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.

Atlantic salmon (Salmo salar L.) skin contains a novel kininogen and another cysteine proteinase inhibitor

We describe the purification and characterization of two novel cysteine proteinase inhibitors found in Atlantic salmon skin. One of these, salmon kininogen, has a molecular mass of 52 kDa as determined by matrix-assisted laser desorption/ionization time-of-flight MS, is multiply charged with pI values of 4.0, 4.2 and 4.6 and shows homology to kininogens including the bradykinin motif. The other, salarin, has a molecular weight of 43 kDa, a pI of 5.1 and shows weak homology to cysteine proteinases. Both proteins are N- and O-glycosylated and inhibit papain and ficin but not trypsin.

Rhabdovirus-induced apoptosis in a fish cell line is inhibited by a human endogenous acid cysteine proteinase inhibitor

To determine the mechanisms of cell death in rhabdovirus-infected cells, we studied the infection of the epithelial papilloma of carp cell line with spring viremia of carp virus. Studies using electron microscopy, confocal microscopy, and agarose gel electrophoresis revealed changes in cell morphology and DNA fragmentation indicative of apoptosis. The virus-induced apoptosis was inhibited in cells treated with a human endogenous acid cysteine proteinase inhibitor.

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.

The possible place of cathepsins and cystatins in the puzzle of Alzheimer disease: a review

Lysosomal proteinases (cathepsins) and their endogenous inhibitors (cystatins) have been found to be closely associated with senile plaques, cerebrovascular amyloid deposits, and neurofibrillary tangles in Alzheimer disease (AD). Further, profound changes in the lysosomal system seem to be an early event in "at-risk" neurons of AD brains. There is an ongoing controversy as to whether lysosome-associated proteolytic mechanisms are causally related to the development and/or further progression of the disease. The present article deals with some arguments "pro" and "contra" an involvement of the endosomal/lysosomal pathway in amyloidogenesis as a cardinal process in AD. Other putative targets of acidic proteinases and their natural inhibitors in the pathogenesis of AD (such as formation of neurofibrillary tangles and regulation of apolipoprotein E) are also discussed.

Accessory cells in physiological lymphoid tissue from the intestine: an immunohistochemical study

We report a study of the organization of accessory cell populations, in normal mucosal lymphoid tissue from small intestine (8 cases), large intestine (6) and appendix (9) using a panel of monoclonal antibodies and polyclonal antisera in paraffin-embedded tissue. Two populations were identified in dome areas, one positive for acid cysteine proteinase inhibitor and HLA class II (WR18) only and the second positive for S-100 protein, CD68, and WR18 and negative for acid cysteine proteinase inhibitor and factor XIIIa. Superficial colonic mucosal and small intestinal villous tip macrophages stained positively with CD68 and WR18 only, while deeper cryptal and submucosal populations exhibited additional positivity for factor XIIIa, but both populations were negative for acid cysteine proteinase inhibitor and S-100 protein. Germinal centre macrophages were positive for CD68, WR18 and acid cysteine proteinase inhibitor and negative for factor XIIIa, and S-100 protein. T zone dendritic cells included a population which stained positively for S-100 protien, WR18 and were negative for factor XIIIa, CD68 and acid cysteine proteinase inhibitor, an immunophenotype typical of interdigitating dendritic reticulum cells. This distribution of phenotypically identifiable accessory cell subpopulations was apparent at all three sites examined. We suggest that the specialized subpopulations of dendritic cells staining for S-100 protein and for acid cysteine proteinase inhibitor which are restricted to the dome areas, may have a potential role in the transfer of antigen across the epithelium to the germinal centres, while factor XIIIa appears to identify a tissue macrophage population with a potential role in stromal modulation distant from direct antigen challenge.

