Total bone mineral density is inversely associated with stroke: a family osteoporosis cohort study in rural China

BACKGROUND

The relationship of osteoporosis and stroke is still not fully clarified. Apart from the well-known risk factors for stroke, bone mineral density (BMD) has gained more interest in recent years.

AIM

To further elucidate the relationship between BMD and stroke risk, a prospective cohort study in the Chinese rural population was conducted.

DESIGN

Retrospective analysis of a family osteoporosis cohort.

METHODS

Our subjects were selected from an osteoporosis cohort conducted in Anqing, China. All participants underwent a questionnaire assessment, clinical examinations and laboratory assessments. During the follow-up period, the number of people who had a stroke was recorded. Generalized estimating equation regression analysis was performed to determine the significance of the association between BMD and stroke.

RESULTS

A total of 17868 people were included. A two-way interaction test of sex and BMD on stroke was significant (P = 0.002). There was a significant difference in BMD and stroke morbidity in the male group (P = 0.003). When BMD was assessed as quartiles and the lowest quartile was used as reference, a significantly lower risk for stroke was observed in Q2-4. Notably, no significant difference was observed in female participants with adjusted odds ratio (P > 0.05). The P-value for interaction was calculated. The body mass index (P = 0.014) and waist-to-hip ratio (P = 0.027) were found to be significantly associated with BMD and stroke risk in female participants.

CONCLUSIONS

In Chinese rural areas, total BMD may negatively correlated with stroke, especially in men.

Hinokiflavone induces apoptosis, cell cycle arrest and autophagy in chronic myeloid leukemia cells through MAPK/NF-κB signaling pathway

Background

Chronic myeloid leukemia (CML) is a myeloproliferative tumor originating from hematopoietic stem cells, and resistance to tyrosine kinase inhibitors (TKI) has become a major cause of treatment failure. Alternative drug therapy is one of the important ways to overcome TKI resistance. Hinokiflavone (HF) is a C-O-C type biflavonoid with low toxicity and antitumor activity. This study investigated the antitumor effect and possible mechanisms of HF in CML cells.

Methods

Cell viability was measured by CCK-8 assay. Cell apoptosis and cell cycle distribution were analyzed by flow cytometry. Western blotting was used to assess protein expression levels.

Results

Our results showed that HF significantly inhibited the viability of K562 cells in a concentration- and time-dependent manner and induced G₂/M phase arrest by up-regulating p21 and down-regulating Cdc2 protein. Furthermore, HF induced caspase-dependent apoptosis by activating JNK/p38 MAPK signaling pathway and inhibiting NF-κB activity. In addition, HF induced autophagy by increasing LC3-II expression and p62 degradation. Pretreatment with CQ, a late autophagy inhibitor, significantly increased the levels of LC3-II and p62 proteins and promoted cell survival.

Conclusion

HF shows a good anti-leukemia effect and is expected to become a potential therapeutic drug for CML.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03580-7.

CYP2C8, CYP2C9, and CYP2C19 Characterization Using Next-Generation Sequencing and Haplotype Analysis: A GeT-RM Collaborative Project

Pharmacogenetic tests typically target selected sequence variants to identify haplotypes that are often defined by star (∗) allele nomenclature. Due to their design, these targeted genotyping assays are unable to detect novel variants that may change the function of the gene product and thereby affect phenotype prediction and patient care. In the current study, 137 DNA samples that were previously characterized by the Genetic Testing Reference Material (GeT-RM) program using a variety of targeted genotyping methods were recharacterized using targeted and whole genome sequencing analysis. Sequence data were analyzed using three genotype calling tools to identify star allele diplotypes for CYP2C8, CYP2C9, and CYP2C19. The genotype calls from next-generation sequencing (NGS) correlated well to those previously reported, except when novel alleles were present in a sample. Six novel alleles and 38 novel suballeles were identified in the three genes due to identification of variants not covered by targeted genotyping assays. In addition, several ambiguous genotype calls from a previous study were resolved using the NGS and/or long-read NGS data. Diplotype calls were mostly consistent between the calling algorithms, although several discrepancies were noted. This study highlights the utility of NGS for pharmacogenetic testing and demonstrates that there are many novel alleles that are yet to be discovered, even in highly characterized genes such as CYP2C9 and CYP2C19.

