- Email: [email protected]
Effect of Aβ expression on development of learning deficits in APP-transgenic mice
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ABSTRACTS / Developmental Biology 306 (2007) 323–328
et al., 2007, Histology and Histopathology, 22: in press) revealed Ctgf down-regulation in the hypoplastic lungs of mouse embryos that completely lacked skeletal muscle and in turn fetal breathing-like movements (FBMs). Therefore, the current report examines pulmonary development of Ctgf−/− mouse fetuses (kindly provided by Dr. Karen M. Lyons) and the possibility of CTGF involvement in the pathogenesis of lung hypoplasia. The Ctgf−/− lungs are hypoplastic, with reduced cell proliferation and increased apoptosis. PDGF-B, its receptor and IGF-I are markedly attenuated, while the TTF-1 gradient is lost. Type II pneumocyte differentiation is perturbed, with the cells depicting excessive glycogen retention and diminished lamellar body size, though able to synthesize surfactantassociated protein. However, type I pneumocyte differentiation is not affected by Ctgf deletion. Our findings indicate that the absence of Ctgf and/or its protein product, CTGF, may induce pulmonary hypoplasia by disrupting basic lung developmental processes. Supported by NSERC, CIHR, LANS, CFI and DMRF to BK. doi:10.1016/j.ydbio.2007.03.144
Program/Abstract # 89 Dll3-Notch1 signaling: Functional genomic analysis of downstream genes & genetic interactions modeling vertebral defects William Sewell 1, Allanceson Smith 1, Kathleen M. Loomes 2, Stacey A. Stevens 3, Megan L. O'Brien 3, Dorian M. Gonzalez 3, J. Ryan 3, Eric F. Rappaport 3 1 School Life Sciences, Arizona State Univ, Tempe AZ, USA 2 Div Gastroenterology & Nutrition, Children’s Hosp Philadelphia PA, USA 3 Div Human Genetics & Orthopaedic Surgery, Children’s Hosp Philadelphia PA, USA 4 Dept Pediatrics, Univ Penn School Med, Philadelphia PA, USA 5 Victor Chang Cardiac Res Inst, Sydney & Faculties Med Sciences, Univ New South Wales, Kensington, Australia 6 Dept Basic Med Sciences, Univ Arizona College Med, Phoenix AZ, USA Mutations in the Notch1 receptor and Dll3 ligand disrupt somitogenesis and vertebral patterning. Previous studies have shown that genetic interactions among members of the notch pathway cause defects not observed in single gene mutations. To examine Dll3–Notch genetic interactions, we generated compound mouse mutants and screened for skeletal malformations and histological anomalies. While Dll3tm1Rbe or Notch1tm1Con heterozygous mice appeared normal, 30% of double heterozygous animals displayed segmental malformations similar to those in birth defects such as congenital scoliosis. Developmental analysis of somite-stage embryos and perinatal organs did not reveal any defects. To identify potential disruptions earlier in development, we used microarray analysis of Dll3 and Notch1 homozygous 9.5 dpc embryos, and we are investigating
genes such as brachyury and Hoxb8 that display greater than 2fold changes in expression. These findings have identified that Dll3–Notch1 double heterozygous mutants may be a useful model to study the etiology of human congenital scoliosis and vertebral birth defects. doi:10.1016/j.ydbio.2007.03.145
Program/Abstract # 90 The vacuolar-ATPase complex is required for the survival of retinal and RPE cells in the zebrafish eye Jeffrey M. Gross, Richard Nuckels MCDB Dept., Univ. Texas at Austin In a retrovirus-based insertional mutagenesis screen, we identified six recessive zebrafish mutants that presented with pigmentation deficits and severe degeneration of the retina and RPE. Each of the mutations disrupted a distinct subunit of the vacuolar-ATPase complex (v-ATPase), or proteins that associate with the v-ATPase. The v-ATPase plays key roles in intracellular and extracellular acidification events in numerous biological contexts; however, its role in the eye has not been well studied. Here, we sought to characterize the ocular defects in zebrafish v-ATPase mutants and to determine if they represent useful models for studying degenerative conditions of the human eye. Zebrafish v-ATPase mutants possess concentrated regions of apoptotic cells in the outer nuclear layer and ciliary marginal zone of the retina, and in the RPE. Photoreceptor outer segment structure is abnormal and large membranous inclusions are present in the RPE suggesting