Protective role of insulin-like growth factor-1 receptor in endothelial cells against unilateral ureteral obstruction-induced renal fibrosis

Insulin-like growth factor-1 receptor (IGF-1R) can regulate vascular homeostasis and endothelial function. We studied the role of IGF-1R in oxidative stress-induced endothelial dysfunction. Unilateral ureteral obstruction (UUO) was performed in wild-type (WT) mice and mice with endothelial cell (EC)-specific IGF-1R knockout (KO). After UUO in endothelial IGF-1R KO mice, endothelial barrier dysfunction was more severe than in WT mice, as seen by increased inflammatory cell infiltration and vascular endothelial (VE)-cadherin phosphorylation. UUO in endothelial IGF-1R KO mice increased interstitial fibroblast accumulation and enhanced extracellular protein deposition as compared with the WT mice. Endothelial barrier function measured by transendothelial migration in response to hydrogen peroxide (H2O2) was impaired in ECs. Silencing IGF-1R enhanced the influence of H2O2 in disrupting the VE-protein tyrosine phosphatase/VE-cadherin interaction. Overexpression of IGF-1R suppressed H2O2-induced endothelial barrier dysfunction. Furthermore, by using the piggyBac transposon system, we expressed IGF-1R in VE cells in mice. The expression of IGF-1R in ECs also suppressed the inflammatory cell infiltration and renal fibrosis induced by UUO. IGF-1R KO in the VE-cadherin lineage of bone marrow cells had no significant effect on the UUO-induced fibrosis, as compared with control mice. Our results indicate that IGF-1R in the endothelium maintains the endothelial barrier function by stabilization of the VE-protein tyrosine phosphatase/VE-cadherin complex. Decreased expression of IGF-1R impairs endothelial function and increases the fibrosis of kidney disease.

Predicting eye fixations with higher-level visual features

Saliency map and object map are the two contrasting hypotheses for the mechanisms utilized by the visual system to guide eye fixations when humans are freely viewing natural images. Most computational studies define saliency as outliers of distributions of low-level features, and propose saliency as an important factor for predicting eye fixations. Psychophysical studies, however, suggest that high-level objects predict eye fixations more accurately and the early saliency only has a minor effect. But this view has been challenged by a study which shows opposite results, suggesting that the role of object-level features needs further investigations. In addition, little is known about the role of intermediate features between the low-level and the object-level features. In this paper, we construct two models based on mid-level and object-level features, respectively, and compare their performances against those based on low-level features. Quantitative evaluation on three benchmark natural image fixation data sets demonstrates that the mid-level model outperforms the state-of-the-art low-level models by a significant margin and the object-level model is inferior to most low-level models. Quantitative evaluation on a video fixation data set demonstrates that both the mid-level and object-level models outperform the state-of-the-art low-level models, and the latter performs better under three out of four standard metrics. When combined together the two proposed models achieve even higher performance. However, incorporating the best low-level model yields negligible improvements on all of the data sets. Taken together, these results indicate that higher level features may be more effective than low-level features for predicting eye fixations on natural images in the free viewing condition.

Impaired integrin β3 delays endothelial cell regeneration and contributes to arteriovenous graft failure in mice

OBJECTIVE

Neointima formation is associated with stenosis and subsequent thrombosis in arteriovenous grafts (AVGs). A role of integrin β3 in the neointima formation of AVGs remains poorly understood.

APPROACH AND RESULTS

In integrin β3(-/-) mice, we found significantly accelerated occlusion of AVGs compared with the wild-type mice. This is caused by the development of neointima and lack of endothelial regeneration. The latter is a direct consequence of impaired functions of circulating angiogenic cells (CACs) and platelets in integrin β3(-/-) mice. Evidence suggests the involvement of platelet regulating CAC homing to and differentiation at graft sites via transforming growth factor-β1 and Notch signaling pathway. First, CACs deficient of integrin β3 impaired adhesion activity toward exposed subendothelium. Second, platelets from integrin β3(-/-) mice failed to sufficiently stimulate CACs to differentiate into mature endothelial cells. Finally, we found that transforming growth factor-β1 level was increased in platelets from integrin β3(-/-) mice and resulted in enhanced Notch1 activation in CACs in AVGs. These results demonstrate that integrin β3 is critical for endothelial cell homing and differentiation. The increased transforming growth factor-β1 and Notch1 signaling mediates integrin β3(-/-)-induced AVG occlusion. This accelerated occlusion of AVGs was reversed in integrin β3(-/-) mice transplanted with the bone marrow from wild-type mice.

CONCLUSIONS

Our results suggest that boosting integrin β3 function in the endothelial cells and platelets could prevent neointima and thrombosis in AVGs.

Emergency treatment of splenic injury in a novel mobile minimally invasive interventional shelter following disaster: a feasibility study

Background

There has been an increase in natural disasters in recent years, which leads to a great number of injuries and deaths. It still remains an unsolved problem to treat patients with vascular injury of solid organs effectively following natural disasters, but on-spot emergency interventional transcatheter arterial embolization (TAE) has been highly recommended to cure serious vascular injury of solid organs nowadays. Spleen is the most vulnerable abdominal organ, severe arterial hemorrhage of which can cause death if untreated timely. In this research, we aimed to study the possibility of performing emergency surgical intervention in mobile minimally invasive interventional shelter for splenic injury in the case of natural disasters.

