Shufa Li

Comparison of bone marrow mesenchymal stem cells with bone marrow-derived mononuclear cells for treatment of diabetic critical limb ischemia and foot ulcer: A double-blind, randomized, controlled trial

AIMS To identify better cells for the treatment of diabetic critical limb ischemia (CLI) and foot ulcer in a pilot trial. METHODS Under ordinary treatment, the limbs of 41 type 2 diabetic patients with bilateral CLI and foot ulcer were injected intramuscularly with bone marrow mesenchymal stem cells (BMMSCs), bone marrow-derived mononuclear cells (BMMNCs), or normal saline (NS). RESULTS The ulcer healing rate of the BMMSC group was significantly higher than that of BMMNCs at 6 weeks after injection (P=0.022), and reached 100% 4 weeks earlier than BMMNC group. After 24 weeks of follow-up, the improvements in limb perfusion induced by the BMMSCs transplantation were more significant than those by BMMNCs in terms of painless walking time (P=0.040), ankle-brachial index (ABI) (P=0.017), transcutaneous oxygen pressure (TcO(2)) (P=0.001), and magnetic resonance angiography (MRA) analysis (P=0.018). There was no significant difference between the groups in terms of pain relief and amputation and there was no serious adverse events related to both cell injections. CONCLUSIONS BMMSCs therapy may be better tolerated and more effective than BMMNCs for increasing lower limb perfusion and promoting foot ulcer healing in diabetic patients with CLI.

Prospective randomized controlled study of a Chinese herbal medicine compound Tangzu Yuyang Ointment for chronic diabetic foot ulcers: a preliminary report.

AIM OF THE STUDY The purpose of this study was to evaluate the efficacy and safety of a topical Chinese herbal medicine (CHM) compound Tangzu Yuyang Ointment (TYO) for treatment of chronic diabetic foot ulcers. MATERIALS AND METHODS This multi-center, prospective, randomized, controlled and add-on clinical trial was conducted at seven centers in the China mainland. Fifty-seven patients with chronic diabetic foot ulcers of Wagners ulcer grade 1-3 were enrolled in this study. Patients who were randomly assigned to the control group (n=28) received standard wound therapy (SWT), whereas those randomized to the treatment group (n=28) received SWT plus topical TYO. Only 48 patients who finished 24 weeks of observations were entered for data analysis. RESULTS The TYO and SWT groups were comparable for baseline characteristics. Ulcer improvement was 79.2% in the TYO group and 41.7% in the SWT group (P=0.017) at 12 weeks, and 91.7% vs. 62.5% (P=0.036) at 24 weeks. The number of ulcers that were completely healed at 4, 12 and 24 weeks was similar in both groups, as were the numbers of adverse events. Healing time was 96±56 days (n=19) in the TYO group and 75±53 days (n=14) in the SWT group (P=0.271). CONCLUSION TYO plus SWT is more effective than SWT in the management of chronic diabetic foot ulcers and has few side-effects.

Peroxisome Proliferator–Activated Receptor-γ Coactivator-1α (PGC-1α) Enhances Engraftment and Angiogenesis of Mesenchymal Stem Cells in Diabetic Hindlimb Ischemia

To examine whether the peroxisome proliferator–activated receptor-γ coactivator-1α (PGC-1α), a key regulator linking angiogenesis and metabolism, could enhance the engraftment and angiogenesis of mesenchymal stem cells (MSCs) in diabetic hindlimb ischemia, we engineered the overexpression of PGC-1α within MSCs using an adenoviral vector encoding green fluorescent protein and PGC-1α, and then tested the survivability and angiogenesis of MSCs in vitro and in vivo. Under the condition of hypoxia concomitant with serum deprivation, the overexpression of PGC-1α in MSCs resulted in a higher expression level of hypoxia-inducible factor-1α (Hif-1α), a greater ratio of B-cell lymphoma leukemia-2 (Bcl-2)/Bcl-2–associated X protein (Bax), and a lower level of caspase 3 compared with the controls, followed by an increased survival rate and an elevated expression level of several proangiogenic factors. In vivo, the MSCs modified with PGC-1α could significantly increase the blood perfusion and capillary density of ischemic hindlimb of the diabetic rats, which was correlated to an improved survivability of MSCs and an increased level of several proangiogenic factors secreted by MSCs. We identified for the first time that PGC-1α could enhance the engraftment and angiogenesis of MSCs in diabetic hindlimb ischemia.

Identification of novel HLA-A 0201-restricted cytotoxic T lymphocyte epitopes from Zinc Transporter 8.

Numerous evidences demonstrated that type 1 diabetes (T1D) is due to a loss of immune tolerance to islet antigens, and CD8(+) T cells play an important role in the development of T1D. Zinc Transporter 8 (ZnT8) has emerged in recent years as a target of disease-associated autoreactive T cells in human T1D. However, ZnT8-associated CTL specific-peptides have not been identified. In this study, we predicted and identified HLA-A*0201-restricted cytotoxic T lymphocyte (CTL) epitopes derived from ZnT8, and utilized it to immunize HLA-A2.1/Kb transgenic (Tg) mice. The results demonstrated that peptides of ZnT8 containing residues 107-115, 115-123 and 145-153 could elicit specific CTLs in vitro, and induce diabetes in mice. The results suggest that these specific peptides are novel HLA-A*0201-restricted CTL epitopes, and could have therapeutic potential in preventing of T1D disease.

