Combination of targeted daunorubicin liposomes and targeted emodin liposomes for treatment of invasive breast cancer

Conventional treatment fails to completely eliminate highly invasive breast cancer cells, and most surviving breast cancer cells tend to reproliferate and metastasize by forming vasculogenic mimicry (VM) channels. Thus, a type of targeted liposomes was developed by modification with arginine₈-glycine-aspartic acid (R₈GD) to encapsulate daunorubicin and emodin separately. A combination of the two targeted liposomes was then developed to destroy VM channels and inhibit tumour metastasis. MDA-MB-435S cells, a highly invasive breast cancer, were then evaluated in vitro and in mice. The experiments indicated that R₈GD modified daunorubicin liposomes plus R₈GD modified emodin liposomes had small particle size, uniform particle size distribution and high drug encapsulation rate. The combination of the two targeted liposomes exerted strong toxicity on the MDA-MB-435S cells and effectively inhibited the formation of VM channels and the metastasis of tumour cells. Action mechanism studies showed that the R₈GD modified daunorubicin liposomes plus R₈GD modified emodin liposomes could downregulate some metastasis-related proteins, including MMP-2, VE-cad, TGF-β1 and HIF-1α. These studies also demonstrated that the targeted liposomes allowed the chemotherapeutic drug to selectively accumulate at tumour site, thus exhibiting a distinct antitumor effect. Therefore, the combination of targeted daunorubicin liposomes and targeted emodin liposomes can provide a potential treatment for invasive breast cancer.

TIGAR Attenuates High Glucose-Induced Neuronal Apoptosis via an Autophagy Pathway

Hyperglycemia-induced neuronal apoptosis is one of the important reasons for diabetic neuropathy. Long-time exposure to high glucose accelerates many aberrant glucose metabolic pathways and eventually leads to neuronal injury. However, the underlying mechanisms of metabolic alterations remain unknown. TP53-inducible glycolysis and apoptosis regulator (TIGAR) is an endogenous inhibitor of glycolysis and increases the flux of pentose phosphate pathway (PPP) by regulating glucose 6-phosphate dehydrogenase (G6PD). TIGAR is highly expressed in neurons, but its role in hyperglycemia-induced neuronal injury is still unclear. In this study, we observed that TIGAR and G6PD are decreased in the hippocampus of streptozotocin (STZ)-induced diabetic mice. Correspondingly, in cultured primary neurons and Neuro-2a cell line, stimulation with high glucose induced significant neuronal apoptosis and down-regulation of TIGAR expression. Overexpression of TIGAR reduced the number of TUNEL-positive neurons and prevented the activation of Caspase-3 in cultured neurons. Furthermore, enhancing the expression of TIGAR rescued high glucose-induced autophagy impairment and the decrease of G6PD. Nitric oxide synthase 1 (NOS1), a negative regulator of autophagy, is also inhibited by overexpression of TIGAR. Inhibition of autophagy abolished the protective effect of TIGAR in neuronal apoptosis in Neuro-2a. Importantly, overexpression of TIGAR in the hippocampus ameliorated STZ-induced cognitive impairment in mice. Therefore, our data demonstrated that TIGAR may have an anti-apoptosis effect via up-regulation of autophagy in diabetic neuropathy.

Chitin synthase is involved in vegetative growth, asexual reproduction and pathogenesis of Phytophthora capsici and Phytophthora sojae

Chitin is a structural and functional component of the fungal cell wall and also serves as a pathogen-associated molecular pattern (PAMP) that triggers the innate immune responses of host plants. However, no or very little chitin is found in the fungus-like oomycetes. In Phytophthora spp., the presence of chitin has not been demonstrated so far, although putative chitin synthase (CHS) genes, which encode the enzymes that synthesize chitin, are present in their genomes. Here, we revealed that chitin is present in the zoospores and released sporangia of Phytophthora, and this is most consistent with the transcriptional pattern of PcCHS in Phytophthora capsici and PsCHS1 in Phytophthora sojae. Disruption of the CHS genes indicated that PcCHS and PsCHS1, but not PsCHS2 (which exhibited very weak transcription), have similar functions involved in mycelial growth, sporangial production, zoospore release and the pathogenesis of P. capsici and P. sojae. We also suggest that chitin in the zoospores of P. capsici can act as a PAMP that is recognized by the chitin receptors AtLYK5 or AtCERK1 of Arabidopsis. These results provide new insights into the biological significance of chitin and CHSs in Phytophthora and help with the identification of potential targets for disease control.

