique for designing high-performance H2O2 electrosynthesis catalysts and the rational integration of several active sites for green and sustainable chemical synthesis via electrochemical processes.

4.
PLoS Pathog ; 18(11): e1010931, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36350837

RESUMEN

African swine fever virus (ASFV) is causing a worldwide pandemic affecting the porcine industry and leading to important global economic consequences. The virus causes a highly lethal hemorrhagic disease in wild boars and domestic pigs. Lack of effective vaccines hampers the control of virus spread, thus increasing the pressure on the scientific community for urgent solutions. However, knowledge on the immune components associated with protection is very limited. Here we characterized the in vitro recall response induced by immune cells from pigs intranasally vaccinated with the BA71ΔCD2 deletion mutant virus. Vaccination conferred dose-dependent cross-protection associated with both ASFV-specific antibodies and IFNγ-secreting cells. Importantly, bulk and single-cell transcriptomics of blood and lymph node cells from vaccinated pigs revealed a positive feedback from adaptive to innate immunity. Indeed, activation of Th1 and cytotoxic T cells was concomitant with a rapid IFNγ-dependent triggering of an inflammatory response characterized by TNF-producing macrophages, as well as CXCL10-expressing lymphocytes and cross-presenting dendritic cells. Altogether, this study provides a detailed phenotypic characterization of the immune cell subsets involved in cross-protection against ASFV, and highlights key functional immune mechanisms to be considered for the development of an effective ASF vaccine.


Asunto(s)
Virus de la Fiebre Porcina Africana , Fiebre Porcina Africana , Vacunas Virales , Porcinos , Animales , Proteínas Virales , Sus scrofa , Vacunación , Inmunidad Innata
5.
Exp Eye Res ; 244: 109932, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38762008

RESUMEN

Drugs that can treat one disease may either be detrimental or beneficial toward another due to possible cross-interactions. Therefore, care in choosing a suitable drug for patients with multiple diseases is crucial in successful patient management. This study explores several currently available ophthalmic drugs used to treat common ocular diseases to understand how they can affect the amyloidogenesis of a transforming growth factor ß-induced protein (TGFBIp) peptide fragment found in abundance in the corneal protein aggregation deposits of lattice corneal dystrophy (LCD) patients. Results from this study provided supporting evidence that some drugs intended to treat other diseases can enhance or inhibit fibrillar aggregation of TGFBIp peptide, which may have potential implication of affecting the disease progression of LCD by either worsening or ameliorating it. Comparisons of the different properties of ophthalmic compounds explored in this study may also provide some guidance for future design of drugs geared toward the treatment of LCD.


Asunto(s)
Distrofias Hereditarias de la Córnea , Proteínas de la Matriz Extracelular , Factor de Crecimiento Transformador beta , Humanos , Proteínas de la Matriz Extracelular/metabolismo , Distrofias Hereditarias de la Córnea/metabolismo , Distrofias Hereditarias de la Córnea/tratamiento farmacológico , Factor de Crecimiento Transformador beta/metabolismo , Fragmentos de Péptidos/farmacología , Fragmentos de Péptidos/metabolismo , Soluciones Oftálmicas , Amiloide/metabolismo
6.
Nanotechnology ; 35(17)2024 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-38262054

RESUMEN

Heparins are a family of sulfated linear negatively charged polysaccharides that have been widely used for their anticoagulant, antithrombotic, antitumor, anti-inflammatory, and antiviral properties. Additionally, it has been used for acute cerebral infarction relief as well as other pharmacological actions. However, heparin's self-aggregated macrocomplex may reduce blood circulation time and induce life-threatening thrombocytopenia (HIT) complicating the use of heparins. Nonetheless, the conjugation of heparin to immuno-stealth biomolecules may overcome these obstacles. An immunostealth recombinant viral capsid protein (VP28) was expressed and conjugated with heparin to form a novel nanoparticle (VP28-heparin). VP28-heparin was characterized and tested to determine its immunogenicity, anticoagulation properties, effects on total platelet count, and risk of inducing HIT in animal models. The synthesized VP28-heparin trimeric nanoparticle was non-immunogenic, possessed an average hydrodynamic size (8.81 ± 0.58 nm) optimal for the evasion renal filtration and reticuloendothelial system uptake (hence prolonging circulating half-life). Additionally, VP28-heparin did not induce mouse death or reduce blood platelet count when administered at a high dosein vivo(hence reducing HIT risks). The VP28-heparin nanoparticle also exhibited superior anticoagulation properties (2.2× higher prothrombin time) and comparable activated partial thromboplastin time, but longer anticoagulation period when compared to unfractionated heparin. The anticoagulative effects of the VP28-heparin can also be reversed using protamine sulfate. Thus, VP28-heparin may be an effective and safe heparin derivative for therapeutic use.


