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1.
Emerg Infect Dis ; 29(4): 850-852, 2023 04.
Article in English | MEDLINE | ID: mdl-36878013

ABSTRACT

We describe an unusual outbreak of respiratory infections caused by human metapneumovirus in children during the sixth wave of COVID-19 in Spain, associated with the Omicron variant. Patients in this outbreak were older than usual and showed more hypoxia and pneumonia, longer length of stay, and greater need for intensive care.


Subject(s)
COVID-19 , Metapneumovirus , Paramyxoviridae Infections , Respiratory Tract Infections , Child , Humans , COVID-19/epidemiology , SARS-CoV-2 , Spain/epidemiology , Pandemics , Paramyxoviridae Infections/epidemiology , Respiratory Tract Infections/epidemiology
2.
J Clin Rheumatol ; 29(5): e59-e70, 2023 Aug 01.
Article in English | MEDLINE | ID: mdl-37005371

ABSTRACT

OBJECTIVE: The aim of this study was to provide an evidence-based framework to guide health care professionals treating patients under glucocorticoid (GC) therapy and develop guidelines for the prevention and treatment of glucocorticoid-induced osteoporosis (GIO) in postmenopausal women and men aged ≥50 years. METHODS: An expert panel on bone diseases designed a series of clinically meaningful questions following the PICO (Population, Intervention, Comparator, and Outcome) structure. Using GRADE (Grading of Recommendations Assessment, Development, and Evaluation) methodology, we made a systematic literature review, extracted and summarized the effect estimates, and graded the quality of the evidence. The expert panel voted each PICO question and made recommendations after reaching an agreement of at least 70%. RESULTS: Seventeen recommendations (9 strong and 8 conditional) and 8 general principles were developed for postmenopausal women and men aged ≥50 years under GC treatment. Bone mineral density (BMD), occurrence of fragility fractures, probability of fracture at 10 years by Fracture Risk Assessment Tool, and other screening factors for low BMD are recommended for patient evaluation and stratification according to fragility fracture risk. The treatment of patients under GC therapy should include counseling on lifestyle habits and strict control of comorbidities. The goal of GIO treatment is the nonoccurrence of new fragility fractures as well as to increase or maintain BMD in certain clinical situations. This was considered for the therapeutic approach in different clinical scenarios. CONCLUSIONS: This GIO guideline provides evidence-based guidance for health care providers treating patients.


Subject(s)
Glucocorticoids , Osteoporosis , Male , Humans , Female , Middle Aged , Aged , Glucocorticoids/therapeutic use , Postmenopause , Osteoporosis/chemically induced , Osteoporosis/diagnosis , Osteoporosis/drug therapy , Bone Density
3.
Int J Mol Sci ; 23(19)2022 Oct 04.
Article in English | MEDLINE | ID: mdl-36233066

ABSTRACT

Damage to the retinal pigment epithelium, Bruch's membrane and/or tissues underlying macula is known to increase the risk of age-related macular degeneration (AMD). AMD is commonly categorized in two distinct types, namely, the nonexudative (dry form) and the exudative (wet form). Currently, there is no ideal treatment available for AMD. Recommended standard treatments are based on the use of vascular endothelial growth factor (VEGF), with the disadvantage of requiring repeated intravitreal injections which hinder patient's compliance to the therapy. In recent years, several synthetic and natural active compounds have been proposed as innovative therapeutic strategies against this disease. There is a growing interest in the development of formulations based on nanotechnology because of its important role in the management of posterior eye segment disorders, without the use of intravitreal injections, and furthermore, with the potential to prolong drug release and thus reduce adverse effects. In the same way, 3D bioprinting constitutes an alternative to regeneration therapies for the human retina to restore its functions. The application of 3D bioprinting may change the current and future perspectives of the treatment of patients with AMD, especially those who do not respond to conventional treatment. To monitor the progress of AMD treatment and disease, retinal images are used. In this work, we revised the recent challenges encountered in the treatment of different forms of AMD, innovative nanoformulations, 3D bioprinting, and techniques to monitor the progress.


