Effect of silencing SSB1 gene on the expression of NBS1 in irradiated rat submandibular gland cells.

The salivary gland (SGS) is a kind of organ vulnerable to ionizing radiation. Radiotherapy is an important treatment for head and neck tumors, but in the process of radiotherapy, tumor cells will be injured by radiation to a certain extent. Infrared-induced DNA double-strand break (IR-DSBs) is one of the most serious DNA damage. DNA repair proteins such as Nymegan rupture syndrome protein 1 (NBS1) play a key role in the identification and repair of DNA damage. but the interaction between SSB1 and NBS1 has not been elucidated. In this study, we irradiated rat submandibular gland (SMG) cells, which were either infected with a rAdE5-SSB1-1p2-shRNA recombinant adenovirus to silence SSB or a control virus, to explore the effect of IR on the expression NBS1 in the absence of SSB. Our results showed that the SSB1 mRNA transcripts and protein expression of SSB1 and NBS1 initially increased and decreased later with increased doses. The relative expression reached the highest levels when the SMG cells were irradiated with 2Gy of IR. Silencing the SSB1 gene suppressed the expression of both SSB1 and NBS1 regardless of irradiation. The expression of NBS1 decreased when the SSB1 gene was silenced. We concluded that IR affected the expression of both SSB1 and NBS1 and there is a synergistic effect on IR-induced NBS1 suppression and DSBs repair in SMG cells. These observations shed light on further investigation and elucidation of IR-caused DNA repair mechanisms.

Inhaled RNA drugs to treat lung diseases: Disease-related cells and nano-bio interactions.

In recent years, RNA-based therapies have gained much attention as biomedicines due to their remarkable therapeutic effects with high specificity and potency. Lung diseases offer a variety of currently undruggable but attractive targets that could potentially be treated with RNA drugs. Inhaled RNA drugs for the treatment of lung diseases, including asthma, chronic obstructive pulmonary disease, cystic fibrosis, and acute respiratory distress syndrome, have attracted more and more attention. A variety of novel nanoformulations have been designed and attempted for the delivery of RNA drugs to the lung via inhalation. However, the delivery of RNA drugs via inhalation poses several challenges. It includes protection of the stability of RNA molecules, overcoming biological barriers such as mucus and cell membrane to the delivery of RNA molecules to the targeted cytoplasm, escaping endosomal entrapment, and circumventing unwanted immune response etc. To address these challenges, ongoing researches focus on developing innovative nanoparticles to enhance the stability of RNA molecules, improve cellular targeting, enhance cellular uptake and endosomal escape to achieve precise delivery of RNA drugs to the intended lung cells while avoiding unwanted nano-bio interactions and off-target effects. The present review first addresses the pathologic hallmarks of different lung diseases, disease-related cell types in the lung, and promising therapeutic targets in these lung cells. Subsequently we highlight the importance of the nano-bio interactions in the lung that need to be addressed to realize disease-related cell-specific delivery of inhaled RNA drugs. This is followed by a review on the physical and chemical characteristics of inhaled nanoformulations that influence the nano-bio interactions with a focus on surface functionalization. Finally, the challenges in the development of inhaled nanomedicines and some key aspects that need to be considered in the development of future inhaled RNA drugs are discussed.

A virtual-pinhole PET device for improving contrast recovery and enhancing lesion detectability of a one-meter-long PET scanner: a simulation study.

