Deficiency of glucocerebrosidase (GBA), a lysosomal β-glucosidase, causes Gaucher disease. The enzyme hydrolyzes β-glucosidic substrates and transglucosylates cholesterol to cholesterol-β-glucoside. Here we show that recombinant human GBA also cleaves β-xylosides and transxylosylates cholesterol. The xylosyl-cholesterol formed acts as acceptor for subsequent formation of di-xylosyl-cholesterol. Common mutant forms of GBA from patients with Gaucher disease with reduced β-glucosidase activity were similarly impaired in β-xylosidase, transglucosidase and transxylosidase activities, except for a slightly reduced xylosidase/glucosidase activity ratio of N370S GBA and a slightly reduced transglucosylation/glucosidase activity ratio of D409H GBA. XylChol was found to be reduced in spleen from Gaucher disease patients. The origin of newly identified XylChol in mouse and human tissues was investigated. Cultured human cells exposed to exogenous β-xylosides generated XylChol in a manner dependent on active lysosomal GBA but not the cytosol-facing β-glucosidase GBA2. We later sought an endogenous β-xyloside acting as donor in transxylosylation reactions, identifying xylosylated ceramide (XylCer) in cells and tissues that serve as donor in the formation of XylChol. UDP-glucosylceramide synthase (GCS) was unable to synthesize XylChol but could catalyse formation of XylCer. Thus, food-derived β-D-xyloside and XylCer are potential donors for the GBA-mediated formation of XylChol in cells. The enzyme GCS produces XylCer at a low rate. Our findings point to further catalytic versatility of GBA and prompt a systematic exploration of the distribution and role of xylosylated lipids.

Adaptive thermogenesis is highly dependent on uncoupling protein 1 (UCP1), a protein expressed by thermogenic adipocytes present in brown adipose tissue (BAT) and white adipose tissue (WAT). Thermogenic capacity of human and mouse BAT can be measured by positron emission tomography-computed tomography quantifying the uptake of ¹⁸F-fluodeoxyglucose or lipid tracers. BAT activation is typically studied in response to cold exposure or treatment with β-3-adrenergic receptor agonists such as CL316,243 (CL). Currently, it is unknown whether cold-stimulated uptake of glucose or lipid tracers is a good surrogate marker of UCP1-mediated thermogenesis. In metabolic studies using radiolabeled tracers, we found that glucose uptake is increased in mildly cold-activated BAT of Ucp1^–/– versus WT mice kept at subthermoneutral temperature. Conversely, lower glucose disposal was detected after full thermogenic activation achieved by sustained cold exposure or CL treatment. In contrast, uptake of lipoprotein-derived fatty acids into chronically activated thermogenic adipose tissues was substantially increased in UCP1-deficient mice. This effect is linked to higher sympathetic tone in adipose tissues of Ucp1^–/– mice, as indicated by elevated levels of thermogenic genes in BAT and WAT. Thus, glucose and lipoprotein handling does not necessarily reflect UCP1-dependent thermogenic activity, but especially lipid uptake rather mirrors sympathetic activation of adipose tissues.

Recent efforts in gut microbiome studies have highlighted the importance of explicitly describing the ecological processes beyond correlative analysis. However, we are still at the early stage of understanding the organizational principles of the gut ecosystem, partially because of the limited information provided by currently used analytical tools in ecological modeling practices. Proteomics and metaproteomics can provide a number of insights for ecological studies, including biomass, matter and energy flow, and functional diversity. In this Mini Review, we discuss proteomics and metaproteomics-based experimental strategies that can contribute to studying the ecology, in particular at the mucosal-luminal interface (MLI) where the direct host-microbiome interaction happens. These strategies include isolation protocols for different MLI components, enrichment methods to obtain designated array of proteins, probing for specific pathways, and isotopic labeling for tracking nutrient flow. Integration of these technologies can generate spatiotemporal and site-specific biological information that supports mathematical modeling of the ecosystem at the MLI.

