losartan-potassium and Atrophy

Neurodevelopmental abnormalities together with neurodegenerative processes contribute to schizophrenia, an etiologically heterogeneous, complex disease phenotype that has been difficult to model in animals. The neurodegenerative component of schizophrenia is best documented by magnetic resonance imaging (MRI), demonstrating progressive cortical gray matter loss over time. No treatment exists to counteract this slowly proceeding atrophy. The hematopoietic growth factor erythropoietin (EPO) is neuroprotective in animals. Here, we show by voxel-based morphometry in 32 human subjects in a placebo-controlled study that weekly high-dose EPO for as little as 3 months halts the progressive atrophy in brain areas typically affected in schizophrenia, including hippocampus, amygdala, nucleus accumbens, and several neocortical areas. Specifically, gray matter protection is highly associated with improvement in attention and memory functions. These findings suggest that a neuroprotective strategy is effective against common pathophysiological features of schizophrenic patients, and strongly encourage follow-up studies to optimize EPO treatment dose and duration.

Topics: Adult; Analysis of Variance; Atrophy; Attention; Brain; Double-Blind Method; Erythropoietin; Humans; Male; Memory; Middle Aged; Neuroprotective Agents; Recombinant Proteins; Schizophrenia; Treatment Outcome

This study aims to explore the radioprotective effects of recombinant human erythropoietin (rhEPO) on rats' submandibular gland hypofunction induced by irradiation (IR).. Thirty rats were divided into 3 groups: 1) control group, 2) IR group, and 3) IR + rhEPO group. The IR group and IR + rhEPO group received a single dose of 15 Grays (Gy) (0.98 Gy/min), plus, the IR + rhEPO group also received subcutaneous administration of rhEPO at a dose of 3,000 IU/kg body weight 3 days before irradiation and then repeated every 24 hours for the first 2 weeks after irradiation. Immunohistochemistry analysis to erythropoietin receptor was performed to detect the levels of erythropoietin receptor in submandibular glands with or without radiation. Ninety days after irradiation, the salivary flow rates were assessed, and the submandibular gland of every rat was subjected to hematoxylin and eosin staining and immunohistochemical staining with antiaquaporin 5 and anti-proliferating cell nuclear antigen antibodies. Apoptosis was examined by the terminal deoxynucleotidyl transferase biotin-dUDP nick end-labeling assay. In addition, to examine the protective role of rhEPO on human submandibular gland cells, the apoptotic and proliferation rate of cells under a radiation dose of 8 Gy was detected. One-way analysis of variance was carried out to analyze the results of each group, and the P value was set at 0.05.. Erythropoietin receptor was expressed in the submandibular glands at a low level under normal conditions but upregulated after irradiation. rhEPO administration remarkably alleviated gland atrophy, increased salivary flow rates with upregulation of aquaporin-5 compared with the IR group. In addition, fewer apoptotic cells and more proliferative cells were observed in the IR + rhEPO group compared with the IR group, both in vivo and in vitro.. rhEPO administration may be a useful countermeasure to mitigate submandibular gland hypofunction after therapeutic radiation exposure.

Topics: Animals; Apoptosis; Atrophy; Erythropoietin; Rats; Recombinant Proteins; Submandibular Gland

Huntington's disease (HD) is an incurable neurodegenerative disorder caused by a trinucleotide (CAG) repeat expansion in the huntingtin gene (HTT). The R6/2 transgenic mouse model of HD expresses exon 1 of the human HTT gene with approximately 150 CAG repeats. R6/2 mice develop progressive behavioural abnormalities, impaired neurogenesis, and atrophy of several brain regions. In recent years, erythropoietin (EPO) has been shown to confer neuroprotection and enhance neurogenesis, rendering it a promising molecule to attenuate HD symptoms. In this study, the therapeutic potential of EPO was evaluated in female R6/2 transgenic mice. A single bilateral injection of a lentivirus encoding human EPO (LV-hEPO) was performed into the lateral ventricles of R6/2 mice at disease onset (8 weeks of age). Control groups were either untreated or injected with a lentivirus encoding green fluorescent protein (LV-GFP). Thirty days after virus administration, hEPO mRNA and protein were present in injected R6/2 brains. Compared to control R6/2 mice, LV-hEPO-treated R6/2 mice exhibited reduced hippocampal atrophy, increased neuroblast branching towards the dentate granular cell layer, and improved spatial cognition. Our results suggest that LV-hEPO administration may be a promising strategy to reduce cognitive impairment in HD.