This paper presents a simulation study to demonstrate that the contrast recovery coefficients (CRC) and detectability of small lesions of a one-meter-long positron emission tomography (PET) scanner can be further enhanced by the integration of high resolution virtual-pinhole (VP) PET devices. The scanner under investigation is a Siemens Biograph Vision Quadra which has an axial field-of-view (FOV) of 106 cm. The VP-PET devices contain two high-resolution flat panel detectors, each composed of 2 × 8 detector modules each of which consists of 32 × 64 lutetium-oxyorthosilicate crystals (1.0 × 1.0 × 10.0 mm3each). Two configurations for the VP-PET device placement were evaluated: (1) place the two flat-panel detectors at the center of the scanner's axial FOV below the patient bed; (2) place one flat-panel detector at the center of the first and the last quarter of the scanner's axial FOV below the patient bed. Sensitivity profiles were measured by moving a point22Na source stepwise across the scanner's FOV axially at different locations. To assess the improvement in CRC and lesion detectability by the VP-PET devices, an elliptical torso phantom (31.6 × 22.8 × 106 cm3) was first imaged by the native scanner then subsequently by the two VP-PET geometry configurations. Spherical lesions (4 mm in diameter) having 5:1 lesion-to-background radioactivity concentration ratio were grouped and placed at nine regions in the phantom to analyze the dependence of the improvement in plane. Average CRCs and their standard deviations of the 7 tumors in each group were computed and the receiver operating characteristic (ROC) curves were drawn to evaluate the improvement in lesion detectability by the VP-PET device over the native long axial PET scanner. The fraction of coincidence events between the inserts and the scanner detectors was 13%-16% (out of the total number of coincidences) for VP-PET configuration 1 and 2, respectively. The VP-PET systems provide higher CRCs for lesions in all regions in the torso, with more significant enhancement at regions closer to the inserts, than the native scanner does. For any given false positive fraction, the VP-PET systems offer higher true positive fraction compared to the native scanner. This work provides a potential solution to further enhance the image resolution of a long axial FOV PET scanner to maximize its lesion detectability afforded by its super high effective sensitivity.

Airway epithelial cell-specific delivery of lipid nanoparticles loading siRNA for asthma treatment.

With specific and inherent mRNA cleaving activity, small interfering RNA (siRNA) has been deemed promising therapeutics to reduce the exacerbation rate of asthma by inhibiting the expression and release of proinflammatory cytokines from airway epithelial cells (AECs). To exert the therapeutic effects of siRNA drugs, nano-formulations with high efficiency and safety are required to deliver these nucleic acids to the target cells. Herein, we exploited novel inhaled lipid nanoparticles (LNPs) targeting intercellular adhesion molecule-1 (ICAM-1) receptors on the apical side of AECs. This delivery system is meant to enhance the specific delivery efficiency of siRNA in AECs to prevent the expression of proinflammatory cytokines in AECs and the concomitant symptoms in parallel. A cyclic peptide that resembles part of the capsid protein of rhinovirus and binds to ICAM-1 receptors was initially conjugated with cholesterol and subsequently assembled with ionizable cationic lipids to form the LNPs (Pep-LNPs) loaded with siRNA against thymic stromal lymphopoietin (TSLP siRNA). The obtained Pep-LNPs were subjected to thorough characterization and evaluations in vitro and in vivo. Pep-LNPs significantly enhanced cellular uptake and gene silencing efficiency in human epithelial cells expressing ICAM-1 in vitro, exhibited AEC-specific delivery and improved the gene silencing effect in ovalbumin-challenged asthmatic mice after pulmonary administration. More importantly, Pep-LNPs remarkably downregulated the expression of TSLP in AECs, effectively alleviated inflammatory cell infiltration, and reduced the secretion of other proinflammatory cytokines, including IL-4 and IL-13, as well as mucus production in asthmatic mice. This study demonstrates that Pep-LNPs are safe and efficient to deliver siRNA drugs to asthmatic AECs and could potentially alleviate allergic asthma by inhibiting the overexpression of proinflammatory cytokines in the airway.

MHCRoBERTa: pan-specific peptide-MHC class I binding prediction through transfer learning with label-agnostic protein sequences.