Expression of acid cysteine proteinase inhibitor (ACPI) in the normal human prostate, benign prostatic hyperplasia and adenocarcinoma

Acid cysteine proteinase inhibitor (ACPI or cystatin A) is a protein (12 kDa) which inhibits the action of several cysteine proteinases, e.g. cathepsins B, H, L and S. In this study the cellular location of ACPI has been immunohistochemically investigated in the normal human prostate, in benign prostatic hyperplasia (BPH) and in adenocarcinoma. ACPI was found in the basal epithelial cells of the normal prostate. The secretory epithelial cells did not express ACPI. In the hyperplastic prostate, the expression of ACPI was decreased and it was also expressed more focally in the basal cells. Hyperplastic basal cells also expressed ACPI. In prostatic adenocarcinoma, no ACPI expression was found. The absence of ACPI expression was obvious and if the sections contained both benign and malignant cells, only the benign glandular structures always expressed ACPI. The results suggest that expression of ACPI might be related to prostatic epithelial cell proliferation and differentiation. Possibly the detection of ACPI in tissue sections might be helpful in identifying prostatic adenocarcinoma, especially in cases with small carcinomatous foci.

Immunolocalization of cystatin A in condylomatous and dysplastic lesions of the human uterine cervix: correlation with the presence and type of human papillomavirus infection

Cystatin A is the major cysteine proteinase inhibitor in human squamous epithelia. We investigated the occurrence of cystatin A in normal, condylomatous, and dysplastic lesions of the cervix with or without human papillomavirus (HPV) infection. Cystatin A was detected by immunohistochemistry and HPV infection by DNA hybridization techniques. In the normal uterine cervix, cystatin A was seen throughout the epithelium, except in the basal and parabasal cell layers. In condylomatous lesions, the staining intensity was similar to that in normal epithelium. In low-grade cervical intraepithelial neoplasias (CINs), reduced staining was seen in the lower third of the epithelium; in high-grade CINs, a reduction in staining intensity was also seen in the middle and upper thirds. Cystatin A staining in epithelia and nuclei was negative in highly cellular and poorly differentiated CIN III. The cytoplasmic staining of cystatin A did not correlate with presence or type of HPV DNA. In the high-grade CINs infected with HPV types 16 and 18, however, cystatin A staining was more often confined to the nuclear compartment.

Acid cysteine proteinase inhibitor in cutaneous lymphocytic infiltrates

Acid cysteine proteinase inhibitor (ACPI, cystatin A) is normally present in squamous epithelium and dendritic cells of lymphoid follicles. Its expression is altered both in proliferative and malignant squamous epithelium and in neoplastic lymphoid follicles. The expression of ACPI in the lymphoid infiltrates of cutaneous psuedolymphomas and B-cell lymphomas was studied. Eighteen pseudolymphomas from 15 patients were divided into three groups according to the proportion of B and T lymphocytes. The B-cell-type lesions with well-developed follicles and germinal centers showed a pronounced ACPI expression in dendritic cells. Varying amounts of ACPI-positive cells were present in the mixed B- and T-cell-type and also in the T-cell-type lesions. The labeled cell population was distinct from the factor XIIIa-positive dermal dendrocytes, S-100-positive histiocytes, and HAM 56-positive histiocytes. Malignant lymphomas contained a few haphazardly arranged ACPI-positive cells with short dendrites and granular cytoplasm. It was concluded that follicular dendritic cells can be reliably labeled with ACPI antiserum in cutaneous pseudolymphomas. The structure and distribution of ACPI-containing cells in malignant cutaneous B-cell lymphomas is altered when compared with pseudolymphomas.

Identification of acid cysteine proteinase inhibitor (cystatin A) in the human thymus

BACKGROUND

Acid cysteine proteinase inhibitor (ACPI, also called cystatin A) is a protein that is present in the epithelial cells of the skin and in the dendritic reticulum cells of lymphoid tissues. In this study the presence and cellular localization of ACPI in the thymus was investigated.

METHODS

The cellular and topographical location of ACPI was immunohistochemically demonstrated in the normal thymus of man.

RESULTS

ACPI was found in the cells of the Hassall's corpuscles and in many medullary cells. Most of these cells were epithelial cells, as shown by the results of immunohistochemical cytokeratin and epithelial membrane antigen stainings. Also, some individual cytokeratin negative but S-100 positive medullary reticular dendritic cells were stained with ACPI.

CONCLUSIONS

The finding that ACPI is constantly present in the thymus at restricted and specific cellular locations leads to the suggestion that protease inhibitors may play a role in specific thymic functions.

