RESUMEN

BACKGROUND: Chronic pain management remains a challenging aspect of neurosurgical care, with facet arthrosis being a significant contributor to the global burden of low back pain. This study evaluates the effectiveness of cryotherapy as a minimally invasive treatment for patients with facet arthrosis. By focusing on reducing drug dependency and pain intensity, the research aims to contribute to the evolving field of pain management techniques, offering an alternative to traditional pain management strategies. METHODS: Through a retrospective longitudinal analysis of patients with facet osteoarthritis treated via cryotherapy between 2013 and 2023, we evaluated the impact on medication usage and pain levels, utilizing the Visual Analog Scale for pre- and posttreatment comparisons. RESULTS: The study encompassed 118 subjects, revealing significant pain alleviation, with Visual Analog Scale scores plummeting from 9.0 initially to 2.0 after treatment. Additionally, 67 patients (56.78%) reported decreased medication consumption. These outcomes underscore cryotherapy's potential as a pivotal tool in chronic pain management. CONCLUSIONS: The findings illuminate cryotherapy's efficacy in diminishing pain and curtailing medication dependency among patients with facet arthrosis. This study reaffirms cryotherapy's role in pain management and propels the discourse on nontraditional therapeutic avenues, highlighting the urgent need for personalized and innovative treatment frameworks.

Asunto(s)

RESUMEN

OBJECTIVE: In asthma, genome-wide association studies have shown that interleukin-18 (IL-18) receptor 1 gene (IL-18R1) and sputum IL-18 are increased during exacerbations. However, the role of the IL-18 axis in bronchial epithelial function is unclear. To investigate IL-18, IL-18 binding protein (BP) and IL-18R expression in bronchial biopsies and sputum samples from patients with asthma, and to determine its functional role using in vitro bronchial epithelial cells. METHODS: The expression of IL-18, IL-18BP and IL-18Rα was examined in subjects with asthma and healthy controls in bronchial biopsies by immunohistochemistry and IL-18 and IL-18BP release in sputum. In epithelial cells, the mRNA and protein expression of IL-18, IL-18BP, IL-18Rα and IL-18Rß was assessed by qPCR, flow cytometry, Western blotting and immunofluorescence respectively. IL-18 function in epithelial cells was examined by intracellular calcium, wound repair, synthetic activation and epithelial differentiation changes. RESULTS: In biopsies from subjects with asthma, the IL-18 expression was not different in the lamina propria compared with controls but was decreased in the epithelium. In contrast, the IL-18BP was decreased in the lamina propria in asthma and was absent in the bronchial epithelium. IL-18 was released in sputum with IL-18BP elevated in patients with asthma. The IL-18Rα expression was not different between health and disease. In vitro, IL-18-stimulated bronchial epithelial cells increased intracellular calcium, wound repair, metabolic activity, morphological changes and epithelial cellular differentiation. CONCLUSION: In asthma, the dynamic interaction between IL-18, its cognate receptor and natural inhibitor is complex, with differences between airway compartments. Upregulation of IL-18 can promote epithelial activation and cellular differentiation.

RESUMEN

BACKGROUND: The airway epithelium plays an important role in wound repair, host defense and is involved in the immunopathogenesis of asthma. Genome wide association studies have described associations between ST2/Interleukin (IL)-33 genes in asthma, but its role in bronchial epithelium is unclear. METHODS: ST2 expression was examined in subjects with asthma and healthy controls in bronchial epithelium from biopsies (n = 27 versus n = 9) and brushings (n = 34 versus n = 20) by immunohistochemistry and RNA-Seq. In human primary bronchial epithelial cells ST2 mRNA and protein expression were assessed by qPCR, flow cytometry, Western blotting, and immunofluorescence. IL-33 function in epithelial cells was examined by intracellular calcium measurements, wound healing assays, and synthetic activation by gene array and ELISA. RESULTS: Bronchial epithelial ST2 protein expression was significantly decreased in biopsies in subjects with asthma compared to healthy controls (P = .039). IL1RL1 gene expression in bronchial brushes was not different between health and disease. In vitro primary bronchial epithelial cells expressed ST2 and IL-33 stimulation led to an increase in intracellular calcium, altered gene expression, but had no effect upon wound repair. Epithelial cells released sST2 spontaneously, which was reduced following stimulation with TNFα or poly-IC. Stimulation by TNFα or poly-IC did not affect the total ST2 expression by epithelial cell whereas surface ST2 decreased in response to TNFα, but not poly-IC. CONCLUSION: In asthma, bronchial epithelium protein expression of ST2 is decreased. Our in vitro findings suggest that this decrease might be a consequence of the pro-inflammatory environment in asthma or in response to viral infection.

