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1.
Mol Cell ; 80(6): 1104-1122.e9, 2020 12 17.
Artículo en Inglés | MEDLINE | ID: mdl-33259812

RESUMEN

Human transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causative pathogen of the COVID-19 pandemic, exerts a massive health and socioeconomic crisis. The virus infects alveolar epithelial type 2 cells (AT2s), leading to lung injury and impaired gas exchange, but the mechanisms driving infection and pathology are unclear. We performed a quantitative phosphoproteomic survey of induced pluripotent stem cell-derived AT2s (iAT2s) infected with SARS-CoV-2 at air-liquid interface (ALI). Time course analysis revealed rapid remodeling of diverse host systems, including signaling, RNA processing, translation, metabolism, nuclear integrity, protein trafficking, and cytoskeletal-microtubule organization, leading to cell cycle arrest, genotoxic stress, and innate immunity. Comparison to analogous data from transformed cell lines revealed respiratory-specific processes hijacked by SARS-CoV-2, highlighting potential novel therapeutic avenues that were validated by a high hit rate in a targeted small molecule screen in our iAT2 ALI system.


Asunto(s)
Células Epiteliales Alveolares/metabolismo , COVID-19/metabolismo , Fosfoproteínas/metabolismo , Proteoma/metabolismo , SARS-CoV-2/metabolismo , Células Epiteliales Alveolares/patología , Células Epiteliales Alveolares/virología , Animales , Antivirales , COVID-19/genética , COVID-19/patología , Chlorocebus aethiops , Efecto Citopatogénico Viral , Citoesqueleto , Evaluación Preclínica de Medicamentos , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/patología , Células Madre Pluripotentes Inducidas/virología , Fosfoproteínas/genética , Transporte de Proteínas , Proteoma/genética , SARS-CoV-2/genética , Transducción de Señal , Células Vero , Tratamiento Farmacológico de COVID-19
3.
Nucleic Acids Res ; 50(2): 1033-1051, 2022 01 25.
Artículo en Inglés | MEDLINE | ID: mdl-34928368

RESUMEN

The production of ribosomes is an energy-intensive process owing to the intricacy of these massive macromolecular machines. Each human ribosome contains 80 ribosomal proteins and four non-coding RNAs. Accurate assembly requires precise regulation of protein and RNA subunits. In response to stress, the integrated stress response (ISR) rapidly inhibits global translation. How rRNA is coordinately regulated with the rapid inhibition of ribosomal protein synthesis is not known. Here, we show that stress specifically inhibits the first step of rRNA processing. Unprocessed rRNA is stored within the nucleolus, and when stress resolves, it re-enters the ribosome biogenesis pathway. Retention of unprocessed rRNA within the nucleolus aids in the maintenance of this organelle. This response is independent of the ISR or inhibition of cellular translation but is independently regulated. Failure to coordinately control ribosomal protein translation and rRNA production results in nucleolar fragmentation. Our study unveils how the rapid translational shut-off in response to stress coordinates with rRNA synthesis production to maintain nucleolar integrity.


Asunto(s)
ARN Ribosómico/metabolismo , Proteínas Ribosómicas/metabolismo , Ribosomas , Células HeLa , Humanos , Biogénesis de Organelos , Procesamiento Postranscripcional del ARN , Ribosomas/genética , Ribosomas/metabolismo , Estrés Fisiológico , Transcripción Genética
4.
J Bacteriol ; 204(3): e0061321, 2022 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-35041499

RESUMEN

DEAD-box proteins (DBPs) are a prominent class of RNA remodeling proteins that alter RNA structure, a process they typically perform through an ATP-dependent RNA helicase activity. Although many DBPs have been characterized at the structural and functional level in detail, much less is known about how they are regulated. We previously showed that the mRNA for the Escherichia coli DeaD DBP contains an unusually long 5' untranslated region (5' UTR) of 838 nucleotides (nt) and that it is the primary RNA determinant of DeaD autoregulation. We speculated that such a long and complex 5' UTR might regulate deaD expression in additional ways. Here, we show that the deaD mRNA 5' UTR regulates deaD expression at two additional levels, temperature-dependent expression and through a stem-loop structure overlapping the start codon. These results support the hypothesis that a long 5' UTR can regulate gene expression through multiple mechanisms. IMPORTANCE The expression of genes is frequently regulated by determinants in the 5' UTR. Although many different regulatory mechanisms that operate via the 5' UTR have been described, the functional relevance of genes with long UTRs is less clear. Here, we show that the 838-nt-long 5' UTR in the deaD mRNA regulates the expression of DeaD at multiple levels. We propose that long UTRs originate to provide precise control of gene expression through multiple regulatory mechanisms, and they are indicators of the importance of their associated gene products for cellular adaptation to different environments.


