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1.
Minerva Surg ; 78(6): 692-709, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37705391

ABSTRACT

The last three decades of literature in trauma have been erroneously hammered by the belief the lethal triad (LT) of acidosis, hypothermia and coagulopathy was, as claimed originally, the statutory rationale underlying for the application of damage control surgery (DCS) strategy. As a matter of fact, the LT is not all lethal: only acidosis is lethal and a reliable hard sign for DCS, indicating severe levels of hypoxemia and tissues hypoxia. The mainstream flow of events leading to exitus in hemorragic shock pass through macro and microcirculation dynamics, oxygen, acidosis, and ischemia-reperfusion toxemia. It is solely by interfering or manipulating these variables dynamics that we can decrease morbidity and mortality. A solid synoptic list of the indications and timing of DCS has been elaborated.


Subject(s)
Acidosis , Blood Coagulation Disorders , Hypothermia , Pre-Eclampsia , Female , Humans , Hypothermia/etiology , Ischemia
2.
Minerva Cardiol Angiol ; 71(1): 44-50, 2023 Feb.
Article in English | MEDLINE | ID: mdl-35212503

ABSTRACT

BACKGROUND: The optimal timing of PCI for NSTE-ACS with CKD is unclear. The aim of our study was to assess whether early percutaneous coronary intervention (PCI) (within 24 hours from admission) is associated with improved in-hospital (mortality or acute kidney injury) and long-term events (composite of mortality, myocardial infarction, stroke and bleeding events) in patients with non-ST-elevation acute coronary syndromes (NSTE-ACS) with chronic kidney disease (CKD). METHODS: We retrospectively studied NSTE-ACS patients who underwent PCI in large tertiary centers. CKD was defined as estimated glomerular filtration rate (eGFR)<60 mL/min/1.73 m2. A propensity score for the likelihood of an early invasive strategy was calculated. Relative risks (RR) and adjusted hazard ratios (HR) were estimated for in-hospital and follow-up events. RESULTS: We included 821 patients, mean age was 69±12 years; 492 (60%) received an early PCI, and 273 (33%) had an eGFR <60. Median follow-up was 391 days. At univariate analysis, early treatment was associated with significantly lower in-hospital and follow-up events. However, after adjustment for major prognostic factors, there was no significant association with both in-hospital (RR=1.06; 95% CI 0.83-1.36) and follow-up events (RR=1.07; 95% CI 0.83-1.37). When the association was assessed in strata of CKD, lack of statistically significant association was confirmed, even if a trend emerged in patients with preserved renal function both on primary outcome (RR=0.47, 95% 0.18-1.22) and time to secondary outcome (HR=0.62, 95% CI 0.36-1.08). CONCLUSIONS: In conclusion in a cohort of NSTE-ACS patients, an early invasive strategy does not independently affect prognosis.


Subject(s)
Acute Coronary Syndrome , Percutaneous Coronary Intervention , Renal Insufficiency, Chronic , Humans , Middle Aged , Aged , Aged, 80 and over , Prognosis , Acute Coronary Syndrome/surgery , Percutaneous Coronary Intervention/adverse effects , Retrospective Studies , Renal Insufficiency, Chronic/complications
3.
J Clin Med ; 12(1)2022 Dec 29.
Article in English | MEDLINE | ID: mdl-36615060

