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1.
Radiat Environ Biophys ; 58(3): 449-454, 2019 08.
Article in English | MEDLINE | ID: mdl-31222610

ABSTRACT

Testing the limits of survivability in space is the primary focus in astrobiological research. Although a number of previous studies have examined terrestrial life survival in an extraterrestrial environment, only a few have investigated how life systems respond to high doses of alpha cosmic ray, the main component of cosmic rays. We used respiration and photosynthetic rates as indicators of the vital signs of the lichen Caloplaca flavovirescens, which is a symbiotic life form including fungi and algae. Our experiment demonstrated that the photosynthetic rate decreased with increased helium-beam doses, whereas the respiration rate was relatively unaffected. Specifically, under a helium-beam dose greater than 10Ā Gy, the respiration rate remained nearly constant regardless of further increases in the radiation rate. Our results indicate that the different metabolic systems of terrestrial life forms might exhibit different survival characteristics when they are in space.


Subject(s)
Cosmic Radiation , Dose-Response Relationship, Radiation , Lichens/radiation effects , Exobiology , Extraterrestrial Environment , Helium , Lichens/physiology , Photosynthesis , Physical Phenomena
2.
Clin Exp Dermatol ; 43(2): 175-179, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29271496

ABSTRACT

Pseudoxanthoma elasticum (PXE) is a disease characterized by aberrant mineralization of soft tissue and fragmentation of elastic fibres. It is often difficult to distinguish PXE clinically from pseudoxanthoma elasticum-like papillary dermal elastolysis (PXE-like PDE). However, we have identified that the dermoscopic findings in PXE include coalescing and reticulated yellow-white clods on a light purple-red background, whereas the dermoscopic findings in PXE-like PDE lack such a coloured background. To our knowledge, this is the first detailed description of dermoscopic differences between PXE and PXE-like PDE.


Subject(s)
Dermis/pathology , Elastic Tissue/pathology , Pseudoxanthoma Elasticum/diagnosis , Aged , Dermoscopy , Diagnosis, Differential , Female , Humans , Male , Pseudoxanthoma Elasticum/pathology , Skin/pathology
3.
Pediatr Surg Int ; 31(10): 955-62, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26319695

ABSTRACT

AIM: To discuss the chronological changes observed in a national survey of neonatal surgery in Japan performed every 5 years by the Committee in the Japanese Society of Pediatric Surgeons. METHODS: We analyzed the data obtained for 20 years from 1993 to 2013 and herein report the chronological changes. RESULTS: The number of summarized cases was least in 1993, with 2806 cases, and subsequently increased to 3753 cases in 2013. The mortality rate among the patients with maternal transport linearly decreased (p = 0.0386). Although the proportion of extremely low birth weight infants linearly increased (p = 0.0014), with an annual rate of +0.39 %, the mortality rate linearly decreased (p = 0.0010), with an annual rate of -1.68 %. Moreover, the overall mortality rate linearly decreased (p = 0.0002), with an annual rate of -0.26 %. Most diseases were observed to exhibit a decline in the mortality rate with the same trend as overall mortality. The decline in the mortality rate was most robust with respect to congenital diaphragmatic hernia (CDH). The mortality rates, except for that of CDH, omphalocele, esophageal atresia, and intestinal perforation, declined to 5 % or lower by 2013. CONCLUSIONS: The present findings may be the result of remarkable progress in perinatal management.


Subject(s)
Congenital Abnormalities/surgery , Health Care Surveys/statistics & numerical data , Surgical Procedures, Operative/statistics & numerical data , Female , Humans , Infant, Newborn , Japan , Male
4.
Nat Genet ; 4(3): 300-4, 1993 Jul.
Article in English | MEDLINE | ID: mdl-8358439

ABSTRACT

Machado-Joseph disease (MJD) is an autosomal dominant, multisystem neurodegenerative disorder involving predominantly cerebellar, pyramidal, extrapyramidal, motor neuron and oculomotor systems. Although it was first reported in families of Portuguese-Azorean descent, MJD has also been described in non-Azorean families from various countries, being one of the most common hereditary spinocerebellar degenerations. With the use of highly polymorphic microsatellite DNA polymorphisms, we have assigned the gene for MJD to the long arm of chromosome 14 (14q24.3-q32) by genetic linkage to microsatellite loci D14S55 and D14S48 (multipoint lod score Zmax = 9.719).


