An analysis of the expression of collagen I and III genes in the fascia of obese patients.

BACKGROUND

The etiology of incisional hernias in the population of morbidly obese patients remains unclear. Most likely, factors other than purely mechanical are at play; it has been ascertained that nonobese patients suffering from inguinal and incisional hernias display alterations in the architecture of the connective tissue. The goal of this study has been to evaluate and compare the relative expression of collagen type I and III genes in the rectus abdominis muscle sheath (RMS) of obese and nonobese individuals to investigate their possible influence on the quality of the connective tissue.

MATERIALS AND METHODS

RMS specimens were harvested in the early stages of either bariatric or non-bariatric laparotomies; total RNA was isolated and enzymatically purified from the tissue samples. The resulting material was subjected to a quantitative and qualitative analysis; reverse transcription reactions were then performed and the resulting complementary DNA was used in real-time reverse transcription polymerase chain reactions. The biopsy specimens were also examined by scanning electron microscopy.

RESULTS

The real-time reverse transcription polymerase chain reactions, performed on complementary DNA, provided specific amplicons for individual genes. The efficacy of the reactions was rather low. An almost twofold decrease of the relative expression level for type I and III collagen was observed between the two patient groups; the results did not reach statistical significance. Scanning electron microscope photographs have documented a marked difference in the ultrastructure of the RMS in both groups.

CONCLUSIONS

The authors have shown that changes in messenger RNA levels for collagen type I and III genes may be related to the pathogenesis of incisional hernia through alterations in the ultrastructure of the RMS fascia. Our report should be considered preliminary; the results should be verified on a larger group of patients.