Trap & kill: a neutrophil-extracellular-trap mimic nanoparticle for anti-bacterial therapy

Fenton chemistry-mediated antimicrobials have demonstrated great promise in antibacterial therapy. However, the short life span and diffusion distance of hydroxyl radicals dampen the therapeutic efficiency of these antimicrobials. Herein, inspired by the neutrophil extracellular trap (NET), in which bacteria are trapped and agglutinated via electronic interactions and killed by reactive oxygen species, we fabricated a NET-mimic nanoparticle to suppress bacterial infection in a "trap & kill" manner. Specifically, this NET-mimic nanoparticle was synthesized via polymerization of ferrocene monomers followed by quaternization with a mannose derivative. Similar to the NET, the NET-mimic nanoparticles trap bacteria through electronic and sugar-lectin interactions between their mannose moieties and the lectins of bacteria, forming bacterial agglutinations. Therefore, they confine the spread of the bacteria and restrict the bacterial cells to the destruction range of hydroxyl radicals. Meanwhile, the ferrocene component of the nanoparticle catalyzes the production of highly toxic hydroxyl radicals at the H2O2 rich infection foci and effectively eradicates the agglutinated bacteria. In a mouse model of an antimicrobial-resistant bacteria-infected wound, the NET-mimic nanoparticles displayed potent antibacterial activity and accelerated wound healing.

Post-COVID-19 Pandemic Rebound of Macrolide-Resistant Mycoplasma pneumoniae Infection: A Descriptive Study

The rebound characteristics of respiratory infections after lifting pandemic control measures were uncertain. From January to November 2023, patients presenting at a teaching hospital were tested for common respiratory viruses and Mycoplasma pneumoniae using a combination of antigen, nucleic acid amplification, and targeted next-generation sequencing (tNGS) tests. The number and rate of positive tests per month, clinical and microbiological characteristics were analyzed. A rapid rebound of SARS-CoV-2 was followed by a slower rebound of M. pneumoniae, with an interval of 5 months between their peaks. The hospitalization rate was higher, with infections caused by respiratory viruses compared to M. pneumoniae. Though the pediatric hospitalization rate of respiratory viruses (66.1%) was higher than that of M. pneumoniae (34.0%), the 4094 cases of M. pneumoniae within 6 months posed a huge burden on healthcare services. Multivariate analysis revealed that M. pneumoniae-infected adults had more fatigue, comorbidities, and higher serum C-reactive protein, whereas children had a higher incidence of other respiratory pathogens detected by tNGS or pathogen-specific PCR, fever, and were more likely to be female. A total of 85% of M. pneumoniae-positive specimens had mutations detected at the 23rRNA gene, with 99.7% showing A2063G mutation. Days to defervescence were longer in those not treated by effective antibiotics and those requiring a change in antibiotic treatment. A delayed but significant rebound of M. pneumoniae was observed after the complete relaxation of pandemic control measures. No unusual, unexplained, or unresponsive cases of respiratory infections which warrant further investigation were identified.

[Pathological evaluation of endoscopic submucosal dissection for early gastric cancer and precancerous lesion in 411 cases]

OBJECTIVE

To evaluate the pathological characteristics of endoscopic submucosal dissection (ESD) specimens for early gastric cancer and precancerous lesions, accumulating experience for clinical management and pathological analysis.

METHODS

A total of 411 cases of early gastric cancer or precancerous lesions underwent ESD. According to the Japanese guidelines for ESD treatment of early gastric cancer and classification of gastric carcinoma, the clinicopathological data, pathologic evaluation, concordance rate of pathological diagnosis between preoperative endoscopic forceps biopsies and their ESD specimens (in 400 cases), as well as the risk factors of non-curative resection of early gastric cancer, were analyzed retrospectively.

RESULTS

23.4% (96/411) of the 411 cases were adenoma/low-grade dysplasia and 76.6% (315/411) were early gastric cancer. The latter included 28.0% (115/411) non-invasive carcinoma/high-grade dysplasia and 48.7% (200/411) invasive carcinoma. The concordance rate of pathological diagnosis between endoscopic forceps biopsies and ESD specimens was 66.0% (264/400), correlating with pathological diagnosis and lesion location (P < 0.01). The rate of upgraded diagnosis and downgraded diagnosis after ESD was 29.8% (119/400) and 4.2% (17/400), respectively. Among the 315 cases of early gastric cancer, there were 277 cases (87.9%) of differentiated type and 38 cases (12.1%) of undifferentiated type. In the study, 262 cases (83.2%) met with absolute indication, while 53 cases (16.8%) met relative indication. En bloc and curative resection rates were 98.1% and 82.9%, respectively. Risk factors for non-curative resection included a long diameter >20 mm (OR=3.631, 95%CI: 1.170-11.270, P=0.026), tumor infiltration into submucosa (OR=69.761, 95%CI: 21.033-231.376, P < 0.001)and undifferentiated tumor histology (OR=16.950, 95%CI: 4.585-62.664, P < 0.001).

CONCLUSION

Several subjective and objective factors, such as the limitations of biopsy samples, the characteristics and distribution of the lesions, different pathological understanding, and the endoscopic sampling and observation, can lead to the differences between the preoperative and postoperative pathological diagnosis of ESD. In particular, the pathological upgrade of postoperative diagnosis was more significant and should receive more attention by endoscopists and pathologists. The curative resection rate of early gastric cancer in ESD was high. Non-curative resection was related to the long diameter, the depth of tumor invasion and histological classification. ESD can also be performed in undifferentiated early gastric cancer if meeting the indication criteria. The comprehensive and standardized pathological analysis of ESD specimens is clinically important to evaluate the curative effect of ESD operation and patient outcomes.