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.

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.

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.

Antigenic expression of cathepsin B in aged human brain

The lysosomal thiol proteinase, cathepsin B, has been localized in different regions of aged human brain by use of the peroxidase-antiperoxidase technique. Cathepsin B-immunoreactive material was detected in multiple neurons of human hippocampus, neocortical area A 10, prefrontal gyrus and nuc. basalis of Meynert as well as in single white matter astrocytes. In brains of Alzheimer disease-affected subjects cathepsin B was revealed in neuritic plaques too. Possible functional consequences with regard to normal aging, neuropeptide metabolism and pathological changes are discussed.

Crying, feeding and sleeping patterns in 1 to 12-month-old infants

The crying, feeding and sleeping patterns of 270 infants 0-12 months old were studied using a 24-hour schedule included in a questionnaire given to mothers visiting four well-baby clinics in Finland in 1987-88. Of these infants 78 were under 3, 84 were 3-5, 65 were 6-8 and 43 were over 9 months old. The results showed that the infants less than 3 months old slept on average 15.2 hours per day, whereas those over 9 months slept 13.4 hours. The sleeping periods were longer at night. Continuous night-time sleep for at least 6 hours was noted in 35% of the infants under 3 months old and the proportion increased to 72% by the age of 9-12 months. The youngest infants were fed on average 6-7 times per day at 2- to 3-hour intervals in the daytime and at 4- to 6-hour intervals at night. The number of feedings decreased slightly with age. The average total crying time decreased from 1.6 hours per day for the youngest group to 1.1 hours for the 9-12 months old. At the time of the study, 23 mothers felt the need for help because of excessive crying or night waking. The help needed ranged from information about colic and child care, help with housework or the baby and encouragement. Of the mothers who needed help, a significantly higher proportion had a first-born baby compared with those not in need of help. There were also significant differences in the mothers' perception of the cry and feelings towards it.

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.

Cathepsin S from bovine spleen. Purification, distribution, intracellular localization and action on proteins

Cathepsin S was detected in bovine kidney, spleen, lymph nodes and lung by immunochemical methods. The immunostaining of cathepsin S in kidney was concentrated to the cells of the proximal tubule, where the enzyme was present in cytoplasmic granules. The purification method for cathepsin S from bovine spleen involved (NH4)2SO4 fractionation, chromatography on CM-Sephadex C-50, gel filtration on Sephacryl S-200 and chromatofocusing (pH 8.0-6.0). The enzyme was partially destroyed by autolysis of the homogenate at pH 4.2. The isoelectric point of cathepsin S was 7.0. Cathepsin S was found to hydrolyse proteins at a similar rate to cathepsin L below pH 7.0. At pH values of 7.0-7.5 cathepsin S retained most of its activity, whereas cathepsin L was completely inactive.

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 dermatoses and it is also present in differentiating squamous neoplasms.

The 43 kDa inhibitor of human skin and other epithelia

We have used immunohistochemical and quantitative immunochemical techniques to study the tissue distribution of the 43 kDa papain inhibiting protein, originally isolated from psoriatic scale. High amounts of the inhibitor were found in the epidermis only in several skin diseases where the epidermal cell proliferation was increased (psoriasis, various eczemas). The inhibitor was also found in the basal cells of the bronchial epithelium and in the squamous epithelia of mouth and oesophagus, and the Hassal's corpuscles of the thymus. Sera of patients suffering from several skin diseases did not contain the inhibitor, but antibodies against it were found in the sera of two patients suffering from leg ulceration. The inhibitor was immunologically unrelated to filaggrin, involucrin, or keratins.

Human cystatins in normal and diseased tissues--a review

Immunohistochemica and quantitative immunochemical methods were used to demonstrate the presence of two cysteine proteinase inhibitors, cystatins A and B, in normal and diseased tissues. Cystatin A is expressed in squamous epithelia, neutrophil granulocytes, and dendritic reticulum cells of the lymphatic tissues. Its concentration is increased in inflammatory skin diseases and decreases after the malignization of squamous epithelia. Cystatin B is seen in wet squamous epithelia, and in the cells of monocyte-macrophage series, where its concentration varies depending on the activation state of the cells. In the malignant keratinocytes cystatin B follows the behaviour of cystatin A.

