Within-Host Resistance and Virulence Evolution of a Hypervirulent Carbapenem-Resistant Klebsiella pneumoniae ST11 Under Antibiotic Pressure.

Background: Hypervirulent carbapenem-resistant Klebsiella pneumoniae (hv-CRKP) has recently aroused an extremely severe health challenge and public concern. However, the underlying mechanisms of fitness costs that accompany antibiotic resistance acquisition remain largely unexplored. Here, we report a hv-CRKP-associated fatal infection and reveal a reduction in virulence due to the acquisition of aminoglycoside resistance. Methods: The bacterial identification, antimicrobial susceptibility, hypermucoviscosity, virulence factors, MLST and serotypes were profiled.The clonal homology and plasmid acquisition among hv-CRKP strains were detected by XbaI and S1-PFGE. The virulence potential of the strains was evaluated using Galleria mellonella larvae infection model, serum resistance assay, capsular polysaccharide quantification, and biofilm formation assay. Genomic variations were identified using whole-genome sequencing (WGS). Results: Four K. pneumoniae carbapenemase (KPC)-producing CRKP strains were consecutively isolated from an 86-year-old patient with severe pneumonia. Whole-genome sequencing (WGS) showed that all four hv-CRKP strains belonged to the ST11-KL64 clone. PFGE analysis revealed that the four ST11-KL64 hv-CRKP strains could be grouped into the same PFGE type. Under the pressure of antibiotics, the antimicrobial resistance of the strains increased and the virulence potential decreased. Further sequencing, using the Nanopore platform, was performed on three representative isolates (WYKP586, WYKP589, and WYKP594). Genomic analysis showed that the plasmids of these three strains underwent a large number of breaks and recombination events under antibiotic pressure. We found that as aminoglycoside resistance emerged via acquisition of the rmtB gene, the hypermucoviscosity and virulence of the strains decreased because of internal mutations in the rmpA and rmpA2 genes. Conclusion: This study shows that ST11-KL64 hv-CRKP can further evolve to acquire aminoglycoside resistance accompanied by decreased virulence to adapt to antibiotic pressure in the host.

Clinical implications and mechanism of complement C1q in polymyositis.

Polymyositis (PM) is the most common autoimmune disease in neurology and among muscle disorders; it is of great significance to thoroughly understand the mechanism of PM to find new diagnosis and treatment methods. This research intends to elucidate the clinical implications and mechanisms of complement C1q in polymyositis (PM). One hundred fifteen PM patients (research group, RG) and 120 healthy subjects (control group, CG) who visited our hospital between March 2017 and March 2020 were selected. Peripheral blood C1q and creatine kinase (CK) levels of both groups were measured, and their correlations with clinical symptoms and prognostic recurrence of PM. Additionally, to further understand the mechanism of action of C1q in PM, we purchased BALB/c mice and grouped them as follows: control group with normal feeding, PM group with PM modeling, intervention group with PM modeling, and intraperitoneal injection of gC1qR monoclonal antibody 60.11, a C1q protein receptor. Inflammatory factors and muscle histopathology were detected in all groups of mice. Finally, rat macrophages (mø) were isolated, and changes in the biological behavior of mø were observed after silencing the expression of gC1qR. Serum C1q and CK were both higher in RG than in CG, with favorable diagnostic effects on PM (P < 0.05). C1q and CK increased in symptomatic anti-ribonuclear protein antibody (RNP)-positive patients but decreased in anti Jo-1 antibody (Jo-1)- and anti-neutrophil cytoplasmic antibody (ANCA)-positive patients (P < 0.05). PM mice were observed with elevated gC1qR, while model mice exhibited severe infiltration of inflammatory cells in muscle tissue, increased pro-IFs, and reduced anti-IFs, and the animals in the intervention group showed improved conditions (P < 0.05). Finally, it was found that CD68, CD86 protein, and invasion capacity of gC1qR-sh-transfected cells decreased, while CD206 and CD163 increased (P < 0.05). C1q is elevated in PM and is strongly linked to the pathological process of PM. Inhibition of gC1qR expression reduced inflammatory infiltration in PM mice.

Clinical and Molecular Characteristics of Carbapenem-Resistant Hypervirulent Klebsiella pneumoniae Isolates in a Tertiary Hospital in Shanghai, China.

