Volume 51 (2005) No. 3

Volume 51 (2005) No. 3

Original Articles
A 14-gene Region of Rat Chromosome 8 in SHR-Derived Polydactylous Congenic Substrain Affects Muscle-Specific Insulin Resistance, Dyslipidaemia and Visceral Adiposity
O. ŠEDA^_1,2, F. LIŠKA¹, L. ŠEDOVÁ¹, L. KAZDOVÁ², D. KŘENOVÁ¹, V. KŘEN¹....................................53
¹Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University, Prague, Czech Republic
²Department of Metabolism and Diabetes, Centre of Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
Corresponding author: Vladimír Křen, Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University, Prague, Albertov 4, 12800 Prague 2, Czech Republic. Tel.: (+420) 224 968 147; e-mail: vkren(zavináč)lf1.cuni.cz.
Abstract.
Full text. 53-61

Cytotoxicity and Apoptotic Effects of Microcystin-LR and Anatoxin-a in Mouse Lymphocytes
I. TENEVA¹, R. MLADENOV¹, N. POPOV², B. DZHAMBAZOV^{2, 3}...................................................62
¹Department of Botany, University of Plovdiv, Plovdiv, Bulgaria
²Cell Biology Laboratory, Department of Developmental Biology, University of Plovdiv, Plovdiv, Bulgaria
³Department of Experimental Medical Science, Division for Inflammation and Immunology, Lund University, Lund, Sweden
Corresponding author: Balik M. Dzhambazov, Department of Experimental Medical Science, Division for Inflammation and Immunology, BMC I 11, Lund University, 22184 Lund, Sweden. Tel.: ++46(46)222 3339; Fax: ++46(46)222 3110; e-mail: Balik.Dzhambazov@med.lu.se
Abstract.
Full text. 62-67

Evaluating the Karyotypic Diversity in Species of Hyla (Anura; Hylidae) with 2n = 30 Chromosomes Based on the Analysis of Ten Species
S. L. GRUBER¹, C. F. B. HADDAD², S. KASAHARA¹.......................................................................68
¹Departamento de Biologia, and ²Departamento de Zoologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Rio Claro, SP, Brasil
Corresponding author: Sanae Kasahara, Departamento de Biologia, Instituto de Biociências (UNESP), Av. 24 A, no 1515, 13506-900, Rio Claro, SP, Brasil. E-mail: kasahara@rc.unesp.br.
Abstract.
Full text. 68-75

Are the T/C Polymorphism of the CYP17 Gene and the Tetranucleotide Repeat (TTTA) Polymorphism of the CYP19 Gene Genetic Markers for Premature Coronary Artery Disease in Caucasians?
M. LETONJA¹, B. PETERLIN², D. BREGAR³, D. PETROVIČ³...........................................................76
¹Department of Internal Medicine, General Hospital of Ptuj, Ptuj, Slovenia
²Division of Medical Genetics, Department of Obstetrics and Gynecology, University Medical Centre, Ljubljana, Slovenia
³Institute of Histology and Embryology, Medical Faculty, University of Ljubljana, Ljubljana, Slovenia
Corresponding author: Daniel Petrovič, Institute of Histology and Embryology, Medical Faculty of Ljubljana, Korytkova 2, SI-1105 Ljubljana, Slovenia. Tel.: (+386) 1 543 7367; Fax: (+386) 1 543 7361; e-mail: daniel.petrovic@mf.uni-lj.si
Abstract.
Full text. 76-81

Short Communication
The Effect of Gemcitabine in the Treatment of Rejection in Experimental Small Intestine Transplantation
M. KUDLA, J. KŘÍŽ¹, D. JANOTOVÁ², P. GIRMAN¹, H. MERGENTAL, M. KOČÍK,
E. HONSOVÁ², M. ADAMEC......................................................................................82
Department of Transplant Surgery, ¹Centre of Diabetes, and ²Department of Pathology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
Corresponding author: Michal Kudla, Department of Transplant Surgery, Institute for Clinical and Experimental Medicine, Videňská 1958/9, 140 21 Prague 4, Czech Republic. Tel.: (+420) 261 364 105; Fax: (+420) 261 362 822; e-mail: michal.kudla@centrum.cz
Abstract.
Full text. 82-84

Original Articles

A 14-gene Region of Rat Chromosome 8 in SHR-Derived Polydactylous Congenic Substrain Affects Muscle-Specific Insulin Resistance, Dyslipidaemia and Visceral Adiposity
O. ŠEDA, F. LIŠKA, L. ŠEDOVÁ, L. KAZDOVÁ, D. KŘENOVÁ, V. KŘEN

The SHR and the PD/Cub are two established rodent models of human metabolic syndrome. Introgression of a ca 30 cM region of rat chromosome 8 from PD/Cub onto the genetic background of SHR was previously shown to influence several of the metabolic syndrome-related traits along with causing the PLS in the SHR-Lx congenic strain. In the process of identification of the causative alleles, we have produced several congenic sublines. The differential segment of SHR-Lx PD5 congenic substrain [SHR.PD(D8Rat42-D8Arb23)/Cub] spans approximately 1.4 Mb encompassing only 14 genes. When comparing the metabolic, morphometric and gene expression profiles of the SHR-Lx PD5 vs. SHR, the polydactyly and several distinct metabolic features observed in the original SHR-Lx congenic were still manifested, suggesting that the responsible genes were “trapped” within the relatively short differential segment of PD/Cub origin in SHR-Lx PD5. Particularly, the SHR-Lx PD5 displayed substantial reduction of insulin sensitivity confined to skeletal muscle. Among the candidate genes, the promyelocytic leukaemia zinc-finger Plzf (Zbtb16) transcription repressor is most likely responsible for the Lx mutation resulting in PLS and could also be involved in the alteration of metabolic pathways. The sequence analysis of the Plzf gene revealed a SNP leading to a threonine to serine substitution in SHR at aminoacid position 208 (T208S). In summary, we have isolated a 1.4 Mb genomic region syntenic to human chromosome 11q23, which, apart from causing PLS, affects total body weight, adiposity, lipid profile, insulin sensitivity of skeletal muscle and related gene expression as shown in the SHR-Lx PD5 congenic substrain.
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Cytotoxicity and Apoptotic Effects of Microcystin-LR and Anatoxin-a in Mouse Lymphocytes
I. TENEVA, R. MLADENOV, N. POPOV, B. DZHAMBAZOV

