Ari Rinne

Primary structure of bovine cathepsin S. Comparison to cathepsins L, H, B and papain.

The primary structure of bovine cathepsin S was determined by combining results of protein and peptide sequencing with the sequence deduced from nucleic acid sequencing. Using polymerase chain reaction (PCR) technology, cDNA clones commencing at amino acid 22 of the mature enzyme and continuing through the 3′ untranslated region of bovine cathepsin S mRNA were isolated and sequenced. The open reading frame in these overlapping clones correctly predicts the determined amino acid sequence of 13 tryptic peptides derived from purified bovine spleen cathepsin S. The deduced amino acid sequence shows that mature bovine cathepsin S consists of 217 amino acids corresponding to a molecular weight of 23.7 kDa. Cathepsin S belongs to the papain superfamily of lysosomal cysteine proteinases and shares 41% identity with papain. Amino acid sequence identities of bovine cathepsin S to human cathepsins L, H, and B are 56%, 47% and 31% respectively.

Cystatin a-like immunoreactivity is widely distributed in human brain and accumulates in neuritic plaques of alzheimer disease subjects

The cellular localization of cystatin A, an endogenously occurring inhibitor of lysosomal thiol proteases (cathepsins B, H, L and S), was studied immunohistochemically in human postmortem brain using the peroxidase-antiperoxidase method. Both polyclonal and monoclonal antibodies to cystatin A were employed. Western blot analysis revealed one molecular form of the inhibitor in human brain extracts. Its molecular weight was about 13,000. Immunostaining appeared in a sizeable population of neurons and a few cells surrounding cerebral blood vessels (pericytes). In Alzheimer disease subjects cystatin A was found in many neuritic plaques. Possible functional consequences with regard to a role of cystatin A in the inhibition of the Alzheimer amyloid precursor protein (APP)-clipping enzyme, cathepsin B, are discussed.

Concentrations of lysosomal cysteine proteases are decreased in renal cell carcinoma compared with normal kidney

Renal cell carcinoma contains significantly lower concentrations of the lysosomal cysteine proteases, cathepsins B, C, H, L and S, than does normal kidney, as shown by several methods, such as activity determination, enzyme-linked immunosorbent assay, immunoblotting and immunohistochemistry. The same low levels of enzyme activity and concentration have been determined in renal cell carcinoma metastases in the lung. Our results on the decreased concentration of cysteine peptidases at the protein level would seem to conflict with earlier results on an increased concentration of the cathepsin L mRNA in renal cell carcinoma.

IMMUNOLOCALIZATION OF CYSTATIN A IN NEOPLASTIC, VIRUS AND INFLAMMATORY LESIONS OF THE UTERINE CERVIX

Cystatin A was immunohistochemically demonstrated in the normal squamous epithelium of the uterine cervix, particularly in the parabasal and superficial cell layers whereas it was absent or scanty in the basal cells and in areas with parakeratosis. Cystatin A was also found in neoplastic lesions (dysplasia, carcinoma in situ and squamous cell carcinoma), but less abundant than in normal squamous epithelium. The immunoreaction in intraepithelial neoplasia was closely related to the degree of morphological maturation of the squamous cells with more abundant cystatin A in low grade dysplasia and less in high grade dysplasia and carcinoma in situ. In squamous cell carcinoma, cystatin A was often abundant in highly differentiated areas and almost absent in poorly differentiated ones. Cystatin A was found in the squamous epithelium in herpes and in condylomatous lesions. It was also found in the cytoplasm of neutrophils, but not in lymphocytes and plasma cells. In unspecific cervicitis, cystatin A was found extracytoplasmatically as small vesicles in the epithelial-stromal junction. The implications of cystatin A in neoplastic, virus, and inflammatory processes are discussed.

Biological and prognostic role of acid cysteine proteinase inhibitor (ACPI, cystatin A) in non-small-cell lung cancer

