PBS-treated Rats Research Articles

Ioversol Induced Microglia Proinflammatory Activation and Oxidative Stress in Rats.

Contrast-induced encephalopathy (CIE) following angiography, though not often and reversible, can in some cases lead to permanent neurological dysfunction. To identify how neuroinflammation is involved in CIE, we investigated microglia responses to a bolus injection of ioversol in the internal carotid artery (ICA) in rats. MicroCT scanning indicated that the injected ioversol was cleared from the rat's brain within 25 min. However, proinflammatory activated and significantly increased microglia were found in the rat occipital cortex at 1 day, and the number of blood vessel-associated microglia was still significantly higher at 3-day post-injection, compared with sham- and PBS-treated rats. Moreover, significantly upregulated malondialdehyde (MDA), downregulated superoxide dismutase (SOD) levels, and elevated proinflammatory cytokines were observed in the brain of rats treated with ioversol. Ioversol administration decreased cell viability of primarily cultured microglia and induced significant proinflammatory activation. Furthermore, ioversol remarkably upregulated astrocytic aquaporin (AQP) 4 expression in the rats brain, and transwell cultures showed significantly enhanced microglia migrating to ioversol-treated endothelial cells. Immediate injection of edaravone dexborneol, a novel antioxidative drug, after ioversol injection effectively rescued ioversol-induced neuroinflammation. Together, these findings suggest that ioversol induced neuroinflammation and oxidative stress in the brain via microglia activation in a direct and indirect manner, which might contribute to the pathogenesis of CIE.

Oxytocin-conjugated saporin injected into the substantia nigra of male rats alters the activity of the nigrostriatal dopaminergic system: A behavioral and neurochemical study

Saporin conjugated to oxytocin (OXY-SAP) destroys neurons expressing oxytocinergic receptors. When injected unilaterally in the substantia nigra of male rats, OXY-SAP causes a dose-dependent decrease up to 55 % in nigral Tyrosine Hydroxylase (TH)-immunoreactivity compared to control mock peptide BLANK-SAP- and PBS-treated rats or the contralateral substantia nigra. TH decrease was parallel to a dopamine content decrease in the ipsilateral striatum compared to BLANK-SAP- or PBS-treated rats or the contralateral striatum. OXY-SAP-treated rats showed a small but significant increase of locomotor activity 28 days after intranigral injection in the Open field test compared to BLANK-SAP- or PBS-treated rats, in line with an inhibitory role of nigral oxytocin on locomotor activity. OXY-SAP-, but not BLANK-SAP- or PBS-treated rats, also showed marked dose-dependent rotational turning ipsilateral to the injected substantia nigra when challenged with d-amphetamine, but not with apomorphine. Under isoflurane anesthesia OXY-SAP-treated rats showed levels of extracellular dopamine in the dialysate from the ipsilateral striatum only half those of BLANK-SAP- or PBS-treated rats or the contralateral striatum. When treated with d-amphetamine, OXY-SAP_60/120 rats showed increased extracellular dopamine levels in the dialysate from the ipsilateral striatum two third/one third only of those found in BLANK-SAP- or PBS-treated rats or the contralateral striatum, respectively. These results show that OXY-SAP destroys nigrostriatal dopaminergic neurons expressing oxytocin receptors leading to a reduced striatal dopamine function.

Natural Vascular Scaffolding Treatment Promotes Outward Remodeling During Arteriovenous Fistula Development in Rats.

Following creation, an arteriovenous fistula (AVF) must mature (i.e., enlarge lumen to allow high blood flow) before being used for hemodialysis. AVF maturation failure rates are high, and currently, there are no effective therapy to treat this problem. The maturation process is likely affected by the integrity of the vascular extracellular matrix (ECM). Natural Vascular Scaffolding (NVS) Therapy is a new technology that interlinks collagen and elastin via photoactivation of a locally delivered small molecule (4-amino-1,8-naphtalamide). We hypothesized that NVS Therapy may improve AVF remodeling by preserving ECM integrity. AVFs were created in Wistar male rats by connecting the femoral vein (end) to femoral artery (side) in the same limb. Immediately after blood flow was restored to dilate the femoral vein by arterial pressure, a 10 μl-drop of the NVS compound (2 mg/ml) was placed on the anastomosis perivascularly. Following 5-min incubation, the NVS treated area was exposed to 1-min illumination by 450-nm light. The control group received 10 μl-drop of phosphate buffered saline (PBS) and the same light activation. The skin was closed, and rats were euthanized 4 weeks (n = 6–9 per group) post-AVF creation for histology, morphometry, immunohistochemistry (IHC), and multiphoton microscopy for second-harmonic-generation evaluation of collagen fibers. The vascular thickness was similar in both groups. The AVF vein’s open lumen area and % open lumen area in NVS-treated rats were significantly larger than in PBS-treated rats (4.2-fold p = 0.014 and 2-fold p = 0.009, respectively). The inflammatory markers IL-6 and MMP-9 in the AVF walls were significantly decreased in the NVS group than the PBS group. Collagen fibers in the vascular wall trended toward perpendicular alignment to the lumen circumference in the NVS-treated AVFs, with more defined shape but less area than in the PBS-treated AVFs. These results indicate that the NVS Therapy exerted changes in collagen, which may influence AVF maturation. Rats tolerated the NVS treatment well, and the lack of cell death by the treatment was confirmed in cell culture experiments. These results suggest that NVS treatment is safe and may have therapeutic potential by facilitating lumen expansion to enhanced AVF maturation in patients.

