Altered peripheral taste function in a mouse model of inflammatory bowel disease

Increased sugar intake and taste dysfunction have been reported in patients with inflammatory bowel disease (IBD), a chronic disorder characterized by diarrhea, pain, weight loss and fatigue. It was previously unknown whether taste function changes in mouse models of IBD. Mice consumed dextran sodium sulfate (DSS) during three 7-day cycles to induce chronic colitis. DSS-treated mice displayed signs of disease, including significant weight loss, diarrhea, loss of colon architecture, and inflammation of the colon. After the last DSS cycle we assessed taste function by recording electrophysiological responses from the chorda tympani (CT) nerve, which transmits activity from lingual taste buds to the brain. DSS treatment significantly reduced neural taste responses to natural and artificial sweeteners. Responses to carbohydrate, salt, sour or bitter tastants were unaffected in mice with colitis, but umami responses were modestly elevated. DSS treatment modulated the expression of receptor subunits that transduce sweet and umami stimuli in oral taste buds as a substrate for functional changes. Dysregulated systemic cytokine responses or dysbiosis that occurs during chronic colitis may be upstream from changes in oral taste buds. We demonstrate for the first time that colitis alters taste input to the brain, which could exacerbate malnutrition in IBD patients.

Altered peripheral taste function in a mouse model of inflammatory bowel disease

Increased sugar intake and taste dysfunction have been reported in patients with inflammatory bowel disease (IBD), a chronic disorder characterized by diarrhea, pain, weight loss and fatigue. It was previously unknown whether taste function changes in mouse models of IBD. Mice consumed dextran sodium sulfate (DSS) during three 7-day cycles to induce chronic colitis. DSS-treated mice displayed signs of disease, including significant weight loss, diarrhea, loss of colon architecture, and inflammation of the colon. After the last DSS cycle we assessed taste function by recording electrophysiological responses from the chorda tympani (CT) nerve, which transmits activity from lingual taste buds to the brain. DSS treatment significantly reduced neural taste responses to natural and artificial sweeteners. Responses to carbohydrate, salt, sour or bitter tastants were unaffected in mice with colitis, but umami responses were modestly elevated. DSS treatment modulated the expression of receptor subunits that transduce sweet and umami stimuli in oral taste buds as a substrate for functional changes. Dysregulated systemic cytokine responses, or dysbiosis that occurs during chronic colitis may be upstream from changes in oral taste buds. We demonstrate for the first time that colitis alters taste input to the brain, which could exacerbate malnutrition in IBD patients.

Interleukin (IL)-1 Receptor Signaling Is Required for Complete Taste Bud Regeneration and the Recovery of Neural Taste Responses following Axotomy

Experimental or traumatic nerve injury causes the degeneration of associated taste buds. Unlike most sensory systems, the sectioned nerve and associated taste buds can then regenerate, restoring neural responses to tastants. It was previously unknown whether injury-induced immune factors mediate this process. The proinflammatory cytokines, interleukin (IL)-1α and IL-1β, and their requisite receptor are strongly expressed by anterior taste buds innervated by the chorda tympani nerve. We tested taste bud regeneration and functional recovery in mice lacking the IL-1 receptor. After axotomy, the chorda tympani nerve regenerated but was initially unresponsive to tastants in both WT and Il1r KO mice. In the absence of Il1r signaling, however, neural taste responses remained minimal even >8 weeks after injury in both male and female mice, whereas normal taste function recovered by 3 weeks in WT mice. Failed recovery was because of a 57.8% decrease in regenerated taste buds in Il1r KO compared with WT axotomized mice. Il1a gene expression was chronically dysregulated, and the subset of regenerated taste buds were reinnervated more slowly and never reached full volume as progenitor cell proliferation lagged in KO mice. Il1r signaling is thus required for complete taste bud regeneration and the recovery of normal taste transmission, likely by impairing taste progenitor cell proliferation. This is the first identification of a cytokine response that promotes taste recovery. The remarkable plasticity of the taste system makes it ideal for identifying injury-induced mechanisms mediating successful regeneration and recovery.SIGNIFICANCE STATEMENT Taste plays a critical role in nutrition and quality of life. The adult taste system is highly plastic and able to regenerate following the disappearance of most taste buds after experimental nerve injury. Several growth factors needed for taste bud regeneration have been identified, but we demonstrate the first cytokine pathway required for the recovery of taste function. In the absence of IL-1 cytokine signaling, taste bud regeneration is incomplete, preventing the transmission of taste activity to the brain. These results open a new direction in revealing injury-specific mechanisms that could be harnessed to promote the recovery of taste perception after trauma or disease.

Deferoxamine prevents poststroke memory impairment in female diabetic rats: potential links to hemorrhagic transformation and ferroptosis

Diabetes increases the risk of poststroke cognitive impairment (PSCI). Greater hemorrhagic transformation (HT) after stroke is associated with vasoregression and cognitive decline in male diabetic rats. Iron chelator deferoxamine (DFX) prevents vasoregression and improves outcomes. Although diabetic female rats develop greater HT, its impact on poststroke cerebrovascularization and cognitive outcomes remained unknown. We hypothesized that diabetes mediates pathological neovascularization, and DFX attenuates poststroke cerebrovascular remodeling and improves neurological outcomes in female diabetic rats. Female control and diabetic animals were treated with DFX or vehicle for 7 days after stroke. Vascular indices, microglial activation, and blood-brain barrier (BBB) integrity were evaluated on day 14. Results from diabetic female rats were partially compared with our previously published findings in male counterparts. Hemin-induced programmed cell death was studied in male and female brain microvascular endothelial cell lines (BMVEC). There was no vasoregression after stroke in either control or diabetic female animals. DFX prevented diabetes-mediated gliovascular remodeling and compromised BBB integrity while improving memory function in diabetes. Comparisons of female and male rats indicated sex differences in cognitive and vascular outcomes. Hemin mediated ferroptosis in both male and female BMVECs. DFX improved survival but had differential effects on ferroptosis signaling in female and male cells. These results suggest that stroke and associated HT do not affect cerebrovascularization in diabetic female rats, but iron chelation may provide a novel therapeutic strategy in the prevention of poststroke memory impairment in females with diabetes via the preservation of gliovascular integrity and improvement of endothelial cell survival.NEW & NOTEWORTHY The current study shows for the first time that diabetes does not promote aberrant cerebrovascularization in female rats. This contrasts with what we reported in male animals in various diabetes models. Deferoxamine preserved recognition memory function in diabetic female animals after stroke. The effect(s) of stroke and deferoxamine on cerebrovascular density and microglial activation also appear(s) to be different in female diabetic rats. Lastly, deferoxamine exerts detrimental effects on animals and BMVECs under control conditions.

[Clinical value of ultrasound-guided radiofrequency ablation in the treatment of retroperitoneal tumors]

Objective: To explore the clinical value of ultrasound-guided radiofrequency ablation in the treatment of retroperitoneal tumors. Methods: The clinical data of 13 patients with retroperitoneal tumors treated with ultrasound-guided radiofrequency ablation in the First Affiliated Hospital of Zhengzhou University from January 2018 to January 2020 were analyzed retrospectively. The ablation effect was evaluated and the postoperative complications were observed. The changes of tumor volume before and after radiofrequency ablation were compared. Results: The symptoms of pain and dyspepsia were significantly improved after radiofrequency ablation, and the hospital stay was (9.2±2.9) days. The tumor was ablated completely in 10 cases, tumor residual in 1 case and tumor metastasis in 2 cases. One patient had postoperative duodenal perforation complicated with intra-abdominal infection, and no serious complications occurred in other patients. There were 20 lesions in 13 patients. The maximum diameter of 20 lesions before operation and 1, 3, 6 months after operation were (39.5±15.9) mm, (30.6±4.9)mm, (15.6±7.7) mm and (9.9±3.1) mm, respectively, the maximum diameters of 1, 3 and 6 months after operation were smaller than that before operation (P<0.05). Conclusion: Ultrasound-guided radiofrequency ablation is a real-time, accurate, safe and effective minimally invasive treatment with few complications, and has a high clinical value for retroperitoneal tumors.

