Lingling Wei

Sichuan University, Chengdu, Sichuan Sheng, China

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Publications (13)41.54 Total impact

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    ABSTRACT: Islets are exceptionally susceptible to ischemia-reperfusion injury, an increased incidence of primary graft nonfunctionality, and β-cell death during a transplant procedure. Therefore, islets require protection during the early stages of the transplant procedure. Based on the beneficial vascular and anti-inflammatory activity of adiponectin, we hypothesize that the adiponectin protects islet cells against ischemia/reperfusion injury and graft dysfunction after transplantation. To examine the effects of adiponectin on the resistance of islet ischemia-reperfusion injury, we used the islet hypoxia-reoxygenation injury model and performed kidney subcapsular syngeneic islet transplants to assess the islets' vitality and function. Furthermore, we utilized lipopolysaccharide (LPS)-induced or tumor necrosis factor (TNF)-α-induced damage to islet cells to model the inflammation of post-transplant ischemia-reperfusion injury and transplanted islets in adiponectin-knockout (APN-KO) mice to explore whether the protective action of adiponectin is involved in TNF-α production and nuclear transcription factor-κB (NF-κB) activation. Adiponectin suppressed TNF-α production and IκB-α phosphorylation; decreased hypoxia-reoxygenation, LPS-induced and TNF-α-induced islet apoptosis; and improved islet function in vivo and in vitro. Our results demonstrate that adiponectin protects the islet from injury. We show that islet protection occurs in response to ischemia-reperfusion and is dependent on the suppression of islet production by TNF-α through cyclooxygenase (COX)-2 and the inhibition of the TNF-α-induced NF-κB activation pathways.
    Journal of Endocrinology 04/2013; · 4.06 Impact Factor
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    ABSTRACT: A short course of anti-CD45RB leads to long-term islet allograft survival and donor-specific tolerance in approximately half of immunocompetent mice. We have previously demonstrated that anti-CD45RB antibody-mediated tolerance requires B cells for cardiac allograft survival. We therefore asked whether B cells were also required for anti-CD45RB antibody-mediated survival of islets. Unexpectedly, we found that nearly 100% of islet allografts survive longterm in B cell-deficient mice. Similarly, B cell depletion by anti-CD22/cal augmented anti-CD45RB mediated tolerance when administered pre-transplant, although it had no effect on tolerance induction when administered post-transplant. Our results demonstrate that the role of B cells in promoting tolerance with anti-CD45RB is graft-specific, promoting tolerance in cardiac grafts but resisting tolerance in islet transplantation. These findings may help elucidate the varied action of B cells in promoting tolerance versus rejection.
    Cell Transplantation 11/2012; · 4.42 Impact Factor
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    ABSTRACT: BACKGROUND: Monkeys with insulin-dependent diabetes are important preclinical animal models for islet transplantation. Exogenous insulin should be administered to achieve good glycemic control and minimize the long-term vascular complications associated with diabetes until the graft function recovered completely. However, the effect of multiple daily injections of porcine or human insulin and the long-term effects of porcine insulin have not been studied in diabetic rhesus monkeys. METHODS: Diabetic rhesus monkeys, using a 6-month self-control insulin comparison experiment, were used to detect the incidence of adverse events and long-term diabetes complication events after long-term administration of porcine insulin. RESULTS: In this study, we found that a 20% higher dose of porcine insulin results in similar glycemic control as the human insulin regimen, and adverse events were seldom reported when porcine insulin was administered. Moreover, long-term injection with porcine insulin could delay the rate and severity of diabetes-related complications. CONCLUSIONS: Porcine insulin as a competent candidate for regular insulin therapy to maintain blood glucose levels in insulin-dependent diabetic monkeys during preclinical studies of islet transplantation.
    Journal of Medical Primatology 10/2012; · 1.11 Impact Factor
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    ABSTRACT: Islet transplantation has recently emerged as an acceptable clinical modality for restoring normoglycemia in patients with type 1 diabetes mellitus (T1DM). The long-term survival and function of islet grafts is compromised by immune rejection-related factors. Downregulation of factors that mediate immune rejection using RNA interference holds promise for improving islet graft resistance to damaging factors after transplantation. Here, we used a dual-purpose therapy/imaging small interfering (si)RNA magnetic nanoparticle (MN) probe that targets β-2 microglobulin (B2M), a key component of the major histocompatibility class I complex (MHC I). In addition to serving as a siRNA carrier, this MN-siB2M probe enables monitoring of graft persistence noninvasively using magnetic resonance imaging (MRI). Human islets labeled with these MNs before transplantation into B2M (null) NOD/scid mice showed significantly improved preservation of graft volume starting at 2 weeks, as determined by longitudinal MRI in an adoptive transfer model (P < 0.05). Furthermore, animals transplanted with MN-siB2M-labeled islets demonstrated a significant delay of up to 23.8 ± 4.8 days in diabetes onset after the adoptive transfer of T cells relative to 6.5 ± 4.5 days in controls. This study demonstrated that our approach could protect pancreatic islet grafts from immune rejection and could potentially be applied to allotransplantation and prevention of the autoimmune recurrence of T1DM in islet transplantation or endogenous islets.
