RESUMEN
The phospholipase C (PLC) is a family of kinases that hydrolyze phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] to generate two second messengers, inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG), which stimulate distinct downstream signaling. Recently, it has been reported that PLC signaling is activated by multiple viruses for efficient replication and the virus-induced inflammatory response. In this study, we demonstrated that PLC-specific inhibitor U73122 strongly suppressed porcine reproductive and respiratory syndrome virus (PRRSV) productive infection in cell cultures. The inhibitor affected both viral post-binding cell entry and post-entry processes. The virus infection led to an early transient activation of PLCγ-1 at 0.5 h post-infection (hpi), and sustained event at a stage from 4 to 16 hpi in MARC-145 cells. In addition, U73122 inhibited the activation of p38 MAPK signaling stimulated by PRRSV infection, suggesting that PLC signaling may be associated with the virus infection-induced inflammatory response. Taken together, these studies suggested that PLC signaling played an important role in PRRSV infection or pathogenesis. Keywords: PRRSV; U73122; phospholipase C; PLCγ-1.
Asunto(s)
Síndrome Respiratorio y de la Reproducción Porcina , Virus del Síndrome Respiratorio y Reproductivo Porcino , Fosfolipasas de Tipo C , Animales , Línea Celular , Estrenos/farmacología , Inhibidores de Fosfodiesterasa/farmacología , Síndrome Respiratorio y de la Reproducción Porcina/fisiopatología , Pirrolidinonas/farmacología , Transducción de Señal , Porcinos , Fosfolipasas de Tipo C/antagonistas & inhibidores , Fosfolipasas de Tipo C/fisiología , Internalización del Virus/efectos de los fármacosRESUMEN
OBJECTIVE: Desmoglein-2 (Dsg2) plays a crucial role in the assembly and adhesion of desmosomes. The absent or aberrant expression of Dsg2 was reported to be associated with the progression of varies human cancers. However, the expression of Dsg2 in hepatocellular carcinoma (HCC) and its association with tumor prognosis is still unknown. The aim of this study was to evaluate the expression level of Dsg2 in HCC and of the correlation between Dsg2 expression and clinicopathological variables. PATIENTS AND METHODS: A total of 104 patients diagnosed with HCC were enrolled in this study. Real time-quantitative PCR (RT-qPCR) and Western blot were performed to determine the expression level of Dsg2 in HCC tumor tissues and matched noncancerous tissues. Cell proliferation and cell cycle were measured by cell counting kit-8 (CCK-8) assay and flow-cytometry assay, respectively. RESULTS: Our results revealed that Dsg2 expression was significantly higher in HCC tumor tissues than in matched noncancerous tissues (p < 0.01), positively correlated with tumor size (p = 0.035) and tumor stage (p = 0.021). Univariate and multivariate analyses demonstrated Dsg2 expression was an independent prognostic factor for overall survival. Meanwhile, we found knockdown the expression of Dsg2 using small interfering RNA (siRNA) could efficiently impaired HCC cell proliferation rate and cell cycle progression (p < 0.05). CONCLUSIONS: Taken together, our results suggest that increased Dsg2 expression was associated with tumor progression in HCC and may function as a promising biomarker for unfavorable prognosis of HCC.
Asunto(s)
Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/metabolismo , Desmogleína 2/biosíntesis , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/metabolismo , Adulto , Biomarcadores de Tumor/biosíntesis , Biomarcadores de Tumor/genética , Carcinoma Hepatocelular/genética , Línea Celular Tumoral , Proliferación Celular/genética , Desmogleína 2/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Hepáticas/genética , Masculino , Persona de Mediana Edad , PronósticoRESUMEN
Environmental indicators are powerful tools for tracking environmental changes, measuring environmental performance, and informing policymakers. Many diverse environmental indicators, including agricultural environmental indicators, are currently in use or being developed. This special collection of technical papers expands on the peer-reviewed literature on environmental indicators and their application to important current issues in the following areas: (i) model-derived indicators to indicate phosphorus losses from arable land to surface runoff and subsurface drainage, (ii) glutathione-ascorbate cycle-related antioxidants as early-warning bioindicators of polybrominated diphenyl ether toxicity in mangroves, and (iii) assessing the effectiveness of using organic matrix biobeds to limit herbicide dissipation from agricultural fields, thereby controlling on-farm point-source pollution. This introductory review also provides an overview of environmental indicators, mainly for agriculture, with examples related to the quality of the agricultural soil-water-air continuum and the application of model-derived indicators. Current knowledge gaps and future lines of investigation are also discussed. It appears that environmental indicators, particularly those for agriculture, work efficiently at the field, catchment, and local scales and serve as valuable metrics of system functioning and response; however, these indicators need to be refined or further developed to comprehensively meet community expectations in terms of providing a consistent picture of relevant issues and/or allowing comparisons to be made nationally or internationally.
