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1.
bioRxiv ; 2024 May 03.
Article in English | MEDLINE | ID: mdl-38746096

ABSTRACT

Cells regulate their shape and metabolic activity in response to the mechano-chemical properties of their microenvironment. To elucidate the impact of matrix stiffness and ligand density on a cell's bioenergetics, we developed a non-equilibrium, active chemo-mechanical model that accounts for mechanical energy of the cell and matrix, chemical energy from ATP hydrolysis, interfacial energy, and mechano-sensitive regulation of stress fiber assembly through signaling. By integrating the kinetics and energetics of these processes we introduce the concept of the metabolic potential of the cell that, when minimized, gives experimentally testable predictions of the cell contractility, shape, and the ATP consumption. Specifically, we show that MDA-MB-231 breast cancer cells in 3D collagen gels follow a spherical to spindle to spherical change in morphology with increasing matrix stiffness consistent with experimental observations. This biphasic transition in cell shape emerges from a competition between increased contractility accompanied by ATP hydrolysis enabled by mechano-sensitive signaling, which lowers the volumetric contribution to the metabolic potential of elongated cells and the interfacial energy which is lower for spherical shapes. On 2D hydrogels, our model predicts a hemispherical to spindle to disc shape transition with increasing gel stiffness. In both cases, we show that increasing matrix stiffness monotonically increases the cell's contractility as well as ATP consumption. Our model also predicts how the increased energy demand in stiffer microenvironments is met by AMPK activation, which is confirmed through experimental measurement of activated AMPK levels as a function of matrix stiffness carried out here in both 2D and 3D micro-environments. Further, model predictions of increased AMPK activation on stiffer micro-environments are found to correlate strongly with experimentally measured upregulation of mitochondrial potential, glucose uptake and ATP levels. The insights from our model can be used to understand mechanosensitive regulation of metabolism in physiological events such as metastasis and tumor progression during which cells experience dynamic changes in their microenvironment and metabolic state.

2.
Mol Ther ; 2024 May 11.
Article in English | MEDLINE | ID: mdl-38734896

ABSTRACT

The disassembly of the neuromuscular junction (NMJ) is an early event in amyotrophic lateral sclerosis (ALS), ultimately leading to motor dysfunction and lethal respiratory paralysis. The hexanucleotide GGGGCC repeat expansion in the C9orf72 gene is the most common genetic mutation, and the dipeptide repeat (DPR) proteins have been shown to cause neurodegeneration. While no drugs can treat ALS patients efficiently, new treatment strategies are urgently needed. Here, we report that a MuSK agonist antibody alleviates poly-PR-induced NMJ deficits in C9orf72-ALS mice. The HB9-PRF/F mice, which express poly-PR proteins in motor neurons, exhibited impaired motor behavior and NMJ deficits. Mechanistically, poly-PR proteins interacted with Agrin to disrupt the interaction between Agrin and Lrp4, leading to attenuated activation of MuSK. Treatment with a MuSK agonist antibody rescued NMJ deficits, and extended the lifespan of C9orf72-ALS mice. Moreover, impaired NMJ transmission was observed in C9orf72-ALS patients. These findings identify the mechanism by which poly-PR proteins attenuate MuSK activation and NMJ transmission, highlighting the potential of promoting MuSK activation with an agonist antibody as a therapeutic strategy to protect NMJ function and prolong the lifespan of ALS patients.

