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1.
Cell ; 166(3): 567-581, 2016 Jul 28.
Article in English | MEDLINE | ID: mdl-27374329

ABSTRACT

Insulin signaling regulates many facets of animal physiology. Its dysregulation causes diabetes and other metabolic disorders. The spindle checkpoint proteins MAD2 and BUBR1 prevent precocious chromosome segregation and suppress aneuploidy. The MAD2 inhibitory protein p31(comet) promotes checkpoint inactivation and timely chromosome segregation. Here, we show that whole-body p31(comet) knockout mice die soon after birth and have reduced hepatic glycogen. Liver-specific ablation of p31(comet) causes insulin resistance, hyperinsulinemia, glucose intolerance, and hyperglycemia and diminishes the plasma membrane localization of the insulin receptor (IR) in hepatocytes. MAD2 directly binds to IR and facilitates BUBR1-dependent recruitment of the clathrin adaptor AP2 to IR. p31(comet) blocks the MAD2-BUBR1 interaction and prevents spontaneous clathrin-mediated IR endocytosis. BUBR1 deficiency enhances insulin sensitivity in mice. BUBR1 depletion in hepatocytes or the expression of MAD2-binding-deficient IR suppresses the metabolic phenotypes of p31(comet) ablation. Our findings establish a major IR regulatory mechanism and link guardians of chromosome stability to nutrient metabolism.


Subject(s)
Cell Cycle Checkpoints , Insulin/metabolism , Mitosis , Signal Transduction , Adaptor Protein Complex 2/metabolism , Adaptor Proteins, Signal Transducing , Aneuploidy , Animals , Cell Cycle Proteins/metabolism , Cells, Cultured , Chromosome Segregation , Clathrin/metabolism , Endocytosis , Hep G2 Cells , Homeostasis , Humans , Insulin Resistance , Liver/metabolism , Mad2 Proteins/metabolism , Mice , Mice, Knockout , Nuclear Proteins , Protein Serine-Threonine Kinases/metabolism , Receptor, Insulin/metabolism
2.
Cell ; 164(1-2): 69-80, 2016 Jan 14.
Article in English | MEDLINE | ID: mdl-26724866

ABSTRACT

Long noncoding RNAs (lncRNAs) have emerged as regulators of diverse biological processes. Here, we describe the initial functional analysis of a poorly characterized human lncRNA (LINC00657) that is induced after DNA damage, which we termed "noncoding RNA activated by DNA damage", or NORAD. NORAD is highly conserved and abundant, with expression levels of approximately 500-1,000 copies per cell. Remarkably, inactivation of NORAD triggers dramatic aneuploidy in previously karyotypically stable cell lines. NORAD maintains genomic stability by sequestering PUMILIO proteins, which repress the stability and translation of mRNAs to which they bind. In the absence of NORAD, PUMILIO proteins drive chromosomal instability by hyperactively repressing mitotic, DNA repair, and DNA replication factors. These findings introduce a mechanism that regulates the activity of a deeply conserved and highly dosage-sensitive family of RNA binding proteins and reveal unanticipated roles for a lncRNA and PUMILIO proteins in the maintenance of genomic stability.


Subject(s)
Genomic Instability , RNA, Long Noncoding/metabolism , RNA-Binding Proteins/metabolism , Animals , Base Sequence , Chromosomal Instability , HCT116 Cells , Humans , Mice , Ploidies , RNA, Long Noncoding/chemistry , RNA, Long Noncoding/genetics
3.
Mol Cell ; 83(16): 2856-2871.e8, 2023 08 17.
Article in English | MEDLINE | ID: mdl-37536339

