Targeting squalene epoxidase restores anti-PD-1 efficacy in metabolic dysfunction-associated steatohepatitis-induced hepatocellular carcinoma

OBJECTIVE

Squalene epoxidase (SQLE) promotes metabolic dysfunction-associated steatohepatitis-associated hepatocellular carcinoma (MASH-HCC), but its role in modulating the tumour immune microenvironment in MASH-HCC remains unclear.

DESIGN

We established hepatocyte-specific Sqle transgenic (tg) and knockout mice, which were subjected to a choline-deficient high-fat diet plus diethylnitrosamine to induce MASH-HCC. SQLE function was also determined in orthotopic and humanised mice. Immune landscape alterations of MASH-HCC mediated by SQLE were profiled by single-cell RNA sequencing and flow cytometry.

RESULTS

Hepatocyte-specific Sqle tg mice exhibited a marked increase in MASH-HCC burden compared with wild-type littermates, together with decreased tumour-infiltrating functional IFN-γ+ and Granzyme B+ CD8+ T cells while enriching Arg-1+ myeloid-derived suppressor cells (MDSCs). Conversely, hepatocyte-specific Sqle knockout suppressed tumour growth with increased cytotoxic CD8+ T cells and reduced Arg-1+ MDSCs, inferring that SQLE promotes immunosuppression in MASH-HCC. Mechanistically, SQLE-driven cholesterol accumulation in tumour microenvironment underlies its effect on CD8+ T cells and MDSCs. SQLE and its metabolite, cholesterol, impaired CD8+ T cell activity by inducing mitochondrial dysfunction. Cholesterol depletion in vitro abolished the effect of SQLE-overexpressing MASH-HCC cell supernatant on CD8+ T cell suppression and MDSC activation, whereas cholesterol supplementation had contrasting functions on CD8+ T cells and MDSCs treated with SQLE-knockout supernatant. Targeting SQLE with genetic ablation or pharmacological inhibitor, terbinafine, rescued the efficacy of anti-PD-1 treatment in MASH-HCC models.

CONCLUSION

SQLE induces an impaired antitumour response in MASH-HCC via attenuating CD8+ T cell function and augmenting immunosuppressive MDSCs. SQLE is a promising target in boosting anti-PD-1 immunotherapy for MASH-HCC.

CircNRCAM up-regulates NRCAM to promote papillary thyroid carcinoma progression

PURPOSE

Papillary Thyroid Carcinoma (PTC) is the most prevalent subtype of Thyroid Carcinoma (THCA), a type of malignancy in the endocrine system. According to prior studies, Neural Cell Adhesion Molecule (NRCAM) has been found to be up-regulated in PTC and stimulates the proliferation and migration of PTC cells. However, the specific mechanism of NRCAM in PTC cells is not yet fully understood. Consequently, this study aimed to investigate the underlying mechanism of NRCAM in PTC cells, the findings of which could provide new insights for the development of potential treatment targets for PTC.

METHODS AND RESULTS

Bioinformatics tools were utilized and a series of experiments were conducted, including Western blot, colony formation, and dual-luciferase reporter assays. The data collected indicated that NRCAM was overexpressed in THCA tissues and PTC cells. Circular RNA NRCAM (circNRCAM) was found to be highly expressed in PTC cells and to positively regulate NRCAM expression. Through loss-of-function assays, both circNRCAM and NRCAM were shown to promote the proliferation, invasion, and migration of PTC cells. Mechanistically, this study confirmed that precursor microRNA-506 (pre-miR-506) could bind with m6A demethylase AlkB Homolog 5 (ALKBH5), leading to its m6A demethylation. It was also discovered that circNRCAM could competitively bind to ALKBH5, which restrained miR-506-3p expression and promoted NRCAM expression.

CONCLUSION

In summary, circNRCAM could up-regulate NRCAM by down-regulating miR-506-3p, thereby enhancing the biological behaviors of PTC cells.

6PPD-quinone exposure induces neuronal mitochondrial dysfunction to exacerbate Lewy neurites formation induced by α-synuclein preformed fibrils seeding

The emerging toxicant N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine quinone (6PPD-Q) is of wide concern due to its ubiquitous occurrence and high toxicity. Despite regular human exposure, limited evidence exists about its presence in the body and potential health risks. Herein, we analyzed cerebrospinal fluid (CSF) samples from Parkinson's disease (PD) patients and controls. The CSF levels of 6PPD-Q were twice as high in PD patients compared to controls. Immunostaining assays performed with primary dopaminergic neurons confirm that 6PPD-Q at environmentally relevant concentrations can exacerbate the formation of Lewy neurites induced by α-synuclein preformed fibrils (α-syn PFF). Assessment of cellular respiration reveals a considerable decrease in neuronal spare respiratory and ATP-linked respiration, potentially due to changes in mitochondrial membrane potential. Moreover, 6PPD-Q-induced mitochondrial impairment correlates with an upsurge in mitochondrial reactive oxygen species (mROS), and Mito-TEMPO-driven scavenging of mROS can lessen the amount of pathologic phospho-serine 129 α-synuclein. Untargeted metabolomics provides supporting evidence for the connection between 6PPD-Q exposure and changes in neuronal metabolite profiles. In-depth targeted metabolomics further unveils an overall reduction in glycolysis metabolite pool and fluctuations in the quantity of TCA cycle intermediates. Given its potentially harmful attributes, the presence of 6PPD-Q in human brain could potentially be a risk factor for PD.

Lactobacillus acidophilus suppresses non-alcoholic fatty liver disease-associated hepatocellular carcinoma through producing valeric acid

BACKGROUND

Gut probiotic depletion is associated with non-alcoholic fatty liver disease-associated hepatocellular carcinoma (NAFLD-HCC). Here, we investigated the prophylactic potential of Lactobacillus acidophilus against NAFLD-HCC.

METHODS

NAFLD-HCC conventional and germ-free mice were established by diethylnitrosamine (DEN) injection with feeding of high-fat high-cholesterol (HFHC) or choline-deficient high-fat (CDHF) diet. Orthotopic NAFLD-HCC allografts were established by intrahepatic injection of murine HCC cells with HFHC feeding. Metabolomic profiling was performed using liquid chromatography-mass spectrometry. Biological functions of L. acidophilus conditional medium (L.a CM) and metabolites were determined in NAFLD-HCC human cells and mouse organoids.

FINDINGS

L. acidophilus supplementation suppressed NAFLD-HCC formation in HFHC-fed DEN-treated mice. This was confirmed in orthotopic allografts and germ-free tumourigenesis mice. L.a CM inhibited the growth of NAFLD-HCC human cells and mouse organoids. The protective function of L. acidophilus was attributed to its non-protein small molecules. By metabolomic profiling, valeric acid was the top enriched metabolite in L.a CM and its upregulation was verified in liver and portal vein of L. acidophilus-treated mice. The protective function of valeric acid was demonstrated in NAFLD-HCC human cells and mouse organoids. Valeric acid significantly suppressed NAFLD-HCC formation in HFHC-fed DEN-treated mice, accompanied by improved intestinal barrier integrity. This was confirmed in another NAFLD-HCC mouse model induced by CDHF diet and DEN. Mechanistically, valeric acid bound to hepatocytic surface receptor GPR41/43 to inhibit Rho-GTPase pathway, thereby ablating NAFLD-HCC.

INTERPRETATION

L. acidophilus exhibits anti-tumourigenic effect in mice by secreting valeric acid. Probiotic supplementation is a potential prophylactic of NAFLD-HCC.

