Dynamin1 long- and short-tail isoforms exploit distinct recruitment and spatial patterns to form endocytic nanoclusters

Endocytosis requires a coordinated framework of molecular interactions that ultimately lead to the fission of nascent endocytic structures. How cytosolic proteins such as dynamin concentrate at discrete sites that are sparsely distributed across the plasma membrane remains poorly understood. Two dynamin-1 major splice variants differ by the length of their C-terminal proline-rich region (short-tail and long-tail). Using sptPALM in PC12 cells, neurons and MEF cells, we demonstrate that short-tail dynamin-1 isoforms ab and bb display an activity-dependent recruitment to the membrane, promptly followed by their concentration into nanoclusters. These nanoclusters are sensitive to both Calcineurin and dynamin GTPase inhibitors, and are larger, denser, and more numerous than that of long-tail isoform aa. Spatiotemporal modelling confirms that dynamin-1 isoforms perform distinct search patterns and undergo dimensional reduction to generate endocytic nanoclusters, with short-tail isoforms more robustly exploiting lateral trapping in the generation of nanoclusters compared to the long-tail isoform.

Surgical sensation during caesarean section: a qualitative analysis

BACKGROUND

Caesarean section (CS) is a major abdominal surgery performed usually on a young and healthy population under neuraxial anesthesia with little to no sedation. This creates a distinct surgical experience whereby patients are aware of the surgical process, physical sensations, and their environment. This study aimed to provide an in-depth descriptive assessment of subjective surgical experience during CS under regional anaesthesia. We expected the information gained would enhance our current understanding and better alleviate patient anxiety through informed counselling.

METHODS

This qualitative descriptive study was conducted at a Canadian academic centre. Twenty patients participated in semi-structured interviews within a week of CS, using an interview guide developed for this study. Patient medical records were reviewed to collect demographic and surgical information. Thematic analysis was conducted using an inductive approach to determine common themes.

RESULTS

Nine themes were identified. Five themes were identified in the category of surgical sensation and four themes were identified in the category of peri-operative education.

CONCLUSIONS

Patients commonly experienced pressure and movement sensations at varying intensity, and most did not experience pain. Environmental factors, including sounds and distraction by the newborn, affected perception of surgical sensation. Patients wish to receive pre-operative counselling regarding potential surgical sensations, as well as ongoing communication from their anaesthesiologist. These results can be used to guide informed discussions with patients and direct further investigation in this area.

Interrogation and validation of the interactome of neuronal Munc18-interacting Mint proteins with AlphaFold2

Munc18-interacting proteins (Mints) are multidomain adaptors that regulate neuronal membrane trafficking, signaling, and neurotransmission. Mint1 and Mint2 are highly expressed in the brain with overlapping roles in the regulation of synaptic vesicle fusion required for neurotransmitter release by interacting with the essential synaptic protein Munc18-1. Here, we have used AlphaFold2 to identify and then validate the mechanisms that underpin both the specific interactions of neuronal Mint proteins with Munc18-1 as well as their wider interactome. We found that a short acidic α-helical motif within Mint1 and Mint2 is necessary and sufficient for specific binding to Munc18-1 and binds a conserved surface on Munc18-1 domain3b. In Munc18-1/2 double knockout neurosecretory cells, mutation of the Mint-binding site reduces the ability of Munc18-1 to rescue exocytosis, and although Munc18-1 can interact with Mint and Sx1a (Syntaxin1a) proteins simultaneously in vitro, we find that they have mutually reduced affinities, suggesting an allosteric coupling between the proteins. Using AlphaFold2 to then examine the entire cellular network of putative Mint interactors provides a structural model for their assembly with a variety of known and novel regulatory and cargo proteins including ADP-ribosylation factor (ARF3/ARF4) small GTPases and the AP3 clathrin adaptor complex. Validation of Mint1 interaction with a new predicted binder TJAP1 (tight junction-associated protein 1) provides experimental support that AlphaFold2 can correctly predict interactions across such large-scale datasets. Overall, our data provide insights into the diversity of interactions mediated by the Mint family and show that Mints may help facilitate a key trigger point in SNARE (soluble N-ethylmaleimide-sensitive factor attachment receptor) complex assembly and vesicle fusion.

Presynaptic targeting of botulinum neurotoxin type A requires a tripartite PSG-Syt1-SV2 plasma membrane nanocluster for synaptic vesicle entry

The unique nerve terminal targeting of botulinum neurotoxin type A (BoNT/A) is due to its capacity to bind two receptors on the neuronal plasma membrane: polysialoganglioside (PSG) and synaptic vesicle glycoprotein 2 (SV2). Whether and how PSGs and SV2 may coordinate other proteins for BoNT/A recruitment and internalization remains unknown. Here, we demonstrate that the targeted endocytosis of BoNT/A into synaptic vesicles (SVs) requires a tripartite surface nanocluster. Live-cell super-resolution imaging and electron microscopy of catalytically inactivated BoNT/A wildtype and receptor-binding-deficient mutants in cultured hippocampal neurons demonstrated that BoNT/A must bind coincidentally to a PSG and SV2 to target synaptic vesicles. We reveal that BoNT/A simultaneously interacts with a preassembled PSG-synaptotagmin-1 (Syt1) complex and SV2 on the neuronal plasma membrane, facilitating Syt1-SV2 nanoclustering that controls endocytic sorting of the toxin into synaptic vesicles. Syt1 CRISPRi knockdown suppressed BoNT/A- and BoNT/E-induced neurointoxication as quantified by SNAP-25 cleavage, suggesting that this tripartite nanocluster may be a unifying entry point for selected botulinum neurotoxins that hijack this for synaptic vesicle targeting.

