Ferroptosis: a critical player and potential therapeutic target in traumatic brain injury and spinal cord injury.

Ferroptosis, a new non-necrotizing programmed cell death (PCD), is driven by iron-dependent phospholipid peroxidation. Ferroptosis plays a key role in secondary traumatic brain injury and secondary spinal cord injury and is closely related to inflammation, immunity, and chronic injuries. The inhibitors against ferroptosis effectively improve iron homeostasis, lipid metabolism, redox stabilization, neuronal remodeling, and functional recovery after trauma. In this review, we elaborate on the latest molecular mechanisms of ferroptosis, emphasize its role in secondary central nervous trauma, and update the medicines used to suppress ferroptosis following injuries.

Exosomes derived from bone marrow mesenchymal stem cells protect the injured spinal cord by inhibiting pericyte pyroptosis.

Mesenchymal stem cell (MSC) transplantation is a promising treatment strategy for spinal cord injury, but immunological rejection and possible tumor formation limit its application. The therapeutic effects of MSCs mainly depend on their release of soluble paracrine factors. Exosomes are essential for the secretion of these paracrine effectors. Bone marrow mesenchymal stem cell-derived exosomes (BMSC-EXOs) can be substituted for BMSCs in cell transplantation. However, the underlying mechanisms remain unclear. In this study, a rat model of T10 spinal cord injury was established using the impact method. Then, 30 minutes and 1 day after spinal cord injury, the rats were administered 200 µL exosomes via the tail vein (200 µg/mL; approximately 1 × 106 BMSCs). Treatment with BMSC-EXOs greatly reduced neuronal cell death, improved myelin arrangement and reduced myelin loss, increased pericyte/endothelial cell coverage on the vascular wall, decreased blood-spinal cord barrier leakage, reduced caspase 1 expression, inhibited interleukin-1ß release, and accelerated locomotor functional recovery in rats with spinal cord injury. In the cell culture experiment, pericytes were treated with interferon-γ and tumor necrosis factor-α. Then, Lipofectamine 3000 was used to deliver lipopolysaccharide into the cells, and the cells were co-incubated with adenosine triphosphate to simulate injury in vitro. Pre-treatment with BMSC-EXOs for 8 hours greatly reduced pericyte pyroptosis and increased pericyte survival rate. These findings suggest that BMSC-EXOs may protect pericytes by inhibiting pyroptosis and by improving blood-spinal cord barrier integrity, thereby promoting the survival of neurons and the extension of nerve fibers, and ultimately improving motor function in rats with spinal cord injury. All protocols were conducted with the approval of the Animal Ethics Committee of Zhengzhou University on March 16, 2019.

The risk factors and prognosis of delayed perihematomal edema in patients with spontaneous intracerebral hemorrhage.

PURPOSE: We hypothesize delayed perihematomal edema (DHE) leads to secondary injury after spontaneous intracerebral hemorrhage (sICH) with a poor prognosis. Hence, we need to investigate the risk factors of DHE and identify whether DHE will predict the poor outcome of sICH. METHODS: We retrospectively recruited 121 patients with sICH admitted to the Department of Neurology from January 2014 to August 2018. After dividing all these patients into DHE group and non-DHE group, we analyzed the potential risk factors and outcome of DHE using a multivariate logistic regression model. RESULTS: We conclude DHE after sICH associates with age, hospitalization time, hematoma shape, blood pressure upon admission, alcohol consumption, blood sodium level, and baseline hematoma volume within 24 hours after symptom onset, among which differences were statistically significant (P < .05). Logistic regression analysis finally identified that age (OR = 0.958, 95% CI = 0.923-0.995) and the baseline hematoma volume (OR = 1.161, 95% CI = 1.089-1.238) were the most significant risk factors for DHE, and moreover, the DHE (OR = 3.062, 95% CI = 1.196-7.839) was also a risk factor for poor prognosis in sICH patients. CONCLUSION: We suggest DHE is a clinical predictor of secondary injury following sICH and poor prognosis. In addition, age and baseline hematoma volume are considered significant high-risk factors for DHE in patients with sICH.