Asunto(s)
Heparina , Trombocitopenia , Animales , Ratones , Heparina/farmacología , Heparina/uso terapéutico , Anticoagulantes/farmacología , Coagulación Sanguínea , Trombocitopenia/tratamiento farmacológico , Recuento de Plaquetas
7.
Small ; : e2307180, 2023 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-38054789

RESUMEN

Despite the unique advantages of single-atom catalysts, molecular dual-active sites facilitate the C-C coupling reaction for C2 products toward the CO2 reduction reaction (CO2 RR). The Ni/Cu proximal dual-active site catalyst (Ni/Cu-PASC) is developed, which is a harmonic catalyst with dual-active sites, by simply mixing commercial Ni-phthalocyanine (Ni-Pc) and Cu-phthalocyanine (Cu-Pc) molecules physically. According to scanning transmission electron microscopy (STEM) and transmission electron microscopy (TEM) energy dispersive spectroscopy (EDS) data, Ni and Cu atoms are separated, creating dual-active sites for the CO2 RR. The Ni/Cu-PASC generates ethanol with an FE of 55%. Conversely, Ni-Pc and Cu-Pc have only detected single-carbon products like CO and HCOO- . In situ X-ray absorption spectroscopy (XAS) indicates that CO generation is caused by the stable Ni active site's balanced electronic state. The CO production from Ni-Pc consistently increased the CO concentration over Cu sites attributed to subsequent reduction reaction through a C-C coupling on nearby Cu. The CO bound (HCOO- ) peak, which can be found on Cu-Pc, vanishes on Ni/Cu-PASC, as shown by in situ fourier transformation infrared (FTIR). The characteristic intermediate of *CHO instead of HCOO- proves to be the prerequisite for multi-carbon products by electrochemical CO2 RR. The work demonstrates that the harmonic dual-active sites in Ni/Cu-PASC can be readily available by the cascading proximal active Ni- and Cu-Pc sites.

8.
J Fish Dis ; 46(6): 611-617, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36848405

RESUMEN

Baculovirus penaei (BP), the causative agent of tetrahedral baculovirosis, causes the death of penaeid genera at the larval and post-larval stages. BP has been reported in the Western Pacific, South-East Atlantic, and the State of Hawaii, but never in Asia. The clinical features of BP infection are non-specific, and diagnosis relies on histological and molecular methods. In the present study, we report the first identification of BP infection in a shrimp farm in Northern Taiwan in 2022. Histopathologically, several tetrahedral eosinophilic intranuclear occlusion bodies were observed in or budding out of the nuclei of the degenerative hepatopancreatic cells. In situ hybridization and polymerase chain reaction confirmed tetrahedral baculovirosis infection caused by BP. Sequence alignment of the TW BP-1 with the USA BP strain reported in 1995 revealed 94.81% identity in the partial gene. The possibility of the emergence of USA-like BP in Taiwan highlights the importance of further epidemiological investigations on the prevalence and impact of BP in Asia.


Asunto(s)
Enfermedades de los Peces , Penaeidae , Animales , Taiwán/epidemiología , Genómica , Baculoviridae/genética
9.
Int J Mol Sci ; 24(5)2023 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-36901874