The tellurium-based immunomodulator, AS101 ameliorates adjuvant-induced arthritis in rats.

Despite undeniable improvement in the management of rheumatoid arthritis (RA), the discovery of more effective, less toxic and, ideally, less immune suppressive drugs are much needed. In the current study, we set to explore the potential anti-rheumatic activity of the non-toxic, tellurium-based immunomodulator, AS101 in an experimental animal model of RA. The effect of AS101 was assessed on adjuvant-induced arthritis (AIA) rats. Clinical signs of arthritis were assessed. Histopathological examination was used to assess inflammation, synovial changes and tissue lesions. Very late antigen-4 (VLA-4)+ cellular infiltration was detected using immunohistochemical staining. Enzyme-linked immunosorbent assay (ELISA) was used to measure circulating anti-cyclic citrullinated-peptide autoantibody (ACPA) and real-time polymerase chain reaction (PCR) was used to measure the in-vitro effect of AS101 on interleukin (IL)-6 and IL-1β expression in activated primary human fibroblasts. Prophylactic treatment with intraperitoneal AS101 reduced clinical arthritis scores in AIA rats (P<0·01). AS101 abrogated the migration of active chronic inflammatory immune cells, particularly VLA-4+ cells, into joint cartilage and synovium, reduced the extent of joint damage and preserved joint architecture. Compared to phosphate-buffered saline (PBS)-treated AIA rats, histopathological inflammatory scores were significantly reduced (P<0·05). Furthermore, AS101 resulted in a marked reduction of circulating ACPA in comparison to PBS-treated rats (P<0·05). Importantly, AS101 significantly reduced mRNA levels of proinflammatory mediators such as IL-6 (P<0·05) and IL-1β (P<0·01) in activated primary human fibroblasts. Taken together, we report the first demonstration of the anti-rheumatic/inflammatory activity of AS101 in experimental RA model, thereby supporting an alternative early therapeutic intervention and identifying a promising agent for therapeutic intervention.

Activation of Nrf2 by lead sulfide nanoparticles induces impairment of learning and memory.

Lead sulfide nanoparticles (PbS NPs) are semiconductor materials that have been widely applied to light-emitting diodes (LEDs), biological fluorescent probes, infrared detection, solar receivers, ion-selective electrodes, and ion-sensitive materials. However, the effects of PbS NPs on the central nervous system are still unclear. Thus, this study aimed to determine, using rats, the mechanism of action of PbS NPs, exposure to which results in persistent alterations in nervous system function. The results of the Morris water maze test showed that PbS NPs significantly impaired learning and memory. Compared with that in the control group, the lead content in the hippocampal tissue was significantly elevated after PbS NP exposure. Exposure to PbS NPs led to increased oxidative damage in blood and hippocampal tissues, and significantly inhibited the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) while increasing the serum malondialdehyde (MDA) content. In addition, reactive oxygen species triggered the activation of Nrf2 and the antioxidant system, including HO-1, r-GCS, and GSH-Px. Moreover, we observed significant apoptosis in the hippocampi of the rats using the TUNEL assay and transmission electron microscopy. The MOD values from the TUNEL assay of the hippocampi were all significantly higher than those of the control group, which increased as the concentration of the PbS NPs increased. There were also changes in the ultrastructure of the hippocampal neurons and synapses in the PbS-treated rats, including a shorter synaptic active zone, smaller curvature of the synaptic interface, and thicker postsynaptic density. Therefore, PbS NP exposure could lead to increased brain lead content, oxidative damage, and apoptosis.

Diabetes Promotes Development of Alzheimer's Disease Through Suppression of Autophagy.

