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The Journal of General Physiology May 2023The Vanilloid thermoTRP (TRPV1-4) subfamily of TRP channels are involved in thermoregulation, osmoregulation, itch and pain perception, (neuro)inflammation and immune...
The Vanilloid thermoTRP (TRPV1-4) subfamily of TRP channels are involved in thermoregulation, osmoregulation, itch and pain perception, (neuro)inflammation and immune response, and tight control of channel activity is required for perception of noxious stimuli and pain. Here we report voltage-dependent modulation of each of human TRPV1, 3, and 4 by the endogenous intracellular polyamine spermine. As in inward rectifier K channels, currents are blocked in a strongly voltage-dependent manner, but, as in cyclic nucleotide-gated channels, the blockade is substantially reduced at more positive voltages, with maximal blockade in the vicinity of zero voltage. A kinetic model of inhibition suggests two independent spermine binding sites with different affinities as well as different degrees of polyamine permeability in TRPV1, 3, and 4. Given that block and relief occur over the physiological voltage range of action potentials, voltage-dependent polyamine block may be a potent modulator of TRPV-dependent excitability in multiple cell types.
Topics: Humans; Spermine; Polyamines; Action Potentials; Potassium Channels, Inwardly Rectifying
PubMed: 36912700
DOI: 10.1085/jgp.202213273 -
Biomolecules Oct 2022Epilepsy is one of the most common neurological disorders and severely impacts the life quality of patients. Polyamines are ubiquitous, positively charged aliphatic... (Review)
Review
Epilepsy is one of the most common neurological disorders and severely impacts the life quality of patients. Polyamines are ubiquitous, positively charged aliphatic amines that are present at a relatively high level and help regulate the maintenance of cell membrane excitability and neuronal physiological functions in the central nervous system. Studies have shown abnormalities in the synthesis and catabolism of polyamines in patients with epilepsy and in animal models of epilepsy. The polyamine system seems to involve in the pathophysiological processes of epilepsy via several mechanisms such as the regulation of ion permeability via interaction with ion channels, involvement in antioxidation as hydroperoxide scavengers, and the induction of cell damage via the production of toxic metabolites. In this review, we try to describe the possible associations between polyamines and epilepsy and speculate that the polyamine system is a potential target for the development of novel strategies for epilepsy treatment.
Topics: Animals; Polyamines; Epilepsy; Central Nervous System; Neurons; Mental Disorders
PubMed: 36358946
DOI: 10.3390/biom12111596 -
International Journal of Molecular... May 2022Altered arginine metabolism (including the polyamine system) has recently been implicated in the pathogenesis of tauopathies, characterised by hyperphosphorylated and...
Altered arginine metabolism (including the polyamine system) has recently been implicated in the pathogenesis of tauopathies, characterised by hyperphosphorylated and aggregated microtubule-associated protein tau (MAPT) accumulation in the brain. The present study, for the first time, systematically determined the time-course of arginine metabolism changes in the P301S (PS19) mouse brain at 2, 4, 6, 8 and 12 months of age. The polyamines putrescine, spermidine and spermine are critically involved in microtubule assembly and stabilization. This study, therefore, further investigated how polyamine biosynthetic and catabolic enzymes changed in PS19 mice. There were general age-dependent increases of L-arginine, L-ornithine, putrescine and spermidine in the PS19 brain (particularly in the hippocampus and parahippocampal region). While this profile change clearly indicates a shift of arginine metabolism to favor polyamine production (a polyamine stress response), spermine levels were decreased or unchanged due to the upregulation of polyamine retro-conversion pathways. Our results further implicate altered arginine metabolism (particularly the polyamine system) in the pathogenesis of tauopathies. Given the role of the polyamines in microtubule assembly and stabilization, future research is required to understand the functional significance of the polyamine stress response and explore the preventive and/or therapeutic opportunities for tauopathies by targeting the polyamine system.
Topics: Animals; Arginine; Brain; Mice; Polyamines; Putrescine; Spermidine; Spermine; Tauopathies
PubMed: 35682712
DOI: 10.3390/ijms23116039 -
Journal For Immunotherapy of Cancer Feb 2023Immune checkpoint blockade (ICB) monotherapy provides poor survival benefit in hepatocellular carcinoma (HCC) due to ICB resistance caused by immunosuppressive tumor...
T cell-mediated targeted delivery of tadalafil regulates immunosuppression and polyamine metabolism to overcome immune checkpoint blockade resistance in hepatocellular carcinoma.
