Goo-Bo Jeong

Advanced glycation end-products produced systemically and by macrophages: A common contributor to inflammation and degenerative diseases.

ABSTRACT Advanced glycation end products (AGEs) and their receptor have been implicated in the progressions of many intractable diseases, such as diabetes and atherosclerosis, and are also critical for pathologic changes in chronic degenerative diseases, such as Alzheimers disease, Parkinsons disease, and alcoholic brain damage. Recently activated macrophages were found to be a source of AGEs, and the most abundant form of AGEs, AGE‐albumin excreted by macrophages has been implicated in these diseases and to act through common pathways. AGEs inhibition has been shown to prevent the pathogenesis of AGEs‐related diseases in human, and therapeutic advances have resulted in several agents that prevent their adverse effects. Recently, anti‐inflammatory molecules that inhibit AGEs have been shown to be good candidates for ameliorating diabetic complications as well as degenerative diseases. This review was undertaken to present, discuss, and clarify current understanding regarding AGEs formation in association with macrophages, different diseases, therapeutic and diagnostic strategy and links with RAGE inhibition.

Caffeine-induced endothelial cell death and the inhibition of angiogenesis

Numerous studies have shown that adenosine or adenosine agonists can stimulate angiogenesis. However, the effect of caffeine (a known adenosine receptor antagonist) on angiogenesis has not been previously studied. Accordingly, this study was undertaken to examine the effect of caffeine on angiogenesis and to clarify the mechanism involved. Chick chorioallantoic membrane assays were used to investigate the effect of caffeine on angiogenesis and proliferation assays using human umbilical vein endothelial cells (HUVECs), were used to study its effects on specific aspects of angiogenesis. The expressions of caspase-3 and Bcl-2 were examined by western blotting, immunofluorescence staining was used to identify HUVEC morphological changes, and fluorescence activated cell sorting (FACS) and DAPI staining were used to detect HUVEC apoptosis. Caffeine was found to inhibit blood vessel formation dose-dependently and to inhibit the proliferation of HUVECs time- and dose-dependently. FACS analysis and DAPI staining showed that inhibitory effect of caffeine on HUVEC proliferation was the result of apoptosis and the up-regulation of thrombospondin-1 (TSP-1). Furthermore, TSP-1 levels were down-regulated by NECA but were unaffected by CGS21680, indicating that caffeine regulated TSP-1 expression via adenosine A2B receptor. In addition, caffeine up-regulated caspase-3 and down-regulated Bcl-2 at the protein level. These results suggest that the inhibitory effect of caffeine on angiogenesis is associated, at least in part, with its induction of endothelial cell apoptosis, probably mediated by a caspase-3 dependent mechanism.

Recovery of CNS Pathway Innervating the Sciatic Nerve Following Transplantation of Human Neural Stem Cells in Rat Spinal Cord Injury

Stem cell research has been attained a greater attention in most fields of medicine due to its potential for many incurable diseases through replacing or helping the regeneration of damaged cells or tissues. Here, we demonstrated the functional recovery and structural connection of the central nervous system pathway innervating the sciatic nerve after total transection of the spinal cord followed by the transplantation of human neural stem cells (hNSC) in the injured rat spinal cord site. The limb function of hNSC-treated group recovered dramatically compared with that in the sham group by Basso–Beattie–Bresnahan (BBB) scores. Transplanted hNSC differentiated into astrocytes and neurons in the injured site. In addition, immunohistochemistry for growth-associated protein 43 showed axonal regeneration in the injured spinal cord site. The pseudorabies viral-Ba (PRV-Ba) tracing method revealed that transplanted hNSC and their differentiated neurons showed positive labeling after sciatic nerve injection. In addition, the PRV-Ba labeling was also observed in several nuclei in the brain innervating the sciatic nerve. This result implies that the rat CNS motor pathway could be reconstructed by hNSC transplantation, and it may contribute to the functional recovery of the limb.

Changes of calcium binding proteins, c-Fos and COX in hippocampal formation and cerebellum of Niemann–Pick, type C mouse

Niemann-Pick disease, type C (NPC) is an intractable disease that is accompanied by ataxia, dystonia, neurodegeneration, and dementia due to an NPC gene defect. Disruption of calcium homeostasis in neurons is important in patients with NPC. Thus, we used immunohistochemistry to assess the expression levels of calcium binding proteins (calbindin D28K, parvalbumin, and calretinin), c-Fos and cyclooxygenase-1,2 (COX-1,2) in the hippocampal formation and cerebellum of 4 and 8 week old NPC+/+, NPC+/-, and NPC-/- mice. General expression of these proteins decreased in the hippocampus and cerebellum of NPC-/- compared to that in both young and adult NPC+/+ or NPC+/- mice. Parvalbumin, COX-1,2 or c-Fos-immunoreactive neurons were widely detected in the CA1, CA3, and DG of the hippocampus, but the immunoreactivities were decreased sharply in all areas of hippocampus of NPC-/- compared to NPC+/+ and NPC+/- mice. Taken together, reduction of these proteins may be one of the strong phenotypes related to the neuronal degeneration in NPC-/- mice.