FUNDING

Shown in Acknowledgments.

Bifidobacterium pseudolongum-generated acetate suppresses non-alcoholic fatty liver disease-associated hepatocellular carcinoma

BACKGROUND & AIMS

Recent studies have highlighted the role of the gut microbiota and their metabolites in non-alcoholic fatty liver disease-associated hepatocellular carcinoma (NAFLD-HCC). We aimed to identify specific beneficial bacterial species that could be used prophylactically to prevent NAFLD-HCC.

METHODS

The role of Bifidobacterium pseudolongum was assessed in two mouse models of NAFLD-HCC: diethylnitrosamine + a high-fat/high-cholesterol diet or + a choline-deficient/high-fat diet. Germ-free mice were used for the metabolic study of B. pseudolongum. Stool, portal vein and liver tissues were collected from mice for non-targeted and targeted metabolomic profiles. Two human NAFLD-HCC cell lines (HKCI2 and HKCI10) were co-cultured with B. pseudolongum-conditioned media (B.p CM) or candidate metabolites.

RESULTS

B. pseudolongum was the top depleted bacterium in mice with NAFLD-HCC. Oral gavage of B. pseudolongum significantly suppressed NAFLD-HCC formation in two mouse models (p < 0.01). Incubation of NAFLD-HCC cells with B.p CM significantly suppressed cell proliferation, inhibited the G1/S phase transition and induced apoptosis. Acetate was identified as the critical metabolite generated from B. pseudolongum in B.p CM, an observation that was confirmed in germ-free mice. Acetate inhibited cell proliferation and induced cell apoptosis in NAFLD-HCC cell lines and suppressed NAFLD-HCC tumor formation in vivo. B. pseudolongum restored heathy gut microbiome composition and improved gut barrier function. Mechanistically, B. pseudolongum-generated acetate reached the liver via the portal vein and bound to GPR43 (G coupled-protein receptor 43) on hepatocytes. GPR43 activation suppressed the IL-6/JAK1/STAT3 signaling pathway, thereby preventing NAFLD-HCC progression.

CONCLUSIONS

B. pseudolongum protected against NAFLD-HCC by secreting the anti-tumor metabolite acetate, which reached the liver via the portal vein. B. pseudolongum holds potential as a probiotic for the prevention of NAFLD-HCC.

IMPACT AND IMPLICATIONS

Non-alcoholic fatty liver disease-associated hepatocellular carcinoma (NAFLD-HCC) is an increasing healthcare burden worldwide. There is an urgent need to develop effective agents to prevent NAFLD-HCC progression. Herein, we show that the probiotic Bifidobacterium pseudolongum significantly suppressed NAFLD-HCC progression by secreting acetate, which bound to hepatic GPR43 (G coupled-protein receptor 43) via the gut-liver axis and suppressed the oncogenic IL-6/JAK1/STAT3 signaling pathway. Bifidobacterium pseudolongum holds potential as a novel probiotic for NAFLD-HCC prevention.

Lactobacillus gallinarum-derived metabolites boost anti-PD1 efficacy in colorectal cancer by inhibiting regulatory T cells through modulating IDO1/Kyn/AHR axis

OBJECTIVE

Gut microbiota is a key player in dictating immunotherapy response. We aimed to explore the immunomodulatory effect of probiotic Lactobacillus gallinarum and its role in improving anti-programmed cell death protein 1 (PD1) efficacy against colorectal cancer (CRC).

DESIGN

The effects of L. gallinarum in anti-PD1 response were assessed in syngeneic mouse models and azoxymethane/dextran sulfate sodium-induced CRC model. The change of immune landscape was identified by multicolour flow cytometry and validated by immunohistochemistry staining and in vitro functional assays. Liquid chromatography-mass spectrometry was performed to identify the functional metabolites.

RESULTS

L. gallinarum significantly improved anti-PD1 efficacy in two syngeneic mouse models with different microsatellite instability (MSI) statuses (MSI-high for MC38, MSI-low for CT26). Such effect was confirmed in CRC tumourigenesis model. L. gallinarum synergised with anti-PD1 therapy by reducing Foxp3+ CD25+ regulatory T cell (Treg) intratumoural infiltration, and enhancing effector function of CD8+ T cells. L. gallinarum-derived indole-3-carboxylic acid (ICA) was identified as the functional metabolite. Mechanistically, ICA inhibited indoleamine 2,3-dioxygenase (IDO1) expression, therefore suppressing kynurenine (Kyn) production in tumours. ICA also competed with Kyn for binding site on aryl hydrocarbon receptor (AHR) and antagonised Kyn binding on CD4+ T cells, thereby inhibiting Treg differentiation in vitro. ICA phenocopied L. gallinarum effect and significantly improved anti-PD1 efficacy in vivo, which could be reversed by Kyn supplementation.

CONCLUSION

L. gallinarum-derived ICA improved anti-PD1 efficacy in CRC through suppressing CD4+Treg differentiation and enhancing CD8+T cell function by modulating the IDO1/Kyn/AHR axis. L. gallinarum is a potential adjuvant to augment anti-PD1 efficacy against CRC.

Relativistic ultrafast electron diffraction at high repetition rates

The ability to resolve the dynamics of matter on its native temporal and spatial scales constitutes a key challenge and convergent theme across chemistry, biology, and materials science. The last couple of decades have witnessed ultrafast electron diffraction (UED) emerge as one of the forefront techniques with the sensitivity to resolve atomic motions. Increasingly sophisticated UED instruments are being developed that are aimed at increasing the beam brightness in order to observe structural signatures, but so far they have been limited to low average current beams. Here, we present the technical design and capabilities of the HiRES (High Repetition-rate Electron Scattering) instrument, which blends relativistic electrons and high repetition rates to achieve orders of magnitude improvement in average beam current compared to the existing state-of-the-art instruments. The setup utilizes a novel electron source to deliver femtosecond duration electron pulses at up to MHz repetition rates for UED experiments. Instrument response function of sub-500 fs is demonstrated with < 100 fs time resolution targeted in future. We provide example cases of diffraction measurements on solid-state and gas-phase samples, including both micro- and nanodiffraction (featuring 100 nm beam size) modes, which showcase the potential of the instrument for novel UED experiments.

An alternating continuous integration system for magnetic measurements for experimental advanced superconducting tokamak

Integrators are critical instruments used for magnetic measurement systems (MMSs) in tokamaks, and, currently, the Experimental Advanced Superconducting Tokamak (EAST) has over 600 deployed. However, these integrators, designed with real-time drift compensation, will not be able to support longer pulse operations in the near future due to saturation and drift. To address these issues, this paper proposes a new alternating integration system combining analog integration with drift digital rectification. This system utilizes a microcontroller unit (MCU) to control two parallel analog integrators to work alternatively, compensate their drifts based on their respective error characteristics, and assemble the two integration segments together. The designed architecture provides highly flexible capabilities in operation modes and error correction, which make the system operation and maintenance highly automated. Performance tests on the EAST experiment site show that the prototype integrator can meet the requirements of real-time plasma control for a duration of hour-level.

Roseburia intestinalis generated butyrate boosts anti-PD-1 efficacy in colorectal cancer by activating cytotoxic CD8+ T cells

OBJECTIVE

Roseburia intestinalis is a probiotic species that can suppress intestinal inflammation by producing metabolites. We aimed to study the role of R. intestinalis in colorectal tumourigenesis and immunotherapy.

