Ruptura intrakraniálního aneuryzmatu představuje pro pacienta život ohrožující stav s dodnes vysokou mortalitou a morbiditou. Patogeneze vývoje a případné ruptury aneuryzmatu jsou pořád zahaleny rouškou tajemství, což pro vědce představuje velký prostor pro možnosti bádaní. Přes určité limitace mají experimentální modely intrakraniálních aneuryzmat své nenahraditelné místo. Přehledový článek shrnuje dosavadní publikované výsledky experimentálních modelů zaměřených na modely hlodavců, jejich výhody a také limitace. Zároveň čtenáře seznamuje s výsledky naší pilotní studie experimentálního modelu u laboratorní myši.
Rupture of an intracranial aneurysm represents a life-threatening condition with a still high mortality and morbidity. The pathogenesis of aneurysm development and eventual aneurysm rupture are still shrouded in mystery, representing a great field of research opportunities for scientists. Despite certain limitations, experimental models of intracranial aneurysms have their invaluable place. The review article summarizes the published results of current experimental rodent-focused models, their advantages, as well as limitations. At the same time, it introduces the reader to the results of our pilot study of an experimental laboratory mice model.
- MeSH
- experimenty na zvířatech MeSH
- inbrední kmeny myší MeSH
- inbrední kmeny potkanů MeSH
- intrakraniální aneurysma * diagnóza etiologie patofyziologie MeSH
- klinické zkoušky veterinární jako téma MeSH
- nemoci cerebrálních arterií klasifikace MeSH
- prasklé aneurysma etiologie patofyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
Spinal cord injury (SCI) is a devastating condition that has physical and psychological consequences for patients. SCI is accompanied by scar formation and systemic inflammatory response leading to an intense degree of functional loss. The catechin, epigallocatechin gallate (EGCG), an active compound found in green tea, holds neuroprotective features and is known for its anti-inflammatory potential. The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that exists in two functionally distinct complexes termed mTOR complex 1 and 2 (mTORC1; mTORC2). Inhibition of mTORC1 by rapamycin causes neuroprotection, leading to partial recovery from SCI. In this study the effects of EGCG, PP242 (an inhibitor of both complexes of mTOR), and a combination of EGCG and PP242 in SCI have been examined. It has been found that both EGCG and PP242 significantly improved sensory/motor functions following SCI. However, EGCG appeared to be more effective (BBB motor test, from 2 to 8 weeks after SCI, p = 0.019, p = 0.007, p = 0.006, p = 0.006, p = 0.05, p = 0.006, and p = 0.003, respectively). The only exception was the Von Frey test, where EGCG was ineffective, while mTOR inhibition by PP242, as well as PP242 in combination with EGCG, significantly reduced withdrawal latency starting from week three (combinatorial therapy (EGCG + PP242) vs. control at 3, 5, and 7 weeks, p = 0.011, p = 0.007, and p = 0.05, respectively). It has been found that EGCG was as effective as PP242 in suppressing mTOR signaling pathways, as evidenced by a reduction in phosphorylated S6 expression (PP242 (t-test, p < 0.0001) or EGCG (t-test, p = 0.0002)). These results demonstrate that EGCG and PP242 effectively suppress mTOR pathways, resulting in recovery from SCI in rats, and that EGCG acts via suppressing mTOR pathways.
- Publikační typ
- časopisecké články MeSH
Traumatic spinal cord injury (SCI) is untreatable and remains the leading cause of disability. Neuroprotection and recovery after SCI can be partially achieved by rapamycin (RAPA) treatment, an inhibitor of mTORC1, complex 1 of the mammalian target of rapamycin (mTOR) pathway. However, mechanisms regulated by the mTOR pathway are not only controlled by mTORC1, but also by a second mTOR complex (mTORC2). Second-generation inhibitor, pp242, inhibits both mTORC1 and mtORC2, which led us to explore its therapeutic potential after SCI and compare it to RAPA treatment. In a rat balloon-compression model of SCI, the effect of daily RAPA (5 mg/kg; IP) and pp242 (5 mg/kg; IP) treatment on inflammatory responses and autophagy was observed. We demonstrated inhibition of the mTOR pathway after SCI through analysis of p-S6, p-Akt, and p-4E-BP1 levels. Several proinflammatory cytokines were elevated in pp242-treated rats, while RAPA treatment led to a decrease in proinflammatory cytokines. Both RAPA and pp242 treatments caused an upregulation of LC3B and led to improved functional and structural recovery in acute SCI compared to the controls, however, a greater axonal sprouting was seen following RAPA treatment. These results suggest that dual mTOR inhibition by pp242 after SCI induces distinct mechanisms and leads to recovery somewhat inferior to that following RAPA treatment.
