[Esterase XX. Disc-electrophoretic investigations on the polymorphism of the esterases of the house mouse (author's transl)]

A discrete subpopulation of dendritic cells transports apoptotic intestinal epithelial cells to T cell areas of mesenteric lymph nodes

This study identifies a dendritic cell (DC) subset that constitutively transports apoptotic intestinal epithelial cell remnants to T cell areas of mesenteric lymph nodes in vivo. Rat intestinal lymph contains two DC populations. Both populations have typical DC morphology, are major histocompatibility complex class II(hi), and express OX62, CD11c, and B7. CD4(+)/OX41(+) DCs are strong antigen-presenting cells (APCs). CD4(-)/OX41(-) DCs are weak APCs and contain cytoplasmic apoptotic DNA, epithelial cell-restricted cytokeratins, and nonspecific esterase (NSE)(+) inclusions, not seen in OX41(+) DCs. Identical patterns of NSE electrophoretic variants exist in CD4(-)/OX41(-) DCs, intestinal epithelial cells, and mesenteric node DCs but not in other DC populations, macrophages, or tissues. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL)-positive DCs and strongly NSE(+) DCs are present in intestinal lamina propria. Peyer's patches and mesenteric but not other lymph nodes contain many strongly NSE(+) DCs in interfollicular and T cell areas. Similar DCs are seen in the ileum and in T cell areas of mesenteric nodes in gnotobiotic rats. These results show that a distinct DC subset constitutively endocytoses and transports apoptotic cells to T cell areas and suggest a role for these DCs in inducing and maintaining peripheral self-tolerance.

Nonspecific esterases of mammalian testis. Comparative studies on the mouse (Mus musculus) and rat (rattus norvegicus)

Ten different nonspecific esterases in both mouse (Mus musculus) and rat (Rattus norvegicus) testis were identified following the analysis of electrophoretic patterns using genetic, developmental, and biochemical criteria. None of the enzymes were unique to testis, although the pattern of activity was testis specific. The enzymes comprised, in each species, six carboxylesterases (EC 3.1.1.1), one arylesterase (EC 3.1.1.2), one acetylesterase (EC 3.1.1.6), and two butyrylesterases (tentative designation). Cholinesterase (EC 3.1.1.8) was not detected. Individual homology relationships were recognized between the two species for all of these activities, except three of the carboxylesterases; however, these were coded for by homologous gene clusters. Similarities between the two species extended to the developmental course of expression and the modulation of the pattern of activity by the testicular feminization (Tfm) mutation. We describe the effects of the sex reversal (Sxr) mutation in the mouse, as well as the distribution of individual activities between Leydig cells and seminiferous tubules. The results of earlier histochemical studies are interpreted in the light of the present investigation. The correspondence between mouse- and rat-testis esterases suggests that the results could serve as a basis for mammalian testis esterase systems in general.

Identification and development of a genetically closely-linked carboxylesterase family of the mouse liver

Six carboxylesterase isozymes (viz. ES-1, ES-6, ES-9, ES-20, ES-22 and ES-24), governed by esterase gene cluster 1 on chromosome 8 of the house mouse, were identified electrophoretically in liver supernatants using their biochemical, genetic and developmental characteristics. ES-1 and ES-20 were expressed as liver-specific forms. The peri- and postnatal development of the six isozymes indicated that they were individually regulated at the genetic level, although the isozymes were regulated as a group when compared to genetically unrelated esterases. The concept of evolutionary divergence following repeated gene duplication of an ancestral esterase structural gene was extended to cover divergence of the temporal (regulatory) genes associated with the multigene family. Allelic variation of the temporal genes was more limited than that of the corresponding structural genes.

Changes in muscle esterases in genetically dystrophic and control littermate mice

The hypothesis that the existence of a family of isoenzymes is at the basis of the heterogeneity of esterase activity among skeletal muscles from dystrophic Re 129J and control littermate mice was tested using isoelectrofocusing (IEF) in polyacrylamide gel. All muscles considered showed not only quantitative heterogeneity, as previously observed in this laboratory, but also qualitative differences with regard to their esterase isoenzymes. Differences in the number and the relative amounts of isoenzymatic bands were found between different muscles from both control and dystrophic animals. In most dystrophic muscles a new isoenzymatic band appeared at pH 6.6. Another band, identified at pH 5.12, was more pronounced in dystrophic than in control muscles. The specificity of these observations is indirectly supported by the fact that other tissue, such as heart, liver, and kidney, did not show the quantitative or qualitative abnormality present in the dystrophic skeletal muscles.

Kidney esterases of Mus musculus: further polymorphism of esterase-6, esterase-9, and a new esterase, esterase-20

The comparison of results obtained by different separation and staining techniques permits the definition of esterase-6 in comparison with esterase-9 and a new esterase, esterase-20. Alleles of Es-6 affect the product's ability to aggregate. Esterase-20 may be an aggregated product of Es-9. The close linkage of Es-6 and Es-9 is confirmed. Homology of esterase-6 with esterases from other mammalian species is also suggested.

Histochemical demonstration of mouse submandibular esterproteases with a new chromogenic substrate

A new method for the histochemical demonstration of mouse submandibular esterproteases has been developed. The substrate is N-acetyl-L-methionine alpha-naphthyl ester. The main enzyme reaction was found in the apical region of the secretory tubules with a marked sex difference as expected. First attempts were made to differentiate histochemically between the various esterproteolytic enzymes.