DESIGN

R. intestinalis abundance was evaluated in stools of patients with colorectal cancer (CRC) (n=444) and healthy controls (n=575). The effects of R. intestinalis were studied in ApcMin/+ or azoxymethane (AOM)-induced CRC mouse models, and in syngeneic mouse xenograft models of CT26 (microsatellite instability (MSI)-low) or MC38 (MSI-high). The change of immune landscape was evaluated by multicolour flow cytometry and immunohistochemistry staining. Metabolites were profiled by metabolomic profiling.

RESULTS

R. intestinalis was significantly depleted in stools of patients with CRC compared with healthy controls. R. intestinalis administration significantly inhibited tumour formation in ApcMin/+ mice, which was confirmed in mice with AOM-induced CRC. R. intestinalis restored gut barrier function as indicated by improved intestinal permeability and enhanced expression of tight junction proteins. Butyrate was identified as the functional metabolite generated by R. intestinalis. R. intestinalis or butyrate suppressed tumour growth by inducing cytotoxic granzyme B+, interferon (IFN)-γ+ and tumour necrosis factor (TNF)-α+ CD8+ T cells in orthotopic mouse models of MC38 or CT26. R. intestinalis or butyrate also significantly improved antiprogrammed cell death protein 1 (anti-PD-1) efficacy in mice bearing MSI-low CT26 tumours. Mechanistically, butyrate directly bound to toll-like receptor 5 (TLR5) receptor on CD8+ T cells to induce its activity through activating nuclear factor kappa B (NF-κB) signalling.

CONCLUSION

R. intestinalis protects against colorectal tumourigenesis by producing butyrate, which could also improve anti-PD-1 efficacy by inducing functional CD8+ T cells. R. intestinalis is a potential adjuvant to augment anti-PD-1 efficacy against CRC.

Water-Level Fluctuation Control of the Trophic Structure of a Yangtze River Oxbow

Seasonal water-level fluctuations can profoundly impact nutrient dynamics in aquatic ecosystems, influencing trophic structures and overall ecosystem functions. The Tian-e-Zhou Oxbow of the Yangtze River is China's first ex situ reserve and the world's first successful case of ex situ conservation for cetaceans. In order to better protect the Yangtze finless porpoise, the effects of water-level fluctuations on the trophic structure in this oxbow cannot be ignored. Therefore, we employed stable isotope analysis to investigate the changes in the trophic position, trophic niche, and contribution of basal food sources to fish during the wet and dry seasons of 2021-2022. The research results indicate that based on stable isotope analysis of the trophic levels of different dietary fish species, fish trophic levels during the wet season were generally higher than those during the dry season, but the difference was not significant (p > 0.05). Fish communities in the Tian-e-Zhou Oxbow exhibited broader trophic niche space and lower trophic redundancy during the wet season (p < 0.05), indicating a more complex and stable food web structure. In both the wet and dry seasons, fish in the oxbow primarily relied on endogenous carbon sources, but there were significant differences in the way they were utilized between the two seasons (p < 0.05). In light of the changes in the trophic structure of the fish during the wet and dry seasons, and to ensure the stable development of the Yangtze finless porpoise population, we recommend strengthening the connectivity between the Tian-e-Zhou Oxbow and the Yangtze River.

Targeting of SLC25A22 boosts the immunotherapeutic response in KRAS-mutant colorectal cancer

KRAS is an important tumor intrinsic factor driving immune suppression in colorectal cancer (CRC). In this study, we demonstrate that SLC25A22 underlies mutant KRAS-induced immune suppression in CRC. In immunocompetent male mice and humanized male mice models, SLC25A22 knockout inhibits KRAS-mutant CRC tumor growth with reduced myeloid derived suppressor cells (MDSC) but increased CD8+ T-cells, implying the reversion of mutant KRAS-driven immunosuppression. Mechanistically, we find that SLC25A22 plays a central role in promoting asparagine, which binds and activates SRC phosphorylation. Asparagine-mediated SRC promotes ERK/ETS2 signaling, which drives CXCL1 transcription. Secreted CXCL1 functions as a chemoattractant for MDSC via CXCR2, leading to an immunosuppressive microenvironment. Targeting SLC25A22 or asparagine impairs KRAS-induced MDSC infiltration in CRC. Finally, we demonstrate that the targeting of SLC25A22 in combination with anti-PD1 therapy synergizes to inhibit MDSC and activate CD8+ T cells to suppress KRAS-mutant CRC growth in vivo. We thus identify a metabolic pathway that drives immunosuppression in KRAS-mutant CRC.

Parabacteroides distasonis uses dietary inulin to suppress NASH via its metabolite pentadecanoic acid

Non-alcoholic steatohepatitis (NASH) is the severe form of non-alcoholic fatty liver disease, and is characterized by liver inflammation and fat accumulation. Dietary interventions, such as fibre, have been shown to alleviate this metabolic disorder in mice via the gut microbiota. Here, we investigated the mechanistic role of the gut microbiota in ameliorating NASH via dietary fibre in mice. Soluble fibre inulin was found to be more effective than insoluble fibre cellulose to suppress NASH progression in mice, as shown by reduced hepatic steatosis, necro-inflammation, ballooning and fibrosis. We employed stable isotope probing to trace the incorporation of 13C-inulin into gut bacterial genomes and metabolites during NASH progression. Shotgun metagenome sequencing revealed that the commensal Parabacteroides distasonis was enriched by 13C-inulin. Integration of 13C-inulin metagenomes and metabolomes suggested that P. distasonis used inulin to produce pentadecanoic acid, an odd-chain fatty acid, which was confirmed in vitro and in germ-free mice. P. distasonis or pentadecanoic acid was protective against NASH in mice. Mechanistically, inulin, P. distasonis or pentadecanoic acid restored gut barrier function in NASH models, which reduced serum lipopolysaccharide and liver pro-inflammatory cytokine expression. Overall this shows that gut microbiota members can use dietary fibre to generate beneficial metabolites to suppress metabolic disease.

DpCoA tagSeq: Barcoding dpCoA-Capped RNA for Direct Nanopore Sequencing via Maleimide-Thiol Reaction

Recent discoveries of noncanonical RNA caps, such as nicotinamide adenine dinucleotide (NAD+) and 3'-dephospho-coenzyme A (dpCoA), have expanded our knowledge of RNA caps. Although dpCoA has been known to cap RNAs in various species, the identities of its capped RNAs (dpCoA-RNAs) remained unknown. To fill this gap, we developed a method called dpCoA tagSeq, which utilized a thiol-reactive maleimide group to label dpCoA cap with a tag RNA serving as the 5' barcode. The barcoded RNAs were isolated using a complementary DNA strand of the tag RNA prior to direct sequencing by nanopore technology. Our validation experiments with model RNAs showed that dpCoA-RNA was efficiently tagged and captured using this protocol. To confirm that the tagged RNAs are capped by dpCoA and no other thiol-containing molecules, we used a pyrophosphatase NudC to degrade the dpCoA cap to adenosine monophosphate (AMP) moiety before performing the tagSeq protocol. We identified 44 genes that transcribe dpCoA-RNAs in mouse liver, demonstrating the method's effectiveness in identifying and characterizing the capped RNAs. This strategy provides a viable approach to identifying dpCoA-RNAs that allows for further functional investigations of the cap.

