Aß promotes CD38 expression in senescent microglia in Alzheimer's disease.

BACKGROUND: In Alzheimer's disease (AD), the neuroinflammatory response mediated by the activation of senescent microglia is closely related to energy dysmetabolism. However, the mechanism underlying the interaction between the energy metabolism of aging microglia and neuroinflammation remains unclear. METHODS: We used biochemical methods, enzyme-linked immunosorbent assay (ELISA), immunofluorescence, and western blot to determine the effects and mechanism of CD38 knockdown on energy metabolism and neuroinflammation in Aß1-40 injured BV2 cells. Using AD model mice, we detected CD38 enzyme activity, energy metabolism factors (ATP, NAD +, and NAD + /NADH), and neuroinflammatory factors (IL-1ß, IL-6, and TNF-α) following the addition of CD38 inhibitor. Using a combination of biochemical analysis and behavioral testing, we analyzed the effects of the CD38 inhibitor on energy metabolism disorder, the neuroinflammatory response, and the cognition of AD mice. RESULTS: Following Aß1-40 injury, SA-ß-Gal positive cells and senescence-related proteins P16 and P21 increased in BV2 cells, while energy-related molecules (ATP, NAD +, and NAD + /NADH) and mitochondrial function (mitochondrial ROS and MMP) decreased. Further studies showed that CD38 knockdown could improve Aß1-40-induced BV2 cells energy dysmetabolism and reduce the levels of IL-1ß, IL-6, and TNF-α. In vivo results showed an increase in senile plaque deposition and microglial activation in the hippocampus and cortex of 34-week-old APP/PS1 mice. Following treatment with the CD38 inhibitor, senile plaque deposition decreased, the number of Iba1 + BV2 cells increased, the energy metabolism disorder was improved, the proinflammatory cytokines were reduced, and the spatial learning ability was improved. CONCLUSIONS: Our results confirm that senescent microglia appeared in the brain of 34-week-old APP/PS1 mice, and that Aß1-40 can induce senescence of BV2 cells. The expression of CD38 increases in senescent BV2 cells, resulting in energy metabolism disorder. Therefore, reducing CD38 expression can effectively improve energy metabolism disorder and reduce proinflammatory cytokines. Following intervention with the CD38 inhibitor in APP/PS1 mice, the energy metabolism disorder was improved in the hippocampus and cortex, the level of proinflammatory cytokines was reduced, and cognitive impairment was improved.

Aß promotes CD38 expression in senescent microglia in Alzheimer's disease

BACKGROUND: In Alzheimer's disease (AD), the neuroinflammatory response mediated by the activation of senescent microglia is closely related to energy dysmetabolism. However, the mechanism underlying the interaction between the energy metabolism of aging microglia and neuroinflammation remains unclear. METHODS: We used biochemical methods, enzyme-linked immunosorbent assay (ELISA), immunofluorescence, and western blot to determine the effects and mechanism of CD38 knockdown on energy metabolism and neuroinflammation in Aß1-40 injured BV2 cells. Using AD model mice, we detected CD38 enzyme activity, energy metabolism factors (ATP, NAD +, and NAD +/NADH), and neuroinflammatory factors (IL-1ß, IL-6, and TNF-α) following the addition of CD38 inhibitor. Using a combination of biochemical analysis and behavioral testing, we analyzed the effects of the CD38 inhibitor on energy metabolism disorder, the neuroinflammatory response, and the cognition of AD mice. RESULTS: Following Aß1-40 injury, SA-ß-Gal positive cells and senescence-related proteins P16 and P21 increased in BV2 cells, while energy-related molecules (ATP, NAD +, and NAD +/NADH) and mitochondrial function (mitochondrial ROS and MMP) decreased. Further studies showed that CD38 knockdown could improve Aß1-40-induced BV2 cells energy dysmetabolism and reduce the levels of IL-1ß, IL-6, and TNF-α. In vivo results showed an increase in senile plaque deposition and microglial activation in the hippocampus and cortex of 34-week-old APP/PS1 mice. Following treatment with the CD38 inhibitor, senile plaque deposition decreased, the number of Iba1 +BV2 cells increased, the energy metabolism disorder was improved, the proinflammatory cytokines were reduced, and the spatial learning ability was improved. CONCLUSIONS: Our results confirm that senescent microglia appeared in the brain of 34-week-old APP/PS1 mice, and that Aß1-40 can induce senescence of BV2 cells. The expression of CD38 increases in senescent BV2 cells, resulting in energy metabolism disorder. Therefore, reducing CD38 expression can effectively improve energy metabolism disorder and reduce proinflammatory cytokines. Following intervention with the CD38 inhibitor in APP/PS1 mice, the energy metabolism disorder was improved in the hippocampus and cortex, the level of proinflammatory cytokines was reduced, and cognitive impairment was improved.