3.
Cytokine ; 179: 156620, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38701735

ABSTRACT

PURPOSE: The emergence of immune checkpoint inhibitors (ICIs) has revolutionized cancer treatment, but these drugs can also cause severe immune-related adverse effects (irAEs), including myocarditis. Researchers have become interested in exploring ways to mitigate this side effect, and one promising avenue is the use of baricitinib, a Janus kinase inhibitor known to have anti-inflammatory properties. This study aimed to examine the potential mechanism by which baricitinib in ICIs-related myocarditis. METHODS: To establish an ICIs-related myocarditis model, BALB/c mice were administered murine cardiac troponin I (cTnI) peptide and anti-mouse programmed death 1 (PD-1) antibodies. Subsequently, baricitinib was administered to the mice via intragastric administration. Echocardiography, HE staining, and Masson staining were performed to evaluate myocardial functions, inflammation, and fibrosis. Immunofluorescence was used to detect macrophages in the cardiac tissue of the mice.In vitro experiments utilized raw264.7 cells to induce macrophage polarization using anti-PD-1 antibodies. Different concentrations of baricitinib were applied to assess cell viability, and the release of pro-inflammatory cytokines was measured. The activation of the JAK1/STAT3 signaling pathway was evaluated through western blot analysis. RESULTS: Baricitinib demonstrated its ability to improve cardiac function and reduce cardiac inflammation, as well as fibrosis induced by ICIs. Mechanistically, baricitinib treatment promoted the polarization of macrophages towards the M2 phenotype. In vitro and in vivo experiments showed that anti-PD-1 promoted the release of inflammatory factors. However, treatment with baricitinib significantly inhibited the phosphorylation of JAK1 and STAT3. Additionally, the use of RO8191 reversed the effects of baricitinib, further confirming our findings. CONCLUSION: Baricitinib demonstrated its potential as a protective agent against ICIs-related myocarditis by modulating macrophage polarization. These findings provide a solid theoretical foundation for the development of future treatments for ICIs-related myocarditis.


Subject(s)
Azetidines , Janus Kinase 1 , Macrophages , Mice, Inbred BALB C , Myocarditis , Purines , Pyrazoles , STAT3 Transcription Factor , Sulfonamides , Animals , Male , Mice , Azetidines/pharmacology , Immune Checkpoint Inhibitors/pharmacology , Janus Kinase 1/metabolism , Macrophage Activation/drug effects , Macrophages/metabolism , Macrophages/drug effects , Myocarditis/chemically induced , Myocarditis/drug therapy , Myocarditis/pathology , Myocarditis/metabolism , Purines/pharmacology , Pyrazoles/pharmacology , RAW 264.7 Cells , Signal Transduction/drug effects , STAT3 Transcription Factor/metabolism , Sulfonamides/pharmacology , Troponin I/metabolism
4.
Echocardiography ; 41(4): e15805, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38558436

ABSTRACT

BACKGROUND: Left ventricular global longitudinal strain (LVGLS) has been recommended by current guidelines for diagnosing anthracycline-induced cardiotoxicity. However, little is known about the early changes in left atrial (LA) morphology and function in this population. Our study aimed to evaluate the potential usefulness of LA indices and their incremental value to LVGLS with three-dimensional echocardiography (3DE) in the early detection of subclinical cardiotoxicity in patients with lymphoma receiving anthracycline. METHODS: A total of 80 patients with diffuse large B-cell lymphoma who received six cycles of anthracycline-based treatment were enrolled. Echocardiography was performed at baseline (T0), after four cycles (T1), and after the completion of six cycles of chemotherapy (T2). Left ventricular ejection fraction (LVEF), LVGLS, LA volumes, LA emptying fraction (LAEF), LA active emptying fraction (LAAEF), and LA reservoir longitudinal strain (LASr) were quantified with 3DE. Left atrioventricular global longitudinal strain (LAVGLS) was calculated as the sum of peak LASr and the absolute value of peak LVGLS (LAVGLS = LASr+|LVGLS|). LV cardiotoxicity was defined as a new LVEF reduction by ≥10 percentage points to an LVEF of ≤50%. RESULTS: Fourteen (17.5%) patients developed LV cardiotoxicity at T2. LA volumes, LAEF, and LAAEF remained stable over time. Impairment of LASr (28.35 ± 5.03 vs. 25.04 ± 4.10, p < .001), LVGLS (-22.77 ± 2.45 vs. -20.44 ± 2.62, p < .001), and LAVGLS (51.12 ± 5.63 vs. 45.61 ± 5.22, p < .001) was observed by the end of the fourth cycle of chemotherapy (T1). Statistically significant declines in LVEF (61.30 ± 4.73 vs. 57.08 ± 5.83, p < .001) were only observed at T2. The relative decrease in LASr (ΔLASr), LVGLS (ΔLVGLS), and LAVGLS (ΔLAVGLS) from T0 to T1 were predictors of LV cardiotoxicity. A ΔLASr of >19.75% (sensitivity, 71.4%; specificity, 87.9%; area under the curve (AUC), .842; p < .001), a ΔLVGLS of >13.19% (sensitivity, 78.6%; specificity, 74.2%; AUC, .763; p < .001), and a ΔLAVGLS of >16.80% (sensitivity, 78.6%; specificity, 93.9%; AUC, .905; p < .001) predicted subsequent LV cardiotoxicity at T2, with the AUC of ΔLAVGLS significantly larger than that of ΔLVGLS (.905 vs. .763, p = .027). Compared to ΔLVGLS, ΔLAVGLS showed improved specificity (93.9% vs. 74.2%, p = .002) and maintained sensitivity in predicting LV cardiotoxicity. CONCLUSIONS: LASr could predict anthracycline-induced LV cardiotoxicity with excellent diagnostic performance. Incorporating LASr into LVGLS (LAVGLS) led to a significantly improved specificity and maintained sensitivity in predicting LV cardiotoxicity.


