Turning Pro-inflammatory Cells Anti-inflammatory
H Karasuyama and M Egawa, Tokyo Medical and Dental University; Feb 22, 2013 (online); Immunity
This paper discusses the discovery of a mechanism by which pro-inflammatory cells are converted to anti-inflammatory cells, leading to reduced allergic skin inflammation. According to the abstract, inflammatory monocytes, the primary leukocytes recruited to skin lesions, express a chemokine receptor CCR2 in order to migrate into tissues such as the skin. Therefore, it was expected that CCR2-deficient mice would show reduced inflammation in the skin. However, increased inflammation was observed instead. When CCR2-expressing monocytes were re-introduced, inflammation decreased, indicating the inflammatory monocytes exerted an anti-inflammatory effect.
Previous studies showed that inflammatory monocytes differentiate into type 2 macrophages under the influence of a cytokine (interleukin-4) via one of two modes: differentiation from blood-circulating, resident monocytes; or differentiation from tissue-resident macrophages. This study identified a third mode: differentiation from blood-circulating inflammatory monocytes. Further elucidation of these mechanisms could promote the development of novel strategies to treat allergic inflammation.
THz Pulses Activate DNA Damage Response in Skin
LV Titova, AK Ayesheshim and FA Hegmann, University of Alberta; and A Golubov, D Fogen, R Rodriguez-Juarez and O Kovalchuk, University of Lethbridge; Mar 14, 2013; Biomedical Optics Express
According to this article abstract, the growing use of terahertz (THz) radiation for medical imaging and public security screening has raised questions regarding levels of exposure and health consequences. While picosecond-duration THz pulses show promise for diagnostic imaging, the effects of THz pulses on human cells and tissues remain largely unknown. Here, the authors investigated the biological effects of pulsed THz radiation on artificial human skin tissue.
Exposure to intense THz pulses for 10 min was found to significantly induce H2AX phosphorylation, indicating this irradiation may cause DNA damage in exposed skin tissue. However, a THz-pulse-induced increase in the levels of proteins responsible for cell-cycle regulation and tumor suppression also suggests that DNA damage repair mechanisms are quickly activated. Further, the authors found that cellular response to pulsed THz radiation was significantly different from that induced by exposure to UVA (400 nm).
Tailoring Adsorption and Size of Polymer and Carbon Spheres
NP Wickramaratne et al., Kent State University; and JM Ralph, Saint-Gobain NorPro; Mar 5, 2013; Langmuir
The work describes the preparation of cysteine-stabilized phenolic resin-based polymer and carbon spheres via the modified Stöber method. According to the article abstract, cysteine serves as a particle stabilizer. It provides nitrogen and sulfur hetero-atoms that can be introduced into said spheres to “tune” them to a range of 70–610 nm. This is accomplished by adjusting the cysteine amount and reaction temperature. Further, since the spheres thus contained sulfur and nitrogen hetero-atoms, they were tested for adsorption of copper ions. The researchers showed that adsorption isotherms recorded for copper ions could be well-fitted by Langmuir equation, giving adsorption capacities of up to ~65 mg/g.
Hes5-targeted siRNA to Regenerate Inner Ear Hair
JY Jung, University of Michigan and Dankook University; MR Avenarius, University of Michigan and Oregon Health and Science University; S Adamsky, E Alpert and E Feinstein, Quark Pharmaceuticals, Inc.; and Y Raphael University of Michigan; Feb 26, 2013; Molecular Therapy
This article discusses how notch signaling is active during the development, turnover and regeneration of epithelial sheets, and how it may be used to target specific genes. For example, hair cells lost from these sheets due to lesion were spontaneously generated by down-regulating the Hes5 gene using siRNA after a severe lesion, which trans-differentiated supporting cells and led to an increased production of new hair cells—significantly larger than the control treatment. The data suggests the notch signaling pathway is a potentially useful target for specific gene expression inhibition.
Drivers of Aging and Therapeutic Opportunities
CB Newgard et al., University of Texas Southwestern Medical Center; and NE Sharpless, University of North Carolina at Chapel Hill School of Medicine; Mar 1, 2013; J Clin Invest
This article describes mechanisms of aging, their relationship to human disease and approaches to regulate them. Specifically discussed are telomere dysfunction in senescence, sirtuin regulation of metabolism, the mechanistic target of the rapamycin (mTOR) signaling pathway, and the use of mTOR inhibitors to increase longevity. The decline of the immune system with age is considered, and age associated changes to pancreatic islet β-cells is specified as contributing to diabetes. According to the authors, an improved understanding of these molecular and genetic pathways underlying aging could make it possible to therapeutically target the aging process.
Chinese Hydrangea and the Immune System
M Whitman et al., Havard School of Dental Medicine; Feb 12, 2013; Nature Chemical Biology
According to Harvard Science, Chinese herbalists have traditionally treated malaria using a hydrangea root extract commonly known as chang shan. Recent studies suggest that halofuginone (HF), a compound derived from the bioactive ingredient of this extract, could be used to treat autoimmune disorders and reduce scar formation, among other benefits. HF has been shown to trigger a stress-response pathway that blocks the development of the harmful class of Th17 cells immune, which have been implicated in many autoimmune disorders.