ABSTRACT

Cohesin and CCCTC-binding factor (CTCF) are key regulatory proteins of three-dimensional (3D) genome organization. Cohesin extrudes DNA loops that are anchored by CTCF in a polar orientation. Here, we present direct evidence that CTCF binding polarity controls cohesin-mediated DNA looping. Using single-molecule imaging, we demonstrate that a critical N-terminal motif of CTCF blocks cohesin translocation and DNA looping. The cryo-EM structure of the cohesin-CTCF complex reveals that this CTCF motif ahead of zinc fingers can only reach its binding site on the STAG1 cohesin subunit when the N terminus of CTCF faces cohesin. Remarkably, a C-terminally oriented CTCF accelerates DNA compaction by cohesin. DNA-bound Cas9 and Cas12a ribonucleoproteins are also polar cohesin barriers, indicating that stalling may be intrinsic to cohesin itself. Finally, we show that RNA-DNA hybrids (R-loops) block cohesin-mediated DNA compaction in vitro and are enriched with cohesin subunits in vivo, likely forming TAD boundaries.


Subject(s)
Chromatin , R-Loop Structures , CCCTC-Binding Factor/genetics , CCCTC-Binding Factor/metabolism , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , DNA/genetics , DNA/metabolism , Cohesins
4.
Nature ; 584(7820): 304-309, 2020 08.
Article in English | MEDLINE | ID: mdl-32581365

ABSTRACT

The human GABAB receptor-a member of the class C family of G-protein-coupled receptors (GPCRs)-mediates inhibitory neurotransmission and has been implicated in epilepsy, pain and addiction1. A unique GPCR that is known to require heterodimerization for function2-6, the GABAB receptor has two subunits, GABAB1 and GABAB2, that are structurally homologous but perform distinct and complementary functions. GABAB1 recognizes orthosteric ligands7,8, while GABAB2 couples with G proteins9-14. Each subunit is characterized by an extracellular Venus flytrap (VFT) module, a descending peptide linker, a seven-helix transmembrane domain and a cytoplasmic tail15. Although the VFT heterodimer structure has been resolved16, the structure of the full-length receptor and its transmembrane signalling mechanism remain unknown. Here we present a near full-length structure of the GABAB receptor, captured in an inactive state by cryo-electron microscopy. Our structure reveals several ligands that preassociate with the receptor, including two large endogenous phospholipids that are embedded within the transmembrane domains to maintain receptor integrity and modulate receptor function. We also identify a previously unknown heterodimer interface between transmembrane helices 3 and 5 of both subunits, which serves as a signature of the inactive conformation. A unique 'intersubunit latch' within this transmembrane interface maintains the inactive state, and its disruption leads to constitutive receptor activity.


Subject(s)
Cryoelectron Microscopy , Receptors, GABA-B/chemistry , Receptors, GABA-B/ultrastructure , Calcium/metabolism , Ethanolamines/chemistry , Ethanolamines/metabolism , Humans , Ligands , Models, Molecular , Phosphorylcholine/chemistry , Phosphorylcholine/metabolism , Protein Domains , Protein Multimerization , Protein Subunits/chemistry , Protein Subunits/metabolism , Receptors, GABA-B/metabolism , Structure-Activity Relationship
6.
Mol Cell ; 70(3): 395-407.e4, 2018 05 03.
Article in English | MEDLINE | ID: mdl-29727616

ABSTRACT

Telomeres and telomere-binding proteins form complex secondary nucleoprotein structures that are critical for genome integrity but can present serious challenges during telomere DNA replication. It remains unclear how telomere replication stress is resolved during S phase. Here, we show that the BUB3-BUB1 complex, a component in spindle assembly checkpoint, binds to telomeres during S phase and promotes telomere DNA replication. Loss of the BUB3-BUB1 complex results in telomere replication defects, including fragile and shortened telomeres. We also demonstrate that the telomere-binding ability of BUB3 and kinase activity of BUB1 are indispensable to BUB3-BUB1 function at telomeres. TRF2 targets BUB1-BUB3 to telomeres, and BUB1 can directly phosphorylate TRF1 and promote TRF1 recruitment of BLM helicase to overcome replication stress. Our findings have uncovered previously unknown roles for the BUB3-BUB1 complex in S phase and shed light on how proteins from diverse pathways function coordinately to ensure proper telomere replication and maintenance.


