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MBio Jun 2024The purine nucleotides ATP and GTP are made from the common precursor inosine monophosphate (IMP). Maintaining the correct balance of these nucleotides for optimal cell...
UNLABELLED
The purine nucleotides ATP and GTP are made from the common precursor inosine monophosphate (IMP). Maintaining the correct balance of these nucleotides for optimal cell growth is controlled in part by the enzyme IMP dehydrogenase (IMPDH), which catalyzes the first dedicated step of GTP biosynthesis. The regulation of IMPDH mRNA and protein levels in the yeast grown in liquid culture has been studied in some detail, but regulation of IMPDH protein under conditions of cellular crowding on a solid substrate has not been examined. Here, we report real-time, live-cell analysis of the accumulation of the Imd2 isoform of IMPDH in yeast cells forming a monolayer colony in a microfluidic device over a 50-hour time course. We observe two distinct phases of increased Imd2 accumulation: a guanine-insensitive phase early in outgrowth and a guanine-sensitive phase later, when cells become crowded. We show that the IMPDH inhibitor mycophenolic acid enhances both phases of increase. Deletion of a transcription attenuator upstream of the mRNA start site that decreases Imd2 mRNA synthesis in the presence of high GTP increases the baseline level of Imd2 protein 10-fold and abolishes guanine-sensitive but not guanine-insensitive induction. Our results suggest that at least two mechanisms of yeast Imd2 regulation exist, the known GTP-dependent attenuation of RNA polymerase II elongation and a GTP concentration-independent pathway that may be controlled by cell growth state. Live-cell analysis of IMPDH protein levels in a growing yeast colony confirms a known mechanism of regulation and provides evidence for an additional mode of regulation.
IMPORTANCE
This study used live-cell microscopy to track changes in the level of a key enzyme in GTP nucleotide biosynthesis, inosine monophosphate dehydrogenase (IMPDH), during growth of a brewers yeast colony over 2 days in a microfluidic device. The results show that feedback regulation via transcription attenuation allows cells to adapt to nutrient limitation in the crowded environs of a yeast colony. They also identify a novel mode of regulation of IMPDH level that is not driven by guanine nucleotide availability.
PubMed: 38940616
DOI: 10.1128/mbio.01021-24 -
Frontiers in Bioscience (Landmark... Jun 2024Under fasting conditions, the pathway converting gluconeogenesis precursors into muscle glycogen becomes crucial due to reduced glycogen reserves. However, there is...
BACKGROUND
Under fasting conditions, the pathway converting gluconeogenesis precursors into muscle glycogen becomes crucial due to reduced glycogen reserves. However, there is limited research on skeletal muscle gluconeogenesis and the impact of fasting on gluconeogenic gene expression.
METHODS
Sheep fetal skeletal muscle cells cultured were used to study the effects of varying lactic acid concentrations (0 to 30 mM) and 2.5 mM glucose on the expression of gluconeogenesis-related genes after 6 h of fasting. The effects on mRNA and protein expression of key genes involved in skeletal muscle gluconeogenesis were measured by quantitative real time polymerase chain reaction (qRT-PCR), immunofluorescence, and western blotting at 48 h.
RESULTS
Fasting increased the expression of key gluconeogenic genes, fructose-1,6-bisphosphatase 2 (), glucose-6-phosphatase 3 (), pyruvate kinase M (), monocarboxylate transporter1 (), glucose transporter type 4 (), pyruvate carboxylase (), and lactate dehydrogenase A (). The mRNA levels of , , and significantly decreased with glucose addition. Additionally, 10 mM lactic acid significantly promoted the expression of , , , , , and while inhibiting phosphoenolpyruvate carboxykinase () expression. At the protein level, 10 mM lactic acid significantly increased FBP2 and PKM protein expression.
CONCLUSIONS
This study shows that fasting regulates key gluconeogenic gene expression in sheep skeletal muscle cells and highlights the role of lactic acid in inducing these gene expressions.
Topics: Animals; Gluconeogenesis; Sheep; Muscle, Skeletal; Gene Expression Regulation; Glucose; Cells, Cultured; Lactic Acid; Fructose-Bisphosphatase
PubMed: 38940053
DOI: 10.31083/j.fbl2906237 -
Frontiers in Bioscience (Landmark... Jun 2024Nonalcoholic fatty liver disease (NAFLD) is a prevalent condition characterized by hepatic fat accumulation, often progressing to severe liver injury, for which approved...