Asunto(s)
ARN Helicasas DEAD-box , Proteínas de Escherichia coli , Regiones no Traducidas 3' , Regiones no Traducidas 5' , ARN Helicasas DEAD-box/genética , ARN Helicasas DEAD-box/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , ARN Mensajero/metabolismo
5.
RNA ; 26(9): 1160-1169, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32414857

RESUMEN

DEAD-box proteins (DBPs) are RNA remodeling factors associated with RNA helicase activity that are found in nearly all organisms. Despite extensive studies on the mechanisms used by DBPs to regulate RNA function, very little is known about how DBPs themselves are regulated. In this work, we have analyzed the expression and regulation of DeaD/CsdA, the largest of the DBPs in Escherichia coli (E. coli). We show that deaD transcription initiates 838 nt upstream of the start of the coding region. We have also found that DeaD is autoregulated through a negative feedback mechanism that operates both at the level of deaD mRNA stability and Rho-dependent transcription termination, and this regulation is dependent upon its mRNA 5' untranslated region (5' UTR). These findings suggest that DeaD might be regulating the conformation of its own mRNA through its RNA helicase activity to facilitate ribonuclease and Rho access to its 5' UTR.


Asunto(s)
ARN Helicasas DEAD-box/genética , Escherichia coli/genética , Homeostasis/genética , Estabilidad del ARN/genética , ARN Mensajero/genética , Transcripción Genética/genética , Regiones no Traducidas 5'/genética , Proteínas de Escherichia coli/genética , Regulación Bacteriana de la Expresión Génica/genética , ARN Bacteriano/genética
6.
Nucleic Acids Res ; 48(11): 6223-6233, 2020 06 19.
Artículo en Inglés | MEDLINE | ID: mdl-32374873

RESUMEN

As cells encounter adverse environmental conditions, such as hypoxia, oxidative stress or nutrient deprivation, they trigger stress response pathways to protect themselves until transient stresses have passed. Inhibition of translation is a key component of such cellular stress responses and mounting evidence has revealed the importance of a class of tRNA-derived small RNAs called tiRNAs in this process. The most potent of these small RNAs are those with the capability of assembling into tetrameric G-quadruplex (G4) structures. However, the mechanism by which these small RNAs inhibit translation has yet to be elucidated. Here we show that eIF4G, the major scaffolding protein in the translation initiation complex, directly binds G4s and this activity is required for tiRNA-mediated translation repression. Targeting of eIF4G results in an impairment of 40S ribosome scanning on mRNAs leading to the formation of eIF2α-independent stress granules. Our data reveals the mechanism by which tiRNAs inhibit translation and demonstrates novel activity for eIF4G in the regulation of translation.


Asunto(s)
Factor 4G Eucariótico de Iniciación/metabolismo , G-Cuádruplex , Biosíntesis de Proteínas , ARN de Transferencia/química , ARN de Transferencia/metabolismo , Factor 2 Eucariótico de Iniciación/metabolismo , Factor 4F Eucariótico de Iniciación/química , Factor 4F Eucariótico de Iniciación/metabolismo , Humanos , Iniciación de la Cadena Peptídica Traduccional , Fosfoproteínas/metabolismo , Dominios Proteicos , ARN Mensajero/metabolismo , ARN de Transferencia/genética , Subunidades Ribosómicas Pequeñas de Eucariotas/metabolismo
7.
Cult Health Sex ; 21(12): 1409-1424, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-30730251

