Suppressing hydrogen evolution and promoting dendrite free zinc deposition by fluorinated triazine framework towards robust aqueous zinc ion batteries.

Aqueous zinc-ion batteries (AZIBs) have become a research hotspot, but the inevitable zinc dendrites and parasitic reactions in the zinc anode seriously hinder their further development. In this study, three covalent triazine frameworks (DCPY-CTF, CTF-1 and FCTF) have been synthesized and used as artificial protective coatings, in which the fluorinated triazine framework (FCTF) increases the zinc-philic site, thus better promoting dendritic free zinc deposition and inhibiting hydrogen evolution reactions. Excitingly, both experimental results and theoretical calculations indicate that the FCTF interface adjusts the deposition of Zn2+ along the (002) plane, effectively alleviating the formation of zinc dendrites. As expected, Zn@FCTF symmetric cells exhibit cycling stability of over 4000 h (0.25 mA cm-2), meanwhile Zn@FCTF//NHVO full cells provide a high specific capacity of 280 mAh/g at 1.0 A/g, which are superior to those of bare Zn anode. This work provides new insights for suppressing hydrogen evolution and promoting dendrite-free zinc deposition to construct highly stable and reversible AZIBs.

Integrating amino acids into Bcr-Abl inhibitors: design, synthesis, biological evaluation, and in silico studies.

Bcr-Abl is successfully applied to drug discovery as a CML therapeutic target, but point mutation resistance has become a major challenge in the clinical treatment of CML. Our previous studies have shown that the introduction of amino acids as flexible linkers and heterocyclic structures as HBMs can achieve potent inhibition of Bcr-AblT315I. In continuation of these studies, we further enriched the linker types by developing a library of compounds with tert-leucine or serine as a linker. Biological results showed that these compounds exhibited enhanced inhibition against Bcr-AblWT and Bcr-AblT315I kinases as well as improved antiproliferative activity in leukemia cell assays compared to previously disclosed compounds. In particular, compounds TL8, TL10, BS4, BS10, SR5 and SR11 exhibited potent inhibitory activities against Ba/F3 cells bearing a T315I mutant. Additionally, compounds TL8, BS4 and SR5 effectively induced K562 cell apoptosis, arrested the cell cycle at the S or G2/M phase, and inhibited the phosphorylation of Bcr-Abl and STAT5 in a dose-dependent manner. Docking studies verified the rationality of tert-leucine or serine as a flexible linker and indicated that phenylpyridine with an amide side chain favored the potency of these inhibitors. Moreover, ADME prediction suggested that the tested compounds had a favorable safety profile. Thus, tert-leucine or serine can be used as a promising class of flexible linkers for Bcr-Abl inhibitors with heterocyclic structures as HBMs, and compounds BS4, SR5, and especially TL8, can be used as starting points for further optimization.

Single-Vesicle Electrochemistry Reveals Polysaccharide from Glochidion eriocarpum Champ. Regulates Vesicular Storage and Exocytotic Release of Dopamine.

Polysaccharides, which are well-known natural macromolecules, have been recognized for their protective effects on neurons and their influence on extracellular dopamine levels in the brain. It is crucial to investigate the impact of plant polysaccharides on neurotransmission, particularly regarding the vesicular storage and exocytosis of neurotransmitters. In this study, we demonstrated the possibility of studying how the polysaccharide from Glochidion eriocarpum Champ.(GPS) affects vesicle dopamine content and the dynamics of exocytosis in pheochromocytoma (PC12) cells using single-cell amperometry (SCA) and intracellular vesicle impact electrochemical cytometry (IVIEC). Our results unambiguously demonstrate that GPS effectively enhances vesicular neurotransmitter content and alters the dynamics of exocytosis, favoring a smaller fraction of content released in exocytotic release, thereby inducing the partial release mode. These significant effects are attributed to GPS's efficient elevation of calcium influx, significant alteration in the composition of exocytosis-related membrane lipids, and enhancement of free radical scavenging ability. These findings not only establish GPS as a promising candidate for preventive or therapeutic interventions against neurodegenerative disorders but also reiterate the importance of screening native neurologic drugs with single-vesicle electrochemical approaches, the combination of SCA and IVIEC, from a neurotransmitter-centric perspective.

