SARS-CoV-2 Infection Induces Ferroptosis of Sinoatrial Node Pacemaker Cells.

BACKGROUND: Increasing evidence suggests that cardiac arrhythmias are frequent clinical features of coronavirus disease 2019 (COVID-19). Sinus node damage may lead to bradycardia. However, it is challenging to explore human sinoatrial node (SAN) pathophysiology due to difficulty in isolating and culturing human SAN cells. Embryonic stem cells (ESCs) can be a source to derive human SAN-like pacemaker cells for disease modeling. METHODS: We used both a hamster model and human ESC (hESC)-derived SAN-like pacemaker cells to explore the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on the pacemaker cells of the heart. In the hamster model, quantitative real-time polymerase chain reaction and immunostaining were used to detect viral RNA and protein, respectively. We then created a dual knock-in SHOX2:GFP;MYH6:mCherry hESC reporter line to establish a highly efficient strategy to derive functional human SAN-like pacemaker cells, which was further characterized by single-cell RNA sequencing. Following exposure to SARS-CoV-2, quantitative real-time polymerase chain reaction, immunostaining, and RNA sequencing were used to confirm infection and determine the host response of hESC-SAN-like pacemaker cells. Finally, a high content chemical screen was performed to identify drugs that can inhibit SARS-CoV-2 infection, and block SARS-CoV-2-induced ferroptosis. RESULTS: Viral RNA and spike protein were detected in SAN cells in the hearts of infected hamsters. We established an efficient strategy to derive from hESCs functional human SAN-like pacemaker cells, which express pacemaker markers and display SAN-like action potentials. Furthermore, SARS-CoV-2 infection causes dysfunction of human SAN-like pacemaker cells and induces ferroptosis. Two drug candidates, deferoxamine and imatinib, were identified from the high content screen, able to block SARS-CoV-2 infection and infection-associated ferroptosis. CONCLUSIONS: Using a hamster model, we showed that primary pacemaker cells in the heart can be infected by SARS-CoV-2. Infection of hESC-derived functional SAN-like pacemaker cells demonstrates ferroptosis as a potential mechanism for causing cardiac arrhythmias in patients with COVID-19. Finally, we identified candidate drugs that can protect the SAN cells from SARS-CoV-2 infection.

Precision Therapy of Recurrent Breast Cancer through Targeting Different Malignant Tumor Cells with a HER2/CD44-Targeted Hydrogel Nanobot.

Heterogeneity and drug resistance of tumor cells are the leading causes of incurability and poor survival for patients with recurrent breast cancer. In order to accurately deliver the biological anticancer drugs to different subtypes of malignant tumor cells for omnidirectional targeted treatment of recurrent breast cancer, a distinct design is demonstrated by embedding liposome-based nanocomplexes containing pro-apoptotic peptide and survivin siRNA drugs (LPR) into Herceptin/hyaluronic acid cross-linked nanohydrogels (Herceptin-HA) to fabricate a HER2/CD44-targeted hydrogel nanobot (named as ALPR). ALPR delivered cargoes to the cells overexpressing CD44 and HER2, followed by Herceptin-HA biodegradation, subsequently, the exposed lipid component containing DOPE fused with the endosomal membrane and released peptide and siRNA into the cytoplasm. These experiments indicated that ALPR can specifically deliver Herceptin, peptide, and siRNA drugs to HER2-positive SKBR-3, triple-negative MDA-MB-231, and HER2-negative drug-resistant MCF-7 human breast cancer cells. ALPR completely inhibited the growth of heterogeneous breast tumors via multichannel synergistic effects: disrupting mitochondria, downregulating the survivin gene, and blocking HER2 receptors on the surface of HER2-positive cells. The present design overcomes the chemical drug resistance and opens a feasible route for the combinative treatment of recurrent breast cancer, even other solid tumors, utilizing different kinds of biological drugs.

Osteopontin is required for the maintenance of leukemia stem cells in acute myeloid leukemia.