ABSTRACT

Hemorrhagic shock (HS) management is based on a timely, rapid, definitive source control of bleeding/s and on blood loss replacement. Stopping the hemorrhage from progressing from any named and visible vessel is the main stem fundamental praxis of efficacy and effectiveness and an essential, obligatory, life-saving step. Blood loss replacement serves the purpose of preventing ischemia/reperfusion toxemia and optimizing tissue oxygenation and microcirculation dynamics. The "physiological classification of HS" dictates the timely management and suits the 'titrated hypotensive resuscitation' tactics and the 'damage control surgery' strategy. In any hypotensive but not yet critical shock, the body's response to a fluid load test determines the cut-off point between compensation and progression between the time for adopting conservative treatment and preparing for surgery or rushing to the theater for rapid bleeding source control. Up to 20% of the total blood volume is given to refill the unstressed venous return volume. In any critical level of shock where, ab initio, the patient manifests signs indicating critical physiology and impending cardiac arrest or cardiovascular accident, the balance between the life-saving reflexes stretched to the maximum and the insufficient distal perfusion (blood, oxygen, and substrates) remains in a liable and delicate equilibrium, susceptible to any minimal change or interfering variable. In a cardiac arrest by exsanguination, the core of the physiological issue remains the rapid restoration of a sufficient venous return, allowing the heart to pump it back into systemic circulation either by open massage via sternotomy or anterolateral thoracotomy or spontaneously after aorta clamping in the chest or in the abdomen at the epigastrium under extracorporeal resuscitation and induced hypothermia. This is the only way to prevent ischemic damage to the brain and the heart. This is accomplishable rapidly and efficiently only by a direct approach, which is a crush laparotomy if the bleeding is coming from an abdominal +/- lower limb site or rapid sternotomy/anterolateral thoracotomy if the bleeding is coming from a chest +/- upper limbs site. Without first stopping the bleeding and refilling the heart, any further exercise is doomed to failure. Direct source control via laparotomy/thoracotomy, with the concomitant or soon following venous refilling, are the two essential, initial life-saving steps.

5.
Proc Natl Acad Sci U S A ; 117(1): 752-760, 2020 01 07.
Article in English | MEDLINE | ID: mdl-31871183

ABSTRACT

Arabidopsis thaliana glutamate receptor-like (GLR) channels are amino acid-gated ion channels involved in physiological processes including wound signaling, stomatal regulation, and pollen tube growth. Here, fluorescence microscopy and genetics were used to confirm the central role of GLR3.3 in the amino acid-elicited cytosolic Ca2+ increase in Arabidopsis seedling roots. To elucidate the binding properties of the receptor, we biochemically reconstituted the GLR3.3 ligand-binding domain (LBD) and analyzed its selectivity profile; our binding experiments revealed the LBD preference for l-Glu but also for sulfur-containing amino acids. Furthermore, we solved the crystal structures of the GLR3.3 LBD in complex with 4 different amino acid ligands, providing a rationale for how the LBD binding site evolved to accommodate diverse amino acids, thus laying the grounds for rational mutagenesis. Last, we inspected the structures of LBDs from nonplant species and generated homology models for other GLR isoforms. Our results establish that GLR3.3 is a receptor endowed with a unique amino acid ligand profile and provide a structural framework for engineering this and other GLR isoforms to investigate their physiology.


Subject(s)
Amino Acids/metabolism , Arabidopsis Proteins/ultrastructure , Arabidopsis/metabolism , Protein Domains/genetics , Receptors, Glutamate/ultrastructure , Arabidopsis/genetics , Arabidopsis Proteins/agonists , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Binding Sites/genetics , Calcium/metabolism , Crystallography, X-Ray , Cytosol/metabolism , Ligands , Mutation , Plant Roots/metabolism , Plants, Genetically Modified , Receptors, Glutamate/genetics , Receptors, Glutamate/metabolism , Seedlings/metabolism , Structure-Activity Relationship
6.
Plant Physiol ; 179(4): 1754-1767, 2019 04.
Article in English | MEDLINE | ID: mdl-30696750

ABSTRACT

Phosphate (Pi) deficiency strongly limits plant growth, and plant roots foraging the soil for nutrients need to adapt to optimize Pi uptake. Ca2+ is known to signal in root development and adaptation but has to be tightly controlled, as it is highly toxic to Pi metabolism. Under Pi starvation and the resulting decreased cellular Pi pool, the use of cytosolic free Ca2+ ([Ca2+]cyt) as a signal transducer may therefore have to be altered. Employing aequorin-expressing Arabidopsis (Arabidopsis thaliana), we show that Pi starvation, but not nitrogen starvation, strongly dampens the [Ca2+]cyt increases evoked by mechanical, salt, osmotic, and oxidative stress as well as by extracellular nucleotides. The altered root [Ca2+]cyt response to extracellular ATP manifests during seedling development under chronic Pi deprivation but can be reversed by Pi resupply. Employing ratiometric imaging, we delineate that Pi-starved roots have a normal response to extracellular ATP at the apex but show a strongly dampened [Ca2+]cyt response in distal parts of the root tip, correlating with high reactive oxygen species levels induced by Pi starvation. Excluding iron, as well as Pi, rescues this altered [Ca2+]cyt response and restores reactive oxygen species levels to those seen under nutrient-replete conditions. These results indicate that, while Pi availability does not seem to be signaled through [Ca2+]cyt, Pi starvation strongly affects stress-induced [Ca2+]cyt signatures. These data reveal how plants can integrate nutritional and environmental cues, adding another layer of complexity to the use of Ca2+ as a signal transducer.


