Human Leptin R(Leptin receptor) ELISA Kit

Metabolic diseases like diabetes mellitus cause bone healing deficiencies. We found significant impairment of bone regeneration, osteogenic differentiation and proliferation in diabetic bone. Moreover recent studies suggest a highly underestimated importance of GDF8 (Myostatin) in bone metabolism. Our goal was to analyze the role of GDF8 as a regulator of osteogenic differentiation, proliferation and bone regeneration. We used a murine tibial defect model in diabetic (Lepr(db-/-)) mice. Myostatin-Inhibitor Follistatin was administered in tibial bony defects of diabetic mice. By means of histology, immunohistochemistry and QRT-PC osteogenesis, differentiation and proliferation were analyzed. Application of Myostatin-inhibitor showed a significant improvement in diabetic bone regeneration compared to the control group (6.5 fold, p < 0.001). Immunohistochemistry revealed a significantly higher proliferation (7.7 fold, p = 0.009), osteogenic differentiation (Runx-2: 3.7 fold, p = 0.011, ALP: 9.3 fold, p < 0.001) and calcification (4.9 fold, p = 0.024) in Follistatin treated diabetic animals. Therapeutical application of Follistatin, known for the importance in muscle diseases, plays an important role in bone metabolism. Diabetic bone revealed an overexpression of the catabolic protein Myostatin. Antagonization of Myostatin in diabetic animals leads to a restoration of the impaired bone regeneration and represents a promising therapeutic option.

Background/objective: Intervertebral disc degeneration (IDD) remains to be an intractable clinical challenge. Although IDD is characterised by loss of notochordal cells (NCs) and dysfunction of nucleus pulposus (NP) cells, little is known about the origin, heterogeneity, fate and maintenance of NCs and NP cells, which further stunts the therapeutic development. Thus, effective tools to spatially and temporally trace specific cell lineage and clarify cell functions in intervertebral disc (IVD) development and homoeostasis are urgently required. Methods: In this study, NP specimens were obtained from 20 patients with degenerative disc disease or scoliosis. LepR-Cre mice was crossed with R26R-Tdtomato mice to generate LepR-Cre; R26R-Tdtomato mice, which enabled fate-mapping of NPs from embryo stage to late adult. LMNA G609G/G609G mice was used to determine the effect of premature-aging induced IDD on LepR NPs. X-ray imaging was used to measure lumber disc height of mice. Results: Here, we provide the first evidence that the leptin receptor (LepR) is preferentially expressed in NCs at embryonic stages and notochord-derived cells in the postnatal IVD. By using R26R-Tdtomato fluorescent reporter mice, we systematically analysed the specificity of activity and targeting efficiency of leptin receptor-Cre (LepR-Cre) in IVD tissues from the embryonic stage E15.5 to 6-month-old LepR-Cre; Rosa26-Tdtomato (R26R-Tdtomato) mice. Specifically, LepR-Cre targets a distinct subpopulation of notochord-derived cells closely associated with disc homoeostasis. The percentage of LepR-expressing NP cells markedly decreases in the postnatal mouse IVD and, more importantly, in the human IVD with the progression of IDD. Moreover, both spine instability-induced and premature ageing-induced IDD mouse models display the phenotype of IDD with decreased percentage of LepR-expressing NP cells. These findings uncover a potential role of LepR-expressing notochord-derived cells in disc homoeostasis and open the gate for therapeutically targeting the NP cell subpopulation. Conclusion: In conclusion, our data prove LepR-Cre mice useful for mapping the fate of specific subpopulations of IVD cells and uncovering the underlying mechanisms of IDD. The translational potential of this article: The translation potential of article is that we first identified LepR as a candidate marker of subpopulation of nucleus pulposus (NP) cells and provided LepR as a potential target for the treatment of intervertebral disc degeneration (IDD), which have certain profound significance.