Acute myeloid leukemia (AML) is a heterogeneous hematopoietic disorder with a poor prognosis. The clinical significance of Leukemia stem cells (LSCs) plays an important role in the generation of AML and is the main cause of the recurrence after remission. Osteopontin (OPN), an extracellular matrix protein, has been implicated in hematopoietic malignancies. However, the specific role and the underlying mechanism of AML cell autocrined OPN in leukemia maintenance remain unknown. Here, we showed that knockdown of Opn expression significantly prolonged the survival of mice with MLL-AF9 cell-induced AML and markedly reduced the tumor burden. The LSCs from the Opn-knockdown groups exhibited decreased numbers and impaired function as determined by immunophenotype, colony-forming and limiting dilution assays. Further analysis revealed that Opn prevents LSCs from undergoing apoptosis and cell cycle arrest. Repression of OPN in human AML cell lines in vitro mimics the phenotypes observed in the mouse model. Overall, our data indicated that OPN is a potent therapeutic target for eradicating LSCs in AML.

Identification of heart failure with preserved ejection fraction helps risk stratification for hypertrophic cardiomyopathy.

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) is the dominant form of heart failure (HF). We here aimed to investigate the characteristics and prognosis of HFpEF in patients with hypertrophic cardiomyopathy (HCM). METHODS: This was a prospective cohort study and patients with HCM with available NT-proBNP results were enrolled. Patients were categorized into HFpEF [defined as LVEF ≥50%, with symptoms or signs of HF, and N-terminal pro-brain natriuretic peptide ≥800 pg/mL according to American Heart Association (AHA) criteria] and without heart failure (non-HF). The outcomes of interest were all-cause death, cardiovascular death, and sudden cardiac death (SCD). RESULTS: Of 1178 included patients with HCM, 513 (43.5%) were identified as having HFpEF according to AHA criteria. Compared with non-HF patients, patients with HFpEF had significantly larger maximal wall thickness (P < 0.001), higher maximal left ventricular outflow tract gradient (P < 0.001), higher proportion of atrial fibrillation (P < 0.001), higher incidence of all-cause death (log-rank test, P = 0.002), and cardiovascular death (log-rank test, P = 0.005). Multivariable Cox analysis showed that patients with HFpEF had a nearly two-fold higher risk of all-cause death (adjusted HR = 1.80, 95% CI 1.11-2.90; P = 0.017) and cardiovascular death (adjusted HR =1.82, 95% CI 1.05-3.18; P = 0.033) than non-HF patients. CONCLUSIONS: Patients with HCM have a high prevalence of HFpEF and those with HFpEF present greater disease severity and higher mortality than non-HF patients, and thus may require an appropriate and more aggressive treatment for HF management. Identification of patients with HFpEF using AHA criteria can provide guidance on patient risk stratification for patients with HCM.

Impact of different axial wall designs on the fracture strength and stress distribution of ceramic restorations in mandibular first molar.

BACKGROUND: The purpose of this study was to investigate the fracture strength and stress distribution of four ceramic restorations. METHODS: Forty human mandibular first molars were collected and randomized into four groups after establishing the distal defect: full crown group with 4 mm axial wall height (AWH) (FC4); short AWH crown group with 2 mm AWH (SC2); occlusal veneer group with 0 mm AWH (OV0); occlusal distal veneer group with only the distal surface prepared, and 4 mm AWH (OD4). The teeth were prepared according to the groups and the ceramic restorations were completed using celtra duo ceramic blocks. The ceramic thickness of the occlusal surface is about 1.5 mm and the edge is about 1 mm. The failure load values and fracture modes of each group were detected by mechanical test in vitro. According to the groups to establish three-dimensional finite element analysis (FEA) models, a 600 N loading force was applied vertically using a hemispherical indenter with a diameter of 6 mm. and compare the stress distribution under the condition of different restorations. RESULTS: In vitro mechanical tests showed that the failure load values were SC2 (3232.80 ± 708.12 N) > OD4 (2886.90 ± 338.72 N) > VO0 (2133.20 ± 376.15 N) > FC4(1635.40 ± 413.05 N). The failure load values of the short AWH crown and occlusal distal veneer were significantly higher than that of occlusal veneer and full crown (P<0.05). The fracture modes of the full crown and occlusal veneer groups were mainly ceramic fractures and some were restorable tooth fractures. The short AWH crown and occlusal distal veneer groups presented with three fracture modes, the proportion of non-restorable tooth fracture was higher. The results of FEA show that under the spherical loading condition, the stress of ceramic was concentrated in the contact area of the loading head, the maximum von Mises stress values were FC4 (356.2 MPa) > VO0 (214.3 MPa) > OD4 (197.9 MPa) > SC2 (163.1 MPa). The stress of enamel was concentrated in the area where the remaining enamel was thinner, the maximum von Mises stress values was OD4 (246.2 MPa) ≈ FC4 (212.4 MPa) > VO0 (61.8 MPa) ≈ SC2 (45.81 MPa). The stress of dentin is concentrated in the root furcation and the upper third region of the root. However, stress concentration was observed at the tooth cervix in the full crown. CONCLUSION: Under certain conditions, the occlusal distal veneer shows better performance than the full crown.