Background: Acid cysteine protease inhibitor (ACPI) is an intracellular protein, often linked to neoplastic changes in epithelium and thought to have an inhibitory role in malignant transformation. Aim: To analyse the expression and prognostic role of ACPI in non-small-cell lung cancer (NSCLC). Method: Histological samples from 199 patients with resected NSCLC were stained immunohistochemically for the expression of ACPI in normal and preneoplastic bronchial epithelium, and in various types of lung carcinomas. Results: A normal bronchial epithelium showed positive staining for ACPI in the basal cells, whereas the upper two-thirds of the dysplastic epithelium was ACPI positive. High staining for ACPI was found in 74% (91/123) of squamous-cell carcinomas, whereas 16% (8/49) of adenocarcinomas and 30% of (8/27) large-cell carcinomas showed the high expression of ACPI (p<0.001). Among squamous-cell carcinomas, low expression of ACPI was correlated with poor tumour differentiation (p = 0.032). In the whole tissue, reduced expression of ACPI was associated with tumour recurrence (p = 0.024). In overall survival (OS) and disease-free survival (DFS) analyses, the histological type of the tumour (both p<0.001) and stage of the tumour (p = 0.001, p = 0.013, respectively) were related to patient outcome. Low expression of ACPI in tumour cells was associated with poor OS and DFS (p<0.041, p = 0.004, respectively). In multivariate analysis, ACPI did not retain its prognostic value, whereas the traditional factors were the most important prognostic factors. Conclusions: ACPI expression is linked with the malignant transformation of the bronchial epithelium and predicts a risk of tumour recurrence as well as poor rate of survival for the patients. However, ACPI does not have any independent prognostic value in NSCLC.

Cystatin A and B in the development of human squamous epithelia.

The expression of cystatin A (Acid cysteine proteinase inhibitor) and B (Neutral cysteine proteinase inhibitor) during human embryogenesis was studied immunohistochemically by using the PAP-complex method. Both inhibitors were visible first in the developing mucosal tissue at the age of about 9 weeks. In the fetal epidermis (periderm), cystatin B was demonstrated at the age of 11 weeks and cystatin A at 12 weeks. In these young fetuses, the staining was visible in the basal cells, whereas in fetuses older than 17 weeks the staining of both inhibitors diminished in the basal cells. In the skin of 17 to 25 weeks old fetuses, the epidermal staining of cystatin B become weaker than that of cystatin A, and at the age of about 26 weeks, cystatin B disappeared totally. At this stage, cystatin A was localized in the cytoplasm of the middle to upper cell layers of the epidermis. In the squamous epithelia of the mucosal tissues, the staining of the both inhibitors reached their maximal intensity when the fetuses were about 16 weeks old. At the mature fetuses, infants as well as adults, both cystatin A and B seemed to be present in wet squamous epithelia while in the epidermis only cystatin A was expressed.

Epidermal SH-protease inhibitor (ACPI, cystatin A) in cancer. A short historical review.

This review article will re-report the findings from 30 years ago concerning the implications of the acid cystein proteinase inhibitor (ACPI) to the field of cancer research. The original article, published in 1980, has erroneously been omitted from electronic article databases. The findings reported in the original article suggest that some anaplastic lung cancers should be classified as epidermal. In this article we also consider the yet unknown physiological function of ACPI. Furthermore, we will address the simplification of the nomenclature of ACPI and related molecules.

The 43 kDa papain inhibitor in normal and diseased skin.

The presence of 43 kDa papain inhibitor in 43 different skin diseases was immunohistochemically studied by using both poly‐and monoclonal antibodies. Psoriasis and various eczematoid reactions as well as viral infections showed the most pronounced staining in the squamous cells of the epidermis. The antigen was also present in benign tumours or precancerous lesions which showed keratinization. Cells of poorly differentiated squamous cell carcinomas, basal cell carcinomas and melanocytic tumours were negative. The antigen seems to be related to disturbed keratinization and benign proliferation in non‐neoplastic derma‐toses and it is also present in differentiating squamous neoplasms.

The 43 kDa papain-inhibiting protein in psoriatic epidermis is identical to squamous cell carcinoma antigen (SCC-antigen).

The scales of patients suffering psoriasis as a rich source of cysteine proteinase inhibitors. The major inhibitor in psoriatic epidermis is cystatin A (1), which also is highly expressed in normal epidermis (2). In addition to cystatin A (12.6 kDa), psoriatic epidermis contains a high amount of another papain-inhibiting protein (43 kDa) which can easily be separated from cystatin A by gel chromatography and then purified by ion exchange chromatography (3). By isoelectric focusing, three major activity peaks with pI’s of 7.3, 6.9 and 6.5 are separated. By immunohistochemical techniques, using antibodies against the isoelectric variant pi 6.9, the inhibitor is located in the cytoplasm of suprabasal layers of the psoriatic epidermis. In the immature psoriatic stratum corneum the staining for the 43 kDa inhibitor is very variable and uneven: sometimes a strong uniform staining is seen and sometimes the stained and unstained areas vary both vertically and horizontally in a single section (3). In addition to psoriasis, the expression of the inhibitor is elevated in several skin disorders where proliferation of the epidermal cell is accelerated (4). In normal epidermis the inhibitor is seen only in granular layer and in stratum corneum. The inhibitor seems to be a constant property of various squamous epithelia of skin, mouth, oesophagus, uterine portio and thymus and it is also expressed in squamous cell carcinomas and in the so-called basal cells of bronchial epithelium (5).