Subject(s)
Chromosomes, Human, Pair 14 , Spinocerebellar Degenerations/genetics , Chromosome Mapping , DNA, Satellite/genetics , Female , Genetic Linkage , Genetic Markers , Humans , Linkage Disequilibrium , Male , Pedigree , Polymorphism, Genetic
5.
ACS Cent Sci ; 6(2): 283-292, 2020 Feb 26.
Article in English | MEDLINE | ID: mdl-32123747

ABSTRACT

Phosphorylation of alcohols is a fundamentally important reaction in both life science and physical science. Product phosphate monoesters play key roles in living organisms, natural products, pharmaceuticals, and organic materials. Most of the chemical methods to date for synthesizing phosphate monoesters, however, require multistep sequences or are limited to specific types of substrates possibly due to harsh conditions. An alternative way to enable the simple production of phosphate monoesters from highly functionalized precursor alcohols is, thus, highly desired. We report herein a catalytic phosphorylation of alcohols with high functional group tolerance using tetrabutylammonium hydrogen sulfate (TBAHS) and phosphoenolpyruvic acid monopotassium salt (PEP-K) as the catalyst and phosphoryl donor, respectively. This method enables the direct introduction of a nonprotected phosphate group to the hydroxy group of a diverse menu of alcohol substrates, including functionalized small molecules, carbohydrates, and unprotected peptides. Nuclear magnetic resonance, mass spectrometric, and density functional theory analyses suggest that an unprecedented mixed anhydride species, generated from PEP-K and TBAHS, acts as an active phosphoryl donor in this reaction. This operationally simple and chemoselective catalytic phosphorylation allows for the efficient production of densely functionalized O-phosphorylated compounds, which are useful in diverse fields including biology and medicine.

6.
Oper Dent ; 44(4): 336-347, 2019.
Article in English | MEDLINE | ID: mdl-30444691

ABSTRACT

The study aimed to histologically evaluate wound healing of exposed human pulp on direct pulp capping using super-pulsed CO2 laser preirradiation. In this single-blind clinical trial, 28 third molar teeth of 17 volunteers were randomly capped with either CO2 laser irradiation (n=14) or Dycal (calcium hydroxide cement; n=14) and restored using resin composite. The laser was operated in super-pulsed mode (pulse duration, 0.2 ms; interval, 5.8 ms; 0.003 J/pulse). The irradiation conditions were a power output of 0.5 W, an irradiation time of 15 seconds, repeat mode (10-ms irradiation and 10-ms intervals, for a total beam exposure time of 7.5 seconds), total applied energy of 3.75 J, and an activated air-cooling system. Each tooth was extracted at six or 12 months posttreatment and prepared for histological evaluation. We evaluated the parameters of pulp tissue disorganization, inflammatory cell infiltration, reparative dentin formation (RDF), and bacterial penetration. There were no significant differences between groups for all parameters at each postoperative period (Mann-Whitney U-test, p>0.05). CO2 laser irradiation completely controlled bleeding and exudate from the exposed pulp. The CO2 laser group had a tendency to delay RDF compared with the Dycal group, but 4 of 7 teeth from the CO2 laser group showed a complete dentin bridge at 12 months posttreatment.


Subject(s)
Dental Pulp Capping , Dentin, Secondary , Carbon Dioxide , Dental Pulp , Humans , Resin Cements , Single-Blind Method
7.
Neuron ; 14(2): 457-66, 1995 Feb.
Article in English | MEDLINE | ID: mdl-7857653

ABSTRACT

We analyzed an amino-terminal modification of beta-amyloid (A beta) peptide in brain, using anti-A beta antibodies that distinguish distinct molecular species. Examination of cortical sections from 28 aged individuals with a wide range in senile plaque density revealed that a molecular species distinct from the standard A beta is deposited in the brain in a dominant and differential manner. This modified A beta peptide (A beta N3(pE)) starts at the 3rd aminoterminal residue of the standard A beta, glutamate, converted to pyroglutamate through intramolecular dehydration. Because plaques composed of A beta N3(pE) are present in equivalent or greater densities than those composed of standard A beta bearing the first amino-terminal residue (A beta N1) and because deposition of the former species appears to precede deposition of the latter, as confirmed with specimens from Down's syndrome patients, the processes involved in A beta N3(pE) production and retention may play an early and critical role in senile plaque formation.


