tretinoin and Infarction--Middle-Cerebral-Artery

Ischemic stroke is a neurological disease that causes brain damage by increasing oxidative stress and ion imbalance. Retinoic acid is a major metabolite of vitamin A and regulates oxidative stress, calcium homeostasis, and cell death. Intracellular calcium is involved in neuronal growth and synaptic plasticity. Parvalbumin is a calcium-binding protein that is mainly expressed in brain. In this study, we investigated whether retinoic acid has neuroprotective effects by controlling intracellular calcium concentration and parvalbumin expression in ischemic brain damage. Middle cerebral artery occlusion (MCAO) was performed to induce cerebral ischemia. Retinoic acid (5 mg/kg) or vehicle was injected into the abdominal cavity for four days before surgery and cerebral cortices were collected 24 h after MCAO for further studies. MCAO damage induced neurological deficits and histopathological changes and decreased parvalbumin expression. However, retinoic acid treatment alleviated these changes. In cultured neurons, glutamate (5 mM) exposure induced neuronal cell death, increased intracellular calcium concentration, and decreased parvalbumin expression. Retinoic acid treatment attenuated these changes against glutamate toxicity in a dose-dependent manner. It also regulates glutamate induced change in bcl-2 and bax expression. The mitigation effects of retinoic acid were greater under non-transfection conditions than under parvalbumin siRNA transfection conditions. Our findings showed that retinoic acid modulates intracellular calcium concentration and parvalbumin expression and prevents apoptosis in ischemic brain injury. In conclusion, retinoic acid contributes to the preservation of neurons from ischemic stroke by controlling parvalbumin expression and apoptosis-related proteins.

Topics: Animals; Apoptosis; Brain Ischemia; Calcium; Glutamic Acid; Infarction, Middle Cerebral Artery; Ischemic Stroke; Neurons; Neuroprotective Agents; Parvalbumins; Rats; Rats, Sprague-Dawley; Tretinoin

Ischemic stroke is a neurological disorder that causes pathological changes by increasing oxidative stress. Retinoic acid is one of the metabolites of vitamin A. It regulates oxidative stress and exerts neuroprotective effects. Thioredoxin is a small redox protein with antioxidant activity. The aim of this study was to investigate whether retinoic acid modulates the expression of thioredoxin in ischemic brain injury. Cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) surgery and retinoic acid (5 mg/kg) or vehicle was administered to adult male rats for four days prior to surgery. MCAO induced neurological deficits and increased oxidative stress and retinoic acid attenuated these changes. Retinoic acid ameliorated the MCAO-induced decrease in thioredoxin expression. MCAO decreases the interaction between thioredoxin and apoptosis signal-regulating kinase 1 (ASK1), and retinoic acid treatment alleviates this decrease. Glutamate (5 mM) exposure induced cell death and decreased thioredoxin expression in cultured neurons. Retinoic acid treatment attenuated these changes in a dose-dependent manner. Retinoic acid prevented the decrease of bcl-2 expression and the increase of bax expression caused by glutamate exposure. Moreover, retinoic acid attenuated the increases in caspase-3, cleaved caspase-3, and cytochrome c in glutamate-exposed neurons. However, the mitigation effects of retinoic acid were lower in thioredoxin siRNA-transfected neurons than in non-transfected neurons. These results demonstrate that retinoic acid regulates oxidative stress and thioredoxin expression, maintains the interaction between thioredoxin and ASK1, and modulates apoptosis-associated proteins. Taken together, these results suggest that retinoic acid has neuroprotective effects by regulating thioredoxin expression and modulating apoptotic pathway.

Topics: Animals; Apoptosis; Brain; Brain Ischemia; Caspase 3; Glutamic Acid; Infarction, Middle Cerebral Artery; Male; Neurons; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Thioredoxins; Tretinoin

Ischemic stroke is a severe neurodegenerative disease with a high mortality rate. Retinoic acid is a representative metabolite of vitamin A. It has many beneficial effects including anti-inflammatory, anti-apoptotic, and neuroprotective effects. The purpose of this study is to identify specific proteins that are regulated by retinoic acid in ischemic stroke. Middle cerebral artery occlusion (MCAO) was performed to induce focal cerebral ischemia. Retinoic acid (5 mg/kg) or vehicle was injected intraperitoneally into male rats for four days prior to MCAO operation. Neurobehavioral tests were performed 24 hr after MCAO and the cerebral cortex was collected for proteomic study. Retinoic acid alleviates neurobehavioral deficits and histopathological changes caused by MCAO. Furthermore, we identified various proteins that were altered by retinoic acid in MCAO damage. Among these identified proteins, adenosylhomocysteinase, isocitrate dehydrogenase [NAD

