02 Microglobulin

Cadmium is effectively accumulated in the kidneys. When the cadmium concentration exceeds 200 gg/g in the kidney cortex, tubular damage will occur in 10% of the population, and proteins begin to leak into urine (proteinuria). When the concentration of cadmium in the kidney cortex exceeds 300 pg/g, the effect is seen in 50% of the exposed population. Typically, excretion of low-molecular weight proteins, such as beta-microglobulin, is increased, due to dysfunction of proximal tubular cells of the kidney. The existence of albumin or other high-molecular weight proteins in the urine indicates that a glomerular injury has also taken place. The excretion of protein-bound cadmium will also be increased. 

Nagaya T, Ishikawa N, Hata H. 1989b. Urinary total protein and Pj-microglobulin in workers exposed to trichloroethylene. Environ Res 50 86-92. 

Monitoring of Cd exposure can take place by the determination of Cd in whole blood (reflects recent exposure) or urine (reflects body burden) by GF-AAS. Early effects can be monitored by the determination of a tubular protein (e.g. 132-microglobulin, retinol binding protein, a2-microglobulin) or the activity of an enzyme (e.g. N-acetyl 3-D-glucosaminidase) in urine. 

P2-microglobulin concentration have been correlated with survival. The International Index is a predictive model for aggressive NHL to be treated with doxorubicin-containing chemotherapy regimens.11 This index is used as a tool for selecting therapy for patients who may warrant a more intense treatment regimen based on known poor prognostic factors. 

P2 Microglobulin A low-molecular-weight protein that may be elevated in multiple myeloma. 

Rat (Wistar) 2-4 mo ad lib (W) Renal 81 F 320 F (tubular dysfunction as indicated by 2-3-fold increase in urinary excretion of B2-microglobulin) Vyskocil et al. 1995 PbAc... 

Figure 9.7 Iron transport by hepatocytes. Known proteins involved in iron transport across the plasma membrane of hapatocytes are represented. LMW = low molecular weight Trf = transferrin Trf-R = transferrin receptor HFE = hamochromatosis gene product 132m = 62-microglobulin 02-= superoxide OH- = hydroxyl radical FR = ferritin receptor SFT = stimulator of iron transport.

Although many animal models for iron overload exist, some mimicking certain aspects of HH, the 32-microglobulin knockout mouse is of special interest as it revealed for the first time crucial aspects of the pathogenesis of human HH in an animal model, and also because it underlines the important links between iron metabolism and the immune system. Hepatic iron overload in 32-microglobulin ( 32m)-deficient mice appeared to be similar to that found in HH, with pathological iron depositions occurring predominantly in liver parenchymal cells (de Sousa et ah,... 

Figure 4. AFM micrograph of a saturated monolayer of antibodies against p2-microglobulin measured in phosphate buffered saline (PBS) solution using tapping mode. The dark window shows the underlying polystyrene surface obtained by wipping off the antibodies.

Table 2. Responses of a grating coupler sensor coated with multilayers of monoclonal antibodies to the respective analytes. The response values are related to that of an adsorbed antibody monolayer (B2M p2-microglobulin, HCG human choriogonadotropin, HRP horseradish peroxidase.

Brynda E., Elouska M., Brandenburg A., Wikerstal A., Skvor J., The detection of human P2-microglobulin by grating coupler immunosensor with three-dimensional antibody networks, Biosens. Bioelectron. 1999 14 363-368. 

Bergen M, Chen R, Gonzalez R (2003) Efficacy and safety of HLA-B7/beta-2 microglobulin plasmid DNA/lipid complex (Allovectin-7) in patients with metastatic melanoma. Expert Opin Biol Ther 3 377-384... 

Hochman, J.H., Shimizu, Y., PeMars, R., and Edidin, M. (1988) Specific associations of fluorescent B-2 microglobulin with cell surfaces./. Immunol. 140, 2322-2329. 

The concept is demonstrated for a simultaneous immunoassay of (32-microglobulin, IgG, bovine serum albumin, and C-reactive protein in connection with ZnS, CdS, PbS, and CuS colloidal crystals, respectively (Fig. 14.6). These nanocrystal labels exhibit similar sensitivity. Such electrochemical coding could be readily multiplexed and scaled up in multiwell microtiter plates to allow simultaneous parallel detection of numerous proteins or samples and is expected to open new opportunities for protein diagnostics and biosecurity. 

FIGURE 14.6 Typical stripping voltammograms for (a) nanocrystal-labeled antibodies and (b-f) magnetic bead-Ab-Ag-Ab-nanocrystal complexes, (b) Response for a solution containing dissolved ZnS anti-/32-microglobulin, PbS-anti-BSA, and CdS-anti-IgG conjugates (reproduced from [29] with permission). 

P2-Microglobulin 0.002 11.8 Associated with human leukocyte antigen... 

AP and tau, 6-2 microglobulin Immunoglobulin light chain Serum amyloid A (SAA) Transthyretin (TTR) Apolipoprotein A-l Cystatin A Gelsolin... 

Ivanova, M. I., Sawaya, M. R., Gingery, M., Attinger, A., and Eisenberg, D. (2004). An amyloid-forming segment of //2-microglobulin suggests a molecular model for the fibril. Proc. Natl. Acad. Sci. USA 101, 10584-10589. 

Hirakura, Y., and Kagan, B. L. (2001). Pore formation by beta-2-microglobulin A mechanism for the pathogenesis of dialysis associated amyloidosis. Amyloid 8, 94-100. 

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