Subject(s)
Alzheimer Disease/pathology , Amyloid beta-Peptides/analysis , Brain/pathology , Down Syndrome/pathology , Adult , Aged , Aged, 80 and over , Amino Acid Sequence , Antibodies , Antibody Specificity , Female , Humans , Immune Sera , Male , Middle Aged , Molecular Sequence Data , Oligopeptides/chemical synthesis , Oligopeptides/immunology , Organ Specificity
8.
J Int Med Res ; 36(5): 1117-22, 2008.
Article in English | MEDLINE | ID: mdl-18831909

ABSTRACT

Tokushima University Hospital has established the Tokushima Network for Clinical Trials (TNCT) to promote clinical trials in the area in collaboration with the Tokushima Medical Association. The present study investigated the views of doctors towards registration trials in the TNCT. A questionnaire was provided to 49 clinics/hospitals registered to the TNCT in 2006 and 38 (78%) responded. It revealed that 48% of doctors were aware of registration trials and 87% were favourable towards participating as investigators in them. They considered close contact with developmental drugs, advancement of therapy and the opportunity to learn about state-of-the-art treatment as benefits of participation. The main areas of difficulty included management of adverse reactions and patients' refusal to take part. Many doctors wanted more opportunity to learn about trial-related issues such as regulations. The survey indicates that the TNCT needs to develop the infrastructure and enlighten participants to promote registration trials in this rural regional area.


Subject(s)
Attitude of Health Personnel , Clinical Trials as Topic , Data Collection , Informed Consent , Physicians/psychology , Rural Population , Drug Approval , Hospitals, University , Humans , Surveys and Questionnaires
9.
Br Poult Sci ; 49(3): 273-81, 2008 May.
Article in English | MEDLINE | ID: mdl-18568751

ABSTRACT

1. Inter-breed morphological comparisons were made among 11 breeds of Japanese native chickens (Gifujidori, Hinaidori, Shokoku, Totenko, Tomaru, Satsumadori, Shamo, Koshamo, Koeyoshi, Chabo and Nagoya), White Leghorn, broiler chickens (Chunky) and red junglefowl collected in the Philippines, based on results of direct measurements and analysis by computer vision techniques of the skull. 2. Analysis of direct measurements identified two groups of chicken: a small type that included the Chabo, Koshamo, red junglefowl, Gifujidori and Shokoku and a large type that included the remaining breeds studied. These groupings were made based on size determined both in the first (PC1) and second principal component (PC2). The greatest length of the cranium and condylobasal length greatly contributed to the morphological differences between these two groups. 3. Analysis by computer vision techniques, however, identified three groups: the Bantam group (which includes red junglefowl), Shokoku group and Shamo group. White Leghorn clustered within the Shokoku group while the broiler chicken belonged to the Shamo group. The region around the junction of the neural cranium and the visceral cranium contributed greatly to the morphological differences among breeds, both in the PC1 and PC2.


Subject(s)
Chickens/anatomy & histology , Chickens/genetics , Skull/anatomy & histology , Animals , Chickens/classification , Computer Graphics , Computer Simulation , Female , Genetic Variation , Japan , Male , Phylogeny , Species Specificity
10.
J Clin Invest ; 102(12): 2061-71, 1998 Dec 15.
Article in English | MEDLINE | ID: mdl-9854041