Structural Regulation Enables High Interfacial Functionality for Ni-Rich Single-Crystalline Cathodes.

Ni-rich single-crystalline layered cathodes have garnered significant attention due to their high energy density and thermal stability. However, they experience severe capacity degradation caused by lattice strain and interfacial side reactions during practical applications. In this study, an effective yttrium modification method is employed to stabilize the structure of Ni-rich single-crystalline LiNi0.83Mn0.05Co0.12O2 (SC-NMC83) to solve these issues. This innovative approach successfully immobilizes oxygen within the material, preventing crack formation while simultaneously broadening the diffusion path of Li+. The yttrium-modified sample (SC-NMC83-Y) exhibits a superior capacity retention compared to the SC-NMC83 sample, with values of 90% and 76.1% after 100 cycles, respectively. This work demonstrates the promising potential of a doping strategy for Ni-rich single-crystalline cathodes and paves a pathway for its practical implementation, such as all-solid-state batteries.

Trans-resveratrol mitigates miR-204-3p mediated progression of allergic rhinitis by regulating the EGLN3/HIF-1α/IL33/ST2 signalling pathway.

BACKGROUND: Allergic rhinitis (AR) is a multifactorial disease triggered by interactions between genes and the environment. Clinical evidence has shown that trans-resveratrol, a widely used drug, significantly ameliorates AR pathology. However, the precise mechanisms underlying this effect remain unclear. PURPOSE: This study aimed to elucidate the pharmacological mechanisms of action of trans-resveratrol in patients with AR who exhibit hypoxic symptoms. This will be achieved through microRNA sequencing and signaling pathway screening combined with basic experiments to determine the effects of Trans-resveratrol intervention in this patient population. METHODS: Network pharmacology was used to determine the therapeutic value of trans-resveratrol in AR. The micro-RNA miR-204-3p was pinpointed by sequencing. Quantitative reverse transcription polymerase chain reaction was used to quantify the expression levels. Haematoxylin and eosin, alcian blue-periodic acid-Schiff, and Masson's trichrome staining were used to assess the effects of hypoxia on nasal mucosa immunohistochemistry and immunofluorescence-localised target proteins. Egl nine homolog 3 (EGLN3) was screened using bioinformatics software. Protein expression was detected by western blotting. Cell growth and death were gauged via Cell Counting Kit-8 and terminal deoxynucleotidyl transferase dUTP nick end labelling staining, respectively. Cell migration was observed using a transwell assay. Enzyme-linked immunosorbent assay was used to measure interleukin (IL)33 levels in the cell supernatants. Flow cytometry was used to verify cell cycle and antigen levels. Electron microscopy was used to visualise the status of the nasal mucosa prior to in vivo expression analysis. RESULTS: Patients with hypoxic AR demonstrated more pronounced nasal mucosal remodelling than that in patients with common AR. Sequencing results indicated that these patients had a reduced expression of miR-204-3p. Through a combination utilizing of bioinformatics analysis and experimental validation, EGLN3 has been identified as a direct target of HIF-1α. The low expression level of miR-204-3p represses EGLN3, resulting in the accumulation of HIF-1α and the activation of the IL33/ST2 signaling pathway. These stimulate the proliferation, survival, and migration of HNEpCs, ultimately contributing to mucosa remodeling and AR progression. Trans-resveratrol notably downregulated the levels of HIF-1α and IL33/ST2, while simultaneously increasing the expression of EGLN3. CONCLUSIONS: Downregulation of miR-204-3p initiated a vicious cycle of hypoxic AR via EGLN3/HIF-1α/IL33/ST2. Trans-resveratrol reversed the pathological process of nasal mucosa remodeling of hypoxic AR by exhibiting anti-inflammatory and anti-angiogenic functions via the above signaling pathway. Our study uncovers the underlying mechanism by which hypoxia drives the progression of AR. It presents innovative strategies for addressing inflammatory and hypoxia-related diseases, bridging traditional and modern medicine, and highlighting the potential of natural compounds in clinical practice.

