The functional role of L-fucose on dendritic cell function and polarization.

Despite significant advances in the development and refinement of immunotherapies administered to combat cancer over the past decades, a number of barriers continue to limit their efficacy. One significant clinical barrier is the inability to mount initial immune responses towards the tumor. As dendritic cells are central initiators of immune responses in the body, the elucidation of mechanisms that can be therapeutically leveraged to enhance their functions to drive anti-tumor immune responses is urgently needed. Here, we report that the dietary sugar L-fucose can be used to enhance the immunostimulatory activity of dendritic cells (DCs). L-fucose polarizes immature myeloid cells towards specific DC subsets, specifically cDC1 and moDC subsets. In vitro, L-fucose treatment enhances antigen uptake and processing of DCs. Furthermore, our data suggests that L-fucose-treated DCs increase stimulation of T cell populations. Consistent with our functional assays, single-cell RNA sequencing of intratumoral DCs from melanoma- and breast tumor-bearing mice confirmed transcriptional regulation and antigen processing as pathways that are significantly altered by dietary L-fucose. Together, this study provides the first evidence of the ability of L-fucose to bolster DC functionality and provides rational to further investigate how L-fucose can be used to leverage DC function in order to enhance current immunotherapy.

Gene knockout of RNA binding motif 5 in the brain alters RIMS2 protein homeostasis in the cerebellum and Hippocampus and exacerbates behavioral deficits after a TBI in mice.

RNA binding motif 5 (RBM5) is a tumor suppressor in cancer but its role in the brain is unclear. We used conditional gene knockout (KO) mice to test if RBM5 inhibition in the brain affects chronic cortical brain tissue survival or function after a controlled cortical impact (CCI) traumatic brain injury (TBI). RBM5 KO decreased baseline contralateral hemispheric volume (p < 0.0001) and exacerbated ipsilateral tissue loss at 21 d after CCI in male mice vs. wild type (WT) (p = 0.0019). CCI injury, but not RBM5 KO, impaired beam balance performance (0-5d post-injury) and swim speed on the Morris Water Maze (MWM) (19-20d) (p < 0.0001). RBM5 KO was associated with mild learning impairment in female mice (p = 0.0426), reflected as a modest increase in escape latency early in training (14-18d post-injury). However, KO did not affect spatial memory at 19d post-injury in male or in female mice but it was impaired by CCI in females (p = 0.0061). RBM5 KO was associated with impaired visual function in male mice on the visible platform test at 20d post-injury (p = 0.0256). To explore signaling disturbances in KOs related to behavior, we first cross-referenced known brain-specific RBM5-regulated gene targets with genes in the curated RetNet database that impact vision. We then performed a secondary literature search on RBM5-regulated genes with a putative role in hippocampal function. Regulating synaptic membrane exocytosis 2 (RIMS) 2 was identified as a gene of interest because it regulates both vision and hippocampal function. Immunoprecipitation and western blot confirmed protein expression of a novel ~170 kDa RIMS2 variant in the cerebellum, and in the hippocampus, it was significantly increased in KO vs WT (p < 0.0001), and in a sex-dependent manner (p = 0.0390). Furthermore, male KOs had decreased total canonical RIMS2 levels in the cerebellum (p = 0.0027) and hippocampus (p < 0.0001), whereas female KOs had increased total RIMS1 levels in the cerebellum (p = 0.0389). In summary, RBM5 modulates brain function in mammals. Future work is needed to test if RBM5 dependent regulation of RIMS2 splicing effects vision and cognition, and to verify potential sex differences on behavior in a larger cohort of mice.

Neuronal RBM5 modulates cell signaling responses to traumatic and hypoxic-ischemic injury in a sex-dependent manner.

It is not clear if inhibiting the pro-death gene RNA binding motif 5 (RBM5) is neuroprotective in isolated primary neurons or if it regulates cell survival in a sex-dependent manner. Here we established sex-dichotomized primary cortical neuron cultures from transgenic mice harboring a floxed RBM5 gene-trap. Lentivirus-mediated expression of CRE was used to silence RBM5 expression. Male and female neurons were maintained in next-generation Neurobasal-Plus media and subjected to a mechanical stretch-injury (to model traumatic brain injury) or oxygen-glucose deprivation/OGD (to model ischemia). RBM5 KO did not affect 24 h post-injury survival as determined by lactate dehydrogenase (LDH) release, in either paradigm. In contrast, female KO neurons had increased spectrin breakdown products post-insult (in both models). Furthermore, in OGD, RBM5 KO in male neurons exacerbated injury-induced downregulation of pro-survival AKT activation (pAKT473) but conversely led to pAKT473 sparing in female neurons. Moreover, global proteomics identified 19 differentially expressed (DE) proteins in OGD-injured male neurons, and 102 DE proteins in injured female neurons. Two novel RBM5-regulated proteins (PIGQ and EST1C) were identified in injured male KO neurons, and 8 novel proteins identified in injured female KO neurons (S35A5, DHTK1, STX3, IF3M, RN167, K1C14, DYHS, and MED13). In summary, RBM5 inhibition does not modify neuronal survival in primary mouse neurons in 2 clinically relevant models of excitotoxic insult, but RBM5 does regulate intracellular responses to injury in a sex-dependent manner.