Asunto(s)
Agricultura , Contaminantes Ambientales/análisis , Contaminación del Aire , Monitoreo del Ambiente , Herbicidas , Fósforo , Suelo , AguaRESUMEN
Objective: To explore the mechanism of Yes-associated protein 1 (Yap1) in angiotensinâ ¡(Angâ ¡)-induced pulmonary fibrosis. Methods:In vivo, 18 male Wistar rats were randomly divided into three equal groups with 6 rats in each group, including control group, bleomycin-treated group (BLM), and BLM+ Angâ ¡ group. 28 days later, the lung tissues in all groups were harvested for the HE and Masson staining as well as the immunohistochemical (IHC) staining for Yap1. In vitro, the isolated fibroblasts were treated with 10(-7) mmol/L Angâ ¡or the Angâ ¡-targeted inhibitor irbesartan for the scheduled time for mRNA and protein expressions of Yap1, PDZ-binding motif (TAZ), and collagen â using PCR and Western blot, as well as the translocation test from the nucleus to the cytoplasm of Yap1 and TAZ. Subsequently, the fibroblasts were assigned into 4 groups: the empty plasmid (vector) group, the vector+ Angâ ¡ group, the Yap1 shRNA group, and the Yap1 shRNA+ Angâ ¡ group. Western blot was used to detect the relative expressions of Yap1, TAZ, Smad3 and collagen â . The CCK-8 and EdU assays were performed to determine the proliferative capacity. Results:In vivo, severe lung fibrosis and increased Yap1 expression of IHC staining were found in BLM group. Additionally, more severe lung fibrosis and higher Yap1 expression were detected in the BLM+ Angâ ¡ group than the BLM group (both P<0.05). In vitro, both the mRNA and protein relative expressions of Yap1, TAZ and collagenâ were markedly higher in Angâ ¡-treated groups than the control group (all P<0.05). Meanwhile, the relative expression of phosphorylated Yap1 reached its peak at 2 h after Angâ ¡ stimulation. In the protein translocation tests, after treated with Angâ ¡ for 24 h, the relative protein levels of Yap1 and TAZ in the nucleus of the Angâ ¡ group were significantly higher than those in the control group (0.382±0.007 vs 0.031±0.001, 1.097±0.030 vs 0.357±0.015). However, the relative protein expressions in the cytoplasm of the Angâ ¡ group were obviously less than that in the control group (0.323±0.058 vs 0.418±0.044, 0.858±0.059 vs 1.201±0.015). Compared with the Angâ ¡ group, the expressions of Yap1 and TAZ in the Angâ ¡+ irbesartan group were higher in cytoplasm (0.598±0.060 vs 0.323±0.058, 1.495±0.052 vs 0.858±0.059), while lower in the nucleus (0.323±0.058 vs 0.418±0.044, 0.858±0.059 vs 1.201±0.015) (all P<0.05). Furthermore, the relative protein expressions of Yap1, TAZ, Smad3 and collagenâ in Yap1 shRNA+ Angâ ¡ group were distinctly lower than the vector+ Angâ ¡ group (all P<0.05). In the cell proliferation tests, the absorbance and the percentage of EdU positive cells of vector+ Angâ ¡ group exceeded that of vector group (both P<0.05). However, the absorbance and the percentage of EdU positive cells in the Yap1 shRNA+ Angâ ¡group were less than the vector+ Angâ ¡ group (both P<0.05). Conclusion: Angiotensinâ ¡ promoted the collagen synthesis and cell proliferation in primary lung fibroblasts by increasing the Yap1 activity, leading to the progress of fibrosis.
