Omega-3 fatty acids impair miR-1-3p-dependent Notch3 down-regulation and alleviate sepsis-induced intestinal injury.

BACKGROUND: Sepsis is a troublesome syndrome that can cause intestinal injury and even high mortality rates. Omega-3 fatty acids (FAs) are known to protect against intestinal damage. Accordingly, the current study set out to explore if omega-3 FAs could affect sepsis-induced intestinal injury with the involvement of the microRNA (miR)-1-3p/Notch3-Smad axis. METHODS: First, cecal ligation and perforation (CLP) was performed to establish septic mouse models in C57BL/6J mice, and mouse intestinal epithelial MODE-K cells were induced by lipopolysaccharide (LPS) to establish sepsis cell models. The CLP-induced septic mice or LPS-exposed cells were subjected to treatment with Omega-3 FAs and activin (Smad signaling activator), miR-1-3p inhibitor and over-expressed/short hairpin RNA (oe-/sh)-Notch3 to explore their roles in inflammation, intestinal oxidative stress and cell apoptosis. A dual-luciferase reporter gene assay was further performed to verify the regulatory relationship between miR-1-3p and Notch3. RESULTS: Omega-3 FAs inhibited CLP-induced intestinal injury and ameliorated LPS-induced intestinal epithelial cell injury by down-regulating miR-1-3p, as evidenced by decreased levels of tumor necrosis factor-α, interleukin-1ß (IL-1ß) and IL-6, in addition to diminished levels of reactive oxygen species, malondialdehyde levels and superoxide dismutase activity. Furthermore, miR-1-3p could down-regulate Notch3, which inactivated the Smad pathway. CONCLUSION: Collectively, our findings indicated that omega-3 FAs elevate the expression of Notch3 by down-regulating miR-1-3p, and then blocking the Smad pathway to alleviate intestinal epithelial inflammation and oxidative stress injury caused by sepsis.

Surface loading of nanoparticles on engineered or natural erythrocytes for prolonged circulation time: strategies and applications.

Nano drug-delivery systems (DDS) may significantly improve efficiency and reduce toxicity of loaded drugs, but a few nano-DDS are highly successful in clinical use. Unprotected nanoparticles in blood flow are often quickly cleared, which could limit their circulation time and drug delivery efficiency. Elongating their blood circulation time may improve their delivery efficiency or grant them new therapeutic possibilities. Erythrocytes are abundant endogenous cells in blood and are continuously renewed, with a long life span of 100-120 days. Hence, loading nanoparticles on the surface of erythrocytes to protect the nanoparticles could be highly effective for enhancing their in vivo circulation time. One of the key questions here is how to properly attach nanoparticles on erythrocytes for different purposes and different types of nanoparticles to achieve ideal results. In this review, we describe various methods to attach nanoparticles and drugs to the erythrocyte surface, and discuss the key factors that influence the stability and circulation properties of the erythrocytes-based delivery system in vivo. These data show that using erythrocytes as a host for nanoparticles possesses great potential for further development.

microRNA-30a inhibits the liver cell proliferation and promotes cell apoptosis through the JAK/STAT signaling pathway by targeting SOCS-1 in rats with sepsis.

Sepsis is a systemic inflammatory response that may be induced by trauma, infection, surgery, and burns. With the aim of discovering novel treatment targets for sepsis, this current study was conducted to investigate the effect and potential mechanism by which microRNA-30a (miR-30a) controls sepsis-induced liver cell proliferation and apoptosis. Rat models of sepsis were established by applying the cecal ligation and puncture (CLP) method to simulate sepsis models. The binding site between miR-30a and suppressor of cytokine signaling protein 1 (SOCS-1) was determined by dual luciferase reporter gene assay. The gain-of-and-loss-of-function experiments were applied to analyze the effects of miR-30a and SOCS-1 on liver cell proliferation and apoptosis of the established sepsis rat models. The expression of miR-30a, SOCS-1, Janus kinase 2 (JAK2), signal transducer and activator of transcription 3 (STAT3), Bcl-2 associated X protein (Bax), B cell lymphoma-2 (Bcl-2), toll-like receptor 4 (TLR4), and high-mobility group box 1 (HMGB1), and the extent of JAK2 and STAT3 phosphorylation were all determined. Sepsis led to an elevation of miR-30a and also a decline of SOCS-1 in the liver cells. SOCS-1 was negatively regulated by miR-30a. Upregulated miR-30a and downregulated SOCS-1 increased the expression of JAK2, STAT3, Bax, TLR4, and HMGB1 as well as the extent of JAK2 and STAT3 phosphorylation whereas impeding the expression of SOCS-1 and Bcl-2. More important, either miR-30a elevation or SOCS-1 silencing suppressed liver cell proliferation and also promoted apoptosis. On the contrary, the inhibition of miR-30a exhibited the opposite effects. Altogether, we come to the conclusion that miR-30a inhibited the liver cell proliferation and promoted cell apoptosis by targeting and negatively regulating SOCS-1 via the JAK/STAT signaling pathway in rats with sepsis.

SP1 Promotes HDAC4 Expression and Inhibits HMGB1 Expression to Reduce Intestinal Barrier Dysfunction, Oxidative Stress, and Inflammatory Response after Sepsis.

As a serious and elusive syndrome caused by infection, sepsis causes a high rate of mortality around the world. Our investigation aims at exploring the role and possible mechanism of specificity protein-1 (SP1) in the development of sepsis. A mouse model of sepsis was established by cecal ligation perforation, and a cellular model was stimulated by lipopolysaccharide (LPS), followed by determination of the SP1 expression. It was determined that SP1 was poorly expressed in the intestinal tissues of septic mice and LPS-treated cells. Next, we examined the interactions among SP1, histone deacetylase 4 (HDAC4), and high mobility group box 1 (HMGB1) and found that SP1 bound to the HDAC4 promoter to upregulate its expression, thereby promoting the deacetylation of HMGB1. Meanwhile, gain- or loss-of-function approaches were applied to evaluate the intestinal barrier dysfunction, oxidative stress, and inflammatory response. Overexpression of SP1 or underexpression of HMGB1 was observed to reduce intestinal barrier dysfunction, oxidative stress, and inflammatory injury. Collectively, these experimental data provide evidence reporting that SP1 could promote the HDAC4-mediated HMGB1 deacetylation to reduce intestinal barrier dysfunction, oxidative stress, and inflammatory response induced by sepsis, providing a novel therapeutic target for sepsis prevention and treatment.

Polymeric antibacterial materials: design, platforms and applications.

Over the past decades, the morbidity and mortality caused by pathogen invasion remain stubbornly high even though medical care has increasingly improved worldwide. Besides, impacted by the ever-growing multidrug-resistant bacterial strains, the crisis owing to the abuse and misuse of antibiotics has been further exacerbated. Among the wide range of antibacterial strategies, polymeric antibacterial materials with diversified synthetic strategies exhibit unique advantages (e.g., their flexible structural design, processability and recyclability, tuneable platform construction, and safety) for extensive antibacterial fields as compared to low molecular weight organic or inorganic antibacterial materials. In this review, polymeric antibacterial materials are summarized in terms of four structure styles and the most representative material platforms to achieve specific antibacterial applications. The superiority and defects exhibited by various polymeric antibacterial materials are elucidated, and the design of various platforms to elevate their efficacy is also described. Moreover, the application scope of polymeric antibacterial materials is summarized with regard to tissue engineering, personal protection, and environmental security. In the last section, the subsequent challenges and direction of polymeric antibacterial materials are discussed. It is highly expected that this critical review will present an insight into the prospective development of antibacterial functional materials.