BACKGROUND
Nonalcoholic fatty liver disease (NAFLD) is a prevalent condition characterized by hepatic fat accumulation, often progressing to severe liver injury, for which approved treatments are currently lacking. This study explores the potential therapeutic impact of alpha-lipoic acid (ALA), a natural compound crucial in lipid metabolism, on NAFLD using an model.
METHODS
HepG2 cells were treated with a palmitic acid:oleic acid (PA:OA) mixture, representing a cellular model of steatosis. Subsequent treatment with ALA at concentrations of 1 µM and 5 µM aimed to evaluate its effects on lipid content and metabolism. Real-time polymerase chain reaction (PCR), BODIPY staining, cytofluorimetric analysis, and lipidomics were used to assess gene expression, lipid droplet accumulation, and fatty acid profiles.
RESULTS
Our results showed that ALA significantly reduced lipid droplets in PA:OA-treated HepG2 cells, with a concentration-dependent effect. Analysis of fatty acid profiles demonstrated a decrease in palmitic acid levels with ALA treatment, while oleic acid reduction was observed only at the higher concentration. Moreover, ALA modulated the expression of genes involved in cholesterol biosynthesis and low-density lipoprotein (LDL) metabolism, indicating a potential role in lipid homeostasis. Further insights into molecular mechanisms revealed that ALA modulated peroxisome proliferator activated receptors (PPARs), specifically PPAR-alpha and PPAR-gamma, involved in fatty acid metabolism and insulin sensitivity. Finally, ALA counteracted the overexpression of thermogenic genes induced by exogenous fatty acids, suggesting a regulatory role in energy dissipation pathways.
CONCLUSION
In conclusion, this study highlights ALA as a therapeutic agent in mitigating lipid accumulation and dysregulation in NAFLD.
Topics: Humans; Thioctic Acid; Hep G2 Cells; Lipid Metabolism; Non-alcoholic Fatty Liver Disease; Oleic Acid; Palmitic Acid; Gene Expression Regulation; Fatty Acids; PPAR gamma; Lipid Droplets; PPAR alpha; Uncoupling Protein 2
PubMed: 38940024
DOI: 10.31083/j.fbl2906209 -
Frontiers in Bioscience (Scholar... Apr 2024Coronavirus disease 19 (COVID-19), an infectious disease resulting from a virus known as severe acute respiratory syndrome coronavirus 2 (SARS-COV-2), was discovered in...
BACKGROUND
Coronavirus disease 19 (COVID-19), an infectious disease resulting from a virus known as severe acute respiratory syndrome coronavirus 2 (SARS-COV-2), was discovered in China in 2019 and causes several mild to moderate respiratory conditions. This study aimed to reveal the changes in serum interleukin-10 (IL-10) and other parameters in Iraqi COVID-19 patients compared with healthy controls by studying the effects of enoxaparin and evaluating the potential of IL-10 as a disease activity marker.
METHODS
This was a case-control study that included 180 samples: 90 patients hospitalized with COVID-19 from November 2022 to 20 April 2023 (40 patients had never used enoxaparin, whereas 50 patients had taken enoxaparin) and 90 healthy, age- and sex-matched control. There were 44 female patients and 46 male patients. The mean age of the patients and controls was 53.8 years 50.8 years, respectively. The sandwich enzyme-linked immunosorbent assay (ELISA) method was used to measure IL-10 levels, while other parameters were assessed using the colorimetric method.
RESULTS
The results of the study indicated highly significant changes between the patients and healthy controls in IL-10, D-dimer, and C-reactive protein (CRP) levels, as well as liver and renal functions. These findings elucidated a significant change between enoxaparin patients and non-enoxaparin patients in IL-10, D-dimer, and CRP levels. However, the liver and renal functions were not significantly altered. The Spearman's rank correlation test investigated the relationship between serum IL-10 and CRP.