Cathepsin D, B, and H in rat brain as demonstrated by immunohistochemistry

Monospecific antisera against cathepsins B, D, and H were used to immunolocalize these proteinases in neural structures of rat brain. Cathepsins B and D were found to be largely co-localized in nerve cells. Cathepsin H could not be identified by use of immunocytochemistry.

Damage to secondary lymphoid follicles in AIDS-related persistent generalized lymphadenopathy, as revealed by the behaviour of dendritic reticulum cells possessing immunoreactive acid cysteine-proteinase inhibitor

It has been shown previously that dendritic reticulum cells (DRC) in human secondary lymphoid follicles possess an immunoreactive acid cysteine-proteinase inhibitor (ACPI). In the present study, lymph nodes from 12 patients with AIDS-related persistent generalized lymphadenopathy (PGL) were investigated in order to detect whether or not any alterations occur in ACPI-immunoreactive DRC in this disorder. In the majority of PGL cases, profound alterations were found, the main characteristics of which were erosion, partial or total disruption of lymphoid follicles. However, similar though much less marked alterations were also found in some control cases. It is concluded that this type of follicular damage is a common and characteristic feature in PGL. It is not specific to PGL, however, but represents rather a special type of reaction in lymphatic tissue. The advantage of ACPI immunohistology for demonstrating the DRC pattern is that it can be performed on routinely fixed and paraffin-embedded tissues.

Centrorrhexis: a "new" reaction pattern of lymph nodes

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A 43-kDa papain inhibitor produced by a cultured human epidermal cell line

Epidermis-derived cells (NCTC 2544) were cultured and the proteins of the culture medium, as well as of the cells, were fractionated by gel-chromatography. The fractions were analyzed for their papain-inhibitory capacity and for the presence of so-called 43-kDa papain inhibitor. A papain inhibitor was identified with molecular weight and immunological characteristics similar to the original 43-kDa inhibitor that was isolated from psoriatic scales. The result proves that NCTC-2544 cells can produce the so-called psoriasis inhibitor under culture conditions.

Detection of low molecular weight cysteine proteinase inhibitors by time-resolved fluoroimmunoassay

A time-resolved fluoroimmunoassay was developed for the detection of 3 human low molecular weight cysteine proteinase inhibitors, ACPI (cystatin A), NCPI (cystatin B), and gamma-trace (cystatin C). Polystyrene tubes or polystyrene microtitration strips were used as solid phase. The rabbit anti-inhibitor immunoglobulins were used as the capture antibody, and, when labelled with europium, also as the detector antibody. The threshold sensitivity of the tests was 0.1 ng/ml for NCPI and 1 ng/ml for the others. All the 3 cysteine proteinase inhibitors, ACPI, NCPI, and gamma-trace, were detected in pooled serum samples of patients with kidney failure. gamma-Trace seemed to be quantitatively the major and ACPI the minor inhibitor. No other low molecular mass cysteine proteinase inhibitor was detected after isoelectric focusing of the 12 kDa area of gel filtered human serum.

Immunoelectron microscopical location of the acid cysteine proteinase inhibitor in the lymphatic tissue of the tonsils

Previous studies have shown the acid cysteine proteinase inhibitor (ACPI) to be a common characteristic of human squamous epithelial cells and dendritic reticulum cells (DRC) in lymphoid secondary follicles. In the present study, we used the PAP-preembedding technique for the immunoelectron microscopic identification of ACPI in DRC in palatine tonsillar tissue. ACPI appeared to be located in the cytoplasm of perikaryon and of dendritic processes of DRC on the membranes of the endoplasmic reticulum and the outer membrane of mitochondria. Further more, the tonofilaments and the desmosomal membranes exhibited a strong ACPI reactivity.

