Critical Role of p38 in Spinal Cord Injury by Regulating Inflammation and Apoptosis in a Rat Model.

STUDY DESIGN: To evaluate the effect of p38 pathway on spinal cord injury (SCI), a rat model of SCI was performed. OBJECTIVE: We determined the effect of p38 on SCI and SCI related inflammation, apoptosis, and autophagy. SUMMARY OF BACKGROUND DATA: SCI is a severe clinical problem worldwide. It is difficult to prevent cell necroptosis and promote the survival of residual neurons after SCI. p38, a class of mitogen-activated protein kinases, its effect on SCI and SCI related inflammation, apoptosis, and autophagy have not been studied very well. METHODS: The rats were randomly divided into the following four groups: the sham-operated (sham) group, the SCI group, the SCI + vehicle group, and the SCI + SB203580 (10 mg/kg) group. The p38 inhibitor SB203580 was administered by oral (10 mg/kg/d) gavage once per day for 14 days. Neurological recovery was assessed using the Basso, Beattie, and Bresnahan locomotion rating scale. Apoptosis, autophagy, and inflammation related proteins were measured by enzyme-linked immunosorbent assay kits or western blotting. RESULTS: Our results showed that p38 was upregulated after SCI from day 3, which was paralleled with the levels of its proteins ATF-2, suggesting an increase in p38 activity. Our results showed administration of SB203580 attenuated histopathology and promoted locomotion recovery in rats after SCI. SB203580 administration significantly inhibited inflammatory cytokines levels as well as the inflammation signaling pathway. SB203580 administration also modulated the apoptosis and autophagy signaling pathway. CONCLUSION: Our findings suggest that p38 inhibitor SB203580 treatment alleviates secondary SCI by inhibiting inflammation and apoptosis, thereby promoting neurological and locomoter functional recovery, thus suggest the important role of p38 in neuronal protection after SCI. LEVEL OF EVIDENCE: N/A.

Circular RNA profile in coronary artery disease.

Circular RNAs (circRNAs) are potential biomarkers and therapeutic targets of coronary artery disease due to their high stability, covalently closed structure. And implied roles in gene regulation. The aim of this study was to identify and characterize circRNAs from human coronary arteries. Epicardial coronary arteries were removed during the autopsy of an 81-year-old man who died from heart attack. The natural history and histological classification of atherosclerotic lesions in coronary artery segments were analyzed by hematoxylin and eosin staining, and their circRNA expression profiles were characterized by RNA sequencing. RNA sequencing identified 1259 annotated and 381 novel circRNAs. Combined with the results of histologic examination, intersection analysis identified 54 upregulated and 12 downregulated circRNAs, representing 4.0% of the total number. Coronary artery segments with or without severe atherosclerosis showed distinctly different circRNA profiles on the basis of hierarchical clustering. Our results suggest that these 66 circRNAs contribute to the pathology underlying coronary artery atherosclerosis and may serve as diagnostic or therapeutic targets in coronary artery disease.

Tetramethylprazine attenuates myocardial ischemia/reperfusion injury through modulation of autophagy.

The current study aimed to investigate the effects of tetramethylprazine (TMP) on myocardial ischemia/reperfusion (MI/R) injury and its underlying mechanisms. MI/R rat model and hypoxia/reoxygenation (H/R) cardiomyocytes model were established. CK level and LDH activity were detected to evaluate MI/R and H/R injury. Cell viability was determined by cell counting kit-8 (CCK-8) assay. Cell apoptosis were identified by flow cytometry and autophagy were detected by western blot. Treatment with TMP significantly reduced CK level and LDH activity and decreased myocardial infarct size in MI/R rats. TMP reduced autophagy dysfunction induced by MI/R. Moreover, TMP treatment decreased H/R-induced injury and attenuated autophagy dysfunction in cardiomyocytes. Inhibiting autophagic flux with chloroquine (CQ) decreased the cardioprotection exerted by TMP in vivo and in vitro. Additionally, the effects of TMP on the modulation of autophagy were inhibited by LY294002 (a PI3K inhibitor) in H/R cardiomyocytes. Our findings suggested TMP exerted cardioprotection against MI/R injury by decreasing Beclin-1 associated autophagy dysfunction through PI3K pathway.