Stimulation of angiotensin II receptor 2 preserves cognitive function and is associated with an enhanced cerebral vascular density after stroke

Angiotensin signaling is known to be sexually dimorphic. Although it is a well-studied target for intervention in stroke and cognitive impairment, female studies are rare. With females suffering a disproportionately greater negative impact of stroke and dementia vs. males, effective interventions are of utmost urgency. The aim of the current study was to determine the impact of activation of the angiotensin II type 2 receptor (AT2R) with the agonist compound 21 (C21) on the development of post-stroke cognitive impairment, after experimental ischemic stroke. Ovariectomized (OVX) spontaneously hypertensive rats (SHRs) were subjected to 1 h of middle cerebral artery occlusion (MCAO). At 24 h, rats with a significant neurologic deficit were randomized to receive either saline or C21 (0.03 mg/kg/day) intraperitoneally (IP) for 5 days, then orally (0.12 mg/kg/day) for a total of 6 weeks. Cognitive function, brain structure by MRI and vascular architecture by microCT angiography were measured. C21 preserved cognitive function, specifically spatial memory, and improved vascular density in the ischemic hemisphere at 6 weeks, reflecting both arteriogenesis and angiogenesis. In conclusion, C21 prevented cognitive impairment after stroke, likely through a mechanism involving vascular protection and restoration.

Deferoxamine Treatment Prevents Post-Stroke Vasoregression and Neurovascular Unit Remodeling Leading to Improved Functional Outcomes in Type 2 Male Diabetic Rats: Role of Endothelial Ferroptosis

It is a clinically well-established fact that patients with diabetes have very poor stroke outcomes. Yet, the underlying mechanisms remain largely unknown. Our previous studies showed that male diabetic animals show greater hemorrhagic transformation (HT), profound loss of cerebral vasculature in the recovery period, and poor sensorimotor and cognitive outcomes after ischemic stroke. This study aimed to determine the impact of iron chelation with deferoxamine (DFX) on (1) cerebral vascularization patterns and (2) functional outcomes after stroke in control and diabetic rats. After 8 weeks of type 2 diabetes induced by a combination of high-fat diet and low-dose streptozotocin, male control and diabetic animals were subjected to thromboembolic middle cerebral artery occlusion (MCAO) and randomized to vehicle, DFX, or tPA/DFX and followed for 14 days with behavioral tests. Vascular indices (vascular volume and surface area), neurovascular remodeling (AQP4 polarity), and microglia activation were measured. Brain microvascular endothelial cells (BMVEC) from control and diabetic animals were evaluated for the impact of DFX on ferroptotic cell death. DFX treatment prevented vasoregression and microglia activation while improving AQP4 polarity as well as blood-brain barrier permeability by day 14 in diabetic rats. These pathological changes were associated with improvement of functional outcomes. In control rats, DFX did not have an effect. Iron increased markers of ferroptosis and lipid reactive oxygen species (ROS) to a greater extent in BMVECs from diabetic animals, and this was prevented by DFX. These results strongly suggest that (1) HT impacts post-stroke vascularization patterns and recovery responses in diabetes, (2) treatment of bleeding with iron chelation has differential effects on outcomes in comorbid disease conditions, and (3) iron chelation and possibly inhibition of ferroptosis may provide a novel disease-modifying therapeutic strategy in the prevention of post-stroke cognitive impairment in diabetes.

Thyroid hormone concentrations in severely or critically ill patients with COVID-19

OBJECTIVE

COVID-19 is a new coronavirus infectious disease. We aimed to study the characteristics of thyroid hormone levels in patients with COVID-19 and to explore whether thyroid hormone predicts all-cause mortality of severely or critically ill patients.

METHODS

The clinical data of 100 patients with COVID-19, who were admitted to Wuhan Tongji Hospital from February 8 to March 8, 2020, were analyzed in this retrospective study. The patients were followed up for 6-41 days. Patients were grouped into non-severe illness and severe or critical illness, which included survivors and non-survivors. Multivariate Cox proportional hazards analysis was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause mortality in association with continuous and the lower two quartiles of thyroid hormone concentrations in severely or critically ill patients.

RESULTS

The means of free T3 (FT3) were 4.40, 3.73 and 2.76 pmol/L in non-severely ill patients, survivors and non-survivors, respectively. The lower (versus upper) two quartiles of FT3 was associated with all-cause mortality HR (95% CI) of 9.23 (2.01, 42.28). The HR (95% CI) for all-cause mortality in association with continuous FT3 concentration was 0.41 (0.21, 0.81). In the multivariate-adjusted models, free T4 (FT4), TSH and FT3/FT4 were not significantly related to all-cause mortality. Patients with FT3 less than 3.10 pmol/L had increased all-cause mortality.

CONCLUSION

FT3 concentration was significantly lower in patients with severe COVID-19 than in non-severely ill patients. Reduced FT3 independently predicted all-cause mortality of patients with severe COVID-19.

System-on-chip upgrade of millimeter-wave imaging diagnostics for fusion plasma

Monolithic, millimeter wave "system-on-chip" technology has been employed in chip heterodyne radiometers in a newly developed Electron Cyclotron Emission Imaging (ECEI) system on the DIII-D tokamak for 2D electron temperature and fluctuation diagnostics. The system employs 20 horn-waveguide receiver modules each with customized W-band (75-110 GHz) monolithic microwave integrated circuit chips comprising a W-band low noise amplifier, a balanced mixer, a ×2 local oscillator (LO) frequency doubler, and two intermediate frequency amplifier stages in each module. Compared to previous quasi-optical ECEI arrays with Schottky mixer diodes mounted on planar antennas, the upgraded W-band array exhibits >30 dB additional gain and 20× improvement in noise temperature; an internal eight times multiplier chain is used to provide LO coupling, thereby eliminating the need for quasi-optical coupling. The horn-waveguide shielding housing avoids out-of-band noise interference on each module. The upgraded ECEI system plays an important role for absolute electron temperature and fluctuation measurements for edge and core region transport physics studies. An F-band receiver chip (up to 140 GHz) is under development for additional fusion facilities with a higher toroidal magnetic field. Visualization diagnostics provide multi-scale and multi-dimensional data in plasma profile evolution. A significant aspect of imaging measurement is focusing on artificial intelligence for science applications.

Delayed Administration of Angiotensin Receptor (AT2R) Agonist C21 Improves Survival and Preserves Sensorimotor Outcomes in Female Diabetic Rats Post-Stroke through Modulation of Microglial Activation

About 70% of stroke victims present with comorbid diseases such as diabetes and hypertension. The integration of comorbidities in pre-clinical experimental design is important in understanding the mechanisms involved in the development of stroke injury and recovery. We recently showed that administration of compound C21, an angiotensin II type 2 receptor agonist, at day 3 post-stroke improved sensorimotor outcomes by lowering neuroinflammation in diabetic male animals. In the current study, we hypothesized that a delayed administration of C21 would also lower chronic inflammation post-stroke in diabetic female animals. Young female diabetic rats were subjected to 1 h of middle cerebral artery occlusion (MCAO). Three days post-stroke, rats were administered C21 or vehicle in drinking water at a dose of 0.12 mg/kg/day for 4 weeks. The impact of C21 on microglial polarization was analyzed by flow cytometry in vivo and in vitro. Compound 21 treatment improved fine motor skills after MCAO through modulation of the microglia/macrophage inflammatory properties. In addition, C21 increased M2 polarization and reduced the M1:M2 ratio in vitro. In conclusion, delayed administration of C21 downregulates post-stroke inflammation in female diabetic animals. C21 may be a useful therapeutic option to lower neuro-inflammation and improve the post-stroke recovery in diabetes.

Behavioral and neurophysiological taste responses to sweet and salt are diminished in a model of subclinical intestinal inflammation

There is strong evidence for gut-taste bud interactions that influence taste function, behavior and feeding. However, the effect of gut inflammation on this axis is unknown despite reports of taste changes in gastrointestinal (GI) inflammatory conditions. Lipopolysaccharide (LPS), an inflammatory stimulus derived from gram-negative bacteria, is present in the normal GI tract and levels increase during high-fat feeding and gut infection and inflammation. Recordings from the chorda tympani nerve (CT), which transmits taste information from taste buds on the anterior tongue to the brain, previously revealed a transient decrease in sucrose responses in mice that ingest LPS during a single overnight period. Here we test the effect of acute or chronic, weekly LPS gavage on licking behavior and CT responses. Using brief-access testing, rats treated with acute LPS and mice receiving acute or chronic LPS decreased licking responses to sucrose and saccharin and to NaCl in mice. In long-term (23 h) tests chronic LPS also reduced licking responses to saccharin, sucrose, and NaCl in mice. Neurophysiological recordings from the CT supported behavioral changes, demonstrating reduced responses to sucrose, saccharin, acesulfame potassium, glucose and NaCl in acute and chronic LPS groups compared to controls. Chronic LPS significantly elevated neutrophils in the small intestine and colon, but LPS was not detected in serum and mice did not display sickness behavior or lose weight. These results indicate that sweet and salt taste sensitivity could be reduced even in asymptomatic or mild localized gut inflammatory conditions such as inflammatory bowel disease.

