Up-regulating microRNA-214-3p relieves hypoxic-ischemic brain damage through inhibiting TXNIP expression.

A list of microRNAs (miRs) has been referred to involve in the development of hypoxic-ischemic brain damage (HIBD). Based on that, we probed the concrete role of miR-214-3p regulating thioredoxin-interacting protein (TXNIP) in the illness. A neonatal HIBD mouse model was established using the Rice-Vannucci method, followed by measurements of miR-214-3p and TXNIP levels in brain tissues. After modeling, mice were given brain injection of the compounds that could alter miR-214-3p and TXNIP expression. Afterward, neurological function, neuronal inflammation, neuronal apoptosis, neuron morphology, and the number of Nissl body were assessed in HIBD mice. The binding of miR-214-3p to TXNIP was analyzed. Lower miR-214-3p and higher TXNIP were analyzed in brain tissues of mice with HIBD. Up-regulating miR-214-3p or depleting TXNIP improved neurological function, reduced neuronal inflammation and neuronal apoptosis, attenuated morphological damage of neurons, and increased the number of Nissl bodies in mice with HIBD. TXNIP was targeted by miR-214-3p and overexpressing TXNIP reversed the therapeutic effect of miR-214-3p on HIBD mice. It is noted that promotion of miR-214-3p relieves HIBD in mice through inhibiting TXNIP expression.

Regulation of immune-driven pathogenesis in Parkinson's disease by gut microbiota.

Parkinson's disease (PD) is one of the most significant medical and social burdens of our time. The prevalence of PD increases with age and the number of individuals diagnosed with PD is expected to double from 6.9 million in 2015 to 14.2 million in 2040. To date, no drugs can stop the ongoing neurodegeneration caused by PD due to its unclear and complex pathogenic mechanisms. It has been wildly recognized that both gut microbiota and neuro-immunity are involved in the pathology of PD. In this review, we intend to provide a comprehensive overview of current knowledge on how gut microbiota involved in immune-driven pathogenesis of PD, and its potential as a new target of dietary and/or therapeutic interventions for PD.

Vibrio vulnificus meningoencephalitis in a patient with thalassemia and a splenectomy.

Vibrio vulnificus usually causes wound infection, gastroenteritis, and septicemia. However, it is a rare conditional pathogen causing meningoencephalitis. We report a case of a young, immunocompromised man presenting with severe sepsis after exposure to sea water and consumption of seafood. The patient subsequently developed meningoencephalitis, and Vibrio vulnificus was isolated from his blood culture. The sequence was confirmed by Next-generation sequencing of a sample of cerebrospinal fluid, as well as from a bacteria culture. After the pathogen was detected, the patient was treated with ceftriaxone, doxycycline, and moxifloxacin for 6 weeks, which controlled his infection. In this case, we acquired his clinical and dynamic MRI presentations, which were never reported. Physicians should consider Vibrio vulnificus infections when they see a similar clinical course, brain CT and MRI findings, susceptibility factors and recent seafood ingestion or exposure to seawater. Due to high mortality, the early diagnosis and treatment of Vibrio vulnificus infections are crucial. Next-generation sequencing was found to be useful for diagnosis.

Disruption of AT-hook 1 domain in MeCP2 protein caused behavioral abnormality in mice.

MECP2 is the causative gene for autism spectrum disorders, including Rett syndrome, a regressive neurodevelopmental rare disease mainly occurring in girls. Except for the distinct methyl-CpG binding domain and the transcriptional repression domain in MeCP2, three AT-hook-like domains have recently been identified. Several mutations in AT-hook 1 domain have been reported in autism cases or Rett database. However, the role of AT-hook 1 domain is still unclear. In this study, we generated a mouse line carrying deletion of eight conserved amino acids in AT-hook 1 domain by clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technology. Mecp2ΔAT-hook1/y mutant male mice exhibited low locomotor activity, motor incoordination and cognitive deficit. In addition, these mutant mice exhibited increased anxiety. Moreover, pain insensitivity was noted in the mutant males. However, the social interactions were unaffected in AT-hook 1 mutant mice. Thinner CA1 region of the hippocampus was observed in the mutant mice. On the molecular basis, Western blot analysis showed increased expression of mutant MeCP2 protein in the cortex. Additionally, several genes expressed specifically in inhibitory neurons were markedly changed in the cerebrum. Taken together, these data demonstrate that disruption of AT-hook 1 domain in MeCP2 caused behavioral abnormality in mice, which suggests that AT-hook 1 is a critical region for the function of MeCP2 protein.

