Involvement of peptidylarginine deiminase-mediated post-translational citrullination in pathogenesis of sporadic Creutzfeldt-Jakob disease

Peptidylarginine deiminases (PADs)-mediated post-translational citrullination processes play key roles in protein functions and structural stability through the conversion of arginine to citrulline in the presence of excessive calcium concentrations. In brain, PAD2 is abundantly expressed and can be involved in citrullination in disease. Recently, we have reported pathological characterization of PAD2 and citrullinated proteins in scrapie-infected mice, but the implication of protein citrullination in the pathophysiology in human prion disease is not clear. In the present study, we explored the molecular and biological involvement of PAD2 and the pathogenesis of citrullinated proteins in frontal cortex of patients with sporadic Creutzfeldt-Jakob disease (sCJD). We found increased expression of PAD2 in reactive astrocytes that also contained increased levels of citrullinated proteins. In addition, PAD activity was significantly elevated in patients with sCJD compared to controls. From two-dimensional gel electrophoresis and MALDI-TOF mass analysis, we found various citrullinated candidates, including cytoskeletal and energy metabolism-associated proteins such as vimentin, glial fibrillary acidic protein, enolase, and phosphoglycerate kinase. Based on these findings, our investigations suggest that PAD2 activation and aberrant citrullinated proteins could play a role in pathogenesis and have value as a marker for the postmortem classification of neurodegenerative diseases.     

Loss of long-term potentiation in the hippocampus after experimental subarachnoid hemorrhage in rats

Survivors of aneurysmal subarachnoid hemorrhage (SAH) often suffer from cognitive impairment such as memory loss. However, the underlying mechanisms of these impairments are not known. Long-term potentiation (LTP) of synapses in the hippocampus is generally regarded as a molecular substrate of memory. The purpose of this study was to examine the effect of SAH on LTP in the hippocampal Schaffer collateral (CA3–CA1) pathway in a rat model of SAH. We found SAH caused significant vasospasm of the middle cerebral artery (MCA) compared to saline injected or sham controls (P<0.001). Basic neurotransmission quantified as excitatory post synaptic and spike response from animals with SAH were significantly decreased as compared to naive controls (P<0.05). However, sham operated and saline injected controls showed similar amplitude as naive controls. This suggests that reduction in basic neurotransmission is due to blood in the subarachnoid space. Similarly, analysis of LTP demonstrated that naive, sham and saline controls have a 92±16%, 69±27% and 71±14% increase over the baseline in the average spike amplitude following high frequency stimulation (HFS), respectively. This indicates the presence of LTP (P<0.05). In contrast, the spike amplitude in animals of SAH returned to baseline level within 60 min post HFS indicating the absence of LTP. We conclude that SAH caused vasospasm of the MCA that was associated with disrupted basic neurotransmission and plasticity at CA3–CA1 synapses. These changes might be accountable for the memory loss in humans with SAH.     

Delivery of Factor VIII Gene into Skeletal Muscle Cells Using Lentiviral Vector

Purpose

This study was designed to investigate whether transduction of lentiviral vectors (LV) carrying human coagulation factor VIII (hFVIII) cDNA into skeletal muscle could increase circulating hFVIII concentrations.

Materials and Methods

A LV containing bacterial LacZ gene as a control or human FVIII gene was intramuscularly administered into the thigh muscle of 5 weeks old Sparague-Dawley rats. The plasma human FVIII concentration and neutralizing anti-FVIII antibodies were measured for up to 12 weeks in these experimental animals.

Results

The plasma human FVIII levels in the rats injected with LV carrying FVIII cDNA peaked at post-injection 1st week (5.19 ± 0.14 ng/mL vs. 0.21 ± 0.05 ng/mL in control rats , p < 0.05). Elevated hFVIII concentrations were maintained for 4 weeks (2.52 ± 0.83 ng/mL vs. 0.17 ± 0.08 ng/mL in control rats, p < 0.05) after a single intramuscular injection. In the Bethesda assay, neutralizing antibodies for FVIII protein were detected only in FVIII-LV injected rats by the 10th week, but not in control rats.

Conclusion

This study suggested that a single administration of an advanced generation LV carrying the human FVIII cDNA resulted in elevation of FVIII level in immune competent rats, and that this gene transfer approach to the skeletal muscle could be an effective tool in treatment of hemophilia A.     

Standardized combination antibiotic treatment of Mycobacterium avium complex lung disease

Purpose

The optimal treatment regimen for Mycobacterium avium complex (MAC) lung disease has not yet been fully established. We evaluated the efficacy of standardized combination antibiotic therapy and the factors that might affect unfavorable microbiologic responses in patients with MAC pulmonary disease.

Materials and Methods

This retrospective study reviewed data from 96 patients (56 females; median age 59 years) treated with newly diagnosed MAC lung disease between January 2003 and December 2006.