Beautoide A, an Anti-Osteoclastogenic Steroid from Beauveria sp. NBUF147 Associated with an Irciniidae Sponge from the Marine Mesophotic Zone.

Mesophotic coral ecosystems (MCEs), located at depths ranging from 30-150 m, host some of the most diverse yet least explored marine bioresources, particularly significant for the discovery of new bioactive molecules. The fungus Beauveria sp. NBUF147, associated with an Irciniidae sponge from the mesophotic zone at a depth of 82 m, underwent chemical investigation that led to the identification of one new sterol, beautoide A (1), and one reported sterol, 3ß,5α,9α-trihydroxy-(22E,24R)-ergosta-7,22-dien-6-one (2). Their structures were determined from analysis of spectroscopic data and X-ray crystallography. Evaluation of biological activity in prednisolone-induced osteoporotic zebrafish showed that 1 was anti-osteoclastogenic in vivo at 3.0 µM.

PTBP1 knockdown impairs autophagy flux and inhibits gastric cancer progression through TXNIP-mediated oxidative stress.

BACKGROUND: Gastric cancer (GC) is a prevalent malignant tumor, and the RNA-binding protein polypyrimidine tract-binding protein 1 (PTBP1) has been identified as a crucial factor in various tumor types. Moreover, abnormal autophagy levels have been shown to significantly impact tumorigenesis and progression. Despite this, the precise regulatory mechanism of PTBP1 in autophagy regulation in GC remains poorly understood. METHODS: To assess the expression of PTBP1 in GC, we employed a comprehensive approach utilizing western blot, real-time quantitative polymerase chain reaction (RT-qPCR), and bioinformatics analysis. To further identify the downstream target genes that bind to PTBP1 in GC cells, we utilized RNA immunoprecipitation coupled with sequencing (si-PTBP1 RNA-seq). To evaluate the impact of PTBP1 on gastric carcinogenesis, we conducted CCK-8 assays, colony formation assays, and GC xenograft mouse model assays. Additionally, we utilized a transmission electron microscope, immunofluorescence, flow cytometry, western blot, RT-qPCR, and GC xenograft mouse model experiments to elucidate the specific mechanism underlying PTBP1's regulation of autophagy in GC. RESULTS: Our findings indicated that PTBP1 was significantly overexpressed in GC tissues compared with adjacent normal tissues. Silencing PTBP1 resulted in abnormal accumulation of autophagosomes, thereby inhibiting GC cell viability both in vitro and in vivo. Mechanistically, interference with PTBP1 promoted the stability of thioredoxin-interacting protein (TXNIP) mRNA, leading to increased TXNIP-mediated oxidative stress. Consequently, this impaired lysosomal function, ultimately resulting in blockage of autophagic flux. Furthermore, our results suggested that interference with PTBP1 enhanced the antitumor effects of chloroquine, both in vitro and in vivo. CONCLUSION: PTBP1 knockdown impairs GC progression by directly binding to TXNIP mRNA and promoting its expression. Based on these results, PTBP1 emerges as a promising therapeutic target for GC.

An end-to-end deep learning method for mass spectrometry data analysis to reveal disease-specific metabolic profiles.