Adeno-associated virus 9-mediated Cdk5 inhibitory peptide reverses pathologic changes and behavioral deficits in the Alzheimer's disease mouse model.

Cyclin-dependent kinase 5 (Cdk5), which binds to and is activated by p35, phosphorylates multiple substrates and plays an essential role in the development and function of the CNS; however, proteolytic production of p25 from p35 under stress conditions leads to the inappropriate activation of Cdk5 and contributes to hyperphosphorylation of τ and other substrates that are related to the pathogenesis of Alzheimer's disease. Selective inhibition of aberrant Cdk5 activity via genetic overexpression of Cdk5 inhibitory peptide (CIP) reduces pathologic changes and prevents brain atrophy and memory loss in p25-transgenic mice. In the present study, we delivered adeno-associated virus 9 carrying green fluorescent protein-CIP (AAV9-GFP-CIP) to brain cells via intracerebroventricular infusion in amyloid precursor protein/presenilin 1 (APP/PS1) double-transgenic 3-mo-old mice after the occurrence of ß-amyloid (Aß) aggregation and the hyperphosphorylation of τ. Three months of treatment of AAV9-GFP-CIP reduced pathologic changes, including τ hyperphosphorylation, (Aß) deposit, astrocytosis, and microgliosis, which were correlated with the reversal of memory loss and anxiety-like behavior observed in APP/PS1 mice. The neuroprotection effect of AAV9-GFP-CIP lasted an additional 7 mo-the end point of the study. These findings provide a novel strategy to selectively target Cdk5 for the treatment of Alzheimer's disease.-He, Y., Pan, S., Xu, M., He, R., Huang, W., Song, P., Huang, J., Zhang, H.-T., Hu, Y. Adeno-associated virus 9-mediated Cdk5 inhibitory peptide reverses pathologic changes and behavioral deficits in the Alzheimer's disease mouse model.

Identification of a novel DNMT1 mutation in a Chinese patient with hereditary sensory and autonomic neuropathy type IE.

BACKGROUND: DNA methyltransferase 1 (EC 2.1.1.37), encoded by DNMT1 gene, is one of key enzymes in maintaining DNA methylation patterns of the human genome. It plays a crucial role in embryonic development, imprinting and genome stability, cell differentiation. The dysfunction of this group of enzymes can lead to a variety of human genetic disorders. Until now, mutations in DNMT1 have been found to be associated with two distinct phenotypes. Mutations in exon 20 of this gene leads to hereditary sensory and autonomic neuropathy type IE, and mutations in exon 21 cause autosomal dominant cerebellar ataxia, deafness and narcolepsy. CASE PRESENTATION: Here we report a novel DNMT1 mutation in a sporadic case of a Chinese patient with cerebellar ataxia, multiple motor and sensory neuropathy, hearing loss and psychiatric manifestations. Furthermore, we elucidated its pathogenic effect through molecular genetics studies and revealed that this defective DNMT1 function is responsible for the phenotypes in this individual. CONCLUSION: Our findings expand the spectrum of DNMT1-related disorders and provide a good example of precision medicine through the combination of exome sequencing and clinical testing.

Analysis of role of rat cerebral pericytes in cerebral vasospasm after subarachnoid hemorrhage and molecular mechanism of neurovascular injury.

To investigate mechanism of pericytes in the early stage of subarachnoid haemorrhage (SAH) and its associated microvascular spasm and neurovascular injury, 100 healthy 8-week-old Sprague-Dawley male rats were taken as subjects and divided into four groups: group A (sham operation, control group), group B (SAH operation group), group C (SAH operation group treated with scutellarin), and group D (SAH operation group treated with L-nitro-arginine). 72 hours after the operation, the rats were conducted assessment of neurological impairment, observation of microangiography, detection of blood-brain barrier permeability, observation of skull base haemorrhage, identification of pericyte culture, and measurement of blood nitric oxide. The results showed that neurological impairment score, degree of micro-vasoconstriction, and BBB permeability of group C were significantly better than those of group B and D (P<0.05), there was no significant difference between group C and group A (P>0.05). There were significantly fewer blood clots in the brain of group C, and the order of expression levels of α-smooth muscle actin (α-SMA) in perioperative cells of the four groups from highest to lowest were D, B, C, and A. Nitric oxide concentration inhibited expression of α-SMA in pericytes after SAH at both protein and mRNA levels. The detection results of nitric oxide in the blood of four groups of rats confirmed that pericyte phenotype conversion and actin α-SMA expression could be prevented by upregulation of nitric oxide in serum, so as to relieve pathological symptoms after SAH operation.

