The aryl hydrocarbon receptor (AhR) is involved in the regulation of immune responses, T-cell differentiation, and immunity. Here, we show that inflammatory stimuli such as LPS induce the expression ...of AhR in human dendritic cells (DC) associated with an AhR-dependent increase of CYP1A1 (cytochrome P4501A1). In vivo data confirmed the elevated expression of AhR by LPS and the LPS-enhanced 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-mediated induction of CYP1A1 in thymus of B6 mice. Inhibition of nuclear factor-κB (NF-κB) repressed both normal and LPS-enhanced, TCDD-inducible, AhR-dependent gene expression and canonical pathway control of RelA-regulated AhR-responsive gene expression. LPS-mediated induction of AhR was NF-κB-dependent, as shown in mouse embryonic fibroblasts (MEFs) derived from Rel null mice. AhR expression and TCDD-mediated induction of CYP1A1 was significantly reduced in RelA-deficient MEF compared with wild type MEF cells and ectopic expression of RelA restored the expression of AhR and induction of CYP1A1 in MEF RelA null cells. Promoter analysis of the human AhR gene identified three putative NF-κB-binding elements upstream of the transcription start site. Mutation analysis of the AhR promoter identified one NF-κB site as responsible for mediating the induction of AhR expression by LPS and electrophoretic shift assays demonstrated that this NF-κB motif is recognized by the RelA/p50 heterodimer. Our results show for the first time that NF-κB RelA is a critical component regulating the expression of AhR and the induction of AhR-dependent gene expression in immune cells illustrating the interaction of AhR and NF-κB signaling.
Crystallographic studies have offered understanding of how receptor tyrosine kinases from the ErbB family are regulated by their growth factor ligands. A conformational change of the EGFR (ErbB1) was ...shown to occur upon ligand binding, where a solely ligand-mediated mode of dimerization/activation was documented. However, this dogma of dimerization/activation was revolutionized by the discovery of constitutively active ligand-independent EGFR mutants. In addition, other ligand-independent activation mechanisms may occur. We have shown that oxidative stress (ox-stress), induced by hydrogen peroxide or cigarette smoke, activates EGFR differently than its ligand, EGF, thereby inducing aberrant phosphorylation and impaired trafficking and degradation of EGFR. Here we demonstrate that ox-stress activation of EGFR is ligand-independent, does not induce "classical" receptor dimerization and is not inhibited by the tyrosine kinase inhibitor AG1478. Thus, an unprecedented, apparently activated, state is found for EGFR under ox-stress. Furthermore, this activation mechanism is temperature-dependent, suggesting the simultaneous involvement of membrane structure. We propose that ceramide increase under ox-stress disrupts cholesterol-enriched rafts leading to EGFR re-localization into the rigid, ceramide-enriched rafts. This increase in ceramide also supports EGFR aberrant trafficking to a peri-nuclear region. Therefore, the EGFR unprecedented and activated conformation could be sustained by simultaneous alterations in membrane structure under ox-stress.
Objective: To identify factors causing diagnostic and therapeutic delay in patients with rheumatoid arthritis, and to evaluate relationship of diagnostic and therapeutic delay with disease outcome.
...Methods: This cross-sectional study was conducted in Rheumatology Department, Fatima Memorial Hospital, Lahore, Pakistan, from May 2018 to July 2018. In this study 102 patients fulfilling ACR/EULAR criteria 2010 were enrolled. Lag times were calculated in months: lag-1 (delay in initial medical consultation); lag-2 (delay in consulting rheumatologists); lag-3 (diagnostic delay); lag-4 (therapeutic delay). Disease activity and functional outcome were measured by DAS28, HAQ-DI respectively. Association of lag-3 and lag-4 with HAQ-DI and DAS28 was calculated by Pearson correlation.