Diabetic rats are more susceptible to cognitive decline in a model of microemboli-mediated vascular contributions to cognitive impairment and dementia

Vascular disease plays an important role in all kinds of cognitive impairment and dementia. Diabetes increases the risk of vascular disease and dementia. However, it is not clear how existing vascular disease in the brain accelerates the development of small vessel disease and promotes cognitive dysfunction in diabetes. We used microemboli (ME) injection model in the current study to test the hypothesis that cerebrovascular dysfunction in diabetes facilitates entrapment of ME leading to inflammation and cognitive decline. We investigated cognitive function, axonal/white matter (WM) changes, neurovascular coupling, and microglial activation in control and diabetic male and female Wistar rats subjected to sham or low/high dose ME injection. Diabetic male animals had cognitive deficits, WM demyelination and greater microglial activation than the control animals even at baseline. Functional hyperemia gradually declined in diabetic male animals after ME injection. Both low and high ME injection worsened WM damage and increased microglial activation in diabetic male and female animals. Low ME did not cause cognitive decline in controls, while promoting learning/memory deficits in diabetic female rats and no further decline in diabetic male animals. High ME led to cognitive decline in control male rats and exacerbated the deficits in diabetic cohort. These results suggest that the existing cerebrovascular dysfunction in diabetes may facilitate ME-mediated demyelination leading to cognitive decline. It is important to integrate comorbidities/sex as a biological variable into experimental models for the development of preventive or therapeutic targets.

Neurovascular protection in voltage-gated proton channel Hv1 knock-out rats after ischemic stroke: interaction with Na+ /H+ exchanger-1 antagonism

Experimental studies have demonstrated protective effects of NHE‐1 inhibition on cardiac function; however, clinical trials utilizing NHE‐1 antagonists found an increase in overall mortality attributed to thromboembolic strokes. NADPH oxidase‐derived reactive oxygen species (ROS) from microglial cells have been shown to contribute to injury following stroke. We have recently demonstrated that NHE‐1 inhibition enhances ROS in macrophages in a Hv1‐dependent manner. As Hv1 protein is highly expressed in microglia, we hypothesized that “NHE‐1 inhibition may augment neurovascular injury by activating Hv1,” providing a potential mechanism for the deleterious effects of NHE‐1. The goal of this study was to determine whether neurovascular injury and functional outcomes after experimental stroke differed in wild‐type and Hv1 mutant Dahl salt‐sensitive rats treated with an NHE‐1 inhibitor. Stroke was induced using both transient and permanent of middle cerebral artery occlusion (MCAO). Animals received vehicle or NHE‐1 inhibitor KR32568 (2 mg/kg, iv) either 30 min after the start of MCAO or were pretreated (2 mg/kg, iv, day) for 3 days and then subjected to MCAO. Our data indicate that Hv1 deletion confers both neuronal and vascular protection after ischemia. In contrast to our hypothesis, inhibition of NHE‐1 provided further protection from ischemic stroke, and the beneficial effects of both pre‐ and post‐treatment with KR32568 were similar in wild‐type and Hv1^−/− rats. These data indicate that Hv1 activation is unlikely to be responsible for the increased incidence of cerebrovascular events observed in the heart disease patients after NHE‐1 inhibition treatment.

Adenosine kinase inhibition enhances microvascular dilator function and improves left ventricle diastolic dysfunction

OBJECTIVE

Inhibition of adenosine kinase (ADK), via augmenting endogenous adenosine levels exerts cardiovascular protection. We tested the hypothesis that ADK inhibition improves microvascular dilator and left ventricle (LV) contractile function under metabolic or hemodynamic stress.

METHODS AND RESULTS

In Obese diabetic Zucker fatty/spontaneously hypertensive heart failure F1 hybrid rats, treatment with the selective ADK inhibitor, ABT-702 (1.5 mg/kg, intraperitoneal injections for 8-week) restored acetylcholine-, sodium nitroprusside-, and adenosine-induced dilations in isolated coronary arterioles, an effect that was accompanied by normalized end-diastolic pressure (in mm Hg, Lean: 3.4 ± 0.6, Obese: 17.6 ± 4.2, Obese + ABT: 6.6 ± 1.4) and LV relaxation constant, Tau (in ms, Lean: 6.9 ± 1.5, Obese: 13.9 ± 1.7, Obese + ABT: 6.0 ± 1.1). Mice with vascular endothelium selective ADK deletion (ADK^VEC KO) exhibited an enhanced dilation to acetylcholine in isolated gracilis muscle (lgEC₅₀ WT: -8.2 ± 0.1, ADK^VEC KO: -8.8 ± 0.1, P < .05) and mesenteric arterioles (lgEC₅₀ WT: -7.4 ± 0.2, ADK^VEC KO: -8.1 ± 1.2, P < .05) when compared to wild-type (WT) mice, whereas relaxation of the femoral artery and aorta (lgEC₅₀ WT: -7.03 ± 0.6, ADK^VEC KO: -7.05 ± 0.8) was similar in the two groups. Wild-type mice progressively developed LV systolic and diastolic dysfunction when they underwent transverse aortic constriction surgery, whereas ADK^VEC -KO mice displayed a lesser degree in decline of LV function.

CONCLUSIONS

Our results indicate that ADK inhibition selectively enhances microvascular vasodilator function, whereby it improves LV perfusion and LV contractile function under metabolic and hemodynamic stress.

Development of an indirect ELISA based on glycoprotein B gene for detecting of Feline herpesvirus type 1

The study was aimed to develop an indirect enzyme-linked immunosorbent assay (ELISA), which can detect specifically Feline herpesvirus type 1 (FHV-1). The primers were designed based on the conserved sequence of FHV-1 glycoprotein B gene. The recombinant protein with reactogenicity was purified as coating antigen of the assay. The indirect ELISA, characterized by high sensitivity showed no cross-reaction with two types of feline virus, had detection limit at 1:2000 dilution. The positive rate of the assay, according to the determined cutoff value (0.25), was basically consistent with Feline Herpes Virus Antibody ELISA kit. In conclusion, the indirect ELISA with high repeatability and reproducibility can be used for detecting FHV-1, and can provide necessary support to related research.

Abstract WP155: Delayed Administration of Angiotensin Receptor (AT2-R) Agonist C21 Downregulates Diabetes Induced Pro-Inflammatory Microglia Activation Post-Stroke in Female Rats: Therapeutic Indications for Vascular Cognitive Impairment & Dementia

Post-stroke cognitive impairment (PSCI) occurs in up to 48% of patients, for which there is no therapy. Although 70% of stroke victims present with comorbid diseases such as diabetes and hypertension, the inadequate integration of these comorbidities into experimental studies limited our understanding of the mechanisms involved in the development of PSCI. Based on our recent findings that 1) the increased prevalence of PSCI in male diabetic animals is linked to heightened chronic inflammation and 2) even delayed administration of compound 21 (C21), an angiotensin II Type 2 receptor agonist, effectively reduces PSCI by lowering inflammation in male animals, we hypothesized that a delayed administration of C21 would also lower chronic inflammation post-stroke in female animals.

Methods: Diabetes was induced by a high fat diet (HFD) and low dose streptozotocin (STZ) combination. Rats were subjected to 1 h middle cerebral artery occlusion (MCAO) or sham surgery. 3 days post-stroke, rats were administered C21 or vehicle in drinking water at a dose of 0.12 mg/kg/day for 4 weeks. The direct effect of C21 on microglia polarization was determined in mouse cells (C8B4) and the mature:pro BDNF ratio was evaluated through western blot. Samples from freshly harvested brains (B-D slice containing the prefrontal cortex through the hippocampus), and from cell culture were analyzed by flow cytometry.

Results: Delayed administration of C21 starting 3 days post-stroke improved inflammation through modulation of the M1/M2 ratio. Cell culture results indicated that along with decreasing the M1/M2 ratio, it also increased the mature/pro-BDNF ratio.

Conclusion: Delayed administration of C21 downregulates post-stroke inflammation in both male and female diabetic animals. This study emphasizes the importance of translational disease modeling and suggests that C21 may be a useful therapeutic option to lower inflammation and prevent PSCI in comorbid diseases.

