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1.
Front Immunol ; 15: 1375428, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38863697

RESUMEN

Spinal Muscular Atrophy (SMA), a neurodegenerative disorder, extends its impact beyond the nervous system. The central protein implicated in SMA, Survival Motor Neuron (SMN) protein, is ubiquitously expressed and functions in fundamental processes such as alternative splicing, translation, cytoskeletal dynamics and signaling. These processes are relevant for all cellular systems, including cells of the immune system such as macrophages. Macrophages are capable of modulating their splicing, cytoskeleton and expression profile in order to fulfil their role in tissue homeostasis and defense. However, less is known about impairment or dysfunction of macrophages lacking SMN and the subsequent impact on the immune system of SMA patients. We aimed to review the potential overlaps between SMN functions and macrophage mechanisms highlighting the need for future research, as well as the current state of research addressing the role of macrophages in SMA.


Asunto(s)
Macrófagos , Atrofia Muscular Espinal , Humanos , Macrófagos/inmunología , Macrófagos/metabolismo , Atrofia Muscular Espinal/metabolismo , Atrofia Muscular Espinal/inmunología , Animales , Proteína 1 para la Supervivencia de la Neurona Motora/genética , Proteína 1 para la Supervivencia de la Neurona Motora/metabolismo , Transducción de Señal
2.
Hum Mol Genet ; 33(15): 1367-1377, 2024 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-38704739

RESUMEN

Spinal Muscular Atrophy is caused by partial loss of survival of motoneuron (SMN) protein expression. The numerous interaction partners and mechanisms influenced by SMN loss result in a complex disease. Current treatments restore SMN protein levels to a certain extent, but do not cure all symptoms. The prolonged survival of patients creates an increasing need for a better understanding of SMA. Although many SMN-protein interactions, dysregulated pathways, and organ phenotypes are known, the connections among them remain largely unexplored. Monogenic diseases are ideal examples for the exploration of cause-and-effect relationships to create a network describing the disease-context. Machine learning tools can utilize such knowledge to analyze similarities between disease-relevant molecules and molecules not described in the disease so far. We used an artificial intelligence-based algorithm to predict new genes of interest. The transcriptional regulation of 8 out of 13 molecules selected from the predicted set were successfully validated in an SMA mouse model. This bioinformatic approach, using the given experimental knowledge for relevance predictions, enhances efficient targeted research in SMA and potentially in other disease settings.


Asunto(s)
Inteligencia Artificial , Biología Computacional , Modelos Animales de Enfermedad , Atrofia Muscular Espinal , Atrofia Muscular Espinal/genética , Atrofia Muscular Espinal/metabolismo , Animales , Ratones , Humanos , Biología Computacional/métodos , Proteína 1 para la Supervivencia de la Neurona Motora/genética , Proteína 1 para la Supervivencia de la Neurona Motora/metabolismo , Aprendizaje Automático , Algoritmos , Regulación de la Expresión Génica/genética
3.
Cancer ; 130(8): 1210-1220, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38146744

RESUMEN

BACKGROUND: Guidelines recommend the use of genomic assays such as OncotypeDx to aid in decisions regarding the use of chemotherapy for hormone receptor-positive, HER2-negative (HR+/HER2-) breast cancer. The RSClin prognostic tool integrates OncotypeDx and clinicopathologic features to predict distant recurrence and chemotherapy benefit, but further validation is needed before broad clinical adoption. METHODS: This study included patients from the National Cancer Data Base (NCDB) who were diagnosed with stage I-III HR+/HER2- breast cancer from 2010 to 2020 and received adjuvant endocrine therapy with or without chemotherapy. RSClin-predicted chemotherapy benefit was stratified into low (<3% reduction in distant recurrence), intermediate (3%-5%), and high (>5%). Cox models were used to model mortality adjusted for age, comorbidity index, insurance, and race/ethnicity. RESULTS: A total of 285,441 patients were identified for inclusion from the NCDB, with an average age of 60 years and a median follow-up of 58 months. Chemotherapy was associated with improved overall survival only for those predicted to have intermediate (adjusted hazard ratio [aHR], 0.68; 95% confidence interval [CI], 0.60-0.79) and high benefit per RSClin (aHR, 0.66; 95% CI, 0.61-0.72). Consistent benefit was seen in the subset with a low OncotypeDx score (<26) and intermediate (aHR, 0.66; 95% CI, 0.53-0.82) or high (aHR, 0.71; 95% CI, 0.58-0.86) RSClin-predicted benefit. No survival benefit with chemotherapy was seen in patients with a high OncotypeDx score (≥26) and low benefit per RSClin (aHR, 1.70; 95% CI, 0.41-6.99). CONCLUSIONS: RSClin may identify high-risk patients who benefit from treatment intensification more accurately than OncotypeDx, and further prospective study is needed.


