The tumor suppressor gene 101 (tsg101) regulates vesicular trafficking processes in yeast and mammals. We report a novel protein, Tal (Tsg101-associated ligase), whose RING finger is necessary for multiple monoubiquitylation of Tsg101. Bivalent binding of Tsg101 to a tandem tetrapeptide motif (PTAP) and to a central region of Tal is essential for Tal-mediated ubiquitylation of Tsg101. By studying endocytosis of the epidermal growth factor receptor and egress of the human immunodeficiency virus, we conclude that Tal regulates a Tsg101-associated complex responsible for the sorting of cargo into cytoplasm-containing vesicles that bud at the multivesicular body and at the plasma membrane.[Keywords: Endocytosis; growth factor; HIV; ubiquitin; signal transduction] Supplemental material is available at http://www.genesdev.org.
Our findings are in line with emerging evidence that the spectrum of interstitial damage caused by smoke includes not only Langerhans cell hystiocytosis, respiratory bronchiolitis or desquamative interstitial pneumonia but also advanced usual interstitial pneumonitis as well. We believe that in some patients smoking plays a destructive role by a variety of mechanisms and can cause emphysema, lung fibrosis as well as pulmonary vasculopathy and hypertension. Future studies are needed to define the genetics and pathophysiology of this uncommonly reported clinical syndrome.
Our study found a 9.9% prevalence of ovarian varices in the general population. Our findings suggest that more than half (59%) the patients with ovarian varices have pelvic congestion syndrome and that most (77%) of them might benefit from ovarian vein embolization or ligation.
US performed by a skilled operator is a reliable tool for adenoma localization prior to minimally invasive parathyroidectomy. If the US findings are inconclusive, a Tc-sestamibi scan should be used. If there is a high clinical suspicion of adenoma in the presence of negative imaging studies, bilateral neck exploration should be performed.
G protein–coupled receptor (GPCR) kinases (GRKs) play a critical role in cardiac function by regulating GPCR activity. GRK2 suppresses GPCR signaling by phosphorylating and desensitizing active GPCRs, and through protein-protein interactions that uncouple GPCRs from their downstream effectors. Several GRK2 interacting partners, including Gαq, promote maladaptive cardiac hypertrophy, which leads to heart failure, a leading cause of mortality worldwide. The regulator of G protein signaling (RGS) domain of GRK2 interacts with and inhibits Gαq in vitro. We generated TgβARKrgs mice with cardiac-specific expression of the RGS domain of GRK2 and subjected these mice to pressure overload to trigger adaptive changes that lead to heart failure. Unlike their nontransgenic littermate controls, the TgβARKrgs mice exhibited less hypertrophy as indicated by reduced left ventricular wall thickness, decreased expression of genes linked to cardiac hypertrophy, and less adverse structural remodeling. The βARKrgs peptide, but not endogenous GRK2, interacted with Gαq and interfered with signaling through this G protein. These data support the development of GRK2-based therapeutic approaches to prevent hypertrophy and heart failure.
IntroductionUbiquity of Alzheimer's disease (AD) coupled with relatively ineffectual pharmacologic treatments has spurred interest in nonpharmacologic lifestyle interventions for prevention or risk reduction. However, evidence of neuroplasticity notwithstanding, there are few scientifically rigorous, ecologically relevant brain training studies focused on building cognitive reserve in middle age to protect against cognitive decline. This pilot study will examine the ability of virtual reality (VR) cognitive training to improve cognition and cerebral blood flow (CBF) in middle-aged individuals at high AD risk due to parental history.MethodsThe design is an assessor-blind, parallel group, randomized controlled trial of VR cognitive-motor training in middle-aged adults with AD family history. The experimental group will be trained with adaptive “real-world” VR tasks targeting sustained and selective attention, working memory, covert rule deduction, and planning, while walking on a treadmill. One active control group will perform the VR tasks without treadmill walking; another will walk on a treadmill while watching scientific documentaries (nonspecific cognitive stimulation). A passive (waitlist) control group will not receive training. Training sessions will be 45 minutes, twice/week for 12 weeks. Primary outcomes are global cognition and CBF (from arterial spin labeling [ASL]) at baseline, immediately after training (training gain), and 3 months post-training (maintenance gain). We aim to recruit 125 participants, including 20 passive controls and 35 in the other groups.DiscussionCurrent pharmacologic therapies are for symptomatic AD patients, whereas nonpharmacologic training is administrable before symptom onset. Emerging evidence suggests that cognitive training improves cognitive function. However, a more ecologically valid cognitive-motor VR setting that better mimics complex daily activities may augment transfer of trained skills. VR training has benefited clinical cohorts, but benefit in asymptomatic high-risk individuals is unknown. If effective, this trial may help define a prophylactic regimen for AD, adaptable for home-based application in high-risk individuals.
In experienced hands, high-resolution ultrasonography can be a cost-effective means of localizing parathyroid adenomas when unilateral neck exploration is considered the acceptable surgical approach.
The hepatic histology in nonalcoholic fatty liver disease can vary from isolated hepatic steatosis to steatohepatitis can progress to cirrhosis and liver-related death. The aim was to evaluate the use of blood serum N-glycan fingerprinting as a tool for differential diagnosis of nonalcoholic steatohepatitis from steatosis. A group of 47 patients with NAFLD was diagnosed by clinical laboratory analysis and ultrasonography, and was studied histologically using the Brunt's scoring system. The control group included 13 healthy individuals. N-glycan profiles of serum proteins were determined by DNA sequencer-based carbohydrate analytical profiling. We have found that the concentrations of two glycans (NGA2F and NA2) and their logarithm ratio of NGA2F versus NA2 (named GlycoNashTest) were associated with the degree of NASH-related fibrosis, but had no correlation with the grade of inflammation nor steatosis severity. When used to screen NAFLD patients, GlycoNashTest could identify advanced NASH-related fibrosis (F3-F4) with the diagnosis sensitivity of 89.5% and specificity of 71.4%. The serum N-glycan profile is a promising noninvasive method for detecting NASH or NASH-related fibrosis in NAFLD patients, which could be a valuable supplement to other markers currently used in diagnosis of NASH.
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