Abstract WP492: Differential Effects of Iron Chelation With Deferoxamine on Post-Stroke Neurovascular Inflammation: Disease and Sex Interactions

We have shown that 1) poor recovery in diabetes is associated with greater hemorrhagic transformation and significant loss of the cerebrovasculature, and 2) iron chelation therapy with deferoxamine (DFX) improves sensorimotor and cognitive outcomes while preventing vasoregression in male diabetic animals after stroke. This study tested the hypotheses that 1) diabetes mediates pathological post-stroke neovascularization in females and 2) DFX attenuates microglial activation and pathological neurovascular remodeling in both sexes. Control and diabetic animals were subjected to embolic middle cerebral artery occlusion (MCAO). DFX (100 mg/kg) or vehicle was given 1hour after MCAO and repeated every 12h for 7 days after stroke. Functional outcomes were assessed over time. Vascular indices, microglial morphology (activation), and neurovascular integrity (IgG and unpolarized Aquaporin-4) were measured at Day 14. Male and female microvascular endothelial cells (BMVECs) treated with iron and/or DFX were tested for viability and endothelial mesenchymal transition (EndMT) markers. DFX preserved vascular volume post-stroke in diabetic males. Stroke did not cause vasoregression in diabetic female animals; however, DFX reduced vascular indices while improving sensorimotor but not cognitive outcomes in both control and diabetic females. Ischemic injury amplified microglial activation and neurovascular remodeling in diabetes while DFX treatment restored these changes to control levels in male diabetic animals but not in females (Table). Female BMVECs grown under diabetic conditions expressed α-SMA and N-cadherin while VE-cadherin was decreased, indicative of EndMT (p<0.05 vs normal glucose). Data suggest that DFX treatment has sex- and disease-dependent effects on post-stroke neovascularization. Additional studies will aim to address the mechanisms by which DFX exerts these differential effects on functional outcomes and neurovascular remodeling.

Plasma fluoroacetic acid concentrations: Symptoms, hematological, and biochemical characteristics in patients with fluoroacetic acid poisoning in the emergency department

Fluoroacetic acid (FAcOH) was once a highly toxic rodenticide widely used in the world. In the past, studies on the toxicity of FAcOH have focused on animal experiments. The toxicity of FAcOH to humans and the changes of FAcOH in plasma have not been studied. Therefore, the present study aimed to describe the changes of plasma FAcOH concentrations, hematological, and biochemical characteristics in patients with FAcOH intoxication. According to clinical symptoms, 68 patients from the emergency department were divided into different groups: convulsion group, unconsciousness group, death group, and control groups. Plasma FAcOH concentrations, hematological, and biochemical parameters were investigated. Results demonstrated that patients in the convulsion group and the unconsciousness group had a significant increase (p < 0.01) in the level of neuron-specific enolase (NSE), creatine kinase MB (CKMB), glucose (GLU), and white blood cell count (WBC) and a significant decrease (p < 0.01) in serum potassium compared with the control group, respectively. Moreover, patients in the death group had a significant increase (p < 0.01) in the level of NSE, CKMB, N-terminal pro-brain natriuretic peptide, GLU, and WBC and a significant decrease (p < 0.01) in serum potassium and total calcium compared with the survival group. The concentrations of FAcOH in plasma in the convulsion group, the unconsciousness group, and the death group were 72.31 ± 42.29, 118.33 ± 55.41, and 163.78 ± 43.32 μg/mL, respectively. These changes and the plasma FAcOH concentrations may increase our understanding of the toxicity of FAcOH to humans and may help doctors to judge the clinical prognosis of patients with FAcOH intoxication.

Delayed Administration of Angiotensin II Type 2 Receptor (AT2R) Agonist Compound 21 Prevents the Development of Post-stroke Cognitive Impairment in Diabetes Through the Modulation of Microglia Polarization

A disabling consequence of stroke is cognitive impairment, occurring in 12%-48% of patients, for which there is no therapy. A critical barrier is the lack of understanding of how post-stroke cognitive impairment (PSCI) develops. While 70% of stroke victims present with comorbid diseases such as diabetes and hypertension, the limited use of comorbid disease models in preclinical research further contributes to this lack of progress. To this end, we used a translational model of diabetes to study the development of PSCI. In addition, we evaluated the application of compound 21 (C21), an angiotensin II Type 2 receptor agonist, for the treatment of PSCI by blinding the treatment assignment, setting strict inclusion criteria, and implementing a delayed administration time point. Diabetes was induced by a high-fat diet (HFD) and low-dose streptozotocin (STZ) combination. Control and diabetic rats were subjected to 1 h middle cerebral artery occlusion (MCAO) or sham surgery. Adhesive removal task (ART) and two-trial Y-maze were utilized to test sensorimotor and cognitive function. Three days post-stroke, rats that met the inclusion criteria were administered C21 or vehicle in drinking water at a dose of 0.12 mg/kg/day for 8 weeks. Samples from freshly harvested brains were analyzed by flow cytometry and immunohistochemistry (IHC). Diabetes exacerbated the development of PSCI and increased inflammation and demyelination. Delayed administration of C21 3 days post-stroke reduced mortality and improved sensorimotor and cognitive deficits. It also reduced inflammation and demyelination through modulation of the M1:M2 ratio in the diabetic animals.

Diabetic Stroke Promotes a Sexually Dimorphic Expansion of T Cells

We recently reported that diabetes negates the cerebrovascular protection typically seen in adult female rats resulting in cognitive impairment, which is worsened by increased parenchymal bleeding and edema after ischemic stroke. Although women experience more severe diabetes and suffer from a higher rate of diabetic complications, including stroke and cognitive impairment, underlying mechanisms contributing to sex differences are limited. Emerging evidence suggests interleukin (IL)-17 contributes to cerebrovascular pathologies: (1) high salt diet-mediated expansion of IL-17-producing T cells (Th17) in the gut microbiome promotes cerebrovascular dysfunction and cognitive impairment in male mice, (2) increased IL-17-producing γδTCR cells exacerbates stroke injury in male mice, and (3) IL-17 promotes rupture of cerebral aneurysms in female mice. Based on these premises, we investigated the potential involvement of IL-17-producing inflammatory cells in cerebrovascular dysfunction and post-stroke vascular injury in diabetes by measuring intestinal, circulating, or cerebral T cell profiles as well as in plasma IL-17 in both sexes. Cell suspensions prepared from naive or stroked (3 days after stroke) diabetic and control rats were analyzed by flow cytometry, and IL-17 levels were measured in plasma using ELISA. Diabetes deferentially promoted the expansion of cerebral Th17 cells in females. In response to stroke, diabetes had a sexually dimorphic effect on the expansion of numerous T cell profiles. These results suggest that a better understanding of the role of IL-17-producing cells in diabetes may identify potential avenues in which the molecular mechanisms contributing to these sex differences can be further elucidated.

NLRP3 inflammasome inhibition with MCC950 improves diabetes-mediated cognitive impairment and vasoneuronal remodeling after ischemia

Diabetes increases the risk and worsens the progression of cognitive impairment via the greater occurrence of small vessel disease and stroke. Yet, the underlying mechanisms are not fully understood. It is now accepted that cardiovascular health is critical for brain health and any neurorestorative approaches to prevent/delay cognitive deficits should target the conceptual neurovascular unit (NVU) rather than neurons alone. We have recently shown that there is augmented hippocampal NVU remodeling after a remote ischemic injury in diabetes. NLRP3 inflammasome signaling has been implicated in the development of diabetes and neurodegenerative diseases, but little is known about the impact of NLRP3 activation on functional and structural interaction within the NVU of hippocampus, a critical part of the brain that is involved in forming, organizing, and storing memories. Endothelial cells are at the center of the NVU and produce trophic factors such as brain derived neurotrophic factor (BDNF) contributing to neuronal survival, known as vasotrophic coupling. Therefore, the aims of this study focused on two hypotheses: 1) diabetes negatively impacts hippocampal NVU remodeling and worsens cognitive outcome after stroke, and 2) NLRP3 inhibition with MCC950 will improve NVU remodeling and cognitive outcome following stroke via vasotrophic (un)coupling between endothelial cells and hippocampal neurons. Stroke was induced through a 90-min transient middle cerebral artery occlusion (MCAO) in control and high-fat diet/streptozotocin-induced (HFD/STZ) diabetic male Wistar rats. Saline or MCC950 (3 mg/kg), an inhibitor of NLRP3, was injected at 1 and 3 h after reperfusion. Cognition was assessed over time and neuronal density, blood-brain barrier (BBB) permeability as well as NVU remodeling (aquaporin-4 [AQP4] polarity) was measured on day 14 after stroke. BDNF was measured in endothelial and hippocampal neuronal cultures under hypoxic and diabetes-mimicking condition with and without NLRP3 inhibition. Diabetes increased neuronal degeneration and BBB permeability, disrupted AQP4 polarity, impaired cognitive function and amplified NLRP3 activation after ischemia. Inhibition with MCC950 improved cognitive function and vascular integrity after stroke in diabetic animals and prevented hypoxia-mediated decrease in BDNF secretion. These results are the first to provide essential data showing MCC950 has the potential to become a therapeutic to prevent neurovascular remodeling and worsened cognitive decline in diabetic patients following stroke.