Quantitative proteomic analysis reveals that lipopolysaccharide induces mitogen-activated protein kinase-dependent activation in human microglial cells.

Microglial cells act as the first and main form of active immune defense in the central nervous system related to inflammation and neurodegenerative disease. Lipopolysaccharide (LPS) induces many genes encoding inflammatory mediators, including cytokines such as tumor necrosis factor‐α, interleukin‐1β, (IL‐1β), and IL‐6, chemokines, and prostaglandins in microglial cells. Quantitative proteomics methods with isobaric chemical labeling using tandem mass tags and 2D‐nano LC‐ESI‐MS/MS were used to systematically analyze proteomic changes in microglia responding to LPS stimulation. As a result, we found that the expression level of 21 proteins in human microglial cells changed after activation. Among those, one of the strong mitogen‐activated protein kinase (MAPK) regulator proteins, CMPK1 was highly upregulated after LPS stimulation in human microglial cells. We detected and validated upregulation of MAPK including ERK1/2, p38, and SAPK/JNK by immunohistochemistry and Western blotting. NFκB, strong transcription factor of CMPK1, was translocated to the nucleus from the cytosol by high contents screening after LPS stimulation. Taken together, we conclude that MAPK signaling plays an important role in LPS‐induced human microglial activation related to inflammatory response.

Activated microglial cells synthesize and secrete AGE-albumin

A holy grail of curing neurodegenerative diseases is to identify the main causes and mechanisms underlying neuronal death. Many studies have sought to identify these targets in a wide variety of ways, but a more important task is to identify critical molecular targets and their origins. Potential molecular targets include advanced glycation end products (AGEs) that can promote neuronal cell death, thereby contributing to neurodegenerative disorders such as Alzheimer disease or Parkinson disease. In this study, we showed that AGE-albumin (glycated albumin) is synthesized in microglial cells and secreted in the human brain. Our results provide new insight into which microglial cells can promote the receptor for AGE-mediated neuronal cell death, eventually leading to neurodegenerative diseases.

Alteration of the CNS pathway to the hippocampus in a mouse model of Niemann-Pick, type C disease.

Niemann-Pick type C disease (NPC) is an autosomal recessive disorder that results in premature death due to progressive neurodegeneration including dementia. To understand neuronal pathways connecting to the hippocampus, retrograde transneuronal labeling method with Bartha strain of pseudorabies virus (PRV) was employed in 40 NPC+/+, NPC+/- and NPC-/- mice. Immunohistochemistry using polyclonal antibody against PRV and streological counting were used. The number of neurons and synapse in CA2&3 regions of the hippocampus decreased dramatically in the NPC-/- mouse compared to the NPC+/+ or +/- mouse. The number of PRV positive cell was significantly decreased in several regions including the entorhinal and piriform cortex in the NPC-/- mouse. More severely, lateral septal dorsal nucleus, dorsal entorhinal cortex and medial geniculate body showed no positive labeling in the NPC-/- mouse. However, the hippocampus, medial septal and supramammilary nuclei showed increased immunoreactivity in the NPC-/- mouse. Our data suggest that the synaptic loss and discontinuity of the CNS hippocampal pathway may contribute to understanding the mechanism of symptoms and functional disabilities such as memory and learning disturbance in NPC patients.