Topics: Animals; Brain Ischemia; Infarction, Middle Cerebral Artery; Ischemic Stroke; Male; Neurodegenerative Diseases; Neuroprotective Agents; Proteins; Proteomics; Rats; Rats, Sprague-Dawley; Rodent Diseases; Tretinoin

Cerebral ischemia is a neurological disorder that leads to cognitive decline and high mortality. Retinoic acid is a metabolite of vitamin A that has anti-inflammatory and anti-apoptotic effects. This study investigated whether retinoic acid prevents neuronal cell damage on focal cerebral ischemia through modulating apoptosis signaling pathway. Middle cerebral artery occlusion (MCAO) was performed to induce focal cerebral ischemia in adult male rats. Retinoic acid (5 mg/kg) or vehicle was injected intraperitoneally for 4 days prior to MCAO. Neurological behavior deficit tests were performed 24 h after MCAO. Brain edema and infarct volume were measured, and TUNEL histochemistry was carried out. We also investigated the changes in apoptosis-related proteins including bcl-2 family proteins and caspases. MCAO injury induced severe neurological behavior deficits and brain edema. It also increased infarct volume, histopathological damages, and the number of TUNEL-positive cells in cerebral cortex. However, retinoic acid pretreatment attenuated MCAO-induced neurological behavior deficits, brain edema, and infarction. It also alleviated histopathological lesion and decreased the number of TUNEL-positive cells. Bcl-2 and bax proteins are representative bcl-2 family proteins. MCAO injury induced a decrease in bcl-2 expression and an increase in bax expression, and retinoic acid pretreatment alleviated these changes. MCAO injury caused a decrease in bcl-2/bax expression ratio in cerebral cortex, while retinoic acid restored this decrease by MCAO. Moreover, our result showed increases in caspase-9, caspase-3, PARP protein levels in MCAO-operated animals. Retinoic acid pretreatment prevented these increases. We identified the changes in cleaved forms of these proteins, similar to the changes in full-length protein. Activation of caspases and PARP proteins are considered to be representative apoptosis indicators. This study showed that retinoic acid regulates bcl-2 family proteins and caspase proteins in focal cerebral ischemia. Thus, our findings demonstrate that retinoic acid exhibits a neuroprotective effect against ischemic damage by modulating apoptosis signaling pathway.

Topics: Animals; Apoptosis; Caspase 3; Disease Models, Animal; Humans; Infarction, Middle Cerebral Artery; Male; Neurons; Neuroprotective Agents; Proto-Oncogene Proteins c-bcl-2; Rats; Tretinoin

The aim of this study was to investigate whether exogenous retinoic acid (RA) can upregulate the mRNA and protein expression of growth-associated protein 43 (GAP-43), thereby promoting brain functional recovery in a rat distal middle cerebral artery occlusion (MCAO) model of ischemia. A total of 216 male Sprague Dawley rats weighing 300-320 g were divided into 3 groups: sham-operated group, MCAO+vehicle group and MCAO+RA group. Focal cortical infarction was induced with a distal MCAO model. The expression of GAP-43 mRNA and protein in the ipsilateral perifocal region was assessed using qPCR and immunocytochemistry at 1, 3, 7, 14, 21, and 28 days after distal MCAO. In addition, an intraperitoneal injection of RA was given 12 h before MCAO and continued every day until the animal was sacrificed. Following ischemia, the expression of GAP-43 first increased considerably and then decreased. Administration of RA reduced infarction volume, promoted neurological functional recovery and upregulated expression of GAP-43. Administration of RA can ameliorate neuronal damage and promote nerve regeneration by upregulating the expression of GAP-43 in the perifocal region after distal MCAO.