Subject(s)
Cardiotoxicity , Ventricular Dysfunction, Left , Humans , Cardiotoxicity/diagnostic imaging , Cardiotoxicity/etiology , Ventricular Function, Left , Anthracyclines/adverse effects , Global Longitudinal Strain , Stroke Volume , Antibiotics, Antineoplastic/adverse effects , Ventricular Dysfunction, Left/chemically induced , Ventricular Dysfunction, Left/diagnostic imaging , Ventricular Dysfunction, Left/drug therapy
5.
Metabolites ; 14(4)2024 Mar 25.
Article in English | MEDLINE | ID: mdl-38668312

ABSTRACT

Orbitrap mass spectrometry in full scan mode enables the simultaneous detection of hundreds of metabolites and their isotope-labeled forms. Yet, sensitivity remains limiting for many metabolites, including low-concentration species, poor ionizers, and low-fractional-abundance isotope-labeled forms in isotope-tracing studies. Here, we explore selected ion monitoring (SIM) as a means of sensitivity enhancement. The analytes of interest are enriched in the orbitrap analyzer by using the quadrupole as a mass filter to select particular ions. In tissue extracts, SIM significantly enhances the detection of ions of low intensity, as indicated by improved signal-to-noise (S/N) ratios and measurement precision. In addition, SIM improves the accuracy of isotope-ratio measurements. SIM, however, must be deployed with care, as excessive accumulation in the orbitrap of similar m/z ions can lead, via space-charge effects, to decreased performance (signal loss, mass shift, and ion coalescence). Ion accumulation can be controlled by adjusting settings including injection time and target ion quantity. Overall, we suggest using a full scan to ensure broad metabolic coverage, in tandem with SIM, for the accurate quantitation of targeted low-intensity ions, and provide methods deploying this approach to enhance metabolome coverage.

6.
Nat Chem Biol ; 2024 Mar 06.
Article in English | MEDLINE | ID: mdl-38448734

ABSTRACT

Metabolic efficiency profoundly influences organismal fitness. Nonphotosynthetic organisms, from yeast to mammals, derive usable energy primarily through glycolysis and respiration. Although respiration is more energy efficient, some cells favor glycolysis even when oxygen is available (aerobic glycolysis, Warburg effect). A leading explanation is that glycolysis is more efficient in terms of ATP production per unit mass of protein (that is, faster). Through quantitative flux analysis and proteomics, we find, however, that mitochondrial respiration is actually more proteome efficient than aerobic glycolysis. This is shown across yeast strains, T cells, cancer cells, and tissues and tumors in vivo. Instead of aerobic glycolysis being valuable for fast ATP production, it correlates with high glycolytic protein expression, which promotes hypoxic growth. Aerobic glycolytic yeasts do not excel at aerobic growth but outgrow respiratory cells during oxygen limitation. We accordingly propose that aerobic glycolysis emerges from cells maintaining a proteome conducive to both aerobic and hypoxic growth.

