Nori Human Myonectin ELISA Kit Summary

Alternative names for myonectin: CTRP15, erythroferrone, ERFE

Standard Curve

Kit Components
1. Pre-coated 96-well Microplate
2. Biotinylated Detection Antibody
3. Streptavidin-HRP Conjugate
4. Lyophilized Standards
5. TMB One-Step Substrate
6. Stop Solution
7. 20 x PBS
8. Assay Buffer

Other Materials Required but not Provided:
1. Microplate Reader capable of measuring absorption at 450 nm
2. Log-log graph paper or computer and software for ELISA data analysis
3. Precision pipettes (1-1000 µl)
4. Multi-channel pipettes (300 µl)
5. Distilled or deionized water

Protocol Outline
1. Prepare all reagents, samples and standards as instructed in the datasheet.
2. Add 100 µl of Standard or samples to each well and incubate 1 h at RT.
3. Add 100 µl of Working Detection Antibody to each well and incubate 1 h at RT.
4. Add 100 µl of Working Streptavidin-HRP to each well and incubate 20 min at RT.
5. Add 100 µl of Substrate to each well and incubate 5-30 min at RT.
6. Add 50 µl of Stop Solution to each well and read at 450 nm immediately.

Background: 

Myonectin (CTRP15) is a novel nutrient-responsive myokine secreted by skeletal muscle to regulate whole-body fatty acid metabolism.[1] Myonectin is a member of the C1q/TNF-related protein (CTRP) family and was shown to be identical to erythroferrone, a hormone produced in erythroblasts that is involved in iron metabolism.^[2] This important, biologically active molecule is released into circulation by muscular contraction, and is roughly equivalent to insulin in its potency. Myonectin responds to changes in cellular energy state resulting from glucose or fatty acid fluxes. Many metabolically relevant secreted proteins (e.g. adiponectin, leptin, resistin, and RBP) and the signaling pathways they regulate in tissues are known to be dysregulated in the condition of obesity. The reduction in expression and circulating levels of myonectin in the obese state may represent yet another component of the complex metabolic circuitry dysregulated by excess caloric intake. Although exercise has long been known to have profound positive impacts on systemic insulin sensitivity and energy balance, the underlying mechanisms remain incompletely understood. That voluntary exercise dramatically increases the expression and circulating levels of myonectin to promote fatty acid uptake into cells may underlie one of the beneficial effects of physical exercise.”^[1] Serum CTRP15 concentrations were associated with the key components of MetS and insulin resistance and acutely increase in response to EPO in the setting of normal or impaired kidney function.[3][4] Myonectin links skeletal muscle to lipid homeostasis in liver and adipose tissue in response to alterations in energy state, revealing a novel myonectin-mediated metabolic circuit.[5] CTRP5 is a novel pro-atherogenic cytokine and promotes transcytosis and oxidation of LDL in endothelial cells via up-regulation of 12/15-LOX.[6] CTRP5 has a role in extracellular deposit formation in late-onset retinal degeneration.[7]

References

1. Marcus M. S, et al. Biol. Chem. 287, NO. 15, pp. 11968–11980.
2. Kautz L, et al. (2014). Nat Genet. 46 (7): 678–84.
3. Mi, Q. et al. (2019) Diabetes Metab. Res. Rev. 35 (1), e3085.

4.      Hanudel MR, et al. (2018) Haematologica 103 (4), e141-e142.

5. Seldin MM, et al. (2012) J. Biol. Chem. 287 (15), 11968-11980.
6. Li C et al. (2018) Atherosclerosis 278, 197-209.

7.      Hayward C, et al. (2003) Hum. Mol. Genet. 12 (20), 2657-2667.