RESUMEN

Although the importance of working with young men to transform traditional gender norms has been widely acknowledged, programmes for young men remain sparse in highly gender stratified settings such as India, and those that have been implemented have not reached those in rural areas and those out-of-school. Drawing on data from a cluster randomised controlled trial with panel surveys, of a gender-transformative life skills education and sports-coaching programme conducted among young men aged 13-21 who were members of youth clubs, this paper examines the extent to which it transformed the gender role attitudes of young men and instilled in them attitudes rejecting violence against women and girls. The intervention succeeded in changing gender role attitudes and notions of masculinity, attitudes about men's controlling behaviours over women/girls, attitudes about men's perpetration of violence on a woman/girl and perceptions about peer reactions to young men acting in gender-equitable ways. Effects were particularly significant among young men who attended regularly, underscoring the importance of regular attendance in such programmes.


Asunto(s)
Actitud , Identidad de Género , Violencia de Género/prevención & control , Hombres/psicología , Adolescente , Adulto , Femenino , Humanos , India , Masculino , Evaluación de Programas y Proyectos de Salud , Deportes , Encuestas y Cuestionarios , Adulto Joven
8.
Acta Cytol ; 58(1): 33-41, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24296489

RESUMEN

OBJECTIVE: To evaluate the role of squash cytology in rapid on-site adequacy checking (ROSAC) of image-guided gun biopsy and to determine its diagnostic accuracy at a tertiary cancer center. STUDY DESIGN: This was a prospective study on 183 patients undergoing image-guided biopsy. Squash smears were prepared from biopsy cores and checked for adequacy by cytotechnologists. When adequate, more cores were sampled from the same area for histopathology. If inadequate, the procedure was repeated at the same sitting on a different area. The squash smears were reported by cytopathologists within 4 h after staining with conventional Papanicoloau stain. The results were compared with the final histopathology report. RESULTS: The sampling was representative in 95.6% cases with concordance for adequacy in 97.3% cases. The sensitivity, specificity, positive predictive value and negative predictive value of squash cytology for diagnosis of the lesion were 99.4, 92.7, 97.7 and 97.4%, respectively. CONCLUSIONS: Squash cytology is an ideal and cost-effective technique for ROSAC of image-guided biopsies, which ensures adequacy, avoids repeat procedures and prevents delay in diagnosis. It can be effectively performed by trained cytotechnologists in radiology clinics. Squash cytology is also a cost-effective tool offering rapid diagnosis which expedites planning of treatment.


Asunto(s)
Citodiagnóstico/métodos , Neoplasias/patología , Adulto , Femenino , Humanos , Biopsia Guiada por Imagen , Masculino , Persona de Mediana Edad , Prueba de Papanicolaou , Sensibilidad y Especificidad , Manejo de Especímenes
9.
Cureus ; 16(5): e60898, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38784689

RESUMEN

Background The hepatoprotective function of polyherbal formulation Liv.52 in chronic liver diseases is well recognized in published literature. The objective of this open-label, phase IV study was to further strengthen and validate its safety and effectiveness using a large patient pool in a real-world scenario and provide scientific data on symptomatic improvement and supportive treatment in liver function with improvement in quality of life. Methods Adult patients of either sex with one or more clinical symptoms like fatigue, nausea, anorexia, abdominal pain or discomfort, muscle cramps, jaundice, or any other signs and symptoms with a history suggestive of mild-to-moderate hepatic disorders like alcoholic liver disease (ALD), non-alcoholic fatty liver disease (NAFLD), drug-induced hepatotoxicity, or hepatitis were treated with two Liv.52 DS tablets (oral) twice daily for 12 weeks. Results Out of the 1000 enrolled patients, 962 (96%) completed the study with the following subgroups ALD: 375 (38.9%), NAFLD: 379 (39.3%), drug-induced hepatotoxicity: 78 (8.1%), hepatitis: 130 (13.5%). The mean age of enrolled patients was 37.7 years, and the majority of them, 785 (78.5%) were men. The common adverse events observed (with >1.5% incidence) in the study were abdominal pain: 26 (2.6%) and headache: 17 (1.7%). Liv.52 showed statistically significant improvement (P<0.0001) in various clinical signs and symptoms in the majority of patients namely, fatigue: 357/723 (49%), anorexia: 485/620 (78.2%), jaundice: 48/52 (92%). Majority of the patients showed significant improvements from baseline to end of 12 weeks in the liver function test parameters namely, aspartate aminotransferase: 633/840 (75.36%), alanine aminotransferase: 592/729 (81.21%), serum bilirubin: 244/347 (70.32%), alkaline phosphatase: 279/355 (78.59%) with P<0.0001 for all parameters. Statistically significant improvement (P<0.005) was also seen in all the components of the chronic liver disease questionnaire (CLDQ) scores from baseline to 12 weeks. Conclusions The study demonstrated that Liv.52 was hepatoprotective and well tolerated in the study population after treatment for 12 weeks. Significant improvements were seen in clinical signs and symptoms, laboratory parameters of liver function, and CLDQ scores from baseline to 12 weeks. No significant or new safety signals emerged from this study.