Subject(s)
Arabidopsis/metabolism , Calcium/metabolism , Phosphates/metabolism , Stress, Physiological , Arabidopsis Proteins/metabolism , Nitrogen/metabolism , Plant Roots/metabolism , Reactive Oxygen Species/metabolism , Signal Transduction
7.
Proc Natl Acad Sci U S A ; 115(15): 3966-3971, 2018 04 10.
Article in English | MEDLINE | ID: mdl-29581277

ABSTRACT

Ca2+ signals in plant cells are important for adaptive responses to environmental stresses. Here, we report that the Arabidopsis CATION/Ca2+ EXCHANGER2 (CCX2), encoding a putative cation/Ca2+ exchanger that localizes to the endoplasmic reticulum (ER), is strongly induced by salt and osmotic stresses. Compared with the WT, AtCCX2 loss-of-function mutant was less tolerant to osmotic stress and displayed the most noteworthy phenotypes (less root/shoot growth) during salt stress. Conversely, AtCCX2 gain-of-function mutants were more tolerant to osmotic stress. In addition, AtCCX2 partially suppresses the Ca2+ sensitivity of K667 yeast triple mutant, characterized by Ca2+ uptake deficiency. Remarkably, Cameleon Ca2+ sensors revealed that the absence of AtCCX2 activity results in decreased cytosolic and increased ER Ca2+ concentrations in comparison with both WT and the gain-of-function mutants. This was observed in both salt and nonsalt osmotic stress conditions. It appears that AtCCX2 is directly involved in the control of Ca2+ fluxes between the ER and the cytosol, which plays a key role in the ability of plants to cope with osmotic stresses. To our knowledge, Atccx2 is unique as a plant mutant to show a measured alteration in ER Ca2+ concentrations. In this study, we identified the ER-localized AtCCX2 as a pivotal player in the regulation of ER Ca2+ dynamics that heavily influence plant growth upon salt and osmotic stress.


Subject(s)
Antiporters/metabolism , Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Calcium/metabolism , Cytosol/metabolism , Endoplasmic Reticulum/metabolism , Antiporters/genetics , Arabidopsis/genetics , Arabidopsis Proteins/genetics , Endoplasmic Reticulum/genetics , Gene Expression Regulation, Plant , Osmotic Pressure , Protein Transport , Signal Transduction
8.
Eur Rev Med Pharmacol Sci ; 22(1): 217-222, 2018 01.
Article in English | MEDLINE | ID: mdl-29364490

ABSTRACT

OBJECTIVE: Pain relief is a very important aspect in Pediatrician's clinical practice. It is often thought that young children, particularly infants, do not perceive as much pain as adults because of their immature nervous system and that untreated pain would not have adverse long-term consequences. Instead, it has been demonstrated that infants and children experience pain in a similar manner to adults. Many factors, particularly emotional factors, can increase the child's pain perception. Children live with anxiety even minor procedures. This suggests the need for an adequate sedation and the way of sedation should be free of pain itself. We believe the route to be followed may be the intranasal (IN) administration of sedative drugs. MATERIALS AND METHODS: We have conducted a brief review of the literature by Pubmed about the most commonly used sedative drugs: sufentanyl, fentanyl, midazolam, ketamine, nitrous oxide and dexmedetomidine. We have investigated in the literature the type of administration of IN drugs: drop instillation or by a mucosal atomizer device (MAD). RESULTS: In our study, it was noted that IN drugs administration is an effective and safe method to reduce anxiety and to deliver analgesia because it is practical and non-invasive. Moreover, therapeutic levels of sedatives are low due to the presence of a rich vascular plexus in the nasal cavity, which communicates with the subarachnoid space via the olfactory nerve and reduce the time of medication delivery, that is, the onset of action. The use of MAD even gives as better bioavailability of drugs. CONCLUSIONS: IN sedation via MAD is effective and safe and should be one of the first choices for procedural sedation in children.


