Adipocyte-derived exosomal miR-22-3p modulated by circadian rhythm disruption regulates insulin sensitivity in skeletal muscle cells.

Circadian rhythm disruption leads to dysregulation of lipid metabolism, which further drive the occurrence of insulin resistance (IR). Exosomes are natural carrier systems that advantageous for cell communication. In the present study, we aimed to explore whether and how the exosomal microRNAs (miRNAs) in circulation participate in modulating skeletal muscle IR induced by circadian rhythm disruption. In the present study, 24-h constant light (12-h light/12-h light, LL) was used to establish the mouse model of circadian rhythm disruption. Bmal1 interference was used to establish the cell model of circadian rhythm disruption. And in clinical experiments, we chose a relatively large group of rhythm disturbance-shift nurses. We showed that LL-induced circadian rhythm disruption led to increased body weight and visceral fat volume, as well as occurrence of IR in vivo. Furthermore, exosomal miR-22-3p derived from adipocytes in the context of circadian rhythm disruption induced by Bmal1 interference could be uptaken by skeletal muscle cells to promote IR occurrence in vitro. Moreover, miR-22-3p in circulation was positively correlated with the clinical IR-associated factors. Collectively, these data showed that exosomal miR-22-3p in circulation may act as potential biomarker and therapeutic target for skeletal muscle IR, contributing to the prevention of diabetes in the context of rhythm disturbance.

BRCA1 secondary splice-site mutations drive exon-skipping and PARP inhibitor resistance.

PARP inhibitor (PARPi) therapy has transformed outcomes for patients with homologous recombination DNA repair (HRR) deficient ovarian cancers, for example those with BRCA1 or BRCA2 gene defects. Unfortunately, PARPi resistance is common. Multiple resistance mechanisms have been described, including secondary mutations that restore the HR gene reading frame. BRCA1 splice isoforms △11 and △11q can contribute to PARPi resistance by splicing out the mutation-containing exon, producing truncated, partially functional proteins. However, the clinical impacts and underlying drivers of BRCA1 exon skipping are not fully understood.We analyzed nine ovarian and breast cancer patient derived xenografts (PDX) with BRCA1 exon 11 frameshift mutations for exon skipping and therapy response, including a matched PDX pair derived from a patient pre- and post-chemotherapy/PARPi. BRCA1 exon 11 skipping was elevated in PARPi resistant PDX tumors. Two independent PDX models acquired secondary BRCA1 splice site mutations (SSMs) that drive exon skipping, confirmed using qRT-PCR, RNA sequencing, immunoblotting and minigene modelling. CRISPR/Cas9-mediated disruption of splicing functionally validated exon skipping as a mechanism of PARPi resistance. SSMs were also enriched in post-PARPi ovarian cancer patient cohorts from the ARIEL2 and ARIEL4 clinical trials.Few PARPi resistance mechanisms have been confirmed in the clinical setting. While secondary/reversion mutations typically restore a gene's reading frame, we have identified secondary mutations in patient cohorts that hijack splice sites to enhance mutation-containing exon skipping, resulting in the overexpression of BRCA1 hypomorphs, which in turn promote PARPi resistance. Thus, BRCA1 SSMs can and should be clinically monitored, along with frame-restoring secondary mutations.

Hypothalamic POMC neuron-specific knockout of MC4R affects insulin sensitivity by regulating Kir2.1.