- Publikační typ
- časopisecké články MeSH
There is currently no treatment for restoring lost neurological function after stroke. A growing number of studies have highlighted the potential of stem cells. However, the mechanisms underlying their beneficial effect have yet to be explored in sufficient detail. In this study, we transplanted human induced pluripotent stem cell-derived neural precursors (iPSC-NPs) in rat temporary middle cerebral artery occlusion (MCAO) model. Using magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) we monitored the effect of cells and assessed lesion volume and metabolite changes in the brain. We monitored concentration changes of myo-inositol (Ins), Taurine (Tau), Glycerophosphocholine+Phosphocholine (GPC+PCh), N-acetyl-aspartate+N-acetyl-aspartyl-glutamate (NAA+NAAG), Creatine+Phosphocreatine (Cr+PCr), and Glutamate+Glutamine (Glu+Gln) in the brains of control and iPSC-NP-transplanted rats. Based on initial lesion size, animals were divided into small lesion and big lesion groups. In the small lesion control group (SCL), lesion size after 4 months was three times smaller than initial measurements. In the small lesion iPSC-NP-treated group, lesion volume decreased after 1 month and then increased after 4 months. Although animals with small lesions significantly improved their motor skills after iPSC-NP transplantation, animals with big lesions showed no improvement. However, our MRI data demonstrate that in the big lesion iPSC-NP-treated (BTL) group, lesion size increased only up until 1 month after MCAO induction and then decreased. In contrast, in the big lesion control group, lesion size increased throughout the whole experiment. Significantly higher concentrations of Ins, Tau, GPC+PCh, NAA+NAAG, Cr+PCr, and Glu+Gln were found in in contralateral hemisphere in BTL animals 4 months after cell injection. Lesion volume decreased at this time point. Spectroscopic results of metabolite concentrations in lesion correlated with volumetric measurements of lesion, with the highest negative correlation observed for NAA+NAAG. Altogether, our results suggest that iPSC-NP transplantation decreases lesion volume and regulates metabolite concentrations within the normal range expected in healthy tissue. Further research into the ability of iPSC-NPs to differentiate into tissue-specific neurons and its effect on the long-term restoration of lesioned tissue is necessary.
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Traumatic spinal cord injury (SCI) triggers a chain of events that is accompanied by an inflammatory reaction leading to necrotic cell death at the core of the injury site, which is restricted by astrogliosis and apoptotic cell death in the surrounding areas. Activation of nuclear factor-κB (NF-κB) signaling pathway has been shown to be associated with inflammatory response induced by SCI. Here, we elucidate the pattern of activation of NF-κB in the pathology of SCI in rats and investigate the effect of transplantation of spinal neural precursors (SPC-01) on its activity and related astrogliosis. METHODS: Using a rat compression model of SCI, we transplanted SPC-01 cells or injected saline into the lesion 7 days after SCI induction. Paraffin-embedded sections were used to assess p65 NF-κB nuclear translocation at days 1, 3, 7, 10, 14, and 28 and to determine levels of glial scaring, white and gray matter preservation, and cavity size at day 28 after SCI. Additionally, levels of p65 phosphorylated at Serine536 were determined 10, 14, and 28 days after SCI as well as levels of locally secreted TNF-α. RESULTS: We determined a bimodal activation pattern of canonical p65 NF-κB signaling pathway in the pathology of SCI with peaks at 3 and 28 days after injury induction. Transplantation of SCI-01 cells resulted in significant downregulation of TNF-α production at 10 and 14 days after SCI and in strong inhibition of p65 NF-κB activity at 28 days after SCI, mainly in the gray matter. Moreover, reduced formation of glial scar was found in SPC-01-transplanted rats along with enhanced gray matter preservation and reduced cavity size. CONCLUSIONS: The results of this study demonstrate strong immunomodulatory properties of SPC-01 cells based on inhibition of a major signaling pathway. Canonical NF-κB pathway activation underlines much of the immune response after SCI including cytokine, chemokine, and apoptosis-related factor production as well as immune cell activation and infiltration. Reduced inflammation may have led to observed tissue sparing. Additionally, such immune response modulation could have impacted astrocyte activation resulting in a reduced glial scar.
