Neuroprotective effect of atorvastatin in spinal cord ischemia-reperfusion injury

Preparation of Drug Sustained-Release Scaffold with De-Epithelized Human Amniotic Epithelial Cells and Thiolated Chitosan Nanocarriers and Its Repair Effect on Spinal Cord Injury

The disability rate of spinal cord injury (SCI) is extremely high, and stem cell inhibition is one of the most effective schemes in treating the spinal cord, but the survival rate is extremely low after stem cell transplantation, so it cannot be widely used in clinic. Studies have revealed that loading stem cells with biological scaffolds can effectively improve the survival rate and effect after stem cell transplantation. Therefore, this research was devised to analyze the repair effect of thiolated chitosan nanocarriers scaffold carrying de-epithelized human amniotic epithelial cells (HAECs) on SCI. And we used thiolated chitosan as nanocarriers, aiming to provide a reliable theoretical basis for future clinical practice. Through experiments, we concluded that the Tarlov and BBB scores of rats with SCI were raised under the intervention of thiolated chitosan carrying HAECs, while the inflammatory factors in serum, oxidative stress reaction in spinal cord tissue, apoptosis rate of nerve cells, and autophagy protein expression were all suppressed. Thus, the thiolated chitosan carrying HAECs may be applied to treat SCI by suppressing autophagy protein expression, oxidative stress response, and release of inflammatory factors in spinal cord tissue, which may be a new clinical therapy for SCI in the future. Even though we cannot understand exactly the therapeutic mechanism of thiolated chitosan carrying HAECs for SCI, the real clinical application of thiolated chitosan carrying HAECs needs to be confirmed by human experiments.

Histological Findings After Aortic Cross-Clamping in Preclinical Animal Models

Spinal cord ischemic injury and paralysis are devastating complications after open surgical repair of thoracoabdominal aortic aneurysms. Preclinical models have been developed to simulate the clinical paradigm to better understand the neuropathophysiology and develop therapeutic treatment. Neuropathological findings in the preclinical models have not been comprehensively examined before. This systematic review studies the past 40 years of the histological findings after open surgical repair in preclinical models. Our main finding is that damage is predominantly in the grey matter of the spinal cord, although white matter damage in the spinal cord is also reported. Future research needs to examine the neuropathological findings in preclinical models after endovascular repair, a newer type of surgical repair used to treat aortic aneurysms.

Effect of L-carnitine and atorvastatin on a rat model of ischemia-reperfusion injury of spinal cord

Pro-inflammatory cytokines and reactive oxygen species (ROS) are produced in acute spinal cord injury, leading to myelin breakdown, inflammation, mitochondrial dysfunction, and apoptosis of neurons and glial cells. The aim of the present study was to investigate possible protective effects of L-carnitine (carn) or atorvastatin (ator) on spinal cord ischemia-reperfusion injury (IRI). Rats were randomized into nine equal groups (n = 8): control and control taking carn (100 mg/kg BW), ator (2.5 mg/kg BW) or both, as well as sham-operation, IRI and IRI taking same doses of carn, ator or both. Neurological assessments were done 48 hours after IRI, and serum nitrite/nitrate was measured. Finally, lumbar segments of spinal cord were excised, and part was homogenized and prepared for measuring tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), malondialdehyde (MDA), advanced oxidation protein products (AOPP), reduced glutathione (GSH), glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase. The other part was sectioned for evaluation of histopathological changes and for immunostaining by glial fibrillary acidic protein (GFAP), Bax and Bcl-2. The IRI increased ROS (nitrite/nitrate, MDA, AOPP) and pro-inflammatory cytokines (TNF-α, IL-1β), and decreased antioxidants (GSH, GPx, SOD, catalase) with impaired sensory and motor functions. Astrogliosis was detected by GFAP, and increased apoptosis was demonstrated by increasing Bax and decreasing Bcl-2. Treatment with carn or ator alone decreased TNF-α, IL-1β, nitrite/nitrate, MDA and AOPP, and increased GSH, GPx, SOD, and catalase with improvement of neurological functions and histological studies. Combination of carn and ator improved most of measured IRI-affected parameters better than isolated carn or ator administration.

Advances in immunotherapy for the treatment of spinal cord injury

Spinal cord injury (SCI) is a leading cause of morbidity and disability in the world. Over the past few decades, the exact molecular mechanisms describing secondary, persistent injuries, as well as primary and transient injuries, have attracted massive attention to the clinicians and researchers. Recent investigations have distinctly shown the critical roles of innate and adaptive immune responses in regulating sterile neuroinflammation and functional outcomes after SCI. In past years, some promising advances in immunotherapeutic options have efficaciously been identified for the treatment of SCI. In our narrative review, we have mainly focused on the new therapeutic strategies such as the maturation and apoptosis of immune cells by several agents, mesenchymal stem cells (MSCs) as well as multi-factor combination therapy, which have recently provided novel ideas and prospects for the future treatment of SCI. This article also illustrates the latest progress in clarifying the potential roles of innate and adaptive immune responses in SCI, the progression and specification of prospective immunotherapy and outstanding issues in the area.