ABSTRACT

Nitric oxide (NO), constitutively produced by endothelial nitric oxide synthase (eNOS), plays a major role in the regulation of blood pressure and vascular tone. We generated transgenic mice overexpressing bovine eNOS in the vascular wall using murine preproendothelin-1 promoter. In transgenic lineages with three to eight transgene copies, bovine eNOS-specific mRNA, protein expression in the particulate fractions, and calcium-dependent NOS activity were confirmed by RNase protection assay, immunoblotting, and L-arginine/citrulline conversion. Immunohistochemical studies revealed that eNOS protein was predominantly localized in the endothelial cells of aorta, heart, and lung. Blood pressure was significantly lower in eNOS-overexpressing mice than in control littermates. In the transgenic aorta, basal NO release (estimated by Nomega-nitro-L-arginine-induced facilitation of the contraction by prostaglandin F2alpha) and basal cGMP levels (measured by enzyme immunoassay) were significantly increased. In contrast, relaxations of transgenic aorta in response to acetylcholine and sodium nitroprusside were significantly attenuated, and the reduced vascular reactivity was associated with reduced response of cGMP elevation to these agents as compared with control aortas. Thus, our novel mouse model of chronic eNOS overexpression demonstrates that, in addition to the essential role of eNOS in blood pressure regulation, tonic NO release by eNOS in the endothelium induces the reduced vascular reactivity to NO-mediated vasodilators, providing several insights into the pathogenesis of nitrate tolerance.


Subject(s)
Hypotension/genetics , Nitric Oxide Synthase/genetics , Nitric Oxide/pharmacology , Vasodilation/drug effects , Animals , Aorta/cytology , Aorta/enzymology , Blood Pressure/genetics , Cattle , Cyclic GMP/metabolism , Disease Models, Animal , Gene Expression Regulation/genetics , Immunohistochemistry , Lung/cytology , Lung/enzymology , Mice , Mice, Transgenic , Muscle Contraction/drug effects , Muscle Relaxation/drug effects , Myocardium/cytology , Myocardium/enzymology , Nitroarginine/pharmacology , Phenotype , Promoter Regions, Genetic/genetics , RNA, Messenger/genetics
12.
Cancer Res ; 55(17): 3897-901, 1995 Sep 01.
Article in English | MEDLINE | ID: mdl-7641209

ABSTRACT

Thymidylate synthase (TS) is a target enzyme of 5-fluorouracil and is inhibited by 5-fluoro-dUMP (FdUMP) to form an inactive ternary complex. We investigated the changes in the number of FdUMP binding sites in human colorectal carcinoma tissues after treatment with 5-fluorouracil derivatives and also examined the mechanisms underlying these changes. The number of FdUMP binding sites was significantly increased in patients who received tegafur and uracil preoperatively [UFT (+) group, n = 14] compared with those who did not [UFT (-) group, n = 36; P < 0.0001]. No amplification of the TS gene was observed in the carcinoma tissues in either group. The level of TS mRNA in the carcinoma tissues showed no significant difference between UFT (-) and UFT (+) groups. There was a significant correlation between the level of TS mRNA and TS in the UFT (-) group, as shown by simple linear regression analysis (P < 0.05). In the UFT (+) group, 9 of 12 cases showed TSf corresponding to their level of TS mRNA. It seemed that the augmentation of TStot is the result of accumulation of ternary complex. Thus, TS inhibition by FdUMP will be insufficient in the absence of methylenetetrahydrofolate in the cytosol, because translation of TS from TS mRNA has been shown to continue in the presence of FdUMP.


Subject(s)
Colorectal Neoplasms/chemistry , Fluorodeoxyuridylate , Tegafur/pharmacology , Thymidylate Synthase/analysis , Uracil/pharmacology , Base Sequence , Binding Sites/drug effects , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Humans , Molecular Sequence Data , RNA, Messenger/analysis , Tetrahydrofolates/analysis , Thymidylate Synthase/drug effects , Thymidylate Synthase/genetics
13.
Oncogene ; 16(23): 3029-37, 1998 Jun 11.
Article in English | MEDLINE | ID: mdl-9662336

ABSTRACT

The Fas system has been extensively investigated as a model of apoptosis and the caspase cascade has been shown to be a characteristic mechanism of signaling of apoptosis. We have identified and purified a kinase that was activated after the stimulation of Fas on human thymoma-derived HPB-ALL cells. Partial amino acid sequencing of the purified kinase revealed it to be MST/Krs, member of the yeast STE20 family of protein kinases. MST/Krs was activated by proteolytic cleavage and proteolytic activation was blocked by the caspase inhibitor, Z-VAD-FK. A mutant MST with Asp-->Asn replacement at a putative caspase cleavage site was resistant to either the proteolytic cleavage or the activation of the kinase activity. These findings suggest that proteolytic activation is one activation mechanism of MST and plays a role in apoptosis.