Asunto(s)
Fibrosis Pulmonar , Proteínas Adaptadoras Transductoras de Señales , Angiotensina II , Animales , Bleomicina , Colágeno Tipo I , Pulmón , Masculino , Proteínas Nucleares , Ratas , Ratas WistarRESUMEN
Objective: To explore the mechanism of angiotensin-converting enzyme 2 (ACE2) overexpression improving collagen synthesis in lung. Methods: Lung fibroblasts of mice over-expressing ACE2 and the wild type (WT) were cultured in vitro and divided into 5 groups: WT-control, WT-Angiotensinâ ¡ (Angâ ¡), ACE2(+ /+) -control, ACE2(+ /+) -Angâ ¡ and ACE2(+ /+) -Angâ ¡+ A779. The protein relative expression levels of ACE2, collagen â , nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4), nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3), autophagy-related protein (Beclin1), ubiquitin-binding protein p62 (P62), microtubule-associated proteins light chain 3-â ¡ (LC3-â ¡) were measured by Western blot and triphosadenine (ATP) level was measured by ATP Assay Kit. Fibroblasts over-expressing ACE2 were pretreated with or without the autophagy inhibitor and were separated into 4 groups: ACE2(+ /+) -control, ACE2(+ /+) -Angâ ¡, ACE2(+ /+) -Angâ ¡+ 3-MA and ACE2(+ /+) -3-MA. In vivo, random allocation was used to averagely divide mice into four groups: WT-control, WT-Bleomycin (BLM), ACE2(+ /+) - control, ACE2(+ /+) -BLM. Wild type and ACE2 over-expressing mice were instilled with bleomycin endotracheally (3.5 mg/kg) or the same volume saline. All mice were sacrificed after 28 days and the lung tissue were used for HE and Masson staining as well as immunohistochemical staining for NOX4, P62 and LC3. Results: The vimentin in lung fibroblasts isolated from mice was proved to be positive by both immunohistochemical and immunofluorescence. The ACE2 protein level of lung fibroblasts over-expressing ACE2 was higher than the wild type (0.202±0.062 and 0.067±0.040, P<0.05). The protein levels of collagenâ , NOX4 and NLRP3 in WT-Angâ ¡ group were obviously higher than the WT-control group (0.861±0.129 and 0.417±0.076, 0.432±0.036 and 0.318±0.058, 0.367±0.125 and 0.045±0.012, all P<0.05). The difference of collagenâ and NLRP3 between ACE2(+ /+) -Angâ ¡ group and ACE2(+ /+) -control group had no statistical significance (all P>0.05). Collagenâ and NOX4 protein level in ACE2(+ /+) -Angâ ¡+ A779 group were observably higher than ACE2(+ /+) - Angâ ¡ group (0.707±0.155 and 0.458±0.108, 0.299±0.038 and 0.149±0.090, all P<0.05). The autophagy related protein levels of Beclin1, P62 and LC3-â ¡ in ACE2(+ /+) -control group were distinctly higher than WT-control group (0.834±0.051 and 0.274±0.018, 0.467±0.078 and 0.093±0.025, 0.494±0.065 and 0.150±0.054, all P<0.05). However, these protein levels in ACE2(+ /+) -Angâ ¡+ A779 group were lower than ACE2(+ /+) -Angâ ¡ group (1.331±0.203 and 1.565±0.069, 0.298±0.096 and 0.438±0.077, 0.464±0.093 and 0.768±0.071, all P<0.05). ACE2(+ /+) -Angâ ¡+ 3-MA group had higher collagenâ (0.383±0.125 and 0.032±0.013, P<0.05) and lower LC3-â ¡ protein level (1.177±0.140 and 1.387±0.183, P<0.05) than Angâ ¡ group. In bleomycin induced lung fibrosis in mice, ACE2(+ /+) -BLM mice exhibited milder lung fibrosis and lower NOX4 protein level but higher LC3-â ¡protein level compared with WT-BLM mice. Conclusion: ACE2 over-expression ameliorated collagen synthesis through enhancing autophagy in lung.
Asunto(s)
Pulmón , Angiotensina II , Enzima Convertidora de Angiotensina 2 , Animales , Bleomicina , Western Blotting , Colágeno Tipo I , Fibroblastos , Masculino , Ratones , Proteína con Dominio Pirina 3 de la Familia NLR , Fragmentos de Péptidos , Peptidil-Dipeptidasa A , Fibrosis Pulmonar , Transducción de SeñalRESUMEN
Integrating multiple practices for mitigation of phosphorus (P) loss from soils may enhance the reduction efficiency, but this has not been studied as much as individual ones. A four-year study was conducted to determine the effects of cover crop (CC) (CC vs. no CC, NCC) and drainage water management (DWM) (controlled drainage with sub-irrigation, CDS, vs. regular free tile drainage, RFD) and their interaction on P loss through both surface runoff (SR) and tile drainage (TD) water in a clay loam soil of the Lake Erie region. Cover crop reduced SR flow volume by 32% relative to NCC, regardless of DWM treatment. In contrast, CC increased TD flow volume by 57 and 9.4% with CDS and RFD, respectively, compared to the corresponding DWM treatment with NCC. The total (SR+TD) field water discharge volumes were comparable amongst all the treatments. Cover crop reduced flow-weighted mean (FWM) concentrations of particulate P (PP) by 26% and total P (TP) by 12% in SR, while it didn't affect the FWM dissolved reactive P (DRP) concentration, regardless of DWM treatments. Compared with RFD, CDS reduced FWM DRP concentration in TD water by 19%, while CC reduced FWM PP and TP concentrations in TD by 21 and 17%, respectively. Total (SR+TD) soil TP loss was the least with CDS-CC followed by RFD-CC, CDS-NCC, and RFD-NCC. Compared with RFD-NCC, currently popular practice in the region, total TP loss was reduced by 23% with CDS-CC. The CDS-CC system can be an effective practice to ultimately mitigate soil P loading to water resource.