There is an increasing amount of knowledge on the cytotoxic properties of cyanotoxins, but relatively little is known regarding their fine specificity and mechanisms of action. In this study, we investigated the influence of microcystin-LR and AnTx-a on mouse B- and T-lymphocyte subpopulations in vitro. Cyanotoxins significantly decreased the cell viability after 4 and 24 h, compared to the untreated control. After 24 h exposure to microcystin-LR and anatoxin-a, the viability of splenocytes dropped to 23% and 57%, respectively. Our data demonstrate that microcystin-LR induces apoptosis specifically in mouse B cells, probably via the B-cell antigen receptor and mitochondrial pathway, while the T cells were not affected. AnTx-a showed cytotoxic effects on both lymphocyte subpopulations, but the effects were driven by mechanisms different from apoptosis. These findings demonstrate that the cyanotoxins could cause cytotoxic alterations in a variety of cell types different from the major targets, operating via distinct mechanisms.

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Evaluating the Karyotypic Diversity in Species of Hyla (Anura; Hylidae) with 2n = 30 Chromosomes Based on the Analysis of Ten Species
S. L. GRUBER, C. F. B. HADDAD, S. KASAHARA

Ten species of Hyla with 2n = 30 from Brazilian fauna were analysed cytogenetically. Hyla minuta is the unique presenting all bi-armed metacentric or submetacentric chromosomes in the karyotype, therefore, with the highest FN = 60. The remaining species have a variable number of uni-armed telocentric or subtelocentric chromosomes: H. cruzi, H. elianeae, and H. rubicundula with three pairs (FN = 54), H. berthalutzae, H. elegans, H. microps, and H. nana with four pairs (FN = 52), and H. nahdereri and H. sanborni with five pairs (FN = 50). The uni-armed elements are among pairs 5, 6, 7, 11, 14, and 15, which also appeared with metacentric or submetacentric morphology. The remaining chromosome pairs 1, 2, 3, 4, 8, 9, 10, 12, and 13 were never found to be telocentric or subtelocentric. AgNOR patterns are species-specific, the majority of the species exhibiting a single pair with AgNORs, with the exception of H. elegans and H. nana with more than one chromosome pair bearing this cytological marker. C banding was obtained in H. berthalutzae, H. cruzi, H. elegans, H. elianeae, H. microps, H. minuta, H. nahdereri, and H. nana, which showed positively stained centromeric heterochromatin. Our analysis confirms the great karyotypic diversity in the species of Hyla with 2n = 30, with no species sharing identical karyotypes.
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Gender differences in CAD have been clearly documented, and sex hormones have been recognized to influence the risk of CAD. The cytochrome P450c17 gene (CYP17) and the CYP19 gene influence concentrations of sex hormones. In this cross-sectional association study we tested the hypothesis whether the T/C polymorphism of the CYP17 gene and the tetranucleotide repeat (TTTA) polymorphism of the CYP19 gene are genetic markers for CAD in Caucasians. The TT genotype of the CYP17 gene polymorphism was not associated with premature CAD in men and women combined (OR 0.9; 95% CI = 0.6–1.4; P = 0.7), in men only (OR 1; 95% CI = 0.6–1.8; P = 0.7), and in women only (OR 0.8; 95% CI = 0.5–1.4; P = 0.4). The tetranucleotide repeat (TTTA) CYP19 gene polymorphism was not associated with premature CAD. Moreover, the genotypes containing the longer alleles (A6 or A7) were not associated with a lower incidence of CAD, and the genotypes containing the shorter alleles (A1 or A2) were not over-represented in the CAD patients. We may conclude that in Caucasian subjects neither the T/C CYP17 gene polymorphism nor the tetranucleotide repeat (TTTA) polymorphism of the CYP19 gene contributes to the genetic susceptibility to CAD, therefore they may not be used as genetic markers for CAD risk assessment.
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Short Communication

The Effect of Gemcitabine in the Treatment of Rejection in Experimental Small Intestine Transplantation
M. KUDLA, J. KŘÍŽ, D. JANOTOVÁ, P. GIRMAN, H. MERGENTAL, M. KOČÍK,
E. HONSOVÁ, M. ADAMEC

The aim of our study was to test the immunosuppressive effect of gemcitabine in monotherapy following heterotopic SBT in the rat. The BN and LEW rats were used as donors and recipients, respectively. Recipients were divided into 4 groups - group A without immunosuppression, group B treated with a therapeutic dose of tacrolimus, groups C and D treated with various doses of gemcitabine (100 and 150 microg/kg/day). Immunosuppression was administered once a day for 7 days after SBT, when the animals were sacrificed and a histological examination of grafts was performed. Only in group B no signs of acute rejection were seen. Significant differences (P < 0.01) were noted only between group B versus groups A, C, and D. No significant differences were demonstrated between groups A versus groups C, D and between group C versus group D. Monotherapy by gemcitabine (when administered at given doses) was not shown to be effective in preventing acute rejection in a rat model of heterotopic SBT.
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