8.
Altern Ther Health Med ; 30(1): 63-67, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37773676

ABSTRACT

Objective: To investigate the clinical value of stressor perception-based meticulous nursing measures during the perioperative period of percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI). Methods and Design: A prospective randomized trial was conducted involving 104 AMI patients undergoing PCI from March 2021 to March 2022. Patients were divided into an "intervention group" and a "routine group" based on consultation numbers, with equal cases in each group. PCI procedures were performed by the same group of doctors in both groups and that basic treatment measures were similar. Intervention and Comparison: The intervention group received meticulous nursing measures based on stressor perception during the perioperative period, while the routine group received standard care. Outcome measures: The study compared treatment effects, perioperative sleep quality, negative emotion scores, and perioperative complication rates between the two groups. Results Overview: The patients in the intervention group and the conventional group were statistically similar in terms of operative time, X-ray fluoroscopy time, contrast agent dosage, catheter lab nurse preparation time, catheter lab-balloon dilation time, portal-ball time, and PCI success rate (P > .05). In the post-PCI assessment of negative emotions in both groups, the total scores of depression, anxiety, extroverted irritability, and negative emotion scores in the intervention group were higher than those in the routine group (P < .05). In the post-PCI assessment of sleep quality in both groups, subjective sleep quality score, sleep delay score, and total PSQI score in the intervention group were lower than those in the routine group (P < .05). The rate of surgical complications was 7.69% in the intervention group and 15.38% in the routine group, and the differences between the two groups were not statistically significant (P > .05). Conclusion: While meticulous nursing measures based on stressor perception did not notably enhance the effectiveness of PCI, they did significantly improve patients' negative emotions and sleep quality.


Subject(s)
Myocardial Infarction , Percutaneous Coronary Intervention , Humans , Prospective Studies , Treatment Outcome , Myocardial Infarction/surgery , Myocardial Infarction/complications , Perception
9.
Nat Commun ; 14(1): 6152, 2023 10 03.
Article in English | MEDLINE | ID: mdl-37788990

ABSTRACT

Microbial production of succinic acid (SA) at an industrially relevant scale has been hindered by high downstream processing costs arising from neutral pH fermentation for over three decades. Here, we metabolically engineer the acid-tolerant yeast Issatchenkia orientalis for SA production, attaining the highest titers in sugar-based media at low pH (pH 3) in fed-batch fermentations, i.e. 109.5 g/L in minimal medium and 104.6 g/L in sugarcane juice medium. We further perform batch fermentation using sugarcane juice medium in a pilot-scale fermenter (300×) and achieve 63.1 g/L of SA, which can be directly crystallized with a yield of 64.0%. Finally, we simulate an end-to-end low-pH SA production pipeline, and techno-economic analysis and life cycle assessment indicate our process is financially viable and can reduce greenhouse gas emissions by 34-90% relative to fossil-based production processes. We expect I. orientalis can serve as a general industrial platform for production of organic acids.


Subject(s)
Bioreactors , Succinic Acid , Fermentation , Pichia
10.
J Phys Chem B ; 127(28): 6233-6240, 2023 07 20.
Article in English | MEDLINE | ID: mdl-37431772

ABSTRACT

Cellular membranes are essential components of all living organisms. They are composed of a complex mixture of lipids with diverse chemical structures and crucial biological functions. The dynamic and heterogeneous nature of cellular membranes presents a challenge for studying their biophysical properties and organization in vivo. Raman imaging, particularly coherent Raman scattering techniques such as stimulated Raman scattering (SRS) microscopy, have emerged as powerful tools for studying cellular membranes with high spatial and temporal resolution and minimal perturbation. In this Review, we discuss the scientific importance and technical challenges of characterizing membrane composition in cellular contexts and how the advances of Raman imaging can provide unique insights into membrane phase behavior and organization. We also highlight recent applications of Raman imaging in studying cellular membranes and implications in diseases. In particular, the discovery of phase separation and a solid-phase intracellular membrane on endoplasmic reticulum is reviewed in detail, shedding light on the biology of lipotoxicity.