Topics: Animals; Brain Ischemia; GAP-43 Protein; Gene Expression; Immunohistochemistry; Infarction, Middle Cerebral Artery; Male; Neuroprotective Agents; Random Allocation; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; Reproducibility of Results; Time Factors; Tretinoin; Up-Regulation

Stroke is the consequence of limited blood flow to the brain with no established treatment to reduce the neurological deficits. Focusing on therapeutic protocols in targeting subventricular zone (SVZ) neurogenesis has been investigated recently. This study was designed to evaluate the effects of retinoic acid (RA)-pretreated Wharton's jelly mesenchymal stem cells (WJ-MSCs) in combination with triiodothyronine (T3) in the ischemia stroke model. Male Wistar rats were used to induce focal cerebral ischemia by middle cerebral artery occlusion (MCAO). There were seven groups of six animals: Sham, Ischemic, WJ-MSCs, RA-pretreated WJ-MSCs, T3, WJ-MSCs +T3, and RA-pretreated WJ-MSCs + T3. The treatment was performed at 24 h after ischemia, and animals were sacrificed one week later for assessments of retinoid X receptor β (RXRβ), brain-derived neurotrophic factor (BDNF), Sox2 and nestin in the SVZ. Pro-inflammatory cytokines in sera were measured at days four and seven after ischemia. RXRβ, BDNF, Sox2 and nestin had the significant expressions in gene and protein levels in the treatment groups, compared with the ischemic group, which were more vivid in the RA-pretreated WJ-MSCs + T3 (p ≤ 0.05). The same trend was also resulted for the levels of TNF-α and IL-6 at four days after ischemia (p ≤ 0.05). In conclusion, application of RA-pretreated WJ-MSCs + T3 could be beneficial in exerting better neurotrophic function probably via modulation of pro-inflammatory cytokines.

Topics: Animals; Brain-Derived Neurotrophic Factor; Cytokines; Disease Models, Animal; Infarction, Middle Cerebral Artery; Lateral Ventricles; Male; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Nestin; Rats; Rats, Wistar; Retinoid X Receptor beta; SOXB1 Transcription Factors; Stroke; Tretinoin; Triiodothyronine; Wharton Jelly

Perivascular stromal cells (PSCs) are a recently identified cell type that comprises a small percentage of the platelet derived growth factor receptor-β+ cells within the CNS perivascular space. PSCs are activated following injury to the brain or spinal cord, expand in number and contribute to fibrotic scar formation within the injury site. Beyond fibrosis, their high density in the lesion core makes them a potential significant source of signals that act on neural cells adjacent to the lesion site.. Our developmental analysis of PSCs, defined by expression of Collagen1a1 in the maturing brain, revealed that PSCs first appear postnatally and may originate from the meninges. PSCs express many of the same markers as meningeal fibroblasts, including expression of the retinoic acid (RA) synthesis proteins Raldh1 and Raldh2. Using a focal brain ischemia injury model to induce PSC activation and expansion, we show a substantial increase in Raldh1+/Raldh2+ PSCs and Raldh1+ activated macrophages in the lesion core. We find that RA levels are significantly elevated in the ischemic hemisphere and induce signaling in astrocytes and neurons in the peri-infarct region.. This study highlights a dual role for activated, non-neural cells where PSCs deposit fibrotic ECM proteins and, along with macrophages, act as a potentially important source of RA, a potent signaling molecule that could influence recovery events in a neuroprotective fashion following brain injury.

Topics: Animals; Animals, Newborn; Brain; Collagen Type I; Collagen Type I, alpha 1 Chain; Disease Models, Animal; Immunohistochemistry; Infarction, Middle Cerebral Artery; Male; Mice, Inbred C57BL; Mice, Inbred ICR; Mice, Transgenic; Pericytes; Stroke; Stromal Cells; Tretinoin