[Magnetic resonance imaging quantitative analysis of knee joint injury and cartilage before and after long-distance march and training for college students]

Objective: To assess the effects of long-distance march and training on acute knee injury and knee cartilage sub-regions of college students using quantitatively magnetic resonance imaging analysis. Methods: Twenty-seven young male students from freshman classes in the Army Military Medical University were enrolled in September 2019, aged from 17 to 20 (19.48±0.14) years, participated in the whole 8-day, 240 km long-distance march and training. Three-dimensional quantitative MRI was performed on the right knee using high-field MRI before (baseline) and 1 day after (follow-up) march. The assessment indexes included: meniscus and cartilage injury(5-point scale), bone marrow and ligament injury, and joint effusion(3-point scale). Using semi-automatic cartilage segmentation and 3D data post-processing techniques, a total of 21 sub-regions of cartilage volume and thickness were measured in the medial and lateral femur, medial and lateral tibia. Paired-samples t-test was used to compare the changes in quantitative cartilage indices of the knee joint before and after march. Results: In terms of acute knee injuries, medial and lateral meniscus injuries (grade 1-3) occurred in 8 and 9 college students, respectively compared with those before march. Anterior cruciate ligaments injury occurred in 4 college students and developed from grade 0 to grade 1. Bone marrow edema occurred in 10 students and developed from grade 0 to grade 2, and in 5 students from grade 0 to grade 1. Joint effusion occurred in 5 college students and developed from grade 1 to grade 2 (all P<0.05). In terms of quantitative analysis of cartilage subregion of knee joint, the volume of central region of femoral pulley increased [(1.84±0.32) mm³ vs (1.67±0.29) mm³] and the volume of central region of medial femoral condyle decreased [(1.18±0.21) mm³ vs (1.26±0.17) mm³] compared with that before march (all P<0.05); The cartilage thickness of 11 cartilage subregion [(1.37±0.27) mm vs (1.53±0.18) mm], [(1.42±0.25) mm vs (1.54±0.17) mm], [(1.53±0.20) mm vs (1.62±0.20) mm], [(1.72±0.28) mm vs (1.83±0.28) mm], [(1.84±0.45) mm vs (2.04±0.42) mm], [(2.20±0.58) mm vs (2.46±0.50) mm], [(1.74±0.19) mm vs (1.85±0.21) mm] [(1.45±0.21) mm vs (1.58±0.16) mm], [(1.81±0.22) mm vs (1.91±0.15) mm], [(1.44±0.13) mm vs (1.53±0.15) mm] was thinner than that before march (all P<0.05). The T₂ values of 7 cartilage subregion [(40.57±26.23) ms vs (67.10±47.46) ms], [(80.10±20.56) ms vs (98.42±23.58) ms], [(87.92±24.95) ms vs (108.84±29.24) ms], [(50.49±19.18) ms vs (76.97±37.16) ms], [(38.89±15.82) ms vs (69.70±40.16) ms] [(55.84±24.53) ms vs (106.35±50.01) ms] and [(72.38±36.64) ms vs (105.31±39.34) ms] were lower than those before march, while the T₂ values of the two subregions of patellar cartilage [(102.13±44.47) ms vs (72.20±28.37) ms], [(97.42±44.86) ms vs (76.67±51.64) ms] were higher than those before march (P<0.05). There was no significant difference in other cartilage subareas (P>0.05). Conclusions: Long distance hiking will lead to acute injury of knee joint of young college students. The thickness of cartilage subregion of knee joint showed a thinning trend as a whole, while the volume and T₂ values showed different trends.

