44 research outputs found

    Glycolysis Upregulation Is Neuroprotective As A Compensatory Mechanism In Als

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    Amyotrophic Lateral Sclerosis (ALS), is a fatal neurodegenerative disorder, with TDP-43 inclusions as a major pathological hallmark. Using a Drosophila model of TDP-43 proteinopathy we found significant alterations in glucose metabolism including increased pyruvate, suggesting that modulating glycolysis may be neuroprotective. Indeed, a high sugar diet improves locomotor and lifespan defects caused by TDP-43 proteinopathy in motor neurons or glia, but not muscle, suggesting that metabolic dysregulation occurs in the nervous system. Overexpressing human glucose transporter GLUT-3 in motor neurons mitigates TDP-43 dependent defects in synaptic vesicle recycling and improves locomotion. Furthermore, PFK mRNA, a key indicator of glycolysis, is upregulated in flies and patient derived iPSC motor neurons with TDP-43 pathology. Surprisingly, PFK overexpression rescues TDP-43 induced locomotor deficits. These findings from multiple ALS models show that mechanistically, glycolysis is upregulated in degenerating motor neurons as a compensatory mechanism and suggest that increased glucose availability is protective

    The Bantam microRNA Is Associated with Drosophila Fragile X Mental Retardation Protein and Regulates the Fate of Germline Stem Cells

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    Fragile X syndrome, a common form of inherited mental retardation, is caused by the loss of fragile X mental retardation protein (FMRP). We have previously demonstrated that dFmr1, the Drosophila ortholog of the fragile X mental retardation 1 gene, plays a role in the proper maintenance of germline stem cells in Drosophila ovary; however, the molecular mechanism behind this remains elusive. In this study, we used an immunoprecipitation assay to reveal that specific microRNAs (miRNAs), particularly the bantam miRNA (bantam), are physically associated with dFmrp in ovary. We show that, like dFmr1, bantam is not only required for repressing primordial germ cell differentiation, it also functions as an extrinsic factor for germline stem cell maintenance. Furthermore, we find that bantam genetically interacts with dFmr1 to regulate the fate of germline stem cells. Collectively, our results support the notion that the FMRP-mediated translation pathway functions through specific miRNAs to control stem cell regulation

    Argonaute2 Suppresses Drosophila Fragile X Expression Preventing Neurogenesis and Oogenesis Defects

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    Fragile X Syndrome is caused by the silencing of the Fragile X Mental Retardation gene (FMR1). Regulating dosage of FMR1 levels is critical for proper development and function of the nervous system and germ line, but the pathways responsible for maintaining normal expression levels are less clearly defined. Loss of Drosophila Fragile X protein (dFMR1) causes several behavioral and developmental defects in the fly, many of which are analogous to those seen in Fragile X patients. Over-expression of dFMR1 also causes specific neuronal and behavioral abnormalities. We have found that Argonaute2 (Ago2), the core component of the small interfering RNA (siRNA) pathway, regulates dfmr1 expression. Previously, the relationship between dFMR1 and Ago2 was defined by their physical interaction and co-regulation of downstream targets. We have found that Ago2 and dFMR1 are also connected through a regulatory relationship. Ago2 mediated repression of dFMR1 prevents axon growth and branching defects of the Drosophila neuromuscular junction (NMJ). Consequently, the neurogenesis defects in larvae mutant for both dfmr1 and Ago2 mirror those in dfmr1 null mutants. The Ago2 null phenotype at the NMJ is rescued in animals carrying an Ago2 genomic rescue construct. However, animals carrying a mutant Ago2 allele that produces Ago2 with significantly reduced endoribonuclease catalytic activity are normal with respect to the NMJ phenotypes examined. dFMR1 regulation by Ago2 is also observed in the germ line causing a multiple oocyte in a single egg chamber mutant phenotype. We have identified Ago2 as a regulator of dfmr1 expression and have clarified an important developmental role for Ago2 in the nervous system and germ line that requires dfmr1 function

    Worldwide Variations in Demographics, Management, and Outcomes of Acute Pancreatitis

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    Background & Aims Few studies have compared regional differences in acute pancreatitis. We analyzed data from an international registry of patients with acute pancreatitis to evaluate geographic variations in patient characteristics, management, and outcomes. Methods We collected data from the APPRENTICE registry of patients with acute pancreatitis, which obtains information from patients in Europe (6 centers), India (3 centers), Latin America (5 centers), and North America (8 centers) using standardized questionnaires. Our final analysis included 1,612 patients with acute pancreatitis (median age, 49 years; 53% male, 62% white) enrolled from August 2015 through January 2018. Results Biliary (45%) and alcoholic acute pancreatitis (21%) were the most common etiologies. Based on the revised Atlanta classification, 65% of patients developed mild disease, 23% moderate, and 12% severe. The mean age of patients in Europe (58 years) was older than mean age for all 4 regions (46 years) and a higher proportion of patients in Europe had comorbid conditions (73% vs 50% overall). The predominant etiology of acute pancreatitis in Latin America was biliary (78%), whereas alcohol-associated pancreatitis accounted for the highest proportion of acute pancreatitis cases in India (45%). Pain was managed with opioid analgesics in 93% of patients in North America versus 27% of patients in the other 3 regions. Cholecystectomies were performed at the time of hospital admission for most patients in Latin America (60% vs 15% overall). A higher proportion of European patients with severe acute pancreatitis died during the original hospital stay (44%) compared with the other 3 regions (15%). Conclusions We found significant variation in demographics, etiologies, management practices, and outcomes of acute pancreatitis worldwide

