Ionizable STING-Activating Nanoadjuvants Enhance Tumor Immunogenicity and Potentiate Immunotherapy Efficacy in Solid Tumors.

Therapeutic strategies that induce inflammatory responses in immunologically "cold" tumors have the potential to improve immunotherapeutic outcomes. Pharmacologically activating the STING pathway induces innate immunity, subsequently enhancing tumor immunogenicity. Here, we developed a nanoadjuvant with tumor-restricted pharmacology that rapidly activated STING and reshaped the tumor microenvironment (TME). The non-nucleotide STING agonist MSA-2 was chemically engineered with a piperazine motif linked by a saturated hydrocarbon chain of varying lengths to produce ionizable prodrugs that were further developed into nanoadjuvants. Compared with state-of-the-art liposomes, the nanoadjuvant displayed prolonged retention in the circulation and improved intratumoral delivery. In the acidic TME, the nanoadjuvant underwent polyethylene glycol deshielding, enabling efficient extravasation and penetration into tumors. Concomitantly, the STING prodrug escaped from the endo/lysosome compartment to partition into the cytosol for spontaneous esterase-catalyzed drug activation. In mouse models of syngeneic and chemically induced colorectal cancers, nanoparticle treatment provoked robust STING-mediated antitumor immunity, shifting the tumor immune landscape from immunosuppressed to tumoricidal. Additionally, the nanoadjuvant demonstrated antitumor efficacy in triple-negative breast cancer, which was further enhanced by the addition of immune checkpoint inhibitors. Collectively, this study demonstrates the safety and immune stimulating effects of a STING-activating nanoadjuvant, supporting the clinical evaluation of this STING immunotherapeutic alone and in combination with other immunotherapies.

Role of cspA on the Preparation of Escherichia coli Competent Cells by Calcium Chloride Method.

One of the fundamental techniques in genetic engineering is the creation of Escherichia coli competent cells using the CaCl2 method. However, little is known about the mechanism of E. coli competence formation. We have previously found that the cspA gene may play an indispensable role in the preparation of E. coli DH5α competent cells through multiomics analysis. In the present study, the cellular localization, physicochemical properties, and function of the protein expressed by the cspA gene were analyzed. To investigate the role of the cspA gene in E. coli transformation, cspA-deficient mutant was constructed by red homologous recombination. The growth, transformation efficiency, and cell morphology of the cspA-deficient strain and E. coli were compared. It was found that there were no noticeable differences in growth and morphology between E. coli and the cspA-deficient strain cultured at 37°C, but the mutant exhibited increased transformation efficiencies compared to E. coli DH5α for plasmids pUC19, pET-32a, and p1304, with enhancements of 2.23, 2.24, and 3.46 times, respectively. It was proved that cspA gene is an important negative regulatory gene in the CaCl2 preparation of competent cells.

Bibliometric analysis of traditional Chinese medicine in the treatment of inflammatory bowel disease.

OBJECTIVE: This study conducts a bibliometric analysis of literature on the treatment of inflammatory bowel disease (IBD) with traditional Chinese medicine (TCM) to explore its research status, hotspots, and development trends, providing ideas and references for further research. METHOD: We screened literature for treating IBD with TCM from the Web of Science Core Collection (WOSCC), and used the VOSviewer software (1.6.18) to discover cooperation among countries, institutions, authors, and information on journals, keywords, etc. We use the CiteSpace software (6.2.R2) to analyze co-citation and burst discovery of references. RESULTS: In all, 440 relevant literature papers were searched and screened from the WOSCC database. The results showed that the number of publications concerning treating IBD with TCM has shown a significant growth in the past decade. China is far ahead in terms of article output, occupying a dominant position. The institution with the most published articles is Nanjing University of Traditional Chinese Medicine. The authors who have published most of the articles are Dai Yancheng, Shi Rui, and Zhou Lian. The Journal of Ethnopharmacology published maximum articles in this field, while Gastroenterology was the most cited journal. Ungaro et al.'s article entitled "Ulcerative colitis" (https://doi.org/10.1016/S0140-6736(16)32126-2), published in The Lancet in 2017 was the most cited study. The high-frequency keywords mainly include ulcerative colitis, inflammation, NF-κB, expression, traditional Chinese medicine, gut microbiota, activation, mice, cells, etc. CONCLUSIONS: The research heat for treating IBD with TCM has risen over the past decade, with studies focusing on three main aspects: clinical studies of TCM, basic pharmacology, and animal experimental research. The research hotspot shifted from pathogenesis, clinical study of TCM, basic pharmacology, and complementary therapies to the study of network pharmacology and the mechanism of action of TCM related to gut microbiota. Network pharmacology and gut microbiota are at the frontiers of research and turning to be the future research trends to provide new insights and ideas for further research for treating IBD with TCM.

