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1.
Int J Mol Sci ; 25(5)2024 Feb 28.
Article in English | MEDLINE | ID: mdl-38474034

ABSTRACT

The advent of biologic drugs has revolutionized the treatment of Inflammatory Bowel Disease, increasing rates of response and mucosal healing in comparison to conventional therapies by allowing the treatment of corticosteroid-refractory cases and reducing corticosteroid-related side effects. However, biologic therapies (anti-TNFα inhibitors, anti-α4ß7 integrin and anti-IL12/23) are still burdened by rates of response that hover around 40% (in biologic-naïve patients) or lower (for biologic-experienced patients). Moreover, knowledge of the mechanisms underlying drug resistance or loss of response is still scarce. Several cellular and molecular determinants are implied in therapeutic failure; genetic predispositions, in the form of single nucleotide polymorphisms in the sequence of cytokines or Human Leukocyte Antigen, or an altered expression of cytokines and other molecules involved in the inflammation cascade, play the most important role. Accessory mechanisms include gut microbiota dysregulation. In this narrative review of the current and most recent literature, we shed light on the mentioned determinants of therapeutic failure in order to pave the way for a more personalized approach that could help avoid unnecessary treatments and toxicities.


Subject(s)
Biological Products , Inflammatory Bowel Diseases , Humans , Inflammatory Bowel Diseases/drug therapy , Cytokines/metabolism , Tumor Necrosis Factor-alpha/therapeutic use , Adrenal Cortex Hormones/therapeutic use , Biological Products/therapeutic use
2.
Eur J Nutr ; 61(2): 625-636, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34687321

ABSTRACT

PURPOSE: In less than one and a half year, the COVID-19 pandemic has nearly brought to a collapse our health care and economic systems. The scientific research community has concentrated all possible efforts to understand the pathogenesis of this complex disease, and several groups have recently emphasized recommendations for nutritional support in COVID-19 patients. In this scoping review, we aim at encouraging a deeper appreciation of magnesium in clinical nutrition, in view of the vital role of magnesium and the numerous links between the pathophysiology of SARS-CoV-2 infection and magnesium-dependent functions. METHODS: By searching PubMed and Google Scholar from 1990 to date, we review existing evidence from experimental and clinical studies on the role of magnesium in chronic non-communicable diseases and infectious diseases, and we focus on recent reports of alterations of magnesium homeostasis in COVID-19 patients and their association with disease outcomes. Importantly, we conduct a census on ongoing clinical trials specifically dedicated to disclosing the role of magnesium in COVID-19. RESULTS: Despite many methodological limitations, existing data seem to corroborate an association between deranged magnesium homeostasis and COVID-19, and call for further and better studies to explore the prophylactic or therapeutic potential of magnesium supplementation. CONCLUSION: We propose to reconsider the relevance of magnesium, frequently overlooked in clinical practice. Therefore, magnesemia should be monitored and, in case of imbalanced magnesium homeostasis, an appropriate nutritional regimen or supplementation might contribute to protect against SARS-CoV-2 infection, reduce severity of COVID-19 symptoms and facilitate the recovery after the acute phase.


Subject(s)
COVID-19 , Homeostasis , Humans , Magnesium , Pandemics , SARS-CoV-2
3.
J Cell Biochem ; 118(12): 4526-4535, 2017 12.
Article in English | MEDLINE | ID: mdl-28471540

ABSTRACT

We investigated activity and mechanism of action of two AhR ligand antitumor agents, AFP 464 and 5F 203 on human renal cancer cells, specifically examining their effects on cell cycle progression, apoptosis, and migration. TK-10, SN12C, Caki-1, and ACHN human renal cancer cell lines were treated with AFP 464 and 5F 203. We evaluated cytotoxicity by MTS assays, cell cycle arrest, and apoptosis by flow cytometry and corroborated a mechanism of action involving AhR signal transduction activation. Changes in migration properties by wound healing assays were investigated: 5F 203-sensitive cells show decreased migration after treatment, therefore, we measured c-Met phosphorylation by Western blot in these cells. A 5F 203 induced a decrease in cell viability which was more marked than AFP 464. This cytotoxicity was reduced after treatment with the AhR inhibitor α-NF for both compounds indicating AhR signaling activation plays a role in the mechanism of action. A 5F 203 is sequestered by TK-10 cells and induces CYP1A1 expression; 5F 203 potently inhibited migration of TK-10, Caki-1, and SN12C cells, and inhibited c-Met receptor phosphorylation in TK-10 cells. AhR ligand antitumor agents AFP 464 and 5F 203 represent potential new candidates for the treatment of renal cancer. A 5F 203 only inhibited migration of sensitive cells and c-Met receptor phosphorylation in TK-10 cells. c-Met receptor signal transduction is important in migration and metastasis. Therefore, we consider that 5F 203 offers potential for the treatment of metastatic renal carcinoma. J. Cell. Biochem. 118: 4526-4535, 2017. © 2017 Wiley Periodicals, Inc.