Subject(s)
Apoptosis , Cysteine Endopeptidases/metabolism , Cysteine Proteinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/metabolism , Saccharomyces cerevisiae Proteins , Amino Acid Sequence , Enzyme Activation , Humans , Intracellular Signaling Peptides and Proteins , MAP Kinase Kinase Kinases , Molecular Sequence Data , Protein Serine-Threonine Kinases/genetics , Serine-Threonine Kinase 3 , Tumor Cells, Cultured , fas Receptor/metabolism
14.
Biochim Biophys Acta ; 1235(1): 107-14, 1995 Apr 12.
Article in English | MEDLINE | ID: mdl-7718599

ABSTRACT

In order to confirm whether the binding sites for mu-calpain on the inner surface of erythrocyte membranes are substrate proteins themselves, we examined the binding properties of mu-calpain to mu-calpain-pretreated inside-out membranes. When native mu-calpain was incubated with mu-calpain-pretreated membranes, however, newly added calpain was degraded rapidly in a time- and Ca(2+)-dependent manner. Although the degradation of mu-calpain was not inhibited by various proteinase inhibitors, it was strongly inhibited by digestible substrates for calpain that possess the ability to inhibit the binding of mu-calpain to erythrocyte membranes. On the other hand, when mu-calpain inactivated by N-ethylmaleimide was incubated with mu-calpain-pretreated membranes, no degradation was observed. These results indicate that the degradation of mu-calpain occurs on the surface of mu-calpain-modified membranes and that it depends on the autoproteolytic activity of mu-calpain itself. It seems likely that the autoproteolytic activity of mu-calpain is accelerated markedly by some component(s) exposed on the surface of membranes during the pretreatment with mu-calpain. The possibility is thus proposed that cell membranes possess the ability to down-regulate calpain to protect cell membranes from overdegradation by excessively bound calpain. The active factor(s) in the membranes that can accelerate the autoproteolytic degradation of mu-calpain could be almost completely removed from mu-calpain-modified membranes by treatment with Triton X-100.


Subject(s)
Calpain/metabolism , Erythrocyte Membrane/metabolism , Animals , Down-Regulation , Ethylmaleimide/metabolism , Female , Humans , Hydrolysis , Membrane Proteins/metabolism , Mice , Mice, Inbred BALB C , Phospholipids/metabolism , Protein Binding , Rabbits
15.
Biochim Biophys Acta ; 1182(2): 215-20, 1993 Sep 08.
Article in English | MEDLINE | ID: mdl-8357852

ABSTRACT

To examine whether calpain is activated during ischemic or reperfusion injury, we measured calpain activity of the subfractions of rat myocardia after global ischemia for 60 min or the ischemia followed by 30 min reperfusion by the Langendorff procedure. The myocardial homogenate was fractionated into 600 x g, 10,000 x g and 100,000 x g pellet fractions as well as 10,000 x g supernatant fraction. The supernatant fraction was further subjected to DEAE cellulose and phenyl-Sepharose chromatographies to separate mu- and m-calpains. The m-calpain activity of the DEAE fractions after global ischemia for 60 min was higher but that after ischemia-reperfusion was lower than that of the control. On the other hand, the ischemia-reperfusion but not ischemia by itself raised the calpain activity of the phenyl-Sepharose fraction (mu-calpain) and the 10,000 x g pellet measured at 100 microM and 5 mM Ca2+. Treatment with verapamil but not with ryanodine during ischemia attenuated the increase in m-calpain activity. A dot-blotting analysis of calpain antigenicity showed a decrease in soluble but no change in the particulate fractions after ischemia-reperfusion. An immunoblotting technique did not detect proteolysis of the calpain 80-kDa subunit. These observations suggest that calpain is activated by Ca2+ influx during ischemia and reperfusion without gross changes in its amount. Some unknown processes other than translocation or autolysis are thought to be involved in the alterations.