A preliminary study on the role of Bacteroides fragilis in stent encrustation.

OBJECTIVE: To preliminarily study the characteristics of bacterial flora distribution in the urine of ureteral stent encrustation patients as well as the relation between Bacteroides and stent encrustation. METHODS: Patients undergoing ureteral stenting were included in the study and divided into encrustation group and non-encrustation group based on the condition of stent encrustation. The urine of patients was collected to undergo 16s DNA test to compare the bacterial flora distribution characteristics of the two groups. The bacterial genus with highest abundance in the urine of encrustation group was used for animal experiment. A rat model with a foreign body in the bladder was created, in which the rats were injected with the aforesaid bacterial genus. A control group injected with normal saline was also formed. The incidence of foreign body tube encrustation between the two groups was compared. RESULTS: The urine collected from the patients in encrustation group contained a variety of bacteria, while dominant bacteria genera included g_Lactobacillus (23.1%), g_Bacteroides (18.8%) and g_norank_Bacteroides (17.1%). While the urine from the non-encrustation group was less diverse in bacteria flora, as the major bacteria genera were g_Escherichia-Shigella (32.2%), g_Enterococcus (24.9%) and g_Pseudomonas (18.2%). Bacteroidetes in the encrustation group were significantly higher, therefore Bacteroides fragilis in this genus was adopted for animal experiment, resulting in a higher incidence of foreign body tube encrustation in the bladder among rats. CONCLUSION: The present study enriches our knowledge about ureteral stent encrustation and reveals that the target regulation of urine bacteria is worth further research and clinical application.

Interleukin-1ß inhibits normal hematopoietic expansion and promotes acute myeloid leukemia progression via the bone marrow niche.

Enhanced interleukin-1ß (IL-1ß) signaling is a common event in patients with acute myeloid leukemia (AML). It was previously demonstrated that chronic IL-1ß exposure severely impaired hematopoietic stem cell (HSC) self-renewal capability in mice and promoted leukemia cell growth in primary AML cells. However, the role of IL-1ß in the murine bone marrow (BM) niche remains unclear. Here, we explored the role of IL-1ß in the BM niche in Il-1r1-/- mice, chronic IL-1ß exposure mice and mixed lineage leukemia-AF9 fusion gene (MLL-AF9)-induced AML mice models. We demonstrated that IL-1R1 deficiency did not affect the function of HSCs or niche cells under steady-state conditions or during transplantation. Chronic exposure to IL-1ß decreased the expansion of Il-1r1-/- hematopoietic cells in Il-1r1+/+ recipient mice. These results indicated that IL-1ß exposure impaired the ability of niche cells to support hematopoietic cells. Furthermore, we revealed that IL-1R1 deficiency in niche cells prolonged the survival of MLL-AF9-induced AML mice. The results of our study suggest that inhibition of the IL-1ß/IL-1R1 signaling pathway in the niche might be a non-cell-autonomous therapy strategy for AML.

Knockout of the X-linked Fgf13 in the hypothalamic paraventricular nucleus impairs sympathetic output to brown fat and causes obesity.