Subject(s)
Antineoplastic Agents/pharmacology , Carcinoma, Renal Cell/drug therapy , Flavonoids/pharmacology , Kidney Neoplasms/drug therapy , Neoplasm Proteins/agonists , Receptors, Aryl Hydrocarbon/agonists , Thiazoles/pharmacology , Carcinoma, Renal Cell/metabolism , Carcinoma, Renal Cell/pathology , Cell Line, Tumor , Humans , Kidney Neoplasms/metabolism , Kidney Neoplasms/pathology , Neoplasm Proteins/metabolism , Receptors, Aryl Hydrocarbon/metabolism , Signal Transduction/drug effects
4.
Chem Res Toxicol ; 29(3): 317-22, 2016 Mar 21.
Article in English | MEDLINE | ID: mdl-26918850

ABSTRACT

Magnesium is directly involved in the control of cell growth and survival, but its role in cancer biology and therapy is multifaceted; in particular, it is highly controversial whether magnesium levels can affect therapy outcomes. Here we investigated whether magnesium availability can modulate cellular responses to the widely used chemotherapeutic doxorubicin. We used an in vitro model consisting of mammary epithelial HC11 cells and found that high magnesium availability was correlated with diminished sensitivity both in cells chronically adapted to high magnesium concentrations and in acutely magnesium-supplemented cells. This decrease in sensitivity resulted from reduced intracellular doxorubicin accumulation in the face of a similar drug uptake rate. We observed that high-magnesium conditions caused a decrease in intracellular drug retention by altering drug lysosomal sequestration and trafficking. In our model, magnesium supplementation correspondingly modulated expression of the TRPM7 channel, which is known to control cytoskeletal organization and dynamics and may be involved in the proposed mechanism. Our findings suggest that magnesium supplementation in hypomagnesemic cancer patients may hinder response to therapy.


Subject(s)
Antibiotics, Antineoplastic/metabolism , Antibiotics, Antineoplastic/pharmacology , Doxorubicin/metabolism , Doxorubicin/pharmacology , Lysosomes/drug effects , Lysosomes/metabolism , Magnesium/pharmacology , Cell Proliferation/drug effects , Cells, Cultured , Dose-Response Relationship, Drug , Humans , MCF-7 Cells , Protein Serine-Threonine Kinases/metabolism , Structure-Activity Relationship , TRPM Cation Channels/metabolism
5.
Hum Mutat ; 35(1): 58-62, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24130152

ABSTRACT

A 0.8 kb intronic duplication in MAGT1 and a single base pair deletion in the last exon of ATRX were identified using a chromosome X-specific microarray and exome sequencing in a family with five males demonstrating intellectual disability (ID) and unusual skin findings (e.g., generalized pruritus). MAGT1 is an Mg²âº transporter previously associated with primary immunodeficiency and ID, whereas mutations in ATRX cause ATRX-ID syndrome. In patient cells, the function of ATRX was demonstrated to be abnormal based on altered RNA/protein expression, hypomethylation of rDNA, and abnormal cytokinesis. Dysfunction of MAGT1 was reflected in reduced RNA/protein expression and Mg²âº influx. The mutation in ATRX most likely explains the ID, whereas MAGT1 disruption could be linked to abnormal skin findings, as normal magnesium homeostasis is necessary for skin health. This work supports observations that multiple mutations collectively contribute to the phenotypic variability of syndromic ID, and emphasizes the importance of correlating clinical phenotype with genomic and cell function analyses.