Inhibition of Toll-Like Receptor-4 (TLR-4) Improves Neurobehavioral Outcomes After Acute Ischemic Stroke in Diabetic Rats: Possible Role of Vascular Endothelial TLR-4

Diabetes increases the risk of occurrence and poor functional recovery after ischemic stroke injury. Previously, we have demonstrated greater hemorrhagic transformation (HT), edema, and more severe functional deficits after stroke in diabetic animals that also presented with cerebral vasoregression and endothelial cell death in the recovery period. Given that Toll-like receptor 4 (TLR-4) activation in microvascular endothelial cells triggers a robust inflammatory response, we hypothesized that inhibition of TLR-4 signaling prevents endothelial cell death and improves outcomes after stroke. Animals were treated with vehicle or TLR-4 inhibitor TAK242 (3 mg/kg; i.p.) following middle cerebral artery occlusion (MCAO). Neurobehavioral deficits were measured at baseline and day 3 after ischemic stroke. Primary brain microvascular endothelial cells (BMVECs) from diabetic animals were subjected to oxygen glucose deprivation re-oxygenation (OGDR) and treated with 0.1 mM iron(III)sulfate hydrate (iron) (to mimic the post-stroke bleeding) and TLR-4 inhibitors. Ischemic stroke increased the expression of TLR-4 in both hemispheres and in the microvasculature of diabetic animals. Cerebral infarct, edema, HT, and functional deficits were greater in diabetic compared to control animals. Inhibition of TLR-4 significantly reduced the neurovascular injury and improved functional outcomes. OGDR and iron reduced the cell viability and increased the expression of TLR-4 associated proteins (RIP3, MyD88, phospho-NF-kB, and release of IL-6) in BMVECs from diabetic animals. In conclusion, TLR-4 is highly upregulated in the microvasculature and that beneficial effects of TLR-4 inhibition are more profound in diabetes. This suggests that inhibition of vascular TLR-4 may provide therapeutic benefits for stroke recovery in diabetes.

Abstract TP565: Delayed Administration of Angiotensin Receptor (AT2R) Agonist C21 Downregulates Diabetes Induced Pro-Inflammatory Microglia Activation to Improve Cognitive and Functional Recovery Post-Stroke

A disabling consequence of stroke is cognitive impairment, occurring in 12%-48% of patients, for which there is NO therapy. A critical barrier is the lack of understanding of how vascular cognitive impairment & dementia (VCID) develops. While 70% of stroke victims present with comorbid diseases such as diabetes & hypertension, the limited use of comorbid disease models in preclinical research further contributes to this lack of progress. We hypothesized that diabetes exacerbates the development of VCID through chronic activation of a pro-inflammatory M1-like microglia, & that this can be therapeutically targeted with Angiotensin Receptor (AT2R) Agonist C21.

Methods: Diabetes was induced in male Wistar rats by a high-fat diet & low dose streptozotocin combination. At 12-14 weeks of age a total of 69 control & diabetic rats were subjected to 1 hr middle cerebral artery occlusion (MCAO) or Sham surgery. Adhesive removal task & 2-trial Ymaze were utilized to test sensorimotor & cognitive function. 3 days post-MCAO, rats that met the inclusion criteria were administered C21 or saline in drinking water at a dose of 0.12 mg/kg/day. Cell suspensions from freshly harvested brains were analyzed by flow cytometry utilizing antibodies against cell surface markers for residential M1 microglia (CD45, TMEM119, CD206) & intracellular markers (TNFα and IL-10).

Results: Untreated control rats progressively recovered from stroke-induced functional deficits by week 4, while untreated diabetics did not. 2 weeks post-MCAO both untreated control & diabetic rats exhibited a significant decline in sensorimotor (P < 0.01 control, 0.05 diabetic) and cognitive function (P < 0.05 control, 0.01 diabetic) compared to Shams. C21 treatment halted the decline and improved sensorimotor (P < 0.05 controls, 0.05 diabetics) and cognitive function (P < 0.05 controls, 0.05 diabetics). Flow cytometry analyses indicate that C21 treatment reduced M1-like activation in the ipsilateral prefrontal cortex & the contralateral hippocampus of diabetic rats (P < 0.05, 0.05). No differences within the control groups were observed.

Conclusion: Delayed administration of C21 halts the progressive decline of functional & cognitive deficits & downregulates chronic M1-like activation in diabetic stroke.

Abstract TP564: Diabetic but Not Control Rats Develop White Matter Injury and Cognitive Deficits in a Microemboli Injection Model of VCID

Diabetes doubles the risk of vascular cognitive impairment and dementia (VCID), a disease is associated with small vessel disease (SVD) of the brain. Given that diabetes mediates early cerebrovascular dysfunction, and microemboli are common in the cerebral circulation and can penetrate into the brain parenchymal arterioles without causing an infarction, we tested the hypothesis that entrapment of microemboli in dysfunctional vessel walls accelerates the development of SVD ultimately resulting in VCID in diabetes. Diabetes was induced by a high fat diet and low dose streptozotocin (35 mg/kg, IP) injection in male Wistar rats. Cholesterol crystal microemboli [40-70 μm, 3000 (Group A) or 6000 (Group B) per 200 μl saline] were injected 8 weeks later through internal carotid artery. Cognitive function was monitored by the novel object recognition (NOR) test. White matter injury was assessed by Luxol fast blue (LFB) and hematoxylin/eosin (HE) staining in Group A. Cerebral blood flow (CBF), white matter hyperintensities (T2 map), microbleeds (T2 asterisk), and microinfarcts (T2 W) were assessed by MRI in Group B. In Group A, there was increased white matter degeneration in diabetic animals compared to controls. This degeneration was aggravated by microembolic injection. We found that cognitive function was exacerbated in Group B diabetes animals. MRI results showed these animals also had decreased CBF but no change on microinfarcts or microbleed. These results suggest that white matter degeneration starts in the early stages of diabetes, and that microemboli exacerbate these pathological changes even before the appearance of any neurobehavioral deficits. Additional studies are needed to examine the precise time course for development of cerebral neurovascular changes relative to appearance of behavioral deficits and explore potential therapeutic targets for VCI in diabetes.

Abstract 106: NLRP3 Inflammasome Inhibition With MCC950 Improves Diabetes-Mediated Cognitive Impairment and Vasoneuronal Remodeling After Ischemia

Diabetes increases the risk and worsens the progression of cognitive impairment via the greater occurrence of small vessel disease and stroke. While NLRP3 inflammasome signaling has been implicated in the development of neurodegenerative diseases, little is known about the impact of NLRP3 activation on functional and structural interaction within the neurovascular unit (NVU) in diabetes. Endothelial cells are at the center of NVU and produce trophic factors such as BDNF contributing to neuronal survival, known as vasotrophic coupling. Therefore, the goals of this study were to determine the role of NLRP3 activation: 1) on hippocampal NVU remodeling and cognitive outcome after stroke in diabetes, and 2) on vasotrophic uncoupling between endothelial cells and hippocampal neurons after hypoxic injury in diabetes-mimicking conditions. Control and high-fat diet/STZ induced diabetic male rats were treated with saline or MCC950 (3mg/kg), a small molecule inhibitor of NLRP3, after reperfusion following a 90-min MCAO. Cognition was assessed. Neuronal death, blood-brain barrier (BBB) permeability and glial remodeling was measured on Day 14 after stroke. BDNF was measured in endothelial and hippocampal cell cultures under hypoxic and diabetes-mimicking condition with and without NLRP3 inhibition. Diabetes increased neuronal degeneration, BBB permeability, disrupted AQP4 polarity, impaired cognitive function and increased NLRP3 activation after ischemia. Inhibition with MCC950 improved cognitive function and NVU indices after stroke in diabetic animals and prevented hypoxia-mediated decrease in BDNF secretion. These results are the first to provide essential data showing MCC950 has the potential to become a therapeutic to prevent neurovascular remodeling and worsened cognitive decline in diabetic patients following stroke.

Abstract WP152: Iron Chelation Improves Stroke Outcomes in Diabetes: Impact on Neurovascular Remodeling, Microglial Activation and Ferroptotic Endothelial Cell Death

Introduction: We have shown that 1) poor recovery in diabetes is associated with greater hemorrhagic transformation (HT) and significant loss the cerebrovasculature, and 2) iron chelation therapy with deferoxamine (DFX) improves functional outcomes while preventing vasoregression in diabetic animals after embolic stroke. However, underlying mechanisms remained unknown. Current study was designed to test the hypotheses that DFX attenuates 1) microglial activation and pathological neurovascular remodeling, and 2) ferroptosis, iron-dependent cell death, of brain microvascular endothelial cells (BMVECs).

