Clinical-grade human embryonic stem cell-derived mesenchymal stromal cells ameliorate diabetic retinopathy in db/db mice.

BACKGROUND AIMS: Mesenchymal stromal cells (MSCs) hold great promise in the treatment of diabetic retinopathy (DR), as evidenced by increasing preclinical and clinical studies. However, the absence of standardized and industrialized clinical-grade donor cells hampers the continued development and large-scale clinical application of MSCs-based therapies for DR. Previously, we have identified a unique population of MSCs generated from a clinical-grade human embryonic stem cell (hESC) line under Good Manufacturing Practice conditions that could be a potential source to address the issues. Here, we investigated the therapeutic potential of the clinical-grade hESC line-derived MSCs (hESC-MSCs) on db/db mice with DR. METHODS: hESC-MSCs were initially characterized by morphological assessment, flow cytometry analysis and trilineage differentiation assays. These cells (5 × 106 cells) were then transplanted intravenously into 12-week-old db/db mice via tail vein, with phosphate-buffered saline transplantation and untreated groups used as controls. The retinal alterations in neural functions and microvascular perfusions, and inflammatory responses in peripheral blood and retina were evaluated at 4 and 6 weeks after transplantation using electroretinography, optical coherence tomography angiography and flow cytometry, respectively. Body weight and fasting blood glucose (FBG) levels were also measured to investigate their systemic implications. RESULTS: Compared with controls, intravenous transplantation of hESC-MSCs could significantly: (i) enhance impaired retinal electroretinography functions (including amplitudes of a-, b-wave and oscillatory potentials) at 4 weeks after transplantation; (ii) alleviate microvascular dysfunctions, especially in the inner retina with significance (including reducing non-perfusion area and increasing vascular area density) at 4 weeks after transplantation; (iii) decrease FBG levels at 4 weeks after transplantation and induce weight loss up to 6 weeks after transplantation and (iv) increase both peripheral blood and retinal interleukin-10 levels at 4 weeks after transplantation and modulate peripheral blood inflammatory cytokines and chemokines levels, such as monocyte chemotactic protein-1, up to 6 weeks after transplantation. CONCLUSIONS: The findings of our study indicated that intravenous transplantation of hESC-MSCs ameliorated retinal neural and microvascular dysfunctions, regulated body weight and FBG and modulated peripheral blood and retinal inflammation responses in a mouse model of DR. These results suggest that hESC-MSCs could be a potentially effective clinical-grade cell source for the treatment of DR.

Food Polysaccharides and Proteins: Processing, Characterization, and Health Benefits.

Natural macromolecular substances are prevalent in the organs of plants and animals, such as polysaccharides, resins, proteins, etc [...].

Effects of three different polysaccharides on the sol gel-behavior, rheological, and structural properties of tapioca starch.

The sol-gel behavior of tapioca starch (TS) plays a crucial role in the processing and quality control of flour-based products. However, natural tapioca starch has low gel strength and poor viscosity, which tremendously limits its application. To solve this problem, this study investigated the effects of κ-carrageenan (KC), konjac gum (KGM), and Mesona chinensis Benth polysaccharide (MCP) on the pasting behavior, rheological, and structural properties of tapioca starch. KC, KGM, and MCP significantly increased the viscosity of TS. With the exception of high-concentration KGM (0.5 %), all other blending systems showed decrease in setback. This may be attributed to the stronger effect of the high-concentration KC (0.5 %) and MCP (0.5 %) functional groups interacting with starch. KC, KGM, and MCP effectively improved the dynamic modulus (G' and G") of TS gel and were effective in increasing the gel strength and hardness of TS. The FT-IR analysis indicated that the short-range order of TS was mainly influenced by polysaccharides through non-covalent bonding interactions. Furthermore, it was confirmed that three polysaccharides could form dense structures by hydrogen bonding with TS. Similarly, more stable structure and pore size were observed in the microstructure diagram.

Synergistic rosemary extract with TBHQ and citric acid improves oxidative stability and shelf life of peanut.