Subject(s)
Cation Transport Proteins/genetics , Cation Transport Proteins/metabolism , DNA Helicases/genetics , DNA Helicases/metabolism , Mental Retardation, X-Linked/genetics , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Pruritus/genetics , Chromosomes, Human, X , Cytokinesis , DNA Methylation , DNA, Ribosomal/metabolism , Exome , Female , Genes, Duplicate , Humans , Introns , Magnesium/metabolism , Male , Mental Retardation, X-Linked/metabolism , Mental Retardation, X-Linked/pathology , Oligonucleotide Array Sequence Analysis , Pedigree , Phenotype , Point Mutation , Pruritus/pathology , Sequence Analysis, DNA , Syndrome , X-linked Nuclear Protein
6.
Biochem Biophys Res Commun ; 454(4): 572-5, 2014 11 28.
Article in English | MEDLINE | ID: mdl-25450695

ABSTRACT

Magnesium is well established as a fundamental factor that regulates cell proliferation. However, the molecular mechanisms linking mitogenic signals, extracellular magnesium availability and intracellular effectors are still largely unknown. In the present study we sought to determine whether EGF regulates magnesium homeostasis in normal HC11 mammary epithelial cells. To this end, we measured Mg(2+) and Ca(2+) fluxes by confocal imaging in live cells loaded with specific fluorescent ion indicators (Mag-Fluo-4 and Fluo-4, respectively). EGF stimulation induces a rapid and sustained increase in intracellular Mg(2+), concomitantly with a rise in intracellular calcium. The increase in intracellular Mg(2+) derives from an influx from the extracellular compartment, and does not depend on Ca(2+). On the contrary, the increase in intracellular Ca(2+) derives from intracellular stores, and is impaired in the absence of extracellular magnesium. Inhibition of the EGF receptor tyrosine kinase by Tyrphostin AG1478 markedly inhibits EGF-induced Mg(2+) and Ca(2+) signals. These findings demonstrate that not only does Mg(2+) influx represent an important step in the physiological response of epithelial cells to EGF, but unexpectedly the EGF-induced Mg(2+) influx is essential for the Ca(2+) signal to occur.


Subject(s)
Epidermal Growth Factor/pharmacology , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Magnesium/metabolism , Animals , Cells, Cultured , ErbB Receptors/antagonists & inhibitors , ErbB Receptors/metabolism , Female , Mice , Mice, Inbred BALB C
7.
Magnes Res ; 0(0)2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38652733

ABSTRACT

Since the start of the COVID-19 pandemic, it has become increasingly clear that the disease can have relevant multisystemic and long-term effects, and several studies have attempted to identify key determinants of the disease course. Here we discuss recent evidence suggesting that, in long COVID patients, combined magnesium and vitamin D deficiencies associate with a higher number of clinical manifestations, as compared to patients with normal levels of both nutrients. We highlight the potential synergistic effects of these deficiencies and propose that future studies should explore a causal link with the risk of developing long COVID. Most importantly, randomized clinical trials are needed to determine if magnesium and vitamin D supplementation can improve long COVID symptoms, providing a safe and affordable support therapy to the benefit of patients and society.

8.
Nutrients ; 16(10)2024 May 07.
Article in English | MEDLINE | ID: mdl-38794644

ABSTRACT

Endothelial dysfunction is a crucial event in the early pathogenesis of cardiovascular diseases and is linked to magnesium (Mg) deficiency. Indeed, in endothelial cells, low Mg levels promote the acquisition of a pro-inflammatory and pro-atherogenic phenotype. This paper investigates the mechanisms by which Mg deficiency promotes oxidative stress and affects endothelial behavior in human umbilical vascular endothelial cells (HUVECs). Our data show that low Mg levels trigger oxidative stress initially by increasing NAPDH oxidase activity and then by upregulating the pro-oxidant thioredoxin-interacting protein TXNIP. The overproduction of reactive oxygen species (ROS) activates NF-κB, leading to its increased binding to the inducible nitric oxide synthase (iNOS) promoter, with the consequent increase in iNOS expression. The increased levels of nitric oxide (NO) generated by upregulated iNOS contribute to disrupting endothelial cell function by inhibiting growth and increasing permeability. In conclusion, we provide evidence that multiple mechanisms contribute to generate a pro-oxidant state under low-Mg conditions, ultimately affecting endothelial physiology. These data add support to the notion that adequate Mg levels play a significant role in preserving cardiovascular health and may suggest new approaches to prevent or manage cardiovascular diseases.