MicroRNA-128 suppresses tau phosphorylation and reduces amyloid-beta accumulation by inhibiting the expression of GSK3β, APPBP2, and mTOR in Alzheimer's disease

INTRODUCTION AND AIMS

Alzheimer's disease (AD) is characterized by the abnormal accumulation of hyperphosphorylated tau proteins and amyloid-beta (Aβ) peptides. Recent studies have shown that many microRNAs (miRNAs) are dysregulated in AD, and modulation of these miRNAs can influence the development of tau and Aβ pathology. The brain-specific miRNA miR-128, encoded by MIR128-1 and MIR128-2, is important for brain development and dysregulated in AD. In this study, the role of miR-128 in tau and Aβ pathology as well as the regulatory mechanism underlying its dysregulation were investigated.

METHODS

The effect of miR-128 on tau phosphorylation and Aβ accumulation was examined in AD cellular models through miR-128 overexpression and inhibition. The therapeutic potential of miR-128 in AD mouse model was assessed by comparing phenotypes of 5XFAD mice administered with miR-128-expressing AAVs with 5XFAD mice administered with control AAVs. Phenotypes examined included behavior, plaque load, and protein expression. The regulatory factor of miR-128 transcription was identified through luciferase reporter assay and validated by siRNA knockdown and ChIP analysis.

RESULTS

Both gain-of-function and loss-of-function studies in AD cellular models reveal that miR-128 represses tau phosphorylation and Aβ secretion. Subsequent investigations show that miR-128 directly inhibits the expression of tau phosphorylation kinase GSK3β and Aβ modulators APPBP2 and mTOR. Upregulation of miR-128 in the hippocampus of 5XFAD mice ameliorates learning and memory impairments, decreases plaque deposition, and enhances autophagic flux. We further demonstrated that C/EBPα transactivates MIR128-1 transcription, while both C/EBPα and miR-128 expression are inhibited by Aβ.

CONCLUSION

Our findings suggest that miR-128 suppresses AD pathogenesis, and could be a promising therapeutic target for AD. We also find a possible mechanism underlying the dysregulation of miR-128 in AD, in which Aβ reduces miR-128 expression by inhibiting C/EBPα.

Finite-Time Thermodynamic Modeling and Optimization of Short-Chain Hydrocarbon Polymerization-Catalyzed Synthetic Fuel Process

The short-chain hydrocarbon polymerization-catalyzed synthetic fuel technology has great development potential in the fields of energy storage and renewable energy. Modeling and optimization of a short-chain hydrocarbon polymerization-catalyzed synthetic fuel process involving mixers, compressors, heat exchangers, reactors, and separators are performed through finite-time thermodynamics. Under the given conditions of the heat source temperature of the heat exchanger and the reactor, the optimal performance of the process is solved by taking the mole fraction of components, pressure, and molar flow as the optimization variables, and taking the minimum entropy generation rate (MEGR) of the process as the optimization objective. The results show that the entropy generation rate of the optimized reaction process is reduced by 48.81% compared to the reference process; among them, the component mole fraction is the most obvious optimization variable. The research results have certain theoretical guiding significance for the selection of the operation parameters of the short-chain hydrocarbon polymerization-catalyzed synthetic fuel process.

hsa_circ_0003176 Suppresses the Progression of Non-Small-Cell Lung Cancer via Regulating miR-182-5p/RBM5 Axis

Background

Non-small-cell lung cancer (NSCLC) is one of the major diseases that threaten human health, and there is still no fundamental treatment method. Emerging evidences suggested that circRNAs might be an effective target to treatment NSCLC. However, the roles and detailed mechanisms of hsa_circ_0003176 in NSCLC still not clear.

Methods

hsa_circ_0003176 was identified from GSE101684 and GSE112214 datasets of Gene Expression Omnibus (GEO) database. The expression of hsa_circ_0003176 was detected by RT-qPCR in NSCLC tissues, paired adjacent nontumor tissues, and cell lines. RNA fluorescence in situ hybridization and nuclear and cytoplasmic RNA fractionation analysis was used to detect the subcellular localization of hsa_circ_0003176 in H1299 and A549 cells. Dual-luciferase reporter and RNA pull-down assay were used to confirm the regulatory of miR-182-5p to hsa_circ_0003176 and RBM5. The roles of hsa_circ_0003176 in NSCLC progression was evaluated both in vitro by CCK-8 assay, colony formation assay, wound-healing assay, and matrigel transwell assay and in vivo by the subcutaneous xenograft nude mouse experiment and lung metastasis nude mouse experiment. In addition, RNA pull down and luciferase reporter assays were carried out to investigate the interaction between hsa_circ_0003176 or RBM5 and miR-182-5p.

Results

Our results indicated that hsa_circ_0003176 showed typical characteristic of circRNAs, which was downregulated in both NSCLC tissues and cell lines. Functionally, overexpression of hsa_circ_0003176 suppressed the proliferation, migration, and invasion of NSCLC cells in vitro and inhibited NSCLC growth and metastasis in vivo. Furthermore, we found that hsa_circ_0003176 acts as sponge of miR-182-5p to regulate RBM5 expression. Further, in vitro rescue experiments demonstrated that hsa_circ_0003176 suppressed the proliferation, migration, and invasion of NSCLC cells by regulating miR-182-5p/RBM5 axis.