RNA Binding Motif 5 Gene Deletion Modulates Cell Signaling in a Sex-Dependent Manner but Not Hippocampal Cell Death.

RNA-binding motif 5 (RBM5) is a pro-death tumor suppressor gene in cancer cells. It remains to be determined if it is neurotoxic in the brain or rather if it plays a fundamentally different role in the central nervous system (CNS). Brain-specific RBM5 knockout (KO) mice were given a controlled cortical impact (CCI) traumatic brain injury (TBI). Markers of acute cellular damage and repair were measured in hippocampal homogenates 48 h post-CCI. Hippocampal CA1/CA3 cell counts were assessed 7 days post-CCI to determine if early changes in injury markers were associated with histological outcome. No genotype-dependent differences were found in the levels of apoptotic markers (caspase 3, caspase 6, and caspase 9). However, KO females had a paradoxical increase in markers of pro-death calpain activation (145/150-spectrin and breakdown products [SBDP]) and in DNA repair/survival markers. (pH2A.x and pCREB). CCI-injured male KOs had a significant increase in phosphorylated calcium/calmodulin-dependent protein kinase II (pCaMKII). Despite sex/genotype-dependent differences in KOs in the levels of acute cell signaling targets involved in cell death pathways, 7 day hippocampal neuronal survival did not differ from that of wild types (WTs). Similarly, no differences in astrogliosis were observed. Finally, gene analysis revealed increased estrogen receptor α (ERα) levels in the KO hippocampus in females and may suggest a novel mechanism to explain sex-dimorphic effects on cell signaling. In summary, RBM5 inhibition did not affect hippocampal survival after a TBI in vivo but did modify targets involved in neural signal transduction/Ca2+ signaling pathways. Findings here support the view that RBM5 may serve a purpose in the CNS that is dissimilar from its traditional pro-death role in cancer.

Adherence to a standardized infection reduction bundle decreases surgical site infections after colon surgery: a retrospective cohort study on 526 patients.

BACKGROUND: Colon surgical site infections (SSI) are detrimental to patient safety and wellbeing. To achieve clinical excellence, our hospital set to improve patient safety for those undergoing colon surgery. Our goal was to implement a perioperative SSI prevention bundle for all colon surgeries to reduce colon surgery SSI rates. METHODS: This retrospective cohort study evaluated the impact of implementing a perioperative SSI prevention bundle in patients undergoing colon surgery at Banner University Medical Center - Tucson. We compared SSI rates between the Pre- (1/1/2016 to 12/31/2016) and post-bundle (1/1/2017 to 12/31/2017) cohorts using a chi-square test. RESULTS: In total, we included 526 consecutive patients undergoing colon surgery in our study cohort; 277 pre-bundle and 249 post-bundle implementation. The unadjusted SSI rates were 8.7 % and 1.2 %, pre- and post-bundle, respectively. Our CMS reportable standard infection rate decreased by 85.4 % from 3.08 to 0.45 after implementing our SSI prevention bundle. CONCLUSIONS: Implementing a standardized colon SSI prevention bundle reduces the overall 30-day colon SSI rates and national standardized infection rates. We recommend implementing colon SSI reduction bundles to optimize patient safety and minimize colon surgical site infections.

Transforming hemoglobin measurement in trauma patients: noninvasive spot check hemoglobin.

