pkh-26 and Alzheimer-Disease

Alzheimer's disease (AD) is characterized by extracellular beta-amyloid plaques and intracellular tau tangles. AD-related pathology is often accompanied by vascular changes. The predominant vascular lesions in AD are cerebral amyloid angiopathy (CAA) and arteriosclerosis. Platelets circulate along the vessel wall responding immediately to vascular injury. The aim of the present study was to explore the presence and migration of platelets (thrombocytes) to sites of small vascular bleedings and/or to beta-amyloid plaques in the brain. We infused fluorescently labeled red PKH26 mouse platelets into transgenic Alzheimer mice overexpressing APP with Swedish/Dutch/Iowa mutations (APP_SDI) and explored if platelets migrate into the brain. Further we studied whether platelets accumulate in the vicinity of β-amyloid plaques. Our animal data shows that infused platelets are found in the liver and partly in the lung, while in the brain platelets were visible to a minor degree. In mice, we did not observe a significant association of platelets with beta-amyloid plaques or vessels. In the brain of Alzheimer postmortem patients platelets could be detected by immunohistochemistry for CD41 and CD62P, but the majority was found in vessels with or without beta-amyloid load, and only a few single platelets migrated deeper into the brain. Our findings suggest that platelets do not migrate into the brains of Alzheimer disease but are concentrated in brain vessels.

Topics: Adult; Aged; Aged, 80 and over; Alzheimer Disease; Amyloid beta-Protein Precursor; Animals; Blood Platelets; Brain; Cerebral Amyloid Angiopathy; Cyclin-Dependent Kinase Inhibitor p21; Disease Models, Animal; Female; Flow Cytometry; Humans; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Organic Chemicals; P-Selectin; Platelet Membrane Glycoprotein IIb

Alzheimer's disease is a neurodegenerative disorder clinically characterized by cognitive dysfunction and by deposition of amyloid plaques, neurofibrillary tangles in the brain. The study investigated the therapeutic effect of combined mesenchymal stem cells and erythropoietin on Alzheimer's disease. Five groups of mice were used: control group, Alzheimer's disease was induced in four groups by a single intraperitoneal injection of 0.8 mg kg(-1) lipopolysaccharide and divided as follows: Alzheimer's disease group, mesenchymal stem cells treated group by injecting mesenchymal stem cells into the tail vein (2 x 10(6) cells), erythropoietin treated group (40 microg kg(-1) b.wt.) injected intraperitoneally 3 times/week for 5 weeks and mesenchymal stem cells and erythropoietin treated group. Locomotor activity and memory were tested using open field and Y-maze. Histological, histochemical, immunohistochemical studies, morphometric measurements were examined in brain sections of all groups. Choline transferase activity, brain derived neurotrophic factor expression and mitochondrial swellings were assessed in cerebral specimens. Lipopolysaccharide decreased locomotor activity, memory, choline transferase activity and brain derived neurotrophic factor. It increased mitochondrial swelling, apoptotic index and amyloid deposition. Combined mesenchymal stem cells and erythropoietin markedly improved all these parameters. This study proved the effective role of mesenchymal stem cells in relieving Alzheimer's disease symptoms and manifestations; it highlighted the important role of erythropoietin in the treatment of Alzheimer's disease.

Topics: Alzheimer Disease; Animals; Brain; Brain-Derived Neurotrophic Factor; Choline O-Acetyltransferase; Cognition; Endoglin; Erythropoietin; Gene Expression Regulation; Intracellular Signaling Peptides and Proteins; Lipopolysaccharides; Locomotion; Male; Maze Learning; Mesenchymal Stem Cell Transplantation; Mice; Mitochondrial Size; Organic Chemicals; Treatment Outcome

To investigate the migration of fluorescent dye PKH26-labeled BM-MSC in the Alzheimer's model rats.. Normal human bone marrow extracted for isolation of BM-MSC was cultured in vitro. The 5th passaged BM-MSC was labeled with PKH26, and observed under a fluorescence microscope for PKH26 labeling efficiency, and using flow cytometry BM-MSC surface markers was checked. The PKH26 labeled BM-MSC injected into the tail vein of the normal control group and AD animal model group, 14 days after finding the PKH26-labeled BM-MSC cells in the rat hippocampus using fluorescence microscopy. Using the Morris water maze experiment comparison of AD model and BM-MSC transplantation group of spatial learning and memory ability.. TFlow cytometry showed BM-MSC surface markers CD73 and CD105 were positive. In vitro, PKH26-labeled rate of BM-MSC was 100 %. The Morris water maze experiment comparison of BM-MSC transplantation group and AD group of animals, BM-MSC transplantation group at 13, 14 days of spatial learning and memory ability than AD animal group had significantly improved. 14 days after BM-MSCs in rat hippocampus could be found which were PKH26-positive, consistent with DAPI staining. PKH26-positive cells in animal models of AD were significantly more than those in the normal control group.. BM-MSC in AD rats not only migrates through the blood-brain barrier, but also mainly survives in the hippocampus of AD rats, and it can improve AD rat model of learning disabilities.

Topics: Alzheimer Disease; Animals; Bone Marrow Cells; Cell Movement; Cells, Cultured; Disease Models, Animal; Humans; Injections, Intravenous; Male; Mesenchymal Stem Cells; Organic Chemicals; Rats; Rats, Sprague-Dawley