Asunto(s)
Neoplasias de la Mama , Receptor ErbB-2 , Humanos , Persona de Mediana Edad , Femenino , Receptor ErbB-2/genética , Quimioterapia Adyuvante , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Pronóstico , Terapia Combinada , Recurrencia Local de Neoplasia/patología
4.
Saudi Med J ; 44(10): 1006-1012, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37777276

RESUMEN

OBJECTIVES: To investigate the effect of chronic hyperglycemia, hypoglycemia, and diabetic ketoacidosis (DKA) on the cognitive function of children and adolescents with type 1 diabetes mellitus (T1DM), and explore whether early disease onset correlated with cognitive impairment. METHODS: Children and adolescents with T1DM who attended the Pediatric Diabetes Clinic between January 2019 and 2020, aged between 5-14 years, with a mean of 3 glycated hemoglobin (HbA1c) readings ≥7% (53 mmol/mol) during the study period reflecting a hyperglycemic status and who agreed to participate were interviewed about their history of hypoglycemia and DKA. Participants were personally interviewed by a clinical psychologist to assess their cognitive function using a validated Arabic version of the Stanford-Binet test. RESULTS: Higher mean HbA1c levels were associated with cognitive dysfunction in three verbal domains: fluid reasoning, quantitative reasoning, and working memory. Frequent hypoglycemia negatively affected verbal knowledge. In contrast, significant hypoglycemia affected both verbal and nonverbal domains of cognition, specifically verbal and nonverbal fluid reasoning, knowledge, and working memory. Children with recurrent DKA performed below average in nonverbal fluid reasoning tasks. Additionally, moderate or severe DKA, regardless of its frequency, affected children's overall intelligence quotient. CONCLUSION: Regardless of disease onset, exposure to glycemic variability subjects children and adolescents to subtle and measurable cognitive dysfunction resulting in significant morbidity.


Asunto(s)
Diabetes Mellitus Tipo 1 , Cetoacidosis Diabética , Hiperglucemia , Hipoglucemia , Humanos , Niño , Adolescente , Preescolar , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 1/psicología , Estudios Transversales , Hemoglobina Glucada , Control Glucémico , Cognición , Hiperglucemia/psicología , Cetoacidosis Diabética/complicaciones
6.
Primates ; 64(5): 483-492, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37222867

RESUMEN

Cooperative behaviors among individuals of numerous species play a crucial role in social interactions. There is a special interest in investigating the occurrence of cooperation among apes because this knowledge could also shed light on evolutionary processes and help us understand the origin and development of cooperation in humans and primates in general. Gibbons are phylogenetically intermediate between the great apes and monkeys, and therefore represent a unique opportunity for comparisons. The aim of the present study was to discover whether or not white-handed gibbons (Hylobates lar) show cooperative behaviors. In order to test for the respective behaviors, the gibbons were presented with a commonly used experimental cooperative rope-pulling task. The gibbons in this study did not exhibit cooperative behaviors during the problem-solving task. However, prior training procedures could not be fully completed, hence this project constitutes only the onset of exploring cooperative behaviors in gibbons. Additional behavioral observations revealed that the gibbons spent significantly more time "out of arm's reach to everyone", suggesting that they are less often involved in social interactions, than other, more cooperative primates.


