The biological function of type I receptors of bone morphogenetic protein in bone

Bone morphogenetic proteins （BMPs） have multiple roles in skeletal development, homeostasis and regeneration. BMPs signal via type I and type II serine/threonine kinase receptors （BMPRI and BMPRII）. In recent decades, genetic studies in humans and mice have demonstrated that perturbations in BMP signaling via BMPRI resulted in various diseases in bone, cartilage, and muscles. In this review, we focus on all three types of BMPRI, which consist of activin-like kinase 2 （ALK2, also called type IA activin receptor）, activin- llke kinase 3 （ALK3, also called BMPRIA）, and activin-like kinase 6 （ALK6, also called BMPRIB）. The research areas covered include the current progress regarding the roles of these receptors during myogenesis, chondrogenesis, and osteogenesis. Understanding the physiological and pathological functions of these receptors at the cellular and molecular levels will advance drug development and tissue regeneration for treating musculoskeletal diseases and bone defects in the future.

Influence of bone morphogenetic protein type IA receptor conditional knockout in lens on expression of bone morphogenetic protein 4 in lens

AIM: To investigate the influence of bone morphogenetic protein type IA receptor [BMPR-IA(ALK3)] conditional knockout in lens on expression of bone morphogenetic protein 4(BMP4) in lens during the development of the vertebrate eye.METHODS: Cre-positive mice were mated with Crenegative mice to generate 50% Cre-positive(conditional knockout, CKO) 4 embryos, 8 eyes and 50% Cre-negative offspring(wild type, WT) 4 embryos, 8 eyes. The embryos were fixed in 4% paraformaldehyde, embedded in paraffin, and sectioned to a thickness of 4 μm.Removal of paraffin wax and dehydrating for sections,and then the procedure of in situ hybridization was processed, BMP4 MK1784-m(BOSTER) was used, and observed the expression of BMP4 in the lens in experimental group and control group. We selected SPSS11.0 software for statistical analysis, P【0.05 showed that the difference was statistically significant.· RESULTS: Four embryos of each genotype were examined, totally we had 8 embryos, 16 eyes. We got the uniform outcomes in all the embryos. We found ALK3 was required during lens growing, but was not essential for the formation of lens. We observed that the expression of BMP4 in the lens was significantly reduced in all 8 ALK3 CKO lens, BMP4 expression was normal in all the 8 WT lens, P 【0.01. This phenomenon became increasingly visible in accordance with embryo development. The most apparent alteration was present at stage E15.5.CONCLUSION: ALK3 is essential for lens growth. The influence of ALK3 on the expression of BMP4 is present during the development of mice lens.

Involvement of BMP Signaling in Proliferation of Human Coronary Artery Endothelial Cells

Objectives To test the hypotheses that bone morphogenetic protein（BMP） signaling pathway components are expressed in arterial endothelial cells （ECs） and that BMP signaling influences endothelial cell（EC） proliferation. Methods We used cell culture and RT-PCR to determined mRNA expression of BMP receptors （BMPR）-IA, -IB, and II, Smads 1,4, 5, 6, and 7, and in cultured human coronary artery ECs at baseline and after stimulation with BMP2 （300 ng/mL for 6 hr）, non-radioactive cell proliferation to examine cell proliferation. Results Proteasome inhibition has been previously shown to enhance BMP signaling by preventing degradation of BMP pathway components. Therefore, identical experiments were also performed in the presence of the proteasome inhibitor epoxomicin. ECs expressed mRNA for BMPRs IA and II, Smads 1,4, 5, 6, 7, and stimulation with either BMP2 or epoxomicin resulted in a significant increase in EC proliferation measured after 48 hours in a dose-dependent fashion. Proliferation was accompanied by a marked increase in proliferating cell nuclear antigen （PCNA） expression. Toxicity was observed at high doses of epoxomicin. Conclusions All major BMP signaling molecules are expressed by vascular ECs and expression of these are affected by both BMP2 and epoxomicin. BMP2 may regulate EC proliferation, suggesting a possible role in vascular homeostasis and vascular pathologies involving EC denudation or proliferation.

Immunoadsorption therapy for Klinefelter syndrome with antiphospholipid syndrome in a patient:A case report

BACKGROUND Klinefelter syndrome(KS) is a genetic disease of male sex chromosome malformations that affects sperm production and reduces testosterone production. It has been reported that there is currently more than 10 cases of KS combined with antiphospholipid syndrome(APS).CASE SUMMARY Here, we describe a 31-year-old male patient with chromosome 47, XXY type, who suffered deep vein thrombosis of the lower limbs accompanied by abnormal antiphospholipid antibody, lupus anticoagulant and factor VⅢ. After treatment with immunoadsorption therapy, glucocorticoids, cyclophosphamide, intravenous immunoglobulin and anticoagulant therapy, the patient showed dramatic symptomatic improvement. During the follow-up, the patient did not develop any new thrombotic events.CONCLUSION Immunoadsorption combined with glucocorticoid and cyclophosphamide shock comprehensive treatment has achieved significant results for patients with KS combined with antiphospholipid syndrome.