Evaluation of left ventricular function by three-dimensional speckle-tracking echocardiography in patients with myocardial bridging of the left anterior descending coronary artery.

BACKGROUND: To understand the influence of myocardial bridging (MB) on left ventricular (LV) function, myocardial function was studied in patients with MB of the left anterior descending coronary artery (LAD) using three-dimensional speckle-tracking echocardiography (STE). METHODS: Left anterior descending coronary artery MB was diagnosed by coronary angiography in 82 subjects. Patients were divided into three groups according to the percentage of systolic narrowing of the compressed segment: 30% to 49% was defined as group I (24 patients), 50% to 74% as group II (28 patients), and ≥75% as group III (30 patients). Thirty gender- and age-matched normal subjects were included as controls. Left ventricular myocardial deformation was estimated by three-dimensional STE. RESULTS: Left ventricular ejection fractions were normal in all patients, but diastolic function was impaired in groups II and III (E/E' ratio, 9 ± 3 and 10 ± 3, respectively). The amplitudes of longitudinal strain (LS) and area strain (AS) of the LAD territory was significantly reduced in groups II and III compared with controls and group I (LS, -15 ± 2% and -12 ± 1% vs -19 ± 2% and -18 ± 2%; AS, -22 ± 2% and -13 ± 2% vs -33 ± 4% and -33 ± 3%; P < .0001), but the amplitudes of circumferential and radial strain showed no intergroup differences. Longitudinal strain and AS were significantly lower in patients with fractional flow reserve < 0.75 than in those with fractional flow reserve ≥ 0.75 (P < .0001), with relative preservation of circumferential and radial strain. The severity of LAD compression was significantly associated with AS and LS of the LAD territory (r = -0.92 and r = -0.84, respectively, P < .0001), but the correlations with circumferential and radial strain were modest (r = -0.36 and r = -0.32, respectively, P < .05). CONCLUSIONS: With the increasing severity of systolic compression of the mural coronary artery, LV diastolic function and regional systolic deformation (AS and LS) of the MB perfusion territory were reduced. Three-dimensional STE can detect subtle myocardial dysfunction in patients with MB.

BDNF-mediated modulation of glycine transmission on rat spinal motoneurons.

BDNF has a widespread distribution in the central and peripheral nervous systems, suggesting that BDNF may play a role in the regulation of motor control. However, the direct actions of BDNF on the motoneurons and their underlying mechanisms are still largely unknown to date. Therefore, by using whole-cell patch clamp recordings, quantitative RT-PCR and immunocytochemistry, the present study was designed to investigate the effects of BDNF on electrical activity and glycinergic transmission on the motoneurons and the underlying receptor mechanism. The results reveal: (i) BDNF did not produce a direct excitatory or inhibitory effect on the motoneurons; (ii) BDNF dose-dependently increased the glycinergic transmission on the motoneurons; (iii) glycinergic transmission on motoneurons was a direct postsynaptic effect; (iv) BDNF-induced enhancement of the glycinergic transmission was mediated by the activation of TrkB receptors; and (v) BDNF and its receptors TrkB had an extensive expression in the motoneurons. These results suggest that BDNF is directly involved in the regulation of glycinergic transmission on the motoneurons through postsynaptic TrkB receptors. Considering that the glycinergic synaptic transmission of motoneurons mainly comes from Renshaw cells, the important inhibitory interneurons of spinal cord, we speculate that BDNF may play an important role in the information integration in the spinal cord and participate in the sensitivity of motoneurons.

Tissue kallikrein is related to the severity of coronary artery disease.