10.
Acta Cytol ; 57(4): 413-7, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23860383

RESUMEN

OBJECTIVE: To put forth the cytological features and diagnostic pitfalls of spontaneously infarcted breast lesions on fine-needle aspiration cytology (FNAC). STUDY DESIGN: We present 19 cases of spontaneously infarcted breast lesions encountered on FNAC over a 5-year period. Histological follow-up was correlated wherever available. RESULTS: The majority of cases were seen in the second decade of life. The smears in all 19 cases were cellular. The cytomorphologic findings were scattered dyscohesive cells (n = 16), ghost cells (n = 11) and necrosis (n = 10). The dyscohesive cells were small and had a normal nuclear cytoplasmic ratio with pyknotic nuclei. The presence of viable epithelial cells or stromal fragments helped in the diagnosis of the primary breast lesion and was seen in all 19 cases. Cytology diagnoses were infarcted fibroadenoma (n = 11), infarcted breast lesion (n = 3), Phyllodes tumor (n = 2), papillary lesion (n = 2) and infarcted benign breast lesion (n = 1). Histopathology was available in 13 cases, 12 were concordant and 1 was inadequate for primary diagnosis. CONCLUSION: An infarcted breast lesion poses diagnostic difficulties on cytology. It needs to be differentiated from inflammatory lesions and malignancy. A cytopathologist should be aware of the entity and recognize its cytomorphologic features.


Asunto(s)
Enfermedades de la Mama/diagnóstico , Mama/irrigación sanguínea , Citodiagnóstico , Infarto/patología , Biopsia con Aguja Fina , Mama/patología , Femenino , Humanos
11.
Acta Cytol ; 56(3): 325-9, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22555538

RESUMEN

OBJECTIVE: To analyze the cases diagnosed as myeloid sarcoma on fine-needle aspiration cytology (FNAC) of lymph nodes. STUDY DESIGN: Ten cases of lymph node aspirate diagnosed as myeloid sarcoma were analyzed. FNAC was performed as a routine outpatient procedure in all cases. Correlation with peripheral smear, bone marrow examination, flow cytometry and cytogenetics was done wherever possible. RESULTS: Diagnosis of a hematologic malignancy, before fine-needle aspiration, was available in only 2 cases. All 10 cases showed eosinophilic precursors while five aspirates showed megakaryocytes with dysplastic forms. Of the 10 cases, 3 were diagnosed as acute myeloid leukemia, 3 as chronic myeloid leukemia, 1 case as juvenile myelomonocytic leukemia, 1 case proved to be precursor T acute lymphoblastic leukemia/lymphoma and 2 patients did not show blasts on peripheral blood smear but showed blasts, dysplastic megakaryocytes and eosinophilic precursors in the aspirate. CONCLUSION: Thorough workup to search for an underlying hematological malignancy should be done whenever dysplastic megakaryocytes and/or eosinophilic precursors are seen in lymph node aspirate.


