Kathryn Fischbach

Neuronal mitochondrial amelioration by feeding acetyl-L-carnitine and lipoic acid to aged rats

Brain function declines with age and is associated with diminishing mitochondrial integrity. The neuronal mitochondrial ultrastructural changes of young (4 months) and old (21 months) F344 rats supplemented with two mitochondrial metabolites, acetyl‐L‐carnitine (ALCAR, 0.2%[wt/vol] in the drinking water) and R‐α‐lipoic acid (LA, 0.1%[wt/wt] in the chow), were analysed using qualitative and quantitative electron microscopy techniques. Two independent morphologists blinded to sample identity examined and scored all electron micrographs. Mitochondria were examined in each micrograph, and each structure was scored according to the degree of injury. Controls displayed an age‐associated significant decrease in the number of intact mitochondria (P = 0.026) as well as an increase in mitochondria with broken cristae (P < 0.001) in the hippocampus as demonstrated by electron microscopic observations. Neuronal mitochondrial damage was associated with damage in vessel wall cells, especially vascular endothelial cells. Dietary supplementation of young and aged animals increased the proliferation of intact mitochondria and reduced the density of mitochondria associated with vacuoles and lipofuscin. Feeding old rats ALCAR and LA significantly reduced the number of severely damaged mitochondria (P = 0.02) and increased the number of intact mitochondria (P < 0.001) in the hippocampus. These results suggest that feeding ALCAR with LA may ameliorate age‐associated mitochondrial ultrastructural decay and are consistent with previous studies showing improved brain function.

The effect of acetyl-L-carnitine and R-α-lipoic acid treatment in ApoE4 mouse as a model of human Alzheimer's disease

We measured age-dependent effects of human ApoE4 on cerebral blood flow (CBF) using ApoE4 transgenic mice compared to age-matched wild-type (WT) mice by use of [(14)C] iodoantipyrene autoradiography. ApoE4 associated factors reduce CBF gradually to create brain hypoperfusion when compared to WT, and the differences in CBF are greatest as animals age from 6-weeks to 12-months. Transmission electron microscopy with colloidal gold immunocytochemistry showed structural damage in young and aged microvessel endothelium of ApoE4 animals extended to the cytoplasm of perivascular cells, perivascular nerve terminals and hippocampal neurons and glial cells. These abnormalities coexist with mitochondrial structural alteration and mitochondrial DNA overproliferation and/or deletion in all brain cellular compartments. Spatial memory and temporal memory tests showed a trend in improving cognitive function in ApoE4 mice fed selective mitochondrial antioxidants acetyl-l-carnitine and R-alpha-lipoic acid. Our findings indicate that ApoE4 genotype-induced mitochondrial changes and associated structural damage may explain age-dependent pathology seen in AD, indicating potential for novel treatment strategies in the near future.

Nitric Oxide as an Initiator of Brain Lesions During the Development of Alzheimer Disease

Nitric oxide (NO) is an important regulatory molecule for the host defense that plays a fundamental role in the cardiovascular, immune, and nervous systems. NO is synthesized through the conversion of l-arginine to l-citrulline by the enzyme NO synthase (NOS), which is found in three isoforms classified as neuronal (nNOS), inducible (iNOS), and endothelial (eNOS). Recent evidence supports the theory that this bioactive molecule has an influential role in the disruption of normal brain and vascular homeostasis, a condition known to elucidate chronic hypoperfusion which ultimately causes the development of brain lesions and the pathology that typify Alzheimer disease (AD). In addition, vascular NO activity appears to be a major contributor to this pathology before any overexpression of NOS isoforms is observed in the neuron, glia, and microglia of the brain tree, where the overexpression the NOS isoforms causes the formation of a large amount of NO. We hypothesize that since an imbalance between the NOS isoforms and endothelin-1 (ET-1), a human gene that encodes for blood vessel constriction, can cause antioxidant system insufficiency; by using pharmacological intervention with NO donors and/or NO suppressors, the brain lesions and the downstream progression of brain pathology and dementia in AD should be delayed or minimized.

Variant in sulfonylurea receptor-1 gene is associated with high insulin concentrations in non-diabetic Mexican Americans: SUR-1 gene variant and hyperinsulinemia

Abstract The high-affinity sulfonylurea receptor (SUR1) gene regulates insulin secretion and may play a role in type 2 diabetes. A silent variant in exon 31 of SUR1 (AGG→AGA) was detected by single-strand conformational polymorphism and genotypes were determined for 396 Mexican American subjects (289 non-diabetic). The normal and mutant alleles were designated G and A, respectively. Among non-diabetics, those with the AA genotype had higher fasting insulin values than those with the AG and GG genotypes (113.4 pmol/l for AA vs 82.8 pmol/l for AG/GG, P=0.043). Similar results were observed for 2-h insulin (849.6 pmοl/l for AA vs 498.6 pmol/l for AG/GG, P=0.0003) and for the proinsulin to specific insulin ratio (0.068 for AA vs 0.056 for AG/GG, P=0.030). Specific insulin levels also differed significantly across the three genotypic classes (P=0.021). No differences in fasting glucose, body mass index, or waist circumference according to genotype were noted. Two-hour glucose was modestly higher in individuals with the AA genotype. Since we have previously reported linkage between SUR1 and hyperglycemia, the present association between a SUR1 variant and hyperinsulinemia in normal individuals from a high diabetes risk ethnic group raises the possibility of primary insulin hypersecretion as an antecedent of type 2 diabetes in at least some individuals from this population.