Asunto(s)

Asunto(s)

RESUMEN

The burden of oxidative stress is increased in chronic obstructive pulmonary disease (COPD). However, whether the intra-cellular mechanisms controlling the oxidant/anti-oxidant balance in structural airway cells such as airway smooth muscle in COPD is altered is unclear. We sought to determine whether the expression of the NADPH oxidase (NOX)-4 is increased in airway smooth muscle in COPD both in vivo and primary cells in vitro and its role in hydrogen peroxide-induced reactive oxygen species generation. We found that in vivo NOX4 expression was up-regulated in the airway smooth muscle bundle in COPD (n = 9) and healthy controls with >20 pack year history (n = 4) compared to control subjects without a significant smoking history (n = 6). In vitro NOX4 expression was increased in airway smooth muscle cells from subjects with COPD (n = 5) compared to asthma (n = 7) and upregulated following TNF-α stimulation. Hydrogen peroxide-induced reactive oxygen species generation by airway smooth muscle cells in COPD (n = 5) was comparable to healthy controls (n = 9) but lower than asthma (n = 5); and was markedly attenuated by NOX4 inhibition. Our findings demonstrate that NOX4 expression is increased in vivo and in vitro in COPD and although we did not observe an intrinsic increase in oxidant-induced reactive oxygen species generation in COPD, it was reduced markedly by NOX4 inhibition supporting a potential therapeutic role for NOX4 in COPD.

Asunto(s)

RESUMEN

BACKGROUND: Bronchial epithelial ciliary dysfunction is an important feature of asthma. We sought to determine the role in asthma of neutrophilic inflammation and nicotinamide adenine dinucleotide phosphate (NADPH) oxidases in ciliary dysfunction. METHODS: Bronchial epithelial ciliary function was assessed by using video microscopy in fresh ex vivo epithelial strips from patients with asthma stratified according to their sputum cell differentials and in culture specimens from healthy control subjects and patients with asthma. Bronchial epithelial oxidative damage was determined by 8-oxo-dG expression. Nicotinamide adenine dinucleotide phosphate oxidase (NOX)/dual oxidase (DUOX) expression was assessed in bronchial epithelial cells by using microarrays, with NOX4 and DUOX1/2 expression assessed in bronchial biopsy specimens. Ciliary dysfunction following NADPH oxidase inhibition, using GKT137831, was evaluated in fresh epithelial strips from patients with asthma and a murine model of ovalbumin sensitization and challenge. RESULTS: Ciliary beat frequency was impaired in patients with asthma with sputum neutrophilia (n = 11) vs those without (n = 10) (5.8 [0.6] Hz vs 8.8 [0.5] Hz; P = .003) and was correlated with sputum neutrophil count (r = -0.70; P < .001). Primary bronchial epithelial cells expressed DUOX1/2 and NOX4. Levels of 8-oxo-dG and NOX4 were elevated in patients with neutrophilic vs nonneutrophilic asthma, DUOX1 was elevated in both, and DUOX2 was elevated in nonneutrophilic asthma in vivo. In primary epithelial cultures, ciliary dysfunction did not persist, although NOX4 expression and reactive oxygen species generation was increased from patients with neutrophilic asthma. GKT137831 both improved ciliary function in ex vivo epithelial strips (n = 13), relative to the intensity of neutrophilic inflammation, and abolished ciliary dysfunction in the murine asthma model with no reduction in inflammation. CONCLUSIONS: Ciliary dysfunction is increased in neutrophilic asthma associated with increased NOX4 expression and is attenuated by NADPH oxidase inhibition.