BACKGROUND: Imbalance in energy regulation is a major cause of insulin resistance and diabetes. Melanocortin-4 receptor (MC4R) signaling at specific sites in the central nervous system has synergistic but non-overlapping functions. However, the mechanism by which MC4R in the arcuate nucleus (ARC) region regulates energy balance and insulin resistance remains unclear. METHODS: The MC4Rflox/flox mice with proopiomelanocortin (POMC) -Cre mice were crossed to generate the POMC-MC4Rflox/+ mice. Then POMC-MC4Rflox/+ mice were further mated with MC4Rflox/flox mice to generate the POMC-MC4Rflox/flox mice in which MC4R is selectively deleted in POMC neurons. Bilateral injections of 200 nl of AAV-sh-Kir2.1 (AAV-sh-NC was used as control) were made into the ARC of the hypothalamus. Oxygen consumption, carbon dioxide production, respiratory exchange ratio and energy expenditure were measured by using the CLAMS; Total, visceral and subcutaneous fat was analyzed using micro-CT. Co-immunoprecipitation assays (Co-IP) were used to analyze the interaction between MC4R and Kir2.1 in GT1-7 cells. RESULTS: POMC neuron-specific ablation of MC4R in the ARC region promoted food intake, impaired energy expenditure, leading to increased weight gain and impaired systemic glucose homeostasis. Additionally, MC4R ablation reduced the activation of POMC neuron, and is not tissue-specific for peripheral regulation, suggesting the importance of its central regulation. Mechanistically, sequencing analysis and Co-IP assay demonstrated a direct interaction of MC4R with Kir2.1. Knockdown of Kir2.1 in POMC neuron-specific ablation of MC4R restored the effect of MC4R ablation on energy expenditure and systemic glucose homeostasis, indicating by reduced body weight and ameliorated insulin resistance. CONCLUSION: Hypothalamic POMC neuron-specific knockout of MC4R affects energy balance and insulin sensitivity by regulating Kir2.1. Kir2.1 represents a new target and pathway that could be targeted in obesity.

SCARB2 associates with tumor-infiltrating neutrophils and predicts poor prognosis in breast cancer.

BACKGROUND: The tumor microenvironment (TME) plays a crucial role in various aspects of breast cancer development and metastasis. Nevertheless, the expression, prognostic significance, and correlation with clinical features of SCARB2 in breast cancer, as well as the infiltrative characteristics of TME, remain largely unknown. METHODS: We analyzed the differential presentation of SCARB2 mRNA in breast cancer tissues and nontumorous breast tissues and prognosis by The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) databases. Additionally, the Tumor Immunity Estimation Resource (TIMER) was taken to evaluate the correlation between SCARB2 mRNA presence and tumor-infiltrating immune cells and immune checkpoints in the TME in breast cancer. We performed multiple immunohistochemical staining to verify the SCARB2 protein expression in breast cancer tissues and its relationship to immune cells and checkpoints and clinicopathological features. RESULTS: We identified elevated SCARB2 expression in breast cancer tissues, and high SCARB2 protein presentation was associated with advanced clinical stage and unfavorable prognosis. In addition, enhanced SCARB2 protein presence was closely correlated with up-regulation CD66b+ neutrophils infiltration in tumor tissues (r = 0.210, P < 0.05) and CD68 + CD163+ M2 macrophages in the interstitium (r = 0.233, P < 0.05), as well as the immune checkpoints, including PD-1 (r = 0.314, P < 0.01) protein expression. CONCLUSION: SCARB2 holds promise for predicting the clinical outcome of breast cancer patients and could serve as a potential therapeutic target.

Dion-Jacobson Type Lead-Free Double Perovskite with Ultra-Narrow Aromatic Interlayer Spacing for Highly Sensitive and Stable X-ray Detection.

The low-toxic and environmentally friendly 2D lead-free perovskite has made significant progress in the exploration of "green" X-ray detectors. However, the gap in detection performance between them and their lead-based analogues remains a matter of concern that cannot be ignored. To reduce this gap, shortening the interlayer spacing to accelerate the migration and collection of X-ray carriers is a promising strategy. Herein, a Dion-Jacobson (DJ) lead-free double perovskite (4-AP)2AgBiBr8 (1, 4-AP = 4-amidinopyridine) with an ultra-narrow interlayer spacing of 3.0 Å, is constructed by utilizing π-conjugated aromatic spacers. Strikingly, the subsequent enhanced carrier transport and increased crystal density lead to X-ray detectors based on bulk single crystals of 1 with a high sensitivity of 1117.3 µC Gy-1 cm-2, superior to the vast majority of similar double perovskites. In particular, the tight connection of the inorganic layers by the divalent cations enhances structural rigidity and stability, further endowing 1 detector with ultralow dark current drift (3.06 × 10-8 nA cm-1 s-1 V-1, 80 V), excellent multiple cycles switching X-ray irradiation stability, as well as long-term environmental stability (maintains over 94% photoresponse after 90 days). This work brings lead-free double perovskites one step closer to realizing efficient practical green applications.