Super-resolved trajectory-derived nanoclustering analysis using spatiotemporal indexing

Single-molecule localization microscopy techniques are emerging as vital tools to unravel the nanoscale world of living cells by understanding the spatiotemporal organization of protein clusters at the nanometer scale. Current analyses define spatial nanoclusters based on detections but neglect important temporal information such as cluster lifetime and recurrence in "hotspots" on the plasma membrane. Spatial indexing is widely used in video games to detect interactions between moving geometric objects. Here, we use the R-tree spatial indexing algorithm to determine the overlap of the bounding boxes of individual molecular trajectories to establish membership in nanoclusters. Extending the spatial indexing into the time dimension allows the resolution of spatial nanoclusters into multiple spatiotemporal clusters. Using spatiotemporal indexing, we found that syntaxin1a and Munc18-1 molecules transiently cluster in hotspots, offering insights into the dynamics of neuroexocytosis. Nanoscale spatiotemporal indexing clustering (NASTIC) has been implemented as a free and open-source Python graphic user interface.

Increased Sparc release from subchondral osteoblasts promotes articular chondrocyte degeneration under estrogen withdrawal

OBJECTIVE

The incidence of osteoarthritis (OA) in menopausal women is significantly higher than in same-aged men. Investigating the role of subchondral osteoblasts in estrogen deficiency-induced OA may help elucidate the pathological mechanism, providing new insights for the diagnosis and treatment of menopausal OA.

METHODS

A classical ovariectomy-induced OA (OVX-OA) rat model was utilized to isolate primary articular chondrocytes and subchondral osteoblasts, which were identified and then cocultured in Transwell. The expression of chondrocyte anabolic and catabolic indicators was evaluated. The differentially expressed proteins in the conditioned medium (CM) of osteoblasts were identified by Liquid Chromatograph-Mass Spectrometer (LC-MS/MS). Normal chondrocytes were treated with osteoblast CM, and then RNA sequencing was performed on the treated chondrocytes. KEGG was used to identify significant enrichment of signaling pathways, and Simple Western was used to verify the expression of related proteins in the signaling pathways.

RESULTS

Coculture of OVX-OA subchondral osteoblasts with chondrocytes significantly downregulated the expression of the anabolic indicators and upregulated the expression of the catabolic indicators in chondrocytes. 1,601 proteins were identified in both normal and OVX osteoblast culture supernatants. Protein-protein interaction network analysis revealed that Sparc was one of the hub proteins. The AMPK/Foxo3a signaling pathway of chondrocytes was downregulated by OVX-OA osteoblasts CM. AICAR, the AMPK agonist, partially reversed the catabolic effect of OVX-OA osteoblasts on chondrocytes.

CONCLUSIONS

Sparc secreted by OVX-OA subchondral osteoblasts can downregulate the AMPK/Foxo3a signaling pathway of chondrocytes, thereby promoting chondrocyte degeneration.

Correlation between oral fluid and blood THC concentration: A systematic review and discussion of policy implications

Cannabis is the second most commonly used impairing substance by drivers, after alcohol. As more countries legalize cannabis, there is concern that cannabis-impaired driving will increase. In many countries, police use roadside devices to test for oral fluid THC (the primary psychotropic component in cannabis) to identify drivers who used cannabis; including in countries with non-zero per se limits for THC in blood. This practice is questioned as previous research demonstrates a poor correlation between oral fluid and blood THC concentrations at the individual level. We conducted a meta-analysis to identify all research that compared oral fluid with blood THC levels. We obtained individual-level data from study authors and analyzed pooled individual-level data to calculate sensitivity and specificity of oral fluid THC (at various cut-off values) to detect blood THC above different concentration limits. Finally, we explored practical implications of using oral fluid THC in an enforcement context. Our review found THC concentrations measured in over 18,000 paired samples of oral fluid and blood. We found a good correlation between the presence of THC in oral fluid and presence of THC in blood (sensitivity = 71.2%, specificity = 97.7%). However oral fluid THC, at commonly used cut-off values, is less sensitive and less specific when used as a biomarker to detect people with blood THC concentrations above commonly used per se limits (such as 5 ng/mL). As such, there will be a large number of "false positive" tests if oral fluid THC testing were used as a biomarker for "illegal" THC concentrations in randomly selected drivers. We argue that the adverse implications of false positive oral fluid THC tests in this context outweigh the possible road safety benefits and we recommend against oral fluid THC screening in randomly selected drivers in countries with non-zero per se limits for blood THC. In contrast, oral fluid THC tests appear to be useful for investigating "high-risk" drivers who come to police attention because of evidence of impairment.

Crucial functions of alpha-actinin 2 in the embryonic heart

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Wellcome Trust; British Heart Foundation

Background/Introduction

Alpha-actinin is an integral protein of the Z-discs in heart and skeletal muscle cells, with important structural and signalling functions.  Missense variants in alpha-actinin can cause inherited conditions, e.g. myopathies and cardiomyopathies. The underlying disease mechanisms are still unknown.

Purpose

In order to study the disease mechanisms of an alpha-actinin missense variant, which is known to cause Hypertrophic Cardiomyopathy in human patients, a mouse model was generated.