Permanent His Bundle Pacing Implantation Facilitated by Visualization of the Tricuspid Valve Annulus.

BACKGROUND: His bundle pacing (HBP) is the most physiological pacing modality. However, HBP has longer procedure times with frequent high capture thresholds, which likely contributes to the low adoption of this approach. The aim of this study is to compare HBP implantation with a novel imaging technique versus the standard implantation technique. METHODS: This study included 50 patients with standard pacing indications randomized to HBP with visualization of the tricuspid valve annulus (N=25, the visualization group) or with the standard method (N=25, the control group). In the visualization group, the tricuspid valve annulus was imaged by contrast injection in the right ventricle during fluoroscopy. The site for HBP was identified in relationship to the tricuspid septal leaflet and interventricular septum. RESULTS: Permanent HBP was successful in 92% in the visualization group and 88% in the control group. The fluoroscopic time for HBP lead placement was significantly shorter in the visualization group (7.1±3.3 minutes) compared with the control group (10.1±5.6 minutes, P=0.03). Total procedural and fluoroscopic times were also significantly shorter in the visualization group (91.0±15.7 and 9.6±3.8 minutes) than the control group (104.4±17.8 and 12.7±6.2 minutes, P=0.01 and 0.04, respectively). There was no significant difference in capture threshold between groups. In the visualization group, there was a quantitative association between the HBP site and the tricuspid valve annulus. CONCLUSIONS: The visualization technique shortens the procedural and fluoroscopic times for HBP implantation. Moreover, anatomic localization of HBP sites is strongly associated with physiological characteristics of pacing, which can help guide optimal lead placement. Registration: URL: https://www.chictr.org.cn/index.aspx. Unique identifier: ChiCTR2000029834.

ABT-450, ritonavir, ombitasvir, and dasabuvir achieves 97% and 100% sustained virologic response with or without ribavirin in treatment-experienced patients with HCV genotype 1b infection.

BACKGROUND & AIMS: The interferon-free regimen of ABT-450 (a protease inhibitor), ritonavir, ombitasvir (an NS5A inhibitor), dasabuvir (a non-nucleoside polymerase inhibitor), and ribavirin has shown efficacy in patients with hepatitis C virus (HCV) genotype 1b infection-the most prevalent subgenotype worldwide. We evaluated whether ribavirin is necessary for ABT-450, ritonavir, ombitasvir, and dasabuvir to produce high rates of sustained virologic response (SVR) in these patients. METHODS: We performed a multicenter, open-label, phase 3 trial of 179 patients with HCV genotype 1b infection, without cirrhosis, previously treated with peginterferon and ribavirin. Patients were assigned randomly (1:1) to groups given ABT-450, ritonavir, ombitasvir, and dasabuvir, with ribavirin (group 1) or without (group 2) for 12 weeks. The primary end point was SVR 12 weeks after treatment (SVR12). We assessed the noninferiority of this regimen to the rate of response reported (64%) for a similar population treated with telaprevir, peginterferon, and ribavirin. RESULTS: Groups 1 and 2 each had high rates of SVR12, which were noninferior to the reported rate of response to the combination of telaprevir, peginterferon, and ribavirin (group 1: 96.6%; 95% confidence interval, 92.8%-100%; and group 2: 100%; 95% confidence interval, 95.9%-100%). The rate of response in group 2 was noninferior to that of group 1. No virologic failure occurred during the study. Two patients (1.1%) discontinued the study owing to adverse events, both in group 1. The most common adverse events in groups 1 and 2 were fatigue (31.9% vs 15.8%) and headache (24.2% vs 23.2%), respectively. Decreases in hemoglobin level to less than the lower limit of normal were more frequent in group 1 (42.0% vs 5.5% in group 2; P < .001), although only 2 patients had hemoglobin levels less than 10 g/dL. CONCLUSIONS: The interferon-free regimen of ABT-450, ritonavir, ombitasvir, and dasabuvir, with or without ribavirin, produces a high rate of SVR12 in treatment-experienced patients with HCV genotype 1b infection. Both regimens are well tolerated, as shown by the low rate of discontinuations and generally mild adverse events. ClinicalTrials.gov number: NCT01674725.