Results: Median (IQR) disease duration of study group was 6(2-10) years. Initial consultations were with; orthopedic surgeon 40(39.2%), general practitioner 27(26.5%), rheumatologist 13(12.7%), medical specialists 14(13.7%). Median (IQR) lag times in months: lag-1 (delayed initial consultation): 2(0-5), lag-2 (delay in consulting rheumatologist): 30(7.7-72), lag-3 (diagnostic delay): 12(3-48), lag-4 (therapeutic delay):18(5.7-72). Factors attributed to lag-3 (diagnostic delay) and lag-4 (therapeutic delay) (p<0.05): older Age (r= 0.2), education level (r= - 0.2), initial consultation (non-rheumatologist) (r=0.2), lag-2(r=0.8), >three doctors visited before diagnosis(r=0.6). Positive anti-CCP antibodies(r=0.2) and lag-1 (delayed initial consultation) (r=1) were associated with lag-3 (diagnostic delay) only; no association was found with positive RA factor. Significant correlation (p=<0.05) of lag-3 (diagnostic delay) was found with both DAS28(r=0.2) & HAQ-DI(r=0.2). Similarly lag-4 (therapeutic delay) also correlated with both & DAS28(r=0.2) & HAQ-DI(r=0.3) (p=<0.05).
Conclusion: Diagnostic and therapeutic delay were associated with older age, lower education and delayed consultation with rheumatologist but not with positive RA factor. Positive anti-CCP antibodies were associated with diagnostic delay only. Diagnostic and therapeutic delay led to high disease activity and poor functional outcome in RA patients.
doi: https://doi.org/10.12669/pjms.37.4.3471
How to cite this:Naeem F, Khan SEA, Saeed MA, Farman S. Diagnostic and therapeutic delay in Rheumatoid Arthritis patients: Impact on disease outcome. Pak J Med Sci. 2021;37(4):1001-1007. doi: https://doi.org/10.12669/pjms.37.4.3471
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The epidermal growth factor (EGF) receptor (EGFR) has been found to be overexpressed in several types of cancer cells, and the regulation of its oncogenic potential has been widely studied. The ...paradigm for EGFR down-regulation involves the trafficking of activated receptor molecules from the plasma membrane, through clathrin-coated pits, and into the cell for lysosomal degradation. We have previously shown that oxidative stress generated by H2O2 results in aberrant phosphorylation of the EGFR. This leads to the loss of c-Cbl-mediated ubiquitination of the EGFR and, consequently, prevents its degradation. However, we have found that c-Cbl-mediated ubiquitination is required solely for degradation but not for internalization of the EGFR under oxidative stress. To further examine the fate of the EGFR under oxidative stress, we used confocal analysis to show that the receptor not only remains co-localized with caveolin-1 at the plasma membrane, but at longer time points, is also sorted to a perinuclear compartment via a clathrin-independent, caveolae-mediated pathway. Our findings indicate that although the EGFR associates with caveolin-1 constitutively, caveolin-1 is hyperphosphorylated only under oxidative stress, which is essential in transporting the EGFR to a perinuclear location, where it is not degraded and remains active. Thus, oxidative stress may have a role in tumorigenesis by not only activating the EGFR but also by promoting prolonged activation of the receptor both at the plasma membrane and within the cell.
Exposure to hydrogen peroxide (H₂O₂), one of the reactive oxidants in the gas phase of cigarette smoke (CS), induces aberrant phosphorylation of the epidermal growth factor receptor (EGFR), resulting ...in the lack of ubiquitination by c-Cbl, and impaired degradation. EGFR activation without the feedback regulation of normal degradation leads to uncontrolled cell growth and tumor promotion. Using immunoprecipitation, immunoblotting, and confocal microscopy, we now demonstrate that the pattern of EGFR activation by CS is similar to H₂O₂. We found that exposure of human airway epithelial cells to CS, as with exposure to H₂O₂, not only results in an increase in EGFR activation over time, but the EGFR activated by H₂O₂ or CS is neither ubiquitinated nor subsequently degraded due to its inability to bind the E3 ubiquitin ligase, c-Cbl, either directly or indirectly via the Grb2 adapter protein. Moreover, the stabilized H₂O₂- and CS-activated EGFR remains plasma membrane-bound, while a population of the receptor is trafficked to a perinuclear region. Concomitantly, CS exposure results in the activation of downstream Akt and ERK1/2 survival and proliferation pathways. Therefore, exposure to CS, like exposure to H₂O₂, results in prolonged signaling by the EGFR and may contribute to uncontrolled lung cell growth.--Khan, E. M., Lanir, R., Danielson, A. R., Goldkorn, T. Epidermal growth factor receptor exposed to cigarette smoke is aberrantly activated and undergoes perinuclear trafficking.