Asunto(s)
Biopsia con Aguja Fina/métodos , Eosinófilos/patología , Células Precursoras Eritroides/patología , Ganglios Linfáticos/patología , Megacariocitos/patología , Sarcoma Mieloide/patología , Adolescente , Adulto , Anciano , Preescolar , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sarcoma Mieloide/diagnóstico , Adulto Joven
12.
Acta Cytol ; 55(5): 481-4, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21986179

RESUMEN

BACKGROUND: Infantile digital fibromatosis (IDF) or inclusion body fibromatosis is a benign proliferation of fibroblastic and myofibroblastic cells. Its most common site is the digits of young children and it is named for the intracytoplasmic inclusions that are detected in lesional cells. CASE: A two and a half-year-old male child presented with a single flesh-colored nodule on the dorsal aspect of his right little toe since the sixth month of life. FNAC from the lesion showed characteristic cytomorphological features of IDF. CONCLUSION: IDF is a rare lesion occurring in children or infants. There are many case reports describing histopathological features of IDF. To our knowledge, the typical inclusion bodies as cytomorphological findings in IDF have not been described in the literature. This is a rare case diagnosed on cytology and confirmed on histopathology.


Asunto(s)
Citodiagnóstico , Fibroma/diagnóstico , Neoplasias Cutáneas/diagnóstico , Dedos del Pie/patología , Biopsia con Aguja Fina , Preescolar , Humanos , Cuerpos de Inclusión , Masculino
13.
Biomolecules ; 10(5)2020 05 18.
Artículo en Inglés | MEDLINE | ID: mdl-32443616

RESUMEN

Ribosomes are perhaps the most critical macromolecular machine as they are tasked with carrying out protein synthesis in cells. They are incredibly complex structures composed of protein components and heavily chemically modified RNAs. The task of assembling mature ribosomes from their component parts consumes a massive amount of energy and requires greater than 200 assembly factors. Among the most critical of these are small nucleolar ribonucleoproteins (snoRNPs). These are small RNAs complexed with diverse sets of proteins. As suggested by their name, they localize to the nucleolus, the site of ribosome biogenesis. There, they facilitate multiple roles in ribosomes biogenesis, such as pseudouridylation and 2'-O-methylation of ribosomal (r)RNA, guiding pre-rRNA processing, and acting as molecular chaperones. Here, we reviewed their activity in promoting the assembly of ribosomes in eukaryotes with regards to chemical modification and pre-rRNA processing.


Asunto(s)
Biogénesis de Organelos , Ribonucleoproteínas Nucleares Pequeñas/metabolismo , Ribosomas/metabolismo , Animales , Humanos , ARN Ribosómico/genética , ARN Ribosómico/metabolismo , Ribonucleoproteínas Nucleares Pequeñas/química
14.
J Cancer Res Ther ; 15(1): 261-263, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30880790

RESUMEN

Tailgut cysts (TGCs) are rare congenital lesions derived from the remnants of primitive hindgut and are usually lined by squamous, transitional, or glandular epithelium. Malignant transformation in TGC may occur which is still rarer. Most common malignancies that arise from these cysts are adenocarcinomas. Preoperative diagnosis is difficult as high degree of suspicion is required for the diagnosis. We report here a case of adenocarcinoma arising in a tale gut cyst diagnosed preoperatively and till date very few cases have been reported in literature.


Asunto(s)
Adenocarcinoma/diagnóstico , Quistes/diagnóstico , Neoplasias de Células Germinales y Embrionarias/diagnóstico , Adenocarcinoma/patología , Adenocarcinoma/cirugía , Adulto , Quistes/patología , Quistes/cirugía , Diagnóstico Diferencial , Humanos , Imagen por Resonancia Magnética , Masculino , Neoplasias de Células Germinales y Embrionarias/patología , Neoplasias de Células Germinales y Embrionarias/cirugía , Región Sacrococcígea/diagnóstico por imagen , Región Sacrococcígea/patología , Región Sacrococcígea/cirugía , Resultado del Tratamiento
15.
J Lab Physicians ; 10(1): 118-120, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29403220

RESUMEN

Brown tumor (BT) is caused by altered metabolism of calcium resulting from hyperparathyroidism (primary or secondary). The most common cause of hyperparathyroidism is isolated parathyroid adenoma (PA), and the most common symptoms are hypercalcemia related. BT is considered as a late manifestation of PA and usually diagnosed after surgical treatment of the bony lesion. Fine-needle aspiration cytology (FNAC) is a cheap, easy, and less traumatic procedure and should be performed in all lesions wherever possible as unnecessary surgeries may be avoided. We here report a rare case of PA presenting primarily as BT and diagnosed on FNAC.

