Uncoupling protein 2(UCP2)is a proton transporter which presents in the mitochondrial inner membrane. Recent studies have found that UCP2 plays important roles in protecting mitochondria functions,re-ducing mitochondrial ROS generation by inducing proton leak across the inner mitochondrial membrane and pro-moting mild uncoupling which leading to a decrease in the mitochondrial inner membrane′s potential. Because of its antioxidant function,UCP2 has been studied in several domains. This review provides novel insights into the molecular mechanisms,by which the activity of UCP2 is regulated and describe novel findings concerning basical experiments of UCP2.

Hypermetabolism syndrome,especially in skeletal muscles,is exceedingly common in septic patients.Many studies suggest that the activity of ubiquitin-proteasome pathway is a vital procedure for hypermetabolism of skeletal muscles of septic patients and its activation can be influenced by a variety of factors,such as proinflammatory cytokine and glucocorticoid,etc.Evidences indicate that insulin has played an important role in opsonizing the activation of ubiquitin-proteasome pathway.This paper reviews the regulation effect of insulin to the hypermetabolism of the skeletal muscles of septic patients through ubiquitin-proteasome pathway.

The aim of this research is to investigate the preparation method of valve membrane in transcatheter bio- prosthetic valve, and to study the effect of chemical modification and cutting technology to tensile property and suture force property of valve membrane. We carried out a series of processes to perform the tests, such as firstly to test the crosslinking degree of valve membrane using ninhydrin method, then to test the tensile property and suture force property by using Instron's biomechanicAl testing equipment, and then to observe the collagen fiber orientation in valve membrane using Instron's biomechanical testing equipment and using field emission scanning electron microscopy. The study indicated that after the chemical modification, the crosslinking degree, tensile strength and suture force strength increasing rate of valve membrane were 93.78% ± 3. 2%, (8.24 ± 0.79) MPa, 102%, respectively. The valve membrane had a better biomechanical property and would be expected to become valve membrane in transcatheter bioprosthesis valve.
Bioprosthesis ; Collagen ; chemistry ; Heart Valve Prosthesis ; Microscopy, Electron, Scanning ; Tensile Strength

BACKGROUND:Conditioned medium from mesenchymal stem cels (MSC-CM) that contains abundant MSCs paracrine substances may represent a promising alternative to MSCs transplantation. However, normal MSC-CM with insufficient paracrine ability is not effective for tissue damage repair. OBJECTIVE:To investigate the effects of MSC-CM with (MSC-CMHyp) and without hypoxic activation (MSC-CMNor) on the proliferation and apoptosis of radiation-induced injured intestinal epithelial cels (IEC-6) and to further discuss the paracrine mechanisms. METHODS: IEC-6 cels were exposed to 10 Gy irradiation and cultured in MSC-CMHyp, MSC-CMNor, and DMEM-F12 medium, respectively. RESULTS AND CONCLUSION: Findings from trypan blue staining, flow cytometry and western blot assay showed that, compared with the DMEM-F12 medium group, treatment with MSC-CMHyp significantly enhanced IEC-6 viability proliferation after radiation-induced injury, as wel as significantly decreased cel apoptosis and expression of Caspases-3/8 (P < 0.05). However, there was no significant difference between the MSC-CMNor group and DMEM-F12 medium group (P > 0.05). On the other hand, the increased levels of vascular endothelial growth factor, basic fibroblast growth factor, insulin-like growth factor-1, and interleukin-10 were detected in the MSC-CMHyp group compared to the MSC-CMNor group (P < 0.05). These results suggest that the MSC-CMHyp improves the viability and proliferative capacity of IEC-6 cels after radiation-induced injuryvia up-regulating secretion of cytokines and down-regulating apoptotic signaling.