Untargeted metabolomic analysis using mass spectrometry provides comprehensive metabolic profiling, but its medical application faces challenges of complex data processing, high inter-batch variability, and unidentified metabolites. Here, we present DeepMSProfiler, an explainable deep-learning-based method, enabling end-to-end analysis on raw metabolic signals with output of high accuracy and reliability. Using cross-hospital 859 human serum samples from lung adenocarcinoma, benign lung nodules, and healthy individuals, DeepMSProfiler successfully differentiates the metabolomic profiles of different groups (AUC 0.99) and detects early-stage lung adenocarcinoma (accuracy 0.961). Model flow and ablation experiments demonstrate that DeepMSProfiler overcomes inter-hospital variability and effects of unknown metabolites signals. Our ensemble strategy removes background-category phenomena in multi-classification deep-learning models, and the novel interpretability enables direct access to disease-related metabolite-protein networks. Further applying to lipid metabolomic data unveils correlations of important metabolites and proteins. Overall, DeepMSProfiler offers a straightforward and reliable method for disease diagnosis and mechanism discovery, enhancing its broad applicability.

Longitudinal assessment of the progression of severe keratoconus based on corneal topography.

We aimed to assess long-term disease progression in patients with severe keratoconus (KC). Clinical records of 125 patients (201 eyes) with severe KC followed-up for > 12 months were retrospectively analyzed. From these, 28 patients (31 eyes) were included. Corneal topography parameters evaluated included thinnest corneal thickness (TCT), maximum keratometry (Kmax), anterior and posterior mean corneal radii of 3 mm (aKM, pKM), steep keratometry, and KC screening indices. All patients wore rigid gas permeable contact lenses (RGPCLs) for an extended period. The median patient age and follow-up period were 20 (interquartile range [IQR] 17-22) years and 25 (15-38) months, respectively. Compared to baseline, the aKM, Kmax, and KC screening indices on the anterior corneal surface were reduced at the final follow-up (P < 0.05). No changes were observed in RGP-corrected visual acuity, TCT, pKM, or KC screening indices on the posterior corneal surface. The higher the baseline value, the greater the reduction in aKM and Kmax. Five patients (16%) experienced disease progression during follow-up. Patients with severe KC showed reduced anterior corneal surface curvature and no change in corneal thickness during an average follow-up period of 2-3 years while wearing RGPCLs.

Discovery of novel penetrating peptides able to target human leukemia and lymphoma for enhanced PROTAC delivery.

Proteolysis targeting chimeras (PROTAC) are bifunctional chimeric molecules capable of directly degrading binding proteins through the ubiquitin-proteasome pathway. PROTACs have demonstrated significant potential in overcoming drug resistance and targeting previously untreatable targets. However, several limitations still need to be addressed, including their high molecular weight resulting in poor membrane permeability and bioavailability. In this study, we proposed that cancer-targeted penetrating peptides could enhance the cell permeability of PROTACs. We developed 26 novel targeted penetrating peptides for leukemia and lymphoma cells, among which C9C-f(3Bta) and Cyclo-C9C-R exhibited superior membrane permeability, targetability, and stability. By combining C9C-f(3Bta) and Cyclo-C9C-R with IMA-PROTAC, we effectively enhanced the anti-proliferative activity of IMA-PROTAC, facilitated degradation of Bcr-Abl protein in K562 cells, and reduced downstream STAT5 phosphorylation. Furthermore, the combined application promoted cell apoptosis while blocking G1 phase progression. HPLC-MRM-MS revealed that the combination of C9C-f(3Bta) or Cyclo-C9C-R with IMA-PROTAC significantly enhanced intracellular IMA-PROTAC content. In summary, our proof-of-concept study validated the hypothesis that combining PROTACs with targeted penetrating peptides can improve protein degradation efficiency as well as anti-proliferative capabilities.

A Novel Cellular Senescence-related lncRNA Signature for Predicting the Prognosis of Breast Cancer Patients.

