A casein hydrolysate protects mice against high fat diet induced hyperglycemia by attenuating NLRP3 inflammasome-mediated inflammation and improving insulin signaling.

SCOPE: Activation of the nod-like receptor protein 3 (NLRP3) inflammasome is required for IL-1ß release and is a key component of obesity-induced inflammation and insulin resistance. This study hypothesized that supplementation with a casein hydrolysate (CH) would attenuate NLRP3 inflammasome mediated IL-1ß secretion in adipose tissue (AT) and improve obesity-induced insulin resistance. METHODS AND RESULTS: J774.2 macrophages were LPS primed (10 ng/mL) and stimulated with adenosine triphosphate (5 mM) to assess NLRP3 inflammasome activity. Pretreatment with CH (1 mg/mL; 48 h) reduced caspase-1 activity and decreased IL-1ß secretion from J774.2 macrophages in vitro. 3T3-L1 adipocytes cultured with conditioned media from CH-pretreated J774.2 macrophages demonstrated increased phosphorylated (p)AKT expression and improved insulin sensitivity. C57BL/6JOLaHsd mice were fed chow or high fat diet (HFD) for 12 wk ± CH resuspended in water (0.5% w/v). CH supplementation improved glucose tolerance in HFD-fed mice as determined by glucose tolerance test. CH supplementation increased insulin-stimulated pAKT protein levels in AT, liver, and muscle after HFD. Cytokine secretion was measured from AT and isolated bone marrow macrophages cultured ex vivo. CH supplementation attenuated IL-1ß, tumor necrosis factor alpha (TNF-α) and IL-6 secretion from AT and IL-1ß, IL-18, and TNF-α from bone marrow macrophages following adenosine triphosphate stimulation ex vivo. CONCLUSION: This novel CH partially protects mice against obesity-induced hyperglycemia coincident with attenuated IL-1ß secretion and improved insulin signaling.

Tuning of nanoparticle biological functionality through controlled surface chemistry and characterisation at the bioconjugated nanoparticle surface.

We have used a silica - PEG based bionanoconjugate synthetic scheme to study the subtle connection between cell receptor specific recognition and architecture of surface functionalization chemistry. Extensive physicochemical characterization of the grafted architecture is capable of capturing significant levels of detail of both the linker and grafted organization, allowing for improved reproducibility and ultimately insight into biological functionality. Our data suggest that scaffold details, propagating PEG layer architecture effects, determine not only the rate of uptake of conjugated nanoparticles into cells but also, more significantly, the specificity of pathways via which uptake occurs.

The "sweet" side of the protein corona: effects of glycosylation on nanoparticle-cell interactions.

The significance of a protein corona on nanoparticles in modulating particle properties and their biological interactions has been widely acknowledged. The protein corona is derived from proteins in biological fluids, many of which are glycosylated. To date, the glycans on the proteins have been largely overlooked in studies of nanoparticle-cell interactions. In this study, we demonstrate that glycosylation of the protein corona plays an important role in maintaining the colloidal stability of nanoparticles and influences nanoparticle-cell interactions. The removal of glycans from the protein corona enhances cell membrane adhesion and cell uptake of nanoparticles in comparison with the fully glycosylated form, resulting in the generation of a pro-inflammatory milieu by macrophages. This study highlights that the post-translational modification of proteins can significantly impact nanoparticle-cell interactions by modulating the protein corona properties.

Nanomaterials: impact on cells and cell organelles.

Colloidal nanoparticles designed for the interactions with cells are very small, nanoscale objects usually consisting of inorganic cores and organic shells that are dispersed in a buffer or biological medium. By tuning the material properties of the nanoparticles a number of different biological applications of nanomaterials are enabled i.e. targeting, labelling, drug delivery, use as diagnostic tools or therapy. For all biological applications of nanoparticles, it is important to understand their interactions with the surrounding biological environment in order to predict their biological impact, in particular when designing the nanoparticles for diagnostic and therapeutic purpose. Due to the high surface-to-volume ratio, the surface of nanomaterials is very reactive. When exposed to biological fluids, the proteins and biomolecules present therein tend to associate with the nanoparticles' surface. This phenomenon is defined as biomolecular corona formation. The biomolecular corona plays a key role in the interaction between nanoparticles and biological systems, impacting on how these particles interact with biological systems on a cellular and molecular level. This book chapter describes the nature of the interactions at the bio-nano interface, shows the design strategy of nanoparticles for nanomedicine, and defines the concepts of biomolecular corona and biological identity of nanoparticles. Moreover, it describes the interaction of functionalised nanomaterials with cell organelles and intracellular fate of nanoparticles and it shows therapeutic application of gold nanoparticles as dose enhancers in radiotherapy.

