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1.
Cell ; 187(2): 331-344.e17, 2024 01 18.
Artículo en Inglés | MEDLINE | ID: mdl-38194964

RESUMEN

Enhancers are distal DNA elements believed to loop and contact promoters to control gene expression. Recently, we found diffraction-sized transcriptional condensates at genes controlled by clusters of enhancers (super-enhancers). However, a direct function of endogenous condensates in controlling gene expression remains elusive. Here, we develop live-cell super-resolution and multi-color 3D-imaging approaches to investigate putative roles of endogenous condensates in the regulation of super-enhancer controlled gene Sox2. In contrast to enhancer distance, we find instead that the condensate's positional dynamics are a better predictor of gene expression. A basal gene bursting occurs when the condensate is far (>1 µm), but burst size and frequency are enhanced when the condensate moves in proximity (<1 µm). Perturbations of cohesin and local DNA elements do not prevent basal bursting but affect the condensate and its burst enhancement. We propose a three-way kissing model whereby the condensate interacts transiently with gene locus and regulatory DNA elements to control gene bursting.


Asunto(s)
Regulación de la Expresión Génica , Factores de Transcripción SOXB1 , Súper Potenciadores , Transcripción Genética , ADN/genética , Elementos de Facilitación Genéticos , Factores de Transcripción SOXB1/genética , Animales , Ratones , Células Madre Embrionarias/metabolismo , Microscopía/métodos
2.
Cell ; 184(1): 207-225.e24, 2021 01 07.
Artículo en Inglés | MEDLINE | ID: mdl-33333019

RESUMEN

Regulation of biological processes typically incorporates mechanisms that initiate and terminate the process and, where understood, these mechanisms often involve feedback control. Regulation of transcription is a fundamental cellular process where the mechanisms involved in initiation have been studied extensively, but those involved in arresting the process are poorly understood. Modeling of the potential roles of RNA in transcriptional control suggested a non-equilibrium feedback control mechanism where low levels of RNA promote condensates formed by electrostatic interactions whereas relatively high levels promote dissolution of these condensates. Evidence from in vitro and in vivo experiments support a model where RNAs produced during early steps in transcription initiation stimulate condensate formation, whereas the burst of RNAs produced during elongation stimulate condensate dissolution. We propose that transcriptional regulation incorporates a feedback mechanism whereby transcribed RNAs initially stimulate but then ultimately arrest the process.


Asunto(s)
Retroalimentación Fisiológica , ARN/genética , Transcripción Genética , Animales , Complejo Mediador/metabolismo , Ratones , Modelos Biológicos , Células Madre Embrionarias de Ratones/metabolismo , ARN/biosíntesis , Electricidad Estática
4.
Nature ; 626(7997): 212-220, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38086419

RESUMEN

Transcriptional enhancers act as docking stations for combinations of transcription factors and thereby regulate spatiotemporal activation of their target genes1. It has been a long-standing goal in the field to decode the regulatory logic of an enhancer and to understand the details of how spatiotemporal gene expression is encoded in an enhancer sequence. Here we show that deep learning models2-6, can be used to efficiently design synthetic, cell-type-specific enhancers, starting from random sequences, and that this optimization process allows detailed tracing of enhancer features at single-nucleotide resolution. We evaluate the function of fully synthetic enhancers to specifically target Kenyon cells or glial cells in the fruit fly brain using transgenic animals. We further exploit enhancer design to create 'dual-code' enhancers that target two cell types and minimal enhancers smaller than 50 base pairs that are fully functional. By examining the state space searches towards local optima, we characterize enhancer codes through the strength, combination and arrangement of transcription factor activator and transcription factor repressor motifs. Finally, we apply the same strategies to successfully design human enhancers, which adhere to enhancer rules similar to those of Drosophila enhancers. Enhancer design guided by deep learning leads to better understanding of how enhancers work and shows that their code can be exploited to manipulate cell states.