Remodeling tumor immunosuppressive microenvironment via a novel bioactive nanovaccines potentiates the efficacy of cancer immunotherapy

The clinical outcomes of cancer nanovaccine have been largely impeded owing to the low antigen-specific T cell response rate and acquired resistance caused by the immunosuppressive tumor microenvironment (TME). Here, we reported a tumor acidity-responsive nanovaccine to remodel the immunosuppressive TME and expand the recruitment of tumor infiltrating lymphocytes (TILs) using hybrid micelles (HM), which encapsulated colony stimulating factor 1 receptor (CSF1-R) inhibitor BLZ-945 and indoleamine 2,3-dioxygenase (IDO) inhibitor NLG-919 in its core and displayed a model antigen ovalbumin (OVA) on its surface (denoted as BN@HM-OVA). The bioactive nanovaccine is coated with a polyethylene glycol (PEG) shell for extending nanoparticle circulation. The shell can be shed in response to the weakly acidic tumor microenvironment. The decrease in size and the increase in positive charge may cause the deep tumor penetration of drugs. We demonstrated that the bioactive nanovaccine dramatically enhance antigen presentation by dendritic cells (DCs) and drugs transportation into M1-like tumor-associated macrophages (TAMs) and tumor cells via size reduction and increasing positive charge caused by the weakly acidic TME. Such bioactive nanovaccine could remodel the immunosuppressive TME into an effector T cells favorable environment, leading to tumor growth inhibition in prophylactic and therapeutic E.G7-OVA tumor models. Furthermore, combining the bioactive nanovaccine with simultaneous anti-PD-1 antibody treatment leads to a long-term tumor inhibition, based on the optimal timing and sequence of PD-1 blockade against T cell receptor. This research provides a new strategy for the development of efficient cancer immunotherapy.

•

A bioactive nanovaccine (BN@HM-OVA) was adopted for synergistic immunotherapy of E.G7-OVA tumors.

•

BN@HM-OVA exhibited superior ability to induce DCs maturation and robust antigen-specific T cell responses.

•

BN@HM-OVA contributed to a homeostasis in the tumor microenvironment ideal for antitumor vaccination.

•

The combination treatment of BN@HM-OVA and αPD-1 achieved maximum therapeutic benefits.

Single Molecule DNA Analysis Based on Atomic-Controllable Nanopores in Covalent Organic Frameworks

We explored the application of two-dimensional covalent organic frameworks (2D COFs) in single molecule DNA analysis. Two ultrathin COF nanosheets were exfoliated with pore sizes of 1.1 nm (COF-1.1) and 1.3 nm (COF-1.3) and covered closely on a quartz nanopipette with an orifice of 20 ± 5 nm. COF nanopores exhibited high size selectivity for fluorescent dyes and DNA molecules. The transport of long (calf thymus DNA) and short (DNA-80) DNA molecules through the COF nanopores was studied. Because of the strong interaction between DNA bases and the organic backbones of COFs, the DNA-80 was transported through the COF-1.1 nanopore at a speed of 270 μs/base, which is the slowest speed ever observed compared with 2D inorganic nanomaterials. This study shows that the COF nanosheet can work individually as a nanopore monomer with controllable pore size like its biological counterparts.

Exploration and practice of blended teaching of cell biology experiments during the COVID-19 epidemic

Since 2019, new coronavirus pneumonia has been widespread worldwide and has had a direct impact on human life. Meanwhile, it also has a huge impact on teaching in universities and hospitals, especially in experimental courses. Cell biology is not only an important part of biology but also one of the most dynamic frontier branches of modern life science, which is also a science based on experiments. It is necessary to promote the online and offline teaching during this special period. To explore and evaluate the blended teaching modes during the COVID-19 epidemic, we changed the previous single teaching mode of “teaching + experiment” and published courseware and learning requirements online before class, this kind of mode takes “theory + virtual demonstration experiment” in class as the main body and the reviewing and thinking after class as the summary. We also carried out offline practice on a small scale when the epidemic allowed and actively explored the comprehensive online and offline teaching modes, in and out of class. Through the hybrid teaching, the percentage distribution of students in high and moderate scores ranges were greatly increased, the blended teaching mode also greatly improves students’ subjective initiative and highlights the development of students’ personalized thinking and scientific research ability. The practice of this model not only ensures the health of teachers and students during the epidemic but also provides a new teaching exploration model and thinking for the development of experimental courses during the epidemic.