Conclusion

We demonstrated that hsa_circ_0003176 suppressed the NSCLC progression via regulating miR-182-5p/RBM5 axis. These data indicated that hsa_circ_0003176 might be a novel molecular target for NSCLC treatment.

Combining single-cell RNA sequencing of peripheral blood mononuclear cells and exosomal transcriptome to reveal the cellular and genetic profiles in COPD

Background

It has been a long-held consensus that immune reactions primarily mediate the pathology of chronic obstructive pulmonary disease (COPD), and that exosomes may participate in immune regulation in COPD. However, the relationship between exosomes and peripheral immune status in patients with COPD remains unclear.

Methods

In this study, we sequenced plasma exosomes and performed single-cell RNA sequencing on peripheral blood mononuclear cells (PBMCs) from patients with COPD and healthy controls. Finally, we constructed competing endogenous RNA (ceRNA) and protein–protein interaction (PPI) networks to delineate the interactions between PBMCs and exosomes within COPD.

Results

We identified 135 mRNAs, 132 lncRNAs, and 359 circRNAs from exosomes that were differentially expressed in six patients with COPD compared with four healthy controls. Functional enrichment analyses revealed that many of these differentially expressed RNAs were involved in immune responses including defending viral infection and cytokine–cytokine receptor interaction. We also identified 18 distinct cell clusters of PBMCs in one patient and one control by using an unsupervised cluster analysis called uniform manifold approximation and projection (UMAP). According to resultant cell identification, it was likely that the proportions of monocytes, dendritic cells, and natural killer cells increased in the COPD patient we tested, meanwhile the proportions of B cells, CD4 + T cells, and naïve CD8 + T cells declined. Notably, CD8 + T effector memory CD45RA + (Temra) cell and CD8 + effector memory T (Tem) cell levels were elevated in patient with COPD, which were marked by their lower capacity to differentiate due to their terminal differentiation state and lower reactive capacity to viral pathogens.

Conclusions

We generated exosomal RNA profiling and single-cell transcriptomic profiling of PBMCs in COPD, described possible connection between impaired immune function and COPD development, and finally determined the possible role of exosomes in mediating local and systemic immune reactions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02182-8.

P-583 PCOS patients got better IVF/ICSI outcomes with “higher” progesterone level on hCG day: a retrospective study of Ten years data

Study question

We aimed to investigate whether serum Progesterone (P) on the day of hCG trigger can be used as a biomarker to predict the IVF/ICSI outcomes in PCOS patients.

Summary answer

PCOS patients got better IVF/ICSI outcomes with “higher” progesterone level (2.7-5.9mmol/L).

What is known already

There were several studies suggesting serum Progesterone (P) on the day of hCG trigger can be used as a biomarker to predict IVF outcomes, and to decide fresh cycle embryo transfer or frozen all. But there was few study focus on PCOS patients.

Study design, size, duration

This is a single-center retrospective cohort study in PCOS women undergoing the first transfer of an IVF cycle between January 1st 2010 and December 31th 2019. There were 141,539 oocyte retrieval cycles during the study period, and 97,189 cycles were their first IVF cycle. PCOS was diagnosed according to the Rotterdam criteria. Among them, 3,146 cycles full filled the inclusion and exclusion criteria, and all with two embryos transferred on Day 3.

Participants/materials, setting, methods

We compared the live birth rate of fresh embryo transfer, stratified for serum P level. We looked for interaction between serum P level and live birth rate of fresh cycles. The serum P level within normal range (&lt; 6nmol/L) on the day of hCG trigger day was divided into 4 quartiles. The four quartiles were defined as ≤ 1.35 nmol/L (Q1), &gt;1.35-1.93 nmol/L (Q2), &gt;1.93-2.7 nmol/L (Q3), &gt;2.7 nmol/L (Q4).

Main results and the role of chance

The baseline characteristics with no different between groups, except BMI. The patients in Q4 group with lowest BMI, significantly higher number of oocytes retrieved and live birth rate (P &lt; 0.05) . The Logistic regression analysis of the relative factors on live birth rate including BMI, basal LH and number of oocytes retrieved [P = 0.003, 0.030, 0.037 respectively, 95%CI (1.022, 1.111), (1.004, 1.076), (1.002, 1.082)].

Limitations, reasons for caution

Due to the retrospective nature of this study, a well-designed and matched large sample prospective study is needed. The definition of elevated P level and the method of hormonal assessments were different between studies, this limiting the comprehensive analysis of researches and the further verification of existing results.

Wider implications of the findings

PCOS patients who with normal range P level on hCG day, got better IVF/ICSI outcomes with “higher” progesterone level (2.7-5.9mmol/L). Weight control is important for PCOS patients accepting IVF treatment.

Trial registration number

NOT APPLICABLE

Association between comorbid sleep apnoea-hypopnoea syndrome and prognosis of intensive care patients: a retrospective cohort study

OBJECTIVE

In this study, we investigated the association between comorbid sleep apnoea-hypopnoea syndrome (SAHS) and the prognosis of patients in an intensive care unit (ICU) to determine whether this relationship varies between different disease subgroups.

METHODS

We conducted a retrospective cohort study using publicly available information from the critical care database Medical Information Mart for Intensive Care III. Adults (≥18 years of age) who attended the ICU for the first time were enrolled. Demographic information and clinical data were obtained from each patient. The primary outcome was 30-day mortality after ICU admission, and the secondary outcomes were in-hospital and ICU mortality. Multivariate logistic regression and Cox regression analyses were used to examine the associations between SAHS comorbidities and the research outcomes. Propensity score matching was used to adjust for potential confounding variables.

