The Hyperproliferation Mechanism of Cholesteatoma Based on Proteomics: SNCA Promotes Autophagy-Mediated Cell Proliferation Through the PI3K/AKT/CyclinD1 Signaling Pathway.

Cholesteatoma is a chronic inflammatory ear disease with abnormal keratinized epithelium proliferation and tissue damage. However, the mechanism of keratinized epithelium hyperproliferation in cholesteatoma remains unknown. Hence, our study sought to shed light on mechanisms affecting the pathology and development of cholesteatoma, which could help develop adjunctive treatments. To investigate molecular changes in cholesteatoma pathogenesis, we analyzed clinical cholesteatoma specimens and paired ear canal skin with mass spectrometry-based proteomics and bioinformatics. From our screen, alpha-synuclein (SNCA) was overexpressed in middle ear cholesteatoma and might be a key hub protein associated with inflammation, proliferation, and autophagy in cholesteatoma. SNCA was more sensitive to lipopolysaccharide-induced inflammation, and autophagy marker increase was accompanied by autophagy activation in middle ear cholesteatoma tissues. Overexpression of SNCA activated autophagy and promoted cell proliferation and migration, especially under lipopolysaccharide inflammatory stimulation. Moreover, inhibiting autophagy impaired SNCA-mediated keratinocyte proliferation and corresponded with inhibition of the PI3K/AKT/CyclinD1 pathways. Also, 740Y-P, a PI3K activator reversed the suppression of autophagy and PI3K signaling by siATG5 in SNCA-overexpressing cells, which restored proliferative activity. Besides, knockdown of SNCA in RHEK-1 and HaCaT cells or knockdown of PI3K in RHEK-1 and HaCaT cells overexpressing SNCA both resulted in attenuated cell proliferation. Our studies indicated that SNCA overexpression in cholesteatoma might maintain the proliferative ability of cholesteatoma keratinocytes by promoting autophagy under inflammatory conditions. This suggests that dual inhibition of SNCA and autophagy may be a promising new target for treating cholesteatoma.

Comparative single-cell RNA sequencing analysis of immune response to inactivated vaccine and natural SARS-CoV-2 infection.

Uncovering the immune response to an inactivated SARS-CoV-2 vaccine (In-Vac) and natural infection is crucial for comprehending COVID-19 immunology. Here we conducted an integrated analysis of single-cell RNA sequencing (scRNA-seq) data from serial peripheral blood mononuclear cell (PBMC) samples derived from 12 individuals receiving In-Vac compared with those from COVID-19 patients. Our study reveals that In-Vac induces subtle immunological changes in PBMC, including cell proportions and transcriptomes, compared with profound changes for natural infection. In-Vac modestly upregulates IFN-α but downregulates NF-κB pathways, while natural infection triggers hyperactive IFN-α and NF-κB pathways. Both In-Vac and natural infection alter T/B cell receptor repertoires, but COVID-19 has more significant change in preferential VJ gene, indicating a vigorous immune response. Our study reveals distinct patterns of cellular communications, including a selective activation of IL-15RA/IL-15 receptor pathway after In-Vac boost, suggesting its potential role in enhancing In-Vac-induced immunity. Collectively, our study illuminates multifaceted immune responses to In-Vac and natural infection, providing insights for optimizing SARS-CoV-2 vaccine efficacy.

Vitamin D plays a protective role in osteoarthritis by regulating AMPK/mTOR signalling pathway to activate chondrocyte autophagy.