Osthole alleviates inflammation by down-regulating NF-κB signaling pathway in traumatic brain injury

Traumatic brain injury (TBI) is a common neurotrosis disorder of the central nervous system (CNS), which has dramatic consequences on the integrity of damaged tissue. In this study, we investigated the neuroprotective effect and anti-inflammatory actions of osthole, a natural coumarin derivative, in both in vivo and in vitro TBI models. We first prepared a mouse model of cortical stab wound brain injury, investigated the capacity for osthole to prevent secondary brain injury and further examined the underlying mechanism. We revealed that osthole significantly improved the neurological function, increased the number of neurons beside injured site. Additionally, osthole treatment reduced the expression of microglia and glial scar, lowered the level of the proinflammatory cytokines interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α), and blocked the activation of nuclear factor kappa B (NF-κB). Furthermore, the protective effect of osthole was also examined in SH-SY5Y cells subjected to scratch injury. Treatment of osthole prominently suppressed cell apoptosis and inflammatory factors release by blocking injury-induced IκB-α phosphorylation and NF-κB translocation, and upregulated the IκB-α which functions in the NF-κB signaling pathway of SH-SY5Y cells. However, NF-κB signaling pathway was inhibited by pyrrolidine dithiocarbamate (PDTC), an NF-κB inhibitor, the anti-inflammatory effect of osthole was abolished. In conclusion, our findings demonstrated that osthole attenuated inflammatory response by inhibiting the NF-κB pathway in TBI.

Novel homozygous nonsense mutations in LHCGR lead to empty follicle syndrome and 46, XY disorder of sex development

Empty follicle syndrome (EFS) is a disorder associated with female infertility and presents as a complete failure to retrieve oocytes during ART cycles despite normal follicle development and careful aspiration. To date, only two EFS cases have been reported with homozygous missense mutations in the luteinizing hormone/chorionic gonadotropin receptor (LHCGR) gene, and both cases showed normal estradiol (E2) production during ovulation induction. The molecular genetic mechanisms of EFS remain unknown. Herein, we report two novel homozygous inactivating LHCGR mutations, c.736 C>T (p.Q246*) and c.846dupT (p.R283*), in two female EFS patients from unrelated consanguineous families. The probands had impaired E2 production during the ART process, which differs from previously reported EFS cases. The inactivating mutations not only led to EFS in the two female probands, but also resulted in 46, XY disorder of sex development (46, XY DSD) in their male siblings. As far as we know, this is the first report of LHCGR mutations leading to both EFS and 46, XY DSD within the same pedigree. Our findings provide researchers and clinicians with a better understanding of phenotype-genotype correlations between EFS and 46, XY DSD and the LHCGR gene.

An ensemble method for multi-type Gram-negative bacterial secreted protein prediction by integrating different PSSM-based features

In Gram-negative bacteria, a wide range of proteins are secreted by highly specialized secretion systems. These secreted proteins play essential roles in the response of bacteria to their environment and also in several physiological processes such as adhesion, pathogenicity, adaptation and survival. Therefore, identifying secreted proteins in Gram-negative bacteria may assist in understanding the secretion mechanism and development of new antimicrobial strategies. Considering that a single-feature model is less likely to comprehensively cover this information, three kinds of feature models were used in this paper to represent protein samples by composition analysis, correlation analysis and smoothing encoding method on position-specific scoring matrix profiles. A support vector machine-based ensemble method with these hybrid features was developed to predict multi-type Gram-negative bacterial secreted proteins. Finally, our method achieves overall accuracies of 97.09% and 96.51% using an independent dataset test and jackknife test on a public test dataset, which are 3.49% and 2.32% higher, respectively, than results obtained by other methods. These results show the effectiveness and stability of the proposed ensemble method. It is anticipated that our method will provide useful information for further research on bacterial secreted proteins and secreted systems.