an inability of RPE cells to degrade ingested outer segments. Melanosome formation is also compromised. Preliminary observations suggest that drusen-like deposits may also be accumulating in the eyes of aging heterozygous adults. From these results, we conclude that the v-ATPase complex is required for cell survival in the zebrafish retina and RPE. Within the RPE, the v-ATPase complex likely facilitates the pHdependent degradation of ingested photoreceptor outer segments. Defects in v-ATPase function result in an accumulation of undigested outer segment material, which contributes to the RPE and photoreceptor atrophy observed in these mutants, and possibly to that in human retinal degeneration patients. doi:10.1016/j.ydbio.2007.03.146
Program/Abstract # 91 Effect of Aβ expression on development of learning deficits in APP-transgenic mice Janusz Frackowiak, Buddima Ranasinghe, Giuseppe LaFauci, Wojciech Kaczmarski, Richard Rubenstein, Mazur-Kolecka NYS IBRDD, New York, NY, USA Human APP-transgenic mice are a model to study pathomechanisms of learning deficits associated with deposition of amyloid-β peptide (Aβ), e.g. in Down syndrome. The role of
ABSTRACTS / Developmental Biology 306 (2007) 323–328
Aβ oligomerization and fibrillization seems evident in memory loss, however, the responsible pathomechanisms are not clear. Overexpression of the receptor for advanced glycation endproducts (RAGE) in brain amyloidosis-β suggests its involvement in memory loss. RAGE participates in Ab, binding, oligomerization and initiation of inflammation. We generated transgenic mice with human APP(Swe-Dt-Lon) for a developmental study of learning deficits and RAGE expression. APP, Aβ and RAGE in the brain were tested by WB and ICH, respectively. Learning and memory were tested by the Morris water maze test. The strain Tg9279 used in the study had between 15 and 20 transgene copies per genome. Brain levels of Aβ1–40 and Aβ1–42 were 3 and 2 fmol/100 μg protein, respectively, in 6-week-old heterozygous animals. The onset of fibrillar amyloid-b formation, at the age of 12 weeks, coincided with learning and memory deficits in homozygotes. The onset of amyloidosis-β in heterozygous mice was 12 months, however, the onset of learning and memory deficits preceded amyloid deposition by 3 months. We found that RAGE levels in the brains of control mice were the highest at 3 weeks and remained lower and stable at older age. RAGE levels were increased in brains with medium but not with high levels of APP and Aβ expression. The data suggest involvement of distinct mechanisms in memory decline depending on the levels of Aβ expression. Supported by NYS OMRDD. doi:10.1016/j.ydbio.2007.03.147
Program/Abstract # 92 Variations in the bone marrow and the thymus in BALB/c neonates from mothers infected with Toxoplasma gondii during gestation Maria Asunción C. Cabañas 1, Elba M. Reyes 2, Laura Arcelia C. Montiel 2, Ethel Awilda G. Latorre 1, Luis Antonio Z. Jiménez 1 1 Dept. de Inmunol., ENCB IPN, DF, México 2 Dept. de Morf., ENCB IPN, DF, México Toxoplasma gondii infection during gestation is the cause of congenital malformations in living newborn children, as well as the cause of abortions, ocular and neurological disorders. Although several aspects of toxoplasmosis have been studied, alterations in the lymphopoietic system and its contribution to the disease are still poorly understood. We studied the changes in the haematopoietic system during the neonatal stage in Balb/c mice. The percentage of plasma cells was significantly increased in neonates from mothers infected during the last day of gestation. Nevertheless, the percentages of lymphocytes and monocytes were significantly decreased on the same neonates. Weight of the thymus and the number of thymic cells were dramatically decreased in neonates from infected mothers. Results suggest that infection of the mother during the last day of gestation primarily provokes in the neonates changes in the lymphoid organs. The decrease of lymphocytes in bone marrow could be the reason for the diminution in the weight of the thymus. The increase in plasma cells suggests an activation of
327
the immune response possibly due to the infection with T. gondii. Consequently, the variations in the haematopoietic cellular populations can contribute to the severity of the disease in early periods of the development. doi:10.1016/j.ydbio.2007.03.148
