Introduction
RNA molecules have become a hot topic of research. While I was taught about messenger RNA (mRNA), ribosomal RNA (rRNA) and transfer RNA (tRNA), many more varieties have come into the nomenclature after I graduated with my science degrees. Even more interesting, these RNAs do not code for a protein, but instead have a role in regulating gene expression. From long non-coding RNA (lncRNA) to short interfering RNA (siRNA), microRNA (miRNA) and small nucleolar RNA (snoRNA), these classes of RNAs affect protein translation, whether by hindering ribosomal binding, targeting mRNA for degradation or even modifying DNA (e.g., methylation). This post will cover the topic of microRNAs, explaining what they are, how researchers understand their function and role in metabolism, cancer and cardiovascular disease, and some of the challenges in miRNA research.
What are microRNAs? MicroRNAs (miRNAs) are short noncoding RNAs 19–25 nucleotides long that play a role in protein expression by regulating translation initiation and degrading mRNA. miRNAs are coded as genes in DNA and transcribed by RNA polymerase as a primary transcript (pri-miRNA) that is hundreds or thousands of nucleotides long. After processing with a double-stranded RNA-specific nuclease, a 70–100 nucleotide hairpin RNA precursor (pre-miRNA) is generated and transported from the nucleus into the cytoplasm. Once in the cytoplasm, the pre-miRNA is cleaved into an 18- to 24-nucleotide duplex by ribonuclease III (Dicer). This cleaved duplex associates with the RNA-induced silencing complex (RISC), and one strand of the miRNA duplex remains with RISC to become the mature miRNA.
Continue reading “microRNA: The Small Molecule with a Big Story”
Cerebrospinal fluid (CSF) is a bodily fluid present around the brain and in the spinal cord. It acts as a protective cushion against shocks and participates in the immune response in the brain. Analysis of total CSF protein can be used for diagnostic purposes, as, for instance, a sign of a tumor, bleeding, inflammation, or injury. Considering the high value of CSF as a source of potential biomarkers for brain-associated damages and pathologies, the development of robust automated platform for CSF proteomics is of great value.
Honey bees are hard-working insects. Their pollination services are in such demand, humans tow hundreds of hives carrying millions of bees around in the back of semitrucks to bring honey bees to various locations such as California almond groves. Humans are also quite partial to the bee colony winter energy storage also known as honey. So while honey bees work hard to collect pollen and nectar from blooming plants and trees and store honey for the winter, humans insist on robbing the colony’s store of delicious sweetener for their own uses. Recent reports of high mortality in honey bee colonies has caused concern in many beekeepers who manage European honey bee apiaries for honey production and pollination services. These severe depletion of honey bee colonies have been attributed to the parasitic mite Varroa destructor in the colony, not only feeding off the larvae and pupae brooding in the colony but also transmitting viruses carried by the mite. Bee nutrition is important for the pollinators especially when overwintering in the hive. Without adequate nutrition, a colony may become weak and succumb to parasite or disease pressure, unable to survive until nectar and pollen are available in the spring. A study was recently published in PLOS ONE that examined how the landscape around Midwestern honeybee hives affected the ability of bees to overwinter and assessed their health by measuring levels of Varroa mites and honey bee viruses. 