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Cell Reports. Medicine Nov 2023In preclinical models, α-difluoromethylornithine (DFMO), an ornithine decarboxylase (ODC) inhibitor, delays the onset of type 1 diabetes (T1D) by reducing β cell... (Randomized Controlled Trial)
Randomized Controlled Trial
In preclinical models, α-difluoromethylornithine (DFMO), an ornithine decarboxylase (ODC) inhibitor, delays the onset of type 1 diabetes (T1D) by reducing β cell stress. However, the mechanism of DFMO action and its human tolerability remain unclear. In this study, we show that mice with β cell ODC deletion are protected against toxin-induced diabetes, suggesting a cell-autonomous role of ODC during β cell stress. In a randomized controlled trial (ClinicalTrials.gov: NCT02384889) involving 41 recent-onset T1D subjects (3:1 drug:placebo) over a 3-month treatment period with a 3-month follow-up, DFMO (125-1,000 mg/m) is shown to meet its primary outcome of safety and tolerability. DFMO dose-dependently reduces urinary putrescine levels and, at higher doses, preserves C-peptide area under the curve without apparent immunomodulation. Transcriptomics and proteomics of DFMO-treated human islets exposed to cytokine stress reveal alterations in mRNA translation, nascent protein transport, and protein secretion. These findings suggest that DFMO may preserve β cell function in T1D through islet cell-autonomous effects.
Topics: Humans; Mice; Animals; Diabetes Mellitus, Type 1; Ornithine Decarboxylase; Ornithine Decarboxylase Inhibitors; Eflornithine; Putrescine
PubMed: 37918404
DOI: 10.1016/j.xcrm.2023.101261 -
Chemistry & Biodiversity Dec 2023We present the inhibitory properties of the Solanum nigrescens anthocyanin fraction (SNAF) and its major constituents on alpha-glucosidase (AG), pancreatic lipase (PL),...
We present the inhibitory properties of the Solanum nigrescens anthocyanin fraction (SNAF) and its major constituents on alpha-glucosidase (AG), pancreatic lipase (PL), HMG-CoA reductase, and ornithine decarboxylase (ODC). The effect of SNAF was simultaneously evaluated in ICR male mice exposed to triglyceride charge test (TCT). HPLC-MS profiling revealed the presence cyanidin-3-O-rutinoside-5-glucoside (CRG), delphinidin-3-(p-coumaroyl)-rutinoside-5-glucoside (DCRG), and petunidin-3-(cis-p-coumaroyl)-rutinoside-5-glucoside (PCRG) as major constituents of the fraction. SNAF, CRG, and specially PCRG, induced strong non-competitive inhibition on PL (IC , 33-86 μg mL ). The results of TCT confirmed their capacity to ameliorate (p <0.001) hypertriglyceridemia during postprandial and interdigestive stages. SNAF, CRG, DCRG, and PCRG caused negligible growth inhibition (MIC>600 μg mL ) on beneficial bacteria whereas SNAF and DCRG exerted inhibitory activity on Helicobacter pylori ATCC 53504 (MIC,187-64 μg mL ). Additional exploration revealed that SNAF and DCRG produced non-competitive activity on H. pylori urease, which facilitates bacterial growth under acidic conditions.
Topics: Mice; Animals; Helicobacter pylori; Solanum; Anthocyanins; Mice, Inbred ICR; Dietary Supplements; Hypertriglyceridemia; Glucosides; Chromatography, High Pressure Liquid
PubMed: 37874748
DOI: 10.1002/cbdv.202301423 -
Andrology Jul 2024The implications of SARS-CoV-2 infection on male fertility remain largely unknown. Besides their well-known pro- and anti-inflammatory actions, prostaglandins and...
BACKGROUND
The implications of SARS-CoV-2 infection on male fertility remain largely unknown. Besides their well-known pro- and anti-inflammatory actions, prostaglandins and polyamines are present in semen, where they play key roles in sperm quality.