RESUMEN

Diabetes nephropathy (DN) is one of the most common causes of end stage renal disease (ESRD) globally. Medication options to stop or slow the progression of chronic renal disease (CKD) are limited, and patients with DN remain at a high risk of developing renal failure. Inonotus obliquus extracts (IOEs) of Chaga mushroom have been shown to have anti-glycemic, anti-hyperlipidemia, antioxidant, and anti-inflammatory effects against diabetes. In this study, we examined the potential renal protective role of an ethyl acetate layer after water-ethyl acetate separation from Inonotus obliquus ethanol crude extract (EtCE-EA) from Chaga mushrooms in diabetic nephropathy mice after preparation with 1/3 NT + STZ. Our data showed that treatment with EtCE-EA can effectively regulate blood glucose, albumin-creatinine ratio, serum creatinine, and blood urea nitrogen (BUN) levels, and it can improve the renal damage in 1/3 NT + STZ-induced CRF mice with an increase in concentration (100, 300, and 500 mg/kg). In the immunohistochemical staining test, EtCE-EA can effectively reduce the expression of TGF-ß and α-SMA after induction according to the increase in the concentration (100 mg/kg, 300 mg/kg), thereby slowing down the degree of kidney damage. Our findings demonstrate that EtCE-EA could provide renal protection in diabetes nephropathy, possibly due to the decreased expression of transforming growth factor-ß1 and α-smooth muscle actin.


Asunto(s)
Diabetes Mellitus , Nefropatías Diabéticas , Ratones , Animales , Nefropatías Diabéticas/metabolismo , Estreptozocina/farmacología , Riñón/metabolismo , Nefrectomía/efectos adversos , Diabetes Mellitus/metabolismo
10.
Int J Mol Sci ; 24(2)2023 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-36674860

RESUMEN

Surface contamination by microorganisms such as viruses and bacteria may simultaneously aggravate the biofouling of surfaces and infection of wounds and promote cross-species transmission and the rapid evolution of microbes in emerging diseases. In addition, natural surface structures with unique anti-biofouling properties may be used as guide templates for the development of functional antimicrobial surfaces. Further, these structure-related antimicrobial surfaces can be categorized into microbicidal and anti-biofouling surfaces. This review introduces the recent advances in the development of microbicidal and anti-biofouling surfaces inspired by natural structures and discusses the related antimicrobial mechanisms, surface topography design, material application, manufacturing techniques, and antimicrobial efficiencies.


Asunto(s)
Antiinfecciosos , Incrustaciones Biológicas , Antiinfecciosos/farmacología , Antiinfecciosos/química , Bacterias , Propiedades de Superficie
11.
Int J Mol Sci ; 24(4)2023 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-36835312

RESUMEN

Peroxisome proliferator-activated receptor γ (PPARγ) gene mutations in humans and mice lead to whole-body insulin resistance and partial lipodystrophy. It is unclear whether preserved fat depots in partial lipodystrophy are beneficial for whole-body metabolic homeostasis. We analyzed the insulin response and expression of metabolic genes in the preserved fat depots of PpargC/- mice, a familial partial lipodystrophy type 3 (FPLD3) mouse model resulting from a 75% decrease in Pparg transcripts. Perigonadal fat of PpargC/- mice in the basal state showed dramatic decreases in adipose tissue mass and insulin sensitivity, whereas inguinal fat showed compensatory increases. Preservation of inguinal fat metabolic ability and flexibility was reflected by the normal expression of metabolic genes in the basal or fasting/refeeding states. The high nutrient load further increased insulin sensitivity in inguinal fat, but the expression of metabolic genes became dysregulated. Inguinal fat removal resulted in further impairment of whole-body insulin sensitivity in PpargC/- mice. Conversely, the compensatory increase in insulin sensitivity of the inguinal fat in PpargC/- mice diminished as activation of PPARγ by its agonists restored insulin sensitivity and metabolic ability of perigonadal fat. Together, we demonstrated that inguinal fat of PpargC/- mice plays a compensatory role in combating perigonadal fat abnormalities.


Asunto(s)
Resistencia a la Insulina , Lipodistrofia Parcial Familiar , PPAR gamma , Animales , Humanos , Ratones , Insulina/metabolismo , Insulina/farmacología , Resistencia a la Insulina/genética , Lipodistrofia Parcial Familiar/genética , Mutación , PPAR gamma/genética , PPAR gamma/metabolismo
12.
Int J Mol Sci ; 23(21)2022 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-36362259

