Enhancement of recombinant adeno-associated virus mediated transgene expression by targeted echo-contrast agent

Ultrasound‑targeted microbubble destruction‑mediated Galectin‑7‑siRNA promotes the homing of bone marrow mesenchymal stem cells to alleviate acute myocardial infarction in rats

Bone marrow mesenchymal stem cells (BMSCs) are accepted as a form of cellular therapy to improve cardiac function following acute myocardial infarction (AMI). The present study was performed to investigate the synergistic effect of ultrasound-targeted microbubble destruction (UTMD)-mediated Galectin-7-small interfering (si)RNA with the homing of BMSCs for AMI. The rat model of AMI was established, followed by identification of BMSCs. Rats with AMI received BMSC transplantation, BMSC transplantation + UTMD + siRNA negative control, or BMSC transplantation + UTMD + Galectin-7-siRNA. The cardiac function, hemodynamics indexes, degree of myocardial fiber injury and expression of apoptosis-related proteins in myocardial tissues of rats were detected. The homing of BMSCs was observed, and the indexes of myocardial microenvironment and the TGF-β/Smads pathway-related proteins in myocardial tissues were determined. AMI rats treated with UTMD-mediated Galectin-7-siRNA exhibited improved cardiac function and hemodynamics-related indices, decreased myocardial fiber injury and apoptotic cells, as well as enhanced homing ability of BMSCs, improved myocardial microenvironment, and suppressed TGF-β1/Smads pathway activation. In conclusion, the present study demonstrated that UTMD-mediated Galectin-7-siRNA treatment could enhance the homing ability of BMSCs, thus alleviating AMI in rats.

In Vivo Ultrasound Molecular Imaging of SDF-1 Expression in a Swine Model of Acute Myocardial Infarction

Background: Stem cell therapy of acute myocardial infarction (AMI) is proving to be a promising approach to repair the injured myocardia. The time window for stem cell transplantation is crucial yet difficult to determine since it produces different therapeutic effects at different times after myocardial infarction. Stromal cell-derived factor-1 (SDF- 1) plays a pivotal role in the mobilization, homing, proliferation, and differentiation of transplanted stem cells. Here, by using ultrasound molecular imaging via targeted microbubbles, we determined the dynamic expression of SDF-1 in a swine model of AMI in vivo. Methods: Twenty-four miniswine were randomly selected for the control group and the AMI model group, which underwent ligation of the left anterior descending coronary artery (LAD). The AMI animals were randomly divided into six experimental groups according to the duration of the myocardial infarction. All animals were subjected to ultrasound molecular imaging through injections with targeted microbubbles (T + T group) or nontargeted control microbubbles (T + C group). The values of the myocardial perfusion parameters (A, β, and A × β) were determined using Q-Lab (Philips ultrasound, version 9.0), and the expression level of SDF-1 was analyzed by real-time polymerase chain reaction (RT-PCR). Results: Our results showed that the expression of SDF-1 gradually increased and peaked at 1 week after AMI. The trend is well reflected by ultrasound molecular imaging in the myocardial perfusion parameters. The A, β, and A × β values correlated with SDF-1 in the T + T group (r = 0.887, 0.892, and 0.942; P < 0.05). Regression equations were established for the relationships of the A, β, and A × β values (X) with SDF-1 (Y): Y = 0.699X - 0.6048, Y = 0.4698X + 0.3282, and Y = 0.0945X + 0.6685, respectively (R 2 = 0.772, 0.7957, and 0.8871; P < 0.05). Conclusions: Our finding demonstrated that ultrasound molecular imaging could be used to evaluate the expression dynamics of SDF-1 after AMI.

Homing of endogenous bone marrow mesenchymal stem cells to rat infarcted myocardium via ultrasound-mediated recombinant SDF-1α adenovirus in microbubbles

Stem cells can promote myocardial regeneration and accelerate the formation of new blood vessels. As such, transplanted stem cells represent a promising treatment modality for acute myocardial infarction (AMI). Stem cells spontaneously home to the infarcted myocardium using chemotaxis, in which the stromal cell-derived factor (SDF-1α) has been shown to be one of the most important chemokines. However, spontaneously secreted SDF-1α is short-lived, and therefore does not meet the needs of tissue repair. In this study, adenoviruses carrying SDF-1α genes were loaded on microbubble carriers and the adenoviruses were released into AMI rats by ultrasound targeted microbubble destruction. The possibility of in vivo self-transplantation of bone marrow mesenchymal stem cells (BMSCs) induced by overexpression of SDF-1α in the infarcted myocardium was explored by detecting the number of BMSCs homing from the peripheral blood to the myocardial infarcts. The concentration of SDF-1α in peripheral blood was significantly higher after transfection, and the number of BMSCs was significantly higher in the peripheral blood and infarcted area. Further analyses indicated that the number of homing BMSCs increased with increased SDF-1α expression. In conclusion, our results suggest that ultrasound mediated transduction of exogenous SDF-1α genes into myocardial infarcted AMI rats can effectively promote the homing of endogenous BMSCs into the heart. Moreover, the number of homing stem cells was controlled by the level of SDF-1α expression.

Treatment for insomnia in combat-exposed OEF/OIF/OND military veterans: preliminary randomized controlled trial

Chronic insomnia is highly prevalent among military personnel returning from Iraq and Afghanistan. We evaluated the effects of a military version of a brief behavioral treatment of insomnia (BBTI-MV) compared to an information only control (IC) condition in combat-exposed Veterans of Operations Enduring/Iraqi Freedom or Operation New Dawn (OEF/OIF/OND) on insomnia, sleep quality, and daytime symptoms of anxiety and depression. Forty OEF/OIF/OND Veterans (Mean age = 38.4 years old, s.d. = 11.69; 85% men; 77.5% white) were randomized to one of two conditions. BBTI-MV consisted of two in-person sessions and two telephone contacts delivered over four weeks, and included personalized recommendations to reduce insomnia. The IC condition also consisted of 2 in-person sessions two telephone contacts delivered over four weeks, and Veterans were encouraged to read written information about sleep-promoting behaviors. The Insomnia Severity Index, Pittsburgh Sleep Quality Index, PTSD Checklist, and Beck Depression and Anxiety Inventories were completed at baseline, post-treatment, and at the six-month follow-up. Both interventions were associated with clinically significant improvements in insomnia, although the magnitude of improvements in sleep and rates of treatment response and remission were greater for BBTI-MV compared to IC from pre- to post-treatment. Both BBTI-MV and the provision of information were associated with clinically significant improvements in insomnia among Veterans. Despite the preliminary nature of the findings and limitations inherent to small controlled trials, the findings suggest that both approaches may provide viable options in a stepped-care approach to the treatment of insomnia in retuning combat-exposed Veterans. Larger, confirmatory effectiveness trials are required.

CLINICALTRIALSGOV IDENTIFIER

NCT00840255.