Subject(s)
Anxiety/prevention & control , Hypnotics and Sedatives/administration & dosage , Administration, Intranasal , Emergency Service, Hospital , Humans , Ketamine/administration & dosage , Midazolam/administration & dosage , Nebulizers and Vaporizers , Sufentanil/administration & dosage
9.
Plant Cell Physiol ; 58(7): 1161-1172, 2017 Jul 01.
Article in English | MEDLINE | ID: mdl-28379562

ABSTRACT

Calcium oscillations play a role in the regulation of the development of tip-growing plant cells. Using optical microscopy, calcium oscillations have been observed in a few systems (e.g. pollen tubes, fungal hyphae and algal rhizoids). High-resolution, non-phototoxic and rapid imaging methods are required to study the calcium oscillation in root hairs. We show that light sheet fluorescence microscopy is optimal to image growing root hairs of Arabidopsis thaliana and to follow their oscillatory tip-focused calcium gradient. We describe a protocol for performing live imaging of root hairs in seedlings expressing the cytosol-localized ratiometric calcium indicator Yellow Cameleon 3.6. Using this protocol, we measured the calcium gradient in a large number of root hairs. We characterized their calcium oscillations and correlated them with the rate of hair growth. The method was then used to screen the effect of auxin on the properties of the growing root hairs.


Subject(s)
Arabidopsis/cytology , Calcium Signaling , Microscopy, Fluorescence/methods , Arabidopsis/growth & development , Arabidopsis/physiology , Calmodulin/metabolism , Cytosol/metabolism , Luminescent Proteins/metabolism , Plant Roots/cytology , Plant Roots/growth & development , Plant Roots/physiology , Recombinant Fusion Proteins/metabolism
10.
Curr Pediatr Rev ; 12(4): 301-310, 2016.
Article in English | MEDLINE | ID: mdl-27634538

ABSTRACT

Child maltreatment is a complex life experience occurs when a parent or caregiver does an intentional or potential damage to a child, including acts of commission and omission. Child abuse is not an uncommon event, but it is not always recognized. Identifying the real number of maltreated children is a challenge because of the large variability in reported prevalence data across studies. Unfortunately, in the United States, it affects 1 in 8 children, by the age of 18 years, annually. Paediatricians may encounter a variety of forms of maltreatment such as neglect, emotional, physical and sexual abuse. These aspects should be recognised, examined and evaluated by employing a systematic approach and focusing on basic needs of children that may not be met. Child maltreatment is a global problem with serious life-long physical and psychological or psychiatric outcomes. It is associated with important economic and social costs (such as physical and mental health, productivity losses, child welfare, criminal justice and special education costs) due to its high prevalence and its long-term and short-term consequences. In the United States, the average cost of nonfatal maltreatment is $210,012 per children and the cost of fatal maltreatment is $1,272,900. General Practitioners are quite prepared to face the problem of child maltreatment: since they have the opportunity to meet several members of the same family, they can detect stressors that put children at risk of maltreatment. All health professionals have the responsibility to protect children from abuse and neglect.


Subject(s)
Child Abuse , Mental Health , Neurodevelopmental Disorders/etiology , Caregivers , Child , Female , Humans , Male , Neurodevelopmental Disorders/epidemiology , Prevalence , United States
11.
Heart Vessels ; 31(5): 722-33, 2016 May.
Article in English | MEDLINE | ID: mdl-25735775

ABSTRACT

There is a paucity of data about mid-term outcome of patients with advanced heart failure (HF) treated with left ventricular assist device (LVAD) in Europe, where donor shortage and their aging limit the availability and the probability of success of heart transplantation (HTx). The aim of this study is to compare Italian single-centre mid-term outcome in prospective patients treated with LVAD vs. HTx. We evaluated 213 consecutive patients with advanced HF who underwent continuous-flow LVAD implant or HTx from 1/2006 to 2/2012, with complete follow-up at 1 year (3/2013). We compared outcome in patients who received a LVAD (n = 49) with those who underwent HTx (n = 164) and in matched groups of 39 LVAD and 39 HTx patients. Patients that were treated with LVAD had a worse risk profile in comparison with HTx patients. Kaplan-Meier survival curves estimated a one-year survival of 75.5 % in LVAD vs. 82.3 % in HTx patients, a difference that was non-statistically significant [hazard ratio (HR) 1.46; 95 % confidence interval (CI) 0.74-2.86; p = 0.27 for LVAD vs. HTx]. After group matching 1-year survival was similar between LVAD (76.9 %) and HTx (79.5 %; HR 1.15; 95 % CI 0.44-2.98; p = 0.78). Concordant data was observed at 2-year follow-up. Patients treated with LVAD as bridge-to-transplant indication (n = 22) showed a non significant better outcome compared with HTx with a 95.5 and 90.9 % survival, at 1- and 2-year follow-up, respectively. Despite worse preoperative conditions, survival is not significantly lower after LVAD than after HTx at 2-year follow-up. Given the scarce number of donors for HTx, LVAD therapy represents a valid option, potentially affecting the current allocation strategy of heart donors also in Europe.