RESUMEN
The research history of the genus Apalacris is reviewed; a key to all known species of the genus is given, and one new species, Apalacris eminifronta n. sp., and one new combination, Apalacris maculifemura (Lin & Zheng), are described. The new species is very closely related to Apalacris antennata Liang, but differs in the following characters: (1) tegmen longer, reaching apex of hind femur; (2) basal part of inner side of hind femur orange red; (3) frontal ridge more protruded, obviously depressed under median ocellus in lateral view; and (4) epiphallus bridge prominent, ancora shorter than anterior projection.
Asunto(s)
Saltamontes/clasificación , AnimalesRESUMEN
Phosphorus applied to soils in excess of crop requirement could create situations favorable to P enrichment in subsurface flow that contributes to eutrophication of surface water. This pathway of P loss can be more severe in muck (i.e., organic) soils where agricultural production is intensive. This study evaluated the suitability of various environmental and agronomic soil P tests initially designed for mineral soils to predict dissolved reactive P (DRP) in subsurface flow from organic soils. Intact soil columns were collected from 44 muck soils in Ontario to provide a wide range of soil test P levels. A lysimeter leaching study was conducted by evenly adding water in an amount equivalent to 5 mm of rainfall. The leachate DRP concentration was linearly related to soil water-extractable P and CaCl-extractable P with values of 0.90 and 0.93, respectively, and to Bray-1 P and FeO-impregnated filter paper extractable P in a split-line model with a change point. Mehlich-3 P and Olsen P, a method recommended for agronomic P calibration in Ontario, were not related to leachate DRP concentration. All P sorption index (PSI) based degree of P saturation (DPS) values were closely related to leachate DRP in split-line models, with the DPS indices expressed as Bray-1 P/PSI and FeO-P/PSI having the highest correlation with leachate DRP concentration. Because it is desirable from practical and economic standpoints that the environmental risk assessment shares the same soil test with agronomic P calibration, the two PSI-based DPS indices as presented can be considered as environmental risk indicators of DRP subsurface loss from organic soils.
RESUMEN
Two new species of the tetrigid genus Criotettix Bolivar from China, namely Criotettix interruptaoides Deng & Zheng n. sp. and Criotettix shiwanshanensis Deng & Zheng n. sp. are described. An updated key to all known species of the genus from China is given.
Asunto(s)
Ortópteros/clasificación , Animales , ChinaRESUMEN
Adoption of waste-derived soil conditioners and refined water management can improve soil physical quality and crop productivity of fine-textured soils. However, the impacts of these practices on water quality must be assessed to ensure environmental sustainability. We conducted a study to determine phosphorus (P) loss in tile drainage as affected by two types of soil conditioners (yard waste compost and swine manure compost) and water table management (free drainage and controlled drainage with subirrigation) in a clay loam soil under corn-soybean rotation in a 4-yr period from 1999 to 2003. Tile drainage flows were monitored and sampled on a year-round continuous basis using on-site auto-sampling systems. Water samples were analyzed for dissolved reactive P (DRP), particulate P (PP), and total P (TP). Substantially greater concentrations and losses of DRP, PP, and TP occurred with swine manure compost than with control and yard waste compost regardless of water table management. Compared with free drainage, controlled drainage with subirrigation was an effective way to reduce annual and cumulative losses of DRP, PP, and TP in tile drainage through reductions in flow volume and P concentration with control and yard waste compost but not with swine manure compost. Both DRP and TP concentrations in tile drainage were well above the water quality guideline for P, affirming that subsurface loss of P from fine-textured soils can be one critical source for freshwater eutrophication. Swine manure compost applied as a soil conditioner must be optimized by taking water quality impacts into consideration.
