Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2016 May;57(3):735-40.
doi: 10.3349/ymj.2016.57.3.735.

The Relationship between HIF-2α and VEGF with Radiographic Severity in the Primary Osteoarthritic Knee

Affiliations

The Relationship between HIF-2α and VEGF with Radiographic Severity in the Primary Osteoarthritic Knee

Zhou Jian-lin et al. Yonsei Med J. 2016 May.

Abstract

Purpose: The aim of this study was to determine the relationship of hypoxia-inducible factor-2 (HIF-2α) and vascular endothelial growth factor (VEGF) with radiographic severity in primary osteoarthritis (OA) of the knee. Expression of these two factors in cartilage samples from OA knee joints was examined at mRNA and protein levels.

Materials and methods: Knee joints were examined using plain radiographs, and OA severity was assessed using the Kellgren and Lawrence (KL) grading system. Specimens were collected from 29 patients (31 knees) who underwent total knee replacement because of severe medial OA of the knee (KL grades 3 and 4), 16 patients who underwent knee arthroscopy (KL grade 2), and 5 patients with traumatic knees (KL grade 0). HIF-2α and VEGF expression was quantified by real-time polymerase chain reaction and western blotting.

Results: Cartilage degeneration correlated with the radiographic severity grade. OA severity, determined using the Mankin scale, correlated positively with the KL grade (r=0.8790, p<0.01), and HIF-2α and VEGF levels with the radiographic severity of knee OA (r=0.7001, p<0.05; r=0.6647, p<0.05).

Conclusion: In OA cartilage, HIF-2α and VEGF mRNA and protein levels were significantly and positively correlated. The expression of both factors correlated positively with the KL grade. HIF-2α and VEGF, therefore, may serve as biochemical markers as well as potential therapeutic targets in knee OA.

Keywords: HIF-2α; KL grade; VEGF; cartilage degeneration.

PubMed Disclaimer

Conflict of interest statement

The authors have no financial conflicts of interest.

Figures

Fig. 1
Fig. 1. (A) Representative sections of cartilage from the femoral condyles (H&E staining). a: KL grade 0 group present normal cartilage with no evident changes; b: KL grade 2 group showing mild loss of height of articular cartilage; c and d: KL grade 3 and 4 groups increased flaking of cartilage, clefts deep to the radial zone, loss of coumnization of cellular distribution, and increased areas of hypocellularity. (B) Representative sections of cartilage from the femoral condyles (safranin-O staining). a: KL grade 0 group cartilage of normal showing anintact profile, and there is no evident loss of proteoglycan (PGs); b: KL grade 2 group showing light changes of PGs loss; c and d: KL grade 3 and 4 groups showing severe loss of PGs, and clefts deep to the radial zone. (C) The correlation between Mankin's score and KL grades (r=0.8790, p<0.01). KL, Kellgren and Lawrence; H&E, hematoxylin and eosin.
Fig. 2
Fig. 2. HIF-2α mRNA levels exhibited a positive correlation with radiographic severity of knee OA (r=0.7001, p<0.05); VEGF level was correlated with the radio-graphic severity (r=0.6647, p<0.05). HIF-2α, hypoxia-inducible factor-2; OA, osteoarthritis; VEGF, vascular endothelial growth factor; KL, Kellgren and Lawrence; GAPDH, glyceraldehyde phosphate dehydrogenase.
Fig. 3
Fig. 3. The expression of HIF-2α and VEGF protein were measured by Western blotting, and there were liner increased with the radio-graphic severity. HIF-2α, hypoxia-inducible factor-2; VEGF, vascular endothelial growth factor; KL, Kellgren and Lawrence; GAPDH, glyceraldehyde phosphate dehydrogenase.

References

    1. Hunter DJ, Felson DT. Osteoarthritis. BMJ. 2006;332:639–642. - PMC - PubMed
    1. Sharma L, Kapoor D. Epidemiology of osteoarthritis. In: Moskowitz RW, Altman RD, Hochberg MC, Buckwalter JA, Goldberg VM, editors. Osteoarthritis: Diagnosis and Medical/Surgical Management. 4th ed. Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins; 2007. pp. 3–26.
    1. Yang S, Kim J, Ryu JH, Oh H, Chun CH, Kim BJ, et al. Hypoxia-inducible factor-2alpha is a catabolic regulator of osteoarthritic cartilage destruction. Nat Med. 2010;16:687–693. - PubMed
    1. Pfander D, KÖrtje D, Zimmermann R, Weseloh G, Kirsch T, Gesslein M, et al. Vascular endothelial growth factor in articular cartilage of healthy and osteoarthritic human knee joints. Ann Rheum Dis. 2001;60:1070–1073. - PMC - PubMed
    1. Saito T, Fukai A, Mabuchi A, Ikeda T, Yano F, Ohba S, et al. Transcriptional regulation of endochondral ossification by HIF-2alpha during skeletal growth and osteoarthritis development. Nat Med. 2010;16:678–686. - PubMed

Publication types

MeSH terms

Substances