Subject(s)
Human Umbilical Vein Endothelial Cells , Magnesium Deficiency , Magnesium , Nitric Oxide Synthase Type II , Nitric Oxide , Oxidative Stress , Reactive Oxygen Species , Humans , Nitric Oxide Synthase Type II/metabolism , Nitric Oxide Synthase Type II/genetics , Magnesium Deficiency/metabolism , Reactive Oxygen Species/metabolism , Nitric Oxide/metabolism , Magnesium/metabolism , NF-kappa B/metabolism , Carrier Proteins/metabolism , Carrier Proteins/genetics , Endothelium, Vascular/metabolism
9.
Clin Sci (Lond) ; 123(7): 417-27, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22671428

ABSTRACT

The relationship between magnesium and cancer is not as simple as could be assumed from the well-established requirement of magnesium for cell proliferation. Basic and pre-clinical studies indicate that magnesium deficiency can have both anti- and pro-tumour effects. In the present review, we briefly outline the new findings on the role of magnesium in angiogenesis and metastatization, and focus on the relationship between tumour cell proliferation and metabolic reprogramming, discussing how magnesium and its transporters are involved in these processes. The role of magnesium in cancer is also critically examined with regard to mitochondrial function, apoptosis and resistance to treatment. Finally, we bring together the latest experimental evidence indicating that alteration in the expression and/or activity of magnesium channels is a frequent finding in cancer cells and human tumour tissues examined to date, and we discuss the potential implications for developing novel diagnostic and therapeutic strategies.


Subject(s)
Magnesium/metabolism , Neoplasms/metabolism , Neoplasms/pathology , TRPM Cation Channels/metabolism , Animals , Humans , Protein Serine-Threonine Kinases
10.
Eur J Ophthalmol ; 32(5): 2760-2770, 2022 Sep.
Article in English | MEDLINE | ID: mdl-34878320

ABSTRACT

PURPOSE: To assess the impact of preoperative intravitreal dexamethasone implant (DexI) on functional and anatomic outcomes in patients with diabetic macular edema (DME) who underwent phacoemulsification cataract surgery. METHODS: Prospective and non-comparative study conducted on consecutive DME patients undergoing cataract surgery. DexI was administered 15 days before surgery and in a pro re nata regime after surgery. Main outcome measures were mean change in central retinal thickness (CRT), central subfield thickness (CST), total macular volume (TMV), and central subfield volume (CSV) from baseline to month-12. Secondary outcome was mean change in best corrected visual acuity (BCVA). RESULTS: Forty eyes were included in the study. CRT significantly decreased from 410.4 ± 64.8 µm at baseline to 303.2 ± 24.3 µm at month-12, p < 0.0001. Similarly, CST was significantly reduced from 436.4 ± 120.4 µm at baseline to 322.9 ± 54.2 µm at month-12, p < 0.0001. Total macular volume and CSV were significantly reduced from 9.95 ± 1.68 mm3 and 0.38 ± 0.11 mm3 at baseline to 8.49 ± 0.83 mm3 and 0.31 ± 0.05 mm3 at month-12, respectively (p < 0.0001 each, respectively). BCVA significantly improved from 0.26 ± 0.17 Snellen equivalent at baseline to 0.65 ± 0.19 at month-12, p < 0.0001. Mean DexI administered during the study were 2.0 ± 0.3. Neither DME subtype nor previous treatment status had any effect on functional or anatomic outcomes. Regarding safety, one (2.5%) eye developed ocular hypertension, which was successfully controlled with topical hypotensive treatment. CONCLUSIONS: DexI was and effective and safe strategy for managing DME in diabetic patients undergoing uneventful cataract surgery.


Subject(s)
Cataract , Diabetes Mellitus , Diabetic Retinopathy , Macular Edema , Phacoemulsification , Cataract/complications , Dexamethasone , Diabetic Retinopathy/complications , Diabetic Retinopathy/diagnosis , Diabetic Retinopathy/drug therapy , Drug Implants/therapeutic use , Glucocorticoids , Humans , Intravitreal Injections , Macular Edema/diagnosis , Macular Edema/drug therapy , Macular Edema/etiology , Prospective Studies , Tomography, Optical Coherence
11.
Nutrients ; 13(12)2021 Nov 23.
Article in English | MEDLINE | ID: mdl-34959740