Subject(s)
Macula Lutea , Macular Degeneration , Bruch Membrane , Humans , Macula Lutea/metabolism , Macular Degeneration/drug therapy , Macular Degeneration/metabolism , Retinal Pigment Epithelium/metabolism , Vascular Endothelial Growth Factor A/metabolism
4.
Arch Virol ; 166(6): 1533-1545, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33683476

ABSTRACT

Beekeeping is a widespread activity in Argentina, mainly producing honey that has gained both national and international recognition. There are more than 3,000,000 hives in the country, mainly concentrated in Buenos Aires Province (approximately 1,000,000 hives). In recent decades, worrying rates of hive loss have been observed in many countries around the world. In Latin America, the estimated loss of hives is between 13% (Peru and Ecuador) and 53% (Chile). Argentina had annual losses of 34% for the period of October 1, 2016 to October 1, 2017. The causes of these losses are not clear but probably involve multiple stressors that can act simultaneously. One of the main causes of loss of bee colonies worldwide is infestation by the ectoparasitic mite Varroa destructor in combination with viral infections. To date, 10 viruses have been detected that affect honey bees (Apis mellifera) in Argentina. Of these, deformed wing virus, sacbrood virus, acute bee paralysis virus, chronic bee paralysis virus, and Israeli acute bee paralysis can be transmitted by mites. Deformed wing virus and the AIK complex are the viruses most often associated with loss of hives worldwide. Considering that bee viruses have been detected in Argentina in several hymenopteran and non-hymenopteran insects, these hosts could act as important natural reservoirs for viruses and play an important role in their dispersal in the environment. Further studies to investigate the different mechanisms by which viruses spread in the environment will enable us to develop various strategies for the control of infected colonies and the spread of viruses in the habitat where they are found.


Subject(s)
Bees/virology , Animals , Argentina , DNA Viruses/genetics , DNA Viruses/isolation & purification , Host-Pathogen Interactions , RNA Viruses/genetics , RNA Viruses/isolation & purification
5.
Int J Mol Sci ; 22(9)2021 May 07.
Article in English | MEDLINE | ID: mdl-34067151

ABSTRACT

Research in the pathogenesis of inflammatory skin diseases, such as skin dermatitis and psoriasis, has experienced some relevant breakthroughs in recent years. The understanding of age-related factors, gender, and genetic predisposition of these multifactorial diseases has been instrumental for the development of new pharmacological and technological treatment approaches. In this review, we discuss the molecular mechanisms behind the pathological features of psoriasis, also addressing the currently available treatments and novel therapies that are under clinical trials. Innovative therapies developed over the last 10 years have been researched. In this area, advantages of nanotechnological approaches to provide an effective drug concentration in the disease site are highlighted, together with microneedles as innovative candidates for drug delivery systems in psoriasis and other inflammatory chronic skin diseases.


Subject(s)
Nanomedicine , Psoriasis/etiology , Psoriasis/therapy , Animals , Clinical Trials as Topic , Humans , Models, Biological , Nanotechnology , Psoriasis/pathology , Psoriasis/physiopathology
7.
Planta ; 251(1): 7, 2019 Nov 27.
Article in English | MEDLINE | ID: mdl-31776669

ABSTRACT

MAIN CONCLUSION: miRNA targets from Citrus sinensis are predicted and validated using degradome data. They show an up-regulation upon infection with CPsV, with a positive correlation between target expression and symptom severity. Sweet orange (Citrus sinensis) may suffer from disease symptoms induced by virus infections, thus resulting in drastic economic losses. Infection of sweet orange plants with two isolates of citrus psorosis virus (CPsV), expressing different symptomatologies, alters the accumulation of a set of endogenous microRNAs (miRNAs). Here, we predicted ten putative targets from four down-regulated miRNAs: three belonging to the CCAAT-binding transcription factor family (CBFAs); an Ethylene-responsive transcription factor (RAP2-7); an Integrase-type DNA-binding superfamily protein (AP2B); Transport inhibitor response 1 (TIR1); GRR1-like protein 1-related (GRR1); Argonaute 2-related (AGO2), Argonaute 7 (AGO7), and a long non-coding RNA (ncRNA). We validated six of them through analysis of leaf degradome data. Expressions of the validated targets increase in infected samples compared to healthy tissue, showing a more striking up-regulation those samples with higher symptom severity. This study contributes to the understanding of the miRNA-mediated regulation of important transcripts in Citrus sinensis through target validation and shed light in the manner a virus can alter host regulatory mechanisms leading to symptom expression.