OBJECTIVES
To analyze semen parameters, oxidative profile and the seminal fluid prostaglandin and polyamine systems in samples collected from individuals without coronavirus disease 2019 diagnosis and men who recovered from coronavirus disease 2019.
MATERIALS AND METHODS
This study compared semen collected from men without positive coronavirus disease 2019 diagnosis with samples obtained from individuals 1-6 months and 7-30 months post SARS-CoV-2 infection. Semen parameters, thiobarbituric acid reactive substances, cyclooxygenase 2 expression by fluorescence immunocytochemistry and immunoblotting, prostaglandin levels by enzyme immunoassay, ornithine decarboxylase activity by a radioactive assay, and polyamine and acetylated polyamine levels by thin-layer chromatography were assessed.
RESULTS
In both groups of semen samples from coronavirus disease 2019 recovered men, sperm vitality, total and progressive sperm motility, and putrescine levels were significantly decreased when compared with samples from the uninfected group. In contrast, lipid peroxidation, leukocyte-associated cyclooxygenase 2 expression, and prostaglandin D2 levels were higher in semen from coronavirus disease 2019 recovered men than in samples from uninfected individuals. While sperm concentration and morphology, ornithine decarboxylase activity, and N-acetylputrescine levels were statistically diminished in semen obtained up to 6 months after coronavirus disease 2019 recovery, these parameters remained unchanged when samples were collected 7-30 months after coronavirus disease 2019 recovery. Coronavirus disease 2019 vaccination did not show negative effects on any of the parameters evaluated.
DISCUSSION AND CONCLUSION
Our work provides insights into the detrimental impact of coronavirus disease 2019 on several sperm parameters, in some cases, even more than a year after SARS-CoV-2 infection, which would be accompanied by alterations in the seminal fluid prostaglandin and polyamine profiles. Therefore, future treatments targeting the prostaglandin and polyamine pathways in coronavirus disease 2019 recovered men could lead to a successful reinstatement of semen parameters.
Topics: Male; Humans; COVID-19; Prostaglandins; Polyamines; Semen; Adult; Semen Analysis; SARS-CoV-2; Spermatozoa; Sperm Motility; Middle Aged
PubMed: 37873918
DOI: 10.1111/andr.13548 -
Plant Physiology and Biochemistry : PPB Oct 2023Thallium (TI) is a toxic metal that can trigger harmful impacts on growth and metabolism of plants. Utilizing arbuscular mycorrhizal fungi (AMF) proves to be an...
Thallium (TI) is a toxic metal that can trigger harmful impacts on growth and metabolism of plants. Utilizing arbuscular mycorrhizal fungi (AMF) proves to be an effective strategy for alleviating heavy metal toxicity in plants. To this end, AMF were applied to mitigate TI toxic effects on the growth, primary and secondary metabolism of soybean plants. Here, TI stress inhibited the growth and photosynthetic parameters of soybean plants. It also increased the oxidative damage as demonstrated by increased levels of oxidative markers, (MDA and lipoxygenase (LOX) activity). However, AMF could mitigate the reduction in growth and photosynthesis induced by TI, as well as the induction of oxidative damage. To overcome TI toxicity, AMF increased the levels and metabolism of osmolytes such as proline in soybean plants. This was in line with the increased activities of key enzymes that involved in proline biosynthesis (e.g., P5CS (pyrroline-5-carboxylate synthetase), P5CR (pyrroline-5-carboxylate reductase) and OAT (ornithine aminotransferase) under the AMF and/or TI treatments. Furthermore, soybean plants could benefit from the synergism between AMF and TI to enhance the contents of individual (e.g., spermine and spermidine) and total polyamines as well as their metabolic enzymes (e.g., arginine decarboxylase and ornithine decarboxylase). Overall, the combined application of AMF emerges as a viable approach for alleviating TI toxicity in soybean plants.
Topics: Mycorrhizae; Glycine max; Thallium; Photosynthesis; Plants; Proline
PubMed: 37827045
DOI: 10.1016/j.plaphy.2023.108077 -
International Journal of Molecular... Sep 2023Colorectal cancer (CRC) has been proven to be highly reliant on arginine availability. Limiting arginine-rich foods or treating patients with arginine-depleting enzymes...