MLK4 promotes glucose metabolism in lung adenocarcinoma through CREB-mediated activation of phosphoenolpyruvate carboxykinase and is regulated by KLF5

MLK4, a member of the mitogen-activated protein kinase kinase kinase (MAP3K) family, has been implicated in cancer progression. However, its role in lung adenocarcinoma has not been characterized. Here, we showed that MLK4 was overexpressed in a significant subset of lung adenocarcinoma, associated with a worse prognosis, and exerted an oncogenic function in vitro and in vivo. Bioinformatics analyses of clinical datasets identified phosphoenolpyruvate carboxykinase 1 (PCK1) as a novel target of MLK4. We validated that MLK4 regulated PCK1 expression at transcriptional level, by phosphorylating the transcription factor CREB, which in turn mediated PCK1 expression. We further demonstrated that PCK1 is an oncogenic factor in lung adenocarcinoma. Given the importance of PCK1 in the regulation of cellular metabolism, we next deciphered the metabolic effects of MLK4. Metabolic and mass spectrometry analyses showed that MLK4 knockdown led to significant reduction of glycolysis and decreased levels of glycolytic pathway metabolites including phosphoenolpyruvate and lactate. Finally, the promoter analysis of MLK4 unravelled a binding site of transcription factor KLF5, which in turn, positively regulated MLK4 expression in lung adenocarcinoma. In summary, we have revealed a KLF5-MLK4-PCK1 signalling pathway involved in lung tumorigenesis and established an unusual link between MAP3K signalling and cancer metabolism.

Rehybridization dynamics into the pericyclic minimum of an electrocyclic reaction imaged in real-time

Electrocyclic reactions are characterized by the concerted formation and cleavage of both σ and π bonds through a cyclic structure. This structure is known as a pericyclic transition state for thermal reactions and a pericyclic minimum in the excited state for photochemical reactions. However, the structure of the pericyclic geometry has yet to be observed experimentally. We use a combination of ultrafast electron diffraction and excited state wavepacket simulations to image structural dynamics through the pericyclic minimum of a photochemical electrocyclic ring-opening reaction in the molecule α-terpinene. The structural motion into the pericyclic minimum is dominated by rehybridization of two carbon atoms, which is required for the transformation from two to three conjugated π bonds. The σ bond dissociation largely happens after internal conversion from the pericyclic minimum to the electronic ground state. These findings may be transferrable to electrocyclic reactions in general.

Subspace Clustering via Structured Sparse Relation Representation

Due to the corruptions or noises that existed in real-world data sets, the affinity graphs constructed by the classical spectral clustering-based subspace clustering algorithms may not be able to reveal the intrinsic subspace structures of data sets faithfully. In this article, we reconsidered the data reconstruction problem in spectral clustering-based algorithms and proposed the idea of "relation reconstruction." We pointed out that a data sample could be represented by the neighborhood relation computed between its neighbors and itself. The neighborhood relation could indicate the true membership of its corresponding original data sample to the subspaces of a data set. We also claimed that a data sample's neighborhood relation could be reconstructed by the neighborhood relations of other data samples; then, we suggested a much different way to define affinity graphs consequently. Based on these propositions, a sparse relation representation (SRR) method was proposed for solving subspace clustering problems. Moreover, by introducing the local structure information of original data sets into SRR, an extension of SRR, namely structured sparse relation representation (SSRR) was presented. We gave an optimization algorithm for solving SRR and SSRR problems and analyzed its computation burden and convergence. Finally, plentiful experiments conducted on different types of databases showed the superiorities of SRR and SSRR.

Environmentally relevant concentrations of benzophenones triggered DNA damage and apoptosis in male Chinese rare minnows (Gobiocypris rarus)

Benzophenone-type ultraviolet (UV) filters (BPs) are commonly used as sunscreen agents, fragrance enhancers and plastic additives, and are great threats to aquatic organisms due to their high detected concentrations in the aquatic environment. However, few studies on their toxicity and mechanism in fish have been clearly reported. In this study, Chinese rare minnows (Gobiocypris rarus) were exposed to benzophenone (BP), 2,4-dihydroxybenzophenone (BP-1), and 5-benzoyl-4-hydroxy-2-methoxybenzenesulfonic acid (BP-4) at 5, 50, 500 µg/L for 28 d to assess their toxicity. Transcriptomics screening showed that cell cycle, DNA replication and repair were significantly altered pathways (p < 0.05). The altered transcripts were similar to those identified by RNA-seq. DNA damage and 8-OHdG levels were significantly increased at 50 and 500 μg/L groups (p < 0.05). The DNA methylcytosine level was not significantly changed exposure to BP, BP-1 and BP-4. TUNEL assays indicated that hepatic apoptosis was significantly improved at 500 μg/L BP and BP-4 and 50 and 500 μg/L BP-1 (p < 0.05), with the significantly increasing the activity of caspase-3, -8 and -9 (p < 0.05). Molecular docking analysis revealed that BP, BP-1 and BP-4 could bind differently to caspase-3 through different binding interactions. Therefore, BP-1 induced more serious oxidative DNA damage and apoptosis by activating caspase-3 than BP and BP-4, which will provide theoretical basis and data support for ecological evaluation of aquatic organisms induced by BPs.

Demirjian method and Willems method to study the dental age of adolescents in Shanghai before and after 10 years

BACKGROUND

The aim of this study is to assess the validity of whether the difference in dental age between 2009 to 2011 and 2021 is affected by environmental factors such as environmental pollution, floating population, and dietary habits. Demirjian and Willems dental age estimation methods were conducted for a Han population of children aged 8 to 14 in Shanghai, China. A total of 1,259 digital panorama radiographs of children aged 8.00-14.99 was estimated. All digital panorama radiographs were estimated using the Demirjian and Willems methods.

MATERIALS AND METHODS

Both 2009 to 2011 and 2021 were statistically analyzed by paired t-tests. The results show that the Demirjian method overestimates 2009 to 2011 and underestimates 2021 than children's chronological age. According to the Willms method, males are overestimated and females are underestimated from 2009 to 2011, and both genders were underestimated in 2021.

CONCLUSIONS

In conclusion, the difference in dental age between 2009 to 2011 and 2021 was statistically significant. Factors such as environment and dietary habits have been found to be affected by dental development. However, there are disputes among some researchers about the exact factors, so it is suggested to further study the effects of environmental factors on tooth development.

Exploring Lorentz Invariance Violation from Ultrahigh-Energy γ Rays Observed by LHAASO

Recently, the LHAASO Collaboration published the detection of 12 ultrahigh-energy γ-ray sources above 100 TeV, with the highest energy photon reaching 1.4 PeV. The first detection of PeV γ rays from astrophysical sources may provide a very sensitive probe of the effect of the Lorentz invariance violation (LIV), which results in decay of high-energy γ rays in the superluminal scenario and hence a sharp cutoff of the energy spectrum. Two highest energy sources are studied in this work. No signature of the existence of the LIV is found in their energy spectra, and the lower limits on the LIV energy scale are derived. Our results show that the first-order LIV energy scale should be higher than about 10^{5} times the Planck scale M_{Pl} and that the second-order LIV scale is >10^{-3}M_{Pl}. Both limits improve by at least one order of magnitude the previous results.