Program/Abstract # 93 Periodontitis a risk factor for pre-term birth and low weight of products: An animal model Inés D. Altamirano 1, Martha R. Ayala 3, Maria Asunción Cabañas 1, Onésimo O. Ortega 3 1 Dept. de Inmunol., ENCB IPN., México, DF, México 2 Lab. Multidisc. de Inv., EMGS UDEFA SEDENA., México, DF, México 3 Dept. de Period., UEO SEDENA., México, DF, México Pre-term birth accompanied by low weight at birth (PLBW) is considered one of the most important causes of neonatal mortality. Several researches have demonstrated that periodontitis could be an independent risk factor for this condition. The nature of this connection is not yet clear. Individuals who suffer from periodontitis possess an evident susceptibility to some component of certain Gram-negative bacteria oral, which are present as normal flora in healthy individuals. We sought to determine whether the presence of maternal periodontal infection could be associated with PLBW in an animal model. Periodontitis was induced in female Balb/c mice through inoculation in the gum of a suspension of the microbial components obtained from subgingival of patients with periodontitis. Once the infection was established, according to signs and symptoms evaluated by a periodontal specialist, two infected female were paired with one healthy male. After confirmation of pregnancy and spontaneous birth, products were weighted. A control group of pregnant females without infection was similarly studied. Mice from infected mothers showed low weight at birth. Significant differences were observed between the experimental and the control group. From this model we can conclude that infection of the gums of female mice with microbial components periodontal obtained from patients with periodontitis predispose to low birth weight products. doi:10.1016/j.ydbio.2007.03.149
Program/Abstract # 94 Molecular etiology of cleft palate formation in Wnt5a mutants Fenglei He, Wei Xiong, Shuping Gu, YiPing Chen Dept. of Oral Biol., The Ohio State Univer. Health Sciences Center, Columbus, OH, USA Cleft palate, a common congenital disorder, arises from a failure in the highly regulated multiple-step process of the secondary palate development. Recent studies have implicated
ABSTRACTS / Developmental Biology 306 (2007) 323–328
et al., 2007, Histology and Histopathology, 22: in press) revealed Ctgf down-regulation in the hypoplastic lungs of mouse embryos that completely lacked skeletal muscle and in turn fetal breathing-like movements (FBMs). Therefore, the current report examines pulmonary development of Ctgf−/− mouse fetuses (kindly provided by Dr. Karen M. Lyons) and the possibility of CTGF involvement in the pathogenesis of lung hypoplasia. The Ctgf−/− lungs are hypoplastic, with reduced cell proliferation and increased apoptosis. PDGF-B, its receptor and IGF-I are markedly attenuated, while the TTF-1 gradient is lost. Type II pneumocyte differentiation is perturbed, with the cells depicting excessive glycogen retention and diminished lamellar body size, though able to synthesize surfactantassociated protein. However, type I pneumocyte differentiation is not affected by Ctgf deletion. Our findings indicate that the absence of Ctgf and/or its protein product, CTGF, may induce pulmonary hypoplasia by disrupting basic lung developmental processes. Supported by NSERC, CIHR, LANS, CFI and DMRF to BK. doi:10.1016/j.ydbio.2007.03.144
Program/Abstract # 89 Dll3-Notch1 signaling: Functional genomic analysis of downstream genes & genetic interactions modeling vertebral defects William Sewell 1, Allanceson Smith 1, Kathleen M. Loomes 2, Stacey A. Stevens 3, Megan L. O'Brien 3, Dorian M. Gonzalez 3, J. Ryan 3, Eric F. Rappaport 3 1 School Life Sciences, Arizona State Univ, Tempe AZ, USA 2 Div Gastroenterology & Nutrition, Children’s Hosp Philadelphia PA, USA 3 Div Human Genetics & Orthopaedic Surgery, Children’s Hosp Philadelphia PA, USA 4 Dept Pediatrics, Univ Penn School Med, Philadelphia PA, USA 5 Victor Chang Cardiac Res Inst, Sydney & Faculties Med Sciences, Univ New South Wales, Kensington, Australia 6 Dept Basic Med Sciences, Univ Arizona College Med, Phoenix AZ, USA Mutations in the Notch1 receptor and Dll3 ligand disrupt somitogenesis and vertebral patterning. Previous studies have shown that genetic interactions among members of the notch pathway