Immobilization of Multi-Enzymes on Support Materials for Efficient Biocatalysis.

Multi-enzyme biocatalysis is an important technology to produce many valuable chemicals in the industry. Different strategies for the construction of multi-enzyme systems have been reported. In particular, immobilization of multi-enzymes on the support materials has been proved to be one of the most efficient approaches, which can increase the enzymatic activity via substrate channeling and improve the stability and reusability of enzymes. A general overview of the characteristics of support materials and their corresponding attachment techniques used for multi-enzyme immobilization will be provided here. This review will focus on the materials-based techniques for multi-enzyme immobilization, which aims to present the recent advances and future prospects in the area of multi-enzyme biocatalysis based on support immobilization.

Effect of AAV9-hIGF-1 on inflammatory reaction in mdx mice and its mechanism.

This study aimed to the role of insulin-like growth factor 1 (IGF-1) in Duchenne muscular dystrophy (DMD), the inflammatory response and the potential mechanism of the effect hIGF1 exerted in muscle inflammation were also been explored. In this study, AAV9, a carrier of the human IGF-1 gene, was injected into mdx mice to observe the role of IGF-1 in DMD. Routine histopathological staining, immunofluorescence and western blot were used to detect the inflammatory response. In addition, we also explored the potential mechanism of the role of hIGF1 in muscle inflammation. The expression of AAV9 in myocardium and muscle tissue of AAV9-GFP group was detected by GFP method. GFP was expressed in different tissues of mdx mice, especially in anterior tibial muscle, triceps muscle and other tissues. The percentage of anterior tibial muscle inflammation area in CD68 and AAV9-hIGF-1 group was lower than that in AAV-GFP group, and the percentage of anterior tibial muscle inflammation area in AAV9-hIGF-1 group (1.78 ± 0.47%) was significantly lower than that in AAV GFP group (3.4 ± 1.22%) (P < 0.05). Western-blot showed that AAV-hIGF-1 group (0.45 + 0.07%) was lower than that of AAV-GFP group (0.76 + 0.13%), higher than the normal group (0.38 + 0.06%). The difference was statistically significant (P < 0.05). In conclusion, this study confirmed that hIGF-1 can reduce the inflammatory response and macrophage infiltration in mdx mice, and further proved that hIGF-1 can down regulate the expression of NF-κB signal pathway, which has anti-inflammatory effect.

scAAV9-VEGF-165 inhibits neuroinflammatory responses and invasion of macrophages into the peripheral nervous system of ALS transgenic mice.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder that leads to paralysis and death within 3-5 years. Although the vast majority of studies have focused on vulnerable neurons, growing evidence has shown that non-neuronal cells contribute to the pathogenesis and disease progression. Here, we showed that intrathecal injection of scAAV9-VEGF at 60 days of age significantly reduced the number of microglia and inhibited the neuroinflammatory response in the CNS. Meanwhile, we found that administration of VEGF inhibited the invasion of macrophages into the PNS, including ventral nerve roots, sciatic nerves and muscles. Overall, our study indicated the anti-inflammation effect of VEGF in the CNS and PNS of ALS mice when delivered by intrathecal injection.

Adeno-associated virus serotype 9 mediated vascular endothelial growth factor gene overexpression in mdx mice.

Duchenne muscular dystrophy (DMD) is a fatal neuromuscular disease caused by the absence of dystrophin. Vascular endothelial growth factor (VEGF) is a heparin-binding dimeric glycoprotein and principal angiogenic factor stimulating the migration, proliferation and expression of various genes in endothelial cells. Recently, VEGF was demonstrated to exhibit an antiapoptotic and direct myogenic effect, as well as to enhance muscle force restoration subsequent to traumatic injury. Therefore, the present study attempted to assess the muscle damage of VEGF overexpression in mdx mice. Adeno-associated virus serotype 9 (AAV9)-VEGF was administered intravenously to mdx mice. At 4 weeks after injection, VEGF was observed to be upregulated in the tibialis anterior muscle. In addition, the serum creatine kinase levels were significantly reduced and fatigue was slowed down, whereas the limb grip strength and weight of mice were markedly increased compared with the saline-treated mdx mice. Furthermore, significantly reduced inflammation and necrosis areas were observed in the muscle tissues of mice in the AAV9-VEGF group. These results suggested that AAV9-mediated VEGF gene overexpression was able to improve the muscle damage in mdx mice.