BACKGROUND: The convergence of carbapenem-resistance and hypervirulence in Klebsiella pneumoniae has led to a significant public health challenge. In recent years, there have been more and more reports on carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) isolates. MATERIALS AND METHODS: Clinical data of patients infected with CR-hvKP from January 2019 to December 2020 in a tertiary hospital were retrospectively evaluated. The number of isolates of Klebsiella pneumoniae, hypermucoviscous Klebsiella pneumoniae (hmKP), carbapenem-resistant hypermucoviscous Klebsiella pneumoniae (CR-hmKP) and carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) collected during the period of 2 years was calculated. The antimicrobial resistance gene, virulence-associated gene, capsular serotype gene and multilocus sequence typing (MLST) of CR-hvKP isolates were detected by PCR. RESULTS: During the study period, a total of 1081 isolates of non-repeat Klebsiella pneumoniae were isolated, including 392 isolates of hypermucoviscous Klebsiella pneumoniae (36.3%), 39 isolates of CR-hmKP (3.6%), and 16 isolates of CR-hvKP (1.5%). About 31.2% (5/16) of CR-hvKP were isolated from 2019, and 68.8% (11/16) of CR-hvKP were isolated from 2020. Among the 16 isolates of CR-hvKP, 13 isolates were ST11 and serotype K64, 1 isolate was ST11 and serotype K47, 1 isolate was ST23 and serotype K1, and 1 isolate was ST86 and serotype K2. The virulence-associated genes entB, fimH, rmpA2, iutA, iucA were present in all of 16 CR-hvKP isolates, followed by mrkD (n=14), rmpA (n=13), aerobactin (n=2), allS (n=1). Sixteen CR-hvKP isolates all carry carbapenemase gene bla KPC-2 and extended-spectrum ß-lactamase gene bla SHV. ERIC-PCR DNA fingerprinting results showed that 16 CR-hvKP isolates were highly polymorphic, and there were significant differences in bands among the isolates, presenting a sporadic state. CONCLUSION: Although CR-hvKP was sporadically distributed, it showed an increasing trend year by year. Therefore, clinical attention should be paid, and necessary measures should be taken to avoid the cloning and transmission of superbacterium CR-hvKP.

Complex intracranial vascular complications caused by essential thrombocythemia: a critical case report.

BACKGROUND: Essential thrombocythemia (ET) is a myeloproliferative neoplasm characterized by elevated and dysfunctional platelets. ET can result in systemic thrombotic and hemorrhagic complications, and it's a rare cause of stroke. The coexistence of multiple vascular lesions has seldom been reported in patients with essential thrombocythemia. CASE PRESENTATION: A young woman presented with isolated and persistent vertigo and vomiting. The CT scan indicated a hyperdense lesion in the right cerebellar hemisphere. No signs of cerebral artery malformation were observed in the CT angiography (CTA). Besides, the blood tests indicated an increase in platelet and white blood cell counts. The patient then suddenly developed a transient unconsciousness with left horizontal nystagmus when staring to the right. The subsequent cranial magnetic resonance imaging (MRI) scans indicated a diffuse and acute infarction of the pons and hemorrhage in the bilateral cerebellums. Further digital subtraction angiography (DSA) revealed a progressive and critical intracranial vertebral arterial occlusion. The patient's clinical condition stabilized after cytoreductive therapy with interferon-α (IFN-α), even though endovascular and antiplatelet treatments were restricted because of the simultaneous presence of intracerebral hemorrhage (ICH) and ischemic stroke. A JAK2 V617F mutation was later detected through genetic testing, further confirming the diagnosis of ET. The patient was treated with a continuous regimen of IFN-α, and an antiplatelet treatment (aspirin) was added after ICH. The 1-year follow-up indicated normal platelet levels and no additional stroke event. CONCLUSIONS: This case demonstrates that ET can be a rare cause of the cerebrovascular disease (CVD), even though the coexistence of ischemic and hemorrhagic complications. Underlying hematological system diseases should be taken into account when abnormal hemogram and CVD are concurrent in a patient. An early multidisciplinary diagnosis and intervention could significantly improve patient's prognosis.

Influence of genetic polymorphisms in homocysteine and lipid metabolism systems on antidepressant drug response.