Methods

Mice carrying the alpha-actinin missense variant were generated by CRISPR-Cas9 genome editing. The heterozygous adult mice carrying the alpha-actinin variant were characterised by echocardiography and quantitative PCR. Hearts of homozygous embryos were analysed at E15.5 by high-resolution episcopic microscopy (HREM).

Results

Mice carrying a single copy of the missense variant were viable and had normal appearance. Adult heterozygous mice showed no signs of cardiomyopathy on echocardiography. However, mature male mice displayed molecular signs of cardiomyopathy, such as induction of the fetal gene programme at transcript level.

The attempt to generate adult mice homozygous for the variant failed: 9 breeding pairs produced 18 litters with 83 weaned pups, but no homozygous offspring. Embryonic lethality was confirmed and E15.5 was the latest stage homozygous pups were reliably found to be viable. At this timepoint, genotype distribution was within the expected Mendelian ratios.

HREM of the hearts at this stage revealed increased right ventricular chamber size and decreased left atrial size, when compared to wildtype littermates. Membranous ventricular septal defects were observed in 3 out of 8 homozygous hearts. Further these embryos displayed aortic stenosis and dysplasic leaflets of the pulmonary valve.

Conclusions

Heterozygous adult mice only displayed sub-clinical signs of disease. In contrast, the missense variant is embryonic lethal in the homozygous setting and leads to a range of morphological abnormalities in E15.5 hearts. Future work will identify how altered functions of alpha-actinin cause these changes.

Yak miR-2285o-3p attenuates hypoxia-induced apoptosis by targeting caspase-3

miRNAs are a class of hairpin‐derived RNAs, 21–24 nucleotides in length, which are involved in a range of biological processes. The bta‐miR‐2285 family has over 40 members spanning the entire bovine genome. We previously found that bta‐miR‐2285o‐3p was highly expressed in yak heart and lung when compared with cattle, which prompted us to investigate its potential function in high‐altitude adaptation of yaks. In this study, we detected wide‐spread high expression of bta‐miR‐2285o‐3p in yak tissues. Further experiments revealed that the protein tyrosine phosphatase receptor type M (PTPRM) gene was the host gene of bta‐miR‐2285o‐3p and that two linked SNPs in bta‐mir‐2285o precursor affected the biogenesis of mature miRNA (bta‐miR‐2285o‐3p). Functional analysis in vitro indicated that bta‐miR‐2285o‐3p attenuated hypoxia‐induced apoptosis by targeting very low‐density lipoprotein receptor (VLDLR), phosphatase and tensin homolog (PTEN) and caspase‐3. Expression level analysis in vivo revealed the high negative Pearson’s correlation between bta‐miR‐2285o‐3p and caspase3 in yak, highlighting the potential important roles of bta‐miR‐2285o‐3p in yak high‐altitude adaptation. Our study provides a typical model for deciphering the function of miRNAs in environmental adaptation.

Parsing the microRNA genetics basis regulating skeletal muscle fiber types and meat quality traits in pigs

Muscle fibers are closely related to human diseases and livestock meat quality. However, the genetics basis of microRNAs (miRNAs) in regulating muscle fibers is not completely understood. In this study, we constructed the whole genome-wide miRNA expression profiles of porcine fast-twitch muscle [biceps femoris (Bf)] and slow-twitch muscle [soleus (Sol)], and identified hundreds of miRNAs, including four skeletal muscle-highly expressed miRNAs, ssc-miR-378, ssc-let-7f, ssc-miR-26a, and ssc-miR-27b-3p. Moreover, we identified 63 differentially expressed (DE) miRNAs between biceps femoris vs. soleus, which are the key candidate miRNAs regulating the skeletal muscle fiber types. In addition, we found that the expression of DE ssc-miR-499-5p was significantly correlated to the expression of Myoglobin (r = 0.6872, P < 0.0001) and Myosin heavy chain 7 (MYH7; r = 0.5408, P = 0.0020), and pH_45 min (r = 0.3806, P = 0.0380) and glucose content (r = -0.4382, P = 0.0154); while the expression of DE ssc-miR-499-3p was significantly correlated to the expression of Myoglobin (r = 0.5340, P = 0.0024) and pH_45 min (r = 0.4857, P = 0.0065). Taken together, our data established a sound foundation for further studies on the regulatory mechanisms of miRNAs in skeletal muscle fiber conversion and meat quality traits in livestock, and could provide a genetic explanation of the role of miRNAs in human muscular diseases.

Effect of salt concentration on microbial communities, physicochemical properties and metabolite profile during spontaneous fermentation of Chinese northeast sauerkraut

AIM

The aim of this study was to study the effects of salt concentrations on the microbial communities, physicochemical properties, metabolome profiles and sensory characteristics during the fermentation of traditional northeast sauerkraut.

METHODS AND RESULTS

Northeast sauerkraut was spontaneously fermented under four salt concentrations (0·5, 1·5, 2·5 and 3·5%, w/w). The result of microbiological analysis showed that the population of lactic acid bacteria in 2·5%-salted sauerkraut was significantly higher than that in the other samples. Correspondingly, the speed of decrease in pH and accumulation of acids were the highest in 2·5%-salted sauerkraut. The glucose (analysed by HPLC) in 2·5%-salted sauerkraut was consumed more completely to produce higher levels of organic acids compared to those in the other samples. Principle component analysis showed clear differences in the metabolites of sauerkraut according to different salt concentrations. A higher level of volatiles (detected by HS-SPME/GC-MS) was identified in 2·5%-salted sauerkraut, and sensory evaluation demonstrated that 2·5%-salted sauerkraut had the best sensory characteristics.