Asunto(s)
Células , Aprendizaje Profundo , Drosophila melanogaster , Elementos de Facilitación Genéticos , Biología Sintética , Animales , Humanos , Animales Modificados Genéticamente/genética , Elementos de Facilitación Genéticos/genética , Regulación de la Expresión Génica , Factores de Transcripción/metabolismo , Células/clasificación , Células/metabolismo , Neuroglía/metabolismo , Encéfalo/citología , Drosophila melanogaster/citología , Drosophila melanogaster/genética , Proteínas Represoras/metabolismo
5.
Mol Cell ; 76(5): 753-766.e6, 2019 12 05.
Artículo en Inglés | MEDLINE | ID: mdl-31563432

RESUMEN

The gene expression programs that define the identity of each cell are controlled by master transcription factors (TFs) that bind cell-type-specific enhancers, as well as signaling factors, which bring extracellular stimuli to these enhancers. Recent studies have revealed that master TFs form phase-separated condensates with the Mediator coactivator at super-enhancers. Here, we present evidence that signaling factors for the WNT, TGF-ß, and JAK/STAT pathways use their intrinsically disordered regions (IDRs) to enter and concentrate in Mediator condensates at super-enhancers. We show that the WNT coactivator ß-catenin interacts both with components of condensates and DNA-binding factors to selectively occupy super-enhancer-associated genes. We propose that the cell-type specificity of the response to signaling is mediated in part by the IDRs of the signaling factors, which cause these factors to partition into condensates established by the master TFs and Mediator at genes with prominent roles in cell identity.


Asunto(s)
Elementos de Facilitación Genéticos/genética , Complejo Mediador/metabolismo , Factores de Transcripción/metabolismo , Animales , Línea Celular , Regulación de la Expresión Génica/fisiología , Humanos , Proteínas Intrínsecamente Desordenadas/metabolismo , Complejo Mediador/fisiología , Factores de Transcripción STAT/metabolismo , Factor de Transcripción STAT3/metabolismo , Transducción de Señal/fisiología , Proteína smad3/metabolismo , Proteínas de la Superfamilia TGF-beta/metabolismo , Transcripción Genética , Vía de Señalización Wnt , beta Catenina/metabolismo
6.
Nature ; 572(7770): 543-548, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31391587

RESUMEN

The synthesis of pre-mRNA by RNA polymerase II (Pol II) involves the formation of a transcription initiation complex, and a transition to an elongation complex1-4. The large subunit of Pol II contains an intrinsically disordered C-terminal domain that is phosphorylated by cyclin-dependent kinases during the transition from initiation to elongation, thus influencing the interaction of the C-terminal domain with different components of the initiation or the RNA-splicing apparatus5,6. Recent observations suggest that this model provides only a partial picture of the effects of phosphorylation of the C-terminal domain7-12. Both the transcription-initiation machinery and the splicing machinery can form phase-separated condensates that contain large numbers of component molecules: hundreds of molecules of Pol II and mediator are concentrated in condensates at super-enhancers7,8, and large numbers of splicing factors are concentrated in nuclear speckles, some of which occur at highly active transcription sites9-12. Here we investigate whether the phosphorylation of the Pol II C-terminal domain regulates the incorporation of Pol II into phase-separated condensates that are associated with transcription initiation and splicing. We find that the hypophosphorylated C-terminal domain of Pol II is incorporated into mediator condensates and that phosphorylation by regulatory cyclin-dependent kinases reduces this incorporation. We also find that the hyperphosphorylated C-terminal domain is preferentially incorporated into condensates that are formed by splicing factors. These results suggest that phosphorylation of the Pol II C-terminal domain drives an exchange from condensates that are involved in transcription initiation to those that are involved in RNA processing, and implicates phosphorylation as a mechanism that regulates condensate preference.


