Caffeine has been proposed to have several beneficial effects on obesity and its related metabolic diseases; however, how caffeine affects adipocyte differentiation has not been elucidated. In this ...study, we demonstrated that caffeine suppressed 3T3-L1 adipocyte differentiation and inhibited the expression of CCAAT/enhancer binding protein (C/EBP)α and peroxisome proliferator-activated receptor (PPAR)γ, two main adipogenic transcription factors. Anti-adipogenic markers, such as preadipocyte secreted factor (Pref)-1 and Krüppel-like factor 2, remained to be expressed in the presence of caffeine. Furthermore, 3T3-L1 cells failed to undergo typical mitotic clonal expansion in the presence of caffeine. Investigation of hormonal signaling revealed that caffeine inhibited the activation of AKT and glycogen synthase kinase (GSK) 3 in a dose-dependent manner, but not extracellular signal-regulated kinase (ERK). Our data show that caffeine is an anti-adipogenic bioactive compound involved in the modulation of mitotic clonal expansion during adipocyte differentiation through the AKT/GSK3 pathway. BMB Reports 2016; 49(2): 111-115.
Loss of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) activity in mammals results in severe combined immuno-deficiency (SCID). This SCID phenotype has been postulated to be due solely to ...the function of DNA-PKcs in V(D)J recombination, a process critical for lymphocyte maturation. However; we show that DNA-PKcs is required for IL-2 production via regulation of the calcineurin signaling pathway. Reducing DNA-PKcs activity in activated T cells either by shRNA or an inhibitor significantly reduced IL-2 production by blocking calcineurin activity and the translocation of NFAT into the nucleus. Additionally, we show that DNA-PKcs exerts its effect on calcineurin by altering the expression of the endogenous calcineurin inhibitor Cabin1 through activation of the kinase CHK2, a known Cabin1 regulator. The discovery of DNA-PKcs as a potent regulator of IL-2 production will drive continued investigation of small molecule inhibition of this enzyme within the clinic.
Hypoxia influences many key biological functions. In cancer, it is generally believed that hypoxic condition is generated deep inside the tumor because of the lack of oxygen supply. However, ...consumption of oxygen by cancer should be one of the key means of regulating oxygen concentration to induce hypoxia but has not been well studied. Here, we provide direct evidence of the mitochondrial role in the induction of intracellular hypoxia. We used Acetylacetonatobis 2-(2'-benzothienyl) pyridinato-kN, kC3' iridium (III) (BTP), a novel oxygen sensor, to detect intracellular hypoxia in living cells via microscopy. The well-differentiated cancer cell lines, LNCaP and MCF-7, showed intracellular hypoxia without exogenous hypoxia in an open environment. This may be caused by high oxygen consumption, low oxygen diffusion in water, and low oxygen incorporation to the cells. In contrast, the poorly-differentiated cancer cell lines: PC-3 and MDAMB231 exhibited intracellular normoxia by low oxygen consumption. The specific complex I inhibitor, rotenone, and the reduction of mitochondrial DNA (mtDNA) content reduced intracellular hypoxia, indicating that intracellular oxygen concentration is regulated by the consumption of oxygen by mitochondria. HIF-1α was activated in endogenously hypoxic LNCaP and the activation was dependent on mitochondrial respiratory function. Intracellular hypoxic status is regulated by glucose by parabolic dose response. The low concentration of glucose (0.045 mg/ml) induced strongest intracellular hypoxia possibly because of the Crabtree effect. Addition of FCS to the media induced intracellular hypoxia in LNCaP, and this effect was partially mimicked by an androgen analog, R1881, and inhibited by the anti-androgen, flutamide. These results indicate that mitochondrial respiratory function determines intracellular hypoxic status and may regulate oxygen-dependent biological functions.
Hard coral cover (HCC) in the Philippines has been declining over the past decades. Restoration practices that utilize “gardening” corals of opportunity (COPs) are actively being adopted throughout ...the country. However, the use of COPs in coral gardening has not yet been examined in terms of its effectiveness in addressing nationwide‐scale reef decline. The feasibility of using COPs for coral gardening was determined through a spreadsheet model that derives COP numbers needed to increase HCC in a reef. The model showed that 280,112 COPs of 5‐cm radius need to be transplanted to increase HCC in a hectare of reef from 0% to 22%, the current national average. Annual COP mortality must be less than 31.5% to achieve an increase in HCC above 22% over a span of 10 years following a gardening effort. Actual counts and generic composition of available COPs were recorded from transects in 20 reef stations across three locations in the Philippines (Lian, Luzon; Lubang Island; and Balabac, Palawan). Natural COP densities suggest that large areas of healthy reefs must be searched to obtain enough COPs for an effective gardening effort. Furthermore, the COPs measured in Lian were below the recommended fragment size for transplantation, thus needing nursery rearing to attain the 5‐cm radius prescribed for increased probability of transplant survivorship. These findings indicate that applying coral gardening at a nationwide scale is not likely to be feasible, effective, or sustainable.