Non-muscle myosin II isoforms orchestrate substrate stiffness sensing to promote cancer cell contractility and migration

The stiffening of the extracellular matrix (ECM) during tumor progression results in an increase in cancer cell motility. In cell migration, two major isoforms of non-muscle myosin II (NMII), NMIIA and NMIIB, are expressed and assembled into the cytoskeleton. However, the isoform-specific regulatory roles of NMIIA and NMIIB as well as the underlying mechanisms in response to mechanical cues of the ECM are still elusive. Here, based on polyacrylamide (PAA) gels with tunable elastic modulus, we mimicked the mechanical properties of tumor tissue at different stages of breast cancer in vitro and investigated the distinct roles of NMII isoforms in the regulation of substrate stiffness. We demonstrate that NMIIA is engaged in establishing cell polarity by facilitating lamellipodia formation, focal adhesion turnover, and actin polymerization at the cell leading edge, while NMIIB is recruited to the cell perinuclear region and contributes to traction force generation and polarized distribution, both in a substrate stiffness-dependent manner. We further validated that substrate stiffness modulates the distribution and activation of NMII isoforms via the Rac1/p-PAK1/pS1916-NMIIA and PKCζ/pS1935-NMIIB signaling pathways in a site- and kinase-specific phosphoregulation manner. Our study is helpful for understanding the mechanotransduction of cancer cells and provides inspiration for molecular targets in antimetastatic therapy.

Relations of Variety and Quantity of Dietary Proteins Intake from Different Sources with Mortality Risk: A Nationwide Population-Based Cohort

OBJECTIVES

The relations of variety and quantity of dietary proteins intake from different sources with mortality risk were still controversial. We aimed to examine the associations of variety and quantity of different sourced proteins with all-cause mortality risk in adults and older adults.

MATERIALS AND METHODS

17,310 participants (mean age was 44.0 [SD: 15.9] years and 51.0% were females) with utilizable data from the China Health and Nutrition Survey were included. Dietary intake was collected using three consecutive 24-h dietary recalls combined with a household food inventory. The variety score of protein sources was defined as the number of proteins consumed at the appropriate level, accounting for both types and quantity of proteins. The primary outcome was all-cause mortality.

RESULTS

Over a median follow-up of 9.0 years, 1324 (7.6%) death cases were reported. There were reversed J-shaped relationships of percentages energy from total protein, and protein from legume with all-cause mortality; U-shaped relationships of proteins from unprocessed red meat, processed red meat, poultry and whole grain with all-cause mortality; L-shaped relationships of proteins from egg and fish with all-cause mortality; and a reversed L-shaped relationship of protein from refined grain with all-cause mortality (all P values for nonlinearity < 0.001). Moreover, there was a significant inverse association between the variety score of protein sources with overall mortality risk (per score increment, HR, 0.69; 95%CI, 0.66-0.72).

CONCLUSIONS

Greater variety of proteins with appropriate quantity from different food sources was associated with significantly lower risk of mortality in Chinese adults and older adults.

Dietary Iron Intake and New-Onset Hypertension: A Nationwide Cohort Study from China

OBJECTIVES

The relationship of dietary iron intake with the risk of hypertension remains uncertain. We aimed to investigate the prospective association between dietary iron intake and new-onset hypertension among Chinese adults.

DESIGN

A nationwide cohort study.

SETTING

Using data from seven rounds of the China Health and Nutrition Survey (CHNS) from 1997 to 2015.

PARTICIPANTS

A total of 12,245 participants without hypertension at baseline were included in this study.

EXPOSURES

Dietary intake was measured by three consecutive 24-h dietary recalls combined with a household weighing inventory.

MEASUREMENTS

The study outcome was new-onset hypertension, defined as systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg or diagnosed by physician or currently under antihypertensive treatment during the follow-up.