Correlation between tumor necrosis factor alpha mRNA and microRNA-155 expression in rat models and patients with temporal lobe epilepsy.

Accumulative evidence demonstrates that there is an inseparable connection between inflammation and temporal lobe epilepsy (TLE). Some recent studies have found that the multifunctional microRNA-155 (miR-155) is a key regulator in controlling the neuroinflammatory response of TLE rodent animals and patients. The aim of the present study was to investigate the dynamic expression pattern of tumor necrosis factor alpha (TNF-α) as a pro-inflammatory cytokine and miR-155 as a posttranscriptional inflammation-related miRNA in the hippocampus of TLE rat models and patients. We performed real-time quantitative PCR (qRT-PCR) on the rat hippocampus 2 h, 7 days, 21 days and 60 days following kainic acid-induced status epilepticus (SE) and on hippocampi obtained from TLE patients and normal controls. To further characterize the relationship between TNF-α and miR-155, we examined the effect of antagonizing miR-155 on TNF-α secretion using its antagomir. Here, we found that TNF-α secretion and miR-155 expression levels were correlated after SE. The expression of TNF-α reached peak levels in the acute phase (2h post-SE) of seizure and then gradually decreased; however, it rose again in the chronic phase (60 days post-SE). miR-155 expression started to increase 2 h post-SE, reached peak levels in the latent phase (7 days post-SE) of seizure and then gradually decreased. The variation in the trend of miR-155 lagged behind that of TNF-α. In patients with TLE, the expression levels of both TNF-α and miR-155 were also significantly increased. Furthermore, antagonizing miR-155 inhibited the production of TNF-α in the hippocampal tissues of TLE rat models. Our findings demonstrate a critical role for miR-155 in the physiological regulation of the TNF-α pro-inflammatory response and elucidate the role of neuroinflammation in the pathogenesis of TLE. Therefore, regulation of the miR-155/TNF-α axis may be a new therapeutic target for TLE.

The role of the microRNA-146a/complement factor H/interleukin-1ß-mediated inflammatory loop circuit in the perpetuate inflammation of chronic temporal lobe epilepsy.

Increasing evidence indicates that neuroinflammation plays a crucial role in the pathogenesis of temporal lobe epilepsy (TLE). However, it is unclear how the perpetuate inflammation develops. Some recent studies have suggested the possible involvement of microRNA-146a (miR-146a) in the modulation of inflammatory signaling occurring in TLE. To understand how miR-146a modulates inflammatory signaling in TLE, we investigated the role of interleukin-1ß (IL-1ß), miR-146a and human complement factor H (CFH) in the perpetuate inflammation in rat models of chronic TLE and U251 cells. We found that enhancive miR-146a could upregulate the expression of IL-1ß and downregulate the expression of CFH, whereas reductive miR-146a could downregulate the expression of IL-1ß and upregulate the expression of CFH, in hippocampi of chronic TLE rat models. Meanwhile, enhancive miR-146a could increase the abnormal wave forms in the chronic TLE rat models. Additionally, enhancive IL-1ß could feedback downregulate the expression of CFH, upregulate the expression of miR-146a and increase the abnormal wave forms in chronic TLE rat models. After CFH gene knockdown in U251 cells, enhancive miR-146a did not upregulate the expression of IL-1ß. In summary, this study shows that enhancive miR-146a can upregulate the inflammatory factor IL-1ß in chronic TLE by downregulating CFH, and that upregulation of IL-1ß plays an important feedback-regulating role in the expression of miR-146a and CFH, forming a miR-146a-CFH-IL-1ß loop circuit that initiates a cascade of inflammation and then leads to the perpetuate inflammation in TLE. Therefore, modulation of the miR-146a-CFH-IL-1ß loop circuit could be a novel therapeutic target for TLE.