BACKGROUND: Variation in genes implicated in homocysteine and lipid metabolism systems may influence antidepressant response for patients with major depressive disorder (MDD). This study aimed to investigate whether association of polymorphisms on the MTHFR, ApoE and ApoA4 genes with the treatment response in MDD subjects. METHODS: A total of 281 Han Chinese MDD patients received a single antidepressant drug (SSRI or SNRI) for at least 6 weeks, among whom 275 were followed up for 8 weeks. Their response to 6 weeks' treatment and remission to 8 weeks' treatment with antidepressant drugs was determined by changes in the 17-item Hamilton Depression Rating Scale (HARS-17) score. Single SNP and haplotype associations with treatment response were analyzed by UNPHASED 3.0.13. Logistic regression analysis was used to explore the interactions between genotypes and gender or drug type on treatment outcome, only those SNPs that had interactional association with gender or drug type were subjected to further stratified analysis. RESULTS: In total group, the haplotype (C-A) in MTHFR (rsl801133 and rs1801131) and the ApoE rs405509 AA genotype were significantly associated with better efficacy of antidepressants; In gender subgroups, only haplotype (C-A) in MTHFR (rsl801133 and rs1801131) was significantly associated with better efficacy of antidepressants in male subgroup; In drug type subgroup, the haplotype (C-A) in MTHFR (rsl801133 and rs1801131) and haplotype (G-C) in ApoE (rs7412 and rs405509) were associated with better efficacy of antidepressants in SNRI treated subgroup; The ApoA4 rs5092 G allele and GG genotype were associated with worse efficacy of antidepressants in SNRI treated subgroup. CONCLUSIONS: Genetic polymorphisms in homocysteine and lipid metabolism systems are associated with antidepressant response, particularly for the interactions of the certain genetic with gender or drug type.

Distinct Disruptive Patterns of Default Mode Subnetwork Connectivity Across the Spectrum of Preclinical Alzheimer's Disease.

Background: The early progression continuum of Alzheimer's disease (AD) has been considered to advance through subjective cognitive decline (SCD), non-amnestic mild cognitive impairment (naMCI), and amnestic mild cognitive impairment (aMCI). Altered functional connectivity (FC) in the default mode network (DMN) is regarded as a hallmark of AD. Furthermore, the DMN can be divided into two subnetworks, the anterior and posterior subnetworks. However, little is known about distinct disruptive patterns in the subsystems of the DMN across the preclinical AD spectrum. This study investigated the connectivity patterns of anterior DMN (aDMN) and posterior DMN (pDMN) across the preclinical AD spectrum. Methods: Resting-state functional magnetic resonance imaging (rs-fMRI) was used to investigate the FC in the DMN subnetworks in 20 healthy controls (HC), eight SCD, 11 naMCI, and 28 aMCI patients. Moreover, a correlation analysis was used to examine associations between the altered connectivity of the DMN subnetworks and the neurocognitive performance. Results: Compared to the HC, SCD patients showed increased FC in the bilateral superior frontal gyrus (SFG), naMCI patients showed increased FC in the left inferior parietal lobule (IPL), and aMCI patients showed increased FC in the bilateral IPL in the aDMN; while SCD patients showed decreased FC in the precuneus, naMCI patients showed increased FC in the left middle temporal gyrus (MTG), and aMCI patients also showed increased FC in the right middle frontal gyrus (MFG) in the pDMN. Notably, the FC between the ventromedial prefrontal cortex (vmPFC) and the left MFG and the IPL in the aDMN was associated with episodic memory in the SCD and aMCI groups. Interestingly, the FC between the posterior cingulated cortex (PCC) and several regions in the pDMN was associated with other cognitive functions in the SCD and naMCI groups. Conclusions: This study demonstrates that the three preclinical stages of AD exhibit distinct FC alternations in the DMN subnetworks. Furthermore, the patient group data showed that the altered FC involves cognitive function. These findings can provide novel insights for tailored clinical intervention across the preclinical AD spectrum.

Brain insulin resistance deteriorates cognition by altering the topological features of brain networks.

