Medicina molecular y genética

The main objective of this study is development of chitosan supramolecular gels to utilize for oral delivery of insulin. Chitosan (CS) blended dextran sulfate (DS) matrix as nanogels were characterized by scanning electron microscopy and FT-IR. Equilibrium swelling studies were carried out in enzyme-free simulated gastric and intestinal fluids (SGF and SIF, respectively). Insulin entrapped in these gels and in vitro release profiles were established. In vitro release of insulin was also evaluated. The CS-DS gels have been developed based on the modulation of ratio show promise as a system for controlled delivery of the insulin to the stomach.

The adenovirus (Ad) genome encodes one or two non-coding small RNAs called virus-associated (VA)-RNAs, that are transcribed by polymerase III and support Ad replication. As previously reported, a replication-incompetent Ad vector, which is widely used in not only gene therapy studies, including clinical trials, but also basic researches as a gene delivery vehicle, as well as wild-type Ad (WT-Ad) express VA-RNAs, and VA-RNAs activate innate immunity, including the production of type I interferons. In addition, VA-RNAs perturb cellular microRNA (miRNA) expression profiles via competitive inhibition of key components involved in the miRNA maturation pathway. Although these characteristics of VA-RNAs might negatively affect the application of Ad vectors, VA-RNA expression profiles following transduction with an Ad vector have been not fully examined. In this study, we quantitatively analyzed the expression profiles of VA-RNAI, which is a major species of VA-RNAs, following transduction with Ad vectors in vitro and in vivo using real-time RT-PCR. The VA-RNAI expression levels in the cells transduced with a conventional Ad vector expressing luciferase (Ad-CAL2) at a multiplicity of infection (MOI) of 100 were approximately 2000- to 3000-fold lower than those infected with WT-Ad at the same MOI at 48 h after treatment. The expression levels of VA-RNAI in the mouse liver following administration with Ad-CAL2 were approximately 600-fold lower than those following administration with WT-Ad at 48 h post-administration. miRNA-mediated suppression of leaky expression of the Ad E4 genes resulted in about five-fold reduction in the VA-RNAI copy numbers in the liver following systemic administration in mice. These data provide informative clues for the development of novel safer Ad vectors.

Gene-environment interactions play a role in the development of obesity but specific effects of diet on the orosensory detection of fatty acids have yet to be clarified. The objective of this study is to characterize the effect of prolonged (5-week) exposure to a high-fat (60%) diet on the behavioral sensitivity to the fatty acid linoleate following a conditioned taste aversion in obesity-prone and obesity-resistant rats. Exposure to the high-fat diet significantly enhanced the sensitivity of obesity-resistant (S5B/Pl) rats to linoleate while producing no effect on the fatty acid sensitivity for obesity-prone rats. Specifically, high-fat diet fed S5B/Pl rats showed stronger initial avoidance of linoleate and slower extinction rates than their normal diet cohorts. Our study suggests that prolonged dietary fat consumption may alter the behavioral sensitivity to fatty acids particularly in obesity-resistant animals.

Diabetes is one of the most prevalent metabolic disorders. In diabetes, incidence of coronary artery diseases and peripheral vascular diseases is increased 2- to 4-fold and 10-fold, respectively, compared to healthy individuals. In spite of extensive studies, the underlying mechanisms of endothelial dysfunction (ED), an early event in the development of vascular diseases, remain incompletely understood in diabetes. This mini-review discusses the role and signaling pathways of calpains - a family of Ca2+-sensitive intracellular proteases in nitric oxide (NO)-mediated ED in diabetes. We conclude that activation of calpains, especially μ-calpain, plays an important role in the pathogenesis of NO-mediated ED and inflammatory responses in diabetes which is mainly via endothelial Nitric Oxide Synthase (eNOS) inactivation/degradation in macro- and micro-vasculature. We review existing literature demonstrating that hyperhomocysteinemia, elevated plasma homocysteine level, potentiates hyperglycemia-induced ED via μ-calpain/PKCβ2 activation-induced eNOS-pThr497/495 and eNOS inactivation. μ-calpain may be a critical therapeutic target for NO-mediated ED in diabetes.

Lactoferrin (LF) is known to show various useful biological features such as antimicrobial, antiviral, antitumor and anti-inflammatory effects. However, orally administered LF undergoes enzymatic degradation in the gastrointestinal tract, resulting in extensive decrease of such functions. The purpose of this study is to develop a useful oral delivery system of LF. Also, chitosan (Ch) was adopted as a carrier because it is yielded abundantly and a safe polymer. LF-loaded Ch microparticles were produced by the emulsification-evaporation technique using sorbitan sesquioleate (SO-15) and sorbitan trioleate (SO-30) as surfactants. The resultant LF-loaded Ch microparticles were evaluated from the viewpoints of particle size, shape, drug content and in vitro release in the gastric and intestinal pHs. The selected LF-loaded microparticles (MS4) were coated with an enteric coating polymer, Eudragit L100 (EL-100). The resultant microparticles (E/MS4) were protected from the deformation in the gastric pH, and exhibited fairly appropriate release profiles of LF. Thus, enteric-coated MS4 was suggested to be possibly useful as an orally-taken delivery system of LF.

Common-variable immunodeficiency (CVID) is a heterogeneous disorder characterized by recurrent bacterial infections, hypogammaglobulinemia, and impaired antibody responses. Patients with CVID can remain undiagnosed for many years but carry an increased risk for developing B cell derived non-Hodgkin’s lymphomas, such as Burkitt’s lymphoma. Screening for CVID in patients diagnosed with Burkitt’s lymphoma is necessary before prescribing treatments, because certain regimens may significantly increase the risk for flare-up of CVID that could result in prolonged immunodeficiency. We present a patient who was diagnosed with Burkitt’s lymphoma and sustained prolonged severe immunodeficiency after receiving a complete course of rituximab and chemotherapy treatment. This case report illustrates the need for an immunological work-up in lymphoma patients before initiation of treatment because of the increased incidence of lymphoma in patients with immunodeficiencies. Patients with lymphoma should also be monitored longitudinally for immunodeficiencies after treatment with rituximab with or without chemotherapy.