Subject(s)
Citrus sinensis/metabolism , Citrus sinensis/virology , MicroRNAs/metabolism , Plant Viruses/pathogenicity , Transcriptional Activation/genetics , Transcriptional Activation/physiology
8.
J Pediatr Gastroenterol Nutr ; 68(3): 364-370, 2019 03.
Article in English | MEDLINE | ID: mdl-30418411

ABSTRACT

OBJECTIVES: To perform long-term celiac disease (CD) screening in an HLA-DQ2 (+) cohort from the general population and to assess the influence of risk genotypes on its development. METHODS: In 2004, an HLA-DQ2 (+) cohort was selected. After the first CD screening at age 2 to 3 years, we performed a follow-up screening 8 to 10 years later. Antitransglutaminase 2 antibodies were determined using a rapid test kit. Results were confirmed by serum IgA antitransglutaminase 2 and IgA endomysial antibody determination. CD diagnosis was carried out by intestinal biopsies. Four HLA-DQ2 genotypic groups were used: G1: DQ2.5/DQ2.5 (G1A) or DQ2.5/ DQ2.2 (G1B); G2: DQ2.2/DQ7.5 (DQ2.5 trans); G3: DQ2.5/ X; G4: DQ2.2/X. RESULTS: CD prevalence after 10 years of follow-up was 5.8% (95% confidence interval 3.8-8.7). One of every 3 HLA-DQ2(+) children carried at least 1 haplotype DQ2.2 or DQ7. The homozygous genotype DQ2.5/DQ2.5 and the HLA-DQ2.5 trans genotype increased CD risk 4- and 3-fold, respectively. The homozygous genotype DQ2.5/ DQ2.2 did not increase the CD risk. Children carrying G1 or G2 genotypes were diagnosed with CD earlier and more frequently during the follow-up compare with those carrying G3 or G4 genotypes. Approximately 81% of children with spontaneous antibody negativization after the first screening maintained negative antibodies. CONCLUSIONS: A repeated screening of at-risk children during their follow-up allowed us to diagnose new CD cases. In our cohort, HLA- DQ2.5 trans genotype conferred a higher risk in the development of CD than HLA- DQ2.5/DQ2.2. The majority of children with potential CD and CD autoimmunity at 10 years of age remained healthy.


Subject(s)
Celiac Disease/diagnosis , Genetic Predisposition to Disease/epidemiology , Celiac Disease/epidemiology , Celiac Disease/genetics , Child , Child, Preschool , Female , Follow-Up Studies , Genetic Testing , Genotype , HLA-DQ Antigens/genetics , Haplotypes , Humans , Longitudinal Studies , Male , Prevalence , Prospective Studies , Risk Factors , Spain
9.
Int J Mol Sci ; 20(22)2019 Nov 12.
Article in English | MEDLINE | ID: mdl-31726723

ABSTRACT

Atopic dermatitis (AD) is a predominant and deteriorating chronic inflammation of the skin, categorized by robust burning and eczematous lacerations in diverse portions of the body. AD affects about 20% of both offspring and adults worldwide. The pathophysiology of AD combines environmental, hereditary, and immunological aspects, together with skin barrier dysfunction. The procedures used to prevent the disease are the everyday usage of creams to support the restoration of the epidermal barrier. The classical treatments include the use of topical corticosteroids as a first-line therapy, but also calcineurin inhibitors, antihistamines, antibiotics, phototherapy, and also immunosuppressant drugs in severe cases of AD. Topical drug delivery to deeper skin layers is a difficult task due to the skin anatomic barrier, which limits deeper penetration of drugs. Groundbreaking drug delivery systems, based on nanoparticles (NPs), have received much attention due to their ability to improve solubility, bioavailability, diffusion, targeting to specific types of cells, and limiting the secondary effects of the drugs employed in the treatment of AD. Even so, additional studies are still required to recognize the toxicological characteristics and long-term safety of NPs. This review discusses the current classical pharmacotherapy of AD against new nanoparticle skin delivery systems and their toxicologic risks.


