Debin Lu

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.

Progress in stem cell therapy for the diabetic foot

The diabetic foot is a common and severe complication of diabetes comprising a group of lesions including vasculopathy, neuropathy, tissue damage and infection. Vasculopathy due to ischemia is a major contributor to the pathogenesis, natural history and outcome of the diabetic foot. Despite conventional revascularization interventions including angioplasty, stenting, atherectomy and bypass grafts to vessels, a high incidence of amputation persists. The need to develop alternative therapeutic options is compelling; stem cell therapy aims to increase revascularization and alleviate limb ischemia or improve wound healing by stimulating new blood vessel formation, and brings new hope for the treatment of the diabetic foot.

PGC-1α prevents apoptosis in adipose-derived stem cells by reducing reactive oxygen species production in a diabetic microenvironment

AIMS To examine whether overexpression of peroxisome proliferator activated receptor-gamma coactivator-1 alpha (PGC-1α) can prevent apoptosis in adipose-derived stem cells (ASCs) by reducing reactive oxygen species (ROS) production and enhancing mitochondrial function in a diabetic environment. METHODS After the isolation, expansion and characterisation of rat ASCs, we overexpressed PGC-1α in ASCs using an adenoviral vector encoding green fluorescent protein (GFP) or PGC-1α and tested the apoptotic effect under conditions of high glucose, hypoxia and serum deprivation. The production of intracellular ROS and mitochondrial ROS was evaluated using dihydroethidium and CM-H2XRos fluorescent probes. RESULTS Under conditions of high glucose, hypoxia and serum deprivation, the overexpression of PGC-1α in ASCs decreased apoptosis and led to an increased survival rate. The ASCs modified with PGC-1α produced lower intracellular and mitochondrial ROS. The mitochondrial morphology and structure in the PGC-1α-ASC group remained relatively complete compared with the control group. CONCLUSIONS These results reveal a crucial protective role for PGC-1α in the treatment of diabetes mellitus and its complications using stem cells therapy.

Transcutaneous oxygen pressure (TcPO2): A novel diagnostic tool for peripheral neuropathy in type 2 diabetes patients

AIMS The assessment of transcutaneous oxygen pressure (TcPO2) may serve as a non-invasive and lower-cost alternative to nerve conduction studies (NCSs) for the diagnosis of diabetic peripheral neuropathy (DPN). The aim of this study was to determine whether the measurement of TcPO2 is useful for evaluating DPN. METHODS We performed a cross-sectional study of 381 consecutive hospitalized diabetic patients classified by clinical examination and NCS as having DPN. Anthropometric and metabolic parameters were assessed. The TcPO2 examination was performed in both supine and sitting positions. RESULTS Three hundred and one patients had DPN. The TcPO2 in both the supine and sitting positions was highest in the Non-DPN group and lower in the confirmed DPN group than the other three groups (p<0.001). The Non-DPN group had the lowest sitting-supine position difference in TcPO2 among the groups (p<0.001). The risk factors strongly associated with DPN included sitting-supine position difference in TcPO2 (OR=4.971, p<0.001), diabetic retinopathy (DR) (odds ratio [OR]=3.794, p=0.002), and HbA1c (OR=1.534, p=0.033). The area under the curve (AUC) of the sitting-supine position difference in TcPO2 was 0.722 and revealed an optimal cut-off point for the identification of DPN (19.5 mmHg) that had a sensitivity of 0.611 and a specificity of 0.738 based on AUC analysis. CONCLUSIONS This large study of diabetic patients confirms that the sitting-supine position difference in TcPO2 is higher in DPN patients than control subjects, indicating that TcPO2 examination is a promising valuable diagnostic tool for DPN.

Peroxisome Proliferator-Activated Receptor-γ Coactivator-1α (PGC-1α) Regulates the Expression of B-Cell Lymphoma/Leukemia-2 (Bcl-2) and Promotes the Survival of Mesenchymal Stem Cells (MSCs) via PGC-1α/ERRα Interaction in the Absence of Serum, Hypoxia, and High Glucose Conditions

Background To study the effect of estrogen-related receptor α (ERRα) and peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) on mesenchymal stem cells (MSCs) apoptosis, and further investigated its detailed molecular mechanisms in the absence of serum, hypoxia, and high glucose conditions. Material/Methods In our study, we first evaluated the expression rates of CD14, CD34, CD45, CD44, CD29, and Sca-1 surface markers on MSCs by flow cytometry. Then, the ability of osteogenic and fatty differentiation of MSCs was determined by osteogenic differentiation and adipogenesis reagent kit. Next, Annexin V-APC/7-AAD apoptosis kit was used for detecting the apoptosis rate of MSCs. RT-PCR and Western blotting were used for detection of mRNA expression and proteins expression, respectively. Results Our data showed that the MSCs used in our study were capable of self-renewal and differentiating into many cell lineages, such as osteogenic differentiation and adipogenesis. Our results further showed that over-expression of PGC-1α could protect MSCs from apoptosis induced by rotenone. We also found that PGC-1α over-expression could enhance the expression of anti-apoptotic gene Bcl-2, and inhibit the expression of pro-apoptotic gene Bax in MSCs. In addition, our data demonstrated that PGC-1α could induce upregulation of Bcl-2 and further promote the survival of MSCs by interacting with ERRα. Conclusions In the absence of serum, hypoxia and high glucose conditions, PGC-1α can regulate the expression of Bcl-2 and promote the survival of MSCs via PGC-1α/ERRα interaction.

Efficacy and long-term longitudinal follow-up of bone marrow mesenchymal cell transplantation therapy in a diabetic patient with recurrent lower limb bullosis diabeticorum

Bullosis diabeticorum is a rare presentation of cutaneous manifestation most commonly affecting the lower limbs in patients with diabetes. The appearance, often as insidious as its resolution, is characterized by tense blisters on the skin surfaces of the lower limbs and the feet. The cause still remains unclear, but it may relate to microangiopathy and neuropathy. In this report, we present a case of a 64-year-old male with multiple episodes of blistering in the left lateral lower limb after a traumatic fall who was subsequently diagnosed with type 2 diabetes mellitus. The patient had a history of poorly controlled blood glucose and subsequently developed vasculopathy and peripheral neuropathy. Despite appropriate glycemic control and antibiotics therapy, the patient developed recurrent bullosis diabeticorum on five separate occasions during a 2-year span from 2005 to 2007. Building on our success with ischemic diabetic foot, we used bone marrow mesenchymal stem cell (BMMSC) transplantation therapy for bullosis diabeticorum. After a 9-month treatment, this patient developed another episode of cellulitis in the same lower limb which was successfully treated with antibacterial therapy. It is interesting that the patient reported no recurrence in the next 10-year follow-up span. This study demonstrates that bullosis diabeticorum could appear even before the onset of diabetes, and vascular insufficiency predisposes to the occurrence of bullosis diabeticorum. Our findings suggest that autologous BMMSC transplantation therapy may be an effective measure for recurrent bullosis diabeticorum; however, this will require further investigation to be conclusive. Early identification of diabetes and its complications and appropriate treatment may improve clinical outcomes and prevent lower limb amputation.Trial registration: ClinicalTrials.gov Identifier: NCT00955669. Registered on August 10, 2009.