Bid mediates lysosomal membrane permeabilization and the consequent mitochondrial outer membrane permeabilization in RH-35 hepatoma cells

We reported previously that chymotrypsin B is cached in the lysosomes of rat hepatocytes and mediates apoptosis induced by TNF-alpha (1) and H2O2. However, the mechanism

Efficient reduction ofβ-lactoglobulin allergenicity in milk using Clostridium tyrobutyricum Z816

Milk allergy is one of the most common food allergies,affecting 6%of young children,andβ-lactoglobulin(β-LG)is the main milk allergen.Clostridium tyrobutyricum Z816 was selected for the degradation ofβ-LG,which was successfully reduced by about 90%using permeabilized bacteria under the optimized conditions.The hydrolyzed peptides were identified by liquid chromatography-tandem mass spectrometry(LC-MS/MS)and analyzed by molecular modeling,which indicated that C.tyrobutyricum Z816 could effectively degrade the antigenic epitopes ofβ-LG.Finally,the concentration and digestibility ofβ-LG in actual samples was quantified using enzyme-linked immunosorbent assay(ELISA)and gastrointestinal digestion simulation experiments.The results showed more than 92%ofβ-LG in actual samples was hydrolyzed,and the gastric and total digestibility of whey protein isolate(WPI)was improved by 85.96%and 64.51%,respectively.Therefore,C.tyrobutyricum Z816 offers an effective method to degradeβ-LG and reduce the occurrence of milk allergies,which has great significance for the development of hypoallergenic dairy products.

Gender-related differences in irritable bowel syndrome: Potential mechanisms of sex hormones

According to epidemiological studies,twice as many women as men are affected by irritable bowel syndrome(IBS)in western countries,suggesting a role for sex hormones in IBS pathophysiology.Despite growing evidence about the implications of sex hormones in IBS symptom modulation,data on mechanisms by which they influence disease development are sparse.This review aims to determine the state of knowledge about the role of sex hormones in sensorimotor dysfunctions and to address the possible interplay of sex hormones with common risk factors associated with IBS.The scientific bibliography was searched using the following keywords:irritable bowel syndrome,sex,gender,ovarian hormone,estradiol,progesterone,testosterone,symptoms,pain,sensitivity,motility,permeability,stress,immune system,brain activity,spinal,supraspinal,imaging.Ovarian hormones variations along themenstrual cycle affect sensorimotor gastrointestinal function in both healthy and IBS populations.They can modulate pain processing by interacting with neuromodulator systems and the emotional system responsible for visceral pain perception.These hormones can also modulate the susceptibility to stress,which is a pivotal factor in IBS occurrence and symptom severity.For instance,estrogen-dependent hyper-responsiveness to stress can promote immune activation or impairments of gut barrier function.In conclusion,whereas it is important to keep in mind that ovarian hormones cannot be considered as a causal factor of IBS,they arguably modulate IBS onset and symptomatology.However,our understanding of the underlying mechanisms remains limited and studies assessing the link between IBS symptoms and ovarian hormone levels are needed to improve our knowledge of the disease evolution with regard to gender.Further studies assessing the role of male hormones are also needed to understand fully the role of sex hormones in IBS.Finally,investigation of brain-gut interactions is critical to decipher how stress,ovarian hormones,and female brain processing of pain can translate into gut dysfunctions.

MiR-183-5p-PNPT1 Axis Enhances Cisplatin-induced Apoptosis in Bladder Cancer Cells