Natural cysteine proteinase inhibitors reduce lectin induced lymphocyte stimulation

Lymphocyte stimulation by lectins can be inhibited by several synthetic inhibitors of proteolytic enzymes, notably those of cysteine proteinases. The effects of naturally occurring enzyme inhibitors are less well known. The effect of the neutral low-molecular weight cysteine proteinase inhibitor (NCPI) recently purified from lymph nodes and spleen was therefore investigated. Cultured peripheral blood lymphocytes were stimulated by PHA or ConA in the presence or absence of NCPI and the incorporation of 3H-thymidine was measured. NCPI was found to inhibit these lymphocyte responses in these circumstances.

Atrial natriuretic polypeptides in the specific atrial granules of the rat heart: immunohistochemical and immunoelectron microscopical localization and radioimmunological quantification

Atria of several mammalian species contain atrial natriuretic polypeptides (ANP) with natriuretic, diuretic, and vasodilating activity. In the present studies ANP were localized and quantitated in different parts of the heart by immunocytochemical and radioimmunological methods. The concentration of immunoreactive ANP as determined by quantitative radioimmunoassay in rat heart atria was a follows (ng/mg, mean +/- SD, n = 5): right auricle (688 +/- 156), left auricle (556 +/- 156), right atrium (334 +/- 60), and left atrium (93 +/- 36). The staining intensities in immunohistochemical localizations were consistent with the quantitative data. The location of the peptides was sarcoplasmic and granular. The highest concentration of ANP was found in the perinuclear area of the atrial myocyte sarcoplasm, but some staining was also seen in the periphery of the cells. The indirect immunoelectron microscopical gold method showed that ANP are located in the specific atrial granules supporting previous findings.

Neuropeptides in macula utriculi and macula sacculi of guinea pig labyrinth. An immunohistochemical study

The neuropeptides Substance P, beta-Endorphin, Prolactin, Cholecystokinin, and Glucagon were investigated by means of Sternbergers PAP technique in the neuroepithelium of the Maculae utriculi and sacculi of the labyrinth of newborn guinea pigs. This brief report will show the localization of some neuropeptides in the neuroepithelium of the Maculae utriculi and sacculi. We could not find information about similar studies on this topic in the literature. In connection with investigations of the sensory apparatus of the inner ear we have recently presented neuropeptides evidence for the presence of certain peptides in the Ggl. spirale and the hair cells of the organ of Corti. With this paper we continue to report on neuropeptides in the labyrinth of the juvenile guinea pig as revealed by immunohistochemistry (Nowak et al., in press).

Occurrence of cysteine proteinase inhibitors in cells of the monocytic-histiocytic system. An immunohistochemical investigation

Human tissues are known to contain two low molecular weight (MW about 12,000) cysteine proteinase inhibitors, i.e. an acid inhibitor (ACPI) with pI 4.7-5.0 and a neutral inhibitor (NCPI) with pI 6.0-6.5. ACPI is abundant in cornifying epithelial tissues and in the dendritic reticulum cells of germinal centres of the lymph nodes. NCPI is abundant in lymphatic tissue and is known to be synthesized and released by mononuclear phagocytes. In this report NCPI was localized immunohistochemically in the epitheloid cells of most sarcoidotic lymph nodes, in lymph node macrophages after lymphangiography and in alveolar macrophages, while no ACPI could be demonstrated in the same cells by similar methods. These inhibitors were not demonstrable in lymph node sinus histiocytosis. Peripheral blood monocytes did not exhibit any NCPI immunoreactivity. In occasional blood monocytes anti-ACPI serum gave a weak reaction, the specificity of which is questionable. These data suggest that studies on cysteine proteinase inhibitors reveal basic differences in the various histiomonocytic cells and possibly differences in their functional stages.

Dendritic reticulum cells in AIDS-related lymphadenopathy

One of two cases of acquired immune deficiency syndrome-related persistent generalized lymphadenopathy revealed a profoundly altered pattern of dendritic reticulum cells as demonstrated by immunoreactive acid cysteine proteinase inhibitor. The alterations could be related to totally or partially destructed lymphoid secondary follicles.