Panaxadiol inhibits synaptic dysfunction in Alzheimer's disease and targets the Fyn protein in APP/PS1 mice and APP-SH-SY5Y cells

AIM

Alzheimer's disease (AD), a neurodegenerative disease, is characterized by memory loss and synaptic damage. Up to now, there are limited drugs to cure or delay the state of this illness. Recently, the Fyn tyrosine kinase is implicated in AD pathology triggered by synaptic damage. Thus, Fyn inhibition may prevent or delay the AD progression. Therefore, in this paper, we investigated whether Panaxadiol could decrease synaptic damage in AD and the underlying mechanism.

MAIN METHODS

The ability of learning and memory of mice has detected by Morris Water Maze. The pathological changes detected by H&E staining and Nissl staining. The percentage of cell apoptosis and the calcium concentration were detected by Flow Cytometry in vitro. The amount of synaptic protein and related proteins in the Fyn/GluN2B/CaMKIIα signaling pathway were detected by Western Blot.

KEY FINDINGS

In the present article, Panaxadiol could significantly improve the ability of learning and memory of mice and reduce its synaptic dysfunction. Panaxadiol could down-regulate GluN2B's phosphorylation level by inhibition Fyn kinase activity, Subsequently, decrease Ca²⁺-mediated synaptic damage, reducing LDH leakage, inhibiting apoptosis in AD, resulting in facilitating the cells survival. For the underlying molecular mechanism, we used PP2 to block the Fyn/GluN2B/CaMKIIα signaling pathway. The results from WB showed that the expression of related proteins in the Fyn signaling pathway decreased with PP2 treated.

SIGNIFICANCE

Our results indicate that Panaxadiol could decrease synaptic damage, which will cause AD via inhibition of the Fyn/GluN2B/CaMKIIα signaling pathway. Thus, the Panaxadiol is a best promising candidate to test as a potential therapy for AD.

RETRACTED: Osthole decreases tau protein phosphorylation via PI3K/AKT/GSK-3β signaling pathway in Alzheimer's disease

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of Editor-in-Chief. The corresponding author notified the journal of image duplications within the published article and requested a corrigendum. Specifically, the ‘APP/PS1’ plot in Figure 1A had appeared in a previous publication [Panaxadiol inhibits synaptic dysfunction in Alzheimer's disease and targets the Fyn protein in APP/PS1 mice and APP-SH-SY5Y cells, Life Sciences (DOI: 10.1016/j.lfs.2019.03.070)], as the ‘TG’ plot in Figure 2A. In addition, several image duplications were identified within the panels of Figure 2. These issues, and others relating to unusual characteristics within the western blots, have been detailed here: https://pubpeer.com/publications/892AF7E4913255548C1446247FC65A#. As per journal policy when considering corrigendum requests, the journal requested the authors to provide explanations and source data relating to these affected figures. Upon receipt of additional source data, the editorial team noticed additional suspected image duplications. In relation to Figure 1A, the corresponding author stated that “…we mistakenly used the same Morris Water Maze data”, and a corrected figure was submitted. In relation to the image duplications within Figure 2, the corresponding author stated “…we mistakenly used the copy-and-paste tool instead of a color adjustment tool” during image post-processing. The corresponding author was unable to produce original unaltered and uncropped western blot source data. The editorial team have concerns about the provenance of the data and therefore the Editor-in-Chief decided to retract the article.

Biological characteristics of a new antibacterial peptide and its antibacterial mechanisms against Gram-negative bacteria