Clinical application of serum tumor abnormal protein in prostate cancer patients.

PURPOSE: To explore the clinical value of tumor abnormal protein (TAP) in the diagnosis and prognosis evaluation of prostate cancer. METHODS: This study enrolled a total of 265 patients who underwent prostate biopsy procedures from December 2017. TAP levels were assayed in their blood samples using a validated TAP testing kit. Comprehensive pathological assessments, including Gleason scores, TNM staging, and AJCC prognosis stages, were conducted on prostate cancer patients. Further analysis was carried out to examine the correlation between TAP expression levels and various clinical characteristics. RESULTS: A significantly elevated TAP concentration was discerned in prostate cancer patients relative to those with benign prostate hyperplasia. Moreover, a significantly elevated TAP expression was detected in prostate cancer patients with high Gleason score (≥ 8) and advanced stages (III and IV), as compared to those with Gleason scores of 6 and 7 and lower stages (I and II). When diagnosing prostate cancer in gray area of PSA, TAP demonstrated superior diagnostic capabilities over PSA alone, with higher diagnostic sensitivity, specificity and accuracy than fPSA/tPSA ratio. Additionally, post-surgical or hormonal treatment, there was a marked reduction in TAP expression level among prostate cancer patients. CONCLUSION: The assessment of TAP presents itself as a promising tool for early diagnosis and holds potential for sensitivity in monitoring treatment reponse in prostate cancer patients.

Red Fluorescent Molecule with Aggregation-Induced Emission Based on Dehydroabietic Acid Diarylamine for Bioimaging.

In this paper, molecules with AIE red light properties were designed by coupling dehydroabietic acid diarylamine and 2,3-diphenylfumaronitrile, which were designated 2DTPA-CN and 2TPA-CN. The emission wavelengths were 683 nm and 701 nm, respectively. The 2DTPA-CN and 2TPA-CN showed typical AIE characteristics with large Stokes shifts of 7.4 × 104 cm-1 and 6.7 × 104 cm-1, respectively. The obvious solvatochromism and electron cloud distributions of HOMO/LUMO in the ground and excited states both reveal the intramolecular charge transfer (ICT) effect. The 2DTPA-CN, boasting exceptional biocompatibility, was successfully prepared into nanoparticles (NPs), which were applied to tumor cell imaging, showing good bioimaging effects both in vitro imaging in live cells and in vivo imaging in live mice. The results demonstrated that it possesses significant potential as an effective bioimaging reagent for the detection of tumor cells. Furthermore, the incorporation of 2,3-diphenylfumaronitrile moieties to dehydroabietic acid diarylamine emerged as a proficient approach to broaden the emission wavelengths of rosin-based fluorescent materials.

Short-chain fatty acids: bridges between diet, gut microbiota, and health.

In recent years, gut microbiota has become a hot topic in the fields of medicine and life sciences. Short-chain fatty acids (SCFAs), the main metabolites of gut microbiota produced by microbial fermentation of dietary fiber, play a vital role in healthy and ill hosts. SCFAs regulate the process of metabolism, immune, and inflammation and have therapeutic effects on gastrointestinal and neurological disorders, as well as antitumor properties. This review summarized the production, distribution, and molecular mechanism of SCFAs, as well as their mechanisms of action in healthy and ill hosts. In addition, we also emphasized the negative effects of SCFAs, aiming to provide the public with a more comprehensive understanding of SCFAs.

Physical insight of random fluctuation in metal/IGZO Schottky barriers for low-variation contact optimal design.

The study aimed to investigate the impact of random fluctuations in Schottky barrier formation at polar interfaces between InGaZnO4 (IGZO) and different metals, particularly in the context of device miniaturization. The investigation revealed that different metals can establish various crystalline IGZO interfaces to achieve Ohmic contact, regardless of their work function. Additionally, the study suggests that introducing In doping at the amorphous IGZO interface can effectively reduce the Schottky barrier when in contact with Al metal. These findings provide theoretical guidance for the miniaturization of source-drain contacts in IGZO devices.

NXPH4 mediated by m5C contributes to the malignant characteristics of colorectal cancer via inhibiting HIF1A degradation.