RESULTS

Of the 32 989 patients enrolled, 1918 (5.81%) were diagnosed with SAHS as a comorbid condition. Patients with SAHS had a significantly lower 30-day mortality rate compared with those without SAHS (5.27% vs 13.65%, respectively; p<0.001). The frequency of chronic obstructive pulmonary disease, cerebral disease, cardiovascular disease, hypertension, diabetes mellitus and renal failure was significantly different between the two groups. Patients with SAHS demonstrated significantly longer survival compared with patients without SAHS. Multivariate Cox proportional hazards regression identified a significant relationship between SAHS and mortality within 30 days (adjusted HR=0.610, 95% CI 0.499 to 0.747, p<0.0001).

CONCLUSION

SAHS as a comorbid condition decreases the risk of 30-day mortality, in-hospital mortality and ICU mortality among ICU patients.

Significance of nucleic acid positive anal swab in COVID-19 patients

Aim

We compared the clinical characteristics of patients with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) positive and negative anal swabs during coronavirus disease 2019 (COVID-19) recovery and investigated the clinical significance and influence factors of anal swab detection.

Methods

This study retrospectively analyzed 23 moderate COVID-19 patients in the recovery phase. They were divided into anal swab positive group (n = 13) (negative for pharyngeal swabs but positive for anal swabs) and anal swab negative group (n = 10) (negative for pharyngeal and anal swabs). The epidemiology, clinical symptoms, time of pharyngeal swabs turning negative, and laboratory results were compared.

Results

The time of pharyngeal swabs turning negative in the anal swab positive group was 6 (5–8.5) days, significantly longer than that in the anal swab negative group (1 (1–4.25) days), P = 0.0002). The platelet count of the anal swab positive group was significantly lower than that of the anal swab negative group (198 (135–235) × 109/L vs 240.5 (227–264.75) × 109/L, P = 0.0248). No significant difference was observed between the two groups in other variables.

Conclusions

The time of pharyngeal swab turning negative in anal swab positive patients is longer than that in anal swab negative patients. The platelet count can be used as an indicator for viral infection evaluation. For patients with a longer time of pharyngeal swabs turning negative, the combined testing of the anal swab and platelet counts may help to avoid pharyngeal swab false negatives, premature discharge, and the possibility of fecal-oral transmission.

[Analysis of the self-conscious health status and influencing factors of greenhouse agricultural workers in Beijing suburb]

Objective: To explore the self-conscious health status and related influencing factors of greenhouse agricultural workers in Beijing suburb, so as to provide scientific basis for developing strategies to improve and promote the occupational health conditions of those workers. Methods: According to the production characteristics and scale of the main agricultural districts or counties in the suburb of Beijing, 182 agricultural production personnel were randomly selected to investigate the general situation, occupational situation and self-conscious health status during June 2018 to December 2019. The relevant factors which may affect the self-conscious health conditions were also analyzed by statistical methods. Results: The detection or reported rate of self-conscious health problems was 51.6% (94/182) , among which 29.1% (53/182) workers reported musculoskeletal disorder diseases and 21.4% (39/182) workers reported nervous system diseases. And the self-conscious health status of greenhouse agricultural workers were statistically different in household registration, gender, marital status, working years, mixing or spraying pesticides, smoking or eating in the greenhouse (P<0.05) . Moreover, gender, mixing or spraying pesticide, eating and smoking behavior in the workplace all had an impact on the risk of self-conscious health status of greenhouse agricultural workers (P< 0.05) . Specifically, male is the protective factor to reduce the occurrence of self-conscious symptoms of greenhouse agricultural workers (OR=0.447, 95%CI: 0.234~0.852) , while mixing or spraying pesticides and smoking or eating behaviors in the workplace are the risk factors (OR=1.055, 2.524; 95%CI: 0.503~2.210, 1.107~5.755) . Conclusion: Reducing pesticide use from the source thus minimize related exposure opportunities, strengthening occupational health education thus foster good hygienic habits and improve individual protection consciousness are of great significance for the health protection of greenhouse agricultural workers in Beijing suburb.

Engineering Living Bacteria for Cancer Therapy

Bacteria possess many unique properties in treating cancer that are unachievable with standard methods, including specific tumor targeting, deep tissue penetration, and programmable therapeutic efficacy. Bacteria species such as Salmonella, Escherichia, Clostridium, and Listeria have been demonstrated to restrict tumor growth with improved prognosis in mice models. Moreover, some bacterial strains were advanced to clinical trials. This Spotlight on Applications summarizes general strategies for engineering living bacteria to fight cancer and provides examples to illustrate different approaches to engineer bacteria for safety and therapeutic index improvement.

Endothelin-1 induces chondrocyte senescence and cartilage damage via endothelin receptor type B in a post-traumatic osteoarthritis mouse model

OBJECTIVES

This study aimed to investigate the role of endothelin-1 (ET-1), originally known as the potent vasoconstrictor, and its receptors in chondrocyte senescence and osteoarthritis (OA) development.

METHOD

Temporal changes of ET-1 and its receptors with OA development were characterized in a posttraumatic OA (PTOA) mouse model at time zero, 1-month and 4-month after surgical induction via destabilization of medial meniscus (DMM). A transgenic ET-1 overexpression (TET-1) mouse model was deployed to assess the impact of upregulated ET-1 on chondrocyte senescence and cartilage degradation. Effects of endothelin receptor blockade on chondrocyte senescence and OA development were further examined both in vitro and in vivo.