Subject(s)
Heart Failure/therapy , Heart Transplantation , Heart-Assist Devices , Ventricular Function, Left , Adult , Female , Heart Failure/diagnosis , Heart Failure/mortality , Heart Failure/physiopathology , Heart Transplantation/adverse effects , Heart Transplantation/mortality , Heart-Assist Devices/adverse effects , Humans , Italy , Kaplan-Meier Estimate , Male , Middle Aged , Proportional Hazards Models , Prospective Studies , Prosthesis Design , Risk Factors , Time Factors , Treatment Outcome
12.
Plant Cell ; 27(11): 3190-212, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26530087

ABSTRACT

Plant organelle function must constantly adjust to environmental conditions, which requires dynamic coordination. Ca(2+) signaling may play a central role in this process. Free Ca(2+) dynamics are tightly regulated and differ markedly between the cytosol, plastid stroma, and mitochondrial matrix. The mechanistic basis of compartment-specific Ca(2+) dynamics is poorly understood. Here, we studied the function of At-MICU, an EF-hand protein of Arabidopsis thaliana with homology to constituents of the mitochondrial Ca(2+) uniporter machinery in mammals. MICU binds Ca(2+) and localizes to the mitochondria in Arabidopsis. In vivo imaging of roots expressing a genetically encoded Ca(2+) sensor in the mitochondrial matrix revealed that lack of MICU increased resting concentrations of free Ca(2+) in the matrix. Furthermore, Ca(2+) elevations triggered by auxin and extracellular ATP occurred more rapidly and reached higher maximal concentrations in the mitochondria of micu mutants, whereas cytosolic Ca(2+) signatures remained unchanged. These findings support the idea that a conserved uniporter system, with composition and regulation distinct from the mammalian machinery, mediates mitochondrial Ca(2+) uptake in plants under in vivo conditions. They further suggest that MICU acts as a throttle that controls Ca(2+) uptake by moderating influx, thereby shaping Ca(2+) signatures in the matrix and preserving mitochondrial homeostasis. Our results open the door to genetic dissection of mitochondrial Ca(2+) signaling in plants.


Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Calcium-Binding Proteins/metabolism , EF Hand Motifs , Mitochondria/metabolism , Arabidopsis/genetics , Calcium , Calcium Signaling , Cell Respiration , Cytosol/metabolism , DNA, Bacterial/genetics , Mitochondria/ultrastructure , Mutagenesis, Insertional/genetics , Phylogeny , Plant Roots/metabolism , Plant Roots/ultrastructure , Protein Binding , Protein Transport , Seedlings/metabolism , Sequence Homology, Amino Acid , Subcellular Fractions/metabolism
13.
Urol Int ; 92(2): 223-9, 2014.
Article in English | MEDLINE | ID: mdl-24246887

ABSTRACT

BACKGROUND: Nocturnal enuresis (NE) is a very common pediatric disorder. The aim of this study was to evaluate the characteristics of patients with NE or urinary incontinence (UI) during a period of 5 years to increase the knowledge on these conditions and optimize their diagnosis and treatment. METHODS: We enrolled 278 children with NE or UI referred to the pediatric nephrology ambulatory, 'A. Gemelli' University Hospital of Rome, from December 2006 to December 2011. RESULTS: We observed that heredity, parasomnias, left-handedness, polythelia and constipation are correlated to NE and UI. CONCLUSIONS: We wanted to clarify the definition of NE and UI and describe our experience on the main characteristics of these conditions by referring to the latest knowledge reported in the literature.