Fibroblast growth factor (FGF)13, a nonsecreted, X-linked, FGF homologous factor, is differentially expressed in adipocytes in response to diet, yet Fgf13's role in metabolism has not been explored. Heterozygous Fgf13 knockouts fed normal chow and housed at 22°C showed hyperactivity accompanying reduced core temperature and obesity when housed at 30°C. Those heterozygous knockouts showed defects in thermogenesis even at 30°C and an inability to protect core temperature. Surprisingly, we detected trivial FGF13 in adipose of wild-type mice fed normal chow and no obesity in adipose-specific heterozygous knockouts housed at 30°C, and we detected an intact brown fat response through exogenous ß3 agonist stimulation, suggesting a defect in sympathetic drive to brown adipose tissue. In contrast, hypothalamic-specific ablation of Fgf13 recapitulated weight gain at 30°C. Norepinephrine turnover in brown fat was reduced at both housing temperatures. Thus, our data suggest that impaired CNS regulation of sympathetic activation of brown fat underlies obesity and thermogenesis in Fgf13 heterozygous knockouts fed normal chow.-Sinden, D. S., Holman, C. D., Bare, C. J., Sun, X., Gade, A. R., Cohen, D. E., Pitt, G. S. Knockout of the X-linked Fgf13 in the hypothalamic paraventricular nucleus impairs sympathetic output to brown fat and causes obesity.

MiR-381-3p/RAB2A axis activates cell proliferation and inhibits cell apoptosis in bladder cancer.

Acting as a really common cancer in the world, bladder cancer has taken many people's life away. MiRNAs and mRNA have been reported can regulate the expression of cancers. In this study, the role of RAB2A and miR-381-3p was fully studied in bladder cancer. qRT-PCR assay probe the expression of RAB2A and miR-381-3p in bladder cancer cells. Meanwhile, colony formation assay, EdU assay, flow cytometry analysis, JC-1 assay and western blot assay were implemented to detect the progression of bladder cancer cells. Silenced RAB2A could reduce the cell proliferation of bladder cancer, and activate the apoptosis. Meanwhile, miR-381-3p could bind to RAB2A in bladder cancer cells and overexpressed miR-381-3p could inhibit the progression of bladder cancer cells. MiR-381-3p/RAB2A axis activates cell proliferation and inhibits cell apoptosis in bladder cancer.

Electrospinning fabrication for cloth-like carbon nanofiber films with hierarchical porous structure and their application in deep desulfurization.

A strategy for clean fuel by selective adsorption processing was deemed to be convenient and environmental-friendly in past decades. However, the development of adsorption desulfurization was tremendously subject to the fabrication of high-performance adsorbents with large capacity and high stability. Herein, we designed a novel route to fabricate the cloth-like carbon nanofiber film with a hierarchical porous structure by electrospinning. The structure and properties of the cloth-like carbon nanofiber films were determined by a series of characterizations. Subsequently, the desulfurization performance of the cloth-like carbon nanofiber films was examined by the simulated thiophene (TH) oil. Furthermore, the effect of adsorption conditions on the adsorption capacity was intensively investigated, such as carbonization temperature, initial concentration and desulfurization temperature. The results found that at optimal calcination temperature of 700 °C, the cloth-like carbon nanofiber films possessed the highest micropore volume (Vmic = 0.185 m3/g) and adsorption capacity (qe = 96.6 mg/g) at 800 mg/L initial concentration under the adsorption temperature of 25 °C. The results corroborated that the physical properties of the cloth-like carbon nanofiber films with the surface area of 417.8 m2/g, the total pore volume of 0.187 cm3/g and average pore diameter of 1.36 nm had an important influence on the high adsorption capacity. On this basis, the adsorption experimental data were best fitted to pseudo-second-order kinetic and Langmuir isotherm models. Furthermore, the other highlight of the cloth-like carbon nanofiber films was convenient for the separation from oil, thus achieving the desirable reused performance.

Adsorption of Pb2+ onto freeze-dried microalgae and environmental risk assessment.