RESULTS

Local expression of ET-1 in subchondral bone and synovium upregulated after DMM with an increase of plasma ET-1 level from 3.18 ± 0.21 pg/ml at time zero to 6.47 ± 0.34 pg/ml at 4-month post-surgery. Meanwhile, endothelin type B receptor (ET_BR) (53.31 ± 2.42% to 83.8 ± 2.65%) and p16^INK4a (10.91 ± 1.07% to 28.2 ± 1.0%) positve chondrocytes accumulated in articular cartilage since 1-month prior to cartilage loss at 4-month post-surgery. Overexpressed ET-1 promoted p16^INK4a-positive senescent chondrocytes accumulation and cartilage degradation in TET-1 mice. Selective blockade of ET_BR, but not ET_AR, lowered the expression of p16^INK4a in ET-1 or H₂O₂-induced chondrocyte senescence model, and mitigated the severity of murine PTOA. Intriguingly, reactive oxygen species (ROS) scavenger, Vitamin C, could rescue ET-1-induced chondrocyte senescence in vitro associated with restoration of mitochondrial dynamics.

CONCLUSION

ET-1 could induce chondrocytes senescence and cartilage damages via ET_BR in PTOA.

Monitoring bronchoalveolar lavage with electrical impedance tomography: first experience in a patient with COVID-19

OBJECTIVE

Patients with the novel coronavirus disease (COVID-19) often have airway secretions that severely compromise ventilation. This study investigates electrical impedance tomography (EIT) monitoring of a therapeutic bronchoalveolar lavage (BAL) in a patient with COVID-19.

APPROACH

A patient with COVID-19 developed acute respiratory distress syndrome requiring mechanical ventilation. He received regional BAL to remove mucus in the small airways (20 ml × 5). Regional ventilation changes before BAL, 30 min after and in the following days, were monitored with EIT.

MAIN RESULTS

Regional ventilation worsened shortly after BAL and improved in the following days. The improvement of the oxygenation did not exactly match the ventilation improvement, which indicated a possible ventilation/perfusion mismatch.

SIGNIFICANCE

Therapeutic BAL might improve regional ventilation for COVID-19 and EIT could be a useful tool at the bedside to monitor the ventilation treatment of COVID-19.

Iron chelated melanin-like nanoparticles for tumor-associated macrophage repolarization and cancer therapy

Tumor-associated macrophages (TAMs) are abundant in many cancers, and predominately display an immunosuppressive M2-like function that fosters tumor progression and promotes malignant metastasis. Current TAMs repolarization strategies mainly focused on harnessing the direct cancer cell killing property of M1-like macrophages repolarized from TAMs. However, the latent role of M1-like macrophages as professional antigen-presenting cells (APCs) also needs to be explored. Here, iron chelated melanin-like nanoparticles (Fe@PDA-PEG) were developed for M2-to-M1 TAMs repolarization and photothermal therapy (PTT) induced tumor-associated antigens (TAAs) releasing, which would exploit the potential of M1-like macrophages acquired as professional APCs for TAAs presentation. The results showed that M1 macrophages repolarized from TAMs by Fe@PDA-PEG could capture, process and present TAAs released by PTT through the major histocompatibility complex class II (MHC II) pathway, recruiting T-helper cells and effector T cells in tumor site, which leads to the controlled tumor growth and limited malignant metastasis.

[Clinical short-term and long-term efficacy of endoscopic submucosal dissection in the treatment of early low rectal cancer and precancerous lesions]

Objective: To evaluate the short-term and long-term efficacy of endoscopic submucosal dissection (ESD) in the treatment of early low rectal cancer and precancerous lesions. Methods: Inclusion criteria: (1) Distance from the lower margin of tumor to the anal was ≤ 5 cm. (2) Early low rectal cancers were any size rectal epithelial tumors with infiltration depth limited to the mucosa and submucosa, which were diagnosed by postoperative pathology as high-grade intraepithelial neoplasia or adenocarcinoma of the rectum with infiltration depth of intramucosal or submucosal cancer (M or SM stage). (3) Precancerous lesions included adenoma and low-grade intraepithelial neoplasia of the rectum. (4) Patients received ESD treatment. Patients with tumor invasion depth over submucosa by pathology were excluded. From January 2008 to January 2018, 63 patients meeting the above criteria in Peking University First Hospital were enrolled in this descriptive cohort study. The disease characteristics, clinical manifestations, pathological types, treatment time, hospitalization time, en bloc resection rate (resection of the whole lesion), complete resection rate (both the horizontal and vertical incision margins were negative), postoperative complications and follow-up results were analyzed. Cummulative survival rate was calculated by Kaplan-Meier. Results: The diameter of the lesion was (29.0±23.4) mm and the distance from the lesion to the anus was (2.7±1.8) cm. The median operation time was 45.0 (range, 10.0 to 360.0) minutes, the median hospitalization time was 3.0 (range, 2.0 to 12.0) days, en bloc resection rate was 100%, complete resection rate was 96.8% (61/63), and 1 case (1.6%) had postoperative bleeding. The follow-up rate was 87.3% (55/63) and the median follow-up time was 57.9 (range, 15.6 to 121.1) months. No local recurrence was found during the follow-up period and the 5-year survival rate was 100%. Conclusion: Short- and long-term efficacy of ESD are quite good in the treatment of patients with early low rectal cancer and precancerous lesions.