O-GlcNAcylation, the addition of a single N-acetylglucosamine residue to serine and threonine residues of cytoplasmic, nuclear, or mitochondrial proteins, is a widespread regulatory post-translational modification. It is involved in response to nutritional status and stress and its dysregulation is associated with diseases ranging from Alzheimer’s to diabetes.  While the modification was first detected over thirty-five years ago, research into the function of O-GlcNAcylation has accelerated dramatically in the last ten years due to the development of new enrichment and mass spectrometry techniques that facilitate its analysis.  This article summarizes methods for O-GlcNAc enrichment, key mass spectrometry instrumentation advancements, particularly those that allow modification site localization, and software tools that allow analysis of data from O-GlcNAc modified peptides.

Nov. 10—STORRS — Paige Bueckers headed to the bench for her first break of the game just 35 seconds before halftime Sunday at sold-out Gampel Pavilion. Judging by the way the UConn star almost effortlessly dominated play, Bueckers still looked fairly fresh. She already had piled up 19 points. Then again, South Florida certainly must have been tired of watching Bueckers score in a variety of ...

UConn women’s basketball freshman Sarah Strong earned the first Big East Freshman of the Week honors of her career on Monday after a pair of impressive performances in the Huskies’ Week 1 wins. Strong was the No. 1 recruit in the Class of 2024 and lived up to her elite billing with a game-high 17 points in her college debut against Boston University on Thursday. She also led the team with six ...

The precise regulation of Ca²⁺ signals plays a crucial role in the physiological functions of neurons. Here, we investigated the rapid effect of glucocorticoids on Ca²⁺ signals in cultured hippocampal neurons from both female and male rats. In cultured hippocampal neurons, glucocorticoids inhibited the spontaneous somatic Ca²⁺ spikes generated by Kv2.1-organized Ca²⁺ microdomains. Furthermore, glucocorticoids rapidly reduced the cell surface expressions of Kv2.1 and Ca_V1.2 channels in hippocampal neurons. In HEK293 cells transfected with Kv2.1 alone, glucocorticoids significantly reduced the surface expression of Kv2.1 with little effect on K⁺ currents. In HEK293 cells transfected with Ca_V1.2 alone, glucocorticoids inhibited Ca_V1.2 currents but had no effect on the cell surface expression of Ca_V1.2. Notably, in the presence of wild-type Kv2.1, glucocorticoids caused a decrease in the surface expression of Ca_V1.2 channels in HEK293 cells. However, this effect was not observed in the presence of nonclustering Kv2.1S586A mutant channels. Live-cell imaging showed that glucocorticoids rapidly decreased Kv2.1 clusters on the plasma membrane. Correspondingly, Western blot results indicated a significant increase in the cytoplasmic level of Kv2.1, suggesting the endocytosis of Kv2.1 clusters. Glucocorticoids rapidly decreased the intracellular cAMP concentration and the phosphorylation level of PKA in hippocampal neurons. The PKA inhibitor H89 mimicked the effect of glucocorticoids on Kv2.1, while the PKA agonist forskolin abrogated the effect. In conclusion, glucocorticoids rapidly suppress Ca_V1.2-mediated Ca²⁺ signals in hippocampal neurons by promoting the endocytosis of Kv2.1 channel clusters through reducing PKA activity.

New product for intensive care units automates costly and time-consuming nursing work

Title: Metronidazole (Flagyl) vs. Fluconazole (Diflucan)
Category: Medications
Created: 11/27/2018 12:00:00 AM
Last Editorial Review: 8/24/2022 12:00:00 AM

Background:

Continuous glucose monitoring (CGM) for patients with type 1 and type 2 diabetes is associated with improved clinical, behavioral, and psychosocial patient health outcomes and is part of the American Diabetes Association’s Standards of Medical Care. CGM prescription often takes place in endocrinology practices, yet 50% of adults with type 1 diabetes and 90% of all people with type 2 diabetes receive their diabetes care in primary care settings. This study examined primary care clinicians’ perceptions of barriers and resources needed to support CGM use in primary care.

Un «faucon» anti-Chine à la diplomatie, une gouverneure «tueuse de chiens» à la sécurité intérieure.

Les spectateurs québécois auront encore l’embarras du choix durant le temps des Fêtes.

For people with diabetes, glucose monitors are a valuable tool to monitor their blood sugar. The current generation of these biosensors detect glucose levels with thin, metallic filaments inserted in subcutaneous tissue, the deepest layer of the skin where most body fat is stored.