Assessment of benthic invertebrate diversity and river ecological status along an urbanized gradient using environmental DNA metabarcoding and a traditional survey method

Benthic invertebrate diversity is one of the most commonly used bioindicators for assessing aquatic ecosystem health in river systems. Although an increasing number of studies have focused on assessing benthic invertebrate diversity using environmental DNA metabarcoding and traditional survey methods, benthic invertebrate diversity and ecological status assessments performed across different landscapes within river systems have not been well documented. Here, the diversity and ecological status of benthic invertebrates and the influence of water quality on the invertebrate assemblage distribution along an urbanization gradient in rivers from the Jingjinji (JJJ) region, China, were investigated using eDNA metabarcoding and the traditional method. With the combination of the two methods, 395 benthic invertebrates from 6 phyla, 27 orders, 94 families, and 222 genera were identified. The species richness of the benthic invertebrate community in the mountain area was significantly higher than that in the urban and agricultural areas. Compared to the traditional results, eDNA metabarcoding obtained a significantly greater number of species from every sampling site (P = 0.000) and detected a notably higher abundance in Annelida (P = 0.000). Furthermore, the nonmetric multidimensional scaling (NMDS) and permutational multivariate analysis of variance (PERMANOVA) based on the Bray-Curtis dissimilarity index indicated that the benthic invertebrate communities from the different habitats were discriminated more accurately and easily using eDNA metabarcoding (P = 0.038) than with the traditional method (P = 0.829). Additionally, the assemblages identified by eDNA metabarcoding were more closely linked to water quality and could be realistically used to assess the ecological status of rivers. Our findings highlight that eDNA metabarcoding could represent a rapid and reliable method for estimating benthic invertebrate diversity and ecological status in river systems.

MiR-499b-5p inhibits cervical cancer cell proliferation and induces apoptosis by targeting the Notch1 signaling pathway

OBJECTIVE

We investigated the effect of miR-499b-5p on the tumorigenesis and development of cervical cancer by targeting the Notch1 signaling pathway to identify a new potential clinical target of cervical cancer.

PATIENTS AND METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to determine the mRNA expression levels of Notch1 and miR-499b-5p in cervical cancer tissues/cell lines. Cell counting kit-8 (CCK-8) assay, transwell assay, and flow cytometry were conducted to detect cell viability, cell migration, and cell apoptosis abilities. A Dual-Luciferase reporter assay was performed to test the binding site between miR-499b-5p and Notch1. An in vivo experiment was carried out using nude mice, and xenograft tumor models were established.

RESULTS

OD450 of the SiHa and HeLa cells of the miR-499b-5p agomir group was lower than that of the miR-499b-5p agomir-NC group. More apoptotic cells and fewer invasive cells were found in the former than in the latter. MiR-499b-5p inhibited the viability and migration of cervical cancer cells and promoted their apoptosis. Further detection of the Luciferase reporter gene confirmed the binding site of miR-499b-5p to Notch1. Western blot results showed that miR-499b-5p inhibited the expression of Notch1 and activated the expression of ChK2 and p-p38MAPK. Notch1 knockdown also inhibited the viability and migration of cervical cancer cells and promoted their apoptosis. MiR-499b-5p overexpression prevented the tumorigenesis and development of cervical cancer in xenograft tumor models.

CONCLUSIONS

MiR-499b-5p inhibits the proliferation of cervical cancer cells and induces their apoptosis by targeting the Notch1 signaling pathway.

Conformer-specific photochemistry imaged in real space and time

[Figure: see text].

Estimating aquatic plant diversity and distribution in rivers from Jingjinji region, China, using environmental DNA metabarcoding and a traditional survey method

Traditional survey methods (TSMs) are difficult to use to perform a census of aquatic plant diversity completely in river ecosystems, and improved aquatic plant community monitoring programs are becoming increasingly crucial with a continuous decline in diversity. Although environmental DNA (eDNA) metabarcoding has been applied successfully to assess aquatic biodiversity, limited work has been reported regarding aquatic plant diversity in rivers. In this study, the efficiency of eDNA to estimate the aquatic plant diversity and spatial distribution of rivers from the Jingjinji (JJJ) region was evaluated by comparing results obtained by the TSM. Based on a combination of the two methods, 157 aquatic plant species, including 24 hydrophytes, 61 amphibious plants, and 72 mesophytes, were identified. The spatial patterns in species richness and abundance by eDNA exhibited agreement with the TSM results with a gradual decline from the mountain area (MA) to the agricultural area (AA) and then to the urban area (UA). Compared to the TSM, eDNA identified a significantly greater number of species per site (p < 0.01) and obtained a significantly higher abundance in hydrophytes (p < 0.01), supplementing the unavailable abundance data from the TSM. Furthermore, the aquatic plant assemblages from the different areas were discriminated well using eDNA (p < 0.05), but they were better discriminated by the TSM (p < 0.01). Thus, our study provides more detailed data on aquatic plant diversity in rivers from the JJJ region, which is essential for biodiversity conservation. Our findings also highlight that eDNA can be reliable for evaluating aquatic plant diversity and has the potential to respond to landscape heterogeneity in river ecosystems.

Peta-electron volt gamma-ray emission from the Crab Nebula

The Crab Nebula is a bright source of gamma rays powered by the Crab Pulsar's rotational energy through the formation and termination of a relativistic electron-positron wind. We report the detection of gamma rays from this source with energies from 5 × 10^-4 to 1.1 peta-electron volts with a spectrum showing gradual steepening over three energy decades. The ultrahigh-energy photons imply the presence of a peta-electron volt electron accelerator (a pevatron) in the nebula, with an acceleration rate exceeding 15% of the theoretical limit. We constrain the pevatron's size between 0.025 and 0.1 parsecs and the magnetic field to ≈110 microgauss. The production rate of peta-electron volt electrons, 2.5 × 10³⁶ ergs per second, constitutes 0.5% of the pulsar spin-down luminosity, although we cannot exclude a contribution of peta-electron volt protons to the production of the highest-energy gamma rays.

Continuous detection of norovirus and astrovirus in wastewater in a coastal city of China in 2014-2016

Norovirus (NoV) and human astrovirus (HAstV) are important causative agents of acute gastroenteritis in children and adults. They are comprised of multiple genotypes and attention should be paid to genotype changes or emergence of new genetic variants. To study the prevalence and diversity of NoV GI, GII, and HAstV circulating in eastern China, we conducted a three-year environmental surveillance in a coastal city of Yantai. Thirty-six sewage samples were collected, processed, and examined for the presence of viral genomes by PCR. The results showed that NoV GI, GII, and HAstV were detected in all 36 samples. Six NoV GI genotypes, 11 NoV GII genotypes, and 5 HAstV serotypes were identified; GI.6, GII.17, and HAstV-5 were the most prevalent types, respectively. Persistent existence of NoV GII.17 Kawasaki 308 variant was observed during whole study period. Phylogenetic analysis reflected multiple transmission lineages in local population for both viruses. Our results reflect continuous presence of enteric viruses in sewage, improve our understanding on their molecular epidemiology, and demonstrate surveillance on sewage is an effective approach in understanding the local circulation of enteric viruses.

Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622+3749 Observed by LHAASO-KM2A

We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J0622+3749 with the Large High-Altitude Air Shower Observatory (LHAASO). The source is detected with a significance of 8.2σ for E>25  TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) =(95.47°±0.11°,37.92°±0.09°), and the extension is 0.40°±0.07°. The energy spectrum can be described by a power-law spectrum with an index of -2.92±0.17_{stat}±0.02_{sys}. No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations are consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of ∼160  TeV, is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars.

Squalene Epoxidase Induces Nonalcoholic Steatohepatitis Via Binding to Carbonic Anhydrase III and is a Therapeutic Target

BACKGROUNDS & AIMS

Squalene epoxidase (SQLE) is the rate-limiting enzyme for cholesterol biosynthesis. We elucidated the functional significance, molecular mechanisms, and clinical impact of SQLE in nonalcoholic steatohepatitis (NASH).