16.
Acta Cytol ; 62(2): 145-150, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29275417

RESUMEN

BACKGROUND: Follicular dendritic cell sarcoma (FDCS) is a rare neoplasm arising from follicular dendritic cells of germinal centers. The most common site of origin is lymph nodes and it may mimic a variety of tumors at that location, including carcinomas and sarcomas. Diagnosis is frequently missed on cytology as there are very few case reports describing the cytological characteristics of the lesion. Even on histology, a high degree of suspicion is required for an appropriate diagnosis. CASE: A 60-year-old male presented with a gradually increasing left submandibular mass that had been present for 3 months. Fine-needle aspiration cytology (FNAC) was performed, showing many clusters as well as scattered epithelioid cells with spindled to oval nuclei, nuclear pleomorphism, grooves, inclusions, and uniformly dispersed mature lymphocytes throughout the smears. The diagnosis of FDCS was suspected and was confirmed on histopathology and immunohistochemistry. CONCLUSION: FNAC can be a cheap, easy, and helpful tool in obtaining a diagnosis of FDCS as there are few characteristic cytological features that are better recognized than histology.


Asunto(s)
Sarcoma de Células Dendríticas Foliculares/patología , Ganglios Linfáticos/patología , Biomarcadores de Tumor/análisis , Biopsia con Aguja Fina , Sarcoma de Células Dendríticas Foliculares/metabolismo , Sarcoma de Células Dendríticas Foliculares/cirugía , Diagnóstico Diferencial , Humanos , Inmunohistoquímica , Ganglios Linfáticos/química , Ganglios Linfáticos/cirugía , Masculino , Persona de Mediana Edad , Disección del Cuello , Valor Predictivo de las Pruebas
17.
Acta Cytol ; 62(5-6): 327-332, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29940582

RESUMEN

OBJECTIVE: To study the role of Field staining in scrape smears for intraoperative cytological (IOC) diagnosis. Specimens were assessed for categorizing among benign and malignant lesions, lymph node status, and adequacy of surgical cut margins as per specimen. Technique, adequacy, and quality were assessed along with comparison of cytological diagnosis with final histopathological diagnosis obtained on routine hematoxylin and eosin-stained slides. STUDY DESIGN: A prospective observational study was conducted over a period of 1 year from November 2016 to October 2017 in the Department of Pathology of our Institute. RESULTS: 50 cases were studied, and scrape smears were stained with Field stain. Results were satisfactory in terms of adequacy and attaining the objectives of the study. A diagnostic accuracy of 98% was observed with an average turnaround time of 5 min. A single case of low-grade glioma was found to be discordant. CONCLUSIONS: Use of Field staining for intraoper-ative cytological assessment of surgical specimens has 98% concordance with the final histopathological diagnosis and achieved the aim of the study. With its low costs, easy availability, short turnaround time, and simple technique, it will be helpful in IOC as an alternative to present techniques especially in financially constrained settings.


Asunto(s)
Citodiagnóstico/métodos , Cuidados Intraoperatorios/métodos , Ganglios Linfáticos/patología , Ganglios Linfáticos/cirugía , Neoplasias/patología , Neoplasias/cirugía , Manejo de Especímenes/métodos , Coloración y Etiquetado/métodos , Colorantes , Eosina Amarillenta-(YS) , Hematoxilina , Humanos , Metástasis Linfática , Márgenes de Escisión , Valor Predictivo de las Pruebas , Estudios Prospectivos , Reproducibilidad de los Resultados
18.
J Clin Diagn Res ; 11(4): ED03-ED04, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28571151

RESUMEN

Leiomyosarcomas (LMS) arising from vascular channel are rare and more often arise from inferior vena cava and pulmonary arteries. Primary renal vein LMS are even rarer and occur predominantly in females with peak in fifth and sixth decade. Preoperative diagnosis is difficult because these are rare tumours and present with symptoms and radiological findings similar to Renal Cell Carcinoma (RCC). We report a case of 55-year-old female who presented with abdominal discomfort with radiology showing a renal mass with features of RCC, radical nephrectomy was done and resected tumour showed an attachment to the wall of renal vein with morphology resembling LMS.