MDAP-2 is a new antibacterial peptide with a unique structure that was isolated from house- flies. However, its biological characteristics and antibacterial mechanisms against bacteria are still poorly understood. To study the biological characteristics, antibacterial activity, hemolytic activi- ty, cytotoxicity to mammalian cells, and the secondary structure of MDAP-2 were detected; the results showed that MDAP-2 displayed high antibacterial activity against all of the tested Gram-negative bacteria. MDAP-2 had lower hemolytic activity to rabbit red blood cells; only 3.4% hemolytic activity was observed at a concentration of 800μg/ml. MDAP-2 also had lower cytotoxicity to mammalian cells; IC50 values for HEK-293 cells, VERO cells, and IPEC-J2 cells were greater than 1000 μg/ml. The circular dichroism (CD) spectra showed that the peptide most- ly has α-helical properties and some β-fold structure in water and in membrane-like conditions. MDAP-2 is therefore a promising antibacterial agent against Gram-negative bacteria. To deter- mine the antibacterial mechanism(s) of action, fluorescent probes, flow cytometry, and transmis- sion electron microscopy (TEM) were used to study the effects of MDAP-2 on membrane perme- ability, polarization ability, and integrity of Gram-negative bacteria. The results indicated that the peptide caused membrane depolarization, increased membrane permeability, and destroyed membrane integrity. In conclusion, MDAP-2 is a broad-spectrum, lower hemolytic activity, and lower cytotoxicity antibacterial peptide, which is mainly effective on Gram-negative bacteria. It exerts its antimicrobial effects by causing bacterial cytoplasm membrane depolarization, increas- ing cell membrane permeability and disturbing the membrane integrity of Gram-negative bacte- ria. MDAP-2 may offer a new strategy to for defense against Gram-negative bacteria.

Elective nodal irradiation or involved-field irradiation in definitive chemoradiotherapy for esophageal squamous cell cancer: a retrospective analysis in clinical N0 patients

Objective

We compared failure patterns and survival after elective nodal irradiation (eni) or involved-field irradiation (ifi) in patients with thoracic esophageal squamous cell carcinoma (escc), clinical stage T2-4N0M0, to determine whether ifi is feasible for such patients.

Methods

Between 2005 and 2015, 126 patients with clinical stage T2-4N0M0 thoracic escc who received definitive concurrent chemoradiotherapy in Shandong Cancer Hospital and Institute and who had complete data, were analyzed retrospectively. Of those patients, 49 received ifi, and 77 received eni. In the ifi group, the radiation field included the primary tumour, with a 3-cm to 4-cm margin in the craniocaudal direction, and the elective irradiation was delivered to the adjacent regional lymphatics according to the location of the primary tumour. Patterns of failure were classified using the first site of failure, which included primary tumour failure, regional lymph node failure, and distant metastasis.

Results

Median progression-free survival was 20 months [95% confidence interval (ci): 7.87 months to 39.2 months] in the ifi group and 30 months (95% ci: 17.4 months to 44.6 months) in the eni group (p = 0.580). Median overall survival (os) was 36 months (95% ci: 21.9 months to 50.1 months) in the ifi group and 38 months (95% ci: 26.1 months to 49.9 months) in the eni group (p = 0.761). The estimated 1-year, 3-year, and 5-year os rates were, respectively, 87.8%, 49.4%, and 32.3% for the ifi patients and 92.2%, 52.0%, and 28.9% for the eni patients. Disease persistence and primary lesion recurrence after complete remission (cr) were the most frequent causes of treatment failure in the patients overall (83 of 124, 66.9%). Of the 66 patients achieving a clinical cr, 25 experienced recurrence of the primary lesion, 12 experienced distant relapse, 10 experienced regional nodal failure, and 2 experienced an isolated recurrence. No significant differences in the pattern of failure or in the incidences of grade 3 or greater treatment-related myelosuppression or esophagitis were found between the ifi and eni groups.

Conclusions

In patients with thoracic escc clinical stage T2-4N0M0 receiving definitive chemoradiotherapy, failure patterns and os were similar with either eni or ifi. Large prospective randomized studies are needed to further investigate and verify those results in this subgroup of patients.

A Phytophthora effector recruits a host cytoplasmic transacetylase into nuclear speckles to enhance plant susceptibility

Oomycete pathogens secrete host cell-entering effector proteins to manipulate host immunity during infection. We previously showed that PsAvh52, an early-induced RxLR effector secreted from the soybean root rot pathogen, Phytophthora sojae, could suppress plant immunity. Here, we found that PsAvh52 is required for full virulence on soybean and binds to a novel soybean transacetylase, GmTAP1, in vivo and in vitro. PsAvh52 could cause GmTAP1 to relocate into the nucleus where GmTAP1 could acetylate histones H2A and H3 during early infection, thereby promoting susceptibility to P. sojae. In the absence of PsAvh52, GmTAP1 remained confined to the cytoplasm and did not modify plant susceptibility. These results demonstrate that GmTAP1 is a susceptibility factor that is hijacked by PsAvh52 in order to promote epigenetic modifications that enhance the susceptibility of soybean to P. sojae infection.