RESUMEN
Phosphorus (P) loss in tile drainage water may vary with agricultural practices, and the impacts are often hard to detect with short-term studies. We evaluated the effects of long-term (≥43 yr) cropping systems (continuous corn [CC], corn-oats-alfalfa-alfalfa rotation [CR], and continuous grass [CS]) and fertilization (fertilization [F] vs. no-fertilization [NF]) on P loss in tile drainage water from a clay loam soil over a 4-yr period. Compared with NF, long-term fertilization increased concentrations and losses of dissolved reactive P (DRP), dissolved unreactive P (DURP), and total P (TP) in tile drainage water, with the increments following the order: CS > CR > CC. Dissolved P (dissolved reactive P [DRP] and dissolved unreactive P [DURP]) was the dominant P form in drainage outflow, accounting for 72% of TP loss under F-CS, whereas particulate P (PP) was the major form of TP loss under F-CC (72%), F-CR (62%), NF-CS (66%), NF-CC (74%), and NF-CR (72%). Dissolved unreactive P played nearly equal roles as DRP in P losses in tile drainage water. Stepwise regression analysis showed that the concentration of P (DRP, DURP, and PP) in tile drainage flow, rather than event flow volume, was the most important factor contributing to P loss in tile drainage water, although event flow volume was more important in PP loss than in dissolved P loss. Continuous grass significantly increased P loss by increasing P concentration and flow volume of tile drainage water, especially under the fertilization treatment. Long-term grasslands may become a significant P source in tile-drained systems when they receive regular P addition.
RESUMEN
OBJECTIVE: The common clinical techniques used for examining thyroid tumors include palpation, imaging, immunoassays and tissue biopsy. Ultrasonography is easy, non-invasive, non-radioactive and highly reproducible imaging technique; however, due to the disease polytropism, diagnosis may become difficult sometimes. Ultrasound elastography, particularly acoustic radiation force impulse (ARFI) imaging and contrast-enhanced ultrasonography (CEUS) have been successfully used to diagnose the thyroid tumors. The objective of this retrospective study was to analyze and compare the solid thyroid nodules imaged by high-frequency ultrasonography (HFUS), ARFI imaging, and CEUS. PATIENTS AND METHODS: For this purpose, images of the 80 solid thyroid nodules (58 benign and 22 malignant) with surgical pathology were obtained and data were compared using binary logistic regression analysis. RESULTS: Morphology (p < 0.001), and internal calcification (p = 0.007) were statistically different. The mean shear wave velocity (SWV) measured by ARFI was significantly different (p = 0.029). Three sets of comparison on CEUS (p = 0.019) and time to peak (TTP) of CEUS were significantly different (p = 0.001). The logistic regression analysis indicated that the morphology, mean SWV of ARFI and TTP were independent risk factors for malignancy. The diagnostic accuracy for solid thyroid nodules was 85.1% (68/80) and the area under the receiver operating characteristic (ROC) curve was 0.945±0.033. CONCLUSIONS: Logistic regression analysis can effectively screen significant parameters for the differential diagnosis of solid thyroid nodules imaged by ultrasonography.
Asunto(s)
Medios de Contraste , Diagnóstico por Imagen de Elasticidad/métodos , Neoplasias de la Tiroides/diagnóstico por imagen , Nódulo Tiroideo/diagnóstico por imagen , Adulto , Diagnóstico Diferencial , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Adulto JovenRESUMEN
Diabetic neuropathy is a common complication of diabetes. It occurs in approximately 10-20% of patients with diabetes, or roughly 40-50% patients with diabetic neuropathy. However, the pathogenesis of diabetic neuropathic pain is still largely unknown. Several animal models have been used to study the underlying mechanisms for this complication. Some commonly used animal models include streptozotocin-induced rat and mouse models, diet/nutrition-induced models, combination of chemically- and nutrition-induced model, Zucker diabetic fatty rat model, type 1 insulinopenic BB/Wor and type 2 hyperinsulinemic diabetic BBZDR/Wor rat models, and transgenic/knock-out models. Even though the manifestations of diabetic neuropathic pain vary from thermal or chemical hyperalgesia, thermal or chemical hypoalgeia, allodynia, to spontaneous pain, some pathogenesis factors are shared among these symptoms. Increased AR activity, oxidative-nitrosative stress, protein kinase C, PARP and ACE activations, C-peptide deficiency, impaired neurotrophism, and proinflammatory responses have been identified in the development of diabetic neuropathic pain. This review discusses selected animal models for diabetic neuropathic pain, as well as some commonly shared pathways in these models.