Analysis of regulatory effect of miR-149-5p on Sphingosine-1-phosphate receptor 2 of pericytes and its neuroprotective molecular mechanism after acute cerebral ischemia reperfusion in rats.

To investigate the effect of miR-149-5p on sphingosine-1-phosphate receptor 2 (S1PR2) expression level and contents of matrix metalloproteinase (MMP-9) and superoxide dismutase (SOD) in the pericytes after acute cerebral ischemia reperfusion in rats, so as to clarify the neuroprotective molecular mechanism induced by miR-149-5p and provide references for the treatment of neurological diseases, 60 male SD rats aged 7-8 weeks were selected and divided randomly into test group (establishing middle cerebral artery occlusion (MCAO) model) and control group (no modeling). Rat pericytes and peripheral cerebral infarction tissues were collected 12 h, 1 d, 3 d, 5 d, and 7 d after MCAO modeling, respectively. The pericytes were identified by immunofluorescence assay (IFA) and transfected with miR-149-5p. Fluorescence quantitative PCR (FQPCR) and Western blot were adopted to detect S1PR2 expression level. The expression of S1PR2 in MCAO model rats was detected by IFA. Immunohistochemistry (IHC) and quantitative real-time PCR (qRT-PCR) were used to detect the changes of MMP9 protein and mRNA levels of SOD1, SOD2, and SOD3 in brain tissue. The results showed that mRNA level and protein expression level of S1PR2 in the test group were higher than those in the control group three days after MCAO modeling (P < 0.05); the expression of S1PR2 increased 12 h after MCAO modeling and returned to the normal level on the 5th day, and the content of MMP9 protein in brain tissue of the test group was significantly lower than that of the control group (P < 0.05); the mRNA levels and SODs activity of SOD1, SOD2, and SOD3 in the test group were higher than those in the control group (P < 0.05). Therefore, miR-149-5p played a neuroprotective role by regulating S1PR2 to change the expression levels of SODS and MMP9.

Cdk5 Inhibitory Peptide Prevents Loss of Dopaminergic Neurons and Alleviates Behavioral Changes in an MPTP Induced Parkinson's Disease Mouse Model.

Parkinson's disease (PD) is one of the most affected neurodegenerative diseases in the world. Deregulation of cyclin-dependent kinase 5 (Cdk5) is believed to play an important role in neurodegenerative diseases including PD. p25 is a cleavage peptide of p35, a physiologic activator of Cdk5. p25 combines to Cdk5 and leads to the hyperactivity of Cdk5, which in turn hyperphosphorylates downstream substrates and leads to neuroinflammation and apoptosis of neurons. Previously, we have demonstrated that adeno-associated virus serotype-9 (AAV9) mediated Cdk5 inhibitory peptide (CIP) inhibits the activity of Cdk5/p25 complex and alleviates pathologic and behavioral changes in Alzheimer's disease mouse model. In this study, we evaluated whether AAV9-CIP protected dopaminergic (DA) neurons in 1-methyl-4-phe-nyl-1,2,3,6-tetrahydropyridine-probenecid (MPTP/p) induced PD mouse model. The data showed that administration of AAV9-CIP by intracerebroventricular injection 1 week before MPTP/p exposure protected loss of DA neurons in substantia nigra compact of the model mice. Importantly, AAV9-CIP also alleviated the motor and anxiety-like symptoms of the disease animals. In summary, AAV9 mediated CIP might be a potential intervention for PD.

Gut microbiota in patients with Parkinson's disease in southern China.

