Mild hypothermia effects on matrix metalloproteinase-9 expression in the perihematomal region of rats following experimental intracerebral hemorrhage

BACKGROUND： Matrix metalloproteinase-9 （MMP-9） expression increases with intracerebral hemorrhage, and participates in the pathophysiological processes of secondary brain injury after intracerebral hemorrhage. OBJECTIVE： To investigate the effects of mild hypothermia on MMP-9 expression and brain edema in the perihematomal region of experimental intracerebral hemorrhage rats. DESIGN, TIME AND SETTING： The randomized, controlled experiment was performed at the Central Laboratory of Shandong Provincial Hospital between May and September 2007. MATERIALS： Seventy-two, Wistar, male rats, 12-weeks old, were used for this study. Rabbit anti-MMP-9 primary antibody was purchased from Boster, China. METHODS： Wistar rats were equally and randomly divided into normothermia and mild hypothermia groups. The two groups each comprised control, 6-hour intracerebral hemorrhage, 24-hour intracerebral hemorrhage, 48-hour intracerebral hemorrhage, 72-hour intracerebral hemorrhage, and l-week intracerebral hemorrhage subgroups, with six rats in each subgroup. Rat models of intracerebral hemorrhage were established by injecting 100 μL of autologous blood into the rat caudate nucleus. Rats in the mild hypothermia group received four hours of local mild hypothermia immediately following the injection. lntracerebral temperature was maintained at （33 ± 0.5） ℃. Subsequently, intracerebral temperature was spontaneously recovered at 25 ℃. Rats in the control subgroup were not injected with autologous blood and received only with intracerebral hemorrhage. MAIN OUTCOME MEASURES： Brain water content and MMP-9 expression surrounding the hematoma region. RESULTS： MMP-9 expression increased at 6 hours, and brain edema reached a peak at 48 hours after intracerebral hemorrhage. MMP-9 expression was significantly decreased in the mild hypothermia group compared with the normothermia group at each time point （P 〈 0.05）. CONCLUSION： Mild hypothermia can significantly inhibit MMP-9 overexpression and relieve brain edema following intracerebral hemorrhage.

Morphology of the ascending aorta: a study on 114 Chinese patients

Purpose: This study aimed to investigate the morphological characteristics of ascending aortic dissection in detail. Materials and Methods: The ascending aorta was morphologically assessed in a consecutive series of patients between January 2009 and October 2014. A new assessment and evaluation method was used to describe 114 patients with ascending aortic dissection. Results: A large difference was found in the degree of curvature between the ascending aorta with and without dissection. The shape of the former was straighter and steeper(control group R, 47.46 ± 6.40 mm; experimental group R, 59.70 ± 10.27 mm, P < 0.001). In the case of aortic dissection involving the valves, the proximal edge of the first entry was obviously close to the aortic sinus. The orientation of the entries was mainly around the 10 o'clock and 1–2 o'clock positions, and most of their shapes were fusiform(111; 70.02%). The distance of the distal extending dissection was associated with cases involving the branch arteries(involving three branches 441.40 ± 101.13 mm vs 159.85 ± 131.86 mm in others, P < 0.001). Conclusion: The morphological features of the ascending aorta after dissection and the correlations among dissections, entries, and related factors were found.

Reprogramming of mouse neural stem cells to induced pluripotent stem cells using Oct4 combined with microRNA

microRNA is important for maintaining characteristics of embryonic stem cells, and microRNA302a （MiR-302a） has been shown to exert important effects on cell reprogramming. Therefore, the present study used miR294 and miR302a, in combination with Oct4, to induce mouse neural stem cells （NSCs） into induced pluripotent stem （iPS） cells. Following identification of iPS cells, the effects of microRNA on cell reprogramming were analyzed. Results suggested that reprogramming efficiency with Oct4 ＋ miR-294 ＋ miR-302a was 7-fold greater than Oct4 alone （0.1% vs. 0.014%）. The iPS cells were undifferentiated and positive for alkaline phosphatase, SSEA-1, and Oct4. These findings demonstrated that microRNAs play an important role in cell reprogramming and provide a safe and efficient induction system for cellular reprogramming.

Lentivector-mediated RNAi efficiently downregulatesexpression of murine cdk4 gene in vitro

In order to explore the role of cyclin-dependent kinase 4(cdk4)in neurodegenerative diseases,lentiviral-delivered RNA interference(RNAi)was used to silence the expression of the murine cdk4 gene in vitro.Three cdk4-shRNAs of mouse and a negative sequence were designed.After synthesis and annealing,double strand oligonucleo-tides were cloned into a linearized pSIH1-H1-copGFP shRNA vector.It was confirmed by polymerase chain reaction(PCR)and sequencing that three pairs of cdk4-shRNAs and a negative shRNA were correctly inserted into the pSIH1-H1-copGFP vector.The above recombi-nants were transfected by lipofectamine into BV-2 cells.The gene silencing efficacy rates of the 3 targets were compared by Western blotting.The cdk4-siRNA2 was the most effective in silencing cdk4.The optimized pSIH1-cdk4-siRNA2 and pSIH-negative-siRNA were co-transfected into 293T cells with the lentiviral packaging plasmids respectively.The culture supernatant was har-vested and condensed at the 24th and 48th h after transfection.Interference efficiency of the lentivirus expressing cdk4-siRNA was determined by reverse transcriptase-PCR(RT-PCR)and Western blotting in BV-2 cells.Lentivector-mediated RNAi could efficiently down-regulate the expression of the murine cdk4 gene in vitro,which provides a potential tool for studying and treating cdk4-related diseases.

Stem cell therapy for amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis(ALS)is a fatal neurodegenerative disorder characterized by the loss of motor neurons.Currently,no effective therapy is available to treat ALS,except for Riluzole,which has only limited clinical benefits.Stem-cell-based therapy has been intensively and extensively studied as a potential novel treatment strategy for ALS and has been shown to be effective,at least to some extent.In this article,we will review the current state of research on the use of stem cell therapy in the treatment of ALS and discuss the most promising stem cells for the treatment of ALS.