Alicja Karwowska

Human cathepsin D.

A literature survey was performed of human cathepsin D gene, cathepsin D biosynthesis, posttranslatory modifications, transport within the cell, substrate specificity and catalytic effect. Methods used to determine the activity and level of this proteinase as well as its role in the biochemistry and pathobiochemistry of cells, tissues and organs were considered.

Thiocyanate concentration in saliva of cystic fibrosis patients.

Thiocyanates (SCN-) are ubiquitous in nature. There are indispensable part of host defense system that act as a substrate for lactoperoxidase (LPO). In our study we present initial data on SCN- concentration in saliva of CF patients in comparison to healthy non-smokers and healthy smokers. 5 ml of saliva was collected from each subject to a sterile tube and thiocyanate concentration was measured in each sample. The results of the measurements are presented on Fig. 1. Mean concentration of SCN- in saliva of CF patients was 0.031 +/- 0.0052 g/l, in healthy non-smokers 0.039 +/- 0.0048 g/l and in healthy smokers 0.048 +/- 0.0161 g/l. The differences between each group were statistically significant. Studies on larger group of patients and probably on different material (BALF or induced sputum) should present interesting data complementing the in vitro studies.

Fetal membranes as a source of stem cells

In recent years, a constant growth of knowledge and clinical applications of stem cells have been observed. Mesenchymal stromal cells, also described as mesenchymal stem cells (MSCs) represent a particular cell type for research and therapy because of their ability to differentiate into mesodermal lineage cells. The most investigated source of MSCs is bone marrow (BM). Yet, collection of BM is an invasive procedure associated with significant discomfort to the patient. The procedure results in a relatively low number of these cells, which can decrease with donors age. Therefore, it seems to be very important to find other sources of mesenchymal stem cells nowadays. A human placenta, which is routinely discarded postpartum, in spite of its natural aging process, is still a rich source of stem cells capable to proliferate and in vitro differentiate in many directions. Besides homing and differentiation in the area of injury, MSCs there elicit strong paracrine effects stimulating the processes of repair. In this review, we focus on the biology, characteristics and potential clinical applications of cells derived from human fetal membranes: amnion and chorion.

Quantitative determination and localization of cathepsin D and its inhibitors

A literature survey was performed of the methods of quantitative assessment of the activity and concentration of cathepsin D and its inhibitors. Usefulness of non-modified and modified proteins and synthetic peptides as measurement substrates was evaluated. The survey includes also chemical and immunochemical methods used to determine the distribution of cathepsin D and its inhibitors in cells and tissues.

Role of cathepsin A and cathepsin C in the regulation of glycosidase activity.

Increased tissue activity of cathepsin A and cathepsin C can be observed in many pathological conditions. It is associated with an enhanced degradation of glycosaminoglycans, proteoglycans, and glycoproteins, and results in their decreased tissue content. Cathepsin C releases the glycosidases from complexes formed with cathepsin A, and reinstates their activity. In this review a current state of knowledge is presented concerning the regulation of selected glycosidases activity by cathepsin A (EC 3.4.16.1) and C (EC 3.4.14.1).

Effect of heavy metal cations on the activity of cathepsin D (in vitro study).

We studied the effect of heavy metal cations: Fe 2+, Cu2+, Zn2+, Cd2+, Hg2+, Pb2+ on the activity of cathepsin D in human aorta homogenate and blood serum. The concentration of cations was 1 mmol/l. Hemoglobin was the cathepsin D substrate. The activity of cathepsin D was determined at pH 3.5. Only Hg2+ cations inhibit the activity of cathepsin D. Cations Hg2+ damage lysosomes and release cathepsin D from these organelles.