OBJECTIVES: The deletion of chondrocyte autophagy seems to play a key role in the pathogenesis of osteoarthritis (OA). Patients with OA often have vitamin D (VD) deficiency, and VD supplementation can improve pain and alleviate the progression of joint structures in patients. In this study, we aimed to investigate whether VD could enhance autophagy by activating the adenosine monophosphate activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) signalling pathway and protect against OA. METHODS: In this study, the levels of target proteins and genes were examined by western blot and qRT-PCR. Apoptotic cells were detected using TUNEL staining. Characteristics of autophagy were observed by LysoTracker red staining, mRFP-GFP-LC3 adenovirus transfection, and transmission electron microscopy. siRNA-mediated AMPK and mTOR knockdown were used to investigate the role of the AMPK/ mTOR signalling pathway in VD-induced autophagy. Haematoxylin and eosin and safranin-O/fast green staining were used detect cartilage alterations. RESULTS: We suggested that VD significantly reduced chondrocyte death and alleviated extracellular matrix degradation. Further studies showed that VD promoted the expression of the autophagy-related protein LC3II through the AMPK/mTOR signalling pathway in chondrocytes, activated lysosome activity, promoted the formation of autophagy-associated lysosomes, which played a crucial role in the degradation of intracellular organelles and maintained homeostasis. The anti-apoptotic effect of VD on chondrocytes was associated with the activation of autophagy. The group of AMPK-normal and mTOR-knockdown in the presence of VD inhibited chondrocyte apoptosis by promoting autophagy. CONCLUSIONS: This study highlights that VD can activate chondrocyte autophagy through the AMPK/mTOR signalling pathway.

Spatio-Temporal Feature Transformation Based Polyp Recognition for Automatic Detection: Higher Accuracy than Novice Endoscopists in Colorectal Polyp Detection and Diagnosis.

BACKGROUND: Artificial intelligence represents an emerging area with promising potential for improving colonoscopy quality. AIMS: To develop a colon polyp detection model using STFT and evaluate its performance through a randomized sample experiment. METHODS: Colonoscopy videos from the Digestive Endoscopy Center of the First Affiliated Hospital of Anhui Medical University, recorded between January 2018 and November 2022, were selected and divided into two datasets. To verify the model's practical application in clinical settings, 1500 colonoscopy images and 1200 polyp images of various sizes were randomly selected from the test set and compared with the STFT model's and endoscopists' recognition results with different years of experience. RESULTS: In the randomized sample trial involving 1500 colonoscopy images, the STFT model demonstrated significantly higher accuracy and specificity compared to endoscopists with low years of experience (0.902 vs. 0.809, 0.898 vs. 0.826, respectively). Moreover, the model's sensitivity was 0.904, which was higher than that of endoscopists with low, medium, or high years of experience (0.80, 0.896, 0.895, respectively), with statistical significance (P < 0.05). In the randomized sample experiment of 1200 polyp images of different sizes, the accuracy of the STFT model was significantly higher than that of endoscopists with low years of experience when the polyp size was ≤ 0.5 cm and 0.6-1.0 cm (0.902 vs. 0.70, 0.953 vs. 0.865, respectively). CONCLUSIONS: The STFT-based colon polyp detection model exhibits high accuracy in detecting polyps in colonoscopy videos, with a particular efficiency in detecting small polyps (≤ 0.5 cm)(0.902 vs. 0.70, P < 0.001).

Fractional exhaled nitric oxide in idiopathic pulmonary arterial hypertension and mixed connective tissue disease complicating pulmonary hypertension.

BACKGROUND: Fractional exhaled nitric oxide (FeNO) has been extensively studied in various causes of pulmonary hypertension (PH), but its utility as a noninvasive marker remains highly debated. The objective of our study was to assess FeNO levels in patients with idiopathic pulmonary arterial hypertension (IPAH) and mixed connective tissue disease complicating pulmonary hypertension (MCTD-PH), and to correlate them with respiratory functional data, disease severity, and cardiopulmonary function. METHODS: We collected data from 54 patients diagnosed with IPAH and 78 patients diagnosed with MCTD-PH at the Shanghai Pulmonary Hospital Affiliated to Tongji University. Our data collection included measurements of brain natriuretic peptide (pro-BNP), cardiopulmonary exercise test (CPET), pulmonary function test (PFT), impulse oscillometry (IOS), and FeNO levels. Additionally, we assessed World Health Organization functional class (WHO-FC) of each patient. RESULTS: (1) The fractional exhaled concentration of nitric oxide was notably higher in patients with IPAH compared to those with MCTD-PH. Furthermore, within the IPAH group, FeNO levels were found to be lower in cases of severe IPAH compared to mild IPAH (P = 0.024); (2) In severe pulmonary hypertension as per the WHO-FC classification, FeNO levels in IPAH exhibited negative correlations with FEV1/FVC (Forced Expiratory Velocity at one second /Forced Vital Capacity), MEF50% (Maximum Expiratory Flow at 50%), MEF25%, and MMEF75/25% (Maximum Mid-expiratory Flow between 75% and 25%), while in severe MCTD-PH, FeNO levels were negatively correlated with R20% (Resistance at 20 Hz); (3) ROC (Receiving operator characteristic curve) analysis indicated that the optimal cutoff value of FeNO for diagnosing severe IPAH was 23ppb; (4) While FeNO levels tend to be negatively correlated with peakPETO2(peak end-tidal partial pressure for oxygen) in severe IPAH, in mild IPAH they had a positive correlation to peakO2/Heart rate (HR). An interesting find was observed in cases of severe MCTD-PH, where FeNO levels were negatively correlated with HR and respiratory exchange ratio (RER), while positively correlated with O2/HR throughout the cardiopulmonary exercise test. CONCLUSION: FeNO levels serve as a non-invasive measure of IPAH severity. Although FeNO levels may not assess the severity of MCTD-PH, their significant makes them a valuable tool when assessing severe MCTD-PH.