Chemically engineered mTOR-nanoparticle blockers enhance antitumour efficacy.

BACKGROUND: Hepatocellular carcinoma (HCC) is a highly prevalent and deadly type of cancer, and although pharmacotherapy remains the cornerstone of treatment, therapeutic outcomes are often unsatisfactory. Pharmacological inhibition of mammalian target of rapamycin (mTOR) has been closely associated with HCC regression. METHODS: Herein, we covalently conjugated AZD8055, a potent mTORC1/2 blocker, with a small panel of unsaturated fatty acids via a dynamically activating linkage to enable aqueous self-assembly of prodrug conjugates to form mTOR nanoblockers. Cell-based experiments were carried out to evaluate the effects of the nanoblocker against hepatocellular carcinoma (HCC) cells. The orthotopic and subcutaneous HCC mouse models were established to examine its antitumour activity. FINDINGS: Among several fatty acids as promoieties, linoleic acid-conjugated self-assembling nanoblocker exhibited optimal size distribution and superior physiochemical properties. Compared with free agents, PEGylated AZD8055 nanoblocker (termed AZD NB) was pharmacokinetically optimized after intravenous administration. In vivo investigations confirmed that AZD NB significantly suppressed tumour outgrowth in subcutaneous HCCLM3 xenograft, Hepatoma-22, and orthotopic Hepa1-6 liver tumour models. Strikingly, treatment with AZD NB, but not free agent, increased intratumour infiltration of IFN-γ+CD8+ T cells and CD8+ memory T cells, suggesting a potential role of the mTOR nanoblocker to remodel the tumour microenvironment. Overall, a single conjugation with fatty acid transformed a hydrophobic mTOR blocker into a systemically injectable nanomedicine, representing a facile and generalizable strategy for improving the therapeutic index of mTOR inhibition-based cancer therapy. INTERPRETATION: The mTOR inhibition by chemically engineered nanoblocker presented here had enhanced efficacy against tumours compared with the pristine drug and thus has the potential to improve the survival outcomes of patients with HCC. Additionally, this new nanosystem derived from co-assembling of small-molecule prodrug entities can serve as a delivery platform for the synergistic co-administration of distinct pharmaceutical agents. FUNDING: This work was supported by the National Natural Science Foundation of China (32171368,81721091), the Zhejiang Provincial Natural Science Foundation of China (LZ21H180001), the Jinan Provincial Laboratory Research Project of Microecological Biomedicine (JNL-2022039c and JNL-2022010B), State Key Laboratory for Diagnosis and Treatment of Infectious Diseases (zz202310), and Natural Science Foundation of Shandong Province (ZR2023ZD59).

Generation of a human iPSC line from a Parkinson's disease patient with a novel CHCHD2 mutation (p.R145Q).

Mutations in CHCHD2 have been reported to be associated with familial Parkinson's disease (PD). We generated a human induced pluripotent stem cell (hiPSC) line by reprogramming dermal fibroblasts from a PD patient harboring a novel CHCHD2 mutation (c.434G > A, p.R145Q). This line exhibited human embryonic stem cell (hESC)-like clonal morphology, expression of undifferentiated stem cell markers, a normal karyotype and trilineage differentiation capacity and thus the potential to serve as a model for further investigating the underlying molecular mechanisms of CHCHD2 function in PD.

Discharge coefficient of vertical sluice gates with broad crested weir under free-submerged orifice flows using best subset regression.