To determine the association of systemic lupus erythematosus disease activity index (SLEDAI) score in pediatric onset SLE (p-SLE) with clinical and laboratory parameters.
This cross sectional ...observational study was conducted at Division of Rheumatology, Fatima Memorial Hospital, Lahore from November 2018 to January 2019. Total 23 patients diagnosed with p-SLE having onset of symptoms at ≤ 18 years of age, irrespective of their current age at presentation, of either gender, fulfilling criteria of 2012 Systemic Lupus International Collaborating Clinics (SLICC) criteria were enrolled. Patients' clinical symptoms and laboratory parameters were reviewed, SLEDAI scores were calculated. Collected Data were entered in proforma and analyzed on SPSS version 23.
There were 91.3% females. Mean age at diagnosis was 11years ± 4years. At presentation patients had hematological involvement 69.6% followed by mucocutaneous symptoms 65.2% and renal involvement 21.6%. ANA by IFA was positive in all, while anti-ds-DNA was positive in 78.3% patients. SLEDAI score was ≥6 in 87% patients, average SLEDAI score was higher in patients with renal involvement (
0.06). Elevated ESR (r=0.48,
=0.02), Anti-dsDNA (r=0.44,
0.05) and low complement levels (
0.03) were significantly positively correlated, while hemoglobin (r= -0.43,
0.04) was negatively correlated with the SLEDAI score.
In this study, patients with Lupus Nephritis had high SLEDAI scores. Elevated Anti-dsDNA titer, ESR, low complement levels and hemoglobin were significantly associated with high SLEDAI scores. We recommend that SLEDAI score should be calculated in p-SLE patients for stringent disease monitoring and treatment.
Objective: To determine the clinical and laboratory features during the disease course in patients of anticytoplasmic antibody (ANCA) associated vasculitis in Pakistani patients presenting to a ...tertiary care center.
Study Design: Case series.
Place and Duration of Study: Fatima Memorial Hospital Shadman Lahore, from Dec 2018 to Mar 2019.
Methodology: A collection of 20 patients regarding demographic data, constitutional symptoms, mucocutaneous symptoms and signs, upper respiratory symptoms, lower respiratory symptoms, orbital and ocular manifestation, cardiovascular, peripheral vascular manifestation, central and peripheral neurologic manifestation, abdominal manifestation and renal manifestation
Results: Sixteen patients (80%) had a diagnosis of Granulomatosis with Polyangiitis, and 4 patients (20%) wereof microscopic polyangiitis. The most common systemic involvement in descending order were constitutionalsymptoms (75%), ear nose and throat symptoms (50%), renal (50%), respiratory (45%), ocular (40%) and neurologic (40%). Most common laboratory abnormalities in our patients included leukocytosis (45%), anemia (35%), hematuria (50%), proteinuria (45%), and elevated serum creatinine (45%). Cytoplasmic-anti cytoplasmic antibody (C-ANCA) was positive in 11 (55%), all cases were of granulomatosis with polyangiitis, P-ANCA was positive in 5 (25%) of all patients, with 4 (100%) in Microscopic polyangiitis. Analysis of Granulomatosis with Polyangiitis according to gender and cytoplasmic-anti cytoplasmic antibody status showed correlation of renal involvement with cytoplasmic-anti cytoplasmic antibody status with statistical significance of p=0.036. Plain chest X-rays showed infiltrates in 2 (10%), nodularity 2 (10%), cavitation in 2 (10%), effusion in 1 (5%), and reticulonodular showing in 1 (5%) patients. High-resolution computed tomography findings included ground-glass opacification in 5...