Ultrafast Electron Transfer Dynamics of Organic Polymer Nanoparticles with Graphene Oxide.

We prepared organic polymer poly-3-hexylthiophene (p3ht) nanoparticles (NPs) and graphene oxide (GO)/reduced graphene oxide (RGO) composites p3ht NPs-GO/RGO by using the reprecipitation method. We demonstrated that GO/RGO could improve the ordering and planarity of p3ht chains as well as the formation of p3ht NPs, and confirmed the effects of GO/RGO on the fluorescence and carrier transport dynamics of p3ht NPs by using femtosecond fluorescence upconversion and transient absorption (TA) techniques. Ultrafast electron transfer (∼1 ps) between GO/RGO and p3ht NPs quenched the fluorescence of p3ht NPs, indicating excellent properties of p3ht NPs-GO/RGO as the charge transfer complexes. Efficient electron transfer may promote the applications of p3ht NPs-GO/RGO composites in organic polymer solar cells and photocatalysis. Moreover, RGO had stronger interfacial interactions and more matched conduction band energy levels with p3ht NPs than GO did, which implied that p3ht NPs-RGO might have greater application values than p3ht NPs-GO.

Monitoring the Micro-Structural Evolution Mechanism of Next-Generation Ultra-High-Energy All-Nitrogen Materials: A Molecular Dynamic Study.

Micro-structural evolution mechanisms of next-generation ultra-high-energy all-nitrogen materials under the extreme conditions of high temperature coupled with high pressure were revealed by state-of-the-art ab initio molecular dynamics studies based on highest-nitrogen-content energetic material 2,2'-azobis(5-azidotetrazole). The results indicate that there are three primary initial uni-molecular decomposition pathways, namely, tetrazole ring opening, azido group elimination, and the breaking of the N-N bond between the azo group and azidotetrazole. In complicated global decomposition reactions, there exists the formation of nitrogen-rich clusters and all-nitrogen species. Lowering the temperature or increasing the pressure is conducive to increasing the N content in the nitrogen-rich cluster and widening the time distribution for the cluster. Abundant all-nitrogen species N4, N5, N6, N7, N8, N9, N10, and N13 were formed, and their detailed evolutionary process and construction mechanisms were enunciated. We innovatively constructed a series of next-generation ultra-high-energy all-nitrogen materials, which are expected to realize the controllable construction of next-generation ultra-high-energy all-nitrogen materials under extreme conditions.

Ultrafast Förster resonance energy transfer from tyrosine to tryptophan in monellin: potential intrinsic spectroscopic ruler.