Behaviour of dendritic reticulum cells possessing immunoreactive acid cysteine-proteinase inhibitor in human lymphoid secondary follicles and in follicular-centre cell lymphomas

In our previous studies acid cysteine-proteinase inhibitor (ACPI) was shown to be a common characteristic of human squamous epithelia and dendritic reticulum cells (DRC) in lymphoid secondary follicles. In the present study, the behaviour of ACPI-immunoreactive DRC in reactive lymphoid secondary follicles and neoplastic follicles of follicular-centre cell (FCC) lymphomas was compared by the peroxidase-antiperoxidase method. The secondary follicles in reactive lymphoid tissues revealed a staining pattern characteristic of DRC comparable with the results of other studies. Contrary to this, the number of ACPI-positive DRC in the neoplastic lymphoid follicles was greatly reduced. This was occasionally accompanied by a weak reaction and in many cases the DRC were totally abolished. Moreover, morphological aberrations were observed in ACPI-positive DRC, especially diminution and shortening of dendritic processes. On occasion, ACPI-positive cell types were observed, which may represent intermediate forms between DRC and fibroblastic reticulum cells. Only one case--with a rather favourable clinical outcome (out of 41 follicular FCC lymphomas) exhibited an ACPI-positive DRC pattern comparable with that of reactive lymphoid follicles. Thus it seems that the ACPI-immunohistochemistry of DRC provides an additional tool for discerning the difference between reactive and neoplastic lymphoid follicles. This method is of particular value since it can be used with formalin-fixed, paraffin-embedded tissues. There was a tendency among the follicular FCC lymphoma patients towards a better survival rate for those with ACPI-positive DRC than for those lacking this cell type, although no statistically significant differences emerged from this limited material.

Serum cysteine proteinase inhibitors with special reference to kidney failure

Serum levels of proteins reactive in radioimmunoassay with an antiserum prepared in rabbits against purified human spleen neutral cysteine proteinase inhibitor (NCPI) was determined in 70 healthy controls and from 80 patients suffering from suspected or proven kidney failure. The values varied from less than 0.2 mg/l in normal sera to levels over 2 mg/l in some patient sera. Serum level of NCPI was found to roughly correlate with serum creatinine values. However, there were sera with high NCPI levels which did not have increased serum creatinine values. In sera with high NCPI levels subjected to double radial immunodiffusion two precipitin lines, one completely and the other partially identical to NCPI were registered. After fractionating of serum proteins with gel chromatography on Sephadex G 100, two protein peaks of immunological similarity to purified NCPI were found: one low molecular weight (MW around 12,000) and one high molecular weight (MW around 100,000). The low molecular weight NCPI-like material appeared to inhibit human cathepsin B and papain and is thus free serum NCPI. alpha-Cysteine proteinase inhibitor did not increase with serum creatinine as did NCPI.

Localization of cathepsin H and its inhibitor in the skin and other stratified epithelia

The rat-skin-derived cysteine proteinase, so-called BANA-hydrolase, which is capable of hydrolysing benzoylarginine naphthylamide and leucine naphthylamide was shown to be immunologically identical to cathepsin H purified from rat liver. The enzyme was immunocytochemically localized in the basal cell layer of rat epidermis. A natural inhibitor of cathepsin H with a molecular weight of about 13,000 was mainly localized in the keratinizing cell layers and showed only a weak reaction in the basal cells. Thus, cathepsin H appears to be a characteristic feature of the proliferating cell layer, whereas the cysteine-proteinase inhibitor is a characteristic feature of keratinizing cells.

Acid and neutral cysteine proteinase inhibitor in normal uterine portio and in squamo-epithelial metaplasia, dysplasias and infiltrative carcinoma of the uterine portio

Acid cysteine proteinase inhibitor (ACPI) and neutral cysteine proteinase inhibitor (NCPI) were localized in formalin-fixed normal human uterine portio as well as in the squamous cell carcinoma and dysplasias of the uterine portio. The peroxidase-antiperoxidase technique was used. In the squamous epithelium of normal uterine portio, ACPI and NCPI were localized in the cells of the upper and middle layers, mainly in the cytoplasm. In the precursors of cancer, immunoreactivity for ACPI and NCPI declined, and neither of the inhibitors was demonstrable immunohistochemically in the anaplastic squamo-epithelial carcinoma of the uterine portio. Our results suggest that ACPI and NCPI are associated with squamo-epithelial differentiation and that they may also be of significance for the regulation of cysteine proteinase activity in normal tissue and malignant growth.