CONCLUSIONS
The results displayed a strong positive relationship between IL-10 and CRP. There were no significant differences between the other analyzed parameters; consequently, the patients had higher concentrations of IL-10, D-dimer, and some other parameters than the healthy controls. Additionally, IL-10 may be used as a marker of disease activity. Enoxaparin will likely help control IL-10 and D-dimer concentrations in patients since IL-10 levels decreased in patients treated with enoxaparin.
Topics: Humans; Interleukin-10; Enoxaparin; Male; Female; Case-Control Studies; COVID-19; Middle Aged; Iraq; Adult; C-Reactive Protein; SARS-CoV-2; Biomarkers; COVID-19 Drug Treatment; Anticoagulants; Fibrin Fibrinogen Degradation Products; Aged
PubMed: 38939974
DOI: 10.31083/j.fbs1602009 -
Oncology Letters Aug 2024The aim of the present study was to explore the effects of dexmedetomidine (DEX) combined with ketorolac on postoperative patient-controlled analgesia (PCA), the balance...
Effects of dexmedetomidine and ketorolac applied for patient‑controlled analgesia on the balance of Th1/Th2 and level of VEGF in patients undergoing laparoscopic surgery for cervical cancer: A randomized controlled trial.
The aim of the present study was to explore the effects of dexmedetomidine (DEX) combined with ketorolac on postoperative patient-controlled analgesia (PCA), the balance of Th1/Th2 and the level of vascular endothelial growth factor (VEGF) in patients with cervical cancer following laparoscopic radical surgery. A total of 70 women with cervical cancer undergoing laparoscopic radical hysterectomy were enrolled in the study to randomly receive postoperative dexmedetomidine combined with ketorolac analgesia (DK group) and postoperative sufentanil analgesia (SUF group). The primary outcomes were the serum levels of interleukin-4 (IL-4), interferon-γ (IFN-γ) and VEGF, and the IFN-γ/IL-4 ratio 30 min before induction (T), and 24 and 48 h after surgery. Secondary outcomes included numerical rating scale scores at 0 h (T), 4 h (T), 12 h (T), 24 h (T) and 48 h (T) postoperatively, cumulative times of rescue analgesia, as well as the incidence of postoperative side effects within 48 h from surgery. Patients in the DK group reported similar analgesic effects as patients in the SUF group at T, T and T, and the incidence of postoperative nausea and vomiting was significantly lower in the DK group. In the DK group, the serum concentration of IFN-γ and IFN-γ/IL-4 ratio at 24 and 48 h after surgery were higher compared with those in the SUF group. Conversely, the serum concentrations of IL-4 at 24 h after surgery and VEGF at 24 and 48 h after surgery were significantly lower. The results indicated that the combination of DEX and ketorolac for PCA significantly improved postoperative pain and decreased the serum level of VEGF, which are associated with tumor angiogenesis. In addition, it maintained the homeostasis of postoperative immune dysfunction of patients with cervical cancer by shifting the balance between type 1 T helper cells and type 2 T helper cell (Th1/Th2 balance) to Th1 (registration no. ChiCTR1900027979; December 7, 2019).
PubMed: 38939623
DOI: 10.3892/ol.2024.14512 -
Frontiers in Public Health 2024Ozone pollution is associated with cardiovascular disease mortality, and there is a high correlation between different pollutants. This study aimed to assess the...
BACKGROUND
Ozone pollution is associated with cardiovascular disease mortality, and there is a high correlation between different pollutants. This study aimed to assess the association between ozone and cardiovascular disease deaths and the resulting disease burden in Nanjing, China.
METHODS
A total of 151,609 deaths from cardiovascular disease were included in Nanjing, China from 2013 to 2021. Daily data on meteorological and air pollution were collected to apply a generalized additional model with multiple pollutants to perform exposure-response analyses, stratification analysis, and evaluation of excess deaths using various standards.
RESULTS
In the multi-pollutant model, an increase of 10 μg/m in O was significantly associated with a 0.81% (95%CI: 0.49, 1.12%) increase in cardiovascular disease deaths in lag05. The correlation weakened in both the single-pollutant model and two-pollutant models, but remained more pronounced in females, the older group, and during warm seasons. From 2013 to 2021, the number of excess deaths attributed to ozone exposure in cardiovascular disease continued to rise with an increase in ozone concentration in Nanjing. If the ozone concentration were to be reduced to the WHO standard and the minimum level, the number of deaths would decrease by 1,736 and 10,882, respectively.