Modulation of liver regeneration via myeloid PTEN deficiency.

Molecular mechanisms that modulate liver regeneration are of critical importance for a number of hepatic disorders. Kupffer cells and natural killer (NK) cells are two cell subsets indispensable for liver regeneration. We have focused on these two populations and, in particular, the interplay between them. Importantly, we demonstrate that deletion of the myeloid phosphatase and tensin homolog on chromosome 10 (PTEN) leading to an M2-like polarization of Kupffer cells, which results in decreased activation of NK cells. In addition, PTEN-deficient Kupffer cells secrete additional factors that facilitate the proliferation of hepatocytes. In conclusion, PTEN is critical for inhibiting M2-like polarization of Kupffer cells after partial hepatectomy, resulting in NK cell activation and thus the inhibition of liver regeneration. Furthermore, PTEN reduces growth factor secretion by Kupffer cells. Our results suggest that targeting PTEN on Kupffer cells may be useful in altering liver regeneration in patients undergoing liver resection.

Circular RNA: a new star in neurological diseases.

Circular RNAs (circRNAs) are novel endogenous non-coding RNAs characterized by the presence of a covalent bond linking the 3' and 5' ends generated by backsplicing. In this review, we summarize a number of the latest theories regarding the biogenesis, properties and functions of circRNAs. Specifically, we focus on the advancing characteristics and functions of circRNAs in the brain and neurological diseases. CircRNAs exhibit the characteristics of species conservation, abundance and tissue/developmental-stage-specific expression in the brain. We also describe the relationship between circRNAs and several neurological diseases and highlight their functions in neurological diseases.

Successful treatment of murine autoimmune cholangitis by parabiosis: Implications for hematopoietic therapy.

There is a significant unmet need in the treatment of primary biliary cirrhosis (PBC) despite significant data on the effector pathways that lead to biliary duct damage. We focused attention on a murine model of PBC, the dominant negative transforming growth factor ß receptor II (Tg) mice. To further define the pathways that lead to biliary pathology in these mice, we developed Tg mice deleted of CD4 cells (CD4(-/-)Tg). Interestingly, these mice developed more severe cholangitis than control Tg mice. These mice, which lack CD4 cells, manifested increased levels of IFN-γ produced by effector CD8 cells. It appears that increased cholangitis is due to the absence of CD4 Treg cells. Based on these data, we parabiosed CD4(-/-)Tg mice with established disease at 8-9 weeks of age with C57BL/6 control mice. Such parabiotic "twins" had a significant reduction in autoimmune cholangitis, even though they had established pathology at the time of surgery. We prepared mixed bone marrow chimera mice constructed from CD4(-/-)Tg and CD8(-/-) mice and not only was cholangitis improved, but a decrease in terminally differentiated CD8(+) T effector cells in the presence of wild type CD4 cells was noted. In conclusion, "correcting" the CD4 T cell subset, even in the presence of pathogenic CD8 T cells, is effective in treating autoimmune cholangitis.

[Effect of p65 gene inhibited by siRNA on differention of rat marrow mesenchymal stem cells into neurons].

