313 research outputs found
Inflammatory Responses Are Not Sufficient to Cause Delayed Neuronal Death in ATP-Induced Acute Brain Injury
BACKGROUND: Brain inflammation is accompanied by brain injury. However, it is controversial whether inflammatory responses are harmful or beneficial to neurons. Because many studies have been performed using cultured microglia and neurons, it has not been possible to assess the influence of multiple cell types and diverse factors that dynamically and continuously change in vivo. Furthermore, behavior of microglia and other inflammatory cells could have been overlooked since most studies have focused on neuronal death. Therefore, it is essential to analyze the precise roles of microglia and brain inflammation in the injured brain, and determine their contribution to neuronal damage in vivo from the onset of injury. METHODS AND FINDINGS: Acute neuronal damage was induced by stereotaxic injection of ATP into the substantia nigra pars compacta (SNpc) and the cortex of the rat brain. Inflammatory responses and their effects on neuronal damage were investigated by immunohistochemistry, electron microscopy, quantitative RT-PCR, and stereological counting, etc. ATP acutely caused death of microglia as well as neurons in a similar area within 3 h. We defined as the core region the area where both TH(+) and Iba-1(+) cells acutely died, and as the penumbra the area surrounding the core where Iba-1(+) cells showed activated morphology. In the penumbra region, morphologically activated microglia arranged around the injury sites. Monocytes filled the damaged core after neurons and microglia died. Interestingly, neither activated microglia nor monocytes expressed iNOS, a major neurotoxic inflammatory mediator. Monocytes rather expressed CD68, a marker of phagocytic activity. Importantly, the total number of dopaminergic neurons in the SNpc at 3 h (∼80% of that in the contralateral side) did not decrease further at 7 d. Similarly, in the cortex, ATP-induced neuron-damage area detected at 3 h did not increase for up to 7 d. CONCLUSIONS: Different cellular components (microglia, astrocytes, monocytes, and neutrophils) and different factors (proinflammatory and neurotrophic) could be produced in inflammatory processes depending on the nature of the injury. The results in this study suggest that the inflammatory responses of microglia and monocytes in response to ATP-induced acute injury could not be neurotoxic
CD4+ T cells from MHC II-dependent thymocyte–thymocyte interaction provide efficient help for B cells
Recently, a novel CD4+ T-cell developmental pathway was reported that generates thymocyte–thymocyte (T–T) CD4+ T cells. We established a mouse system (CIITAtgCIITApIV−/−) where thymic positive selection occurred only by major histocompatibility complex (MHC) class II+ thymocytes. T–T CD4+ T cells selected via MHC class II-dependent T–T interaction are comprised of PLZF-negative and innate PLZF-positive populations. Until recently, the functional role of the PLZF-negative population was unclear. In this study, we demonstrate that naïve T–T CD4+ T cells provide B-cell help to a level comparable with that of naïve conventional CD4+ T cells. Considering the absence of PLZF expression in naïve T–T CD4+ T cells, these results suggest that PLZF-negative naïve T–T CD4+ T cells are functionally equivalent to conventional naïve CD4+ T cells in terms of B-cell help
Cooperative roles of the suprachiasmatic nucleus central clock and the adrenal clock in controlling circadian glucocorticoid rhythm
The mammalian circadian timing system consists of the central clock in the hypothalamic suprachiasmatic nucleus (SCN) and subsidiary peripheral clocks in other tissues. Glucocorticoids (GCs) are adrenal steroid hormones with widespread physiological effects that undergo daily oscillations. We previously demonstrated that the adrenal peripheral clock plays a pivotal role in circadian GC rhythm by driving cyclic GC biosynthesis. Here, we show that the daily rhythm in circulating GC levels is controlled by bimodal actions of central and adrenal clockwork. When mice were subjected to daytime restricted feeding to uncouple central and peripheral rhythms, adrenal GC contents and steroidogenic acute regulatory protein expression peaked around zeitgeber time 00 (ZT00), consistent with shifted adrenal clock gene expression. However, restricted feeding produced two distinct peaks in plasma GC levels: one related to adrenal GC content and the other around ZT12, which required an intact SCN. Light pulse-evoked activation of the SCN increased circulating GC levels in both wild-type and adrenal clock-disrupted mutant mice without marked induction of GC biosynthesis. In conclusion, we demonstrate that adrenal clock-dependent steroidogenesis and a SCN-driven central mechanism regulating GC release cooperate to produce daily circulatory GC rhythm. © The Author(s) 2017.1
