Casein kinase-2 inhibition promotes retinal ganglion cell survival after acute intraocular pressure elevation

Intraocular pressure elevation can induce retinal ganglion cell death and is a clinically reversible risk factor for glaucoma,the leading cause of irreversible blindness.We previously demonstrated that casein kinase-2 inhibition can promote retinal ganglion cell survival and axonal regeneration in rats after optic nerve injury.To investigate the underlying mechanism,in the current study we increased the intraocular pressure of adult rats to 75 mmHg for 2 hours and then administered a casein kinase-2 inhibitor(4,5,6,7-tetrabromo-2-azabenzimidazole or 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole)by intravitreal injection.We found that intravitreal injection of 4,5,6,7-tetrabromo-2-azabenzimidazole or 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole promoted retinal ganglion cell survival and reduced the number of infiltrating macrophages.Transcriptomic analysis showed that the mitogen activated protein kinase signaling pathway was involved in the response to intraocular pressure elevation but was not modulated by the casein kinase-2 inhibitors.Furthermore,casein kinase-2 inhibition downregulated the expression of genes(Cck,Htrsa,Nef1,Htrlb,Prph,Chat,Slc18a3,Slc5a7,Scn1b,Crybb2,Tsga10ip,and Vstm21)involved in intraocular pressure elevation.Our data indicate that inhibition of casein kinase-2 can enhance retinal ganglion cell survival in rats after acute intraocular pressure elevation via macrophage inactivation.

Colloidal nanoparticles prepared from zein and casein:interactions,characterizations and emerging food applications

Protein colloidal nanoparticles(NPs)are ubiquitous present in nature and function as building blocks with multiple functions in both food formulations and biological processes.Food scientists are inspired by naturally occurring proteins to induce self-assembly behavior of protein by manipulating environmental parameters,providing opportunities to construct special and expected NPs.Zein and casein,the main proteins derived from corn and milk,are two examples of the most prevalently studied food proteins for nanoarchitectures in recent years.In this article,the compositions,structures,and physicochemical properties of these two proteins and casein derivatives are summarized as well as their interactions and characterizations.Strategies to fabricate zein-sodium caseinate based NPs are critically highlighted and illustrated.Particularly,applications such as encapsulation and delivery of bioactive compounds,producing food packaging for enhanced antioxidative and antimicrobial effects,and stabilization of emulsions to achieve fat replacement.Due to the imperative role of food proteins in diet composition,this review not only provides cutting-edge knowledge for nanoparticle construction but also opens new avenues for efficient utilization and exploitation of food proteins.

Au@Ag-labeled SERS lateral flow assay for highly sensitive detection of allergens in milk

Casein andα-lactalbumin(α-LA)are the main allergens in cow's milk,which can affect the skin,respiratory system,and gastrointestinal tract,even cause anaphylactic shock.Developing a rapid and sensitive detection method of casein andα-LA is still pursued.Herein,a surface-enhanced Raman scattering based lateral flow assay(SERS-LFA)method for rapid and highly sensitive detection of milk allergens in food was established for effectively preventing allergic symptoms.Gold@silver nanoparticles(Au@Ag NPs)were synthesized as SERS active substrate to prepare the antibody-modified SERS Probe and SERS-LFA strips toward casein andα-LA were assembled according to the sandwich mode.The detection results were calculated according to colorimetric and Raman signal.The introduction of SRES signal significantly increased the sensitivity of detection with the limit of detection(LOD)of 0.19 ng/mL and 1.74 pg/mL,and exhibited an excellent linear relationship within the range of 0.55-791.50 ng/mL and 0.1 pg/mL-100.0 ng/mL for casein andα-LA,respectively.Furthermore,SERS-LFA strips was highly specific with the recovery rates for corresponding80.36%-105.12%and 85.73%-118.22%for casein andα-LA,respectively.Therefore,the SERS-LFA could be in great potential to develop a unique allergen detection method.