Subject(s)
Anti-Allergic Agents/therapeutic use , Anti-Inflammatory Agents/therapeutic use , Dermatitis, Atopic/drug therapy , Drug Delivery Systems , Immunosuppressive Agents/therapeutic use , Nanoparticles/therapeutic use , Administration, Cutaneous , Dermatitis, Atopic/metabolism , Dermatitis, Atopic/pathology , Drug Delivery Systems/methods , Drug Delivery Systems/trends , Humans
10.
Skin Pharmacol Physiol ; 31(2): 59-73, 2018.
Article in English | MEDLINE | ID: mdl-29262420

ABSTRACT

Neoplastic skin lesions are multifocal, diffuse skin infiltrations of particular relevance in the differential diagnosis of ulcerative, nodular, or crusting skin lesions. Nonmelanoma skin cancers (NMSCs), namely, basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and also actinic keratosis (AK), are the most common malignant tumors in humans. BCCs do not proliferate rapidly and most of the times do not metastasize, while SCCs are more infiltrative, metastatic, and destructive. AKs are precursor lesions of cutaneous SCCs. The classical therapy of NMSCs makes use of photodynamic therapy associated with chemotherapeutics. With improved understanding of the pathological mechanisms of tumor initiation, progression, and differentiation, a case is made towards the use of targeted chemotherapy with the intent to reduce the cytotoxicity of classical treatments. The present review aims to describe the current state of the art on the knowledge of NMSC, including its risks factors, oncogenes, and skin carcinogenesis, discussing the classical therapy against new therapeutic options.


Subject(s)
Skin Diseases/pathology , Skin Neoplasms/pathology , Skin/pathology , Cell Differentiation/physiology , Disease Progression , Humans , Risk Factors
11.
J Pharmacol Exp Ther ; 359(1): 194-206, 2016 10.
Article in English | MEDLINE | ID: mdl-27432892

ABSTRACT

The renal outer medullary potassium (ROMK) channel, located at the apical surface of epithelial cells in the thick ascending loop of Henle and cortical collecting duct, contributes to salt reabsorption and potassium secretion, and represents a target for the development of new mechanism of action diuretics. This idea is supported by the phenotype of antenatal Bartter's syndrome type II associated with loss-of-function mutations in the human ROMK channel, as well as, by cardiovascular studies of heterozygous carriers of channel mutations associated with type II Bartter's syndrome. Although the pharmacology of ROMK channels is still being developed, channel inhibitors have been identified and shown to cause natriuresis and diuresis, in the absence of any significant kaliuresis, on acute oral dosing to rats or dogs. Improvements in potency and selectivity have led to the discovery of MK-7145 [5,5'-((1R,1'R)-piperazine-1,4-diylbis(1-hydroxyethane-2,1-diyl))bis(4-methylisobenzofuran-1(3H)-one)], a potential clinical development candidate. In spontaneously hypertensive rats, oral dosing of MK-7145 causes dose-dependent lowering of blood pressure that is maintained during the entire treatment period, and that displays additive/synergistic effects when administered in combination with hydrochlorothiazide or candesartan, respectively. Acute or chronic oral administration of MK-7145 to normotensive dogs led to dose-dependent diuresis and natriuresis, without any significant urinary potassium losses or changes in plasma electrolyte levels. Elevations in bicarbonate and aldosterone were found after 6 days of dosing. These data indicate that pharmacological inhibition of ROMK has potential as a new mechanism for the treatment of hypertension and/or congestive heart failure. In addition, Bartter's syndrome type II features are manifested on exposure to ROMK inhibitors.


Subject(s)
Bartter Syndrome/physiopathology , Benzofurans/pharmacology , Blood Pressure/drug effects , Phenotype , Piperazines/pharmacology , Potassium Channel Blockers/pharmacology , Potassium Channels, Inwardly Rectifying/antagonists & inhibitors , Animals , Bartter Syndrome/drug therapy , Benzimidazoles/pharmacology , Benzofurans/therapeutic use , Biphenyl Compounds , Dogs , Dose-Response Relationship, Drug , Drug Synergism , Female , HEK293 Cells , Humans , Hydrochlorothiazide/pharmacology , Male , Piperazines/therapeutic use , Potassium Channel Blockers/therapeutic use , Rats , Tetrazoles/pharmacology
12.
Bioorg Med Chem Lett ; 26(9): 2339-43, 2016 May 01.
Article in English | MEDLINE | ID: mdl-27017115

ABSTRACT

Following the discovery of small molecule acyl piperazine ROMK inhibitors and their initial preclinical validation as a novel diuretic agent, our group set out to discover new ROMK inhibitors with reduced risk for QT effects, suitable for further pharmacological experiments in additional species. Several strategies for decreasing hERG affinity while maintaining ROMK inhibition were investigated and are described herein. The most promising candidate, derived from the newly discovered 4-N-heteroaryl acetyl series, improved functional hERG/ROMK ratio by >10× over the previous lead. In vivo evaluation demonstrated comparable diuretic effects in rat with no detectable QT effects at the doses evaluated in an in vivo dog model.


