Yun Luan

Implantation of Mesenchymal Stem Cells Improves Right Ventricular Impairments Caused by Experimental Pulmonary Hypertension

Introduction:Pulmonary hypertension (PH) is a rapidly progressive and fatal disease. In recent years, despite drug treatment made significant progress, the prognosis of patients with advanced PH remains extremely poor. The authors implanted bone marrow-derived mesenchymal stem cells (BMSCs) intravenously into the PH model rats and observed the effect of MSCs on right ventricular (RV) impairments. Methods:BMSCs were isolated, cultured from bone marrow of rats and stained with the cross-linkable membrane dye in vitro. One week after, a PH model was induced by subcutaneous injection of monocrotaline, the animals were randomly divided into 4 groups (n = 20 in each group): I, control; II, MSCs implantation; III, PH and IV, PH + MSCs implantation. Two weeks after MSCs implantation, the authors observed the MSC survival and transformation by immunofluorescence microscopy. On the other hand, RV hypertrophy and the elevation of systolic pressure were detected by echocardiography. Result:Three weeks after monocrotaline injection, RV systolic pressure, mean right ventricular pressure and mean pulmonary arterial pressure were significantly elevated in group III than in group I and II (P < 0.05) but significantly lower in group IV than in group III (P < 0.05). These results showed that implantation of MSCs could improve RV impairments caused by experimental PH. Histochemical results confirmed that transplanted MSCs were still alive after 2 weeks and part of the cells could differentiate into pulmonary vascular endothelial cells. Conclusion:Intravenous implantation of MSCs could significantly reduce or even reverse the progression of MCT-induced PH, improve cardiac function and hemodynamics.

Mesenchymal stem cell prevention of vascular remodeling in high flow-induced pulmonary hypertension through a paracrine mechanism.

UNLABELLED Pulmonary arterial hypertension (PAH) is characterized by functional and structural changes in the pulmonary vasculature, and despite the drug treatment that made significant progress, the prognosis of patients with advanced PH remains extremely poor. In the present study, we investigated the early effect of bone marrow mesenchymal stem cells (BMSCs) on experimental high blood flow-induced PAH model rats and discussed the mechanism. BMSCs were isolated, cultured from bone marrow of Sprague-Dawley (SD) rat. The animal model of PAH was created by surgical methods to produce a left-to-right shunt. Following the successful establishment of the PAH model, rats were randomly assigned to three groups (n=20 in each group): sham group (control), PAH group, and BMSC group (received a sublingual vein injection of 1-5 × 10(6) BMSCs). Two weeks after the administration, BMSCs significantly reduced the vascular remodeling, improved the hemodynamic data, and deceased the right ventricle weight ratio to left ventricular plus septal weight (RV/LV+S) (P<0.05). Real-time reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry analysis results indicated that the inflammation factors such as interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α) were reduced (P<0.05); the expression of matrix metallo proteinase-9 (MMP-9) was lower (P<0.05); vascular endothelial growth factor (VEGF) was higher in BMSC group than those in PAH group (P<0.05). CONCLUSION Sublingual vein injection of BMSCs for 2 weeks, significantly improved the lung and heart injury caused by left-to-right shunt-induced PAH; decreased pulmonary vascular remodeling and inflammation; and enhanced angiogenesis.

PAR1‐stimulated platelet releasate promotes angiogenic activities of endothelial progenitor cells more potently than PAR4‐stimulated platelet releasate

Endothelial progenitor cells (EPCs) are important for endothelial regeneration and angiogenesis. Thrombin protease‐activated receptor 1 (PAR1) PAR1 and PAR4 stimulation induces selective release of platelet proangiogenic and antiangiogenic regulators.

Porcine kidneys as a source of ECM scaffold for kidney regeneration

OBJECTIVE To produce and examine decellularized kidney scaffolds from porcine as a platform for kidney regeneration research. METHODS Porcine kidneys were decellularized with sodium dodecyl sulfate solution and Triton X-100 after the blood was rinsed. Then the renal ECM scaffolds were examined for vascular imaging, histology to investigate the vascular patency, degree of decellularization. RESULTS Renal ECM scaffolds of porcine kidneys were successfully produced. Decellularized renal scaffolds retained intact microarchitecture including the renal vasculature and essential extracellular matrix components. CONCLUSION We have developed an excellent decellularization method that can be used in large organs. These scaffolds maintain their basic components, and show intact vasculature system. This represents a step toward development of a transplantable organ using tissue engineering techniques.