BACKGROUND: Technological advances now allow for noninvasive Hbg measurements. Previous studies have reported on the efficacy of continuous noninvasive Hgb devices. Recently, a new device, Pronto-7, a spot check pulse CO-oximeter has become available. The aim of our study was to assess noninvasive Hgb measurement in trauma patients. METHODS: We performed a prospective cohort analysis of all trauma patients presenting to our Level I trauma center. Invasive Hgb and spot check Hgb measurements were obtained simultaneously at presentation. Spot check was measured 2 times with each invasive Hgb value. Normal Hgb was defined as >8 mg/dL. Spearman correlation and Bland-Altman analysis was performed. RESULTS: A total of 525 patients had attempted spot check Hgb measurements with a success rate of 86% (n = 450). A total of 450 invasive and 1,350 spot check Hgb measurements were obtained. Mean ± SD age was 41 ± 21 years, 74% were male, and mean Injury Severity Score was 21 ± 13. Thirty-eight percent (n = 173) of patients had Hgb ≤8 mg/dL at presentation. Mean invasive Hgb was 11.5 ± 4.36 g/dL, mean spot check Hgb 11.1 ± 3.60 g/dL, and mean difference was 0.3 ± 1.3 g/dL. Spot check Hgb values had strong correlation with invasive Hgb measurements (R(2) = 0.77; R = 0.86; p = 0.04) with 76% accuracy and 95.4% sensitivity. CONCLUSIONS: Spot check Hgb monitoring had excellent correlation with invasive Hgb measurements. Application of spot check has more clinical use as compared with previous continuous Hgb monitoring. This novel technology allows immediate and accurate Hgb measurements in trauma patients.

Hypothermia in organ donation: a friend or foe?

BACKGROUND: Hypothermia is a known predictor of mortality in trauma patients; however, its impact on organ procurement has not been defined. The aim of this study was to assess the effect of hypothermia on organ procurement. We hypothesized that admission hypothermia impedes successful organ procurement. METHODS: We performed a 5-year retrospective analysis of all trauma patients approached for organ donation. Hypothermia was defined as a core body temperature 36°C/97°F or less. The two groups (hypothermic [HT] vs. nonhypothermic [non-HT]) were matched in a 1:1 ratio using propensity score matching for age, sex, admission Glasgow Coma Scale (GCS) score, systolic blood pressure, international normalized ratio, and Injury Severity Score (ISS). Primary outcome measures were eligibility for organ donation and solid organ procurement. Secondary outcome measures were blood product and vasopressor requirements. RESULTS: This study was composed of 537 brain-dead patients, of whom 416 (HT, 208; non-HT, 208) were included in the analysis. The mean (SD) age was 40.5 (23.7) years, 75% were male, mean (SD) temperature was 36.6°C (1.7°C), and mean (SD) systolic blood pressure was 75.35 (68.7) mm Hg. Patients who were hypothermic on presentation were less likely to be eligible for organ donation (44.7% vs. 96%, p ≤ 0.001), and they donated fewer organs per donor (p = 0.04). HT patients required more units of fresh frozen plasma (p = 0.04) and greater mean dose of dopamine (p = 0.03) and vasopressin (p = 0.03) compared with the non-HT patients. CONCLUSION: Admission hypothermia is associated with decreased organ donation in potential organ donors independent of admission coagulopathy, hypotension, and injury severity. Early correction of hypothermia may improve organ donation in trauma patients. LEVEL OF EVIDENCE: Epidemiologic/prognostic study, level III.

Continuous noninvasive hemoglobin monitor from pulse ox: ready for prime time?

BACKGROUND: Advances in technology have allowed for continuous noninvasive hemoglobin monitoring (SpHb), which may enable earlier detection of hemorrhage and more efficient surgical and/or blood transfusion management. The use of SpHb has not been described in the trauma population. The purpose of the present study was to evaluate the accuracy of a SpHb measurement device in severely injured trauma patients. METHODS: We performed a prospective cohort analysis of severely injured trauma patients admitted to the intensive care unit (ICU) at our level I trauma center over a 6 month period. Serial IHb (invasive hemoglobin) levels and SpHb for the first 72 h were measured. Each SpHb measurement was matched with a corresponding IHb measurement. We defined normal Hgb as >8 mg/dL and low Hgb as <8 mg/dL. Data were then grouped based on Hgb level. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and Spearman correlation coefficient plot were calculated. RESULTS: A total of 23 trauma patients with 89 data pairs were reviewed. Eighty-six percent of the patients were male with a mean age of 32 years and a mean injury severity score (ISS) of 21.1 ± 14. Invasive hemoglobin had a range of 7.2-16.9 and SpHb had a range of 3.3-15.2. The average mean and difference between IHb and SpHb were 10.7 and 1, respectively. Continuous noninvasive hemoglobin measurement did not record data points 13.5% of the time. The Spearman correlation plot revealed a correlation of R = 0.670 (p < 0.001). After dichotomization with Hgb > 8, SpHb was found to have a sensitivity of 91%, PPV 96%, specificity 40%, NPV 20%, and an accuracy of 88%. CONCLUSIONS: The continuous noninvasive hemoglobin monitor does not appear to represent serum hemoglobin levels accurately in severely injured trauma patients. However, we were able to identify utility for this noninvasive tool when Hgb was dichotomized into normal or low levels.