Subject(s)
ERG1 Potassium Channel/physiology , Heterocyclic Compounds/pharmacology , Piperazines/pharmacology , Heterocyclic Compounds/chemistry , Piperazines/chemistry , Structure-Activity Relationship
13.
Bioorg Med Chem Lett ; 26(23): 5695-5702, 2016 12 01.
Article in English | MEDLINE | ID: mdl-27839686

ABSTRACT

Following the discovery of small molecule acyl piperazine ROMK inhibitors, the acyl octahydropyrazino[2,1-c][1,4]oxazine series was identified. This series displays improved ROMK/hERG selectivity, and as a consequence, the resulting ROMK inhibitors do not evoke QTc prolongation in an in vivo cardiovascular dog model. Further efforts in this series led to the discovery of analogs with improved pharmacokinetic profiles. This new series also retained comparable ROMK potency compared to earlier leads.


Subject(s)
Oxazines/chemistry , Oxazines/pharmacology , Potassium Channels, Inwardly Rectifying/antagonists & inhibitors , Animals , Diuresis/drug effects , Dogs , Heart Failure/drug therapy , Humans , Hypertension/drug therapy , Macaca mulatta , Oxazines/pharmacokinetics , Potassium Channels, Inwardly Rectifying/metabolism , Rats, Sprague-Dawley , Transcriptional Regulator ERG/antagonists & inhibitors , Transcriptional Regulator ERG/metabolism
14.
J Magn Reson Imaging ; 41(6): 1622-8, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25168165

ABSTRACT

BACKGROUND: To characterize regional kidney sodium response by MRI following NKCC2 inhibition. METHODS: Regional renal sodium signals were monitored noninvasively using (23) Na-MRI at 9.4T with a temporal resolution of 1.5 min in anesthetized rats (N = 14). A mild NKCC2 inhibition was induced using a slow intravenous furosemide infusion. Time course of sodium signal was modeled as an exponential transient with a single characteristic time constant. RESULTS: Under normal physiological conditions, the renal sodium signals in medullary and cortical regions were stable and found to respond differently to furosemide challenge. Furosemide infusion at 1.2 mg/kg/h (N = 7) increased sodium signal in the cortex by 40 ± 6% (P < 7 × 10(-5) ) whereas decreased in the medulla by 29 ± 2% (P < 3 × 10(-6) ) with different temporal kinetics. The characteristic time constants of the change were determined to be: 8 ± 2 and 70 ± 10 min for medulla and cortex. Also, the medullary change occurred 9(±3) times faster than cortical independent of furosemide infusion rate up to 35 mg/kg/h. CONCLUSION: The pharmacological effects in terms of regional kidney sodium signal changes induced by NKCC2 inhibition are region-specific and highly predictable. Using noninvasive sodium MRI, we obtained regional renal sodium kinetics data sets in response to a low dose furosemide infusion in normal rats.


Subject(s)
Diuretics/pharmacology , Furosemide/pharmacology , Kidney Cortex/drug effects , Kidney Medulla/drug effects , Magnetic Resonance Imaging/methods , Sodium/metabolism , Animals , Male , Rats , Rats, Sprague-Dawley
15.
Nanomedicine ; 11(3): 521-30, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25659643

ABSTRACT

Oleanolic acid (OA) and ursolic acid (UA) are ubiquitous pentacyclic triterpenes compounds in plants with great interest as anti-inflammatory therapeutics. The aim of this study was the design and optimization of polymeric nanoparticles (NPs) loaded with natural and synthetic mixtures (NM, SM) of these drugs for ophthalmic administration. A 2(3) + star central rotatable composite design was employed to perform the experiments. Results showed optimal and stable formulations with suitable physicochemical properties (mean diameter<225 nm), homogeneous distribution (polydispersity index∼0.1), negatively charged surface (∼-27 mV) and high entrapment efficiency (∼77%). Release and corneal permeation studies showed that NM release was faster than SM. Amounts of drug retained in the corneal tissue were also higher for NM. In vitro and in vivo tests showed no signs of irritation or toxicity and successful in vivo anti-inflammatory efficacy for both formulations, being NM-OA/UA NPs the most effective. From the clinical editor: Oleanolic acid (OA) and ursolic acid (UA) are compounds found in plants with anti-inflammatory properties. The authors in this paper designed nanoparticles (NPs) using poly(dl-lactide-coglycolide) acid (PLGA) loaded with these compounds for ophthalmic administration. Both in vitro and in vivo experiments showed no toxicity and significant anti-inflammatory efficacy. This may provide new drugs for ocular anti-inflammatory treatment.