    Diabetes 08/2012; · 7.90 Impact Factor
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    ABSTRACT: Baboons receiving xenogeneic livers from wild type and transgenic pigs survive less than 10 days. One of the major issues is the early development of profound thrombocytopenia that results in fatal hemorrhage. Histological examination of xenotransplanted livers has shown baboon platelet activation, phagocytosis and sequestration within the sinusoids. In order to study the mechanisms of platelet consumption in liver xenotransplantation, we have developed an in vitro system to examine the interaction between pig endothelial cells with baboon platelets and to thereby identify molecular mechanisms and therapies. Fresh pig hepatocytes, liver sinusoidal and aortic endothelial cells were isolated by collagenase digestion of livers and processing of aortae from GTKO and Gal+ MGH-miniature swine. These primary cell cultures were then tested for the differential ability to induce baboon or pig platelet aggregation. Phagocytosis was evaluated by direct observation of CFSE labeled-platelets, which are incubated with endothelial cells under confocal light microscopy. Aurintricarboxylic acid (GpIb antagonist blocking interactions with von Willebrand factor/vWF), eptifibatide (Gp IIb/IIIa antagonist), and anti-Mac-1 Ab (anti-α(M)β(2) integrin Ab) were tested for the ability to inhibit phagocytosis. None of the pig cells induced aggregation or phagocytosis of porcine platelets. However, pig hepatocytes, liver sinusoidal and aortic endothelial cells (GTKO and Gal+) all induced moderate aggregation of baboon platelets. Importantly, pig liver sinusoidal endothelial cells efficiently phagocytosed baboon platelets, while pig aortic endothelial cells and hepatocytes had minimal effects on platelet numbers. Anti-MAC-1 Ab, aurintricarboxylic acid or eptifibatide, significantly decreased baboon platelet phagocytosis by pig liver endothelial cells (P<0.01). Although pig hepatocytes and aortic endothelial cells directly caused aggregation of baboon platelets, only pig liver endothelial cells efficiently phagocytosed baboon platelets. Blocking vWF and integrin adhesion pathways prevented both aggregation and phagocytosis.
    PLoS ONE 01/2012; 7(10):e47273. · 3.73 Impact Factor
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    ABSTRACT: To develop a preclinical large animal model of autoimmune diabetes to facilitate the translational research of autoimmune diabetes in human. Nine young rhesus monkeys received multiple-low-dose (MLD) intravenous injections of streptozotocin for five consecutive days, followed by two additional boosting injections of STZ given 1 week apart. The induction of autoimmune diabetes was evaluated by regular metabolic testing, serological assessment of islet-reactive autoantibodies and histological examination of pancreatic tissues. Seven of nine treated animals became diabetic with moderate hyperglycemia initially and more severe hyperglycemia thereafter. All diabetic animals exhibited severely impaired glucose tolerance, limited islet function, and required insulin therapy to maintain relatively normal glucose metabolism and healthy status. Serological tests showed that all diabetic monkeys developed autoantibodies specifically against insulin and islet antigens. Furthermore, histological examination of the pancreata from diabetic animals revealed evidence of specific destruction of islet β cells and islets infiltrated with T lymphocytes. Overt and persistent diabetes can be induced in young rhesus monkeys by the injection of MLD-STZ, and autoimmune responses to pancreatic islet cells seem to be involved in the development of glucose intolerance and diabetes. These data indicate for the first time that autoimmune diabetes can be induced in primates; this may serve as a valuable preclinical model for studying the pathogenesis of and potential therapies for autoimmune diabetes in humans.
    Biochemical and Biophysical Research Communications 07/2011; 412(2):373-8. · 2.41 Impact Factor
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    ABSTRACT: Recent advances in human islet transplantation are hampered by significant graft loss shortly after transplantation and inability to follow islet fate directly. Both issues were addressed by utilizing a dual-purpose therapy/imaging small interfering RNA (siRNA)-nanoparticle probe targeting apoptotic-related gene caspase-3. We expect that treatment with the probe would result in significantly better survival of transplanted islets, which could be monitored by in vivo magnetic resonance imaging (MRI). We synthesized a probe consisting of therapeutic (siRNA to human caspase-3) and imaging (magnetic iron oxide nanoparticles, MN) moieties. In vitro testing of the probe included serum starvation of the islets followed by treatment with the probe. Caspase-3 gene silencing and protein expression were determined by RT-PCR and Western blot, respectively. In vivo studies included serial MRI of NOD-SCID mice transplanted with MN-small interfering (si)Caspase-3-labeled human islets under the left kidney capsule and MN-treated islets under the right kidney capsule. Treatment with MN-siCaspase-3 probe resulted in decrease of mRNA and protein expression in serum-starved islets compared with controls. In vivo MRI showed that there were significant differences in the relative volume change between MN-siCaspase-3-treated grafts and MN-labeled grafts. Histology revealed decreased caspase-3 expression and cell apoptosis in MN-siCaspase-3-treated grafts compared with the control side. Our data show the feasibility of combining siRNA therapy and in vivo monitoring of transplanted islets in mice. We observed a protective effect of MN-siCaspase-3 in treated islets both in vitro and in vivo. This study could potentially aid in increasing the success of clinical islet transplantation.