Methods: Control and type 2 diabetic animals were subjected to embolic middle cerebral artery occlusion (MCAO). DFX (100 mg/kg) or vehicle was given 1hour after MCAO and repeated every 12 h for 7 days after stroke. At Day 14, microglial activation and neurovascular integrity were evaluated by immunohistochemical analyses of Iba1 and Aquaporin-4 (AQP4) polarity, respectively. BMVECs isolated from control Wistar and diabetic Goto-Kakizaki rats were treated with iron(III)sulfate (0.1mM) in presence/absence of DFX (100μM) for 6 hours. Cell viability and ferroptotic cell death markers like IREB2, ACSL4, MDA formation and total glutathione content were measured.

Results: Ischemia/reperfusion injury amplified microglial activation and neurovascular remodeling in diabetes while DFX treatment reduced these changes to control levels (Table 1). DFX treatment also prevented iron-mediated cell death and decreased the expression of ferroptotic cell death markers (Table 1).

Conclusions: Mechanisms underlying DFX-mediated improvement of sensorimotor and cognitive functions after stroke in diabetes involve attenuation of neuroinflammation, pathological neurovascular remodeling and endothelial ferroptosis. Iron chelation is a potential therapeutic strategy to improve outcomes in diabetic stroke that is associated with greater HT.

Abstract WP151: Ischemic Injury in Diabetes Augments Cerebral Microvascular Matrix Metalloproteinase Activation in Female Rats

Introduction: Diabetic female patients are at greater risk of stroke and worsened recovery. We have previously shown that matrix metalloprotease 3 (MMP3) exacerbates hemorrhagic transformation (HT) in hyperglycemic stroke in male rats while high glucose and hypoxia increases MMP3 activity in brain microvascular endothelial cells (BMVECs). Furthermore, diabetic female rats develop greater HT. Current study was designed to test the hypothesis that ischemic stroke increases the cerebral microvascular MMP3 activity in diabetic female animals.

Methods: Female rats after 7-8 weeks of diabetes (high fat diet and low dose of streptozotocin) were subjected to 60 min MCAO. After 3 days, adhesive removal time (ART) and behavioral composite score were measured and cerebral microvessels were isolated. Human female BMVECs were grown under normal (5.5mM glucose) or diabetic condition (25mM glucose plus 100μM sodium palmitate) for 48 hours, followed by hypoxia insult for 12 hours (200μM cobalt chloride). Cell lysate, media and microvascular homogenates were analyzed for MMP profiling by immunoblotting, zymography and MMP3 enzyme activity by fluorescence resonance energy transfer (FRET) assay.

Results: MMP3 protein expression and activity were significantly increased in the ischemic microvasculature and this was accompanied by a worse neurobehavioral score (Table 1). In vitro, expression of MMP3, 2 and 9 proteins in cell lysate were not different between the groups. However, MMP3 and MMP9 enzyme activities were significantly increased in the diabetes condition while, there was no additional increase in enzyme activity with hypoxia. MMP2 activity was significantly increased with hypoxia in diabetes condition (Table 1).

Conclusions: In female rats, diabetes and hypoxia increase MMP activity in the microvasculature and endothelial cells. These observations provide initial evidence to further explore the role of MMPs in the increased HT seen in females with diabetes.

Abstract WP137: Angiotensin Type 2 Receptor Stimulation With Compound 21 Prevents Delayed Cognitive Impairment in Hypertensive, Ovariectomized Female Rats After Ischemic Stroke: A Randomized, Blinded, Preclinical Study

Introduction: The angiotensin type 2 receptor (AT2R) agonist, compound 21 (C21), has been shown to be neuroprotective and neurorestorative after stroke in male rats. Here, we aim to determine the long-term impact of C21 treatment on hypertensive female rats after stroke.

Methods: Twenty female ovariectomized spontaneously hypertensive rats (SHRs), 16 weeks of age, were subjected to 1h MCAO and randomized at 24h to receive either vehicle or IP C21 0.03 mg/kg for 5 days followed by oral C21 (0.12mg/kg/day) for 5 weeks in drinking water. Sensorimotor behavior tests (modified Bederson, 0-8, where 8 is normal) were performed at 24h and weekly, while cognitive assessments (Passive Avoidance and Novel Object Recognition) were performed at weeks 5 and 6.

Results: (mean±SEM) All stroked animals survived and showed improved motor performance at 6 weeks, with no effect of C21. However, C21 treatment significantly improved non-spatial working memory and reference memory without an effect on anxiety level at 6 weeks post-stroke.

Conclusions: AT2R stimulation using C21 improves sensorimotor function and prevents the development of cognitive impairment in ovariectomized female rats, even when initiated at 24 hours after stroke.

Genetic analysis of skinfold thickness and its association with body condition score and milk production traits in Chinese Holstein population

The skin has many important roles in dairy cattle, and skinfold thickness could be used as an indicator of body fat deposition. The objectives of this study were to estimate genetic parameters of skinfold thickness and to explore its association with body condition score (BCS) and milk production traits in a Chinese Holstein population. Skinfold thicknesses over the neck (STN) and the last rib (STR), BCS, and test-day records of milk production traits were available for 6,416 lactating Holstein cows in the summers of 2015 and 2016 in Beijing, China. Multi-trait animal models were used to estimate variance and covariance components using the DMU software. The average STN was 7.15 ± 1.28 mm, and the average STR was 11.76 ± 1.95 mm (mean ± standard deviation). Estimated heritability was 0.13 ± 0.03 for STN and 0.26 ± 0.04 for STR. We detected a high genetic correlation (0.79 ± 0.08; heritability ± standard error) between STN and STR. Genetic correlations between skinfold thickness and BCS were low to moderate: 0.18 between STR and BCS, and 0.33 between STN and BCS. Genetic correlations between skinfold thickness and milk yield, milk fat percentage, and milk protein percentage were negligible, ranging from -0.02 to 0.15. Collectively, skinfold thickness is characterized as a trait with moderate heritability. Skinfold thickness is sensitive to changes in body condition or fat deposition across parities and lactation stages in milking cows, and we confirmed the complementary nature of skinfold thickness and BCS genetically as well as phenotypically by comparing their changing trends throughout lactation and across lactations. The use of skinfold thickness, together with BCS, can assist in the monitoring of changes in body fat deposition to achieve higher management precision.

Poststroke cognitive impairment and hippocampal neurovascular remodeling: the impact of diabetes and sex

Diabetes increases the risk and severity of cognitive impairment, especially after ischemic stroke. Pathological remodeling of the cerebrovasculature has been postulated to contribute to poor neuronal repair and worsened cognitive deficits in diabetes. However, little is known about the effect of diabetes on the vascularization of hippocampus, a domain critical to memory and learning. Therefore, we had two aims for this study: 1) to determine the impact of diabetes on hippocampal neurovascular remodeling and the resulting cognitive impairment after stroke using two models with varying disease severity, and 2) to compare the effects of ischemia on hippocampal neurovascular injury in diabetic male and female animals. Stroke was induced by middle cerebral artery occlusion (MCAO) by either the suture or embolic method in control and diabetic age-matched male and female Wistar rats. Hippocampal neuronal density, vascular architecture, and microglial activation as well as cognitive outcomes were measured. Embolic MCAO induced greater neuronal degeneration, pathological vascularization, microglial activation, and cognitive impairment in diabetes as compared with control animals or 60-min MCAO. Although diabetic males had lower neuronal density at baseline, diabetic females had more neurodegeneration after stroke. Control animals recovered cognitive function by day 14 after stroke; diabetic animals showed deficits regardless of sex. These results suggest that mechanisms underlying cognitive decline in diabetes may differ in males and females and provide further insight to the impact of diabetes on stroke severity and poststroke cognitive impairment. NEW & NOTEWORTHY The present study is the first to provide comparative information on the effects of diabetes and ischemia on cognitive outcomes in both sexes while also evaluating the neurovascular structure in the hippocampus, a critical region for cognitive and memory-related tasks.

