Mao Quan Li

To explore whether or not inhibition of protein kinase C βII (PKC βII) stimulates angiogenesis as well as prevents excessive NETosis in diabetics thus accelerating wound healing. Streptozotocin (STZ, 60 mg/kg/day for 5 days, i.p.) was injected to induce type I diabetes in male ICR mice. Mice were treated with ruboxistaurin (30 mg/kg/day, orally) for 14 consecutive days. Wound closure was evaluated by wound area and number of CD31-stained capillaries. Peripheral blood flow cytometry was done to evaluate number of circulating endothelial progenitor cells (EPCs). NETosis assay and wound tissue immunofluorescence imaging were done to evaluate the percentage of neutrophils undergoing NETosis. Furthermore, the expression of PKC βII, protein kinase B (Akt), endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF), and histone citrullation (H3Cit) were determined in the wound by Western blot analysis. Ruboxistaurin accelerated wound closure and stimulated angiogenesis in diabetic mice. The number of circulating EPCs was increased significantly in ruboxistaurin-treated diabetic mice. Moreover, ruboxistaurin treatment significantly decreases the percentages of H3Cit⁺ cells in both peripheral blood and wound areas. This prevented excess activated neutrophils forming an extracellular trap (NETs) formation. The expressions of phospho-Akt (p-Akt), phospho-eNOS (p-eNOS), and VEGF increased significantly in diabetic mice on ruboxistaurin treatment. The expressions of PKC βII and H3Cit⁺, on the other hand, decreased with ruboxistaurin treatment. The results of the present study suggest that ruboxistaurin by inhibiting PKC βII activation, reverses EPCs dysfunction as well as prevents exaggerated NETs formation in a diabetic mouse model; thereby accelerating the wound healing process.

Diabetic foot ulcer's impaired wound healing, which leads to the development of chronic non-healing wounds and ultimately amputation, is a major problem worldwide. Although recently endothelial progenitor cell-derived cell therapy has been used as a therapeutic intervention to treat diabetic wounds, thereby promoting neovascularization, the results, however, are not satisfactory. In this article, we have discussed the several steps that are involved in the neovascularization process, which might be impaired during diabetes. In addition, we have also discussed the reported possible interventions to correct these impairments. Thus, we have summarized neovascularization as a process with a coordinated sequence of multiple steps and thus, there is the need of a combined therapeutic approach to achieve better treatment outcomes.

Background: Diffusion-weighted imaging (DWI) derived apparent diffusion coefficient (ADC) has demonstrated inconsistent results in pulmonary nodule differentiation. Diffusion kurtosis imaging (DKI), which quantifies non-Gaussian diffusion, is believed to better characterize tissue micro-structure than conventional DWI. Purpose: To assess the feasibility of DKI in human lungs and to compare its diagnostic value with standard DWI in differentiating malignancies from benign pulmonary nodules. Material and Methods: Thirty-five pulmonary nodules in 32 consecutive patients were evaluated by DKI by using 3b-values of 0, 500, and 1000 s/mm² and conventional DWI with b values of 0 and 800 s/mm². Two observers independently evaluated and compared diagnostic accuracy of mean kurtosis (MK) and ADC values in differentiating malignancies from benign pulmonary nodules. The intra- and inter-observer repeatability (intra-class correlation coefficient [ICC]) were also assessed for each derived measures. Results: The diagnostic accuracy, and the area under curve (AUC) in differentiating malignancies from benign pulmonary nodule, were not significantly higher for MK (Obs. 1a: 85.70%, 0.87; Obs. 1b: 80.00%, 0.80; and Obs. 2: 82.80%, 0.91) as compared to ADC (Obs. 1a: 77.14%, 0.81; Obs. 1b: 80.00%, 0.85; and Obs. 2: 77.14%, 0.85 respectively). The intra- and inter-observer agreement (ICC) for malignant and benign lesions was substantial for each reading. Conclusion: The initial results of this study indicate the feasibility of DKI in human lungs. However, there was no significant benefit of DKI derived MK values over ADC for malignant and benign pulmonary nodule differentiation.

To provide estimates of the diffusional kurtosis in different anatomical regions of a healthy brain and to assess age dependency of diffusion kurtosis imaging (DKI) and diffusion tensor imaging (DTI) derived parametric values in these regions.