Asunto(s)

RESUMEN

BACKGROUND: Asthma is characterized by airway hyper-responsiveness and variable airflow obstruction, in part as a consequence of hyper-contractile airway smooth muscle, which persists in primary cell culture. One potential mechanism for this hyper-contractility is abnormal intracellular Ca(2+) handling. METHODS: We sought to compare intracellular Ca(2+) handling in airway smooth muscle cells from subjects with asthma compared to non-asthmatic controls by measuring: i) bradykinin-stimulated changes in inositol 1,4,5-trisphosphate (IP3) accumulation and intracellular Ca(2+) concentration, ii) sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA) expression, iii) mechanisms of cytoplasmic Ca(2+) clearance assessed following instantaneous flash photolytic release of Ca(2+) into the cytoplasm. RESULTS: We found no differences in airway smooth muscle cell basal intracellular Ca(2+) concentrations, bradykinin-stimulated IP3 accumulation or intracellular Ca(2+) responses. Quantification of SERCA2 mRNA or protein expression levels revealed no differences in ASM cells obtained from subjects with asthma compared to non-asthmatic controls. We did not identify differences in intracellular calcium kinetics assessed by flash photolysis and calcium uncaging independent of agonist-activation with or without SERCA inhibition. However, we did observe some correlations in subjects with asthma between lung function and the different cellular measurements of intracellular Ca(2+) handling, with poorer lung function related to increased rate of recovery following flash photolytic elevation of cytoplasmic Ca(2+) concentration. CONCLUSIONS: Taken together, the experimental results reported in this study do not demonstrate major fundamental differences in Ca(2+) handling between airway smooth muscle cells from non-asthmatic and asthmatic subjects. Therefore, increased contraction of airway smooth muscle cells derived from asthmatic subjects cannot be fully explained by altered Ca(2+) homeostasis.

Asunto(s)

RESUMEN

The cause of airway smooth muscle (ASM) hypercontractility in asthma is not fully understood. The relationship of spontaneous intracellular calcium oscillation frequency in ASM to asthma severity was investigated. Oscillations were increased in subjects with impaired lung function abolished by extracellular calcium removal, attenuated by caffeine and unaffected by verapamil or nitrendipine. Whether modulation of increased spontaneous intracellular calcium oscillations in ASM from patients with impaired lung function represents a therapeutic target warrants further investigation.

Asunto(s)

RESUMEN

RATIONALE: Asthma is characterized by disordered airway physiology as a consequence of increased airway smooth muscle contractility. The underlying cause of this hypercontractility is poorly understood. OBJECTIVES: We sought to investigate whether the burden of oxidative stress in airway smooth muscle in asthma is heightened and mediated by an intrinsic abnormality promoting hypercontractility. METHODS: We examined the oxidative stress burden of airway smooth muscle in bronchial biopsies and primary cells from subjects with asthma and healthy controls. We determined the expression of targets implicated in the control of oxidative stress in airway smooth muscle and their role in contractility. MEASUREMENTS AND MAIN RESULTS: We found that the oxidative stress burden in the airway smooth muscle in individuals with asthma is heightened and related to the degree of airflow obstruction and airway hyperresponsiveness. This was independent of the asthmatic environment as in vitro primary airway smooth muscle from individuals with asthma compared with healthy controls demonstrated increased oxidative stress-induced DNA damage together with an increased production of reactive oxygen species. Genome-wide microarray of primary airway smooth muscle identified increased messenger RNA expression in asthma of NADPH oxidase (NOX) subtype 4. This NOX4 overexpression in asthma was supported by quantitative polymerase chain reaction, confirmed at the protein level. Airway smooth muscle from individuals with asthma exhibited increased agonist-induced contraction. This was abrogated by NOX4 small interfering RNA knockdown and the pharmacological inhibitors diphenyleneiodonium and apocynin. CONCLUSIONS: Our findings support a critical role for NOX4 overexpression in asthma in the promotion of oxidative stress and consequent airway smooth muscle hypercontractility. This implicates NOX4 as a potential novel target for asthma therapy.