To investigate the cerebral infarct volume 24 hours after transient middle cerebral artery occlusion (tMCAO) and the proportion of CD4⁺;CD25⁺;Foxp3⁺; regulatory T cells (Tregs) in splenocytes in diverse periods after all-trans retinoic acid (ATRA) treatment in mice, so as to explore whether ATRA have the protection against cerebral ischemia damage in mice through intervening Treg differentiation.. Sixty male Kunming mice were randomly divided into two groups, i.e. pretreatment (n=40) and post-treatment (n=20) groups. Each group was against divided into two subgroups, i.e. tMCAO combined with ATRA treatment group, tMCAO combined with DMSO control group. Pretreatment groups: mice were treated intraperitoneally with ATRA (10 mg/kg) dissolved in 100 mL/L DMSO or equivalent volume of 100 mL/L DMSO daily for 7 days (n=20/group). Ten mice in each group were sacrificed and the proportion of Tregs in splenocytes was analyzed by flow cytometry (FCM) after 7-day pretreatment. The other 10 mice in each group were subjected to tMCAO by modified monofilament method. Neurologic deficit score (NDS) was recorded and the infarct volume was assessed by 2, 3, 5-triphenyltetrazolium chloride(TTC) staining 24 hours after tMCAO. The mice in post-treatment groups were treated intraperitoneally with ATRA (10 mg/kg) or equivalent volume of 100 mL/L DMSO immediately after the reperfusion of tMCAO modeling (n=10/group). NDS and infarct volume were assessed and the proportion of Tregs in splenocytes was analyzed 24 hours after tMCAO.. ATRA pretreatment for 7 days failed to improve neurologic function deficit (P>0.05) and to reduce the cerebral infarct volume (P>0.05) 24 hours after tMCAO in mice. ATRA post-treatment could markedly improve neurologic function (P<0.05) and reduce the cerebral infarct volume (P<0.05) 24 hours after tMCAO. However, neither ATRA pretreatment nor post-treatment had effect on the proportion of Tregs in the splenocytes of mice (P>0.05).. ATRA administered before tMCAO for 7 days failed to protect brain against ischemic damage. ATRA administered immediately following tMCAO induced cerebral protective effect 24 hours after tMCAO. The results suggest that Tregs change is not involved in the neuroprotection mechanism of ATRA.

Topics: Animals; Brain Ischemia; Cerebral Infarction; Flow Cytometry; Infarction, Middle Cerebral Artery; Male; Mice; Neuroprotective Agents; Random Allocation; Spleen; Stroke; T-Lymphocytes, Regulatory; Time Factors; Tretinoin

Neurogenesis is regulated by a number of signaling pathways, including the retinoic acid (RA) pathway, a key regulator of neurogenesis in the subventricular zone (SVZ) and hippocampus. Acupuncture has been used to treat neurological conditions and is known to potentially enhance cell proliferation in the neurogenic area (hippocampal dentate gyrus and the SVZ of the lateral ventricle walls) in pathological conditions, which is associated with improved brain function. However, whether or not the neuroprotective effects of electroacupuncture (EA) are mediated by the regulation of the RA signaling pathway remains to be determined. Using a transient middle cerebral artery occlusion model, in the present study we evaluated the effect of EA on the neurological functional recovery, infarction volume and investigated the underlying molecular mechanisms. Two hundred and sixteen SD rats were randomly divided into 3 groups: sham, model group (ischemic rats without EA stimulation) and EA group (ischemic rats with EA stimulation on ST36 and LI11). Behavioral deficits were detected with high-resolution digital analysis of 24-h home-cage video recordings. Infarct volume was determined by triphenyltetrazolium hydrochloride staining and the expression of RA mRNA and protein was measured using RT-PCR and western blotting, respectively. We found that EA decreased the infarct volume, promoted neurological functional recovery and increased the RA mRNA and protein expression, compared with the model group. Findings of this study suggest that promoting neurological functional recovery by modulating RA expression in the post-ischemic brain is one of the mechanisms by which EA can be effective in the treatment of ischemic stroke.

Topics: Animals; Brain; Brain Ischemia; Cell Proliferation; Disease Models, Animal; Electroacupuncture; Hippocampus; Infarction, Middle Cerebral Artery; Lateral Ventricles; Male; Neurogenesis; Rats; Rats, Sprague-Dawley; Recovery of Function; Reperfusion Injury; Signal Transduction; Stroke; Tetrazolium Salts; Tretinoin