Subject(s)
Cell Cycle Proteins/genetics , DNA Replication/genetics , Poly-ADP-Ribose Binding Proteins/genetics , Protein Serine-Threonine Kinases/genetics , Telomere/genetics , Cell Line , Cell Line, Tumor , DNA Helicases/genetics , HEK293 Cells , HeLa Cells , Humans , M Phase Cell Cycle Checkpoints/genetics , S Phase/genetics , Spindle Apparatus/genetics , Telomere-Binding Proteins/genetics
7.
Mol Cell ; 70(6): 1134-1148.e7, 2018 06 21.
Article in English | MEDLINE | ID: mdl-29932904

ABSTRACT

Cohesin organizes DNA into chromatids, regulates enhancer-promoter interactions, and confers sister chromatid cohesion. Its association with chromosomes is regulated by hook-shaped HEAT repeat proteins that bind Scc1, namely Scc3, Pds5, and Scc2. Unlike Pds5, Scc2 is not a stable cohesin constituent but, as shown here, transiently replaces Pds5. Scc1 mutations that compromise its interaction with Scc2 adversely affect cohesin's ATPase activity and loading. Moreover, Scc2 mutations that alter how the ATPase responds to DNA abolish loading despite cohesin's initial association with loading sites. Lastly, Scc2 mutations that permit loading in the absence of Scc4 increase Scc2's association with chromosomal cohesin and reduce that of Pds5. We suggest that cohesin switches between two states: one with Pds5 bound that is unable to hydrolyze ATP efficiently but is capable of release from chromosomes and another in which Scc2 replaces Pds5 and stimulates ATP hydrolysis necessary for loading and translocation from loading sites.


Subject(s)
Adenosine Triphosphatases/metabolism , Cell Cycle Proteins/metabolism , Chromosomal Proteins, Non-Histone/metabolism , Saccharomyces cerevisiae Proteins/metabolism , Adenosine Triphosphatases/genetics , Cell Cycle Proteins/genetics , Chromatids/genetics , Chromatids/metabolism , Chromosomal Proteins, Non-Histone/genetics , Chromosome Segregation , DNA, Fungal/metabolism , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Saccharomyces cerevisiae Proteins/genetics , Cohesins
8.
Proc Natl Acad Sci U S A ; 120(19): e2219098120, 2023 May 09.
Article in English | MEDLINE | ID: mdl-37126725

ABSTRACT

Graphene oxide (GO) membranes with nanoconfined interlayer channels theoretically enable anomalous nanofluid transport for ultrahigh filtration performance. However, it is still a significant challenge for current GO laminar membranes to achieve ultrafast water permeation and high ion rejection simultaneously, because of the contradictory effect that exists between the water-membrane hydrogen-bond interaction and the ion-membrane electrostatic interaction. Here, we report a vertically aligned reduced GO (VARGO) membrane and propose an electropolarization strategy for regulating the interfacial hydrogen-bond and electrostatic interactions to concurrently enhance water permeation and ion rejection. The membrane with an electro-assistance of 2.5 V exhibited an ultrahigh water permeance of 684.9 L m-2 h-1 bar-1, which is 1-2 orders of magnitude higher than those of reported GO-based laminar membranes. Meanwhile, the rejection rate of the membrane for NaCl was as high as 88.7%, outperforming most reported graphene-based membranes (typically 10 to 50%). Molecular dynamics simulations and density-function theory calculations revealed that the electropolarized VARGO nanochannels induced the well-ordered arrangement of nanoconfined water molecules, increasing the water transport efficiency, and thereby resulting in improved water permeation. Moreover, the electropolarization effect enhanced the surface electron density of the VARGO nanochannels and reinforced the interfacial attractive interactions between the cations in water and the oxygen groups and π-electrons on the VARGO surface, strengthening the ion-partitioning and Donnan effect for the electrostatic exclusion of ions. This finding offers an electroregulation strategy for membranes to achieve both high water permeability and high ion rejection performance.