OBJECTIVE: To investigate the effect of p65 gene inhibited by siRNA on neuronic differentiation in the marrow mesenchymal stem cells (MSCs). METHODS: The MSCs were transfected with Rn-p65-siRNA. Fasudil hydrochloride induced MSCs differentiating into neurons. The non-transfected group and negative control group (transfected with negative control siRNA marked by Cy3) were used as controls. The fluorescence expressed by transfected MSCs were observed under inverted fluorescence microscope at 24 h,48 h and 72 h after transfected with negative control siRNA. The viability of MSCs was detected by MTT at 24 h, 48 h and 72 h after transfected with Rn-p65-siRNA. The expressions of p65 mRNA and protein in MSCs were detected by RT-PCR and Western blot respectively. The expressions of p65 protein, NSE, MAP-2 and glial fibrillary acidic protein (GFAP) were detected by immunocytochemical method after transfection for 6 h. RESULTS: The fluorescence of MSCs was mostly displayed after transfection of 72 hours and the efficiency of transfection was up to 83.3% ± 3.8%. Meanwhile, the p65 mRNA and p65 protein expressed by MSCs of transfected group were significantly decreased (P < 0.05); MTT displayed that the viability of MSCs was also significantly reduced (P < 0.05). The best efficiency of induction was observed in the transfected group. There were higher expressions of NSE and MAP-2 than the other group (P < 0.05). CONCLUSION: The p65 gene inhibited by siRNA can promote the marrow mesenchymal stem cells to differentiate into neurons.

MicroRNA-9 promotes the neuronal differentiation of rat bone marrow mesenchymal stem cells by activating autophagy.

MicroRNA-9 (miR-9) has been shown to promote the differentiation of bone marrow mesenchymal stem cells into neuronal cells, but the precise mechanism is unclear. Our previous study confirmed that increased autophagic activity improved the efficiency of neuronal differentiation in bone marrow mesenchymal stem cells. Accumulating evidence reveals that miRNAs adjust the autophagic pathways. This study used miR-9-1 lentiviral vector and miR-9-1 inhibitor to modulate the expression level of miR-9. Autophagic activity and neuronal differentiation were measured by the number of light chain-3 (LC3)-positive dots, the ratio of LC3-II/LC3, and the expression levels of the neuronal markers enolase and microtubule-associated protein 2. Results showed that LC3-positive dots, the ratio of LC3-II/LC3, and expression of neuron specific enolase and microtubule-associated protein 2 increased in the miR-9(+) group. The above results suggest that autophagic activity increased and bone marrow mesenchymal stem cells were prone to differentiate into neuronal cells when miR-9 was overexpressed, demonstrating that miR-9 can promote neuronal differentiation by increasing autophagic activity.

Systems biologic analysis of T regulatory cells genetic pathways in murine primary biliary cirrhosis.

CD4(+)Foxp3(+) regulatory T cells (Tregs) play a non-redundant role in control of excessive immune responses, and defects in Tregs have been shown both in patients and murine models of primary biliary cirrhosis (PBC), a progressive autoimmune biliary disease. Herein, we took advantage of a murine model of PBC, the dominant negative transforming growth factor ß receptor II (dnTGFßRII) mice, to assess Treg genetic defects and their functional effects in PBC. By using high-resolution microarrays with verification by PCR and protein expression, we found profound and wide-ranging differences between dnTGFßRII and normal, wild type Tregs. Critical transcription factors were down-regulated including Eos, Ahr, Klf2, Foxp1 in dnTGFßRII Tregs. Functionally, dnTGFßRII Tregs expressed an activated, pro-inflammatory phenotype with upregulation of Ccl5, Granzyme B and IFN-γ. Genetic pathway analysis suggested that the primary effect of loss of TGFß pathway signaling was to down regulate immune regulatory processes, with a secondary upregulation of inflammatory processes. These findings provide new insights into T regulatory genetic defects; aberrations of the identified genes or genetic pathways should be investigated in human PBC Tregs. This approach which takes advantage of biologic pathway analysis illustrates the ability to identify genes/pathways that are affected both independently and dependent on abnormalities in TGFß signaling. Such approaches will become increasingly useful in human autoimmunity.

[A preliminary study of plasma microRNA levels in children with methylmalonic acidemia].