Accurate calculation of flow discharge for sluice gates is essential in irrigation, water supply, and structure safety. The measurement of discharge with the requirement of distinguishing flow regimes is not conducive to application. In this study, a novel approach that considers both free and submerged flow was proposed. The energy-momentum method was employed to derive the coefficient of discharge. Subsequently, the discharge coefficient was determined through the experiment which was performed on the physical model of a vertical sluice gate with a broad-crested weir. Feature engineering, incorporating dimensional analysis, feature construction, and correlation-based selection were performed. The best subset regression method was employed to develop regression equations of the discharge coefficient with the generated features. The derived formula was applied to compute the discharge coefficient in the vertical sluice gate and determine the flow discharge. The accuracy of adopted method was assessed by comparing it with recent studies on submerged flow, and the results demonstrate that the developed approach achieves a high level of accuracy in calculating flow discharge. The coefficient of determination for the calculated flow rate is 0.993, and the root mean square percentage error is 5.04%.

Visual analysis of global hemorrhagic fever with renal syndrome research from 1980 to 2022: Based on CiteSpace and VOSviewer.

OBJECTIVE: The development and current state of hemorrhagic fever with renal syndrome (HFRS) over the past 40 years are analyzed in this study, along with explored and discovered the hotspots and frontiers in the field, which serve as the foundation for future investigation. METHODS: CiteSpace and VOSviewer analysis software were used to visually analyze the literature data on HFRS from 1980 to 2022, including the annual number of publications, countries and research institutions, authors, co-cited literature and keywords. RESULTS: The number of pertinent papers published in the field of HFRS displayed an overall upward trend from 1980 to 2022. The United States, China, Germany, Sweden, and France are the top 5 countries in terms of publishing volume, with high intermediate centrality mainly concentrated in Europe and the United States. The top 10 co-occurring keywords were hemorrhagic fever, renal syndrome, infection, virus, epidemic, nephropathia epidemical, disease, hantavirus, outbreak, and transmission. According to keyword cluster analysis, there were 4 main research fields. In the HFRS-related study, there were mainly 21 notable keywords and "Korean hemorrhagic fever" had the highest hemorrhagic value (28.87). CONCLUSION: The United States, China, Germany, Sweden and other countries attached great importance to the HFRS-related research. Moreover, the collaboration between authors and institutions in various collaborator clusters should be strengthened. In recent decades, investigations have focused on the study of viral infection and the clinical symptoms and pathophysiology of HFRS. Future research may concentrate on factors affecting host population distribution and density, such as vaccine development and meteorological factors pertaining to virus transmission.

[Application Progress of Resting-State Functional Magnetic Resonance Imaging in Study of Default Mode Network in Patients with Vascular Cognitive Impairment].

Vascular cognitive impairment（VCI） is a group of syndromes ranging from mild cognitive impairment to dementia caused by cerebrovascular disease, due to the lack of sensitivity and specific biomarkers, it is difficult to identify and diagnose early. Abnormal connectivity is observed in brain regions of patients with vascular cognitive disorders, locates mainly in the default mode network（DMN）, and changes in their abnormal functional connectivity correlated with the degree of patients' cognitive impairment. Resting-state functional magnetic resonance imaging(rs-fMRI) is a commonly used method to detect the internal activity of the brain at resting state. The use of various rs-fMRI to study abnormal changes in the DMN in patients with VCI is useful to further investigate the pathogenesis of VCI and provide an objective basis for imaging. This article mainly reviews the application of rs-fMRI in the DMN in patients with VCI, bringing new perspectives for the correct diagnosis and assessment of VCI.

METTL3-mediated HSPA9 m6A modification promotes malignant transformation and inhibits cellular senescence by regulating exosomal mortalin protein in cervical cancer.