Post-stroke neovascularization and functional outcomes differ in diabetes depending on severity of injury and sex: Potential link to hemorrhagic transformation

Diabetes is associated with increased risk and worsened outcome of stroke. Previous studies showed that male diabetic animals had greater hemorrhagic transformation (HT), profound loss of cerebral vasculature, and poor behavioral outcomes after ischemic stroke induced by suture or embolic middle cerebral artery occlusion (MCAO). Females are protected from stroke until reaching the menopause age, but young females with diabetes have a higher risk of stroke and women account for the majority of stroke mortality. The current study postulated that diabetes is associated with greater vascular injury and exacerbated sensorimotor and cognitive outcome after stroke even in young female animals. Male and female control and diabetic animals were subjected to transient MCAO and followed for 3 or 14 days to assess the neurovascular injury and repair. The vascularization indices after stroke were lower in male diabetic animals with 90-min but not 60-min ischemia/reperfusion injury, while there was no change in female groups. Cognitive deficits were exacerbated in both male and female groups regardless of the injury period, while the sensorimotor dysfunction was worsened in male diabetic animals with longer ischemia time. These results suggest that diabetes negates the protection afforded by sex in young female animals, and post-stroke vascularization pattern is influenced by the degree of injury and correlates with functional outcome in both sexes. Vasculoprotection after acute ischemic stroke may provide a novel therapeutic strategy in diabetes.

Experimental study on the evolution of Peregrine breather with uniform-depth adverse currents

A series of laboratory experiments were performed to study the evolution of Peregrine breather (PB) in a wave flume in finite depth, and wave trains were initially generated in a region of quiescent water and then propagated into an adverse current region for which the current velocity strength gradually increased from zero to an approximately stable value. The PB is often considered as a prototype of oceanic freak waves that can focus wave energy into a single wave packet. In the experiment, the cases were selected with the relative water depths k_{0}h (k_{0} is the wave number in quiescent water and h is the water depth) varying from 3.11 through 8.17, and the initial wave steepness k_{0}a_{0} (a_{0} is the background wave amplitude) ranges between 0.065 and 0.120. The experimental results show the persistence of the breather evolution dynamics even in the presence of strong opposing currents. We have shown that the characteristic spectrum of the PB persists even on strong currents, thus making it a viable characteristic for prediction of freak waves. It was also found that the adverse currents tend to shift the focusing point upstream compared to the cases without currents. Furthermore, it was found that uniform-depth adverse currents can reduce the breather extension in time domain.

Abstract TP112: Differential Effects of Deferoxamine Treatment on Neurological Deficits in Young Diabetic Female Animals After Embolic Stroke

Premenopausal women have lower stroke risk and mortality than age-matched men, a finding replicated in preclinical models. However, we recently reported that female diabetic rats developed greater hemorrhagic transformation (HT) after embolic stroke and thrombolysis with tPA, leading to poor short term outcomes, despite no change in infarct size. Given that iron chelation therapy with deferoxamine (DFX) in the recovery period improves long term functional outcome in male diabetic rats that develop HT after embolic stroke, the current study tested the hypothesis that DFX will improve neurological recovery in diabetic females, especially with tPA combined treatment. Control and type 2 diabetic female animals were subjected to embolic middle cerebral artery occlusion. DFX (100 mg/kg) or vehicle was given every 12 h for 7 days after stroke. tPA (1 mg/kg) was given at 90 min post-occlusion to diabetes group. The composite score (Bederson’s score and beam walk), adhesive removal (ART) and novel object recognition (NOR) were assessed at day 3, 7 and 14 after the surgery. DFX improved sensorimotor deficits in both groups, and the combination with tPA in the diabetes group had a similar effect to DFX alone. Control vehicle group regained cognitive function but there was no change in diabetic animals which had deficits at baseline. Interestingly, cognitive deficits increased in the control DFX and diabetes tPA+DFX group. These results suggest that DFX treatment may improve the long term sensorimotor deficits in diabetic females after stroke but the impact on cognitive outcomes needs further evaluation.

Abstract WP109: Deferoxamine Improves Vascular Repair and Cognitive Outcomes After Embolic Stroke In Diabetic but Not Control Animals: Interaction With tPA

Diabetes increases the risk of hemorrhagic transformation (HT) in ischemic stroke, especially with the use of tissue plasminogen activator (tPA). We showed that iron chelation therapy with deferoxamine (DFX) improves functional outcome in male diabetic animals after embolic stroke but its interaction with tPA remained unknown. We also reported that increased HT is associated with loss of cerebrovasculature in the recovery period in diabetic animals. This study tested the hypotheses that DFX treatment initiated after stroke 1) will improve neurological recovery after embolic stroke with tPA, and 2) will prevent cerebrovascular regression in diabetes. Control and type 2 diabetic animals were subjected to embolic middle cerebral artery occlusion. tPA (1 mg/kg) was given at 90 min post-occlusion. DFX (100 mg/kg) or vehicle was given every 12 h for 7 days after stroke. The composite score (Bederson’s score and beam walk), adhesive removal (ART) and novel object recognition (NOR) were assessed at day 3, 7 and 14 after the surgery. Cerebrovascularization indices in the ipsilateral cortex (vascular volume, surface area, and branch density) were measured with 3D imaging. DFX improved sensorimotor deficits in both groups and this effect was more robust in tPA combination. While DFX lowered vascularization indices in control animals, it prevented vasoregression in diabetes. Interestingly, DFX prevented the recovery of cognitive function in controls while improving it in diabetic animals. These results suggest that treatment with DFX may improve long term recovery in diabetes.

Abstract TMP32: Ischemic Stroke Causes Vascular Regression in Type-II Diabetic Male Rats: Potential Role of Regulated Cell Death Mechanisms

Diabetes not only increases the risk of stroke, it also worsens recovery after stroke. We previously showed that ischemic stroke causes cerebral vasoregression that is associated with poor outcomes in a lean model of diabetes. Current experiments were designed to 1) study the effect of ischemic stroke on cerebral vasculature in male and female rats using a diet-induced model of diabetes, and 2) identify mechanisms involved in vascular regression.

Methods: Diabetes was induced in male and female Wistar rats using high fat diet and low dose of streptozotocin. After 8 weeks of diabetes animals were subjected to embolic stroke or sham surgeries. After 14 days of stroke, vascular indices (vascular volume, surface area and branch density) were measured in cortex and striatum of both hemispheres using confocal images of FITC filled brain sections. Regulated cell death markers (necroptosis and ferroptosis) were tested in brain sections by immunohistochemistry.

Results: In male animals, diabetes alone promoted pathological vascularization. There was an interaction such that stroke increased vascular volume and branch density in control rats while decreasing it in diabetes in both ipsilateral and contralateral side. However, in females, diabetes did not impact vascularization with the exception that branch density was decreased in ipsilateral cortex. Cell death markers of necroptosis (TLR-4) and ferroptosis (IREB2, citrate synthase) were upregulated in male diabetic animals.

Conclusions: Ischemic stroke impairs cerebral vasculature in diabetic male animals and it was associated with upregulation of newly described regulated cell death pathways.

The function of dendritic cells in modulating the host response

Dendritic cells (DCs) are antigen-presenting cells that capture, process, and present antigens to lymphocytes to initiate and regulate the adaptive immune response. DCs detect bacteria in skin and mucosa and migrate into regional lymph nodes, where they stimulate antigen-specific T and B lymphocyte activation and proliferation. DCs direct CD4 T cells to differentiate to T-cell subsets such as T helper cells types 1, 2, and 17, and regulatory T cells. The periodontium is chronically exposed to oral bacteria that stimulate an inflammatory response to induce gingivitis or periodontitis. DCs play both protective and destructive roles through activation of the acquired immune response and are also reported to be a source of osteoclast precursors that promote bone resorption. FOXO1, a member of the forkhead box O family of transcription factors, plays a significant role in the activation of DCs. The function of DCs in periodontal inflammation has been investigated in a mouse model by lineage-specific deletion of FOXO1 in these cells. Deletion of FOXO1 reduces DC protective function and enhances susceptibility to periodontitis. The kinase Akt, phosphorylates FOXO1 to inhibit FOXO activity. Hence the Akt-FOXO1 axis may play a key role in regulating DCs to have a significant impact on periodontal disease.

Linear-shear-current modified Schrödinger equation for gravity waves in finite water depth

A nonlinear Schrödinger equation for the propagation of two-dimensional surface gravity waves on linear shear currents in finite water depth is derived. In the derivation, linear shear currents are assumed to be a linear combination of depth-uniform currents and constant vorticity. Therefore, the equation includes the combined effects of depth-uniform currents and constant vorticity. Next, using the equation, the properties of the modulational instability of gravity waves on linear shear currents are investigated. It is showed that shear currents significantly modify the modulational instability properties of weakly nonlinear waves. Furthermore, the influence of linear shear currents on Peregrine breather which can be seen as a prototype of freak waves is also studied. It is demonstrated that depth-uniform opposing currents can reduce the breather extension in both the time and spatial domain in intermediate water depth, but following currents has the adverse impact, indicating that a wave packets with freak waves formed on following currents contain more hazardous waves in finite water depth. However, the corresponding and coexisting vorticity can counteract the influence of currents. Additionally, if the water depth is deep enough, shear currents have negligible effect on the characteristics of Peregrine breathers.