Predicting the binding of peptide and major histocompatibility complex (MHC) plays a vital role in immunotherapy for cancer. The success of Alphafold of applying natural language processing (NLP) algorithms in protein secondary struction prediction has inspired us to explore the possibility of NLP methods in predicting peptide-MHC class I binding. Based on the above motivations, we propose the MHCRoBERTa method, RoBERTa pre-training approach, for predicting the binding affinity between type I MHC and peptides. Analysis of the results on benchmark dataset demonstrates that MHCRoBERTa can outperform other state-of-art prediction methods with an increase of the Spearman rank correlation coefficient (SRCC) value. Notably, our model gave a significant improvement on IC50 value. Our method has achieved SRCC value and AUC value as 0.785 and 0.817, respectively. Our SRCC value is 14.3% higher than NetMHCpan3.0 (the second highest SRCC value on pan-specific) and is 3% higher than MHCflurry (the second highest SRCC value on all methods). The AUC value is also better than any other pan-specific methods. Moreover, we visualize the multi-head self-attention for the token representation across the layers and heads by this method. Through the analysis of the representation of each layer and head, we can show whether the model has learned the syntax and semantics necessary to perform the prediction task well. All these results demonstrate that our model can accurately predict the peptide-MHC class I binding affinity and that MHCRoBERTa is a powerful tool for screening potential neoantigens for cancer immunotherapy. MHCRoBERTa is available as an open source software at github (https://github.com/FuxuWang/MHCRoBERTa).

Breast carcinoma-amplified sequence 2 regulates adult neurogenesis via ß-catenin.

BACKGROUND: Breast carcinoma-amplified sequence 2 (BCAS2) regulates ß-catenin gene splicing. The conditional knockout of BCAS2 expression in the forebrain (BCAS2 cKO) of mice confers impaired learning and memory along with decreased ß-catenin expression. Because ß-catenin reportedly regulates adult neurogenesis, we wondered whether BCAS2 could regulate adult neurogenesis via ß-catenin. METHODS: BCAS2-regulating neurogenesis was investigated by characterizing BCAS2 cKO mice. Also, lentivirus-shBCAS2 was intracranially injected into the hippocampus of wild-type mice to knock down BCAS2 expression. We evaluated the rescue effects of BCAS2 cKO by intracranial injection of adeno-associated virus encoding BCAS2 (AAV-DJ8-BCAS2) and AAV-ß-catenin gene therapy. RESULTS: To show that BCAS2-regulating adult neurogenesis via ß-catenin, first, BCAS2 cKO mice showed low SRY-box 2-positive (Sox2+) neural stem cell proliferation and doublecortin-positive (DCX+) immature neurons. Second, stereotaxic intracranial injection of lentivirus-shBCAS2 knocked down BCAS2 in the hippocampus of wild-type mice, and we confirmed the BCAS2 regulation of adult neurogenesis via ß-catenin. Third, AAV-DJ8-BCAS2 gene therapy in BCAS2 cKO mice reversed the low proliferation of Sox2+ neural stem cells and the decreased number of DCX+ immature neurons with increased ß-catenin expression. Moreover, AAV-ß-catenin gene therapy restored neuron stem cell proliferation and immature neuron differentiation, which further supports BCAS2-regulating adult neurogenesis via ß-catenin. In addition, cells targeted by AAV-DJ8 injection into the hippocampus included Sox2 and DCX immature neurons, interneurons, and astrocytes. BCAS2 may regulate adult neurogenesis by targeting Sox2+ and DCX+ immature neurons for autocrine effects and interneurons or astrocytes for paracrine effects. CONCLUSIONS: BCAS2 can regulate adult neurogenesis in mice via ß-catenin.

Biochar reduces cadmium accumulation in rice grains in a tungsten mining area-field experiment: effects of biochar type and dosage, rice variety, and pollution level.