The role of RNA methyltransferase 3 (METTL3) in tumor progression when tethered to aberrantly expressed oncogenes remains unknown. In especial, the correlation between cervical cancer (CCa)-derived exosomes and m6A methylation in malignant traits of cervical epithelium is currently elusive. Mortalin expression was found to be up-regulated in plasma exosomes isolated from CCa patients. Furthermore, mortalin gained increased mRNA stability and enhanced translation efficiency via the m6A methylation in the HSPA9 mRNA 3'UTR, which was catalysed by METTL3 in CCa cells. Exosomal mortalin overexpression significantly promoted the proliferation, migration and invasion of CCa both in vitro and in vivo. Additionally, exosome-encapsulated mortalin suppressed cellular senescence and facilitated malignant transformation by blocking nuclear transport of p53, thereby preventing the p53-Gadd45A interaction and resulting in inactivation of p53. Our studies demonstrated the significant role of METTL3 mediated exosomal mortalin in malignant transformation and cellular senescence suppression of CCa. Exosomal mortalin could clinically serve as a potential early-diagnosis biomarker and therapeutic target for CCa given its abundance and propensity to be found.

The inhibition of YTHDF3/m6A/LRP6 reprograms fatty acid metabolism and suppresses lymph node metastasis in cervical cancer.

The lipid synthesis of fatty acid (FA) represents a significant hallmark in the occurrence and progression of malignant tumor, which are associated with lymph node (LN) metastasis. Elucidation of the molecular mechanisms underlying LN metastasis could provide therapeutic strategies for cervical cancer (CCa). N6-Methyladenosine (m6A), the most prevalent and abundant RNA modification, exerts specific regulatory control over a series of oncogene expressions. This study demonstrated a clinical correlation between the upregulation of the m6A reader YTHDF3 and LN metastasis, thereby contributing to poor overall survival probability (OS) among CCa patients. The mechanistic investigation revealed that SREBF1 transcriptionally activated YTHDF3 expression by binding to its promoter. Functional experiments demonstrated that the upregulation of YTHDF3 significantly enhanced the in vitro proliferative, migratory, and invasive capacities of CCa cells, while also promoting lymphangiogenesis and facilitating LN metastasis in vivo. Mechanistically, the upregulation of LRP6 through YTHDF3-mediated m6A modification resulted in increased expression of FASN and ACC1, leading to both lipolysis of lipid droplets and synthesis of free fatty acid. Ultimately, this promoted fatty acid metabolism and enhanced LN metastasis by activating the LRP6-YAP-VEGF-C axis, which could induce lymphangiogenesis in CCa. Our study highlighted that YTHDF3 can serve as a promising therapeutic target and predictive biomarker for CCa patients with LN metastasis.

NAT10/ac4C/FOXP1 Promotes Malignant Progression and Facilitates Immunosuppression by Reprogramming Glycolytic Metabolism in Cervical Cancer.

Immunotherapy has recently emerged as the predominant therapeutic approach for cervical cancer (CCa), driven by the groundbreaking clinical achievements of immune checkpoint inhibitors (ICIs), such as anti-PD-1/PD-L1 antibodies. N4-acetylcytidine (ac4C) modification, catalyzed by NAT10, is an important posttranscriptional modification of mRNA in cancers. However, its impact on immunological dysregulation and the tumor immunotherapy response in CCa remains enigmatic. Here, a significant increase in NAT10 expression in CCa tissues is initially observed that is clinically associated with poor prognosis. Subsequently, it is found that HOXC8 activated NAT10 by binding to its promoter, thereby stimulating ac4C modification of FOXP1 mRNA and enhancing its translation efficiency, eventually leading to induction of GLUT4 and KHK expression. Moreover, NAT10/ac4C/FOXP1 axis activity resulted in increased glycolysis and a continuous increase in lactic acid secretion by CCa cells. The lactic acid-enriched tumor microenvironment (TME) further contributed to amplifying the immunosuppressive properties of tumor-infiltrating regulatory T cells (Tregs). Impressively, NAT10 knockdown enhanced the efficacy of PD-L1 blockade-mediated tumor regression in vivo. Taken together, the findings revealed the oncogenic role of NAT10 in initiating crosstalk between cancer cell glycolysis and immunosuppression, which can be a target for synergistic PD-1/PD-L1 blockade immunotherapy in CCa.

Chemically programmed STING-activating nano-liposomal vesicles improve anticancer immunity.