METHODS

We performed studies with hepatocyte-specific Sqle overexpression transgenic (Sqle tg) mice and mice given high-fat high-cholesterol (HFHC) or methionine- and choline-deficient (MCD) diet to induce NASH. SQLE downstream target carbonic anhydrase III (CA3) was identified using co-immunoprecipitation and Western Blot. Some mice were given SQLE inhibitor (terbinafine) and CA3 inhibitor (acetazolamide) to study the therapeutic effects in NASH. Human samples (N = 217) including 65 steatoses, 80 NASH, and 72 healthy controls were analyzed for SQLE levels in liver tissue and in serum.

RESULTS

SQLE is highly up-regulated in human NASH and mouse models of NASH. Sqle tg mice triggered spontaneous insulin resistance, hepatic steatosis, liver injury, and accelerated HFHC or MCD diet-induced NASH development. Mechanistically, SQLE tg mice caused hepatic cholesterol accumulation, thereby triggering proinflammatory nuclear factor-κB signaling and steatohepatitis. SQLE directly bound to CA3, which induced sterol regulatory element-binding protein 1C activation, acetyl-CoA carboxylase, fatty acid synthase, and stearoyl-CoA desaturase1 expression and de novo hepatic lipogenesis. Combined targeting SQLE (terbinafine) and CA3 (acetazolamide) synergistically ameliorated NASH in mice with superior efficacy to either drug alone. Serum SQLE with CA3 could distinguish patients with NASH from steatosis and healthy controls (area under the receiver operating characteristic curve, 0.815; 95% confidence interval, 0.758-0.871).

CONCLUSIONS

SQLE drives the initiation and progression of NASH through inducing cholesterol biosynthesis, and SQLE/CA3 axis-mediated lipogenesis. Combined targeting of SQLE and CA3 confers therapeutic benefit in NASH. Serum SQLE and CA3 are novel biomarkers for the noninvasive diagnosis of patients with NASH.

Ultrahigh-energy photons up to 1.4 petaelectronvolts from 12 γ-ray Galactic sources

The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 10¹⁵ electronvolts) indicates the existence of the so-called PeVatrons-cosmic-ray factories that accelerate particles to PeV energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays¹. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref. ²). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane^3-6, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators.

Inhibition of long non-coding RNA TSIX accelerates tibia fraction healing via binding and positively regulating the SOX6 expression

OBJECTIVE

Fragile fracture patients need to be treated with long-term fixation and the recovery process is slow. Several studies have shown that the fracture healing process is related to gene expression. We aimed to investigate the role of long chain non-coding RNA TSIX (lncRNA TSIX) on fracture healing after tibial fracture (TF) and explore the molecular mechanism underlying its action.

MATERIALS AND METHODS

The male C57BL/6J mice were used to construct TF models and osteoblasts were used as in vitro model. The proliferation, apoptosis, and osteogenesis-related genes of Col1a1, Col-II, and Col-X were detected to evaluate the role of lncRNA TSIX in vivo and in vitro after TF. Haematoxylin-eosin (HE) staining was conducted to confirm the fracture healing conditions.

RESULTS

We found that LncRNA TSIX expression in plasma of TF mice significantly upregulated in a time-dependent manner. Overexpression of lncRNA TSIX could significantly inhibit proliferation but promote apoptosis and regulate the osteogenesis-related genes expression by binding and positively regulate sex-determining region Y box 6 (SOX6) expression, while knockdown of lncRNA TSIX showed the opposite effect in osteoblastic cells. Inhibition of lncRNA TSIX could improve fracture healing after TF.

CONCLUSIONS

Taken together, our study supported that knockdown of lncRNA TSIX could promote the tibia fracture healing by binding and inhibiting the SOX6 expression. We suggest that lncRNA TSIX/SOX may be the potential targets for the treatment of TF.

CPVA: a web-based metabolomic tool for chromatographic peak visualization and annotation

MOTIVATION

Liquid chromatography-mass spectrometry-based non-targeted metabolomics is routinely performed to qualitatively and quantitatively analyze a tremendous amount of metabolite signals in complex biological samples. However, false-positive peaks in the datasets are commonly detected as metabolite signals by using many popular software, resulting in non-reliable measurement.

RESULTS

To reduce false-positive calling, we developed an interactive web tool, termed CPVA, for visualization and accurate annotation of the detected peaks in non-targeted metabolomics data. We used a chromatogram-centric strategy to unfold the characteristics of chromatographic peaks through visualization of peak morphology metrics, with additional functions to annotate adducts, isotopes and contaminants. CPVA is a free, user-friendly tool to help users to identify peak background noises and contaminants, resulting in decrease of false-positive or redundant peak calling, thereby improving the data quality of non-targeted metabolomics studies.

AVAILABILITY AND IMPLEMENTATION

The CPVA is freely available at http://cpva.eastus.cloudapp.azure.com. Source code and installation instructions are available on GitHub: https://github.com/13479776/cpva.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

In Colorectal Cancer Cells With Mutant KRAS, SLC25A22-Mediated Glutaminolysis Reduces DNA Demethylation to Increase WNT Signaling, Stemness, and Drug Resistance

BACKGROUND & AIMS

Mutant KRAS promotes glutaminolysis, a process that uses steps from the tricarboxylic cycle to convert glutamine to α-ketoglutarate and other molecules via glutaminase and SLC25A22. This results in inhibition of demethylases and epigenetic alterations in cells that increase proliferation and stem cell features. We investigated whether mutant KRAS-mediated glutaminolysis affects the epigenomes and activities of colorectal cancer (CRC) cells.

METHODS

We created Apc^minKras^G12D mice with intestine-specific knockout of SLC25A22 (Apc^minKras^G12DSLC25A22^fl/fl mice). Intestine tissues were collected and analyzed by histology, immunohistochemistry, and DNA methylation assays; organoids were derived and studied for stem cell features, along with organoids derived from 2 human colorectal tumor specimens. Colon epithelial cells (1CT) and CRC cells (DLD1, DKS8, HKE3, and HCT116) that expressed mutant KRAS, with or without knockdown of SLC25A22 or other proteins, were deprived of glutamine or glucose and assayed for proliferation, colony formation, glucose or glutamine consumption, and apoptosis; gene expression patterns were analyzed by RNA sequencing, proteins by immunoblots, and metabolites by liquid chromatography-mass spectrometry, with [U-¹³C₅]-glutamine as a tracer. Cells and organoids with knocked down, knocked out, or overexpressed proteins were analyzed for DNA methylation at CpG sites using arrays. We performed immunohistochemical analyses of colorectal tumor samples from 130 patients in Hong Kong (57 with KRAS mutations) and Kaplan-Meier analyses of survival. We analyzed gene expression levels of colorectal tumor samples in The Cancer Genome Atlas.