OBJECTIVE: To screen out differentially expressed microRNAs (miRNAs) in the plasma of children with methylmalonic acidemia (MMA), to determine the expression of miR-9-1 in plasma and to preliminarily evaluate the significance of miR-9-1 as a biomarker in MMA. METHODS: Plasma was obtained from 17 MMA children, 10 hyperhomocysteinemia (HHcy) children without MMA (HHcy group), and 10 normal controls. Of 17 MMA children, 12 had HHcy (MMA+HHcy group), and 5 had no HHcy (MMA group). The differentially expressed miRNAs were screened out by miRNA microarray. Differentially expressed miR-9-1 was selected, and plasma miR-9-1 levels were determined by RT-PCR. Urine was collected from MMA patients who received vitamin B12 treatment, and plasma miR-9-1 levels were determined by RT-PCR after treatment. RESULTS: The miRNA microarray analysis showed that 26 miRNAs were differentially expressed, among which 16 miRNAs (including miR-9-1) were down-regulated over 2 times, while 10 miRNAs were up-regulated over 2 times. The MMA+HHcy , MMA and HHcy groups had significantly down-regulated miR-9-1 compared with the normal control group (P<0.01). The patients who showed a good response to vitamin B12 treatment had significantly increased plasma miR-9-1 levels, without significant difference compared with the normal control group. CONCLUSIONS: Plasma miR-9-1 is significantly down-regulated in MMA patients, but it is significantly up-regulated after vitamin B12 treatment, suggesting that miR-9-1 may act as a biomarker in monitoring the progression of MMA.

Effects of resveratrol on apoptosis in a rat model of vascular dementia.

Resveratrol is a natural polyphenol widely present in plants, particularly in the skin of red grapes and in wine. It possesses a wide range of biological effects and exhibits neuroprotective effects in numerous diseases. However, data evaluating the effects of resveratrol in vascular dementia (VaD) are lacking. In the present study, the permanent, bilateral common carotid artery occlusion rat model was used to study the effects of resveratrol on VaD. The Morris water maze was used to test the spatial learning and memory performance of the rats. The expression levels of Bax, Bcl-2, cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP) in the hippocampus were measured. The results showed that resveratrol inhibited memory impairment in the VaD rat model, and attenuated the increases in the expression levels of Bax, cleaved caspase-3 and cleaved PARP and the reductions in the expression levels of Bcl-2 that were induced by VaD. These results provide a novel insight into the neuroprotective effects of resveratrol and its possible therapeutic role in VaD.

[miR-124-1 promotes neural differentiation of rat bone marrow mesenchymal stem cells].

OBJECTIVE: To study the effects of miR-124-1 on neuronal differentiation of rat bone marrow mesenchymal stem cells (MSCs). METHODS: MSCs cells were assigned into three groups: control (uninfected and untransfected), miR-124-1+ (infected with miR-124-1), and miR-124-1- (transfected with Anti-rno-miR-124* Inhibitor). MSCs were induced by ß-mercaptoethanol (ß-ME) to differentiate into neurons. The fluorescence expressed by infected MSCs was observed under an inverted fluorescence microscope. MTT method was used to measure cell survival rate after transfection or infection. Immunocytochemistry, RT-PCR and Western blot methods were used to detect the expression of ß3 tubulin, MAP-2 and GFAP 6 days after ß-ME induction. RESULTS: The expression of miR-124-1 in the miR-124-1+ group was significantly higher 2 days after infection of lentivirus vector compared with the control group (P<0.01). In the miR-124-1- group, the cell survival rate and the miR-124-1 expression level decreased significantly 24 hrs after transfection of anti-rno-miR-124* inhibitor (P<0.01). After 6 days of ß-ME induction, the protein and mRNA expression levels of ß3 tubulin and MAP-2 in the miR-124-1+ group were much higher than the other two groups (P<0.01); while the expression levels of ß3 tubulin and MAP-2 in the miR-124-1-group were lower than the control group (P<0.01). The expression of GFAP in the three groups was weak (<1%). CONCLUSIONS: miR-124 might promote neuronal differentiation of rat MSCs.

[Significance of soluble DLL1 in diagnosis of intracranial infectious diseases in children].