Insulin resistance represents one of the mechanisms underlying the link between type 2 diabetes (T2D) and Alzheimer's disease (AD), and we explored its in vivo neurobiology related to cognition based on a pathway-based genetic association analyses. Eighty-seven mild cognitive impairment (MCIs) subjects and 135 matched controls (HCs) were employed at baseline, and they underwent functional MRI scans, clinical evaluations and exon sequencings of 20 genes related to brain insulin resistance. A longitudinal study for an average of 35 months was performed to assess their cognitive decline over time. By using cognition as the phenotype, we detected genes that modified cognitive impairments, including AKT2, PIK3CB, IGF1R, PIK3CD, MTOR, IDE, AKT1S1 and AKT1. Based on these loci, the mass univariate modeling was utilized to construct the functional network. The MCIs showed disconnections mainly in the cerebellum-frontal-temporal regions, while compensations may occur in frontal-parietal regions to maintain the overall network efficiency. Moreover, the behavioral significance of the network was highlighted, as topological characteristics of the medial temporal lobe and the prefrontal cortex partially determine longitudinal cognitive decline. Our results suggested that the restoration of insulin activity represents a promising therapeutic target for alleviating cognitive decline associated with T2D and AD.

Integration of Multilocus Genetic Risk into the Default Mode Network Longitudinal Trajectory during the Alzheimer's Disease Process.

The aim of the study was to investigate the cognitive significance of the changes in default mode network (DMN) during the process of Alzheimer's disease (AD) and the genetic basis that drives the alteration. Eighty-seven subjects with mild cognitive impairment (MCI) and 131 healthy controls (HC) were employed at baseline, and they had the genetic risk scores (GRS) based on the GWAS-validated AD-related top loci. Eleven MCIs who converted to AD (c-MCIs), 32 subjects who remained stable (nc-MCIs), and 56 HCs participated in the follow-up analyses after an average of 35 months. Decreased functional connectivity (FC) within temporal cortex was identified for MCIs at baseline, which was partially determined by the GRS; moreover, compensations may occur within the frontal-parietal brain to maintain relatively intact cognition. During the follow-ups, c-MCIs exhibited more FC declines within the prefrontal-parietal lobes and parahippocampal gyrus/hippocampus than the HCs and nc-MCIs. The GRS did not significantly vary among the three groups, whereas associations were identified at risky alleles and FC declines in all AD spectra. Interestingly, the influence of APOEɛ4 varied as the disease progressed; APOEɛ4 was associated with longitudinal FC decreases only for HCs in the single variance-based analyses and deteriorated DMN integration in nc-MCIs by combining the effects of other loci. However, the GRS without APOEɛ4 predicted FC decline for converters. It is suggested that the integration of multilocus genetic risk predicted the longitudinal trajectory of DMN and may be used as a clinical strategy to track AD progression.

The Promotion of Neural Regeneration in A Rat Facial Nerve Crush Injury Model Using Collagen-Binding NT-3.

Traumatic facial nerve injury, an important cause of facial paralysis, has a number of adverse effects, including facial muscle dysfunction and facial asymmetry. It has been demonstrated in our previous work that native human NT-3 fused with a collagen-binding domain (CBD-NT-3) could bind to collagen, specifically to exert neurotrophic effects, promoting axonal regeneration. To evaluate the effect of CBD-NT-3 in inducing facial nerve regeneration and functional recovery, the differing effects of CBD-NT-3 and native neurotrophin-3 (NAT-NT-3) were observed using the results of facial nerve functional recovery, electrophysiological testing, and axonal and myelin changes in a rat model of facial nerve crush injury. The rats were injected in the epineurium in crushed fibers of the facial nerve with CBD-NT-3, NAT-NT-3, and PBS respectively. After 4 weeks, the CBD-NT-3 group demonstrated significantly more ordered growth of axons and nerve functional recovery than the NAT-NT-3 group. The results suggest that CBD-NT-3 considerably enhances facial nerve regeneration and functional recovery.

Differential Effects of APOE Genotypes on the Anterior and Posterior Subnetworks of Default Mode Network in Amnestic Mild Cognitive Impairment.