ABSTRACT

Nutritional deficiencies are common in inflammatory bowel diseases (IBD). In patients, magnesium (Mg) deficiency is associated with disease severity, while in murine models, dietary Mg supplementation contributes to restoring mucosal function. Since Mg availability modulates key bacterial functions, including growth and virulence, we investigated whether the beneficial effects of Mg supplementation during colitis might be mediated by gut microbiota. The effects of dietary Mg modulation were assessed in a murine model of dextran sodium sulfate (DSS)-induced colitis by monitoring magnesemia, weight, and fecal consistency. Gut microbiota were analyzed by 16S-rRNA based profiling on fecal samples. Mg supplementation improved microbiota richness in colitic mice, increased abundance of Bifidobacterium and reduced Enterobacteriaceae. KEEG pathway analysis predicted an increase in biosynthetic metabolism, DNA repair and translation pathways during Mg supplementation and in the presence of colitis, while low Mg conditions favored catabolic processes. Thus, dietary Mg supplementation increases bacteria involved in intestinal health and metabolic homeostasis, and reduces bacteria involved in inflammation and associated with human diseases, such as IBD. These findings suggest that Mg supplementation may be a safe and cost-effective strategy to ameliorate disease symptoms and restore a beneficial intestinal flora in IBD patients.


Subject(s)
Colitis/microbiology , Colitis/therapy , Gastrointestinal Microbiome/drug effects , Magnesium/pharmacology , Animals , Colitis/chemically induced , Dextran Sulfate , Disease Models, Animal , Dysbiosis/microbiology , Dysbiosis/therapy , Feces/microbiology , Female , Magnesium Deficiency/microbiology , Magnesium Deficiency/therapy , Mice , Mice, Inbred C57BL , RNA, Ribosomal, 16S
12.
Acta Ophthalmol ; 99(1): e74-e80, 2021 Feb.
Article in English | MEDLINE | ID: mdl-32588978

ABSTRACT

PURPOSE: To report clinical outcomes of two different timings of intravitreal dexamethasone (DEX) implant administration for prevention of diabetic macular oedema (DME) worsening following cataract surgery. METHODS: This multicentre, retrospective study included patients with DME who received an intravitreal DEX implant 1 month before cataract surgery, 'precataract DEX' group, or at the time of cataract surgery, 'concomitant treatments' group. Inclusion criteria were a follow-up ≥3 months and ophthalmological examination with optical coherence tomography (OCT) imaging at baseline (cataract surgery) and throughout follow-up. Anatomical improvement was considered to be a decrease in OCT central subfield (CSF) thickness ≥20% compared to baseline. The primary outcomes were anatomical and functional results at 3 months. RESULTS: Two hundred twenty-one patients were included: 136 in the 'precataract DEX' group and 85 in the 'concomitant treatments' group. At 3 months, a reduction of CSF thickness ≥ 20% was found in 7.3% of eyes in the 'precataract DEX group' and in 83.7% of eyes in the 'concomitant treatments' group (p < 0.001), with mean CSF thickness lower in the latter group (371 ± 52 µm versus 325 ± 57 µm, p < 0.001). At 3 months, mean best-corrected visual acuity had improved from baseline in both groups (p < 0.001), with no difference between groups (p = 0. 20). No serious systemic adverse events were reported. CONCLUSION: Both approaches prevented a worsening of DME, showing a comparable visual outcome. Dexamethasone (DEX) implant given at the same time as cataract surgery provided a better anatomical outcome.


Subject(s)
Cataract Extraction , Cataract/complications , Dexamethasone/administration & dosage , Diabetic Retinopathy/drug therapy , Macular Edema/drug therapy , Visual Acuity , Aged , Diabetic Retinopathy/complications , Diabetic Retinopathy/diagnosis , Drug Implants , Female , Follow-Up Studies , Glucocorticoids/administration & dosage , Humans , Intravitreal Injections , Macular Edema/complications , Macular Edema/diagnosis , Male , Retrospective Studies , Time Factors , Tomography, Optical Coherence , Treatment Outcome
13.
J Cell Physiol ; 222(2): 374-81, 2010 Feb.
Article in English | MEDLINE | ID: mdl-19890837