cause defects not observed in single gene mutations. To examine Dll3–Notch genetic interactions, we generated compound mouse mutants and screened for skeletal malformations and histological anomalies. While Dll3tm1Rbe or Notch1tm1Con heterozygous mice appeared normal, 30% of double heterozygous animals displayed segmental malformations similar to those in birth defects such as congenital scoliosis. Developmental analysis of somite-stage embryos and perinatal organs did not reveal any defects. To identify potential disruptions earlier in development, we used microarray analysis of Dll3 and Notch1 homozygous 9.5 dpc embryos, and we are investigating
genes such as brachyury and Hoxb8 that display greater than 2fold changes in expression. These findings have identified that Dll3–Notch1 double heterozygous mutants may be a useful model to study the etiology of human congenital scoliosis and vertebral birth defects. doi:10.1016/j.ydbio.2007.03.145
Program/Abstract # 90 The vacuolar-ATPase complex is required for the survival of retinal and RPE cells in the zebrafish eye Jeffrey M. Gross, Richard Nuckels MCDB Dept., Univ. Texas at Austin In a retrovirus-based insertional mutagenesis screen, we identified six recessive zebrafish mutants that presented with pigmentation deficits and severe degeneration of the retina and RPE. Each of the mutations disrupted a distinct subunit of the vacuolar-ATPase complex (v-ATPase), or proteins that associate with the v-ATPase. The v-ATPase plays key roles in intracellular and extracellular acidification events in numerous biological contexts; however, its role in the eye has not been well studied. Here, we sought to characterize the ocular defects in zebrafish v-ATPase mutants and to determine if they represent useful models for studying degenerative conditions of the human eye. Zebrafish v-ATPase mutants possess concentrated regions of apoptotic cells in the outer nuclear layer and ciliary marginal zone of the retina, and in the RPE. Photoreceptor outer segment structure is abnormal and large membranous inclusions are present in the RPE suggesting an inability of RPE cells to degrade ingested outer segments. Melanosome formation is also compromised. Preliminary observations suggest that drusen-like deposits may also be accumulating in the eyes of aging heterozygous adults. From these results, we conclude that the v-ATPase complex is required for cell survival in the zebrafish retina and RPE. Within the RPE, the v-ATPase complex likely facilitates the pHdependent degradation of ingested photoreceptor outer segments. Defects in v-ATPase function result in an accumulation of undigested outer segment material, which contributes to the RPE and photoreceptor atrophy observed in these mutants, and possibly to that in human retinal degeneration patients. doi:10.1016/j.ydbio.2007.03.146
Program/Abstract # 91 Effect of Aβ expression on development of learning deficits in APP-transgenic mice Janusz Frackowiak, Buddima Ranasinghe, Giuseppe LaFauci, Wojciech Kaczmarski, Richard Rubenstein, Mazur-Kolecka NYS IBRDD, New York, NY, USA Human APP-transgenic mice are a model to study pathomechanisms of learning deficits associated with deposition of amyloid-β peptide (Aβ), e.g. in Down syndrome. The role of
ABSTRACTS / Developmental Biology 306 (2007) 323–328
Aβ oligomerization and fibrillization seems evident in memory loss, however, the responsible pathomechanisms are not clear. Overexpression of the receptor for advanced glycation endproducts (RAGE) in brain amyloidosis-β suggests its involvement in memory loss. RAGE participates in Ab, binding, oligomerization and initiation of inflammation. We generated transgenic mice with human APP(Swe-Dt-Lon) for a developmental study of learning deficits and RAGE expression. APP, Aβ and RAGE in the brain were tested by WB and ICH, respectively. Learning and memory were tested by the Morris water maze test. The strain Tg9279 used in the study had between 15 and 20 transgene copies per genome. Brain levels of Aβ1–40 and Aβ1–42 were 3 and 2 fmol/100 μg protein, respectively, in 6-week-old heterozygous animals. The onset of fibrillar amyloid-b formation, at the age of 12 weeks, coincided with learning and memory deficits in homozygotes. The onset of amyloidosis-β in heterozygous mice was 12 months, however, the onset of learning and memory deficits preceded amyloid deposition by 3 months. We found that RAGE levels in the brains of control mice were the highest at 3 weeks and remained lower and stable at older age. RAGE levels were increased in brains with medium but not with high levels of APP and Aβ expression. The data suggest involvement of distinct mechanisms in memory decline depending on the levels of Aβ expression. Supported by NYS OMRDD. doi:10.1016/j.ydbio.2007.03.147