Asunto(s)
Hominidae , Hylobates , Animales , Humanos , Haplorrinos , Conducta Cooperativa
7.
J Am Soc Mass Spectrom ; 34(5): 857-868, 2023 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-37052511

RESUMEN

Ion mobility spectrometers (IMS) separate ions based on their ion mobility, which depends mainly on collision cross-section, mass, and charge of the ions. However, the performance is often hampered in electrospray ionization (ESI) by the appearance of multiple ion mobility peaks in the spectrum for the same analyte due to clustering and additional sodium adducts. In this work, we investigate the influence of solvents and buffer additives on the detected ion mobility peaks using ESI. Additionally, we investigate the effects of an additional chemical ionization (CI) induced by plasma ionization on the ions formed by electrospray. For this purpose, we coupled our high-resolution IMS with a resolving power of Rp = 100 to a time-of-flight mass spectrometer. Depending on the analyte and the chosen additives, the ionization process can be influenced during the electrospray process. For the herbicide isoproturon, the addition of 5 mM sodium acetate results in the formation of the sodium adduct [M + Na]+, which is reflected in the ion mobility K0 of 1.22 cm2/(V·s). In contrast, the addition of 5 mM ammonium acetate yields the protonated species [M + H]+ and a correspondingly higher K0 of 1.29 cm2/(V·s). In some cases, as with the herbicide pyrimethanil, the addition of sodium acetate can completely suppress ionizations. By carefully choosing the solvent additive for ESI-IMS or additional CI, the formation of different ion mobility peaks can be observed. This can facilitate the assignment of ions to ion mobility peaks using IMS as a compact, stand-alone instrument, e.g., for on-site analysis.

8.
Infect Dis Clin North Am ; 37(1): 123-137, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36805009

RESUMEN

Outpatient parenteral antimicrobial therapy (OPAT) for older adults is a complex process that involves multiple stakeholders and care coordination, but it is a useful and patient-centered tool with opportunities for the treatment of complicated infections, improved patient satisfaction, and reduced health-care costs. Older age should not be an exclusion for OPAT but rather prompt the OPAT provider to thoroughly evaluate candidacy and safety. Amid the on-going COVID-19 pandemic, innovations in OPAT are needed to shepherd OPAT care into a more patient-centered, thoughtful practice, whereas minimizing harm to older patients from unnecessary health-care exposure and thus health-care associated infections.


Asunto(s)
Antiinfecciosos , COVID-19 , Humanos , Anciano , Antibacterianos/uso terapéutico , Pacientes Ambulatorios , Pandemias , Atención Ambulatoria
9.
AIDS ; 37(1): 71-81, 2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-36111530

RESUMEN

OBJECTIVES: To determine whether factors associated with coronavirus disease 2019 (COVID-19) hospitalization among people with HIV (PWH) differ by age stratum. DESIGN: Retrospective cohort study. METHODS: All adult PWH with a positive SARS-CoV-2 PCR in a public safety-net health system between 1 March 2020 and 28 February 2021 and a Veterans Affairs Medical Center between 1 1 March 2020 and 15 November 2020 in Atlanta, Georgia were included. We performed multivariable logistic regression to determine demographic and clinical factors associated with COVID-19 hospitalization overall and stratified by age less than 50 and at least 50 years. RESULTS: Three hundred and sixty-five PWH (mean age 49 years, 74% cisgender male, 82% black) were included. Ninety-six percent were on antiretroviral therapy (ART), 87% had CD4 + T-cell count at least 200 cells/µl, and 89% had HIV-1 RNA less than 200 copies/ml. Overall, age [adjusted odds ratio (aOR) 95% confidence interval (CI) 1.07 (1.04-1.10)], later date of SARS-CoV-2 infection [aOR 0.997 (0.995-1.00)], heart disease [aOR 2.27 (1.06-4.85)], and history of hepatitis C virus (HCV) [aOR 2.59 (1.13-5.89)] were associated with COVID-19 hospitalization. Age-adjusted comorbidity burden was associated with 30% increased risk of hospitalization [aOR 1.30 (1.11-1.54)]. Among 168 PWH less than 50 years old, older age [aOR 1.09 (1.01-1.18)] and no ART use [aOR 40.26 (4.12-393.62)] were associated with hospitalization; age-adjusted comorbidity burden was not ( P  = 0.25). Among 197 PWH at least 50, older age [aOR 1.10 (1.04-1.16)], heart disease [aOR 2.45 (1.04-5.77)], history of HCV [aOR 3.52 (1.29-9.60)], and age-adjusted comorbidity burden [aOR 1.36 (1.12-1.66)] were associated with hospitalization. CONCLUSION: Comorbidity burden is more strongly associated with COVID-19 hospitalization among older, rather than younger, PWH. These findings may have important implications for risk-stratifying COVID-19 therapies and booster recommendations in PWH.


