Type IV collagen is the principal component of glomerular basement membrane and messangial matrix. Studies have shown increased levels of urinary type IV collagen (uIV) in diabetic patients compared to healthy controls. The concentration of uIV increases gradually as diabetic nephropathy progresses.
AIM AND METHOD: This study was carried out to determine whether urinary type IV collagen (uIV) can serve as an indicator of diabetic nephropathy. Using a sandwich enzyme immunoassay technique, uIV excretion was determined in 30 type 2 diabetic patients with normoalbuminuria and 20 patients with microalbuminuria.
RESULTS: uIV excretion was significantly increased in type 2 diabetics, in both normoalbuminuric and microalbuminuric patients, compared with healthy controls. The increase in urinary type IV collagen was well correlated with the amount of urinary albumin but not with HbA1C.
CONCLUSION: Our findings that uIV is higher in those with microalbuminuria and correlates with albuminuria, support uIV as an indicator of diabetic nephropathy. Whether the increased uIV excretion would predict the impending renal failure needs further confirmation.
This study aimed at examining the biophysical characteristics of human derived keratinocytes (HaCaT) cultured on cholesteryl ester liquid crystals (CELC). CELC was previously shown to improve sensitivity in sensing cell contractions. Characteristics of the cell integrin expressions and presence of extracellular matrix (ECM) proteins on the liquid crystals were interrogated using various immunocytochemical techniques. The investigation was followed by characterization of the chemical properties of the liquid crystals (LC) after immersion in cell culture media using Fourier transform infrared spectroscopy (FTIR). The surface morphology of cells adhered to the LC was studied using atomic force microscopy (AFM). Consistent with the expressions of the integrins α2, α3 and β1, extracellular matrix proteins (laminin, collagen type IV and fibronectin) were found secreted by the HaCaT onto CELC and these proteins were also secreted by cells cultured on the glass substrates. FTIR analysis of the LC revealed the existence of spectrum assigned to cholesterol and ester moieties that are essential compounds for the metabolizing activities of keratinocytes. The immunostainings indicated that cell adhesion on the LC is mediated by self-secreted ECM proteins. As revealed by the AFM imaging, the constraint in cell membrane spread on the LC leads to the increase in cell surface roughness and thickness of cell membrane. The biophysical expressions of cells on biocompatible CELC suggested that CELC could be a new class of biological relevant material.
The aim of the present study was to evaluate the effects of air-liquid interface on the differentiation potential of human amnion epithelial cells (HAECs) to skin-like substitute in organotypic culture.
Bacterial adherence to connective tissue, especially to collagen has been vastly known for their invasive and infectious activities. However, the ability to exploit the unique and specific interactions between bacteria and collagen as a novel approach in detection of placental collagen has never been explored. This study aimed to determine bacteria with binding specificity to placental collagen (Type IV) derived from human and sheep. In order to do this, total bacteria from small intestines of pig and cow were isolated and their ability to bind to Type IV placental collagen (human and sheep) was determined. Interestingly, three bacterial samples; P5, P9 (pig small intestine origin) and B7 (cow small intestine origin) were found to be able to bind strongly to the placental collagen. The bacterial binding to human placental collagen was however, diminished after the bacteria were treated with trypsin, proteinase K (for removal of surface protein) and guanidine hydrochloride (for S-layer removal), suggesting that the interaction of these bacteria to placental collagen was promoted by protein(s) present at the bacterial surface. In addition, significant reduction of placental collagen-binding ability of the bacteria pre-incubated with soluble human placental collagen showed that there is a specific interaction between the bacteria and collagen. P5, P9 and B7 bacteria were found to share 95-97% 16S rRNA sequence similarity to Enterococcus faecalis ZL, Enterococcus hirae ss33b and Enterococcus faecium M3-1, respectively. The results presented here may facilitate future studies in identifying bacterial surface protein(s) responsible for the specific binding of bacteria to collagen and opens new opportunity to utilize the protein(s) for the detection of placental collagen in nutraceutical and food supplements.