Medical technology company Biolinq is developing a new type of glucose sensor that doesn’t go deeper than the dermis, the middle layer of skin that sits above the subcutaneous tissue. The company’s “intradermal” biosensors take advantage of metabolic activity in shallower layers of skin, using an array of electrochemical microsensors to measure glucose—and other chemicals in the body—just beneath the skin’s surface.

Biolinq just concluded a pivotal clinical trial earlier this month, according to CEO Rich Yang, and the company plans to submit the device to the U.S. Food and Drug Administration for approval at the end of the year. In April, Biolinq received US $58 million in funding to support the completion of its clinical trials and subsequent submission to the FDA.

Biolinq’s glucose sensor is “the world’s first intradermal sensor that is completely autonomous,” Yang says. While other glucose monitors require a smartphone or other reader to collect and display the data, Biolinq’s includes an LED display to show when the user’s glucose is within a healthy range (indicated by a blue light) or above that range (yellow light). “We’re providing real-time feedback for people who otherwise could not see or feel their symptoms,” Yang says. (In addition to this real-time feedback, the user can also load long-term data onto a smartphone by placing it next to the sensor, like Abbott’s FreeStyle Libre, another glucose monitor.)

More than 2,000 microsensor components are etched onto each 200-millimeter silicon wafer used to manufacture the biosensors.Biolinq

Biolinq’s hope is that its approach could lead to sustainable changes in behavior on the part of the individual using the sensor. The device is intentionally placed on the upper forearm to be in plain sight, so users can receive immediate feedback without manually checking a reader. “If you drink a glass of orange juice or soda, you’ll see this go from blue to yellow,” Yang explains. That could help users better understand how their actions—such as drinking a sugary beverage—change their blood sugar and take steps to reduce that effect.

Biolinq’s device consists of an array of microneedles etched onto a silicon wafer using semiconductor manufacturing. (Other glucose sensors’ filaments are inserted with an introducer needle.) Each chip has a small 2-millimeter by 2-millimeter footprint and contains seven independent microneedles, which are coated with membranes through a process similar to electroplating in jewelry making. One challenge the industry has faced is ensuring that microsensors do not break at this small scale. The key engineering insight Biolinq introduced, Yang says, was using semiconductor manufacturing to build the biosensors. Importantly, he says, silicon “is harder than titanium and steel at this scale.”

Miniaturization allows for sensing closer to the surface of the skin, where there is a high level of metabolic activity. That makes the shallow depth ideal for monitoring glucose, as well as other important biomarkers, Yang says. Due to this versatility, combined with the use of a sensor array, the device in development can also monitor lactate, an important indicator of muscle fatigue. With the addition of a third data point, ketones (which are produced when the body burns fat), Biolinq aims to “essentially have a metabolic panel on one chip,” Yang says.

Using an array of sensors also creates redundancy, improving the reliability of the device if one sensor fails or becomes less accurate. Glucose monitors tend to drift over the course of wear, but with multiple sensors, Yang says that drift can be better managed.

One downside to the autonomous display is the drain on battery life, Yang says. The battery life limits the biosensor’s wear time to 5 days in the first-generation device. Biolinq aims to extend that to 10 days of continuous wear in its second generation, which is currently in development, by using a custom chip optimized for low-power consumption rather than off-the-shelf components.

The company has collected nearly 1 million hours of human performance data, along with comparators including commercial glucose monitors and venous blood samples, Yang says. Biolinq aims to gain FDA approval first for use in people with type 2 diabetes not using insulin and later expand to other medical indications.

This article appears in the August 2024 print issue as “Glucose Monitor Takes Page From Chipmaking.”

A glaucoma medication, methazolamide, has been found to reduce the accumulation of tau protein in zebrafish and mice, offering potential hope for treating

Wearables in Diabetes Management: Smartwatches and smart rings can accurately monitor blood glucose levels (BGLs) anywhere and anytime.

According to GlobalData, diagnosed cases of primary open-angle glaucoma (POAG), including normal-tension glaucoma (NTG), are projected to reach 10 million

New Jersey-based biopharmaceutical company, Soligenix has revealed that its developing drug has showed positive results against oral mucositis in Phase 2 clinical trial.