ABSTRACT

Mammary epithelial cells (HC11) chronically adapted to grow in a low-magnesium (0.05 mM vs. 0.5 mM) or in a high-magnesium (40 mM) medium were used to investigate on the mechanisms of cell magnesium transport under conditions of non-physiological magnesium availability. Magnesium influx was higher in low-magnesium cells compared to control or high-magnesium cells, whereas magnesium efflux was higher in high-magnesium cells compared to control and low-magnesium cells. Magnesium efflux was partially inhibited by imipramine, inhibitor of the Na(+)/Mg(2+) exchange. Using a monoclonal antibody detecting a approximately 70 kDa protein associated with Na(+)/Mg(2+) exchange activity, we found that the expression levels of this protein were proportional to magnesium efflux capacity, that is, high-magnesium cells > control cells > low-magnesium cells. As for magnesium influx, this was abolished by Co(III)hexaammine, inhibitor of magnesium channels. Surprisingly, we found that cells grown in low magnesium upregulated mRNA for the magnesium channel TRPM6, but not for other channels like TRPM7 or MagT1. TRPM6 mRNA was also rapidly upregulated or downregulated in HC11 cells deprived of magnesium or in low-magnesium cells re-added with magnesium, respectively. TRPM6 protein levels, as assessed by Western blot and immunofluorescence, underwent similar changes under comparable conditions. We propose that mammary epithelial cells adapt to decreased magnesium availability by upregulating magnesium influx via TRPM6, and counteract increased magnesium availability by increasing magnesium efflux primarily via Na(+)/Mg(2+) exchange. These results show, for the first time, that TRPM6 contributes to regulating magnesium influx in mammary epithelial cells, similar to what is known for intestine and kidney.


Subject(s)
Antiporters/metabolism , Epithelial Cells/metabolism , Magnesium/metabolism , Mammary Glands, Animal/metabolism , Sodium/metabolism , TRPM Cation Channels/metabolism , Adaptation, Physiological , Animals , Antiporters/antagonists & inhibitors , Biological Transport , Blotting, Western , Cell Line , Cobalt/pharmacology , Epithelial Cells/drug effects , Female , Fluorescent Antibody Technique , Imipramine/pharmacology , Kinetics , Mammary Glands, Animal/cytology , Mammary Glands, Animal/drug effects , Mice , Microscopy, Confocal , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction , TRPM Cation Channels/antagonists & inhibitors , TRPM Cation Channels/genetics
14.
Analyst ; 135(8): 1855-66, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20544083

ABSTRACT

A wide variety of biochemical reactions and physiological functions are known to require magnesium; nonetheless, its regulatory mechanisms (both at the cellular and systemic level) are still poorly characterised. Derangement of magnesium homeostasis is associated with several relevant human pathologies, e.g. diabetes, neuromuscular disorders, hypertension and other cardiovascular diseases. The study of the regulation of magnesium has gained particular interest in the last decades thanks to the molecular characterisation of specific magnesium transporters and the exploitation of molecular biology techniques to clarify their cellular and physiological function(s). In contrast, experimental tools to trace cellular magnesium and to define its homeostasis in living cells have not witnessed a corresponding progress. It was not until recently that efforts were paid to design more appropriate fluorescent indicators that could translate the advances of live imaging techniques into the field of magnesium research. Herein we critically summarise the state of the art in intracellular magnesium detection by fluorescent probes and focus on the need for improving methods and techniques in this area. We highlight the advantages of last-generation fluorescent indicators and discuss a number of challenges and opportunities that the development of novel and better sensors for magnesium still faces.


Subject(s)
Intracellular Space/chemistry , Magnesium/analysis , Molecular Imaging/methods , Fluorescent Dyes/analysis , Fluorescent Dyes/chemistry , Humans , Intracellular Space/metabolism , Magnesium/metabolism , Spectrometry, Fluorescence
15.
Clin Ophthalmol ; 14: 2657-2665, 2020.
Article in English | MEDLINE | ID: mdl-32982158

ABSTRACT

PURPOSE: There has been an increasing clinical interest in specific retinal parameters as non-invasive biomarkers of retinal inflammation in diabetic macular edema (DME) that have been shown to have prognostic value, such as hyperreflective retinal fields (HRFs) and subfoveal neuroretinal detachment (SND). METHODS: We conducted a prospective, non-comparative study of treatment-naïve patients with DME to evaluate the efficacy of a Pro Re Nata (PRN) regimen of intravitreal dexamethasone implant 0.7 mg (DexI, Ozurdex™). After administration, patients underwent subsequent injections according to PRN criteria in case of edema relapse, but not earlier than 4 months after the previous treatment. Patients were evaluated at baseline, within 15 days of injection, and every month thereafter. During all visits, best-corrected visual acuity (BCVA) was recorded; central retinal thickness (CRT), type of edema, presence of SND, and presence and number of HRFs were evaluated using swept-source optical coherence tomography (SS-OCT) 3D. Treatment outcome was defined as changes in BCVA, CRT, SND and HRFs at 12 (T12) and 24 (T24) months compared with baseline (T0). RESULTS: The study enrolled 24 eyes of 18 patients. The mean duration of follow-up was 18±6.6 months; for all eyes, T12 data were available, while follow-up reached T24 for 12 eyes. BCVA improved significantly and CRT decreased significantly during treatment; the edema was no longer detectable in 13/24 eyes at T12 and 8/12 eyes at T24. No patient presented SND at T12 and T24, and the mean number of HRFs decreased significantly during treatment. Results with CRT and HRFs correlated with BCVA at 12 and 24 months. No significant adverse events were observed. CONCLUSION: In patients with DME, the intravitreal dexamethasone implant was effective and safe in improving both functional and tomographic parameters. This result is consistent with improvement in biomarkers of inflammation.