Subject(s)
Calpain/metabolism , Coronary Disease/metabolism , Myocardium/metabolism , Animals , Calpain/isolation & purification , Male , Myocardial Reperfusion , Proteins/analysis , Rats , Rats, Wistar , Ryanodine/pharmacology , Subcellular Fractions/chemistry , Verapamil/pharmacology
16.
Biochim Biophys Acta ; 985(1): 51-4, 1989 Oct 02.
Article in English | MEDLINE | ID: mdl-2551388

ABSTRACT

The location of calcium-activated neutral proteinase (CANP) was determined in human erythrocytes by crosslinking CANP to co-localizing proteins using a photolabeling bifunctional reagent, 4,4'-dithiobisphenylazide (DTBPA). The crosslinked products were selectively isolated by immunoprecipitation with a polyclonal anti-CANP antibody and analyzed by SDS-polyacrylamide gel electrophoresis after cleavage of the crosslinkage. In the calcium-free incubation medium the main proteins crosslinked with CANP were cytosolic proteins such as hemoglobin. In the presence of calcium ions, on the other hand, membrane skeletal proteins such as spectrin, band 4.1, 4.2 and 6 proteins as well as band 3 were crosslinked with CANP. Addition of calcium ionophore further increased the amount of crosslinked membrane proteins. These results suggest that in the absence of calcium ions CANP exists diffusely in the cytoplasm and is crosslinked with cytoplasmic hemoglobin nonspecifically while in the presence of calcium ions CANP associated with membrane where it is crosslinked specifically with the lining proteins. Thus it is demonstrated biochemically that the localization of CANP is dynamic depending on the presence of calcium ions.


Subject(s)
Calcium/pharmacology , Calpain/metabolism , Erythrocyte Membrane/enzymology , Calcimycin/pharmacology , Cross-Linking Reagents , Electrophoresis, Polyacrylamide Gel , Erythrocyte Membrane/drug effects , Humans
17.
Biochim Biophys Acta ; 965(2-3): 130-5, 1988 May 12.
Article in English | MEDLINE | ID: mdl-2835111

ABSTRACT

A simple separation method involving a minimum number of essential steps was established to separate the two kinds of calcium-activated neutral proteinase (CANP) activity from each other and from endogenous CANP inhibitor activity. Determination of CANP activity in rat tissues using this method revealed a ubiquitous distribution of two CANPs. The level of CANP activity, however, differs between tissues. Low-calcium-requiring CANP (microCANP) is plentiful in spleen and kidney, while high-calcium-requiring CANP (mCANP) is plentiful in lung and brain. In all of the tissues examined, mCANP activity predominates over microCANP activity.


Subject(s)
Calpain/metabolism , Animals , Calcium/pharmacology , Calpain/isolation & purification , Electrophoresis, Polyacrylamide Gel , Immunoassay , Kidney/enzymology , Lung/enzymology , Rabbits , Rats , Spleen/enzymology , Tissue Distribution
18.
Biochim Biophys Acta ; 1094(3): 249-56, 1991 Sep 24.
Article in English | MEDLINE | ID: mdl-1911875

ABSTRACT

Intracellular calcium-activated neutral proteinase (CANP) in rabbit erythrocytes was activated by an influx of Ca2+ into the cells. The catalytic large subunit changed from the original 79 kDa from to the 77 kDa and 76 kDa forms on activation just in the same manner as occurs in the autolytic activation of purified CANP in vitro. The activation required both extracellular Ca2+ and A23187, and was accompanied by the degradation of some membrane proteins and morphological changes in erythrocyte shape from discocytes to echinodisks, echinocytes, and spherocytes. Exogenously added Cbz-Leu-Leu-Leu-aldehyde inhibited the activation of intracellular CANP as well as the degradation of membrane proteins and the morphological changes indicating that the latter two processes are due to the action of CANP. Leupeptin and E64d were without effect on intracellular CANP.