Subject(s)
Intracellular Membranes , Microscopy , Microscopy/methods , Cell Membrane , Membranes , Spectrum Analysis, Raman/methods
11.
BMJ Open Ophthalmol ; 8(1)2023 02.
Article in English | MEDLINE | ID: mdl-37278423

ABSTRACT

BACKGROUND: The current study aimed to analyse epidemiological data on eye burns in Wuxi, China, for the years 2015-2021, and to provide insight into the development of appropriate prevention strategies. METHODS: A retrospective study was conducted on 151 hospitalised patients with eye burns. Data collected included gender, age, the monthly distribution of incidence, cause of eye burn, the site of eye burn, the type of surgery, visual outcome, the length of hospital stay and the cost of hospital admission. Statistical analysis was performed using SPSS V.19.0 and Graph Pad Prism V.9.0. RESULTS: In a total of 151 eye burn patients, 130 were males (86.09%) and 21 were females (13.91%). The proportion of patients classified as grade III was the greatest (46.36%). The average age of our hospitalised patients with eye burns was 43.72 years and the average length of hospital stay was 17 days. The number of injuries was highest in September (14.6%). Among eye burn patients, workers and farmers became the most common occupations (62.91%, 12.58%). The most frequent cause of burns was alkali burns (19.21%), followed by acid burns (16.56%). When admitted to the hospital, patients' average vision was 0.06, and 49% of them had a poor vision (<0.3, ≥0.05). CONCLUSION: With an investigation of 7-year hospitalisation data, the current study provided a fundamental reference for epidemiological features and management of eye burns in Wuxi, China, which could contribute to the development of treatment and prevention strategies.


Subject(s)
Burns, Chemical , Eye Burns , Male , Female , Humans , Adult , Retrospective Studies , Burns, Chemical/epidemiology , Eye Burns/epidemiology , Hospitalization , China/epidemiology
12.
Cell Rep ; 42(4): 112400, 2023 04 25.
Article in English | MEDLINE | ID: mdl-37071536

ABSTRACT

Dysregulated amino acid increases the risk for heart failure (HF) via unclear mechanisms. Here, we find that increased plasma tyrosine and phenylalanine levels are associated with HF. Increasing tyrosine or phenylalanine by high-tyrosine or high-phenylalanine chow feeding exacerbates HF phenotypes in transverse aortic constriction and isoproterenol infusion mice models. Knocking down phenylalanine dehydrogenase abolishes the effect of phenylalanine, indicating that phenylalanine functions by converting to tyrosine. Mechanistically, tyrosyl-tRNA synthetase (YARS) binds to ataxia telangiectasia and Rad3-related gene (ATR), catalyzes lysine tyrosylation (K-Tyr) of ATR, and activates the DNA damage response (DDR) in the nucleus. Increased tyrosine inhibits the nuclear localization of YARS, inhibits the ATR-mediated DDR, accumulates DNA damage, and elevates cardiomyocyte apoptosis. Enhancing ATR K-Tyr by overexpressing YARS, restricting tyrosine, or supplementing tyrosinol, a structural analog of tyrosine, promotes YARS nuclear localization and alleviates HF in mice. Our findings implicate facilitating YARS nuclear translocation as a potential preventive and/or interfering measure against HF.


Subject(s)
Heart Failure , Tyrosine-tRNA Ligase , Animals , Mice , Ataxia Telangiectasia Mutated Proteins/metabolism , DNA Damage , Lysine/genetics , Phenylalanine , Tyrosine/metabolism , Tyrosine-tRNA Ligase/chemistry , Tyrosine-tRNA Ligase/genetics , Tyrosine-tRNA Ligase/metabolism
13.
Metab Eng Commun ; 16: e00220, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36860699

ABSTRACT

Methyl methacrylate (MMA) is an important petrochemical with many applications. However, its manufacture has a large environmental footprint. Combined biological and chemical synthesis (semisynthesis) may be a promising alternative to reduce both cost and environmental impact, but strains that can produce the MMA precursor (citramalate) at low pH are required. A non-conventional yeast, Issatchenkia orientalis, may prove ideal, as it can survive extremely low pH. Here, we demonstrate the engineering of I. orientalis for citramalate production. Using sequence similarity network analysis and subsequent DNA synthesis, we selected a more active citramalate synthase gene (cimA) variant for expression in I. orientalis. We then adapted a piggyBac transposon system for I. orientalis that allowed us to simultaneously explore the effects of different cimA gene copy numbers and integration locations. A batch fermentation showed the genome-integrated-cimA strains produced 2.0 g/L citramalate in 48 h and a yield of up to 7% mol citramalate/mol consumed glucose. These results demonstrate the potential of I. orientalis as a chassis for citramalate production.