Objective To investigate the effects of epinephrine in sepsis-associated lung injury in rats. Methods Thirty SD rats were randomly divided into three groups(n =10 per group):control group received intravenous 0. 9% saline 2. 4 ml/( kg·h ); LPS group received intravenous LPS ( 6 mg/kg ); epi-nephrine treatment group received an infusion of epinephrine 0. 6μg/( kg·min) after LPS intravenous injec-tion . Blood samples were taken at 2 h and 6 h after LPS injection and the levels of serum tumor necrosis factor ( TNF)-α,interleukin( IL)-6 and IL-10 were detected. The rats were sacrificed at 6 h. The lung tissues and bronchoalveolar lavage fluid( BALF) were collected. Pathological changes of the lung tissues were observed under light microscope. Water content of lung,expression of TNF-α,IL-6 and IL-10 in BALF and in serum were detected. Results (1) The water content of lung in LPS group significantly increased compared with that in control group(85. 24% ± 5. 87% vs. 70. 19% ± 5. 87%) and epinephrine group(78. 00% ± 6. 41%) (P<0. 05). (2)Pathological examination showed that LPS could cause pulmonary capillary hyperemia,ede-ma,inflammatory cells infiltration. Atelectasis and alveolar edema were found in small number of lung tissue. Compared with LPS group, epinephrine ameliorated the lung pathological injury. ( 3 ) Compared with LPS group,serum levels of TNF-α and IL-6 significantly decreased ( P <0. 05 ) , whereas IL-10 increased ( P <0. 05) in epinephrine group. (4)Compared with LPS group,BALF levels of TNF-α[(78 ± 9)ng/L vs. (102 ±16)ng/L]andIL-6[(268±42)ng/Lvs.(347±50)ng/L]significantlydepressed(P<0.05),whereas BALFlevelsofIL-10[(210±23)ng/Lvs.(146±34) ng/L]elevated(P <0.05) inepinephrinegroup. Conclusion Epinephrine could reduce the acute lung injury caused by LPS. Its protective effect may be re-lated to decreasing the levels of TNF-α and IL-6,elevating IL-10 level.

ObjectiveTo investigate the effects of autophagy on exocrine function of pancreas in rats with acute sepsis, and to determine whether the mitochondrial coenzyme Q (Mito Q) can prevent exocrine dysfunction of pancreas mediated by autophagy.Methods ExperimentⅠ: 30 Sprague-Dawley (SD) rats were randomly divided into three groups, with 10 rats in each group. All the rats were given lipopolysaccharide (LPS, 10 mg/kg) intraperitoneally, and Wortmannin (2 mg/kg), the specific inhibitor of autophagy (LPS+ Wortmannin group), Mito Q (6.5μmol/kg, LPS+Mito Q group), or the same volume of normal saline (LPS group) was respectively injected via the tail vein 1 hour later. Survival rate was assessed within 12 hours after LPS injection. ExperimentⅡ: another 100 male SD rats were randomly divided into ten groups with 10 rats in each group: namely control 4, 6 and 12 hours groups, LPS 4, 6 and 12 hours groups, and LPS+ Wortmannin 4 hours group, Wortmannin 4 hours group, LPS+ Mito Q 6 hours group, and Mito Q 6 hours group. The protocols of model reproduction and drug administration were the same as in the experimentⅠ. Blood samples were collected at each time point, and the amylase content was determined with the velocity method. The levels of reactive oxygen species (ROS) in the pancreases were measured with enzyme-linked immunosorbent assay (ELISA). The expression of the autophagy-related protein LC3 was determined with Western Blot. The pathological changes in the pancreas were observed with microscopy.Results① The survival time in the LPS+ Wortmannin group was significantly shorter than that in the LPS group (hours: 7.50±0.64 vs. 11.90±0.13,χ2= 19.847,P= 0.001). There was no significant difference in the survival time between LPS+ Mito Q and LPS groups (hours: 11.60±0.24 vs. 11.90±0.13,χ2= 1.055,P= 0.137).② The serum amylase in the LPS 6 hours, LPS+ Wortmannin 4 hours, and LPS+ Mito Q 6 hours groups were significantly higher than those in the control group at the same time points (U/L:2 881.00±550.12 vs. 2 099.20±249.57, 3 672.00±779.24 vs. 2 081.36±245.18, 2 975.20±687.03 vs. 2 099.20± 249.57, allP< 0.05), and were significantly lowered in LPS 12 hours group (U/L: 794.00±218.71 vs. 2 086.80±261.75, P< 0.01). The pancreatic ROS in the LPS 6 hours and 12 hours groups, LPS+ Wortmannin 4 hours group, and LPS+Mito Q 6 hours group were significantly higher than those of the control group at the same time points (kU/L: 3.18±1.06 vs. 1.78±0.37, 3.63±1.08 vs. 1.85±0.41, 3.14±0.98 vs. 1.65±0.34, 3.17±1.03 vs. 1.78±0.37, allP< 0.05). The serum amylase and pancreatic ROS in LPS+ Wortmannin 4 hours group were significantly higher than those of the LPS group at the same time points (U/L: 3 672.00±779.24 vs. 2 432.20±442.85, kU/L: 3.14±0.98 vs. 1.87±0.42, both P< 0.05), but there were no differences in above two parameters between LPS+ Mito Q 6 hours group and LPS group (U/L: 2 975.20±687.03 vs. 2 881.00±550.12, kU/L: 3.17±1.03 vs. 3.18±1.06, bothP> 0.05). Light microscopy showed that obvious pathological changes were found in the pancreas in the LPS 6 hours and 12 hours groups, LPS+Wortmannin 4 hours group, and LPS+ Mito Q 6 hours group. Electron microscopy showed that the number of autophagic vacuoles increased 6 hours after LPS administration. There was no difference at any time point in the number of autophagic vacuoles between LPS+ Mito Q 6 hours group and LPS 6 hours group, and the autophagic vacuoles were not found after Wortmannin intervention. It was demonstrated by Western Blot that the levels of LC3 protein in the LPS 6 hours and 12 hours groups, and LPS+ Mito Q 6 hours group were significantly higher than those of the control group at the same time points (A value: 0.34±0.02 vs. 0.17±0.02, 0.37±0.03 vs. 0.18±0.04, 0.36±0.02 vs. 0.17±0.02, allP< 0.05), but there were no differences between LPS 12 hours group or LPS+ Mito Q 6 hours group and LPS 6 hours group (bothP> 0.05).Conclusions Autophagy prevents exocrine dysfunction of pancreas in septic rats, and the autophagic capacity or autophagosome-formation rate may determine the development of exocrine pancreatic dysfunction. The mitochondria-targeted antioxidant Mito Q does not prevent exocrine dysfunction of pancreas.