Recent studies suggest that diabetes predisposes patients to develop neurodegenerative Alzheimer's disease (AD), although the underlying mechanisms have yet to be determined. Compromised autophagy of neuronal cells, which occurs in the early stages of AD, has been shown to enhance disease progression. However, autophagic regulation as a mechanism connecting diabetes and AD has not been shown before. Here, we found that streptozotocin (STZ)-induced diabetic rats exhibited poorer performance on the social recognition test, Morris water maze, and plus-maze discriminative avoidance task, compared to PBS-treated normoglycemic control rats, likely resulting from increased brain deposition of amyloid-β peptide aggregates (Aβ) and increased phosphorylation of tau protein, two pathological features of AD. Moreover, diabetes-induced AD-like behavioral and pathological changes were associated with a decrease in neuronal cell autophagy. Furthermore, compromised cell autophagy was recapitulated in vitro in neuronal cells cultured in high glucose conditions. Thus, our data suggest that hyperglycemia in diabetes may directly inhibit neuronal cell autophagy, which subsequently enhances AD-associated pathological progression.

Angiopoietin-1 Mimetic Peptide Promotes Neuroprotection after Stroke in Type 1 Diabetic Rats

Angiopoietin-1 (Ang1) mediates vascular maturation and immune response. Diabetes decreases Ang1 expression and disrupts Ang1/Tie2 signaling activity. Vasculotide is an Ang1 mimetic peptide, and has anti-inflammatory effects. In this study, we test the hypothesis that vasculotide treatment induces neuroprotection and decreases inflammation after stroke in type 1 diabetic (T1DM) rats. T1DM rats were subjected to embolic middle cerebral artery occlusion (MCAo) and treated with: 1) phosphate buffered saline (PBS); 2) vasculotide (3µg/kg, i.p. injection) administered half an hour prior to MCAo and at 8 and 24 hours after MCAo. Rats were sacrificed at 48 h after MCAo. Neurological function, infarct volume, hemorrhage, blood brain barrier (BBB) permeability and neuroinflammation were measured. Vasculotide treatment of T1DM-MCAo rats significantly improves functional outcome, decreases infarct volume and BBB permeability, but does not decrease brain hemorrhagic transformation compared with PBS-treated T1DM-MCAo rats. In the ischemic brain, Vasculotide treatment significantly decreases apoptosis, number of cleaved-caspase-3 positive cells, the expression of monocyte chemotactic protein-1 (MCP-1) and tumor necrosis factor (TNF-α). Western blot analysis shows that vasculotide significantly decreases expression of receptor for advanced glycation end products (RAGE), MCP-1 and TNF-α in the ischemic brain compared with T1DM-MCAo rats. Vasculotide treatment in cultured primary cortical neurons (PCN) significantly decreases TLR4 expression compared with control. Decreased neuroinflammation and reduced BBB leakage may contribute, at least in part, to vasculotide-induced neuroprotective effects after stroke in T1DM rats.

2235 15N-Leucine transport across the blood brain barrier is significantly impaired in the glutamine synthetase-inhibited brain

OBJECTIVES/SPECIFIC AIMS: Astroglial glutamine synthetase (GS), which metabolizes glutamate and ammonia to glutamine, is critical for the detoxification of brain ammonia, clearance of synaptic glutamate, and production of brain glutamine. Perturbations in the expression and activity of GS are thought to play a causative role in the pathogenesis of several conditions of abnormal neurotransmission. Although the long-term consequences of GS inhibition on amino acid homeostasis in the brain are unknown, it is thought that amino acid influx in the brain is tightly coupled with glutamine efflux via the L-type amino acid transporter. Both glutamine and leucine serve many critical functions in the brain including protein synthesis, gene expression, insulin regulation, and immune signaling. The objective of this study was to determine the effects of chronic GS inhibition with methionine sulfoximine (MSO) on glutamine and leucine homeostasis in the brain. METHODS/STUDY POPULATION: In total, 12 rats were surgically implanted with microdialysis guide cannulas in the bilateral dentate gyrus. Rats were randomly divided for surgical implantation of either a MSO (n=6) or phosphate buffer saline (PBS; n=6) pump in the right dentate gyrus. After 7 days, bilateral microdialysis probes were placed under brief isoflurane anesthesia, and microdialysis flow was established by infusing 0.5 µL/min of artificial extracellular fluid. Dialysate samples were collected every 30 minutes for the duration of the experiment. A 113 mM 15N-Leucine (3.6 mL/h) and 2 M 2–13C-sodium acetate (0.0633 μL/g/min for t=0–5 min, 0.0316 μL/g/min for t=5–10 min, and 0.0253 μL/g/min for t&gt;10 min) solution was infused intravenously for 300 minutes. The EZ:Faast Free Amino Acid analysis kit and ultra-performance liquid chromatography/tandem mass spectrometry was used for quantification of amino acids in the dialysate fluid. RESULTS/ANTICIPATED RESULTS: At baseline (t=0 h), the concentrations of glutamine were significantly lower in MSO-treated rats (p&lt;0.001) in the ipsilateral (GS-inhibited) hippocampus. There were no differences in glutamine concentrations between MSO and PBS-treated rats in the contralateral hippocampus. In PBS-treated rats, there was a significant increase in 15N-leucine between t=0 hour and t=5 hour in the contralateral (p&lt;0.05) and ipsilateral (p&lt;0.05) hippocampus. In MSO-treated rats, there was a significant increase in 15N-leucine between t=0 and t=5 hours in the contralateral (p&lt;0.05) hippocampus, but not in the ipsilateral hippocampus (p=ns.). DISCUSSION/SIGNIFICANCE OF IMPACT: This study demonstrated for the first time that basal glutamine concentrations are low in areas of the brain where GS is acutely inhibited, and that leucine uptake in these brain areas are markedly decreased. Perturbations in glutamine and leucine homeostasis have been implicated in several disease processes including diabetes, obesity, liver disease, immune system dysfunction, epilepsy, and cancer, and the glutamine-dependent leucine influx in the brain may be a novel and important therapeutic target to treat these conditions.