BACKGROUND: The apolipoprotein E (APOE) ɛ4 carriers are at increased risk of developing Alzheimer's disease (AD) while the ɛ2 carriers appear to be protected against the disease. The default mode network (DMN), based in ventromedial prefrontal cortex (vmPFC) and posterior cingulate cortex (PCC), consists of functionally differentiable anterior and posterior subnetworks. OBJECTIVE: This study was to investigate whether there are differential effects of APOE polymorphisms on DMN subnetworks in amnestic mild cognitive impairment (aMCI). METHODS: Functional connectivity (FC) analyses were performed in DMN subnetworks in 74 aMCI (9 APOE ɛ2ɛ3, 44 ɛ3ɛ3, and 21 ɛ3ɛ4) and 105 healthy controls (HC; 32 APOE ɛ2ɛ3, 39 ɛ3ɛ3, and 34 ɛ3ɛ4). Logistic regression analysis was performed to obtain a model for classifying aMCI and HC. RESULTS: Significant interactions of APOE by aMCI on FCs were found in right cerebellum posterior lobe, left lingual gyrus, and right middle cingulate cortex in the vmPFC subnetwork, and bilateral fusiform gyrus, left inferior frontal gyrus, and left precuneus in the PCC subnetwork. The impairment of episodic memory for ɛ4-carriers in aMCI negatively correlated with altered FC between vmPFC and right middle cingulate cortex, while positively correlated with altered FC between PCC and left fusiform gyrus. A model composed of episodic memory and FCs dexterity correctly classified 89.4% of aMCI and HC. CONCLUSIONS: APOE ɛ4 and ɛ2 alleles differentially mediate anterior and posterior DMN subnetworks. Furthermore, it further suggests that the anterior and posterior DMN subnetworks in aMCI play an opposing role on the impairment of episodic memory.

Mediation of episodic memory performance by the executive function network in patients with amnestic mild cognitive impairment: a resting-state functional MRI study.

Deficits in episodic memory (EM) are a hallmark clinical symptom of patients with amnestic mild cognitive impairment (aMCI). Impairments in executive function (EF) are widely considered to exacerbate memory deficits and to increase the risk of conversion from aMCI to Alzheimer's disease (AD). However, the specific mechanisms underlying the interaction between executive dysfunction and memory deficits in aMCI patients remain unclear. Thus, the present study utilized resting-state functional magnetic resonance imaging (fMRI) scans of the EF network and the EM network to investigate this relationship in 79 aMCI patients and 119 healthy controls (HC). The seeds were obtained from the results of a regional homogeneity (ReHo) analysis. Functional connectivity (FC) within the EM network was determined using a seed in the right retrosplenial cortex (RSC), and FC within EF network was assessed using seeds in the right dorsolateral prefrontal cortex (DLPFC). There was a significant negative correlation between EM scores and EF scores in both the aMCI and HC groups. Compared to the HC group, aMCI patients had reduced right RSC connectivity but enhanced right DLPFC connectivity. The overlapping brain regions between the EM and EF networks were associated with FC in the right inferior parietal lobule (IPL) in the right RSC network, and in the bilateral middle cingulate cortex (MCC) and left IPL in the right DLPFC network. A mediation analysis revealed that the EF network had an indirect positive effect on EM performance in the aMCI patients. The present findings provide new insights into the neural mechanisms underlying the interaction between impaired EF and memory deficits in aMCI patients and suggest that the EF network may mediate EM performance in this population.

The linear-ordered collagen scaffold-BDNF complex significantly promotes functional recovery after completely transected spinal cord injury in canine.

Spinal cord injury (SCI) is still a worldwide clinical challenge for which there is no viable therapeutic method. We focused on developing combinatorial methods targeting the complex pathological process of SCI. In this study, we implanted linear-ordered collagen scaffold (LOCS) fibers with collagen binding brain-derived neurotrophic factor (BDNF) by tagging a collagen-binding domain (CBD) (LOCS + CBD-BDNF) in completely transected canine SCI with multisystem rehabilitation to validate its potential therapeutic effect through a long-term (38 weeks) observation. We found that LOCS + CBD-BDNF implants strikingly promoted locomotion and functional sensory recovery, with some dogs standing unassisted and transiently moving. Further histological analysis showed that administration of LOCS + CBD-BDNF reduced lesion volume, decreased collagen deposits, promoted axon regeneration and improved myelination, leading to functional recovery. Collectively, LOCS + CBD-BDNF showed striking therapeutic effect on completely transected canine SCI model and it is the first time to report such breakthrough in the war with SCI. Undoubtedly, it is a potentially promising therapeutic method for SCI paralysis or other movement disorders caused by neurological diseases in the future.

Curcumin modulates TLR4/NF-κB inflammatory signaling pathway following traumatic spinal cord injury in rats.

