Genes with greater up-regulation in the fracture callus of older rats with delayed healing.

J Orthop Res

Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Carolinas Medical Center, Charlotte, North Carolina 28232-2861, USA.

Published: April 2007

The rate of bone formation to bridge a fracture gap slows with age. To explore potential pathogenic mechanisms and possible negative-feedback responses by the skeleton to this reduced rate of healing, mRNA transcripts up-regulated more and/or longer were studied in older rats with delayed healing. Female rats at 6 (young), 26 (adult), and 52 (old) weeks of age received unilateral diaphyseal femoral fractures with intramedullary rod stabilization. At 0, 0.4, 1, 2, 4, and 6 weeks after fracture, the fracture site was harvested. Total RNA was extracted, cRNA was prepared, and the cRNA was hybridized to 54 Affymetrix U34A microarrays (three arrays/age/time point). Transcripts for 180 genes were identified as up-regulated more and/or longer in old rats with delayed fracture healing. Of these, 60 were selected for more intense review. Significantly more and/or longer expression was seen in genes related to myofibroblasts, cell proliferation, calcification inhibition, TGF-beta activity, lipid metabolism, cell adhesion, and the cytoskeleton. Further study is needed to determine if these up-regulated transcripts are related to the pathological processes which slow healing or are related to attempts by the fracture tissue to stimulate bone to bridge the fracture gap.

Download full-text PDF

Source
http://dx.doi.org/10.1002/jor.20334DOI Listing

Publication Analysis

Top Keywords

rats delayed
12
and/or longer
12
older rats
8
delayed healing
8
bridge fracture
8
fracture gap
8
up-regulated and/or
8
fracture
7
healing
5
genes greater
4

Similar Publications

This research seeks to address the gap in past studies by examining the role of the Nrf2 (nuclear factor erythroid 2-related factor 2) and HO-1 (heme oxygenase-1) signaling pathways in hypoxia and the potential effects of alpha-pinene on these factors. Wistar rats were divided into 7 experimental groups (n = 7): 1) control, 2 and 3) groups receiving alpha-pinene 5 and 10 mg/kg (i.p.

View Article and Find Full Text PDF

Background: In a previous study, we found that Atractylodes macrocephala and Paeoniae radix (AM-PR) was useful for the alleviation of functional constipation (FC). However, the precise mechanism underlying the compatibility between AM and PR in the treatment of FC remains uncertain. This study aims to analyze the pharmacokinetic differences in the active ingredients in the blood of rat models with FC when applied individually and in combination with AM-PR.

View Article and Find Full Text PDF

Purpose: Diffusion-weighted arterial spin labeling (DW-ASL) MRI has been proposed to determine the rate of water exchange (K) across the blood brain barrier (BBB). This study aims to further evaluate K MRI by comparing it with standard dynamic contrast-enhanced (DCE) MRI and histology in association with mannitol-induced disruption of the BBB.

Methods: DW-ASL was measured using a multiple b-value MRI protocol in normal rats at three post-labeling delays (N = 19), before and after intra-carotid injection of mannitol to disrupt BBB in one hemisphere (N = 13).

View Article and Find Full Text PDF

Age-related cataract (ARC) remains the leading cause of blindness worldwide. Sagittaria sagittifolia polysaccharide (SSP) extract, a key component of Sagittaria sagittifolia L., exhibits anti-oxidant and anti-apoptotic effects with potential applications in ARC.

View Article and Find Full Text PDF

Knee osteoarthritis (OA) is a common and debilitating disorder marked by joint degradation, inflammation, and persistent pain. This study examined the possible therapeutic effects of curcumin and vitamin D on OA progression and pain in a rat knee OA model by anterior cruciate ligament transection and meniscectomy (ACLT + MMx). Male Wistar rats were categorized into five groups: control, curcumin-treated (100 mg/kg/day), vitamin D-treated (25 µg/kg/day), a combination of vitamin D and curcumin, and sham-operated.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!