Role of mitochondria in regulating micro RNA activity and its relevance to the central nervous system

Mitochondria serve as the powerhouse of cells,respond to cellular demands and stressors,and play an essential role in cell signaling,differentiation,and survival.Aberrant mitochondria function has been linked to diverse and complex human diseases such as neurodegenerative diseases,cancers,myopathies,premature aging,and metabolic syndromes（Nunnari and Suomalainen,2012）.

MicroRNA-regulated viral vectors for gene therapy

Safe and effective gene therapy approaches require targeted tissue-specific transfer of a therapeutic transgene.Besides traditional approaches, such as transcriptional and transductional targeting, micro RNA-dependent posttranscriptional suppression of transgene expression has been emerging as powerful new technology to increase the specificity of vector-mediated transgene expression. Micro RNAs are small non-coding RNAs and often expressed in a tissue-, lineage-, activation- or differentiation-specific pattern. They typically regulate gene expression by binding to imperfectly complementary sequences in the 3' untranslated region(UTR) of the m RNA. To control exogenous transgene expression, tandem repeats of artificial micro RNA target sites are usually incorporated into the 3' UTR of the transgene expression cassette, leading to subsequent degradation of transgene m RNA in cel s expressing the corresponding micro RNA. This targeting strategy, first shown for lentiviral vectors in antigen presenting cells, has now been used for tissue-specific expression of vector-encoded therapeutic transgenes, to reduce immune response against the transgene, to control virus tropism for oncolytic virotherapy, to increase safety of live attenuated virus vaccines and to identify and select cell subsets for pluripotent stem cell therapies, respectively. This review provides an introduction into the technical mechanism underlying micro RNA-regulation, highlights new developments in this field and gives an overview of applications of micro RNA-regulated viral vectors for cardiac, suicide gene cancer and hematopoietic stem cell therapy, as well as for treatment of neurological and eye diseases.

Macro-/micro-coupling regulation of nanoporous metals via vapor phase alloying-dealloying

Nanoporous metals with bicontinuous ligament-channel structure are of great importance in catalysis,electro-catalysis,actuation and energy storage and conversion.However,the intrinsic brittleness of nanoporous metals has always been the“Achilles heel”that impedes their practical applications.Utilizing the vapor pressure difference of metals,herein we propose a flexible and general vapor phase alloying(VPA)-dealloying strategy to fabricate nanoporous layers supported on the substrates with the same element.By adjusting the VPA time and temperature,the thickness and microstructure control over nanoporous layers can be realized by combining with diverse dealloying methods.Besides,various metals including Ag,Au,Cu,Co and Ni with different macro sizes and shapes can be fabricated into nanoporous structures through this method.More importantly,the greatly improved tensile ductility owing to the nanoporous layersubstrate structure and well enhanced catalytic performance for hydrogen evolution reaction of the as-fabricated nanoporous metals signify great potentials of the VPA-dealloying strategy for practical applications.