Esterase XXVII. Purification and characterization of esterase-9A of mouse kidney

Esterase-9A, which appears electrophoretically as a triplet of the bands III-50, III-40 and III-30, was isolated from the kidneys of male NMRI-mice by isoelectrofocusing and refocusing followed by repeated molecular sieve chromography. The overall purification was approx. 250 fold and each of the three bands was isolated separately. The band of the triplet nearest to the cathode, III-50, changed in vitro into the satellite bands III-40 and III-30 and, further, into the band III-22 not observed before in the homogenate. It is assumed that the band III-50 represents the original gene product. The molecular weight (45 000) of the band III-50 is identical with those of III-40 and III-30, as measured by analytical electrophoresis, whereas the molecular weight obtained by thin-layer chromatography was 51 000. There were no obvious signs that esterase-9 was composed of subunits. The Km constant for 4-nitrophenyl proprionate was identical for each of three bands. The esterase-9A is the first testosterone-dependent isozyme of the mouse carboxylesterase (carboxylicester hydrolase, EC 3.1.1.1) system which has been isolated.

Esterase. XXIII. Electron microscopical demonstration of non-specific esterases in the jejunum of the mouse (Mus musc.) with two quinoline derivatives

The intracellular distribution of non specific esterases in various villous cells of mouse jejunum was investigated using two substrates, 8-acetoxiquinoline (Q-O-2) and 8-acetyl mercaptoquinoline (Q-S-2) respectively. With the more selectively staining Q-S-2 a uniform reaction was demonstrated in all enterocytes which was mainly located in the endoplasmic reticulum and the nuclear envelope. Possibly it is a matter of a single enzyme being hardly detachable from the membranes. With the non selectively staining Q-O-2 several esterases were demonstrated Es-2, adn Es-9 among them. The main reaction was found in columnar and Goblet cells, in both at all cellular membranes and in the mitochondrial matrix, additionally in cisterns and vesicles of the endoplasmic reticulum and of the Golgi apparatus and at lipid droplets of the former, finally at mucous droplets of the latter. An extracellular reaction was found in the intercellular cleft and between the microvilli of the brush border.

Esterase. XXII. Cellular and subcellular localisation of the Es-9 esterase in mouse kidney

Among the various esterases of the mouse kidney the Es-9 esterase is outstanding in that it is fully repressed in the cortical proximal tubulus in the absence of testosterone but is constitutive in the terminal parts of the proximal tubulus. Thus, this enzyme is regulated in a different way in closely neighboured sections of the tubular system. Comparing the disc electrophoretic patterns of the kidney esterases with the distribution of esterases in ultrathin sections as revealed by electron microscopy it is concluded that the Es-9 esterase is located in the mitochondria.

Enzyme histochemistry as a link between biochemistry and morphology

The presented paper describes the role of enzyme histochemistry in cell biological investigations. In the first chapter a general discussion has been given about enzyme histochemistry as a connecting link between biochemistry and morphology. The methods available for determination of enzymes in a particular cell or cell compartment have been reviewed. In this respect the characteristics of enzyme histochemistry have been discussed. Furthermore, attention has been paid to the possibilities and limitations of enzyme histochemistry. In chapter two a comparison has been made between histochemically judged and biochemically determined enzyme activities. Some fundamental differences between the biochemical and the histochemical approach in cell biological investigations are dealt with. To correlate histochemically and biochemically determined enzyme activities, a description has been given of the application of histochemical methods on isolated fractions and sucrose-ficoll gradients of these fractions. Several experimental results are described concerning the question whether a relation exists between histochemically and biochemically determined activities of respectively alkaline phosphatase, glucose-6-phosphatase, 5'-nucleotidase and 3ss-hydroxysteroid dehydrogenase. From these results the conclusion could be drawn that in general a good correlation exists between histochemically judged activity per volume (area X thickness) and biochemically determined activity per gram tissue. In chapter three the role of enzymes as markers of cellular particles and as parameters of metabolic pathways is described. Histochemical methods are available for most marker enzymes. Only activities of key enzymes can be regarded as parameters of metabolic pathways. The distribution in sucrose-ficoll gradients of enzymes, regarded as markers of mitochondria, lysosomes, endoplasmic reticulum and plasma membranes has been given. The changes occur ing under different experimental conditions for a number of marker enzymes in rat liver are described. Attention has been given to the contibution of enzyme histochemistry in the study of the heterogeneity of mitochondria, the dual localization of some (lysosomal) enzymes, the complexity of the microsomal fraction, the function of the Golgi apparatus and the heterogeneity and function of plasma membranes. Based on these results and on literature findings the possible role of some marker enzymes in cell metabolism has been discussed. In chapter four problems coherent with species and sex differences in enzyme activities are described. The interpretation of histochemical and biochemical results in view of these differences is discussed. Enzymes characteristic for a given cell type -3ss-hydroxysteroid dehydrogenase in steroid producing cells, ATP-ase in liver plasma membrane surrounding the bile canaliculi - do show less variations between species and sexes than enzymes not directly involved in specialized functions...