CONCLUSION
The risk of death and excess deaths from cardiovascular disease due to ozone exposure increases with higher ozone concentration. Reducing ozone concentration to meet WHO standards or lower can provide greater cardiovascular disease health benefits.
Topics: Ozone; Humans; Cardiovascular Diseases; China; Female; Male; Air Pollutants; Environmental Exposure; Air Pollution; Middle Aged; Aged; Seasons; Adult; Rivers
PubMed: 38939565
DOI: 10.3389/fpubh.2024.1353384 -
Frontiers in Oncology 2024Infections represent one of the most frequent causes of death of higher-risk MDS patients, as reported previously also by our group. Azacitidine Infection Risk Model...
INTRODUCTION
Infections represent one of the most frequent causes of death of higher-risk MDS patients, as reported previously also by our group. Azacitidine Infection Risk Model (AIR), based on red blood cell (RBC) transfusion dependency, neutropenia <0.8 × 10/L, platelet count <50 × 10/L, albumin <35g/L, and ECOG performance status ≥2 has been proposed based on the retrospective data to estimate the risk of infection in azacitidine treated patients.
METHODS
The prospective non-intervention study aimed to identify factors predisposing to infection, validate the AIR score, and assess the impact of antimicrobial prophylaxis on the outcome of azacitidine-treated MDS/AML and CMML patients.
RESULTS
We collected data on 307 patients, 57.6 % males, treated with azacitidine: AML (37.8%), MDS (55.0%), and CMML (7.1%). The median age at azacitidine treatment commencement was 71 (range, 18-95) years. 200 (65%) patients were assigned to higher risk AIR group. Antibacterial, antifungal, and antiviral prophylaxis was used in 66.0%, 29.3%, and 25.7% of patients, respectively. In total, 169 infectious episodes (IE) were recorded in 118 (38.4%) patients within the first three azacitidine cycles. In a multivariate analysis ECOG status, RBC transfusion dependency, IPSS-R score, and CRP concentration were statistically significant for infection development ( < 0.05). The occurrence of infection within the first three azacitidine cycles was significantly higher in the higher risk AIR group - 47.0% than in lower risk 22.4% (odds ratio (OR) 3.06; 95% CI 1.82-5.30, < 0.05). Administration of antimicrobial prophylaxis did not have a significant impact on all-infection occurrence in multivariate analysis: antibacterial prophylaxis (OR 0.93; 0.41-2.05, = 0.87), antifungal OR 1.24 (0.54-2.85) ( = 0.59), antiviral OR 1.24 (0.53-2.82) ( = 0.60).
DISCUSSION
The AIR Model effectively discriminates infection-risk patients during azacitidine treatment. Antimicrobial prophylaxis does not decrease the infection rate.
PubMed: 38939343
DOI: 10.3389/fonc.2024.1404322 -
Frontiers in Microbiology 2024Sodium pheophorbide a (SPA) is a natural plant-derived photosensitizer, with high photoactivated antifungal activity against some phytopathogenic fungi. However, its...
INTRODUCTION
Sodium pheophorbide a (SPA) is a natural plant-derived photosensitizer, with high photoactivated antifungal activity against some phytopathogenic fungi. However, its fungicidal effect on , a novel pathogen that causes leaf spot blight, is unclear.
METHODS
In the present study, we explored its inhibitory effects on spore germination and mycelial growth of . Then we determined its effects on the cell membrane, mycelial morphology, redox homeostasis, and cell death through bioassay. Finally, RNA-seq was used further to elucidate its mode of action at the transcriptional level.
RESULTS
We found that SPA effectively inhibited the growth of , with half-maximal effective concentrations to inhibit mycelial growth and spore germination of 1.059 and 2.287 mg/mL, respectively. After 1.0 mg/mL SPA treatment, the conductivity and malondialdehyde content of were significantly increased. Scanning electron microscopy and transmission electron microscopy indicated that SPA significantly affected the morphology and ultrastructure of hyphae, revealing that SPA can destroy the mycelial morphology and cell structure, especially the cell membrane of . Furthermore, transcriptome analysis revealed that SPA significantly suppressed the expression of genes involved in morphology, cell membrane permeability, and oxidative stress. Then, we also found that SPA significantly promoted the accumulation of reactive oxygen species (ROS) in of , while it decreased the content of reduced glutathione, inhibited the enzyme activities of superoxide dismutase and catalase, and exacerbated DNA damage. Annexin V-FITC/PI staining also confirmed that 1.0 mg/mL SPA could significantly induce apoptosis and necrosis.
