The deleterious effects of smoking in bone mineralization and fibrillar matrix composition.

Abstract

INTRODUCTION:

This study aimed to verify the effects of cigarette smoke exposure in bone mineralization and fibrillar matrix composition as well as in bone healing after tibial fracture induction.

METHODS:

C57Bl/6 Mice were assigned according to exposure and surgery: C room air; F room air and tibia open osteotomy; CS cigarette smoke; FCS cigarette smoke and tibia open osteotomy. In order to study fracture healing we performed, under anesthesia, a bone injury through a tibial shaft osteotomy. Bone samples were obtained to evaluate bone histomorphometry, trabecular morphology and volume, trabecular collagen types composition and presence of inflammatory cytokines and growth factors.

RESULTS:

CS exposure significantly reduced the thickness of bone trabeculae associated with decrease in mineralizing surface and mineral deposition rate, leading a lower bone formation rate and longer mineralization time. Resorption surface and osteoclastic surface were greater in the CS group, attesting increased resorptive action. There was a decrease in type I collagen deposition and genes expression in the CS and FCS groups compared to C group and in contrast there was an increase in type V collagen deposition and genes expression in the CS, FC and FSC groups compared to C group. Also, CS exposure induced a decrease in bone forming cytokines and an increase in inflammatory associated cytokines, and these changes were intensified under fracture conditions.

CONCLUSION:

Cigarette smoke exposure alters bone matrix composition and worsens bone mineralization, leading to bone fragility by increasing collagen V synthesis and deposition and impairing collagen I fibril forming and assembling. And these deleterious effects contributed to the worsening in fracture healing after tibia osteotomy.

• Authors: Alexandre Póvoa Barbosa, Juliana Dias Lourenço, Jader Joel Machado Junqueira, Silva Larissa Emidio de França, Janaina S Martins, Manoel Carneiro Oliveira Junior, Isadora Begalli, Ana Paula Pereira Velosa, Clarice Rosa Olivo, Thiago Bernardes Bastos, Vanda Jorgetti, Vieira Rodolfo de Paula, Walcy Rosolia Teodoro, Fernanda D T Q S Lopes
• Journal: Life sciences (Life Sci) Vol. 241 Pg. 117132 (Jan 15 2020) ISSN: 1879-0631 [Electronic] Netherlands
• PMID: 31837327 (Publication Type: Journal Article)
• Copyright: Copyright © 2019. Published by Elsevier Inc.

Chemical References

• Collagen Type I
• Cytokines
• Smoke

Topics

• Animals
• Calcification, Physiologic (drug effects)
• Cigarette Smoking (adverse effects)
• Collagen Type I (metabolism)
• Cytokines (metabolism)
• Male
• Mice
• Mice, Inbred C57BL
• Osteogenesis (drug effects)
• Smoke (adverse effects)
• Tibia (drug effects, injuries, metabolism, pathology)
• Tibial Fractures (etiology, metabolism, pathology)