Colorectal cancer (CRC) has been proven to be highly reliant on arginine availability. Limiting arginine-rich foods or treating patients with arginine-depleting enzymes arginine deiminase (ADI) or arginase can suppress colon cancer. However, arginase and ADI are not the best drug candidates for CRC. Ornithine, the product of arginase, can enhance the supply of polyamine, which favors CRC cell growth, while citrulline, the product of ADI, faces the problem of arginine recycling due to the overexpression of argininosuccinate synthetase (ASS). Biosynthetic arginine decarboxylase (ADC), an enzyme that catalyzes the conversion of arginine to agmatine and carbon dioxide, may be a better choice as it combines both arginine depletion and suppression of intracellular polyamine synthesis via its product agmatine. ADC has anti-tumor potential yet has received much less attention than the other two arginine-depleting enzymes. In order to gain a better understanding of ADC, the preparation and the anti-cancer properties of this enzyme were explored in this study. When tested in vitro, ADC inhibited the proliferation of three colorectal cancer cell lines regardless of their ASS cellular expression. In contrast, ADC had a lesser cytotoxic effect on the human foreskin fibroblasts and rat primary hepatocytes. Further in vitro studies revealed that ADC induced S and G2/M phase cell-cycle arrest and apoptosis in HCT116 and LoVo cells. ADC-induced apoptosis in HCT116 cells followed the mitochondrial apoptotic pathway and was caspase-3-dependent. With all results obtained, we suggest that arginine is a potential target for treating colorectal cancer with ADC, and the anti-cancer properties of ADC should be more deeply investigated in the future.
Topics: Humans; Animals; Rats; Arginase; Agmatine; Colonic Neoplasms; Arginine
PubMed: 37762044
DOI: 10.3390/ijms241813741 -
Cell Death & Disease Sep 2023The enzyme arginase 1 (A1) hydrolyzes the amino acid arginine to form L-ornithine and urea. Ornithine is further converted to polyamines by the ornithine decarboxylase...
The enzyme arginase 1 (A1) hydrolyzes the amino acid arginine to form L-ornithine and urea. Ornithine is further converted to polyamines by the ornithine decarboxylase (ODC) enzyme. We previously reported that deletion of myeloid A1 in mice exacerbates retinal damage after ischemia/reperfusion (IR) injury. Furthermore, treatment with A1 protects against retinal IR injury in wild-type mice. PEG-A1 also mitigates the exaggerated inflammatory response of A1 knockout (KO) macrophages in vitro. Here, we sought to identify the anti-inflammatory pathway that confers macrophage A1-mediated protection against retinal IR injury. Acute elevation of intraocular pressure was used to induce retinal IR injury in mice. A multiplex cytokine assay revealed a marked increase in the inflammatory cytokines interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α) in the retina at day 5 after IR injury. In vitro, blocking the A1/ODC pathway augmented IL-1β and TNF-α production in stimulated macrophages. Furthermore, A1 treatment attenuated the stimulated macrophage metabolic switch to a pro-inflammatory glycolytic phenotype, whereas A1 deletion had the opposite effect. Screening for histone deacetylases (HDACs) which play a role in macrophage inflammatory response showed that A1 deletion or ODC inhibition increased the expression of HDAC3. We further showed the involvement of HDAC3 in the upregulation of TNF-α but not IL-1β in stimulated macrophages deficient in the A1/ODC pathway. Investigating HDAC3 KO macrophages showed a reduced inflammatory response and a less glycolytic phenotype upon stimulation. In vivo, HDAC3 co-localized with microglia/macrophages at day 2 after IR in WT retinas and was further increased in A1-deficient retinas. Collectively, our data provide initial evidence that A1 exerts its anti-inflammatory effect in macrophages via ODC-mediated suppression of HDAC3 and IL-1β. Collectively we propose that interventions that augment the A1/ODC pathway and inhibit HDAC3 may confer therapeutic benefits for the treatment of retinal ischemic diseases.