Results

All patients received standardized combination antibiotic therapy, consisting of clarithromycin, rifampicin, and ethambutol. Streptomycin was additionally given in 72 patients (75%) for a median duration of 4.5 months. The overall favorable microbiologic response rate was 79% (76/96); 20 patients (21%) had unfavorable microbiologic responses, including failure to sputum conversion (n = 13), relapse (n = 3), and MAC-related death (n = 4). A positive sputum acid-fast bacillus smear at the start of treatment was an independent predictor of an unfavorable microbiologic response.

Conclusion

Standardized combination antibiotic therapy consisting of clarithromycin, rifampicin, and ethambutol with or without initial use of streptomycin is effective in treating patients with newly diagnosed MAC lung disease.     

Comparisons of the effects of stent eccentricity on the neointimal hyperplasia between sirolimus-eluting stent versus paclitaxel-eluting stent

Purpose

Previous studies suggested that asymmetric stent expansion did not affect suppression of neointimal hyperplasia (NIH) after sirolimus-eluting stents (SES) implantation. The aim of this study was to evaluate the effects of stent eccentricity (SE) on NIH between SES versus paclitaxel-eluting stents (PES) using an intravascular ultrasound (IVUS) analysis from the randomized trial.

Materials and Methods

Serial IVUS data were obtained from Post-stent Optimal Expansion (POET) trial, allocated randomly to SES or PES. Three different SE (minimum stent diameter divided by maximum stent diameter) were evaluated; SE at the lesion site with maximal %NIH area (SE-NIH), SE at the minimal stent CSA [SE-minimal stent area (SE-MSA)], and averaged SE through the entire stent (SE-mean). We classified each drug-eluting stents (DES) into the concentric (≥ mean SE) and eccentric groups (< mean SE) based on the mean value of SE.

Results

Among 301 enrolled patients, 233 patients [SES (n = 108), PES (n = 125)] underwent a follow-up IVUS. There was no significant correlation between %NIH area and SE-NIH (r = - 0.083, p = 0.391) or SE-MSA (r = - 0.109, p = 0.259) of SES. However, SE-NIH of PES showed a weak but significant correlation with %NIH area (r = 0.269, p < 0.01). As to the associations between SE-mean and NIH volume index, SES revealed no significant correlation (r = - 0.001, p = 0.990), but PES showed a weak but significant correlation (r = 0.320, p < 0.01). However, there was no difference in the restenosis rate between the eccentric versus concentric groups of both DES.

Conclusion

This study suggests that lower SE of both SES and PES, which means asymmetric stent expansion, may not be associated with increased NIH.     

Protection elicited by two glutamine auxotrophs of Mycobacterium tuberculosis and in vivo growth phenotypes of the four unique glutamine synthetase mutants in a murine model

We generated four individual glutamine synthetase (GS) mutants (DeltaglnA1, DeltaglnA2, DeltaglnA3, and DeltaglnA4) and one triple mutant (DeltaglnA1EA2) of Mycobacterium tuberculosis to investigate the roles of GS enzymes. Subcutaneous immunization with the DeltaglnA1EA2 and DeltaglnA1 glutamine auxotrophic mutants conferred protection on C57BL/6 mice against an aerosol challenge with virulent M. tuberculosis, which was comparable to that provided by Mycobacterium bovis BCG vaccination.     

Decursin, an active compound isolated from Angelica gigas, inhibits fat accumulation, reduces adipocytokine secretion and improves glucose tolerance in mice fed a high-fat diet

Decursin (De), an active component of Angelica gigas, is known to exert anticancer and neuroprotective effects. However, its antiobesity and antidiabetic potential has not yet been investigated. This study evaluated the antiobesity effect of decursin, particularly focusing on its ability to inhibit adipocyte differentiation in 3T3-L1 cells. Decursin treatment resulted in the inhibition of adipocyte differentiation and the expression of fatty acid synthase. The study further investigated these antiobesity effects using mice fed a normal diet (ND), a high-fat diet (HFD) and a HFD plus decursin 200 mg/kg diet (HFD + De) for 7 weeks. Mice administered HFD plus decursin showed a drastic decrease in weight gain, triglyceride content, total cholesterol content and fat size compared with those that received the HFD alone; this was observed despite similar quantities of total food intake. Furthermore, decursin improved glucose tolerance in mice fed a HFD. Finally, administration of decursin along with the HFD significantly reduced the secretion of HFD-induced adipocytokines such as leptin, resistin, IL-6 and MCP-1. These results suggest that decursin might be useful for the treatment of obesity and diabetes.     

Imatinib mesylate discontinuation in patients with chronic myeloid leukemia who have received front-line imatinib mesylate therapy and achieved complete molecular response

The aims were to investigate the feasibility of imatinib mesylate (IM) discontinuation in chronic myeloid leukemia patients who were initially treated with IM and achieved complete molecular response (CMR). Fourteen patients were included. Ten were relapsed within 9.5 months after discontinuation of IM. All 7 patients with high Sokal risk were relapsed. The probability of CMR persistence at 1-year was 28.6%. All relapsed patients were still responsive to IM. A high Sokal risk and delayed acquisition of CMR were associated with relapse. IM discontinuation in patients achieved CMR after treatment with front-line IM might be feasible. Further studies are warranted.