RESULTS

CRC cells that express activated KRAS required glutamine for survival, and rapidly incorporated it into the tricarboxylic cycle (glutaminolysis); this process required SLC25A22. Cells incubated with succinate and non-essential amino acids could proliferate under glutamine-free conditions. Mutant KRAS cells maintained a low ratio of α-ketoglutarate to succinate, resulting in reduced 5-hydroxymethylcytosine-a marker of DNA demethylation, and hypermethylation at CpG sites. Many of the hypermethylated genes were in the WNT signaling pathway and at the protocadherin gene cluster on chromosome 5q31. CRC cells without mutant KRAS, or with mutant KRAS and knockout of SLC25A22, expressed protocadherin genes (PCDHAC2, PCDHB7, PCDHB15, PCDHGA1, and PCDHGA6)-DNA was not methylated at these loci. Expression of the protocadherin genes reduced WNT signaling to β-catenin and expression of the stem cell marker LGR5. Apc^minKras^G12DSLC25A22^fl/fl mice developed fewer colon tumors than Apc^minKras^G12D mice (P < .01). Organoids from Apc^minKras^G12DSLC25A22^fl/fl mice had reduced expression of LGR5 and other markers of stemness compared with organoids derived from Apc^minKras^G12D mice. Knockdown of SLC25A22 in human colorectal tumor organoids reduced clonogenicity. Knockdown of lysine demethylases, or succinate supplementation, restored expression of LGR5 to SLC25A22-knockout CRC cells. Knockout of SLC25A22 in CRC cells that express mutant KRAS increased their sensitivity to 5-fluorouacil. Level of SLC25A22 correlated with levels of LGR5, nuclear β-catenin, and a stem cell-associated gene expression pattern in human colorectal tumors with mutations in KRAS and reduced survival times of patients.

CONCLUSIONS

In CRC cells that express activated KRAS, SLC25A22 promotes accumulation of succinate, resulting in increased DNA methylation, activation of WNT signaling to β-catenin, increased expression of LGR5, proliferation, stem cell features, and resistance to 5-fluorouacil. Strategies to disrupt this pathway might be developed for treatment of CRC.

Use of convalescent plasma therapy in eight individuals with mild COVID-19

Coronavirus disease 2019 (COVID-19) is still a global epidemic. Several studies of individuals with severe COVID-19 regard convalescent plasma (CP) transfusion as an effective therapy. However, no significant improvements are found in randomized clinical trials of CP treatment. Until now, data for individuals with mild COVID-19 transfused CP were lacking. This study recruited eight individuals with mild COVID-19 who received at least one dose of CP transfusion. After CP therapy, the clinical symptoms of all individuals improved. Lymphocyte counts tended to increase, and lactate dehydrogenase, creatine kinase and aspartate aminotransferase tended to decrease. However, C-reactive protein increased transiently in three individuals. The median time for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid test to become negative was 2.5 days after CP transfusion. The study shows the potential benefits of CP. Meanwhile, CP probably enhances the inflammatory response to SARS-CoV-2 temporarily in people with insufficient antiviral immunity. However, the effects of CP are not permanent.

[Molecular epidemiological characterization of group A rotavirus in domestic sewage in Jinan from 2016 to 2018]

Objective: To understand the detection of group A rotavirus (RVA) in domestic sewage and its molecular epidemiological characteristics, and further explore the feasibility and necessity of RVA environmental surveillance. Methods: From 2016 to 2018, we collected domestic sewage samples monthly in Jinan city, and concentrated them via anion membrane adsorption-elution method. Then RNA extraction and RVA VP7 and VP4 coding region RT-PCR amplification were performed. After purification, TA cloning and sequencing, homology analysis and phylogenetic analysis were conducted on the obtained sequences. Results: RVA G gene was detected in 31 of the 36 sewage samples (86.1% detection rate); RVA P genotype was detected in 33 samples (91.7% detection rate). A total of 536 RVA sequences were obtained, of which 225 G-type sequences belonged to 6 genotypes, and the G9 accounted for 92.4% (208/225); 311 P-type sequences were obtained, which belonged to 4 genotypes. The dominant P[8] accounted for 50.1% (156/311), followed by P[4] with 41.8% (130/311). Phylogenetic analysis shows that there were multiple transmission chains circulating in the dominant genotypes G9 and P[8]. Conclusion: The genotype, homology, and phylogenetic characteristics of sequences obtained from domestic sewage in Jinan area were described, which further confirmeing that RVA environmental surveillance is not feasible but also necessary.

Comparison of the efficacy and safety of the EC-T (epirubicin/cyclophosphamide followed by docetaxel) and TCb (docetaxel/carboplatin) neoadjuvant regimens in early TOP2A-normal stage II-III breast cancer

This study aimed to compare the efficacy and safety of the EC-T (4 cycles of epirubicin 90 mg/m2 + cyclophosphamide 600 mg/m2, followed by 4 cycles of docetaxel 75 mg/m2) and TCb (6 cycles of docetaxel 75 mg/m2, intravenous drip (ID), day 1 + carboplatin AUC 6, ID, day 1) neoadjuvant regimens in patients with TOP2A-normal stage II-III breast cancer. This study analyzed 280 patients enrolled from three studies registered with ClinicalTrials.gov (NCT03140553, NCT03154749, NCT03507465) with early TOP2A-normal stage II-III breast cancer who received neoadjuvant chemotherapy, including 100 patients who received the EC-T regimen and 180 patients who received the TCb regimen. The primary endpoint was the ratio of RCB 0/1 (residual cancer burden 0/1) after neoadjuvant chemotherapy. The secondary endpoint was the safety of the two groups. There was no significant difference in the ratio of RCB 0/1 between the two groups (23% vs. 23.9%, p=0.614). Among the triple-negative breast cancer patients, the efficacy did not differ between the two groups (40% vs. 32%, p=0.52). Among the lymph node metastasis patients, the efficacy of the EC-T group was significantly better than that of the TCb group (14% vs. 2.6%, p=0.03). Regarding the side effects, the incidence of grade 3/4 anemia was higher in the EC-T group than in the TCb group (21.0% vs. 8.33%, p=0.002), while the incidence of grade 3/4 neutropenia was higher in the EC-T group than in the TCb group (17% vs. 14.44%, p=0.570), and the incidence of grade 3/4 thrombocytopenia was low in each group (EC-T group: 6 % and TCb group: 7.22%, p=0.697). In the EC-T group, grade 3/4 nausea and vomiting occurred in 5 patients. The EC-T group showed a higher rate of grade 3/4 myalgia than the TCb group (7% and 4.44%, respectively, p=0.363). To conclude, the TCb regimen can be used as an alternative regimen for TOP2A-normal stage II-III breast cancer patients in neoadjuvant chemotherapy. However, in patients with node-positive tumors, EC-T is still recommended. Though no difference of grade 3/4 thrombocytopenia in two groups, grade 4 thrombocytopenia caused by the carboplatin-containing regimen should be taken seriously.

6-OH-BDE-47 exposure-induced Parkinson's disease pathology in Sprague Dawley rat

6-Hydroxy-BDE-47 (6-OH-BDE-47) is an important in vivo metabolite derived from 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), a ubiquitous environmental pollutant. The chemical has been widely detected in environmental and biological samples. However, as a potential neurotoxin, whether 6-OH-BDE-47 could promote the development of typical neurodegenerative diseases such as Parkinson's disease (PD) is still unknown. Here, we tested the potential PD-related neurotoxic effect of 6-OH-BDE-47 in rat. The chemical with levels of 0.1, 1 and 10 µg was stereotaxically injected into the right midbrain regions of rat where contain abundant dopaminergic neurons. The resulting deteriorated motor function and decreased levels of striatal dopamine and nigrostriatal tyrosine hydroxylase indicate the dopaminergic neuron loss after the injection. Proteomics study revealed that protein degradation pathways were affected. Western blot analysis confirmed that 6-OH-BDE-47 could inhibit ubiquitination and autophagy, resulting in the increased formation of α-synuclein (α-syn) aggregate, an important pathological hallmark of PD. Overall, our study demonstrated that the 6-OH-BDE-47 administration could induce motor defect by impairing dopaminergic system and promote α-syn aggregation by inhibiting ubiquitination and autophagy, suggesting that the occurrence of 6-OH-BDE-47 in brain could be a risk for developing PD.