Program/Abstract # 92 Variations in the bone marrow and the thymus in BALB/c neonates from mothers infected with Toxoplasma gondii during gestation Maria Asunción C. Cabañas 1, Elba M. Reyes 2, Laura Arcelia C. Montiel 2, Ethel Awilda G. Latorre 1, Luis Antonio Z. Jiménez 1 1 Dept. de Inmunol., ENCB IPN, DF, México 2 Dept. de Morf., ENCB IPN, DF, México Toxoplasma gondii infection during gestation is the cause of congenital malformations in living newborn children, as well as the cause of abortions, ocular and neurological disorders. Although several aspects of toxoplasmosis have been studied, alterations in the lymphopoietic system and its contribution to the disease are still poorly understood. We studied the changes in the haematopoietic system during the neonatal stage in Balb/c mice. The percentage of plasma cells was significantly increased in neonates from mothers infected during the last day of gestation. Nevertheless, the percentages of lymphocytes and monocytes were significantly decreased on the same neonates. Weight of the thymus and the number of thymic cells were dramatically decreased in neonates from infected mothers. Results suggest that infection of the mother during the last day of gestation primarily provokes in the neonates changes in the lymphoid organs. The decrease of lymphocytes in bone marrow could be the reason for the diminution in the weight of the thymus. The increase in plasma cells suggests an activation of
327
the immune response possibly due to the infection with T. gondii. Consequently, the variations in the haematopoietic cellular populations can contribute to the severity of the disease in early periods of the development. doi:10.1016/j.ydbio.2007.03.148
Program/Abstract # 93 Periodontitis a risk factor for pre-term birth and low weight of products: An animal model Inés D. Altamirano 1, Martha R. Ayala 3, Maria Asunción Cabañas 1, Onésimo O. Ortega 3 1 Dept. de Inmunol., ENCB IPN., México, DF, México 2 Lab. Multidisc. de Inv., EMGS UDEFA SEDENA., México, DF, México 3 Dept. de Period., UEO SEDENA., México, DF, México Pre-term birth accompanied by low weight at birth (PLBW) is considered one of the most important causes of neonatal mortality. Several researches have demonstrated that periodontitis could be an independent risk factor for this condition. The nature of this connection is not yet clear. Individuals who suffer from periodontitis possess an evident susceptibility to some component of certain Gram-negative bacteria oral, which are present as normal flora in healthy individuals. We sought to determine whether the presence of maternal periodontal infection could be associated with PLBW in an animal model. Periodontitis was induced in female Balb/c mice through inoculation in the gum of a suspension of the microbial components obtained from subgingival of patients with periodontitis. Once the infection was established, according to signs and symptoms evaluated by a periodontal specialist, two infected female were paired with one healthy male. After confirmation of pregnancy and spontaneous birth, products were weighted. A control group of pregnant females without infection was similarly studied. Mice from infected mothers showed low weight at birth. Significant differences were observed between the experimental and the control group. From this model we can conclude that infection of the gums of female mice with microbial components periodontal obtained from patients with periodontitis predispose to low birth weight products. doi:10.1016/j.ydbio.2007.03.149
Program/Abstract # 94 Molecular etiology of cleft palate formation in Wnt5a mutants Fenglei He, Wei Xiong, Shuping Gu, YiPing Chen Dept. of Oral Biol., The Ohio State Univer. Health Sciences Center, Columbus, OH, USA Cleft palate, a common congenital disorder, arises from a failure in the highly regulated multiple-step process of the secondary palate development. Recent studies have implicated