Dry microalgae Spirulina platensis shows a high capacity for heavy metal uptake, but there is a concern about dissolved organic carbon (DOC) residue, which is the precursor of disinfection by-products (DBPs). Vsp, a kind of Spirulina platensis powder prepared by vacuum freeze-drying, and Osp, a kind of Spirulina platensis powder prepared by the conventional oven drying-pulverization method, were subjected to assessments of their adsorption potential for Pb2+ and DOC residue. The adsorption mechanism of Pb2+ by the two adsorbents was studied by SEM, FT-IR, EDX and N2-BET. The effects of pH, adsorbent dosage, initial Pb2+ concentration and contact time on the biosorption process were investigated. The results showed that Pb2+ biosorption by Vsp and Osp were fit well by a pseudo-second-order kinetic model and the Langmuir model. The maximum amount of Pb2+ biosorption by Vsp was 253 mg/g, which was 33 mg/g greater than that of Osp. In comparison with Osp, Vsp reached adsorption saturation 8 h earlier and had a remarkable effect on the control of DOC residue in water. When both adsorption capacity and environmental risks were considered, it was determined that the dosage of 0.5 g/L Vsp for 2 h of contact time was the best method, with 85.89 mg/g of Pb2+ removal and 3.45 mg/L of DOC residue. In summary, Vsp is a highly efficient and environmentally friendly biosorbent that can be used for heavy metal removal from water.

Human umbilical cord mesenchymal stem cells derived exosomes exert antiapoptosis effect via activating PI3K/Akt/mTOR pathway on H9C2 cells.

BACKGROUND/OBJECTIVES: In recent years, as an alternative to stem cell therapy for cardiovascular diseases (CVD), exsomes have attracted wide attention among researchers. The present study aimed to investigate the role of human umbilical cord mesenchymal stem cells (UC-MSCs) derived exosomes play on H9C2 cells apoptosis and possible mechanisms. METHODS: Exosomes were isolated from normal UC-MSCs culture media and hypoxic preconditioning culture media. Transmission electron microscopy was used to observe the morphology of exosomes. Nanoparticle tracking analysis was used to detect the size distribution and concentration of exosomes. Western blot analysis was used to analyzed the surface marker CD63 of exosomes. H9C2 cells were induced apoptosis by hypoxia and serum deprivation (H/SD) and then were treated respectively by group. Cell Counting Kit-8 assay was used to detect viability of H9C2 cells. Apoptosis was detected by Hochest staining and annexin V-FITC/PI. The expression levels of related proteins of apoptosis, autophagy, and PI3K/Akt/mTOR pathway were analyzed by Western blot analysis. Immunofluorescence was used to analyze LC3B expression. RESULTS: Hypoxic preconditioning increased the exosomes secretion of UC-MSCs. UC-MSCs derived exosomes could inhibit H/SD-induced H9C2 cells apoptosis. Hypoxic preconditioning strengthened this antiapoptosis effect of UC-MSCs. Hypoxic preconditioning UC-MSCs derived exosomes (H-Exo) downregulated LC3B-II/I and beclin-1 and upregulated P62, p-Akt/Akt and p-mTOR/mTOR. The antiapoptotic effect of H-Exo could be attenuated by treatment with LY294002 and rapamycin. CONCLUSION: UC-MSCs derived exosomes could inhibit H9C2 cells apoptosis induced by H/SD through regulating autophagy via PI3K/Akt/mTOR pathway. Hypoxia preconditioning could enhance above effects through increasing exosomes secretion of UC-MSCs.

Mitochondrial but not plasmalemmal BK channels are hypoxia-sensitive in human glioma.

Tumor cells are resistant to hypoxia but the underlying mechanism(s) of this tolerance remain poorly understood. In healthy brain cells, plasmalemmal Ca(2+)-activated K(+) channels ((plasma)BK) function as oxygen sensors and close under hypoxic conditions. Similarly, BK channels in the mitochondrial inner membrane ((mito)BK) are also hypoxia sensitive and regulate reactive oxygen species production and also permeability transition pore formation. Both channel populations are therefore well situated to mediate cellular responses to hypoxia. In tumors, BK channel expression increases with malignancy, suggesting these channels contribute to tumor growth; therefore, we hypothesized that the sensitivity of (plasma)BK and/or (mito)BK to hypoxia differs between glioma and healthy brain cells. To test this, we examined the electrophysiological properties of (plasma)BK and (mito)BK from a human glioma cell line during normoxia and hypoxia. We observed single channel activities in whole cells and isolated mitoplasts with slope conductance of 199 ± 8 and 278 ± 10 pA, respectively. These currents were Ca(2+)- and voltage-dependent, and were inhibited by the BK channel antagonist charybdotoxin (0.1 µM). (plasma)BK could only be activated at membrane potentials >+40 mV and had a low open probability (NPo) that was unchanged by hypoxia. Conversely, (mito)BK were active across a range of membrane potentials (-40 to +40 mV) and their NPo increased during hypoxia. Activating (plasma)BK, but not (mito)BK induced cell death and this effect was enhanced during hypoxia. We conclude that unlike in healthy brain cells, glioma (mito)BK channels, but not (plasma)BK channels are oxygen sensitive.