CONCLUSION

The best quality of sauerkraut was obtained from fermented under 2·5% salt concentration.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study facilitated the understanding of the effects of salt on the sauerkraut fermentation and may be useful for developing the quality of sauerkraut.

Radial contractility of actomyosin rings facilitates axonal trafficking and structural stability

Most mammalian neurons have a narrow axon, which constrains the passage of large cargoes such as autophagosomes that can be larger than the axon diameter. Radial axonal expansion must therefore occur to ensure efficient axonal trafficking. In this study, we reveal that the speed of various large cargoes undergoing axonal transport is significantly slower than that of small ones and that the transit of diverse-sized cargoes causes an acute, albeit transient, axonal radial expansion, which is immediately restored by constitutive axonal contractility. Using live super-resolution microscopy, we demonstrate that actomyosin-II controls axonal radial contractility and local expansion, and that NM-II filaments associate with periodic F-actin rings via their head domains. Pharmacological inhibition of NM-II activity significantly increases axon diameter by detaching the NM-II from F-actin and impacts the trafficking speed, directionality, and overall efficiency of long-range retrograde trafficking. Consequently, prolonged NM-II inactivation leads to disruption of periodic actin rings and formation of focal axonal swellings, a hallmark of axonal degeneration.

[Application of next generation sequencing in congenital sensorineural deafness]

Objective:The next-generation sequencing technology (NGS) was used to perform genetic testing on children diagnosed with sensorineural hearing loss in outpatient clinics.The information on the status and inheritance of disease causing genes in deafness was analyzed to provide a theoretical basis for genetic counseling, prenatal diagnosis, and birth defects prevention.Method:Ninety-four cases of sensorineural deafness diagnosed by medical history, audiological examination, and imaging examination were collected in our department.Next-generation sequencing was used to detect the region of exons of 159 genes, 6 mitochondrial genes, and 3 miRNAs related to deafness. The Sanger sequencing verification was performed on the parents of the probands to find out the gene expression status and relationship between the probands and the parents.Result:Of the 94 children with deafness,70 had severe sensorineural hearing loss, 13 had moderate to severe hearing loss, 8 had moderate hearing loss, and 3 had mild hearing loss.Twenty-three cases of cariogenic mutations were detected by next generation sequencing,and the total mutation rate was 24.5%. There were 11 cases of GJB2 mutations, including 6 homozygous mutations of 235delC, 4 heterozygous mutations of 235delC and 299_300del heterozygous mutation of 235delC and c.176_191del.There are 5 cases of SLC26A4 gene mutations, including 2 cases of homozygous mutations of c.919-2A> G, one case of c.919-2A> G and c.2168A>G compound heterozygous mutations, c.919-2A> G and c.754T> C compound heterozygous mutation in 1 case, c.919 2A> G and c.416-418del complex heterozygous mutation in 1 case. There were 2 cases of MT RNR1 mutations, and 1 case of STRC,KCNQ1,USH2A,POU3F4, and MITF mutations.Conclusion:The next-generation sequencing has features such as rapid, high throughput, and low cost, which is beneficial to medication guidance, genetic counseling, and marriage and parenting guidance,and help to effectively prevent or reduce the occurrence of hereditary deafness..

Effects of a galacto-oligosaccharide-rich diet on fecal microbiota and metabolite profiles in mice

Galacto-oligosaccharides (GOS) are prebiotics that positively affect the host's gut microbiota, which is important for the health of the host.

[Study on the recent application of ear correction model in children with congenital auricular deformity]

Objective:To study the short-term effect of Earwell ear correction model on congenital auricular deformity in children. Method:Selected 38 children with ear malformation, a total of 42 ears, born at the age of 7 days to 176 days, and the average age was 62.40 days, and all of patients were used the U.S. Earwell correction model for correction. Result:Final auricular morphologic results were classified as excellent (normal shape), good (nearnormal shape), and poor (slight or no improvement). And the patients were divided into group 1 (neonatal period), group 2 (28-90 days) and group 3 (more than 90 days) according to age, after using the Earwell ear correction device, the result which evaluated excellent are 100.00%, 89.47% and 72.73% respectively, and the average correction times are 16.75 days, 26.26 days and 38.91 days respectively, the ratio of complications are 0, 73.68% and 100.00% respectively. Conclusion:The effection of Earwell ear correction model is significant for the correction of children with congenital auricular deformity , the earlier treatment cause the better result, the shorter of the correcting time , and the lower of the complication rate.

Psychiatric and behavioral side effects of anti-epileptic drugs in adolescents and children with epilepsy

PURPOSE

The objective of the study was to compare the psychiatric and behavioral side effect (PBSE) profiles of both older and newer antiepileptic drugs (AEDs) in children and adolescent patients with epilepsy.

METHOD

We used logistic regression analysis to test the correlation between 83 non-AED/patient related potential predictor variables and the rate of PBSE. We then compared for each AED the rate of PBSEs and the rate of PBSEs that led to intolerability (IPBSE) while controlling for non-AED predictors of PBSEs.

RESULTS

922 patients (≤18 years old) were included in our study. PBSEs and IPBSEs occurred in 13.8% and 11.2% of patients, respectively. Overall, a history of psychiatric condition, absence seizures, intractable epilepsy, and frontal lobe epilepsy were significantly associated with increased PBSE rates. Levetiracetam (LEV) had the greatest PBSE rate (16.2%). This was significantly higher compared to other AEDs. LEV was also significantly associated with a high rate of IPBSEs (13.4%) and dose-decrease rates due to IPBSE (6.7%). Zonisamide (ZNS) was associated with significantly higher cessation rate due to IPBSE (9.1%) compared to other AEDs.