14.
Nature ; 614(7947): 349-357, 2023 02.
Article in English | MEDLINE | ID: mdl-36725930

ABSTRACT

Tissues derive ATP from two pathways-glycolysis and the tricarboxylic acid (TCA) cycle coupled to the electron transport chain. Most energy in mammals is produced via TCA metabolism1. In tumours, however, the absolute rates of these pathways remain unclear. Here we optimize tracer infusion approaches to measure the rates of glycolysis and the TCA cycle in healthy mouse tissues, Kras-mutant solid tumours, metastases and leukaemia. Then, given the rates of these two pathways, we calculate total ATP synthesis rates. We find that TCA cycle flux is suppressed in all five primary solid tumour models examined and is increased in lung metastases of breast cancer relative to primary orthotopic tumours. As expected, glycolysis flux is increased in tumours compared with healthy tissues (the Warburg effect2,3), but this increase is insufficient to compensate for low TCA flux in terms of ATP production. Thus, instead of being hypermetabolic, as commonly assumed, solid tumours generally produce ATP at a slower than normal rate. In mouse pancreatic cancer, this is accommodated by the downregulation of protein synthesis, one of this tissue's major energy costs. We propose that, as solid tumours develop, cancer cells shed energetically expensive tissue-specific functions, enabling uncontrolled growth despite a limited ability to produce ATP.


Subject(s)
Adenosine Triphosphate , Breast Neoplasms , Citric Acid Cycle , Deceleration , Lung Neoplasms , Neoplasm Metastasis , Pancreatic Neoplasms , Animals , Mice , Adenosine Triphosphate/biosynthesis , Adenosine Triphosphate/metabolism , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Citric Acid Cycle/physiology , Energy Metabolism , Glycolysis , Lung Neoplasms/metabolism , Lung Neoplasms/secondary , Organ Specificity , Pancreatic Neoplasms/metabolism , Pancreatic Neoplasms/pathology , Protein Biosynthesis
15.
Metab Eng ; 76: 1-17, 2023 03.
Article in English | MEDLINE | ID: mdl-36603705

ABSTRACT

The parameterization of kinetic models requires measurement of fluxes and/or metabolite levels for a base strain and a few genetic perturbations thereof. Unlike stoichiometric models that are mostly invariant to the specific strain, it remains unclear whether kinetic models constructed for different strains of the same species have similar or significantly different kinetic parameters. This important question underpins the applicability range and prediction limits of kinetic reconstructions. To this end, herein we parameterize two separate large-scale kinetic models using K-FIT with genome-wide coverage corresponding to two distinct strains of Saccharomyces cerevisiae: CEN.PK 113-7D strain (model k-sacce306-CENPK), and growth-deficient BY4741 (isogenic to S288c; model k-sacce306-BY4741). The metabolic network for each model contains 306 reactions, 230 metabolites, and 119 substrate-level regulatory interactions. The two models (for CEN.PK and BY4741) recapitulate, within one standard deviation, 77% and 75% of the fitted dataset fluxes, respectively, determined by 13C metabolic flux analysis for wild-type and eight single-gene knockout mutants of each strain. Strain-specific kinetic parameterization results indicate that key enzymes in the TCA cycle, glycolysis, and arginine and proline metabolism drive the metabolic differences between these two strains of S. cerevisiae. Our results suggest that although kinetic models cannot be readily used across strains as stoichiometric models, they can capture species-specific information through the kinetic parameterization process.


