Soy protein compared with whey protein ameliorates insulin resistance by regulating lipid metabolism, AMPK/mTOR pathway and gut microbiota in high-fat diet-fed mice.

The findings of soy protein versus whey protein supplementation on glycemic regulation are inconsistent. The aim of the present study was to investigate the preventive effect of soy protein isolate (SPI) and whey protein isolate (WPI) on a high-fat diet (HFD) induced insulin resistance and its potential molecular mechanisms. Male C57BL/6J mice were randomly divided into seven groups (n = 12): normal control, HFD plus 10% SPI, HFD plus 20% SPI, HFD plus 30% SPI, HFD plus 10% WPI, HFD plus 20% WPI, and HFD plus 30% WPI. After 12 weeks of feeding, compared with the WPI groups, serum concentration of insulin, homeostasis model assessment of insulin resistance (HOMA-IR) and liver weight were significantly lower in the SPI groups. Compared with the WPI groups, the mRNA levels of CD36, SLC27A1, PPARγ and AMPKα were significantly higher, and those of LPL, SREBP1c, FASN and ACC1 were significantly lower in the liver in the SPI groups. In the liver or gastrocnemius muscle, compared with the WPI groups, the mRNA levels of GLUT4, IRS-1, PI3K and AKT were significantly higher, and those of mTOR and S6K1 were significantly lower, and the protein levels of GLUT4, p-AMPKα/AMPKα, p-PI3K/PI3K and p-AKT/AKT were significantly higher, and those of p-IRS-1Ser307/IRS-1, p-mTOR/mTOR and p-S6K1/S6K1 were significantly lower in the SPI groups. The Chao1 and ACE indices were higher, and the relative abundance of Staphylococcus and Weissella was lower in the SPI groups than those in the WPI groups. In conclusion, soy protein was more effective than whey protein in preventing IR in HFD-fed mice by regulating lipid metabolism, the AMPK/mTOR pathway, and gut microbiota.

Oyster polysaccharides relieve DSS-induced colitis via anti-inflammatory and maintaining the physiological hypoxia.

Oyster polysaccharides (OPS) possess potent anti-inflammatory properties and mediate gut microbiome. The research aimed to investigate the beneficial effect of OPS on attenuating colitis. OPS administration decreased the disease activity index and suppressed the increase in colon length. Hematoxylin and eosin staining results displayed that OPS restored the DSS-induced histopathological damage. After oral administration of OPS, myeloperoxidase activity and pro-inflammatory cytokines (TNF-α) in colitis mice were inhibited, while IL-10 was elevated. Western blotting results revealed that OPS improved the expression of tight junction proteins (ZO-1, Claudin-4, and Occludin). Additionally, OPS stabilized the expression of hypoxia-inducible factor-1α (HIF-1α) and prevented the levels of bacterial endotoxin (lipopolysaccharides). OPS activated barrier-protective genes (intestinal trefoil factor) via mediating HIF-1α. These results indicated that OPS alleviated DSS-induced colitis by inhibiting inflammation and regulating HIF-1α. OPS would be a potential candidate to alleviate DSS-induced colitis.

Whey protein and soy protein prevent obesity by upregulating uncoupling protein 1 to activate brown adipose tissue and promote white adipose tissue browning in high-fat diet-fed mice.

There are inconsistent conclusions regarding the effect of whey protein and soy protein supplementation on obesity, and the underlying mechanisms of a high-protein diet for reducing weight gain remain to be elucidated. The aim of the present study was to investigate the preventive effect of whey protein and soy protein on obesity and its possible mechanism. Eighty-four male C57BL/6J mice were randomly divided into seven dietary groups: control group (10% fat) and 6 groups fed with a high-fat diet (HFD): 10% whey protein isolate (WPI), 20% WPI, 30% WPI, 10% soy protein isolate (SPI), 20% SPI and 30% SPI for 12 weeks. Compared with the 20% SPI group, the 20% WPI group had a significantly lower body weight, serum levels of insulin, total cholesterol and leptin, weight of inguinal white adipose tissue (iWAT), and size of adipocytes in iWAT and epididymal white adipose tissue (eWAT). The body mass index (BMI) and the Lee index were significantly lower in the WPI groups than those in the SPI groups at the same protein level. The body weight, body weight gain and BMI were significantly lower with the decreasing ratio of protein to carbohydrate (P/C). Compared with the 20% SPI group, the expressions of browning-related genes such as UCP1 (uncoupling protein 1), PGC-1α, AMPKα and Cidea and the protein expression of UCP1 were significantly higher in brown adipose tissue (BAT) and iWAT in the 20% WPI group. Moreover, the expressions of lipogenesis-related genes such as SREBP1c, PPARγ, LPL and DGAT1 in BAT, iWAT and eWAT in the 10% WPI group were significantly lower compared with the 10% SPI group. In conclusion, whey protein was more effective than soy protein in preventing obesity in mice, probably by suppressing lipogenesis in adipose tissues, activating BAT and promoting the browning of iWAT. In addition, lowering the P/C ratio was beneficial for combating obesity in the context of a HFD.

One-step fabrication of graded rainbow-colored holographic photopolymer reflection gratings.

A one-step fabrication method has been developed to realize graded holographic photopolymer reflection gratings with gradually varied period in the lateral direction, leading to a rainbow-colored reflection image in the same viewing angle. This low-cost rainbow-colored filter can be integrated with detectors or imaging devices to realize compact and portable spectroscopic analyzers.

Effects of continuous haemofiltration on serum enzyme concentrations, endotoxemia, homeostasis and survival in dogs with severe heat stroke.