Synthesis and Characterization of a Polymeric Material Blended to Bone Forming Elements

A synthetizing material blended with two distinct proteins (collagen and casein) and mineral mixture, was developed in order to evaluate their properties suitable for possible applications in the biomedical such as inducing the regeneration of damaged bone, either due to an accident or illness. Samples were evaluated by 1) Mechanical properties tests under the bending, 2) Scanning electronic microscopy and 3) Infrared spectroscopy were carried out. The results showed that the developed material has breaking strength and structure characteristics associated with the protein used in their composition. This fact suggests that the used protein determines the resistance of the material, in such a way according to the required use, being able to choose appropriate strength and duration either short or long time. The material composition for specific use, in order to find the most suitable mixture for bone replacement, or induce bone recovery, according to the required properties similar to those of damaged living tissue.

Casein kinase 2 interacts with and phosphorylates ataxin-3

Objective Machado-Joseph disease （MJD）/Spinocerebellar ataxia type 3 （SCA3） is an autosomal dominant neurodegenerative disorder caused by an expansion of polyglutamine tract near the C-terminus of the MJD1 gene product, ataxin-3. The precise mechanism of the MJD/SCA3 pathogenesis remains unclear. A growing body of evidence demonstrates that phosphorylation plays an important role in the pathogenesis of many neurodegenerative diseases. However, few kinases are known to phosphorylate ataxin-3. The present study is to explore whether ataxin-3 is a substrate of casein kinase 2 （CK2）. Methods The interaction between ataxin-3 and CK2 was identified by glutathione S-transferase （GST） pull-down assay and co-immunoprecipition assay. The phosphorylation of ataxin-3 by CK2 was measured by in vitro phosphorylation assays. Results （1） Both wild type and expanded ataxin-3 interacted with CK2α and CK2β in vitro. （2） In 293 cells, both wild type and expanded ataxin-3 interacted with CK2β, but not CK2α. （3） CK2 phosphorylated wild type and expanded ataxin-3. Conclusion Ataxin-3 is a substrate of protein kinase CK2.

长毛兔Kappa-casein基因多态性与生产性能关系的研究

实验对176只长毛兔群体的Kappa-casein基因的基因型和基因频率进行了检测,结果表明:等位基因A和B的频率分别为0.79与0.21,基因型BB在长毛兔群体中的频率为0.09,远低于基因型AA的频率0.66。同时对Kappa-casein基因与长毛兔的生产性能进行分析,表明Kappa-casein基因AA基因型和BB基因型的长毛兔在315日龄体重、21日龄窝重上差异显著(P<0.05),AB基因型和BB基因型的长毛兔产仔数差异显著(P<0.05)。

Ck2α、β-catenin和survivin在卵巢癌组织中表达的检测及其临床应用价值

目的:研究酪蛋白激酶2α(Ck2α)、β-catenin和survivin在卵巢癌组织中的表达情况,分析三者在卵巢癌中表达的相关性,探讨其临床应用价值。方法:采用免疫组织化学法检测8例卵巢单纯性囊肿组织、8例卵巢良性肿瘤组织和29例卵巢癌组织中Ck2α、β-catenin和survivin的表达情况,分析3种蛋白在卵巢癌中表达的相关性及与患者临床病理特征的关系。结果:与卵巢单纯性囊肿和良性卵巢肿瘤组织比较,卵巢癌组织中Ck2α、β-catenin和survivin蛋白表达水平明显升高(P<0.05);卵巢癌组织中Ck2α与β-catenin和survivin表达水平呈正相关关系(r=0.438和r=0.479,P<0.05);在不同分化程度卵巢癌组织中,与低-中分化组比较,高分化组Ck2α、β-catenin和survivin蛋白阳性表达率明显降低(P<0.05);不同FIGO分期中,与Ⅰ期组比较,Ⅱ期组和Ⅲ期组Ck2α、β-catenin和survivin蛋白阳性表达率升高,3组间比较差异有统计学意义(P<0.05)。结论:Ck2α、β-catenin和survivin在卵巢癌组织中的蛋白表达水平增加,且三者呈正相关,可能与卵巢癌的发生发展有关;Ck2α、β-catenin和survivin三者联合检测具有重要的临床应用价值。

A Novel Exponential Kinetic Model for Casein Tryptic Hydrolysis to Prepare Active Peptides

The kinetics of casein tryptic hydrolysis to prepare activepeptides was investigated. Taking into account the reaction mechanismincluding single substrate hydrolysis, irreversible enzymeinactivation, and substrate inhibition, a set of exponentialequations was established to characterize the enzymatic hydrolysiscurves. The verification was carried out by a series of experimentalresults and indicated that the average regressive error was less than5/100. According to the proposed kinetic model, the kinetic constantsand thermodynamic constants of the reaction system were alsocalculated.