Distribution of cathepsin D immunoreactivity in the central nervous system of rat and selected brain regions of man

The regional distribution and cellular localization of cathepsin D immunoreactivity was demonstrated at the light microscopic level in the CNS of rat and man by use of unlabelled immunoenzyme technique. A wide but uneven distribution was substantiated for the rat brain. Furthermore, we present evidence that antiserum produced against rat liver enzyme is capable of recognizing cathepsin D in human brain.

Acid cysteine-proteinase inhibitor, a new characteristic of reticulum cells in human lymphoid secondary follicles

Reactive lymph nodes, palatine tonsils and thyroid tissues infiltrated with reactive lymphatic tissue were studied for the presence of immunoreactive acid cysteine-proteinase inhibitor (ACPI). A positive reaction for ACPI was found in germinal centres in all the above tissue types. The morphology and distribution of the positive cells indicated immunoreactivity in the dendritic reticulum cells (DRC). A positive reaction was also found in starry sky cells when a strong starry sky reaction was present in germinal centres. ACPI-positive cells of dendritic appearance were also found outside the secondary follicles in tonsillar tissue from cases of chronic or recurrent tonsillitis, especially between the follicles and the crypt epithelium, in some lymph nodes exhibiting a strong follicular reactive hyperplasia and in thyroid tissue in one case of Hashimoto's thyroiditis. A close anatomical and morphological relationship is pointed out between ACPI reactive dendritic cells and epithelial tissue. This is especially true of the tonsillar crypt epithelium and adjacent lymphoid secondary follicles. The tonsillar crypt epithelium sometimes formed a loose, web-like structure with enmeshed lymphoid cells, even reminiscent of dendritic compartmentalization of lymphoid secondary follicles. The results suggest that ACPI-immunoreactivity of DRC could be a function of the outer membrane of dendritic processes, and thus could be in some way a parallel phenomenon to the morphological expression of the well-established function of DRC in capturing antigen and immune complexes.

Production of acid and neutral cysteine-proteinase inhibitors by a cultured human skin epithelium cell line

Human skin epithelial-like cells (NCTC-strain 2544) were grown in RPMI-1640 medium supplemented with foetal calf serum for up to 2 weeks. The culture medium and extracts made from the cells were subjected to gel-filtration chromatography in a Sephacryl S-200 column for fractionation of the proteins. The fractions were assayed for acid and neutral cysteine-proteinase inhibitor (ACPI, NCPI) using time-resolved fluoroimmunoassay and radioimmunoassay, and the cysteine-proteinase-inhibiting activities were assayed using papain. Free NCPI, i.e. a molecule with isoelectric variants at pHs 6.0 and 6.5, which has an Mr of around 12,000 and is capable of inhibiting papain, was detected both in the culture medium and in the cells. Immunodiffusion studies revealed its immunological identity with human spleen-derived NCPI. The amount of NCPI increased during the incubation period. ACPI--characterized as a molecule having an isoelectric point of 4.9, an Mr of about 12,000, papain-inhibiting capacity and antigenic reactivity with spleen-derived ACPI--was not detected in the culture medium. It was, however, detected in the cells after 2 weeks in culture. These data prove that ACPI and NCPI are synthesized by the NCTC-2544 cells under the present culture conditions.

Atrial natriuretic factor. Immunohistochemical localization in the specific atrial granules of the rat heart

Atrial natriuretic peptides (atrial natriuretic factor, ANF) were localized in rat heart atria using immunohistochemical methods. A large number of heavily stained granules were detected mainly in the vicinity of the nuclei of the atrial muscle cells, but some staining was also present in granules located near the sarcolemma. The results show that the specific atrial granules are loaded with atrial natriuretic peptides.