Abstract WMP77: Anti-Inflammatory Signaling by Leukemia Inhibitory Factor is Suppressed in Aged Animals After Stroke

Objective: To determine whether the anti-inflammatory effects of leukemia inhibitory factor (LIF) are altered in aged male and female rats. Methods: Focal ischemia was induced in 3 month old male and 18 month old male/female Sprague-Dawley using the middle cerebral artery occlusion (MCAO) procedure. Animals were treated with PBS or LIF at 6, 24, and 48 h after MCAO (125 μg/kg). Infarct volume in aged animals was quantified with T2-weighted MRI. Functional motor skills were assessed immediately prior to euthanization at 72 h post-MCAO. Protein levels of CD11b and IL-12 p40 in brain and spleen tissue were measured using immunoblotting. Results: At 72 h, there was a trend towards decreased infarct volume in aged male (189 ± 45OD; n=4) and female LIF-treated rats (104 ± 71 OD; n=4) compared to PBS-treated aged male (188 ± 45; n=4) and female rats (179 ± 72; n=5). LIF-treated aged female rats showed significant decreases in circling (p=0.0209) and body swing bias (p=0.05) compared to the PBS-treated aged females. Normalized CD11b levels were significantly in LIF-treated young males (1.1 ± 0.3 OD; n=5) compared to PBS-treated young males (2.5 ± 0.5 OD; n=6; p&lt;0.05). Although aged male (1.2 ± 0.4 OD) and females (1.2 ± 0.3 OD) had lower levels of CD11b in the brain 72 h post-MCAO compared to young males, LIF had no effect on brain CD11b levels in aged rats. LIF increased spleen size (1.6 ± 0.1 g) and splenic CD11b levels (0.11 ± 0.01 OD) compared to PBS-treated females (0.6 ± 0.1 g; 0.08 ± 0.01 OD; p&lt;0.05), and there was a significant positive correlation between these two factors in the aged female rats (r = 0.6775; p&lt;0.05). Furthermore, IL-12 p40 levels in splenic tissue were significantly higher in young male PBS-treated rats (0.38 ± 0.06 OD) compared to aged male (0.12 ± 0.01 OD; p&lt;0.01) and female rats (0.16 ± 0.04 OD; p&lt;0.01). LIF treatment reduced IL-12 p40 levels in the spleen in young rats (0.24 ± 0.04; p&lt;0.05) but not in either of the aged rat groups. Conclusions: LIF is more effective at decreasing splenic IL-12 expression and immune cell infiltration in young rats compared to aged rats. However, LIF counteracts the post-stroke splenic response in aged females but not aged male rats.

Role of medullary astroglial glutamine synthesis in tooth pulp hypersensitivity associated with frequent masseter muscle contraction.