RESULTS

During a median follow-up of 6.1 years, 4,304 (35.1%) participants developed hypertension. Overall, there was a U-shaped association between dietary total iron intake and new-onset hypertension (P for nonlinearity <0.001), with the lowest risk observed at 18.2-<22.1 mg/day (quintile 2-3). Similarly, a U-shaped association between dietary nonheme iron intake and new-onset hypertension was found (P for nonlinearity <0.001), with the lowest risk at 17.4-<21.3 mg/day (quintile 2-3). However, the association between dietary heme iron intake and new-onset hypertension followed a L-shape (P for nonlinearity <0.001), and a significantly lower risk of new-onset hypertension was found in participants with quintile 2-5 of dietary heme iron intake (adjusted HR, 0.75; 95% CI: 0.68, 0.82), compared with those in quintile 1 (<0.25 mg/day).

CONCLUSIONS

The association between dietary iron and new-onset hypertension was nonlinear in Chinese adults, following a U-shape for total or nonheme iron intake, and a L-shape for heme iron intake.

Monitoring the electrochemical reactions on a gold nanoelectrode array via fluorescence-enabled electrochemical imaging

We first observed the electrochemical reaction on an independent gold nanoelectrode via super-resolution fluorescence imaging achieved by anchoring fluorescent molecules on the surface of the nanoelectrode and using an ionic liquid as the electrolyte.

Periodicities in the Daily Proton Fluxes from 2011 to 2019 Measured by the Alpha Magnetic Spectrometer on the International Space Station from 1 to 100 GV

We present the precision measurement of the daily proton fluxes in cosmic rays from May 20, 2011 to October 29, 2019 (a total of 2824 days or 114 Bartels rotations) in the rigidity interval from 1 to 100 GV based on 5.5×10^{9} protons collected with the Alpha Magnetic Spectrometer aboard the International Space Station. The proton fluxes exhibit variations on multiple timescales. From 2014 to 2018, we observed recurrent flux variations with a period of 27 days. Shorter periods of 9 days and 13.5 days are observed in 2016. The strength of all three periodicities changes with time and rigidity. The rigidity dependence of the 27-day periodicity is different from the rigidity dependences of 9-day and 13.5-day periods. Unexpectedly, the strength of 9-day and 13.5-day periodicities increases with increasing rigidities up to ∼10  GV and ∼20  GV, respectively. Then the strength of the periodicities decreases with increasing rigidity up to 100 GV.

Label-Free Electrochemiluminescence Imaging of Single-Cell Adhesions by Using Bipolar Nanoelectrode Array

A label-free and fast approach for positive electrochemiluminescence (ECL) imaging of single cells by bipolar nanoelectrode array is proposed. The reduction of oxygen at a platinized gold nanoelectrode array in a closed bipolar electrochemical system is coupled with an oxidative ECL process at the anodic side. For elevating the ECL imaging contrast of single cells, a driving voltage of -2.0 V is applied to in situ generate oxygen confined beneath cells that is subsequently used for ECL imaging at 1.1 V. High oxygen concentration in the confined space resulting from steric hindrance generates prominent oxygen reduction current at the cathodic side and higher ECL intensity at the anodic side, allowing positive ECL imaging of the cells adhesion region with excellent contrast. Cell morphology and adhesion strength can be successfully imaged with high image acquisition rate. This approach opens a new avenue for label-free imaging of single cells.

Light-responsive hyaluronic acid nanomicelles co-loaded with an IDO inhibitor focus targeted photoimmunotherapy against "immune cold" cancer

Nanomedicine enabled cancer combination immunotherapy not only sufficiently activates the host immune system, but also reprograms the immunosuppressive microenvironment, representing a new generation approach to treat cancer. Herein, we demonstrated a targeted photo- and immune-active nanoplatform termed NLG919@HA-Ce6 to simultaneously elicit efficient immunogenic cell death (ICD) using the photosensitizer Ce6 and modulate the tryptophan metabolic pathway using an indoleamine 2,3-dioxygenase (IDO) inhibitor NLG919 for the combined photodynamic therapy (PDT) and checkpoint blockade immunotherapy. Against the triple-negative and poorly immunogenic 4T1 breast cancer model, the stable spherical nanomicelle NLG919@HA-Ce6 selectively killed tumour cells via the toxic singlet oxygen upon laser excitation, thus in situ triggering a potent antitumor immune response, as seen via the obvious CRT exposure, ATP release, dendritic cell maturation, etc. Meanwhile, the IDO1-mediated immunosuppression was effectively reprogrammed to an immunostimulatory phenotype, which was accompanied by an enhanced cytotoxic T cell response as well as reduced Treg infiltration in tumour bed. Ultimately, the 4T1 tumour was synergistically suppressed by NLG919@HA-Ce6 due to the outcome of focused PDT, obvious ICD post PDT and IDO1 blockade. This study suggests the promise of NLG919@HA-Ce6 as an alternative simple, stimulative and targeted nanoagent to enable the whole-body photo-immune therapy against "immune cold" cancer.