Topics: Animals; Mice; Arginase; Cytokines; Ischemia; Myeloid Cells; Ornithine; Ornithine Decarboxylase; Reperfusion Injury; Retinal Diseases; Tumor Necrosis Factor-alpha
PubMed: 37735154
DOI: 10.1038/s41419-023-06147-7 -
Journal of Biomolecular Structure &... Sep 2023Breast cancer is the second-leading cause of cancer-related death in women and the most often diagnosed malignancy. As the majority of chemotherapeutic medications are...
Breast cancer is the second-leading cause of cancer-related death in women and the most often diagnosed malignancy. As the majority of chemotherapeutic medications are associated with recurrence, drug resistance, and side effects, scientists are shifting to beneficial agents for prevention and treatment, such as natural molecules. Myricetin 3-rhamnoside, a natural flavonol glycoside is known for diverse pharmacological activities but fewer reports describe the antiproliferative ability. The study aims to investigate the antiproliferative efficacy and target [hyaluronidase (HYAL) and ornithine decarboxylase (ODC), two poor breast cancer prognostic markers] modulatory potential of myricetin 3-rhamnoside on breast cancer cell lines using cytotoxicity assays and docking, molecular dynamics analysis, cell-free and cell-based test methods. Myricetin 3-rhamnoside significantly retard the growth of MDA-MB-231 cells in SRB (IC 88.64 ± 7.14 µM) and MTT (56.26 ± 8.50 µM) assay. It suppressed the transition of cells to the S-phase by inducing arrest in the G0/G1 phase with a fold change of 1.10. It shows robust binding interaction with ODC (-7.90 kcal/mol) and HYAL (-9.46 kcal/mol) and inhibits ODC (15.22 ± 2.61 µM) and HYAL (11.92 ± 2.89 µM) activity, but in a cell-based assay, the prominent response was observed against HYAL (21.46 ± 4.03 µM). Besides, it shows a 1.38 fold-down regulation of HYAL and forms a stable complex with HYAL. The binding pocket for myricetin 3-rhamnoside and the simulation pocket during the simulation are identical, indicating that myricetin 3-rhamnoside is actively blocking hyaluronidase. The computational prediction suggests it is a safe molecule. These observations imply that myricetin 3-rhamnoside could be used as a pharmacophore to design and synthesize a novel and safe agent for managing hormone-independent breast cancer.Communicated by Ramaswamy H. Sarma.
PubMed: 37732353
DOI: 10.1080/07391102.2023.2256872 -
The Journal of Physical Chemistry. B Sep 2023The pyridoxal 5'-phosphate (PLP) acts as a coenzyme for a large number of biochemical reactions. It exists in mainly two bound forms at the active site of the concerned...
The pyridoxal 5'-phosphate (PLP) acts as a coenzyme for a large number of biochemical reactions. It exists in mainly two bound forms at the active site of the concerned enzyme: the internal aldimine, in which the PLP is bound with the ϵ-amino group of lysine at the active site, and the external aldimine, where the PLP is bound to the substrate amino acid. Both the internal and external aldimines have Schiff base linkage (N-H-O) and can exist in two tautomeric structures of ketoenamine and enolimine forms. In this work, we have investigated the free energy landscape for the tautomeric proton transfer in the internal and external aldimines at the active site of the ornithine decarboxylase enzyme in an aqueous medium. We performed hybrid quantum-classical metadynamics and force field-based molecular dynamics simulations, which revealed that the ketoenamine tautomer is more stable than the enolimine form. The QM/MM metadynamics calculations show that the free energy difference between the ketoenamine and enolimine forms for the internal aldimine is 3.9 kcal/mol, and it is found to be 5.8 kcal/mol for the external aldimine, with the ketoenamine form being more stable in both cases. The results are further supported by calculations of the binding free energies from classical simulations and static quantum chemical calculations in different environments. We have also analyzed the configurational structure of the microenvironment at the active site in order to have better insights into the interactions of the active site residues with the PLP in its two tautomeric forms.