Nutritional evaluation of caseins and whey proteins and their hydrolysates from Protamex

Whey protein concentrate (WPC 80) and sodium caseinate were hydrolyzed by Protamex to 5%, 10%, 15%, and 20% degree of hydrolysis (DH). WPC 80, sodium caseinate and their hydrolysates were then analyzed, compared and evaluated for their nutritional qualities. Their chemical composition, protein solubility, amino acid composition, essential amino acid index (EAA index), biological value (BV), nutritional index (NI), chemical score, enzymic protein efficiency ratio (E-PER) and in vitro protein digestibility (IVPD) were determined. The results indicated that the enzymatic hydrolysis of WPC 80 and sodium caseinate by Protamex improved the solubility and IVPD of their hydrolysates. WPC 80, sodium caseinate and their hydrolysates were high-quality proteins and had a surplus of essential amino acids compared with the FAO/WHO/UNU (1985) reference standard. The nutritive value of WPC 80 and its hydrolysates was superior to that of sodium caseinate and its hydrolysates as indicated by some nutritional parameters such as the amino acid composition, chemical score, EAA index and predicted BV. However, the E-PER was lower for the WPC hydrolysates as compared to unhydrolyzed WPC 80 but sodium caseinate and its hydrolysates did not differ significantly. The nutritional qualities of WPC 80, sodium caseinate and their hydrolysates were good and make them appropriate for food formulations or as nutritional supplements.

Low-protein diets supplemented with casein hydrolysate favor the microbiota and enhance the mucosal humoral immunity in the colon of pigs

Background:High-protein diets can increase the colonic health risks.A moderate reduction of dietary crude-protein(CP)level can improve the colonic bacterial community and mucosal immunity of pigs.However,greatly reducing the dietary CP level,even supplemented with all amino acids(AAs),detrimentally affects the colonic health,which may be due to the lack of protein-derived peptides.Therefore,this study evaluated the effects of supplementation of casein hydrolysate(peptide source)in low-protein(LP)diets,in comparison with AAs supplementation,on the colonic microbiota,microbial metabolites and mucosal immunity in pigs,aiming to determine whether a supplementation of casein hydrolysate can improve colonic health under very LP level.Twenty-one pigs(initial BW 19.90±1.00 kg,63±1 days of age)were assigned to three groups and fed with control diet(16%CP),LP diets(13%CP)supplemented with free AAs(LPA)or casein hydrolysate(LPC)for 4 weeks.Results:Compared with control diet,LPA and LPC diet decreased the relative abundance of Streptococcus and Escherichia coli,and LPC diet further decreased the relative abundance of Proteobacteria.LPC diet also increased the relative abundance of Lactobacillus reuteri.Both LP diets decreased concentrations of ammonia and cadaverine,and LPC diet also reduced concentrations of putrescine,phenol and indole.Moreover,LPC diet increased total short-chain fatty acid concentration.In comparison with control diet,both LP diets decreased protein expressions of Toll-like receptor-4,nuclear factor-κB,interleukin-1βand tumor necrosis factor-α,and LPC diet further decreased protein expressions of nucleotide-binding oligomerization domain protein-1 and interferon-γ.LPC diet also increased protein expressions of G-protein coupled receptor-43,interleukin-4,transforming growth factor-β,immunoglobulin A and mucin-4,which are indicators for mucosal defense activity.Conclusions:The results showed that supplementing casein hydrolysate showed beneficial effects on the colonic microbiota and mucosal immunity and barrier function in comparison with supplementing free AAs in LP diets.These findings may provide new framework for future nutritional interventions for colon health in pigs.

