[Show abstract][Hide abstract] ABSTRACT: The study aims to investigate the gene expression profiling of insulin signaling pathway and mitochondrial biogenesis and function in the skeletal muscle of KK mice.
KK mice were divided into the following groups: KK control group, basal medium (M199) only; KK fibroblast group, with human fibroblast transplantation; KK myoblast group, with human skeletal myoblast transplantation. C57BL mice received hSkM transplantation as a normal control. Cells were transplanted into mice hind limb skeletal muscle. All animals were treated with cyclosporine for 6 weeks only. The mice were sacrificed in a fasting state at 12 weeks after treatment. Hind limb skeletal muscle was harvested and used for study of gene expression profiling.
hSkMs survived extensively in mice skeletal muscle at 12 weeks after cell transplantation. Glucose tolerance test showed a significant decrease of blood glucose in the mice of KK myoblast group compared to the KK control and fibroblast groups. Transcriptional patterns of insulin signaling pathway showed alterations in KK myoblast as compared with KK control group (23 genes), KK fibroblast group (7 genes), and C57BL group (8 genes). Transcriptional patterns of mitochondrial biogenesis and function also had alterations in KK myoblast as compared with KK control group (27 genes), KK fibroblast group (9 genes), and C57BL group (6 genes).
These data demonstrated for the first time that hSKM transplantation resulted in a change of gene transcript in multiple genes involved in insulin signaling pathway and mitochondrial biogenesis and function.
No preview · Article · Aug 2013 · Diabetes research and clinical practice
[Show abstract][Hide abstract] ABSTRACT: The chronic inflammatory processes and endothelial dysfunction play important roles in the development of diabetic nephropathy (DN); the study aims to evaluate the effect of thymosin β4 (Tβ4), which has apparent anti-inflammatory properties and is capable of improving endothelial dysfunction, in early DN in a mouse model of type 2 diabetes mellitus. KK Cg-Ay/J (KK) mice, aged 12-14 weeks, were divided into the following groups: KK control group that was treated with saline; KK Tβ4 group that was treated with Tβ4 100 ng/10 g of intraperitoneal injection once a day. Nondiabetic age-matched C57BL mice were used as additional normal control and also treated with Tβ4. The urinary albumin/creatinine ratio (ACR), plasma urea nitrogen and creatinine, body weight, fasting blood glucose and 2-hour blood glucose during oral glucose tolerance testing, blood hemoglobin A1c, cholesterol, and triglyceride were determined at baseline time and 12 weeks after Tβ4 treatment for phenotypic characterizations. The KK Tβ4 group had reduced the mean fasting blood glucose, 2-hour blood glucose during oral glucose tolerance testing, hemoglobin A1c, and triglyceride levels compared with that in the KK control group (P < 0.05). Tβ4 treatment markedly reduced ACR (KK Tβ4 = 328.54 ± 46.14 mg/g vs. KK control = 540.34 ± 50.31 mg/g, P < 0.05). Tβ4 also significantly ameliorated renal pathological changes of KK Tβ4 mice as compared with that in KK control mice. Tβ4 treatment did not affect glucose homeostasis and urinary ACR and glomeruli of C57BL mice. These data in a novel mouse model of DN suggest that Tβ4 may ameliorate renal damage. This peptide may be a novel potential alternative agent for treatment of DN.
No preview · Article · Jul 2013 · American journal of therapeutics
[Show abstract][Hide abstract] ABSTRACT: To evaluate the efficacy of thymosin beta 4 (Tβ(4)) on hyperglycemia and insulin sensitivity in a mouse model of type 2 diabetes mellitus (T2DM).
KK mice were divided into the following groups: KK control group, with saline treatment; KK Tβ(4) group, with daily Tβ(4) 100ng/10g body weight intraperitoneal injection for 12 weeks. Non-diabetic C57BL mice were used as normal control. OGTT, plasma insulin, HbA1c, serum adiponectin, Tβ(4), cholesterol, and triglyceride were measured before and after Tβ(4) treatment. The phosphorylated AKT and total AKT protein levels of skeletal muscle from all groups were determined.
After Tβ(4) treatment, repeat OGTT showed a significant decrease in glucose profiles in the KK Tβ(4) group compared with the KK control group. The KK-Tβ(4) group had reduced mean HbA1c and triglyceride levels, and increased adiponectin compared with KK control group. C57BL mice showed normal glucose homeostasis. The phosphorylated AKT levels of skeletal muscle were significantly increased in KK Tβ(4) group compared with KK control group after glucose stimulation. C57BL mice showed no changes in phosphorylated AKT levels after Tβ(4) treatment.
Tβ(4) improved glucose intolerance and ameliorated insulin resistance in KK mouse. Tβ(4) may be a potential alternative insulin sensitizer for treatment of T2DM.
No preview · Article · Jan 2012 · Diabetes research and clinical practice
[Show abstract][Hide abstract] ABSTRACT: A regulated promoter system to control gene expression is desirable for safe and efficacious over-expression of therapeutic transgene. Combined with skeletal myoblast (SkMs), we report the efficacy of hypoxia-regulated VEGF gene delivery for myocardial repair during acute myocardial infarction (AMI). A hypoxia-regulated VEGF plasmid (pHRE-VEGF) was developed. After optimization, ∼30% SkMs were transfected using polyethyleneimine (PEI) nanoparticles. The peak VEGF expression was higher in pHRE-VEGF transfected SkMs ((VEGF)SkMs) under hypoxia (151.34 ± 8.59 ng/ml) than that with normoxia (16.92 ± 2.74 ng/ml). The efficacy of hypoxia-regulated gene expression system was assessed in a rabbit model of AMI. The animals were grouped to receive basal M199 without cells (group-1) or containing non-transfected SkMs (group-2) or (VEGF)SkMs (group-3). In group-4, (VEGF)SkMs were injected into normal heart to serve as normoxia control. Improved SkM survival was observed in group-3 and -4 (p < 0.05 vs group-2) at day-3 and 7 after transplantation. Blood vessel density was 20.1 ± 1.3 in group-3 which was significantly higher than any other groups (p < 0.05) at 2 weeks after treatment. Improved blood flow (ml/min/g) in the left ventricle (LV) anterior wall was observed in group-3 (1.28 ± 0.09, p < 0.05) as compared with group-1 (0.76 ± 0.05) and group-2 (0.96 ± 0.06), and similar to group-4 (1.26 ± 0.05). LV ejection fraction was best preserved in group-3 (58.4 ± 1.75%) which was insignificantly different from group-4 (61.1 ± 1.8%), and group-2 (52.8 ± 1.4%), but significantly improved compared with group-1 (44.7 ± 2.2%, p < 0.05). The study demonstrates that nanoparticle based delivery of hypoxia-regulated VEGF transgene combined with SkMs during AMI effectively preserves LV regional blood flow and contractile function of the heart.