Asunto(s)

RESUMEN

Protein kinase R-like ER kinase (PERK) is activated at physiologically low glucose concentrations in pancreatic ß-cells. However, the molecular mechanisms by which PERK is activated under these conditions and its role in ß-cell function are poorly understood. In this report, we investigated, in dispersed rat islets of Langerhans and mouse insulinoma-6 (MIN6) cells, the relationship between extracellular glucose concentration, the free endoplasmic reticulum (ER) calcium concentration ([Ca(2+)](ER)) measured directly using an ER targeted fluorescence resonance energy transfer-based calcium sensor, and the activation of PERK. We found that a decrease in glucose concentration leads to a concentration-dependent reduction in [Ca(2+)](ER) that parallels the activation of PERK and the phosphorylation of its substrate eukaryotic initiation factor-2α. We provide evidence that this decrease in [Ca(2+)](ER) is caused by a decrease in sarcoplasmic/ER Ca(2+)-ATPase pump activity mediated by a reduction in the energy status of the cell. Importantly, we also report that PERK-dependent eukaryotic initiation factor-2α phosphorylation at low glucose concentration plays a significant role in 1) the regulation of both proinsulin and global protein synthesis, 2) cell viability, and 3) conferring preemptive cytoprotection against ER stress. Taken together, these results provide evidence that a decrease in the ATP/energy status of the cell in response to a decrease in glucose concentration results in sarcoplasmic/ER Ca(2+)-ATPase pump inhibition, the efflux of Ca(2+) from the ER, and the activation of PERK, which plays an important role in both pancreatic ß-cell function and survival.

Asunto(s)

RESUMEN

Ribosomal protein S6 (rpS6) is phosphorylated in vivo by isoforms of p70 S6 protein kinase and p90 ribosomal S6 kinase, and there is good evidence that it plays a positive role in controlling pancreatic beta-cell size and function. In this report, we demonstrate in the pancreatic beta-cell line MIN6 (mouse insulinoma cell line 6) and islets of Langerhans that agents which stimulate increases in cAMP, such as glucagon-like peptide-1 and forskolin, lead to the phosphorylation of rpS6 at Ser235/Ser236 independently of the activation of the currently known in vivo rpS6 kinases via a pathway that is sensitive to inhibitors of cAMP-dependent protein kinase [protein kinase A (PKA)]. This cAMP-dependent rpS6 kinase activity is also sensitive to PKI in vitro, and PKA exclusively phosphorylates recombinant rpS6 on Ser235/Ser236 in vitro. With these data taken together, we conclude that PKA can phosphorylate rpS6 exclusively at Ser235/Ser236 in vivo in pancreatic beta-cells, thus providing a potentially important link between cAMP signalling and the regulation of protein synthesis. Lastly, we provide evidence that PKA is also likely to phosphorylate rpS6 on Ser235/Ser236 in vivo in a number of other mammalian cell types.

Asunto(s)

RESUMEN

In the present study, we demonstrate that, in pancreatic beta-cells, eIF2alpha (eukaryotic initiation factor 2alpha) phosphorylation in response to a decrease in glucose concentration is primarily mediated by the activation of PERK [PKR (protein kinase RNA activated)-like endoplasmic reticulum kinase]. We provide evidence that this increase in PERK activity is evoked by a decrease in the energy status of the cell via a potentially novel mechanism that is independent of IRE1 (inositol requiring enzyme 1) activation and the accumulation of unfolded nascent proteins within the endoplasmic reticulum. The inhibition of eIF2alpha phosphorylation in glucose-deprived cells by the overexpression of dominant-negative PERK or an N-terminal truncation mutant of GADD34 (growth-arrest and DNA-damage-inducible protein 34) leads to a 53% increase in the rate of total protein synthesis. Polysome analysis revealed that this coincides with an increase in the amplitude but not the number of ribosomes per mRNA, indicating that eIF2alpha dephosphorylation mobilizes hitherto untranslated mRNAs on to polysomes. In summary, we show that PERK is activated at low glucose concentrations in response to a decrease in energy status and that this plays an important role in glucose-regulated protein synthesis in pancreatic beta-cells.