Ultrafast Förster Resonance Energy Transfer (FRET) between tyrosine (Tyr) and tryptophan (Trp) residues in the protein monellin has been investigated using picosecond and femtosecond time-resolved fluorescence spectroscopy. Decay associated spectra (DAS) and time-resolved emission spectra (TRES) taken with the different excitation wavelengths of 275, 290 and 295 nm were constructed via global analysis. At two of those three excitation loci (275 and 290 nm), earmarks of energy transfer from Tyr to Trp in monellin are seen, and particularly when the excitation is 275 nm, the energy transfer between Tyr and Trp clearly changes the signature emission DAS shape to that indicating excited state reaction (especially on the red side of fluorescence emission, near 380 nm). Those FRET signatures may overlap with the conventional signatory DAS in heterogeneous systems. When overlap and addition occur between FRET type DAS and "full positive" QSSQ (quasi-static self-quenching), mixed DAS shapes will emerge that still show "positive blue side and negative red sides", just with zero crossing shifted. In addition, excitation decay associated spectra (EDAS) taken with the different emission wavelengths of 330, 350 and 370 nm were constructed. In the study of protein dynamics, ultrafast FRET between Tyr and Trp could provide a basis for an intrinsic (non-perturbing) "spectroscopic ruler", potentially a powerful tool to detect even slight changes in protein structures.

Phase transition-induced initial decomposition of nitrogen-rich binary CN compound 2,2'-azobis(5-azidotetrazole) and its precursor 2-amino-5-azidotetrazole via tetrazole ring opening under external electric fields: a comparative DFT-D study.

A comparative DFT-D study was performed to investigate the external electric field-induced crystal structures, electronic features, Hirshfeld surfaces, vibrational properties and initial decomposition mechanisms of nitrogen-rich binary CN compound 2,2'-azobis(5-azidotetrazole) (C2N16) and its precursor 2-amino-5-azidotetrazole (CH2N8). The results show that there exist phase transitions at the critical points of 0.006 a.u. and 0.008 a.u. for CH2N8 and C2N16, respectively, which are embodied in various properties of these compounds and induce their initial decomposition of the tetrazole ring opening via the breaking of N-N single bonds. The analysis of band gaps and density of states suggests the external electric field-induced enhancing ability for electron transition from the occupied orbitals to empty ones and N-N bond breaking may be the initial decomposition pathway for them. The variations in Hirshfeld surfaces indicate the spatial change and adjustment of non-bonding interactions in the two crystals. The discussions on vibrational properties indicate that IR characteristic peaks of all vibrational modes in the two crystals show a gradual red shift toward a low frequency region. The external electric field-induced initial decomposition pathways of both crystals are tetrazole ring opening via the breaking of a N-N single bond. Our findings provide insights for a comprehensive understanding of external electric field-induced phase transition and initial decomposition mechanisms of nitrogen-rich binary CN energetic compounds.

Diagnostic Significance of DCE-MRI-Related Quantitative Parameters for Nasal Cavity and Sinus Tumors.

Objective: Our aim was to explore the diagnostic value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI)-related quantitative parameters for benign and malignant nasal cavity and sinus tumors. Methods: A total of 78 patients with nasal sinus tumors admitted to People's Hospital of Qingdao Chengyang District in China were enrolled in our study, Of the patients, 41 were diagnosed as having benign tumors and 37 as having malignant tumors by pathological diagnosis. All patients received DCE-MRI scans before surgery to derive time-intensity curves (TICs) and related quantitative parameters (flux rate constant [Kep], transfer constant [Ktrans], extravascular volume fraction [Ve]). The diagnostic surgical pathology results were used as the gold standard to analyze the diagnostic effect of TIC and related quantitative parameters of DCE-MRI, and the receiver operating characteristic (ROC) curves were plotted to determine the values of each parameter in predicting nasal sinus tumors. Results: The percentage of class I in the benign group was significantly higher than in the malignant group (P < .05); the percentage of class III in the benign group was significantly lower than in the malignant group (P < .05); the percentage of class II in the 2 groups was comparable (P > .05). Kep, Ktrans and Ve in the benign group were 0.338±0.124, 0.061±0.035 and 0.532±0.138, respectively; Kep, Ktrans and Ve in the malignant group were 0.785±0.211, 0.441±0.125 and 0.327±0.048, respectively. The levels of Kep and Ktrans were significantly lower in the benign group than in the malignant group (all P < .05); the levels of Ve were significantly higher in the benign group than in the malignant group (P < .05). The optimal Kep cut-off value for predicting malignant nasal sinus tumors was 0.510 min-1, with a sensitivity of 81.4% and specificity of 89.5%; the optimal Ktrans cut-off value for predicting malignant nasal sinus tumors was 0.206 min-1, with a sensitivity of 84.3% and specificity of 89.7%; the optimal Ve cut-off value for predicting malignant nasal sinus tumors was 0.384 min-1, with a sensitivity of 71.8% and specificity of 82.4%. Conclusion: DCE-MRI-related quantitative parameters are ideal for the diagnosis of benign and malignant nasal sinus tumors. This modality provides more data for the identification of the nature of the tumor, and thus merits clinical promotion and application.

