Reducing acetylated tau is neuroprotective in brain injury

Traumatic brain injury (TBI) is the largest non-genetic, non-aging related risk factor for Alzheimer's disease (AD). We report here that TBI induces tau acetylation (ac-tau) at sites acetylated also in human AD brain. This is mediated by S-nitrosylated-GAPDH, which simultaneously inactivates Sirtuin1 deacetylase and activates p300/CBP acetyltransferase, increasing neuronal ac-tau. Subsequent tau mislocalization causes neurodegeneration and neurobehavioral impairment, and ac-tau accumulates in the blood. Blocking GAPDH S-nitrosylation, inhibiting p300/CBP, or stimulating Sirtuin1 all protect mice from neurodegeneration, neurobehavioral impairment, and blood and brain accumulation of ac-tau after TBI. Ac-tau is thus a therapeutic target and potential blood biomarker of TBI that may represent pathologic convergence between TBI and AD. Increased ac-tau in human AD brain is further augmented in AD patients with history of TBI, and patients receiving the p300/CBP inhibitors salsalate or diflunisal exhibit decreased incidence of AD and clinically diagnosed TBI.

Coagulation Differences Detectable in Deep and Lobar Primary Intracerebral Hemorrhage Using Thromboelastography

BACKGROUND

There are radiographic and clinical outcome differences between patients with deep and lobar intracerebral hemorrhage (ICH) locations. Pilot studies suggest that there may be functional coagulation differences between these locations detectable using whole blood coagulation testing.

OBJECTIVE

To confirm the presence of interlocation functional coagulation differences using a larger cohort of deep and lobar ICH patients receiving whole blood coagulation testing: thromboelastography (TEG; Haemonetics).

METHODS

Clinical and laboratory data were prospectively collected between 2009 and 2018 for primary ICH patients admitted to a tertiary referral medical center. Deep and lobar ICH patients receiving admission TEG were analyzed. Patients with preceding anticoagulant use and/or admission coagulopathy (using prothrombin time/partial thromboplastin time/platelet count) were excluded. Linear regression models assessed the association of ICH location (independent variable) with TEG and traditional plasma coagulation test results (dependent variable) after adjusting for baseline hematoma size, age, sex, and stroke severity.

RESULTS

We identified 154 deep and 53 lobar ICH patients who received TEG. Deep ICH patients were younger and had smaller admission hematoma volumes (median: 16 vs 29 mL). Adjusted multivariable linear regression analysis revealed longer TEG R times (0.57 min; 95% CI: 0.02-1.11; P = .04), indicating longer clot formation times, in deep compared to lobar ICH. No other TEG parameter or plasma-based coagulation differences were seen.

CONCLUSION

We identified longer clot formation times, suggesting relative coagulopathy in deep compared to lobar ICH confirming results from prior work. Further work is required to elucidate mechanisms for these differences and whether ICH location should be considered in future coagulopathy treatment paradigms for ICH.

Abstract TP447: Coagulation Differences Between Deep and Lobar Intracerebral Hemorrhage Detected by Thromboelastography

Introduction: Despite smaller baseline hematoma volumes, deep primary intracerebral hemorrhage (ICH) is known to have worse clinical outcomes and preliminary evidence of more hematoma expansion compared to lobar ICH. This is not thought to be related to differences in functional coagulation as prior studies have not identified differences in traditional, plasma-based coagulation tests between these locations. We investigated for clotting differences between deep and lobar ICH using Thromboelastography (TEG: whole-blood coagulation assessment).

Methods: Clinical, radiographic and laboratory data was prospectively collected between 2009-2018 for primary ICH patients admitted to University of Texas Health Sciences Center at Houston. Deep and lobar ICH patients, without preceding history of anticoagulation use or coagulopathy on admission testing, who received admission TEG and traditional plasma coagulation tests were included for analysis. Patients receiving hemorrhage reversal transfusions prior to TEG were excluded. Multivariable linear regression assessed the association of ICH location with functional coagulation tests after adjusting for age, sex, NIHSS, and baseline hematoma volume.

Results: Of 207 ICH patients included for analysis, there were 154 (74%) deep and 53 (26%) lobar ICH. Deep ICH patients were significantly younger (mean: 56 vs 68 years), had higher admission systolic blood pressures (mean: 200 vs 182mmHg) and smaller admission hematoma volumes (median: 16.2 vs 28.7mL) than lobar ICH patients. Deep ICH had longer TEG R times (mean: 5.1 vs 4.4 minutes) indicating a slower and less optimal time to clot formation compared to lobar ICH. After controlling for potential confounders, the adjusted mean R times continued to be longer in deep compared to lobar ICH by 0.57 minutes (95% CI 0.02-1.11, p=0.04).

Conclusions: Our findings suggest that there may be functional coagulation differences detected with whole blood coagulation testing between deep and lobar ICH. Further work is needed to determine whether whole blood coagulation testing to assess coagulopathy after ICH should play a role in hemorrhage reversal treatment paradigms.

Horizontal Transmission of "Candidatus Liberibacter solanacearum" by Bactericera cockerelli (Hemiptera: Triozidae) on Convolvulus and Ipomoea (Solanales: Convolvulaceae)

"Candidatus Liberibacter solanacearum" (Proteobacteria) is an important pathogen of solanaceous crops (Solanales: Solanaceae) in North America and New Zealand, and is the putative causal agent of zebra chip disease of potato. This phloem-limited pathogen is transmitted to potato and other solanaceous plants by the potato psyllid, Bactericera cockerelli (Hemiptera: Triozidae). While some plants in the Convolvulaceae (Solanales) are also known hosts for B. cockerelli, previous efforts to detect Liberibacter in Convolvulaceae have been unsuccessful. Moreover, studies to determine whether Liberibacter can be acquired from these plants by B. cockerelli are lacking. The goal of this study was to determine whether horizontal transmission of Liberibacter occurs among potato psyllids on two species of Convolvulaceae, sweet potato (Ipomoea batatas) and field bindweed (Convolvulus arvensis), which grows abundantly in potato growing regions of the United States. Results indicated that uninfected psyllids acquired Liberibacter from both I. batatas and C. arvensis if infected psyllids were present on plants concurrently with the uninfected psyllids. Uninfected psyllids did not acquire Liberibacter from plants if the infected psyllids were removed from the plants before the uninfected psyllids were allowed access. In contrast with previous reports, PCR did detect the presence of Liberibacter DNA in some plants. However, visible amplicons were faint and did not correspond with acquisition of the pathogen by uninfected psyllids. None of the plants exhibited disease symptoms. Results indicate that horizontal transmission of Liberibacter among potato psyllids can occur on Convolvulaceae, and that the association between Liberibacter and Convolvulaceae merits additional attention.