The often immune-suppressive tumor microenvironment (TME) may hinder immune evasion and response to checkpoint blockade therapies. Pharmacological activation of the STING pathway does create an immunologically hot TME, however, systemic delivery might lead to undesired off-target inflammatory responses. Here, we generate a small panel of esterase-activatable pro-drugs based on the structure of the non-nucleotide STING agonist MSA-2 that are subsequently stably incorporated into a liposomal vesicle for intravenous administration. The pharmacokinetic properties and immune stimulatory capacity of pro-drugs delivered via liposomes (SAProsomes) are enhanced compared to the free drug form. By performing efficacy screening among the SAProsomes incorporating different pro-drugs in syngeneic mouse tumor models, we find that superior therapeutic performance relies on improved delivery to the desired tumor and lymphoid compartments. The best candidate, SAProsome-3, highly stimulates secretion of inflammatory cytokines and creates a tumoricidal immune landscape. Notably, upon application to breast cancer or melanoma mouse models, SAProsome-3 elicits durable remission of established tumors and postsurgical tumor-free survival while decreasing metastatic burden without significant systemic toxicity. In summary, our work establishes the proof of principle for a better targeted and more efficient and safe STING agonist therapy.

Long-term variation in nutrients in the South Yellow Sea in response to anthropogenic inputs.

Based on historical data from 1976 to 2019, the effects of anthropogenic activities on long-term changes in nutrients and their ecological effects in the South Yellow Sea were investigated. The dissolved inorganic nitrogen (DIN) concentrations increased continuously from 1990 until the mid-2000s, followed by a shift from an upward trend to a downward trend. The phosphate (PO4-P) and silicate (SiO3-Si) concentrations also showed obvious interannual variations throughout the study period. The concentrations of DIN, PO4-P and SiO3-Si have decreased significantly in recent decade and more. These changes mainly resulted from the reduction in terrestrial input, while the main reason for the decrease in DIN and PO4-P concentrations is the reduction in anthropogenic input. The long-term nutrient changes in the South Yellow Sea have potential ecological impacts on green tide features.

High internal phase Pickering emulsions stabilised by ultrasound-induced soy protein-ß-glucan-catechin complex nanoparticles to enhance the stability and bioaccessibility of curcumin.

AIMS: To evaluate the potential applications of soy protein-glucan-catechin (SGC) complexes prepared with different ultrasound times in stabilising high internal phase Pickering emulsion (HIPPE) and delivering curcumin. METHODS: The SGC complexes were characterised by particle size, morphology, zeta potential, Fourier transform infra-red, and fluorescence spectroscopy. Formation and stability of curcumin emulsions were monitored by droplet size, microstructure, rheological property, lipid oxidation, and in vitro digestion. RESULTS: Short-time ultrasound-induced complexes (SGC-U15) exhibited a small size and wettability of ∼82.5°. The chemical stability and bioaccessibility of curcumin was greatly improved by SGC-U15-stabilised HIPPEs, even after 70 days of storage, heating at 100 °C for 30 min, ultraviolet irradiation for 120 min, and in vitro digestion, owing to the formation of elastic gel-like structure at the oil/water interfaces. CONCLUSION: Our findings may contribute to the design of emulsion-based delivery systems using ultrasound-induced protein-polysaccharide-polyphenol complexes.

Triple-Combination Immunogenic Nanovesicles Reshape the Tumor Microenvironment to Potentiate Chemo-Immunotherapy in Preclinical Cancer Models.

Immune checkpoint blockade (ICB) therapies have had a tremendous impact on cancer therapy. However, most patients harbor a poorly immunogenic tumor microenvironment (TME), presenting overwhelming de novo refractoriness to ICB inhibitors. To address these challenges, combinatorial regimens that employ chemotherapies and immunostimulatory agents are urgently needed. Here, a combination chemoimmunotherapeutic nanosystem consisting of a polymeric monoconjugated gemcitabine (GEM) prodrug nanoparticle decorated with an anti-programmed cell death-ligand 1 (PD-L1) antibody (αPD-L1) on the surface and a stimulator of interferon genes (STING) agonist encapsulated inside is developed. Treatment with GEM nanoparticles upregulates PD-L1 expression in ICB-refractory tumors, resulting in augmented intratumor drug delivery in vivo and synergistic antitumor efficacy via activation of intratumor CD8+ T cell responses. Integration of a STING agonist into the αPD-L1-decorated GEM nanoparticles further improves response rates by transforming low-immunogenic tumors into inflamed tumors. Systemically administered triple-combination nanovesicles induce robust antitumor immunity, resulting in durable regression of established large tumors and a reduction in the metastatic burden, coincident with immunological memory against tumor rechallenge in multiple murine tumor models. These findings provide a design rationale for synchronizing STING agonists, PD-L1 antibodies, and chemotherapeutic prodrugs to generate a chemoimmunotherapeutic effect in treating ICB-nonresponsive tumors.