Comparison of short-term and long-term clinical effects of modified overlap anastomosis and conventional incision-assisted anastomosis in laparoscopic total gastrectomy.

BACKGROUND: To compare short-term and long-term clinical effects of modified overlap anastomosis and conventional incision-assisted anastomosis for laparoscopic total gastrectomy. METHODS: This retrospective cohort study included patients with gastric cancer admitted to the Second Affiliated Hospital of Fujian Medical University from January 2016 to March 2020. Quality of life, intraoperative and postoperative conditions were analyzed. RESULTS: Compared with the conventional assisted group, the modified overlap group showed a shorter auxiliary incision, milder postoperative pain, shorter time to the first postoperative anal exhaust, shorter time to the first postoperative liquid food intake, and shorter postoperative stay. There were no differences between the two groups regarding operation time, esophagus-jejunum anastomosis time, intraoperative blood loss, number of lymph nodes dissected, and length of the upper incision margin. There were no differences between the two groups regarding postoperative early and late complications. There were no differences between the two groups regarding the QLQ-C30 scale three years after the operation. The scores of the QLQ-STO22 scale 3 years after the operation showed significantly lower scores for dysphagia and feeding limit in the modified overlap group than those in the conventional assisted anastomosis group. There was no recurrence in the modified overlap group but one patient in the conventional assisted group. CONCLUSIONS: Patients undergoing totally laparoscopic total gastrectomy with modified overlap anastomosis have better minimal invasiveness and faster post-operative recovery than conventional incision-assisted anastomosis.

Systematic review of machine learning-based radiomics approach for predicting microsatellite instability status in colorectal cancer.

This study aimed to systematically summarize the performance of the machine learning-based radiomics models in the prediction of microsatellite instability (MSI) in patients with colorectal cancer (CRC). It was conducted according to the preferred reporting items for a systematic review and meta-analysis of diagnostic test accuracy studies (PRISMA-DTA) guideline and was registered at the PROSPERO website with an identifier CRD42022295787. Systematic literature searching was conducted in databases of PubMed, Embase, Web of Science, and Cochrane Library up to November 10, 2022. Research which applied radiomics analysis on preoperative CT/MRI/PET-CT images for predicting the MSI status in CRC patients with no history of anti-tumor therapies was eligible. The radiomics quality score (RQS) and Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) were applied to evaluate the research quality (full score 100%). Twelve studies with 4,320 patients were included. All studies were retrospective, and only four had an external validation cohort. The median incidence of MSI was 19% (range 8-34%). The area under the receiver operator curve of the models ranged from 0.78 to 0.96 (median 0.83) in the external validation cohort. The median sensitivity was 0.76 (range 0.32-1.00), and the median specificity was 0.87 (range 0.69-1.00). The median RQS score was 38% (range 14-50%), and half of the studies showed high risk in patient selection as evaluated by QUADAS-2. In conclusion, while radiomics based on pretreatment imaging modalities had a high performance in the prediction of MSI status in CRC, so far it does not appear to be ready for clinical use due to insufficient methodological quality.

Lucialdehyde B suppresses proliferation and induces mitochondria-dependent apoptosis in nasopharyngeal carcinoma CNE2 cells.