CONCLUSION

Patients with a history of psychiatric condition, absence seizures, intractable epilepsy, or frontal lobe epilepsy are more likely to develop PBSE. PBSEs appear to occur more frequently in adolescent and children patients taking LEV compared to other AEDs. LEV-attributed PBSEs are more likely to be associated with intolerability and subsequent decrease in dose. The rate of ZNS-attributed IPBSEs is more likely to be associated with complete cessation of AED.

Protective effects of salidroside against isoflurane-induced cognitive impairment in rats

Postoperative cognitive dysfunction, which is associated with a wide range of cognitive functions including working memory, long-term memory, information processing, attention, and cognitive flexibility, is a major clinical issue in geriatric surgical patients. The aim of the current study was to determine the protective role and possible mechanisms of salidroside against isoflurane-induced cognitive impairment. Sprague Dawley rats were randomly assigned to five groups and were treated with or without salidroside before isoflurane exposure. Open-field and fear conditioning tests were conducted to evaluate the cognitive function of the rats. Moreover, the hippocampus tissues were obtained for biochemical analysis. The results showed that the isoflurane anesthesia decreased the freezing time to context significantly at 48 h after the isoflurane exposure in the fear conditioning test. Salidroside could ameliorate isoflurane-induced cognitive dysfunction. Further analysis demonstrated salidroside markedly suppressed the release of tumor necrosis factor-α and interleukin-1β. Moreover, salidroside reversed the decreased activity of choline acetyltransferase, superoxide dismutase, glutathione peroxidase, and content of acetylcholine, as well as the increased activity of acetylcholine esterase and content of malondialdehyde in hippocampal tissue of isoflurane-exposed rats. According to the results, we concluded that that salidroside has a protective effect against isoflurane-induced cognitive dysfunction by inhibiting excessive inflammatory responses, decreasing oxidative stress, and regulating the cholinergic system.

Human Lysozyme Synergistically Enhances Bactericidal Dynamics and Lowers the Resistant Mutant Prevention Concentration for Metronidazole to Helicobacter pylori by Increasing Cell Permeability

Metronidazole (MNZ) is an effective agent that has been employed to eradicate Helicobacter pylori (H. pylori). The emergence of broad MNZ resistance in H. pylori has affected the efficacy of this therapeutic agent. The concentration of MNZ, especially the mutant prevention concentration (MPC), plays an important role in selecting or enriching resistant mutants and regulating therapeutic effects. A strategy to reduce the MPC that can not only effectively treat H. pylori but also prevent resistance mutations is needed. H. pylori is highly resistant to lysozyme. Lysozyme possesses a hydrolytic bacterial cell wall peptidoglycan and a cationic dependent mode. These effects can increase the permeability of bacterial cells and promote antibiotic absorption into bacterial cells. In this study, human lysozyme (hLYS) was used to probe its effects on the integrity of the H. pylori outer and inner membranes using as fluorescent probe hydrophobic 1-N-phenyl-naphthylamine (NPN) and the release of aspartate aminotransferase. Further studies using a propidium iodide staining method assessed whether hLYS could increase cell permeability and promote cell absorption. Finally, we determined the effects of hLYS on the bactericidal dynamics and MPC of MNZ in H. pylori. Our findings indicate that hLYS could dramatically increase cell permeability, reduce the MPC of MNZ for H. pylori, and enhance its bactericidal dynamic activity, demonstrating that hLYS could reduce the probability of MNZ inducing resistance mutations.

Resveratrol Protects against Helicobacter pylori-Associated Gastritis by Combating Oxidative Stress

Helicobacter pylori (H. pylori)-induced oxidative stress has been shown to play a very important role in the inflammation of the gastric mucosa and increases the risk of developing gastric cancer. Resveratrol has many biological functions and activities, including antioxidant and anti-inflammatory effect. The purpose of this study was to probe whether resveratrol inhibits H. pylori-induced gastric inflammation and to elucidate the underlying mechanisms of any effect in mice. A mouse model of H. pylori infection was established via oral inoculation with H. pylori. After one week, mice were administered resveratrol (100 mg/kg body weight/day) orally for six weeks. The mRNA and protein levels of iNOS and IL-8 were assessed using RT-PCR, Western blot and ELISA. The expression levels of IκBα and phosphorylated IκBα (which embodies the level and activation of NF-κB), Heme Oxygenase-1 (HO-1; a potent antioxidant enzyme) and nuclear factor-erythroid 2 related factor 2 (Nrf2) were determined using Western blot, and lipid peroxide (LPO) level and myeloperoxidase (MPO) activity were examined using an MPO colorimetric activity assay, thiobarbituric acid reaction, and histological-grade using HE staining of the gastric mucosa. The results showed that resveratrol improved the histological infiltration score and decreased LPO level and MPO activity in the gastric mucosa. Resveratrol down-regulated the H. pylori-induced mRNA transcription and protein expression levels of IL-8 and iNOS, suppressed H. pylori-induced phosphorylation of IκBα, and increased the levels of HO-1 and Nrf2. In conclusion, resveratrol treatment exerted significant effects against oxidative stress and inflammation in H. pylori-infected mucosa through the suppression of IL-8, iNOS, and NF-κB, and moreover through the activation of the Nrf2/HO-1 pathway.