Subject(s)
Nocturnal Enuresis/diagnosis , Nocturnal Enuresis/therapy , Urinary Incontinence/diagnosis , Urinary Incontinence/therapy , Adolescent , Child , Child, Preschool , Diagnosis, Differential , Female , Humans , Male , Nephrology , Pediatrics , Reproducibility of Results , Treatment Outcome
14.
Genet Mol Res ; 12(2): 1731-9, 2013 May 21.
Article in English | MEDLINE | ID: mdl-23765979

ABSTRACT

DNA was recovered from teeth of 2 great ape skeletons, Pan troglodytes (Ptr) and Pongo pygmaeus (Ppy), belonging to a 19th-century zoological collection. The skeletons presented morphological alterations possibly associated with ß-thalassemia: Ptr had deformation of the calvaria and oro-maxillo-facial bones with porotic hyperostosis and extended osteoporotic lesions of the skeleton, while Ppy showed a general marked widening of the calvarial diploe but moderate osteoporotic signs on the post-cranial skeleton. We screened Ptr and Ppy for mutations in the ß-globin gene (exons 1, 2, and 3) because we suspected thalassemia. Ptr ß-globin sequences showed the highest degree of similarity with the human ones (99.8%), while those of Ppy were slightly different (98.2%). The results were consistent with the phylogenetic relationships between their β-globin gene sequences. We did not find any mutation in the ß-globin gene of Ptr and Ppy; therefore, we conclude that, in spite of skeletal alterations, the 2 subjects analyzed were not affected by ß-thalassemia.


Subject(s)
DNA/genetics , Pan troglodytes/genetics , Pongo pygmaeus/genetics , beta-Globins/genetics , beta-Thalassemia/genetics , Amino Acid Sequence , Animals , Base Sequence , Bone and Bones/pathology , Electrophoresis, Agar Gel , Exons/genetics , Humans , Likelihood Functions , Molecular Sequence Data , Phylogeny , Sequence Alignment , Skull/pathology , beta-Globins/chemistry
15.
J Clin Invest ; 123(2): 646-56, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23281397

ABSTRACT

Progressive loss of visual function frequently accompanies demyelinating diseases such as multiple sclerosis (MS) and is hypothesized to be the result of damage to the axons and soma of neurons. Here, we show that dendritic impairment is also involved in these diseases. Deimination, a posttranslational modification, was reduced in the retinal ganglion cell layer of MS patients and in a transgenic mouse model of MS (ND4 mice). Reduced deimination accompanied a decrease in inner retinal function in ND4 mice, indicating loss of vision. Local restoration of deimination dramatically improved retinal function and elongation of neurites in isolated neurons. Further, neurite length was decreased by downregulation of deimination or siRNA knockdown of the export-binding protein REF, a primary target for deimination in these cells. REF localized to dendrites and bound selective mRNAs and translation machinery to promote protein synthesis. Thus, protein deimination and dendritic outgrowth play key roles in visual function and may be a general feature of demyelinating diseases.


Subject(s)
Demyelinating Diseases/complications , Demyelinating Diseases/physiopathology , Retina/physiopathology , Vision Disorders/etiology , Vision Disorders/physiopathology , Aged , Amino Acid Sequence , Animals , Demyelinating Diseases/genetics , Disease Models, Animal , Gene Knockdown Techniques , Humans , Male , Mice , Mice, Transgenic , Molecular Sequence Data , Multiple Sclerosis/complications , Multiple Sclerosis/physiopathology , Nuclear Proteins/antagonists & inhibitors , Nuclear Proteins/chemistry , Nuclear Proteins/genetics , Nuclear Proteins/physiology , Protein Processing, Post-Translational , RNA-Binding Proteins/antagonists & inhibitors , RNA-Binding Proteins/chemistry , RNA-Binding Proteins/genetics , RNA-Binding Proteins/physiology , Retina/pathology , Retinal Ganglion Cells/pathology , Retinal Ganglion Cells/physiology , Transcription Factors/antagonists & inhibitors , Transcription Factors/chemistry , Transcription Factors/genetics , Transcription Factors/metabolism , Transcription Factors/physiology , Vision Disorders/genetics , Vision, Ocular
16.
Dis Model Mech ; 6(2): 467-78, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23118341

