2,5-Dimethyl-celecoxib induces early termination of inflammatory responses by transient macrophage accumulation and inhibits the progression of cardiac remodeling in a mouse model of cryoinjury-induced myocardial infarction

In our previous study, we reported that 2, 5-dimethyl-celecoxib (DM-C), a derivative of celecoxib, prevents cardiac remodeling in different mouse models of heart failure, including myocardial infarction (MI). The inflammatory response after MI affects the progression of cardiac remodeling, wherein the immune cells, mainly macrophages, play crucial roles. Therefore, we evaluated the effect of DM-C on macrophages in a cryoinjury-induced myocardial infarction (CMI) mouse model. We observed that DM-C attenuated the deterioration of left ventricular ejection fraction and cardiac fibrosis 14 d after CMI. Gene expression of pro-inflammatory cytokines at the infarct site was reduced by DM-C treatment. Analysis of macrophage surface antigens revealed that DM-C induced transient accumulation of macrophages at the infarct site without affecting their polarization. In vitro experiments using peritoneal monocytes/macrophages revealed that DM-C did not directly increase the phagocytic ability of the macrophages but increased their number, thereby upregulating the clearance capacity. Moreover, DM-C rapidly excluded the cells expressing necrotic cell marker from the infarct site. These results suggested that DM-C enhanced the clearance capacity of macrophages by transiently increasing their number at the infarct site, and terminated the escape from the inflammatory phase earlier, thereby suppressing excessive cardiac remodeling and ameliorating cardiac dysfunction.

Impact of sarcopenia on long-term survival after cardiac surgery for end-stage renal disease patients

BACKGROUND

The long-term mortality of end-stage renal disease (ESRD) patients is still unsatisfactory. Therefore, long-term risk assessments in ESRD patients undergoing cardiac surgery are needed. Recently, sarcopenia is major concern in cardiac surgery because of its association with poor long-term survival. However, the impact of sarcopenia on the long-term survival of ESRD patients undergoing cardiac surgery is not well understood.

METHODS

Eighty-two ESRD patients who underwent elective cardiac surgery were enrolled. Sarcopenia was identified based on noncontrast abdominal computed tomography. The impact of preoperative and intraoperative factors on long-term survival was investigated.

RESULTS

Forty-three patients (52%) were diagnosed with sarcopenia. The in-hospital mortality rate was 4.9%. The 5-year overall survival rate was 48%. The multivariate analyses revealed that STS score ≥ 4 (odds ratio, 6.0; confidence interval, 2.5-14.7; p < 0.01) and presence of sarcopenia (odds ratio, 2.4; confidence interval, 1.3-4.5; p  =  0.03) were independent risk factors for overall survival. The 5-year survival rates of low-risk (Society of Thoracic Surgeons score of < 4) patients without sarcopenia, low-risk with sarcopenia, more than intermediate-risk (Society of Thoracic Surgeons score of ≥ 4) without sarcopenia, and more than intermediate-risk with sarcopenia groups were 80%, 51%, 50%, and 26%, respectively.

CONCLUSIONS

Among the ESRD patients, the low risk without sarcopenia group showed an excellent long-term survival, in contrast to more than intermediate-risk patients with sarcopenia, who can expect poor long-term survival. Preoperative assessment of sarcopenia in addition to the surgical risk score can be useful in developing a therapeutic strategy.

2,5-Dimethylcelecoxib attenuates cardiac fibrosis caused by cryoinjury-induced myocardial infarction by suppressing the fibroblast-to-myofibroblast transformation via inhibition of the TGF-β signaling pathway

We previously reported that 2,5-dimethylcelecoxib (DM-C), a derivative of celecoxib, lacks cyclooxygenase-2 inhibitory effects and suppresses cardiac remodeling by activating glycogen synthase kinase-3 (GSK-3). However, it remains unclear whether DM-C attenuates fibroblast-to-myofibroblast transformation (FMT), which plays a key role in cardiac fibrosis. Therefore, we evaluated the effect of DM-C on FMT using a cryoinjury-induced myocardial infarction (CMI) mouse model. We found that DM-C attenuated the deterioration of left ventricular ejection fraction after CMI by decreasing cardiac fibrosis. Analysis of the expression level of α-smooth muscle actin (α-SMA), a marker for myofibroblasts, indicated that DM-C decreased FMT at the cardiac injury site. To investigate the mechanism by which DM-C attenuated FMT, fibroblasts obtained from the heart were stimulated with TGF-β to induce FMT, and the effect of DM-C was analyzed. DM-C suppressed the expression of α-SMA and the phosphorylation levels of Smad 2/3 and GSK-3, indicating that DM-C suppressed α-SMA expression by inhibiting the transforming growth factor (TGF)-β signaling pathway via activation of GSK-3. DM-C decreased the expression of collagen, connective tissue growth factor (CTGF) and Snail, which are also known to accelerate cardiac fibrosis. These results suggested that DM-C attenuated cardiac fibrosis by suppressing FMT at the injured site after CMI by inhibiting the TGF-β signaling pathway via activation of GSK-3. Thus, DM-C has potential against cardiac disease as a novel anti-fibrotic agent.

Significant delayed aortic dilatation after tetralogy of Fallot repair: a case report

Background

Aortic dilatation may occur in some patients even after complete repair of tetralogy of Fallot (TOF). The progression rate of the aortic diameter is so slow, and the incidence of aortic dissection is so low that it is suspected that frequent imaging of the aorta may not be necessary.