Lipid oxidation often accompanies the processing and storage of peanuts, which causes a serious waste of peanut resources. To solve the problem of being prone to oxidation in peanut processing, a ternary complex antioxidant based on rosemary extract (RE) was constructed to investigate its effect on the oxidative and thermal stability of peanuts, and the inhibition of peanut oxidation by compound antioxidants was revealed by dynamic Arrhenius formula and complexation theory. The results showed that there was a synergistic effect between RE and Tert-butyl hydroquinone (TBHQ), and the antioxidant effects of RE and TBHQ were 4.86 and 1.45 times higher when used in combination than when used alone, respectively. In addition, RE-TBHQ-CA (citric acid) effectively inhibited primary and secondary oxidation of peanuts with a shelf life 8.7 times longer than that of control peanuts. This study provides a novel antioxidant compounding idea, which has a positive effect on improving the quality of peanut and other nut products, prolonging the shelf life and reducing the waste of resources. PRACTICAL APPLICATION: Compounding a complex antioxidant that permits its use in peanuts. It was found that rosemary and TBHQ might have synergistic antioxidant effects. Meanwhile, this combination of RE-TBHQ-CA effectively inhibited the oxidation of peanut oils and prolonged the shelf life of peanuts. RE-TBHQ-CA is a highly efficient complex antioxidant that can reduce the amounts of antioxidants added while maintaining high antioxidant efficiency, which may be useful for the future preservation and storage of nut products as it positively affects the quality and shelf life of the product.

Effects of Premna microphylla turcz polysaccharide on rheological, gelling, and structural properties of mung bean starch and their interactions.

The aim of this study was to investigate the effects of Premna microphylla turcz polysaccharide (PMP) on the rheological, gelling, and structural properties of mung bean starch (MBS) and their potential interaction mechanism. Results showed that the addition of PMP significantly improved the pasting properties, rheological properties, water holding capacity, and thermostability of MBS. The texture tests showed a decrease in hardness, gumminess and chewiness, indicating the retrogradation of MBS was inhibited. Scanning electron microscopy (SEM) suggested the MBS-PMP composite gels expressed a denser microstructure with obvious folds and tears. Moreover, the results of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and interaction force tests revealed the main forces between MBS and PMP were hydrogen bonds and hydrophobic interactions to form composite gels with great gelling properties. These results facilitate the practical application of MBS and PMP, and provide some references for understanding the interaction mechanism between starch and polysaccharide.

Sestrin2 Protects Human Lens Epithelial Cells (HLECs) Against Apoptosis in Cataracts Formation: Interaction Between Endoplasmic Reticulum (ER) Stress and Oxidative Stress (OS) is Involved.

PURPOSE: To explore the correlation of endoplasmic reticulum stress (ERS) and oxidative stress (OS), and the protective effect of Sestrin2 (SESN2) on human lens epithelial cells (HLECs). METHODS: Tunicamycin (TM) was used to induce ERS in HLECs. 4-Phenylbutyric acid (4-PBA) was used to inhibit ERS. Eupatilin applied to HLECs as SESN2 agonist. SESN2 expression was knocked down via si-RNA in HLECs. The morphological changes of HLECs were observed by microscope. ER-tracker to evaluate ERS, ROS production assay to measure ROS, flow cytometry to calculate cell apoptosis rate. Immunofluorescence to observe Nrf2 translocation, and effects of TM or EUP on SESN2. Western blot and qPCR were used to evaluate the expression of GRP78, PERK, ATF4, CHOP, Nrf2, and SESN2 expression in HLECs with different treatment groups. RESULTS: ERS can elevate the expression of ROS and Nrf2 to induce OS. Upregulation of SESN2 was observed in ERS-mediate OS. Overexpression of SESN2 can reduce the overexpression of ERS-related protein GRP78, PERK, ATF4, proapoptotic protein CHOP, OS-related protein Nrf2, as well as ROS, and alleviate ERS injury at the same time. Whereas knockdown of SESN2 can upregulate the expression of GRP78, PERK, ATF4, CHOP, Nrf2, ROS, and deteriorate ERS damage. CONCLUSIONS: ERS can induce OS, they form a vicious cycle to induce apoptosis in HLECs, which may contribute to cataract formation. SESN2 could protect HLECs against the apoptosis by regulating the vicious cycle between ERS and OS.

Characterization of gallic acid-Chinese yam starch biodegradable film incorporated with chitosan for potential use in pork preservation.