Asunto(s)

RESUMEN

The eukaryotic initiation factor 2B (eIF2B) is a five-subunit guanine nucleotide exchange factor, that functions during translation initiation to catalyze the otherwise slow exchange of GDP for GTP on its substrate eIF2. Assays to measure substrate interaction and guanine nucleotide release ability of eIF2B require the complex to be purified free of interacting proteins. We have also found that a subcomplex of two subunits, gamma and epsilon or the largest one, epsilon alone, promotes this activity. Within eIF2Bepsilon, the catalytic center requires the C-terminal 200 residues only. Here, we describe our protocols for purifying the Saccharomyces cerevisiae eIF2B complexes and the catalytic subunit using FLAG-tagged proteins overexpressed in yeast cells. Using commercially available FLAG-affinity resin and high salt buffer, we are able to purify active eIF2B virtually free of contaminants.

Asunto(s)

RESUMEN

In pancreatic beta-cells, following an acute (within 1 h) increase in glucose concentration, there are rapid changes in the expression of a large subset of proteins. The change in the expression of many of these proteins is mediated by a post-transcriptional mechanism through either increases or decreases in the rate of translation from pre-existing transcripts. These proteins, whose synthesis is rapidly up- or down-regulated in response to glucose, are likely important in mounting the correct response to changes in plasma glucose concentrations. However, the vast majority of these proteins remain unidentified. Therefore, in order to identify these proteins, we analysed changes in the levels of mRNAs associated with polysomes (i.e. actively translating mRNAs) isolated from mouse insulinoma 6 cells incubated at either 0.5 or 20 mM glucose for 1 h. Changes in the levels of polysomal mRNAs in response to glucose were analysed using affymetrix oligonucleotide microarrays (translational profiling). This work revealed that, in response to a change in glucose concentration, the abundance of 313 transcripts associated with polysomes changed by more than 1.5-fold, of which the abundance of 37 changed by more than twofold. The majority of these transcripts encoded proteins associated with metabolism or gene expression. More detailed analysis showed that a number of mRNAs encoding proteins associated with the induction of oxidative stress, including thioredoxin-2 and thioredoxin-interacting protein were rapidly redistributed onto heavier polysomes at high glucose concentration, indicating an increase in their expression. At low glucose concentration, when the general rate of protein synthesis is low, a number of mRNAs encoding integrated stress response proteins, including ATF4 and CHOP10, associate with heavier polysomes, indicating that their expression is up-regulated. In conclusion, translational profiling has revealed that, at either low or at high glucose concentration, beta-cells rapidly increase the synthesis of a specific subset of proteins that are likely important in maintaining beta-cell integrity and survival during conditions of nutritional stress.

Asunto(s)

RESUMEN

Glucose acutely stimulates proinsulin synthesis in pancreatic beta-cells through a poorly understood post-transcriptional mechanism. In the present study, we demonstrate in pancreatic beta-cells that glucose stimulates the recruitment of ribosome-associated proinsulin mRNA, located in the cytoplasm, to the ER (endoplasmic reticulum), the site of proinsulin synthesis, and that this plays an important role in glucose-stimulated proinsulin synthesis. Interestingly, glucose has greater stimulatory effect on the recruitment of proinsulin mRNA to the ER compared with other mRNAs encoding secretory proteins. This, as far as we are aware, is the first example whereby mRNAs encoding secretory proteins are selectively recruited to the ER and provides a novel regulatory mechanism for secretory protein synthesis. Contrary to previous reports, and importantly in understanding the mechanism by which glucose stimulates proinsulin synthesis, we demonstrate that there is no large pool of 'free' proinsulin mRNA in the cytoplasm and that glucose does not increase the rate of de novo initiation on the proinsulin mRNA. However, we show that glucose does stimulate the rate of ribosome recruitment on to ribosome-associated proinsulin mRNA. In conclusion, our results provide evidence that the selective recruitment of proinsulin mRNA to the ER, together with increases in the rate of initiation are important mediators of glucose-stimulated proinsulin synthesis in pancreatic beta-cells.

