Biological significance of C-reactive protein, the ancient acute phase functionary.

C-reactive protein (CRP) is one of the major members of the family of acute phase proteins (APP). Interest in this CRP was the result of a seminal discovery of its pattern of response to pneumococcal infection in humans. CRP has the unique property of reacting with phosphocholine-containing substances, such as pneumococcal C-polysaccharide, in the presence of Ca2+. The attention regarding the origin of CRP and its multifunctionality has gripped researchers for several decades. The reason can be traced to the integrated evolution of CRP in the animal kingdom. CRP has been unequivocally listed as a key indicator of infectious and inflammatory diseases including autoimmune diseases. The first occurrence of CRP in the evolutionary ladder appeared in arthropods followed by molluscs and much later in the chordates. The biological significance of CRP has been established in the animal kingdom starting from invertebrates. Interestingly, the site of synthesis of CRP is mainly the liver in vertebrates, while in invertebrates it is located in diverse tissues. CRP is a multifunctional player in the scenario of innate immunity. CRP acts as an opsonin in the area of complement activation and phagocytosis. Interestingly, CRP upregulates and downregulates both cytokine production and chemotaxis. Considering various studies of CRP in humans and non-human animals, it has been logically proposed that CRP plays a common role in animals. CRP also interacts with Fcγ receptors and triggers the inflammatory response of macrophages. CRP in other animals such as primates, fish, echinoderms, arthropods, and molluscs has also been studied in some detail which establishes the evolutionary significance of CRP. In mammals, the increase in CRP levels is an induced response to inflammation or trauma; interestingly, in arthropods and molluscs, CRP is constitutively expressed and represents a major component of their hemolymph. Investigations into the primary structure of CRP from various species revealed the overall relatedness between vertebrate and invertebrate CRP. Invertebrates lack an acquired immune response; they are therefore dependent on the multifunctional role of CRP leading to the evolutionary success of the invertebrate phyla.

Vector-free in vivo trans-determination of adult hepatic stem cells to insulin-producing cells.

A reduction in the number of functional ß-cells is the central pathological event in diabetes. Liver and ventral pancreas differentiates simultaneously in the same general domain of cells within embryonic endoderm. In addition, the precursor cell population being bi-potential may be targeted for either pancreas or liver development. Hepatic stem cells were redirected in vivo to functional insulin producing cells in a acetylaminofluorene-partial hepatectomy (AAF/PH) adult male rat model with/without GLP-1 treatment. In routine H&E histology and immunohistochemistry, stem cells resembled ß cells in GLP-1 injected rats. Immunoblots revealed involvement of adenylate cyclase, TLR4 and PDX1 in insulin synthesis. Expression of genes (GLP-1R, MAFA, PDX1, INS1 and INS2) augmented in the GLP-1 treated regenerated liver. Results strongly indicated the key role of GLP-1 in the induction of insulin secretion in trans-determined reprogrammed cell in vivo. The present method being vector free poses no risk of vector spillover in the host and holds promise.