BackgroundThe mechanisms underlying tooth pulp hypersensitivity associated with masseter muscle hyperalgesia remain largely underinvestigated. In the present study, we aimed to determine whether masseter muscle contraction induced by daily electrical stimulation influences the mechanical head-withdrawal threshold and genioglossus electromyography activity caused by the application of capsaicin to the upper first molar tooth pulp. We further investigated whether astroglial glutamine synthesis is involved in first molar tooth pulp hypersensitivity associated with masseter muscle contraction.MethodsThe first molar tooth pulp was treated with capsaicin or vehicle in masseter muscle contraction or sham rats, following which the astroglial glutamine synthetase inhibitor methionine sulfoximine or Phosphate buffered saline (PBS) was applied. Astroglial activation was assessed via immunohistochemistry.ResultsThe mechanical head-withdrawal threshold of the ipsilateral masseter muscle was significantly decreased in masseter muscle contraction rats than in sham rats. Genioglossus electromyography activity was significantly higher in masseter muscle contraction rats than sham rats. Glial fibrillary acidic protein-immunoreactive cell density was significantly higher in masseter muscle contraction rats than in sham rats. Administration of methionine sulfoximine induced no significant changes in the density of glial fibrillary acidic protein-immunoreactive cells relative to PBS treatment. However, mechanical head-withdrawal threshold was significantly higher in masseter muscle contraction rats than PBS-treated rats after methionine sulfoximine administration. Genioglossus electromyography activity following first molar tooth pulp capsaicin treatment was significantly lower in methionine sulfoximine-treated rats than in PBS-treated rats. In the ipsilateral region, the total number of phosphorylated extracellular signal-regulated protein kinase immunoreactive cells in the medullary dorsal horn was significantly smaller upon first molar tooth pulp capsaicin application in methionine sulfoximine-treated rats than in PBS-treated rats.ConclusionsOur results suggest that masseter muscle contraction induces astroglial activation, and that this activation spreads from caudal to the obex in the medullary dorsal horn, resulting in enhanced neuronal excitability associated with astroglial glutamine synthesis in medullary dorsal horn neurons receiving inputs from the tooth pulp. These findings provide significant insight into the mechanisms underlying tooth pulp hypersensitivity associated with masseter muscle contraction.

Effect of partial depletion of CD25+ T cells on neurological deficit and tissue damage in acute cerebral ischemia rat models

Objective: To evaluate the role of regulatory T cells (Tregs) at late stages of stroke. Methods: Anti-CD25 antibody (or PBS as a control) was injected to reduce the pool of Tregs in Wistar rats; then, ischemia was induced transiently by middle cerebral artery occlusion during 60 min and reperfusion was allowed for 7 d. Then, Treg frequency was analyzed in peripheral blood, spleen and lymph nodes. Neurological score (0-6) and infarct volume were also determined. Results: Nine days after injection, the CD4+CD25+ T cells were reduced by 70.4%, 44.8% and 57.9% in peripheral blood, spleen and lymph nodes, respectively compared to PBS-treated rats. In contrast, the reduction of CD4+FOXP3+ T cells was lower in the same compartments (38.6%, 12.5%, and 29.5%, respectively). The strongest reduction of CD25+CD4+ T cells was observed in those FOXP3-negative cells in blood, spleen and lymph nodes (77.8%, 52.8%, and 60.7%, respectively), most likely corresponding to activated T cells. Anti-CD25-treated transient middle cerebral artery occlusion rats had a lower neurological deficit and did not develop tissue damage compared with PBS-treated animals. Conclusions: These findings suggest that treatment with anti-CD25 in our model preferentially reduce the T cell population with an activated phenotype, rather than the Treg population, leading to neuroprotection by suppressing the pathogenic response of effector T cells.

Corticosteroid therapy exacerbates the reduction of melatonin in multiple sclerosis

ObjectivesCorticosteroid therapy is employed in multiple sclerosis (MS), a neurological abnormality characterized by an inflammatory process. Melatonin, a potent sleep-promoting and circadian phase regulatory hormone, is produced mainly in the pineal gland whose inhibition leads to sleep disturbances. MethodsIn this study, methylprednisolone (MP) corticosteroid treatment was used in an acute experimental autoimmune encephalomyelitis (EAE) rat model (intraperitoneal, 30 mg/kg) and in MS patients (intravenous, 1000 mg/day), followed by assessing melatonin serum levels. Key findingsResults showed that mean clinical scores were significantly improved in MP- versus PBS-treated EAE rats (1.5 vs 4.1, respectively). In addition, MP was found to induce a significant decrease in serum IFN-γ, whereas IL-4 levels were significantly increased, in comparison to PBS-treated EAE rats. The ratio of IFN-γ/IL-4, which acts as an indicator of Th-1/Th-2, was significantly lower in MP treated, compared to PBS treated EAE rats or controls. Moreover, serum levels of melatonin showed a significant decrease in the MP group, compared to normal rats. Moreover, MP therapy for 1 or 2 days resulted in a significant reduction of melatonin serum levels in MS patients. ConclusionsSince corticosteroids cause a reduction in melatonin serum levels, an important hormone in sleep regulation, their prescription to MS patients should be carefully considered. Corticosteroids could be a cause of insomnia and sleep disturbance in patients receiving this type of medication.