Development of rapid and effective risk prediction models for stroke in the Chinese population: a cross-sectional study.

OBJECTIVES: The purpose of this study was to use easily obtained and directly observable clinical features to establish predictive models to identify patients at increased risk of stroke. SETTING AND PARTICIPANTS: A total of 46 240 valid records were obtained from 8 research centres and 14 communities in Jiangxi province, China, between February and September 2018. PRIMARY AND SECONDARY OUTCOME MEASURES: The area under the receiver operating characteristic curve (AUC), sensitivity, specificity and accuracy were calculated to test the performance of the five models (logistic regression (LR), random forest (RF), decision tree (DT), extreme gradient boosting (XGBoost) and gradient boosting DT). The calibration curve was used to show calibration performance. RESULTS: The results indicated that XGBoost (AUC: 0.924, accuracy: 0.873, sensitivity: 0.776, specificity: 0.916) and RF (AUC: 0.924, accuracy: 0.872, sensitivity: 0.778, specificity: 0.913) demonstrated excellent performance in predicting stroke. Physical inactivity, hypertension, meat-based diet and high salt intake were important prediction features of stroke. CONCLUSION: The five machine learning models all had good predictive and discriminatory performance for stroke. The performance of RF and XGBoost was slightly better than that of LR, which was easier to interpret and less prone to overfitting. This work provides a rapid and accurate tool for stroke risk assessment, which can help to improve the efficiency of stroke screening medical services and the management of high-risk groups.

Study on the active ingredients and mechanism of action of Jiaotai Pill in the treatment of type 2 diabetes based on network pharmacology: A review.

To explore the potential active ingredients and related mechanisms of Jiaotai Pill in the treatment of Type 2 diabetes mellitus (T2DM) based on network pharmacology and molecular docking. The main active components of Jiaotai Pills were obtained by TCMSP and BATMAN-TCM database combined with literature mining, and the targets of the active components of Jiaotai Pills were predicted by reverse pharmacophore matching (PharmMapper) method. Verifying and normalizing the obtained action targets by using a Uniprot database. Obtaining T2DM related targets through GeneCards, the online mendelian inheritance in man, DrugBank, PharmGKB and therapeutic target databases, constructing a Venn diagram by using a Venny 2.1 online drawing platform to obtain the intersection action targets of Jiaotai pills and T2DM, and the protein-protein interaction network was constructed by String platform. Bioconductor platform and R language were used to analyze the function of gene ontology and the pathway enrichment of Kyoto Encyclopedia of Genes and Genomes. A total of 21 active components and 262 potential targets of Jiaotai Pill were screened by database analysis and literature mining, including 89 targets related to T2DM. Through gene ontology functional enrichment analysis, 1690 biological process entries, 106 molecular function entries and 78 cellular component entries were obtained. Seven pathways related to T2DM were identified by Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. Jiaotai Pill can achieve the purpose of treating T2DM through multiple active ingredients, multiple disease targets, multiple biological pathways and multiple pathways, which provides a theoretical basis for the clinical treatment of T2DM by Jiaotai Pill.

Thermal Insulation Performance of Aerogel Nano-Porous Materials: Characterization and Test Methods.