Effect of postoperative intermittent boluses of subcostal quadratus lumborum block on pulmonary function recovery and analgesia after gastrectomy: a randomized controlled clinical trial.

BACKGROUND: Following the gastrectomy, the reduction in pulmonary function is partly attributed to postoperative pain. Subcostal quadratus lumborum block (QLB) has recently emerged as a promising component in multimodal analgesia. We aimed to assess the impact of intermittent boluses of subcostal QLB on pulmonary function recovery and analgesic efficacy after gastrectomy. METHODS: Sixty patients scheduled for gastrectomy were randomly assigned to either control group (multimodal analgesia) or intervention group (intermittent boluses of subcostal QLB plus multimodal analgesia). Two primary outcomes included the preservation of forced expiratory volume in the first second (FEV1) and the pain scores (0-10 cm visual analog score) on coughing 24 h postoperatively. We assessed the pulmonary function parameters, pain score, morphine consumption and number of rescue analgesia at a 24-h interval up to 72 h (Day1, Day2, Day3 respectively) as secondary outcomes. RESULTS: 59 patients were analyzed in a modified intention-to-treat set. The preservation of FEV1 (median difference: 4.0%, 97.5% CI: -5.7 to 14.9, P = 0.332) and pain scores on coughing (mean difference: 0.0 cm, 97.5% CI: -1.1 to 1.2, P = 0.924) did not differ significantly between two groups. In the intervention group, the recovery of forced vital capacity (FVC) was faster 72 h after surgery (interaction effect of group*(Day3-Day0): estimated effect (ß) =0.30 L, standard error (SE) =0.13, P = 0.025), pain scores at rest were lower in the first 3 days (interaction effect of group*(Day1-Day0): ß = - 0.8 cm, SE = 0.4, P = 0.035; interaction effect of group*(Day2-Day0): ß = - 1.0 cm, SE = 0.4, P = 0.014; and interaction effect of group*(Day3-Day0): ß = - 1.0 cm, SE = 0.4, P values = 0.009 respectively), intravenous morphine consumption was lower during 0-24 h (median difference: -3 mg, 95% CI -6 to -1, P = 0.014) and in total 72 h (median difference: -5 mg, 95% CI -10 to -1, P = 0.019), and the numbers of rescue analgesia was fewer during 24-48 h (median difference: 0, 95% CI 0 to 0, P = 0.043). Other outcomes didn't show statistical differences. CONCLUSION: Postoperative intermittent boluses of subcostal QLB did not confer advantages in terms of the preservation of FEV1 or pain scores on coughing 24 h after gastrectomy. However, notable effects were observed in analgesia at rest and FVC recovery.

Direct determination of high-concentration As(III) by UV high-reference differential absorption spectroscopy for cleaner As(III) removal promotion via sulfurization.

The current methods for determining high-concentration As(III) in the high-acid matrix from the copper smelting industry are complex, time-consuming, and costly. This limits effective modulation of sulfurizing agent dosage for As(III) removal via sulfurization, aggravating hazardous waste generation. Herein, a simple, rapid, and nondestructive UV high-reference differential absorption spectroscopy was developed to directly determine high-concentration As(III) in simulated high-acid wastewater. Time-dependent density functional theory calculations indicated that the spectral curve redshift with As(III) concentration increasing was related to the decrease of electron transition energies and energy gaps. When using high-reference solutions, the least redshift in the maximum absorption wavelength and the highest upper limit of linear fitting concentration could be obtained. Therefore, the piecewise quantitative linear model of differential absorbance and concentration was established under high-reference. The quantitative range of the model within 0.06-20.00 g/L As(III) with a mean relative error of < 5.0 % and standard recovery rates within 98.0 %-104.0 % indicated high accuracy. Additionally, the relative standard deviations of < 1.5 % (n = 5) revealed good precision. All results indicated the high feasibility of the developed method in alleviating linear deviation caused by redshift and absorption saturation. Furthermore, it has potential significance in saving sulfurizing agent dosage and reducing hazardous waste generation from the source, thereby facilitating a cleaner process for removing As(III) via sulfurization.