Japan is popular diet is bile acid diet? Bile acid is what? Bile acid is the main component of bile, can effectively break down fat. Moreover, our daily contact eucommia tea, can effectively promote the secretion of bile acid!...

UK regulator has a reporting scheme to identify safety concerns in diabetes-care devices

Molecular logic gates allow personal glucose meters to respond to many other targets

β-Glucocerebrosidase (GBA) hydrolyzes glucosylceramide (GlcCer) to generate ceramide. Previously, we demonstrated that lysosomal GBA1 and nonlysosomal GBA2 possess not only GlcCer hydrolase activity, but also transglucosylation activity to transfer the glucose residue from GlcCer to cholesterol to form β-cholesterylglucoside (β-GlcChol) in vitro. β-GlcChol is a member of sterylglycosides present in diverse species. How GBA1 and GBA2 mediate β-GlcChol metabolism in the brain is unknown. Here, we purified and characterized sterylglycosides from rodent and fish brains. Although glucose is thought to be the sole carbohydrate component of sterylglycosides in vertebrates, structural analysis of rat brain sterylglycosides revealed the presence of galactosylated cholesterol (β-GalChol), in addition to β-GlcChol. Analyses of brain tissues from GBA2-deficient mice and GBA1- and/or GBA2-deficient Japanese rice fish (Oryzias latipes) revealed that GBA1 and GBA2 are responsible for β-GlcChol degradation and formation, respectively, and that both GBA1 and GBA2 are responsible for β-GalChol formation. Liquid chromatography–tandem MS revealed that β-GlcChol and β-GalChol are present throughout development from embryo to adult in the mouse brain. We found that β-GalChol expression depends on galactosylceramide (GalCer), and developmental onset of β-GalChol biosynthesis appeared to be during myelination. We also found that β-GlcChol and β-GalChol are secreted from neurons and glial cells in association with exosomes. In vitro enzyme assays confirmed that GBA1 and GBA2 have transgalactosylation activity to transfer the galactose residue from GalCer to cholesterol to form β-GalChol. This is the first report of the existence of β-GalChol in vertebrates and how β-GlcChol and β-GalChol are formed in the brain.

Fucosylation of the innermost GlcNAc of N-glycans by fucosyltransferase 8 (FUT8) is an important step in the maturation of complex and hybrid N-glycans. This simple modification can dramatically affect the activities and half-lives of glycoproteins, effects that are relevant to understanding the invasiveness of some cancers, development of mAb therapeutics, and the etiology of a congenital glycosylation disorder. The acceptor substrate preferences of FUT8 are well-characterized and provide a framework for understanding N-glycan maturation in the Golgi; however, the structural basis of these substrate preferences and the mechanism through which catalysis is achieved remain unknown. Here we describe several structures of mouse and human FUT8 in the apo state and in complex with GDP, a mimic of the donor substrate, and with a glycopeptide acceptor substrate at 1.80–2.50 Å resolution. These structures provide insights into a unique conformational change associated with donor substrate binding, common strategies employed by fucosyltransferases to coordinate GDP, features that define acceptor substrate preferences, and a likely mechanism for enzyme catalysis. Together with molecular dynamics simulations, the structures also revealed how FUT8 dimerization plays an important role in defining the acceptor substrate-binding site. Collectively, this information significantly builds on our understanding of the core fucosylation process.

Japan is popular diet is bile acid diet? Bile acid is what? Bile acid is the main component of bile, can effectively break down fat. Moreover, our daily contact eucommia tea, can effectively promote the secretion of bile acid!...

UCM, AMUCO, CAU, BGVS, actress Tonthoi and others distribute relief items

Gluconate 5-dehydrogenase (Ga5DH; EC 1.1.1.69) from Lentibacter algarum (LaGa5DH) was recombinantly expressed in Escherichia coli and purified to homogeneity. The protein was crystallized and the crystal structure was solved at 2.1 Å resolution. The crystal belonged to the monoclinic system, with space group P1 and unit-cell parameters a = 55.42, b = 55.48, c = 79.16 Å, α = 100.51, β = 105.66, γ = 97.99°. The structure revealed LaGaDH to be a tetramer, with each subunit consisting of six α-helices and three antiparallel β-hairpins. LaGa5DH has high structural similarity to other Ga5DH proteins, demonstrating that this enzyme is highly conserved.