Identification and characterization of a novel bipartite nuclear localization signal in the hepatitis B virus polymerase

AIM: To characterize the nuclear import of hepatitis B virus (HBV) polymerase (P) and its relevance for the viral life cycle.METHODS: Sequence analysis was performed to predict functional motives within P. Phosphorylation of P was analyzed by in vitro phosphorylation. Phosphorylation site and nuclear localization signal (NLS) were destroyed by site directed mutagenesis. Functionality of the identified NLS was analyzed by confocal fluorescence microscopy and characterizing the karyopherin binding. Relevance of the structural motives for viral life cycle was studied by infection of primary Tupaia hepatocytes with HBV.RESULTS: We identified by sequence alignment and functional experiments a conserved bipartite NLS containing a casein kinase II (CKII) phosphorylation site located within the terminal protein domain (TP) of the HBV polymerase. Inhibition of CKII impairs the functionality of this NLS and thereby prevents the nuclear import of the polymerase. Binding of the import factor karyopherin-α2 to the polymerase depends on its CKII-mediated phosphorylation of the bipartite NLS. In HBV-infected primary Tupaia hepatocytes CKII inhibition in the early phase (post entry phase) of the infection process prevents the establishment of the infection.CONCLUSION: Based on these data it is suggested that during HBV infection the final import of the genome complex into the nucleus is mediated by a novel bipartite NLS localized in the TP domain of HBV polymerase.

In vitro and in silico analysis of dual-function peptides derived from casein hydrolysate

There is no study on food-derived peptide with both anticoagulant and angiotensin I-converting enzyme inhibitory (ACEI) activities yet. In this work, the anticoagulant and ACEI activities of the casein hydrolysates released by pepsin digestion were evaluated for the first time to the best of our knowledge. Results indicated that the casein hydrolysate exhibited potent anticoagulant activity by prolonging the thrombin time (TT) and the activated partial thromboplastin time (APTT). Compared with control samples, at 10 mg/mL, the TT and APTT of casein hydrolysate were 186.0 % ± 6.6 % and 163.5 % ± 7.4 %, respectively. The casein hydrolysate also showed a strong ACEI activity with an IC50 value of 1.775 mg/mL. The components of the bioactive casein hydrolysate were analyzed by nanoscale liquid chromatography quadrupole time-of-flight tandem mass spectrometry (NanoLC-Q-TOF-MS/MS). Total of 115 peptides were identified, among which 34, 9, 55 and 17 peptides were derived from α_(s1-), α_(s2-), β-, and κ-casein, respectively. The results of PeptideRanker and PepSite 2 analysis showed that 6 peptides (FRQFYQL, NENLLRF, NPWDQVKR, PVVVPPFLQ, PVRGPFPIIV, and ARHPHPHLSF) have both ACEI and anticoagulant activities by binding to the active sites of ACE and thrombin. This study indicated that casein is a potential functional food supplement that can be used for medical purposes.

Esophageal obstruction due to enteral feed bezoar:A case report and literature review

This paper describes a rare complication of enteral feeding,esophageal obstruction due to feeding formula bezoar,and reviews the published cases. An attempt to re-insert the nasogastric tube in a chronically ventilated 80-year-old female fed via a nasogastric tube with Jevity failed. An esophagogastroduodenoscopy revealed an 18 cm-long concretion of the feeding formula,fi-lling most of the esophageal lumen,which was removed endo scopically. Forty-two cases of feeding formula esophageal bezoars have been reported in the literature. The formation of feeding formula bezoars is triggered by acidic gastroesophageal reflux. The acidic pH in the esophagus causes clotting of the casein in the formula. Predisposing factors for bezoar formation are:mechanical ventilation,supine position,neurological diseases,diabetes mellitus,hypothyroidism,obesity and history of partial gastrectomy. Diagnosis and removal of the bezoar is done endoscopically. Feeding in a semi-recumbent position,administration of prokinetic agents and proton pump inhibitors may prevent this complication.