Transferrin-functionalized nanoparticles lose their targeting capabilities when a biomolecule corona adsorbs on the surface.

Nanoparticles have been proposed as carriers for drugs, genes and therapies to treat various diseases. Many strategies have been developed to target nanomaterials to specific or over-expressed receptors in diseased cells, and these typically involve functionalizing the surface of nanoparticles with proteins, antibodies or other biomolecules. Here, we show that the targeting ability of such functionalized nanoparticles may disappear when they are placed in a biological environment. Using transferrin-conjugated nanoparticles, we found that proteins in the media can shield transferrin from binding to both its targeted receptors on cells and soluble transferrin receptors. Although nanoparticles continue to enter cells, the targeting specificity of transferrin is lost. Our results suggest that when nanoparticles are placed in a complex biological environment, interaction with other proteins in the medium and the formation of a protein corona can 'screen' the targeting molecules on the surface of nanoparticles and cause loss of specificity in targeting.

Analysis of the 5 iron golf swing when hitting for maximum distance.

Most previous research on golf swing mechanics has focused on the driver club. The aim of this study was to identify the kinematic factors that contribute to greater hitting distance when using the 5 iron club. Three-dimensional marker coordinate data were collected (250 Hz) to calculate joint kinematics at eight key swing events, while a swing analyser measured club swing and ball launch characteristics. Thirty male participants were assigned to one of two groups, based on their ball launch speed (high: 52.9 ± 2.1 m · s(-1); low: 39.9 ± 5.2 m · s(-1)). Statistical analyses were used to identify variables that differed significantly between the two groups. Results showed significant differences were evident between the two groups for club face impact point and a number of joint angles and angular velocities, with greater shoulder flexion and less left shoulder internal rotation in the backswing, greater extension angular velocity in both shoulders at early downswing, greater left shoulder adduction angular velocity at ball contact, greater hip joint movement and X Factor angle during the downswing, and greater left elbow extension early in the downswing appearing to contribute to greater hitting distance with the 5 iron club.

Positron emission tomography in the diagnosis and management of intracranial germ cell tumours.

Positron emission tomography (PET) with (18)F-fluorodeoxy-glucose indicates metabolically active tissue. When investigating enhancing intracranial tumours, we have suggested that PET positivity might suggest an intracranial germ cell tumour (IGCT). Here, we present a case with dicentric IGCT where PET was initially discordant between the lesions and where PET then became negative despite clearly aggressive clinical behaviour. A cautionary note is introduced with respect to the interpretation of negative (18)F-FDG PET when investigating enhancing intracranial lesions.

Cushing's syndrome caused by an occult source: difficulties in diagnosis and management.

BACKGROUND: A 24-year-old woman presented with a 12.5 kg weight gain over 6 months (mostly abdominal), hirsutism, acne, ankle edema, polydipsia, nocturia, back pain, pigmentation, poor libido and lightened menses to our hospital in May 1986. She had been treated for the previous 2 years with furosemide and spironolactone for peripheral edema, and had stopped the combined oral contraceptive 2 months previously. She did not take tobacco, recreational drugs or alcohol. Upon physical examination she was grossly Cushingoid with florid clinical manifestations. INVESTIGATIONS: Serum potassium and bicarbonate, circadian rhythm of cortisol, low-dose and high-dose dexamethasone suppression tests, plasma adrenocorticotropic hormone (ACTH), corticotropin releasing-hormone stimulation test, CT scan of the pituitary, plain chest radiology, CT scan of the chest and abdomen, trans-sphenoidal pituitary biopsy and histology, CT scan and MRI of the thorax, MRI of the pituitary, octreotide scintigraphy, gastroscopy, colonoscopy, gut peptides, tumor markers, urine 5-hydroxyl-indole-acetic acid, resection, histology, immunocytochemistry and in situ hybridization. DIAGNOSIS: Occult ectopic ACTH syndrome from a presumed appendiceal neuroendocrine tumor. The tumor was only identified some 20 years from initial presentation. MANAGEMENT: Adrenolytic therapy before bilateral adrenalectomy to cure Cushing's syndrome, glucocorticoid and mineralocorticoid replacement therapy, and then repeated surveillance over 20 years to locate the ectopic source of ACTH. This was finally identified by CT scan and excised at laparotomy.