Asunto(s)
Diabetes Mellitus Experimental , Neuropatías Diabéticas , Neuralgia , Animales , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patología , Neuropatías Diabéticas/genética , Neuropatías Diabéticas/metabolismo , Neuropatías Diabéticas/patología , Ratones , Ratones Noqueados , Neuralgia/genética , Neuralgia/metabolismo , Neuralgia/patología , Ratas , Ratas ZuckerRESUMEN
Two new species of the tetrigid genus Xistra Bolivar from China, namely Xistra oculata Li, Deng et Zheng n. sp. and Xistra brachynota Li, Deng et Zheng n. sp. are described. An updated key to all known species of the genus is given.
Asunto(s)
Ortópteros/clasificación , Animales , ChinaRESUMEN
The review of the genus Pielomastax is given. The genus consists of 14 species distributed in China. Pielomastax cladopygidium n. sp. is described from Shaanxi Province. An annotated list of species and key to species of Pielomastax is provided.
Asunto(s)
Ortópteros/clasificación , Animales , ChinaRESUMEN
Four new species of Tetrigidae (Orthoptera) from Anhui province, China, are described, namely Paragavialidium anhuiensis n. sp. of Scelimeninae, Bolivaritettix jinzhaiensis n. sp. of Metrodorinae, Bannatettix anhuiensis n. sp., and Formosatettix albomaculatus n. sp. of Tetriginae.
Asunto(s)
Ortópteros/clasificación , Animales , ChinaRESUMEN
Taxonomy of a tetrigid genus Formosatettixoides Zheng is reviewed. Two new species, Formosatettixoides nigellus n. sp. and Formosatettixoides dabieshanensis n. sp. are described. Redescription of the characters of the genus is given, the distribution and an updated key to the now 10 species of the genus are presented.
Asunto(s)
Ortópteros/clasificación , AnimalesRESUMEN
A new species, Macromotettixoides lativertex Deng et al n. sp. is described with detailed illustrations of external morphology. Comparison between the species M. lativertex n. sp. and allied species is compiled into a table for identification. The distribution and an updated identification key to all known species of the genus is given.
Asunto(s)
Ortópteros/clasificación , Animales , ChinaRESUMEN
The taxonomy of the tetrigid genus Alulatettix Liang is reviewed. A new species, Alulatettix orthomarginalis n. sp. is described. The annotated list and key to all known species of Alulatettix are given.
Asunto(s)
Ortópteros/anatomía & histología , Ortópteros/clasificación , Animales , Femenino , MasculinoRESUMEN
Most human pre-mRNA transcripts are alternatively spliced, but the significance and fine-tuning of alternative splicing in different biological processes is only starting to be understood. SRSF3 (SRp20) is a member of a highly conserved family of splicing factors that have critical roles in key biological processes, including tumor progression. Here, we show that SRSF3 regulates cellular senescence, a p53-mediated process to suppress tumorigenesis, through TP53 alternative splicing. Downregulation of SRSF3 was observed in normal human fibroblasts undergoing replicative senescence, and was associated with the upregulation of p53ß, an alternatively spliced isoform of p53 that promotes p53-mediated senescence. Knockdown of SRSF3 by short interfering RNA (siRNA) in early-passage fibroblasts induced senescence, which was associated with elevated expression of p53ß at mRNA and protein levels. Knockdown of p53 partially rescued SRSF3-knockdown-induced senescence, suggesting that SRSF3 acts on p53-mediated cellular senescence. RNA pulldown assays demonstrated that SRSF3 binds to an alternatively spliced exon uniquely included in p53ß mRNA through the consensus SRSF3-binding sequences. RNA crosslinking and immunoprecipitation assays (CLIP) also showed that SRSF3 in vivo binds to endogenous p53 pre-mRNA at the region containing the p53ß-unique exon. Splicing assays using a transfected TP53 minigene in combination with siRNA knockdown of SRSF3 showed that SRSF3 functions to inhibit the inclusion of the p53ß-unique exon in splicing of p53 pre-mRNA. These data suggest that downregulation of SRSF3 represents an endogenous mechanism for cellular senescence that directly regulates the TP53 alternative splicing to generate p53ß. This study uncovers the role for general splicing machinery in tumorigenesis, and suggests that SRSF3 is a direct regulator of p53.