Neuroprotective Effects of Omega-3 Polyunsaturated Fatty Acids in a Rat Model of Anterior Ischemic Optic Neuropathy.

The purpose of this study was to investigate the therapeutic effect of omega-3 polyunsaturated fatty acid (ω-3 PUFA) administration in a rat model of anterior ischemic optic neuropathy (rAION). The level of blood arachidonic acid/eicosapentaenoic acid (AA/EPA) was measured to determine the suggested dosage. The rAION-induced rats were administered fish oil (1 g/day EPA) or phosphate-buffered saline (PBS) by daily gavage for 10 consecutive days to evaluate the neuroprotective effects. Blood fatty acid analysis showed that the AA/EPA ratio was reduced from 17.6 to ≤1.5 after 10 days of fish oil treatment. The retinal ganglion cell (RGC) densities and the P1-N2 amplitude of flash visual-evoked potentials (FVEP) were significantly higher in the ω-3 PUFA-treated group, compared with the PBS-treated group (P < 0.05). The number of apoptotic cells in the RGC layer of the ω-3 PUFA-treated rats was significantly decreased (P < 0.05) compared with that of the PBS-treated rats. Treatment with ω-3 PUFAs reduced the macrophage recruitment at the optic nerve (ON) by 3.17-fold in the rAION model. The M2 macrophage markers, which decrease inflammation, were induced in the ω-3 PUFA-treated group in contrast to the PBS-treated group. In addition, the mRNA levels of tumor necrosis factor-alpha, interleukin-1 beta, and inducible nitric oxide synthase were significantly reduced in the ω-3 PUFA-treated group. The administration of ω-3 PUFAs has neuroprotective effects in rAION, possibly through dual actions of the antiapoptosis of RGCs and anti-inflammation via decreasing inflammatory cell infiltration, as well as the regulation of macrophage polarization to decrease the cytokine-induced injury of the ON.

Rat umbilical cord blood cells attenuate hypoxic\u2013ischemic brain injury in neonatal rats

Increasing evidence has suggested that human umbilical cord blood cells (hUCBC) have a favorable effect on hypoxic–ischemic (HI) brain injury. However, the efficacy of using hUCBCs to treat this injury has been variable and the underlying mechanism remains elusive. Here, we investigated its effectiveness using stereological analysis in an allogeneic system to examine whether intraperitoneal injection of cells derived from UCBCs of green fluorescent protein (GFP)-transgenic rats could ameliorate brain injury in neonatal rats. Three weeks after the HI event, the estimated residual brain volume was larger and motor function improved more in the cell-injected rats than in the control (PBS-treated) rats. The GFP-positive cells were hardly detectable in the brain (0.0057% of injected cells) 9 days after injection. Although 60% of GFP-positive cells in the brain were Iba1-positive, none of these were positive for NeuroD or DCX. While the number of proliferating cells increased in the hippocampus, that of activated microglia/macrophages decreased and a proportion of M2 microglia/macrophages increased in the ipsilateral hemisphere of cell-injected rats. These results suggest that intraperitoneal injection of cells derived from UCBCs could ameliorate HI injury, possibly through an endogenous response and not by supplying differentiated neurons derived from the injected stem cells.

Melatonin exacerbates acute experimental autoimmune encephalomyelitis by enhancing the serum levels of lactate: A potential biomarker of multiple sclerosis progression.

Melatonin has a beneficial role in adult rat models of multiple sclerosis (MS). In this study, melatonin treatment (10mg/kg/d) was investigated in young age (5-6weeks old) Lewis rat model of acute experimental autoimmune encephalomyelitis (EAE) followed by assessing serum levels of lactate and melatonin. Results showed that clinical outcomes were exacerbated in melatonin- (neurological score=6) vs PBS-treated EAE rats (score=5). Melatonin caused a significant increase in serum IFN-γ, in comparison to PBS-treated EAE rats whereas no considerable change in IL-4 levels were found, although they were significantly lower than those of controls. The ratio of IFN-γ/IL-4, an indicator of Th-1/Th-2, was significantly higher in PBS- and melatonin- treated EAE rats, in comparison to controls. Moreover, results showed increased lymphocyte infiltration, activated astrocytes (GFAP+ cells) but also higher demyelinated plaques (MBP-deficient areas) in the lumbar spinal cord of melatonin-treated EAE rats. Finally, serum levels of lactate, but not melatonin, significantly increased in the melatonin group, compared to untreated EAE and normal rats. In conclusion, our results indicated a relationship between age and the development of EAE since a negative impact was found for melatonin on EAE recovery of young rats by enhancing IFN-γ, the ratio of Th1/Th2 cells, and astrocyte activation, which seems to delay the remyelination process. While melatonin levels decline in MS patients, lactate might be a potential diagnostic biomarker for prediction of disease progression. Early administration of melatonin in the acute phase of MS might be harmful and needs further investigations.