Topics: Animals; Atrophy; Cognition; Disease Models, Animal; Erythropoietin; Female; Genetic Therapy; Hippocampus; Huntington Disease; Injections, Intraventricular; Lentivirus; Mice; Mice, Transgenic; Neural Stem Cells; Organ Size; Spatial Navigation; Transfection

Using magnetic resonance imaging (MRI) protocols of T(2)-, T(2)*-, diffusion- and susceptibility-weighted imaging (T2WI, T2*WI, DWI, and SWI, respectively) with a 7T system, we tested the hypothesis that treatment of embolic stroke with erythropoietin (EPO) initiated at 24 hr and administered daily for 7 days after stroke onset has benefit in repairing ischemic cerebral tissue. Adult Wistar rats were subjected to embolic stroke by means of middle cerebral artery occlusion (MCAO) and were randomly assigned to a treatment (n = 11) or a control (n = 11) group. The treated group was given EPO intraperitoneally at a dose of 5,000 IU/kg daily for 7 days starting 24 hr after MCAO. Controls were given an equal volume of saline. MRI was performed at 24 hr and then weekly for 6 weeks. MRI and histological measurements were compared between groups. Serial T2WI demonstrated that expansion of the ipsilateral ventricle was significantly reduced in the EPO-treated rats. The volume ratio of ipsilateral parenchymal tissue relative to the contralateral hemisphere was significantly increased after EPO treatment compared with control animals, indicating that EPO significantly reduces atrophy of the ipsilateral hemisphere, although no significant differences in ischemic lesion volume were observed between the two groups. Angiogenesis and white matter remodeling were significantly increased and occurred earlier in EPO-treated animals than in the controls, as evident from T2*WI and diffusion anisotropy maps, respectively. These data indicate that EPO treatment initiated 24 hr poststroke promotes angiogenesis and axonal remodeling in the ischemic boundary, which may potentially reduce atrophy of the ipsilateral hemisphere.

Topics: Animals; Atrophy; Disease Models, Animal; Erythropoietin; Intracranial Embolism; Magnetic Resonance Imaging; Male; Nerve Degeneration; Neuroprotective Agents; Random Allocation; Rats; Rats, Wistar; Recombinant Proteins; Stroke

A small experimental cryolesion to the right parietal cortex of juvenile mice causes late-onset global brain atrophy with memory impairments, reminiscent of cognitive decline, and progressive brain matter loss in schizophrenia. However, the cellular events underlying this global neurodegeneration are not understood. Here we show, based on comprehensive stereological analysis, that early unilateral lesion causes immediate and lasting bilateral increase in the number of microglia in cingulate cortex and hippocampus, consistent with a chronic low-grade inflammatory process. Whereas the total number of neurons and astrocytes in these brain regions remain unaltered, pointing to a non- gliotic neurodegeneration (as seen in schizophrenia), the subgroup of parvalbumin-positive inhibitory GABAergic interneurons is increased bilaterally in the hippocampus, as is the expression of the GABA-synthesizing enzyme GAD67. Moreover, unilateral parietal lesion causes a decrease in the expression of synapsin1, suggesting impairment of presynaptic functions/neuroplasticity. Reduced expression of the myelin protein cyclic nucleotide phosphodiesterase, reflecting a reduction of oligodendrocytes, may further contribute to the observed brain atrophy. Remarkably, early intervention with recombinant human erythropoietin (EPO), a hematopoietic growth factor with multifaceted neuroprotective properties (intraperitoneal injection of 5000 IU/kg body weight every other day for 3 weeks), prevented all these neurodegenerative changes. To conclude, unilateral parietal lesion of juvenile mice induces a non- gliotic neurodegenerative process, susceptible to early EPO treatment. Although the detailed mechanisms remain to be defined, these profound EPO effects open new ways for prophylaxis and therapy of neuropsychiatric diseases, e.g. schizophrenia.