Objective To investigate the effects of autophagy on cardiac function and to determine whether the mitochondrial coenzyme Q (MitoQ) prevents cardiac dysfunction,mediated by autophagy,in rats with acute sepsis.Methods Forty-five Sprague Dawley (SD) rats were randomly divided into 9 groups (n =5,each group):control group,4 h lipopolysaccharide(LPS) group,6 h LPS group,12 h LPS group,4 h LPS + Wortmannin group,4 h LPS + MitoQ group,6 h LPS + MitoQ group,MitoQ group and Wortmannin group.Rats in LPS + Wortmannin group and LPS + MitoQ group were intraperitoneally given LPS(10 mg/kg) and followed by an injection of Wortmannin(2 mg/kg) and MitoQ (6.5 μmol/kg) via tail vein 1 hour later,respectively.Rats in each group were given the same amount of normal sodium in addition to different intervention drugs.The cardiac function parameters were measured by a BL-420E + biosignal collection system.Blood samples from abdominal aorta were taken at each time point,and creatine kinase MB isoenzyme (CK-MB) content was detected by using the velocity method.The content of reactive oxygen species (ROS) in isolated myocardial tissues in rats was measured by enzyme-linked immunoadsorbent assay(ELISA).The protein expression of microtubule-associated protein 1 light chain 3 (LC3) was detected by Western blot method.The pathological changes of myocardial tissue were observed by light and electronic microscopy.Results Compared with the control group,the left ventricular systolic pressure(LVSP),the rate of the rise in left ventricular pressure (± dp/dt max) were significantly decreased in 6 h LPS group,6 h LPS + MitoQ group and 4 h LPS + Wortmannin group(P ＜0.05),left ventricular end-diastolic pressure(LVEDP) was significantly increased in these 3 groups(P ＜0.05).The contents of CKMB and ROS in 6 h LPS group,6 h LPS =MitoQ group and 4 h LPS + Wortmannin group were higher than those in the control group(P ＜ 0.05).Electron microscopy showed that the number of autophagic vacuoles increased 6 h after LPS was administered,but did not increase significantly thereafter to 12 h.There was no difference at any time point in the number of autophagic vacuoles in the group given MitoQ and LPS.Immunoblotting demonstrated that the levels of LC3Ⅱ protein in the LPS 6 h group and LPS + MitoQ 6 h group were higher than those in the control group(P ＜0.05),but there was no difference between the LPS 12 h and LPS 6 h groups (P ＞ 0.05).Conclusions The mitochondria-targeted antioxidant MitoQ does not prevent cardiac dysfunction.However,autophagy prevents cardiac dysfunction,and the autophagic capacity or autophagosome-formation rate may determine whether cardiac dysfunction develops.