CONTEXT: Lucialdehyde B (LB), an effective triterpenoid isolated from Ganoderma lucidum (Leyss. ex Fr.) Karst. (Polyproraceae), exerts cytotoxic activity against nasopharyngeal carcinoma CNE2 cells. OBJECTIVE: To investigate the antiproliferative and pro-apoptotic effects of LB on CNE2 cells and explore its underlying mechanisms. MATERIALS AND METHODS: LB concentrations of 5-40 µg/mL were used. Cell proliferation was determined using MTT, CFSE, and colony formation assays. LB-induced apoptosis and cell cycle arrest were measured by flow cytometry after 48-h LB treatments. Fluorescence microscopy and flow cytometry were performed to measure the alteration of MMP, mPTP opening, ROS level, and Ca2+ content in CNE2 cells. Western blotting was performed to evaluate the expression of mitochondrial apoptosis-related and Ras/ERK signaling proteins. RESULTS: IC50 values of LB against CNE2 cells for 24, 48, and 72 h were 25.42 ± 0.87, 14.83 ± 0.93, and 11.60 ± 0.77 µg/mL, respectively. The CFSE assay showed that the cell proliferation index was 12.70 in the LB treatment group and 31.44 in the control group. LB significantly reduced clonogenic capacity, promoted cell apoptosis and induced cell cycle arrest at the G2/M phase. Our observations also revealed that LB induced ROS and calcium aggregation, opening of mPTP, MMP reduction, upregulation of mitochondrial apoptosis-related protein expression and inhibition of Ras/ERK signaling cascades. DISCUSSION: LB suppresses proliferation and induces mitochondrial-dependent apoptosis in nasopharyngeal carcinoma CNE2 cells. CONCLUSIONS: LB may have a potential use as a clinical drug candidate for nasopharyngeal carcinoma treatment.

Leflunomide versus azathioprine for maintenance therapy of lupus nephritis: a prospective, multicentre, randomised trial and long-term follow-up.

OBJECTIVES: Previous studies have compared mycophenolate mofetil and azathioprine as maintenance therapy for lupus nephritis (LN). Leflunomide is an immunosuppressant widely used in the treatment of rheumatoid arthritis. The aim of this investigator-initiated study was to compare the efficacy and safety of leflunomide versus azathioprine as maintenance therapy for LN. METHODS: 270 adult patients with biopsy-confirmed active LN from 7 Chinese Rheumatology Centres were enrolled. All patients received induction therapy with 6-9 months of intravenous cyclophosphamide plus glucocorticoids. Patients who achieved complete response (CR) or partial response (PR) were randomised to receive prednisone in combination with leflunomide or azathioprine as maintenance therapy for 36 months. The primary efficacy endpoint was the time to kidney flare. Secondary outcomes included clinical parameters, extrarenal flare and adverse effects. RESULTS: A total of 215 patients were randomly allocated to the leflunomide group (n=108) and azathioprine group (n=107). Kidney flares were observed in 17 (15.7%) leflunomide-treated patients and 19 (17.8%) azathioprine-treated patients. Time to kidney flare did not statistically differ (leflunomide: 16 months vs azathioprine: 14 months, p=0.676). 24-hour proteinuria, serum creatinine, serum albumin, serum C3 and serum C4 improved similarly. Extrarenal flare occurred in two patients from the azathioprine group and one patient from the leflunomide group. The incidence of adverse events was similar in the 2 groups: leflunomide 56.5% and azathioprine 58.9%. CONCLUSIONS: The efficacy and safety profile of leflunomide are non-inferior to azathioprine for maintenance therapy of LN. Leflunomide may provide a new candidate for maintenance therapy in patients with LN. TRIAL REGISTRATION NUMBER: NCT01172002.

Long-term variability of impulse oscillometry and spirometry in stable COPD and asthma.