Topics: Animals; Astrocytes; Atrophy; Brain; Brain Injuries; Cold Temperature; Cyclic Nucleotide Phosphodiesterases, Type 3; Disease Models, Animal; Erythropoietin; gamma-Aminobutyric Acid; Gliosis; Glutamate Decarboxylase; Humans; Male; Mice; Mice, Inbred C57BL; Microglia; Neurodegenerative Diseases; Neurons; Parvalbumins; Synapsins

Inspired from preconditioning studies, ischemic postconditioning, consisting of the application of intermittent interruptions of blood flow shortly after reperfusion, has been described in cardiac ischemia and recently in stroke. It is well known that ischemic tolerance can be achieved in the brain not only by ischemic preconditioning, but also by hypoxic preconditioning. However, the existence of hypoxic postconditioning has never been reported in cerebral ischemia.. Adult mice subjected to transient middle cerebral artery occlusion underwent chronic intermittent hypoxia starting either 1 or 5 days after ischemia and brain damage was assessed by T2-weighted MRI at 43 days. In addition, we investigated the potential neuroprotective effect of hypoxia applied after oxygen glucose deprivation in primary neuronal cultures.. The present study shows for the first time that a late application of hypoxia (5 days) after ischemia reduced delayed thalamic atrophy. Furthermore, hypoxia performed 14 hours after oxygen glucose deprivation induced neuroprotection in primary neuronal cultures. We found that hypoxia-inducible factor-1alpha expression as well as those of its target genes erythropoietin and adrenomedullin is increased by hypoxic postconditioning. Further studies with pharmacological inhibitors or recombinant proteins for erythropoietin and adrenomedullin revealed that these molecules participate in this hypoxia postconditioning-induced neuroprotection.. Altogether, this study demonstrates for the first time the existence of a delayed hypoxic postconditioning in cerebral ischemia and in vitro studies highlight hypoxia-inducible factor-1alpha and its target genes, erythropoietin and adrenomedullin, as potential effectors of postconditioning.

Topics: Adrenomedullin; Animals; Atrophy; Brain; Cells, Cultured; Cytoprotection; Disease Models, Animal; Energy Metabolism; Erythropoietin; Hypoxia-Inducible Factor 1, alpha Subunit; Hypoxia-Ischemia, Brain; Hypoxia, Brain; Infarction, Middle Cerebral Artery; Male; Mice; Nerve Degeneration; Oxidative Stress; Time Factors

The administration of CD34-positive cells after stroke has been shown to have a beneficial effect on functional recovery by accelerating angiogenesis and neurogenesis in rodent models. Granulocyte colony-stimulating factor (G-CSF) is known to mobilize CD34-positive cells from bone marrow and has displayed neuroprotective properties after transient ischemic stress. This led us to investigate the effects of G-CSF administration after stroke in mouse. We utilized permanent ligation of the M1 distal portion of the left middle cerebral artery to develop a reproducible focal cerebral ischemia model in CB-17 mice. Animals treated with G-CSF displayed cortical atrophy and impaired behavioral function compared with controls. The negative effect of G-CSF on outcome was associated with G-CSF induction of an exaggerated inflammatory response, based on infiltration of the peri-infarction area with CD11b-positive and F4/80-positive cells. Although clinical trials with G-CSF have been started for the treatment of myocardial and limb ischemia, our results indicate that caution should be exercised in applying these results to cerebral ischemia.

Topics: Animals; Atrophy; Brain Ischemia; Data Interpretation, Statistical; Erythropoietin; Granulocyte Colony-Stimulating Factor; Immunohistochemistry; Mice; Middle Cerebral Artery; Necrosis; Neovascularization, Pathologic; Recombinant Proteins; Stroke; Treatment Outcome

In humans, neurotrauma is suspected to cause brain atrophy and accelerate slowly progressive neurodegenerative disorders, such as Alzheimer's disease or schizophrenia. However, a direct link between brain injury and subsequent delayed global neurodegeneration has remained elusive. Here we show that juvenile (4-week-old) mice that are given a discrete unilateral lesion of the parietal cortex, develop to adulthood without obvious clinical symptoms. However, when monitored 3 and 9 months after lesioning, using high-resolution three-dimensional MRI and behavioural testing, the same mice display global neurodegenerative changes. Surprisingly, erythropoietin, a haematopoietic growth factor with potent neuroprotective activity, prevents behavioural abnormalities, cognitive dysfunction and brain atrophy when given for 2 weeks after acute brain injury. This demonstrates that a localized brain lesion is a primary cause of delayed global neurodegeneration that can be efficiently counteracted by neuroprotection.

Topics: Acute Disease; Animals; Atrophy; Brain; Brain Injuries; Erythropoietin; Magnetic Resonance Imaging; Male; Mice; Mice, Inbred BALB C; Models, Animal; Neurodegenerative Diseases; Neuropsychological Tests; Time Factors