Objective:It has been reported that intrinsic apoptosis is associated with the progression of bladder cancer(BC).Recent evidence suggests that polyribonucleotide nucleotidyltransferase 1(PNPT1)is a pivotal mediator involved in RNA decay and cell apoptosis.However,the regulation and roles of PNPT1 in bladder cancer remain largely unclear.Methods:The upstream miRNA regulators were predicted by in silico analysis.The expression levels of PNPT1 were evaluated by real-time PCR,Western blotting,and immunohistochemistry(IHC),while miR-183-5p levels were evaluated by qPCR in BC cell lines and tissues.In vitro and in vivo assays were performed to investigate the function of miR-183-5p and PNPT1 in apoptotic RNA decay and the tumorigenic capability of bladder cancer cells.Results:PNPT1 expression was decreased in BC tissues and cell lines.Overexpression of PNPT1 significantly promoted cisplatin-induced intrinsic apoptosis of BC cells,whereas depletion of PNPT1 potently alleviated these effects.Moreover,oncogenic miR183-5p directly targeted the 3′UTR of PNPT1 and reversed the tumor suppressive role of PNPT1.Intriguingly,miR-183-5p modulated not only PNPT1 but also Bcl2 modifying factor(BMF)to inhibit the mitochondrial outer membrane permeabilization(MOMP)in BC cells.Conclusion:Our results provide new insight into the mechanisms underlying intrinsic apoptosis in BC,suggesting that the miR-183-5p-PNPT1 regulatory axis regulates the apoptosis of BC cells and might represent a potential therapeutic avenue for the treatment of BC.

Salvianolic acid B protects hepatocytes from H2O2 injury by stabilizing the lysosomal membrane

AIM To investigate the capability of salvianolic acid B(Sal B) to protect hepatocytes from hydrogen peroxide(H_2O_2)/carbon tetrachloride(CCl_4)-induced lysosomal membrane permeabilization. METHODS Cell Counting Kit-8 assay was used to measure cell viability. Apoptosis and death were assayed through flow cytometry. Brd U incorporation was used to detect cell proliferation. Serum alanine aminotransferase activity and liver malondialdehyde(MDA) content were measured. Liver histopathological changes were evaluated using hematoxylin-eosin staining. Lysosomal membrane permeability was detected with Lyso Tracker Green-labeled probes and acridine orange staining. The levels of protein carbonyl content(PCC), cathepsins(Cat)B/D, and lysosome-associated membrane protein 1(LAMP1) were evaluated through western blotting. Cytosol Cat B activity analysis was performed with chemiluminescence detection. The m RNA level ofLAMP1 was evaluated through quantitative real-time polymerase chain reaction. RESULTS Results indicated that H_2O_2 induced cell injury/death. Sal B attenuated H_2O_2-induced cell apoptosis and death, restored the inhibition of proliferation, decreased the amount of PCC, and stabilized the lysosome membrane by increasing the LAMP1 protein level and antagonizing Cat B/D leakage into the cytosol. CCl_4 also triggered hepatocyte death. Furthermore, Sal B effectively rescued hepatocytes by increasing LAMP1 expression and by reducing lysosomal enzyme translocation to the cytosol.CONCLUSION Sal B protected mouse embryonic hepatocytes from H_2O_2/CCl_4-induced injury/death by stabilizing the lysosomal membrane.

Mitocans as Novel Agents for Anticancer Therapy: An Overview

Many conventional anticancer drugs have an associated lack of safety by their toxicity. Relatively faster mutations in tumor cells pose a significant obstacle in treatment of cancer. Recently, “Mitocans” have emerged as a novel class of anticancer agents selectively targeting tumor cells and thus, are much less toxic than conventional anticancer chemotherapeutic agents. Mitocans are drugs that act directly on mitochondria within the cell, thus causing changes in energy metabolism of the cell. Amongst these mitocans, α-Tocopheryl succinate or vitamin E analogs are studied very well by researchers. This review discusses mitochondrial drug targeting strategies and a variety of novel mitochondrial drug targets of mitocans, such as electron transport chain, mitochondrial permeability transition, Bcl-2 family proteins and mitochondrial DNA. The purpose of this review is to focus on the various classes of mitocans, the mechanisms by which these drugs specifically act on tumor cells and their applications in cancer chemotherapeutics.