Time-Course Changes and Role of Autophagy in Primary Spinal Motor Neurons Subjected to Oxygen-Glucose Deprivation: Insights Into Autophagy Changes in a Cellular Model of Spinal Cord Ischemia

Spinal cord ischemia is a severe clinical complication induced by thoracoabdominal aortic surgery, severe trauma, or compression to the spinal column. As one of the most important functional cells in the spinal cord, spinal motor neurons (SMNs) suffer most during the process since they are vulnerable to ischemic injury due to high demands of energy. Previous researches have tried various animal models or organotypic tissue experiments to mimic the process and get to know the pathogenesis and mechanism. However, little work has been performed on the cellular model of spinal cord ischemia, which has been hampered by the inability to obtain a sufficient number of pure primary SMNs for in vitro study. By optimizing the isolation and culture of SMNs, our laboratory has developed an improved culture system of primary SMNs, which allows cellular models and thus mechanism studies. In the present study, by establishing an in vitro model of spinal cord ischemia, we intended to observe the dynamic time-course changes of SMNs and investigate the role of autophagy in SMNs during the process. It was found that oxygen-glucose deprivation (OGD) resulted in destruction of neural networks and decreased cell viability of primary SMNs, and the severity increased with the prolonging of the OGD time. The OGD treatment enhanced autophagy, which reached a peak at 5 h. Further investigation demonstrated that inhibition of autophagy exacerbated the injury, evidencing that autophagy plays a protective role during the process.

The roles of chemokine (C-X-C motif) ligand 13 in spinal cord ischemia-reperfusion injury in rats

Spinal cord ischemia-reperfusion injury (SCII) remains an unresolved complication and its underlying mechanism has not been fully elucidated. In this study, we studied the role of chemokine (C-X-C motif) ligand 13 (CXCL13) in a rat model of SCII. We examined the time course and cellular distribution of CXCL13 protein in rats after SCII. The effects of siRNA targeting CXCL13 or C-X-C chemokine receptor type 5 (CXCR5) in SCII were also investigated. Neurological function, histological assessment, and disruption of the blood-spinal cord barrier (BSCB) were evaluated. The expression levels of CXCL13, CXCR5, phosphorylated extracellular signal-regulated kinase (p-ERK), caspase-3, interleukin 6 (IL-6), TNF-α, and IL-1β were determined. We found that SCII resulted in impaired hind limb function and increased the expression of CXCL13. In addition, CXCL13 expression demonstrated the most pronounced effect at 24 h after SCII. We reveal that CXCL13 protein was co-expressed with the mature neuron marker NeuN and the microglial marker IBA-1 in spinal cord tissues of model rats. SCII also increased the expression of CXCR5, p-ERK, caspase-3, IL-6, TNF-α, and IL-1β at 24 h after SCII. Pre-treatment with CXCL13 siRNA protected the rats against SCII and decreased the expression of signalling pathway proteins and proinflammatory cytokines mentioned above. CXCR5 siRNA also showed similar protective effects. These findings indicate that CXCL13 is involved in SCII. The CXCL13/CXCR5 axis promotes the development of SCII, possibly via ERK-mediated pathways. Targeting the mechanism of CXCL13 involved in the development of SCII might be a potential approach for the treatment of this condition.

Evaluation of effect of atorvastatin on left ventricular systolic function in rats with myocardial infarction via 2D-STI technique

This report aims to evaluate the effect of atorvastatin (Ator) on left ventricular systolic function in myocardial infarction (MI) rats. Forty healthy adult Sprague-Dawley rats were randomly divided into four groups: Ator group, MI group, sham-operation group and normal group. The left anterior descending coronary arteries were ligated to establish the MI model; after modeling, the Ator group was treated with Ator for 4 consecutive weeks. The echocardiographic detection was performed; the left ventricular myocardial systolic peak velocities, strain and strain rates were analyzed using the 2D-STI technique. After 4 weeks, myocardial tissues were taken from all rats and received the pathological examination. Left ventricular end-diastolic diameter (LVEDD) and left ventricular end-systolic diameter (LVESD) in Ator group and MI group were increased after operation, but left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) were decreased; myocardial function were decreased significantly (p<0.05). After Ator treatment, myocardial function at the 3rd and 4th week after operation increased significantly (p<0.05). After Ator treatment, LVEDD and LVESD decreased while LVEF and LVFS increased in Ator group at the 3rd and 4th week after operation compared with MI group (p<0.05). At the 4th week after operation, LVEDD and LVESD in Ator group were decreased compared with those at the 1st and 2nd week after operation, but LVEF and LVFS were increased compared with those at the 1st, 2nd and 3rd week after operation (p<0.05). Pathological examination showed that necrosis and fibrosis of myocardial cells and inflammatory reaction were obvious in MI group. The inflammatory reaction of myocardial cells and myocardial fibrosis were lighter in Ator group. Ator can effectively improve the left ventricular systolic function in MI rats, which could be related to the reduction of response to inflammation and fibrosis.