Short-term calorie restriction ameliorates genomewide, age-related alterations in DNA methylation
DNA methylation plays major roles in many biological processes, including aging, carcinogenesis, and development. Analyses of DNA methylation using next-generation sequencing offer a new way to profile and compare methylomes across the genome in the context of aging. We explored genomewide DNA methylation and the effects of short-term calorie restriction (CR) on the methylome of aged rat kidney. Whole-genome methylation of kidney in young (6 months old), old (25 months old), and OCR (old with 4-week, short-term CR) rats was analyzed by methylated DNA immunoprecipitation and next-generation sequencing (MeDIP-Seq). CpG islands and repetitive regions were hypomethylated, but 5'-UTR, exon, and 3'-UTR hypermethylated in old and OCR rats. The methylation in the promoter and intron regions was decreased in old rats, but increased in OCR rats. Pathway enrichment analysis showed that the hypermethylated promoters in old rats were associated with degenerative phenotypes such as cancer and diabetes. The hypomethylated promoters in old rats related significantly to the chemokine signaling pathway. However, the pathways significantly enriched in old rats were not observed from the differentially methylated promoters in OCR rats. Thus, these findings suggest that short-term CR could partially ameliorate age-related methylation changes in promoters in old rats. From the epigenomic data, we propose that the hypermethylation found in the promoter regions of disease-related genes during aging may indicate increases in susceptibility to age-related diseases. Therefore, the CR-induced epigenetic changes that ameliorate age-dependent aberrant methylation may be important to CR's health-and life-prolonging effects.ope
DEL 적혈구에 의한 항-D 동종면역
Extremely weak D variants called DEL are serologically detectable only by adsorption-elution techniques. A nucleotide change of exon 9 in RHD gene, RHD (K409K, 1227G>A) allelic variant is present in almost all the DEL individuals of East Asians. No DEL phenotype has yet been shown to induce a primary alloanti-D immunization in East Asia. A 68-yr-old D-negative Korean man was negative for anti-D at admission, and he developed alloanti-D after transfusion of red blood cells (RBC) from 4 apparently D-negative donors. Four donors who typed D-negative by routine serologic test were analyzed by real-time PCR for RHD gene and RHD (K409K). One donor was found to have RHD (K409K), This is the first case in which DEL RBCs with RHD (K409K) induced a primary alloanti-D immunization in Asian population. Because the DEL phenotype can induce an anti-D immunization in D-negative recipients, further discussion is needed whether RhD negative donors should be screened by molecular method and what an efficient genotyping method is for detecting the RHD gene carriers in Korea. (Korean J Lab Med 2009;29:361-5)Polin H, 2009, TRANSFUSION, V49, P676, DOI 10.1111/j.1537-2995.2008.02046.xFlegel WA, 2009, TRANSFUSION, V49, P465, DOI 10.1111/j.1537-2995.2008.01975.xSun CF, 2008, ANN CLIN LAB SCI, V38, P258Richard M, 2007, TRANSFUSION, V47, P852, DOI 10.1111/j.1537-2995.2007.01199.xLuettringhaus TA, 2006, TRANSFUSION, V46, P2128, DOI 10.1111/j.1537-2995.2006.01042.xYasuda H, 2005, TRANSFUSION, V45, P1581, DOI 10.1111/j.1537-2995.2005.00579.xWagner T, 2005, TRANSFUSION, V45, P520Gassner C, 2005, TRANSFUSION, V45, P527Kim JY, 2005, TRANSFUSION, V45, P345WAGNER FF, 2001, BMC GENET, V2, P10Avent ND, 2000, BLOOD, V95, P375Aubin JT, 1997, BRIT J HAEMATOL, V98, P356Okuda H, 1997, J CLIN INVEST, V100, P373Avent ND, 1997, BLOOD, V89, P2568HWANG YS, 1996, KOREAN J BLOOD TRANS, V7, P233DANIELS G, 1995, HUMAN BLOOD GROUPSMAK KH, 1993, TRANSFUSION, V33, P348LINCHU M, 1988, TRANSFUSION, V28, P350
Effect of ankle taping on the ankle muscle strength in young healthy women