RESUMEN

Human pluripotent stem cell (hPSC)-derived motor neurons (MNs) act as models for motor neuron diseases (MNDs), such as amyotrophic lateral sclerosis (ALS) or spinal muscular atrophy. However, the MN differentiation efficiency and viability following cryopreservation require further development for application in large-scale studies and drug screening. Here, we developed a robust protocol to convert hPSCs into MN cryopreservation stocks (hPSCs were converted into >92% motor neural progenitors and >91% MNs). Near-mature MNs were cryopreserved at a high thawing survival rate and 89% MN marker expression on day 32. Moreover, these MNs exhibited classical electrophysiological properties and neuromuscular junction (NMJ) formation ability within only 4−6 days after thawing. To apply this platform as an MND model, MN stocks were generated from SOD1G85R, SOD1G85G isogenic control, and sporadic ALS hPSC lines. The thawed ALS MNs expressed ALS-specific cytopathies, including SOD1 protein aggregation and TDP-43 redistribution. Thus, a stable and robust protocol was developed to generate ready-to-use cryopreserved MNs without further neuronal maturation processes for application in MND mechanistic studies, NMJ model establishment, and large-scale drug screening.


Asunto(s)
Esclerosis Amiotrófica Lateral , Células Madre Pluripotentes Inducidas , Células Madre Pluripotentes , Humanos , Esclerosis Amiotrófica Lateral/metabolismo , Superóxido Dismutasa-1/metabolismo , Neuronas Motoras/metabolismo , Células Madre Pluripotentes/metabolismo , Criopreservación
13.
Molecules ; 27(19)2022 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-36235203

RESUMEN

Glioblastoma multiforme (GBM) is the most common and malignant brain tumor. Temozolomide (TMZ) is the first-line chemotherapeutic drug for treating GBM. However, drug resistance is still a challenging issue in GBM therapy. Our preliminary results showed upregulation of androgen receptor (AR) gene expression in human GBM tissues. This study was designed to evaluate the effects of enzalutamide, a specific inhibitor of the AR, on killing drug-resistant and -sensitive glioblastoma cells and the possible mechanisms. Data mining from The Cancer Genome Atlas (TCGA) database revealed upregulation of AR messenger (m)RNA and protein expressions in human GBM tissues, especially in male patients, compared to normal human brains. In addition, expressions of AR mRNA and protein in human TMZ-sensitive U87 MG and -resistant U87 MG-R glioblastoma cells were elevated compared to normal human astrocytes. Exposure of human U87 MG and U87 MG-R cells to enzalutamide concentration- and time-dependently decreased cell viability. As to the mechanism, enzalutamide killed these two types of glioblastoma cells via an apoptotic mechanism. Specifically, exposure to enzalutamide augmented enzyme activities of caspase-9 rather than those of caspase-8. Moreover, enzalutamide successively triggered an elevation in levels of the proapoptotic Bax protein, a reduction in the mitochondrial membrane potential, release of cytochrome c, cascade activation of caspases-3 and -6, DNA fragmentation, and cell apoptosis in human TMZ-sensitive and -resistant glioblastoma cells. Pretreatment with Z-VEID-FMK, an inhibitor of caspase-6, caused significant attenuations in enzalutamide-induced morphological shrinkage, DNA damage, and apoptotic death. Taken together, this study showed that enzalutamide could significantly induce apoptotic insults to human drug-resistant and -sensitive glioblastoma cells via an intrinsic Bax-mitochondrion-cytochrome c-caspase cascade activation pathway. Enzalutamide has the potential to be a drug candidate for treating GBM by targeting the AR signaling axis.


Asunto(s)
Neoplasias Encefálicas , Glioblastoma , Apoptosis , Benzamidas , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/metabolismo , Caspasa 6/metabolismo , Caspasa 6/farmacología , Caspasa 8/metabolismo , Caspasa 9/metabolismo , Línea Celular Tumoral , Citocromos c/metabolismo , Glioblastoma/metabolismo , Humanos , Masculino , Mitocondrias/metabolismo , Nitrilos , Feniltiohidantoína , ARN/metabolismo , ARN Mensajero/metabolismo , Receptores Androgénicos/metabolismo , Temozolomida/farmacología , Proteína X Asociada a bcl-2/metabolismo
14.
Virus Genes ; 57(4): 380-384, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34037953

RESUMEN

The present study describes two full-genome sequences of Felis catus papillomavirus type 4 (FcaPV4) identified in squamous cell carcinoma (SCC) of two domestic cats. Two full-genome sequences of FcaPV4 were detected and characterized by PCR and sequencing. The L1 nucleotide sequence homology of one case showed 95.70% sequence identity to the reference FcaPV4, suggesting that this isolate should be classified as a subtype. Reverse-transcriptase PCR (RT-PCR) of two oncogenes, E6 and E7 was performed to confirm mRNA expression. Expression of E6 and E7 mRNA was detected in both cases, suggesting that FcaPV4 contributes to the development of SCC. This is the first report of FcaPV4 subtype. The present study will update the genomic features of FcaPV4 and contribute to deepening our knowledge about the etiological roles of FcaPV4 in feline cutaneous SCC.