Subject(s)
Metabolic Flux Analysis , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Kinetics , Models, Biological
16.
Cell Death Differ ; 30(3): 716-730, 2023 03.
Article in English | MEDLINE | ID: mdl-36220889

ABSTRACT

The hexanucleotide GGGGCC repeat expansion in the intronic region of C9orf72 is the most common cause of Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The repeat expansion-generated toxic RNAs and dipeptide repeats (DPRs) including poly-GR, have been extensively studied in neurodegeneration. Moreover, haploinsufficiency has been implicated as a disease mechanism but how C9orf72 deficiency contributes to neurodegeneration remains unclear. Here, we show that C9orf72 deficiency exacerbates poly-GR-induced neurodegeneration by attenuating non-homologous end joining (NHEJ) repair. We demonstrate that C9orf72 localizes to the nucleus and is rapidly recruited to sites of DNA damage. C9orf72 deficiency resulted in impaired NHEJ repair through attenuated DNA-PK complex assembly and DNA damage response (DDR) signaling. In mouse models, we found that C9orf72 deficiency exacerbated poly-GR-induced neuronal loss, glial activation, and neuromuscular deficits. Furthermore, DNA damage accumulated in C9orf72-deficient neurons that expressed poly-GR, resulting in excessive activation of PARP-1. PARP-1 inhibition rescued neuronal death in cultured neurons treated with poly-GR peptides. Together, our results support a pathological mechanism where C9orf72 haploinsufficiency synergizes with poly-GR-induced DNA double-strand breaks to exacerbate the accumulation of DNA damage and PARP-1 overactivation in C9orf72 ALS/FTD patients.


Subject(s)
Amyotrophic Lateral Sclerosis , Frontotemporal Dementia , Animals , Mice , Amyotrophic Lateral Sclerosis/pathology , Frontotemporal Dementia/genetics , C9orf72 Protein/genetics , Poly(ADP-ribose) Polymerase Inhibitors , DNA Repeat Expansion , Dipeptides , DNA Damage , DNA
17.
Nat Chem Biol ; 18(12): 1380-1387, 2022 12.
Article in English | MEDLINE | ID: mdl-35970997

ABSTRACT

Ethanol and lactate are typical waste products of glucose fermentation. In mammals, glucose is catabolized by glycolysis into circulating lactate, which is broadly used throughout the body as a carbohydrate fuel. Individual cells can both uptake and excrete lactate, uncoupling glycolysis from glucose oxidation. Here we show that similar uncoupling occurs in budding yeast batch cultures of Saccharomyces cerevisiae and Issatchenkia orientalis. Even in fermenting S. cerevisiae that is net releasing ethanol, media 13C-ethanol rapidly enters and is oxidized to acetaldehyde and acetyl-CoA. This is evident in exogenous ethanol being a major source of both cytosolic and mitochondrial acetyl units. 2H-tracing reveals that ethanol is also a major source of both NADH and NADPH high-energy electrons, and this role is augmented under oxidative stress conditions. Thus, uncoupling of glycolysis from the oxidation of glucose-derived carbon via rapidly reversible reactions is a conserved feature of eukaryotic metabolism.


Subject(s)
Ethanol , Saccharomyces cerevisiae , Animals , Saccharomyces cerevisiae/metabolism , Ethanol/metabolism , Glucose/metabolism , Citric Acid Cycle , Fermentation , Lactates/metabolism , Mammals
18.
Cell Death Dis ; 13(7): 643, 2022 07 23.
Article in English | MEDLINE | ID: mdl-35871160

ABSTRACT

Doxorubicin (DOX)-based chemotherapy is widely used to treat malignant tumors; however, the cardiotoxicity induced by DOX restricts its clinical usage. A therapeutic dose of DOX can activate ubiquitin-proteasome system. However, whether and how ubiquitin-proteasome system brings out DOX-induced cardiotoxicity remains to be investigated. Here we conducted a proteomics analysis of a DOX-induced cardiotoxicity model to screen the potentially ubiquitination-related molecules. Dysregulated TRIM25 was found to contribute to the cardiotoxicity. In vivo and in vitro cardiotoxicity experiments revealed that TRIM25 ameliorated DOX-induced cardiotoxicity. Electron microscopy and endoplasmic reticulum stress markers revealed that TRIM25 mitigated endoplasmic reticulum stress and apoptosis in DOX-induced cardiomyocytes. Mechanistically, the Co-immunoprecipitation assays and CHX pulse-chase experiment determined that TRIM25 affected p85α stability and promoted its ubiquitination and degradation. This leads to increase of nuclear translocation of XBP-1s, which mitigates endoplasmic reticulum stress. These findings reveal that TRIM25 may have a therapeutic role for DOX-induced cardiotoxicity.