9.
Mol Cell Proteomics ; 22(4): 100524, 2023 04.
Article in English | MEDLINE | ID: mdl-36870568

ABSTRACT

The heterogeneity of idiopathic pulmonary fibrosis (IPF) limits its diagnosis and treatment. The association between the pathophysiological features and the serum protein signatures of IPF currently remains unclear. The present study analyzed the specific proteins and patterns associated with the clinical parameters of IPF based on a serum proteomic dataset by data-independent acquisition using MS. Differentiated proteins in sera distinguished patients with IPF into three subgroups in signal pathways and overall survival. Aging-associated signatures by weighted gene correlation network analysis coincidently provided clear and direct evidence that aging is a critical risk factor for IPF rather than a single biomarker. Expression of LDHA and CCT6A, which was associated with glucose metabolic reprogramming, was correlated with high serum lactic acid content in patients with IPF. Cross-model analysis and machine learning showed that a combinatorial biomarker accurately distinguished patients with IPF from healthy individuals with an area under the curve of 0.848 (95% CI = 0.684-0.941) and validated from another cohort and ELISA assay. This serum proteomic profile provides rigorous evidence that enables an understanding of the heterogeneity of IPF and protein alterations that could help in its diagnosis and treatment decisions.


Subject(s)
Idiopathic Pulmonary Fibrosis , Proteomics , Humans , Idiopathic Pulmonary Fibrosis/diagnosis , Idiopathic Pulmonary Fibrosis/metabolism , Idiopathic Pulmonary Fibrosis/pathology , Blood Proteins , Biomarkers , Chaperonin Containing TCP-1
10.
Nano Lett ; 24(9): 2876-2884, 2024 Mar 06.
Article in English | MEDLINE | ID: mdl-38385324

ABSTRACT

Upconversion (UC)/downconversion (DC)-luminescent lanthanide-doped nanocrystals (LDNCs) with near-infrared (NIR, 650-1700 nm) excitation have been gaining increasing popularity in bioimaging. However, conventional NIR-excited LDNCs cannot be degraded and eliminated eventually in vivo owing to intrinsic "rigid" lattices, thus constraining clinical applications. A biodegradability-tunable heterogeneous core-shell-shell luminescent LDNC of Na3HfF7:Yb,Er@Na3ZrF7:Yb,Er@CaF2:Yb,Zr (abbreviated as HZC) was developed and modified with oxidized sodium alginate (OSA) for multimode bioimaging. The dynamic "soft" lattice-Na3Hf(Zr)F7 host and the varying Zr4+ doping content in the outmoster CaF2 shell endowed HZC with tunable degradability. Through elaborated core-shell-shell coating, Yb3+/Er3+-coupled UC red and green and DC second near-infrared (NIR-II) emissions were, respectively, enhanced by 31.23-, 150.60-, and 19.42-fold when compared with core nanocrystals. HZC generated computed tomography (CT) imaging contrast effects, thus enabling NIR-II/CT/UC trimodal imaging. OSA modification not only ensured the exemplary biocompatibility of HZC but also enabled tumor-specific diagnosis. The findings would benefit the clinical imaging translation of LDNCs.


Subject(s)
Lanthanoid Series Elements , Nanoparticles , Hafnium , Zirconium , Nanoparticles/chemistry , Tomography, X-Ray Computed
11.
J Biol Chem ; 299(11): 105296, 2023 11.
Article in English | MEDLINE | ID: mdl-37774974

ABSTRACT

3D chromatin organization plays a critical role in regulating gene expression, DNA replication, recombination, and repair. While initially discovered for its role in sister chromatid cohesion, emerging evidence suggests that the cohesin complex (SMC1, SMC3, RAD21, and SA1/SA2), facilitated by NIPBL, mediates topologically associating domains and chromatin loops through DNA loop extrusion. However, information on how conformational changes of cohesin-NIPBL drive its loading onto DNA, initiation, and growth of DNA loops is still lacking. In this study, high-speed atomic force microscopy imaging reveals that cohesin-NIPBL captures DNA through arm extension, assisted by feet (shorter protrusions), and followed by transfer of DNA to its lower compartment (SMC heads, RAD21, SA1, and NIPBL). While binding at the lower compartment, arm extension leads to the capture of a second DNA segment and the initiation of a DNA loop that is independent of ATP hydrolysis. The feet are likely contributed by the C-terminal domains of SA1 and NIPBL and can transiently bind to DNA to facilitate the loading of the cohesin complex onto DNA. Furthermore, high-speed atomic force microscopy imaging reveals distinct forward and reverse DNA loop extrusion steps by cohesin-NIPBL. These results advance our understanding of cohesin by establishing direct experimental evidence for a multistep DNA-binding mechanism mediated by dynamic protein conformational changes.