16.
Nutrients ; 12(11)2020 Oct 26.
Article in English | MEDLINE | ID: mdl-33114586

ABSTRACT

Hypomagnesemia is very commonly observed in cancer patients, most frequently in association with therapy with cetuximab (CTX), a monoclonal antibody targeting the epithelial growth factor receptor (EGFR). CTX-induced hypomagnesemia has been ascribed to renal magnesium (Mg) wasting. Here, we sought to clarify whether CTX may also influence intestinal Mg absorption and if Mg supplementation may interfere with CTX activity. We used human colon carcinoma CaCo-2 cells as an in vitro model to study the mechanisms underlying Mg transport and CTX activity. Our findings demonstrate that TRPM6 is the key channel that mediates Mg influx in intestinal cells and that EGF stimulates such influx; consequently, CTX downregulates TRPM6-mediated Mg influx by interfering with EGF signaling. Moreover, we show that Mg supplementation does not modify either the CTX IC50 or CTX-dependent inhibition of ERK1/2 phosphorylation. Our results suggest that reduced Mg absorption in the intestine may contribute to the severe hypomagnesemia that occurs in CTX-treated patients, and Mg supplementation may represent a safe and effective nutritional intervention to restore Mg status without impairing the CTX efficacy.


Subject(s)
Cetuximab/adverse effects , Epidermal Growth Factor/metabolism , Intestinal Absorption/drug effects , Magnesium/metabolism , TRPM Cation Channels/metabolism , Caco-2 Cells , Colon/metabolism , Humans , Renal Tubular Transport, Inborn Errors/chemically induced , Renal Tubular Transport, Inborn Errors/metabolism
17.
Dig Liver Dis ; 52(10): 1188-1194, 2020 10.
Article in English | MEDLINE | ID: mdl-32505565

ABSTRACT

BACKGROUND: Inflammatory bowel disease (IBD) predisposes to colorectal cancer (CRC) with some specific features that distinguish it from sporadic CRC. Magnesium (Mg) homeostasis is severely compromised in IBD patients, which may affect both inflammation and tumor development. Efficient transcellular Mg transport in intestinal cells depends on the transient receptor potential melastatin (TRPM) channels type 6 and 7, but their expression has never been investigated in the context of IBD-related CRC. AIMS: We sought to study the expression pattern of TRPM6 and TRPM7 in CRC, and to compare IBD-related cases to sporadic cases. METHODS: TRPM6 and TRPM7 protein expression was evaluated by immunohistochemistry in surgical specimens from 16 IBD and 13 NON-IBD CRC patients. RESULTS: TRPM7 expression was higher in tumor tissue than in the adjacent non-neoplastic tissue in both IBD and NON-IBD patients. Overall, adenocarcinomas showed a higher TRPM7 expression than adenomas. TRPM7 expression also positively correlated with tumor grade. Conversely, TRPM6 expression was higher in tumor tissues in both IBD and NON-IBD CRC, but it did not correlate with tumor stage or grade. CONCLUSIONS: We report a possible participation of TRPM6 and 7 in both IBD-related and sporadic CRC and suggest that TRPM7 might serve as a marker of malignant transformation and lack of differentiation.