Methods

First, the mobile minimally invasive interventional shelter was unfolded in the field, and then disinfection and preoperative preparation were performed immediately. Eight large animal models of splenic injury were created, and angiograms were performed using a digital subtraction angiography machine in the mobile minimally invasive interventional shelter, and then the hemostatic embolizations of injured splenic artery were performed following the established convention of rapid intervention therapy. The operating time was recorded, and the survival condition and postoperative complications were observed for two weeks.

Results and discussion

The average time of unfolding the shelter, and performing disinfection and preoperative preparation was 33 ± 7 min. The number of colonies in the sterilized shelter body was 86 ± 13 cfu/m³. The average TAE time was 31 ± 7 min. All the hemostatic embolizations of splenic injury were performed successfully in the mobile minimally invasive interventional shelter during the operation. A pseudoaneurysm was found in an animal model using angiography two weeks after the operation. The primary clinical success rate of embolization was 87.5%. The two-week survival rate in all animal models of splenic injury was 100%.

Conclusions

Our findings in the current study demonstrate that the mobile minimally invasive interventional shelter can be adapted to the field perfectly and complete emergency surgical intervention for splenic injury efficiently and safely. Therefore, on-spot emergency interventional TAE for vascular injury of solid organs (e.g. spleen) in mobile minimally invasive interventional shelter is available and effective.

Smooth muscle cells from the anastomosed artery are the major precursors for neointima formation in both artery and vein grafts

Accumulation of smooth muscle cells (SMC) results in neointima formation in injured vessels. Two graft models consisting of vein and artery grafts were created by anastomosing common carotid arteries to donor vessels. To identify the origin of the neointima cells from anastomosed arteries, we use Wnt1-Cre/reporter mice to label and track SMCs in the common carotid artery. The contribution of SMCs in the neighboring arteries to neointima formation was studied. On evaluating the artery grafts after 1 month, >90 % of the labeled neointima cells were found to have originated from the anastomosing host arteries. Most of the neointima cells were also smooth muscle α-actin positive (SMA-α(+)) and expressed the smooth muscle myosin heavy chain (SMMHC), the SMC terminal differentiation marker. In vein grafts, about 60 % SMA-α-positive cells were from anastomosing arteries. Bone marrow cells did not contribute to neointima SMCs in vein grafts, but did co-stain with markers of inflammatory cells. Wnt1 expression was not detected in the neointima cells in the vein or artery grafts, or the injured femoral arteries. Neointima SMCs showed the synthetic phenotype and were positively labeled with BrdU in vitro and in vivo. Treatment with the IGF-1 receptor inhibitor suppressed SMC proliferation and neointima formation in vein grafts. Our results indicate that SMCs from the neighboring artery are predominantly present in the neointima formed in both vein and artery grafts and that Wnt1-Cre mice can be used to explore the role of SMCs originating from neighboring vessels in vascular remodeling.

[Expressions of hypoxia inducible factor 1 alpha and P53 in the epididymis of varicocele rats]

OBJECTIVE

To investigate the mechanism of epididymal hypofunction of rats with varicocele (VC) by observing the changes in the epididymal index, motility of epididymal sperm, expressions of hypoxia-inducible factor 1 alpha (HIF-1 alpha) and the tumor suppressor protein p53, and epididymal epithelial cells.

METHODS

Ninety SD rats were equally randomized to a VC model (A), a sham operation (B), and a normal control group (C). At 49 days after surgery, all the rats were executed after weighing. Then the volume of the left epididymis was obtained, the epididymal sperm motility was detected by computer-assisted sperm analysis (CASA), the expressions of HIF-1 alpha and p53 in the epididymal tissue were determined by Western-blot, and the epididymal epithelial cells were observed by HE staining.

RESULTS

VC models were successfully established in 27 of the rats. One-way ANOVA test showed no statistically significant differences in the epididymis index among groups A ([40.53 +/- 1.76] x 10 (-5)) , B ([43.31 1.58] x 10( -5)) , and C ( [44. 10 +/- 2.62] x 10 -5) (P > 0.05). Sperm motility and the percentage of progressively motile sperm were significantly lower in group A ([71.86 +/- 5.07]% and [42. 26 +/-4.45]%) than in B ([78.51 4.50]% and [49.08 +/-4. 19]% ) and C ( [79.24 +/- 2.70] % and [52. 23+/- 2. 23] % ) (both P <0.05) , while the expressions of HTF-1 a and p53 were remarkably higher in A (1.74 +/- 0. 16 and 1.71 +/- 0. 11) than in B (0.32 +/- 0. 08 and 0.56 +/- 0.13) and C (0.12 +/- 0. 03 and 0.25 +/-0.06) (both P < 0.05). The epididymal epithelial cells in group A were obviously decreased in number and arranged in loose and disorderly patterns as compared with those in B and C.