BACKGROUND
Immune checkpoint blockade (ICB) monotherapy provides poor survival benefit in hepatocellular carcinoma (HCC) due to ICB resistance caused by immunosuppressive tumor microenvironment (TME) and drug discontinuation resulting from immune-related side effects. Thus, novel strategies that can simultaneously reshape immunosuppressive TME and ameliorate side effects are urgently needed.
METHODS
Both in vitro and orthotopic HCC models were used to explore and demonstrate the new role of a conventional, clinically used drug, tadalafil (TA), in conquering immunosuppressive TME. In detail, the effect of TA on M2 polarization and polyamine metabolism in tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs) was identified. After making clear the aforementioned immune regulatory effect of TA, we introduced a nanomedicine-based strategy of tumor-targeted drug delivery to make better use of TA to reverse immunosuppressive TME and overcome ICB resistance for HCC immunotherapy. A dual pH-sensitive nanodrug simultaneously carrying both TA and programmed cell death receptor 1 antibody (aPD-1) was developed, and its ability for tumor-targeted drug delivery and TME-responsive drug release was evaluated in an orthotopic HCC model. Finally, the immune regulatory effect, antitumor therapeutic effect, as well as side effects of our nanodrug combining both TA and aPD-1 were analyzed.
RESULTS
TA exerted a new role in conquering immunosuppressive TME by inhibiting M2 polarization and polyamine metabolism in TAMs and MDSCs. A dual pH-sensitive nanodrug was successfully synthesized to simultaneously carry both TA and aPD-1. On one hand, the nanodrug realized tumor-targeted drug delivery by binding to circulating programmed cell death receptor 1-positive T cells and following their infiltration into tumor. On the other hand, the nanodrug facilitated efficient intratumoral drug release in acidic TME, releasing aPD-1 for ICB and leaving TA-encapsulated nanodrug to dually regulate TAMs and MDSCs. By virtue of the combined application of TA and aPD-1, as well as the efficient tumor-targeted drug delivery, our nanodrug effectively inhibited M2 polarization and polyamine metabolism in TAMs and MDSCs to conquer immunosuppressive TME, which contributed to remarkable ICB therapeutic efficacy with minimal side effects in HCC.
CONCLUSIONS
Our novel tumor-targeted nanodrug expands the application of TA in tumor therapy and holds great potential to break the logjam of ICB-based HCC immunotherapy.
Topics: Humans; Carcinoma, Hepatocellular; Tadalafil; Liver Neoplasms; Immune Checkpoint Inhibitors; T-Lymphocytes; Immunosuppression Therapy; Polyamines; Tumor Microenvironment
PubMed: 36813307
DOI: 10.1136/jitc-2022-006493 -
Medical Sciences (Basel, Switzerland) Mar 2021The Japanese diet and the Mediterranean diet are rich in polyamines (spermidine and spermine). Increased polyamine intake elevated blood spermine levels, inhibited...
The Japanese diet and the Mediterranean diet are rich in polyamines (spermidine and spermine). Increased polyamine intake elevated blood spermine levels, inhibited aging-associated pro-inflammatory status (increases in lymphocyte function-associated antigen-1 (LFA-1) on immune cells), suppressed aberrant gene methylation and extended the lifespan of mice. To test the effects of increased polyamine intake by humans, 30 healthy male volunteers were asked to eat polyamine-rich and ready-to-eat traditional Japanese food (natto) for 12 months. Natto with high polyamine content was used. Another 27 male volunteers were asked not to change their dietary pattern as a control group. The volunteers' age of intervention and control groups ranged from 40 to 69 years (median 48.9 ± 7.9). Two subjects in the control group subsequently dropped out of the study. The estimated increases in spermidine and spermine intakes were 96.63 ± 47.70 and 22.00 ± 9.56 µmol per day in the intervention group, while no changes were observed in the control group. The mean blood spermine level in the intervention group gradually rose to 1.12 ± 0.29 times the pre-intervention level after 12 months, and were significantly higher ( = 0.019) than those in the control group. Blood spermidine did not increase in either group. LFA-1 on monocytes decreased gradually in the intervention group, and there was an inverse association between changes in spermine concentrations relative to spermidine and changes in LFA-1 levels. Contingency table analysis revealed that the odds ratio to decrease LFA-1 by increased polyamine intake was 3.927 (95% CI 1.116-13.715) ( = 0.032) when the effect of acute inflammation was excluded. The results in the study were similar to those of our animal experiments. Since methylation changes of the entire genome are associated with aging-associated pathologies and our previous studies showed that spermine-induced LFA-1 suppression was associated with the inhibition of aberrant gene methylation, the results suggest that dietary polyamine contributes to human health and longevity.