A Versatile Carbon Monoxide Nanogenerator for Enhanced Tumor Therapy and Anti-Inflammation

Carbon monoxide (CO) is regarded as a potential therapeutic agent with multiple beneficial functions for biomedical applications. In this study, a versatile CO nanogenerator (designated as PPOSD) was fabricated and developed for tumor therapy and anti-inflammation. Partially oxidized tin disulfide (SnS₂) nanosheets (POS NSs) were decorated with a tumor-targeting polymer (polyethylene glycol-cyclo(Asp-d-Phe-Lys-Arg-Gly), PEG-cRGD), followed by the loading of chemotherapeutic drug doxorubicin (DOX) to prepare polymer@POS@DOX, or PPOSD. After injected intravenously, PPOSD could selectively accumulate in tumor tissue via the cRGD-mediated tumor recognition. Upon 561 nm laser irradiation, the POS moiety in PPOSD can photoreduce CO₂ to CO, which significantly sensitized the chemotherapeutic effect of DOX. The POS in PPOSD can also act as a photothermal agent for effective photothermal therapy (PTT) of the tumor upon 808 nm laser irradiation. Furthermore, the generated CO can simultaneously decrease the inflammatory reaction caused by PTT. Blood analysis and hematoxylin-eosin staining of major organs showed that no obvious systemic toxicity was induced after the treatment, suggesting good biosafety of PPOSD. This versatile CO nanogenerator will find great potential for both enhanced tumor inhibition and anti-inflammation.

Protease sensitivity and redistribution of CD71 and glycophorin A on K562 cells

Transmembrane proteins are delivered to plasma membrane from the endoplasmic reticulum and Golgi complex by vesicular transport along with the cytoskeletal network. Disruption of this process likely affects transmembrane protein expression. K562 cells were digested with Streptomyces griseus protease for different periods of time, and then re-cultured with different cytoskeletal and glycosylation inhibitors. Cell viability and surface expression of transferrin receptor (CD71) and glycophorin A (GPA) were analyzed before and after re-culture by flow cytometry. We found that digestion with protease almost completely removed extracellular CD71 and GPA but their expression recovered to the initial levels after re-culture for 8 h and 24 h, respectively. The microtubule depolymerizer colchicine promoted cell surface recovery of CD71 but inhibited that of GPA; the microtubule stabilizer paclitaxel inhibited cell surface recovery of CD71 but promoted that of GPA; the microfilament depolymerizer cytochalasin D had no effect on cell surface recovery of CD71 and GPA; the microfilament stabilizer phalloidin inhibited cell surface recovery of GPA. The glycosylation inhibitor tunicamycin inhibited the recovery of both CD71 and GPA, and BADGP inhibited the recovery of GPA. These studies show differential sensitivities of surface proteins on K562 cells to proteases, and suggest molecular mechanisms of transmembrane protein transport and cycling.

Stimuli-Responsive "Cluster Bomb" for Programmed Tumor Therapy

In this paper, mesoporous silica nanoparticle (MSN) loaded with doxorubicin (DOX) and capped with tumor-homing/-penetrating peptide tLyP-1-modified tungsten disulfide quantum dots (WS₂-HP) was designed and applied as a stimuli-responsive "Cluster Bomb" for high-performance tumor suppression. The peptide tLyP-1 on the surface can both facilitate the homing of DOX@MSN-WS₂-HP to 4T1 tumor and greatly enhance the penetration of WS₂-HP in tumor. The benzoic-imine bonds as the linkers between "bomblets" and "dispenser" are stable under normal physical conditions and quite labile at pH 6.8. After arriving at the mild acidic tumor microenvironment, the nanoplatform can rapidly break into two parts: (1) electropositive DOX@MSN-NH₂ for efficient chemotherapy on surface tumor cells and (2) small-sized WS₂-HP with improved tumor penetrating ability for near-infrared (NIR)-light-triggered photothermal therapy (PTT) among deep-seated tumor cells. Having killed the tumor cells in different depths, DOX@MSN-WS₂-HP exhibited significant antitumor effect, which will find great potential in clinical trials.

Answers to if the Lead Aprons are Really Helpful in Nuclear Medicine from the Perspective of Spectroscopy

Wearing lead X-ray-protective aprons is a routine in nuclear medicine department in parts of China. However, the staff are often perplexed by questions such as if it is imperative to wear aprons when injecting radioactive drugs, how much radiation dosage can be shielded and if the apron will produce secondary radiation instead? To answer these questions, a semiconductor detector was employed to record different gamma and X-ray spectra with and without the lead apron or lead sheet. Then, we could estimate the signal shielding ratio to different photons for the lead apron and compare with the hospitals measured data. In general, the two results coincided well. The spectral results showed that the detrimental secondary X-rays irradiation rises when the energy of gamma rays exceeds the K absorption edge of lead (88 keV). Moreover, the aprons are not so effective for gamma rays of 364 keV emitted from 131I and 511 keV emitted from the positron radioactive nuclides. This work is purely a physical measurement in the laboratory. To the best of our knowledge, this is the first quantitative study on the level of gamma rays protection offered by the medical lead aprons and the importance of the spectroscopic measurements is discussed in this paper.

Gold Nanocluster Decorated Polypeptide/DNA Complexes for NIR Light and Redox Dual-Responsive Gene Transfection

Endo/lysosomal escape and subsequent nuclear translocation are recognized as the two major challenges for efficient gene transfection. Herein, nuclear localization signal (NLS) peptide sequences and oligomeric lysine sequences were crosslinked via disulfide bonds to obtain glutathione (GSH) reducible polypeptide (pNLS). The pNLS could condense DNA into compact positive-charged complexes with redox sensitivity, and then gold nanoclusters (AuNC) were further decorated to the surface via electrostatic interactions obtaining versatile pNLS/DNA/AuNC complexes. The AuNC could generate reactive oxygen species (ROS) under NIR-irradiation and accelerate the endo/lysosomal escape of the complexes, and then the pNLS sequence degraded by GSH in cytoplasm would release the DNA and facilitate the subsequent nuclear translocation for enhanced gene transfection.