    Diabetes 02/2011; 60(2):565-71. · 7.90 Impact Factor
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    ABSTRACT: In order to anticipate and promptly treat hypoglycemia in diabetic monkeys treated with insulin or other glucose-lowering drugs, the relationships between the incidence and symptoms of hypoglycemia in these animals, and many factors involved in model development and sustainment were analyzed. Different procedures were performed on 22 monkeys for the induction of diabetes. The monkey models were evaluated by blood glucose, insulin, C-peptide levels and intravenous glucose tolerance tests. A glucose treatment program for the diabetic monkeys was administered and laboratory tests were regularly performed. A standard procedure of hypoglycemia treatment was established and the risk factors of hypoglycemia were analyzed by a logistic regression model. Furthermore, the relationships between the four methods of diabetes induction, renal function, glycemic control and hypoglycemia were studied using one-way analysis of variance and t-test. We found that the hypoglycemic conditions of diabetic monkeys were improved rapidly by our treatment. The statistical analysis suggested that the modeling methods, renal function and glycemic control were related to the incidence of hypoglycemia. In detail, the progress of diabetes, effects of glycemic control and, particularly, the severity of the hypoglycemia differed according to the induction strategy used. The models induced by partial pancreatectomy with low-dose streptozotocin were not prone to hypoglycemia and their glycemic controls were stable. However, the models induced by total pancreatectomy were more vulnerable to severe hypoglycemia and their glycemic controls were the most unstable. Moreover, the levels of blood creatinine and triglyceride increased after the development of diabetes, which was related to the occurrence of hypoglycemia. In conclusion, we suggested that total pancreatectomy and renal impairment are two important risk factors for hypoglycemia in diabetic monkeys. More attention should be paid to daily care of diabetic monkeys, particularly monitoring and protecting their renal function.
    Experimental Biology and Medicine 02/2011; 236(2):212-8. · 2.80 Impact Factor
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    ABSTRACT: Monkeys with insulin-dependent diabetes are important experimental models for islet xenotransplantation. However, with regard to diabetes induction, total pancreatectomy is a difficult operation with a high complication rate, while streptozotocin (STZ) administration may cause serious toxic effects and individual difference in metabolism. We compared two strategies involving pancreatectomy and STZ to successfully and safely induce diabetes in rhesus monkeys. Thirteen rhesus monkeys were divided into two groups: single high-dose STZ administration (80, 100 and 120 mg/kg, n = 3 for each dose) (group 1) and partial pancreatectomy (70-75%) combined with low-dose STZ (15 mg/kg, n = 4) (group 2). Induction of diabetes was evaluated by blood glucose, insulin, C-peptide, intravenous glucose tolerance test (IVGTT) and arginine stimulation test (AST). Detection of hematological and serum biochemical parameters and biopsies of pancreas, liver and kidney were periodically performed. In our study, animals in both groups developed diabetes. Serum C-peptide levels in groups 1 and 2 decreased to 0.08 +/- 0.07 and 0.35 +/- 0.06 nmol/L, respectively. IVGTT and AST indicated severely impaired glucose tolerance. Immunohistochemistry demonstrated that rare insulin-positive cells remained in the pancreas. In terms of STZ toxicity, four monkeys died 8-14 days after STZ administration (3 with 120 mg/kg STZ and 1 with 100 mg/kg STZ). Group 1 animals developed liver and kidney injury evidenced by increased alanine aminotransferase, aspartate aminotransferase, total cholesterol, LDL, triglyceride and blood urea nitrogen for one month, and histological abnormality including hepatic steatosis, renal glomerulus and tubular injury. Nevertheless, moderate histological injuries were seen in animals with 80 mg/kg STZ, with subsequent recovery. In contrast, group 2 animals displayed normal biochemical parameters and histology, with generally less risk of postoperative complications. We conclude that injection of 80 mg/kg STZ could induce diabetes with moderate injuries. Partial pancreatectomy with low-dose STZ is a safer and more reproducible method for inducing diabetes in rhesus monkeys.