Treatment of municipal sewage with low carbon-to-nitrogen ratio via simultaneous partial nitrification, anaerobic ammonia oxidation, and denitrification (SNAD) in a non-woven rotating biological contactor

In this study, a non-woven rotating biological contactor was evaluated for the treatment of municipal sewage via simultaneous partial nitrification, anaerobic ammonia oxidation (anammox), and denitrification (SNAD). Fluorescence in situ hybridization analysis showed that the dominant bacterial group in the aerobic outer layer of the biofilm was ammonia-oxidizing bacteria (65.13%), whereas anammox (47.17%) and denitrifying (38.91%) bacteria were present in the anaerobic inner layer. Response surface methodology was applied to develop mathematical models for the interaction between C/N and dissolved oxygen (DO) for chemical oxygen demand (COD) and total nitrogen (TN) removal. Results showed that the optimum region for SNAD was at C/N = 1.4-2.3 and DO = 0.2-0.8 mg/L. The most optimal operating condition was determined at C/N = 2.3 and DO = 0.2 mg/L, with actual removal rates of COD and TN were 83.12% and 79.13%, respectively, which are in close model consistency with model prediction (84% and 80%).

miR-155 Aggravates Liver Ischemia/reperfusion Injury by Suppressing SOCS1 in Mice

Liver ischemia/reperfusion injury (IRI) occurs during partial liver resection and liver transplantation. Activation of Toll-like receptors (TLRs) is a key event triggered by a range of proinflammatory cytokines during liver I/R. Although it has been reported that miR-155 takes part in both innate and adaptive immune responses, the potential role of miR-155 in liver IRI remains unknown. In this study, we found that expression of miR-155 was upregulated during liver I/R by many inflammatory cytokines, and forced expression of miR-155 aggravated hepatocyte injury following liver I/R both in vivo and in vitro. Mice transfected with Ago-miR-155-a chemically modified miR-155-showed enhanced liver severity compared to those transfected with negative control miRNA by inhibiting the expression of SOCS1, the target of miR-155. Thus by the inhibition of SOCS1, the overexpression of miR-155 promoted activation of NF-κB, and elevating the production of proinflammatory cytokines, such TNF-α and IL-6. In conclusion, miR-155 aggravates liver I/R injury in vivo and hepatocyte hypoxia/reoxygenation injury by suppressing the expression of SOCS1.

Comparative cytotoxicity and apoptotic pathways induced by nanosilver in human liver HepG2 and L02 cells

Silver nanoparticles are used in many commercial products in daily life. Exposure to nanosilver has hepatotoxic effects in animals. This study investigated the cytotoxicity associated with polyvinylpyrrolidone-coated nanosilver (23.44 ± 4.92 nm in diameter) exposure in the human hepatoma cell line (HepG2) and normal hepatic cell line (L02), and the molecular mechanisms induced by nanosilver in HepG2 cells. Nanosilver, in doses of 20-160 μg mL^-1 for 24 and 48 h, reduced cell viability in a dose- and time-dependent manner and induced cell membrane leakage and mitochondria injury in both cell lines; these effects were more pronounced in HepG2 cells than in L02 cells. Intracellular oxidative stress was documented by reactive oxygen species (ROS) being generated in HepG2 cells but not in L02 cells, an effect possibly due to differential uptake of nanosilver by cancer cells and normal cells. In HepG2 cells, apoptosis was documented by finding that ROS triggered a decrease in mitochondrial membrane potential, an increase in cytochrome c release, activation of caspase 3 and caspase 9, and a decrease in the ratio of Bcl-2/Bax. Furthermore, nanosilver activated the Fas death receptor pathway by downregulation of nuclear factor-κB and activation of caspase 8 and caspase 3. These results suggest that apoptosis induced by nanosilver in HepG2 cells is mediated via a mitochondria-dependent pathway and the Fas death receptor pathway. These findings provide toxicological and mechanistic information that can help in assessing the effects of nanosilver in biological systems, including the potential for anticancer activities.