Combined low dose local anesthetics and opioids versus single use of LA for transurethral urological surgery: a meta-analysis

INTRODUCTION

The combination of reduced dose of local anesthetics (LA) and highly lipid-soluble synthetic opioids for patients undergoing transurethral surgery could reduce block duration and side-effects. However, it remains unclear what are the most appropriate levels of low dose and the extent to which the side-effects could be controlled. A meta-analysis was conducted to address this concern.

MATERIALS AND METHODS

Based on twelve randomized controlled trials, this meta-analysis pooled previous results to generate integrated evidence.

RESULTS

Combined low dose of LA and opioids had similar sensory block and significantly shorter motor block duration (weighted mean difference: -39.31 min, 95% confidence interval (CI): -50.58--28.05, P < 0.00001) compared with single use of LA. There was no evidence of higher risk of analgesic failure in the combination group. In addition, combined low dose LA and opioids was associated with significantly reduced rate of postoperative hypotension (risk ratios (RR): 0.60, 95% CI: 0.37-0.96, P = 0.03) and shivering (RR: 0.27, 95% CI: 0.11-0.64, P = 0.003), but with higher rate of sedation (RR: 3.14, 95% CI: 1.02-9.66, P = 0.05).

CONCLUSION

Combined low dose LA and opioids is a better choice for patients received transurethral surgery compared with single use of intrathecal LA.

Purification and identification of five novel antioxidant peptides from goat milk casein hydrolysates

The present research described the preparation, purification, and identification of antioxidant peptides from goat milk casein (GMC). Goat milk casein was hydrolyzed by using a combination of neutral and alkaline proteases to obtain goat milk casein hydrolysates (GMCH) with high antioxidant activity. After desalting by nonpolar macroporous absorption resin, GMCH was isolated and purified by gel filtration chromatography and reversed-phase HPLC, respectively, and further identified by nanoliter electrospray ionization-tandem mass spectrometry. Antioxidant activities of GMC, GMCH, and pure peptides were evaluated and compared using free radical scavenging activity, metal ion chelating ability, and anti-lipid peroxidation ability. Compared with GMC, the free radical-scavenging ability and ferrous ion-chelating ability of GMCH increased significantly. The inhibition effect of lipid peroxidation of GMCH was much stronger than that of tert-butylhydroquinone and phytogermine and a little lower than that of ascorbic acid. The antioxidant activity of GMCH could be attributed to the high antioxidant activity of oligopeptides, especially 5 novel oligopeptides: Val-Tyr-Pro-Phe, Phe-Gly-Gly-Met-Ala-His, Phe-Pro-Tyr-Cys-Ala-Pro, Tyr-Val-Pro-Glu-Pro-Phe, and Tyr-Pro-Pro-Tyr-Glu-Thr-Tyr, which were first observed in GMCH. The antioxidant activity of these 5 novel oligopeptides and GMCH increased 3.59 to 380 times compared with GMC, combining anti-lipid peroxidation ability of GMCH, which indicated that GMCH and its purified fractions in different stages could be used as functional food ingredients, food additives, and pharmaceutical agents in the future.

Regulatory T cell expression of CLA or α(4)β(7) and skin or gut acute GVHD outcomes

Regulatory T cells (Tregs) are a suppressive subset of CD4(+) T lymphocytes implicated in the prevention of acute GVHD (aGVHD) after allo-SCT (ASCT). To determine whether increased frequency of Tregs with a skin-homing (cutaneous lymphocyte Ag, CLA(+)) or a gut-homing (α(4)β(7)(+)) phenotype is associated with reduced risk of skin or gut aGVHD, respectively, we quantified circulating CLA(+) or α(4)β(7)(+) on Tregs at the time of neutrophil engraftment in 43 patients undergoing ASCT. Increased CLA(+) Tregs at engraftment was associated with the prevention of skin aGVHD (2.6 vs 1.7%; P=0.038 (no skin aGVHD vs skin aGVHD)), and increased frequencies of CLA(+) and α(4)β(7)(+) Tregs were negatively correlated with severity of skin aGVHD (odds ratio (OR), 0.67; 95% confidence interval (CI), 0.46-0.98; P=0.041) or gut aGVHD (OR, 0.93; 95% CI, 0.88-0.99; P=0.031), respectively. This initial report suggests that Treg tissue-homing subsets help to regulate organ-specific risk and severity of aGVHD after human ASCT. These results need to be validated in a larger, multicenter cohort.

Clinical features of atopic dermatitis in a hospital-based setting in China

BACKGROUND

Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease. There have been few detailed reports of the clinical evaluation of Chinese patients with AD.

OBJECTIVES

To give a profile of the clinical features of Chinese AD patients in a university hospital setting.

METHODS

A total of 1008 cases met Hanifin and Rajka diagnostic criteria of AD were recruited at Xinhua Hospital, Shanghai Jiaotong University School of Medicine, China.

RESULTS

In our survey, 22.7% patients were mild, 66.6% were moderate and 10.7% were severe according to the SCORAD index. Both the frequency and severity of the male patients were slightly higher. The frequency of asthma among the AD patients was 16.7% and it was increased with the age (χ2 = 205.20, P = 0.000). The frequencies of objective minor signs were demonstrated with age-related changes. Besides, three localized variants including eyelid eczema (49.8%), scalp dermatitis (49.7%), infra-auricular and retroauricular fissuring (44.8%) were commonly observed, especially in the infantile phase (P < 0.01). It was showed significant differences in serum total immunoglobulin E (IgE) and eosinophil cationic protein (ECP) levels of different age groups. The positive rate of Phadiatop was raised after 3 years old and that of the common food allergens were decreased after 6 years old.