MiR-130b promotes obesity associated adipose tissue inflammation and insulin resistance in diabetes mice through alleviating M2 macrophage polarization via repression of PPAR-γ

Inflammatory pathways play an important role in impaired glucose metabolism and insulin production. Adipose tissue inflammation is characterized by infiltration and expansion of macrophages, leading to type 2 diabetes (T2D). Macrophage polarization contributes to various inflammatory responses and cytokine production profiles. MiR-130b is involved in regulating immune response and metabolism. However, the specific role in macrophage polarization and glucose metabolism of T2D has not been reported. In this study, C57BL/6 mice were fed a high-fat diet to induce T2D mice model. The peritoneal macrophages were isolated, miR-130b and M1/M2 polarization was analyzed. Glucose tolerance was also detected. In addition, the relationship between miR-130b and the target gene was identified. We showed that mice fed on high-fat diet demonstrated significantly higher body weight and impaired glucose tolerance. In addition, the miR-130b level was up-regulated in macrophage of high-fat diet mice, which regulated M1/M2 polarization, adipose tissue inflammation and glucose tolerance. Furthermore, we identified PPAR-γ as a miR-130b target gene and regulated macrophage polarization. In summary, our findings demonstrated that miR-130b was a novel regulator of macrophage polarization and contributed to adipose tissue inflammation and insulin tolerance via repression of PPAR-γ. Furthermore, miR-130b represented a promising target for T2D therapy in the clinic.

Down-regulation of zinc transporter 8 in the pancreas of db/db mice is rescued by Exendin-4 administration

Recent human genetic studies have revealed that common variants of the zinc transporter 8 (ZnT-8) gene are strongly associated with type 2 diabetes mellitus (T2DM). ZnT-8 has been suggested as a potential candidate in the regulation of insulin secretion in pancreatic β-cells. In this study, we aimed to explore the expression of ZnT-8 in the development of T2DM. The expression of ZnT-8 was investigated in the pancreas and adipose tissue of homozygous db/db mice compared to heterozygous sibling db/+ mice (n=6-8). Furthermore, the effect of Exendin-4 (an analogue of glucagon-like peptide-1) on ZnT-8 expression was examined in the db/db mice. Exendin-4 or vehicle (control) was administered (i.p., 1 nmol/kg) to diabetic 8-week-old db/db mice daily for 14 days (n=8). The results revealed that ZnT-8 protein levels in the pancreas of db/db mice were reduced, accompanied by a decrease in ZnT-8 mRNA. ZnT-8 mRNA and protein levels were also significantly reduced in the epididymal and visceral fat of the db/db mice. Treatment with Exendin-4 up-regulated ZnT-8 gene expression in the pancreas of the db/db mice, but did not affect its expression in adipose tissue. These findings suggest that ZnT-8 synthesis in the pancreas and adipose tissue is down-regulated in db/db mice. Reduced ZnT-8 production in the pancreas may advance defects in insulin secretion in diabetes. These may be reversed, at least partially, by the administration of Exendin-4.

Dendritic cells expressing BTLA induces CD8+ T cell tolerance and attenuates the severity of diabetes

Numerous evidence demonstrate Type 1 diabetes (T1D) is due to a loss of immune tolerance to islet antigens, and CD8(+) T cells play an important role in the development of T1D in NOD mice. The novel coinhibitory receptor BTLA may have a regulatory role in maintaining peripheral tolerance, however, its role in autoimmune diabetes is unknown. To explore whether the generation of tolerance aiming at BTLA will help therapeutic intervention in T1D, the NOD mice were treated with genetically modified dendritic cells (DCs) expressing BTLA. The results demonstrated that transfer of modified DCs significantly induced CD8(+) T cell tolerance and attenuated the severity of diabetes. The findings suggest that genetically modified DC therapies enhancing the BTLA negative cosignal may prove valuable in treating T1D and other autoimmune diseases.

ZnT8107-115/HLA-A2 dimers attenuate the severity of diabetes by inducing CD8+ T cell tolerance

Recent studies demonstrated that activated CD8+ T cells contributed to the development of T1D, and Zinc Transporter 8 (ZnT8) has emerged as a target of autoreactive T cells in human T1D in recent years. In the previous work, we identified that ZnT8107-115 peptide as a candidate to generate CD8+ T cells and induce diabetes in mice. In addition, MHC-peptide complexes that interact with autoreactive T cells can induce immune tolerance. In the current study, we constructed ZnT8107-115/HLA-A2 dimers, and utilized them to immunize diabetes mice. The proliferation, cytotoxicity, and inflammatory cytokine of CD8+ T were analyzed, and the incidence and severity of diabetes were detected. We found that ZnT8107-115/HLA-A2 dimers inhibited proliferation, cytotoxicity, and inflammatory cytokine of CD8+ T. Additionally, ZnT8107-115/HLA-A2 dimers ameliorated the incidence and severity of diabetes mice. Our findings suggested that ZnT8107-115/HLA-A2 dimers abrogate pathogenic CD8+ T cells in diabetes, and the strategies represented promising way in T1D and other autoimmune diseases.

Gene silencing of ZnT8 attenuates inflammation and protects pancreatic tissue injury in T1D

T lymphocyte mediated inflammation contributes to the development of T1D. Zinc Transporter 8 (ZnT8) has emerged as a target of autoreactive T cells in human T1D in recent years. However, the regulating of ZnT8 in T1D has not been identified. We make a hypothesis that whether alternation of ZnT8 level could attenuate inflammation and protect pancreatic tissue injury in T1D. In this study, we utilized ZnT8 shRNA to inhibit ZnT8 expression, and detected inflammation, glucose tolerance and pancreatic tissue of NOD mice. We found that ZnT8 shRNA attenuated specific CD8+ T cell activation and cytotoxicity. In addition, ZnT8 shRNA protected glucose tolerance and pancreatic tissue injury via down-regulation of ZnT8 in NOD mice. Therefore, the results suggest that RNAi represents a promising target reducing ZnT8 mediated inflammation, and provides a novel therapeutical clue in T1D.