Effect of bone marrow mesenchymal stem cells on experimental pulmonary arterial hypertension

The aim of the present study was to investigate the effect of bone marrow mesenchymal stem cell (BMSC) transp1antation on lung and heart damage in a rat model of monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH). The animals were randomly divided into 3 groups: control, PAH and BMSC implantation groups. Structural changes in the pulmonary vascular wall, such as the pulmonary artery lumen area (VA) and vascular area (TAA) were measured by hematoxylin and eosin (H&E) staining, and the hemodynamics were detected by echocardiography. Two weeks post-operation, our results demonstrated that sublingual vein injection of BMSCs significantly attenuated the pulmonary vascular structural and hemodynamic changes caused by pulmonary arterial hypertension. The mechanism may be executed via paracrine effects.

The effective bioengineering method of implantation decellularized renal extracellular matrix scaffolds

End stage renal disease (ESRD) is a progressive loss of kidney function with a high rate of morbidity and mortality. Transplantable organs are hard to come by and hold a high risk of recipient immune rejection. We intended to establish a more effective and faster method to decellularize and recellularize the kidney scaffold for transplant and regeneration. We successfully produced renal scaffolds by decellularizing rat kidneys with 0.5% sodium dodecyl sulfate (SDS), while still preserving the extracellular matrix (ECM) 3D architecture, an intact vascular tree and biochemical components. We recellularized the kidney scaffolds with mouse embryonic stem (ES) cells that then populated and proliferated within the glomerular, vascular, and tubular structures. After in vivo implantation, these recellularized scaffolds were easily reperfused, tolerated blood pressure and produced urine with no blood leakage. Our methods can successfully decellularize and recellularize rat kidneys to produce functional renal ECM scaffolds. These scaffolds maintain their basic components, retain intact vasculature and show promise for kidney regeneration.

Differential shortening rate of telomere length in the development of human fetus.

Telomeres play an important role in the maintenance of genomic stability/integrity and are synthesized by the RNA-dependent polymerase telomerase. Progressive telomere shortening contributes to both in vitro and in vivo aging, and telomere length dynamics and telomerase expression profile in human tissues during extrauterine life have been well characterized. However, little is known about these changes in the early stage of gestation. In the present study, we determined telomere length and the expression of telomerase core units (telomerase reverse transcriptase, hTERT, and telomerase RNA component, hTERC) in human fetus tissues from 6 to 11 weeks of gestational age. A sharp decline in telomere length occurred between 6 and 7 weeks of gestational age, and a relatively stable or slightly shortened telomere length was thereafter maintained until birth. The inverse correlation between TERT or TERC expression and gestational age was steadily observed in these fetus tissues. Taken together, there is a rapid reduction followed by a slow erosion of telomere length in human fetus from gestational age 6-11 weeks, while hTERT and hTERC expression decreases steadily during this period. The present findings not only contribute to better understandings of telomere/telomerase biology in human embryonic development, but also are implicated in telomere/telomerase-related diseases or problems.

Therapeutic effects of baicalin on monocrotaline-induced pulmonary arterial hypertension by inhibiting inflammatory response

BACKGROUND Baicalin has been shown to possess various pharmacological actions, a recent study revealed that baicalin can attenuate pulmonary hypertension and pulmonary vascular remodeling through the inhibition of pulmonary artery smooth muscle cell proliferation, however, the potential mechanism remains unexplored. In this study, we investigated the therapeutic effect of baicalin on a rat model of monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH) and attempted to further clarify the possible mechanisms underlying the anti-inflammatory. METHODS AND RESULTS: Our research showed that compared with MCT-induced PAH model rats, rats administered intragrastically with 100mg/kg baicalin showed the following after two weeks: the right ventricular systolic pressure (RVSP) and the right ventricle/left ventricle plus septum (RV/LV+S) ratio were lower (P<0.05); the intima thickening and luminal stenosis were improved (P<0.05); the mRNA levels of tumor necrosis factor alpha (TNF-α), interleukin-11β (IL-1β), IL-6, and endothelin-1 (ET-1) were obviously reduced by quantitative reverse transcription-polymerase chain reaction (qRT-PCR); the protein expression of transforming growth factor-β1 (TGF-β1), intercellular cell adhesion molecule-1 (ICAM-1) and nuclear factor-κB (NF-κB) were significantly decreased (P<0.05); and the expression of inhibitor of NF-κB (I-κB) was increased (P<0.05) through immunohistochemical and western blot. CONCLUSION We studied the protective effects of baicalin against the lung and heart damage in experimental PAH rats; the therapeutic effects maybe through inhibiting vascular endothelial inflammatory response.