Subject(s)
Cardiotoxicity , Proteasome Endopeptidase Complex , Apoptosis , Cardiotoxicity/drug therapy , Cardiotoxicity/etiology , Cardiotoxicity/metabolism , Doxorubicin/pharmacology , Humans , Myocytes, Cardiac/metabolism , Oxidative Stress , Proteasome Endopeptidase Complex/metabolism , Ubiquitins/metabolism
19.
Nat Commun ; 13(1): 3130, 2022 06 06.
Article in English | MEDLINE | ID: mdl-35668093

ABSTRACT

Hypertension is a pathological condition of persistent high blood pressure (BP) of which the underlying neural mechanisms remain obscure. Here, we show that the afferent nerves in perirenal adipose tissue (PRAT) contribute to maintain pathological high BP, without affecting physiological BP. Bilateral PRAT ablation or denervation leads to a long-term reduction of high BP in spontaneous hypertensive rats (SHR), but has no effect on normal BP in control rats. Further, gain- and loss-of-function and neuron transcriptomics studies show that augmented activities and remodeling of L1-L2 dorsal root ganglia neurons are responsible for hypertension in SHR. Moreover, we went on to show that calcitonin gene-related peptide (CGRP) is a key endogenous suppressor of hypertension that is sequestered by pro-hypertensive PRAT in SHRs. Taken together, we identify PRAT afferent nerves as a pro-hypertensive node that sustains high BP via suppressing CGRP, thereby providing a therapeutic target to tackle primary hypertension.


Subject(s)
Calcitonin Gene-Related Peptide , Hypertension , Adipose Tissue , Animals , Blood Pressure/physiology , Ganglia, Spinal , Hypertension/drug therapy , Rats , Rats, Inbred SHR
20.
BMC Ophthalmol ; 22(1): 146, 2022 Apr 01.
Article in English | MEDLINE | ID: mdl-35365119

ABSTRACT

PURPOSE: To investigate the status of astigmatism in preschool children in Wuxi City, and explore the risk factors related to astigmatism. The risk factors related to astigmatism development as predictors can help us identify preschool children who need vision screening at an early stage to ensure good visual quality. METHODS: The cross-sectional study was conducted in 10 kindergartens randomly selected in five districts of Wuxi City in November 2018. All preschool children were measured by objective refractometry under non-cycloplegic refraction. The basic information of preschool children was collected. The relevant factors of astigmatism in the questionnaire were completed by parents. Spss 26. 0 software was used for univariate and multivariate correlation analysis. RESULTS: A total of 889 preschool children participated in the study, 864 were finally included in the study. The prevalence of astigmatism was 36.0%. The risk of astigmatism in premature children was higher than that in non-premature children (adjusted odds ratio = 1.841). The prevalence of astigmatism with parents' astigmatism history was higher, compared with preschool children without parents' astigmatism history (adjusted odds ratio = 2.037). When maternal age at childbirth was older (≥ 35 years old), the risk of astigmatism increased in preschool children (adjusted odds ratio = 2.181). Compared with bottle feeding, the risk of astigmatism for mixed feeding and breastfeeding reduced in preschool children. Compared with preschool children exposed to electronic screen for less than 2 h every day, preschool children exposed to electronic screen for more than 2 h had an increased risk of astigmatism (P = 0.004). CONCLUSION: The prevalence of astigmatism among preschool children in Wuxi City was high. Some risk factors such as premature birth, parents' astigmatism history, maternal age at childbirth, feeding pattern, and electronic screen exposure time were closely related to the occurrence of astigmatism among preschool children. For preschool children with significant risk factors, their eyesight should be checked regularly to ensure their visual quality.


Subject(s)
Astigmatism , Vision Screening , Adult , Astigmatism/diagnosis , Astigmatism/epidemiology , Child, Preschool , China/epidemiology , Cross-Sectional Studies , Female , Humans , Pregnancy , Prevalence
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