Subject(s)
Adenocarcinoma/genetics , Colorectal Neoplasms/genetics , Inflammatory Bowel Diseases/genetics , Protein Serine-Threonine Kinases/genetics , TRPM Cation Channels/genetics , Adenocarcinoma/etiology , Biomarkers/blood , Case-Control Studies , Colorectal Neoplasms/etiology , Colorectal Neoplasms/pathology , Female , Gene Expression , Humans , Inflammatory Bowel Diseases/complications , Magnesium/metabolism , Male
18.
Nutr Cancer ; 61(1): 131-6, 2009.
Article in English | MEDLINE | ID: mdl-19116883

ABSTRACT

Low Mg availability reversibly inhibited the growth of mammary epithelial HC11 cells by increasing the number of cells in the G0/G1 phase of the cell cycle. Because low Mg has been reported to promote oxidative reactions, we considered that low Mg-dependent growth arrest was mediated by oxidative stress. Surprisingly, both dichlorofluorescein-detectable reactive oxygen species and hydrogen peroxide-induced oxidative DNA damage were found to be lower in cells cultured in low Mg than in cells grown under control or high-Mg conditions. Gene expression profiling of low- and high-Mg cells showed the modulation of several genes, some regulating cell proliferation. In addition, low Mg cells also displayed overexpression of glutathione S-transferase (GST), leading to increased enzymatic activity. Of note, GST has been shown to modulate cell growth; therefore, we suggest that in low-Mg cells, GST upregulation might have a dual role in protecting against oxidative stress and in modulating cell proliferation.


Subject(s)
Cell Division/drug effects , Epithelial Cells/cytology , Magnesium Deficiency/pathology , Magnesium/pharmacology , Oxidative Stress/drug effects , Cell Division/physiology , Cell Line , Comet Assay , DNA Damage , Dose-Response Relationship, Drug , G1 Phase/drug effects , G1 Phase/physiology , Gene Expression Profiling , Glutathione Transferase/metabolism , Humans , Magnesium Deficiency/physiopathology , Oligonucleotide Array Sequence Analysis , Oxidative Stress/physiology , Reactive Oxygen Species , Resting Phase, Cell Cycle/drug effects , Resting Phase, Cell Cycle/physiology , Up-Regulation
19.
Magnes Res ; 22(1): 5-9, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19441269

ABSTRACT

Over recent decades there have been several papers that documented hypomagnesaemia*, in cancer patients treated, with cisplatin, with combined chemotherapies and more recently, with cetuximab an antibody against the epidermal growth factor receptor. Recently, however, the clinical read-out of cetuximab-induced hypomagnesaemia has received different interpretations. Some reports called the readers' attention to the importance of magnesium supplementation in relieving patient's discomfort or preventing the most severe complications of hypomagnesaemia. Other reports claimed that magnesium deficiency could contribute to the oncologic efficacy of cetuximab. This latter interpretation implies that the decision on magnesium supplementation should consider the pros and cons of returning magnesium to normal levels. Given that decreased magnesium availability inhibits cell proliferation, hypomagnesaemia may slow down tumor growth. Unfortunately, one view does not fit all. We think it important to recapitulate our knowledge on the effects of magnesium on tumor growth, angiogenesis, invasion and metastatization with the aim of providing clinical oncologists with an overview of available data of the potential effects of hypomagnesaemia in tumor growth. Translating these results into clinical settings may help in designing suitable studies to better evaluate the consequences of hypomagnesaemia in cancer patients.


Subject(s)
Antineoplastic Agents/adverse effects , Magnesium Deficiency/chemically induced , Magnesium/blood , Neoplasms/blood , Animals , Antibodies, Monoclonal/adverse effects , Antibodies, Monoclonal, Humanized , Cetuximab , Humans , Magnesium Deficiency/drug therapy , Neoplasms/drug therapy
20.
Cell Calcium ; 83: 102078, 2019 11.
Article in English | MEDLINE | ID: mdl-31493712

ABSTRACT

Derangement of magnesium homeostasis underlies the pathophysiology of many diseases, including cancer. Recent advances support the view that aberrant expression of Mg2+ channels and other Mg2+ homeostatic factors may affect many hallmarks of cancer. The seminal idea of magnesium as a key regulator of cell proliferation has been enriched by novel intriguing findings that link magnesium and Mg2+ transporters to distinctive and complementary capabilities that enable tumour growth and metastatic dissemination. In this review, we examine the evidence on the involvement of members from the TRPM, CNNM and SCL41 protein families in cancer progression, and discuss their potential as therapeutic targets.


Subject(s)
Biomarkers, Tumor/metabolism , Cell Membrane/metabolism , Neoplasms/metabolism , Transient Receptor Potential Channels/metabolism , Animals , Cell Proliferation , Homeostasis , Humans , Protein Conformation , Protein Domains/genetics , Structure-Activity Relationship
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