OBJECTIVE: To investigate the significance of soluble DLL1 (Delta-like-1) levels of cerebrospinal fluid (CSF) and serum in the diagnosis of intracranial infection in children. METHODS: Fifty children with intracranial infection, including 20 cases of tuberculous meningitis (TM), 20 cases of viral meningitis (VM) and 10 cases of purulent meningitis (PM), and 20 children without intracranial infection (control group) were enrolled. The levels of soluble DLL1 in CSF and serum were measured using ELISA. RESULTS: The level of CSF soluble DLL1 in the TM group was significantly higher than that in the VM, PM and control groups (2.89 ± 1.72 ng/mL vs 0.14 ± 0.14 ng/mL, 0.27 ± 0.21 ng/mL, 0.13 ± 0.12 ng/mL; P<0.01). The level of serum soluble DLL1 in the TM group was also significantly higher than that in the VM, PM and control groups (12.61 ± 6.45 ng/mL vs 2.28 ± 2.27 ng/mL, 2.38 ± 1.79 ng/mL, 2.26 ± 2.10 ng/mL; P<0.01). The levels of soluble DLL1 in the CSF and serum in the VM and PM groups were not significantly different from those in the control group. CONCLUSIONS: Soluble DLL1 as a novel indicator might have potentially important value in the diagnosis of TM.

Expression and significance of DSCAM in the cerebral cortex of APP transgenic mice.

Down syndrome cell adhesion molecule (DSCAM) plays important roles in the regulation of synaptogenesis, neurite outgrowth, axon guidance and synapse formation. Overexpression of DSCAM in Down syndrome (DS) may be involved in the pathogenesis of mental retardation through an inhibitory action on synaptogenesis/neurite outgrowth, and in the precocious dementia associated with an amyloid precursor protein (APP) dosage effect with enhanced plaque formation. In this report we examined the expression of DSCAM in the cerebral cortex of APP transgenic mice versus age-matched wild-type mice. We found that the level of DSCAM expression increased with increasing age in both groups of mice, up to a maximum at 3 months old. The level of DSCAM expression in APP transgenic mice was significantly higher than in the age-matched wild types. We propose that overexpression of DSCAM in the cerebral cortex might play an important role in the learning and memory defects of APP transgenic mice.

[Clinical analysis of 322 cases of non-epileptic cerebral palsy].

OBJECTIVE: To study the clinical features of non-epileptic seizures associated with cerebral palsy (CP) in children. METHODS: A total of 1 198 children with CP (age: 9 months to 6 years) were enrolled. The children with paroxysmal events were monitored by 24 hrs video-EEG (VEEG) to make sure the seizures were epileptic or non-epileptic. The symptoms, age, CP types and EEG features were observed in children with non-epileptic CP. RESULTS: Five hundred and seventy-eight children (48.24%) presented paroxysmal events. The seizures were epileptic in 231 children (19.28%) and non-epileptic in 322 cases (26.88%). In the 322 cases of non-epileptic CP, the paroxysmal events were of various kinds, including non-epileptic seizure tonic, seizure shake head, shrug shoulder or head hypsokinesis, cry or scream, panic attacks, sleep myoclonic and stereotyped movement. One hundred and fifty-eight (49.1%) out of the 322 children demonstrated nonspecific EEG abnormalities. One hundred and eleven children (34.5%) were misdiagnosed as epilepsy in primary hospitals. The CP children less than one year old showed higher frequency of non-epileptic seizures than the age groups over 1 year and 3 to 6 years. The frequency of non-epileptic seizures was the highest in children with spastic CP (168 cases, 52.2%), followed by dyskinetic CP (69 cases, 21.4%) and mixed type CP (65 cases, 20.2%). CONCLUSIONS: The paroxysmal events in children with CP partially are non-epileptic seizures and it is important to differentiate non-epileptic from epileptic seizures. The frequencies of non-epileptic seizures may be associated with a child's age and CP type.