OBJECTIVE: Colorectal cancer (CRC) is a form of malignancy that exhibits a comparatively elevated occurrence and fatality rate. Given the relatively slower progress in diagnostic and therapeutic approaches for CRC, there is a need to investigate more accurate and efficient biomarkers. METHODS: Core regulatory genes were screened using the TCGA database, and the expression of neurexophilin 4 (NXPH4) and its prognostic implications were validated using tissue microarray staining. The assessment of NXPH4 functions involved a range of experiments, including cellular, organoid, and murine models. Furthermore, a regulatory network between m5C, NXPH4, and HIF1A was established through several in vitro experiments. RESULTS: The overexpression of NXPH4 is associated with unfavorable prognoses in patients with CRC and hepatocellular carcinoma. Additionally, it facilitates the progression of malignant tumors both in laboratory settings and in living organisms of colorectal carcinoma. Our research also reveals that NXPH4 mRNA can avoid degradation through RNautophagy, relying on an m5C-dependent mechanism. Moreover, NXPH4 amplifies the HIF signaling pathway and stabilizes HIF1A by competitively binding to PHD4. CONCLUSIONS: NXPH4, regulated by m5C, promotes malignant tumor progression and regulates the HIF pathway. Consequently, targeting NXPH4 through molecular therapies could potentially serve as an efficacious therapeutic strategy for the management of CRC exhibiting elevated NXPH4 expression.

A noninvasive method for predicting clinically significant prostate cancer using magnetic resonance imaging combined with PRKY promoter methylation level: a machine learning study.

BACKGROUND: Traditional process for clinically significant prostate cancer (csPCA) diagnosis relies on invasive biopsy and may bring pain and complications. Radiomic features of magnetic resonance imaging MRI and methylation of the PRKY promoter were found to be associated with prostate cancer. METHODS: Fifty-four Patients who underwent prostate biopsy or photoselective vaporization of the prostate (PVP) from 2022 to 2023 were selected for this study, and their clinical data, blood samples and MRI images were obtained before the operation. Methylation level of two PRKY promoter sites, cg05618150 and cg05163709, were tested through bisulfite sequencing PCR (BSP). The PI-RADS score of each patient was estimated and the region of interest (ROI) was delineated by 2 experienced radiologists. After being extracted by a plug-in of 3D-slicer, radiomic features were selected through LASSCO regression and t-test. Selected radiomic features, methylation levels and clinical data were used for model construction through the random forest (RF) algorithm, and the predictive efficiency was analyzed by the area under the receiver operation characteristic (ROC) curve (AUC). RESULTS: Methylation level of the site, cg05618150, was observed to be associated with prostate cancer, for which the AUC was 0.74. The AUC of T2WI in csPCA prediction was 0.84, which was higher than that of the apparent diffusion coefficient ADC (AUC = 0.81). The model combined with T2WI and clinical data reached an AUC of 0.94. The AUC of the T2WI-clinic-methylation-combined model was 0.97, which was greater than that of the model combined with the PI-RADS score, clinical data and PRKY promoter methylation levels (AUC = 0.86). CONCLUSIONS: The model combining with radiomic features, clinical data and PRKY promoter methylation levels based on machine learning had high predictive efficiency in csPCA diagnosis.

Efficacy of sensory-based static balance training on the balance ability, aging attitude, and perceived stress of older adults in the community: a randomized controlled trial.