Topics: Catalytic Domain; Ornithine Decarboxylase; Schiff Bases; Protons; Pyridoxal Phosphate; Phosphates
PubMed: 37721415
DOI: 10.1021/acs.jpcb.3c04142 -
Brazilian Journal of Microbiology :... Dec 2023Rhizosphere soil of aromatic rice inhabits different fungal species that produce many bioactive metabolites including 2-acetyl-1-pyrroline (2AP). The mechanism for the...
Rhizosphere soil of aromatic rice inhabits different fungal species that produce many bioactive metabolites including 2-acetyl-1-pyrroline (2AP). The mechanism for the biosynthesis of 2AP in the fungal system is still elusive. Hence, the present study investigates the role of possible nitrogen (N) precursors such as some amino acids and polyamines as well as the enzymes involved in 2AP synthesis in the fungal species isolated from the rhizosphere of aromatic rice varieties. Three fungal isolates were found to synthesize 2AP (0.32-1.07 ppm) and maximum 2AP was synthesized by Aspergillus niger (1.07 ppm) isolated from rhizosphere of Dehradun Basmati (DB). To determine the N source for 2AP synthesis, various N sources such as proline, glutamate, ornithine putrescine, spermine, and spermidine were used in place of putrescine in the synthetic medium (Syn18). The results showed that maximum 2AP synthesis was found with putrescine (1.07 ppm) followed by spermidine (0.89 ppm) and spermine (0.84 ppm). Further, LC-QTOF-MS analysis revealed the mobilization of spermine and spermidine into the putrescine, indicating that putrescine is the key N source for 2AP synthesis. Moreover, higher enzyme activity of DAO, PAO, and ODC as well as higher content of methylglyoxal metabolite in the A. niger NFCCI 5060 as compared to A. niger NFCCI 4064 (control) suggests the prominent role of these enzymes in the synthesis of 2AP. In conclusion, this study showed evidence of the polyamines mediated 2AP biosynthesis in A. niger NFCCI 5060.
Topics: Polyamines; Spermidine; Putrescine; Spermine; Aspergillus niger; Oryza; Ornithine Decarboxylase
PubMed: 37702923
DOI: 10.1007/s42770-023-01124-w -
Plants (Basel, Switzerland) May 2023Cadmium (Cd) is a heavy metal that is widely contaminating the environment due to its uses in industries as corrosive reagents, paints, batteries, etc. Cd can easily be...
Cadmium (Cd) is a heavy metal that is widely contaminating the environment due to its uses in industries as corrosive reagents, paints, batteries, etc. Cd can easily be absorbed through plant roots and may have serious negative impacts on plant growth. To investigate the mechanisms utilized by plants to cope with Cd toxicity, an experiment was conducted on maize seedlings. We observed that the plant growth and photosynthetic mechanism were negatively influenced during 20 days of Cd stress. The expression levels of ornithine decarboxylase () increased in the six seedlings under Cd exposure compared to the control. However, Cd toxicity led to an increase in putrescine (Put) content only on day 15 when compared to the control plants. In fact, with the exception of day 15, the increases in the transcript levels did not show a direct correlation with the observed increases in Put content. Spermidine and Spermine levels were reduced on day 6 by Cd application, which was parallel with suppressed Spermidine synthase gene. However, an increase in Spermidine and Spermine levels was observed on day 12 along with a significant elevation in Spermidine synthase expression. On day 6, Cd was observed to start accumulating in the root with an increase in the expression of microRNA 528; while on day 15, Cd started to be observed in the shoot part with an increase in microRNA 390 and microRNA 168. These results imply that different miRNAs may regulate polyamines (PAs) in maize under Cd toxicity, suggesting a plant-derived strategy to commit a PAs/miRNA-regulated mechanism/s in different developmental stages (time points) in response to Cd exposure.
PubMed: 37653908
DOI: 10.3390/plants12101991