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The NOS3 (27-bp repeat, intron 4) polymorphism is associated with susceptibility to osteomyelitis

Victor Asensi1, A Hugo Montes, Eulalia Valle

  • 1Infectious Diseases Unit, Hospital Central de Asturias, Oviedo University Medical School, Celestino Villamil s/n, 33006 Oviedo, Spain. vasensia@medynet.com <vasensia@medynet.com>

Nitric Oxide : Biology and Chemistry
|August 8, 2006
PubMed

Insights

A specific NOS3 gene variation (27-bp repeat, intron 4 polymorphism, allele 4) is linked to increased nitric oxide (NO) and higher osteomyelitis risk. This finding offers new insights into bone infection pathogenesis.

Area of Science:

  • Genetics
  • Immunology
  • Bone Biology

Background:

  • Nitric oxide (NO) produced by nitric oxide synthase (NOS) isoforms, NOS3 and NOS2, in osteoblasts and neutrophils contributes to bone loss.
  • Osteomyelitis (OM) is a chronic bone infection where NO dysregulation may play a role.

Purpose of the Study:

  • To investigate the association between specific polymorphisms in NOS3 and NOS2 genes and the risk of developing osteomyelitis.
  • To examine the relationship between these polymorphisms, serum NO levels, and NO production in neutrophils and osteoblasts in OM patients.

Main Methods:

  • Genotyping of NOS3 (intron 4, 27-bp repeat; promoter -786T/C; exon 7 E298D) and NOS2 (exon 22 G/A; microsatellites; promoter -954G/C) polymorphisms in 80 OM patients and 300 controls.
  • Measurement of serum NO levels.
  • Assessment of NO production in neutrophils and immunolabelling for NOS3 in osteoblasts from biopsy tissues.

Main Results:

  • Homozygosity for the NOS3 (27-bp repeat, intron 4 polymorphism) 4 allele was significantly more frequent in OM patients (p=0.044).
  • Higher serum NO levels were observed in OM patients with this specific NOS3 polymorphism.
  • Neutrophils from these patients produced more NO in response to bacterial stimuli.
  • NOS3 expression in osteoblasts correlated with bone inflammation, not specific polymorphisms.

Conclusions:

  • This study identifies a significant association between a specific NOS3 polymorphism (27-bp repeat, intron 4, allele 4) and an increased risk of osteomyelitis.
  • This NOS3 variant may influence NO production, contributing to the pathogenesis of OM.
  • Further research is warranted to elucidate the precise mechanisms linking this NOS3 polymorphism to bone infection susceptibility.

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