Retinoic acid (RA), a biologically active derivative of vitamin A, has protective effects against damage caused by H(2)O(2) or oxygen-glucose deprivation in mesangial and PC12 cells. In cultured human osteosarcoma cells, RA enhances the expression of bone morphogenetic protein-7 (BMP7), a trophic factor that reduces ischemia- or neurotoxin-mediated neurodegeneration in vivo. The purpose of this study is to examine whether RA reduces ischemic brain injury through a BMP7 mechanism. We found that intracerebroventricular administration of 9-cis-retinoic acid (9cRA) enhanced BMP7 mRNA expression, detected by RT-PCR, in rat cerebral cortex at 24 hr after injection. Rats were also subjected to transient focal ischemia induced by ligation of the middle cerebral artery (MCA) at 1 day after 9cRA injection. Pretreatment with 9cRA increased locomotor activity and attenuated neurological deficits 2 days after MCA ligation. 9cRA also reduced cerebral infarction and TUNEL labeling. These protective responses were antagonized by the BMP antagonist noggin given 1 day after 9cRA injection. Taken together, our data suggest that 9cRA has protective effects against ischemia-induced injury, and these effects involve BMPs.

Topics: Alitretinoin; Animals; Bone Morphogenetic Protein 7; Brain Ischemia; Carrier Proteins; Gene Expression; In Situ Nick-End Labeling; Infarction, Middle Cerebral Artery; Injections, Intraventricular; Male; Motor Activity; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Recovery of Function; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tretinoin

Neurogenesis increases in the adult rodent forebrain subventricular zone (SVZ) after experimental stroke. Newborn neurons migrate to the injured striatum, but few survive long-term and little evidence exists to suggest that they integrate or contribute to functional recovery. One potential strategy to improve stroke recovery is to stimulate neurogenesis and integration of adult-born neurons by using treatments that enhance neurogenesis. We examined the influence of retinoic acid (RA), which stimulates neonatal SVZ and adult hippocampal neurogenesis, and environmental enrichment (EE), which enhances survival of adult-born hippocampal neurons. We hypothesized that the combination of RA and EE would promote survival of adult-generated SVZ-derived neurons and improve functional recovery after stroke. Adult rats underwent middle cerebral artery occlusion, received BrdU on days 5-11 after stroke and were treated with RA/EE, RA alone, EE/vehicle or vehicle alone and were killed 61 days after stroke. Rats underwent repeated MRI and behavioral testing. We found that RA/EE treatment preserved striatal and hemisphere tissue and increased SVZ neurogenesis as demonstrated by Ki67 and doublecortin (DCx) immunolabeling. All treatments influenced the location of BrdU- and DCx-positive cells in the post-stroke striatum. RA/EE increased the number of BrdU/NeuN-positive cells in the injured striatum but did not lead to improvements in behavioral function. These results demonstrate that combined pharmacotherapy and behavioral manipulation enhances post-stroke striatal neurogenesis and decreases infarct volume without promoting detectable functional recovery. Further study of the integration of adult-born neurons in the ischemic striatum is necessary to determine their restorative potential.

Topics: Analysis of Variance; Animals; Cell Proliferation; Cerebral Ventricles; Corpus Striatum; Doublecortin Domain Proteins; Doublecortin Protein; Environment; Immunohistochemistry; Infarction, Middle Cerebral Artery; Male; Microtubule-Associated Proteins; Neurogenesis; Neurons; Neuropeptides; Rats; Rats, Sprague-Dawley; Recovery of Function; Tretinoin

The present study investigates the neuroprotective effects of midkine (MK) and retinoic acid (RA) against ischemia in the CNS. Primary cortical neurons, derived from rat E15 embryos (DIV9), were treated with 9-cis-RA (9cRA), all-trans-RA (atRA) or vehicle. Using quantitative PCR, the level of MK mRNA was significantly increased at 4h after 9cRA application. The protective effect of RA and MK was also investigated in adult Sprague-Dawley rats. 9cRA, atRA, MK, or vehicle was injected into the lateral ventricle prior to a 60-min-MCA ligation. Pretreatment with 9cRA or MK attenuated cerebral infarction in stroke animals. Application of a similar dose of atRA did not reduce the size of infarction. In conclusion, our data suggest that 9cRA has neuroprotective effects against ischemia-related brain injury which may involve upregulation of midkine.

Topics: Alitretinoin; Analysis of Variance; Animals; Blood Gas Analysis; Blood Pressure; Body Temperature; Cells, Cultured; Cerebral Cortex; Cerebral Infarction; Cytokines; Embryo, Mammalian; Infarction, Middle Cerebral Artery; Male; Midkine; Rats; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tetrazolium Salts; Tretinoin