A pH-responsive cetuximab-conjugated DMAKO-20 nano-delivery system for overcoming K-ras mutations and drug resistance in colorectal carcinoma.

Cetuximab (Cet) and oxaliplatin (OXA) are used as first-line drugs for patients with colorectal carcinoma (CRC). In fact, the heterogeneity of CRC, mainly caused by K-ras mutations and drug resistance, undermines the effectiveness of drugs. Recently, a hydrophobic prodrug, (1E,4E)-6-((S)-1-(isopentyloxy)-4-methylpent-3-en-1-yl)-5,8-dimethoxynaphthalene-1,4­dione dioxime (DMAKO-20), has been shown to undergo tumor-specific CYP1B1-catalyzed bioactivation. This process results in the production of nitric oxide and active naphthoquinone mono-oximes, which exhibit specific antitumor activity against drug-resistant CRC. In this study, a Cet-conjugated bioresponsive DMAKO-20/PCL-PEOz-targeted nanocodelivery system (DMAKO@PCL-PEOz-Cet) was constructed to address the issue of DMAKO-20 dissolution and achieve multitargeted delivery of the cargoes to different subtypes of CRC cells to overcome K-ras mutations and drug resistance in CRC. The experimental results demonstrated that DMAKO@PCL-PEOz-Cet efficiently delivered DMAKO-20 to both K-ras mutant and wild-type CRC cells by targeting the epidermal growth factor receptor (EGFR). It exhibited a higher anticancer effect than OXA in K-ras mutant cells and drug-resistant cells. Additionally, it was observed that DMAKO@PCL-PEOz-Cet reduced the expression of glutathione peroxidase 4 (GPX4) in CRC cells and significantly inhibited the growth of heterogeneous HCT-116 subcutaneous tumors and patient-derived tumor xenografts (PDX) model tumors. This work provides a new strategy for the development of safe and effective approaches for treating CRC. STATEMENT OF SIGNIFICANCE: (1) Significance: This work reports a new approach for the treatment of colorectal carcinoma (CRC) using the bioresponsible Cet-conjugated PCL-PEOz/DMAKO-20 nanodelivery system (DMAKO@PCL-PEOz-Cet) prepared with Cet and PCL-PEOz for the targeted transfer of DMAKO-20, which is an anticancer multitarget drug that can even prevent drug resistance, to wild-type and K-ras mutant CRC cells. DMAKO@PCL-PEOz-Cet, in the form of nanocrystal micelles, maintained stability in peripheral blood and efficiently transported DMAKO-20 to various subtypes of colorectal carcinoma cells, overcoming the challenges posed by K-ras mutations and drug resistance. The system's secure and effective delivery capabilities have also been confirmed in organoid and PDX models. (2) This is the first report demonstrating that this approach simultaneously overcomes the K-ras mutation and drug resistance of CRC.

Loss of RNA-binding protein CELF2 promotes acute leukemia development via FAT10-mTORC1.

RNA-binding proteins (RBPs) are critical regulators for RNA transcription and translation. As a key member of RBPs, ELAV-like family protein 2 (CELF2) has been shown to regulate RNA splicing and embryonic hematopoietic development and was frequently seen dysregulated in acute myeloid leukemia (AML). However, the functional role(s) of CELF2 in hematopoiesis and leukemogenesis has not been fully elucidated. In the current study, we showed that Celf2 deficiency in hematopoietic system led to enhanced HSCs self-renewal and differentiation toward myeloid cells in mice. Loss of Celf2 accelerated myeloid cell transformation and AML development in MLL-AF9-induced AML murine models. Gene expression profiling integrated with RNA immunoprecipitation sequencing (RIP-Seq), together with biochemical experiments revealed that CELF2 deficiency stabilizes FAT10 mRNA, promotes FAT10 translation, thereby increases AKT phosphorylation and mTORC1 signaling pathway activation. Notably, combination therapy with a mTORC1 inhibitor (Rapamycin) and a MA9/DOTL1 inhibitor (EPZ-5676) reduced the leukemia burden in MLL-AF9 mice lacking Celf2 in vivo. Our study elucidated a novel mechanism by which the CELF2/FAT10-AKT/mTORC1 axis regulates the proliferation of normal blood cells and the development of AML, thus providing potential therapeutic targets for myeloid leukemia suppression.