19.
Mol Biochem Parasitol ; 201(2): 146-52, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26247142

RESUMEN

Ribosome synthesis involves all three RNA polymerases which are co-ordinately regulated to produce equimolar amounts of rRNAs and ribosomal proteins (RPs). Unlike model organisms where transcription of rRNA and RP genes slows down during stress, in E. histolytica rDNA transcription continues but pre-rRNA processing slows down and unprocessed pre-rRNA accumulates during serum starvation. To investigate the regulation of RP genes under stress we measured transcription of six selected RP genes from the small- and large-ribosomal subunits (RPS6, RPS3, RPS19, RPL5, RPL26, RPL30) representing the early-, mid-, and late-stages of ribosomal assembly. Transcripts of these genes persisted in growth-stressed cells. Expression of luciferase reporter under the control of two RP genes (RPS19 and RPL30) was studied during serum starvation and upon serum replenishment. Although luciferase transcript levels remained unchanged during starvation, luciferase activity steadily declined to 7.8% and 15% of control cells, respectively. After serum replenishment the activity increased to normal levels, suggesting post-transcriptional regulation of these genes. Mutations in the sequence -2 to -9 upstream of AUG in the RPL30 gene resulted in the phenotype expected of post-transcriptional regulation. Transcription of luciferase reporter was unaffected in this mutant, and luciferase activity did not decline during serum starvation, showing that this sequence is required to repress translation of RPL30 mRNA, and mutations in this region relieve repression. Our data show that during serum starvation E. histolytica blocks ribosome biogenesis post-transcriptionally by inhibiting pre-rRNA processing on the one hand, and the translation of RP mRNAs on the other.


Asunto(s)
Entamoeba histolytica/crecimiento & desarrollo , Entamoeba histolytica/genética , Regulación de la Expresión Génica , Procesamiento Postranscripcional del ARN , Proteínas Ribosómicas/biosíntesis , Fusión Artificial Génica , Medio de Cultivo Libre de Suero , Entamoeba histolytica/fisiología , Genes Reporteros , Luciferasas/análisis , Luciferasas/genética , Biosíntesis de Proteínas , Secuencias Reguladoras de Ácido Ribonucleico , Estrés Fisiológico
20.
Mob DNA ; 6: 14, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26339297

RESUMEN

BACKGROUND: In the compact and haploid genome of Dictyostelium discoideum control of transposon activity is of particular importance to maintain viability. The non-long terminal repeat retrotransposon TRE5-A amplifies continuously in D. discoideum cells even though it produces considerable amounts of minus-strand (antisense) RNA in the presence of an active RNA interference machinery. Removal of the host-encoded C-module-binding factor (CbfA) from D. discoideum cells resulted in a more than 90 % reduction of both plus- and minus-strand RNA of TRE5-A and a strong decrease of the retrotransposition activity of the cellular TRE5-A population. Transcriptome analysis revealed an approximately 230-fold overexpression of the gene coding for the Argonaute-like protein AgnC in a CbfA-depleted mutant. RESULTS: The D. discoideum genome contains orthologs of RNA-dependent RNA polymerases, Dicer-like proteins, and Argonaute proteins that are supposed to represent RNA interference pathways. We analyzed available mutants in these genes for altered expression of TRE5-A. We found that the retrotransposon was overexpressed in mutants lacking the Argonaute proteins AgnC and AgnE. Because the agnC gene is barely expressed in wild-type cells, probably due to repression by CbfA, we employed a new method of promoter-swapping to overexpress agnC in a CbfA-independent manner. In these strains we established an in vivo retrotransposition assay that determines the retrotransposition frequency of the cellular TRE5-A population. We observed that both the TRE5-A steady-state RNA level and retrotransposition rate dropped to less than 10 % of wild-type in the agnC overexpressor strains. CONCLUSIONS: The data suggest that TRE5-A amplification is controlled by a distinct pathway of the Dictyostelium RNA interference machinery that does not require RNA-dependent RNA polymerases but involves AgnC. This control is at least partially overcome by the activity of CbfA, a factor derived from the retrotransposon's host. This unusual regulation of mobile element activity most likely had a profound effect on genome evolution in D. discoideum.

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