Effects of undigested protein-rich ingredients on polarised small intestinal organoid monolayers

Here, we describe the use of monolayers of intestinal epithelial cells derived from intestinal organoids and transcriptomics to investigate the direct effects of dietary protein sources on epithelial function. Mechanically dissociated 3 D organoids of mouse duodenum were used to generate a polarized epithelium containing all cell types found in the tissue of origin. The organoid-derived cell monolayers were exposed to 4%(w/v) of ‘undigested(non-hydrolysed)-soluble' fraction of protein sources used as feed ingredients [soybean meal(SBM) and casein], or alternative protein sources(spray dried plasma protein, and yellow meal worm), or controls for 6 h prior to RNA isolation and transcriptomics. All protein sources altered expression of unique biological processes in the epithelial cells. Exposure of intestinal organoids to SBM downregulated expression of retinol and retinoid metabolic processes as well as cholesterol and lipid biosynthetic pathways, consistent with the reported hypotriglyceridaemic effect of soy protein in vivo. These findings support the use of intestinal organoids as models to evaluate complex interactions between dietary ingredients and the intestinal epithelium and highlights some unique host effects of alternative protein sources in animal feed and potentially human food.

Isolation and identification of novel casein-derived bioactive peptides and potential functions in fermented casein with Lactobacillus helveticus

The present study here establishes a complete and effective method for isolating,purifying and identifying extracellular and intracellular peptides,and also describes the characters and bioactivities of peptides from fermented casein with Lactobacillus helveticus.Intracellular peptides are much larger in quantity and more complex in composition than extracellular peptides,between which the correlation reveals proteolytic and metabolic mechanisms.In addition,totally 241 different peptide sequences were identified by Nano LC–MS/MS from casein(212)and Lactobacillus helveticus proteins(29).These casein-derived peptides mostly originated from-casein,followed byS1-casein,-casein,andS2-casein,and came from extracell(69)and intracell(143),in which common peptides have a total of 27.Forty-four of the identified peptides were previously described as bioactive,including angiotensinconverting enzyme(ACE)-inhibitory,antioxidant,immunomodulating,antimicrobial,DPP-IV inhibitory,antiamnesic and anticancer effects and so on.Thirteen peptides with the potential of some biological activities are obtained,which were described in previous studies.A total of 47 novel peptides of 5 to 26 amino acids that were not disclosed were obtained.The new sources of natural bioactive peptides may have the very high application value as potential new peptide drugs for treatment human diseases.The product peptide DELQDKIHPF found in both extracell and intracell was quantitatively analyzed using the MRM mode of UPLC-U3Q,23.1 and 9.76 ng/mL,respectively.The quantitative analysis of the potential bioactive peptide may also advance the production of peptide products in the future.

Potential of casein kinase I in digestive cancer screening

Casein kinase I is a group of ubiquitous Serine/Threonine kinases that have been implicated in both normal cellular functions and several pathological conditions including Alzheimer's disease and cancer.Recent findings in colon and pancreatic cancer have brought tremendous attention to these molecules as potential therapeutic targets in treatment of digestive cancers.In this review,we summarize up to date what is known about this family of kinases and their involvement in carcinogenesis and other pathological conditions.Our emphasis is on their implications in digestive cancers and their potential for cancer screening and therapy.

Biomass accumulation of Panax vietnamensis in cell suspension cultures varies with addition of plant growth regulators and organic additives

Objective: To evaluate the impact of plant growth regulators including kinetin(KN),benzyl adenine and naphthalene acetic acid, yeast extract and casein hydrolyzate on biomass accumulation of Vietnamese ginseng Panax vietnamensis(P. vietnamensis) in cell suspension culture.Methods: Cell suspension cultures were established from friable calluses derived from leaves and petioles of 3-year-old in-vitro P. vietnamensis plants. The cell suspension cultures were grown in Murashige and Skoog basal media supplemented with various concentrations of KN, benzyl adenine, naphthalene acetic acid, and yeast extract and casein hydrolyzate.Results: All tested factors generated an increase in the cell biomass of P. vietnamensis in suspension culture, but the impact of each varies depended on the factor type, concentration, and incubation period. Addition of 2.0 mg/L KN resulted in the largest biomass increase after 24 d,(57.0 ± 0.9) and(3.1 ± 0.1) mg/m L fresh and dry weight, respectively,whereas addition of benzyl adenine or naphthalene acetic acid produced optimum levels of Panax cell biomass at 1.0 and 1.5 mg/L, respectively. Addition of the elicitor yeast extract led to a 1.4–2.4 fold increase in biomass of P. vietnamensis, while addition of casein hydrolyzate enhanced biomass accumulation 1.8–2.6 fold.Conclusions: The addition of each factor causes significant changes in biomass accumulation of P. vietnamensis. The largest biomass accumulation is from cultures grown in MS media containing 2.0 mg/L KN for 24 d. The outcome of the present study provides new insights into the optimal suspension culture conditions for studies on the in vitro cell biomass production of P. vietnamensis.