Background/Aims: We assessed mitochondrial morphology by electron microscopy and the prevalence of a mitochondrial gene deletion in patients with nonalcoholic steatohepatitis (NASH), alcohol-related ...liver disease and non-fatty liver diseases. Respiratory chain function using a cytoplasmic hybrid (cybrid) assay was further studied in NASH patients and healthy controls.
Methods: Electron microscopy was performed in 26 specimens. Fifteen patients were studied by polymerase chain reaction to detect a 520-bp deletion product of the mitochondrial genome (dmtDNA). Cybrids were created by fusion of platelets with anaerobic neuroblastoma cells in six NASH patients and 12 controls.
Results: Eight of ten NASH, one of seven alcoholics and two of nine other patients had linear crystalline inclusions in megamitochondria (
p<0.05). Three of five patients with alcohol-related liver disease had dmtDNA compared to one of five NASH patients and one of five non-steatohepatitis controls. Cybrid respiratory chain function in platelets was not different from that of controls.
Conclusions: Respiratory chain dysfunction, if present in NASH, is not expressed in platelet-derived mitochondria. In contrast to alcohol-related liver disease with active drinking, NASH patients do not commonly express the 5-kb mitochondrial DNA gene deletion in liver tissue. As previously described in early alcohol-related liver disease, crystalline inclusions of unknown composition are seen in hepatic mitochondria in NASH. Their presence suggests either an adaptive process or mitochondrial injury.
Scavenger Receptor B1 has been shown to play a prominent role in the uptake and delivery of vitamin E from HDL and is likely involved in regulating vitamin E in the lung. We have previously ...demonstrated that lung Scavenger Receptor B1 levels (protein and mRNA) are modulated by cigarette smoke in mice and this was accompanied by changes in lung vitamin E. To further characterize the molecular mechanism(s) involved in this process, human alveolar epitheliall cells were exposed to cigarette smoke and Scavenger Receptor B1 cellular levels and distribution were assessed. Results demonstrated that Scavenger Receptor B1 localizes in patches on the cellular membrane and in the perinuclear area of control cells. Upon cigarette smoke exposure, Scavenger Receptor B1 first translocated to the cell surface (within the first 12
h of exposure) and then cell levels (protein and mRNA levels) decreased significantly at 24
h. This decline was accompanied by increased Scavenger Receptor B1 ubiquitination which may explain the decrease in the protein levels. Cigarette smoke induced changes in both sub-cellular redistribution and ubiquitination of Scavenger Receptor B1 together with our previous
in vivo data provides evidence that cigarette smoke exposure may alter lung's ability to control its tocopherol levels.
Apoptosis, or genetically programmed cell death, is a crucial cellular process that maintains the balance between life and death in cells. The precise molecular mechanism of apoptosis signaling and ...the manner in which type 1 and type 2 pathways of the apoptosis signaling network are differentially activated under distinct apoptotic stimuli is poorly understood. Based on Monte Carlo stochastic simulations, we show that the type 1 pathway becomes activated under strong apoptotic stimuli, whereas the type 2 mitochondrial pathway dominates apoptotic signaling in response to a weak death signal. Our results also show signaling in the type 2 pathway is stochastic; the population average over many cells does not capture the cell-to-cell fluctuations in the time course (∼1–10h) of downstream caspase-3 activation. On the contrary, the probability distribution of caspase-3 activation for the mitochondrial pathway shows a distinct bimodal behavior that can be used to characterize the stochastic signaling in type 2 apoptosis and other similar complex signaling processes. Interestingly, such stochastic fluctuations in apoptosis signaling occur even in the presence of large numbers of signaling molecules.
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