Glucocorticoids are associated with obesity, but the underlying mechanism by which they function remains poorly understood. Previously, we showed that small G protein Dexras1 is expressed by ...glucocorticoids and leads to adipocyte differentiation. In this study, we explored the mechanism by which Dexras1 mediates adipogenesis and show a link to the insulin-like growth factor-1 (IGF-1) signaling pathway. Without Dexras1, the activation of MAPK and subsequent phosphorylation of CCAAT/enhancer binding protein β (C/EBPβ) is abolished, thereby inhibiting mitotic clonal expansion and further adipocyte differentiation. Dexras1 translocates to the plasma membrane upon insulin or IGF-1 treatment, for which the unique C-terminal domain (amino acids 223-276) is essential. Dexras1-dependent MAPK activation is selectively involved in the IGF-1 signaling, because another Ras protein, H-ras localized to the plasma membrane independently of insulin treatment. Moreover, neither epidermal growth factor nor other cell types shows Dexras1-dependent MAPK activation, indicating the importance of Dexras1 in IGF-1 signaling in adipogenesis. Dexras1 interacts with Shc and Raf, indicating that Dexras1-induced activation of MAPK is largely dependent on the Shc-Grb2-Raf complex. These results suggest that Dexras1 is a critical mediator of the IGF-1 signal to activate MAPK, linking glucocorticoid signaling to IGF-1 signaling in adipogenesis.
Milk fat globule membrane (MFGM) is a lipid carrier in mammals including humans that consists mainly of polar lipids, like phospholipids and glycolipids. In this study, a process to enrich polar ...lipids in commercial butter and whey powder, including polar lipids of MFGM, was developed. WPC (whey protein concentrate) 60 was selected as the most suitable raw material based on the yield, phospholipid, protein, and lactose content of the polar lipid fraction obtained by ethanol extraction of two WPC (WPC60 and WPC70) and two buttermilk (A and B). After fractionation under optimum conditions, the polar-lipid enriched fraction from WPC60 contained 38.56% phospholipids. The content of glycolipids, cerebroside, lactosylceramide, ganglioside GM3, ganglioside GD3, was 0.97%, 0.55%, 0.09%, and 0.14%, respectively. Rancimat results showed that the oxidation stability of fish oil increased with an increase in the polar-lipid fraction by more than 30 times. In addition, the secretion of IL-6 and TNF-α decreased in a concentration-dependent manner after treatment of RAW 264.7 cells with 0.1 to 100 ppm of the polar lipid fraction. In this study, polar lipid concentrates with antioxidant and anti-inflammatory activity, were prepared from milk processing by-products. The MFGM polar lipid concentrates made from by-products are not only additives for infants, but are also likely to be used as antioxidants in cooking oils and as active ingredients for functional foods.
Low‐dielectric‐constant periodic mesoporous organosilica thin films are fabricated by vacuum‐assisted aerosol deposition, a vapor‐phase delivery technique favored by the semiconductor industry. The ...mesostructured films possess a combination of dielectric and mechanical properties that make them an ideal candidate for insulating materials on semiconductor chips (see image).
Abstract Background Children with microtia complain of severe postoperative pain during early postoperative days after rib cartilage harvest for auricular reconstruction. The purpose of this study ...was to evaluate the effects of preventive donor site wound analgesia by intercostal nerve block (ICNB) and catheter-based infusion of local analgesics on postoperative pain after rib cartilage graft for auricular reconstruction in children with microtia. Methods In this prospective randomized study, 66 children underwent postoperative pain control using either preventive ICNB followed by catheter based infusion (33 patients, study group) or intravenous analgesia alone (33 patients, control group). ICNB was performed under direct vision by the surgeon by injecting 0.5% bupivacaine into each of the three intercostal spaces before perichondrial dissection. Catheters were placed in three subchondral spaces before wound closure, and 0.5% bupivacaine was infused every 12 hours for 48 hours postoperatively. Pain degrees were recorded every four hours during the first 48 postoperative hours using a visual analogue scale (VAS). Results The study group showed significantly lower mean pain scores of the chest at rest (3.7 vs. 5.1, p = 0.001), the chest during coughing (4.3 vs. 5.8, p = 0.006), and the ear (3.0 vs. 4.1, p = 0.001). The amount of rescue intravenous ketorolac use was smaller in the study group ( p = 0.026). No side effects related to the intervention were noted. Conclusions Preventive ICNB followed by catheter based infusion is effective and safe in postoperative pain relief in rib cartilage graft for auricular reconstruction.
Materials under viscoplastic deformation at ultrahigh strain rates (>106s−1) often demonstrate anomalous properties due to thermal and stress localization. As a model system, thermoplastic ...nano-cellular material (NCM) coatings are produced by consolidating microscopic polystyrene shells of nanoscale thin walls using self-limiting electrospray deposition. As both the spatial and temporal characterization scales are crucial, the NCMs are characterized by laser-induced projectile impact test (LIPIT) for understanding their ultrahigh-strain-rate plasticity originating from their porous structures. In LIPIT, supersonic collisions of rigid microspheres create these extreme physical conditions at the microscale. Viscoplastic vertical densification without the Poisson effect is the foremost process in the ultrahigh-rate plastic deformation of the NCM coatings. When the extreme nature of the viscoplastic deformation is promoted by increasing the porosity and reducing the thickness of NCM coatings, significantly more energy dissipation is observed without more material due to the localized feedback between adiabatic plastic deformation and thermal softening. Despite the stochastic and isotropic structural architecture of the NCM, the specific energy absorption of the NCM is high as 170 kJ/kg at the deformation speed of 400 m/s, which is attributed to the nanoscale effects from the thin wall thickness of NCM coatings. The findings suggest the general design rule for enhancing specific energy absorption by creating viscoplastic hot spots under impact loading.
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