Highly Integrated Nano-Platform for Breaking the Barrier between Chemotherapy and Immunotherapy

Fighting metastasis is a major challenge in cancer therapy, and stimulation of the immune system is of particular importance in the treatment of metastatic cancers. Here, an integrated theranostic nanoplatform was developed for the efficient treatment of highly metastatic tumors. Versatile functions including "And" logically controlled drug release, prolonged circulation time, tumor targeting, and anti-metastasis were integrated into doxorubicin (DOX) loaded, highly integrated mesoporous silica nanoparticles (DOX@HIMSNs) for a systemic treatment of highly metastatic triple negative breast cancer (TNBC). It was found that the good therapeutic effect of DOX@HIMSN was only partially attributed to its anticancer cytotoxicity. Most importantly, DOX@HIMSN could induce anticancer immune responses including dendritic cell (DC) maturation and antitumor cytokine release. Compared with the traditional tumor chemotherapy, the integrated theranostic nanoplatform we developed not only improved the tumor specific cytotoxicity but also stimulated antitumor immune responses during the treatment.

Hydrogen peroxide detection with high specificity in living cells and inflamed tissues

Hydrogen peroxide (H2O2) detection in biological systems is of significant importance, which act as critical second messenger in fundamental biological processes. Here, we report on a chemoselective fluorescent naphthylimide peroxide probe (NPP) for the H2O2 detection in vitro and in vivo. NPP is a phenylboronic acid-caged chromophore that selectively responds to H2O2 through a self-immolate mechanism. NPP exhibited high sensitivity and selectivity to H2O2 with distinctive fluorescence change due to the excellent two-photon excitation property, which permits the facile detection of inflammation produced H2O2 and offers chance to monitor the inflammatory stages in diseased cells.

Sirt 1 activator attenuates the bleomycin-induced lung fibrosis in mice via inhibiting epithelial-to-mesenchymal transition (EMT)

OBJECTIVE

The aim of this study was to investigate the effect of resveratrol on the idiopathic bleomycin (BLM)-induced pulmonary fibrosis, which is increasingly recognized as an epithelial-to-mesenchymal transition (EMT)-associated disease.

MATERIALS AND METHODS

We evaluated the effect of resveratrol on the BLM-induced fibrosis in a mouse model, via monitoring the pathological chance in mice lung, the mice body weight change and the mice death. And we also explored the regulation by BLM on (and) resveratrol on the expression and activity of Sirt 1 and on the expression of epithelial-to-mesenchymal transition (EMT)-associated markers in mice lung.

RESULTS

It was demonstrated that resveratrol ameliorated the BLM-induced fibrosis-like pathological change in mice lung, inhibited BLM-induced mice body weight loss and death. Moreover, resveratrol also inhibited the BLM-induced EMT-associated molecular events, such as reduced E-cadherin and elevated Collagen I and α-SMA. We also confirmed the amelioration by resveratrol on the BLM-mediated inhibition of Sirt 1 in expression and activity in mice lung.

CONCLUSIONS

Our study confirmed the inhibitory role of resveratrol in the BLM-induced pulmonary fibrosis in a mouse model. Resveratrol ameliorated the BLM-induced pathological change of fibrosis, mice body weight loss and death. And such amelioration might be associated with the activation of Sirt 1 in mice lung. The present study implied that resveratrol might be a promising agent for effective control the pulmonary fibrosis.

A Two-Photon Excitation Based Fluorogenic Probe for Sialome Imaging in Living Systems

Taking advantage of the fluorescence property of alkyne-modified naphthalimide, the two-photon excited fluorogenic probe Naph-yne is used for azide-tagged mannosyl glycoprotein imaging both at the cellular level and for vertebrate model organisms.

A surface charge-switchable and folate modified system for co-delivery of proapoptosis peptide and p53 plasmid in cancer therapy

To improve the tumor therapeutic efficiency and reduce undesirable side effects, ternary FK/p53/PEG-PLL(DA) complexes with a detachable surface shielding layer were designed. The FK/p53/PEG-PLL(DA) complexes were fabricated by coating the folate incorporated positively charged FK/p53 complexes with charge-switchable PEG-shield (PEG-PLL(DA)) through electrostatic interaction. At the physiological pH 7.4 in the bloodstream, PEG-PLL(DA) could extend the circulating time by shielding the positively charged FK/p53 complexes. After the accumulation of the FK/p53/PEG-PLL(DA) complexes in tumor sites, tumor-acidity-triggered charge switch led to the detachment of PEG-PLL(DA) from the FK/p53 complexes, and resulted in efficient tumor cell entry by folate-mediated uptake and electrostatic attraction. Stimulated by the high content glutathione (GSH) in cytoplasm, the cleavage of disulfide bond resulted in the liberation of proapoptosis peptide C-KLA(TPP) and the p53 gene, which exerted the combined tumor therapy by regulating both intrinsic and extrinsic apoptotic pathways. Both in vitro and in vivo studies confirmed that the ternary detachable complexes FK/p53/PEG-PLL(DA) could enhance antitumor efficacy and reduce adverse effects to normal cells. These findings indicate that the tumor-triggered decomplexation of FK/p53/PEG-PLL(DA) supplies a useful strategy for targeting delivery of different therapeutic agents in synergetic anticancer therapy.