Asunto(s)
COVID-19 , Infecciones por VIH , Cardiopatías , Masculino , Humanos , Persona de Mediana Edad , COVID-19/epidemiología , SARS-CoV-2 , Estudios Retrospectivos , Infecciones por VIH/complicaciones , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología
10.
J Gastrointest Cancer ; 54(1): 96-103, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35028828

RESUMEN

BACKGROUND: Poor prognosis and short survival of patients harboring pancreatic cancer emerge how advanced disease it is. In a trial to achieve the earliest and most accurate diagnosis to manage this progressive disease, we proposed that using endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) with an adjuvant diagnostic immunohistochemical marker would give better diagnostic results. IMP3 has gained recently wide attention, as many studies found that IMP3 has not only diagnostic but also prognostic role in different types of malignancies. AIM OF THE STUDY: This prospective work is to assess the diagnostic role of EUS-FNA combined with the immunohistochemical expression of IMP3 on different benign and malignant pancreatic lesions. MATERIAL AND METHOD: The included pancreatic lesions (n = 140) were obtained by EUS-FNA technique and stained for IMP3 immunohistochemically. Paraffin blocks from patients who underwent excision (n = 92) or core biopsies (n = 48) were performed for confirming diagnosis. RESULTS: The combined method for diagnosis showed that IMP3 was positive in 78.7%, 91.7%, 100% PAC, mucinous neoplasm with high grade dysplasia, and IPMN with high grade dysplasia, respectively, while almost all benign lesions showed negative IMP3. Also, this method showed sensitivity (78.26%), specificity (95.83%), and accuracy (84.3%). CONCLUSION: EUS-FNA cytology with IMP3 could be a reliable diagnostic tool especially for assessment of malignant pancreatic lesions.


Asunto(s)
Biopsia por Aspiración con Aguja Fina Guiada por Ultrasonido Endoscópico , Neoplasias Pancreáticas , Humanos , Biopsia por Aspiración con Aguja Fina Guiada por Ultrasonido Endoscópico/métodos , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/patología , Estudios Prospectivos
11.
Fed Pract ; 40(9): 304-308, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38562159