CONCLUSIONS

More males than females had ongoing AD in our survey. Most AD debuted in the first year of the cases. High incidence of the three clinical signs: eyelid eczema, scalp dermatitis and infra-auricular and retroauricular fissuring among the patients suggests it can be a potential valuable diagnostic clue to AD.

DNA copy number aberrations in small-cell lung cancer reveal activation of the focal adhesion pathway

Small-cell lung cancer (SCLC) is the most aggressive subtype of lung cancer in its clinical behavior, with a 5-year overall survival as low as 5%. Despite years of research in the field, molecular determinants of SCLC behavior are still poorly understood, and this deficiency has translated into an absence of specific diagnostics and targeted therapeutics. We hypothesized that tumor DNA copy number alterations would allow the identification of molecular pathways involved in SCLC progression. Array comparative genomic hybridization was performed on DNA extracted from 46 formalin-fixed paraffin-embedded SCLC tissue specimens. Genomic profiling of tumor and sex-matched control DNA allowed the identification of 70 regions of copy number gain and 55 regions of copy number loss. Using molecular pathway analysis, we found a strong enrichment in these regions of copy number alterations for 11 genes associated with the focal adhesion pathway. We verified these findings at the genomic, gene expression and protein level. Focal Adhesion Kinase (FAK), one of the central genes represented in this pathway, was commonly expressed in SCLC tumors and constitutively phosphorylated in SCLC cell lines. Those were poorly adherent to most substrates but not to laminin-322. Inhibition of FAK phosphorylation at Tyr(397) by a small-molecule inhibitor, PF-573,228, induced a dose-dependent decrease of adhesion and an increase of spreading in SCLC cell lines on laminin-322. Cells that tended to spread also showed a decrease in focal adhesions, as demonstrated by a decreased vinculin expression. These results support the concept that pathway analysis of genes in regions of copy number alterations may uncover molecular mechanisms of disease progression and demonstrate a new role of FAK and associated adhesion pathways in SCLC. Further investigations of FAK at the functional level may lead to a better understanding of SCLC progression and may have therapeutic implications.

Loss of PTEN engages ErbB3 and IGF-I receptor signaling to promote antiestrogen resistance in breast cancer

Abstract #73

We sought to determine whether loss of the lipid phosphatase PTEN confers resistance to antiestrogens in estrogen receptor (ER)-positive breast cancer cells and primary tumors. Stable knockdown of PTEN expression (PTEN-kd) with shRNA in MCF-7, T47D, and MDA-361 ER+ human breast cancer cells resulted in upregulation of PI3K and P-Akt, resistance to tamoxifen and faslodex, and estrogen-independent growth. Upon PTEN-kd, ER levels were maintained in MCF-7 cells but markedly reduced in T47D and MDA-361 cells. While PTEN-kd upregulated ER transcriptional reporter activity in MCF-7 cells, opposite effects were seen in T47D and MDA-361 cells.&#x2028; We evaluated mechanisms of PI3K activation in PTEN-kd cells by immunoprecipitating the p85 regulatory subunit of PI3K and examining p85-bound tyrosine-phosphorylated adaptors or receptors. PTEN-kd increased the binding of p85 to IRS-1 (MCF-7) and ErbB3 (T47D). PTEN-kd increased PI3K pathway sensitivity to IGF-I (MCF-7) and endogenous ligand (T47D, MDA-361). PTEN-kd cells had increased and prolonged activation of IGF-IR and ErbB3, thus implicating PTEN in the regulation of signaling upstream of PI3K. Further, PTEN-kd increased non-genomic, estrogen-induced signaling via IGF-IR by increasing p85-IRS-1 binding and activation of PI3K/Akt in MCF-7 cells. Inhibition of PI3K and mTOR with the small molecule BEZ235, of IGF-IR with the small molecule AEW541, and/or of ErbB2-mediated activation of ErbB3 with lapatinib restored the growth inhibitory effect of antiestrogens.&#x2028; We generated gene expression signatures of PTEN loss in each cell line by microarray analyses. Comparison of these signatures to the Connectivity Map (Science 313:1929, 2006) suggested activation of PI3K, as signatures of PTEN loss negatively connected with those induced by the PI3K inhibitors wortmannin and LY294002 (all p&lt;0.06). We found a 24-gene signature of PTEN loss common to all 3 lines, which we used to score the gene expression profiles of tumors from a cohort of 268 patients with ER+ breast cancer treated with adjuvant tamoxifen for 5 yrs and a median follow-up of 9.1 years (BMC Genomics 9:239, 2008). Patients with tumors exhibiting a signature of PTEN loss had shorter relapse-free survival (p&lt;0.0001; log rank test). Eleven genes in the PTEN signature were individually predictive of disease outcome (p&lt;0.05). In a separate, smaller cohort of patients with ER+ cancers treated with adjuvant tamoxifen (n=34), undetectable PTEN in tumor cells (measured by IHC) correlated with shorter relapse-free survival vs. tumors with detectable PTEN (p=0.06). These data suggest that 1) PTEN loss confers antiestrogen resistance to ER+ breast cancer by genomic and non-genomic mechanisms; 2) PTEN loss is permissive for activation of IGF-IR and ErbB3 signaling; 3) inhibition of IGF-IR and/or ErbB signaling pathways overcomes the resistance to antiestrogens conferred by PTEN loss; and 4) a gene expression signature reflective of loss of PTEN and/or absence of PTEN protein can predict poor patient outcome after adjuvant hormonal therapy.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 73.