Immunosuppression of breast cancer cells mediated by transforming growth factor-β in exosomes from cancer cells

Exosomes derived from tumor cells are essential for processes involved in tumor progression, including angiogenesis, tumor cell proliferation and immunoregulation. In addition, exosome secretion may contribute to the mechanisms of hypoxia-induced angiogenesis and metastasis of tumors. In the present study, as it is one of the most common cancers in females, breast cancer, cell lines were cultured under hypoxic (1% O₂) and normoxic conditions to evaluate the effects of hypoxia on exosome production. Under hypoxic conditions an increase in the number of exosomes in the medium, determined by CD63 immunoblotting, was observed. Application of these exosomes to T cells revealed that they were able to suppress T cell proliferation. As transforming growth factor-β (TGF-β), interleukin-10, and prostaglandin E2 are important factors in the mediation of T cell suppression, the exosomes were subsequently treated with antibodies against these three factors. The results revealed that anti-TGF-β was capable of ameliorating the immunosuppressive effects of exosomes. These data demonstrate that hypoxia enhances the secretion of exosomes by breast cancer cells, which acts to suppress T cell proliferation via TGF-β. The findings have significant implications for understanding the underlying mechanisms of immunosuppression in tumor microenvironments, and for the potential development of cancer therapies.

An innovative pre-targeting strategy for tumor cell specific imaging and therapy

A programmed pre-targeting system for tumor cell imaging and targeting therapy was established based on the "biotin-avidin" interaction. In this programmed functional system, transferrin-biotin can be actively captured by tumor cells with the overexpression of transferrin receptors, thus achieving the pre-targeting modality. Depending upon avidin-biotin recognition, the attachment of multivalent FITC-avidin to biotinylated tumor cells not only offered the rapid fluorescence labelling, but also endowed the pre-targeted cells with targeting sites for the specifically designed biotinylated peptide nano-drug. Owing to the successful pre-targeting, tumorous HepG2 and HeLa cells were effectively distinguished from the normal 3T3 cells via fluorescence imaging. In addition, the self-assembled peptide nano-drug resulted in enhanced cell apoptosis in the observed HepG2 cells. The tumor cell specific pre-targeting strategy is applicable for a variety of different imaging and therapeutic agents for tumor treatments.

Self-defensive nano-assemblies from camptothecin-based antitumor drugs

Camptothecin (CPT)-based drugs always undergo the reversible, pH-dependent lactone ring-opening reaction, yielding the inactive but toxic carboxylate form. Self-assembly strategy provides an effective route for preserving their bio-stability. In this article, nano-sized self-assemblies from CPT-based antitumor drugs were simply built up by directly diluting the stock dimethylsulfoxide solutions of (S)-(+)-CPT, (S)-10-hydroxyl camptothecin and carboxylic CPT with water/phosphate-buffered saline solution. Because of their different molecular structures in A-ring or modification on the 20-OH group, CPT self-assembled into helical nano-ribbons, whereas 10-hydroxycamptothecin and carboxylic CPT self-aggregated into flat nano-ribbons and cylindric nano-rods, respectively. Attractively, the self-assembly of CPT-based drugs could occur within 1 min at a low concentration of 1 × 10⁻⁵M. Adopting the J-type self-aggregation, self-assemblies were stable in aqueous solution and could effectively protect the CPT-based drugs from hydrolysis, which thereby kept their bioactivity for tumor therapy.

A pH-responsive prodrug for real-time drug release monitoring and targeted cancer therapy

A novel cancer targeting and pH-responsive prodrug was successfully designed and synthesized. This M-prodrug was demonstrated to have real-time drug release monitoring capability based on the concept of contact-mediated quenching between doxorubicin and a coumarin derivative.

Co-delivery of proapoptotic peptide and p53 DNA by reduction-sensitive polypeptides for cancer therapy

The xPolyR₈–KLA(TPP)/p53 complex releases the p53 gene and C-KLA(TPP) in the cytoplasm, and initiates a more efficient cell apoptosis due to the regulation of both apoptotic pathways through p53 and C-KLA(TPP).

Long-term thiol monitoring in living cells using bioorthogonal chemistry

A bioorthogonal chemistry based fluorescent probe is reported, which is capable of monitoring intracellular thiols in living cells on a 36 hour timescale with an obvious blue-to-green fluorescence change.

Characterization and molecular mapping of stripe rust resistance gene Yr61 in winter wheat cultivar Pindong 34

We report a new stripe rust resistance gene on chromosome 7AS in wheat and molecular markers useful for transferring it to other wheat genotypes. Several new races of the stripe rust pathogen have established throughout the wheat growing regions of China in recent years. These new races are virulent to most of the designated seedling resistance genes limiting the resistance sources. It is necessary to identify new genes for diversification and for pyramiding different resistance genes in order to achieve more durable resistance. We report here the identification of a new resistance gene, designated as Yr61, in Chinese wheat cultivar Pindong 34. A mapping population of 208 F2 plants and 128 derived F2:3 lines in a cross between Mingxian 169 and Pindong 34 was evaluated for seedling stripe rust response. A genetic map consisting of eight resistance gene analog polymorphism (RGAP), two sequence-tagged site (STS) and four simple sequence repeat (SSR) markers was constructed. Yr61 was located on the short arm of chromosome 7A and flanked by RGAP markers Xwgp5467 and Xwgp5765 about 1.9 and 3.9 cM in distance, which were successfully converted into STS markers STS5467 and STS5765b, respectively. The flanking STS markers could be used for marker-assisted selection of Yr61 in breeding programs.