Inhibition of Bone Morphogenic Protein 4 Restores Endothelial Function in db/db Diabetic Mice

Abstract

Objective— Bone morphogenic protein 4 (BMP4) is involved in the development of endothelial dysfunction in hypertension. This study investigated whether the inhibition of BMP4 signaling improves endothelial function in db/db diabetic mice. Approach and Results— Male db/db mice were treated with noggin via osmotic pump infusion (1 µg/[h·kg –1 ]) for 2 weeks. Adenovirus BMP4-short hairpin RNA was introduced via tail vein injection at a dosage of 10 9 pfu/mouse and its effects were examined 7 days after. Vasoreactivity was studied on wire and pressure myograph. Both noggin treatment and adenovirus BMP4-short hairpin RNA transduction improved endothelium-dependent relaxations in aortae and flow-mediated dilatation in mesenteric arteries of db/db mice. Ex vivo treatment with BMP4 inhibitors and adenovirus BMP4-short hairpin RNA rescued the impaired endothelium-dependent relaxations in db/db mouse aortae and reduced reactive oxygen species overproduction determined by dihydroethidium staining, CM-H 2 DCFDA fluorescence imaging, and chemiluminescence assay in db/db mouse aortae, and also in ex vivo cultured C57BL/6 mouse aortae or primary mouse aortic endothelial cells treated with high glucose. Likewise, activin receptor–like kinase 3 silencing by short hairpin RNA lentivirus improved endothelium-dependent relaxations in db/db mouse aortae accompanied by reactive oxygen species inhibition in endothelial cells. In addition, noggin reduced BMP4 upregulation in high-glucose–treated endothelial cells and in C57BL/6 mouse aortae and in aortae from db/db mice. Conclusions— Inhibition of BMP4/activin receptor–like kinase 3/reactive oxygen species signaling improved endothelial function in diabetic mice through limiting oxidative stress in endothelium. Inhibiting BMP4 cascade can become another potential therapeutic strategy against diabetic vascular dysfunction.

Endothelium

“…54 Different strategies inhibiting BMP4 in diabetic db/db mice reduce reactive oxygen species production and rescued endothelium-dependent relaxations. 55 Similar findings are observed after inhibition of activin receptor-like kinase 3, a pathway downstream of BMP4 receptor. Regulation of the BMP4 pathway might therefore represent an interesting therapeutic strategy to fight endothelial dysfunction in diabetes mellitus.…”

Bone Morphogenic Protein 4-Smad–Induced Upregulation of Platelet-Derived Growth Factor AA Impairs Endothelial Function

“…12 Here we also found increase of plasma PDGF-AA in diabetic human and db/db mice. Importantly, we found that antagonizing PDGF-AA improves endothelium-dependent vasodilation in db/db mice, 12 indicating PDGF-AA as a new risk factor to cause vascular dysfunction. We also showed that inhibition of Smad1/5 and Smad4 abolished BMP4-induced PDGF-AA.…”

“…BMP4 is also involved in endothelial dysfunction of db/db mice. 12 Here we tested whether PDGF-AA is a risk factor leading to endothelial dysfunction in db/db mice as well. We found higher plasma level of PDGF-AA in diabetic patients (fasting glucose >7.0 mmol/L) compared with nondiabetic subjects ( Figure 5A), whereas PDGF-BB levels were similar ( Figure tolerance and insulin tolerance were similar between Ad-GFP (as control) and Ad-Pdgfa-shRNA-treated mice ( Figure VG and VH in the online-only Data Supplement).…”

“…11 In vivo inhibition of BMP4 restores endothelial function in diabetic db/db mice. 12 As one of numerous growth factors, platelet-derived growth factor (PDGF) was originally identified as platelets and serum mitogen for fibroblasts, smooth muscle cells (SMC), and glial cells. 13 PDGFs can also be secreted by endothelial cells, SMC, and fibroblast.…”

Upregulation of Angiotensin (1-7)-Mediated Signaling Preserves Endothelial Function Through Reducing Oxidative Stress in Diabetes

“…Changes of isometric tension of aortas were recorded in a wire myograph (Danish Myo Technology), and FMD was determined in a pressure myograph (60). For FMD study, the vessel diameter was continuously monitored on a lightinverted microscope (Zeiss Axiovert 40 Microscope, model 110P) through a video camera operated on the Myo-View system (Danish Myo Technology).…”