First Estimation of Drosophila EPS Solution for Permeabilizing Lepidoptera <i>Galleria mellonella</i>Embryos

The increased importance of the G. mellonella for wide range of scientific research and commercial sides will need to create a germplasm resource banking by cryopreservation. Impermeability is a fundamental limiting factor for the successful cryopreservation of arthropods embryos. The successful permeability of Drosophila embryo by using an embryo permeabilization solvent (EPS) solution encouraged this trial on G. mellonella embryos (stage of 24 hours Post-oviposition (h PO)). Permeability assessment with Rhodamine B and crystal violet dyes showed that G. mellonella embryos can be permeabilized by EPS of D-limonene that has 3 mol ethoxylated alcohol. The permeabilization for 30 sec exposure time was resulted 61.5% ± 5.8% survival rate, 31.7% ± 3.1% uptakes dyes and 40.5% ± 0.3% was the survival rate post loading in 12% Ethylene glycol (EG). The low viability after immersion in liquid nitrogen (LN) (0.6% ± 0.08%) is due to the dual toxicity of EPS and cryoprotectant (CPA) solutions. However, fluorescence images showed sufficient permeability that confirms the possibility to increase the permeability of G. mellonella embryos with EPS solution, and to have the opportunity to improve the viability after LN by improving procedures of loading and dehydration with various CPAs and exposure times, which decrease the toxicity effect.

Potentiating activity of luteolin on membrane permeabilizing agent and ATPase inhibitor against methicillin-resistant Staphylococcus aureus

Objective:To investigate the mechanism of antibacterial activity of luteoiin(LUT) against methicillin-resistant Staphylococcus aureus(MRSA).Methods:The mechanism of anti-MRSA activity of LUT was analyzed by the viability assay in membrane permeabilizing agent ATPase inhibitors,and peptidoglycan(PGN) derived from Staphylococcus aureus(S.aureus).Also,transmission electron microscopy was used to monitor survival characteristics and changes in S.aureus morphology.Results:Compared to the LUT alone,the optical density of suspensions treated with the combination of 125 μg/mL Tris and 230 μg/mL DCCD were reduced to 60%and 46%,respectively.PGN(15.6 μg/mL) gradually impeded the activity of LUT,and PGN(62.5 μg/mL) completely blocked the activity of LUT on S.aureus.Conclusions:Increased susceptibility to LUT with me Tris and DCCD combinations is evident in all tested MRSA isolates.The results indicate LUT synergy in increasing cytoplasmic membrane permeability and inhibiting ATPase.S.aureus PGN directly blocks the antibacterial activity of LUT,suggesting the direct binding of LUT with PGN.These findings may be validated for the development of antibacterial agent for low MRSA resistance.

Discovery of natural berberine-derived nitroimidazoles as potentially multi-targeting agents against drug-resistant Escherichia coli

A series of natural berberine-derived nitroimidazoles as novel antibacterial agents were designed, synthesized and characterized by nuclear magnetic resonance(NMR), infrared spectra(IR), and high resolution mass spectra(HRMS) spectra. The antimicrobial evaluation showed that some target molecules exhibited moderate to good inhibitory activities against the tested bacteria and fungi including clinical drug-resistant strains isolated from infected patients. Especially, 2-fluorobenzyl derivative8 f not only gave strong activity against drug-resistant E. coli with the minimal inhibitory concentration(MIC) value of0.003 m M, 33-fold more active than norfloxacin, but also exhibited low toxicity toward RAW 264.7 cells and less propensity to trigger resistance. The aqueous solubility and Clog P values of target compounds were investigated to elucidate the structureactivity relationships. Molecular docking and quantum chemical studies for compound 8 f rationally explained its antibacterial effect. The further exploration of antibacterial mechanism revealed that the highly active compound 8 f could effectively permeabilize E. coli cell membrane and intercalate into DNA isolated from resistant E. coli to form 8 f-DNA complex that might block DNA replication to exert the powerful bioactivities. Compound 8 f could also selectively address resistant E. coli from a mixture of various strains.