Topics: Animals; Diet; Lymphocyte Function-Associated Antigen-1; Male; Mice; Polyamines; Spermidine; Spermine
PubMed: 33805535
DOI: 10.3390/medsci9020022 -
Molecules and Cells Dec 2022Exogenous polyamines are able to induce life span and improve glucose homeostasis and insulin sensitivity. However, the effects of exogenous polyamines on adipocyte...
Exogenous polyamines are able to induce life span and improve glucose homeostasis and insulin sensitivity. However, the effects of exogenous polyamines on adipocyte differentiation and which polyamine transporters mediate them have not been elucidated yet. Here, we identified for the first time that exogenous polyamines can clearly stimulate adipocyte differentiation through polyamine transporters, solute carrier family 3 member A2 (SLC3A2) and SLC7A1. Exogenous polyamines markedly promote 3T3-L1 adipocyte differentiation by increasing the intracellular lipid accumulation and the expression of both adipogenic and lipogenic genes in a concentration-dependent manner. In particular, exogenous putrescine mainly regulates adipocyte differentiation in the early and intermediate stages. Moreover, we have assessed the expression of polyamine transporter genes in 3T3-L1 preadipocytes and adipocytes. Interestingly, the putrescine-induced adipocyte differentiation was found to be significantly suppressed in response to a treatment with a polyamine transporter inhibitor (AMXT-1501). Furthermore, knockdown experiments using siRNA that specifically targeted SLC3A2 or SLC7A2, revealed that both SLC3A2 and SLC7A2 act as important transporters in the cellular importing of exogenous putrescine. Thus, the exogenous putrescine entering the adipocytes via cellular transporters is involved in adipogenesis through a modulation of both the mitotic clonal expansion and the expression of master transcription factors. Taken together, these results suggest that exogenous polyamines (such as putrescine) entering the adipocytes through polyamine transporters, can stimulate adipogenesis.
Topics: Animals; Mice; 3T3-L1 Cells; Adipocytes; Adipogenesis; Cell Differentiation; Fusion Regulatory Protein 1, Heavy Chain; Polyamines; Putrescine; Amino Acid Transport Systems, Basic
PubMed: 36572564
DOI: 10.14348/molcells.2022.0123 -
The Yale Journal of Biology and Medicine 1989The polyamines and their derivatives are essential for life in eukaryotic and most prokaryotic cells, but their exact role in preserving cell function is not clear.... (Review)
Review
The polyamines and their derivatives are essential for life in eukaryotic and most prokaryotic cells, but their exact role in preserving cell function is not clear. These polyamines provide endogenous cations and thus participate in regulation of the intracellular pH; in addition, polyamine derivatives modulate cell growth and differentiation. The naturally occurring monoacetyl derivatives can induce increased activity of ornithine decarboxylase, the first enzyme in polyamine synthesis, and thus produce positive feedback to their production. The diacetyl derivatives of putrescine and of the synthetic analogue, 1,6-diaminohexane, induce differentiation and inhibit growth in many types of cells in vitro. In addition, they inhibit the proliferative and secretory response of normal B lymphocytes to B-cell mitogens and reduce production of antibodies in vitro. They also inhibit the proliferation of chronic lymphocytic leukemia cells (a B-lymphocyte leukemia). The parent polyamines are post-translational modifiers of proteins, and hypusine, a derivative of spermidine, is a covalently bound constituent of the eukaryotic protein synthetic initiation factor, eIF-4D. Although these various actions do not at present fall into a coherent pattern, they clearly indicate that polyamines and their derivatives play an important part in modulating cell proliferation and differentiation.
Topics: Cell Differentiation; Cell Division; Ornithine Decarboxylase; Polyamines
PubMed: 2697982
DOI: No ID Found -
International Journal of Molecular... Jun 2022Naturally occurring polyamines are absolutely required for cellular growth and proliferation. Many neoplastic cells are reliant on elevated polyamine levels and maintain...
