The endoplasmic reticulum (ER) has the ability to signal organelle dysfunction via a complex signaling network known as the unfolded protein response (UPR). In this work, hamster fibroblast cells exhibiting moderate levels of ER stress were compared to those exhibiting severe ER stress. Inhibition of N-linked glycosylation was accomplished via a temperature-sensitive mutation in the Dad1 subunit of the oligosaccharyltransferase (OST) complex or by direct inhibition with tunicamycin (Tm). Temperature shift (TS) treatment generated weak activation of ER stress signaling when compared to doses of Tm that are typically used in ER stress studies (500-1000 nM). A dose-response analysis of key ER stress signaling mediators, inositol-requiring enzyme 1 (IRE1) and protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK), revealed 20-40 nM of Tm to generate activation intensity similar to TS treatment. In parental BHK21 cells, moderate (20-40 nM) and high doses (200-1000 nM) of Tm were compared to identify physiological and signaling-based differences in stress response. Inhibition of ER Ca release via ITPR activity with 2-aminoethoxydiphenyl borate (2-APB) or Xestospongin C (XeC) was sufficient to protect against apoptosis induced by moderate but not higher doses of Tm. Analysis of kinase activation over a range of Tm exposures revealed the p38 stress-activated protein kinase (SAPK) to display increasing activation with Tm dosage. Interestingly, Tm induced the extracellular regulated kinases (Erk1/2) only at moderate doses of Tm. Inhibition of ER transmembrane stress sensors (IRE1, PERK) or cytosolic signaling mediators (p38, Jnk1, Erk1/2) was used to evaluate pathways involved in apoptosis activation during ER stress. Inhibition of either PERK or p38 was sufficient to reduce cell death and apoptosis induced by moderate, but not high, doses of Tm. During ER stress, cells exhibited a rapid decline in anti-apoptotic Mcl-1 and survivin proteins. Inhibition of PERK was sufficient to block this affect. This work reveals moderate doses of ER stress to generate patterns of stress signaling that are distinct from higher doses and that apoptosis activation at moderate levels of stress are dependent upon PERK and p38 signaling. Studies exploring ER stress signaling should recognize that this signaling acts as a rheostat rather than a simple switch, behaving distinctively in a dose-dependent manner.
UTI is one of the most common causes of outpatient antibiotic use, and rising antibiotic resistance threatens the ability to control UTI unless alternative treatments are developed. Bacteriophage (phage) therapy is gaining renewed interest; however, much like with antibiotics, bacteria can readily become resistant to phages.
Multiple Sclerosis (MS) is a progressive neurodegenerative disease that affects more than 2 million people worldwide. Increasing knowledge about MS in different populations has advanced our understanding of disease epidemiology and variation in the natural history of MS among White and minority populations. In addition to differences in incidence, African American (AA) and Hispanic patients have greater disease burden and disability in earlier stages of disease compared to White patients. To further characterize MS in AA and Hispanic populations, we conducted a retrospective chart analysis of 112 patients treated at an MS center in Houston, Texas. Here, we describe similarities and differences in clinical presentation, MRI findings, treatment regimens, disability progression, and relapse rate. While we found several similarities between the groups regarding mean age, disability severity, and degree of brain atrophy at diagnosis, we also describe a few divergences. Interestingly, we found that patients who were evaluated by a neurologist at symptom onset had significantly decreased odds of greater disability [defined as Expanded Disability Status Scale (EDSS) > 4.5] at last presentation compared to patients who were not evaluated by a neurologist (OR: 0.04, 95% CI: 0.16–0.9). We also found that active smokers had significantly increased odds of greater disability both at diagnosis and at last clinical encounter compared to nonsmokers (OR: 2.44, 95% CI: 1.10–7.10, OR= 2.44, 95% CI: 1.35–6.12, p = 0.01, respectively). Additionally, we observed significant differences in treatment adherence between groups. Assessment of the degree of brain atrophy and progression over time, along with an enumeration of T1, T2, and gadolinium-enhancing brain lesions, did not reveal differences across groups.
Objectives: Racial disparities in preexisting diabetes mellitus (PDM) and gestational diabetes mellitus (GDM) remain largely unexplored. We examined national PDM and GDM prevalence trends by race/ ethnicity and the association between these conditions and fetal death.Methods: This was a retrospective cross-sectional analysis of 69,539,875 pregnancy-related hospitalizations from 2002 to 2017 including 674,040 women with PDM (1.0%) and 2,960,797 (4.3%) with GDM from the US Nationwide Inpatient Sample Survey. Joinpoint regression was used to evaluate trends in prevalence. Survey logistic regression was used to evaluate the association between exposures (PDM and GDM) and outcome.Results: Overall, the average annual increase in prevalence was 5.2% (95% confidence interval [CI] 4.2-6.2) for GDM and 1.0% (95% CI −0.1 to 2.0) for PDM, during the study period. Hispanic (average annual percentage change 5.3, 95% CI 3.6 − 7.1) and non-Hispanic Black (average annual percentage change 0.9, 95% CI 0.1 − 1.7) women had the highest average annual percentage increase in the prevalence of GDM and PDM, respectively. After adjustment, the odds of stillbirth were highest for Hispanic women with PDM (odds ratio 2.41, 95% CI 2.23-2.60) and decreased for women with GDM (odds ratio 0.51, 95% CI 0.50-0.53), irrespective of race/ethnicity.Conclusions: PDM and GDM prevalence is increasing in the United States, with the highest average annual percentage changes seen among minority women. Furthermore, the reasons for the variation in the occurrence of stillbirths among mothers with PDM and GDM by race/ethnicity are not clear and warrant additional research.
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