ABSTRACT

Multiple sclerosis (MS) is the most common CNS-demyelinating disease of humans, showing clinical and pathological heterogeneity and a general resistance to therapy. We first discovered that abnormal myelin hypercitrullination, even in normal-appearing white matter, by peptidylarginine deiminases (PADs) correlates strongly with disease severity and might have an important role in MS progression. Hypercitrullination is known to promote focal demyelination through reduced myelin compaction. Here we report that 2-chloroacetamidine (2CA), a small-molecule, PAD active-site inhibitor, dramatically attenuates disease at any stage in independent neurodegenerative as well as autoimmune MS mouse models. 2CA reduced PAD activity and protein citrullination to pre-disease status. In the autoimmune models, disease induction uniformly induced spontaneous hypercitrullination with citrulline+ epitopes targeted frequently. 2CA rapidly suppressed T cell autoreactivity, clearing brain and spinal cord infiltrates, through selective removal of newly activated T cells. 2CA essentially prevented disease when administered before disease onset or before autoimmune induction, making hypercitrullination, and specifically PAD enzymes, a therapeutic target in MS models and thus possibly in MS.


Subject(s)
Citrulline/metabolism , Hydrolases/antagonists & inhibitors , Multiple Sclerosis/enzymology , Multiple Sclerosis/pathology , Amidines/chemistry , Amidines/pharmacology , Amidines/therapeutic use , Animals , Brain/enzymology , Brain/pathology , CD3 Complex/metabolism , Demyelinating Diseases/enzymology , Demyelinating Diseases/pathology , Disease Models, Animal , Encephalomyelitis, Autoimmune, Experimental/drug therapy , Encephalomyelitis, Autoimmune, Experimental/enzymology , Encephalomyelitis, Autoimmune, Experimental/pathology , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Enzyme Inhibitors/therapeutic use , Humans , Hydrolases/metabolism , Lymphocytes/drug effects , Lymphocytes/pathology , Mice , Mice, Inbred C57BL , Mice, Transgenic , Multiple Sclerosis/drug therapy , Optic Nerve/drug effects , Optic Nerve/pathology , Optic Nerve/ultrastructure , Protein-Arginine Deiminases , Spleen/drug effects , Spleen/metabolism , Spleen/pathology , Survival Analysis
17.
Dis Model Mech ; 1(4-5): 229-40, 2008.
Article in English | MEDLINE | ID: mdl-19093029

ABSTRACT

Demyelination in the central nervous system is the hallmark feature in multiple sclerosis (MS). The mechanism resulting in destabilization of myelin is a complex multi-faceted process, part of which involves deimination of myelin basic protein (MBP). Deimination, the conversion of protein-bound arginine to citrulline, is mediated by the peptidylarginine deiminase (PAD) family of enzymes, of which the PAD2 and PAD4 isoforms are present in myelin. To test the hypothesis that PAD contributes to destabilization of myelin in MS, we developed a transgenic mouse line (PD2) containing multiple copies of the cDNA encoding PAD2, under the control of the MBP promoter. Using previously established criteria, clinical signs were more severe in PD2 mice than in their normal littermates. The increase in PAD2 expression and activity in white matter was demonstrated by immunohistochemistry, reverse transcriptase-PCR, enzyme activity assays, and increased deimination of MBP. Light and electron microscopy revealed more severe focal demyelination and thinner myelin in the PD2 homozygous mice compared with heterozygous PD2 mice. Quantitation of the disease-associated molecules GFAP and CD68, as measured by immunoslot blots, were indicative of astrocytosis and macrophage activation. Concurrently, elevated levels of the pro-inflammatory cytokine TNF-alpha and nuclear histone deimination support initiation of demyelination by increased PAD activity. These data support the hypothesis that elevated PAD levels in white matter represents an early change that precedes demyelination.


Subject(s)
Central Nervous System/pathology , Hydrolases/metabolism , Myelin Sheath/pathology , Animals , Hydrolases/genetics , Mice , Mice, Transgenic , Microscopy, Electron, Transmission , Phenotype , Protein-Arginine Deiminases , RNA, Messenger/genetics , Tumor Necrosis Factor-alpha/metabolism
18.
Lab Invest ; 88(4): 354-64, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18227806

