Nitric oxide synthase isoforms expression in fibroblasts isolated from human normal peritoneum and adhesion tissues

Area of Science:

• Cell Biology
• Molecular Biology
• Physiology

Background:

• Nitric oxide synthases (NOSs) play crucial roles in cellular function.
• Differential expression of NOSs may exist between normal peritoneal fibroblasts (NF) and adhesion fibroblasts (ADF).
• The impact of hypoxia on NOS expression and nitric oxide (NO) production in these cells is not fully understood.

Purpose of the Study:

• To investigate the expression levels of neuronal NOS (nNOS), endothelial NOS (eNOS), and inducible NOS (iNOS) in human NF and ADF.
• To determine how hypoxia modulates the expression of NOS isoforms and NO production in these fibroblast types.

Main Methods:

• Fibroblasts were isolated from human peritoneal (NF) and adhesion tissues (ADF).
• Reverse-transcriptase polymerase chain reaction (RT-PCR) was used to quantify NOS mRNA levels.
• Griess assay was employed to measure nitric oxide (NO) concentrations.
• Gene silencing of iNOS was performed to assess its contribution to NO production.

Main Results:

• nNOS and eNOS mRNA levels were similar between NF and ADF.
• iNOS mRNA levels were significantly higher in both NF and ADF compared to nNOS and eNOS.
• Hypoxia markedly increased iNOS mRNA expression and NO levels in both NF and ADF.
• ADF exhibited lower basal NO levels compared to NF.
• Silencing iNOS significantly reduced NO levels in both NF and ADF.

Conclusions:

• Human peritoneal fibroblasts and adhesion fibroblasts exhibit distinct patterns of NOS expression, with iNOS being the predominant isoform.
• iNOS is the primary source of NO in both NF and ADF.
• Hypoxia significantly upregulates iNOS expression and NO production in peritoneal and adhesion fibroblasts.