438 research outputs found

    Ubiquitin C-terminal hydrolase-activity is involved in sperm acrosomal function and anti-polyspermy defense during porcine fertilization

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    The 26S proteasome, which is a multi-subunit protease with specificity for substrate proteins that are postranslationally modified by ubiquitination, has been implicated in acrosomal function and sperm-zona pellucida (ZP) penetration during mammalian fertilization. Ubiquitin C-terminal hydrolases (UCHs) are responsible for the removal of polyubiquitin chains during substrate priming for proteasomal proteolysis. The inhibition of deubiquitination increases the rate of proteasomal proteolysis. Consequently, we have hypothesized that inhibition of sperm acrosome-borne UCHs increases the rate of sperm-ZP penetration and polyspermy during porcine in vitro fertilization (IVF). Ubiquitin aldehyde (UA), which is a specific nonpermeating UCH inhibitor, significantly (P < 0.05) increased polyspermy during porcine IVF and reduced (P < 0.05) UCH enzymatic activity measured in motile boar spermatozoa using a specific fluorometric UCH substrate, ubiquitin-AMC. Antibodies against two closely related UCHs, UCHL1 and UCHL3, detected these UCHs in the oocyte cortex and on the sperm acrosome, respectively, and increased the rate of polyspermy during IVF, consistent with the UA-induced polyspermy surge. In the oocyte, UCHL3 was primarily associated with the meiotic spindle. Sperm-borne UCHL3 was localized to the acrosomal surface and coimmunoprecipitated with a peripheral acrosomal membrane protein, spermadhesin AQN1. Recombinant UCHs, UCHL3, and isopeptidase T reduced polyspermy when added to the fertilization medium. UCHL1 was detected in the oocyte cortex but not on the sperm surface, and was partially degraded 6-8 h after fertilization. Enucleated oocyte-somatic cell electrofusion caused polarized redistribution of cortical UCHL1. We conclude that sperm-acrosomal UCHs are involved in sperm-ZP interactions and antipolyspermy defense. Modulation of UCH activity could facilitate the management of polyspermy during IVF and provide insights into male infertility

    Hepatic Oxidative Stress in Fructose-Induced Fatty Liver Is Not Caused by Sulfur Amino Acid Insufficiency

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    Fructose-sweetened liquid consumption is associated with fatty liver and oxidative stress. In rodent models of fructose-mediated fatty liver, protein consumption is decreased. Additionally, decreased sulfur amino acid intake is known to cause oxidative stress. Studies were designed to test whether oxidative stress in fructose-sweetened liquid-induced fatty liver is caused by decreased ad libitum solid food intake with associated inadequate sulfur amino acid intake. C57BL6 mice were grouped as: control (ad libitum water), fructose (ad libitum 30% fructose-sweetened liquid), glucose (ad libitum 30% glucose-sweetened water) and pair-fed (ad libitum water and sulfur amino acid intake same as the fructose group). Hepatic and plasma thiol-disulfide antioxidant status were analyzed after five weeks. Fructose- and glucose-fed mice developed fatty liver. The mitochondrial antioxidant protein, thioredoxin-2, displayed decreased abundance in the liver of fructose and glucose-fed mice compared to controls. Glutathione/glutathione disulfide redox potential (EhGSSG) and abundance of the cytoplasmic antioxidant protein, peroxiredoxin-2, were similar among groups. We conclude that both fructose and glucose-sweetened liquid consumption results in fatty liver and upregulated thioredoxin-2 expression, consistent with mitochondrial oxidative stress; however, inadequate sulfur amino acid intake was not the cause of this oxidative stress

    Mutation of FIG4 causes neurodegeneration in the pale tremor mouse and patients with CMT4J

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    Membrane-bound phosphoinositides are signalling molecules that have a key role in vesicle trafficking in eukaryotic cells(1). Proteins that bind specific phosphoinositides mediate interactions between membrane-bounded compartments whose identity is partially encoded by cytoplasmic phospholipid tags. Little is known about the localization and regulation of mammalian phosphatidylinositol-3,5-bisphosphate ( PtdIns( 3,5)P-2), a phospholipid present in small quantities that regulates membrane trafficking in the endosome - lysosome axis in yeast(2). Here we describe a multi-organ disorder with neuronal degeneration in the central nervous system, peripheral neuronopathy and diluted pigmentation in the 'pale tremor' mouse. Positional cloning identified insertion of ETn2 beta ( early transposon 2 beta)(3) into intron 18 of Fig4 (A530089I17Rik), the homologue of a yeast SAC ( suppressor of actin) domain PtdIns(3,5) P-2 5-phosphatase located in the vacuolar membrane. The abnormal concentration of PtdIns( 3,5) P2 in cultured fibroblasts from pale tremor mice demonstrates the conserved biochemical function of mammalian Fig4. The cytoplasm of fibroblasts from pale tremor mice is filled with large vacuoles that are immunoreactive for LAMP-2 (lysosomal-associated membrane protein 2), consistent with dysfunction of the late endosome - lysosome axis. Neonatal neurodegeneration in sensory and autonomic ganglia is followed by loss of neurons from layers four and five of the cortex, deep cerebellar nuclei and other localized brain regions. The sciatic nerve exhibits reduced numbers of large-diameter myelinated axons, slowed nerve conduction velocity and reduced amplitude of compound muscle action potentials. We identified pathogenic mutations of human FIG4 (KIAA0274) on chromosome 6q21 in four unrelated patients with hereditary motor and sensory neuropathy. This novel form of autosomal recessive Charcot - Marie - Tooth disorder is designated CMT4J.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62835/1/nature05876.pd