Atherosclerotic lesions and mitochondria DNA deletions in brain microvessels: Implication in the pathogenesis of Alzheimer’s disease

The pathogenesis that is primarily responsible for Alzheimer’s disease (AD) and cerebrovascular accidents (CVA) appears to involve chronic hypoperfusion. We studied the ultrastructural features of vascular lesions and mitochondria in brain vascular wall cells from human AD biopsy samples and two transgenic mouse models of AD, yeast artificial chromosome (YAC) and C57B6/SJL Tg (+), which overexpress human amyloid beta precursor protein (AβPP). In situ hybridization using probes for normal and 5 kb deleted human and mouse mitochondrial DNA (mtDNA) was performed along with immunocytochemistry using antibodies against the Aβ peptide processed from AβPP, 8-hydroxy-2’-guanosine (8OHG), and cytochrome c oxidase (COX). More amyloid deposition, oxidative stress markers as well as mitochondrial DNA deletions and structural abnormalities were present in the vascular walls of the human AD samples and the AβPP-YAC and C57B6/SJL Tg (+) transgenic mice compared to age-matched controls. Ultrastructural damage in perivascular cells highly correlated with endothelial lesions in all samples. Therefore, pharmacological interventions, directed at correcting the chronic hypoperfusion state, may change the natural course of the development of dementing neurodegeneration.

Insights into cerebrovascular complications and Alzheimer disease through the selective loss of GRK2 regulation

•  Introduction •  General features of GRKs •  Expression patterns of GRK2 •  GRK, ET‐1 and Insulin signalling •  GRK studies In AD and CBH •  Conclusions

Stem cell niches as clinical targets: the future of anti-ischemic therapy?

This article provides context for the research presented by Napoli et al., reported in this journal. Treatment strategies that target stem cell niches are promising avenues for stimulating inducible angiogenesis in many vascular diseases, such as diabetes mellitus and atherosclerosis. Here we discuss the study carried out by Napoli and colleagues—an analysis of the effects of parathyroid hormone on the vascular stem cell niche in peripheral ischemia. Napoli et al. demonstrate that parathyroid hormone administered in combination with granulocyte colony-stimulating factor induces angiogenesis in a hindlimb ischemia mouse model. This treatment seems to mobilize and localize endothelial cell progenitors specifically to ischemic vascular cell beds. We explore the mechanisms through which the multiple cells within the vascular niche respond to ischemia. The interaction between parathyroid hormone and granulocyte colony-stimulating factor in humans is also discussed. Further assessment is needed to elucidate the factors involved in migration and differentiation of endothelial cell progenitors in ischemia-damaged tissues.

Preventing cognitive decline in elderly demented/depressed patients and in ApoE4 mouse as a model of human Alzheimer's disease by feeding acetyl-l-carnitine and lipoic acid

O4-02-03 PREVENTING COGNITIVE DECLINE IN ELDERLY DEMENTED/DEPRESSED PATIENTS AND IN APOE4 MOUSE AS A MODEL OF HUMAN ALZHEIMER’S DISEASE BY FEEDING ACETYL-L-CARNITINE AND LIPOIC ACID Gjumrakch Aliev, Jiankang Liu, Amanda Lipsitt, Kathryn Fischbach, Mark E. Obrenovich, Bruce N. Ames, Eldar Qasimov, Joseph C. LaManna, Ludis Morales, Valentin Bragin, Stress Relief Center, Brooklyn, NY, USA; Departamento de Nutrición y Bioquı́mica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia; Children’s Hospital Oakland Research Institute, Oakland, CA, USA; Department of Infectious Diseases, Medicine University of Texas Health Science Center at San Antonio, San Antonio, TX, USA; The University of Texas at San Antonio, San Antonio, TX, USA; Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA; Department of Cytology, Histology and Embryology, Baku Medical University, Baku, Azerbaijan; Department of Physiology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA. Contact e-mail: aliev03@ gmail.com

P4-171: Cerebral hypoperfusion-induced oxidative stress and mitochondrial failure as initiators of aging and Alzheimer's disease pathology

Gjumrakch Aliev, Justin C. Shenk, Kathryn Fischbach, Celia J. Cobb, Gerardo J. Pacheco, Eldar Gasimov, George Perry, Department of Biology, and Electron Microscopy Research Center, University of Texas at San Antonio, San Antonio, TX, USA; Department of Cytology, Histology and Embryology, Azerbaijan Medical University, Baku, Azerbaijan; College of Sciences, University of Texas at San Antonio, San Antonio, TX, USA; Case Western Reserve University, Cleveland, OH, USA. Contact e-mail: gjumrakch.aliev@utsa.edu