Objective Mitochondrial dysfunction, cell energy metabolism, and oxidative stress play important roles in sepsis-induced acute brain injury.This study was to investigate the effects of Xingnaojing Injection (XNJ) on brain mitochondrial oxidative stress in rats with lipopolysaccharide (LPS)-induced sepsis.Methods Totally, 252 male SD rats were randomly divided into a normal control group, 3 LPS-induced sepsis model groups (LPS 6, 24, and 48 h), and 3 XNJ treatment groups (XNJ 6, 24, and 48 h), with 36 in each group.After treatment, the mitochondrial membrane potential (MMP) was monitored by flow cytometry and the levels of manganese superoxide dismutase (Mn-SOD), malondialdehyde (MDA), nitric oxide (NO), and nitric oxide synthase (NOS) were determined by chromatometry.Results The MMP was significantly increased in the XNJ 6 h group as compared with the LPS 6 h group (0.80±0.11 vs 0.54±0.19, P<0.05).In the LPS and XNJ groups, the levels of MDA and NOS reached the peak at 6 hours and then dropped gradually, while those of NO and Mn-SOD rose to the peak at 24 hours followed by a gradual fall.Statistically significant differences were observed in the levels of MDA, NOS and NO between the LPS 6h and XNJ 6 h groups (P<0.05), as well as in those of NOS, NO and Mn-SOD between the LPS 24 h and XNJ 24 h groups (P<0.05).Conclusion Xingnaojing Injection can elevate the level of the brain mitochondrial membrane potential, improve anti-oxidation indexes in the mitochondria, and protect brain mitochondria in sepsis rats.

BACKGROUND:Conditioned medium from mesenchymal stem cels (MSC-CM) may represent a promising alternative to MSCs transplantation. Previous studies have shown that inflammatory activation can strengthen the multiple biological potencies of MSCs; however, normal MSCs with insufficiency of immunocompetence and migration ability are not effective for tissue damage repair. OBJECTIVE:To investigate differential effects of MSC-CM with and without inflammatory activation on radiation-induced intestinal injury.METHODS:MSCs from the bone marrow of SD rats were separated, cultured and identified, and then co-cultured with non-irradiated IEC-6 or irradiated IEC-6 in a transwel system for 24 hours. Then, MSCs with inflammatory activation were cultured alone for another 48 hours. After that, the supernatant was colected as non-activated MSC-CM (MSC-CMNOR) and MSC-CM under radiation-induced inflammatory condition (MSC-CMIR). Rats were exposed to 14 Gy whole abdominal irradiation and randomly divided into four groups: control group, radiation injury group (DMEM/F12), MSC-CMNOR group and MSC-CMIR group. Continuous administration was givenvia tail vein and intraperitoneal implantation of Alzet microosmotic pumps. Intestinal samples were colected at 1, 3, 7 days after radiation for analysis of short circuit variation, at 3 days after radiation for analysis of intestinal epithelium ultrastructure, and at 1, 3, 5, 7, 14 days after radiation for histological observation of the intestinal epithelium using hematoxylin-eosin staining. Blood samples were colected at 1, 3, 7 days after radiation for analysis of serum xylose levels. In addition, the survival state and survival time of rats were observed and recorded. RESULTS AND CONCLUSION: The short circuit variation responding to electrical field stimulation was significantly reduced at al frequencies, but it was significantly improved in the MSC-CMIR group. Similarly, the intestinal absorption (serum xylose levels) was also significantly impaired by irradiation, but improved by delivery of MSC-CMIR (P < 0.05). At 3 days after MSC-CMIR infusion, the intestinal epithelium exhibited an increase in crypt size and vilous length (P < 0.05). Under the electron microscope, a reduction in intestinal microvili and open tight junctions in irradiated intestinal epithelium was found, and the intestine from rats treated with MSC-CMIR had more obvious tight junctions. In addition, treatment with MSC-CMIR dramaticaly improved the survival rate and mean survival time of irradiated rats as compared to those treated with DMEM/F12 or MSC-CMNOR (P < 0.05). Taken together, the present study demonstrated that MSC-CMIR , but not non-activated MSC-CM, improves the structural and functional restoration of the smal intestine after radiation-induced intestinal injury.

Uncoupling protein 2 (UCP2) is a proton transporter which presents in the mitochondrial inner membrane.Recently studies found that UCP2 plays important roles in regulation of reactive oxygen species production,maintenance of mitochondrial function,as well as inflammation and blood glucose control.These features have important relevance with the pathophysiologic mechanism of sepsis.