    Incidence and risk factors of oral feeding intolerance in acute pancreatitis: Results from an international, multicenter, prospective cohort study

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    Background: Inability to advance to an oral diet, or oral feeding intolerance, is a common complication in patients with acute pancreatitis associated with worse clinical outcomes. The factors related to oral feeding intolerance are not well studied. Objective: We aimed to determine the incidence and risk factors of oral feeding intolerance in acute pancreatitis. Methods: Patients were prospectively enrolled in the Acute Pancreatitis Patient Registry to Examine Novel Therapies in Clinical Experience, an international acute pancreatitis registry, between 2015 and 2018. Oral feeding intolerance was defined as worsening abdominal pain and/or vomiting after resumption of oral diet. The timing of the initial feeding attempt was stratified based on the day of hospitalization. Multivariable logistic regression was performed to assess for independent risk factors/predictors of oral feeding intolerance. Results: Of 1233 acute pancreatitis patients included in the study, 160 (13%) experienced oral feeding intolerance. The incidence of oral feeding intolerance was similar irrespective of the timing of the initial feeding attempt relative to hospital admission day (p = 0.41). Patients with oral feeding intolerance were more likely to be younger (45 vs. 50 years of age), men (61% vs. 49%), and active alcohol users (44% vs. 36%). They also had higher blood urea nitrogen (20 vs. 15 mg/dl; p < 0.001) and hematocrit levels (41.7% vs. 40.5%; p = 0.017) on admission; were more likely to have a nonbiliary acute pancreatitis etiology (69% vs. 51%), systemic inflammatory response syndrome of 2 or greater on admission (49% vs. 35%) and at 48 h (50% vs. 26%), develop pancreatic necrosis (29% vs. 13%), moderate to severe acute pancreatitis (41% vs. 24%), and have a longer hospital stay (10 vs. 6 days; all p < 0.04). The adjusted analysis showed that systemic inflammatory response syndrome of 2 or greater at 48 h (odds ratio 3.10; 95% confidence interval 1.83-5.25) and a nonbiliary acute pancreatitis etiology (odds ratio 1.65; 95% confidence interval 1.01-2.69) were independent risk factors for oral feeding intolerance. Conclusion: Oral feeding intolerance occurs in 13% of acute pancreatitis patients and is independently associated with systemic inflammatory response syndrome at 48 h and a nonbiliary etiology

    Introduction and Validation of a Novel Acute Pancreatitis Digital Tool: Interrogating Large Pooled Data From 2 Prospectively Ascertained Cohorts

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    Objectives: Acute pancreatitis (AP) is a sudden onset, rapidly evolving inflammatory response with systemic inflammation and multiorgan failure (MOF) in a subset of patients. New highly accurate clinical decision support tools are needed to allow local doctors to provide expert care. Methods: Ariel Dynamic Acute Pancreatitis Tracker (ADAPT) is a digital tool to guide physicians in ordering standard tests, evaluate test results and model progression using available data, propose emergent therapies. The accuracy of the severity score calculators was tested using 2 prospectively ascertained Acute Pancreatitis Patient Registry to Examine Novel Therapies in Clinical Experience cohorts (pilot University of Pittsburgh Medical Center, n = 163; international, n = 1544). Results: The ADAPT and post hoc expert-calculated AP severity scores were 100% concordant in both pilot and international cohorts. High-risk criteria of all 4 severity scores at admission were associated with moderately-severe or severe AP and MOF (both P < 0.0001) and prediction of no MOF was 97.8% to 98.9%. The positive predictive value for MOF was 7.5% to 14.9%. Conclusions: The ADAPT tool showed 100% accuracy with AP predictive metrics. Prospective evaluation of ADAPT features is needed to determine if additional data can accurately predict and mitigate severe AP and MOF

    Mortality in acute pancreatitis with persistent organ failure is determined by the number, type, and sequence of organ systems affected

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    Background: Persistent organ failure (POF) is the strongest determinant of mortality in acute pancreatitis (AP). There is a paucity of data regarding the impact of different POF attributes on mortality and the role of different characteristics of systemic inflammatory response syndrome (SIRS) in the risk of developing POF. Objective: We aimed to assess the association of POF dynamic features with mortality and SIRS characteristics with POF. Methods: We studied 1544 AP subjects prospectively enrolled at 22 international centers (APPRENTICE consortium). First, we estimated the association of onset, duration, and maximal score of SIRS with POF. Then, we evaluated the risk of mortality based on POF onset, duration, number, type, and sequence of organs affected. Analyses were adjusted for potential confounders. Results: 58% had SIRS, 11% developed POF, and 2.5% died. Early SIRS, persistent SIRS, and maximal SIRS score β‰₯ 3 were independently associated with higher risk of POF (p < 0.05). Mortality risk in POF was higher with two (33%, odds ratio [OR] = 10.8, 3.3-34.9) and three (48%, OR = 20.2, 5.9-68.6) organs failing, in comparison to single POF (4%). In subjects with multiple POF, mortality was higher when the cardiovascular and respiratory systems failed first or concurrently as compared to when the renal system failed first or concurrently with other organ (p < 0.05). In multivariate regression model, the number and sequence of organs affected in POF were associated with mortality (p < 0.05). Onset and duration of POF had no impact mortality. Conclusion: In AP patients with POF, the risk of mortality is influenced by the number, type, and sequence of organs affected. These results are useful for future revisions of AP severity classification systems
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