Subject(s)
Cell Cycle Proteins , Chromosomal Proteins, Non-Histone , Cell Cycle Proteins/metabolism , Chromosomal Proteins, Non-Histone/metabolism , DNA/chemistry , Chromatin , Cohesins
12.
Cancer Sci ; 115(11): 3570-3586, 2024 Nov.
Article in English | MEDLINE | ID: mdl-39222374

ABSTRACT

Clear cell renal cell carcinoma (ccRCC) represents a highly heterogeneous kidney malignancy associated with the poorest prognosis. The metastatic potential of advanced ccRCC tumors is notably high, posing significant clinical challenges. There is an urgent imperative to develop novel therapeutic approaches to address ccRCC metastasis. Recent investigations indicated a potential association between GBP2 and tumor immunity. However, the precise functional role of GBP2 in the progression of ccRCC remains poorly understood. The present study revealed a strong correlation between GBP2 and M2 macrophages. Specifically, our findings demonstrated that the inhibition of GBP2 significantly impedes the migratory and invasive capabilities of ccRCC cells. We observed that the presence of M2 macrophages can reverse the effects of GBP2 knockdown on tumor cell migration and invasion. Mechanistically, we demonstrated that M2 macrophages promote the expression of the GBP2/p-STAT3 and p-ERK axis in tumor cells through the secretion of interleukin-10 (IL-10) and transforming growth factor-ß (TGF-ß), thereby substantially enhancing the migratory and invasive capacities of the tumor cells. Simultaneously, we have identified that GBP2 promotes the polarization of macrophages to the M2 phenotype by stimulating the secretion of interleukin-18 (IL-18). In summary, our investigation anticipates that the GBP2/IL-18/M2 macrophages/IL-10 and the TGF-ß/GBP2, p-STAT3, p-ERK loop plays a crucial role in ccRCC metastasis. The collective findings from our research underscore the significant role of GBP2 in tumor immunity and emphasize the potential for modulating GBP2 as a promising therapeutic strategy for targeting ccRCC metastasis.


Subject(s)
Carcinoma, Renal Cell , Cell Movement , Disease Progression , Kidney Neoplasms , Macrophages , Humans , Carcinoma, Renal Cell/pathology , Carcinoma, Renal Cell/metabolism , Carcinoma, Renal Cell/genetics , Kidney Neoplasms/pathology , Kidney Neoplasms/metabolism , Kidney Neoplasms/genetics , Cell Movement/genetics , Macrophages/metabolism , Macrophages/immunology , Cell Line, Tumor , STAT3 Transcription Factor/metabolism , GTPase-Activating Proteins/metabolism , GTPase-Activating Proteins/genetics , Interleukin-10/metabolism , Neoplasm Invasiveness , Transforming Growth Factor beta/metabolism , Interleukin-18/metabolism , GTP-Binding Proteins/metabolism , GTP-Binding Proteins/genetics , Animals , Mice
13.
Kidney Int ; 2024 Aug 31.
Article in English | MEDLINE | ID: mdl-39218393