    Peer-provided psychological intervention for Syrian refugees: results of a randomised controlled trial on the effectiveness of Problem Management Plus

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    Background The mental health burden among refugees in high-income countries (HICs) is high, whereas access to mental healthcare can be limited. Objective To examine the effectiveness of a peer-provided psychological intervention (Problem Management Plus; PM+) in reducing symptoms of common mental disorders (CMDs) among Syrian refugees in the Netherlands. Methods We conducted a single-blind, randomised controlled trial among adult Syrian refugees recruited in March 2019–December 2021 (No. NTR7552). Individuals with psychological distress (Kessler Psychological Distress Scale (K10) >15) and functional impairment (WHO Disability Assessment Schedule (WHODAS 2.0) >16) were allocated to PM+ in addition to care as usual (PM+/CAU) or CAU only. Participants were reassessed at 1-week and 3-month follow-up. Primary outcome was depression/anxiety combined (Hopkins Symptom Checklist; HSCL-25) at 3-month follow-up. Secondary outcomes included depression (HSCL-25), anxiety (HSCL-25), post-traumatic stress disorder (PTSD) symptoms (PTSD Checklist for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition; PCL-5), impairment (WHODAS 2.0) and self-identified problems (PSYCHLOPS; Psychological Outcomes Profiles). Primary analysis was intention-to-treat. Findings Participants (n=206; mean age=37 years, 62% men) were randomised into PM+/CAU (n=103) or CAU (n=103). At 3-month follow-up, PM+/CAU had greater reductions on depression/anxiety relative to CAU (mean difference −0.25; 95% CI −0.385 to −0.122; p=0.0001, Cohen’s d=0.41). PM+/CAU also showed greater reductions on depression (p=0.0002, Cohen’s d=0.42), anxiety (p=0.001, Cohen’s d=0.27), PTSD symptoms (p=0.0005, Cohen’s d=0.39) and self-identified problems (p=0.03, Cohen’s d=0.26), but not on impairment (p=0.084, Cohen’s d=0.21). Conclusions PM+ effectively reduces symptoms of CMDs among Syrian refugees. A strength was high retention at follow-up. Generalisability is limited by predominantly including refugees with a resident permit. Clinical implications Peer-provided psychological interventions should be considered for scale-up in HICs

    Electrospun poly(d/l-lactide-co-l-lactide) hybrid matrix: a novel scaffold material for soft tissue engineering

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    Electrospinning is a long-known polymer processing technique that has received more interest and attention in recent years due to its versatility and potential use in the field of biomedical research. The fabrication of three-dimensional (3D) electrospun matrices for drug delivery and tissue engineering is of particular interest. In the present study, we identified optimal conditions to generate novel electrospun polymeric scaffolds composed of poly-d/l-lactide and poly-l-lactide in the ratio 50:50. Scanning electron microscopic analyses revealed that the generated poly(d/l-lactide-co-l-lactide) electrospun hybrid microfibers possessed a unique porous high surface area mimicking native extracellular matrix (ECM). To assess cytocompatibility, we isolated dermal fibroblasts from human skin biopsies. After 5 days of in vitro culture, the fibroblasts adhered, migrated and proliferated on the newly created 3D scaffolds. Our data demonstrate the applicability of electrospun poly(d/l-lactide-co-l-lactide) scaffolds to serve as substrates for regenerative medicine applications with special focus on skin tissue engineering

    Peer-provided psychological intervention for Syrian refugees: results of a randomised controlled trial on the effectiveness of Problem Management Plus

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    Background: The mental health burden among refugees in high-income countries (HICs) is high, whereas access to mental healthcare can be limited. Objective: To examine the effectiveness of a peer-provided psychological intervention (Problem Management Plus; PM+) in reducing symptoms of common mental disorders (CMDs) among Syrian refugees in the Netherlands. Methods: We conducted a single-blind, randomised controlled trial among adult Syrian refugees recruited in March 2019-December 2021 (No. NTR7552). Individuals with psychological distress (Kessler Psychological Distress Scale (K10) >15) and functional impairment (WHO Disability Assessment Schedule (WHODAS 2.0) >16) were allocated to PM+ in addition to care as usual (PM+/CAU) or CAU only. Participants were reassessed at 1-week and 3-month follow-up. Primary outcome was depression/anxiety combined (Hopkins Symptom Checklist; HSCL-25) at 3-month follow-up. Secondary outcomes included depression (HSCL-25), anxiety (HSCL-25), post-traumatic stress disorder (PTSD) symptoms (PTSD Checklist for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition; PCL-5), impairment (WHODAS 2.0) and self-identified problems (PSYCHLOPS; Psychological Outcomes Profiles). Primary analysis was intention-to-treat. Findings: Participants (n=206; mean age=37 years, 62% men) were randomised into PM+/CAU (n=103) or CAU (n=103). At 3-month follow-up, PM+/CAU had greater reductions on depression/anxiety relative to CAU (mean difference -0.25; 95% CI -0.385 to -0.122; p=0.0001, Cohen's d=0.41). PM+/CAU also showed greater reductions on depression (p=0.0002, Cohen's d=0.42), anxiety (p=0.001, Cohen's d=0.27), PTSD symptoms (p=0.0005, Cohen's d=0.39) and self-identified problems (p=0.03, Cohen's d=0.26), but not on impairment (p=0.084, Cohen's d=0.21). Conclusions: PM+ effectively reduces symptoms of CMDs among Syrian refugees. A strength was high retention at follow-up. Generalisability is limited by predominantly including refugees with a resident permit. Clinical implications: Peer-provided psychological interventions should be considered for scale-up in HICs
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