Asunto(s)

RESUMEN

In pancreatic beta-cells, glucose causes a rapid increase in the rate of protein synthesis. However, the mechanism by which this occurs is poorly understood. In this report, we demonstrate, in the pancreatic beta-cell line MIN6, that glucose stimulates the recruitment of ribosomes onto the mRNA, indicative of an increase in the rate of the initiation step of protein synthesis. This increase in the rate of initiation is not mediated through an increase in the availability of the initiation complex eIF4F, because glucose is unable to stimulate eIF4F assembly or, in the absence of amino acids, modulate the phosphorylation status of 4E-BP1. Moreover, in MIN6 cells and isolated islets of Langerhans, rapamycin, an inhibitor of the mammalian target of rapamycin, only partially inhibited glucose-stimulated protein synthesis. However, we show that glucose stimulates the dephosphorylation of eIF2 alpha in MIN6 cells and the assembly of the translational ternary complex, eIF2-GTP.Met-tRNAi, in both MIN6 cells and islets of Langerhans. The changes in the phosphorylation of eIF2 alpha are not mediated by the PKR-like endoplasmic reticulum eIF2 alpha kinase (PERK), because PERK is not phosphorylated at low glucose concentrations and overexpression of a dominant negative form of PERK has no significant effect on either glucose-stimulated protein synthesis or the phosphorylation of eIF2 alpha. Taken together, these results indicate that glucose-stimulated protein synthesis in pancreatic beta-cells is regulated by a mechanism largely independent of the activity of mammalian target of rapamycin, but which is likely to be dependent on the availability of the translational ternary complex, regulated by the phosphorylation status of eIF2 alpha.

Asunto(s)

RESUMEN

Glucagon like peptide-1 (GLP1) is a G(s)-coupled receptor agonist that exerts multiple effects on pancreatic beta-cells, including the stimulation of insulin gene expression and secretion. In this report, we show that treatment of the mouse pancreatic beta-cell line MIN6 with GLP1 leads to the glucose-dependent activation of Erk. These effects are mimicked by forskolin, a direct activator of adenylate cyclase, and blocked by H89, an inhibitor of cAMP-dependent protein kinase. Additionally, we provide evidence that GLP1-stimulated activation of Erk requires an influx of calcium through L-type voltage-gated calcium channels and the activation of calcium/calmodulin-dependent protein kinase II. GLP1-stimulated activation of Erk is blocked by inhibitors of MEK, but GLP1 does not induce the activation of A-Raf, B-Raf, C-Raf, or Ras. Additionally, dominant negative forms of Ras(N17) and Rap1(N17) fail to block GLP1-stimulated activation of Erk. In conclusion, our results indicate that, in the presence of stimulatory concentrations of glucose, GLP1 stimulates the activation of Erk through a mechanism dependent on MEK but independent of both Raf and Ras. This requires 1) the activation of cAMP-dependent protein kinase, 2) an influx of extracellular Ca(2+) through L-type voltage-gated calcium channels, and 3) the activation of CaM kinase II.

Asunto(s)

RESUMEN

For protein synthesis initiation in eukaryotes, eIF2B is the guanine-nucleotide exchange factor for eIF2. eIF2B is an essential multi-subunit factor and a major target for translational control in both yeast and mammalian cells. It was shown previously that the largest eIF2B subunit, eIF2Bepsilon, is the only single subunit with catalytic function. Here we report the results of a molecular dissection of the yeast epsilon subunit encoded by GCD6 in which we have identified the catalytic domain. By analysis of a series of N-terminal deletions in vitro we find that the smallest catalytically active fragment contains residues 518-712 (termed Gcd6p(518-712)). Further deletion to position 581 (Gcd6p(581-712)) results in loss of nucleotide exchange function, but eIF2-binding activity is retained. C- terminal deletion of only 61 residues (Gcd6p(1-651)) results in loss of both functions. Thus Gcd6p(518-712) contains two regions that together constitute the catalytic domain of eIF2B. Finally, we show that the catalytic domain can provide eIF2B biological function in vivo when elevated levels eIF2 and tRNA(i)(Met) are also present.

Asunto(s)

Asunto(s)

RESUMEN

El síndrome de maltrato infantil es una enfermedad adquirida, que predispone al niño a acarrear graves secuelas en las posteriores etapas de la vida, si éste no es tratado y recuperado en el momento oportuno. Afecta no solo al niño, sino al grupo familiar en su totalidad. La enfermera debe ser capaz de detectar los signos y síntomas de dicho síndrome con el fin de participar activamente dentro del equipo de salud y prestar al niño la atención pertinente. El trabajo incluye un enfoque teórico, basado en la experiencia como profesionales de la salud, destacando la intervención de enfermería en el proyecto de creación de un Servicio de Ayuda al Niño Maltratado

Asunto(s)