RESUMEN

Background: Strategies for optimizing identification and outreach to potential candidates for monoclonal antibody (Mab) therapy for COVID-19 are not clear. Using a centralized, active surveillance system, the Atlanta Veterans Affairs Health Care System (AVAHCS) infectious disease (ID) team identified candidates for Mab infusion and provided treatment. Observations: As part of a quality improvement project from December 28, 2020, to August 31, 2021, a clinical team consisting of ID pharmacists and physicians reviewed each outpatient with a positive COVID-19 polymerase chain reaction test daily at the AVAHCS. The clinical team used Emergency Use Authorization (EUA) criteria to determine eligibility. Eligible patients were contacted on the same day of review via telephone to confirm eligibility and obtain verbal consent. Telehealth follow-up occurred on day 1 and day 7 postinfusion to assess for adverse events. In total, 2028 patients with COVID-19 were identified; 289 patients (14%) were eligible, and 132 (46%) received Mab therapy. Similar to AVAHCS demographics, a majority of those who received Mab therapy were non-Hispanic Black patients (65%). The most common comorbidities were hypertension (59%) and diabetes (37%). The median time from symptom onset to positive COVID-19 polymerase chain reaction (PCR) test result was 6 days (range, 0-9), and the median time from positive COVID-19 PCR test result to Mab infusion was 2 days (range, 0-8). Twelve patients (9%) required hospitalization for worsening COVID-19 symptoms postinfusion. No deaths occurred. Conclusions: Combining laboratory surveillance and active screening led to high uptake of Mab therapy and minimized delay from symptom onset to Mab infusion, thereby optimizing outpatient treatment of COVID-19. This approach also successfully screened and treated Black patients in the AVAHCS population.

12.
Am J Case Rep ; 23: e936313, 2022 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-35941804

RESUMEN

BACKGROUND Dieulafoy's lesion is a rare cause of severe gastrointestinal (GI) bleeding, accounting for approximately 1-2% of all cases of GI hemorrhage. Nevertheless, it can be life-threatening without prompt intervention. Dieulafoy's lesion of jejunal origin can be particularly challenging to identify due to the inability of conventional endoscopic techniques to visualize the jejunum. This case report emphasizes the difficulties in diagnosing and managing jejunal Dieulafoy's lesions and highlights the methods by which to approach refractory bleeding. CASE REPORT This is a case of a 41-year-old man with a history of uncontrolled hypertension who presented with an episode of syncope and melena associated with low hemoglobin levels requiring multiple packed red blood cell transfusions. This warranted searching for a source of bleeding within the gastrointestinal tract via 2 upper-GI endoscopies, a colonoscopy, and an abdominal computed tomography angiogram, all of which failed to localize the site of bleeding. A push enteroscopy was required to identify the lesion in the jejunum, but the bleeding was not controlled despite the application of hemoclips and epinephrine. Consequently, laparotomy and resection of the jejunal segment containing the Dieulafoy's lesion was performed and the diagnosis was established histopathologically. The patient recovered well and was discharged 4 days after the procedure. CONCLUSIONS Suspicion of a jejunal Dieulafoy's lesion should be raised if both upper- and lower-GI endoscopies yield unremarkable findings. Ideally, a push enteroscopy should be utilized diagnostically and to conservatively manage the bleeding. However, laparotomy should be considered in refractory lesions or in the presence of hemodynamic instability.


Asunto(s)
Yeyuno , Enfermedades Vasculares , Adulto , Endoscopía Gastrointestinal , Hemorragia Gastrointestinal/diagnóstico , Hemorragia Gastrointestinal/etiología , Hemorragia Gastrointestinal/cirugía , Humanos , Yeyuno/cirugía , Masculino , Melena/etiología
13.
PLoS One ; 17(7): e0271453, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35905095

RESUMEN

Selenoproteins contain the 21st amino acid, selenocysteine (Sec), which is incorporated at select UGA codons when a specialized hairpin sequence, the Sec insertion sequence (SECIS) element, is present in the 3' UTR. Aside from the SECIS, selenoprotein mRNA 3' UTRs are not conserved between different selenoproteins within a species. In contrast, the 3'-UTR of a given selenoprotein is often conserved across species, which supports the hypothesis that cis-acting elements in the 3'-UTR other than the SECIS exert post-transcriptional control on selenoprotein expression. In order to determine the function of one such SECIS context, we chose to focus on the plasma selenoprotein, SELENOP, which is required to maintain selenium homeostasis as a selenium transport protein that contains 10 Sec residues. It is unique in that its mRNA contains two SECIS elements in the context of a highly conserved 843-nucleotide 3' UTR. Here we have used RNA affinity chromatography and identified PTBP1 as the major RNA binding protein that specifically interacts with the sequence between the two SECIS elements. We then used CRISPR/Cas9 genome editing to delete two regions surrounding the first SECIS element. We found that these sequences are involved in regulating SELENOP mRNA and protein levels, which are inversely altered as a function of selenium concentrations.