BACKGROUND: While optimizing spirometry is a challenge for lung function labs, long-term variability if any between IOS (impulse oscillometry) parameters and spirometry is not clearly known in stable COPD (chronic obstructive pulmonary disease) and chronic asthma. The forced oscillation technique is increasingly employed in routine lung function testing. Our aim in this study was to determine the variability in oscillometric parameters between clinic visits over weeks or months in two patient groups during a period of clinical stability. Moreover, the research assessed relationships between IOS parameters long-term variability and COPD severity. METHODS: We used data from 73 patients with stable COPD and 119 patients with stable asthma at the Shanghai Pulmonary Hospital Affiliated to Tongji University. Patients were included if they had three or more clinic visits where spirometry and IOS were performed during a clinically stable period. Data recorded from the first three visits were used. The standard deviation (SDbv), the coefficient of variation (COV), intraclass correlation coefficient (ICC) and the coefficient of repeatability (COR) were calculated, Wilcoxon Mann-Whitney test was used for data that did not conform to normality of distributions, Kruskal Wallis test was used to compare with multiple groups, post hoc comparison was analyzed by Bonferroni, Spearman correlation coefficients for non-parametric data, the multiple regression analyses to determine the relationship between long-term variability and airflow obstruction. RESULTS: (1) The repeatability of IOS resistance parameters with ICC values > 0.8 was high in COPD and asthma. ICC values of IOS resistance parameters were higher than IOS reactance parameters; (2) the repeatability of spirometry parameters with ICC values < 0.8 was lower than IOS resistance parameters in different GOLD (the Global Initiative for Chronic Obstructive Lung Disease) stages, the higher the stage the worse the repeatability; (3) the severity of airflow obstruction was correlated with long-term variability of R5 (R at 5 Hz) (P < 0.05) in GOLD4, not with long-term variability of R20 (R at 20 Hz) (P > 0.05) and R5-R20 (P > 0.05). CONCLUSION: IOS resistance parameters have good long-term repeatability in asthma and COPD. Additionally, repeatability of spirometry parameters is lower than IOS resistance parameters in different GOLD stages.

Synthesis of novel dual target inhibitors of PARP and EGFR and their antitumor activities in triple negative breast cancers.

The therapeutic strategy of poly (ADP-ribose) polymerase (PARP) inhibition of BRCA1/2 mutant cancers has been overwhelmingly successful, however, the highly aggressive triple negative breast cancers (TNBC) that receptor protein tyrosine kinase (RTKs) is known to be overexpressed are not sensitive to PARP inhibitors. Our research focused on exploring PARP inhibitors incorporating a bicyclic tetrahydropyridine pyrimidine. All synthesized compounds were more potent than Olaparib (ola) in killing tumor cells, especially in TNBC. Furthermore, compound 7 exhibited strong inhibitory effects on PARP enzymatic activity, moreover, the expression of EGFR and phosphorylated EGFR was inhibited by compound 7. Therefore, compound 7 can effectively inhibit TNBC cells with high expression of EGFR. In addition, significant synergistic effect of anti-tumor effect of new PARP inhibitors and adriamycin was also observed.

Discovery of CN0 as a novel proteolysis-targeting chimera (PROTAC) degrader of PARP1 that can activate the cGAS/STING immunity pathway combined with daunorubicin.

Poly ADP-ribose polymerase 1 (PARP1) plays an essential role in DNA repair signaling, rendering it an attractive target for cancer treatment. Despite the success of PARP1 inhibitors (PARPis), only a few patients can currently benefit from PARPis. Moreover, drug resistance to PARPis occurs during clinical treatment. Natural and acquired resistance to PARPis has forced us to seek new therapeutic approaches that target PARP1. Here, we synthesized a series of compounds by proteolysis-targeting chimera (PROTAC) technology to directly degrade the PARP1 protein. We found that CN0 (compound 3) with no polyethylene glycol (PEG) linker can degrade the PARP1 protein through the proteasome pathway. More importantly, CN0 could inhibit DNA damage repair, resulting in highly efficient accumulation of cytosolic DNA fragments due to unresolved unrepaired DNA lesions when combined with daunorubicin (DNR). Therefore, CN0 can activate the cyclic GMP-AMP synthase/stimulator of the interferon gene (cGAS/STING) pathway of innate immunity and then spread the resulting inflammatory signals, thereby reshaping the tumor microenvironment, which may eventually enhance T cell killing of tumor cells.

Phase transition induced by an external electric field as a buffer to facilitate the initial decomposition of a series of catenated nitrogen energetic systems: a first-principles study.