Intravenous Injection of Clinical Grade Human MSCs After Experimental Stroke: Functional Benefit and Microvascular Effect.

Stroke is the leading cause of disability in adults. Many current clinical trials use intravenous (IV) administration of human bone marrow-derived mesenchymal stem cells (BM-MSCs). This autologous graft requires a delay for ex vivo expansion of cells. We followed microvascular effects and mechanisms of action involved after an IV injection of human BM-MSCs (hBM-MSCs) at a subacute phase of stroke. Rats underwent a transient middle cerebral artery occlusion (MCAo) or a surgery without occlusion (sham) at day 0 (D0). At D8, rats received an IV injection of 3 million hBM-MSCs or PBS-glutamine. In a longitudinal behavioral follow-up, we showed delayed somatosensory and cognitive benefits 4 to 7 weeks after hBM-MSC injection. In a separate longitudinal in vivo magnetic resonance imaging (MRI) study, we observed an enhanced vascular density in the ischemic area 2 and 3 weeks after hBM-MSC injection. Histology and quantitative polymerase chain reaction (qPCR) revealed an overexpression of angiogenic factors such as Ang1 and transforming growth factor-1 (TGF-1) at D16 in hBM-MSC-treated MCAo rats compared to PBS-treated MCAo rats. Altogether, delayed IV injection of hBM-MSCs provides functional benefits and increases cerebral angiogenesis in the stroke lesion via a release of endogenous angiogenic factors enhancing the stabilization of newborn vessels. Enhanced angiogenesis could therefore be a means of improving functional recovery after stroke.

Neurorestorative Responses to Delayed Human Mesenchymal Stromal Cells Treatment of Stroke in Type 2 Diabetic Rats.

Comorbidity of diabetes mellitus and stroke results in worse functional outcome, poor long-term recovery, and extensive vascular damage. We investigated the neurorestorative effects and mechanisms of stroke treatment with human bone marrow-derived mesenchymal stromal cells (hMSCs) in type 2 diabetes mellitus (T2DM) rats. Adult male Wistar rats were induced with T2DM, subjected to 2 hours of middle cerebral artery occlusion (MCAo) and treated via tail-vein injection with (1) PBS (n=8) and (2) hMSCs (n=10; 5×106) at 3 days after MCAo. In T2DM rats, hMSCs administered at 3 days after MCAo significantly improves neurological function without affecting blood glucose, infarct volume, and incidence of brain hemorrhage in comparison to T2DM-MCAo PBS-treated rats. Delayed hMSC treatment of T2DM stroke significantly improves blood-brain barrier integrity, increases vascular and arterial density and cerebral vascular perfusion, and promotes neuroblast cell migration and white matter remodeling as indicated by increased doublecortin, axon, myelin, and neurofilament density, respectively. Delayed hMSC treatment significantly increases platelet-derived growth factor expression in the ischemic brain, decreases proinflammatory M1 macrophage and increases anti-inflammatory M2 macrophage compared to PBS-treated T2DM-MCAo rats. In vitro data show that hMSCs increase subventricular zone explant cell migration and primary cortical neuron neurite outgrowth, whereas inhibition of platelet-derived growth factor decreases hMSC-induced subventricular zone cell migration and axonal outgrowth. In T2DM stroke rats, delayed hMSC treatment significantly improves neurological functional outcome and increases neurorestorative effects and M2 macrophage polarization. Increasing brain platelet-derived growth factor expression may contribute to hMSC-induced neurorestoration.

Efficacy of Intravitreal Injections of Triamcinolone Acetonide in a Rodent Model of Nonarteritic Anterior Ischemic Optic Neuropathy.