Asunto(s)
Carcinoma de Células Escamosas/genética , Genoma Viral/genética , Papillomaviridae/genética , Neoplasias Cutáneas/genética , Animales , Carcinoma de Células Escamosas/veterinaria , Carcinoma de Células Escamosas/virología , Enfermedades de los Gatos/genética , Enfermedades de los Gatos/virología , Gatos , Regulación Viral de la Expresión Génica/genética , Humanos , Papillomaviridae/patogenicidad , Infecciones por Papillomavirus/genética , Infecciones por Papillomavirus/veterinaria , Infecciones por Papillomavirus/virología , Neoplasias Cutáneas/veterinaria , Neoplasias Cutáneas/virología
15.
Molecules ; 25(8)2020 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-32344649

RESUMEN

Neurodegenerative diseases represent a significant unmet medical need in our aging society. There are no effective treatments for most of these diseases, and we know comparatively little regarding pathogenic mechanisms. Among the challenges faced by those involved in developing therapeutic drugs for neurodegenerative diseases, the syndromes are often complex, and small animal models do not fully recapitulate the unique features of the human nervous system. Human induced pluripotent stem cells (iPSCs) are a novel technology that ideally would permit us to generate neuronal cells from individual patients, thereby eliminating the problem of species-specificity inherent when using animal models. Specific phenotypes of iPSC-derived cells may permit researchers to identify sub-types and to distinguish among unique clusters and groups. Recently, iPSCs were used for drug screening and testing for neurologic disorders including Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), spinocerebellar atrophy (SCA), and Zika virus infection. However, there remain many challenges still ahead, including how one might effectively recapitulate sporadic disease phenotypes and the selection of ideal phenotypes and for large-scale drug screening. Fortunately, quite a few novel strategies have been developed that might be combined with an iPSC-based model to solve these challenges, including organoid technology, single-cell RNA sequencing, genome editing, and deep learning artificial intelligence. Here, we will review current applications and potential future directions for iPSC-based neurodegenerative disease models for critical drug screening.


Asunto(s)
Descubrimiento de Drogas , Evaluación Preclínica de Medicamentos , Células Madre Pluripotentes Inducidas/efectos de los fármacos , Células Madre Pluripotentes Inducidas/metabolismo , Animales , Diferenciación Celular , Susceptibilidad a Enfermedades , Descubrimiento de Drogas/métodos , Evaluación Preclínica de Medicamentos/métodos , Humanos , Células Madre Pluripotentes Inducidas/citología , Enfermedades Neurodegenerativas/tratamiento farmacológico , Enfermedades Neurodegenerativas/etiología , Enfermedades Neurodegenerativas/metabolismo , Neuroglía/efectos de los fármacos , Neuroglía/metabolismo , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Fenotipo
16.
Genesis ; 57(9): e23309, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31162816

RESUMEN

The placement of eyes on insect head is an important evolutionary trait. The stalk-eyed fly, Cyrtodopsis whitei, exhibits a hypercephaly phenotype where compound eyes are located on lateral extension from the head while the antennal segments are placed inwardly on this stalk. This stalk-eyed phenotype is characteristic of the family Diopsidae in the Diptera order and dramatically deviates from other dipterans, such as Drosophila. Like other insects, the adult eye and antenna of stalk-eyed fly develop from a complex eye-antennal imaginal disc. We analyzed the markers involved in proximo-distal (PD) axis of the developing eye imaginal disc of the stalk-eyed flies. We used homothorax (hth) and distalless (dll), two highly conserved genes as the marker for proximal and distal fate, respectively. We found that lateral extensions between eye and antennal field of the stalk-eyed fly's eye-antennal imaginal disc exhibit robust Hth expression. Hth marks the head specific fate in the eye- and proximal fate in the antenna-disc. Thus, the proximal fate marker Hth expression evolves in the stalk-eyed flies to generate lateral extensions for the placement of the eye on the head. Moreover, during pupal eye metamorphosis, the lateral extension folds back on itself to place the antenna inside and the adult compound eye on the distal tip. Interestingly, the compound eye in other insects does not have a prominent PD axis as observed in the stalk-eyed fly.