Asunto(s)
Complejo Mediador/química , Complejo Mediador/metabolismo , ARN Polimerasa II/química , ARN Polimerasa II/metabolismo , Empalme del ARN , Transcripción Genética , Animales , Línea Celular , Elementos de Facilitación Genéticos/genética , Regulación de la Expresión Génica/genética , Humanos , Complejo Mediador/genética , Ratones , Fosforilación , Dominios Proteicos , ARN Polimerasa II/genética , Factores de Empalme de ARN/química , Factores de Empalme de ARN/genética , Factores de Empalme de ARN/metabolismo
7.
BMC Infect Dis ; 24(1): 156, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38302888

RESUMEN

BACKGROUND: Previous studies show increased morbidity in children who are HIV-exposed but uninfected (HEU) compared to children who are HIV-unexposed uninfected (HUU). We sought to evaluate the effects of prenatal HIV exposure on clinical and immunological outcomes in the first 24 months of life. METHODS: Eighty-five HEU and 168 HUU children from Kenya were followed from birth to 24 months. All mothers living with HIV received combination antiretroviral therapy. Children who were HEU received standard-of-care cotrimoxazole prophylaxis through 18 months. Episodes of acute illness were identified through a combination of active and passive follow up. Trajectories of plasma cytokines, vaccine-specific antibodies, and antimalarial antibodies were examined. RESULTS: Children who were HEU and children who were HUU had similar growth curves. Children who were HEU had lower rates of malaria (rate ratio 0.54, 95% CI 0.38, 0.77) and respiratory illness (rate ratio 0.80, 95% CI 0.68, 0.93). Trajectories of plasma cytokines and vaccine-specific antibodies were similar in children who were HEU and HUU. There were subtle differences in antimalarial antibody dynamics, in which children who were HEU had overall lower antibody levels against five of the 14 malaria antigens tested. CONCLUSIONS: Children who were HEU and born to optimally treated mothers living with HIV had similar growth characteristics and immune profiles compared to children who were HUU. Children who were HEU had reduced risk for malaria and respiratory illness, which may be secondary to cotrimoxazole prophylaxis.


Asunto(s)
Antimaláricos , Infecciones por VIH , Malaria , Vacunas , Niño , Embarazo , Femenino , Humanos , Lactante , Antimaláricos/uso terapéutico , Combinación Trimetoprim y Sulfametoxazol/uso terapéutico , Kenia/epidemiología , Infecciones por VIH/complicaciones , Malaria/tratamiento farmacológico , Malaria/complicaciones , Anticuerpos , Citocinas , Vacunas/uso terapéutico
8.
Trop Anim Health Prod ; 56(3): 112, 2024 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-38526648

RESUMEN

The study assessed the quality and variability of camel hair fibres in arid regions of Egypt. Raw camel-hair samples were collected from fifteen Sudanese camels divided into seven males (414.60 ± 38.19 kg, BW) and eight females (401.67 ± 26.76 kg BW), and the study investigated the influences of animal sex on both the physical and chemical traits of camel-hair fibers. The relationships among physical properties and both mineral and amino acid content were studied. Camel's sex had no significant effect on any of the studied traits including fibre diameter (FD), prickle factor (PF), medullated fibre (MF), staple length (SL) and staple strength (SS). In the meantime, no significant differences were found between males and females in fibers' minerals contents except potassium, where fibres of females had significantly higher potassium content than those of males. For amino acids contents in camel fibres, camel sex had a significant effect only on glutamic acid, since fibres of males showed higher (P < 0.05) content than females. Fibre diameter had positive (P < 0.01) correlations with prickle factor (r = 0.83) and medullated fibres (r = 0.73). Zinc content in camel fibres was positively correlated with fibre diameter (r = 0.57; P < 0.05) and medullated fibres (r = 0.73; P < 0.01). Moreover, a significant (negative correlation coefficient P < 0.05) was found between fibre diameter and both sulfur and proline contents (r=-0.39 and - 0.56). Ammonia content in fibres was correlated negatively (P < 0.05) with prickle factor and elongation (r=-0.62 and - 0.58, respectively). The variability in the physical properties and chemical composition of Sudanese camel-hair fibers under subtropical desert conditions may shed light on the possibility of improving fiber quality.


