13 research outputs found
Sensorimotor cortex ablation induces time-dependent response of ACTH cells in adult rats: Behavioral, immunohistomorphometric and hormonal study
Traumatic brain injury (TBI) represents a serious event with far
reaching complications, including pituitary dysfunction. Pars distalis
corticotropes (ACTH cells), that represent the active module of
hypothalamo-pituitary-adrenocortical axis, seem to be affected as well.
Since pituitary failure after TBI has been associated with
neurobehavioral impairments the aim of this study was to evaluate the
effects of TBI on recovery of motor functions, morphology and secretory
activity of ACTH cells in the pituitary of adult rats. Wistar male rats,
initially exposed to sensorimotor cortex ablation (SCA), were sacrificed
at the 2nd, 7th, 14th and 30th days post-surgery (dps). A beam walking
test was used to evaluate the recovery of motor functions. Pituitary
glands and blood were collected for morphological and hormonal analyses.
During the first two weeks post-injury increased recovery of locomotor
function was detected, reaching almost the control value at day 30. SCA
induces significant increase of pituitary weights compared to their
time-matched controls. The volume of ACTH-immunopositive cells was
reduced at the 7th dps, while at the 14th dps their volume was enlarged,
in comparison to corresponding sham controls. Volume density of ACTH
cells was increased only at 14th dps, while at day 30 this increase was
insignificant. The plasma level of ACTH transiently increased after the
injury. The most pronounced changes were observed at the 7th and 14th
dps, and were followed by decrease toward control levels at the 30th
dps. Thus, temporal changes in the hypothalamic-pituitary-adrenal axis
after traumatic brain injury appear to correlate with the recovery
process. (C) 2013 Elsevier Inc. All rights reserved.Ministry of Education, Science and Technological Development of the
Republic of Serbia {[}III 41014, ON 173009
Effect of stab injury in the rat cerebral cortex on temporal pattern of expression of neuronal cytoskeletal proteins: An immunohistochemical study
Compelling evidence now points to the critical role of the cytoskeleton
in neurodegeneration. In the present study, using an immunohistochemical
approach, we have shown that cortical stab injury (CSI) in adult Wistar
rats significantly affects temporal pattern of expression of
neurofilament proteins (NFs). a major cytoskeleton components of
neurons, and microtubule-associated proteins (MAP2). At 3 days
post-injury (dpi) most of the NFs immunoreactivity was found in pyknotic
neurons and in fragmentized axonal processes in the perilesioned cortex.
These cytoskeletal alterations became more pronounced by 10 dpi. At the
subcellular level CSI also showed significant impact on NFs and MAP-2
expression. Thus, at 3 dpi most of the dendrites disappeared, while
large neuronal somata appeared like open circles pointing to membrane
disintegration. Conversely, at 10 dpi neuronal perikarya and a few new
apical dendrites were strongly labeled. Since aberrant NF
phosphorylation is a pathological hallmark of many human
neurodegenerative disorders, as well as is found after stressor stimuli,
the present results shed light into the expression of neurofilaments
after the stab brain injury. (C) 2014 Elsevier GmbH. All rights
reserved.Ministry of Education, Science and Technological Development of the
Republic of Serbia {[}III41014
Cortical Ablation Induces Time-Dependent Changes in Rat Pituitary Somatotrophs and Upregulates Growth Hormone Receptor Expression in the Injured Cortex
The pituitary appears to be vulnerable to brain trauma, and its
dysfunction is a common feature after traumatic brain injury. The role
of pituitary growth hormone (GH) in brain repair after injury has been
envisaged, but more studies must be performed to understand completely
the importance of GH in these processes. Because some of the
neuroprotective effects of GH are mediated directly through the GH
receptor (GHR), we examined GHR expression in the rat cerebral cortex
after sensorimotor cortex ablation. RT-PCR, immunohistochemistry, and
double immunofluorescence had been performed to analyze the correlation
between GHR expression in the injured cortex and activity of GH cells in
the pituitary. Our results showed that the volume of GH-immunopositive
cells was reduced at days 2 and 7 postsurgery (dps), and volume density
of GH cells was significantly decreased at 14 dps, all compared with
appropriate sham controls. At 30 dps all investigated parameters had
returned to control level. In the injured cortex, GHR expression was
transiently upregulated. Increased GHR immunoreactivity was observed in
reactive astrocytes at 7 and particularly at 14 dps. In neuronal cells,
an increase of GHR immunoreactivity was seen in neuronal cell bodies and
well-defined primary dendrites at 14 and especially at 30 dps. The
results presented here suggest that, during recovery from brain injury,
changes in activity of pituitary GH cells result in upregulation of GHR
that may have a role in neuronal arborization and glial proliferation in
the injured cortex. (C) 2014 Wiley Periodicals, Inc.Ministry of Education, Science, and Technological Development of the
Republic of Serbia {[}III 41014, ON 173009
Tiazofurin modulates lipopolysaccharide-activated microglia in vitro
Tiazofurin is a purine nucleoside analogue, with a broad spectrum of
antitumoral and anti-inflammatory properties. In the present study, we
have investigated the effect of tiazofurin on microglial inflammatory
response to lipopolysaccharide in vitro. The cytotoxic effect of the
drug was examined by sulforhodamine B assay. The Griess method was used
to quantify nitrite production. Microglial morphology was assessed by
measuring cell body size. Release of the pro-inflammatory cytokines,
tumor necrosis factor-alpha, interleukin-1 beta, interleukin-6, and the
anti-inflammatory cytokine interleukin-10, were evaluated by
enzyme-linked immunosorbent assay. Our data showed that tiazofurin
decreased the number of activated microglia, lowered nitric oxide
production and reduced the average cell surface of these cells.