BACKGROUND: The impairment of the tissue kallikrein (KLK1)-kinin system (KKS) may result in atheroma development. However, it remains unclear if the KKS correlates with coronary artery disease (CAD). METHODS: KLK1, VEGF and hs-CRP plasma levels were measured in 100 patients newly diagnosed with CAD and 33 CAD-free controls. Patients were followed-up for the incidence of major adverse cardiovascular events (MACE) for 8months to 2y. Gene expression of KLK1, CD105 and CD68 was assessed in human coronary endarterectomy specimens. RESULTS: Patients with CAD and acute coronary syndrome (ACS) had significantly elevated KLK1 levels. In addition, the concentration of hs-CRP was increased in ACS patients. A strong positive correlation between plasma KLK1 and the severity of CAD was also demonstrated, suggesting that high KLK1 levels are an independent predictor for CAD. MACE during follow-up significantly correlated with KLK1 levels in the ACS group. Unstable coronary plaques demonstrated markedly increased KLK1 levels, macrophage infiltration and high microvessel density. Additionally, KLK1 staining primarily colocalized with macrophages. CONCLUSIONS: In the present study, plasma KLK1 levels were a useful predictor for the presence and extent of CAD. More extensive studies are, however, necessary in order to validate these findings.

Enhancing the bioactivity of Poly(lactic-co-glycolic acid) scaffold with a nano-hydroxyapatite coating for the treatment of segmental bone defect in a rabbit model.

PURPOSE: Poly(lactic-co-glycolic acid) (PLGA) is excellent as a scaffolding matrix due to feasibility of processing and tunable biodegradability, yet the virgin scaffolds lack osteoconduction and osteoinduction. In this study, nano-hydroxyapatite (nHA) was coated on the interior surfaces of PLGA scaffolds in order to facilitate in vivo bone defect restoration using biomimetic ceramics while keeping the polyester skeleton of the scaffolds. METHODS: PLGA porous scaffolds were prepared and surface modification was carried out by incubation in modified simulated body fluids. The nHA coated PLGA scaffolds were compared to the virgin PLGA scaffolds both in vitro and in vivo. Viability and proliferation rate of bone marrow stromal cells of rabbits were examined. The constructs of scaffolds and autogenous bone marrow stromal cells were implanted into the segmental bone defect in the rabbit model, and the bone regeneration effects were observed. RESULTS: In contrast to the relative smooth pore surface of the virgin PLGA scaffold, a biomimetic hierarchical nanostructure was found on the surface of the interior pores of the nHA coated PLGA scaffolds by scanning electron microscopy. Both the viability and proliferation rate of the cells seeded in nHA coated PLGA scaffolds were higher than those in PLGA scaffolds. For bone defect repairing, the radius defects had, after 12 weeks implantation of nHA coated PLGA scaffolds, completely recuperated with significantly better bone formation than in the group of virgin PLGA scaffolds, as shown by X-ray, Micro-computerized tomography and histological examinations. CONCLUSION: nHA coating on the interior pore surfaces can significantly improve the bioactivity of PLGA porous scaffolds.

[Metalloproteinase Tolloid-like 1 gene mutation in Chinese patients with sporadic congenital heart diseases].

OBJECTIVE: To explore whether there are gene mutations of Tolloid-like 1 (TLL-1) gene in Chinese patients with sporadic congenital heart disease (CHD). METHODS: One hundred and fifteen patients with sporadic CHD were selected as CHD group. One hundred and two age and gender-matched healthy people were recruited as control group. After amplifying the exon 10 of the TLL-1 gene by polymerase chain reaction, the polymerase chain reaction products were purified, sequenced and analyzed in order to investigate the TLL-1 gene mutation. RESULTS: An insertion mutation of base A in the exon 10 of TLL-1 gene was identified in 7 out of 115 CHD patients, including 3 patients with atrial septal defect, 2 patients with ventricular septal defect, 1 patients with patent ductus arteriosus and 1 patients with complex CHD, the total mutation rate was 6.1% in CHD group and 0 in control group (P < 0.01). CONCLUSIONS: TLL-1 gene mutation with an insertion mutation of base A in exon 10 is often in Chinese patients with various CHD. The underlying pathogenesis between TLL-1 gene mutation and occurrence of congenital heart disease in Chinese people remains unclear and warrants further investigations.