Intravenously Infused F3.Olig2 Improves Memory Deficits via Restoring Myelination in the Aged Hippocampus following Experimental Ischemic Stroke

Oligodendrocytes play a crucial role in creating the myelin sheath that is an important component in neural transmission. In an animal model of transient cerebral ischemia, application of oligodendrocyte progenitor cells (OPCs) has not yet been reported. In this study, the effects of F3.Olig2 transplantation on memory and cognitive dysfunction were investigated in the aged gerbil in which ischemic stroke was induced. To investigate the possible mechanisms underlying repair, changes in the expression of myelin basic protein (MBP), oligodendrocyte-specific protein (OSP), and brain-derived neurotrophic factor (BDNF) were examined. Experimental ischemic stroke was induced by occlusion of bilateral common carotid arteries in aged gerbils. Gerbils (n = 31 per group) were randomly divided into three groups: (1) vehicle sham group, (2) vehicle ischemia group, and (3) F3.Olig2 ischemia group. After 1, 3, and 7 days of ischemia–reperfusion (I-R), saline or F3.Olig2 cells (1 × 10 6 cells in 100 μl) were injected into the gerbils intravenously. The gerbils were sacrificed 10 days after I-R for identification of grafted F3.Olig2 cells, and 15 and 30 days after I-R for tissue analysis after conducting passive avoidance and novel object recognition test. Injected F3.Olig2 cells and MBP, OSP, and BDNF were detected by specific antibodies using immunohistochemistry and/or Western blots. Memory and cognition were significantly increased in the F3.Olig2 ischemia group compared with the vehicle ischemia group. In the F3.Olig2 ischemia group, the neurons were not protected from ischemic damage; however, MBP, OSP, and BDNF expressions were significantly increased. Our results show that injection of F3.Olig2 cells significantly improved impaired memory and cognition, which might be related to increased MBP expression via increasing OSP and BDNF expression in the aged gerbil hippocampus following transient cerebral ischemia.

BDNF expression of macrophages and angiogenesis after myocardial infarction

mice exhibit impaired endothelial cell survival incoronaryarteriesandcapillaries,whereasBDNFoverexpressioninhearttissues increases capillary density [2]. Other studies have shownthat the exogenous delivery of BDNF to the ischemic heart improvesangiogenesis and left ventricular function [3,4]. BDNF concentrationwas found to be increased in blood after MI [4,5], but the source ofthis BDNF was not determined in the heart.After MI, resident and recruited macrophages remove necroticand apoptotic cells, secrete cytokines, and modulate angiogenesis [6].The induction of angiogenesis has been reported to be correlated withmacrophage numbers in various injury models [7]. It has also beenreported that macrophage activation depends on BDNF synthesisand/or TrkB expression[8,9]. However, whether BDNF plays a rolein regulating angiogenesis in myocardial infarction is still unclear.We hypothesized that BDNF secreted from macrophages inducesangiogenesis in MI hearts and determined the correlation betweenangiogenesis and BDNF expression of activated macrophages.MI was induced in adult male Sprague–Dawley rats weighing250–300 g (Harlan Laboratories, Seoul) by permanent ligation of theleft anterior descending coronary artery as previously described [10].The animal study was approved by the Gachon University IACUC. Therats with a successfully established model of MI were sacrificed atdays 1, 3, 5, and 7 (each n = 5). The sham surgery control groupwas regarded as the control (n = 5). Tissue sections of MI hearts atdays 1, 3, 5, and 7 showed the typical course of ventricular remodeling,beginningwiththelossofendothelialcellsandcardiomyocytes,follow-ed by accumulation of infiltrating cells and scar tissue formation. Morethan 90% of isolated cells showed a staining of macrophage markerCD68. This is in line with previously published results demonstratingthat monocytes have mainly differentiated into macrophages and arethe major inflammatory cell type during myocardial infarction.Then, we confirmed that the involvement of the activatedmacrophages in angiogenesis of MI hearts is BDNF-dependent. Wedraw this conclusion based upon several evidences. First, infiltratedmacrophages express BDNF during angiogenesis period in MI hearts.Immunohistochemical staining analysis showed that BDNF expressionof MI heart tissues increased transiently on 1 day after coronary arteryligation and then consistently decreased in line with cardiac celldeath. Meanwhile, BDNF positive infiltrating cells including macro-phages occurred on days 3, 5 and 7 in peri-infarct and infarct areas.In contrast, BDNF expression level was not changed in sham control(Fig. 1A). This phenomenon was confirmed in H9C2 cardiomyoblastcellculture.Hypoxiacondition(1%O

The Effect of Education in Anatomy using Cadavers to the Paramedic Students

There are insufficient cadaver-used practice programs for paramedic student education. To provide the basic data for the effective cadaver practice program, the study interviewed 255 students in department of EMT, who attended cadaver practicum. The results indicated that the average satisfaction level in education was 4.5 out of 5 and in relation to allotted time was 3.61 out of 5. The average understanding level of was 4.5 out of 5. In conclusion, senior students who have already taken clinical education & clinical procedure are recommended to focus on clinical anatomy practice and lower grade students are recommended to focus on understanding human body structure in cadaver-used practice program.