Subject(s)
Calpain/metabolism , Erythrocytes/enzymology , Amino Acid Sequence , Animals , Antibodies, Monoclonal , Blood Proteins/metabolism , Calcimycin/pharmacology , Calcium/pharmacology , Calpain/antagonists & inhibitors , Enzyme Activation , Erythrocytes/cytology , Female , In Vitro Techniques , Leucine/analogs & derivatives , Leucine/pharmacology , Leupeptins/pharmacology , Membrane Proteins/metabolism , Mice , Mice, Inbred BALB C , Molecular Sequence Data , Rabbits
19.
Biochim Biophys Acta ; 1178(2): 207-14, 1993 Aug 18.
Article in English | MEDLINE | ID: mdl-8347679

ABSTRACT

Calpain and its endogenous inhibitor, calpastatin, were isolated from erythrocytes of various mammals and their properties were compared. It has been widely believed that mammalian erythrocytes contain only mu-calpain. However, rat and human erythrocytes were found to contain two species of calpain, identified as mu-calpain and m-calpain from their elution positions on DEAE-cellulose column chromatography and their Ca(2+)-requirements. Thus, it is apparent that rat and human erythrocytes contain not only mu-calpain, but m-calpain as well. On the other hand, rabbit erythrocytes contain only mu-calpain. Western blot analysis showed that human and rabbit erythrocytes contain predominantly 70-kDa calpastatin (erythrocyte-type), but unnegligible amounts of 110-kDa calpastatin (tissue-type) are also present. Rat erythrocytes were shown to contain a calpastatin with a molecular mass of approx. 100 kDa almost exclusively; this molecular mass was in perfect coincidence with the mass of the calpastatin in rat lung. These results strongly suggest that rat erythrocytes contain a tissue-type calpastatin. No essential change in the calpain/calpastatin system during maturation of rabbit reticulocytes into mature erythrocytes was observed.


Subject(s)
Calcium-Binding Proteins/blood , Calpain/blood , Erythrocytes/metabolism , Animals , Blotting, Western , Calcium-Binding Proteins/isolation & purification , Calpain/isolation & purification , Cell Differentiation/physiology , Chromatography, DEAE-Cellulose , Erythrocytes/chemistry , Erythrocytes/enzymology , Humans , Rabbits , Rats , Rats, Wistar , Reticulocytes/metabolism , Species Specificity
20.
Biochim Biophys Acta ; 1362(1): 11-23, 1997 Nov 28.
Article in English | MEDLINE | ID: mdl-9434095

ABSTRACT

The Shumiya cataract rat (SCR) is a hereditary cataract model in which lens opacity appears spontaneously in the nuclear and perinuclear portions at 11-12 weeks of age. It was found that the proteolysis of some crystallins and cytoskeletal proteins is significantly enhanced in cataractous SCR lenses. The calcium concentrations in cataractous lenses rise markedly with age as compared with control lenses and the autolytic product of calpain is also detected in cataractous lenses. In order to provide direct evidence for the involvement of calpain in the proteolytic modification of lens proteins, we developed antibodies exclusively specific to the proteolytic products of some lens proteins produced by the action of calpain and analyzed their degradation during cataractogenesis in SCR by Western blotting and immunohistochemical staining. The results demonstrate that calpain participates in the proteolytic modification of lens proteins, at least alpha-crystallin (A and B chain), betaB1-crystallin, and alpha-fodrin. The proteolytic products formed by the action of calpain on these proteins are detected in cataractous lenses of SCR as young as 8 weeks of age and accumulate with age. It was also found that betaB1-crystallin, originally a soluble protein, is converted to an insoluble form by limited calpain proteolysis. The chaperon-like activity of alpha-crystallin from control lens is markedly reduced by calpain proteolysis in vitro, and alpha-crystallin in opaque lens that has already undergone proteolysis by calpain shows significantly reduced chaperon-like activity. Immunohistochemical studies reveal that the area where the calpain-mediated alpha-crystallin proteolysis is in progress coincides well with the area developing and destined to develop the opacification. These results strongly suggest that calpain may contribute to lens opacification during cataract formation in SCR.


Subject(s)
Calpain/physiology , Cataract/metabolism , Lens, Crystalline/metabolism , Aging , Amino Acid Sequence , Animals , Antibodies, Monoclonal , Calcium/metabolism , Carrier Proteins/metabolism , Cataract/genetics , Cattle , Crystallins/metabolism , Microfilament Proteins/metabolism , Molecular Chaperones/metabolism , Molecular Sequence Data , Peptide Fragments/analysis , Rats , Rats, Inbred Strains
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