Brain gastrin/CCK immunoreactivity in sand rat (Psammomys obesus): decrease of number of positive neurons in diabetic animals

Gastrin/CCK immunoreactivity appears to be widely distributed throughout the mammalian CNS, being most abundant in the cerebral cortex [Vanderhaeghen et al. 1975; Straus et al. 1977; Beinfeld et al. 1981]. Besides its putative role as a co-transmitter in dopaminergic neurotransmission [Hökfelt et al. 1980], cholecystokinin is apparently involved in the central regulation of appetite and satiety [Gibbs et al. 1973; Antin et al. 1975; Parret and Batt 1980; Smith 1980; Smith and Gibbs 1981] Furthermore, it has been shown that the brain concentration of the peptide is decreased in genetically obese mice as compared to non-obese animals [Strauss and Yalow 1979]. The sand rat (Psammomys obesus) is a desert rodent which tends to become diabetic when it is fed with normocaloric diet and restricted in movement [Haines et al. 1965; Hahn et al. 1971]. However, the usefulness of this animal as a paradigm of diabetes is now being revised, since because in its typical expression this metabolic dysfunction appears to be an obesity syndrome [Rice and Robertson 1980]. Therefore, it seems to be necessary to study the distribution of gastrin/CCK-immunoreactive nerve cells in the brain of normal and diabetic (obese) sand rats to get further information about mechanism underlying the development of this form of diabetes.

Partial purification and some properties of a new papain inhibitor from psoriatic scales

A new papain inhibitor was purified from psoriatic epidermal scales using gel chromatography and anion exchange chromatography. The purified protein inhibited papain and ficin but not cathepsin B, cathepsin H, trypsin, or chymotrypsin. Isoelectric focusing revealed 3 major inhibitor variants with pI's of 7.3, 6.9, and 6.5. A Mr of 38,000 was obtained by a gel chromatographic method for the crude inhibitor. After sodium dodecyl sulfate-polyacrylamide gel electrophoresis the Mr values of the isoelectric variants were: 43,000 for the variant pI 7.3, 43,000 and 35,000 for the variant pI 6.9, and 34,000-35,000 for the variant pI 6.5. An antiserum of the inhibitor was used to locate the inhibitor in the psoriatic and normal epidermis. In psoriatic epidermis, the inhibitor was found in the peripheral cytoplasm of spinous cells and in the scale. In normal epidermis, the staining was seen only in orifices of hair follicles. An inhibitor with similar size and antigenic properties to that isolated from the psoriatic scales was demonstrated in extracts made from the whole-thickness epidermis but not in extracts from the healthy epidermal scales, the dermis, the liver, the spleen, or the blood serum.

Cysteine proteinase inhibitors produced by mononuclear phagocytes

Monocytes were separated from human peripheral blood and allowed to attach to culture flasks, after which the content and production of a number of cysteine proteinase inhibitors was assayed. These were: a low molecular weight (MW 12000) acid cysteine proteinase inhibitor (ACPI); a low-molecular weight inhibitor of the same size with neutral pH (NCPI), and alpha-cysteine proteinase inhibitor with a molecular weight around 90 000 (alpha-CPI). Only NCPI was detectable in the cultures at the beginning of the incubation, and it was synthesized and released into the incubation mixture during the incubation, especially if the cells were stimulated with silica. The amount of NCPI contained in and released from the cells was drastically decreased by puromycin. Immunoblots after cell electrophoresis in polyacrylamide gel revealed only one molecular form of NCPI with a molecular weight of 12 000 both in the cells and in the culture medium. No ACPI or alpha-CPI could be detected.

Occurrence of acid and neutral cysteine proteinase inhibitors in epidermal malignancies: immunohistochemical study

Acid cysteine proteinase inhibitor ( ACPI ) and neutral cysteine proteinase inhibitor ( NCPI ) were localized in human epidermal malignancies by the unlabelled peroxidase-antiperoxidase complex method. Basaliomas did not contain ACPI or NCPI . In spinous, metatypic , and clear cell carcinomas of the epidermis, both inhibitors were located in the cytoplasm and sometimes on the cell membranes of the differentiated carcinoma cells. The inhibitors were not seen in the 1 or 2 most "basal" cells layers of the carcinoma islets. The locations of both inhibitors were similar, and the staining for ACPI was usually more intense than staining that NCPI .