INTRODUCTION: Accumulating evidence has revealed alterations in the communication between the gut and brain in patients with Parkinson's disease (PD), and previous studies have confirmed that alterations in the gut microbiome play an important role in the pathogenesis of numerous diseases, including PD. The aim of this study was to determine whether the faecal microbiome of PD patients in southern China differs from that of control subjects and whether the gut microbiome composition alters among different PD motor phenotypes. METHODS: We compared the gut microbiota composition of 75 patients with PD and 45 age-matched controls using 16S rRNA next-generation-sequencing. RESULTS: We observed significant increases in the abundance of four bacterial families and significant decreases in the abundance of seventeen bacterial families in patients with PD compared to those of the controls. In particular, the abundance of Lachnospiraceae was reduced by 42.9% in patients with PD, whereas Bifidobacteriaceae was enriched in patients with PD. We did not identify a significant difference in the overall microbial composition among different PD motor phenotypes, but we identified the association between specific taxas and different PD motor phenotypes. CONCLUSIONS: PD is accompanied by alterations in the abundance of specific gut microbes. The abundance of certain gut microbes was altered depending on clinical motor phenotypes. Based on our findings, the gut microbiome may be a potential PD biomarker.

Neurodegeneration-Like Pathological and Behavioral Changes in an AAV9-Mediated p25 Overexpression Mouse Model.

BACKGROUND: The transgenic mice models overexpressing human p25 contribute greatly to the in vivo neurotoxic mechanism of p25 in neurodegenerative diseases. However, it is time-consuming to manipulate existing transgenic mice models. OBJECTIVE: Here we aim to establish a novel mouse model of neurodegeneration by overexpressing p25 mediated by recombinant adeno-associated virus serotype 9 (rAAV9). METHODS: AAV9-GFP-p25 encoding GFP-fused p25 driven by synapsin promoter, and the control, AAV9-GFP, were delivered in mice by tail-vein injection. Assessments of p25 expression, neurodegenerative pathology, and behavioral changes were performed. RESULTS: GFP expression was detected by in vivo imaging as early as one week after virus injection. Notably, widespread expression of p25 was obviously found in cortex, hippocampus, and cerebellum in AAV9-GFP-p25 mice. Moreover, decreased hippocampus volumes in AAV9-GFP-p25 mice were detected by 7T MRI examination about one month after injection. Further, these AAV9-GFP-p25 mice exhibited progressive memory impairment from three-month to six-month after virus injection. At last, hyperphosphorylated tau, neurofibrillary tangles, activated astrocytes and microglia cells were elevated in these p25 mice at about six months after virus delivery. However, amyloid-ß plaques, overt neuronal loss, and apoptosis in the hippocampus and cortex were not significantly induced by AAV9-mediated p25 overexpression. CONCLUSION: The AAV9-mediated p25 overexpression mouse model, which is a practical model exhibiting neurodegeneration-like pathological and behavioral changes, provides an easier and time-saving method to explore the functions of p25 in vivo, as well as an alternative tool for development of drugs against neurotoxic of p25.

Cdk5/p25 specific inhibitory peptide TFP5 rescues the loss of dopaminergic neurons in a sub-acute MPTP induced PD mouse model.

Parkinson's disease (PD) is pathologically characterized by progressively loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc) and the formation of Lewy bodies. In 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) induced PD mice models, the calpain- cyclin-dependent kinase 5 (Cdk5)-myocyte enhancer factor 2 (MEF2) signaling has been proven in governing dopaminergic neuronal death. Under MPTP insult, p35 is cleaved by calpain into p25, which binds to Cdk5 and exhibits hyperactivity of Cdk5/p25. Cdk5/p25 inactivates MEF2, a survivor factor, which is critical for DA neuronal death. In this study, neuroprotective effect of the Cdk5/p25 specific peptide, TFP5, was evaluated in sub-acute MPTP induced PD mouse model by intraperitoneal (i.p.) injection of MPTP for five consecutive days. The results indicated that the levels of p35 and p25, and p25/p35 ratio increased in the sub-acute MPTP mice. TFP5 broadly reached cortex neuron, hippocampus and SNpc areas after i.p. injections. Pretreatment with 45mg/kg/day TFP5, as well as 10mgkg/day Cdk5 inhibitor roscovitine, for three days significantly rescued DA neuronal loss up to 9.8% or 9.7% respectively compared to the saline treated group. Treatment of TFP5 and roscovitine reduced the levels of inactive form of MEF2 and cleaved caspase 3, thus protected apoptosis of DA neurons against MPTP insult. Our results propose that TFP5 might be a potential therapeutic candidate for PD.