The widely use of petroleum-based plastics causes serious environmental pollution and oil resource shortage. In this work, biodegradable films were prepared based on gallic acid (GA)-induced Chinese yam starch (YS) and chitosan (CS). The fresh-keeping effect of biodegradable films on the pork meat preservation were investigated. The prepared GA/YS/CS biodegradable films exhibited thinner thickness and better light transmittance, because CS effectively decreased the viscosity of film-forming solution and weaken its internal link structure. The SEM results and mechanical results revealed that the YS, GA, and CS had a good compatibility, GA modification and adding CS markedly improved the tensile strength of YS-based film, because the interaction between CS and starch molecular was facilitate owing to the NH3+ of CS tended to form hydrogen bonds with the hydroxyl group of starch. Sensory analysis results suggested that GA/YS/CS films can effectively improve the quality of pork during storage compared to the package of polyethylene film. In summary, the prepared GA/YS/CS film in this work had practical application potential in pork preservation due to its excellent mechanical, antibacterial, oxidation resistance properties, and the development and application of biodegradable starch film can greatly reduce the increasingly serious environmental pollution pressure.

Rheology, Texture and Swallowing Characteristics of a Texture-Modified Dysphagia Food Prepared Using Common Supplementary Materials.

A dysphagia diet is a special eating plan. The development and design of dysphagia foods should consider both swallowing safety and food nutritional qualities. In this study, the effects of four food supplements, namely vitamins, minerals, salt and sugar, on swallowing characteristics, rheological and textural properties were investigated, and a sensory evaluation of dysphagia foods made with rice starch, perilla seed oil and whey isolate protein was carried out. The results showed that all the samples belonged to foods at level 4 (pureed) in The International Dysphagia Diet Standardization Initiative (IDDSI) framework, and exhibited shear thinning behavior, which is favorable for dysphagia patients. Rheological tests showed that the viscosity of a food bolus was increased with salt and sugar (SS), while it decreased with vitamins and minerals (VM) at shear rates of 50 s-1. Both SS and VM strengthened the elastic gel system, and SS enhanced the storage modulus and loss modulus. VM increased the hardness, gumminess, chewiness and color richness, but left small residues on the spoon. SS provided better water-holding, chewiness and resilience by influencing the way molecules were connected, promoting swallowing safety. SS brought a better taste to the food bolus. Dysphagia foods with both VM and 0.5% SS had the best sensory evaluation score. This study may provide a theoretical foundation for the creation and design of new dysphagia nutritional food products.

Purple red rice bran anthocyanins reduce the digestibility of rice starch by forming V-type inclusion complexes.

Purple red rice bran, a by-product of the rice polishing process, contained abundant anthocyanins. However, most of them were discarded resulting in a waste of resources. This study investigated the effects of purple red rice bran anthocyanin extracts (PRRBAE) on the physicochemical properties and digestive properties of rice starch and its mechanism of action. Infrared spectroscopy and X-ray diffraction indicated that PRRBAE could interact with rice starch through non-covalent bonds to form intrahelical V-type complexes. The DPPH and ABTS+ assays showed that PRRBAE could confer better antioxidant activity on rice starch. In addition, the PRRBAE could increase the resistant starch content and decrease the enzyme activities by changing the tertiary and secondary structure of starch-digesting enzymes. Further, molecular docking suggested that aromatic amino acids play a key role in the interaction of starch-digesting enzymes with PRRBAE. These findings will contribute to a better understanding of the mechanism of PRRBAE reducing starch digestibility, and to the development of high value-added products and low glycemic index (GI) foods.

Fibrillation modification to improve the viscosity, emulsifying, and foaming properties of rice protein.

Fibrillation of food proteins has attracted considerable attention as it can improve and broaden the functionality of proteins. In this study, we prepared three kinds of rice protein (RP) fibrils with different structural characteristics by the regulation of NaCl and explored the effect of protein structure on viscosity, emulsifying, and foaming properties. AFM results showed fibrils formed at 0 and 100 mM NaCl were mainly in the range of 50-150 nm and 150-250 nm, respectively. Fibrils formed at 200 mM NaCl were in the range of 50-500 nm and protein fibrils longer than 500 nm increased. There was no significant difference between their height and periodicity. Fibrils formed at 0 and 100 mM NaCl were more flexible and unordered than those formed at 200 mM NaCl. The viscosity consistency index K of native RP and fibrils formed at 0, 100, and 200 mM NaCl were determined. The K value of fibrils was higher than that of native RP. The emulsifying activity index, foam capacity and foam stability were enhanced by fibrillation, while longer fibrils exhibited lower emulsifying stability index, which may be because long fibrils resulted in difficulty of cover of emulsion droplets. In summary, our work provided a valuable reference for improving the functionality of rice protein and facilitated the development of protein-based foaming agents, thickeners, and emulsifiers.