Alginate-Casein Microspheres as Bioactive Vehicles for Nutrients

The aim of this work was to develop an alginate-casein composite microsphere as a bioaetive vehicle for oral administration of nutrients by a simple extrusion dripping method. Riboflavin was selected as a model drug, and the microencapsulation efficiency was raised to 97.94% after optimizing the preparation conditions by response surface methodology. In vitro release studies showed that riboflavin was released completely from alginate-casein microspheres in simulated intestinal fluids. Meanwhile, the morphology, structure and interaction between alginate and casein were characterized by scanning electron microscopy （SEM） and Fourier transform infrared （FTIR） spectra.

Efficacy of two calcium phosphate pastes on the remineralization of artificial caries: a randomized controlled double-blind in situ study

To test the efficacy of two calcium phosphate pastes compared to that of fluoride toothpaste on remineralizing artificial caries in situ, this study had a double-blind crossover in situ design, involving three experimental phases of 14 days each, with an 8-day washout period between phases. Nine healthy subjects participated in the study. The subjects wore removable palatal appliances mounted with six human enamel slabs with artificial caries lesions, and in each of the experimental phases, used one of the following methods two times/day： group A, brushing with 1.0 g of Colgate Regular Flavor, followed by applying 0.25 g of Tooth Mousse Plus; group B, brushing with 0.25 g of Clinpro Tooth Crbme; and group C, brushing with 1.0 g of Colgate Regular Flavor. After 14 days, the enamel slabs （54 slabs/ group） were embedded in resin, sectioned and examined with a polarized-light microscope, and the lesion areas were quantified using Image-Pro Plus. All experimental groups showed a significant reduction in lesion area compared to the initial lesion area （paired t-test, P〈O.O01）. The mean reduction in lesion area of Groups A, B and C were （0.029__.0.010）, （0.030_＋0.009） and （0.027_＋0.009） mm2, respectively. There were no statistical differences between groups （KruskaI-Wallis test, P〉0.05）. All three groups remineralized the enamel slab lesions, indicating model sensitivity to fluoride. Given the differences in usage amounts and treated regimens, Clinpro Tooth Crbme provided similar benefits to the fluoride toothpaste; however, no additional benefit of Tooth Mousse Plus was observed when used in conjunction with the fluoride toothpaste.

Potential Applications of Milk Fractions and Valorization of Dairy By-Products: A Review of the State-of-the-Art Available Data, Outlining the Innovation Potential from a Bigger Data Standpoint

The unique composition of milk makes this basic foodstuff into an exceptional raw material for the production of new ingredients with desired properties and diverse applications in the food industry. The fractionation of milk is the key in the development of those ingredients and products;hence continuous research and development on this field, especially various levels of fractionation and separation by filtration, have been carried out. This review focuses on the production of milk fractions as well as their particular properties, applications and processes that increase their exploitation. Whey proteins and caseins from the protein fraction are excellent emulsifiers and protein supplements. Besides, they can be chemically or enzymatically modified to obtain bioactive peptides with numerous functional and nutritional properties. In this context, valorization techniques of cheese-whey proteins, by-product of dairy industry that constitutes both economic and environmental problems, are being developed. Phospholipids from the milk fat fraction are powerful emulsifiers and also have exclusive nutraceutical properties. In addition, enzyme modification of milk phospholipids makes it possible to tailor emulsifiers with particular properties. However, several aspects remain to be overcome;those refer to a deeper understanding of the healthy, functional and nutritional properties of these new ingredients that might be barriers for its use and acceptability. Additionally, in this review, alternative applications of milk constituents in the non-food area such as in the manufacture of plastic materials and textile fibers are also introduced. The unmet needs, the cross-fertilization in between various protein domains,the carbon footprint requirements, the environmental necessities, the health and wellness new demand, etc., are dominant factors in the search for innovation approaches;these factors are also outlining the further innovation potential deriving from those “apparent” constrains obliging science and technology to take them into account.