A Single Dose of Atorvastatin Applied Acutely after Spinal Cord Injury Suppresses Inflammation, Apoptosis, and Promotes Axon Outgrowth, Which Might Be Essential for Favorable Functional Outcome

The aim of our study was to limit the inflammatory response after a spinal cord injury (SCI) using Atorvastatin (ATR), a potent inhibitor of cholesterol biosynthesis. Adult Wistar rats were divided into five experimental groups: one control group, two Th9 compression (40 g/15 min) groups, and two Th9 compression + ATR (5 mg/kg, i.p.) groups. The animals survived one day and six weeks. ATR applied in a single dose immediately post-SCI strongly reduced IL-1β release at 4 and 24 h and considerably reduced the activation of resident cells at one day post-injury. Acute ATR treatment effectively prevented the excessive infiltration of destructive M1 macrophages cranially, at the lesion site, and caudally (by 66%, 62%, and 52%, respectively) one day post-injury, whereas the infiltration of beneficial M2 macrophages was less affected (by 27%, 41%, and 16%). In addition, at the same time point, ATR visibly decreased caspase-3 cleavage in neurons, astrocytes, and oligodendrocytes. Six weeks post-SCI, ATR increased the expression of neurofilaments in the dorsolateral columns and Gap43-positive fibers in the lateral columns around the epicenter, and from day 30 to 42, significantly improved the motor activity of the hindlimbs. We suggest that early modulation of the inflammatory response via effects on the M1/M2 macrophages and the inhibition of caspase-3 expression could be crucial for the functional outcome.

The role of mast cells and macrophages in amiodarone induced pulmonary fibrosis and the possible attenuating role of atorvastatin

Amiodarone (AM) is an effective anti-arrhythmic drug. We investigated the role of mast cells and macrophages on AM induced pulmonary fibrosis and the action of atorvastatin on this fibrosis. Rats were allocated into four groups; negative control (1), positive control (2), 30 mg/kg body weight/day AM (3) and AM + 10 mg/kg/day atorvastatin (4). Lungs were harvested and prepared for histology and immunohistochemistry. Hematoxylin and eosin stained sections of group 3 exhibited disorganized lung architecture. We found cellular debris in the lumen of both intrapulmonary bronchi and bronchioles with partial disruption of the thickened epithelial lining and mononuclear cellular infiltration into the lamina propria. We also observed thickening of the epithelial lining and the smooth muscle layer. Congested, dilated and thickened blood capillaries and thickened inter-alveolar septa were observed with mononuclear cellular infiltrates in the lung of group 3. Most alveoli were collapsed, but some dilated ones were detected. In some alveoli, type ІІ pneumocytes were increased, while type I cells were decreased. We observed significant increases in the amount of collagen in the thickened inter-alveolar septa, around bronchioles and around blood capillaries in sections from group 3. We found a significant increase in mast cells and alveolar macrophages in group 3 compared to group 1. Mast cells and macrophages appear to play important roles in AM induced pulmonary fibrosis. Atorvastatin appears to attenuate this condition.

Hydrogen sulfide protects against TNF-α induced neuronal cell apoptosis through miR-485-5p/TRADD signaling

BACKGROUND AND OBJECTIVE

Increasing studies suggest that miRNAs are served as responders and regulators for pathological change in human. miR-485-5p is such a miRNA that has been proved to be affected by spinal cord I/R injury. This study was to investigate the functional involvement and mechanism of miR-485-5p in sulfuretted hydrogen (H2S) protecting neural cell from injury.

METHODS

In this study, serum tumor necrosis factor (TNF-α) and miR-485-5p were detected in 20 patients with spinal cord ischemia/reperfusion (I/R) injury and in 20 healthy control. H2S was administered by GYY4137 treatment. Two TNF-α-stimulated neural human cell lines, AGE1.HN and SY-SH-5Y, were used for in vitro I/R experiments. Quantitative RT-PCR was performed to determine miR-485-5p expression. QRT-PCR and western blot were respectively performed to evaluate expression of tumor necrosis factor receptor type 1-associated DEATH domain protein (TRADD).

RESULTS

The result showed that serum TNF-α was significantly reduced in patients compared with healthy control. In vitro TNF-α treatment dose dependently caused GE1.HN and SY-SH-5Y apoptosis, whereas this promotion action was reversed by CYY4137. Moreover, we found that H2S protected neuronal cell against apoptosis via TRADD dependent. By luciferase reporting gene assay, western blot and qRT-PCR, we confirmed that TRADD expression was regulated by miR-485-5p. Such miR-485-5p/TRADD axis was proved to be involved in GE1.HN and SY-SH-5Y neural cell-protective process of H2S.

CONCLUSION

In summary, our data for the first time identifies miR-485-5p/TRADD axis in hydrogen sulfide protecting against TNF-α-induced neuronal cell apoptosis.