    Experimental Biology and Medicine 07/2010; 235(7):877-85. · 2.80 Impact Factor
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    ABSTRACT: Rhesus monkey models are valuable to the studies of human biology. Reference values for clinical chemistry and hematology parameters of rhesus monkeys are required for proper data interpretation. Whole blood was collected from 36 healthy Chinese rhesus monkeys (Macaca mulatta) of either sex, 3 to 5 yr old. Routine chemistry and hematology parameters, and some special coagulation parameters including thromboelastograph and activities of coagulation factors were tested. We presented here the baseline values of clinical chemistry and hematology parameters in normal Chinese rhesus monkeys. These data may provide valuable information for veterinarians and investigators using rhesus monkeys in experimental studies.
    Xenotransplantation 12/2009; 16(6):496-501. · 2.57 Impact Factor
  • Lingling Wei, Yanrong Lu, Jingqiu Cheng
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    ABSTRACT: In the conventional treatments of type I diabetes, there are various problems. As a new adequate treatment of diabetes, cell replacement therapy of diabetes has been applied and given research priority. We have investigated the applications of cell transplantation in the treatment of diabetes and have retrieved the relevant articles on cells transplantation for the treatment of diabetes. In this paper, we review the history, development, merits and demerits of cell transplantation and the recent advances in pancreatic islet transplantation research. The latest progress in the induction of stem cell to differentiate into the insulin-producing cells was also introduced.
    Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi 10/2009; 26(5):1124-8.
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    ABSTRACT: We investigated the mechanism underlying the inhibitory effect of rat mesenchymal stem cells (MSCs) on non-specific mitogen-stimulated lymphocytes (LCs) and lymphoblasts (LBs). We used MSCs of passages 2-8 prepared from Sprague-Dawley (SD) rats. LCs were isolated from the spleens of SD rats. Mixed LCs reactions of mitomycin C-treated MSCs with concanavalin A (ConA)-stimulated LCs or LBs were performed, and the proliferation inhibition effect was tested by MTS assay. The cytotoxicity of MSCs against naïve and ConA-stimulated LBs was detected, after co-culturing for 24 h, by lactate dehydrogenase release assay. The rate of apoptosis of ConA-stimulated LBs was measured by flow cytometry after incubation with MSCs for 9 h in the ratio 10:1. The MSCs were treated with Fas ligand (FasL), transforming growth factor (TGF)-beta, and interleukin (IL)-10 blocking antibodies and co-cultured with ConA-stimulated LBs to observe the apoptosis and growth inhibitory effect. The main outcomes were bone marrow-derived adherent CD29+, CD44+, CD45-, CD54+, CD95+, and SH-2+ MSCs. FasL, TGF-beta, and IL-10 production by MSCs were visualized by immunocytochemical analysis. MSCs exhibited a dose-dependent growth inhibitory effect on ConA-stimulated LCs and LBs. When treated with anti-FasL and anti-IL-10 blocking antibodies, the inhibitory effect of MSCs on LBs proliferation, and the effect of apoptosis induction on LBs decreased. Anti-TGF-beta blocking antibody treatment did not significantly influence MSCs. Therefore, the inhibitory effects of MSCs against activated LBs were significantly stronger than that against naïve LCs. FasL and IL-10, rather than TGF-beta, play important roles in the immunosuppressive effects of MSCs.
    Cell Biochemistry and Function 10/2008; 26(8):900-7. · 1.85 Impact Factor
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    ABSTRACT: To explore good methods for isolation and purification of rat islets. The islets were isolated from male SD rat pancreata by a collagenase perfusion method and purified by a modified method: added 4 kinds of Euro-Ficoll of different densities (F1: D=1.132, F2: D=1.108, F4: D=l.069,F5: D=1.023), discontinuous density gradient centrifuge the tube at 2,000 r/min for 20 minutes at 4 degrees C, then the islets between F1 and F2 were collected. The purity of islets was assessed by dithizone staining with islets counted and scored for size. Islets viabil ity was assessed by fluorescin diacetate / propidium iodide. The function of purified islets was judged by the test of insulin release and islets transplantation. After an improved method for optimized isolation and purification, (920+/-122) IEQ purified islets were obtained from one rat. Boththe purity and viability of islets were over 90%. The amount of insulin secretion was (18.25+/-0.32) mU/L and (36.70+/-3.57) mU/L at 2.2 mmol/L and 22.2 mmol/L concentration of glucose respectively, there was significant difference between the two phases (P<0.05). The insulin release index was 2.01+/-0.15. Under 1,000 IEQ islets transplantation, the normal glucose level could be remained in diabetic rats. Highpurity and highviability islet cells can be got through improved collagenase perfusion and centrifugation on gradients method.
    Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery 02/2008; 22(1):75-9.