[Clinical characteristics of 22 cases of fungal infective endocarditis].

OBJECTIVE: To explore the clinical characteristics, treatment regimens and outcomes of the patients with fungal infective endocarditis. METHODS: An observational study was conducted at our hospital and recruited 22 consecutive patients with a definite diagnosis of fungal infective endocarditis. Their overall characteristics, treatments, complications and outcomes were analyzed. RESULTS: The mean age at presentation was 45 years with a slight male preponderance. Among them, 13 cases had healthcare-associated infective endocarditis and 1 patient was an intravenous drug user. Aortic valve (40.9%) was most commonly affected and it was followed by mitral valve (13.6%). The most common etiological agent was Candida (68.2%), followed by Aspergillus (22.7%). Risk factors include the prosthetic valve replacement surgery, impaired immune function, and so on. Major complications during the acute infective phase were also recorded, including heart failure, embolic events, uncontrolled infections and renal dysfunction. The overall hospital mortality rate was 40.9%. There were 15 patients with antifungal treatment, which including fluconazole, itraconazole, caspofungin acetate and voriconazole itraconazole. The remaining 7 patients (31.8%) underwent valve replacement surgery, including 3 cases of cardiac valve re-replacement. A better outcome was observed in patients on a combined regimen of medical and surgical therapies. CONCLUSIONS: Fungal endocarditis is associated with more invasive interventions and immunocompromised patients. The incidence of embolic events and in-hospital mortality is still high in patients with fungal endocarditis, and the larger vegetation is more common. Heart failure, sepsis and repeated arterial embolization are the most common cause of death.

A portable microfluidic device integrated with electrochemical sensing platform for detection of multiple binders in ancient wall paintings.

The aging of the proteinaceous binders will cause the cultural relics to suffer from diseases such as flaking, cracks, and even peeling. Identifying the type of binders in a timely manner is conducive to restore diseased cultural relics. High-throughput and portable detection system are of great significance for researching cultural relic materials on the archaeological site. Therefore, in this work, a portable electrochemical microfluidic device for the simultaneous detection of casein, ovalbumin, and peach gum binders was developed. The proposed electrochemical immunosensor technology integrated with microfluidic device achieve the goals of miniaturization, portability and reagent-saving. For casein, ovalbumin and peach gum, excellent performance was obtained in terms of their limits of detection (LOD) at 0.237, 0.507, and 0.403 ng mL-1 (S/N = 3), respectively. In addition, the microfluidic sensing platform exhibited acceptable anti-interference ability, stability, and storage capacity. In order to evaluate the practical application value, the proposed microfluidic sensing device was applied for detecting eight archaeological samples from different historic sites. This work demonstrates great potential for high-throughput, portable detection of cultural relic proteinaceous binder materials.

FTO promotes proliferation and migration of bladder cancer via enhancing stability of STAT3 mRNA in an m6A-dependent manner.

N6-Methyladenosine (m6A) plays a key role in the occurrence and development of various cancers. Fat mass and obesity-associated protein (FTO) was is involved in multiple cancers owing to its demethylase activity, and the molecular mechanism underlying FTO-promoted bladder cancer proliferation and migration via the regulation of RNA stability requires further investigation. In the present study, FTO was upregulated in bladder cancer and related to poor prognosis. Gain- and loss-of-function experiments showed that the upregulation of FTO promoted bladder cancer proliferation and migration. Mechanistic studies showed that FTO enhanced the stability of signal transducer and activator of transcription 3 (STAT3) mRNA in an m6A-dependent manner, thereby increasing STAT3 expression, which subsequently promoted P-STAT3 expression and activated STAT3 signalling pathway. Overall, this study revealed that the critical role of FTO in the progression of bladder cancer and could provide a novel avenue to regulate oncogene STAT3.