Due to the extremely high porosity and extremely low density of nano-porous thermal insulation materials, the characteristic size of the pores inside the materials and the characteristic size of the solid skeleton structure are on the nanometer scale, which leads to the obvious nanoscale effect of the heat transfer law inside the aerogel materials. Therefore, the nanoscale heat transfer characteristics inside the aerogel materials and the existing mathematical models for calculating the thermal conductivity of various heat transfer modes at the nanoscale need to be summarized in detail. Moreover, in order to verify the accuracy of the thermal conductivity calculation model of aerogel nano-porous materials, correct experimental data are required to modify the model. Because the medium is involved in radiation heat transfer, the existing test methods have a large error, which brings great difficulties to the design of nano-porous materials. In this paper, the heat transfer mechanism, characterization methods, and test methods of thermal conductivity of nano-porous materials are summarized and discussed. The main contents of this review are as follows. The first part introduces the structural characteristics and specific application environment of aerogel. In the second part, the characteristics of nanoscale heat transfer of aerogel insulation materials are analyzed. In the third part, the characterization methods of thermal conductivity of aerogel insulation materials are summarized. In the fourth part, the test methods of thermal conductivity of aerogel insulation materials are summarized. The fifth part gives a brief conclusion and prospect.

Nuclear m6A reader YTHDC1 promotes muscle stem cell activation/proliferation by regulating mRNA splicing and nuclear export.

Skeletal muscle stem cells (also known as satellite cells [SCs]) are essential for muscle regeneration and the regenerative activities of SCs are intrinsically governed by gene regulatory mechanisms, but the post-transcriptional regulation in SCs remains largely unknown. N(6)-methyladenosine (m6A) modification of RNAs is the most pervasive and highly conserved RNA modification in eukaryotic cells; it exerts powerful impact on almost all aspects of mRNA processing that is mainly endowed by its binding with m6A reader proteins. In this study, we investigate the previously uncharacterized regulatory roles of YTHDC1, an m6A reader in mouse SCs. Our results demonstrate that YTHDC1 is an essential regulator of SC activation and proliferation upon acute injury-induced muscle regeneration. The induction of YTHDC1 is indispensable for SC activation and proliferation; thus, inducible YTHDC1 depletion almost abolishes SC regenerative capacity. Mechanistically, transcriptome-wide profiling using LACE-seq in both SCs and mouse C2C12 myoblasts identifies m6A-mediated binding targets of YTHDC1. Next, splicing analysis defines splicing mRNA targets of m6A-YTHDC1. Furthermore, nuclear export analysis also leads to the identification of potential mRNA export targets of m6A-YTHDC1 in SCs and C2C12 myoblasts;interestingly, some mRNAs can be regulated at both splicing and export levels. Lastly, we map YTHDC1 interacting protein partners in myoblasts and unveil a myriad of factors governing mRNA splicing, nuclear export, and transcription, among which hnRNPG appears to be a bona fide interacting partner of YTHDC1. Altogether, our findings uncover YTHDC1 as an essential factor controlling SC regenerative ability through multifaceted gene regulatory mechanisms in mouse myoblast cells.

Transcriptome Profiling and Chlorophyll Metabolic Pathway Analysis Reveal the Response of Nitraria tangutorum to Increased Nitrogen.

To identify genes that respond to increased nitrogen and assess the involvement of the chlorophyll metabolic pathway and associated regulatory mechanisms in these responses, Nitraria tangutorum seedlings were subjected to four nitrogen concentrations (N0, N6, N36, and N60: 0, 6, 36, and 60 mmol·L-1 nitrogen, respectively). The N. tangutorum seedling leaf transcriptome was analyzed by high-throughput sequencing (Illumina HiSeq 4000), and 332,420 transcripts and 276,423 unigenes were identified. The numbers of differentially expressed genes (DEGs) were 4052 in N0 vs. N6, 6181 in N0 vs. N36, and 3937 in N0 vs. N60. Comparing N0 and N6, N0 and N36, and N0 and N60, we found 1101, 2222, and 1234 annotated DEGs in 113, 121, and 114 metabolic pathways, respectively, classified in the Kyoto Encyclopedia of Genes and Genomes database. Metabolic pathways with considerable accumulation were involved mainly in anthocyanin biosynthesis, carotenoid biosynthesis, porphyrin and chlorophyll metabolism, flavonoid biosynthesis, and amino acid metabolism. N36 increased δ-amino levulinic acid synthesis and upregulated expression of the magnesium chelatase H subunit, which promoted chlorophyll a synthesis. Hence, N36 stimulated chlorophyll synthesis rather than heme synthesis. These findings enrich our understanding of the N. tangutorum transcriptome and help us to research desert xerophytes' responses to increased nitrogen in the future.