Asunto(s)
Ojo Compuesto de los Artrópodos/embriología , Dípteros/embriología , Genes de Insecto , Marcadores Genéticos , Animales , Dípteros/genética , Drosophila/genética , Inducción Embrionaria , Proteínas de Homeodominio/genética , Metamorfosis Biológica/genética , Retina/embriología
17.
BMC Vet Res ; 15(1): 421, 2019 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-31775769

RESUMEN

BACKGROUND: Since 2010, outbreaks of genotype 2 (G2) porcine epidemic diarrhea virus (PEDV) have caused high mortality in neonatal piglets and have had devastating impacts on the swine industry in many countries. A reliable serological assay for evaluating the PEDV-specific humoral and mucosal immune response is important for disease survey, monitoring the efficacy of immunization, and designing strategies for the prevention and control of PED. Two PEDV spike (S) glycoprotein-based indirect enzyme-linked immunosorbent assays (ELISAs) were developed using G2b PEDV-Pintung 52 (PEDV-PT) trimeric full-length S and truncated S1-501 proteins derived from the human embryonic kidney (HEK)-293 cell expression system. The truncated S1-501 protein was selected from a superior expressed stable cell line. The sensitivity and specificity of these two ELISAs were compared to immunostaining of G2b PEDV-PT infected cells and to a commercial nucleocapsid (N)-based indirect ELISA kit using a panel of PEDV negative and hyperimmune sera. RESULTS: The commercial N-based ELISA exhibited a sensitivity of 37%, a specificity of 100%, and a fair agreement (kappa = 0.37) with the immunostaining result. In comparison, the full-length S-based ELISA showed a sensitivity of 97.8%, a specificity of 94%, and an almost perfect agreement (kappa = 0.90) with the immunostaining result. Interestingly, the S1-501-based ELISA had even higher sensitivity of 98.9% and specificity of 99.1%, and an almost perfect agreement (kappa = 0.97) with the immunostaining result. A fair agreement (kappa< 0.4) was seen between the commercial N-based ELISA and either of our S-based ELISAs. However, the results of the full-length S-based ELISA shared an almost perfect agreement (kappa = 0.92) with that of S1-501-based ELISA. CONCLUSIONS: Both full-length S-based and S1-501-based ELISAs exhibit high sensitivity and high specificity for detecting antibodies against PEDVs. Considering the high protein yield and cost-effectiveness, the S1-501-based ELISA could be used as a reliable, sensitive, specific, and economic serological test for PEDV.


Asunto(s)
Infecciones por Coronavirus/veterinaria , Ensayo de Inmunoadsorción Enzimática/veterinaria , Virus de la Diarrea Epidémica Porcina/inmunología , Enfermedades de los Porcinos/virología , Animales , Anticuerpos Antivirales/sangre , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/inmunología , Ensayo de Inmunoadsorción Enzimática/métodos , Sensibilidad y Especificidad , Glicoproteína de la Espiga del Coronavirus/inmunología , Porcinos , Enfermedades de los Porcinos/diagnóstico , Enfermedades de los Porcinos/inmunología
18.
Plant Cell Rep ; 38(8): 899-914, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31004187