Cadmium (Cd)-contaminated rice (Oryza sativa) in Southern China is a great threat to food security, and the paddy soil remediation is urgently needed to reduce Cd accumulation in rice. Application of biochar could effectively immobilize soil Cd and reduce Cd uptake by rice. Fields that were applied with soil treatments including control and 15 and 30 t ha-1 each hickory nut shell-derived biochar (KC) or maize straw-derived biochar (MC), and grown with two rice varieties (hybrid rice and late japonica rice) were selected for this study. The long-term effect of biochars on decreasing Cd bioavailability in paddy soils was evaluated. The results showed when MC was applied at 15 t ha-1, DTPA-Cd (soil cadmium extracted by diethylenetriamine pentaacetic acid) was reduced by 20.0 and 34.5% in Field A (slightly Cd pollution) and B (moderately Cd pollution), respectively. In Field B, soil DTPA-Cd concentrations with application of 30 t ha-1 biochars were all lower than that of 15 t ha-1 biochar, but there were no significant differences between the two types of biochars. Cd concentration in rice grains and straws of hybrid rice are two times more than those of late japonica rice. Cd bio-concentration factor both of grains and straw was significantly increased by biochar application, which in Field A was higher than that in Field B. Our results suggest that biochars reduce Cd accumulation in rice grains by immobilizing soil Cd. KC has a higher potential in lowering Cd bioavailability than MC. Hybrid rice should be prohibited to cultivate in these areas.

[Sodium hydrosulfide attenuates myocardial injury through activating thioredoxin system in diabetic rats].

Objective To investigate the effect of exogenous hydrogen sulfide from sodium hydrosulfide (NaHS) on cardiac thioredoxin (Trx) system in diabetic rats. Methods Male Sprague-Dawley rats were randomly divided into a normal group, a diabetic group, and three NaHS (14, 28 and 56 µmol/kg) treatment groups, with 6 rats in each group. Type 1 diabetes was induced in the groups by a single intraperitoneal (i.p.) injection of streptozotocin. At the fifth week after modeling, the NaHS treatment groups were injected (i.p.) with NaHS at the doses of 14, 28 and 56 µmol/kg once a day, respectively. After the treatment for 4 weeks, the fasting blood glucose (FBG) level and ventricular hemodynamic parameters were measured. The changes of myocardial pathomorphology were observed by HE staining. The ultrastructural changes of cardiomyocytes were observed by transmission electron microscopy. The levels of serum lactate dehydrogenase (LDH), creatine kinase (CK), and creatine kinase MB isozyme (CK-MB) were examined using the kits. Serum interleukin (IL)-1ß, IL-6, and tumor necrosis factor α (TNF-α) were assayed by ELISA. The levels of total antioxidant capacity (T-AOC), lipid peroxide (LPO), and malondialdehyde (MDA) in myocardium were analyzed using the kits. The mRNA expression of heme oxygenase 1 (HO-1) was detected using reverse transcription PCR (RT-PCR). The expression levels of Trx, Trx-interacting protein (TXNIP), and nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2) in myocardium were measured using Western blotting. Results Compared with the normal group, the left ventricular systolic and diastolic functions were weakened in the diabetic group, and the myocardial morphological structure and ultrastructure were damaged obviously. The FBG, LDH, CK, CK-MB, IL-1ß, IL-6, TNF-α, LPO and MDA levels increased, while the T-AOC level decreased. The myocardial Trx protein expression was reduced, while the expressions of HO-1 mRNA, TXNIP and NOX2 proteins were elevated in the diabetic group. Compared with the diabetic group, the left ventricular systolic and diastolic functions, myocardial morphological structure and ultrastructure were improved in the three NaHS treatment groups. The LDH, CK, CK-MB, IL-1ß, IL-6, TNF-α, LPO and MDA levels decreased, while T-AOC increased. The myocardial HO-1 mRNA and Trx protein expressions were enhanced, while TXNIP and NOX2 protein expressions were suppressed. Conclusion NaHS treatment attenuates diabetic myocardial injury, and the mechanisms may be associated with the activation of the Trx system, the enhancement of antioxidant capability and the inhibition of inflammatory factor release.