日大医学雑誌

Expression of Angiogenic Cytokines in the Chronic Ischemic
Hindlimb after Bone Marrow Mononuclear Cell Implantation

原著

著者

Tetsuya NAKAMURA, Noboru FUKUDA*, Yukihiro IKEDA*, Hisaki UMEZAWA and Nanao NEGISHI
Division of Cardiovascular Surgery, Department of Surgery, Nihon University School of Medicine
*Division of Nephrology and Endocrinology, Department of Medicine, Nihon University School of Medicine

要旨

Background: Recent studies have shown that bone marrow mononuclear cell (BM-MNC) implantation (BMI)increases collateral vessel formation in ischemic limb models and in patients with limb ischemia. To confirm therole of cytokines in therapeutic angiogenesis, we investigated changes in the expression of cytokines along withhistologic changes after BMI in a rat model of the chronic ischemic hindlimb.

Methods and Results: We subjected 150 Male Wistar rats to severe limb ischemia by resection of the leftfemoral artery. Saline as the control, or approximately 106 to 108 BM-MNCs were injected into the chronic ischemichindlimb area (n = 20 per group). Regional blood perfusion was evaluated by near-infrared reflectancespectroscopy. The expression levels of VEGF, bFGF, Flk-1, angiopoietin (Ang)-1, Ang-2, Tie-1, and Tie-2mRNAs in the ischemic hindlimb muscle after BMI were evaluated by RT-PCR analysis. The levels of VEGF andFlk-1 expression were examined by immunohistochemistry. BMI significantly increased blood flow in ischemicmuscle in a cell number-dependent manner. The levels of expression of VEGF and bFGF mRNAs increased significantlyin ischemic muscle after BMI. The levels of expression of Ang-1 mRNA decreased significantly,whereas that of Ang-2 mRNA increased significantly. The levels of expression of Flk-1, Tie-1, and Tie-2 mRNAsdid not change significantly. VEGF and Flk-1 were identified by immunostaining in the injected area and in thevessel wall of the ischemic muscle after BMI.

Conclusion: These findings suggest that BMI increased blood flow in rat chronic ischemic hindlimb muscle in acell number-dependent manner and induced angiogenesis as well as by inducing the expression of angiogeniccytokines, including VEGF, bFGF, and Ang-2, in the chronic ischemic tissue.

keyword

Bone marrow mononuclear cell; Angiogenesis; Near-infrared reflectance spectroscopy; VEGF;
Angiopoietin; Cytokine