Asunto(s)
Selenio , Selenocisteína , Regiones no Traducidas 3'/genética , Secuencia de Bases , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/metabolismo , Selenio/metabolismo , Selenocisteína/genética , Selenoproteína P/genética , Selenoproteína P/metabolismo , Selenoproteínas/genética , Selenoproteínas/metabolismo
14.
Open Forum Infect Dis ; 9(7): ofac215, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35794945

RESUMEN

Background: Invasive mold diseases (IMDs) cause severe illness, but public health surveillance data are lacking. We describe data collected from a laboratory-based, pilot IMD surveillance system. Methods: During 2017-2019, the Emerging Infections Program conducted active IMD surveillance at 3 Atlanta-area hospitals. We ascertained potential cases by reviewing histopathology, culture, and Aspergillus galactomannan results and classified patients as having an IMD case (based on European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group [MSG] criteria) or a non-MSG IMD case (based on the treating clinician's diagnosis and use of mold-active antifungal therapy). We described patient features and compared patients with MSG vs non-MSG IMD cases. Results: Among 304 patients with potential IMD, 104 (34.2%) met an IMD case definition (41 MSG, 63 non-MSG). The most common IMD types were invasive aspergillosis (n = 66 [63.5%]), mucormycosis (n = 8 [7.7%]), and fusariosis (n = 4 [3.8%]); the most frequently affected body sites were pulmonary (n = 66 [63.5%]), otorhinolaryngologic (n = 17 [16.3%]), and cutaneous/deep tissue (n = 9 [8.7%]). Forty-five (43.3%) IMD patients received intensive care unit-level care, and 90-day all-cause mortality was 32.7%; these outcomes did not differ significantly between MSG and non-MSG IMD patients. Conclusions: IMD patients had high mortality rates and a variety of clinical presentations. Comprehensive IMD surveillance is needed to assess emerging trends, and strict application of MSG criteria for surveillance might exclude over one-half of clinically significant IMD cases.

15.
J Biol Chem ; 298(5): 101820, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35283190

RESUMEN

The cooperation between the actin and microtubule (MT) cytoskeletons is important for cellular processes such as cell migration and muscle cell development. However, a full understanding of how this cooperation occurs has yet to be sufficiently developed. The MT plus-end tracking protein CLIP-170 has been implicated in this actin-MT coordination by associating with the actin-binding signaling protein IQGAP1 and by promoting actin polymerization through binding with formins. Thus far, the interactions of CLIP-170 with actin were assumed to be indirect. Here, we demonstrate using high-speed cosedimentation assays that CLIP-170 can bind to filamentous actin (F-actin) directly. We found that the affinity of this binding is relatively weak but strong enough to be significant in the actin-rich cortex, where actin concentrations can be extremely high. Using CLIP-170 fragments and mutants, we show that the direct CLIP-170-F-actin interaction is independent of the FEED domain, the region that mediates formin-dependent actin polymerization, and that the CLIP-170 F-actin-binding region overlaps with the MT-binding region. Consistent with these observations, in vitro competition assays indicate that CLIP-170-F-actin and CLIP-170-MT interactions are mutually exclusive. Taken together, these observations lead us to speculate that direct CLIP-170-F-actin interactions may function to reduce the stability of MTs in actin-rich regions of the cell, as previously proposed for MT end-binding protein 1.