Thymidylate synthase gene polymorphisms as important contributors affecting hepatocellular carcinoma prognosis

BACKGROUND

Thymidylate synthase (TYMS), a key rate-limiting enzyme in the folate metabolism, plays essential roles in the development of several malignancies including hepatocellular carcinoma (HCC). Nonetheless, the association of the single nucleotide polymorphisms (SNPs) in TYMS gene with the prognosis of Chinese HCC patients remains unknown.

METHODS

A total of 492 HCC patients who underwent surgery treatment were included in this study. Five functional SNPs (rs2847153, rs2853533, rs502396, rs523230, and rs9967368) in TYMS gene were genotyped using the iPLEX genotyping system. Multivariate Cox proportional hazards regression model and Kaplan-Meier curve were used to analyze the association of SNPs with survival and recurrence of HCC patients.

RESULTS

Two SNPs (rs523230 and rs9967368) in TYMS gene were significantly associated with the overall survival of HCC patients. Patients carrying homozygous variant genotype (VV) of rs523230 had significantly decreased risk of death (hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.46-1.00; P=0.048) when compared with those carrying homozygous wild-type (WW) or heterozygous (WV) genotypes, while patients carrying WV+VV genotype of rs9967368 had significantly increased risk of death (HR, 1.46; 95% CI, 1.05-2.04; P=0.026) when compared with those carrying WW genotypes. Cumulative effect analysis showed a significant dose-dependent effect of unfavorable SNPs on OS.

CONCLUSIONS

Our study for the first time demonstrates the association of SNPs in TYMS gene and clinical outcome of HCC, suggesting that rs523230 and rs9967368 in TYMS gene might be used to predict clinical outcome of Chinese HCC patients.

Diabetes Worsens Functional Outcomes in Young Female Rats: Comparison of Stroke Models, Tissue Plasminogen Activator Effects, and Sexes

Diabetes worsens stroke outcome and increases the risk of hemorrhagic transformation (HT) after ischemic stroke, especially with tissue plasminogen activator (tPA) treatment. The widespread use of tPA is still limited by the fear of hemorrhagic transformation (HT), and underlying mechanisms are actively being pursued in preclinical studies. However, experimental models use a 10 times higher dose of tPA than the clinical dose (10 mg/kg) and mostly employ only male animals. In this translational study, we hypothesized that low-dose tPA will improve the functional recovery after the embolic stroke in both control and diabetic male and female animals. Diabetes was induced in age-matched male and female Wistar rats with high fat diet and low-dose streptozotocin (30 mg/kg, i.p.). Embolic stroke was induced with clot occlusion of the middle cerebral artery (MCA). The animals were treated with or without tPA (1 mg/kg, i.v.) at 90 min after surgery. An additional set of animals were subjected to 90 min MCAO with suture. Neurological deficits (composite score and adhesive removal test-ART), infarct size, edema ratio, and HT index were assessed 3 days after surgery. In the control groups, female rats had smaller infarcts and better functional outcomes. tPA decreased infarct size in both sexes with a greater effect in males. While there was no difference in HT between males and females without tPA, HT was less in the female + tPA group. In the diabetic groups, neuronal injury increased in females reaching that of the infarct sizes seen in male rats. tPA decreased infarct size in females but not males. HT was greater in female rats than in males and was not further increased with tPA. Diabetes worsened neurological deficits in both sexes. Male animals showed improved sensorimotor skills, especially with tPA treatment, but there was no improvement in females. These data suggest that diabetes amplifies neurovascular injury and neurological deficits in both sexes. Human dose tPA offers some degree of protection in male but not female rats. Given that control female animals experience less injury compared to male rats, the diabetes effect is more profound in females.

Abstract TP79: Inhibition of Toll Like Receptor-4 (tlr4) Improves Neurobehavioral Outcomes After Acute Ischemic Stroke in Diabetic Rats

Introduction: Diabetes increases the risk of occurrence and poor recovery of ischemic stroke injury. Activation of adaptive immune system and resulting inflammation contributes to neurovascular injury and deterioration of neurological functions post stroke in diabetes. We have shown that activation of TLR4, a key player in the innate immune system, decreases brain microvascular endothelial cell survival after hypoxic injury in diabetic conditions. Our previous work also demonstrated greater bleeding/edema and poor recovery after stroke in diabetes. Current study tested the hypothesis that activation of TLR4 contributes to worsened stroke injury in diabetes and its inhibition can improve functional outcomes.

Methods: Low dose of Streptozotocin (30mg/kg) and high fat diet were used to induce type 2 diabetes in male Wistar rats. Middle cerebral artery occlusion for 60 mins was performed in 13 weeks old animals. Expression of TLR4 receptor in brain homogenates and cerebral microvasculature were assessed by immunoblotting (relative density). Another set of animals was treated with TLR4 inhibitor TAK242 (3mg/kg; i.p. after reperfusion, 24 and 48 hours). Neurobehavioral deficits were measured by composite score and adhesive removal test at baseline, day 1 and 3 post ischemic stroke.

Results: Ischemic stroke increased the expression of TLR4 receptor in ischemic hemisphere (0.50±0.06 sham, 0.68±0.02 control and 1.24±2.0* diabetic; *p<0.05 vs sham) as well as in microvasculature (0.55±035 sham, 1.34±0.24 control and 9.49±2.5* diabetic; *p<0.05 vs sham) and this was significantly higher in diabetic animals. Diabetes worsened functional outcomes and inhibition of TLR4 significantly improved the deficits (Table).

Conclusions: Our findings that TLR4 is highly upregulated in the microvasculature and that beneficial effects of TLR4 inhibition are more profound in diabetes suggest that vascular TLR4 holds a therapeutic potential for stroke recovery in diabetes.

Abstract WMP81: Low Dose tPA Worsens The Short Term Outcomes After Thromboembolic Stroke In Both Male And Female Diabetic Animals

Diabetes worsens stroke outcome and increases the risk of hemorrhagic transformation (HT) after ischemic stroke, especially with tPA treatment. We previously showed that low dose tPA decreased infarct size and improved functional outcome in both male and female control rats with embolic stroke. In the current study, we hypothesized that low dose tPA will also improve the functional recovery after the embolic stroke in both male and female animals with diabetes. Diabetes was induced in age matched male and female Wistar rats with high fat diet and low dose streptozotocin (30 mg/kg, i.p.). Embolic stroke was induced with middle cerebral artery occlusion. The animals were treated with or without tPA (1 mg/kg, i.v.) at 90 min after surgery. Neurological deficits (composite score and adhesive removal test-ART), infarct size, edema ratio, and HT index were assessed 3 days after surgery. The blood flow has increased in the tPA treated animals in the first 1 to 1.5 hr after treatment. The infarct size and edema was not significantly different in untreated animals, but HT was greater in female diabetic rats. The tPA treatment worsened HT in both genders with no change in infarct size. Decline in ART was worsened with tPA treatment in both sexes. Our data suggest that the low dose tPA after ischemic stroke has detrimental effects on the cerebrovascular recovery and functional outcome in both male and female animals with diabetes.

Abstract WP294: Deferoxamine Treatment Improves Outcomes After Embolic Stroke in Diabetic Rats

Diabetes increases the risk of hemorrhagic transformation (HT) after a cerebral ischemic event, a major factor limiting the use of tissue plasminogen activator (tPA) for stroke patients. We previously showed that increased HT is associated with poorer recovery in diabetes. In the current study, we hypothesized that excess iron contributes to poor recovery and that iron chelation with deferoxamine (DFX) will improve the neurological recovery after embolic stroke in diabetes. Diabetes was induced with high fat diet and low dose streptozotocin injection (30 mg/kg) in male Wistar rats. Both control and diabetes animals were subjected to embolic stroke with middle cerebral artery occlusion and sacrificed 2 weeks after the surgery. DFX (100 mg/kg) or vehicle was given every 12 h for 7 days after stroke. The composite score (Bederson’s score and beam walk), adhesive removal (ART) and novel object recognition (NOR) were assessed at day 1, 3, 7 and 14 after the surgery. DFX reduced mortality in diabetes. Diabetic animals displayed poor outcomes. By Day 14, DFX reduced motor and cognitive deficits in diabetes but not in controls. These results suggest that iron chelation therapy may improve outcomes after ischemic stroke in this high risk population.