Asunto(s)
Camelus , Cabello , Masculino , Femenino , Animales , Minerales , Potasio , Egipto
9.
Cardiol Young ; 33(3): 354-361, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36259152

RESUMEN

We report our experience and early outcomes of using the BeGraft aortic stent in children, adolescents, and young adults. BeGraft aortic stent (Bentley InnoMed, Hechingen, Germany) requires a smaller long sheath compared to other covered stents, and it has a low profile and adequate radial power. With these features, it can overcome some limitations in the treatment of coarctation, especially in children. This is a single centre retrospective analysis of 11 implanted BeGraft aortic stents in coarctation of the aorta between July 2020 and November 2021. The eleven stents were successfully implanted in 11 patients (10 males). The median age of the patients was 13.7 years (interquartile range 12-16 years), and the median weight was 43 kg (interquartile range 35-62 kg). In five patients, after the stents were opened completely by the first balloon, they were exchanged with a Z-MED II™ balloon, 1-3 mm larger in diameter, and the stents were redilated. The median catheter-derived systolic peak-to-peak pressure gradient was 23 mm Hg (interquartile range 16-37 mmHg) before the procedure and 3 mm Hg (interquartile range 1-5 mm Hg) after the procedure. Except for the partial femoral artery thrombosis in two patients, no other procedural complications were observed in our study. The median follow-up duration was 5 months (interquartile range 2-12 months). During follow-up, only one patient (9%) had stent narrowing that required dilation. Our initial results and short-term follow-up showed that the BeGraft aortic stent implantation and redilation can be performed effectively, safely, and successfully in the treatment of coarctation of the aorta.


Asunto(s)
Coartación Aórtica , Masculino , Adolescente , Humanos , Niño , Adulto Joven , Coartación Aórtica/cirugía , Estudios Retrospectivos , Resultado del Tratamiento , Stents , Aorta/cirugía
10.
Fish Physiol Biochem ; 49(1): 1-17, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36622623

RESUMEN

This study focuses on the relationship between myostatin (MyoS), myogenin (MyoG), and the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis for muscle growth and histopathological changes in muscle after an Aeromonas hydrophila infection. A total number of 90 Nile tilapia (55.85 g) were randomly allocated into two equal groups of three replicates each. The first group was an uninfected control group that was injected intraperitoneally (ip) with 0.2 ml phosphate buffer saline (PBS), while the second group was injected ip with 0.2 ml (1.3 × 108 CFU/ml) Aeromonas hydrophila culture suspension. Sections of white muscle and liver tissues were taken from each group 24 h, 48 h, 72 h, and 1 week after infection for molecular analysis and histopathological examination. The results revealed that with time progression, the severity of muscle lesions increased from edema between bundles and mononuclear inflammatory cell infiltration 24 h post-challenge to severe atrophy of muscle bundles with irregular and curved fibers with hyalinosis of the fibers 1 week postinfection. The molecular analysis showed that bacterial infection was able to induce the muscle expression levels of GH with reduced ILGF-1, MyoS, and MyoG at 24 h postinfection. However, time progression postinfection reversed these findings through elevated muscle expression levels of MyoS with regressed expression levels of muscle GH, ILGF-1, and MyoG. There have been no previous reports on the molecular expression analysis of the aforementioned genes and muscle histopathological changes in Nile tilapia following acute Aeromonas hydrophila infection. Our findings, collectively, revealed that the up-and down-regulation of the myostatin signaling is likely to be involved in the postinfection-induced muscle wasting through the negative regulation of genes involved in muscle growth, such as GH, ILGF-1, and myogenin, in response to acute Aeromonas hydrophila infection in Nile tilapia, Oreochromis niloticus.