Asunto(s)
Actinas , Microtúbulos , Actinas/metabolismo , Forminas , Proteínas de Microfilamentos/genética , Proteínas de Microfilamentos/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Microtúbulos/metabolismo , Proteínas de Neoplasias/metabolismo
16.
Life Sci Alliance ; 5(5)2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35210313

RESUMEN

The dietary requirement for selenium is based on its incorporation into selenoproteins, which contain the amino acid selenocysteine (Sec). The Sec insertion sequence (SECIS) is an RNA structure found in the 3' UTR of all selenoprotein mRNAs, and it is required to convert in-frame UGA codons from termination to Sec-incorporating codons. SECIS-binding protein 2 (Sbp2) is required for Sec incorporation, but its paralogue, SECIS-binding protein 2-like (Secisbp2l), while conserved, has no known function. Here we determined the relative roles of Sbp2 and Secisbp2l by introducing CRISPR mutations in both genes in zebrafish. By monitoring selenoprotein synthesis with 75Se labeling during embryogenesis, we found that sbp2 -/- embryos still make a select subset of selenoproteins but secisbp2l -/- embryos retain the full complement. Abrogation of both genes completely prevents selenoprotein synthesis and juveniles die at 14 days post fertilization. Embryos lacking Sbp2 are sensitive to oxidative stress and express the stress marker Vtg1. We propose a model where Secisbp2l is required to promote essential selenoprotein synthesis when Sbp2 activity is compromised.


Asunto(s)
Proteínas de Unión al ARN , Pez Cebra , Regiones no Traducidas 3' , Animales , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Selenocisteína/genética , Selenocisteína/metabolismo , Selenoproteínas/genética , Selenoproteínas/metabolismo , Pez Cebra/genética
17.
PLoS One ; 16(12): e0260401, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34890409

RESUMEN

Proper regulation of microtubule (MT) dynamics is critical for cellular processes including cell division and intracellular transport. Plus-end tracking proteins (+TIPs) dynamically track growing MTs and play a key role in MT regulation. +TIPs participate in a complex web of intra- and inter- molecular interactions known as the +TIP network. Hypotheses addressing the purpose of +TIP:+TIP interactions include relieving +TIP autoinhibition and localizing MT regulators to growing MT ends. In addition, we have proposed that the web of +TIP:+TIP interactions has a physical purpose: creating a dynamic scaffold that constrains the structural fluctuations of the fragile MT tip and thus acts as a polymerization chaperone. Here we examine the possibility that this proposed scaffold is a biomolecular condensate (i.e., liquid droplet). Many animal +TIP network proteins are multivalent and have intrinsically disordered regions, features commonly found in biomolecular condensates. Moreover, previous studies have shown that overexpression of the +TIP CLIP-170 induces large "patch" structures containing CLIP-170 and other +TIPs; we hypothesized that these structures might be biomolecular condensates. To test this hypothesis, we used video microscopy, immunofluorescence staining, and Fluorescence Recovery After Photobleaching (FRAP). Our data show that the CLIP-170-induced patches have hallmarks indicative of a biomolecular condensate, one that contains +TIP proteins and excludes other known condensate markers. Moreover, bioinformatic studies demonstrate that the presence of intrinsically disordered regions is conserved in key +TIPs, implying that these regions are functionally significant. Together, these results indicate that the CLIP-170 induced patches in cells are phase-separated liquid condensates and raise the possibility that the endogenous +TIP network might form a liquid droplet at MT ends or other +TIP locations.


Asunto(s)
Condensados Biomoleculares/metabolismo , Proteínas Portadoras/química , Proteínas Asociadas a Microtúbulos/química , Microtúbulos/metabolismo , Proteínas de Neoplasias/química , Animales , Sitios de Unión , Transporte Biológico , Biología Computacional , Ratones , Proteínas Asociadas a Microtúbulos/genética , Proteínas Asociadas a Microtúbulos/metabolismo , Chaperonas Moleculares/química , Células 3T3 NIH , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Transición de Fase , Unión Proteica , Conformación Proteica
18.
Anal Chem ; 93(40): 13615-13623, 2021 10 12.
Artículo en Inglés | MEDLINE | ID: mdl-34592821

