Hyperglycemia promotes vasculogenesis in choroidal neovascularization in diabetic mice by stimulating VEGF and SDF-1 expression in retinal pigment epithelial cells.

To investigate the influence of hyperglycemia on the severity of choroidal neovascularization (CNV) in diabetic mice, especially the involvement of bone marrow-derived cells (BMCs) and underlying molecular mechanisms. The mice were randomly divided into control group, diabetes group and diabetes treated with insulin group, which were laser treated to induce CNV. The CNV severity was evaluated by fundus fluorescein angiography, HE staining and choroidal flatmount. The BMCs recruitment and differentiation in CNV were examined in GFP chimeric mice by choroidal flatmount and immunofluorescence. The bone marrow-derived mesenchymal stem cells (BMSCs) recruitment and migration were tested in vivo and in vitro. VEGF and SDF-1 production in vivo and in vitro were tested by realtime PCR and ELISA. The CNV severity and expression of VEGF and SDF-1 were enhanced in DM mice compared with control mice and that insulin treatment decreased CNV severity in DM mice. The DM mice demonstrated more BMCs and bone marrow-derived mesenchymal stem cells (BMSCs) recruited and incorporated into CNV, increased ratio of BMCs expressing endothelial cell marker or macrophage marker, and up-regulated expression of VEGF and SDF-1 in CNV. Human BMSCs migration and expression of VEGF and SDF-1 in retinal pigment epithelial (RPE) cells increased when cultured under high glucose. This study suggested that hyperglycemia enhanced the expression of VEGF and SDF-1 in RPE cells, and promoted recruitment and incorporation of BMCs and affected differentiation of BMCs in CNV, which led to more severe CNV in diabetic mice.

Let-7b regulates alpaca hair growth by downregulating ectodysplasin A.

Hypohidrotic ectodermal dysplasia (HED), also known as anhidrotic ectodermal dysplasia, is characterized by the clinical manifestations of less sweat or no sweat, sparse or no hair, tooth agenesis and/or abnormal tooth morphology. The characteristics of alpaca ear hair differ from the back hair. The ectodysplasin A (EDA) signaling pathway has a regulatory effect on skin development and hair growth. The aim of the present study was to study the effects of EDA on alpaca hair growth by examining the mRNA and protein expression levels of EDA in alpaca ear and back skin by reverse transcription­quantitative polymerase chain reaction and western blot analysis, respectively. Results indicated that EDA expression was higher in the ear skin compared with the back skin. The expression levels of let­7b in the skin of healthy alpacas varies; the difference between let­7b expression levels of the ear and back have been reported to be >2­fold, suggesting a role for let­7b in the development of adult alpaca skin and hair follicles. A dual­luciferase reporter vector was constructed to verify the targeting relationship between microRNA let­7b and EDA, and the results revealed that EDA was a target gene of let­7b. Alpaca skin fibroblasts were transfected with a let­7b eukaryotic expression vector to investigate the regulatory relationship between let­7b and EDA. The expression of EDA was decreased in the transfected group; immunocytochemical results demonstrated that the EDA protein was abundantly expressed in the fibroblast cytoplasm. EDA protein expression was weaker in the transfected cells than in the untransfected cells. These results suggested that EDA may serve a role in alpaca hair growth and is probably a target gene of let­7b; let­7b downregulated EDA mRNA and protein expressions, which suggested that let­7b may regulate alpaca hair growth. These conclusions suggested that let­7b may be associated with HED.

Amelioration of osteoarthritis by intra-articular hyaluronan synthase 2 gene therapy.

Osteoarthritis (OA) is a chronic, degenerative disorder of multifactorial aetiology, characterized by loss of articular cartilage and periarticular bone remodelling. Goals of managing OA include controlling pain, maintaining and improving function and health-related quality of life, and limiting functional impairment. Although several managements had been proved to ameliorate the symptoms of osteoarthritis, no methods could cure it thoroughly. High-molecular-weight hyaluronan (HMW-HA) is a major component of synovial joint fluids which physically acts as a viscous lubricant for slow joint movements and as an elastic shock absorber during rapid movements. It also has a variety of biologic effects in vivo, such as inhibiting the release of inflammatory factors and suppressing the degradation of cartilage matrix. Intra-articular injection of synthetic HMW-HA has been used as viscosupplement for knee OA and its therapeutic efficacy has been verified. However, repeated injections of HMW-HA which is needed to control symptoms increase the probability of infection and sometimes there will have acute joint pain with effusion, which requires aspiration to exclude sepsis. In order to overcome the disadvantages of repeated injections of HMW-HA, novel strategies should be developed. As HMW-HA is synthesized by hyaluronan synthase-2 (HAS2), we postulate that HAS2 gene could be delivered into intra-articular cells by methods of gene therapy to achieve long-lasting synthesis of HMW-HA. In our opinion, this strategy seems to hold interesting future prospects for the treatment of OA.

Osteoprotective effect of cordycepin on estrogen deficiency-induced osteoporosis in vitro and in vivo.

The purpose of this study was to verify the effect of cordycepin on ovariectomized osteopenic rats. Fifty Wistar female rats used were divided into 5 groups: (1) sham-operation rats (control), (2) ovariectomized (OVX) rats with osteopenia, and (3) OVX'd rats with osteopenia treated with cordycepin (5 mg, 10 mg, and 20 mg) for 8 weeks. After the rats were treated orally with cordycepin, serum alkaline phosphatase (ALP), tartrate resistant acid phosphatase (TRAP), serum osteocalcin (OC), homocysteine (HCY) , C-terminal crosslinked telopeptides of collagen type I (CTX) level, and oxidative stress were examined, respectively. The femoral neck was used for mechanical compression testing. At the same time, we further investigated the effect of cordycepin in vitro assay. The beneficial effects of cordycepin on improvement of osteoporosis in rats were attributable mainly to decrease ALP activity, TRAP activity, and CTX level. At the same time, cordycepin also increases the OC level in ovariectomized osteopenic rats. The histological examination clearly showed that dietary cordycepin can prevent bone loss caused by estrogen deficiency. These experimental results suggest that complement cordycepin is protective after ovariectomized osteopenic in specific way.