CONCLUSION

Varicocele can cause hypoxia in the epididymal tissue, which in turn may lead to epididymal hypofunction.

Salidroside protects Caenorhabditis elegans neurons from polyglutamine-mediated toxicity by reducing oxidative stress

Polyglutamine (polyQ) aggregation plays a pivotal role in the pathological process of Huntington's disease and other polyQ disorders. Therefore, strategies aiming at restoring dysfunction and reducing stresses mediated by polyQ toxicity are of therapeutic interest for proteotoxicity diseases. Salidroside, a glycoside from Rhodiola rosea, has been shown to have a variety of bioactivities, including antioxidant activity. Using transgenic Caenorhabditis elegans models, we show here that salidroside is able to reduce neuronal death and behavioral dysfunction mediated by polyQ expressed in ASH neurons, but the neuroprotective effect is not associated with prevention of polyQ aggregation per se. Further experiments reveal that the neuroprotective effect of salidroside in C. elegans models involves its antioxidant capabilities, including decrease of ROS levels and paraquat-induced mortality, increase of antioxidant enzyme activities and reduction of lipid peroxidation. These results demonstrate that salidroside exerts its neuroprotective function against polyQ toxicity via oxidative stress pathways.

Separated response function ratios in exclusive, forward π(±) electroproduction

The study of exclusive π(±) electroproduction on the nucleon, including separation of the various structure functions, is of interest for a number of reasons. The ratio RL=σL(π-)/σL(π+) is sensitive to isoscalar contamination to the dominant isovector pion exchange amplitude, which is the basis for the determination of the charged pion form factor from electroproduction data. A change in the value of RT=σT(π-)/σT(π+) from unity at small -t, to 1/4 at large -t, would suggest a transition from coupling to a (virtual) pion to coupling to individual quarks. Furthermore, the mentioned ratios may show an earlier approach to perturbative QCD than the individual cross sections. We have performed the first complete separation of the four unpolarized electromagnetic structure functions above the dominant resonances in forward, exclusive π(±) electroproduction on the deuteron at central Q(2) values of 0.6, 1.0, 1.6  GeV(2) at W=1.95  GeV, and Q(2)=2.45  GeV(2) at W=2.22  GeV. Here, we present the L and T cross sections, with emphasis on RL and RT, and compare them with theoretical calculations. Results for the separated ratio RL indicate dominance of the pion-pole diagram at low -t, while results for RT are consistent with a transition between pion knockout and quark knockout mechanisms.

[Correlation between the changes of surface electromyographic signals of elbow flexor and extensor and motor function in stroke patients]

OBJECTIVE

To explore the correlation between the changes of surface electromyography (sEMG) signals of biceps and triceps and torques for elbow flexion and extension during maximum isometric voluntary contraction (MIVC) and motor function in convalescent stroke patients so as to provide rationale for rehabilitation.

METHODS

Fifteen stroke patients and 15 age and gender-matched normal controls were recruited. The sEMG signals of biceps and triceps were recorded during MIVC of elbow flexion and extension. Co-contraction ratio (CR) and torques of both groups were compared and analyzed. The motor function of upper extremity was assessed by Fugl-Meyer assessment upper extremity (FMA-UE).

RESULTS

There were significant differences in EMG ((132 ± 65) mV×s,(124 ± 50) mV×s) and torques ((13 ± 8) N×m, (10 ± 6) N×m) at affected side with those at unaffected side and controls during MIVC of elbow flexion and extension (P < 0.05).Significant differences existed in CR ((30 ± 13)%) at affected side with unaffected side ((18 ± 8)%) and controls ((16 ± 6)%) during MIVC of elbow extension (P < 0.05). The score of FMA-UE at affected side was significantly positively correlated with iEMG on biceps during MIVC of elbow flexion (r = 0.579, P = 0.024) and on triceps during MIVC of elbow extension (r = 0.618, P = 0.014). The score of FMA-UE at affected side was significantly positively correlated with torques during MIVC of elbow flexion and extension (rflexion = 0.518, P = 0.048; rextension = 0.679, P = 0.005). The score of FMA-UE at affected side was significantly negatively correlated with CR during MIVC of elbow flexion and extension (rflexion = -0.579, P = 0.024; rextension = -0.693, P = 0.004).

CONCLUSION

The strength of flexor and extensor of bilateral elbow decreases in convalescent stroke patients. The spasticity of elbow flexor still exists. Besides increasing the strength of bilateral upper extremities, particularly affected side, rehabilitation should also focus upon reducing spasticity of flexor to enhance elbow joint stability and improve motor function.

Overview of beverages with anti-aging functions in Chinese market

Anti-aging Chinese medicines have been used in traditional beverages to promote health and prevent diseases. Interestingly, these functional beverages may be used differently between men and women, reflecting the "yin-yang" philosophy of Chinese medicine. Modern studies have revealed that some dietary natural products can slow aging in model organisms, and functional beverages containing such products have recently emerged in Chinese market, challenging the dominance of traditional functional beverages. Here we summarize both traditional anti-aging herbs and modern natural dietary compounds currently used in functional beverages in China, and also briefly outline the underlying mechanisms of the beverages in slowing aging process.