Background: Long non-coding RNA (lncRNA), a crucial regulator in breast cancer (BC) development, is intricately linked with cellular senescence. However, there is a lack of cellular senescence-related lncRNAs (CSRLs) signature to evaluate the prognosis of BC patients. Methods: Correlation analysis was conducted to identify lncRNAs associated with cellular senescence. Subsequently, a CSRL signature was crafted in the training cohort. The model's accuracy was evaluated through survival analysis and receiver operating characteristic curves. Furthermore, prognostic nomograms amalgamating cellular senescence and clinical characteristics were devised. Tumor microenvironment and checkpoint disparities were compared between low-risk and high-risk groups. The correlation between these signatures and treatment response in BC patients was also investigated. Finally, functional experiments were conducted for validation. Results: A signature comprising nine CSRLs was devised, which demonstrated adept prognostic capability in BC patients. Functional enrichment analysis revealed that tumor and immune-related pathways were predominantly enriched. Compared to the low-risk group, the high-risk group could benefit more from immunotherapy and certain chemotherapeutic agents. The expression of the 9 CSRLs was validated through in vitro experiments in different subtypes of BC cell lines and tissues. AC098484.1 was specifically verified for its association with senescence-associated secretory phenotypes. Conclusion: The CSRLs signature emerges as a promising prognostic biomarker for BC, with implications for immunological studies and treatment strategies. AC098484.1 has potential relevance in the treatment of BC cell senescence, and these findings improve the clinical treatment levels for BC patients.

[Nursing Experience Applying Transition Theory to Assist the Family of an Infant With Complex Congenital Gastroschisis].

This article describes the application of transition theory to assist a family with an infant with congenital complex gastroschisis. The nursing period, from March 3, 2023 to May 9, 2023, encompassed care from hospitalization to discharge. The author employed transition theory as a guide and used physical assessments, observations, and interviews for data collection as well as behavioral processes records. The primary nursing problem was identified as "preparation for family operation process enhancement/child's congenital disease and complex care needs, and the family's response to the challenges of the disease and care adaptation." The three phases of nursing care were summarized as: (1) the family adjustment to uncertainty, (2) undertaking caregiving roles and responsibilities, and (3) role development and family reconnection. The author established specific goals for each phase and provided corresponding interventions for the family. In the first phase, the author guided the family in expressing their concerns, and offered personalized health education information as well as psychological support to help them understand the progression of their child's disease and alleviate related anxiety and confusion. In the second phase, the author offered sleep guidance and customized home care schedules to support coping skill development and role functioning. In the third phase, the family was encouraged to explore the meaning of life while accompanying their child's growth in order to achieve spiritual growth and deepen the reconnection within the family. Ultimately, the family strengthened their confidence and capabilities in caregiving and embraced optimism and expectations for the future, enabling them to adapt smoothly to life after their child's return home. When families are confronted with their child's diagnosis with a congenital disease, they often find themselves in a state of self-doubt and faced with continuous challenges. Nurses may employ transition theory throughout the nursing process to better understand and address the evolving needs of both children and their families during the transition phase. Furthermore, transition theory may be applied to help nurses better assess, plan, and care for their patients, which can enhance the capabilities of families and facilitate their successful navigation through the challenging transition journey.

A polylysine/hyaluronan-based core-shell nanoparticle triggers drug delivery by ATP/hyaluronidase dual stimuli for inducing apoptosis of breast cancer cells.

The limitations of self-assembled polymeric nanoparticles for cancer therapy, including instability in the bloodstream, non-specific targeting of cancer cells, and unregulated intracellular drug delivery, were effectively addressed by the development of core-shell SNX@PLL-FPBA/mHA NPs. The core was SNX@PLL-FPBA NPs prepared from polylysine conjugated 3-fluoro-4-carboxyphenylboronic acid (PLL-FPBA) self-assembly and SNX encapsulation, while the shell was methacrylate-modified hyaluronic acid (mHA) adhering to the core by electrostatic interactions and subsequently stabilized by photo-crosslinking, without the use of any organic solvent. SNX@PLL-FPBA/mHA NPs exhibited good stability in varying ionic strengths (0-0.30 M NaCl), pH levels (6.8 and 7.4), and plasma environments mimicking the blood, ensuring their efficacy in systemic circulation. The drug delivery from the nanoparticles was highly sensitive to ATP/Hyals stimuli (82 % within 48 h), closely mimicking the intracellular environment of breast cancer cells. The nanoparticles demonstrated good hemocompatibility and non-toxicity towards human skin fibroblasts. Efficient internalization of SNX@PLL-FPBA/mHA NPs by MCF-7 and MDA-MB-231 breast cancer cells was observed by CLSM and flow cytometry. The intracellular ATP/Hyals stimuli triggered the rapid drug delivery and induced cellular apoptosis. Thus, SNX@PLL-FPBA/mHA NPs were a promising drug nanocarrier for breast cancer therapy, offering improved stability, targeted delivery, and controlled drug release to enhance treatment outcomes.