BACKGROUND: Curcumin, a polyphenolic compound extracted from the plant turmeric, has protective effects on spinal cord injury (SCI) through attenuation of inflammatory response. This study was designed to detect whether curcumin modulates toll-like receptor 4 (TLR4) and the nuclear factor-kappa B (NF-κB) inflammatory signaling pathway in the injured rat spinal cord following SCI. METHODS: Adult male Sprague-Dawley rats were subjected to laminectomy at T8-T9 and compression with a vascular clip. There were three groups: (a) sham group; (b) SCI group; and (g) SCI + curcumin group. We measured TLR4 gene and protein expression by real-time polymerase chain reaction and western blot analysis; NF-κB activity by electrophoretic mobility shift assay, inflammatory cytokines tumor necrosis factor-α, interleukin-1ß, and interleukin-6 levels by enzyme-linked immunosorbent assay, hindlimb locomotion function by Basso, Beattie, and Bresnahan rating, spinal cord edema by wet/dry weight method, and apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) analysis. RESULTS: The results showed that SCI induced the up-regulation of TLR4, NF-κB, and inflammatory cytokines in the injured rat spinal cord. Treatment with curcumin following SCI markedly down-regulated the levels of these agents related to the TLR4/NF-κB inflammatory signaling pathway. Administration of curcumin also significantly ameliorated SCI induced hind limb locomotion deficits, spinal cord edema, and apoptosis. CONCLUSIONS: Post-SCI curcumin administration attenuates the TLR4/NF-κB inflammatory signaling pathway in the injured spinal cord, and this may be a mechanism whereby curcumin improves the outcome following SCI.

Tert-butylhydroquinone protects the spinal cord against inflammatory response produced by spinal cord injury.

Antioxidant transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) has been shown in our previous studies to play an important role in protection against spinal cord injury (SCI) induced inflammatory response. The objective of this study was to test whether tert-butylhydroquinone (tBHQ), a novel Nrf2 activator, can protect the spinal cord against SCI-induced inflammatory damage. Adult male Sprague-Dawley rats were subjected to laminectomy at T8-T9 and compression with a vascular clip. Three groups were analyzed: a sham group, a SCI group, and a SCI+rhEPO group (n=16 per group). We measured Nrf2 and nuclear factor kappa B (NF-κB) binding activities by an electrophoretic mobility shift assay (EMSA). We also measured the concentrations of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) by an enzyme-linked immunosorbent assay (ELISA); we also measured hindlimb locomotion function by the Basso, Beattie, and Bresnahan (BBB) rating, spinal cord edema by wet/dry weight method, and apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) analysis. The results showed that the induction of the Nrf2 activity by tBHQ markedly decreased NF-κB activation and inflammatory cytokines production in the injured spinal cord. Administration of tBHQ also significantly attenuated SCI induced hindlimb locomotion deficits, spinal cord edema, and apoptosis. To conclude, pre-treatment with tBHQ could attenuate the spinal cord inflammatory response after SCI.

Protective effects of erythropoietin in traumatic spinal cord injury by inducing the Nrf2 signaling pathway activation.

BACKGROUND: Erythropoietin has demonstrated neuroprotective effects against traumatic spinal cord injury (SCI), but the underlying mechanisms remain unclear. The signaling pathway of an antioxidant transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2), has been shown to play an important role in protecting SCI-induced secondary spinal cord damage. This study was undertaken to explore the effect of recombinant human erythropoietin (rhEPO) on the activation of Nrf2 signaling pathway and secondary spinal cord damage in rats after SCI. METHODS: Adult male Sprague-Dawley rats were subjected to laminectomy at T8-T9 and compression with a vascular clip. Three groups were analyzed: (1) sham group, (2) SCI group, and (3) SCI + rhEPO group (n = 16 per group). In the SCI + rhEPO group, rhEPO was administered at a dose of 5,000 IU/kg at 30 minutes after SCI. Spinal cord samples were extracted at 72 hours after the trauma. RESULTS: As a result, we found that the treatment with rhEPO markedly up-regulated the messenger RNA expressions and activities of Nrf2 signaling pathway-related agents, including Nrf2, NAD(P)H:quinone oxidoreductase 1(NQO1), and glutathione S-transferase. The administration of rhEPO also significantly ameliorated the secondary spinal cord damage, as shown by a decreased severity of locomotion deficit, spinal cord edema, and apoptosis. CONCLUSION: Post-SCI rhEPO administration induces Nrf2-mediated cytoprotective response in the injured spinal cord, and this may be a mechanism whereby rhEPO improves the outcome following SCI.