BACKGROUND: This study explores the effect of sensory-based static balance training on the balance ability, aging attitude, and perceived stress of older adults in the community. It provides a practical basis for the in-depth implementation and revision of the community health management model. METHODS: A randomized controlled intervention study was conducted from 2022 to 2023. A total of 72 older adults were recruited and randomly divided into an intervention group (36 individuals) and a control group (36 individuals). Balance ability (measured by the Short Physical Performance Battery and One Leg Stand Test), aging attitudes, and perceived stress were assessed at baseline and at the 12-week and 24-week follow-ups. Repeated-measures ANOVA and generalized estimating equations were used to compare outcome measures. RESULTS: Sensory-based static balance training was beneficial for balance ability and aging attitude among participants in the intervention group. At the end of the intervention, participants in the intervention group showed significant improvements in SPPB scores and OLST scores compared with the control group (FSPPB = 12.347, P = 0.001, Waldχ2OLST = 45.530, P < 0.001), as well as significant differences in aging attitudes (FAAQ = 18.549, P < 0.001). Multiple comparisons at different time points in the intervention group reveal a significant intervention effect (FSPPB = 29.211, Waldχ2OLST = 80.428, FAAQ = 45.981, all P < 0.05). However, the difference in perceived stress before and after the intervention was not significant (FCPSS = 2.876, P = 0.095). CONCLUSIONS: Sensory-based static balance training significantly improved balance ability and aging attitudes among older adults in the community. The effect on perceived stress among older adults in the community was not significant. TRIAL REGISTRATION: Registered in the Chinese Clinic on 04/06/2022. The registration number is ChiCTR2200060541.

Exploration of subgroups and predictors of loneliness among older adults in rural China: A latent profile analysis.

BACKGROUND: Loneliness is a negative emotional state that can lead to physical and mental health problems. This study's objective was to acquire an in-depth understanding of the heterogeneity and the predictors of loneliness among older adults in rural China and provide valuable references for practical interventions. METHODS: Older rural adults in China (N = 680) were recruited between January and April 2023. Latent profile analysis (LPA) was employed to identify subgroups of loneliness among participants. Single-factor and multinomial logistic regression analyses were conducted to investigate predictors of loneliness. RESULTS: The loneliness of rural older adults could be divided into three subgroups: low interaction loneliness group (55.0%), moderate emotional loneliness group (31.8%), and high loneliness group (13.2%). The subgroup predictors included age, gender, religious beliefs, marital status, living alone, number of chronic diseases, and smartphone use (P < 0.05). CONCLUSION: This study identified a classification pattern for loneliness among older adults in rural areas of China, revealed the characteristics of different demographic variables in loneliness categories, and highlighted the heterogeneity of loneliness in this population. It serves as a theoretical reference for formulating intervention plans aimed at addressing various loneliness categories for local rural older adults. CLINICAL TRIAL REGISTRATION: ChiCTR2300071591.

Voriconazole plus flucytosine is not superior to amphotericin B deoxycholate plus flucytosine as an induction regimen for cryptococcal meningitis treatment.

BACKGROUND: The efficacy and side effects of voriconazole plus 5-flucytosine (Vori + 5-FC) versus amphotericin B deoxycholate plus 5-flucytosine (AmBd + 5-FC) as an induction treatment for cryptococcal meningitis are unknown. METHODS: Forty-seven patients treated with Vori + 5-FC and 92 patients treated with AmBd + 5-FC were included in the current study after propensity score matching (PSM) at a ratio of 1:2. Two-week laboratory test results and 90-day mortality were compared between the two groups. RESULTS: After 2 weeks of induction treatment, the CSF Cryptococcus sterile culture rate was 57.1% in the Vori + 5-FC group and 76.5% in the AmBd + 5-FC group (p = .026). No difference was found in the normalization of CSF indicators (glucose, total protein, intracranial pressure and India ink sterile rate) between the two groups. Both the Vori + 5FC regimen and AmBd + 5-FC regimen obviously decreased haemoglobin concentrations, platelet counts and serum potassium levels (all p ≤ .010). Notably, the Vori + 5FC regimen did not influence serum creatinine levels (p = .263), while AmBd + 5FC increased serum creatinine levels (p = .019) after 2-week induction treatment. The Vori + 5-FC group and AmBd + 5-FC group had similar 90-day cumulative survival rates (89.9% vs. 87.8%, p = .926). CONCLUSION: The Vori + 5-FC regimen was associated with low 2-week CSF sterile culture and was not superior to AmBd + 5-FC as induction therapy in terms of the 90-day cumulative survival rate of CM patients.

Analysis of Risk Factors for Pulmonary Infections During Radiotherapy in Lung Cancer Patients.