[Preliminary exploration of transcription factor Nkx2.5 mutations and congenital heart diseases].

OBJECTIVE: To explore the association between the gene mutation of transcription factor Nkx2.5 and Chinese patients with congenital heart disease (CHD). METHODS: Polymerase chain reaction (PCR) and DNA sequencing were used to check 99 CHD patients and 90 normal control subjects from the Zhong Da Hospital of Southeast University. After amplifying the exons 1 of the Nkx2.5 gene by PCR, we purified the PCR products and conducted the sequencing reaction, analyzed the mutation screening of the exon 1 of the Nkx2.5, investigated whether or not the Nkx2.5 is related with the CHD in Chinese population. RESULTS: A mutation (A239G) in the exon 1 of the Nkx2.5 was identified in 3 of 90 normal control subjects and 12 of 99 CHD patients, including 3 of 24 with VSD, 7 of 35 with ASD, 1 of 13 with PS and 1 of 21 with PDA. CONCLUSION: There are some associations between the Nkx2.5 gene mutation and occurrence of congenital heart disease in Chinese people.

Injectable block copolymer hydrogels for sustained release of a PEGylated drug.

The paper employs the spontaneous physical gelling property of a biodegradable polymer in water to prepare an injectable sustained release carrier for a PEGylated drug. A series of thermogelling PLGA-PEG-PLGA triblock copolymers were synthesized. The PEGylated camptothecin (CPT) was also prepared and employed as the model of a PEGylated drug, and the solubility of this hydrophobic drug was significantly enhanced to over 150mg/mL. The model drug was completely entrapped into the polymeric hydrogel, and the sustained release lasted for 1 month. The mechanism of the sustained release was diffusion-controlled at the first stage and then was the combination of diffusion and degradation at the late stage. In vivo anti-tumor tests in mice further confirmed the efficacy of the model PEGylated drug released from the hydrogel. This work also revealed the specificity of the PEGylated drug in such a kind of carrier systems by decreasing the critical gelling temperature and increasing the viscosity of the sol. Due to the very convenient drug formulation and highly tunable release rate, an injectable carrier platform for PEGylated drugs is thus set up.

Dynamics of primary events in the photocycle of excited bacteriorhodopsin.

Transient dynamic behavior of the excited bacteriorhodopsin (BR), which was isolated from the strain H. salinarum, was studied at excitation wavelength from 585 to 639 nm. With the one-color femtosecond (fs) pump-probe technique, we revealed the primary events in BR's photocycle that took place in an ultrafast time scale. From the analysis of the decay components of the dynamical traces, it was evident that the isomerization of the retinal chromophore in BR and the intermediate J's formation occurred within 500 fs. BR exhibited pH-dependent dynamical behaviors. When the medium pH was between 5 and 9, the BR ultrafast dynamics has no obvious change. In contrast, the dynamical curves were obviously affected when the pH was out of that region.

[Preparation of liposome containing bacteriorhodopsin with natural preferred orientation of its transient photoresponse].

Bacteriorhodopsin is a membrane protein of halobacteria and functions as a light-driven protein pump. After we isolated bR from cultured halobacteria, bR was mixed with amphiphilic DPPC under different pH. The liposomes were formed after sonication. The remaining biological activity of bR as a proton pump was then verified and pulsed-light-induced proton movement was detected, while liposomes were observed via TEM and light scattering. Although there was no noticeable difference in morphologies of both vesicles formed at pH=2.5 and pH=7.0, the orientations of bR in both liposomes were found to be opposite under these two conditions. This experiment confirmed that the protein bR, when self-assembling into liposomes under acid medium, kept the similar orientation as in the natural plasmid membrane. Such a normal-orientation was, however, different from most of reports in the literature about liposomes prepared under normal neutral conditions.