ABSTRACT

Cotadutide is a glucagon-like peptide-1 (GLP-1) and glucagon receptor agonist that may improve kidney function in patients with type 2 diabetes (T2D) and chronic kidney disease (CKD). In this phase 2b study, patients with T2D and CKD (estimated glomerular filtration rate [eGFR] of 20 or more and under 90 mL/min per 1.73 m2 and urinary albumin-to-creatinine ratio [UACR] over 50 mg/g) were randomized 1:1:1:1:1 to 26 weeks' treatment with standard of care plus subcutaneous cotadutide uptitrated to 100, 300, or 600 µg, or placebo daily (double-blind), or the GLP-1 agonist semaglutide 1 mg once weekly (open-label).The co-primary endpoints were absolute and percentage change versus placebo in UACR from baseline to the end of week 14. Among 248 randomized patients, mean age 67.1 years, 19% were female, mean eGFR was 55.3 mL/min per 1.73 m2, geometric mean was UACR 205.5 mg/g (coefficient of variation 270.0), and 46.8% were receiving concomitant sodium-glucose co-transporter 2 inhibitors. Cotadutide dose-dependently reduced UACR from baseline to the end of week 14, reaching significance at 300 µg (-43.9% [95% confidence interval -54.7 to -30.6]) and 600 µg (-49.9% [-59.3 to -38.4]) versus placebo; with effects sustained at week 26. Serious adverse events were balanced across arms. Safety and tolerability of cotadutide 600 µg were comparable to semaglutide. Thus, our study shows that in patients with T2D and CKD, cotadutide significantly reduced UACR on top of standard of care with an acceptable tolerability profile, suggesting kidney protective benefits that need confirmation in a larger study.

14.
Plant Biotechnol J ; 22(11): 3085-3098, 2024 Nov.
Article in English | MEDLINE | ID: mdl-39037027

ABSTRACT

As an essential macronutrient, phosphorus (P) is often a limiting nutrient because of its low availability and mobility in soils. Drought is a major environmental stress that reduces crop yield. How plants balance and combine P-starvation responses (PSRs) and drought resistance is unclear. In this study, we identified the transcription factor ZmPHR1 as a major regulator of PSRs that modulates phosphate (Pi) signaling and homeostasis. We found that maize zmphr1 mutants had reduced P concentration and were sensitive to Pi starvation, whereas ZmPHR1-OE lines displayed elevated Pi concentration and yields. In addition, 57% of PSR genes and nearly 70% of ZmPHR1-regulated PSR genes in leaves were transcriptionally responsive to drought. Under moderate and early drought conditions, the Pi concentration of maize decreased, and PSR genes were up-regulated before drought-responsive genes. The ZmPHR1-OE lines exhibited drought-resistant phenotypes and reduced stomatal apertures, whereas the opposite was true of the zmphr1 mutants. ZmPT7-OE lines and zmspx3 mutants, which had elevated Pi concentration, also exhibited drought resistance, but zmpt7 mutants were sensitive to drought. Our results suggest that ZmPHR1 plays a central role in integrating Pi and drought signals and that Pi homeostasis improves the ability of maize to combat drought.


Subject(s)
Droughts , Gene Expression Regulation, Plant , Homeostasis , Phosphates , Plant Proteins , Zea mays , Zea mays/genetics , Zea mays/metabolism , Zea mays/physiology , Phosphates/metabolism , Phosphates/deficiency , Plant Proteins/genetics , Plant Proteins/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Mutation , Stress, Physiological/genetics , Plant Leaves/metabolism , Plant Leaves/genetics , Plant Leaves/physiology , Drought Resistance
15.
PLoS Comput Biol ; 19(11): e1011598, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37956217