Asunto(s)
Cíclidos , Enfermedades de los Peces , Infecciones por Bacterias Gramnegativas , Animales , Dieta , Aeromonas hydrophila , Miogenina/metabolismo , Miostatina/genética , Miostatina/metabolismo , Infecciones por Bacterias Gramnegativas/veterinaria , Infecciones por Bacterias Gramnegativas/microbiología , Músculo Esquelético , Enfermedades de los Peces/microbiología
11.
Trop Anim Health Prod ; 55(3): 207, 2023 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-37199866

RESUMEN

Sheep is an important producing animal in subtropical and arid regions; however, sheep farming practices and welfare standards are still not well established. To move to either intensive or intensive sheep production, stocking density (animal/area, SD) is a significant factor that influencing the welfare and productivity of animals. However, there are discrepancies in space allowance standards for wool, meat, and dairy sheep at different stages. Thus, this review article sheds light on (1) the geographical distribution of wool, meat-type, and dairy sheep populations; (2) the effects of interaction among space allowances, housing systems, and group size on the social, feeding, and aggressive behaviors and human-sheep contact; (3) the effects of space allowance on wool, growth performance, and milk production of sheep; (4) the relationship between space allowance and reproductive performance; (5) the effects of stocking rate on immunity; and (6) suggestions to mitigate the stress and deleterious influences of SD on the productivity of sheep. In conclusion, the larger space allowance with access to an outdoor yard can improve social and feeding behaviors, meat and milk yield, and wool quality. Moreover, ewes are more sensitive to SD, so they should receive an adequate space allowance at each stage. The changes in behavioral responses of each sheep breed refer to their different requirements. Therefore, there is a need to determine the impact of housing aspects, especially space allowance and enrichment tools on the productive performance and welfare indices of sheep for implementing welfare-economic standards for sheep production.


Asunto(s)
Vivienda para Animales , Reproducción , Humanos , Ovinos , Animales , Femenino , Leche , Agresión , Conducta Alimentaria
12.
Pancreatology ; 22(4): 497-506, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35414481

RESUMEN

BACKGROUND: Surveillance of individuals at risk of developing pancreatic ductal adenocarcinoma (PDAC) has the potential to improve survival, yet early detection based on solely imaging modalities is challenging. We aimed to identify changes in serum glycosylation levels over time to earlier detect PDAC in high-risk individuals. METHODS: Individuals with a hereditary predisposition to develop PDAC were followed in two surveillance programs. Those, of which at least two consecutive serum samples were available, were included. Mass spectrometry analysis was performed to determine the total N-glycome for each consecutive sample. Potentially discriminating N-glycans were selected based on our previous cross-sectional analysis and relative abundances were calculated for each glycosylation feature. RESULTS: 165 individuals ("FPC-cohort" N = 119; Leiden cohort N = 46) were included. In total, 97 (59%) individuals had a genetic predisposition (77 CDKN2A, 15 BRCA1/2, 5 STK11) and 68 (41%) a family history of PDAC without a known genetic predisposition (>10-fold increased risk of developing PDAC). From each individual, a median number of 3 serum samples (IQR 3) was collected. Ten individuals (6%) developed PDAC during 35 months of follow-up; nine (90%) of these patients carried a CDKN2A germline mutation. In PDAC cases, compared to all controls, glycosylation characteristics were increased (fucosylation, tri- and tetra-antennary structures, specific sialic linkage types), others decreased (complex-type diantennary and bisected glycans). The largest change over time was observed for tri-antennary fucosylated glycans, which were able to differentiate cases from controls with a specificity of 92%, sensitivity of 49% and accuracy of 90%. CONCLUSION: Serum N-glycan monitoring may support early detection in a pancreas surveillance program.


Asunto(s)
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Proteínas Sanguíneas/genética , Carcinoma Ductal Pancreático/diagnóstico , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Estudios Transversales , Detección Precoz del Cáncer , Predisposición Genética a la Enfermedad , Humanos , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Polisacáridos/metabolismo , Neoplasias Pancreáticas
13.
Acta Neurochir (Wien) ; 164(11): 2851-2854, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-34714431

RESUMEN

BACKGROUND: Neurohydatidosis is a rare zoonotic disease in nonendemic areas and a differential diagnosis of intracerebral cysts workup. Appropriate imaging modalities with serology are required for proper diagnosis. The gold standard surgical intervention is the Dowling-Orlando technique. METHOD: We provide a detailed description, with key surgical steps, for total excision of hydatid cysts with intact capsules by hydrodissection. We also describe the relevant surgical anatomy, with indications, limitations, and possible complications. CONCLUSION: Hydrodissection allows safe resection of hydatid cysts without further damage to the surrounding parenchyma and reduces the risk of cystic wall rupture.


