PRELIMINARY EVALUATION OF CALC-I GENE (CALCA) EXPRESSION IN TISSUE OF DOGS WITH PARVOVIRUS AND SYSTEMIC INFLAMMATORY RESPONSE SYNDROME (SIRS)

INTRODUCTION Procalcitonin (PCT) is a biomarker of sepsis. PCT gene, CALCA, expression is normally limited to the C cells of the thyroid, while it is reported to be ubiquitous in experimental models of sepsis. The aim of the study is to evaluate CALCA expression (mRNA) in a tissue-specific manner in diseases associated with naturally occurring sepsis in the dog, e.g. canine parvovirus. METHODS Tissues samples (thyroid, lung, liver, spleen) from dogs that died at the Veterinary Hospital of the University of Bologna with a diagnosis of parvoviral infection or SIRS, were collected and immediately stored at – 80°c. Total RNA was extracted by TRIZOL® Reagent according to the manufacturer’s protocol and converted to cDNA by Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) (Takara Bio Inc.). PCR was performed using oligonucleotides designed for the target gene and a TITANIUM ™ Taq DNA Polymerase (Clontech Laboratories, Inc.). PCR products were visualized by electrophoresis on a 2% agarose gel. RESULTS Tissues from 11 sick dogs (6 Parvovirus, 5 SIRS), plus one normal dog, were included. PCR for CALCA amplified the expected fragment, confirmed by sequencing, in the following samples: thyroid (11/11), spleen (6/11), lung (4/11), liver (3/11). Only thyroid expressed CALCA in the normal dog. CONCLUSION A qualitative PCR protocol for canine CALCA evaluation was established. An extra-thyroidal transcription of CALCA was shown for the first time in dogs. These results suggest a further study of CALCA expression by quantitative analysis (Real-Time PCR) in a wider population of SIRS and healthy dogs is warranted.