ABSTRACT

In contrast to heart failure (HF) with reduced ejection fraction (HFrEF), effective interventions for HF with preserved ejection fraction (HFpEF) have proven elusive, in part because it is a heterogeneous syndrome with incompletely understood pathophysiology. This study utilized mathematical modeling to evaluate mechanisms distinguishing HFpEF and HFrEF. HF was defined as a state of chronically elevated left ventricle end diastolic pressure (LVEDP > 20mmHg). First, using a previously developed cardiorenal model, sensitivities of LVEDP to potential contributing mechanisms of HFpEF, including increased myocardial, arterial, or venous stiffness, slowed ventricular relaxation, reduced LV contractility, hypertension, or reduced venous capacitance, were evaluated. Elevated LV stiffness was identified as the most sensitive factor. Large LV stiffness increases alone, or milder increases combined with either decreased LV contractility, increased arterial stiffness, or hypertension, could increase LVEDP into the HF range without reducing EF. We then evaluated effects of these mechanisms on mechanical signals of cardiac outward remodeling, and tested the ability to maintain stable EF (as opposed to progressive EF decline) under two remodeling assumptions: LV passive stress-driven vs. strain-driven remodeling. While elevated LV stiffness increased LVEDP and LV wall stress, it mitigated wall strain rise for a given LVEDP. This suggests that if LV strain drives outward remodeling, a stiffer myocardium will experience less strain and less outward dilatation when additional factors such as impaired contractility, hypertension, or arterial stiffening exacerbate LVEDP, allowing EF to remain normal even at high filling pressures. Thus, HFpEF heterogeneity may result from a range of different pathologic mechanisms occurring in an already stiffened myocardium. Together, these simulations further support LV stiffening as a critical mechanism contributing to elevated cardiac filling pressures; support LV passive strain as the outward dilatation signal; offer an explanation for HFpEF heterogeneity; and provide a mechanistic explanation distinguishing between HFpEF and HFrEF.


Subject(s)
Heart Failure , Hypertension , Humans , Stroke Volume/physiology , Heart , Myocardium/pathology , Hypertension/complications
16.
Diabetes Obes Metab ; 2024 Nov 04.
Article in English | MEDLINE | ID: mdl-39495140

ABSTRACT

AIMS: GLP-1 receptor agonists (GLP-1 RAs) are proven therapies for type 2 diabetes mellitus (T2DM) and overweight or obesity. We performed non-clinical and first-in-human (FIH) evaluation of ECC5004/AZD5004, an oral small-molecule GLP-1 RA. MATERIALS AND METHODS: ECC5004 was profiled in cell lines overexpressing human GLP-1R, in glucose-stimulated insulin secretion (GSIS) assays in a human ß-cell line and non-human primates (NHPs). To evaluate safety, ECC5004 was orally administered to NHPs for 9 months and a phase I, double-blind, placebo-controlled FIH study was conducted. This study evaluated single doses of ECC5004 (1-300 mg) in healthy volunteers, and multiple daily doses (5, 10, 30 and 50 mg) in patients with T2DM for 28 days. RESULTS: ECC5004 bound to the hGLP-1R (IC50 = 2.4 nM) augmented cAMP signalling without ß-arrestin-2 recruitment or receptor internalization. ECC5004 potentiated GSIS in both EndoC-ßH5 cells (EC50 = 5.9 nM) and in vivo in NHPs (EC50 = 0.022 nM). Dose-dependent body weight changes compared to control were seen in the 9-month NHP toxicity study. In the first-in-human study, ECC5004 was well tolerated with no serious adverse events. Dose-dependent reductions in glucose and body weight were observed with a dose-proportional exposure at doses ≥25 mg. CONCLUSION: ECC5004 engaged the GLP-1R across the therapeutic dose range tested and had a safety and tolerability profile consistent with other GLP-1 RAs, along with a pharmacokinetic profile compatible with once-daily oral dosing. These data support continued development of ECC5004 as a potential therapy for T2DM and overweight or obesity. CLINICAL TRIAL REGISTRATION: NCT05654831.