Asunto(s)
Quistes del Sistema Nervioso Central , Equinococosis , Humanos , Procedimientos Neuroquirúrgicos/métodos , Equinococosis/diagnóstico por imagen , Equinococosis/cirugía , Diagnóstico Diferencial , Quistes del Sistema Nervioso Central/cirugía , Enfermedades Raras
14.
Mikrochim Acta ; 189(9): 356, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-36038741

RESUMEN

An amperometric nitrite sensor is reported based on a screen-printed carbon electrode (SPCE) modified with copper(II)-benzene-1,4-dicarboxylate (Cu-BDC) frameworks and iron(III) oxide nanoparticles (Fe2O3 NPs). First, copper(I) oxide (Cu2O) nanocubes were synthesized, followed by a solvothermal reaction between Cu2O and H2BDC to form square plate-like Cu-BDC frameworks. Then, Fe2O3 NPs were electrodeposited on Cu-BDC frameworks using a potentiostatic method. The Fe2O3@Cu-BDC nanocomposite benefits from high conductivity and large active surface area, offering excellent electrocatalytic activity for nitrite oxidation. Under optimal amperometric conditions (0.55 V vs. Ag/AgCl), the sensor has a linear range of 1 to 2000 µM with a detection limit of 0.074 µM (S/N = 3) and sensitivity of 220.59 µA mM-1 cm-2. The sensor also provides good selectivity and reproducibility (RSD = 1.91%, n = 5). Furthermore, the sensor exhibits long-term stability, retaining 91.4% of its original current after 4 weeks of storage at room temperature. Finally, assessing nitrite in tap and mineral water samples revealed that the Fe2O3@Cu-BDC/SPCE has a promising prospect in amperometric nitrite detection.


Asunto(s)
Compuestos Férricos/química , Estructuras Metalorgánicas , Nanopartículas , Carbono , Cobre , Nitritos , Óxidos , Reproducibilidad de los Resultados
15.
Fish Physiol Biochem ; 48(4): 973-989, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35781858

RESUMEN

The current study investigated how different fasting and refeeding regimes would impact Nile tilapia growth performance, histopathological examination, and gene expression of myostatin, myogenin, GH, IGF-1, and NPYa. Nile tilapia fish (n = 120) were randomly allocated into four groups, including the control group fed on a basal diet for 6 weeks (F6), group A starved for 1 week and then refed for 5 weeks (S1F5), group B starved for 2 weeks and then refed for 4 weeks (S2F4), while group C starved for 4 weeks and then refed for 2 weeks (S4F2). Fasting provoked a decrease in body weight coincided with more extended starvation periods. Also, it induced muscle and liver histological alterations; the severity was correlated with the length of fasting periods. Gene expression levels of GH, MSTN, MYOG, and NPYa were significantly increased, while IGF1 was markedly depressed in fasted fish compared to the control group. Interestingly, refeeding after well-planned short fasting period (S1F5) modulated the histopathological alterations. To some extent, these changes were restored after refeeding. Restored IGF-I and opposing fasting expression profiles of the genes mentioned above thus recovered weights almost like the control group and achieved satisfactory growth compensation. Conversely, refeeding following more extended fasting periods failed to restore body weight. In conclusion, refeeding after fasting can induce a compensatory response. Still, the restoration capacity is dependent on the length of fasting and refeeding periods through exhibiting differential morphological structure and expressions pattern for muscle and growth-related genes.


