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A reprogrammable transgenic mouse strain, called Col1a1 4F2A‐Oct4‐GFP, was bred for the present study. Because the somatic cells of this mouse strain contain only two copies of each Yamanaka factor, these animals are inefficient at producing induced pluripotent stem cells (iPSCs; approx. 0.005%) under traditional culture conditions. With an optimized culture condition, the iPSC production rate of mouse embryonic fibroblasts (MEFs) of Col1a1 4F2A‐Oct4‐GFP mice (MEFCol1a14F2A‐Oct4‐GFP) was increased to approximately 8%. Further, promotion of cell proliferation by serum supplementation did not enhance iPSC production. Inhibition of transforming growth factor β (TGF‐β) in the serum by SB431542 neither affected the growth rate of MEFCol1a14F2A‐Oct4‐GFP nor promoted iPSC production. However, the use of the gamma‐irradiated STO‐NEO‐LIF (γSNL) cells to serve as feeders for iPSC production resulted in a 5‐fold higher rate of iPSC production than the use of γMEFICR feeders. Interestingly, the use of SB431542 with the γMEFICR‐adopted system could eliminate this difference. RT‐PCR‐based comparative analysis further demonstrated that TGF‐β expression was 10‐fold higher in γMEFICR than in γSNL cells. Consistent with previous reports, mesenchymal to epithelial transition was found to participate in the initial steps of reprogramming in the specific context of MEFCol1a14F2A‐Oct4‐GFP. Moreover, we found that the initial seeding density is one of the pivotal factors for determining a high efficiency of iPSC generation. The iPSCs efficiently generated from our MEFCol1a14F2A‐Oct4‐GFP resembled mouse embryonic stem cells (mESCs) in aspects of teratoma formation and germline transmission. Depending on the culture conditions, our Col1a1 4F2A‐Oct4‐GFP mouse system can generate bona fide iPSCs with variable efficiencies, which can serve as a tool for interrogating the route taken by cells during somatic reprogramming. [ABSTRACT FROM AUTHOR]

Many studies have reported the causes of obese metabolic syndrome (MS); however, the causes of nonobese MS (NMS) remain unknown. In this study, we demonstrated that inflamed dysfunctional adipose tissue plays a crucial role in cholesterol-induced NMS. Control (C), high cholesterol (HC) and HC with 10% fructose in drinking water (HCF) diets were fed to Sprague-Dawley rats for 12 weeks. After 12 weeks, the body weights of the C- and HC-fed rats were comparable, but the weights of the HCF-fed rats were relatively low. Cholesterol caused metabolic problems such as high blood pressure, hypercholesterolemia and hypoinsulinemia. The HCF-fed rats exhibited whole-body insulin resistance with low circulating high-density lipoprotein levels. Increases in the tumor necrosis factor α level in the plasma, the number of CD68+ macrophages and the free nuclear factor-κB level in gonadal white adipose tissue (gWAT) resulted in local inflammation, which appeared as inflamed dysfunctional gWAT. Reduced superoxide dismutases (SODs) deteriorate natural antioxidant defense systems and induce reactive oxygen species in gWAT. Dysregulation of plasma levels of catecholamine, adipokines (leptin and adiponectin), hormone-sensitive lipase and perilipin in cholesterol-induced inflamed adipose tissue contributed to increased lipolysis and increased circulating nonesterified fatty acids. Cholesterol activated inflammation, lipolysis and cell death in 3T3-L1 adipocytes. Moreover, Chol-3T3-CM reduced the population of M2-type Raw264.7 macrophages, indicating that the macrophage polarization is mediated by cholesterol. Together, our findings indicate that inflamed dysfunctional adipocytes are critical in NMS, supporting the development of anti-inflammatory agents as potential therapeutic drugs for treating NMS. [ABSTRACT FROM AUTHOR]

Much progress has been made in gene therapy, but significant challenges remain. One is development of a range of different tools that can be used for different therapeutic purposes. Another is site-specific gene targeting for safe and faithful therapeutic gene expression. Viruses have long been considered the most promising tools for human gene therapy. However, fatal side effects associated with viral vectors have hampered their clinical application. DNA transposons, widely utilized for decades as genetic tools in plants and insects, are now emerging as viable vectors for gene therapy. In this article, we will give a brief review of the adverse effects associated with virus-based gene therapy followed by a glimpse of the adeno-associated virus vector system, which is currently the most promising viral vector for gene therapy. The development of DNA transposon-based gene delivery systems and the advantages and limits of the most commonly used DNA transposon systems, Sleeping Beauty, Tol2, and piggyBac, will be extensively discussed Finally, we will focus on the most promising transposon system for gene therapy, piggyBac. Challenges and considerations for advancing piggyBac for therapeutic application will be critically addressed.