Subject(s)
Anti-Inflammatory Agents , Drug Delivery Systems/methods , Drug Design , Eye Diseases , Nanoparticles/chemistry , Oleanolic Acid , Triterpenes , Animals , Anti-Inflammatory Agents/chemistry , Anti-Inflammatory Agents/pharmacokinetics , Anti-Inflammatory Agents/pharmacology , Drug Evaluation, Preclinical , Eye Diseases/drug therapy , Oleanolic Acid/chemistry , Oleanolic Acid/pharmacokinetics , Oleanolic Acid/pharmacology , Rabbits , Triterpenes/chemistry , Triterpenes/pharmacokinetics , Triterpenes/pharmacology , Ursolic Acid
16.
J Pharmacol Exp Ther ; 348(1): 153-64, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24142912

ABSTRACT

The renal outer medullary potassium (ROMK) channel, which is located at the apical membrane of epithelial cells lining the thick ascending loop of Henle and cortical collecting duct, plays an important role in kidney physiology by regulating salt reabsorption. Loss-of-function mutations in the human ROMK channel are associated with antenatal type II Bartter's syndrome, an autosomal recessive life-threatening salt-wasting disorder with mild hypokalemia. Similar observations have been reported from studies with ROMK knockout mice and rats. It is noteworthy that heterozygous carriers of Kir1.1 mutations associated with antenatal Bartter's syndrome have reduced blood pressure and a decreased risk of developing hypertension by age 60. Although selective ROMK inhibitors would be expected to represent a new class of diuretics, this hypothesis has not been pharmacologically tested. Compound A [5-(2-(4-(2-(4-(1H-tetrazol-1-yl)phenyl)acetyl)piperazin-1-yl)ethyl)isobenzofuran-1(3H)-one)], a potent ROMK inhibitor with appropriate selectivity and characteristics for in vivo testing, has been identified. Compound A accesses the channel through the cytoplasmic side and binds to residues lining the pore within the transmembrane region below the selectivity filter. In normotensive rats and dogs, short-term oral administration of compound A caused concentration-dependent diuresis and natriuresis that were comparable to hydrochlorothiazide. Unlike hydrochlorothiazide, however, compound A did not cause any significant urinary potassium losses or changes in plasma electrolyte levels. These data indicate that pharmacologic inhibition of ROMK has the potential for affording diuretic/natriuretic efficacy similar to that of clinically used diuretics but without the dose-limiting hypokalemia associated with the use of loop and thiazide-like diuretics.


Subject(s)
Diuresis/drug effects , Diuresis/physiology , Natriuresis/drug effects , Potassium Channel Blockers/pharmacology , Potassium Channels, Inwardly Rectifying/antagonists & inhibitors , Potassium Channels, Inwardly Rectifying/physiology , Animals , CHO Cells , Cricetinae , Cricetulus , Dogs , Dose-Response Relationship, Drug , Female , HEK293 Cells , Humans , Madin Darby Canine Kidney Cells , Male , Natriuresis/physiology , Rats , Rats, Sprague-Dawley
18.
Microbiol Spectr ; 12(7): e0351323, 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38785434

ABSTRACT

Sweet orange (Citrus sinensis) is one of the most important fruit crops worldwide. Virus infections in this crop can interfere with cellular processes, causing dramatic economic losses. By performing RT-qPCR analyses, we demonstrated that citrus psorosis virus (CPsV)-infected orange plants exhibited higher levels of unprocessed microRNA (miRNA) precursors than healthy plants. This result correlated with the reported reduction of mature miRNAs species. The protein 24K, the CPsV suppressor of RNA silencing (VSR), interacts with miRNA precursors in vivo. Thus, this protein becomes a candidate responsible for the increased accumulation of unprocessed miRNAs. We analyzed 24K RNA-binding and protein-protein interaction domains and described patterns of its subcellular localization. We also showed that 24K colocalizes within nuclear D-bodies with the miRNA biogenesis proteins DICER-LIKE 1 (DCL1), HYPONASTIC LEAVES 1 (HYL1), and SERRATE (SE). According to the results of bimolecular fluorescence complementation and co-immunoprecipitation assays, the 24K protein interacts with HYL1 and SE. Thus, 24K may inhibit miRNA processing in CPsV-infected citrus plants by direct interaction with the miRNA processing complex. This work contributes to the understanding of how a virus can alter the regulatory mechanisms of the host, particularly miRNA biogenesis and function.IMPORTANCESweet oranges can suffer from disease symptoms induced by virus infections, thus resulting in drastic economic losses. In sweet orange plants, CPsV alters the accumulation of some precursors from the regulatory molecules called miRNAs. This alteration leads to a decreased level of mature miRNA species. This misregulation may be due to a direct association of one of the viral proteins (24K) with miRNA precursors. On the other hand, 24K may act with components of the cell miRNA processing machinery through a series of predicted RNA-binding and protein-protein interaction domains.