Case presentation

We describe an asymptomatic 41-year-old man with hypertension in whom aortic dilatation was accidentally discovered 39 years after TOF repair. He underwent ambulatory follow-up without any difficulty for 21 years after the repair. Contrast-enhanced computed tomography revealed significant aortic dilatation (maximum diameter of 88 mm at the sinus of Valsalva), and echocardiography revealed severe aortic regurgitation, which seemed to progress during the last 18 years without any evaluation or follow-up. The Bentall procedure was successfully performed using a valved graft, under deep hypothermic circulatory arrest with antegrade cerebral perfusion, and his postoperative course was uneventful. Histopathological examination of ascending aorta specimens revealed severe cystic medial degeneration.

Conclusions

Keeping in mind that a patient with rapid progression of the aortic dilatation after TOF repair exist, periodic follow-up for evaluation of the aorta is essential in patients with TOF.

Bacillus thermoglucosidasius sp. nov., a New Species of Obligately Thermophilic Bacilli

A group of 6 strains of obligately thermophilic spore-formers is described as a novel species named Bacillus thermoglucosidasius. The strains are strictly aerobic, neutrophilic, amylolytic, Gram-positive, azide sensitive, produce terminally swollen sporangia and exo-oligo-1,6-glucosidase in large amounts. Strain KP 1006 (DSM 2542) is designated as the type strain. Growth occurs at temperatures from 42°C to 69°C with an optimum at 61-63°C, and at an initial pH of 6.5-8.5. The guanine + cytosine content of DNA, estimated by thermal DNA denaturation, is 45-46 mol%.

Bacillus thermoglucosidius alpha-glucosidase. Temperature dependence of activity and stability

A p-nitrophenyl-alpha-D-glucopyranoside-hydrolyzing alpha-glucosidase from an obligate thermophile, Bacillus thermoglucosidius KP 1006, gave a triphasic relationship at pH 6.8 in the van't Hoff plot of Km, in the Arrhenius plot of the first order rate constant of inactivation with 0.1% sodium dodecyl sulfate, and in the logarithmic plot of the maximal fluorescence intensity at 346 nm versus reciprocal of temperature. The respective plots exhibited two breaks at 40 and 61 degrees C, 43 and 62 degrees C, and 40 and 61 degrees C. However, the Arrhenius plot of the molecular activity at pH 6.8 had a single discontinuity at 64 degrees C. These findings, together with thermodynamic quantities for the enzyme, suggest that the thermal conformation changes in the enzyme protein occur around 40--43 degrees C and 61--64 degrees C. The Arrhenius plot of the rate constant of heat inactivation at pH 6.8 was bent at 73 degrees C. Thermodynamic data indicate that the enzyme is transformed from a heat stable form into a heat unstable form at 73 degrees C with temperature elevation. The critical points localized near the minimum, optimum, and maximum temperatures (40, 60, and 72 degrees C) of the cell growth, respectively.

Purification and properties of extracellular alpha-glucosidase of a thermophile, Bacillus thermoglucosidus KP 1006

An extracecular alpha-glucosidase (alpha-D-glucoside glycohydrolase, EC 3.2.1.20) of a thermophile, Bacillus thermoglucosidius KP 1006, was purified about 350-fold. The purified enzyme had a specific activity of 164 mumol of p-nitrophenyl-alpha-D-glucopyranoside hydrolyzed per min at 60 degrees C and pH 6.8 per mg of protein. The molecular weight was estimated at 55 000. The pH and temperature optima for activity were 5.0--6.0 and 75 degrees C, respectively. Below 40 degrees C, the activity was less than 4.5% of the optimym. The enzyme showed a high specificity for alpha-D-glucopyranoside. The maximal hydrolyzing velocity per substrate diminished in the order: phenyl-alpha-D-glucopyranoside, p-nitrophenyl-alpha-D-glucopyranoside, isomaltose, methyl-alpha-glycopyranoside. The respective Km values were 3.0, 0.23, 3.2 and 27 mM. The activity was trace for turanose, and not detectable for sucrose, trehalose, raffinose, melezitose, maltose, maltotriose, phenyl-alpha-D-maltoside, dextran, dextrin and starch. Tris, p-nitrophenyl-alpha-D-xylopyranoside, glucose and glucono-delta-lactone blocked competitively the enzyme with respect to p-nitrophenyl-alpha-D-glucopyranoside. The Ki values were 0.12, 0.14, 2.2 and 2.4 mM, respectively. The activity was affected by heavy metal ions, but insensitive to EDTA, p-chloromercuribenzoate and iodoacetate. The enzyme was stable up to 60 degrees C, and inactivated rapidly at temperatures beyond 72 degrees C. The pH range for stability was 4.0--11.0 at 31 degrees C, and 6.0--8.5 at 55.5 degrees C. At 25 degrees C, the enzyme failed to be inactivated in 45% ethanol, in 7.2 M urea, and in 0.06% sodium dodecyl sulfate, but the tolerance was extremely reduced at 60 degrees C.

Production of extracellular alpha-glucosidase by a thermophilic Bacillus species

Production of extracellular alpha-glucosidase was studied with strain KP 1006 of a new species of thermophilic Bacillus, which was isolated from soil samples by enrichment at 65 C. alpha-Glucosidase production was maximum at 60 C and at an initial pH of 6.5. The final enzyme yield was increased by starch, maltose, glycerol, peptone, and yeast extract but reduced by acetate and gluconate, alpha-Glucosidase was formed in the cytoplasm and accumulated as a large pool during the logarithmic growth phase. At a midpoint of this period, the enzyme appeared in the culture broth, and its level increased until the end of the stationary phase.