The effect of an external electric field on the crystal and electronic structures, Hirshfeld surfaces, hydrogen-bonding network, mechanical properties, vibrational properties and initial decomposition mechanisms of a series of chain-catenated Nx (x = 4, 8, 10) energetic crystals was investigated via a first-principles study. The results indicate that the response behaviors to the external electric field show a great dependence on the nitrogen chain length and the intensity of the external electric field. The critical points of the phase transition were found and are embodied in various properties of all the compounds. Analysis of the electronic structures shows the increasing ability of the electron transition, thereby leading to possible subsequent decomposition reactions. The studies on Hirshfeld surfaces and the hydrogen-bonding network suggest that the external electric field can modify and tune the spatial distribution of the hydrogen-bonding network, thereby affecting the physicochemical properties. Our comprehensive analysis based on the mechanical properties, vibrational features and initial decomposition mechanism reveals that the external electric field can weaken the trigger bonds, reduce the thermal stability, and initiate decomposition. Our findings provide insights into the comprehensive understanding of the effects of an external electric field on energetic materials, especially for polynitrogen chain-catenated and even all-nitrogen compounds.

Ultrafast Förster resonance energy transfer between tyrosine and tryptophan: potential contributions to protein-water dynamics measurements.

Ultrafast Förster Resonance Energy Transfer (FRET) between Tyrosine (Tyr, Y) and Tryptophan (Trp, W) in the model peptides Trp-(Pro)n-Tyr (WPnY) has been investigated using a femtosecond up-conversion spectrophotofluorometer. The ultrafast energy transfer process (<100 ps) in short peptides (WY, WPY and WP2Y) has been resolved. In fact, this FRET rate is found to be mixed with the rates of solvent relaxation (SR), ultrafast population decay (QSSQ) and other lifetime components. To further dissect and analyze the FRET, a spectral working model is constructed, and the contribution of a FRET lifetime is separated by reconciling the shapes of decay associated spectra (DAS). Surprisingly, FRET efficiency did not decrease monotonically with the growth of the peptide chain (as expected) but increased first and then decreased. The highest FRET efficiency occurred in peptide WPY. The kinetic results have been accompanied with molecular dynamics simulations that reconcile and explain this strange phenomenon: due to the strong interaction between amino acids, the distance between the donor and receptor in peptide WPY is actually closest, resulting in the fastest FRET. In addition, the FRET lifetimes (τcal) were estimated within the molecular dynamics simulations, and they were consistent with the lifetimes (τexp) separated out by the experimental measurements and the DAS working model. This benchmark study has implications for both previous and future studies of protein ultrafast dynamics. The approach taken can be generalized for the study of proximate tyrosine and tryptophan in proteins and it suggests spectral strategies for extracting mixed rates in other complex FRET problems.

C0818, a novel curcumin derivative, induces ROS-dependent cytotoxicity in human hepatocellular carcinoma cells in vitro via disruption of Hsp90 function.

Heat shock protein 90 (Hsp90) is the most common molecular chaperone that controls the maturation of many oncoproteins critical in tumor development. Hsp90 has been considered as a promising target for cancer treatment, but the clinical significance of Hsp90 and the mechanisms of Hsp90 regulating the tumor-promoting effects in hepatocellular carcinoma (HCC) remain obscure. Previous studies have shown that curcumin, a polyphenol derived from the plant turmeric (Curcuma longa), inhibits tumor growth, which may provide an effective alternative therapy for HCC. Compared to curcumin, a novel derivative of curcumin, 3,5-(E)-Bis(3-methoxy-4-hydroxybenzal)-4-piperidinone hydrochloride (C0818) that is more potent in Hsp90 inhibition and antitumor activity. In this study, we investigated the effect of C0818 on HCC cells in vitro and its relation to Hsp90 inhibition. We showed that C0818 concentration-dependently inhibited the proliferation, the colony formation and induced apoptosis in HepG2 and Sk-Hep-1 cells. C0818 concentration-dependently inhibited DNA synthesis and induced G2/M phase arrest in HepG2 and Sk-Hep-1 cells. We further demonstrated that C0818 induced ROS- and caspase-dependent apoptosis in HCC cells through the mitochondrial-mediated pathway. C0818 induced the degradation of Hsp90 client proteins as RAS, C-Raf, P-C-Raf, Erk, P-ERK, MEK, P-MEK, Akt and P-Akt, which led to subsequent inhibition of the RAS/RAF/MEK/ERK and PI3K/AKT pathways. We revealed that C0818 could inhibit the binding of Hsp90 with its clients without affecting their transcription, which subsequently induced the degradation of Hsp90 clients by the proteasome rather than the lysosome. These results are of potential importance for elucidating a novel Hsp90 inhibitor targeting HCC.