Subject(s)
Citrus sinensis , MicroRNAs , Plant Diseases , Viral Proteins , MicroRNAs/metabolism , MicroRNAs/genetics , Plant Diseases/virology , Viral Proteins/metabolism , Viral Proteins/genetics , Citrus sinensis/virology , Citrus sinensis/metabolism , Plant Viruses/genetics , Plant Viruses/metabolism , Plant Viruses/physiology , Plant Proteins/metabolism , Plant Proteins/genetics , RNA-Binding Proteins/metabolism , RNA-Binding Proteins/genetics , RNA Processing, Post-Transcriptional , Citrus/virology , Citrus/metabolism , RNA Precursors/metabolism , RNA Precursors/genetics
19.
J Pharmacol Exp Ther ; 344(2): 407-16, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23161216

ABSTRACT

The voltage-gated potassium channels Kv2.1 and Kv2.2 are highly expressed in pancreatic islets, yet their contribution to islet hormone secretion is not fully understood. Here we investigate the role of Kv2 channels in pancreatic islets using a combination of genetic and pharmacologic approaches. Pancreatic ß-cells from Kv2.1(-/-) mice possess reduced Kv current and display greater glucose-stimulated insulin secretion (GSIS) relative to WT ß-cells. Inhibition of Kv2.x channels with selective peptidyl [guangxitoxin-1E (GxTX-1E)] or small molecule (RY796) inhibitors enhances GSIS in isolated wild-type (WT) mouse and human islets, but not in islets from Kv2.1(-/-) mice. However, in WT mice neither inhibitor improved glucose tolerance in vivo. GxTX-1E and RY796 enhanced somatostatin release in isolated human and mouse islets and in situ perfused pancreata from WT and Kv2.1(-/-) mice. Kv2.2 silencing in mouse islets by adenovirus-small hairpin RNA (shRNA) specifically enhanced islet somatostatin, but not insulin, secretion. In mice lacking somatostatin receptor 5, GxTX-1E stimulated insulin secretion and improved glucose tolerance. Collectively, these data show that Kv2.1 regulates insulin secretion in ß-cells and Kv2.2 modulates somatostatin release in δ-cells. Development of selective Kv2.1 inhibitors without cross inhibition of Kv2.2 may provide new avenues to promote GSIS for the treatment of type 2 diabetes.


Subject(s)
Insulin-Secreting Cells/metabolism , Insulin/metabolism , Shab Potassium Channels/metabolism , Somatostatin/metabolism , Adult , Animals , Arthropod Proteins , Benzamides/pharmacology , Cells, Cultured , Electrophysiological Phenomena , Female , Glucose/pharmacology , Humans , Insulin Secretion , Insulin-Secreting Cells/drug effects , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Middle Aged , Patch-Clamp Techniques , Peptides/pharmacology , Potassium Channel Blockers/pharmacology , Protein Binding , Receptors, Somatostatin/genetics , Receptors, Somatostatin/metabolism , Shab Potassium Channels/antagonists & inhibitors , Shab Potassium Channels/genetics , Spider Venoms/pharmacology , Young Adult
20.
Bioorg Med Chem Lett ; 23(12): 3640-5, 2013 Jun 15.
Article in English | MEDLINE | ID: mdl-23652221

ABSTRACT

A series of benzazepinones were synthesized and evaluated for block of Nav1.7 sodium channels. Compound 30 from this series displayed potent channel block, good selectivity versus other targets, and dose-dependent oral efficacy in a rat model of neuropathic pain.


Subject(s)
Benzazepines/pharmacology , Neuralgia/drug therapy , Sodium Channel Blockers/pharmacology , Animals , Disease Models, Animal , Rats
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