Chronic gastro-abdominal pain with altered bowel habits are associated with pathologies including gastroenteritis, autoimmune and inflammatory bowel disease, and irritable bowel syndrome (IBS). In IBS, diagnostic evidence of infection or inflammation are absent, yet symptoms nonetheless include chronic abdominal pain and alterations of stool frequency and consistency, with most common subtypes including diarrhea-predominant (IBS-D) or constipation predominant (IBS-C). [1, 2] IBS is a common clinical complaint in westernized nations, with females more frequently diagnosed than males [3]. Obesity is also associated with increased likelihood of chronic pain [4], and is associated with intestinal dysbiosis, and systemic inflammatory signatures [5]. Improving personalized medicine therefore requires patient stratification based on a combination of biological factors contributing to the individual’s symptom and biomarker spectrum. The “buffy coat” method isolates leukocytes and PBMCs from whole blood, comprises the immune cell population in peripheral blood. These cells are relatively inactive but are primed to respond to generalized and localized immune activation signals; they are under active investigation as diagnostic biomarkers [6]. Collection of buffy coat is a standard method in clinical laboratories; detection of immune activation via RNA expression biomarkers will be informative of differential biological response, and be tractable to collect in clinical settings. Results of differential expression, pathway analysis, and cell-type abundance analysis from buffy coat RNA, is presented here using variables for BMI, Gender, and IBS-subtype from publicly available Nanostring RNA expression and phenotypic data from the NCBI GEO database.

It is standard to identify and compare predicted protein sequence of the Drosha and Pasha genes subsidiary to detection and identification of novel microRNAs in newly sequenced taxa or review of previous deep sequencing data. Drosha and Pasha proteins are the key, conserved members of the ‘microprocessor’ protein complex which facilitates nuclear nuclear localized, pri to pre miRNA processing miRNAs of the canonical eumetazoan complement. Because of the necessity of the microprocessor for production of c anonical eumetazoan miRNA, the detection of both (1) bona fide microRNAs and (2) presence of Drosha/Pasha orthologs (or homologs) is often presented as sufficient to represent a functional canonical eumetazoan microRNA biogenesis pathway. However, the fun ctional role of the Drosha and Pasha homologs sometimes, though not always experimentally validated in non model taxa. Differentiation of ‘bona fide miRNAs’, opposed to ‘non bona fide’ small RNAs of similar size, are also necessary for miRNA identificatio n projects. Recent rubrics are based on structural and sequence elements of the miRNAs themselves, however these inclusion criteria include paraphyletic groupings of miRNAs, for example eumetazoan miRNAs and S treptophyte (green plant) miRNAs which are not produced by the Drosha/Pasha microprocessor mechanism. Therefore, a dichotomy exists between the structural definitions for miRNAs and understanding of the evolutionarily conserved function of the microprocessor and its components. In this article, I re view literature in the context of this topic and discuss philosophical significance for understanding the importance of the microprocessor in understanding the evolutionary and molecular origins of miRNA.