Asunto(s)
Cíclidos , Ayuno , Animales , Peso Corporal , Ayuno/fisiología , Músculos/metabolismo , ARN Mensajero/metabolismo
16.
Proc Natl Acad Sci U S A ; 115(30): E7043-E7052, 2018 07 24.
Artículo en Inglés | MEDLINE | ID: mdl-29987014

RESUMEN

Protein abnormalities in cells are the cause of major pathologies, and a number of adaptive responses have evolved to relieve the toxicity of misfolded polypeptides. To trigger these responses, cells must detect the buildup of aberrant proteins which often associate with proteasome failure, but the sensing mechanism is poorly understood. Here we demonstrate that this mechanism involves the heat shock protein 70-Bcl-2-associated athanogene 3 (Hsp70-Bag3) complex, which upon proteasome suppression responds to the accumulation of defective ribosomal products, preferentially recognizing the stalled polypeptides. Components of the ribosome quality control system LTN1 and VCP and the ribosome-associated chaperone NAC are necessary for the interaction of these species with the Hsp70-Bag3 complex. This complex regulates important signaling pathways, including the Hippo pathway effectors LATS1/2 and the p38 and JNK stress kinases. Furthermore, under proteotoxic stress Hsp70-Bag3-LATS1/2 signaling regulates protein aggregation. We established that the regulated step was the emergence and growth of abnormal protein oligomers containing only a few molecules, indicating that aggregation is regulated at very early stages. The Hsp70-Bag3 complex therefore functions as an important signaling node that senses proteotoxicity and triggers multiple pathways that control cell physiology, including activation of protein aggregation.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Reguladoras de la Apoptosis/metabolismo , Proteínas HSP70 de Choque Térmico/metabolismo , Complejos Multiproteicos/metabolismo , Agregación Patológica de Proteínas/metabolismo , Deficiencias en la Proteostasis/metabolismo , Transducción de Señal , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Reguladoras de la Apoptosis/genética , Proteínas HSP70 de Choque Térmico/genética , Células HeLa , Humanos , Complejos Multiproteicos/genética , Agregación Patológica de Proteínas/genética , Agregación Patológica de Proteínas/patología , Deficiencias en la Proteostasis/genética , Deficiencias en la Proteostasis/patología
17.
Microsc Microanal ; : 1-9, 2021 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-34024299

RESUMEN

Listeriosis is a disease that is induced by infection with the Gram-positive bacterium Listeria monocytogenes. Much is still unknown about the pathogenesis of encephalitic listeriosis. We aimed to identify the contribution of glial fibrillary acidic protein (GFAP), epithelial cadherin (E-cadherin), S100, and acute-phase proteins (APPs) in pathogenesis, clinical and preclinical diagnosis of natural cases of encephalitic listeriosis. Of 1,325 Ossimi sheep, 64 were suspected of having listeriosis from 2018 to 2020. Prospective cohort evaluation of clinical and postmortem findings was performed, in addition to bacterial isolation, the measurement of APPs in serum and cerebrospinal fluid (CSF), and the histopathological and immunohistochemical evaluation of GFAP, S100, and E-cadherin. Infected sheep showed nervous symptoms ranging from neck stretching to complete paralysis. APPs were significantly increased in the CSF of both clinically and preclinically diseased animals; however, serum APPs were only significantly increased in clinically diseased animals. Histopathological evaluation revealed microabscesses, meningoencephalitis, and perivascular cuffing of the brainstem of infected sheep. Immunohistochemical investigations revealed strong expression of GFAP and S100 in necrotic areas and negative expression of E-cadherin. The measurement of CSF APPs could be useful in the preclinical diagnosis of sheep listeriosis. GFAP and S100 proteins could be involved in the pathogenesis of listeriosis; however, E-cadherin does not appear to be involved.

18.
Cardiol Young ; 31(9): 1535-1537, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33745485

RESUMEN

Malonyl-CoA, a product of acetyl-CoA carboxylase is a metabolic intermediate in lipogenic tissues that include liver and adipose tissue, where it is involved in the de novo fatty acid synthesis and elongation. Malonyl-CoA decarboxylase (MLYCD, E.C.4.1.1.9), a 55-kDa enzyme catalyses the conversion of malonyl-CoA to acetyl-CoA and carbon dioxide, thus providing a route for disposal of malonyl-CoA from mitochondria and peroxisomes, whereas in the cytosol, the malonyl-CoA pool is regulated by the balance of MLYCD and acetyl-CoA carboxylase activities. So far, 34 cases with different MLYCD gene defects comprising point mutations, stop codons, and frameshift mutations have been reported in the literature. Here, we describe the follow-up of a patient affected by malonic aciduria upon neonatal onset. Molecular analysis showed novel homozygous mutations in the MLYCD gene. Our findings expand the number of reported cases and add a novel variant to the repertoire of MLYCD mutations.