Objective: To investigate the risk factors for lung infection in lung cancer patients undergoing radiotherapy. Methods: We selected 142 patients with lung cancer who underwent radiotherapy at our hospital from January 2020 to June 2021. The patients were divided into groups according to whether they had pulmonary infection during radiotherapy in our hospital, which was infected group (n=44) and the uninfected group (n=98), respectively. To observe the incidence of lung infection in lung cancer patients during radiotherapy. The distribution of pathogenic bacteria in patients with pulmonary infection was observed. Clinical data of the two groups were collected and compared. The risk factors of lung cancer patients complicated with lung infection were analyzed by binary Logistic regression. Results: All patients with lung cancer complicated with lung infection underwent relevant examination, and the results showed that they were all complicated infections, and the composition ratio of Klebsiella pneumoniae was the highest (31.82%), followed by Staphylococcus, Pseudomonas, and fungi, which accounted for 27.27%, 22.73%, and 18.18%, respectively. Binary Logistic regression analysis showed that age ≥60 years old, smoking history ≥30 years, radiotherapy duration of combined drug regimen > 2 weeks, pathogenic bacteria combined infection, albumin content < 30 g/L were risk factors for lung cancer patients during radiotherapy. Conclusion: Age ≥60 years old, smoking history ≥30 years old, radiotherapy duration of combined drug regimen > 2 weeks, pathogenic bacteria combined infection, albumin content < 30 g/L are the risk factors for lung cancer patients during radiotherapy. Clinical prevention and intervention should be based on the aforementioned independent risk factors to decrease the incidence of lung infections, thereby enhancing patient prognosis.

Direct Fabrication of Sub-10 nm Nanopores in WO3 Nanosheets Using Single Swift Heavy Ions.

Extending the fabrication methodology of solid-state nanopores in a wide range of materials is significant in the fields of single molecule detection, nanofluidic devices, and nanofiltration membranes. Here, we demonstrate a new method to directly fabricate size- and density-controllable sub-10 nm nanopores in WO3 nanosheets using single swift heavy ions (SHIs) without any chemical etching process. By selecting ions of different electronic energy losses (Se), nanopores with sizes from 1.8 to 7.4 nm can be created in WO3 nanosheets. The creation efficiency of nanopores achieves ∼100% for Se > 20 keV/nm, and there exists a critical thickness below which nanopores can be created. Combined with molecular dynamics simulations, we propose that the viscosity and surface tension of the transient molten phase caused by SHIs are the key factors for the formation of nanopores. This method paves a way to fabricate solid-state nanopores in materials with a low viscosity and surface tension.

The mediating role of self-directed learning ability in the impact of educational environment, learning motivation, and emotional intelligence on metacognitive awareness in nursing students.

PURPOSE: This study aimed to examine the mechanisms influencing metacognitive awareness among nursing students, encompassing educational environment, learning motivation, emotional intelligence, and self-directed learning ability. These findings could be a theoretical reference for formulating metacognitive awareness intervention strategies specifically designed for nursing students. METHOD: Through stratified sampling, 600 nursing students were recruited from two universities in China. Data collection involved five self-report instruments: the Metacognitive Awareness Inventory, Medical Education Environment Evaluation Scale, Learning Motivation Scale, Emotional Intelligence Scale, and Self-Directed Learning Ability Scale. Confirmatory factor analysis was utilized to test the measurement model, while structural equation modeling utilized multiple indices to assess model fit. Bootstrapping was conducted to analyze total, direct, and indirect effects. RESULTS: All study variables differed significantly according to age and year level (p < 0.01). Metacognitive awareness positively correlated with the educational environment, learning motivation, emotional intelligence, and self-directed learning ability ( r = 0.493-0.729; all p < 0.01). The test of the measurement model shows good reliability and validity. The model depicting factors influencing metacognitive awareness demonstrated a good fit (χ2/df = 2.42, SRMR = 0.048, RMSEA = 0.049, CFI = 0.947, IFI = 0.935). Path analyses revealed that educational environment (EE), learning motivation (LM), and emotional intelligence (EI) directly impacted self-directed learning ability (SDLA) ( ßEE = 0.189, ßLM = 0.436; ßEI = 0.215; all p < 0.05). Moreover, educational environment and self-directed learning ability directly influenced metacognitive awareness (ßEE = 0.224, ßSDLA = 0.520; all p < 0.05). Lastly, the educational environment, learning motivation, and emotional intelligence influenced metacognitive awareness by self-directed learning ability. CONCLUSION: Metacognitive awareness in nursing students rises with age and year level. Females exhibit more potent self-directed learning abilities than males. Educational environment, motivation, and emotional intelligence indirectly influence metacognitive awareness via self-directed learning ability. This finding has enriched the ways and perspectives of metacognitive awareness training for nursing students.