The Notch pathway mediates expansion of a progenitor pool and neuronal differentiation in adult neural progenitor cells after stroke

Molecular mechanisms by which stroke increases neurogenesis have not been fully investigated. Using neural progenitor cells isolated from the subventricular zone (SVZ) of the adult rat subjected to focal cerebral ischemia, we investigated the Notch pathway in regulating proliferation and differentiation of adult neural progenitor cells after stroke. During proliferation of neural progenitor cells, ischemic neural progenitor cells exhibited substantially increased levels of Notch, Notch intracellular domain (NICD), and hairy enhancer of split (Hes) 1, which was associated with a significant increase of proliferating cells. Blockage of the Notch pathway by short interfering ribonucleic acid (siRNA) against Notch or a gamma secretase inhibitor significantly reduced Notch, NICD and Hes1 expression and cell proliferation induced by stroke. During differentiation of neural progenitor cells, Notch and Hes1 expression was downregulated in ischemic neural progenitor cells, which was coincident with a significant increase of neuronal population. Inhibition of the Notch pathway with a gamma secretase inhibitor further substantially increased neurons, but did not alter astrocyte population in ischemic neural progenitor cells. These data suggest that the Notch signaling pathway mediates adult SVZ neural progenitor cell proliferation and differentiation after stroke.

Reduced carbon solubility in Fe nanoclusters and implications for the growth of single-walled carbon nanotubes

Fe nanoclusters are becoming the standard catalysts for growing single-walled carbon nanotubes via chemical vapor decomposition. Contrary to the Gibbs-Thompson model, we find that the reduction of the catalyst size requires an increase of the minimum temperature necessary for the growth. We address this phenomenon in terms of solubility of C in Fe nanoclusters and, by using first-principles calculations, we devise a simple model to predict the behavior of the phases competing for stability in Fe-C nanoclusters at low temperature. We show that, as a function of particle size, there are three scenarios compatible with steady state growth, limited growth, and no growth of single-walled carbon nanotubes, corresponding to unaffected, reduced, and no solubility of C in the particles.

Novel magnetic rings for rapid vascular reconstruction in canine liver transplantation model

OBJECTIVE

Magnetic rings were used for rapid vascular reconstruction in a canine liver transplantation model.

MATERIALS AND METHODS

Thirty-two adult mongrel dogs weighing 13 to 16 kg were randomly selected as donors or recipients of transplantations. The recipients were randomly divided into two groups: group A (n = 10) had magnetic rings used for vascular reconstruction without venovenous bypass; group B (n = 6) had vascular reconstruction performed by continuous suturing with splenojugular venovenous bypass.

RESULTS

In group A, the entire operative period was 3.24 +/- 0.49 hours, the durations of clamping the portal vein and the infrahepatic vena cava of the recipient were 5.89 +/- 2.27 minutes and 3.89 +/- 0.73 minutes, respectively. In group B, the entire operative period was 4.12 +/- 0.51 hours with the duration of clamping portal vein and infrahepatic vena cava, 28.33 +/- 6.04 minutes and 12.16 +/- 3.72 minutes (P < .01 vs group A). In group A, mean arterial pressure dropped during the anhepatic phase but recovered quickly after reperfusion. The fluid infusion was about 730.56 +/- 50.56 mL in the group A and a pressor agent was unnecessary. In group B, blood pressure dropped during the anhepatic phase and slowly recovered. The fluid infusion was about 2241.67 +/- 390.78 mL and a pressor agent was used to maintain the blood pressure of the recipient. No twist or thrombus was discovered in the anastomoses group A and the endothelium at the site of anastomosis was entire. In group B, errhysis was common in the anastomotic stomas. Nine of 10 dogs in group A survived more than 3 days, the longest being 8 days, whereas four of the six dogs in group B survived less than 3 days.

CONCLUSION

The results showed that the anhepatic time was significantly shortened (about 5.89 +/- 2.27 minutes) in group A compared with group B and venovenous bypass was unnecessary. Magnetic rings could be used for rapid vascular reconstruction in canine liver transplantation model. The long-term results of this procedure should be clarified before it is applied in clinical practice in the future.

Efficiencies of residual organic pollutants removal from secondary effluent by switching of coagulation- air flotation -filtration processes

It is an essential task to remove the residual organic pollutants (ROP) from secondary effluent of a Wastewater Treatment Plant (WWTP) in wastewater reclamation and reuse processes. Four different compared flow schemes would be achieved for further purification of the secondary effluent by switching of different valves. In order to mainly remove non-biodegradable residual organic pollutants under various operating conditions, the optimum technology and economic process was obtained in the advanced purification flow scheme at a flow of 3200 m(3)/d in Harbin Wenchang WWTP. Conclusions under a lot of experiments show that: choosing the coagulation-settler plus biofilm filter for advanced purification process is reasonable; during the stable operation phase, this process showed good performance in removing the COD, BOD5, TP, NH3-N and SS; the removal rates are 50%, 39%, 67%, 50%, 80% respectively. The effluent is able to excel the requirements for wastewater reuse standards. The unit cost of the water is 0.542 yuan/m(3), which is far below the fee paid for supply water, long-distance transfer water or seawater desalination through economic analysis.