Asunto(s)
Carboxiliasas , Errores Innatos del Metabolismo , Carboxiliasas/deficiencia , Carboxiliasas/genética , Humanos , Recién Nacido , Malonil Coenzima A , Ácido Metilmalónico , Mutación
19.
BMC Emerg Med ; 21(1): 66, 2021 05 30.
Artículo en Inglés | MEDLINE | ID: mdl-34053434

RESUMEN

BACKGROUND: Uncomplicated hyperglycaemia is a common presentation in the emergency department (ED). Rapid glucose control is associated with the risk of iatrogenic hypoglycaemia. We sought to determine the safety of a rapid glucose control protocol delivered in a 24-h emergency department observation unit (OU). METHODS: This is a retrospective chart review of patients admitted to the OU for hyperglycaemia where the assessing clinician deemed there was no other reason for medical admission apart from hyperglycaemia; and that the patient could be safely discharged provided their hyperglycaemia was adequately treated. The rapid glucose control protocol consists of 4-6 hourly glucose monitoring and insulin injections according to a sliding scale. We report the demographics, reduction in glucose values and the incidence of hypoglycaemia in the OU. We also determine the rate of discharge from OU and the rate of hospital admission at 30 days. RESULTS: We included 101 patients. The mean age was 53.5 years (95% CI 50.4-56.6) and 64% of patients were male. The mean HbA1c value was 12.8% (95% CI 12.3-13.3). The mean admission and discharge glucose values were 27.2 (95% CI 26.3-28.1) and 13.9 (95% CI 13.2-14.6) mmols/l respectively. There was no incidence of hypoglycaemia in the OU. We successfully discharged 90.1% of the patients from the OU, of which 3 (3.3%) patients were admitted to the hospital within 30 days of discharge. CONCLUSION: ED OU is a safe location to deliver effective management for patients presented with uncomplicated severe hyperglycaemia.


Asunto(s)
Glucemia , Unidades de Observación Clínica , Hiperglucemia , Automonitorización de la Glucosa Sanguínea , Humanos , Hiperglucemia/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
20.
Balkan J Med Genet ; 24(2): 49-54, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36249520

RESUMEN

Venous thromboembolism (VTE) is one of the major causes of pregnancy-related mortality and morbidity. This study aimed to determine the frequency of factor V Leiden (FVL) and prothrombin G20210A polymorphisms and measure the plasma levels of protein C (PC), protein S (PS) and antithrombin (AT) in pregnant women with VTE and healthy pregnant women. This prospective case-control study determined the frequencies of FVL G1691A and prothrombin G20210A polymorphisms and measured the plasma levels of PC, PS and AT in 198 pregnant women with VTE and 198 healthy pregnant women. Allele-specific polymerase chain reaction (ASPCR) was used to detect the FVL G1691A polymorphisms and prothrombin G20210A gene mutations. The FVL G1691A polymorphism and prothrombin G20210A gene mutations were detected only in pregnant women with VTE, with frequencies of 4.0 and 0.5%, respectively. The highest frequency of FVL G1691A polymorphism was observed in patients with deep vein thrombosis (DVT) and positively associated with contraceptive use and termination. Pregnant women with VTE had significantly lower levels of PC, PS and AT than those of controls. In conclusion, among the VTE cases, FVL G1691A polymorphism and PC, PS and AT deficiencies were the most common findings in patients presenting with DVT. Antithrombin deficiency was more common than PC and PS deficiencies. Contraceptive use, high body mass index (BMI) and termination correlated strongly with FVL G1691A polymorphism and PC and PS deficiencies in patients with VTE.

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