- MeSH
- časové faktory MeSH
- cytokiny metabolismus MeSH
- gliový fibrilární kyselý protein metabolismus MeSH
- glióza chirurgie MeSH
- kmenové buňky fyziologie MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- modely nemocí na zvířatech MeSH
- poranění míchy komplikace MeSH
- potkani Wistar MeSH
- signální transdukce fyziologie MeSH
- transformované buněčné linie MeSH
- transkripční faktor RelA metabolismus MeSH
- transplantace kmenových buněk metody MeSH
- zánět etiologie chirurgie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Methacrylate hydrogels have been extensively used as bridging scaffolds in experimental spinal cord injury (SCI) research. As synthetic materials, they can be modified, which leads to improved bridging of the lesion. Fibronectin, a glycoprotein of the extracellular matrix produced by reactive astrocytes after SCI, is known to promote cell adhesion. We implanted 3 methacrylate hydrogels: a scaffold based on hydroxypropylmethacrylamid (HPMA), 2-hydroxyethylmethacrylate (HEMA) and a HEMA hydrogel with an attached fibronectin (HEMA-Fn) in an experimental model of acute SCI in rats. The animals underwent functional evaluation once a week and the spinal cords were histologically assessed 3 months after hydrogel implantation. We found that both the HPMA and the HEMA-Fn hydrogel scaffolds lead to partial sensory improvement compared to control animals and animals treated with plain HEMA scaffold. The HPMA scaffold showed an increased connective tissue infiltration compared to plain HEMA hydrogels. There was a tendency towards connective tissue infiltration and higher blood vessel ingrowth in the HEMA-Fn scaffold. HPMA hydrogels showed a significantly increased axonal ingrowth compared to HEMA-Fn and plain HEMA; while there were some neurofilaments in the peripheral as well as the central region of the HEMA-Fn scaffold, no neurofilaments were found in plain HEMA hydrogels. In conclusion, HPMA hydrogel as well as the HEMA-Fn scaffold showed better bridging qualities compared to the plain HEMA hydrogel, which resulted in very limited partial sensory improvement.
- MeSH
- axony fyziologie MeSH
- biokompatibilní materiály MeSH
- biologické markery MeSH
- exprese genu MeSH
- extracelulární matrix metabolismus MeSH
- fyziologická neovaskularizace MeSH
- hematoencefalická bariéra metabolismus MeSH
- hojení ran MeSH
- hydrogely * MeSH
- krysa rodu rattus MeSH
- methakryláty * chemie MeSH
- modely nemocí na zvířatech MeSH
- pojivová tkáň MeSH
- poranění míchy etiologie metabolismus patologie terapie MeSH
- regenerace nervu * MeSH
- tkáňové podpůrné struktury MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Systematic inflammatory response after spinal cord injury (SCI) is one of the factors leading to lesion development and a profound degree of functional loss. Anti-inflammatory compounds, such as curcumin and epigallocatechin gallate (EGCG) are known for their neuroprotective effects. In this study, we investigated the effect of combined therapy of curcumin and EGCG in a rat model of acute SCI induced by balloon compression. Immediately after SCI, rats received curcumin, EGCG, curcumin + EGCG or saline [daily intraperitoneal doses (curcumin, 6 mg/kg; EGCG 17 mg/kg)] and weekly intramuscular doses (curcumin, 60 mg/kg; EGCG 17 mg/kg)] for 28 days. Rats were evaluated using behavioral tests (the Basso, Beattie, and Bresnahan (BBB) open-field locomotor test, flat beam test). Spinal cord tissue was analyzed using histological methods (Luxol Blue-cresyl violet staining) and immunohistochemistry (anti-glial fibrillary acidic protein, anti-growth associated protein 43). Cytokine levels (interleukin-1β, interleukin-4, interleukin-2, interleukin-6, macrophage inflammatory protein 1-alpha, and RANTES) were measured using Luminex assay. Quantitative polymerase chain reaction was performed to determine the relative expression of genes (Sort1, Fgf2, Irf5, Mrc1, Olig2, Casp3, Gap43, Gfap, Vegf, NfκB, Cntf) related to regenerative processes in injured spinal cord. We found that all treatments displayed significant behavioral recovery, with no obvious synergistic effect after combined therapy of curcumin and ECGC. Curcumin and EGCG alone or in combination increased axonal sprouting, decreased glial scar formation, and altered the levels of macrophage inflammatory protein 1-alpha, interleukin-1β, interleukin-4 and interleukin-6 cytokines. These results imply that although the expected synergistic response of this combined therapy was less obvious, aspects of tissue regeneration and immune responses in severe SCI were evident.
- Publikační typ
- časopisecké články MeSH
Spinal cord injury (SCI) is a debilitating condition which is characterized by an extended secondary injury due to the presence of inflammatory local milieu. Epigallocatechin gallate (EGCG) appears to possess strong neuroprotective properties. Here, we evaluated the beneficial effect of EGCG on recovery from SCI. Male Wistar rats were given either EGCG or saline directly to the injured spinal cord and thereafter a daily IP injection. Behavior recovery was monitored by BBB, plantar, rotarod and flat-beam tests. The levels of inflammatory cytokines were determined on days 1, 3, 7, 10 and 14 after SCI. Additionally, NF-κB pathway activity was evaluated. The results demonstrated that EGCG-treated rats displayed a superior behavioral performance in a flat beam test, higher axonal sprouting and positive remodelation of glial scar. Cytokine analysis revealed a reduction in IL-6, IL2, MIP1α and RANTES levels on days 1 and 3, and an upregulation of IL-4, IL-12p70 and TNFα 1 day following SCI in EGCG-treated rats. Treatment with EGCG was effective in decreasing the nuclear translocation of subunit p65 (RelA) of the NF-κB dimer, and therefore canonical NF-κB pathway attenuation. A significant increase in the gene expression of growth factors (FGF2 and VEGF), was noted in the spinal cord of EGCG-treated rats. Further, EGCG influenced expression of M1 and M2 macrophage markers. Our results have demonstrated a therapeutic value of EGCG in SCI, as observed by better behavioral performance measured by flat beam test, modulation of inflammatory cytokines and induction of higher axonal sprouting.