The MuvB complex safeguards embryonic stem cell identity through regulation of the cell cycle machinery.

Increasing evidences indicate that unlimited capacity for self-renewal and pluripotency, two unique properties of embryonic stem cells (ESCs), are intrinsically linked to cell cycle control. However, the precise mechanisms coordinating cell fate decisions and cell cycle regulation remain to be fully explored. Here, using CRISPR/Cas9-mediated genome editing, we show that in ESCs, deficiency of components of the cell cycle regulatory MuvB complex Lin54 or Lin52, but not Lin9 or Lin37, triggers G2/M arrest, loss of pluripotency, and spontaneous differentiation. Further dissection of these phenotypes demonstrated that this cell cycle arrest is accompanied by the gradual activation of mesoendodermal lineage-specifying genes. Strikingly, the abnormalities observed in Lin54-null ESCs were partially but significantly rescued by ectopic coexpression of genes encoding G2/M proteins Cyclin B1 and Cdk1. Thus, our study provides new insights into the mechanisms by which the MuvB complex determines cell fate through regulation of the cell cycle machinery.

Dual-Recognition Triggered Proximity Ligation Combined with a Rolling Circle Amplification Strategy for Analysis of Exosomal Protein-Specific Glycosylation.

Exosomal surface glycan reveals the biological function and molecular information on the protein, especially in indicating the pathogenesis of certain diseases through monitoring of specific protein glycosylation accurately. However, in situ and nondestructive measurement techniques for certain Exosomal glycoproteins are still lacking. In this work, combined with on-chip purification, we designed a proximity ligation assay-induced rolling circle amplification (RCA) strategy for highly sensitive identification of Exosomal protein-specific glycosylation based on a couple of proximity probes to target Exosomal protein and the protein-specific glycosylation site. Benefiting from efficient separation, scalable dual-recognition, and proximity-triggered RCA amplification, the proposed strategy could convert different protein-specific glycan levels to prominent changes in absorbance signals, resulting in accurate quantification of specific glycosylated Exosomal protein. When detecting the glycosylated PD-L1 on MDA-MB-231 exosomes and glycosylated PTK7 on HepG2 exosomes, the detection limits were calculated to be as low as 1.04 × 104 and 2.759 × 103 particles/mL, respectively. In addition, we further expand the dual-recognition site to investigate the potential correlation of Exosomal glycosylation with polarization of THP-1 cells toward the tumor-suppressive M1 phenotype. Overall, this strategy provides a universal tool for multiple analyses of diverse protein-specific glycosylated exosomes, exhibiting enormous potential to explore exosome function and search for new early diagnosis markers.

Dual Signal Amplification by Urease Catalysis and Silver Nanoparticles for Ultrasensitive Colorimetric Detection of Nucleic Acids.

Signal amplification techniques are highly desirable for the analysis of low-level targets that are closely related with diseases and the monitoring of important biological processes. However, it is still challenging to achieve this goal in a facile and economical way. Herein, we developed a novel dual signal amplification strategy by combining urease catalysis with the release of Ag+ from silver nanoparticles (AgNPs). This strategy was used for quantifying a DNA sequence (HIV-1) related with human immunodeficiency virus (HIV). DNA target HIV-1 hybridizes with the capture DNA probe on magnetic beads and the reporter DNA probe on AgNPs, forming a sandwich complex. The captured AgNPs are then transformed into numerous Ag+ ions that inactivate numerous ureases. Without catalytic production of ammonia from urea, the substrate solution shows a low pH 5.8 that will increase otherwise. The pH change is monitored by a pH indicator (phenol red), which allows for colorimetric detection. The proposed approach is sensitive, easy to use, economic, and universal, exhibiting a low detection limit of 9.7 fM (i.e., 1.94 attomoles) and a dynamic linear range of 4 orders for HIV-1 sequence detection.