Multimodal smart systems reprogramme macrophages and remove urate to treat gouty arthritis.

Gouty arthritis is a chronic and progressive disease characterized by high urate levels in the joints and by an inflammatory immune microenvironment. Clinical data indicate that urate reduction therapy or anti-inflammatory therapy alone often fails to deliver satisfactory outcomes. Here we have developed a smart biomimetic nanosystem featuring a 'shell' composed of a fusion membrane derived from M2 macrophages and exosomes, which encapsulates liposomes loaded with a combination of uricase, platinum-in-hyaluronan/polydopamine nanozyme and resveratrol. The nanosystem targets inflamed joints and promotes the accumulation of anti-inflammatory macrophages locally, while the uricase and the nanozyme reduce the levels of urate within the joints. Additionally, site-directed near-infrared irradiation provides localized mild thermotherapy through the action of platinum and polydopamine, initiating heat-induced tissue repair. Combined use of these components synergistically enhances overall outcomes, resulting in faster recovery of the damaged joint tissue.

Stimuli-responsive polymer-based nanosystems for cardiovascular disease theranostics.

Stimulus-responsive polymers have found widespread use in biomedicine due to their ability to alter their own structure in response to various stimuli, including internal factors such as pH, reactive oxygen species (ROS), and enzymes, as well as external factors like light. In the context of atherosclerotic cardiovascular diseases (CVDs), stimulus-response polymers have been extensively employed for the preparation of smart nanocarriers that can deliver therapeutic and diagnostic drugs specifically to inflammatory lesions. Compared with traditional drug delivery systems, stimulus-responsive nanosystems offer higher sensitivity, greater versatility, wider applicability, and enhanced biosafety. Recent research has made significant contributions towards designing stimulus-responsive polymer nanosystems for CVDs diagnosis and treatment. This review summarizes recent advances in this field by classifying stimulus-responsive polymer nanocarriers according to different responsiveness types and describing numerous stimuli relevant to these materials. Additionally, we discuss various applications of stimulus-responsive polymer nanomaterials in CVDs theranostics. We hope that this review will provide valuable insights into optimizing the design of stimulus-response polymers for accelerating their clinical application in diagnosing and treating CVDs.

Increased Gremlin1 Expression in Pancreatic Ductal Adenocarcinoma Promotes a Fibrogenic Stromal Microenvironment.

OBJECTIVE: The pancreatic ductal adenocarcinoma (PDAC) microenvironment is primarily composed of cancer-associated fibroblasts (CAFs) and immune cells. Gremlin1 (Grem1) is a profibrogenic factor that promotes tumorigenesis in several cancers. However, the role of Grem1 in the PDAC microenvironment is not adequately defined. METHODS: We correlated Grem1 levels with activated stroma and immune cells in human PDAC using The Cancer Genome Atlas (TCGA) RNA-sequencing data and characterized the expression of Grem1 transcripts and isoforms in pancreatic cell lines and PDAC tissues. We assessed the role of Grem1 in the microenvironment by in vitro studies. RESULTS: Grem1 expression is associated with an activated stroma and increased M1 and M2 macrophages. Only full length Grem1 variant 1 and isoform 1 were detectable in human pancreatic cells, and remarkably high levels of Grem1 were observed in pancreatic fibroblasts (P < 0.05). Immunohistochemistry detected Grem1 protein in PDAC tumor cells and stromal cells, which correlated with infiltrating macrophages in PDAC tumors. Grem1 knockdown in CAFs suppressed transforming growth factor (TGF)-ß-induced extracellular matrix proteins (P < 0.05). Grem1 recombinant protein treatment in vitro increased M1 and M2 macrophages (P < 0.05). CONCLUSIONS: Grem1 acts as a profibrogenic factor in the PDAC microenvironment via modulation of fibroblasts and macrophages. Grem1 may have the potential to be developed as a therapeutic target for PDAC.