- MeSH
- axony účinky léků MeSH
- čaj chemie MeSH
- chování zvířat účinky léků MeSH
- cytokiny metabolismus MeSH
- katechin aplikace a dávkování analogy a deriváty MeSH
- mediátory zánětu metabolismus MeSH
- myelitida komplikace metabolismus MeSH
- neuroprotektivní látky aplikace a dávkování MeSH
- NF-kappa B metabolismus MeSH
- poranění míchy komplikace metabolismus patologie prevence a kontrola MeSH
- potkani Wistar MeSH
- regenerace nervu účinky léků MeSH
- signální transdukce účinky léků MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Despite the huge research into stem cells and their regenerative properties for bone healing, there are still unanswered questions including the recipient's respond to the presence of the stem cells, the fate of stem cells inside the bone defect and the possible advantage in utilizing pre-differentiated cells. To address these problems, we used human multipotent mesenchymal stromal/stem cells (MSCs), GMP Grade, in a rat model of bone formation. In a "bioreactor concept" approach seven Wistar rats were implanted with 0.2 g of synthetic bone scaffold seeded with 2 × 106 MSCs, seven Wistar rats were implanted with 0.2 g of synthetic bone scaffold seeded with 1 × 106 predifferentiated osteoblasts and 1 × 106 pre-differentiated endothelial cells and 14 Wistar rats were implanted with 0.2 g of synthetic bone scaffold without seeded cells into an intramuscular pocket on the left side of their back. The right side of each rat was used as a control, and 0.2 g of synthetic bone scaffold was implanted into the intramuscular pocket alone. To see the early stage healing the samples were harvested 14 days after the implantation, MSCs were detected by positive DAPI and MTCO2 staining in 43% of all the samples implanted with MSCs, and no inflammation signs were present in any implanted animal. New vessels could be found in both groups implanted with MSCs, but not in the control group of animals. However, hematoxylin-eosin staining could not detect newly created bone within the implant in any of the groups. These results were in line with COLL1 staining, where we could detect positive staining only in three cases, all of which were implanted with un-differentiated MSCs. According to our findings, there were no benefits of using the pre-differentiated of MSC.
- MeSH
- fyziologická neovaskularizace MeSH
- mezenchymální kmenové buňky fyziologie MeSH
- osteoblasty fyziologie MeSH
- osteogeneze fyziologie MeSH
- potkani Wistar MeSH
- regenerace kostí fyziologie MeSH
- transplantace mezenchymálních kmenových buněk metody MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Well known for its anti-oxidative and anti-inflammation properties, curcumin is a polyphenol found in the rhizome of Curcuma longa. In this study, we evaluated the effects of curcumin on behavioral recovery, glial scar formation, tissue preservation, axonal sprouting, and inflammation after spinal cord injury (SCI) in male Wistar rats. The rats were randomized into two groups following a balloon compression injury at the level of T9-T10 of the spinal cord, namely vehicle- or curcumin-treated. Curcumin was applied locally on the surface of the injured spinal cord immediately following injury and then given intraperitoneally daily; the control rats were treated with vehicle in the same manner. Curcumin treatment improved behavioral recovery within the first week following SCI as evidenced by improved Basso, Beattie, and Bresnahan (BBB) test and plantar scores, representing locomotor and sensory performance, respectively. Furthermore, curcumin treatment decreased glial scar formation by decreasing the levels of MIP1α, IL-2, and RANTES production and by decreasing NF-κB activity. These results, therefore, demonstrate that curcumin has a profound anti-inflammatory therapeutic potential in the treatment of spinal cord injury, especially when given immediately after the injury.
- MeSH
- antiflogistika farmakologie MeSH
- imunomodulace * MeSH
- krysa rodu rattus MeSH
- kurkumin farmakologie MeSH
- mícha patofyziologie MeSH
- modely nemocí na zvířatech MeSH
- obnova funkce * MeSH
- poranění míchy farmakoterapie imunologie patofyziologie MeSH
- potkani Wistar MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