AIM: To examine the effectiveness of continuous haemofiltration as a treatment for severe heat stroke in dogs. METHODS: Dogs were randomly allocated to a control or continuous haemofiltration group (both n=8). Heat stroke was induced by placing anaesthetised dogs in a high temperature cabin simulator. Upon confirmation of heat stroke (rectal temperature>42 °C, mean arterial pressure (MAP) decrease>25 mmHg), dogs were removed from the chamber and continuous haemofiltration was initiated and continued for 3h for dogs in the continuous haemofiltration group. Dogs in the control group were observed at room temperature. RESULTS: Rectal temperature, haemodynamics, pH, blood gases and electrolyte concentrations rapidly returned to baseline in the continuous haemofiltration group, but not the control group. After 3h, rectal temperature was 36.68±0.51 °C in the continuous haemofiltration group and 39.83±1.10 °C in the control group (P<0.05). Continuous haemofiltration prevented endotoxin and all serum enzyme concentrations from increasing and caused malondialdehyde concentrations to decrease. After 3h, endotoxin concentrations were 0.14±0.02 EU ml(-1) in the continuous haemofiltration group and 0.23±0.05 EU ml(-1) in the control group (P=0.003), while malondialdehyde concentrations were 4.86±0.61 mmol l(-1) in the continuous haemofiltration group and 8.63±0.66 mmol l(-1) in the control group (P<0.001). Five dogs died in the control group within 3h, whereas no dogs died in the continuous haemofiltration group. CONCLUSIONS: Continuous haemofiltration rapidly reduced body temperature, normalised haemodynamics and electrolytes, improved serum enzyme concentrations and increased survival in dogs with heat stroke. Continuous haemofiltration may be an effective treatment for heat stroke.

Hybrid oxygen-responsive reflective Bragg grating platforms.

Oxygen responsive sensor platforms were fabricated by pin printing tris(4,7-diphenyl-1,10-phenanthroline)ruthenium(II) ([Ru(dpp)(3)](2+)) doped sols onto wavelength tuned reflective Bragg gratings. In an epi-luminescence configuration, these Bragg gratings (Gr) were designed to selectively reflect the O(2) responsive [Ru(dpp)(3)](2+) emission toward the detector to enhance the detected signal magnitude. The xerogel based sensors were formed onto (i) glass (XGl), (ii) directly on top of the grating (XGrGl), or (iii) on the glass substrate opposite the grating (XGlGr). The results show that all sensors exhibit linear, statistically equivalent O(2) sensitivities, and the XGrGl platform yields up to an 8-fold increase in relative detected analytical signal (RDAS) in comparison to the control (XGl) platform.

The effect of single cerebroside compounds on activation of BKCa channels.

We have previously shown that a mixture of cerebrosides obtained from dried tubers of herb Typhonium giganteum Engl. plays a neuroprotective role in the ischemic brain through its effect on activation of BK(Ca) channels. It is very curious to know whether a single pure cerebroside compound could activate the BK(Ca) channel as well. This study explored the possible effects of pure cerebroside compounds, termitomycesphins A and B, on the BK(Ca) channel activation. Both termitomycesphins A and B activated the BK(Ca) channels at micromole concentration without significant difference. Termitomycesphin A increased the single channel open probability of the BK(Ca) channels in a dose-dependent manner without modifying the single channel conductance. Termitomycesphin A activated BK(Ca) channel more efficiently when it was applied to the cytoplasmic face of the membrane, suggesting that binding site for termitomycesphin A is located at the cytoplasmic side. Termitomycesphin A shifted the voltage-dependent activation curve to less positive membrane potentials and the Ca(2+)-dependent activation curve of the channel upwards, suggesting that termitomycesphin A could activate the channels even without intracellular free Ca(2+). Furthermore, STREX-deleted BK(Ca) channels were completely insensitive to termitomycesphin A, indicating that STREX domain is required for the activation of the BK(Ca) channel. These data provide evidence that termitomycesphins are potent in stimulating the activity of the BK(Ca) channels. As BK(Ca) channels are associated with pathology of many diseases, termitomycesphins might be used as therapeutic agents for treating these diseases through its regulatory effect on the BK(Ca) channels.

Effects of cholesterol levels on the excitability of rat hippocampal neurons.

Changes in the cholesterol levels dynamically alter the microenvironment of the plasma membrane and have been shown to modify functions of ion channels. However, the cellular effect of these modifications is largely unknown. In this report, we demonstrate that cholesterol levels modulate neuronal excitability in rat hippocampal neurons. Reduction of cholesterol levels shortened the duration and increased the firing frequency and peak amplitude of action potentials, while enrichment of cholesterol reversed the effect. Furthermore, we showed that reduction of cholesterol levels increased, while enrichment of cholesterol decreased the amplitude of the delayed rectifier I(K) currents. On the other hand, reduction of cholesterol levels slowed down the inactivation of the fast transient I(A) currents, but enrichment of cholesterol had no significant effect on the I(A) currents. Besides, alteration in cholesterol levels had no significant effect on the action potential in the presence of blockers for both I(K) and I(A) currents. These observations demonstrate that cholesterol levels bi-directionally regulate the neuronal excitability mainly through modifications of the I(K) and I(A) currents, suggesting an optimum level of cholesterol for the optimum excitability of neurons. Alterations in the neuronal cholesterol levels have been associated with aging, cognitive decline, neurodegenerative diseases, etc. Therefore, our findings are important for a deeper understanding of the relationship between the cholesterol level and dysfunctions of the brain at the molecular level.