Tryptophan deficiency induced by indoleamine 2,3-dioxygenase 1 results in glucose transporter 1-dependent promotion of aerobic glycolysis in pancreatic cancer.

Indoleamine 2,3-dioxygenase 1 (IDO1), the key enzyme in the catabolism of the essential amino acid tryptophan (Trp) through kynurenine pathway, induces immune tolerance and is considered as a critical immune checkpoint, but its impacts as a metabolism enzyme on glucose and lipid metabolism are overlooked. We aim to clarify the potential role of IDO1 in aerobic glycolysis in pancreatic cancer (PC). Analysis of database revealed the positive correlation in PC between the expressions of IDO1 and genes encoding important glycolytic enzyme hexokinase 2 (HK2), pyruvate kinase (PK), lactate dehydrogenase A (LDHA) and glucose transporter 1 (GLUT1). It was found that IDO1 could modulate glycolysis and glucose uptake in PC cells, Trp deficiency caused by IDO1 overexpression enhanced glucose uptake by stimulating GLUT1 translocation to the plasma membrane of PC cells. Besides, Trp deficiency caused by IDO1 overexpression suppressed the apoptosis of PC cells via promoting glycolysis, which reveals the presence of IDO1-glycolysis-apoptosis axis in PC. IDO1 inhibitors could inhibit glycolysis, promote apoptosis, and exhibit robust therapeutic efficacy when combined with GLUT1 inhibitor in PC mice. Our study reveals the function of IDO1 in the glucose metabolism of PC and provides new insights into the therapeutic strategy for PC.

Molecular Insights into the Effects of F16L and F19L Substitutions on the Conformation and Aggregation Dynamics of Human Calcitonin.

Human calcitonin (hCT) regulates calcium-phosphorus metabolism, but its amyloid aggregation disrupts physiological activity, increases thyroid carcinoma risk, and hampers its clinical use for bone-related diseases like osteoporosis and Paget's disease. Improving hCT with targeted modifications to mitigate amyloid formation while maintaining its function holds promise as a strategy. Understanding how each residue in hCT's amyloidogenic core affects its structure and aggregation dynamics is crucial for designing effective analogues. Mutants F16L-hCT and F19L-hCT, where Phe residues in the core are replaced with Leu as in nonamyloidogenic salmon calcitonin, showed different aggregation kinetics. However, the molecular effects of these substitutions in hCT are still unclear. Here, we systematically investigated the folding and self-assembly conformational dynamics of hCT, F16L-hCT, and F19L-hCT through multiple long-time scale independent atomistic discrete molecular dynamics (DMD) simulations. Our results indicated that the hCT monomer primarily assumed unstructured conformations with dynamic helices around residues 4-12 and 14-21. During self-assembly, the amyloidogenic core of hCT14-21 converted from dynamic helices to ß-sheets. However, substituting F16L did not induce significant conformational changes, as F16L-hCT exhibited characteristics similar to those of wild-type hCT in both monomeric and oligomeric states. In contrast, F19L-hCT exhibited substantially more helices and fewer ß-sheets than did hCT, irrespective of their monomers or oligomers. The substitution of F19L significantly enhanced the stability of the helical conformation for hCT14-21, thereby suppressing the helix-to-ß-sheet conformational conversion. Overall, our findings elucidate the molecular mechanisms underlying hCT aggregation and the effects of F16L and F19L substitutions on the conformational dynamics of hCT, highlighting the critical role of F19 as an important target in the design of amyloid-resistant hCT analogs for future clinical applications.