Tiazofurin reduced tumor necrosis factor-alpha, interleukin-6 and
increased interleukin-10 secretion. Conversely, this drug promoted the
release of interleukin-1 beta. Results obtained in this study indicate
that TR displayed both anti-and pro-inflammatory modulation of activated
microglia that could be relevant for its antitumor action within the
central nervous system.Ministry of Education, Science and Technological Development, Republic
of Serbia {[}III41014
Ribavirin shows immunomodulatory effects on activated microglia
Ribavirin (RBV) is synthetic purine nucleoside analogue, licensed as
anti-viral drug that displays immunomodulatory actions on various immune
cells. Our previous ex vivo studies have demonstrated immunosuppressive
effects of RBV on reactive T-lymphocytes in experimental autoimmune
encephalomyelitis. Here, we examined the effects of RBV on inflammatory
response of microglia. RBV potency to down-regulate microglia
inflammatory response was assessed by measuring microglia cell body
size, and the production of nitric oxide (NO) and pro-and
anti-inflammatory cytokines. RBV exerted cytotoxic effects on
LPS-stimulated microglia, leaving non-stimulated microglia unaffected.
The exposure of activated microglia to RBV led to: decrease in the level
of NO as a result of decreased cell number, lower average cell surface,
the reduction of membrane ruffling, the suppression of interleukin-6
release and promoted interleukin-10 production. On the other hand, RBV
promoted LPS-induced interleukin-1 beta release. Our results imply that
RBV is a complex immunomodulator showing both anti-and pro-inflammatory
effects on activated microglia.Ministry of Education, Science and Technological Development of the
Republic of Serbia {[}III41014
Repetitive Hyperbaric Oxygenation Attenuates Reactive Astrogliosis and Suppresses Expression of Inflammatory Mediators in the Rat Model of Brain Injury
The exact mechanisms by which treatment with hyperbaric oxygen (HBOT) exerts its beneficial effects on recovery after brain injury are still unrevealed. Therefore, in this study we investigated the influence of repetitive HBOT on the reactive astrogliosis and expression of mediators of inflammation after cortical stab injury (CSI). CSI was performed on male Wistar rats, divided into control, sham, and lesioned groups with appropriate HBO. The HBOT protocol was as follows: 10 minutes of slow compression, 2.5 atmospheres absolute (ATA) for 60 minutes, and 10 minutes of slow decompression, once a day for 10 consecutive days. Data obtained using real-time polymerase chain reaction, Western blot, and immunohistochemical and immunofluorescence analyses revealed that repetitive HBOT applied after the CSI attenuates reactive astrogliosis and glial scarring, and reduces expression of GFAP (glial fibrillary acidic protein), vimentin, and ICAM-1 (intercellular adhesion molecule-1) both at gene and tissue levels. In addition, HBOT prevents expression of CD40 and its ligand CD40L on microglia, neutrophils, cortical neurons, and reactive astrocytes. Accordingly, repetitive HBOT, by prevention of glial scarring and limiting of expression of inflammatory mediators, supports formation of more permissive environment for repair and regeneration
Characteristics of novel myeloid precursor cell line, PC-MDS, established from a bone marrow of the patient with therapy-related myelodysplastic syndrome
We report on characteristics of the first human cell line, PC-MDS, derived from a bone marrow of a patient with therapy-related myelodysplastic syndrome (t-MDS) who had no overt post-MDS leukemia. Classic cytology analyses, immunophenotyping, cytogenetic and molecular genetic procedures were used for characterization of the cell line. PC-MDS cells are positive for the expression of CD13, CD15, CD30, CD33, and CD45 antigen. Positive cytochemical staining and immunophenotype analyses indicated that PC-MDS cells have some characteristics of the early myeloid precursor cell. The karyotype analysis of PC-MDS cell line revealed various numerical and structural changes including those typically associated with t-MDS: del(5)(q13)[7], der(5)t(5;11)(p11;q11)[13], -7[6], del(7)(q31)[2], +20[3], -20[4]. Evaluation of methylation status in a promoter region of p 15, p 16 and MGMT genes showed biallelic hypermethylation pattern of 5 promoter region only in MGMT gene. PC-MDS is the first t-MDS derived cell line, and based on its immunological, cytogenetic and molecular characterization could be a new tool in evaluation of complex biology of MDS and a model for methylation studies. (c) 2007 Elsevier Ltd. All rights reserved