Of the various approaches to manage or prevent injuries on the ankle joint, Kinesio taping improves static posture stability, stimulating the neuromuscular control system. This study aims to investigate of ankle taping on the peak torque and average power of ankle muscle in young heathy women. Taping was applied to the extensor digitorum, tibialis anterior, gastrocnemius, soleus of the ankle in 16 healthy women. Isokinetic measurement of the dorsiflexion and plantarflexion patterns were recorded before and after taping. As a result of this study, the pre-post isokinetic parameters improved significantly for plantarflexion (p<0.05) while those for dorsiflexion did not. Through this study, it was found out that ankle taping improved the muscle power of the plantarflexor of young healthy women, and it is expected that applying ankle taping would help young healthy women
Disease Prevalence and Mortality among Agricultural Workers in Korea
The aim of this paper was to provide an overview of mortality and disease prevalence related to occupational diseases among agricultural workers in Korea. We evaluated the age-standardized mortality rates and the prevalence of chronic diseases and compared them with those of other populations using death registration data from 2004 through 2008 and the 2005 Korean National Health and Nutrition Examination Survey. In addition, we conducted a literature review on published articles examining the health status of farmers in Korea. Agricultural workers have a significantly higher mortality of cancer, tuberculosis, chronic respiratory diseases, liver diseases, suicide, motor and non-motor vehicle accidents. Compared to other populations, farmers have higher prevalence rates of arthritis and intervertebral disc disorders. The literature review revealed a number of work-related diseases among farmers, such as musculoskeletal diseases, pesticide poisoning, infections, and respiratory and neurologic diseases. Korean farmers demonstrate a distinct pattern of mortality and disease prevalence compared to other populations. Although lifestyle factors remain important contributors to those deaths and diseases, our study suggests that occupation is a major determinant as well. Intensive programs such as surveillance systems, therefore, should be developed in order to identify and prevent work-related diseases among agricultural workers in Korea
Reactive oxygen species and p47phox activation are essential for the Mycobacterium tuberculosis-induced pro-inflammatory response in murine microglia
<p>Abstract</p> <p>Background</p> <p>Activated microglia elicits a robust amount of pro-inflammatory cytokines, which are implicated in the pathogenesis of tuberculosis in the central nervous system (CNS). However, little is known about the intracellular signaling mechanisms governing these inflammatory responses in microglia in response to <it>Mycobacterium tuberculosis </it>(Mtb).</p> <p>Methods</p> <p>Murine microglial BV-2 cells and primary mixed glial cells were stimulated with sonicated Mtb (s-Mtb). Intracellular ROS levels were measured by staining with oxidative fluorescent dyes [2',7'-Dichlorodihydrofluorescein diacetate (H<sub>2</sub>DCFDA) and dihydroethidium (DHE)]. NADPH oxidase activities were measured by lucigenin chemiluminescence assay. S-Mtb-induced MAPK activation and pro-inflammatory cytokine release in microglial cells were measured using by Western blot analysis and enzyme-linked immunosorbent assay, respectively.</p> <p>Results</p> <p>We demonstrate that s-Mtb promotes the up-regulation of reactive oxygen species (ROS) and the rapid activation of mitogen-activated protein kinases (MAPKs), including p38 and extracellular signal-regulated kinase (ERK) 1/2, as well as the secretion of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-12p40 in murine microglial BV-2 cells and primary mixed glial cells. Both NADPH oxidase and mitochondrial electron transfer chain subunit I play an indispensable role in s-Mtb-induced MAPK activation and pro-inflammatory cytokine production in BV-2 cells and mixed glial cells. Furthermore, the activation of cytosolic NADPH oxidase p47phox and MAPKs (p38 and ERK1/2) is mutually dependent on s-Mtb-induced inflammatory signaling in murine microglia. Neither TLR2 nor dectin-1 was involved in s-Mtb-induced inflammatory responses in murine microglia.</p> <p>Conclusion</p> <p>These data collectively demonstrate that s-Mtb actively induces the pro-inflammatory response in microglia through NADPH oxidase-dependent ROS generation, although the specific pattern-recognition receptors involved in these responses remain to be identified.</p
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