A novel protein FNDC3B-267aa encoded by circ0003692 inhibits gastric cancer metastasis via promoting proteasomal degradation of c-Myc.

BACKGROUND: Gastric cancer (GC) ranks fifth in global cancer incidence and third in mortality rate among all cancer types. Circular RNAs (circRNAs) have been extensively demonstrated to regulate multiple malignant biological behaviors in GC. Emerging evidence suggests that several circRNAs derived from FNDC3B play pivotal roles in cancer. However, the role of circFNDC3B in GC remains elusive. METHODS: We initially screened circFNDC3B with translation potential via bioinformatics algorithm prediction. Subsequently, Sanger sequencing, qRT-PCR, RNase R, RNA-FISH and nuclear-cytoplasmic fractionation assays were explored to assess the identification and localization of circ0003692, a circRNA derived from FNDC3B. qRT-PCR and ISH were performed to quantify expression of circ0003692 in human GC tissues and adjacent normal tissues. The protein-encoding ability of circ0003692 was investigated through dual-luciferase reporter assay and LC/MS. The biological behavior of circ0003692 in GC was confirmed via in vivo and in vitro experiments. Additionally, Co-IP and rescue experiments were performed to elucidate the interaction between the encoded protein and c-Myc. RESULTS: We found that circ0003692 was significantly downregulated in GC tissues. Circ0003692 had the potential to encode a novel protein FNDC3B-267aa, which was downregulated in GC cells. We verified that FNDC3B-267aa, rather than circ0003692, inhibited GC migration in vitro and in vivo. Mechanistically, FNDC3B-267aa directly interacted with c-Myc and promoted proteasomal degradation of c-Myc, resulting in the downregulation of c-Myc-Snail/Slug axis. CONCLUSIONS: Our study revealed that the novel protein FNDC3B-267aa encoded by circ0003692 suppressed GC metastasis through binding to c-Myc and enhancing proteasome-mediated degradation of c-Myc. The study offers the potential applications of circ0003692 or FNDC3B-267aa as therapeutic targets for GC.

CLK2 mediates IκBα-independent early termination of NF-κB activation by inducing cytoplasmic redistribution and degradation.

Activation of the NF-κB pathway is strictly regulated to prevent excessive inflammatory and immune responses. In a well-known negative feedback model, IκBα-dependent NF-κB termination is a delayed response pattern in the later stage of activation, and the mechanisms mediating the rapid termination of active NF-κB remain unclear. Here, we showed IκBα-independent rapid termination of nuclear NF-κB mediated by CLK2, which negatively regulated active NF-κB by phosphorylating the RelA/p65 subunit of NF-κB at Ser180 in the nucleus to limit its transcriptional activation through degradation and nuclear export. Depletion of CLK2 increased the production of inflammatory cytokines, reduced viral replication and increased the survival of the mice. Mechanistically, CLK2 phosphorylated RelA/p65 at Ser180 in the nucleus, leading to ubiquitin‒proteasome-mediated degradation and cytoplasmic redistribution. Importantly, a CLK2 inhibitor promoted cytokine production, reduced viral replication, and accelerated murine psoriasis. This study revealed an IκBα-independent mechanism of early-stage termination of NF-κB in which phosphorylated Ser180 RelA/p65 turned off posttranslational modifications associated with transcriptional activation, ultimately resulting in the degradation and nuclear export of RelA/p65 to inhibit excessive inflammatory activation. Our findings showed that the phosphorylation of RelA/p65 at Ser180 in the nucleus inhibits early-stage NF-κB activation, thereby mediating the negative regulation of NF-κB.