Modifiable sleep-related risk factors in infant deaths in Cook County, Illinois.

BACKGROUND: Each year, approximately 3500 infants in the United States die from sleep-related deaths. The number of sleep-related infant deaths has decreased overall since the 1990s, but disparities in sleep-related deaths persist among different populations. The purpose of this study was to determine the most common risk factors and locations in Cook County, Illinois for sleep-related deaths in infants under 6 months of age. METHODS: We conducted a retrospective study among infants less than 6 months of age who died in Cook County, Illinois in 2015 and 2016, in which the manner of death was of undetermined intent with at least one modifiable sleeping risk factor present, as reported by the medical examiner. Data were obtained from the Illinois Violent Death Reporting System (IVDRS), a state-based, anonymous, surveillance system. County trends and circumstances of the deaths were also evaluated. Frequencies, percentages, and Chi-square analysis were used to describe and characterize these deaths. RESULTS: In Cook County in 2015 and 2016, 116 infants less than 6 months of age died where the manner of death was classified as undetermined intent. The median age of death was 2 months. Of these deaths, 63 (54.3%) of the infants were boys. African-American and Hispanic infants comprised 71 (65.7%) and 23 (21.3%) of the deaths, respectively. In 84 (72.4%) of the cases, at least one known sleeping risk factor was present and 56 (66.7%) of the infants who died with a known sleeping risk factor were co-sleeping. Notably, 33 (29.7%) of the deaths in Cook County were clustered within six zip codes. CONCLUSIONS: The majority of infants who died unexpectedly in Cook County in 2015 and 2016 did so in the presence of sleeping risk factors, with co-sleeping being the most common. African-American infants, infants under 2 months of age, and several geographical areas within Chicago appear to be at increased risk. Interventions to target these preventable causes in the populations at increased risk should be instituted to prevent future deaths.

Dr. Jekyll and Mr. Hyde: Oxidizable phenol-generated reactive oxygen species enhance sulforaphane's antioxidant response element activation, even as they suppress Nrf2 protein accumulation.

The transcription factor Nrf2 is a master regulator of antioxidant and cytoprotective genes, binding to antioxidant response elements (AREs) in their promoter regions. Due to the therapeutic role of the Nrf2/ARE system in oxidative homeostasis, its activation has been investigated in many pre-clinical and clinical trials for common chronic diseases. One of the most promising Nrf2 activators is sulforaphane, the subject of over 50 clinical trials. In this work, we examine the effect of reactive oxygen species (ROS) on sulforaphane's Nrf2/ARE activation in the non-tumorigenic keratinocyte cell line HaCaT, with the non-arylating oxidizable phenol, 2,5-di-tert-butylhydroquinone (dtBHQ), as the source of ROS. We find that, in combination with 2.5 µM sulforaphane, dtBHQ markedly enhances ARE-regulated gene expression, including expression of the cytoprotective proteins aldo-keto reductase family 1 member C1 (AKR1C1) and heme oxygenase-1 (HO-1). Additionally, sulforaphane's therapeutic window is widened by 12.5 µM dtBHQ. Our data suggest that H2O2 generated by dtBHQ oxidation is responsible for these effects, as shown by inclusion of catalase and by co-treatment with sulforaphane and H2O2. While sulforaphane treatment causes Nrf2 protein to accumulate as expected, interestingly, dtBHQ and H2O2 appear to act on targets downstream of Nrf2 protein accumulation to enhance sulforaphane's ARE-regulated gene expression. Inclusion of dtBHQ or H2O2 with sulforaphane does not increase Nrf2 protein levels, and catalase has little effect on Nrf2 protein levels in the presence of sulforaphane and dtBHQ. Surprisingly, dtBHQ suppresses Nrf2 protein synthesis. Inclusion of a superoxide dismutase mimetic with sulforaphane and dtBHQ partly rescues Nrf2 suppression and significantly further increases sulforaphane's efficacy for ARE-reporter expression. Thus, there is a "Dr. Jekyll and Mr. Hyde" effect of ROS: ROS enhance sulforaphane's ARE-regulated gene expression even as they also inhibit Nrf2 protein synthesis. This unexpected finding reveals the degree to which targets in the ARE pathway downstream of Nrf2 protein accumulation contribute to gene expression. The results presented here provide a model system for significant enhancement of sulforaphane's potency with small molecule co-treatment.

High-fidelity Glucagon-CreER mouse line generated by CRISPR-Cas9 assisted gene targeting.

OBJECTIVE: α-cells are the second most prominent cell type in pancreatic islets and are responsible for producing glucagon to increase plasma glucose levels in times of fasting. α-cell dysfunction and inappropriate glucagon secretion occur in both type 1 and type 2 diabetes. Thus, there is growing interest in studying both normal function and pathophysiology of α-cells. However, tools to target gene ablation or activation specifically of α-cells have been limited, compared to those available for ß-cells. Previous Glucagon-Cre and Glucagon-CreER transgenic mouse lines have suffered from transgene silencing, and the only available Glucagon-CreER "knock-in" mouse line results in glucagon haploinsufficiency, which can confound the interpretation of gene deletion analyses. Therefore, we sought to develop a Glucagon-CreERT2 mouse line that would maintain normal glucagon expression and would be less susceptible to transgene silencing. METHODS: We utilized CRISPR-Cas9 technology to insert an IRES-CreERT2 sequence into the 3' UTR of the Glucagon (Gcg) locus in mouse embryonic stem cells (ESCs). Targeted ESC clones were then injected into mouse blastocysts to obtain Gcg-CreERT2 mice. Recombination efficiency in GCG+ pancreatic α-cells and glucagon-like peptide 1 positive (GLP1+) enteroendocrine L-cells was measured in Gcg-CreERT2 ;Rosa26-LSL-YFP mice injected with tamoxifen during fetal development and adulthood. RESULTS: Tamoxifen injection of Gcg-CreERT2 ;Rosa26-LSL-YFP mice induced high recombination efficiency of the Rosa26-LSL-YFP locus in perinatal and adult α-cells (88% and 95%, respectively), as well as in first-wave fetal α-cells (36%) and adult enteroendocrine L-cells (33%). Mice homozygous for the Gcg-CreERT2 allele were phenotypically normal. CONCLUSIONS: We successfully derived a Gcg-CreERT2 mouse line that expresses CreERT2 in pancreatic α-cells and enteroendocrine L-cells without disrupting preproglucagon gene expression. These mice will be a useful tool for performing temporally controlled genetic manipulation specifically in these cell types.