RESUMEN

KEY MESSAGE: A 146-bp sugar response complex MTSRC is identified in the promoter of rice metallothionein OsMT2b gene conferring high-level expression of luciferase reporter gene and bioactive recombinant haFGF in transgenic rice. A rice subfamily type 2 plant metallothionein (pMT) gene, OsMT2b, encoding a reactive oxygen species (ROS) scavenger protein, has been previously shown to exhibit the most abundant gene expression in young rice seedling. Expression of OsMT2b was found to be regulated negatively by ethylene and hydrogen peroxide in rice stem node under flooding stress, but little is known about its response to sugar depletion. In this study, transient expression assay and transgenic approach were employed to characterize the regulation of the OsMT2b gene expression in rice. We found that the expression of OsMT2b gene is induced by sugar starvation in both rice suspension cells and germinated embryos. Deletion analysis and functional assay of the OsMT2b promoter revealed that the 5'-flanking region of the OsMT2b between nucleotides - 351 and - 121, which contains the sugar response complex (- 266 to - 121, designated MTSRC) is responsible for high-level promoter activity under sugar starvation. It was also found that MTSRC significantly enhances the Act1 promoter activity in transgenic rice cells and seedlings. The modified Act1 promoter, Act1-MTSRC, was used to produce the recombinant human acidic fibroblast growth factor (haFGF) in rice cells. Our result shows that the bioactive recombinant haFGF is stably produced in transformed rice cell culture and yields are up to 2% of total medium proteins. Our studies reveal that MTSRC serves as a strong transcriptional activator and the Act1-MTSRC promoter can be applicable in establishing an efficient expression system for the high-level production of foreign proteins in transgenic rice cells and seedlings.


Asunto(s)
Metalotioneína/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Regulación de la Expresión Génica de las Plantas/fisiología , Germinación/genética , Germinación/fisiología , Metalotioneína/genética , Oryza/genética , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Regiones Promotoras Genéticas/genética , Especies Reactivas de Oxígeno/metabolismo , Plantones/genética , Plantones/metabolismo , Azúcares/metabolismo
19.
Nanotechnology ; 29(50): 505202, 2018 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-30256765

RESUMEN

This study demonstrates dual functional hybrid heterojunction photodiodes (PDs) that comprise an amorphous indium gallium zinc oxide (a-IGZO) thin film blended with graphene nanoflakes and a SiO2 (5 nm)/Si substrate. The PDs exhibit a photo-responsivity of approximately 0.15-0.27 A W-1 under 633 nm illumination, which is much higher than that for a-IGZO based phototransistor in the visible region. The device also gives a long-lasting persistent photocurrent (PPC) when the UV light is extinguished. This results show that the hybrid heterojunction acts as a high performance photodetector for the detection of visible light and provides a universal scenario for development of PPC.

20.
Appl Microbiol Biotechnol ; 102(17): 7499-7507, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29961099

RESUMEN

Devastating outbreaks of porcine epidemic diarrhea (PED) started in China in late 2010 and rapidly spread to North America and Asia causing severe diarrhea and high mortality in neonatal piglets, indicating that a new generation of vaccine against porcine epidemic diarrhea virus (PEDV) is urgently needed. In the present study, to mimic the native spike (S) glycoprotein, a stable cell line producing the trimeric ectodomain of S glycoprotein of the PEDV Pintung-52 (PEDV-PT) strain was successfully established by incorporating T4 bacteriophage foldon sequence of fibritin trimerization domains at the C-terminal end and replacing the signal peptide of S protein with the tissue plasminogen activator signal peptide sequence at the N terminal end. The trimeric structure, bio-reactivity to PEDV-specific antibodies, and the N-glycosylation level of the recombinant S protein were characterized. To induce systemic and mucosal immunity, conventional 5-week-old piglets were immunized with the trimeric S glycoprotein combined with the B subunit of Escherichia coli heat-labile enterotoxin (LTB) by the intramuscular (IM) route. As compared with the control group, all piglets in the S protein-LTB immunized (IM PEDV S-LTB) group generated systemic PEDV S-specific IgG and neutralizing antibody in blood but a low level of fecal PEDV-specific IgA and limited protection against challenge of PEDV-PT strain. Our results suggest that the recombinant PEDV trimeric S glycoprotein could be a potential subunit vaccine candidate against PEDV, but IM immunization with LTB as the adjuvant provided insufficient protection. The development of a vaccine regimen for inducing mucosal immunity is an important task for generating a successful subunit vaccine against PEDVs.


Asunto(s)
Virus de la Diarrea Epidémica Porcina/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Vacunas Virales/inmunología , Adyuvantes Inmunológicos/administración & dosificación , Animales , Anticuerpos Antivirales/sangre , Línea Celular , Enterotoxinas/inmunología , Calor , Porcinos , Activador de Tejido Plasminógeno/genética , Activador de Tejido Plasminógeno/inmunología , Vacunas de Subunidad/administración & dosificación , Vacunas de Subunidad/inmunología , Vacunas Virales/administración & dosificación
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA