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Endogenous inhibitor for calcium-dependent cysteine protease contains four internal repeats that could be responsible for its multiple reactive sites.

A cDNA encoding an endogenous inhibitor, termed calpastatin, for calcium-dependent cysteine protease (calpain, EC 3.4.22.17) was cloned by screening rabbit cDNA libraries with a synthetic oligodeoxynucleotide probe based on the partial amino acid sequence of the purified protein. The deduced amino acid sequence contains 718 amino acid residues (Mr, 76,964), and the mature protein corresponds to the deduced sequence from the 80th residue of the primary translation product (resultant Mr, 68,113). This deduced molecular weight is significantly lower than that determined by NaDodSO4/polyacrylamide gel electrophoresis, suggesting the possibility that the inhibitor is post-translationally modified. The sequence of the mature inhibitor contains four consecutive internal repeats approximately 140 amino acid residues long, each of which might be responsible for the inhibitory activity. Calpastatin is apparently different from a typical cysteine protease inhibitor (cystatin), suggesting that the mechanism of inhibition of calcium-dependent cysteine protease by the inhibitor might be different from that of other cysteine proteases by cystatin.

Amino Acid Sequence↗

Cloning, isolation, and characterization of mammalian legumain, an asparaginyl endopeptidase.

Legumain is a cysteine endopeptidase that shows strict specificity for hydrolysis of asparaginyl bonds. The enzyme belongs to peptidase family C13, and is thus unrelated to the better known cysteine peptidases of the papain family, C1 (Rawlings, N. D., and Barrett, A. J. (1994) Methods Enzymol. 244, 461-486). To date, legumain has been described only from plants and a blood fluke, Schistosoma mansoni. We now show that legumain is present in mammals. We have cloned and sequenced human legumain and part of pig legumain. We have also purified legumain to homogeneity (2200-fold, 8% yield) from pig kidney. The mammalian sequences are clearly homologous with legumains from non-mammalian species. Pig legumain is a glycoprotein of about 34 kDa, decreasing to 31 kDa on deglycosylation. It is an asparaginyl endopeptidase, hydrolyzing Z-Ala-Ala-Asn-7-(4-methyl)coumarylamide and benzoyl-Asn-p-nitroanilide. Maximal activity is seen at pH 5.8 under normal assay conditions, and the enzyme is irreversibly denatured at pH 7 and above. Mammalian legumain is a cysteine endopeptidase, inhibited by iodoacetamide and maleimides, but unaffected by compound E64 (trans-epoxysuccinyl-L-leucylamido-(4-guanidino)butane). It is inhibited by ovocystatin (cystatin from chicken egg white) and human cystatin C with Ki values < 5 nM. We discuss the significance of the discovery of a cysteine endopeptidase of a new family and distinctive specificity in man and other mammals.

Amino Acid Sequence↗

Equistatin, a new inhibitor of cysteine proteinases from Actinia equina, is structurally related to thyroglobulin type-1 domain.

It is well known that the activities of the lysosomal cysteine proteinases are tightly regulated by their endogenous inhibitors, cystatins. Here we report a new inhibitor of cysteine proteinases isolated from sea anemone Actinia equina. The inhibitor, equistatin, is an acidic protein with pI 4.7 and molecular weight of 14,129. It binds tightly and rapidly to cathepsin L (ka = 5.7 x 10(7) M-1 s-1, Ki = 0.051 nM) and papain (ka = 1.2 x 10(7) M-1 s-1, Ki = 0.57 nM). The lower affinity for cathepsin B (Ki = 1.4 nM) was shown to be due mainly to a lower second order association rate constant (ka = 0.04 x 10(6) M-1 s-1). The inhibitor is composed of 128 amino acids forming two repeated domains with 48% identity. Neither of the domains shows any sequence homology to cystatins, but they do show a significant homology to thyroglobulin type-1 domains. A highly conserved consensus sequence motif of Cys-Trp-Cys-Val together with conserved Cys, Pro, and Gly residues is present in major histocompatibility complex class II-associated p41 invariant chain, nidogen, insulin-like growth factor proteins, saxiphilin domain a, pancreatic carcinoma marker proteins (GA733), and chum salmon egg cysteine proteinase inhibitor. In each of the domains of the equistatin, the three residues are similarly conserved, and the sequences Val-Trp-Cys-Val and Cys-Trp-Cys-Val are present in domains a and b, respectively. We suggest that equistatin belongs to a new superfamily of protein inhibitors of cysteine proteinases named thyroglobulin type-1 domain inhibitors. This superfamily currently includes equistatin, major histocompatibility complex class II- associated p41 invariant chain fragment, and chum salmon egg cysteine proteinase inhibitor.

Amino Acid Sequence↗

Serum concentrations of sex hormone binding globulin are elevated in kwashiorkor and anorexia nervosa but not in marasmus.

BACKGROUND: Customary blood protein markers for malnutrition are of limited value in the diagnosis of protein-energy malnutrition or anorexia nervosa in children and in the follow-up to refeeding in such children. OBJECTIVES: For these diseases, we compared the diagnostic value of sex hormone binding globulin (SHBG) with that of albumin, transferrin, transthyretin, and retinal binding protein and determined the relations between concentrations of insulin, insulin-like growth factor I, and SHBG. DESIGN: SHBG was assayed in children with protein-energy malnutrition (29 children with kwashiorkor and 28 with marasmus), in 29 anorectic girls (before and after refeeding), and in age- and sex-matched control subjects. RESULTS: Mean (+/-SE) serum SHBG concentrations were higher in the children with kwashiorkor (0.18 +/- 0.07 micromol/L) than in the children with marasmus (0.11 +/- 0.05 micromol/L, P < 0.0001) or the control subjects (0.11 +/- 0.03 micromol/L, P < 0.0005). In the children with anorexia nervosa before weight gain, serum SHBG concentrations were significantly higher (0.10 +/- 0.04 micromol/L) than in the age-matched control subjects (0.06 +/- 0.03 micromol/L, P < 0.001) and decreased significantly after 30 d of refeeding (0.04 +/- 0.01 micromol/L, P < 0.0001). This decrease was negatively correlated with insulin-like growth factor I but not with insulin. Mean serum SHBG concentrations were influenced neither by inflammation, as indicated when C-reactive protein was used as a marker (0.27 +/- 0.27, 0.34 +/- 0.42, and <0.04 micromol/L in the children with marasmus, kwashiorkor, and anorexia nervosa, respectively), nor by glomerular filtration, as indicated when cystatin-C was used as a marker (68.46 +/- 23.08, 66.90 +/- 43.08, and 49.23 +/- 7.69 micromol/L, respectively). CONCLUSIONS: The high SHBG concentration observed in anorexia nervosa and kwashiorkor seems to be of multifactorial origin. For these 2 diseases, SHBG is a reliable marker of nutritional status, is unrelated to either C-reactive protein or cystatin-C, and may be helpful in distinguishing kwashiorkor from marasmus and as a follow-up marker after refeeding.

Adolescent↗

Crystal structure of MHC class II-associated p41 Ii fragment bound to cathepsin L reveals the structural basis for differentiation between cathepsins L and S.

The lysosomal cysteine proteases cathepsins S and L play crucial roles in the degradation of the invariant chain during maturation of MHC class II molecules and antigen processing. The p41 form of the invariant chain includes a fragment which specifically inhibits cathepsin L but not S. The crystal structure of the p41 fragment, a homologue of the thyroglobulin type-1 domains, has been determined at 2.0 A resolution in complex with cathepsin L. The structure of the p41 fragment demonstrates a novel fold, consisting of two subdomains, each stabilized by disulfide bridges. The first subdomain is an alpha-helix-beta-strand arrangement, whereas the second subdomain has a predominantly beta-strand arrangement. The wedge shape and three-loop arrangement of the p41 fragment bound to the active site cleft of cathepsin L are reminiscent of the inhibitory edge of cystatins, thus demonstrating the first example of convergent evolution observed in cysteine protease inhibitors. However, the different fold of the p41 fragment results in additional contacts with the top of the R-domain of the enzymes, which defines the specificity-determining S2 and S1' substrate-binding sites. This enables inhibitors based on the thyroglobulin type-1 domain fold, in contrast to the rather non-selective cystatins, to exhibit specificity for their target enzymes.

Amino Acid Sequence↗

Creatine supplementation does not affect kidney function in an animal model with pre-existing renal failure.

BACKGROUND: Creatine is widely used as an ergogenic substance among athletes. Safety of prolonged creatine intake has been questioned, based upon case reports and animal data. We investigated the effect of prolonged creatine ingestion on renal function in animals with normal kidney function or pre-existing kidney failure, respectively. METHODS: Male Wistar rats were randomly allocated to four experimental groups: (i) sham-operated, control diet; (ii) sham-operated, creatine-supplemented diet (2% w/w (0.9+/-0.2 g creatine/kg body weight/day)); (iii) two-thirds nephrectomized, control diet; and (iv) two-thirds nephrectomized, creatine supplemented diet. Glomerular filtration rate was determined using inulin and creatinine clearance, together with albumin excretion, urea clearance, muscle and serum creatine and serum cystatin C concentrations. RESULTS: In contrast to previous reports, no detrimental effects of creatine supplementation on the renal function indices were observed in two-thirds nephrectomized or sham-operated animals. No differences were observed in inulin (0.28+/-0.08 vs 0.25+/-0.08 ml/min/100 g; P=NS) or creatinine clearance rates. Serum cystatin C concentration, urinary protein excretion, and albumin and urea clearance were comparable between creatine-supplemented and control-diet fed animals in both sham-operated and two-thirds nephrectomized animals. Serum creatine and intramuscular total creatine concentrations were higher in creatine-supplemented groups (P<0.05). CONCLUSIONS: Creatine supplementation at a dosage of 2% w/w for 4 weeks does not impair kidney function in animals with pre-existing renal failure or in control animals.

Albuminuria↗

Structural characterization of the gene for human histidine-rich glycoprotein, reinvestigation of the 5'-terminal region of cDNA and a search for the liver specific promoter in the gene.

Genomic DNA libraries were screened for the human histidine-rich glycoprotein (HRG) gene and a sequence of 15,499 nucleotides was determined. The gene is composed of 7 exons and 6 introns, and all the exon-intron boundaries match the consensus GT/AG sequence for donor and acceptor splice sites. Each of cystatin-like domains I and II of HRG is encoded by three exons, exons I to III and exons IV to VI, respectively, like those of other members of the cystatin superfamily. The entire C-terminal half of the molecule is encoded by the largest exon, VII. The first 103 nucleotides of the cDNA sequence reported for human HRG [Koide, T., Foster, D., Yoshitake, S. , and Davie, E.W. (1986) Biochemistry 25, 2220-2225] could not be found in the determined gene sequence. A homology search of this sequence against a database showed the complete matching to a part of the yeast mitochondrial DNA encoding 21S ribosomal RNA. Rapid amplification of cDNA 5' ends (5'-RACE) analysis revealed that the cDNA has multiple 5'-ends and that a possible starting point is nucleotide 104 of the reported cDNA sequence. These results suggest that the first 103 nucleotides of the cDNA sequence reported for human HRG originated from yeast mitochondrial DNA and were incidentally incorporated into the HRG cDNA in the process of the construction of a cDNA library. Various fragments obtained on restriction endonuclease digestion of the 5'-noncoding region of the HRG gene were ligated to the chloramphenicol acetyltransferase (CAT) gene and then transfected into HepG2 and 293 cells to analyze the promoter activity. The sequence between -262 and -21 from the putative translation initiation site supported the expression of CAT in HepG2 cells but not in 293 cells, suggesting that this segment promotes the liver-specific transcription of the human HRG gene.

5' Untranslated Regions↗

Cysteine protease inhibitor in egg of chum salmon.

Two different cysteine protease inhibitors (Forms I and II) were isolated from chum salmon egg, and their molecular weights were found to be 16,000 and 11,000, respectively. When the N-terminal amino acid sequences of Forms I and II were compared, 67% of the residues were identical but no apparent homology was found between these inhibitors and cystatins of higher vertebrates. Because the amounts of half-cystine were estimated to be 7-8 residues per molecule, they can be classified into a new group of the cystatin superfamily.

Amino Acid Sequence↗

Precise and efficient cleavage of recombinant fusion proteins using mammalian aspartic proteases.

Expression of recombinant proteins as translational fusions is commonly employed to enhance stability, increase solubility and facilitate purification of the desired protein. In general, such fusion proteins must be cleaved to release the mature protein in its native form. The usefulness of the procedure depends on the efficiency and precision of cleavage and its cost per unit activity. We report here the development of a general procedure for precise and highly efficient cleavage of recombinant fusion proteins using the protease chymosin. DNA encoding a modified pro-peptide from bovine chymosin was fused upstream of hirudin, carp growth hormone, thioredoxin and cystatin coding sequences and expressed in a bacterial Escherichia coli host. Each of the resulting fusion proteins was efficiently cleaved at the junction between the pro-peptide and the desired protein by the addition of chymosin, as determined by activity, N-terminal sequencing and mass spectrometry of the recovered protein. The system was tested further by cleavage of two fusion proteins, cystatin and thioredoxin, sequestered on oilbody particles obtained from transgenic Arabidopsis seeds. Even when the fusion protein was sequestered and immobilized on oilbodies, precise and efficient cleavage was obtained. The precision, efficiency and low cost of this procedure suggest that it could be used in larger scale manufacturing of recombinant proteins which benefit from expression as fusions in their host organism.

Amino Acid Sequence↗

Rapid elimination by glomerular filtration of free prostate specific antigen and human kallikrein 2 after renal transplantation.

PURPOSE: The low molecular mass and short half-life of free (f) prostate specific antigen (PSA) implies elimination from blood by glomerular filtration. In addition, patients with terminal renal failure have increased fPSA in serum but there have been sparse data reported on the rates and pathways of elimination of PSA complexes and human kallikrein 2 (hK2). We studied glomerular filtration dependent elimination of fPSA and hK2 in patients with renal insufficiency undergoing successful renal transplantation. MATERIALS AND METHODS: We studied 14 patients with immediate onset of renal function after renal transplantation. Blood samples were obtained before and at regular intervals up to 160 hours after transplanted kidney reperfusion. Measurements of fPSA, total PSA and hK2 were performed with immunofluorometric assays and complexed PSA was determined by a chemiluminiscence assay. Glomerular filtration rates were monitored by analyzing serum creatinine and cystatin C. NONMEM, a multivariate pharmacokinetic approach, was used to determine the elimination rates of fPSA and hK2 after renal transplantation. RESULTS: Serum fPSA and hK2 but not PSA complexes, decreased rapidly after renal transplantation. Significant reductions in fPSA and hK2 were observed after only 16 and 8 hours, respectively. fPSA and hK2 showed similar elimination patterns, decreasing to 42% and 44% of their original levels compared to cystatin C, which was at 44% after 160 hours. The median half-lives of fPSA and hK2 were 17.4 and 11.5 hours, respectively. CONCLUSIONS: These results verify the hypothesis that fPSA and hK2 are eliminated from the blood circulation by glomerular filtration and severe renal failure influences the levels of the 2 proteins in serum.

Aged↗

Biomarkers of acute renal injury and renal failure.

Acute renal failure (ARF) is a frequent problem in the intensive care unit and is associated with a high mortality. Early recognition could help clinical management, but current indices lack sufficient predictive value for ARF. Therefore, there might be a need for biomarkers in detecting renal tubular injury and/or dysfunction at an early stage before a decline in glomerular filtration rate is noted by an increased serum creatinine. A MEDLINE/PubMed search was performed, including all articles about biomarkers for ARF. All publication types, human and animal studies, or subsets were searched in English language. An extraction of relevant articles was made for the purpose of this narrative review. These biomarkers include tubular enzymes (alpha- and pi-glutathione S-transferase, N-acetyl-glucosaminidase, alkaline phosphatase, gamma-glutamyl transpeptidase, Ala-(Leu-Gly)-aminopeptidase, and fructose-1,6-biphosphatase), low-molecular weight urinary proteins (alpha1- and beta2-microglobulin, retinol-binding protein, adenosine deaminase-binding protein, and cystatin C), Na+/H+ exchanger, neutrophil gelatinase-associated lipocalin, cysteine-rich protein 61, kidney injury molecule 1, urinary interleukins/adhesion molecules, and markers of glomerular filtration such as proatrial natriuretic peptide (1-98) and cystatin C. These biomarkers, detected in urine or serum shortly after tubular injury, have been suggested to contribute to prediction of ARF and need for renal replacement therapy. However, excretion of these biomarkers may also increase after reversible and mild dysfunction and may not necessarily be associated with persistent or irreversible damage. Large prospective studies in human are needed to demonstrate an improved outcome of biomarker-driven management of the patient at risk for ARF.

Acute Kidney Injury↗

Mycophenolate mofetil and sirolimus as calcineurin inhibitor-free immunosuppression for late cardiac-transplant recipients with chronic renal failure.

BACKGROUND: Calcineurin-inhibitor (CNI)-related renal failure is a common problem after cardiac transplantation (HTx). The aim of this study was to introduce a CNI-free immunosuppressive regimen to HTx recipients with late posttransplant renal impairment and to evaluate the impact of conversion to this new immunosuppression (mycophenolate mofetil [MMF] and sirolimus [Sir]) treatment on renal function. METHODS AND RESULTS: Thirty-one HTx patients (25 men, 6 women; 0.2-14.2 years after transplantation) with CNI-based immunosuppression and a serum creatinine greater than 1.9 mg/dL were included in the study. Creatinine and cystatin levels were monitored to detect renal function. Mean patient age was 50+/-14 (range 19-74) years. Conversion was started with 6 mg Sir, continued with 2 mg, and the dose was adjusted to achieve target trough levels between 8 and 14 ng/mL. MMF was continued with trough level adjusted (1.5-4 microg/mL). Subsequently, the CNIs were tapered down and stopped. Clinical follow-up (first and every 3 months after conversion) included endomyocardial biopsies, echocardiography, and laboratory studies. Survival was 90% after a mean follow-up of 13+/-95 months. No acute rejection episode was detected during the study period. Renal function improved significantly after conversion: creatinine preconversion vs. postconversion: 3.14+/-0.76 mg/dL vs. 2.14+/-0.83 mg/dL, P =0.001. Cystatin preconversion vs. postconversion: 2.95+/-1.06 mg/L vs. 2.02+/-1.1 mg/L, P =0.01. In three patients, hemodialysis therapy was stopped completely after conversion. Graft function remained stable. Fractional shortening preconversion vs. postconversion: 36.9+/-6% vs. 36.4+/-6%. There were no serious adverse events. One patient had to be excluded because of noncompliance. CONCLUSIONS: Conversion from CNI-based immunosuppression to MMF and Sir in HTx patients with chronic renal failure was safe, preserved graft function, and improved renal function.

Adult↗

Predictors of response to terlipressin therapy in hepatorenal syndrome: Metabolomic and proteomic analysis from the CONFIRM trial.

BACKGROUND: Terlipressin is the only FDA-approved vasoconstrictor for hepatorenal syndrome (HRS). The CONFIRM study is the largest trial of terlipressin versus placebo. Novel predictors of HRS response are required to enrich patient selection and optimize outcomes. METHODS: Samples at treatment initiation were tested using (a) liquid chromatography-mass spectrometry of 1594 plasma/1420 urine metabolites (Metabolon Inc.), (b) aptamer-based array of 7289 plasma proteins (SomaScan), and (c) 14 plasma/urine pre-specified assays. The CONFIRM trial's original definition of HRS response [2 serum creatinine (SCr) <1.5&#xa0;mg/dL separated by >2&#xa0;h] was used as the primary outcome. RESULTS: In all, 115 patients [79 terlipressin-treated (TT) and 36 placebo-treated (PT)] provided samples. Baseline characteristics, outcomes, and 2:1 TT:PT allocation were preserved from the original 300-patient trial. A total of 36 out of 116 (31.0%) patients achieved HRS reversal. HRS reversal was associated with lower SCr (p=0.001), cystatin C (p=0.005), angiopoietin-2 (p=0.04), and beta-2 microglobulin (p=0.006). In metabolite analysis, PT had the most significant differences in HRS reversal [n=26 plasma, n=50 urine, including lower urine levels of those centered on sulfated secondary bile acids (microbiome-derived), N-acetylated amino acids, catechols (both uremic toxins), and phosphocholines (cell membrane integrity)], with fewer in TT (n=1 plasma, n=2 urine), and in all patients (n=3 plasma, n=7 urine). There were no significant aptamers associated with HRS reversal after false-discovery correction. CONCLUSIONS: SCr, cystatin C, angiopoietin-2, and beta-2 microglobulin were associated with HRS reversal. Protein and metabolite signals centered on microbiome function and uremic toxins appeared more robust in PT patients, likely selecting a subgroup that may recover without terlipressin. Use of novel biomarkers may enrich for terlipressin response.

Humans↗

Degradation of host protease inhibitors and activation of plasminogen by proteolytic enzymes from Porphyromonas gingivalis and Treponema denticola.

Bacterial proteases may participate in the pathogenesis of periodontal diseases through their action on host proteins. In the present study, the ability of selected periodontopathogens, as well as two proteases isolated from Porphyromonas gingivalis and Treponema denticola, to degrade host protease inhibitors was evaluated. The activation of human plasminogen by the two bacterial proteases was also investigated. Proteolytic breakdown of host protease inhibitors (alpha-1-antitrypsin, antichymotrypsin, alpha 2-macroglobulin, antithrombin III, antiplasmin and cystatin C) was evaluated by SDS-PAGE. The 80 kDa trypsin-like protease of P. gingivalis completely digested the six protease inhibitors under investigation, whereas the 95 kDa chymotrypsin-like protease of T. denticola was slightly less active, more particularly on alpha 2-macroglobulin and cystatin C. When whole cells from a number of oral bacterial species were tested, the most significant degradation was obtained with P. gingivalis, T. denticola, Prevotella intermedia, Prevotella nigrescens and Capnocytophaga spp. Peptostreptococcus micros and Propionibacterium acnes had only some degradative activity on selected inhibitors, whereas three bacterial species, Actinobacillus actinomycetemcomitans, Bacteroides forsythus and Fusobacterium nucleatum, had no effect on the protease inhibitors. The 80 kDa protease of P. gingivalis demonstrated strong plasminogen activation, whereas no such activity was associated with the 95 kDa protease of T. denticola. This study indicates the high potential of some periodontal pathogens to destroy protease inhibitors and activate plasminogen. This may result in an uncontrolled degradation of periodontal tissues and a rapid progression of the disease.

Bacteroidaceae Infections↗

The involvement of cysteine proteases and protease inhibitor genes in the regulation of programmed cell death in plants.

Programmed cell death (PCD) is a process by which cells in many organisms die. The basic morphological and biochemical features of PCD are conserved between the animal and plant kingdoms. Cysteine proteases have emerged as key enzymes in the regulation of animal PCD. Here, we show that in soybean cells, PCD-activating oxidative stress induced a set of cysteine proteases. The activation of one or more of the cysteine proteases was instrumental in the PCD of soybean cells. Inhibition of the cysteine proteases by ectopic expression of cystatin, an endogenous cysteine protease inhibitor gene, inhibited induced cysteine protease activity and blocked PCD triggered either by an avirulent strain of Pseudomonas syringae pv glycinea or directly by oxidative stress. Similar expression of serine protease inhibitors was ineffective. A glutathione S-transferase-cystatin fusion protein was used to purify and characterize the induced proteases. Taken together, our results suggest that plant PCD can be regulated by activity poised between the cysteine proteases and the cysteine protease inhibitors. We also propose a new role for proteinase inhibitor genes as modulators of PCD in plants.

Amino Acid Sequence↗

Localization of mRNAs by in-situ hybridization to the residual body at stages IX-X of the cycle of the rat seminiferous epithelium: fact or artefact?

Several recent articles have reported localization of specific mRNAs in the rat testis to stage IX and X seminiferous tubules using in-situ hybridization. In all cases the expression was located basally in the tubules and appeared as discrete round clusters of grains close to the lamina propria. The localization was interpreted as being in Sertoli cells or leptotene spermatocytes. In this study we demonstrate that this pattern is most probably due to artefactual binding of probes to the residual body (RB). In the present study testicular tissue, perfusion-fixed with Bouin's and embedded in paraffin, was used, as this resulted in excellent morphological preservation such that RBs within tubules at stages VIII-X were clearly distinguishable. RNA content of the RBs was demonstrated at stages VIII-X using methyl green pyronin staining, and could be eliminated by pretreatment with RNAse or trichloroacetic acid. Localization of mRNAs for 11 seminiferous tubule proteins was assessed using 35S-labelled and digoxigenin-labelled riboprobes (activin receptor-II, alpha-inhibin, transferrin, androgen-binding protein (ABP), cyclic protein-2 (CP-2), CREM, sulphated glycoproteins 1 and 2 (SGP-1 and SGP-2), transition protein 2 (TP-2) and cystatin-C), and digoxigenin-labelled oligonucleotide probes (transition protein-1 (TP-1), TP-2 and protamine-1). All of these probes showed localization to the correct cell type(s) within the seminiferous epithelium. In addition, six antisense riboprobes (activin receptor-II, CREM, SGP-2, CP-2, cystatin C and alpha-inhibin) showed hybridization to basally located residual bodies in tubules at stages IX-X on one or more occasions, whereas residual bodies around the edge of the lumen (stage VIII) or in transit through the seminiferous epithelium showed no hybridization; sense probes showed no localization to residual bodies. A common feature of the probes which localized to the basal RBs was that they had been prepared using cDNA cloned into Bluescript SK- vector such that the antisense strand was generated from the T7 polymerase promotor. A cRNA prepared using T7 polymerase and Bluescript vector alone and a GC-rich 27mer oligonucleotide corresponding to the region of the multiple cloning site of Bluescript adjacent to the T7 site both localized uniquely to basal RB. It is concluded that the hybridization seen within RBs is probably a subtle artefact unique to RBs undergoing dissolution following fusion with Sertoli cell lysosomes, and may reflect nonspecific hybridization to GC-rich fragments of RNA.

Animals↗

Identification of up-regulated genes by array analysis in scrapie-infected mouse brains.

The major neuropathological features of the transmissible spongiform encephalopathies (TSEs) are well documented, however, the underlying molecular events are poorly defined. We have applied cDNA expression arrays and quantitative RT-PCR to the study of gene expression in the brain, and more specifically in the hippocampus, of the well-characterized ME7/CV mouse model of scrapie. The number of genes showing consistent, scrapie-associated changes in expression was limited, and was primarily restricted to glial-associated genes. Increased expression of genes encoding glial fibrillary acidic protein, vimentin, complement component 1q (alpha and beta polypeptides), cathepsin D, clusterin and cystatin C was evident in the hippocampus from 170 days after inoculation (dpi), with expression increasing thereafter to terminal disease (225-235 dpi). Elevation of gene expression preceded clinical disease by approximately 30 days, and coincided with a 20-day period in the ME7/CV model during which 50% of the CA1 hippocampal neurones are lost. Increased expression of cystatin C, an inhibitor of lysosomal cysteine proteases, is a novel finding in the context of TSE neuropathology and was confirmed by Western analysis and immunocytochemistry.

Animals↗

Renal dysfunction after total knee replacement is not aggravated by bone cement.

BACKGROUND: Total knee replacement (TKR) has been associated with postoperative renal dysfunction. The use of monomeric methylmethacrylate (MMA) bone cement causes hypotension by several mechanisms. METHODS: In 30 patients undergoing TKR with (n = 16), or without (n = 14) bone cement, serum levels of creatinine, cystatin C and creatine kinase (CK) and urinary levels of creatinine and markers for glomerular (albumin, IgG) and tubular (protein HC) function were recorded preoperatively and on days 1, 2, 4 and 8 postoperatively. RESULTS: There were no changes in serum creatinine. Both groups had a transient, 5-fold rise in CK and a continuous increase in cystatin C. The urinary concentration of proteins increased postoperatively with a peak in the glomerular markers on day 1 and in the tubular marker on day 2. There were no significant differences in proteinuria between the groups. The 95% CIs for the difference in the means of the AUCs of the logarithmically transformed values for the proteins were never more than 19%. On day 8 all proteins had returned to their preoperative levels. CONCLUSION: Postoperatively, there was a transient increased leakage of proteins, indicating glomerular and tubular dysfunction. This was not influenced by the use of MMA bone cement.

Aged↗