Autophagy inhibitors increase the susceptibility of KRAS-mutant human colorectal cancer cells to a combined treatment of 2-deoxy-D-glucose and lovastatin

RAS-driven colorectal cancer relies on glucose metabolism to support uncontrolled growth. However, monotherapy with glycolysis inhibitors like 2-deoxy-D-glucose causes limited effectiveness. Recent studies suggest that anti-tumor effects of glycolysis inhibition could be improved by combination treatment with inhibitors of oxidative phosphorylation. In this study we investigated the effect of a combination of 2-deoxy-D-glucose with lovastatin (a known inhibitor of mevalonate pathway and oxidative phosphorylation) on growth of KRAS-mutant human colorectal cancer cell lines HCT116 and LoVo. A combination of lovastatin (>3.75 μM) and 2-deoxy-D-glucose (>1.25 mM) synergistically reduced cell viability, arrested cells in the G2/M phase, and induced apoptosis. The combined treatment also reduced cellular oxygen consumption and extracellular acidification rate, resulting in decreased production of ATP and lower steady-state ATP levels. Energy depletion markedly activated AMPK, inhibited mTOR and RAS signaling pathways, eventually inducing autophagy, the cellular pro-survival process under metabolic stress, whereas inhibition of autophagy by chloroquine (6.25 μM) enhanced the cytotoxic effect of the combination of lovastatin and 2-deoxy-D-glucose. These in vitro experiment results were reproduced in a nude mouse xenograft model of HCT116 cells. Our findings suggest that concurrently targeting glycolysis, oxidative phosphorylation, and autophagy may be a promising regimen for the management of RAS-driven colorectal cancers.

Population Pharmacokinetics and Exposure-Response Modeling of Daratumumab Subcutaneous Administration in Patients With Light-Chain Amyloidosis

The purpose of this study is to characterize the population pharmacokinetics (popPK) of subcutaneous (SC) daratumumab in combination with bortezomib, cyclophosphamide, and dexamethasone and explore the relationship between daratumumab systemic exposure and selected efficacy and safety end points in patients with newly diagnosed systemic amyloid light-chain amyloidosis. The popPK analysis included pharmacokinetic and immunogenicity data from patients receiving daratumumab SC in combination with bortezomib, cyclophosphamide, and dexamethasone in the ANDROMEDA study (AMY3001; safety run-in, n = 28; randomized phase, n = 183). Nonlinear mixed-effects modeling was used to characterize the popPK and quantify the impact of potential covariates. The exposure-response (E-R) analysis included data from all patients in the randomized phase of ANDROMEDA (n = 388). Logistic regression and survival analysis were used to evaluate the relationships between daratumumab systemic exposure and efficacy end points. The E-R analysis on safety was conducted using quartile comparison and logistic regression analysis. The observed concentration-time data of daratumumab SC were well described by a 1-compartment popPK model with first-order absorption and parallel linear and nonlinear Michaelis-Menten elimination pathways. None of the investigated covariates were determined to be clinically meaningful. Daratumumab systemic exposure was generally similar across subgroups that achieved different levels of hematologic response, and there was no apparent relationship between daratumumab systemic exposure and the investigated safety end points. In conclusion, the popPK and E-R analyses supported the selected 1800-mg flat dose of daratumumab SC in combination with bortezomib, cyclophosphamide, and dexamethasone regimen for the treatment of light-chain amyloidosis. No dose adjustment was recommended for investigated covariates.

