Exosomes derived from mesenchymal stem cells overexpressing miR-210 inhibits neuronal inflammation and contribute to neurite outgrowth through modulating microglia polarization.

Inflammatory responses play a critical role in the progress of neurodegenerative disorders. MSC-Exos is considered to have an anti-inflammatory effect on the treatment strategy for brain injury. However, the therapeutic effect and possible mechanism of Exosomal miR-210 on microglia polarization-induced neuroinflammation and neurite outgrowth have not been reported. MSC-Exos were isolated by ultracentrifugation, identified by Nanosight NS300, transmission electron microscopy, and western bolt. In vitro, to explore the protective mechanism of MSC-Exos against neuroinflammation, the microglial BV2 cell was exposed to lipopolysaccharide to assess inflammatory changes. The intake of 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (Dil)-MSC-Exos into microglia was observed by fluorescence microscopy. The results showed that Exosomal miR-210 treatment significantly inhibited the production of nitric oxide and pro-inflammatory cytokines. Exosomal miR-210 treatment also increased the number of M2 microglia cells and inhibited M1 microglia polarization. In addition, western blot demonstrated that Exosomal miR-210 reduced neuronal apoptosis. Thus, Exosomal miR-210 attenuated neuronal inflammation and promoted neurite outgrowth. Exosomal miR-210 from MSCs attenuated neuronal inflammation and contributed to neurogenesis possibly by inhibiting microglial M1 polarization.

Engineered BMSCs-Derived Exosomal miR-542-3p Promotes Cutaneous Wound Healing.

BACKGROUND: The healing of cutaneous wounds requires better strategies, which remain a challenge. Previous reports indicated that the therapeutic function of mesenchymal stem cells is mediated by exosomes. This work demonstrated the regenerative effects of engineered BMSCsderived Exosomal miR-542-3p in skin wound mouse models. METHODS: Bone marrow mesenchymal stem cells (BMSCs) -derived exosomes (BMSCs-Exos) were isolated by ultracentrifugation and identified by Transmission Electron Microscope (TEM) and Nanoparticle Tracking Analysis (NTA). BMSCs-Exo was loaded with miRNA-542-3p by electroporation. We explored the effects of miRNA-542-3p-Exo on the proliferation and migration of Human Skin Fibroblasts (HSFs)/Human dermal microvascular endothelial cells (HMECs). In addition, The angiogenesis of HMECs was detected by Tube formation assay in vitro. The effects of miRNA-542-3p-Exo in the skin wound mouse model were detected by H&E staining, Masson staining, and immunofluorescence analysis. We assessed the effect of miRNA-542-3p-Exo on collagen deposition, new blood vessel formation, and wound remodeling in a skin wound mouse model. RESULTS: MiRNA-542-3p-Exos could be internalized by HSFs/HMECs and enhance the proliferation, migration, and angiogenesis of HSFs/HMECs in vitro and in vivo. The protein expression of collagen1/3 was significantly increased after miRNA-542-3p-Exo treatment in HSFs. In addition, the local injection of miRNA-542-3p-Exo promoted cellular proliferation, collagen deposition, neovascularization, and accelerated wound closure. CONCLUSION: This study suggested that miRNA-542-3p-Exo can stimulate HSFs/HMECs function. The treatment of miRNA-542-3p-Exo in the skin wound mouse model significantly promotes wound repair. The therapeutic potential of miRNA-542-3p-Exo may be a future therapeutic strategy for cutaneous wound healing.

Leptin improves intestinal flora dysfunction in mice with high-fat diet-induced obesity.

OBJECTIVE: This study investigated the effects of leptin on intestinal flora and inflammation in mice with high-fat diet (HFD)-induced obesity. METHODS: Mice were fed an HFD for 8 weeks; some were concurrently administered oral leptin for 4 weeks. Pathological changes in adipose tissue were detected using hematoxylin-eosin staining; endotoxin content in adipose tissue was measured by enzyme-linked immunosorbent assay. Intestinal flora were characterized by 16S bacterial rDNA sequencing. Levels of Toll-like receptor 4 (TLR4), nuclear factor-κB inhibitor α (IκB-α), and phosphorylated c-Jun N-terminal kinase (p-JNK) were detected by western blotting. RESULTS: Mice in the HFD group exhibited weight gain, elevated endotoxin content, and adipocyte hypertrophy, compared with the non-obese control group. Moreover, abundance of bacteria in the Bacteroides genus and community diversity were both reduced in the HFD group; reductions also were observed at corresponding phylum, class, and order levels. Levels of TLR4, IκB-α, and p-JNK were also elevated in the HFD group. Compared with the model group, leptin administration reduced the weight gain and endotoxin content, while increasing Bacteroides abundance and community diversity; it also reduced the levels of TLR4, IκB-α, and p-JNK. CONCLUSION: Leptin administration improved intestinal flora dysfunction and inflammation in mice with HFD-induced obesity.

[The nasal development after one-staged correction of nose deformity and unilateral complete cleft lip in infancy].

OBJECTIVE: To introduce one-staged correction of nasal deformity and unilateral complete cleft lip in infancy and to observe the nasal development after the operation. METHODS: The unilateral complete cleft lip and nasal deformity were corrected in one stage in27 cases. They were followed up for several years. With post-operative photos, the anthropometric method was used to analyze the nasal development. RESULTS: The long-term results were excellent in 10 cases, good in 14 cases, and poor in 3 cases. CONCLUSIONS: Based on the anatomic findings of nasal blood supply, one-staged correction of nasal deformity and unilateral complete cleft lip in infancy can be performed with no obvious interference with nasal development. The secondary nasal deformity before school age can be alleviated or avoided.

Mouse Models of Metastatic Pancreatic Adenocarcinoma.

Pancreatic adenocarcinoma is a deadly disease. Its etiology is unknown, and metastatic disease kills themajority of patients who have it. Effective prevention is clearly the ultimate goal for eradicating this diseaseprovided that the effects of environmental and genetic elements on pancreatic cancer development arefully understood. Currently, it appears that the control of pancreatic cancer metastasis is of immediateurgency. Fulfillment of this difficult task relies on knowledge of the cellular and molecular biology of metastasis.The use of relevant animal models will help define each aspect of this complicated process.

A Novel, Clinically Relevant Animal Model of Metastatic Pancreatic Adenocarcinoma Biology and Therapy.

In this study, we report a metastatic model of Panc02 murine pancreatic adenocarcinoma. Parental Panc02cells were orthotopically implanted into the pancreas of syngeneic C57BL/6 mice. Tumor cells were isolatedfrom liver micrometastases 90 d after tumor implantation and established as a culture (Panc02-H1).The Panc02-H1 cells were then implanted into the pancreas of mice. Liver metastases were then collectedand established as Panc02-H2 cells. This process was repeated until the Panc02-H7 cell line was established.These cells were extremely aggressive after implantation as manifested by progressive growth in the pancreas,peritoneal dissemination, and distant metastasis to multiple organs, including the liver and lungs.Moreover, Panc02-H7 cells expressed the inducible nitric oxide synthase gene at a very low level in cultureand produced highly vascularized tumors having a large number of infiltrating macrophages. Collectively,this model system should be a valuable tool for investigating the molecular mechanisms governing pancreaticcancer growth and metastasis and exploring potential treatment modalities for this disease.