ABSTRACT

An understanding of the structure and composition of the myelin sheath is essential to understand the pathogenesis of demyelinating diseases such as multiple sclerosis (MS). The presence of citrulline in myelin proteins in particular myelin basic protein (MBP) causes an important change in myelin structure, which destabilizes myelin. The peptidylarginine deiminases (PADs) are responsible for converting arginine in proteins to citrulline. Two of these, PAD2 and PAD4, were localized to the myelin sheath by immunogold electron microscopy. Deimination of MBP by the recombinant forms of these enzymes showed that it was extensive, that is, PAD2 deiminated 18 of 19 arginyl residues in MBP, whereas PAD4 deiminated 14 of 19 residues. In the absence of PAD2 (the PAD2-knockout mouse) PAD4 remained active with limited deimination of arginyl residues. In myelin isolated from patients with MS, the amounts of both PAD2 and PAD4 enzymes were increased compared with that in normals, and the citrullinated proteins were also increased. These data support the view that an increase in citrullinated proteins resulting from increased PAD2 and 4 is an important change in the pathogenesis of MS.


Subject(s)
Citrulline/biosynthesis , Hydrolases/metabolism , Myelin Basic Protein/metabolism , Myelin Sheath/enzymology , Animals , Arginine/metabolism , Blotting, Western , Brain/metabolism , Humans , Immunohistochemistry , Mice , Mice, Knockout , Phosphatidylcholines/metabolism , Phosphatidylserines/metabolism , Protein-Arginine Deiminase Type 2 , Protein-Arginine Deiminase Type 4 , Protein-Arginine Deiminases
19.
J Neurosci Res ; 85(9): 2006-16, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17469138

ABSTRACT

In previous studies, we documented increased citrullinated myelin basic protein (MBP) was present in MBP isolated from multiple sclerosis (MS) normal appearing white matter (NAWM). This increase was due to the myelin enzyme peptidyl argininedeiminase 2 (PAD2). In this study, we show that methylation of cytosine of the PAD2 promoter in DNA from MS NAWM was decreased to one-third of the level of that in DNA from normal white matter. The PAD2 promoter in DNA from thymus obtained from the same MS patients and white matter DNA from Alzheimer's, Huntington's, and Parkinson's was not hypomethylated. DNA demethylase activity in supernatants prepared from NAWM of MS patients was 2-fold higher than the DNA demethylase from normal, Alzheimer's, Huntington's and Parkinson's disease white matter. The amount of PAD2 enzyme and citrullinated MBP was increased in MS NAWM. The decreased methylation of cytosines in the PAD2 promoter may explain the increased synthesis of PAD2 protein that is responsible for the increased amount of citrullinated MBP, which in turn results in loss of myelin stability in MS brain.


Subject(s)
Brain/enzymology , CpG Islands/physiology , Hydrolases/metabolism , Multiple Sclerosis/enzymology , 5-Methylcytosine/metabolism , Blotting, Western , Citrulline/metabolism , DNA/biosynthesis , DNA/genetics , DNA, Single-Stranded/metabolism , Fluorescent Antibody Technique , Humans , Methylation , Myelin Basic Protein/metabolism , Promoter Regions, Genetic/genetics , Protein-Arginine Deiminase Type 2 , Protein-Arginine Deiminases , Reverse Transcriptase Polymerase Chain Reaction , Sulfites/pharmacology , Thymus Gland/metabolism
20.
Neurochem Res ; 32(2): 251-6, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17031564

ABSTRACT

The pathogenesis of MS is unknown. In our studies, we have demonstrated an important role for citrullinated myelin basic protein (MBP). The accompanying loss of positive charge compromises the ability of MBP to interact with the lipid bilayer. The conversion of arginine to citrulline in brain is carried out by an enzyme peptidyl arginine deiminase (PAD) 2. The amount of PAD 2 in brain was increased in MS normal-appearing white matter. The mechanism responsible for this increase involved hypomethylation of the promoter region in the PAD 2 gene in MS, but no change (compared to normal) was found in thymus tissue DNA from the same MS patients. In addition, no change was observed in other neurological diseases, including Alzheimer's, Parkinson's, and Huntington's. We propose that citrullinated MBP, resulting from elevated levels of PAD 2 represents an important biochemical pathway in the pathogenesis of MS.


Subject(s)
Citrulline/physiology , Multiple Sclerosis/etiology , Myelin Basic Protein/metabolism , Apoptosis , Humans , Hydrolases/metabolism , Methylation , Multiple Sclerosis/enzymology , Oligodendroglia/physiology , Protein Conformation/drug effects , Protein Processing, Post-Translational , Protein-Arginine Deiminases
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