Aptamer-Dendrimer Functionalized Magnetic Nano-Octahedrons: Theranostic Drug/Gene Delivery Platform for Near-Infrared/Magnetic Resonance Imaging-Guided Magnetochemotherapy

The combination of magnetic hyperthermia and chemotherapy within a nanosystem is thought to be a promising approach for cancer therapies. However, the nonspecific accumulation and fast clearance of magnetic nanoparticles in the physiological environment limited their further biomedical applications. Herein, we report a highly selective theranostic nanocomplex, ZIPP-Apt:DOX/siHSPs, built with superparamagnetic zinc-doped iron oxide nano-octahedral core, cationic PAMAM dendrimer, and functional surface modifications such as PEG, AS1411 aptamer, and fluorescent tags (FITC or Cy5.5), together with the loading of hydrophobic anticancer drug doxorubicin (DOX) and HSP70/HSP90 siRNAs. Our results demonstrate that the cellular uptake and the tumor-specific accumulation of ZIPP-Apt:DOX/siHSPs were significantly increased due to the AS1411-nucleolin affinity and further confirmed that the simultaneous depletion of HSP70 and HSP90 sensitized magnetic hyperthermia and chemotherapy-induced cell death both in vitro and in vivo. Altogether, our study provides a theranostic nanoplatform for aptamer-targeted, NIR/MR dual-modality imaging guided, and HSP70/HSP90 silencing sensitized magnetochemotherapy, which has the potential to advance versatile magnetic nanosystems toward clinical applications.

Erratum: Properties of a New Group of Cosmic Nuclei: Results from the Alpha Magnetic Spectrometer on Sodium, Aluminum, and Nitrogen [Phys. Rev. Lett. 127, 021101 (2021)]

This corrects the article DOI: 10.1103/PhysRevLett.127.021101.

Black carbon and dust in the Third Pole glaciers: Revaluated concentrations, mass absorption cross-sections and contributions to glacier ablation

In snow and ice, light-absorbing particles (LAPs), such as black carbon (BC) and dust, accelerate the melting of Third Pole glaciers (TPGs). In this study, we revaluated LAP concentrations in the snow pits of TPGs (SP-TPGs), measured LAP mass absorption cross-sections (MACs), and simulated their effects on glacier darkening and melting based on the Spectral Albedo Model for Dirty Snow and a surface energy and mass balance model. The results indicated that because of their short distances to emission sources, the average BC concentrations measured in snow pits in the periphery of Third Pole were much higher than those measured in the inland Tibetan Plateau, and the average dust concentrations generally decreased from north to south. The average MACs of BC in the SP-TPGs varied from 3.1 to 7.7 m² g^-1 at 550 nm, most of the average spectral values were comparable in the visible and near-infrared bands to those calculated by Mie theory, except those in Urumqi Glacier No. 1 (UR), Syek Zapadniy Glacier (SZ), and Laohugou Glacier No.12 (LH), while the average spectral MACs of dust in the SP-TPGs were considerably smaller in magnitude than most of the variations measured in other regions. Compared with the pure snow surfaces, BC and dust played comparable roles in reducing albedo in UR, SZ, LH, and Renlongba Glacier, whereas BC was the most prominent absorber in the other glaciers. The combined effect of BC and dust accelerated melting by 30.4-345.9 mm w.e. (19.7-45.3% of the total mass balance) through surface albedo darkening (0.06-0.17) and increased radiation absorption (25.8-65.7 W m^-2) within one month of the ablation season. This study provides a new data set of LAP concentrations and MACs and helps to clarify the roles of these factors in the cryospheric environment of the Third Pole.

Mercury sources and physicochemical characteristics in ice, snow, and meltwater of the Laohugou Glacier Basin, China

In this work, samples of surface snow, surface ice, snow pit and meltwater from the Laohugou Glacier No. 12 on the northern edge of Tibetan Plateau (TP) were collected during the summer of 2015. The average concentration of Hg in surface snow/ice was 22.41 ng L^-1, while the percentage of dissolved mercury (Hg_D) was observed to be around 26%. An altitudinal magnification of Hg was not observed for surface snow; however, in contrast, a significant positive magnification of Hg with altitude was observed in the surface ice. A higher concentration of Hg corresponded with the dust layer of the snow pit. It was observed that about 42% of Hg was lost from the surface snow when the glacier was exposed to sunlight within the first 24 h indicating some Hg was emitted back to the atmosphere while some were percolated downwards. The result from the principal component analysis (PCA) showed that the sources of Hg in Laohugou Glacier No. 12 were from crustal and biomass burning. Finally, it was estimated that total export of Hg from the outlet river of Laohugou glacier No. 12 in the year 2015 was about 1439.46 g yr^-1 with yield of 22.77 μg m² yr^-1. This study provides valuable insights for understanding the behavior of Hg in the glacier of the northern Tibetan Plateau.