DISCUSSION
Generally, SPA can induce ROS-mediated oxidative stress and cell death, thus destroying the cell membrane and hyphal morphology, and ultimately inhibiting mycelial growth, which indicates that SPA has multiple modes of action, providing a scientific basis for the use of SPA as an alternative plant-derived photoactivated fungicide against leaf spot blight.
PubMed: 38939192
DOI: 10.3389/fmicb.2024.1403478 -
Experimental and Therapeutic Medicine Aug 2024Triiodothyronine (T3) concentrations in plasma decrease during acute illness and it is unclear if this contributes to disease. Clinical and laboratory studies of T3...
Triiodothyronine (T3) concentrations in plasma decrease during acute illness and it is unclear if this contributes to disease. Clinical and laboratory studies of T3 supplementation in disease have revealed little or no effect. It is uncertain if short term supplementation of T3 has any discernible effect in a healthy animals. Observational study of intravenous T3 (1 µg/kg/h) for 24 h in a healthy sheep model receiving protocol-guided intensive care supports (T3 group, n=5). A total of 45 endpoints were measured including hemodynamic, respiratory, renal, hematological, metabolic and endocrine parameters. Data were compared with previously published studies of sheep subject to the same support protocol without administered T3 (No T3 group, n=5). Plasma free T3 concentrations were elevated 8-fold by the infusion (pmol/l at 24 h; T3 group 34.9±9.9 vs. No T3 group 4.4±0.3, P<0.01, reference range 1.6 to 6.8). There was no significant physiological response to administration of T3 over the study duration. Supplementation of intravenous T3 for 24 h has no physiological effect on relevant physiological endpoints in healthy sheep. Further research is required to understand if the lack of effect of short-term T3 may be related to kinetics of T3 cellular uptake, metabolism and action, or acute counterbalancing hormone resistance. This information may be helpful in design of clinical T3 supplementation trials.
PubMed: 38939174
DOI: 10.3892/etm.2024.12611 -
Scientifica 2024is well known for its medicinal properties. It has exhibited various pharmacological activities, such as antidiabetic, anti-inflammatory, and antimicrobial activities....
is well known for its medicinal properties. It has exhibited various pharmacological activities, such as antidiabetic, anti-inflammatory, and antimicrobial activities. Although this plant is used worldwide as a vegetable and medicinal ingredient in herbal medicines, its toxicity studies have not been conducted to date. This study attempts to understand its toxicity. The present study examined the activity of two enzymes, acetylcholinesterase and succinate dehydrogenase, as well as histopathological variations in the liver, intestine, and gills of zebrafish. The results of the acetylcholinesterase assay showed that the concentrations of 40 mg/L and 60 mg/L of the four extracts (leaf and fruit extracts of both varieties) exhibited increased enzyme activity. Interestingly, the leaves of the green fruit variety at a concentration of 60 mg/L showed the highest activity, with a value of 2.824 ± 0.0682 micromoles/min compared to the control value of 1.8347 ± 0.0046 micromoles/min. On the other hand, the succinate dehydrogenase assay revealed that the concentrations of 40 mg/L and 60 mg/L of the extracts decreased the enzyme activity. The highest inhibition was observed in the concentration of 60 mg/L of the leaves of the white-fruited variety and the green-fruited variety, with values of 1.884 ± 0.0482 micromoles/min compared to the control value of 2.747 ± 0.0046 micromoles/min. The studies on histopathological changes also demonstrated abnormalities in the brain, liver, intestine, and gills of zebrafish after the exposure to the extracts of . The severity of the damage varied from low to high concentraions. In general, this study sheds light on the safety profile of and highlights its potential toxicity in animal models. The findings suggest that more research is needed to fully understand the toxicity of this plant and its implications for human use.
PubMed: 38938544
DOI: 10.1155/2024/4689625