Naturally occurring polyamines are absolutely required for cellular growth and proliferation. Many neoplastic cells are reliant on elevated polyamine levels and maintain these levels through dysregulated polyamine metabolism. The modulation of polyamine metabolism is thus a promising avenue for cancer therapeutics and has been attempted with numerous molecules, including enzyme inhibitors and polyamine analogues. SBP-101 (diethyl dihydroxyhomospermine) is a spermine analogue that has shown efficacy in slowing pancreatic tumor progression both in vitro and in vivo; however, the mechanisms underlying these effects remain unclear. We determined the effects of the SBP-101 treatment on a variety of cancer cell types in vitro, including lung, pancreatic, and ovarian. We evaluated the activity of enzymes involved in polyamine metabolism and the effect on intracellular polyamine pools following the SBP-101 treatment. The SBP-101 treatment produced a modest but variable increase in polyamine catabolism; however, a robust downregulation of the activity of the biosynthetic enzyme, ornithine decarboxylase (ODC), was seen across all of the cell types studied and indicates that SBP-101 likely exerts its effect predominately through the downregulation of ODC, with a minor upregulation of catabolism. Our in vitro work indicated that SBP-101 was most toxic in the tested ovarian cell lines. Therefore, we evaluated the efficacy of SBP-101 as a monotherapy in the immunosuppressive VDID8 murine ovarian model. Mice treated with SBP-101 demonstrated a delay in tumor progression, a decrease in the overall tumor burden, and a marked increase in median survival.
Topics: Animals; Antineoplastic Agents; Mice; Neoplasms; Ornithine Decarboxylase; Polyamines; Spermine
PubMed: 35743239
DOI: 10.3390/ijms23126798 -
Molecular Cancer Research : MCR Jan 2023Identifying and leveraging unique points of metabolic dysregulation in different disease settings is vital for safe and effective incorporation of metabolism-targeted...
UNLABELLED
Identifying and leveraging unique points of metabolic dysregulation in different disease settings is vital for safe and effective incorporation of metabolism-targeted therapies in the clinic. In addition, it has been shown identification of master metabolic transcriptional regulators (MMTR) of individual metabolic pathways, and how they relate to the disease in question, may offer the key to understanding therapeutic response. In prostate cancer, we have previously demonstrated polyamine biosynthesis and the methionine cycle were targetable metabolic vulnerabilities. However, the MMTRs of these pathways, and how they affect treatment, have yet to be explored. We sought to characterize differential sensitivity of prostate cancer to polyamine- and methionine-targeted therapies by identifying novel MMTRs. We began by developing a gene signature from patient samples, which can predict response to metabolic therapy, and further uncovered a MMTR, JAZF1. We characterized the effects of JAZF1 overexpression on prostate cancer cells, basally and in the context of treatment, by assessing mRNA levels, proliferation, colony formation capability, and key metabolic processes. Lastly, we confirmed the relevance of our findings in large publicly available cohorts of prostate cancer patient samples. We demonstrated differential sensitivity to polyamine and methionine therapies and identified JAZF1 as a MMTR of this response.
IMPLICATIONS
We have shown JAZF1 can alter sensitivity of cells and its expression can segregate patient populations into those that do, or do not highly express polyamine genes, leading to better prediction of response to a polyamine targeting therapy.
Topics: Male; Humans; Polyamines; Prostatic Neoplasms; Methionine; Metabolic Networks and Pathways; DNA-Binding Proteins; Co-Repressor Proteins
PubMed: 36166196
DOI: 10.1158/1541-7786.MCR-22-0316 -
Biomolecules Mar 2020Polyamines are essential growth factors that have a positive role in cancer cell growth. Their metabolic pathway and the diverse enzymes involved have been studied in...
Polyamines are essential growth factors that have a positive role in cancer cell growth. Their metabolic pathway and the diverse enzymes involved have been studied in depth in multiple organisms and cells. Polyamine transport also contributes to the intracellular polyamine content but this is less well-studied in mammalian cells. As the polyamine transporters could provide a means of selective drug delivery to cancer cells, a greater understanding of polyamine transport and its regulation is needed. In this study, transport of polyamines and polyamine content was measured and the effect of modulating each was determined in human colorectal cancer cells. The results provide evidence that upregulation of polyamine transport depends on polyamine depletion and on the rate of cell growth. Polyamine transport occurred in all colorectal cancer cell lines tested but to varying extents. The cell lines with the lowest basal uptake showed the greatest increase in response to polyamine depletion. Kinetic parameters for putrescine and spermidine suggest the existence of two separate transporters. Transport was shown to be a saturable but non-polarised process that can be regulated both positively and negatively. Using the polyamine transporter to deliver anticancer drugs more selectively is now a reality, and the ability to manipulate the polyamine transport process increases the possibility of using these transporters therapeutically.
Topics: Biological Transport; Cell Line, Tumor; Colorectal Neoplasms; Eflornithine; Humans; Polyamines; Up-Regulation
PubMed: 32218236
DOI: 10.3390/biom10040499