Cholesterol-associated lysosomal disorder triggers cell death of hematological malignancy:Dynamic analysis on cytotoxic effects of LW-218

The integrity of lysosomes is of vital importance to survival of tumor cells.We demonstrated that LW-218,a synthetic flavonoid,induced rapid lysosomal enlargement accompanied with lysosomal membrane permeabilization in hematological malignancy.LW-218-induced lysosomal damage and lysosome-dependent cell death were mediated by cathepsin D,as the lysosomal damage and cell apoptosis could be suppressed by depletion of cathepsin D or lysosome alkalization agents,which can alter the activity of cathepsins.Lysophagy,was initiated for cell self-rescue after LW-218 treatment and correlated with calcium release and nuclei translocation of transcription factor EB.LW-218 treatment enhanced the expression of autophagy-related genes which could be inhibited by intracellular calcium chelator.Sustained exposure to LW-218 exhausted the lysosomal capacity so as to repress the normal autophagy.LW-218-induced enlargement and damage of lysosomes were triggered by abnormal cholesterol deposition on lysosome membrane which caused by interaction between LW-218 and NPC intracellular cholesterol transporter 1.Moreover,LW-218 inhibited the leukemia cell growth in vivo.Thus,the necessary impact of integral lysosomal function in cell rescue and death were illustrated.

AAV6 as an effective gene delivery vector for prolonged transgene expression in intervertebral disc cells in vivo

Intervertebral disc degeneration is the main contributor to low back pain,now the leading cause of disability worldwide.Gene transfer,either in a therapeutic attempt or in basic research to understand the mechanisms of disc degeneration,is a fascinating and promising tool to manipulate the complex physiology of the disc.Viral vectors based on the adeno-associated virus(AAV)have emerged as powerful transgene delivery vehicles yet a systematic investigation into their respective tropism,transduction efficiency,and relative toxicity have not yet been performed in the disc in vivo.Herein,we used in vivo bioluminescence imaging to systematically compare multiple AAV serotypes,injection volumes,titers,promoters,and luciferase reporters to determine which result in high transduction efficiency of murine nucleus pulposus(NP)cells in vivo.We find that AAV6 using a CAG promoter to drive transgene expression,delivered into the NP of murine caudal discs at a titer of 1011 GC/mL,provides excellent transduction efficiency/kinetics and low toxicity in vivo.We also show,for the first time,that the transduction of NP cells can be significantly boosted in vivo by the use of small cell permeabilization peptides.Finally,to our knowledge,we are the first to demonstrate the use of optical tissue clearing and three-dimensional lightsheet microscopy in the disc,which was used to visualize fine details of tissue and cell architecture in whole intact discs following AAV6 delivery.Taken together,these data will contribute to the success of using AAV-mediated gene delivery for basic and translational studies of the IVD.

Bioproduction of D-psicose using permeabilized cells of newly isolated Rhodobacter sphaeroides SK011

D-psicose exits in an extremely small amount in nature and is difficult to be chemically synthesized.Only three bacteria have been used in the biotransformation of D-psicose from D-fructose.In this paper,another bacterium which could convert D-fructose to D-psicose was isolated and identified as Rhodobacter sphaeroides.The process parameters of D-psicose production using permeabilized cells of Rhodobacter sphaeroides SK011 were optimized,including the permeabilization procedure:0.1%(w/v)CTAB,10 min,and reaction conditions:cell concentration,30 g dry cell wt/L;concentration of substrate,50 g/L;40℃,pH 9.0;reaction time,8 h.Under the optimized conditions,the permeabilized cells produced approximately 6.5 g/L D-psicose with a Dpsicose productivity of 0.82 g·L^(-1)·h^(-1).This is the first report of bioproduction of D-psicose using permeabilized cells of Rhodobacter sphaeroides.

COAL GEOLOGY

20112437Cao Daiyong(State Key Laboratory of Coal Resources and Safe Exploitation, China University of Mining and Technology,Beijing 100083,China);Sun