Transmission event of SARS-CoV-2 delta variant reveals multiple vaccine breakthrough infections

BACKGROUND

This study aims to identify the causative strain of SARS-CoV-2 in a cluster of vaccine breakthroughs. Vaccine breakthrough by a highly transmissible SARS-CoV-2 strain is a risk to global public health.

METHODS

Nasopharyngeal swabs from suspected vaccine breakthrough cases were tested for SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) by qPCR (quantitative polymerase chain reaction) for Wuhan-Hu1 and alpha variant. Positive samples were then sequenced by Swift Normalase Amplicon Panels to determine the causal variant. GATK (genome analysis toolkit) variants were filtered with allele fraction ≥80 and min read depth 30x.

RESULTS

Viral sequencing revealed an infection cluster of 6 vaccinated patients infected with the delta (B.1.617.2) SARS-CoV-2 variant. With no history of vaccine breakthrough, this suggests the delta variant may possess immune evasion in patients that received the Pfizer BNT162b2, Moderna mRNA-1273, and Covaxin BBV152.

CONCLUSIONS

Delta variant may pose the highest risk out of any currently circulating SARS-CoV-2 variants, with previously described increased transmissibility over alpha variant and now, possible vaccine breakthrough.

FUNDING

Parts of this work was supported by the National Institute of Allergy and Infectious Diseases (1U19AI144297) and Baylor College of Medicine internal funding.

Notch-1 signaling promotes reattachment of suspended cancer cells by cdc42-dependent microtentacles formation

Circulating tumor cells (CTCs) are associated with a higher risk of metastasis in tumor patients. The adhesion and arrest of CTCs at a secondary site is an essential prerequisite for the occurrence of tumor metastasis. CTC reattachment has shown to be dependent on microtentacle (McTN) formation in vivo. However, the specific molecular mechanism of McTN formation in suspended cancer cells remains largely unclear. Here, we demonstrated that the activation of Notch-1 signaling triggers McTN formation to facilitate cell reattachment in suspended cell culture conditions. Moreover, molecular mechanistic studies revealed that McTN formation is governed by the balance between microtubule-driven outgrowth and actomyosin-driven cell contractility. The activation of Notch-1 downregulates the acetylation level of microtubules via the Cdc42/HDAC6 pathway, which contributes to microtubule polymerization. Simultaneously, Notch-1 signaling-induced Cdc42 activation also reduced phosphorylation of myosin regulatory light chain, leading to cell contractility attenuation. Altogether, these results defined a novel mechanism by which Notch-1 signaling disturbs the balance between the expansion of microtubules and contraction of the cortical actin, which promotes McTN formation and cell reattachment. Our findings provide a new perspective on the effective therapeutic target to prevent CTC reattachment.

RETRACTED: Liposomal valinomycin mediated cellular K+ leak promoting apoptosis of liver cancer cells

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the corresponding author. It has been found that Fig 2B contains manipulated components, and Fig 5A partially overlaps with Fig 6 of a published paper authored by Mirza Muhammad Faran Ashraf Baig, et, al., The effective transfection of a low dose of negatively charged drug-loaded DNA-nanocarriers into cancer cells via scavenger receptors, J. Pharm. Anal. 11 (2021) 174-182, https://doi.org/10.1016/j.jpha.2020.10.003. The corresponding author indicated that they cannot guarantee the integrity of the images in the manuscript, as well as the conclusions of the paper. As a result, the Editor-in-Chief has decided to retract the paper. The corresponding author deeply regrets the circumstances and apologizes to the scientific community for not having detected this prior to publication.