Charlie Norwood VA Medical Center

About: Charlie Norwood VA Medical Center is a healthcare organization based out in Augusta, Georgia, United States. It is known for research contribution in the topics: Autophagy & Kidney. The organization has 349 authors who have published 490 publications receiving 16360 citations. The organization is also known as: Augusta VA Medical Center.

Candesartan reduces the hemorrhage associated with delayed tissue plasminogen activator treatment in rat embolic stroke.

Abstract: We have previously reported that angiotensin receptor blockade reduces reperfusion hemorrhage in a suture occlusion model of stroke, despite increasing matrix metalloproteinase (MMP-9) activity. We hypothesized that candesartan will also decrease hemorrhage associated with delayed (6 h) tissue plasminogen activator (tPA) administration after embolic stroke, widening the therapeutic time window of tPA. Adult male Wistar rats were subjected to embolic middle cerebral artery occlusion (eMCAO) and treated with either candesartan (1 mg/kg) alone early at 3 h, delayed tPA (10 mg/kg) alone at 6 h, the combination of candesartan and tPA, or vehicle control. Rats were sacrificed at 24 and 48 h post-eMCAO and brains perfused for evaluation of neurological deficits, cerebral hemorrhage in terms of hemoglobin content, occurrence rate of hemorrhage, infarct size, tissue MMP activity and protein expression. The combination therapy of candesartan and tPA after eMCAO reduced the brain hemorrhage, and improved neurological outcome compared with rats treated with tPA alone. Further, candesartan in combination with tPA increased activity of MMP-9 but decreased MMP-3, nuclear factor kappa-B and tumor necrosis factor-α expression and enhanced activation of endothelial nitric oxide synthase. An activation of MMP-9 alone is insufficient to cause increased hemorrhage in embolic stroke. Combination therapy with acute candesartan plus tPA may be beneficial in ameliorating tPA-induced hemorrhage after embolic stroke.

Examining the Overlap Between Moral Injury and PTSD in US Veterans and Active Duty Military.

Abstract: Moral injury (MI) is a syndrome thought to be separate from posttraumatic stress disorder (PTSD), yet having some overlap. To determine the overlap, we examined the relationship between MI and the four DSM-5 PTSD symptom clusters (B, C, D, E) in US veterans and active duty military (ADM). The 45-item Moral Injury Symptom Scale (MISS-M) was administered to 591 veterans and ADM who had served in a combat theater and had PTSD symptoms. PTSD symptoms were measured with the PTSD Symptom Checklist-5, which assesses the four PTSD symptom clusters. Total MISS-M scores were more strongly associated with PTSD symptom cluster D (negative cognitions and emotions) in both bivariate and multivariate analyses. Findings for a 10-item version of the MISS-M (MISS-M-SF) closely followed those of the MISS-M. Although the overlap between MI and PTSD occurs to some extent across all PTSD symptoms clusters, the largest overlap tends to be with the negative cognitions and emotions cluster.

Minocycline Prevents IL-6 Increase after Acute Ischemic Stroke

Abstract: Higher levels of the inflammatory biomarker interleukin-6 (IL-6) correlate with poor clinical outcome in acute ischemic stroke (AIS). Minocycline (MC) is a known anti-inflammatory agent; thus, the effect of MC on IL-6 in the first 24 h of AIS was investigated to determine potential anti-inflammatory activity. The Minocycline to Improve Neurologic Outcome in Stroke (MINOS) study was a non-randomized dose-escalation (3.0–10.0 mg/kg) trial of IV MC for AIS within 6 h of onset. Plasma IL-6 samples were collected prior to MC treatment at 1, 24, and 72 h and compared to those collected in a separate observational study of blood biomarkers in AIS. IL-6 levels were measured by commercially available ELISA kits. The lower limit of detection for IL-6 was 1 pg/ml. Sixty MINOS subjects and 29 non-MINOS subjects were enrolled, and there was no difference in baseline stroke severity. There was no significant difference in IL-6 level pre-MC treatment at 1, 24, or 72 h. However, the odds of a non-detectable IL-6 at 24 h in MINOS were 8.94 (95% CI 2.62–30.46) compared with non-MINOS subjects. It is likely that even low doses of MC have a potent systemic anti-inflammatory effect in AIS. Whether this results in improved outcome will be tested in a randomized clinical trial.

APP promotes osteoblast survival and bone formation by regulating mitochondrial function and preventing oxidative stress.

Abstract: Amyloid precursor protein (APP) is ubiquitously expressed in various types of cells including bone cells. Mutations in App gene result in early-onset Alzheimer’s disease (AD). However, little is known about its physiological function in bone homeostasis. Here, we provide evidence for APP’s role in promoting bone formation. Mice that knocked out App gene (APP−/−) exhibit osteoporotic-like deficit, including reduced trabecular and cortical bone mass. Such a deficit is likely due in large to a decrease in osteoblast (OB)-mediated bone formation, as little change in bone resorption was detected in the mutant mice. Further mechanical studies of APP−/− OBs showed an impairment in mitochondrial function, accompanied with increased reactive oxygen species (ROS) and apoptosis. Intriguingly, these deficits, resemble to those in Tg2576 animal model of AD that expresses Swedish mutant APP (APPswe), were diminished by treatment with an anti-oxidant NAC (n-acetyl-l-cysteine), uncovering ROS as a critical underlying mechanism. Taken together, these results identify an unrecognized physiological function of APP in promoting OB survival and bone formation, implicate APPswe acting as a dominant negative factor, and reveal a potential clinical value of NAC in treatment of AD-associated osteoporotic deficits.

MBD2 Mediates Septic AKI through Activation of PKCη/p38MAPK and the ERK1/2 Axis.

Abstract: Our previous study demonstrated that the methyl-CpG-binding domain protein 2 (MBD2) mediates vancomycin (VAN)-induced acute kidney injury (AKI). However, the role and regulation of MBD2 in septic AKI are unknown. Herein, MBD2 was induced by lipopolysaccharide (LPS) in Boston University mouse proximal tubules (BUMPTs) and mice. For both in vitro and in vivo experiments, we showed that inhibition of MBD2 by MBD2 small interfering RNA (siRNA) and MBD2-knockout (KO) substantially improved the survival rate and attenuated both LPS and cecal ligation and puncture (CLP)-induced AKI, renal cell apoptosis, and inflammatory factor production. Global genetic expression analyses and in vitro experiments suggest that the expression of protein kinase C eta (PKCη), caused by LPS, is markedly suppressed in MBD2-KO mice and MBD2 siRNA, respectively. Mechanistically, chromatin immunoprecipitation (ChIP) analysis indicates that MBD2 directly binds to promoter region CpG islands of PKCη via suppression of promoter methylation. Furthermore, PKCη siRNA improves the survival rate and attenuates LPS-induced BUMPT cell apoptosis and inflammatory factor production via inactivation of p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase (ERK)1/2, which were further verified by PKCη siRNA treatment in CLP-induced AKI. Finally, MBD2-KO mice exhibited CLP-induced renal cell apoptosis and inflammatory factor production by inactivation of PKCη/p38MAPK and ERK1/2 signaling. Taken together, the data indicate that MBD2 mediates septic-induced AKI through the activation of PKCη/p38MAPK and the ERK1/2 axis. MBD2 represents a potential target for treatment of septic AKI.