Curcumin inhibits the increase of labile zinc and the expression of inflammatory cytokines after traumatic spinal cord injury in rats.

BACKGROUND: The present study aimed to investigate the effects of curcumin on the levels of spinal cord labile zinc (Zn) and inflammatory cytokines in rats after traumatic spinal cord injury (SCI). METHODS: Adult male Sprague-Dawley rats were subjected to laminectomy at T8-T9 and compression with a vascular clip. There were three groups: (a) sham group; (b) SCI group; and (c) SCI + curcumin group. We measured spinal labile Zn by N-(6-methoxy-8-quinolinyl)-4-methylbenzenesulfonamide (TSQ) fluorescence staining, inflammatory cytokines such as interleukin 1ß, interleukin-6, and tumor necrosis factor α by enzyme-linked immunosorbent assay, hindlimb locomotion function by Basso, Beattie, and Bresnahan rating, spinal cord edema by wet dry weight method, and apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling analysis. RESULTS: The results showed that SCI caused a significant increase in labile Zn and inflammatory cytokines in the injured rat spinal cord. Treatment with curcumin after SCI markedly downregulated the levels of these agents and ameliorated SCI-induced hindlimb locomotion deficits, spinal cord edema, and apoptosis. CONCLUSIONS: Curcumin treatment attenuates the increase of labile Zn and the expression of inflammatory cytokines in the injured spinal cord, and this may be a mechanism whereby curcumin improves the outcome after SCI.

Anti-inflammatory effects of curcumin in experimental spinal cord injury in rats.

AIM: Antioxidant transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) has been shown in our previous studies to play an important role in protection against spinal cord injury (SCI) induced inflammatory response. The objective of this study was to test whether curcumin, a novel Nrf2 activator, can protect the spinal cord against SCI-induced inflammatory damage. METHODS: Adult male Sprague-Dawley rats were subjected to laminectomy at T8-T9 and compression with a vascular clip. The spinal cords spanning the injury site about 0.8 cm were collected for testing. There were three groups: (a) sham group; (b) SCI group; and (c) SCI + curcumin group. We measured Nrf2 and nuclear factor kappa B (NF-κB) binding activities by electrophoretic mobility shift assay, concentrations of tumor necrosis factor-α, interleukin-1ß and interleukin-6 by enzyme-linked immunosorbent assay, hindlimb locomotion function by Basso, Beattie, and Bresnahan rating, spinal cord edema by the wet/dry weight method, and apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling analysis. RESULTS: Induction of the Nrf2 activity by curcumin markedly decreased NF-κB activation and inflammatory cytokines production in the injured spinal cord. Administration of curcumin also significantly ameliorated the secondary spinal cord damage, as shown by decreased severity of locomotion deficit, spinal cord edema, and apoptosis. CONCLUSION: Post-SCI curcumin administration attenuates the inflammatory response in the injured spinal cord, and this may be a mechanism whereby curcumin improves the outcome following SCI.

Induction of rat facial nerve regeneration by functional collagen scaffolds.

Nerve conduit provides a promising strategy for nerve regeneration, and the proper microenvironment in the lumen could improve the regeneration. Our previous work had demonstrated that linear ordered collagen scaffold (LOCS) could effectively guide the oriented growth of axons. Laminin is known as an important nerve growth promoting factor and can facilitate the growth cone formation. In addition, ciliary neurotrophic factor (CNTF) and brain-derived neurotrophic factor (BDNF) can effectively improve the nerve regeneration after nerve injuries. However, in practice, diffusion caused by the body fluids is the major obstacle in their applications. To retain CNTF or BDNF on the scaffolds, we produced collagen binding CNTF (CBD-CNTF), collagen binding BDNF (CBD-BDNF) and laminin binding CNTF (LBD-CNTF), laminin binding BDNF (LBD-BDNF) respectively. In this work, we developed laminin modified LOCS fibers (L × LOCS) by chemical cross-linking LOCS fibers with laminin. Collagen binding or laminin binding neurotrophic factors were combined with LOCS or L × LOCS, and then filled them into the collagen nerve conduit. They were found to guide the ordered growth of axons, and improve the nerve functional recovery in the rat facial nerve transection model. The combination of CNTF and BDNF greatly enhanced the facial nerve regeneration and functional recovery.