17.
Br J Clin Pharmacol ; 2024 Aug 25.
Article in English | MEDLINE | ID: mdl-39183511

ABSTRACT

AIMS: This study describes the pharmacokinetic (PK)/target engagement (TE) relationship of tozorakimab, an anti-interleukin (IL)-33 antibody, by building a mechanistic population PK/TE model using phase 1 biomarker data. METHODS: The analysis included tozorakimab PK and TE in serum assessed in 60 tozorakimab-treated participants, including healthy adults and patients with mild chronic obstructive pulmonary disease. Scenarios evaluated three dose frequencies (once every 2, 4 or 6 weeks) administered subcutaneously at seven doses of tozorakimab (30, 60, 90, 120, 150, 300 or 600 mg). For each dose, simulations were performed with 5000 virtual individuals to predict systemic TE. Inhibition of IL-33/soluble ST2 (sST2) complex levels at trough PK at steady state was assessed in each dosing scenario. The PK/TE modelling analyses were performed using a nonlinear mixed-effect modelling approach. RESULTS: The final two-compartment PK model with tozorakimab binding IL-33 in the central compartment adequately described the systemic PK and TE of tozorakimab at population and individual levels. The mean PK parameter estimates of absorption rate, central volume of distribution and clearance were 0.48 (90% confidence interval [CI]: 0.40-0.59, 1/day), 12.64 (90% CI: 8.60-18.62, L) and 0.87 (90% CI: 0.65-1.16, L/day), respectively. Consistent with the observed value, tozorakimab bioavailability was 45%. For all three dose frequencies, predicted inhibition of systemic IL-33/sST2 levels was more than 95% at doses greater than 90 mg. CONCLUSIONS: The PK/TE model reliably quantified the relationship between PK and systemic TE of tozorakimab, with potential utility for predicting clinical dose-response relationships and supporting clinical dose selection.

18.
Environ Sci Technol ; 2024 Sep 17.
Article in English | MEDLINE | ID: mdl-39288224

ABSTRACT

The nonradical oxidation pathway for pollutant degradation in Fenton-like catalysis is favorable for water treatment due to the high reaction rate and superior environmental robustness. However, precise regulation of such reactions is still restricted by our poor knowledge of underlying mechanisms, especially the correlation between metal site conformation of metal atom clusters and pollutant degradation behaviors. Herein, we investigated the electron transfer and pollutant oxidation mechanisms of atomic-level exposed Ag atom clusters (AgAC) loaded on specifically crafted nitrogen-doped porous carbon (NPC). The AgAC triggered a direct electron transfer (DET) between the terminal oxygen (Oα) of surface-activated peroxodisulfate and the electron-donating substituents-containing contaminants (EDTO-DET), rendering it 11-38 times higher degradation rate than the reported carbon-supported metal catalysts system with various single-atom active centers. Heterocyclic substituents and electron-donating groups were more conducive to degradation via the EDTO-DET system, while contaminants with high electron-absorbing capacity preferred the radical pathway. Notably, the system achieved 79.5% chemical oxygen demand (COD) removal for the treatment of actual pharmaceutical wastewater containing 1053 mg/L COD within 30 min. Our study provides valuable new insights into the Fenton-like reactions of metal atom cluster catalysts and lays an important basis for revolutionizing advanced oxidation water purification technologies.

19.
Environ Sci Technol ; 58(31): 14034-14041, 2024 Aug 06.
Article in English | MEDLINE | ID: mdl-39048519

ABSTRACT

For electrochemical application in seawater or brine, continuous scaling on cathodes will form insulation layers, making it nearly impossible to run an electrochemical reaction continuously. Herein, we report our discovery that a cathode consisting of conical nanobundle arrays with hydrophobic surfaces exhibits a unique scaling-free function. The hydrophobic surfaces will be covered with microbubbles created by electrolytic water splitting, which limits scale crystals from standing only on nanotips of conical nanobundles, and the bursting of large bubbles formed by the accumulation of microbubbles will cause a violent disturbance, removing scale crystals automatically from nanotips. Benefiting from the scaling-free properties of the cathode, high-purity nano-CaCO3 (98.9%) and nano-Mg(OH)2 (99.5%) were extracted from seawater. This novel scaling-free cathode is expected to eliminate the inherent limitations of electrochemical technology and open up a new route to seawater mining.


Subject(s)
Calcium Carbonate , Electrodes , Seawater , Seawater/chemistry , Calcium Carbonate/chemistry , Magnesium Hydroxide/chemistry , Electrochemical Techniques
20.
Mol Cell ; 61(4): 489-491, 2016 Feb 18.
Article in English | MEDLINE | ID: mdl-26895420

ABSTRACT

Recent studies, including two in this issue of Molecular Cell (Elbatsh et al., 2016; Beckouët et al., 2016), cast light on how cohesin regulators harness the energy of ATP hydrolysis to open the cohesin ring and enable dynamic, regulated entrapment of chromosomes.

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