To investigate effects of intravitreal injections of triamcinolone acetonide (IVI-TA) at different times in a rodent model of nonarteritic anterior ischemic optic neuropathy (rAION). After inducing ischemic optic neuropathy, the rats received either IVI-TA (0.32 mg/2 μL) at 1 day (1d-TA), 1 week (7d-TA), 2 weeks (14d-TA), or PBS. The density of retinal ganglion cells (RGCs) was calculated using retrograde Fluorogold labeling. Electrophysiological visual function was assessed by flash visual evoked potentials (FVEPs). Apoptosis assays of the retinal sections and immunohistochemistry of ED1 staining of the optic nerves were performed. Four weeks postinfarct, the 1d- and 7d-TA groups had significantly rescued RGCs in the central (2160 ± 250 mm(2), P = 0.004; 2050 ± 660, P = 0.008, respectively) and midperipheral retinas (1240 ± 130; 1250 ± 220, respectively, both P = 0.004) compared with those of the PBS-treated rats. Flash visual evoked potentials demonstrated improvements in P1 amplitude (μV) in the 1d- and 7d-TA groups (both P < 0.05). Assays of TUNEL showed a decrease in the number of apoptotic cells in the RGC layers of 1d- and 7d-TA-treated retinas compared with the PBS-treated group (both P = 0.004). Cells ED1-positive were significantly decreased in the optic nerve (ON) of the 1d- and 7d-TA groups compared with the PBS group (P = 0.004 and 0.02, respectively). Within 1 week postinfarct of rAION, IVI-TA had neuroprotective effects on RGC survival with an increase in the electrophysiological amplitude of VEPs and a decrease in microglial infiltration in the ONs.

Effects of adipose-derived stem cells plus insulin on erectile function in streptozotocin-induced diabetic rats.

Erectile dysfunction (ED) is a distressing complication in men with diabetes mellitus (DM). This study aimed to investigate the effects of adipose-derived stem cells (ADSCs) plus insulin on ED in streptozotocin (STZ)-induced diabetic rats. Forty-five eight-week-old male Sprague-Dawley rats received intraperitoneal injection of STZ (60 mg/kg). Eight weeks after the induction, the determined diabetic rats were randomly distributed into four groups: rats in DM + PBS group received a one-time intracavernous (IC) injection of phosphate-buffered saline (PBS) solution, DM + ADSCs group received IC injection of ADSCs, DM + Insulin group received subcutaneous injection of neutral protamine Hagedorn twice a day, and DM + ADSCs + Insulin group received both ADSCs and neutral protamine Hagedorn treatments. Another 10 normal rats were served as control group and received IC injection of PBS. Four weeks after the treatments, intracavernous pressure, histopathological changes in penis, functional proteins of ADSCs, and penis were measured. We found that ADSCs expressed vascular endothelial growth factor, TIMP metallopeptidase inhibitor 1 (TIMP-1), and lipopolysaccharide-inducible CXC chemokine (LIX). ADSC injection partially restored cavernous endothelium and smooth muscle contents and nNOS-positive nerves, and reduced apoptosis in penis compared with PBS-treated diabetic rats. Insulin treatment could further modulate inflammatory response and reduce advanced glycation end-product accumulation in penis. Better than single therapy, ADSCs combined with insulin ameliorate ED and pathological changes in diabetic rats to near-normal levels.

Restoration of Polyamine Metabolic Patterns in In Vivo and In Vitro Model of Ischemic Stroke following Human Mesenchymal Stem Cell Treatment.

We investigated changes in PA levels by the treatment of human bone-marrow-derived mesenchymal stem cells (hBM-MSCs) in ischemic stroke in rat brain model and in cultured neuronal SH-SY5Y cells exposed to oxygen-glucose deprivation (OGD). In ischemic rat model, transient middle cerebral artery occlusion (MCAo) was performed for 2 h, followed by intravenous transplantation of hBM-MSCs or phosphate-buffered saline (PBS) the day following MCAo. Metabolic profiling analysis of PAs was examined in brains from three groups: control rats, PBS-treated MCAo rats (MCAo), and hBM-MSCs-treated MCAo rats (MCAo + hBM-MSCs). In ischemic cell model, SH-SY5Y cells were exposed to OGD for 24 h, treated with hBM-MSCs (OGD + hBM-MSCs) prior to continued aerobic incubation, and then samples were collected after coculture for 72 h. In the in vivo MCAo ischemic model, levels of some PAs in brain samples of the MCAo and MCAo + hBM-MSCs groups were significantly different from those of the control group. In particular, putrescine, cadaverine, and spermidine in brain tissues of the MCAo + hBM-MSCs group were significantly reduced in comparison to those in the MCAo group. In the in vitro OGD system, N 1-acetylspermidine, spermidine, N 1-acetylspermine, and spermine in cells of the OGD + hBM-MSCs group were significantly reduced compared to those of OGD group.