Study of metabolic disorders associated with BDE-47 exposure in Drosophila model by MS-based metabolomics

Epidemiological and animal studies have revealed a possible linkage between 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) exposure and neurodegenerative disease such as Parkinson's disease (PD). However, whether or how BDE-47 would affect the PD progression remains unclear. Here, we carried out a metabolomics study based on liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) to investigate the possible contribution of BDE-47 exposure to PD progression in Drosophila (fly) model. Transgenic PD flies were exposed to BDE-47 through diet for 30 days. Global metabolomic analysis identified 48 altered metabolites after the exposure. These metabolites were mainly involved in tryptophan metabolism, phenylalanine metabolism, purine metabolism, and alanine, aspartate and glutamate metabolism. Further, by quantifying metabolites of interest using LC-MS/MS, we confirmed that the formation of neuro-protector kynurenic acid was slowed down while the formation of neurotoxin 3-hydroxy-kynurenine was speeded up on the 20^th exposure day. Moreover, the levels of SAM/SAH (an index of methylation potential) and GSH/GSSG (an indicator of oxidative stress) were found to decrease on the 30^th exposure day. Our results suggest that BDE-47 could induce imbalance of kynurenine metabolism and methylation potential, and oxidative stress, which might further accelerate PD progression.

[Analysis of differences in epidemiology and clinical features of Guillain-Barré syndrome between rural and urban areas of southern China]

Objective: To explore the differences in epidemiology and clinical features of Guillain- Barré syndrome (GBS) between rural and urban areas of southern China. Methods: The clinical data of 759 hospitalized GBS patients from 31 hospitals of 13 provinces/cities in southern China, between January 1st, 2013 and September 30th, 2016, were collected and analyzed retrospectively. Results: The risk of GBS was higher for males than females in rural and urban areas and the median age was 49 and 48 years, respectively. Seasonal clustering in winter and spring was noted in both rural and urban areas, and the seasonal trend was more markedly in rural areas, but the differences showed no statistical significance. There were 70.37% of patients in rural areas and 73.69% in urban areas who had antecedent respiratory infection. The median time from onset to nadir was 7 days, and Hughes Disability Scale at admission, nadir and discharge were (2.95±1.10 vs 2.84±1.15), (3.25±1.11 vs 3.14±1.21), (2.02±1.24 vs 2.00±1.31) in rural and urban areas respectively. Albuminocytologic dissociation was present in 84.34% of patients in rural areas and 84.62% of cases in urban areas. There were 8.65% and 10.94% of cases in rural and urban areas who required mechanical ventilation during hospitalization, respectively. Demyelinating GBS accounted for 53.29% and 48.77%, respectively, in patients with findings of nerve conduction studies available in rural and urban areas. Conclusions: GBS in rural areas of southern China showed male predominance and a peak of spring and winter occurrence, with respiratory infection as the predominated preceding events and demyelinating GBS being main clinical subtype. Winter and spring showed a higher incidence of GBS in rural and urban areas. There were no significant differences of sex, age, preceding events, season trend, progression of disease, clinical subtypes and cerebrospinal fluid investigations in GBS patients between rural and urban areas.

Study of BDE-47 induced Parkinson's disease-like metabolic changes in C57BL/6 mice by integrated metabolomic, lipidomic and proteomic analysis

As the predominant congener of polybrominated diphenyl ethers (PBDEs) detected in human serum, 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) has been reported to induce neurotoxicity. However, the possible linkage between BDE-47 and typical neurodegenerative diseases such as Parkinson's disease (PD) is still unclear. Here we carried out omics studies using liquid chromatography-orbitrap mass spectrometry (LC-orbitrap MS) to depict the BDE-47 induced metabolic changes in C57BJ/L mice to explore the possible contribution of BDE-47 exposure to PD pathology. BDE-47 dissolved in corn oil was orally administered to mice for 30 consecutive days. Results of metabolomics and lipidomics studies of PD-related brain regions revealed significant metabolite changes in pathways involved in oxidative stress and neurotransmitter production. Moreover, isobaric tags for relative and absolute quantitation (iTRAQ) proteomics study of the striatum, which is the part of brain that is most intensively studied in PD pathogenesis, revealed that BDE-47 could induce neurotransmitter system disturbance, abnormal phosphorylation, mitochondrial dysfunction and oxidative stress. Overall, this study depicts the possible contribution of BDE-47 exposure to PD pathology and highlights the powerfulness of omics platforms to deepen the mechanistic understanding of environmental pollutant-caused toxicity.

Variations of phthalate exposure and metabolism over three trimesters

Maternal exposure to phthalates may cause some adverse health effects on both mother and fetus, but variations of phthalate exposure and metabolism during pregnancy have not been thoroughly characterized. A total of 946 participants were selected from a cohort study conducted in Wuhan between 2014 and 2015 through which they had provided a complete set of urine samples at three trimesters. Eight phthalate metabolites were analyzed in 2838 urine samples. Based on urinary concentrations, various parameters (i.e. phthalate metabolite concentrations, ratios of metabolites of bis(2-ethylhexyl) phthalate (DEHP) in DEHP, and percentages of individual metabolites in total phthalates) were compared over three visits. We observed that levels of phthalate metabolites showed a U-shaped trend across three trimesters. The significant variations in the ratios of DEHP metabolites indicated that the efficiency in metabolizing DEHP declined during pregnancy and less recent exposure occurred in mid-pregnancy. The changes of percentages of individual compound in total phthalates suggested the inconsistent pattern over trimesters. This longitudinal study found that the exposure pattern, exposure timing and metabolic susceptibility varied by trimesters, which suggests that urine samples should be collected at multiple time points and mothers should be especially careful in the early pregnancy.

Formation of dioxins from triclosan with active chlorine: A potential risk assessment

Triclosan, a widely used antimicrobial agent, can increase colitis-associated colon tumorigenesis, and induce liver fibrosis and cancer in mice through mechanisms which may be relevant in humans. In this study, an analytical method using gas chromatography-mass spectrometry (GC-MS) and high resolution gas chromatography-high resolution mass spectrometry (HRGC-HRMS) was developed to measure dioxins and chlorinated derivatives from triclosan in the presence of active chlorine in seawater matrix. Formation yields of dioxins and chlorinated triclosans were assessed at different initial precursor concentrations under dark and UV light irradiation conditions. Results showed that triclosan was rapidly transformed to its chlorinated derivatives, i.e. tetraclosans and pentaclosans, of which the formation yields peaked after 1 h of reaction. UV light was the key factor to promote the formation of dioxins. With the same initial triclosan/active chlorine ratio, the highest yield of dioxins was observed with lower initial concentrations of triclosan under UV irradiation. Five dioxins, including 2,8-DCDD, 1,2,8-TrCDD, 2,3,7-TrCDD, 1,2,3,8-TeCDD, and 2,3,7,8-TeCDD, were identified and quantified. 2,3,7,8-TeCDD, the most toxic dioxin, was firstly reported as the photo-transformation product of triclosan in aquatic solution. Results presented here are useful for a comprehensive understanding of the fate and toxicity of triclosan in contaminated waters.

A dual-zwitterion functionalized ultra-hydrophilic metal–organic framework with ingenious synergy for enhanced enrichment of glycopeptides

A rational strategy was introduced for the synthesis of a novel dual functionalized metal–organic framework nanocomposite (AuGC/ZIF-8) with ultra-hydrophilicity to enhance glycopeptide enrichment.