Baicalin protects the myocardium from reperfusion‑induced damage in isolated rat hearts via the antioxidant and paracrine effect

The aim of the present study was to investigate the protective effect of baicalin (BA) against ischemia-reperfusion (I/R) injury in isolated rat hearts. Sprague-Dawley rat hearts were rapidly removed, mounted on a Langendorff apparatus and subjected to 30 min ischemia followed by 30 min reperfusion with Krebs-Henseleit (K-H) solution at 37°C to establish the isolated I/R injury model. All animals (n=50) were randomly divided into five groups (n=10 in each): I, normal control; II, I/R; III, I/R plus 20 mg/kg BA; IV, I/R plus 40 mg/kg BA; and V, I/R plus 80 mg/kg BA. The degree of heart injury caused by the I/R was assessed by evaluating left ventricular function and by detecting the levels of lactate dehydrogenase (LDH) and creatine kinase (CK) in the coronary effluent and the myocardial superoxide dismutase (SOD) and malondialdehyde (MDA) levels in the isolated rat hearts. Myocardial infarct size and vascular density were assessed using histology and immunohistochemistry. The apoptotic cardiomyocytes were determined using flow cytometry (FCM). Compared with group II, the BA groups demonstrated improved left ventricular function, reduced CK and LDH release in the coronary effluent and increased SOD and MDA activity (P<0.05). Furthermore, histology and immunohistochemistry results showed that the infarct size was reduced and vessel density was augmented in the BA groups (P<0.01) compared with group II. The FCM results indicated that apoptosis was significantly lower in the BA groups than in group II (P<0.05) and that the protective effect was dose-dependent. In conclusion, these results demonstrated that BA exerts a dose-dependent protective effect on I/R injury in isolated rat hearts, the mechanisms of which may be associated with antioxidant and anti-apoptosis properties. To the best of our knowledge, this study is the first evaluation of the efficacy of BA in isolated rat hearts using histology and immunohistochemistry, providing a foundation for the use of BA in the treatment of acute myocardial infarction.

Platelet releasate promotes breast cancer growth and angiogenesis via VEGF–integrin cooperative signalling

Background:Selective platelet release of pro- or anti-angiogenic factors distinctly regulated angiogenesis. We hypothesised that selective release of platelet angiogenic factors could differently regulate tumour growth.Methods:Breast cancer cell proliferation, cancer cell-induced endothelial tube formation in vitro, and tumour growth in vivo were studied in the presence of protease-activated receptor 1-stimulated platelet releasate (PAR1-PR; rich in pro-angiogenic factors) or PAR4-PR (rich in anti-angiogenic factors).Results:The PAR1-PR and PAR4-PR supplementation (10%) similarly enhanced cell proliferation of MCF-7 and MDA-MB-231 breast cancer cells. The cancer cells triggered capillary-like tube formation of endothelial cells that was further enhanced by pro-angiogenic factor-rich PAR1-PR. The VEGF, but not SDF-1α, receptor blockade abolished PAR1-PR/PAR4-PR-enhanced cancer cell proliferation. Integrin blockade by RGDS had identical effects as VEGF inhibition. The Src and ERK inhibition diminished, whereas PI3K and PKC blockade abolished platelet releasate-enhanced cancer cell proliferation. Using a model of subcutaneous implantation of MDA-MB-231 cells in nude mice, PAR1-PR enhanced tumour growth more markedly than PAR4-PR, and seemed to achieve the exaggeration by promoting more profound tumour angiogenesis.Conclusions:Platelet releasate increases breast cancer cell proliferation through VEGF–integrin cooperative signalling. Pro-angiogenic factor-rich platelet releasate enhances cancer cell-induced angiogenesis more markedly, and thus exaggerates tumour growth in vivo.