RESUMEN

We introduce the coupling of droplet microfluidics and ion mobility spectrometry (IMS) to address the challenges of label-free and chemical-specific detection of compounds in individual droplets. In analogy to the established use of mass spectrometry, droplet-IMS coupling can be also achieved via electrospray ionization but with significantly less instrumental effort. Because IMS instruments do not require high-vacuum systems, they are very compact, cost-effective, and robust, making them an ideal candidate as a chemical-specific end-of-line detector for segmented flow experiments. Herein, we demonstrate the successful coupling of droplet microfluidics with a custom-built high-resolution drift tube IMS system for monitoring chemical reactions in nL-sized droplets in an oil phase. The analytes contained in each droplet were assigned according to their characteristic ion mobility with limit of detections down to 200 nM to 1 µM and droplet frequencies ranging from 0.1 to 0.5 Hz. Using a custom sheath flow electrospray interface, we have further achieved the chemical-specific monitoring of a biochemical transformation catalyzed by a few hundred yeast cells, at single droplet level.


Asunto(s)
Espectrometría de Movilidad Iónica , Microfluídica , Espectrometría de Masas
19.
Tob Use Insights ; 14: 1179173X211006652, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33854394

RESUMEN

BACKGROUND: The prevalence of smoking has increased in recent years in Saudi Arabia. Our objectives were to determine the factors affecting smoking among physicians and to assess physicians' quitting behavior. METHODS: A cross-sectional study was carried out at 3 district hospitals in Riyadh, Saudi Arabia. It involved physicians with different levels of experience and different specialties. They were asked to complete a self-administered questionnaire adapted from validated tools. The questionnaire addressed sociodemographic data, lifestyle, and work-related factors as well as smoking cessation and relapse. SPSS statistical software was used for the statistical analysis. RESULTS: The study included 290 physicians, of whom 91% were Saudi and 59.7% were male. About 55.2% were younger than age of 30. Overall, 34.8% were smokers. The following factors had a significant association with smoking: a smoking family member/friend, resident occupational status, medical specialty, and frequent on-call duties increased the likelihood of smoking. One-third of the physicians (31.6%) who tried to quit smoking reported seeking information on social media, television, and/or the internet. The most common causes of relapse were social stress and withdrawal symptoms, while the least common was work-related stress. CONCLUSIONS: Smoking was highly prevalent among physicians. The likelihood of smoking was higher in, residents, medical specialists and those with a high number of on-call duties. Moreover, this study described cessation practices in this group, which might be considered when designing and improving counseling programs for physicians who smoke.

20.
Cells ; 9(11)2020 11 03.
Artículo en Inglés | MEDLINE | ID: mdl-33153033

RESUMEN

Spinal Muscular Atrophy (SMA) is a neuromuscular disease caused by decreased levels of the survival of motoneuron (SMN) protein. Post-translational mechanisms for regulation of its stability are still elusive. Thus, we aimed to identify regulatory phosphorylation sites that modulate function and stability. Our results show that SMN residues S290 and S292 are phosphorylated, of which SMN pS290 has a detrimental effect on protein stability and nuclear localization. Furthermore, we propose that phosphatase and tensin homolog (PTEN), a novel phosphatase for SMN, counteracts this effect. In light of recent advancements in SMA therapies, a significant need for additional approaches has become apparent. Our study demonstrates S290 as a novel molecular target site to increase the stability of SMN. Characterization of relevant kinases and phosphatases provides not only a new understanding of SMN function, but also constitutes a novel strategy for combinatorial therapeutic approaches to increase the level of SMN in SMA.


Asunto(s)
Aminoácidos/metabolismo , Fosfohidrolasa PTEN/metabolismo , Proteína 1 para la Supervivencia de la Neurona Motora/química , Proteína 1 para la Supervivencia de la Neurona Motora/metabolismo , Secuencia de Aminoácidos , Animales , Caenorhabditis elegans , Línea Celular Tumoral , Núcleo Celular/metabolismo , Técnicas de Silenciamiento del Gen , Humanos , Ratones , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Fosforilación , Fosfoserina/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Unión Proteica , Estabilidad Proteica , Proteolisis , Relación Estructura-Actividad
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